1 // SPDX-License-Identifier: GPL-2.0
6 // ISHTP client driver for talking to the Chrome OS EC firmware running
8 // (ISH-TP).
15 #include <linux/intel-ish-client-if.h>
22  * The AP->ISH messages and corresponding ISH->AP responses are
25  * The MKBP ISH->AP events are serialized. We need one additional RX
33 	CROS_EC_COMMAND = 1,			/* AP->ISH message */
34 	CROS_MKBP_EVENT = 2,			/* ISH->AP events */
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.
74 #define cl_data_to_dev(client_data) ishtp_device((client_data)->cl_device)
77  * The Read-Write Semaphore is used to prevent message TX or RX while
78  * the ishtp client is being initialized or undergoing reset.
80  * The readers are the kernel function calls responsible for IA->ISH
81  * and ISH->AP messaging.
83  * The writers are .reset() and .probe() function.
88  * struct response_info - Encapsulate firmware response related
92  * @data: Copy the data received from firmware here.
95  * @size: Actual size of data received from firmware.
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.
112  * struct ishtp_cl_data - Encapsulate per ISH TP Client.
114  * @cros_ish_cl: ISHTP firmware client instance.
117  * @work_ishtp_reset: Work queue reset handling.
128 	 * Used for passing firmware response information between
139  * ish_evt_handler - ISH to AP event handler
147 	cros_ec_irq_thread(0, client_data->ec_dev);  in ish_evt_handler()
151  * ish_send() - Send message from host to firmware
154  * @out_msg: Message buffer to be sent to firmware
170 	struct ishtp_cl *cros_ish_cl = client_data->cros_ish_cl;  in ish_send()
174 		__func__, out_hdr->channel, out_hdr->status);  in ish_send()
177 	client_data->response.data = in_msg;  in ish_send()
178 	client_data->response.max_size = in_size;  in ish_send()
179 	client_data->response.error = 0;  in ish_send()
180 	client_data->response.token = next_token++;  in ish_send()
181 	client_data->response.received = false;  in ish_send()
183 	out_hdr->token = client_data->response.token;  in ish_send()
192 	wait_event_interruptible_timeout(client_data->response.wait_queue,  in ish_send()
193 					 client_data->response.received,  in ish_send()
195 	if (!client_data->response.received) {  in ish_send()
198 		return -ETIMEDOUT;  in ish_send()
201 	if (client_data->response.error < 0)  in ish_send()
202 		return client_data->response.error;  in ish_send()
204 	return client_data->response.size;  in ish_send()
208  * process_recv() - Received and parse incoming packet
220 	size_t data_len = rb_in_proc->buf_idx;  in process_recv()
225 		(struct cros_ish_in_msg *)rb_in_proc->buffer.data;  in process_recv()
227 	/* Proceed only if reset or init is not in progress */  in process_recv()
237 	 * All firmware messages contain a header. Check the buffer size  in process_recv()
240 	if (!rb_in_proc->buffer.data) {  in process_recv()
241 		dev_warn(dev, "rb_in_proc->buffer.data returned null");  in process_recv()
242 		client_data->response.error = -EBADMSG;  in process_recv()
249 		client_data->response.error = -EMSGSIZE;  in process_recv()
254 		in_msg->hdr.channel, in_msg->hdr.status);  in process_recv()
256 	switch (in_msg->hdr.channel) {  in process_recv()
258 		if (client_data->response.received) {  in process_recv()
260 				"Previous firmware message not yet processed\n");  in process_recv()
264 		if (client_data->response.token != in_msg->hdr.token) {  in process_recv()
267 					    in_msg->hdr.token);  in process_recv()
272 		if (!client_data->response.data) {  in process_recv()
