summaryrefslogtreecommitdiffstats
path: root/drivers/platform/chrome/cros_ec_proto.c
blob: aa7f7aa77297161b90b687b931cbd8169dee0c42 (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
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
// SPDX-License-Identifier: GPL-2.0
// ChromeOS EC communication protocol helper functions
//
// Copyright (C) 2015 Google, Inc

#include <linux/delay.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/slab.h>
#include <asm/unaligned.h>

#include "cros_ec_trace.h"

#define EC_COMMAND_RETRIES	50

static const int cros_ec_error_map[] = {
	[EC_RES_INVALID_COMMAND] = -EOPNOTSUPP,
	[EC_RES_ERROR] = -EIO,
	[EC_RES_INVALID_PARAM] = -EINVAL,
	[EC_RES_ACCESS_DENIED] = -EACCES,
	[EC_RES_INVALID_RESPONSE] = -EPROTO,
	[EC_RES_INVALID_VERSION] = -ENOPROTOOPT,
	[EC_RES_INVALID_CHECKSUM] = -EBADMSG,
	[EC_RES_IN_PROGRESS] = -EINPROGRESS,
	[EC_RES_UNAVAILABLE] = -ENODATA,
	[EC_RES_TIMEOUT] = -ETIMEDOUT,
	[EC_RES_OVERFLOW] = -EOVERFLOW,
	[EC_RES_INVALID_HEADER] = -EBADR,
	[EC_RES_REQUEST_TRUNCATED] = -EBADR,
	[EC_RES_RESPONSE_TOO_BIG] = -EFBIG,
	[EC_RES_BUS_ERROR] = -EFAULT,
	[EC_RES_BUSY] = -EBUSY,
	[EC_RES_INVALID_HEADER_VERSION] = -EBADMSG,
	[EC_RES_INVALID_HEADER_CRC] = -EBADMSG,
	[EC_RES_INVALID_DATA_CRC] = -EBADMSG,
	[EC_RES_DUP_UNAVAILABLE] = -ENODATA,
};

static int cros_ec_map_error(uint32_t result)
{
	int ret = 0;

	if (result != EC_RES_SUCCESS) {
		if (result < ARRAY_SIZE(cros_ec_error_map) && cros_ec_error_map[result])
			ret = cros_ec_error_map[result];
		else
			ret = -EPROTO;
	}

	return ret;
}

static int prepare_packet(struct cros_ec_device *ec_dev,
			  struct cros_ec_command *msg)
{
	struct ec_host_request *request;
	u8 *out;
	int i;
	u8 csum = 0;

	BUG_ON(ec_dev->proto_version != EC_HOST_REQUEST_VERSION);
	BUG_ON(msg->outsize + sizeof(*request) > ec_dev->dout_size);

	out = ec_dev->dout;
	request = (struct ec_host_request *)out;
	request->struct_version = EC_HOST_REQUEST_VERSION;
	request->checksum = 0;
	request->command = msg->command;
	request->command_version = msg->version;
	request->reserved = 0;
	request->data_len = msg->outsize;

	for (i = 0; i < sizeof(*request); i++)
		csum += out[i];

	/* Copy data and update checksum */
	memcpy(out + sizeof(*request), msg->data, msg->outsize);
	for (i = 0; i < msg->outsize; i++)
		csum += msg->data[i];

	request->checksum = -csum;

	return sizeof(*request) + msg->outsize;
}

static int send_command(struct cros_ec_device *ec_dev,
			struct cros_ec_command *msg)
{
	int ret;
	int (*xfer_fxn)(struct cros_ec_device *ec, struct cros_ec_command *msg);

	if (ec_dev->proto_version > 2)
		xfer_fxn = ec_dev->pkt_xfer;
	else
		xfer_fxn = ec_dev->cmd_xfer;

