1// SPDX-License-Identifier: GPL-2.0
2// ISHTP interface for ChromeOS Embedded Controller
3//
4// Copyright (c) 2019, Intel Corporation.
5//
6// ISHTP client driver for talking to the Chrome OS EC firmware running
7// on Intel Integrated Sensor Hub (ISH) using the ISH Transport protocol
8// (ISH-TP).
9
10#include <linux/delay.h>
11#include <linux/module.h>
12#include <linux/pci.h>
13#include <linux/platform_data/cros_ec_commands.h>
14#include <linux/platform_data/cros_ec_proto.h>
15#include <linux/intel-ish-client-if.h>
16
17#include "cros_ec.h"
18
19/*
20 * ISH TX/RX ring buffer pool size
21 *
22 * The AP->ISH messages and corresponding ISH->AP responses are
23 * serialized. We need 1 TX and 1 RX buffer for these.
24 *
25 * The MKBP ISH->AP events are serialized. We need one additional RX
26 * buffer for them.
27 */
28#define CROS_ISH_CL_TX_RING_SIZE 8
29#define CROS_ISH_CL_RX_RING_SIZE 8
30
31/* ISH CrOS EC Host Commands */
32enum cros_ec_ish_channel {
33 CROS_EC_COMMAND = 1, /* AP->ISH message */
34 CROS_MKBP_EVENT = 2, /* ISH->AP events */
35};
36
37/*
38 * ISH firmware timeout for 1 message send failure is 1Hz, and the
39 * firmware will retry 2 times, so 3Hz is used for timeout.
40 */
41#define ISHTP_SEND_TIMEOUT (3 * HZ)
42
43/* ISH Transport CrOS EC ISH client unique GUID */
44static const struct ishtp_device_id cros_ec_ishtp_id_table[] = {
45 { .guid = GUID_INIT(0x7b7154d0, 0x56f4, 0x4bdc,
46 0xb0, 0xd8, 0x9e, 0x7c, 0xda, 0xe0, 0xd6, 0xa0), },
47 { }
48};
49MODULE_DEVICE_TABLE(ishtp, cros_ec_ishtp_id_table);
50
51struct header {
52 u8 channel;
53 u8 status;
54 u8 token;
55 u8 reserved;
56} __packed;
57
58struct cros_ish_out_msg {
59 struct header hdr;
60 struct ec_host_request ec_request;
61} __packed;
62
63struct cros_ish_in_msg {
64 struct header hdr;
65 struct ec_host_response ec_response;
66} __packed;
67
68#define IN_MSG_EC_RESPONSE_PREAMBLE \
69 offsetof(struct cros_ish_in_msg, ec_response)
70
71#define OUT_MSG_EC_REQUEST_PREAMBLE \
72 offsetof(struct cros_ish_out_msg, ec_request)
73
74#define cl_data_to_dev(client_data) ishtp_device((client_data)->cl_device)
75
76/*
77 * The Read-Write Semaphore is used to prevent message TX or RX while
78 * the ishtp client is being initialized or undergoing reset.
79 *
80 * The readers are the kernel function calls responsible for IA->ISH
81 * and ISH->AP messaging.
82 *
83 * The writers are .reset() and .probe() function.
84 */
85static DECLARE_RWSEM(init_lock);
86
87/**
88 * struct response_info - Encapsulate firmware response related
89 * information for passing between function ish_send() and
90 * process_recv() callback.
91 *
92 * @data: Copy the data received from firmware here.
93 * @max_size: Max size allocated for the @data buffer. If the received
94 * data exceeds this value, we log an error.
95 * @size: Actual size of data received from firmware.
96 * @error: 0 for success, negative error code for a failure in process_recv().
97 * @token: Expected token for response that we are waiting on.
98 * @received: Set to true on receiving a valid firmware response to host command
99 * @wait_queue: Wait queue for host to wait for firmware response.
