1c942fddfSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later
261e3d0f7SWolfram Sang /*
361e3d0f7SWolfram Sang * Linux I2C core
461e3d0f7SWolfram Sang *
561e3d0f7SWolfram Sang * Copyright (C) 1995-99 Simon G. Vogl
661e3d0f7SWolfram Sang * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>
761e3d0f7SWolfram Sang * Mux support by Rodolfo Giometti <giometti@enneenne.com> and
861e3d0f7SWolfram Sang * Michael Lawnick <michael.lawnick.ext@nsn.com>
961e3d0f7SWolfram Sang *
102f5a55c5SWolfram Sang * Copyright (C) 2013-2017 Wolfram Sang <wsa@kernel.org>
1191ed5349SWolfram Sang */
1291ed5349SWolfram Sang
1391ed5349SWolfram Sang #define pr_fmt(fmt) "i2c-core: " fmt
1491ed5349SWolfram Sang
1591ed5349SWolfram Sang #include <dt-bindings/i2c/i2c.h>
1691ed5349SWolfram Sang #include <linux/acpi.h>
1791ed5349SWolfram Sang #include <linux/clk/clk-conf.h>
1891ed5349SWolfram Sang #include <linux/completion.h>
1991ed5349SWolfram Sang #include <linux/delay.h>
2091ed5349SWolfram Sang #include <linux/err.h>
2191ed5349SWolfram Sang #include <linux/errno.h>
2210c9ef04SPhil Reid #include <linux/gpio/consumer.h>
2391ed5349SWolfram Sang #include <linux/i2c.h>
24f8756c67SPhil Reid #include <linux/i2c-smbus.h>
2591ed5349SWolfram Sang #include <linux/idr.h>
2691ed5349SWolfram Sang #include <linux/init.h>
27b64210f2SDmitry Torokhov #include <linux/interrupt.h>
2891ed5349SWolfram Sang #include <linux/irqflags.h>
2991ed5349SWolfram Sang #include <linux/jump_label.h>
3091ed5349SWolfram Sang #include <linux/kernel.h>
3191ed5349SWolfram Sang #include <linux/module.h>
3291ed5349SWolfram Sang #include <linux/mutex.h>
3391ed5349SWolfram Sang #include <linux/of_device.h>
3491ed5349SWolfram Sang #include <linux/of.h>
3591ed5349SWolfram Sang #include <linux/of_irq.h>
3675820314SCodrin Ciubotariu #include <linux/pinctrl/consumer.h>
3720cb3fceSHanna Hawa #include <linux/pinctrl/devinfo.h>
3891ed5349SWolfram Sang #include <linux/pm_domain.h>
3991ed5349SWolfram Sang #include <linux/pm_runtime.h>
4091ed5349SWolfram Sang #include <linux/pm_wakeirq.h>
4191ed5349SWolfram Sang #include <linux/property.h>
4291ed5349SWolfram Sang #include <linux/rwsem.h>
4391ed5349SWolfram Sang #include <linux/slab.h>
4491ed5349SWolfram Sang
4591ed5349SWolfram Sang #include "i2c-core.h"
4691ed5349SWolfram Sang
4791ed5349SWolfram Sang #define CREATE_TRACE_POINTS
4891ed5349SWolfram Sang #include <trace/events/i2c.h>
4991ed5349SWolfram Sang
5091ed5349SWolfram Sang #define I2C_ADDR_OFFSET_TEN_BIT 0xa000
5191ed5349SWolfram Sang #define I2C_ADDR_OFFSET_SLAVE 0x1000
5291ed5349SWolfram Sang
5391ed5349SWolfram Sang #define I2C_ADDR_7BITS_MAX 0x77
5491ed5349SWolfram Sang #define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1)
5591ed5349SWolfram Sang
56dde67eb1SPeter Rosin #define I2C_ADDR_DEVICE_ID 0x7c
57dde67eb1SPeter Rosin
5861e3d0f7SWolfram Sang /*
5961e3d0f7SWolfram Sang * core_lock protects i2c_adapter_idr, and guarantees that device detection,
600c36dd37SWolfram Sang * deletion of detected devices are serialized
6161e3d0f7SWolfram Sang */
6291ed5349SWolfram Sang static DEFINE_MUTEX(core_lock);
6391ed5349SWolfram Sang static DEFINE_IDR(i2c_adapter_idr);
6491ed5349SWolfram Sang
6591ed5349SWolfram Sang static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
6691ed5349SWolfram Sang
6750888b01SDavidlohr Bueso static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key);
6891ed5349SWolfram Sang static bool is_registered;
6991ed5349SWolfram Sang
i2c_transfer_trace_reg(void)7091ed5349SWolfram Sang int i2c_transfer_trace_reg(void)
7191ed5349SWolfram Sang {
7250888b01SDavidlohr Bueso static_branch_inc(&i2c_trace_msg_key);
7391ed5349SWolfram Sang return 0;
7491ed5349SWolfram Sang }
7591ed5349SWolfram Sang
i2c_transfer_trace_unreg(void)7691ed5349SWolfram Sang void i2c_transfer_trace_unreg(void)
7791ed5349SWolfram Sang {
7850888b01SDavidlohr Bueso static_branch_dec(&i2c_trace_msg_key);
7991ed5349SWolfram Sang }
8091ed5349SWolfram Sang
i2c_freq_mode_string(u32 bus_freq_hz)813b4c747cSYicong Yang const char *i2c_freq_mode_string(u32 bus_freq_hz)
823b4c747cSYicong Yang {
833b4c747cSYicong Yang switch (bus_freq_hz) {
843b4c747cSYicong Yang case I2C_MAX_STANDARD_MODE_FREQ:
853b4c747cSYicong Yang return "Standard Mode (100 kHz)";
863b4c747cSYicong Yang case I2C_MAX_FAST_MODE_FREQ:
873b4c747cSYicong Yang return "Fast Mode (400 kHz)";
883b4c747cSYicong Yang case I2C_MAX_FAST_MODE_PLUS_FREQ:
893b4c747cSYicong Yang return "Fast Mode Plus (1.0 MHz)";
903b4c747cSYicong Yang case I2C_MAX_TURBO_MODE_FREQ:
913b4c747cSYicong Yang return "Turbo Mode (1.4 MHz)";
923b4c747cSYicong Yang case I2C_MAX_HIGH_SPEED_MODE_FREQ:
933b4c747cSYicong Yang return "High Speed Mode (3.4 MHz)";
943b4c747cSYicong Yang case I2C_MAX_ULTRA_FAST_MODE_FREQ:
953b4c747cSYicong Yang return "Ultra Fast Mode (5.0 MHz)";
963b4c747cSYicong Yang default:
973b4c747cSYicong Yang return "Unknown Mode";
983b4c747cSYicong Yang }
993b4c747cSYicong Yang }
1003b4c747cSYicong Yang EXPORT_SYMBOL_GPL(i2c_freq_mode_string);
1013b4c747cSYicong Yang
i2c_match_id(const struct i2c_device_id * id,const struct i2c_client * client)10291ed5349SWolfram Sang const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
10391ed5349SWolfram Sang const struct i2c_client *client)
10491ed5349SWolfram Sang {
10591ed5349SWolfram Sang if (!(id && client))
10691ed5349SWolfram Sang return NULL;
10791ed5349SWolfram Sang
10891ed5349SWolfram Sang while (id->name[0]) {
10991ed5349SWolfram Sang if (strcmp(client->name, id->name) == 0)
11091ed5349SWolfram Sang return id;
11191ed5349SWolfram Sang id++;
11291ed5349SWolfram Sang }
11391ed5349SWolfram Sang return NULL;
11491ed5349SWolfram Sang }
11591ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_match_id);
11691ed5349SWolfram Sang
i2c_get_match_data(const struct i2c_client * client)117564d73c4SBiju Das const void *i2c_get_match_data(const struct i2c_client *client)
118564d73c4SBiju Das {
119564d73c4SBiju Das struct i2c_driver *driver = to_i2c_driver(client->dev.driver);
120564d73c4SBiju Das const struct i2c_device_id *match;
121564d73c4SBiju Das const void *data;
122564d73c4SBiju Das
123564d73c4SBiju Das data = device_get_match_data(&client->dev);
124564d73c4SBiju Das if (!data) {
125564d73c4SBiju Das match = i2c_match_id(driver->id_table, client);
126564d73c4SBiju Das if (!match)
127564d73c4SBiju Das return NULL;
128564d73c4SBiju Das
129564d73c4SBiju Das data = (const void *)match->driver_data;
130564d73c4SBiju Das }
131564d73c4SBiju Das
132564d73c4SBiju Das return data;
133564d73c4SBiju Das }
134564d73c4SBiju Das EXPORT_SYMBOL(i2c_get_match_data);
135564d73c4SBiju Das
i2c_device_match(struct device * dev,struct device_driver * drv)13691ed5349SWolfram Sang static int i2c_device_match(struct device *dev, struct device_driver *drv)
13791ed5349SWolfram Sang {
13891ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev);
13991ed5349SWolfram Sang struct i2c_driver *driver;
14091ed5349SWolfram Sang
14191ed5349SWolfram Sang
14291ed5349SWolfram Sang /* Attempt an OF style match */
14391ed5349SWolfram Sang if (i2c_of_match_device(drv->of_match_table, client))
14491ed5349SWolfram Sang return 1;
14591ed5349SWolfram Sang
14691ed5349SWolfram Sang /* Then ACPI style match */
14791ed5349SWolfram Sang if (acpi_driver_match_device(dev, drv))
14891ed5349SWolfram Sang return 1;
14991ed5349SWolfram Sang
15091ed5349SWolfram Sang driver = to_i2c_driver(drv);
15191ed5349SWolfram Sang
15291ed5349SWolfram Sang /* Finally an I2C match */
15391ed5349SWolfram Sang if (i2c_match_id(driver->id_table, client))
15491ed5349SWolfram Sang return 1;
15591ed5349SWolfram Sang
15691ed5349SWolfram Sang return 0;
15791ed5349SWolfram Sang }
15891ed5349SWolfram Sang
i2c_device_uevent(const struct device * dev,struct kobj_uevent_env * env)159162736b0SGreg Kroah-Hartman static int i2c_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
16091ed5349SWolfram Sang {
161162736b0SGreg Kroah-Hartman const struct i2c_client *client = to_i2c_client(dev);
16291ed5349SWolfram Sang int rc;
16391ed5349SWolfram Sang
164af503716SJavier Martinez Canillas rc = of_device_uevent_modalias(dev, env);
165af503716SJavier Martinez Canillas if (rc != -ENODEV)
166af503716SJavier Martinez Canillas return rc;
167af503716SJavier Martinez Canillas
16891ed5349SWolfram Sang rc = acpi_device_uevent_modalias(dev, env);
16991ed5349SWolfram Sang if (rc != -ENODEV)
17091ed5349SWolfram Sang return rc;
17191ed5349SWolfram Sang
17291ed5349SWolfram Sang return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name);
17391ed5349SWolfram Sang }
17491ed5349SWolfram Sang
17591ed5349SWolfram Sang /* i2c bus recovery routines */
get_scl_gpio_value(struct i2c_adapter * adap)17691ed5349SWolfram Sang static int get_scl_gpio_value(struct i2c_adapter *adap)
17791ed5349SWolfram Sang {
1783991c5c8SPhil Reid return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod);
17991ed5349SWolfram Sang }
18091ed5349SWolfram Sang
set_scl_gpio_value(struct i2c_adapter * adap,int val)18191ed5349SWolfram Sang static void set_scl_gpio_value(struct i2c_adapter *adap, int val)
18291ed5349SWolfram Sang {
1833991c5c8SPhil Reid gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val);
18491ed5349SWolfram Sang }
18591ed5349SWolfram Sang
get_sda_gpio_value(struct i2c_adapter * adap)18691ed5349SWolfram Sang static int get_sda_gpio_value(struct i2c_adapter *adap)
18791ed5349SWolfram Sang {
1883991c5c8SPhil Reid return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod);
18991ed5349SWolfram Sang }
19091ed5349SWolfram Sang
set_sda_gpio_value(struct i2c_adapter * adap,int val)1918092178fSWolfram Sang static void set_sda_gpio_value(struct i2c_adapter *adap, int val)
19291ed5349SWolfram Sang {
1938092178fSWolfram Sang gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val);
19491ed5349SWolfram Sang }
19591ed5349SWolfram Sang
i2c_generic_bus_free(struct i2c_adapter * adap)1967ca5f6beSWolfram Sang static int i2c_generic_bus_free(struct i2c_adapter *adap)
1977ca5f6beSWolfram Sang {
1987ca5f6beSWolfram Sang struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
1997ca5f6beSWolfram Sang int ret = -EOPNOTSUPP;
2007ca5f6beSWolfram Sang
2017ca5f6beSWolfram Sang if (bri->get_bus_free)
2027ca5f6beSWolfram Sang ret = bri->get_bus_free(adap);
2037ca5f6beSWolfram Sang else if (bri->get_sda)
2047ca5f6beSWolfram Sang ret = bri->get_sda(adap);
2057ca5f6beSWolfram Sang
2067ca5f6beSWolfram Sang if (ret < 0)
2077ca5f6beSWolfram Sang return ret;
2087ca5f6beSWolfram Sang
2097ca5f6beSWolfram Sang return ret ? 0 : -EBUSY;
2107ca5f6beSWolfram Sang }
2117ca5f6beSWolfram Sang
21291ed5349SWolfram Sang /*
21391ed5349SWolfram Sang * We are generating clock pulses. ndelay() determines durating of clk pulses.
21491ed5349SWolfram Sang * We will generate clock with rate 100 KHz and so duration of both clock levels
21591ed5349SWolfram Sang * is: delay in ns = (10^6 / 100) / 2
21691ed5349SWolfram Sang */
21791ed5349SWolfram Sang #define RECOVERY_NDELAY 5000
21891ed5349SWolfram Sang #define RECOVERY_CLK_CNT 9
21991ed5349SWolfram Sang
i2c_generic_scl_recovery(struct i2c_adapter * adap)220e1eb7d28SPhil Reid int i2c_generic_scl_recovery(struct i2c_adapter *adap)
22191ed5349SWolfram Sang {
22291ed5349SWolfram Sang struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
223cf676908SLinus Torvalds int i = 0, scl = 1, ret = 0;
22491ed5349SWolfram Sang
22591ed5349SWolfram Sang if (bri->prepare_recovery)
22691ed5349SWolfram Sang bri->prepare_recovery(adap);
22775820314SCodrin Ciubotariu if (bri->pinctrl)
22875820314SCodrin Ciubotariu pinctrl_select_state(bri->pinctrl, bri->pins_gpio);
22991ed5349SWolfram Sang
230c4ae05b9SWolfram Sang /*
231c4ae05b9SWolfram Sang * If we can set SDA, we will always create a STOP to ensure additional
232c4ae05b9SWolfram Sang * pulses will do no harm. This is achieved by letting SDA follow SCL
233c4ae05b9SWolfram Sang * half a cycle later. Check the 'incomplete_write_byte' fault injector
234cf8ce8b8SRussell King * for details. Note that we must honour tsu:sto, 4us, but lets use 5us
235cf8ce8b8SRussell King * here for simplicity.
236c4ae05b9SWolfram Sang */
237f7ff75e2SWolfram Sang bri->set_scl(adap, scl);
238cf8ce8b8SRussell King ndelay(RECOVERY_NDELAY);
23972b08fccSWolfram Sang if (bri->set_sda)
240c4ae05b9SWolfram Sang bri->set_sda(adap, scl);
241c4ae05b9SWolfram Sang ndelay(RECOVERY_NDELAY / 2);
24291ed5349SWolfram Sang
24391ed5349SWolfram Sang /*
24491ed5349SWolfram Sang * By this time SCL is high, as we need to give 9 falling-rising edges
24591ed5349SWolfram Sang */
24691ed5349SWolfram Sang while (i++ < RECOVERY_CLK_CNT * 2) {
247f7ff75e2SWolfram Sang if (scl) {
24891ed5349SWolfram Sang /* SCL shouldn't be low here */
24991ed5349SWolfram Sang if (!bri->get_scl(adap)) {
25091ed5349SWolfram Sang dev_err(&adap->dev,
25191ed5349SWolfram Sang "SCL is stuck low, exit recovery\n");
25291ed5349SWolfram Sang ret = -EBUSY;
25391ed5349SWolfram Sang break;
25491ed5349SWolfram Sang }
25591ed5349SWolfram Sang }
25691ed5349SWolfram Sang
257f7ff75e2SWolfram Sang scl = !scl;
258f7ff75e2SWolfram Sang bri->set_scl(adap, scl);
259c4ae05b9SWolfram Sang /* Creating STOP again, see above */
260cf8ce8b8SRussell King if (scl) {
261cf8ce8b8SRussell King /* Honour minimum tsu:sto */
262cf8ce8b8SRussell King ndelay(RECOVERY_NDELAY);
263cf8ce8b8SRussell King } else {
264cf8ce8b8SRussell King /* Honour minimum tf and thd:dat */
265abe41184SWolfram Sang ndelay(RECOVERY_NDELAY / 2);
266cf8ce8b8SRussell King }
267abe41184SWolfram Sang if (bri->set_sda)
268f7ff75e2SWolfram Sang bri->set_sda(adap, scl);
269abe41184SWolfram Sang ndelay(RECOVERY_NDELAY / 2);
2700b71026cSWolfram Sang
271f7ff75e2SWolfram Sang if (scl) {
2727ca5f6beSWolfram Sang ret = i2c_generic_bus_free(adap);
2730b71026cSWolfram Sang if (ret == 0)
2740b71026cSWolfram Sang break;
27591ed5349SWolfram Sang }
27691ed5349SWolfram Sang }
27791ed5349SWolfram Sang
2787ca5f6beSWolfram Sang /* If we can't check bus status, assume recovery worked */
2797ca5f6beSWolfram Sang if (ret == -EOPNOTSUPP)
2807ca5f6beSWolfram Sang ret = 0;
2812806e6adSWolfram Sang
28291ed5349SWolfram Sang if (bri->unprepare_recovery)
28391ed5349SWolfram Sang bri->unprepare_recovery(adap);
28475820314SCodrin Ciubotariu if (bri->pinctrl)
28575820314SCodrin Ciubotariu pinctrl_select_state(bri->pinctrl, bri->pins_default);
28691ed5349SWolfram Sang
28791ed5349SWolfram Sang return ret;
28891ed5349SWolfram Sang }
28991ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery);
29091ed5349SWolfram Sang
i2c_recover_bus(struct i2c_adapter * adap)29191ed5349SWolfram Sang int i2c_recover_bus(struct i2c_adapter *adap)
29291ed5349SWolfram Sang {
29391ed5349SWolfram Sang if (!adap->bus_recovery_info)
294c126f7c3SDmitry Osipenko return -EBUSY;
29591ed5349SWolfram Sang
29691ed5349SWolfram Sang dev_dbg(&adap->dev, "Trying i2c bus recovery\n");
29791ed5349SWolfram Sang return adap->bus_recovery_info->recover_bus(adap);
29891ed5349SWolfram Sang }
29991ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_recover_bus);
30091ed5349SWolfram Sang
i2c_gpio_init_pinctrl_recovery(struct i2c_adapter * adap)30175820314SCodrin Ciubotariu static void i2c_gpio_init_pinctrl_recovery(struct i2c_adapter *adap)
30275820314SCodrin Ciubotariu {
30375820314SCodrin Ciubotariu struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
30475820314SCodrin Ciubotariu struct device *dev = &adap->dev;
30520cb3fceSHanna Hawa struct pinctrl *p = bri->pinctrl ?: dev_pinctrl(dev->parent);
30620cb3fceSHanna Hawa
30720cb3fceSHanna Hawa bri->pinctrl = p;
30875820314SCodrin Ciubotariu
30975820314SCodrin Ciubotariu /*
31075820314SCodrin Ciubotariu * we can't change states without pinctrl, so remove the states if
31175820314SCodrin Ciubotariu * populated
31275820314SCodrin Ciubotariu */
31375820314SCodrin Ciubotariu if (!p) {
31475820314SCodrin Ciubotariu bri->pins_default = NULL;
31575820314SCodrin Ciubotariu bri->pins_gpio = NULL;
31675820314SCodrin Ciubotariu return;
31775820314SCodrin Ciubotariu }
31875820314SCodrin Ciubotariu
31975820314SCodrin Ciubotariu if (!bri->pins_default) {
32075820314SCodrin Ciubotariu bri->pins_default = pinctrl_lookup_state(p,
32175820314SCodrin Ciubotariu PINCTRL_STATE_DEFAULT);
32275820314SCodrin Ciubotariu if (IS_ERR(bri->pins_default)) {
32375820314SCodrin Ciubotariu dev_dbg(dev, PINCTRL_STATE_DEFAULT " state not found for GPIO recovery\n");
32475820314SCodrin Ciubotariu bri->pins_default = NULL;
32575820314SCodrin Ciubotariu }
32675820314SCodrin Ciubotariu }
32775820314SCodrin Ciubotariu if (!bri->pins_gpio) {
32875820314SCodrin Ciubotariu bri->pins_gpio = pinctrl_lookup_state(p, "gpio");
32975820314SCodrin Ciubotariu if (IS_ERR(bri->pins_gpio))
33075820314SCodrin Ciubotariu bri->pins_gpio = pinctrl_lookup_state(p, "recovery");
33175820314SCodrin Ciubotariu
33275820314SCodrin Ciubotariu if (IS_ERR(bri->pins_gpio)) {
33375820314SCodrin Ciubotariu dev_dbg(dev, "no gpio or recovery state found for GPIO recovery\n");
33475820314SCodrin Ciubotariu bri->pins_gpio = NULL;
33575820314SCodrin Ciubotariu }
33675820314SCodrin Ciubotariu }
33775820314SCodrin Ciubotariu
33875820314SCodrin Ciubotariu /* for pinctrl state changes, we need all the information */
33975820314SCodrin Ciubotariu if (bri->pins_default && bri->pins_gpio) {
34075820314SCodrin Ciubotariu dev_info(dev, "using pinctrl states for GPIO recovery");
34175820314SCodrin Ciubotariu } else {
34275820314SCodrin Ciubotariu bri->pinctrl = NULL;
34375820314SCodrin Ciubotariu bri->pins_default = NULL;
34475820314SCodrin Ciubotariu bri->pins_gpio = NULL;
34575820314SCodrin Ciubotariu }
34675820314SCodrin Ciubotariu }
34775820314SCodrin Ciubotariu
i2c_gpio_init_generic_recovery(struct i2c_adapter * adap)34875820314SCodrin Ciubotariu static int i2c_gpio_init_generic_recovery(struct i2c_adapter *adap)
34975820314SCodrin Ciubotariu {
35075820314SCodrin Ciubotariu struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
35175820314SCodrin Ciubotariu struct device *dev = &adap->dev;
35275820314SCodrin Ciubotariu struct gpio_desc *gpiod;
35375820314SCodrin Ciubotariu int ret = 0;
35475820314SCodrin Ciubotariu
35575820314SCodrin Ciubotariu /*
35675820314SCodrin Ciubotariu * don't touch the recovery information if the driver is not using
35775820314SCodrin Ciubotariu * generic SCL recovery
35875820314SCodrin Ciubotariu */
35975820314SCodrin Ciubotariu if (bri->recover_bus && bri->recover_bus != i2c_generic_scl_recovery)
36075820314SCodrin Ciubotariu return 0;
36175820314SCodrin Ciubotariu
36275820314SCodrin Ciubotariu /*
36375820314SCodrin Ciubotariu * pins might be taken as GPIO, so we should inform pinctrl about
36475820314SCodrin Ciubotariu * this and move the state to GPIO
36575820314SCodrin Ciubotariu */
36675820314SCodrin Ciubotariu if (bri->pinctrl)
36775820314SCodrin Ciubotariu pinctrl_select_state(bri->pinctrl, bri->pins_gpio);
36875820314SCodrin Ciubotariu
36975820314SCodrin Ciubotariu /*
37075820314SCodrin Ciubotariu * if there is incomplete or no recovery information, see if generic
37175820314SCodrin Ciubotariu * GPIO recovery is available
37275820314SCodrin Ciubotariu */
37375820314SCodrin Ciubotariu if (!bri->scl_gpiod) {
37475820314SCodrin Ciubotariu gpiod = devm_gpiod_get(dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN);
37575820314SCodrin Ciubotariu if (PTR_ERR(gpiod) == -EPROBE_DEFER) {
37675820314SCodrin Ciubotariu ret = -EPROBE_DEFER;
37775820314SCodrin Ciubotariu goto cleanup_pinctrl_state;
37875820314SCodrin Ciubotariu }
37975820314SCodrin Ciubotariu if (!IS_ERR(gpiod)) {
38075820314SCodrin Ciubotariu bri->scl_gpiod = gpiod;
38175820314SCodrin Ciubotariu bri->recover_bus = i2c_generic_scl_recovery;
38275820314SCodrin Ciubotariu dev_info(dev, "using generic GPIOs for recovery\n");
38375820314SCodrin Ciubotariu }
38475820314SCodrin Ciubotariu }
38575820314SCodrin Ciubotariu
38675820314SCodrin Ciubotariu /* SDA GPIOD line is optional, so we care about DEFER only */
38775820314SCodrin Ciubotariu if (!bri->sda_gpiod) {
38875820314SCodrin Ciubotariu /*
38975820314SCodrin Ciubotariu * We have SCL. Pull SCL low and wait a bit so that SDA glitches
39075820314SCodrin Ciubotariu * have no effect.