275 			client_data->response.error = -EINVAL;  in process_recv()
279 		if (data_len > client_data->response.max_size) {  in process_recv()
282 				data_len, client_data->response.max_size);  in process_recv()
283 			client_data->response.error = -EMSGSIZE;  in process_recv()
287 		if (in_msg->hdr.status) {  in process_recv()
288 			dev_err(dev, "firmware returned status %d\n",  in process_recv()
289 				in_msg->hdr.status);  in process_recv()
290 			client_data->response.error = -EIO;  in process_recv()
295 		client_data->response.size = data_len;  in process_recv()
298 		 * Copy the buffer received in firmware response for the  in process_recv()
301 		memcpy(client_data->response.data,  in process_recv()
302 		       rb_in_proc->buffer.data, data_len);  in process_recv()
310 		client_data->response.received = true;  in process_recv()
313 		wake_up_interruptible(&client_data->response.wait_queue);  in process_recv()
325 		client_data->ec_dev->last_event_time = timestamp;  in process_recv()
326 		schedule_work(&client_data->work_ec_evt);  in process_recv()
331 		dev_err(dev, "Invalid channel=%02d\n", in_msg->hdr.channel);  in process_recv()
343  * ish_event_cb() - bus driver callback for incoming message
368  * cros_ish_init() - Init function for ISHTP client
370  * @reset: true if called from reset handler
376 static int cros_ish_init(struct ishtp_cl *cros_ish_cl, bool reset)  in cros_ish_init()  argument
385 					   reset);  in cros_ish_init()
392 	ishtp_register_event_cb(client_data->cl_device, ish_event_cb);  in cros_ish_init()
396 	ishtp_cl_destroy_connection(cros_ish_cl, reset);  in cros_ish_init()
401  * cros_ish_deinit() - Deinit function for ISHTP client
410 	/* Disband and free all Tx and Rx client-level rings */  in cros_ish_deinit()
415  * prepare_cros_ec_rx() - Check & prepare receive buffer
432 	msg->result = in_msg->ec_response.result;  in prepare_cros_ec_rx()
437 	if (in_msg->ec_response.data_len > msg->insize) {  in prepare_cros_ec_rx()
438 		dev_err(ec_dev->dev, "Packet too long (%d bytes, expected %d)",  in prepare_cros_ec_rx()
439 			in_msg->ec_response.data_len, msg->insize);  in prepare_cros_ec_rx()
440 		return -ENOSPC;  in prepare_cros_ec_rx()
448 	for (i = 0; i < in_msg->ec_response.data_len; i++)  in prepare_cros_ec_rx()
449 		sum += msg->data[i] = ((u8 *)in_msg)[offset + i];  in prepare_cros_ec_rx()
452 		dev_dbg(ec_dev->dev, "Bad received packet checksum %d\n", sum);  in prepare_cros_ec_rx()
453 		return -EBADMSG;  in prepare_cros_ec_rx()
463 	struct ishtp_cl *cros_ish_cl = ec_dev->priv;  in cros_ec_pkt_xfer_ish()
466 	struct cros_ish_in_msg *in_msg = (struct cros_ish_in_msg *)ec_dev->din;  in cros_ec_pkt_xfer_ish()
468 		(struct cros_ish_out_msg *)ec_dev->dout;  in cros_ec_pkt_xfer_ish()
469 	size_t in_size = sizeof(struct cros_ish_in_msg) + msg->insize;  in cros_ec_pkt_xfer_ish()
470 	size_t out_size = sizeof(struct cros_ish_out_msg) + msg->outsize;  in cros_ec_pkt_xfer_ish()
473 	if (in_size > ec_dev->din_size) {  in cros_ec_pkt_xfer_ish()
475 			"Incoming payload size %zu is too large for ec_dev->din_size %d\n",  in cros_ec_pkt_xfer_ish()
476 			in_size, ec_dev->din_size);  in cros_ec_pkt_xfer_ish()
477 		return -EMSGSIZE;  in cros_ec_pkt_xfer_ish()
480 	if (out_size > ec_dev->dout_size) {  in cros_ec_pkt_xfer_ish()
482 			"Outgoing payload size %zu is too large for ec_dev->dout_size %d\n",  in cros_ec_pkt_xfer_ish()
483 			out_size, ec_dev->dout_size);  in cros_ec_pkt_xfer_ish()
484 		return -EMSGSIZE;  in cros_ec_pkt_xfer_ish()
