diff options
Diffstat (limited to 'drivers/i2c/i2c-core.c')
| -rw-r--r-- | drivers/i2c/i2c-core.c | 3831 |
1 files changed, 0 insertions, 3831 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c deleted file mode 100644 index 82576aaccc90..000000000000 --- a/drivers/i2c/i2c-core.c +++ /dev/null @@ -1,3831 +0,0 @@ -/* 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> - */ - -#define pr_fmt(fmt) "i2c-core: " fmt - -#include <dt-bindings/i2c/i2c.h> -#include <linux/uaccess.h> -#include <linux/acpi.h> -#include <linux/clk/clk-conf.h> -#include <linux/completion.h> -#include <linux/delay.h> -#include <linux/err.h> -#include <linux/errno.h> -#include <linux/gpio.h> -#include <linux/hardirq.h> -#include <linux/i2c.h> -#include <linux/idr.h> -#include <linux/init.h> -#include <linux/irqflags.h> -#include <linux/jump_label.h> -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/mutex.h> -#include <linux/of_device.h> -#include <linux/of.h> -#include <linux/of_irq.h> -#include <linux/pm_domain.h> -#include <linux/pm_runtime.h> -#include <linux/pm_wakeirq.h> -#include <linux/property.h> -#include <linux/rwsem.h> -#include <linux/slab.h> - -#include "i2c-core.h" - -#define CREATE_TRACE_POINTS -#include <trace/events/i2c.h> - -#define I2C_ADDR_OFFSET_TEN_BIT 0xa000 -#define I2C_ADDR_OFFSET_SLAVE 0x1000 - -#define I2C_ADDR_7BITS_MAX 0x77 -#define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1) - -/* core_lock protects i2c_adapter_idr, and guarantees - that device detection, deletion of detected devices, and attach_adapter - calls are serialized */ -static DEFINE_MUTEX(core_lock); -static DEFINE_IDR(i2c_adapter_idr); - -static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); - -static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE; -static bool is_registered; - -int i2c_transfer_trace_reg(void) -{ - static_key_slow_inc(&i2c_trace_msg); - return 0; -} - -void i2c_transfer_trace_unreg(void) -{ - static_key_slow_dec(&i2c_trace_msg); -} - -#if defined(CONFIG_ACPI) -struct i2c_acpi_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 i2c_acpi_lookup { - struct i2c_board_info *info; - acpi_handle adapter_handle; - acpi_handle device_handle; - acpi_handle search_handle; - int n; - int index; - u32 speed; - u32 min_speed; -}; - -static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data) -{ - struct i2c_acpi_lookup *lookup = data; - struct i2c_board_info *info = lookup->info; - struct acpi_resource_i2c_serialbus *sb; - 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; - - if (lookup->index != -1 && lookup->n++ != lookup->index) - return 1; - - status = acpi_get_handle(lookup->device_handle, - sb->resource_source.string_ptr, - &lookup->adapter_handle); - if (!ACPI_SUCCESS(status)) - return 1; - - info->addr = sb->slave_address; - lookup->speed = sb->connection_speed; - if (sb->access_mode == ACPI_I2C_10BIT_MODE) - info->flags |= I2C_CLIENT_TEN; - - return 1; -} - -static int i2c_acpi_do_lookup(struct acpi_device *adev, - struct i2c_acpi_lookup *lookup) -{ - struct i2c_board_info *info = lookup->info; - struct list_head resource_list; - int ret; - - if (acpi_bus_get_status(adev) || !adev->status.present || - acpi_device_enumerated(adev)) - return -EINVAL; - - memset(info, 0, sizeof(*info)); - lookup->device_handle = acpi_device_handle(adev); - - /* Look up for I2cSerialBus resource */ - INIT_LIST_HEAD(&resource_list); - ret = acpi_dev_get_resources(adev, &resource_list, - i2c_acpi_fill_info, lookup); - acpi_dev_free_resource_list(&resource_list); - - if (ret < 0 || !info->addr) - return -EINVAL; - - return 0; -} - -static int i2c_acpi_get_info(struct acpi_device *adev, - struct i2c_board_info *info, - struct i2c_adapter *adapter, - acpi_handle *adapter_handle) -{ - struct list_head resource_list; - struct resource_entry *entry; - struct i2c_acpi_lookup lookup; - int ret; - - memset(&lookup, 0, sizeof(lookup)); - lookup.info = info; - lookup.index = -1; - - ret = i2c_acpi_do_lookup(adev, &lookup); - if (ret) - return ret; - - if (adapter) { - /* The adapter must match the one in I2cSerialBus() connector */ - if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle) - return -ENODEV; - } else { - struct acpi_device *adapter_adev; - - /* The adapter must be present */ - if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev)) - return -ENODEV; - if (acpi_bus_get_status(adapter_adev) || - !adapter_adev->status.present) - return -ENODEV; - } - - info->fwnode = acpi_fwnode_handle(adev); - if (adapter_handle) - *adapter_handle = lookup.adapter_handle; - - /* Then fill IRQ number if any */ - INIT_LIST_HEAD(&resource_list); - ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL); - if (ret < 0) - return -EINVAL; - - 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); - - acpi_set_modalias(adev, dev_name(&adev->dev), info->type, - sizeof(info->type)); - - return 0; -} - -static void i2c_acpi_register_device(struct i2c_adapter *adapter, - struct acpi_device *adev, - struct i2c_board_info *info) -{ - adev->power.flags.ignore_parent = true; - acpi_device_set_enumerated(adev); - - 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)); - } -} - -static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level, - void *data, void **return_value) -{ - struct i2c_adapter *adapter = data; - struct acpi_device *adev; - struct i2c_board_info info; - - if (acpi_bus_get_device(handle, &adev)) - return AE_OK; - - if (i2c_acpi_get_info(adev, &info, adapter, NULL)) - return AE_OK; - - i2c_acpi_register_device(adapter, adev, &info); - - return AE_OK; -} - -#define I2C_ACPI_MAX_SCAN_DEPTH 32 - -/** - * i2c_acpi_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 i2c_acpi_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, - I2C_ACPI_MAX_SCAN_DEPTH, - i2c_acpi_add_device, NULL, - adap, NULL); - if (ACPI_FAILURE(status)) - dev_warn(&adap->dev, "failed to enumerate I2C slaves\n"); -} - -static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level, - void *data, void **return_value) -{ - struct i2c_acpi_lookup *lookup = data; - struct acpi_device *adev; - - if (acpi_bus_get_device(handle, &adev)) - return AE_OK; - - if (i2c_acpi_do_lookup(adev, lookup)) - return AE_OK; - - if (lookup->search_handle != lookup->adapter_handle) - return AE_OK; - - if (lookup->speed <= lookup->min_speed) - lookup->min_speed = lookup->speed; - - return AE_OK; -} - -/** - * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI - * @dev: The device owning the bus - * - * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves - * devices connected to this bus and use the speed of slowest device. - * - * Returns the speed in Hz or zero - */ -u32 i2c_acpi_find_bus_speed(struct device *dev) -{ - struct i2c_acpi_lookup lookup; - struct i2c_board_info dummy; - acpi_status status; - - if (!has_acpi_companion(dev)) - return 0; - - memset(&lookup, 0, sizeof(lookup)); - lookup.search_handle = ACPI_HANDLE(dev); - lookup.min_speed = UINT_MAX; - lookup.info = &dummy; - lookup.index = -1; - - status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, - I2C_ACPI_MAX_SCAN_DEPTH, - i2c_acpi_lookup_speed, NULL, - &lookup, NULL); - - if (ACPI_FAILURE(status)) { - dev_warn(dev, "unable to find I2C bus speed from ACPI\n"); - return 0; - } - - return lookup.min_speed != UINT_MAX ? lookup.min_speed : 