39175820314SCodrin Ciubotariu */
39275820314SCodrin Ciubotariu gpiod_direction_output(bri->scl_gpiod, 0);
39375820314SCodrin Ciubotariu udelay(10);
39475820314SCodrin Ciubotariu gpiod = devm_gpiod_get(dev, "sda", GPIOD_IN);
39575820314SCodrin Ciubotariu
39675820314SCodrin Ciubotariu /* Wait a bit in case of a SDA glitch, and then release SCL. */
39775820314SCodrin Ciubotariu udelay(10);
39875820314SCodrin Ciubotariu gpiod_direction_output(bri->scl_gpiod, 1);
39975820314SCodrin Ciubotariu
40075820314SCodrin Ciubotariu if (PTR_ERR(gpiod) == -EPROBE_DEFER) {
40175820314SCodrin Ciubotariu ret = -EPROBE_DEFER;
40275820314SCodrin Ciubotariu goto cleanup_pinctrl_state;
40375820314SCodrin Ciubotariu }
40475820314SCodrin Ciubotariu if (!IS_ERR(gpiod))
40575820314SCodrin Ciubotariu bri->sda_gpiod = gpiod;
40675820314SCodrin Ciubotariu }
40775820314SCodrin Ciubotariu
40875820314SCodrin Ciubotariu cleanup_pinctrl_state:
40975820314SCodrin Ciubotariu /* change the state of the pins back to their default state */
41075820314SCodrin Ciubotariu if (bri->pinctrl)
41175820314SCodrin Ciubotariu pinctrl_select_state(bri->pinctrl, bri->pins_default);
41275820314SCodrin Ciubotariu
41375820314SCodrin Ciubotariu return ret;
41475820314SCodrin Ciubotariu }
41575820314SCodrin Ciubotariu
i2c_gpio_init_recovery(struct i2c_adapter * adap)41675820314SCodrin Ciubotariu static int i2c_gpio_init_recovery(struct i2c_adapter *adap)
41775820314SCodrin Ciubotariu {
41875820314SCodrin Ciubotariu i2c_gpio_init_pinctrl_recovery(adap);
41975820314SCodrin Ciubotariu return i2c_gpio_init_generic_recovery(adap);
42075820314SCodrin Ciubotariu }
42175820314SCodrin Ciubotariu
i2c_init_recovery(struct i2c_adapter * adap)42223a698feSCodrin Ciubotariu static int i2c_init_recovery(struct i2c_adapter *adap)
42391ed5349SWolfram Sang {
42491ed5349SWolfram Sang struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
425cb3c66afSAndy Shevchenko bool is_error_level = true;
426cb3c66afSAndy Shevchenko char *err_str;
42791ed5349SWolfram Sang
42891ed5349SWolfram Sang if (!bri)
42923a698feSCodrin Ciubotariu return 0;
43091ed5349SWolfram Sang
43123a698feSCodrin Ciubotariu if (i2c_gpio_init_recovery(adap) == -EPROBE_DEFER)
43223a698feSCodrin Ciubotariu return -EPROBE_DEFER;
43375820314SCodrin Ciubotariu
43491ed5349SWolfram Sang if (!bri->recover_bus) {
435e409a6a3SWolfram Sang err_str = "no suitable method provided";
436cb3c66afSAndy Shevchenko is_error_level = false;
43791ed5349SWolfram Sang goto err;
43891ed5349SWolfram Sang }
43991ed5349SWolfram Sang
4403991c5c8SPhil Reid if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) {
44191ed5349SWolfram Sang bri->get_scl = get_scl_gpio_value;
44291ed5349SWolfram Sang bri->set_scl = set_scl_gpio_value;
4438092178fSWolfram Sang if (bri->sda_gpiod) {
4443991c5c8SPhil Reid bri->get_sda = get_sda_gpio_value;
4458092178fSWolfram Sang /* FIXME: add proper flag instead of '0' once available */
4468092178fSWolfram Sang if (gpiod_get_direction(bri->sda_gpiod) == 0)
4478092178fSWolfram Sang bri->set_sda = set_sda_gpio_value;
4488092178fSWolfram Sang }
44923a698feSCodrin Ciubotariu } else if (bri->recover_bus == i2c_generic_scl_recovery) {
45091ed5349SWolfram Sang /* Generic SCL recovery */
45191ed5349SWolfram Sang if (!bri->set_scl || !bri->get_scl) {
45291ed5349SWolfram Sang err_str = "no {get|set}_scl() found";
45391ed5349SWolfram Sang goto err;
45491ed5349SWolfram Sang }
455ffc59c49SWolfram Sang if (!bri->set_sda && !bri->get_sda) {
456ffc59c49SWolfram Sang err_str = "either get_sda() or set_sda() needed";
457ffc59c49SWolfram Sang goto err;
458ffc59c49SWolfram Sang }
45991ed5349SWolfram Sang }
46091ed5349SWolfram Sang
46123a698feSCodrin Ciubotariu return 0;
46291ed5349SWolfram Sang err:
463cb3c66afSAndy Shevchenko if (is_error_level)
464cb3c66afSAndy Shevchenko dev_err(&adap->dev, "Not using recovery: %s\n", err_str);
465cb3c66afSAndy Shevchenko else
466cb3c66afSAndy Shevchenko dev_dbg(&adap->dev, "Not using recovery: %s\n", err_str);
46791ed5349SWolfram Sang adap->bus_recovery_info = NULL;
46823a698feSCodrin Ciubotariu
46923a698feSCodrin Ciubotariu return -EINVAL;
47091ed5349SWolfram Sang }
47191ed5349SWolfram Sang
i2c_smbus_host_notify_to_irq(const struct i2c_client * client)47291ed5349SWolfram Sang static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client)
47391ed5349SWolfram Sang {
47491ed5349SWolfram Sang struct i2c_adapter *adap = client->adapter;
47591ed5349SWolfram Sang unsigned int irq;
47691ed5349SWolfram Sang
47791ed5349SWolfram Sang if (!adap->host_notify_domain)
47891ed5349SWolfram Sang return -ENXIO;
47991ed5349SWolfram Sang
48091ed5349SWolfram Sang if (client->flags & I2C_CLIENT_TEN)
48191ed5349SWolfram Sang return -EINVAL;
48291ed5349SWolfram Sang
483b9bb3fdfSCharles Keepax irq = irq_create_mapping(adap->host_notify_domain, client->addr);
48491ed5349SWolfram Sang
48591ed5349SWolfram Sang return irq > 0 ? irq : -ENXIO;
48691ed5349SWolfram Sang }
48791ed5349SWolfram Sang
i2c_device_probe(struct device * dev)48891ed5349SWolfram Sang static int i2c_device_probe(struct device *dev)
48991ed5349SWolfram Sang {
49091ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev);
49191ed5349SWolfram Sang struct i2c_driver *driver;
49279ece9b2SRicardo Ribalda bool do_power_on;
49391ed5349SWolfram Sang int status;
49491ed5349SWolfram Sang
49591ed5349SWolfram Sang if (!client)
49691ed5349SWolfram Sang return 0;
49791ed5349SWolfram Sang
4986e76cb7dSCharles Keepax client->irq = client->init_irq;
4996e76cb7dSCharles Keepax
5000c2a3493SWolfram Sang if (!client->irq) {
50191ed5349SWolfram Sang int irq = -ENOENT;
50291ed5349SWolfram Sang
50391ed5349SWolfram Sang if (client->flags & I2C_CLIENT_HOST_NOTIFY) {
50491ed5349SWolfram Sang dev_dbg(dev, "Using Host Notify IRQ\n");
50572bfcee1SJarkko Nikula /* Keep adapter active when Host Notify is required */
50672bfcee1SJarkko Nikula pm_runtime_get_sync(&client->adapter->dev);
50791ed5349SWolfram Sang irq = i2c_smbus_host_notify_to_irq(client);
50891ed5349SWolfram Sang } else if (dev->of_node) {
50991ed5349SWolfram Sang irq = of_irq_get_byname(dev->of_node, "irq");
51091ed5349SWolfram Sang if (irq == -EINVAL || irq == -ENODATA)
51191ed5349SWolfram Sang irq = of_irq_get(dev->of_node, 0);
51291ed5349SWolfram Sang } else if (ACPI_COMPANION(dev)) {
513b38f2d5dSRaul E Rangel bool wake_capable;
514b38f2d5dSRaul E Rangel
515b38f2d5dSRaul E Rangel irq = i2c_acpi_get_irq(client, &wake_capable);
516b38f2d5dSRaul E Rangel if (irq > 0 && wake_capable)
517b38f2d5dSRaul E Rangel client->flags |= I2C_CLIENT_WAKE;
51891ed5349SWolfram Sang }
5193c3dd56fSAlain Volmat if (irq == -EPROBE_DEFER) {
5203c3dd56fSAlain Volmat status = irq;
5213c3dd56fSAlain Volmat goto put_sync_adapter;
5223c3dd56fSAlain Volmat }
52391ed5349SWolfram Sang
52491ed5349SWolfram Sang if (irq < 0)
52591ed5349SWolfram Sang irq = 0;
52691ed5349SWolfram Sang
52791ed5349SWolfram Sang client->irq = irq;
52891ed5349SWolfram Sang }
52991ed5349SWolfram Sang
5300c2a3493SWolfram Sang driver = to_i2c_driver(dev->driver);
5310c2a3493SWolfram Sang
53291ed5349SWolfram Sang /*
533f4b17a14SJavier Martinez Canillas * An I2C ID table is not mandatory, if and only if, a suitable OF
534f4b17a14SJavier Martinez Canillas * or ACPI ID table is supplied for the probing device.
53591ed5349SWolfram Sang */
53691ed5349SWolfram Sang if (!driver->id_table &&
537e3cb82c6SAndy Shevchenko !acpi_driver_match_device(dev, dev->driver) &&
5383c3dd56fSAlain Volmat !i2c_of_match_device(dev->driver->of_match_table, client)) {
5393c3dd56fSAlain Volmat status = -ENODEV;
5403c3dd56fSAlain Volmat goto put_sync_adapter;
5413c3dd56fSAlain Volmat }
54291ed5349SWolfram Sang
54391ed5349SWolfram Sang if (client->flags & I2C_CLIENT_WAKE) {
5443e99834cSAndy Shevchenko int wakeirq;
54591ed5349SWolfram Sang
54691ed5349SWolfram Sang wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
5473c3dd56fSAlain Volmat if (wakeirq == -EPROBE_DEFER) {
5483c3dd56fSAlain Volmat status = wakeirq;
5493c3dd56fSAlain Volmat goto put_sync_adapter;
5503c3dd56fSAlain Volmat }
55191ed5349SWolfram Sang
55291ed5349SWolfram Sang device_init_wakeup(&client->dev, true);
55391ed5349SWolfram Sang
55491ed5349SWolfram Sang if (wakeirq > 0 && wakeirq != client->irq)
55591ed5349SWolfram Sang status = dev_pm_set_dedicated_wake_irq(dev, wakeirq);
55691ed5349SWolfram Sang else if (client->irq > 0)
55791ed5349SWolfram Sang status = dev_pm_set_wake_irq(dev, client->irq);
55891ed5349SWolfram Sang else
55991ed5349SWolfram Sang status = 0;
56091ed5349SWolfram Sang
56191ed5349SWolfram Sang if (status)
56291ed5349SWolfram Sang dev_warn(&client->dev, "failed to set up wakeup irq\n");
56391ed5349SWolfram Sang }
56491ed5349SWolfram Sang
56591ed5349SWolfram Sang dev_dbg(dev, "probe\n");
56691ed5349SWolfram Sang
56791ed5349SWolfram Sang status = of_clk_set_defaults(dev->of_node, false);
56891ed5349SWolfram Sang if (status < 0)
56991ed5349SWolfram Sang goto err_clear_wakeup_irq;
57091ed5349SWolfram Sang
57179ece9b2SRicardo Ribalda do_power_on = !i2c_acpi_waive_d0_probe(dev);
57279ece9b2SRicardo Ribalda status = dev_pm_domain_attach(&client->dev, do_power_on);
573e6a20b6cSUlf Hansson if (status)
57491ed5349SWolfram Sang goto err_clear_wakeup_irq;
57591ed5349SWolfram Sang
5765b547582SDmitry Torokhov client->devres_group_id = devres_open_group(&client->dev, NULL,
5775b547582SDmitry Torokhov GFP_KERNEL);
5785b547582SDmitry Torokhov if (!client->devres_group_id) {
5795b547582SDmitry Torokhov status = -ENOMEM;
5805b547582SDmitry Torokhov goto err_detach_pm_domain;
5815b547582SDmitry Torokhov }
5825b547582SDmitry Torokhov
58303c835f4SUwe Kleine-König if (driver->probe)
58403c835f4SUwe Kleine-König status = driver->probe(client);
58591ed5349SWolfram Sang else
58691ed5349SWolfram Sang status = -EINVAL;
58791ed5349SWolfram Sang
5885b547582SDmitry Torokhov /*
5895b547582SDmitry Torokhov * Note that we are not closing the devres group opened above so
5905b547582SDmitry Torokhov * even resources that were attached to the device after probe is
5915b547582SDmitry Torokhov * run are released when i2c_device_remove() is executed. This is
5925b547582SDmitry Torokhov * needed as some drivers would allocate additional resources,
5935b547582SDmitry Torokhov * for example when updating firmware.
5945b547582SDmitry Torokhov */
5955b547582SDmitry Torokhov
59691ed5349SWolfram Sang if (status)
5975b547582SDmitry Torokhov goto err_release_driver_resources;
59891ed5349SWolfram Sang
59991ed5349SWolfram Sang return 0;
60091ed5349SWolfram Sang
6015b547582SDmitry Torokhov err_release_driver_resources:
6025b547582SDmitry Torokhov devres_release_group(&client->dev, client->devres_group_id);
60391ed5349SWolfram Sang err_detach_pm_domain:
60479ece9b2SRicardo Ribalda dev_pm_domain_detach(&client->dev, do_power_on);
60591ed5349SWolfram Sang err_clear_wakeup_irq:
60691ed5349SWolfram Sang dev_pm_clear_wake_irq(&client->dev);
60791ed5349SWolfram Sang device_init_wakeup(&client->dev, false);
6083c3dd56fSAlain Volmat put_sync_adapter:
6093c3dd56fSAlain Volmat if (client->flags & I2C_CLIENT_HOST_NOTIFY)
6103c3dd56fSAlain Volmat pm_runtime_put_sync(&client->adapter->dev);
6113c3dd56fSAlain Volmat
61291ed5349SWolfram Sang return status;
61391ed5349SWolfram Sang }
61491ed5349SWolfram Sang
i2c_device_remove(struct device * dev)615fc7a6209SUwe Kleine-König static void i2c_device_remove(struct device *dev)
61691ed5349SWolfram Sang {
6174e970a0aSUwe Kleine-König struct i2c_client *client = to_i2c_client(dev);
61891ed5349SWolfram Sang struct i2c_driver *driver;
61991ed5349SWolfram Sang
62091ed5349SWolfram Sang driver = to_i2c_driver(dev->driver);
62191ed5349SWolfram Sang if (driver->remove) {
62291ed5349SWolfram Sang dev_dbg(dev, "remove\n");
62371637c62SUwe Kleine-König
624ed5c2f5fSUwe Kleine-König driver->remove(client);
62591ed5349SWolfram Sang }
62691ed5349SWolfram Sang
6275b547582SDmitry Torokhov devres_release_group(&client->dev, client->devres_group_id);
6285b547582SDmitry Torokhov
62979ece9b2SRicardo Ribalda dev_pm_domain_detach(&client->dev, true);
63091ed5349SWolfram Sang
63191ed5349SWolfram Sang dev_pm_clear_wake_irq(&client->dev);
63291ed5349SWolfram Sang device_init_wakeup(&client->dev, false);
63391ed5349SWolfram Sang
6346e76cb7dSCharles Keepax client->irq = 0;
63572bfcee1SJarkko Nikula if (client->flags & I2C_CLIENT_HOST_NOTIFY)
63672bfcee1SJarkko Nikula pm_runtime_put(&client->adapter->dev);
63791ed5349SWolfram Sang }
63891ed5349SWolfram Sang
i2c_device_shutdown(struct device * dev)63991ed5349SWolfram Sang static void i2c_device_shutdown(struct device *dev)
64091ed5349SWolfram Sang {
64191ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev);
64291ed5349SWolfram Sang struct i2c_driver *driver;
64391ed5349SWolfram Sang
64491ed5349SWolfram Sang if (!client || !dev->driver)
64591ed5349SWolfram Sang return;
64691ed5349SWolfram Sang driver = to_i2c_driver(dev->driver);
64791ed5349SWolfram Sang if (driver->shutdown)
64891ed5349SWolfram Sang driver->shutdown(client);
649b64210f2SDmitry Torokhov else if (client->irq > 0)
650b64210f2SDmitry Torokhov disable_irq(client->irq);
65191ed5349SWolfram Sang }
65291ed5349SWolfram Sang
i2c_client_dev_release(struct device * dev)65391ed5349SWolfram Sang static void i2c_client_dev_release(struct device *dev)
65491ed5349SWolfram Sang {
65591ed5349SWolfram Sang kfree(to_i2c_client(dev));
65691ed5349SWolfram Sang }
65791ed5349SWolfram Sang
65891ed5349SWolfram Sang static ssize_t
name_show(struct device * dev,struct device_attribute * attr,char * buf)65954a19fd4SGeert Uytterhoeven name_show(struct device *dev, struct device_attribute *attr, char *buf)
66091ed5349SWolfram Sang {
66191ed5349SWolfram Sang return sprintf(buf, "%s\n", dev->type == &i2c_client_type ?
