diff options
Diffstat (limited to 'drivers/i2c/i2c-core.c')
| -rw-r--r-- | drivers/i2c/i2c-core.c | 364 |
1 files changed, 364 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 632057a4461..ccfbbab82a1 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -27,6 +27,8 @@ 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> */ #include <linux/module.h> @@ -78,6 +80,368 @@ void i2c_transfer_trace_unreg(void) static_key_slow_dec(&i2c_trace_msg); } +#if defined(CONFIG_ACPI) +struct acpi_i2c_handler_data { + struct acpi_connection_info info; + struct i2c_adapter *adapter; +}; + +struct gsb_buffer { + u8 status; + u8 len; + union { + u16 wdata; + u8 bdata; + u8 data[0]; + }; +} __packed; + +static int acpi_i2c_add_resource(struct acpi_resource *ares, void *data) +{ + struct i2c_board_info *info = data; + + if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { + struct acpi_resource_i2c_serialbus *sb; + + sb = &ares->data.i2c_serial_bus; + if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_I2C) { + info->addr = sb->slave_address; + if (sb->access_mode == ACPI_I2C_10BIT_MODE) + info->flags |= I2C_CLIENT_TEN; + } + } else if (info->irq < 0) { + struct resource r; + + if (acpi_dev_resource_interrupt(ares, 0, &r)) + info->irq = r.start; + } + + /* Tell the ACPI core to skip this resource */ + return 1; +} + +static acpi_status acpi_i2c_add_device(acpi_handle handle, u32 level, + void *data, void **return_value) +{ + struct i2c_adapter *adapter = data; + struct list_head resource_list; + struct i2c_board_info info; + struct acpi_device *adev; + int ret; + + if (acpi_bus_get_device(handle, &adev)) + return AE_OK; + if (acpi_bus_get_status(adev) || !adev->status.present) + return AE_OK; + + memset(&info, 0, sizeof(info)); + info.acpi_node.companion = adev; + info.irq = -1; + + INIT_LIST_HEAD(&resource_list); + ret = acpi_dev_get_resources(adev, &resource_list, + acpi_i2c_add_resource, &info); + acpi_dev_free_resource_list(&resource_list); + + if (ret < 0 || !info.addr) + return AE_OK; + + adev->power.flags.ignore_parent = true; + strlcpy(info.type, dev_name(&adev->dev), sizeof(info.type)); + if (!i2c_new_device(adapter, &info)) { + adev->power.flags.ignore_parent = false; + dev_err(&adapter->dev, + "failed to add I2C device %s from ACPI\n", + dev_name(&adev->dev)); + } + + return AE_OK; +} + +/** + * acpi_i2c_register_devices - enumerate I2C slave devices behind adapter + * @adap: pointer to adapter + * + * Enumerate all I2C slave devices behind this adapter by walking the ACPI + * namespace. When a device is found it will be added to the Linux device + * model and bound to the corresponding ACPI handle. + */ +static void acpi_i2c_register_devices(struct i2c_adapter *adap) +{ + acpi_handle handle; + acpi_status status; + + if (!adap->dev.parent) + return; + + handle = ACPI_HANDLE(adap->dev.parent); + if (!handle) + return; + + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, + acpi_i2c_add_device, NULL, + adap, NULL); + if (ACPI_FAILURE(status)) + dev_warn(&adap->dev, "failed to enumerate I2C slaves\n"); +} + +#else /* CONFIG_ACPI */ +static inline void acpi_i2c_register_devices(struct i2c_adapter *adap) { } +#endif /* CONFIG_ACPI */ + +#ifdef CONFIG_ACPI_I2C_OPREGION +static int acpi_gsb_i2c_read_bytes(struct i2c_client *client, + u8 cmd, u8 *data, u8 data_len) +{ + + struct i2c_msg msgs[2]; + int ret; + u8 *buffer; + + buffer = kzalloc(data_len, GFP_KERNEL); + if (!buffer) + return AE_NO_MEMORY; + + msgs[0].addr = client->addr; + msgs[0].flags = client->flags; + msgs[0].len = 1; + msgs[0].buf = &cmd; + + msgs[1].addr = client->addr; + msgs[1].flags = client->flags | I2C_M_RD; + msgs[1].len = data_len; + msgs[1].buf = buffer; + + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); + if (ret < 0) + dev_err(&client->adapter->dev, "i2c read failed\n"); + else + memcpy(data, buffer, data_len); + + kfree(buffer); + return ret; +} + +static int acpi_gsb_i2c_write_bytes(struct i2c_client *client, + u8 cmd, u8 *data, u8 data_len) +{ + + struct i2c_msg msgs[1]; + u8 *buffer; + int ret = AE_OK; + + buffer = kzalloc(data_len + 1, GFP_KERNEL); + if (!buffer) + return AE_NO_MEMORY; + + buffer[0] = cmd; + memcpy(buffer + 1, data, data_len); + + msgs[0].addr = client->addr; + msgs[0].flags = client->flags; + msgs[0].len = data_len + 1; + msgs[0].buf = buffer; + + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); + if (ret < 0) + dev_err(&client->adapter->dev, "i2c write