xref: /linux/drivers/platform/chrome/cros_ec_ishtp.c (revision 06d07429858317ded2db7986113a9e0129cd599b)
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 struct ishtp_device_id cros_ec_ishtp_id_table[] = {
45 	{ .guid = GUID_INIT(0x7b7154d0, 0x56f4, 0x4bdc,
46 		  0xb0, 0xd8, 0x9e, 0x7c, 0xda,	0xe0, 0xd6, 0xa0), },
47 	{ }
48 };
49 MODULE_DEVICE_TABLE(ishtp, cros_ec_ishtp_id_table);
50 
51 struct header {
52 	u8 channel;
53 	u8 status;
54 	u8 token;
55 	u8 reserved;
56 } __packed;
57 
58 struct cros_ish_out_msg {
59 	struct header hdr;
60 	struct ec_host_request ec_request;
61 } __packed;
62 
63 struct cros_ish_in_msg {
64 	struct header hdr;
65 	struct ec_host_response ec_response;
66 } __packed;
67 
68 #define IN_MSG_EC_RESPONSE_PREAMBLE					\
69 	offsetof(struct cros_ish_in_msg, ec_response)
70 
71 #define OUT_MSG_EC_REQUEST_PREAMBLE					\
72 	offsetof(struct cros_ish_out_msg, ec_request)
73 
74 #define cl_data_to_dev(client_data) ishtp_device((client_data)->cl_device)
75 
76 /*
77  * The Read-Write Semaphore is used to prevent message TX or RX while
78  * the ishtp client is being initialized or undergoing reset.
79  *
80  * The readers are the kernel function calls responsible for IA->ISH
81  * and ISH->AP messaging.
82  *
83  * The writers are .reset() and .probe() function.
84  */
85 static DECLARE_RWSEM(init_lock);
86 
87 /**
88  * struct response_info - Encapsulate firmware response related
89  * information for passing between function ish_send() and
90  * process_recv() callback.
91  *
92  * @data: Copy the data received from firmware here.
93  * @max_size: Max size allocated for the @data buffer. If the received
94  * data exceeds this value, we log an error.
95  * @size: Actual size of data received from firmware.
96  * @error: 0 for success, negative error code for a failure in process_recv().
97  * @token: Expected token for response that we are waiting on.
98  * @received: Set to true on receiving a valid firmware	response to host command
99  * @wait_queue: Wait queue for host to wait for firmware response.
100  */
101 struct response_info {
102 	void *data;
103 	size_t max_size;
104 	size_t size;
105 	int error;
106 	u8 token;
107 	bool received;
108 	wait_queue_head_t wait_queue;
109 };
110 
111 /**
112  * struct ishtp_cl_data - Encapsulate per ISH TP Client.
113  *
114  * @cros_ish_cl: ISHTP firmware client instance.
115  * @cl_device: ISHTP client device instance.
116  * @response: Response info passing between ish_send() and process_recv().
117  * @work_ishtp_reset: Work queue reset handling.
118  * @work_ec_evt: Work queue for EC events.
119  * @ec_dev: CrOS EC MFD device.
120  *
121  * This structure is used to store per client data.
122  */
123 struct ishtp_cl_data {
124 	struct ishtp_cl *cros_ish_cl;
125 	struct ishtp_cl_device *cl_device;
126 
127 	/*
128 	 * Used for passing firmware response information between
129 	 * ish_send() and process_recv() callback.
130 	 */
131 	struct response_info response;
132 
133 	struct work_struct work_ishtp_reset;
134 	struct work_struct work_ec_evt;
135 	struct cros_ec_device *ec_dev;
136 };
137 
138 /**
139  * ish_evt_handler - ISH to AP event handler
140  * @work: Work struct
141  */
ish_evt_handler(struct work_struct * work)142 static void ish_evt_handler(struct work_struct *work)
143 {
144 	struct ishtp_cl_data *client_data =
145 		container_of(work, struct ishtp_cl_data, work_ec_evt);
146 
147 	cros_ec_irq_thread(0, client_data->ec_dev);
148 }
149 
150 /**
151  * ish_send() - Send message from host to firmware
152  *
153  * @client_data: Client data instance
154  * @out_msg: Message buffer to be sent to firmware
155  * @out_size: Size of out going message
156  * @in_msg: Message buffer where the incoming data is copied. This buffer
157  * is allocated by calling
158  * @in_size: Max size of incoming message
159  *
160  * Return: Number of bytes copied in the in_msg on success, negative
161  * error code on failure.
