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2466 lines
67 KiB
2466 lines
67 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Linux I2C core |
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* |
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* Copyright (C) 1995-99 Simon G. Vogl |
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* With some changes from Kyösti Mälkki <[email protected]> |
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* Mux support by Rodolfo Giometti <[email protected]> and |
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* Michael Lawnick <[email protected]> |
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* |
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* Copyright (C) 2013-2017 Wolfram Sang <[email protected]> |
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*/ |
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|
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#define pr_fmt(fmt) "i2c-core: " fmt |
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|
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#include <dt-bindings/i2c/i2c.h> |
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#include <linux/acpi.h> |
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#include <linux/clk/clk-conf.h> |
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#include <linux/completion.h> |
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#include <linux/delay.h> |
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#include <linux/err.h> |
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#include <linux/errno.h> |
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#include <linux/gpio/consumer.h> |
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#include <linux/i2c.h> |
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#include <linux/i2c-smbus.h> |
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#include <linux/idr.h> |
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#include <linux/init.h> |
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#include <linux/irqflags.h> |
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#include <linux/jump_label.h> |
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#include <linux/kernel.h> |
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#include <linux/module.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.h> |
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#include <linux/of_irq.h> |
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#include <linux/pinctrl/consumer.h> |
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#include <linux/pm_domain.h> |
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#include <linux/pm_runtime.h> |
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#include <linux/pm_wakeirq.h> |
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#include <linux/property.h> |
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#include <linux/rwsem.h> |
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#include <linux/slab.h> |
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#include "i2c-core.h" |
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|
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#define CREATE_TRACE_POINTS |
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#include <trace/events/i2c.h> |
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|
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#define I2C_ADDR_OFFSET_TEN_BIT 0xa000 |
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#define I2C_ADDR_OFFSET_SLAVE 0x1000 |
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|
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#define I2C_ADDR_7BITS_MAX 0x77 |
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#define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1) |
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#define I2C_ADDR_DEVICE_ID 0x7c |
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|
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/* |
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* core_lock protects i2c_adapter_idr, and guarantees that device detection, |
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* deletion of detected devices are serialized |
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*/ |
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static DEFINE_MUTEX(core_lock); |
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static DEFINE_IDR(i2c_adapter_idr); |
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static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
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static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key); |
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static bool is_registered; |
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int i2c_transfer_trace_reg(void) |
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{ |
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static_branch_inc(&i2c_trace_msg_key); |
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return 0; |
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} |
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|
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void i2c_transfer_trace_unreg(void) |
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{ |
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static_branch_dec(&i2c_trace_msg_key); |
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} |
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const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
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const struct i2c_client *client) |
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{ |
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if (!(id && client)) |
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return NULL; |
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|
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while (id->name[0]) { |
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if (strcmp(client->name, id->name) == 0) |
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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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EXPORT_SYMBOL_GPL(i2c_match_id); |
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static int i2c_device_match(struct device *dev, struct device_driver *drv) |
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{ |
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struct i2c_client *client = i2c_verify_client(dev); |
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struct i2c_driver *driver; |
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/* Attempt an OF style match */ |
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if (i2c_of_match_device(drv->of_match_table, client)) |
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return 1; |
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/* Then ACPI style match */ |
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if (acpi_driver_match_device(dev, drv)) |
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return 1; |
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driver = to_i2c_driver(drv); |
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/* Finally an I2C match */ |
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if (i2c_match_id(driver->id_table, client)) |
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return 1; |
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return 0; |
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} |
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static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
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{ |
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struct i2c_client *client = to_i2c_client(dev); |
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int rc; |
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|
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rc = of_device_uevent_modalias(dev, env); |
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if (rc != -ENODEV) |
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return 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", I2C_MODULE_PREFIX, client->name); |
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} |
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|
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/* i2c bus recovery routines */ |
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static int get_scl_gpio_value(struct i2c_adapter *adap) |
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{ |
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return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod); |
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} |
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static void set_scl_gpio_value(struct i2c_adapter *adap, int val) |
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{ |
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gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val); |
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} |
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static int get_sda_gpio_value(struct i2c_adapter *adap) |
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{ |
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return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod); |
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} |
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static void set_sda_gpio_value(struct i2c_adapter *adap, int val) |
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{ |
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gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val); |
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} |
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static int i2c_generic_bus_free(struct i2c_adapter *adap) |
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{ |
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struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; |
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int ret = -EOPNOTSUPP; |
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|
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if (bri->get_bus_free) |
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ret = bri->get_bus_free(adap); |
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else if (bri->get_sda) |
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ret = bri->get_sda(adap); |
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if (ret < 0) |
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return ret; |
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return ret ? 0 : -EBUSY; |
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} |
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/* |
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* We are generating clock pulses. ndelay() determines durating of clk pulses. |
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* We will generate clock with rate 100 KHz and so duration of both clock levels |
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* is: delay in ns = (10^6 / 100) / 2 |
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*/ |
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#define RECOVERY_NDELAY 5000 |
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#define RECOVERY_CLK_CNT 9 |
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|
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int i2c_generic_scl_recovery(struct i2c_adapter *adap) |
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{ |
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struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; |
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int i = 0, scl = 1, ret = 0; |
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if (bri->prepare_recovery) |
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bri->prepare_recovery(adap); |