66291ed5349SWolfram Sang to_i2c_client(dev)->name : to_i2c_adapter(dev)->name);
66391ed5349SWolfram Sang }
66454a19fd4SGeert Uytterhoeven static DEVICE_ATTR_RO(name);
66591ed5349SWolfram Sang
66691ed5349SWolfram Sang static ssize_t
modalias_show(struct device * dev,struct device_attribute * attr,char * buf)66754a19fd4SGeert Uytterhoeven modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
66891ed5349SWolfram Sang {
66991ed5349SWolfram Sang struct i2c_client *client = to_i2c_client(dev);
67091ed5349SWolfram Sang int len;
67191ed5349SWolfram Sang
672af503716SJavier Martinez Canillas len = of_device_modalias(dev, buf, PAGE_SIZE);
673af503716SJavier Martinez Canillas if (len != -ENODEV)
674af503716SJavier Martinez Canillas return len;
675af503716SJavier Martinez Canillas
67691ed5349SWolfram Sang len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
67791ed5349SWolfram Sang if (len != -ENODEV)
67891ed5349SWolfram Sang return len;
67991ed5349SWolfram Sang
68091ed5349SWolfram Sang return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
68191ed5349SWolfram Sang }
68254a19fd4SGeert Uytterhoeven static DEVICE_ATTR_RO(modalias);
68391ed5349SWolfram Sang
68491ed5349SWolfram Sang static struct attribute *i2c_dev_attrs[] = {
68591ed5349SWolfram Sang &dev_attr_name.attr,
68691ed5349SWolfram Sang /* modalias helps coldplug: modprobe $(cat .../modalias) */
68791ed5349SWolfram Sang &dev_attr_modalias.attr,
68891ed5349SWolfram Sang NULL
68991ed5349SWolfram Sang };
69091ed5349SWolfram Sang ATTRIBUTE_GROUPS(i2c_dev);
69191ed5349SWolfram Sang
69291ed5349SWolfram Sang struct bus_type i2c_bus_type = {
69391ed5349SWolfram Sang .name = "i2c",
69491ed5349SWolfram Sang .match = i2c_device_match,
69591ed5349SWolfram Sang .probe = i2c_device_probe,
69691ed5349SWolfram Sang .remove = i2c_device_remove,
69791ed5349SWolfram Sang .shutdown = i2c_device_shutdown,
69891ed5349SWolfram Sang };
69991ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_bus_type);
70091ed5349SWolfram Sang
70191ed5349SWolfram Sang struct device_type i2c_client_type = {
70291ed5349SWolfram Sang .groups = i2c_dev_groups,
70391ed5349SWolfram Sang .uevent = i2c_device_uevent,
70491ed5349SWolfram Sang .release = i2c_client_dev_release,
70591ed5349SWolfram Sang };
70691ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_client_type);
70791ed5349SWolfram Sang
70891ed5349SWolfram Sang
70991ed5349SWolfram Sang /**
71091ed5349SWolfram Sang * i2c_verify_client - return parameter as i2c_client, or NULL
71191ed5349SWolfram Sang * @dev: device, probably from some driver model iterator
71291ed5349SWolfram Sang *
71391ed5349SWolfram Sang * When traversing the driver model tree, perhaps using driver model
71491ed5349SWolfram Sang * iterators like @device_for_each_child(), you can't assume very much
71591ed5349SWolfram Sang * about the nodes you find. Use this function to avoid oopses caused
71691ed5349SWolfram Sang * by wrongly treating some non-I2C device as an i2c_client.
71791ed5349SWolfram Sang */
i2c_verify_client(struct device * dev)71891ed5349SWolfram Sang struct i2c_client *i2c_verify_client(struct device *dev)
71991ed5349SWolfram Sang {
72091ed5349SWolfram Sang return (dev->type == &i2c_client_type)
72191ed5349SWolfram Sang ? to_i2c_client(dev)
72291ed5349SWolfram Sang : NULL;
72391ed5349SWolfram Sang }
72491ed5349SWolfram Sang EXPORT_SYMBOL(i2c_verify_client);
72591ed5349SWolfram Sang
72691ed5349SWolfram Sang
72791ed5349SWolfram Sang /* Return a unique address which takes the flags of the client into account */
i2c_encode_flags_to_addr(struct i2c_client * client)72891ed5349SWolfram Sang static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client)
72991ed5349SWolfram Sang {
73091ed5349SWolfram Sang unsigned short addr = client->addr;
73191ed5349SWolfram Sang
73291ed5349SWolfram Sang /* For some client flags, add an arbitrary offset to avoid collisions */
73391ed5349SWolfram Sang if (client->flags & I2C_CLIENT_TEN)
73491ed5349SWolfram Sang addr |= I2C_ADDR_OFFSET_TEN_BIT;
73591ed5349SWolfram Sang
73691ed5349SWolfram Sang if (client->flags & I2C_CLIENT_SLAVE)
73791ed5349SWolfram Sang addr |= I2C_ADDR_OFFSET_SLAVE;
73891ed5349SWolfram Sang
73991ed5349SWolfram Sang return addr;
74091ed5349SWolfram Sang }
74191ed5349SWolfram Sang
74291ed5349SWolfram Sang /* This is a permissive address validity check, I2C address map constraints
74391ed5349SWolfram Sang * are purposely not enforced, except for the general call address. */
i2c_check_addr_validity(unsigned int addr,unsigned short flags)744398432edSWolfram Sang static int i2c_check_addr_validity(unsigned int addr, unsigned short flags)
74591ed5349SWolfram Sang {
74691ed5349SWolfram Sang if (flags & I2C_CLIENT_TEN) {
74791ed5349SWolfram Sang /* 10-bit address, all values are valid */
74891ed5349SWolfram Sang if (addr > 0x3ff)
74991ed5349SWolfram Sang return -EINVAL;
75091ed5349SWolfram Sang } else {
75191ed5349SWolfram Sang /* 7-bit address, reject the general call address */
75291ed5349SWolfram Sang if (addr == 0x00 || addr > 0x7f)
75391ed5349SWolfram Sang return -EINVAL;
75491ed5349SWolfram Sang }
75591ed5349SWolfram Sang return 0;
75691ed5349SWolfram Sang }
75791ed5349SWolfram Sang
75891ed5349SWolfram Sang /* And this is a strict address validity check, used when probing. If a
75991ed5349SWolfram Sang * device uses a reserved address, then it shouldn't be probed. 7-bit
76091ed5349SWolfram Sang * addressing is assumed, 10-bit address devices are rare and should be
76191ed5349SWolfram Sang * explicitly enumerated. */
i2c_check_7bit_addr_validity_strict(unsigned short addr)762e4991ecdSWolfram Sang int i2c_check_7bit_addr_validity_strict(unsigned short addr)
76391ed5349SWolfram Sang {
76491ed5349SWolfram Sang /*
76591ed5349SWolfram Sang * Reserved addresses per I2C specification:
76691ed5349SWolfram Sang * 0x00 General call address / START byte
76791ed5349SWolfram Sang * 0x01 CBUS address
76891ed5349SWolfram Sang * 0x02 Reserved for different bus format
76991ed5349SWolfram Sang * 0x03 Reserved for future purposes
77091ed5349SWolfram Sang * 0x04-0x07 Hs-mode master code
77191ed5349SWolfram Sang * 0x78-0x7b 10-bit slave addressing
77291ed5349SWolfram Sang * 0x7c-0x7f Reserved for future purposes
77391ed5349SWolfram Sang */
77491ed5349SWolfram Sang if (addr < 0x08 || addr > 0x77)
77591ed5349SWolfram Sang return -EINVAL;
77691ed5349SWolfram Sang return 0;
77791ed5349SWolfram Sang }
77891ed5349SWolfram Sang
__i2c_check_addr_busy(struct device * dev,void * addrp)77991ed5349SWolfram Sang static int __i2c_check_addr_busy(struct device *dev, void *addrp)
78091ed5349SWolfram Sang {
78191ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev);
78291ed5349SWolfram Sang int addr = *(int *)addrp;
78391ed5349SWolfram Sang
78491ed5349SWolfram Sang if (client && i2c_encode_flags_to_addr(client) == addr)
78591ed5349SWolfram Sang return -EBUSY;
78691ed5349SWolfram Sang return 0;
78791ed5349SWolfram Sang }
78891ed5349SWolfram Sang
78991ed5349SWolfram Sang /* walk up mux tree */
i2c_check_mux_parents(struct i2c_adapter * adapter,int addr)79091ed5349SWolfram Sang static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr)
79191ed5349SWolfram Sang {
79291ed5349SWolfram Sang struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
79391ed5349SWolfram Sang int result;
79491ed5349SWolfram Sang
79591ed5349SWolfram Sang result = device_for_each_child(&adapter->dev, &addr,
79691ed5349SWolfram Sang __i2c_check_addr_busy);
79791ed5349SWolfram Sang
79891ed5349SWolfram Sang if (!result && parent)
79991ed5349SWolfram Sang result = i2c_check_mux_parents(parent, addr);
80091ed5349SWolfram Sang
80191ed5349SWolfram Sang return result;
80291ed5349SWolfram Sang }
80391ed5349SWolfram Sang
80491ed5349SWolfram Sang /* recurse down mux tree */
i2c_check_mux_children(struct device * dev,void * addrp)80591ed5349SWolfram Sang static int i2c_check_mux_children(struct device *dev, void *addrp)
80691ed5349SWolfram Sang {
80791ed5349SWolfram Sang int result;
80891ed5349SWolfram Sang
80991ed5349SWolfram Sang if (dev->type == &i2c_adapter_type)
81091ed5349SWolfram Sang result = device_for_each_child(dev, addrp,
81191ed5349SWolfram Sang i2c_check_mux_children);
81291ed5349SWolfram Sang else
81391ed5349SWolfram Sang result = __i2c_check_addr_busy(dev, addrp);
81491ed5349SWolfram Sang
81591ed5349SWolfram Sang return result;
81691ed5349SWolfram Sang }
81791ed5349SWolfram Sang
i2c_check_addr_busy(struct i2c_adapter * adapter,int addr)81891ed5349SWolfram Sang static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
81991ed5349SWolfram Sang {
82091ed5349SWolfram Sang struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
82191ed5349SWolfram Sang int result = 0;
82291ed5349SWolfram Sang
82391ed5349SWolfram Sang if (parent)
82491ed5349SWolfram Sang result = i2c_check_mux_parents(parent, addr);
82591ed5349SWolfram Sang
82691ed5349SWolfram Sang if (!result)
82791ed5349SWolfram Sang result = device_for_each_child(&adapter->dev, &addr,
82891ed5349SWolfram Sang i2c_check_mux_children);
82991ed5349SWolfram Sang
83091ed5349SWolfram Sang return result;
83191ed5349SWolfram Sang }
83291ed5349SWolfram Sang
83391ed5349SWolfram Sang /**
83491ed5349SWolfram Sang * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment
83591ed5349SWolfram Sang * @adapter: Target I2C bus segment
83691ed5349SWolfram Sang * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
83791ed5349SWolfram Sang * locks only this branch in the adapter tree
83891ed5349SWolfram Sang */
i2c_adapter_lock_bus(struct i2c_adapter * adapter,unsigned int flags)83991ed5349SWolfram Sang static void i2c_adapter_lock_bus(struct i2c_adapter *adapter,
84091ed5349SWolfram Sang unsigned int flags)
84191ed5349SWolfram Sang {
8427b94ea50SPeter Rosin rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter));
84391ed5349SWolfram Sang }
84491ed5349SWolfram Sang
84591ed5349SWolfram Sang /**
84691ed5349SWolfram Sang * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment
84791ed5349SWolfram Sang * @adapter: Target I2C bus segment
84891ed5349SWolfram Sang * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT
84991ed5349SWolfram Sang * trylocks only this branch in the adapter tree
85091ed5349SWolfram Sang */
i2c_adapter_trylock_bus(struct i2c_adapter * adapter,unsigned int flags)85191ed5349SWolfram Sang static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter,
85291ed5349SWolfram Sang unsigned int flags)
85391ed5349SWolfram Sang {
85491ed5349SWolfram Sang return rt_mutex_trylock(&adapter->bus_lock);
85591ed5349SWolfram Sang }
85691ed5349SWolfram Sang
85791ed5349SWolfram Sang /**
85891ed5349SWolfram Sang * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment
85991ed5349SWolfram Sang * @adapter: Target I2C bus segment
86091ed5349SWolfram Sang * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
86191ed5349SWolfram Sang * unlocks only this branch in the adapter tree
86291ed5349SWolfram Sang */
i2c_adapter_unlock_bus(struct i2c_adapter * adapter,unsigned int flags)86391ed5349SWolfram Sang static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter,
86491ed5349SWolfram Sang unsigned int flags)
86591ed5349SWolfram Sang {
86691ed5349SWolfram Sang rt_mutex_unlock(&adapter->bus_lock);
86791ed5349SWolfram Sang }
86891ed5349SWolfram Sang
i2c_dev_set_name(struct i2c_adapter * adap,struct i2c_client * client,struct i2c_board_info const * info)86991ed5349SWolfram Sang static void i2c_dev_set_name(struct i2c_adapter *adap,
870728fe6ceSHans de Goede struct i2c_client *client,
871728fe6ceSHans de Goede struct i2c_board_info const *info)
87291ed5349SWolfram Sang {
87391ed5349SWolfram Sang struct acpi_device *adev = ACPI_COMPANION(&client->dev);
87491ed5349SWolfram Sang
875728fe6ceSHans de Goede if (info && info->dev_name) {
876728fe6ceSHans de Goede dev_set_name(&client->dev, "i2c-%s", info->dev_name);
877728fe6ceSHans de Goede return;
878728fe6ceSHans de Goede }
879728fe6ceSHans de Goede
88091ed5349SWolfram Sang if (adev) {
88191ed5349SWolfram Sang dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev));
88291ed5349SWolfram Sang return;
88391ed5349SWolfram Sang }
88491ed5349SWolfram Sang
88591ed5349SWolfram Sang dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
88691ed5349SWolfram Sang i2c_encode_flags_to_addr(client));
88791ed5349SWolfram Sang }
88891ed5349SWolfram Sang
i2c_dev_irq_from_resources(const struct resource * resources,unsigned int num_resources)8891d7534b6SCharles Keepax int i2c_dev_irq_from_resources(const struct resource *resources,
89091ed5349SWolfram Sang unsigned int num_resources)
89191ed5349SWolfram Sang {
89291ed5349SWolfram Sang struct irq_data *irqd;
89391ed5349SWolfram Sang int i;
89491ed5349SWolfram Sang
89591ed5349SWolfram Sang for (i = 0; i < num_resources; i++) {
89691ed5349SWolfram Sang const struct resource *r = &resources[i];
89791ed5349SWolfram Sang
89891ed5349SWolfram Sang if (resource_type(r) != IORESOURCE_IRQ)
89991ed5349SWolfram Sang continue;
90091ed5349SWolfram Sang
90191ed5349SWolfram Sang if (r->flags & IORESOURCE_BITS) {
90291ed5349SWolfram Sang irqd = irq_get_irq_data(r->start);
90391ed5349SWolfram Sang if (!irqd)
90491ed5349SWolfram Sang break;
90591ed5349SWolfram Sang
90691ed5349SWolfram Sang irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
90791ed5349SWolfram Sang }
90891ed5349SWolfram Sang
90991ed5349SWolfram Sang return r->start;
91091ed5349SWolfram Sang }
91191ed5349SWolfram Sang
91291ed5349SWolfram Sang return 0;
91391ed5349SWolfram Sang }
91491ed5349SWolfram Sang
91591ed5349SWolfram Sang /**
9167159dbdaSHeiner Kallweit * i2c_new_client_device - instantiate an i2c device
91791ed5349SWolfram Sang * @adap: the adapter managing the device
91891ed5349SWolfram Sang * @info: describes one I2C device; bus_num is ignored
91991ed5349SWolfram Sang * Context: can sleep
92091ed5349SWolfram Sang *
92191ed5349SWolfram Sang * Create an i2c device. Binding is handled through driver model
92291ed5349SWolfram Sang * probe()/remove() methods. A driver may be bound to this device when we
92391ed5349SWolfram Sang * return from this function, or any later moment (e.g. maybe hotplugging will
92491ed5349SWolfram Sang * load the driver module). This call is not appropriate for use by mainboard
92591ed5349SWolfram Sang * initialization logic, which usually runs during an arch_initcall() long
92691ed5349SWolfram Sang * before any i2c_adapter could exist.
92791ed5349SWolfram Sang *
92891ed5349SWolfram Sang * This returns the new i2c client, which may be saved for later use with
9297159dbdaSHeiner Kallweit * i2c_unregister_device(); or an ERR_PTR to describe the error.
93091ed5349SWolfram Sang */
931550113d4SWolfram Sang struct i2c_client *
i2c_new_client_device(struct i2c_adapter * adap,struct i2c_board_info const * info)9327159dbdaSHeiner Kallweit i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
93391ed5349SWolfram Sang {
93491ed5349SWolfram Sang struct i2c_client *client;
935bd62916bSWolfram Sang bool need_put = false;
93691ed5349SWolfram Sang int status;
93791ed5349SWolfram Sang
93891ed5349SWolfram Sang client = kzalloc(sizeof *client, GFP_KERNEL);
93991ed5349SWolfram Sang if (!client)
9407159dbdaSHeiner Kallweit return ERR_PTR(-ENOMEM);
94191ed5349SWolfram Sang
94291ed5349SWolfram Sang client->adapter = adap;
94391ed5349SWolfram Sang
94491ed5349SWolfram Sang client->dev.platform_data = info->platform_data;
94591ed5349SWolfram Sang client->flags = info->flags;
94691ed5349SWolfram Sang client->addr = info->addr;
94791ed5349SWolfram Sang
94893b6604cSJim Broadus client->init_irq = info->irq;
94993b6604cSJim Broadus if (!client->init_irq)
95093b6604cSJim Broadus client->init_irq = i2c_dev_irq_from_resources(info->resources,
95191ed5349SWolfram Sang info->num_resources);
95291ed5349SWolfram Sang
9530b0221d9SWolfram Sang strscpy(client->name, info->type, sizeof(client->name));
95491ed5349SWolfram Sang
95591ed5349SWolfram Sang status = i2c_check_addr_validity(client->addr, client->flags);
95691ed5349SWolfram Sang if (status) {
95791ed5349SWolfram Sang dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n",
95891ed5349SWolfram Sang client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr);
95991ed5349SWolfram Sang goto out_err_silent;
96091ed5349SWolfram Sang }
96191ed5349SWolfram Sang
96291ed5349SWolfram Sang /* Check for address business */
96391ed5349SWolfram Sang status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client));
96491ed5349SWolfram Sang if (status)
96591ed5349SWolfram Sang goto out_err;
96691ed5349SWolfram Sang
96791ed5349SWolfram Sang client->dev.parent = &client->adapter->dev;
96891ed5349SWolfram Sang client->dev.bus = &i2c_bus_type;
96991ed5349SWolfram Sang client->dev.type = &i2c_client_type;
97004782265SBoris Brezillon client->dev.of_node = of_node_get(info->of_node);
97191ed5349SWolfram Sang client->dev.fwnode = info->fwnode;
97291ed5349SWolfram Sang
973172d9319SDerek Basehore device_enable_async_suspend(&client->dev);
97491ed5349SWolfram Sang
975714638e0SHeikki Krogerus if (info->swnode) {
976714638e0SHeikki Krogerus status = device_add_software_node(&client->dev, info->swnode);
97791ed5349SWolfram Sang if (status) {
97891ed5349SWolfram Sang dev_err(&adap->dev,
979714638e0SHeikki Krogerus "Failed to add software node to client %s: %d\n",
98091ed5349SWolfram Sang client->name, status);
98104782265SBoris Brezillon goto out_err_put_of_node;
98291ed5349SWolfram Sang }
98391ed5349SWolfram Sang }
98491ed5349SWolfram Sang
985bd62916bSWolfram Sang i2c_dev_set_name(adap, client, info);
98691ed5349SWolfram Sang status = device_register(&client->dev);
98791ed5349SWolfram Sang if (status)
988714638e0SHeikki Krogerus goto out_remove_swnode;
98991ed5349SWolfram Sang
99091ed5349SWolfram Sang dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
99191ed5349SWolfram Sang client->name, dev_name(&client->dev));
99291ed5349SWolfram Sang
99391ed5349SWolfram Sang return client;
99491ed5349SWolfram Sang
995714638e0SHeikki Krogerus out_remove_swnode:
996714638e0SHeikki Krogerus device_remove_software_node(&client->dev);
997bd62916bSWolfram Sang need_put = true;
99804782265SBoris Brezillon out_err_put_of_node:
99904782265SBoris Brezillon of_node_put(info->of_node);
100091ed5349SWolfram Sang out_err:
100191ed5349SWolfram Sang dev_err(&adap->dev,
100291ed5349SWolfram Sang "Failed to register i2c client %s at 0x%02x (%d)\n",
100391ed5349SWolfram Sang client->name, client->addr, status);
100491ed5349SWolfram Sang out_err_silent:
1005bd62916bSWolfram Sang if (need_put)
1006bd62916bSWolfram Sang put_device(&client->dev);
1007bd62916bSWolfram Sang else
100891ed5349SWolfram Sang kfree(client);
10097159dbdaSHeiner Kallweit return ERR_PTR(status);
10107159dbdaSHeiner Kallweit }
10117159dbdaSHeiner Kallweit EXPORT_SYMBOL_GPL(i2c_new_client_device);
10127159dbdaSHeiner Kallweit
10137159dbdaSHeiner Kallweit /**
101487e07437SWolfram Sang * i2c_unregister_device - reverse effect of i2c_new_*_device()
101587e07437SWolfram Sang * @client: value returned from i2c_new_*_device()
101691ed5349SWolfram Sang * Context: can sleep
101791ed5349SWolfram Sang */
i2c_unregister_device(struct i2c_client * client)101891ed5349SWolfram Sang void i2c_unregister_device(struct i2c_client *client)
101991ed5349SWolfram Sang {
1020689f5358SWolfram Sang if (IS_ERR_OR_NULL(client))
10217b43dd19SAndy Shevchenko return;
1022e0638fa4SLixin Wang
1023e0638fa4SLixin Wang if (client->dev.of_node) {
102491ed5349SWolfram Sang of_node_clear_flag(client->dev.of_node, OF_POPULATED);
1025e0638fa4SLixin Wang of_node_put(client->dev.of_node);
1026e0638fa4SLixin Wang }
1027e0638fa4SLixin Wang
102891ed5349SWolfram Sang if (ACPI_COMPANION(&client->dev))
102991ed5349SWolfram Sang acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev));
1030714638e0SHeikki Krogerus device_remove_software_node(&client->dev);
103191ed5349SWolfram Sang device_unregister(&client->dev);
103291ed5349SWolfram Sang }
103391ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_unregister_device);
103491ed5349SWolfram Sang
1035373c612dSRussell King (Oracle) /**
1036373c612dSRussell King (Oracle) * i2c_find_device_by_fwnode() - find an i2c_client for the fwnode
1037373c612dSRussell King (Oracle) * @fwnode: &struct fwnode_handle corresponding to the &struct i2c_client
1038373c612dSRussell King (Oracle) *
1039373c612dSRussell King (Oracle) * Look up and return the &struct i2c_client corresponding to the @fwnode.
