1 // SPDX-License-Identifier: GPL-2.0
2 // ChromeOS EC communication protocol helper functions
3 //
4 // Copyright (C) 2015 Google, Inc
5
6 #include <linux/delay.h>
7 #include <linux/device.h>
8 #include <linux/module.h>
9 #include <linux/platform_data/cros_ec_commands.h>
10 #include <linux/platform_data/cros_ec_proto.h>
11 #include <linux/slab.h>
12 #include <asm/unaligned.h>
13
14 #include "cros_ec_trace.h"
15
16 #define EC_COMMAND_RETRIES 50
17
18 static const int cros_ec_error_map[] = {
19 [EC_RES_INVALID_COMMAND] = -EOPNOTSUPP,
20 [EC_RES_ERROR] = -EIO,
21 [EC_RES_INVALID_PARAM] = -EINVAL,
22 [EC_RES_ACCESS_DENIED] = -EACCES,
23 [EC_RES_INVALID_RESPONSE] = -EPROTO,
24 [EC_RES_INVALID_VERSION] = -ENOPROTOOPT,
25 [EC_RES_INVALID_CHECKSUM] = -EBADMSG,
26 [EC_RES_IN_PROGRESS] = -EINPROGRESS,
27 [EC_RES_UNAVAILABLE] = -ENODATA,
28 [EC_RES_TIMEOUT] = -ETIMEDOUT,
29 [EC_RES_OVERFLOW] = -EOVERFLOW,
30 [EC_RES_INVALID_HEADER] = -EBADR,
31 [EC_RES_REQUEST_TRUNCATED] = -EBADR,
32 [EC_RES_RESPONSE_TOO_BIG] = -EFBIG,
33 [EC_RES_BUS_ERROR] = -EFAULT,
34 [EC_RES_BUSY] = -EBUSY,
35 [EC_RES_INVALID_HEADER_VERSION] = -EBADMSG,
36 [EC_RES_INVALID_HEADER_CRC] = -EBADMSG,
37 [EC_RES_INVALID_DATA_CRC] = -EBADMSG,
38 [EC_RES_DUP_UNAVAILABLE] = -ENODATA,
39 };
40
cros_ec_map_error(uint32_t result)41 static int cros_ec_map_error(uint32_t result)
42 {
43 int ret = 0;
44
45 if (result != EC_RES_SUCCESS) {
46 if (result < ARRAY_SIZE(cros_ec_error_map) && cros_ec_error_map[result])
47 ret = cros_ec_error_map[result];
48 else
49 ret = -EPROTO;
50 }
51
52 return ret;
53 }
54
prepare_packet(struct cros_ec_device * ec_dev,struct cros_ec_command * msg)55 static int prepare_packet(struct cros_ec_device *ec_dev,
56 struct cros_ec_command *msg)
57 {
58 struct ec_host_request *request;
59 u8 *out;
60 int i;
61 u8 csum = 0;
62
63 BUG_ON(ec_dev->proto_version != EC_HOST_REQUEST_VERSION);
64 BUG_ON(msg->outsize + sizeof(*request) > ec_dev->dout_size);
65
66 out = ec_dev->dout;
67 request = (struct ec_host_request *)out;
68 request->struct_version = EC_HOST_REQUEST_VERSION;
69 request->checksum = 0;
70 request->command = msg->command;
71 request->command_version = msg->version;
72 request->reserved = 0;
73 request->data_len = msg->outsize;
74
75 for (i = 0; i < sizeof(*request); i++)
76 csum += out[i];
77
78 /* Copy data and update checksum */
79 memcpy(out + sizeof(*request), msg->data, msg->outsize);
80 for (i = 0; i < msg->outsize; i++)
81 csum += msg->data[i];
82
83 request->checksum = -csum;
84
85 return sizeof(*request) + msg->outsize;
86 }
87
send_command(struct cros_ec_device * ec_dev,struct cros_ec_command * msg)88 static int send_command(struct cros_ec_device *ec_dev,
89 struct cros_ec_command *msg)
90 {
91 int ret;
92 int (*xfer_fxn)(struct cros_ec_device *ec, struct cros_ec_command *msg);
93
94 if (ec_dev->proto_version > 2)
95 xfer_fxn = ec_dev->pkt_xfer;
96 else
97 xfer_fxn = ec_dev->cmd_xfer;
98
99 if (!xfer_fxn) {
100 /*
101 * This error can happen if a communication error happened and
102 * the EC is trying to use protocol v2, on an underlying
103 * communication mechanism that does not support v2.
