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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/limits.h>
9#include <linux/module.h>
10#include <linux/platform_data/cros_ec_commands.h>
11#include <linux/platform_data/cros_ec_proto.h>
12#include <linux/slab.h>
13#include <linux/unaligned.h>
14
15#include "cros_ec_trace.h"
16
17#define EC_COMMAND_RETRIES 50
18
19static const int cros_ec_error_map[] = {
20 [EC_RES_INVALID_COMMAND] = -EOPNOTSUPP,
21 [EC_RES_ERROR] = -EIO,
22 [EC_RES_INVALID_PARAM] = -EINVAL,
23 [EC_RES_ACCESS_DENIED] = -EACCES,
24 [EC_RES_INVALID_RESPONSE] = -EPROTO,
25 [EC_RES_INVALID_VERSION] = -ENOPROTOOPT,
26 [EC_RES_INVALID_CHECKSUM] = -EBADMSG,
27 [EC_RES_IN_PROGRESS] = -EINPROGRESS,
28 [EC_RES_UNAVAILABLE] = -ENODATA,
29 [EC_RES_TIMEOUT] = -ETIMEDOUT,
30 [EC_RES_OVERFLOW] = -EOVERFLOW,
31 [EC_RES_INVALID_HEADER] = -EBADR,
32 [EC_RES_REQUEST_TRUNCATED] = -EBADR,
33 [EC_RES_RESPONSE_TOO_BIG] = -EFBIG,
34 [EC_RES_BUS_ERROR] = -EFAULT,
35 [EC_RES_BUSY] = -EBUSY,
36 [EC_RES_INVALID_HEADER_VERSION] = -EBADMSG,
37 [EC_RES_INVALID_HEADER_CRC] = -EBADMSG,
38 [EC_RES_INVALID_DATA_CRC] = -EBADMSG,
39 [EC_RES_DUP_UNAVAILABLE] = -ENODATA,
40};
41
42static int cros_ec_map_error(uint32_t result)
43{
44 int ret = 0;
45
46 if (result != EC_RES_SUCCESS) {
47 if (result < ARRAY_SIZE(cros_ec_error_map) && cros_ec_error_map[result])
48 ret = cros_ec_error_map[result];
49 else
50 ret = -EPROTO;
51 }
52
53 return ret;
54}
55
56static int prepare_tx(struct cros_ec_device *ec_dev,
57 struct cros_ec_command *msg)
58{
59 struct ec_host_request *request;
60 u8 *out;
61 int i;
62 u8 csum = 0;
63
64 if (msg->outsize + sizeof(*request) > ec_dev->dout_size)
65 return -EINVAL;
66
67 out = ec_dev->dout;
68 request = (struct ec_host_request *)out;
69 request->struct_version = EC_HOST_REQUEST_VERSION;
70 request->checksum = 0;
71 request->command = msg->command;
72 request->command_version = msg->version;
73 request->reserved = 0;
74 request->data_len = msg->outsize;
75
76 for (i = 0; i < sizeof(*request); i++)
77 csum += out[i];
78
79 /* Copy data and update checksum */
80 memcpy(out + sizeof(*request), msg->data, msg->outsize);
81 for (i = 0; i < msg->outsize; i++)
82 csum += msg->data[i];
83
84 request->checksum = -csum;
85
86 return sizeof(*request) + msg->outsize;
87}
88
89static int prepare_tx_legacy(struct cros_ec_device *ec_dev,
90 struct cros_ec_command *msg)
91{
92 u8 *out;
93 u8 csum;
94 int i;
95
96 if (msg->outsize > EC_PROTO2_MAX_PARAM_SIZE)
97 return -EINVAL;
98
99 out = ec_dev->dout;
100 out[0] = EC_CMD_VERSION0 + msg->version;
101 out[1] = msg->command;
102 out[2] = msg->outsize;
103 csum = out[0] + out[1] + out[2];
104 for (i = 0; i < msg->outsize; i++)
105 csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->data[i];
106 out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = csum;
107
108 return EC_MSG_TX_PROTO_BYTES + msg->outsize;
109}
110
111static int cros_ec_xfer_command(struct cros_ec_device *ec_dev, struct cros_ec_command *msg)
112{
113 int ret;
114 int (*xfer_fxn)(struct cros_ec_device *ec, struct cros_ec_command *msg);
115
116 if (ec_dev->proto_version > 2)
117 xfer_fxn = ec_dev->pkt_xfer;
118 else
119 xfer_fxn = ec_dev->cmd_xfer;
120
121 if (!xfer_fxn) {
122 /*
123 * This error can happen if a communication error happened and
124 * the EC is trying to use protocol v2, on an underlying
125 * communication mechanism that does not support v2.
126 */
127 dev_err_once(ec_dev->dev, "missing EC transfer API, cannot send command\n");
128 return -EIO;
129 }
130
131 trace_cros_ec_request_start(msg);
132 ret = (*xfer_fxn)(ec_dev, msg);
133 trace_cros_ec_request_done(msg, ret);
134
135 return ret;
136}
137
138static int cros_ec_wait_until_complete(struct cros_ec_device *ec_dev, uint32_t *result)
139{
140 struct {
141 struct cros_ec_command msg;
142 struct ec_response_get_comms_status status;
143 } __packed buf;
144 struct cros_ec_command *msg = &buf.msg;
145 struct ec_response_get_comms_status *status = &buf.status;
146 int ret = 0, i;
147
148 msg->version = 0;
149 msg->command = EC_CMD_GET_COMMS_STATUS;
150 msg->insize = sizeof(*status);
151 msg->outsize = 0;
152
153 /* Query the EC's status until it's no longer busy or we encounter an error. */
154 for (i = 0; i < EC_COMMAND_RETRIES; ++i) {
155 usleep_range(10000, 11000);
156
157 ret = cros_ec_xfer_command(ec_dev, msg);
158 if (ret == -EAGAIN)
159 continue;
160 if (ret < 0)
161 return ret;
162
163 *result = msg->result;
164 if (msg->result != EC_RES_SUCCESS)
165 return ret;
166
167 if (ret == 0) {
168 ret = -EPROTO;
169 break;
170 }
171
172 if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
173 return ret;
174 }
175
176 if (i >= EC_COMMAND_RETRIES)
177 ret = -EAGAIN;
178
179 return ret;
180}
181
182static int cros_ec_send_command(struct cros_ec_device *ec_dev, struct cros_ec_command *msg)
183{
184 int ret = cros_ec_xfer_command(ec_dev, msg);
185
186 if (msg->result == EC_RES_IN_PROGRESS)
187 ret = cros_ec_wait_until_complete(ec_dev, &msg->result);
188
189 return ret;
190}
191
192/**
193 * cros_ec_prepare_tx() - Prepare an outgoing message in the output buffer.
194 * @ec_dev: Device to register.
195 * @msg: Message to write.
196 *
197 * This is used by all ChromeOS EC drivers to prepare the outgoing message
198 * according to different protocol versions.
199 *
200 * Return: number of prepared bytes on success or negative error code.
201 */
202int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
203 struct cros_ec_command *msg)
204{
205 if (ec_dev->proto_version > 2)
206 return prepare_tx(ec_dev, msg);
207
208 return prepare_tx_legacy(ec_dev, msg);
209}
210EXPORT_SYMBOL(cros_ec_prepare_tx);
211
212/**
213 * cros_ec_check_result() - Check ec_msg->result.
214 * @ec_dev: EC device.
215 * @msg: Message to check.
216 *
217 * This is used by ChromeOS EC drivers to check the ec_msg->result for
218 * EC_RES_IN_PROGRESS and to warn about them.
219 *
220 * The function should not check for furthermore error codes. Otherwise,
221 * it would break the ABI.
222 *
223 * Return: -EAGAIN if ec_msg->result == EC_RES_IN_PROGRESS. Otherwise, 0.
224 */
225int cros_ec_check_result(struct cros_ec_device *ec_dev,
226 struct cros_ec_command *msg)
227{
228 switch (msg->result) {
229 case EC_RES_SUCCESS:
230 return 0;
231 case EC_RES_IN_PROGRESS:
232 dev_dbg(ec_dev->dev, "command 0x%02x in progress\n",
233 msg->command);
234 return -EAGAIN;
235 default:
236 dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n",
237 msg->command, msg->result);
238 return 0;
239 }
240}
241EXPORT_SYMBOL(cros_ec_check_result);
242
243/**
244 * cros_ec_get_host_event_wake_mask
245 *
246 * Get the mask of host events that cause wake from suspend.
247 *
248 * @ec_dev: EC device to call
249 * @mask: result when function returns 0.
250 *
251 * LOCKING:
252 * the caller has ec_dev->lock mutex, or the caller knows there is
253 * no other command in progress.
