1 /*
2  * ChromeOS EC multi-function device (SPI)
3  *
4  * Copyright (C) 2012 Google, Inc
5  *
6  * This software is licensed under the terms of the GNU General Public
7  * License version 2, as published by the Free Software Foundation, and
8  * may be copied, distributed, and modified under those terms.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  */
15 
16 #include <linux/delay.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/mfd/cros_ec.h>
20 #include <linux/mfd/cros_ec_commands.h>
21 #include <linux/of.h>
22 #include <linux/platform_device.h>
23 #include <linux/slab.h>
24 #include <linux/spi/spi.h>
25 
26 
27 /* The header byte, which follows the preamble */
28 #define EC_MSG_HEADER			0xec
29 
30 /*
31  * Number of EC preamble bytes we read at a time. Since it takes
32  * about 400-500us for the EC to respond there is not a lot of
33  * point in tuning this. If the EC could respond faster then
34  * we could increase this so that might expect the preamble and
35  * message to occur in a single transaction. However, the maximum
36  * SPI transfer size is 256 bytes, so at 5MHz we need a response
37  * time of perhaps <320us (200 bytes / 1600 bits).
38  */
39 #define EC_MSG_PREAMBLE_COUNT		32
40 
41 /*
42  * Allow for a long time for the EC to respond.  We support i2c
43  * tunneling and support fairly long messages for the tunnel (249
44  * bytes long at the moment).  If we're talking to a 100 kHz device
45  * on the other end and need to transfer ~256 bytes, then we need:
46  *  10 us/bit * ~10 bits/byte * ~256 bytes = ~25ms
47  *
48  * We'll wait 8 times that to handle clock stretching and other
49  * paranoia.  Note that some battery gas gauge ICs claim to have a
50  * clock stretch of 144ms in rare situations.  That's incentive for
51  * not directly passing i2c through, but it's too late for that for
52  * existing hardware.
53  *
54  * It's pretty unlikely that we'll really see a 249 byte tunnel in
55  * anything other than testing.  If this was more common we might
56  * consider having slow commands like this require a GET_STATUS
57  * wait loop.  The 'flash write' command would be another candidate
58  * for this, clocking in at 2-3ms.
59  */
60 #define EC_MSG_DEADLINE_MS		200
61 
62 /*
63   * Time between raising the SPI chip select (for the end of a
64   * transaction) and dropping it again (for the next transaction).
65   * If we go too fast, the EC will miss the transaction. We know that we
66   * need at least 70 us with the 16 MHz STM32 EC, so go with 200 us to be
67   * safe.
68   */
69 #define EC_SPI_RECOVERY_TIME_NS	(200 * 1000)
70 
71 /**
72  * struct cros_ec_spi - information about a SPI-connected EC
73  *
74  * @spi: SPI device we are connected to
75  * @last_transfer_ns: time that we last finished a transfer.
76  * @start_of_msg_delay: used to set the delay_usecs on the spi_transfer that
77  *      is sent when we want to turn on CS at the start of a transaction.
78  * @end_of_msg_delay: used to set the delay_usecs on the spi_transfer that
79  *      is sent when we want to turn off CS at the end of a transaction.
80  */
81 struct cros_ec_spi {
82 	struct spi_device *spi;
83 	s64 last_transfer_ns;
84 	unsigned int start_of_msg_delay;
85 	unsigned int end_of_msg_delay;
86 };
87 
88 static void debug_packet(struct device *dev, const char *name, u8 *ptr,
89 			 int len)
90 {
91 #ifdef DEBUG
92 	int i;
93 
94 	dev_dbg(dev, "%s: ", name);
95 	for (i = 0; i < len; i++)
96 		pr_cont(" %02x", ptr[i]);
97 
98 	pr_cont("\n");
99 #endif
100 }
101 
102 static int terminate_request(struct cros_ec_device *ec_dev)
103 {
104 	struct cros_ec_spi *ec_spi = ec_dev->priv;
105 	struct spi_message msg;
106 	struct spi_transfer trans;
107 	int ret;
108 
109 	/*
110 	 * Turn off CS, possibly adding a delay to ensure the rising edge
111 	 * doesn't come too soon after the end of the data.