	if (!xfer_fxn) {
		/*
		 * This error can happen if a communication error happened and
		 * the EC is trying to use protocol v2, on an underlying
		 * communication mechanism that does not support v2.
		 */
		dev_err_once(ec_dev->dev,
			     "missing EC transfer API, cannot send command\n");
		return -EIO;
	}

	trace_cros_ec_request_start(msg);
	ret = (*xfer_fxn)(ec_dev, msg);
	trace_cros_ec_request_done(msg, ret);
	if (msg->result == EC_RES_IN_PROGRESS) {
		int i;
		struct cros_ec_command *status_msg;
		struct ec_response_get_comms_status *status;

		status_msg = kmalloc(sizeof(*status_msg) + sizeof(*status),
				     GFP_KERNEL);
		if (!status_msg)
			return -ENOMEM;

		status_msg->version = 0;
		status_msg->command = EC_CMD_GET_COMMS_STATUS;
		status_msg->insize = sizeof(*status);
		status_msg->outsize = 0;

		/*
		 * Query the EC's status until it's no longer busy or
		 * we encounter an error.
		 */
		for (i = 0; i < EC_COMMAND_RETRIES; i++) {
			usleep_range(10000, 11000);

			trace_cros_ec_request_start(status_msg);
			ret = (*xfer_fxn)(ec_dev, status_msg);
			trace_cros_ec_request_done(status_msg, ret);
			if (ret == -EAGAIN)
				continue;
			if (ret < 0)
				break;

			msg->result = status_msg->result;
			if (status_msg->result != EC_RES_SUCCESS)
				break;

			status = (struct ec_response_get_comms_status *)
				 status_msg->data;
			if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
				break;
		}

		kfree(status_msg);
	}

	return ret;
}

/**
 * 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)
{
	u8 *out;
	u8 csum;
	int i;

	if (ec_dev->proto_version > 2)
		return prepare_packet(ec_dev, msg);

	BUG_ON(msg->outsize > EC_PROTO2_MAX_PARAM_SIZE);
	out = ec_dev->dout;
	out[0] = EC_CMD_VERSION0 + msg->version;
	out[1] = msg->command;
	out[2] = msg->outsize;
	csum = out[0] + out[1] + out[2];
	for (i = 0; i < msg->outsize; i++)
		csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->data[i];
	out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = csum;

	return EC_MSG_TX_PROTO_BYTES + msg->outsize;
}
EXPORT_SYMBOL(cros_ec_prepare_tx);

/**
 * 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)
{
	switch (msg->result) {
	case EC_RES_SUCCESS:
		return 0;
	case EC_RES_IN_PROGRESS:
		dev_dbg(ec_dev->dev, "command 0x%02x in progress\n",
			msg->command);
		return -EAGAIN;
	default:
		dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n",
			msg->command, msg->result);
		return 0;
	}
}
EXPORT_SYMBOL(cros_ec_check_result);

/*
 * cros_ec_get_host_event_wake_mask
 *
 * Get the mask of host events that cause wake from suspend.
 *
 * @ec_dev: EC device to call
 * @msg: message structure to use
 * @mask: result when function returns >=0.
 *
 * LOCKING:
 * the caller has ec_dev->lock mutex, or the caller knows there is
 * no other command in progress.
 */
static int cros_ec_get_host_event_wake_mask(struct cros_ec_device *ec_dev,
					    struct cros_ec_command *msg,
					    uint32_t *mask)
{
	struct ec_response_host_event_mask *r;
	int ret;

	msg->command = EC_CMD_HOST_EVENT_GET_WAKE_MASK;
	msg->version = 0;
	msg->outsize = 0;
	msg->insize = sizeof(*r);

	ret = send_command(ec_dev, msg);
	if (ret >= 0) {
		if (msg->result == EC_RES_INVALID_COMMAND)
			return -EOPNOTSUPP;
		if (msg->result != EC_RES_SUCCESS)
			return -EPROTO;
	}
	if (ret > 0) {
		r = (struct ec_response_host_event_mask *)msg->data;
		*mask = r->mask;
	}