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if (bri->pinctrl) |
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pinctrl_select_state(bri->pinctrl, bri->pins_gpio); |
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|
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/* |
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* If we can set SDA, we will always create a STOP to ensure additional |
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* pulses will do no harm. This is achieved by letting SDA follow SCL |
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* half a cycle later. Check the 'incomplete_write_byte' fault injector |
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* for details. Note that we must honour tsu:sto, 4us, but lets use 5us |
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* here for simplicity. |
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*/ |
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bri->set_scl(adap, scl); |
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ndelay(RECOVERY_NDELAY); |
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if (bri->set_sda) |
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bri->set_sda(adap, scl); |
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ndelay(RECOVERY_NDELAY / 2); |
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|
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/* |
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* By this time SCL is high, as we need to give 9 falling-rising edges |
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*/ |
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while (i++ < RECOVERY_CLK_CNT * 2) { |
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if (scl) { |
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/* SCL shouldn't be low here */ |
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if (!bri->get_scl(adap)) { |
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dev_err(&adap->dev, |
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"SCL is stuck low, exit recovery\n"); |
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ret = -EBUSY; |
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break; |
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} |
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} |
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scl = !scl; |
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bri->set_scl(adap, scl); |
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/* Creating STOP again, see above */ |
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if (scl) { |
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/* Honour minimum tsu:sto */ |
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ndelay(RECOVERY_NDELAY); |
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} else { |
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/* Honour minimum tf and thd:dat */ |
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ndelay(RECOVERY_NDELAY / 2); |
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} |
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if (bri->set_sda) |
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bri->set_sda(adap, scl); |
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ndelay(RECOVERY_NDELAY / 2); |
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if (scl) { |
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ret = i2c_generic_bus_free(adap); |
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if (ret == 0) |
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break; |
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} |
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} |
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/* If we can't check bus status, assume recovery worked */ |
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if (ret == -EOPNOTSUPP) |
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ret = 0; |
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|
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if (bri->unprepare_recovery) |
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bri->unprepare_recovery(adap); |
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if (bri->pinctrl) |
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pinctrl_select_state(bri->pinctrl, bri->pins_default); |
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|
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return ret; |
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} |
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EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery); |
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int i2c_recover_bus(struct i2c_adapter *adap) |
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{ |
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if (!adap->bus_recovery_info) |
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return -EOPNOTSUPP; |
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dev_dbg(&adap->dev, "Trying i2c bus recovery\n"); |
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return adap->bus_recovery_info->recover_bus(adap); |
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} |
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EXPORT_SYMBOL_GPL(i2c_recover_bus); |
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static void i2c_gpio_init_pinctrl_recovery(struct i2c_adapter *adap) |
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{ |
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struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; |
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struct device *dev = &adap->dev; |
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struct pinctrl *p = bri->pinctrl; |
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|
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/* |
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* we can't change states without pinctrl, so remove the states if |
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* populated |
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*/ |
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if (!p) { |
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bri->pins_default = NULL; |
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bri->pins_gpio = NULL; |
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return; |
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} |
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if (!bri->pins_default) { |
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bri->pins_default = pinctrl_lookup_state(p, |
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PINCTRL_STATE_DEFAULT); |
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if (IS_ERR(bri->pins_default)) { |
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dev_dbg(dev, PINCTRL_STATE_DEFAULT " state not found for GPIO recovery\n"); |
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bri->pins_default = NULL; |
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} |
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} |
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if (!bri->pins_gpio) { |
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bri->pins_gpio = pinctrl_lookup_state(p, "gpio"); |
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if (IS_ERR(bri->pins_gpio)) |
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bri->pins_gpio = pinctrl_lookup_state(p, "recovery"); |
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if (IS_ERR(bri->pins_gpio)) { |
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dev_dbg(dev, "no gpio or recovery state found for GPIO recovery\n"); |
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bri->pins_gpio = NULL; |
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} |
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} |
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/* for pinctrl state changes, we need all the information */ |
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if (bri->pins_default && bri->pins_gpio) { |
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dev_info(dev, "using pinctrl states for GPIO recovery"); |
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} else { |
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bri->pinctrl = NULL; |
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bri->pins_default = NULL; |
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bri->pins_gpio = NULL; |
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} |
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} |
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static int i2c_gpio_init_generic_recovery(struct i2c_adapter *adap) |
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{ |
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struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; |
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struct device *dev = &adap->dev; |
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struct gpio_desc *gpiod; |
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int ret = 0; |
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/* |
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* don't touch the recovery information if the driver is not using |
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* generic SCL recovery |
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*/ |
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if (bri->recover_bus && bri->recover_bus != i2c_generic_scl_recovery) |
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return 0; |
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/* |
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* pins might be taken as GPIO, so we should inform pinctrl about |
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* this and move the state to GPIO |
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*/ |
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if (bri->pinctrl) |
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pinctrl_select_state(bri->pinctrl, bri->pins_gpio); |
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/* |
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* if there is incomplete or no recovery information, see if generic |
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* GPIO recovery is available |
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*/ |
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if (!bri->scl_gpiod) { |
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gpiod = devm_gpiod_get(dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN); |
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if (PTR_ERR(gpiod) == -EPROBE_DEFER) { |
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ret = -EPROBE_DEFER; |
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goto cleanup_pinctrl_state; |
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} |
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if (!IS_ERR(gpiod)) { |
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bri->scl_gpiod = gpiod; |
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bri->recover_bus = i2c_generic_scl_recovery; |
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dev_info(dev, "using generic GPIOs for recovery\n"); |
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} |
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} |
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/* SDA GPIOD line is optional, so we care about DEFER only */ |
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if (!bri->sda_gpiod) { |
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/* |
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* We have SCL. Pull SCL low and wait a bit so that SDA glitches |
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* have no effect. |
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*/ |
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gpiod_direction_output(bri->scl_gpiod, 0); |
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udelay(10); |
