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  1// SPDX-License-Identifier: GPL-2.0
  2// ISHTP interface for ChromeOS Embedded Controller
  3//
  4// Copyright (c) 2019, Intel Corporation.
  5//
  6// ISHTP client driver for talking to the Chrome OS EC firmware running
  7// on Intel Integrated Sensor Hub (ISH) using the ISH Transport protocol
  8// (ISH-TP).
  9
 10#include <linux/delay.h>
 11#include <linux/module.h>
 12#include <linux/pci.h>
 13#include <linux/platform_data/cros_ec_commands.h>
 14#include <linux/platform_data/cros_ec_proto.h>
 15#include <linux/intel-ish-client-if.h>
 16
 17#include "cros_ec.h"
 18
 19/*
 20 * ISH TX/RX ring buffer pool size
 21 *
 22 * The AP->ISH messages and corresponding ISH->AP responses are
 23 * serialized. We need 1 TX and 1 RX buffer for these.
 24 *
 25 * The MKBP ISH->AP events are serialized. We need one additional RX
 26 * buffer for them.
 27 */
 28#define CROS_ISH_CL_TX_RING_SIZE		8
 29#define CROS_ISH_CL_RX_RING_SIZE		8
 30
 31/* ISH CrOS EC Host Commands */
 32enum cros_ec_ish_channel {
 33	CROS_EC_COMMAND = 1,			/* AP->ISH message */
 34	CROS_MKBP_EVENT = 2,			/* ISH->AP events */
 35};
 36
 37/*
 38 * ISH firmware timeout for 1 message send failure is 1Hz, and the
 39 * firmware will retry 2 times, so 3Hz is used for timeout.
 40 */
 41#define ISHTP_SEND_TIMEOUT			(3 * HZ)
 42
 43/* ISH Transport CrOS EC ISH client unique GUID */
 44static const 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};
 49MODULE_DEVICE_TABLE(ishtp, cros_ec_ishtp_id_table);
 50
 51struct header {
 52	u8 channel;
 53	u8 status;
 54	u8 token;
 55	u8 reserved;
 56} __packed;
 57
 58struct cros_ish_out_msg {
 59	struct header hdr;
 60	struct ec_host_request ec_request;
 61} __packed;
 62
 63struct 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 */
 85static 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 */
101struct 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 */
123struct 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 */
142static 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 */
163static 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 */
217static 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
304error_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
334end_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 */
349static 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 *
371 * This function complete the initializtion of the client.
372 *
373 * Return: 0 for success, negative error code for failure.
374 */
375static int cros_ish_init(struct ishtp_cl *cros_ish_cl)
376{
377	int rv;
378	struct ishtp_device *dev;
379	struct ishtp_fw_client *fw_client;
380	struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
381
382	rv = ishtp_cl_link(cros_ish_cl);
383	if (rv) {
384		dev_err(cl_data_to_dev(client_data),
385			"ishtp_cl_link failed\n");
386		return rv;
387	}
388
389	dev = ishtp_get_ishtp_device(cros_ish_cl);
390
391	/* Connect to firmware client */
392	ishtp_set_tx_ring_size(cros_ish_cl, CROS_ISH_CL_TX_RING_SIZE);
393	ishtp_set_rx_ring_size(cros_ish_cl, CROS_ISH_CL_RX_RING_SIZE);
394
395	fw_client = ishtp_fw_cl_get_client(dev, &cros_ec_ishtp_id_table[0].guid);
396	if (!fw_client) {
397		dev_err(cl_data_to_dev(client_data),
398			"ish client uuid not found\n");
399		rv = -ENOENT;
400		goto err_cl_unlink;
401	}
402
403	ishtp_cl_set_fw_client_id(cros_ish_cl,
404				  ishtp_get_fw_client_id(fw_client));
405	ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_CONNECTING);
406
407	rv = ishtp_cl_connect(cros_ish_cl);
408	if (rv) {
409		dev_err(cl_data_to_dev(client_data),
410			"client connect fail\n");
411		goto err_cl_unlink;
412	}
413
414	ishtp_register_event_cb(client_data->cl_device, ish_event_cb);
415	return 0;
416
417err_cl_unlink:
418	ishtp_cl_unlink(cros_ish_cl);
419	return rv;
420}
421
422/**
423 * cros_ish_deinit() - Deinit function for ISHTP client
424 * @cros_ish_cl: ISHTP client instance
425 *
426 * Unlink and free cros_ec client
427 */
428static void cros_ish_deinit(struct ishtp_cl *cros_ish_cl)
429{
430	ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_DISCONNECTING);
431	ishtp_cl_disconnect(cros_ish_cl);
432	ishtp_cl_unlink(cros_ish_cl);
433	ishtp_cl_flush_queues(cros_ish_cl);
434
435	/* Disband and free all Tx and Rx client-level rings */
436	ishtp_cl_free(cros_ish_cl);
437}
438
439/**
440 * prepare_cros_ec_rx() - Check & prepare receive buffer
441 * @ec_dev: CrOS EC MFD device.