	return ret;
}

static int cros_ec_host_command_proto_query(struct cros_ec_device *ec_dev,
					    int devidx,
					    struct cros_ec_command *msg)
{
	/*
	 * Try using v3+ to query for supported protocols. If this
	 * command fails, fall back to v2. Returns the highest protocol
	 * supported by the EC.
	 * Also sets the max request/response/passthru size.
	 */
	int ret;

	if (!ec_dev->pkt_xfer)
		return -EPROTONOSUPPORT;

	memset(msg, 0, sizeof(*msg));
	msg->command = EC_CMD_PASSTHRU_OFFSET(devidx) | EC_CMD_GET_PROTOCOL_INFO;
	msg->insize = sizeof(struct ec_response_get_protocol_info);

	ret = send_command(ec_dev, msg);

	if (ret < 0) {
		dev_dbg(ec_dev->dev,
			"failed to check for EC[%d] protocol version: %d\n",
			devidx, ret);
		return ret;
	}

	if (devidx > 0 && msg->result == EC_RES_INVALID_COMMAND)
		return -ENODEV;
	else if (msg->result != EC_RES_SUCCESS)
		return msg->result;

	return 0;
}

static int cros_ec_host_command_proto_query_v2(struct cros_ec_device *ec_dev)
{
	struct cros_ec_command *msg;
	struct ec_params_hello *hello_params;
	struct ec_response_hello *hello_response;
	int ret;
	int len = max(sizeof(*hello_params), sizeof(*hello_response));

	msg = kmalloc(sizeof(*msg) + len, GFP_KERNEL);
	if (!msg)
		return -ENOMEM;

	msg->version = 0;
	msg->command = EC_CMD_HELLO;
	hello_params = (struct ec_params_hello *)msg->data;
	msg->outsize = sizeof(*hello_params);
	hello_response = (struct ec_response_hello *)msg->data;
	msg->insize = sizeof(*hello_response);

	hello_params->in_data = 0xa0b0c0d0;

	ret = send_command(ec_dev, msg);

	if (ret < 0) {
		dev_dbg(ec_dev->dev,
			"EC failed to respond to v2 hello: %d\n",
			ret);
		goto exit;
	} else if (msg->result != EC_RES_SUCCESS) {
		dev_err(ec_dev->dev,
			"EC responded to v2 hello with error: %d\n",
			msg->result);
		ret = msg->result;
		goto exit;
	} else if (hello_response->out_data != 0xa1b2c3d4) {
		dev_err(ec_dev->dev,
			"EC responded to v2 hello with bad result: %u\n",
			hello_response->out_data);
		ret = -EBADMSG;
		goto exit;
	}

	ret = 0;

 exit:
	kfree(msg);
	return ret;
}

/*
 * cros_ec_get_host_command_version_mask
 *
 * Get the version mask of a given command.
 *
 * @ec_dev: EC device to call
 * @msg: message structure to use
 * @cmd: command to get the version of.
 * @mask: result when function returns 0.
 *
 * @return 0 on success, error code otherwise
 *
 * LOCKING:
 * the caller has ec_dev->lock mutex or the caller knows there is
 * no other command in progress.
 */
static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
	u16 cmd, u32 *mask)
{
	struct ec_params_get_cmd_versions *pver;
	struct ec_response_get_cmd_versions *rver;
	struct cros_ec_command *msg;
	int ret;

	msg = kmalloc(sizeof(*msg) + max(sizeof(*rver), sizeof(*pver)),
		      GFP_KERNEL);
	if (!msg)
		return -ENOMEM;

	msg->version = 0;
	msg->command = EC_CMD_GET_CMD_VERSIONS;
	msg->insize = sizeof(*rver);
	msg->outsize = sizeof(*pver);

	pver = (struct ec_params_get_cmd_versions *)msg->data;
	pver->cmd = cmd;

	ret = send_command(ec_dev, msg);
	if (ret > 0) {
		rver = (struct ec_response_get_cmd_versions *)msg->data;
		*mask = rver->version_mask;
	}

	kfree(msg);

	return ret;
}

/**
 * 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)
{
	struct device *dev = ec_dev->dev;
	struct cros_ec_command *proto_msg;
	struct ec_response_get_protocol_info *proto_info;
	u32 ver_mask = 0;
	int ret;

	proto_msg = kzalloc(sizeof(*proto_msg) + sizeof(*proto_info),
			    GFP_KERNEL);
	if (!proto_msg)
		return -ENOMEM;

