| /* i2c-core.c - a device driver for the iic-bus interface */ |
| /* ------------------------------------------------------------------------- */ |
| /* Copyright (C) 1995-99 Simon G. Vogl |
| |
| 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. */ |
| /* ------------------------------------------------------------------------- */ |
| |
| /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>. |
| All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl> |
| SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and |
| Jean Delvare <jdelvare@suse.de> |
| Mux support by Rodolfo Giometti <giometti@enneenne.com> and |
| Michael Lawnick <michael.lawnick.ext@nsn.com> |
| OF support is copyright (c) 2008 Jochen Friedrich <jochen@scram.de> |
| (based on a previous patch from Jon Smirl <jonsmirl@gmail.com>) and |
| (c) 2013 Wolfram Sang <wsa@the-dreams.de> |
| I2C ACPI code Copyright (C) 2014 Intel Corp |
| Author: Lan Tianyu <tianyu.lan@intel.com> |
| I2C slave support (c) 2014 by Wolfram Sang <wsa@sang-engineering.com> |
| */ |
| |
| #include <dt-bindings/i2c/i2c.h> |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/delay.h> |
| #include <linux/errno.h> |
| #include <linux/gpio.h> |
| #include <linux/slab.h> |
| #include <linux/i2c.h> |
| #include <linux/init.h> |
| #include <linux/idr.h> |
| #include <linux/mutex.h> |
| #include <linux/of.h> |
| #include <linux/of_device.h> |
| #include <linux/of_irq.h> |
| #include <linux/clk/clk-conf.h> |
| #include <linux/completion.h> |
| #include <linux/hardirq.h> |
| #include <linux/irqflags.h> |
| #include <linux/rwsem.h> |
| #include <linux/pm_runtime.h> |
| #include <linux/pm_domain.h> |
| #include <linux/pm_wakeirq.h> |
| #include <linux/acpi.h> |
| #include <linux/jump_label.h> |
| #include <asm/uaccess.h> |
| #include <linux/err.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 |
| |
| /* 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 struct device_type i2c_client_type; |
| static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
| |
| static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE; |
| |
| void i2c_transfer_trace_reg(void) |
| { |
| static_key_slow_inc(&i2c_trace_msg); |
| } |
| |
| void i2c_transfer_trace_unreg(void) |
| { |
| static_key_slow_dec(&i2c_trace_msg); |
| } |
| |
| #if defined(CONFIG_ACPI) |
| struct acpi_i2c_handler_data { |
| struct acpi_connection_info info; |
| struct i2c_adapter *adapter; |
| }; |
| |
| struct gsb_buffer { |
| u8 status; |
| u8 len; |
| union { |
| u16 wdata; |
| u8 bdata; |
| u8 data[0]; |
| }; |
| } __packed; |
| |
| struct acpi_i2c_lookup { |
| struct i2c_board_info *info; |
| acpi_handle adapter_handle; |
| acpi_handle device_handle; |
| }; |
| |
| static int acpi_i2c_find_address(struct acpi_resource *ares, void *data) |
| { |
| struct acpi_i2c_lookup *lookup = data; |
| struct i2c_board_info *info = lookup->info; |
| struct acpi_resource_i2c_serialbus *sb; |
| acpi_handle adapter_handle; |
| acpi_status status; |
| |
| if (info->addr || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) |
| return 1; |
| |
| sb = &ares->data.i2c_serial_bus; |
| if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) |
| return 1; |
| |
| /* |
| * Extract the ResourceSource and make sure that the handle matches |
| * with the I2C adapter handle. |
| */ |
| status = acpi_get_handle(lookup->device_handle, |
| sb->resource_source.string_ptr, |
| &adapter_handle); |
| if (ACPI_SUCCESS(status) && adapter_handle == lookup->adapter_handle) { |
| info->addr = sb->slave_address; |
| if (sb->access_mode == ACPI_I2C_10BIT_MODE) |
| info->flags |= I2C_CLIENT_TEN; |
| } |
| |
| return 1; |
| } |
| |
| static acpi_status acpi_i2c_add_device(acpi_handle handle, u32 level, |
| void *data, void **return_value) |
| { |
| struct i2c_adapter *adapter = data; |
| struct list_head resource_list; |
| struct acpi_i2c_lookup lookup; |
| struct resource_entry *entry; |
| struct i2c_board_info info; |
| struct acpi_device *adev; |
| int ret; |
| |
| if (acpi_bus_get_device(handle, &adev)) |
| return AE_OK; |
| if (acpi_bus_get_status(adev) || !adev->status.present) |
| return AE_OK; |
| |
| memset(&info, 0, sizeof(info)); |
| info.fwnode = acpi_fwnode_handle(adev); |
| |
| memset(&lookup, 0, sizeof(lookup)); |
| lookup.adapter_handle = ACPI_HANDLE(&adapter->dev); |
| lookup.device_handle = handle; |
| lookup.info = &info; |
| |
| /* |
| * Look up for I2cSerialBus resource with ResourceSource that |
| * matches with this adapter. |
| */ |
| INIT_LIST_HEAD(&resource_list); |
| ret = acpi_dev_get_resources(adev, &resource_list, |
| acpi_i2c_find_address, &lookup); |
| acpi_dev_free_resource_list(&resource_list); |
| |
| if (ret < 0 || !info.addr) |
| return AE_OK; |
| |
| /* Then fill IRQ number if any */ |
| ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL); |
| if (ret < 0) |
| return AE_OK; |
| |
| resource_list_for_each_entry(entry, &resource_list) { |
| if (resource_type(entry->res) == IORESOURCE_IRQ) { |
| info.irq = entry->res->start; |
| break; |
| } |
| } |
| |
| acpi_dev_free_resource_list(&resource_list); |
| |
| adev->power.flags.ignore_parent = true; |
| strlcpy(info.type, dev_name(&adev->dev), sizeof(info.type)); |
| if (!i2c_new_device(adapter, &info)) { |
| adev->power.flags.ignore_parent = false; |
| dev_err(&adapter->dev, |
| "failed to add I2C device %s from ACPI\n", |
| dev_name(&adev->dev)); |
| } |
| |
| return AE_OK; |
| } |
| |
| #define ACPI_I2C_MAX_SCAN_DEPTH 32 |
| |
| /** |
| * acpi_i2c_register_devices - enumerate I2C slave devices behind adapter |
| * @adap: pointer to adapter |
| * |
| * Enumerate all I2C slave devices behind this adapter by walking the ACPI |
| * namespace. When a device is found it will be added to the Linux device |
| * model and bound to the corresponding ACPI handle. |
| */ |
| static void acpi_i2c_register_devices(struct i2c_adapter *adap) |
| { |
| acpi_status status; |
| |
| if (!has_acpi_companion(&adap->dev)) |
| return; |
| |
| status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, |
| ACPI_I2C_MAX_SCAN_DEPTH, |
| acpi_i2c_add_device, NULL, |
| adap, NULL); |
| if (ACPI_FAILURE(status)) |
| dev_warn(&adap->dev, "failed to enumerate I2C slaves\n"); |