162  */
ish_send(struct ishtp_cl_data * client_data,u8 * out_msg,size_t out_size,u8 * in_msg,size_t in_size)163 static int ish_send(struct ishtp_cl_data *client_data,
164 		    u8 *out_msg, size_t out_size,
165 		    u8 *in_msg, size_t in_size)
166 {
167 	static u8 next_token;
168 	int rv;
169 	struct header *out_hdr = (struct header *)out_msg;
170 	struct ishtp_cl *cros_ish_cl = client_data->cros_ish_cl;
171 
172 	dev_dbg(cl_data_to_dev(client_data),
173 		"%s: channel=%02u status=%02u\n",
174 		__func__, out_hdr->channel, out_hdr->status);
175 
176 	/* Setup for incoming response */
177 	client_data->response.data = in_msg;
178 	client_data->response.max_size = in_size;
179 	client_data->response.error = 0;
180 	client_data->response.token = next_token++;
181 	client_data->response.received = false;
182 
183 	out_hdr->token = client_data->response.token;
184 
185 	rv = ishtp_cl_send(cros_ish_cl, out_msg, out_size);
186 	if (rv) {
187 		dev_err(cl_data_to_dev(client_data),
188 			"ishtp_cl_send error %d\n", rv);
189 		return rv;
190 	}
191 
192 	wait_event_interruptible_timeout(client_data->response.wait_queue,
193 					 client_data->response.received,
194 					 ISHTP_SEND_TIMEOUT);
195 	if (!client_data->response.received) {
196 		dev_err(cl_data_to_dev(client_data),
197 			"Timed out for response to host message\n");
198 		return -ETIMEDOUT;
199 	}
200 
201 	if (client_data->response.error < 0)
202 		return client_data->response.error;
203 
204 	return client_data->response.size;
205 }
206 
207 /**
208  * process_recv() - Received and parse incoming packet
209  * @cros_ish_cl: Client instance to get stats
210  * @rb_in_proc: Host interface message buffer
211  * @timestamp: Timestamp of when parent callback started
212  *
213  * Parse the incoming packet. If it is a response packet then it will
214  * update per instance flags and wake up the caller waiting to for the
215  * response. If it is an event packet then it will schedule event work.
216  */
process_recv(struct ishtp_cl * cros_ish_cl,struct ishtp_cl_rb * rb_in_proc,ktime_t timestamp)217 static void process_recv(struct ishtp_cl *cros_ish_cl,
218 			 struct ishtp_cl_rb *rb_in_proc, ktime_t timestamp)
219 {
220 	size_t data_len = rb_in_proc->buf_idx;
221 	struct ishtp_cl_data *client_data =
222 		ishtp_get_client_data(cros_ish_cl);
223 	struct device *dev = cl_data_to_dev(client_data);
224 	struct cros_ish_in_msg *in_msg =
225 		(struct cros_ish_in_msg *)rb_in_proc->buffer.data;
226 
227 	/* Proceed only if reset or init is not in progress */
228 	if (!down_read_trylock(&init_lock)) {
229 		/* Free the buffer */
230 		ishtp_cl_io_rb_recycle(rb_in_proc);
231 		dev_warn(dev,
232 			 "Host is not ready to receive incoming messages\n");
233 		return;
234 	}
235 
236 	/*
237 	 * All firmware messages contain a header. Check the buffer size
238 	 * before accessing elements inside.