112 	 */
113 	spi_message_init(&msg);
114 	memset(&trans, 0, sizeof(trans));
115 	trans.delay_usecs = ec_spi->end_of_msg_delay;
116 	spi_message_add_tail(&trans, &msg);
117 
118 	ret = spi_sync_locked(ec_spi->spi, &msg);
119 
120 	/* Reset end-of-response timer */
121 	ec_spi->last_transfer_ns = ktime_get_ns();
122 	if (ret < 0) {
123 		dev_err(ec_dev->dev,
124 			"cs-deassert spi transfer failed: %d\n",
125 			ret);
126 	}
127 
128 	return ret;
129 }
130 
131 /**
132  * receive_n_bytes - receive n bytes from the EC.
133  *
134  * Assumes buf is a pointer into the ec_dev->din buffer
135  */
136 static int receive_n_bytes(struct cros_ec_device *ec_dev, u8 *buf, int n)
137 {
138 	struct cros_ec_spi *ec_spi = ec_dev->priv;
139 	struct spi_transfer trans;
140 	struct spi_message msg;
141 	int ret;
142 
143 	BUG_ON(buf - ec_dev->din + n > ec_dev->din_size);
144 
145 	memset(&trans, 0, sizeof(trans));
146 	trans.cs_change = 1;
147 	trans.rx_buf = buf;
148 	trans.len = n;
149 
150 	spi_message_init(&msg);
151 	spi_message_add_tail(&trans, &msg);
152 	ret = spi_sync_locked(ec_spi->spi, &msg);
153 	if (ret < 0)
154 		dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
155 
156 	return ret;
157 }
158 
159 /**
160  * cros_ec_spi_receive_packet - Receive a packet from the EC.
161  *
162  * This function has two phases: reading the preamble bytes (since if we read
163  * data from the EC before it is ready to send, we just get preamble) and
164  * reading the actual message.
165  *
166  * The received data is placed into ec_dev->din.
167  *
168  * @ec_dev: ChromeOS EC device
169  * @need_len: Number of message bytes we need to read
170  */
171 static int cros_ec_spi_receive_packet(struct cros_ec_device *ec_dev,
172 				      int need_len)
173 {
174 	struct ec_host_response *response;
175 	u8 *ptr, *end;
176 	int ret;
177 	unsigned long deadline;
178 	int todo;
179 
180 	BUG_ON(ec_dev->din_size < EC_MSG_PREAMBLE_COUNT);
181 
182 	/* Receive data until we see the header byte */
183 	deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);
184 	while (true) {
185 		unsigned long start_jiffies = jiffies;
186 
187 		ret = receive_n_bytes(ec_dev,
188 				      ec_dev->din,
189 				      EC_MSG_PREAMBLE_COUNT);
190 		if (ret < 0)
191 			return ret;
192 
193 		ptr = ec_dev->din;
194 		for (end = ptr + EC_MSG_PREAMBLE_COUNT; ptr != end; ptr++) {
195 			if (*ptr == EC_SPI_FRAME_START) {
196 				dev_dbg(ec_dev->dev, "msg found at %zd\n",
197 					ptr - ec_dev->din);
198 				break;
199 			}
200 		}
201 		if (ptr != end)
202 			break;
203 
204 		/*
205 		 * Use the time at the start of the loop as a timeout.  This
206 		 * gives us one last shot at getting the transfer and is useful
207 		 * in case we got context switched out for a while.
