1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2023 Intel Corporation. All rights reserved.
4 * Intel Visual Sensing Controller ACE Linux driver
8 * To set ownership of camera sensor, there is specific command, which
9 * is sent via MEI protocol. That's a two-step scheme where the firmware
10 * first acks receipt of the command and later responses the command was
11 * executed. The command sending function uses "completion" as the
12 * synchronization mechanism. The notification for command is received
13 * via a mei callback which wakes up the caller. There can be only one
14 * outstanding command at a time.
16 * The power line of camera sensor is directly connected to IVSC instead
17 * of host, when camera sensor ownership is switched to host, sensor is
18 * already powered up by firmware.
21 #include <linux/acpi.h>
22 #include <linux/completion.h>
23 #include <linux/delay.h>
24 #include <linux/kernel.h>
25 #include <linux/mei_cl_bus.h>
26 #include <linux/module.h>
27 #include <linux/mutex.h>
28 #include <linux/pm_runtime.h>
29 #include <linux/slab.h>
30 #include <linux/uuid.h>
31 #include <linux/workqueue.h>
33 /* indicating driver message */
35 /* indicating set command */
37 /* command timeout determined experimentally */
38 #define ACE_CMD_TIMEOUT (5 * HZ)
39 /* indicating the first command block */
40 #define ACE_CMD_INIT_BLOCK 1
41 /* indicating the last command block */
42 #define ACE_CMD_FINAL_BLOCK 1
43 /* size of camera status notification content */
44 #define ACE_CAMERA_STATUS_SIZE 5
46 /* UUID used to get firmware id */
47 #define ACE_GET_FW_ID_UUID UUID_LE(0x6167DCFB, 0x72F1, 0x4584, 0xBF, \
48 0xE3, 0x84, 0x17, 0x71, 0xAA, 0x79, 0x0B)
50 /* UUID used to get csi device */
51 #define MEI_CSI_UUID UUID_LE(0x92335FCF, 0x3203, 0x4472, \
52 0xAF, 0x93, 0x7b, 0x44, 0x53, 0xAC, 0x29, 0xDA)
54 /* identify firmware event type */
59 /* command response */
60 ACE_CMD_RESPONSE = 0x10,
63 /* identify camera sensor ownership */
64 enum ace_camera_owner {
69 /* identify the command id supported by firmware IPC */
71 /* used to switch camera sensor to host */
72 ACE_SWITCH_CAMERA_TO_HOST = 0x13,
74 /* used to switch camera sensor to IVSC */
75 ACE_SWITCH_CAMERA_TO_IVSC = 0x14,
77 /* used to get firmware id */
81 /* ACE command header structure */
96 /* ACE command parameter structure */
102 /* ACE command structure */
104 struct ace_cmd_hdr hdr;
105 union ace_cmd_param param;
108 /* ACE notification header */
109 union ace_notif_hdr {
141 u32 event_data_size : 16;
142 u32 request_target : 1;
143 u32 request_type : 5;
149 /* ACE notification content */
150 union ace_notif_cont {
153 u8 camera_status[ACE_CAMERA_STATUS_SIZE];
156 /* ACE notification structure */
158 union ace_notif_hdr hdr;
159 union ace_notif_cont cont;
163 struct mei_cl_device *cldev;
166 struct ace_notif cmd_ack;
167 /* command response */
168 struct ace_notif cmd_response;
169 /* used to wait for command ack and response */
170 struct completion cmd_completion;
171 /* lock used to prevent multiple call to send command */
174 /* used to construct command */
177 struct device *csi_dev;
179 /* runtime PM link from ace to csi */
180 struct device_link *csi_link;
182 struct work_struct work;
185 static inline void init_cmd_hdr(struct ace_cmd_hdr *hdr)
187 memset(hdr, 0, sizeof(struct ace_cmd_hdr));
