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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * ChromeOS EC multi-function device
4 *
5 * Copyright (C) 2012 Google, Inc
6 */
7
8#ifndef __LINUX_MFD_CROS_EC_H
9#define __LINUX_MFD_CROS_EC_H
10
11#include <linux/cdev.h>
12#include <linux/device.h>
13#include <linux/notifier.h>
14#include <linux/mfd/cros_ec_commands.h>
15#include <linux/mutex.h>
16
17#define CROS_EC_DEV_NAME "cros_ec"
18#define CROS_EC_DEV_FP_NAME "cros_fp"
19#define CROS_EC_DEV_PD_NAME "cros_pd"
20#define CROS_EC_DEV_TP_NAME "cros_tp"
21#define CROS_EC_DEV_ISH_NAME "cros_ish"
22
23/*
24 * The EC is unresponsive for a time after a reboot command. Add a
25 * simple delay to make sure that the bus stays locked.
26 */
27#define EC_REBOOT_DELAY_MS 50
28
29/*
30 * Max bus-specific overhead incurred by request/responses.
31 * I2C requires 1 additional byte for requests.
32 * I2C requires 2 additional bytes for responses.
33 * SPI requires up to 32 additional bytes for responses.
34 */
35#define EC_PROTO_VERSION_UNKNOWN 0
36#define EC_MAX_REQUEST_OVERHEAD 1
37#define EC_MAX_RESPONSE_OVERHEAD 32
38
39/*
40 * Command interface between EC and AP, for LPC, I2C and SPI interfaces.
41 */
42enum {
43 EC_MSG_TX_HEADER_BYTES = 3,
44 EC_MSG_TX_TRAILER_BYTES = 1,
45 EC_MSG_TX_PROTO_BYTES = EC_MSG_TX_HEADER_BYTES +
46 EC_MSG_TX_TRAILER_BYTES,
47 EC_MSG_RX_PROTO_BYTES = 3,
48
49 /* Max length of messages for proto 2*/
50 EC_PROTO2_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
51 EC_MSG_TX_PROTO_BYTES,
52
53 EC_MAX_MSG_BYTES = 64 * 1024,
54};
55
56/**
57 * struct cros_ec_command - Information about a ChromeOS EC command.
58 * @version: Command version number (often 0).
59 * @command: Command to send (EC_CMD_...).
60 * @outsize: Outgoing length in bytes.
61 * @insize: Max number of bytes to accept from the EC.
62 * @result: EC's response to the command (separate from communication failure).
63 * @data: Where to put the incoming data from EC and outgoing data to EC.
64 */
65struct cros_ec_command {
66 uint32_t version;
67 uint32_t command;
68 uint32_t outsize;
69 uint32_t insize;
70 uint32_t result;
71 uint8_t data[0];
72};
73
74/**
75 * struct cros_ec_device - Information about a ChromeOS EC device.
76 * @phys_name: Name of physical comms layer (e.g. 'i2c-4').
77 * @dev: Device pointer for physical comms device
78 * @was_wake_device: True if this device was set to wake the system from
79 * sleep at the last suspend.
80 * @cros_class: The class structure for this device.
81 * @cmd_readmem: Direct read of the EC memory-mapped region, if supported.
82 * @offset: Is within EC_LPC_ADDR_MEMMAP region.
83 * @bytes: Number of bytes to read. zero means "read a string" (including
84 * the trailing '\0'). At most only EC_MEMMAP_SIZE bytes can be
85 * read. Caller must ensure that the buffer is large enough for the
86 * result when reading a string.
87 * @max_request: Max size of message requested.
88 * @max_response: Max size of message response.
89 * @max_passthru: Max sice of passthru message.
90 * @proto_version: The protocol version used for this device.
91 * @priv: Private data.
92 * @irq: Interrupt to use.
93 * @id: Device id.
94 * @din: Input buffer (for data from EC). This buffer will always be
95 * dword-aligned and include enough space for up to 7 word-alignment
96 * bytes also, so we can ensure that the body of the message is always
97 * dword-aligned (64-bit). We use this alignment to keep ARM and x86
98 * happy. Probably word alignment would be OK, there might be a small
99 * performance advantage to using dword.
100 * @dout: Output buffer (for data to EC). This buffer will always be
101 * dword-aligned and include enough space for up to 7 word-alignment
102 * bytes also, so we can ensure that the body of the message is always
103 * dword-aligned (64-bit). We use this alignment to keep ARM and x86
104 * happy. Probably word alignment would be OK, there might be a small
105 * performance advantage to using dword.
106 * @din_size: Size of din buffer to allocate (zero to use static din).
107 * @dout_size: Size of dout buffer to allocate (zero to use static dout).
108 * @wake_enabled: True if this device can wake the system from sleep.
109 * @suspended: True if this device had been suspended.
110 * @cmd_xfer: Send command to EC and get response.
111 * Returns the number of bytes received if the communication
112 * succeeded, but that doesn't mean the EC was happy with the
113 * command. The caller should check msg.result for the EC's result
114 * code.
115 * @pkt_xfer: Send packet to EC and get response.
116 * @lock: One transaction at a time.
117 * @mkbp_event_supported: True if this EC supports the MKBP event protocol.
118 * @host_sleep_v1: True if this EC supports the sleep v1 command.
119 * @event_notifier: Interrupt event notifier for transport devices.
120 * @event_data: Raw payload transferred with the MKBP event.
121 * @event_size: Size in bytes of the event data.
122 * @host_event_wake_mask: Mask of host events that cause wake from suspend.
123 */
124struct cros_ec_device {
125 /* These are used by other drivers that want to talk to the EC */
126 const char *phys_name;
127 struct device *dev;
128 bool was_wake_device;
129 struct class *cros_class;
130 int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset,
131 unsigned int bytes, void *dest);
132
133 /* These are used to implement the platform-specific interface */
134 u16 max_request;
135 u16 max_response;
136 u16 max_passthru;
137 u16 proto_version;
138 void *priv;
139 int irq;
140 u8 *din;
141 u8 *dout;
142 int din_size;
143 int dout_size;
144 bool wake_enabled;
145 bool suspended;
146 int (*cmd_xfer)(struct cros_ec_device *ec,
147 struct cros_ec_command *msg);
148 int (*pkt_xfer)(struct cros_ec_device *ec,
149 struct cros_ec_command *msg);
150 struct mutex lock;
151 bool mkbp_event_supported;
152 bool host_sleep_v1;
153 struct blocking_notifier_head event_notifier;
154
155 struct ec_response_get_next_event_v1 event_data;
156 int event_size;
157 u32 host_event_wake_mask;
158};
159
160/**
161 * struct cros_ec_sensor_platform - ChromeOS EC sensor platform information.
162 * @sensor_num: Id of the sensor, as reported by the EC.
163 */
164struct cros_ec_sensor_platform {
165 u8 sensor_num;
166};
167
168/**
169 * struct cros_ec_platform - ChromeOS EC platform information.
170 * @ec_name: Name of EC device (e.g. 'cros-ec', 'cros-pd', ...)
171 * used in /dev/ and sysfs.
172 * @cmd_offset: Offset to apply for each command. Set when
173 * registering a device behind another one.
174 */
175struct cros_ec_platform {
176 const char *ec_name;
177 u16 cmd_offset;
178};
179
180struct cros_ec_debugfs;
181
182/**
183 * struct cros_ec_dev - ChromeOS EC device entry point.
184 * @class_dev: Device structure used in sysfs.
185 * @cdev: Character device structure in /dev.
186 * @ec_dev: cros_ec_device structure to talk to the physical device.
187 * @dev: Pointer to the platform device.
188 * @debug_info: cros_ec_debugfs structure for debugging information.
189 * @has_kb_wake_angle: True if at least 2 accelerometer are connected to the EC.
190 * @cmd_offset: Offset to apply for each command.
191 * @features: Features supported by the EC.
192 */
193struct cros_ec_dev {
194 struct device class_dev;
195 struct cdev cdev;
196 struct cros_ec_device *ec_dev;
197 struct device *dev;
198 struct cros_ec_debugfs *debug_info;
199 bool has_kb_wake_angle;
200 u16 cmd_offset;
201 u32 features[2];
202};
203
204#define to_cros_ec_dev(dev) container_of(dev, struct cros_ec_dev, class_dev)
205
206/**
207 * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device.
