linux/platform_data/wilco-ec.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 /*
0003  * ChromeOS Wilco Embedded Controller
0004  *
0005  * Copyright 2018 Google LLC
0006  */
0007
0008 #ifndef WILCO_EC_H
0009 #define WILCO_EC_H
0010
0011 #include <linux/mutex.h>
0012 #include <linux/types.h>
0013
0014 /* Message flags for using the mailbox() interface */
0015 #define WILCO_EC_FLAG_NO_RESPONSE   BIT(0) /* EC does not respond */
0016
0017 /* Normal commands have a maximum 32 bytes of data */
0018 #define EC_MAILBOX_DATA_SIZE        32
0019
0020 struct device;
0021 struct resource;
0022 struct platform_device;
0023
0024 /**
0025  * struct wilco_ec_device - Wilco Embedded Controller handle.
0026  * @dev: Device handle.
0027  * @mailbox_lock: Mutex to ensure one mailbox command at a time.
0028  * @io_command: I/O port for mailbox command.  Provided by ACPI.
0029  * @io_data: I/O port for mailbox data.  Provided by ACPI.
0030  * @io_packet: I/O port for mailbox packet data.  Provided by ACPI.
0031  * @data_buffer: Buffer used for EC communication.  The same buffer
0032  *               is used to hold the request and the response.
0033  * @data_size: Size of the data buffer used for EC communication.
0034  * @debugfs_pdev: The child platform_device used by the debugfs sub-driver.
0035  * @rtc_pdev: The child platform_device used by the RTC sub-driver.
0036  * @charger_pdev: Child platform_device used by the charger config sub-driver.
0037  * @telem_pdev: The child platform_device used by the telemetry sub-driver.
0038  */
0039 struct wilco_ec_device {
0040     struct device *dev;
0041     struct mutex mailbox_lock;
0042     struct resource *io_command;
0043     struct resource *io_data;
0044     struct resource *io_packet;
0045     void *data_buffer;
0046     size_t data_size;
0047     struct platform_device *debugfs_pdev;
0048     struct platform_device *rtc_pdev;
0049     struct platform_device *charger_pdev;
0050     struct platform_device *telem_pdev;
0051 };
0052
0053 /**
0054  * struct wilco_ec_request - Mailbox request message format.
0055  * @struct_version: Should be %EC_MAILBOX_PROTO_VERSION
0056  * @checksum: Sum of all bytes must be 0.
0057  * @mailbox_id: Mailbox identifier, specifies the command set.
0058  * @mailbox_version: Mailbox interface version %EC_MAILBOX_VERSION
0059  * @reserved: Set to zero.
0060  * @data_size: Length of following data.
0061  */
0062 struct wilco_ec_request {
0063     u8 struct_version;
0064     u8 checksum;
0065     u16 mailbox_id;
0066     u8 mailbox_version;
0067     u8 reserved;
0068     u16 data_size;
0069 } __packed;
0070
0071 /**
0072  * struct wilco_ec_response - Mailbox response message format.
0073  * @struct_version: Should be %EC_MAILBOX_PROTO_VERSION
0074  * @checksum: Sum of all bytes must be 0.
0075  * @result: Result code from the EC.  Non-zero indicates an error.
0076  * @data_size: Length of the response data buffer.
0077  * @reserved: Set to zero.
0078  * @data: Response data buffer.  Max size is %EC_MAILBOX_DATA_SIZE_EXTENDED.
0079  */
0080 struct wilco_ec_response {
0081     u8 struct_version;
0082     u8 checksum;
0083     u16 result;
0084     u16 data_size;
0085     u8 reserved[2];
0086     u8 data[];
0087 } __packed;
0088
0089 /**
0090  * enum wilco_ec_msg_type - Message type to select a set of command codes.
0091  * @WILCO_EC_MSG_LEGACY: Legacy EC messages for standard EC behavior.
0092  * @WILCO_EC_MSG_PROPERTY: Get/Set/Sync EC controlled NVRAM property.
0093  * @WILCO_EC_MSG_TELEMETRY: Request telemetry data from the EC.
0094  */
0095 enum wilco_ec_msg_type {
0096     WILCO_EC_MSG_LEGACY = 0x00f0,
0097     WILCO_EC_MSG_PROPERTY = 0x00f2,
0098     WILCO_EC_MSG_TELEMETRY = 0x00f5,
0099 };
0100
0101 /**
0102  * struct wilco_ec_message - Request and response message.
0103  * @type: Mailbox message type.
0104  * @flags: Message flags, e.g. %WILCO_EC_FLAG_NO_RESPONSE.
0105  * @request_size: Number of bytes to send to the EC.
0106  * @request_data: Buffer containing the request data.
