1c942fddfSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later 261e3d0f7SWolfram Sang /* 361e3d0f7SWolfram Sang * Linux I2C core 461e3d0f7SWolfram Sang * 561e3d0f7SWolfram Sang * Copyright (C) 1995-99 Simon G. Vogl 661e3d0f7SWolfram Sang * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> 761e3d0f7SWolfram Sang * Mux support by Rodolfo Giometti <giometti@enneenne.com> and 861e3d0f7SWolfram Sang * Michael Lawnick <michael.lawnick.ext@nsn.com> 961e3d0f7SWolfram Sang * 102f5a55c5SWolfram Sang * Copyright (C) 2013-2017 Wolfram Sang <wsa@kernel.org> 1191ed5349SWolfram Sang */ 1291ed5349SWolfram Sang 1391ed5349SWolfram Sang #define pr_fmt(fmt) "i2c-core: " fmt 1491ed5349SWolfram Sang 1591ed5349SWolfram Sang #include <dt-bindings/i2c/i2c.h> 1691ed5349SWolfram Sang #include <linux/acpi.h> 1791ed5349SWolfram Sang #include <linux/clk/clk-conf.h> 1891ed5349SWolfram Sang #include <linux/completion.h> 1991ed5349SWolfram Sang #include <linux/delay.h> 2091ed5349SWolfram Sang #include <linux/err.h> 2191ed5349SWolfram Sang #include <linux/errno.h> 2210c9ef04SPhil Reid #include <linux/gpio/consumer.h> 2391ed5349SWolfram Sang #include <linux/i2c.h> 24f8756c67SPhil Reid #include <linux/i2c-smbus.h> 2591ed5349SWolfram Sang #include <linux/idr.h> 2691ed5349SWolfram Sang #include <linux/init.h> 27b64210f2SDmitry Torokhov #include <linux/interrupt.h> 2891ed5349SWolfram Sang #include <linux/irqflags.h> 2991ed5349SWolfram Sang #include <linux/jump_label.h> 3091ed5349SWolfram Sang #include <linux/kernel.h> 3191ed5349SWolfram Sang #include <linux/module.h> 3291ed5349SWolfram Sang #include <linux/mutex.h> 3391ed5349SWolfram Sang #include <linux/of_device.h> 3491ed5349SWolfram Sang #include <linux/of.h> 3591ed5349SWolfram Sang #include <linux/of_irq.h> 3675820314SCodrin Ciubotariu #include <linux/pinctrl/consumer.h> 3791ed5349SWolfram Sang #include <linux/pm_domain.h> 3891ed5349SWolfram Sang #include <linux/pm_runtime.h> 3991ed5349SWolfram Sang #include <linux/pm_wakeirq.h> 4091ed5349SWolfram Sang #include <linux/property.h> 4191ed5349SWolfram Sang #include <linux/rwsem.h> 4291ed5349SWolfram Sang #include <linux/slab.h> 4391ed5349SWolfram Sang 4491ed5349SWolfram Sang #include "i2c-core.h" 4591ed5349SWolfram Sang 4691ed5349SWolfram Sang #define CREATE_TRACE_POINTS 4791ed5349SWolfram Sang #include <trace/events/i2c.h> 4891ed5349SWolfram Sang 4991ed5349SWolfram Sang #define I2C_ADDR_OFFSET_TEN_BIT 0xa000 5091ed5349SWolfram Sang #define I2C_ADDR_OFFSET_SLAVE 0x1000 5191ed5349SWolfram Sang 5291ed5349SWolfram Sang #define I2C_ADDR_7BITS_MAX 0x77 5391ed5349SWolfram Sang #define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1) 5491ed5349SWolfram Sang 55dde67eb1SPeter Rosin #define I2C_ADDR_DEVICE_ID 0x7c 56dde67eb1SPeter Rosin 5761e3d0f7SWolfram Sang /* 5861e3d0f7SWolfram Sang * core_lock protects i2c_adapter_idr, and guarantees that device detection, 590c36dd37SWolfram Sang * deletion of detected devices are serialized 6061e3d0f7SWolfram Sang */ 6191ed5349SWolfram Sang static DEFINE_MUTEX(core_lock); 6291ed5349SWolfram Sang static DEFINE_IDR(i2c_adapter_idr); 6391ed5349SWolfram Sang 6491ed5349SWolfram Sang static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); 6591ed5349SWolfram Sang 6650888b01SDavidlohr Bueso static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key); 6791ed5349SWolfram Sang static bool is_registered; 6891ed5349SWolfram Sang 6991ed5349SWolfram Sang int i2c_transfer_trace_reg(void) 7091ed5349SWolfram Sang { 7150888b01SDavidlohr Bueso static_branch_inc(&i2c_trace_msg_key); 7291ed5349SWolfram Sang return 0; 7391ed5349SWolfram Sang } 7491ed5349SWolfram Sang 7591ed5349SWolfram Sang void i2c_transfer_trace_unreg(void) 7691ed5349SWolfram Sang { 7750888b01SDavidlohr Bueso static_branch_dec(&i2c_trace_msg_key); 7891ed5349SWolfram Sang } 7991ed5349SWolfram Sang 803b4c747cSYicong Yang const char *i2c_freq_mode_string(u32 bus_freq_hz) 813b4c747cSYicong Yang { 823b4c747cSYicong Yang switch (bus_freq_hz) { 833b4c747cSYicong Yang case I2C_MAX_STANDARD_MODE_FREQ: 843b4c747cSYicong Yang return "Standard Mode (100 kHz)"; 853b4c747cSYicong Yang case I2C_MAX_FAST_MODE_FREQ: 863b4c747cSYicong Yang return "Fast Mode (400 kHz)"; 873b4c747cSYicong Yang case I2C_MAX_FAST_MODE_PLUS_FREQ: 883b4c747cSYicong Yang return "Fast Mode Plus (1.0 MHz)"; 893b4c747cSYicong Yang case I2C_MAX_TURBO_MODE_FREQ: 903b4c747cSYicong Yang return "Turbo Mode (1.4 MHz)"; 913b4c747cSYicong Yang case I2C_MAX_HIGH_SPEED_MODE_FREQ: 923b4c747cSYicong Yang return "High Speed Mode (3.4 MHz)"; 933b4c747cSYicong Yang case I2C_MAX_ULTRA_FAST_MODE_FREQ: 943b4c747cSYicong Yang return "Ultra Fast Mode (5.0 MHz)"; 953b4c747cSYicong Yang default: 963b4c747cSYicong Yang return "Unknown Mode"; 973b4c747cSYicong Yang } 983b4c747cSYicong Yang } 993b4c747cSYicong Yang EXPORT_SYMBOL_GPL(i2c_freq_mode_string); 1003b4c747cSYicong Yang 10191ed5349SWolfram Sang const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 10291ed5349SWolfram Sang const struct i2c_client *client) 10391ed5349SWolfram Sang { 10491ed5349SWolfram Sang if (!(id && client)) 10591ed5349SWolfram Sang return NULL; 10691ed5349SWolfram Sang 10791ed5349SWolfram Sang while (id->name[0]) { 10891ed5349SWolfram Sang if (strcmp(client->name, id->name) == 0) 10991ed5349SWolfram Sang return id; 11091ed5349SWolfram Sang id++; 11191ed5349SWolfram Sang } 11291ed5349SWolfram Sang return NULL; 11391ed5349SWolfram Sang } 11491ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_match_id); 11591ed5349SWolfram Sang 11691ed5349SWolfram Sang static int i2c_device_match(struct device *dev, struct device_driver *drv) 11791ed5349SWolfram Sang { 11891ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 11991ed5349SWolfram Sang struct i2c_driver *driver; 12091ed5349SWolfram Sang 12191ed5349SWolfram Sang 12291ed5349SWolfram Sang /* Attempt an OF style match */ 12391ed5349SWolfram Sang if (i2c_of_match_device(drv->of_match_table, client)) 12491ed5349SWolfram Sang return 1; 12591ed5349SWolfram Sang 12691ed5349SWolfram Sang /* Then ACPI style match */ 12791ed5349SWolfram Sang if (acpi_driver_match_device(dev, drv)) 12891ed5349SWolfram Sang return 1; 12991ed5349SWolfram Sang 13091ed5349SWolfram Sang driver = to_i2c_driver(drv); 13191ed5349SWolfram Sang 13291ed5349SWolfram Sang /* Finally an I2C match */ 13391ed5349SWolfram Sang if (i2c_match_id(driver->id_table, client)) 13491ed5349SWolfram Sang return 1; 13591ed5349SWolfram Sang 13691ed5349SWolfram Sang return 0; 13791ed5349SWolfram Sang } 13891ed5349SWolfram Sang 13991ed5349SWolfram Sang static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) 14091ed5349SWolfram Sang { 14191ed5349SWolfram Sang struct i2c_client *client = to_i2c_client(dev); 14291ed5349SWolfram Sang int rc; 14391ed5349SWolfram Sang 144af503716SJavier Martinez Canillas rc = of_device_uevent_modalias(dev, env); 145af503716SJavier Martinez Canillas if (rc != -ENODEV) 146af503716SJavier Martinez Canillas return rc; 147af503716SJavier Martinez Canillas 14891ed5349SWolfram Sang rc = acpi_device_uevent_modalias(dev, env); 14991ed5349SWolfram Sang if (rc != -ENODEV) 15091ed5349SWolfram Sang return rc; 15191ed5349SWolfram Sang 15291ed5349SWolfram Sang return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name); 15391ed5349SWolfram Sang } 15491ed5349SWolfram Sang 15591ed5349SWolfram Sang /* i2c bus recovery routines */ 15691ed5349SWolfram Sang static int get_scl_gpio_value(struct i2c_adapter *adap) 15791ed5349SWolfram Sang { 1583991c5c8SPhil Reid return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod); 15991ed5349SWolfram Sang } 16091ed5349SWolfram Sang 16191ed5349SWolfram Sang static void set_scl_gpio_value(struct i2c_adapter *adap, int val) 16291ed5349SWolfram Sang { 1633991c5c8SPhil Reid gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val); 16491ed5349SWolfram Sang } 16591ed5349SWolfram Sang 16691ed5349SWolfram Sang static int get_sda_gpio_value(struct i2c_adapter *adap) 16791ed5349SWolfram Sang { 1683991c5c8SPhil Reid return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod); 16991ed5349SWolfram Sang } 17091ed5349SWolfram Sang 1718092178fSWolfram Sang static void set_sda_gpio_value(struct i2c_adapter *adap, int val) 17291ed5349SWolfram Sang { 1738092178fSWolfram Sang gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val); 17491ed5349SWolfram Sang } 17591ed5349SWolfram Sang 1767ca5f6beSWolfram Sang static int i2c_generic_bus_free(struct i2c_adapter *adap) 1777ca5f6beSWolfram Sang { 1787ca5f6beSWolfram Sang struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; 1797ca5f6beSWolfram Sang int ret = -EOPNOTSUPP; 1807ca5f6beSWolfram Sang 1817ca5f6beSWolfram Sang if (bri->get_bus_free) 1827ca5f6beSWolfram Sang ret = bri->get_bus_free(adap); 1837ca5f6beSWolfram Sang else if (bri->get_sda) 1847ca5f6beSWolfram Sang ret = bri->get_sda(adap); 1857ca5f6beSWolfram Sang 1867ca5f6beSWolfram Sang if (ret < 0) 1877ca5f6beSWolfram Sang return ret; 1887ca5f6beSWolfram Sang 1897ca5f6beSWolfram Sang return ret ? 0 : -EBUSY; 1907ca5f6beSWolfram Sang } 1917ca5f6beSWolfram Sang 19291ed5349SWolfram Sang /* 19391ed5349SWolfram Sang * We are generating clock pulses. ndelay() determines durating of clk pulses. 19491ed5349SWolfram Sang * We will generate clock with rate 100 KHz and so duration of both clock levels 19591ed5349SWolfram Sang * is: delay in ns = (10^6 / 100) / 2 19691ed5349SWolfram Sang */ 19791ed5349SWolfram Sang #define RECOVERY_NDELAY 5000 19891ed5349SWolfram Sang #define RECOVERY_CLK_CNT 9 19991ed5349SWolfram Sang 200e1eb7d28SPhil Reid int i2c_generic_scl_recovery(struct i2c_adapter *adap) 20191ed5349SWolfram Sang { 20291ed5349SWolfram Sang struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; 203cf676908SLinus Torvalds int i = 0, scl = 1, ret = 0; 20491ed5349SWolfram Sang 20591ed5349SWolfram Sang if (bri->prepare_recovery) 20691ed5349SWolfram Sang bri->prepare_recovery(adap); 20775820314SCodrin Ciubotariu if (bri->pinctrl) 20875820314SCodrin Ciubotariu pinctrl_select_state(bri->pinctrl, bri->pins_gpio); 20991ed5349SWolfram Sang 210c4ae05b9SWolfram Sang /* 211c4ae05b9SWolfram Sang * If we can set SDA, we will always create a STOP to ensure additional 212c4ae05b9SWolfram Sang * pulses will do no harm. This is achieved by letting SDA follow SCL 213c4ae05b9SWolfram Sang * half a cycle later. Check the 'incomplete_write_byte' fault injector 214cf8ce8b8SRussell King * for details. Note that we must honour tsu:sto, 4us, but lets use 5us 215cf8ce8b8SRussell King * here for simplicity. 216c4ae05b9SWolfram Sang */ 217f7ff75e2SWolfram Sang bri->set_scl(adap, scl); 218cf8ce8b8SRussell King ndelay(RECOVERY_NDELAY); 21972b08fccSWolfram Sang if (bri->set_sda) 220c4ae05b9SWolfram Sang bri->set_sda(adap, scl); 221c4ae05b9SWolfram Sang ndelay(RECOVERY_NDELAY / 2); 22291ed5349SWolfram Sang 22391ed5349SWolfram Sang /* 22491ed5349SWolfram Sang * By this time SCL is high, as we need to give 9 falling-rising edges 22591ed5349SWolfram Sang */ 22691ed5349SWolfram Sang while (i++ < RECOVERY_CLK_CNT * 2) { 227f7ff75e2SWolfram Sang if (scl) { 22891ed5349SWolfram Sang /* SCL shouldn't be low here */ 22991ed5349SWolfram Sang if (!bri->get_scl(adap)) { 23091ed5349SWolfram Sang dev_err(&adap->dev, 23191ed5349SWolfram Sang "SCL is stuck low, exit recovery\n"); 23291ed5349SWolfram Sang ret = -EBUSY; 23391ed5349SWolfram Sang break; 23491ed5349SWolfram Sang } 23591ed5349SWolfram Sang } 23691ed5349SWolfram Sang 237f7ff75e2SWolfram Sang scl = !scl; 238f7ff75e2SWolfram Sang bri->set_scl(adap, scl); 239c4ae05b9SWolfram Sang /* Creating STOP again, see above */ 240cf8ce8b8SRussell King if (scl) { 241cf8ce8b8SRussell King /* Honour minimum tsu:sto */ 242cf8ce8b8SRussell King ndelay(RECOVERY_NDELAY); 243cf8ce8b8SRussell King } else { 244cf8ce8b8SRussell King /* Honour minimum tf and thd:dat */ 245abe41184SWolfram Sang ndelay(RECOVERY_NDELAY / 2); 246cf8ce8b8SRussell King } 247abe41184SWolfram Sang if (bri->set_sda) 248f7ff75e2SWolfram Sang bri->set_sda(adap, scl); 249abe41184SWolfram Sang ndelay(RECOVERY_NDELAY / 2); 2500b71026cSWolfram Sang 251f7ff75e2SWolfram Sang if (scl) { 2527ca5f6beSWolfram Sang ret = i2c_generic_bus_free(adap); 2530b71026cSWolfram Sang if (ret == 0) 2540b71026cSWolfram Sang break; 25591ed5349SWolfram Sang } 25691ed5349SWolfram Sang } 25791ed5349SWolfram Sang 2587ca5f6beSWolfram Sang /* If we can't check bus status, assume recovery worked */ 2597ca5f6beSWolfram Sang if (ret == -EOPNOTSUPP) 2607ca5f6beSWolfram Sang ret = 0; 2612806e6adSWolfram Sang 26291ed5349SWolfram Sang if (bri->unprepare_recovery) 26391ed5349SWolfram Sang bri->unprepare_recovery(adap); 26475820314SCodrin Ciubotariu if (bri->pinctrl) 26575820314SCodrin Ciubotariu pinctrl_select_state(bri->pinctrl, bri->pins_default); 26691ed5349SWolfram Sang 26791ed5349SWolfram Sang return ret; 26891ed5349SWolfram Sang } 26991ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery); 27091ed5349SWolfram Sang 27191ed5349SWolfram Sang int i2c_recover_bus(struct i2c_adapter *adap) 27291ed5349SWolfram Sang { 27391ed5349SWolfram Sang if (!adap->bus_recovery_info) 274c126f7c3SDmitry Osipenko return -EBUSY; 27591ed5349SWolfram Sang 27691ed5349SWolfram Sang dev_dbg(&adap->dev, "Trying i2c bus recovery\n"); 27791ed5349SWolfram Sang return adap->bus_recovery_info->recover_bus(adap); 27891ed5349SWolfram Sang } 27991ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_recover_bus); 28091ed5349SWolfram Sang 28175820314SCodrin Ciubotariu static void i2c_gpio_init_pinctrl_recovery(struct i2c_adapter *adap) 28275820314SCodrin Ciubotariu { 28375820314SCodrin Ciubotariu struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; 28475820314SCodrin Ciubotariu struct device *dev = &adap->dev; 28575820314SCodrin Ciubotariu struct pinctrl *p = bri->pinctrl; 28675820314SCodrin Ciubotariu 28775820314SCodrin Ciubotariu /* 28875820314SCodrin Ciubotariu * we can't change states without pinctrl, so remove the states if 28975820314SCodrin Ciubotariu * populated 29075820314SCodrin Ciubotariu */ 29175820314SCodrin Ciubotariu if (!p) { 29275820314SCodrin Ciubotariu bri->pins_default = NULL; 29375820314SCodrin Ciubotariu bri->pins_gpio = NULL; 29475820314SCodrin Ciubotariu return; 29575820314SCodrin Ciubotariu } 29675820314SCodrin Ciubotariu 29775820314SCodrin Ciubotariu if (!bri->pins_default) { 29875820314SCodrin Ciubotariu bri->pins_default = pinctrl_lookup_state(p, 29975820314SCodrin Ciubotariu PINCTRL_STATE_DEFAULT); 30075820314SCodrin Ciubotariu if (IS_ERR(bri->pins_default)) { 30175820314SCodrin Ciubotariu dev_dbg(dev, PINCTRL_STATE_DEFAULT " state not found for GPIO recovery\n"); 30275820314SCodrin Ciubotariu bri->pins_default = NULL; 30375820314SCodrin Ciubotariu } 30475820314SCodrin Ciubotariu } 30575820314SCodrin Ciubotariu if (!bri->pins_gpio) { 30675820314SCodrin Ciubotariu bri->pins_gpio = pinctrl_lookup_state(p, "gpio"); 30775820314SCodrin Ciubotariu if (IS_ERR(bri->pins_gpio)) 30875820314SCodrin Ciubotariu bri->pins_gpio = pinctrl_lookup_state(p, "recovery"); 30975820314SCodrin Ciubotariu 31075820314SCodrin Ciubotariu if (IS_ERR(bri->pins_gpio)) { 31175820314SCodrin Ciubotariu dev_dbg(dev, "no gpio or recovery state found for GPIO recovery\n"); 31275820314SCodrin Ciubotariu bri->pins_gpio = NULL; 31375820314SCodrin Ciubotariu } 31475820314SCodrin Ciubotariu } 31575820314SCodrin Ciubotariu 31675820314SCodrin Ciubotariu /* for pinctrl state changes, we need all the information */ 31775820314SCodrin Ciubotariu if (bri->pins_default && bri->pins_gpio) { 31875820314SCodrin Ciubotariu dev_info(dev, "using pinctrl states for GPIO recovery"); 31975820314SCodrin Ciubotariu } else { 32075820314SCodrin Ciubotariu bri->pinctrl = NULL; 32175820314SCodrin Ciubotariu bri->pins_default = NULL; 32275820314SCodrin Ciubotariu bri->pins_gpio = NULL; 32375820314SCodrin Ciubotariu } 32475820314SCodrin Ciubotariu } 32575820314SCodrin Ciubotariu 32675820314SCodrin Ciubotariu static int i2c_gpio_init_generic_recovery(struct i2c_adapter *adap) 32775820314SCodrin Ciubotariu { 32875820314SCodrin Ciubotariu struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; 32975820314SCodrin Ciubotariu struct device *dev = &adap->dev; 33075820314SCodrin Ciubotariu struct gpio_desc *gpiod; 33175820314SCodrin Ciubotariu int ret = 0; 33275820314SCodrin Ciubotariu 33375820314SCodrin Ciubotariu /* 33475820314SCodrin Ciubotariu * don't touch the recovery information if the driver is not using 33575820314SCodrin Ciubotariu * generic SCL recovery 33675820314SCodrin Ciubotariu */ 33775820314SCodrin Ciubotariu if (bri->recover_bus && bri->recover_bus != i2c_generic_scl_recovery) 33875820314SCodrin Ciubotariu return 0; 33975820314SCodrin Ciubotariu 34075820314SCodrin Ciubotariu /* 34175820314SCodrin Ciubotariu * pins might be taken as GPIO, so we should inform pinctrl about 34275820314SCodrin Ciubotariu * this and move the state to GPIO 34375820314SCodrin Ciubotariu */ 34475820314SCodrin Ciubotariu if (bri->pinctrl) 34575820314SCodrin Ciubotariu pinctrl_select_state(bri->pinctrl, bri->pins_gpio); 34675820314SCodrin Ciubotariu 34775820314SCodrin Ciubotariu /* 34875820314SCodrin Ciubotariu * if there is incomplete or no recovery information, see if generic 34975820314SCodrin Ciubotariu * GPIO recovery is available 35075820314SCodrin Ciubotariu */ 35175820314SCodrin Ciubotariu if (!bri->scl_gpiod) { 35275820314SCodrin Ciubotariu gpiod = devm_gpiod_get(dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN); 35375820314SCodrin Ciubotariu if (PTR_ERR(gpiod) == -EPROBE_DEFER) { 35475820314SCodrin Ciubotariu ret = -EPROBE_DEFER; 35575820314SCodrin Ciubotariu goto cleanup_pinctrl_state; 35675820314SCodrin Ciubotariu } 35775820314SCodrin Ciubotariu if (!IS_ERR(gpiod)) { 35875820314SCodrin Ciubotariu bri->scl_gpiod = gpiod; 35975820314SCodrin Ciubotariu bri->recover_bus = i2c_generic_scl_recovery; 36075820314SCodrin Ciubotariu dev_info(dev, "using generic GPIOs for recovery\n"); 36175820314SCodrin Ciubotariu } 36275820314SCodrin Ciubotariu } 36375820314SCodrin Ciubotariu 36475820314SCodrin Ciubotariu /* SDA GPIOD line is optional, so we care about DEFER only */ 36575820314SCodrin Ciubotariu if (!bri->sda_gpiod) { 36675820314SCodrin Ciubotariu /* 36775820314SCodrin Ciubotariu * We have SCL. Pull SCL low and wait a bit so that SDA glitches 36875820314SCodrin Ciubotariu * have no effect. 