104 */
105 dev_err_once(ec_dev->dev,
106 "missing EC transfer API, cannot send command\n");
107 return -EIO;
108 }
109
110 trace_cros_ec_request_start(msg);
111 ret = (*xfer_fxn)(ec_dev, msg);
112 trace_cros_ec_request_done(msg, ret);
113 if (msg->result == EC_RES_IN_PROGRESS) {
114 int i;
115 struct cros_ec_command *status_msg;
116 struct ec_response_get_comms_status *status;
117
118 status_msg = kmalloc(sizeof(*status_msg) + sizeof(*status),
119 GFP_KERNEL);
120 if (!status_msg)
121 return -ENOMEM;
122
123 status_msg->version = 0;
124 status_msg->command = EC_CMD_GET_COMMS_STATUS;
125 status_msg->insize = sizeof(*status);
126 status_msg->outsize = 0;
127
128 /*
129 * Query the EC's status until it's no longer busy or
130 * we encounter an error.
131 */
132 for (i = 0; i < EC_COMMAND_RETRIES; i++) {
133 usleep_range(10000, 11000);
134
135 trace_cros_ec_request_start(status_msg);
136 ret = (*xfer_fxn)(ec_dev, status_msg);
137 trace_cros_ec_request_done(status_msg, ret);
138 if (ret == -EAGAIN)
139 continue;
140 if (ret < 0)
141 break;
142
143 msg->result = status_msg->result;
144 if (status_msg->result != EC_RES_SUCCESS)
145 break;
146
147 status = (struct ec_response_get_comms_status *)
148 status_msg->data;
149 if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
150 break;
151 }
152
153 kfree(status_msg);
154 }
155
156 return ret;
157 }
158
159 /**
160 * cros_ec_prepare_tx() - Prepare an outgoing message in the output buffer.
161 * @ec_dev: Device to register.
162 * @msg: Message to write.
163 *
164 * This is intended to be used by all ChromeOS EC drivers, but at present
165 * only SPI uses it. Once LPC uses the same protocol it can start using it.
166 * I2C could use it now, with a refactor of the existing code.
167 *
168 * Return: 0 on success or negative error code.
169 */
cros_ec_prepare_tx(struct cros_ec_device * ec_dev,struct cros_ec_command * msg)170 int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
171 struct cros_ec_command *msg)
172 {
173 u8 *out;
174 u8 csum;
175 int i;
176
177 if (ec_dev->proto_version > 2)
178 return prepare_packet(ec_dev, msg);
179
180 BUG_ON(msg->outsize > EC_PROTO2_MAX_PARAM_SIZE);
181 out = ec_dev->dout;
182 out[0] = EC_CMD_VERSION0 + msg->version;
183 out[1] = msg->command;
184 out[2] = msg->outsize;
185 csum = out[0] + out[1] + out[2];
186 for (i = 0; i < msg->outsize; i++)
187 csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->data[i];
188 out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = csum;
189
190 return EC_MSG_TX_PROTO_BYTES + msg->outsize;
191 }
192 EXPORT_SYMBOL(cros_ec_prepare_tx);
193
194 /**
195 * cros_ec_check_result() - Check ec_msg->result.
196 * @ec_dev: EC device.
197 * @msg: Message to check.
198 *
199 * This is used by ChromeOS EC drivers to check the ec_msg->result for
200 * errors and to warn about them.
201 *
202 * Return: 0 on success or negative error code.
203 */
cros_ec_check_result(struct cros_ec_device * ec_dev,struct cros_ec_command * msg)204 int cros_ec_check_result(struct cros_ec_device *ec_dev,
205 struct cros_ec_command *msg)
206 {
207 switch (msg->result) {
208 case EC_RES_SUCCESS:
209 return 0;
210 case EC_RES_IN_PROGRESS:
211 dev_dbg(ec_dev->dev, "command 0x%02x in progress\n",
212 msg->command);
213 return -EAGAIN;
214 default:
215 dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n",
216 msg->command, msg->result);
217 return 0;
218 }
219 }
220 EXPORT_SYMBOL(cros_ec_check_result);
221
222 /*
223 * cros_ec_get_host_event_wake_mask
224 *
225 * Get the mask of host events that cause wake from suspend.
