diff options
Diffstat (limited to 'drivers/i2c/i2c-core-base.c')
| -rw-r--r-- | drivers/i2c/i2c-core-base.c | 3831 |
1 files changed, 3831 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c new file mode 100644 index 000000000000..82576aaccc90 --- /dev/null +++ b/drivers/i2c/i2c-core-base.c @@ -0,0 +1,3831 @@ +/* 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 stri |