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gpiod = devm_gpiod_get(dev, "sda", GPIOD_IN); |
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|
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/* Wait a bit in case of a SDA glitch, and then release SCL. */ |
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udelay(10); |
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gpiod_direction_output(bri->scl_gpiod, 1); |
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|
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if (PTR_ERR(gpiod) == -EPROBE_DEFER) { |
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ret = -EPROBE_DEFER; |
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goto cleanup_pinctrl_state; |
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} |
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if (!IS_ERR(gpiod)) |
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bri->sda_gpiod = gpiod; |
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} |
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cleanup_pinctrl_state: |
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/* change the state of the pins back to their default state */ |
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if (bri->pinctrl) |
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pinctrl_select_state(bri->pinctrl, bri->pins_default); |
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|
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return ret; |
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} |
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static int i2c_gpio_init_recovery(struct i2c_adapter *adap) |
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{ |
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i2c_gpio_init_pinctrl_recovery(adap); |
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return i2c_gpio_init_generic_recovery(adap); |
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} |
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static int i2c_init_recovery(struct i2c_adapter *adap) |
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{ |
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struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; |
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char *err_str, *err_level = KERN_ERR; |
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if (!bri) |
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return 0; |
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if (i2c_gpio_init_recovery(adap) == -EPROBE_DEFER) |
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return -EPROBE_DEFER; |
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if (!bri->recover_bus) { |
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err_str = "no suitable method provided"; |
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err_level = KERN_DEBUG; |
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goto err; |
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} |
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if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) { |
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bri->get_scl = get_scl_gpio_value; |
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bri->set_scl = set_scl_gpio_value; |
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if (bri->sda_gpiod) { |
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bri->get_sda = get_sda_gpio_value; |
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/* FIXME: add proper flag instead of '0' once available */ |
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if (gpiod_get_direction(bri->sda_gpiod) == 0) |
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bri->set_sda = set_sda_gpio_value; |
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} |
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} else if (bri->recover_bus == i2c_generic_scl_recovery) { |
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/* Generic SCL recovery */ |
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if (!bri->set_scl || !bri->get_scl) { |
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err_str = "no {get|set}_scl() found"; |
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goto err; |
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} |
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if (!bri->set_sda && !bri->get_sda) { |
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err_str = "either get_sda() or set_sda() needed"; |
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goto err; |
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} |
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} |
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|
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return 0; |
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err: |
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dev_printk(err_level, &adap->dev, "Not using recovery: %s\n", err_str); |
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adap->bus_recovery_info = NULL; |
|
|
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return -EINVAL; |
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} |
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|
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static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client) |
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{ |
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struct i2c_adapter *adap = client->adapter; |
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unsigned int irq; |
|
|
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if (!adap->host_notify_domain) |
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return -ENXIO; |
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|
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if (client->flags & I2C_CLIENT_TEN) |
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return -EINVAL; |
|
|
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irq = irq_create_mapping(adap->host_notify_domain, client->addr); |
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|
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return irq > 0 ? irq : -ENXIO; |
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} |
|
|
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static int i2c_device_probe(struct device *dev) |
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{ |
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struct i2c_client *client = i2c_verify_client(dev); |
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struct i2c_driver *driver; |
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int status; |
|
|
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if (!client) |
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return 0; |
|
|
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client->irq = client->init_irq; |
|
|
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if (!client->irq) { |
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int irq = -ENOENT; |
|
|
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if (client->flags & I2C_CLIENT_HOST_NOTIFY) { |
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dev_dbg(dev, "Using Host Notify IRQ\n"); |
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/* Keep adapter active when Host Notify is required */ |
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pm_runtime_get_sync(&client->adapter->dev); |
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irq = i2c_smbus_host_notify_to_irq(client); |
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} else if (dev->of_node) { |
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irq = of_irq_get_byname(dev->of_node, "irq"); |
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if (irq == -EINVAL || irq == -ENODATA) |
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irq = of_irq_get(dev->of_node, 0); |
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} else if (ACPI_COMPANION(dev)) { |
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irq = i2c_acpi_get_irq(client); |
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} |
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if (irq == -EPROBE_DEFER) { |
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status = irq; |
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goto put_sync_adapter; |
|
} |
|
|
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if (irq < 0) |
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irq = 0; |
|
|
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client->irq = irq; |
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} |
|
|
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driver = to_i2c_driver(dev->driver); |
|
|
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/* |
|
* An I2C ID table is not mandatory, if and only if, a suitable OF |
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* or ACPI ID table is supplied for the probing device. |
|
*/ |
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if (!driver->id_table && |
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!acpi_driver_match_device(dev, dev->driver) && |
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!i2c_of_match_device(dev->driver->of_match_table, client)) { |
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status = -ENODEV; |
|
goto put_sync_adapter; |
|
} |
|
|
|
if (client->flags & I2C_CLIENT_WAKE) { |
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int wakeirq; |
|
|
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wakeirq = of_irq_get_byname(dev->of_node, "wakeup"); |
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if (wakeirq == -EPROBE_DEFER) { |
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status = wakeirq; |
|
goto put_sync_adapter; |
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} |
|
|
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device_init_wakeup(&client->dev, true); |
|
|
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if (wakeirq > 0 && wakeirq != client->irq) |
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status = dev_pm_set_dedicated_wake_irq(dev, wakeirq); |
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else if (client->irq > 0) |
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status = dev_pm_set_wake_irq(dev, client->irq); |
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else |
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status = 0; |
|
|
|
if (status) |
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dev_warn(&client->dev, "failed to set up wakeup irq\n"); |
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} |
|
|
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dev_dbg(dev, "probe\n"); |
|
|
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status = of_clk_set_defaults(dev->of_node, false); |
|
if (status < 0) |
|
goto err_clear_wakeup_irq; |
|
|
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status = dev_pm_domain_attach(&client->dev, true); |
|
if (status) |
|
goto err_clear_wakeup_irq; |
|
|
|
/* |
|
* When there are no more users of probe(), |
|
* rename probe_new to probe. |
|
*/ |
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if (driver->probe_new) |
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status = driver->probe_new(client); |
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else if (driver->probe) |
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status = driver->probe(client, |
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i2c_match_id(driver->id_table, client)); |
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else |
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status = -EINVAL; |
|
|
|
if (status) |
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goto err_detach_pm_domain; |
|
|
|
return 0; |
|
|
|
err_detach_pm_domain: |
|
dev_pm_domain_detach(&client->dev, true); |
|
err_clear_wakeup_irq: |
|
dev_pm_clear_wake_irq(&client->dev); |
|
device_init_wakeup(&client->dev, false); |
|
put_sync_adapter: |
|
if (client->flags & I2C_CLIENT_HOST_NOTIFY) |