226 *
227 * @ec_dev: EC device to call
228 * @msg: message structure to use
229 * @mask: result when function returns >=0.
230 *
231 * LOCKING:
232 * the caller has ec_dev->lock mutex, or the caller knows there is
233 * no other command in progress.
234 */
cros_ec_get_host_event_wake_mask(struct cros_ec_device * ec_dev,struct cros_ec_command * msg,uint32_t * mask)235 static int cros_ec_get_host_event_wake_mask(struct cros_ec_device *ec_dev,
236 struct cros_ec_command *msg,
237 uint32_t *mask)
238 {
239 struct ec_response_host_event_mask *r;
240 int ret;
241
242 msg->command = EC_CMD_HOST_EVENT_GET_WAKE_MASK;
243 msg->version = 0;
244 msg->outsize = 0;
245 msg->insize = sizeof(*r);
246
247 ret = send_command(ec_dev, msg);
248 if (ret >= 0) {
249 if (msg->result == EC_RES_INVALID_COMMAND)
250 return -EOPNOTSUPP;
251 if (msg->result != EC_RES_SUCCESS)
252 return -EPROTO;
253 }
254 if (ret > 0) {
255 r = (struct ec_response_host_event_mask *)msg->data;
256 *mask = r->mask;
257 }
258
259 return ret;
260 }
261
cros_ec_host_command_proto_query(struct cros_ec_device * ec_dev,int devidx,struct cros_ec_command * msg)262 static int cros_ec_host_command_proto_query(struct cros_ec_device *ec_dev,
263 int devidx,
264 struct cros_ec_command *msg)
265 {
266 /*
267 * Try using v3+ to query for supported protocols. If this
268 * command fails, fall back to v2. Returns the highest protocol
269 * supported by the EC.
270 * Also sets the max request/response/passthru size.
271 */
272 int ret;
273
274 if (!ec_dev->pkt_xfer)
275 return -EPROTONOSUPPORT;
276
277 memset(msg, 0, sizeof(*msg));
278 msg->command = EC_CMD_PASSTHRU_OFFSET(devidx) | EC_CMD_GET_PROTOCOL_INFO;
279 msg->insize = sizeof(struct ec_response_get_protocol_info);
280
281 ret = send_command(ec_dev, msg);
282 /*
283 * Send command once again when timeout occurred.
284 * Fingerprint MCU (FPMCU) is restarted during system boot which
285 * introduces small window in which FPMCU won't respond for any
286 * messages sent by kernel. There is no need to wait before next
287 * attempt because we waited at least EC_MSG_DEADLINE_MS.
288 */
289 if (ret == -ETIMEDOUT)
290 ret = send_command(ec_dev, msg);
291
292 if (ret < 0) {
293 dev_dbg(ec_dev->dev,
294 "failed to check for EC[%d] protocol version: %d\n",
295 devidx, ret);
296 return ret;
297 }
298
299 if (devidx > 0 && msg->result == EC_RES_INVALID_COMMAND)
300 return -ENODEV;
301 else if (msg->result != EC_RES_SUCCESS)
302 return msg->result;
303
304 return 0;
305 }
306
cros_ec_host_command_proto_query_v2(struct cros_ec_device * ec_dev)307 static int cros_ec_host_command_proto_query_v2(struct cros_ec_device *ec_dev)
308 {
309 struct cros_ec_command *msg;
310 struct ec_params_hello *hello_params;
311 struct ec_response_hello *hello_response;
312 int ret;
313 int len = max(sizeof(*hello_params), sizeof(*hello_response));
314
315 msg = kmalloc(sizeof(*msg) + len, GFP_KERNEL);
316 if (!msg)
317 return -ENOMEM;
318
319 msg->version = 0;
320 msg->command = EC_CMD_HELLO;
321 hello_params = (struct ec_params_hello *)msg->data;
322 msg->outsize = sizeof(*hello_params);
323 hello_response = (struct ec_response_hello *)msg->data;
324 msg->insize = sizeof(*hello_response);
325
326 hello_params->in_data = 0xa0b0c0d0;
327
328 ret = send_command(ec_dev, msg);
329
330 if (ret < 0) {
331 dev_dbg(ec_dev->dev,
332 "EC failed to respond to v2 hello: %d\n",
333 ret);
334 goto exit;
335 } else if (msg->result != EC_RES_SUCCESS) {
336 dev_err(ec_dev->dev,
337 "EC responded to v2 hello with error: %d\n",
338 msg->result);
339 ret = msg->result;
340 goto exit;
341 } else if (hello_response->out_data != 0xa1b2c3d4) {
342 dev_err(ec_dev->dev,
343 "EC responded to v2 hello with bad result: %u\n",
344 hello_response->out_data);
345 ret = -EBADMSG;
346 goto exit;
347 }
348
349 ret = 0;
350
351 exit:
352 kfree(msg);
353 return ret;
354 }
355
356 /*
357 * cros_ec_get_host_command_version_mask
358 *
359 * Get the version mask of a given command.