442 * @in_msg: Incoming message buffer
443 * @msg: cros_ec command used to send & receive data
444 *
445 * Return: 0 for success, negative error code for failure.
446 *
447 * Check the received buffer. Convert to cros_ec_command format.
448 */
449static int prepare_cros_ec_rx(struct cros_ec_device *ec_dev,
450			      const struct cros_ish_in_msg *in_msg,
451			      struct cros_ec_command *msg)
452{
453	u8 sum = 0;
454	int i, rv, offset;
455
456	/* Check response error code */
457	msg->result = in_msg->ec_response.result;
458	rv = cros_ec_check_result(ec_dev, msg);
459	if (rv < 0)
460		return rv;
461
462	if (in_msg->ec_response.data_len > msg->insize) {
463		dev_err(ec_dev->dev, "Packet too long (%d bytes, expected %d)",
464			in_msg->ec_response.data_len, msg->insize);
465		return -ENOSPC;
466	}
467
468	/* Copy response packet payload and compute checksum */
469	for (i = 0; i < sizeof(struct ec_host_response); i++)
470		sum += ((u8 *)in_msg)[IN_MSG_EC_RESPONSE_PREAMBLE + i];
471
472	offset = sizeof(struct cros_ish_in_msg);
473	for (i = 0; i < in_msg->ec_response.data_len; i++)
474		sum += msg->data[i] = ((u8 *)in_msg)[offset + i];
475
476	if (sum) {
477		dev_dbg(ec_dev->dev, "Bad received packet checksum %d\n", sum);
478		return -EBADMSG;
479	}
480
481	return 0;
482}
483
484static int cros_ec_pkt_xfer_ish(struct cros_ec_device *ec_dev,
485				struct cros_ec_command *msg)
486{
487	int rv;
488	struct ishtp_cl *cros_ish_cl = ec_dev->priv;
489	struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
490	struct device *dev = cl_data_to_dev(client_data);
491	struct cros_ish_in_msg *in_msg = (struct cros_ish_in_msg *)ec_dev->din;
492	struct cros_ish_out_msg *out_msg =
493		(struct cros_ish_out_msg *)ec_dev->dout;
494	size_t in_size = sizeof(struct cros_ish_in_msg) + msg->insize;
495	size_t out_size = sizeof(struct cros_ish_out_msg) + msg->outsize;
496
497	/* Sanity checks */
498	if (in_size > ec_dev->din_size) {
499		dev_err(dev,
500			"Incoming payload size %zu is too large for ec_dev->din_size %d\n",
501			in_size, ec_dev->din_size);
502		return -EMSGSIZE;
503	}
504
505	if (out_size > ec_dev->dout_size) {
506		dev_err(dev,
507			"Outgoing payload size %zu is too large for ec_dev->dout_size %d\n",
508			out_size, ec_dev->dout_size);
509		return -EMSGSIZE;
510	}
511
512	/* Proceed only if reset-init is not in progress */
513	if (!down_read_trylock(&init_lock)) {
514		dev_warn(dev,
515			 "Host is not ready to send messages to ISH. Try again\n");
516		return -EAGAIN;
517	}
518
519	/* Prepare the package to be sent over ISH TP */
520	out_msg->hdr.channel = CROS_EC_COMMAND;
521	out_msg->hdr.status = 0;
522
523	ec_dev->dout += OUT_MSG_EC_REQUEST_PREAMBLE;
524	rv = cros_ec_prepare_tx(ec_dev, msg);
525	if (rv < 0)
526		goto end_error;
527	ec_dev->dout -= OUT_MSG_EC_REQUEST_PREAMBLE;
528
529	dev_dbg(dev,
530		"out_msg: struct_ver=0x%x checksum=0x%x command=0x%x command_ver=0x%x data_len=0x%x\n",
531		out_msg->ec_request.struct_version,
532		out_msg->ec_request.checksum,
533		out_msg->ec_request.command,
