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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 guid_t cros_ish_guid =
45 GUID_INIT(0x7b7154d0, 0x56f4, 0x4bdc,
46 0xb0, 0xd8, 0x9e, 0x7c, 0xda, 0xe0, 0xd6, 0xa0);
47
48struct header {
49 u8 channel;
50 u8 status;
51 u8 token;
52 u8 reserved;
53} __packed;
54
55struct cros_ish_out_msg {
56 struct header hdr;
57 struct ec_host_request ec_request;
58} __packed;
59
60struct cros_ish_in_msg {
61 struct header hdr;
62 struct ec_host_response ec_response;
63} __packed;
64
65#define IN_MSG_EC_RESPONSE_PREAMBLE \
66 offsetof(struct cros_ish_in_msg, ec_response)
67
68#define OUT_MSG_EC_REQUEST_PREAMBLE \
69 offsetof(struct cros_ish_out_msg, ec_request)
70
71#define cl_data_to_dev(client_data) ishtp_device((client_data)->cl_device)
72
73/*
74 * The Read-Write Semaphore is used to prevent message TX or RX while
75 * the ishtp client is being initialized or undergoing reset.
76 *
77 * The readers are the kernel function calls responsible for IA->ISH
78 * and ISH->AP messaging.
79 *
80 * The writers are .reset() and .probe() function.
81 */
82static DECLARE_RWSEM(init_lock);
83
84/**
85 * struct response_info - Encapsulate firmware response related
86 * information for passing between function ish_send() and
87 * process_recv() callback.
88 *
89 * @data: Copy the data received from firmware here.
90 * @max_size: Max size allocated for the @data buffer. If the received
91 * data exceeds this value, we log an error.
92 * @size: Actual size of data received from firmware.
93 * @error: 0 for success, negative error code for a failure in process_recv().
94 * @token: Expected token for response that we are waiting on.
95 * @received: Set to true on receiving a valid firmware response to host command
96 * @wait_queue: Wait queue for host to wait for firmware response.
97 */
98struct response_info {
99 void *data;
100 size_t max_size;
101 size_t size;
102 int error;
103 u8 token;
104 bool received;
105 wait_queue_head_t wait_queue;
106};
107
108/**
109 * struct ishtp_cl_data - Encapsulate per ISH TP Client.
110 *
111 * @cros_ish_cl: ISHTP firmware client instance.
112 * @cl_device: ISHTP client device instance.
113 * @response: Response info passing between ish_send() and process_recv().
114 * @work_ishtp_reset: Work queue reset handling.
115 * @work_ec_evt: Work queue for EC events.
116 * @ec_dev: CrOS EC MFD device.
117 *
118 * This structure is used to store per client data.
119 */
120struct ishtp_cl_data {
121 struct ishtp_cl *cros_ish_cl;
122 struct ishtp_cl_device *cl_device;
123
124 /*
125 * Used for passing firmware response information between
126 * ish_send() and process_recv() callback.
127 */
128 struct response_info response;
129
130 struct work_struct work_ishtp_reset;
131 struct work_struct work_ec_evt;
132 struct cros_ec_device *ec_dev;
133};
134
135/**
136 * ish_evt_handler - ISH to AP event handler
137 * @work: Work struct
138 */
139static void ish_evt_handler(struct work_struct *work)
140{
141 struct ishtp_cl_data *client_data =
142 container_of(work, struct ishtp_cl_data, work_ec_evt);
143 struct cros_ec_device *ec_dev = client_data->ec_dev;
144 bool ec_has_more_events;
145
146 do {
147 ec_has_more_events = cros_ec_handle_event(ec_dev);
148 } while (ec_has_more_events);
149}
150
151/**
152 * ish_send() - Send message from host to firmware
153 *
154 * @client_data: Client data instance
155 * @out_msg: Message buffer to be sent to firmware
156 * @out_size: Size of out going message
157 * @in_msg: Message buffer where the incoming data is copied. This buffer
158 * is allocated by calling
159 * @in_size: Max size of incoming message
160 *
161 * Return: Number of bytes copied in the in_msg on success, negative
162 * error code on failure.
163 */
164static int ish_send(struct ishtp_cl_data *client_data,
165 u8 *out_msg, size_t out_size,
166 u8 *in_msg, size_t in_size)
167{
168 static u8 next_token;
169 int rv;
170 struct header *out_hdr = (struct header *)out_msg;
171 struct ishtp_cl *cros_ish_cl = client_data->cros_ish_cl;
172
173 dev_dbg(cl_data_to_dev(client_data),
174 "%s: channel=%02u status=%02u\n",
175 __func__, out_hdr->channel, out_hdr->status);
176
177 /* Setup for incoming response */
178 client_data->response.data = in_msg;
179 client_data->response.max_size = in_size;
180 client_data->response.error = 0;
181 client_data->response.token = next_token++;
182 client_data->response.received = false;
183
184 out_hdr->token = client_data->response.token;
185
186 rv = ishtp_cl_send(cros_ish_cl, out_msg, out_size);
187 if (rv) {
188 dev_err(cl_data_to_dev(client_data),
189 "ishtp_cl_send error %d\n", rv);
190 return rv;
191 }
192
193 wait_event_interruptible_timeout(client_data->response.wait_queue,
194 client_data->response.received,
195 ISHTP_SEND_TIMEOUT);
196 if (!client_data->response.received) {
197 dev_err(cl_data_to_dev(client_data),
198 "Timed out for response to host message\n");
199 return -ETIMEDOUT;
200 }
201
202 if (client_data->response.error < 0)
203 return client_data->response.error;
204
205 return client_data->response.size;
206}
207
208/**
209 * process_recv() - Received and parse incoming packet
210 * @cros_ish_cl: Client instance to get stats
211 * @rb_in_proc: Host interface message buffer
212 * @timestamp: Timestamp of when parent callback started
213 *
214 * Parse the incoming packet. If it is a response packet then it will
215 * update per instance flags and wake up the caller waiting to for the
216 * response. If it is an event packet then it will schedule event work.
217 */
218static void process_recv(struct ishtp_cl *cros_ish_cl,
219 struct ishtp_cl_rb *rb_in_proc, ktime_t timestamp)
220{
221 size_t data_len = rb_in_proc->buf_idx;
222 struct ishtp_cl_data *client_data =
223 ishtp_get_client_data(cros_ish_cl);
224 struct device *dev = cl_data_to_dev(client_data);
225 struct cros_ish_in_msg *in_msg =
226 (struct cros_ish_in_msg *)rb_in_proc->buffer.data;
227
228 /* Proceed only if reset or init is not in progress */
229 if (!down_read_trylock(&init_lock)) {
230 /* Free the buffer */
231 ishtp_cl_io_rb_recycle(rb_in_proc);
232 dev_warn(dev,
233 "Host is not ready to receive incoming messages\n");
234 return;
235 }
236
237 /*
238 * All firmware messages contain a header. Check the buffer size
239 * before accessing elements inside.