100 */
101struct response_info {
102 void *data;
103 size_t max_size;
104 size_t size;
105 int error;
106 u8 token;
107 bool received;
108 wait_queue_head_t wait_queue;
109};
110
111/**
112 * struct ishtp_cl_data - Encapsulate per ISH TP Client.
113 *
114 * @cros_ish_cl: ISHTP firmware client instance.
115 * @cl_device: ISHTP client device instance.
116 * @response: Response info passing between ish_send() and process_recv().
117 * @work_ishtp_reset: Work queue reset handling.
118 * @work_ec_evt: Work queue for EC events.
119 * @ec_dev: CrOS EC MFD device.
120 *
121 * This structure is used to store per client data.
122 */
123struct ishtp_cl_data {
124 struct ishtp_cl *cros_ish_cl;
125 struct ishtp_cl_device *cl_device;
126
127 /*
128 * Used for passing firmware response information between
129 * ish_send() and process_recv() callback.
130 */
131 struct response_info response;
132
133 struct work_struct work_ishtp_reset;
134 struct work_struct work_ec_evt;
135 struct cros_ec_device *ec_dev;
136};
137
138/**
139 * ish_evt_handler - ISH to AP event handler
140 * @work: Work struct
141 */
142static void ish_evt_handler(struct work_struct *work)
143{
144 struct ishtp_cl_data *client_data =
145 container_of(work, struct ishtp_cl_data, work_ec_evt);
146
147 cros_ec_irq_thread(irq: 0, data: client_data->ec_dev);
148}
149
150/**
151 * ish_send() - Send message from host to firmware
152 *
153 * @client_data: Client data instance
154 * @out_msg: Message buffer to be sent to firmware
155 * @out_size: Size of out going message
156 * @in_msg: Message buffer where the incoming data is copied. This buffer
157 * is allocated by calling
158 * @in_size: Max size of incoming message
159 *
160 * Return: Number of bytes copied in the in_msg on success, negative
161 * error code on failure.
162 */
163static int ish_send(struct ishtp_cl_data *client_data,
164 u8 *out_msg, size_t out_size,
165 u8 *in_msg, size_t in_size)
166{
167 static u8 next_token;
168 int rv;
169 struct header *out_hdr = (struct header *)out_msg;
170 struct ishtp_cl *cros_ish_cl = client_data->cros_ish_cl;
171
172 dev_dbg(cl_data_to_dev(client_data),
173 "%s: channel=%02u status=%02u\n",
174 __func__, out_hdr->channel, out_hdr->status);
175
176 /* Setup for incoming response */
177 client_data->response.data = in_msg;
178 client_data->response.max_size = in_size;
179 client_data->response.error = 0;
180 client_data->response.token = next_token++;
181 client_data->response.received = false;
182
183 out_hdr->token = client_data->response.token;
184
185 rv = ishtp_cl_send(cl: cros_ish_cl, buf: out_msg, length: out_size);
186 if (rv) {
187 dev_err(cl_data_to_dev(client_data),
188 "ishtp_cl_send error %d\n", rv);
189 return rv;
190 }
191
192 wait_event_interruptible_timeout(client_data->response.wait_queue,
193 client_data->response.received,
194 ISHTP_SEND_TIMEOUT);
195 if (!client_data->response.received) {
196 dev_err(cl_data_to_dev(client_data),
197 "Timed out for response to host message\n");
198 return -ETIMEDOUT;
199 }
200
201 if (client_data->response.error < 0)
202 return client_data->response.error;
203
204 return client_data->response.size;
205}
206
207/**
208 * process_recv() - Received and parse incoming packet
209 * @cros_ish_cl: Client instance to get stats
210 * @rb_in_proc: Host interface message buffer
211 * @timestamp: Timestamp of when parent callback started
212 *
213 * Parse the incoming packet. If it is a response packet then it will
214 * update per instance flags and wake up the caller waiting to for the
215 * response. If it is an event packet then it will schedule event work.