| } |
| |
| #else /* CONFIG_ACPI */ |
| static inline void acpi_i2c_register_devices(struct i2c_adapter *adap) { } |
| #endif /* CONFIG_ACPI */ |
| |
| #ifdef CONFIG_ACPI_I2C_OPREGION |
| static int acpi_gsb_i2c_read_bytes(struct i2c_client *client, |
| u8 cmd, u8 *data, u8 data_len) |
| { |
| |
| struct i2c_msg msgs[2]; |
| int ret; |
| u8 *buffer; |
| |
| buffer = kzalloc(data_len, GFP_KERNEL); |
| if (!buffer) |
| return AE_NO_MEMORY; |
| |
| msgs[0].addr = client->addr; |
| msgs[0].flags = client->flags; |
| msgs[0].len = 1; |
| msgs[0].buf = &cmd; |
| |
| msgs[1].addr = client->addr; |
| msgs[1].flags = client->flags | I2C_M_RD; |
| msgs[1].len = data_len; |
| msgs[1].buf = buffer; |
| |
| ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); |
| if (ret < 0) |
| dev_err(&client->adapter->dev, "i2c read failed\n"); |
| else |
| memcpy(data, buffer, data_len); |
| |
| kfree(buffer); |
| return ret; |
| } |
| |
| static int acpi_gsb_i2c_write_bytes(struct i2c_client *client, |
| u8 cmd, u8 *data, u8 data_len) |
| { |
| |
| struct i2c_msg msgs[1]; |
| u8 *buffer; |
| int ret = AE_OK; |
| |
| buffer = kzalloc(data_len + 1, GFP_KERNEL); |
| if (!buffer) |
| return AE_NO_MEMORY; |
| |
| buffer[0] = cmd; |
| memcpy(buffer + 1, data, data_len); |
| |
| msgs[0].addr = client->addr; |
| msgs[0].flags = client->flags; |
| msgs[0].len = data_len + 1; |
| msgs[0].buf = buffer; |
| |
| ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); |
| if (ret < 0) |
| dev_err(&client->adapter->dev, "i2c write failed\n"); |
| |
| kfree(buffer); |
| return ret; |
| } |
| |
| static acpi_status |
| acpi_i2c_space_handler(u32 function, acpi_physical_address command, |
| u32 bits, u64 *value64, |
| void *handler_context, void *region_context) |
| { |
| struct gsb_buffer *gsb = (struct gsb_buffer *)value64; |
| struct acpi_i2c_handler_data *data = handler_context; |
| struct acpi_connection_info *info = &data->info; |
| struct acpi_resource_i2c_serialbus *sb; |
| struct i2c_adapter *adapter = data->adapter; |
| struct i2c_client *client; |
| struct acpi_resource *ares; |
| u32 accessor_type = function >> 16; |
| u8 action = function & ACPI_IO_MASK; |
| acpi_status ret; |
| int status; |
| |
| ret = acpi_buffer_to_resource(info->connection, info->length, &ares); |
| if (ACPI_FAILURE(ret)) |
| return ret; |
| |
| client = kzalloc(sizeof(*client), GFP_KERNEL); |
| if (!client) { |
| ret = AE_NO_MEMORY; |
| goto err; |
| } |
| |
| if (!value64 || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) { |
| ret = AE_BAD_PARAMETER; |
| goto err; |
| } |
| |
| sb = &ares->data.i2c_serial_bus; |
| if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) { |
| ret = AE_BAD_PARAMETER; |
| goto err; |
| } |
| |
| client->adapter = adapter; |
| client->addr = sb->slave_address; |
| |
| if (sb->access_mode == ACPI_I2C_10BIT_MODE) |
| client->flags |= I2C_CLIENT_TEN; |
| |
| switch (accessor_type) { |
| case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV: |
| if (action == ACPI_READ) { |
| status = i2c_smbus_read_byte(client); |
| if (status >= 0) { |
| gsb->bdata = status; |
| status = 0; |
| } |
| } else { |
| status = i2c_smbus_write_byte(client, gsb->bdata); |
| } |
| break; |
| |
| case ACPI_GSB_ACCESS_ATTRIB_BYTE: |
| if (action == ACPI_READ) { |
| status = i2c_smbus_read_byte_data(client, command); |
| if (status >= 0) { |
| gsb->bdata = status; |
| status = 0; |
| } |
| } else { |
| status = i2c_smbus_write_byte_data(client, command, |
| gsb->bdata); |
| } |
| break; |
| |
| case ACPI_GSB_ACCESS_ATTRIB_WORD: |
| if (action == ACPI_READ) { |
| status = i2c_smbus_read_word_data(client, command); |
| if (status >= 0) { |
| gsb->wdata = status; |
| status = 0; |
| } |
| } else { |
| status = i2c_smbus_write_word_data(client, command, |
| gsb->wdata); |
| } |
| break; |
| |
| case ACPI_GSB_ACCESS_ATTRIB_BLOCK: |
| if (action == ACPI_READ) { |
| status = i2c_smbus_read_block_data(client, command, |
| gsb->data); |
| if (status >= 0) { |
| gsb->len = status; |
| status = 0; |
| } |
| } else { |
| status = i2c_smbus_write_block_data(client, command, |
| gsb->len, gsb->data); |
| } |
| break; |
| |
| case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE: |
| if (action == ACPI_READ) { |
| status = acpi_gsb_i2c_read_bytes(client, command, |
| gsb->data, info->access_length); |
| if (status > 0) |
| status = 0; |
| } else { |
| status = acpi_gsb_i2c_write_bytes(client, command, |
| gsb->data, info->access_length); |
| } |
| break; |
| |
| default: |
| pr_info("protocol(0x%02x) is not supported.\n", accessor_type); |
| ret = AE_BAD_PARAMETER; |
| goto err; |
| } |
| |
| gsb->status = status; |
| |
| err: |
| kfree(client); |
| ACPI_FREE(ares); |
| return ret; |
| } |
| |
| |
| static int acpi_i2c_install_space_handler(struct i2c_adapter *adapter) |
| { |
| acpi_handle handle; |
| struct acpi_i2c_handler_data *data; |
| acpi_status status; |
| |
| if (!adapter->dev.parent) |
| return -ENODEV; |
| |
| handle = ACPI_HANDLE(adapter->dev.parent); |
| |
| if (!handle) |
| return -ENODEV; |
| |
| data = kzalloc(sizeof(struct acpi_i2c_handler_data), |
| GFP_KERNEL); |
| if (!data) |
| return -ENOMEM; |
| |
| data->adapter = adapter; |
| status = acpi_bus_attach_private_data(handle, (void *)data); |
| if (ACPI_FAILURE(status)) { |
| kfree(data); |
| return -ENOMEM; |
| } |
| |
| status = acpi_install_address_space_handler(handle, |
| ACPI_ADR_SPACE_GSBUS, |
| &acpi_i2c_space_handler, |
| NULL, |
| data); |
| if (ACPI_FAILURE(status)) { |
| dev_err(&adapter->dev, "Error installing i2c space handler\n"); |
| acpi_bus_detach_private_data(handle); |
| kfree(data); |
| return -ENOMEM; |
| } |
| |
| acpi_walk_dep_device_list(handle); |
| return 0; |
| } |
| |
| static void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter) |
| { |
| acpi_handle handle; |
| struct acpi_i2c_handler_data *data; |
| acpi_status status; |
| |
| if (!adapter->dev.parent) |
| return; |
| |
| handle = ACPI_HANDLE(adapter->dev.parent); |
| |
| if (!handle) |
| return; |
| |
| acpi_remove_address_space_handler(handle, |
| ACPI_ADR_SPACE_GSBUS, |
| &acpi_i2c_space_handler); |
| |
| status = acpi_bus_get_private_data(handle, (void **)&data); |
