![Wolfram Sang](/assets/img/avatar_default.png)
All in-tree users have been converted to the new i2c_new_scanned_device function, so remove this deprecated one. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2361 lines
64 KiB
C
2361 lines
64 KiB
C
// 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 <kmalkki@cc.hut.fi>
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* Mux support by Rodolfo Giometti <giometti@enneenne.com> and
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* Michael Lawnick <michael.lawnick.ext@nsn.com>
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*
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* Copyright (C) 2013-2017 Wolfram Sang <wsa@the-dreams.de>
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*/
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#define pr_fmt(fmt) "i2c-core: " fmt
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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/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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#define CREATE_TRACE_POINTS
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#include <trace/events/i2c.h>
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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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#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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* 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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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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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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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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/* 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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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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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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/*
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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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* 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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if (bri->unprepare_recovery)
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bri->unprepare_recovery(adap);
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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_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;
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if (!bri)
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return;
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if (!bri->recover_bus) {
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err_str = "no recover_bus() found";
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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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return;
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}
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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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return;
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err:
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dev_err(&adap->dev, "Not using recovery: %s\n", err_str);
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adap->bus_recovery_info = NULL;
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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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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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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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driver = to_i2c_driver(dev->driver);
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client->irq = client->init_irq;
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if (!client->irq && !driver->disable_i2c_core_irq_mapping) {
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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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return irq;
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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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/*
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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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*/
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if (!driver->id_table &&
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!i2c_acpi_match_device(dev->driver->acpi_match_table, client) &&
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!i2c_of_match_device(dev->driver->of_match_table, client))
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return -ENODEV;
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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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return wakeirq;
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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;
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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);
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if (status < 0)
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goto err_clear_wakeup_irq;
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status = dev_pm_domain_attach(&client->dev, true);
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if (status)
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goto err_clear_wakeup_irq;
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/*
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* When there are no more users of probe(),
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* rename probe_new to probe.
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*/
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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;
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if (status)
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goto err_detach_pm_domain;
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return 0;
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err_detach_pm_domain:
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dev_pm_domain_detach(&client->dev, true);
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err_clear_wakeup_irq:
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dev_pm_clear_wake_irq(&client->dev);
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device_init_wakeup(&client->dev, false);
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return status;
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}
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static int i2c_device_remove(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 = 0;
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if (!client || !dev->driver)
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return 0;
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driver = to_i2c_driver(dev->driver);
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if (driver->remove) {
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dev_dbg(dev, "remove\n");
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status = driver->remove(client);
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}
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dev_pm_domain_detach(&client->dev, true);
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dev_pm_clear_wake_irq(&client->dev);
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device_init_wakeup(&client->dev, false);
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client->irq = 0;
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if (client->flags & I2C_CLIENT_HOST_NOTIFY)
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pm_runtime_put(&client->adapter->dev);
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return status;
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}
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static void i2c_device_shutdown(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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if (!client || !dev->driver)
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return;
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driver = to_i2c_driver(dev->driver);
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if (driver->shutdown)
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driver->shutdown(client);
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}
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static void i2c_client_dev_release(struct device *dev)
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{
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kfree(to_i2c_client(dev));
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}
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static ssize_t
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name_show(struct device *dev, struct device_attribute *attr, char *buf)
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{
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return sprintf(buf, "%s\n", dev->type == &i2c_client_type ?
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to_i2c_client(dev)->name : to_i2c_adapter(dev)->name);
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}
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static DEVICE_ATTR_RO(name);
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static ssize_t
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modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
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{
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struct i2c_client *client = to_i2c_client(dev);
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int len;
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len = of_device_modalias(dev, buf, PAGE_SIZE);
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if (len != -ENODEV)
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return len;
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len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
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if (len != -ENODEV)
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return len;
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return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
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}
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static DEVICE_ATTR_RO(modalias);
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static struct attribute *i2c_dev_attrs[] = {
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&dev_attr_name.attr,
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/* modalias helps coldplug: modprobe $(cat .../modalias) */
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&dev_attr_modalias.attr,
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NULL
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};
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ATTRIBUTE_GROUPS(i2c_dev);
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struct bus_type i2c_bus_type = {
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.name = "i2c",
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.match = i2c_device_match,
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.probe = i2c_device_probe,
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.remove = i2c_device_remove,
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.shutdown = i2c_device_shutdown,
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};
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EXPORT_SYMBOL_GPL(i2c_bus_type);
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struct device_type i2c_client_type = {
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.groups = i2c_dev_groups,
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.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_new_device - instantiate an i2c device
|
|
* @adap: the adapter managing the device
|
|
* @info: describes one I2C device; bus_num is ignored
|
|
* Context: can sleep
|
|
*
|
|
* This deprecated function has the same functionality as
|
|
* @i2c_new_client_device, it just returns NULL instead of an ERR_PTR in case of
|
|
* an error for compatibility with current I2C API. It will be removed once all
|
|
* users are converted.
