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4303 lines
115 KiB
4303 lines
115 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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// SPI init/core code |
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// |
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// Copyright (C) 2005 David Brownell |
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// Copyright (C) 2008 Secret Lab Technologies Ltd. |
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|
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#include <linux/kernel.h> |
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#include <linux/device.h> |
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#include <linux/init.h> |
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#include <linux/cache.h> |
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#include <linux/dma-mapping.h> |
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#include <linux/dmaengine.h> |
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#include <linux/mutex.h> |
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#include <linux/of_device.h> |
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#include <linux/of_irq.h> |
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#include <linux/clk/clk-conf.h> |
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#include <linux/slab.h> |
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#include <linux/mod_devicetable.h> |
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#include <linux/spi/spi.h> |
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#include <linux/spi/spi-mem.h> |
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#include <linux/of_gpio.h> |
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#include <linux/gpio/consumer.h> |
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#include <linux/pm_runtime.h> |
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#include <linux/pm_domain.h> |
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#include <linux/property.h> |
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#include <linux/export.h> |
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#include <linux/sched/rt.h> |
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#include <uapi/linux/sched/types.h> |
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#include <linux/delay.h> |
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#include <linux/kthread.h> |
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#include <linux/ioport.h> |
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#include <linux/acpi.h> |
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#include <linux/highmem.h> |
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#include <linux/idr.h> |
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#include <linux/platform_data/x86/apple.h> |
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|
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#define CREATE_TRACE_POINTS |
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#include <trace/events/spi.h> |
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EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start); |
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EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop); |
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#include "internals.h" |
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static DEFINE_IDR(spi_master_idr); |
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|
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static void spidev_release(struct device *dev) |
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{ |
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struct spi_device *spi = to_spi_device(dev); |
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/* spi controllers may cleanup for released devices */ |
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if (spi->controller->cleanup) |
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spi->controller->cleanup(spi); |
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spi_controller_put(spi->controller); |
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kfree(spi->driver_override); |
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kfree(spi); |
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} |
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static ssize_t |
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modalias_show(struct device *dev, struct device_attribute *a, char *buf) |
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{ |
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const struct spi_device *spi = to_spi_device(dev); |
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int len; |
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len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); |
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if (len != -ENODEV) |
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return len; |
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return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias); |
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} |
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static DEVICE_ATTR_RO(modalias); |
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static ssize_t driver_override_store(struct device *dev, |
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struct device_attribute *a, |
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const char *buf, size_t count) |
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{ |
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struct spi_device *spi = to_spi_device(dev); |
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const char *end = memchr(buf, '\n', count); |
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const size_t len = end ? end - buf : count; |
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const char *driver_override, *old; |
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/* We need to keep extra room for a newline when displaying value */ |
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if (len >= (PAGE_SIZE - 1)) |
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return -EINVAL; |
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driver_override = kstrndup(buf, len, GFP_KERNEL); |
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if (!driver_override) |
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return -ENOMEM; |
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device_lock(dev); |
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old = spi->driver_override; |
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if (len) { |
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spi->driver_override = driver_override; |
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} else { |
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/* Empty string, disable driver override */ |
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spi->driver_override = NULL; |
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kfree(driver_override); |
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} |
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device_unlock(dev); |
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kfree(old); |
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return count; |
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} |
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static ssize_t driver_override_show(struct device *dev, |
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struct device_attribute *a, char *buf) |
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{ |
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const struct spi_device *spi = to_spi_device(dev); |
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ssize_t len; |
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device_lock(dev); |
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len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : ""); |
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device_unlock(dev); |
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return len; |
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} |
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static DEVICE_ATTR_RW(driver_override); |
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#define SPI_STATISTICS_ATTRS(field, file) \ |
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static ssize_t spi_controller_##field##_show(struct device *dev, \ |
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struct device_attribute *attr, \ |
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char *buf) \ |
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{ \ |
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struct spi_controller *ctlr = container_of(dev, \ |
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struct spi_controller, dev); \ |
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return spi_statistics_##field##_show(&ctlr->statistics, buf); \ |
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} \ |
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static struct device_attribute dev_attr_spi_controller_##field = { \ |
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.attr = { .name = file, .mode = 0444 }, \ |
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.show = spi_controller_##field##_show, \ |
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}; \ |
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static ssize_t spi_device_##field##_show(struct device *dev, \ |
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struct device_attribute *attr, \ |
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char *buf) \ |
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{ \ |
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struct spi_device *spi = to_spi_device(dev); \ |
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return spi_statistics_##field##_show(&spi->statistics, buf); \ |
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} \ |
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static struct device_attribute dev_attr_spi_device_##field = { \ |
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.attr = { .name = file, .mode = 0444 }, \ |
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.show = spi_device_##field##_show, \ |
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} |
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#define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \ |
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static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \ |
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char *buf) \ |
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{ \ |
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unsigned long flags; \ |
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ssize_t len; \ |
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spin_lock_irqsave(&stat->lock, flags); \ |
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len = sprintf(buf, format_string, stat->field); \ |
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spin_unlock_irqrestore(&stat->lock, flags); \ |
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return len; \ |
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} \ |
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SPI_STATISTICS_ATTRS(name, file) |
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#define SPI_STATISTICS_SHOW(field, format_string) \ |
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SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \ |
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field, format_string) |
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SPI_STATISTICS_SHOW(messages, "%lu"); |
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SPI_STATISTICS_SHOW(transfers, "%lu"); |
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SPI_STATISTICS_SHOW(errors, "%lu"); |
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SPI_STATISTICS_SHOW(timedout, "%lu"); |
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SPI_STATISTICS_SHOW(spi_sync, "%lu"); |
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SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu"); |
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SPI_STATISTICS_SHOW(spi_async, "%lu"); |
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SPI_STATISTICS_SHOW(bytes, "%llu"); |
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SPI_STATISTICS_SHOW(bytes_rx, "%llu"); |
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SPI_STATISTICS_SHOW(bytes_tx, "%llu"); |
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#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \ |
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SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \ |
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"transfer_bytes_histo_" number, \ |
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transfer_bytes_histo[index], "%lu") |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535"); |
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+"); |
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SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu"); |
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static struct attribute *spi_dev_attrs[] = { |
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&dev_attr_modalias.attr, |
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&dev_attr_driver_override.attr, |
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NULL, |
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}; |
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static const struct attribute_group spi_dev_group = { |
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.attrs = spi_dev_attrs, |
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}; |
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static struct attribute *spi_device_statistics_attrs[] = { |
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&dev_attr_spi_device_messages.attr, |
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&dev_attr_spi_device_transfers.attr, |
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&dev_attr_spi_device_errors.attr, |
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&dev_attr_spi_device_timedout.attr, |
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&dev_attr_spi_device_spi_sync.attr, |
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&dev_attr_spi_device_spi_sync_immediate.attr, |
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&dev_attr_spi_device_spi_async.attr, |
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&dev_attr_spi_device_bytes.attr, |
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&dev_attr_spi_device_bytes_rx.attr, |
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&dev_attr_spi_device_bytes_tx.attr, |
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&dev_attr_spi_device_transfer_bytes_histo0.attr, |
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&dev_attr_spi_device_transfer_bytes_histo1.attr, |
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&dev_attr_spi_device_transfer_bytes_histo2.attr, |
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&dev_attr_spi_device_transfer_bytes_histo3.attr, |
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&dev_attr_spi_device_transfer_bytes_histo4.attr, |
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&dev_attr_spi_device_transfer_bytes_histo5.attr, |
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&dev_attr_spi_device_transfer_bytes_histo6.attr, |
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&dev_attr_spi_device_transfer_bytes_histo7.attr, |
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&dev_attr_spi_device_transfer_bytes_histo8.attr, |
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&dev_attr_spi_device_transfer_bytes_histo9.attr, |
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&dev_attr_spi_device_transfer_bytes_histo10.attr, |
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&dev_attr_spi_device_transfer_bytes_histo11.attr, |
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&dev_attr_spi_device_transfer_bytes_histo12.attr, |
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&dev_attr_spi_device_transfer_bytes_histo13.attr, |
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&dev_attr_spi_device_transfer_bytes_histo14.attr, |
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&dev_attr_spi_device_transfer_bytes_histo15.attr, |
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&dev_attr_spi_device_transfer_bytes_histo16.attr, |
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&dev_attr_spi_device_transfers_split_maxsize.attr, |
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NULL, |
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}; |
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static const struct attribute_group spi_device_statistics_group = { |
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.name = "statistics", |
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.attrs = spi_device_statistics_attrs, |
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}; |
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static const struct attribute_group *spi_dev_groups[] = { |
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&spi_dev_group, |
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&spi_device_statistics_group, |
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NULL, |
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}; |
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static struct attribute *spi_controller_statistics_attrs[] = { |
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&dev_attr_spi_controller_messages.attr, |
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&dev_attr_spi_controller_transfers.attr, |
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&dev_attr_spi_controller_errors.attr, |
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&dev_attr_spi_controller_timedout.attr, |
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&dev_attr_spi_controller_spi_sync.attr, |
