| /* |
| * Linux I2C core |
| * |
| * Copyright (C) 1995-99 Simon G. Vogl |
| * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> |
| * Mux support by Rodolfo Giometti <giometti@enneenne.com> and |
| * Michael Lawnick <michael.lawnick.ext@nsn.com> |
| * |
| * Copyright (C) 2013-2017 Wolfram Sang <wsa@the-dreams.de> |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License as published by the Free |
| * Software Foundation; either version 2 of the License, or (at your option) |
| * any later version. |
| * |
| * This program is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS |
| * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. |
| */ |
| |
| #define pr_fmt(fmt) "i2c-core: " fmt |
| |
| #include <dt-bindings/i2c/i2c.h> |
| #include <linux/acpi.h> |
| #include <linux/clk/clk-conf.h> |
| #include <linux/completion.h> |
| #include <linux/delay.h> |
| #include <linux/err.h> |
| #include <linux/errno.h> |
| #include <linux/gpio/consumer.h> |
| #include <linux/i2c.h> |
| #include <linux/i2c-smbus.h> |
| #include <linux/idr.h> |
| #include <linux/init.h> |
| #include <linux/irqflags.h> |
| #include <linux/jump_label.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| #include <linux/of_device.h> |
| #include <linux/of.h> |
| #include <linux/of_irq.h> |
| #include <linux/pm_domain.h> |
| #include <linux/pm_runtime.h> |
| #include <linux/pm_wakeirq.h> |
| #include <linux/property.h> |
| #include <linux/rwsem.h> |
| #include <linux/slab.h> |
| |
| #include "i2c-core.h" |
| |
| #define CREATE_TRACE_POINTS |
| #include <trace/events/i2c.h> |
| |
| #define I2C_ADDR_OFFSET_TEN_BIT 0xa000 |
| #define I2C_ADDR_OFFSET_SLAVE 0x1000 |
| |
| #define I2C_ADDR_7BITS_MAX 0x77 |
| #define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1) |
| |
| #define I2C_ADDR_DEVICE_ID 0x7c |
| |
| /* |
| * core_lock protects i2c_adapter_idr, and guarantees that device detection, |
| * deletion of detected devices, and attach_adapter calls are serialized |
| */ |
| static DEFINE_MUTEX(core_lock); |
| static DEFINE_IDR(i2c_adapter_idr); |
| |
| static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
| |
| static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key); |
| static bool is_registered; |
| |
| int i2c_transfer_trace_reg(void) |
| { |
| static_branch_inc(&i2c_trace_msg_key); |
| return 0; |
| } |
| |
| void i2c_transfer_trace_unreg(void) |
| { |
| static_branch_dec(&i2c_trace_msg_key); |
| } |
| |
| const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
| const struct i2c_client *client) |
| { |
| if (!(id && client)) |
| return NULL; |
| |
| while (id->name[0]) { |
| if (strcmp(client->name, id->name) == 0) |
| return id; |
| id++; |
| } |
| return NULL; |
| } |
| EXPORT_SYMBOL_GPL(i2c_match_id); |
| |
| static int i2c_device_match(struct device *dev, struct device_driver *drv) |
| { |
| struct i2c_client *client = i2c_verify_client(dev); |
| struct i2c_driver *driver; |
| |
| |
| /* Attempt an OF style match */ |
| if (i2c_of_match_device(drv->of_match_table, client)) |
| return 1; |
| |
| /* Then ACPI style match */ |
| if (acpi_driver_match_device(dev, drv)) |
| return 1; |
| |
| driver = to_i2c_driver(drv); |
| |
| /* Finally an I2C match */ |
| if (i2c_match_id(driver->id_table, client)) |
| return 1; |
| |
| return 0; |
| } |
| |
| static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| int rc; |
| |
| rc = of_device_uevent_modalias(dev, env); |
| if (rc != -ENODEV) |
| return rc; |
| |
| rc = acpi_device_uevent_modalias(dev, env); |
| if (rc != -ENODEV) |
| return rc; |
| |
| return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name); |
| } |
| |
| /* i2c bus recovery routines */ |
| static int get_scl_gpio_value(struct i2c_adapter *adap) |
| { |
| return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod); |
| } |
| |
| static void set_scl_gpio_value(struct i2c_adapter *adap, int val) |
| { |
| gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val); |
| } |
| |
| static int get_sda_gpio_value(struct i2c_adapter *adap) |
| { |
| return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod); |
| } |
| |
| static void set_sda_gpio_value(struct i2c_adapter *adap, int val) |
| { |
| gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val); |
| } |
| |
| /* |
| * We are generating clock pulses. ndelay() determines durating of clk pulses. |
| * We will generate clock with rate 100 KHz and so duration of both clock levels |
| * is: delay in ns = (10^6 / 100) / 2 |
| */ |
| #define RECOVERY_NDELAY 5000 |
| #define RECOVERY_CLK_CNT 9 |
| |
| int i2c_generic_scl_recovery(struct i2c_adapter *adap) |
| { |
| struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; |
| int i = 0, val = 1, ret = 0; |
| |
| if (bri->prepare_recovery) |
| bri->prepare_recovery(adap); |
| |
| bri->set_scl(adap, val); |
| if (bri->set_sda) |
| bri->set_sda(adap, 1); |
| ndelay(RECOVERY_NDELAY); |
| |
| /* |
| * By this time SCL is high, as we need to give 9 falling-rising edges |
| */ |
| while (i++ < RECOVERY_CLK_CNT * 2) { |
| if (val) { |
| /* SCL shouldn't be low here */ |
| if (!bri->get_scl(adap)) { |
| dev_err(&adap->dev, |
| "SCL is stuck low, exit recovery\n"); |
| ret = -EBUSY; |
| break; |
| } |
| /* Break if SDA is high */ |
| if (bri->get_sda && bri->get_sda(adap)) |
| break; |
| } |
| |
| val = !val; |
| bri->set_scl(adap, val); |
| |
| /* |
| * If we can set SDA, we will always create STOP here to ensure |
| * the additional pulses will do no harm. This is achieved by |
| * letting SDA follow SCL half a cycle later. |
| */ |
| ndelay(RECOVERY_NDELAY / 2); |
| if (bri->set_sda) |
| bri->set_sda(adap, val); |
| ndelay(RECOVERY_NDELAY / 2); |
| } |
| |
| /* check if recovery actually succeeded */ |
| if (bri->get_sda && !bri->get_sda(adap)) |
| ret = -EBUSY; |
| |
| /* If all went well, send STOP for a sane bus state. */ |
| if (ret == 0 && bri->set_sda) { |
| bri->set_scl(adap, 0); |
| ndelay(RECOVERY_NDELAY / 2); |
| bri->set_sda(adap, 0); |
| ndelay(RECOVERY_NDELAY / 2); |
| bri->set_scl(adap, 1); |
| ndelay(RECOVERY_NDELAY / 2); |
| bri->set_sda(adap, 1); |
| ndelay(RECOVERY_NDELAY / 2); |
| } |
| |
| if (bri->unprepare_recovery) |
| bri->unprepare_recovery(adap); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery); |
| |
| int i2c_recover_bus(struct i2c_adapter *adap) |
| { |
| if (!adap->bus_recovery_info) |
| return -EOPNOTSUPP; |
| |
| dev_dbg(&adap->dev, "Trying i2c bus recovery\n"); |
| return adap->bus_recovery_info->recover_bus(adap); |
| } |
| EXPORT_SYMBOL_GPL(i2c_recover_bus); |
| |
| static void i2c_init_recovery(struct i2c_adapter *adap) |
| { |
| struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; |
| char *err_str; |
| |
| if (!bri) |
| return; |
| |
| if (!bri->recover_bus) { |
| err_str = "no recover_bus() found"; |
| goto err; |
| } |
| |
| if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) { |
| bri->get_scl = get_scl_gpio_value; |
| bri->set_scl = set_scl_gpio_value; |
| if (bri->sda_gpiod) { |
| bri->get_sda = get_sda_gpio_value; |
| /* FIXME: add proper flag instead of '0' once available */ |
| if (gpiod_get_direction(bri->sda_gpiod) == 0) |
| bri->set_sda = set_sda_gpio_value; |
| } |
| return; |
| } |
| |
| if (bri->recover_bus == i2c_generic_scl_recovery) { |
| /* Generic SCL recovery */ |
| if (!bri->set_scl || !bri->get_scl) { |
| err_str = "no {get|set}_scl() found"; |
| goto err; |
| } |
| } |
| |
| return; |
| err: |
| dev_err(&adap->dev, "Not using recovery: %s\n", err_str); |
| adap->bus_recovery_info = NULL; |
| } |
| |
| static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client) |
| { |
| struct i2c_adapter *adap = client->adapter; |
| unsigned int irq; |
| |
| if (!adap->host_notify_domain) |
| return -ENXIO; |
| |
| if (client->flags & I2C_CLIENT_TEN) |
| return -EINVAL; |
| |
| irq = irq_find_mapping(adap->host_notify_domain, client->addr); |
| if (!irq) |
| irq = irq_create_mapping(adap->host_notify_domain, |
| client->addr); |
| |
| return irq > 0 ? irq : -ENXIO; |
| } |
| |
| static int i2c_device_probe(struct device *dev) |
| { |
| struct i2c_client *client = i2c_verify_client(dev); |
| struct i2c_driver *driver; |
| int status; |
| |
| if (!client) |
| return 0; |
| |
| driver = to_i2c_driver(dev->driver); |
| |
| if (!client->irq && !driver->disable_i2c_core_irq_mapping) { |
| int irq = -ENOENT; |
| |
| if (client->flags & I2C_CLIENT_HOST_NOTIFY) { |
| dev_dbg(dev, "Using Host Notify IRQ\n"); |
| irq = i2c_smbus_host_notify_to_irq(client); |
| } else if (dev->of_node) { |
| irq = of_irq_get_byname(dev->of_node, "irq"); |