216 */
217static void process_recv(struct ishtp_cl *cros_ish_cl,
218 struct ishtp_cl_rb *rb_in_proc, ktime_t timestamp)
219{
220 size_t data_len = rb_in_proc->buf_idx;
221 struct ishtp_cl_data *client_data =
222 ishtp_get_client_data(cl: cros_ish_cl);
223 struct device *dev = cl_data_to_dev(client_data);
224 struct cros_ish_in_msg *in_msg =
225 (struct cros_ish_in_msg *)rb_in_proc->buffer.data;
226
227 /* Proceed only if reset or init is not in progress */
228 if (!down_read_trylock(sem: &init_lock)) {
229 /* Free the buffer */
230 ishtp_cl_io_rb_recycle(rb: rb_in_proc);
231 dev_warn(dev,
232 "Host is not ready to receive incoming messages\n");
233 return;
234 }
235
236 /*
237 * All firmware messages contain a header. Check the buffer size
238 * before accessing elements inside.
239 */
240 if (!rb_in_proc->buffer.data) {
241 dev_warn(dev, "rb_in_proc->buffer.data returned null");
242 client_data->response.error = -EBADMSG;
243 goto end_error;
244 }
245
246 if (data_len < sizeof(struct header)) {
247 dev_err(dev, "data size %zu is less than header %zu\n",
248 data_len, sizeof(struct header));
249 client_data->response.error = -EMSGSIZE;
250 goto end_error;
251 }
252
253 dev_dbg(dev, "channel=%02u status=%02u\n",
254 in_msg->hdr.channel, in_msg->hdr.status);
255
256 switch (in_msg->hdr.channel) {
257 case CROS_EC_COMMAND:
258 if (client_data->response.received) {
259 dev_err(dev,
260 "Previous firmware message not yet processed\n");
261 goto end_error;
262 }
263
264 if (client_data->response.token != in_msg->hdr.token) {
265 dev_err_ratelimited(dev,
266 "Dropping old response token %d\n",
267 in_msg->hdr.token);
268 goto end_error;
269 }
270
271 /* Sanity check */
272 if (!client_data->response.data) {
273 dev_err(dev,
274 "Receiving buffer is null. Should be allocated by calling function\n");
275 client_data->response.error = -EINVAL;
276 goto error_wake_up;
277 }
278
279 if (data_len > client_data->response.max_size) {
280 dev_err(dev,
281 "Received buffer size %zu is larger than allocated buffer %zu\n",
282 data_len, client_data->response.max_size);
283 client_data->response.error = -EMSGSIZE;
284 goto error_wake_up;
285 }
286
287 if (in_msg->hdr.status) {
288 dev_err(dev, "firmware returned status %d\n",
289 in_msg->hdr.status);
290 client_data->response.error = -EIO;
291 goto error_wake_up;
292 }
293
294 /* Update the actual received buffer size */
295 client_data->response.size = data_len;
296
297 /*
298 * Copy the buffer received in firmware response for the
299 * calling thread.
300 */
301 memcpy(client_data->response.data,
302 rb_in_proc->buffer.data, data_len);
303
304error_wake_up:
305 /* Free the buffer since we copied data or didn't need it */
306 ishtp_cl_io_rb_recycle(rb: rb_in_proc);
307 rb_in_proc = NULL;
308
309 /* Set flag before waking up the caller */
310 client_data->response.received = true;
311
312 /* Wake the calling thread */
313 wake_up_interruptible(&client_data->response.wait_queue);
314
315 break;
316
317 case CROS_MKBP_EVENT:
318 /* Free the buffer. This is just an event without data */
319 ishtp_cl_io_rb_recycle(rb: rb_in_proc);
320 rb_in_proc = NULL;
321 /*
322 * Set timestamp from beginning of function since we actually
323 * got an incoming MKBP event
324 */
325 client_data->ec_dev->last_event_time = timestamp;
326 schedule_work(work: &client_data->work_ec_evt);
327
328 break;
329
330 default:
331 dev_err(dev, "Invalid channel=%02d\n", in_msg->hdr.channel);
332 }
333
334end_error:
335 /* Free the buffer if we already haven't */
336 if (rb_in_proc)
337 ishtp_cl_io_rb_recycle(rb: rb_in_proc);
338
339 up_read(sem: &init_lock);
340}
341
342/**
343 * ish_event_cb() - bus driver callback for incoming message
344 * @cl_device: ISHTP client device for which this message is targeted.