534		out_msg->ec_request.command_version,
535		out_msg->ec_request.data_len);
536
537	/* Send command to ISH EC firmware and read response */
538	rv = ish_send(client_data,
539		      (u8 *)out_msg, out_size,
540		      (u8 *)in_msg, in_size);
541	if (rv < 0)
542		goto end_error;
543
544	rv = prepare_cros_ec_rx(ec_dev, in_msg, msg);
545	if (rv)
546		goto end_error;
547
548	rv = in_msg->ec_response.data_len;
549
550	dev_dbg(dev,
551		"in_msg: struct_ver=0x%x checksum=0x%x result=0x%x data_len=0x%x\n",
552		in_msg->ec_response.struct_version,
553		in_msg->ec_response.checksum,
554		in_msg->ec_response.result,
555		in_msg->ec_response.data_len);
556
557end_error:
558	if (msg->command == EC_CMD_REBOOT_EC)
559		msleep(EC_REBOOT_DELAY_MS);
560
561	up_read(&init_lock);
562
563	return rv;
564}
565
566static int cros_ec_dev_init(struct ishtp_cl_data *client_data)
567{
568	struct cros_ec_device *ec_dev;
569	struct device *dev = cl_data_to_dev(client_data);
570
571	ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
572	if (!ec_dev)
573		return -ENOMEM;
574
575	client_data->ec_dev = ec_dev;
576	dev->driver_data = ec_dev;
577
578	ec_dev->dev = dev;
579	ec_dev->priv = client_data->cros_ish_cl;
580	ec_dev->cmd_xfer = NULL;
581	ec_dev->pkt_xfer = cros_ec_pkt_xfer_ish;
582	ec_dev->phys_name = dev_name(dev);
583	ec_dev->din_size = sizeof(struct cros_ish_in_msg) +
584			   sizeof(struct ec_response_get_protocol_info);
585	ec_dev->dout_size = sizeof(struct cros_ish_out_msg);
586
587	return cros_ec_register(ec_dev);
588}
589
590static void reset_handler(struct work_struct *work)
591{
592	int rv;
593	struct device *dev;
594	struct ishtp_cl *cros_ish_cl;
595	struct ishtp_cl_device *cl_device;
596	struct ishtp_cl_data *client_data =
597		container_of(work, struct ishtp_cl_data, work_ishtp_reset);
598
599	/* Lock for reset to complete */
600	down_write(&init_lock);
601
602	cros_ish_cl = client_data->cros_ish_cl;
603	cl_device = client_data->cl_device;
604
605	/* Unlink, flush queues & start again */
606	ishtp_cl_unlink(cros_ish_cl);
607	ishtp_cl_flush_queues(cros_ish_cl);
608	ishtp_cl_free(cros_ish_cl);
609
610	cros_ish_cl = ishtp_cl_allocate(cl_device);
611	if (!cros_ish_cl) {
612		up_write(&init_lock);
613		return;
614	}
615
616	ishtp_set_drvdata(cl_device, cros_ish_cl);
617	ishtp_set_client_data(cros_ish_cl, client_data);
618	client_data->cros_ish_cl = cros_ish_cl;
619
620	rv = cros_ish_init(cros_ish_cl);
621	if (rv) {
622		ishtp_cl_free(cros_ish_cl);
623		dev_err(cl_data_to_dev(client_data), "Reset Failed\n");
624		up_write(&init_lock);
625		return;
626	}
627
628	/* Refresh ec_dev device pointers */
629	client_data->ec_dev->priv = client_data->cros_ish_cl;
630	dev = cl_data_to_dev(client_data);
631	dev->driver_data = client_data->ec_dev;
632
633	dev_info(cl_data_to_dev(client_data), "Chrome EC ISH reset done\n");
634
635	up_write(&init_lock);
636}
637
638/**
639 * cros_ec_ishtp_probe() - ISHTP client driver probe callback
640 * @cl_device: ISHTP client device instance
641 *
642 * Return: 0 for success, negative error code for failure.
