161e3d0f7SWolfram Sang /* 261e3d0f7SWolfram Sang * Linux I2C core 361e3d0f7SWolfram Sang * 461e3d0f7SWolfram Sang * Copyright (C) 1995-99 Simon G. Vogl 561e3d0f7SWolfram Sang * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> 661e3d0f7SWolfram Sang * Mux support by Rodolfo Giometti <giometti@enneenne.com> and 761e3d0f7SWolfram Sang * Michael Lawnick <michael.lawnick.ext@nsn.com> 861e3d0f7SWolfram Sang * 961e3d0f7SWolfram Sang * Copyright (C) 2013-2017 Wolfram Sang <wsa@the-dreams.de> 1061e3d0f7SWolfram Sang * 1161e3d0f7SWolfram Sang * This program is free software; you can redistribute it and/or modify it 1261e3d0f7SWolfram Sang * under the terms of the GNU General Public License as published by the Free 1361e3d0f7SWolfram Sang * Software Foundation; either version 2 of the License, or (at your option) 1461e3d0f7SWolfram Sang * any later version. 1561e3d0f7SWolfram Sang * 1661e3d0f7SWolfram Sang * This program is distributed in the hope that it will be useful, but WITHOUT 1761e3d0f7SWolfram Sang * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 1861e3d0f7SWolfram Sang * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. 1991ed5349SWolfram Sang */ 2091ed5349SWolfram Sang 2191ed5349SWolfram Sang #define pr_fmt(fmt) "i2c-core: " fmt 2291ed5349SWolfram Sang 2391ed5349SWolfram Sang #include <dt-bindings/i2c/i2c.h> 2491ed5349SWolfram Sang #include <linux/acpi.h> 2591ed5349SWolfram Sang #include <linux/clk/clk-conf.h> 2691ed5349SWolfram Sang #include <linux/completion.h> 2791ed5349SWolfram Sang #include <linux/delay.h> 2891ed5349SWolfram Sang #include <linux/err.h> 2991ed5349SWolfram Sang #include <linux/errno.h> 3010c9ef04SPhil Reid #include <linux/gpio/consumer.h> 3191ed5349SWolfram Sang #include <linux/i2c.h> 32f8756c67SPhil Reid #include <linux/i2c-smbus.h> 3391ed5349SWolfram Sang #include <linux/idr.h> 3491ed5349SWolfram Sang #include <linux/init.h> 3591ed5349SWolfram Sang #include <linux/irqflags.h> 3691ed5349SWolfram Sang #include <linux/jump_label.h> 3791ed5349SWolfram Sang #include <linux/kernel.h> 3891ed5349SWolfram Sang #include <linux/module.h> 3991ed5349SWolfram Sang #include <linux/mutex.h> 4091ed5349SWolfram Sang #include <linux/of_device.h> 4191ed5349SWolfram Sang #include <linux/of.h> 4291ed5349SWolfram Sang #include <linux/of_irq.h> 4391ed5349SWolfram Sang #include <linux/pm_domain.h> 4491ed5349SWolfram Sang #include <linux/pm_runtime.h> 4591ed5349SWolfram Sang #include <linux/pm_wakeirq.h> 4691ed5349SWolfram Sang #include <linux/property.h> 4791ed5349SWolfram Sang #include <linux/rwsem.h> 4891ed5349SWolfram Sang #include <linux/slab.h> 4991ed5349SWolfram Sang 5091ed5349SWolfram Sang #include "i2c-core.h" 5191ed5349SWolfram Sang 5291ed5349SWolfram Sang #define CREATE_TRACE_POINTS 5391ed5349SWolfram Sang #include <trace/events/i2c.h> 5491ed5349SWolfram Sang 5591ed5349SWolfram Sang #define I2C_ADDR_OFFSET_TEN_BIT 0xa000 5691ed5349SWolfram Sang #define I2C_ADDR_OFFSET_SLAVE 0x1000 5791ed5349SWolfram Sang 5891ed5349SWolfram Sang #define I2C_ADDR_7BITS_MAX 0x77 5991ed5349SWolfram Sang #define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1) 6091ed5349SWolfram Sang 61dde67eb1SPeter Rosin #define I2C_ADDR_DEVICE_ID 0x7c 62dde67eb1SPeter Rosin 6361e3d0f7SWolfram Sang /* 6461e3d0f7SWolfram Sang * core_lock protects i2c_adapter_idr, and guarantees that device detection, 6561e3d0f7SWolfram Sang * deletion of detected devices, and attach_adapter calls are serialized 6661e3d0f7SWolfram Sang */ 6791ed5349SWolfram Sang static DEFINE_MUTEX(core_lock); 6891ed5349SWolfram Sang static DEFINE_IDR(i2c_adapter_idr); 6991ed5349SWolfram Sang 7091ed5349SWolfram Sang static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); 7191ed5349SWolfram Sang 7291ed5349SWolfram Sang static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE; 7391ed5349SWolfram Sang static bool is_registered; 7491ed5349SWolfram Sang 7591ed5349SWolfram Sang int i2c_transfer_trace_reg(void) 7691ed5349SWolfram Sang { 7791ed5349SWolfram Sang static_key_slow_inc(&i2c_trace_msg); 7891ed5349SWolfram Sang return 0; 7991ed5349SWolfram Sang } 8091ed5349SWolfram Sang 8191ed5349SWolfram Sang void i2c_transfer_trace_unreg(void) 8291ed5349SWolfram Sang { 8391ed5349SWolfram Sang static_key_slow_dec(&i2c_trace_msg); 8491ed5349SWolfram Sang } 8591ed5349SWolfram Sang 8691ed5349SWolfram Sang const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 8791ed5349SWolfram Sang const struct i2c_client *client) 8891ed5349SWolfram Sang { 8991ed5349SWolfram Sang if (!(id && client)) 9091ed5349SWolfram Sang return NULL; 9191ed5349SWolfram Sang 9291ed5349SWolfram Sang while (id->name[0]) { 9391ed5349SWolfram Sang if (strcmp(client->name, id->name) == 0) 9491ed5349SWolfram Sang return id; 9591ed5349SWolfram Sang id++; 9691ed5349SWolfram Sang } 9791ed5349SWolfram Sang return NULL; 9891ed5349SWolfram Sang } 9991ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_match_id); 10091ed5349SWolfram Sang 10191ed5349SWolfram Sang static int i2c_device_match(struct device *dev, struct device_driver *drv) 10291ed5349SWolfram Sang { 10391ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 10491ed5349SWolfram Sang struct i2c_driver *driver; 10591ed5349SWolfram Sang 10691ed5349SWolfram Sang 10791ed5349SWolfram Sang /* Attempt an OF style match */ 10891ed5349SWolfram Sang if (i2c_of_match_device(drv->of_match_table, client)) 10991ed5349SWolfram Sang return 1; 11091ed5349SWolfram Sang 11191ed5349SWolfram Sang /* Then ACPI style match */ 11291ed5349SWolfram Sang if (acpi_driver_match_device(dev, drv)) 11391ed5349SWolfram Sang return 1; 11491ed5349SWolfram Sang 11591ed5349SWolfram Sang driver = to_i2c_driver(drv); 11691ed5349SWolfram Sang 11791ed5349SWolfram Sang /* Finally an I2C match */ 11891ed5349SWolfram Sang if (i2c_match_id(driver->id_table, client)) 11991ed5349SWolfram Sang return 1; 12091ed5349SWolfram Sang 12191ed5349SWolfram Sang return 0; 12291ed5349SWolfram Sang } 12391ed5349SWolfram Sang 12491ed5349SWolfram Sang static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) 12591ed5349SWolfram Sang { 12691ed5349SWolfram Sang struct i2c_client *client = to_i2c_client(dev); 12791ed5349SWolfram Sang int rc; 12891ed5349SWolfram Sang 129af503716SJavier Martinez Canillas rc = of_device_uevent_modalias(dev, env); 130af503716SJavier Martinez Canillas if (rc != -ENODEV) 131af503716SJavier Martinez Canillas return rc; 132af503716SJavier Martinez Canillas 13391ed5349SWolfram Sang rc = acpi_device_uevent_modalias(dev, env); 13491ed5349SWolfram Sang if (rc != -ENODEV) 13591ed5349SWolfram Sang return rc; 13691ed5349SWolfram Sang 13791ed5349SWolfram Sang return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name); 13891ed5349SWolfram Sang } 13991ed5349SWolfram Sang 14091ed5349SWolfram Sang /* i2c bus recovery routines */ 14191ed5349SWolfram Sang static int get_scl_gpio_value(struct i2c_adapter *adap) 14291ed5349SWolfram Sang { 1433991c5c8SPhil Reid return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod); 14491ed5349SWolfram Sang } 14591ed5349SWolfram Sang 14691ed5349SWolfram Sang static void set_scl_gpio_value(struct i2c_adapter *adap, int val) 14791ed5349SWolfram Sang { 1483991c5c8SPhil Reid gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val); 14991ed5349SWolfram Sang } 15091ed5349SWolfram Sang 15191ed5349SWolfram Sang static int get_sda_gpio_value(struct i2c_adapter *adap) 15291ed5349SWolfram Sang { 1533991c5c8SPhil Reid return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod); 15491ed5349SWolfram Sang } 15591ed5349SWolfram Sang 1568092178fSWolfram Sang static void set_sda_gpio_value(struct i2c_adapter *adap, int val) 15791ed5349SWolfram Sang { 1588092178fSWolfram Sang gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val); 15991ed5349SWolfram Sang } 16091ed5349SWolfram Sang 16191ed5349SWolfram Sang /* 16291ed5349SWolfram Sang * We are generating clock pulses. ndelay() determines durating of clk pulses. 16391ed5349SWolfram Sang * We will generate clock with rate 100 KHz and so duration of both clock levels 16491ed5349SWolfram Sang * is: delay in ns = (10^6 / 100) / 2 16591ed5349SWolfram Sang */ 16691ed5349SWolfram Sang #define RECOVERY_NDELAY 5000 16791ed5349SWolfram Sang #define RECOVERY_CLK_CNT 9 16891ed5349SWolfram Sang 169e1eb7d28SPhil Reid int i2c_generic_scl_recovery(struct i2c_adapter *adap) 17091ed5349SWolfram Sang { 17191ed5349SWolfram Sang struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; 17291ed5349SWolfram Sang int i = 0, val = 1, ret = 0; 17391ed5349SWolfram Sang 17491ed5349SWolfram Sang if (bri->prepare_recovery) 17591ed5349SWolfram Sang bri->prepare_recovery(adap); 17691ed5349SWolfram Sang 17791ed5349SWolfram Sang bri->set_scl(adap, val); 17872b08fccSWolfram Sang if (bri->set_sda) 17972b08fccSWolfram Sang bri->set_sda(adap, 1); 18091ed5349SWolfram Sang ndelay(RECOVERY_NDELAY); 18191ed5349SWolfram Sang 18291ed5349SWolfram Sang /* 18391ed5349SWolfram Sang * By this time SCL is high, as we need to give 9 falling-rising edges 18491ed5349SWolfram Sang */ 18591ed5349SWolfram Sang while (i++ < RECOVERY_CLK_CNT * 2) { 18691ed5349SWolfram Sang if (val) { 18791ed5349SWolfram Sang /* SCL shouldn't be low here */ 18891ed5349SWolfram Sang if (!bri->get_scl(adap)) { 18991ed5349SWolfram Sang dev_err(&adap->dev, 19091ed5349SWolfram Sang "SCL is stuck low, exit recovery\n"); 19191ed5349SWolfram Sang ret = -EBUSY; 19291ed5349SWolfram Sang break; 19391ed5349SWolfram Sang } 1941f35b865SClaudio Foellmi /* Break if SDA is high */ 1951f35b865SClaudio Foellmi if (bri->get_sda && bri->get_sda(adap)) 1961f35b865SClaudio Foellmi break; 19791ed5349SWolfram Sang } 19891ed5349SWolfram Sang 19991ed5349SWolfram Sang val = !val; 20091ed5349SWolfram Sang bri->set_scl(adap, val); 20191ed5349SWolfram Sang ndelay(RECOVERY_NDELAY); 20291ed5349SWolfram Sang } 20391ed5349SWolfram Sang 2041f35b865SClaudio Foellmi /* check if recovery actually succeeded */ 2051f35b865SClaudio Foellmi if (bri->get_sda && !bri->get_sda(adap)) 2061f35b865SClaudio Foellmi ret = -EBUSY; 2071f35b865SClaudio Foellmi 2082806e6adSWolfram Sang /* If all went well, send STOP for a sane bus state. */ 2092806e6adSWolfram Sang if (ret == 0 && bri->set_sda) { 2102806e6adSWolfram Sang bri->set_scl(adap, 0); 2112806e6adSWolfram Sang ndelay(RECOVERY_NDELAY / 2); 2122806e6adSWolfram Sang bri->set_sda(adap, 0); 2132806e6adSWolfram Sang ndelay(RECOVERY_NDELAY / 2); 2142806e6adSWolfram Sang bri->set_scl(adap, 1); 2152806e6adSWolfram Sang ndelay(RECOVERY_NDELAY / 2); 2162806e6adSWolfram Sang bri->set_sda(adap, 1); 2172806e6adSWolfram Sang ndelay(RECOVERY_NDELAY / 2); 2182806e6adSWolfram Sang } 2192806e6adSWolfram Sang 22091ed5349SWolfram Sang if (bri->unprepare_recovery) 22191ed5349SWolfram Sang bri->unprepare_recovery(adap); 22291ed5349SWolfram Sang 22391ed5349SWolfram Sang return ret; 22491ed5349SWolfram Sang } 22591ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery); 22691ed5349SWolfram Sang 22791ed5349SWolfram Sang int i2c_recover_bus(struct i2c_adapter *adap) 22891ed5349SWolfram Sang { 22991ed5349SWolfram Sang if (!adap->bus_recovery_info) 23091ed5349SWolfram Sang return -EOPNOTSUPP; 23191ed5349SWolfram Sang 23291ed5349SWolfram Sang dev_dbg(&adap->dev, "Trying i2c bus recovery\n"); 23391ed5349SWolfram Sang return adap->bus_recovery_info->recover_bus(adap); 23491ed5349SWolfram Sang } 23591ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_recover_bus); 23691ed5349SWolfram Sang 23791ed5349SWolfram Sang static void i2c_init_recovery(struct i2c_adapter *adap) 23891ed5349SWolfram Sang { 23991ed5349SWolfram Sang struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; 24091ed5349SWolfram Sang char *err_str; 24191ed5349SWolfram Sang 24291ed5349SWolfram Sang if (!bri) 24391ed5349SWolfram Sang return; 24491ed5349SWolfram Sang 24591ed5349SWolfram Sang if (!bri->recover_bus) { 24691ed5349SWolfram Sang err_str = "no recover_bus() found"; 24791ed5349SWolfram Sang goto err; 24891ed5349SWolfram Sang } 24991ed5349SWolfram Sang 2503991c5c8SPhil Reid if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) { 25191ed5349SWolfram Sang bri->get_scl = get_scl_gpio_value; 25291ed5349SWolfram Sang bri->set_scl = set_scl_gpio_value; 2538092178fSWolfram Sang if (bri->sda_gpiod) { 2543991c5c8SPhil Reid bri->get_sda = get_sda_gpio_value; 2558092178fSWolfram Sang /* FIXME: add proper flag instead of '0' once available */ 2568092178fSWolfram Sang if (gpiod_get_direction(bri->sda_gpiod) == 0) 2578092178fSWolfram Sang bri->set_sda = set_sda_gpio_value; 2588092178fSWolfram Sang } 2593991c5c8SPhil Reid return; 2603991c5c8SPhil Reid } 2613991c5c8SPhil Reid 262e1eb7d28SPhil Reid if (bri->recover_bus == i2c_generic_scl_recovery) { 26391ed5349SWolfram Sang /* Generic SCL recovery */ 26491ed5349SWolfram Sang if (!bri->set_scl || !bri->get_scl) { 26591ed5349SWolfram Sang err_str = "no {get|set}_scl() found"; 26691ed5349SWolfram Sang goto err; 26791ed5349SWolfram Sang } 26891ed5349SWolfram Sang } 26991ed5349SWolfram Sang 27091ed5349SWolfram Sang return; 27191ed5349SWolfram Sang err: 27291ed5349SWolfram Sang dev_err(&adap->dev, "Not using recovery: %s\n", err_str); 27391ed5349SWolfram Sang adap->bus_recovery_info = NULL; 27491ed5349SWolfram Sang } 27591ed5349SWolfram Sang 27691ed5349SWolfram Sang static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client) 27791ed5349SWolfram Sang { 27891ed5349SWolfram Sang struct i2c_adapter *adap = client->adapter; 27991ed5349SWolfram Sang unsigned int irq; 28091ed5349SWolfram Sang 28191ed5349SWolfram Sang if (!adap->host_notify_domain) 28291ed5349SWolfram Sang return -ENXIO; 28391ed5349SWolfram Sang 28491ed5349SWolfram Sang if (client->flags & I2C_CLIENT_TEN) 28591ed5349SWolfram Sang return -EINVAL; 28691ed5349SWolfram Sang 28791ed5349SWolfram Sang irq = irq_find_mapping(adap->host_notify_domain, client->addr); 28891ed5349SWolfram Sang if (!irq) 28991ed5349SWolfram Sang irq = irq_create_mapping(adap->host_notify_domain, 29091ed5349SWolfram Sang client->addr); 29191ed5349SWolfram Sang 29291ed5349SWolfram Sang return irq > 0 ? irq : -ENXIO; 29391ed5349SWolfram Sang } 29491ed5349SWolfram Sang 29591ed5349SWolfram Sang static int i2c_device_probe(struct device *dev) 29691ed5349SWolfram Sang { 29791ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 29891ed5349SWolfram Sang struct i2c_driver *driver; 29991ed5349SWolfram Sang int status; 30091ed5349SWolfram Sang 30191ed5349SWolfram Sang if (!client) 30291ed5349SWolfram Sang return 0; 30391ed5349SWolfram Sang 30491ed5349SWolfram Sang driver = to_i2c_driver(dev->driver); 30591ed5349SWolfram Sang 30691ed5349SWolfram Sang if (!client->irq && !driver->disable_i2c_core_irq_mapping) { 30791ed5349SWolfram Sang int irq = -ENOENT; 30891ed5349SWolfram Sang 30991ed5349SWolfram Sang if (client->flags & I2C_CLIENT_HOST_NOTIFY) { 31091ed5349SWolfram Sang dev_dbg(dev, "Using Host Notify IRQ\n"); 31191ed5349SWolfram Sang irq = i2c_smbus_host_notify_to_irq(client); 31291ed5349SWolfram Sang } else if (dev->of_node) { 31391ed5349SWolfram Sang irq = of_irq_get_byname(dev->of_node, "irq"); 31491ed5349SWolfram Sang if (irq == -EINVAL || irq == -ENODATA) 31591ed5349SWolfram Sang irq = of_irq_get(dev->of_node, 0); 31691ed5349SWolfram Sang } else if (ACPI_COMPANION(dev)) { 31791ed5349SWolfram Sang irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0); 31891ed5349SWolfram Sang } 31991ed5349SWolfram Sang if (irq == -EPROBE_DEFER) 32091ed5349SWolfram Sang return irq; 32191ed5349SWolfram Sang 32291ed5349SWolfram Sang if (irq < 0) 32391ed5349SWolfram Sang irq = 0; 32491ed5349SWolfram Sang 32591ed5349SWolfram Sang client->irq = irq; 32691ed5349SWolfram Sang } 32791ed5349SWolfram Sang 32891ed5349SWolfram Sang /* 329f4b17a14SJavier Martinez Canillas * An I2C ID table is not mandatory, if and only if, a suitable OF 330f4b17a14SJavier Martinez Canillas * or ACPI ID table is supplied for the probing device. 