1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * ChromeOS Wilco Embedded Controller
4 *
5 * Copyright 2018 Google LLC
6 */
7
8#ifndef WILCO_EC_H
9#define WILCO_EC_H
10
11#include <linux/mutex.h>
12#include <linux/types.h>
13
14/* Message flags for using the mailbox() interface */
15#define WILCO_EC_FLAG_NO_RESPONSE BIT(0) /* EC does not respond */
16
17/* Normal commands have a maximum 32 bytes of data */
18#define EC_MAILBOX_DATA_SIZE 32
19
20struct device;
21struct resource;
22struct platform_device;
23
24/**
25 * struct wilco_ec_device - Wilco Embedded Controller handle.
26 * @dev: Device handle.
27 * @mailbox_lock: Mutex to ensure one mailbox command at a time.
28 * @io_command: I/O port for mailbox command. Provided by ACPI.
29 * @io_data: I/O port for mailbox data. Provided by ACPI.
30 * @io_packet: I/O port for mailbox packet data. Provided by ACPI.
31 * @data_buffer: Buffer used for EC communication. The same buffer
32 * is used to hold the request and the response.
33 * @data_size: Size of the data buffer used for EC communication.
34 * @debugfs_pdev: The child platform_device used by the debugfs sub-driver.
35 * @rtc_pdev: The child platform_device used by the RTC sub-driver.
36 * @charger_pdev: Child platform_device used by the charger config sub-driver.
37 * @telem_pdev: The child platform_device used by the telemetry sub-driver.
38 */
39struct wilco_ec_device {
40 struct device *dev;
41 struct mutex mailbox_lock;
42 struct resource *io_command;
43 struct resource *io_data;
44 struct resource *io_packet;
45 void *data_buffer;
46 size_t data_size;
47 struct platform_device *debugfs_pdev;
48 struct platform_device *rtc_pdev;
49 struct platform_device *charger_pdev;
50 struct platform_device *telem_pdev;
51};
52
53/**
54 * struct wilco_ec_request - Mailbox request message format.
55 * @struct_version: Should be %EC_MAILBOX_PROTO_VERSION
56 * @checksum: Sum of all bytes must be 0.
57 * @mailbox_id: Mailbox identifier, specifies the command set.
58 * @mailbox_version: Mailbox interface version %EC_MAILBOX_VERSION
59 * @reserved: Set to zero.
60 * @data_size: Length of following data.
61 */
62struct wilco_ec_request {
63 u8 struct_version;
64 u8 checksum;
65 u16 mailbox_id;
66 u8 mailbox_version;
67 u8 reserved;
68 u16 data_size;
69} __packed;
70
71/**
72 * struct wilco_ec_response - Mailbox response message format.
73 * @struct_version: Should be %EC_MAILBOX_PROTO_VERSION
74 * @checksum: Sum of all bytes must be 0.
75 * @result: Result code from the EC. Non-zero indicates an error.
76 * @data_size: Length of the response data buffer.
77 * @reserved: Set to zero.
78 * @data: Response data buffer. Max size is %EC_MAILBOX_DATA_SIZE_EXTENDED.
79 */
80struct wilco_ec_response {
81 u8 struct_version;
82 u8 checksum;
83 u16 result;
84 u16 data_size;
85 u8 reserved[2];
86 u8 data[];
87} __packed;
88
89/**
90 * enum wilco_ec_msg_type - Message type to select a set of command codes.
91 * @WILCO_EC_MSG_LEGACY: Legacy EC messages for standard EC behavior.
92 * @WILCO_EC_MSG_PROPERTY: Get/Set/Sync EC controlled NVRAM property.
93 * @WILCO_EC_MSG_TELEMETRY: Request telemetry data from the EC.
94 */
95enum wilco_ec_msg_type {
96 WILCO_EC_MSG_LEGACY = 0x00f0,
97 WILCO_EC_MSG_PROPERTY = 0x00f2,
98 WILCO_EC_MSG_TELEMETRY = 0x00f5,
99};
100
101/**
102 * struct wilco_ec_message - Request and response message.
103 * @type: Mailbox message type.
104 * @flags: Message flags, e.g. %WILCO_EC_FLAG_NO_RESPONSE.
105 * @request_size: Number of bytes to send to the EC.
106 * @request_data: Buffer containing the request data.
107 * @response_size: Number of bytes to read from EC.