0; -} -EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed); - -static int i2c_acpi_match_adapter(struct device *dev, void *data) -{ - struct i2c_adapter *adapter = i2c_verify_adapter(dev); - - if (!adapter) - return 0; - - return ACPI_HANDLE(dev) == (acpi_handle)data; -} - -static int i2c_acpi_match_device(struct device *dev, void *data) -{ - return ACPI_COMPANION(dev) == data; -} - -static struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle) -{ - struct device *dev; - - dev = bus_find_device(&i2c_bus_type, NULL, handle, - i2c_acpi_match_adapter); - return dev ? i2c_verify_adapter(dev) : NULL; -} - -static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev) -{ - struct device *dev; - - dev = bus_find_device(&i2c_bus_type, NULL, adev, i2c_acpi_match_device); - return dev ? i2c_verify_client(dev) : NULL; -} - -static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value, - void *arg) -{ - struct acpi_device *adev = arg; - struct i2c_board_info info; - acpi_handle adapter_handle; - struct i2c_adapter *adapter; - struct i2c_client *client; - - switch (value) { - case ACPI_RECONFIG_DEVICE_ADD: - if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle)) - break; - - adapter = i2c_acpi_find_adapter_by_handle(adapter_handle); - if (!adapter) - break; - - i2c_acpi_register_device(adapter, adev, &info); - break; - case ACPI_RECONFIG_DEVICE_REMOVE: - if (!acpi_device_enumerated(adev)) - break; - - client = i2c_acpi_find_client_by_adev(adev); - if (!client) - break; - - i2c_unregister_device(client); - put_device(&client->dev); - break; - } - - return NOTIFY_OK; -} - -static struct notifier_block i2c_acpi_notifier = { - .notifier_call = i2c_acpi_notify, -}; - -/** - * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource - * @dev: Device owning the ACPI resources to get the client from - * @index: Index of ACPI resource to get - * @info: describes the I2C device; note this is modified (addr gets set) - * Context: can sleep - * - * By default the i2c subsys creates an i2c-client for the first I2cSerialBus - * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus - * resources, in that case this function can be used to create an i2c-client - * for other I2cSerialBus resources in the Current Resource Settings table. - * - * Also see i2c_new_device, which this function calls to create the i2c-client. - * - * Returns a pointer to the new i2c-client, or NULL if the adapter is not found. - */ -struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, - struct i2c_board_info *info) -{ - struct i2c_acpi_lookup lookup; - struct i2c_adapter *adapter; - struct acpi_device *adev; - LIST_HEAD(resource_list); - int ret; - - adev = ACPI_COMPANION(dev); - if (!adev) - return NULL; - - memset(&lookup, 0, sizeof(lookup)); - lookup.info = info; - lookup.device_handle = acpi_device_handle(adev); - lookup.index = index; - - ret = acpi_dev_get_resources(adev, &resource_list, - i2c_acpi_fill_info, &lookup); - acpi_dev_free_resource_list(&resource_list); - - if (ret < 0 || !info->addr) - return NULL; - - adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle); - if (!adapter) - return NULL; - - return i2c_new_device(adapter, info); -} -EXPORT_SYMBOL_GPL(i2c_acpi_new_device); -#else /* CONFIG_ACPI */ -static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { } -extern struct notifier_block i2c_acpi_notifier; -#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 -i2c_acpi_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 i2c_acpi_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: - dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n", - accessor_type, client->addr); - ret = AE_BAD_PARAMETER; - goto err; - } - - gsb->status = status; - - err: - kfree(client); - ACPI_FREE(ares); - return ret; -} - - -static int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) -{ - acpi_handle handle; - struct i2c_acpi_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 i2c_acpi_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, - &i2c_acpi_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 i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) -{ - acpi_handle handle; - struct i2c_acpi_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, - &i2c_acpi_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 i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) -{ } - -static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) -{ return 0; } -#endif /* CONFIG_ACPI_I2C_OPREGION */ - -/* ------------------------------------------------------------------------- */ - -const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, - const struct i2c_client *client) -{ - if (!(id && client)) - return NULL; - - while (id->name[0]) { - if (strcmp(client->name, id->name) == 0) - return id; - id++; - } - return NULL; -} -EXPORT_SYMBOL_GPL(i2c_match_id); - -static int i2c_device_match(struct device *dev, struct device_driver *drv) -{ - struct i2c_client *client = i2c_verify_client(dev); - struct i2c_driver *driver; - - - /* Attempt an OF style match */ - if (i2c_of_match_device(drv->of_match_table, client)) - return 1; - - /* Then ACPI style match */ - if (acpi_driver_match_device(dev, drv)) - return 1; - - driver = to_i2c_driver(drv); - - /* Finally an I2C match */ - if (i2c_match_id(driver->id_table, client)) - return 1; - - return 0; -} - -static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) -{ - struct i2c_client *client = to_i2c_client(dev); - int rc; - - rc = acpi_device_uevent_modalias(dev, env); - if (rc != -ENODEV) - return rc; - - return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name); -} - -/* i2c bus recovery routines */ -static int get_scl_gpio_value(struct i2c_adapter *adap) -{ - return 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 void i2c_init_recovery(struct i2c_adapter *adap) -{ - struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; - char *err_str; - - if (!bri) - return; - - if (!bri->recover_bus) { - err_str = "no recover_bus() found"; - goto err; - } - - /* Generic GPIO recovery */ - if (bri->recover_bus == i2c_generic_gpio_recovery) { - if (!gpio_is_valid(bri->scl_gpio)) { - err_str = "invalid SCL gpio"; - goto err; - } - - 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->recover_bus == i2c_generic_scl_recovery) { - /* Generic SCL recovery */ - if (!bri->set_scl || !bri->get_scl) { - err_str = "no {get|set}_scl() found"; - goto err; - } - } - - return; - err: - dev_err(&adap->dev, "Not using recovery: %s\n", err_str); - adap->bus_recovery_info = NULL; -} - -static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client) -{ - struct i2c_adapter *adap = client->adapter; - unsigned int irq; - - if (!adap->host_notify_domain) - return -ENXIO; - - if (client->flags & I2C_CLIENT_TEN) - return -EINVAL; - - irq = irq_find_mapping(adap->host_notify_domain, client->addr); - if (!irq) - irq = irq_create_mapping(adap->host_notify_domain, - client->addr); - - return irq > 0 ? irq : -ENXIO; -} - -static int i2c_device_probe(struct device *dev) -{ - struct i2c_client *client = i2c_verify_client(dev); - struct i2c_driver *driver; - int status; - - if (!client) - return 0; - - driver = to_i2c_driver(dev->driver); - - if (!client->irq && !driver->disable_i2c_core_irq_mapping) { - int irq = -ENOENT; - - if (client->flags & I2C_CLIENT_HOST_NOTIFY) { - dev_dbg(dev, "Using Host Notify IRQ\n"); - irq = i2c_smbus_host_notify_to_irq(client); - } else if (dev->of_node) { - irq = of_irq_get_byname(dev->of_node, "irq"); - if (irq == -EINVAL || irq == -ENODATA) - irq = of_irq_get(dev->of_node, 0); - } else if (ACPI_COMPANION(dev)) { - irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0); - } - if (irq == -EPROBE_DEFER) - return irq; - - if (irq < 0) - irq = 0; - - client->irq = irq; - } - - /* - * An I2C ID table is not mandatory, if and only if, a suitable Device - * Tree match table entry is supplied for the probing device. - */ - if (!driver->id_table && - !i2c_of_match_device(dev->driver->of_match_table, client)) - return -ENODEV; - - if (client->flags & I2C_CLIENT_WAKE) { - int wakeirq = -ENOENT; - - if (dev->of_node) { - wakeirq = of_irq_get_byname(dev->of_node, "wakeup"); - if (wakeirq == -EPROBE_DEFER) - return wakeirq; - } - - device_init_wakeup(&client->dev, true); - - if (wakeirq > 0 && wakeirq != client->irq) - status = dev_pm_set_dedicated_wake_irq(dev, wakeirq); - else if (client->irq > 0) - status = dev_pm_set_wake_irq(dev, client->irq); - else - status = 0; - - if (status) - dev_warn(&client->dev, "failed to set up wakeup irq\n"); - } - - dev_dbg(dev, "probe\n"); - - status = of_clk_set_defaults(dev->of_node, false); - if (status < 0) - goto err_clear_wakeup_irq; - - status = dev_pm_domain_attach(&client->dev, true); - if (status == -EPROBE_DEFER) - goto err_clear_wakeup_irq; - - /* - * When there are no more users of probe(), - * rename probe_new to probe. - */ - if (driver->probe_new) - status = driver->probe_new(client); - else if (driver->probe) - status = driver->probe(client, - i2c_match_id(driver->id_table, client)); - else - status = -EINVAL; - - if (status) - goto err_detach_pm_domain; - - return 0; - -err_detach_pm_domain: - dev_pm_domain_detach(&client->dev, true); -err_clear_wakeup_irq: - dev_pm_clear_wake_irq(&client->dev); - device_init_wakeup(&client->dev, false); - return status; -} - -static int i2c_device_remove(struct device *dev) -{ - struct i2c_client *client = i2c_verify_client(dev); - struct i2c_driver *driver; - int status = 0; - - if (!client || !dev->driver) - return 0; - - driver = to_i2c_driver(dev->driver); - if (driver->remove) { - dev_dbg(dev, "remove\n"); - status = driver->remove(client); - } - - dev_pm_domain_detach(&client->dev, true); - - dev_pm_clear_wake_irq(&client->dev); - device_init_wakeup(&client->dev, false); - - return status; -} - -static void i2c_device_shutdown(struct device *dev) -{ - struct i2c_client *client = i2c_verify_client(dev); - struct i2c_driver *driver; - - if (!client || !dev->driver) - return; - driver = to_i2c_driver(dev->driver); - if (driver->shutdown) - driver->shutdown(client); -} - -static void i2c_client_dev_release(struct device *dev) -{ - kfree(to_i2c_client(dev)); -} - -static ssize_t -show_name(struct device *dev, struct device_attribute *attr, char *buf) -{ - return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? - to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); -} -static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); - -static ssize_t -show_modalias(struct device *dev, struct device_attribute *attr, char *buf) -{ - struct i2c_client *client = to_i2c_client(dev); - int len; - - len = acpi_device_modalias(dev, buf, PAGE_SIZE -1); - if (len != -ENODEV) - return len; - - return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); -} -static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); - -static struct attribute *i2c_dev_attrs[] = { - &dev_attr_name.attr, - /* modalias helps coldplug: modprobe $(cat .../modalias) */ - &dev_attr_modalias.attr, - NULL -}; -ATTRIBUTE_GROUPS(i2c_dev); - -struct bus_type i2c_bus_type = { - .name = "i2c", - .match = i2c_device_match, - .probe = i2c_device_probe, - .remove = i2c_device_remove, - .shutdown = i2c_device_shutdown, -}; -EXPORT_SYMBOL_GPL(i2c_bus_type); - -struct device_type i2c_client_type = { - .groups = i2c_dev_groups, - .uevent = i2c_device_uevent, - .release = i2c_client_dev_release, -}; -EXPORT_SYMBOL_GPL(i2c_client_type); - - -/** - * i2c_verify_client - return parameter as i2c_client, or NULL - * @dev: device, probably from some driver model iterator - * - * When traversing the driver model tree, perhaps using driver model - * iterators like @device_for_each_child(), you can't assume very much - * about the nodes you find. Use this function to avoid oopses caused - * by wrongly treating some non-I2C device as an i2c_client. - */ -struct i2c_client *i2c_verify_client(struct device *dev) -{ - return (dev->type == &i2c_client_type) - ? to_i2c_client(dev) - : NULL; -} -EXPORT_SYMBOL(i2c_verify_client); - - -/* Return a unique address which takes the flags of the client into account */ -static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client) -{ - unsigned short addr = client->addr; - - /* For some client flags, add an arbitrary offset to avoid collisions */ - if (client->flags & I2C_CLIENT_TEN) - addr |= I2C_ADDR_OFFSET_TEN_BIT; - - if (client->flags & I2C_CLIENT_SLAVE) - addr |= I2C_ADDR_OFFSET_SLAVE; - - return addr; -} - -/* This is a permissive address validity check, I2C address map constraints - * are purposely not enforced, except for the general call address. */ -static int i2c_check_addr_validity(unsigned 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_adapter_lock_bus - Get exclusive access to an I2C bus segment - * @adapter: Target I2C bus segment - * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT - * locks only this branch in the adapter tree - */ -static void i2c_adapter_lock_bus(struct i2c_adapter *adapter, - unsigned int flags) -{ - rt_mutex_lock(&adapter->bus_lock); -} - -/** - * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment - * @adapter: Target I2C bus segment - * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT - * trylocks only this branch in the adapter tree - */ -static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter, - unsigned int flags) -{ - return rt_mutex_trylock(&adapter->bus_lock); -} - -/** - * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment - * @adapter: Target I2C bus segment - * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT - * unlocks only this branch in the adapter tree - */ -static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter, - unsigned int flags) -{ - rt_mutex_unlock(&adapter->bus_lock); -} - -static void i2c_dev_set_name(struct i2c_adapter *adap, - struct i2c_client *client) -{ - struct 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)); -} - -static int i2c_dev_irq_from_resources(const struct resource *resources, - unsigned int num_resources) -{ - struct irq_data *irqd; - int i; - - for (i = 0; i < num_resources; i++) { - const struct resource *r = &resources[i]; - - if (resource_type(r) != IORESOURCE_IRQ) - continue; - - if (r->flags & IORESOURCE_BITS) { - irqd = irq_get_irq_data(r->start); - if (!irqd) - break; - - irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); - } - - return r->start; - } - - return 0; -} - -/** - * i2c_new_device - instantiate an i2c device - * @adap: the adapter managing the device - * @info: describes one I2C device; bus_num is ignored - * Context: can sleep - * - * Create an i2c device. Binding is handled through driver model - * probe()/remove() methods. A driver may be bound