360 *
361 * @ec_dev: EC device to call
362 * @msg: message structure to use
363 * @cmd: command to get the version of.
364 * @mask: result when function returns 0.
365 *
366 * @return 0 on success, error code otherwise
367 *
368 * LOCKING:
369 * the caller has ec_dev->lock mutex or the caller knows there is
370 * no other command in progress.
371 */
cros_ec_get_host_command_version_mask(struct cros_ec_device * ec_dev,u16 cmd,u32 * mask)372 static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
373 u16 cmd, u32 *mask)
374 {
375 struct ec_params_get_cmd_versions *pver;
376 struct ec_response_get_cmd_versions *rver;
377 struct cros_ec_command *msg;
378 int ret;
379
380 msg = kmalloc(sizeof(*msg) + max(sizeof(*rver), sizeof(*pver)),
381 GFP_KERNEL);
382 if (!msg)
383 return -ENOMEM;
384
385 msg->version = 0;
386 msg->command = EC_CMD_GET_CMD_VERSIONS;
387 msg->insize = sizeof(*rver);
388 msg->outsize = sizeof(*pver);
389
390 pver = (struct ec_params_get_cmd_versions *)msg->data;
391 pver->cmd = cmd;
392
393 ret = send_command(ec_dev, msg);
394 if (ret > 0) {
395 rver = (struct ec_response_get_cmd_versions *)msg->data;
396 *mask = rver->version_mask;
397 }
398
399 kfree(msg);
400
401 return ret;
402 }
403
404 /**
405 * cros_ec_query_all() - Query the protocol version supported by the
406 * ChromeOS EC.
407 * @ec_dev: Device to register.
408 *
409 * Return: 0 on success or negative error code.
410 */
cros_ec_query_all(struct cros_ec_device * ec_dev)411 int cros_ec_query_all(struct cros_ec_device *ec_dev)
412 {
413 struct device *dev = ec_dev->dev;
414 struct cros_ec_command *proto_msg;
415 struct ec_response_get_protocol_info *proto_info;
416 u32 ver_mask = 0;
417 int ret;
418
419 proto_msg = kzalloc(sizeof(*proto_msg) + sizeof(*proto_info),
420 GFP_KERNEL);
421 if (!proto_msg)
422 return -ENOMEM;
423
424 /* First try sending with proto v3. */
425 ec_dev->proto_version = 3;
426 ret = cros_ec_host_command_proto_query(ec_dev, 0, proto_msg);
427
428 if (ret == 0) {
429 proto_info = (struct ec_response_get_protocol_info *)
430 proto_msg->data;
431 ec_dev->max_request = proto_info->max_request_packet_size -
432 sizeof(struct ec_host_request);
433 ec_dev->max_response = proto_info->max_response_packet_size -
434 sizeof(struct ec_host_response);
435 ec_dev->proto_version =
436 min(EC_HOST_REQUEST_VERSION,
437 fls(proto_info->protocol_versions) - 1);
438 dev_dbg(ec_dev->dev,
439 "using proto v%u\n",
440 ec_dev->proto_version);
441
442 ec_dev->din_size = ec_dev->max_response +
443 sizeof(struct ec_host_response) +
444 EC_MAX_RESPONSE_OVERHEAD;
445 ec_dev->dout_size = ec_dev->max_request +
446 sizeof(struct ec_host_request) +
447 EC_MAX_REQUEST_OVERHEAD;
448
449 /*
450 * Check for PD
451 */
452 ret = cros_ec_host_command_proto_query(ec_dev, 1, proto_msg);
453
454 if (ret) {
455 dev_dbg(ec_dev->dev, "no PD chip found: %d\n", ret);
456 ec_dev->max_passthru = 0;
457 } else {
458 dev_dbg(ec_dev->dev, "found PD chip\n");
459 ec_dev->max_passthru =
460 proto_info->max_request_packet_size -
461 sizeof(struct ec_host_request);
462 }
463 } else {
464 /* Try querying with a v2 hello message. */
465 ec_dev->proto_version = 2;
