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