| if (ACPI_SUCCESS(status)) |
| kfree(data); |
| |
| acpi_bus_detach_private_data(handle); |
| } |
| #else /* CONFIG_ACPI_I2C_OPREGION */ |
| static inline void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter) |
| { } |
| |
| static inline int acpi_i2c_install_space_handler(struct i2c_adapter *adapter) |
| { return 0; } |
| #endif /* CONFIG_ACPI_I2C_OPREGION */ |
| |
| /* ------------------------------------------------------------------------- */ |
| |
| static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
| const struct i2c_client *client) |
| { |
| while (id->name[0]) { |
| if (strcmp(client->name, id->name) == 0) |
| return id; |
| id++; |
| } |
| return NULL; |
| } |
| |
| static int i2c_device_match(struct device *dev, struct device_driver *drv) |
| { |
| struct i2c_client *client = i2c_verify_client(dev); |
| struct i2c_driver *driver; |
| |
| if (!client) |
| return 0; |
| |
| /* Attempt an OF style match */ |
| if (of_driver_match_device(dev, drv)) |
| return 1; |
| |
| /* Then ACPI style match */ |
| if (acpi_driver_match_device(dev, drv)) |
| return 1; |
| |
| driver = to_i2c_driver(drv); |
| /* match on an id table if there is one */ |
| if (driver->id_table) |
| return i2c_match_id(driver->id_table, client) != NULL; |
| |
| return 0; |
| } |
| |
| |
| /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ |
| static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| int rc; |
| |
| rc = acpi_device_uevent_modalias(dev, env); |
| if (rc != -ENODEV) |
| return rc; |
| |
| if (add_uevent_var(env, "MODALIAS=%s%s", |
| I2C_MODULE_PREFIX, client->name)) |
| return -ENOMEM; |
| dev_dbg(dev, "uevent\n"); |
| return 0; |
| } |
| |
| /* i2c bus recovery routines */ |
| static int get_scl_gpio_value(struct i2c_adapter *adap) |
| { |
| return gpio_get_value(adap->bus_recovery_info->scl_gpio); |
| } |
| |
| static void set_scl_gpio_value(struct i2c_adapter *adap, int val) |
| { |
| gpio_set_value(adap->bus_recovery_info->scl_gpio, val); |
| } |
| |
| static int get_sda_gpio_value(struct i2c_adapter *adap) |
| { |
| return gpio_get_value(adap->bus_recovery_info->sda_gpio); |
| } |
| |
| static int i2c_get_gpios_for_recovery(struct i2c_adapter *adap) |
| { |
| struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; |
| struct device *dev = &adap->dev; |
| int ret = 0; |
| |
| ret = gpio_request_one(bri->scl_gpio, GPIOF_OPEN_DRAIN | |
| GPIOF_OUT_INIT_HIGH, "i2c-scl"); |
| if (ret) { |
| dev_warn(dev, "Can't get SCL gpio: %d\n", bri->scl_gpio); |
| return ret; |
| } |
| |
| if (bri->get_sda) { |
| if (gpio_request_one(bri->sda_gpio, GPIOF_IN, "i2c-sda")) { |
| /* work without SDA polling */ |
| dev_warn(dev, "Can't get SDA gpio: %d. Not using SDA polling\n", |
| bri->sda_gpio); |
| bri->get_sda = NULL; |
| } |
| } |
| |
| return ret; |
| } |
| |
| static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap) |
| { |
| struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; |
| |
| if (bri->get_sda) |
| gpio_free(bri->sda_gpio); |
| |
| gpio_free(bri->scl_gpio); |
| } |
| |
| /* |
| * 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 |
| |
| static int i2c_generic_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); |
| 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) { |
| /* Break if SDA is high */ |
| if (bri->get_sda && bri->get_sda(adap)) |
| break; |
| /* 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; |
| } |
| } |
| |
| val = !val; |
| bri->set_scl(adap, val); |
| ndelay(RECOVERY_NDELAY); |
| } |
| |
| if (bri->unprepare_recovery) |
| bri->unprepare_recovery(adap); |
| |
| return ret; |
| } |
| |
| int i2c_generic_scl_recovery(struct i2c_adapter *adap) |
| { |
| return i2c_generic_recovery(adap); |
| } |
| EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery); |
| |
| int i2c_generic_gpio_recovery(struct i2c_adapter *adap) |
| { |
| int ret; |
| |
| ret = i2c_get_gpios_for_recovery(adap); |
| if (ret) |
| return ret; |
| |
| ret = i2c_generic_recovery(adap); |
| i2c_put_gpios_for_recovery(adap); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(i2c_generic_gpio_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 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; |
| |
| if (!client->irq) { |
| int irq = -ENOENT; |
| |
| 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; |
| } |
| |
| driver = to_i2c_driver(dev->driver); |
| if (!driver->probe || !driver->id_table) |
| 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"); |
| } |
| |
| 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; |
| |
| status = driver->probe(client, i2c_match_id(driver->id_table, client)); |
| 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 = 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); |
| |
| static struct device_type i2c_client_type = { |
| .groups = i2c_dev_groups, |
| .uevent = i2c_device_uevent, |
| .release = i2c_client_dev_release, |
| }; |
| |
| |
| /** |
| * 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 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. */ |
| static 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_lock_adapter - Get exclusive access to an I2C bus segment |
| * @adapter: Target I2C bus segment |
| */ |
| void i2c_lock_adapter(struct i2c_adapter *adapter) |
| { |
| struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
| |
| if (parent) |
| i2c_lock_adapter(parent); |
| else |
| rt_mutex_lock(&adapter->bus_lock); |
| } |
| EXPORT_SYMBOL_GPL(i2c_lock_adapter); |
| |
| /** |
| * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment |
| * @adapter: Target I2C bus segment |
| */ |
| static int i2c_trylock_adapter(struct i2c_adapter *adapter) |
| { |
| struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
| |
| if (parent) |
| return i2c_trylock_adapter(parent); |
| else |
| return rt_mutex_trylock(&adapter->bus_lock); |
| } |
| |
| /** |
| * i2c_unlock_adapter - Release exclusive access to an I2C bus segment |
| * @adapter: Target I2C bus segment |
| */ |
| void i2c_unlock_adapter(struct i2c_adapter *adapter) |
| { |
| struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
| |
| if (parent) |
| i2c_unlock_adapter(parent); |
| else |
