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> 2791ed5349SWolfram Sang #include <linux/irqflags.h> 2891ed5349SWolfram Sang #include <linux/jump_label.h> 2991ed5349SWolfram Sang #include <linux/kernel.h> 3091ed5349SWolfram Sang #include <linux/module.h> 3191ed5349SWolfram Sang #include <linux/mutex.h> 3291ed5349SWolfram Sang #include <linux/of_device.h> 3391ed5349SWolfram Sang #include <linux/of.h> 3491ed5349SWolfram Sang #include <linux/of_irq.h> 3591ed5349SWolfram Sang #include <linux/pm_domain.h> 3691ed5349SWolfram Sang #include <linux/pm_runtime.h> 3791ed5349SWolfram Sang #include <linux/pm_wakeirq.h> 3891ed5349SWolfram Sang #include <linux/property.h> 3991ed5349SWolfram Sang #include <linux/rwsem.h> 4091ed5349SWolfram Sang #include <linux/slab.h> 4191ed5349SWolfram Sang 4291ed5349SWolfram Sang #include "i2c-core.h" 4391ed5349SWolfram Sang 4491ed5349SWolfram Sang #define CREATE_TRACE_POINTS 4591ed5349SWolfram Sang #include <trace/events/i2c.h> 4691ed5349SWolfram Sang 4791ed5349SWolfram Sang #define I2C_ADDR_OFFSET_TEN_BIT 0xa000 4891ed5349SWolfram Sang #define I2C_ADDR_OFFSET_SLAVE 0x1000 4991ed5349SWolfram Sang 5091ed5349SWolfram Sang #define I2C_ADDR_7BITS_MAX 0x77 5191ed5349SWolfram Sang #define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1) 5291ed5349SWolfram Sang 53dde67eb1SPeter Rosin #define I2C_ADDR_DEVICE_ID 0x7c 54dde67eb1SPeter Rosin 5561e3d0f7SWolfram Sang /* 5661e3d0f7SWolfram Sang * core_lock protects i2c_adapter_idr, and guarantees that device detection, 570c36dd37SWolfram Sang * deletion of detected devices are serialized 5861e3d0f7SWolfram Sang */ 5991ed5349SWolfram Sang static DEFINE_MUTEX(core_lock); 6091ed5349SWolfram Sang static DEFINE_IDR(i2c_adapter_idr); 6191ed5349SWolfram Sang 6291ed5349SWolfram Sang static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); 6391ed5349SWolfram Sang 6450888b01SDavidlohr Bueso static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key); 6591ed5349SWolfram Sang static bool is_registered; 6691ed5349SWolfram Sang 6791ed5349SWolfram Sang int i2c_transfer_trace_reg(void) 6891ed5349SWolfram Sang { 6950888b01SDavidlohr Bueso static_branch_inc(&i2c_trace_msg_key); 7091ed5349SWolfram Sang return 0; 7191ed5349SWolfram Sang } 7291ed5349SWolfram Sang 7391ed5349SWolfram Sang void i2c_transfer_trace_unreg(void) 7491ed5349SWolfram Sang { 7550888b01SDavidlohr Bueso static_branch_dec(&i2c_trace_msg_key); 7691ed5349SWolfram Sang } 7791ed5349SWolfram Sang 7891ed5349SWolfram Sang const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 7991ed5349SWolfram Sang const struct i2c_client *client) 8091ed5349SWolfram Sang { 8191ed5349SWolfram Sang if (!(id && client)) 8291ed5349SWolfram Sang return NULL; 8391ed5349SWolfram Sang 8491ed5349SWolfram Sang while (id->name[0]) { 8591ed5349SWolfram Sang if (strcmp(client->name, id->name) == 0) 8691ed5349SWolfram Sang return id; 8791ed5349SWolfram Sang id++; 8891ed5349SWolfram Sang } 8991ed5349SWolfram Sang return NULL; 9091ed5349SWolfram Sang } 9191ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_match_id); 9291ed5349SWolfram Sang 9391ed5349SWolfram Sang static int i2c_device_match(struct device *dev, struct device_driver *drv) 9491ed5349SWolfram Sang { 9591ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 9691ed5349SWolfram Sang struct i2c_driver *driver; 9791ed5349SWolfram Sang 9891ed5349SWolfram Sang 9991ed5349SWolfram Sang /* Attempt an OF style match */ 10091ed5349SWolfram Sang if (i2c_of_match_device(drv->of_match_table, client)) 10191ed5349SWolfram Sang return 1; 10291ed5349SWolfram Sang 10391ed5349SWolfram Sang /* Then ACPI style match */ 10491ed5349SWolfram Sang if (acpi_driver_match_device(dev, drv)) 10591ed5349SWolfram Sang return 1; 10691ed5349SWolfram Sang 10791ed5349SWolfram Sang driver = to_i2c_driver(drv); 10891ed5349SWolfram Sang 10991ed5349SWolfram Sang /* Finally an I2C match */ 11091ed5349SWolfram Sang if (i2c_match_id(driver->id_table, client)) 11191ed5349SWolfram Sang return 1; 11291ed5349SWolfram Sang 11391ed5349SWolfram Sang return 0; 11491ed5349SWolfram Sang } 11591ed5349SWolfram Sang 11691ed5349SWolfram Sang static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) 11791ed5349SWolfram Sang { 11891ed5349SWolfram Sang struct i2c_client *client = to_i2c_client(dev); 11991ed5349SWolfram Sang int rc; 12091ed5349SWolfram Sang 121af503716SJavier Martinez Canillas rc = of_device_uevent_modalias(dev, env); 122af503716SJavier Martinez Canillas if (rc != -ENODEV) 123af503716SJavier Martinez Canillas return rc; 124af503716SJavier Martinez Canillas 12591ed5349SWolfram Sang rc = acpi_device_uevent_modalias(dev, env); 12691ed5349SWolfram Sang if (rc != -ENODEV) 12791ed5349SWolfram Sang return rc; 12891ed5349SWolfram Sang 12991ed5349SWolfram Sang return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name); 13091ed5349SWolfram Sang } 13191ed5349SWolfram Sang 13291ed5349SWolfram Sang /* i2c bus recovery routines */ 13391ed5349SWolfram Sang static int get_scl_gpio_value(struct i2c_adapter *adap) 13491ed5349SWolfram Sang { 1353991c5c8SPhil Reid return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod); 13691ed5349SWolfram Sang } 13791ed5349SWolfram Sang 13891ed5349SWolfram Sang static void set_scl_gpio_value(struct i2c_adapter *adap, int val) 13991ed5349SWolfram Sang { 1403991c5c8SPhil Reid gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val); 14191ed5349SWolfram Sang } 14291ed5349SWolfram Sang 14391ed5349SWolfram Sang static int get_sda_gpio_value(struct i2c_adapter *adap) 14491ed5349SWolfram Sang { 1453991c5c8SPhil Reid return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod); 14691ed5349SWolfram Sang } 14791ed5349SWolfram Sang 1488092178fSWolfram Sang static void set_sda_gpio_value(struct i2c_adapter *adap, int val) 14991ed5349SWolfram Sang { 1508092178fSWolfram Sang gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val); 15191ed5349SWolfram Sang } 15291ed5349SWolfram Sang 1537ca5f6beSWolfram Sang static int i2c_generic_bus_free(struct i2c_adapter *adap) 1547ca5f6beSWolfram Sang { 1557ca5f6beSWolfram Sang struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; 1567ca5f6beSWolfram Sang int ret = -EOPNOTSUPP; 1577ca5f6beSWolfram Sang 1587ca5f6beSWolfram Sang if (bri->get_bus_free) 1597ca5f6beSWolfram Sang ret = bri->get_bus_free(adap); 1607ca5f6beSWolfram Sang else if (bri->get_sda) 1617ca5f6beSWolfram Sang ret = bri->get_sda(adap); 1627ca5f6beSWolfram Sang 1637ca5f6beSWolfram Sang if (ret < 0) 1647ca5f6beSWolfram Sang return ret; 1657ca5f6beSWolfram Sang 1667ca5f6beSWolfram Sang return ret ? 0 : -EBUSY; 1677ca5f6beSWolfram Sang } 1687ca5f6beSWolfram Sang 16991ed5349SWolfram Sang /* 17091ed5349SWolfram Sang * We are generating clock pulses. ndelay() determines durating of clk pulses. 17191ed5349SWolfram Sang * We will generate clock with rate 100 KHz and so duration of both clock levels 17291ed5349SWolfram Sang * is: delay in ns = (10^6 / 100) / 2 17391ed5349SWolfram Sang */ 17491ed5349SWolfram Sang #define RECOVERY_NDELAY 5000 17591ed5349SWolfram Sang #define RECOVERY_CLK_CNT 9 17691ed5349SWolfram Sang 177e1eb7d28SPhil Reid int i2c_generic_scl_recovery(struct i2c_adapter *adap) 17891ed5349SWolfram Sang { 17991ed5349SWolfram Sang struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; 180cf676908SLinus Torvalds int i = 0, scl = 1, ret = 0; 18191ed5349SWolfram Sang 18291ed5349SWolfram Sang if (bri->prepare_recovery) 18391ed5349SWolfram Sang bri->prepare_recovery(adap); 18491ed5349SWolfram Sang 185c4ae05b9SWolfram Sang /* 186c4ae05b9SWolfram Sang * If we can set SDA, we will always create a STOP to ensure additional 187c4ae05b9SWolfram Sang * pulses will do no harm. This is achieved by letting SDA follow SCL 188c4ae05b9SWolfram Sang * half a cycle later. Check the 'incomplete_write_byte' fault injector 189cf8ce8b8SRussell King * for details. Note that we must honour tsu:sto, 4us, but lets use 5us 190cf8ce8b8SRussell King * here for simplicity. 191c4ae05b9SWolfram Sang */ 192f7ff75e2SWolfram Sang bri->set_scl(adap, scl); 193cf8ce8b8SRussell King ndelay(RECOVERY_NDELAY); 19472b08fccSWolfram Sang if (bri->set_sda) 195c4ae05b9SWolfram Sang bri->set_sda(adap, scl); 196c4ae05b9SWolfram Sang ndelay(RECOVERY_NDELAY / 2); 19791ed5349SWolfram Sang 19891ed5349SWolfram Sang /* 19991ed5349SWolfram Sang * By this time SCL is high, as we need to give 9 falling-rising edges 20091ed5349SWolfram Sang */ 20191ed5349SWolfram Sang while (i++ < RECOVERY_CLK_CNT * 2) { 202f7ff75e2SWolfram Sang if (scl) { 20391ed5349SWolfram Sang /* SCL shouldn't be low here */ 20491ed5349SWolfram Sang if (!bri->get_scl(adap)) { 20591ed5349SWolfram Sang dev_err(&adap->dev, 20691ed5349SWolfram Sang "SCL is stuck low, exit recovery\n"); 20791ed5349SWolfram Sang ret = -EBUSY; 20891ed5349SWolfram Sang break; 20991ed5349SWolfram Sang } 21091ed5349SWolfram Sang } 21191ed5349SWolfram Sang 212f7ff75e2SWolfram Sang scl = !scl; 213f7ff75e2SWolfram Sang bri->set_scl(adap, scl); 214c4ae05b9SWolfram Sang /* Creating STOP again, see above */ 215cf8ce8b8SRussell King if (scl) { 216cf8ce8b8SRussell King /* Honour minimum tsu:sto */ 217cf8ce8b8SRussell King ndelay(RECOVERY_NDELAY); 218cf8ce8b8SRussell King } else { 219cf8ce8b8SRussell King /* Honour minimum tf and thd:dat */ 220abe41184SWolfram Sang ndelay(RECOVERY_NDELAY / 2); 221cf8ce8b8SRussell King } 222abe41184SWolfram Sang if (bri->set_sda) 223f7ff75e2SWolfram Sang bri->set_sda(adap, scl); 224abe41184SWolfram Sang ndelay(RECOVERY_NDELAY / 2); 2250b71026cSWolfram Sang 226f7ff75e2SWolfram Sang if (scl) { 2277ca5f6beSWolfram Sang ret = i2c_generic_bus_free(adap); 2280b71026cSWolfram Sang if (ret == 0) 2290b71026cSWolfram Sang break; 23091ed5349SWolfram Sang } 23191ed5349SWolfram Sang } 23291ed5349SWolfram Sang 2337ca5f6beSWolfram Sang /* If we can't check bus status, assume recovery worked */ 2347ca5f6beSWolfram Sang if (ret == -EOPNOTSUPP) 2357ca5f6beSWolfram Sang ret = 0; 2362806e6adSWolfram Sang 23791ed5349SWolfram Sang if (bri->unprepare_recovery) 23891ed5349SWolfram Sang bri->unprepare_recovery(adap); 23991ed5349SWolfram Sang 24091ed5349SWolfram Sang return ret; 24191ed5349SWolfram Sang } 24291ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery); 24391ed5349SWolfram Sang 24491ed5349SWolfram Sang int i2c_recover_bus(struct i2c_adapter *adap) 24591ed5349SWolfram Sang { 24691ed5349SWolfram Sang if (!adap->bus_recovery_info) 24791ed5349SWolfram Sang return -EOPNOTSUPP; 24891ed5349SWolfram Sang 24991ed5349SWolfram Sang dev_dbg(&adap->dev, "Trying i2c bus recovery\n"); 25091ed5349SWolfram Sang return adap->bus_recovery_info->recover_bus(adap); 25191ed5349SWolfram Sang } 25291ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_recover_bus); 25391ed5349SWolfram Sang 25491ed5349SWolfram Sang static void i2c_init_recovery(struct i2c_adapter *adap) 25591ed5349SWolfram Sang { 25691ed5349SWolfram Sang struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; 25791ed5349SWolfram Sang char *err_str; 25891ed5349SWolfram Sang 25991ed5349SWolfram Sang if (!bri) 26091ed5349SWolfram Sang return; 26191ed5349SWolfram Sang 26291ed5349SWolfram Sang if (!bri->recover_bus) { 26391ed5349SWolfram Sang err_str = "no recover_bus() found"; 26491ed5349SWolfram Sang goto err; 26591ed5349SWolfram Sang } 26691ed5349SWolfram Sang 2673991c5c8SPhil Reid if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) { 26891ed5349SWolfram Sang bri->get_scl = get_scl_gpio_value; 26991ed5349SWolfram Sang bri->set_scl = set_scl_gpio_value; 2708092178fSWolfram Sang if (bri->sda_gpiod) { 2713991c5c8SPhil Reid bri->get_sda = get_sda_gpio_value; 2728092178fSWolfram Sang /* FIXME: add proper flag instead of '0' once available */ 2738092178fSWolfram Sang if (gpiod_get_direction(bri->sda_gpiod) == 0) 2748092178fSWolfram Sang bri->set_sda = set_sda_gpio_value; 2758092178fSWolfram Sang } 2763991c5c8SPhil Reid return; 2773991c5c8SPhil Reid } 2783991c5c8SPhil Reid 279e1eb7d28SPhil Reid if (bri->recover_bus == i2c_generic_scl_recovery) { 28091ed5349SWolfram Sang /* Generic SCL recovery */ 28191ed5349SWolfram Sang if (!bri->set_scl || !bri->get_scl) { 28291ed5349SWolfram Sang err_str = "no {get|set}_scl() found"; 28391ed5349SWolfram Sang goto err; 28491ed5349SWolfram Sang } 285ffc59c49SWolfram Sang if (!bri->set_sda && !bri->get_sda) { 286ffc59c49SWolfram Sang err_str = "either get_sda() or set_sda() needed"; 287ffc59c49SWolfram Sang goto err; 288ffc59c49SWolfram Sang } 28991ed5349SWolfram Sang } 29091ed5349SWolfram Sang 29191ed5349SWolfram Sang return; 29291ed5349SWolfram Sang err: 29391ed5349SWolfram Sang dev_err(&adap->dev, "Not using recovery: %s\n", err_str); 29491ed5349SWolfram Sang adap->bus_recovery_info = NULL; 29591ed5349SWolfram Sang } 29691ed5349SWolfram Sang 29791ed5349SWolfram Sang static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client) 29891ed5349SWolfram Sang { 29991ed5349SWolfram Sang struct i2c_adapter *adap = client->adapter; 30091ed5349SWolfram Sang unsigned int irq; 30191ed5349SWolfram Sang 30291ed5349SWolfram Sang if (!adap->host_notify_domain) 30391ed5349SWolfram Sang return -ENXIO; 30491ed5349SWolfram Sang 30591ed5349SWolfram Sang if (client->flags & I2C_CLIENT_TEN) 30691ed5349SWolfram Sang return -EINVAL; 30791ed5349SWolfram Sang 308b9bb3fdfSCharles Keepax irq = irq_create_mapping(adap->host_notify_domain, client->addr); 30991ed5349SWolfram Sang 31091ed5349SWolfram Sang return irq > 0 ? irq : -ENXIO; 31191ed5349SWolfram Sang } 31291ed5349SWolfram Sang 31391ed5349SWolfram Sang static int i2c_device_probe(struct device *dev) 31491ed5349SWolfram Sang { 31591ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 31691ed5349SWolfram Sang struct i2c_driver *driver; 31791ed5349SWolfram Sang int status; 31891ed5349SWolfram Sang 31991ed5349SWolfram Sang if (!client) 32091ed5349SWolfram Sang return 0; 32191ed5349SWolfram Sang 3226e76cb7dSCharles Keepax client->irq = client->init_irq; 3236e76cb7dSCharles Keepax 3240c2a3493SWolfram Sang if (!client->irq) { 32591ed5349SWolfram Sang int irq = -ENOENT; 32691ed5349SWolfram Sang 32791ed5349SWolfram Sang if (client->flags & I2C_CLIENT_HOST_NOTIFY) { 32891ed5349SWolfram Sang dev_dbg(dev, "Using Host Notify IRQ\n"); 32972bfcee1SJarkko Nikula /* Keep adapter active when Host Notify is required */ 33072bfcee1SJarkko Nikula pm_runtime_get_sync(&client->adapter->dev); 33191ed5349SWolfram Sang irq = i2c_smbus_host_notify_to_irq(client); 33291ed5349SWolfram Sang } else if (dev->of_node) { 33391ed5349SWolfram Sang irq = of_irq_get_byname(dev->of_node, "irq"); 33491ed5349SWolfram Sang if (irq == -EINVAL || irq == -ENODATA) 33591ed5349SWolfram Sang irq = of_irq_get(dev->of_node, 0); 33691ed5349SWolfram Sang } else if (ACPI_COMPANION(dev)) { 33716c9db1dSCharles Keepax irq = i2c_acpi_get_irq(client); 33891ed5349SWolfram Sang } 3393c3dd56fSAlain Volmat if (irq == -EPROBE_DEFER) { 3403c3dd56fSAlain Volmat status = irq; 3413c3dd56fSAlain Volmat goto put_sync_adapter; 3423c3dd56fSAlain Volmat } 34391ed5349SWolfram Sang 34491ed5349SWolfram Sang if (irq < 0) 34591ed5349SWolfram Sang irq = 0; 34691ed5349SWolfram Sang 34791ed5349SWolfram Sang client->irq = irq; 34891ed5349SWolfram Sang } 34991ed5349SWolfram Sang 3500c2a3493SWolfram Sang driver = to_i2c_driver(dev->driver); 3510c2a3493SWolfram Sang 35291ed5349SWolfram Sang /* 353f4b17a14SJavier Martinez Canillas * An I2C ID table is not mandatory, if and only if, a suitable OF 354f4b17a14SJavier Martinez Canillas * or ACPI ID table is supplied for the probing device. 