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234 lines
5.6 KiB
234 lines
5.6 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* adcxx.c |
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* |
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* The adcxx4s is an AD converter family from National Semiconductor (NS). |
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* |
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* Copyright (c) 2008 Marc Pignat <[email protected]> |
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* |
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* The adcxx4s communicates with a host processor via an SPI/Microwire Bus |
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* interface. This driver supports the whole family of devices with name |
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* ADC<bb><c>S<sss>, where |
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* * bb is the resolution in number of bits (8, 10, 12) |
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* * c is the number of channels (1, 2, 4, 8) |
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* * sss is the maximum conversion speed (021 for 200 kSPS, 051 for 500 kSPS |
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* and 101 for 1 MSPS) |
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* |
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* Complete datasheets are available at National's website here: |
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* http://www.national.com/ds/DC/ADC<bb><c>S<sss>.pdf |
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* |
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* Handling of 8, 10 and 12 bits converters are the same, the |
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* unavailable bits are 0 :) |
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*/ |
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#include <linux/init.h> |
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#include <linux/module.h> |
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#include <linux/kernel.h> |
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#include <linux/slab.h> |
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#include <linux/device.h> |
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#include <linux/err.h> |
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#include <linux/sysfs.h> |
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#include <linux/hwmon.h> |
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#include <linux/hwmon-sysfs.h> |
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#include <linux/mutex.h> |
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#include <linux/mod_devicetable.h> |
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#include <linux/spi/spi.h> |
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#define DRVNAME "adcxx" |
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struct adcxx { |
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struct device *hwmon_dev; |
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struct mutex lock; |
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u32 channels; |
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u32 reference; /* in millivolts */ |
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}; |
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/* sysfs hook function */ |
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static ssize_t adcxx_show(struct device *dev, |
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struct device_attribute *devattr, char *buf) |
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{ |
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struct spi_device *spi = to_spi_device(dev); |
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struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
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struct adcxx *adc = spi_get_drvdata(spi); |
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u8 tx_buf[2]; |
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u8 rx_buf[2]; |
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int status; |
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u32 value; |
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if (mutex_lock_interruptible(&adc->lock)) |
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return -ERESTARTSYS; |
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if (adc->channels == 1) { |
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status = spi_read(spi, rx_buf, sizeof(rx_buf)); |
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} else { |
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tx_buf[0] = attr->index << 3; /* other bits are don't care */ |
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status = spi_write_then_read(spi, tx_buf, sizeof(tx_buf), |
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rx_buf, sizeof(rx_buf)); |
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} |
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if (status < 0) { |
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dev_warn(dev, "SPI synch. transfer failed with status %d\n", |
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status); |
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goto out; |
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} |
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value = (rx_buf[0] << 8) + rx_buf[1]; |
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dev_dbg(dev, "raw value = 0x%x\n", value); |
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value = value * adc->reference >> 12; |
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status = sprintf(buf, "%d\n", value); |
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out: |
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mutex_unlock(&adc->lock); |
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return status; |
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} |
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static ssize_t adcxx_min_show(struct device *dev, |
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struct device_attribute *devattr, char *buf) |
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{ |
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/* The minimum reference is 0 for this chip family */ |
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return sprintf(buf, "0\n"); |
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} |
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static ssize_t adcxx_max_show(struct device *dev, |
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struct device_attribute *devattr, char *buf) |
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{ |
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struct spi_device *spi = to_spi_device(dev); |
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struct adcxx *adc = spi_get_drvdata(spi); |
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u32 reference; |
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if (mutex_lock_interruptible(&adc->lock)) |
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return -ERESTARTSYS; |
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reference = adc->reference; |
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mutex_unlock(&adc->lock); |
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return sprintf(buf, "%d\n", reference); |
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} |
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static ssize_t adcxx_max_store(struct device *dev, |
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struct device_attribute *devattr, |
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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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struct adcxx *adc = spi_get_drvdata(spi); |