33191ed5349SWolfram Sang */ 33291ed5349SWolfram Sang if (!driver->id_table && 333c64ffff7SAndy Shevchenko !i2c_acpi_match_device(dev->driver->acpi_match_table, client) && 33491ed5349SWolfram Sang !i2c_of_match_device(dev->driver->of_match_table, client)) 33591ed5349SWolfram Sang return -ENODEV; 33691ed5349SWolfram Sang 33791ed5349SWolfram Sang if (client->flags & I2C_CLIENT_WAKE) { 33891ed5349SWolfram Sang int wakeirq = -ENOENT; 33991ed5349SWolfram Sang 34091ed5349SWolfram Sang if (dev->of_node) { 34191ed5349SWolfram Sang wakeirq = of_irq_get_byname(dev->of_node, "wakeup"); 34291ed5349SWolfram Sang if (wakeirq == -EPROBE_DEFER) 34391ed5349SWolfram Sang return wakeirq; 34491ed5349SWolfram Sang } 34591ed5349SWolfram Sang 34691ed5349SWolfram Sang device_init_wakeup(&client->dev, true); 34791ed5349SWolfram Sang 34891ed5349SWolfram Sang if (wakeirq > 0 && wakeirq != client->irq) 34991ed5349SWolfram Sang status = dev_pm_set_dedicated_wake_irq(dev, wakeirq); 35091ed5349SWolfram Sang else if (client->irq > 0) 35191ed5349SWolfram Sang status = dev_pm_set_wake_irq(dev, client->irq); 35291ed5349SWolfram Sang else 35391ed5349SWolfram Sang status = 0; 35491ed5349SWolfram Sang 35591ed5349SWolfram Sang if (status) 35691ed5349SWolfram Sang dev_warn(&client->dev, "failed to set up wakeup irq\n"); 35791ed5349SWolfram Sang } 35891ed5349SWolfram Sang 35991ed5349SWolfram Sang dev_dbg(dev, "probe\n"); 36091ed5349SWolfram Sang 36191ed5349SWolfram Sang status = of_clk_set_defaults(dev->of_node, false); 36291ed5349SWolfram Sang if (status < 0) 36391ed5349SWolfram Sang goto err_clear_wakeup_irq; 36491ed5349SWolfram Sang 36591ed5349SWolfram Sang status = dev_pm_domain_attach(&client->dev, true); 36691ed5349SWolfram Sang if (status == -EPROBE_DEFER) 36791ed5349SWolfram Sang goto err_clear_wakeup_irq; 36891ed5349SWolfram Sang 36991ed5349SWolfram Sang /* 37091ed5349SWolfram Sang * When there are no more users of probe(), 37191ed5349SWolfram Sang * rename probe_new to probe. 37291ed5349SWolfram Sang */ 37391ed5349SWolfram Sang if (driver->probe_new) 37491ed5349SWolfram Sang status = driver->probe_new(client); 37591ed5349SWolfram Sang else if (driver->probe) 37691ed5349SWolfram Sang status = driver->probe(client, 37791ed5349SWolfram Sang i2c_match_id(driver->id_table, client)); 37891ed5349SWolfram Sang else 37991ed5349SWolfram Sang status = -EINVAL; 38091ed5349SWolfram Sang 38191ed5349SWolfram Sang if (status) 38291ed5349SWolfram Sang goto err_detach_pm_domain; 38391ed5349SWolfram Sang 38491ed5349SWolfram Sang return 0; 38591ed5349SWolfram Sang 38691ed5349SWolfram Sang err_detach_pm_domain: 38791ed5349SWolfram Sang dev_pm_domain_detach(&client->dev, true); 38891ed5349SWolfram Sang err_clear_wakeup_irq: 38991ed5349SWolfram Sang dev_pm_clear_wake_irq(&client->dev); 39091ed5349SWolfram Sang device_init_wakeup(&client->dev, false); 39191ed5349SWolfram Sang return status; 39291ed5349SWolfram Sang } 39391ed5349SWolfram Sang 39491ed5349SWolfram Sang static int i2c_device_remove(struct device *dev) 39591ed5349SWolfram Sang { 39691ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 39791ed5349SWolfram Sang struct i2c_driver *driver; 39891ed5349SWolfram Sang int status = 0; 39991ed5349SWolfram Sang 40091ed5349SWolfram Sang if (!client || !dev->driver) 40191ed5349SWolfram Sang return 0; 40291ed5349SWolfram Sang 40391ed5349SWolfram Sang driver = to_i2c_driver(dev->driver); 40491ed5349SWolfram Sang if (driver->remove) { 40591ed5349SWolfram Sang dev_dbg(dev, "remove\n"); 40691ed5349SWolfram Sang status = driver->remove(client); 40791ed5349SWolfram Sang } 40891ed5349SWolfram Sang 40991ed5349SWolfram Sang dev_pm_domain_detach(&client->dev, true); 41091ed5349SWolfram Sang 41191ed5349SWolfram Sang dev_pm_clear_wake_irq(&client->dev); 41291ed5349SWolfram Sang device_init_wakeup(&client->dev, false); 41391ed5349SWolfram Sang 41491ed5349SWolfram Sang return status; 41591ed5349SWolfram Sang } 41691ed5349SWolfram Sang 41791ed5349SWolfram Sang static void i2c_device_shutdown(struct device *dev) 41891ed5349SWolfram Sang { 41991ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 42091ed5349SWolfram Sang struct i2c_driver *driver; 42191ed5349SWolfram Sang 42291ed5349SWolfram Sang if (!client || !dev->driver) 42391ed5349SWolfram Sang return; 42491ed5349SWolfram Sang driver = to_i2c_driver(dev->driver); 42591ed5349SWolfram Sang if (driver->shutdown) 42691ed5349SWolfram Sang driver->shutdown(client); 42791ed5349SWolfram Sang } 42891ed5349SWolfram Sang 42991ed5349SWolfram Sang static void i2c_client_dev_release(struct device *dev) 43091ed5349SWolfram Sang { 43191ed5349SWolfram Sang kfree(to_i2c_client(dev)); 43291ed5349SWolfram Sang } 43391ed5349SWolfram Sang 43491ed5349SWolfram Sang static ssize_t 43591ed5349SWolfram Sang show_name(struct device *dev, struct device_attribute *attr, char *buf) 43691ed5349SWolfram Sang { 43791ed5349SWolfram Sang return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? 43891ed5349SWolfram Sang to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); 43991ed5349SWolfram Sang } 44091ed5349SWolfram Sang static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); 44191ed5349SWolfram Sang 44291ed5349SWolfram Sang static ssize_t 44391ed5349SWolfram Sang show_modalias(struct device *dev, struct device_attribute *attr, char *buf) 44491ed5349SWolfram Sang { 44591ed5349SWolfram Sang struct i2c_client *client = to_i2c_client(dev); 44691ed5349SWolfram Sang int len; 44791ed5349SWolfram Sang 448af503716SJavier Martinez Canillas len = of_device_modalias(dev, buf, PAGE_SIZE); 449af503716SJavier Martinez Canillas if (len != -ENODEV) 450af503716SJavier Martinez Canillas return len; 451af503716SJavier Martinez Canillas 45291ed5349SWolfram Sang len = acpi_device_modalias(dev, buf, PAGE_SIZE -1); 45391ed5349SWolfram Sang if (len != -ENODEV) 45491ed5349SWolfram Sang return len; 45591ed5349SWolfram Sang 45691ed5349SWolfram Sang return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); 45791ed5349SWolfram Sang } 45891ed5349SWolfram Sang static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); 45991ed5349SWolfram Sang 46091ed5349SWolfram Sang static struct attribute *i2c_dev_attrs[] = { 46191ed5349SWolfram Sang &dev_attr_name.attr, 46291ed5349SWolfram Sang /* modalias helps coldplug: modprobe $(cat .../modalias) */ 46391ed5349SWolfram Sang &dev_attr_modalias.attr, 46491ed5349SWolfram Sang NULL 46591ed5349SWolfram Sang }; 46691ed5349SWolfram Sang ATTRIBUTE_GROUPS(i2c_dev); 46791ed5349SWolfram Sang 46891ed5349SWolfram Sang struct bus_type i2c_bus_type = { 46991ed5349SWolfram Sang .name = "i2c", 47091ed5349SWolfram Sang .match = i2c_device_match, 47191ed5349SWolfram Sang .probe = i2c_device_probe, 47291ed5349SWolfram Sang .remove = i2c_device_remove, 47391ed5349SWolfram Sang .shutdown = i2c_device_shutdown, 47491ed5349SWolfram Sang }; 47591ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_bus_type); 47691ed5349SWolfram Sang 47791ed5349SWolfram Sang struct device_type i2c_client_type = { 47891ed5349SWolfram Sang .groups = i2c_dev_groups, 47991ed5349SWolfram Sang .uevent = i2c_device_uevent, 48091ed5349SWolfram Sang .release = i2c_client_dev_release, 48191ed5349SWolfram Sang }; 48291ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_client_type); 48391ed5349SWolfram Sang 48491ed5349SWolfram Sang 48591ed5349SWolfram Sang /** 48691ed5349SWolfram Sang * i2c_verify_client - return parameter as i2c_client, or NULL 48791ed5349SWolfram Sang * @dev: device, probably from some driver model iterator 48891ed5349SWolfram Sang * 48991ed5349SWolfram Sang * When traversing the driver model tree, perhaps using driver model 49091ed5349SWolfram Sang * iterators like @device_for_each_child(), you can't assume very much 49191ed5349SWolfram Sang * about the nodes you find. Use this function to avoid oopses caused 49291ed5349SWolfram Sang * by wrongly treating some non-I2C device as an i2c_client. 49391ed5349SWolfram Sang */ 49491ed5349SWolfram Sang struct i2c_client *i2c_verify_client(struct device *dev) 49591ed5349SWolfram Sang { 49691ed5349SWolfram Sang return (dev->type == &i2c_client_type) 49791ed5349SWolfram Sang ? to_i2c_client(dev) 49891ed5349SWolfram Sang : NULL; 49991ed5349SWolfram Sang } 50091ed5349SWolfram Sang EXPORT_SYMBOL(i2c_verify_client); 50191ed5349SWolfram Sang 50291ed5349SWolfram Sang 50391ed5349SWolfram Sang /* Return a unique address which takes the flags of the client into account */ 50491ed5349SWolfram Sang static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client) 50591ed5349SWolfram Sang { 50691ed5349SWolfram Sang unsigned short addr = client->addr; 50791ed5349SWolfram Sang 50891ed5349SWolfram Sang /* For some client flags, add an arbitrary offset to avoid collisions */ 50991ed5349SWolfram Sang if (client->flags & I2C_CLIENT_TEN) 51091ed5349SWolfram Sang addr |= I2C_ADDR_OFFSET_TEN_BIT; 51191ed5349SWolfram Sang 51291ed5349SWolfram Sang if (client->flags & I2C_CLIENT_SLAVE) 51391ed5349SWolfram Sang addr |= I2C_ADDR_OFFSET_SLAVE; 51491ed5349SWolfram Sang 51591ed5349SWolfram Sang return addr; 51691ed5349SWolfram Sang } 51791ed5349SWolfram Sang 51891ed5349SWolfram Sang /* This is a permissive address validity check, I2C address map constraints 51991ed5349SWolfram Sang * are purposely not enforced, except for the general call address. */ 520398432edSWolfram Sang static int i2c_check_addr_validity(unsigned int addr, unsigned short flags) 52191ed5349SWolfram Sang { 52291ed5349SWolfram Sang if (flags & I2C_CLIENT_TEN) { 52391ed5349SWolfram Sang /* 10-bit address, all values are valid */ 52491ed5349SWolfram Sang if (addr > 0x3ff) 52591ed5349SWolfram Sang return -EINVAL; 52691ed5349SWolfram Sang } else { 52791ed5349SWolfram Sang /* 7-bit address, reject the general call address */ 52891ed5349SWolfram Sang if (addr == 0x00 || addr > 0x7f) 52991ed5349SWolfram Sang return -EINVAL; 53091ed5349SWolfram Sang } 53191ed5349SWolfram Sang return 0; 53291ed5349SWolfram Sang } 53391ed5349SWolfram Sang 53491ed5349SWolfram Sang /* And this is a strict address validity check, used when probing. If a 53591ed5349SWolfram Sang * device uses a reserved address, then it shouldn't be probed. 7-bit 53691ed5349SWolfram Sang * addressing is assumed, 10-bit address devices are rare and should be 53791ed5349SWolfram Sang * explicitly enumerated. */ 538e4991ecdSWolfram Sang int i2c_check_7bit_addr_validity_strict(unsigned short addr) 53991ed5349SWolfram Sang { 54091ed5349SWolfram Sang /* 54191ed5349SWolfram Sang * Reserved addresses per I2C specification: 54291ed5349SWolfram Sang * 0x00 General call address / START byte 54391ed5349SWolfram Sang * 0x01 CBUS address 54491ed5349SWolfram Sang * 0x02 Reserved for different bus format 54591ed5349SWolfram Sang * 0x03 Reserved for future purposes 54691ed5349SWolfram Sang * 0x04-0x07 Hs-mode master code 54791ed5349SWolfram Sang * 0x78-0x7b 10-bit slave addressing 54891ed5349SWolfram Sang * 0x7c-0x7f Reserved for future purposes 54991ed5349SWolfram Sang */ 55091ed5349SWolfram Sang if (addr < 0x08 || addr > 0x77) 55191ed5349SWolfram Sang return -EINVAL; 55291ed5349SWolfram Sang return 0; 55391ed5349SWolfram Sang } 55491ed5349SWolfram Sang 55591ed5349SWolfram Sang static int __i2c_check_addr_busy(struct device *dev, void *addrp) 55691ed5349SWolfram Sang { 55791ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 55891ed5349SWolfram Sang int addr = *(int *)addrp; 55991ed5349SWolfram Sang 56091ed5349SWolfram Sang if (client && i2c_encode_flags_to_addr(client) == addr) 56191ed5349SWolfram Sang return -EBUSY; 56291ed5349SWolfram Sang return 0; 56391ed5349SWolfram Sang } 56491ed5349SWolfram Sang 56591ed5349SWolfram Sang /* walk up mux tree */ 56691ed5349SWolfram Sang static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) 56791ed5349SWolfram Sang { 56891ed5349SWolfram Sang struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); 56991ed5349SWolfram Sang int result; 57091ed5349SWolfram Sang 57191ed5349SWolfram Sang result = device_for_each_child(&adapter->dev, &addr, 57291ed5349SWolfram Sang __i2c_check_addr_busy); 57391ed5349SWolfram Sang 57491ed5349SWolfram Sang if (!result && parent) 57591ed5349SWolfram Sang result = i2c_check_mux_parents(parent, addr); 57691ed5349SWolfram Sang 57791ed5349SWolfram Sang return result; 57891ed5349SWolfram Sang } 57991ed5349SWolfram Sang 58091ed5349SWolfram Sang /* recurse down mux tree */ 58191ed5349SWolfram Sang static int i2c_check_mux_children(struct device *dev, void *addrp) 58291ed5349SWolfram Sang { 58391ed5349SWolfram Sang int result; 58491ed5349SWolfram Sang 58591ed5349SWolfram Sang if (dev->type == &i2c_adapter_type) 58691ed5349SWolfram Sang result = device_for_each_child(dev, addrp, 58791ed5349SWolfram Sang i2c_check_mux_children); 58891ed5349SWolfram Sang else 58991ed5349SWolfram Sang result = __i2c_check_addr_busy(dev, addrp); 59091ed5349SWolfram Sang 59191ed5349SWolfram Sang return result; 59291ed5349SWolfram Sang } 59391ed5349SWolfram Sang 59491ed5349SWolfram Sang static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) 59591ed5349SWolfram Sang { 59691ed5349SWolfram Sang struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); 59791ed5349SWolfram Sang int result = 0; 59891ed5349SWolfram Sang 59991ed5349SWolfram Sang if (parent) 60091ed5349SWolfram Sang result = i2c_check_mux_parents(parent, addr); 60191ed5349SWolfram Sang 60291ed5349SWolfram Sang if (!result) 60391ed5349SWolfram Sang result = device_for_each_child(&adapter->dev, &addr, 60491ed5349SWolfram Sang i2c_check_mux_children); 60591ed5349SWolfram Sang 60691ed5349SWolfram Sang return result; 60791ed5349SWolfram Sang } 60891ed5349SWolfram Sang 60991ed5349SWolfram Sang /** 