208 		 */
209 		if (time_after(start_jiffies, deadline)) {
210 			dev_warn(ec_dev->dev, "EC failed to respond in time\n");
211 			return -ETIMEDOUT;
212 		}
213 	}
214 
215 	/*
216 	 * ptr now points to the header byte. Copy any valid data to the
217 	 * start of our buffer
218 	 */
219 	todo = end - ++ptr;
220 	BUG_ON(todo < 0 || todo > ec_dev->din_size);
221 	todo = min(todo, need_len);
222 	memmove(ec_dev->din, ptr, todo);
223 	ptr = ec_dev->din + todo;
224 	dev_dbg(ec_dev->dev, "need %d, got %d bytes from preamble\n",
225 		need_len, todo);
226 	need_len -= todo;
227 
228 	/* If the entire response struct wasn't read, get the rest of it. */
229 	if (todo < sizeof(*response)) {
230 		ret = receive_n_bytes(ec_dev, ptr, sizeof(*response) - todo);
231 		if (ret < 0)
232 			return -EBADMSG;
233 		ptr += (sizeof(*response) - todo);
234 		todo = sizeof(*response);
235 	}
236 
237 	response = (struct ec_host_response *)ec_dev->din;
238 
239 	/* Abort if data_len is too large. */
240 	if (response->data_len > ec_dev->din_size)
241 		return -EMSGSIZE;
242 
243 	/* Receive data until we have it all */
244 	while (need_len > 0) {
245 		/*
246 		 * We can't support transfers larger than the SPI FIFO size
247 		 * unless we have DMA. We don't have DMA on the ISP SPI ports
248 		 * for Exynos. We need a way of asking SPI driver for
249 		 * maximum-supported transfer size.
250 		 */
251 		todo = min(need_len, 256);
252 		dev_dbg(ec_dev->dev, "loop, todo=%d, need_len=%d, ptr=%zd\n",
253 			todo, need_len, ptr - ec_dev->din);
254 
255 		ret = receive_n_bytes(ec_dev, ptr, todo);
256 		if (ret < 0)
257 			return ret;
258 
259 		ptr += todo;
260 		need_len -= todo;
261 	}
262 
263 	dev_dbg(ec_dev->dev, "loop done, ptr=%zd\n", ptr - ec_dev->din);
264 
265 	return 0;
266 }
267 
268 /**
269  * cros_ec_spi_receive_response - Receive a response from the EC.
270  *
271  * This function has two phases: reading the preamble bytes (since if we read
272  * data from the EC before it is ready to send, we just get preamble) and
273  * reading the actual message.
274  *
275  * The received data is placed into ec_dev->din.
276  *
277  * @ec_dev: ChromeOS EC device
278  * @need_len: Number of message bytes we need to read
279  */
280 static int cros_ec_spi_receive_response(struct cros_ec_device *ec_dev,
281 					int need_len)
282 {
283 	u8 *ptr, *end;
284 	int ret;
285 	unsigned long deadline;
286 	int todo;
287 
288 	BUG_ON(ec_dev->din_size < EC_MSG_PREAMBLE_COUNT);
289 
290 	/* Receive data until we see the header byte */
291 	deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);
292 	while (true) {
293 		unsigned long start_jiffies = jiffies;
294 
295 		ret = receive_n_bytes(ec_dev,
296 				      ec_dev->din,
297 				      EC_MSG_PREAMBLE_COUNT);
298 		if (ret < 0)
299 			return ret;
300 
301 		ptr = ec_dev->din;
302 		for (end = ptr + EC_MSG_PREAMBLE_COUNT; ptr != end; ptr++) {
303 			if (*ptr == EC_SPI_FRAME_START) {
304 				dev_dbg(ec_dev->dev, "msg found at %zd\n",
305 					ptr - ec_dev->din);
306 				break;
307 			}
308 		}
309 		if (ptr != end)
310 			break;
311 
312 		/*
313 		 * Use the time at the start of the loop as a timeout.  This
314 		 * gives us one last shot at getting the transfer and is useful
315 		 * in case we got context switched out for a while.