239 	 */
240 	if (!rb_in_proc->buffer.data) {
241 		dev_warn(dev, "rb_in_proc->buffer.data returned null");
242 		client_data->response.error = -EBADMSG;
243 		goto end_error;
244 	}
245 
246 	if (data_len < sizeof(struct header)) {
247 		dev_err(dev, "data size %zu is less than header %zu\n",
248 			data_len, sizeof(struct header));
249 		client_data->response.error = -EMSGSIZE;
250 		goto end_error;
251 	}
252 
253 	dev_dbg(dev, "channel=%02u status=%02u\n",
254 		in_msg->hdr.channel, in_msg->hdr.status);
255 
256 	switch (in_msg->hdr.channel) {
257 	case CROS_EC_COMMAND:
258 		if (client_data->response.received) {
259 			dev_err(dev,
260 				"Previous firmware message not yet processed\n");
261 			goto end_error;
262 		}
263 
264 		if (client_data->response.token != in_msg->hdr.token) {
265 			dev_err_ratelimited(dev,
266 					    "Dropping old response token %d\n",
267 					    in_msg->hdr.token);
268 			goto end_error;
269 		}
270 
271 		/* Sanity check */
272 		if (!client_data->response.data) {
273 			dev_err(dev,
274 				"Receiving buffer is null. Should be allocated by calling function\n");
275 			client_data->response.error = -EINVAL;
276 			goto error_wake_up;
277 		}
278 
279 		if (data_len > client_data->response.max_size) {
280 			dev_err(dev,
281 				"Received buffer size %zu is larger than allocated buffer %zu\n",
282 				data_len, client_data->response.max_size);
283 			client_data->response.error = -EMSGSIZE;
284 			goto error_wake_up;
285 		}
286 
287 		if (in_msg->hdr.status) {
288 			dev_err(dev, "firmware returned status %d\n",
289 				in_msg->hdr.status);
290 			client_data->response.error = -EIO;
291 			goto error_wake_up;
292 		}
293 
294 		/* Update the actual received buffer size */
295 		client_data->response.size = data_len;
296 
297 		/*
298 		 * Copy the buffer received in firmware response for the
299 		 * calling thread.
300 		 */
301 		memcpy(client_data->response.data,
302 		       rb_in_proc->buffer.data, data_len);
303 
304 error_wake_up:
305 		/* Free the buffer since we copied data or didn't need it */
306 		ishtp_cl_io_rb_recycle(rb_in_proc);
307 		rb_in_proc = NULL;
308 
309 		/* Set flag before waking up the caller */
310 		client_data->response.received = true;
311 
312 		/* Wake the calling thread */
313 		wake_up_interruptible(&client_data->response.wait_queue);
314 
315 		break;
316 
317 	case CROS_MKBP_EVENT:
318 		/* Free the buffer. This is just an event without data */
319 		ishtp_cl_io_rb_recycle(rb_in_proc);
320 		rb_in_proc = NULL;
321 		/*
322 		 * Set timestamp from beginning of function since we actually
323 		 * got an incoming MKBP event
324 		 */
325 		client_data->ec_dev->last_event_time = timestamp;
326 		schedule_work(&client_data->work_ec_evt);
327 
328 		break;
329 
330 	default:
331 		dev_err(dev, "Invalid channel=%02d\n", in_msg->hdr.channel);
332 	}
333 
334 end_error:
335 	/* Free the buffer if we already haven't */
336 	if (rb_in_proc)
337 		ishtp_cl_io_rb_recycle(rb_in_proc);
338 
339 	up_read(&init_lock);
340 }
341 
342 /**
343  * ish_event_cb() - bus driver callback for incoming message
344  * @cl_device: ISHTP client device for which this message is targeted.
345  *
346  * Remove the packet from the list and process the message by calling
347  * process_recv.
348  */
ish_event_cb(struct ishtp_cl_device * cl_device)349 static void ish_event_cb(struct ishtp_cl_device *cl_device)
350 {
351 	struct ishtp_cl_rb *rb_in_proc;
352 	struct ishtp_cl	*cros_ish_cl = ishtp_get_drvdata(cl_device);
353 	ktime_t timestamp;
354 
355 	/*
356 	 * Take timestamp as close to hardware interrupt as possible for sensor
357 	 * timestamps.
