1 // SPDX-License-Identifier: GPL-2.0
2 // ISHTP interface for ChromeOS Embedded Controller
4 // Copyright (c) 2019, Intel Corporation.
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
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>
20 * ISH TX/RX ring buffer pool size
22 * The AP->ISH messages and corresponding ISH->AP responses are
23 * serialized. We need 1 TX and 1 RX buffer for these.
25 * The MKBP ISH->AP events are serialized. We need one additional RX
28 #define CROS_ISH_CL_TX_RING_SIZE 8
29 #define CROS_ISH_CL_RX_RING_SIZE 8
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 */
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.
41 #define ISHTP_SEND_TIMEOUT (3 * HZ)
43 /* ISH Transport CrOS EC ISH client unique GUID */
44 static const guid_t cros_ish_guid =
45 GUID_INIT(0x7b7154d0, 0x56f4, 0x4bdc,
46 0xb0, 0xd8, 0x9e, 0x7c, 0xda, 0xe0, 0xd6, 0xa0);
54 struct cros_ish_out_msg {
56 struct ec_host_request ec_request;
59 struct cros_ish_in_msg {
61 struct ec_host_response ec_response;
64 #define IN_MSG_EC_RESPONSE_PREAMBLE \
65 offsetof(struct cros_ish_in_msg, ec_response)
67 #define OUT_MSG_EC_REQUEST_PREAMBLE \
68 offsetof(struct cros_ish_out_msg, ec_request)
70 #define cl_data_to_dev(client_data) ishtp_device((client_data)->cl_device)
73 * The Read-Write Semaphore is used to prevent message TX or RX while
74 * the ishtp client is being initialized or undergoing reset.
76 * The readers are the kernel function calls responsible for IA->ISH
77 * and ISH->AP messaging.
79 * The writers are .reset() and .probe() function.
81 static DECLARE_RWSEM(init_lock);
84 * struct response_info - Encapsulate firmware response related
85 * information for passing between function ish_send() and
86 * process_recv() callback.
88 * @data: Copy the data received from firmware here.
89 * @max_size: Max size allocated for the @data buffer. If the received
90 * data exceeds this value, we log an error.
91 * @size: Actual size of data received from firmware.
92 * @error: 0 for success, negative error code for a failure in process_recv().
93 * @received: Set to true on receiving a valid firmware response to host command
94 * @wait_queue: Wait queue for host to wait for firmware response.
96 struct response_info {
102 wait_queue_head_t wait_queue;
106 * struct ishtp_cl_data - Encapsulate per ISH TP Client.
108 * @cros_ish_cl: ISHTP firmware client instance.
109 * @cl_device: ISHTP client device instance.
110 * @response: Response info passing between ish_send() and process_recv().
111 * @work_ishtp_reset: Work queue reset handling.
112 * @work_ec_evt: Work queue for EC events.
113 * @ec_dev: CrOS EC MFD device.
115 * This structure is used to store per client data.
117 struct ishtp_cl_data {
118 struct ishtp_cl *cros_ish_cl;
119 struct ishtp_cl_device *cl_device;
122 * Used for passing firmware response information between
123 * ish_send() and process_recv() callback.
125 struct response_info response;
127 struct work_struct work_ishtp_reset;
128 struct work_struct work_ec_evt;
129 struct cros_ec_device *ec_dev;
133 * ish_evt_handler - ISH to AP event handler
136 static void ish_evt_handler(struct work_struct *work)
138 struct ishtp_cl_data *client_data =
139 container_of(work, struct ishtp_cl_data, work_ec_evt);
140 struct cros_ec_device *ec_dev = client_data->ec_dev;
141 bool ec_has_more_events;
144 ec_has_more_events = cros_ec_handle_event(ec_dev);
145 } while (ec_has_more_events);
149 * ish_send() - Send message from host to firmware
151 * @client_data: Client data instance
152 * @out_msg: Message buffer to be sent to firmware
153 * @out_size: Size of out going message
154 * @in_msg: Message buffer where the incoming data is copied. This buffer
155 * is allocated by calling
156 * @in_size: Max size of incoming message
158 * Return: Number of bytes copied in the in_msg on success, negative
159 * error code on failure.