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&dev_attr_spi_controller_spi_sync_immediate.attr, |
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&dev_attr_spi_controller_spi_async.attr, |
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&dev_attr_spi_controller_bytes.attr, |
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&dev_attr_spi_controller_bytes_rx.attr, |
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&dev_attr_spi_controller_bytes_tx.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo0.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo1.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo2.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo3.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo4.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo5.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo6.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo7.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo8.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo9.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo10.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo11.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo12.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo13.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo14.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo15.attr, |
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&dev_attr_spi_controller_transfer_bytes_histo16.attr, |
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&dev_attr_spi_controller_transfers_split_maxsize.attr, |
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NULL, |
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}; |
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static const struct attribute_group spi_controller_statistics_group = { |
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.name = "statistics", |
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.attrs = spi_controller_statistics_attrs, |
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}; |
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static const struct attribute_group *spi_master_groups[] = { |
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&spi_controller_statistics_group, |
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NULL, |
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}; |
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void spi_statistics_add_transfer_stats(struct spi_statistics *stats, |
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struct spi_transfer *xfer, |
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struct spi_controller *ctlr) |
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{ |
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unsigned long flags; |
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int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1; |
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if (l2len < 0) |
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l2len = 0; |
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spin_lock_irqsave(&stats->lock, flags); |
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stats->transfers++; |
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stats->transfer_bytes_histo[l2len]++; |
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stats->bytes += xfer->len; |
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if ((xfer->tx_buf) && |
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(xfer->tx_buf != ctlr->dummy_tx)) |
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stats->bytes_tx += xfer->len; |
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if ((xfer->rx_buf) && |
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(xfer->rx_buf != ctlr->dummy_rx)) |
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stats->bytes_rx += xfer->len; |
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spin_unlock_irqrestore(&stats->lock, flags); |
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} |
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EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats); |
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/* modalias support makes "modprobe $MODALIAS" new-style hotplug work, |
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* and the sysfs version makes coldplug work too. |
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*/ |
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static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, |
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const struct spi_device *sdev) |
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{ |
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while (id->name[0]) { |
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if (!strcmp(sdev->modalias, id->name)) |
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return id; |
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id++; |
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} |
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return NULL; |
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} |
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const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev) |
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{ |
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const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver); |
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return spi_match_id(sdrv->id_table, sdev); |
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} |
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EXPORT_SYMBOL_GPL(spi_get_device_id); |
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static int spi_match_device(struct device *dev, struct device_driver *drv) |
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{ |
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const struct spi_device *spi = to_spi_device(dev); |
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const struct spi_driver *sdrv = to_spi_driver(drv); |
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/* Check override first, and if set, only use the named driver */ |
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if (spi->driver_override) |
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return strcmp(spi->driver_override, drv->name) == 0; |
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/* Attempt an OF style match */ |
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if (of_driver_match_device(dev, drv)) |
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return 1; |
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/* Then try ACPI */ |
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if (acpi_driver_match_device(dev, drv)) |
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return 1; |
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if (sdrv->id_table) |
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return !!spi_match_id(sdrv->id_table, spi); |
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return strcmp(spi->modalias, drv->name) == 0; |
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} |
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static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) |
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{ |
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const struct spi_device *spi = to_spi_device(dev); |
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int rc; |
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rc = acpi_device_uevent_modalias(dev, env); |
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if (rc != -ENODEV) |
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return rc; |
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return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); |
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} |
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static int spi_probe(struct device *dev) |
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{ |
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const struct spi_driver *sdrv = to_spi_driver(dev->driver); |
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struct spi_device *spi = to_spi_device(dev); |
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int ret; |
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ret = of_clk_set_defaults(dev->of_node, false); |
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if (ret) |
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return ret; |
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if (dev->of_node) { |
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spi->irq = of_irq_get(dev->of_node, 0); |
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if (spi->irq == -EPROBE_DEFER) |
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return -EPROBE_DEFER; |
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if (spi->irq < 0) |
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spi->irq = 0; |
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} |
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ret = dev_pm_domain_attach(dev, true); |
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if (ret) |
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return ret; |
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if (sdrv->probe) { |
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ret = sdrv->probe(spi); |
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if (ret) |
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dev_pm_domain_detach(dev, true); |
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} |
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return ret; |
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} |
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static int spi_remove(struct device *dev) |
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{ |
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const struct spi_driver *sdrv = to_spi_driver(dev->driver); |
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if (sdrv->remove) { |
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int ret; |
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ret = sdrv->remove(to_spi_device(dev)); |
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if (ret) |
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dev_warn(dev, |
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"Failed to unbind driver (%pe), ignoring\n", |
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ERR_PTR(ret)); |
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} |
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dev_pm_domain_detach(dev, true); |
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return 0; |
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} |
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static void spi_shutdown(struct device *dev) |
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{ |
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if (dev->driver) { |
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const struct spi_driver *sdrv = to_spi_driver(dev->driver); |
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|
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if (sdrv->shutdown) |
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sdrv->shutdown(to_spi_device(dev)); |
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} |
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} |
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struct bus_type spi_bus_type = { |
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.name = "spi", |
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.dev_groups = spi_dev_groups, |
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.match = spi_match_device, |
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.uevent = spi_uevent, |
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.probe = spi_probe, |
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.remove = spi_remove, |
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.shutdown = spi_shutdown, |
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}; |
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EXPORT_SYMBOL_GPL(spi_bus_type); |
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|
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/** |
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* __spi_register_driver - register a SPI driver |
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* @owner: owner module of the driver to register |
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* @sdrv: the driver to register |
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* Context: can sleep |
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* |
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* Return: zero on success, else a negative error code. |
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*/ |
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int __spi_register_driver(struct module *owner, struct spi_driver *sdrv) |
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{ |
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sdrv->driver.owner = owner; |
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sdrv->driver.bus = &spi_bus_type; |
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return driver_register(&sdrv->driver); |
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} |
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EXPORT_SYMBOL_GPL(__spi_register_driver); |
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|
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/*-------------------------------------------------------------------------*/ |
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|
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/* SPI devices should normally not be created by SPI device drivers; that |
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* would make them board-specific. Similarly with SPI controller drivers. |
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* Device registration normally goes into like arch/.../mach.../board-YYY.c |
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* with other readonly (flashable) information about mainboard devices. |
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*/ |
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|
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struct boardinfo { |
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struct list_head list; |
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struct spi_board_info board_info; |
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}; |
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|
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static LIST_HEAD(board_list); |
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static LIST_HEAD(spi_controller_list); |
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|
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/* |
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* Used to protect add/del operation for board_info list and |
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* spi_controller list, and their matching process |
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* also used to protect object of type struct idr |
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*/ |
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static DEFINE_MUTEX(board_lock); |
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|
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/* |
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* Prevents addition of devices with same chip select and |
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* addition of devices below an unregistering controller. |
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*/ |
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static DEFINE_MUTEX(spi_add_lock); |
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|
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/** |
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* spi_alloc_device - Allocate a new SPI device |
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* @ctlr: Controller to which device is connected |
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* Context: can sleep |
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* |
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* Allows a driver to allocate and initialize a spi_device without |
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* registering it immediately. This allows a driver to directly |
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* fill the spi_device with device parameters before calling |
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* spi_add_device() on it. |
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* |
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* Caller is responsible to call spi_add_device() on the returned |
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* spi_device structure to add it to the SPI controller. If the caller |
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* needs to discard the spi_device without adding it, then it should |
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* call spi_dev_put() on it. |
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* |
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* Return: a pointer to the new device, or NULL. |
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*/ |
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struct spi_device *spi_alloc_device(struct spi_controller *ctlr) |
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{ |
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struct spi_device *spi; |
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|
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if (!spi_controller_get(ctlr)) |
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return NULL; |
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|
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spi = kzalloc(sizeof(*spi), GFP_KERNEL); |
|
if (!spi) { |
|
spi_controller_put(ctlr); |