240 */
241 if (!rb_in_proc->buffer.data) {
242 dev_warn(dev, "rb_in_proc->buffer.data returned null");
243 client_data->response.error = -EBADMSG;
244 goto end_error;
245 }
246
247 if (data_len < sizeof(struct header)) {
248 dev_err(dev, "data size %zu is less than header %zu\n",
249 data_len, sizeof(struct header));
250 client_data->response.error = -EMSGSIZE;
251 goto end_error;
252 }
253
254 dev_dbg(dev, "channel=%02u status=%02u\n",
255 in_msg->hdr.channel, in_msg->hdr.status);
256
257 switch (in_msg->hdr.channel) {
258 case CROS_EC_COMMAND:
259 if (client_data->response.received) {
260 dev_err(dev,
261 "Previous firmware message not yet processed\n");
262 goto end_error;
263 }
264
265 if (client_data->response.token != in_msg->hdr.token) {
266 dev_err_ratelimited(dev,
267 "Dropping old response token %d\n",
268 in_msg->hdr.token);
269 goto end_error;
270 }
271
272 /* Sanity check */
273 if (!client_data->response.data) {
274 dev_err(dev,
275 "Receiving buffer is null. Should be allocated by calling function\n");
276 client_data->response.error = -EINVAL;
277 goto error_wake_up;
278 }
279
280 if (data_len > client_data->response.max_size) {
281 dev_err(dev,
282 "Received buffer size %zu is larger than allocated buffer %zu\n",
283 data_len, client_data->response.max_size);
284 client_data->response.error = -EMSGSIZE;
285 goto error_wake_up;
286 }
287
288 if (in_msg->hdr.status) {
289 dev_err(dev, "firmware returned status %d\n",
290 in_msg->hdr.status);
291 client_data->response.error = -EIO;
292 goto error_wake_up;
293 }
294
295 /* Update the actual received buffer size */
296 client_data->response.size = data_len;
297
298 /*
299 * Copy the buffer received in firmware response for the
300 * calling thread.
301 */
302 memcpy(client_data->response.data,
303 rb_in_proc->buffer.data, data_len);
304
305error_wake_up:
306 /* Free the buffer since we copied data or didn't need it */
307 ishtp_cl_io_rb_recycle(rb_in_proc);
308 rb_in_proc = NULL;
309
310 /* Set flag before waking up the caller */
311 client_data->response.received = true;
312
313 /* Wake the calling thread */
314 wake_up_interruptible(&client_data->response.wait_queue);
315
316 break;
317
318 case CROS_MKBP_EVENT:
319 /* Free the buffer. This is just an event without data */
320 ishtp_cl_io_rb_recycle(rb_in_proc);
321 rb_in_proc = NULL;
322 /*
323 * Set timestamp from beginning of function since we actually
324 * got an incoming MKBP event
325 */
326 client_data->ec_dev->last_event_time = timestamp;
327 schedule_work(&client_data->work_ec_evt);
328
329 break;
330
331 default:
332 dev_err(dev, "Invalid channel=%02d\n", in_msg->hdr.channel);
333 }
334
335end_error:
336 /* Free the buffer if we already haven't */
337 if (rb_in_proc)
338 ishtp_cl_io_rb_recycle(rb_in_proc);
339
340 up_read(&init_lock);
341}
342
343/**
344 * ish_event_cb() - bus driver callback for incoming message
345 * @cl_device: ISHTP client device for which this message is targeted.
346 *
347 * Remove the packet from the list and process the message by calling
348 * process_recv.
349 */
350static void ish_event_cb(struct ishtp_cl_device *cl_device)
351{
352 struct ishtp_cl_rb *rb_in_proc;
353 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
354 ktime_t timestamp;
355
356 /*
357 * Take timestamp as close to hardware interrupt as possible for sensor
358 * timestamps.
359 */
360 timestamp = cros_ec_get_time_ns();
361
362 while ((rb_in_proc = ishtp_cl_rx_get_rb(cros_ish_cl)) != NULL) {
363 /* Decide what to do with received data */
364 process_recv(cros_ish_cl, rb_in_proc, timestamp);
365 }
366}
367
368/**
369 * cros_ish_init() - Init function for ISHTP client
370 * @cros_ish_cl: ISHTP client instance
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)
377{
378 int rv;
379 struct ishtp_device *dev;
380 struct ishtp_fw_client *fw_client;
381 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
382
383 rv = ishtp_cl_link(cros_ish_cl);
384 if (rv) {
385 dev_err(cl_data_to_dev(client_data),
386 "ishtp_cl_link failed\n");
387 return rv;
388 }
389
390 dev = ishtp_get_ishtp_device(cros_ish_cl);
391
392 /* Connect to firmware client */
393 ishtp_set_tx_ring_size(cros_ish_cl, CROS_ISH_CL_TX_RING_SIZE);
394 ishtp_set_rx_ring_size(cros_ish_cl, CROS_ISH_CL_RX_RING_SIZE);
395
396 fw_client = ishtp_fw_cl_get_client(dev, &cros_ish_guid);
397 if (!fw_client) {
398 dev_err(cl_data_to_dev(client_data),
399 "ish client uuid not found\n");
400 rv = -ENOENT;
401 goto err_cl_unlink;
402 }
403
404 ishtp_cl_set_fw_client_id(cros_ish_cl,
405 ishtp_get_fw_client_id(fw_client));
406 ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_CONNECTING);
407
408 rv = ishtp_cl_connect(cros_ish_cl);
409 if (rv) {
410 dev_err(cl_data_to_dev(client_data),
411 "client connect fail\n");
412 goto err_cl_unlink;
413 }
414
415 ishtp_register_event_cb(client_data->cl_device, ish_event_cb);
416 return 0;
417
418err_cl_unlink:
419 ishtp_cl_unlink(cros_ish_cl);
420 return rv;
421}
422
423/**
424 * cros_ish_deinit() - Deinit function for ISHTP client
425 * @cros_ish_cl: ISHTP client instance
426 *
427 * Unlink and free cros_ec client
428 */
429static void cros_ish_deinit(struct ishtp_cl *cros_ish_cl)
430{
431 ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_DISCONNECTING);
432 ishtp_cl_disconnect(cros_ish_cl);
433 ishtp_cl_unlink(cros_ish_cl);
434 ishtp_cl_flush_queues(cros_ish_cl);
435
436 /* Disband and free all Tx and Rx client-level rings */
437 ishtp_cl_free(cros_ish_cl);
438}
439
440/**
441 * prepare_cros_ec_rx() - Check & prepare receive buffer
442 * @ec_dev: CrOS EC MFD device.