36975820314SCodrin Ciubotariu */ 37075820314SCodrin Ciubotariu gpiod_direction_output(bri->scl_gpiod, 0); 37175820314SCodrin Ciubotariu udelay(10); 37275820314SCodrin Ciubotariu gpiod = devm_gpiod_get(dev, "sda", GPIOD_IN); 37375820314SCodrin Ciubotariu 37475820314SCodrin Ciubotariu /* Wait a bit in case of a SDA glitch, and then release SCL. */ 37575820314SCodrin Ciubotariu udelay(10); 37675820314SCodrin Ciubotariu gpiod_direction_output(bri->scl_gpiod, 1); 37775820314SCodrin Ciubotariu 37875820314SCodrin Ciubotariu if (PTR_ERR(gpiod) == -EPROBE_DEFER) { 37975820314SCodrin Ciubotariu ret = -EPROBE_DEFER; 38075820314SCodrin Ciubotariu goto cleanup_pinctrl_state; 38175820314SCodrin Ciubotariu } 38275820314SCodrin Ciubotariu if (!IS_ERR(gpiod)) 38375820314SCodrin Ciubotariu bri->sda_gpiod = gpiod; 38475820314SCodrin Ciubotariu } 38575820314SCodrin Ciubotariu 38675820314SCodrin Ciubotariu cleanup_pinctrl_state: 38775820314SCodrin Ciubotariu /* change the state of the pins back to their default state */ 38875820314SCodrin Ciubotariu if (bri->pinctrl) 38975820314SCodrin Ciubotariu pinctrl_select_state(bri->pinctrl, bri->pins_default); 39075820314SCodrin Ciubotariu 39175820314SCodrin Ciubotariu return ret; 39275820314SCodrin Ciubotariu } 39375820314SCodrin Ciubotariu 39475820314SCodrin Ciubotariu static int i2c_gpio_init_recovery(struct i2c_adapter *adap) 39575820314SCodrin Ciubotariu { 39675820314SCodrin Ciubotariu i2c_gpio_init_pinctrl_recovery(adap); 39775820314SCodrin Ciubotariu return i2c_gpio_init_generic_recovery(adap); 39875820314SCodrin Ciubotariu } 39975820314SCodrin Ciubotariu 40023a698feSCodrin Ciubotariu static int i2c_init_recovery(struct i2c_adapter *adap) 40191ed5349SWolfram Sang { 40291ed5349SWolfram Sang struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; 403cb3c66afSAndy Shevchenko bool is_error_level = true; 404cb3c66afSAndy Shevchenko char *err_str; 40591ed5349SWolfram Sang 40691ed5349SWolfram Sang if (!bri) 40723a698feSCodrin Ciubotariu return 0; 40891ed5349SWolfram Sang 40923a698feSCodrin Ciubotariu if (i2c_gpio_init_recovery(adap) == -EPROBE_DEFER) 41023a698feSCodrin Ciubotariu return -EPROBE_DEFER; 41175820314SCodrin Ciubotariu 41291ed5349SWolfram Sang if (!bri->recover_bus) { 413e409a6a3SWolfram Sang err_str = "no suitable method provided"; 414cb3c66afSAndy Shevchenko is_error_level = false; 41591ed5349SWolfram Sang goto err; 41691ed5349SWolfram Sang } 41791ed5349SWolfram Sang 4183991c5c8SPhil Reid if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) { 41991ed5349SWolfram Sang bri->get_scl = get_scl_gpio_value; 42091ed5349SWolfram Sang bri->set_scl = set_scl_gpio_value; 4218092178fSWolfram Sang if (bri->sda_gpiod) { 4223991c5c8SPhil Reid bri->get_sda = get_sda_gpio_value; 4238092178fSWolfram Sang /* FIXME: add proper flag instead of '0' once available */ 4248092178fSWolfram Sang if (gpiod_get_direction(bri->sda_gpiod) == 0) 4258092178fSWolfram Sang bri->set_sda = set_sda_gpio_value; 4268092178fSWolfram Sang } 42723a698feSCodrin Ciubotariu } else if (bri->recover_bus == i2c_generic_scl_recovery) { 42891ed5349SWolfram Sang /* Generic SCL recovery */ 42991ed5349SWolfram Sang if (!bri->set_scl || !bri->get_scl) { 43091ed5349SWolfram Sang err_str = "no {get|set}_scl() found"; 43191ed5349SWolfram Sang goto err; 43291ed5349SWolfram Sang } 433ffc59c49SWolfram Sang if (!bri->set_sda && !bri->get_sda) { 434ffc59c49SWolfram Sang err_str = "either get_sda() or set_sda() needed"; 435ffc59c49SWolfram Sang goto err; 436ffc59c49SWolfram Sang } 43791ed5349SWolfram Sang } 43891ed5349SWolfram Sang 43923a698feSCodrin Ciubotariu return 0; 44091ed5349SWolfram Sang err: 441cb3c66afSAndy Shevchenko if (is_error_level) 442cb3c66afSAndy Shevchenko dev_err(&adap->dev, "Not using recovery: %s\n", err_str); 443cb3c66afSAndy Shevchenko else 444cb3c66afSAndy Shevchenko dev_dbg(&adap->dev, "Not using recovery: %s\n", err_str); 44591ed5349SWolfram Sang adap->bus_recovery_info = NULL; 44623a698feSCodrin Ciubotariu 44723a698feSCodrin Ciubotariu return -EINVAL; 44891ed5349SWolfram Sang } 44991ed5349SWolfram Sang 45091ed5349SWolfram Sang static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client) 45191ed5349SWolfram Sang { 45291ed5349SWolfram Sang struct i2c_adapter *adap = client->adapter; 45391ed5349SWolfram Sang unsigned int irq; 45491ed5349SWolfram Sang 45591ed5349SWolfram Sang if (!adap->host_notify_domain) 45691ed5349SWolfram Sang return -ENXIO; 45791ed5349SWolfram Sang 45891ed5349SWolfram Sang if (client->flags & I2C_CLIENT_TEN) 45991ed5349SWolfram Sang return -EINVAL; 46091ed5349SWolfram Sang 461b9bb3fdfSCharles Keepax irq = irq_create_mapping(adap->host_notify_domain, client->addr); 46291ed5349SWolfram Sang 46391ed5349SWolfram Sang return irq > 0 ? irq : -ENXIO; 46491ed5349SWolfram Sang } 46591ed5349SWolfram Sang 46691ed5349SWolfram Sang static int i2c_device_probe(struct device *dev) 46791ed5349SWolfram Sang { 46891ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 4695a7b95fbSBibby Hsieh struct i2c_adapter *adap; 47091ed5349SWolfram Sang struct i2c_driver *driver; 47191ed5349SWolfram Sang int status; 47291ed5349SWolfram Sang 47391ed5349SWolfram Sang if (!client) 47491ed5349SWolfram Sang return 0; 47591ed5349SWolfram Sang 4765a7b95fbSBibby Hsieh adap = client->adapter; 4776e76cb7dSCharles Keepax client->irq = client->init_irq; 4786e76cb7dSCharles Keepax 4790c2a3493SWolfram Sang if (!client->irq) { 48091ed5349SWolfram Sang int irq = -ENOENT; 48191ed5349SWolfram Sang 48291ed5349SWolfram Sang if (client->flags & I2C_CLIENT_HOST_NOTIFY) { 48391ed5349SWolfram Sang dev_dbg(dev, "Using Host Notify IRQ\n"); 48472bfcee1SJarkko Nikula /* Keep adapter active when Host Notify is required */ 48572bfcee1SJarkko Nikula pm_runtime_get_sync(&client->adapter->dev); 48691ed5349SWolfram Sang irq = i2c_smbus_host_notify_to_irq(client); 48791ed5349SWolfram Sang } else if (dev->of_node) { 48891ed5349SWolfram Sang irq = of_irq_get_byname(dev->of_node, "irq"); 48991ed5349SWolfram Sang if (irq == -EINVAL || irq == -ENODATA) 49091ed5349SWolfram Sang irq = of_irq_get(dev->of_node, 0); 49191ed5349SWolfram Sang } else if (ACPI_COMPANION(dev)) { 49216c9db1dSCharles Keepax irq = i2c_acpi_get_irq(client); 49391ed5349SWolfram Sang } 4943c3dd56fSAlain Volmat if (irq == -EPROBE_DEFER) { 4953c3dd56fSAlain Volmat status = irq; 4963c3dd56fSAlain Volmat goto put_sync_adapter; 4973c3dd56fSAlain Volmat } 49891ed5349SWolfram Sang 49991ed5349SWolfram Sang if (irq < 0) 50091ed5349SWolfram Sang irq = 0; 50191ed5349SWolfram Sang 50291ed5349SWolfram Sang client->irq = irq; 50391ed5349SWolfram Sang } 50491ed5349SWolfram Sang 5050c2a3493SWolfram Sang driver = to_i2c_driver(dev->driver); 5060c2a3493SWolfram Sang 50791ed5349SWolfram Sang /* 508f4b17a14SJavier Martinez Canillas * An I2C ID table is not mandatory, if and only if, a suitable OF 509f4b17a14SJavier Martinez Canillas * or ACPI ID table is supplied for the probing device. 51091ed5349SWolfram Sang */ 51191ed5349SWolfram Sang if (!driver->id_table && 512e3cb82c6SAndy Shevchenko !acpi_driver_match_device(dev, dev->driver) && 5133c3dd56fSAlain Volmat !i2c_of_match_device(dev->driver->of_match_table, client)) { 5143c3dd56fSAlain Volmat status = -ENODEV; 5153c3dd56fSAlain Volmat goto put_sync_adapter; 5163c3dd56fSAlain Volmat } 51791ed5349SWolfram Sang 51891ed5349SWolfram Sang if (client->flags & I2C_CLIENT_WAKE) { 5193e99834cSAndy Shevchenko int wakeirq; 52091ed5349SWolfram Sang 52191ed5349SWolfram Sang wakeirq = of_irq_get_byname(dev->of_node, "wakeup"); 5223c3dd56fSAlain Volmat if (wakeirq == -EPROBE_DEFER) { 5233c3dd56fSAlain Volmat status = wakeirq; 5243c3dd56fSAlain Volmat goto put_sync_adapter; 5253c3dd56fSAlain Volmat } 52691ed5349SWolfram Sang 52791ed5349SWolfram Sang device_init_wakeup(&client->dev, true); 52891ed5349SWolfram Sang 52991ed5349SWolfram Sang if (wakeirq > 0 && wakeirq != client->irq) 53091ed5349SWolfram Sang status = dev_pm_set_dedicated_wake_irq(dev, wakeirq); 53191ed5349SWolfram Sang else if (client->irq > 0) 53291ed5349SWolfram Sang status = dev_pm_set_wake_irq(dev, client->irq); 53391ed5349SWolfram Sang else 53491ed5349SWolfram Sang status = 0; 53591ed5349SWolfram Sang 53691ed5349SWolfram Sang if (status) 53791ed5349SWolfram Sang dev_warn(&client->dev, "failed to set up wakeup irq\n"); 53891ed5349SWolfram Sang } 53991ed5349SWolfram Sang 54091ed5349SWolfram Sang dev_dbg(dev, "probe\n"); 54191ed5349SWolfram Sang 5425a7b95fbSBibby Hsieh if (adap->bus_regulator) { 5435a7b95fbSBibby Hsieh status = regulator_enable(adap->bus_regulator); 5445a7b95fbSBibby Hsieh if (status < 0) { 5455a7b95fbSBibby Hsieh dev_err(&adap->dev, "Failed to enable bus regulator\n"); 5465a7b95fbSBibby Hsieh goto err_clear_wakeup_irq; 5475a7b95fbSBibby Hsieh } 5485a7b95fbSBibby Hsieh } 5495a7b95fbSBibby Hsieh 55091ed5349SWolfram Sang status = of_clk_set_defaults(dev->of_node, false); 55191ed5349SWolfram Sang if (status < 0) 55291ed5349SWolfram Sang goto err_clear_wakeup_irq; 55391ed5349SWolfram Sang 554b18c1ad6SSakari Ailus status = dev_pm_domain_attach(&client->dev, 555b18c1ad6SSakari Ailus !i2c_acpi_waive_d0_probe(dev)); 556e6a20b6cSUlf Hansson if (status) 55791ed5349SWolfram Sang goto err_clear_wakeup_irq; 55891ed5349SWolfram Sang 5595b547582SDmitry Torokhov client->devres_group_id = devres_open_group(&client->dev, NULL, 5605b547582SDmitry Torokhov GFP_KERNEL); 5615b547582SDmitry Torokhov if (!client->devres_group_id) { 5625b547582SDmitry Torokhov status = -ENOMEM; 5635b547582SDmitry Torokhov goto err_detach_pm_domain; 5645b547582SDmitry Torokhov } 5655b547582SDmitry Torokhov 56691ed5349SWolfram Sang /* 56791ed5349SWolfram Sang * When there are no more users of probe(), 56891ed5349SWolfram Sang * rename probe_new to probe. 56991ed5349SWolfram Sang */ 57091ed5349SWolfram Sang if (driver->probe_new) 57191ed5349SWolfram Sang status = driver->probe_new(client); 57291ed5349SWolfram Sang else if (driver->probe) 57391ed5349SWolfram Sang status = driver->probe(client, 57491ed5349SWolfram Sang i2c_match_id(driver->id_table, client)); 57591ed5349SWolfram Sang else 57691ed5349SWolfram Sang status = -EINVAL; 57791ed5349SWolfram Sang 5785b547582SDmitry Torokhov /* 5795b547582SDmitry Torokhov * Note that we are not closing the devres group opened above so 5805b547582SDmitry Torokhov * even resources that were attached to the device after probe is 5815b547582SDmitry Torokhov * run are released when i2c_device_remove() is executed. This is 5825b547582SDmitry Torokhov * needed as some drivers would allocate additional resources, 5835b547582SDmitry Torokhov * for example when updating firmware. 5845b547582SDmitry Torokhov */ 5855b547582SDmitry Torokhov 58691ed5349SWolfram Sang if (status) 5875b547582SDmitry Torokhov goto err_release_driver_resources; 58891ed5349SWolfram Sang 58991ed5349SWolfram Sang return 0; 59091ed5349SWolfram Sang 5915b547582SDmitry Torokhov err_release_driver_resources: 5925b547582SDmitry Torokhov devres_release_group(&client->dev, client->devres_group_id); 59391ed5349SWolfram Sang err_detach_pm_domain: 594b18c1ad6SSakari Ailus dev_pm_domain_detach(&client->dev, !i2c_acpi_waive_d0_probe(dev)); 59591ed5349SWolfram Sang err_clear_wakeup_irq: 59691ed5349SWolfram Sang dev_pm_clear_wake_irq(&client->dev); 59791ed5349SWolfram Sang device_init_wakeup(&client->dev, false); 5983c3dd56fSAlain Volmat put_sync_adapter: 5993c3dd56fSAlain Volmat if (client->flags & I2C_CLIENT_HOST_NOTIFY) 6003c3dd56fSAlain Volmat pm_runtime_put_sync(&client->adapter->dev); 6013c3dd56fSAlain Volmat 60291ed5349SWolfram Sang return status; 60391ed5349SWolfram Sang } 60491ed5349SWolfram Sang 605fc7a6209SUwe Kleine-König static void i2c_device_remove(struct device *dev) 60691ed5349SWolfram Sang { 6074e970a0aSUwe Kleine-König struct i2c_client *client = to_i2c_client(dev); 6085a7b95fbSBibby Hsieh struct i2c_adapter *adap; 60991ed5349SWolfram Sang struct i2c_driver *driver; 61091ed5349SWolfram Sang 6115a7b95fbSBibby Hsieh adap = client->adapter; 61291ed5349SWolfram Sang driver = to_i2c_driver(dev->driver); 61391ed5349SWolfram Sang if (driver->remove) { 61471637c62SUwe Kleine-König int status; 61571637c62SUwe Kleine-König 61691ed5349SWolfram Sang dev_dbg(dev, "remove\n"); 61771637c62SUwe Kleine-König 61891ed5349SWolfram Sang status = driver->remove(client); 61971637c62SUwe Kleine-König if (status) 62071637c62SUwe Kleine-König dev_warn(dev, "remove failed (%pe), will be ignored\n", ERR_PTR(status)); 62191ed5349SWolfram Sang } 62291ed5349SWolfram Sang 6235b547582SDmitry Torokhov devres_release_group(&client->dev, client->devres_group_id); 6245b547582SDmitry Torokhov 625b18c1ad6SSakari Ailus dev_pm_domain_detach(&client->dev, !i2c_acpi_waive_d0_probe(dev)); 6265a7b95fbSBibby Hsieh if (!pm_runtime_status_suspended(&client->dev) && adap->bus_regulator) 6275a7b95fbSBibby Hsieh regulator_disable(adap->bus_regulator); 62891ed5349SWolfram Sang 62991ed5349SWolfram Sang dev_pm_clear_wake_irq(&client->dev); 63091ed5349SWolfram Sang device_init_wakeup(&client->dev, false); 63191ed5349SWolfram Sang 6326e76cb7dSCharles Keepax client->irq = 0; 63372bfcee1SJarkko Nikula if (client->flags & I2C_CLIENT_HOST_NOTIFY) 63472bfcee1SJarkko Nikula pm_runtime_put(&client->adapter->dev); 63591ed5349SWolfram Sang } 63691ed5349SWolfram Sang 6375a7b95fbSBibby Hsieh #ifdef CONFIG_PM_SLEEP 6385a7b95fbSBibby Hsieh static int i2c_resume_early(struct device *dev) 6395a7b95fbSBibby Hsieh { 6405a7b95fbSBibby Hsieh struct i2c_client *client = i2c_verify_client(dev); 6415a7b95fbSBibby Hsieh int err; 6425a7b95fbSBibby Hsieh 6435a7b95fbSBibby Hsieh if (!client) 6445a7b95fbSBibby Hsieh return 0; 6455a7b95fbSBibby Hsieh 6465a7b95fbSBibby Hsieh if (pm_runtime_status_suspended(&client->dev) && 6475a7b95fbSBibby Hsieh client->adapter->bus_regulator) { 6485a7b95fbSBibby Hsieh err = regulator_enable(client->adapter->bus_regulator); 6495a7b95fbSBibby Hsieh if (err) 6505a7b95fbSBibby Hsieh return err; 6515a7b95fbSBibby Hsieh } 6525a7b95fbSBibby Hsieh 6535a7b95fbSBibby Hsieh return pm_generic_resume_early(&client->dev); 6545a7b95fbSBibby Hsieh } 6555a7b95fbSBibby Hsieh 6565a7b95fbSBibby Hsieh static int i2c_suspend_late(struct device *dev) 6575a7b95fbSBibby Hsieh { 6585a7b95fbSBibby Hsieh struct i2c_client *client = i2c_verify_client(dev); 6595a7b95fbSBibby Hsieh int err; 6605a7b95fbSBibby Hsieh 6615a7b95fbSBibby Hsieh if (!client) 6625a7b95fbSBibby Hsieh return 0; 6635a7b95fbSBibby Hsieh 6645a7b95fbSBibby Hsieh err = pm_generic_suspend_late(&client->dev); 6655a7b95fbSBibby Hsieh if (err) 6665a7b95fbSBibby Hsieh return err; 6675a7b95fbSBibby Hsieh 6685a7b95fbSBibby Hsieh if (!pm_runtime_status_suspended(&client->dev) && 6695a7b95fbSBibby Hsieh client->adapter->bus_regulator) 6705a7b95fbSBibby Hsieh return regulator_disable(client->adapter->bus_regulator); 6715a7b95fbSBibby Hsieh 6725a7b95fbSBibby Hsieh return 0; 6735a7b95fbSBibby Hsieh } 6745a7b95fbSBibby Hsieh #endif 6755a7b95fbSBibby Hsieh 6765a7b95fbSBibby Hsieh #ifdef CONFIG_PM 6775a7b95fbSBibby Hsieh static int i2c_runtime_resume(struct device *dev) 6785a7b95fbSBibby Hsieh { 6795a7b95fbSBibby Hsieh struct i2c_client *client = i2c_verify_client(dev); 6805a7b95fbSBibby Hsieh int err; 6815a7b95fbSBibby Hsieh 6825a7b95fbSBibby Hsieh if (!client) 6835a7b95fbSBibby Hsieh return 0; 6845a7b95fbSBibby Hsieh 6855a7b95fbSBibby Hsieh if (client->adapter->bus_regulator) { 6865a7b95fbSBibby Hsieh err = regulator_enable(client->adapter->bus_regulator); 6875a7b95fbSBibby Hsieh if (err) 6885a7b95fbSBibby Hsieh return err; 6895a7b95fbSBibby Hsieh } 6905a7b95fbSBibby Hsieh 6915a7b95fbSBibby Hsieh return pm_generic_runtime_resume(&client->dev); 6925a7b95fbSBibby Hsieh } 6935a7b95fbSBibby Hsieh 6945a7b95fbSBibby Hsieh static int i2c_runtime_suspend(struct device *dev) 6955a7b95fbSBibby Hsieh { 6965a7b95fbSBibby Hsieh struct i2c_client *client = i2c_verify_client(dev); 6975a7b95fbSBibby Hsieh int err; 6985a7b95fbSBibby Hsieh 6995a7b95fbSBibby Hsieh if (!client) 7005a7b95fbSBibby Hsieh return 0; 7015a7b95fbSBibby Hsieh 7025a7b95fbSBibby Hsieh err = pm_generic_runtime_suspend(&client->dev); 7035a7b95fbSBibby Hsieh if (err) 7045a7b95fbSBibby Hsieh return err; 7055a7b95fbSBibby Hsieh 7065a7b95fbSBibby Hsieh if (client->adapter->bus_regulator) 7075a7b95fbSBibby Hsieh return regulator_disable(client->adapter->bus_regulator); 7085a7b95fbSBibby Hsieh return 0; 7095a7b95fbSBibby Hsieh } 7105a7b95fbSBibby Hsieh #endif 7115a7b95fbSBibby Hsieh 7125a7b95fbSBibby Hsieh static const struct dev_pm_ops i2c_device_pm = { 7135a7b95fbSBibby Hsieh SET_LATE_SYSTEM_SLEEP_PM_OPS(i2c_suspend_late, i2c_resume_early) 7145a7b95fbSBibby Hsieh SET_RUNTIME_PM_OPS(i2c_runtime_suspend, i2c_runtime_resume, NULL) 7155a7b95fbSBibby Hsieh }; 7165a7b95fbSBibby Hsieh 71791ed5349SWolfram Sang static void i2c_device_shutdown(struct device *dev) 71891ed5349SWolfram Sang { 71991ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 72091ed5349SWolfram Sang struct i2c_driver *driver; 72191ed5349SWolfram Sang 72291ed5349SWolfram Sang if (!client || !dev->driver) 72391ed5349SWolfram Sang return; 72491ed5349SWolfram Sang driver = to_i2c_driver(dev->driver); 72591ed5349SWolfram Sang if (driver->shutdown) 72691ed5349SWolfram Sang driver->shutdown(client); 727b64210f2SDmitry Torokhov else if (client->irq > 0) 728b64210f2SDmitry Torokhov disable_irq(client->irq); 72991ed5349SWolfram Sang } 73091ed5349SWolfram Sang 73191ed5349SWolfram Sang static void i2c_client_dev_release(struct device *dev) 73291ed5349SWolfram Sang { 73391ed5349SWolfram Sang kfree(to_i2c_client(dev)); 73491ed5349SWolfram Sang } 73591ed5349SWolfram Sang 73691ed5349SWolfram Sang static ssize_t 73754a19fd4SGeert Uytterhoeven name_show(struct device *dev, struct device_attribute *attr, char *buf) 73891ed5349SWolfram Sang { 73991ed5349SWolfram Sang return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? 