1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * video.c - V4L2 component for Mostcore
4 *
5 * Copyright (C) 2015, Microchip Technology Germany II GmbH & Co. KG
6 */
7
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 #include <linux/init.h>
13 #include <linux/device.h>
14 #include <linux/suspend.h>
15 #include <linux/videodev2.h>
16 #include <linux/mutex.h>
17 #include <media/v4l2-common.h>
18 #include <media/v4l2-ioctl.h>
19 #include <media/v4l2-event.h>
20 #include <media/v4l2-device.h>
21 #include <media/v4l2-ctrls.h>
22 #include <media/v4l2-fh.h>
23 #include <linux/most.h>
24
25 #define V4L2_CMP_MAX_INPUT 1
26
27 static struct most_component comp;
28
29 struct most_video_dev {
30 struct most_interface *iface;
31 int ch_idx;
32 struct list_head list;
33 bool mute;
34
35 struct list_head pending_mbos;
36 spinlock_t list_lock;
37
38 struct v4l2_device v4l2_dev;
39 atomic_t access_ref;
40 struct video_device *vdev;
41 unsigned int ctrl_input;
42
43 struct mutex lock;
44
45 wait_queue_head_t wait_data;
46 };
47
48 struct comp_fh {
49 /* must be the first field of this struct! */
50 struct v4l2_fh fh;
51 struct most_video_dev *mdev;
52 u32 offs;
53 };
54
55 static LIST_HEAD(video_devices);
56 static DEFINE_SPINLOCK(list_lock);
57
data_ready(struct most_video_dev * mdev)58 static inline bool data_ready(struct most_video_dev *mdev)
59 {
60 return !list_empty(&mdev->pending_mbos);
61 }
62
get_top_mbo(struct most_video_dev * mdev)63 static inline struct mbo *get_top_mbo(struct most_video_dev *mdev)
64 {
65 return list_first_entry(&mdev->pending_mbos, struct mbo, list);
66 }
67
comp_vdev_open(struct file * filp)68 static int comp_vdev_open(struct file *filp)
69 {
70 int ret;
71 struct video_device *vdev = video_devdata(filp);
72 struct most_video_dev *mdev = video_drvdata(filp);
73 struct comp_fh *fh;
74
75 switch (vdev->vfl_type) {
76 case VFL_TYPE_VIDEO:
77 break;
78 default:
79 return -EINVAL;
80 }
81
82 fh = kzalloc(sizeof(*fh), GFP_KERNEL);
83 if (!fh)
84 return -ENOMEM;
85
86 if (!atomic_inc_and_test(&mdev->access_ref)) {
87 v4l2_err(&mdev->v4l2_dev, "too many clients\n");
88 ret = -EBUSY;
89 goto err_dec;
90 }
91
92 fh->mdev = mdev;
93 v4l2_fh_init(&fh->fh, vdev);
94 filp->private_data = fh;
95
96 v4l2_fh_add(&fh->fh);
97
98 ret = most_start_channel(mdev->iface, mdev->ch_idx, &comp);
99 if (ret) {
100 v4l2_err(&mdev->v4l2_dev, "most_start_channel() failed\n");
101 goto err_rm;
102 }
103
104 return 0;
105
106 err_rm:
107 v4l2_fh_del(&fh->fh);
108 v4l2_fh_exit(&fh->fh);
109
110 err_dec:
111 atomic_dec(&mdev->access_ref);
112 kfree(fh);
113 return ret;
114 }
115
comp_vdev_close(struct file * filp)116 static int comp_vdev_close(struct file *filp)
117 {
118 struct comp_fh *fh = filp->private_data;
119 struct most_video_dev *mdev = fh->mdev;
120 struct mbo *mbo, *tmp;
121
122 /*
123 * We need to put MBOs back before we call most_stop_channel()
124 * to deallocate MBOs.
125 * From the other hand mostcore still calling rx_completion()
126 * to deliver MBOs until most_stop_channel() is called.
127 * Use mute to work around this issue.
128 * This must be implemented in core.