443 * @in_msg: Incoming message buffer
444 * @msg: cros_ec command used to send & receive data
445 *
446 * Return: 0 for success, negative error code for failure.
447 *
448 * Check the received buffer. Convert to cros_ec_command format.
449 */
450static int prepare_cros_ec_rx(struct cros_ec_device *ec_dev,
451 const struct cros_ish_in_msg *in_msg,
452 struct cros_ec_command *msg)
453{
454 u8 sum = 0;
455 int i, rv, offset;
456
457 /* Check response error code */
458 msg->result = in_msg->ec_response.result;
459 rv = cros_ec_check_result(ec_dev, msg);
460 if (rv < 0)
461 return rv;
462
463 if (in_msg->ec_response.data_len > msg->insize) {
464 dev_err(ec_dev->dev, "Packet too long (%d bytes, expected %d)",
465 in_msg->ec_response.data_len, msg->insize);
466 return -ENOSPC;
467 }
468
469 /* Copy response packet payload and compute checksum */
470 for (i = 0; i < sizeof(struct ec_host_response); i++)
471 sum += ((u8 *)in_msg)[IN_MSG_EC_RESPONSE_PREAMBLE + i];
472
473 offset = sizeof(struct cros_ish_in_msg);
474 for (i = 0; i < in_msg->ec_response.data_len; i++)
475 sum += msg->data[i] = ((u8 *)in_msg)[offset + i];
476
477 if (sum) {
478 dev_dbg(ec_dev->dev, "Bad received packet checksum %d\n", sum);
479 return -EBADMSG;
480 }
481
482 return 0;
483}
484
485static int cros_ec_pkt_xfer_ish(struct cros_ec_device *ec_dev,
486 struct cros_ec_command *msg)
487{
488 int rv;
489 struct ishtp_cl *cros_ish_cl = ec_dev->priv;
490 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
491 struct device *dev = cl_data_to_dev(client_data);
492 struct cros_ish_in_msg *in_msg = (struct cros_ish_in_msg *)ec_dev->din;
493 struct cros_ish_out_msg *out_msg =
494 (struct cros_ish_out_msg *)ec_dev->dout;
495 size_t in_size = sizeof(struct cros_ish_in_msg) + msg->insize;
496 size_t out_size = sizeof(struct cros_ish_out_msg) + msg->outsize;
497
498 /* Sanity checks */
499 if (in_size > ec_dev->din_size) {
500 dev_err(dev,
501 "Incoming payload size %zu is too large for ec_dev->din_size %d\n",
502 in_size, ec_dev->din_size);
503 return -EMSGSIZE;
504 }
505
506 if (out_size > ec_dev->dout_size) {
507 dev_err(dev,
508 "Outgoing payload size %zu is too large for ec_dev->dout_size %d\n",
509 out_size, ec_dev->dout_size);
510 return -EMSGSIZE;
511 }
512
513 /* Proceed only if reset-init is not in progress */
514 if (!down_read_trylock(&init_lock)) {
515 dev_warn(dev,
516 "Host is not ready to send messages to ISH. Try again\n");
517 return -EAGAIN;
518 }
519
520 /* Prepare the package to be sent over ISH TP */
521 out_msg->hdr.channel = CROS_EC_COMMAND;
522 out_msg->hdr.status = 0;
523
524 ec_dev->dout += OUT_MSG_EC_REQUEST_PREAMBLE;
525 cros_ec_prepare_tx(ec_dev, msg);
526 ec_dev->dout -= OUT_MSG_EC_REQUEST_PREAMBLE;
527
528 dev_dbg(dev,
529 "out_msg: struct_ver=0x%x checksum=0x%x command=0x%x command_ver=0x%x data_len=0x%x\n",
530 out_msg->ec_request.struct_version,
531 out_msg->ec_request.checksum,
532 out_msg->ec_request.command,
533 out_msg->ec_request.command_version,
534 out_msg->ec_request.data_len);
535
536 /* Send command to ISH EC firmware and read response */
537 rv = ish_send(client_data,
538 (u8 *)out_msg, out_size,
539 (u8 *)in_msg, in_size);
540 if (rv < 0)
541 goto end_error;
542
543 rv = prepare_cros_ec_rx(ec_dev, in_msg, msg);
544 if (rv)
545 goto end_error;
546
547 rv = in_msg->ec_response.data_len;
548
549 dev_dbg(dev,
550 "in_msg: struct_ver=0x%x checksum=0x%x result=0x%x data_len=0x%x\n",
551 in_msg->ec_response.struct_version,
552 in_msg->ec_response.checksum,
553 in_msg->ec_response.result,
554 in_msg->ec_response.data_len);
555
556end_error:
557 if (msg->command == EC_CMD_REBOOT_EC)
558 msleep(EC_REBOOT_DELAY_MS);
559
560 up_read(&init_lock);
561
562 return rv;
563}
564
565static int cros_ec_dev_init(struct ishtp_cl_data *client_data)
566{
567 struct cros_ec_device *ec_dev;
568 struct device *dev = cl_data_to_dev(client_data);
569
570 ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
571 if (!ec_dev)
572 return -ENOMEM;
573
574 client_data->ec_dev = ec_dev;
575 dev->driver_data = ec_dev;
576
577 ec_dev->dev = dev;
578 ec_dev->priv = client_data->cros_ish_cl;
579 ec_dev->cmd_xfer = NULL;
580 ec_dev->pkt_xfer = cros_ec_pkt_xfer_ish;
581 ec_dev->phys_name = dev_name(dev);
582 ec_dev->din_size = sizeof(struct cros_ish_in_msg) +
583 sizeof(struct ec_response_get_protocol_info);
584 ec_dev->dout_size = sizeof(struct cros_ish_out_msg);
585
586 return cros_ec_register(ec_dev);
587}
588
589static void reset_handler(struct work_struct *work)
590{
591 int rv;
592 struct device *dev;
593 struct ishtp_cl *cros_ish_cl;
594 struct ishtp_cl_device *cl_device;
595 struct ishtp_cl_data *client_data =
596 container_of(work, struct ishtp_cl_data, work_ishtp_reset);
597
598 /* Lock for reset to complete */
599 down_write(&init_lock);
600
601 cros_ish_cl = client_data->cros_ish_cl;
602 cl_device = client_data->cl_device;
603
604 /* Unlink, flush queues & start again */
605 ishtp_cl_unlink(cros_ish_cl);
606 ishtp_cl_flush_queues(cros_ish_cl);
607 ishtp_cl_free(cros_ish_cl);
608
609 cros_ish_cl = ishtp_cl_allocate(cl_device);
610 if (!cros_ish_cl) {
611 up_write(&init_lock);
612 return;
613 }
614
615 ishtp_set_drvdata(cl_device, cros_ish_cl);
616 ishtp_set_client_data(cros_ish_cl, client_data);
617 client_data->cros_ish_cl = cros_ish_cl;
618
619 rv = cros_ish_init(cros_ish_cl);
620 if (rv) {
621 ishtp_cl_free(cros_ish_cl);
622 dev_err(cl_data_to_dev(client_data), "Reset Failed\n");
623 up_write(&init_lock);
624 return;
625 }
626
627 /* Refresh ec_dev device pointers */
628 client_data->ec_dev->priv = client_data->cros_ish_cl;
629 dev = cl_data_to_dev(client_data);
630 dev->driver_data = client_data->ec_dev;
631
632 dev_info(cl_data_to_dev(client_data), "Chrome EC ISH reset done\n");
633
634 up_write(&init_lock);
635}
636
637/**
638 * cros_ec_ishtp_probe() - ISHTP client driver probe callback
639 * @cl_device: ISHTP client device instance
640 *
641 * Return: 0 for success, negative error code for failure.