74091ed5349SWolfram Sang to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); 74191ed5349SWolfram Sang } 74254a19fd4SGeert Uytterhoeven static DEVICE_ATTR_RO(name); 74391ed5349SWolfram Sang 74491ed5349SWolfram Sang static ssize_t 74554a19fd4SGeert Uytterhoeven modalias_show(struct device *dev, struct device_attribute *attr, char *buf) 74691ed5349SWolfram Sang { 74791ed5349SWolfram Sang struct i2c_client *client = to_i2c_client(dev); 74891ed5349SWolfram Sang int len; 74991ed5349SWolfram Sang 750af503716SJavier Martinez Canillas len = of_device_modalias(dev, buf, PAGE_SIZE); 751af503716SJavier Martinez Canillas if (len != -ENODEV) 752af503716SJavier Martinez Canillas return len; 753af503716SJavier Martinez Canillas 75491ed5349SWolfram Sang len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); 75591ed5349SWolfram Sang if (len != -ENODEV) 75691ed5349SWolfram Sang return len; 75791ed5349SWolfram Sang 75891ed5349SWolfram Sang return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); 75991ed5349SWolfram Sang } 76054a19fd4SGeert Uytterhoeven static DEVICE_ATTR_RO(modalias); 76191ed5349SWolfram Sang 76291ed5349SWolfram Sang static struct attribute *i2c_dev_attrs[] = { 76391ed5349SWolfram Sang &dev_attr_name.attr, 76491ed5349SWolfram Sang /* modalias helps coldplug: modprobe $(cat .../modalias) */ 76591ed5349SWolfram Sang &dev_attr_modalias.attr, 76691ed5349SWolfram Sang NULL 76791ed5349SWolfram Sang }; 76891ed5349SWolfram Sang ATTRIBUTE_GROUPS(i2c_dev); 76991ed5349SWolfram Sang 77091ed5349SWolfram Sang struct bus_type i2c_bus_type = { 77191ed5349SWolfram Sang .name = "i2c", 77291ed5349SWolfram Sang .match = i2c_device_match, 77391ed5349SWolfram Sang .probe = i2c_device_probe, 77491ed5349SWolfram Sang .remove = i2c_device_remove, 77591ed5349SWolfram Sang .shutdown = i2c_device_shutdown, 7765a7b95fbSBibby Hsieh .pm = &i2c_device_pm, 77791ed5349SWolfram Sang }; 77891ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_bus_type); 77991ed5349SWolfram Sang 78091ed5349SWolfram Sang struct device_type i2c_client_type = { 78191ed5349SWolfram Sang .groups = i2c_dev_groups, 78291ed5349SWolfram Sang .uevent = i2c_device_uevent, 78391ed5349SWolfram Sang .release = i2c_client_dev_release, 78491ed5349SWolfram Sang }; 78591ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_client_type); 78691ed5349SWolfram Sang 78791ed5349SWolfram Sang 78891ed5349SWolfram Sang /** 78991ed5349SWolfram Sang * i2c_verify_client - return parameter as i2c_client, or NULL 79091ed5349SWolfram Sang * @dev: device, probably from some driver model iterator 79191ed5349SWolfram Sang * 79291ed5349SWolfram Sang * When traversing the driver model tree, perhaps using driver model 79391ed5349SWolfram Sang * iterators like @device_for_each_child(), you can't assume very much 79491ed5349SWolfram Sang * about the nodes you find. Use this function to avoid oopses caused 79591ed5349SWolfram Sang * by wrongly treating some non-I2C device as an i2c_client. 79691ed5349SWolfram Sang */ 79791ed5349SWolfram Sang struct i2c_client *i2c_verify_client(struct device *dev) 79891ed5349SWolfram Sang { 79991ed5349SWolfram Sang return (dev->type == &i2c_client_type) 80091ed5349SWolfram Sang ? to_i2c_client(dev) 80191ed5349SWolfram Sang : NULL; 80291ed5349SWolfram Sang } 80391ed5349SWolfram Sang EXPORT_SYMBOL(i2c_verify_client); 80491ed5349SWolfram Sang 80591ed5349SWolfram Sang 80691ed5349SWolfram Sang /* Return a unique address which takes the flags of the client into account */ 80791ed5349SWolfram Sang static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client) 80891ed5349SWolfram Sang { 80991ed5349SWolfram Sang unsigned short addr = client->addr; 81091ed5349SWolfram Sang 81191ed5349SWolfram Sang /* For some client flags, add an arbitrary offset to avoid collisions */ 81291ed5349SWolfram Sang if (client->flags & I2C_CLIENT_TEN) 81391ed5349SWolfram Sang addr |= I2C_ADDR_OFFSET_TEN_BIT; 81491ed5349SWolfram Sang 81591ed5349SWolfram Sang if (client->flags & I2C_CLIENT_SLAVE) 81691ed5349SWolfram Sang addr |= I2C_ADDR_OFFSET_SLAVE; 81791ed5349SWolfram Sang 81891ed5349SWolfram Sang return addr; 81991ed5349SWolfram Sang } 82091ed5349SWolfram Sang 82191ed5349SWolfram Sang /* This is a permissive address validity check, I2C address map constraints 82291ed5349SWolfram Sang * are purposely not enforced, except for the general call address. */ 823398432edSWolfram Sang static int i2c_check_addr_validity(unsigned int addr, unsigned short flags) 82491ed5349SWolfram Sang { 82591ed5349SWolfram Sang if (flags & I2C_CLIENT_TEN) { 82691ed5349SWolfram Sang /* 10-bit address, all values are valid */ 82791ed5349SWolfram Sang if (addr > 0x3ff) 82891ed5349SWolfram Sang return -EINVAL; 82991ed5349SWolfram Sang } else { 83091ed5349SWolfram Sang /* 7-bit address, reject the general call address */ 83191ed5349SWolfram Sang if (addr == 0x00 || addr > 0x7f) 83291ed5349SWolfram Sang return -EINVAL; 83391ed5349SWolfram Sang } 83491ed5349SWolfram Sang return 0; 83591ed5349SWolfram Sang } 83691ed5349SWolfram Sang 83791ed5349SWolfram Sang /* And this is a strict address validity check, used when probing. If a 83891ed5349SWolfram Sang * device uses a reserved address, then it shouldn't be probed. 7-bit 83991ed5349SWolfram Sang * addressing is assumed, 10-bit address devices are rare and should be 84091ed5349SWolfram Sang * explicitly enumerated. */ 841e4991ecdSWolfram Sang int i2c_check_7bit_addr_validity_strict(unsigned short addr) 84291ed5349SWolfram Sang { 84391ed5349SWolfram Sang /* 84491ed5349SWolfram Sang * Reserved addresses per I2C specification: 84591ed5349SWolfram Sang * 0x00 General call address / START byte 84691ed5349SWolfram Sang * 0x01 CBUS address 84791ed5349SWolfram Sang * 0x02 Reserved for different bus format 84891ed5349SWolfram Sang * 0x03 Reserved for future purposes 84991ed5349SWolfram Sang * 0x04-0x07 Hs-mode master code 85091ed5349SWolfram Sang * 0x78-0x7b 10-bit slave addressing 85191ed5349SWolfram Sang * 0x7c-0x7f Reserved for future purposes 85291ed5349SWolfram Sang */ 85391ed5349SWolfram Sang if (addr < 0x08 || addr > 0x77) 85491ed5349SWolfram Sang return -EINVAL; 85591ed5349SWolfram Sang return 0; 85691ed5349SWolfram Sang } 85791ed5349SWolfram Sang 85891ed5349SWolfram Sang static int __i2c_check_addr_busy(struct device *dev, void *addrp) 85991ed5349SWolfram Sang { 86091ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 86191ed5349SWolfram Sang int addr = *(int *)addrp; 86291ed5349SWolfram Sang 86391ed5349SWolfram Sang if (client && i2c_encode_flags_to_addr(client) == addr) 86491ed5349SWolfram Sang return -EBUSY; 86591ed5349SWolfram Sang return 0; 86691ed5349SWolfram Sang } 86791ed5349SWolfram Sang 86891ed5349SWolfram Sang /* walk up mux tree */ 86991ed5349SWolfram Sang static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) 87091ed5349SWolfram Sang { 87191ed5349SWolfram Sang struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); 87291ed5349SWolfram Sang int result; 87391ed5349SWolfram Sang 87491ed5349SWolfram Sang result = device_for_each_child(&adapter->dev, &addr, 87591ed5349SWolfram Sang __i2c_check_addr_busy); 87691ed5349SWolfram Sang 87791ed5349SWolfram Sang if (!result && parent) 87891ed5349SWolfram Sang result = i2c_check_mux_parents(parent, addr); 87991ed5349SWolfram Sang 88091ed5349SWolfram Sang return result; 88191ed5349SWolfram Sang } 88291ed5349SWolfram Sang 88391ed5349SWolfram Sang /* recurse down mux tree */ 88491ed5349SWolfram Sang static int i2c_check_mux_children(struct device *dev, void *addrp) 88591ed5349SWolfram Sang { 88691ed5349SWolfram Sang int result; 88791ed5349SWolfram Sang 88891ed5349SWolfram Sang if (dev->type == &i2c_adapter_type) 88991ed5349SWolfram Sang result = device_for_each_child(dev, addrp, 89091ed5349SWolfram Sang i2c_check_mux_children); 89191ed5349SWolfram Sang else 89291ed5349SWolfram Sang result = __i2c_check_addr_busy(dev, addrp); 89391ed5349SWolfram Sang 89491ed5349SWolfram Sang return result; 89591ed5349SWolfram Sang } 89691ed5349SWolfram Sang 89791ed5349SWolfram Sang static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) 89891ed5349SWolfram Sang { 89991ed5349SWolfram Sang struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); 90091ed5349SWolfram Sang int result = 0; 90191ed5349SWolfram Sang 90291ed5349SWolfram Sang if (parent) 90391ed5349SWolfram Sang result = i2c_check_mux_parents(parent, addr); 90491ed5349SWolfram Sang 90591ed5349SWolfram Sang if (!result) 90691ed5349SWolfram Sang result = device_for_each_child(&adapter->dev, &addr, 90791ed5349SWolfram Sang i2c_check_mux_children); 90891ed5349SWolfram Sang 90991ed5349SWolfram Sang return result; 91091ed5349SWolfram Sang } 91191ed5349SWolfram Sang 91291ed5349SWolfram Sang /** 91391ed5349SWolfram Sang * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment 91491ed5349SWolfram Sang * @adapter: Target I2C bus segment 91591ed5349SWolfram Sang * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 91691ed5349SWolfram Sang * locks only this branch in the adapter tree 91791ed5349SWolfram Sang */ 91891ed5349SWolfram Sang static void i2c_adapter_lock_bus(struct i2c_adapter *adapter, 91991ed5349SWolfram Sang unsigned int flags) 92091ed5349SWolfram Sang { 9217b94ea50SPeter Rosin rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter)); 92291ed5349SWolfram Sang } 92391ed5349SWolfram Sang 92491ed5349SWolfram Sang /** 92591ed5349SWolfram Sang * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment 92691ed5349SWolfram Sang * @adapter: Target I2C bus segment 92791ed5349SWolfram Sang * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT 92891ed5349SWolfram Sang * trylocks only this branch in the adapter tree 92991ed5349SWolfram Sang */ 93091ed5349SWolfram Sang static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter, 93191ed5349SWolfram Sang unsigned int flags) 93291ed5349SWolfram Sang { 93391ed5349SWolfram Sang return rt_mutex_trylock(&adapter->bus_lock); 93491ed5349SWolfram Sang } 93591ed5349SWolfram Sang 93691ed5349SWolfram Sang /** 93791ed5349SWolfram Sang * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment 93891ed5349SWolfram Sang * @adapter: Target I2C bus segment 93991ed5349SWolfram Sang * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 94091ed5349SWolfram Sang * unlocks only this branch in the adapter tree 94191ed5349SWolfram Sang */ 94291ed5349SWolfram Sang static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter, 94391ed5349SWolfram Sang unsigned int flags) 94491ed5349SWolfram Sang { 94591ed5349SWolfram Sang rt_mutex_unlock(&adapter->bus_lock); 94691ed5349SWolfram Sang } 94791ed5349SWolfram Sang 94891ed5349SWolfram Sang static void i2c_dev_set_name(struct i2c_adapter *adap, 949728fe6ceSHans de Goede struct i2c_client *client, 950728fe6ceSHans de Goede struct i2c_board_info const *info) 95191ed5349SWolfram Sang { 95291ed5349SWolfram Sang struct acpi_device *adev = ACPI_COMPANION(&client->dev); 95391ed5349SWolfram Sang 954728fe6ceSHans de Goede if (info && info->dev_name) { 955728fe6ceSHans de Goede dev_set_name(&client->dev, "i2c-%s", info->dev_name); 956728fe6ceSHans de Goede return; 957728fe6ceSHans de Goede } 958728fe6ceSHans de Goede 95991ed5349SWolfram Sang if (adev) { 96091ed5349SWolfram Sang dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); 96191ed5349SWolfram Sang return; 96291ed5349SWolfram Sang } 96391ed5349SWolfram Sang 96491ed5349SWolfram Sang dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), 96591ed5349SWolfram Sang i2c_encode_flags_to_addr(client)); 96691ed5349SWolfram Sang } 96791ed5349SWolfram Sang 9681d7534b6SCharles Keepax int i2c_dev_irq_from_resources(const struct resource *resources, 96991ed5349SWolfram Sang unsigned int num_resources) 97091ed5349SWolfram Sang { 97191ed5349SWolfram Sang struct irq_data *irqd; 97291ed5349SWolfram Sang int i; 97391ed5349SWolfram Sang 97491ed5349SWolfram Sang for (i = 0; i < num_resources; i++) { 97591ed5349SWolfram Sang const struct resource *r = &resources[i]; 97691ed5349SWolfram Sang 97791ed5349SWolfram Sang if (resource_type(r) != IORESOURCE_IRQ) 97891ed5349SWolfram Sang continue; 97991ed5349SWolfram Sang 98091ed5349SWolfram Sang if (r->flags & IORESOURCE_BITS) { 98191ed5349SWolfram Sang irqd = irq_get_irq_data(r->start); 98291ed5349SWolfram Sang if (!irqd) 98391ed5349SWolfram Sang break; 98491ed5349SWolfram Sang 98591ed5349SWolfram Sang irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); 98691ed5349SWolfram Sang } 98791ed5349SWolfram Sang 98891ed5349SWolfram Sang return r->start; 98991ed5349SWolfram Sang } 99091ed5349SWolfram Sang 99191ed5349SWolfram Sang return 0; 99291ed5349SWolfram Sang } 99391ed5349SWolfram Sang 99491ed5349SWolfram Sang /** 9957159dbdaSHeiner Kallweit * i2c_new_client_device - instantiate an i2c device 99691ed5349SWolfram Sang * @adap: the adapter managing the device 99791ed5349SWolfram Sang * @info: describes one I2C device; bus_num is ignored 99891ed5349SWolfram Sang * Context: can sleep 99991ed5349SWolfram Sang * 100091ed5349SWolfram Sang * Create an i2c device. Binding is handled through driver model 100191ed5349SWolfram Sang * probe()/remove() methods. A driver may be bound to this device when we 100291ed5349SWolfram Sang * return from this function, or any later moment (e.g. maybe hotplugging will 100391ed5349SWolfram Sang * load the driver module). This call is not appropriate for use by mainboard 100491ed5349SWolfram Sang * initialization logic, which usually runs during an arch_initcall() long 100591ed5349SWolfram Sang * before any i2c_adapter could exist. 100691ed5349SWolfram Sang * 100791ed5349SWolfram Sang * This returns the new i2c client, which may be saved for later use with 10087159dbdaSHeiner Kallweit * i2c_unregister_device(); or an ERR_PTR to describe the error. 