254 */
255static int cros_ec_get_host_event_wake_mask(struct cros_ec_device *ec_dev, uint32_t *mask)
256{
257 struct cros_ec_command *msg;
258 struct ec_response_host_event_mask *r;
259 int ret, mapped;
260
261 msg = kzalloc(sizeof(*msg) + sizeof(*r), GFP_KERNEL);
262 if (!msg)
263 return -ENOMEM;
264
265 msg->command = EC_CMD_HOST_EVENT_GET_WAKE_MASK;
266 msg->insize = sizeof(*r);
267
268 ret = cros_ec_send_command(ec_dev, msg);
269 if (ret < 0)
270 goto exit;
271
272 mapped = cros_ec_map_error(msg->result);
273 if (mapped) {
274 ret = mapped;
275 goto exit;
276 }
277
278 if (ret == 0) {
279 ret = -EPROTO;
280 goto exit;
281 }
282
283 r = (struct ec_response_host_event_mask *)msg->data;
284 *mask = r->mask;
285 ret = 0;
286exit:
287 kfree(msg);
288 return ret;
289}
290
291static int cros_ec_get_proto_info(struct cros_ec_device *ec_dev, int devidx)
292{
293 struct cros_ec_command *msg;
294 struct ec_response_get_protocol_info *info;
295 int ret, mapped;
296
297 ec_dev->proto_version = 3;
298 if (devidx > 0)
299 ec_dev->max_passthru = 0;
300
301 msg = kzalloc(sizeof(*msg) + sizeof(*info), GFP_KERNEL);
302 if (!msg)
303 return -ENOMEM;
304
305 msg->command = EC_CMD_PASSTHRU_OFFSET(devidx) | EC_CMD_GET_PROTOCOL_INFO;
306 msg->insize = sizeof(*info);
307
308 ret = cros_ec_send_command(ec_dev, msg);
309 /*
310 * Send command once again when timeout occurred.
311 * Fingerprint MCU (FPMCU) is restarted during system boot which
312 * introduces small window in which FPMCU won't respond for any
313 * messages sent by kernel. There is no need to wait before next
314 * attempt because we waited at least EC_MSG_DEADLINE_MS.
315 */
316 if (ret == -ETIMEDOUT)
317 ret = cros_ec_send_command(ec_dev, msg);
318
319 if (ret < 0) {
320 dev_dbg(ec_dev->dev,
321 "failed to check for EC[%d] protocol version: %d\n",
322 devidx, ret);
323 goto exit;
324 }
325
326 mapped = cros_ec_map_error(msg->result);
327 if (mapped) {
328 ret = mapped;
329 goto exit;
330 }
331
332 if (ret == 0) {
333 ret = -EPROTO;
334 goto exit;
335 }
336
337 info = (struct ec_response_get_protocol_info *)msg->data;
338
339 switch (devidx) {
340 case CROS_EC_DEV_EC_INDEX:
341 ec_dev->max_request = info->max_request_packet_size -
342 sizeof(struct ec_host_request);
343 ec_dev->max_response = info->max_response_packet_size -
344 sizeof(struct ec_host_response);
345 ec_dev->proto_version = min(EC_HOST_REQUEST_VERSION,
346 fls(info->protocol_versions) - 1);
347 ec_dev->din_size = info->max_response_packet_size + EC_MAX_RESPONSE_OVERHEAD;
348 ec_dev->dout_size = info->max_request_packet_size + EC_MAX_REQUEST_OVERHEAD;
349
350 dev_dbg(ec_dev->dev, "using proto v%u\n", ec_dev->proto_version);
351 break;
352 case CROS_EC_DEV_PD_INDEX:
353 ec_dev->max_passthru = info->max_request_packet_size -
354 sizeof(struct ec_host_request);
355
356 dev_dbg(ec_dev->dev, "found PD chip\n");
357 break;
358 default:
359 dev_dbg(ec_dev->dev, "unknown passthru index: %d\n", devidx);
360 break;
361 }
362
363 ret = 0;
364exit:
365 kfree(msg);
366 return ret;
367}
368
369static int cros_ec_get_proto_info_legacy(struct cros_ec_device *ec_dev)
370{
371 struct cros_ec_command *msg;
372 struct ec_params_hello *params;
373 struct ec_response_hello *response;
374 int ret, mapped;
375
376 ec_dev->proto_version = 2;
377
378 msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*response)), GFP_KERNEL);
379 if (!msg)
380 return -ENOMEM;
381
382 msg->command = EC_CMD_HELLO;
383 msg->insize = sizeof(*response);
384 msg->outsize = sizeof(*params);
385
386 params = (struct ec_params_hello *)msg->data;
387 params->in_data = 0xa0b0c0d0;
388
389 ret = cros_ec_send_command(ec_dev, msg);
390 if (ret < 0) {
391 dev_dbg(ec_dev->dev, "EC failed to respond to v2 hello: %d\n", ret);
392 goto exit;
393 }
394
395 mapped = cros_ec_map_error(msg->result);
396 if (mapped) {
397 ret = mapped;
398 dev_err(ec_dev->dev, "EC responded to v2 hello with error: %d\n", msg->result);
399 goto exit;
400 }
401
402 if (ret == 0) {
403 ret = -EPROTO;
404 goto exit;
405 }
406
407 response = (struct ec_response_hello *)msg->data;
408 if (response->out_data != 0xa1b2c3d4) {
409 dev_err(ec_dev->dev,
410 "EC responded to v2 hello with bad result: %u\n",
411 response->out_data);
412 ret = -EBADMSG;
413 goto exit;
414 }
415
416 ec_dev->max_request = EC_PROTO2_MAX_PARAM_SIZE;
417 ec_dev->max_response = EC_PROTO2_MAX_PARAM_SIZE;
418 ec_dev->max_passthru = 0;
419 ec_dev->pkt_xfer = NULL;
420 ec_dev->din_size = EC_PROTO2_MSG_BYTES;
421 ec_dev->dout_size = EC_PROTO2_MSG_BYTES;
422
423 dev_dbg(ec_dev->dev, "falling back to proto v2\n");
424 ret = 0;
425exit:
426 kfree(msg);
427 return ret;
428}
429
430/**
431 * cros_ec_get_host_command_version_mask
432 *
433 * Get the version mask of a given command.
434 *
435 * @ec_dev: EC device to call
436 * @cmd: command to get the version of.
437 * @mask: result when function returns 0.
438 *
439 * @return 0 on success, error code otherwise
440 *
441 * LOCKING:
442 * the caller has ec_dev->lock mutex or the caller knows there is
443 * no other command in progress.
444 */
445static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev, u16 cmd, u32 *mask)
446{
447 struct ec_params_get_cmd_versions *pver;
448 struct ec_response_get_cmd_versions *rver;
449 struct cros_ec_command *msg;
450 int ret, mapped;
451
452 msg = kmalloc(sizeof(*msg) + max(sizeof(*rver), sizeof(*pver)),
453 GFP_KERNEL);
454 if (!msg)
455 return -ENOMEM;
456
457 msg->version = 0;
458 msg->command = EC_CMD_GET_CMD_VERSIONS;
459 msg->insize = sizeof(*rver);
460 msg->outsize = sizeof(*pver);
461
462 pver = (struct ec_params_get_cmd_versions *)msg->data;
463 pver->cmd = cmd;
464
465 ret = cros_ec_send_command(ec_dev, msg);
466 if (ret < 0)
467 goto exit;
468
469 mapped = cros_ec_map_error(msg->result);
470 if (mapped) {
471 ret = mapped;
472 goto exit;
473 }
474
475 if (ret == 0) {
476 ret = -EPROTO;
477 goto exit;
478 }
479
480 rver = (struct ec_response_get_cmd_versions *)msg->data;
481 *mask = rver->version_mask;
482 ret = 0;
483exit:
484 kfree(msg);
485 return ret;
486}
487
488/**
489 * cros_ec_query_all() - Query the protocol version supported by the
490 * ChromeOS EC.
491 * @ec_dev: Device to register.
492 *
493 * Return: 0 on success or negative error code.
494 */
495int cros_ec_query_all(struct cros_ec_device *ec_dev)
496{
497 struct device *dev = ec_dev->dev;
498 u32 ver_mask;
499 int ret;
500
501 /* First try sending with proto v3. */
502 if (!cros_ec_get_proto_info(ec_dev, CROS_EC_DEV_EC_INDEX)) {
503 /* Check for PD. */
504 cros_ec_get_proto_info(ec_dev, CROS_EC_DEV_PD_INDEX);
505 } else {
506 /* Try querying with a v2 hello message. */
507 ret = cros_ec_get_proto_info_legacy(ec_dev);
508 if (ret) {
509 /*
510 * It's possible for a test to occur too early when
511 * the EC isn't listening. If this happens, we'll
512 * test later when the first command is run.