| if (irq == -EINVAL || irq == -ENODATA) |
| irq = of_irq_get(dev->of_node, 0); |
| } else if (ACPI_COMPANION(dev)) { |
| irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0); |
| } |
| if (irq == -EPROBE_DEFER) |
| return irq; |
| |
| if (irq < 0) |
| irq = 0; |
| |
| client->irq = irq; |
| } |
| |
| /* |
| * An I2C ID table is not mandatory, if and only if, a suitable OF |
| * or ACPI ID table is supplied for the probing device. |
| */ |
| if (!driver->id_table && |
| !i2c_acpi_match_device(dev->driver->acpi_match_table, client) && |
| !i2c_of_match_device(dev->driver->of_match_table, client)) |
| return -ENODEV; |
| |
| if (client->flags & I2C_CLIENT_WAKE) { |
| int wakeirq = -ENOENT; |
| |
| if (dev->of_node) { |
| wakeirq = of_irq_get_byname(dev->of_node, "wakeup"); |
| if (wakeirq == -EPROBE_DEFER) |
| return wakeirq; |
| } |
| |
| device_init_wakeup(&client->dev, true); |
| |
| if (wakeirq > 0 && wakeirq != client->irq) |
| status = dev_pm_set_dedicated_wake_irq(dev, wakeirq); |
| else if (client->irq > 0) |
| status = dev_pm_set_wake_irq(dev, client->irq); |
| else |
| status = 0; |
| |
| if (status) |
| dev_warn(&client->dev, "failed to set up wakeup irq\n"); |
| } |
| |
| dev_dbg(dev, "probe\n"); |
| |
| status = of_clk_set_defaults(dev->of_node, false); |
| if (status < 0) |
| goto err_clear_wakeup_irq; |
| |
| status = dev_pm_domain_attach(&client->dev, true); |
| if (status == -EPROBE_DEFER) |
| goto err_clear_wakeup_irq; |
| |
| /* |
| * When there are no more users of probe(), |
| * rename probe_new to probe. |
| */ |
| if (driver->probe_new) |
| status = driver->probe_new(client); |
| else if (driver->probe) |
| status = driver->probe(client, |
| i2c_match_id(driver->id_table, client)); |
| else |
| status = -EINVAL; |
| |
| if (status) |
| goto err_detach_pm_domain; |
| |
| return 0; |
| |
| err_detach_pm_domain: |
| dev_pm_domain_detach(&client->dev, true); |
| err_clear_wakeup_irq: |
| dev_pm_clear_wake_irq(&client->dev); |
| device_init_wakeup(&client->dev, false); |
| return status; |
| } |
| |
| static int i2c_device_remove(struct device *dev) |
| { |
| struct i2c_client *client = i2c_verify_client(dev); |
| struct i2c_driver *driver; |
| int status = 0; |
| |
| if (!client || !dev->driver) |
| return 0; |
| |
| driver = to_i2c_driver(dev->driver); |
| if (driver->remove) { |
| dev_dbg(dev, "remove\n"); |
| status = driver->remove(client); |
| } |
| |
| dev_pm_domain_detach(&client->dev, true); |
| |
| dev_pm_clear_wake_irq(&client->dev); |
| device_init_wakeup(&client->dev, false); |
| |
| return status; |
| } |
| |
| static void i2c_device_shutdown(struct device *dev) |
| { |
| struct i2c_client *client = i2c_verify_client(dev); |
| struct i2c_driver *driver; |
| |
| if (!client || !dev->driver) |
| return; |
| driver = to_i2c_driver(dev->driver); |
| if (driver->shutdown) |
| driver->shutdown(client); |
| } |
| |
| static void i2c_client_dev_release(struct device *dev) |
| { |
| kfree(to_i2c_client(dev)); |
| } |
| |
| static ssize_t |
| show_name(struct device *dev, struct device_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
| to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); |
| } |
| static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
| |
| static ssize_t |
| show_modalias(struct device *dev, struct device_attribute *attr, char *buf) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| int len; |
| |
| len = of_device_modalias(dev, buf, PAGE_SIZE); |
| if (len != -ENODEV) |
| return len; |
| |
| len = acpi_device_modalias(dev, buf, PAGE_SIZE -1); |
| if (len != -ENODEV) |
| return len; |
| |
| return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
| } |
| static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
| |
| static struct attribute *i2c_dev_attrs[] = { |
| &dev_attr_name.attr, |
| /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
| &dev_attr_modalias.attr, |
| NULL |
| }; |
| ATTRIBUTE_GROUPS(i2c_dev); |
| |
| struct bus_type i2c_bus_type = { |
| .name = "i2c", |
| .match = i2c_device_match, |
| .probe = i2c_device_probe, |
| .remove = i2c_device_remove, |
| .shutdown = i2c_device_shutdown, |
| }; |
| EXPORT_SYMBOL_GPL(i2c_bus_type); |
| |
| struct device_type i2c_client_type = { |
| .groups = i2c_dev_groups, |
| .uevent = i2c_device_uevent, |
| .release = i2c_client_dev_release, |
| }; |
| EXPORT_SYMBOL_GPL(i2c_client_type); |
| |
| |
| /** |
| * i2c_verify_client - return parameter as i2c_client, or NULL |
| * @dev: device, probably from some driver model iterator |
| * |
| * When traversing the driver model tree, perhaps using driver model |
| * iterators like @device_for_each_child(), you can't assume very much |
| * about the nodes you find. Use this function to avoid oopses caused |
| * by wrongly treating some non-I2C device as an i2c_client. |
| */ |
| struct i2c_client *i2c_verify_client(struct device *dev) |
| { |
| return (dev->type == &i2c_client_type) |
| ? to_i2c_client(dev) |
| : NULL; |
| } |
| EXPORT_SYMBOL(i2c_verify_client); |
| |
| |
| /* Return a unique address which takes the flags of the client into account */ |
| static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client) |
| { |
| unsigned short addr = client->addr; |
| |
| /* For some client flags, add an arbitrary offset to avoid collisions */ |
| if (client->flags & I2C_CLIENT_TEN) |
| addr |= I2C_ADDR_OFFSET_TEN_BIT; |
| |
| if (client->flags & I2C_CLIENT_SLAVE) |
| addr |= I2C_ADDR_OFFSET_SLAVE; |
| |
| return addr; |
| } |
| |
| /* This is a permissive address validity check, I2C address map constraints |
| * are purposely not enforced, except for the general call address. */ |
| static int i2c_check_addr_validity(unsigned int addr, unsigned short flags) |
| { |
| if (flags & I2C_CLIENT_TEN) { |
| /* 10-bit address, all values are valid */ |
| if (addr > 0x3ff) |
| return -EINVAL; |
| } else { |
| /* 7-bit address, reject the general call address */ |
| if (addr == 0x00 || addr > 0x7f) |
| return -EINVAL; |
| } |
| return 0; |
| } |
| |
| /* And this is a strict address validity check, used when probing. If a |
| * device uses a reserved address, then it shouldn't be probed. 7-bit |
| * addressing is assumed, 10-bit address devices are rare and should be |
| * explicitly enumerated. */ |
| int i2c_check_7bit_addr_validity_strict(unsigned short addr) |
| { |
| /* |
| * Reserved addresses per I2C specification: |
| * 0x00 General call address / START byte |
| * 0x01 CBUS address |
| * 0x02 Reserved for different bus format |
| * 0x03 Reserved for future purposes |
| * 0x04-0x07 Hs-mode master code |
| * 0x78-0x7b 10-bit slave addressing |
| * 0x7c-0x7f Reserved for future purposes |
| */ |
| if (addr < 0x08 || addr > 0x77) |
| return -EINVAL; |
| return 0; |
| } |
| |
| static int __i2c_check_addr_busy(struct device *dev, void *addrp) |
| { |
| struct i2c_client *client = i2c_verify_client(dev); |
| int addr = *(int *)addrp; |
| |
| if (client && i2c_encode_flags_to_addr(client) == addr) |
| return -EBUSY; |
| return 0; |
| } |
| |
| /* walk up mux tree */ |
| static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) |
| { |
| struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
| int result; |
| |
| result = device_for_each_child(&adapter->dev, &addr, |
| __i2c_check_addr_busy); |
| |
| if (!result && parent) |
| result = i2c_check_mux_parents(parent, addr); |
| |
| return result; |
| } |
| |
| /* recurse down mux tree */ |
| static int i2c_check_mux_children(struct device *dev, void *addrp) |
| { |
| int result; |
| |
| if (dev->type == &i2c_adapter_type) |
| result = device_for_each_child(dev, addrp, |
| i2c_check_mux_children); |
| else |
| result = __i2c_check_addr_busy(dev, addrp); |
| |
| return result; |
| } |
| |
| static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) |
| { |
| struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
| int result = 0; |
| |
| if (parent) |
| result = i2c_check_mux_parents(parent, addr); |
| |
| if (!result) |
| result = device_for_each_child(&adapter->dev, &addr, |
| i2c_check_mux_children); |
| |
| return result; |
| } |
| |
| /** |
| * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment |
| * @adapter: Target I2C bus segment |
| * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT |
| * locks only this branch in the adapter tree |
| */ |
| static void i2c_adapter_lock_bus(struct i2c_adapter *adapter, |
| unsigned int flags) |
| { |
| rt_mutex_lock(&adapter->bus_lock); |
| } |
| |
| /** |
| * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment |
| * @adapter: Target I2C bus segment |
| * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT |
| * trylocks only this branch in the adapter tree |
| */ |
| static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter, |
| unsigned int flags) |
| { |
| return rt_mutex_trylock(&adapter->bus_lock); |
| } |
| |
| /** |
| * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment |
| * @adapter: Target I2C bus segment |
| * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT |
| * unlocks only this branch in the adapter tree |
| */ |
| static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter, |
| unsigned int flags) |
| { |
| rt_mutex_unlock(&adapter->bus_lock); |
| } |
| |
| static void i2c_dev_set_name(struct i2c_adapter *adap, |
| struct i2c_client *client, |
| struct i2c_board_info const *info) |
| { |
| struct acpi_device *adev = ACPI_COMPANION(&client->dev); |
| |
| if (info && info->dev_name) { |
| dev_set_name(&client->dev, "i2c-%s", info->dev_name); |
| return; |
| } |
| |
| if (adev) { |
| dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); |
| return; |
| } |
| |
| dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), |
| i2c_encode_flags_to_addr(client)); |
| } |
| |
| static int i2c_dev_irq_from_resources(const struct resource *resources, |
| unsigned int num_resources) |
| { |
| struct irq_data *irqd; |
| int i; |
| |
| for (i = 0; i < num_resources; i++) { |
| const struct resource *r = &resources[i]; |
| |
| if (resource_type(r) != IORESOURCE_IRQ) |
| continue; |
| |
| if (r->flags & IORESOURCE_BITS) { |
| irqd = irq_get_irq_data(r->start); |
| if (!irqd) |
| break; |
| |
| irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); |
| } |
| |
| return r->start; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * i2c_new_device - instantiate an i2c device |
| * @adap: the adapter managing the device |
| * @info: describes one I2C device; bus_num is ignored |
| * Context: can sleep |
| * |
| * Create an i2c device. Binding is handled through driver model |
| * probe()/remove() methods. A driver may be bound to this device when we |
| * return from this function, or any later moment (e.g. maybe hotplugging will |
| * load the driver module). This call is not appropriate for use by mainboard |
| * initialization logic, which usually runs during an arch_initcall() long |
| * before any i2c_adapter could exist. |
| * |
| * This returns the new i2c client, which may be saved for later use with |
| * i2c_unregister_device(); or NULL to indicate an error. |
| */ |
| struct i2c_client * |
| i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) |
| { |
| struct i2c_client *client; |
| int status; |
| |
| client = kzalloc(sizeof *client, GFP_KERNEL); |
| if (!client) |
| return NULL; |
| |
| client->adapter = adap; |
| |
| client->dev.platform_data = info->platform_data; |
| |
| if (info->archdata) |
| client->dev.archdata = *info->archdata; |
| |
| client->flags = info->flags; |
| client->addr = info->addr; |
| |
| client->irq = info->irq; |
| if (!client->irq) |
| client->irq = i2c_dev_irq_from_resources(info->resources, |
| info->num_resources); |
| |
| strlcpy(client->name, info->type, sizeof(client->name)); |
| |
| status = i2c_check_addr_validity(client->addr, client->flags); |
| if (status) { |
| dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", |
| client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); |
| goto out_err_silent; |
| } |
| |
| /* Check for address business */ |
| status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client)); |
| if (status) |
| goto out_err; |
| |
| client->dev.parent = &client->adapter->dev; |
| client->dev.bus = &i2c_bus_type; |
| client->dev.type = &i2c_client_type; |
| client->dev.of_node = info->of_node; |
| client->dev.fwnode = info->fwnode; |
| |
| i2c_dev_set_name(adap, client, info); |
| |
| if (info->properties) { |
| status = device_add_properties(&client->dev, info->properties); |
| if (status) { |
| dev_err(&adap->dev, |
| "Failed to add properties to client %s: %d\n", |
| client->name, status); |
| goto out_err; |
| } |
| } |
| |
| status = device_register(&client->dev); |
| if (status) |
| goto out_free_props; |
| |
| dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
| client->name, dev_name(&client->dev)); |
| |
| return client; |
| |
| out_free_props: |
| if (info->properties) |
| device_remove_properties(&client->dev); |
| out_err: |
| dev_err(&adap->dev, |
| "Failed to register i2c client %s at 0x%02x (%d)\n", |
| client->name, client->addr, status); |
| out_err_silent: |
| kfree(client); |
| return NULL; |
| } |
| EXPORT_SYMBOL_GPL(i2c_new_device); |
| |
| |
| /** |
| * i2c_unregister_device - reverse effect of i2c_new_device() |
| * @client: value returned from i2c_new_device() |
| * Context: can sleep |
| */ |
| void i2c_unregister_device(struct i2c_client *client) |
| { |
| if (!client) |
| return; |
| |
| if (client->dev.of_node) { |
| of_node_clear_flag(client->dev.of_node, OF_POPULATED); |
| of_node_put(client->dev.of_node); |
| } |
| |
| if (ACPI_COMPANION(&client->dev)) |
| acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev)); |
| device_unregister(&client->dev); |
| } |
| EXPORT_SYMBOL_GPL(i2c_unregister_device); |
| |
| |
| static const struct i2c_device_id dummy_id[] = { |
| { "dummy", 0 }, |
| { }, |
| }; |
| |
| static int dummy_probe(struct i2c_client *client, |
| const struct i2c_device_id *id) |
| { |
| return 0; |
| } |
| |
| static int dummy_remove(struct i2c_client *client) |
| { |
| return 0; |
| } |
| |
| static struct i2c_driver dummy_driver = { |
| .driver.name = "dummy", |
| .probe = dummy_probe, |
| .remove = dummy_remove, |
| .id_table = dummy_id, |
| }; |
| |
| /** |
| * i2c_new_dummy - return a new i2c device bound to a dummy driver |
| * @adapter: the adapter managing the device |
| * @address: seven bit address to be used |
| * Context: can sleep |
| * |
| * This returns an I2C client bound to the "dummy" driver, intended for use |
| * with devices that consume multiple addresses. Examples of such chips |
| * include various EEPROMS (like 24c04 and 24c08 models). |
| * |
| * These dummy devices have two main uses. First, most I2C and SMBus calls |
| * except i2c_transfer() need a client handle; the dummy will be that handle. |
| * And second, this prevents the specified address from being bound to a |
| * different driver. |
| * |
| * This returns the new i2c client, which should be saved for later use with |
| * i2c_unregister_device(); or NULL to indicate an error. |
| */ |
| struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
| { |
| struct i2c_board_info info = { |
| I2C_BOARD_INFO("dummy", address), |
| }; |
| |
| return i2c_new_device(adapter, &info); |
| } |
| EXPORT_SYMBOL_GPL(i2c_new_dummy); |
| |
| /** |
| * i2c_new_secondary_device - Helper to get the instantiated secondary address |
| * and create the associated device |
| * @client: Handle to the primary client |
| * @name: Handle to specify which secondary address to get |
| * @default_addr: Used as a fallback if no secondary address was specified |
| * Context: can sleep |
| * |
| * I2C clients can be composed of multiple I2C slaves bound together in a single |
| * component. The I2C client driver then binds to the master I2C slave and needs |
| * to create I2C dummy clients to communicate with all the other slaves. |
| * |
| * This function creates and returns an I2C dummy client whose I2C address is |
| * retrieved from the platform firmware based on the given slave name. If no |
| * address is specified by the firmware default_addr is used. |
| * |
| * On DT-based platforms the address is retrieved from the "reg" property entry |
| * cell whose "reg-names" value matches the slave name. |
| * |
| * This returns the new i2c client, which should be saved for later use with |
| * i2c_unregister_device(); or NULL to indicate an error. |
| */ |
| struct i2c_client *i2c_new_secondary_device(struct i2c_client *client, |
| const char *name, |
| u16 default_addr) |
| { |
| struct device_node *np = client->dev.of_node; |
| u32 addr = default_addr; |
| int i; |
| |
| if (np) { |
| i = of_property_match_string(np, "reg-names", name); |
| if (i >= 0) |
| of_property_read_u32_index(np, "reg", i, &addr); |
| } |
| |
| dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr); |
| return i2c_new_dummy(client->adapter, addr); |
| } |
| EXPORT_SYMBOL_GPL(i2c_new_secondary_device); |
| |
| /* ------------------------------------------------------------------------- */ |
| |
| /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
| |
| static void i2c_adapter_dev_release(struct device *dev) |