345 *
346 * Remove the packet from the list and process the message by calling
347 * process_recv.
348 */
349static void ish_event_cb(struct ishtp_cl_device *cl_device)
350{
351 struct ishtp_cl_rb *rb_in_proc;
352 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
353 ktime_t timestamp;
354
355 /*
356 * Take timestamp as close to hardware interrupt as possible for sensor
357 * timestamps.
358 */
359 timestamp = cros_ec_get_time_ns();
360
361 while ((rb_in_proc = ishtp_cl_rx_get_rb(cl: cros_ish_cl)) != NULL) {
362 /* Decide what to do with received data */
363 process_recv(cros_ish_cl, rb_in_proc, timestamp);
364 }
365}
366
367/**
368 * cros_ish_init() - Init function for ISHTP client
369 * @cros_ish_cl: ISHTP client instance
370 * @reset: true if called from reset handler
371 *
372 * This function complete the initializtion of the client.
373 *
374 * Return: 0 for success, negative error code for failure.
375 */
376static int cros_ish_init(struct ishtp_cl *cros_ish_cl, bool reset)
377{
378 int rv;
379 struct ishtp_cl_data *client_data = ishtp_get_client_data(cl: cros_ish_cl);
380
381 rv = ishtp_cl_establish_connection(cl: cros_ish_cl,
382 uuid: &cros_ec_ishtp_id_table[0].guid,
383 CROS_ISH_CL_TX_RING_SIZE,
384 CROS_ISH_CL_RX_RING_SIZE,
385 reset);
386 if (rv) {
387 dev_err(cl_data_to_dev(client_data),
388 "client connect fail\n");
389 goto err_cl_disconnect;
390 }
391
392 ishtp_register_event_cb(device: client_data->cl_device, read_cb: ish_event_cb);
393 return 0;
394
395err_cl_disconnect:
396 ishtp_cl_destroy_connection(cl: cros_ish_cl, reset);
397 return rv;
398}
399
400/**
401 * cros_ish_deinit() - Deinit function for ISHTP client
402 * @cros_ish_cl: ISHTP client instance
403 *
404 * Unlink and free cros_ec client
405 */
406static void cros_ish_deinit(struct ishtp_cl *cros_ish_cl)
407{
408 ishtp_cl_destroy_connection(cl: cros_ish_cl, reset: false);
409
410 /* Disband and free all Tx and Rx client-level rings */
411 ishtp_cl_free(cl: cros_ish_cl);
412}
413
414/**
415 * prepare_cros_ec_rx() - Check & prepare receive buffer
416 * @ec_dev: CrOS EC MFD device.
417 * @in_msg: Incoming message buffer
418 * @msg: cros_ec command used to send & receive data
419 *
420 * Return: 0 for success, negative error code for failure.
421 *
422 * Check the received buffer. Convert to cros_ec_command format.