161 static int ish_send(struct ishtp_cl_data *client_data,
162 u8 *out_msg, size_t out_size,
163 u8 *in_msg, size_t in_size)
166 struct header *out_hdr = (struct header *)out_msg;
167 struct ishtp_cl *cros_ish_cl = client_data->cros_ish_cl;
169 dev_dbg(cl_data_to_dev(client_data),
170 "%s: channel=%02u status=%02u\n",
171 __func__, out_hdr->channel, out_hdr->status);
173 /* Setup for incoming response */
174 client_data->response.data = in_msg;
175 client_data->response.max_size = in_size;
176 client_data->response.error = 0;
177 client_data->response.received = false;
179 rv = ishtp_cl_send(cros_ish_cl, out_msg, out_size);
181 dev_err(cl_data_to_dev(client_data),
182 "ishtp_cl_send error %d\n", rv);
186 wait_event_interruptible_timeout(client_data->response.wait_queue,
187 client_data->response.received,
189 if (!client_data->response.received) {
190 dev_err(cl_data_to_dev(client_data),
191 "Timed out for response to host message\n");
195 if (client_data->response.error < 0)
196 return client_data->response.error;
198 return client_data->response.size;
202 * process_recv() - Received and parse incoming packet
203 * @cros_ish_cl: Client instance to get stats
204 * @rb_in_proc: Host interface message buffer
205 * @timestamp: Timestamp of when parent callback started
207 * Parse the incoming packet. If it is a response packet then it will
208 * update per instance flags and wake up the caller waiting to for the
209 * response. If it is an event packet then it will schedule event work.
211 static void process_recv(struct ishtp_cl *cros_ish_cl,
212 struct ishtp_cl_rb *rb_in_proc, ktime_t timestamp)
214 size_t data_len = rb_in_proc->buf_idx;
215 struct ishtp_cl_data *client_data =
216 ishtp_get_client_data(cros_ish_cl);
217 struct device *dev = cl_data_to_dev(client_data);
218 struct cros_ish_in_msg *in_msg =
219 (struct cros_ish_in_msg *)rb_in_proc->buffer.data;
221 /* Proceed only if reset or init is not in progress */
222 if (!down_read_trylock(&init_lock)) {
223 /* Free the buffer */
224 ishtp_cl_io_rb_recycle(rb_in_proc);
226 "Host is not ready to receive incoming messages\n");
231 * All firmware messages contain a header. Check the buffer size
232 * before accessing elements inside.
234 if (!rb_in_proc->buffer.data) {
235 dev_warn(dev, "rb_in_proc->buffer.data returned null");
236 client_data->response.error = -EBADMSG;
240 if (data_len < sizeof(struct header)) {
241 dev_err(dev, "data size %zu is less than header %zu\n",
242 data_len, sizeof(struct header));
243 client_data->response.error = -EMSGSIZE;
247 dev_dbg(dev, "channel=%02u status=%02u\n",
248 in_msg->hdr.channel, in_msg->hdr.status);
250 switch (in_msg->hdr.channel) {
251 case CROS_EC_COMMAND:
253 if (!client_data->response.data) {
255 "Receiving buffer is null. Should be allocated by calling function\n");
256 client_data->response.error = -EINVAL;
260 if (client_data->response.received) {
262 "Previous firmware message not yet processed\n");
263 client_data->response.error = -EINVAL;
267 if (data_len > client_data->response.max_size) {
269 "Received buffer size %zu is larger than allocated buffer %zu\n",
270 data_len, client_data->response.max_size);
271 client_data->response.error = -EMSGSIZE;
275 if (in_msg->hdr.status) {
276 dev_err(dev, "firmware returned status %d\n",
278 client_data->response.error = -EIO;
282 /* Update the actual received buffer size */
283 client_data->response.size = data_len;
286 * Copy the buffer received in firmware response for the
289 memcpy(client_data->response.data,
290 rb_in_proc->buffer.data, data_len);
292 /* Set flag before waking up the caller */
293 client_data->response.received = true;
295 /* Wake the calling thread */
296 wake_up_interruptible(&client_data->response.wait_queue);
300 case CROS_MKBP_EVENT:
302 * Set timestamp from beginning of function since we actually
303 * got an incoming MKBP event
305 client_data->ec_dev->last_event_time = timestamp;
306 /* The event system doesn't send any data in buffer */
307 schedule_work(&client_data->work_ec_evt);
312 dev_err(dev, "Invalid channel=%02d\n", in_msg->hdr.channel);
316 /* Free the buffer */
317 ishtp_cl_io_rb_recycle(rb_in_proc);
323 * ish_event_cb() - bus driver callback for incoming message
324 * @cl_device: ISHTP client device for which this message is targeted.