| { |
| struct i2c_adapter *adap = to_i2c_adapter(dev); |
| complete(&adap->dev_released); |
| } |
| |
| unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) |
| { |
| unsigned int depth = 0; |
| |
| while ((adapter = i2c_parent_is_i2c_adapter(adapter))) |
| depth++; |
| |
| WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES, |
| "adapter depth exceeds lockdep subclass limit\n"); |
| |
| return depth; |
| } |
| EXPORT_SYMBOL_GPL(i2c_adapter_depth); |
| |
| /* |
| * Let users instantiate I2C devices through sysfs. This can be used when |
| * platform initialization code doesn't contain the proper data for |
| * whatever reason. Also useful for drivers that do device detection and |
| * detection fails, either because the device uses an unexpected address, |
| * or this is a compatible device with different ID register values. |
| * |
| * Parameter checking may look overzealous, but we really don't want |
| * the user to provide incorrect parameters. |
| */ |
| static ssize_t |
| i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, |
| const char *buf, size_t count) |
| { |
| struct i2c_adapter *adap = to_i2c_adapter(dev); |
| struct i2c_board_info info; |
| struct i2c_client *client; |
| char *blank, end; |
| int res; |
| |
| memset(&info, 0, sizeof(struct i2c_board_info)); |
| |
| blank = strchr(buf, ' '); |
| if (!blank) { |
| dev_err(dev, "%s: Missing parameters\n", "new_device"); |
| return -EINVAL; |
| } |
| if (blank - buf > I2C_NAME_SIZE - 1) { |
| dev_err(dev, "%s: Invalid device name\n", "new_device"); |
| return -EINVAL; |
| } |
| memcpy(info.type, buf, blank - buf); |
| |
| /* Parse remaining parameters, reject extra parameters */ |
| res = sscanf(++blank, "%hi%c", &info.addr, &end); |
| if (res < 1) { |
| dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); |
| return -EINVAL; |
| } |
| if (res > 1 && end != '\n') { |
| dev_err(dev, "%s: Extra parameters\n", "new_device"); |
| return -EINVAL; |
| } |
| |
| if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) { |
| info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT; |
| info.flags |= I2C_CLIENT_TEN; |
| } |
| |
| if (info.addr & I2C_ADDR_OFFSET_SLAVE) { |
| info.addr &= ~I2C_ADDR_OFFSET_SLAVE; |
| info.flags |= I2C_CLIENT_SLAVE; |
| } |
| |
| client = i2c_new_device(adap, &info); |
| if (!client) |
| return -EINVAL; |
| |
| /* Keep track of the added device */ |
| mutex_lock(&adap->userspace_clients_lock); |
| list_add_tail(&client->detected, &adap->userspace_clients); |
| mutex_unlock(&adap->userspace_clients_lock); |
| dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
| info.type, info.addr); |
| |
| return count; |
| } |
| static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
| |
| /* |
| * And of course let the users delete the devices they instantiated, if |
| * they got it wrong. This interface can only be used to delete devices |
| * instantiated by i2c_sysfs_new_device above. This guarantees that we |
| * don't delete devices to which some kernel code still has references. |
| * |
| * Parameter checking may look overzealous, but we really don't want |
| * the user to delete the wrong device. |
| */ |
| static ssize_t |
| i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, |
| const char *buf, size_t count) |
| { |
| struct i2c_adapter *adap = to_i2c_adapter(dev); |
| struct i2c_client *client, *next; |
| unsigned short addr; |
| char end; |
| int res; |
| |
| /* Parse parameters, reject extra parameters */ |
| res = sscanf(buf, "%hi%c", &addr, &end); |
| if (res < 1) { |
| dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); |
| return -EINVAL; |
| } |
| if (res > 1 && end != '\n') { |
| dev_err(dev, "%s: Extra parameters\n", "delete_device"); |
| return -EINVAL; |
| } |
| |
| /* Make sure the device was added through sysfs */ |
| res = -ENOENT; |
| mutex_lock_nested(&adap->userspace_clients_lock, |
| i2c_adapter_depth(adap)); |
| list_for_each_entry_safe(client, next, &adap->userspace_clients, |
| detected) { |
| if (i2c_encode_flags_to_addr(client) == addr) { |
| dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
| "delete_device", client->name, client->addr); |
| |
| list_del(&client->detected); |
| i2c_unregister_device(client); |
| res = count; |
| break; |
| } |
| } |
| mutex_unlock(&adap->userspace_clients_lock); |
| |
| if (res < 0) |
| dev_err(dev, "%s: Can't find device in list\n", |
| "delete_device"); |
| return res; |
| } |
| static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, |
| i2c_sysfs_delete_device); |
| |
| static struct attribute *i2c_adapter_attrs[] = { |
| &dev_attr_name.attr, |
| &dev_attr_new_device.attr, |
| &dev_attr_delete_device.attr, |
| NULL |
| }; |
| ATTRIBUTE_GROUPS(i2c_adapter); |
| |
| struct device_type i2c_adapter_type = { |
| .groups = i2c_adapter_groups, |
| .release = i2c_adapter_dev_release, |
| }; |
| EXPORT_SYMBOL_GPL(i2c_adapter_type); |
| |
| /** |
| * i2c_verify_adapter - return parameter as i2c_adapter or NULL |
| * @dev: device, probably from some driver model iterator |
| * |
| * When traversing the driver model tree, perhaps using driver model |
| * iterators like @device_for_each_child(), you can't assume very much |
| * about the nodes you find. Use this function to avoid oopses caused |
| * by wrongly treating some non-I2C device as an i2c_adapter. |
| */ |
| struct i2c_adapter *i2c_verify_adapter(struct device *dev) |
| { |
| return (dev->type == &i2c_adapter_type) |
| ? to_i2c_adapter(dev) |
| : NULL; |
| } |
| EXPORT_SYMBOL(i2c_verify_adapter); |
| |
| #ifdef CONFIG_I2C_COMPAT |
| static struct class_compat *i2c_adapter_compat_class; |
| #endif |
| |
| static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
| { |
| struct i2c_devinfo *devinfo; |
| |
| down_read(&__i2c_board_lock); |
| list_for_each_entry(devinfo, &__i2c_board_list, list) { |
| if (devinfo->busnum == adapter->nr |
| && !i2c_new_device(adapter, |
| &devinfo->board_info)) |
| dev_err(&adapter->dev, |
| "Can't create device at 0x%02x\n", |
| devinfo->board_info.addr); |
| } |
| up_read(&__i2c_board_lock); |
| } |
| |
| static int i2c_do_add_adapter(struct i2c_driver *driver, |
| struct i2c_adapter *adap) |
| { |
| /* Detect supported devices on that bus, and instantiate them */ |
| i2c_detect(adap, driver); |
| |
| /* Let legacy drivers scan this bus for matching devices */ |
| if (driver->attach_adapter) { |
| dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n", |
| driver->driver.name); |
| dev_warn(&adap->dev, |
| "Please use another way to instantiate your i2c_client\n"); |
| /* We ignore the return code; if it fails, too bad */ |
| driver->attach_adapter(adap); |
| } |
| return 0; |
| } |
| |
| static int __process_new_adapter(struct device_driver *d, void *data) |
| { |
| return i2c_do_add_adapter(to_i2c_driver(d), data); |
| } |
| |
| static const struct i2c_lock_operations i2c_adapter_lock_ops = { |
| .lock_bus = i2c_adapter_lock_bus, |
| .trylock_bus = i2c_adapter_trylock_bus, |
| .unlock_bus = i2c_adapter_unlock_bus, |
| }; |
| |
| static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap) |
| { |
| struct irq_domain *domain = adap->host_notify_domain; |
| irq_hw_number_t hwirq; |
| |
| if (!domain) |
| return; |
| |
| for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++) |
| irq_dispose_mapping(irq_find_mapping(domain, hwirq)); |
| |
| irq_domain_remove(domain); |
| adap->host_notify_domain = NULL; |
| } |
| |
| static int i2c_host_notify_irq_map(struct irq_domain *h, |
| unsigned int virq, |
| irq_hw_number_t hw_irq_num) |
| { |
| irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq); |
| |
| return 0; |
| } |
| |
| static const struct irq_domain_ops i2c_host_notify_irq_ops = { |
| .map = i2c_host_notify_irq_map, |
| }; |
| |
| static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap) |
| { |
| struct irq_domain *domain; |
| |
| if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY)) |
| return 0; |
| |
| domain = irq_domain_create_linear(adap->dev.fwnode, |
| I2C_ADDR_7BITS_COUNT, |
| &i2c_host_notify_irq_ops, adap); |
| if (!domain) |
| return -ENOMEM; |
| |
| adap->host_notify_domain = domain; |
| |
| return 0; |
| } |
| |
| /** |
| * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct |
| * I2C client. |
| * @adap: the adapter |
| * @addr: the I2C address of the notifying device |
| * Context: can't sleep |
| * |
| * Helper function to be called from an I2C bus driver's interrupt |
| * handler. It will schedule the Host Notify IRQ. |
| */ |
| int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr) |