513 */
514 ec_dev->proto_version = EC_PROTO_VERSION_UNKNOWN;
515 dev_dbg(ec_dev->dev, "EC query failed: %d\n", ret);
516 return ret;
517 }
518 }
519
520 devm_kfree(dev, ec_dev->din);
521 devm_kfree(dev, ec_dev->dout);
522
523 ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
524 if (!ec_dev->din) {
525 ret = -ENOMEM;
526 goto exit;
527 }
528
529 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
530 if (!ec_dev->dout) {
531 devm_kfree(dev, ec_dev->din);
532 ret = -ENOMEM;
533 goto exit;
534 }
535
536 /* Probe if MKBP event is supported */
537 ret = cros_ec_get_host_command_version_mask(ec_dev, EC_CMD_GET_NEXT_EVENT, &ver_mask);
538 if (ret < 0 || ver_mask == 0) {
539 ec_dev->mkbp_event_supported = 0;
540 } else {
541 ec_dev->mkbp_event_supported = fls(ver_mask);
542
543 dev_dbg(ec_dev->dev, "MKBP support version %u\n", ec_dev->mkbp_event_supported - 1);
544 }
545
546 /* Probe if host sleep v1 is supported for S0ix failure detection. */
547 ret = cros_ec_get_host_command_version_mask(ec_dev, EC_CMD_HOST_SLEEP_EVENT, &ver_mask);
548 ec_dev->host_sleep_v1 = (ret == 0 && (ver_mask & EC_VER_MASK(1)));
549
550 /* Get host event wake mask. */
551 ret = cros_ec_get_host_event_wake_mask(ec_dev, &ec_dev->host_event_wake_mask);
552 if (ret < 0) {
553 /*
554 * If the EC doesn't support EC_CMD_HOST_EVENT_GET_WAKE_MASK,
555 * use a reasonable default. Note that we ignore various
556 * battery, AC status, and power-state events, because (a)
557 * those can be quite common (e.g., when sitting at full
558 * charge, on AC) and (b) these are not actionable wake events;
559 * if anything, we'd like to continue suspending (to save
560 * power), not wake up.
561 */
562 ec_dev->host_event_wake_mask = U32_MAX &
563 ~(EC_HOST_EVENT_MASK(EC_HOST_EVENT_LID_CLOSED) |
564 EC_HOST_EVENT_MASK(EC_HOST_EVENT_AC_DISCONNECTED) |
565 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_LOW) |
566 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_CRITICAL) |
567 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY) |
568 EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
569 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_STATUS));
570 /*
571 * Old ECs may not support this command. Complain about all
572 * other errors.
573 */
574 if (ret != -EOPNOTSUPP)
575 dev_err(ec_dev->dev,
576 "failed to retrieve wake mask: %d\n", ret);
577 }
578
579 ret = 0;
580
581exit:
582 return ret;
583}
584EXPORT_SYMBOL(cros_ec_query_all);
585
586/**
587 * cros_ec_cmd_xfer() - Send a command to the ChromeOS EC.
588 * @ec_dev: EC device.
589 * @msg: Message to write.
590 *
591 * Call this to send a command to the ChromeOS EC. This should be used instead
592 * of calling the EC's cmd_xfer() callback directly. This function does not
593 * convert EC command execution error codes to Linux error codes. Most
594 * in-kernel users will want to use cros_ec_cmd_xfer_status() instead since
595 * that function implements the conversion.
596 *
597 * Return:
598 * >0 - EC command was executed successfully. The return value is the number
599 * of bytes returned by the EC (excluding the header).
600 * =0 - EC communication was successful. EC command execution results are
601 * reported in msg->result. The result will be EC_RES_SUCCESS if the
602 * command was executed successfully or report an EC command execution
603 * error.
604 * <0 - EC communication error. Return value is the Linux error code.
605 */
606int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev, struct cros_ec_command *msg)
607{
608 int ret;
609
610 mutex_lock(&ec_dev->lock);
611 if (ec_dev->proto_version == EC_PROTO_VERSION_UNKNOWN) {
612 ret = cros_ec_query_all(ec_dev);
613 if (ret) {
614 dev_err(ec_dev->dev,
615 "EC version unknown and query failed; aborting command\n");
616 mutex_unlock(&ec_dev->lock);
617 return ret;
618 }
619 }
620
621 if (msg->insize > ec_dev->max_response) {
622 dev_dbg(ec_dev->dev, "clamping message receive buffer\n");
623 msg->insize = ec_dev->max_response;
624 }
625
626 if (msg->command < EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX)) {
627 if (msg->outsize > ec_dev->max_request) {
628 dev_err(ec_dev->dev,
629 "request of size %u is too big (max: %u)\n",
630 msg->outsize,
631 ec_dev->max_request);
632 mutex_unlock(&ec_dev->lock);
633 return -EMSGSIZE;
634 }
635 } else {
636 if (msg->outsize > ec_dev->max_passthru) {
637 dev_err(ec_dev->dev,
638 "passthru rq of size %u is too big (max: %u)\n",
639 msg->outsize,
640 ec_dev->max_passthru);
641 mutex_unlock(&ec_dev->lock);
642 return -EMSGSIZE;
643 }
644 }
645
646 ret = cros_ec_send_command(ec_dev, msg);
647 mutex_unlock(&ec_dev->lock);
648
649 return ret;
650}
651EXPORT_SYMBOL(cros_ec_cmd_xfer);
652
653/**
654 * cros_ec_cmd_xfer_status() - Send a command to the ChromeOS EC.
655 * @ec_dev: EC device.
656 * @msg: Message to write.
657 *
658 * Call this to send a command to the ChromeOS EC. This should be used instead of calling the EC's
659 * cmd_xfer() callback directly. It returns success status only if both the command was transmitted
660 * successfully and the EC replied with success status.
661 *
662 * Return:
663 * >=0 - The number of bytes transferred.
664 * <0 - Linux error code
665 */
666int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
667 struct cros_ec_command *msg)
668{
669 int ret, mapped;
670
671 ret = cros_ec_cmd_xfer(ec_dev, msg);
672 if (ret < 0)
673 return ret;
674
675 mapped = cros_ec_map_error(msg->result);
676 if (mapped) {
677 dev_dbg(ec_dev->dev, "Command result (err: %d [%d])\n",
678 msg->result, mapped);
679 ret = mapped;
680 }
681
682 return ret;
683}
684EXPORT_SYMBOL(cros_ec_cmd_xfer_status);
685
686static int get_next_event_xfer(struct cros_ec_device *ec_dev,
687 struct cros_ec_command *msg,
688 struct ec_response_get_next_event_v3 *event,
689 int version, uint32_t size)
690{
691 int ret;
692
693 msg->version = version;
694 msg->command = EC_CMD_GET_NEXT_EVENT;
695 msg->insize = size;
696 msg->outsize = 0;
697
698 ret = cros_ec_cmd_xfer_status(ec_dev, msg);
699 if (ret > 0) {
700 ec_dev->event_size = ret - 1;
701 ec_dev->event_data = *event;
702 }
703
704 return ret;
705}
706
707static int get_next_event(struct cros_ec_device *ec_dev)
708{
709 struct {
710 struct cros_ec_command msg;
711 struct ec_response_get_next_event_v3 event;
712 } __packed buf;
713 struct cros_ec_command *msg = &buf.msg;
714 struct ec_response_get_next_event_v3 *event = &buf.event;
715 int cmd_version = ec_dev->mkbp_event_supported - 1;
716 u32 size;
717
718 memset(msg, 0, sizeof(*msg));
719 if (ec_dev->suspended) {
720 dev_dbg(ec_dev->dev, "Device suspended.\n");
721 return -EHOSTDOWN;
722 }
723
724 if (cmd_version == 0) {
725 size = sizeof(struct ec_response_get_next_event);
726 } else if (cmd_version < 3) {
727 size = sizeof(struct ec_response_get_next_event_v1);
728 } else {
729 /*
730 * The max version we support is v3. So, we speak v3 even if the
731 * EC says it supports v4+.
732 */
733 cmd_version = 3;
734 size = sizeof(struct ec_response_get_next_event_v3);
735 }
736
737 return get_next_event_xfer(ec_dev, msg, event, cmd_version, size);
738}
739
740static int get_keyboard_state_event(struct cros_ec_device *ec_dev)
741{
742 u8 buffer[sizeof(struct cros_ec_command) +
743 sizeof(ec_dev->event_data.data)];
744 struct cros_ec_command *msg = (struct cros_ec_command *)&buffer;
745
746 msg->version = 0;
747 msg->command = EC_CMD_MKBP_STATE;
748 msg->insize = sizeof(ec_dev->event_data.data);
749 msg->outsize = 0;
750
751 ec_dev->event_size = cros_ec_cmd_xfer_status(ec_dev, msg);
752 ec_dev->event_data.event_type = EC_MKBP_EVENT_KEY_MATRIX;
753 memcpy(&ec_dev->event_data.data, msg->data,
754 sizeof(ec_dev->event_data.data));
755
756 return ec_dev->event_size;
757}
758
759/**
760 * cros_ec_get_next_event() - Fetch next event from the ChromeOS EC.
761 * @ec_dev: Device to fetch event from.
762 * @wake_event: Pointer to a bool set to true upon return if the event might be
763 * treated as a wake event. Ignored if null.
764 * @has_more_events: Pointer to bool set to true if more than one event is
765 * pending.
766 * Some EC will set this flag to indicate cros_ec_get_next_event()
767 * can be called multiple times in a row.
768 * It is an optimization to prevent issuing a EC command for
769 * nothing or wait for another interrupt from the EC to process
770 * the next message.
771 * Ignored if null.