326 * Remove the packet from the list and process the message by calling
329 static void ish_event_cb(struct ishtp_cl_device *cl_device)
331 struct ishtp_cl_rb *rb_in_proc;
332 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
336 * Take timestamp as close to hardware interrupt as possible for sensor
339 timestamp = cros_ec_get_time_ns();
341 while ((rb_in_proc = ishtp_cl_rx_get_rb(cros_ish_cl)) != NULL) {
342 /* Decide what to do with received data */
343 process_recv(cros_ish_cl, rb_in_proc, timestamp);
348 * cros_ish_init() - Init function for ISHTP client
349 * @cros_ish_cl: ISHTP client instance
351 * This function complete the initializtion of the client.
353 * Return: 0 for success, negative error code for failure.
355 static int cros_ish_init(struct ishtp_cl *cros_ish_cl)
358 struct ishtp_device *dev;
359 struct ishtp_fw_client *fw_client;
360 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
362 rv = ishtp_cl_link(cros_ish_cl);
364 dev_err(cl_data_to_dev(client_data),
365 "ishtp_cl_link failed\n");
369 dev = ishtp_get_ishtp_device(cros_ish_cl);
371 /* Connect to firmware client */
372 ishtp_set_tx_ring_size(cros_ish_cl, CROS_ISH_CL_TX_RING_SIZE);
373 ishtp_set_rx_ring_size(cros_ish_cl, CROS_ISH_CL_RX_RING_SIZE);
375 fw_client = ishtp_fw_cl_get_client(dev, &cros_ish_guid);
377 dev_err(cl_data_to_dev(client_data),
378 "ish client uuid not found\n");
383 ishtp_cl_set_fw_client_id(cros_ish_cl,
384 ishtp_get_fw_client_id(fw_client));
385 ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_CONNECTING);
387 rv = ishtp_cl_connect(cros_ish_cl);
389 dev_err(cl_data_to_dev(client_data),
390 "client connect fail\n");
394 ishtp_register_event_cb(client_data->cl_device, ish_event_cb);
398 ishtp_cl_unlink(cros_ish_cl);
403 * cros_ish_deinit() - Deinit function for ISHTP client
404 * @cros_ish_cl: ISHTP client instance
406 * Unlink and free cros_ec client
408 static void cros_ish_deinit(struct ishtp_cl *cros_ish_cl)
410 ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_DISCONNECTING);
411 ishtp_cl_disconnect(cros_ish_cl);
412 ishtp_cl_unlink(cros_ish_cl);
413 ishtp_cl_flush_queues(cros_ish_cl);
415 /* Disband and free all Tx and Rx client-level rings */
416 ishtp_cl_free(cros_ish_cl);
420 * prepare_cros_ec_rx() - Check & prepare receive buffer
421 * @ec_dev: CrOS EC MFD device.
422 * @in_msg: Incoming message buffer
423 * @msg: cros_ec command used to send & receive data
425 * Return: 0 for success, negative error code for failure.
427 * Check the received buffer. Convert to cros_ec_command format.
429 static int prepare_cros_ec_rx(struct cros_ec_device *ec_dev,
430 const struct cros_ish_in_msg *in_msg,
431 struct cros_ec_command *msg)
436 /* Check response error code */
437 msg->result = in_msg->ec_response.result;
438 rv = cros_ec_check_result(ec_dev, msg);
442 if (in_msg->ec_response.data_len > msg->insize) {
443 dev_err(ec_dev->dev, "Packet too long (%d bytes, expected %d)",
444 in_msg->ec_response.data_len, msg->insize);
448 /* Copy response packet payload and compute checksum */
449 for (i = 0; i < sizeof(struct ec_host_response); i++)
450 sum += ((u8 *)in_msg)[IN_MSG_EC_RESPONSE_PREAMBLE + i];
452 offset = sizeof(struct cros_ish_in_msg);
453 for (i = 0; i < in_msg->ec_response.data_len; i++)
454 sum += msg->data[i] = ((u8 *)in_msg)[offset + i];
457 dev_dbg(ec_dev->dev, "Bad received packet checksum %d\n", sum);
464 static int cros_ec_pkt_xfer_ish(struct cros_ec_device *ec_dev,
465 struct cros_ec_command *msg)
468 struct ishtp_cl *cros_ish_cl = ec_dev->priv;
469 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
470 struct device *dev = cl_data_to_dev(client_data);
471 struct cros_ish_in_msg *in_msg = (struct cros_ish_in_msg *)ec_dev->din;