316 		 */
317 		if (time_after(start_jiffies, deadline)) {
318 			dev_warn(ec_dev->dev, "EC failed to respond in time\n");
319 			return -ETIMEDOUT;
320 		}
321 	}
322 
323 	/*
324 	 * ptr now points to the header byte. Copy any valid data to the
325 	 * start of our buffer
326 	 */
327 	todo = end - ++ptr;
328 	BUG_ON(todo < 0 || todo > ec_dev->din_size);
329 	todo = min(todo, need_len);
330 	memmove(ec_dev->din, ptr, todo);
331 	ptr = ec_dev->din + todo;
332 	dev_dbg(ec_dev->dev, "need %d, got %d bytes from preamble\n",
333 		 need_len, todo);
334 	need_len -= todo;
335 
336 	/* Receive data until we have it all */
337 	while (need_len > 0) {
338 		/*
339 		 * We can't support transfers larger than the SPI FIFO size
340 		 * unless we have DMA. We don't have DMA on the ISP SPI ports
341 		 * for Exynos. We need a way of asking SPI driver for
342 		 * maximum-supported transfer size.
343 		 */
344 		todo = min(need_len, 256);
345 		dev_dbg(ec_dev->dev, "loop, todo=%d, need_len=%d, ptr=%zd\n",
346 			todo, need_len, ptr - ec_dev->din);
347 
348 		ret = receive_n_bytes(ec_dev, ptr, todo);
349 		if (ret < 0)
350 			return ret;
351 
352 		debug_packet(ec_dev->dev, "interim", ptr, todo);
353 		ptr += todo;
354 		need_len -= todo;
355 	}
356 
357 	dev_dbg(ec_dev->dev, "loop done, ptr=%zd\n", ptr - ec_dev->din);
358 
359 	return 0;
360 }
361 
362 /**
363  * cros_ec_pkt_xfer_spi - Transfer a packet over SPI and receive the reply
364  *
365  * @ec_dev: ChromeOS EC device
366  * @ec_msg: Message to transfer
367  */
368 static int cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev,
369 				struct cros_ec_command *ec_msg)
370 {
371 	struct ec_host_response *response;
372 	struct cros_ec_spi *ec_spi = ec_dev->priv;
373 	struct spi_transfer trans, trans_delay;
374 	struct spi_message msg;
375 	int i, len;
376 	u8 *ptr;
377 	u8 *rx_buf;
378 	u8 sum;
379 	u8 rx_byte;
380 	int ret = 0, final_ret;
381 	unsigned long delay;
382 
383 	len = cros_ec_prepare_tx(ec_dev, ec_msg);
384 	dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
385 
386 	/* If it's too soon to do another transaction, wait */
387 	delay = ktime_get_ns() - ec_spi->last_transfer_ns;
388 	if (delay < EC_SPI_RECOVERY_TIME_NS)
389 		ndelay(EC_SPI_RECOVERY_TIME_NS - delay);
390 
391 	rx_buf = kzalloc(len, GFP_KERNEL);
392 	if (!rx_buf)
393 		return -ENOMEM;
394 
395 	spi_bus_lock(ec_spi->spi->master);
396 
397 	/*
398 	 * Leave a gap between CS assertion and clocking of data to allow the
399 	 * EC time to wakeup.
400 	 */
401 	spi_message_init(&msg);
402 	if (ec_spi->start_of_msg_delay) {
403 		memset(&trans_delay, 0, sizeof(trans_delay));
404 		trans_delay.delay_usecs = ec_spi->start_of_msg_delay;
405 		spi_message_add_tail(&trans_delay, &msg);
406 	}
407 
408 	/* Transmit phase - send our message */
409 	memset(&trans, 0, sizeof(trans));
410 	trans.tx_buf = ec_dev->dout;
411 	trans.rx_buf = rx_buf;
412 	trans.len = len;
413 	trans.cs_change = 1;
414 	spi_message_add_tail(&trans, &msg);
415 	ret = spi_sync_locked(ec_spi->spi, &msg);
416 
417 	/* Get the response */
418 	if (!ret) {
419 		/* Verify that EC can process command */
420 		for (i = 0; i < len; i++) {
421 			rx_byte = rx_buf[i];
422 			/*
423 			 * Seeing the PAST_END, RX_BAD_DATA, or NOT_READY
424 			 * markers are all signs that the EC didn't fully
425 			 * receive our command. e.g., if the EC is flashing
426 			 * itself, it can't respond to any commands and instead
427 			 * clocks out EC_SPI_PAST_END from its SPI hardware
428 			 * buffer. Similar occurrences can happen if the AP is
429 			 * too slow to clock out data after asserting CS -- the
430 			 * EC will abort and fill its buffer with
431 			 * EC_SPI_RX_BAD_DATA.