466 ret = cros_ec_host_command_proto_query_v2(ec_dev);
467
468 if (ret == 0) {
469 /* V2 hello succeeded. */
470 dev_dbg(ec_dev->dev, "falling back to proto v2\n");
471
472 ec_dev->max_request = EC_PROTO2_MAX_PARAM_SIZE;
473 ec_dev->max_response = EC_PROTO2_MAX_PARAM_SIZE;
474 ec_dev->max_passthru = 0;
475 ec_dev->pkt_xfer = NULL;
476 ec_dev->din_size = EC_PROTO2_MSG_BYTES;
477 ec_dev->dout_size = EC_PROTO2_MSG_BYTES;
478 } else {
479 /*
480 * It's possible for a test to occur too early when
481 * the EC isn't listening. If this happens, we'll
482 * test later when the first command is run.
483 */
484 ec_dev->proto_version = EC_PROTO_VERSION_UNKNOWN;
485 dev_dbg(ec_dev->dev, "EC query failed: %d\n", ret);
486 goto exit;
487 }
488 }
489
490 devm_kfree(dev, ec_dev->din);
491 devm_kfree(dev, ec_dev->dout);
492
493 ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
494 if (!ec_dev->din) {
495 ret = -ENOMEM;
496 goto exit;
497 }
498
499 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
500 if (!ec_dev->dout) {
501 devm_kfree(dev, ec_dev->din);
502 ret = -ENOMEM;
503 goto exit;
504 }
505
506 /* Probe if MKBP event is supported */
507 ret = cros_ec_get_host_command_version_mask(ec_dev,
508 EC_CMD_GET_NEXT_EVENT,
509 &ver_mask);
510 if (ret < 0 || ver_mask == 0)
511 ec_dev->mkbp_event_supported = 0;
512 else
513 ec_dev->mkbp_event_supported = fls(ver_mask);
514
515 dev_dbg(ec_dev->dev, "MKBP support version %u\n",
516 ec_dev->mkbp_event_supported - 1);
517
518 /* Probe if host sleep v1 is supported for S0ix failure detection. */
519 ret = cros_ec_get_host_command_version_mask(ec_dev,
520 EC_CMD_HOST_SLEEP_EVENT,
521 &ver_mask);
522 ec_dev->host_sleep_v1 = (ret >= 0 && (ver_mask & EC_VER_MASK(1)));
523
524 /* Get host event wake mask. */
525 ret = cros_ec_get_host_event_wake_mask(ec_dev, proto_msg,
526 &ec_dev->host_event_wake_mask);
527 if (ret < 0) {
528 /*
529 * If the EC doesn't support EC_CMD_HOST_EVENT_GET_WAKE_MASK,
530 * use a reasonable default. Note that we ignore various
531 * battery, AC status, and power-state events, because (a)
532 * those can be quite common (e.g., when sitting at full
533 * charge, on AC) and (b) these are not actionable wake events;
534 * if anything, we'd like to continue suspending (to save
535 * power), not wake up.
536 */
537 ec_dev->host_event_wake_mask = U32_MAX &
538 ~(EC_HOST_EVENT_MASK(EC_HOST_EVENT_LID_CLOSED) |
539 EC_HOST_EVENT_MASK(EC_HOST_EVENT_AC_DISCONNECTED) |
540 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_LOW) |
541 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_CRITICAL) |
542 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY) |
543 EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
544 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_STATUS));
545 /*
546 * Old ECs may not support this command. Complain about all
547 * other errors.
548 */
549 if (ret != -EOPNOTSUPP)
550 dev_err(ec_dev->dev,
551 "failed to retrieve wake mask: %d\n", ret);
552 }
553
554 ret = 0;
555
556 exit:
557 kfree(proto_msg);
558 return ret;
559 }
560 EXPORT_SYMBOL(cros_ec_query_all);
561
562 /**
563 * cros_ec_cmd_xfer_status() - Send a command to the ChromeOS EC.