| { |
| int irq; |
| |
| if (!adap) |
| return -EINVAL; |
| |
| irq = irq_find_mapping(adap->host_notify_domain, addr); |
| if (irq <= 0) |
| return -ENXIO; |
| |
| generic_handle_irq(irq); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify); |
| |
| static int i2c_register_adapter(struct i2c_adapter *adap) |
| { |
| int res = -EINVAL; |
| |
| /* Can't register until after driver model init */ |
| if (WARN_ON(!is_registered)) { |
| res = -EAGAIN; |
| goto out_list; |
| } |
| |
| /* Sanity checks */ |
| if (WARN(!adap->name[0], "i2c adapter has no name")) |
| goto out_list; |
| |
| if (!adap->algo) { |
| pr_err("adapter '%s': no algo supplied!\n", adap->name); |
| goto out_list; |
| } |
| |
| if (!adap->lock_ops) |
| adap->lock_ops = &i2c_adapter_lock_ops; |
| |
| rt_mutex_init(&adap->bus_lock); |
| rt_mutex_init(&adap->mux_lock); |
| mutex_init(&adap->userspace_clients_lock); |
| INIT_LIST_HEAD(&adap->userspace_clients); |
| |
| /* Set default timeout to 1 second if not already set */ |
| if (adap->timeout == 0) |
| adap->timeout = HZ; |
| |
| /* register soft irqs for Host Notify */ |
| res = i2c_setup_host_notify_irq_domain(adap); |
| if (res) { |
| pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n", |
| adap->name, res); |
| goto out_list; |
| } |
| |
| dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
| adap->dev.bus = &i2c_bus_type; |
| adap->dev.type = &i2c_adapter_type; |
| res = device_register(&adap->dev); |
| if (res) { |
| pr_err("adapter '%s': can't register device (%d)\n", adap->name, res); |
| goto out_list; |
| } |
| |
| res = of_i2c_setup_smbus_alert(adap); |
| if (res) |
| goto out_reg; |
| |
| dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
| |
| pm_runtime_no_callbacks(&adap->dev); |
| pm_suspend_ignore_children(&adap->dev, true); |
| pm_runtime_enable(&adap->dev); |
| |
| #ifdef CONFIG_I2C_COMPAT |
| res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, |
| adap->dev.parent); |
| if (res) |
| dev_warn(&adap->dev, |
| "Failed to create compatibility class link\n"); |
| #endif |
| |
| i2c_init_recovery(adap); |
| |
| /* create pre-declared device nodes */ |
| of_i2c_register_devices(adap); |
| i2c_acpi_register_devices(adap); |
| i2c_acpi_install_space_handler(adap); |
| |
| if (adap->nr < __i2c_first_dynamic_bus_num) |
| i2c_scan_static_board_info(adap); |
| |
| /* Notify drivers */ |
| mutex_lock(&core_lock); |
| bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); |
| mutex_unlock(&core_lock); |
| |
| return 0; |
| |
| out_reg: |
| init_completion(&adap->dev_released); |
| device_unregister(&adap->dev); |
| wait_for_completion(&adap->dev_released); |
| out_list: |
| mutex_lock(&core_lock); |
| idr_remove(&i2c_adapter_idr, adap->nr); |
| mutex_unlock(&core_lock); |
| return res; |
| } |
| |
| /** |
| * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 |
| * @adap: the adapter to register (with adap->nr initialized) |
| * Context: can sleep |
| * |
| * See i2c_add_numbered_adapter() for details. |
| */ |
| static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) |
| { |
| int id; |
| |
| mutex_lock(&core_lock); |
| id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL); |
| mutex_unlock(&core_lock); |
| if (WARN(id < 0, "couldn't get idr")) |
| return id == -ENOSPC ? -EBUSY : id; |
| |
| return i2c_register_adapter(adap); |
| } |
| |
| /** |
| * i2c_add_adapter - declare i2c adapter, use dynamic bus number |
| * @adapter: the adapter to add |
| * Context: can sleep |
| * |
| * This routine is used to declare an I2C adapter when its bus number |
| * doesn't matter or when its bus number is specified by an dt alias. |
| * Examples of bases when the bus number doesn't matter: I2C adapters |
| * dynamically added by USB links or PCI plugin cards. |
| * |
| * When this returns zero, a new bus number was allocated and stored |
| * in adap->nr, and the specified adapter became available for clients. |
| * Otherwise, a negative errno value is returned. |
| */ |
| int i2c_add_adapter(struct i2c_adapter *adapter) |
| { |
| struct device *dev = &adapter->dev; |
| int id; |
| |
| if (dev->of_node) { |
| id = of_alias_get_id(dev->of_node, "i2c"); |
| if (id >= 0) { |
| adapter->nr = id; |
| return __i2c_add_numbered_adapter(adapter); |
| } |
| } |
| |
| mutex_lock(&core_lock); |
| id = idr_alloc(&i2c_adapter_idr, adapter, |
| __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); |
| mutex_unlock(&core_lock); |
| if (WARN(id < 0, "couldn't get idr")) |
| return id; |
| |
| adapter->nr = id; |
| |
| return i2c_register_adapter(adapter); |
| } |
| EXPORT_SYMBOL(i2c_add_adapter); |
| |
| /** |
| * i2c_add_numbered_adapter - declare i2c adapter, use static bus number |
| * @adap: the adapter to register (with adap->nr initialized) |
| * Context: can sleep |
| * |
| * This routine is used to declare an I2C adapter when its bus number |
| * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
| * or otherwise built in to the system's mainboard, and where i2c_board_info |
| * is used to properly configure I2C devices. |
| * |
| * If the requested bus number is set to -1, then this function will behave |
| * identically to i2c_add_adapter, and will dynamically assign a bus number. |
| * |
| * If no devices have pre-been declared for this bus, then be sure to |
| * register the adapter before any dynamically allocated ones. Otherwise |
| * the required bus ID may not be available. |
| * |
| * When this returns zero, the specified adapter became available for |
| * clients using the bus number provided in adap->nr. Also, the table |
| * of I2C devices pre-declared using i2c_register_board_info() is scanned, |
| * and the appropriate driver model device nodes are created. Otherwise, a |
| * negative errno value is returned. |
| */ |
| int i2c_add_numbered_adapter(struct i2c_adapter *adap) |
| { |
| if (adap->nr == -1) /* -1 means dynamically assign bus id */ |
| return i2c_add_adapter(adap); |
| |
| return __i2c_add_numbered_adapter(adap); |
| } |
| EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); |
| |
| static void i2c_do_del_adapter(struct i2c_driver *driver, |
| struct i2c_adapter *adapter) |
| { |
| struct i2c_client *client, *_n; |
| |
| /* Remove the devices we created ourselves as the result of hardware |
| * probing (using a driver's detect method) */ |
| list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
| if (client->adapter == adapter) { |
| dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", |
| client->name, client->addr); |
| list_del(&client->detected); |
| i2c_unregister_device(client); |
| } |
| } |
| } |
| |
| static int __unregister_client(struct device *dev, void *dummy) |
| { |
| struct i2c_client *client = i2c_verify_client(dev); |
| if (client && strcmp(client->name, "dummy")) |
| i2c_unregister_device(client); |
| return 0; |
| } |
| |
| static int __unregister_dummy(struct device *dev, void *dummy) |
| { |
| struct i2c_client *client = i2c_verify_client(dev); |
| i2c_unregister_device(client); |
| return 0; |
| } |
| |
| static int __process_removed_adapter(struct device_driver *d, void *data) |
| { |
| i2c_do_del_adapter(to_i2c_driver(d), data); |
| return 0; |
| } |
| |
| /** |
| * i2c_del_adapter - unregister I2C adapter |
| * @adap: the adapter being unregistered |
| * Context: can sleep |
| * |
| * This unregisters an I2C adapter which was previously registered |
| * by @i2c_add_adapter or @i2c_add_numbered_adapter. |
| */ |
| void i2c_del_adapter(struct i2c_adapter *adap) |
| { |
| struct i2c_adapter *found; |
| struct i2c_client *client, *next; |
| |
| /* First make sure that this adapter was ever added */ |
| mutex_lock(&core_lock); |
| found = idr_find(&i2c_adapter_idr, adap->nr); |
| mutex_unlock(&core_lock); |
| if (found != adap) { |
| pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name); |
| return; |
| } |
| |
| i2c_acpi_remove_space_handler(adap); |
| /* Tell drivers about this removal */ |
| mutex_lock(&core_lock); |
| bus_for_each_drv(&i2c_bus_type, NULL, adap, |
| __process_removed_adapter); |
| mutex_unlock(&core_lock); |
| |
| /* Remove devices instantiated from sysfs */ |
| mutex_lock_nested(&adap->userspace_clients_lock, |
| i2c_adapter_depth(adap)); |
| list_for_each_entry_safe(client, next, &adap->userspace_clients, |
| detected) { |
| dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, |
| client->addr); |
| list_del(&client->detected); |
| i2c_unregister_device(client); |
| } |
| mutex_unlock(&adap->userspace_clients_lock); |
| |
| /* Detach any active clients. This can't fail, thus we do not |