61091ed5349SWolfram Sang * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment 61191ed5349SWolfram Sang * @adapter: Target I2C bus segment 61291ed5349SWolfram Sang * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 61391ed5349SWolfram Sang * locks only this branch in the adapter tree 61491ed5349SWolfram Sang */ 61591ed5349SWolfram Sang static void i2c_adapter_lock_bus(struct i2c_adapter *adapter, 61691ed5349SWolfram Sang unsigned int flags) 61791ed5349SWolfram Sang { 61891ed5349SWolfram Sang rt_mutex_lock(&adapter->bus_lock); 61991ed5349SWolfram Sang } 62091ed5349SWolfram Sang 62191ed5349SWolfram Sang /** 62291ed5349SWolfram Sang * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment 62391ed5349SWolfram Sang * @adapter: Target I2C bus segment 62491ed5349SWolfram Sang * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT 62591ed5349SWolfram Sang * trylocks only this branch in the adapter tree 62691ed5349SWolfram Sang */ 62791ed5349SWolfram Sang static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter, 62891ed5349SWolfram Sang unsigned int flags) 62991ed5349SWolfram Sang { 63091ed5349SWolfram Sang return rt_mutex_trylock(&adapter->bus_lock); 63191ed5349SWolfram Sang } 63291ed5349SWolfram Sang 63391ed5349SWolfram Sang /** 63491ed5349SWolfram Sang * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment 63591ed5349SWolfram Sang * @adapter: Target I2C bus segment 63691ed5349SWolfram Sang * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 63791ed5349SWolfram Sang * unlocks only this branch in the adapter tree 63891ed5349SWolfram Sang */ 63991ed5349SWolfram Sang static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter, 64091ed5349SWolfram Sang unsigned int flags) 64191ed5349SWolfram Sang { 64291ed5349SWolfram Sang rt_mutex_unlock(&adapter->bus_lock); 64391ed5349SWolfram Sang } 64491ed5349SWolfram Sang 64591ed5349SWolfram Sang static void i2c_dev_set_name(struct i2c_adapter *adap, 646728fe6ceSHans de Goede struct i2c_client *client, 647728fe6ceSHans de Goede struct i2c_board_info const *info) 64891ed5349SWolfram Sang { 64991ed5349SWolfram Sang struct acpi_device *adev = ACPI_COMPANION(&client->dev); 65091ed5349SWolfram Sang 651728fe6ceSHans de Goede if (info && info->dev_name) { 652728fe6ceSHans de Goede dev_set_name(&client->dev, "i2c-%s", info->dev_name); 653728fe6ceSHans de Goede return; 654728fe6ceSHans de Goede } 655728fe6ceSHans de Goede 65691ed5349SWolfram Sang if (adev) { 65791ed5349SWolfram Sang dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); 65891ed5349SWolfram Sang return; 65991ed5349SWolfram Sang } 66091ed5349SWolfram Sang 66191ed5349SWolfram Sang dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), 66291ed5349SWolfram Sang i2c_encode_flags_to_addr(client)); 66391ed5349SWolfram Sang } 66491ed5349SWolfram Sang 66591ed5349SWolfram Sang static int i2c_dev_irq_from_resources(const struct resource *resources, 66691ed5349SWolfram Sang unsigned int num_resources) 66791ed5349SWolfram Sang { 66891ed5349SWolfram Sang struct irq_data *irqd; 66991ed5349SWolfram Sang int i; 67091ed5349SWolfram Sang 67191ed5349SWolfram Sang for (i = 0; i < num_resources; i++) { 67291ed5349SWolfram Sang const struct resource *r = &resources[i]; 67391ed5349SWolfram Sang 67491ed5349SWolfram Sang if (resource_type(r) != IORESOURCE_IRQ) 67591ed5349SWolfram Sang continue; 67691ed5349SWolfram Sang 67791ed5349SWolfram Sang if (r->flags & IORESOURCE_BITS) { 67891ed5349SWolfram Sang irqd = irq_get_irq_data(r->start); 67991ed5349SWolfram Sang if (!irqd) 68091ed5349SWolfram Sang break; 68191ed5349SWolfram Sang 68291ed5349SWolfram Sang irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); 68391ed5349SWolfram Sang } 68491ed5349SWolfram Sang 68591ed5349SWolfram Sang return r->start; 68691ed5349SWolfram Sang } 68791ed5349SWolfram Sang 68891ed5349SWolfram Sang return 0; 68991ed5349SWolfram Sang } 69091ed5349SWolfram Sang 69191ed5349SWolfram Sang /** 69291ed5349SWolfram Sang * i2c_new_device - instantiate an i2c device 69391ed5349SWolfram Sang * @adap: the adapter managing the device 69491ed5349SWolfram Sang * @info: describes one I2C device; bus_num is ignored 69591ed5349SWolfram Sang * Context: can sleep 69691ed5349SWolfram Sang * 69791ed5349SWolfram Sang * Create an i2c device. Binding is handled through driver model 69891ed5349SWolfram Sang * probe()/remove() methods. A driver may be bound to this device when we 69991ed5349SWolfram Sang * return from this function, or any later moment (e.g. maybe hotplugging will 70091ed5349SWolfram Sang * load the driver module). This call is not appropriate for use by mainboard 70191ed5349SWolfram Sang * initialization logic, which usually runs during an arch_initcall() long 70291ed5349SWolfram Sang * before any i2c_adapter could exist. 70391ed5349SWolfram Sang * 70491ed5349SWolfram Sang * This returns the new i2c client, which may be saved for later use with 70591ed5349SWolfram Sang * i2c_unregister_device(); or NULL to indicate an error. 70691ed5349SWolfram Sang */ 70791ed5349SWolfram Sang struct i2c_client * 70891ed5349SWolfram Sang i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) 70991ed5349SWolfram Sang { 71091ed5349SWolfram Sang struct i2c_client *client; 71191ed5349SWolfram Sang int status; 71291ed5349SWolfram Sang 71391ed5349SWolfram Sang client = kzalloc(sizeof *client, GFP_KERNEL); 71491ed5349SWolfram Sang if (!client) 71591ed5349SWolfram Sang return NULL; 71691ed5349SWolfram Sang 71791ed5349SWolfram Sang client->adapter = adap; 71891ed5349SWolfram Sang 71991ed5349SWolfram Sang client->dev.platform_data = info->platform_data; 72091ed5349SWolfram Sang 72191ed5349SWolfram Sang if (info->archdata) 72291ed5349SWolfram Sang client->dev.archdata = *info->archdata; 72391ed5349SWolfram Sang 72491ed5349SWolfram Sang client->flags = info->flags; 72591ed5349SWolfram Sang client->addr = info->addr; 72691ed5349SWolfram Sang 72791ed5349SWolfram Sang client->irq = info->irq; 72891ed5349SWolfram Sang if (!client->irq) 72991ed5349SWolfram Sang client->irq = i2c_dev_irq_from_resources(info->resources, 73091ed5349SWolfram Sang info->num_resources); 73191ed5349SWolfram Sang 73291ed5349SWolfram Sang strlcpy(client->name, info->type, sizeof(client->name)); 73391ed5349SWolfram Sang 73491ed5349SWolfram Sang status = i2c_check_addr_validity(client->addr, client->flags); 73591ed5349SWolfram Sang if (status) { 73691ed5349SWolfram Sang dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", 73791ed5349SWolfram Sang client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); 73891ed5349SWolfram Sang goto out_err_silent; 73991ed5349SWolfram Sang } 74091ed5349SWolfram Sang 74191ed5349SWolfram Sang /* Check for address business */ 74291ed5349SWolfram Sang status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client)); 74391ed5349SWolfram Sang if (status) 74491ed5349SWolfram Sang goto out_err; 74591ed5349SWolfram Sang 74691ed5349SWolfram Sang client->dev.parent = &client->adapter->dev; 74791ed5349SWolfram Sang client->dev.bus = &i2c_bus_type; 74891ed5349SWolfram Sang client->dev.type = &i2c_client_type; 74991ed5349SWolfram Sang client->dev.of_node = info->of_node; 75091ed5349SWolfram Sang client->dev.fwnode = info->fwnode; 75191ed5349SWolfram Sang 752728fe6ceSHans de Goede i2c_dev_set_name(adap, client, info); 75391ed5349SWolfram Sang 75491ed5349SWolfram Sang if (info->properties) { 75591ed5349SWolfram Sang status = device_add_properties(&client->dev, info->properties); 75691ed5349SWolfram Sang if (status) { 75791ed5349SWolfram Sang dev_err(&adap->dev, 75891ed5349SWolfram Sang "Failed to add properties to client %s: %d\n", 75991ed5349SWolfram Sang client->name, status); 76091ed5349SWolfram Sang goto out_err; 76191ed5349SWolfram Sang } 76291ed5349SWolfram Sang } 76391ed5349SWolfram Sang 76491ed5349SWolfram Sang status = device_register(&client->dev); 76591ed5349SWolfram Sang if (status) 76691ed5349SWolfram Sang goto out_free_props; 76791ed5349SWolfram Sang 76891ed5349SWolfram Sang dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", 76991ed5349SWolfram Sang client->name, dev_name(&client->dev)); 77091ed5349SWolfram Sang 77191ed5349SWolfram Sang return client; 77291ed5349SWolfram Sang 77391ed5349SWolfram Sang out_free_props: 77491ed5349SWolfram Sang if (info->properties) 77591ed5349SWolfram Sang device_remove_properties(&client->dev); 77691ed5349SWolfram Sang out_err: 77791ed5349SWolfram Sang dev_err(&adap->dev, 77891ed5349SWolfram Sang "Failed to register i2c client %s at 0x%02x (%d)\n", 77991ed5349SWolfram Sang client->name, client->addr, status); 78091ed5349SWolfram Sang out_err_silent: 78191ed5349SWolfram Sang kfree(client); 78291ed5349SWolfram Sang return NULL; 78391ed5349SWolfram Sang } 78491ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_new_device); 78591ed5349SWolfram Sang 78691ed5349SWolfram Sang 78791ed5349SWolfram Sang /** 78891ed5349SWolfram Sang * i2c_unregister_device - reverse effect of i2c_new_device() 78991ed5349SWolfram Sang * @client: value returned from i2c_new_device() 79091ed5349SWolfram Sang * Context: can sleep 79191ed5349SWolfram Sang */ 79291ed5349SWolfram Sang void i2c_unregister_device(struct i2c_client *client) 79391ed5349SWolfram Sang { 7947b43dd19SAndy Shevchenko if (!client) 7957b43dd19SAndy Shevchenko return; 796e0638fa4SLixin Wang 797e0638fa4SLixin Wang if (client->dev.of_node) { 79891ed5349SWolfram Sang of_node_clear_flag(client->dev.of_node, OF_POPULATED); 799e0638fa4SLixin Wang of_node_put(client->dev.of_node); 800e0638fa4SLixin Wang } 801e0638fa4SLixin Wang 80291ed5349SWolfram Sang if (ACPI_COMPANION(&client->dev)) 80391ed5349SWolfram Sang acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev)); 80491ed5349SWolfram Sang device_unregister(&client->dev); 80591ed5349SWolfram Sang } 80691ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_unregister_device); 80791ed5349SWolfram Sang 80891ed5349SWolfram Sang 80991ed5349SWolfram Sang static const struct i2c_device_id dummy_id[] = { 81091ed5349SWolfram Sang { "dummy", 0 }, 81191ed5349SWolfram Sang { }, 81291ed5349SWolfram Sang }; 81391ed5349SWolfram Sang 81491ed5349SWolfram Sang static int dummy_probe(struct i2c_client *client, 81591ed5349SWolfram Sang const struct i2c_device_id *id) 81691ed5349SWolfram Sang { 81791ed5349SWolfram Sang return 0; 81891ed5349SWolfram Sang } 81991ed5349SWolfram Sang 82091ed5349SWolfram Sang static int dummy_remove(struct i2c_client *client) 82191ed5349SWolfram Sang { 82291ed5349SWolfram Sang return 0; 82391ed5349SWolfram Sang } 82491ed5349SWolfram Sang 82591ed5349SWolfram Sang static struct i2c_driver dummy_driver = { 82691ed5349SWolfram Sang .driver.name = "dummy", 82791ed5349SWolfram Sang .probe = dummy_probe, 82891ed5349SWolfram Sang .remove = dummy_remove, 82991ed5349SWolfram Sang .id_table = dummy_id, 83091ed5349SWolfram Sang }; 83191ed5349SWolfram Sang 83291ed5349SWolfram Sang /** 83391ed5349SWolfram Sang * i2c_new_dummy - return a new i2c device bound to a dummy driver 83491ed5349SWolfram Sang * @adapter: the adapter managing the device 83591ed5349SWolfram Sang * @address: seven bit address to be used 83691ed5349SWolfram Sang * Context: can sleep 83791ed5349SWolfram Sang * 83891ed5349SWolfram Sang * This returns an I2C client bound to the "dummy" driver, intended for use 83991ed5349SWolfram Sang * with devices that consume multiple addresses. Examples of such chips 84091ed5349SWolfram Sang * include various EEPROMS (like 24c04 and 24c08 models). 84191ed5349SWolfram Sang * 84291ed5349SWolfram Sang * These dummy devices have two main uses. First, most I2C and SMBus calls 84391ed5349SWolfram Sang * except i2c_transfer() need a client handle; the dummy will be that handle. 84491ed5349SWolfram Sang * And second, this prevents the specified address from being bound to a 84591ed5349SWolfram Sang * different driver. 84691ed5349SWolfram Sang * 84791ed5349SWolfram Sang * This returns the new i2c client, which should be saved for later use with 84891ed5349SWolfram Sang * i2c_unregister_device(); or NULL to indicate an error. 84991ed5349SWolfram Sang */ 85091ed5349SWolfram Sang struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) 85191ed5349SWolfram Sang { 85291ed5349SWolfram Sang struct i2c_board_info info = { 85391ed5349SWolfram Sang I2C_BOARD_INFO("dummy", address), 85491ed5349SWolfram Sang }; 85591ed5349SWolfram Sang 85691ed5349SWolfram Sang return i2c_new_device(adapter, &info); 85791ed5349SWolfram Sang } 85891ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_new_dummy); 85991ed5349SWolfram Sang 86091ed5349SWolfram Sang /** 86191ed5349SWolfram Sang * i2c_new_secondary_device - Helper to get the instantiated secondary address 86291ed5349SWolfram Sang * and create the associated device 86391ed5349SWolfram Sang * @client: Handle to the primary client 86491ed5349SWolfram Sang * @name: Handle to specify which secondary address to get 86591ed5349SWolfram Sang * @default_addr: Used as a fallback if no secondary address was specified 86691ed5349SWolfram Sang * Context: can sleep 86791ed5349SWolfram Sang * 86891ed5349SWolfram Sang * I2C clients can be composed of multiple I2C slaves bound together in a single 86991ed5349SWolfram Sang * component. The I2C client driver then binds to the master I2C slave and needs 87091ed5349SWolfram Sang * to create I2C dummy clients to communicate with all the other slaves. 87191ed5349SWolfram Sang * 87291ed5349SWolfram Sang * This function creates and returns an I2C dummy client whose I2C address is 87391ed5349SWolfram Sang * retrieved from the platform firmware based on the given slave name. If no 87491ed5349SWolfram Sang * address is specified by the firmware default_addr is used. 87591ed5349SWolfram Sang * 87691ed5349SWolfram Sang * On DT-based platforms the address is retrieved from the "reg" property entry 87791ed5349SWolfram Sang * cell whose "reg-names" value matches the slave name. 87891ed5349SWolfram Sang * 87991ed5349SWolfram Sang * This returns the new i2c client, which should be saved for later use with 88091ed5349SWolfram Sang * i2c_unregister_device(); or NULL to indicate an error. 