	/* First try sending with proto v3. */
	ec_dev->proto_version = 3;
	ret = cros_ec_host_command_proto_query(ec_dev, 0, proto_msg);

	if (ret == 0) {
		proto_info = (struct ec_response_get_protocol_info *)
			proto_msg->data;
		ec_dev->max_request = proto_info->max_request_packet_size -
			sizeof(struct ec_host_request);
		ec_dev->max_response = proto_info->max_response_packet_size -
			sizeof(struct ec_host_response);
		ec_dev->proto_version =
			min(EC_HOST_REQUEST_VERSION,
					fls(proto_info->protocol_versions) - 1);
		dev_dbg(ec_dev->dev,
			"using proto v%u\n",
			ec_dev->proto_version);

		ec_dev->din_size = ec_dev->max_response +
			sizeof(struct ec_host_response) +
			EC_MAX_RESPONSE_OVERHEAD;
		ec_dev->dout_size = ec_dev->max_request +
			sizeof(struct ec_host_request) +
			EC_MAX_REQUEST_OVERHEAD;

		/*
		 * Check for PD
		 */
		ret = cros_ec_host_command_proto_query(ec_dev, 1, proto_msg);

		if (ret) {
			dev_dbg(ec_dev->dev, "no PD chip found: %d\n", ret);
			ec_dev->max_passthru = 0;
		} else {
			dev_dbg(ec_dev->dev, "found PD chip\n");
			ec_dev->max_passthru =
				proto_info->max_request_packet_size -
				sizeof(struct ec_host_request);
		}
	} else {
		/* Try querying with a v2 hello message. */
		ec_dev->proto_version = 2;
		ret = cros_ec_host_command_proto_query_v2(ec_dev);

		if (ret == 0) {
			/* V2 hello succeeded. */
			dev_dbg(ec_dev->dev, "falling back to proto v2\n");

			ec_dev->max_request = EC_PROTO2_MAX_PARAM_SIZE;
			ec_dev->max_response = EC_PROTO2_MAX_PARAM_SIZE;
			ec_dev->max_passthru = 0;
			ec_dev->pkt_xfer = NULL;
			ec_dev->din_size = EC_PROTO2_MSG_BYTES;
			ec_dev->dout_size = EC_PROTO2_MSG_BYTES;
		} else {
			/*
			 * It's possible for a test to occur too early when
			 * the EC isn't listening. If this happens, we'll
			 * test later when the first command is run.
			 */
			ec_dev->proto_version = EC_PROTO_VERSION_UNKNOWN;
			dev_dbg(ec_dev->dev, "EC query failed: %d\n", ret);
			goto exit;
		}
	}

	devm_kfree(dev, ec_dev->din);
	devm_kfree(dev, ec_dev->dout);

	ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
	if (!ec_dev->din) {
		ret = -ENOMEM;
		goto exit;
	}

	ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
	if (!ec_dev->dout) {
		devm_kfree(dev, ec_dev->din);
		ret = -ENOMEM;
		goto exit;
	}

	/* Probe if MKBP event is supported */
	ret = cros_ec_get_host_command_version_mask(ec_dev,
						    EC_CMD_GET_NEXT_EVENT,
						    &ver_mask);
	if (ret < 0 || ver_mask == 0)
		ec_dev->mkbp_event_supported = 0;
	else
		ec_dev->mkbp_event_supported = fls(ver_mask);

	dev_dbg(ec_dev->dev, "MKBP support version %u\n",
		ec_dev->mkbp_event_supported - 1);