772 *
773 * Return: negative error code on errors; 0 for no data; or else number of
774 * bytes received (i.e., an event was retrieved successfully). Event types are
775 * written out to @ec_dev->event_data.event_type on success.
776 */
777int cros_ec_get_next_event(struct cros_ec_device *ec_dev,
778 bool *wake_event,
779 bool *has_more_events)
780{
781 u8 event_type;
782 u32 host_event;
783 int ret;
784 u32 ver_mask;
785
786 /*
787 * Default value for wake_event.
788 * Wake up on keyboard event, wake up for spurious interrupt or link
789 * error to the EC.
790 */
791 if (wake_event)
792 *wake_event = true;
793
794 /*
795 * Default value for has_more_events.
796 * EC will raise another interrupt if AP does not process all events
797 * anyway.
798 */
799 if (has_more_events)
800 *has_more_events = false;
801
802 if (!ec_dev->mkbp_event_supported)
803 return get_keyboard_state_event(ec_dev);
804
805 ret = get_next_event(ec_dev);
806 /*
807 * -ENOPROTOOPT is returned when EC returns EC_RES_INVALID_VERSION.
808 * This can occur when EC based device (e.g. Fingerprint MCU) jumps to
809 * the RO image which doesn't support newer version of the command. In
810 * this case we will attempt to update maximum supported version of the
811 * EC_CMD_GET_NEXT_EVENT.
812 */
813 if (ret == -ENOPROTOOPT) {
814 dev_dbg(ec_dev->dev,
815 "GET_NEXT_EVENT returned invalid version error.\n");
816 mutex_lock(&ec_dev->lock);
817 ret = cros_ec_get_host_command_version_mask(ec_dev,
818 EC_CMD_GET_NEXT_EVENT,
819 &ver_mask);
820 mutex_unlock(&ec_dev->lock);
821 if (ret < 0 || ver_mask == 0)
822 /*
823 * Do not change the MKBP supported version if we can't
824 * obtain supported version correctly. Please note that
825 * calling EC_CMD_GET_NEXT_EVENT returned
826 * EC_RES_INVALID_VERSION which means that the command
827 * is present.
828 */
829 return -ENOPROTOOPT;
830
831 ec_dev->mkbp_event_supported = fls(ver_mask);
832 dev_dbg(ec_dev->dev, "MKBP support version changed to %u\n",
833 ec_dev->mkbp_event_supported - 1);
834
835 /* Try to get next event with new MKBP support version set. */
836 ret = get_next_event(ec_dev);
837 }
838
839 if (ret <= 0)
840 return ret;
841
842 if (has_more_events)
843 *has_more_events = ec_dev->event_data.event_type &
844 EC_MKBP_HAS_MORE_EVENTS;
845 ec_dev->event_data.event_type &= EC_MKBP_EVENT_TYPE_MASK;
846
847 if (wake_event) {
848 event_type = ec_dev->event_data.event_type;
849 host_event = cros_ec_get_host_event(ec_dev);
850
851 /*
852 * Sensor events need to be parsed by the sensor sub-device.
853 * Defer them, and don't report the wakeup here.
854 */
855 if (event_type == EC_MKBP_EVENT_SENSOR_FIFO) {
856 *wake_event = false;
857 } else if (host_event) {
858 /* rtc_update_irq() already handles wakeup events. */
859 if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_RTC))
860 *wake_event = false;
861 /* Masked host-events should not count as wake events. */
862 if (!(host_event & ec_dev->host_event_wake_mask))
863 *wake_event = false;
864 }
865 }
866
867 return ret;
868}
869EXPORT_SYMBOL(cros_ec_get_next_event);
870
871/**
872 * cros_ec_get_host_event() - Return a mask of event set by the ChromeOS EC.
873 * @ec_dev: Device to fetch event from.
874 *
875 * When MKBP is supported, when the EC raises an interrupt, we collect the
876 * events raised and call the functions in the ec notifier. This function
877 * is a helper to know which events are raised.
878 *
879 * Return: 0 on error or non-zero bitmask of one or more EC_HOST_EVENT_*.
880 */
881u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev)
882{
883 u32 host_event;
884
885 if (!ec_dev->mkbp_event_supported)
886 return 0;
887
888 if (ec_dev->event_data.event_type != EC_MKBP_EVENT_HOST_EVENT)
889 return 0;
890
891 if (ec_dev->event_size != sizeof(host_event)) {
892 dev_warn(ec_dev->dev, "Invalid host event size\n");
893 return 0;
894 }
895
896 host_event = get_unaligned_le32(&ec_dev->event_data.data.host_event);
897
898 return host_event;
899}
900EXPORT_SYMBOL(cros_ec_get_host_event);
901
902/**
903 * cros_ec_check_features() - Test for the presence of EC features
904 *
905 * @ec: EC device, does not have to be connected directly to the AP,
906 * can be daisy chained through another device.
907 * @feature: One of ec_feature_code bit.
908 *
909 * Call this function to test whether the ChromeOS EC supports a feature.
910 *
911 * Return: true if supported, false if not (or if an error was encountered).
912 */
913bool cros_ec_check_features(struct cros_ec_dev *ec, int feature)
914{
915 struct ec_response_get_features *features = &ec->features;
916 int ret;
917
918 if (features->flags[0] == -1U && features->flags[1] == -1U) {
919 /* features bitmap not read yet */
920 ret = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_GET_FEATURES + ec->cmd_offset,
921 NULL, 0, features, sizeof(*features));
922 if (ret < 0) {
923 dev_warn(ec->dev, "cannot get EC features: %d\n", ret);
924 memset(features, 0, sizeof(*features));
925 }
926
927 dev_dbg(ec->dev, "EC features %08x %08x\n",
928 features->flags[0], features->flags[1]);
929 }
930
931 return !!(features->flags[feature / 32] & EC_FEATURE_MASK_0(feature));
932}
933EXPORT_SYMBOL_GPL(cros_ec_check_features);
934
935/**
936 * cros_ec_get_sensor_count() - Return the number of MEMS sensors supported.
937 *
938 * @ec: EC device, does not have to be connected directly to the AP,
939 * can be daisy chained through another device.
940 * Return: < 0 in case of error.
941 */
942int cros_ec_get_sensor_count(struct cros_ec_dev *ec)
943{
944 /*
945 * Issue a command to get the number of sensor reported.
946 * If not supported, check for legacy mode.
947 */
948 int ret, sensor_count;
949 struct ec_params_motion_sense *params;
950 struct ec_response_motion_sense *resp;
951 struct cros_ec_command *msg;
952 struct cros_ec_device *ec_dev = ec->ec_dev;
953 u8 status;
954
955 msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*resp)),
956 GFP_KERNEL);
957 if (!msg)
958 return -ENOMEM;
959
960 msg->version = 1;
961 msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
962 msg->outsize = sizeof(*params);
963 msg->insize = sizeof(*resp);
964
965 params = (struct ec_params_motion_sense *)msg->data;
966 params->cmd = MOTIONSENSE_CMD_DUMP;
967
968 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
969 if (ret < 0) {
970 sensor_count = ret;
971 } else {
972 resp = (struct ec_response_motion_sense *)msg->data;
973 sensor_count = resp->dump.sensor_count;
974 }
975 kfree(msg);
976
977 /*
978 * Check legacy mode: Let's find out if sensors are accessible
979 * via LPC interface.
980 */
981 if (sensor_count < 0 && ec->cmd_offset == 0 && ec_dev->cmd_readmem) {
982 ret = ec_dev->cmd_readmem(ec_dev, EC_MEMMAP_ACC_STATUS,
983 1, &status);
984 if (ret >= 0 &&
985 (status & EC_MEMMAP_ACC_STATUS_PRESENCE_BIT)) {
986 /*
987 * We have 2 sensors, one in the lid, one in the base.
988 */
989 sensor_count = 2;
990 } else {
991 /*
992 * EC uses LPC interface and no sensors are presented.
993 */
994 sensor_count = 0;
995 }
996 }
997 return sensor_count;
998}
999EXPORT_SYMBOL_GPL(cros_ec_get_sensor_count);
1000
1001/**
1002 * cros_ec_cmd - Send a command to the EC.
1003 *
1004 * @ec_dev: EC device
1005 * @version: EC command version
1006 * @command: EC command
1007 * @outdata: EC command output data
1008 * @outsize: Size of outdata
1009 * @indata: EC command input data
1010 * @insize: Size of indata
1011 *
1012 * Return: >= 0 on success, negative error number on failure.
1013 */
1014int cros_ec_cmd(struct cros_ec_device *ec_dev,
1015 unsigned int version,
1016 int command,
1017 const void *outdata,
1018 size_t outsize,
1019 void *indata,
1020 size_t insize)
1021{
1022 struct cros_ec_command *msg;
1023 int ret;
1024
1025 msg = kzalloc(sizeof(*msg) + max(insize, outsize), GFP_KERNEL);
1026 if (!msg)
1027 return -ENOMEM;
1028
1029 msg->version = version;
1030 msg->command = command;
1031 msg->outsize = outsize;
1032 msg->insize = insize;
1033
1034 if (outsize)
1035 memcpy(msg->data, outdata, outsize);
1036
1037 ret = cros_ec_cmd_xfer_status(ec_dev, msg);
1038 if (ret < 0)
1039 goto error;
1040
1041 if (insize)
1042 memcpy(indata, msg->data, insize);
1043error:
1044 kfree(msg);
1045 return ret;
1046}
1047EXPORT_SYMBOL_GPL(cros_ec_cmd);
1048
1049/**
1050 * cros_ec_cmd_readmem - Read from EC memory.