100991ed5349SWolfram Sang */ 1010550113d4SWolfram Sang struct i2c_client * 10117159dbdaSHeiner Kallweit i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info) 101291ed5349SWolfram Sang { 101391ed5349SWolfram Sang struct i2c_client *client; 101491ed5349SWolfram Sang int status; 101591ed5349SWolfram Sang 101691ed5349SWolfram Sang client = kzalloc(sizeof *client, GFP_KERNEL); 101791ed5349SWolfram Sang if (!client) 10187159dbdaSHeiner Kallweit return ERR_PTR(-ENOMEM); 101991ed5349SWolfram Sang 102091ed5349SWolfram Sang client->adapter = adap; 102191ed5349SWolfram Sang 102291ed5349SWolfram Sang client->dev.platform_data = info->platform_data; 102391ed5349SWolfram Sang client->flags = info->flags; 102491ed5349SWolfram Sang client->addr = info->addr; 102591ed5349SWolfram Sang 102693b6604cSJim Broadus client->init_irq = info->irq; 102793b6604cSJim Broadus if (!client->init_irq) 102893b6604cSJim Broadus client->init_irq = i2c_dev_irq_from_resources(info->resources, 102991ed5349SWolfram Sang info->num_resources); 103091ed5349SWolfram Sang 103191ed5349SWolfram Sang strlcpy(client->name, info->type, sizeof(client->name)); 103291ed5349SWolfram Sang 103391ed5349SWolfram Sang status = i2c_check_addr_validity(client->addr, client->flags); 103491ed5349SWolfram Sang if (status) { 103591ed5349SWolfram Sang dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", 103691ed5349SWolfram Sang client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); 103791ed5349SWolfram Sang goto out_err_silent; 103891ed5349SWolfram Sang } 103991ed5349SWolfram Sang 104091ed5349SWolfram Sang /* Check for address business */ 104191ed5349SWolfram Sang status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client)); 104291ed5349SWolfram Sang if (status) 104391ed5349SWolfram Sang goto out_err; 104491ed5349SWolfram Sang 104591ed5349SWolfram Sang client->dev.parent = &client->adapter->dev; 104691ed5349SWolfram Sang client->dev.bus = &i2c_bus_type; 104791ed5349SWolfram Sang client->dev.type = &i2c_client_type; 104804782265SBoris Brezillon client->dev.of_node = of_node_get(info->of_node); 104991ed5349SWolfram Sang client->dev.fwnode = info->fwnode; 105091ed5349SWolfram Sang 1051*172d9319SDerek Basehore device_enable_async_suspend(&client->dev); 1052728fe6ceSHans de Goede i2c_dev_set_name(adap, client, info); 105391ed5349SWolfram Sang 1054714638e0SHeikki Krogerus if (info->swnode) { 1055714638e0SHeikki Krogerus status = device_add_software_node(&client->dev, info->swnode); 105691ed5349SWolfram Sang if (status) { 105791ed5349SWolfram Sang dev_err(&adap->dev, 1058714638e0SHeikki Krogerus "Failed to add software node to client %s: %d\n", 105991ed5349SWolfram Sang client->name, status); 106004782265SBoris Brezillon goto out_err_put_of_node; 106191ed5349SWolfram Sang } 106291ed5349SWolfram Sang } 106391ed5349SWolfram Sang 106491ed5349SWolfram Sang status = device_register(&client->dev); 106591ed5349SWolfram Sang if (status) 1066714638e0SHeikki Krogerus goto out_remove_swnode; 106791ed5349SWolfram Sang 106891ed5349SWolfram Sang dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", 106991ed5349SWolfram Sang client->name, dev_name(&client->dev)); 107091ed5349SWolfram Sang 107191ed5349SWolfram Sang return client; 107291ed5349SWolfram Sang 1073714638e0SHeikki Krogerus out_remove_swnode: 1074714638e0SHeikki Krogerus device_remove_software_node(&client->dev); 107504782265SBoris Brezillon out_err_put_of_node: 107604782265SBoris Brezillon of_node_put(info->of_node); 107791ed5349SWolfram Sang out_err: 107891ed5349SWolfram Sang dev_err(&adap->dev, 107991ed5349SWolfram Sang "Failed to register i2c client %s at 0x%02x (%d)\n", 108091ed5349SWolfram Sang client->name, client->addr, status); 108191ed5349SWolfram Sang out_err_silent: 108291ed5349SWolfram Sang kfree(client); 10837159dbdaSHeiner Kallweit return ERR_PTR(status); 10847159dbdaSHeiner Kallweit } 10857159dbdaSHeiner Kallweit EXPORT_SYMBOL_GPL(i2c_new_client_device); 10867159dbdaSHeiner Kallweit 10877159dbdaSHeiner Kallweit /** 108887e07437SWolfram Sang * i2c_unregister_device - reverse effect of i2c_new_*_device() 108987e07437SWolfram Sang * @client: value returned from i2c_new_*_device() 109091ed5349SWolfram Sang * Context: can sleep 109191ed5349SWolfram Sang */ 109291ed5349SWolfram Sang void i2c_unregister_device(struct i2c_client *client) 109391ed5349SWolfram Sang { 1094689f5358SWolfram Sang if (IS_ERR_OR_NULL(client)) 10957b43dd19SAndy Shevchenko return; 1096e0638fa4SLixin Wang 1097e0638fa4SLixin Wang if (client->dev.of_node) { 109891ed5349SWolfram Sang of_node_clear_flag(client->dev.of_node, OF_POPULATED); 1099e0638fa4SLixin Wang of_node_put(client->dev.of_node); 1100e0638fa4SLixin Wang } 1101e0638fa4SLixin Wang 110291ed5349SWolfram Sang if (ACPI_COMPANION(&client->dev)) 110391ed5349SWolfram Sang acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev)); 1104714638e0SHeikki Krogerus device_remove_software_node(&client->dev); 110591ed5349SWolfram Sang device_unregister(&client->dev); 110691ed5349SWolfram Sang } 110791ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_unregister_device); 110891ed5349SWolfram Sang 110991ed5349SWolfram Sang 111091ed5349SWolfram Sang static const struct i2c_device_id dummy_id[] = { 111191ed5349SWolfram Sang { "dummy", 0 }, 111291ed5349SWolfram Sang { }, 111391ed5349SWolfram Sang }; 111491ed5349SWolfram Sang 111591ed5349SWolfram Sang static int dummy_probe(struct i2c_client *client, 111691ed5349SWolfram Sang const struct i2c_device_id *id) 111791ed5349SWolfram Sang { 111891ed5349SWolfram Sang return 0; 111991ed5349SWolfram Sang } 112091ed5349SWolfram Sang 112191ed5349SWolfram Sang static int dummy_remove(struct i2c_client *client) 112291ed5349SWolfram Sang { 112391ed5349SWolfram Sang return 0; 112491ed5349SWolfram Sang } 112591ed5349SWolfram Sang 112691ed5349SWolfram Sang static struct i2c_driver dummy_driver = { 112791ed5349SWolfram Sang .driver.name = "dummy", 112891ed5349SWolfram Sang .probe = dummy_probe, 112991ed5349SWolfram Sang .remove = dummy_remove, 113091ed5349SWolfram Sang .id_table = dummy_id, 113191ed5349SWolfram Sang }; 113291ed5349SWolfram Sang 113391ed5349SWolfram Sang /** 11347159dbdaSHeiner Kallweit * i2c_new_dummy_device - return a new i2c device bound to a dummy driver 113591ed5349SWolfram Sang * @adapter: the adapter managing the device 113691ed5349SWolfram Sang * @address: seven bit address to be used 113791ed5349SWolfram Sang * Context: can sleep 113891ed5349SWolfram Sang * 113991ed5349SWolfram Sang * This returns an I2C client bound to the "dummy" driver, intended for use 114091ed5349SWolfram Sang * with devices that consume multiple addresses. Examples of such chips 114191ed5349SWolfram Sang * include various EEPROMS (like 24c04 and 24c08 models). 114291ed5349SWolfram Sang * 114391ed5349SWolfram Sang * These dummy devices have two main uses. First, most I2C and SMBus calls 114491ed5349SWolfram Sang * except i2c_transfer() need a client handle; the dummy will be that handle. 114591ed5349SWolfram Sang * And second, this prevents the specified address from being bound to a 114691ed5349SWolfram Sang * different driver. 114791ed5349SWolfram Sang * 114891ed5349SWolfram Sang * This returns the new i2c client, which should be saved for later use with 11497159dbdaSHeiner Kallweit * i2c_unregister_device(); or an ERR_PTR to describe the error. 115091ed5349SWolfram Sang */ 1151550113d4SWolfram Sang struct i2c_client *i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address) 115291ed5349SWolfram Sang { 115391ed5349SWolfram Sang struct i2c_board_info info = { 115491ed5349SWolfram Sang I2C_BOARD_INFO("dummy", address), 115591ed5349SWolfram Sang }; 115691ed5349SWolfram Sang 11577159dbdaSHeiner Kallweit return i2c_new_client_device(adapter, &info); 11587159dbdaSHeiner Kallweit } 11597159dbdaSHeiner Kallweit EXPORT_SYMBOL_GPL(i2c_new_dummy_device); 11607159dbdaSHeiner Kallweit 1161bb7f086bSYicong Yang static void devm_i2c_release_dummy(void *client) 1162b8f5fe3bSHeiner Kallweit { 1163bb7f086bSYicong Yang i2c_unregister_device(client); 1164b8f5fe3bSHeiner Kallweit } 1165b8f5fe3bSHeiner Kallweit 1166b8f5fe3bSHeiner Kallweit /** 1167b8f5fe3bSHeiner Kallweit * devm_i2c_new_dummy_device - return a new i2c device bound to a dummy driver 1168b8f5fe3bSHeiner Kallweit * @dev: device the managed resource is bound to 1169b8f5fe3bSHeiner Kallweit * @adapter: the adapter managing the device 1170b8f5fe3bSHeiner Kallweit * @address: seven bit address to be used 1171b8f5fe3bSHeiner Kallweit * Context: can sleep 1172b8f5fe3bSHeiner Kallweit * 1173b8f5fe3bSHeiner Kallweit * This is the device-managed version of @i2c_new_dummy_device. It returns the 1174b8f5fe3bSHeiner Kallweit * new i2c client or an ERR_PTR in case of an error. 1175b8f5fe3bSHeiner Kallweit */ 1176b8f5fe3bSHeiner Kallweit struct i2c_client *devm_i2c_new_dummy_device(struct device *dev, 1177b8f5fe3bSHeiner Kallweit struct i2c_adapter *adapter, 1178b8f5fe3bSHeiner Kallweit u16 address) 1179b8f5fe3bSHeiner Kallweit { 1180b8f5fe3bSHeiner Kallweit struct i2c_client *client; 1181bb7f086bSYicong Yang int ret; 1182b8f5fe3bSHeiner Kallweit 1183b8f5fe3bSHeiner Kallweit client = i2c_new_dummy_device(adapter, address); 1184bb7f086bSYicong Yang if (IS_ERR(client)) 1185bb7f086bSYicong Yang return client; 1186bb7f086bSYicong Yang 1187bb7f086bSYicong Yang ret = devm_add_action_or_reset(dev, devm_i2c_release_dummy, client); 1188bb7f086bSYicong Yang if (ret) 1189bb7f086bSYicong Yang return ERR_PTR(ret); 1190b8f5fe3bSHeiner Kallweit 1191b8f5fe3bSHeiner Kallweit return client; 1192b8f5fe3bSHeiner Kallweit } 1193b8f5fe3bSHeiner Kallweit EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device); 1194b8f5fe3bSHeiner Kallweit 119591ed5349SWolfram Sang /** 1196af80559bSWolfram Sang * i2c_new_ancillary_device - Helper to get the instantiated secondary address 119791ed5349SWolfram Sang * and create the associated device 119891ed5349SWolfram Sang * @client: Handle to the primary client 119991ed5349SWolfram Sang * @name: Handle to specify which secondary address to get 120091ed5349SWolfram Sang * @default_addr: Used as a fallback if no secondary address was specified 120191ed5349SWolfram Sang * Context: can sleep 120291ed5349SWolfram Sang * 120391ed5349SWolfram Sang * I2C clients can be composed of multiple I2C slaves bound together in a single 120491ed5349SWolfram Sang * component. The I2C client driver then binds to the master I2C slave and needs 120591ed5349SWolfram Sang * to create I2C dummy clients to communicate with all the other slaves. 120691ed5349SWolfram Sang * 120791ed5349SWolfram Sang * This function creates and returns an I2C dummy client whose I2C address is 120891ed5349SWolfram Sang * retrieved from the platform firmware based on the given slave name. If no 120991ed5349SWolfram Sang * address is specified by the firmware default_addr is used. 121091ed5349SWolfram Sang * 121191ed5349SWolfram Sang * On DT-based platforms the address is retrieved from the "reg" property entry 121291ed5349SWolfram Sang * cell whose "reg-names" value matches the slave name. 121391ed5349SWolfram Sang * 121491ed5349SWolfram Sang * This returns the new i2c client, which should be saved for later use with 1215af80559bSWolfram Sang * i2c_unregister_device(); or an ERR_PTR to describe the error. 121691ed5349SWolfram Sang */ 1217af80559bSWolfram Sang struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client, 121891ed5349SWolfram Sang const char *name, 121991ed5349SWolfram Sang u16 default_addr) 122091ed5349SWolfram Sang { 122191ed5349SWolfram Sang struct device_node *np = client->dev.of_node; 122291ed5349SWolfram Sang u32 addr = default_addr; 122391ed5349SWolfram Sang int i; 122491ed5349SWolfram Sang 122591ed5349SWolfram Sang if (np) { 122691ed5349SWolfram Sang i = of_property_match_string(np, "reg-names", name); 122791ed5349SWolfram Sang if (i >= 0) 122891ed5349SWolfram Sang of_property_read_u32_index(np, "reg", i, &addr); 122991ed5349SWolfram Sang } 123091ed5349SWolfram Sang 123191ed5349SWolfram Sang dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr); 1232af80559bSWolfram Sang return i2c_new_dummy_device(client->adapter, addr); 123391ed5349SWolfram Sang } 1234af80559bSWolfram Sang EXPORT_SYMBOL_GPL(i2c_new_ancillary_device); 123591ed5349SWolfram Sang 123691ed5349SWolfram Sang /* ------------------------------------------------------------------------- */ 123791ed5349SWolfram Sang 123891ed5349SWolfram Sang /* I2C bus adapters -- one roots each I2C or SMBUS segment */ 123991ed5349SWolfram Sang 124091ed5349SWolfram Sang static void i2c_adapter_dev_release(struct device *dev) 124191ed5349SWolfram Sang { 124291ed5349SWolfram Sang struct i2c_adapter *adap = to_i2c_adapter(dev); 124391ed5349SWolfram Sang complete(&adap->dev_released); 124491ed5349SWolfram Sang } 124591ed5349SWolfram Sang 124691ed5349SWolfram Sang unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) 124791ed5349SWolfram Sang { 124891ed5349SWolfram Sang unsigned int depth = 0; 124991ed5349SWolfram Sang 125091ed5349SWolfram Sang while ((adapter = i2c_parent_is_i2c_adapter(adapter))) 125191ed5349SWolfram Sang depth++; 125291ed5349SWolfram Sang 125391ed5349SWolfram Sang WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES, 125491ed5349SWolfram Sang "adapter depth exceeds lockdep subclass limit\n"); 125591ed5349SWolfram Sang 125691ed5349SWolfram Sang return depth; 125791ed5349SWolfram Sang } 125891ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_adapter_depth); 125991ed5349SWolfram Sang 126091ed5349SWolfram Sang /* 126191ed5349SWolfram Sang * Let users instantiate I2C devices through sysfs. This can be used when 126291ed5349SWolfram Sang * platform initialization code doesn't contain the proper data for 126391ed5349SWolfram Sang * whatever reason. Also useful for drivers that do device detection and 126491ed5349SWolfram Sang * detection fails, either because the device uses an unexpected address, 126591ed5349SWolfram Sang * or this is a compatible device with different ID register values. 126691ed5349SWolfram Sang * 126791ed5349SWolfram Sang * Parameter checking may look overzealous, but we really don't want 126891ed5349SWolfram Sang * the user to provide incorrect parameters. 126991ed5349SWolfram Sang */ 127091ed5349SWolfram Sang static ssize_t 127154a19fd4SGeert Uytterhoeven new_device_store(struct device *dev, struct device_attribute *attr, 127291ed5349SWolfram Sang const char *buf, size_t count) 127391ed5349SWolfram Sang { 127491ed5349SWolfram Sang struct i2c_adapter *adap = to_i2c_adapter(dev); 127591ed5349SWolfram Sang struct i2c_board_info info; 127691ed5349SWolfram Sang struct i2c_client *client; 127791ed5349SWolfram Sang char *blank, end; 127891ed5349SWolfram Sang int res; 127991ed5349SWolfram Sang 128091ed5349SWolfram Sang memset(&info, 0, sizeof(struct i2c_board_info)); 128191ed5349SWolfram Sang 128291ed5349SWolfram Sang blank = strchr(buf, ' '); 128391ed5349SWolfram Sang if (!blank) { 128491ed5349SWolfram Sang dev_err(dev, "%s: Missing parameters\n", "new_device"); 128591ed5349SWolfram Sang return -EINVAL; 128691ed5349SWolfram Sang } 128791ed5349SWolfram Sang if (blank - buf > I2C_NAME_SIZE - 1) { 128891ed5349SWolfram Sang dev_err(dev, "%s: Invalid device name\n", "new_device"); 128991ed5349SWolfram Sang return -EINVAL; 129091ed5349SWolfram Sang } 129191ed5349SWolfram Sang memcpy(info.type, buf, blank - buf); 129291ed5349SWolfram Sang 129391ed5349SWolfram Sang /* Parse remaining parameters, reject extra parameters */ 129491ed5349SWolfram Sang res = sscanf(++blank, "%hi%c", &info.addr, &end); 129591ed5349SWolfram Sang if (res < 1) { 129691ed5349SWolfram Sang dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); 129791ed5349SWolfram Sang return -EINVAL; 129891ed5349SWolfram Sang } 129991ed5349SWolfram Sang if (res > 1 && end != '\n') { 130091ed5349SWolfram Sang dev_err(dev, "%s: Extra parameters\n", "new_device"); 130191ed5349SWolfram Sang return -EINVAL; 130291ed5349SWolfram Sang } 130391ed5349SWolfram Sang 130491ed5349SWolfram Sang if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) { 130591ed5349SWolfram Sang info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT; 130691ed5349SWolfram Sang info.flags |= I2C_CLIENT_TEN; 130791ed5349SWolfram Sang } 130891ed5349SWolfram Sang 130991ed5349SWolfram Sang if (info.addr & I2C_ADDR_OFFSET_SLAVE) { 131091ed5349SWolfram Sang info.addr &= ~I2C_ADDR_OFFSET_SLAVE; 131191ed5349SWolfram Sang info.flags |= I2C_CLIENT_SLAVE; 131291ed5349SWolfram Sang } 131391ed5349SWolfram Sang 13147159dbdaSHeiner Kallweit client = i2c_new_client_device(adap, &info); 13157159dbdaSHeiner Kallweit if (IS_ERR(client)) 13167159dbdaSHeiner Kallweit return PTR_ERR(client); 131791ed5349SWolfram Sang 131891ed5349SWolfram Sang /* Keep track of the added device */ 131991ed5349SWolfram Sang mutex_lock(&adap->userspace_clients_lock); 132091ed5349SWolfram Sang list_add_tail(&client->detected, &adap->userspace_clients); 132191ed5349SWolfram Sang mutex_unlock(&adap->userspace_clients_lock); 132291ed5349SWolfram Sang dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", 132391ed5349SWolfram Sang info.type, info.addr); 132491ed5349SWolfram Sang 132591ed5349SWolfram Sang return count; 132691ed5349SWolfram Sang } 132754a19fd4SGeert Uytterhoeven static DEVICE_ATTR_WO(new_device); 132891ed5349SWolfram Sang 132991ed5349SWolfram Sang /* 133091ed5349SWolfram Sang * And of course let the users delete the devices they instantiated, if 133191ed5349SWolfram Sang * they got it wrong. This interface can only be used to delete devices 133291ed5349SWolfram Sang * instantiated by i2c_sysfs_new_device above. This guarantees that we 133391ed5349SWolfram Sang * don't delete devices to which some kernel code still has references. 133491ed5349SWolfram Sang * 133591ed5349SWolfram Sang * Parameter checking may look overzealous, but we really don't want 133691ed5349SWolfram Sang * the user to delete the wrong device. 