	/* Probe if host sleep v1 is supported for S0ix failure detection. */
	ret = cros_ec_get_host_command_version_mask(ec_dev,
						    EC_CMD_HOST_SLEEP_EVENT,
						    &ver_mask);
	ec_dev->host_sleep_v1 = (ret >= 0 && (ver_mask & EC_VER_MASK(1)));

	/* Get host event wake mask. */
	ret = cros_ec_get_host_event_wake_mask(ec_dev, proto_msg,
					       &ec_dev->host_event_wake_mask);
	if (ret < 0) {
		/*
		 * If the EC doesn't support EC_CMD_HOST_EVENT_GET_WAKE_MASK,
		 * use a reasonable default. Note that we ignore various
		 * battery, AC status, and power-state events, because (a)
		 * those can be quite common (e.g., when sitting at full
		 * charge, on AC) and (b) these are not actionable wake events;
		 * if anything, we'd like to continue suspending (to save
		 * power), not wake up.
		 */
		ec_dev->host_event_wake_mask = U32_MAX &
			~(EC_HOST_EVENT_MASK(EC_HOST_EVENT_LID_CLOSED) |
			  EC_HOST_EVENT_MASK(EC_HOST_EVENT_AC_DISCONNECTED) |
			  EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_LOW) |
			  EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_CRITICAL) |
			  EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY) |
			  EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
			  EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_STATUS));
		/*
		 * Old ECs may not support this command. Complain about all
		 * other errors.
		 */
		if (ret != -EOPNOTSUPP)
			dev_err(ec_dev->dev,
				"failed to retrieve wake mask: %d\n", ret);
	}

	ret = 0;

exit:
	kfree(proto_msg);
	return ret;
}
EXPORT_SYMBOL(cros_ec_query_all);

/**
 * cros_ec_cmd_xfer_status() - 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. It returns success status only if both the command was transmitted
 * successfully and the EC replied with success status.
 *
 * Return:
 * >=0 - The number of bytes transferred
 * <0 - Linux error code
 */
int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
			    struct cros_ec_command *msg)
{
	int ret, mapped;

	mutex_lock(&ec_dev->lock);
	if (ec_dev->proto_version == EC_PROTO_VERSION_UNKNOWN) {
		ret = cros_ec_query_all(ec_dev);
		if (ret) {
			dev_err(ec_dev->dev,
				"EC version unknown and query failed; aborting command\n");
			mutex_unlock(&ec_dev->lock);
			return ret;
		}
	}

	if (msg->insize > ec_dev->max_response) {
		dev_dbg(ec_dev->dev, "clamping message receive buffer\n");
		msg->insize = ec_dev->max_response;
	}

	if (msg->command < EC_CMD_PASSTHRU_OFFSET(1)) {
		if (msg->outsize > ec_dev->max_request) {
			dev_err(ec_dev->dev,
				"request of size %u is too big (max: %u)\n",
				msg->outsize,
				ec_dev->max_request);
			mutex_unlock(&ec_dev->lock);
			return -EMSGSIZE;
		}
	} else {
		if (msg->outsize > ec_dev->max_passthru) {
			dev_err(ec_dev->dev,
				"passthru rq of size %u is too big (max: %u)\n",
				msg->outsize,
				ec_dev->max_passthru);
			mutex_unlock(&ec_dev->lock);
			return -EMSGSIZE;
		}
	}

	ret = send_command(ec_dev, msg);
	mutex_unlock(&ec_dev->lock);

	mapped = cros_ec_map_error(msg->result);
	if (mapped) {
		dev_dbg(ec_dev->dev, "Command result (err: %d [%d])\n",
			msg->result, mapped);
		ret = mapped;
	}

	return ret;
}
EXPORT_SYMBOL(cros_ec_cmd_xfer_status);