| * check the returned value. This is a two-pass process, because |
| * we can't remove the dummy devices during the first pass: they |
| * could have been instantiated by real devices wishing to clean |
| * them up properly, so we give them a chance to do that first. */ |
| device_for_each_child(&adap->dev, NULL, __unregister_client); |
| device_for_each_child(&adap->dev, NULL, __unregister_dummy); |
| |
| #ifdef CONFIG_I2C_COMPAT |
| class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, |
| adap->dev.parent); |
| #endif |
| |
| /* device name is gone after device_unregister */ |
| dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); |
| |
| pm_runtime_disable(&adap->dev); |
| |
| i2c_host_notify_irq_teardown(adap); |
| |
| /* wait until all references to the device are gone |
| * |
| * FIXME: This is old code and should ideally be replaced by an |
| * alternative which results in decoupling the lifetime of the struct |
| * device from the i2c_adapter, like spi or netdev do. Any solution |
| * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled! |
| */ |
| init_completion(&adap->dev_released); |
| device_unregister(&adap->dev); |
| wait_for_completion(&adap->dev_released); |
| |
| /* free bus id */ |
| mutex_lock(&core_lock); |
| idr_remove(&i2c_adapter_idr, adap->nr); |
| mutex_unlock(&core_lock); |
| |
| /* Clear the device structure in case this adapter is ever going to be |
| added again */ |
| memset(&adap->dev, 0, sizeof(adap->dev)); |
| } |
| EXPORT_SYMBOL(i2c_del_adapter); |
| |
| /** |
| * i2c_parse_fw_timings - get I2C related timing parameters from firmware |
| * @dev: The device to scan for I2C timing properties |
| * @t: the i2c_timings struct to be filled with values |
| * @use_defaults: bool to use sane defaults derived from the I2C specification |
| * when properties are not found, otherwise use 0 |
| * |
| * Scan the device for the generic I2C properties describing timing parameters |
| * for the signal and fill the given struct with the results. If a property was |
| * not found and use_defaults was true, then maximum timings are assumed which |
| * are derived from the I2C specification. If use_defaults is not used, the |
| * results will be 0, so drivers can apply their own defaults later. The latter |
| * is mainly intended for avoiding regressions of existing drivers which want |
| * to switch to this function. New drivers almost always should use the defaults. |
| */ |
| |
| void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults) |
| { |
| int ret; |
| |
| memset(t, 0, sizeof(*t)); |
| |
| ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz); |
| if (ret && use_defaults) |
| t->bus_freq_hz = 100000; |
| |
| ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns); |
| if (ret && use_defaults) { |
| if (t->bus_freq_hz <= 100000) |
| t->scl_rise_ns = 1000; |
| else if (t->bus_freq_hz <= 400000) |
| t->scl_rise_ns = 300; |
| else |
| t->scl_rise_ns = 120; |
| } |
| |
| ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns); |
| if (ret && use_defaults) { |
| if (t->bus_freq_hz <= 400000) |
| t->scl_fall_ns = 300; |
| else |
| t->scl_fall_ns = 120; |
| } |
| |
| device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns); |
| |
| ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns); |
| if (ret && use_defaults) |
| t->sda_fall_ns = t->scl_fall_ns; |
| } |
| EXPORT_SYMBOL_GPL(i2c_parse_fw_timings); |
| |
| /* ------------------------------------------------------------------------- */ |
| |
| int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) |
| { |
| int res; |
| |
| mutex_lock(&core_lock); |
| res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); |
| mutex_unlock(&core_lock); |
| |
| return res; |
| } |
| EXPORT_SYMBOL_GPL(i2c_for_each_dev); |
| |
| static int __process_new_driver(struct device *dev, void *data) |
| { |
| if (dev->type != &i2c_adapter_type) |
| return 0; |
| return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
| } |
| |
| /* |
| * An i2c_driver is used with one or more i2c_client (device) nodes to access |
| * i2c slave chips, on a bus instance associated with some i2c_adapter. |
| */ |
| |
| int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
| { |
| int res; |
| |
| /* Can't register until after driver model init */ |
| if (WARN_ON(!is_registered)) |
| return -EAGAIN; |
| |
| /* add the driver to the list of i2c drivers in the driver core */ |
| driver->driver.owner = owner; |
| driver->driver.bus = &i2c_bus_type; |
| INIT_LIST_HEAD(&driver->clients); |
| |
| /* When registration returns, the driver core |
| * will have called probe() for all matching-but-unbound devices. |
| */ |
| res = driver_register(&driver->driver); |
| if (res) |
| return res; |
| |
| pr_debug("driver [%s] registered\n", driver->driver.name); |
| |
| /* Walk the adapters that are already present */ |
| i2c_for_each_dev(driver, __process_new_driver); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(i2c_register_driver); |
| |
| static int __process_removed_driver(struct device *dev, void *data) |
| { |
| if (dev->type == &i2c_adapter_type) |
| i2c_do_del_adapter(data, to_i2c_adapter(dev)); |
| return 0; |
| } |
| |
| /** |
| * i2c_del_driver - unregister I2C driver |
| * @driver: the driver being unregistered |
| * Context: can sleep |
| */ |
| void i2c_del_driver(struct i2c_driver *driver) |
| { |
| i2c_for_each_dev(driver, __process_removed_driver); |
| |
| driver_unregister(&driver->driver); |
| pr_debug("driver [%s] unregistered\n", driver->driver.name); |
| } |
| EXPORT_SYMBOL(i2c_del_driver); |
| |
| /* ------------------------------------------------------------------------- */ |
| |
| /** |
| * i2c_use_client - increments the reference count of the i2c client structure |
| * @client: the client being referenced |
| * |
| * Each live reference to a client should be refcounted. The driver model does |
| * that automatically as part of driver binding, so that most drivers don't |
| * need to do this explicitly: they hold a reference until they're unbound |
| * from the device. |
| * |
| * A pointer to the client with the incremented reference counter is returned. |
| */ |
| struct i2c_client *i2c_use_client(struct i2c_client *client) |
| { |
| if (client && get_device(&client->dev)) |
| return client; |
| return NULL; |
| } |
| EXPORT_SYMBOL(i2c_use_client); |
| |
| /** |
| * i2c_release_client - release a use of the i2c client structure |
| * @client: the client being no longer referenced |
| * |
| * Must be called when a user of a client is finished with it. |
| */ |
| void i2c_release_client(struct i2c_client *client) |
| { |
| if (client) |
| put_device(&client->dev); |
| } |
| EXPORT_SYMBOL(i2c_release_client); |
| |
| struct i2c_cmd_arg { |
| unsigned cmd; |
| void *arg; |
| }; |
| |
| static int i2c_cmd(struct device *dev, void *_arg) |
| { |
| struct i2c_client *client = i2c_verify_client(dev); |
| struct i2c_cmd_arg *arg = _arg; |
| struct i2c_driver *driver; |
| |
| if (!client || !client->dev.driver) |
| return 0; |
| |
| driver = to_i2c_driver(client->dev.driver); |
| if (driver->command) |
| driver->command(client, arg->cmd, arg->arg); |
| return 0; |
| } |
| |
| void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
| { |
| struct i2c_cmd_arg cmd_arg; |
| |
| cmd_arg.cmd = cmd; |
| cmd_arg.arg = arg; |
| device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); |
| } |
| EXPORT_SYMBOL(i2c_clients_command); |
| |
| static int __init i2c_init(void) |
| { |
| int retval; |
| |
| retval = of_alias_get_highest_id("i2c"); |
| |
| down_write(&__i2c_board_lock); |
| if (retval >= __i2c_first_dynamic_bus_num) |
| __i2c_first_dynamic_bus_num = retval + 1; |
| up_write(&__i2c_board_lock); |
| |
| retval = bus_register(&i2c_bus_type); |
| if (retval) |
| return retval; |
| |
| is_registered = true; |
| |
| #ifdef CONFIG_I2C_COMPAT |
| i2c_adapter_compat_class = class_compat_register("i2c-adapter"); |
| if (!i2c_adapter_compat_class) { |
| retval = -ENOMEM; |
| goto bus_err; |
| } |
| #endif |
| retval = i2c_add_driver(&dummy_driver); |
| if (retval) |
| goto class_err; |
| |
| if (IS_ENABLED(CONFIG_OF_DYNAMIC)) |
| WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier)); |
| if (IS_ENABLED(CONFIG_ACPI)) |
| WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier)); |
| |
| return 0; |
| |
| class_err: |
| #ifdef CONFIG_I2C_COMPAT |
| class_compat_unregister(i2c_adapter_compat_class); |
| bus_err: |
| #endif |
| is_registered = false; |
| bus_unregister(&i2c_bus_type); |
| return retval; |
| } |
| |
| static void __exit i2c_exit(void) |