35591ed5349SWolfram Sang */ 35691ed5349SWolfram Sang if (!driver->id_table && 357c64ffff7SAndy Shevchenko !i2c_acpi_match_device(dev->driver->acpi_match_table, client) && 3583c3dd56fSAlain Volmat !i2c_of_match_device(dev->driver->of_match_table, client)) { 3593c3dd56fSAlain Volmat status = -ENODEV; 3603c3dd56fSAlain Volmat goto put_sync_adapter; 3613c3dd56fSAlain Volmat } 36291ed5349SWolfram Sang 36391ed5349SWolfram Sang if (client->flags & I2C_CLIENT_WAKE) { 3643e99834cSAndy Shevchenko int wakeirq; 36591ed5349SWolfram Sang 36691ed5349SWolfram Sang wakeirq = of_irq_get_byname(dev->of_node, "wakeup"); 3673c3dd56fSAlain Volmat if (wakeirq == -EPROBE_DEFER) { 3683c3dd56fSAlain Volmat status = wakeirq; 3693c3dd56fSAlain Volmat goto put_sync_adapter; 3703c3dd56fSAlain Volmat } 37191ed5349SWolfram Sang 37291ed5349SWolfram Sang device_init_wakeup(&client->dev, true); 37391ed5349SWolfram Sang 37491ed5349SWolfram Sang if (wakeirq > 0 && wakeirq != client->irq) 37591ed5349SWolfram Sang status = dev_pm_set_dedicated_wake_irq(dev, wakeirq); 37691ed5349SWolfram Sang else if (client->irq > 0) 37791ed5349SWolfram Sang status = dev_pm_set_wake_irq(dev, client->irq); 37891ed5349SWolfram Sang else 37991ed5349SWolfram Sang status = 0; 38091ed5349SWolfram Sang 38191ed5349SWolfram Sang if (status) 38291ed5349SWolfram Sang dev_warn(&client->dev, "failed to set up wakeup irq\n"); 38391ed5349SWolfram Sang } 38491ed5349SWolfram Sang 38591ed5349SWolfram Sang dev_dbg(dev, "probe\n"); 38691ed5349SWolfram Sang 38791ed5349SWolfram Sang status = of_clk_set_defaults(dev->of_node, false); 38891ed5349SWolfram Sang if (status < 0) 38991ed5349SWolfram Sang goto err_clear_wakeup_irq; 39091ed5349SWolfram Sang 39191ed5349SWolfram Sang status = dev_pm_domain_attach(&client->dev, true); 392e6a20b6cSUlf Hansson if (status) 39391ed5349SWolfram Sang goto err_clear_wakeup_irq; 39491ed5349SWolfram Sang 39591ed5349SWolfram Sang /* 39691ed5349SWolfram Sang * When there are no more users of probe(), 39791ed5349SWolfram Sang * rename probe_new to probe. 39891ed5349SWolfram Sang */ 39991ed5349SWolfram Sang if (driver->probe_new) 40091ed5349SWolfram Sang status = driver->probe_new(client); 40191ed5349SWolfram Sang else if (driver->probe) 40291ed5349SWolfram Sang status = driver->probe(client, 40391ed5349SWolfram Sang i2c_match_id(driver->id_table, client)); 40491ed5349SWolfram Sang else 40591ed5349SWolfram Sang status = -EINVAL; 40691ed5349SWolfram Sang 40791ed5349SWolfram Sang if (status) 40891ed5349SWolfram Sang goto err_detach_pm_domain; 40991ed5349SWolfram Sang 41091ed5349SWolfram Sang return 0; 41191ed5349SWolfram Sang 41291ed5349SWolfram Sang err_detach_pm_domain: 41391ed5349SWolfram Sang dev_pm_domain_detach(&client->dev, true); 41491ed5349SWolfram Sang err_clear_wakeup_irq: 41591ed5349SWolfram Sang dev_pm_clear_wake_irq(&client->dev); 41691ed5349SWolfram Sang device_init_wakeup(&client->dev, false); 4173c3dd56fSAlain Volmat put_sync_adapter: 4183c3dd56fSAlain Volmat if (client->flags & I2C_CLIENT_HOST_NOTIFY) 4193c3dd56fSAlain Volmat pm_runtime_put_sync(&client->adapter->dev); 4203c3dd56fSAlain Volmat 42191ed5349SWolfram Sang return status; 42291ed5349SWolfram Sang } 42391ed5349SWolfram Sang 42491ed5349SWolfram Sang static int i2c_device_remove(struct device *dev) 42591ed5349SWolfram Sang { 42691ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 42791ed5349SWolfram Sang struct i2c_driver *driver; 42891ed5349SWolfram Sang int status = 0; 42991ed5349SWolfram Sang 43091ed5349SWolfram Sang if (!client || !dev->driver) 43191ed5349SWolfram Sang return 0; 43291ed5349SWolfram Sang 43391ed5349SWolfram Sang driver = to_i2c_driver(dev->driver); 43491ed5349SWolfram Sang if (driver->remove) { 43591ed5349SWolfram Sang dev_dbg(dev, "remove\n"); 43691ed5349SWolfram Sang status = driver->remove(client); 43791ed5349SWolfram Sang } 43891ed5349SWolfram Sang 43991ed5349SWolfram Sang dev_pm_domain_detach(&client->dev, true); 44091ed5349SWolfram Sang 44191ed5349SWolfram Sang dev_pm_clear_wake_irq(&client->dev); 44291ed5349SWolfram Sang device_init_wakeup(&client->dev, false); 44391ed5349SWolfram Sang 4446e76cb7dSCharles Keepax client->irq = 0; 44572bfcee1SJarkko Nikula if (client->flags & I2C_CLIENT_HOST_NOTIFY) 44672bfcee1SJarkko Nikula pm_runtime_put(&client->adapter->dev); 4476f108dd7SCharles Keepax 44891ed5349SWolfram Sang return status; 44991ed5349SWolfram Sang } 45091ed5349SWolfram Sang 45191ed5349SWolfram Sang static void i2c_device_shutdown(struct device *dev) 45291ed5349SWolfram Sang { 45391ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 45491ed5349SWolfram Sang struct i2c_driver *driver; 45591ed5349SWolfram Sang 45691ed5349SWolfram Sang if (!client || !dev->driver) 45791ed5349SWolfram Sang return; 45891ed5349SWolfram Sang driver = to_i2c_driver(dev->driver); 45991ed5349SWolfram Sang if (driver->shutdown) 46091ed5349SWolfram Sang driver->shutdown(client); 46191ed5349SWolfram Sang } 46291ed5349SWolfram Sang 46391ed5349SWolfram Sang static void i2c_client_dev_release(struct device *dev) 46491ed5349SWolfram Sang { 46591ed5349SWolfram Sang kfree(to_i2c_client(dev)); 46691ed5349SWolfram Sang } 46791ed5349SWolfram Sang 46891ed5349SWolfram Sang static ssize_t 46954a19fd4SGeert Uytterhoeven name_show(struct device *dev, struct device_attribute *attr, char *buf) 47091ed5349SWolfram Sang { 47191ed5349SWolfram Sang return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? 47291ed5349SWolfram Sang to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); 47391ed5349SWolfram Sang } 47454a19fd4SGeert Uytterhoeven static DEVICE_ATTR_RO(name); 47591ed5349SWolfram Sang 47691ed5349SWolfram Sang static ssize_t 47754a19fd4SGeert Uytterhoeven modalias_show(struct device *dev, struct device_attribute *attr, char *buf) 47891ed5349SWolfram Sang { 47991ed5349SWolfram Sang struct i2c_client *client = to_i2c_client(dev); 48091ed5349SWolfram Sang int len; 48191ed5349SWolfram Sang 482af503716SJavier Martinez Canillas len = of_device_modalias(dev, buf, PAGE_SIZE); 483af503716SJavier Martinez Canillas if (len != -ENODEV) 484af503716SJavier Martinez Canillas return len; 485af503716SJavier Martinez Canillas 48691ed5349SWolfram Sang len = acpi_device_modalias(dev, buf, PAGE_SIZE -1); 48791ed5349SWolfram Sang if (len != -ENODEV) 48891ed5349SWolfram Sang return len; 48991ed5349SWolfram Sang 49091ed5349SWolfram Sang return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); 49191ed5349SWolfram Sang } 49254a19fd4SGeert Uytterhoeven static DEVICE_ATTR_RO(modalias); 49391ed5349SWolfram Sang 49491ed5349SWolfram Sang static struct attribute *i2c_dev_attrs[] = { 49591ed5349SWolfram Sang &dev_attr_name.attr, 49691ed5349SWolfram Sang /* modalias helps coldplug: modprobe $(cat .../modalias) */ 49791ed5349SWolfram Sang &dev_attr_modalias.attr, 49891ed5349SWolfram Sang NULL 49991ed5349SWolfram Sang }; 50091ed5349SWolfram Sang ATTRIBUTE_GROUPS(i2c_dev); 50191ed5349SWolfram Sang 50291ed5349SWolfram Sang struct bus_type i2c_bus_type = { 50391ed5349SWolfram Sang .name = "i2c", 50491ed5349SWolfram Sang .match = i2c_device_match, 50591ed5349SWolfram Sang .probe = i2c_device_probe, 50691ed5349SWolfram Sang .remove = i2c_device_remove, 50791ed5349SWolfram Sang .shutdown = i2c_device_shutdown, 50891ed5349SWolfram Sang }; 50991ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_bus_type); 51091ed5349SWolfram Sang 51191ed5349SWolfram Sang struct device_type i2c_client_type = { 51291ed5349SWolfram Sang .groups = i2c_dev_groups, 51391ed5349SWolfram Sang .uevent = i2c_device_uevent, 51491ed5349SWolfram Sang .release = i2c_client_dev_release, 51591ed5349SWolfram Sang }; 51691ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_client_type); 51791ed5349SWolfram Sang 51891ed5349SWolfram Sang 51991ed5349SWolfram Sang /** 52091ed5349SWolfram Sang * i2c_verify_client - return parameter as i2c_client, or NULL 52191ed5349SWolfram Sang * @dev: device, probably from some driver model iterator 52291ed5349SWolfram Sang * 52391ed5349SWolfram Sang * When traversing the driver model tree, perhaps using driver model 52491ed5349SWolfram Sang * iterators like @device_for_each_child(), you can't assume very much 52591ed5349SWolfram Sang * about the nodes you find. Use this function to avoid oopses caused 52691ed5349SWolfram Sang * by wrongly treating some non-I2C device as an i2c_client. 52791ed5349SWolfram Sang */ 52891ed5349SWolfram Sang struct i2c_client *i2c_verify_client(struct device *dev) 52991ed5349SWolfram Sang { 53091ed5349SWolfram Sang return (dev->type == &i2c_client_type) 53191ed5349SWolfram Sang ? to_i2c_client(dev) 53291ed5349SWolfram Sang : NULL; 53391ed5349SWolfram Sang } 53491ed5349SWolfram Sang EXPORT_SYMBOL(i2c_verify_client); 53591ed5349SWolfram Sang 53691ed5349SWolfram Sang 53791ed5349SWolfram Sang /* Return a unique address which takes the flags of the client into account */ 53891ed5349SWolfram Sang static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client) 53991ed5349SWolfram Sang { 54091ed5349SWolfram Sang unsigned short addr = client->addr; 54191ed5349SWolfram Sang 54291ed5349SWolfram Sang /* For some client flags, add an arbitrary offset to avoid collisions */ 54391ed5349SWolfram Sang if (client->flags & I2C_CLIENT_TEN) 54491ed5349SWolfram Sang addr |= I2C_ADDR_OFFSET_TEN_BIT; 54591ed5349SWolfram Sang 54691ed5349SWolfram Sang if (client->flags & I2C_CLIENT_SLAVE) 54791ed5349SWolfram Sang addr |= I2C_ADDR_OFFSET_SLAVE; 54891ed5349SWolfram Sang 54991ed5349SWolfram Sang return addr; 55091ed5349SWolfram Sang } 55191ed5349SWolfram Sang 55291ed5349SWolfram Sang /* This is a permissive address validity check, I2C address map constraints 55391ed5349SWolfram Sang * are purposely not enforced, except for the general call address. */ 554398432edSWolfram Sang static int i2c_check_addr_validity(unsigned int addr, unsigned short flags) 55591ed5349SWolfram Sang { 55691ed5349SWolfram Sang if (flags & I2C_CLIENT_TEN) { 55791ed5349SWolfram Sang /* 10-bit address, all values are valid */ 55891ed5349SWolfram Sang if (addr > 0x3ff) 55991ed5349SWolfram Sang return -EINVAL; 56091ed5349SWolfram Sang } else { 56191ed5349SWolfram Sang /* 7-bit address, reject the general call address */ 56291ed5349SWolfram Sang if (addr == 0x00 || addr > 0x7f) 56391ed5349SWolfram Sang return -EINVAL; 56491ed5349SWolfram Sang } 56591ed5349SWolfram Sang return 0; 56691ed5349SWolfram Sang } 56791ed5349SWolfram Sang 56891ed5349SWolfram Sang /* And this is a strict address validity check, used when probing. If a 56991ed5349SWolfram Sang * device uses a reserved address, then it shouldn't be probed. 7-bit 57091ed5349SWolfram Sang * addressing is assumed, 10-bit address devices are rare and should be 57191ed5349SWolfram Sang * explicitly enumerated. */ 572e4991ecdSWolfram Sang int i2c_check_7bit_addr_validity_strict(unsigned short addr) 57391ed5349SWolfram Sang { 57491ed5349SWolfram Sang /* 57591ed5349SWolfram Sang * Reserved addresses per I2C specification: 57691ed5349SWolfram Sang * 0x00 General call address / START byte 57791ed5349SWolfram Sang * 0x01 CBUS address 57891ed5349SWolfram Sang * 0x02 Reserved for different bus format 57991ed5349SWolfram Sang * 0x03 Reserved for future purposes 58091ed5349SWolfram Sang * 0x04-0x07 Hs-mode master code 58191ed5349SWolfram Sang * 0x78-0x7b 10-bit slave addressing 58291ed5349SWolfram Sang * 0x7c-0x7f Reserved for future purposes 58391ed5349SWolfram Sang */ 58491ed5349SWolfram Sang if (addr < 0x08 || addr > 0x77) 58591ed5349SWolfram Sang return -EINVAL; 58691ed5349SWolfram Sang return 0; 58791ed5349SWolfram Sang } 58891ed5349SWolfram Sang 58991ed5349SWolfram Sang static int __i2c_check_addr_busy(struct device *dev, void *addrp) 59091ed5349SWolfram Sang { 59191ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 59291ed5349SWolfram Sang int addr = *(int *)addrp; 59391ed5349SWolfram Sang 59491ed5349SWolfram Sang if (client && i2c_encode_flags_to_addr(client) == addr) 59591ed5349SWolfram Sang return -EBUSY; 59691ed5349SWolfram Sang return 0; 59791ed5349SWolfram Sang } 59891ed5349SWolfram Sang 59991ed5349SWolfram Sang /* walk up mux tree */ 60091ed5349SWolfram Sang static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) 60191ed5349SWolfram Sang { 60291ed5349SWolfram Sang struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); 60391ed5349SWolfram Sang int result; 60491ed5349SWolfram Sang 60591ed5349SWolfram Sang result = device_for_each_child(&adapter->dev, &addr, 60691ed5349SWolfram Sang __i2c_check_addr_busy); 60791ed5349SWolfram Sang 60891ed5349SWolfram Sang if (!result && parent) 60991ed5349SWolfram Sang result = i2c_check_mux_parents(parent, addr); 61091ed5349SWolfram Sang 61191ed5349SWolfram Sang return result; 61291ed5349SWolfram Sang } 61391ed5349SWolfram Sang 61491ed5349SWolfram Sang /* recurse down mux tree */ 61591ed5349SWolfram Sang static int i2c_check_mux_children(struct device *dev, void *addrp) 61691ed5349SWolfram Sang { 61791ed5349SWolfram Sang int result; 61891ed5349SWolfram Sang 61991ed5349SWolfram Sang if (dev->type == &i2c_adapter_type) 62091ed5349SWolfram Sang result = device_for_each_child(dev, addrp, 62191ed5349SWolfram Sang i2c_check_mux_children); 62291ed5349SWolfram Sang else 62391ed5349SWolfram Sang result = __i2c_check_addr_busy(dev, addrp); 62491ed5349SWolfram Sang 62591ed5349SWolfram Sang return result; 62691ed5349SWolfram Sang } 62791ed5349SWolfram Sang 62891ed5349SWolfram Sang static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) 62991ed5349SWolfram Sang { 63091ed5349SWolfram Sang struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); 63191ed5349SWolfram Sang int result = 0; 63291ed5349SWolfram Sang 63391ed5349SWolfram Sang if (parent) 63491ed5349SWolfram Sang result = i2c_check_mux_parents(parent, addr); 63591ed5349SWolfram Sang 63691ed5349SWolfram Sang if (!result) 63791ed5349SWolfram Sang result = device_for_each_child(&adapter->dev, &addr, 63891ed5349SWolfram Sang i2c_check_mux_children); 63991ed5349SWolfram Sang 64091ed5349SWolfram Sang return result; 64191ed5349SWolfram Sang } 64291ed5349SWolfram Sang 64391ed5349SWolfram Sang /** 64491ed5349SWolfram Sang * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment 64591ed5349SWolfram Sang * @adapter: Target I2C bus segment 64691ed5349SWolfram Sang * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 64791ed5349SWolfram Sang * locks only this branch in the adapter tree 64891ed5349SWolfram