|
return NULL; |
|
} |
|
|
|
spi->master = spi->controller = ctlr; |
|
spi->dev.parent = &ctlr->dev; |
|
spi->dev.bus = &spi_bus_type; |
|
spi->dev.release = spidev_release; |
|
spi->cs_gpio = -ENOENT; |
|
spi->mode = ctlr->buswidth_override_bits; |
|
|
|
spin_lock_init(&spi->statistics.lock); |
|
|
|
device_initialize(&spi->dev); |
|
return spi; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_alloc_device); |
|
|
|
static void spi_dev_set_name(struct spi_device *spi) |
|
{ |
|
struct acpi_device *adev = ACPI_COMPANION(&spi->dev); |
|
|
|
if (adev) { |
|
dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev)); |
|
return; |
|
} |
|
|
|
dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev), |
|
spi->chip_select); |
|
} |
|
|
|
static int spi_dev_check(struct device *dev, void *data) |
|
{ |
|
struct spi_device *spi = to_spi_device(dev); |
|
struct spi_device *new_spi = data; |
|
|
|
if (spi->controller == new_spi->controller && |
|
spi->chip_select == new_spi->chip_select) |
|
return -EBUSY; |
|
return 0; |
|
} |
|
|
|
/** |
|
* spi_add_device - Add spi_device allocated with spi_alloc_device |
|
* @spi: spi_device to register |
|
* |
|
* Companion function to spi_alloc_device. Devices allocated with |
|
* spi_alloc_device can be added onto the spi bus with this function. |
|
* |
|
* Return: 0 on success; negative errno on failure |
|
*/ |
|
int spi_add_device(struct spi_device *spi) |
|
{ |
|
struct spi_controller *ctlr = spi->controller; |
|
struct device *dev = ctlr->dev.parent; |
|
int status; |
|
|
|
/* Chipselects are numbered 0..max; validate. */ |
|
if (spi->chip_select >= ctlr->num_chipselect) { |
|
dev_err(dev, "cs%d >= max %d\n", spi->chip_select, |
|
ctlr->num_chipselect); |
|
return -EINVAL; |
|
} |
|
|
|
/* Set the bus ID string */ |
|
spi_dev_set_name(spi); |
|
|
|
/* We need to make sure there's no other device with this |
|
* chipselect **BEFORE** we call setup(), else we'll trash |
|
* its configuration. Lock against concurrent add() calls. |
|
*/ |
|
mutex_lock(&spi_add_lock); |
|
|
|
status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); |
|
if (status) { |
|
dev_err(dev, "chipselect %d already in use\n", |
|
spi->chip_select); |
|
goto done; |
|
} |
|
|
|
/* Controller may unregister concurrently */ |
|
if (IS_ENABLED(CONFIG_SPI_DYNAMIC) && |
|
!device_is_registered(&ctlr->dev)) { |
|
status = -ENODEV; |
|
goto done; |
|
} |
|
|
|
/* Descriptors take precedence */ |
|
if (ctlr->cs_gpiods) |
|
spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select]; |
|
else if (ctlr->cs_gpios) |
|
spi->cs_gpio = ctlr->cs_gpios[spi->chip_select]; |
|
|
|
/* Drivers may modify this initial i/o setup, but will |
|
* normally rely on the device being setup. Devices |
|
* using SPI_CS_HIGH can't coexist well otherwise... |
|
*/ |
|
status = spi_setup(spi); |
|
if (status < 0) { |
|
dev_err(dev, "can't setup %s, status %d\n", |
|
dev_name(&spi->dev), status); |
|
goto done; |
|
} |
|
|
|
/* Device may be bound to an active driver when this returns */ |
|
status = device_add(&spi->dev); |
|
if (status < 0) |
|
dev_err(dev, "can't add %s, status %d\n", |
|
dev_name(&spi->dev), status); |
|
else |
|
dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); |
|
|
|
done: |
|
mutex_unlock(&spi_add_lock); |
|
return status; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_add_device); |
|
|
|
/** |
|
* spi_new_device - instantiate one new SPI device |
|
* @ctlr: Controller to which device is connected |
|
* @chip: Describes the SPI device |
|
* Context: can sleep |
|
* |
|
* On typical mainboards, this is purely internal; and it's not needed |
|
* after board init creates the hard-wired devices. Some development |
|
* platforms may not be able to use spi_register_board_info though, and |
|
* this is exported so that for example a USB or parport based adapter |
|
* driver could add devices (which it would learn about out-of-band). |
|
* |
|
* Return: the new device, or NULL. |
|
*/ |
|
struct spi_device *spi_new_device(struct spi_controller *ctlr, |
|
struct spi_board_info *chip) |
|
{ |
|
struct spi_device *proxy; |
|
int status; |
|
|
|
/* NOTE: caller did any chip->bus_num checks necessary. |
|
* |
|
* Also, unless we change the return value convention to use |
|
* error-or-pointer (not NULL-or-pointer), troubleshootability |
|
* suggests syslogged diagnostics are best here (ugh). |
|
*/ |
|
|
|
proxy = spi_alloc_device(ctlr); |
|
if (!proxy) |
|
return NULL; |
|
|
|
WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); |
|
|
|
proxy->chip_select = chip->chip_select; |
|
proxy->max_speed_hz = chip->max_speed_hz; |
|
proxy->mode = chip->mode; |
|
proxy->irq = chip->irq; |
|
strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); |
|
proxy->dev.platform_data = (void *) chip->platform_data; |
|
proxy->controller_data = chip->controller_data; |
|
proxy->controller_state = NULL; |
|
|
|
if (chip->properties) { |
|
status = device_add_properties(&proxy->dev, chip->properties); |
|
if (status) { |
|
dev_err(&ctlr->dev, |
|
"failed to add properties to '%s': %d\n", |
|
chip->modalias, status); |
|
goto err_dev_put; |
|
} |
|
} |
|
|
|
status = spi_add_device(proxy); |
|
if (status < 0) |
|
goto err_remove_props; |
|
|
|
return proxy; |
|
|
|
err_remove_props: |
|
if (chip->properties) |
|
device_remove_properties(&proxy->dev); |
|
err_dev_put: |
|
spi_dev_put(proxy); |
|
return NULL; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_new_device); |
|
|
|
/** |
|
* spi_unregister_device - unregister a single SPI device |
|
* @spi: spi_device to unregister |
|
* |
|
* Start making the passed SPI device vanish. Normally this would be handled |
|
* by spi_unregister_controller(). |
|
*/ |
|
void spi_unregister_device(struct spi_device *spi) |
|
{ |
|
if (!spi) |
|
return; |
|
|
|
if (spi->dev.of_node) { |
|
of_node_clear_flag(spi->dev.of_node, OF_POPULATED); |
|
of_node_put(spi->dev.of_node); |
|
} |
|
if (ACPI_COMPANION(&spi->dev)) |
|
acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev)); |
|
device_unregister(&spi->dev); |
|
} |
|
EXPORT_SYMBOL_GPL(spi_unregister_device); |
|
|
|
static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr, |
|
struct spi_board_info *bi) |
|
{ |
|
struct spi_device *dev; |
|
|
|
if (ctlr->bus_num != bi->bus_num) |
|
return; |
|
|
|
dev = spi_new_device(ctlr, bi); |
|
if (!dev) |
|
dev_err(ctlr->dev.parent, "can't create new device for %s\n", |
|
bi->modalias); |
|
} |
|
|
|
/** |
|
* spi_register_board_info - register SPI devices for a given board |
|
* @info: array of chip descriptors |
|
* @n: how many descriptors are provided |
|
* Context: can sleep |
|
* |
|
* Board-specific early init code calls this (probably during arch_initcall) |
|
* with segments of the SPI device table. Any device nodes are created later, |
|
* after the relevant parent SPI controller (bus_num) is defined. We keep |
|
* this table of devices forever, so that reloading a controller driver will |
|
* not make Linux forget about these hard-wired devices. |
|
* |
|
* Other code can also call this, e.g. a particular add-on board might provide |
|
* SPI devices through its expansion connector, so code initializing that board |
|
* would naturally declare its SPI devices. |
|
* |
|
* The board info passed can safely be __initdata ... but be careful of |
|
* any embedded pointers (platform_data, etc), they're copied as-is. |
|
* Device properties are deep-copied though. |
|
* |
|
* Return: zero on success, else a negative error code. |
|
*/ |
|
int spi_register_board_info(struct spi_board_info const *info, unsigned n) |
|
{ |
|
struct boardinfo *bi; |
|
int i; |
|
|
|
if (!n) |
|
return 0; |
|
|
|
bi = kcalloc(n, sizeof(*bi), GFP_KERNEL); |
|
if (!bi) |
|
return -ENOMEM; |
|
|
|
for (i = 0; i < n; i++, bi++, info++) { |
|
struct spi_controller *ctlr; |
|
|
|
memcpy(&bi->board_info, info, sizeof(*info)); |
|
if (info->properties) { |
|
bi->board_info.properties = |
|
property_entries_dup(info->properties); |
|
if (IS_ERR(bi->board_info.properties)) |
|
return PTR_ERR(bi->board_info.properties); |
|
} |
|
|
|
mutex_lock(&board_lock); |
|
list_add_tail(&bi->list, &board_list); |
|
list_for_each_entry(ctlr, &spi_controller_list, list) |
|
spi_match_controller_to_boardinfo(ctlr, |
|
&bi->board_info); |
|
mutex_unlock(&board_lock); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/*-------------------------------------------------------------------------*/ |
|
|
|
static void spi_set_cs(struct spi_device *spi, bool enable, bool force) |
|
{ |
|
bool enable1 = enable; |
|
|
|
/* |
|
* Avoid calling into the driver (or doing delays) if the chip select |
|
* isn't actually changing from the last time this was called. |
|
*/ |
|
if (!force && (spi->controller->last_cs_enable == enable) && |
|
(spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH))) |
|
return; |
|
|
|
spi->controller->last_cs_enable = enable; |
|
spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH; |
|
|
|
if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) || |
|
!spi->controller->set_cs_timing) { |
|
if (enable1) |
|
spi_delay_exec(&spi->controller->cs_setup, NULL); |
|
else |
|
spi_delay_exec(&spi->controller->cs_hold, NULL); |
|
} |
|
|
|
if (spi->mode & SPI_CS_HIGH) |
|
enable = !enable; |
|
|
|
if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) { |
|
if (!(spi->mode & SPI_NO_CS)) { |
|
if (spi->cs_gpiod) { |
|
/* |
|
* Historically ACPI has no means of the GPIO polarity and |
|
* thus the SPISerialBus() resource defines it on the per-chip |
|
* basis. In order to avoid a chain of negations, the GPIO |
|
* polarity is considered being Active High. Even for the cases |
|
* when _DSD() is involved (in the updated versions of ACPI) |
|
* the GPIO CS polarity must be defined Active High to avoid |
|
* ambiguity. That's why we use enable, that takes SPI_CS_HIGH |
|
* into account. |
|
*/ |
|
if (has_acpi_companion(&spi->dev)) |
|
gpiod_set_value_cansleep(spi->cs_gpiod, !enable); |
|
else |
|
/* Polarity handled by GPIO library */ |
|
gpiod_set_value_cansleep(spi->cs_gpiod, enable1); |
|
} else { |
|
/* |
|
* invert the enable line, as active low is |
|
* default for SPI. |
|
*/ |
|
gpio_set_value_cansleep(spi->cs_gpio, !enable); |
|
} |
|
} |
|
/* Some SPI masters need both GPIO CS & slave_select */ |
|
if ((spi->controller->flags & SPI_MASTER_GPIO_SS) && |
|
spi->controller->set_cs) |
|
spi->controller->set_cs(spi, !enable); |
|
} else if (spi->controller->set_cs) { |
|
spi->controller->set_cs(spi, !enable); |
|
} |
|
|
|
if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) || |
|
!spi->controller->set_cs_timing) { |
|
if (!enable1) |
|
spi_delay_exec(&spi->controller->cs_inactive, NULL); |
|
} |
|
} |
|
|
|
#ifdef CONFIG_HAS_DMA |
|
int spi_map_buf(struct spi_controller *ctlr, struct device *dev, |
|
struct sg_table *sgt, void *buf, size_t len, |
|
enum dma_data_direction dir) |
|
{ |
|
const bool vmalloced_buf = is_vmalloc_addr(buf); |
|
unsigned int max_seg_size = dma_get_max_seg_size(dev); |
|
#ifdef CONFIG_HIGHMEM |
|
const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE && |
|
(unsigned long)buf < (PKMAP_BASE + |
|
(LAST_PKMAP * PAGE_SIZE))); |
|
#else |
|
const bool kmap_buf = false; |
|
#endif |
|
int desc_len; |
|
int sgs; |
|
struct page *vm_page; |
|
struct scatterlist *sg; |
|
void *sg_buf; |
|
size_t min; |
|
int i, ret; |
|
|
|
if (vmalloced_buf || kmap_buf) { |
|
desc_len = min_t(int, max_seg_size, PAGE_SIZE); |
|
sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len); |
|
} else if (virt_addr_valid(buf)) { |
|
desc_len = min_t(int, max_seg_size, ctlr->max_dma_len); |
|
sgs = DIV_ROUND_UP(len, desc_len); |
|
} else { |
|
return -EINVAL; |
|
} |
|
|
|
ret = sg_alloc_table(sgt, sgs, GFP_KERNEL); |
|
if (ret != 0) |
|
return ret; |
|
|
|
sg = &sgt->sgl[0]; |
|
for (i = 0; i < sgs; i++) { |
|
|
|
if (vmalloced_buf || kmap_buf) { |
|
/* |
|
* Next scatterlist entry size is the minimum between |
|
* the desc_len and the remaining buffer length that |
|
* fits in a page. |
|
*/ |
|
min = min_t(size_t, desc_len, |
|
min_t(size_t, len, |
|
PAGE_SIZE - offset_in_page(buf))); |
|
if (vmalloced_buf) |
|
vm_page = vmalloc_to_page(buf); |
|
else |
|
vm_page = kmap_to_page(buf); |
|
if (!vm_page) { |
|
sg_free_table(sgt); |
|
return -ENOMEM; |
|
} |
|
sg_set_page(sg, vm_page, |
|
min, offset_in_page(buf)); |
|
} else { |
|
min = min_t(size_t, len, desc_len); |
|
sg_buf = buf; |
|
sg_set_buf(sg, sg_buf, min); |
|
} |
|
|
|
buf += min; |
|
len -= min; |
|
sg = sg_next(sg); |
|
} |
|
|
|
ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir); |
|
if (!ret) |
|
ret = -ENOMEM; |
|
if (ret < 0) { |
|
sg_free_table(sgt); |
|
return ret; |
|
} |
|
|
|
sgt->nents = ret; |
|
|
|
return 0; |
|
} |
|
|
|
void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev, |
|
struct sg_table *sgt, enum dma_data_direction dir) |
|
{ |
|
if (sgt->orig_nents) { |
|
dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir); |
|
sg_free_table(sgt); |
|
} |
|
} |
|
|
|
static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) |
|
{ |
|
struct device *tx_dev, *rx_dev; |
|
struct spi_transfer *xfer; |
|
int ret; |
|
|
|
if (!ctlr->can_dma) |
|
return 0; |
|
|
|
if (ctlr->dma_tx) |
|
tx_dev = ctlr->dma_tx->device->dev; |
|
else |
|
tx_dev = ctlr->dev.parent; |
|
|
|
if (ctlr->dma_rx) |
|
rx_dev = ctlr->dma_rx->device->dev; |
|
else |
|
rx_dev = ctlr->dev.parent; |
|
|
|
list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
|
if (!ctlr->can_dma(ctlr, msg->spi, xfer)) |
|
continue; |
|
|
|
if (xfer->tx_buf != NULL) { |
|
ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg, |
|
(void *)xfer->tx_buf, xfer->len, |
|
DMA_TO_DEVICE); |
|
if (ret != 0) |
|
return ret; |
|
} |
|
|
|
if (xfer->rx_buf != NULL) { |
|
ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg, |
|
xfer->rx_buf, xfer->len, |
|
DMA_FROM_DEVICE); |
|
if (ret != 0) { |
|
spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, |
|
DMA_TO_DEVICE); |
|
return ret; |
|
} |
|
} |
|
} |
|
|
|
ctlr->cur_msg_mapped = true; |
|
|
|
return 0; |
|
} |
|
|
|
static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg) |
|
{ |
|
struct spi_transfer *xfer; |
|
struct device *tx_dev, *rx_dev; |
|
|
|
if (!ctlr->cur_msg_mapped || !ctlr->can_dma) |
|
return 0; |
|
|
|
if (ctlr->dma_tx) |
|
tx_dev = ctlr->dma_tx->device->dev; |
|
else |
|
tx_dev = ctlr->dev.parent; |
|
|
|
if (ctlr->dma_rx) |
|
rx_dev = ctlr->dma_rx->device->dev; |
|
else |
|
rx_dev = ctlr->dev.parent; |
|
|
|
list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
|
if (!ctlr->can_dma(ctlr, msg->spi, xfer)) |
|
continue; |
|
|
|
spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE); |
|
spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); |
|
} |
|
|
|
ctlr->cur_msg_mapped = false; |
|
|
|
return 0; |
|
} |
|
#else /* !CONFIG_HAS_DMA */ |
|
static inline int __spi_map_msg(struct spi_controller *ctlr, |
|
struct spi_message *msg) |
|
{ |
|
return 0; |
|
} |
|
|
|
static inline int __spi_unmap_msg(struct spi_controller *ctlr, |
|
struct spi_message *msg) |
|
{ |
|
return 0; |
|
} |
|
#endif /* !CONFIG_HAS_DMA */ |
|
|
|
static inline int spi_unmap_msg(struct spi_controller *ctlr, |
|
struct spi_message *msg) |
|
{ |
|
struct spi_transfer *xfer; |
|
|
|
list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
|
/* |
|
* Restore the original value of tx_buf or rx_buf if they are |
|
* NULL. |
|
*/ |
|
if (xfer->tx_buf == ctlr->dummy_tx) |
|
xfer->tx_buf = NULL; |
|
if (xfer->rx_buf == ctlr->dummy_rx) |
|
xfer->rx_buf = NULL; |
|
} |
|
|
|
return __spi_unmap_msg(ctlr, msg); |
|
} |
|
|
|
static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) |
|
{ |
|
struct spi_transfer *xfer; |
|
void *tmp; |
|
unsigned int max_tx, max_rx; |
|
|
|
if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX)) |
|
&& !(msg->spi->mode & SPI_3WIRE)) { |
|
max_tx = 0; |
|
max_rx = 0; |
|
|
|
list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
|
if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) && |
|
!xfer->tx_buf) |
|
max_tx = max(xfer->len, max_tx); |
|
if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) && |
|
!xfer->rx_buf) |
|
max_rx = max(xfer->len, max_rx); |
|
} |
|
|
|
if (max_tx) { |
|
tmp = krealloc(ctlr->dummy_tx, max_tx, |
|
GFP_KERNEL | GFP_DMA); |
|
if (!tmp) |
|
return -ENOMEM; |
|
ctlr->dummy_tx = tmp; |
|
memset(tmp, 0, max_tx); |
|
} |
|
|
|
if (max_rx) { |
|
tmp = krealloc(ctlr->dummy_rx, max_rx, |
|
GFP_KERNEL | GFP_DMA); |
|
if (!tmp) |
|
return -ENOMEM; |
|
ctlr->dummy_rx = tmp; |
|
} |
|
|
|
if (max_tx || max_rx) { |
|
list_for_each_entry(xfer, &msg->transfers, |
|
transfer_list) { |
|
if (!xfer->len) |
|
continue; |
|
if (!xfer->tx_buf) |
|
xfer->tx_buf = ctlr->dummy_tx; |
|
if (!xfer->rx_buf) |
|
xfer->rx_buf = ctlr->dummy_rx; |
|
} |
|
} |
|
} |
|
|
|
return __spi_map_msg(ctlr, msg); |
|
} |
|
|
|
static int spi_transfer_wait(struct spi_controller *ctlr, |
|
struct spi_message *msg, |
|
struct spi_transfer *xfer) |
|
{ |
|
struct spi_statistics *statm = &ctlr->statistics; |
|
struct spi_statistics *stats = &msg->spi->statistics; |
|
u32 speed_hz = xfer->speed_hz; |
|
unsigned long long ms; |
|
|
|
if (spi_controller_is_slave(ctlr)) { |
|
if (wait_for_completion_interruptible(&ctlr->xfer_completion)) { |
|
dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n"); |
|
return -EINTR; |
|
} |
|
} else { |
|
if (!speed_hz) |
|
speed_hz = 100000; |
|
|
|
ms = 8LL * 1000LL * xfer->len; |
|
do_div(ms, speed_hz); |
|
ms += ms + 200; /* some tolerance */ |
|
|
|
if (ms > UINT_MAX) |
|
ms = UINT_MAX; |
|
|
|
ms = wait_for_completion_timeout(&ctlr->xfer_completion, |
|
msecs_to_jiffies(ms)); |
|
|
|
if (ms == 0) { |
|
SPI_STATISTICS_INCREMENT_FIELD(statm, timedout); |
|
SPI_STATISTICS_INCREMENT_FIELD(stats, timedout); |
|
dev_err(&msg->spi->dev, |
|
"SPI transfer timed out\n"); |
|
return -ETIMEDOUT; |
|
} |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void _spi_transfer_delay_ns(u32 ns) |
|
{ |
|
if (!ns) |
|
return; |
|
if (ns <= 1000) { |
|
ndelay(ns); |
|
} else { |
|
u32 us = DIV_ROUND_UP(ns, 1000); |
|
|
|
if (us <= 10) |
|
udelay(us); |
|
else |
|
usleep_range(us, us + DIV_ROUND_UP(us, 10)); |
|
} |
|
} |
|
|
|
int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer) |
|
{ |
|
u32 delay = _delay->value; |
|
u32 unit = _delay->unit; |
|
u32 hz; |
|
|
|
if (!delay) |
|
return 0; |
|
|
|
switch (unit) { |
|
case SPI_DELAY_UNIT_USECS: |
|
delay *= 1000; |
|
break; |
|
case SPI_DELAY_UNIT_NSECS: /* nothing to do here */ |
|
break; |
|
case SPI_DELAY_UNIT_SCK: |