108 * @response_data: Buffer containing the response data, should be
109 * response_size bytes and allocated by caller.
110 */
111struct wilco_ec_message {
112 enum wilco_ec_msg_type type;
113 u8 flags;
114 size_t request_size;
115 void *request_data;
116 size_t response_size;
117 void *response_data;
118};
119
120/**
121 * wilco_ec_mailbox() - Send request to the EC and receive the response.
122 * @ec: Wilco EC device.
123 * @msg: Wilco EC message.
124 *
125 * Return: Number of bytes received or negative error code on failure.
126 */
127int wilco_ec_mailbox(struct wilco_ec_device *ec, struct wilco_ec_message *msg);
128
129/**
130 * wilco_keyboard_leds_init() - Set up the keyboard backlight LEDs.
131 * @ec: EC device to query.
132 *
133 * After this call, the keyboard backlight will be exposed through a an LED
134 * device at /sys/class/leds.
135 *
136 * This may sleep because it uses wilco_ec_mailbox().
137 *
138 * Return: 0 on success, negative error code on failure.
139 */
140int wilco_keyboard_leds_init(struct wilco_ec_device *ec);
141
142/*
143 * A Property is typically a data item that is stored to NVRAM
144 * by the EC. Each of these data items has an index associated
145 * with it, known as the Property ID (PID). Properties may have
146 * variable lengths, up to a max of WILCO_EC_PROPERTY_MAX_SIZE
147 * bytes. Properties can be simple integers, or they may be more
148 * complex binary data.
149 */
150
151#define WILCO_EC_PROPERTY_MAX_SIZE 4
152
153/**
154 * struct ec_property_set_msg - Message to get or set a property.
155 * @property_id: Which property to get or set.
156 * @length: Number of bytes of |data| that are used.
157 * @data: Actual property data.
158 */
159struct wilco_ec_property_msg {
160 u32 property_id;
161 int length;
162 u8 data[WILCO_EC_PROPERTY_MAX_SIZE];
163};
164
165/**
166 * wilco_ec_get_property() - Retrieve a property from the EC.
167 * @ec: Embedded Controller device.
168 * @prop_msg: Message for request and response.
169 *
170 * The property_id field of |prop_msg| should be filled before calling this
171 * function. The result will be stored in the data and length fields.
172 *
173 * Return: 0 on success, negative error code on failure.
174 */
175int wilco_ec_get_property(struct wilco_ec_device *ec,
176 struct wilco_ec_property_msg *prop_msg);
177
178/**
179 * wilco_ec_set_property() - Store a property on the EC.
180 * @ec: Embedded Controller device.
181 * @prop_msg: Message for request and response.
182 *
183 * The property_id, length, and data fields of |prop_msg| should be
184 * filled before calling this function.
185 *
186 * Return: 0 on success, negative error code on failure.
187 */
188int wilco_ec_set_property(struct wilco_ec_device *ec,
189 struct wilco_ec_property_msg *prop_msg);
190
191/**
192 * wilco_ec_get_byte_property() - Retrieve a byte-size property from the EC.
193 * @ec: Embedded Controller device.
194 * @property_id: Which property to retrieve.
195 * @val: The result value, will be filled by this function.
196 *
197 * Return: 0 on success, negative error code on failure.
198 */
199int wilco_ec_get_byte_property(struct wilco_ec_device *ec, u32 property_id,
200 u8 *val);
201
202/**
203 * wilco_ec_get_byte_property() - Store a byte-size property on the EC.
204 * @ec: Embedded Controller device.
205 * @property_id: Which property to store.
206 * @val: Value to store.
207 *
208 * Return: 0 on success, negative error code on failure.
209 */
210int wilco_ec_set_byte_property(struct wilco_ec_device *ec, u32 property_id,
211 u8 val);
212
213/**
214 * wilco_ec_add_sysfs() - Create sysfs entries
215 * @ec: Wilco EC device
216 *
217 * wilco_ec_remove_sysfs() needs to be called afterwards
218 * to perform the necessary cleanup.
219 *
220 * Return: 0 on success or negative error code on failure.
221 */
222int wilco_ec_add_sysfs(struct wilco_ec_device *ec);
223void wilco_ec_remove_sysfs(struct wilco_ec_device *ec);
224
225#endif /* WILCO_EC_H */
226

source code of linux/include/linux/platform_data/wilco-ec.h