| { |
| if (IS_ENABLED(CONFIG_ACPI)) |
| WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier)); |
| if (IS_ENABLED(CONFIG_OF_DYNAMIC)) |
| WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier)); |
| i2c_del_driver(&dummy_driver); |
| #ifdef CONFIG_I2C_COMPAT |
| class_compat_unregister(i2c_adapter_compat_class); |
| #endif |
| bus_unregister(&i2c_bus_type); |
| tracepoint_synchronize_unregister(); |
| } |
| |
| /* We must initialize early, because some subsystems register i2c drivers |
| * in subsys_initcall() code, but are linked (and initialized) before i2c. |
| */ |
| postcore_initcall(i2c_init); |
| module_exit(i2c_exit); |
| |
| /* ---------------------------------------------------- |
| * the functional interface to the i2c busses. |
| * ---------------------------------------------------- |
| */ |
| |
| /* Check if val is exceeding the quirk IFF quirk is non 0 */ |
| #define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk))) |
| |
| static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg) |
| { |
| dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n", |
| err_msg, msg->addr, msg->len, |
| msg->flags & I2C_M_RD ? "read" : "write"); |
| return -EOPNOTSUPP; |
| } |
| |
| static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
| { |
| const struct i2c_adapter_quirks *q = adap->quirks; |
| int max_num = q->max_num_msgs, i; |
| bool do_len_check = true; |
| |
| if (q->flags & I2C_AQ_COMB) { |
| max_num = 2; |
| |
| /* special checks for combined messages */ |
| if (num == 2) { |
| if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD) |
| return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write"); |
| |
| if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD)) |
| return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read"); |
| |
| if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr) |
| return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr"); |
| |
| if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len)) |
| return i2c_quirk_error(adap, &msgs[0], "msg too long"); |
| |
| if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len)) |
| return i2c_quirk_error(adap, &msgs[1], "msg too long"); |
| |
| do_len_check = false; |
| } |
| } |
| |
| if (i2c_quirk_exceeded(num, max_num)) |
| return i2c_quirk_error(adap, &msgs[0], "too many messages"); |
| |
| for (i = 0; i < num; i++) { |
| u16 len = msgs[i].len; |
| |
| if (msgs[i].flags & I2C_M_RD) { |
| if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len)) |
| return i2c_quirk_error(adap, &msgs[i], "msg too long"); |
| } else { |
| if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len)) |
| return i2c_quirk_error(adap, &msgs[i], "msg too long"); |
| } |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * __i2c_transfer - unlocked flavor of i2c_transfer |
| * @adap: Handle to I2C bus |
| * @msgs: One or more messages to execute before STOP is issued to |
| * terminate the operation; each message begins with a START. |
| * @num: Number of messages to be executed. |
| * |
| * Returns negative errno, else the number of messages executed. |
| * |
| * Adapter lock must be held when calling this function. No debug logging |
| * takes place. adap->algo->master_xfer existence isn't checked. |
| */ |
| int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
| { |
| unsigned long orig_jiffies; |
| int ret, try; |
| |
| if (WARN_ON(!msgs || num < 1)) |
| return -EINVAL; |
| |
| if (adap->quirks && i2c_check_for_quirks(adap, msgs, num)) |
| return -EOPNOTSUPP; |
| |
| /* |
| * i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets |
| * enabled. This is an efficient way of keeping the for-loop from |
| * being executed when not needed. |
| */ |
| if (static_branch_unlikely(&i2c_trace_msg_key)) { |
| int i; |
| for (i = 0; i < num; i++) |
| if (msgs[i].flags & I2C_M_RD) |
| trace_i2c_read(adap, &msgs[i], i); |
| else |
| trace_i2c_write(adap, &msgs[i], i); |
| } |
| |
| /* Retry automatically on arbitration loss */ |
| orig_jiffies = jiffies; |
| for (ret = 0, try = 0; try <= adap->retries; try++) { |
| ret = adap->algo->master_xfer(adap, msgs, num); |
| if (ret != -EAGAIN) |
| break; |
| if (time_after(jiffies, orig_jiffies + adap->timeout)) |
| break; |
| } |
| |
| if (static_branch_unlikely(&i2c_trace_msg_key)) { |
| int i; |
| for (i = 0; i < ret; i++) |
| if (msgs[i].flags & I2C_M_RD) |
| trace_i2c_reply(adap, &msgs[i], i); |
| trace_i2c_result(adap, num, ret); |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(__i2c_transfer); |
| |
| /** |
| * i2c_transfer - execute a single or combined I2C message |
| * @adap: Handle to I2C bus |
| * @msgs: One or more messages to execute before STOP is issued to |
| * terminate the operation; each message begins with a START. |
| * @num: Number of messages to be executed. |
| * |
| * Returns negative errno, else the number of messages executed. |
| * |
| * Note that there is no requirement that each message be sent to |
| * the same slave address, although that is the most common model. |
| */ |
| int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
| { |
| int ret; |
| |
| /* REVISIT the fault reporting model here is weak: |
| * |
| * - When we get an error after receiving N bytes from a slave, |
| * there is no way to report "N". |
| * |
| * - When we get a NAK after transmitting N bytes to a slave, |
| * there is no way to report "N" ... or to let the master |
| * continue executing the rest of this combined message, if |
| * that's the appropriate response. |
| * |
| * - When for example "num" is two and we successfully complete |
| * the first message but get an error part way through the |
| * second, it's unclear whether that should be reported as |
| * one (discarding status on the second message) or errno |
| * (discarding status on the first one). |
| */ |
| |
| if (adap->algo->master_xfer) { |
| #ifdef DEBUG |
| for (ret = 0; ret < num; ret++) { |
| dev_dbg(&adap->dev, |
| "master_xfer[%d] %c, addr=0x%02x, len=%d%s\n", |
| ret, (msgs[ret].flags & I2C_M_RD) ? 'R' : 'W', |
| msgs[ret].addr, msgs[ret].len, |
| (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); |
| } |
| #endif |
| |
| if (in_atomic() || irqs_disabled()) { |
| ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT); |
| if (!ret) |
| /* I2C activity is ongoing. */ |
| return -EAGAIN; |
| } else { |
| i2c_lock_bus(adap, I2C_LOCK_SEGMENT); |
| } |
| |
| ret = __i2c_transfer(adap, msgs, num); |
| i2c_unlock_bus(adap, I2C_LOCK_SEGMENT); |
| |
| return ret; |
| } else { |
| dev_dbg(&adap->dev, "I2C level transfers not supported\n"); |
| return -EOPNOTSUPP; |
| } |
| } |
| EXPORT_SYMBOL(i2c_transfer); |
| |
| /** |
| * i2c_transfer_buffer_flags - issue a single I2C message transferring data |
| * to/from a buffer |
| * @client: Handle to slave device |
| * @buf: Where the data is stored |
| * @count: How many bytes to transfer, must be less than 64k since msg.len is u16 |
| * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads |
| * |
| * Returns negative errno, or else the number of bytes transferred. |
| */ |
| int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf, |
| int count, u16 flags) |
| { |
| int ret; |
| struct i2c_msg msg = { |
| .addr = client->addr, |
| .flags = flags | (client->flags & I2C_M_TEN), |
| .len = count, |
| .buf = buf, |
| }; |
| |
| ret = i2c_transfer(client->adapter, &msg, 1); |
| |
| /* |
| * If everything went ok (i.e. 1 msg transferred), return #bytes |
| * transferred, else error code. |
| */ |
| return (ret == 1) ? count : ret; |
| } |
| EXPORT_SYMBOL(i2c_transfer_buffer_flags); |
| |
| /** |
| * i2c_get_device_id - get manufacturer, part id and die revision of a device |
| * @client: The device to query |
| * @id: The queried information |
| * |
| * Returns negative errno on error, zero on success. |
| */ |
| int i2c_get_device_id(const struct i2c_client *client, |
| struct i2c_device_identity *id) |
| { |
| struct i2c_adapter *adap = client->adapter; |
| union i2c_smbus_data raw_id; |
| int ret; |
| |
| if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) |
| return -EOPNOTSUPP; |
| |
| raw_id.block[0] = 3; |
| ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0, |
| I2C_SMBUS_READ, client->addr << 1, |
| I2C_SMBUS_I2C_BLOCK_DATA, &raw_id); |
| if (ret) |
| return ret; |
| |
| id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4); |
| id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3); |
| id->die_revision = raw_id.block[3] & 0x7; |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(i2c_get_device_id); |
| |
| /* ---------------------------------------------------- |
| * the i2c address scanning function |
| * Will not work for 10-bit addresses! |
| * ---------------------------------------------------- |
| */ |
| |
| /* |
| * Legacy default probe function, mostly relevant for SMBus. The default |
| * probe method is a quick write, but it is known to corrupt the 24RF08 |
| * EEPROMs due to a state machine bug, and could also irreversibly |
| * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, |
| * we use a short byte read instead. Also, some bus drivers don't implement |
| * quick write, so we fallback to a byte read in that case too. |
| * On x86, there is another special case for FSC hardware monitoring chips, |
| * which want regular byte reads (address 0x73.) Fortunately, these are the |
| * only known chips using this I2C address on PC hardware. |
| * Returns 1 if probe succeeded, 0 if not. |
| */ |
| static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) |
| { |
| int err; |
| union i2c_smbus_data dummy; |
| |
| #ifdef CONFIG_X86 |
| if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) |
| && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) |
| err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, |
| I2C_SMBUS_BYTE_DATA, &dummy); |
| else |
| #endif |
| if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) |
| && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) |
| err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, |
| I2C_SMBUS_QUICK, NULL); |
| else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) |
| err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, |
| I2C_SMBUS_BYTE, &dummy); |
| else { |
| dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", |
| addr); |
| err = -EOPNOTSUPP; |
| } |
| |
| return err >= 0; |
| } |
| |
| static int i2c_detect_address(struct i2c_client *temp_client, |
| struct i2c_driver *driver) |
| { |
| struct i2c_board_info info; |
| struct i2c_adapter *adapter = temp_client->adapter; |
| int addr = temp_client->addr; |
| int err; |
| |
| /* Make sure the address is valid */ |
| err = i2c_check_7bit_addr_validity_strict(addr); |
| if (err) { |
| dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", |
| addr); |
| return err; |
| } |
| |
| /* Skip if already in use (7 bit, no need to encode flags) */ |
| if (i2c_check_addr_busy(adapter, addr)) |
| return 0; |
| |
| /* Make sure there is something at this address */ |
| if (!i2c_default_probe(adapter, addr)) |
| return 0; |
| |
| /* Finally call the custom detection function */ |
| memset(&info, 0, sizeof(struct i2c_board_info)); |
| info.addr = addr; |
| err = driver->detect(temp_client, &info); |
| if (err) { |
| /* -ENODEV is returned if the detection fails. We catch it |
| here as this isn't an error. */ |
| return err == -ENODEV ? 0 : err; |
| } |
| |
| /* Consistency check */ |
| if (info.type[0] == '\0') { |
| dev_err(&adapter->dev, |
| "%s detection function provided no name for 0x%x\n", |
| driver->driver.name, addr); |
| } else { |
| struct i2c_client *client; |
| |
| /* Detection succeeded, instantiate the device */ |
| if (adapter->class & I2C_CLASS_DEPRECATED) |
| dev_warn(&adapter->dev, |
| "This adapter will soon drop class based instantiation of devices. " |
| "Please make sure client 0x%02x gets instantiated by other means. " |
| "Check 'Documentation/i2c/instantiating-devices' for details.\n", |
| info.addr); |
| |
| dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", |
| info.type, info.addr); |
| client = i2c_new_device(adapter, &info); |
| if (client) |
| list_add_tail(&client->detected, &driver->clients); |
| else |
| dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", |
| info.type, info.addr); |
| } |
| return 0; |
| } |
| |
| static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) |
| { |
| const unsigned short *address_list; |
| struct i2c_client *temp_client; |
| int i, err = 0; |
| int adap_id = i2c_adapter_id(adapter); |
| |
| address_list = driver->address_list; |
| if (!driver->detect || !address_list) |
| return 0; |
| |
| /* Warn that the adapter lost class based instantiation */ |
| if (adapter->class == I2C_CLASS_DEPRECATED) { |
| dev_dbg(&adapter->dev, |
| "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. " |
| "If you need it, check 'Documentation/i2c/instantiating-devices' for alternatives.\n", |
| driver->driver.name); |
| return 0; |
| } |
| |
| /* Stop here if the classes do not match */ |
| if (!(adapter->class & driver->class)) |
| return 0; |
| |
| /* Set up a temporary client to help detect callback */ |
| temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); |
| if (!temp_client) |
| return -ENOMEM; |
| temp_client->adapter = adapter; |
| |
| for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
| dev_dbg(&adapter->dev, |
| "found normal entry for adapter %d, addr 0x%02x\n", |
| adap_id, address_list[i]); |
| temp_client->addr = address_list[i]; |
| err = i2c_detect_address(temp_client, driver); |
| if (unlikely(err)) |
| break; |
| } |
| |
| kfree(temp_client); |
| return err; |
| } |
| |
| int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) |
| { |
| return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, |
| I2C_SMBUS_QUICK, NULL) >= 0; |
| } |
| EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); |
| |
| struct i2c_client * |
| i2c_new_probed_device(struct i2c_adapter *adap, |
| struct i2c_board_info *info, |
| unsigned short const *addr_list, |
| int (*probe)(struct i2c_adapter *, unsigned short addr)) |
| { |
| int i; |
| |
| if (!probe) |
| probe = i2c_default_probe; |
| |
| for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
| /* Check address validity */ |
| if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) { |
| dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n", |
| addr_list[i]); |
| continue; |
| } |
| |
| /* Check address availability (7 bit, no need to encode flags) */ |
| if (i2c_check_addr_busy(adap, addr_list[i])) { |
| dev_dbg(&adap->dev, |
| "Address 0x%02x already in use, not probing\n", |
| addr_list[i]); |
| continue; |
| } |
| |
| /* Test address responsiveness */ |
| if (probe(adap, addr_list[i])) |
| break; |
| } |
| |
| if (addr_list[i] == I2C_CLIENT_END) { |
| dev_dbg(&adap->dev, "Probing failed, no device found\n"); |
| return NULL; |
| } |
| |
| info->addr = addr_list[i]; |
| return i2c_new_device(adap, info); |
| } |
| EXPORT_SYMBOL_GPL(i2c_new_probed_device); |
| |
| struct i2c_adapter *i2c_get_adapter(int nr) |
| { |
| struct i2c_adapter *adapter; |
| |
| mutex_lock(&core_lock); |
| adapter = idr_find(&i2c_adapter_idr, nr); |
| if (!adapter) |
| goto exit; |
| |
| if (try_module_get(adapter->owner)) |
| get_device(&adapter->dev); |
| else |
| adapter = NULL; |
| |
| exit: |
| mutex_unlock(&core_lock); |
| return adapter; |
| } |
| EXPORT_SYMBOL(i2c_get_adapter); |
| |
| void i2c_put_adapter(struct i2c_adapter *adap) |
| { |
| if (!adap) |
| return; |
| |
| put_device(&adap->dev); |
| module_put(adap->owner); |
| } |
| EXPORT_SYMBOL(i2c_put_adapter); |
| |
| /** |
| * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg |
| * @msg: the message to be checked |
| * @threshold: the minimum number of bytes for which using DMA makes sense |
| * |
| * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO. |
| * Or a valid pointer to be used with DMA. After use, release it by |
| * calling i2c_release_dma_safe_msg_buf(). |
| * |
| * This function must only be called from process context! |
| */ |
| u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold) |
| { |
| if (msg->len < threshold) |
| return NULL; |
| |
| if (msg->flags & I2C_M_DMA_SAFE) |
| return msg->buf; |
| |
| pr_debug("using bounce buffer for addr=0x%02x, len=%d\n", |
| msg->addr, msg->len); |
| |
| if (msg->flags & I2C_M_RD) |
| return kzalloc(msg->len, GFP_KERNEL); |
| else |
| return kmemdup(msg->buf, msg->len, GFP_KERNEL); |
| } |
| EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf); |
| |
| /** |
| * i2c_release_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg |
| * @msg: the message to be synced with |
| * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL. |
| */ |
| void i2c_release_dma_safe_msg_buf(struct i2c_msg *msg, u8 *buf) |
| { |
| if (!buf || buf == msg->buf) |
| return; |
| |
| if (msg->flags & I2C_M_RD) |
| memcpy(msg->buf, buf, msg->len); |
| |
| kfree(buf); |
| } |
| EXPORT_SYMBOL_GPL(i2c_release_dma_safe_msg_buf); |
| |
| MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); |
| MODULE_DESCRIPTION("I2C-Bus main module"); |
| MODULE_LICENSE("GPL"); |