642 */
643static int cros_ec_ishtp_probe(struct ishtp_cl_device *cl_device)
644{
645 int rv;
646 struct ishtp_cl *cros_ish_cl;
647 struct ishtp_cl_data *client_data =
648 devm_kzalloc(ishtp_device(cl_device),
649 sizeof(*client_data), GFP_KERNEL);
650 if (!client_data)
651 return -ENOMEM;
652
653 /* Lock for initialization to complete */
654 down_write(&init_lock);
655
656 cros_ish_cl = ishtp_cl_allocate(cl_device);
657 if (!cros_ish_cl) {
658 rv = -ENOMEM;
659 goto end_ishtp_cl_alloc_error;
660 }
661
662 ishtp_set_drvdata(cl_device, cros_ish_cl);
663 ishtp_set_client_data(cros_ish_cl, client_data);
664 client_data->cros_ish_cl = cros_ish_cl;
665 client_data->cl_device = cl_device;
666
667 init_waitqueue_head(&client_data->response.wait_queue);
668
669 INIT_WORK(&client_data->work_ishtp_reset,
670 reset_handler);
671 INIT_WORK(&client_data->work_ec_evt,
672 ish_evt_handler);
673
674 rv = cros_ish_init(cros_ish_cl);
675 if (rv)
676 goto end_ishtp_cl_init_error;
677
678 ishtp_get_device(cl_device);
679
680 up_write(&init_lock);
681
682 /* Register croc_ec_dev mfd */
683 rv = cros_ec_dev_init(client_data);
684 if (rv) {
685 down_write(&init_lock);
686 goto end_cros_ec_dev_init_error;
687 }
688
689 return 0;
690
691end_cros_ec_dev_init_error:
692 ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_DISCONNECTING);
693 ishtp_cl_disconnect(cros_ish_cl);
694 ishtp_cl_unlink(cros_ish_cl);
695 ishtp_cl_flush_queues(cros_ish_cl);
696 ishtp_put_device(cl_device);
697end_ishtp_cl_init_error:
698 ishtp_cl_free(cros_ish_cl);
699end_ishtp_cl_alloc_error:
700 up_write(&init_lock);
701 return rv;
702}
703
704/**
705 * cros_ec_ishtp_remove() - ISHTP client driver remove callback
706 * @cl_device: ISHTP client device instance
707 *
708 * Return: 0
709 */
710static int cros_ec_ishtp_remove(struct ishtp_cl_device *cl_device)
711{
712 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
713 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
714
715 cancel_work_sync(&client_data->work_ishtp_reset);
716 cancel_work_sync(&client_data->work_ec_evt);
717 cros_ish_deinit(cros_ish_cl);
718 ishtp_put_device(cl_device);
719
720 return 0;
721}
722
723/**
724 * cros_ec_ishtp_reset() - ISHTP client driver reset callback
725 * @cl_device: ISHTP client device instance
726 *
727 * Return: 0
728 */
729static int cros_ec_ishtp_reset(struct ishtp_cl_device *cl_device)
730{
731 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
732 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
733
734 schedule_work(&client_data->work_ishtp_reset);
735
736 return 0;
737}
738
739/**
740 * cros_ec_ishtp_suspend() - ISHTP client driver suspend callback
741 * @device: device instance
742 *
743 * Return: 0 for success, negative error code for failure.
744 */
745static int __maybe_unused cros_ec_ishtp_suspend(struct device *device)
746{
747 struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(device);
748 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
749 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
750
751 return cros_ec_suspend(client_data->ec_dev);
752}
753
754/**
755 * cros_ec_ishtp_resume() - ISHTP client driver resume callback
756 * @device: device instance
757 *
758 * Return: 0 for success, negative error code for failure.
759 */
760static int __maybe_unused cros_ec_ishtp_resume(struct device *device)
761{
762 struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(device);
763 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
764 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
765
766 return cros_ec_resume(client_data->ec_dev);
767}
768
769static SIMPLE_DEV_PM_OPS(cros_ec_ishtp_pm_ops, cros_ec_ishtp_suspend,
770 cros_ec_ishtp_resume);
771
772static struct ishtp_cl_driver cros_ec_ishtp_driver = {
773 .name = "cros_ec_ishtp",
774 .guid = &cros_ish_guid,
775 .probe = cros_ec_ishtp_probe,
776 .remove = cros_ec_ishtp_remove,
777 .reset = cros_ec_ishtp_reset,
778 .driver = {
779 .pm = &cros_ec_ishtp_pm_ops,
780 },
781};
782
783static int __init cros_ec_ishtp_mod_init(void)
784{
785 return ishtp_cl_driver_register(&cros_ec_ishtp_driver, THIS_MODULE);
786}
787
788static void __exit cros_ec_ishtp_mod_exit(void)
789{
790 ishtp_cl_driver_unregister(&cros_ec_ishtp_driver);
791}
792
793module_init(cros_ec_ishtp_mod_init);
794module_exit(cros_ec_ishtp_mod_exit);
795
796MODULE_DESCRIPTION("ChromeOS EC ISHTP Client Driver");
797MODULE_AUTHOR("Rushikesh S Kadam <rushikesh.s.kadam@intel.com>");
798
799MODULE_LICENSE("GPL v2");
800MODULE_ALIAS("ishtp:*");
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/*
18 * ISH TX/RX ring buffer pool size
19 *
20 * The AP->ISH messages and corresponding ISH->AP responses are
21 * serialized. We need 1 TX and 1 RX buffer for these.