1051 *
1052 * @ec_dev: EC device
1053 * @offset: Is within EC_LPC_ADDR_MEMMAP region.
1054 * @size: Number of bytes to read.
1055 * @dest: EC command output data
1056 *
1057 * Return: >= 0 on success, negative error number on failure.
1058 */
1059int cros_ec_cmd_readmem(struct cros_ec_device *ec_dev, u8 offset, u8 size, void *dest)
1060{
1061 struct ec_params_read_memmap params = {};
1062
1063 if (!size)
1064 return -EINVAL;
1065
1066 if (ec_dev->cmd_readmem)
1067 return ec_dev->cmd_readmem(ec_dev, offset, size, dest);
1068
1069 params.offset = offset;
1070 params.size = size;
1071 return cros_ec_cmd(ec_dev, 0, EC_CMD_READ_MEMMAP,
1072 ¶ms, sizeof(params), dest, size);
1073}
1074EXPORT_SYMBOL_GPL(cros_ec_cmd_readmem);
1075
1076/**
1077 * cros_ec_get_cmd_versions - Get supported version mask.
1078 *
1079 * @ec_dev: EC device
1080 * @cmd: Command to test
1081 *
1082 * Return: version mask on success, negative error number on failure.
1083 */
1084int cros_ec_get_cmd_versions(struct cros_ec_device *ec_dev, u16 cmd)
1085{
1086 struct ec_params_get_cmd_versions req_v0;
1087 struct ec_params_get_cmd_versions_v1 req_v1;
1088 struct ec_response_get_cmd_versions resp;
1089 int ret;
1090
1091 if (cmd <= U8_MAX) {
1092 req_v0.cmd = cmd;
1093 ret = cros_ec_cmd(ec_dev, 0, EC_CMD_GET_CMD_VERSIONS,
1094 &req_v0, sizeof(req_v0), &resp, sizeof(resp));
1095 } else {
1096 req_v1.cmd = cmd;
1097 ret = cros_ec_cmd(ec_dev, 1, EC_CMD_GET_CMD_VERSIONS,
1098 &req_v1, sizeof(req_v1), &resp, sizeof(resp));
1099 }
1100
1101 if (ret == -EINVAL)
1102 return 0; /* Command not implemented */
1103 else if (ret < 0)
1104 return ret;
1105 else
1106 return resp.version_mask;
1107}
1108EXPORT_SYMBOL_GPL(cros_ec_get_cmd_versions);
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
18static 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
41static 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
55static int prepare_tx(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 if (msg->outsize + sizeof(*request) > ec_dev->dout_size)
64 return -EINVAL;
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
88static int prepare_tx_legacy(struct cros_ec_device *ec_dev,
89 struct cros_ec_command *msg)
90{
91 u8 *out;
92 u8 csum;
93 int i;
94
95 if (msg->outsize > EC_PROTO2_MAX_PARAM_SIZE)
96 return -EINVAL;
97
98 out = ec_dev->dout;
99 out[0] = EC_CMD_VERSION0 + msg->version;
100 out[1] = msg->command;
101 out[2] = msg->outsize;
102 csum = out[0] + out[1] + out[2];
103 for (i = 0; i < msg->outsize; i++)
104 csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->data[i];
105 out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = csum;
106
107 return EC_MSG_TX_PROTO_BYTES + msg->outsize;
108}
109
110static int cros_ec_xfer_command(struct cros_ec_device *ec_dev, struct cros_ec_command *msg)
111{
112 int ret;
113 int (*xfer_fxn)(struct cros_ec_device *ec, struct cros_ec_command *msg);
114
115 if (ec_dev->proto_version > 2)
116 xfer_fxn = ec_dev->pkt_xfer;
117 else
118 xfer_fxn = ec_dev->cmd_xfer;
119
120 if (!xfer_fxn) {
121 /*
122 * This error can happen if a communication error happened and
123 * the EC is trying to use protocol v2, on an underlying
124 * communication mechanism that does not support v2.
125 */
126 dev_err_once(ec_dev->dev, "missing EC transfer API, cannot send command\n");
127 return -EIO;
128 }
129
130 trace_cros_ec_request_start(msg);
131 ret = (*xfer_fxn)(ec_dev, msg);
132 trace_cros_ec_request_done(msg, ret);
133
134 return ret;
135}
136
137static int cros_ec_wait_until_complete(struct cros_ec_device *ec_dev, uint32_t *result)
138{
139 struct {
140 struct cros_ec_command msg;
141 struct ec_response_get_comms_status status;
142 } __packed buf;
143 struct cros_ec_command *msg = &buf.msg;
144 struct ec_response_get_comms_status *status = &buf.status;
145 int ret = 0, i;
146
147 msg->version = 0;
148 msg->command = EC_CMD_GET_COMMS_STATUS;
149 msg->insize = sizeof(*status);
150 msg->outsize = 0;
151
152 /* Query the EC's status until it's no longer busy or we encounter an error. */
153 for (i = 0; i < EC_COMMAND_RETRIES; ++i) {
154 usleep_range(10000, 11000);
155
156 ret = cros_ec_xfer_command(ec_dev, msg);
157 if (ret == -EAGAIN)
158 continue;
159 if (ret < 0)
160 return ret;
161
162 *result = msg->result;
163 if (msg->result != EC_RES_SUCCESS)
164 return ret;
165
166 if (ret == 0) {
167 ret = -EPROTO;
168 break;
169 }
170
171 if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
172 return ret;
173 }
174
175 if (i >= EC_COMMAND_RETRIES)
176 ret = -EAGAIN;
177
178 return ret;
179}
180
181static int cros_ec_send_command(struct cros_ec_device *ec_dev, struct cros_ec_command *msg)
182{
183 int ret = cros_ec_xfer_command(ec_dev, msg);
184
185 if (msg->result == EC_RES_IN_PROGRESS)
186 ret = cros_ec_wait_until_complete(ec_dev, &msg->result);
187
188 return ret;
189}
190
191/**
192 * cros_ec_prepare_tx() - Prepare an outgoing message in the output buffer.
193 * @ec_dev: Device to register.
194 * @msg: Message to write.
195 *
196 * This is used by all ChromeOS EC drivers to prepare the outgoing message
197 * according to different protocol versions.
198 *
199 * Return: number of prepared bytes on success or negative error code.
200 */
201int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
202 struct cros_ec_command *msg)
203{
204 if (ec_dev->proto_version > 2)
205 return prepare_tx(ec_dev, msg);
206
207 return prepare_tx_legacy(ec_dev, msg);
208}
209EXPORT_SYMBOL(cros_ec_prepare_tx);
210
211/**
212 * cros_ec_check_result() - Check ec_msg->result.
213 * @ec_dev: EC device.
214 * @msg: Message to check.
215 *
216 * This is used by ChromeOS EC drivers to check the ec_msg->result for
217 * EC_RES_IN_PROGRESS and to warn about them.
218 *
219 * The function should not check for furthermore error codes. Otherwise,
220 * it would break the ABI.
221 *
222 * Return: -EAGAIN if ec_msg->result == EC_RES_IN_PROGRESS. Otherwise, 0.
223 */
224int cros_ec_check_result(struct cros_ec_device *ec_dev,
225 struct cros_ec_command *msg)
226{
227 switch (msg->result) {
228 case EC_RES_SUCCESS:
229 return 0;
230 case EC_RES_IN_PROGRESS:
231 dev_dbg(ec_dev->dev, "command 0x%02x in progress\n",
232 msg->command);
233 return -EAGAIN;
234 default:
235 dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n",
236 msg->command, msg->result);
237 return 0;
238 }
239}
240EXPORT_SYMBOL(cros_ec_check_result);
241
242/*
243 * cros_ec_get_host_event_wake_mask
244 *
245 * Get the mask of host events that cause wake from suspend.
246 *
247 * @ec_dev: EC device to call
248 * @msg: message structure to use
249 * @mask: result when function returns 0.
250 *
251 * LOCKING:
252 * the caller has ec_dev->lock mutex, or the caller knows there is
253 * no other command in progress.