to this device when we - * return from this function, or any later moment (e.g. maybe hotplugging will - * load the driver module). This call is not appropriate for use by mainboard - * initialization logic, which usually runs during an arch_initcall() long - * before any i2c_adapter could exist. - * - * This returns the new i2c client, which may be saved for later use with - * i2c_unregister_device(); or NULL to indicate an error. - */ -struct i2c_client * -i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) -{ - struct i2c_client *client; - int status; - - client = kzalloc(sizeof *client, GFP_KERNEL); - if (!client) - return NULL; - - client->adapter = adap; - - client->dev.platform_data = info->platform_data; - - if (info->archdata) - client->dev.archdata = *info->archdata; - - client->flags = info->flags; - client->addr = info->addr; - - client->irq = info->irq; - if (!client->irq) - client->irq = i2c_dev_irq_from_resources(info->resources, - info->num_resources); - - strlcpy(client->name, info->type, sizeof(client->name)); - - status = i2c_check_addr_validity(client->addr, client->flags); - if (status) { - dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", - client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); - goto out_err_silent; - } - - /* Check for address business */ - status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client)); - if (status) - goto out_err; - - client->dev.parent = &client->adapter->dev; - client->dev.bus = &i2c_bus_type; - client->dev.type = &i2c_client_type; - client->dev.of_node = info->of_node; - client->dev.fwnode = info->fwnode; - - i2c_dev_set_name(adap, client); - - if (info->properties) { - status = device_add_properties(&client->dev, info->properties); - if (status) { - dev_err(&adap->dev, - "Failed to add properties to client %s: %d\n", - client->name, status); - goto out_err; - } - } - - status = device_register(&client->dev); - if (status) - goto out_free_props; - - dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", - client->name, dev_name(&client->dev)); - - return client; - -out_free_props: - if (info->properties) - device_remove_properties(&client->dev); -out_err: - dev_err(&adap->dev, - "Failed to register i2c client %s at 0x%02x (%d)\n", - client->name, client->addr, status); -out_err_silent: - kfree(client); - return NULL; -} -EXPORT_SYMBOL_GPL(i2c_new_device); - - -/** - * i2c_unregister_device - reverse effect of i2c_new_device() - * @client: value returned from i2c_new_device() - * Context: can sleep - */ -void i2c_unregister_device(struct i2c_client *client) -{ - if (client->dev.of_node) - of_node_clear_flag(client->dev.of_node, OF_POPULATED); - if (ACPI_COMPANION(&client->dev)) - acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev)); - device_unregister(&client->dev); -} -EXPORT_SYMBOL_GPL(i2c_unregister_device); - - -static const struct i2c_device_id dummy_id[] = { - { "dummy", 0 }, - { }, -}; - -static int dummy_probe(struct i2c_client *client, - const struct i2c_device_id *id) -{ - return 0; -} - -static int dummy_remove(struct i2c_client *client) -{ - return 0; -} - -static struct i2c_driver dummy_driver = { - .driver.name = "dummy", - .probe = dummy_probe, - .remove = dummy_remove, - .id_table = dummy_id, -}; - -/** - * i2c_new_dummy - return a new i2c device bound to a dummy driver - * @adapter: the adapter managing the device - * @address: seven bit address to be used - * Context: can sleep - * - * This returns an I2C client bound to the "dummy" driver, intended for use - * with devices that consume multiple addresses. Examples of such chips - * include various EEPROMS (like 24c04 and 24c08 models). - * - * These dummy devices have two main uses. First, most I2C and SMBus calls - * except i2c_transfer() need a client handle; the dummy will be that handle. - * And second, this prevents the specified address from being bound to a - * different driver. - * - * This returns the new i2c client, which should be saved for later use with - * i2c_unregister_device(); or NULL to indicate an error. - */ -struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) -{ - struct i2c_board_info info = { - I2C_BOARD_INFO("dummy", address), - }; - - return i2c_new_device(adapter, &info); -} -EXPORT_SYMBOL_GPL(i2c_new_dummy); - -/** - * i2c_new_secondary_device - Helper to get the instantiated secondary address - * and create the associated device - * @client: Handle to the primary client - * @name: Handle to specify which secondary address to get - * @default_addr: Used as a fallback if no secondary address was specified - * Context: can sleep - * - * I2C clients can be composed of multiple I2C slaves bound together in a single - * component. The I2C client driver then binds to the master I2C slave and needs - * to create I2C dummy clients to communicate with all the other slaves. - * - * This function creates and returns an I2C dummy client whose I2C address is - * retrieved from the platform firmware based on the given slave name. If no - * address is specified by the firmware default_addr is used. - * - * On DT-based platforms the address is retrieved from the "reg" property entry - * cell whose "reg-names" value matches the slave name. - * - * This returns the new i2c client, which should be saved for later use with - * i2c_unregister_device(); or NULL to indicate an error. - */ -struct i2c_client *i2c_new_secondary_device(struct i2c_client *client, - const char *name, - u16 default_addr) -{ - struct device_node *np = client->dev.of_node; - u32 addr = default_addr; - int i; - - if (np) { - i = of_property_match_string(np, "reg-names", name); - if (i >= 0) - of_property_read_u32_index(np, "reg", i, &addr); - } - - dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr); - return i2c_new_dummy(client->adapter, addr); -} -EXPORT_SYMBOL_GPL(i2c_new_secondary_device); - -/* ------------------------------------------------------------------------- */ - -/* I2C bus adapters -- one roots each I2C or SMBUS segment */ - -static void i2c_adapter_dev_release(struct device *dev) -{ - struct i2c_adapter *adap = to_i2c_adapter(dev); - complete(&adap->dev_released); -} - -unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) -{ - unsigned int depth = 0; - - while ((adapter = i2c_parent_is_i2c_adapter(adapter))) - depth++; - - WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES, - "adapter depth exceeds lockdep subclass limit\n"); - - return depth; -} -EXPORT_SYMBOL_GPL(i2c_adapter_depth); - -/* - * Let users instantiate I2C devices through sysfs. This can be used when - * platform initialization code doesn't contain the proper data for - * whatever reason. Also useful for drivers that do device detection and - * detection fails, either because the device uses an unexpected address, - * or this is a compatible device with different ID register values. - * - * Parameter checking may look overzealous, but we really don't want - * the user to provide incorrect parameters. - */ -static ssize_t -i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, - const char *buf, size_t count) -{ - struct i2c_adapter *adap = to_i2c_adapter(dev); - struct i2c_board_info info; - struct i2c_client *client; - char *blank, end; - int res; - - memset(&info, 0, sizeof(struct i2c_board_info)); - - blank = strchr(buf, ' '); - if (!blank) { - dev_err(dev, "%s: Missing parameters\n", "new_device"); - return -EINVAL; - } - if (blank - buf > I2C_NAME_SIZE - 1) { - dev_err(dev, "%s: Invalid device name\n", "new_device"); - return -EINVAL; - } - memcpy(info.type, buf, blank - buf); - - /* Parse remaining parameters, reject extra parameters */ - res = sscanf(++blank, "%hi%c", &info.addr, &end); - if (res < 1) { - dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); - return -EINVAL; - } - if (res > 1 && end != '\n') { - dev_err(dev, "%s: Extra parameters\n", "new_device"); - return -EINVAL; - } - - if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) { - info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT; - info.flags |= I2C_CLIENT_TEN; - } - - if (info.addr & I2C_ADDR_OFFSET_SLAVE) { - info.addr &= ~I2C_ADDR_OFFSET_SLAVE; - info.flags |= I2C_CLIENT_SLAVE; - } - - client = i2c_new_device(adap, &info); - if (!client) - return -EINVAL; - - /* Keep track of the added device */ - mutex_lock(&adap->userspace_clients_lock); - list_add_tail(&client->detected, &adap->userspace_clients); - mutex_unlock(&adap->userspace_clients_lock); - dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", - info.type, info.addr); - - return count; -} -static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); - -/* - * And of course let the users delete the devices they instantiated, if - * they got it wrong. This interface can only be used to delete devices - * instantiated by i2c_sysfs_new_device above. This guarantees that we - * don't delete devices to which some kernel code still has references. - * - * Parameter checking may look overzealous, but we really don't want - * the user to delete the wrong device. - */ -static ssize_t -i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, - const char *buf, size_t count) -{ - struct i2c_adapter *adap = to_i2c_adapter(dev); - struct i2c_client *client, *next; - unsigned short addr; - char end; - int res; - - /* Parse parameters, reject extra parameters */ - res = sscanf(buf, "%hi%c", &addr, &end); - if (res < 1) { - dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); - return -EINVAL; - } - if (res > 1 && end != '\n') { - dev_err(dev, "%s: Extra parameters\n", "delete_device"); - return -EINVAL; - } - - /* Make sure the device was added through sysfs */ - res = -ENOENT; - mutex_lock_nested(&adap->userspace_clients_lock, - i2c_adapter_depth(adap)); - list_for_each_entry_safe(client, next, &adap->userspace_clients, - detected) { - if (i2c_encode_flags_to_addr(client) == addr) { - dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", - "delete_device", client->name, client->addr); - - list_del(&client->detected); - i2c_unregister_device(client); - res = count; - break; - } - } - mutex_unlock(&adap->userspace_clients_lock); - - if (res < 0) - dev_err(dev, "%s: Can't find device in list\n", - "delete_device"); - return res; -} -static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, - i2c_sysfs_delete_device); - -static struct attribute *i2c_adapter_attrs[] = { - &dev_attr_name.attr, - &dev_attr_new_device.attr, - &dev_attr_delete_device.attr, - NULL -}; -ATTRIBUTE_GROUPS(i2c_adapter); - -struct device_type i2c_adapter_type = { - .groups = i2c_adapter_groups, - .release = i2c_adapter_dev_release, -}; -EXPORT_SYMBOL_GPL(i2c_adapter_type); - -/** - * i2c_verify_adapter - return parameter as i2c_adapter or NULL - * @dev: device, probably from some driver model iterator - * - * When traversing the driver model tree, perhaps using driver model - * iterators like @device_for_each_child(), you can't assume very much - * about the nodes you find. Use this function to avoid oopses caused - * by wrongly treating some non-I2C device as an i2c_adapter. - */ -struct i2c_adapter *i2c_verify_adapter(struct device *dev) -{ - return (dev->type == &i2c_adapter_type) - ? to_i2c_adapter(dev) - : NULL; -} -EXPORT_SYMBOL(i2c_verify_adapter); - -#ifdef CONFIG_I2C_COMPAT -static struct class_compat *i2c_adapter_compat_class; -#endif - -static void i2c_scan_static_board_info(struct i2c_adapter *adapter) -{ - struct i2c_devinfo *devinfo; - - down_read(&__i2c_board_lock); - list_for_each_entry(devinfo, &__i2c_board_list, list) { - if (devinfo->busnum == adapter->nr - && !i2c_new_device(adapter, - &devinfo->board_info)) - dev_err(&adapter->dev, - "Can't create device at 0x%02x\n", - devinfo->board_info.addr); - } - up_read(&__i2c_board_lock); -} - -/* 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", - addr, node->full_name); - return ERR_PTR(-EINVAL); - } - - info.addr = addr; - info.of_node = of_node_get(node); - info.archdata = &dev_ad; - - if (of_property_read_bool(node, "host-notify")) - info.flags |= I2C_CLIENT_HOST_NOTIFY; - - 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 *bus, *node; - struct i2c_client *client; - - /* 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"); - - bus = of_get_child_by_name(adap->dev.of_node, "i2c-bus"); - if (!bus) - bus = of_node_get(adap->dev.of_node); - - for_each_available_child_of_node(bus, node) { - if (of_node_test_and_set_flag(node, OF_POPULATED)) - continue; - - client = of_i2c_register_device(adap, node); - if (IS_ERR(client)) { - dev_warn(&adap->dev, - "Failed to create I2C device for %s\n", - node->full_name); - of_node_clear_flag(node, OF_POPULATED); - } - } - - of_node_put(bus); -} - -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); - -static const struct of_device_id* -i2c_of_match_device_sysfs(const struct of_device_id *matches, - struct i2c_client *client) -{ - const char *name; - - for (; matches->compatible[0]; matches++) { - /* - * Adding devices through the i2c sysfs interface provides us - * a string to match which may be compatible with the device - * tree compatible strings, however with no actual of_node the - * of_match_device() will not match - */ - if (sysfs_streq(client->name, matches->compatible)) - return matches; - - name = strchr(matches->compatible, ','); - if (!name) - name = matches->compatible; - else - name++; - - if (sysfs_streq(client->name, name)) - return matches; - } - - return NULL; -} - -const struct of_device_id -*i2c_of_match_device(const struct of_device_id *matches, - struct i2c_client *client) -{ - const struct of_device_id *match; - - if (!