1040373c612dSRussell King (Oracle) * If no client can be found, or @fwnode is NULL, this returns NULL.
1041373c612dSRussell King (Oracle) *
1042373c612dSRussell King (Oracle) * The user must call put_device(&client->dev) once done with the i2c client.
1043373c612dSRussell King (Oracle) */
i2c_find_device_by_fwnode(struct fwnode_handle * fwnode)1044373c612dSRussell King (Oracle) struct i2c_client *i2c_find_device_by_fwnode(struct fwnode_handle *fwnode)
1045373c612dSRussell King (Oracle) {
1046373c612dSRussell King (Oracle) struct i2c_client *client;
1047373c612dSRussell King (Oracle) struct device *dev;
1048373c612dSRussell King (Oracle)
1049373c612dSRussell King (Oracle) if (!fwnode)
1050373c612dSRussell King (Oracle) return NULL;
1051373c612dSRussell King (Oracle)
1052373c612dSRussell King (Oracle) dev = bus_find_device_by_fwnode(&i2c_bus_type, fwnode);
1053373c612dSRussell King (Oracle) if (!dev)
1054373c612dSRussell King (Oracle) return NULL;
1055373c612dSRussell King (Oracle)
1056373c612dSRussell King (Oracle) client = i2c_verify_client(dev);
1057373c612dSRussell King (Oracle) if (!client)
1058373c612dSRussell King (Oracle) put_device(dev);
1059373c612dSRussell King (Oracle)
1060373c612dSRussell King (Oracle) return client;
1061373c612dSRussell King (Oracle) }
1062373c612dSRussell King (Oracle) EXPORT_SYMBOL(i2c_find_device_by_fwnode);
1063373c612dSRussell King (Oracle)
106491ed5349SWolfram Sang
106591ed5349SWolfram Sang static const struct i2c_device_id dummy_id[] = {
106691ed5349SWolfram Sang { "dummy", 0 },
106791ed5349SWolfram Sang { },
106891ed5349SWolfram Sang };
106991ed5349SWolfram Sang
dummy_probe(struct i2c_client * client)1070a00f6d37SStephen Kitt static int dummy_probe(struct i2c_client *client)
107191ed5349SWolfram Sang {
107291ed5349SWolfram Sang return 0;
107391ed5349SWolfram Sang }
107491ed5349SWolfram Sang
107591ed5349SWolfram Sang static struct i2c_driver dummy_driver = {
107691ed5349SWolfram Sang .driver.name = "dummy",
1077834a9dc4SUwe Kleine-König .probe = dummy_probe,
107891ed5349SWolfram Sang .id_table = dummy_id,
107991ed5349SWolfram Sang };
108091ed5349SWolfram Sang
108191ed5349SWolfram Sang /**
10827159dbdaSHeiner Kallweit * i2c_new_dummy_device - return a new i2c device bound to a dummy driver
108391ed5349SWolfram Sang * @adapter: the adapter managing the device
108491ed5349SWolfram Sang * @address: seven bit address to be used
108591ed5349SWolfram Sang * Context: can sleep
108691ed5349SWolfram Sang *
108791ed5349SWolfram Sang * This returns an I2C client bound to the "dummy" driver, intended for use
108891ed5349SWolfram Sang * with devices that consume multiple addresses. Examples of such chips
108991ed5349SWolfram Sang * include various EEPROMS (like 24c04 and 24c08 models).
109091ed5349SWolfram Sang *
109191ed5349SWolfram Sang * These dummy devices have two main uses. First, most I2C and SMBus calls
109291ed5349SWolfram Sang * except i2c_transfer() need a client handle; the dummy will be that handle.
109391ed5349SWolfram Sang * And second, this prevents the specified address from being bound to a
109491ed5349SWolfram Sang * different driver.
109591ed5349SWolfram Sang *
109691ed5349SWolfram Sang * This returns the new i2c client, which should be saved for later use with
10977159dbdaSHeiner Kallweit * i2c_unregister_device(); or an ERR_PTR to describe the error.
109891ed5349SWolfram Sang */
i2c_new_dummy_device(struct i2c_adapter * adapter,u16 address)1099550113d4SWolfram Sang struct i2c_client *i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address)
110091ed5349SWolfram Sang {
110191ed5349SWolfram Sang struct i2c_board_info info = {
110291ed5349SWolfram Sang I2C_BOARD_INFO("dummy", address),
110391ed5349SWolfram Sang };
110491ed5349SWolfram Sang
11057159dbdaSHeiner Kallweit return i2c_new_client_device(adapter, &info);
11067159dbdaSHeiner Kallweit }
11077159dbdaSHeiner Kallweit EXPORT_SYMBOL_GPL(i2c_new_dummy_device);
11087159dbdaSHeiner Kallweit
devm_i2c_release_dummy(void * client)1109bb7f086bSYicong Yang static void devm_i2c_release_dummy(void *client)
1110b8f5fe3bSHeiner Kallweit {
1111bb7f086bSYicong Yang i2c_unregister_device(client);
1112b8f5fe3bSHeiner Kallweit }
1113b8f5fe3bSHeiner Kallweit
1114b8f5fe3bSHeiner Kallweit /**
1115b8f5fe3bSHeiner Kallweit * devm_i2c_new_dummy_device - return a new i2c device bound to a dummy driver
1116b8f5fe3bSHeiner Kallweit * @dev: device the managed resource is bound to
1117b8f5fe3bSHeiner Kallweit * @adapter: the adapter managing the device
1118b8f5fe3bSHeiner Kallweit * @address: seven bit address to be used
1119b8f5fe3bSHeiner Kallweit * Context: can sleep
1120b8f5fe3bSHeiner Kallweit *
1121b8f5fe3bSHeiner Kallweit * This is the device-managed version of @i2c_new_dummy_device. It returns the
1122b8f5fe3bSHeiner Kallweit * new i2c client or an ERR_PTR in case of an error.
1123b8f5fe3bSHeiner Kallweit */
devm_i2c_new_dummy_device(struct device * dev,struct i2c_adapter * adapter,u16 address)1124b8f5fe3bSHeiner Kallweit struct i2c_client *devm_i2c_new_dummy_device(struct device *dev,
1125b8f5fe3bSHeiner Kallweit struct i2c_adapter *adapter,
1126b8f5fe3bSHeiner Kallweit u16 address)
1127b8f5fe3bSHeiner Kallweit {
1128b8f5fe3bSHeiner Kallweit struct i2c_client *client;
1129bb7f086bSYicong Yang int ret;
1130b8f5fe3bSHeiner Kallweit
1131b8f5fe3bSHeiner Kallweit client = i2c_new_dummy_device(adapter, address);
1132bb7f086bSYicong Yang if (IS_ERR(client))
1133bb7f086bSYicong Yang return client;
1134bb7f086bSYicong Yang
1135bb7f086bSYicong Yang ret = devm_add_action_or_reset(dev, devm_i2c_release_dummy, client);
1136bb7f086bSYicong Yang if (ret)
1137bb7f086bSYicong Yang return ERR_PTR(ret);
1138b8f5fe3bSHeiner Kallweit
1139b8f5fe3bSHeiner Kallweit return client;
1140b8f5fe3bSHeiner Kallweit }
1141b8f5fe3bSHeiner Kallweit EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device);
1142b8f5fe3bSHeiner Kallweit
114391ed5349SWolfram Sang /**
1144af80559bSWolfram Sang * i2c_new_ancillary_device - Helper to get the instantiated secondary address
114591ed5349SWolfram Sang * and create the associated device
114691ed5349SWolfram Sang * @client: Handle to the primary client
114791ed5349SWolfram Sang * @name: Handle to specify which secondary address to get
114891ed5349SWolfram Sang * @default_addr: Used as a fallback if no secondary address was specified
114991ed5349SWolfram Sang * Context: can sleep
115091ed5349SWolfram Sang *
115191ed5349SWolfram Sang * I2C clients can be composed of multiple I2C slaves bound together in a single
115291ed5349SWolfram Sang * component. The I2C client driver then binds to the master I2C slave and needs
115391ed5349SWolfram Sang * to create I2C dummy clients to communicate with all the other slaves.
115491ed5349SWolfram Sang *
115591ed5349SWolfram Sang * This function creates and returns an I2C dummy client whose I2C address is
115691ed5349SWolfram Sang * retrieved from the platform firmware based on the given slave name. If no
115791ed5349SWolfram Sang * address is specified by the firmware default_addr is used.
115891ed5349SWolfram Sang *
115991ed5349SWolfram Sang * On DT-based platforms the address is retrieved from the "reg" property entry
116091ed5349SWolfram Sang * cell whose "reg-names" value matches the slave name.
116191ed5349SWolfram Sang *
116291ed5349SWolfram Sang * This returns the new i2c client, which should be saved for later use with
1163af80559bSWolfram Sang * i2c_unregister_device(); or an ERR_PTR to describe the error.
116491ed5349SWolfram Sang */
i2c_new_ancillary_device(struct i2c_client * client,const char * name,u16 default_addr)1165af80559bSWolfram Sang struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client,
116691ed5349SWolfram Sang const char *name,
116791ed5349SWolfram Sang u16 default_addr)
116891ed5349SWolfram Sang {
116991ed5349SWolfram Sang struct device_node *np = client->dev.of_node;
117091ed5349SWolfram Sang u32 addr = default_addr;
117191ed5349SWolfram Sang int i;
117291ed5349SWolfram Sang
117391ed5349SWolfram Sang if (np) {
117491ed5349SWolfram Sang i = of_property_match_string(np, "reg-names", name);
117591ed5349SWolfram Sang if (i >= 0)
117691ed5349SWolfram Sang of_property_read_u32_index(np, "reg", i, &addr);
117791ed5349SWolfram Sang }
117891ed5349SWolfram Sang
117991ed5349SWolfram Sang dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr);
1180af80559bSWolfram Sang return i2c_new_dummy_device(client->adapter, addr);
118191ed5349SWolfram Sang }
1182af80559bSWolfram Sang EXPORT_SYMBOL_GPL(i2c_new_ancillary_device);
118391ed5349SWolfram Sang
118491ed5349SWolfram Sang /* ------------------------------------------------------------------------- */
118591ed5349SWolfram Sang
118691ed5349SWolfram Sang /* I2C bus adapters -- one roots each I2C or SMBUS segment */
118791ed5349SWolfram Sang
i2c_adapter_dev_release(struct device * dev)118891ed5349SWolfram Sang static void i2c_adapter_dev_release(struct device *dev)
118991ed5349SWolfram Sang {
119091ed5349SWolfram Sang struct i2c_adapter *adap = to_i2c_adapter(dev);
119191ed5349SWolfram Sang complete(&adap->dev_released);
119291ed5349SWolfram Sang }
119391ed5349SWolfram Sang
i2c_adapter_depth(struct i2c_adapter * adapter)119491ed5349SWolfram Sang unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
119591ed5349SWolfram Sang {
119691ed5349SWolfram Sang unsigned int depth = 0;
119791ed5349SWolfram Sang
119891ed5349SWolfram Sang while ((adapter = i2c_parent_is_i2c_adapter(adapter)))
119991ed5349SWolfram Sang depth++;
120091ed5349SWolfram Sang
120191ed5349SWolfram Sang WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES,
120291ed5349SWolfram Sang "adapter depth exceeds lockdep subclass limit\n");
120391ed5349SWolfram Sang
120491ed5349SWolfram Sang return depth;
120591ed5349SWolfram Sang }
120691ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_adapter_depth);
120791ed5349SWolfram Sang
120891ed5349SWolfram Sang /*
120991ed5349SWolfram Sang * Let users instantiate I2C devices through sysfs. This can be used when
121091ed5349SWolfram Sang * platform initialization code doesn't contain the proper data for
121191ed5349SWolfram Sang * whatever reason. Also useful for drivers that do device detection and
121291ed5349SWolfram Sang * detection fails, either because the device uses an unexpected address,
121391ed5349SWolfram Sang * or this is a compatible device with different ID register values.
121491ed5349SWolfram Sang *
121591ed5349SWolfram Sang * Parameter checking may look overzealous, but we really don't want
121691ed5349SWolfram Sang * the user to provide incorrect parameters.
121791ed5349SWolfram Sang */
121891ed5349SWolfram Sang static ssize_t
new_device_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)121954a19fd4SGeert Uytterhoeven new_device_store(struct device *dev, struct device_attribute *attr,
122091ed5349SWolfram Sang const char *buf, size_t count)
122191ed5349SWolfram Sang {
122291ed5349SWolfram Sang struct i2c_adapter *adap = to_i2c_adapter(dev);
122391ed5349SWolfram Sang struct i2c_board_info info;
122491ed5349SWolfram Sang struct i2c_client *client;
122591ed5349SWolfram Sang char *blank, end;
122691ed5349SWolfram Sang int res;
122791ed5349SWolfram Sang
122891ed5349SWolfram Sang memset(&info, 0, sizeof(struct i2c_board_info));
122991ed5349SWolfram Sang
123091ed5349SWolfram Sang blank = strchr(buf, ' ');
123191ed5349SWolfram Sang if (!blank) {
123291ed5349SWolfram Sang dev_err(dev, "%s: Missing parameters\n", "new_device");
123391ed5349SWolfram Sang return -EINVAL;
123491ed5349SWolfram Sang }
123591ed5349SWolfram Sang if (blank - buf > I2C_NAME_SIZE - 1) {
123691ed5349SWolfram Sang dev_err(dev, "%s: Invalid device name\n", "new_device");
123791ed5349SWolfram Sang return -EINVAL;
123891ed5349SWolfram Sang }
123991ed5349SWolfram Sang memcpy(info.type, buf, blank - buf);
124091ed5349SWolfram Sang
124191ed5349SWolfram Sang /* Parse remaining parameters, reject extra parameters */
124291ed5349SWolfram Sang res = sscanf(++blank, "%hi%c", &info.addr, &end);
124391ed5349SWolfram Sang if (res < 1) {
124491ed5349SWolfram Sang dev_err(dev, "%s: Can't parse I2C address\n", "new_device");
124591ed5349SWolfram Sang return -EINVAL;
124691ed5349SWolfram Sang }
124791ed5349SWolfram Sang if (res > 1 && end != '\n') {
124891ed5349SWolfram Sang dev_err(dev, "%s: Extra parameters\n", "new_device");
124991ed5349SWolfram Sang return -EINVAL;
125091ed5349SWolfram Sang }
125191ed5349SWolfram Sang
125291ed5349SWolfram Sang if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) {
125391ed5349SWolfram Sang info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT;
125491ed5349SWolfram Sang info.flags |= I2C_CLIENT_TEN;
125591ed5349SWolfram Sang }
125691ed5349SWolfram Sang
125791ed5349SWolfram Sang if (info.addr & I2C_ADDR_OFFSET_SLAVE) {
125891ed5349SWolfram Sang info.addr &= ~I2C_ADDR_OFFSET_SLAVE;
125991ed5349SWolfram Sang info.flags |= I2C_CLIENT_SLAVE;
126091ed5349SWolfram Sang }
126191ed5349SWolfram Sang
12627159dbdaSHeiner Kallweit client = i2c_new_client_device(adap, &info);
12637159dbdaSHeiner Kallweit if (IS_ERR(client))
12647159dbdaSHeiner Kallweit return PTR_ERR(client);
126591ed5349SWolfram Sang
126691ed5349SWolfram Sang /* Keep track of the added device */
126791ed5349SWolfram Sang mutex_lock(&adap->userspace_clients_lock);
126891ed5349SWolfram Sang list_add_tail(&client->detected, &adap->userspace_clients);
126991ed5349SWolfram Sang mutex_unlock(&adap->userspace_clients_lock);
127091ed5349SWolfram Sang dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",
127191ed5349SWolfram Sang info.type, info.addr);
127291ed5349SWolfram Sang
127391ed5349SWolfram Sang return count;
127491ed5349SWolfram Sang }
127554a19fd4SGeert Uytterhoeven static DEVICE_ATTR_WO(new_device);
127691ed5349SWolfram Sang
127791ed5349SWolfram Sang /*
127891ed5349SWolfram Sang * And of course let the users delete the devices they instantiated, if
127991ed5349SWolfram Sang * they got it wrong. This interface can only be used to delete devices
128091ed5349SWolfram Sang * instantiated by i2c_sysfs_new_device above. This guarantees that we
128191ed5349SWolfram Sang * don't delete devices to which some kernel code still has references.
128291ed5349SWolfram Sang *
128391ed5349SWolfram Sang * Parameter checking may look overzealous, but we really don't want
128491ed5349SWolfram Sang * the user to delete the wrong device.
128591ed5349SWolfram Sang */
128691ed5349SWolfram Sang static ssize_t
delete_device_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)128754a19fd4SGeert Uytterhoeven delete_device_store(struct device *dev, struct device_attribute *attr,
128891ed5349SWolfram Sang const char *buf, size_t count)
128991ed5349SWolfram Sang {
129091ed5349SWolfram Sang struct i2c_adapter *adap = to_i2c_adapter(dev);
129191ed5349SWolfram Sang struct i2c_client *client, *next;
129291ed5349SWolfram Sang unsigned short addr;
129391ed5349SWolfram Sang char end;
129491ed5349SWolfram Sang int res;
129591ed5349SWolfram Sang
129691ed5349SWolfram Sang /* Parse parameters, reject extra parameters */
129791ed5349SWolfram Sang res = sscanf(buf, "%hi%c", &addr, &end);
129891ed5349SWolfram Sang if (res < 1) {
129991ed5349SWolfram Sang dev_err(dev, "%s: Can't parse I2C address\n", "delete_device");
130091ed5349SWolfram Sang return -EINVAL;
130191ed5349SWolfram Sang }
130291ed5349SWolfram Sang if (res > 1 && end != '\n') {
130391ed5349SWolfram Sang dev_err(dev, "%s: Extra parameters\n", "delete_device");
130491ed5349SWolfram Sang return -EINVAL;
130591ed5349SWolfram Sang }
130691ed5349SWolfram Sang
130791ed5349SWolfram Sang /* Make sure the device was added through sysfs */
130891ed5349SWolfram Sang res = -ENOENT;
130991ed5349SWolfram Sang mutex_lock_nested(&adap->userspace_clients_lock,
131091ed5349SWolfram Sang i2c_adapter_depth(adap));
131191ed5349SWolfram Sang list_for_each_entry_safe(client, next, &adap->userspace_clients,
131291ed5349SWolfram Sang detected) {
131391ed5349SWolfram Sang if (i2c_encode_flags_to_addr(client) == addr) {
131491ed5349SWolfram Sang dev_info(dev, "%s: Deleting device %s at 0x%02hx\n",
131591ed5349SWolfram Sang "delete_device", client->name, client->addr);
131691ed5349SWolfram Sang
131791ed5349SWolfram Sang list_del(&client->detected);
131891ed5349SWolfram Sang i2c_unregister_device(client);
131991ed5349SWolfram Sang res = count;
132091ed5349SWolfram Sang break;
132191ed5349SWolfram Sang }
132291ed5349SWolfram Sang }
132391ed5349SWolfram Sang mutex_unlock(&adap->userspace_clients_lock);
132491ed5349SWolfram Sang
132591ed5349SWolfram Sang if (res < 0)
132691ed5349SWolfram Sang dev_err(dev, "%s: Can't find device in list\n",
132791ed5349SWolfram Sang "delete_device");
132891ed5349SWolfram Sang return res;
132991ed5349SWolfram Sang }
133091ed5349SWolfram Sang static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL,
133154a19fd4SGeert Uytterhoeven delete_device_store);
133291ed5349SWolfram Sang
133391ed5349SWolfram Sang static struct attribute *i2c_adapter_attrs[] = {
133491ed5349SWolfram Sang &dev_attr_name.attr,
133591ed5349SWolfram Sang &dev_attr_new_device.attr,
133691ed5349SWolfram Sang &dev_attr_delete_device.attr,
133791ed5349SWolfram Sang NULL
133891ed5349SWolfram Sang };
133991ed5349SWolfram Sang ATTRIBUTE_GROUPS(i2c_adapter);
134091ed5349SWolfram Sang
134191ed5349SWolfram Sang struct device_type i2c_adapter_type = {
134291ed5349SWolfram Sang .groups = i2c_adapter_groups,
134391ed5349SWolfram Sang .release = i2c_adapter_dev_release,
134491ed5349SWolfram Sang };
134591ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_adapter_type);
134691ed5349SWolfram Sang
134791ed5349SWolfram Sang /**
134891ed5349SWolfram Sang * i2c_verify_adapter - return parameter as i2c_adapter or NULL
134991ed5349SWolfram Sang * @dev: device, probably from some driver model iterator
135091ed5349SWolfram Sang *
135191ed5349SWolfram Sang * When traversing the driver model tree, perhaps using driver model
135291ed5349SWolfram Sang * iterators like @device_for_each_child(), you can't assume very much
135391ed5349SWolfram Sang * about the nodes you find. Use this function to avoid oopses caused
135491ed5349SWolfram Sang * by wrongly treating some non-I2C device as an i2c_adapter.