432 			 *
433 			 * In all cases, these errors should be safe to retry.
434 			 * Report -EAGAIN and let the caller decide what to do
435 			 * about that.
436 			 */
437 			if (rx_byte == EC_SPI_PAST_END  ||
438 			    rx_byte == EC_SPI_RX_BAD_DATA ||
439 			    rx_byte == EC_SPI_NOT_READY) {
440 				ret = -EAGAIN;
441 				break;
442 			}
443 		}
444 	}
445 
446 	if (!ret)
447 		ret = cros_ec_spi_receive_packet(ec_dev,
448 				ec_msg->insize + sizeof(*response));
449 	else if (ret != -EAGAIN)
450 		dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
451 
452 	final_ret = terminate_request(ec_dev);
453 
454 	spi_bus_unlock(ec_spi->spi->master);
455 
456 	if (!ret)
457 		ret = final_ret;
458 	if (ret < 0)
459 		goto exit;
460 
461 	ptr = ec_dev->din;
462 
463 	/* check response error code */
464 	response = (struct ec_host_response *)ptr;
465 	ec_msg->result = response->result;
466 
467 	ret = cros_ec_check_result(ec_dev, ec_msg);
468 	if (ret)
469 		goto exit;
470 
471 	len = response->data_len;
472 	sum = 0;
473 	if (len > ec_msg->insize) {
474 		dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
475 			len, ec_msg->insize);
476 		ret = -EMSGSIZE;
477 		goto exit;
478 	}
479 
480 	for (i = 0; i < sizeof(*response); i++)
481 		sum += ptr[i];
482 
483 	/* copy response packet payload and compute checksum */
484 	memcpy(ec_msg->data, ptr + sizeof(*response), len);
485 	for (i = 0; i < len; i++)
486 		sum += ec_msg->data[i];
487 
488 	if (sum) {
489 		dev_err(ec_dev->dev,
490 			"bad packet checksum, calculated %x\n",
491 			sum);
492 		ret = -EBADMSG;
493 		goto exit;
494 	}
495 
496 	ret = len;
497 exit:
498 	kfree(rx_buf);
499 	if (ec_msg->command == EC_CMD_REBOOT_EC)
500 		msleep(EC_REBOOT_DELAY_MS);
501 
502 	return ret;
503 }
504 
505 /**
506  * cros_ec_cmd_xfer_spi - Transfer a message over SPI and receive the reply
507  *
508  * @ec_dev: ChromeOS EC device
509  * @ec_msg: Message to transfer
510  */
511 static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,
512 				struct cros_ec_command *ec_msg)
513 {
514 	struct cros_ec_spi *ec_spi = ec_dev->priv;
515 	struct spi_transfer trans;
516 	struct spi_message msg;
517 	int i, len;
518 	u8 *ptr;
519 	u8 *rx_buf;
520 	u8 rx_byte;
521 	int sum;
522 	int ret = 0, final_ret;
523 	unsigned long delay;
524 
525 	len = cros_ec_prepare_tx(ec_dev, ec_msg);
526 	dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
527 
528 	/* If it's too soon to do another transaction, wait */
529 	delay = ktime_get_ns() - ec_spi->last_transfer_ns;
530 	if (delay < EC_SPI_RECOVERY_TIME_NS)
531 		ndelay(EC_SPI_RECOVERY_TIME_NS - delay);
532 
533 	rx_buf = kzalloc(len, GFP_KERNEL);
534 	if (!rx_buf)
535 		return -ENOMEM;
536 
537 	spi_bus_lock(ec_spi->spi->master);