(client && matches)) - return NULL; - - match = of_match_device(matches, &client->dev); - if (match) - return match; - - return i2c_of_match_device_sysfs(matches, client); -} -EXPORT_SYMBOL_GPL(i2c_of_match_device); -#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 const struct i2c_lock_operations i2c_adapter_lock_ops = { - .lock_bus = i2c_adapter_lock_bus, - .trylock_bus = i2c_adapter_trylock_bus, - .unlock_bus = i2c_adapter_unlock_bus, -}; - -static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap) -{ - struct irq_domain *domain = adap->host_notify_domain; - irq_hw_number_t hwirq; - - if (!domain) - return; - - for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++) - irq_dispose_mapping(irq_find_mapping(domain, hwirq)); - - irq_domain_remove(domain); - adap->host_notify_domain = NULL; -} - -static int i2c_host_notify_irq_map(struct irq_domain *h, - unsigned int virq, - irq_hw_number_t hw_irq_num) -{ - irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq); - - return 0; -} - -static const struct irq_domain_ops i2c_host_notify_irq_ops = { - .map = i2c_host_notify_irq_map, -}; - -static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap) -{ - struct irq_domain *domain; - - if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY)) - return 0; - - domain = irq_domain_create_linear(adap->dev.fwnode, - I2C_ADDR_7BITS_COUNT, - &i2c_host_notify_irq_ops, adap); - if (!domain) - return -ENOMEM; - - adap->host_notify_domain = domain; - - return 0; -} - -/** - * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct - * I2C client. - * @adap: the adapter - * @addr: the I2C address of the notifying device - * Context: can't sleep - * - * Helper function to be called from an I2C bus driver's interrupt - * handler. It will schedule the Host Notify IRQ. - */ -int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr) -{ - int irq; - - if (!adap) - return -EINVAL; - - irq = irq_find_mapping(adap->host_notify_domain, addr); - if (irq <= 0) - return -ENXIO; - - generic_handle_irq(irq); - - return 0; -} -EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify); - -static int i2c_register_adapter(struct i2c_adapter *adap) -{ - int res = -EINVAL; - - /* Can't register until after driver model init */ - if (WARN_ON(!is_registered)) { - res = -EAGAIN; - goto out_list; - } - - /* Sanity checks */ - if (WARN(!adap->name[0], "i2c adapter has no name")) - goto out_list; - - if (!adap->algo) { - pr_err("adapter '%s': no algo supplied!\n", adap->name); - goto out_list; - } - - if (!adap->lock_ops) - adap->lock_ops = &i2c_adapter_lock_ops; - - rt_mutex_init(&adap->bus_lock); - rt_mutex_init(&adap->mux_lock); - mutex_init(&adap->userspace_clients_lock); - INIT_LIST_HEAD(&adap->userspace_clients); - - /* Set default timeout to 1 second if not already set */ - if (adap->timeout == 0) - adap->timeout = HZ; - - /* register soft irqs for Host Notify */ - res = i2c_setup_host_notify_irq_domain(adap); - if (res) { - pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n", - adap->name, res); - goto out_list; - } - - dev_set_name(&adap->dev, "i2c-%d", adap->nr); - adap->dev.bus = &i2c_bus_type; - adap->dev.type = &i2c_adapter_type; - res = device_register(&adap->dev); - if (res) { - pr_err("adapter '%s': can't register device (%d)\n", adap->name, res); - goto out_list; - } - - dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); - - pm_runtime_no_callbacks(&adap->dev); - pm_suspend_ignore_children(&adap->dev, true); - pm_runtime_enable(&adap->dev); - -#ifdef CONFIG_I2C_COMPAT - res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, - adap->dev.parent); - if (res) - dev_warn(&adap->dev, - "Failed to create compatibility class link\n"); -#endif - - i2c_init_recovery(adap); - - /* create pre-declared device nodes */ - of_i2c_register_devices(adap); - i2c_acpi_register_devices(adap); - i2c_acpi_install_space_handler(adap); - - if (adap->nr < __i2c_first_dynamic_bus_num) - i2c_scan_static_board_info(adap); - - /* Notify drivers */ - mutex_lock(&core_lock); - bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); - mutex_unlock(&core_lock); - - return 0; - -out_list: - mutex_lock(&core_lock); - idr_remove(&i2c_adapter_idr, adap->nr); - mutex_unlock(&core_lock); - return res; -} - -/** - * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 - * @adap: the adapter to register (with adap->nr initialized) - * Context: can sleep - * - * See i2c_add_numbered_adapter() for details. - */ -static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) -{ - int id; - - mutex_lock(&core_lock); - id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL); - mutex_unlock(&core_lock); - if (WARN(id < 0, "couldn't get idr")) - return id == -ENOSPC ? -EBUSY : id; - - return i2c_register_adapter(adap); -} - -/** - * i2c_add_adapter - declare i2c adapter, use dynamic bus number - * @adapter: the adapter to add - * Context: can sleep - * - * This routine is used to declare an I2C adapter when its bus number - * doesn't matter or when its bus number is specified by an dt alias. - * Examples of bases when the bus number doesn't matter: I2C adapters - * dynamically added by USB links or PCI plugin cards. - * - * When this returns zero, a new bus number was allocated and stored - * in adap->nr, and the specified adapter became available for clients. - * Otherwise, a negative errno value is returned. - */ -int i2c_add_adapter(struct i2c_adapter *adapter) -{ - struct device *dev = &adapter->dev; - int id; - - if (dev->of_node) { - id = of_alias_get_id(dev->of_node, "i2c"); - if (id >= 0) { - adapter->nr = id; - return __i2c_add_numbered_adapter(adapter); - } - } - - mutex_lock(&core_lock); - id = idr_alloc(&i2c_adapter_idr, adapter, - __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); - mutex_unlock(&core_lock); - if (WARN(id < 0, "couldn't get idr")) - return id; - - adapter->nr = id; - - return i2c_register_adapter(adapter); -} -EXPORT_SYMBOL(i2c_add_adapter); - -/** - * i2c_add_numbered_adapter - declare i2c adapter, use static bus number - * @adap: the adapter to register (with adap->nr initialized) - * Context: can sleep - * - * This routine is used to declare an I2C adapter when its bus number - * matters. For example, use it for I2C adapters from system-on-chip CPUs, - * or otherwise built in to the system's mainboard, and where i2c_board_info - * is used to properly configure I2C devices. - * - * If the requested bus number is set to -1, then this function will behave - * identically to i2c_add_adapter, and will dynamically assign a bus number. - * - * If no devices have pre-been declared for this bus, then be sure to - * register the adapter before any dynamically allocated ones. Otherwise - * the required bus ID may not be available. - * - * When this returns zero, the specified adapter became available for - * clients using the bus number provided in adap->nr. Also, the table - * of I2C devices pre-declared using i2c_register_board_info() is scanned, - * and the appropriate driver model device nodes are created. Otherwise, a - * negative errno value is returned. - */ -int i2c_add_numbered_adapter(struct i2c_adapter *adap) -{ - if (adap->nr == -1) /* -1 means dynamically assign bus id */ - return i2c_add_adapter(adap); - - return __i2c_add_numbered_adapter(adap); -} -EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); - -static void i2c_do_del_adapter(struct i2c_driver *driver, - struct i2c_adapter *adapter) -{ - struct i2c_client *client, *_n; - - /* Remove the devices we created ourselves as the result of hardware - * probing (using a driver's detect method) */ - list_for_each_entry_safe(client, _n, &driver->clients, detected) { - if (client->adapter == adapter) { - dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", - client->name, client->addr); - list_del(&client->detected); - i2c_unregister_device(client); - } - } -} - -static int __unregister_client(struct device *dev, void *dummy) -{ - struct i2c_client *client = i2c_verify_client(dev); - if (client && strcmp(client->name, "dummy")) - i2c_unregister_device(client); - return 0; -} - -static int __unregister_dummy(struct device *dev, void *dummy) -{ - struct i2c_client *client = i2c_verify_client(dev); - 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("attempting to delete unregistered adapter [%s]\n", adap->name); - return; - } - - i2c_acpi_remove_space_handler(adap); - /* Tell drivers about this removal */ - mutex_lock(&core_lock); - bus_for_each_drv(&i2c_bus_type, NULL, adap, - __process_removed_adapter); - mutex_unlock(&core_lock); - - /* Remove devices instantiated from sysfs */ - mutex_lock_nested(&adap->userspace_clients_lock, - i2c_adapter_depth(adap)); - list_for_each_entry_safe(client, next, &adap->userspace_clients, - detected) { - dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, - client->addr); - list_del(&client->detected); - i2c_unregister_device(client); - } - mutex_unlock(&adap->userspace_clients_lock); - - /* Detach any active clients. This can't fail, thus we do not - * check the returned value. This is a two-pass process, because - * we can't remove the dummy devices during the first pass: they - * could have been instantiated by real devices wishing to clean - * them up properly, so we give them a chance to do that first. */ - device_for_each_child(&adap->dev, NULL, __unregister_client); - device_for_each_child(&adap->dev, NULL, __unregister_dummy); - -#ifdef CONFIG_I2C_COMPAT - class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, - adap->dev.parent); -#endif - - /* device name is gone after device_unregister */ - dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); - - pm_runtime_disable(&adap->dev); - - i2c_host_notify_irq_teardown(adap); - - /* wait until all references to the device are gone - * - * FIXME: This is old code and should ideally be replaced by an - * alternative which results in decoupling the lifetime of the struct - * device from the i2c_adapter, like spi or netdev do. Any solution - * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled! - */ - init_completion(&adap->dev_released); - device_unregister(&adap->dev); - wait_for_completion(&adap->dev_released); - - /* free bus id */ - mutex_lock(&core_lock); - idr_remove(&i2c_adapter_idr, adap->nr); - mutex_unlock(&core_lock); - - /* Clear the device structure in case this adapter is ever going to be - added again */ - memset(&adap->dev, 0, sizeof(adap->dev)); -} -EXPORT_SYMBOL(i2c_del_adapter); - -/** - * i2c_parse_fw_timings - get I2C related timing parameters from firmware - * @dev: The device to scan for I2C timing properties - * @t: the i2c_timings struct to be filled with values - * @use_defaults: bool to use sane defaults derived from the I2C specification - * when properties are not found, otherwise use 0 - * - * Scan the device for the generic I2C properties describing timing parameters - * for the signal and fill the given struct with the results. If a property was - * not found and use_defaults was true, then maximum timings are assumed which - * are derived from the I2C specification. If use_defaults is not used, the - * results will be 0, so drivers can apply their own defaults later. The latter - * is mainly intended for avoiding regressions of existing drivers which want - * to switch to this function. New drivers almost always should use the defaults. - */ - -void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults) -{ - int ret; - - memset(t, 0, sizeof(*t)); - - ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz); - if (ret && use_defaults) - t->bus_freq_hz = 100000; - - ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns); - if (ret && use_defaults) { - if (t->bus_freq_hz <= 100000) - t->scl_rise_ns = 1000; - else if (t->bus_freq_hz <= 400000) - t->scl_rise_ns = 300; - else - t->scl_rise_ns = 120; - } - - ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns); - if (ret && use_defaults) { - if (t->bus_freq_hz <= 400000) - t->scl_fall_ns = 300; - else - t->scl_fall_ns = 120; - } - - device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns); - - ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns); - if (ret && use_defaults) - t->sda_fall_ns = t->scl_fall_ns; -} -EXPORT_SYMBOL_GPL(i2c_parse_fw_timings); - -/* ------------------------------------------------------------------------- */ - -int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) -{ - int res; - - mutex_lock(&core_lock); - res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); - mutex_unlock(&core_lock); - - return res; -} -EXPORT_SYMBOL_GPL(i2c_for_each_dev); - -static int __process_new_driver(struct device *dev, void *data) -{ - if (dev->type != &i2c_adapter_type) - return 0; - return i2c_do_add_adapter(data, to_i2c_adapter(dev)); -} - -/* - * An i2c_driver is used with one or more i2c_client (device) nodes to access - * i2c slave chips, on a bus instance associated with some i2c_adapter. - */ - -int i2c_register_driver(struct module *owner, struct i2c_driver *driver) -{ - int res; - - /* Can't register until after driver model init */ - if (WARN_ON(!is_registered)) - return -EAGAIN; - - /* add the driver to the list of i2c drivers in the driver core */ - driver->driver.owner = owner; - driver->driver.bus = &i2c_bus_type; - INIT_LIST_HEAD(&driver->clients); - - /* When registration returns, the driver core - * will have called probe() for all matching-but-unbound devices. - */ - res = driver_register(&driver->driver); - if (res) - return res; - - pr_debug("driver [%s] registered\n", driver->driver.name); - - /* Walk the adapters that are already present */ - i2c_for_each_dev(driver, __process_new_driver); - - return 0; -} -EXPORT_SYMBOL(i2c_register_driver); - -static int __process_removed_driver(struct device *dev, void *data) -{ - if (dev->type == &i2c_adapter_type) - i2c_do_del_adapter(data, to_i2c_adapter(dev)); - return 0; -} - -/** - * i2c_del_driver - unregister I2C driver - * @driver: the driver being unregistered - * Context: can sleep - */ -void i2c_del_driver(struct i2c_driver *driver) -{ - i2c_for_each_dev(driver, __process_removed_driver); - - driver_unregister(&driver->driver); - pr_debug("driver [%s] unregistered\n", driver->driver.name); -} -EXPORT_SYMBOL(i2c_del_driver); - -/* ------------------------------------------------------------------------- */ - -/** - * i2c_use_client - increments the reference count of the i2c client structure - * @client: the client being referenced - * - * Each live reference to a client should be refcounted. The driver model does - * that automatically as part of driver binding, so that most drivers don't - * need to do this explicitly: they hold a reference until they're unbound - * from the device. - * - * A pointer to the client with the incremented reference counter is returned. - */ -struct i2c_client *i2c_use_client(struct i2c_client *client) -{ - if (client && get_device(&client->dev)) - return client; - return NULL; -} -EXPORT_SYMBOL(i2c_use_client); - -/** - * i2c_release_client - release a use of the i2c client structure - * @client: the client being no longer referenced - * - * Must be called when a user of a client is finished with it. - */ -void i2c_release_client(struct i2c_client *client) -{ - if (client) - put_device(&client->dev); -} -EXPORT_SYMBOL(i2c_release_client); - -struct i2c_cmd_arg { - unsigned cmd; - void *arg; -}; - -static int i2c_cmd(struct device *dev, void *_arg) -{ - struct i2c_client *client = i2c_verify_client(dev); - struct i2c_cmd_arg *arg = _arg; - struct i2c_driver *driver; - - if (!client || !client->dev.driver) - return 0; - - driver = to_i2c_driver(client->dev.driver); - if (driver->command) - driver->command(client, arg->cmd, arg->arg); - return 0; -} - -void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) -{ - struct i2c_cmd_arg cmd_arg; - - cmd_arg.cmd = cmd; - cmd_arg.arg = arg; - device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); -} -EXPORT_SYMBOL(i2c_clients_command); - -#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)) { - dev_err(&adap->dev, "failed to create client for '%s'\n", - rd->dn->full_name); - of_node_clear_flag(rd->dn, OF_POPULATED); - 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; - - is_registered = true; - -#ifdef CONFIG_I2C_COMPAT - i2c_adapter_compat_class = class_compat_register("i2c-adapter"); - if (!i2c_adapter_compat_class) { - retval = -ENOMEM; - goto bus_err; - } -#endif - retval = i2c_add_driver(&dummy_driver); - if (retval) - goto class_err; - - if (IS_ENABLED(CONFIG_OF_DYNAMIC)) - WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier)); - if (IS_ENABLED(CONFIG_ACPI)) - WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier)); - - return 0; - -class_err: -#ifdef CONFIG_I2C_COMPAT - class_compat_unregister(i2c_adapter_compat_class); -bus_err: -#endif - is_registered = false; - bus_unregister(&i2c_bus_type); - return retval; -} - -static void __exit i2c_exit(void) -{ - if (IS_ENABLED(CONFIG_ACPI)) - WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier)); - if (IS_ENABLED(CONFIG_OF_DYNAMIC)) - WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier)); - i2c_del_driver(&dummy_driver); -#ifdef CONFIG_I2C_COMPAT - class_compat_unregister(i2c_adapter_compat_class); -#endif - bus_unregister(&i2c_bus_type); - tracepoint_synchronize_unregister(); -} - -/* We must initialize early, because some subsystems register i2c drivers - * in subsys_initcall() code, but are linked (and initialized) before i2c. - */ -postcore_initcall(i2c_init); -module_exit(i2c_exit); - -/* ---------------------------------------------------- - * the functional interface to the i2c busses. - * ---------------------------------------------------- - */ - -/* Check if val is exceeding the quirk IFF quirk is non 0 */ -#define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk))) - -static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg) -{ - dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n", - err_msg, msg->addr, msg->len, - msg->flags & I2C_M_RD ? "read" : "write"); - return -EOPNOTSUPP; -} - -static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) -{ - const struct i2c_adapter_quirks *q = adap->quirks; - int max_num = q->max_num_msgs, i; - bool do_len_check = true; - - if (q->flags & I2C_AQ_COMB) { - max_num = 2; - - /* special checks for combined messages */ - if (num == 2) { - if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD) - return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write"); - - if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD)) - return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read"); - - if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr) - return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr"); - - if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len)) - return i2c_quirk_error(adap, &msgs[0], "msg too long"); - - if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len)) - return i2c_quirk_error(adap, &msgs[1], "msg too long"); - - do_len_check = false; - } - } - - if (i2c_quirk_exceeded(num, max_num)) - return i2c_quirk_error(adap, &msgs[0], "too many messages"); - - for (i = 0; i < num; i++) { - u16 len = msgs[i].len; - - if (msgs[i].flags & I2C_M_RD) { - if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len)) - return i2c_quirk_error(adap, &msgs[i], "msg too long"); - } else { - if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len)) - return i2c_quirk_error(adap, &msgs[i], "msg too long"); - } - } - - return 0; -} - -/** - * __i2c_transfer - unlocked flavor of i2c_transfer - * @adap: Handle to I2C bus - * @msgs: One or more messages to execute before STOP is issued to - * terminate the operation; each message begins with a START. - * @num: Number of messages to be executed. - * - * Returns negative errno, else the number of messages executed. - * - * Adapter lock must be held when calling this function. No debug logging - * takes place. adap->algo->master_xfer existence isn't checked. - */ -int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) -{ - unsigned long orig_jiffies; - int ret, try; - - if (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_bus(adap, I2C_LOCK_SEGMENT); - if (!ret) - /* I2C activity is ongoing. */ - return -EAGAIN; - } else { - i2c_lock_bus(adap, I2C_LOCK_SEGMENT); - } - - ret = __i2c_transfer(adap, msgs, num); - i2c_unlock_bus(adap, I2C_LOCK_SEGMENT); - - return ret; - } else { - dev_dbg(&adap->dev, "I2C level transfers not supported\n"); - return -EOPNOTSUPP; - } -} -EXPORT_SYMBOL(i2c_transfer); - -/** - * i2c_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 = i2c_8bit_addr_from_msg(msg); - 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("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_bus(adapter, I2C_LOCK_SEGMENT); - - /* 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_bus(adapter, I2C_LOCK_SEGMENT); - - 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, "insufficient 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; - } - } - - if (!client->adapter->algo->reg_slave) { - dev_err(&client->dev, "%s: not supported by adapter\n", __func__); - return -EOPNOTSUPP; - } - - client->slave_cb = slave_cb; - - i2c_lock_adapter(client->adapter); - ret = client->adapter->algo->reg_slave(client); - i2c_unlock_adapter(client->adapter); - - if (ret) { - client->slave_cb = NULL; - dev_err(&client->dev, "%s: adapter returned error %d\n", __func__, ret); - } - - return ret; -} -EXPORT_SYMBOL_GPL(i2c_slave_register); - -int i2c_slave_unregister(struct i2c_client *client) -{ - int ret; - - if (!client->adapter->algo->unreg_slave) { - dev_err(&client->dev, "%s: not supported by adapter\n", __func__); - return -EOPNOTSUPP; - } - - i2c_lock_adapter(client->adapter); - ret = client->adapter->algo->unreg_slave(client); - i2c_unlock_adapter(client->adapter); - - if (ret == 0) - client->slave_cb = NULL; - else - dev_err(&client->dev, "%s: adapter returned error %d\n", __func__, ret); - - return ret; -} -EXPORT_SYMBOL_GPL(i2c_slave_unregister); - -/** - * i2c_detect_slave_mode - detect operation mode - * @dev: The device owning the bus - * - * This checks the device nodes for an I2C slave by checking the address - * used in the reg property. If the address match the I2C_OWN_SLAVE_ADDRESS - * flag this means the device is configured to act as a I2C slave and it will - * be listening at that address. - * - * Returns true if an I2C own slave address is detected, otherwise returns - * false. - */ -bool i2c_detect_slave_mode(struct device *dev) -{ - if (IS_BUILTIN(CONFIG_OF) && dev->of_node) { - struct device_node *child; - u32 reg; - - for_each_child_of_node(dev->of_node, child) { - of_property_read_u32(child, "reg", ®); - if (reg & I2C_OWN_SLAVE_ADDRESS) { - of_node_put(child); - return true; - } - } - } else if (IS_BUILTIN(CONFIG_ACPI) && ACPI_HANDLE(dev)) { - dev_dbg(dev, "ACPI slave is not supported yet\n"); - } - return false; -} -EXPORT_SYMBOL_GPL(i2c_detect_slave_mode); - -#endif - -MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); -MODULE_DESCRIPTION("I2C-Bus main module"); -MODULE_LICENSE("GPL"); |