189 hdr->type = ACE_CMD_SET;
190 hdr->msg_tgt = ACE_DRV_MSG;
191 hdr->init_block = ACE_CMD_INIT_BLOCK;
192 hdr->final_block = ACE_CMD_FINAL_BLOCK;
195 static int construct_command(struct mei_ace *ace, struct ace_cmd *cmd,
196 enum ace_cmd_id cmd_id)
198 union ace_cmd_param *param = &cmd->param;
199 struct ace_cmd_hdr *hdr = &cmd->hdr;
203 hdr->cmd_id = cmd_id;
206 param->uuid = ACE_GET_FW_ID_UUID;
207 hdr->param_size = sizeof(param->uuid);
209 case ACE_SWITCH_CAMERA_TO_IVSC:
211 hdr->firmware_id = ace->firmware_id;
212 hdr->param_size = sizeof(param->param);
214 case ACE_SWITCH_CAMERA_TO_HOST:
215 hdr->firmware_id = ace->firmware_id;
221 return hdr->param_size + sizeof(cmd->hdr);
224 /* send command to firmware */
225 static int mei_ace_send(struct mei_ace *ace, struct ace_cmd *cmd,
226 size_t len, bool only_ack)
228 union ace_notif_hdr *resp_hdr = &ace->cmd_response.hdr;
229 union ace_notif_hdr *ack_hdr = &ace->cmd_ack.hdr;
230 struct ace_cmd_hdr *cmd_hdr = &cmd->hdr;
233 mutex_lock(&ace->lock);
235 reinit_completion(&ace->cmd_completion);
237 ret = mei_cldev_send(ace->cldev, (u8 *)cmd, len);
241 ret = wait_for_completion_killable_timeout(&ace->cmd_completion,
250 if (ack_hdr->ack.cmd_id != cmd_hdr->cmd_id) {
255 /* command ack status */
256 ret = ack_hdr->ack.status;
265 ret = wait_for_completion_killable_timeout(&ace->cmd_completion,
276 if (resp_hdr->response.cmd_id != cmd_hdr->cmd_id)
280 mutex_unlock(&ace->lock);
285 static int ace_set_camera_owner(struct mei_ace *ace,
286 enum ace_camera_owner owner)
288 enum ace_cmd_id cmd_id;
293 if (owner == ACE_CAMERA_IVSC)
294 cmd_id = ACE_SWITCH_CAMERA_TO_IVSC;
296 cmd_id = ACE_SWITCH_CAMERA_TO_HOST;
298 cmd_size = construct_command(ace, &cmd, cmd_id);
300 ret = mei_ace_send(ace, &cmd, cmd_size, false);
307 /* the first command downloaded to firmware */
308 static inline int ace_get_firmware_id(struct mei_ace *ace)
314 cmd_size = construct_command(ace, &cmd, ACE_GET_FW_ID);
316 ret = mei_ace_send(ace, &cmd, cmd_size, true);
323 static void handle_command_response(struct mei_ace *ace,
324 struct ace_notif *resp, int len)
326 union ace_notif_hdr *hdr = &resp->hdr;
328 switch (hdr->response.cmd_id) {
329 case ACE_SWITCH_CAMERA_TO_IVSC:
330 case ACE_SWITCH_CAMERA_TO_HOST:
331 memcpy(&ace->cmd_response, resp, len);
332 complete(&ace->cmd_completion);
341 static void handle_command_ack(struct mei_ace *ace,
342 struct ace_notif *ack, int len)
344 union ace_notif_hdr *hdr = &ack->hdr;
346 switch (hdr->ack.cmd_id) {
348 ace->firmware_id = ack->cont.firmware_id;
350 case ACE_SWITCH_CAMERA_TO_IVSC:
351 case ACE_SWITCH_CAMERA_TO_HOST:
352 memcpy(&ace->cmd_ack, ack, len);
353 complete(&ace->cmd_completion);
360 /* callback for receive */
361 static void mei_ace_rx(struct mei_cl_device *cldev)
363 struct mei_ace *ace = mei_cldev_get_drvdata(cldev);
364 struct ace_notif event;
365 union ace_notif_hdr *hdr = &event.hdr;
368 ret = mei_cldev_recv(cldev, (u8 *)&event, sizeof(event));
370 dev_err(&cldev->dev, "recv error: %d\n", ret);
374 if (hdr->event.ack) {
375 handle_command_ack(ace, &event, ret);
379 switch (hdr->event.event_type) {
380 case ACE_CMD_RESPONSE:
381 handle_command_response(ace, &event, ret);
385 * firmware ready notification sent to driver
386 * after HECI client connected with firmware.