423 */
424static int prepare_cros_ec_rx(struct cros_ec_device *ec_dev,
425 const struct cros_ish_in_msg *in_msg,
426 struct cros_ec_command *msg)
427{
428 u8 sum = 0;
429 int i, rv, offset;
430
431 /* Check response error code */
432 msg->result = in_msg->ec_response.result;
433 rv = cros_ec_check_result(ec_dev, msg);
434 if (rv < 0)
435 return rv;
436
437 if (in_msg->ec_response.data_len > msg->insize) {
438 dev_err(ec_dev->dev, "Packet too long (%d bytes, expected %d)",
439 in_msg->ec_response.data_len, msg->insize);
440 return -ENOSPC;
441 }
442
443 /* Copy response packet payload and compute checksum */
444 for (i = 0; i < sizeof(struct ec_host_response); i++)
445 sum += ((u8 *)in_msg)[IN_MSG_EC_RESPONSE_PREAMBLE + i];
446
447 offset = sizeof(struct cros_ish_in_msg);
448 for (i = 0; i < in_msg->ec_response.data_len; i++)
449 sum += msg->data[i] = ((u8 *)in_msg)[offset + i];
450
451 if (sum) {
452 dev_dbg(ec_dev->dev, "Bad received packet checksum %d\n", sum);
453 return -EBADMSG;
454 }
455
456 return 0;
457}
458
459static int cros_ec_pkt_xfer_ish(struct cros_ec_device *ec_dev,
460 struct cros_ec_command *msg)
461{
462 int rv;
463 struct ishtp_cl *cros_ish_cl = ec_dev->priv;
464 struct ishtp_cl_data *client_data = ishtp_get_client_data(cl: cros_ish_cl);
465 struct device *dev = cl_data_to_dev(client_data);
466 struct cros_ish_in_msg *in_msg = (struct cros_ish_in_msg *)ec_dev->din;
467 struct cros_ish_out_msg *out_msg =
468 (struct cros_ish_out_msg *)ec_dev->dout;
469 size_t in_size = sizeof(struct cros_ish_in_msg) + msg->insize;
470 size_t out_size = sizeof(struct cros_ish_out_msg) + msg->outsize;
471
472 /* Sanity checks */
473 if (in_size > ec_dev->din_size) {
474 dev_err(dev,
475 "Incoming payload size %zu is too large for ec_dev->din_size %d\n",
476 in_size, ec_dev->din_size);
477 return -EMSGSIZE;
478 }
479
480 if (out_size > ec_dev->dout_size) {
481 dev_err(dev,
482 "Outgoing payload size %zu is too large for ec_dev->dout_size %d\n",
483 out_size, ec_dev->dout_size);
484 return -EMSGSIZE;
485 }
486
487 /* Proceed only if reset-init is not in progress */
488 if (!down_read_trylock(sem: &init_lock)) {
489 dev_warn(dev,
490 "Host is not ready to send messages to ISH. Try again\n");
491 return -EAGAIN;
492 }
493
494 /* Prepare the package to be sent over ISH TP */
495 out_msg->hdr.channel = CROS_EC_COMMAND;
496 out_msg->hdr.status = 0;
497
498 ec_dev->dout += OUT_MSG_EC_REQUEST_PREAMBLE;
499 rv = cros_ec_prepare_tx(ec_dev, msg);
500 if (rv < 0)
501 goto end_error;
502 ec_dev->dout -= OUT_MSG_EC_REQUEST_PREAMBLE;
503
504 dev_dbg(dev,
505 "out_msg: struct_ver=0x%x checksum=0x%x command=0x%x command_ver=0x%x data_len=0x%x\n",
506 out_msg->ec_request.struct_version,
507 out_msg->ec_request.checksum,
508 out_msg->ec_request.command,
509 out_msg->ec_request.command_version,
510 out_msg->ec_request.data_len);
511
512 /* Send command to ISH EC firmware and read response */
513 rv = ish_send(client_data,
514 out_msg: (u8 *)out_msg, out_size,
515 in_msg: (u8 *)in_msg, in_size);
516 if (rv < 0)
517 goto end_error;
518
519 rv = prepare_cros_ec_rx(ec_dev, in_msg, msg);
520 if (rv)
521 goto end_error;
522
523 rv = in_msg->ec_response.data_len;
524
525 dev_dbg(dev,
526 "in_msg: struct_ver=0x%x checksum=0x%x result=0x%x data_len=0x%x\n",