88191ed5349SWolfram Sang */ 88291ed5349SWolfram Sang struct i2c_client *i2c_new_secondary_device(struct i2c_client *client, 88391ed5349SWolfram Sang const char *name, 88491ed5349SWolfram Sang u16 default_addr) 88591ed5349SWolfram Sang { 88691ed5349SWolfram Sang struct device_node *np = client->dev.of_node; 88791ed5349SWolfram Sang u32 addr = default_addr; 88891ed5349SWolfram Sang int i; 88991ed5349SWolfram Sang 89091ed5349SWolfram Sang if (np) { 89191ed5349SWolfram Sang i = of_property_match_string(np, "reg-names", name); 89291ed5349SWolfram Sang if (i >= 0) 89391ed5349SWolfram Sang of_property_read_u32_index(np, "reg", i, &addr); 89491ed5349SWolfram Sang } 89591ed5349SWolfram Sang 89691ed5349SWolfram Sang dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr); 89791ed5349SWolfram Sang return i2c_new_dummy(client->adapter, addr); 89891ed5349SWolfram Sang } 89991ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_new_secondary_device); 90091ed5349SWolfram Sang 90191ed5349SWolfram Sang /* ------------------------------------------------------------------------- */ 90291ed5349SWolfram Sang 90391ed5349SWolfram Sang /* I2C bus adapters -- one roots each I2C or SMBUS segment */ 90491ed5349SWolfram Sang 90591ed5349SWolfram Sang static void i2c_adapter_dev_release(struct device *dev) 90691ed5349SWolfram Sang { 90791ed5349SWolfram Sang struct i2c_adapter *adap = to_i2c_adapter(dev); 90891ed5349SWolfram Sang complete(&adap->dev_released); 90991ed5349SWolfram Sang } 91091ed5349SWolfram Sang 91191ed5349SWolfram Sang unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) 91291ed5349SWolfram Sang { 91391ed5349SWolfram Sang unsigned int depth = 0; 91491ed5349SWolfram Sang 91591ed5349SWolfram Sang while ((adapter = i2c_parent_is_i2c_adapter(adapter))) 91691ed5349SWolfram Sang depth++; 91791ed5349SWolfram Sang 91891ed5349SWolfram Sang WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES, 91991ed5349SWolfram Sang "adapter depth exceeds lockdep subclass limit\n"); 92091ed5349SWolfram Sang 92191ed5349SWolfram Sang return depth; 92291ed5349SWolfram Sang } 92391ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_adapter_depth); 92491ed5349SWolfram Sang 92591ed5349SWolfram Sang /* 92691ed5349SWolfram Sang * Let users instantiate I2C devices through sysfs. This can be used when 92791ed5349SWolfram Sang * platform initialization code doesn't contain the proper data for 92891ed5349SWolfram Sang * whatever reason. Also useful for drivers that do device detection and 92991ed5349SWolfram Sang * detection fails, either because the device uses an unexpected address, 93091ed5349SWolfram Sang * or this is a compatible device with different ID register values. 93191ed5349SWolfram Sang * 93291ed5349SWolfram Sang * Parameter checking may look overzealous, but we really don't want 93391ed5349SWolfram Sang * the user to provide incorrect parameters. 93491ed5349SWolfram Sang */ 93591ed5349SWolfram Sang static ssize_t 93691ed5349SWolfram Sang i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, 93791ed5349SWolfram Sang const char *buf, size_t count) 93891ed5349SWolfram Sang { 93991ed5349SWolfram Sang struct i2c_adapter *adap = to_i2c_adapter(dev); 94091ed5349SWolfram Sang struct i2c_board_info info; 94191ed5349SWolfram Sang struct i2c_client *client; 94291ed5349SWolfram Sang char *blank, end; 94391ed5349SWolfram Sang int res; 94491ed5349SWolfram Sang 94591ed5349SWolfram Sang memset(&info, 0, sizeof(struct i2c_board_info)); 94691ed5349SWolfram Sang 94791ed5349SWolfram Sang blank = strchr(buf, ' '); 94891ed5349SWolfram Sang if (!blank) { 94991ed5349SWolfram Sang dev_err(dev, "%s: Missing parameters\n", "new_device"); 95091ed5349SWolfram Sang return -EINVAL; 95191ed5349SWolfram Sang } 95291ed5349SWolfram Sang if (blank - buf > I2C_NAME_SIZE - 1) { 95391ed5349SWolfram Sang dev_err(dev, "%s: Invalid device name\n", "new_device"); 95491ed5349SWolfram Sang return -EINVAL; 95591ed5349SWolfram Sang } 95691ed5349SWolfram Sang memcpy(info.type, buf, blank - buf); 95791ed5349SWolfram Sang 95891ed5349SWolfram Sang /* Parse remaining parameters, reject extra parameters */ 95991ed5349SWolfram Sang res = sscanf(++blank, "%hi%c", &info.addr, &end); 96091ed5349SWolfram Sang if (res < 1) { 96191ed5349SWolfram Sang dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); 96291ed5349SWolfram Sang return -EINVAL; 96391ed5349SWolfram Sang } 96491ed5349SWolfram Sang if (res > 1 && end != '\n') { 96591ed5349SWolfram Sang dev_err(dev, "%s: Extra parameters\n", "new_device"); 96691ed5349SWolfram Sang return -EINVAL; 96791ed5349SWolfram Sang } 96891ed5349SWolfram Sang 96991ed5349SWolfram Sang if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) { 97091ed5349SWolfram Sang info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT; 97191ed5349SWolfram Sang info.flags |= I2C_CLIENT_TEN; 97291ed5349SWolfram Sang } 97391ed5349SWolfram Sang 97491ed5349SWolfram Sang if (info.addr & I2C_ADDR_OFFSET_SLAVE) { 97591ed5349SWolfram Sang info.addr &= ~I2C_ADDR_OFFSET_SLAVE; 97691ed5349SWolfram Sang info.flags |= I2C_CLIENT_SLAVE; 97791ed5349SWolfram Sang } 97891ed5349SWolfram Sang 97991ed5349SWolfram Sang client = i2c_new_device(adap, &info); 98091ed5349SWolfram Sang if (!client) 98191ed5349SWolfram Sang return -EINVAL; 98291ed5349SWolfram Sang 98391ed5349SWolfram Sang /* Keep track of the added device */ 98491ed5349SWolfram Sang mutex_lock(&adap->userspace_clients_lock); 98591ed5349SWolfram Sang list_add_tail(&client->detected, &adap->userspace_clients); 98691ed5349SWolfram Sang mutex_unlock(&adap->userspace_clients_lock); 98791ed5349SWolfram Sang dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", 98891ed5349SWolfram Sang info.type, info.addr); 98991ed5349SWolfram Sang 99091ed5349SWolfram Sang return count; 99191ed5349SWolfram Sang } 99291ed5349SWolfram Sang static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); 99391ed5349SWolfram Sang 99491ed5349SWolfram Sang /* 99591ed5349SWolfram Sang * And of course let the users delete the devices they instantiated, if 99691ed5349SWolfram Sang * they got it wrong. This interface can only be used to delete devices 99791ed5349SWolfram Sang * instantiated by i2c_sysfs_new_device above. This guarantees that we 99891ed5349SWolfram Sang * don't delete devices to which some kernel code still has references. 99991ed5349SWolfram Sang * 100091ed5349SWolfram Sang * Parameter checking may look overzealous, but we really don't want 100191ed5349SWolfram Sang * the user to delete the wrong device. 100291ed5349SWolfram Sang */ 100391ed5349SWolfram Sang static ssize_t 100491ed5349SWolfram Sang i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, 100591ed5349SWolfram Sang const char *buf, size_t count) 100691ed5349SWolfram Sang { 100791ed5349SWolfram Sang struct i2c_adapter *adap = to_i2c_adapter(dev); 100891ed5349SWolfram Sang struct i2c_client *client, *next; 100991ed5349SWolfram Sang unsigned short addr; 101091ed5349SWolfram Sang char end; 101191ed5349SWolfram Sang int res; 101291ed5349SWolfram Sang 101391ed5349SWolfram Sang /* Parse parameters, reject extra parameters */ 101491ed5349SWolfram Sang res = sscanf(buf, "%hi%c", &addr, &end); 101591ed5349SWolfram Sang if (res < 1) { 101691ed5349SWolfram Sang dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); 101791ed5349SWolfram Sang return -EINVAL; 101891ed5349SWolfram Sang } 101991ed5349SWolfram Sang if (res > 1 && end != '\n') { 102091ed5349SWolfram Sang dev_err(dev, "%s: Extra parameters\n", "delete_device"); 102191ed5349SWolfram Sang return -EINVAL; 102291ed5349SWolfram Sang } 102391ed5349SWolfram Sang 102491ed5349SWolfram Sang /* Make sure the device was added through sysfs */ 102591ed5349SWolfram Sang res = -ENOENT; 102691ed5349SWolfram Sang mutex_lock_nested(&adap->userspace_clients_lock, 102791ed5349SWolfram Sang i2c_adapter_depth(adap)); 102891ed5349SWolfram Sang list_for_each_entry_safe(client, next, &adap->userspace_clients, 102991ed5349SWolfram Sang detected) { 103091ed5349SWolfram Sang if (i2c_encode_flags_to_addr(client) == addr) { 103191ed5349SWolfram Sang dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", 103291ed5349SWolfram Sang "delete_device", client->name, client->addr); 103391ed5349SWolfram Sang 103491ed5349SWolfram Sang list_del(&client->detected); 103591ed5349SWolfram Sang i2c_unregister_device(client); 103691ed5349SWolfram Sang res = count; 103791ed5349SWolfram Sang break; 103891ed5349SWolfram Sang } 103991ed5349SWolfram Sang } 104091ed5349SWolfram Sang mutex_unlock(&adap->userspace_clients_lock); 104191ed5349SWolfram Sang 104291ed5349SWolfram Sang if (res < 0) 104391ed5349SWolfram Sang dev_err(dev, "%s: Can't find device in list\n", 104491ed5349SWolfram Sang "delete_device"); 104591ed5349SWolfram Sang return res; 104691ed5349SWolfram Sang } 104791ed5349SWolfram Sang static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, 104891ed5349SWolfram Sang i2c_sysfs_delete_device); 104991ed5349SWolfram Sang 105091ed5349SWolfram Sang static struct attribute *i2c_adapter_attrs[] = { 105191ed5349SWolfram Sang &dev_attr_name.attr, 105291ed5349SWolfram Sang &dev_attr_new_device.attr, 105391ed5349SWolfram Sang &dev_attr_delete_device.attr, 105491ed5349SWolfram Sang NULL 105591ed5349SWolfram Sang }; 105691ed5349SWolfram Sang ATTRIBUTE_GROUPS(i2c_adapter); 105791ed5349SWolfram Sang 105891ed5349SWolfram Sang struct device_type i2c_adapter_type = { 105991ed5349SWolfram Sang .groups = i2c_adapter_groups, 106091ed5349SWolfram Sang .release = i2c_adapter_dev_release, 106191ed5349SWolfram Sang }; 106291ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_adapter_type); 106391ed5349SWolfram Sang 106491ed5349SWolfram Sang /** 106591ed5349SWolfram Sang * i2c_verify_adapter - return parameter as i2c_adapter or NULL 106691ed5349SWolfram Sang * @dev: device, probably from some driver model iterator 106791ed5349SWolfram Sang * 106891ed5349SWolfram Sang * When traversing the driver model tree, perhaps using driver model 106991ed5349SWolfram Sang * iterators like @device_for_each_child(), you can't assume very much 107091ed5349SWolfram Sang * about the nodes you find. Use this function to avoid oopses caused 107191ed5349SWolfram Sang * by wrongly treating some non-I2C device as an i2c_adapter. 107291ed5349SWolfram Sang */ 107391ed5349SWolfram Sang struct i2c_adapter *i2c_verify_adapter(struct device *dev) 107491ed5349SWolfram Sang { 107591ed5349SWolfram Sang return (dev->type == &i2c_adapter_type) 107691ed5349SWolfram Sang ? to_i2c_adapter(dev) 107791ed5349SWolfram Sang : NULL; 107891ed5349SWolfram Sang } 107991ed5349SWolfram Sang EXPORT_SYMBOL(i2c_verify_adapter); 108091ed5349SWolfram Sang 108191ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 108291ed5349SWolfram Sang static struct class_compat *i2c_adapter_compat_class; 108391ed5349SWolfram Sang #endif 108491ed5349SWolfram Sang 108591ed5349SWolfram Sang static void i2c_scan_static_board_info(struct i2c_adapter *adapter) 108691ed5349SWolfram Sang { 108791ed5349SWolfram Sang struct i2c_devinfo *devinfo; 108891ed5349SWolfram Sang 108991ed5349SWolfram Sang down_read(&__i2c_board_lock); 109091ed5349SWolfram Sang list_for_each_entry(devinfo, &__i2c_board_list, list) { 109191ed5349SWolfram Sang if (devinfo->busnum == adapter->nr 109291ed5349SWolfram Sang && !i2c_new_device(adapter, 109391ed5349SWolfram Sang &devinfo->board_info)) 109491ed5349SWolfram Sang dev_err(&adapter->dev, 109591ed5349SWolfram Sang "Can't create device at 0x%02x\n", 109691ed5349SWolfram Sang devinfo->board_info.addr); 109791ed5349SWolfram Sang } 109891ed5349SWolfram Sang up_read(&__i2c_board_lock); 109991ed5349SWolfram Sang } 110091ed5349SWolfram Sang 110191ed5349SWolfram Sang static int i2c_do_add_adapter(struct i2c_driver *driver, 110291ed5349SWolfram Sang struct i2c_adapter *adap) 110391ed5349SWolfram Sang { 110491ed5349SWolfram Sang /* Detect supported devices on that bus, and instantiate them */ 110591ed5349SWolfram Sang i2c_detect(adap, driver); 110691ed5349SWolfram Sang 110791ed5349SWolfram Sang /* Let legacy drivers scan this bus for matching devices */ 110891ed5349SWolfram Sang if (driver->attach_adapter) { 110991ed5349SWolfram Sang dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n", 111091ed5349SWolfram Sang driver->driver.name); 111191ed5349SWolfram Sang dev_warn(&adap->dev, 111291ed5349SWolfram Sang "Please use another way to instantiate your i2c_client\n"); 111391ed5349SWolfram Sang /* We ignore the return code; if it fails, too bad */ 111491ed5349SWolfram Sang driver->attach_adapter(adap); 111591ed5349SWolfram Sang } 111691ed5349SWolfram Sang return 0; 111791ed5349SWolfram Sang } 111891ed5349SWolfram Sang 111991ed5349SWolfram Sang static int __process_new_adapter(struct device_driver *d, void *data) 112091ed5349SWolfram Sang { 112191ed5349SWolfram Sang return i2c_do_add_adapter(to_i2c_driver(d), data); 112291ed5349SWolfram Sang } 112391ed5349SWolfram Sang 112491ed5349SWolfram Sang static const struct i2c_lock_operations i2c_adapter_lock_ops = { 112591ed5349SWolfram Sang .lock_bus = i2c_adapter_lock_bus, 112691ed5349SWolfram Sang .trylock_bus = i2c_adapter_trylock_bus, 112791ed5349SWolfram Sang .unlock_bus = i2c_adapter_unlock_bus, 112891ed5349SWolfram Sang }; 112991ed5349SWolfram Sang 113091ed5349SWolfram Sang static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap) 113191ed5349SWolfram Sang { 113291ed5349SWolfram Sang struct irq_domain *domain = adap->host_notify_domain; 113391ed5349SWolfram Sang irq_hw_number_t hwirq; 113491ed5349SWolfram Sang 113591ed5349SWolfram Sang if (!domain) 113691ed5349SWolfram Sang return; 113791ed5349SWolfram Sang 113891ed5349SWolfram Sang for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++) 113991ed5349SWolfram Sang irq_dispose_mapping(irq_find_mapping(domain, hwirq)); 114091ed5349SWolfram Sang 114191ed5349SWolfram Sang irq_domain_remove(domain); 114291ed5349SWolfram Sang adap->host_notify_domain = NULL; 114391ed5349SWolfram Sang } 114491ed5349SWolfram Sang 114591ed5349SWolfram Sang static int i2c_host_notify_irq_map(struct irq_domain *h, 114691ed5349SWolfram Sang unsigned int virq, 114791ed5349SWolfram Sang irq_hw_number_t hw_irq_num) 114891ed5349SWolfram Sang { 114991ed5349SWolfram Sang irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq); 115091ed5349SWolfram Sang 115191ed5349SWolfram Sang return 0; 115291ed5349SWolfram Sang } 115391ed5349SWolfram Sang 115491ed5349SWolfram Sang static const struct irq_domain_ops i2c_host_notify_irq_ops = { 115591ed5349SWolfram Sang .map = i2c_host_notify_irq_map, 115691ed5349SWolfram Sang }; 115791ed5349SWolfram Sang 115891ed5349SWolfram Sang static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap) 115991ed5349SWolfram Sang { 116091ed5349SWolfram Sang struct irq_domain *domain; 116191ed5349SWolfram Sang 116291ed5349SWolfram Sang if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY)) 116391ed5349SWolfram Sang return 0; 116491ed5349SWolfram Sang 116591ed5349SWolfram Sang domain = irq_domain_create_linear(adap->dev.fwnode, 116691ed5349SWolfram Sang I2C_ADDR_7BITS_COUNT, 116791ed5349SWolfram Sang &i2c_host_notify_irq_ops, adap); 116891ed5349SWolfram Sang if (!domain) 116991ed5349SWolfram Sang return -ENOMEM; 117091ed5349SWolfram Sang 117191ed5349SWolfram Sang adap->host_notify_domain = domain; 117291ed5349SWolfram Sang 117391ed5349SWolfram Sang return 0; 117491ed5349SWolfram Sang } 117591ed5349SWolfram Sang 117691ed5349SWolfram Sang /** 117791ed5349SWolfram Sang * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct 117891ed5349SWolfram Sang * I2C client. 