|
/* clock cycles need to be obtained from spi_transfer */ |
|
if (!xfer) |
|
return -EINVAL; |
|
/* if there is no effective speed know, then approximate |
|
* by underestimating with half the requested hz |
|
*/ |
|
hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2; |
|
if (!hz) |
|
return -EINVAL; |
|
delay *= DIV_ROUND_UP(1000000000, hz); |
|
break; |
|
default: |
|
return -EINVAL; |
|
} |
|
|
|
return delay; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_delay_to_ns); |
|
|
|
int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer) |
|
{ |
|
int delay; |
|
|
|
might_sleep(); |
|
|
|
if (!_delay) |
|
return -EINVAL; |
|
|
|
delay = spi_delay_to_ns(_delay, xfer); |
|
if (delay < 0) |
|
return delay; |
|
|
|
_spi_transfer_delay_ns(delay); |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_delay_exec); |
|
|
|
static void _spi_transfer_cs_change_delay(struct spi_message *msg, |
|
struct spi_transfer *xfer) |
|
{ |
|
u32 delay = xfer->cs_change_delay.value; |
|
u32 unit = xfer->cs_change_delay.unit; |
|
int ret; |
|
|
|
/* return early on "fast" mode - for everything but USECS */ |
|
if (!delay) { |
|
if (unit == SPI_DELAY_UNIT_USECS) |
|
_spi_transfer_delay_ns(10000); |
|
return; |
|
} |
|
|
|
ret = spi_delay_exec(&xfer->cs_change_delay, xfer); |
|
if (ret) { |
|
dev_err_once(&msg->spi->dev, |
|
"Use of unsupported delay unit %i, using default of 10us\n", |
|
unit); |
|
_spi_transfer_delay_ns(10000); |
|
} |
|
} |
|
|
|
/* |
|
* spi_transfer_one_message - Default implementation of transfer_one_message() |
|
* |
|
* This is a standard implementation of transfer_one_message() for |
|
* drivers which implement a transfer_one() operation. It provides |
|
* standard handling of delays and chip select management. |
|
*/ |
|
static int spi_transfer_one_message(struct spi_controller *ctlr, |
|
struct spi_message *msg) |
|
{ |
|
struct spi_transfer *xfer; |
|
bool keep_cs = false; |
|
int ret = 0; |
|
struct spi_statistics *statm = &ctlr->statistics; |
|
struct spi_statistics *stats = &msg->spi->statistics; |
|
|
|
spi_set_cs(msg->spi, true, false); |
|
|
|
SPI_STATISTICS_INCREMENT_FIELD(statm, messages); |
|
SPI_STATISTICS_INCREMENT_FIELD(stats, messages); |
|
|
|
list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
|
trace_spi_transfer_start(msg, xfer); |
|
|
|
spi_statistics_add_transfer_stats(statm, xfer, ctlr); |
|
spi_statistics_add_transfer_stats(stats, xfer, ctlr); |
|
|
|
if (!ctlr->ptp_sts_supported) { |
|
xfer->ptp_sts_word_pre = 0; |
|
ptp_read_system_prets(xfer->ptp_sts); |
|
} |
|
|
|
if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) { |
|
reinit_completion(&ctlr->xfer_completion); |
|
|
|
fallback_pio: |
|
ret = ctlr->transfer_one(ctlr, msg->spi, xfer); |
|
if (ret < 0) { |
|
if (ctlr->cur_msg_mapped && |
|
(xfer->error & SPI_TRANS_FAIL_NO_START)) { |
|
__spi_unmap_msg(ctlr, msg); |
|
ctlr->fallback = true; |
|
xfer->error &= ~SPI_TRANS_FAIL_NO_START; |
|
goto fallback_pio; |
|
} |
|
|
|
SPI_STATISTICS_INCREMENT_FIELD(statm, |
|
errors); |
|
SPI_STATISTICS_INCREMENT_FIELD(stats, |
|
errors); |
|
dev_err(&msg->spi->dev, |
|
"SPI transfer failed: %d\n", ret); |
|
goto out; |
|
} |
|
|
|
if (ret > 0) { |
|
ret = spi_transfer_wait(ctlr, msg, xfer); |
|
if (ret < 0) |
|
msg->status = ret; |
|
} |
|
} else { |
|
if (xfer->len) |
|
dev_err(&msg->spi->dev, |
|
"Bufferless transfer has length %u\n", |
|
xfer->len); |
|
} |
|
|
|
if (!ctlr->ptp_sts_supported) { |
|
ptp_read_system_postts(xfer->ptp_sts); |
|
xfer->ptp_sts_word_post = xfer->len; |
|
} |
|
|
|
trace_spi_transfer_stop(msg, xfer); |
|
|
|
if (msg->status != -EINPROGRESS) |
|
goto out; |
|
|
|
spi_transfer_delay_exec(xfer); |
|
|
|
if (xfer->cs_change) { |
|
if (list_is_last(&xfer->transfer_list, |
|
&msg->transfers)) { |
|
keep_cs = true; |
|
} else { |
|
spi_set_cs(msg->spi, false, false); |
|
_spi_transfer_cs_change_delay(msg, xfer); |
|
spi_set_cs(msg->spi, true, false); |
|
} |
|
} |
|
|
|
msg->actual_length += xfer->len; |
|
} |
|
|
|
out: |
|
if (ret != 0 || !keep_cs) |
|
spi_set_cs(msg->spi, false, false); |
|
|
|
if (msg->status == -EINPROGRESS) |
|
msg->status = ret; |
|
|
|
if (msg->status && ctlr->handle_err) |
|
ctlr->handle_err(ctlr, msg); |
|
|
|
spi_finalize_current_message(ctlr); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* spi_finalize_current_transfer - report completion of a transfer |
|
* @ctlr: the controller reporting completion |
|
* |
|
* Called by SPI drivers using the core transfer_one_message() |
|
* implementation to notify it that the current interrupt driven |
|
* transfer has finished and the next one may be scheduled. |
|
*/ |
|
void spi_finalize_current_transfer(struct spi_controller *ctlr) |
|
{ |
|
complete(&ctlr->xfer_completion); |
|
} |
|
EXPORT_SYMBOL_GPL(spi_finalize_current_transfer); |
|
|
|
static void spi_idle_runtime_pm(struct spi_controller *ctlr) |
|
{ |
|
if (ctlr->auto_runtime_pm) { |
|
pm_runtime_mark_last_busy(ctlr->dev.parent); |
|
pm_runtime_put_autosuspend(ctlr->dev.parent); |
|
} |
|
} |
|
|
|
/** |
|
* __spi_pump_messages - function which processes spi message queue |
|
* @ctlr: controller to process queue for |
|
* @in_kthread: true if we are in the context of the message pump thread |
|
* |
|
* This function checks if there is any spi message in the queue that |
|
* needs processing and if so call out to the driver to initialize hardware |
|
* and transfer each message. |
|
* |
|
* Note that it is called both from the kthread itself and also from |
|
* inside spi_sync(); the queue extraction handling at the top of the |
|
* function should deal with this safely. |
|
*/ |
|
static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread) |
|
{ |
|
struct spi_transfer *xfer; |
|
struct spi_message *msg; |
|
bool was_busy = false; |
|
unsigned long flags; |
|
int ret; |
|
|
|
/* Lock queue */ |
|
spin_lock_irqsave(&ctlr->queue_lock, flags); |
|
|
|
/* Make sure we are not already running a message */ |
|
if (ctlr->cur_msg) { |
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
return; |
|
} |
|
|
|
/* If another context is idling the device then defer */ |
|
if (ctlr->idling) { |
|
kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); |
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
return; |
|
} |
|
|
|
/* Check if the queue is idle */ |
|
if (list_empty(&ctlr->queue) || !ctlr->running) { |
|
if (!ctlr->busy) { |
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
return; |
|
} |
|
|
|
/* Defer any non-atomic teardown to the thread */ |
|
if (!in_kthread) { |
|
if (!ctlr->dummy_rx && !ctlr->dummy_tx && |
|
!ctlr->unprepare_transfer_hardware) { |
|
spi_idle_runtime_pm(ctlr); |
|
ctlr->busy = false; |
|
trace_spi_controller_idle(ctlr); |
|
} else { |
|
kthread_queue_work(ctlr->kworker, |
|
&ctlr->pump_messages); |
|
} |
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
return; |
|
} |
|
|
|
ctlr->busy = false; |
|
ctlr->idling = true; |
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
|
|
kfree(ctlr->dummy_rx); |
|
ctlr->dummy_rx = NULL; |
|
kfree(ctlr->dummy_tx); |
|
ctlr->dummy_tx = NULL; |
|
if (ctlr->unprepare_transfer_hardware && |
|
ctlr->unprepare_transfer_hardware(ctlr)) |
|
dev_err(&ctlr->dev, |
|
"failed to unprepare transfer hardware\n"); |
|
spi_idle_runtime_pm(ctlr); |
|
trace_spi_controller_idle(ctlr); |
|
|
|
spin_lock_irqsave(&ctlr->queue_lock, flags); |
|
ctlr->idling = false; |
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
return; |
|
} |
|
|
|
/* Extract head of queue */ |
|
msg = list_first_entry(&ctlr->queue, struct spi_message, queue); |
|
ctlr->cur_msg = msg; |
|
|
|
list_del_init(&msg->queue); |
|
if (ctlr->busy) |
|
was_busy = true; |
|
else |
|
ctlr->busy = true; |
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
|
|
mutex_lock(&ctlr->io_mutex); |
|
|
|
if (!was_busy && ctlr->auto_runtime_pm) { |
|
ret = pm_runtime_get_sync(ctlr->dev.parent); |
|
if (ret < 0) { |
|
pm_runtime_put_noidle(ctlr->dev.parent); |
|
dev_err(&ctlr->dev, "Failed to power device: %d\n", |
|
ret); |
|
mutex_unlock(&ctlr->io_mutex); |
|
return; |
|
} |
|
} |
|
|
|
if (!was_busy) |
|
trace_spi_controller_busy(ctlr); |
|
|
|
if (!was_busy && ctlr->prepare_transfer_hardware) { |
|
ret = ctlr->prepare_transfer_hardware(ctlr); |
|
if (ret) { |
|
dev_err(&ctlr->dev, |
|
"failed to prepare transfer hardware: %d\n", |
|
ret); |
|
|
|
if (ctlr->auto_runtime_pm) |
|
pm_runtime_put(ctlr->dev.parent); |
|
|
|
msg->status = ret; |
|
spi_finalize_current_message(ctlr); |
|
|
|
mutex_unlock(&ctlr->io_mutex); |
|
return; |
|
} |
|
} |
|
|
|
trace_spi_message_start(msg); |
|
|
|
if (ctlr->prepare_message) { |
|
ret = ctlr->prepare_message(ctlr, msg); |
|
if (ret) { |
|
dev_err(&ctlr->dev, "failed to prepare message: %d\n", |
|
ret); |
|
msg->status = ret; |
|
spi_finalize_current_message(ctlr); |
|
goto out; |
|
} |
|
ctlr->cur_msg_prepared = true; |
|
} |
|
|
|
ret = spi_map_msg(ctlr, msg); |
|
if (ret) { |
|
msg->status = ret; |
|
spi_finalize_current_message(ctlr); |
|
goto out; |
|
} |
|
|
|
if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) { |
|
list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
|
xfer->ptp_sts_word_pre = 0; |
|
ptp_read_system_prets(xfer->ptp_sts); |
|
} |
|
} |
|
|
|
ret = ctlr->transfer_one_message(ctlr, msg); |
|
if (ret) { |
|
dev_err(&ctlr->dev, |
|
"failed to transfer one message from queue\n"); |
|
goto out; |
|
} |
|
|
|
out: |
|
mutex_unlock(&ctlr->io_mutex); |
|
|
|
/* Prod the scheduler in case transfer_one() was busy waiting */ |
|
if (!ret) |
|
cond_resched(); |
|
} |
|
|
|
/** |
|
* spi_pump_messages - kthread work function which processes spi message queue |
|
* @work: pointer to kthread work struct contained in the controller struct |
|
*/ |
|
static void spi_pump_messages(struct kthread_work *work) |
|
{ |
|
struct spi_controller *ctlr = |
|
container_of(work, struct spi_controller, pump_messages); |
|
|
|
__spi_pump_messages(ctlr, true); |
|
} |
|
|
|
/** |
|
* spi_take_timestamp_pre - helper for drivers to collect the beginning of the |
|
* TX timestamp for the requested byte from the SPI |
|
* transfer. The frequency with which this function |
|
* must be called (once per word, once for the whole |
|
* transfer, once per batch of words etc) is arbitrary |
|
* as long as the @tx buffer offset is greater than or |
|
* equal to the requested byte at the time of the |
|
* call. The timestamp is only taken once, at the |
|
* first such call. It is assumed that the driver |
|
* advances its @tx buffer pointer monotonically. |
|
* @ctlr: Pointer to the spi_controller structure of the driver |
|
* @xfer: Pointer to the transfer being timestamped |
|
* @progress: How many words (not bytes) have been transferred so far |
|
* @irqs_off: If true, will disable IRQs and preemption for the duration of the |
|
* transfer, for less jitter in time measurement. Only compatible |
|
* with PIO drivers. If true, must follow up with |
|
* spi_take_timestamp_post or otherwise system will crash. |
|
* WARNING: for fully predictable results, the CPU frequency must |
|
* also be under control (governor). |
|
*/ |
|
void spi_take_timestamp_pre(struct spi_controller *ctlr, |
|
struct spi_transfer *xfer, |
|
size_t progress, bool irqs_off) |
|
{ |
|
if (!xfer->ptp_sts) |
|
return; |
|
|
|
if (xfer->timestamped) |
|
return; |
|
|
|
if (progress > xfer->ptp_sts_word_pre) |
|
return; |
|
|
|
/* Capture the resolution of the timestamp */ |
|
xfer->ptp_sts_word_pre = progress; |
|
|
|
if (irqs_off) { |
|
local_irq_save(ctlr->irq_flags); |
|
preempt_disable(); |
|
} |
|
|
|
ptp_read_system_prets(xfer->ptp_sts); |
|
} |
|
EXPORT_SYMBOL_GPL(spi_take_timestamp_pre); |
|
|
|
/** |
|
* spi_take_timestamp_post - helper for drivers to collect the end of the |
|
* TX timestamp for the requested byte from the SPI |
|
* transfer. Can be called with an arbitrary |
|
* frequency: only the first call where @tx exceeds |
|
* or is equal to the requested word will be |
|
* timestamped. |
|
* @ctlr: Pointer to the spi_controller structure of the driver |
|
* @xfer: Pointer to the transfer being timestamped |
|
* @progress: How many words (not bytes) have been transferred so far |
|
* @irqs_off: If true, will re-enable IRQs and preemption for the local CPU. |
|
*/ |
|
void spi_take_timestamp_post(struct spi_controller *ctlr, |
|
struct spi_transfer *xfer, |
|
size_t progress, bool irqs_off) |
|
{ |
|
if (!xfer->ptp_sts) |
|
return; |
|
|
|
if (xfer->timestamped) |
|
return; |
|
|
|
if (progress < xfer->ptp_sts_word_post) |
|
return; |
|
|
|
ptp_read_system_postts(xfer->ptp_sts); |
|
|
|
if (irqs_off) { |
|
local_irq_restore(ctlr->irq_flags); |
|
preempt_enable(); |
|
} |
|
|
|
/* Capture the resolution of the timestamp */ |
|
xfer->ptp_sts_word_post = progress; |
|
|
|
xfer->timestamped = true; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_take_timestamp_post); |
|
|
|
/** |
|
* spi_set_thread_rt - set the controller to pump at realtime priority |
|
* @ctlr: controller to boost priority of |
|
* |
|
* This can be called because the controller requested realtime priority |
|
* (by setting the ->rt value before calling spi_register_controller()) or |
|
* because a device on the bus said that its transfers needed realtime |
|
* priority. |
|
* |
|
* NOTE: at the moment if any device on a bus says it needs realtime then |
|
* the thread will be at realtime priority for all transfers on that |
|
* controller. If this eventually becomes a problem we may see if we can |
|
* find a way to boost the priority only temporarily during relevant |
|
* transfers. |
|
*/ |
|
static void spi_set_thread_rt(struct spi_controller *ctlr) |
|
{ |
|
dev_info(&ctlr->dev, |
|
"will run message pump with realtime priority\n"); |
|
sched_set_fifo(ctlr->kworker->task); |
|
} |
|
|
|
static int spi_init_queue(struct spi_controller *ctlr) |
|
{ |
|
ctlr->running = false; |
|
ctlr->busy = false; |
|
|
|
ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev)); |
|
if (IS_ERR(ctlr->kworker)) { |
|
dev_err(&ctlr->dev, "failed to create message pump kworker\n"); |
|
return PTR_ERR(ctlr->kworker); |
|
} |
|
|
|
kthread_init_work(&ctlr->pump_messages, spi_pump_messages); |
|
|
|
/* |
|
* Controller config will indicate if this controller should run the |
|
* message pump with high (realtime) priority to reduce the transfer |
|
* latency on the bus by minimising the delay between a transfer |
|
* request and the scheduling of the message pump thread. Without this |
|
* setting the message pump thread will remain at default priority. |
|
*/ |
|
if (ctlr->rt) |
|
spi_set_thread_rt(ctlr); |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* spi_get_next_queued_message() - called by driver to check for queued |
|
* messages |
|
* @ctlr: the controller to check for queued messages |
|
* |
|
* If there are more messages in the queue, the next message is returned from |
|
* this call. |
|
* |
|
* Return: the next message in the queue, else NULL if the queue is empty. |
|
*/ |
|
struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr) |
|
{ |
|
struct spi_message *next; |
|
unsigned long flags; |
|
|
|
/* get a pointer to the next message, if any */ |
|
spin_lock_irqsave(&ctlr->queue_lock, flags); |
|
next = list_first_entry_or_null(&ctlr->queue, struct spi_message, |
|
queue); |
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
|
|
return next; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_get_next_queued_message); |
|
|
|
/** |
|
* spi_finalize_current_message() - the current message is complete |
|
* @ctlr: the controller to return the message to |
|
* |
|
* Called by the driver to notify the core that the message in the front of the |
|
* queue is complete and can be removed from the queue. |
|
*/ |
|
void spi_finalize_current_message(struct spi_controller *ctlr) |
|
{ |
|
struct spi_transfer *xfer; |
|
struct spi_message *mesg; |
|
unsigned long flags; |
|
int ret; |
|
|
|
spin_lock_irqsave(&ctlr->queue_lock, flags); |
|
mesg = ctlr->cur_msg; |
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
|
|
if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) { |
|
list_for_each_entry(xfer, &mesg->transfers, transfer_list) { |
|
ptp_read_system_postts(xfer->ptp_sts); |
|
xfer->ptp_sts_word_post = xfer->len; |
|
} |
|
} |
|
|
|
if (unlikely(ctlr->ptp_sts_supported)) |
|
list_for_each_entry(xfer, &mesg->transfers, transfer_list) |
|
WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped); |
|
|
|
spi_unmap_msg(ctlr, mesg); |
|
|
|
/* In the prepare_messages callback the spi bus has the opportunity to |
|
* split a transfer to smaller chunks. |
|
* Release splited transfers here since spi_map_msg is done on the |
|
* splited transfers. |
|
*/ |
|
spi_res_release(ctlr, mesg); |
|
|
|
if (ctlr->cur_msg_prepared && ctlr->unprepare_message) { |
|
ret = ctlr->unprepare_message(ctlr, mesg); |
|
if (ret) { |
|
dev_err(&ctlr->dev, "failed to unprepare message: %d\n", |
|
ret); |
|
} |
|
} |
|
|
|
spin_lock_irqsave(&ctlr->queue_lock, flags); |
|
ctlr->cur_msg = NULL; |
|
ctlr->cur_msg_prepared = false; |
|
ctlr->fallback = false; |
|
kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); |
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
|
|
trace_spi_message_done(mesg); |
|
|
|
mesg->state = NULL; |
|
if (mesg->complete) |
|
mesg->complete(mesg->context); |
|
} |
|
EXPORT_SYMBOL_GPL(spi_finalize_current_message); |
|
|
|
static int spi_start_queue(struct spi_controller *ctlr) |
|
{ |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&ctlr->queue_lock, flags); |
|
|
|
if (ctlr->running || ctlr->busy) { |
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
return -EBUSY; |
|
} |
|
|
|
ctlr->running = true; |
|
ctlr->cur_msg = NULL; |
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
|
|
kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); |
|
|
|
return 0; |
|
} |
|
|
|
static int spi_stop_queue(struct spi_controller *ctlr) |
|
{ |
|
unsigned long flags; |
|
unsigned limit = 500; |
|
int ret = 0; |
|
|
|
spin_lock_irqsave(&ctlr->queue_lock, flags); |
|
|
|
/* |
|
* This is a bit lame, but is optimized for the common execution path. |
|
* A wait_queue on the ctlr->busy could be used, but then the common |
|
* execution path (pump_messages) would be required to call wake_up or |
|
* friends on every SPI message. Do this instead. |
|
*/ |
|
while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) { |
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
usleep_range(10000, 11000); |
|
spin_lock_irqsave(&ctlr->queue_lock, flags); |
|
} |
|
|
|
