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Diffstat (limited to 'include/linux/platform_data/wilco-ec.h')
| -rw-r--r-- | include/linux/platform_data/wilco-ec.h | 144 |
1 files changed, 144 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 000000000000..446473a46b88 --- /dev/null +++ b/include/linux/platform_data/wilco-ec.h @@ -0,0 +1,144 @@ +/* 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 */ |