388 dev_dbg(&cldev->dev, "firmware ready\n");
395 static int mei_ace_setup_dev_link(struct mei_ace *ace)
397 struct device *dev = &ace->cldev->dev;
398 uuid_le uuid = MEI_CSI_UUID;
399 struct device *csi_dev;
403 snprintf(name, sizeof(name), "%s-%pUl", dev_name(dev->parent), &uuid);
405 csi_dev = device_find_child_by_name(dev->parent, name);
409 } else if (!dev_fwnode(csi_dev)) {
414 /* setup link between mei_ace and mei_csi */
415 ace->csi_link = device_link_add(csi_dev, dev, DL_FLAG_PM_RUNTIME |
416 DL_FLAG_RPM_ACTIVE | DL_FLAG_STATELESS);
417 if (!ace->csi_link) {
419 dev_err(dev, "failed to link to %s\n", dev_name(csi_dev));
423 ace->csi_dev = csi_dev;
434 /* switch camera to host before probe sensor device */
435 static void mei_ace_post_probe_work(struct work_struct *work)
437 struct acpi_device *adev;
442 ace = container_of(work, struct mei_ace, work);
443 dev = &ace->cldev->dev;
445 ret = ace_set_camera_owner(ace, ACE_CAMERA_HOST);
447 dev_err(dev, "switch camera to host failed: %d\n", ret);
451 adev = ACPI_COMPANION(dev->parent);
455 acpi_dev_clear_dependencies(adev);
458 static int mei_ace_probe(struct mei_cl_device *cldev,
459 const struct mei_cl_device_id *id)
461 struct device *dev = &cldev->dev;
465 ace = devm_kzalloc(dev, sizeof(struct mei_ace), GFP_KERNEL);
470 mutex_init(&ace->lock);
471 init_completion(&ace->cmd_completion);
472 INIT_WORK(&ace->work, mei_ace_post_probe_work);
474 mei_cldev_set_drvdata(cldev, ace);
476 ret = mei_cldev_enable(cldev);
478 dev_err(dev, "mei_cldev_enable failed: %d\n", ret);
482 ret = mei_cldev_register_rx_cb(cldev, mei_ace_rx);
484 dev_err(dev, "event cb registration failed: %d\n", ret);
488 ret = ace_get_firmware_id(ace);
490 dev_err(dev, "get firmware id failed: %d\n", ret);
494 pm_runtime_set_active(dev);
495 pm_runtime_enable(dev);
497 ret = mei_ace_setup_dev_link(ace);
501 schedule_work(&ace->work);
506 pm_runtime_disable(dev);
507 pm_runtime_set_suspended(dev);
510 mei_cldev_disable(cldev);
513 mutex_destroy(&ace->lock);
518 static void mei_ace_remove(struct mei_cl_device *cldev)
520 struct mei_ace *ace = mei_cldev_get_drvdata(cldev);
522 cancel_work_sync(&ace->work);
524 device_link_del(ace->csi_link);
525 put_device(ace->csi_dev);
527 pm_runtime_disable(&cldev->dev);
528 pm_runtime_set_suspended(&cldev->dev);
530 ace_set_camera_owner(ace, ACE_CAMERA_IVSC);
532 mutex_destroy(&ace->lock);
535 static int __maybe_unused mei_ace_runtime_suspend(struct device *dev)
537 struct mei_ace *ace = dev_get_drvdata(dev);
539 return ace_set_camera_owner(ace, ACE_CAMERA_IVSC);
542 static int __maybe_unused mei_ace_runtime_resume(struct device *dev)
544 struct mei_ace *ace = dev_get_drvdata(dev);
546 return ace_set_camera_owner(ace, ACE_CAMERA_HOST);
549 static const struct dev_pm_ops mei_ace_pm_ops = {
550 SET_RUNTIME_PM_OPS(mei_ace_runtime_suspend,
551 mei_ace_runtime_resume, NULL)
554 #define MEI_ACE_UUID UUID_LE(0x5DB76CF6, 0x0A68, 0x4ED6, \
555 0x9B, 0x78, 0x03, 0x61, 0x63, 0x5E, 0x24, 0x47)
557 static const struct mei_cl_device_id mei_ace_tbl[] = {
558 { .uuid = MEI_ACE_UUID, .version = MEI_CL_VERSION_ANY },
561 MODULE_DEVICE_TABLE(mei, mei_ace_tbl);
563 static struct mei_cl_driver mei_ace_driver = {
564 .id_table = mei_ace_tbl,
565 .name = KBUILD_MODNAME,
567 .probe = mei_ace_probe,
568 .remove = mei_ace_remove,
571 .pm = &mei_ace_pm_ops,
575 module_mei_cl_driver(mei_ace_driver);
577 MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>");
578 MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>");
579 MODULE_DESCRIPTION("Device driver for IVSC ACE");
580 MODULE_LICENSE("GPL");