| rt_mutex_unlock(&adapter->bus_lock); |
| } |
| EXPORT_SYMBOL_GPL(i2c_unlock_adapter); |
| |
| static void i2c_dev_set_name(struct i2c_adapter *adap, |
| struct i2c_client *client) |
| { |
| struct acpi_device *adev = ACPI_COMPANION(&client->dev); |
| |
| 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)); |
| } |
| |
| /** |
| * 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; |
| |
| 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); |
| status = device_register(&client->dev); |
| if (status) |
| goto out_err; |
| |
| dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
| client->name, dev_name(&client->dev)); |
| |
| return client; |
| |
| 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->dev.of_node) |
| of_node_clear_flag(client->dev.of_node, OF_POPULATED); |
| 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 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); |
| } |
| |
| /* |
| * This function is only needed for mutex_lock_nested, so it is never |
| * called unless locking correctness checking is enabled. Thus we |
| * make it inline to avoid a compiler warning. That's what gcc ends up |
| * doing anyway. |
| */ |
| static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) |
| { |
| unsigned int depth = 0; |
| |
| while ((adapter = i2c_parent_is_i2c_adapter(adapter))) |
| depth++; |
| |
| return 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); |
| } |
| |
| /* OF support code */ |
| |
| #if IS_ENABLED(CONFIG_OF) |
| static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap, |
| struct device_node *node) |
| { |
| struct i2c_client *result; |
| struct i2c_board_info info = {}; |
| struct dev_archdata dev_ad = {}; |
| const __be32 *addr_be; |
| u32 addr; |
| int len; |
| |
| dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name); |
| |
| if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) { |
| dev_err(&adap->dev, "of_i2c: modalias failure on %s\n", |
| node->full_name); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| addr_be = of_get_property(node, "reg", &len); |
| if (!addr_be || (len < sizeof(*addr_be))) { |
| dev_err(&adap->dev, "of_i2c: invalid reg on %s\n", |
| node->full_name); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| addr = be32_to_cpup(addr_be); |
| if (addr & I2C_TEN_BIT_ADDRESS) { |
| addr &= ~I2C_TEN_BIT_ADDRESS; |
| info.flags |= I2C_CLIENT_TEN; |
| } |
| |
| if (addr & I2C_OWN_SLAVE_ADDRESS) { |
| addr &= ~I2C_OWN_SLAVE_ADDRESS; |
| info.flags |= I2C_CLIENT_SLAVE; |
| } |
| |
| if (i2c_check_addr_validity(addr, info.flags)) { |
| dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n", |
| info.addr, node->full_name); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| info.addr = addr; |
| info.of_node = of_node_get(node); |
| info.archdata = &dev_ad; |
| |
| if (of_get_property(node, "wakeup-source", NULL)) |
| info.flags |= I2C_CLIENT_WAKE; |
| |
| result = i2c_new_device(adap, &info); |
| if (result == NULL) { |
| dev_err(&adap->dev, "of_i2c: Failure registering %s\n", |
| node->full_name); |
| of_node_put(node); |
| return ERR_PTR(-EINVAL); |
| } |
| return result; |
| } |
| |
| static void of_i2c_register_devices(struct i2c_adapter *adap) |
| { |
| struct device_node *node; |
| |
| /* Only register child devices if the adapter has a node pointer set */ |
| if (!adap->dev.of_node) |
| return; |
| |
| dev_dbg(&adap->dev, "of_i2c: walking child nodes\n"); |
| |
| for_each_available_child_of_node(adap->dev.of_node, node) { |
| if (of_node_test_and_set_flag(node, OF_POPULATED)) |
| continue; |
| of_i2c_register_device(adap, node); |
| } |
| } |
| |
| static int of_dev_node_match(struct device *dev, void *data) |
| { |
| return dev->of_node == data; |
| } |
| |
| /* must call put_device() when done with returned i2c_client device */ |
| struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) |
| { |
| struct device *dev; |
| struct i2c_client *client; |
| |
| dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match); |
| if (!dev) |
| return NULL; |
| |
| client = i2c_verify_client(dev); |
| if (!client) |
| put_device(dev); |
| |
| return client; |
| } |
| EXPORT_SYMBOL(of_find_i2c_device_by_node); |
| |
| /* must call put_device() when done with returned i2c_adapter device */ |
| struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) |
| { |
| struct device *dev; |
| struct i2c_adapter *adapter; |
| |
| dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match); |
| if (!dev) |
| return NULL; |
| |
| adapter = i2c_verify_adapter(dev); |
| if (!adapter) |
| put_device(dev); |
| |
| return adapter; |
| } |
| EXPORT_SYMBOL(of_find_i2c_adapter_by_node); |
| |
| /* must call i2c_put_adapter() when done with returned i2c_adapter device */ |
| struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) |
| { |
| struct i2c_adapter *adapter; |
| |
| adapter = of_find_i2c_adapter_by_node(node); |
| if (!adapter) |
| return NULL; |
| |
| if (!try_module_get(adapter->owner)) { |
| put_device(&adapter->dev); |
| adapter = NULL; |
| } |
| |
| return adapter; |
| } |
| EXPORT_SYMBOL(of_get_i2c_adapter_by_node); |
| #else |
| static void of_i2c_register_devices(struct i2c_adapter *adap) { } |
| #endif /* CONFIG_OF */ |
| |
| 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 int i2c_register_adapter(struct i2c_adapter *adap) |
| { |
| int res = 0; |
| |
| /* Can't register until after driver model init */ |
| if (unlikely(WARN_ON(!i2c_bus_type.p))) { |
| res = -EAGAIN; |
| goto out_list; |
| } |
| |
| /* Sanity checks */ |
| if (unlikely(adap->name[0] == '\0')) { |
| pr_err("i2c-core: Attempt to register an adapter with " |
| "no name!\n"); |
| return -EINVAL; |
| } |
| if (unlikely(!adap->algo)) { |
| pr_err("i2c-core: Attempt to register adapter '%s' with " |
| "no algo!\n", adap->name); |
| return -EINVAL; |
| } |
| |
| rt_mutex_init(&adap->bus_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; |
| |
| 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) |
| goto out_list; |
| |
| dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
| |
| pm_runtime_no_callbacks(&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 |
| |
| /* bus recovery specific initialization */ |