527 in_msg->ec_response.struct_version,
528 in_msg->ec_response.checksum,
529 in_msg->ec_response.result,
530 in_msg->ec_response.data_len);
531
532end_error:
533 if (msg->command == EC_CMD_REBOOT_EC)
534 msleep(EC_REBOOT_DELAY_MS);
535
536 up_read(sem: &init_lock);
537
538 return rv;
539}
540
541static int cros_ec_dev_init(struct ishtp_cl_data *client_data)
542{
543 struct cros_ec_device *ec_dev;
544 struct device *dev = cl_data_to_dev(client_data);
545
546 ec_dev = cros_ec_device_alloc(dev);
547 if (!ec_dev)
548 return -ENOMEM;
549
550 client_data->ec_dev = ec_dev;
551 dev->driver_data = ec_dev;
552
553 ec_dev->priv = client_data->cros_ish_cl;
554 ec_dev->cmd_xfer = NULL;
555 ec_dev->pkt_xfer = cros_ec_pkt_xfer_ish;
556 ec_dev->phys_name = dev_name(dev);
557
558 return cros_ec_register(ec_dev);
559}
560
561static void reset_handler(struct work_struct *work)
562{
563 int rv;
564 struct device *dev;
565 struct ishtp_cl *cros_ish_cl;
566 struct ishtp_cl_data *client_data =
567 container_of(work, struct ishtp_cl_data, work_ishtp_reset);
568
569 /* Lock for reset to complete */
570 down_write(sem: &init_lock);
571
572 cros_ish_cl = client_data->cros_ish_cl;
573
574 ishtp_cl_destroy_connection(cl: cros_ish_cl, reset: true);
575
576 rv = cros_ish_init(cros_ish_cl, reset: true);
577 if (rv) {
578 dev_err(cl_data_to_dev(client_data), "Reset Failed\n");
579 up_write(sem: &init_lock);
580 return;
581 }
582
583 /* Refresh ec_dev device pointers */
584 client_data->ec_dev->priv = client_data->cros_ish_cl;
585 dev = cl_data_to_dev(client_data);
586 dev->driver_data = client_data->ec_dev;
587
588 dev_info(cl_data_to_dev(client_data), "Chrome EC ISH reset done\n");
589
590 up_write(sem: &init_lock);
591}
592
593/**
594 * cros_ec_ishtp_probe() - ISHTP client driver probe callback
595 * @cl_device: ISHTP client device instance
596 *
597 * Return: 0 for success, negative error code for failure.
598 */
599static int cros_ec_ishtp_probe(struct ishtp_cl_device *cl_device)
600{
601 int rv;
602 struct ishtp_cl *cros_ish_cl;
603 struct ishtp_cl_data *client_data =
604 devm_kzalloc(dev: ishtp_device(cl_device),
605 size: sizeof(*client_data), GFP_KERNEL);
606 if (!client_data)
607 return -ENOMEM;
608
609 /* Lock for initialization to complete */
610 down_write(sem: &init_lock);
611
612 cros_ish_cl = ishtp_cl_allocate(cl_device);
613 if (!cros_ish_cl) {
614 rv = -ENOMEM;
615 goto end_ishtp_cl_alloc_error;
616 }
617
618 ishtp_set_drvdata(cl_device, data: cros_ish_cl);
619 ishtp_set_client_data(cl: cros_ish_cl, data: client_data);
620 client_data->cros_ish_cl = cros_ish_cl;
621 client_data->cl_device = cl_device;
622
623 init_waitqueue_head(&client_data->response.wait_queue);
624
625 INIT_WORK(&client_data->work_ishtp_reset,
626 reset_handler);
627 INIT_WORK(&client_data->work_ec_evt,
628 ish_evt_handler);
629
630 rv = cros_ish_init(cros_ish_cl, reset: false);
631 if (rv)
632 goto end_ishtp_cl_init_error;
633
634 ishtp_get_device(cl_dev: cl_device);
635
636 up_write(sem: &init_lock);
637
638 /* Register croc_ec_dev mfd */
639 rv = cros_ec_dev_init(client_data);
640 if (rv) {
641 down_write(sem: &init_lock);
642 goto end_cros_ec_dev_init_error;
643 }
644
645 return 0;
646
647end_cros_ec_dev_init_error:
648 ishtp_cl_destroy_connection(cl: cros_ish_cl, reset: false);