0107  * @response_size: Number of bytes to read from EC.
0108  * @response_data: Buffer containing the response data, should be
0109  *                 response_size bytes and allocated by caller.
0110  */
0111 struct wilco_ec_message {
0112     enum wilco_ec_msg_type type;
0113     u8 flags;
0114     size_t request_size;
0115     void *request_data;
0116     size_t response_size;
0117     void *response_data;
0118 };
0119
0120 /**
0121  * wilco_ec_mailbox() - Send request to the EC and receive the response.
0122  * @ec: Wilco EC device.
0123  * @msg: Wilco EC message.
0124  *
0125  * Return: Number of bytes received or negative error code on failure.
0126  */
0127 int wilco_ec_mailbox(struct wilco_ec_device *ec, struct wilco_ec_message *msg);
0128
0129 /**
0130  * wilco_keyboard_leds_init() - Set up the keyboard backlight LEDs.
0131  * @ec: EC device to query.
0132  *
0133  * After this call, the keyboard backlight will be exposed through a an LED
0134  * device at /sys/class/leds.
0135  *
0136  * This may sleep because it uses wilco_ec_mailbox().
0137  *
0138  * Return: 0 on success, negative error code on failure.
0139  */
0140 int wilco_keyboard_leds_init(struct wilco_ec_device *ec);
0141
0142 /*
0143  * A Property is typically a data item that is stored to NVRAM
0144  * by the EC. Each of these data items has an index associated
0145  * with it, known as the Property ID (PID). Properties may have
0146  * variable lengths, up to a max of WILCO_EC_PROPERTY_MAX_SIZE
0147  * bytes. Properties can be simple integers, or they may be more
0148  * complex binary data.
0149  */
0150
0151 #define WILCO_EC_PROPERTY_MAX_SIZE  4
0152
0153 /**
0154  * struct ec_property_set_msg - Message to get or set a property.
0155  * @property_id: Which property to get or set.
0156  * @length: Number of bytes of |data| that are used.
0157  * @data: Actual property data.
0158  */
0159 struct wilco_ec_property_msg {
0160     u32 property_id;
0161     int length;
0162     u8 data[WILCO_EC_PROPERTY_MAX_SIZE];
0163 };
0164
0165 /**
0166  * wilco_ec_get_property() - Retrieve a property from the EC.
0167  * @ec: Embedded Controller device.
0168  * @prop_msg: Message for request and response.
0169  *
0170  * The property_id field of |prop_msg| should be filled before calling this
0171  * function. The result will be stored in the data and length fields.
0172  *
0173  * Return: 0 on success, negative error code on failure.
0174  */
0175 int wilco_ec_get_property(struct wilco_ec_device *ec,
0176               struct wilco_ec_property_msg *prop_msg);
0177
0178 /**
0179  * wilco_ec_set_property() - Store a property on the EC.
0180  * @ec: Embedded Controller device.
0181  * @prop_msg: Message for request and response.
0182  *
0183  * The property_id, length, and data fields of |prop_msg| should be
0184  * filled before calling this function.
0185  *
0186  * Return: 0 on success, negative error code on failure.
0187  */
0188 int wilco_ec_set_property(struct wilco_ec_device *ec,
0189               struct wilco_ec_property_msg *prop_msg);
0190
0191 /**
0192  * wilco_ec_get_byte_property() - Retrieve a byte-size property from the EC.
0193  * @ec: Embedded Controller device.
0194  * @property_id: Which property to retrieve.
0195  * @val: The result value, will be filled by this function.
0196  *
0197  * Return: 0 on success, negative error code on failure.
0198  */
0199 int wilco_ec_get_byte_property(struct wilco_ec_device *ec, u32 property_id,
0200                    u8 *val);
0201
0202 /**
0203  * wilco_ec_get_byte_property() - Store a byte-size property on the EC.
0204  * @ec: Embedded Controller device.
0205  * @property_id: Which property to store.
0206  * @val: Value to store.
0207  *
0208  * Return: 0 on success, negative error code on failure.
0209  */
0210 int wilco_ec_set_byte_property(struct wilco_ec_device *ec, u32 property_id,
0211                    u8 val);
0212
0213 /**
0214  * wilco_ec_add_sysfs() - Create sysfs entries
0215  * @ec: Wilco EC device
0216  *
0217  * wilco_ec_remove_sysfs() needs to be called afterwards
0218  * to perform the necessary cleanup.
0219  *
0220  * Return: 0 on success or negative error code on failure.
0221  */
0222 int wilco_ec_add_sysfs(struct wilco_ec_device *ec);
0223 void wilco_ec_remove_sysfs(struct wilco_ec_device *ec);
0224
0225 #endif /* WILCO_EC_H */