| if (adap->bus_recovery_info) { |
| struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; |
| |
| if (!bri->recover_bus) { |
| dev_err(&adap->dev, "No recover_bus() found, not using recovery\n"); |
| adap->bus_recovery_info = NULL; |
| goto exit_recovery; |
| } |
| |
| /* Generic GPIO recovery */ |
| if (bri->recover_bus == i2c_generic_gpio_recovery) { |
| if (!gpio_is_valid(bri->scl_gpio)) { |
| dev_err(&adap->dev, "Invalid SCL gpio, not using recovery\n"); |
| adap->bus_recovery_info = NULL; |
| goto exit_recovery; |
| } |
| |
| if (gpio_is_valid(bri->sda_gpio)) |
| bri->get_sda = get_sda_gpio_value; |
| else |
| bri->get_sda = NULL; |
| |
| bri->get_scl = get_scl_gpio_value; |
| bri->set_scl = set_scl_gpio_value; |
| } else if (!bri->set_scl || !bri->get_scl) { |
| /* Generic SCL recovery */ |
| dev_err(&adap->dev, "No {get|set}_gpio() found, not using recovery\n"); |
| adap->bus_recovery_info = NULL; |
| } |
| } |
| |
| exit_recovery: |
| /* create pre-declared device nodes */ |
| of_i2c_register_devices(adap); |
| acpi_i2c_register_devices(adap); |
| acpi_i2c_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_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 (id < 0) |
| 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 (id < 0) |
| 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); |
| if (client) |
| 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("i2c-core: attempting to delete unregistered " |
| "adapter [%s]\n", adap->name); |
| return; |
| } |
| |
| acpi_i2c_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); |
| |
| /* 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); |
| |
| /* ------------------------------------------------------------------------- */ |
| |
| 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 (unlikely(WARN_ON(!i2c_bus_type.p))) |
| 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("i2c-core: 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("i2c-core: 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); |
| |
| #if IS_ENABLED(CONFIG_OF_DYNAMIC) |
| static int of_i2c_notify(struct notifier_block *nb, unsigned long action, |
| void *arg) |
| { |
| struct of_reconfig_data *rd = arg; |
| struct i2c_adapter *adap; |
| struct i2c_client *client; |
| |
| switch (of_reconfig_get_state_change(action, rd)) { |
| case OF_RECONFIG_CHANGE_ADD: |
| adap = of_find_i2c_adapter_by_node(rd->dn->parent); |
| if (adap == NULL) |
| return NOTIFY_OK; /* not for us */ |
| |
| if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { |
| put_device(&adap->dev); |
| return NOTIFY_OK; |
| } |
| |
| client = of_i2c_register_device(adap, rd->dn); |
| put_device(&adap->dev); |
| |
| if (IS_ERR(client)) { |
| pr_err("%s: failed to create for '%s'\n", |
| __func__, rd->dn->full_name); |
| return notifier_from_errno(PTR_ERR(client)); |
| } |
| break; |
| case OF_RECONFIG_CHANGE_REMOVE: |
| /* already depopulated? */ |
| if (!of_node_check_flag(rd->dn, OF_POPULATED)) |
| return NOTIFY_OK; |
| |
| /* find our device by node */ |
| client = of_find_i2c_device_by_node(rd->dn); |
| if (client == NULL) |
| return NOTIFY_OK; /* no? not meant for us */ |
| |
| /* unregister takes one ref away */ |
| i2c_unregister_device(client); |
| |
| /* and put the reference of the find */ |
| put_device(&client->dev); |
| break; |
| } |
| |
| return NOTIFY_OK; |
| } |
| static struct notifier_block i2c_of_notifier = { |
| .notifier_call = of_i2c_notify, |
| }; |
| #else |
| extern struct notifier_block i2c_of_notifier; |
| #endif /* CONFIG_OF_DYNAMIC */ |
| |
| 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; |
| #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)); |
| |
| return 0; |
| |
| class_err: |
| #ifdef CONFIG_I2C_COMPAT |
| class_compat_unregister(i2c_adapter_compat_class); |
| bus_err: |
| #endif |
| bus_unregister(&i2c_bus_type); |
| return retval; |
| } |
| |
| static void __exit i2c_exit(void) |
| { |
| 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 (adap->quirks && i2c_check_for_quirks(adap, msgs, num)) |
| return -EOPNOTSUPP; |
| |
| /* i2c_trace_msg 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_key_false(&i2c_trace_msg)) { |
| 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_key_false(&i2c_trace_msg)) { |
| 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, i, 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_adapter(adap); |
| if (!ret) |
| /* I2C activity is ongoing. */ |
| return -EAGAIN; |
| } else { |
| i2c_lock_adapter(adap); |
| } |
| |
| ret = __i2c_transfer(adap, msgs, num); |
| i2c_unlock_adapter(adap); |
| |
| return ret; |
| } else { |
| dev_dbg(&adap->dev, "I2C level transfers not supported\n"); |
| return -EOPNOTSUPP; |
| } |
| } |
| EXPORT_SYMBOL(i2c_transfer); |
| |
| /** |
| * i2c_master_send - issue a single I2C message in master transmit mode |
| * @client: Handle to slave device |
| * @buf: Data that will be written to the slave |
| * @count: How many bytes to write, must be less than 64k since msg.len is u16 |
| * |
| * Returns negative errno, or else the number of bytes written. |
| */ |
| int i2c_master_send(const struct i2c_client *client, const char *buf, int count) |
| { |
| int ret; |
| struct i2c_adapter *adap = client->adapter; |
| struct i2c_msg msg; |
| |
| msg.addr = client->addr; |
| msg.flags = client->flags & I2C_M_TEN; |
| msg.len = count; |
| msg.buf = (char *)buf; |
| |
| ret = i2c_transfer(adap, &msg, 1); |
| |
| /* |
| * If everything went ok (i.e. 1 msg transmitted), return #bytes |
| * transmitted, else error code. |
| */ |
| return (ret == 1) ? count : ret; |
| } |
| EXPORT_SYMBOL(i2c_master_send); |
| |
| /** |
| * i2c_master_recv - issue a single I2C message in master receive mode |
| * @client: Handle to slave device |
| * @buf: Where to store data read from slave |
| * @count: How many bytes to read, must be less than 64k since msg.len is u16 |
| * |
| * Returns negative errno, or else the number of bytes read. |
| */ |
| int i2c_master_recv(const struct i2c_client *client, char *buf, int count) |
| { |
| struct i2c_adapter *adap = client->adapter; |
| struct i2c_msg msg; |
| int ret; |
| |
| msg.addr = client->addr; |
| msg.flags = client->flags & I2C_M_TEN; |