117991ed5349SWolfram Sang * @adap: the adapter 118091ed5349SWolfram Sang * @addr: the I2C address of the notifying device 118191ed5349SWolfram Sang * Context: can't sleep 118291ed5349SWolfram Sang * 118391ed5349SWolfram Sang * Helper function to be called from an I2C bus driver's interrupt 118491ed5349SWolfram Sang * handler. It will schedule the Host Notify IRQ. 118591ed5349SWolfram Sang */ 118691ed5349SWolfram Sang int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr) 118791ed5349SWolfram Sang { 118891ed5349SWolfram Sang int irq; 118991ed5349SWolfram Sang 119091ed5349SWolfram Sang if (!adap) 119191ed5349SWolfram Sang return -EINVAL; 119291ed5349SWolfram Sang 119391ed5349SWolfram Sang irq = irq_find_mapping(adap->host_notify_domain, addr); 119491ed5349SWolfram Sang if (irq <= 0) 119591ed5349SWolfram Sang return -ENXIO; 119691ed5349SWolfram Sang 119791ed5349SWolfram Sang generic_handle_irq(irq); 119891ed5349SWolfram Sang 119991ed5349SWolfram Sang return 0; 120091ed5349SWolfram Sang } 120191ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify); 120291ed5349SWolfram Sang 120391ed5349SWolfram Sang static int i2c_register_adapter(struct i2c_adapter *adap) 120491ed5349SWolfram Sang { 120591ed5349SWolfram Sang int res = -EINVAL; 120691ed5349SWolfram Sang 120791ed5349SWolfram Sang /* Can't register until after driver model init */ 120891ed5349SWolfram Sang if (WARN_ON(!is_registered)) { 120991ed5349SWolfram Sang res = -EAGAIN; 121091ed5349SWolfram Sang goto out_list; 121191ed5349SWolfram Sang } 121291ed5349SWolfram Sang 121391ed5349SWolfram Sang /* Sanity checks */ 121491ed5349SWolfram Sang if (WARN(!adap->name[0], "i2c adapter has no name")) 121591ed5349SWolfram Sang goto out_list; 121691ed5349SWolfram Sang 121791ed5349SWolfram Sang if (!adap->algo) { 121891ed5349SWolfram Sang pr_err("adapter '%s': no algo supplied!\n", adap->name); 121991ed5349SWolfram Sang goto out_list; 122091ed5349SWolfram Sang } 122191ed5349SWolfram Sang 122291ed5349SWolfram Sang if (!adap->lock_ops) 122391ed5349SWolfram Sang adap->lock_ops = &i2c_adapter_lock_ops; 122491ed5349SWolfram Sang 122591ed5349SWolfram Sang rt_mutex_init(&adap->bus_lock); 122691ed5349SWolfram Sang rt_mutex_init(&adap->mux_lock); 122791ed5349SWolfram Sang mutex_init(&adap->userspace_clients_lock); 122891ed5349SWolfram Sang INIT_LIST_HEAD(&adap->userspace_clients); 122991ed5349SWolfram Sang 123091ed5349SWolfram Sang /* Set default timeout to 1 second if not already set */ 123191ed5349SWolfram Sang if (adap->timeout == 0) 123291ed5349SWolfram Sang adap->timeout = HZ; 123391ed5349SWolfram Sang 123491ed5349SWolfram Sang /* register soft irqs for Host Notify */ 123591ed5349SWolfram Sang res = i2c_setup_host_notify_irq_domain(adap); 123691ed5349SWolfram Sang if (res) { 123791ed5349SWolfram Sang pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n", 123891ed5349SWolfram Sang adap->name, res); 123991ed5349SWolfram Sang goto out_list; 124091ed5349SWolfram Sang } 124191ed5349SWolfram Sang 124291ed5349SWolfram Sang dev_set_name(&adap->dev, "i2c-%d", adap->nr); 124391ed5349SWolfram Sang adap->dev.bus = &i2c_bus_type; 124491ed5349SWolfram Sang adap->dev.type = &i2c_adapter_type; 124591ed5349SWolfram Sang res = device_register(&adap->dev); 124691ed5349SWolfram Sang if (res) { 124791ed5349SWolfram Sang pr_err("adapter '%s': can't register device (%d)\n", adap->name, res); 124891ed5349SWolfram Sang goto out_list; 124991ed5349SWolfram Sang } 125091ed5349SWolfram Sang 1251f8756c67SPhil Reid res = of_i2c_setup_smbus_alert(adap); 1252f8756c67SPhil Reid if (res) 1253f8756c67SPhil Reid goto out_reg; 1254f8756c67SPhil Reid 125591ed5349SWolfram Sang dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); 125691ed5349SWolfram Sang 125791ed5349SWolfram Sang pm_runtime_no_callbacks(&adap->dev); 125891ed5349SWolfram Sang pm_suspend_ignore_children(&adap->dev, true); 125991ed5349SWolfram Sang pm_runtime_enable(&adap->dev); 126091ed5349SWolfram Sang 126191ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 126291ed5349SWolfram Sang res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, 126391ed5349SWolfram Sang adap->dev.parent); 126491ed5349SWolfram Sang if (res) 126591ed5349SWolfram Sang dev_warn(&adap->dev, 126691ed5349SWolfram Sang "Failed to create compatibility class link\n"); 126791ed5349SWolfram Sang #endif 126891ed5349SWolfram Sang 126991ed5349SWolfram Sang i2c_init_recovery(adap); 127091ed5349SWolfram Sang 127191ed5349SWolfram Sang /* create pre-declared device nodes */ 127291ed5349SWolfram Sang of_i2c_register_devices(adap); 127391ed5349SWolfram Sang i2c_acpi_register_devices(adap); 127491ed5349SWolfram Sang i2c_acpi_install_space_handler(adap); 127591ed5349SWolfram Sang 127691ed5349SWolfram Sang if (adap->nr < __i2c_first_dynamic_bus_num) 127791ed5349SWolfram Sang i2c_scan_static_board_info(adap); 127891ed5349SWolfram Sang 127991ed5349SWolfram Sang /* Notify drivers */ 128091ed5349SWolfram Sang mutex_lock(&core_lock); 128191ed5349SWolfram Sang bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); 128291ed5349SWolfram Sang mutex_unlock(&core_lock); 128391ed5349SWolfram Sang 128491ed5349SWolfram Sang return 0; 128591ed5349SWolfram Sang 1286f8756c67SPhil Reid out_reg: 1287f8756c67SPhil Reid init_completion(&adap->dev_released); 1288f8756c67SPhil Reid device_unregister(&adap->dev); 1289f8756c67SPhil Reid wait_for_completion(&adap->dev_released); 129091ed5349SWolfram Sang out_list: 129191ed5349SWolfram Sang mutex_lock(&core_lock); 129291ed5349SWolfram Sang idr_remove(&i2c_adapter_idr, adap->nr); 129391ed5349SWolfram Sang mutex_unlock(&core_lock); 129491ed5349SWolfram Sang return res; 129591ed5349SWolfram Sang } 129691ed5349SWolfram Sang 129791ed5349SWolfram Sang /** 129891ed5349SWolfram Sang * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 129991ed5349SWolfram Sang * @adap: the adapter to register (with adap->nr initialized) 130091ed5349SWolfram Sang * Context: can sleep 130191ed5349SWolfram Sang * 130291ed5349SWolfram Sang * See i2c_add_numbered_adapter() for details. 130391ed5349SWolfram Sang */ 130491ed5349SWolfram Sang static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) 130591ed5349SWolfram Sang { 130691ed5349SWolfram Sang int id; 130791ed5349SWolfram Sang 130891ed5349SWolfram Sang mutex_lock(&core_lock); 130991ed5349SWolfram Sang id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL); 131091ed5349SWolfram Sang mutex_unlock(&core_lock); 131191ed5349SWolfram Sang if (WARN(id < 0, "couldn't get idr")) 131291ed5349SWolfram Sang return id == -ENOSPC ? -EBUSY : id; 131391ed5349SWolfram Sang 131491ed5349SWolfram Sang return i2c_register_adapter(adap); 131591ed5349SWolfram Sang } 131691ed5349SWolfram Sang 131791ed5349SWolfram Sang /** 131891ed5349SWolfram Sang * i2c_add_adapter - declare i2c adapter, use dynamic bus number 131991ed5349SWolfram Sang * @adapter: the adapter to add 132091ed5349SWolfram Sang * Context: can sleep 132191ed5349SWolfram Sang * 132291ed5349SWolfram Sang * This routine is used to declare an I2C adapter when its bus number 132391ed5349SWolfram Sang * doesn't matter or when its bus number is specified by an dt alias. 132491ed5349SWolfram Sang * Examples of bases when the bus number doesn't matter: I2C adapters 132591ed5349SWolfram Sang * dynamically added by USB links or PCI plugin cards. 132691ed5349SWolfram Sang * 132791ed5349SWolfram Sang * When this returns zero, a new bus number was allocated and stored 132891ed5349SWolfram Sang * in adap->nr, and the specified adapter became available for clients. 132991ed5349SWolfram Sang * Otherwise, a negative errno value is returned. 133091ed5349SWolfram Sang */ 133191ed5349SWolfram Sang int i2c_add_adapter(struct i2c_adapter *adapter) 133291ed5349SWolfram Sang { 133391ed5349SWolfram Sang struct device *dev = &adapter->dev; 133491ed5349SWolfram Sang int id; 133591ed5349SWolfram Sang 133691ed5349SWolfram Sang if (dev->of_node) { 133791ed5349SWolfram Sang id = of_alias_get_id(dev->of_node, "i2c"); 133891ed5349SWolfram Sang if (id >= 0) { 133991ed5349SWolfram Sang adapter->nr = id; 134091ed5349SWolfram Sang return __i2c_add_numbered_adapter(adapter); 134191ed5349SWolfram Sang } 134291ed5349SWolfram Sang } 134391ed5349SWolfram Sang 134491ed5349SWolfram Sang mutex_lock(&core_lock); 134591ed5349SWolfram Sang id = idr_alloc(&i2c_adapter_idr, adapter, 134691ed5349SWolfram Sang __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); 134791ed5349SWolfram Sang mutex_unlock(&core_lock); 134891ed5349SWolfram Sang if (WARN(id < 0, "couldn't get idr")) 134991ed5349SWolfram Sang return id; 135091ed5349SWolfram Sang 135191ed5349SWolfram Sang adapter->nr = id; 135291ed5349SWolfram Sang 135391ed5349SWolfram Sang return i2c_register_adapter(adapter); 135491ed5349SWolfram Sang } 135591ed5349SWolfram Sang EXPORT_SYMBOL(i2c_add_adapter); 135691ed5349SWolfram Sang 135791ed5349SWolfram Sang /** 135891ed5349SWolfram Sang * i2c_add_numbered_adapter - declare i2c adapter, use static bus number 135991ed5349SWolfram Sang * @adap: the adapter to register (with adap->nr initialized) 136091ed5349SWolfram Sang * Context: can sleep 136191ed5349SWolfram Sang * 136291ed5349SWolfram Sang * This routine is used to declare an I2C adapter when its bus number 136391ed5349SWolfram Sang * matters. For example, use it for I2C adapters from system-on-chip CPUs, 136491ed5349SWolfram Sang * or otherwise built in to the system's mainboard, and where i2c_board_info 136591ed5349SWolfram Sang * is used to properly configure I2C devices. 136691ed5349SWolfram Sang * 136791ed5349SWolfram Sang * If the requested bus number is set to -1, then this function will behave 136891ed5349SWolfram Sang * identically to i2c_add_adapter, and will dynamically assign a bus number. 136991ed5349SWolfram Sang * 137091ed5349SWolfram Sang * If no devices have pre-been declared for this bus, then be sure to 137191ed5349SWolfram Sang * register the adapter before any dynamically allocated ones. Otherwise 137291ed5349SWolfram Sang * the required bus ID may not be available. 137391ed5349SWolfram Sang * 137491ed5349SWolfram Sang * When this returns zero, the specified adapter became available for 137591ed5349SWolfram Sang * clients using the bus number provided in adap->nr. Also, the table 137691ed5349SWolfram Sang * of I2C devices pre-declared using i2c_register_board_info() is scanned, 137791ed5349SWolfram Sang * and the appropriate driver model device nodes are created. Otherwise, a 137891ed5349SWolfram Sang * negative errno value is returned. 137991ed5349SWolfram Sang */ 138091ed5349SWolfram Sang int i2c_add_numbered_adapter(struct i2c_adapter *adap) 138191ed5349SWolfram Sang { 138291ed5349SWolfram Sang if (adap->nr == -1) /* -1 means dynamically assign bus id */ 138391ed5349SWolfram Sang return i2c_add_adapter(adap); 138491ed5349SWolfram Sang 138591ed5349SWolfram Sang return __i2c_add_numbered_adapter(adap); 138691ed5349SWolfram Sang } 138791ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); 138891ed5349SWolfram Sang 138991ed5349SWolfram Sang static void i2c_do_del_adapter(struct i2c_driver *driver, 139091ed5349SWolfram Sang struct i2c_adapter *adapter) 139191ed5349SWolfram Sang { 139291ed5349SWolfram Sang struct i2c_client *client, *_n; 139391ed5349SWolfram Sang 139491ed5349SWolfram Sang /* Remove the devices we created ourselves as the result of hardware 139591ed5349SWolfram Sang * probing (using a driver's detect method) */ 139691ed5349SWolfram Sang list_for_each_entry_safe(client, _n, &driver->clients, detected) { 139791ed5349SWolfram Sang if (client->adapter == adapter) { 139891ed5349SWolfram Sang dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", 139991ed5349SWolfram Sang client->name, client->addr); 140091ed5349SWolfram Sang list_del(&client->detected); 140191ed5349SWolfram Sang i2c_unregister_device(client); 140291ed5349SWolfram Sang } 140391ed5349SWolfram Sang } 140491ed5349SWolfram Sang } 140591ed5349SWolfram Sang 140691ed5349SWolfram Sang static int __unregister_client(struct device *dev, void *dummy) 140791ed5349SWolfram Sang { 140891ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 140991ed5349SWolfram Sang if (client && strcmp(client->name, "dummy")) 141091ed5349SWolfram Sang i2c_unregister_device(client); 141191ed5349SWolfram Sang return 0; 141291ed5349SWolfram Sang } 141391ed5349SWolfram Sang 141491ed5349SWolfram Sang static int __unregister_dummy(struct device *dev, void *dummy) 141591ed5349SWolfram Sang { 141691ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 141791ed5349SWolfram Sang i2c_unregister_device(client); 141891ed5349SWolfram Sang return 0; 141991ed5349SWolfram Sang } 142091ed5349SWolfram Sang 142191ed5349SWolfram Sang static int __process_removed_adapter(struct device_driver *d, void *data) 142291ed5349SWolfram Sang { 142391ed5349SWolfram Sang i2c_do_del_adapter(to_i2c_driver(d), data); 142491ed5349SWolfram Sang return 0; 142591ed5349SWolfram Sang } 142691ed5349SWolfram Sang 142791ed5349SWolfram Sang /** 142891ed5349SWolfram Sang * i2c_del_adapter - unregister I2C adapter 142991ed5349SWolfram Sang * @adap: the adapter being unregistered 143091ed5349SWolfram Sang * Context: can sleep 143191ed5349SWolfram Sang * 143291ed5349SWolfram Sang * This unregisters an I2C adapter which was previously registered 143391ed5349SWolfram Sang * by @i2c_add_adapter or @i2c_add_numbered_adapter. 