358 	 */
359 	timestamp = cros_ec_get_time_ns();
360 
361 	while ((rb_in_proc = ishtp_cl_rx_get_rb(cros_ish_cl)) != NULL) {
362 		/* Decide what to do with received data */
363 		process_recv(cros_ish_cl, rb_in_proc, timestamp);
364 	}
365 }
366 
367 /**
368  * cros_ish_init() - Init function for ISHTP client
369  * @cros_ish_cl: ISHTP client instance
370  * @reset: true if called from reset handler
371  *
372  * This function complete the initializtion of the client.
373  *
374  * Return: 0 for success, negative error code for failure.
375  */
cros_ish_init(struct ishtp_cl * cros_ish_cl,bool reset)376 static int cros_ish_init(struct ishtp_cl *cros_ish_cl, bool reset)
377 {
378 	int rv;
379 	struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
380 
381 	rv = ishtp_cl_establish_connection(cros_ish_cl,
382 					   &cros_ec_ishtp_id_table[0].guid,
383 					   CROS_ISH_CL_TX_RING_SIZE,
384 					   CROS_ISH_CL_RX_RING_SIZE,
385 					   reset);
386 	if (rv) {
387 		dev_err(cl_data_to_dev(client_data),
388 			"client connect fail\n");
389 		goto err_cl_disconnect;
390 	}
391 
392 	ishtp_register_event_cb(client_data->cl_device, ish_event_cb);
393 	return 0;
394 
395 err_cl_disconnect:
396 	ishtp_cl_destroy_connection(cros_ish_cl, reset);
397 	return rv;
398 }
399 
400 /**
401  * cros_ish_deinit() - Deinit function for ISHTP client
402  * @cros_ish_cl: ISHTP client instance
403  *
404  * Unlink and free cros_ec client
405  */
cros_ish_deinit(struct ishtp_cl * cros_ish_cl)406 static void cros_ish_deinit(struct ishtp_cl *cros_ish_cl)
407 {
408 	ishtp_cl_destroy_connection(cros_ish_cl, false);
409 
410 	/* Disband and free all Tx and Rx client-level rings */
411 	ishtp_cl_free(cros_ish_cl);
412 }
413 
414 /**
415  * prepare_cros_ec_rx() - Check & prepare receive buffer
416  * @ec_dev: CrOS EC MFD device.
417  * @in_msg: Incoming message buffer
418  * @msg: cros_ec command used to send & receive data
419  *
420  * Return: 0 for success, negative error code for failure.
421  *
422  * Check the received buffer. Convert to cros_ec_command format.
423  */
prepare_cros_ec_rx(struct cros_ec_device * ec_dev,const struct cros_ish_in_msg * in_msg,struct cros_ec_command * msg)424 static int prepare_cros_ec_rx(struct cros_ec_device *ec_dev,
425 			      const struct cros_ish_in_msg *in_msg,
426 			      struct cros_ec_command *msg)
427 {
428 	u8 sum = 0;
429 	int i, rv, offset;
430 
431 	/* Check response error code */
432 	msg->result = in_msg->ec_response.result;
433 	rv = cros_ec_check_result(ec_dev, msg);
434 	if (rv < 0)
435 		return rv;
436 
437 	if (in_msg->ec_response.data_len > msg->insize) {
438 		dev_err(ec_dev->dev, "Packet too long (%d bytes, expected %d)",
439 			in_msg->ec_response.data_len, msg->insize);
440 		return -ENOSPC;
441 	}
442 
443 	/* Copy response packet payload and compute checksum */
444 	for (i = 0; i < sizeof(struct ec_host_response); i++)
445 		sum += ((u8 *)in_msg)[IN_MSG_EC_RESPONSE_PREAMBLE + i];
446 
447 	offset = sizeof(struct cros_ish_in_msg);
448 	for (i = 0; i < in_msg->ec_response.data_len; i++)
449 		sum += msg->data[i] = ((u8 *)in_msg)[offset + i];
450 
451 	if (sum) {
452 		dev_dbg(ec_dev->dev, "Bad received packet checksum %d\n", sum);