22 *
23 * The MKBP ISH->AP events are serialized. We need one additional RX
24 * buffer for them.
25 */
26#define CROS_ISH_CL_TX_RING_SIZE 8
27#define CROS_ISH_CL_RX_RING_SIZE 8
28
29/* ISH CrOS EC Host Commands */
30enum cros_ec_ish_channel {
31 CROS_EC_COMMAND = 1, /* AP->ISH message */
32 CROS_MKBP_EVENT = 2, /* ISH->AP events */
33};
34
35/*
36 * ISH firmware timeout for 1 message send failure is 1Hz, and the
37 * firmware will retry 2 times, so 3Hz is used for timeout.
38 */
39#define ISHTP_SEND_TIMEOUT (3 * HZ)
40
41/* ISH Transport CrOS EC ISH client unique GUID */
42static const guid_t cros_ish_guid =
43 GUID_INIT(0x7b7154d0, 0x56f4, 0x4bdc,
44 0xb0, 0xd8, 0x9e, 0x7c, 0xda, 0xe0, 0xd6, 0xa0);
45
46struct header {
47 u8 channel;
48 u8 status;
49 u8 reserved[2];
50} __packed;
51
52struct cros_ish_out_msg {
53 struct header hdr;
54 struct ec_host_request ec_request;
55} __packed;
56
57struct cros_ish_in_msg {
58 struct header hdr;
59 struct ec_host_response ec_response;
60} __packed;
61
62#define IN_MSG_EC_RESPONSE_PREAMBLE \
63 offsetof(struct cros_ish_in_msg, ec_response)
64
65#define OUT_MSG_EC_REQUEST_PREAMBLE \
66 offsetof(struct cros_ish_out_msg, ec_request)
67
68#define cl_data_to_dev(client_data) ishtp_device((client_data)->cl_device)
69
70/*
71 * The Read-Write Semaphore is used to prevent message TX or RX while
72 * the ishtp client is being initialized or undergoing reset.
73 *
74 * The readers are the kernel function calls responsible for IA->ISH
75 * and ISH->AP messaging.
76 *
77 * The writers are .reset() and .probe() function.
78 */
79DECLARE_RWSEM(init_lock);
80
81/**
82 * struct response_info - Encapsulate firmware response related
83 * information for passing between function ish_send() and
84 * process_recv() callback.
85 *
86 * @data: Copy the data received from firmware here.
87 * @max_size: Max size allocated for the @data buffer. If the received
88 * data exceeds this value, we log an error.
89 * @size: Actual size of data received from firmware.
90 * @error: 0 for success, negative error code for a failure in process_recv().
91 * @received: Set to true on receiving a valid firmware response to host command
92 * @wait_queue: Wait queue for host to wait for firmware response.
93 */
94struct response_info {
95 void *data;
96 size_t max_size;
97 size_t size;
98 int error;
99 bool received;
100 wait_queue_head_t wait_queue;
101};
102
103/**
104 * struct ishtp_cl_data - Encapsulate per ISH TP Client.
105 *
106 * @cros_ish_cl: ISHTP firmware client instance.
107 * @cl_device: ISHTP client device instance.
108 * @response: Response info passing between ish_send() and process_recv().
109 * @work_ishtp_reset: Work queue reset handling.
110 * @work_ec_evt: Work queue for EC events.
111 * @ec_dev: CrOS EC MFD device.
112 *
113 * This structure is used to store per client data.
114 */
115struct ishtp_cl_data {
116 struct ishtp_cl *cros_ish_cl;
117 struct ishtp_cl_device *cl_device;
118
119 /*
120 * Used for passing firmware response information between
121 * ish_send() and process_recv() callback.
122 */
123 struct response_info response;
124
125 struct work_struct work_ishtp_reset;
126 struct work_struct work_ec_evt;
127 struct cros_ec_device *ec_dev;
128};
129
130/**
131 * ish_evt_handler - ISH to AP event handler
132 * @work: Work struct
133 */
134static void ish_evt_handler(struct work_struct *work)
135{
136 struct ishtp_cl_data *client_data =
137 container_of(work, struct ishtp_cl_data, work_ec_evt);
138 struct cros_ec_device *ec_dev = client_data->ec_dev;
139
140 if (cros_ec_get_next_event(ec_dev, NULL) > 0) {
141 blocking_notifier_call_chain(&ec_dev->event_notifier,
142 0, ec_dev);
143 }
144}
145
146/**
147 * ish_send() - Send message from host to firmware
148 *
149 * @client_data: Client data instance
150 * @out_msg: Message buffer to be sent to firmware
151 * @out_size: Size of out going message
152 * @in_msg: Message buffer where the incoming data is copied. This buffer
153 * is allocated by calling
154 * @in_size: Max size of incoming message
155 *
156 * Return: Number of bytes copied in the in_msg on success, negative
157 * error code on failure.
158 */
159static int ish_send(struct ishtp_cl_data *client_data,
160 u8 *out_msg, size_t out_size,
161 u8 *in_msg, size_t in_size)
162{
163 int rv;
164 struct header *out_hdr = (struct header *)out_msg;
165 struct ishtp_cl *cros_ish_cl = client_data->cros_ish_cl;
166
167 dev_dbg(cl_data_to_dev(client_data),
168 "%s: channel=%02u status=%02u\n",
169 __func__, out_hdr->channel, out_hdr->status);
170
171 /* Setup for incoming response */
172 client_data->response.data = in_msg;
173 client_data->response.max_size = in_size;
174 client_data->response.error = 0;
175 client_data->response.received = false;
176
177 rv = ishtp_cl_send(cros_ish_cl, out_msg, out_size);
178 if (rv) {
179 dev_err(cl_data_to_dev(client_data),
180 "ishtp_cl_send error %d\n", rv);
181 return rv;
182 }
183
184 wait_event_interruptible_timeout(client_data->response.wait_queue,
185 client_data->response.received,
186 ISHTP_SEND_TIMEOUT);
187 if (!client_data->response.received) {
188 dev_err(cl_data_to_dev(client_data),
189 "Timed out for response to host message\n");
190 return -ETIMEDOUT;
191 }
192
193 if (client_data->response.error < 0)
194 return client_data->response.error;
195
196 return client_data->response.size;
197}
198
199/**
200 * process_recv() - Received and parse incoming packet
201 * @cros_ish_cl: Client instance to get stats
202 * @rb_in_proc: Host interface message buffer
203 *
204 * Parse the incoming packet. If it is a response packet then it will
205 * update per instance flags and wake up the caller waiting to for the
206 * response. If it is an event packet then it will schedule event work.