564 * @ec_dev: EC device.
565 * @msg: Message to write.
566 *
567 * Call this to send a command to the ChromeOS EC. This should be used instead of calling the EC's
568 * cmd_xfer() callback directly. It returns success status only if both the command was transmitted
569 * successfully and the EC replied with success status.
570 *
571 * Return:
572 * >=0 - The number of bytes transferred
573 * <0 - Linux error code
574 */
cros_ec_cmd_xfer_status(struct cros_ec_device * ec_dev,struct cros_ec_command * msg)575 int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
576 struct cros_ec_command *msg)
577 {
578 int ret, mapped;
579
580 mutex_lock(&ec_dev->lock);
581 if (ec_dev->proto_version == EC_PROTO_VERSION_UNKNOWN) {
582 ret = cros_ec_query_all(ec_dev);
583 if (ret) {
584 dev_err(ec_dev->dev,
585 "EC version unknown and query failed; aborting command\n");
586 mutex_unlock(&ec_dev->lock);
587 return ret;
588 }
589 }
590
591 if (msg->insize > ec_dev->max_response) {
592 dev_dbg(ec_dev->dev, "clamping message receive buffer\n");
593 msg->insize = ec_dev->max_response;
594 }
595
596 if (msg->command < EC_CMD_PASSTHRU_OFFSET(1)) {
597 if (msg->outsize > ec_dev->max_request) {
598 dev_err(ec_dev->dev,
599 "request of size %u is too big (max: %u)\n",
600 msg->outsize,
601 ec_dev->max_request);
602 mutex_unlock(&ec_dev->lock);
603 return -EMSGSIZE;
604 }
605 } else {
606 if (msg->outsize > ec_dev->max_passthru) {
607 dev_err(ec_dev->dev,
608 "passthru rq of size %u is too big (max: %u)\n",
609 msg->outsize,
610 ec_dev->max_passthru);
611 mutex_unlock(&ec_dev->lock);
612 return -EMSGSIZE;
613 }
614 }
615
616 ret = send_command(ec_dev, msg);
617 mutex_unlock(&ec_dev->lock);
618
619 mapped = cros_ec_map_error(msg->result);
620 if (mapped) {
621 dev_dbg(ec_dev->dev, "Command result (err: %d [%d])\n",
622 msg->result, mapped);
623 ret = mapped;
624 }
625
626 return ret;
627 }
628 EXPORT_SYMBOL(cros_ec_cmd_xfer_status);
629
get_next_event_xfer(struct cros_ec_device * ec_dev,struct cros_ec_command * msg,struct ec_response_get_next_event_v1 * event,int version,uint32_t size)630 static int get_next_event_xfer(struct cros_ec_device *ec_dev,
631 struct cros_ec_command *msg,
632 struct ec_response_get_next_event_v1 *event,
633 int version, uint32_t size)
634 {
635 int ret;
636
637 msg->version = version;
638 msg->command = EC_CMD_GET_NEXT_EVENT;
639 msg->insize = size;
640 msg->outsize = 0;
641
642 ret = cros_ec_cmd_xfer_status(ec_dev, msg);
643 if (ret > 0) {
644 ec_dev->event_size = ret - 1;
645 ec_dev->event_data = *event;
646 }
647
648 return ret;
649 }
650
get_next_event(struct cros_ec_device * ec_dev)651 static int get_next_event(struct cros_ec_device *ec_dev)
652 {
653 struct {
654 struct cros_ec_command msg;
655 struct ec_response_get_next_event_v1 event;
656 } __packed buf;
657 struct cros_ec_command *msg = &buf.msg;
658 struct ec_response_get_next_event_v1 *event = &buf.event;
659 const int cmd_version = ec_dev->mkbp_event_supported - 1;
660
661 memset(msg, 0, sizeof(*msg));
662 if (ec_dev->suspended) {
663 dev_dbg(ec_dev->dev, "Device suspended.\n");
664 return -EHOSTDOWN;
665 }
666
667 if (cmd_version == 0)
668 return get_next_event_xfer(ec_dev, msg, event, 0,
669 sizeof(struct ec_response_get_next_event));
670
671 return get_next_event_xfer(ec_dev, msg, event, cmd_version,
672 sizeof(struct ec_response_get_next_event_v1));
673 }
674
get_keyboard_state_event(struct cros_ec_device * ec_dev)675 static int get_keyboard_state_event(struct cros_ec_device *ec_dev)
676 {
677 u8 buffer[sizeof(struct cros_ec_command) +
678 sizeof(ec_dev->event_data.data)];
679 struct cros_ec_command *msg = (struct cros_ec_command *)&buffer;
680
681 msg->version = 0;
682 msg->command = EC_CMD_MKBP_STATE;
683 msg->insize = sizeof(ec_dev->event_data.data);
684 msg->outsize = 0;
685
686 ec_dev->event_size = cros_ec_cmd_xfer_status(ec_dev, msg);
687 ec_dev->event_data.event_type = EC_MKBP_EVENT_KEY_MATRIX;
688 memcpy(&ec_dev->event_data.data, msg->data,
689 sizeof(ec_dev->event_data.data));
690
691 return ec_dev->event_size;
692 }
693
694 /**
695 * cros_ec_get_next_event() - Fetch next event from the ChromeOS EC.