453 		return -EBADMSG;
454 	}
455 
456 	return 0;
457 }
458 
cros_ec_pkt_xfer_ish(struct cros_ec_device * ec_dev,struct cros_ec_command * msg)459 static int cros_ec_pkt_xfer_ish(struct cros_ec_device *ec_dev,
460 				struct cros_ec_command *msg)
461 {
462 	int rv;
463 	struct ishtp_cl *cros_ish_cl = ec_dev->priv;
464 	struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
465 	struct device *dev = cl_data_to_dev(client_data);
466 	struct cros_ish_in_msg *in_msg = (struct cros_ish_in_msg *)ec_dev->din;
467 	struct cros_ish_out_msg *out_msg =
468 		(struct cros_ish_out_msg *)ec_dev->dout;
469 	size_t in_size = sizeof(struct cros_ish_in_msg) + msg->insize;
470 	size_t out_size = sizeof(struct cros_ish_out_msg) + msg->outsize;
471 
472 	/* Sanity checks */
473 	if (in_size > ec_dev->din_size) {
474 		dev_err(dev,
475 			"Incoming payload size %zu is too large for ec_dev->din_size %d\n",
476 			in_size, ec_dev->din_size);
477 		return -EMSGSIZE;
478 	}
479 
480 	if (out_size > ec_dev->dout_size) {
481 		dev_err(dev,
482 			"Outgoing payload size %zu is too large for ec_dev->dout_size %d\n",
483 			out_size, ec_dev->dout_size);
484 		return -EMSGSIZE;
485 	}
486 
487 	/* Proceed only if reset-init is not in progress */
488 	if (!down_read_trylock(&init_lock)) {
489 		dev_warn(dev,
490 			 "Host is not ready to send messages to ISH. Try again\n");
491 		return -EAGAIN;
492 	}
493 
494 	/* Prepare the package to be sent over ISH TP */
495 	out_msg->hdr.channel = CROS_EC_COMMAND;
496 	out_msg->hdr.status = 0;
497 
498 	ec_dev->dout += OUT_MSG_EC_REQUEST_PREAMBLE;
499 	rv = cros_ec_prepare_tx(ec_dev, msg);
500 	if (rv < 0)
501 		goto end_error;
502 	ec_dev->dout -= OUT_MSG_EC_REQUEST_PREAMBLE;
503 
504 	dev_dbg(dev,
505 		"out_msg: struct_ver=0x%x checksum=0x%x command=0x%x command_ver=0x%x data_len=0x%x\n",
506 		out_msg->ec_request.struct_version,
507 		out_msg->ec_request.checksum,
508 		out_msg->ec_request.command,
509 		out_msg->ec_request.command_version,
510 		out_msg->ec_request.data_len);
511 
512 	/* Send command to ISH EC firmware and read response */
513 	rv = ish_send(client_data,
514 		      (u8 *)out_msg, out_size,
515 		      (u8 *)in_msg, in_size);
516 	if (rv < 0)
517 		goto end_error;
518 
519 	rv = prepare_cros_ec_rx(ec_dev, in_msg, msg);
520 	if (rv)
521 		goto end_error;
522 
523 	rv = in_msg->ec_response.data_len;
524 
525 	dev_dbg(dev,
526 		"in_msg: struct_ver=0x%x checksum=0x%x result=0x%x data_len=0x%x\n",
527 		in_msg->ec_response.struct_version,
528 		in_msg->ec_response.checksum,
529 		in_msg->ec_response.result,
530 		in_msg->ec_response.data_len);
531 
532 end_error:
533 	if (msg->command == EC_CMD_REBOOT_EC)
534 		msleep(EC_REBOOT_DELAY_MS);
535 
536 	up_read(&init_lock);
537 
538 	return rv;
539 }
540 
cros_ec_dev_init(struct ishtp_cl_data * client_data)541 static int cros_ec_dev_init(struct ishtp_cl_data *client_data)
542 {
543 	struct cros_ec_device *ec_dev;
544 	struct device *dev = cl_data_to_dev(client_data);
545 
546 	ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
547 	if (!ec_dev)
548 		return -ENOMEM;
549 
550 	client_data->ec_dev = ec_dev;
551 	dev->driver_data = ec_dev;
552 
553 	ec_dev->dev = dev;
