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