if (!list_empty(&ctlr->queue) || ctlr->busy) |
|
ret = -EBUSY; |
|
else |
|
ctlr->running = false; |
|
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
|
|
if (ret) { |
|
dev_warn(&ctlr->dev, "could not stop message queue\n"); |
|
return ret; |
|
} |
|
return ret; |
|
} |
|
|
|
static int spi_destroy_queue(struct spi_controller *ctlr) |
|
{ |
|
int ret; |
|
|
|
ret = spi_stop_queue(ctlr); |
|
|
|
/* |
|
* kthread_flush_worker will block until all work is done. |
|
* If the reason that stop_queue timed out is that the work will never |
|
* finish, then it does no good to call flush/stop thread, so |
|
* return anyway. |
|
*/ |
|
if (ret) { |
|
dev_err(&ctlr->dev, "problem destroying queue\n"); |
|
return ret; |
|
} |
|
|
|
kthread_destroy_worker(ctlr->kworker); |
|
|
|
return 0; |
|
} |
|
|
|
static int __spi_queued_transfer(struct spi_device *spi, |
|
struct spi_message *msg, |
|
bool need_pump) |
|
{ |
|
struct spi_controller *ctlr = spi->controller; |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&ctlr->queue_lock, flags); |
|
|
|
if (!ctlr->running) { |
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
return -ESHUTDOWN; |
|
} |
|
msg->actual_length = 0; |
|
msg->status = -EINPROGRESS; |
|
|
|
list_add_tail(&msg->queue, &ctlr->queue); |
|
if (!ctlr->busy && need_pump) |
|
kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); |
|
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
|
return 0; |
|
} |
|
|
|
/** |
|
* spi_queued_transfer - transfer function for queued transfers |
|
* @spi: spi device which is requesting transfer |
|
* @msg: spi message which is to handled is queued to driver queue |
|
* |
|
* Return: zero on success, else a negative error code. |
|
*/ |
|
static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg) |
|
{ |
|
return __spi_queued_transfer(spi, msg, true); |
|
} |
|
|
|
static int spi_controller_initialize_queue(struct spi_controller *ctlr) |
|
{ |
|
int ret; |
|
|
|
ctlr->transfer = spi_queued_transfer; |
|
if (!ctlr->transfer_one_message) |
|
ctlr->transfer_one_message = spi_transfer_one_message; |
|
|
|
/* Initialize and start queue */ |
|
ret = spi_init_queue(ctlr); |
|
if (ret) { |
|
dev_err(&ctlr->dev, "problem initializing queue\n"); |
|
goto err_init_queue; |
|
} |
|
ctlr->queued = true; |
|
ret = spi_start_queue(ctlr); |
|
if (ret) { |
|
dev_err(&ctlr->dev, "problem starting queue\n"); |
|
goto err_start_queue; |
|
} |
|
|
|
return 0; |
|
|
|
err_start_queue: |
|
spi_destroy_queue(ctlr); |
|
err_init_queue: |
|
return ret; |
|
} |
|
|
|
/** |
|
* spi_flush_queue - Send all pending messages in the queue from the callers' |
|
* context |
|
* @ctlr: controller to process queue for |
|
* |
|
* This should be used when one wants to ensure all pending messages have been |
|
* sent before doing something. Is used by the spi-mem code to make sure SPI |
|
* memory operations do not preempt regular SPI transfers that have been queued |
|
* before the spi-mem operation. |
|
*/ |
|
void spi_flush_queue(struct spi_controller *ctlr) |
|
{ |
|
if (ctlr->transfer == spi_queued_transfer) |
|
__spi_pump_messages(ctlr, false); |
|
} |
|
|
|
/*-------------------------------------------------------------------------*/ |
|
|
|
#if defined(CONFIG_OF) |
|
static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi, |
|
struct device_node *nc) |
|
{ |
|
u32 value; |
|
int rc; |
|
|
|
/* Mode (clock phase/polarity/etc.) */ |
|
if (of_property_read_bool(nc, "spi-cpha")) |
|
spi->mode |= SPI_CPHA; |
|
if (of_property_read_bool(nc, "spi-cpol")) |
|
spi->mode |= SPI_CPOL; |
|
if (of_property_read_bool(nc, "spi-3wire")) |
|
spi->mode |= SPI_3WIRE; |
|
if (of_property_read_bool(nc, "spi-lsb-first")) |
|
spi->mode |= SPI_LSB_FIRST; |
|
if (of_property_read_bool(nc, "spi-cs-high")) |
|
spi->mode |= SPI_CS_HIGH; |
|
|
|
/* Device DUAL/QUAD mode */ |
|
if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { |
|
switch (value) { |
|
case 0: |
|
spi->mode |= SPI_NO_TX; |
|
break; |
|
case 1: |
|
break; |
|
case 2: |
|
spi->mode |= SPI_TX_DUAL; |
|
break; |
|
case 4: |
|
spi->mode |= SPI_TX_QUAD; |
|
break; |
|
case 8: |
|
spi->mode |= SPI_TX_OCTAL; |
|
break; |
|
default: |
|
dev_warn(&ctlr->dev, |
|
"spi-tx-bus-width %d not supported\n", |
|
value); |
|
break; |
|
} |
|
} |
|
|
|
if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) { |
|
switch (value) { |
|
case 0: |
|
spi->mode |= SPI_NO_RX; |
|
break; |
|
case 1: |
|
break; |
|
case 2: |
|
spi->mode |= SPI_RX_DUAL; |
|
break; |
|
case 4: |
|
spi->mode |= SPI_RX_QUAD; |
|
break; |
|
case 8: |
|
spi->mode |= SPI_RX_OCTAL; |
|
break; |
|
default: |
|
dev_warn(&ctlr->dev, |
|
"spi-rx-bus-width %d not supported\n", |
|
value); |
|
break; |
|
} |
|
} |
|
|
|
if (spi_controller_is_slave(ctlr)) { |
|
if (!of_node_name_eq(nc, "slave")) { |
|
dev_err(&ctlr->dev, "%pOF is not called 'slave'\n", |
|
nc); |
|
return -EINVAL; |
|
} |
|
return 0; |
|
} |
|
|
|
/* Device address */ |
|
rc = of_property_read_u32(nc, "reg", &value); |
|
if (rc) { |
|
dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n", |
|
nc, rc); |
|
return rc; |
|
} |
|
spi->chip_select = value; |
|
|
|
/* Device speed */ |
|
if (!of_property_read_u32(nc, "spi-max-frequency", &value)) |
|
spi->max_speed_hz = value; |
|
|
|
return 0; |
|
} |
|
|
|
static struct spi_device * |
|
of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc) |
|
{ |
|
struct spi_device *spi; |
|
int rc; |
|
|
|
/* Alloc an spi_device */ |
|
spi = spi_alloc_device(ctlr); |
|
if (!spi) { |
|
dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc); |
|
rc = -ENOMEM; |
|
goto err_out; |
|
} |
|
|
|
/* Select device driver */ |
|
rc = of_modalias_node(nc, spi->modalias, |
|
sizeof(spi->modalias)); |
|
if (rc < 0) { |
|
dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc); |
|
goto err_out; |
|
} |
|
|
|
rc = of_spi_parse_dt(ctlr, spi, nc); |
|
if (rc) |
|
goto err_out; |
|
|
|
/* Store a pointer to the node in the device structure */ |
|
of_node_get(nc); |
|
spi->dev.of_node = nc; |
|
|
|
/* Register the new device */ |
|
rc = spi_add_device(spi); |
|
if (rc) { |
|
dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc); |
|
goto err_of_node_put; |
|
} |
|
|
|
return spi; |
|
|
|
err_of_node_put: |
|
of_node_put(nc); |
|
err_out: |
|
spi_dev_put(spi); |
|
return ERR_PTR(rc); |
|
} |
|
|
|
/** |
|
* of_register_spi_devices() - Register child devices onto the SPI bus |
|
* @ctlr: Pointer to spi_controller device |
|
* |
|
* Registers an spi_device for each child node of controller node which |
|
* represents a valid SPI slave. |
|
*/ |
|
static void of_register_spi_devices(struct spi_controller *ctlr) |
|
{ |
|
struct spi_device *spi; |
|
struct device_node *nc; |
|
|
|
if (!ctlr->dev.of_node) |
|
return; |
|
|
|
for_each_available_child_of_node(ctlr->dev.of_node, nc) { |
|
if (of_node_test_and_set_flag(nc, OF_POPULATED)) |
|
continue; |
|
spi = of_register_spi_device(ctlr, nc); |
|
if (IS_ERR(spi)) { |
|
dev_warn(&ctlr->dev, |
|
"Failed to create SPI device for %pOF\n", nc); |
|
of_node_clear_flag(nc, OF_POPULATED); |
|
} |
|
} |
|
} |
|
#else |
|
static void of_register_spi_devices(struct spi_controller *ctlr) { } |
|
#endif |
|
|
|
#ifdef CONFIG_ACPI |
|
struct acpi_spi_lookup { |
|
struct spi_controller *ctlr; |
|
u32 max_speed_hz; |
|
u32 mode; |
|
int irq; |
|
u8 bits_per_word; |
|
u8 chip_select; |
|
}; |
|
|
|
static void acpi_spi_parse_apple_properties(struct acpi_device *dev, |
|
struct acpi_spi_lookup *lookup) |
|
{ |
|
const union acpi_object *obj; |
|
|
|
if (!x86_apple_machine) |
|
return; |
|
|
|
if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj) |
|
&& obj->buffer.length >= 4) |
|
lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer; |
|
|
|
if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj) |
|
&& obj->buffer.length == 8) |
|
lookup->bits_per_word = *(u64 *)obj->buffer.pointer; |
|
|
|
if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj) |
|
&& obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer) |
|
lookup->mode |= SPI_LSB_FIRST; |
|
|
|
if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj) |
|
&& obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) |
|
lookup->mode |= SPI_CPOL; |
|
|
|
if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj) |
|
&& obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) |
|
lookup->mode |= SPI_CPHA; |
|
} |
|
|
|
static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) |
|
{ |
|
struct acpi_spi_lookup *lookup = data; |
|
struct spi_controller *ctlr = lookup->ctlr; |
|
|
|
if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { |
|
struct acpi_resource_spi_serialbus *sb; |
|
acpi_handle parent_handle; |
|
acpi_status status; |
|
|
|
sb = &ares->data.spi_serial_bus; |
|
if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { |
|
|
|
status = acpi_get_handle(NULL, |
|
sb->resource_source.string_ptr, |
|
&parent_handle); |
|
|
|
if (ACPI_FAILURE(status) || |
|
ACPI_HANDLE(ctlr->dev.parent) != parent_handle) |
|
return -ENODEV; |
|
|
|
/* |
|
* ACPI DeviceSelection numbering is handled by the |
|
* host controller driver in Windows and can vary |
|
* from driver to driver. In Linux we always expect |
|
* 0 .. max - 1 so we need to ask the driver to |
|
* translate between the two schemes. |
|
*/ |
|
if (ctlr->fw_translate_cs) { |
|
int cs = ctlr->fw_translate_cs(ctlr, |
|
sb->device_selection); |
|
if (cs < 0) |
|
return cs; |
|
lookup->chip_select = cs; |
|
} else { |
|
lookup->chip_select = sb->device_selection; |
|
} |
|
|
|
lookup->max_speed_hz = sb->connection_speed; |
|
lookup->bits_per_word = sb->data_bit_length; |
|
|
|
if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) |
|
lookup->mode |= SPI_CPHA; |
|
if (sb->clock_polarity == ACPI_SPI_START_HIGH) |
|
lookup->mode |= SPI_CPOL; |
|
if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) |
|
lookup->mode |= SPI_CS_HIGH; |
|
} |
|
} else if (lookup->irq < 0) { |
|
struct resource r; |
|
|
|
if (acpi_dev_resource_interrupt(ares, 0, &r)) |
|
lookup->irq = r.start; |
|
} |
|
|
|
/* Always tell the ACPI core to skip this resource */ |
|
return 1; |
|
} |
|
|
|
static acpi_status acpi_register_spi_device(struct spi_controller *ctlr, |
|
struct acpi_device *adev) |
|
{ |
|
acpi_handle parent_handle = NULL; |
|
struct list_head resource_list; |
|
struct acpi_spi_lookup lookup = {}; |
|
struct spi_device *spi; |
|
int ret; |
|
|
|
if (acpi_bus_get_status(adev) || !adev->status.present || |
|
acpi_device_enumerated(adev)) |
|
return AE_OK; |
|
|
|
lookup.ctlr = ctlr; |
|
lookup.irq = -1; |
|
|
|
INIT_LIST_HEAD(&resource_list); |
|
ret = acpi_dev_get_resources(adev, &resource_list, |
|
acpi_spi_add_resource, &lookup); |
|
acpi_dev_free_resource_list(&resource_list); |
|
|
|
if (ret < 0) |
|
/* found SPI in _CRS but it points to another controller */ |
|
return AE_OK; |
|
|
|
if (!lookup.max_speed_hz && |
|
ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) && |
|
ACPI_HANDLE(ctlr->dev.parent) == parent_handle) { |
|
/* Apple does not use _CRS but nested devices for SPI slaves */ |
|
acpi_spi_parse_apple_properties(adev, &lookup); |
|
} |
|
|
|
if (!lookup.max_speed_hz) |
|
return AE_OK; |
|
|
|
spi = spi_alloc_device(ctlr); |
|
if (!spi) { |
|
dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n", |
|
dev_name(&adev->dev)); |
|
return AE_NO_MEMORY; |
|
} |
|
|
|
|
|
ACPI_COMPANION_SET(&spi->dev, adev); |
|
spi->max_speed_hz = lookup.max_speed_hz; |
|
spi->mode |= lookup.mode; |
|
spi->irq = lookup.irq; |
|
spi->bits_per_word = lookup.bits_per_word; |
|
spi->chip_select = lookup.chip_select; |
|
|
|
acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias, |
|
sizeof(spi->modalias)); |
|
|
|
if (spi->irq < 0) |
|
spi->irq = acpi_dev_gpio_irq_get(adev, 0); |
|
|
|
acpi_device_set_enumerated(adev); |
|
|
|
adev->power.flags.ignore_parent = true; |
|
if (spi_add_device(spi)) { |
|
adev->power.flags.ignore_parent = false; |
|
dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n", |
|
dev_name(&adev->dev)); |
|
spi_dev_put(spi); |
|
} |
|
|
|
return AE_OK; |
|
} |
|
|
|
static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, |
|
void *data, void **return_value) |
|
{ |
|
struct spi_controller *ctlr = data; |
|
struct acpi_device *adev; |
|
|
|
if (acpi_bus_get_device(handle, &adev)) |
|
return AE_OK; |
|
|
|
return acpi_register_spi_device(ctlr, adev); |
|
} |
|
|
|
#define SPI_ACPI_ENUMERATE_MAX_DEPTH 32 |
|
|
|
static void acpi_register_spi_devices(struct spi_controller *ctlr) |
|
{ |
|
acpi_status status; |
|
acpi_handle handle; |
|
|
|
handle = ACPI_HANDLE(ctlr->dev.parent); |
|
if (!handle) |
|
return; |
|
|
|
status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, |
|
SPI_ACPI_ENUMERATE_MAX_DEPTH, |
|
acpi_spi_add_device, NULL, ctlr, NULL); |
|
if (ACPI_FAILURE(status)) |
|
dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n"); |
|
} |
|
#else |
|
static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {} |
|
#endif /* CONFIG_ACPI */ |
|
|
|
static void spi_controller_release(struct device *dev) |
|
{ |
|
struct spi_controller *ctlr; |
|
|
|
ctlr = container_of(dev, struct spi_controller, dev); |
|
kfree(ctlr); |
|
} |
|
|
|
static struct class spi_master_class = { |
|
.name = "spi_master", |
|
.owner = THIS_MODULE, |
|
.dev_release = spi_controller_release, |
|
.dev_groups = spi_master_groups, |
|
}; |
|
|
|
#ifdef CONFIG_SPI_SLAVE |
|
/** |
|
* spi_slave_abort - abort the ongoing transfer request on an SPI slave |
|
* controller |
|
* @spi: device used for the current transfer |
|
*/ |
|
int spi_slave_abort(struct spi_device *spi) |
|
{ |
|
struct spi_controller *ctlr = spi->controller; |
|
|
|
if (spi_controller_is_slave(ctlr) && ctlr->slave_abort) |
|
return ctlr->slave_abort(ctlr); |
|
|
|
return -ENOTSUPP; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_slave_abort); |
|
|
|
static int match_true(struct device *dev, void *data) |
|
{ |
|
return 1; |
|
} |
|
|
|
static ssize_t slave_show(struct device *dev, struct device_attribute *attr, |
|
char *buf) |
|
{ |
|
struct spi_controller *ctlr = container_of(dev, struct spi_controller, |
|
dev); |
|
struct device *child; |
|
|
|
child = device_find_child(&ctlr->dev, NULL, match_true); |
|
return sprintf(buf, "%s\n", |
|
child ? to_spi_device(child)->modalias : NULL); |
|
} |
|
|
|
static ssize_t slave_store(struct device *dev, struct device_attribute *attr, |
|
const char *buf, size_t count) |
|
{ |
|
struct spi_controller *ctlr = container_of(dev, struct spi_controller, |
|
dev); |
|
struct spi_device *spi; |
|
struct device *child; |
|
char name[32]; |
|
int rc; |
|
|
|
rc = sscanf(buf, "%31s", name); |
|
if (rc != 1 || !name[0]) |
|
return -EINVAL; |
|
|
|
child = device_find_child(&ctlr->dev, NULL, match_true); |
|
if (child) { |
|
/* Remove registered slave */ |
|
device_unregister(child); |
|
put_device(child); |
|
} |
|
|
|
if (strcmp(name, "(null)")) { |
|
/* Register new slave */ |
|
spi = spi_alloc_device(ctlr); |
|
if (!spi) |
|
return -ENOMEM; |
|
|
|
strlcpy(spi->modalias, name, sizeof(spi->modalias)); |
|
|
|
rc = spi_add_device(spi); |
|
if (rc) { |
|
spi_dev_put(spi); |
|
return rc; |
|
} |
|
} |
|
|
|
return count; |
|
} |
|
|
|
static DEVICE_ATTR_RW(slave); |
|
|
|
static struct attribute *spi_slave_attrs[] = { |
|
&dev_attr_slave.attr, |
|
NULL, |
|
}; |
|
|
|
static const struct attribute_group spi_slave_group = { |
|
.attrs = spi_slave_attrs, |
|
}; |
|
|
|
static const struct attribute_group *spi_slave_groups[] = { |
|
&spi_controller_statistics_group, |
|
&spi_slave_group, |
|
NULL, |
|
}; |
|
|
|
static struct class spi_slave_class = { |
|
.name = "spi_slave", |
|
.owner = THIS_MODULE, |
|
.dev_release = spi_controller_release, |
|
.dev_groups = spi_slave_groups, |
|
}; |
|
#else |
|
extern struct class spi_slave_class; /* dummy */ |
|
#endif |
|
|
|
/** |
|
* __spi_alloc_controller - allocate an SPI master or slave controller |
|
* @dev: the controller, possibly using the platform_bus |
|
* @size: how much zeroed driver-private data to allocate; the pointer to this |
|
* memory is in the driver_data field of the returned device, accessible |
|
* with spi_controller_get_devdata(); the memory is cacheline aligned; |
|
* drivers granting DMA access to portions of their private data need to |
|
* round up @size using ALIGN(size, dma_get_cache_alignment()). |
|
* @slave: flag indicating whether to allocate an SPI master (false) or SPI |
|
* slave (true) controller |
|
* Context: can sleep |
|
* |
|
* This call is used only by SPI controller drivers, which are the |
|
* only ones directly touching chip registers. It's how they allocate |
|
* an spi_controller structure, prior to calling spi_register_controller(). |
|
* |
|
* This must be called from context that can sleep. |
|
* |
|
* The caller is responsible for assigning the bus number and initializing the |
|
* controller's methods before calling spi_register_controller(); and (after |
|
* errors adding the device) calling spi_controller_put() to prevent a memory |
|
* leak. |
|
* |
|
* Return: the SPI controller structure on success, else NULL. |
|
*/ |
|
struct spi_controller *__spi_alloc_controller(struct device *dev, |
|
unsigned int size, bool slave) |
|
{ |
|
struct spi_controller *ctlr; |
|
size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment()); |
|
|
|
if (!dev) |
|
return NULL; |
|
|
|
ctlr = kzalloc(size + ctlr_size, GFP_KERNEL); |
|
if (!ctlr) |
|
return NULL; |
|
|
|
device_initialize(&ctlr->dev); |
|
ctlr->bus_num = -1; |
|
ctlr->num_chipselect = 1; |
|
ctlr->slave = slave; |
|
if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave) |
|
ctlr->dev.class = &spi_slave_class; |
|
else |
|
ctlr->dev.class = &spi_master_class; |
|
ctlr->dev.parent = dev; |
|
pm_suspend_ignore_children(&ctlr->dev, true); |
|
spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size); |
|
|
|
return ctlr; |
|
} |
|
EXPORT_SYMBOL_GPL(__spi_alloc_controller); |
|
|
|
static void devm_spi_release_controller(struct device *dev, void *ctlr) |
|
{ |
|
spi_controller_put(*(struct spi_controller **)ctlr); |
|
} |
|
|
|
/** |
|
* __devm_spi_alloc_controller - resource-managed __spi_alloc_controller() |
|
* @dev: physical device of SPI controller |
|
* @size: how much zeroed driver-private data to allocate |
|
* @slave: whether to allocate an SPI master (false) or SPI slave (true) |
|
* Context: can sleep |
|
* |
|
* Allocate an SPI controller and automatically release a reference on it |
|
* when @dev is unbound from its driver. Drivers are thus relieved from |
|
* having to call spi_controller_put(). |
|
* |
|