static int 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)
{
	int ret;

	msg->version = version;
	msg->command = EC_CMD_GET_NEXT_EVENT;
	msg->insize = size;
	msg->outsize = 0;

	ret = cros_ec_cmd_xfer_status(ec_dev, msg);
	if (ret > 0) {
		ec_dev->event_size = ret - 1;
		ec_dev->event_data = *event;
	}

	return ret;
}

static int get_next_event(struct cros_ec_device *ec_dev)
{
	struct {
		struct cros_ec_command msg;
		struct ec_response_get_next_event_v1 event;
	} __packed buf;
	struct cros_ec_command *msg = &buf.msg;
	struct ec_response_get_next_event_v1 *event = &buf.event;
	const int cmd_version = ec_dev->mkbp_event_supported - 1;

	memset(msg, 0, sizeof(*msg));
	if (ec_dev->suspended) {
		dev_dbg(ec_dev->dev, "Device suspended.\n");
		return -EHOSTDOWN;
	}

	if (cmd_version == 0)
		return get_next_event_xfer(ec_dev, msg, event, 0,
				  sizeof(struct ec_response_get_next_event));

	return get_next_event_xfer(ec_dev, msg, event, cmd_version,
				sizeof(struct ec_response_get_next_event_v1));
}

static int get_keyboard_state_event(struct cros_ec_device *ec_dev)
{
	u8 buffer[sizeof(struct cros_ec_command) +
		  sizeof(ec_dev->event_data.data)];
	struct cros_ec_command *msg = (struct cros_ec_command *)&buffer;

	msg->version = 0;
	msg->command = EC_CMD_MKBP_STATE;
	msg->insize = sizeof(ec_dev->event_data.data);
	msg->outsize = 0;

	ec_dev->event_size = cros_ec_cmd_xfer_status(ec_dev, msg);
	ec_dev->event_data.event_type = EC_MKBP_EVENT_KEY_MATRIX;
	memcpy(&ec_dev->event_data.data, msg->data,
	       sizeof(ec_dev->event_data.data));

	return ec_dev->event_size;
}

/**
 * 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.
 * @has_more_events: Pointer to bool set to true if more than one event is
 *              pending.
 *              Some EC will set this flag to indicate cros_ec_get_next_event()
 *              can be called multiple times in a row.
 *              It is an optimization to prevent issuing a EC command for
 *              nothing or wait for another interrupt from the EC to process
 *              the next message.
 *              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,
			   bool *has_more_events)
{
	u8 event_type;
	u32 host_event;
	int ret;

	/*
	 * Default value for wake_event.
	 * Wake up on keyboard event, wake up for spurious interrupt or link
	 * error to the EC.
	 */
	if (wake_event)
		*wake_event = true;

	/*
	 * Default value for has_more_events.
	 * EC will raise another interrupt if AP does not process all events
	 * anyway.
	 */
	if (has_more_events)
		*has_more_events = false;

	if (!ec_dev->mkbp_event_supported)
		return get_keyboard_state_event(ec_dev);

	ret = get_next_event(ec_dev);
	if (ret <= 0)
		return ret;

	if (has_more_events)
		*has_more_events = ec_dev->event_data.event_type &
			EC_MKBP_HAS_MORE_EVENTS;
	ec_dev->event_data.event_type &= EC_MKBP_EVENT_TYPE_MASK;

	if (wake_event) {
		event_type = ec_dev->event_data.event_type;
		host_event = cros_ec_get_host_event(ec_dev);

		/*
		 * Sensor events need to be parsed by the sensor sub-device.
		 * Defer them, and don't report the wakeup here.
		 */
		if (event_type == EC_MKBP_EVENT_SENSOR_FIFO) {
			*wake_event = false;
		} else if (host_event) {
			/* rtc_update_irq() already handles wakeup events. */
			if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_RTC))
				*wake_event = false;
			/* Masked host-events should not count as wake events. */
			if (!(host_event & ec_dev->host_event_wake_mask))
				*wake_event = false;
		}
	}

	return ret;
}
EXPORT_SYMBOL(cros_ec_get_next_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)
{
	u32 host_event;