207 */
208static void process_recv(struct ishtp_cl *cros_ish_cl,
209 struct ishtp_cl_rb *rb_in_proc)
210{
211 size_t data_len = rb_in_proc->buf_idx;
212 struct ishtp_cl_data *client_data =
213 ishtp_get_client_data(cros_ish_cl);
214 struct device *dev = cl_data_to_dev(client_data);
215 struct cros_ish_in_msg *in_msg =
216 (struct cros_ish_in_msg *)rb_in_proc->buffer.data;
217
218 /* Proceed only if reset or init is not in progress */
219 if (!down_read_trylock(&init_lock)) {
220 /* Free the buffer */
221 ishtp_cl_io_rb_recycle(rb_in_proc);
222 dev_warn(dev,
223 "Host is not ready to receive incoming messages\n");
224 return;
225 }
226
227 /*
228 * All firmware messages contain a header. Check the buffer size
229 * before accessing elements inside.
230 */
231 if (!rb_in_proc->buffer.data) {
232 dev_warn(dev, "rb_in_proc->buffer.data returned null");
233 client_data->response.error = -EBADMSG;
234 goto end_error;
235 }
236
237 if (data_len < sizeof(struct header)) {
238 dev_err(dev, "data size %zu is less than header %zu\n",
239 data_len, sizeof(struct header));
240 client_data->response.error = -EMSGSIZE;
241 goto end_error;
242 }
243
244 dev_dbg(dev, "channel=%02u status=%02u\n",
245 in_msg->hdr.channel, in_msg->hdr.status);
246
247 switch (in_msg->hdr.channel) {
248 case CROS_EC_COMMAND:
249 /* Sanity check */
250 if (!client_data->response.data) {
251 dev_err(dev,
252 "Receiving buffer is null. Should be allocated by calling function\n");
253 client_data->response.error = -EINVAL;
254 goto error_wake_up;
255 }
256
257 if (client_data->response.received) {
258 dev_err(dev,
259 "Previous firmware message not yet processed\n");
260 client_data->response.error = -EINVAL;
261 goto error_wake_up;
262 }
263
264 if (data_len > client_data->response.max_size) {
265 dev_err(dev,
266 "Received buffer size %zu is larger than allocated buffer %zu\n",
267 data_len, client_data->response.max_size);
268 client_data->response.error = -EMSGSIZE;
269 goto error_wake_up;
270 }
271
272 if (in_msg->hdr.status) {
273 dev_err(dev, "firmware returned status %d\n",
274 in_msg->hdr.status);
275 client_data->response.error = -EIO;
276 goto error_wake_up;
277 }
278
279 /* Update the actual received buffer size */
280 client_data->response.size = data_len;
281
282 /*
283 * Copy the buffer received in firmware response for the
284 * calling thread.
285 */
286 memcpy(client_data->response.data,
287 rb_in_proc->buffer.data, data_len);
288
289 /* Set flag before waking up the caller */
290 client_data->response.received = true;
291error_wake_up:
292 /* Wake the calling thread */
293 wake_up_interruptible(&client_data->response.wait_queue);
294
295 break;
296
297 case CROS_MKBP_EVENT:
298 /* The event system doesn't send any data in buffer */
299 schedule_work(&client_data->work_ec_evt);
300
301 break;
302
303 default:
304 dev_err(dev, "Invalid channel=%02d\n", in_msg->hdr.channel);
305 }
306
307end_error:
308 /* Free the buffer */
309 ishtp_cl_io_rb_recycle(rb_in_proc);
310
311 up_read(&init_lock);
312}
313
314/**
315 * ish_event_cb() - bus driver callback for incoming message
316 * @cl_device: ISHTP client device for which this message is targeted.
317 *
318 * Remove the packet from the list and process the message by calling
319 * process_recv.
320 */
321static void ish_event_cb(struct ishtp_cl_device *cl_device)
322{
323 struct ishtp_cl_rb *rb_in_proc;
324 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
325
326 while ((rb_in_proc = ishtp_cl_rx_get_rb(cros_ish_cl)) != NULL) {
327 /* Decide what to do with received data */
328 process_recv(cros_ish_cl, rb_in_proc);
329 }
330}
331
332/**
333 * cros_ish_init() - Init function for ISHTP client
334 * @cros_ish_cl: ISHTP client instance
335 *
336 * This function complete the initializtion of the client.
337 *
338 * Return: 0 for success, negative error code for failure.
339 */
340static int cros_ish_init(struct ishtp_cl *cros_ish_cl)
341{
342 int rv;
343 struct ishtp_device *dev;
344 struct ishtp_fw_client *fw_client;
345 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
346
347 rv = ishtp_cl_link(cros_ish_cl);
348 if (rv) {
349 dev_err(cl_data_to_dev(client_data),
350 "ishtp_cl_link failed\n");
351 return rv;
352 }
353
354 dev = ishtp_get_ishtp_device(cros_ish_cl);
355
356 /* Connect to firmware client */
357 ishtp_set_tx_ring_size(cros_ish_cl, CROS_ISH_CL_TX_RING_SIZE);
358 ishtp_set_rx_ring_size(cros_ish_cl, CROS_ISH_CL_RX_RING_SIZE);
359
360 fw_client = ishtp_fw_cl_get_client(dev, &cros_ish_guid);
361 if (!fw_client) {
362 dev_err(cl_data_to_dev(client_data),
363 "ish client uuid not found\n");
364 rv = -ENOENT;
365 goto err_cl_unlink;
366 }
367
368 ishtp_cl_set_fw_client_id(cros_ish_cl,
369 ishtp_get_fw_client_id(fw_client));
370 ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_CONNECTING);
371
372 rv = ishtp_cl_connect(cros_ish_cl);
373 if (rv) {
374 dev_err(cl_data_to_dev(client_data),
375 "client connect fail\n");
376 goto err_cl_unlink;
377 }
378
379 ishtp_register_event_cb(client_data->cl_device, ish_event_cb);
380 return 0;
381
382err_cl_unlink:
383 ishtp_cl_unlink(cros_ish_cl);
384 return rv;
385}
386
387/**
388 * cros_ish_deinit() - Deinit function for ISHTP client
389 * @cros_ish_cl: ISHTP client instance
390 *
391 * Unlink and free cros_ec client
392 */
393static void cros_ish_deinit(struct ishtp_cl *cros_ish_cl)
394{
395 ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_DISCONNECTING);
396 ishtp_cl_disconnect(cros_ish_cl);
397 ishtp_cl_unlink(cros_ish_cl);
398 ishtp_cl_flush_queues(cros_ish_cl);
399
400 /* Disband and free all Tx and Rx client-level rings */
401 ishtp_cl_free(cros_ish_cl);
402}
403
404/**
405 * prepare_cros_ec_rx() - Check & prepare receive buffer
406 * @ec_dev: CrOS EC MFD device.