| msg.flags |= I2C_M_RD; |
| msg.len = count; |
| msg.buf = buf; |
| |
| ret = i2c_transfer(adap, &msg, 1); |
| |
| /* |
| * If everything went ok (i.e. 1 msg received), return #bytes received, |
| * else error code. |
| */ |
| return (ret == 1) ? count : ret; |
| } |
| EXPORT_SYMBOL(i2c_master_recv); |
| |
| /* ---------------------------------------------------- |
| * 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); |
| |
| /* The SMBus parts */ |
| |
| #define POLY (0x1070U << 3) |
| static u8 crc8(u16 data) |
| { |
| int i; |
| |
| for (i = 0; i < 8; i++) { |
| if (data & 0x8000) |
| data = data ^ POLY; |
| data = data << 1; |
| } |
| return (u8)(data >> 8); |
| } |
| |
| /* Incremental CRC8 over count bytes in the array pointed to by p */ |
| static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) |
| { |
| int i; |
| |
| for (i = 0; i < count; i++) |
| crc = crc8((crc ^ p[i]) << 8); |
| return crc; |
| } |
| |
| /* Assume a 7-bit address, which is reasonable for SMBus */ |
| static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) |
| { |
| /* The address will be sent first */ |
| u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); |
| pec = i2c_smbus_pec(pec, &addr, 1); |
| |
| /* The data buffer follows */ |
| return i2c_smbus_pec(pec, msg->buf, msg->len); |
| } |
| |
| /* Used for write only transactions */ |
| static inline void i2c_smbus_add_pec(struct i2c_msg *msg) |
| { |
| msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
| msg->len++; |
| } |
| |
| /* Return <0 on CRC error |
| If there was a write before this read (most cases) we need to take the |
| partial CRC from the write part into account. |
| Note that this function does modify the message (we need to decrease the |
| message length to hide the CRC byte from the caller). */ |
| static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) |
| { |
| u8 rpec = msg->buf[--msg->len]; |
| cpec = i2c_smbus_msg_pec(cpec, msg); |
| |
| if (rpec != cpec) { |
| pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", |
| rpec, cpec); |
| return -EBADMSG; |
| } |
| return 0; |
| } |
| |
| /** |
| * i2c_smbus_read_byte - SMBus "receive byte" protocol |
| * @client: Handle to slave device |
| * |
| * This executes the SMBus "receive byte" protocol, returning negative errno |
| * else the byte received from the device. |
| */ |
| s32 i2c_smbus_read_byte(const struct i2c_client *client) |
| { |
| union i2c_smbus_data data; |
| int status; |
| |
| status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
| I2C_SMBUS_READ, 0, |
| I2C_SMBUS_BYTE, &data); |
| return (status < 0) ? status : data.byte; |
| } |
| EXPORT_SYMBOL(i2c_smbus_read_byte); |
| |
| /** |
| * i2c_smbus_write_byte - SMBus "send byte" protocol |
| * @client: Handle to slave device |
| * @value: Byte to be sent |
| * |
| * This executes the SMBus "send byte" protocol, returning negative errno |
| * else zero on success. |
| */ |
| s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value) |
| { |
| return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
| I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
| } |
| EXPORT_SYMBOL(i2c_smbus_write_byte); |
| |
| /** |
| * i2c_smbus_read_byte_data - SMBus "read byte" protocol |
| * @client: Handle to slave device |
| * @command: Byte interpreted by slave |
| * |
| * This executes the SMBus "read byte" protocol, returning negative errno |
| * else a data byte received from the device. |
| */ |
| s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command) |
| { |
| union i2c_smbus_data data; |
| int status; |
| |
| status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
| I2C_SMBUS_READ, command, |
| I2C_SMBUS_BYTE_DATA, &data); |
| return (status < 0) ? status : data.byte; |
| } |
| EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
| |
| /** |
| * i2c_smbus_write_byte_data - SMBus "write byte" protocol |
| * @client: Handle to slave device |
| * @command: Byte interpreted by slave |
| * @value: Byte being written |
| * |
| * This executes the SMBus "write byte" protocol, returning negative errno |
| * else zero on success. |
| */ |
| s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command, |
| u8 value) |
| { |
| union i2c_smbus_data data; |
| data.byte = value; |
| return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
| I2C_SMBUS_WRITE, command, |
| I2C_SMBUS_BYTE_DATA, &data); |
| } |
| EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
| |
| /** |
| * i2c_smbus_read_word_data - SMBus "read word" protocol |
| * @client: Handle to slave device |
| * @command: Byte interpreted by slave |
| * |
| * This executes the SMBus "read word" protocol, returning negative errno |
| * else a 16-bit unsigned "word" received from the device. |
| */ |
| s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command) |
| { |
| union i2c_smbus_data data; |
| int status; |
| |
| status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
| I2C_SMBUS_READ, command, |
| I2C_SMBUS_WORD_DATA, &data); |
| return (status < 0) ? status : data.word; |
| } |
| EXPORT_SYMBOL(i2c_smbus_read_word_data); |
| |
| /** |
| * i2c_smbus_write_word_data - SMBus "write word" protocol |
| * @client: Handle to slave device |
| * @command: Byte interpreted by slave |
| * @value: 16-bit "word" being written |
| * |
| * This executes the SMBus "write word" protocol, returning negative errno |
| * else zero on success. |
| */ |
| s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command, |
| u16 value) |
| { |
| union i2c_smbus_data data; |
| data.word = value; |
| return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
| I2C_SMBUS_WRITE, command, |
| I2C_SMBUS_WORD_DATA, &data); |
| } |
| EXPORT_SYMBOL(i2c_smbus_write_word_data); |
| |
| /** |
| * i2c_smbus_read_block_data - SMBus "block read" protocol |
| * @client: Handle to slave device |
| * @command: Byte interpreted by slave |
| * @values: Byte array into which data will be read; big enough to hold |
| * the data returned by the slave. SMBus allows at most 32 bytes. |
| * |
| * This executes the SMBus "block read" protocol, returning negative errno |
| * else the number of data bytes in the slave's response. |