472 struct cros_ish_out_msg *out_msg =
473 (struct cros_ish_out_msg *)ec_dev->dout;
474 size_t in_size = sizeof(struct cros_ish_in_msg) + msg->insize;
475 size_t out_size = sizeof(struct cros_ish_out_msg) + msg->outsize;
478 if (in_size > ec_dev->din_size) {
480 "Incoming payload size %zu is too large for ec_dev->din_size %d\n",
481 in_size, ec_dev->din_size);
485 if (out_size > ec_dev->dout_size) {
487 "Outgoing payload size %zu is too large for ec_dev->dout_size %d\n",
488 out_size, ec_dev->dout_size);
492 /* Proceed only if reset-init is not in progress */
493 if (!down_read_trylock(&init_lock)) {
495 "Host is not ready to send messages to ISH. Try again\n");
499 /* Prepare the package to be sent over ISH TP */
500 out_msg->hdr.channel = CROS_EC_COMMAND;
501 out_msg->hdr.status = 0;
503 ec_dev->dout += OUT_MSG_EC_REQUEST_PREAMBLE;
504 cros_ec_prepare_tx(ec_dev, msg);
505 ec_dev->dout -= OUT_MSG_EC_REQUEST_PREAMBLE;
508 "out_msg: struct_ver=0x%x checksum=0x%x command=0x%x command_ver=0x%x data_len=0x%x\n",
509 out_msg->ec_request.struct_version,
510 out_msg->ec_request.checksum,
511 out_msg->ec_request.command,
512 out_msg->ec_request.command_version,
513 out_msg->ec_request.data_len);
515 /* Send command to ISH EC firmware and read response */
516 rv = ish_send(client_data,
517 (u8 *)out_msg, out_size,
518 (u8 *)in_msg, in_size);
522 rv = prepare_cros_ec_rx(ec_dev, in_msg, msg);
526 rv = in_msg->ec_response.data_len;
529 "in_msg: struct_ver=0x%x checksum=0x%x result=0x%x data_len=0x%x\n",
530 in_msg->ec_response.struct_version,
531 in_msg->ec_response.checksum,
532 in_msg->ec_response.result,
533 in_msg->ec_response.data_len);
536 if (msg->command == EC_CMD_REBOOT_EC)
537 msleep(EC_REBOOT_DELAY_MS);
544 static int cros_ec_dev_init(struct ishtp_cl_data *client_data)
546 struct cros_ec_device *ec_dev;
547 struct device *dev = cl_data_to_dev(client_data);
549 ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
553 client_data->ec_dev = ec_dev;
554 dev->driver_data = ec_dev;
557 ec_dev->priv = client_data->cros_ish_cl;
558 ec_dev->cmd_xfer = NULL;
559 ec_dev->pkt_xfer = cros_ec_pkt_xfer_ish;
560 ec_dev->phys_name = dev_name(dev);
561 ec_dev->din_size = sizeof(struct cros_ish_in_msg) +
562 sizeof(struct ec_response_get_protocol_info);
563 ec_dev->dout_size = sizeof(struct cros_ish_out_msg);
565 return cros_ec_register(ec_dev);
568 static void reset_handler(struct work_struct *work)
572 struct ishtp_cl *cros_ish_cl;
573 struct ishtp_cl_device *cl_device;
574 struct ishtp_cl_data *client_data =
575 container_of(work, struct ishtp_cl_data, work_ishtp_reset);
577 /* Lock for reset to complete */
578 down_write(&init_lock);
580 cros_ish_cl = client_data->cros_ish_cl;
581 cl_device = client_data->cl_device;
583 /* Unlink, flush queues & start again */
584 ishtp_cl_unlink(cros_ish_cl);
585 ishtp_cl_flush_queues(cros_ish_cl);
586 ishtp_cl_free(cros_ish_cl);
588 cros_ish_cl = ishtp_cl_allocate(cl_device);
590 up_write(&init_lock);
594 ishtp_set_drvdata(cl_device, cros_ish_cl);
595 ishtp_set_client_data(cros_ish_cl, client_data);
596 client_data->cros_ish_cl = cros_ish_cl;
598 rv = cros_ish_init(cros_ish_cl);
600 ishtp_cl_free(cros_ish_cl);
601 dev_err(cl_data_to_dev(client_data), "Reset Failed\n");
602 up_write(&init_lock);
606 /* Refresh ec_dev device pointers */
607 client_data->ec_dev->priv = client_data->cros_ish_cl;
608 dev = cl_data_to_dev(client_data);
609 dev->driver_data = client_data->ec_dev;
611 dev_info(cl_data_to_dev(client_data), "Chrome EC ISH reset done\n");
613 up_write(&init_lock);
617 * cros_ec_ishtp_probe() - ISHTP client driver probe callback
618 * @cl_device: ISHTP client device instance
620 * Return: 0 for success, negative error code for failure.