407 * @in_msg: Incoming message buffer
408 * @msg: cros_ec command used to send & receive data
409 *
410 * Return: 0 for success, negative error code for failure.
411 *
412 * Check the received buffer. Convert to cros_ec_command format.
413 */
414static int prepare_cros_ec_rx(struct cros_ec_device *ec_dev,
415 const struct cros_ish_in_msg *in_msg,
416 struct cros_ec_command *msg)
417{
418 u8 sum = 0;
419 int i, rv, offset;
420
421 /* Check response error code */
422 msg->result = in_msg->ec_response.result;
423 rv = cros_ec_check_result(ec_dev, msg);
424 if (rv < 0)
425 return rv;
426
427 if (in_msg->ec_response.data_len > msg->insize) {
428 dev_err(ec_dev->dev, "Packet too long (%d bytes, expected %d)",
429 in_msg->ec_response.data_len, msg->insize);
430 return -ENOSPC;
431 }
432
433 /* Copy response packet payload and compute checksum */
434 for (i = 0; i < sizeof(struct ec_host_response); i++)
435 sum += ((u8 *)in_msg)[IN_MSG_EC_RESPONSE_PREAMBLE + i];
436
437 offset = sizeof(struct cros_ish_in_msg);
438 for (i = 0; i < in_msg->ec_response.data_len; i++)
439 sum += msg->data[i] = ((u8 *)in_msg)[offset + i];
440
441 if (sum) {
442 dev_dbg(ec_dev->dev, "Bad received packet checksum %d\n", sum);
443 return -EBADMSG;
444 }
445
446 return 0;
447}
448
449static int cros_ec_pkt_xfer_ish(struct cros_ec_device *ec_dev,
450 struct cros_ec_command *msg)
451{
452 int rv;
453 struct ishtp_cl *cros_ish_cl = ec_dev->priv;
454 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
455 struct device *dev = cl_data_to_dev(client_data);
456 struct cros_ish_in_msg *in_msg = (struct cros_ish_in_msg *)ec_dev->din;
457 struct cros_ish_out_msg *out_msg =
458 (struct cros_ish_out_msg *)ec_dev->dout;
459 size_t in_size = sizeof(struct cros_ish_in_msg) + msg->insize;
460 size_t out_size = sizeof(struct cros_ish_out_msg) + msg->outsize;
461
462 /* Sanity checks */
463 if (in_size > ec_dev->din_size) {
464 dev_err(dev,
465 "Incoming payload size %zu is too large for ec_dev->din_size %d\n",
466 in_size, ec_dev->din_size);
467 return -EMSGSIZE;
468 }
469
470 if (out_size > ec_dev->dout_size) {
471 dev_err(dev,
472 "Outgoing payload size %zu is too large for ec_dev->dout_size %d\n",
473 out_size, ec_dev->dout_size);
474 return -EMSGSIZE;
475 }
476
477 /* Proceed only if reset-init is not in progress */
478 if (!down_read_trylock(&init_lock)) {
479 dev_warn(dev,
480 "Host is not ready to send messages to ISH. Try again\n");
481 return -EAGAIN;
482 }
483
484 /* Prepare the package to be sent over ISH TP */
485 out_msg->hdr.channel = CROS_EC_COMMAND;
486 out_msg->hdr.status = 0;
487
488 ec_dev->dout += OUT_MSG_EC_REQUEST_PREAMBLE;
489 cros_ec_prepare_tx(ec_dev, msg);
490 ec_dev->dout -= OUT_MSG_EC_REQUEST_PREAMBLE;
491
492 dev_dbg(dev,
493 "out_msg: struct_ver=0x%x checksum=0x%x command=0x%x command_ver=0x%x data_len=0x%x\n",
494 out_msg->ec_request.struct_version,
495 out_msg->ec_request.checksum,
496 out_msg->ec_request.command,
497 out_msg->ec_request.command_version,
498 out_msg->ec_request.data_len);
499
500 /* Send command to ISH EC firmware and read response */
501 rv = ish_send(client_data,
502 (u8 *)out_msg, out_size,
503 (u8 *)in_msg, in_size);
504 if (rv < 0)
505 goto end_error;
506
507 rv = prepare_cros_ec_rx(ec_dev, in_msg, msg);
508 if (rv)
509 goto end_error;
510
511 rv = in_msg->ec_response.data_len;
512
513 dev_dbg(dev,
514 "in_msg: struct_ver=0x%x checksum=0x%x result=0x%x data_len=0x%x\n",
515 in_msg->ec_response.struct_version,
516 in_msg->ec_response.checksum,
517 in_msg->ec_response.result,
518 in_msg->ec_response.data_len);
519
520end_error:
521 if (msg->command == EC_CMD_REBOOT_EC)
522 msleep(EC_REBOOT_DELAY_MS);
523
524 up_read(&init_lock);
525
526 return rv;
527}
528
529static int cros_ec_dev_init(struct ishtp_cl_data *client_data)
530{
531 struct cros_ec_device *ec_dev;
532 struct device *dev = cl_data_to_dev(client_data);
533
534 ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
535 if (!ec_dev)
536 return -ENOMEM;
537
538 client_data->ec_dev = ec_dev;
539 dev->driver_data = ec_dev;
540
541 ec_dev->dev = dev;
542 ec_dev->priv = client_data->cros_ish_cl;
543 ec_dev->cmd_xfer = NULL;
544 ec_dev->pkt_xfer = cros_ec_pkt_xfer_ish;
545 ec_dev->phys_name = dev_name(dev);
546 ec_dev->din_size = sizeof(struct cros_ish_in_msg) +
547 sizeof(struct ec_response_get_protocol_info);
548 ec_dev->dout_size = sizeof(struct cros_ish_out_msg);
549
550 return cros_ec_register(ec_dev);
551}
552
553static void reset_handler(struct work_struct *work)
554{
555 int rv;
556 struct device *dev;
557 struct ishtp_cl *cros_ish_cl;
558 struct ishtp_cl_device *cl_device;
559 struct ishtp_cl_data *client_data =
560 container_of(work, struct ishtp_cl_data, work_ishtp_reset);
561
562 /* Lock for reset to complete */
563 down_write(&init_lock);
564
565 cros_ish_cl = client_data->cros_ish_cl;
566 cl_device = client_data->cl_device;
567
568 /* Unlink, flush queues & start again */
569 ishtp_cl_unlink(cros_ish_cl);
570 ishtp_cl_flush_queues(cros_ish_cl);
571 ishtp_cl_free(cros_ish_cl);
572
573 cros_ish_cl = ishtp_cl_allocate(cl_device);
574 if (!cros_ish_cl) {
575 up_write(&init_lock);
576 return;
577 }
578
579 ishtp_set_drvdata(cl_device, cros_ish_cl);
580 ishtp_set_client_data(cros_ish_cl, client_data);
581 client_data->cros_ish_cl = cros_ish_cl;
582
583 rv = cros_ish_init(cros_ish_cl);
584 if (rv) {
585 ishtp_cl_free(cros_ish_cl);
586 dev_err(cl_data_to_dev(client_data), "Reset Failed\n");
587 up_write(&init_lock);
588 return;
589 }
590
591 /* Refresh ec_dev device pointers */
592 client_data->ec_dev->priv = client_data->cros_ish_cl;
593 dev = cl_data_to_dev(client_data);
594 dev->driver_data = client_data->ec_dev;
595
596 dev_info(cl_data_to_dev(client_data), "Chrome EC ISH reset done\n");
597
598 up_write(&init_lock);
599}
600
601/**
602 * cros_ec_ishtp_probe() - ISHTP client driver probe callback
603 * @cl_device: ISHTP client device instance
604 *
605 * Return: 0 for success, negative error code for failure.