135591ed5349SWolfram Sang */
i2c_verify_adapter(struct device * dev)135691ed5349SWolfram Sang struct i2c_adapter *i2c_verify_adapter(struct device *dev)
135791ed5349SWolfram Sang {
135891ed5349SWolfram Sang return (dev->type == &i2c_adapter_type)
135991ed5349SWolfram Sang ? to_i2c_adapter(dev)
136091ed5349SWolfram Sang : NULL;
136191ed5349SWolfram Sang }
136291ed5349SWolfram Sang EXPORT_SYMBOL(i2c_verify_adapter);
136391ed5349SWolfram Sang
136491ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT
136591ed5349SWolfram Sang static struct class_compat *i2c_adapter_compat_class;
136691ed5349SWolfram Sang #endif
136791ed5349SWolfram Sang
i2c_scan_static_board_info(struct i2c_adapter * adapter)136891ed5349SWolfram Sang static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
136991ed5349SWolfram Sang {
137091ed5349SWolfram Sang struct i2c_devinfo *devinfo;
137191ed5349SWolfram Sang
137291ed5349SWolfram Sang down_read(&__i2c_board_lock);
137391ed5349SWolfram Sang list_for_each_entry(devinfo, &__i2c_board_list, list) {
137487e07437SWolfram Sang if (devinfo->busnum == adapter->nr &&
137587e07437SWolfram Sang IS_ERR(i2c_new_client_device(adapter, &devinfo->board_info)))
137691ed5349SWolfram Sang dev_err(&adapter->dev,
137791ed5349SWolfram Sang "Can't create device at 0x%02x\n",
137891ed5349SWolfram Sang devinfo->board_info.addr);
137991ed5349SWolfram Sang }
138091ed5349SWolfram Sang up_read(&__i2c_board_lock);
138191ed5349SWolfram Sang }
138291ed5349SWolfram Sang
i2c_do_add_adapter(struct i2c_driver * driver,struct i2c_adapter * adap)138391ed5349SWolfram Sang static int i2c_do_add_adapter(struct i2c_driver *driver,
138491ed5349SWolfram Sang struct i2c_adapter *adap)
138591ed5349SWolfram Sang {
138691ed5349SWolfram Sang /* Detect supported devices on that bus, and instantiate them */
138791ed5349SWolfram Sang i2c_detect(adap, driver);
138891ed5349SWolfram Sang
138991ed5349SWolfram Sang return 0;
139091ed5349SWolfram Sang }
139191ed5349SWolfram Sang
__process_new_adapter(struct device_driver * d,void * data)139291ed5349SWolfram Sang static int __process_new_adapter(struct device_driver *d, void *data)
139391ed5349SWolfram Sang {
139491ed5349SWolfram Sang return i2c_do_add_adapter(to_i2c_driver(d), data);
139591ed5349SWolfram Sang }
139691ed5349SWolfram Sang
139791ed5349SWolfram Sang static const struct i2c_lock_operations i2c_adapter_lock_ops = {
139891ed5349SWolfram Sang .lock_bus = i2c_adapter_lock_bus,
139991ed5349SWolfram Sang .trylock_bus = i2c_adapter_trylock_bus,
140091ed5349SWolfram Sang .unlock_bus = i2c_adapter_unlock_bus,
140191ed5349SWolfram Sang };
140291ed5349SWolfram Sang
140391ed5349SWolfram Sang /*
140491ed5349SWolfram Sang * For a non-mux adapter, the lock_select operation locks the chain of
140591ed5349SWolfram Sang * adapters upwards, returning the root. If there's a mux above this adapter
140691ed5349SWolfram Sang * somehow, it should also get locked and the desired channel selected.
140791ed5349SWolfram Sang */
i2c_adapter_lock_select(struct i2c_adapter * adapter)140891ed5349SWolfram Sang static struct i2c_adapter *i2c_adapter_lock_select(struct i2c_adapter *adapter)
140991ed5349SWolfram Sang {
141091ed5349SWolfram Sang struct i2c_adapter *ret = adapter;
141191ed5349SWolfram Sang struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
141291ed5349SWolfram Sang
141391ed5349SWolfram Sang if (parent) {
141491ed5349SWolfram Sang ret = parent->mux_root_ops->lock_select(parent);
141591ed5349SWolfram Sang if (IS_ERR(ret))
141691ed5349SWolfram Sang return ret;
141791ed5349SWolfram Sang }
141891ed5349SWolfram Sang
141991ed5349SWolfram Sang adapter->lock_ops->lock_bus(adapter, I2C_LOCK_ROOT_ADAPTER);
142091ed5349SWolfram Sang return ret;
142191ed5349SWolfram Sang }
142291ed5349SWolfram Sang
i2c_adapter_unlock_deselect(struct i2c_adapter * adapter)142391ed5349SWolfram Sang static void i2c_adapter_unlock_deselect(struct i2c_adapter *adapter)
142491ed5349SWolfram Sang {
142591ed5349SWolfram Sang struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
142691ed5349SWolfram Sang
142791ed5349SWolfram Sang adapter->lock_ops->unlock_bus(adapter, I2C_LOCK_ROOT_ADAPTER);
142891ed5349SWolfram Sang
142991ed5349SWolfram Sang if (parent)
143091ed5349SWolfram Sang parent->mux_root_ops->unlock_deselect(parent);
143191ed5349SWolfram Sang }
143291ed5349SWolfram Sang
143391ed5349SWolfram Sang static const struct i2c_mux_root_operations i2c_adapter_mux_root_ops = {
143491ed5349SWolfram Sang .lock_select = i2c_adapter_lock_select,
143591ed5349SWolfram Sang .unlock_deselect = i2c_adapter_unlock_deselect,
143691ed5349SWolfram Sang };
143791ed5349SWolfram Sang
i2c_host_notify_irq_teardown(struct i2c_adapter * adap)14388682dc12SWolfram Sang static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap)
143991ed5349SWolfram Sang {
144091ed5349SWolfram Sang struct irq_domain *domain = adap->host_notify_domain;
144191ed5349SWolfram Sang irq_hw_number_t hwirq;
144291ed5349SWolfram Sang
144391ed5349SWolfram Sang if (!domain)
144491ed5349SWolfram Sang return;
144591ed5349SWolfram Sang
144691ed5349SWolfram Sang for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++)
144791ed5349SWolfram Sang irq_dispose_mapping(irq_find_mapping(domain, hwirq));
144891ed5349SWolfram Sang
144991ed5349SWolfram Sang irq_domain_remove(domain);
145091ed5349SWolfram Sang adap->host_notify_domain = NULL;
145191ed5349SWolfram Sang }
145291ed5349SWolfram Sang
i2c_host_notify_irq_map(struct irq_domain * h,unsigned int virq,irq_hw_number_t hw_irq_num)145391ed5349SWolfram Sang static int i2c_host_notify_irq_map(struct irq_domain *h,
145491ed5349SWolfram Sang unsigned int virq,
145591ed5349SWolfram Sang irq_hw_number_t hw_irq_num)
145691ed5349SWolfram Sang {
145791ed5349SWolfram Sang irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
145891ed5349SWolfram Sang
145991ed5349SWolfram Sang return 0;
146091ed5349SWolfram Sang }
146191ed5349SWolfram Sang
146291ed5349SWolfram Sang static const struct irq_domain_ops i2c_host_notify_irq_ops = {
146391ed5349SWolfram Sang .map = i2c_host_notify_irq_map,
146491ed5349SWolfram Sang };
146591ed5349SWolfram Sang
i2c_setup_host_notify_irq_domain(struct i2c_adapter * adap)146691ed5349SWolfram Sang static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap)
146791ed5349SWolfram Sang {
146891ed5349SWolfram Sang struct irq_domain *domain;
146991ed5349SWolfram Sang
147068ea1b2cSSebastian Andrzej Siewior if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY))
147191ed5349SWolfram Sang return 0;
147291ed5349SWolfram Sang
147391ed5349SWolfram Sang domain = irq_domain_create_linear(adap->dev.parent->fwnode,
147491ed5349SWolfram Sang I2C_ADDR_7BITS_COUNT,
147591ed5349SWolfram Sang &i2c_host_notify_irq_ops, adap);
147691ed5349SWolfram Sang if (!domain)
147791ed5349SWolfram Sang return -ENOMEM;
147891ed5349SWolfram Sang
147991ed5349SWolfram Sang adap->host_notify_domain = domain;
148091ed5349SWolfram Sang
148191ed5349SWolfram Sang return 0;
148291ed5349SWolfram Sang }
148391ed5349SWolfram Sang
148491ed5349SWolfram Sang /**
148591ed5349SWolfram Sang * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct
148691ed5349SWolfram Sang * I2C client.
148791ed5349SWolfram Sang * @adap: the adapter
148891ed5349SWolfram Sang * @addr: the I2C address of the notifying device
148991ed5349SWolfram Sang * Context: can't sleep
149091ed5349SWolfram Sang *
149191ed5349SWolfram Sang * Helper function to be called from an I2C bus driver's interrupt
149291ed5349SWolfram Sang * handler. It will schedule the Host Notify IRQ.
149391ed5349SWolfram Sang */
i2c_handle_smbus_host_notify(struct i2c_adapter * adap,unsigned short addr)149491ed5349SWolfram Sang int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr)
149591ed5349SWolfram Sang {
149691ed5349SWolfram Sang int irq;
149791ed5349SWolfram Sang
14989ac6cb5fSWolfram Sang if (!adap)
149991ed5349SWolfram Sang return -EINVAL;
150091ed5349SWolfram Sang
150191ed5349SWolfram Sang irq = irq_find_mapping(adap->host_notify_domain, addr);
150291ed5349SWolfram Sang if (irq <= 0)
150391ed5349SWolfram Sang return -ENXIO;
150491ed5349SWolfram Sang
150591ed5349SWolfram Sang generic_handle_irq_safe(irq);
150691ed5349SWolfram Sang
150791ed5349SWolfram Sang return 0;
150891ed5349SWolfram Sang }
150991ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify);
151091ed5349SWolfram Sang
i2c_register_adapter(struct i2c_adapter * adap)151191ed5349SWolfram Sang static int i2c_register_adapter(struct i2c_adapter *adap)
151291ed5349SWolfram Sang {
151391ed5349SWolfram Sang int res = -EINVAL;
151491ed5349SWolfram Sang
151591ed5349SWolfram Sang /* Can't register until after driver model init */
151691ed5349SWolfram Sang if (WARN_ON(!is_registered)) {
151791ed5349SWolfram Sang res = -EAGAIN;
151891ed5349SWolfram Sang goto out_list;
151991ed5349SWolfram Sang }
152091ed5349SWolfram Sang
152191ed5349SWolfram Sang /* Sanity checks */
152291ed5349SWolfram Sang if (WARN(!adap->name[0], "i2c adapter has no name"))
152391ed5349SWolfram Sang goto out_list;
152491ed5349SWolfram Sang
1525a263a840SAkhil R if (!adap->algo) {
1526f8756c67SPhil Reid pr_err("adapter '%s': no algo supplied!\n", adap->name);
1527f8756c67SPhil Reid goto out_list;
1528f8756c67SPhil Reid }
1529d320ec7aSRajat Jain
153091ed5349SWolfram Sang if (!adap->lock_ops)
153191ed5349SWolfram Sang adap->lock_ops = &i2c_adapter_lock_ops;
153291ed5349SWolfram Sang
153391ed5349SWolfram Sang if (!adap->mux_root_ops)
153423a698feSCodrin Ciubotariu adap->mux_root_ops = &i2c_adapter_mux_root_ops;
153523a698feSCodrin Ciubotariu
153623a698feSCodrin Ciubotariu adap->locked_flags = 0;
153723a698feSCodrin Ciubotariu rt_mutex_init(&adap->bus_lock);
153823a698feSCodrin Ciubotariu rt_mutex_init(&adap->mux_lock);
153923a698feSCodrin Ciubotariu mutex_init(&adap->userspace_clients_lock);
154091ed5349SWolfram Sang INIT_LIST_HEAD(&adap->userspace_clients);
154191ed5349SWolfram Sang
154291ed5349SWolfram Sang /* Set default timeout to 1 second if not already set */
154391ed5349SWolfram Sang if (adap->timeout == 0)
154491ed5349SWolfram Sang adap->timeout = HZ;
154591ed5349SWolfram Sang
154691ed5349SWolfram Sang /* register soft irqs for Host Notify */
154791ed5349SWolfram Sang res = i2c_setup_host_notify_irq_domain(adap);
154891ed5349SWolfram Sang if (res) {
154991ed5349SWolfram Sang pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n",
155091ed5349SWolfram Sang adap->name, res);
155121653a41SHans de Goede goto out_list;
155291ed5349SWolfram Sang }
155391ed5349SWolfram Sang
155491ed5349SWolfram Sang dev_set_name(&adap->dev, "i2c-%d", adap->nr);
155591ed5349SWolfram Sang adap->dev.bus = &i2c_bus_type;
155691ed5349SWolfram Sang adap->dev.type = &i2c_adapter_type;
155791ed5349SWolfram Sang res = device_register(&adap->dev);
155891ed5349SWolfram Sang if (res) {
155991ed5349SWolfram Sang pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
156091ed5349SWolfram Sang goto out_list;
156191ed5349SWolfram Sang }
156291ed5349SWolfram Sang
1563f8756c67SPhil Reid res = i2c_setup_smbus_alert(adap);
1564f8756c67SPhil Reid if (res)
1565f8756c67SPhil Reid goto out_reg;
1566f8756c67SPhil Reid
156791ed5349SWolfram Sang device_enable_async_suspend(&adap->dev);
156891ed5349SWolfram Sang pm_runtime_no_callbacks(&adap->dev);
156991ed5349SWolfram Sang pm_suspend_ignore_children(&adap->dev, true);
157091ed5349SWolfram Sang pm_runtime_enable(&adap->dev);
157191ed5349SWolfram Sang
157291ed5349SWolfram Sang res = i2c_init_recovery(adap);
157391ed5349SWolfram Sang if (res == -EPROBE_DEFER)
157491ed5349SWolfram Sang goto out_reg;
157591ed5349SWolfram Sang
157691ed5349SWolfram Sang dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
157791ed5349SWolfram Sang
157891ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT
157991ed5349SWolfram Sang res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev,
158091ed5349SWolfram Sang adap->dev.parent);
158191ed5349SWolfram Sang if (res)
158291ed5349SWolfram Sang dev_warn(&adap->dev,
158391ed5349SWolfram Sang "Failed to create compatibility class link\n");
158491ed5349SWolfram Sang #endif
158591ed5349SWolfram Sang
158691ed5349SWolfram Sang /* create pre-declared device nodes */
158791ed5349SWolfram Sang of_i2c_register_devices(adap);
158891ed5349SWolfram Sang i2c_acpi_install_space_handler(adap);
158991ed5349SWolfram Sang i2c_acpi_register_devices(adap);
159091ed5349SWolfram Sang
159191ed5349SWolfram Sang if (adap->nr < __i2c_first_dynamic_bus_num)
159291ed5349SWolfram Sang i2c_scan_static_board_info(adap);
159391ed5349SWolfram Sang
159491ed5349SWolfram Sang /* Notify drivers */
159591ed5349SWolfram Sang mutex_lock(&core_lock);
159691ed5349SWolfram Sang bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter);
159791ed5349SWolfram Sang mutex_unlock(&core_lock);
159891ed5349SWolfram Sang
159991ed5349SWolfram Sang return 0;
160091ed5349SWolfram Sang
160191ed5349SWolfram Sang out_reg:
160291ed5349SWolfram Sang init_completion(&adap->dev_released);
160391ed5349SWolfram Sang device_unregister(&adap->dev);
160491ed5349SWolfram Sang wait_for_completion(&adap->dev_released);
160591ed5349SWolfram Sang out_list:
160691ed5349SWolfram Sang mutex_lock(&core_lock);
160791ed5349SWolfram Sang idr_remove(&i2c_adapter_idr, adap->nr);
160891ed5349SWolfram Sang mutex_unlock(&core_lock);
160991ed5349SWolfram Sang return res;
161091ed5349SWolfram Sang }
161191ed5349SWolfram Sang
161291ed5349SWolfram Sang /**
161391ed5349SWolfram Sang * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1
161491ed5349SWolfram Sang * @adap: the adapter to register (with adap->nr initialized)
161591ed5349SWolfram Sang * Context: can sleep
161691ed5349SWolfram Sang *
161791ed5349SWolfram Sang * See i2c_add_numbered_adapter() for details.
161891ed5349SWolfram Sang */
__i2c_add_numbered_adapter(struct i2c_adapter * adap)161991ed5349SWolfram Sang static int __i2c_add_numbered_adapter(struct i2c_adapter *adap)
162091ed5349SWolfram Sang {
162191ed5349SWolfram Sang int id;
162291ed5349SWolfram Sang
162391ed5349SWolfram Sang mutex_lock(&core_lock);
162491ed5349SWolfram Sang id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL);
162591ed5349SWolfram Sang mutex_unlock(&core_lock);
162691ed5349SWolfram Sang if (WARN(id < 0, "couldn't get idr"))
162791ed5349SWolfram Sang return id == -ENOSPC ? -EBUSY : id;
162891ed5349SWolfram Sang
162991ed5349SWolfram Sang return i2c_register_adapter(adap);
163091ed5349SWolfram Sang }
163191ed5349SWolfram Sang
163291ed5349SWolfram Sang /**
163391ed5349SWolfram Sang * i2c_add_adapter - declare i2c adapter, use dynamic bus number
163491ed5349SWolfram Sang * @adapter: the adapter to add
163591ed5349SWolfram Sang * Context: can sleep
163691ed5349SWolfram Sang *
163791ed5349SWolfram Sang * This routine is used to declare an I2C adapter when its bus number
163891ed5349SWolfram Sang * doesn't matter or when its bus number is specified by an dt alias.
163991ed5349SWolfram Sang * Examples of bases when the bus number doesn't matter: I2C adapters
164091ed5349SWolfram Sang * dynamically added by USB links or PCI plugin cards.
164191ed5349SWolfram Sang *
164291ed5349SWolfram Sang * When this returns zero, a new bus number was allocated and stored
164391ed5349SWolfram Sang * in adap->nr, and the specified adapter became available for clients.
164491ed5349SWolfram Sang * Otherwise, a negative errno value is returned.
164591ed5349SWolfram Sang */
i2c_add_adapter(struct i2c_adapter * adapter)164691ed5349SWolfram Sang int i2c_add_adapter(struct i2c_adapter *adapter)
164791ed5349SWolfram Sang {
164891ed5349SWolfram Sang struct device *dev = &adapter->dev;
164991ed5349SWolfram Sang int id;
165091ed5349SWolfram Sang
165191ed5349SWolfram Sang if (dev->of_node) {
165291ed5349SWolfram Sang id = of_alias_get_id(dev->of_node, "i2c");
165391ed5349SWolfram Sang if (id >= 0) {
165491ed5349SWolfram Sang adapter->nr = id;
165591ed5349SWolfram Sang return __i2c_add_numbered_adapter(adapter);
165691ed5349SWolfram Sang }
165791ed5349SWolfram Sang }
165891ed5349SWolfram Sang
165991ed5349SWolfram Sang mutex_lock(&core_lock);
166091ed5349SWolfram Sang id = idr_alloc(&i2c_adapter_idr, adapter,
166191ed5349SWolfram Sang __i2c_first_dynamic_bus_num, 0, GFP_KERNEL);
166291ed5349SWolfram Sang mutex_unlock(&core_lock);
166391ed5349SWolfram Sang if (WARN(id < 0, "couldn't get idr"))
166491ed5349SWolfram Sang return id;
166591ed5349SWolfram Sang
166691ed5349SWolfram Sang adapter->nr = id;
166791ed5349SWolfram Sang
166891ed5349SWolfram Sang return i2c_register_adapter(adapter);
166991ed5349SWolfram Sang }
167091ed5349SWolfram Sang EXPORT_SYMBOL(i2c_add_adapter);
167191ed5349SWolfram Sang
167291ed5349SWolfram Sang /**
167391ed5349SWolfram Sang * i2c_add_numbered_adapter - declare i2c adapter, use static bus number
167491ed5349SWolfram Sang * @adap: the adapter to register (with adap->nr initialized)
167591ed5349SWolfram Sang * Context: can sleep
167691ed5349SWolfram Sang *
167791ed5349SWolfram Sang * This routine is used to declare an I2C adapter when its bus number
167891ed5349SWolfram Sang * matters. For example, use it for I2C adapters from system-on-chip CPUs,
167991ed5349SWolfram Sang * or otherwise built in to the system's mainboard, and where i2c_board_info
168091ed5349SWolfram Sang * is used to properly configure I2C devices.