143491ed5349SWolfram Sang */ 143591ed5349SWolfram Sang void i2c_del_adapter(struct i2c_adapter *adap) 143691ed5349SWolfram Sang { 143791ed5349SWolfram Sang struct i2c_adapter *found; 143891ed5349SWolfram Sang struct i2c_client *client, *next; 143991ed5349SWolfram Sang 144091ed5349SWolfram Sang /* First make sure that this adapter was ever added */ 144191ed5349SWolfram Sang mutex_lock(&core_lock); 144291ed5349SWolfram Sang found = idr_find(&i2c_adapter_idr, adap->nr); 144391ed5349SWolfram Sang mutex_unlock(&core_lock); 144491ed5349SWolfram Sang if (found != adap) { 144591ed5349SWolfram Sang pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name); 144691ed5349SWolfram Sang return; 144791ed5349SWolfram Sang } 144891ed5349SWolfram Sang 144991ed5349SWolfram Sang i2c_acpi_remove_space_handler(adap); 145091ed5349SWolfram Sang /* Tell drivers about this removal */ 145191ed5349SWolfram Sang mutex_lock(&core_lock); 145291ed5349SWolfram Sang bus_for_each_drv(&i2c_bus_type, NULL, adap, 145391ed5349SWolfram Sang __process_removed_adapter); 145491ed5349SWolfram Sang mutex_unlock(&core_lock); 145591ed5349SWolfram Sang 145691ed5349SWolfram Sang /* Remove devices instantiated from sysfs */ 145791ed5349SWolfram Sang mutex_lock_nested(&adap->userspace_clients_lock, 145891ed5349SWolfram Sang i2c_adapter_depth(adap)); 145991ed5349SWolfram Sang list_for_each_entry_safe(client, next, &adap->userspace_clients, 146091ed5349SWolfram Sang detected) { 146191ed5349SWolfram Sang dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, 146291ed5349SWolfram Sang client->addr); 146391ed5349SWolfram Sang list_del(&client->detected); 146491ed5349SWolfram Sang i2c_unregister_device(client); 146591ed5349SWolfram Sang } 146691ed5349SWolfram Sang mutex_unlock(&adap->userspace_clients_lock); 146791ed5349SWolfram Sang 146891ed5349SWolfram Sang /* Detach any active clients. This can't fail, thus we do not 146991ed5349SWolfram Sang * check the returned value. This is a two-pass process, because 147091ed5349SWolfram Sang * we can't remove the dummy devices during the first pass: they 147191ed5349SWolfram Sang * could have been instantiated by real devices wishing to clean 147291ed5349SWolfram Sang * them up properly, so we give them a chance to do that first. */ 147391ed5349SWolfram Sang device_for_each_child(&adap->dev, NULL, __unregister_client); 147491ed5349SWolfram Sang device_for_each_child(&adap->dev, NULL, __unregister_dummy); 147591ed5349SWolfram Sang 147691ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 147791ed5349SWolfram Sang class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, 147891ed5349SWolfram Sang adap->dev.parent); 147991ed5349SWolfram Sang #endif 148091ed5349SWolfram Sang 148191ed5349SWolfram Sang /* device name is gone after device_unregister */ 148291ed5349SWolfram Sang dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); 148391ed5349SWolfram Sang 148491ed5349SWolfram Sang pm_runtime_disable(&adap->dev); 148591ed5349SWolfram Sang 148691ed5349SWolfram Sang i2c_host_notify_irq_teardown(adap); 148791ed5349SWolfram Sang 148891ed5349SWolfram Sang /* wait until all references to the device are gone 148991ed5349SWolfram Sang * 149091ed5349SWolfram Sang * FIXME: This is old code and should ideally be replaced by an 149191ed5349SWolfram Sang * alternative which results in decoupling the lifetime of the struct 149291ed5349SWolfram Sang * device from the i2c_adapter, like spi or netdev do. Any solution 149391ed5349SWolfram Sang * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled! 149491ed5349SWolfram Sang */ 149591ed5349SWolfram Sang init_completion(&adap->dev_released); 149691ed5349SWolfram Sang device_unregister(&adap->dev); 149791ed5349SWolfram Sang wait_for_completion(&adap->dev_released); 149891ed5349SWolfram Sang 149991ed5349SWolfram Sang /* free bus id */ 150091ed5349SWolfram Sang mutex_lock(&core_lock); 150191ed5349SWolfram Sang idr_remove(&i2c_adapter_idr, adap->nr); 150291ed5349SWolfram Sang mutex_unlock(&core_lock); 150391ed5349SWolfram Sang 150491ed5349SWolfram Sang /* Clear the device structure in case this adapter is ever going to be 150591ed5349SWolfram Sang added again */ 150691ed5349SWolfram Sang memset(&adap->dev, 0, sizeof(adap->dev)); 150791ed5349SWolfram Sang } 150891ed5349SWolfram Sang EXPORT_SYMBOL(i2c_del_adapter); 150991ed5349SWolfram Sang 151091ed5349SWolfram Sang /** 151191ed5349SWolfram Sang * i2c_parse_fw_timings - get I2C related timing parameters from firmware 151291ed5349SWolfram Sang * @dev: The device to scan for I2C timing properties 151391ed5349SWolfram Sang * @t: the i2c_timings struct to be filled with values 151491ed5349SWolfram Sang * @use_defaults: bool to use sane defaults derived from the I2C specification 151591ed5349SWolfram Sang * when properties are not found, otherwise use 0 151691ed5349SWolfram Sang * 151791ed5349SWolfram Sang * Scan the device for the generic I2C properties describing timing parameters 151891ed5349SWolfram Sang * for the signal and fill the given struct with the results. If a property was 151991ed5349SWolfram Sang * not found and use_defaults was true, then maximum timings are assumed which 152091ed5349SWolfram Sang * are derived from the I2C specification. If use_defaults is not used, the 152191ed5349SWolfram Sang * results will be 0, so drivers can apply their own defaults later. The latter 152291ed5349SWolfram Sang * is mainly intended for avoiding regressions of existing drivers which want 152391ed5349SWolfram Sang * to switch to this function. New drivers almost always should use the defaults. 152491ed5349SWolfram Sang */ 152591ed5349SWolfram Sang 152691ed5349SWolfram Sang void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults) 152791ed5349SWolfram Sang { 152891ed5349SWolfram Sang int ret; 152991ed5349SWolfram Sang 153091ed5349SWolfram Sang memset(t, 0, sizeof(*t)); 153191ed5349SWolfram Sang 153291ed5349SWolfram Sang ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz); 153391ed5349SWolfram Sang if (ret && use_defaults) 153491ed5349SWolfram Sang t->bus_freq_hz = 100000; 153591ed5349SWolfram Sang 153691ed5349SWolfram Sang ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns); 153791ed5349SWolfram Sang if (ret && use_defaults) { 153891ed5349SWolfram Sang if (t->bus_freq_hz <= 100000) 153991ed5349SWolfram Sang t->scl_rise_ns = 1000; 154091ed5349SWolfram Sang else if (t->bus_freq_hz <= 400000) 154191ed5349SWolfram Sang t->scl_rise_ns = 300; 154291ed5349SWolfram Sang else 154391ed5349SWolfram Sang t->scl_rise_ns = 120; 154491ed5349SWolfram Sang } 154591ed5349SWolfram Sang 154691ed5349SWolfram Sang ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns); 154791ed5349SWolfram Sang if (ret && use_defaults) { 154891ed5349SWolfram Sang if (t->bus_freq_hz <= 400000) 154991ed5349SWolfram Sang t->scl_fall_ns = 300; 155091ed5349SWolfram Sang else 155191ed5349SWolfram Sang t->scl_fall_ns = 120; 155291ed5349SWolfram Sang } 155391ed5349SWolfram Sang 155491ed5349SWolfram Sang device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns); 155591ed5349SWolfram Sang 155691ed5349SWolfram Sang ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns); 155791ed5349SWolfram Sang if (ret && use_defaults) 155891ed5349SWolfram Sang t->sda_fall_ns = t->scl_fall_ns; 155991ed5349SWolfram Sang } 156091ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_parse_fw_timings); 156191ed5349SWolfram Sang 156291ed5349SWolfram Sang /* ------------------------------------------------------------------------- */ 156391ed5349SWolfram Sang 156491ed5349SWolfram Sang int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) 156591ed5349SWolfram Sang { 156691ed5349SWolfram Sang int res; 156791ed5349SWolfram Sang 156891ed5349SWolfram Sang mutex_lock(&core_lock); 156991ed5349SWolfram Sang res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); 157091ed5349SWolfram Sang mutex_unlock(&core_lock); 157191ed5349SWolfram Sang 157291ed5349SWolfram Sang return res; 157391ed5349SWolfram Sang } 157491ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_for_each_dev); 157591ed5349SWolfram Sang 157691ed5349SWolfram Sang static int __process_new_driver(struct device *dev, void *data) 157791ed5349SWolfram Sang { 157891ed5349SWolfram Sang if (dev->type != &i2c_adapter_type) 157991ed5349SWolfram Sang return 0; 158091ed5349SWolfram Sang return i2c_do_add_adapter(data, to_i2c_adapter(dev)); 158191ed5349SWolfram Sang } 158291ed5349SWolfram Sang 158391ed5349SWolfram Sang /* 158491ed5349SWolfram Sang * An i2c_driver is used with one or more i2c_client (device) nodes to access 158591ed5349SWolfram Sang * i2c slave chips, on a bus instance associated with some i2c_adapter. 158691ed5349SWolfram Sang */ 158791ed5349SWolfram Sang 158891ed5349SWolfram Sang int i2c_register_driver(struct module *owner, struct i2c_driver *driver) 158991ed5349SWolfram Sang { 159091ed5349SWolfram Sang int res; 159191ed5349SWolfram Sang 159291ed5349SWolfram Sang /* Can't register until after driver model init */ 159391ed5349SWolfram Sang if (WARN_ON(!is_registered)) 159491ed5349SWolfram Sang return -EAGAIN; 159591ed5349SWolfram Sang 159691ed5349SWolfram Sang /* add the driver to the list of i2c drivers in the driver core */ 159791ed5349SWolfram Sang driver->driver.owner = owner; 159891ed5349SWolfram Sang driver->driver.bus = &i2c_bus_type; 159991ed5349SWolfram Sang INIT_LIST_HEAD(&driver->clients); 160091ed5349SWolfram Sang 160191ed5349SWolfram Sang /* When registration returns, the driver core 160291ed5349SWolfram Sang * will have called probe() for all matching-but-unbound devices. 160391ed5349SWolfram Sang */ 160491ed5349SWolfram Sang res = driver_register(&driver->driver); 160591ed5349SWolfram Sang if (res) 160691ed5349SWolfram Sang return res; 160791ed5349SWolfram Sang 160891ed5349SWolfram Sang pr_debug("driver [%s] registered\n", driver->driver.name); 160991ed5349SWolfram Sang 161091ed5349SWolfram Sang /* Walk the adapters that are already present */ 161191ed5349SWolfram Sang i2c_for_each_dev(driver, __process_new_driver); 161291ed5349SWolfram Sang 161391ed5349SWolfram Sang return 0; 161491ed5349SWolfram Sang } 161591ed5349SWolfram Sang EXPORT_SYMBOL(i2c_register_driver); 161691ed5349SWolfram Sang 161791ed5349SWolfram Sang static int __process_removed_driver(struct device *dev, void *data) 161891ed5349SWolfram Sang { 161991ed5349SWolfram Sang if (dev->type == &i2c_adapter_type) 162091ed5349SWolfram Sang i2c_do_del_adapter(data, to_i2c_adapter(dev)); 162191ed5349SWolfram Sang return 0; 162291ed5349SWolfram Sang } 162391ed5349SWolfram Sang 162491ed5349SWolfram Sang /** 162591ed5349SWolfram Sang * i2c_del_driver - unregister I2C driver 162691ed5349SWolfram Sang * @driver: the driver being unregistered 162791ed5349SWolfram Sang * Context: can sleep 162891ed5349SWolfram Sang */ 162991ed5349SWolfram Sang void i2c_del_driver(struct i2c_driver *driver) 163091ed5349SWolfram Sang { 163191ed5349SWolfram Sang i2c_for_each_dev(driver, __process_removed_driver); 163291ed5349SWolfram Sang 163391ed5349SWolfram Sang driver_unregister(&driver->driver); 163491ed5349SWolfram Sang pr_debug("driver [%s] unregistered\n", driver->driver.name); 163591ed5349SWolfram Sang } 163691ed5349SWolfram Sang EXPORT_SYMBOL(i2c_del_driver); 163791ed5349SWolfram Sang 163891ed5349SWolfram Sang /* ------------------------------------------------------------------------- */ 163991ed5349SWolfram Sang 164091ed5349SWolfram Sang /** 164191ed5349SWolfram Sang * i2c_use_client - increments the reference count of the i2c client structure 164291ed5349SWolfram Sang * @client: the client being referenced 164391ed5349SWolfram Sang * 164491ed5349SWolfram Sang * Each live reference to a client should be refcounted. The driver model does 164591ed5349SWolfram Sang * that automatically as part of driver binding, so that most drivers don't 164691ed5349SWolfram Sang * need to do this explicitly: they hold a reference until they're unbound 164791ed5349SWolfram Sang * from the device. 164891ed5349SWolfram Sang * 164991ed5349SWolfram Sang * A pointer to the client with the incremented reference counter is returned. 165091ed5349SWolfram Sang */ 165191ed5349SWolfram Sang struct i2c_client *i2c_use_client(struct i2c_client *client) 165291ed5349SWolfram Sang { 165391ed5349SWolfram Sang if (client && get_device(&client->dev)) 165491ed5349SWolfram Sang return client; 165591ed5349SWolfram Sang return NULL; 165691ed5349SWolfram Sang } 165791ed5349SWolfram Sang EXPORT_SYMBOL(i2c_use_client); 165891ed5349SWolfram Sang 165991ed5349SWolfram Sang /** 166091ed5349SWolfram Sang * i2c_release_client - release a use of the i2c client structure 166191ed5349SWolfram Sang * @client: the client being no longer referenced 166291ed5349SWolfram Sang * 166391ed5349SWolfram Sang * Must be called when a user of a client is finished with it. 166491ed5349SWolfram Sang */ 166591ed5349SWolfram Sang void i2c_release_client(struct i2c_client *client) 166691ed5349SWolfram Sang { 166791ed5349SWolfram Sang if (client) 166891ed5349SWolfram Sang put_device(&client->dev); 166991ed5349SWolfram Sang } 167091ed5349SWolfram Sang EXPORT_SYMBOL(i2c_release_client); 167191ed5349SWolfram Sang 167291ed5349SWolfram Sang struct i2c_cmd_arg { 167391ed5349SWolfram Sang unsigned cmd; 167491ed5349SWolfram Sang void *arg; 167591ed5349SWolfram Sang }; 167691ed5349SWolfram Sang 167791ed5349SWolfram Sang static int i2c_cmd(struct device *dev, void *_arg) 167891ed5349SWolfram Sang { 167991ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 168091ed5349SWolfram Sang struct i2c_cmd_arg *arg = _arg; 168191ed5349SWolfram Sang struct i2c_driver *driver; 168291ed5349SWolfram Sang 168391ed5349SWolfram Sang if (!client || !client->dev.driver) 168491ed5349SWolfram Sang return 0; 168591ed5349SWolfram Sang 168691ed5349SWolfram Sang driver = to_i2c_driver(client->dev.driver); 168791ed5349SWolfram Sang if (driver->command) 168891ed5349SWolfram Sang driver->command(client, arg->cmd, arg->arg); 168991ed5349SWolfram Sang return 0; 169091ed5349SWolfram Sang } 169191ed5349SWolfram Sang 169291ed5349SWolfram Sang void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) 169391ed5349SWolfram Sang { 169491ed5349SWolfram Sang struct i2c_cmd_arg cmd_arg; 169591ed5349SWolfram Sang 169691ed5349SWolfram Sang cmd_arg.cmd = cmd; 169791ed5349SWolfram Sang cmd_arg.arg = arg; 169891ed5349SWolfram Sang device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); 169991ed5349SWolfram Sang } 170091ed5349SWolfram Sang EXPORT_SYMBOL(i2c_clients_command); 170191ed5349SWolfram Sang 170291ed5349SWolfram Sang static int __init i2c_init(void) 170391ed5349SWolfram Sang { 170491ed5349SWolfram Sang int retval; 170591ed5349SWolfram Sang 170691ed5349SWolfram Sang retval = of_alias_get_highest_id("i2c"); 170791ed5349SWolfram Sang 170891ed5349SWolfram Sang down_write(&__i2c_board_lock); 170991ed5349SWolfram Sang if (retval >= __i2c_first_dynamic_bus_num) 171091ed5349SWolfram Sang __i2c_first_dynamic_bus_num = retval + 1; 171191ed5349SWolfram Sang up_write(&__i2c_board_lock); 171291ed5349SWolfram Sang 171391ed5349SWolfram Sang retval = bus_register(&i2c_bus_type); 171491ed5349SWolfram Sang if (retval) 171591ed5349SWolfram Sang return retval; 171691ed5349SWolfram Sang 171791ed5349SWolfram Sang is_registered = true; 171891ed5349SWolfram Sang 171991ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 172091ed5349SWolfram Sang i2c_adapter_compat_class = class_compat_register("i2c-adapter"); 172191ed5349SWolfram Sang if (!i2c_adapter_compat_class) { 172291ed5349SWolfram Sang retval = -ENOMEM; 172391ed5349SWolfram Sang goto bus_err; 172491ed5349SWolfram Sang } 172591ed5349SWolfram Sang #endif 172691ed5349SWolfram Sang retval = i2c_add_driver(&dummy_driver); 172791ed5349SWolfram Sang if (retval) 172891ed5349SWolfram Sang goto class_err; 172991ed5349SWolfram Sang 173091ed5349SWolfram Sang if (IS_ENABLED(CONFIG_OF_DYNAMIC)) 173191ed5349SWolfram Sang WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier)); 173291ed5349SWolfram Sang if (IS_ENABLED(CONFIG_ACPI)) 173391ed5349SWolfram Sang WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier)); 173491ed5349SWolfram Sang 173591ed5349SWolfram Sang return 0; 173691ed5349SWolfram Sang 173791ed5349SWolfram Sang class_err: 173891ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 173991ed5349SWolfram Sang class_compat_unregister(i2c_adapter_compat_class); 174091ed5349SWolfram Sang bus_err: 174191ed5349SWolfram Sang #endif 174291ed5349SWolfram Sang is_registered = false; 174391ed5349SWolfram Sang bus_unregister(&i2c_bus_type); 174491ed5349SWolfram Sang return retval; 174591ed5349SWolfram Sang } 174691ed5349SWolfram Sang 174791ed5349SWolfram Sang static void __exit i2c_exit(void) 174891ed5349SWolfram Sang { 174991ed5349SWolfram Sang if (IS_ENABLED(CONFIG_ACPI)) 175091ed5349SWolfram Sang WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier)); 175191ed5349SWolfram Sang if (IS_ENABLED(CONFIG_OF_DYNAMIC)) 175291ed5349SWolfram Sang WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier)); 175391ed5349SWolfram Sang i2c_del_driver(&dummy_driver); 175491ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 175591ed5349SWolfram Sang class_compat_unregister(i2c_adapter_compat_class); 175691ed5349SWolfram Sang #endif 175791ed5349SWolfram Sang bus_unregister(&i2c_bus_type); 175891ed5349SWolfram Sang tracepoint_synchronize_unregister(); 175991ed5349SWolfram Sang } 176091ed5349SWolfram Sang 176191ed5349SWolfram Sang /* We must initialize early, because some subsystems register i2c drivers 176291ed5349SWolfram Sang * in subsys_initcall() code, but are linked (and initialized) before i2c. 176391ed5349SWolfram Sang */ 176491ed5349SWolfram Sang postcore_initcall(i2c_init); 176591ed5349SWolfram Sang module_exit(i2c_exit); 176691ed5349SWolfram Sang 176791ed5349SWolfram Sang /* ---------------------------------------------------- 176891ed5349SWolfram Sang * the functional interface to the i2c busses. 