133791ed5349SWolfram Sang */ 133891ed5349SWolfram Sang static ssize_t 133954a19fd4SGeert Uytterhoeven delete_device_store(struct device *dev, struct device_attribute *attr, 134091ed5349SWolfram Sang const char *buf, size_t count) 134191ed5349SWolfram Sang { 134291ed5349SWolfram Sang struct i2c_adapter *adap = to_i2c_adapter(dev); 134391ed5349SWolfram Sang struct i2c_client *client, *next; 134491ed5349SWolfram Sang unsigned short addr; 134591ed5349SWolfram Sang char end; 134691ed5349SWolfram Sang int res; 134791ed5349SWolfram Sang 134891ed5349SWolfram Sang /* Parse parameters, reject extra parameters */ 134991ed5349SWolfram Sang res = sscanf(buf, "%hi%c", &addr, &end); 135091ed5349SWolfram Sang if (res < 1) { 135191ed5349SWolfram Sang dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); 135291ed5349SWolfram Sang return -EINVAL; 135391ed5349SWolfram Sang } 135491ed5349SWolfram Sang if (res > 1 && end != '\n') { 135591ed5349SWolfram Sang dev_err(dev, "%s: Extra parameters\n", "delete_device"); 135691ed5349SWolfram Sang return -EINVAL; 135791ed5349SWolfram Sang } 135891ed5349SWolfram Sang 135991ed5349SWolfram Sang /* Make sure the device was added through sysfs */ 136091ed5349SWolfram Sang res = -ENOENT; 136191ed5349SWolfram Sang mutex_lock_nested(&adap->userspace_clients_lock, 136291ed5349SWolfram Sang i2c_adapter_depth(adap)); 136391ed5349SWolfram Sang list_for_each_entry_safe(client, next, &adap->userspace_clients, 136491ed5349SWolfram Sang detected) { 136591ed5349SWolfram Sang if (i2c_encode_flags_to_addr(client) == addr) { 136691ed5349SWolfram Sang dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", 136791ed5349SWolfram Sang "delete_device", client->name, client->addr); 136891ed5349SWolfram Sang 136991ed5349SWolfram Sang list_del(&client->detected); 137091ed5349SWolfram Sang i2c_unregister_device(client); 137191ed5349SWolfram Sang res = count; 137291ed5349SWolfram Sang break; 137391ed5349SWolfram Sang } 137491ed5349SWolfram Sang } 137591ed5349SWolfram Sang mutex_unlock(&adap->userspace_clients_lock); 137691ed5349SWolfram Sang 137791ed5349SWolfram Sang if (res < 0) 137891ed5349SWolfram Sang dev_err(dev, "%s: Can't find device in list\n", 137991ed5349SWolfram Sang "delete_device"); 138091ed5349SWolfram Sang return res; 138191ed5349SWolfram Sang } 138291ed5349SWolfram Sang static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, 138354a19fd4SGeert Uytterhoeven delete_device_store); 138491ed5349SWolfram Sang 138591ed5349SWolfram Sang static struct attribute *i2c_adapter_attrs[] = { 138691ed5349SWolfram Sang &dev_attr_name.attr, 138791ed5349SWolfram Sang &dev_attr_new_device.attr, 138891ed5349SWolfram Sang &dev_attr_delete_device.attr, 138991ed5349SWolfram Sang NULL 139091ed5349SWolfram Sang }; 139191ed5349SWolfram Sang ATTRIBUTE_GROUPS(i2c_adapter); 139291ed5349SWolfram Sang 139391ed5349SWolfram Sang struct device_type i2c_adapter_type = { 139491ed5349SWolfram Sang .groups = i2c_adapter_groups, 139591ed5349SWolfram Sang .release = i2c_adapter_dev_release, 139691ed5349SWolfram Sang }; 139791ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_adapter_type); 139891ed5349SWolfram Sang 139991ed5349SWolfram Sang /** 140091ed5349SWolfram Sang * i2c_verify_adapter - return parameter as i2c_adapter or NULL 140191ed5349SWolfram Sang * @dev: device, probably from some driver model iterator 140291ed5349SWolfram Sang * 140391ed5349SWolfram Sang * When traversing the driver model tree, perhaps using driver model 140491ed5349SWolfram Sang * iterators like @device_for_each_child(), you can't assume very much 140591ed5349SWolfram Sang * about the nodes you find. Use this function to avoid oopses caused 140691ed5349SWolfram Sang * by wrongly treating some non-I2C device as an i2c_adapter. 140791ed5349SWolfram Sang */ 140891ed5349SWolfram Sang struct i2c_adapter *i2c_verify_adapter(struct device *dev) 140991ed5349SWolfram Sang { 141091ed5349SWolfram Sang return (dev->type == &i2c_adapter_type) 141191ed5349SWolfram Sang ? to_i2c_adapter(dev) 141291ed5349SWolfram Sang : NULL; 141391ed5349SWolfram Sang } 141491ed5349SWolfram Sang EXPORT_SYMBOL(i2c_verify_adapter); 141591ed5349SWolfram Sang 141691ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 141791ed5349SWolfram Sang static struct class_compat *i2c_adapter_compat_class; 141891ed5349SWolfram Sang #endif 141991ed5349SWolfram Sang 142091ed5349SWolfram Sang static void i2c_scan_static_board_info(struct i2c_adapter *adapter) 142191ed5349SWolfram Sang { 142291ed5349SWolfram Sang struct i2c_devinfo *devinfo; 142391ed5349SWolfram Sang 142491ed5349SWolfram Sang down_read(&__i2c_board_lock); 142591ed5349SWolfram Sang list_for_each_entry(devinfo, &__i2c_board_list, list) { 142687e07437SWolfram Sang if (devinfo->busnum == adapter->nr && 142787e07437SWolfram Sang IS_ERR(i2c_new_client_device(adapter, &devinfo->board_info))) 142891ed5349SWolfram Sang dev_err(&adapter->dev, 142991ed5349SWolfram Sang "Can't create device at 0x%02x\n", 143091ed5349SWolfram Sang devinfo->board_info.addr); 143191ed5349SWolfram Sang } 143291ed5349SWolfram Sang up_read(&__i2c_board_lock); 143391ed5349SWolfram Sang } 143491ed5349SWolfram Sang 143591ed5349SWolfram Sang static int i2c_do_add_adapter(struct i2c_driver *driver, 143691ed5349SWolfram Sang struct i2c_adapter *adap) 143791ed5349SWolfram Sang { 143891ed5349SWolfram Sang /* Detect supported devices on that bus, and instantiate them */ 143991ed5349SWolfram Sang i2c_detect(adap, driver); 144091ed5349SWolfram Sang 144191ed5349SWolfram Sang return 0; 144291ed5349SWolfram Sang } 144391ed5349SWolfram Sang 144491ed5349SWolfram Sang static int __process_new_adapter(struct device_driver *d, void *data) 144591ed5349SWolfram Sang { 144691ed5349SWolfram Sang return i2c_do_add_adapter(to_i2c_driver(d), data); 144791ed5349SWolfram Sang } 144891ed5349SWolfram Sang 144991ed5349SWolfram Sang static const struct i2c_lock_operations i2c_adapter_lock_ops = { 145091ed5349SWolfram Sang .lock_bus = i2c_adapter_lock_bus, 145191ed5349SWolfram Sang .trylock_bus = i2c_adapter_trylock_bus, 145291ed5349SWolfram Sang .unlock_bus = i2c_adapter_unlock_bus, 145391ed5349SWolfram Sang }; 145491ed5349SWolfram Sang 145591ed5349SWolfram Sang static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap) 145691ed5349SWolfram Sang { 145791ed5349SWolfram Sang struct irq_domain *domain = adap->host_notify_domain; 145891ed5349SWolfram Sang irq_hw_number_t hwirq; 145991ed5349SWolfram Sang 146091ed5349SWolfram Sang if (!domain) 146191ed5349SWolfram Sang return; 146291ed5349SWolfram Sang 146391ed5349SWolfram Sang for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++) 146491ed5349SWolfram Sang irq_dispose_mapping(irq_find_mapping(domain, hwirq)); 146591ed5349SWolfram Sang 146691ed5349SWolfram Sang irq_domain_remove(domain); 146791ed5349SWolfram Sang adap->host_notify_domain = NULL; 146891ed5349SWolfram Sang } 146991ed5349SWolfram Sang 147091ed5349SWolfram Sang static int i2c_host_notify_irq_map(struct irq_domain *h, 147191ed5349SWolfram Sang unsigned int virq, 147291ed5349SWolfram Sang irq_hw_number_t hw_irq_num) 147391ed5349SWolfram Sang { 147491ed5349SWolfram Sang irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq); 147591ed5349SWolfram Sang 147691ed5349SWolfram Sang return 0; 147791ed5349SWolfram Sang } 147891ed5349SWolfram Sang 147991ed5349SWolfram Sang static const struct irq_domain_ops i2c_host_notify_irq_ops = { 148091ed5349SWolfram Sang .map = i2c_host_notify_irq_map, 148191ed5349SWolfram Sang }; 148291ed5349SWolfram Sang 148391ed5349SWolfram Sang static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap) 148491ed5349SWolfram Sang { 148591ed5349SWolfram Sang struct irq_domain *domain; 148691ed5349SWolfram Sang 148791ed5349SWolfram Sang if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY)) 148891ed5349SWolfram Sang return 0; 148991ed5349SWolfram Sang 14908682dc12SWolfram Sang domain = irq_domain_create_linear(adap->dev.parent->fwnode, 149191ed5349SWolfram Sang I2C_ADDR_7BITS_COUNT, 149291ed5349SWolfram Sang &i2c_host_notify_irq_ops, adap); 149391ed5349SWolfram Sang if (!domain) 149491ed5349SWolfram Sang return -ENOMEM; 149591ed5349SWolfram Sang 149691ed5349SWolfram Sang adap->host_notify_domain = domain; 149791ed5349SWolfram Sang 149891ed5349SWolfram Sang return 0; 149991ed5349SWolfram Sang } 150091ed5349SWolfram Sang 150191ed5349SWolfram Sang /** 150291ed5349SWolfram Sang * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct 150391ed5349SWolfram Sang * I2C client. 150491ed5349SWolfram Sang * @adap: the adapter 150591ed5349SWolfram Sang * @addr: the I2C address of the notifying device 150691ed5349SWolfram Sang * Context: can't sleep 150791ed5349SWolfram Sang * 150891ed5349SWolfram Sang * Helper function to be called from an I2C bus driver's interrupt 150991ed5349SWolfram Sang * handler. It will schedule the Host Notify IRQ. 151091ed5349SWolfram Sang */ 151191ed5349SWolfram Sang int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr) 151291ed5349SWolfram Sang { 151391ed5349SWolfram Sang int irq; 151491ed5349SWolfram Sang 151591ed5349SWolfram Sang if (!adap) 151691ed5349SWolfram Sang return -EINVAL; 151791ed5349SWolfram Sang 151891ed5349SWolfram Sang irq = irq_find_mapping(adap->host_notify_domain, addr); 151991ed5349SWolfram Sang if (irq <= 0) 152091ed5349SWolfram Sang return -ENXIO; 152191ed5349SWolfram Sang 152291ed5349SWolfram Sang generic_handle_irq(irq); 152391ed5349SWolfram Sang 152491ed5349SWolfram Sang return 0; 152591ed5349SWolfram Sang } 152691ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify); 152791ed5349SWolfram Sang 152891ed5349SWolfram Sang static int i2c_register_adapter(struct i2c_adapter *adap) 152991ed5349SWolfram Sang { 153091ed5349SWolfram Sang int res = -EINVAL; 153191ed5349SWolfram Sang 153291ed5349SWolfram Sang /* Can't register until after driver model init */ 153391ed5349SWolfram Sang if (WARN_ON(!is_registered)) { 153491ed5349SWolfram Sang res = -EAGAIN; 153591ed5349SWolfram Sang goto out_list; 153691ed5349SWolfram Sang } 153791ed5349SWolfram Sang 153891ed5349SWolfram Sang /* Sanity checks */ 153991ed5349SWolfram Sang if (WARN(!adap->name[0], "i2c adapter has no name")) 154091ed5349SWolfram Sang goto out_list; 154191ed5349SWolfram Sang 154291ed5349SWolfram Sang if (!adap->algo) { 154391ed5349SWolfram Sang pr_err("adapter '%s': no algo supplied!\n", adap->name); 154491ed5349SWolfram Sang goto out_list; 154591ed5349SWolfram Sang } 154691ed5349SWolfram Sang 154791ed5349SWolfram Sang if (!adap->lock_ops) 154891ed5349SWolfram Sang adap->lock_ops = &i2c_adapter_lock_ops; 154991ed5349SWolfram Sang 15509ac6cb5fSWolfram Sang adap->locked_flags = 0; 155191ed5349SWolfram Sang rt_mutex_init(&adap->bus_lock); 155291ed5349SWolfram Sang rt_mutex_init(&adap->mux_lock); 155391ed5349SWolfram Sang mutex_init(&adap->userspace_clients_lock); 155491ed5349SWolfram Sang INIT_LIST_HEAD(&adap->userspace_clients); 155591ed5349SWolfram Sang 155691ed5349SWolfram Sang /* Set default timeout to 1 second if not already set */ 155791ed5349SWolfram Sang if (adap->timeout == 0) 155891ed5349SWolfram Sang adap->timeout = HZ; 155991ed5349SWolfram Sang 156091ed5349SWolfram Sang /* register soft irqs for Host Notify */ 156191ed5349SWolfram Sang res = i2c_setup_host_notify_irq_domain(adap); 156291ed5349SWolfram Sang if (res) { 156391ed5349SWolfram Sang pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n", 156491ed5349SWolfram Sang adap->name, res); 156591ed5349SWolfram Sang goto out_list; 156691ed5349SWolfram Sang } 156791ed5349SWolfram Sang 156891ed5349SWolfram Sang dev_set_name(&adap->dev, "i2c-%d", adap->nr); 156991ed5349SWolfram Sang adap->dev.bus = &i2c_bus_type; 157091ed5349SWolfram Sang adap->dev.type = &i2c_adapter_type; 157191ed5349SWolfram Sang res = device_register(&adap->dev); 157291ed5349SWolfram Sang if (res) { 157391ed5349SWolfram Sang pr_err("adapter '%s': can't register device (%d)\n", adap->name, res); 157491ed5349SWolfram Sang goto out_list; 157591ed5349SWolfram Sang } 157691ed5349SWolfram Sang 1577f8756c67SPhil Reid res = of_i2c_setup_smbus_alert(adap); 1578f8756c67SPhil Reid if (res) 1579f8756c67SPhil Reid goto out_reg; 1580f8756c67SPhil Reid 1581d320ec7aSRajat Jain device_enable_async_suspend(&adap->dev); 158291ed5349SWolfram Sang pm_runtime_no_callbacks(&adap->dev); 158391ed5349SWolfram Sang pm_suspend_ignore_children(&adap->dev, true); 158491ed5349SWolfram Sang pm_runtime_enable(&adap->dev); 158591ed5349SWolfram Sang 158623a698feSCodrin Ciubotariu res = i2c_init_recovery(adap); 158723a698feSCodrin Ciubotariu if (res == -EPROBE_DEFER) 158823a698feSCodrin Ciubotariu goto out_reg; 158923a698feSCodrin Ciubotariu 159023a698feSCodrin Ciubotariu dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); 159123a698feSCodrin Ciubotariu 159291ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 159391ed5349SWolfram Sang res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, 159491ed5349SWolfram Sang adap->dev.parent); 159591ed5349SWolfram Sang if (res) 159691ed5349SWolfram Sang dev_warn(&adap->dev, 159791ed5349SWolfram Sang "Failed to create compatibility class link\n"); 159891ed5349SWolfram Sang #endif 159991ed5349SWolfram Sang 160091ed5349SWolfram Sang /* create pre-declared device nodes */ 160191ed5349SWolfram Sang of_i2c_register_devices(adap); 160291ed5349SWolfram Sang i2c_acpi_install_space_handler(adap); 160321653a41SHans de Goede i2c_acpi_register_devices(adap); 160491ed5349SWolfram Sang 160591ed5349SWolfram Sang if (adap->nr < __i2c_first_dynamic_bus_num) 160691ed5349SWolfram Sang i2c_scan_static_board_info(adap); 160791ed5349SWolfram Sang 160891ed5349SWolfram Sang /* Notify drivers */ 160991ed5349SWolfram Sang mutex_lock(&core_lock); 161091ed5349SWolfram Sang bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); 161191ed5349SWolfram Sang mutex_unlock(&core_lock); 161291ed5349SWolfram Sang 161391ed5349SWolfram Sang return 0; 161491ed5349SWolfram Sang 1615f8756c67SPhil Reid out_reg: 1616f8756c67SPhil Reid init_completion(&adap->dev_released); 1617f8756c67SPhil Reid device_unregister(&adap->dev); 1618f8756c67SPhil Reid wait_for_completion(&adap->dev_released); 161991ed5349SWolfram Sang out_list: 162091ed5349SWolfram Sang mutex_lock(&core_lock); 162191ed5349SWolfram Sang idr_remove(&i2c_adapter_idr, adap->nr); 162291ed5349SWolfram Sang mutex_unlock(&core_lock); 162391ed5349SWolfram Sang return res; 162491ed5349SWolfram Sang } 162591ed5349SWolfram Sang 162691ed5349SWolfram Sang /** 162791ed5349SWolfram Sang * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 162891ed5349SWolfram Sang * @adap: the adapter to register (with adap->nr initialized) 162991ed5349SWolfram Sang * Context: can sleep 163091ed5349SWolfram Sang * 163191ed5349SWolfram Sang * See i2c_add_numbered_adapter() for details. 163291ed5349SWolfram Sang */ 163391ed5349SWolfram Sang static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) 163491ed5349SWolfram Sang { 163591ed5349SWolfram Sang int id; 163691ed5349SWolfram Sang 163791ed5349SWolfram Sang mutex_lock(&core_lock); 163891ed5349SWolfram Sang id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL); 163991ed5349SWolfram Sang mutex_unlock(&core_lock); 164091ed5349SWolfram Sang if (WARN(id < 0, "couldn't get idr")) 164191ed5349SWolfram Sang return id == -ENOSPC ? -EBUSY : id; 164291ed5349SWolfram Sang 164391ed5349SWolfram Sang return i2c_register_adapter(adap); 164491ed5349SWolfram Sang } 164591ed5349SWolfram Sang 164691ed5349SWolfram Sang /** 164791ed5349SWolfram Sang * i2c_add_adapter - declare i2c adapter, use dynamic bus number 164891ed5349SWolfram Sang * @adapter: the adapter to add 164991ed5349SWolfram Sang * Context: can sleep 165091ed5349SWolfram Sang * 165191ed5349SWolfram Sang * This routine is used to declare an I2C adapter when its bus number 165291ed5349SWolfram Sang * doesn't matter or when its bus number is specified by an dt alias. 165391ed5349SWolfram Sang * Examples of bases when the bus number doesn't matter: I2C adapters 165491ed5349SWolfram Sang * dynamically added by USB links or PCI plugin cards. 165591ed5349SWolfram Sang * 165691ed5349SWolfram Sang * When this returns zero, a new bus number was allocated and stored 165791ed5349SWolfram Sang * in adap->nr, and the specified adapter became available for clients. 165891ed5349SWolfram Sang * Otherwise, a negative errno value is returned. 