168191ed5349SWolfram Sang *
168291ed5349SWolfram Sang * If the requested bus number is set to -1, then this function will behave
168391ed5349SWolfram Sang * identically to i2c_add_adapter, and will dynamically assign a bus number.
168491ed5349SWolfram Sang *
168591ed5349SWolfram Sang * If no devices have pre-been declared for this bus, then be sure to
168691ed5349SWolfram Sang * register the adapter before any dynamically allocated ones. Otherwise
168791ed5349SWolfram Sang * the required bus ID may not be available.
168891ed5349SWolfram Sang *
168991ed5349SWolfram Sang * When this returns zero, the specified adapter became available for
169091ed5349SWolfram Sang * clients using the bus number provided in adap->nr. Also, the table
169191ed5349SWolfram Sang * of I2C devices pre-declared using i2c_register_board_info() is scanned,
169291ed5349SWolfram Sang * and the appropriate driver model device nodes are created. Otherwise, a
169391ed5349SWolfram Sang * negative errno value is returned.
169491ed5349SWolfram Sang */
i2c_add_numbered_adapter(struct i2c_adapter * adap)169591ed5349SWolfram Sang int i2c_add_numbered_adapter(struct i2c_adapter *adap)
169691ed5349SWolfram Sang {
169791ed5349SWolfram Sang if (adap->nr == -1) /* -1 means dynamically assign bus id */
169891ed5349SWolfram Sang return i2c_add_adapter(adap);
169991ed5349SWolfram Sang
170091ed5349SWolfram Sang return __i2c_add_numbered_adapter(adap);
170191ed5349SWolfram Sang }
170291ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
170391ed5349SWolfram Sang
i2c_do_del_adapter(struct i2c_driver * driver,struct i2c_adapter * adapter)170491ed5349SWolfram Sang static void i2c_do_del_adapter(struct i2c_driver *driver,
170591ed5349SWolfram Sang struct i2c_adapter *adapter)
170691ed5349SWolfram Sang {
170791ed5349SWolfram Sang struct i2c_client *client, *_n;
170891ed5349SWolfram Sang
170991ed5349SWolfram Sang /* Remove the devices we created ourselves as the result of hardware
171091ed5349SWolfram Sang * probing (using a driver's detect method) */
171191ed5349SWolfram Sang list_for_each_entry_safe(client, _n, &driver->clients, detected) {
171291ed5349SWolfram Sang if (client->adapter == adapter) {
171391ed5349SWolfram Sang dev_dbg(&adapter->dev, "Removing %s at 0x%x\n",
171491ed5349SWolfram Sang client->name, client->addr);
171591ed5349SWolfram Sang list_del(&client->detected);
171691ed5349SWolfram Sang i2c_unregister_device(client);
171791ed5349SWolfram Sang }
171891ed5349SWolfram Sang }
171991ed5349SWolfram Sang }
172091ed5349SWolfram Sang
__unregister_client(struct device * dev,void * dummy)172191ed5349SWolfram Sang static int __unregister_client(struct device *dev, void *dummy)
172291ed5349SWolfram Sang {
172391ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev);
172491ed5349SWolfram Sang if (client && strcmp(client->name, "dummy"))
172591ed5349SWolfram Sang i2c_unregister_device(client);
172691ed5349SWolfram Sang return 0;
172791ed5349SWolfram Sang }
172891ed5349SWolfram Sang
__unregister_dummy(struct device * dev,void * dummy)172991ed5349SWolfram Sang static int __unregister_dummy(struct device *dev, void *dummy)
173091ed5349SWolfram Sang {
173191ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev);
173291ed5349SWolfram Sang i2c_unregister_device(client);
173391ed5349SWolfram Sang return 0;
173491ed5349SWolfram Sang }
173591ed5349SWolfram Sang
__process_removed_adapter(struct device_driver * d,void * data)173691ed5349SWolfram Sang static int __process_removed_adapter(struct device_driver *d, void *data)
173791ed5349SWolfram Sang {
173891ed5349SWolfram Sang i2c_do_del_adapter(to_i2c_driver(d), data);
173991ed5349SWolfram Sang return 0;
174091ed5349SWolfram Sang }
174191ed5349SWolfram Sang
174291ed5349SWolfram Sang /**
174391ed5349SWolfram Sang * i2c_del_adapter - unregister I2C adapter
174491ed5349SWolfram Sang * @adap: the adapter being unregistered
174591ed5349SWolfram Sang * Context: can sleep
174691ed5349SWolfram Sang *
174791ed5349SWolfram Sang * This unregisters an I2C adapter which was previously registered
174891ed5349SWolfram Sang * by @i2c_add_adapter or @i2c_add_numbered_adapter.
174991ed5349SWolfram Sang */
i2c_del_adapter(struct i2c_adapter * adap)175091ed5349SWolfram Sang void i2c_del_adapter(struct i2c_adapter *adap)
175191ed5349SWolfram Sang {
175291ed5349SWolfram Sang struct i2c_adapter *found;
175391ed5349SWolfram Sang struct i2c_client *client, *next;
175491ed5349SWolfram Sang
175591ed5349SWolfram Sang /* First make sure that this adapter was ever added */
175691ed5349SWolfram Sang mutex_lock(&core_lock);
175791ed5349SWolfram Sang found = idr_find(&i2c_adapter_idr, adap->nr);
175891ed5349SWolfram Sang mutex_unlock(&core_lock);
175991ed5349SWolfram Sang if (found != adap) {
176091ed5349SWolfram Sang pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name);
176191ed5349SWolfram Sang return;
176291ed5349SWolfram Sang }
176391ed5349SWolfram Sang
176491ed5349SWolfram Sang i2c_acpi_remove_space_handler(adap);
176591ed5349SWolfram Sang /* Tell drivers about this removal */
176691ed5349SWolfram Sang mutex_lock(&core_lock);
176791ed5349SWolfram Sang bus_for_each_drv(&i2c_bus_type, NULL, adap,
176891ed5349SWolfram Sang __process_removed_adapter);
176991ed5349SWolfram Sang mutex_unlock(&core_lock);
177091ed5349SWolfram Sang
177191ed5349SWolfram Sang /* Remove devices instantiated from sysfs */
177291ed5349SWolfram Sang mutex_lock_nested(&adap->userspace_clients_lock,
177391ed5349SWolfram Sang i2c_adapter_depth(adap));
177491ed5349SWolfram Sang list_for_each_entry_safe(client, next, &adap->userspace_clients,
177591ed5349SWolfram Sang detected) {
177691ed5349SWolfram Sang dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,
177791ed5349SWolfram Sang client->addr);
177891ed5349SWolfram Sang list_del(&client->detected);
177991ed5349SWolfram Sang i2c_unregister_device(client);
178091ed5349SWolfram Sang }
178191ed5349SWolfram Sang mutex_unlock(&adap->userspace_clients_lock);
178291ed5349SWolfram Sang
178391ed5349SWolfram Sang /* Detach any active clients. This can't fail, thus we do not
178491ed5349SWolfram Sang * check the returned value. This is a two-pass process, because
178591ed5349SWolfram Sang * we can't remove the dummy devices during the first pass: they
178691ed5349SWolfram Sang * could have been instantiated by real devices wishing to clean
178707740c92SYicong Yang * them up properly, so we give them a chance to do that first. */
178807740c92SYicong Yang device_for_each_child(&adap->dev, NULL, __unregister_client);
178907740c92SYicong Yang device_for_each_child(&adap->dev, NULL, __unregister_dummy);
179007740c92SYicong Yang
179107740c92SYicong Yang #ifdef CONFIG_I2C_COMPAT
179207740c92SYicong Yang class_compat_remove_link(i2c_adapter_compat_class, &adap->dev,
179307740c92SYicong Yang adap->dev.parent);
179407740c92SYicong Yang #endif
179507740c92SYicong Yang
179607740c92SYicong Yang /* device name is gone after device_unregister */
179707740c92SYicong Yang dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
179807740c92SYicong Yang
179907740c92SYicong Yang pm_runtime_disable(&adap->dev);
180007740c92SYicong Yang
180107740c92SYicong Yang i2c_host_notify_irq_teardown(adap);
180207740c92SYicong Yang
180307740c92SYicong Yang /* wait until all references to the device are gone
180407740c92SYicong Yang *
180507740c92SYicong Yang * FIXME: This is old code and should ideally be replaced by an
180607740c92SYicong Yang * alternative which results in decoupling the lifetime of the struct
180707740c92SYicong Yang * device from the i2c_adapter, like spi or netdev do. Any solution
180807740c92SYicong Yang * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled!
180907740c92SYicong Yang */
181007740c92SYicong Yang init_completion(&adap->dev_released);
181107740c92SYicong Yang device_unregister(&adap->dev);
181207740c92SYicong Yang wait_for_completion(&adap->dev_released);
1813373c612dSRussell King (Oracle)
1814373c612dSRussell King (Oracle) /* free bus id */
1815373c612dSRussell King (Oracle) mutex_lock(&core_lock);
1816373c612dSRussell King (Oracle) idr_remove(&i2c_adapter_idr, adap->nr);
1817373c612dSRussell King (Oracle) mutex_unlock(&core_lock);
1818373c612dSRussell King (Oracle)
1819373c612dSRussell King (Oracle) /* Clear the device structure in case this adapter is ever going to be
1820373c612dSRussell King (Oracle) added again */
1821373c612dSRussell King (Oracle) memset(&adap->dev, 0, sizeof(adap->dev));
1822373c612dSRussell King (Oracle) }
1823373c612dSRussell King (Oracle) EXPORT_SYMBOL(i2c_del_adapter);
1824373c612dSRussell King (Oracle)
devm_i2c_del_adapter(void * adapter)1825373c612dSRussell King (Oracle) static void devm_i2c_del_adapter(void *adapter)
1826373c612dSRussell King (Oracle) {
1827373c612dSRussell King (Oracle) i2c_del_adapter(adapter);
1828373c612dSRussell King (Oracle) }
1829373c612dSRussell King (Oracle)
1830373c612dSRussell King (Oracle) /**
1831373c612dSRussell King (Oracle) * devm_i2c_add_adapter - device-managed variant of i2c_add_adapter()
1832373c612dSRussell King (Oracle) * @dev: managing device for adding this I2C adapter
1833373c612dSRussell King (Oracle) * @adapter: the adapter to add
1834373c612dSRussell King (Oracle) * Context: can sleep
1835373c612dSRussell King (Oracle) *
1836373c612dSRussell King (Oracle) * Add adapter with dynamic bus number, same with i2c_add_adapter()
1837373c612dSRussell King (Oracle) * but the adapter will be auto deleted on driver detach.
1838373c612dSRussell King (Oracle) */
devm_i2c_add_adapter(struct device * dev,struct i2c_adapter * adapter)1839373c612dSRussell King (Oracle) int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter)
1840373c612dSRussell King (Oracle) {
1841373c612dSRussell King (Oracle) int ret;
1842373c612dSRussell King (Oracle)
1843373c612dSRussell King (Oracle) ret = i2c_add_adapter(adapter);
1844373c612dSRussell King (Oracle) if (ret)
1845373c612dSRussell King (Oracle) return ret;
1846373c612dSRussell King (Oracle)
1847373c612dSRussell King (Oracle) return devm_add_action_or_reset(dev, devm_i2c_del_adapter, adapter);
1848373c612dSRussell King (Oracle) }
1849373c612dSRussell King (Oracle) EXPORT_SYMBOL_GPL(devm_i2c_add_adapter);
1850373c612dSRussell King (Oracle)
i2c_dev_or_parent_fwnode_match(struct device * dev,const void * data)1851373c612dSRussell King (Oracle) static int i2c_dev_or_parent_fwnode_match(struct device *dev, const void *data)
1852373c612dSRussell King (Oracle) {
1853373c612dSRussell King (Oracle) if (dev_fwnode(dev) == data)
1854373c612dSRussell King (Oracle) return 1;
1855373c612dSRussell King (Oracle)
1856373c612dSRussell King (Oracle) if (dev->parent && dev_fwnode(dev->parent) == data)
1857373c612dSRussell King (Oracle) return 1;
1858373c612dSRussell King (Oracle)
1859373c612dSRussell King (Oracle) return 0;
1860373c612dSRussell King (Oracle) }
1861373c612dSRussell King (Oracle)
1862373c612dSRussell King (Oracle) /**
1863373c612dSRussell King (Oracle) * i2c_find_adapter_by_fwnode() - find an i2c_adapter for the fwnode
1864373c612dSRussell King (Oracle) * @fwnode: &struct fwnode_handle corresponding to the &struct i2c_adapter
1865373c612dSRussell King (Oracle) *
1866373c612dSRussell King (Oracle) * Look up and return the &struct i2c_adapter corresponding to the @fwnode.
1867373c612dSRussell King (Oracle) * If no adapter can be found, or @fwnode is NULL, this returns NULL.
1868373c612dSRussell King (Oracle) *
1869373c612dSRussell King (Oracle) * The user must call put_device(&adapter->dev) once done with the i2c adapter.
1870373c612dSRussell King (Oracle) */
i2c_find_adapter_by_fwnode(struct fwnode_handle * fwnode)1871373c612dSRussell King (Oracle) struct i2c_adapter *i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode)
1872373c612dSRussell King (Oracle) {
1873373c612dSRussell King (Oracle) struct i2c_adapter *adapter;
1874373c612dSRussell King (Oracle) struct device *dev;
1875373c612dSRussell King (Oracle)
1876373c612dSRussell King (Oracle) if (!fwnode)
1877373c612dSRussell King (Oracle) return NULL;
1878373c612dSRussell King (Oracle)
1879373c612dSRussell King (Oracle) dev = bus_find_device(&i2c_bus_type, NULL, fwnode,
1880373c612dSRussell King (Oracle) i2c_dev_or_parent_fwnode_match);
1881373c612dSRussell King (Oracle) if (!dev)
1882def00b32SWolfram Sang return NULL;
1883def00b32SWolfram Sang
1884def00b32SWolfram Sang adapter = i2c_verify_adapter(dev);
1885def00b32SWolfram Sang if (!adapter)
1886def00b32SWolfram Sang put_device(dev);
1887def00b32SWolfram Sang
1888def00b32SWolfram Sang return adapter;
1889def00b32SWolfram Sang }
1890def00b32SWolfram Sang EXPORT_SYMBOL(i2c_find_adapter_by_fwnode);
1891def00b32SWolfram Sang
1892def00b32SWolfram Sang /**
1893def00b32SWolfram Sang * i2c_get_adapter_by_fwnode() - find an i2c_adapter for the fwnode
189491ed5349SWolfram Sang * @fwnode: &struct fwnode_handle corresponding to the &struct i2c_adapter
189591ed5349SWolfram Sang *
189691ed5349SWolfram Sang * Look up and return the &struct i2c_adapter corresponding to the @fwnode,
189791ed5349SWolfram Sang * and increment the adapter module's use count. If no adapter can be found,
189891ed5349SWolfram Sang * or @fwnode is NULL, this returns NULL.
1899263a5646SAndy Shevchenko *
190091ed5349SWolfram Sang * The user must call i2c_put_adapter(adapter) once done with the i2c adapter.
190191ed5349SWolfram Sang * Note that this is different from i2c_find_adapter_by_node().
190291ed5349SWolfram Sang */
i2c_get_adapter_by_fwnode(struct fwnode_handle * fwnode)190391ed5349SWolfram Sang struct i2c_adapter *i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode)
190491ed5349SWolfram Sang {
1905263a5646SAndy Shevchenko struct i2c_adapter *adapter;
1906263a5646SAndy Shevchenko
1907263a5646SAndy Shevchenko adapter = i2c_find_adapter_by_fwnode(fwnode);
1908263a5646SAndy Shevchenko if (!adapter)
190991ed5349SWolfram Sang return NULL;
191091ed5349SWolfram Sang
191191ed5349SWolfram Sang if (!try_module_get(adapter->owner)) {
1912def00b32SWolfram Sang put_device(&adapter->dev);
1913def00b32SWolfram Sang adapter = NULL;
191491ed5349SWolfram Sang }
1915def00b32SWolfram Sang
1916def00b32SWolfram Sang return adapter;
191791ed5349SWolfram Sang }
1918def00b32SWolfram Sang EXPORT_SYMBOL(i2c_get_adapter_by_fwnode);
1919def00b32SWolfram Sang
i2c_parse_timing(struct device * dev,char * prop_name,u32 * cur_val_p,u32 def_val,bool use_def)1920def00b32SWolfram Sang static void i2c_parse_timing(struct device *dev, char *prop_name, u32 *cur_val_p,
192191ed5349SWolfram Sang u32 def_val, bool use_def)
1922def00b32SWolfram Sang {
1923def00b32SWolfram Sang int ret;
192491ed5349SWolfram Sang
1925def00b32SWolfram Sang ret = device_property_read_u32(dev, prop_name, cur_val_p);
1926def00b32SWolfram Sang if (ret && use_def)
1927def00b32SWolfram Sang *cur_val_p = def_val;
1928def00b32SWolfram Sang
1929def00b32SWolfram Sang dev_dbg(dev, "%s: %u\n", prop_name, *cur_val_p);
1930def00b32SWolfram Sang }
1931def00b32SWolfram Sang
1932def00b32SWolfram Sang /**
1933def00b32SWolfram Sang * i2c_parse_fw_timings - get I2C related timing parameters from firmware
193491ed5349SWolfram Sang * @dev: The device to scan for I2C timing properties
193591ed5349SWolfram Sang * @t: the i2c_timings struct to be filled with values
193691ed5349SWolfram Sang * @use_defaults: bool to use sane defaults derived from the I2C specification
193791ed5349SWolfram Sang * when properties are not found, otherwise don't update
193891ed5349SWolfram Sang *
1939edd7a563SWolfram Sang * Scan the device for the generic I2C properties describing timing parameters
194091ed5349SWolfram Sang * for the signal and fill the given struct with the results. If a property was
194191ed5349SWolfram Sang * not found and use_defaults was true, then maximum timings are assumed which
194291ed5349SWolfram Sang * are derived from the I2C specification. If use_defaults is not used, the
194391ed5349SWolfram Sang * results will be as before, so drivers can apply their own defaults before
194491ed5349SWolfram Sang * calling this helper. The latter is mainly intended for avoiding regressions
194591ed5349SWolfram Sang * of existing drivers which want to switch to this function. New drivers
194691ed5349SWolfram Sang * almost always should use the defaults.
194791ed5349SWolfram Sang */
i2c_parse_fw_timings(struct device * dev,struct i2c_timings * t,bool use_defaults)194891ed5349SWolfram Sang void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults)
194991ed5349SWolfram Sang {
195091ed5349SWolfram Sang bool u = use_defaults;
195191ed5349SWolfram Sang u32 d;
195291ed5349SWolfram Sang
195391ed5349SWolfram Sang i2c_parse_timing(dev, "clock-frequency", &t->bus_freq_hz,
195491ed5349SWolfram Sang I2C_MAX_STANDARD_MODE_FREQ, u);
195591ed5349SWolfram Sang
195691ed5349SWolfram Sang d = t->bus_freq_hz <= I2C_MAX_STANDARD_MODE_FREQ ? 1000 :
195791ed5349SWolfram Sang t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120;
195891ed5349SWolfram Sang i2c_parse_timing(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns, d, u);
195991ed5349SWolfram Sang
196091ed5349SWolfram Sang d = t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120;
196191ed5349SWolfram Sang i2c_parse_timing(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns, d, u);
196291ed5349SWolfram Sang
196391ed5349SWolfram Sang i2c_parse_timing(dev, "i2c-scl-internal-delay-ns",
196491ed5349SWolfram Sang &t->scl_int_delay_ns, 0, u);
196591ed5349SWolfram Sang i2c_parse_timing(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns,
196691ed5349SWolfram Sang t->scl_fall_ns, u);
196791ed5349SWolfram Sang i2c_parse_timing(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns, 0, u);
196891ed5349SWolfram Sang i2c_parse_timing(dev, "i2c-digital-filter-width-ns",
196991ed5349SWolfram Sang &t->digital_filter_width_ns, 0, u);
197091ed5349SWolfram Sang i2c_parse_timing(dev, "i2c-analog-filter-cutoff-frequency",
197191ed5349SWolfram Sang &t->analog_filter_cutoff_freq_hz, 0, u);
197291ed5349SWolfram Sang }
197391ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_parse_fw_timings);
197491ed5349SWolfram Sang
197591ed5349SWolfram Sang /* ------------------------------------------------------------------------- */
197691ed5349SWolfram Sang
i2c_for_each_dev(void * data,int (* fn)(struct device * dev,void * data))197791ed5349SWolfram Sang int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data))
197891ed5349SWolfram Sang {
197991ed5349SWolfram Sang int res;
198091ed5349SWolfram Sang
198191ed5349SWolfram Sang mutex_lock(&core_lock);
198291ed5349SWolfram Sang res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn);
198391ed5349SWolfram Sang mutex_unlock(&core_lock);
198491ed5349SWolfram Sang
198591ed5349SWolfram Sang return res;
198691ed5349SWolfram Sang }
198791ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_for_each_dev);
198891ed5349SWolfram Sang
__process_new_driver(struct device * dev,void * data)198991ed5349SWolfram Sang static int __process_new_driver(struct device *dev, void *data)
199091ed5349SWolfram Sang {
199191ed5349SWolfram Sang if (dev->type != &i2c_adapter_type)
199291ed5349SWolfram Sang return 0;
199391ed5349SWolfram Sang return i2c_do_add_adapter(data, to_i2c_adapter(dev));
199491ed5349SWolfram Sang }
199591ed5349SWolfram Sang
199691ed5349SWolfram Sang /*
199791ed5349SWolfram Sang * An i2c_driver is used with one or more i2c_client (device) nodes to access
199891ed5349SWolfram Sang * i2c slave chips, on a bus instance associated with some i2c_adapter.