| * |
| * Note that using this function requires that the client's adapter support |
| * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers |
| * support this; its emulation through I2C messaging relies on a specific |
| * mechanism (I2C_M_RECV_LEN) which may not be implemented. |
| */ |
| s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command, |
| u8 *values) |
| { |
| union i2c_smbus_data data; |
| int status; |
| |
| status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
| I2C_SMBUS_READ, command, |
| I2C_SMBUS_BLOCK_DATA, &data); |
| if (status) |
| return status; |
| |
| memcpy(values, &data.block[1], data.block[0]); |
| return data.block[0]; |
| } |
| EXPORT_SYMBOL(i2c_smbus_read_block_data); |
| |
| /** |
| * i2c_smbus_write_block_data - SMBus "block write" protocol |
| * @client: Handle to slave device |
| * @command: Byte interpreted by slave |
| * @length: Size of data block; SMBus allows at most 32 bytes |
| * @values: Byte array which will be written. |
| * |
| * This executes the SMBus "block write" protocol, returning negative errno |
| * else zero on success. |
| */ |
| s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command, |
| u8 length, const u8 *values) |
| { |
| union i2c_smbus_data data; |
| |
| if (length > I2C_SMBUS_BLOCK_MAX) |
| length = I2C_SMBUS_BLOCK_MAX; |
| data.block[0] = length; |
| memcpy(&data.block[1], values, length); |
| return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
| I2C_SMBUS_WRITE, command, |
| I2C_SMBUS_BLOCK_DATA, &data); |
| } |
| EXPORT_SYMBOL(i2c_smbus_write_block_data); |
| |
| /* Returns the number of read bytes */ |
| s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command, |
| u8 length, u8 *values) |
| { |
| union i2c_smbus_data data; |
| int status; |
| |
| if (length > I2C_SMBUS_BLOCK_MAX) |
| length = I2C_SMBUS_BLOCK_MAX; |
| data.block[0] = length; |
| status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
| I2C_SMBUS_READ, command, |
| I2C_SMBUS_I2C_BLOCK_DATA, &data); |
| if (status < 0) |
| return status; |
| |
| memcpy(values, &data.block[1], data.block[0]); |
| return data.block[0]; |
| } |
| EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
| |
| s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command, |
| u8 length, const u8 *values) |
| { |
| union i2c_smbus_data data; |
| |
| if (length > I2C_SMBUS_BLOCK_MAX) |
| length = I2C_SMBUS_BLOCK_MAX; |
| data.block[0] = length; |
| memcpy(data.block + 1, values, length); |
| return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
| I2C_SMBUS_WRITE, command, |
| I2C_SMBUS_I2C_BLOCK_DATA, &data); |
| } |
| EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
| |
| /* Simulate a SMBus command using the i2c protocol |
| No checking of parameters is done! */ |
| static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, |
| unsigned short flags, |
| char read_write, u8 command, int size, |
| union i2c_smbus_data *data) |
| { |
| /* So we need to generate a series of msgs. In the case of writing, we |
| need to use only one message; when reading, we need two. We initialize |
| most things with sane defaults, to keep the code below somewhat |
| simpler. */ |
| unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
| unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; |
| int num = read_write == I2C_SMBUS_READ ? 2 : 1; |
| int i; |
| u8 partial_pec = 0; |
| int status; |
| struct i2c_msg msg[2] = { |
| { |
| .addr = addr, |
| .flags = flags, |
| .len = 1, |
| .buf = msgbuf0, |
| }, { |
| .addr = addr, |
| .flags = flags | I2C_M_RD, |
| .len = 0, |
| .buf = msgbuf1, |
| }, |
| }; |
| |
| msgbuf0[0] = command; |
| switch (size) { |
| case I2C_SMBUS_QUICK: |
| msg[0].len = 0; |
| /* Special case: The read/write field is used as data */ |
| msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
| I2C_M_RD : 0); |
| num = 1; |
| break; |
| case I2C_SMBUS_BYTE: |
| if (read_write == I2C_SMBUS_READ) { |
| /* Special case: only a read! */ |
| msg[0].flags = I2C_M_RD | flags; |
| num = 1; |
| } |
| break; |
| case I2C_SMBUS_BYTE_DATA: |
| if (read_write == I2C_SMBUS_READ) |
| msg[1].len = 1; |
| else { |
| msg[0].len = 2; |
| msgbuf0[1] = data->byte; |
| } |
| break; |
| case I2C_SMBUS_WORD_DATA: |
| if (read_write == I2C_SMBUS_READ) |
| msg[1].len = 2; |
| else { |
| msg[0].len = 3; |
| msgbuf0[1] = data->word & 0xff; |
| msgbuf0[2] = data->word >> 8; |
| } |
| break; |
| case I2C_SMBUS_PROC_CALL: |
| num = 2; /* Special case */ |
| read_write = I2C_SMBUS_READ; |
| msg[0].len = 3; |
| msg[1].len = 2; |
| msgbuf0[1] = data->word & 0xff; |
| msgbuf0[2] = data->word >> 8; |
| break; |
| case I2C_SMBUS_BLOCK_DATA: |
| if (read_write == I2C_SMBUS_READ) { |
| msg[1].flags |= I2C_M_RECV_LEN; |
| msg[1].len = 1; /* block length will be added by |
| the underlying bus driver */ |
| } else { |
| msg[0].len = data->block[0] + 2; |
| if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { |
| dev_err(&adapter->dev, |
| "Invalid block write size %d\n", |
| data->block[0]); |
| return -EINVAL; |
| } |
| for (i = 1; i < msg[0].len; i++) |
| msgbuf0[i] = data->block[i-1]; |
| } |
| break; |
| case I2C_SMBUS_BLOCK_PROC_CALL: |
| num = 2; /* Another special case */ |
| read_write = I2C_SMBUS_READ; |
| if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { |
| dev_err(&adapter->dev, |
| "Invalid block write size %d\n", |
| data->block[0]); |
| return -EINVAL; |
| } |
| msg[0].len = data->block[0] + 2; |
| for (i = 1; i < msg[0].len; i++) |
| msgbuf0[i] = data->block[i-1]; |
| msg[1].flags |= I2C_M_RECV_LEN; |
| msg[1].len = 1; /* block length will be added by |
| the underlying bus driver */ |
| break; |
| case I2C_SMBUS_I2C_BLOCK_DATA: |
| if (read_write == I2C_SMBUS_READ) { |
| msg[1].len = data->block[0]; |
| } else { |
| msg[0].len = data->block[0] + 1; |
| if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
| dev_err(&adapter->dev, |
| "Invalid block write size %d\n", |
| data->block[0]); |
| return -EINVAL; |
| } |
| for (i = 1; i <= data->block[0]; i++) |
| msgbuf0[i] = data->block[i]; |
| } |
| break; |
| default: |
| dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
| return -EOPNOTSUPP; |
| } |
| |