165991ed5349SWolfram Sang */ 166091ed5349SWolfram Sang int i2c_add_adapter(struct i2c_adapter *adapter) 166191ed5349SWolfram Sang { 166291ed5349SWolfram Sang struct device *dev = &adapter->dev; 166391ed5349SWolfram Sang int id; 166491ed5349SWolfram Sang 166591ed5349SWolfram Sang if (dev->of_node) { 166691ed5349SWolfram Sang id = of_alias_get_id(dev->of_node, "i2c"); 166791ed5349SWolfram Sang if (id >= 0) { 166891ed5349SWolfram Sang adapter->nr = id; 166991ed5349SWolfram Sang return __i2c_add_numbered_adapter(adapter); 167091ed5349SWolfram Sang } 167191ed5349SWolfram Sang } 167291ed5349SWolfram Sang 167391ed5349SWolfram Sang mutex_lock(&core_lock); 167491ed5349SWolfram Sang id = idr_alloc(&i2c_adapter_idr, adapter, 167591ed5349SWolfram Sang __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); 167691ed5349SWolfram Sang mutex_unlock(&core_lock); 167791ed5349SWolfram Sang if (WARN(id < 0, "couldn't get idr")) 167891ed5349SWolfram Sang return id; 167991ed5349SWolfram Sang 168091ed5349SWolfram Sang adapter->nr = id; 168191ed5349SWolfram Sang 168291ed5349SWolfram Sang return i2c_register_adapter(adapter); 168391ed5349SWolfram Sang } 168491ed5349SWolfram Sang EXPORT_SYMBOL(i2c_add_adapter); 168591ed5349SWolfram Sang 168691ed5349SWolfram Sang /** 168791ed5349SWolfram Sang * i2c_add_numbered_adapter - declare i2c adapter, use static bus number 168891ed5349SWolfram Sang * @adap: the adapter to register (with adap->nr initialized) 168991ed5349SWolfram Sang * Context: can sleep 169091ed5349SWolfram Sang * 169191ed5349SWolfram Sang * This routine is used to declare an I2C adapter when its bus number 169291ed5349SWolfram Sang * matters. For example, use it for I2C adapters from system-on-chip CPUs, 169391ed5349SWolfram Sang * or otherwise built in to the system's mainboard, and where i2c_board_info 169491ed5349SWolfram Sang * is used to properly configure I2C devices. 169591ed5349SWolfram Sang * 169691ed5349SWolfram Sang * If the requested bus number is set to -1, then this function will behave 169791ed5349SWolfram Sang * identically to i2c_add_adapter, and will dynamically assign a bus number. 169891ed5349SWolfram Sang * 169991ed5349SWolfram Sang * If no devices have pre-been declared for this bus, then be sure to 170091ed5349SWolfram Sang * register the adapter before any dynamically allocated ones. Otherwise 170191ed5349SWolfram Sang * the required bus ID may not be available. 170291ed5349SWolfram Sang * 170391ed5349SWolfram Sang * When this returns zero, the specified adapter became available for 170491ed5349SWolfram Sang * clients using the bus number provided in adap->nr. Also, the table 170591ed5349SWolfram Sang * of I2C devices pre-declared using i2c_register_board_info() is scanned, 170691ed5349SWolfram Sang * and the appropriate driver model device nodes are created. Otherwise, a 170791ed5349SWolfram Sang * negative errno value is returned. 170891ed5349SWolfram Sang */ 170991ed5349SWolfram Sang int i2c_add_numbered_adapter(struct i2c_adapter *adap) 171091ed5349SWolfram Sang { 171191ed5349SWolfram Sang if (adap->nr == -1) /* -1 means dynamically assign bus id */ 171291ed5349SWolfram Sang return i2c_add_adapter(adap); 171391ed5349SWolfram Sang 171491ed5349SWolfram Sang return __i2c_add_numbered_adapter(adap); 171591ed5349SWolfram Sang } 171691ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); 171791ed5349SWolfram Sang 171891ed5349SWolfram Sang static void i2c_do_del_adapter(struct i2c_driver *driver, 171991ed5349SWolfram Sang struct i2c_adapter *adapter) 172091ed5349SWolfram Sang { 172191ed5349SWolfram Sang struct i2c_client *client, *_n; 172291ed5349SWolfram Sang 172391ed5349SWolfram Sang /* Remove the devices we created ourselves as the result of hardware 172491ed5349SWolfram Sang * probing (using a driver's detect method) */ 172591ed5349SWolfram Sang list_for_each_entry_safe(client, _n, &driver->clients, detected) { 172691ed5349SWolfram Sang if (client->adapter == adapter) { 172791ed5349SWolfram Sang dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", 172891ed5349SWolfram Sang client->name, client->addr); 172991ed5349SWolfram Sang list_del(&client->detected); 173091ed5349SWolfram Sang i2c_unregister_device(client); 173191ed5349SWolfram Sang } 173291ed5349SWolfram Sang } 173391ed5349SWolfram Sang } 173491ed5349SWolfram Sang 173591ed5349SWolfram Sang static int __unregister_client(struct device *dev, void *dummy) 173691ed5349SWolfram Sang { 173791ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 173891ed5349SWolfram Sang if (client && strcmp(client->name, "dummy")) 173991ed5349SWolfram Sang i2c_unregister_device(client); 174091ed5349SWolfram Sang return 0; 174191ed5349SWolfram Sang } 174291ed5349SWolfram Sang 174391ed5349SWolfram Sang static int __unregister_dummy(struct device *dev, void *dummy) 174491ed5349SWolfram Sang { 174591ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 174691ed5349SWolfram Sang i2c_unregister_device(client); 174791ed5349SWolfram Sang return 0; 174891ed5349SWolfram Sang } 174991ed5349SWolfram Sang 175091ed5349SWolfram Sang static int __process_removed_adapter(struct device_driver *d, void *data) 175191ed5349SWolfram Sang { 175291ed5349SWolfram Sang i2c_do_del_adapter(to_i2c_driver(d), data); 175391ed5349SWolfram Sang return 0; 175491ed5349SWolfram Sang } 175591ed5349SWolfram Sang 175691ed5349SWolfram Sang /** 175791ed5349SWolfram Sang * i2c_del_adapter - unregister I2C adapter 175891ed5349SWolfram Sang * @adap: the adapter being unregistered 175991ed5349SWolfram Sang * Context: can sleep 176091ed5349SWolfram Sang * 176191ed5349SWolfram Sang * This unregisters an I2C adapter which was previously registered 176291ed5349SWolfram Sang * by @i2c_add_adapter or @i2c_add_numbered_adapter. 176391ed5349SWolfram Sang */ 176491ed5349SWolfram Sang void i2c_del_adapter(struct i2c_adapter *adap) 176591ed5349SWolfram Sang { 176691ed5349SWolfram Sang struct i2c_adapter *found; 176791ed5349SWolfram Sang struct i2c_client *client, *next; 176891ed5349SWolfram Sang 176991ed5349SWolfram Sang /* First make sure that this adapter was ever added */ 177091ed5349SWolfram Sang mutex_lock(&core_lock); 177191ed5349SWolfram Sang found = idr_find(&i2c_adapter_idr, adap->nr); 177291ed5349SWolfram Sang mutex_unlock(&core_lock); 177391ed5349SWolfram Sang if (found != adap) { 177491ed5349SWolfram Sang pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name); 177591ed5349SWolfram Sang return; 177691ed5349SWolfram Sang } 177791ed5349SWolfram Sang 177891ed5349SWolfram Sang i2c_acpi_remove_space_handler(adap); 177991ed5349SWolfram Sang /* Tell drivers about this removal */ 178091ed5349SWolfram Sang mutex_lock(&core_lock); 178191ed5349SWolfram Sang bus_for_each_drv(&i2c_bus_type, NULL, adap, 178291ed5349SWolfram Sang __process_removed_adapter); 178391ed5349SWolfram Sang mutex_unlock(&core_lock); 178491ed5349SWolfram Sang 178591ed5349SWolfram Sang /* Remove devices instantiated from sysfs */ 178691ed5349SWolfram Sang mutex_lock_nested(&adap->userspace_clients_lock, 178791ed5349SWolfram Sang i2c_adapter_depth(adap)); 178891ed5349SWolfram Sang list_for_each_entry_safe(client, next, &adap->userspace_clients, 178991ed5349SWolfram Sang detected) { 179091ed5349SWolfram Sang dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, 179191ed5349SWolfram Sang client->addr); 179291ed5349SWolfram Sang list_del(&client->detected); 179391ed5349SWolfram Sang i2c_unregister_device(client); 179491ed5349SWolfram Sang } 179591ed5349SWolfram Sang mutex_unlock(&adap->userspace_clients_lock); 179691ed5349SWolfram Sang 179791ed5349SWolfram Sang /* Detach any active clients. This can't fail, thus we do not 179891ed5349SWolfram Sang * check the returned value. This is a two-pass process, because 179991ed5349SWolfram Sang * we can't remove the dummy devices during the first pass: they 180091ed5349SWolfram Sang * could have been instantiated by real devices wishing to clean 180191ed5349SWolfram Sang * them up properly, so we give them a chance to do that first. */ 180291ed5349SWolfram Sang device_for_each_child(&adap->dev, NULL, __unregister_client); 180391ed5349SWolfram Sang device_for_each_child(&adap->dev, NULL, __unregister_dummy); 180491ed5349SWolfram Sang 180591ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 180691ed5349SWolfram Sang class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, 180791ed5349SWolfram Sang adap->dev.parent); 180891ed5349SWolfram Sang #endif 180991ed5349SWolfram Sang 181091ed5349SWolfram Sang /* device name is gone after device_unregister */ 181191ed5349SWolfram Sang dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); 181291ed5349SWolfram Sang 181391ed5349SWolfram Sang pm_runtime_disable(&adap->dev); 181491ed5349SWolfram Sang 181591ed5349SWolfram Sang i2c_host_notify_irq_teardown(adap); 181691ed5349SWolfram Sang 181791ed5349SWolfram Sang /* wait until all references to the device are gone 181891ed5349SWolfram Sang * 181991ed5349SWolfram Sang * FIXME: This is old code and should ideally be replaced by an 182091ed5349SWolfram Sang * alternative which results in decoupling the lifetime of the struct 182191ed5349SWolfram Sang * device from the i2c_adapter, like spi or netdev do. Any solution 182291ed5349SWolfram Sang * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled! 182391ed5349SWolfram Sang */ 182491ed5349SWolfram Sang init_completion(&adap->dev_released); 182591ed5349SWolfram Sang device_unregister(&adap->dev); 182691ed5349SWolfram Sang wait_for_completion(&adap->dev_released); 182791ed5349SWolfram Sang 182891ed5349SWolfram Sang /* free bus id */ 182991ed5349SWolfram Sang mutex_lock(&core_lock); 183091ed5349SWolfram Sang idr_remove(&i2c_adapter_idr, adap->nr); 183191ed5349SWolfram Sang mutex_unlock(&core_lock); 183291ed5349SWolfram Sang 183391ed5349SWolfram Sang /* Clear the device structure in case this adapter is ever going to be 183491ed5349SWolfram Sang added again */ 183591ed5349SWolfram Sang memset(&adap->dev, 0, sizeof(adap->dev)); 183691ed5349SWolfram Sang } 183791ed5349SWolfram Sang EXPORT_SYMBOL(i2c_del_adapter); 183891ed5349SWolfram Sang 183907740c92SYicong Yang static void devm_i2c_del_adapter(void *adapter) 184007740c92SYicong Yang { 184107740c92SYicong Yang i2c_del_adapter(adapter); 184207740c92SYicong Yang } 184307740c92SYicong Yang 184407740c92SYicong Yang /** 184507740c92SYicong Yang * devm_i2c_add_adapter - device-managed variant of i2c_add_adapter() 184607740c92SYicong Yang * @dev: managing device for adding this I2C adapter 184707740c92SYicong Yang * @adapter: the adapter to add 184807740c92SYicong Yang * Context: can sleep 184907740c92SYicong Yang * 185007740c92SYicong Yang * Add adapter with dynamic bus number, same with i2c_add_adapter() 185107740c92SYicong Yang * but the adapter will be auto deleted on driver detach. 185207740c92SYicong Yang */ 185307740c92SYicong Yang int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter) 185407740c92SYicong Yang { 185507740c92SYicong Yang int ret; 185607740c92SYicong Yang 185707740c92SYicong Yang ret = i2c_add_adapter(adapter); 185807740c92SYicong Yang if (ret) 185907740c92SYicong Yang return ret; 186007740c92SYicong Yang 186107740c92SYicong Yang return devm_add_action_or_reset(dev, devm_i2c_del_adapter, adapter); 186207740c92SYicong Yang } 186307740c92SYicong Yang EXPORT_SYMBOL_GPL(devm_i2c_add_adapter); 186407740c92SYicong Yang 1865def00b32SWolfram Sang static void i2c_parse_timing(struct device *dev, char *prop_name, u32 *cur_val_p, 1866def00b32SWolfram Sang u32 def_val, bool use_def) 1867def00b32SWolfram Sang { 1868def00b32SWolfram Sang int ret; 1869def00b32SWolfram Sang 1870def00b32SWolfram Sang ret = device_property_read_u32(dev, prop_name, cur_val_p); 1871def00b32SWolfram Sang if (ret && use_def) 1872def00b32SWolfram Sang *cur_val_p = def_val; 1873def00b32SWolfram Sang 1874def00b32SWolfram Sang dev_dbg(dev, "%s: %u\n", prop_name, *cur_val_p); 1875def00b32SWolfram Sang } 1876def00b32SWolfram Sang 187791ed5349SWolfram Sang /** 187891ed5349SWolfram Sang * i2c_parse_fw_timings - get I2C related timing parameters from firmware 187991ed5349SWolfram Sang * @dev: The device to scan for I2C timing properties 188091ed5349SWolfram Sang * @t: the i2c_timings struct to be filled with values 188191ed5349SWolfram Sang * @use_defaults: bool to use sane defaults derived from the I2C specification 1882263a5646SAndy Shevchenko * when properties are not found, otherwise don't update 188391ed5349SWolfram Sang * 188491ed5349SWolfram Sang * Scan the device for the generic I2C properties describing timing parameters 188591ed5349SWolfram Sang * for the signal and fill the given struct with the results. If a property was 188691ed5349SWolfram Sang * not found and use_defaults was true, then maximum timings are assumed which 188791ed5349SWolfram Sang * are derived from the I2C specification. If use_defaults is not used, the 1888263a5646SAndy Shevchenko * results will be as before, so drivers can apply their own defaults before 1889263a5646SAndy Shevchenko * calling this helper. The latter is mainly intended for avoiding regressions 1890263a5646SAndy Shevchenko * of existing drivers which want to switch to this function. New drivers 1891263a5646SAndy Shevchenko * almost always should use the defaults. 189291ed5349SWolfram Sang */ 189391ed5349SWolfram Sang void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults) 189491ed5349SWolfram Sang { 1895def00b32SWolfram Sang bool u = use_defaults; 1896def00b32SWolfram Sang u32 d; 189791ed5349SWolfram Sang 1898def00b32SWolfram Sang i2c_parse_timing(dev, "clock-frequency", &t->bus_freq_hz, 1899def00b32SWolfram Sang I2C_MAX_STANDARD_MODE_FREQ, u); 190091ed5349SWolfram Sang 1901def00b32SWolfram Sang d = t->bus_freq_hz <= I2C_MAX_STANDARD_MODE_FREQ ? 1000 : 1902def00b32SWolfram Sang t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120; 1903def00b32SWolfram Sang i2c_parse_timing(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns, d, u); 190491ed5349SWolfram Sang 1905def00b32SWolfram Sang d = t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120; 1906def00b32SWolfram Sang i2c_parse_timing(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns, d, u); 190791ed5349SWolfram Sang 1908def00b32SWolfram Sang i2c_parse_timing(dev, "i2c-scl-internal-delay-ns", 1909def00b32SWolfram Sang &t->scl_int_delay_ns, 0, u); 1910def00b32SWolfram Sang i2c_parse_timing(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns, 1911def00b32SWolfram Sang t->scl_fall_ns, u); 1912def00b32SWolfram Sang i2c_parse_timing(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns, 0, u); 1913def00b32SWolfram Sang i2c_parse_timing(dev, "i2c-digital-filter-width-ns", 1914def00b32SWolfram Sang &t->digital_filter_width_ns, 0, u); 1915def00b32SWolfram Sang i2c_parse_timing(dev, "i2c-analog-filter-cutoff-frequency", 1916def00b32SWolfram Sang &t->analog_filter_cutoff_freq_hz, 0, u); 191791ed5349SWolfram Sang } 191891ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_parse_fw_timings); 191991ed5349SWolfram Sang 192091ed5349SWolfram Sang /* ------------------------------------------------------------------------- */ 192191ed5349SWolfram Sang 1922edd7a563SWolfram Sang int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data)) 192391ed5349SWolfram Sang { 192491ed5349SWolfram Sang int res; 192591ed5349SWolfram Sang 192691ed5349SWolfram Sang mutex_lock(&core_lock); 192791ed5349SWolfram Sang res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); 192891ed5349SWolfram Sang mutex_unlock(&core_lock); 192991ed5349SWolfram Sang 193091ed5349SWolfram Sang return res; 193191ed5349SWolfram Sang } 193291ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_for_each_dev); 193391ed5349SWolfram Sang 193491ed5349SWolfram Sang static int __process_new_driver(struct device *dev, void *data) 193591ed5349SWolfram Sang { 193691ed5349SWolfram Sang if (dev->type != &i2c_adapter_type) 193791ed5349SWolfram Sang return 0; 193891ed5349SWolfram Sang return i2c_do_add_adapter(data, to_i2c_adapter(dev)); 193991ed5349SWolfram Sang } 194091ed5349SWolfram Sang 194191ed5349SWolfram Sang /* 194291ed5349SWolfram Sang * An i2c_driver is used with one or more i2c_client (device) nodes to access 194391ed5349SWolfram Sang * i2c slave chips, on a bus instance associated with some i2c_adapter. 194491ed5349SWolfram Sang */ 194591ed5349SWolfram Sang 194691ed5349SWolfram Sang int i2c_register_driver(struct module *owner, struct i2c_driver *driver) 194791ed5349SWolfram Sang { 194891ed5349SWolfram Sang int res; 194991ed5349SWolfram Sang 195091ed5349SWolfram Sang /* Can't register until after driver model init */ 195191ed5349SWolfram Sang if (WARN_ON(!is_registered)) 195291ed5349SWolfram Sang return -EAGAIN; 195391ed5349SWolfram Sang 195491ed5349SWolfram Sang /* add the driver to the list of i2c drivers in the driver core */ 195591ed5349SWolfram Sang driver->driver.owner = owner; 195691ed5349SWolfram Sang driver->driver.bus = &i2c_bus_type; 195791ed5349SWolfram Sang INIT_LIST_HEAD(&driver->clients); 195891ed5349SWolfram Sang 195991ed5349SWolfram Sang /* When registration returns, the driver core 196091ed5349SWolfram Sang * will have called probe() for all matching-but-unbound devices. 