|
pm_runtime_put_sync(&client->adapter->dev); |
|
|
|
return status; |
|
} |
|
|
|
static int i2c_device_remove(struct device *dev) |
|
{ |
|
struct i2c_client *client = to_i2c_client(dev); |
|
struct i2c_driver *driver; |
|
|
|
driver = to_i2c_driver(dev->driver); |
|
if (driver->remove) { |
|
int status; |
|
|
|
dev_dbg(dev, "remove\n"); |
|
|
|
status = driver->remove(client); |
|
if (status) |
|
dev_warn(dev, "remove failed (%pe), will be ignored\n", ERR_PTR(status)); |
|
} |
|
|
|
dev_pm_domain_detach(&client->dev, true); |
|
|
|
dev_pm_clear_wake_irq(&client->dev); |
|
device_init_wakeup(&client->dev, false); |
|
|
|
client->irq = 0; |
|
if (client->flags & I2C_CLIENT_HOST_NOTIFY) |
|
pm_runtime_put(&client->adapter->dev); |
|
|
|
/* return always 0 because there is WIP to make remove-functions void */ |
|
return 0; |
|
} |
|
|
|
static void i2c_device_shutdown(struct device *dev) |
|
{ |
|
struct i2c_client *client = i2c_verify_client(dev); |
|
struct i2c_driver *driver; |
|
|
|
if (!client || !dev->driver) |
|
return; |
|
driver = to_i2c_driver(dev->driver); |
|
if (driver->shutdown) |
|
driver->shutdown(client); |
|
} |
|
|
|
static void i2c_client_dev_release(struct device *dev) |
|
{ |
|
kfree(to_i2c_client(dev)); |
|
} |
|
|
|
static ssize_t |
|
name_show(struct device *dev, struct device_attribute *attr, char *buf) |
|
{ |
|
return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
|
to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); |
|
} |
|
static DEVICE_ATTR_RO(name); |
|
|
|
static ssize_t |
|
modalias_show(struct device *dev, struct device_attribute *attr, char *buf) |
|
{ |
|
struct i2c_client *client = to_i2c_client(dev); |
|
int len; |
|
|
|
len = of_device_modalias(dev, buf, PAGE_SIZE); |
|
if (len != -ENODEV) |
|
return len; |
|
|
|
len = acpi_device_modalias(dev, buf, PAGE_SIZE -1); |
|
if (len != -ENODEV) |
|
return len; |
|
|
|
return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
|
} |
|
static DEVICE_ATTR_RO(modalias); |
|
|
|
static struct attribute *i2c_dev_attrs[] = { |
|
&dev_attr_name.attr, |
|
/* modalias helps coldplug: modprobe $(cat .../modalias) */ |
|
&dev_attr_modalias.attr, |
|
NULL |
|
}; |
|
ATTRIBUTE_GROUPS(i2c_dev); |
|
|
|
struct bus_type i2c_bus_type = { |
|
.name = "i2c", |
|
.match = i2c_device_match, |
|
.probe = i2c_device_probe, |
|
.remove = i2c_device_remove, |
|
.shutdown = i2c_device_shutdown, |
|
}; |
|
EXPORT_SYMBOL_GPL(i2c_bus_type); |
|
|
|
struct device_type i2c_client_type = { |
|
.groups = i2c_dev_groups, |
|
.uevent = i2c_device_uevent, |
|
.release = i2c_client_dev_release, |
|
}; |
|
EXPORT_SYMBOL_GPL(i2c_client_type); |
|
|
|
|
|
/** |
|
* i2c_verify_client - return parameter as i2c_client, or NULL |
|
* @dev: device, probably from some driver model iterator |
|
* |
|
* When traversing the driver model tree, perhaps using driver model |
|
* iterators like @device_for_each_child(), you can't assume very much |
|
* about the nodes you find. Use this function to avoid oopses caused |
|
* by wrongly treating some non-I2C device as an i2c_client. |
|
*/ |
|
struct i2c_client *i2c_verify_client(struct device *dev) |
|
{ |
|
return (dev->type == &i2c_client_type) |
|
? to_i2c_client(dev) |
|
: NULL; |
|
} |
|
EXPORT_SYMBOL(i2c_verify_client); |
|
|
|
|
|
/* Return a unique address which takes the flags of the client into account */ |
|
static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client) |
|
{ |
|
unsigned short addr = client->addr; |
|
|
|
/* For some client flags, add an arbitrary offset to avoid collisions */ |
|
if (client->flags & I2C_CLIENT_TEN) |
|
addr |= I2C_ADDR_OFFSET_TEN_BIT; |
|
|
|
if (client->flags & I2C_CLIENT_SLAVE) |
|
addr |= I2C_ADDR_OFFSET_SLAVE; |
|
|
|
return addr; |
|
} |
|
|
|
/* This is a permissive address validity check, I2C address map constraints |
|
* are purposely not enforced, except for the general call address. */ |
|
static int i2c_check_addr_validity(unsigned int addr, unsigned short flags) |
|
{ |
|
if (flags & I2C_CLIENT_TEN) { |
|
/* 10-bit address, all values are valid */ |
|
if (addr > 0x3ff) |
|
return -EINVAL; |
|
} else { |
|
/* 7-bit address, reject the general call address */ |
|
if (addr == 0x00 || addr > 0x7f) |
|
return -EINVAL; |
|
} |
|
return 0; |
|
} |
|
|
|
/* And this is a strict address validity check, used when probing. If a |
|
* device uses a reserved address, then it shouldn't be probed. 7-bit |
|
* addressing is assumed, 10-bit address devices are rare and should be |
|
* explicitly enumerated. */ |
|
int i2c_check_7bit_addr_validity_strict(unsigned short addr) |
|
{ |
|
/* |
|
* Reserved addresses per I2C specification: |
|
* 0x00 General call address / START byte |
|
* 0x01 CBUS address |
|
* 0x02 Reserved for different bus format |
|
* 0x03 Reserved for future purposes |
|
* 0x04-0x07 Hs-mode master code |
|
* 0x78-0x7b 10-bit slave addressing |
|
* 0x7c-0x7f Reserved for future purposes |
|
*/ |
|
if (addr < 0x08 || addr > 0x77) |
|
return -EINVAL; |
|
return 0; |
|
} |
|
|
|
static int __i2c_check_addr_busy(struct device *dev, void *addrp) |
|
{ |
|
struct i2c_client *client = i2c_verify_client(dev); |
|
int addr = *(int *)addrp; |
|
|
|
if (client && i2c_encode_flags_to_addr(client) == addr) |
|
return -EBUSY; |
|
return 0; |
|
} |
|
|
|
/* walk up mux tree */ |
|
static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) |
|
{ |
|
struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
|
int result; |
|
|
|
result = device_for_each_child(&adapter->dev, &addr, |
|
__i2c_check_addr_busy); |
|
|
|
if (!result && parent) |
|
result = i2c_check_mux_parents(parent, addr); |
|
|
|
return result; |
|
} |
|
|
|
/* recurse down mux tree */ |
|
static int i2c_check_mux_children(struct device *dev, void *addrp) |
|
{ |
|
int result; |
|
|
|
if (dev->type == &i2c_adapter_type) |
|
result = device_for_each_child(dev, addrp, |
|
i2c_check_mux_children); |
|
else |
|
result = __i2c_check_addr_busy(dev, addrp); |
|
|
|
return result; |
|
} |
|
|
|
static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) |
|
{ |
|
struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
|
int result = 0; |
|
|
|
if (parent) |
|
result = i2c_check_mux_parents(parent, addr); |
|
|
|
if (!result) |
|
result = device_for_each_child(&adapter->dev, &addr, |
|
i2c_check_mux_children); |
|
|
|
return result; |
|
} |
|
|
|
/** |
|
* i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment |
|
* @adapter: Target I2C bus segment |
|
* @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT |
|
* locks only this branch in the adapter tree |
|
*/ |
|
static void i2c_adapter_lock_bus(struct i2c_adapter *adapter, |
|
unsigned int flags) |
|
{ |
|
rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter)); |
|
} |
|
|
|
/** |
|
* i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment |
|
* @adapter: Target I2C bus segment |
|
* @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT |
|
* trylocks only this branch in the adapter tree |
|
*/ |
|
static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter, |
|
unsigned int flags) |
|
{ |
|
return rt_mutex_trylock(&adapter->bus_lock); |
|
} |
|
|
|
/** |
|
* i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment |
|
* @adapter: Target I2C bus segment |
|
* @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT |
|
* unlocks only this branch in the adapter tree |
|
*/ |
|
static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter, |
|
unsigned int flags) |
|
{ |
|
rt_mutex_unlock(&adapter->bus_lock); |
|
} |
|
|
|
static void i2c_dev_set_name(struct i2c_adapter *adap, |
|
struct i2c_client *client, |
|
struct i2c_board_info const *info) |
|
{ |
|
struct acpi_device *adev = ACPI_COMPANION(&client->dev); |
|
|
|
if (info && info->dev_name) { |
|
dev_set_name(&client->dev, "i2c-%s", info->dev_name); |
|
return; |
|
} |
|
|
|
if (adev) { |
|
dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); |
|
return; |
|
} |
|
|
|
dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), |
|
i2c_encode_flags_to_addr(client)); |
|
} |
|
|
|
int i2c_dev_irq_from_resources(const struct resource *resources, |
|
unsigned int num_resources) |
|
{ |
|
struct irq_data *irqd; |
|
int i; |
|
|
|
for (i = 0; i < num_resources; i++) { |
|
const struct resource *r = &resources[i]; |
|
|
|
if (resource_type(r) != IORESOURCE_IRQ) |
|
continue; |
|
|
|
if (r->flags & IORESOURCE_BITS) { |
|
irqd = irq_get_irq_data(r->start); |
|
if (!irqd) |
|
break; |
|
|
|
irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); |
|
} |
|
|
|
return r->start; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* i2c_new_client_device - instantiate an i2c device |
|
* @adap: the adapter managing the device |
|
* @info: describes one I2C device; bus_num is ignored |
|
* Context: can sleep |
|
* |
|
* Create an i2c device. Binding is handled through driver model |
|
* probe()/remove() methods. A driver may be bound to this device when we |
|
* return from this function, or any later moment (e.g. maybe hotplugging will |
|
* load the driver module). This call is not appropriate for use by mainboard |
|
* initialization logic, which usually runs during an arch_initcall() long |
|
* before any i2c_adapter could exist. |
|
* |
|
* This returns the new i2c client, which may be saved for later use with |
|
* i2c_unregister_device(); or an ERR_PTR to describe the error. |
|
*/ |
|
struct i2c_client * |
|
i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info) |
|
{ |
|
struct i2c_client *client; |
|
int status; |
|
|
|
client = kzalloc(sizeof *client, GFP_KERNEL); |
|
if (!client) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
client->adapter = adap; |
|
|
|
client->dev.platform_data = info->platform_data; |
|
client->flags = info->flags; |
|
client->addr = info->addr; |
|
|
|
client->init_irq = info->irq; |
|
if (!client->init_irq) |
|
client->init_irq = i2c_dev_irq_from_resources(info->resources, |
|
info->num_resources); |
|
|
|
strlcpy(client->name, info->type, sizeof(client->name)); |
|
|
|
status = i2c_check_addr_validity(client->addr, client->flags); |
|
if (status) { |
|
dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", |
|
client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); |
|
goto out_err_silent; |
|
} |
|
|
|
/* Check for address business */ |
|
status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client)); |
|
if (status) |
|
goto out_err; |
|
|
|
client->dev.parent = &client->adapter->dev; |
|
client->dev.bus = &i2c_bus_type; |
|
client->dev.type = &i2c_client_type; |
|
client->dev.of_node = of_node_get(info->of_node); |
|
client->dev.fwnode = info->fwnode; |
|
|
|
i2c_dev_set_name(adap, client, info); |
|
|
|
if (info->properties) { |
|
status = device_add_properties(&client->dev, info->properties); |
|
if (status) { |
|
dev_err(&adap->dev, |
|
"Failed to add properties to client %s: %d\n", |
|
client->name, status); |
|
goto out_err_put_of_node; |
|
} |
|
} |
|
|
|
status = device_register(&client->dev); |
|
if (status) |
|
goto out_free_props; |
|
|
|
dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
|
client->name, dev_name(&client->dev)); |
|
|
|
return client; |
|
|
|
out_free_props: |
|
if (info->properties) |
|
device_remove_properties(&client->dev); |
|
out_err_put_of_node: |
|
of_node_put(info->of_node); |
|
out_err: |
|
dev_err(&adap->dev, |
|
"Failed to register i2c client %s at 0x%02x (%d)\n", |
|
client->name, client->addr, status); |
|
out_err_silent: |
|
kfree(client); |
|
return ERR_PTR(status); |
|
} |
|
EXPORT_SYMBOL_GPL(i2c_new_client_device); |
|
|
|
/** |
|
* i2c_unregister_device - reverse effect of i2c_new_*_device() |
|
* @client: value returned from i2c_new_*_device() |
|
* Context: can sleep |
|
*/ |
|
void i2c_unregister_device(struct i2c_client *client) |
|
{ |
|
if (IS_ERR_OR_NULL(client)) |
|
return; |
|
|
|
if (client->dev.of_node) { |
|
of_node_clear_flag(client->dev.of_node, OF_POPULATED); |
|
of_node_put(client->dev.of_node); |
|
} |
|
|
|
if (ACPI_COMPANION(&client->dev)) |
|
acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev)); |
|
device_unregister(&client->dev); |
|
} |
|
EXPORT_SYMBOL_GPL(i2c_unregister_device); |
|
|
|
|
|
static const struct i2c_device_id dummy_id[] = { |
|
{ "dummy", 0 }, |
|
{ }, |
|
}; |
|
|
|