Sang */ 64991ed5349SWolfram Sang static void i2c_adapter_lock_bus(struct i2c_adapter *adapter, 65091ed5349SWolfram Sang unsigned int flags) 65191ed5349SWolfram Sang { 6527b94ea50SPeter Rosin rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter)); 65391ed5349SWolfram Sang } 65491ed5349SWolfram Sang 65591ed5349SWolfram Sang /** 65691ed5349SWolfram Sang * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment 65791ed5349SWolfram Sang * @adapter: Target I2C bus segment 65891ed5349SWolfram Sang * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT 65991ed5349SWolfram Sang * trylocks only this branch in the adapter tree 66091ed5349SWolfram Sang */ 66191ed5349SWolfram Sang static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter, 66291ed5349SWolfram Sang unsigned int flags) 66391ed5349SWolfram Sang { 66491ed5349SWolfram Sang return rt_mutex_trylock(&adapter->bus_lock); 66591ed5349SWolfram Sang } 66691ed5349SWolfram Sang 66791ed5349SWolfram Sang /** 66891ed5349SWolfram Sang * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment 66991ed5349SWolfram Sang * @adapter: Target I2C bus segment 67091ed5349SWolfram Sang * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 67191ed5349SWolfram Sang * unlocks only this branch in the adapter tree 67291ed5349SWolfram Sang */ 67391ed5349SWolfram Sang static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter, 67491ed5349SWolfram Sang unsigned int flags) 67591ed5349SWolfram Sang { 67691ed5349SWolfram Sang rt_mutex_unlock(&adapter->bus_lock); 67791ed5349SWolfram Sang } 67891ed5349SWolfram Sang 67991ed5349SWolfram Sang static void i2c_dev_set_name(struct i2c_adapter *adap, 680728fe6ceSHans de Goede struct i2c_client *client, 681728fe6ceSHans de Goede struct i2c_board_info const *info) 68291ed5349SWolfram Sang { 68391ed5349SWolfram Sang struct acpi_device *adev = ACPI_COMPANION(&client->dev); 68491ed5349SWolfram Sang 685728fe6ceSHans de Goede if (info && info->dev_name) { 686728fe6ceSHans de Goede dev_set_name(&client->dev, "i2c-%s", info->dev_name); 687728fe6ceSHans de Goede return; 688728fe6ceSHans de Goede } 689728fe6ceSHans de Goede 69091ed5349SWolfram Sang if (adev) { 69191ed5349SWolfram Sang dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); 69291ed5349SWolfram Sang return; 69391ed5349SWolfram Sang } 69491ed5349SWolfram Sang 69591ed5349SWolfram Sang dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), 69691ed5349SWolfram Sang i2c_encode_flags_to_addr(client)); 69791ed5349SWolfram Sang } 69891ed5349SWolfram Sang 6991d7534b6SCharles Keepax int i2c_dev_irq_from_resources(const struct resource *resources, 70091ed5349SWolfram Sang unsigned int num_resources) 70191ed5349SWolfram Sang { 70291ed5349SWolfram Sang struct irq_data *irqd; 70391ed5349SWolfram Sang int i; 70491ed5349SWolfram Sang 70591ed5349SWolfram Sang for (i = 0; i < num_resources; i++) { 70691ed5349SWolfram Sang const struct resource *r = &resources[i]; 70791ed5349SWolfram Sang 70891ed5349SWolfram Sang if (resource_type(r) != IORESOURCE_IRQ) 70991ed5349SWolfram Sang continue; 71091ed5349SWolfram Sang 71191ed5349SWolfram Sang if (r->flags & IORESOURCE_BITS) { 71291ed5349SWolfram Sang irqd = irq_get_irq_data(r->start); 71391ed5349SWolfram Sang if (!irqd) 71491ed5349SWolfram Sang break; 71591ed5349SWolfram Sang 71691ed5349SWolfram Sang irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); 71791ed5349SWolfram Sang } 71891ed5349SWolfram Sang 71991ed5349SWolfram Sang return r->start; 72091ed5349SWolfram Sang } 72191ed5349SWolfram Sang 72291ed5349SWolfram Sang return 0; 72391ed5349SWolfram Sang } 72491ed5349SWolfram Sang 72591ed5349SWolfram Sang /** 7267159dbdaSHeiner Kallweit * i2c_new_client_device - instantiate an i2c device 72791ed5349SWolfram Sang * @adap: the adapter managing the device 72891ed5349SWolfram Sang * @info: describes one I2C device; bus_num is ignored 72991ed5349SWolfram Sang * Context: can sleep 73091ed5349SWolfram Sang * 73191ed5349SWolfram Sang * Create an i2c device. Binding is handled through driver model 73291ed5349SWolfram Sang * probe()/remove() methods. A driver may be bound to this device when we 73391ed5349SWolfram Sang * return from this function, or any later moment (e.g. maybe hotplugging will 73491ed5349SWolfram Sang * load the driver module). This call is not appropriate for use by mainboard 73591ed5349SWolfram Sang * initialization logic, which usually runs during an arch_initcall() long 73691ed5349SWolfram Sang * before any i2c_adapter could exist. 73791ed5349SWolfram Sang * 73891ed5349SWolfram Sang * This returns the new i2c client, which may be saved for later use with 7397159dbdaSHeiner Kallweit * i2c_unregister_device(); or an ERR_PTR to describe the error. 74091ed5349SWolfram Sang */ 741550113d4SWolfram Sang struct i2c_client * 7427159dbdaSHeiner Kallweit i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info) 74391ed5349SWolfram Sang { 74491ed5349SWolfram Sang struct i2c_client *client; 74591ed5349SWolfram Sang int status; 74691ed5349SWolfram Sang 74791ed5349SWolfram Sang client = kzalloc(sizeof *client, GFP_KERNEL); 74891ed5349SWolfram Sang if (!client) 7497159dbdaSHeiner Kallweit return ERR_PTR(-ENOMEM); 75091ed5349SWolfram Sang 75191ed5349SWolfram Sang client->adapter = adap; 75291ed5349SWolfram Sang 75391ed5349SWolfram Sang client->dev.platform_data = info->platform_data; 75491ed5349SWolfram Sang client->flags = info->flags; 75591ed5349SWolfram Sang client->addr = info->addr; 75691ed5349SWolfram Sang 75793b6604cSJim Broadus client->init_irq = info->irq; 75893b6604cSJim Broadus if (!client->init_irq) 75993b6604cSJim Broadus client->init_irq = i2c_dev_irq_from_resources(info->resources, 76091ed5349SWolfram Sang info->num_resources); 76191ed5349SWolfram Sang 76291ed5349SWolfram Sang strlcpy(client->name, info->type, sizeof(client->name)); 76391ed5349SWolfram Sang 76491ed5349SWolfram Sang status = i2c_check_addr_validity(client->addr, client->flags); 76591ed5349SWolfram Sang if (status) { 76691ed5349SWolfram Sang dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", 76791ed5349SWolfram Sang client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); 76891ed5349SWolfram Sang goto out_err_silent; 76991ed5349SWolfram Sang } 77091ed5349SWolfram Sang 77191ed5349SWolfram Sang /* Check for address business */ 77291ed5349SWolfram Sang status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client)); 77391ed5349SWolfram Sang if (status) 77491ed5349SWolfram Sang goto out_err; 77591ed5349SWolfram Sang 77691ed5349SWolfram Sang client->dev.parent = &client->adapter->dev; 77791ed5349SWolfram Sang client->dev.bus = &i2c_bus_type; 77891ed5349SWolfram Sang client->dev.type = &i2c_client_type; 77904782265SBoris Brezillon client->dev.of_node = of_node_get(info->of_node); 78091ed5349SWolfram Sang client->dev.fwnode = info->fwnode; 78191ed5349SWolfram Sang 782728fe6ceSHans de Goede i2c_dev_set_name(adap, client, info); 78391ed5349SWolfram Sang 78491ed5349SWolfram Sang if (info->properties) { 78591ed5349SWolfram Sang status = device_add_properties(&client->dev, info->properties); 78691ed5349SWolfram Sang if (status) { 78791ed5349SWolfram Sang dev_err(&adap->dev, 78891ed5349SWolfram Sang "Failed to add properties to client %s: %d\n", 78991ed5349SWolfram Sang client->name, status); 79004782265SBoris Brezillon goto out_err_put_of_node; 79191ed5349SWolfram Sang } 79291ed5349SWolfram Sang } 79391ed5349SWolfram Sang 79491ed5349SWolfram Sang status = device_register(&client->dev); 79591ed5349SWolfram Sang if (status) 79691ed5349SWolfram Sang goto out_free_props; 79791ed5349SWolfram Sang 79891ed5349SWolfram Sang dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", 79991ed5349SWolfram Sang client->name, dev_name(&client->dev)); 80091ed5349SWolfram Sang 80191ed5349SWolfram Sang return client; 80291ed5349SWolfram Sang 80391ed5349SWolfram Sang out_free_props: 80491ed5349SWolfram Sang if (info->properties) 80591ed5349SWolfram Sang device_remove_properties(&client->dev); 80604782265SBoris Brezillon out_err_put_of_node: 80704782265SBoris Brezillon of_node_put(info->of_node); 80891ed5349SWolfram Sang out_err: 80991ed5349SWolfram Sang dev_err(&adap->dev, 81091ed5349SWolfram Sang "Failed to register i2c client %s at 0x%02x (%d)\n", 81191ed5349SWolfram Sang client->name, client->addr, status); 81291ed5349SWolfram Sang out_err_silent: 81391ed5349SWolfram Sang kfree(client); 8147159dbdaSHeiner Kallweit return ERR_PTR(status); 8157159dbdaSHeiner Kallweit } 8167159dbdaSHeiner Kallweit EXPORT_SYMBOL_GPL(i2c_new_client_device); 8177159dbdaSHeiner Kallweit 8187159dbdaSHeiner Kallweit /** 81987e07437SWolfram Sang * i2c_unregister_device - reverse effect of i2c_new_*_device() 82087e07437SWolfram Sang * @client: value returned from i2c_new_*_device() 82191ed5349SWolfram Sang * Context: can sleep 82291ed5349SWolfram Sang */ 82391ed5349SWolfram Sang void i2c_unregister_device(struct i2c_client *client) 82491ed5349SWolfram Sang { 825689f5358SWolfram Sang if (IS_ERR_OR_NULL(client)) 8267b43dd19SAndy Shevchenko return; 827e0638fa4SLixin Wang 828e0638fa4SLixin Wang if (client->dev.of_node) { 82991ed5349SWolfram Sang of_node_clear_flag(client->dev.of_node, OF_POPULATED); 830e0638fa4SLixin Wang of_node_put(client->dev.of_node); 831e0638fa4SLixin Wang } 832e0638fa4SLixin Wang 83391ed5349SWolfram Sang if (ACPI_COMPANION(&client->dev)) 83491ed5349SWolfram Sang acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev)); 83591ed5349SWolfram Sang device_unregister(&client->dev); 83691ed5349SWolfram Sang } 83791ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_unregister_device); 83891ed5349SWolfram Sang 83991ed5349SWolfram Sang 84091ed5349SWolfram Sang static const struct i2c_device_id dummy_id[] = { 84191ed5349SWolfram Sang { "dummy", 0 }, 84291ed5349SWolfram Sang { }, 84391ed5349SWolfram Sang }; 84491ed5349SWolfram Sang 84591ed5349SWolfram Sang static int dummy_probe(struct i2c_client *client, 84691ed5349SWolfram Sang const struct i2c_device_id *id) 84791ed5349SWolfram Sang { 84891ed5349SWolfram Sang return 0; 84991ed5349SWolfram Sang } 85091ed5349SWolfram Sang 85191ed5349SWolfram Sang static int dummy_remove(struct i2c_client *client) 85291ed5349SWolfram Sang { 85391ed5349SWolfram Sang return 0; 85491ed5349SWolfram Sang } 85591ed5349SWolfram Sang 85691ed5349SWolfram Sang static struct i2c_driver dummy_driver = { 85791ed5349SWolfram Sang .driver.name = "dummy", 85891ed5349SWolfram Sang .probe = dummy_probe, 85991ed5349SWolfram Sang .remove = dummy_remove, 86091ed5349SWolfram Sang .id_table = dummy_id, 86191ed5349SWolfram Sang }; 86291ed5349SWolfram Sang 86391ed5349SWolfram Sang /** 8647159dbdaSHeiner Kallweit * i2c_new_dummy_device - return a new i2c device bound to a dummy driver 86591ed5349SWolfram Sang * @adapter: the adapter managing the device 86691ed5349SWolfram Sang * @address: seven bit address to be used 86791ed5349SWolfram Sang * Context: can sleep 86891ed5349SWolfram Sang * 86991ed5349SWolfram Sang * This returns an I2C client bound to the "dummy" driver, intended for use 87091ed5349SWolfram Sang * with devices that consume multiple addresses. Examples of such chips 87191ed5349SWolfram Sang * include various EEPROMS (like 24c04 and 24c08 models). 87291ed5349SWolfram Sang * 87391ed5349SWolfram Sang * These dummy devices have two main uses. First, most I2C and SMBus calls 87491ed5349SWolfram Sang * except i2c_transfer() need a client handle; the dummy will be that handle. 87591ed5349SWolfram Sang * And second, this prevents the specified address from being bound to a 87691ed5349SWolfram Sang * different driver. 87791ed5349SWolfram Sang * 87891ed5349SWolfram Sang * This returns the new i2c client, which should be saved for later use with 8797159dbdaSHeiner Kallweit * i2c_unregister_device(); or an ERR_PTR to describe the error. 88091ed5349SWolfram Sang */ 881550113d4SWolfram Sang struct i2c_client *i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address) 88291ed5349SWolfram Sang { 88391ed5349SWolfram Sang struct i2c_board_info info = { 88491ed5349SWolfram Sang I2C_BOARD_INFO("dummy", address), 88591ed5349SWolfram Sang }; 88691ed5349SWolfram Sang 8877159dbdaSHeiner Kallweit return i2c_new_client_device(adapter, &info); 8887159dbdaSHeiner Kallweit } 8897159dbdaSHeiner Kallweit EXPORT_SYMBOL_GPL(i2c_new_dummy_device); 8907159dbdaSHeiner Kallweit 891b8f5fe3bSHeiner Kallweit struct i2c_dummy_devres { 892b8f5fe3bSHeiner Kallweit struct i2c_client *client; 893b8f5fe3bSHeiner Kallweit }; 894b8f5fe3bSHeiner Kallweit 895b8f5fe3bSHeiner Kallweit static void devm_i2c_release_dummy(struct device *dev, void *res) 896b8f5fe3bSHeiner Kallweit { 897b8f5fe3bSHeiner Kallweit struct i2c_dummy_devres *this = res; 898b8f5fe3bSHeiner Kallweit 899b8f5fe3bSHeiner Kallweit i2c_unregister_device(this->client); 900b8f5fe3bSHeiner Kallweit } 901b8f5fe3bSHeiner Kallweit 902b8f5fe3bSHeiner Kallweit /** 903b8f5fe3bSHeiner Kallweit * devm_i2c_new_dummy_device - return a new i2c device bound to a dummy driver 904b8f5fe3bSHeiner Kallweit * @dev: device the managed resource is bound to 905b8f5fe3bSHeiner Kallweit * @adapter: the adapter managing the device 906b8f5fe3bSHeiner Kallweit * @address: seven bit address to be used 907b8f5fe3bSHeiner Kallweit * Context: can sleep 908b8f5fe3bSHeiner Kallweit * 909b8f5fe3bSHeiner Kallweit * This is the device-managed version of @i2c_new_dummy_device. It returns the 910b8f5fe3bSHeiner Kallweit * new i2c client or an ERR_PTR in case of an error. 911b8f5fe3bSHeiner Kallweit */ 912b8f5fe3bSHeiner Kallweit struct i2c_client *devm_i2c_new_dummy_device(struct device *dev, 913b8f5fe3bSHeiner Kallweit struct i2c_adapter *adapter, 914b8f5fe3bSHeiner Kallweit u16 address) 915b8f5fe3bSHeiner Kallweit { 916b8f5fe3bSHeiner Kallweit struct i2c_dummy_devres *dr; 917b8f5fe3bSHeiner Kallweit struct i2c_client *client; 918b8f5fe3bSHeiner Kallweit 919b8f5fe3bSHeiner Kallweit dr = devres_alloc(devm_i2c_release_dummy, sizeof(*dr), GFP_KERNEL); 920b8f5fe3bSHeiner Kallweit if (!dr) 921b8f5fe3bSHeiner Kallweit return ERR_PTR(-ENOMEM); 922b8f5fe3bSHeiner Kallweit 923b8f5fe3bSHeiner Kallweit client = i2c_new_dummy_device(adapter, address); 924b8f5fe3bSHeiner Kallweit if (IS_ERR(client)) { 925b8f5fe3bSHeiner Kallweit devres_free(dr); 926b8f5fe3bSHeiner Kallweit } else { 927b8f5fe3bSHeiner Kallweit dr->client = client; 928b8f5fe3bSHeiner Kallweit devres_add(dev, dr); 929b8f5fe3bSHeiner Kallweit } 930b8f5fe3bSHeiner Kallweit 931b8f5fe3bSHeiner Kallweit return client; 932b8f5fe3bSHeiner Kallweit } 933b8f5fe3bSHeiner Kallweit EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device); 934b8f5fe3bSHeiner Kallweit 93591ed5349SWolfram Sang /** 936af80559bSWolfram Sang * i2c_new_ancillary_device - Helper to get the instantiated secondary address 93791ed5349SWolfram Sang * and create the associated device 93891ed5349SWolfram Sang * @client: Handle to the primary client 93991ed5349SWolfram Sang * @name: Handle to specify which secondary address to get 94091ed5349SWolfram Sang * @default_addr: Used as a fallback if no secondary address was specified 94191ed5349SWolfram Sang * Context: can sleep 94291ed5349SWolfram Sang * 94391ed5349SWolfram Sang * I2C clients can be composed of multiple I2C slaves bound together in a single 94491ed5349SWolfram Sang * component. The I2C client driver then binds to the master I2C slave and needs 94591ed5349SWolfram Sang * to create I2C dummy clients to communicate with all the other slaves. 