failed\n"); + + kfree(buffer); + return ret; +} + +static acpi_status +acpi_i2c_space_handler(u32 function, acpi_physical_address command, + u32 bits, u64 *value64, + void *handler_context, void *region_context) +{ + struct gsb_buffer *gsb = (struct gsb_buffer *)value64; + struct acpi_i2c_handler_data *data = handler_context; + struct acpi_connection_info *info = &data->info; + struct acpi_resource_i2c_serialbus *sb; + struct i2c_adapter *adapter = data->adapter; + struct i2c_client client; + struct acpi_resource *ares; + u32 accessor_type = function >> 16; + u8 action = function & ACPI_IO_MASK; + acpi_status ret = AE_OK; + int status; + + ret = acpi_buffer_to_resource(info->connection, info->length, &ares); + if (ACPI_FAILURE(ret)) + return ret; + + 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; + } + + memset(&client, 0, sizeof(client)); + client.adapter = adapter; + client.addr = sb->slave_address; + client.flags = 0; + + if (sb->access_mode == ACPI_I2C_10BIT_MODE) + client.flags |= I2C_CLIENT_TEN; + + switch (accessor_type) { + case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV: + if (action == ACPI_READ) { + status = i2c_smbus_read_byte(&client); + if (status >= 0) { + gsb->bdata = status; + status = 0; + } + } else { + status = i2c_smbus_write_byte(&client, gsb->bdata); + } + break; + + case ACPI_GSB_ACCESS_ATTRIB_BYTE: + if (action == ACPI_READ) { + status = i2c_smbus_read_byte_data(&client, command); + if (status >= 0) { + gsb->bdata = status; + status = 0; + } + } else { + status = i2c_smbus_write_byte_data(&client, command, + gsb->bdata); + } + break; + + case ACPI_GSB_ACCESS_ATTRIB_WORD: + if (action == ACPI_READ) { + status = i2c_smbus_read_word_data(&client, command); + if (status >= 0) { + gsb->wdata = status; + status = 0; + } + } else { + status = i2c_smbus_write_word_data(&client, command, + gsb->wdata); + } + break; + + case ACPI_GSB_ACCESS_ATTRIB_BLOCK: + if (action == ACPI_READ) { + status = i2c_smbus_read_block_data(&client, command, + gsb->data); + if (status >= 0) { + gsb->len = status; + status = 0; + } + } else { + status = i2c_smbus_write_block_data(&client, command, + gsb->len, gsb->data); + } + break; + + case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE: + if (action == ACPI_READ) { + status = acpi_gsb_i2c_read_bytes(&client, command, + gsb->data, info->access_length); + if (status > 0) + status = 0; + } else { + status = acpi_gsb_i2c_write_bytes(&client, command, + gsb->data, info->access_length); + } + break; + + default: + pr_info("protocol(0x%02x) is not supported.\n", accessor_type); + ret = AE_BAD_PARAMETER; + goto err; + } + + gsb->status = status; + + err: + ACPI_FREE(ares); + return ret; +} + + +static int acpi_i2c_install_space_handler(struct i2c_adapter *adapter) +{ + acpi_handle handle; + struct acpi_i2c_handler_data *data; + acpi_status status; + + if (!adapter->dev.parent) + return -ENODEV; + + handle = ACPI_HANDLE(adapter->dev.parent); + + if (!handle) + return -ENODEV; + + data = kzalloc(sizeof(struct acpi_i2c_handler_data), + GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->adapter = adapter; + status = acpi_bus_attach_private_data(handle, (void *)data); + if (ACPI_FAILURE(status)) { + kfree(data); + return -ENOMEM; + } + + status = acpi_install_address_space_handler(handle, + ACPI_ADR_SPACE_GSBUS, + &acpi_i2c_space_handler, + NULL, + data); + if (ACPI_FAILURE(status)) { + dev_err(&adapter->dev, "Error installing i2c space handler\n"); + acpi_bus_detach_private_data(handle); + kfree(data); + return -ENOMEM; + } + + return 0; +} + +static void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter) +{ + acpi_handle handle; + struct acpi_i2c_handler_data *data; + acpi_status status; + + if (!adapter->dev.parent) + return; + + handle = ACPI_HANDLE(adapter->dev.parent); + + if (!handle) + return; + + acpi_remove_address_space_handler(handle, + ACPI_ADR_SPACE_GSBUS, + &acpi_i2c_space_handler); + + status = acpi_bus_get_private_data(handle, (void **)&data); + if (ACPI_SUCCESS(status)) + kfree(data); + + acpi_bus_detach_private_data(handle); +} +#else /* CONFIG_ACPI_I2C_OPREGION */ +static inline void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter) +{ } + +static inline int acpi_i2c_install_space_handler(struct i2c_adapter *adapter) +{ return 0; } +#endif /* CONFIG_ACPI_I2C_OPREGION */ + /* ------------------------------------------------------------------------- */ static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |