summaryrefslogtreecommitdiff
path: root/include/linux/mfd/cros_ec.h
blob: cfa78bb4990f7547470e9ebcfd0183ad13295e77 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
/*
 * ChromeOS EC multi-function device
 *
 * Copyright (C) 2012 Google, Inc
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#ifndef __LINUX_MFD_CROS_EC_H
#define __LINUX_MFD_CROS_EC_H

#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/notifier.h>
#include <linux/mfd/cros_ec_commands.h>
#include <linux/mutex.h>

#define CROS_EC_DEV_NAME "cros_ec"
#define CROS_EC_DEV_FP_NAME "cros_fp"
#define CROS_EC_DEV_PD_NAME "cros_pd"
#define CROS_EC_DEV_TP_NAME "cros_tp"
#define CROS_EC_DEV_ISH_NAME "cros_ish"

/*
 * The EC is unresponsive for a time after a reboot command.  Add a
 * simple delay to make sure that the bus stays locked.
 */
#define EC_REBOOT_DELAY_MS             50

/*
 * Max bus-specific overhead incurred by request/responses.
 * I2C requires 1 additional byte for requests.
 * I2C requires 2 additional bytes for responses.
 * SPI requires up to 32 additional bytes for responses.
 */
#define EC_PROTO_VERSION_UNKNOWN	0
#define EC_MAX_REQUEST_OVERHEAD		1
#define EC_MAX_RESPONSE_OVERHEAD	32

/*
 * Command interface between EC and AP, for LPC, I2C and SPI interfaces.
 */
enum {
	EC_MSG_TX_HEADER_BYTES	= 3,
	EC_MSG_TX_TRAILER_BYTES	= 1,
	EC_MSG_TX_PROTO_BYTES	= EC_MSG_TX_HEADER_BYTES +
					EC_MSG_TX_TRAILER_BYTES,
	EC_MSG_RX_PROTO_BYTES	= 3,

	/* Max length of messages for proto 2*/
	EC_PROTO2_MSG_BYTES		= EC_PROTO2_MAX_PARAM_SIZE +
					EC_MSG_TX_PROTO_BYTES,

	EC_MAX_MSG_BYTES		= 64 * 1024,
};

/**
 * struct cros_ec_command - Information about a ChromeOS EC command.
 * @version: Command version number (often 0).
 * @command: Command to send (EC_CMD_...).
 * @outsize: Outgoing length in bytes.
 * @insize: Max number of bytes to accept from the EC.
 * @result: EC's response to the command (separate from communication failure).
 * @data: Where to put the incoming data from EC and outgoing data to EC.
 */
struct cros_ec_command {
	uint32_t version;
	uint32_t command;
	uint32_t outsize;
	uint32_t insize;
	uint32_t result;
	uint8_t data[0];
};

/**
 * struct cros_ec_device - Information about a ChromeOS EC device.
 * @phys_name: Name of physical comms layer (e.g. 'i2c-4').
 * @dev: Device pointer for physical comms device
 * @was_wake_device: True if this device was set to wake the system from
 *                   sleep at the last suspend.
 * @cros_class: The class structure for this device.
 * @cmd_readmem: Direct read of the EC memory-mapped region, if supported.
 *     @offset: Is within EC_LPC_ADDR_MEMMAP region.
 *     @bytes: Number of bytes to read. zero means "read a string" (including
 *             the trailing '\0'). At most only EC_MEMMAP_SIZE bytes can be
 *             read. Caller must ensure that the buffer is large enough for the
 *             result when reading a string.
 * @max_request: Max size of message requested.
 * @max_response: Max size of message response.
 * @max_passthru: Max sice of passthru message.
 * @proto_version: The protocol version used for this device.
 * @priv: Private data.
 * @irq: Interrupt to use.
 * @id: Device id.
 * @din: Input buffer (for data from EC). This buffer will always be
 *       dword-aligned and include enough space for up to 7 word-alignment
 *       bytes also, so we can ensure that the body of the message is always
 *       dword-aligned (64-bit). We use this alignment to keep ARM and x86
 *       happy. Probably word alignment would be OK, there might be a small
 *       performance advantage to using dword.
 * @dout: Output buffer (for data to EC). This buffer will always be
 *        dword-aligned and include enough space for up to 7 word-alignment
 *        bytes also, so we can ensure that the body of the message is always
 *        dword-aligned (64-bit). We use this alignment to keep ARM and x86
 *        happy. Probably word alignment would be OK, there might be a small
 *        performance advantage to using dword.
 * @din_size: Size of din buffer to allocate (zero to use static din).
 * @dout_size: Size of dout buffer to allocate (zero to use static dout).
 * @wake_enabled: True if this device can wake the system from sleep.
 * @suspended: True if this device had been suspended.
 * @cmd_xfer: Send command to EC and get response.
 *            Returns the number of bytes received if the communication
 *            succeeded, but that doesn't mean the EC was happy with the
 *            command. The caller should check msg.result for the EC's result
 *            code.
 * @pkt_xfer: Send packet to EC and get response.
 * @lock: One transaction at a time.
 * @mkbp_event_supported: True if this EC supports the MKBP event protocol.
 * @host_sleep_v1: True if this EC supports the sleep v1 command.
 * @event_notifier: Interrupt event notifier for transport devices.
 * @event_data: Raw payload transferred with the MKBP event.
 * @event_size: Size in bytes of the event data.
 * @host_event_wake_mask: Mask of host events that cause wake from suspend.
 */
struct cros_ec_device {
	/* These are used by other drivers that want to talk to the EC */
	const char *phys_name;
	struct device *dev;
	bool was_wake_device;
	struct class *cros_class;
	int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset,
			   unsigned int bytes, void *dest);

	/* These are used to implement the platform-specific interface */
	u16 max_request;
	u16 max_response;
	u16 max_passthru;
	u16 proto_version;
	void *priv;
	int irq;
	u8 *din;
	u8 *dout;
	int din_size;
	int dout_size;
	bool wake_enabled;
	bool suspended;
	int (*cmd_xfer)(struct cros_ec_device *ec,
			struct cros_ec_command *msg);
	int (*pkt_xfer)(struct cros_ec_device *ec,
			struct cros_ec_command *msg);
	struct mutex lock;
	bool mkbp_event_supported;
	bool host_sleep_v1;
	struct blocking_notifier_head event_notifier;

	struct ec_response_get_next_event_v1 event_data;
	int event_size;
	u32 host_event_wake_mask;
};

/**
 * struct cros_ec_sensor_platform - ChromeOS EC sensor platform information.
 * @sensor_num: Id of the sensor, as reported by the EC.
 */
struct cros_ec_sensor_platform {
	u8 sensor_num;
};

/**
 * struct cros_ec_platform - ChromeOS EC platform information.
 * @ec_name: Name of EC device (e.g. 'cros-ec', 'cros-pd', ...)
 *           used in /dev/ and sysfs.
 * @cmd_offset: Offset to apply for each command. Set when
 *              registering a device behind another one.
 */
struct cros_ec_platform {
	const char *ec_name;
	u16 cmd_offset;
};

struct cros_ec_debugfs;

/**
 * struct cros_ec_dev - ChromeOS EC device entry point.
 * @class_dev: Device structure used in sysfs.
 * @cdev: Character device structure in /dev.
 * @ec_dev: cros_ec_device structure to talk to the physical device.
 * @dev: Pointer to the platform device.
 * @debug_info: cros_ec_debugfs structure for debugging information.
 * @has_kb_wake_angle: True if at least 2 accelerometer are connected to the EC.
 * @cmd_offset: Offset to apply for each command.
 * @features: Features supported by the EC.
 */
struct cros_ec_dev {
	struct device class_dev;
	struct cdev cdev;
	struct cros_ec_device *ec_dev;
	struct device *dev;
	struct cros_ec_debugfs *debug_info;
	bool has_kb_wake_angle;
	u16 cmd_offset;
	u32 features[2];
};

#define to_cros_ec_dev(dev)  container_of(dev, struct cros_ec_dev, class_dev)

/**
 * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device.
 * @ec_dev: Device to suspend.
 *
 * This can be called by drivers to handle a suspend event.
 *
 * Return: 0 on success or negative error code.
 */
int cros_ec_suspend(struct cros_ec_device *ec_dev);

/**
 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device.
 * @ec_dev: Device to resume.
 *
 * This can be called by drivers to handle a resume event.
 *
 * Return: 0 on success or negative error code.
 */
int cros_ec_resume(struct cros_ec_device *ec_dev);

/**
 * cros_ec_prepare_tx() - Prepare an outgoing message in the output buffer.
 * @ec_dev: Device to register.
 * @msg: Message to write.
 *
 * This is intended to be used by all ChromeOS EC drivers, but at present
 * only SPI uses it. Once LPC uses the same protocol it can start using it.
 * I2C could use it now, with a refactor of the existing code.
 *
 * Return: 0 on success or negative error code.
 */
int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
		       struct cros_ec_command *msg);

/**
 * cros_ec_check_result() - Check ec_msg->result.
 * @ec_dev: EC device.
 * @msg: Message to check.
 *
 * This is used by ChromeOS EC drivers to check the ec_msg->result for
 * errors and to warn about them.
 *
 * Return: 0 on success or negative error code.
 */
int cros_ec_check_result(struct cros_ec_device *ec_dev,
			 struct cros_ec_command *msg);

/**
 * cros_ec_cmd_xfer() - Send a command to the ChromeOS EC.
 * @ec_dev: EC device.
 * @msg: Message to write.
 *
 * Call this to send a command to the ChromeOS EC.  This should be used
 * instead of calling the EC's cmd_xfer() callback directly.
 *
 * Return: 0 on success or negative error code.
 */
int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
		     struct cros_ec_command *msg);

/**
 * cros_ec_cmd_xfer_status() - Send a command to the ChromeOS EC.
 * @ec_dev: EC device.
 * @msg: Message to write.
 *
 * This function is identical to cros_ec_cmd_xfer, except it returns success
 * status only if both the command was transmitted successfully and the EC
 * replied with success status. It's not necessary to check msg->result when
 * using this function.
 *
 * Return: The number of bytes transferred on success or negative error code.
 */
int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
			    struct cros_ec_command *msg);

/**
 * cros_ec_register() - Register a new ChromeOS EC, using the provided info.
 * @ec_dev: Device to register.
 *
 * Before calling this, allocate a pointer to a new device and then fill
 * in all the fields up to the --private-- marker.
 *
 * Return: 0 on success or negative error code.
 */
int cros_ec_register(struct cros_ec_device *ec_dev);

/**
 * cros_ec_query_all() -  Query the protocol version supported by the
 *         ChromeOS EC.
 * @ec_dev: Device to register.
 *
 * Return: 0 on success or negative error code.
 */
int cros_ec_query_all(struct cros_ec_device *ec_dev);

/**
 * cros_ec_get_next_event() - Fetch next event from the ChromeOS EC.
 * @ec_dev: Device to fetch event from.
 * @wake_event: Pointer to a bool set to true upon return if the event might be
 *              treated as a wake event. Ignored if null.
 *
 * Return: negative error code on errors; 0 for no data; or else number of
 * bytes received (i.e., an event was retrieved successfully). Event types are
 * written out to @ec_dev->event_data.event_type on success.
 */
int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event);

/**
 * cros_ec_get_host_event() - Return a mask of event set by the ChromeOS EC.
 * @ec_dev: Device to fetch event from.
 *
 * When MKBP is supported, when the EC raises an interrupt, we collect the
 * events raised and call the functions in the ec notifier. This function
 * is a helper to know which events are raised.
 *
 * Return: 0 on error or non-zero bitmask of one or more EC_HOST_EVENT_*.
 */
u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);

#endif /* __LINUX_MFD_CROS_EC_H */