538 
539 	/* Transmit phase - send our message */
540 	debug_packet(ec_dev->dev, "out", ec_dev->dout, len);
541 	memset(&trans, 0, sizeof(trans));
542 	trans.tx_buf = ec_dev->dout;
543 	trans.rx_buf = rx_buf;
544 	trans.len = len;
545 	trans.cs_change = 1;
546 	spi_message_init(&msg);
547 	spi_message_add_tail(&trans, &msg);
548 	ret = spi_sync_locked(ec_spi->spi, &msg);
549 
550 	/* Get the response */
551 	if (!ret) {
552 		/* Verify that EC can process command */
553 		for (i = 0; i < len; i++) {
554 			rx_byte = rx_buf[i];
555 			/* See comments in cros_ec_pkt_xfer_spi() */
556 			if (rx_byte == EC_SPI_PAST_END  ||
557 			    rx_byte == EC_SPI_RX_BAD_DATA ||
558 			    rx_byte == EC_SPI_NOT_READY) {
559 				ret = -EAGAIN;
560 				break;
561 			}
562 		}
563 	}
564 
565 	if (!ret)
566 		ret = cros_ec_spi_receive_response(ec_dev,
567 				ec_msg->insize + EC_MSG_TX_PROTO_BYTES);
568 	else if (ret != -EAGAIN)
569 		dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
570 
571 	final_ret = terminate_request(ec_dev);
572 
573 	spi_bus_unlock(ec_spi->spi->master);
574 
575 	if (!ret)
576 		ret = final_ret;
577 	if (ret < 0)
578 		goto exit;
579 
580 	ptr = ec_dev->din;
581 
582 	/* check response error code */
583 	ec_msg->result = ptr[0];
584 	ret = cros_ec_check_result(ec_dev, ec_msg);
585 	if (ret)
586 		goto exit;
587 
588 	len = ptr[1];
589 	sum = ptr[0] + ptr[1];
590 	if (len > ec_msg->insize) {
591 		dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
592 			len, ec_msg->insize);
593 		ret = -ENOSPC;
594 		goto exit;
595 	}
596 
597 	/* copy response packet payload and compute checksum */
598 	for (i = 0; i < len; i++) {
599 		sum += ptr[i + 2];
600 		if (ec_msg->insize)
601 			ec_msg->data[i] = ptr[i + 2];
602 	}
603 	sum &= 0xff;
604 
605 	debug_packet(ec_dev->dev, "in", ptr, len + 3);
606 
607 	if (sum != ptr[len + 2]) {
608 		dev_err(ec_dev->dev,
609 			"bad packet checksum, expected %02x, got %02x\n",
610 			sum, ptr[len + 2]);
611 		ret = -EBADMSG;
612 		goto exit;
613 	}
614 
615 	ret = len;
616 exit:
617 	kfree(rx_buf);
618 	if (ec_msg->command == EC_CMD_REBOOT_EC)
619 		msleep(EC_REBOOT_DELAY_MS);
620 
621 	return ret;
622 }
623 
624 static void cros_ec_spi_dt_probe(struct cros_ec_spi *ec_spi, struct device *dev)
625 {
626 	struct device_node *np = dev->of_node;
627 	u32 val;
628 	int ret;
629 
630 	ret = of_property_read_u32(np, "google,cros-ec-spi-pre-delay", &val);
631 	if (!ret)
632 		ec_spi->start_of_msg_delay = val;
633 
634 	ret = of_property_read_u32(np, "google,cros-ec-spi-msg-delay", &val);
635 	if (!ret)
636 		ec_spi->end_of_msg_delay = val;
637 }
638 
639 static int cros_ec_spi_probe(struct spi_device *spi)
640 {
641 	struct device *dev = &spi->dev;
642 	struct cros_ec_device *ec_dev;