254 */
255static int cros_ec_get_host_event_wake_mask(struct cros_ec_device *ec_dev, uint32_t *mask)
256{
257 struct cros_ec_command *msg;
258 struct ec_response_host_event_mask *r;
259 int ret, mapped;
260
261 msg = kzalloc(sizeof(*msg) + sizeof(*r), GFP_KERNEL);
262 if (!msg)
263 return -ENOMEM;
264
265 msg->command = EC_CMD_HOST_EVENT_GET_WAKE_MASK;
266 msg->insize = sizeof(*r);
267
268 ret = cros_ec_send_command(ec_dev, msg);
269 if (ret < 0)
270 goto exit;
271
272 mapped = cros_ec_map_error(msg->result);
273 if (mapped) {
274 ret = mapped;
275 goto exit;
276 }
277
278 if (ret == 0) {
279 ret = -EPROTO;
280 goto exit;
281 }
282
283 r = (struct ec_response_host_event_mask *)msg->data;
284 *mask = r->mask;
285 ret = 0;
286exit:
287 kfree(msg);
288 return ret;
289}
290
291static int cros_ec_get_proto_info(struct cros_ec_device *ec_dev, int devidx)
292{
293 struct cros_ec_command *msg;
294 struct ec_response_get_protocol_info *info;
295 int ret, mapped;
296
297 ec_dev->proto_version = 3;
298 if (devidx > 0)
299 ec_dev->max_passthru = 0;
300
301 msg = kzalloc(sizeof(*msg) + sizeof(*info), GFP_KERNEL);
302 if (!msg)
303 return -ENOMEM;
304
305 msg->command = EC_CMD_PASSTHRU_OFFSET(devidx) | EC_CMD_GET_PROTOCOL_INFO;
306 msg->insize = sizeof(*info);
307
308 ret = cros_ec_send_command(ec_dev, msg);
309 /*
310 * Send command once again when timeout occurred.
311 * Fingerprint MCU (FPMCU) is restarted during system boot which
312 * introduces small window in which FPMCU won't respond for any
313 * messages sent by kernel. There is no need to wait before next
314 * attempt because we waited at least EC_MSG_DEADLINE_MS.
315 */
316 if (ret == -ETIMEDOUT)
317 ret = cros_ec_send_command(ec_dev, msg);
318
319 if (ret < 0) {
320 dev_dbg(ec_dev->dev,
321 "failed to check for EC[%d] protocol version: %d\n",
322 devidx, ret);
323 goto exit;
324 }
325
326 mapped = cros_ec_map_error(msg->result);
327 if (mapped) {
328 ret = mapped;
329 goto exit;
330 }
331
332 if (ret == 0) {
333 ret = -EPROTO;
334 goto exit;
335 }
336
337 info = (struct ec_response_get_protocol_info *)msg->data;
338
339 switch (devidx) {
340 case CROS_EC_DEV_EC_INDEX:
341 ec_dev->max_request = info->max_request_packet_size -
342 sizeof(struct ec_host_request);
343 ec_dev->max_response = info->max_response_packet_size -
344 sizeof(struct ec_host_response);
345 ec_dev->proto_version = min(EC_HOST_REQUEST_VERSION,
346 fls(info->protocol_versions) - 1);
347 ec_dev->din_size = info->max_response_packet_size + EC_MAX_RESPONSE_OVERHEAD;
348 ec_dev->dout_size = info->max_request_packet_size + EC_MAX_REQUEST_OVERHEAD;
349
350 dev_dbg(ec_dev->dev, "using proto v%u\n", ec_dev->proto_version);
351 break;
352 case CROS_EC_DEV_PD_INDEX:
353 ec_dev->max_passthru = info->max_request_packet_size -
354 sizeof(struct ec_host_request);
355
356 dev_dbg(ec_dev->dev, "found PD chip\n");
357 break;
358 default:
359 dev_dbg(ec_dev->dev, "unknown passthru index: %d\n", devidx);
360 break;
361 }
362
363 ret = 0;
364exit:
365 kfree(msg);
366 return ret;
367}
368
369static int cros_ec_get_proto_info_legacy(struct cros_ec_device *ec_dev)
370{
371 struct cros_ec_command *msg;
372 struct ec_params_hello *params;
373 struct ec_response_hello *response;
374 int ret, mapped;
375
376 ec_dev->proto_version = 2;
377
378 msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*response)), GFP_KERNEL);
379 if (!msg)
380 return -ENOMEM;
381
382 msg->command = EC_CMD_HELLO;
383 msg->insize = sizeof(*response);
384 msg->outsize = sizeof(*params);
385
386 params = (struct ec_params_hello *)msg->data;
387 params->in_data = 0xa0b0c0d0;
388
389 ret = cros_ec_send_command(ec_dev, msg);
390 if (ret < 0) {
391 dev_dbg(ec_dev->dev, "EC failed to respond to v2 hello: %d\n", ret);
392 goto exit;
393 }
394
395 mapped = cros_ec_map_error(msg->result);
396 if (mapped) {
397 ret = mapped;
398 dev_err(ec_dev->dev, "EC responded to v2 hello with error: %d\n", msg->result);
399 goto exit;
400 }
401
402 if (ret == 0) {
403 ret = -EPROTO;
404 goto exit;
405 }
406
407 response = (struct ec_response_hello *)msg->data;
408 if (response->out_data != 0xa1b2c3d4) {
409 dev_err(ec_dev->dev,
410 "EC responded to v2 hello with bad result: %u\n",
411 response->out_data);
412 ret = -EBADMSG;
413 goto exit;
414 }
415
416 ec_dev->max_request = EC_PROTO2_MAX_PARAM_SIZE;
417 ec_dev->max_response = EC_PROTO2_MAX_PARAM_SIZE;
418 ec_dev->max_passthru = 0;
419 ec_dev->pkt_xfer = NULL;
420 ec_dev->din_size = EC_PROTO2_MSG_BYTES;
421 ec_dev->dout_size = EC_PROTO2_MSG_BYTES;
422
423 dev_dbg(ec_dev->dev, "falling back to proto v2\n");
424 ret = 0;
425exit:
426 kfree(msg);
427 return ret;
428}
429
430/*
431 * cros_ec_get_host_command_version_mask
432 *
433 * Get the version mask of a given command.
434 *
435 * @ec_dev: EC device to call
436 * @msg: message structure to use
437 * @cmd: command to get the version of.
438 * @mask: result when function returns 0.
439 *
440 * @return 0 on success, error code otherwise
441 *
442 * LOCKING:
443 * the caller has ec_dev->lock mutex or the caller knows there is
444 * no other command in progress.
445 */
446static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev, u16 cmd, u32 *mask)
447{
448 struct ec_params_get_cmd_versions *pver;
449 struct ec_response_get_cmd_versions *rver;
450 struct cros_ec_command *msg;
451 int ret, mapped;
452
453 msg = kmalloc(sizeof(*msg) + max(sizeof(*rver), sizeof(*pver)),
454 GFP_KERNEL);
455 if (!msg)
456 return -ENOMEM;
457
458 msg->version = 0;
459 msg->command = EC_CMD_GET_CMD_VERSIONS;
460 msg->insize = sizeof(*rver);
461 msg->outsize = sizeof(*pver);
462
463 pver = (struct ec_params_get_cmd_versions *)msg->data;
464 pver->cmd = cmd;
465
466 ret = cros_ec_send_command(ec_dev, msg);
467 if (ret < 0)
468 goto exit;
469
470 mapped = cros_ec_map_error(msg->result);
471 if (mapped) {
472 ret = mapped;
473 goto exit;
474 }
475
476 if (ret == 0) {
477 ret = -EPROTO;
478 goto exit;
479 }
480
481 rver = (struct ec_response_get_cmd_versions *)msg->data;
482 *mask = rver->version_mask;
483 ret = 0;
484exit:
485 kfree(msg);
486 return ret;
487}
488
489/**
490 * cros_ec_query_all() - Query the protocol version supported by the
491 * ChromeOS EC.
492 * @ec_dev: Device to register.
493 *
494 * Return: 0 on success or negative error code.
495 */
496int cros_ec_query_all(struct cros_ec_device *ec_dev)
497{
498 struct device *dev = ec_dev->dev;
499 u32 ver_mask;
500 int ret;
501
502 /* First try sending with proto v3. */
503 if (!cros_ec_get_proto_info(ec_dev, CROS_EC_DEV_EC_INDEX)) {
504 /* Check for PD. */
505 cros_ec_get_proto_info(ec_dev, CROS_EC_DEV_PD_INDEX);
506 } else {
507 /* Try querying with a v2 hello message. */
508 ret = cros_ec_get_proto_info_legacy(ec_dev);
509 if (ret) {
510 /*
511 * It's possible for a test to occur too early when
512 * the EC isn't listening. If this happens, we'll
513 * test later when the first command is run.