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unsigned long value; |
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if (kstrtoul(buf, 10, &value)) |
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return -EINVAL; |
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if (mutex_lock_interruptible(&adc->lock)) |
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return -ERESTARTSYS; |
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adc->reference = value; |
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mutex_unlock(&adc->lock); |
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return count; |
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} |
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static ssize_t adcxx_name_show(struct device *dev, |
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struct device_attribute *devattr, char *buf) |
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{ |
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return sprintf(buf, "%s\n", to_spi_device(dev)->modalias); |
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} |
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static struct sensor_device_attribute ad_input[] = { |
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SENSOR_ATTR_RO(name, adcxx_name, 0), |
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SENSOR_ATTR_RO(in_min, adcxx_min, 0), |
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SENSOR_ATTR_RW(in_max, adcxx_max, 0), |
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SENSOR_ATTR_RO(in0_input, adcxx, 0), |
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SENSOR_ATTR_RO(in1_input, adcxx, 1), |
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SENSOR_ATTR_RO(in2_input, adcxx, 2), |
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SENSOR_ATTR_RO(in3_input, adcxx, 3), |
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SENSOR_ATTR_RO(in4_input, adcxx, 4), |
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SENSOR_ATTR_RO(in5_input, adcxx, 5), |
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SENSOR_ATTR_RO(in6_input, adcxx, 6), |
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SENSOR_ATTR_RO(in7_input, adcxx, 7), |
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}; |
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/*----------------------------------------------------------------------*/ |
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static int adcxx_probe(struct spi_device *spi) |
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{ |
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int channels = spi_get_device_id(spi)->driver_data; |
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struct adcxx *adc; |
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int status; |
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int i; |
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adc = devm_kzalloc(&spi->dev, sizeof(*adc), GFP_KERNEL); |
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if (!adc) |
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return -ENOMEM; |
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/* set a default value for the reference */ |
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adc->reference = 3300; |
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adc->channels = channels; |
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mutex_init(&adc->lock); |
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mutex_lock(&adc->lock); |
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spi_set_drvdata(spi, adc); |
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for (i = 0; i < 3 + adc->channels; i++) { |
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status = device_create_file(&spi->dev, &ad_input[i].dev_attr); |
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if (status) { |
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dev_err(&spi->dev, "device_create_file failed.\n"); |
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goto out_err; |
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} |
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} |
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adc->hwmon_dev = hwmon_device_register(&spi->dev); |
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if (IS_ERR(adc->hwmon_dev)) { |
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dev_err(&spi->dev, "hwmon_device_register failed.\n"); |
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status = PTR_ERR(adc->hwmon_dev); |
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goto out_err; |
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} |
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mutex_unlock(&adc->lock); |
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return 0; |
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out_err: |
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for (i--; i >= 0; i--) |
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device_remove_file(&spi->dev, &ad_input[i].dev_attr); |
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mutex_unlock(&adc->lock); |
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return status; |
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} |
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static int adcxx_remove(struct spi_device *spi) |
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{ |
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struct adcxx *adc = spi_get_drvdata(spi); |
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int i; |
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mutex_lock(&adc->lock); |
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hwmon_device_unregister(adc->hwmon_dev); |
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for (i = 0; i < 3 + adc->channels; i++) |
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device_remove_file(&spi->dev, &ad_input[i].dev_attr); |
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mutex_unlock(&adc->lock); |
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return 0; |
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} |
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static const struct spi_device_id adcxx_ids[] = { |
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{ "adcxx1s", 1 }, |
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{ "adcxx2s", 2 }, |
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{ "adcxx4s", 4 }, |
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{ "adcxx8s", 8 }, |
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{ }, |
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}; |
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MODULE_DEVICE_TABLE(spi, adcxx_ids); |
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static struct spi_driver adcxx_driver = { |
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.driver = { |
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.name = "adcxx", |
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}, |
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.id_table = adcxx_ids, |
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.probe = adcxx_probe, |
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.remove = adcxx_remove, |
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}; |
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module_spi_driver(adcxx_driver); |
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MODULE_AUTHOR("Marc Pignat"); |
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MODULE_DESCRIPTION("National Semiconductor adcxx8sxxx Linux driver"); |
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MODULE_LICENSE("GPL");
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