static int dummy_probe(struct i2c_client *client, |
|
const struct i2c_device_id *id) |
|
{ |
|
return 0; |
|
} |
|
|
|
static int dummy_remove(struct i2c_client *client) |
|
{ |
|
return 0; |
|
} |
|
|
|
static struct i2c_driver dummy_driver = { |
|
.driver.name = "dummy", |
|
.probe = dummy_probe, |
|
.remove = dummy_remove, |
|
.id_table = dummy_id, |
|
}; |
|
|
|
/** |
|
* i2c_new_dummy_device - return a new i2c device bound to a dummy driver |
|
* @adapter: the adapter managing the device |
|
* @address: seven bit address to be used |
|
* Context: can sleep |
|
* |
|
* This returns an I2C client bound to the "dummy" driver, intended for use |
|
* with devices that consume multiple addresses. Examples of such chips |
|
* include various EEPROMS (like 24c04 and 24c08 models). |
|
* |
|
* These dummy devices have two main uses. First, most I2C and SMBus calls |
|
* except i2c_transfer() need a client handle; the dummy will be that handle. |
|
* And second, this prevents the specified address from being bound to a |
|
* different driver. |
|
* |
|
* This returns the new i2c client, which should be saved for later use with |
|
* i2c_unregister_device(); or an ERR_PTR to describe the error. |
|
*/ |
|
struct i2c_client *i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address) |
|
{ |
|
struct i2c_board_info info = { |
|
I2C_BOARD_INFO("dummy", address), |
|
}; |
|
|
|
return i2c_new_client_device(adapter, &info); |
|
} |
|
EXPORT_SYMBOL_GPL(i2c_new_dummy_device); |
|
|
|
struct i2c_dummy_devres { |
|
struct i2c_client *client; |
|
}; |
|
|
|
static void devm_i2c_release_dummy(struct device *dev, void *res) |
|
{ |
|
struct i2c_dummy_devres *this = res; |
|
|
|
i2c_unregister_device(this->client); |
|
} |
|
|
|
/** |
|
* devm_i2c_new_dummy_device - return a new i2c device bound to a dummy driver |
|
* @dev: device the managed resource is bound to |
|
* @adapter: the adapter managing the device |
|
* @address: seven bit address to be used |
|
* Context: can sleep |
|
* |
|
* This is the device-managed version of @i2c_new_dummy_device. It returns the |
|
* new i2c client or an ERR_PTR in case of an error. |
|
*/ |
|
struct i2c_client *devm_i2c_new_dummy_device(struct device *dev, |
|
struct i2c_adapter *adapter, |
|
u16 address) |
|
{ |
|
struct i2c_dummy_devres *dr; |
|
struct i2c_client *client; |
|
|
|
dr = devres_alloc(devm_i2c_release_dummy, sizeof(*dr), GFP_KERNEL); |
|
if (!dr) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
client = i2c_new_dummy_device(adapter, address); |
|
if (IS_ERR(client)) { |
|
devres_free(dr); |
|
} else { |
|
dr->client = client; |
|
devres_add(dev, dr); |
|
} |
|
|
|
return client; |
|
} |
|
EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device); |
|
|
|
/** |
|
* i2c_new_ancillary_device - Helper to get the instantiated secondary address |
|
* and create the associated device |
|
* @client: Handle to the primary client |
|
* @name: Handle to specify which secondary address to get |
|
* @default_addr: Used as a fallback if no secondary address was specified |
|
* Context: can sleep |
|
* |
|
* I2C clients can be composed of multiple I2C slaves bound together in a single |
|
* component. The I2C client driver then binds to the master I2C slave and needs |
|
* to create I2C dummy clients to communicate with all the other slaves. |
|
* |
|
* This function creates and returns an I2C dummy client whose I2C address is |
|
* retrieved from the platform firmware based on the given slave name. If no |
|
* address is specified by the firmware default_addr is used. |
|
* |
|
* On DT-based platforms the address is retrieved from the "reg" property entry |
|
* cell whose "reg-names" value matches the slave name. |
|
* |
|
* This returns the new i2c client, which should be saved for later use with |
|
* i2c_unregister_device(); or an ERR_PTR to describe the error. |
|
*/ |
|
struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client, |
|
const char *name, |
|
u16 default_addr) |
|
{ |
|
struct device_node *np = client->dev.of_node; |
|
u32 addr = default_addr; |
|
int i; |
|
|
|
if (np) { |
|
i = of_property_match_string(np, "reg-names", name); |
|
if (i >= 0) |
|
of_property_read_u32_index(np, "reg", i, &addr); |
|
} |
|
|
|
dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr); |
|
return i2c_new_dummy_device(client->adapter, addr); |
|
} |
|
EXPORT_SYMBOL_GPL(i2c_new_ancillary_device); |
|
|
|
/* ------------------------------------------------------------------------- */ |
|
|
|
/* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
|
|
|
static void i2c_adapter_dev_release(struct device *dev) |
|
{ |
|
struct i2c_adapter *adap = to_i2c_adapter(dev); |
|
complete(&adap->dev_released); |
|
} |
|
|
|
unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) |
|
{ |
|
unsigned int depth = 0; |
|
|
|
while ((adapter = i2c_parent_is_i2c_adapter(adapter))) |
|
depth++; |
|
|
|
WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES, |
|
"adapter depth exceeds lockdep subclass limit\n"); |
|
|
|
return depth; |
|
} |
|
EXPORT_SYMBOL_GPL(i2c_adapter_depth); |
|
|
|
/* |
|
* Let users instantiate I2C devices through sysfs. This can be used when |
|
* platform initialization code doesn't contain the proper data for |
|
* whatever reason. Also useful for drivers that do device detection and |
|
* detection fails, either because the device uses an unexpected address, |
|
* or this is a compatible device with different ID register values. |
|
* |
|
* Parameter checking may look overzealous, but we really don't want |
|
* the user to provide incorrect parameters. |
|
*/ |
|
static ssize_t |
|
new_device_store(struct device *dev, struct device_attribute *attr, |
|
const char *buf, size_t count) |
|
{ |
|
struct i2c_adapter *adap = to_i2c_adapter(dev); |
|
struct i2c_board_info info; |
|
struct i2c_client *client; |
|
char *blank, end; |
|
int res; |
|
|
|
memset(&info, 0, sizeof(struct i2c_board_info)); |
|
|
|
blank = strchr(buf, ' '); |
|
if (!blank) { |
|
dev_err(dev, "%s: Missing parameters\n", "new_device"); |
|
return -EINVAL; |
|
} |
|
if (blank - buf > I2C_NAME_SIZE - 1) { |
|
dev_err(dev, "%s: Invalid device name\n", "new_device"); |
|
return -EINVAL; |
|
} |
|
memcpy(info.type, buf, blank - buf); |
|
|
|
/* Parse remaining parameters, reject extra parameters */ |
|
res = sscanf(++blank, "%hi%c", &info.addr, &end); |
|
if (res < 1) { |
|
dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); |
|
return -EINVAL; |
|
} |
|
if (res > 1 && end != '\n') { |
|
dev_err(dev, "%s: Extra parameters\n", "new_device"); |
|
return -EINVAL; |
|
} |
|
|
|
if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) { |
|
info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT; |
|
info.flags |= I2C_CLIENT_TEN; |
|
} |
|
|
|
if (info.addr & I2C_ADDR_OFFSET_SLAVE) { |
|
info.addr &= ~I2C_ADDR_OFFSET_SLAVE; |
|
info.flags |= I2C_CLIENT_SLAVE; |
|
} |
|
|
|
client = i2c_new_client_device(adap, &info); |
|
if (IS_ERR(client)) |
|
return PTR_ERR(client); |
|
|
|
/* Keep track of the added device */ |
|
mutex_lock(&adap->userspace_clients_lock); |
|
list_add_tail(&client->detected, &adap->userspace_clients); |
|
mutex_unlock(&adap->userspace_clients_lock); |
|
dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
|
info.type, info.addr); |
|
|
|
return count; |
|
} |
|
static DEVICE_ATTR_WO(new_device); |
|
|
|
/* |
|
* And of course let the users delete the devices they instantiated, if |
|
* they got it wrong. This interface can only be used to delete devices |
|
* instantiated by i2c_sysfs_new_device above. This guarantees that we |
|
* don't delete devices to which some kernel code still has references. |
|
* |
|
* Parameter checking may look overzealous, but we really don't want |
|
* the user to delete the wrong device. |
|
*/ |
|
static ssize_t |
|
delete_device_store(struct device *dev, struct device_attribute *attr, |
|
const char *buf, size_t count) |
|
{ |
|
struct i2c_adapter *adap = to_i2c_adapter(dev); |
|
struct i2c_client *client, *next; |
|
unsigned short addr; |
|
char end; |
|
int res; |
|
|
|
/* Parse parameters, reject extra parameters */ |
|
res = sscanf(buf, "%hi%c", &addr, &end); |
|
if (res < 1) { |
|
dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); |
|
return -EINVAL; |
|
} |
|
if (res > 1 && end != '\n') { |
|
dev_err(dev, "%s: Extra parameters\n", "delete_device"); |
|
return -EINVAL; |
|
} |
|
|
|
/* Make sure the device was added through sysfs */ |
|
res = -ENOENT; |
|
mutex_lock_nested(&adap->userspace_clients_lock, |
|
i2c_adapter_depth(adap)); |
|
list_for_each_entry_safe(client, next, &adap->userspace_clients, |
|
detected) { |
|
if (i2c_encode_flags_to_addr(client) == addr) { |
|
dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
|
"delete_device", client->name, client->addr); |
|
|
|
list_del(&client->detected); |
|
i2c_unregister_device(client); |
|
res = count; |
|
break; |
|
} |
|
} |
|
mutex_unlock(&adap->userspace_clients_lock); |
|
|
|
if (res < 0) |
|
dev_err(dev, "%s: Can't find device in list\n", |
|
"delete_device"); |
|
return res; |
|
} |
|
static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, |
|
delete_device_store); |
|
|
|
static struct attribute *i2c_adapter_attrs[] = { |
|
&dev_attr_name.attr, |
|
&dev_attr_new_device.attr, |
|
&dev_attr_delete_device.attr, |
|
NULL |
|
}; |
|
ATTRIBUTE_GROUPS(i2c_adapter); |
|
|
|
struct device_type i2c_adapter_type = { |
|
.groups = i2c_adapter_groups, |
|
.release = i2c_adapter_dev_release, |
|
}; |
|
EXPORT_SYMBOL_GPL(i2c_adapter_type); |
|
|
|
/** |
|
* i2c_verify_adapter - return parameter as i2c_adapter or NULL |
|
* @dev: device, probably from some driver model iterator |
|
* |
|
* When traversing the driver model tree, perhaps using driver model |
|
* iterators like @device_for_each_child(), you can't assume very much |
|
* about the nodes you find. Use this function to avoid oopses caused |
|
* by wrongly treating some non-I2C device as an i2c_adapter. |
|
*/ |
|
struct i2c_adapter *i2c_verify_adapter(struct device *dev) |
|
{ |
|
return (dev->type == &i2c_adapter_type) |
|
? to_i2c_adapter(dev) |
|
: NULL; |
|
} |
|
EXPORT_SYMBOL(i2c_verify_adapter); |
|
|
|
#ifdef CONFIG_I2C_COMPAT |
|
static struct class_compat *i2c_adapter_compat_class; |
|
#endif |
|
|
|
static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
|
{ |
|
struct i2c_devinfo *devinfo; |
|
|
|
down_read(&__i2c_board_lock); |
|
list_for_each_entry(devinfo, &__i2c_board_list, list) { |
|
if (devinfo->busnum == adapter->nr && |
|
IS_ERR(i2c_new_client_device(adapter, &devinfo->board_info))) |
|
dev_err(&adapter->dev, |
|
"Can't create device at 0x%02x\n", |
|
devinfo->board_info.addr); |
|
} |
|
up_read(&__i2c_board_lock); |
|
} |
|
|
|
static int i2c_do_add_adapter(struct i2c_driver *driver, |
|
struct i2c_adapter *adap) |
|
{ |
|
/* Detect supported devices on that bus, and instantiate them */ |
|
i2c_detect(adap, driver); |
|
|
|
return 0; |
|
} |
|
|
|
static int __process_new_adapter(struct device_driver *d, void *data) |
|
{ |
|
return i2c_do_add_adapter(to_i2c_driver(d), data); |
|
} |
|
|
|
static const struct i2c_lock_operations i2c_adapter_lock_ops = { |
|
.lock_bus = i2c_adapter_lock_bus, |
|
.trylock_bus = i2c_adapter_trylock_bus, |
|
.unlock_bus = i2c_adapter_unlock_bus, |
|
}; |
|
|
|
static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap) |
|
{ |
|
struct irq_domain *domain = adap->host_notify_domain; |
|
irq_hw_number_t hwirq; |
|
|
|
if (!domain) |
|
return; |
|
|
|
for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++) |
|
irq_dispose_mapping(irq_find_mapping(domain, hwirq)); |
|
|
|
irq_domain_remove(domain); |
|
adap->host_notify_domain = NULL; |
|
} |
|
|
|
static int i2c_host_notify_irq_map(struct irq_domain *h, |
|
unsigned int virq, |
|
irq_hw_number_t hw_irq_num) |
|
{ |
|
irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq); |
|
|
|
return 0; |
|
} |
|
|
|
static const struct irq_domain_ops i2c_host_notify_irq_ops = { |
|
.map = i2c_host_notify_irq_map, |
|
}; |
|
|
|
static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap) |
|
{ |
|
struct irq_domain *domain; |
|
|
|
if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY)) |
|
return 0; |
|
|
|
domain = irq_domain_create_linear(adap->dev.parent->fwnode, |
|