649 ishtp_put_device(cl_dev: cl_device);
650end_ishtp_cl_init_error:
651 ishtp_cl_free(cl: cros_ish_cl);
652end_ishtp_cl_alloc_error:
653 up_write(sem: &init_lock);
654 return rv;
655}
656
657/**
658 * cros_ec_ishtp_remove() - ISHTP client driver remove callback
659 * @cl_device: ISHTP client device instance
660 *
661 * Return: 0
662 */
663static void cros_ec_ishtp_remove(struct ishtp_cl_device *cl_device)
664{
665 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
666 struct ishtp_cl_data *client_data = ishtp_get_client_data(cl: cros_ish_cl);
667
668 cancel_work_sync(work: &client_data->work_ishtp_reset);
669 cancel_work_sync(work: &client_data->work_ec_evt);
670 cros_ec_unregister(ec_dev: client_data->ec_dev);
671 cros_ish_deinit(cros_ish_cl);
672 ishtp_put_device(cl_dev: cl_device);
673}
674
675/**
676 * cros_ec_ishtp_reset() - ISHTP client driver reset callback
677 * @cl_device: ISHTP client device instance
678 *
679 * Return: 0
680 */
681static int cros_ec_ishtp_reset(struct ishtp_cl_device *cl_device)
682{
683 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
684 struct ishtp_cl_data *client_data = ishtp_get_client_data(cl: cros_ish_cl);
685
686 schedule_work(work: &client_data->work_ishtp_reset);
687
688 return 0;
689}
690
691/**
692 * cros_ec_ishtp_suspend() - ISHTP client driver suspend callback
693 * @device: device instance
694 *
695 * Return: 0 for success, negative error code for failure.
696 */
697static int __maybe_unused cros_ec_ishtp_suspend(struct device *device)
698{
699 struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(dev: device);
700 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
701 struct ishtp_cl_data *client_data = ishtp_get_client_data(cl: cros_ish_cl);
702
703 return cros_ec_suspend(ec_dev: client_data->ec_dev);
704}
705
706/**
707 * cros_ec_ishtp_resume() - ISHTP client driver resume callback
708 * @device: device instance
709 *
710 * Return: 0 for success, negative error code for failure.
711 */
712static int __maybe_unused cros_ec_ishtp_resume(struct device *device)
713{
714 struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(dev: device);
715 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
716 struct ishtp_cl_data *client_data = ishtp_get_client_data(cl: cros_ish_cl);
717
718 return cros_ec_resume(ec_dev: client_data->ec_dev);
719}
720
721static SIMPLE_DEV_PM_OPS(cros_ec_ishtp_pm_ops, cros_ec_ishtp_suspend,
722 cros_ec_ishtp_resume);
723
724static struct ishtp_cl_driver cros_ec_ishtp_driver = {
725 .name = "cros_ec_ishtp",
726 .id = cros_ec_ishtp_id_table,
727 .probe = cros_ec_ishtp_probe,
728 .remove = cros_ec_ishtp_remove,
729 .reset = cros_ec_ishtp_reset,
730 .driver = {
731 .pm = &cros_ec_ishtp_pm_ops,
732 },
733};
734
735static int __init cros_ec_ishtp_mod_init(void)
736{
737 return ishtp_cl_driver_register(driver: &cros_ec_ishtp_driver, THIS_MODULE);
738}
739
740static void __exit cros_ec_ishtp_mod_exit(void)
741{
742 ishtp_cl_driver_unregister(driver: &cros_ec_ishtp_driver);
743}
744
745module_init(cros_ec_ishtp_mod_init);
746module_exit(cros_ec_ishtp_mod_exit);
747
748MODULE_DESCRIPTION("ChromeOS EC ISHTP Client Driver");
749MODULE_AUTHOR("Rushikesh S Kadam <rushikesh.s.kadam@intel.com>");
750
751MODULE_LICENSE("GPL v2");
752

source code of linux/drivers/platform/chrome/cros_ec_ishtp.c