| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* |
| * ChromeOS Wilco Embedded Controller |
| * |
| * Copyright 2018 Google LLC |
| */ |
| |
| #ifndef WILCO_EC_H |
| #define WILCO_EC_H |
| |
| #include <linux/device.h> |
| #include <linux/kernel.h> |
| |
| /* Message flags for using the mailbox() interface */ |
| #define WILCO_EC_FLAG_NO_RESPONSE BIT(0) /* EC does not respond */ |
| #define WILCO_EC_FLAG_EXTENDED_DATA BIT(1) /* EC returns 256 data bytes */ |
| #define WILCO_EC_FLAG_RAW_REQUEST BIT(2) /* Do not trim request data */ |
| #define WILCO_EC_FLAG_RAW_RESPONSE BIT(3) /* Do not trim response data */ |
| #define WILCO_EC_FLAG_RAW (WILCO_EC_FLAG_RAW_REQUEST | \ |
| WILCO_EC_FLAG_RAW_RESPONSE) |
| |
| /* Normal commands have a maximum 32 bytes of data */ |
| #define EC_MAILBOX_DATA_SIZE 32 |
| /* Extended commands have 256 bytes of response data */ |
| #define EC_MAILBOX_DATA_SIZE_EXTENDED 256 |
| |
| /** |
| * 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. |
| */ |
| 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 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 request, data + last 2 bytes of the header. |
| * @command: Mailbox command code, unique for each mailbox_id set. |
| * @reserved_raw: Set to zero for most commands, but is used by |
| * some command types and for raw commands. |
| */ |
| struct wilco_ec_request { |
| u8 struct_version; |
| u8 checksum; |
| u16 mailbox_id; |
| u8 mailbox_version; |
| u8 reserved; |
| u16 data_size; |
| u8 command; |
| u8 reserved_raw; |
| } __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. |
| * @mbox0: EC returned data at offset 0 is unused (always 0) so this byte |
| * is treated as part of the header instead of the data. |
| * @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 mbox0; |
| u8 data[0]; |
| } __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_SHORT: 32 bytes of telemetry data provided by the EC. |
| * @WILCO_EC_MSG_TELEMETRY_LONG: 256 bytes of telemetry data provided by the EC. |
| */ |
| enum wilco_ec_msg_type { |
| WILCO_EC_MSG_LEGACY = 0x00f0, |
| WILCO_EC_MSG_PROPERTY = 0x00f2, |
| WILCO_EC_MSG_TELEMETRY_SHORT = 0x00f5, |
| WILCO_EC_MSG_TELEMETRY_LONG = 0x00f6, |
| }; |
| |
| /** |
| * struct wilco_ec_message - Request and response message. |
| * @type: Mailbox message type. |
| * @flags: Message flags, e.g. %WILCO_EC_FLAG_NO_RESPONSE. |
| * @command: Mailbox command code. |
| * @result: Result code from the EC. Non-zero indicates an error. |
| * @request_size: Number of bytes to send to the EC. |
| * @request_data: Buffer containing the request data. |
| * @response_size: Number of bytes expected from the EC. |
| * This is 32 by default and 256 if the flag |
| * is set for %WILCO_EC_FLAG_EXTENDED_DATA |
| * @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; |
| u8 command; |
| u8 result; |
| 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); |
| |
| #endif /* WILCO_EC_H */ |