* The arguments to this function are identical to __spi_alloc_controller(). |
|
* |
|
* Return: the SPI controller structure on success, else NULL. |
|
*/ |
|
struct spi_controller *__devm_spi_alloc_controller(struct device *dev, |
|
unsigned int size, |
|
bool slave) |
|
{ |
|
struct spi_controller **ptr, *ctlr; |
|
|
|
ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr), |
|
GFP_KERNEL); |
|
if (!ptr) |
|
return NULL; |
|
|
|
ctlr = __spi_alloc_controller(dev, size, slave); |
|
if (ctlr) { |
|
ctlr->devm_allocated = true; |
|
*ptr = ctlr; |
|
devres_add(dev, ptr); |
|
} else { |
|
devres_free(ptr); |
|
} |
|
|
|
return ctlr; |
|
} |
|
EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller); |
|
|
|
#ifdef CONFIG_OF |
|
static int of_spi_get_gpio_numbers(struct spi_controller *ctlr) |
|
{ |
|
int nb, i, *cs; |
|
struct device_node *np = ctlr->dev.of_node; |
|
|
|
if (!np) |
|
return 0; |
|
|
|
nb = of_gpio_named_count(np, "cs-gpios"); |
|
ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect); |
|
|
|
/* Return error only for an incorrectly formed cs-gpios property */ |
|
if (nb == 0 || nb == -ENOENT) |
|
return 0; |
|
else if (nb < 0) |
|
return nb; |
|
|
|
cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int), |
|
GFP_KERNEL); |
|
ctlr->cs_gpios = cs; |
|
|
|
if (!ctlr->cs_gpios) |
|
return -ENOMEM; |
|
|
|
for (i = 0; i < ctlr->num_chipselect; i++) |
|
cs[i] = -ENOENT; |
|
|
|
for (i = 0; i < nb; i++) |
|
cs[i] = of_get_named_gpio(np, "cs-gpios", i); |
|
|
|
return 0; |
|
} |
|
#else |
|
static int of_spi_get_gpio_numbers(struct spi_controller *ctlr) |
|
{ |
|
return 0; |
|
} |
|
#endif |
|
|
|
/** |
|
* spi_get_gpio_descs() - grab chip select GPIOs for the master |
|
* @ctlr: The SPI master to grab GPIO descriptors for |
|
*/ |
|
static int spi_get_gpio_descs(struct spi_controller *ctlr) |
|
{ |
|
int nb, i; |
|
struct gpio_desc **cs; |
|
struct device *dev = &ctlr->dev; |
|
unsigned long native_cs_mask = 0; |
|
unsigned int num_cs_gpios = 0; |
|
|
|
nb = gpiod_count(dev, "cs"); |
|
ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect); |
|
|
|
/* No GPIOs at all is fine, else return the error */ |
|
if (nb == 0 || nb == -ENOENT) |
|
return 0; |
|
else if (nb < 0) |
|
return nb; |
|
|
|
cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs), |
|
GFP_KERNEL); |
|
if (!cs) |
|
return -ENOMEM; |
|
ctlr->cs_gpiods = cs; |
|
|
|
for (i = 0; i < nb; i++) { |
|
/* |
|
* Most chipselects are active low, the inverted |
|
* semantics are handled by special quirks in gpiolib, |
|
* so initializing them GPIOD_OUT_LOW here means |
|
* "unasserted", in most cases this will drive the physical |
|
* line high. |
|
*/ |
|
cs[i] = devm_gpiod_get_index_optional(dev, "cs", i, |
|
GPIOD_OUT_LOW); |
|
if (IS_ERR(cs[i])) |
|
return PTR_ERR(cs[i]); |
|
|
|
if (cs[i]) { |
|
/* |
|
* If we find a CS GPIO, name it after the device and |
|
* chip select line. |
|
*/ |
|
char *gpioname; |
|
|
|
gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d", |
|
dev_name(dev), i); |
|
if (!gpioname) |
|
return -ENOMEM; |
|
gpiod_set_consumer_name(cs[i], gpioname); |
|
num_cs_gpios++; |
|
continue; |
|
} |
|
|
|
if (ctlr->max_native_cs && i >= ctlr->max_native_cs) { |
|
dev_err(dev, "Invalid native chip select %d\n", i); |
|
return -EINVAL; |
|
} |
|
native_cs_mask |= BIT(i); |
|
} |
|
|
|
ctlr->unused_native_cs = ffz(native_cs_mask); |
|
if (num_cs_gpios && ctlr->max_native_cs && |
|
ctlr->unused_native_cs >= ctlr->max_native_cs) { |
|
dev_err(dev, "No unused native chip select available\n"); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int spi_controller_check_ops(struct spi_controller *ctlr) |
|
{ |
|
/* |
|
* The controller may implement only the high-level SPI-memory like |
|
* operations if it does not support regular SPI transfers, and this is |
|
* valid use case. |
|
* If ->mem_ops is NULL, we request that at least one of the |
|
* ->transfer_xxx() method be implemented. |
|
*/ |
|
if (ctlr->mem_ops) { |
|
if (!ctlr->mem_ops->exec_op) |
|
return -EINVAL; |
|
} else if (!ctlr->transfer && !ctlr->transfer_one && |
|
!ctlr->transfer_one_message) { |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* spi_register_controller - register SPI master or slave controller |
|
* @ctlr: initialized master, originally from spi_alloc_master() or |
|
* spi_alloc_slave() |
|
* Context: can sleep |
|
* |
|
* SPI controllers connect to their drivers using some non-SPI bus, |
|
* such as the platform bus. The final stage of probe() in that code |
|
* includes calling spi_register_controller() to hook up to this SPI bus glue. |
|
* |
|
* SPI controllers use board specific (often SOC specific) bus numbers, |
|
* and board-specific addressing for SPI devices combines those numbers |
|
* with chip select numbers. Since SPI does not directly support dynamic |
|
* device identification, boards need configuration tables telling which |
|
* chip is at which address. |
|
* |
|
* This must be called from context that can sleep. It returns zero on |
|
* success, else a negative error code (dropping the controller's refcount). |
|
* After a successful return, the caller is responsible for calling |
|
* spi_unregister_controller(). |
|
* |
|
* Return: zero on success, else a negative error code. |
|
*/ |
|
int spi_register_controller(struct spi_controller *ctlr) |
|
{ |
|
struct device *dev = ctlr->dev.parent; |
|
struct boardinfo *bi; |
|
int status; |
|
int id, first_dynamic; |
|
|
|
if (!dev) |
|
return -ENODEV; |
|
|
|
/* |
|
* Make sure all necessary hooks are implemented before registering |
|
* the SPI controller. |
|
*/ |
|
status = spi_controller_check_ops(ctlr); |
|
if (status) |
|
return status; |
|
|
|
if (ctlr->bus_num >= 0) { |
|
/* devices with a fixed bus num must check-in with the num */ |
|
mutex_lock(&board_lock); |
|
id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num, |
|
ctlr->bus_num + 1, GFP_KERNEL); |
|
mutex_unlock(&board_lock); |
|
if (WARN(id < 0, "couldn't get idr")) |
|
return id == -ENOSPC ? -EBUSY : id; |
|
ctlr->bus_num = id; |
|
} else if (ctlr->dev.of_node) { |
|
/* allocate dynamic bus number using Linux idr */ |
|
id = of_alias_get_id(ctlr->dev.of_node, "spi"); |
|
if (id >= 0) { |
|
ctlr->bus_num = id; |
|
mutex_lock(&board_lock); |
|
id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num, |
|
ctlr->bus_num + 1, GFP_KERNEL); |
|
mutex_unlock(&board_lock); |
|
if (WARN(id < 0, "couldn't get idr")) |
|
return id == -ENOSPC ? -EBUSY : id; |
|
} |
|
} |
|
if (ctlr->bus_num < 0) { |
|
first_dynamic = of_alias_get_highest_id("spi"); |
|
if (first_dynamic < 0) |
|
first_dynamic = 0; |
|
else |
|
first_dynamic++; |
|
|
|
mutex_lock(&board_lock); |
|
id = idr_alloc(&spi_master_idr, ctlr, first_dynamic, |
|
0, GFP_KERNEL); |
|
mutex_unlock(&board_lock); |
|
if (WARN(id < 0, "couldn't get idr")) |
|
return id; |
|
ctlr->bus_num = id; |
|
} |
|
INIT_LIST_HEAD(&ctlr->queue); |
|
spin_lock_init(&ctlr->queue_lock); |
|
spin_lock_init(&ctlr->bus_lock_spinlock); |
|
mutex_init(&ctlr->bus_lock_mutex); |
|
mutex_init(&ctlr->io_mutex); |
|
ctlr->bus_lock_flag = 0; |
|
init_completion(&ctlr->xfer_completion); |
|
if (!ctlr->max_dma_len) |
|
ctlr->max_dma_len = INT_MAX; |
|
|
|
/* register the device, then userspace will see it. |
|
* registration fails if the bus ID is in use. |
|
*/ |
|
dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num); |
|
|
|
if (!spi_controller_is_slave(ctlr)) { |
|
if (ctlr->use_gpio_descriptors) { |
|
status = spi_get_gpio_descs(ctlr); |
|
if (status) |
|
goto free_bus_id; |
|
/* |
|
* A controller using GPIO descriptors always |
|
* supports SPI_CS_HIGH if need be. |
|
*/ |
|
ctlr->mode_bits |= SPI_CS_HIGH; |
|
} else { |
|
/* Legacy code path for GPIOs from DT */ |
|
status = of_spi_get_gpio_numbers(ctlr); |
|
if (status) |
|
goto free_bus_id; |
|
} |
|
} |
|
|
|
/* |
|
* Even if it's just one always-selected device, there must |
|
* be at least one chipselect. |
|
*/ |
|
if (!ctlr->num_chipselect) { |
|
status = -EINVAL; |
|
goto free_bus_id; |
|
} |
|
|
|
status = device_add(&ctlr->dev); |
|
if (status < 0) |
|
goto free_bus_id; |
|
dev_dbg(dev, "registered %s %s\n", |
|
spi_controller_is_slave(ctlr) ? "slave" : "master", |
|
dev_name(&ctlr->dev)); |
|
|
|
/* |
|
* If we're using a queued driver, start the queue. Note that we don't |
|
* need the queueing logic if the driver is only supporting high-level |
|
* memory operations. |
|
*/ |
|
if (ctlr->transfer) { |
|
dev_info(dev, "controller is unqueued, this is deprecated\n"); |
|
} else if (ctlr->transfer_one || ctlr->transfer_one_message) { |
|
status = spi_controller_initialize_queue(ctlr); |
|
if (status) { |
|
device_del(&ctlr->dev); |
|
goto free_bus_id; |
|
} |
|
} |
|
/* add statistics */ |
|
spin_lock_init(&ctlr->statistics.lock); |
|
|
|
mutex_lock(&board_lock); |
|
list_add_tail(&ctlr->list, &spi_controller_list); |
|
list_for_each_entry(bi, &board_list, list) |
|
spi_match_controller_to_boardinfo(ctlr, &bi->board_info); |
|
mutex_unlock(&board_lock); |
|
|
|
/* Register devices from the device tree and ACPI */ |
|
of_register_spi_devices(ctlr); |
|
acpi_register_spi_devices(ctlr); |
|
return status; |
|
|
|
free_bus_id: |
|
mutex_lock(&board_lock); |
|
idr_remove(&spi_master_idr, ctlr->bus_num); |
|
mutex_unlock(&board_lock); |
|
return status; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_register_controller); |
|
|
|
static void devm_spi_unregister(struct device *dev, void *res) |
|
{ |
|
spi_unregister_controller(*(struct spi_controller **)res); |
|
} |
|
|
|
/** |
|
* devm_spi_register_controller - register managed SPI master or slave |
|
* controller |
|
* @dev: device managing SPI controller |
|
* @ctlr: initialized controller, originally from spi_alloc_master() or |
|
* spi_alloc_slave() |
|
* Context: can sleep |
|
* |
|
* Register a SPI device as with spi_register_controller() which will |
|
* automatically be unregistered and freed. |
|
* |
|
* Return: zero on success, else a negative error code. |
|
*/ |
|
int devm_spi_register_controller(struct device *dev, |
|
struct spi_controller *ctlr) |
|
{ |
|
struct spi_controller **ptr; |
|
int ret; |
|
|
|
ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL); |
|
if (!ptr) |
|
return -ENOMEM; |
|
|
|
ret = spi_register_controller(ctlr); |
|
if (!ret) { |
|
*ptr = ctlr; |
|
devres_add(dev, ptr); |
|
} else { |
|
devres_free(ptr); |
|
} |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(devm_spi_register_controller); |
|
|
|
static int __unregister(struct device *dev, void *null) |
|
{ |
|
spi_unregister_device(to_spi_device(dev)); |
|
return 0; |
|
} |
|
|
|
/** |
|
* spi_unregister_controller - unregister SPI master or slave controller |
|
* @ctlr: the controller being unregistered |
|
* Context: can sleep |
|
* |
|
* This call is used only by SPI controller drivers, which are the |
|
* only ones directly touching chip registers. |
|
* |
|
* This must be called from context that can sleep. |
|
* |
|
* Note that this function also drops a reference to the controller. |
|
*/ |
|
void spi_unregister_controller(struct spi_controller *ctlr) |
|
{ |
|
struct spi_controller *found; |
|
int id = ctlr->bus_num; |
|
|
|
/* Prevent addition of new devices, unregister existing ones */ |
|
if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) |
|
mutex_lock(&spi_add_lock); |
|
|
|
device_for_each_child(&ctlr->dev, NULL, __unregister); |
|
|
|
/* First make sure that this controller was ever added */ |
|
mutex_lock(&board_lock); |
|
found = idr_find(&spi_master_idr, id); |
|
mutex_unlock(&board_lock); |
|
if (ctlr->queued) { |
|
if (spi_destroy_queue(ctlr)) |
|
dev_err(&ctlr->dev, "queue remove failed\n"); |
|
} |
|
mutex_lock(&board_lock); |
|
list_del(&ctlr->list); |
|
mutex_unlock(&board_lock); |
|
|
|
device_del(&ctlr->dev); |
|
|
|
/* Release the last reference on the controller if its driver |
|
* has not yet been converted to devm_spi_alloc_master/slave(). |
|
*/ |
|
if (!ctlr->devm_allocated) |
|
put_device(&ctlr->dev); |
|
|
|
/* free bus id */ |
|
mutex_lock(&board_lock); |
|
if (found == ctlr) |
|
idr_remove(&spi_master_idr, id); |
|
mutex_unlock(&board_lock); |
|
|
|
if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) |
|
mutex_unlock(&spi_add_lock); |
|
} |
|
EXPORT_SYMBOL_GPL(spi_unregister_controller); |
|
|
|
int spi_controller_suspend(struct spi_controller *ctlr) |
|
{ |
|
int ret; |
|
|
|
/* Basically no-ops for non-queued controllers */ |
|
if (!ctlr->queued) |
|
return 0; |
|
|
|
ret = spi_stop_queue(ctlr); |
|
if (ret) |
|
dev_err(&ctlr->dev, "queue stop failed\n"); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_controller_suspend); |
|
|
|
int spi_controller_resume(struct spi_controller *ctlr) |
|
{ |
|
int ret; |
|
|
|
if (!ctlr->queued) |
|
return 0; |
|
|
|
ret = spi_start_queue(ctlr); |
|
if (ret) |
|
dev_err(&ctlr->dev, "queue restart failed\n"); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_controller_resume); |
|
|
|
static int __spi_controller_match(struct device *dev, const void *data) |
|
{ |
|
struct spi_controller *ctlr; |
|
const u16 *bus_num = data; |
|
|
|
ctlr = container_of(dev, struct spi_controller, dev); |
|
return ctlr->bus_num == *bus_num; |
|
} |
|
|
|
/** |
|
* spi_busnum_to_master - look up master associated with bus_num |
|
* @bus_num: the master's bus number |
|
* Context: can sleep |
|
* |
|
* This call may be used with devices that are registered after |
|
* arch init time. It returns a refcounted pointer to the relevant |
|
* spi_controller (which the caller must release), or NULL if there is |
|
* no such master registered. |
|
* |
|
* Return: the SPI master structure on success, else NULL. |
|
*/ |
|
struct spi_controller *spi_busnum_to_master(u16 bus_num) |
|
{ |
|
struct device *dev; |
|
struct spi_controller *ctlr = NULL; |
|
|
|
dev = class_find_device(&spi_master_class, NULL, &bus_num, |
|
__spi_controller_match); |
|
if (dev) |
|
ctlr = container_of(dev, struct spi_controller, dev); |
|
/* reference got in class_find_device */ |
|
return ctlr; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_busnum_to_master); |
|
|
|
/*-------------------------------------------------------------------------*/ |
|
|
|
/* Core methods for SPI resource management */ |
|
|
|
/** |
|
* spi_res_alloc - allocate a spi resource that is life-cycle managed |
|
* during the processing of a spi_message while using |
|
* spi_transfer_one |
|
* @spi: the spi device for which we allocate memory |
|
* @release: the release code to execute for this resource |
|
* @size: size to alloc and return |
|
* @gfp: GFP allocation flags |
|
* |
|
* Return: the pointer to the allocated data |
|
* |
|
* This may get enhanced in the future to allocate from a memory pool |
|
* of the @spi_device or @spi_controller to avoid repeated allocations. |
|
*/ |
|
void *spi_res_alloc(struct spi_device *spi, |
|
spi_res_release_t release, |
|
size_t size, gfp_t gfp) |
|
{ |
|
struct spi_res *sres; |
|
|
|
sres = kzalloc(sizeof(*sres) + size, gfp); |
|
if (!sres) |
|
return NULL; |
|
|
|
INIT_LIST_HEAD(&sres->entry); |
|
sres->release = release; |
|
|
|
return sres->data; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_res_alloc); |
|
|
|
/** |
|
* spi_res_free - free an spi resource |
|
* @res: pointer to the custom data of a resource |
|
* |
|
*/ |
|
void spi_res_free(void *res) |
|
{ |
|
struct spi_res *sres = container_of(res, struct spi_res, data); |
|
|
|
if (!res) |
|
return; |
|
|
|
WARN_ON(!list_empty(&sres->entry)); |
|
kfree(sres); |
|
} |
|
EXPORT_SYMBOL_GPL(spi_res_free); |
|
|
|
/** |
|
* spi_res_add - add a spi_res to the spi_message |
|
* @message: the spi message |
|
* @res: the spi_resource |
|
*/ |
|
void spi_res_add(struct spi_message *message, void *res) |
|
{ |
|
struct spi_res *sres = container_of(res, struct spi_res, data); |
|
|
|
WARN_ON(!list_empty(&sres->entry)); |
|
list_add_tail(&sres->entry, &message->resources); |
|
} |
|
EXPORT_SYMBOL_GPL(spi_res_add); |
|
|
|
/** |
|
* spi_res_release - release all spi resources for this message |
|
* @ctlr: the @spi_controller |
|
* @message: the @spi_message |
|
*/ |
|
void spi_res_release(struct spi_controller *ctlr, struct spi_message *message) |
|
{ |
|
struct spi_res *res, *tmp; |
|
|
|
list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) { |
|
if (res->release) |
|
res->release(ctlr, message, res->data); |
|
|
|
list_del(&res->entry); |
|
|
|
kfree(res); |
|
} |
|
} |
|
EXPORT_SYMBOL_GPL(spi_res_release); |
|
|
|
/*-------------------------------------------------------------------------*/ |
|
|
|
/* Core methods for spi_message alterations */ |
|
|
|
static void __spi_replace_transfers_release(struct spi_controller *ctlr, |
|
struct spi_message *msg, |
|
void *res) |
|
{ |
|
struct spi_replaced_transfers *rxfer = res; |
|
size_t i; |
|
|
|
/* call extra callback if requested */ |
|
if (rxfer->release) |
|
rxfer->release(ctlr, msg, res); |
|
|
|
/* insert replaced transfers back into the message */ |
|
list_splice(&rxfer->replaced_transfers, rxfer->replaced_after); |
|
|
|
/* remove the formerly inserted entries */ |
|
for (i = 0; i < rxfer->inserted; i++) |
|
list_del(&rxfer->inserted_transfers[i].transfer_list); |
|
} |
|
|
|
/** |
|
* spi_replace_transfers - replace transfers with several transfers |
|
* and register change with spi_message.resources |
|
* @msg: the spi_message we work upon |
|
* @xfer_first: the first spi_transfer we want to replace |
|
* @remove: number of transfers to remove |
|
* @insert: the number of transfers we want to insert instead |
|
* @release: extra release code necessary in some circumstances |
|
* @extradatasize: extra data to allocate (with alignment guarantees |
|
* of struct @spi_transfer) |
|
* @gfp: gfp flags |
|
* |
|
* Returns: pointer to @spi_replaced_transfers, |
|
* PTR_ERR(...) in case of errors. |
|
*/ |
|
struct spi_replaced_transfers *spi_replace_transfers( |
|
struct spi_message *msg, |
|
struct spi_transfer *xfer_first, |
|
size_t remove, |
|
size_t insert, |
|
spi_replaced_release_t release, |
|
size_t extradatasize, |
|
gfp_t gfp) |
|
{ |
|
struct spi_replaced_transfers *rxfer; |
|
struct spi_transfer *xfer; |
|
size_t i; |
|
|
|
/* allocate the structure using spi_res */ |
|
rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release, |
|
struct_size(rxfer, inserted_transfers, insert) |
|
+ extradatasize, |
|
gfp); |
|
if (!rxfer) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
/* the release code to invoke before running the generic release */ |
|
rxfer->release = release; |
|
|
|