487 	/* Proceed only if reset-init is not in progress */  in cros_ec_pkt_xfer_ish()
491 		return -EAGAIN;  in cros_ec_pkt_xfer_ish()
495 	out_msg->hdr.channel = CROS_EC_COMMAND;  in cros_ec_pkt_xfer_ish()
496 	out_msg->hdr.status = 0;  in cros_ec_pkt_xfer_ish()
498 	ec_dev->dout += OUT_MSG_EC_REQUEST_PREAMBLE;  in cros_ec_pkt_xfer_ish()
502 	ec_dev->dout -= OUT_MSG_EC_REQUEST_PREAMBLE;  in cros_ec_pkt_xfer_ish()
506 		out_msg->ec_request.struct_version,  in cros_ec_pkt_xfer_ish()
507 		out_msg->ec_request.checksum,  in cros_ec_pkt_xfer_ish()
508 		out_msg->ec_request.command,  in cros_ec_pkt_xfer_ish()
509 		out_msg->ec_request.command_version,  in cros_ec_pkt_xfer_ish()
510 		out_msg->ec_request.data_len);  in cros_ec_pkt_xfer_ish()
512 	/* Send command to ISH EC firmware and read response */  in cros_ec_pkt_xfer_ish()
523 	rv = in_msg->ec_response.data_len;  in cros_ec_pkt_xfer_ish()
527 		in_msg->ec_response.struct_version,  in cros_ec_pkt_xfer_ish()
528 		in_msg->ec_response.checksum,  in cros_ec_pkt_xfer_ish()
529 		in_msg->ec_response.result,  in cros_ec_pkt_xfer_ish()
530 		in_msg->ec_response.data_len);  in cros_ec_pkt_xfer_ish()
533 	if (msg->command == EC_CMD_REBOOT_EC)  in cros_ec_pkt_xfer_ish()
548 		return -ENOMEM;  in cros_ec_dev_init()
550 	client_data->ec_dev = ec_dev;  in cros_ec_dev_init()
551 	dev->driver_data = ec_dev;  in cros_ec_dev_init()
553 	ec_dev->dev = dev;  in cros_ec_dev_init()
554 	ec_dev->priv = client_data->cros_ish_cl;  in cros_ec_dev_init()
555 	ec_dev->cmd_xfer = NULL;  in cros_ec_dev_init()
556 	ec_dev->pkt_xfer = cros_ec_pkt_xfer_ish;  in cros_ec_dev_init()
557 	ec_dev->phys_name = dev_name(dev);  in cros_ec_dev_init()
558 	ec_dev->din_size = sizeof(struct cros_ish_in_msg) +  in cros_ec_dev_init()
560 	ec_dev->dout_size = sizeof(struct cros_ish_out_msg);  in cros_ec_dev_init()
573 	/* Lock for reset to complete */  in reset_handler()
576 	cros_ish_cl = client_data->cros_ish_cl;  in reset_handler()
582 		dev_err(cl_data_to_dev(client_data), "Reset Failed\n");  in reset_handler()
588 	client_data->ec_dev->priv = client_data->cros_ish_cl;  in reset_handler()
590 	dev->driver_data = client_data->ec_dev;  in reset_handler()
592 	dev_info(cl_data_to_dev(client_data), "Chrome EC ISH reset done\n");  in reset_handler()
598  * cros_ec_ishtp_probe() - ISHTP client driver probe callback
611 		return -ENOMEM;  in cros_ec_ishtp_probe()
618 		rv = -ENOMEM;  in cros_ec_ishtp_probe()
624 	client_data->cros_ish_cl = cros_ish_cl;  in cros_ec_ishtp_probe()
625 	client_data->cl_device = cl_device;  in cros_ec_ishtp_probe()
627 	init_waitqueue_head(&client_data->response.wait_queue);  in cros_ec_ishtp_probe()
629 	INIT_WORK(&client_data->work_ishtp_reset,  in cros_ec_ishtp_probe()
631 	INIT_WORK(&client_data->work_ec_evt,  in cros_ec_ishtp_probe()
662  * cros_ec_ishtp_remove() - ISHTP client driver remove callback
672 	cancel_work_sync(&client_data->work_ishtp_reset);  in cros_ec_ishtp_remove()
673 	cancel_work_sync(&client_data->work_ec_evt);  in cros_ec_ishtp_remove()
679  * cros_ec_ishtp_reset() - ISHTP client driver reset callback
689 	schedule_work(&client_data->work_ishtp_reset);  in cros_ec_ishtp_reset()
695  * cros_ec_ishtp_suspend() - ISHTP client driver suspend callback
706 	return cros_ec_suspend(client_data->ec_dev);  in cros_ec_ishtp_suspend()
710  * cros_ec_ishtp_resume() - ISHTP client driver resume callback
721 	return cros_ec_resume(client_data->ec_dev);  in cros_ec_ishtp_resume()
732 	.reset = cros_ec_ishtp_reset,