196191ed5349SWolfram Sang */ 196291ed5349SWolfram Sang res = driver_register(&driver->driver); 196391ed5349SWolfram Sang if (res) 196491ed5349SWolfram Sang return res; 196591ed5349SWolfram Sang 196691ed5349SWolfram Sang pr_debug("driver [%s] registered\n", driver->driver.name); 196791ed5349SWolfram Sang 196891ed5349SWolfram Sang /* Walk the adapters that are already present */ 196991ed5349SWolfram Sang i2c_for_each_dev(driver, __process_new_driver); 197091ed5349SWolfram Sang 197191ed5349SWolfram Sang return 0; 197291ed5349SWolfram Sang } 197391ed5349SWolfram Sang EXPORT_SYMBOL(i2c_register_driver); 197491ed5349SWolfram Sang 197591ed5349SWolfram Sang static int __process_removed_driver(struct device *dev, void *data) 197691ed5349SWolfram Sang { 197791ed5349SWolfram Sang if (dev->type == &i2c_adapter_type) 197891ed5349SWolfram Sang i2c_do_del_adapter(data, to_i2c_adapter(dev)); 197991ed5349SWolfram Sang return 0; 198091ed5349SWolfram Sang } 198191ed5349SWolfram Sang 198291ed5349SWolfram Sang /** 198391ed5349SWolfram Sang * i2c_del_driver - unregister I2C driver 198491ed5349SWolfram Sang * @driver: the driver being unregistered 198591ed5349SWolfram Sang * Context: can sleep 198691ed5349SWolfram Sang */ 198791ed5349SWolfram Sang void i2c_del_driver(struct i2c_driver *driver) 198891ed5349SWolfram Sang { 198991ed5349SWolfram Sang i2c_for_each_dev(driver, __process_removed_driver); 199091ed5349SWolfram Sang 199191ed5349SWolfram Sang driver_unregister(&driver->driver); 199291ed5349SWolfram Sang pr_debug("driver [%s] unregistered\n", driver->driver.name); 199391ed5349SWolfram Sang } 199491ed5349SWolfram Sang EXPORT_SYMBOL(i2c_del_driver); 199591ed5349SWolfram Sang 199691ed5349SWolfram Sang /* ------------------------------------------------------------------------- */ 199791ed5349SWolfram Sang 199891ed5349SWolfram Sang struct i2c_cmd_arg { 199991ed5349SWolfram Sang unsigned cmd; 200091ed5349SWolfram Sang void *arg; 200191ed5349SWolfram Sang }; 200291ed5349SWolfram Sang 200391ed5349SWolfram Sang static int i2c_cmd(struct device *dev, void *_arg) 200491ed5349SWolfram Sang { 200591ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 200691ed5349SWolfram Sang struct i2c_cmd_arg *arg = _arg; 200791ed5349SWolfram Sang struct i2c_driver *driver; 200891ed5349SWolfram Sang 200991ed5349SWolfram Sang if (!client || !client->dev.driver) 201091ed5349SWolfram Sang return 0; 201191ed5349SWolfram Sang 201291ed5349SWolfram Sang driver = to_i2c_driver(client->dev.driver); 201391ed5349SWolfram Sang if (driver->command) 201491ed5349SWolfram Sang driver->command(client, arg->cmd, arg->arg); 201591ed5349SWolfram Sang return 0; 201691ed5349SWolfram Sang } 201791ed5349SWolfram Sang 201891ed5349SWolfram Sang void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) 201991ed5349SWolfram Sang { 202091ed5349SWolfram Sang struct i2c_cmd_arg cmd_arg; 202191ed5349SWolfram Sang 202291ed5349SWolfram Sang cmd_arg.cmd = cmd; 202391ed5349SWolfram Sang cmd_arg.arg = arg; 202491ed5349SWolfram Sang device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); 202591ed5349SWolfram Sang } 202691ed5349SWolfram Sang EXPORT_SYMBOL(i2c_clients_command); 202791ed5349SWolfram Sang 202891ed5349SWolfram Sang static int __init i2c_init(void) 202991ed5349SWolfram Sang { 203091ed5349SWolfram Sang int retval; 203191ed5349SWolfram Sang 203291ed5349SWolfram Sang retval = of_alias_get_highest_id("i2c"); 203391ed5349SWolfram Sang 203491ed5349SWolfram Sang down_write(&__i2c_board_lock); 203591ed5349SWolfram Sang if (retval >= __i2c_first_dynamic_bus_num) 203691ed5349SWolfram Sang __i2c_first_dynamic_bus_num = retval + 1; 203791ed5349SWolfram Sang up_write(&__i2c_board_lock); 203891ed5349SWolfram Sang 203991ed5349SWolfram Sang retval = bus_register(&i2c_bus_type); 204091ed5349SWolfram Sang if (retval) 204191ed5349SWolfram Sang return retval; 204291ed5349SWolfram Sang 204391ed5349SWolfram Sang is_registered = true; 204491ed5349SWolfram Sang 204591ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 204691ed5349SWolfram Sang i2c_adapter_compat_class = class_compat_register("i2c-adapter"); 204791ed5349SWolfram Sang if (!i2c_adapter_compat_class) { 204891ed5349SWolfram Sang retval = -ENOMEM; 204991ed5349SWolfram Sang goto bus_err; 205091ed5349SWolfram Sang } 205191ed5349SWolfram Sang #endif 205291ed5349SWolfram Sang retval = i2c_add_driver(&dummy_driver); 205391ed5349SWolfram Sang if (retval) 205491ed5349SWolfram Sang goto class_err; 205591ed5349SWolfram Sang 205691ed5349SWolfram Sang if (IS_ENABLED(CONFIG_OF_DYNAMIC)) 205791ed5349SWolfram Sang WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier)); 205891ed5349SWolfram Sang if (IS_ENABLED(CONFIG_ACPI)) 205991ed5349SWolfram Sang WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier)); 206091ed5349SWolfram Sang 206191ed5349SWolfram Sang return 0; 206291ed5349SWolfram Sang 206391ed5349SWolfram Sang class_err: 206491ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 206591ed5349SWolfram Sang class_compat_unregister(i2c_adapter_compat_class); 206691ed5349SWolfram Sang bus_err: 206791ed5349SWolfram Sang #endif 206891ed5349SWolfram Sang is_registered = false; 206991ed5349SWolfram Sang bus_unregister(&i2c_bus_type); 207091ed5349SWolfram Sang return retval; 207191ed5349SWolfram Sang } 207291ed5349SWolfram Sang 207391ed5349SWolfram Sang static void __exit i2c_exit(void) 207491ed5349SWolfram Sang { 207591ed5349SWolfram Sang if (IS_ENABLED(CONFIG_ACPI)) 207691ed5349SWolfram Sang WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier)); 207791ed5349SWolfram Sang if (IS_ENABLED(CONFIG_OF_DYNAMIC)) 207891ed5349SWolfram Sang WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier)); 207991ed5349SWolfram Sang i2c_del_driver(&dummy_driver); 208091ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 208191ed5349SWolfram Sang class_compat_unregister(i2c_adapter_compat_class); 208291ed5349SWolfram Sang #endif 208391ed5349SWolfram Sang bus_unregister(&i2c_bus_type); 208491ed5349SWolfram Sang tracepoint_synchronize_unregister(); 208591ed5349SWolfram Sang } 208691ed5349SWolfram Sang 208791ed5349SWolfram Sang /* We must initialize early, because some subsystems register i2c drivers 208891ed5349SWolfram Sang * in subsys_initcall() code, but are linked (and initialized) before i2c. 208991ed5349SWolfram Sang */ 209091ed5349SWolfram Sang postcore_initcall(i2c_init); 209191ed5349SWolfram Sang module_exit(i2c_exit); 209291ed5349SWolfram Sang 209391ed5349SWolfram Sang /* ---------------------------------------------------- 209491ed5349SWolfram Sang * the functional interface to the i2c busses. 209591ed5349SWolfram Sang * ---------------------------------------------------- 209691ed5349SWolfram Sang */ 209791ed5349SWolfram Sang 209891ed5349SWolfram Sang /* Check if val is exceeding the quirk IFF quirk is non 0 */ 209991ed5349SWolfram Sang #define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk))) 210091ed5349SWolfram Sang 210191ed5349SWolfram Sang static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg) 210291ed5349SWolfram Sang { 210391ed5349SWolfram Sang dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n", 210491ed5349SWolfram Sang err_msg, msg->addr, msg->len, 210591ed5349SWolfram Sang msg->flags & I2C_M_RD ? "read" : "write"); 210691ed5349SWolfram Sang return -EOPNOTSUPP; 210791ed5349SWolfram Sang } 210891ed5349SWolfram Sang 210991ed5349SWolfram Sang static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) 211091ed5349SWolfram Sang { 211191ed5349SWolfram Sang const struct i2c_adapter_quirks *q = adap->quirks; 211291ed5349SWolfram Sang int max_num = q->max_num_msgs, i; 211391ed5349SWolfram Sang bool do_len_check = true; 211491ed5349SWolfram Sang 211591ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB) { 211691ed5349SWolfram Sang max_num = 2; 211791ed5349SWolfram Sang 211891ed5349SWolfram Sang /* special checks for combined messages */ 211991ed5349SWolfram Sang if (num == 2) { 212091ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD) 212191ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write"); 212291ed5349SWolfram Sang 212391ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD)) 212491ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read"); 212591ed5349SWolfram Sang 212691ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr) 212791ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr"); 212891ed5349SWolfram Sang 212991ed5349SWolfram Sang if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len)) 213091ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "msg too long"); 213191ed5349SWolfram Sang 213291ed5349SWolfram Sang if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len)) 213391ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[1], "msg too long"); 213491ed5349SWolfram Sang 213591ed5349SWolfram Sang do_len_check = false; 213691ed5349SWolfram Sang } 213791ed5349SWolfram Sang } 213891ed5349SWolfram Sang 213991ed5349SWolfram Sang if (i2c_quirk_exceeded(num, max_num)) 214091ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "too many messages"); 214191ed5349SWolfram Sang 214291ed5349SWolfram Sang for (i = 0; i < num; i++) { 214391ed5349SWolfram Sang u16 len = msgs[i].len; 214491ed5349SWolfram Sang 214591ed5349SWolfram Sang if (msgs[i].flags & I2C_M_RD) { 214691ed5349SWolfram Sang if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len)) 214791ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[i], "msg too long"); 2148d9cfe2ceSWolfram Sang 2149d9cfe2ceSWolfram Sang if (q->flags & I2C_AQ_NO_ZERO_LEN_READ && len == 0) 2150d9cfe2ceSWolfram Sang return i2c_quirk_error(adap, &msgs[i], "no zero length"); 215191ed5349SWolfram Sang } else { 215291ed5349SWolfram Sang if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len)) 215391ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[i], "msg too long"); 2154d9cfe2ceSWolfram Sang 2155d9cfe2ceSWolfram Sang if (q->flags & I2C_AQ_NO_ZERO_LEN_WRITE && len == 0) 2156d9cfe2ceSWolfram Sang return i2c_quirk_error(adap, &msgs[i], "no zero length"); 215791ed5349SWolfram Sang } 215891ed5349SWolfram Sang } 215991ed5349SWolfram Sang 216091ed5349SWolfram Sang return 0; 216191ed5349SWolfram Sang } 216291ed5349SWolfram Sang 216391ed5349SWolfram Sang /** 216491ed5349SWolfram Sang * __i2c_transfer - unlocked flavor of i2c_transfer 216591ed5349SWolfram Sang * @adap: Handle to I2C bus 216691ed5349SWolfram Sang * @msgs: One or more messages to execute before STOP is issued to 216791ed5349SWolfram Sang * terminate the operation; each message begins with a START. 216891ed5349SWolfram Sang * @num: Number of messages to be executed. 216991ed5349SWolfram Sang * 217091ed5349SWolfram Sang * Returns negative errno, else the number of messages executed. 217191ed5349SWolfram Sang * 217291ed5349SWolfram Sang * Adapter lock must be held when calling this function. No debug logging 217391ed5349SWolfram Sang * takes place. adap->algo->master_xfer existence isn't checked. 217491ed5349SWolfram Sang */ 217591ed5349SWolfram Sang int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) 217691ed5349SWolfram Sang { 217791ed5349SWolfram Sang unsigned long orig_jiffies; 217891ed5349SWolfram Sang int ret, try; 217991ed5349SWolfram Sang 21801eace834SArd Biesheuvel if (WARN_ON(!msgs || num < 1)) 21811eace834SArd Biesheuvel return -EINVAL; 21825d756112SWolfram Sang 21835d756112SWolfram Sang ret = __i2c_check_suspended(adap); 21845d756112SWolfram Sang if (ret) 21855d756112SWolfram Sang return ret; 21861eace834SArd Biesheuvel 218791ed5349SWolfram Sang if (adap->quirks && i2c_check_for_quirks(adap, msgs, num)) 218891ed5349SWolfram Sang return -EOPNOTSUPP; 218991ed5349SWolfram Sang 219050888b01SDavidlohr Bueso /* 219150888b01SDavidlohr Bueso * i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets 219291ed5349SWolfram Sang * enabled. This is an efficient way of keeping the for-loop from 219391ed5349SWolfram Sang * being executed when not needed. 219491ed5349SWolfram Sang */ 219550888b01SDavidlohr Bueso if (static_branch_unlikely(&i2c_trace_msg_key)) { 219691ed5349SWolfram Sang int i; 219791ed5349SWolfram Sang for (i = 0; i < num; i++) 219891ed5349SWolfram Sang if (msgs[i].flags & I2C_M_RD) 219991ed5349SWolfram Sang trace_i2c_read(adap, &msgs[i], i); 220091ed5349SWolfram Sang else 220191ed5349SWolfram Sang trace_i2c_write(adap, &msgs[i], i); 220291ed5349SWolfram Sang } 220391ed5349SWolfram Sang 220491ed5349SWolfram Sang /* Retry automatically on arbitration loss */ 220591ed5349SWolfram Sang orig_jiffies = jiffies; 220691ed5349SWolfram Sang for (ret = 0, try = 0; try <= adap->retries; try++) { 220763b96983SWolfram Sang if (i2c_in_atomic_xfer_mode() && adap->algo->master_xfer_atomic) 220863b96983SWolfram Sang ret = adap->algo->master_xfer_atomic(adap, msgs, num); 220963b96983SWolfram Sang else 221091ed5349SWolfram Sang ret = adap->algo->master_xfer(adap, msgs, num); 221163b96983SWolfram Sang 221291ed5349SWolfram Sang if (ret != -EAGAIN) 221391ed5349SWolfram Sang break; 221491ed5349SWolfram Sang if (time_after(jiffies, orig_jiffies + adap->timeout)) 221591ed5349SWolfram Sang break; 221691ed5349SWolfram Sang } 221791ed5349SWolfram Sang 221850888b01SDavidlohr Bueso if (static_branch_unlikely(&i2c_trace_msg_key)) { 221991ed5349SWolfram Sang int i; 222091ed5349SWolfram Sang for (i = 0; i < ret; i++) 222191ed5349SWolfram Sang if (msgs[i].flags & I2C_M_RD) 222291ed5349SWolfram Sang trace_i2c_reply(adap, &msgs[i], i); 22234a3f7691SAhbong Chang trace_i2c_result(adap, num, ret); 222491ed5349SWolfram Sang } 222591ed5349SWolfram Sang 222691ed5349SWolfram Sang return ret; 222791ed5349SWolfram Sang } 222891ed5349SWolfram Sang EXPORT_SYMBOL(__i2c_transfer); 222991ed5349SWolfram Sang 223091ed5349SWolfram Sang /** 223191ed5349SWolfram Sang * i2c_transfer - execute a single or combined I2C message 223291ed5349SWolfram Sang * @adap: Handle to I2C bus 223391ed5349SWolfram Sang * @msgs: One or more messages to execute before STOP is issued to 223491ed5349SWolfram Sang * terminate the operation; each message begins with a START. 223591ed5349SWolfram Sang * @num: Number of messages to be executed. 223691ed5349SWolfram Sang * 223791ed5349SWolfram Sang * Returns negative errno, else the number of messages executed. 223891ed5349SWolfram Sang * 223991ed5349SWolfram Sang * Note that there is no requirement that each message be sent to 224091ed5349SWolfram Sang * the same slave address, although that is the most common model. 224191ed5349SWolfram Sang */ 224291ed5349SWolfram Sang int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) 224391ed5349SWolfram Sang { 224491ed5349SWolfram Sang int ret; 224591ed5349SWolfram Sang 2246cc52612eSWolfram Sang if (!adap->algo->master_xfer) { 2247cc52612eSWolfram Sang dev_dbg(&adap->dev, "I2C level transfers not supported\n"); 2248cc52612eSWolfram Sang return -EOPNOTSUPP; 2249cc52612eSWolfram Sang } 2250cc52612eSWolfram Sang 225191ed5349SWolfram Sang /* REVISIT the fault reporting model here is weak: 225291ed5349SWolfram Sang * 225391ed5349SWolfram Sang * - When we get an error after receiving N bytes from a slave, 225491ed5349SWolfram Sang * there is no way to report "N". 225591ed5349SWolfram Sang * 225691ed5349SWolfram Sang * - When we get a NAK after transmitting N bytes to a slave, 225791ed5349SWolfram Sang * there is no way to report "N" ... or to let the master 225891ed5349SWolfram Sang * continue executing the rest of this combined message, if 225991ed5349SWolfram Sang * that's the appropriate response. 226091ed5349SWolfram Sang * 226191ed5349SWolfram Sang * - When for example "num" is two and we successfully complete 226291ed5349SWolfram Sang * the first message but get an error part way through the 226391ed5349SWolfram Sang * second, it's unclear whether that should be reported as 226491ed5349SWolfram Sang * one (discarding status on the second message) or errno 226591ed5349SWolfram Sang * (discarding status on the first one). 226691ed5349SWolfram Sang */ 226783c42212SWolfram Sang ret = __i2c_lock_bus_helper(adap); 226883c42212SWolfram Sang if (ret) 226983c42212SWolfram Sang return ret; 227091ed5349SWolfram Sang 227191ed5349SWolfram Sang ret = __i2c_transfer(adap, msgs, num); 227291ed5349SWolfram Sang i2c_unlock_bus(adap, I2C_LOCK_SEGMENT); 227391ed5349SWolfram Sang 227491ed5349SWolfram Sang return ret; 227591ed5349SWolfram Sang } 227691ed5349SWolfram Sang EXPORT_SYMBOL(i2c_transfer); 227791ed5349SWolfram Sang 227891ed5349SWolfram Sang /** 22798a91732bSWolfram Sang * i2c_transfer_buffer_flags - issue a single I2C message transferring data 22808a91732bSWolfram Sang * to/from a buffer 228191ed5349SWolfram Sang * @client: Handle to slave device 22828a91732bSWolfram Sang * @buf: Where the data is stored 22838a91732bSWolfram Sang * @count: How many bytes to transfer, must be less than 64k since msg.len is u16 22848a91732bSWolfram Sang * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads 228591ed5349SWolfram Sang * 22868a91732bSWolfram Sang * Returns negative errno, or else the number of bytes transferred. 228791ed5349SWolfram Sang */ 22888a91732bSWolfram Sang int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf, 22898a91732bSWolfram Sang int count, u16 flags) 229091ed5349SWolfram Sang { 229191ed5349SWolfram Sang int ret; 22928a91732bSWolfram Sang struct i2c_msg msg = { 22938a91732bSWolfram Sang .addr = client->addr, 22948a91732bSWolfram Sang .flags = flags | (client->flags & I2C_M_TEN), 22958a91732bSWolfram Sang .len = count, 22968a91732bSWolfram Sang .buf = buf, 22978a91732bSWolfram Sang }; 229891ed5349SWolfram Sang 22998a91732bSWolfram Sang ret = i2c_transfer(client->adapter, &msg, 1); 230091ed5349SWolfram Sang 230191ed5349SWolfram Sang /* 23028a91732bSWolfram Sang * If everything went ok (i.e. 1 msg transferred), return #bytes 23038a91732bSWolfram Sang * transferred, else error code. 230491ed5349SWolfram Sang */ 230591ed5349SWolfram Sang return (ret == 1) ? count : ret; 230691ed5349SWolfram Sang } 23078a91732bSWolfram Sang EXPORT_SYMBOL(i2c_transfer_buffer_flags); 230891ed5349SWolfram Sang 2309dde67eb1SPeter Rosin /** 2310dde67eb1SPeter Rosin * i2c_get_device_id - get manufacturer, part id and die revision of a device 2311dde67eb1SPeter Rosin * @client: The device to query 2312dde67eb1SPeter Rosin * @id: The queried information 2313dde67eb1SPeter Rosin * 2314dde67eb1SPeter Rosin * Returns negative errno on error, zero on success. 