94691ed5349SWolfram Sang * 94791ed5349SWolfram Sang * This function creates and returns an I2C dummy client whose I2C address is 94891ed5349SWolfram Sang * retrieved from the platform firmware based on the given slave name. If no 94991ed5349SWolfram Sang * address is specified by the firmware default_addr is used. 95091ed5349SWolfram Sang * 95191ed5349SWolfram Sang * On DT-based platforms the address is retrieved from the "reg" property entry 95291ed5349SWolfram Sang * cell whose "reg-names" value matches the slave name. 95391ed5349SWolfram Sang * 95491ed5349SWolfram Sang * This returns the new i2c client, which should be saved for later use with 955af80559bSWolfram Sang * i2c_unregister_device(); or an ERR_PTR to describe the error. 95691ed5349SWolfram Sang */ 957af80559bSWolfram Sang struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client, 95891ed5349SWolfram Sang const char *name, 95991ed5349SWolfram Sang u16 default_addr) 96091ed5349SWolfram Sang { 96191ed5349SWolfram Sang struct device_node *np = client->dev.of_node; 96291ed5349SWolfram Sang u32 addr = default_addr; 96391ed5349SWolfram Sang int i; 96491ed5349SWolfram Sang 96591ed5349SWolfram Sang if (np) { 96691ed5349SWolfram Sang i = of_property_match_string(np, "reg-names", name); 96791ed5349SWolfram Sang if (i >= 0) 96891ed5349SWolfram Sang of_property_read_u32_index(np, "reg", i, &addr); 96991ed5349SWolfram Sang } 97091ed5349SWolfram Sang 97191ed5349SWolfram Sang dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr); 972af80559bSWolfram Sang return i2c_new_dummy_device(client->adapter, addr); 97391ed5349SWolfram Sang } 974af80559bSWolfram Sang EXPORT_SYMBOL_GPL(i2c_new_ancillary_device); 97591ed5349SWolfram Sang 97691ed5349SWolfram Sang /* ------------------------------------------------------------------------- */ 97791ed5349SWolfram Sang 97891ed5349SWolfram Sang /* I2C bus adapters -- one roots each I2C or SMBUS segment */ 97991ed5349SWolfram Sang 98091ed5349SWolfram Sang static void i2c_adapter_dev_release(struct device *dev) 98191ed5349SWolfram Sang { 98291ed5349SWolfram Sang struct i2c_adapter *adap = to_i2c_adapter(dev); 98391ed5349SWolfram Sang complete(&adap->dev_released); 98491ed5349SWolfram Sang } 98591ed5349SWolfram Sang 98691ed5349SWolfram Sang unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) 98791ed5349SWolfram Sang { 98891ed5349SWolfram Sang unsigned int depth = 0; 98991ed5349SWolfram Sang 99091ed5349SWolfram Sang while ((adapter = i2c_parent_is_i2c_adapter(adapter))) 99191ed5349SWolfram Sang depth++; 99291ed5349SWolfram Sang 99391ed5349SWolfram Sang WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES, 99491ed5349SWolfram Sang "adapter depth exceeds lockdep subclass limit\n"); 99591ed5349SWolfram Sang 99691ed5349SWolfram Sang return depth; 99791ed5349SWolfram Sang } 99891ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_adapter_depth); 99991ed5349SWolfram Sang 100091ed5349SWolfram Sang /* 100191ed5349SWolfram Sang * Let users instantiate I2C devices through sysfs. This can be used when 100291ed5349SWolfram Sang * platform initialization code doesn't contain the proper data for 100391ed5349SWolfram Sang * whatever reason. Also useful for drivers that do device detection and 100491ed5349SWolfram Sang * detection fails, either because the device uses an unexpected address, 100591ed5349SWolfram Sang * or this is a compatible device with different ID register values. 100691ed5349SWolfram Sang * 100791ed5349SWolfram Sang * Parameter checking may look overzealous, but we really don't want 100891ed5349SWolfram Sang * the user to provide incorrect parameters. 100991ed5349SWolfram Sang */ 101091ed5349SWolfram Sang static ssize_t 101154a19fd4SGeert Uytterhoeven new_device_store(struct device *dev, struct device_attribute *attr, 101291ed5349SWolfram Sang const char *buf, size_t count) 101391ed5349SWolfram Sang { 101491ed5349SWolfram Sang struct i2c_adapter *adap = to_i2c_adapter(dev); 101591ed5349SWolfram Sang struct i2c_board_info info; 101691ed5349SWolfram Sang struct i2c_client *client; 101791ed5349SWolfram Sang char *blank, end; 101891ed5349SWolfram Sang int res; 101991ed5349SWolfram Sang 102091ed5349SWolfram Sang memset(&info, 0, sizeof(struct i2c_board_info)); 102191ed5349SWolfram Sang 102291ed5349SWolfram Sang blank = strchr(buf, ' '); 102391ed5349SWolfram Sang if (!blank) { 102491ed5349SWolfram Sang dev_err(dev, "%s: Missing parameters\n", "new_device"); 102591ed5349SWolfram Sang return -EINVAL; 102691ed5349SWolfram Sang } 102791ed5349SWolfram Sang if (blank - buf > I2C_NAME_SIZE - 1) { 102891ed5349SWolfram Sang dev_err(dev, "%s: Invalid device name\n", "new_device"); 102991ed5349SWolfram Sang return -EINVAL; 103091ed5349SWolfram Sang } 103191ed5349SWolfram Sang memcpy(info.type, buf, blank - buf); 103291ed5349SWolfram Sang 103391ed5349SWolfram Sang /* Parse remaining parameters, reject extra parameters */ 103491ed5349SWolfram Sang res = sscanf(++blank, "%hi%c", &info.addr, &end); 103591ed5349SWolfram Sang if (res < 1) { 103691ed5349SWolfram Sang dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); 103791ed5349SWolfram Sang return -EINVAL; 103891ed5349SWolfram Sang } 103991ed5349SWolfram Sang if (res > 1 && end != '\n') { 104091ed5349SWolfram Sang dev_err(dev, "%s: Extra parameters\n", "new_device"); 104191ed5349SWolfram Sang return -EINVAL; 104291ed5349SWolfram Sang } 104391ed5349SWolfram Sang 104491ed5349SWolfram Sang if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) { 104591ed5349SWolfram Sang info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT; 104691ed5349SWolfram Sang info.flags |= I2C_CLIENT_TEN; 104791ed5349SWolfram Sang } 104891ed5349SWolfram Sang 104991ed5349SWolfram Sang if (info.addr & I2C_ADDR_OFFSET_SLAVE) { 105091ed5349SWolfram Sang info.addr &= ~I2C_ADDR_OFFSET_SLAVE; 105191ed5349SWolfram Sang info.flags |= I2C_CLIENT_SLAVE; 105291ed5349SWolfram Sang } 105391ed5349SWolfram Sang 10547159dbdaSHeiner Kallweit client = i2c_new_client_device(adap, &info); 10557159dbdaSHeiner Kallweit if (IS_ERR(client)) 10567159dbdaSHeiner Kallweit return PTR_ERR(client); 105791ed5349SWolfram Sang 105891ed5349SWolfram Sang /* Keep track of the added device */ 105991ed5349SWolfram Sang mutex_lock(&adap->userspace_clients_lock); 106091ed5349SWolfram Sang list_add_tail(&client->detected, &adap->userspace_clients); 106191ed5349SWolfram Sang mutex_unlock(&adap->userspace_clients_lock); 106291ed5349SWolfram Sang dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", 106391ed5349SWolfram Sang info.type, info.addr); 106491ed5349SWolfram Sang 106591ed5349SWolfram Sang return count; 106691ed5349SWolfram Sang } 106754a19fd4SGeert Uytterhoeven static DEVICE_ATTR_WO(new_device); 106891ed5349SWolfram Sang 106991ed5349SWolfram Sang /* 107091ed5349SWolfram Sang * And of course let the users delete the devices they instantiated, if 107191ed5349SWolfram Sang * they got it wrong. This interface can only be used to delete devices 107291ed5349SWolfram Sang * instantiated by i2c_sysfs_new_device above. This guarantees that we 107391ed5349SWolfram Sang * don't delete devices to which some kernel code still has references. 107491ed5349SWolfram Sang * 107591ed5349SWolfram Sang * Parameter checking may look overzealous, but we really don't want 107691ed5349SWolfram Sang * the user to delete the wrong device. 107791ed5349SWolfram Sang */ 107891ed5349SWolfram Sang static ssize_t 107954a19fd4SGeert Uytterhoeven delete_device_store(struct device *dev, struct device_attribute *attr, 108091ed5349SWolfram Sang const char *buf, size_t count) 108191ed5349SWolfram Sang { 108291ed5349SWolfram Sang struct i2c_adapter *adap = to_i2c_adapter(dev); 108391ed5349SWolfram Sang struct i2c_client *client, *next; 108491ed5349SWolfram Sang unsigned short addr; 108591ed5349SWolfram Sang char end; 108691ed5349SWolfram Sang int res; 108791ed5349SWolfram Sang 108891ed5349SWolfram Sang /* Parse parameters, reject extra parameters */ 108991ed5349SWolfram Sang res = sscanf(buf, "%hi%c", &addr, &end); 109091ed5349SWolfram Sang if (res < 1) { 109191ed5349SWolfram Sang dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); 109291ed5349SWolfram Sang return -EINVAL; 109391ed5349SWolfram Sang } 109491ed5349SWolfram Sang if (res > 1 && end != '\n') { 109591ed5349SWolfram Sang dev_err(dev, "%s: Extra parameters\n", "delete_device"); 109691ed5349SWolfram Sang return -EINVAL; 109791ed5349SWolfram Sang } 109891ed5349SWolfram Sang 109991ed5349SWolfram Sang /* Make sure the device was added through sysfs */ 110091ed5349SWolfram Sang res = -ENOENT; 110191ed5349SWolfram Sang mutex_lock_nested(&adap->userspace_clients_lock, 110291ed5349SWolfram Sang i2c_adapter_depth(adap)); 110391ed5349SWolfram Sang list_for_each_entry_safe(client, next, &adap->userspace_clients, 110491ed5349SWolfram Sang detected) { 110591ed5349SWolfram Sang if (i2c_encode_flags_to_addr(client) == addr) { 110691ed5349SWolfram Sang dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", 110791ed5349SWolfram Sang "delete_device", client->name, client->addr); 110891ed5349SWolfram Sang 110991ed5349SWolfram Sang list_del(&client->detected); 111091ed5349SWolfram Sang i2c_unregister_device(client); 111191ed5349SWolfram Sang res = count; 111291ed5349SWolfram Sang break; 111391ed5349SWolfram Sang } 111491ed5349SWolfram Sang } 111591ed5349SWolfram Sang mutex_unlock(&adap->userspace_clients_lock); 111691ed5349SWolfram Sang 111791ed5349SWolfram Sang if (res < 0) 111891ed5349SWolfram Sang dev_err(dev, "%s: Can't find device in list\n", 111991ed5349SWolfram Sang "delete_device"); 112091ed5349SWolfram Sang return res; 112191ed5349SWolfram Sang } 112291ed5349SWolfram Sang static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, 112354a19fd4SGeert Uytterhoeven delete_device_store); 112491ed5349SWolfram Sang 112591ed5349SWolfram Sang static struct attribute *i2c_adapter_attrs[] = { 112691ed5349SWolfram Sang &dev_attr_name.attr, 112791ed5349SWolfram Sang &dev_attr_new_device.attr, 112891ed5349SWolfram Sang &dev_attr_delete_device.attr, 112991ed5349SWolfram Sang NULL 113091ed5349SWolfram Sang }; 113191ed5349SWolfram Sang ATTRIBUTE_GROUPS(i2c_adapter); 113291ed5349SWolfram Sang 113391ed5349SWolfram Sang struct device_type i2c_adapter_type = { 113491ed5349SWolfram Sang .groups = i2c_adapter_groups, 113591ed5349SWolfram Sang .release = i2c_adapter_dev_release, 113691ed5349SWolfram Sang }; 113791ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_adapter_type); 113891ed5349SWolfram Sang 113991ed5349SWolfram Sang /** 114091ed5349SWolfram Sang * i2c_verify_adapter - return parameter as i2c_adapter or NULL 114191ed5349SWolfram Sang * @dev: device, probably from some driver model iterator 114291ed5349SWolfram Sang * 114391ed5349SWolfram Sang * When traversing the driver model tree, perhaps using driver model 114491ed5349SWolfram Sang * iterators like @device_for_each_child(), you can't assume very much 114591ed5349SWolfram Sang * about the nodes you find. Use this function to avoid oopses caused 114691ed5349SWolfram Sang * by wrongly treating some non-I2C device as an i2c_adapter. 114791ed5349SWolfram Sang */ 114891ed5349SWolfram Sang struct i2c_adapter *i2c_verify_adapter(struct device *dev) 114991ed5349SWolfram Sang { 115091ed5349SWolfram Sang return (dev->type == &i2c_adapter_type) 115191ed5349SWolfram Sang ? to_i2c_adapter(dev) 115291ed5349SWolfram Sang : NULL; 115391ed5349SWolfram Sang } 115491ed5349SWolfram Sang EXPORT_SYMBOL(i2c_verify_adapter); 115591ed5349SWolfram Sang 115691ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 115791ed5349SWolfram Sang static struct class_compat *i2c_adapter_compat_class; 115891ed5349SWolfram Sang #endif 115991ed5349SWolfram Sang 116091ed5349SWolfram Sang static void i2c_scan_static_board_info(struct i2c_adapter *adapter) 116191ed5349SWolfram Sang { 116291ed5349SWolfram Sang struct i2c_devinfo *devinfo; 116391ed5349SWolfram Sang 116491ed5349SWolfram Sang down_read(&__i2c_board_lock); 116591ed5349SWolfram Sang list_for_each_entry(devinfo, &__i2c_board_list, list) { 116687e07437SWolfram Sang if (devinfo->busnum == adapter->nr && 116787e07437SWolfram Sang IS_ERR(i2c_new_client_device(adapter, &devinfo->board_info))) 116891ed5349SWolfram Sang dev_err(&adapter->dev, 116991ed5349SWolfram Sang "Can't create device at 0x%02x\n", 117091ed5349SWolfram Sang devinfo->board_info.addr); 117191ed5349SWolfram Sang } 117291ed5349SWolfram Sang up_read(&__i2c_board_lock); 117391ed5349SWolfram Sang } 117491ed5349SWolfram Sang 117591ed5349SWolfram Sang static int i2c_do_add_adapter(struct i2c_driver *driver, 117691ed5349SWolfram Sang struct i2c_adapter *adap) 117791ed5349SWolfram Sang { 117891ed5349SWolfram Sang /* Detect supported devices on that bus, and instantiate them */ 117991ed5349SWolfram Sang i2c_detect(adap, driver); 118091ed5349SWolfram Sang 118191ed5349SWolfram Sang return 0; 118291ed5349SWolfram Sang } 118391ed5349SWolfram Sang 118491ed5349SWolfram Sang static int __process_new_adapter(struct device_driver *d, void *data) 118591ed5349SWolfram Sang { 118691ed5349SWolfram Sang return i2c_do_add_adapter(to_i2c_driver(d), data); 118791ed5349SWolfram Sang } 118891ed5349SWolfram Sang 118991ed5349SWolfram Sang static const struct i2c_lock_operations i2c_adapter_lock_ops = { 119091ed5349SWolfram Sang .lock_bus = i2c_adapter_lock_bus, 119191ed5349SWolfram Sang .trylock_bus = i2c_adapter_trylock_bus, 119291ed5349SWolfram Sang .unlock_bus = i2c_adapter_unlock_bus, 119391ed5349SWolfram Sang }; 119491ed5349SWolfram Sang 119591ed5349SWolfram Sang static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap) 119691ed5349SWolfram Sang { 119791ed5349SWolfram Sang struct irq_domain *domain = adap->host_notify_domain; 119891ed5349SWolfram Sang irq_hw_number_t hwirq; 119991ed5349SWolfram Sang 120091ed5349SWolfram Sang if (!domain) 120191ed5349SWolfram Sang return; 120291ed5349SWolfram Sang 120391ed5349SWolfram Sang for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++) 120491ed5349SWolfram Sang irq_dispose_mapping(irq_find_mapping(domain, hwirq)); 120591ed5349SWolfram Sang 120691ed5349SWolfram Sang irq_domain_remove(domain); 120791ed5349SWolfram Sang adap->host_notify_domain = NULL; 120891ed5349SWolfram Sang } 120991ed5349SWolfram Sang 121091ed5349SWolfram Sang static int i2c_host_notify_irq_map(struct irq_domain *h, 121191ed5349SWolfram Sang unsigned int virq, 121291ed5349SWolfram Sang irq_hw_number_t hw_irq_num) 121391ed5349SWolfram Sang { 121491ed5349SWolfram Sang irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq); 121591ed5349SWolfram Sang 121691ed5349SWolfram Sang return 0; 121791ed5349SWolfram Sang } 121891ed5349SWolfram Sang 121991ed5349SWolfram Sang static const struct irq_domain_ops i2c_host_notify_irq_ops = { 122091ed5349SWolfram Sang .map = i2c_host_notify_irq_map, 122191ed5349SWolfram Sang }; 122291ed5349SWolfram Sang 122391ed5349SWolfram Sang static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap) 122491ed5349SWolfram Sang { 122591ed5349SWolfram Sang struct irq_domain *domain; 122691ed5349SWolfram Sang 122791ed5349SWolfram Sang if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY)) 122891ed5349SWolfram Sang return 0; 122991ed5349SWolfram Sang 123091ed5349SWolfram Sang domain = irq_domain_create_linear(adap->dev.fwnode, 123191ed5349SWolfram Sang I2C_ADDR_7BITS_COUNT, 123291ed5349SWolfram Sang &i2c_host_notify_irq_ops, adap); 123391ed5349SWolfram Sang if (!domain) 123491ed5349SWolfram Sang return -ENOMEM; 123591ed5349SWolfram Sang 123691ed5349SWolfram Sang adap->host_notify_domain = domain; 123791ed5349SWolfram Sang 123891ed5349SWolfram Sang return 0; 123991ed5349SWolfram Sang } 124091ed5349SWolfram Sang 124191ed5349SWolfram Sang /** 124291ed5349SWolfram Sang * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct 124391ed5349SWolfram Sang * I2C client. 