I2C_ADDR_7BITS_COUNT, |
|
&i2c_host_notify_irq_ops, adap); |
|
if (!domain) |
|
return -ENOMEM; |
|
|
|
adap->host_notify_domain = domain; |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct |
|
* I2C client. |
|
* @adap: the adapter |
|
* @addr: the I2C address of the notifying device |
|
* Context: can't sleep |
|
* |
|
* Helper function to be called from an I2C bus driver's interrupt |
|
* handler. It will schedule the Host Notify IRQ. |
|
*/ |
|
int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr) |
|
{ |
|
int irq; |
|
|
|
if (!adap) |
|
return -EINVAL; |
|
|
|
irq = irq_find_mapping(adap->host_notify_domain, addr); |
|
if (irq <= 0) |
|
return -ENXIO; |
|
|
|
generic_handle_irq(irq); |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify); |
|
|
|
static int i2c_register_adapter(struct i2c_adapter *adap) |
|
{ |
|
int res = -EINVAL; |
|
|
|
/* Can't register until after driver model init */ |
|
if (WARN_ON(!is_registered)) { |
|
res = -EAGAIN; |
|
goto out_list; |
|
} |
|
|
|
/* Sanity checks */ |
|
if (WARN(!adap->name[0], "i2c adapter has no name")) |
|
goto out_list; |
|
|
|
if (!adap->algo) { |
|
pr_err("adapter '%s': no algo supplied!\n", adap->name); |
|
goto out_list; |
|
} |
|
|
|
if (!adap->lock_ops) |
|
adap->lock_ops = &i2c_adapter_lock_ops; |
|
|
|
adap->locked_flags = 0; |
|
rt_mutex_init(&adap->bus_lock); |
|
rt_mutex_init(&adap->mux_lock); |
|
mutex_init(&adap->userspace_clients_lock); |
|
INIT_LIST_HEAD(&adap->userspace_clients); |
|
|
|
/* Set default timeout to 1 second if not already set */ |
|
if (adap->timeout == 0) |
|
adap->timeout = HZ; |
|
|
|
/* register soft irqs for Host Notify */ |
|
res = i2c_setup_host_notify_irq_domain(adap); |
|
if (res) { |
|
pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n", |
|
adap->name, res); |
|
goto out_list; |
|
} |
|
|
|
dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
|
adap->dev.bus = &i2c_bus_type; |
|
adap->dev.type = &i2c_adapter_type; |
|
res = device_register(&adap->dev); |
|
if (res) { |
|
pr_err("adapter '%s': can't register device (%d)\n", adap->name, res); |
|
goto out_list; |
|
} |
|
|
|
res = of_i2c_setup_smbus_alert(adap); |
|
if (res) |
|
goto out_reg; |
|
|
|
pm_runtime_no_callbacks(&adap->dev); |
|
pm_suspend_ignore_children(&adap->dev, true); |
|
pm_runtime_enable(&adap->dev); |
|
|
|
res = i2c_init_recovery(adap); |
|
if (res == -EPROBE_DEFER) |
|
goto out_reg; |
|
|
|
dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
|
|
|
#ifdef CONFIG_I2C_COMPAT |
|
res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, |
|
adap->dev.parent); |
|
if (res) |
|
dev_warn(&adap->dev, |
|
"Failed to create compatibility class link\n"); |
|
#endif |
|
|
|
/* create pre-declared device nodes */ |
|
of_i2c_register_devices(adap); |
|
i2c_acpi_install_space_handler(adap); |
|
i2c_acpi_register_devices(adap); |
|
|
|
if (adap->nr < __i2c_first_dynamic_bus_num) |
|
i2c_scan_static_board_info(adap); |
|
|
|
/* Notify drivers */ |
|
mutex_lock(&core_lock); |
|
bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); |
|
mutex_unlock(&core_lock); |
|
|
|
return 0; |
|
|
|
out_reg: |
|
init_completion(&adap->dev_released); |
|
device_unregister(&adap->dev); |
|
wait_for_completion(&adap->dev_released); |
|
out_list: |
|
mutex_lock(&core_lock); |
|
idr_remove(&i2c_adapter_idr, adap->nr); |
|
mutex_unlock(&core_lock); |
|
return res; |
|
} |
|
|
|
/** |
|
* __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 |
|
* @adap: the adapter to register (with adap->nr initialized) |
|
* Context: can sleep |
|
* |
|
* See i2c_add_numbered_adapter() for details. |
|
*/ |
|
static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) |
|
{ |
|
int id; |
|
|
|
mutex_lock(&core_lock); |
|
id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL); |
|
mutex_unlock(&core_lock); |
|
if (WARN(id < 0, "couldn't get idr")) |
|
return id == -ENOSPC ? -EBUSY : id; |
|
|
|
return i2c_register_adapter(adap); |
|
} |
|
|
|
/** |
|
* i2c_add_adapter - declare i2c adapter, use dynamic bus number |
|
* @adapter: the adapter to add |
|
* Context: can sleep |
|
* |
|
* This routine is used to declare an I2C adapter when its bus number |
|
* doesn't matter or when its bus number is specified by an dt alias. |
|
* Examples of bases when the bus number doesn't matter: I2C adapters |
|
* dynamically added by USB links or PCI plugin cards. |
|
* |
|
* When this returns zero, a new bus number was allocated and stored |
|
* in adap->nr, and the specified adapter became available for clients. |
|
* Otherwise, a negative errno value is returned. |
|
*/ |
|
int i2c_add_adapter(struct i2c_adapter *adapter) |
|
{ |
|
struct device *dev = &adapter->dev; |
|
int id; |
|
|
|
if (dev->of_node) { |
|
id = of_alias_get_id(dev->of_node, "i2c"); |
|
if (id >= 0) { |
|
adapter->nr = id; |
|
return __i2c_add_numbered_adapter(adapter); |
|
} |
|
} |
|
|
|
mutex_lock(&core_lock); |
|
id = idr_alloc(&i2c_adapter_idr, adapter, |
|
__i2c_first_dynamic_bus_num, 0, GFP_KERNEL); |
|
mutex_unlock(&core_lock); |
|
if (WARN(id < 0, "couldn't get idr")) |
|
return id; |
|
|
|
adapter->nr = id; |
|
|
|
return i2c_register_adapter(adapter); |
|
} |
|
EXPORT_SYMBOL(i2c_add_adapter); |
|
|
|
/** |
|
* i2c_add_numbered_adapter - declare i2c adapter, use static bus number |
|
* @adap: the adapter to register (with adap->nr initialized) |
|
* Context: can sleep |
|
* |
|
* This routine is used to declare an I2C adapter when its bus number |
|
* matters. For example, use it for I2C adapters from system-on-chip CPUs, |
|
* or otherwise built in to the system's mainboard, and where i2c_board_info |
|
* is used to properly configure I2C devices. |
|
* |
|
* If the requested bus number is set to -1, then this function will behave |
|
* identically to i2c_add_adapter, and will dynamically assign a bus number. |
|
* |
|
* If no devices have pre-been declared for this bus, then be sure to |
|
* register the adapter before any dynamically allocated ones. Otherwise |
|
* the required bus ID may not be available. |
|
* |
|
* When this returns zero, the specified adapter became available for |
|
* clients using the bus number provided in adap->nr. Also, the table |
|
* of I2C devices pre-declared using i2c_register_board_info() is scanned, |
|
* and the appropriate driver model device nodes are created. Otherwise, a |
|
* negative errno value is returned. |
|
*/ |
|
int i2c_add_numbered_adapter(struct i2c_adapter *adap) |
|
{ |
|
if (adap->nr == -1) /* -1 means dynamically assign bus id */ |
|
return i2c_add_adapter(adap); |
|
|
|
return __i2c_add_numbered_adapter(adap); |
|
} |
|
EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); |
|
|
|
static void i2c_do_del_adapter(struct i2c_driver *driver, |
|
struct i2c_adapter *adapter) |
|
{ |
|
struct i2c_client *client, *_n; |
|
|
|
/* Remove the devices we created ourselves as the result of hardware |
|
* probing (using a driver's detect method) */ |
|
list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
|
if (client->adapter == adapter) { |
|
dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", |
|
client->name, client->addr); |
|
list_del(&client->detected); |
|
i2c_unregister_device(client); |
|
} |
|
} |
|
} |
|
|
|
static int __unregister_client(struct device *dev, void *dummy) |
|
{ |
|
struct i2c_client *client = i2c_verify_client(dev); |
|
if (client && strcmp(client->name, "dummy")) |
|
i2c_unregister_device(client); |
|
return 0; |
|
} |
|
|
|
static int __unregister_dummy(struct device *dev, void *dummy) |
|
{ |
|
struct i2c_client *client = i2c_verify_client(dev); |
|
i2c_unregister_device(client); |
|
return 0; |
|
} |
|
|
|
static int __process_removed_adapter(struct device_driver *d, void *data) |
|
{ |
|
i2c_do_del_adapter(to_i2c_driver(d), data); |
|
return 0; |
|
} |
|
|
|
/** |
|
* i2c_del_adapter - unregister I2C adapter |
|
* @adap: the adapter being unregistered |
|
* Context: can sleep |
|
* |
|
* This unregisters an I2C adapter which was previously registered |
|
* by @i2c_add_adapter or @i2c_add_numbered_adapter. |
|
*/ |
|
void i2c_del_adapter(struct i2c_adapter *adap) |
|
{ |
|
struct i2c_adapter *found; |
|
struct i2c_client *client, *next; |
|
|
|
/* First make sure that this adapter was ever added */ |
|
mutex_lock(&core_lock); |
|
found = idr_find(&i2c_adapter_idr, adap->nr); |
|
mutex_unlock(&core_lock); |
|
if (found != adap) { |
|
pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name); |
|
return; |
|
} |
|
|
|
i2c_acpi_remove_space_handler(adap); |
|
/* Tell drivers about this removal */ |
|
mutex_lock(&core_lock); |
|
bus_for_each_drv(&i2c_bus_type, NULL, adap, |
|
__process_removed_adapter); |
|
mutex_unlock(&core_lock); |
|
|
|
/* Remove devices instantiated from sysfs */ |
|
mutex_lock_nested(&adap->userspace_clients_lock, |
|
i2c_adapter_depth(adap)); |
|
list_for_each_entry_safe(client, next, &adap->userspace_clients, |
|
detected) { |
|
dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, |
|
client->addr); |
|
list_del(&client->detected); |
|
i2c_unregister_device(client); |
|
} |
|
mutex_unlock(&adap->userspace_clients_lock); |
|
|
|
/* Detach any active clients. This can't fail, thus we do not |
|
* check the returned value. This is a two-pass process, because |
|
* we can't remove the dummy devices during the first pass: they |
|
* could have been instantiated by real devices wishing to clean |
|
* them up properly, so we give them a chance to do that first. */ |
|
device_for_each_child(&adap->dev, NULL, __unregister_client); |
|
device_for_each_child(&adap->dev, NULL, __unregister_dummy); |
|
|
|
#ifdef CONFIG_I2C_COMPAT |
|
class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, |
|
adap->dev.parent); |
|
#endif |
|
|
|
/* device name is gone after device_unregister */ |
|
dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); |
|
|
|
pm_runtime_disable(&adap->dev); |
|
|
|
i2c_host_notify_irq_teardown(adap); |
|
|
|
/* wait until all references to the device are gone |
|
* |
|
* FIXME: This is old code and should ideally be replaced by an |
|
* alternative which results in decoupling the lifetime of the struct |
|
* device from the i2c_adapter, like spi or netdev do. Any solution |
|
* should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled! |
|
*/ |
|
init_completion(&adap->dev_released); |
|
device_unregister(&adap->dev); |
|
wait_for_completion(&adap->dev_released); |
|
|
|
/* free bus id */ |
|
mutex_lock(&core_lock); |
|
idr_remove(&i2c_adapter_idr, adap->nr); |
|
mutex_unlock(&core_lock); |
|
|
|
/* Clear the device structure in case this adapter is ever going to be |
|
added again */ |
|
memset(&adap->dev, 0, sizeof(adap->dev)); |
|
} |
|
EXPORT_SYMBOL(i2c_del_adapter); |
|
|
|
static void i2c_parse_timing(struct device *dev, char *prop_name, u32 *cur_val_p, |
|
u32 def_val, bool use_def) |
|
{ |
|
int ret; |
|
|
|
ret = device_property_read_u32(dev, prop_name, cur_val_p); |
|
if (ret && use_def) |
|
*cur_val_p = def_val; |
|
|
|
dev_dbg(dev, "%s: %u\n", prop_name, *cur_val_p); |
|
} |
|
|
|
/** |
|
* i2c_parse_fw_timings - get I2C related timing parameters from firmware |
|
* @dev: The device to scan for I2C timing properties |
|
* @t: the i2c_timings struct to be filled with values |
|
* @use_defaults: bool to use sane defaults derived from the I2C specification |
|
* when properties are not found, otherwise don't update |
|
* |
|
* Scan the device for the generic I2C properties describing timing parameters |
|
* for the signal and fill the given struct with the results. If a property was |
|
* not found and use_defaults was true, then maximum timings are assumed which |
|
* are derived from the I2C specification. If use_defaults is not used, the |
|
* results will be as before, so drivers can apply their own defaults before |
|
* calling this helper. The latter is mainly intended for avoiding regressions |
|
* of existing drivers which want to switch to this function. New drivers |
|
* almost always should use the defaults. |
|
*/ |
|
void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults) |
|
{ |
|
bool u = use_defaults; |
|
u32 d; |
|
|
|
i2c_parse_timing(dev, "clock-frequency", &t->bus_freq_hz, |
|
I2C_MAX_STANDARD_MODE_FREQ, u); |
|
|
|
d = t->bus_freq_hz <= I2C_MAX_STANDARD_MODE_FREQ ? 1000 : |