622 static int cros_ec_ishtp_probe(struct ishtp_cl_device *cl_device)
625 struct ishtp_cl *cros_ish_cl;
626 struct ishtp_cl_data *client_data =
627 devm_kzalloc(ishtp_device(cl_device),
628 sizeof(*client_data), GFP_KERNEL);
632 /* Lock for initialization to complete */
633 down_write(&init_lock);
635 cros_ish_cl = ishtp_cl_allocate(cl_device);
638 goto end_ishtp_cl_alloc_error;
641 ishtp_set_drvdata(cl_device, cros_ish_cl);
642 ishtp_set_client_data(cros_ish_cl, client_data);
643 client_data->cros_ish_cl = cros_ish_cl;
644 client_data->cl_device = cl_device;
646 init_waitqueue_head(&client_data->response.wait_queue);
648 INIT_WORK(&client_data->work_ishtp_reset,
650 INIT_WORK(&client_data->work_ec_evt,
653 rv = cros_ish_init(cros_ish_cl);
655 goto end_ishtp_cl_init_error;
657 ishtp_get_device(cl_device);
659 up_write(&init_lock);
661 /* Register croc_ec_dev mfd */
662 rv = cros_ec_dev_init(client_data);
664 goto end_cros_ec_dev_init_error;
668 end_cros_ec_dev_init_error:
669 ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_DISCONNECTING);
670 ishtp_cl_disconnect(cros_ish_cl);
671 ishtp_cl_unlink(cros_ish_cl);
672 ishtp_cl_flush_queues(cros_ish_cl);
673 ishtp_put_device(cl_device);
674 end_ishtp_cl_init_error:
675 ishtp_cl_free(cros_ish_cl);
676 end_ishtp_cl_alloc_error:
677 up_write(&init_lock);
682 * cros_ec_ishtp_remove() - ISHTP client driver remove callback
683 * @cl_device: ISHTP client device instance
687 static int cros_ec_ishtp_remove(struct ishtp_cl_device *cl_device)
689 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
690 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
692 cancel_work_sync(&client_data->work_ishtp_reset);
693 cancel_work_sync(&client_data->work_ec_evt);
694 cros_ish_deinit(cros_ish_cl);
695 ishtp_put_device(cl_device);
701 * cros_ec_ishtp_reset() - ISHTP client driver reset callback
702 * @cl_device: ISHTP client device instance
706 static int cros_ec_ishtp_reset(struct ishtp_cl_device *cl_device)
708 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
709 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
711 schedule_work(&client_data->work_ishtp_reset);
717 * cros_ec_ishtp_suspend() - ISHTP client driver suspend callback
718 * @device: device instance
720 * Return: 0 for success, negative error code for failure.
722 static int __maybe_unused cros_ec_ishtp_suspend(struct device *device)
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);
728 return cros_ec_suspend(client_data->ec_dev);
732 * cros_ec_ishtp_resume() - ISHTP client driver resume callback
733 * @device: device instance
735 * Return: 0 for success, negative error code for failure.
737 static int __maybe_unused cros_ec_ishtp_resume(struct device *device)
739 struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(device);
740 struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
741 struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
743 return cros_ec_resume(client_data->ec_dev);
746 static SIMPLE_DEV_PM_OPS(cros_ec_ishtp_pm_ops, cros_ec_ishtp_suspend,
747 cros_ec_ishtp_resume);
749 static struct ishtp_cl_driver cros_ec_ishtp_driver = {
750 .name = "cros_ec_ishtp",
751 .guid = &cros_ish_guid,
752 .probe = cros_ec_ishtp_probe,
753 .remove = cros_ec_ishtp_remove,
754 .reset = cros_ec_ishtp_reset,
756 .pm = &cros_ec_ishtp_pm_ops,
760 static int __init cros_ec_ishtp_mod_init(void)
762 return ishtp_cl_driver_register(&cros_ec_ishtp_driver, THIS_MODULE);
765 static void __exit cros_ec_ishtp_mod_exit(void)
767 ishtp_cl_driver_unregister(&cros_ec_ishtp_driver);
770 module_init(cros_ec_ishtp_mod_init);
771 module_exit(cros_ec_ishtp_mod_exit);
773 MODULE_DESCRIPTION("ChromeOS EC ISHTP Client Driver");
774 MODULE_AUTHOR("Rushikesh S Kadam <rushikesh.s.kadam@intel.com>");
776 MODULE_LICENSE("GPL v2");
777 MODULE_ALIAS("ishtp:*");