643 	struct cros_ec_spi *ec_spi;
644 	int err;
645 
646 	spi->bits_per_word = 8;
647 	spi->mode = SPI_MODE_0;
648 	err = spi_setup(spi);
649 	if (err < 0)
650 		return err;
651 
652 	ec_spi = devm_kzalloc(dev, sizeof(*ec_spi), GFP_KERNEL);
653 	if (ec_spi == NULL)
654 		return -ENOMEM;
655 	ec_spi->spi = spi;
656 	ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
657 	if (!ec_dev)
658 		return -ENOMEM;
659 
660 	/* Check for any DT properties */
661 	cros_ec_spi_dt_probe(ec_spi, dev);
662 
663 	spi_set_drvdata(spi, ec_dev);
664 	ec_dev->dev = dev;
665 	ec_dev->priv = ec_spi;
666 	ec_dev->irq = spi->irq;
667 	ec_dev->cmd_xfer = cros_ec_cmd_xfer_spi;
668 	ec_dev->pkt_xfer = cros_ec_pkt_xfer_spi;
669 	ec_dev->phys_name = dev_name(&ec_spi->spi->dev);
670 	ec_dev->din_size = EC_MSG_PREAMBLE_COUNT +
671 			   sizeof(struct ec_host_response) +
672 			   sizeof(struct ec_response_get_protocol_info);
673 	ec_dev->dout_size = sizeof(struct ec_host_request);
674 
675 	ec_spi->last_transfer_ns = ktime_get_ns();
676 
677 	err = cros_ec_register(ec_dev);
678 	if (err) {
679 		dev_err(dev, "cannot register EC\n");
680 		return err;
681 	}
682 
683 	device_init_wakeup(&spi->dev, true);
684 
685 	return 0;
686 }
687 
688 static int cros_ec_spi_remove(struct spi_device *spi)
689 {
690 	struct cros_ec_device *ec_dev;
691 
692 	ec_dev = spi_get_drvdata(spi);
693 	cros_ec_remove(ec_dev);
694 
695 	return 0;
696 }
697 
698 #ifdef CONFIG_PM_SLEEP
699 static int cros_ec_spi_suspend(struct device *dev)
700 {
701 	struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
702 
703 	return cros_ec_suspend(ec_dev);
704 }
705 
706 static int cros_ec_spi_resume(struct device *dev)
707 {
708 	struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
709 
710 	return cros_ec_resume(ec_dev);
711 }
712 #endif
713 
714 static SIMPLE_DEV_PM_OPS(cros_ec_spi_pm_ops, cros_ec_spi_suspend,
715 			 cros_ec_spi_resume);
716 
717 static const struct of_device_id cros_ec_spi_of_match[] = {
718 	{ .compatible = "google,cros-ec-spi", },
719 	{ /* sentinel */ },
720 };
721 MODULE_DEVICE_TABLE(of, cros_ec_spi_of_match);
722 
723 static const struct spi_device_id cros_ec_spi_id[] = {
724 	{ "cros-ec-spi", 0 },
725 	{ }
726 };
727 MODULE_DEVICE_TABLE(spi, cros_ec_spi_id);
728 
729 static struct spi_driver cros_ec_driver_spi = {
730 	.driver	= {
731 		.name	= "cros-ec-spi",
732 		.of_match_table = of_match_ptr(cros_ec_spi_of_match),
733 		.pm	= &cros_ec_spi_pm_ops,
734 	},
735 	.probe		= cros_ec_spi_probe,
736 	.remove		= cros_ec_spi_remove,
737 	.id_table	= cros_ec_spi_id,
738 };
739 
740 module_spi_driver(cros_ec_driver_spi);
741 
742 MODULE_LICENSE("GPL v2");
743 MODULE_DESCRIPTION("ChromeOS EC multi function device (SPI)");
744