199991ed5349SWolfram Sang */
200091ed5349SWolfram Sang
i2c_register_driver(struct module * owner,struct i2c_driver * driver)200191ed5349SWolfram Sang int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
200291ed5349SWolfram Sang {
200391ed5349SWolfram Sang int res;
200491ed5349SWolfram Sang
200591ed5349SWolfram Sang /* Can't register until after driver model init */
200691ed5349SWolfram Sang if (WARN_ON(!is_registered))
200791ed5349SWolfram Sang return -EAGAIN;
200891ed5349SWolfram Sang
200991ed5349SWolfram Sang /* add the driver to the list of i2c drivers in the driver core */
201091ed5349SWolfram Sang driver->driver.owner = owner;
201191ed5349SWolfram Sang driver->driver.bus = &i2c_bus_type;
201291ed5349SWolfram Sang INIT_LIST_HEAD(&driver->clients);
201391ed5349SWolfram Sang
201491ed5349SWolfram Sang /* When registration returns, the driver core
201591ed5349SWolfram Sang * will have called probe() for all matching-but-unbound devices.
201691ed5349SWolfram Sang */
201791ed5349SWolfram Sang res = driver_register(&driver->driver);
201891ed5349SWolfram Sang if (res)
201991ed5349SWolfram Sang return res;
202091ed5349SWolfram Sang
202191ed5349SWolfram Sang pr_debug("driver [%s] registered\n", driver->driver.name);
202291ed5349SWolfram Sang
202391ed5349SWolfram Sang /* Walk the adapters that are already present */
202491ed5349SWolfram Sang i2c_for_each_dev(driver, __process_new_driver);
202591ed5349SWolfram Sang
202691ed5349SWolfram Sang return 0;
202791ed5349SWolfram Sang }
202891ed5349SWolfram Sang EXPORT_SYMBOL(i2c_register_driver);
202991ed5349SWolfram Sang
__process_removed_driver(struct device * dev,void * data)203091ed5349SWolfram Sang static int __process_removed_driver(struct device *dev, void *data)
203191ed5349SWolfram Sang {
203291ed5349SWolfram Sang if (dev->type == &i2c_adapter_type)
203391ed5349SWolfram Sang i2c_do_del_adapter(data, to_i2c_adapter(dev));
203491ed5349SWolfram Sang return 0;
203591ed5349SWolfram Sang }
203691ed5349SWolfram Sang
203791ed5349SWolfram Sang /**
203891ed5349SWolfram Sang * i2c_del_driver - unregister I2C driver
203991ed5349SWolfram Sang * @driver: the driver being unregistered
204091ed5349SWolfram Sang * Context: can sleep
204191ed5349SWolfram Sang */
i2c_del_driver(struct i2c_driver * driver)204291ed5349SWolfram Sang void i2c_del_driver(struct i2c_driver *driver)
204391ed5349SWolfram Sang {
204491ed5349SWolfram Sang i2c_for_each_dev(driver, __process_removed_driver);
204591ed5349SWolfram Sang
204691ed5349SWolfram Sang driver_unregister(&driver->driver);
204791ed5349SWolfram Sang pr_debug("driver [%s] unregistered\n", driver->driver.name);
204891ed5349SWolfram Sang }
204991ed5349SWolfram Sang EXPORT_SYMBOL(i2c_del_driver);
205091ed5349SWolfram Sang
205191ed5349SWolfram Sang /* ------------------------------------------------------------------------- */
205291ed5349SWolfram Sang
205391ed5349SWolfram Sang struct i2c_cmd_arg {
205491ed5349SWolfram Sang unsigned cmd;
205591ed5349SWolfram Sang void *arg;
205691ed5349SWolfram Sang };
205791ed5349SWolfram Sang
i2c_cmd(struct device * dev,void * _arg)205891ed5349SWolfram Sang static int i2c_cmd(struct device *dev, void *_arg)
205991ed5349SWolfram Sang {
206091ed5349SWolfram Sang struct i2c_client *client = i2c_verify_client(dev);
206191ed5349SWolfram Sang struct i2c_cmd_arg *arg = _arg;
206291ed5349SWolfram Sang struct i2c_driver *driver;
206391ed5349SWolfram Sang
206491ed5349SWolfram Sang if (!client || !client->dev.driver)
206591ed5349SWolfram Sang return 0;
206691ed5349SWolfram Sang
206791ed5349SWolfram Sang driver = to_i2c_driver(client->dev.driver);
206891ed5349SWolfram Sang if (driver->command)
206991ed5349SWolfram Sang driver->command(client, arg->cmd, arg->arg);
207091ed5349SWolfram Sang return 0;
207191ed5349SWolfram Sang }
207291ed5349SWolfram Sang
i2c_clients_command(struct i2c_adapter * adap,unsigned int cmd,void * arg)207391ed5349SWolfram Sang void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
207491ed5349SWolfram Sang {
207591ed5349SWolfram Sang struct i2c_cmd_arg cmd_arg;
207691ed5349SWolfram Sang
207791ed5349SWolfram Sang cmd_arg.cmd = cmd;
207891ed5349SWolfram Sang cmd_arg.arg = arg;
207991ed5349SWolfram Sang device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd);
208091ed5349SWolfram Sang }
208191ed5349SWolfram Sang EXPORT_SYMBOL(i2c_clients_command);
208291ed5349SWolfram Sang
i2c_init(void)208391ed5349SWolfram Sang static int __init i2c_init(void)
208491ed5349SWolfram Sang {
208591ed5349SWolfram Sang int retval;
208691ed5349SWolfram Sang
208791ed5349SWolfram Sang retval = of_alias_get_highest_id("i2c");
208891ed5349SWolfram Sang
208991ed5349SWolfram Sang down_write(&__i2c_board_lock);
209091ed5349SWolfram Sang if (retval >= __i2c_first_dynamic_bus_num)
209191ed5349SWolfram Sang __i2c_first_dynamic_bus_num = retval + 1;
209291ed5349SWolfram Sang up_write(&__i2c_board_lock);
209391ed5349SWolfram Sang
209491ed5349SWolfram Sang retval = bus_register(&i2c_bus_type);
209591ed5349SWolfram Sang if (retval)
209691ed5349SWolfram Sang return retval;
209791ed5349SWolfram Sang
209891ed5349SWolfram Sang is_registered = true;
209991ed5349SWolfram Sang
210091ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT
210191ed5349SWolfram Sang i2c_adapter_compat_class = class_compat_register("i2c-adapter");
210291ed5349SWolfram Sang if (!i2c_adapter_compat_class) {
210391ed5349SWolfram Sang retval = -ENOMEM;
210491ed5349SWolfram Sang goto bus_err;
210591ed5349SWolfram Sang }
210691ed5349SWolfram Sang #endif
210791ed5349SWolfram Sang retval = i2c_add_driver(&dummy_driver);
210891ed5349SWolfram Sang if (retval)
210991ed5349SWolfram Sang goto class_err;
211091ed5349SWolfram Sang
211191ed5349SWolfram Sang if (IS_ENABLED(CONFIG_OF_DYNAMIC))
211291ed5349SWolfram Sang WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier));
211391ed5349SWolfram Sang if (IS_ENABLED(CONFIG_ACPI))
211491ed5349SWolfram Sang WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier));
211591ed5349SWolfram Sang
211691ed5349SWolfram Sang return 0;
211791ed5349SWolfram Sang
211891ed5349SWolfram Sang class_err:
211991ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT
212091ed5349SWolfram Sang class_compat_unregister(i2c_adapter_compat_class);
212191ed5349SWolfram Sang bus_err:
212291ed5349SWolfram Sang #endif
212391ed5349SWolfram Sang is_registered = false;
212491ed5349SWolfram Sang bus_unregister(&i2c_bus_type);
212591ed5349SWolfram Sang return retval;
212691ed5349SWolfram Sang }
212791ed5349SWolfram Sang
i2c_exit(void)212891ed5349SWolfram Sang static void __exit i2c_exit(void)
212991ed5349SWolfram Sang {
213091ed5349SWolfram Sang if (IS_ENABLED(CONFIG_ACPI))
213191ed5349SWolfram Sang WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier));
213291ed5349SWolfram Sang if (IS_ENABLED(CONFIG_OF_DYNAMIC))
213391ed5349SWolfram Sang WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier));
213491ed5349SWolfram Sang i2c_del_driver(&dummy_driver);
213591ed5349SWolfram Sang #ifdef CONFIG_I2C_COMPAT
213691ed5349SWolfram Sang class_compat_unregister(i2c_adapter_compat_class);
213791ed5349SWolfram Sang #endif
213891ed5349SWolfram Sang bus_unregister(&i2c_bus_type);
213991ed5349SWolfram Sang tracepoint_synchronize_unregister();
214091ed5349SWolfram Sang }
214191ed5349SWolfram Sang
214291ed5349SWolfram Sang /* We must initialize early, because some subsystems register i2c drivers
214391ed5349SWolfram Sang * in subsys_initcall() code, but are linked (and initialized) before i2c.
214491ed5349SWolfram Sang */
214591ed5349SWolfram Sang postcore_initcall(i2c_init);
214691ed5349SWolfram Sang module_exit(i2c_exit);
214791ed5349SWolfram Sang
214891ed5349SWolfram Sang /* ----------------------------------------------------
214991ed5349SWolfram Sang * the functional interface to the i2c busses.
215091ed5349SWolfram Sang * ----------------------------------------------------
215191ed5349SWolfram Sang */
215291ed5349SWolfram Sang
215391ed5349SWolfram Sang /* Check if val is exceeding the quirk IFF quirk is non 0 */
215491ed5349SWolfram Sang #define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk)))
215591ed5349SWolfram Sang
i2c_quirk_error(struct i2c_adapter * adap,struct i2c_msg * msg,char * err_msg)215691ed5349SWolfram Sang static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg)
215791ed5349SWolfram Sang {
215891ed5349SWolfram Sang dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n",
215991ed5349SWolfram Sang err_msg, msg->addr, msg->len,
216091ed5349SWolfram Sang msg->flags & I2C_M_RD ? "read" : "write");
216191ed5349SWolfram Sang return -EOPNOTSUPP;
216291ed5349SWolfram Sang }
216391ed5349SWolfram Sang
i2c_check_for_quirks(struct i2c_adapter * adap,struct i2c_msg * msgs,int num)216491ed5349SWolfram Sang static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
2165d9cfe2ceSWolfram Sang {
2166d9cfe2ceSWolfram Sang const struct i2c_adapter_quirks *q = adap->quirks;
2167d9cfe2ceSWolfram Sang int max_num = q->max_num_msgs, i;
216891ed5349SWolfram Sang bool do_len_check = true;
216991ed5349SWolfram Sang
217091ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB) {
2171d9cfe2ceSWolfram Sang max_num = 2;
2172d9cfe2ceSWolfram Sang
2173d9cfe2ceSWolfram Sang /* special checks for combined messages */
217491ed5349SWolfram Sang if (num == 2) {
217591ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD)
217691ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write");
217791ed5349SWolfram Sang
217891ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD))
217991ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read");
218091ed5349SWolfram Sang
218191ed5349SWolfram Sang if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr)
218291ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr");
218391ed5349SWolfram Sang
218491ed5349SWolfram Sang if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len))
218591ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "msg too long");
218691ed5349SWolfram Sang
218791ed5349SWolfram Sang if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len))
218891ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[1], "msg too long");
218991ed5349SWolfram Sang
2190e3425674SWolfram Sang do_len_check = false;
219191ed5349SWolfram Sang }
219291ed5349SWolfram Sang }
219391ed5349SWolfram Sang
219491ed5349SWolfram Sang if (i2c_quirk_exceeded(num, max_num))
219591ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[0], "too many messages");
219691ed5349SWolfram Sang
2197e3425674SWolfram Sang for (i = 0; i < num; i++) {
2198e3425674SWolfram Sang u16 len = msgs[i].len;
2199e3425674SWolfram Sang
2200e3425674SWolfram Sang if (msgs[i].flags & I2C_M_RD) {
2201e3425674SWolfram Sang if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len))
22021eace834SArd Biesheuvel return i2c_quirk_error(adap, &msgs[i], "msg too long");
22031eace834SArd Biesheuvel
22045d756112SWolfram Sang if (q->flags & I2C_AQ_NO_ZERO_LEN_READ && len == 0)
22055d756112SWolfram Sang return i2c_quirk_error(adap, &msgs[i], "no zero length");
22065d756112SWolfram Sang } else {
22075d756112SWolfram Sang if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len))
22081eace834SArd Biesheuvel return i2c_quirk_error(adap, &msgs[i], "msg too long");
220991ed5349SWolfram Sang
221091ed5349SWolfram Sang if (q->flags & I2C_AQ_NO_ZERO_LEN_WRITE && len == 0)
221191ed5349SWolfram Sang return i2c_quirk_error(adap, &msgs[i], "no zero length");
221250888b01SDavidlohr Bueso }
221350888b01SDavidlohr Bueso }
221491ed5349SWolfram Sang
221591ed5349SWolfram Sang return 0;
221691ed5349SWolfram Sang }
221750888b01SDavidlohr Bueso
221891ed5349SWolfram Sang /**
221991ed5349SWolfram Sang * __i2c_transfer - unlocked flavor of i2c_transfer
222091ed5349SWolfram Sang * @adap: Handle to I2C bus
222191ed5349SWolfram Sang * @msgs: One or more messages to execute before STOP is issued to
222291ed5349SWolfram Sang * terminate the operation; each message begins with a START.
222391ed5349SWolfram Sang * @num: Number of messages to be executed.
222491ed5349SWolfram Sang *
222591ed5349SWolfram Sang * Returns negative errno, else the number of messages executed.
222691ed5349SWolfram Sang *
222791ed5349SWolfram Sang * Adapter lock must be held when calling this function. No debug logging
222891ed5349SWolfram Sang * takes place.
222963b96983SWolfram Sang */
__i2c_transfer(struct i2c_adapter * adap,struct i2c_msg * msgs,int num)223063b96983SWolfram Sang int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
223163b96983SWolfram Sang {
223291ed5349SWolfram Sang unsigned long orig_jiffies;
223363b96983SWolfram Sang int ret, try;
223491ed5349SWolfram Sang
223591ed5349SWolfram Sang if (!adap->algo->master_xfer) {
223691ed5349SWolfram Sang dev_dbg(&adap->dev, "I2C level transfers not supported\n");
223791ed5349SWolfram Sang return -EOPNOTSUPP;
223891ed5349SWolfram Sang }
223991ed5349SWolfram Sang
224050888b01SDavidlohr Bueso if (WARN_ON(!msgs || num < 1))
224191ed5349SWolfram Sang return -EINVAL;
224291ed5349SWolfram Sang
224391ed5349SWolfram Sang ret = __i2c_check_suspended(adap);
224491ed5349SWolfram Sang if (ret)
22454a3f7691SAhbong Chang return ret;
224691ed5349SWolfram Sang
224791ed5349SWolfram Sang if (adap->quirks && i2c_check_for_quirks(adap, msgs, num))
224891ed5349SWolfram Sang return -EOPNOTSUPP;
224991ed5349SWolfram Sang
225091ed5349SWolfram Sang /*
225191ed5349SWolfram Sang * i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets
225291ed5349SWolfram Sang * enabled. This is an efficient way of keeping the for-loop from
225391ed5349SWolfram Sang * being executed when not needed.
225491ed5349SWolfram Sang */
225591ed5349SWolfram Sang if (static_branch_unlikely(&i2c_trace_msg_key)) {
225691ed5349SWolfram Sang int i;
225791ed5349SWolfram Sang for (i = 0; i < num; i++)
225891ed5349SWolfram Sang if (msgs[i].flags & I2C_M_RD)
225991ed5349SWolfram Sang trace_i2c_read(adap, &msgs[i], i);
226091ed5349SWolfram Sang else
226191ed5349SWolfram Sang trace_i2c_write(adap, &msgs[i], i);
226291ed5349SWolfram Sang }
226391ed5349SWolfram Sang
226491ed5349SWolfram Sang /* Retry automatically on arbitration loss */
226591ed5349SWolfram Sang orig_jiffies = jiffies;
226691ed5349SWolfram Sang for (ret = 0, try = 0; try <= adap->retries; try++) {
226791ed5349SWolfram Sang if (i2c_in_atomic_xfer_mode() && adap->algo->master_xfer_atomic)
226891ed5349SWolfram Sang ret = adap->algo->master_xfer_atomic(adap, msgs, num);
226991ed5349SWolfram Sang else
227091ed5349SWolfram Sang ret = adap->algo->master_xfer(adap, msgs, num);
227191ed5349SWolfram Sang
227291ed5349SWolfram Sang if (ret != -EAGAIN)
227391ed5349SWolfram Sang break;
227491ed5349SWolfram Sang if (time_after(jiffies, orig_jiffies + adap->timeout))
227591ed5349SWolfram Sang break;
227691ed5349SWolfram Sang }
227791ed5349SWolfram Sang
227891ed5349SWolfram Sang if (static_branch_unlikely(&i2c_trace_msg_key)) {
227991ed5349SWolfram Sang int i;
228091ed5349SWolfram Sang for (i = 0; i < ret; i++)
228191ed5349SWolfram Sang if (msgs[i].flags & I2C_M_RD)
228291ed5349SWolfram Sang trace_i2c_reply(adap, &msgs[i], i);
228391ed5349SWolfram Sang trace_i2c_result(adap, num, ret);
228483c42212SWolfram Sang }
228583c42212SWolfram Sang
228683c42212SWolfram Sang return ret;
228791ed5349SWolfram Sang }
228891ed5349SWolfram Sang EXPORT_SYMBOL(__i2c_transfer);
228991ed5349SWolfram Sang
229091ed5349SWolfram Sang /**
229191ed5349SWolfram Sang * i2c_transfer - execute a single or combined I2C message
229291ed5349SWolfram Sang * @adap: Handle to I2C bus
229391ed5349SWolfram Sang * @msgs: One or more messages to execute before STOP is issued to
229491ed5349SWolfram Sang * terminate the operation; each message begins with a START.
229591ed5349SWolfram Sang * @num: Number of messages to be executed.
22968a91732bSWolfram Sang *
22978a91732bSWolfram Sang * Returns negative errno, else the number of messages executed.
229891ed5349SWolfram Sang *
22998a91732bSWolfram Sang * Note that there is no requirement that each message be sent to
23008a91732bSWolfram Sang * the same slave address, although that is the most common model.
23018a91732bSWolfram Sang */
i2c_transfer(struct i2c_adapter * adap,struct i2c_msg * msgs,int num)230291ed5349SWolfram Sang int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
23038a91732bSWolfram Sang {
230491ed5349SWolfram Sang int ret;
23058a91732bSWolfram Sang
23068a91732bSWolfram Sang /* REVISIT the fault reporting model here is weak:
230791ed5349SWolfram Sang *
230891ed5349SWolfram Sang * - When we get an error after receiving N bytes from a slave,
23098a91732bSWolfram Sang * there is no way to report "N".
23108a91732bSWolfram Sang *
23118a91732bSWolfram Sang * - When we get a NAK after transmitting N bytes to a slave,
23128a91732bSWolfram Sang * there is no way to report "N" ... or to let the master
23138a91732bSWolfram Sang * continue executing the rest of this combined message, if
23148a91732bSWolfram Sang * that's the appropriate response.
231591ed5349SWolfram Sang *
23168a91732bSWolfram Sang * - When for example "num" is two and we successfully complete
231791ed5349SWolfram Sang * the first message but get an error part way through the
231891ed5349SWolfram Sang * second, it's unclear whether that should be reported as
23198a91732bSWolfram Sang * one (discarding status on the second message) or errno
23208a91732bSWolfram Sang * (discarding status on the first one).
232191ed5349SWolfram Sang */
232291ed5349SWolfram Sang ret = __i2c_lock_bus_helper(adap);
232391ed5349SWolfram Sang if (ret)
23248a91732bSWolfram Sang return ret;
232591ed5349SWolfram Sang
2326dde67eb1SPeter Rosin ret = __i2c_transfer(adap, msgs, num);
2327dde67eb1SPeter Rosin i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);
2328dde67eb1SPeter Rosin
2329dde67eb1SPeter Rosin return ret;
2330dde67eb1SPeter Rosin }
2331dde67eb1SPeter Rosin EXPORT_SYMBOL(i2c_transfer);
2332dde67eb1SPeter Rosin
2333dde67eb1SPeter Rosin /**
2334dde67eb1SPeter Rosin * i2c_transfer_buffer_flags - issue a single I2C message transferring data
2335dde67eb1SPeter Rosin * to/from a buffer
2336dde67eb1SPeter Rosin * @client: Handle to slave device
2337dde67eb1SPeter Rosin * @buf: Where the data is stored
2338dde67eb1SPeter Rosin * @count: How many bytes to transfer, must be less than 64k since msg.len is u16
2339dde67eb1SPeter Rosin * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads
2340dde67eb1SPeter Rosin *
2341dde67eb1SPeter Rosin * Returns negative errno, or else the number of bytes transferred.