2315dde67eb1SPeter Rosin */ 2316dde67eb1SPeter Rosin int i2c_get_device_id(const struct i2c_client *client, 2317dde67eb1SPeter Rosin struct i2c_device_identity *id) 2318dde67eb1SPeter Rosin { 2319dde67eb1SPeter Rosin struct i2c_adapter *adap = client->adapter; 2320dde67eb1SPeter Rosin union i2c_smbus_data raw_id; 2321dde67eb1SPeter Rosin int ret; 2322dde67eb1SPeter Rosin 2323dde67eb1SPeter Rosin if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) 2324dde67eb1SPeter Rosin return -EOPNOTSUPP; 2325dde67eb1SPeter Rosin 2326dde67eb1SPeter Rosin raw_id.block[0] = 3; 2327dde67eb1SPeter Rosin ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0, 2328dde67eb1SPeter Rosin I2C_SMBUS_READ, client->addr << 1, 2329dde67eb1SPeter Rosin I2C_SMBUS_I2C_BLOCK_DATA, &raw_id); 2330dde67eb1SPeter Rosin if (ret) 2331dde67eb1SPeter Rosin return ret; 2332dde67eb1SPeter Rosin 2333dde67eb1SPeter Rosin id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4); 2334dde67eb1SPeter Rosin id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3); 2335dde67eb1SPeter Rosin id->die_revision = raw_id.block[3] & 0x7; 2336dde67eb1SPeter Rosin return 0; 2337dde67eb1SPeter Rosin } 2338dde67eb1SPeter Rosin EXPORT_SYMBOL_GPL(i2c_get_device_id); 2339dde67eb1SPeter Rosin 234091ed5349SWolfram Sang /* ---------------------------------------------------- 234191ed5349SWolfram Sang * the i2c address scanning function 234291ed5349SWolfram Sang * Will not work for 10-bit addresses! 234391ed5349SWolfram Sang * ---------------------------------------------------- 234491ed5349SWolfram Sang */ 234591ed5349SWolfram Sang 234691ed5349SWolfram Sang /* 234791ed5349SWolfram Sang * Legacy default probe function, mostly relevant for SMBus. The default 234891ed5349SWolfram Sang * probe method is a quick write, but it is known to corrupt the 24RF08 234991ed5349SWolfram Sang * EEPROMs due to a state machine bug, and could also irreversibly 235091ed5349SWolfram Sang * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, 235191ed5349SWolfram Sang * we use a short byte read instead. Also, some bus drivers don't implement 235291ed5349SWolfram Sang * quick write, so we fallback to a byte read in that case too. 235391ed5349SWolfram Sang * On x86, there is another special case for FSC hardware monitoring chips, 235491ed5349SWolfram Sang * which want regular byte reads (address 0x73.) Fortunately, these are the 235591ed5349SWolfram Sang * only known chips using this I2C address on PC hardware. 235691ed5349SWolfram Sang * Returns 1 if probe succeeded, 0 if not. 235791ed5349SWolfram Sang */ 235891ed5349SWolfram Sang static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) 235991ed5349SWolfram Sang { 236091ed5349SWolfram Sang int err; 236191ed5349SWolfram Sang union i2c_smbus_data dummy; 236291ed5349SWolfram Sang 236391ed5349SWolfram Sang #ifdef CONFIG_X86 236491ed5349SWolfram Sang if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) 236591ed5349SWolfram Sang && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) 236691ed5349SWolfram Sang err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, 236791ed5349SWolfram Sang I2C_SMBUS_BYTE_DATA, &dummy); 236891ed5349SWolfram Sang else 236991ed5349SWolfram Sang #endif 237091ed5349SWolfram Sang if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) 237191ed5349SWolfram Sang && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) 237291ed5349SWolfram Sang err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, 237391ed5349SWolfram Sang I2C_SMBUS_QUICK, NULL); 237491ed5349SWolfram Sang else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) 237591ed5349SWolfram Sang err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, 237691ed5349SWolfram Sang I2C_SMBUS_BYTE, &dummy); 237791ed5349SWolfram Sang else { 237891ed5349SWolfram Sang dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", 237991ed5349SWolfram Sang addr); 238091ed5349SWolfram Sang err = -EOPNOTSUPP; 238191ed5349SWolfram Sang } 238291ed5349SWolfram Sang 238391ed5349SWolfram Sang return err >= 0; 238491ed5349SWolfram Sang } 238591ed5349SWolfram Sang 238691ed5349SWolfram Sang static int i2c_detect_address(struct i2c_client *temp_client, 238791ed5349SWolfram Sang struct i2c_driver *driver) 238891ed5349SWolfram Sang { 238991ed5349SWolfram Sang struct i2c_board_info info; 239091ed5349SWolfram Sang struct i2c_adapter *adapter = temp_client->adapter; 239191ed5349SWolfram Sang int addr = temp_client->addr; 239291ed5349SWolfram Sang int err; 239391ed5349SWolfram Sang 239491ed5349SWolfram Sang /* Make sure the address is valid */ 239591ed5349SWolfram Sang err = i2c_check_7bit_addr_validity_strict(addr); 239691ed5349SWolfram Sang if (err) { 239791ed5349SWolfram Sang dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", 239891ed5349SWolfram Sang addr); 239991ed5349SWolfram Sang return err; 240091ed5349SWolfram Sang } 240191ed5349SWolfram Sang 240291ed5349SWolfram Sang /* Skip if already in use (7 bit, no need to encode flags) */ 240391ed5349SWolfram Sang if (i2c_check_addr_busy(adapter, addr)) 240491ed5349SWolfram Sang return 0; 240591ed5349SWolfram Sang 240691ed5349SWolfram Sang /* Make sure there is something at this address */ 240791ed5349SWolfram Sang if (!i2c_default_probe(adapter, addr)) 240891ed5349SWolfram Sang return 0; 240991ed5349SWolfram Sang 241091ed5349SWolfram Sang /* Finally call the custom detection function */ 241191ed5349SWolfram Sang memset(&info, 0, sizeof(struct i2c_board_info)); 241291ed5349SWolfram Sang info.addr = addr; 241391ed5349SWolfram Sang err = driver->detect(temp_client, &info); 241491ed5349SWolfram Sang if (err) { 241591ed5349SWolfram Sang /* -ENODEV is returned if the detection fails. We catch it 241691ed5349SWolfram Sang here as this isn't an error. */ 241791ed5349SWolfram Sang return err == -ENODEV ? 0 : err; 241891ed5349SWolfram Sang } 241991ed5349SWolfram Sang 242091ed5349SWolfram Sang /* Consistency check */ 242191ed5349SWolfram Sang if (info.type[0] == '\0') { 242291ed5349SWolfram Sang dev_err(&adapter->dev, 242391ed5349SWolfram Sang "%s detection function provided no name for 0x%x\n", 242491ed5349SWolfram Sang driver->driver.name, addr); 242591ed5349SWolfram Sang } else { 242691ed5349SWolfram Sang struct i2c_client *client; 242791ed5349SWolfram Sang 242891ed5349SWolfram Sang /* Detection succeeded, instantiate the device */ 242991ed5349SWolfram Sang if (adapter->class & I2C_CLASS_DEPRECATED) 243091ed5349SWolfram Sang dev_warn(&adapter->dev, 243191ed5349SWolfram Sang "This adapter will soon drop class based instantiation of devices. " 243291ed5349SWolfram Sang "Please make sure client 0x%02x gets instantiated by other means. " 2433ccf988b6SMauro Carvalho Chehab "Check 'Documentation/i2c/instantiating-devices.rst' for details.\n", 243491ed5349SWolfram Sang info.addr); 243591ed5349SWolfram Sang 243691ed5349SWolfram Sang dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", 243791ed5349SWolfram Sang info.type, info.addr); 243887e07437SWolfram Sang client = i2c_new_client_device(adapter, &info); 243987e07437SWolfram Sang if (!IS_ERR(client)) 244091ed5349SWolfram Sang list_add_tail(&client->detected, &driver->clients); 244191ed5349SWolfram Sang else 244291ed5349SWolfram Sang dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", 244391ed5349SWolfram Sang info.type, info.addr); 244491ed5349SWolfram Sang } 244591ed5349SWolfram Sang return 0; 244691ed5349SWolfram Sang } 244791ed5349SWolfram Sang 244891ed5349SWolfram Sang static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) 244991ed5349SWolfram Sang { 245091ed5349SWolfram Sang const unsigned short *address_list; 245191ed5349SWolfram Sang struct i2c_client *temp_client; 245291ed5349SWolfram Sang int i, err = 0; 245391ed5349SWolfram Sang 245491ed5349SWolfram Sang address_list = driver->address_list; 245591ed5349SWolfram Sang if (!driver->detect || !address_list) 245691ed5349SWolfram Sang return 0; 245791ed5349SWolfram Sang 245891ed5349SWolfram Sang /* Warn that the adapter lost class based instantiation */ 245991ed5349SWolfram Sang if (adapter->class == I2C_CLASS_DEPRECATED) { 246091ed5349SWolfram Sang dev_dbg(&adapter->dev, 246191ed5349SWolfram Sang "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. " 2462ccf988b6SMauro Carvalho Chehab "If you need it, check 'Documentation/i2c/instantiating-devices.rst' for alternatives.\n", 246391ed5349SWolfram Sang driver->driver.name); 246491ed5349SWolfram Sang return 0; 246591ed5349SWolfram Sang } 246691ed5349SWolfram Sang 246791ed5349SWolfram Sang /* Stop here if the classes do not match */ 246891ed5349SWolfram Sang if (!(adapter->class & driver->class)) 246991ed5349SWolfram Sang return 0; 247091ed5349SWolfram Sang 247191ed5349SWolfram Sang /* Set up a temporary client to help detect callback */ 247291ed5349SWolfram Sang temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); 247391ed5349SWolfram Sang if (!temp_client) 247491ed5349SWolfram Sang return -ENOMEM; 247591ed5349SWolfram Sang temp_client->adapter = adapter; 247691ed5349SWolfram Sang 247791ed5349SWolfram Sang for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { 247891ed5349SWolfram Sang dev_dbg(&adapter->dev, 247991ed5349SWolfram Sang "found normal entry for adapter %d, addr 0x%02x\n", 2480dd4f2ca9SWolfram Sang i2c_adapter_id(adapter), address_list[i]); 248191ed5349SWolfram Sang temp_client->addr = address_list[i]; 248291ed5349SWolfram Sang err = i2c_detect_address(temp_client, driver); 248391ed5349SWolfram Sang if (unlikely(err)) 248491ed5349SWolfram Sang break; 248591ed5349SWolfram Sang } 248691ed5349SWolfram Sang 248791ed5349SWolfram Sang kfree(temp_client); 248891ed5349SWolfram Sang return err; 248991ed5349SWolfram Sang } 249091ed5349SWolfram Sang 249191ed5349SWolfram Sang int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) 249291ed5349SWolfram Sang { 249391ed5349SWolfram Sang return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, 249491ed5349SWolfram Sang I2C_SMBUS_QUICK, NULL) >= 0; 249591ed5349SWolfram Sang } 249691ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); 249791ed5349SWolfram Sang 249891ed5349SWolfram Sang struct i2c_client * 2499c1d08475SWolfram Sang i2c_new_scanned_device(struct i2c_adapter *adap, 250091ed5349SWolfram Sang struct i2c_board_info *info, 250191ed5349SWolfram Sang unsigned short const *addr_list, 2502edd7a563SWolfram Sang int (*probe)(struct i2c_adapter *adap, unsigned short addr)) 250391ed5349SWolfram Sang { 250491ed5349SWolfram Sang int i; 250591ed5349SWolfram Sang 250691ed5349SWolfram Sang if (!probe) 250791ed5349SWolfram Sang probe = i2c_default_probe; 250891ed5349SWolfram Sang 250991ed5349SWolfram Sang for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { 251091ed5349SWolfram Sang /* Check address validity */ 251191ed5349SWolfram Sang if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) { 251291ed5349SWolfram Sang dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n", 251391ed5349SWolfram Sang addr_list[i]); 251491ed5349SWolfram Sang continue; 251591ed5349SWolfram Sang } 251691ed5349SWolfram Sang 251791ed5349SWolfram Sang /* Check address availability (7 bit, no need to encode flags) */ 251891ed5349SWolfram Sang if (i2c_check_addr_busy(adap, addr_list[i])) { 251991ed5349SWolfram Sang dev_dbg(&adap->dev, 252091ed5349SWolfram Sang "Address 0x%02x already in use, not probing\n", 252191ed5349SWolfram Sang addr_list[i]); 252291ed5349SWolfram Sang continue; 252391ed5349SWolfram Sang } 252491ed5349SWolfram Sang 252591ed5349SWolfram Sang /* Test address responsiveness */ 252691ed5349SWolfram Sang if (probe(adap, addr_list[i])) 252791ed5349SWolfram Sang break; 252891ed5349SWolfram Sang } 252991ed5349SWolfram Sang 253091ed5349SWolfram Sang if (addr_list[i] == I2C_CLIENT_END) { 253191ed5349SWolfram Sang dev_dbg(&adap->dev, "Probing failed, no device found\n"); 2532c1d08475SWolfram Sang return ERR_PTR(-ENODEV); 253391ed5349SWolfram Sang } 253491ed5349SWolfram Sang 253591ed5349SWolfram Sang info->addr = addr_list[i]; 2536c1d08475SWolfram Sang return i2c_new_client_device(adap, info); 2537c1d08475SWolfram Sang } 2538c1d08475SWolfram Sang EXPORT_SYMBOL_GPL(i2c_new_scanned_device); 2539c1d08475SWolfram Sang 254091ed5349SWolfram Sang struct i2c_adapter *i2c_get_adapter(int nr) 254191ed5349SWolfram Sang { 254291ed5349SWolfram Sang struct i2c_adapter *adapter; 254391ed5349SWolfram Sang 254491ed5349SWolfram Sang mutex_lock(&core_lock); 254591ed5349SWolfram Sang adapter = idr_find(&i2c_adapter_idr, nr); 254691ed5349SWolfram Sang if (!adapter) 254791ed5349SWolfram Sang goto exit; 254891ed5349SWolfram Sang 254991ed5349SWolfram Sang if (try_module_get(adapter->owner)) 255091ed5349SWolfram Sang get_device(&adapter->dev); 255191ed5349SWolfram Sang else 255291ed5349SWolfram Sang adapter = NULL; 255391ed5349SWolfram Sang 255491ed5349SWolfram Sang exit: 255591ed5349SWolfram Sang mutex_unlock(&core_lock); 255691ed5349SWolfram Sang return adapter; 255791ed5349SWolfram Sang } 255891ed5349SWolfram Sang EXPORT_SYMBOL(i2c_get_adapter); 255991ed5349SWolfram Sang 256091ed5349SWolfram Sang void i2c_put_adapter(struct i2c_adapter *adap) 256191ed5349SWolfram Sang { 256291ed5349SWolfram Sang if (!adap) 256391ed5349SWolfram Sang return; 256491ed5349SWolfram Sang 256591ed5349SWolfram Sang put_device(&adap->dev); 256691ed5349SWolfram Sang module_put(adap->owner); 256791ed5349SWolfram Sang } 256891ed5349SWolfram Sang EXPORT_SYMBOL(i2c_put_adapter); 256991ed5349SWolfram Sang 2570e94bc5d1SWolfram Sang /** 2571e94bc5d1SWolfram Sang * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg 2572e94bc5d1SWolfram Sang * @msg: the message to be checked 2573bf263c35SWolfram Sang * @threshold: the minimum number of bytes for which using DMA makes sense. 2574bf263c35SWolfram Sang * Should at least be 1. 2575e94bc5d1SWolfram Sang * 2576e94bc5d1SWolfram Sang * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO. 2577e94bc5d1SWolfram Sang * Or a valid pointer to be used with DMA. After use, release it by 257834d1b82cSStephen Boyd * calling i2c_put_dma_safe_msg_buf(). 2579e94bc5d1SWolfram Sang * 2580e94bc5d1SWolfram Sang * This function must only be called from process context! 2581e94bc5d1SWolfram Sang */ 2582e94bc5d1SWolfram Sang u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold) 2583e94bc5d1SWolfram Sang { 2584bf263c35SWolfram Sang /* also skip 0-length msgs for bogus thresholds of 0 */ 2585bf263c35SWolfram Sang if (!threshold) 2586bf263c35SWolfram Sang pr_debug("DMA buffer for addr=0x%02x with length 0 is bogus\n", 2587bf263c35SWolfram Sang msg->addr); 2588bf263c35SWolfram Sang if (msg->len < threshold || msg->len == 0) 2589e94bc5d1SWolfram Sang return NULL; 2590e94bc5d1SWolfram Sang 2591e94bc5d1SWolfram Sang if (msg->flags & I2C_M_DMA_SAFE) 2592e94bc5d1SWolfram Sang return msg->buf; 2593e94bc5d1SWolfram Sang 2594e94bc5d1SWolfram Sang pr_debug("using bounce buffer for addr=0x%02x, len=%d\n", 2595e94bc5d1SWolfram Sang msg->addr, msg->len); 2596e94bc5d1SWolfram Sang 2597e94bc5d1SWolfram Sang if (msg->flags & I2C_M_RD) 2598e94bc5d1SWolfram Sang return kzalloc(msg->len, GFP_KERNEL); 2599e94bc5d1SWolfram Sang else 2600e94bc5d1SWolfram Sang return kmemdup(msg->buf, msg->len, GFP_KERNEL); 2601e94bc5d1SWolfram Sang } 2602e94bc5d1SWolfram Sang EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf); 2603e94bc5d1SWolfram Sang 2604e94bc5d1SWolfram Sang /** 260582fe39a6SWolfram Sang * i2c_put_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg 2606e94bc5d1SWolfram Sang * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL. 260782fe39a6SWolfram Sang * @msg: the message which the buffer corresponds to 260882fe39a6SWolfram Sang * @xferred: bool saying if the message was transferred 2609e94bc5d1SWolfram Sang */ 261082fe39a6SWolfram Sang void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred) 2611e94bc5d1SWolfram Sang { 2612e94bc5d1SWolfram Sang if (!buf || buf == msg->buf) 2613e94bc5d1SWolfram Sang return; 2614e94bc5d1SWolfram Sang 261582fe39a6SWolfram Sang if (xferred && msg->flags & I2C_M_RD) 2616e94bc5d1SWolfram Sang memcpy(msg->buf, buf, msg->len); 2617e94bc5d1SWolfram Sang 2618e94bc5d1SWolfram Sang kfree(buf); 2619e94bc5d1SWolfram Sang } 262082fe39a6SWolfram Sang EXPORT_SYMBOL_GPL(i2c_put_dma_safe_msg_buf); 2621e94bc5d1SWolfram Sang 262291ed5349SWolfram Sang MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); 262391ed5349SWolfram Sang MODULE_DESCRIPTION("I2C-Bus main module"); 262491ed5349SWolfram Sang MODULE_LICENSE("GPL"); 2625