696 * @ec_dev: Device to fetch event from.
697 * @wake_event: Pointer to a bool set to true upon return if the event might be
698 * treated as a wake event. Ignored if null.
699 * @has_more_events: Pointer to bool set to true if more than one event is
700 * pending.
701 * Some EC will set this flag to indicate cros_ec_get_next_event()
702 * can be called multiple times in a row.
703 * It is an optimization to prevent issuing a EC command for
704 * nothing or wait for another interrupt from the EC to process
705 * the next message.
706 * Ignored if null.
707 *
708 * Return: negative error code on errors; 0 for no data; or else number of
709 * bytes received (i.e., an event was retrieved successfully). Event types are
710 * written out to @ec_dev->event_data.event_type on success.
711 */
cros_ec_get_next_event(struct cros_ec_device * ec_dev,bool * wake_event,bool * has_more_events)712 int cros_ec_get_next_event(struct cros_ec_device *ec_dev,
713 bool *wake_event,
714 bool *has_more_events)
715 {
716 u8 event_type;
717 u32 host_event;
718 int ret;
719
720 /*
721 * Default value for wake_event.
722 * Wake up on keyboard event, wake up for spurious interrupt or link
723 * error to the EC.
724 */
725 if (wake_event)
726 *wake_event = true;
727
728 /*
729 * Default value for has_more_events.
730 * EC will raise another interrupt if AP does not process all events
731 * anyway.
732 */
733 if (has_more_events)
734 *has_more_events = false;
735
736 if (!ec_dev->mkbp_event_supported)
737 return get_keyboard_state_event(ec_dev);
738
739 ret = get_next_event(ec_dev);
740 if (ret <= 0)
741 return ret;
742
743 if (has_more_events)
744 *has_more_events = ec_dev->event_data.event_type &
745 EC_MKBP_HAS_MORE_EVENTS;
746 ec_dev->event_data.event_type &= EC_MKBP_EVENT_TYPE_MASK;
747
748 if (wake_event) {
749 event_type = ec_dev->event_data.event_type;
750 host_event = cros_ec_get_host_event(ec_dev);
751
752 /*
753 * Sensor events need to be parsed by the sensor sub-device.
754 * Defer them, and don't report the wakeup here.
755 */
756 if (event_type == EC_MKBP_EVENT_SENSOR_FIFO)
757 *wake_event = false;
758 /* Masked host-events should not count as wake events. */
759 else if (host_event &&
760 !(host_event & ec_dev->host_event_wake_mask))
761 *wake_event = false;
762 }
763
764 return ret;
765 }
766 EXPORT_SYMBOL(cros_ec_get_next_event);
767
768 /**
769 * cros_ec_get_host_event() - Return a mask of event set by the ChromeOS EC.
770 * @ec_dev: Device to fetch event from.
771 *
772 * When MKBP is supported, when the EC raises an interrupt, we collect the
773 * events raised and call the functions in the ec notifier. This function
774 * is a helper to know which events are raised.
775 *
776 * Return: 0 on error or non-zero bitmask of one or more EC_HOST_EVENT_*.