129 */
130
131 spin_lock_irq(&mdev->list_lock);
132 mdev->mute = true;
133 list_for_each_entry_safe(mbo, tmp, &mdev->pending_mbos, list) {
134 list_del(&mbo->list);
135 spin_unlock_irq(&mdev->list_lock);
136 most_put_mbo(mbo);
137 spin_lock_irq(&mdev->list_lock);
138 }
139 spin_unlock_irq(&mdev->list_lock);
140 most_stop_channel(mdev->iface, mdev->ch_idx, &comp);
141 mdev->mute = false;
142
143 v4l2_fh_del(&fh->fh);
144 v4l2_fh_exit(&fh->fh);
145
146 atomic_dec(&mdev->access_ref);
147 kfree(fh);
148 return 0;
149 }
150
comp_vdev_read(struct file * filp,char __user * buf,size_t count,loff_t * pos)151 static ssize_t comp_vdev_read(struct file *filp, char __user *buf,
152 size_t count, loff_t *pos)
153 {
154 struct comp_fh *fh = filp->private_data;
155 struct most_video_dev *mdev = fh->mdev;
156 int ret = 0;
157
158 if (*pos)
159 return -ESPIPE;
160
161 if (!mdev)
162 return -ENODEV;
163
164 /* wait for the first buffer */
165 if (!(filp->f_flags & O_NONBLOCK)) {
166 if (wait_event_interruptible(mdev->wait_data, data_ready(mdev)))
167 return -ERESTARTSYS;
168 }
169
170 if (!data_ready(mdev))
171 return -EAGAIN;
172
173 while (count > 0 && data_ready(mdev)) {
174 struct mbo *const mbo = get_top_mbo(mdev);
175 int const rem = mbo->processed_length - fh->offs;
176 int const cnt = rem < count ? rem : count;
177
178 if (copy_to_user(buf, mbo->virt_address + fh->offs, cnt)) {
179 v4l2_err(&mdev->v4l2_dev, "read: copy_to_user failed\n");
180 if (!ret)
181 ret = -EFAULT;
182 return ret;
183 }
184
185 fh->offs += cnt;
186 count -= cnt;
187 buf += cnt;
188 ret += cnt;
189
190 if (cnt >= rem) {
191 fh->offs = 0;
192 spin_lock_irq(&mdev->list_lock);
193 list_del(&mbo->list);
194 spin_unlock_irq(&mdev->list_lock);
195 most_put_mbo(mbo);
196 }
197 }
198 return ret;
199 }
200
comp_vdev_poll(struct file * filp,poll_table * wait)201 static __poll_t comp_vdev_poll(struct file *filp, poll_table *wait)
202 {
203 struct comp_fh *fh = filp->private_data;
204 struct most_video_dev *mdev = fh->mdev;
205 __poll_t mask = 0;
206
207 /* only wait if no data is available */
208 if (!data_ready(mdev))
209 poll_wait(filp, &mdev->wait_data, wait);
210 if (data_ready(mdev))
211 mask |= EPOLLIN | EPOLLRDNORM;
212
213 return mask;
214 }
215
comp_set_format_struct(struct v4l2_format * f)216 static void comp_set_format_struct(struct v4l2_format *f)
217 {
218 f->fmt.pix.width = 8;
219 f->fmt.pix.height = 8;
220 f->fmt.pix.pixelformat = V4L2_PIX_FMT_MPEG;
221 f->fmt.pix.bytesperline = 0;
222 f->fmt.pix.sizeimage = 188 * 2;
223 f->fmt.pix.colorspace = V4L2_COLORSPACE_REC709;
224 f->fmt.pix.field = V4L2_FIELD_NONE;
225 f->fmt.pix.priv = 0;
226 }
227
comp_set_format(struct most_video_dev * mdev,unsigned int cmd,struct v4l2_format * format)228 static int comp_set_format(struct most_video_dev *mdev, unsigned int cmd,
229 struct v4l2_format *format)
230 {
231 if (format->fmt.pix.pixelformat != V4L2_PIX_FMT_MPEG)
232 return -EINVAL;
233
234 if (cmd == VIDIOC_TRY_FMT)
235 return 0;
236
237 comp_set_format_struct(format);
238
239 return 0;
240 }
241
vidioc_querycap(struct file * file,void * priv,struct v4l2_capability * cap)242 static int vidioc_querycap(struct file *file, void *priv,
243 struct v4l2_capability *cap)
244 {
245 struct comp_fh *fh = priv;
246 struct most_video_dev *mdev = fh->mdev;
247
248 strscpy(cap->driver, "v4l2_component", sizeof(cap->driver));
249 strscpy(cap->card, "MOST", sizeof(cap->card));