606 */
607static int cros_ec_ishtp_probe(struct ishtp_cl_device *cl_device)
608{
609 int rv;
610 struct ishtp_cl *cros_ish_cl;
611 struct ishtp_cl_data *client_data =
612 devm_kzalloc(ishtp_device(cl_device),
613 sizeof(*client_data), GFP_KERNEL);
614 if (!client_data)
615 return -ENOMEM;
616
617 /* Lock for initialization to complete */
618 down_write(&init_lock);
619
620 cros_ish_cl = ishtp_cl_allocate(cl_device);
621 if (!cros_ish_cl) {
622 rv = -ENOMEM;
623 goto end_ishtp_cl_alloc_error;
624 }
625
626 ishtp_set_drvdata(cl_device, cros_ish_cl);
627 ishtp_set_client_data(cros_ish_cl, client_data);
628 client_data->cros_ish_cl = cros_ish_cl;
629 client_data->cl_device = cl_device;
630
631 init_waitqueue_head(&client_data->response.wait_queue);
632
633 INIT_WORK(&client_data->work_ishtp_reset,
634 reset_handler);
635 INIT_WORK(&client_data->work_ec_evt,
636 ish_evt_handler);
637
638 rv = cros_ish_init(cros_ish_cl);
639 if (rv)
640 goto end_ishtp_cl_init_error;
641
642 ishtp_get_device(cl_device);
643
644 up_write(&init_lock);
645
646 /* Register croc_ec_dev mfd */
647 rv = cros_ec_dev_init(client_data);
648 if (rv)
649 goto end_cros_ec_dev_init_error;
650
651 return 0;
652
653end_cros_ec_dev_init_error:
654 ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_DISCONNECTING);
655 ishtp_cl_disconnect(cros_ish_cl);
656 ishtp_cl_unlink(cros_ish_cl);
657 ishtp_cl_flush_queues(cros_ish_cl);
658 ishtp_put_device(cl_device);
659end_ishtp_cl_init_error:
660 ishtp_cl_free(cros_ish_cl);
661end_ishtp_cl_alloc_error:
662 up_write(&init_lock);
663 return rv;
664}
665
666/**
667 * cros_ec_ishtp_remove() - ISHTP client driver remove callback
668 * @cl_device: ISHTP client device instance
669 *
670 * Return: 0
671 */
672static int cros_ec_ishtp_remove(struct ishtp_cl_device *cl_device)
673{
674 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
675 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
676
677 cancel_work_sync(&client_data->work_ishtp_reset);
678 cancel_work_sync(&client_data->work_ec_evt);
679 cros_ish_deinit(cros_ish_cl);
680 ishtp_put_device(cl_device);
681
682 return 0;
683}
684
685/**
686 * cros_ec_ishtp_reset() - ISHTP client driver reset callback
687 * @cl_device: ISHTP client device instance
688 *
689 * Return: 0
690 */
691static int cros_ec_ishtp_reset(struct ishtp_cl_device *cl_device)
692{
693 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
694 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
695
696 schedule_work(&client_data->work_ishtp_reset);
697
698 return 0;
699}
700
701/**
702 * cros_ec_ishtp_suspend() - ISHTP client driver suspend callback
703 * @device: device instance
704 *
705 * Return: 0 for success, negative error code for failure.
706 */
707static int __maybe_unused cros_ec_ishtp_suspend(struct device *device)
708{
709 struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(device);
710 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
711 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
712
713 return cros_ec_suspend(client_data->ec_dev);
714}
715
716/**
717 * cros_ec_ishtp_resume() - ISHTP client driver resume callback
718 * @device: device instance
719 *
720 * Return: 0 for success, negative error code for failure.
721 */
722static int __maybe_unused cros_ec_ishtp_resume(struct device *device)
723{
724 struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(device);
725 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
726 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
727
728 return cros_ec_resume(client_data->ec_dev);
729}
730
731static SIMPLE_DEV_PM_OPS(cros_ec_ishtp_pm_ops, cros_ec_ishtp_suspend,
732 cros_ec_ishtp_resume);
733
734static struct ishtp_cl_driver cros_ec_ishtp_driver = {
735 .name = "cros_ec_ishtp",
736 .guid = &cros_ish_guid,
737 .probe = cros_ec_ishtp_probe,
738 .remove = cros_ec_ishtp_remove,
739 .reset = cros_ec_ishtp_reset,
740 .driver = {
741 .pm = &cros_ec_ishtp_pm_ops,
742 },
743};
744
745static int __init cros_ec_ishtp_mod_init(void)
746{
747 return ishtp_cl_driver_register(&cros_ec_ishtp_driver, THIS_MODULE);
748}
749
750static void __exit cros_ec_ishtp_mod_exit(void)
751{
752 ishtp_cl_driver_unregister(&cros_ec_ishtp_driver);
753}
754
755module_init(cros_ec_ishtp_mod_init);
756module_exit(cros_ec_ishtp_mod_exit);
757
758MODULE_DESCRIPTION("ChromeOS EC ISHTP Client Driver");
759MODULE_AUTHOR("Rushikesh S Kadam <rushikesh.s.kadam@intel.com>");
760
761MODULE_LICENSE("GPL v2");
762MODULE_ALIAS("ishtp:*");