/* assign extradata */ |
|
if (extradatasize) |
|
rxfer->extradata = |
|
&rxfer->inserted_transfers[insert]; |
|
|
|
/* init the replaced_transfers list */ |
|
INIT_LIST_HEAD(&rxfer->replaced_transfers); |
|
|
|
/* assign the list_entry after which we should reinsert |
|
* the @replaced_transfers - it may be spi_message.messages! |
|
*/ |
|
rxfer->replaced_after = xfer_first->transfer_list.prev; |
|
|
|
/* remove the requested number of transfers */ |
|
for (i = 0; i < remove; i++) { |
|
/* if the entry after replaced_after it is msg->transfers |
|
* then we have been requested to remove more transfers |
|
* than are in the list |
|
*/ |
|
if (rxfer->replaced_after->next == &msg->transfers) { |
|
dev_err(&msg->spi->dev, |
|
"requested to remove more spi_transfers than are available\n"); |
|
/* insert replaced transfers back into the message */ |
|
list_splice(&rxfer->replaced_transfers, |
|
rxfer->replaced_after); |
|
|
|
/* free the spi_replace_transfer structure */ |
|
spi_res_free(rxfer); |
|
|
|
/* and return with an error */ |
|
return ERR_PTR(-EINVAL); |
|
} |
|
|
|
/* remove the entry after replaced_after from list of |
|
* transfers and add it to list of replaced_transfers |
|
*/ |
|
list_move_tail(rxfer->replaced_after->next, |
|
&rxfer->replaced_transfers); |
|
} |
|
|
|
/* create copy of the given xfer with identical settings |
|
* based on the first transfer to get removed |
|
*/ |
|
for (i = 0; i < insert; i++) { |
|
/* we need to run in reverse order */ |
|
xfer = &rxfer->inserted_transfers[insert - 1 - i]; |
|
|
|
/* copy all spi_transfer data */ |
|
memcpy(xfer, xfer_first, sizeof(*xfer)); |
|
|
|
/* add to list */ |
|
list_add(&xfer->transfer_list, rxfer->replaced_after); |
|
|
|
/* clear cs_change and delay for all but the last */ |
|
if (i) { |
|
xfer->cs_change = false; |
|
xfer->delay_usecs = 0; |
|
xfer->delay.value = 0; |
|
} |
|
} |
|
|
|
/* set up inserted */ |
|
rxfer->inserted = insert; |
|
|
|
/* and register it with spi_res/spi_message */ |
|
spi_res_add(msg, rxfer); |
|
|
|
return rxfer; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_replace_transfers); |
|
|
|
static int __spi_split_transfer_maxsize(struct spi_controller *ctlr, |
|
struct spi_message *msg, |
|
struct spi_transfer **xferp, |
|
size_t maxsize, |
|
gfp_t gfp) |
|
{ |
|
struct spi_transfer *xfer = *xferp, *xfers; |
|
struct spi_replaced_transfers *srt; |
|
size_t offset; |
|
size_t count, i; |
|
|
|
/* calculate how many we have to replace */ |
|
count = DIV_ROUND_UP(xfer->len, maxsize); |
|
|
|
/* create replacement */ |
|
srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp); |
|
if (IS_ERR(srt)) |
|
return PTR_ERR(srt); |
|
xfers = srt->inserted_transfers; |
|
|
|
/* now handle each of those newly inserted spi_transfers |
|
* note that the replacements spi_transfers all are preset |
|
* to the same values as *xferp, so tx_buf, rx_buf and len |
|
* are all identical (as well as most others) |
|
* so we just have to fix up len and the pointers. |
|
* |
|
* this also includes support for the depreciated |
|
* spi_message.is_dma_mapped interface |
|
*/ |
|
|
|
/* the first transfer just needs the length modified, so we |
|
* run it outside the loop |
|
*/ |
|
xfers[0].len = min_t(size_t, maxsize, xfer[0].len); |
|
|
|
/* all the others need rx_buf/tx_buf also set */ |
|
for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) { |
|
/* update rx_buf, tx_buf and dma */ |
|
if (xfers[i].rx_buf) |
|
xfers[i].rx_buf += offset; |
|
if (xfers[i].rx_dma) |
|
xfers[i].rx_dma += offset; |
|
if (xfers[i].tx_buf) |
|
xfers[i].tx_buf += offset; |
|
if (xfers[i].tx_dma) |
|
xfers[i].tx_dma += offset; |
|
|
|
/* update length */ |
|
xfers[i].len = min(maxsize, xfers[i].len - offset); |
|
} |
|
|
|
/* we set up xferp to the last entry we have inserted, |
|
* so that we skip those already split transfers |
|
*/ |
|
*xferp = &xfers[count - 1]; |
|
|
|
/* increment statistics counters */ |
|
SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, |
|
transfers_split_maxsize); |
|
SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics, |
|
transfers_split_maxsize); |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* spi_split_transfers_maxsize - split spi transfers into multiple transfers |
|
* when an individual transfer exceeds a |
|
* certain size |
|
* @ctlr: the @spi_controller for this transfer |
|
* @msg: the @spi_message to transform |
|
* @maxsize: the maximum when to apply this |
|
* @gfp: GFP allocation flags |
|
* |
|
* Return: status of transformation |
|
*/ |
|
int spi_split_transfers_maxsize(struct spi_controller *ctlr, |
|
struct spi_message *msg, |
|
size_t maxsize, |
|
gfp_t gfp) |
|
{ |
|
struct spi_transfer *xfer; |
|
int ret; |
|
|
|
/* iterate over the transfer_list, |
|
* but note that xfer is advanced to the last transfer inserted |
|
* to avoid checking sizes again unnecessarily (also xfer does |
|
* potentiall belong to a different list by the time the |
|
* replacement has happened |
|
*/ |
|
list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
|
if (xfer->len > maxsize) { |
|
ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer, |
|
maxsize, gfp); |
|
if (ret) |
|
return ret; |
|
} |
|
} |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize); |
|
|
|
/*-------------------------------------------------------------------------*/ |
|
|
|
/* Core methods for SPI controller protocol drivers. Some of the |
|
* other core methods are currently defined as inline functions. |
|
*/ |
|
|
|
static int __spi_validate_bits_per_word(struct spi_controller *ctlr, |
|
u8 bits_per_word) |
|
{ |
|
if (ctlr->bits_per_word_mask) { |
|
/* Only 32 bits fit in the mask */ |
|
if (bits_per_word > 32) |
|
return -EINVAL; |
|
if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word))) |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* spi_setup - setup SPI mode and clock rate |
|
* @spi: the device whose settings are being modified |
|
* Context: can sleep, and no requests are queued to the device |
|
* |
|
* SPI protocol drivers may need to update the transfer mode if the |
|
* device doesn't work with its default. They may likewise need |
|
* to update clock rates or word sizes from initial values. This function |
|
* changes those settings, and must be called from a context that can sleep. |
|
* Except for SPI_CS_HIGH, which takes effect immediately, the changes take |
|
* effect the next time the device is selected and data is transferred to |
|
* or from it. When this function returns, the spi device is deselected. |
|
* |
|
* Note that this call will fail if the protocol driver specifies an option |
|
* that the underlying controller or its driver does not support. For |
|
* example, not all hardware supports wire transfers using nine bit words, |
|
* LSB-first wire encoding, or active-high chipselects. |
|
* |
|
* Return: zero on success, else a negative error code. |
|
*/ |
|
int spi_setup(struct spi_device *spi) |
|
{ |
|
struct spi_controller *ctlr = spi->controller; |
|
unsigned bad_bits, ugly_bits; |
|
int status; |
|
|
|
/* |
|
* check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO |
|
* are set at the same time |
|
*/ |
|
if ((hweight_long(spi->mode & |
|
(SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) || |
|
(hweight_long(spi->mode & |
|
(SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) { |
|
dev_err(&spi->dev, |
|
"setup: can not select any two of dual, quad and no-rx/tx at the same time\n"); |
|
return -EINVAL; |
|
} |
|
/* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden |
|
*/ |
|
if ((spi->mode & SPI_3WIRE) && (spi->mode & |
|
(SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL | |
|
SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL))) |
|
return -EINVAL; |
|
|
|
if (ctlr->use_gpio_descriptors && ctlr->cs_gpiods && |
|
ctlr->cs_gpiods[spi->chip_select] && !(spi->mode & SPI_CS_HIGH)) { |
|
dev_dbg(&spi->dev, |
|
"setup: forcing CS_HIGH (use_gpio_descriptors)\n"); |
|
spi->mode |= SPI_CS_HIGH; |
|
} |
|
|
|
/* help drivers fail *cleanly* when they need options |
|
* that aren't supported with their current controller |
|
* SPI_CS_WORD has a fallback software implementation, |
|
* so it is ignored here. |
|
*/ |
|
bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD | |
|
SPI_NO_TX | SPI_NO_RX); |
|
/* nothing prevents from working with active-high CS in case if it |
|
* is driven by GPIO. |
|
*/ |
|
if (gpio_is_valid(spi->cs_gpio)) |
|
bad_bits &= ~SPI_CS_HIGH; |
|
ugly_bits = bad_bits & |
|
(SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL | |
|
SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL); |
|
if (ugly_bits) { |
|
dev_warn(&spi->dev, |
|
"setup: ignoring unsupported mode bits %x\n", |
|
ugly_bits); |
|
spi->mode &= ~ugly_bits; |
|
bad_bits &= ~ugly_bits; |
|
} |
|
if (bad_bits) { |
|
dev_err(&spi->dev, "setup: unsupported mode bits %x\n", |
|
bad_bits); |
|
return -EINVAL; |
|
} |
|
|
|
if (!spi->bits_per_word) |
|
spi->bits_per_word = 8; |
|
|
|
status = __spi_validate_bits_per_word(spi->controller, |
|
spi->bits_per_word); |
|
if (status) |
|
return status; |
|
|
|
if (spi->controller->max_speed_hz && |
|
(!spi->max_speed_hz || |
|
spi->max_speed_hz > spi->controller->max_speed_hz)) |
|
spi->max_speed_hz = spi->controller->max_speed_hz; |
|
|
|
mutex_lock(&spi->controller->io_mutex); |
|
|
|
if (spi->controller->setup) |
|
status = spi->controller->setup(spi); |
|
|
|
if (spi->controller->auto_runtime_pm && spi->controller->set_cs) { |
|
status = pm_runtime_get_sync(spi->controller->dev.parent); |
|
if (status < 0) { |
|
mutex_unlock(&spi->controller->io_mutex); |
|
pm_runtime_put_noidle(spi->controller->dev.parent); |
|
dev_err(&spi->controller->dev, "Failed to power device: %d\n", |
|
status); |
|
return status; |
|
} |
|
|
|
/* |
|
* We do not want to return positive value from pm_runtime_get, |
|
* there are many instances of devices calling spi_setup() and |
|
* checking for a non-zero return value instead of a negative |
|
* return value. |
|
*/ |
|
status = 0; |
|
|
|
spi_set_cs(spi, false, true); |
|
pm_runtime_mark_last_busy(spi->controller->dev.parent); |
|
pm_runtime_put_autosuspend(spi->controller->dev.parent); |
|
} else { |
|
spi_set_cs(spi, false, true); |
|
} |
|
|
|
mutex_unlock(&spi->controller->io_mutex); |
|
|
|
if (spi->rt && !spi->controller->rt) { |
|
spi->controller->rt = true; |
|
spi_set_thread_rt(spi->controller); |
|
} |
|
|
|
dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n", |
|
(int) (spi->mode & (SPI_CPOL | SPI_CPHA)), |
|
(spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", |
|
(spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", |
|
(spi->mode & SPI_3WIRE) ? "3wire, " : "", |
|
(spi->mode & SPI_LOOP) ? "loopback, " : "", |
|
spi->bits_per_word, spi->max_speed_hz, |
|
status); |
|
|
|
return status; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_setup); |
|
|
|
/** |
|
* spi_set_cs_timing - configure CS setup, hold, and inactive delays |
|
* @spi: the device that requires specific CS timing configuration |
|
* @setup: CS setup time specified via @spi_delay |
|
* @hold: CS hold time specified via @spi_delay |
|
* @inactive: CS inactive delay between transfers specified via @spi_delay |
|
* |
|
* Return: zero on success, else a negative error code. |
|
*/ |
|
int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup, |
|
struct spi_delay *hold, struct spi_delay *inactive) |
|
{ |
|
struct device *parent = spi->controller->dev.parent; |
|
size_t len; |
|
int status; |
|
|
|
if (spi->controller->set_cs_timing && |
|
!(spi->cs_gpiod || gpio_is_valid(spi->cs_gpio))) { |
|
mutex_lock(&spi->controller->io_mutex); |
|
|
|
if (spi->controller->auto_runtime_pm) { |
|
status = pm_runtime_get_sync(parent); |
|
if (status < 0) { |
|
mutex_unlock(&spi->controller->io_mutex); |
|
pm_runtime_put_noidle(parent); |
|
dev_err(&spi->controller->dev, "Failed to power device: %d\n", |
|
status); |
|
return status; |
|
} |
|
|
|
status = spi->controller->set_cs_timing(spi, setup, |
|
hold, inactive); |
|
pm_runtime_mark_last_busy(parent); |
|
pm_runtime_put_autosuspend(parent); |
|
} else { |
|
status = spi->controller->set_cs_timing(spi, setup, hold, |
|
inactive); |
|
} |
|
|
|
mutex_unlock(&spi->controller->io_mutex); |
|
return status; |
|
} |
|
|
|
if ((setup && setup->unit == SPI_DELAY_UNIT_SCK) || |
|
(hold && hold->unit == SPI_DELAY_UNIT_SCK) || |
|
(inactive && inactive->unit == SPI_DELAY_UNIT_SCK)) { |
|
dev_err(&spi->dev, |
|
"Clock-cycle delays for CS not supported in SW mode\n"); |
|
return -ENOTSUPP; |
|
} |
|
|
|
len = sizeof(struct spi_delay); |
|
|
|
/* copy delays to controller */ |
|
if (setup) |
|
memcpy(&spi->controller->cs_setup, setup, len); |
|
else |
|
memset(&spi->controller->cs_setup, 0, len); |
|
|
|
if (hold) |
|
memcpy(&spi->controller->cs_hold, hold, len); |
|
else |
|
memset(&spi->controller->cs_hold, 0, len); |
|
|
|
if (inactive) |
|
memcpy(&spi->controller->cs_inactive, inactive, len); |
|
else |
|
memset(&spi->controller->cs_inactive, 0, len); |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_set_cs_timing); |
|
|
|
static int _spi_xfer_word_delay_update(struct spi_transfer *xfer, |
|
struct spi_device *spi) |
|
{ |
|
int delay1, delay2; |
|
|
|
delay1 = spi_delay_to_ns(&xfer->word_delay, xfer); |
|
if (delay1 < 0) |
|
return delay1; |
|
|
|
delay2 = spi_delay_to_ns(&spi->word_delay, xfer); |
|
if (delay2 < 0) |
|
return delay2; |
|
|
|
if (delay1 < delay2) |
|
memcpy(&xfer->word_delay, &spi->word_delay, |
|
sizeof(xfer->word_delay)); |
|
|
|
return 0; |
|
} |
|
|
|
static int __spi_validate(struct spi_device *spi, struct spi_message *message) |
|
{ |
|
struct spi_controller *ctlr = spi->controller; |
|
struct spi_transfer *xfer; |
|
int w_size; |
|
|
|
if (list_empty(&message->transfers)) |
|
return -EINVAL; |
|
|
|
/* If an SPI controller does not support toggling the CS line on each |
|
* transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO |
|
* for the CS line, we can emulate the CS-per-word hardware function by |
|
* splitting transfers into one-word transfers and ensuring that |
|
* cs_change is set for each transfer. |
|
*/ |
|
if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) || |
|
spi->cs_gpiod || |
|
gpio_is_valid(spi->cs_gpio))) { |
|
size_t maxsize; |
|
int ret; |
|
|
|
maxsize = (spi->bits_per_word + 7) / 8; |
|
|
|
/* spi_split_transfers_maxsize() requires message->spi */ |
|
message->spi = spi; |
|
|
|
ret = spi_split_transfers_maxsize(ctlr, message, maxsize, |
|
GFP_KERNEL); |
|
if (ret) |
|
return ret; |
|
|
|
list_for_each_entry(xfer, &message->transfers, transfer_list) { |
|
/* don't change cs_change on the last entry in the list */ |
|
if (list_is_last(&xfer->transfer_list, &message->transfers)) |
|
break; |
|
xfer->cs_change = 1; |
|
} |
|
} |
|
|
|
/* Half-duplex links include original MicroWire, and ones with |
|
* only one data pin like SPI_3WIRE (switches direction) or where |
|
* either MOSI or MISO is missing. They can also be caused by |
|
* software limitations. |
|
*/ |
|
if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) || |
|
(spi->mode & SPI_3WIRE)) { |
|
unsigned flags = ctlr->flags; |
|
|
|
list_for_each_entry(xfer, &message->transfers, transfer_list) { |
|
if (xfer->rx_buf && xfer->tx_buf) |
|
return -EINVAL; |
|
if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf) |
|
return -EINVAL; |
|
if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf) |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
/** |
|
* Set transfer bits_per_word and max speed as spi device default if |
|
* it is not set for this transfer. |
|
* Set transfer tx_nbits and rx_nbits as single transfer default |
|
* (SPI_NBITS_SINGLE) if it is not set for this transfer. |
|
* Ensure transfer word_delay is at least as long as that required by |
|
* device itself. |
|
*/ |
|
message->frame_length = 0; |
|
list_for_each_entry(xfer, &message->transfers, transfer_list) { |
|
xfer->effective_speed_hz = 0; |
|
message->frame_length += xfer->len; |
|
if (!xfer->bits_per_word) |
|
xfer->bits_per_word = spi->bits_per_word; |
|
|
|
if (!xfer->speed_hz) |
|
xfer->speed_hz = spi->max_speed_hz; |
|
|
|
if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz) |
|
xfer->speed_hz = ctlr->max_speed_hz; |
|
|
|
if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word)) |
|
return -EINVAL; |
|
|
|
/* |
|
* SPI transfer length should be multiple of SPI word size |
|
* where SPI word size should be power-of-two multiple |
|
*/ |
|
if (xfer->bits_per_word <= 8) |
|
w_size = 1; |
|
else if (xfer->bits_per_word <= 16) |
|
w_size = 2; |
|
else |
|
w_size = 4; |
|
|
|
/* No partial transfers accepted */ |
|
if (xfer->len % w_size) |
|
return -EINVAL; |
|
|
|
if (xfer->speed_hz && ctlr->min_speed_hz && |
|
xfer->speed_hz < ctlr->min_speed_hz) |
|
return -EINVAL; |
|
|
|
if (xfer->tx_buf && !xfer->tx_nbits) |
|
xfer->tx_nbits = SPI_NBITS_SINGLE; |
|
if (xfer->rx_buf && !xfer->rx_nbits) |
|
xfer->rx_nbits = SPI_NBITS_SINGLE; |
|
/* check transfer tx/rx_nbits: |
|
* 1. check the value matches one of single, dual and quad |
|
* 2. check tx/rx_nbits match the mode in spi_device |
|
*/ |
|
if (xfer->tx_buf) { |
|
if (spi->mode & SPI_NO_TX) |
|
return -EINVAL; |
|
if (xfer->tx_nbits != SPI_NBITS_SINGLE && |
|
xfer->tx_nbits != SPI_NBITS_DUAL && |
|
xfer->tx_nbits != SPI_NBITS_QUAD) |
|
return -EINVAL; |
|
if ((xfer->tx_nbits == SPI_NBITS_DUAL) && |
|
!(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) |
|
return -EINVAL; |
|
if ((xfer->tx_nbits == SPI_NBITS_QUAD) && |
|
!(spi->mode & SPI_TX_QUAD)) |
|
return -EINVAL; |
|
} |
|
/* check transfer rx_nbits */ |
|
if (xfer->rx_buf) { |
|
if (spi->mode & SPI_NO_RX) |
|
return -EINVAL; |
|
if (xfer->rx_nbits != SPI_NBITS_SINGLE && |
|
xfer->rx_nbits != SPI_NBITS_DUAL && |
|
xfer->rx_nbits != SPI_NBITS_QUAD) |
|
return -EINVAL; |
|
if ((xfer->rx_nbits == SPI_NBITS_DUAL) && |
|
!(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) |
|
return -EINVAL; |
|
if ((xfer->rx_nbits == SPI_NBITS_QUAD) && |
|
!(spi->mode & SPI_RX_QUAD)) |
|
return -EINVAL; |
|
} |
|
|
|
if (_spi_xfer_word_delay_update(xfer, spi)) |
|
return -EINVAL; |
|
} |
|
|
|
message->status = -EINPROGRESS; |
|
|
|
return 0; |
|
} |
|
|
|
static int __spi_async(struct spi_device *spi, struct spi_message *message) |
|
{ |
|
struct spi_controller *ctlr = spi->controller; |
|
struct spi_transfer *xfer; |
|
|
|
/* |
|
* Some controllers do not support doing regular SPI transfers. Return |
|
* ENOTSUPP when this is the case. |
|
*/ |
|
if (!ctlr->transfer) |