208 * @ec_dev: Device to suspend.
209 *
210 * This can be called by drivers to handle a suspend event.
211 *
212 * Return: 0 on success or negative error code.
213 */
214int cros_ec_suspend(struct cros_ec_device *ec_dev);
215
216/**
217 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device.
218 * @ec_dev: Device to resume.
219 *
220 * This can be called by drivers to handle a resume event.
221 *
222 * Return: 0 on success or negative error code.
223 */
224int cros_ec_resume(struct cros_ec_device *ec_dev);
225
226/**
227 * cros_ec_prepare_tx() - Prepare an outgoing message in the output buffer.
228 * @ec_dev: Device to register.
229 * @msg: Message to write.
230 *
231 * This is intended to be used by all ChromeOS EC drivers, but at present
232 * only SPI uses it. Once LPC uses the same protocol it can start using it.
233 * I2C could use it now, with a refactor of the existing code.
234 *
235 * Return: 0 on success or negative error code.
236 */
237int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
238 struct cros_ec_command *msg);
239
240/**
241 * cros_ec_check_result() - Check ec_msg->result.
242 * @ec_dev: EC device.
243 * @msg: Message to check.
244 *
245 * This is used by ChromeOS EC drivers to check the ec_msg->result for
246 * errors and to warn about them.
247 *
248 * Return: 0 on success or negative error code.
249 */
250int cros_ec_check_result(struct cros_ec_device *ec_dev,
251 struct cros_ec_command *msg);
252
253/**
254 * cros_ec_cmd_xfer() - Send a command to the ChromeOS EC.
255 * @ec_dev: EC device.
256 * @msg: Message to write.
257 *
258 * Call this to send a command to the ChromeOS EC. This should be used
259 * instead of calling the EC's cmd_xfer() callback directly.
260 *
261 * Return: 0 on success or negative error code.
262 */
263int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
264 struct cros_ec_command *msg);
265
266/**
267 * cros_ec_cmd_xfer_status() - Send a command to the ChromeOS EC.
268 * @ec_dev: EC device.
269 * @msg: Message to write.
270 *
271 * This function is identical to cros_ec_cmd_xfer, except it returns success
272 * status only if both the command was transmitted successfully and the EC
273 * replied with success status. It's not necessary to check msg->result when
274 * using this function.
275 *
276 * Return: The number of bytes transferred on success or negative error code.
277 */
278int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
279 struct cros_ec_command *msg);
280
281/**
282 * cros_ec_register() - Register a new ChromeOS EC, using the provided info.
283 * @ec_dev: Device to register.
284 *
285 * Before calling this, allocate a pointer to a new device and then fill
286 * in all the fields up to the --private-- marker.
287 *
288 * Return: 0 on success or negative error code.
289 */
290int cros_ec_register(struct cros_ec_device *ec_dev);
291
292/**
293 * cros_ec_query_all() - Query the protocol version supported by the
294 * ChromeOS EC.
295 * @ec_dev: Device to register.
296 *
297 * Return: 0 on success or negative error code.
298 */
299int cros_ec_query_all(struct cros_ec_device *ec_dev);
300
301/**
302 * cros_ec_get_next_event() - Fetch next event from the ChromeOS EC.
303 * @ec_dev: Device to fetch event from.
304 * @wake_event: Pointer to a bool set to true upon return if the event might be
305 * treated as a wake event. Ignored if null.
306 *
307 * Return: negative error code on errors; 0 for no data; or else number of
308 * bytes received (i.e., an event was retrieved successfully). Event types are
309 * written out to @ec_dev->event_data.event_type on success.
310 */
311int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event);
312
313/**
314 * cros_ec_get_host_event() - Return a mask of event set by the ChromeOS EC.
315 * @ec_dev: Device to fetch event from.
316 *
317 * When MKBP is supported, when the EC raises an interrupt, we collect the
318 * events raised and call the functions in the ec notifier. This function
319 * is a helper to know which events are raised.
320 *
321 * Return: 0 on error or non-zero bitmask of one or more EC_HOST_EVENT_*.
322 */
323u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);
324
325#endif /* __LINUX_MFD_CROS_EC_H */