514 */
515 ec_dev->proto_version = EC_PROTO_VERSION_UNKNOWN;
516 dev_dbg(ec_dev->dev, "EC query failed: %d\n", ret);
517 return ret;
518 }
519 }
520
521 devm_kfree(dev, ec_dev->din);
522 devm_kfree(dev, ec_dev->dout);
523
524 ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
525 if (!ec_dev->din) {
526 ret = -ENOMEM;
527 goto exit;
528 }
529
530 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
531 if (!ec_dev->dout) {
532 devm_kfree(dev, ec_dev->din);
533 ret = -ENOMEM;
534 goto exit;
535 }
536
537 /* Probe if MKBP event is supported */
538 ret = cros_ec_get_host_command_version_mask(ec_dev, EC_CMD_GET_NEXT_EVENT, &ver_mask);
539 if (ret < 0 || ver_mask == 0) {
540 ec_dev->mkbp_event_supported = 0;
541 } else {
542 ec_dev->mkbp_event_supported = fls(ver_mask);
543
544 dev_dbg(ec_dev->dev, "MKBP support version %u\n", ec_dev->mkbp_event_supported - 1);
545 }
546
547 /* Probe if host sleep v1 is supported for S0ix failure detection. */
548 ret = cros_ec_get_host_command_version_mask(ec_dev, EC_CMD_HOST_SLEEP_EVENT, &ver_mask);
549 ec_dev->host_sleep_v1 = (ret == 0 && (ver_mask & EC_VER_MASK(1)));
550
551 /* Get host event wake mask. */
552 ret = cros_ec_get_host_event_wake_mask(ec_dev, &ec_dev->host_event_wake_mask);
553 if (ret < 0) {
554 /*
555 * If the EC doesn't support EC_CMD_HOST_EVENT_GET_WAKE_MASK,
556 * use a reasonable default. Note that we ignore various
557 * battery, AC status, and power-state events, because (a)
558 * those can be quite common (e.g., when sitting at full
559 * charge, on AC) and (b) these are not actionable wake events;
560 * if anything, we'd like to continue suspending (to save
561 * power), not wake up.
562 */
563 ec_dev->host_event_wake_mask = U32_MAX &
564 ~(EC_HOST_EVENT_MASK(EC_HOST_EVENT_LID_CLOSED) |
565 EC_HOST_EVENT_MASK(EC_HOST_EVENT_AC_DISCONNECTED) |
566 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_LOW) |
567 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_CRITICAL) |
568 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY) |
569 EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
570 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_STATUS));
571 /*
572 * Old ECs may not support this command. Complain about all
573 * other errors.
574 */
575 if (ret != -EOPNOTSUPP)
576 dev_err(ec_dev->dev,
577 "failed to retrieve wake mask: %d\n", ret);
578 }
579
580 ret = 0;
581
582exit:
583 return ret;
584}
585EXPORT_SYMBOL(cros_ec_query_all);
586
587/**
588 * cros_ec_cmd_xfer() - Send a command to the ChromeOS EC.
589 * @ec_dev: EC device.
590 * @msg: Message to write.
591 *
592 * Call this to send a command to the ChromeOS EC. This should be used instead
593 * of calling the EC's cmd_xfer() callback directly. This function does not
594 * convert EC command execution error codes to Linux error codes. Most
595 * in-kernel users will want to use cros_ec_cmd_xfer_status() instead since
596 * that function implements the conversion.
597 *
598 * Return:
599 * >0 - EC command was executed successfully. The return value is the number
600 * of bytes returned by the EC (excluding the header).
601 * =0 - EC communication was successful. EC command execution results are
602 * reported in msg->result. The result will be EC_RES_SUCCESS if the
603 * command was executed successfully or report an EC command execution
604 * error.
605 * <0 - EC communication error. Return value is the Linux error code.
606 */
607int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev, struct cros_ec_command *msg)
608{
609 int ret;
610
611 mutex_lock(&ec_dev->lock);
612 if (ec_dev->proto_version == EC_PROTO_VERSION_UNKNOWN) {
613 ret = cros_ec_query_all(ec_dev);
614 if (ret) {
615 dev_err(ec_dev->dev,
616 "EC version unknown and query failed; aborting command\n");
617 mutex_unlock(&ec_dev->lock);
618 return ret;
619 }
620 }
621
622 if (msg->insize > ec_dev->max_response) {
623 dev_dbg(ec_dev->dev, "clamping message receive buffer\n");
624 msg->insize = ec_dev->max_response;
625 }
626
627 if (msg->command < EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX)) {
628 if (msg->outsize > ec_dev->max_request) {
629 dev_err(ec_dev->dev,
630 "request of size %u is too big (max: %u)\n",
631 msg->outsize,
632 ec_dev->max_request);
633 mutex_unlock(&ec_dev->lock);
634 return -EMSGSIZE;
635 }
636 } else {
637 if (msg->outsize > ec_dev->max_passthru) {
638 dev_err(ec_dev->dev,
639 "passthru rq of size %u is too big (max: %u)\n",
640 msg->outsize,
641 ec_dev->max_passthru);
642 mutex_unlock(&ec_dev->lock);
643 return -EMSGSIZE;
644 }
645 }
646
647 ret = cros_ec_send_command(ec_dev, msg);
648 mutex_unlock(&ec_dev->lock);
649
650 return ret;
651}
652EXPORT_SYMBOL(cros_ec_cmd_xfer);
653
654/**
655 * cros_ec_cmd_xfer_status() - Send a command to the ChromeOS EC.
656 * @ec_dev: EC device.
657 * @msg: Message to write.
658 *
659 * Call this to send a command to the ChromeOS EC. This should be used instead of calling the EC's
660 * cmd_xfer() callback directly. It returns success status only if both the command was transmitted
661 * successfully and the EC replied with success status.
662 *
663 * Return:
664 * >=0 - The number of bytes transferred.
665 * <0 - Linux error code
666 */
667int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
668 struct cros_ec_command *msg)
669{
670 int ret, mapped;
671
672 ret = cros_ec_cmd_xfer(ec_dev, msg);
673 if (ret < 0)
674 return ret;
675
676 mapped = cros_ec_map_error(msg->result);
677 if (mapped) {
678 dev_dbg(ec_dev->dev, "Command result (err: %d [%d])\n",
679 msg->result, mapped);
680 ret = mapped;
681 }
682
683 return ret;
684}
685EXPORT_SYMBOL(cros_ec_cmd_xfer_status);
686
687static int get_next_event_xfer(struct cros_ec_device *ec_dev,
688 struct cros_ec_command *msg,
689 struct ec_response_get_next_event_v1 *event,
690 int version, uint32_t size)
691{
692 int ret;
693
694 msg->version = version;
695 msg->command = EC_CMD_GET_NEXT_EVENT;
696 msg->insize = size;
697 msg->outsize = 0;
698
699 ret = cros_ec_cmd_xfer_status(ec_dev, msg);
700 if (ret > 0) {
701 ec_dev->event_size = ret - 1;
702 ec_dev->event_data = *event;
703 }
704
705 return ret;
706}
707
708static int get_next_event(struct cros_ec_device *ec_dev)
709{
710 struct {
711 struct cros_ec_command msg;
712 struct ec_response_get_next_event_v1 event;
713 } __packed buf;
714 struct cros_ec_command *msg = &buf.msg;
715 struct ec_response_get_next_event_v1 *event = &buf.event;
716 const int cmd_version = ec_dev->mkbp_event_supported - 1;
717
718 memset(msg, 0, sizeof(*msg));
719 if (ec_dev->suspended) {
720 dev_dbg(ec_dev->dev, "Device suspended.\n");
721 return -EHOSTDOWN;
722 }
723
724 if (cmd_version == 0)
725 return get_next_event_xfer(ec_dev, msg, event, 0,
726 sizeof(struct ec_response_get_next_event));
727
728 return get_next_event_xfer(ec_dev, msg, event, cmd_version,
729 sizeof(struct ec_response_get_next_event_v1));
730}
731
732static int get_keyboard_state_event(struct cros_ec_device *ec_dev)
733{
734 u8 buffer[sizeof(struct cros_ec_command) +
735 sizeof(ec_dev->event_data.data)];
736 struct cros_ec_command *msg = (struct cros_ec_command *)&buffer;
737
738 msg->version = 0;
739 msg->command = EC_CMD_MKBP_STATE;
740 msg->insize = sizeof(ec_dev->event_data.data);
741 msg->outsize = 0;
742
743 ec_dev->event_size = cros_ec_cmd_xfer_status(ec_dev, msg);
744 ec_dev->event_data.event_type = EC_MKBP_EVENT_KEY_MATRIX;
745 memcpy(&ec_dev->event_data.data, msg->data,
746 sizeof(ec_dev->event_data.data));
747
748 return ec_dev->event_size;
749}
750
751/**
752 * cros_ec_get_next_event() - Fetch next event from the ChromeOS EC.
753 * @ec_dev: Device to fetch event from.
754 * @wake_event: Pointer to a bool set to true upon return if the event might be
755 * treated as a wake event. Ignored if null.
756 * @has_more_events: Pointer to bool set to true if more than one event is
757 * pending.
758 * Some EC will set this flag to indicate cros_ec_get_next_event()
759 * can be called multiple times in a row.
760 * It is an optimization to prevent issuing a EC command for
761 * nothing or wait for another interrupt from the EC to process
762 * the next message.
763 * Ignored if null.
764 *
765 * Return: negative error code on errors; 0 for no data; or else number of
766 * bytes received (i.e., an event was retrieved successfully). Event types are
767 * written out to @ec_dev->event_data.event_type on success.
