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Diffstat (limited to 'include/linux/platform_data/wilco-ec.h')
| -rw-r--r-- | include/linux/platform_data/wilco-ec.h | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/include/linux/platform_data/wilco-ec.h b/include/linux/platform_data/wilco-ec.h new file mode 100644 index 000000000..3e268e636 --- /dev/null +++ b/include/linux/platform_data/wilco-ec.h @@ -0,0 +1,225 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * ChromeOS Wilco Embedded Controller + * + * Copyright 2018 Google LLC + */ + +#ifndef WILCO_EC_H +#define WILCO_EC_H + +#include <linux/mutex.h> +#include <linux/types.h> + +/* Message flags for using the mailbox() interface */ +#define WILCO_EC_FLAG_NO_RESPONSE BIT(0) /* EC does not respond */ + +/* Normal commands have a maximum 32 bytes of data */ +#define EC_MAILBOX_DATA_SIZE 32 + +struct device; +struct resource; +struct platform_device; + +/** + * struct wilco_ec_device - Wilco Embedded Controller handle. + * @dev: Device handle. + * @mailbox_lock: Mutex to ensure one mailbox command at a time. + * @io_command: I/O port for mailbox command. Provided by ACPI. + * @io_data: I/O port for mailbox data. Provided by ACPI. + * @io_packet: I/O port for mailbox packet data. Provided by ACPI. + * @data_buffer: Buffer used for EC communication. The same buffer + * is used to hold the request and the response. + * @data_size: Size of the data buffer used for EC communication. + * @debugfs_pdev: The child platform_device used by the debugfs sub-driver. + * @rtc_pdev: The child platform_device used by the RTC sub-driver. + * @charger_pdev: Child platform_device used by the charger config sub-driver. + * @telem_pdev: The child platform_device used by the telemetry sub-driver. + */ +struct wilco_ec_device { + struct device *dev; + struct mutex mailbox_lock; + struct resource *io_command; + struct resource *io_data; + struct resource *io_packet; + void *data_buffer; + size_t data_size; + struct platform_device *debugfs_pdev; + struct platform_device *rtc_pdev; + struct platform_device *charger_pdev; + struct platform_device *telem_pdev; +}; + +/** + * struct wilco_ec_request - Mailbox request message format. + * @struct_version: Should be %EC_MAILBOX_PROTO_VERSION + * @checksum: Sum of all bytes must be 0. + * @mailbox_id: Mailbox identifier, specifies the command set. + * @mailbox_version: Mailbox interface version %EC_MAILBOX_VERSION + * @reserved: Set to zero. + * @data_size: Length of following data. + */ +struct wilco_ec_request { + u8 struct_version; + u8 checksum; + u16 mailbox_id; + u8 mailbox_version; + u8 reserved; + u16 data_size; +} __packed; + +/** + * struct wilco_ec_response - Mailbox response message format. + * @struct_version: Should be %EC_MAILBOX_PROTO_VERSION + * @checksum: Sum of all bytes must be 0. + * @result: Result code from the EC. Non-zero indicates an error. + * @data_size: Length of the response data buffer. + * @reserved: Set to zero. + * @data: Response data buffer. Max size is %EC_MAILBOX_DATA_SIZE_EXTENDED. + */ +struct wilco_ec_response { + u8 struct_version; + u8 checksum; + u16 result; + u16 data_size; + u8 reserved[2]; + u8 data[]; +} __packed; + +/** + * enum wilco_ec_msg_type - Message type to select a set of command codes. + * @WILCO_EC_MSG_LEGACY: Legacy EC messages for standard EC behavior. + * @WILCO_EC_MSG_PROPERTY: Get/Set/Sync EC controlled NVRAM property. + * @WILCO_EC_MSG_TELEMETRY: Request telemetry data from the EC. + */ +enum wilco_ec_msg_type { + WILCO_EC_MSG_LEGACY = 0x00f0, + WILCO_EC_MSG_PROPERTY = 0x00f2, + WILCO_EC_MSG_TELEMETRY = 0x00f5, +}; + +/** + * struct wilco_ec_message - Request and response message. + * @type: Mailbox message type. + * @flags: Message flags, e.g. %WILCO_EC_FLAG_NO_RESPONSE. + * @request_size: Number of bytes to send to the