| i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
| && size != I2C_SMBUS_I2C_BLOCK_DATA); |
| if (i) { |
| /* Compute PEC if first message is a write */ |
| if (!(msg[0].flags & I2C_M_RD)) { |
| if (num == 1) /* Write only */ |
| i2c_smbus_add_pec(&msg[0]); |
| else /* Write followed by read */ |
| partial_pec = i2c_smbus_msg_pec(0, &msg[0]); |
| } |
| /* Ask for PEC if last message is a read */ |
| if (msg[num-1].flags & I2C_M_RD) |
| msg[num-1].len++; |
| } |
| |
| status = i2c_transfer(adapter, msg, num); |
| if (status < 0) |
| return status; |
| |
| /* Check PEC if last message is a read */ |
| if (i && (msg[num-1].flags & I2C_M_RD)) { |
| status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
| if (status < 0) |
| return status; |
| } |
| |
| if (read_write == I2C_SMBUS_READ) |
| switch (size) { |
| case I2C_SMBUS_BYTE: |
| data->byte = msgbuf0[0]; |
| break; |
| case I2C_SMBUS_BYTE_DATA: |
| data->byte = msgbuf1[0]; |
| break; |
| case I2C_SMBUS_WORD_DATA: |
| case I2C_SMBUS_PROC_CALL: |
| data->word = msgbuf1[0] | (msgbuf1[1] << 8); |
| break; |
| case I2C_SMBUS_I2C_BLOCK_DATA: |
| for (i = 0; i < data->block[0]; i++) |
| data->block[i+1] = msgbuf1[i]; |
| break; |
| case I2C_SMBUS_BLOCK_DATA: |
| case I2C_SMBUS_BLOCK_PROC_CALL: |
| for (i = 0; i < msgbuf1[0] + 1; i++) |
| data->block[i] = msgbuf1[i]; |
| break; |
| } |
| return 0; |
| } |
| |
| /** |
| * i2c_smbus_xfer - execute SMBus protocol operations |
| * @adapter: Handle to I2C bus |
| * @addr: Address of SMBus slave on that bus |
| * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) |
| * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE |
| * @command: Byte interpreted by slave, for protocols which use such bytes |
| * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL |
| * @data: Data to be read or written |
| * |
| * This executes an SMBus protocol operation, and returns a negative |
| * errno code else zero on success. |
| */ |
| s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
| char read_write, u8 command, int protocol, |
| union i2c_smbus_data *data) |
| { |
| unsigned long orig_jiffies; |
| int try; |
| s32 res; |
| |
| /* If enabled, the following two tracepoints are conditional on |
| * read_write and protocol. |
| */ |
| trace_smbus_write(adapter, addr, flags, read_write, |
| command, protocol, data); |
| trace_smbus_read(adapter, addr, flags, read_write, |
| command, protocol); |
| |
| flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB; |
| |
| if (adapter->algo->smbus_xfer) { |
| i2c_lock_adapter(adapter); |
| |
| /* Retry automatically on arbitration loss */ |
| orig_jiffies = jiffies; |
| for (res = 0, try = 0; try <= adapter->retries; try++) { |
| res = adapter->algo->smbus_xfer(adapter, addr, flags, |
| read_write, command, |
| protocol, data); |
| if (res != -EAGAIN) |
| break; |
| if (time_after(jiffies, |
| orig_jiffies + adapter->timeout)) |
| break; |
| } |
| i2c_unlock_adapter(adapter); |
| |
| if (res != -EOPNOTSUPP || !adapter->algo->master_xfer) |
| goto trace; |
| /* |
| * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't |
| * implement native support for the SMBus operation. |
| */ |
| } |
| |
| res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, |
| command, protocol, data); |
| |
| trace: |
| /* If enabled, the reply tracepoint is conditional on read_write. */ |
| trace_smbus_reply(adapter, addr, flags, read_write, |
| command, protocol, data); |
| trace_smbus_result(adapter, addr, flags, read_write, |
| command, protocol, res); |
| |
| return res; |
| } |
| EXPORT_SYMBOL(i2c_smbus_xfer); |
| |
| /** |
| * i2c_smbus_read_i2c_block_data_or_emulated - read block or emulate |
| * @client: Handle to slave device |
| * @command: Byte interpreted by slave |
| * @length: Size of data block; SMBus allows at most I2C_SMBUS_BLOCK_MAX bytes |
| * @values: Byte array into which data will be read; big enough to hold |
| * the data returned by the slave. SMBus allows at most |
| * I2C_SMBUS_BLOCK_MAX bytes. |
| * |
| * This executes the SMBus "block read" protocol if supported by the adapter. |
| * If block read is not supported, it emulates it using either word or byte |
| * read protocols depending on availability. |
| * |
| * The addresses of the I2C slave device that are accessed with this function |
| * must be mapped to a linear region, so that a block read will have the same |
| * effect as a byte read. Before using this function you must double-check |
| * if the I2C slave does support exchanging a block transfer with a byte |
| * transfer. |
| */ |
| s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, |
| u8 command, u8 length, u8 *values) |
| { |
| u8 i = 0; |
| int status; |
| |
| if (length > I2C_SMBUS_BLOCK_MAX) |
| length = I2C_SMBUS_BLOCK_MAX; |
| |
| if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) |
| return i2c_smbus_read_i2c_block_data(client, command, length, values); |
| |
| if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) |
| return -EOPNOTSUPP; |
| |
| if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)) { |
| while ((i + 2) <= length) { |
| status = i2c_smbus_read_word_data(client, command + i); |
| if (status < 0) |
| return status; |
| values[i] = status & 0xff; |
| values[i + 1] = status >> 8; |
| i += 2; |
| } |
| } |
| |
| while (i < length) { |
| status = i2c_smbus_read_byte_data(client, command + i); |
| if (status < 0) |
| return status; |
| values[i] = status; |
| i++; |
| } |
| |
| return i; |
| } |
| EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data_or_emulated); |
| |
| #if IS_ENABLED(CONFIG_I2C_SLAVE) |
| int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb) |
| { |
| int ret; |
| |
| if (!client || !slave_cb) { |
| WARN(1, "insufficent data\n"); |
| return -EINVAL; |
| } |
| |
| if (!(client->flags & I2C_CLIENT_SLAVE)) |
| dev_warn(&client->dev, "%s: client slave flag not set. You might see address collisions\n", |
| __func__); |
| |
| if (!(client->flags & I2C_CLIENT_TEN)) { |
| /* Enforce stricter address checking */ |
| ret = i2c_check_7bit_addr_validity_strict(client->addr); |
| if (ret) { |
| dev_err(&client->dev, "%s: invalid address\n", __func__); |
| return ret; |
| } |
| } |
|