|
|
*
|
|
* This returns the new i2c client, which may be saved for later use with
|
|
* i2c_unregister_device(); or NULL to indicate an error.
|
|
*/
|
|
struct i2c_client *
|
|
i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
|
|
{
|
|
struct i2c_client *ret;
|
|
|
|
ret = i2c_new_client_device(adap, info);
|
|
return IS_ERR(ret) ? NULL : ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(i2c_new_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.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;
|
|
|
|
dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
|
|
|
|
pm_runtime_no_callbacks(&adap->dev);
|
|
pm_suspend_ignore_children(&adap->dev, true);
|
|
pm_runtime_enable(&adap->dev);
|
|
|
|
#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
|
|
|
|
i2c_init_recovery(adap);
|
|
|
|
/* create pre-declared device nodes */
|
|
of_i2c_register_devices(adap);
|
|
i2c_acpi_register_devices(adap);
|
|
i2c_acpi_install_space_handler(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);
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
int ret;
|
|
|
|
ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz);
|
|
if (ret && use_defaults)
|
|
t->bus_freq_hz = I2C_MAX_STANDARD_MODE_FREQ;
|
|
|
|
ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns);
|
|
if (ret && use_defaults) {
|
|
if (t->bus_freq_hz <= I2C_MAX_STANDARD_MODE_FREQ)
|
|
t->scl_rise_ns = 1000;
|
|
else if (t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ)
|
|
t->scl_rise_ns = 300;
|
|
else
|
|
t->scl_rise_ns = 120;
|
|
}
|
|
|
|
ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns);
|
|
if (ret && use_defaults) {
|
|
if (t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ)
|
|
t->scl_fall_ns = 300;
|
|
else
|
|
t->scl_fall_ns = 120;
|
|
}
|
|
|
|
ret = device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns);
|
|
if (ret && use_defaults)
|
|
t->scl_int_delay_ns = 0;
|
|
|
|
ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns);
|
|
if (ret && use_defaults)
|
|
t->sda_fall_ns = t->scl_fall_ns;
|
|
|
|
ret = device_property_read_u32(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns);
|
|
if (ret && use_defaults)
|
|
t->sda_hold_ns = 0;
|
|
|
|
ret = device_property_read_u32(dev, "i2c-digital-filter-width-ns", &t->digital_filter_width_ns);
|
|
if (ret && use_defaults)
|
|
t->digital_filter_width_ns = 0;
|
|
|
|
ret = device_property_read_u32(dev, "i2c-analog-filter-cutoff-frequency", &t->analog_filter_cutoff_freq_hz);
|
|
if (ret && use_defaults)
|
|
t->analog_filter_cutoff_freq_hz = 0;
|
|
}
|
|
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!
|
|
* ----------------------------------------------------
|
|
*/
|
|
|
|
/*
|
|
* Legacy default probe function, mostly relevant for SMBus. The default
|
|
* probe method is a quick write, but it is known to corrupt the 24RF08
|
|
* EEPROMs due to a state machine bug, and could also irreversibly
|
|
* write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f,
|
|
* we use a short byte read instead. Also, some bus drivers don't implement
|
|
* quick write, so we fallback to a byte read in that case too.
|
|
* On x86, there is another special case for FSC hardware monitoring chips,
|
|
* which want regular byte reads (address 0x73.) Fortunately, these are the
|
|
* only known chips using this I2C address on PC hardware.
|
|
* Returns 1 if probe succeeded, 0 if not.
|
|
*/
|
|
static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr)
|
|
{
|
|
int err;
|
|
union i2c_smbus_data dummy;
|
|
|
|
#ifdef CONFIG_X86
|
|
if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON)
|
|
&& i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA))
|
|
err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
|
|
I2C_SMBUS_BYTE_DATA, &dummy);
|
|
else
|
|
#endif
|
|
if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50)
|
|
&& i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK))
|
|
err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0,
|
|
I2C_SMBUS_QUICK, NULL);
|
|
else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE))
|
|
err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
|
|
I2C_SMBUS_BYTE, &dummy);
|
|
else {
|
|
dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n",
|
|
addr);
|
|
err = -EOPNOTSUPP;
|
|
}
|
|
|
|
return err >= 0;
|
|
}
|
|
|
|
static int i2c_detect_address(struct i2c_client *temp_client,
|
|
struct i2c_driver *driver)
|
|
{
|
|
struct i2c_board_info info;
|
|
struct i2c_adapter *adapter = temp_client->adapter;
|
|
int addr = temp_client->addr;
|
|
int err;
|
|
|
|
/* Make sure the address is valid */
|
|
err = i2c_check_7bit_addr_validity_strict(addr);
|
|
if (err) {
|
|
dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
|
|
addr);
|
|
return err;
|
|
}
|
|
|
|
/* 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;
|
|
int adap_id = i2c_adapter_id(adapter);
|
|
|
|
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",
|
|
adap_id, 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 <simon@tk.uni-linz.ac.at>");
|
|
MODULE_DESCRIPTION("I2C-Bus main module");
|
|
MODULE_LICENSE("GPL");
|