643 */
644static int cros_ec_ishtp_probe(struct ishtp_cl_device *cl_device)
645{
646	int rv;
647	struct ishtp_cl *cros_ish_cl;
648	struct ishtp_cl_data *client_data =
649		devm_kzalloc(ishtp_device(cl_device),
650			     sizeof(*client_data), GFP_KERNEL);
651	if (!client_data)
652		return -ENOMEM;
653
654	/* Lock for initialization to complete */
655	down_write(&init_lock);
656
657	cros_ish_cl = ishtp_cl_allocate(cl_device);
658	if (!cros_ish_cl) {
659		rv = -ENOMEM;
660		goto end_ishtp_cl_alloc_error;
661	}
662
663	ishtp_set_drvdata(cl_device, cros_ish_cl);
664	ishtp_set_client_data(cros_ish_cl, client_data);
665	client_data->cros_ish_cl = cros_ish_cl;
666	client_data->cl_device = cl_device;
667
668	init_waitqueue_head(&client_data->response.wait_queue);
669
670	INIT_WORK(&client_data->work_ishtp_reset,
671		  reset_handler);
672	INIT_WORK(&client_data->work_ec_evt,
673		  ish_evt_handler);
674
675	rv = cros_ish_init(cros_ish_cl);
676	if (rv)
677		goto end_ishtp_cl_init_error;
678
679	ishtp_get_device(cl_device);
680
681	up_write(&init_lock);
682
683	/* Register croc_ec_dev mfd */
684	rv = cros_ec_dev_init(client_data);
685	if (rv) {
686		down_write(&init_lock);
687		goto end_cros_ec_dev_init_error;
688	}
689
690	return 0;
691
692end_cros_ec_dev_init_error:
693	ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_DISCONNECTING);
694	ishtp_cl_disconnect(cros_ish_cl);
695	ishtp_cl_unlink(cros_ish_cl);
696	ishtp_cl_flush_queues(cros_ish_cl);
697	ishtp_put_device(cl_device);
698end_ishtp_cl_init_error:
699	ishtp_cl_free(cros_ish_cl);
700end_ishtp_cl_alloc_error:
701	up_write(&init_lock);
702	return rv;
703}
704
705/**
706 * cros_ec_ishtp_remove() - ISHTP client driver remove callback
707 * @cl_device: ISHTP client device instance
708 *
709 * Return: 0
710 */
711static void cros_ec_ishtp_remove(struct ishtp_cl_device *cl_device)
712{
713	struct ishtp_cl	*cros_ish_cl = ishtp_get_drvdata(cl_device);
714	struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
715
716	cancel_work_sync(&client_data->work_ishtp_reset);
717	cancel_work_sync(&client_data->work_ec_evt);
718	cros_ish_deinit(cros_ish_cl);
719	ishtp_put_device(cl_device);
720}
721
722/**
723 * cros_ec_ishtp_reset() - ISHTP client driver reset callback
724 * @cl_device: ISHTP client device instance
725 *
726 * Return: 0
727 */
728static int cros_ec_ishtp_reset(struct ishtp_cl_device *cl_device)
729{
730	struct ishtp_cl	*cros_ish_cl = ishtp_get_drvdata(cl_device);
731	struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
732
733	schedule_work(&client_data->work_ishtp_reset);
734
735	return 0;
736}
737
738/**
739 * cros_ec_ishtp_suspend() - ISHTP client driver suspend callback
740 * @device: device instance
741 *
742 * Return: 0 for success, negative error code for failure.
743 */
744static int __maybe_unused cros_ec_ishtp_suspend(struct device *device)
745{
746	struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(device);
747	struct ishtp_cl	*cros_ish_cl = ishtp_get_drvdata(cl_device);
748	struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
749
750	return cros_ec_suspend(client_data->ec_dev);
751}
752
753/**
754 * cros_ec_ishtp_resume() - ISHTP client driver resume callback
755 * @device: device instance
756 *
757 * Return: 0 for success, negative error code for failure.
758 */
759static int __maybe_unused cros_ec_ishtp_resume(struct device *device)
760{
761	struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(device);
762	struct ishtp_cl	*cros_ish_cl = ishtp_get_drvdata(cl_device);
763	struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
764
765	return cros_ec_resume(client_data->ec_dev);
766}
767
768static SIMPLE_DEV_PM_OPS(cros_ec_ishtp_pm_ops, cros_ec_ishtp_suspend,
769			 cros_ec_ishtp_resume);
770
771static struct ishtp_cl_driver	cros_ec_ishtp_driver = {
772	.name = "cros_ec_ishtp",
773	.id = cros_ec_ishtp_id_table,
774	.probe = cros_ec_ishtp_probe,
775	.remove = cros_ec_ishtp_remove,
776	.reset = cros_ec_ishtp_reset,
777	.driver = {
778		.pm = &cros_ec_ishtp_pm_ops,
779	},
780};
781
782static int __init cros_ec_ishtp_mod_init(void)
783{
784	return ishtp_cl_driver_register(&cros_ec_ishtp_driver, THIS_MODULE);
785}
786
787static void __exit cros_ec_ishtp_mod_exit(void)
788{
789	ishtp_cl_driver_unregister(&cros_ec_ishtp_driver);
790}
791
792module_init(cros_ec_ishtp_mod_init);
793module_exit(cros_ec_ishtp_mod_exit);
794
795MODULE_DESCRIPTION("ChromeOS EC ISHTP Client Driver");
796MODULE_AUTHOR("Rushikesh S Kadam <rushikesh.s.kadam@intel.com>");
797
798MODULE_LICENSE("GPL v2");