124491ed5349SWolfram Sang * @adap: the adapter 124591ed5349SWolfram Sang * @addr: the I2C address of the notifying device 124691ed5349SWolfram Sang * Context: can't sleep 124791ed5349SWolfram Sang * 124891ed5349SWolfram Sang * Helper function to be called from an I2C bus driver's interrupt 124991ed5349SWolfram Sang * handler. It will schedule the Host Notify IRQ. 125091ed5349SWolfram Sang */ 125191ed5349SWolfram Sang int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr) 125291ed5349SWolfram Sang { 125391ed5349SWolfram Sang int irq; 125491ed5349SWolfram Sang 125591ed5349SWolfram Sang if (!adap) 125691ed5349SWolfram Sang return -EINVAL; 125791ed5349SWolfram Sang 125891ed5349SWolfram Sang irq = irq_find_mapping(adap->host_notify_domain, addr); 125991ed5349SWolfram Sang if (irq <= 0) 126091ed5349SWolfram Sang return -ENXIO; 126191ed5349SWolfram Sang 126291ed5349SWolfram Sang generic_handle_irq(irq); 126391ed5349SWolfram Sang 126491ed5349SWolfram Sang return 0; 126591ed5349SWolfram Sang } 126691ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify); 126791ed5349SWolfram Sang 126891ed5349SWolfram Sang static int i2c_register_adapter(struct i2c_adapter *adap) 126991ed5349SWolfram Sang { 127091ed5349SWolfram Sang int res = -EINVAL; 127191ed5349SWolfram Sang 127291ed5349SWolfram Sang /* Can't register until after driver model init */ 127391ed5349SWolfram Sang if (WARN_ON(!is_registered)) { 127491ed5349SWolfram Sang res = -EAGAIN; 127591ed5349SWolfram Sang goto out_list; 127691ed5349SWolfram Sang } 127791ed5349SWolfram Sang 127891ed5349SWolfram Sang /* Sanity checks */ 127991ed5349SWolfram Sang if (WARN(!adap->name[0], "i2c adapter has no name")) 128091ed5349SWolfram Sang goto out_list; 128191ed5349SWolfram Sang 128291ed5349SWolfram Sang if (!adap->algo) { 128391ed5349SWolfram Sang pr_err("adapter '%s': no algo supplied!\n", adap->name); 128491ed5349SWolfram Sang goto out_list; 128591ed5349SWolfram Sang } 128691ed5349SWolfram Sang 128791ed5349SWolfram Sang if (!adap->lock_ops) 128891ed5349SWolfram Sang adap->lock_ops = &i2c_adapter_lock_ops; 128991ed5349SWolfram Sang 12909ac6cb5fSWolfram Sang adap->locked_flags = 0; 129191ed5349SWolfram Sang rt_mutex_init(&adap->bus_lock); 129291ed5349SWolfram Sang rt_mutex_init(&adap->mux_lock); 129391ed5349SWolfram Sang mutex_init(&adap->userspace_clients_lock); 129491ed5349SWolfram Sang INIT_LIST_HEAD(&adap->userspace_clients); 129591ed5349SWolfram Sang 129691ed5349SWolfram Sang /* Set default timeout to 1 second if not already set */ 129791ed5349SWolfram Sang if (adap->timeout == 0) 129891ed5349SWolfram Sang adap->timeout = HZ; 129991ed5349SWolfram Sang 130091ed5349SWolfram Sang /* register soft irqs for Host Notify */ 130191ed5349SWolfram Sang res = i2c_setup_host_notify_irq_domain(adap); 130291ed5349SWolfram Sang if (res) { 130391ed5349SWolfram Sang pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n", 130491ed5349SWolfram Sang adap->name, res); 130591ed5349SWolfram Sang goto out_list; 130691ed5349SWolfram Sang } 130791ed5349SWolfram Sang 130891ed5349SWolfram Sang dev_set_name(&adap->dev, "i2c-%d", adap->nr); 130991ed5349SWolfram Sang adap->dev.bus = &i2c_bus_type; 131091ed5349SWolfram Sang adap->dev.type = &i2c_adapter_type; 131191ed5349SWolfram Sang res = device_register(&adap->dev); 131291ed5349SWolfram Sang if (res) { 131391ed5349SWolfram Sang pr_err("adapter '%s': can't register device (%d)\n", adap->name, res); 131491ed5349SWolfram Sang goto out_list; 131591ed5349SWolfram Sang } 131691ed5349SWolfram Sang 1317f8756c67SPhil Reid res = of_i2c_setup_smbus_alert(adap); 1318f8756c67SPhil Reid if (res) 1319f8756c67SPhil Reid goto out_reg; 1320f8756c67SPhil Reid 132191ed5349SWolfram Sang dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); 132291ed5349SWolfram Sang 132391ed5349SWolfram Sang pm_runtime_no_callbacks(&adap->dev); 132491ed5349SWolfram Sang pm_suspend_ignore_children(&adap->dev, true); 132591ed5349SWolfram Sang pm_runtime_enable(&adap->dev); 132691ed5349SWolfram Sang 132791ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 132891ed5349SWolfram Sang res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, 132991ed5349SWolfram Sang adap->dev.parent); 133091ed5349SWolfram Sang if (res) 133191ed5349SWolfram Sang dev_warn(&adap->dev, 133291ed5349SWolfram Sang "Failed to create compatibility class link\n"); 133391ed5349SWolfram Sang #endif 133491ed5349SWolfram Sang 133591ed5349SWolfram Sang i2c_init_recovery(adap); 133691ed5349SWolfram Sang 133791ed5349SWolfram Sang /* create pre-declared device nodes */ 133891ed5349SWolfram Sang of_i2c_register_devices(adap); 133991ed5349SWolfram Sang i2c_acpi_register_devices(adap); 134091ed5349SWolfram Sang i2c_acpi_install_space_handler(adap); 134191ed5349SWolfram Sang 134291ed5349SWolfram Sang if (adap->nr < __i2c_first_dynamic_bus_num) 134391ed5349SWolfram Sang i2c_scan_static_board_info(adap); 134491ed5349SWolfram Sang 134591ed5349SWolfram Sang /* Notify drivers */ 134691ed5349SWolfram Sang mutex_lock(&core_lock); 134791ed5349SWolfram Sang bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); 134891ed5349SWolfram Sang mutex_unlock(&core_lock); 134991ed5349SWolfram Sang 135091ed5349SWolfram Sang return 0; 135191ed5349SWolfram Sang 1352f8756c67SPhil Reid out_reg: 1353f8756c67SPhil Reid init_completion(&adap->dev_released); 1354f8756c67SPhil Reid device_unregister(&adap->dev); 1355f8756c67SPhil Reid wait_for_completion(&adap->dev_released); 135691ed5349SWolfram Sang out_list: 135791ed5349SWolfram Sang mutex_lock(&core_lock); 135891ed5349SWolfram Sang idr_remove(&i2c_adapter_idr, adap->nr); 135991ed5349SWolfram Sang mutex_unlock(&core_lock); 136091ed5349SWolfram Sang return res; 136191ed5349SWolfram Sang } 136291ed5349SWolfram Sang 136391ed5349SWolfram Sang /** 136491ed5349SWolfram Sang * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 136591ed5349SWolfram Sang * @adap: the adapter to register (with adap->nr initialized) 136691ed5349SWolfram Sang * Context: can sleep 136791ed5349SWolfram Sang * 136891ed5349SWolfram Sang * See i2c_add_numbered_adapter() for details. 136991ed5349SWolfram Sang */ 137091ed5349SWolfram Sang static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) 137191ed5349SWolfram Sang { 137291ed5349SWolfram Sang int id; 137391ed5349SWolfram Sang 137491ed5349SWolfram Sang mutex_lock(&core_lock); 137591ed5349SWolfram Sang id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL); 137691ed5349SWolfram Sang mutex_unlock(&core_lock); 137791ed5349SWolfram Sang if (WARN(id < 0, "couldn't get idr")) 137891ed5349SWolfram Sang return id == -ENOSPC ? -EBUSY : id; 137991ed5349SWolfram Sang 138091ed5349SWolfram Sang return i2c_register_adapter(adap); 138191ed5349SWolfram Sang } 138291ed5349SWolfram Sang 138391ed5349SWolfram Sang /** 138491ed5349SWolfram Sang * i2c_add_adapter - declare i2c adapter, use dynamic bus number 138591ed5349SWolfram Sang * @adapter: the adapter to add 138691ed5349SWolfram Sang * Context: can sleep 138791ed5349SWolfram Sang * 138891ed5349SWolfram Sang * This routine is used to declare an I2C adapter when its bus number 138991ed5349SWolfram Sang * doesn't matter or when its bus number is specified by an dt alias. 139091ed5349SWolfram Sang * Examples of bases when the bus number doesn't matter: I2C adapters 139191ed5349SWolfram Sang * dynamically added by USB links or PCI plugin cards. 139291ed5349SWolfram Sang * 139391ed5349SWolfram Sang * When this returns zero, a new bus number was allocated and stored 139491ed5349SWolfram Sang * in adap->nr, and the specified adapter became available for clients. 139591ed5349SWolfram Sang * Otherwise, a negative errno value is returned. 139691ed5349SWolfram Sang */ 139791ed5349SWolfram Sang int i2c_add_adapter(struct i2c_adapter *adapter) 139891ed5349SWolfram Sang { 139991ed5349SWolfram Sang struct device *dev = &adapter->dev; 140091ed5349SWolfram Sang int id; 140191ed5349SWolfram Sang 140291ed5349SWolfram Sang if (dev->of_node) { 140391ed5349SWolfram Sang id = of_alias_get_id(dev->of_node, "i2c"); 140491ed5349SWolfram Sang if (id >= 0) { 140591ed5349SWolfram Sang adapter->nr = id; 140691ed5349SWolfram Sang return __i2c_add_numbered_adapter(adapter); 140791ed5349SWolfram Sang } 140891ed5349SWolfram Sang } 140991ed5349SWolfram Sang 141091ed5349SWolfram Sang mutex_lock(&core_lock); 141191ed5349SWolfram Sang id = idr_alloc(&i2c_adapter_idr, adapter, 141291ed5349SWolfram Sang __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); 141391ed5349SWolfram Sang mutex_unlock(&core_lock); 141491ed5349SWolfram Sang if (WARN(id < 0, "couldn't get idr")) 141591ed5349SWolfram Sang return id; 141691ed5349SWolfram Sang 141791ed5349SWolfram Sang adapter->nr = id; 141891ed5349SWolfram Sang 141991ed5349SWolfram Sang return i2c_register_adapter(adapter); 142091ed5349SWolfram Sang } 142191ed5349SWolfram Sang EXPORT_SYMBOL(i2c_add_adapter); 142291ed5349SWolfram Sang 142391ed5349SWolfram Sang /** 142491ed5349SWolfram Sang * i2c_add_numbered_adapter - declare i2c adapter, use static bus number 142591ed5349SWolfram Sang * @adap: the adapter to register (with adap->nr initialized) 142691ed5349SWolfram Sang * Context: can sleep 142791ed5349SWolfram Sang * 142891ed5349SWolfram Sang * This routine is used to declare an I2C adapter when its bus number 142991ed5349SWolfram Sang * matters. For example, use it for I2C adapters from system-on-chip CPUs, 143091ed5349SWolfram Sang * or otherwise built in to the system's mainboard, and where i2c_board_info 143191ed5349SWolfram Sang * is used to properly configure I2C devices. 143291ed5349SWolfram Sang * 143391ed5349SWolfram Sang * If the requested bus number is set to -1, then this function will behave 143491ed5349SWolfram Sang * identically to i2c_add_adapter, and will dynamically assign a bus number. 143591ed5349SWolfram Sang * 143691ed5349SWolfram Sang * If no devices have pre-been declared for this bus, then be sure to 143791ed5349SWolfram Sang * register the adapter before any dynamically allocated ones. Otherwise 143891ed5349SWolfram Sang * the required bus ID may not be available. 143991ed5349SWolfram Sang * 144091ed5349SWolfram Sang * When this returns zero, the specified adapter became available for 144191ed5349SWolfram Sang * clients using the bus number provided in adap->nr. Also, the table 144291ed5349SWolfram Sang * of I2C devices pre-declared using i2c_register_board_info() is scanned, 144391ed5349SWolfram Sang * and the appropriate driver model device nodes are created. Otherwise, a 144491ed5349SWolfram Sang * negative errno value is returned. 144591ed5349SWolfram Sang */ 144691ed5349SWolfram Sang int i2c_add_numbered_adapter(struct i2c_adapter *adap) 144791ed5349SWolfram Sang { 144891ed5349SWolfram Sang if (adap->nr == -1) /* -1 means dynamically assign bus id */ 144991ed5349SWolfram Sang return i2c_add_adapter(adap); 145091ed5349SWolfram Sang 145191ed5349SWolfram Sang return __i2c_add_numbered_adapter(adap); 145291ed5349SWolfram Sang } 145391ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); 145491ed5349SWolfram Sang 145591ed5349SWolfram Sang static void i2c_do_del_adapter(struct i2c_driver *driver, 145691ed5349SWolfram Sang struct i2c_adapter *adapter) 145791ed5349SWolfram Sang { 145891ed5349SWolfram Sang struct i2c_client *client, *_n; 145991ed5349SWolfram Sang 146091ed5349SWolfram Sang /* Remove the devices we created ourselves as the result of hardware 146191ed5349SWolfram Sang * probing (using a driver's detect method) */ 146291ed5349SWolfram Sang list_for_each_entry_safe(client, _n, &driver->clients, detected) { 146391ed5349SWolfram Sang if (client->adapter == adapter) { 146491ed5349SWolfram Sang dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", 146591ed5349SWolfram Sang client->name, client->addr); 146691ed5349SWolfram Sang list_del(&client->detected); 146791ed5349SWolfram Sang i2c_unregister_device(client); 146891ed5349SWolfram Sang } 146991ed5349SWolfram Sang } 147091ed5349SWolfram Sang } 147191ed5349SWolfram Sang 147291ed5349SWolfram Sang static int __unregister_client(struct device *dev, void *dummy) 147391ed5349SWolfram Sang { 147491ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 147591ed5349SWolfram Sang if (client && strcmp(client->name, "dummy")) 147691ed5349SWolfram Sang i2c_unregister_device(client); 147791ed5349SWolfram Sang return 0; 147891ed5349SWolfram Sang } 147991ed5349SWolfram Sang 148091ed5349SWolfram Sang static int __unregister_dummy(struct device *dev, void *dummy) 148191ed5349SWolfram Sang { 148291ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 148391ed5349SWolfram Sang i2c_unregister_device(client); 148491ed5349SWolfram Sang return 0; 148591ed5349SWolfram Sang } 148691ed5349SWolfram Sang 148791ed5349SWolfram Sang static int __process_removed_adapter(struct device_driver *d, void *data) 148891ed5349SWolfram Sang { 148991ed5349SWolfram Sang i2c_do_del_adapter(to_i2c_driver(d), data); 149091ed5349SWolfram Sang return 0; 149191ed5349SWolfram Sang } 149291ed5349SWolfram Sang 149391ed5349SWolfram Sang /** 149491ed5349SWolfram Sang * i2c_del_adapter - unregister I2C adapter 149591ed5349SWolfram Sang * @adap: the adapter being unregistered 149691ed5349SWolfram Sang * Context: can sleep 149791ed5349SWolfram Sang * 149891ed5349SWolfram Sang * This unregisters an I2C adapter which was previously registered 149991ed5349SWolfram Sang * by @i2c_add_adapter or @i2c_add_numbered_adapter. 