176991ed5349SWolfram Sang * ---------------------------------------------------- 177091ed5349SWolfram Sang */ 177191ed5349SWolfram Sang 177291ed5349SWolfram Sang /* Check if val is exceeding the quirk IFF quirk is non 0 */ 177391ed5349SWolfram Sang #define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk))) 177491ed5349SWolfram Sang 177591ed5349SWolfram Sang static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg) 177691ed5349SWolfram Sang { 177791ed5349SWolfram Sang dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n", 177891ed5349SWolfram Sang err_msg, msg->addr, msg->len, 177991ed5349SWolfram Sang msg->flags & I2C_M_RD ? "read" : "write"); 178091ed5349SWolfram Sang return -EOPNOTSUPP; 178191ed5349SWolfram Sang } 178291ed5349SWolfram Sang 178391ed5349SWolfram Sang static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) 178491ed5349SWolfram Sang { 178591ed5349SWolfram Sang const struct i2c_adapter_quirks *q = adap->quirks; 178691ed5349SWolfram Sang int max_num = q->max_num_msgs, i; 178791ed5349SWolfram Sang bool do_len_check = true; 178891ed5349SWolfram Sang 178991ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB) { 179091ed5349SWolfram Sang max_num = 2; 179191ed5349SWolfram Sang 179291ed5349SWolfram Sang /* special checks for combined messages */ 179391ed5349SWolfram Sang if (num == 2) { 179491ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD) 179591ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write"); 179691ed5349SWolfram Sang 179791ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD)) 179891ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read"); 179991ed5349SWolfram Sang 180091ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr) 180191ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr"); 180291ed5349SWolfram Sang 180391ed5349SWolfram Sang if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len)) 180491ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "msg too long"); 180591ed5349SWolfram Sang 180691ed5349SWolfram Sang if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len)) 180791ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[1], "msg too long"); 180891ed5349SWolfram Sang 180991ed5349SWolfram Sang do_len_check = false; 181091ed5349SWolfram Sang } 181191ed5349SWolfram Sang } 181291ed5349SWolfram Sang 181391ed5349SWolfram Sang if (i2c_quirk_exceeded(num, max_num)) 181491ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "too many messages"); 181591ed5349SWolfram Sang 181691ed5349SWolfram Sang for (i = 0; i < num; i++) { 181791ed5349SWolfram Sang u16 len = msgs[i].len; 181891ed5349SWolfram Sang 181991ed5349SWolfram Sang if (msgs[i].flags & I2C_M_RD) { 182091ed5349SWolfram Sang if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len)) 182191ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[i], "msg too long"); 182291ed5349SWolfram Sang } else { 182391ed5349SWolfram Sang if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len)) 182491ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[i], "msg too long"); 182591ed5349SWolfram Sang } 182691ed5349SWolfram Sang } 182791ed5349SWolfram Sang 182891ed5349SWolfram Sang return 0; 182991ed5349SWolfram Sang } 183091ed5349SWolfram Sang 183191ed5349SWolfram Sang /** 183291ed5349SWolfram Sang * __i2c_transfer - unlocked flavor of i2c_transfer 183391ed5349SWolfram Sang * @adap: Handle to I2C bus 183491ed5349SWolfram Sang * @msgs: One or more messages to execute before STOP is issued to 183591ed5349SWolfram Sang * terminate the operation; each message begins with a START. 183691ed5349SWolfram Sang * @num: Number of messages to be executed. 183791ed5349SWolfram Sang * 183891ed5349SWolfram Sang * Returns negative errno, else the number of messages executed. 183991ed5349SWolfram Sang * 184091ed5349SWolfram Sang * Adapter lock must be held when calling this function. No debug logging 184191ed5349SWolfram Sang * takes place. adap->algo->master_xfer existence isn't checked. 184291ed5349SWolfram Sang */ 184391ed5349SWolfram Sang int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) 184491ed5349SWolfram Sang { 184591ed5349SWolfram Sang unsigned long orig_jiffies; 184691ed5349SWolfram Sang int ret, try; 184791ed5349SWolfram Sang 184891ed5349SWolfram Sang if (adap->quirks && i2c_check_for_quirks(adap, msgs, num)) 184991ed5349SWolfram Sang return -EOPNOTSUPP; 185091ed5349SWolfram Sang 185191ed5349SWolfram Sang /* i2c_trace_msg gets enabled when tracepoint i2c_transfer gets 185291ed5349SWolfram Sang * enabled. This is an efficient way of keeping the for-loop from 185391ed5349SWolfram Sang * being executed when not needed. 185491ed5349SWolfram Sang */ 185591ed5349SWolfram Sang if (static_key_false(&i2c_trace_msg)) { 185691ed5349SWolfram Sang int i; 185791ed5349SWolfram Sang for (i = 0; i < num; i++) 185891ed5349SWolfram Sang if (msgs[i].flags & I2C_M_RD) 185991ed5349SWolfram Sang trace_i2c_read(adap, &msgs[i], i); 186091ed5349SWolfram Sang else 186191ed5349SWolfram Sang trace_i2c_write(adap, &msgs[i], i); 186291ed5349SWolfram Sang } 186391ed5349SWolfram Sang 186491ed5349SWolfram Sang /* Retry automatically on arbitration loss */ 186591ed5349SWolfram Sang orig_jiffies = jiffies; 186691ed5349SWolfram Sang for (ret = 0, try = 0; try <= adap->retries; try++) { 186791ed5349SWolfram Sang ret = adap->algo->master_xfer(adap, msgs, num); 186891ed5349SWolfram Sang if (ret != -EAGAIN) 186991ed5349SWolfram Sang break; 187091ed5349SWolfram Sang if (time_after(jiffies, orig_jiffies + adap->timeout)) 187191ed5349SWolfram Sang break; 187291ed5349SWolfram Sang } 187391ed5349SWolfram Sang 187491ed5349SWolfram Sang if (static_key_false(&i2c_trace_msg)) { 187591ed5349SWolfram Sang int i; 187691ed5349SWolfram Sang for (i = 0; i < ret; i++) 187791ed5349SWolfram Sang if (msgs[i].flags & I2C_M_RD) 187891ed5349SWolfram Sang trace_i2c_reply(adap, &msgs[i], i); 18794a3f7691SAhbong Chang trace_i2c_result(adap, num, ret); 188091ed5349SWolfram Sang } 188191ed5349SWolfram Sang 188291ed5349SWolfram Sang return ret; 188391ed5349SWolfram Sang } 188491ed5349SWolfram Sang EXPORT_SYMBOL(__i2c_transfer); 188591ed5349SWolfram Sang 188691ed5349SWolfram Sang /** 188791ed5349SWolfram Sang * i2c_transfer - execute a single or combined I2C message 188891ed5349SWolfram Sang * @adap: Handle to I2C bus 188991ed5349SWolfram Sang * @msgs: One or more messages to execute before STOP is issued to 189091ed5349SWolfram Sang * terminate the operation; each message begins with a START. 189191ed5349SWolfram Sang * @num: Number of messages to be executed. 189291ed5349SWolfram Sang * 189391ed5349SWolfram Sang * Returns negative errno, else the number of messages executed. 189491ed5349SWolfram Sang * 189591ed5349SWolfram Sang * Note that there is no requirement that each message be sent to 189691ed5349SWolfram Sang * the same slave address, although that is the most common model. 189791ed5349SWolfram Sang */ 189891ed5349SWolfram Sang int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) 189991ed5349SWolfram Sang { 190091ed5349SWolfram Sang int ret; 190191ed5349SWolfram Sang 190291ed5349SWolfram Sang /* REVISIT the fault reporting model here is weak: 190391ed5349SWolfram Sang * 190491ed5349SWolfram Sang * - When we get an error after receiving N bytes from a slave, 190591ed5349SWolfram Sang * there is no way to report "N". 190691ed5349SWolfram Sang * 190791ed5349SWolfram Sang * - When we get a NAK after transmitting N bytes to a slave, 190891ed5349SWolfram Sang * there is no way to report "N" ... or to let the master 190991ed5349SWolfram Sang * continue executing the rest of this combined message, if 191091ed5349SWolfram Sang * that's the appropriate response. 191191ed5349SWolfram Sang * 191291ed5349SWolfram Sang * - When for example "num" is two and we successfully complete 191391ed5349SWolfram Sang * the first message but get an error part way through the 191491ed5349SWolfram Sang * second, it's unclear whether that should be reported as 191591ed5349SWolfram Sang * one (discarding status on the second message) or errno 191691ed5349SWolfram Sang * (discarding status on the first one). 191791ed5349SWolfram Sang */ 191891ed5349SWolfram Sang 191991ed5349SWolfram Sang if (adap->algo->master_xfer) { 192091ed5349SWolfram Sang #ifdef DEBUG 192191ed5349SWolfram Sang for (ret = 0; ret < num; ret++) { 192291ed5349SWolfram Sang dev_dbg(&adap->dev, 192391ed5349SWolfram Sang "master_xfer[%d] %c, addr=0x%02x, len=%d%s\n", 192491ed5349SWolfram Sang ret, (msgs[ret].flags & I2C_M_RD) ? 'R' : 'W', 192591ed5349SWolfram Sang msgs[ret].addr, msgs[ret].len, 192691ed5349SWolfram Sang (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); 192791ed5349SWolfram Sang } 192891ed5349SWolfram Sang #endif 192991ed5349SWolfram Sang 193091ed5349SWolfram Sang if (in_atomic() || irqs_disabled()) { 193191ed5349SWolfram Sang ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT); 193291ed5349SWolfram Sang if (!ret) 193391ed5349SWolfram Sang /* I2C activity is ongoing. */ 193491ed5349SWolfram Sang return -EAGAIN; 193591ed5349SWolfram Sang } else { 193691ed5349SWolfram Sang i2c_lock_bus(adap, I2C_LOCK_SEGMENT); 193791ed5349SWolfram Sang } 193891ed5349SWolfram Sang 193991ed5349SWolfram Sang ret = __i2c_transfer(adap, msgs, num); 194091ed5349SWolfram Sang i2c_unlock_bus(adap, I2C_LOCK_SEGMENT); 194191ed5349SWolfram Sang 194291ed5349SWolfram Sang return ret; 194391ed5349SWolfram Sang } else { 194491ed5349SWolfram Sang dev_dbg(&adap->dev, "I2C level transfers not supported\n"); 194591ed5349SWolfram Sang return -EOPNOTSUPP; 194691ed5349SWolfram Sang } 194791ed5349SWolfram Sang } 194891ed5349SWolfram Sang EXPORT_SYMBOL(i2c_transfer); 194991ed5349SWolfram Sang 195091ed5349SWolfram Sang /** 19518a91732bSWolfram Sang * i2c_transfer_buffer_flags - issue a single I2C message transferring data 19528a91732bSWolfram Sang * to/from a buffer 195391ed5349SWolfram Sang * @client: Handle to slave device 19548a91732bSWolfram Sang * @buf: Where the data is stored 19558a91732bSWolfram Sang * @count: How many bytes to transfer, must be less than 64k since msg.len is u16 19568a91732bSWolfram Sang * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads 195791ed5349SWolfram Sang * 19588a91732bSWolfram Sang * Returns negative errno, or else the number of bytes transferred. 195991ed5349SWolfram Sang */ 19608a91732bSWolfram Sang int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf, 19618a91732bSWolfram Sang int count, u16 flags) 196291ed5349SWolfram Sang { 196391ed5349SWolfram Sang int ret; 19648a91732bSWolfram Sang struct i2c_msg msg = { 19658a91732bSWolfram Sang .addr = client->addr, 19668a91732bSWolfram Sang .flags = flags | (client->flags & I2C_M_TEN), 19678a91732bSWolfram Sang .len = count, 19688a91732bSWolfram Sang .buf = buf, 19698a91732bSWolfram Sang }; 197091ed5349SWolfram Sang 19718a91732bSWolfram Sang ret = i2c_transfer(client->adapter, &msg, 1); 197291ed5349SWolfram Sang 197391ed5349SWolfram Sang /* 19748a91732bSWolfram Sang * If everything went ok (i.e. 1 msg transferred), return #bytes 19758a91732bSWolfram Sang * transferred, else error code. 197691ed5349SWolfram Sang */ 197791ed5349SWolfram Sang return (ret == 1) ? count : ret; 197891ed5349SWolfram Sang } 19798a91732bSWolfram Sang EXPORT_SYMBOL(i2c_transfer_buffer_flags); 198091ed5349SWolfram Sang 1981dde67eb1SPeter Rosin /** 1982dde67eb1SPeter Rosin * i2c_get_device_id - get manufacturer, part id and die revision of a device 1983dde67eb1SPeter Rosin * @client: The device to query 1984dde67eb1SPeter Rosin * @id: The queried information 1985dde67eb1SPeter Rosin * 1986dde67eb1SPeter Rosin * Returns negative errno on error, zero on success. 1987dde67eb1SPeter Rosin */ 1988dde67eb1SPeter Rosin int i2c_get_device_id(const struct i2c_client *client, 1989dde67eb1SPeter Rosin struct i2c_device_identity *id) 1990dde67eb1SPeter Rosin { 1991dde67eb1SPeter Rosin struct i2c_adapter *adap = client->adapter; 1992dde67eb1SPeter Rosin union i2c_smbus_data raw_id; 1993dde67eb1SPeter Rosin int ret; 1994dde67eb1SPeter Rosin 1995dde67eb1SPeter Rosin if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) 1996dde67eb1SPeter Rosin return -EOPNOTSUPP; 1997dde67eb1SPeter Rosin 1998dde67eb1SPeter Rosin raw_id.block[0] = 3; 1999dde67eb1SPeter Rosin ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0, 2000dde67eb1SPeter Rosin I2C_SMBUS_READ, client->addr << 1, 2001dde67eb1SPeter Rosin I2C_SMBUS_I2C_BLOCK_DATA, &raw_id); 2002dde67eb1SPeter Rosin if (ret) 2003dde67eb1SPeter Rosin return ret; 2004dde67eb1SPeter Rosin 2005dde67eb1SPeter Rosin id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4); 2006dde67eb1SPeter Rosin id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3); 2007dde67eb1SPeter Rosin id->die_revision = raw_id.block[3] & 0x7; 2008dde67eb1SPeter Rosin return 0; 2009dde67eb1SPeter Rosin } 2010dde67eb1SPeter Rosin EXPORT_SYMBOL_GPL(i2c_get_device_id); 2011dde67eb1SPeter Rosin 201291ed5349SWolfram Sang /* ---------------------------------------------------- 201391ed5349SWolfram Sang * the i2c address scanning function 201491ed5349SWolfram Sang * Will not work for 10-bit addresses! 