777 */
cros_ec_get_host_event(struct cros_ec_device * ec_dev)778 u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev)
779 {
780 u32 host_event;
781
782 BUG_ON(!ec_dev->mkbp_event_supported);
783
784 if (ec_dev->event_data.event_type != EC_MKBP_EVENT_HOST_EVENT)
785 return 0;
786
787 if (ec_dev->event_size != sizeof(host_event)) {
788 dev_warn(ec_dev->dev, "Invalid host event size\n");
789 return 0;
790 }
791
792 host_event = get_unaligned_le32(&ec_dev->event_data.data.host_event);
793
794 return host_event;
795 }
796 EXPORT_SYMBOL(cros_ec_get_host_event);
797
798 /**
799 * cros_ec_check_features() - Test for the presence of EC features
800 *
801 * @ec: EC device, does not have to be connected directly to the AP,
802 * can be daisy chained through another device.
803 * @feature: One of ec_feature_code bit.
804 *
805 * Call this function to test whether the ChromeOS EC supports a feature.
806 *
807 * Return: 1 if supported, 0 if not
808 */
cros_ec_check_features(struct cros_ec_dev * ec,int feature)809 int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
810 {
811 struct cros_ec_command *msg;
812 int ret;
813
814 if (ec->features[0] == -1U && ec->features[1] == -1U) {
815 /* features bitmap not read yet */
816 msg = kzalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
817 if (!msg)
818 return -ENOMEM;
819
820 msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
821 msg->insize = sizeof(ec->features);
822
823 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
824 if (ret < 0) {
825 dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
826 ret, msg->result);
827 memset(ec->features, 0, sizeof(ec->features));
828 } else {
829 memcpy(ec->features, msg->data, sizeof(ec->features));
830 }
831
832 dev_dbg(ec->dev, "EC features %08x %08x\n",
833 ec->features[0], ec->features[1]);
834
835 kfree(msg);
836 }
837
838 return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
839 }
840 EXPORT_SYMBOL_GPL(cros_ec_check_features);
841
842 /**
843 * cros_ec_get_sensor_count() - Return the number of MEMS sensors supported.
844 *
845 * @ec: EC device, does not have to be connected directly to the AP,
846 * can be daisy chained through another device.
847 * Return: < 0 in case of error.
848 */
cros_ec_get_sensor_count(struct cros_ec_dev * ec)849 int cros_ec_get_sensor_count(struct cros_ec_dev *ec)
850 {
851 /*
852 * Issue a command to get the number of sensor reported.
853 * If not supported, check for legacy mode.
854 */
855 int ret, sensor_count;
856 struct ec_params_motion_sense *params;
857 struct ec_response_motion_sense *resp;
858 struct cros_ec_command *msg;
859 struct cros_ec_device *ec_dev = ec->ec_dev;
860 u8 status;
861
862 msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*resp)),
863 GFP_KERNEL);
864 if (!msg)
865 return -ENOMEM;
866
867 msg->version = 1;
868 msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
869 msg->outsize = sizeof(*params);
870 msg->insize = sizeof(*resp);
871
872 params = (struct ec_params_motion_sense *)msg->data;
873 params->cmd = MOTIONSENSE_CMD_DUMP;
874
875 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
876 if (ret < 0) {
877 sensor_count = ret;
878 } else {
879 resp = (struct ec_response_motion_sense *)msg->data;
880 sensor_count = resp->dump.sensor_count;
881 }
882 kfree(msg);
883
884 /*
885 * Check legacy mode: Let's find out if sensors are accessible
886 * via LPC interface.
887 */
888 if (sensor_count < 0 && ec->cmd_offset == 0 && ec_dev->cmd_readmem) {
889 ret = ec_dev->cmd_readmem(ec_dev, EC_MEMMAP_ACC_STATUS,
890 1, &status);
891 if (ret >= 0 &&
892 (status & EC_MEMMAP_ACC_STATUS_PRESENCE_BIT)) {
893 /*
894 * We have 2 sensors, one in the lid, one in the base.
895 */
896 sensor_count = 2;
897 } else {
898 /*
899 * EC uses LPC interface and no sensors are presented.
900 */
901 sensor_count = 0;
902 }
903 }
904 return sensor_count;
905 }
906 EXPORT_SYMBOL_GPL(cros_ec_get_sensor_count);
907