150091ed5349SWolfram Sang */ 150191ed5349SWolfram Sang void i2c_del_adapter(struct i2c_adapter *adap) 150291ed5349SWolfram Sang { 150391ed5349SWolfram Sang struct i2c_adapter *found; 150491ed5349SWolfram Sang struct i2c_client *client, *next; 150591ed5349SWolfram Sang 150691ed5349SWolfram Sang /* First make sure that this adapter was ever added */ 150791ed5349SWolfram Sang mutex_lock(&core_lock); 150891ed5349SWolfram Sang found = idr_find(&i2c_adapter_idr, adap->nr); 150991ed5349SWolfram Sang mutex_unlock(&core_lock); 151091ed5349SWolfram Sang if (found != adap) { 151191ed5349SWolfram Sang pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name); 151291ed5349SWolfram Sang return; 151391ed5349SWolfram Sang } 151491ed5349SWolfram Sang 151591ed5349SWolfram Sang i2c_acpi_remove_space_handler(adap); 151691ed5349SWolfram Sang /* Tell drivers about this removal */ 151791ed5349SWolfram Sang mutex_lock(&core_lock); 151891ed5349SWolfram Sang bus_for_each_drv(&i2c_bus_type, NULL, adap, 151991ed5349SWolfram Sang __process_removed_adapter); 152091ed5349SWolfram Sang mutex_unlock(&core_lock); 152191ed5349SWolfram Sang 152291ed5349SWolfram Sang /* Remove devices instantiated from sysfs */ 152391ed5349SWolfram Sang mutex_lock_nested(&adap->userspace_clients_lock, 152491ed5349SWolfram Sang i2c_adapter_depth(adap)); 152591ed5349SWolfram Sang list_for_each_entry_safe(client, next, &adap->userspace_clients, 152691ed5349SWolfram Sang detected) { 152791ed5349SWolfram Sang dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, 152891ed5349SWolfram Sang client->addr); 152991ed5349SWolfram Sang list_del(&client->detected); 153091ed5349SWolfram Sang i2c_unregister_device(client); 153191ed5349SWolfram Sang } 153291ed5349SWolfram Sang mutex_unlock(&adap->userspace_clients_lock); 153391ed5349SWolfram Sang 153491ed5349SWolfram Sang /* Detach any active clients. This can't fail, thus we do not 153591ed5349SWolfram Sang * check the returned value. This is a two-pass process, because 153691ed5349SWolfram Sang * we can't remove the dummy devices during the first pass: they 153791ed5349SWolfram Sang * could have been instantiated by real devices wishing to clean 153891ed5349SWolfram Sang * them up properly, so we give them a chance to do that first. */ 153991ed5349SWolfram Sang device_for_each_child(&adap->dev, NULL, __unregister_client); 154091ed5349SWolfram Sang device_for_each_child(&adap->dev, NULL, __unregister_dummy); 154191ed5349SWolfram Sang 154291ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 154391ed5349SWolfram Sang class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, 154491ed5349SWolfram Sang adap->dev.parent); 154591ed5349SWolfram Sang #endif 154691ed5349SWolfram Sang 154791ed5349SWolfram Sang /* device name is gone after device_unregister */ 154891ed5349SWolfram Sang dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); 154991ed5349SWolfram Sang 155091ed5349SWolfram Sang pm_runtime_disable(&adap->dev); 155191ed5349SWolfram Sang 155291ed5349SWolfram Sang i2c_host_notify_irq_teardown(adap); 155391ed5349SWolfram Sang 155491ed5349SWolfram Sang /* wait until all references to the device are gone 155591ed5349SWolfram Sang * 155691ed5349SWolfram Sang * FIXME: This is old code and should ideally be replaced by an 155791ed5349SWolfram Sang * alternative which results in decoupling the lifetime of the struct 155891ed5349SWolfram Sang * device from the i2c_adapter, like spi or netdev do. Any solution 155991ed5349SWolfram Sang * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled! 156091ed5349SWolfram Sang */ 156191ed5349SWolfram Sang init_completion(&adap->dev_released); 156291ed5349SWolfram Sang device_unregister(&adap->dev); 156391ed5349SWolfram Sang wait_for_completion(&adap->dev_released); 156491ed5349SWolfram Sang 156591ed5349SWolfram Sang /* free bus id */ 156691ed5349SWolfram Sang mutex_lock(&core_lock); 156791ed5349SWolfram Sang idr_remove(&i2c_adapter_idr, adap->nr); 156891ed5349SWolfram Sang mutex_unlock(&core_lock); 156991ed5349SWolfram Sang 157091ed5349SWolfram Sang /* Clear the device structure in case this adapter is ever going to be 157191ed5349SWolfram Sang added again */ 157291ed5349SWolfram Sang memset(&adap->dev, 0, sizeof(adap->dev)); 157391ed5349SWolfram Sang } 157491ed5349SWolfram Sang EXPORT_SYMBOL(i2c_del_adapter); 157591ed5349SWolfram Sang 1576def00b32SWolfram Sang static void i2c_parse_timing(struct device *dev, char *prop_name, u32 *cur_val_p, 1577def00b32SWolfram Sang u32 def_val, bool use_def) 1578def00b32SWolfram Sang { 1579def00b32SWolfram Sang int ret; 1580def00b32SWolfram Sang 1581def00b32SWolfram Sang ret = device_property_read_u32(dev, prop_name, cur_val_p); 1582def00b32SWolfram Sang if (ret && use_def) 1583def00b32SWolfram Sang *cur_val_p = def_val; 1584def00b32SWolfram Sang 1585def00b32SWolfram Sang dev_dbg(dev, "%s: %u\n", prop_name, *cur_val_p); 1586def00b32SWolfram Sang } 1587def00b32SWolfram Sang 158891ed5349SWolfram Sang /** 158991ed5349SWolfram Sang * i2c_parse_fw_timings - get I2C related timing parameters from firmware 159091ed5349SWolfram Sang * @dev: The device to scan for I2C timing properties 159191ed5349SWolfram Sang * @t: the i2c_timings struct to be filled with values 159291ed5349SWolfram Sang * @use_defaults: bool to use sane defaults derived from the I2C specification 1593263a5646SAndy Shevchenko * when properties are not found, otherwise don't update 159491ed5349SWolfram Sang * 159591ed5349SWolfram Sang * Scan the device for the generic I2C properties describing timing parameters 159691ed5349SWolfram Sang * for the signal and fill the given struct with the results. If a property was 159791ed5349SWolfram Sang * not found and use_defaults was true, then maximum timings are assumed which 159891ed5349SWolfram Sang * are derived from the I2C specification. If use_defaults is not used, the 1599263a5646SAndy Shevchenko * results will be as before, so drivers can apply their own defaults before 1600263a5646SAndy Shevchenko * calling this helper. The latter is mainly intended for avoiding regressions 1601263a5646SAndy Shevchenko * of existing drivers which want to switch to this function. New drivers 1602263a5646SAndy Shevchenko * almost always should use the defaults. 160391ed5349SWolfram Sang */ 160491ed5349SWolfram Sang void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults) 160591ed5349SWolfram Sang { 1606def00b32SWolfram Sang bool u = use_defaults; 1607def00b32SWolfram Sang u32 d; 160891ed5349SWolfram Sang 1609def00b32SWolfram Sang i2c_parse_timing(dev, "clock-frequency", &t->bus_freq_hz, 1610def00b32SWolfram Sang I2C_MAX_STANDARD_MODE_FREQ, u); 161191ed5349SWolfram Sang 1612def00b32SWolfram Sang d = t->bus_freq_hz <= I2C_MAX_STANDARD_MODE_FREQ ? 1000 : 1613def00b32SWolfram Sang t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120; 1614def00b32SWolfram Sang i2c_parse_timing(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns, d, u); 161591ed5349SWolfram Sang 1616def00b32SWolfram Sang d = t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120; 1617def00b32SWolfram Sang i2c_parse_timing(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns, d, u); 161891ed5349SWolfram Sang 1619def00b32SWolfram Sang i2c_parse_timing(dev, "i2c-scl-internal-delay-ns", 1620def00b32SWolfram Sang &t->scl_int_delay_ns, 0, u); 1621def00b32SWolfram Sang i2c_parse_timing(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns, 1622def00b32SWolfram Sang t->scl_fall_ns, u); 1623def00b32SWolfram Sang i2c_parse_timing(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns, 0, u); 1624def00b32SWolfram Sang i2c_parse_timing(dev, "i2c-digital-filter-width-ns", 1625def00b32SWolfram Sang &t->digital_filter_width_ns, 0, u); 1626def00b32SWolfram Sang i2c_parse_timing(dev, "i2c-analog-filter-cutoff-frequency", 1627def00b32SWolfram Sang &t->analog_filter_cutoff_freq_hz, 0, u); 162891ed5349SWolfram Sang } 162991ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_parse_fw_timings); 163091ed5349SWolfram Sang 163191ed5349SWolfram Sang /* ------------------------------------------------------------------------- */ 163291ed5349SWolfram Sang 1633edd7a563SWolfram Sang int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data)) 163491ed5349SWolfram Sang { 163591ed5349SWolfram Sang int res; 163691ed5349SWolfram Sang 163791ed5349SWolfram Sang mutex_lock(&core_lock); 163891ed5349SWolfram Sang res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); 163991ed5349SWolfram Sang mutex_unlock(&core_lock); 164091ed5349SWolfram Sang 164191ed5349SWolfram Sang return res; 164291ed5349SWolfram Sang } 164391ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_for_each_dev); 164491ed5349SWolfram Sang 164591ed5349SWolfram Sang static int __process_new_driver(struct device *dev, void *data) 164691ed5349SWolfram Sang { 164791ed5349SWolfram Sang if (dev->type != &i2c_adapter_type) 164891ed5349SWolfram Sang return 0; 164991ed5349SWolfram Sang return i2c_do_add_adapter(data, to_i2c_adapter(dev)); 165091ed5349SWolfram Sang } 165191ed5349SWolfram Sang 165291ed5349SWolfram Sang /* 165391ed5349SWolfram Sang * An i2c_driver is used with one or more i2c_client (device) nodes to access 165491ed5349SWolfram Sang * i2c slave chips, on a bus instance associated with some i2c_adapter. 165591ed5349SWolfram Sang */ 165691ed5349SWolfram Sang 165791ed5349SWolfram Sang int i2c_register_driver(struct module *owner, struct i2c_driver *driver) 165891ed5349SWolfram Sang { 165991ed5349SWolfram Sang int res; 166091ed5349SWolfram Sang 166191ed5349SWolfram Sang /* Can't register until after driver model init */ 166291ed5349SWolfram Sang if (WARN_ON(!is_registered)) 166391ed5349SWolfram Sang return -EAGAIN; 166491ed5349SWolfram Sang 166591ed5349SWolfram Sang /* add the driver to the list of i2c drivers in the driver core */ 166691ed5349SWolfram Sang driver->driver.owner = owner; 166791ed5349SWolfram Sang driver->driver.bus = &i2c_bus_type; 166891ed5349SWolfram Sang INIT_LIST_HEAD(&driver->clients); 166991ed5349SWolfram Sang 167091ed5349SWolfram Sang /* When registration returns, the driver core 167191ed5349SWolfram Sang * will have called probe() for all matching-but-unbound devices. 167291ed5349SWolfram Sang */ 167391ed5349SWolfram Sang res = driver_register(&driver->driver); 167491ed5349SWolfram Sang if (res) 167591ed5349SWolfram Sang return res; 167691ed5349SWolfram Sang 167791ed5349SWolfram Sang pr_debug("driver [%s] registered\n", driver->driver.name); 167891ed5349SWolfram Sang 167991ed5349SWolfram Sang /* Walk the adapters that are already present */ 168091ed5349SWolfram Sang i2c_for_each_dev(driver, __process_new_driver); 168191ed5349SWolfram Sang 168291ed5349SWolfram Sang return 0; 168391ed5349SWolfram Sang } 168491ed5349SWolfram Sang EXPORT_SYMBOL(i2c_register_driver); 168591ed5349SWolfram Sang 168691ed5349SWolfram Sang static int __process_removed_driver(struct device *dev, void *data) 168791ed5349SWolfram Sang { 168891ed5349SWolfram Sang if (dev->type == &i2c_adapter_type) 168991ed5349SWolfram Sang i2c_do_del_adapter(data, to_i2c_adapter(dev)); 169091ed5349SWolfram Sang return 0; 169191ed5349SWolfram Sang } 169291ed5349SWolfram Sang 169391ed5349SWolfram Sang /** 169491ed5349SWolfram Sang * i2c_del_driver - unregister I2C driver 169591ed5349SWolfram Sang * @driver: the driver being unregistered 169691ed5349SWolfram Sang * Context: can sleep 169791ed5349SWolfram Sang */ 169891ed5349SWolfram Sang void i2c_del_driver(struct i2c_driver *driver) 169991ed5349SWolfram Sang { 170091ed5349SWolfram Sang i2c_for_each_dev(driver, __process_removed_driver); 170191ed5349SWolfram Sang 170291ed5349SWolfram Sang driver_unregister(&driver->driver); 170391ed5349SWolfram Sang pr_debug("driver [%s] unregistered\n", driver->driver.name); 170491ed5349SWolfram Sang } 170591ed5349SWolfram Sang EXPORT_SYMBOL(i2c_del_driver); 170691ed5349SWolfram Sang 170791ed5349SWolfram Sang /* ------------------------------------------------------------------------- */ 170891ed5349SWolfram Sang 170991ed5349SWolfram Sang struct i2c_cmd_arg { 171091ed5349SWolfram Sang unsigned cmd; 171191ed5349SWolfram Sang void *arg; 171291ed5349SWolfram Sang }; 171391ed5349SWolfram Sang 171491ed5349SWolfram Sang static int i2c_cmd(struct device *dev, void *_arg) 171591ed5349SWolfram Sang { 171691ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev); 171791ed5349SWolfram Sang struct i2c_cmd_arg *arg = _arg; 171891ed5349SWolfram Sang struct i2c_driver *driver; 171991ed5349SWolfram Sang 172091ed5349SWolfram Sang if (!client || !client->dev.driver) 172191ed5349SWolfram Sang return 0; 172291ed5349SWolfram Sang 172391ed5349SWolfram Sang driver = to_i2c_driver(client->dev.driver); 172491ed5349SWolfram Sang if (driver->command) 172591ed5349SWolfram Sang driver->command(client, arg->cmd, arg->arg); 172691ed5349SWolfram Sang return 0; 172791ed5349SWolfram Sang } 172891ed5349SWolfram Sang 172991ed5349SWolfram Sang void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) 173091ed5349SWolfram Sang { 173191ed5349SWolfram Sang struct i2c_cmd_arg cmd_arg; 173291ed5349SWolfram Sang 173391ed5349SWolfram Sang cmd_arg.cmd = cmd; 173491ed5349SWolfram Sang cmd_arg.arg = arg; 173591ed5349SWolfram Sang device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); 173691ed5349SWolfram Sang } 173791ed5349SWolfram Sang EXPORT_SYMBOL(i2c_clients_command); 173891ed5349SWolfram Sang 173991ed5349SWolfram Sang static int __init i2c_init(void) 174091ed5349SWolfram Sang { 174191ed5349SWolfram Sang int retval; 174291ed5349SWolfram Sang 174391ed5349SWolfram Sang retval = of_alias_get_highest_id("i2c"); 174491ed5349SWolfram Sang 174591ed5349SWolfram Sang down_write(&__i2c_board_lock); 174691ed5349SWolfram Sang if (retval >= __i2c_first_dynamic_bus_num) 174791ed5349SWolfram Sang __i2c_first_dynamic_bus_num = retval + 1; 174891ed5349SWolfram Sang up_write(&__i2c_board_lock); 174991ed5349SWolfram Sang 175091ed5349SWolfram Sang retval = bus_register(&i2c_bus_type); 175191ed5349SWolfram Sang if (retval) 175291ed5349SWolfram Sang return retval; 175391ed5349SWolfram Sang 175491ed5349SWolfram Sang is_registered = true; 175591ed5349SWolfram Sang 175691ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 175791ed5349SWolfram Sang i2c_adapter_compat_class = class_compat_register("i2c-adapter"); 175891ed5349SWolfram Sang if (!i2c_adapter_compat_class) { 175991ed5349SWolfram Sang retval = -ENOMEM; 176091ed5349SWolfram Sang goto bus_err; 176191ed5349SWolfram Sang } 176291ed5349SWolfram Sang #endif 176391ed5349SWolfram Sang retval = i2c_add_driver(&dummy_driver); 176491ed5349SWolfram Sang if (retval) 176591ed5349SWolfram Sang goto class_err; 176691ed5349SWolfram Sang 176791ed5349SWolfram Sang if (IS_ENABLED(CONFIG_OF_DYNAMIC)) 176891ed5349SWolfram Sang WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier)); 176991ed5349SWolfram Sang if (IS_ENABLED(CONFIG_ACPI)) 177091ed5349SWolfram Sang WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier)); 177191ed5349SWolfram Sang 177291ed5349SWolfram Sang return 0; 177391ed5349SWolfram Sang 177491ed5349SWolfram Sang class_err: 177591ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 177691ed5349SWolfram Sang class_compat_unregister(i2c_adapter_compat_class); 177791ed5349SWolfram Sang bus_err: 177891ed5349SWolfram Sang #endif 177991ed5349SWolfram Sang is_registered = false; 178091ed5349SWolfram Sang bus_unregister(&i2c_bus_type); 178191ed5349SWolfram Sang return retval; 178291ed5349SWolfram Sang } 178391ed5349SWolfram Sang 178491ed5349SWolfram Sang static void __exit i2c_exit(void) 178591ed5349SWolfram Sang { 178691ed5349SWolfram Sang if (IS_ENABLED(CONFIG_ACPI)) 178791ed5349SWolfram Sang WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier)); 178891ed5349SWolfram Sang if (IS_ENABLED(CONFIG_OF_DYNAMIC)) 178991ed5349SWolfram Sang WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier)); 179091ed5349SWolfram Sang i2c_del_driver(&dummy_driver); 179191ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT 179291ed5349SWolfram Sang class_compat_unregister(i2c_adapter_compat_class); 179391ed5349SWolfram Sang #endif 179491ed5349SWolfram Sang bus_unregister(&i2c_bus_type); 179591ed5349SWolfram Sang tracepoint_synchronize_unregister(); 179691ed5349SWolfram Sang } 179791ed5349SWolfram Sang 179891ed5349SWolfram Sang /* We must initialize early, because some subsystems register i2c drivers 179991ed5349SWolfram Sang * in subsys_initcall() code, but are linked (and initialized) before i2c. 180091ed5349SWolfram Sang */ 180191ed5349SWolfram Sang postcore_initcall(i2c_init); 180291ed5349SWolfram Sang module_exit(i2c_exit); 180391ed5349SWolfram Sang 180491ed5349SWolfram Sang /* ---------------------------------------------------- 180591ed5349SWolfram Sang * the functional interface to the i2c busses. 