2342dde67eb1SPeter Rosin */
i2c_transfer_buffer_flags(const struct i2c_client * client,char * buf,int count,u16 flags)2343dde67eb1SPeter Rosin int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf,
2344dde67eb1SPeter Rosin int count, u16 flags)
2345dde67eb1SPeter Rosin {
2346dde67eb1SPeter Rosin int ret;
2347dde67eb1SPeter Rosin struct i2c_msg msg = {
2348dde67eb1SPeter Rosin .addr = client->addr,
2349dde67eb1SPeter Rosin .flags = flags | (client->flags & I2C_M_TEN),
2350dde67eb1SPeter Rosin .len = count,
2351dde67eb1SPeter Rosin .buf = buf,
2352dde67eb1SPeter Rosin };
2353dde67eb1SPeter Rosin
2354dde67eb1SPeter Rosin ret = i2c_transfer(client->adapter, &msg, 1);
2355dde67eb1SPeter Rosin
2356dde67eb1SPeter Rosin /*
235766223373SAngel Iglesias * If everything went ok (i.e. 1 msg transferred), return #bytes
235866223373SAngel Iglesias * transferred, else error code.
235966223373SAngel Iglesias */
236066223373SAngel Iglesias return (ret == 1) ? count : ret;
236166223373SAngel Iglesias }
236266223373SAngel Iglesias EXPORT_SYMBOL(i2c_transfer_buffer_flags);
236366223373SAngel Iglesias
236466223373SAngel Iglesias /**
236566223373SAngel Iglesias * i2c_get_device_id - get manufacturer, part id and die revision of a device
236666223373SAngel Iglesias * @client: The device to query
236766223373SAngel Iglesias * @id: The queried information
236866223373SAngel Iglesias *
236966223373SAngel Iglesias * Returns negative errno on error, zero on success.
237066223373SAngel Iglesias */
i2c_get_device_id(const struct i2c_client * client,struct i2c_device_identity * id)237191ed5349SWolfram Sang int i2c_get_device_id(const struct i2c_client *client,
237291ed5349SWolfram Sang struct i2c_device_identity *id)
237391ed5349SWolfram Sang {
237491ed5349SWolfram Sang struct i2c_adapter *adap = client->adapter;
237591ed5349SWolfram Sang union i2c_smbus_data raw_id;
237691ed5349SWolfram Sang int ret;
237791ed5349SWolfram Sang
237891ed5349SWolfram Sang if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
237991ed5349SWolfram Sang return -EOPNOTSUPP;
238091ed5349SWolfram Sang
238191ed5349SWolfram Sang raw_id.block[0] = 3;
238291ed5349SWolfram Sang ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0,
238391ed5349SWolfram Sang I2C_SMBUS_READ, client->addr << 1,
238491ed5349SWolfram Sang I2C_SMBUS_I2C_BLOCK_DATA, &raw_id);
238591ed5349SWolfram Sang if (ret)
238691ed5349SWolfram Sang return ret;
238791ed5349SWolfram Sang
238891ed5349SWolfram Sang id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4);
238991ed5349SWolfram Sang id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3);
239091ed5349SWolfram Sang id->die_revision = raw_id.block[3] & 0x7;
239191ed5349SWolfram Sang return 0;
239291ed5349SWolfram Sang }
239391ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_get_device_id);
239491ed5349SWolfram Sang
239591ed5349SWolfram Sang /**
239691ed5349SWolfram Sang * i2c_client_get_device_id - get the driver match table entry of a device
239791ed5349SWolfram Sang * @client: the device to query. The device must be bound to a driver
239891ed5349SWolfram Sang *
239991ed5349SWolfram Sang * Returns a pointer to the matching entry if found, NULL otherwise.
240091ed5349SWolfram Sang */
i2c_client_get_device_id(const struct i2c_client * client)240191ed5349SWolfram Sang const struct i2c_device_id *i2c_client_get_device_id(const struct i2c_client *client)
240291ed5349SWolfram Sang {
240391ed5349SWolfram Sang const struct i2c_driver *drv = to_i2c_driver(client->dev.driver);
240491ed5349SWolfram Sang
240591ed5349SWolfram Sang return i2c_match_id(drv->id_table, client);
240691ed5349SWolfram Sang }
240791ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_client_get_device_id);
240891ed5349SWolfram Sang
240991ed5349SWolfram Sang /* ----------------------------------------------------
241091ed5349SWolfram Sang * the i2c address scanning function
241191ed5349SWolfram Sang * Will not work for 10-bit addresses!
241291ed5349SWolfram Sang * ----------------------------------------------------
241391ed5349SWolfram Sang */
241491ed5349SWolfram Sang
241591ed5349SWolfram Sang /*
241691ed5349SWolfram Sang * Legacy default probe function, mostly relevant for SMBus. The default
241791ed5349SWolfram Sang * probe method is a quick write, but it is known to corrupt the 24RF08
241891ed5349SWolfram Sang * EEPROMs due to a state machine bug, and could also irreversibly
241991ed5349SWolfram Sang * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f,
242091ed5349SWolfram Sang * we use a short byte read instead. Also, some bus drivers don't implement
242191ed5349SWolfram Sang * quick write, so we fallback to a byte read in that case too.
242291ed5349SWolfram Sang * On x86, there is another special case for FSC hardware monitoring chips,
242391ed5349SWolfram Sang * which want regular byte reads (address 0x73.) Fortunately, these are the
242491ed5349SWolfram Sang * only known chips using this I2C address on PC hardware.
242591ed5349SWolfram Sang * Returns 1 if probe succeeded, 0 if not.
242691ed5349SWolfram Sang */
i2c_default_probe(struct i2c_adapter * adap,unsigned short addr)242791ed5349SWolfram Sang static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr)
242891ed5349SWolfram Sang {
242991ed5349SWolfram Sang int err;
243091ed5349SWolfram Sang union i2c_smbus_data dummy;
243191ed5349SWolfram Sang
243291ed5349SWolfram Sang #ifdef CONFIG_X86
243391ed5349SWolfram Sang if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON)
243491ed5349SWolfram Sang && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA))
243591ed5349SWolfram Sang err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
243691ed5349SWolfram Sang I2C_SMBUS_BYTE_DATA, &dummy);
243791ed5349SWolfram Sang else
243891ed5349SWolfram Sang #endif
243991ed5349SWolfram Sang if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50)
244091ed5349SWolfram Sang && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK))
244191ed5349SWolfram Sang err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0,
244291ed5349SWolfram Sang I2C_SMBUS_QUICK, NULL);
244391ed5349SWolfram Sang else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE))
244491ed5349SWolfram Sang err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
244591ed5349SWolfram Sang I2C_SMBUS_BYTE, &dummy);
244691ed5349SWolfram Sang else {
244791ed5349SWolfram Sang dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n",
244891ed5349SWolfram Sang addr);
244991ed5349SWolfram Sang err = -EOPNOTSUPP;
245091ed5349SWolfram Sang }
245191ed5349SWolfram Sang
245291ed5349SWolfram Sang return err >= 0;
245391ed5349SWolfram Sang }
245491ed5349SWolfram Sang
i2c_detect_address(struct i2c_client * temp_client,struct i2c_driver * driver)245591ed5349SWolfram Sang static int i2c_detect_address(struct i2c_client *temp_client,
245691ed5349SWolfram Sang struct i2c_driver *driver)
245791ed5349SWolfram Sang {
245891ed5349SWolfram Sang struct i2c_board_info info;
245991ed5349SWolfram Sang struct i2c_adapter *adapter = temp_client->adapter;
246091ed5349SWolfram Sang int addr = temp_client->addr;
246191ed5349SWolfram Sang int err;
246291ed5349SWolfram Sang
246391ed5349SWolfram Sang /* Make sure the address is valid */
2464ccf988b6SMauro Carvalho Chehab err = i2c_check_7bit_addr_validity_strict(addr);
246591ed5349SWolfram Sang if (err) {
246691ed5349SWolfram Sang dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
246791ed5349SWolfram Sang addr);
246891ed5349SWolfram Sang return err;
246987e07437SWolfram Sang }
247087e07437SWolfram Sang
247191ed5349SWolfram Sang /* Skip if already in use (7 bit, no need to encode flags) */
247291ed5349SWolfram Sang if (i2c_check_addr_busy(adapter, addr))
247391ed5349SWolfram Sang return 0;
247491ed5349SWolfram Sang
247591ed5349SWolfram Sang /* Make sure there is something at this address */
247691ed5349SWolfram Sang if (!i2c_default_probe(adapter, addr))
247791ed5349SWolfram Sang return 0;
247891ed5349SWolfram Sang
247991ed5349SWolfram Sang /* Finally call the custom detection function */
248091ed5349SWolfram Sang memset(&info, 0, sizeof(struct i2c_board_info));
248191ed5349SWolfram Sang info.addr = addr;
248291ed5349SWolfram Sang err = driver->detect(temp_client, &info);
248391ed5349SWolfram Sang if (err) {
248491ed5349SWolfram Sang /* -ENODEV is returned if the detection fails. We catch it
248591ed5349SWolfram Sang here as this isn't an error. */
248691ed5349SWolfram Sang return err == -ENODEV ? 0 : err;
248791ed5349SWolfram Sang }
248891ed5349SWolfram Sang
248991ed5349SWolfram Sang /* Consistency check */
249091ed5349SWolfram Sang if (info.type[0] == '\0') {
249191ed5349SWolfram Sang dev_err(&adapter->dev,
249291ed5349SWolfram Sang "%s detection function provided no name for 0x%x\n",
2493ccf988b6SMauro Carvalho Chehab driver->driver.name, addr);
249491ed5349SWolfram Sang } else {
249591ed5349SWolfram Sang struct i2c_client *client;
249691ed5349SWolfram Sang
249791ed5349SWolfram Sang /* Detection succeeded, instantiate the device */
249891ed5349SWolfram Sang if (adapter->class & I2C_CLASS_DEPRECATED)
249991ed5349SWolfram Sang dev_warn(&adapter->dev,
250091ed5349SWolfram Sang "This adapter will soon drop class based instantiation of devices. "
250191ed5349SWolfram Sang "Please make sure client 0x%02x gets instantiated by other means. "
250291ed5349SWolfram Sang "Check 'Documentation/i2c/instantiating-devices.rst' for details.\n",
250391ed5349SWolfram Sang info.addr);
250491ed5349SWolfram Sang
250591ed5349SWolfram Sang dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",
250691ed5349SWolfram Sang info.type, info.addr);
250791ed5349SWolfram Sang client = i2c_new_client_device(adapter, &info);
250891ed5349SWolfram Sang if (!IS_ERR(client))
250991ed5349SWolfram Sang list_add_tail(&client->detected, &driver->clients);
251091ed5349SWolfram Sang else
2511dd4f2ca9SWolfram Sang dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n",
251291ed5349SWolfram Sang info.type, info.addr);
251391ed5349SWolfram Sang }
251491ed5349SWolfram Sang return 0;
251591ed5349SWolfram Sang }
251691ed5349SWolfram Sang
i2c_detect(struct i2c_adapter * adapter,struct i2c_driver * driver)251791ed5349SWolfram Sang static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
251891ed5349SWolfram Sang {
251991ed5349SWolfram Sang const unsigned short *address_list;
252091ed5349SWolfram Sang struct i2c_client *temp_client;
252191ed5349SWolfram Sang int i, err = 0;
252291ed5349SWolfram Sang
252391ed5349SWolfram Sang address_list = driver->address_list;
252491ed5349SWolfram Sang if (!driver->detect || !address_list)
252591ed5349SWolfram Sang return 0;
252691ed5349SWolfram Sang
252791ed5349SWolfram Sang /* Warn that the adapter lost class based instantiation */
252891ed5349SWolfram Sang if (adapter->class == I2C_CLASS_DEPRECATED) {
252991ed5349SWolfram Sang dev_dbg(&adapter->dev,
2530c1d08475SWolfram Sang "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. "
253191ed5349SWolfram Sang "If you need it, check 'Documentation/i2c/instantiating-devices.rst' for alternatives.\n",
253291ed5349SWolfram Sang driver->driver.name);
2533edd7a563SWolfram Sang return 0;
253491ed5349SWolfram Sang }
253591ed5349SWolfram Sang
253691ed5349SWolfram Sang /* Stop here if the classes do not match */
253791ed5349SWolfram Sang if (!(adapter->class & driver->class))
253891ed5349SWolfram Sang return 0;
253991ed5349SWolfram Sang
254091ed5349SWolfram Sang /* Set up a temporary client to help detect callback */
254191ed5349SWolfram Sang temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
254291ed5349SWolfram Sang if (!temp_client)
254391ed5349SWolfram Sang return -ENOMEM;
254491ed5349SWolfram Sang temp_client->adapter = adapter;
254591ed5349SWolfram Sang
254691ed5349SWolfram Sang for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) {
254791ed5349SWolfram Sang dev_dbg(&adapter->dev,
254891ed5349SWolfram Sang "found normal entry for adapter %d, addr 0x%02x\n",
254991ed5349SWolfram Sang i2c_adapter_id(adapter), address_list[i]);
255091ed5349SWolfram Sang temp_client->addr = address_list[i];
255191ed5349SWolfram Sang err = i2c_detect_address(temp_client, driver);
255291ed5349SWolfram Sang if (unlikely(err))
255391ed5349SWolfram Sang break;
255491ed5349SWolfram Sang }
255591ed5349SWolfram Sang
255691ed5349SWolfram Sang kfree(temp_client);
255791ed5349SWolfram Sang return err;
255891ed5349SWolfram Sang }
255991ed5349SWolfram Sang
i2c_probe_func_quick_read(struct i2c_adapter * adap,unsigned short addr)256091ed5349SWolfram Sang int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr)
256191ed5349SWolfram Sang {
256291ed5349SWolfram Sang return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
2563c1d08475SWolfram Sang I2C_SMBUS_QUICK, NULL) >= 0;
256491ed5349SWolfram Sang }
256591ed5349SWolfram Sang EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read);
256691ed5349SWolfram Sang
2567c1d08475SWolfram Sang struct i2c_client *
i2c_new_scanned_device(struct i2c_adapter * adap,struct i2c_board_info * info,unsigned short const * addr_list,int (* probe)(struct i2c_adapter * adap,unsigned short addr))2568c1d08475SWolfram Sang i2c_new_scanned_device(struct i2c_adapter *adap,
2569c1d08475SWolfram Sang struct i2c_board_info *info,
2570c1d08475SWolfram Sang unsigned short const *addr_list,
257191ed5349SWolfram Sang int (*probe)(struct i2c_adapter *adap, unsigned short addr))
257291ed5349SWolfram Sang {
257391ed5349SWolfram Sang int i;
257491ed5349SWolfram Sang
257591ed5349SWolfram Sang if (!probe)
257691ed5349SWolfram Sang probe = i2c_default_probe;
257791ed5349SWolfram Sang
257891ed5349SWolfram Sang for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
257991ed5349SWolfram Sang /* Check address validity */
258091ed5349SWolfram Sang if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) {
258191ed5349SWolfram Sang dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n",
258291ed5349SWolfram Sang addr_list[i]);
258391ed5349SWolfram Sang continue;
258491ed5349SWolfram Sang }
258591ed5349SWolfram Sang
258691ed5349SWolfram Sang /* Check address availability (7 bit, no need to encode flags) */
258791ed5349SWolfram Sang if (i2c_check_addr_busy(adap, addr_list[i])) {
258891ed5349SWolfram Sang dev_dbg(&adap->dev,
258991ed5349SWolfram Sang "Address 0x%02x already in use, not probing\n",
259091ed5349SWolfram Sang addr_list[i]);
259191ed5349SWolfram Sang continue;
259291ed5349SWolfram Sang }
259391ed5349SWolfram Sang
259491ed5349SWolfram Sang /* Test address responsiveness */
259591ed5349SWolfram Sang if (probe(adap, addr_list[i]))
259691ed5349SWolfram Sang break;
2597e4c72c06SXu Wang }
2598e4c72c06SXu Wang
259991ed5349SWolfram Sang if (addr_list[i] == I2C_CLIENT_END) {
260091ed5349SWolfram Sang dev_dbg(&adap->dev, "Probing failed, no device found\n");
260191ed5349SWolfram Sang return ERR_PTR(-ENODEV);
2602e94bc5d1SWolfram Sang }
2603e94bc5d1SWolfram Sang
2604e94bc5d1SWolfram Sang info->addr = addr_list[i];
2605bf263c35SWolfram Sang return i2c_new_client_device(adap, info);
2606bf263c35SWolfram Sang }
2607e94bc5d1SWolfram Sang EXPORT_SYMBOL_GPL(i2c_new_scanned_device);
2608e94bc5d1SWolfram Sang
i2c_get_adapter(int nr)2609e94bc5d1SWolfram Sang struct i2c_adapter *i2c_get_adapter(int nr)
261034d1b82cSStephen Boyd {
2611e94bc5d1SWolfram Sang struct i2c_adapter *adapter;
2612e94bc5d1SWolfram Sang
2613e94bc5d1SWolfram Sang mutex_lock(&core_lock);
2614e94bc5d1SWolfram Sang adapter = idr_find(&i2c_adapter_idr, nr);
2615e94bc5d1SWolfram Sang if (!adapter)
2616bf263c35SWolfram Sang goto exit;
2617bf263c35SWolfram Sang
2618bf263c35SWolfram Sang if (try_module_get(adapter->owner))
2619bf263c35SWolfram Sang get_device(&adapter->dev);
2620bf263c35SWolfram Sang else
2621e94bc5d1SWolfram Sang adapter = NULL;
2622e94bc5d1SWolfram Sang
2623e94bc5d1SWolfram Sang exit:
2624e94bc5d1SWolfram Sang mutex_unlock(&core_lock);
2625e94bc5d1SWolfram Sang return adapter;
2626e94bc5d1SWolfram Sang }
2627e94bc5d1SWolfram Sang EXPORT_SYMBOL(i2c_get_adapter);
2628e94bc5d1SWolfram Sang
i2c_put_adapter(struct i2c_adapter * adap)2629e94bc5d1SWolfram Sang void i2c_put_adapter(struct i2c_adapter *adap)
2630e94bc5d1SWolfram Sang {
2631e94bc5d1SWolfram Sang if (!adap)
2632e94bc5d1SWolfram Sang return;
2633e94bc5d1SWolfram Sang
2634e94bc5d1SWolfram Sang module_put(adap->owner);
2635e94bc5d1SWolfram Sang /* Should be last, otherwise we risk use-after-free with 'adap' */
2636e94bc5d1SWolfram Sang put_device(&adap->dev);
263782fe39a6SWolfram Sang }
2638e94bc5d1SWolfram Sang EXPORT_SYMBOL(i2c_put_adapter);
263982fe39a6SWolfram Sang
264082fe39a6SWolfram Sang /**
2641e94bc5d1SWolfram Sang * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg
264282fe39a6SWolfram Sang * @msg: the message to be checked
2643e94bc5d1SWolfram Sang * @threshold: the minimum number of bytes for which using DMA makes sense.
2644e94bc5d1SWolfram Sang * Should at least be 1.
2645e94bc5d1SWolfram Sang *
2646e94bc5d1SWolfram Sang * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO.
264782fe39a6SWolfram Sang * Or a valid pointer to be used with DMA. After use, release it by
2648e94bc5d1SWolfram Sang * calling i2c_put_dma_safe_msg_buf().
2649e94bc5d1SWolfram Sang *
2650e94bc5d1SWolfram Sang * This function must only be called from process context!
2651e94bc5d1SWolfram Sang */
i2c_get_dma_safe_msg_buf(struct i2c_msg * msg,unsigned int threshold)265282fe39a6SWolfram Sang u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold)
2653e94bc5d1SWolfram Sang {
265491ed5349SWolfram Sang /* also skip 0-length msgs for bogus thresholds of 0 */
265591ed5349SWolfram Sang if (!threshold)
265691ed5349SWolfram Sang pr_debug("DMA buffer for addr=0x%02x with length 0 is bogus\n",
2657 msg->addr);
2658 if (msg->len < threshold || msg->len == 0)
2659 return NULL;
2660
2661 if (msg->flags & I2C_M_DMA_SAFE)
2662 return msg->buf;
2663
2664 pr_debug("using bounce buffer for addr=0x%02x, len=%d\n",
2665 msg->addr, msg->len);
2666
2667 if (msg->flags & I2C_M_RD)
2668 return kzalloc(msg->len, GFP_KERNEL);
2669 else
2670 return kmemdup(msg->buf, msg->len, GFP_KERNEL);
2671 }
2672 EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf);
2673
2674 /**
2675 * i2c_put_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg
2676 * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL.
2677 * @msg: the message which the buffer corresponds to
2678 * @xferred: bool saying if the message was transferred
2679 */
i2c_put_dma_safe_msg_buf(u8 * buf,struct i2c_msg * msg,bool xferred)2680 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred)
2681 {
2682 if (!buf || buf == msg->buf)
2683 return;
2684
2685 if (xferred && msg->flags & I2C_M_RD)
2686 memcpy(msg->buf, buf, msg->len);
2687
2688 kfree(buf);
2689 }
2690 EXPORT_SYMBOL_GPL(i2c_put_dma_safe_msg_buf);
2691
2692 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
2693 MODULE_DESCRIPTION("I2C-Bus main module");
2694 MODULE_LICENSE("GPL");
2695