201591ed5349SWolfram Sang * ---------------------------------------------------- 201691ed5349SWolfram Sang */ 201791ed5349SWolfram Sang 201891ed5349SWolfram Sang /* 201991ed5349SWolfram Sang * Legacy default probe function, mostly relevant for SMBus. The default 202091ed5349SWolfram Sang * probe method is a quick write, but it is known to corrupt the 24RF08 202191ed5349SWolfram Sang * EEPROMs due to a state machine bug, and could also irreversibly 202291ed5349SWolfram Sang * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, 202391ed5349SWolfram Sang * we use a short byte read instead. Also, some bus drivers don't implement 202491ed5349SWolfram Sang * quick write, so we fallback to a byte read in that case too. 202591ed5349SWolfram Sang * On x86, there is another special case for FSC hardware monitoring chips, 202691ed5349SWolfram Sang * which want regular byte reads (address 0x73.) Fortunately, these are the 202791ed5349SWolfram Sang * only known chips using this I2C address on PC hardware. 202891ed5349SWolfram Sang * Returns 1 if probe succeeded, 0 if not. 202991ed5349SWolfram Sang */ 203091ed5349SWolfram Sang static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) 203191ed5349SWolfram Sang { 203291ed5349SWolfram Sang int err; 203391ed5349SWolfram Sang union i2c_smbus_data dummy; 203491ed5349SWolfram Sang 203591ed5349SWolfram Sang #ifdef CONFIG_X86 203691ed5349SWolfram Sang if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) 203791ed5349SWolfram Sang && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) 203891ed5349SWolfram Sang err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, 203991ed5349SWolfram Sang I2C_SMBUS_BYTE_DATA, &dummy); 204091ed5349SWolfram Sang else 204191ed5349SWolfram Sang #endif 204291ed5349SWolfram Sang if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) 204391ed5349SWolfram Sang && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) 204491ed5349SWolfram Sang err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, 204591ed5349SWolfram Sang I2C_SMBUS_QUICK, NULL); 204691ed5349SWolfram Sang else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) 204791ed5349SWolfram Sang err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, 204891ed5349SWolfram Sang I2C_SMBUS_BYTE, &dummy); 204991ed5349SWolfram Sang else { 205091ed5349SWolfram Sang dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", 205191ed5349SWolfram Sang addr); 205291ed5349SWolfram Sang err = -EOPNOTSUPP; 205391ed5349SWolfram Sang } 205491ed5349SWolfram Sang 205591ed5349SWolfram Sang return err >= 0; 205691ed5349SWolfram Sang } 205791ed5349SWolfram Sang 205891ed5349SWolfram Sang static int i2c_detect_address(struct i2c_client *temp_client, 205991ed5349SWolfram Sang struct i2c_driver *driver) 206091ed5349SWolfram Sang { 206191ed5349SWolfram Sang struct i2c_board_info info; 206291ed5349SWolfram Sang struct i2c_adapter *adapter = temp_client->adapter; 206391ed5349SWolfram Sang int addr = temp_client->addr; 206491ed5349SWolfram Sang int err; 206591ed5349SWolfram Sang 206691ed5349SWolfram Sang /* Make sure the address is valid */ 206791ed5349SWolfram Sang err = i2c_check_7bit_addr_validity_strict(addr); 206891ed5349SWolfram Sang if (err) { 206991ed5349SWolfram Sang dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", 207091ed5349SWolfram Sang addr); 207191ed5349SWolfram Sang return err; 207291ed5349SWolfram Sang } 207391ed5349SWolfram Sang 207491ed5349SWolfram Sang /* Skip if already in use (7 bit, no need to encode flags) */ 207591ed5349SWolfram Sang if (i2c_check_addr_busy(adapter, addr)) 207691ed5349SWolfram Sang return 0; 207791ed5349SWolfram Sang 207891ed5349SWolfram Sang /* Make sure there is something at this address */ 207991ed5349SWolfram Sang if (!i2c_default_probe(adapter, addr)) 208091ed5349SWolfram Sang return 0; 208191ed5349SWolfram Sang 208291ed5349SWolfram Sang /* Finally call the custom detection function */ 208391ed5349SWolfram Sang memset(&info, 0, sizeof(struct i2c_board_info)); 208491ed5349SWolfram Sang info.addr = addr; 208591ed5349SWolfram Sang err = driver->detect(temp_client, &info); 208691ed5349SWolfram Sang if (err) { 208791ed5349SWolfram Sang /* -ENODEV is returned if the detection fails. We catch it 208891ed5349SWolfram Sang here as this isn't an error. */ 208991ed5349SWolfram Sang return err == -ENODEV ? 0 : err; 209091ed5349SWolfram Sang } 209191ed5349SWolfram Sang 209291ed5349SWolfram Sang /* Consistency check */ 209391ed5349SWolfram Sang if (info.type[0] == '\0') { 209491ed5349SWolfram Sang dev_err(&adapter->dev, 209591ed5349SWolfram Sang "%s detection function provided no name for 0x%x\n", 209691ed5349SWolfram Sang driver->driver.name, addr); 209791ed5349SWolfram Sang } else { 209891ed5349SWolfram Sang struct i2c_client *client; 209991ed5349SWolfram Sang 210091ed5349SWolfram Sang /* Detection succeeded, instantiate the device */ 210191ed5349SWolfram Sang if (adapter->class & I2C_CLASS_DEPRECATED) 210291ed5349SWolfram Sang dev_warn(&adapter->dev, 210391ed5349SWolfram Sang "This adapter will soon drop class based instantiation of devices. " 210491ed5349SWolfram Sang "Please make sure client 0x%02x gets instantiated by other means. " 210591ed5349SWolfram Sang "Check 'Documentation/i2c/instantiating-devices' for details.\n", 210691ed5349SWolfram Sang info.addr); 210791ed5349SWolfram Sang 210891ed5349SWolfram Sang dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", 210991ed5349SWolfram Sang info.type, info.addr); 211091ed5349SWolfram Sang client = i2c_new_device(adapter, &info); 211191ed5349SWolfram Sang if (client) 211291ed5349SWolfram Sang list_add_tail(&client->detected, &driver->clients); 211391ed5349SWolfram Sang else 211491ed5349SWolfram Sang dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", 211591ed5349SWolfram Sang info.type, info.addr); 211691ed5349SWolfram Sang } 211791ed5349SWolfram Sang return 0; 211891ed5349SWolfram Sang } 211991ed5349SWolfram Sang 212091ed5349SWolfram Sang static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) 212191ed5349SWolfram Sang { 212291ed5349SWolfram Sang const unsigned short *address_list; 212391ed5349SWolfram Sang struct i2c_client *temp_client; 212491ed5349SWolfram Sang int i, err = 0; 212591ed5349SWolfram Sang int adap_id = i2c_adapter_id(adapter); 212691ed5349SWolfram Sang 212791ed5349SWolfram Sang address_list = driver->address_list; 212891ed5349SWolfram Sang if (!driver->detect || !address_list) 212991ed5349SWolfram Sang return 0; 213091ed5349SWolfram Sang 213191ed5349SWolfram Sang /* Warn that the adapter lost class based instantiation */ 213291ed5349SWolfram Sang if (adapter->class == I2C_CLASS_DEPRECATED) { 213391ed5349SWolfram Sang dev_dbg(&adapter->dev, 213491ed5349SWolfram Sang "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. " 213591ed5349SWolfram Sang "If you need it, check 'Documentation/i2c/instantiating-devices' for alternatives.\n", 213691ed5349SWolfram Sang driver->driver.name); 213791ed5349SWolfram Sang return 0; 213891ed5349SWolfram Sang } 213991ed5349SWolfram Sang 214091ed5349SWolfram Sang /* Stop here if the classes do not match */ 214191ed5349SWolfram Sang if (!(adapter->class & driver->class)) 214291ed5349SWolfram Sang return 0; 214391ed5349SWolfram Sang 214491ed5349SWolfram Sang /* Set up a temporary client to help detect callback */ 214591ed5349SWolfram Sang temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); 214691ed5349SWolfram Sang if (!temp_client) 214791ed5349SWolfram Sang return -ENOMEM; 214891ed5349SWolfram Sang temp_client->adapter = adapter; 214991ed5349SWolfram Sang 215091ed5349SWolfram Sang for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { 215191ed5349SWolfram Sang dev_dbg(&adapter->dev, 215291ed5349SWolfram Sang "found normal entry for adapter %d, addr 0x%02x\n", 215391ed5349SWolfram Sang adap_id, address_list[i]); 215491ed5349SWolfram Sang temp_client->addr = address_list[i]; 215591ed5349SWolfram Sang err = i2c_detect_address(temp_client, driver); 215691ed5349SWolfram Sang if (unlikely(err)) 215791ed5349SWolfram Sang break; 215891ed5349SWolfram Sang } 215991ed5349SWolfram Sang 216091ed5349SWolfram Sang kfree(temp_client); 216191ed5349SWolfram Sang return err; 216291ed5349SWolfram Sang } 216391ed5349SWolfram Sang 216491ed5349SWolfram Sang int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) 216591ed5349SWolfram Sang { 216691ed5349SWolfram Sang return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, 216791ed5349SWolfram Sang I2C_SMBUS_QUICK, NULL) >= 0; 216891ed5349SWolfram Sang } 216991ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); 217091ed5349SWolfram Sang 217191ed5349SWolfram Sang struct i2c_client * 217291ed5349SWolfram Sang i2c_new_probed_device(struct i2c_adapter *adap, 217391ed5349SWolfram Sang struct i2c_board_info *info, 217491ed5349SWolfram Sang unsigned short const *addr_list, 217591ed5349SWolfram Sang int (*probe)(struct i2c_adapter *, unsigned short addr)) 217691ed5349SWolfram Sang { 217791ed5349SWolfram Sang int i; 217891ed5349SWolfram Sang 217991ed5349SWolfram Sang if (!probe) 218091ed5349SWolfram Sang probe = i2c_default_probe; 218191ed5349SWolfram Sang 218291ed5349SWolfram Sang for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { 218391ed5349SWolfram Sang /* Check address validity */ 218491ed5349SWolfram Sang if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) { 218591ed5349SWolfram Sang dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n", 218691ed5349SWolfram Sang addr_list[i]); 218791ed5349SWolfram Sang continue; 218891ed5349SWolfram Sang } 218991ed5349SWolfram Sang 219091ed5349SWolfram Sang /* Check address availability (7 bit, no need to encode flags) */ 219191ed5349SWolfram Sang if (i2c_check_addr_busy(adap, addr_list[i])) { 219291ed5349SWolfram Sang dev_dbg(&adap->dev, 219391ed5349SWolfram Sang "Address 0x%02x already in use, not probing\n", 219491ed5349SWolfram Sang addr_list[i]); 219591ed5349SWolfram Sang continue; 219691ed5349SWolfram Sang } 219791ed5349SWolfram Sang 219891ed5349SWolfram Sang /* Test address responsiveness */ 219991ed5349SWolfram Sang if (probe(adap, addr_list[i])) 220091ed5349SWolfram Sang break; 220191ed5349SWolfram Sang } 220291ed5349SWolfram Sang 220391ed5349SWolfram Sang if (addr_list[i] == I2C_CLIENT_END) { 220491ed5349SWolfram Sang dev_dbg(&adap->dev, "Probing failed, no device found\n"); 220591ed5349SWolfram Sang return NULL; 220691ed5349SWolfram Sang } 220791ed5349SWolfram Sang 220891ed5349SWolfram Sang info->addr = addr_list[i]; 220991ed5349SWolfram Sang return i2c_new_device(adap, info); 221091ed5349SWolfram Sang } 221191ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_new_probed_device); 221291ed5349SWolfram Sang 221391ed5349SWolfram Sang struct i2c_adapter *i2c_get_adapter(int nr) 221491ed5349SWolfram Sang { 221591ed5349SWolfram Sang struct i2c_adapter *adapter; 221691ed5349SWolfram Sang 221791ed5349SWolfram Sang mutex_lock(&core_lock); 221891ed5349SWolfram Sang adapter = idr_find(&i2c_adapter_idr, nr); 221991ed5349SWolfram Sang if (!adapter) 222091ed5349SWolfram Sang goto exit; 222191ed5349SWolfram Sang 222291ed5349SWolfram Sang if (try_module_get(adapter->owner)) 222391ed5349SWolfram Sang get_device(&adapter->dev); 222491ed5349SWolfram Sang else 222591ed5349SWolfram Sang adapter = NULL; 222691ed5349SWolfram Sang 222791ed5349SWolfram Sang exit: 222891ed5349SWolfram Sang mutex_unlock(&core_lock); 222991ed5349SWolfram Sang return adapter; 223091ed5349SWolfram Sang } 223191ed5349SWolfram Sang EXPORT_SYMBOL(i2c_get_adapter); 223291ed5349SWolfram Sang 223391ed5349SWolfram Sang void i2c_put_adapter(struct i2c_adapter *adap) 223491ed5349SWolfram Sang { 223591ed5349SWolfram Sang if (!adap) 223691ed5349SWolfram Sang return; 223791ed5349SWolfram Sang 223891ed5349SWolfram Sang put_device(&adap->dev); 223991ed5349SWolfram Sang module_put(adap->owner); 224091ed5349SWolfram Sang } 224191ed5349SWolfram Sang EXPORT_SYMBOL(i2c_put_adapter); 224291ed5349SWolfram Sang 2243e94bc5d1SWolfram Sang /** 2244e94bc5d1SWolfram Sang * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg 2245e94bc5d1SWolfram Sang * @msg: the message to be checked 2246e94bc5d1SWolfram Sang * @threshold: the minimum number of bytes for which using DMA makes sense 2247e94bc5d1SWolfram Sang * 2248e94bc5d1SWolfram Sang * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO. 2249e94bc5d1SWolfram Sang * Or a valid pointer to be used with DMA. After use, release it by 2250e94bc5d1SWolfram Sang * calling i2c_release_dma_safe_msg_buf(). 2251e94bc5d1SWolfram Sang * 2252e94bc5d1SWolfram Sang * This function must only be called from process context! 2253e94bc5d1SWolfram Sang */ 2254e94bc5d1SWolfram Sang u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold) 2255e94bc5d1SWolfram Sang { 2256e94bc5d1SWolfram Sang if (msg->len < threshold) 2257e94bc5d1SWolfram Sang return NULL; 2258e94bc5d1SWolfram Sang 2259e94bc5d1SWolfram Sang if (msg->flags & I2C_M_DMA_SAFE) 2260e94bc5d1SWolfram Sang return msg->buf; 2261e94bc5d1SWolfram Sang 2262e94bc5d1SWolfram Sang pr_debug("using bounce buffer for addr=0x%02x, len=%d\n", 2263e94bc5d1SWolfram Sang msg->addr, msg->len); 2264e94bc5d1SWolfram Sang 2265e94bc5d1SWolfram Sang if (msg->flags & I2C_M_RD) 2266e94bc5d1SWolfram Sang return kzalloc(msg->len, GFP_KERNEL); 2267e94bc5d1SWolfram Sang else 2268e94bc5d1SWolfram Sang return kmemdup(msg->buf, msg->len, GFP_KERNEL); 2269e94bc5d1SWolfram Sang } 2270e94bc5d1SWolfram Sang EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf); 2271e94bc5d1SWolfram Sang 2272e94bc5d1SWolfram Sang /** 2273e94bc5d1SWolfram Sang * i2c_release_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg 2274e94bc5d1SWolfram Sang * @msg: the message to be synced with 2275e94bc5d1SWolfram Sang * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL. 2276e94bc5d1SWolfram Sang */ 2277e94bc5d1SWolfram Sang void i2c_release_dma_safe_msg_buf(struct i2c_msg *msg, u8 *buf) 2278e94bc5d1SWolfram Sang { 2279e94bc5d1SWolfram Sang if (!buf || buf == msg->buf) 2280e94bc5d1SWolfram Sang return; 2281e94bc5d1SWolfram Sang 2282e94bc5d1SWolfram Sang if (msg->flags & I2C_M_RD) 2283e94bc5d1SWolfram Sang memcpy(msg->buf, buf, msg->len); 2284e94bc5d1SWolfram Sang 2285e94bc5d1SWolfram Sang kfree(buf); 2286e94bc5d1SWolfram Sang } 2287e94bc5d1SWolfram Sang EXPORT_SYMBOL_GPL(i2c_release_dma_safe_msg_buf); 2288e94bc5d1SWolfram Sang 228991ed5349SWolfram Sang MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); 229091ed5349SWolfram Sang MODULE_DESCRIPTION("I2C-Bus main module"); 229191ed5349SWolfram Sang MODULE_LICENSE("GPL"); 2292