	BUG_ON(!ec_dev->mkbp_event_supported);

	if (ec_dev->event_data.event_type != EC_MKBP_EVENT_HOST_EVENT)
		return 0;

	if (ec_dev->event_size != sizeof(host_event)) {
		dev_warn(ec_dev->dev, "Invalid host event size\n");
		return 0;
	}

	host_event = get_unaligned_le32(&ec_dev->event_data.data.host_event);

	return host_event;
}
EXPORT_SYMBOL(cros_ec_get_host_event);

/**
 * cros_ec_check_features() - Test for the presence of EC features
 *
 * @ec: EC device, does not have to be connected directly to the AP,
 *      can be daisy chained through another device.
 * @feature: One of ec_feature_code bit.
 *
 * Call this function to test whether the ChromeOS EC supports a feature.
 *
 * Return: 1 if supported, 0 if not
 */
int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
{
	struct cros_ec_command *msg;
	int ret;

	if (ec->features[0] == -1U && ec->features[1] == -1U) {
		/* features bitmap not read yet */
		msg = kzalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
		if (!msg)
			return -ENOMEM;

		msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
		msg->insize = sizeof(ec->features);

		ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
		if (ret < 0) {
			dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
				 ret, msg->result);
			memset(ec->features, 0, sizeof(ec->features));
		} else {
			memcpy(ec->features, msg->data, sizeof(ec->features));
		}

		dev_dbg(ec->dev, "EC features %08x %08x\n",
			ec->features[0], ec->features[1]);

		kfree(msg);
	}

	return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
}
EXPORT_SYMBOL_GPL(cros_ec_check_features);

/**
 * cros_ec_get_sensor_count() - Return the number of MEMS sensors supported.
 *
 * @ec: EC device, does not have to be connected directly to the AP,
 *      can be daisy chained through another device.
 * Return: < 0 in case of error.
 */
int cros_ec_get_sensor_count(struct cros_ec_dev *ec)
{
	/*
	 * Issue a command to get the number of sensor reported.
	 * If not supported, check for legacy mode.
	 */
	int ret, sensor_count;
	struct ec_params_motion_sense *params;
	struct ec_response_motion_sense *resp;
	struct cros_ec_command *msg;
	struct cros_ec_device *ec_dev = ec->ec_dev;
	u8 status;

	msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*resp)),
		      GFP_KERNEL);
	if (!msg)
		return -ENOMEM;

	msg->version = 1;
	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
	msg->outsize = sizeof(*params);
	msg->insize = sizeof(*resp);

	params = (struct ec_params_motion_sense *)msg->data;
	params->cmd = MOTIONSENSE_CMD_DUMP;

	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
	if (ret < 0) {
		sensor_count = ret;
	} else {
		resp = (struct ec_response_motion_sense *)msg->data;
		sensor_count = resp->dump.sensor_count;
	}
	kfree(msg);

	/*
	 * Check legacy mode: Let's find out if sensors are accessible
	 * via LPC interface.
	 */
	if (sensor_count < 0 && ec->cmd_offset == 0 && ec_dev->cmd_readmem) {
		ret = ec_dev->cmd_readmem(ec_dev, EC_MEMMAP_ACC_STATUS,
				1, &status);
		if (ret >= 0 &&
		    (status & EC_MEMMAP_ACC_STATUS_PRESENCE_BIT)) {
			/*
			 * We have 2 sensors, one in the lid, one in the base.
			 */
			sensor_count = 2;
		} else {
			/*
			 * EC uses LPC interface and no sensors are presented.
			 */
			sensor_count = 0;
		}
	}
	return sensor_count;
}
EXPORT_SYMBOL_GPL(cros_ec_get_sensor_count);