|
t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120; |
|
i2c_parse_timing(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns, d, u); |
|
|
|
d = t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120; |
|
i2c_parse_timing(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns, d, u); |
|
|
|
i2c_parse_timing(dev, "i2c-scl-internal-delay-ns", |
|
&t->scl_int_delay_ns, 0, u); |
|
i2c_parse_timing(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns, |
|
t->scl_fall_ns, u); |
|
i2c_parse_timing(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns, 0, u); |
|
i2c_parse_timing(dev, "i2c-digital-filter-width-ns", |
|
&t->digital_filter_width_ns, 0, u); |
|
i2c_parse_timing(dev, "i2c-analog-filter-cutoff-frequency", |
|
&t->analog_filter_cutoff_freq_hz, 0, u); |
|
} |
|
EXPORT_SYMBOL_GPL(i2c_parse_fw_timings); |
|
|
|
/* ------------------------------------------------------------------------- */ |
|
|
|
int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data)) |
|
{ |
|
int res; |
|
|
|
mutex_lock(&core_lock); |
|
res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); |
|
mutex_unlock(&core_lock); |
|
|
|
return res; |
|
} |
|
EXPORT_SYMBOL_GPL(i2c_for_each_dev); |
|
|
|
static int __process_new_driver(struct device *dev, void *data) |
|
{ |
|
if (dev->type != &i2c_adapter_type) |
|
return 0; |
|
return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
|
} |
|
|
|
/* |
|
* An i2c_driver is used with one or more i2c_client (device) nodes to access |
|
* i2c slave chips, on a bus instance associated with some i2c_adapter. |
|
*/ |
|
|
|
int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
|
{ |
|
int res; |
|
|
|
/* Can't register until after driver model init */ |
|
if (WARN_ON(!is_registered)) |
|
return -EAGAIN; |
|
|
|
/* add the driver to the list of i2c drivers in the driver core */ |
|
driver->driver.owner = owner; |
|
driver->driver.bus = &i2c_bus_type; |
|
INIT_LIST_HEAD(&driver->clients); |
|
|
|
/* When registration returns, the driver core |
|
* will have called probe() for all matching-but-unbound devices. |
|
*/ |
|
res = driver_register(&driver->driver); |
|
if (res) |
|
return res; |
|
|
|
pr_debug("driver [%s] registered\n", driver->driver.name); |
|
|
|
/* Walk the adapters that are already present */ |
|
i2c_for_each_dev(driver, __process_new_driver); |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL(i2c_register_driver); |
|
|
|
static int __process_removed_driver(struct device *dev, void *data) |
|
{ |
|
if (dev->type == &i2c_adapter_type) |
|
i2c_do_del_adapter(data, to_i2c_adapter(dev)); |
|
return 0; |
|
} |
|
|
|
/** |
|
* i2c_del_driver - unregister I2C driver |
|
* @driver: the driver being unregistered |
|
* Context: can sleep |
|
*/ |
|
void i2c_del_driver(struct i2c_driver *driver) |
|
{ |
|
i2c_for_each_dev(driver, __process_removed_driver); |
|
|
|
driver_unregister(&driver->driver); |
|
pr_debug("driver [%s] unregistered\n", driver->driver.name); |
|
} |
|
EXPORT_SYMBOL(i2c_del_driver); |
|
|
|
/* ------------------------------------------------------------------------- */ |
|
|
|
struct i2c_cmd_arg { |
|
unsigned cmd; |
|
void *arg; |
|
}; |
|
|
|
static int i2c_cmd(struct device *dev, void *_arg) |
|
{ |
|
struct i2c_client *client = i2c_verify_client(dev); |
|
struct i2c_cmd_arg *arg = _arg; |
|
struct i2c_driver *driver; |
|
|
|
if (!client || !client->dev.driver) |
|
return 0; |
|
|
|
driver = to_i2c_driver(client->dev.driver); |
|
if (driver->command) |
|
driver->command(client, arg->cmd, arg->arg); |
|
return 0; |
|
} |
|
|
|
void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
|
{ |
|
struct i2c_cmd_arg cmd_arg; |
|
|
|
cmd_arg.cmd = cmd; |
|
cmd_arg.arg = arg; |
|
device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); |
|
} |
|
EXPORT_SYMBOL(i2c_clients_command); |
|
|
|
static int __init i2c_init(void) |
|
{ |
|
int retval; |
|
|
|
retval = of_alias_get_highest_id("i2c"); |
|
|
|
down_write(&__i2c_board_lock); |
|
if (retval >= __i2c_first_dynamic_bus_num) |
|
__i2c_first_dynamic_bus_num = retval + 1; |
|
up_write(&__i2c_board_lock); |
|
|
|
retval = bus_register(&i2c_bus_type); |
|
if (retval) |
|
return retval; |
|
|
|
is_registered = true; |
|
|
|
#ifdef CONFIG_I2C_COMPAT |
|
i2c_adapter_compat_class = class_compat_register("i2c-adapter"); |
|
if (!i2c_adapter_compat_class) { |
|
retval = -ENOMEM; |
|
goto bus_err; |
|
} |
|
#endif |
|
retval = i2c_add_driver(&dummy_driver); |
|
if (retval) |
|
goto class_err; |
|
|
|
if (IS_ENABLED(CONFIG_OF_DYNAMIC)) |
|
WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier)); |
|
if (IS_ENABLED(CONFIG_ACPI)) |
|
WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier)); |
|
|
|
return 0; |
|
|
|
class_err: |
|
#ifdef CONFIG_I2C_COMPAT |
|
class_compat_unregister(i2c_adapter_compat_class); |
|
bus_err: |
|
#endif |
|
is_registered = false; |
|
bus_unregister(&i2c_bus_type); |
|
return retval; |
|
} |
|
|
|
static void __exit i2c_exit(void) |
|
{ |
|
if (IS_ENABLED(CONFIG_ACPI)) |
|
WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier)); |
|
if (IS_ENABLED(CONFIG_OF_DYNAMIC)) |
|
WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier)); |
|
i2c_del_driver(&dummy_driver); |
|
#ifdef CONFIG_I2C_COMPAT |
|
class_compat_unregister(i2c_adapter_compat_class); |
|
#endif |
|
bus_unregister(&i2c_bus_type); |
|
tracepoint_synchronize_unregister(); |
|
} |
|
|
|
/* We must initialize early, because some subsystems register i2c drivers |
|
* in subsys_initcall() code, but are linked (and initialized) before i2c. |
|
*/ |
|
postcore_initcall(i2c_init); |
|
module_exit(i2c_exit); |
|
|
|
/* ---------------------------------------------------- |
|
* the functional interface to the i2c busses. |
|
* ---------------------------------------------------- |
|
*/ |
|
|
|
/* Check if val is exceeding the quirk IFF quirk is non 0 */ |
|
#define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk))) |
|
|
|
static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg) |
|
{ |
|
dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n", |
|
err_msg, msg->addr, msg->len, |
|
msg->flags & I2C_M_RD ? "read" : "write"); |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
|
{ |
|
const struct i2c_adapter_quirks *q = adap->quirks; |
|
int max_num = q->max_num_msgs, i; |
|
bool do_len_check = true; |
|
|
|
if (q->flags & I2C_AQ_COMB) { |
|
max_num = 2; |
|
|
|
/* special checks for combined messages */ |
|
if (num == 2) { |
|
if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD) |
|
return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write"); |
|
|
|
if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD)) |
|
return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read"); |
|
|
|
if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr) |
|
return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr"); |
|
|
|
if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len)) |
|
return i2c_quirk_error(adap, &msgs[0], "msg too long"); |
|
|
|
if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len)) |
|
return i2c_quirk_error(adap, &msgs[1], "msg too long"); |
|
|
|
do_len_check = false; |
|
} |
|
} |
|
|
|
if (i2c_quirk_exceeded(num, max_num)) |
|
return i2c_quirk_error(adap, &msgs[0], "too many messages"); |
|
|
|
for (i = 0; i < num; i++) { |
|
u16 len = msgs[i].len; |
|
|
|
if (msgs[i].flags & I2C_M_RD) { |
|
if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len)) |
|
return i2c_quirk_error(adap, &msgs[i], "msg too long"); |
|
|
|
if (q->flags & I2C_AQ_NO_ZERO_LEN_READ && len == 0) |
|
return i2c_quirk_error(adap, &msgs[i], "no zero length"); |
|
} else { |
|
if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len)) |
|
return i2c_quirk_error(adap, &msgs[i], "msg too long"); |
|
|
|
if (q->flags & I2C_AQ_NO_ZERO_LEN_WRITE && len == 0) |
|
return i2c_quirk_error(adap, &msgs[i], "no zero length"); |
|
} |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* __i2c_transfer - unlocked flavor of i2c_transfer |
|
* @adap: Handle to I2C bus |
|
* @msgs: One or more messages to execute before STOP is issued to |
|
* terminate the operation; each message begins with a START. |
|
* @num: Number of messages to be executed. |
|
* |
|
* Returns negative errno, else the number of messages executed. |
|
* |
|
* Adapter lock must be held when calling this function. No debug logging |
|
* takes place. adap->algo->master_xfer existence isn't checked. |
|
*/ |
|
int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
|
{ |
|
unsigned long orig_jiffies; |
|
int ret, try; |
|
|
|
if (WARN_ON(!msgs || num < 1)) |
|
return -EINVAL; |
|
|
|
ret = __i2c_check_suspended(adap); |
|
if (ret) |
|
return ret; |
|
|
|
if (adap->quirks && i2c_check_for_quirks(adap, msgs, num)) |
|
return -EOPNOTSUPP; |
|
|
|
/* |
|
* i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets |
|
* enabled. This is an efficient way of keeping the for-loop from |
|
* being executed when not needed. |
|
*/ |
|
if (static_branch_unlikely(&i2c_trace_msg_key)) { |
|
int i; |
|
for (i = 0; i < num; i++) |
|
if (msgs[i].flags & I2C_M_RD) |
|
trace_i2c_read(adap, &msgs[i], i); |
|
else |
|
trace_i2c_write(adap, &msgs[i], i); |
|
} |
|
|
|
/* Retry automatically on arbitration loss */ |
|
orig_jiffies = jiffies; |
|
for (ret = 0, try = 0; try <= adap->retries; try++) { |
|
if (i2c_in_atomic_xfer_mode() && adap->algo->master_xfer_atomic) |
|
ret = adap->algo->master_xfer_atomic(adap, msgs, num); |
|
else |
|
ret = adap->algo->master_xfer(adap, msgs, num); |
|
|
|
if (ret != -EAGAIN) |
|
break; |
|
if (time_after(jiffies, orig_jiffies + adap->timeout)) |
|
break; |
|
} |
|
|
|
if (static_branch_unlikely(&i2c_trace_msg_key)) { |
|
int i; |
|
for (i = 0; i < ret; i++) |
|
if (msgs[i].flags & I2C_M_RD) |
|
trace_i2c_reply(adap, &msgs[i], i); |
|
trace_i2c_result(adap, num, ret); |
|
} |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL(__i2c_transfer); |
|
|
|
/** |
|
* i2c_transfer - execute a single or combined I2C message |
|
* @adap: Handle to I2C bus |
|
* @msgs: One or more messages to execute before STOP is issued to |
|
* terminate the operation; each message begins with a START. |
|
* @num: Number of messages to be executed. |
|
* |
|
* Returns negative errno, else the number of messages executed. |
|
* |
|
* Note that there is no requirement that each message be sent to |
|
* the same slave address, although that is the most common model. |
|
*/ |
|
int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
|
{ |
|
int ret; |
|
|
|
if (!adap->algo->master_xfer) { |
|
dev_dbg(&adap->dev, "I2C level transfers not supported\n"); |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
/* REVISIT the fault reporting model here is weak: |
|
* |
|
* - When we get an error after receiving N bytes from a slave, |
|
* there is no way to report "N". |
|
* |
|
* - When we get a NAK after transmitting N bytes to a slave, |
|
* there is no way to report "N" ... or to let the master |
|
* continue executing the rest of this combined message, if |
|
* that's the appropriate response. |
|
* |
|
* - When for example "num" is two and we successfully complete |
|
* the first message but get an error part way through the |
|
* second, it's unclear whether that should be reported as |
|
* one (discarding status on the second message) or errno |
|
* (discarding status on the first one). |
|
*/ |
|
ret = __i2c_lock_bus_helper(adap); |
|
if (ret) |
|
return ret; |
|
|
|
ret = __i2c_transfer(adap, msgs, num); |
|
i2c_unlock_bus(adap, I2C_LOCK_SEGMENT); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL(i2c_transfer); |
|
|
|
/** |
|
* i2c_transfer_buffer_flags - issue a single I2C message transferring data |
|
* to/from a buffer |
|
* @client: Handle to slave device |
|
* @buf: Where the data is stored |
|
* @count: How many bytes to transfer, must be less than 64k since msg.len is u16 |
|
* @flags: The flags to be used for the message, e.g. I2C_M_RD for reads |
|
* |
|
* Returns negative errno, or else the number of bytes transferred. |
|
*/ |
|
int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf, |
|
int count, u16 flags) |
|
{ |
|
int ret; |
|
struct i2c_msg msg = { |
|
.addr = client->addr, |
|
.flags = flags | (client->flags & I2C_M_TEN), |
|
.len = count, |
|
.buf = buf, |