180691ed5349SWolfram Sang * ---------------------------------------------------- 180791ed5349SWolfram Sang */ 180891ed5349SWolfram Sang 180991ed5349SWolfram Sang /* Check if val is exceeding the quirk IFF quirk is non 0 */ 181091ed5349SWolfram Sang #define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk))) 181191ed5349SWolfram Sang 181291ed5349SWolfram Sang static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg) 181391ed5349SWolfram Sang { 181491ed5349SWolfram Sang dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n", 181591ed5349SWolfram Sang err_msg, msg->addr, msg->len, 181691ed5349SWolfram Sang msg->flags & I2C_M_RD ? "read" : "write"); 181791ed5349SWolfram Sang return -EOPNOTSUPP; 181891ed5349SWolfram Sang } 181991ed5349SWolfram Sang 182091ed5349SWolfram Sang static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) 182191ed5349SWolfram Sang { 182291ed5349SWolfram Sang const struct i2c_adapter_quirks *q = adap->quirks; 182391ed5349SWolfram Sang int max_num = q->max_num_msgs, i; 182491ed5349SWolfram Sang bool do_len_check = true; 182591ed5349SWolfram Sang 182691ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB) { 182791ed5349SWolfram Sang max_num = 2; 182891ed5349SWolfram Sang 182991ed5349SWolfram Sang /* special checks for combined messages */ 183091ed5349SWolfram Sang if (num == 2) { 183191ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD) 183291ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write"); 183391ed5349SWolfram Sang 183491ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD)) 183591ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read"); 183691ed5349SWolfram Sang 183791ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr) 183891ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr"); 183991ed5349SWolfram Sang 184091ed5349SWolfram Sang if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len)) 184191ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "msg too long"); 184291ed5349SWolfram Sang 184391ed5349SWolfram Sang if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len)) 184491ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[1], "msg too long"); 184591ed5349SWolfram Sang 184691ed5349SWolfram Sang do_len_check = false; 184791ed5349SWolfram Sang } 184891ed5349SWolfram Sang } 184991ed5349SWolfram Sang 185091ed5349SWolfram Sang if (i2c_quirk_exceeded(num, max_num)) 185191ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "too many messages"); 185291ed5349SWolfram Sang 185391ed5349SWolfram Sang for (i = 0; i < num; i++) { 185491ed5349SWolfram Sang u16 len = msgs[i].len; 185591ed5349SWolfram Sang 185691ed5349SWolfram Sang if (msgs[i].flags & I2C_M_RD) { 185791ed5349SWolfram Sang if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len)) 185891ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[i], "msg too long"); 1859d9cfe2ceSWolfram Sang 1860d9cfe2ceSWolfram Sang if (q->flags & I2C_AQ_NO_ZERO_LEN_READ && len == 0) 1861d9cfe2ceSWolfram Sang return i2c_quirk_error(adap, &msgs[i], "no zero length"); 186291ed5349SWolfram Sang } else { 186391ed5349SWolfram Sang if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len)) 186491ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[i], "msg too long"); 1865d9cfe2ceSWolfram Sang 1866d9cfe2ceSWolfram Sang if (q->flags & I2C_AQ_NO_ZERO_LEN_WRITE && len == 0) 1867d9cfe2ceSWolfram Sang return i2c_quirk_error(adap, &msgs[i], "no zero length"); 186891ed5349SWolfram Sang } 186991ed5349SWolfram Sang } 187091ed5349SWolfram Sang 187191ed5349SWolfram Sang return 0; 187291ed5349SWolfram Sang } 187391ed5349SWolfram Sang 187491ed5349SWolfram Sang /** 187591ed5349SWolfram Sang * __i2c_transfer - unlocked flavor of i2c_transfer 187691ed5349SWolfram Sang * @adap: Handle to I2C bus 187791ed5349SWolfram Sang * @msgs: One or more messages to execute before STOP is issued to 187891ed5349SWolfram Sang * terminate the operation; each message begins with a START. 187991ed5349SWolfram Sang * @num: Number of messages to be executed. 188091ed5349SWolfram Sang * 188191ed5349SWolfram Sang * Returns negative errno, else the number of messages executed. 188291ed5349SWolfram Sang * 188391ed5349SWolfram Sang * Adapter lock must be held when calling this function. No debug logging 188491ed5349SWolfram Sang * takes place. adap->algo->master_xfer existence isn't checked. 188591ed5349SWolfram Sang */ 188691ed5349SWolfram Sang int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) 188791ed5349SWolfram Sang { 188891ed5349SWolfram Sang unsigned long orig_jiffies; 188991ed5349SWolfram Sang int ret, try; 189091ed5349SWolfram Sang 18911eace834SArd Biesheuvel if (WARN_ON(!msgs || num < 1)) 18921eace834SArd Biesheuvel return -EINVAL; 18935d756112SWolfram Sang 18945d756112SWolfram Sang ret = __i2c_check_suspended(adap); 18955d756112SWolfram Sang if (ret) 18965d756112SWolfram Sang return ret; 18971eace834SArd Biesheuvel 189891ed5349SWolfram Sang if (adap->quirks && i2c_check_for_quirks(adap, msgs, num)) 189991ed5349SWolfram Sang return -EOPNOTSUPP; 190091ed5349SWolfram Sang 190150888b01SDavidlohr Bueso /* 190250888b01SDavidlohr Bueso * i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets 190391ed5349SWolfram Sang * enabled. This is an efficient way of keeping the for-loop from 190491ed5349SWolfram Sang * being executed when not needed. 190591ed5349SWolfram Sang */ 190650888b01SDavidlohr Bueso if (static_branch_unlikely(&i2c_trace_msg_key)) { 190791ed5349SWolfram Sang int i; 190891ed5349SWolfram Sang for (i = 0; i < num; i++) 190991ed5349SWolfram Sang if (msgs[i].flags & I2C_M_RD) 191091ed5349SWolfram Sang trace_i2c_read(adap, &msgs[i], i); 191191ed5349SWolfram Sang else 191291ed5349SWolfram Sang trace_i2c_write(adap, &msgs[i], i); 191391ed5349SWolfram Sang } 191491ed5349SWolfram Sang 191591ed5349SWolfram Sang /* Retry automatically on arbitration loss */ 191691ed5349SWolfram Sang orig_jiffies = jiffies; 191791ed5349SWolfram Sang for (ret = 0, try = 0; try <= adap->retries; try++) { 191863b96983SWolfram Sang if (i2c_in_atomic_xfer_mode() && adap->algo->master_xfer_atomic) 191963b96983SWolfram Sang ret = adap->algo->master_xfer_atomic(adap, msgs, num); 192063b96983SWolfram Sang else 192191ed5349SWolfram Sang ret = adap->algo->master_xfer(adap, msgs, num); 192263b96983SWolfram Sang 192391ed5349SWolfram Sang if (ret != -EAGAIN) 192491ed5349SWolfram Sang break; 192591ed5349SWolfram Sang if (time_after(jiffies, orig_jiffies + adap->timeout)) 192691ed5349SWolfram Sang break; 192791ed5349SWolfram Sang } 192891ed5349SWolfram Sang 192950888b01SDavidlohr Bueso if (static_branch_unlikely(&i2c_trace_msg_key)) { 193091ed5349SWolfram Sang int i; 193191ed5349SWolfram Sang for (i = 0; i < ret; i++) 193291ed5349SWolfram Sang if (msgs[i].flags & I2C_M_RD) 193391ed5349SWolfram Sang trace_i2c_reply(adap, &msgs[i], i); 19344a3f7691SAhbong Chang trace_i2c_result(adap, num, ret); 193591ed5349SWolfram Sang } 193691ed5349SWolfram Sang 193791ed5349SWolfram Sang return ret; 193891ed5349SWolfram Sang } 193991ed5349SWolfram Sang EXPORT_SYMBOL(__i2c_transfer); 194091ed5349SWolfram Sang 194191ed5349SWolfram Sang /** 194291ed5349SWolfram Sang * i2c_transfer - execute a single or combined I2C message 194391ed5349SWolfram Sang * @adap: Handle to I2C bus 194491ed5349SWolfram Sang * @msgs: One or more messages to execute before STOP is issued to 194591ed5349SWolfram Sang * terminate the operation; each message begins with a START. 194691ed5349SWolfram Sang * @num: Number of messages to be executed. 194791ed5349SWolfram Sang * 194891ed5349SWolfram Sang * Returns negative errno, else the number of messages executed. 194991ed5349SWolfram Sang * 195091ed5349SWolfram Sang * Note that there is no requirement that each message be sent to 195191ed5349SWolfram Sang * the same slave address, although that is the most common model. 195291ed5349SWolfram Sang */ 195391ed5349SWolfram Sang int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) 195491ed5349SWolfram Sang { 195591ed5349SWolfram Sang int ret; 195691ed5349SWolfram Sang 1957cc52612eSWolfram Sang if (!adap->algo->master_xfer) { 1958cc52612eSWolfram Sang dev_dbg(&adap->dev, "I2C level transfers not supported\n"); 1959cc52612eSWolfram Sang return -EOPNOTSUPP; 1960cc52612eSWolfram Sang } 1961cc52612eSWolfram Sang 196291ed5349SWolfram Sang /* REVISIT the fault reporting model here is weak: 196391ed5349SWolfram Sang * 196491ed5349SWolfram Sang * - When we get an error after receiving N bytes from a slave, 196591ed5349SWolfram Sang * there is no way to report "N". 196691ed5349SWolfram Sang * 196791ed5349SWolfram Sang * - When we get a NAK after transmitting N bytes to a slave, 196891ed5349SWolfram Sang * there is no way to report "N" ... or to let the master 196991ed5349SWolfram Sang * continue executing the rest of this combined message, if 197091ed5349SWolfram Sang * that's the appropriate response. 197191ed5349SWolfram Sang * 197291ed5349SWolfram Sang * - When for example "num" is two and we successfully complete 197391ed5349SWolfram Sang * the first message but get an error part way through the 197491ed5349SWolfram Sang * second, it's unclear whether that should be reported as 197591ed5349SWolfram Sang * one (discarding status on the second message) or errno 197691ed5349SWolfram Sang * (discarding status on the first one). 197791ed5349SWolfram Sang */ 197883c42212SWolfram Sang ret = __i2c_lock_bus_helper(adap); 197983c42212SWolfram Sang if (ret) 198083c42212SWolfram Sang return ret; 198191ed5349SWolfram Sang 198291ed5349SWolfram Sang ret = __i2c_transfer(adap, msgs, num); 198391ed5349SWolfram Sang i2c_unlock_bus(adap, I2C_LOCK_SEGMENT); 198491ed5349SWolfram Sang 198591ed5349SWolfram Sang return ret; 198691ed5349SWolfram Sang } 198791ed5349SWolfram Sang EXPORT_SYMBOL(i2c_transfer); 198891ed5349SWolfram Sang 198991ed5349SWolfram Sang /** 19908a91732bSWolfram Sang * i2c_transfer_buffer_flags - issue a single I2C message transferring data 19918a91732bSWolfram Sang * to/from a buffer 199291ed5349SWolfram Sang * @client: Handle to slave device 19938a91732bSWolfram Sang * @buf: Where the data is stored 19948a91732bSWolfram Sang * @count: How many bytes to transfer, must be less than 64k since msg.len is u16 19958a91732bSWolfram Sang * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads 199691ed5349SWolfram Sang * 19978a91732bSWolfram Sang * Returns negative errno, or else the number of bytes transferred. 199891ed5349SWolfram Sang */ 19998a91732bSWolfram Sang int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf, 20008a91732bSWolfram Sang int count, u16 flags) 200191ed5349SWolfram Sang { 200291ed5349SWolfram Sang int ret; 20038a91732bSWolfram Sang struct i2c_msg msg = { 20048a91732bSWolfram Sang .addr = client->addr, 20058a91732bSWolfram Sang .flags = flags | (client->flags & I2C_M_TEN), 20068a91732bSWolfram Sang .len = count, 20078a91732bSWolfram Sang .buf = buf, 20088a91732bSWolfram Sang }; 200991ed5349SWolfram Sang 20108a91732bSWolfram Sang ret = i2c_transfer(client->adapter, &msg, 1); 201191ed5349SWolfram Sang 201291ed5349SWolfram Sang /* 20138a91732bSWolfram Sang * If everything went ok (i.e. 1 msg transferred), return #bytes 20148a91732bSWolfram Sang * transferred, else error code. 201591ed5349SWolfram Sang */ 201691ed5349SWolfram Sang return (ret == 1) ? count : ret; 201791ed5349SWolfram Sang } 20188a91732bSWolfram Sang EXPORT_SYMBOL(i2c_transfer_buffer_flags); 201991ed5349SWolfram Sang 2020dde67eb1SPeter Rosin /** 2021dde67eb1SPeter Rosin * i2c_get_device_id - get manufacturer, part id and die revision of a device 2022dde67eb1SPeter Rosin * @client: The device to query 2023dde67eb1SPeter Rosin * @id: The queried information 2024dde67eb1SPeter Rosin * 2025dde67eb1SPeter Rosin * Returns negative errno on error, zero on success. 2026dde67eb1SPeter Rosin */ 2027dde67eb1SPeter Rosin int i2c_get_device_id(const struct i2c_client *client, 2028dde67eb1SPeter Rosin struct i2c_device_identity *id) 2029dde67eb1SPeter Rosin { 2030dde67eb1SPeter Rosin struct i2c_adapter *adap = client->adapter; 2031dde67eb1SPeter Rosin union i2c_smbus_data raw_id; 2032dde67eb1SPeter Rosin int ret; 2033dde67eb1SPeter Rosin 2034dde67eb1SPeter Rosin if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) 2035dde67eb1SPeter Rosin return -EOPNOTSUPP; 2036dde67eb1SPeter Rosin 2037dde67eb1SPeter Rosin raw_id.block[0] = 3; 2038dde67eb1SPeter Rosin ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0, 2039dde67eb1SPeter Rosin I2C_SMBUS_READ, client->addr << 1, 2040dde67eb1SPeter Rosin I2C_SMBUS_I2C_BLOCK_DATA, &raw_id); 2041dde67eb1SPeter Rosin if (ret) 2042dde67eb1SPeter Rosin return ret; 2043dde67eb1SPeter Rosin 2044dde67eb1SPeter Rosin id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4); 2045dde67eb1SPeter Rosin id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3); 2046dde67eb1SPeter Rosin id->die_revision = raw_id.block[3] & 0x7; 2047dde67eb1SPeter Rosin return 0; 2048dde67eb1SPeter Rosin } 2049dde67eb1SPeter Rosin EXPORT_SYMBOL_GPL(i2c_get_device_id); 2050dde67eb1SPeter Rosin 205191ed5349SWolfram Sang /* ---------------------------------------------------- 205291ed5349SWolfram Sang * the i2c address scanning function 205391ed5349SWolfram Sang * Will not work for 10-bit addresses! 