554 	ec_dev->priv = client_data->cros_ish_cl;
555 	ec_dev->cmd_xfer = NULL;
556 	ec_dev->pkt_xfer = cros_ec_pkt_xfer_ish;
557 	ec_dev->phys_name = dev_name(dev);
558 	ec_dev->din_size = sizeof(struct cros_ish_in_msg) +
559 			   sizeof(struct ec_response_get_protocol_info);
560 	ec_dev->dout_size = sizeof(struct cros_ish_out_msg);
561 
562 	return cros_ec_register(ec_dev);
563 }
564 
reset_handler(struct work_struct * work)565 static void reset_handler(struct work_struct *work)
566 {
567 	int rv;
568 	struct device *dev;
569 	struct ishtp_cl *cros_ish_cl;
570 	struct ishtp_cl_data *client_data =
571 		container_of(work, struct ishtp_cl_data, work_ishtp_reset);
572 
573 	/* Lock for reset to complete */
574 	down_write(&init_lock);
575 
576 	cros_ish_cl = client_data->cros_ish_cl;
577 
578 	ishtp_cl_destroy_connection(cros_ish_cl, true);
579 
580 	rv = cros_ish_init(cros_ish_cl, true);
581 	if (rv) {
582 		dev_err(cl_data_to_dev(client_data), "Reset Failed\n");
583 		up_write(&init_lock);
584 		return;
585 	}
586 
587 	/* Refresh ec_dev device pointers */
588 	client_data->ec_dev->priv = client_data->cros_ish_cl;
589 	dev = cl_data_to_dev(client_data);
590 	dev->driver_data = client_data->ec_dev;
591 
592 	dev_info(cl_data_to_dev(client_data), "Chrome EC ISH reset done\n");
593 
594 	up_write(&init_lock);
595 }
596 
597 /**
598  * cros_ec_ishtp_probe() - ISHTP client driver probe callback
599  * @cl_device: ISHTP client device instance
600  *
601  * Return: 0 for success, negative error code for failure.
602  */
cros_ec_ishtp_probe(struct ishtp_cl_device * cl_device)603 static int cros_ec_ishtp_probe(struct ishtp_cl_device *cl_device)
604 {
605 	int rv;
606 	struct ishtp_cl *cros_ish_cl;
607 	struct ishtp_cl_data *client_data =
608 		devm_kzalloc(ishtp_device(cl_device),
609 			     sizeof(*client_data), GFP_KERNEL);
610 	if (!client_data)
611 		return -ENOMEM;
612 
613 	/* Lock for initialization to complete */
614 	down_write(&init_lock);
615 
616 	cros_ish_cl = ishtp_cl_allocate(cl_device);
617 	if (!cros_ish_cl) {
618 		rv = -ENOMEM;
619 		goto end_ishtp_cl_alloc_error;
620 	}
621 
622 	ishtp_set_drvdata(cl_device, cros_ish_cl);
623 	ishtp_set_client_data(cros_ish_cl, client_data);
624 	client_data->cros_ish_cl = cros_ish_cl;
625 	client_data->cl_device = cl_device;
626 
627 	init_waitqueue_head(&client_data->response.wait_queue);
628 
629 	INIT_WORK(&client_data->work_ishtp_reset,
630 		  reset_handler);
631 	INIT_WORK(&client_data->work_ec_evt,
632 		  ish_evt_handler);
633 
634 	rv = cros_ish_init(cros_ish_cl, false);
635 	if (rv)
636 		goto end_ishtp_cl_init_error;
637 
638 	ishtp_get_device(cl_device);
639 
640 	up_write(&init_lock);
641 
642 	/* Register croc_ec_dev mfd */
643 	rv = cros_ec_dev_init(client_data);
644 	if (rv) {
645 		down_write(&init_lock);
646 		goto end_cros_ec_dev_init_error;
647 	}
648 
649 	return 0;
650 
651 end_cros_ec_dev_init_error:
652 	ishtp_cl_destroy_connection(cros_ish_cl, false);
653 	ishtp_put_device(cl_device);
654 end_ishtp_cl_init_error:
655 	ishtp_cl_free(cros_ish_cl);
656 end_ishtp_cl_alloc_error:
657 	up_write(&init_lock);
658 	return rv;
659 }
660 
661 /**
662  * cros_ec_ishtp_remove() - ISHTP client driver remove callback