|
}; |
|
|
|
ret = i2c_transfer(client->adapter, &msg, 1); |
|
|
|
/* |
|
* If everything went ok (i.e. 1 msg transferred), return #bytes |
|
* transferred, else error code. |
|
*/ |
|
return (ret == 1) ? count : ret; |
|
} |
|
EXPORT_SYMBOL(i2c_transfer_buffer_flags); |
|
|
|
/** |
|
* i2c_get_device_id - get manufacturer, part id and die revision of a device |
|
* @client: The device to query |
|
* @id: The queried information |
|
* |
|
* Returns negative errno on error, zero on success. |
|
*/ |
|
int i2c_get_device_id(const struct i2c_client *client, |
|
struct i2c_device_identity *id) |
|
{ |
|
struct i2c_adapter *adap = client->adapter; |
|
union i2c_smbus_data raw_id; |
|
int ret; |
|
|
|
if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) |
|
return -EOPNOTSUPP; |
|
|
|
raw_id.block[0] = 3; |
|
ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0, |
|
I2C_SMBUS_READ, client->addr << 1, |
|
I2C_SMBUS_I2C_BLOCK_DATA, &raw_id); |
|
if (ret) |
|
return ret; |
|
|
|
id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4); |
|
id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3); |
|
id->die_revision = raw_id.block[3] & 0x7; |
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(i2c_get_device_id); |
|
|
|
/* ---------------------------------------------------- |
|
* the i2c address scanning function |
|
* Will not work for 10-bit addresses! |
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* ---------------------------------------------------- |
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*/ |
|
|
|
/* |
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* Legacy default probe function, mostly relevant for SMBus. The default |
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* probe method is a quick write, but it is known to corrupt the 24RF08 |
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* EEPROMs due to a state machine bug, and could also irreversibly |
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* write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, |
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* we use a short byte read instead. Also, some bus drivers don't implement |
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* quick write, so we fallback to a byte read in that case too. |
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* On x86, there is another special case for FSC hardware monitoring chips, |
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* which want regular byte reads (address 0x73.) Fortunately, these are the |
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* only known chips using this I2C address on PC hardware. |
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* Returns 1 if probe succeeded, 0 if not. |
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*/ |
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static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) |
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{ |
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int err; |
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union i2c_smbus_data dummy; |
|
|
|
#ifdef CONFIG_X86 |
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if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) |
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&& i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) |
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err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, |
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I2C_SMBUS_BYTE_DATA, &dummy); |
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else |
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#endif |
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if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) |
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&& i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) |
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err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, |
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I2C_SMBUS_QUICK, NULL); |
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else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) |
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err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, |
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I2C_SMBUS_BYTE, &dummy); |
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else { |
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dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", |
|
addr); |
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err = -EOPNOTSUPP; |
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} |
|
|
|
return err >= 0; |
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} |
|
|
|
static int i2c_detect_address(struct i2c_client *temp_client, |
|
struct i2c_driver *driver) |
|
{ |
|
struct i2c_board_info info; |
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struct i2c_adapter *adapter = temp_client->adapter; |
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int addr = temp_client->addr; |
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int err; |
|
|
|
/* Make sure the address is valid */ |
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err = i2c_check_7bit_addr_validity_strict(addr); |
|
if (err) { |
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dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", |
|
addr); |
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return err; |
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} |
|
|
|
/* Skip if already in use (7 bit, no need to encode flags) */ |
|
if (i2c_check_addr_busy(adapter, addr)) |
|
return 0; |
|
|
|
/* Make sure there is something at this address */ |
|
if (!i2c_default_probe(adapter, addr)) |
|
return 0; |
|
|
|
/* Finally call the custom detection function */ |
|
memset(&info, 0, sizeof(struct i2c_board_info)); |
|
info.addr = addr; |
|
err = driver->detect(temp_client, &info); |
|
if (err) { |
|
/* -ENODEV is returned if the detection fails. We catch it |
|
here as this isn't an error. */ |
|
return err == -ENODEV ? 0 : err; |
|
} |
|
|
|
/* Consistency check */ |
|
if (info.type[0] == '\0') { |
|
dev_err(&adapter->dev, |
|
"%s detection function provided no name for 0x%x\n", |
|
driver->driver.name, addr); |
|
} else { |
|
struct i2c_client *client; |
|
|
|
/* Detection succeeded, instantiate the device */ |
|
if (adapter->class & I2C_CLASS_DEPRECATED) |
|
dev_warn(&adapter->dev, |
|
"This adapter will soon drop class based instantiation of devices. " |
|
"Please make sure client 0x%02x gets instantiated by other means. " |
|
"Check 'Documentation/i2c/instantiating-devices.rst' for details.\n", |
|
info.addr); |
|
|
|
dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", |
|
info.type, info.addr); |
|
client = i2c_new_client_device(adapter, &info); |
|
if (!IS_ERR(client)) |
|
list_add_tail(&client->detected, &driver->clients); |
|
else |
|
dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", |
|
info.type, info.addr); |
|
} |
|
return 0; |
|
} |
|
|
|
static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) |
|
{ |
|
const unsigned short *address_list; |
|
struct i2c_client *temp_client; |
|
int i, err = 0; |
|
|
|
address_list = driver->address_list; |
|
if (!driver->detect || !address_list) |
|
return 0; |
|
|
|
/* Warn that the adapter lost class based instantiation */ |
|
if (adapter->class == I2C_CLASS_DEPRECATED) { |
|
dev_dbg(&adapter->dev, |
|
"This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. " |
|
"If you need it, check 'Documentation/i2c/instantiating-devices.rst' for alternatives.\n", |
|
driver->driver.name); |
|
return 0; |
|
} |
|
|
|
/* Stop here if the classes do not match */ |
|
if (!(adapter->class & driver->class)) |
|
return 0; |
|
|
|
/* Set up a temporary client to help detect callback */ |
|
temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); |
|
if (!temp_client) |
|
return -ENOMEM; |
|
temp_client->adapter = adapter; |
|
|
|
for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
|
dev_dbg(&adapter->dev, |
|
"found normal entry for adapter %d, addr 0x%02x\n", |
|
i2c_adapter_id(adapter), address_list[i]); |
|
temp_client->addr = address_list[i]; |
|
err = i2c_detect_address(temp_client, driver); |
|
if (unlikely(err)) |
|
break; |
|
} |
|
|
|
kfree(temp_client); |
|
return err; |
|
} |
|
|
|
int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) |
|
{ |
|
return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, |
|
I2C_SMBUS_QUICK, NULL) >= 0; |
|
} |
|
EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); |
|
|
|
struct i2c_client * |
|
i2c_new_scanned_device(struct i2c_adapter *adap, |
|
struct i2c_board_info *info, |
|
unsigned short const *addr_list, |
|
int (*probe)(struct i2c_adapter *adap, unsigned short addr)) |
|
{ |
|
int i; |
|
|
|
if (!probe) |
|
probe = i2c_default_probe; |
|
|
|
for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
|
/* Check address validity */ |
|
if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) { |
|
dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n", |
|
addr_list[i]); |
|
continue; |
|
} |
|
|
|
/* Check address availability (7 bit, no need to encode flags) */ |
|
if (i2c_check_addr_busy(adap, addr_list[i])) { |
|
dev_dbg(&adap->dev, |
|
"Address 0x%02x already in use, not probing\n", |
|
addr_list[i]); |
|
continue; |
|
} |
|
|
|
/* Test address responsiveness */ |
|
if (probe(adap, addr_list[i])) |
|
break; |
|
} |
|
|
|
if (addr_list[i] == I2C_CLIENT_END) { |
|
dev_dbg(&adap->dev, "Probing failed, no device found\n"); |
|
return ERR_PTR(-ENODEV); |
|
} |
|
|
|
info->addr = addr_list[i]; |
|
return i2c_new_client_device(adap, info); |
|
} |
|
EXPORT_SYMBOL_GPL(i2c_new_scanned_device); |
|
|
|
struct i2c_adapter *i2c_get_adapter(int nr) |
|
{ |
|
struct i2c_adapter *adapter; |
|
|
|
mutex_lock(&core_lock); |
|
adapter = idr_find(&i2c_adapter_idr, nr); |
|
if (!adapter) |
|
goto exit; |
|
|
|
if (try_module_get(adapter->owner)) |
|
get_device(&adapter->dev); |
|
else |
|
adapter = NULL; |
|
|
|
exit: |
|
mutex_unlock(&core_lock); |
|
return adapter; |
|
} |
|
EXPORT_SYMBOL(i2c_get_adapter); |
|
|
|
void i2c_put_adapter(struct i2c_adapter *adap) |
|
{ |
|
if (!adap) |
|
return; |
|
|
|
put_device(&adap->dev); |
|
module_put(adap->owner); |
|
} |
|
EXPORT_SYMBOL(i2c_put_adapter); |
|
|
|
/** |
|
* i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg |
|
* @msg: the message to be checked |
|
* @threshold: the minimum number of bytes for which using DMA makes sense. |
|
* Should at least be 1. |
|
* |
|
* Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO. |
|
* Or a valid pointer to be used with DMA. After use, release it by |
|
* calling i2c_put_dma_safe_msg_buf(). |
|
* |
|
* This function must only be called from process context! |
|
*/ |
|
u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold) |
|
{ |
|
/* also skip 0-length msgs for bogus thresholds of 0 */ |
|
if (!threshold) |
|
pr_debug("DMA buffer for addr=0x%02x with length 0 is bogus\n", |
|
msg->addr); |
|
if (msg->len < threshold || msg->len == 0) |
|
return NULL; |
|
|
|
if (msg->flags & I2C_M_DMA_SAFE) |
|
return msg->buf; |
|
|
|
pr_debug("using bounce buffer for addr=0x%02x, len=%d\n", |
|
msg->addr, msg->len); |
|
|
|
if (msg->flags & I2C_M_RD) |
|
return kzalloc(msg->len, GFP_KERNEL); |
|
else |
|
return kmemdup(msg->buf, msg->len, GFP_KERNEL); |
|
} |
|
EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf); |
|
|
|
/** |
|
* i2c_put_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg |
|
* @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL. |
|
* @msg: the message which the buffer corresponds to |
|
* @xferred: bool saying if the message was transferred |
|
*/ |
|
void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred) |
|
{ |
|
if (!buf || buf == msg->buf) |
|
return; |
|
|
|
if (xferred && msg->flags & I2C_M_RD) |
|
memcpy(msg->buf, buf, msg->len); |
|
|
|
kfree(buf); |
|
} |
|
EXPORT_SYMBOL_GPL(i2c_put_dma_safe_msg_buf); |
|
|
|
MODULE_AUTHOR("Simon G. Vogl <[email protected]>"); |
|
MODULE_DESCRIPTION("I2C-Bus main module"); |
|
MODULE_LICENSE("GPL");
|
|
|