205491ed5349SWolfram Sang * ---------------------------------------------------- 205591ed5349SWolfram Sang */ 205691ed5349SWolfram Sang 205791ed5349SWolfram Sang /* 205891ed5349SWolfram Sang * Legacy default probe function, mostly relevant for SMBus. The default 205991ed5349SWolfram Sang * probe method is a quick write, but it is known to corrupt the 24RF08 206091ed5349SWolfram Sang * EEPROMs due to a state machine bug, and could also irreversibly 206191ed5349SWolfram Sang * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, 206291ed5349SWolfram Sang * we use a short byte read instead. Also, some bus drivers don't implement 206391ed5349SWolfram Sang * quick write, so we fallback to a byte read in that case too. 206491ed5349SWolfram Sang * On x86, there is another special case for FSC hardware monitoring chips, 206591ed5349SWolfram Sang * which want regular byte reads (address 0x73.) Fortunately, these are the 206691ed5349SWolfram Sang * only known chips using this I2C address on PC hardware. 206791ed5349SWolfram Sang * Returns 1 if probe succeeded, 0 if not. 206891ed5349SWolfram Sang */ 206991ed5349SWolfram Sang static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) 207091ed5349SWolfram Sang { 207191ed5349SWolfram Sang int err; 207291ed5349SWolfram Sang union i2c_smbus_data dummy; 207391ed5349SWolfram Sang 207491ed5349SWolfram Sang #ifdef CONFIG_X86 207591ed5349SWolfram Sang if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) 207691ed5349SWolfram Sang && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) 207791ed5349SWolfram Sang err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, 207891ed5349SWolfram Sang I2C_SMBUS_BYTE_DATA, &dummy); 207991ed5349SWolfram Sang else 208091ed5349SWolfram Sang #endif 208191ed5349SWolfram Sang if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) 208291ed5349SWolfram Sang && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) 208391ed5349SWolfram Sang err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, 208491ed5349SWolfram Sang I2C_SMBUS_QUICK, NULL); 208591ed5349SWolfram Sang else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) 208691ed5349SWolfram Sang err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, 208791ed5349SWolfram Sang I2C_SMBUS_BYTE, &dummy); 208891ed5349SWolfram Sang else { 208991ed5349SWolfram Sang dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", 209091ed5349SWolfram Sang addr); 209191ed5349SWolfram Sang err = -EOPNOTSUPP; 209291ed5349SWolfram Sang } 209391ed5349SWolfram Sang 209491ed5349SWolfram Sang return err >= 0; 209591ed5349SWolfram Sang } 209691ed5349SWolfram Sang 209791ed5349SWolfram Sang static int i2c_detect_address(struct i2c_client *temp_client, 209891ed5349SWolfram Sang struct i2c_driver *driver) 209991ed5349SWolfram Sang { 210091ed5349SWolfram Sang struct i2c_board_info info; 210191ed5349SWolfram Sang struct i2c_adapter *adapter = temp_client->adapter; 210291ed5349SWolfram Sang int addr = temp_client->addr; 210391ed5349SWolfram Sang int err; 210491ed5349SWolfram Sang 210591ed5349SWolfram Sang /* Make sure the address is valid */ 210691ed5349SWolfram Sang err = i2c_check_7bit_addr_validity_strict(addr); 210791ed5349SWolfram Sang if (err) { 210891ed5349SWolfram Sang dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", 210991ed5349SWolfram Sang addr); 211091ed5349SWolfram Sang return err; 211191ed5349SWolfram Sang } 211291ed5349SWolfram Sang 211391ed5349SWolfram Sang /* Skip if already in use (7 bit, no need to encode flags) */ 211491ed5349SWolfram Sang if (i2c_check_addr_busy(adapter, addr)) 211591ed5349SWolfram Sang return 0; 211691ed5349SWolfram Sang 211791ed5349SWolfram Sang /* Make sure there is something at this address */ 211891ed5349SWolfram Sang if (!i2c_default_probe(adapter, addr)) 211991ed5349SWolfram Sang return 0; 212091ed5349SWolfram Sang 212191ed5349SWolfram Sang /* Finally call the custom detection function */ 212291ed5349SWolfram Sang memset(&info, 0, sizeof(struct i2c_board_info)); 212391ed5349SWolfram Sang info.addr = addr; 212491ed5349SWolfram Sang err = driver->detect(temp_client, &info); 212591ed5349SWolfram Sang if (err) { 212691ed5349SWolfram Sang /* -ENODEV is returned if the detection fails. We catch it 212791ed5349SWolfram Sang here as this isn't an error. */ 212891ed5349SWolfram Sang return err == -ENODEV ? 0 : err; 212991ed5349SWolfram Sang } 213091ed5349SWolfram Sang 213191ed5349SWolfram Sang /* Consistency check */ 213291ed5349SWolfram Sang if (info.type[0] == '\0') { 213391ed5349SWolfram Sang dev_err(&adapter->dev, 213491ed5349SWolfram Sang "%s detection function provided no name for 0x%x\n", 213591ed5349SWolfram Sang driver->driver.name, addr); 213691ed5349SWolfram Sang } else { 213791ed5349SWolfram Sang struct i2c_client *client; 213891ed5349SWolfram Sang 213991ed5349SWolfram Sang /* Detection succeeded, instantiate the device */ 214091ed5349SWolfram Sang if (adapter->class & I2C_CLASS_DEPRECATED) 214191ed5349SWolfram Sang dev_warn(&adapter->dev, 214291ed5349SWolfram Sang "This adapter will soon drop class based instantiation of devices. " 214391ed5349SWolfram Sang "Please make sure client 0x%02x gets instantiated by other means. " 2144ccf988b6SMauro Carvalho Chehab "Check 'Documentation/i2c/instantiating-devices.rst' for details.\n", 214591ed5349SWolfram Sang info.addr); 214691ed5349SWolfram Sang 214791ed5349SWolfram Sang dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", 214891ed5349SWolfram Sang info.type, info.addr); 214987e07437SWolfram Sang client = i2c_new_client_device(adapter, &info); 215087e07437SWolfram Sang if (!IS_ERR(client)) 215191ed5349SWolfram Sang list_add_tail(&client->detected, &driver->clients); 215291ed5349SWolfram Sang else 215391ed5349SWolfram Sang dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", 215491ed5349SWolfram Sang info.type, info.addr); 215591ed5349SWolfram Sang } 215691ed5349SWolfram Sang return 0; 215791ed5349SWolfram Sang } 215891ed5349SWolfram Sang 215991ed5349SWolfram Sang static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) 216091ed5349SWolfram Sang { 216191ed5349SWolfram Sang const unsigned short *address_list; 216291ed5349SWolfram Sang struct i2c_client *temp_client; 216391ed5349SWolfram Sang int i, err = 0; 216491ed5349SWolfram Sang 216591ed5349SWolfram Sang address_list = driver->address_list; 216691ed5349SWolfram Sang if (!driver->detect || !address_list) 216791ed5349SWolfram Sang return 0; 216891ed5349SWolfram Sang 216991ed5349SWolfram Sang /* Warn that the adapter lost class based instantiation */ 217091ed5349SWolfram Sang if (adapter->class == I2C_CLASS_DEPRECATED) { 217191ed5349SWolfram Sang dev_dbg(&adapter->dev, 217291ed5349SWolfram Sang "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. " 2173ccf988b6SMauro Carvalho Chehab "If you need it, check 'Documentation/i2c/instantiating-devices.rst' for alternatives.\n", 217491ed5349SWolfram Sang driver->driver.name); 217591ed5349SWolfram Sang return 0; 217691ed5349SWolfram Sang } 217791ed5349SWolfram Sang 217891ed5349SWolfram Sang /* Stop here if the classes do not match */ 217991ed5349SWolfram Sang if (!(adapter->class & driver->class)) 218091ed5349SWolfram Sang return 0; 218191ed5349SWolfram Sang 218291ed5349SWolfram Sang /* Set up a temporary client to help detect callback */ 218391ed5349SWolfram Sang temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); 218491ed5349SWolfram Sang if (!temp_client) 218591ed5349SWolfram Sang return -ENOMEM; 218691ed5349SWolfram Sang temp_client->adapter = adapter; 218791ed5349SWolfram Sang 218891ed5349SWolfram Sang for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { 218991ed5349SWolfram Sang dev_dbg(&adapter->dev, 219091ed5349SWolfram Sang "found normal entry for adapter %d, addr 0x%02x\n", 2191dd4f2ca9SWolfram Sang i2c_adapter_id(adapter), address_list[i]); 219291ed5349SWolfram Sang temp_client->addr = address_list[i]; 219391ed5349SWolfram Sang err = i2c_detect_address(temp_client, driver); 219491ed5349SWolfram Sang if (unlikely(err)) 219591ed5349SWolfram Sang break; 219691ed5349SWolfram Sang } 219791ed5349SWolfram Sang 219891ed5349SWolfram Sang kfree(temp_client); 219991ed5349SWolfram Sang return err; 220091ed5349SWolfram Sang } 220191ed5349SWolfram Sang 220291ed5349SWolfram Sang int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) 220391ed5349SWolfram Sang { 220491ed5349SWolfram Sang return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, 220591ed5349SWolfram Sang I2C_SMBUS_QUICK, NULL) >= 0; 220691ed5349SWolfram Sang } 220791ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); 220891ed5349SWolfram Sang 220991ed5349SWolfram Sang struct i2c_client * 2210c1d08475SWolfram Sang i2c_new_scanned_device(struct i2c_adapter *adap, 221191ed5349SWolfram Sang struct i2c_board_info *info, 221291ed5349SWolfram Sang unsigned short const *addr_list, 2213edd7a563SWolfram Sang int (*probe)(struct i2c_adapter *adap, unsigned short addr)) 221491ed5349SWolfram Sang { 221591ed5349SWolfram Sang int i; 221691ed5349SWolfram Sang 221791ed5349SWolfram Sang if (!probe) 221891ed5349SWolfram Sang probe = i2c_default_probe; 221991ed5349SWolfram Sang 222091ed5349SWolfram Sang for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { 222191ed5349SWolfram Sang /* Check address validity */ 222291ed5349SWolfram Sang if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) { 222391ed5349SWolfram Sang dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n", 222491ed5349SWolfram Sang addr_list[i]); 222591ed5349SWolfram Sang continue; 222691ed5349SWolfram Sang } 222791ed5349SWolfram Sang 222891ed5349SWolfram Sang /* Check address availability (7 bit, no need to encode flags) */ 222991ed5349SWolfram Sang if (i2c_check_addr_busy(adap, addr_list[i])) { 223091ed5349SWolfram Sang dev_dbg(&adap->dev, 223191ed5349SWolfram Sang "Address 0x%02x already in use, not probing\n", 223291ed5349SWolfram Sang addr_list[i]); 223391ed5349SWolfram Sang continue; 223491ed5349SWolfram Sang } 223591ed5349SWolfram Sang 223691ed5349SWolfram Sang /* Test address responsiveness */ 223791ed5349SWolfram Sang if (probe(adap, addr_list[i])) 223891ed5349SWolfram Sang break; 223991ed5349SWolfram Sang } 224091ed5349SWolfram Sang 224191ed5349SWolfram Sang if (addr_list[i] == I2C_CLIENT_END) { 224291ed5349SWolfram Sang dev_dbg(&adap->dev, "Probing failed, no device found\n"); 2243c1d08475SWolfram Sang return ERR_PTR(-ENODEV); 224491ed5349SWolfram Sang } 224591ed5349SWolfram Sang 224691ed5349SWolfram Sang info->addr = addr_list[i]; 2247c1d08475SWolfram Sang return i2c_new_client_device(adap, info); 2248c1d08475SWolfram Sang } 2249c1d08475SWolfram Sang EXPORT_SYMBOL_GPL(i2c_new_scanned_device); 2250c1d08475SWolfram Sang 225191ed5349SWolfram Sang struct i2c_adapter *i2c_get_adapter(int nr) 225291ed5349SWolfram Sang { 225391ed5349SWolfram Sang struct i2c_adapter *adapter; 225491ed5349SWolfram Sang 225591ed5349SWolfram Sang mutex_lock(&core_lock); 225691ed5349SWolfram Sang adapter = idr_find(&i2c_adapter_idr, nr); 225791ed5349SWolfram Sang if (!adapter) 225891ed5349SWolfram Sang goto exit; 225991ed5349SWolfram Sang 226091ed5349SWolfram Sang if (try_module_get(adapter->owner)) 226191ed5349SWolfram Sang get_device(&adapter->dev); 226291ed5349SWolfram Sang else 226391ed5349SWolfram Sang adapter = NULL; 226491ed5349SWolfram Sang 226591ed5349SWolfram Sang exit: 226691ed5349SWolfram Sang mutex_unlock(&core_lock); 226791ed5349SWolfram Sang return adapter; 226891ed5349SWolfram Sang } 226991ed5349SWolfram Sang EXPORT_SYMBOL(i2c_get_adapter); 227091ed5349SWolfram Sang 227191ed5349SWolfram Sang void i2c_put_adapter(struct i2c_adapter *adap) 227291ed5349SWolfram Sang { 227391ed5349SWolfram Sang if (!adap) 227491ed5349SWolfram Sang return; 227591ed5349SWolfram Sang 227691ed5349SWolfram Sang put_device(&adap->dev); 227791ed5349SWolfram Sang module_put(adap->owner); 227891ed5349SWolfram Sang } 227991ed5349SWolfram Sang EXPORT_SYMBOL(i2c_put_adapter); 228091ed5349SWolfram Sang 2281e94bc5d1SWolfram Sang /** 2282e94bc5d1SWolfram Sang * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg 2283e94bc5d1SWolfram Sang * @msg: the message to be checked 2284bf263c35SWolfram Sang * @threshold: the minimum number of bytes for which using DMA makes sense. 2285bf263c35SWolfram Sang * Should at least be 1. 2286e94bc5d1SWolfram Sang * 2287e94bc5d1SWolfram Sang * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO. 2288e94bc5d1SWolfram Sang * Or a valid pointer to be used with DMA. After use, release it by 228934d1b82cSStephen Boyd * calling i2c_put_dma_safe_msg_buf(). 2290e94bc5d1SWolfram Sang * 2291e94bc5d1SWolfram Sang * This function must only be called from process context! 2292e94bc5d1SWolfram Sang */ 2293e94bc5d1SWolfram Sang u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold) 2294e94bc5d1SWolfram Sang { 2295bf263c35SWolfram Sang /* also skip 0-length msgs for bogus thresholds of 0 */ 2296bf263c35SWolfram Sang if (!threshold) 2297bf263c35SWolfram Sang pr_debug("DMA buffer for addr=0x%02x with length 0 is bogus\n", 2298bf263c35SWolfram Sang msg->addr); 2299bf263c35SWolfram Sang if (msg->len < threshold || msg->len == 0) 2300e94bc5d1SWolfram Sang return NULL; 2301e94bc5d1SWolfram Sang 2302e94bc5d1SWolfram Sang if (msg->flags & I2C_M_DMA_SAFE) 2303e94bc5d1SWolfram Sang return msg->buf; 2304e94bc5d1SWolfram Sang 2305e94bc5d1SWolfram Sang pr_debug("using bounce buffer for addr=0x%02x, len=%d\n", 2306e94bc5d1SWolfram Sang msg->addr, msg->len); 2307e94bc5d1SWolfram Sang 2308e94bc5d1SWolfram Sang if (msg->flags & I2C_M_RD) 2309e94bc5d1SWolfram Sang return kzalloc(msg->len, GFP_KERNEL); 2310e94bc5d1SWolfram Sang else 2311e94bc5d1SWolfram Sang return kmemdup(msg->buf, msg->len, GFP_KERNEL); 2312e94bc5d1SWolfram Sang } 2313e94bc5d1SWolfram Sang EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf); 2314e94bc5d1SWolfram Sang 2315e94bc5d1SWolfram Sang /** 231682fe39a6SWolfram Sang * i2c_put_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg 2317e94bc5d1SWolfram Sang * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL. 231882fe39a6SWolfram Sang * @msg: the message which the buffer corresponds to 231982fe39a6SWolfram Sang * @xferred: bool saying if the message was transferred 2320e94bc5d1SWolfram Sang */ 232182fe39a6SWolfram Sang void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred) 2322e94bc5d1SWolfram Sang { 2323e94bc5d1SWolfram Sang if (!buf || buf == msg->buf) 2324e94bc5d1SWolfram Sang return; 2325e94bc5d1SWolfram Sang 232682fe39a6SWolfram Sang if (xferred && msg->flags & I2C_M_RD) 2327e94bc5d1SWolfram Sang memcpy(msg->buf, buf, msg->len); 2328e94bc5d1SWolfram Sang 2329e94bc5d1SWolfram Sang kfree(buf); 2330e94bc5d1SWolfram Sang } 233182fe39a6SWolfram Sang EXPORT_SYMBOL_GPL(i2c_put_dma_safe_msg_buf); 2332e94bc5d1SWolfram Sang 233391ed5349SWolfram Sang MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); 233491ed5349SWolfram Sang MODULE_DESCRIPTION("I2C-Bus main module"); 233591ed5349SWolfram Sang MODULE_LICENSE("GPL"); 2336