|
return -ENOTSUPP; |
|
|
|
message->spi = spi; |
|
|
|
SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async); |
|
SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async); |
|
|
|
trace_spi_message_submit(message); |
|
|
|
if (!ctlr->ptp_sts_supported) { |
|
list_for_each_entry(xfer, &message->transfers, transfer_list) { |
|
xfer->ptp_sts_word_pre = 0; |
|
ptp_read_system_prets(xfer->ptp_sts); |
|
} |
|
} |
|
|
|
return ctlr->transfer(spi, message); |
|
} |
|
|
|
/** |
|
* spi_async - asynchronous SPI transfer |
|
* @spi: device with which data will be exchanged |
|
* @message: describes the data transfers, including completion callback |
|
* Context: any (irqs may be blocked, etc) |
|
* |
|
* This call may be used in_irq and other contexts which can't sleep, |
|
* as well as from task contexts which can sleep. |
|
* |
|
* The completion callback is invoked in a context which can't sleep. |
|
* Before that invocation, the value of message->status is undefined. |
|
* When the callback is issued, message->status holds either zero (to |
|
* indicate complete success) or a negative error code. After that |
|
* callback returns, the driver which issued the transfer request may |
|
* deallocate the associated memory; it's no longer in use by any SPI |
|
* core or controller driver code. |
|
* |
|
* Note that although all messages to a spi_device are handled in |
|
* FIFO order, messages may go to different devices in other orders. |
|
* Some device might be higher priority, or have various "hard" access |
|
* time requirements, for example. |
|
* |
|
* On detection of any fault during the transfer, processing of |
|
* the entire message is aborted, and the device is deselected. |
|
* Until returning from the associated message completion callback, |
|
* no other spi_message queued to that device will be processed. |
|
* (This rule applies equally to all the synchronous transfer calls, |
|
* which are wrappers around this core asynchronous primitive.) |
|
* |
|
* Return: zero on success, else a negative error code. |
|
*/ |
|
int spi_async(struct spi_device *spi, struct spi_message *message) |
|
{ |
|
struct spi_controller *ctlr = spi->controller; |
|
int ret; |
|
unsigned long flags; |
|
|
|
ret = __spi_validate(spi, message); |
|
if (ret != 0) |
|
return ret; |
|
|
|
spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); |
|
|
|
if (ctlr->bus_lock_flag) |
|
ret = -EBUSY; |
|
else |
|
ret = __spi_async(spi, message); |
|
|
|
spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_async); |
|
|
|
/** |
|
* spi_async_locked - version of spi_async with exclusive bus usage |
|
* @spi: device with which data will be exchanged |
|
* @message: describes the data transfers, including completion callback |
|
* Context: any (irqs may be blocked, etc) |
|
* |
|
* This call may be used in_irq and other contexts which can't sleep, |
|
* as well as from task contexts which can sleep. |
|
* |
|
* The completion callback is invoked in a context which can't sleep. |
|
* Before that invocation, the value of message->status is undefined. |
|
* When the callback is issued, message->status holds either zero (to |
|
* indicate complete success) or a negative error code. After that |
|
* callback returns, the driver which issued the transfer request may |
|
* deallocate the associated memory; it's no longer in use by any SPI |
|
* core or controller driver code. |
|
* |
|
* Note that although all messages to a spi_device are handled in |
|
* FIFO order, messages may go to different devices in other orders. |
|
* Some device might be higher priority, or have various "hard" access |
|
* time requirements, for example. |
|
* |
|
* On detection of any fault during the transfer, processing of |
|
* the entire message is aborted, and the device is deselected. |
|
* Until returning from the associated message completion callback, |
|
* no other spi_message queued to that device will be processed. |
|
* (This rule applies equally to all the synchronous transfer calls, |
|
* which are wrappers around this core asynchronous primitive.) |
|
* |
|
* Return: zero on success, else a negative error code. |
|
*/ |
|
int spi_async_locked(struct spi_device *spi, struct spi_message *message) |
|
{ |
|
struct spi_controller *ctlr = spi->controller; |
|
int ret; |
|
unsigned long flags; |
|
|
|
ret = __spi_validate(spi, message); |
|
if (ret != 0) |
|
return ret; |
|
|
|
spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); |
|
|
|
ret = __spi_async(spi, message); |
|
|
|
spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); |
|
|
|
return ret; |
|
|
|
} |
|
EXPORT_SYMBOL_GPL(spi_async_locked); |
|
|
|
/*-------------------------------------------------------------------------*/ |
|
|
|
/* Utility methods for SPI protocol drivers, layered on |
|
* top of the core. Some other utility methods are defined as |
|
* inline functions. |
|
*/ |
|
|
|
static void spi_complete(void *arg) |
|
{ |
|
complete(arg); |
|
} |
|
|
|
static int __spi_sync(struct spi_device *spi, struct spi_message *message) |
|
{ |
|
DECLARE_COMPLETION_ONSTACK(done); |
|
int status; |
|
struct spi_controller *ctlr = spi->controller; |
|
unsigned long flags; |
|
|
|
status = __spi_validate(spi, message); |
|
if (status != 0) |
|
return status; |
|
|
|
message->complete = spi_complete; |
|
message->context = &done; |
|
message->spi = spi; |
|
|
|
SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync); |
|
SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync); |
|
|
|
/* If we're not using the legacy transfer method then we will |
|
* try to transfer in the calling context so special case. |
|
* This code would be less tricky if we could remove the |
|
* support for driver implemented message queues. |
|
*/ |
|
if (ctlr->transfer == spi_queued_transfer) { |
|
spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); |
|
|
|
trace_spi_message_submit(message); |
|
|
|
status = __spi_queued_transfer(spi, message, false); |
|
|
|
spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); |
|
} else { |
|
status = spi_async_locked(spi, message); |
|
} |
|
|
|
if (status == 0) { |
|
/* Push out the messages in the calling context if we |
|
* can. |
|
*/ |
|
if (ctlr->transfer == spi_queued_transfer) { |
|
SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, |
|
spi_sync_immediate); |
|
SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, |
|
spi_sync_immediate); |
|
__spi_pump_messages(ctlr, false); |
|
} |
|
|
|
wait_for_completion(&done); |
|
status = message->status; |
|
} |
|
message->context = NULL; |
|
return status; |
|
} |
|
|
|
/** |
|
* spi_sync - blocking/synchronous SPI data transfers |
|
* @spi: device with which data will be exchanged |
|
* @message: describes the data transfers |
|
* Context: can sleep |
|
* |
|
* This call may only be used from a context that may sleep. The sleep |
|
* is non-interruptible, and has no timeout. Low-overhead controller |
|
* drivers may DMA directly into and out of the message buffers. |
|
* |
|
* Note that the SPI device's chip select is active during the message, |
|
* and then is normally disabled between messages. Drivers for some |
|
* frequently-used devices may want to minimize costs of selecting a chip, |
|
* by leaving it selected in anticipation that the next message will go |
|
* to the same chip. (That may increase power usage.) |
|
* |
|
* Also, the caller is guaranteeing that the memory associated with the |
|
* message will not be freed before this call returns. |
|
* |
|
* Return: zero on success, else a negative error code. |
|
*/ |
|
int spi_sync(struct spi_device *spi, struct spi_message *message) |
|
{ |
|
int ret; |
|
|
|
mutex_lock(&spi->controller->bus_lock_mutex); |
|
ret = __spi_sync(spi, message); |
|
mutex_unlock(&spi->controller->bus_lock_mutex); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_sync); |
|
|
|
/** |
|
* spi_sync_locked - version of spi_sync with exclusive bus usage |
|
* @spi: device with which data will be exchanged |
|
* @message: describes the data transfers |
|
* Context: can sleep |
|
* |
|
* This call may only be used from a context that may sleep. The sleep |
|
* is non-interruptible, and has no timeout. Low-overhead controller |
|
* drivers may DMA directly into and out of the message buffers. |
|
* |
|
* This call should be used by drivers that require exclusive access to the |
|
* SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must |
|
* be released by a spi_bus_unlock call when the exclusive access is over. |
|
* |
|
* Return: zero on success, else a negative error code. |
|
*/ |
|
int spi_sync_locked(struct spi_device *spi, struct spi_message *message) |
|
{ |
|
return __spi_sync(spi, message); |
|
} |
|
EXPORT_SYMBOL_GPL(spi_sync_locked); |
|
|
|
/** |
|
* spi_bus_lock - obtain a lock for exclusive SPI bus usage |
|
* @ctlr: SPI bus master that should be locked for exclusive bus access |
|
* Context: can sleep |
|
* |
|
* This call may only be used from a context that may sleep. The sleep |
|
* is non-interruptible, and has no timeout. |
|
* |
|
* This call should be used by drivers that require exclusive access to the |
|
* SPI bus. The SPI bus must be released by a spi_bus_unlock call when the |
|
* exclusive access is over. Data transfer must be done by spi_sync_locked |
|
* and spi_async_locked calls when the SPI bus lock is held. |
|
* |
|
* Return: always zero. |
|
*/ |
|
int spi_bus_lock(struct spi_controller *ctlr) |
|
{ |
|
unsigned long flags; |
|
|
|
mutex_lock(&ctlr->bus_lock_mutex); |
|
|
|
spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); |
|
ctlr->bus_lock_flag = 1; |
|
spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); |
|
|
|
/* mutex remains locked until spi_bus_unlock is called */ |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_bus_lock); |
|
|
|
/** |
|
* spi_bus_unlock - release the lock for exclusive SPI bus usage |
|
* @ctlr: SPI bus master that was locked for exclusive bus access |
|
* Context: can sleep |
|
* |
|
* This call may only be used from a context that may sleep. The sleep |
|
* is non-interruptible, and has no timeout. |
|
* |
|
* This call releases an SPI bus lock previously obtained by an spi_bus_lock |
|
* call. |
|
* |
|
* Return: always zero. |
|
*/ |
|
int spi_bus_unlock(struct spi_controller *ctlr) |
|
{ |
|
ctlr->bus_lock_flag = 0; |
|
|
|
mutex_unlock(&ctlr->bus_lock_mutex); |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_bus_unlock); |
|
|
|
/* portable code must never pass more than 32 bytes */ |
|
#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES) |
|
|
|
static u8 *buf; |
|
|
|
/** |
|
* spi_write_then_read - SPI synchronous write followed by read |
|
* @spi: device with which data will be exchanged |
|
* @txbuf: data to be written (need not be dma-safe) |
|
* @n_tx: size of txbuf, in bytes |
|
* @rxbuf: buffer into which data will be read (need not be dma-safe) |
|
* @n_rx: size of rxbuf, in bytes |
|
* Context: can sleep |
|
* |
|
* This performs a half duplex MicroWire style transaction with the |
|
* device, sending txbuf and then reading rxbuf. The return value |
|
* is zero for success, else a negative errno status code. |
|
* This call may only be used from a context that may sleep. |
|
* |
|
* Parameters to this routine are always copied using a small buffer. |
|
* Performance-sensitive or bulk transfer code should instead use |
|
* spi_{async,sync}() calls with dma-safe buffers. |
|
* |
|
* Return: zero on success, else a negative error code. |
|
*/ |
|
int spi_write_then_read(struct spi_device *spi, |
|
const void *txbuf, unsigned n_tx, |
|
void *rxbuf, unsigned n_rx) |
|
{ |
|
static DEFINE_MUTEX(lock); |
|
|
|
int status; |
|
struct spi_message message; |
|
struct spi_transfer x[2]; |
|
u8 *local_buf; |
|
|
|
/* Use preallocated DMA-safe buffer if we can. We can't avoid |
|
* copying here, (as a pure convenience thing), but we can |
|
* keep heap costs out of the hot path unless someone else is |
|
* using the pre-allocated buffer or the transfer is too large. |
|
*/ |
|
if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { |
|
local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), |
|
GFP_KERNEL | GFP_DMA); |
|
if (!local_buf) |
|
return -ENOMEM; |
|
} else { |
|
local_buf = buf; |
|
} |
|
|
|
spi_message_init(&message); |
|
memset(x, 0, sizeof(x)); |
|
if (n_tx) { |
|
x[0].len = n_tx; |
|
spi_message_add_tail(&x[0], &message); |
|
} |
|
if (n_rx) { |
|
x[1].len = n_rx; |
|
spi_message_add_tail(&x[1], &message); |
|
} |
|
|
|
memcpy(local_buf, txbuf, n_tx); |
|
x[0].tx_buf = local_buf; |
|
x[1].rx_buf = local_buf + n_tx; |
|
|
|
/* do the i/o */ |
|
status = spi_sync(spi, &message); |
|
if (status == 0) |
|
memcpy(rxbuf, x[1].rx_buf, n_rx); |
|
|
|
if (x[0].tx_buf == buf) |
|
mutex_unlock(&lock); |
|
else |
|
kfree(local_buf); |
|
|
|
return status; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_write_then_read); |
|
|
|
/*-------------------------------------------------------------------------*/ |
|
|
|
#if IS_ENABLED(CONFIG_OF) |
|
/* must call put_device() when done with returned spi_device device */ |
|
struct spi_device *of_find_spi_device_by_node(struct device_node *node) |
|
{ |
|
struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node); |
|
|
|
return dev ? to_spi_device(dev) : NULL; |
|
} |
|
EXPORT_SYMBOL_GPL(of_find_spi_device_by_node); |
|
#endif /* IS_ENABLED(CONFIG_OF) */ |
|
|
|
#if IS_ENABLED(CONFIG_OF_DYNAMIC) |
|
/* the spi controllers are not using spi_bus, so we find it with another way */ |
|
static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node) |
|
{ |
|
struct device *dev; |
|
|
|
dev = class_find_device_by_of_node(&spi_master_class, node); |
|
if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE)) |
|
dev = class_find_device_by_of_node(&spi_slave_class, node); |
|
if (!dev) |
|
return NULL; |
|
|
|
/* reference got in class_find_device */ |
|
return container_of(dev, struct spi_controller, dev); |
|
} |
|
|
|
static int of_spi_notify(struct notifier_block *nb, unsigned long action, |
|
void *arg) |
|
{ |
|
struct of_reconfig_data *rd = arg; |
|
struct spi_controller *ctlr; |
|
struct spi_device *spi; |
|
|
|
switch (of_reconfig_get_state_change(action, arg)) { |
|
case OF_RECONFIG_CHANGE_ADD: |
|
ctlr = of_find_spi_controller_by_node(rd->dn->parent); |
|
if (ctlr == NULL) |
|
return NOTIFY_OK; /* not for us */ |
|
|
|
if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { |
|
put_device(&ctlr->dev); |
|
return NOTIFY_OK; |
|
} |
|
|
|
spi = of_register_spi_device(ctlr, rd->dn); |
|
put_device(&ctlr->dev); |
|
|
|
if (IS_ERR(spi)) { |
|
pr_err("%s: failed to create for '%pOF'\n", |
|
__func__, rd->dn); |
|
of_node_clear_flag(rd->dn, OF_POPULATED); |
|
return notifier_from_errno(PTR_ERR(spi)); |
|
} |
|
break; |
|
|
|
case OF_RECONFIG_CHANGE_REMOVE: |
|
/* already depopulated? */ |
|
if (!of_node_check_flag(rd->dn, OF_POPULATED)) |
|
return NOTIFY_OK; |
|
|
|
/* find our device by node */ |
|
spi = of_find_spi_device_by_node(rd->dn); |
|
if (spi == NULL) |
|
return NOTIFY_OK; /* no? not meant for us */ |
|
|
|
/* unregister takes one ref away */ |
|
spi_unregister_device(spi); |
|
|
|
/* and put the reference of the find */ |
|
put_device(&spi->dev); |
|
break; |
|
} |
|
|
|
return NOTIFY_OK; |
|
} |
|
|
|
static struct notifier_block spi_of_notifier = { |
|
.notifier_call = of_spi_notify, |
|
}; |
|
#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ |
|
extern struct notifier_block spi_of_notifier; |
|
#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ |
|
|
|
#if IS_ENABLED(CONFIG_ACPI) |
|
static int spi_acpi_controller_match(struct device *dev, const void *data) |
|
{ |
|
return ACPI_COMPANION(dev->parent) == data; |
|
} |
|
|
|
static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev) |
|
{ |
|
struct device *dev; |
|
|
|
dev = class_find_device(&spi_master_class, NULL, adev, |
|
spi_acpi_controller_match); |
|
if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE)) |
|
dev = class_find_device(&spi_slave_class, NULL, adev, |
|
spi_acpi_controller_match); |
|
if (!dev) |
|
return NULL; |
|
|
|
return container_of(dev, struct spi_controller, dev); |
|
} |
|
|
|
static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev) |
|
{ |
|
struct device *dev; |
|
|
|
dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev); |
|
return to_spi_device(dev); |
|
} |
|
|
|
static int acpi_spi_notify(struct notifier_block *nb, unsigned long value, |
|
void *arg) |
|
{ |
|
struct acpi_device *adev = arg; |
|
struct spi_controller *ctlr; |
|
struct spi_device *spi; |
|
|
|
switch (value) { |
|
case ACPI_RECONFIG_DEVICE_ADD: |
|
ctlr = acpi_spi_find_controller_by_adev(adev->parent); |
|
if (!ctlr) |
|
break; |
|
|
|
acpi_register_spi_device(ctlr, adev); |
|
put_device(&ctlr->dev); |
|
break; |
|
case ACPI_RECONFIG_DEVICE_REMOVE: |
|
if (!acpi_device_enumerated(adev)) |
|
break; |
|
|
|
spi = acpi_spi_find_device_by_adev(adev); |
|
if (!spi) |
|
break; |
|
|
|
spi_unregister_device(spi); |
|
put_device(&spi->dev); |
|
break; |
|
} |
|
|
|
return NOTIFY_OK; |
|
} |
|
|
|
static struct notifier_block spi_acpi_notifier = { |
|
.notifier_call = acpi_spi_notify, |
|
}; |
|
#else |
|
extern struct notifier_block spi_acpi_notifier; |
|
#endif |
|
|
|
static int __init spi_init(void) |
|
{ |
|
int status; |
|
|
|
buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); |
|
if (!buf) { |
|
status = -ENOMEM; |
|
goto err0; |
|
} |
|
|
|
status = bus_register(&spi_bus_type); |
|
if (status < 0) |
|
goto err1; |
|
|
|
status = class_register(&spi_master_class); |
|
if (status < 0) |
|
goto err2; |
|
|
|
if (IS_ENABLED(CONFIG_SPI_SLAVE)) { |
|
status = class_register(&spi_slave_class); |
|
if (status < 0) |
|
goto err3; |
|
} |
|
|
|
if (IS_ENABLED(CONFIG_OF_DYNAMIC)) |
|
WARN_ON(of_reconfig_notifier_register(&spi_of_notifier)); |
|
if (IS_ENABLED(CONFIG_ACPI)) |
|
WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier)); |
|
|
|
return 0; |
|
|
|
err3: |
|
class_unregister(&spi_master_class); |
|
err2: |
|
bus_unregister(&spi_bus_type); |
|
err1: |
|
kfree(buf); |
|
buf = NULL; |
|
err0: |
|
return status; |
|
} |
|
|
|
/* board_info is normally registered in arch_initcall(), |
|
* but even essential drivers wait till later |
|
* |
|
* REVISIT only boardinfo really needs static linking. the rest (device and |
|
* driver registration) _could_ be dynamically linked (modular) ... costs |
|
* include needing to have boardinfo data structures be much more public. |
|
*/ |
|
postcore_initcall(spi_init);
|
|
|