663  * @cl_device: ISHTP client device instance
664  *
665  * Return: 0
666  */
cros_ec_ishtp_remove(struct ishtp_cl_device * cl_device)667 static void cros_ec_ishtp_remove(struct ishtp_cl_device *cl_device)
668 {
669 	struct ishtp_cl	*cros_ish_cl = ishtp_get_drvdata(cl_device);
670 	struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
671 
672 	cancel_work_sync(&client_data->work_ishtp_reset);
673 	cancel_work_sync(&client_data->work_ec_evt);
674 	cros_ish_deinit(cros_ish_cl);
675 	ishtp_put_device(cl_device);
676 }
677 
678 /**
679  * cros_ec_ishtp_reset() - ISHTP client driver reset callback
680  * @cl_device: ISHTP client device instance
681  *
682  * Return: 0
683  */
cros_ec_ishtp_reset(struct ishtp_cl_device * cl_device)684 static int cros_ec_ishtp_reset(struct ishtp_cl_device *cl_device)
685 {
686 	struct ishtp_cl	*cros_ish_cl = ishtp_get_drvdata(cl_device);
687 	struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
688 
689 	schedule_work(&client_data->work_ishtp_reset);
690 
691 	return 0;
692 }
693 
694 /**
695  * cros_ec_ishtp_suspend() - ISHTP client driver suspend callback
696  * @device: device instance
697  *
698  * Return: 0 for success, negative error code for failure.
699  */
cros_ec_ishtp_suspend(struct device * device)700 static int __maybe_unused cros_ec_ishtp_suspend(struct device *device)
701 {
702 	struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(device);
703 	struct ishtp_cl	*cros_ish_cl = ishtp_get_drvdata(cl_device);
704 	struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
705 
706 	return cros_ec_suspend(client_data->ec_dev);
707 }
708 
709 /**
710  * cros_ec_ishtp_resume() - ISHTP client driver resume callback
711  * @device: device instance
712  *
713  * Return: 0 for success, negative error code for failure.
714  */
cros_ec_ishtp_resume(struct device * device)715 static int __maybe_unused cros_ec_ishtp_resume(struct device *device)
716 {
717 	struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(device);
718 	struct ishtp_cl	*cros_ish_cl = ishtp_get_drvdata(cl_device);
719 	struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
720 
721 	return cros_ec_resume(client_data->ec_dev);
722 }
723 
724 static SIMPLE_DEV_PM_OPS(cros_ec_ishtp_pm_ops, cros_ec_ishtp_suspend,
725 			 cros_ec_ishtp_resume);
726 
727 static struct ishtp_cl_driver	cros_ec_ishtp_driver = {
728 	.name = "cros_ec_ishtp",
729 	.id = cros_ec_ishtp_id_table,
730 	.probe = cros_ec_ishtp_probe,
731 	.remove = cros_ec_ishtp_remove,
732 	.reset = cros_ec_ishtp_reset,
733 	.driver = {
734 		.pm = &cros_ec_ishtp_pm_ops,
735 	},
736 };
737 
cros_ec_ishtp_mod_init(void)738 static int __init cros_ec_ishtp_mod_init(void)
739 {
740 	return ishtp_cl_driver_register(&cros_ec_ishtp_driver, THIS_MODULE);
741 }
742 
cros_ec_ishtp_mod_exit(void)743 static void __exit cros_ec_ishtp_mod_exit(void)
744 {
745 	ishtp_cl_driver_unregister(&cros_ec_ishtp_driver);
746 }
747 
748 module_init(cros_ec_ishtp_mod_init);
749 module_exit(cros_ec_ishtp_mod_exit);
750 
751 MODULE_DESCRIPTION("ChromeOS EC ISHTP Client Driver");
752 MODULE_AUTHOR("Rushikesh S Kadam <rushikesh.s.kadam@intel.com>");
753 
754 MODULE_LICENSE("GPL v2");
755