768 */
769int cros_ec_get_next_event(struct cros_ec_device *ec_dev,
770 bool *wake_event,
771 bool *has_more_events)
772{
773 u8 event_type;
774 u32 host_event;
775 int ret;
776 u32 ver_mask;
777
778 /*
779 * Default value for wake_event.
780 * Wake up on keyboard event, wake up for spurious interrupt or link
781 * error to the EC.
782 */
783 if (wake_event)
784 *wake_event = true;
785
786 /*
787 * Default value for has_more_events.
788 * EC will raise another interrupt if AP does not process all events
789 * anyway.
790 */
791 if (has_more_events)
792 *has_more_events = false;
793
794 if (!ec_dev->mkbp_event_supported)
795 return get_keyboard_state_event(ec_dev);
796
797 ret = get_next_event(ec_dev);
798 /*
799 * -ENOPROTOOPT is returned when EC returns EC_RES_INVALID_VERSION.
800 * This can occur when EC based device (e.g. Fingerprint MCU) jumps to
801 * the RO image which doesn't support newer version of the command. In
802 * this case we will attempt to update maximum supported version of the
803 * EC_CMD_GET_NEXT_EVENT.
804 */
805 if (ret == -ENOPROTOOPT) {
806 dev_dbg(ec_dev->dev,
807 "GET_NEXT_EVENT returned invalid version error.\n");
808 ret = cros_ec_get_host_command_version_mask(ec_dev,
809 EC_CMD_GET_NEXT_EVENT,
810 &ver_mask);
811 if (ret < 0 || ver_mask == 0)
812 /*
813 * Do not change the MKBP supported version if we can't
814 * obtain supported version correctly. Please note that
815 * calling EC_CMD_GET_NEXT_EVENT returned
816 * EC_RES_INVALID_VERSION which means that the command
817 * is present.
818 */
819 return -ENOPROTOOPT;
820
821 ec_dev->mkbp_event_supported = fls(ver_mask);
822 dev_dbg(ec_dev->dev, "MKBP support version changed to %u\n",
823 ec_dev->mkbp_event_supported - 1);
824
825 /* Try to get next event with new MKBP support version set. */
826 ret = get_next_event(ec_dev);
827 }
828
829 if (ret <= 0)
830 return ret;
831
832 if (has_more_events)
833 *has_more_events = ec_dev->event_data.event_type &
834 EC_MKBP_HAS_MORE_EVENTS;
835 ec_dev->event_data.event_type &= EC_MKBP_EVENT_TYPE_MASK;
836
837 if (wake_event) {
838 event_type = ec_dev->event_data.event_type;
839 host_event = cros_ec_get_host_event(ec_dev);
840
841 /*
842 * Sensor events need to be parsed by the sensor sub-device.
843 * Defer them, and don't report the wakeup here.
844 */
845 if (event_type == EC_MKBP_EVENT_SENSOR_FIFO) {
846 *wake_event = false;
847 } else if (host_event) {
848 /* rtc_update_irq() already handles wakeup events. */
849 if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_RTC))
850 *wake_event = false;
851 /* Masked host-events should not count as wake events. */
852 if (!(host_event & ec_dev->host_event_wake_mask))
853 *wake_event = false;
854 }
855 }
856
857 return ret;
858}
859EXPORT_SYMBOL(cros_ec_get_next_event);
860
861/**
862 * cros_ec_get_host_event() - Return a mask of event set by the ChromeOS EC.
863 * @ec_dev: Device to fetch event from.
864 *
865 * When MKBP is supported, when the EC raises an interrupt, we collect the
866 * events raised and call the functions in the ec notifier. This function
867 * is a helper to know which events are raised.
868 *
869 * Return: 0 on error or non-zero bitmask of one or more EC_HOST_EVENT_*.
870 */
871u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev)
872{
873 u32 host_event;
874
875 if (!ec_dev->mkbp_event_supported)
876 return 0;
877
878 if (ec_dev->event_data.event_type != EC_MKBP_EVENT_HOST_EVENT)
879 return 0;
880
881 if (ec_dev->event_size != sizeof(host_event)) {
882 dev_warn(ec_dev->dev, "Invalid host event size\n");
883 return 0;
884 }
885
886 host_event = get_unaligned_le32(&ec_dev->event_data.data.host_event);
887
888 return host_event;
889}
890EXPORT_SYMBOL(cros_ec_get_host_event);
891
892/**
893 * cros_ec_check_features() - Test for the presence of EC features
894 *
895 * @ec: EC device, does not have to be connected directly to the AP,
896 * can be daisy chained through another device.
897 * @feature: One of ec_feature_code bit.
898 *
899 * Call this function to test whether the ChromeOS EC supports a feature.
900 *
901 * Return: true if supported, false if not (or if an error was encountered).
902 */
903bool cros_ec_check_features(struct cros_ec_dev *ec, int feature)
904{
905 struct ec_response_get_features *features = &ec->features;
906 int ret;
907
908 if (features->flags[0] == -1U && features->flags[1] == -1U) {
909 /* features bitmap not read yet */
910 ret = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_GET_FEATURES + ec->cmd_offset,
911 NULL, 0, features, sizeof(*features));
912 if (ret < 0) {
913 dev_warn(ec->dev, "cannot get EC features: %d\n", ret);
914 memset(features, 0, sizeof(*features));
915 }
916
917 dev_dbg(ec->dev, "EC features %08x %08x\n",
918 features->flags[0], features->flags[1]);
919 }
920
921 return !!(features->flags[feature / 32] & EC_FEATURE_MASK_0(feature));
922}
923EXPORT_SYMBOL_GPL(cros_ec_check_features);
924
925/**
926 * cros_ec_get_sensor_count() - Return the number of MEMS sensors supported.
927 *
928 * @ec: EC device, does not have to be connected directly to the AP,
929 * can be daisy chained through another device.
930 * Return: < 0 in case of error.
931 */
932int cros_ec_get_sensor_count(struct cros_ec_dev *ec)
933{
934 /*
935 * Issue a command to get the number of sensor reported.
936 * If not supported, check for legacy mode.
937 */
938 int ret, sensor_count;
939 struct ec_params_motion_sense *params;
940 struct ec_response_motion_sense *resp;
941 struct cros_ec_command *msg;
942 struct cros_ec_device *ec_dev = ec->ec_dev;
943 u8 status;
944
945 msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*resp)),
946 GFP_KERNEL);
947 if (!msg)
948 return -ENOMEM;
949
950 msg->version = 1;
951 msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
952 msg->outsize = sizeof(*params);
953 msg->insize = sizeof(*resp);
954
955 params = (struct ec_params_motion_sense *)msg->data;
956 params->cmd = MOTIONSENSE_CMD_DUMP;
957
958 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
959 if (ret < 0) {
960 sensor_count = ret;
961 } else {
962 resp = (struct ec_response_motion_sense *)msg->data;
963 sensor_count = resp->dump.sensor_count;
964 }
965 kfree(msg);
966
967 /*
968 * Check legacy mode: Let's find out if sensors are accessible
969 * via LPC interface.
970 */
971 if (sensor_count < 0 && ec->cmd_offset == 0 && ec_dev->cmd_readmem) {
972 ret = ec_dev->cmd_readmem(ec_dev, EC_MEMMAP_ACC_STATUS,
973 1, &status);
974 if (ret >= 0 &&
975 (status & EC_MEMMAP_ACC_STATUS_PRESENCE_BIT)) {
976 /*
977 * We have 2 sensors, one in the lid, one in the base.
978 */
979 sensor_count = 2;
980 } else {
981 /*
982 * EC uses LPC interface and no sensors are presented.
983 */
984 sensor_count = 0;
985 }
986 }
987 return sensor_count;
988}
989EXPORT_SYMBOL_GPL(cros_ec_get_sensor_count);
990
991/**
992 * cros_ec_cmd - Send a command to the EC.
993 *
994 * @ec_dev: EC device
995 * @version: EC command version
996 * @command: EC command
997 * @outdata: EC command output data
998 * @outsize: Size of outdata
999 * @indata: EC command input data
1000 * @insize: Size of indata
1001 *
1002 * Return: >= 0 on success, negative error number on failure.
1003 */
1004int cros_ec_cmd(struct cros_ec_device *ec_dev,
1005 unsigned int version,
1006 int command,
1007 const void *outdata,
1008 size_t outsize,
1009 void *indata,
1010 size_t insize)
1011{
1012 struct cros_ec_command *msg;
1013 int ret;
1014
1015 msg = kzalloc(sizeof(*msg) + max(insize, outsize), GFP_KERNEL);
1016 if (!msg)
1017 return -ENOMEM;
1018
1019 msg->version = version;
1020 msg->command = command;
1021 msg->outsize = outsize;
1022 msg->insize = insize;
1023
1024 if (outsize)
1025 memcpy(msg->data, outdata, outsize);
1026
1027 ret = cros_ec_cmd_xfer_status(ec_dev, msg);
1028 if (ret < 0)
1029 goto error;
1030
1031 if (insize)
1032 memcpy(indata, msg->data, insize);
1033error:
1034 kfree(msg);
1035 return ret;
1036}
1037EXPORT_SYMBOL_GPL(cros_ec_cmd);