xref: /linux/drivers/platform/chrome/cros_ec_ishtp.c (revision a44e4f3ab16bc808590763a543a93b6fbf3abcc4)
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 */
30 enum 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 */
42 static const guid_t cros_ish_guid =
43 	GUID_INIT(0x7b7154d0, 0x56f4, 0x4bdc,
44 		  0xb0, 0xd8, 0x9e, 0x7c, 0xda,	0xe0, 0xd6, 0xa0);
45 
46 struct header {
47 	u8 channel;
48 	u8 status;
49 	u8 reserved[2];
50 } __packed;
51 
52 struct cros_ish_out_msg {
53 	struct header hdr;
54 	struct ec_host_request ec_request;
55 } __packed;
56 
57 struct 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  */
79 DECLARE_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  */
94 struct 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  */
115 struct 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  */
134 static 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  */
159 static 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  */
208 static 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;
291 error_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 
307 end_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  */
321 static 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  */
340 static 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 
382 err_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  */
393 static 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  */
414 static 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 
449 static 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 
520 end_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 
529 static 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 
553 static 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  */
607 static 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 
653 end_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);
659 end_ishtp_cl_init_error:
660 	ishtp_cl_free(cros_ish_cl);
661 end_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  */
672 static 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  */
691 static 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  */
707 static 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  */
722 static 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 
731 static SIMPLE_DEV_PM_OPS(cros_ec_ishtp_pm_ops, cros_ec_ishtp_suspend,
732 			 cros_ec_ishtp_resume);
733 
734 static 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 
745 static int __init cros_ec_ishtp_mod_init(void)
746 {
747 	return ishtp_cl_driver_register(&cros_ec_ishtp_driver, THIS_MODULE);
748 }
749 
750 static void __exit cros_ec_ishtp_mod_exit(void)
751 {
752 	ishtp_cl_driver_unregister(&cros_ec_ishtp_driver);
753 }
754 
755 module_init(cros_ec_ishtp_mod_init);
756 module_exit(cros_ec_ishtp_mod_exit);
757 
758 MODULE_DESCRIPTION("ChromeOS EC ISHTP Client Driver");
759 MODULE_AUTHOR("Rushikesh S Kadam <rushikesh.s.kadam@intel.com>");
760 
761 MODULE_LICENSE("GPL v2");
762 MODULE_ALIAS("ishtp:*");
763