EC. + * @request_data: Buffer containing the request data. + * @response_size: Number of bytes to read from EC. + * @response_data: Buffer containing the response data, should be + * response_size bytes and allocated by caller. + */ +struct wilco_ec_message { + enum wilco_ec_msg_type type; + u8 flags; + size_t request_size; + void *request_data; + size_t response_size; + void *response_data; +}; + +/** + * wilco_ec_mailbox() - Send request to the EC and receive the response. + * @ec: Wilco EC device. + * @msg: Wilco EC message. + * + * Return: Number of bytes received or negative error code on failure. + */ +int wilco_ec_mailbox(struct wilco_ec_device *ec, struct wilco_ec_message *msg); + +/** + * wilco_keyboard_leds_init() - Set up the keyboard backlight LEDs. + * @ec: EC device to query. + * + * After this call, the keyboard backlight will be exposed through a an LED + * device at /sys/class/leds. + * + * This may sleep because it uses wilco_ec_mailbox(). + * + * Return: 0 on success, negative error code on failure. + */ +int wilco_keyboard_leds_init(struct wilco_ec_device *ec); + +/* + * A Property is typically a data item that is stored to NVRAM + * by the EC. Each of these data items has an index associated + * with it, known as the Property ID (PID). Properties may have + * variable lengths, up to a max of WILCO_EC_PROPERTY_MAX_SIZE + * bytes. Properties can be simple integers, or they may be more + * complex binary data. + */ + +#define WILCO_EC_PROPERTY_MAX_SIZE 4 + +/** + * struct ec_property_set_msg - Message to get or set a property. + * @property_id: Which property to get or set. + * @length: Number of bytes of |data| that are used. + * @data: Actual property data. + */ +struct wilco_ec_property_msg { + u32 property_id; + int length; + u8 data[WILCO_EC_PROPERTY_MAX_SIZE]; +}; + +/** + * wilco_ec_get_property() - Retrieve a property from the EC. + * @ec: Embedded Controller device. + * @prop_msg: Message for request and response. + * + * The property_id field of |prop_msg| should be filled before calling this + * function. The result will be stored in the data and length fields. + * + * Return: 0 on success, negative error code on failure. + */ +int wilco_ec_get_property(struct wilco_ec_device *ec, + struct wilco_ec_property_msg *prop_msg); + +/** + * wilco_ec_set_property() - Store a property on the EC. + * @ec: Embedded Controller device. + * @prop_msg: Message for request and response. + * + * The property_id, length, and data fields of |prop_msg| should be + * filled before calling this function. + * + * Return: 0 on success, negative error code on failure. + */ +int wilco_ec_set_property(struct wilco_ec_device *ec, + struct wilco_ec_property_msg *prop_msg); + +/** + * wilco_ec_get_byte_property() - Retrieve a byte-size property from the EC. + * @ec: Embedded Controller device. + * @property_id: Which property to retrieve. + * @val: The result value, will be filled by this function. + * + * Return: 0 on success, negative error code on failure. + */ +int wilco_ec_get_byte_property(struct wilco_ec_device *ec, u32 property_id, + u8 *val); + +/** + * wilco_ec_get_byte_property() - Store a byte-size property on the EC. + * @ec: Embedded Controller device. + * @property_id: Which property to store. + * @val: Value to store. + * + * Return: 0 on success, negative error code on failure. + */ +int wilco_ec_set_byte_property(struct wilco_ec_device *ec, u32 property_id, + u8 val); + +/** + * wilco_ec_add_sysfs() - Create sysfs entries + * @ec: Wilco EC device + * + * wilco_ec_remove_sysfs() needs to be called afterwards + * to perform the necessary cleanup. + * + * Return: 0 on success or negative error code on failure. + */ +int wilco_ec_add_sysfs(struct wilco_ec_device *ec); +void wilco_ec_remove_sysfs(struct wilco_ec_device *ec); + +#endif /* WILCO_EC_H */ |