250 snprintf(cap->bus_info, sizeof(cap->bus_info),
251 "%s", mdev->iface->description);
252 return 0;
253 }
254
vidioc_enum_fmt_vid_cap(struct file * file,void * priv,struct v4l2_fmtdesc * f)255 static int vidioc_enum_fmt_vid_cap(struct file *file, void *priv,
256 struct v4l2_fmtdesc *f)
257 {
258 if (f->index)
259 return -EINVAL;
260
261 strscpy(f->description, "MPEG", sizeof(f->description));
262 f->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
263 f->flags = V4L2_FMT_FLAG_COMPRESSED;
264 f->pixelformat = V4L2_PIX_FMT_MPEG;
265
266 return 0;
267 }
268
vidioc_g_fmt_vid_cap(struct file * file,void * priv,struct v4l2_format * f)269 static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
270 struct v4l2_format *f)
271 {
272 comp_set_format_struct(f);
273 return 0;
274 }
275
vidioc_try_fmt_vid_cap(struct file * file,void * priv,struct v4l2_format * f)276 static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
277 struct v4l2_format *f)
278 {
279 struct comp_fh *fh = priv;
280 struct most_video_dev *mdev = fh->mdev;
281
282 return comp_set_format(mdev, VIDIOC_TRY_FMT, f);
283 }
284
vidioc_s_fmt_vid_cap(struct file * file,void * priv,struct v4l2_format * f)285 static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
286 struct v4l2_format *f)
287 {
288 struct comp_fh *fh = priv;
289 struct most_video_dev *mdev = fh->mdev;
290
291 return comp_set_format(mdev, VIDIOC_S_FMT, f);
292 }
293
vidioc_g_std(struct file * file,void * priv,v4l2_std_id * norm)294 static int vidioc_g_std(struct file *file, void *priv, v4l2_std_id *norm)
295 {
296 *norm = V4L2_STD_UNKNOWN;
297 return 0;
298 }
299
vidioc_enum_input(struct file * file,void * priv,struct v4l2_input * input)300 static int vidioc_enum_input(struct file *file, void *priv,
301 struct v4l2_input *input)
302 {
303 struct comp_fh *fh = priv;
304 struct most_video_dev *mdev = fh->mdev;
305
306 if (input->index >= V4L2_CMP_MAX_INPUT)
307 return -EINVAL;
308
309 strscpy(input->name, "MOST Video", sizeof(input->name));
310 input->type |= V4L2_INPUT_TYPE_CAMERA;
311 input->audioset = 0;
312
313 input->std = mdev->vdev->tvnorms;
314
315 return 0;
316 }
317
vidioc_g_input(struct file * file,void * priv,unsigned int * i)318 static int vidioc_g_input(struct file *file, void *priv, unsigned int *i)
319 {
320 struct comp_fh *fh = priv;
321 struct most_video_dev *mdev = fh->mdev;
322 *i = mdev->ctrl_input;
323 return 0;
324 }
325
vidioc_s_input(struct file * file,void * priv,unsigned int index)326 static int vidioc_s_input(struct file *file, void *priv, unsigned int index)
327 {
328 struct comp_fh *fh = priv;
329 struct most_video_dev *mdev = fh->mdev;
330
331 if (index >= V4L2_CMP_MAX_INPUT)
332 return -EINVAL;
333 mdev->ctrl_input = index;
334 return 0;
335 }
336
337 static const struct v4l2_file_operations comp_fops = {
338 .owner = THIS_MODULE,
339 .open = comp_vdev_open,
340 .release = comp_vdev_close,
341 .read = comp_vdev_read,
342 .poll = comp_vdev_poll,
343 .unlocked_ioctl = video_ioctl2,
344 };
345
346 static const struct v4l2_ioctl_ops video_ioctl_ops = {
347 .vidioc_querycap = vidioc_querycap,
348 .vidioc_enum_fmt_vid_cap = vidioc_enum_fmt_vid_cap,
349 .vidioc_g_fmt_vid_cap = vidioc_g_fmt_vid_cap,
350 .vidioc_try_fmt_vid_cap = vidioc_try_fmt_vid_cap,
351 .vidioc_s_fmt_vid_cap = vidioc_s_fmt_vid_cap,
352 .vidioc_g_std = vidioc_g_std,
353 .vidioc_enum_input = vidioc_enum_input,
354 .vidioc_g_input = vidioc_g_input,
355 .vidioc_s_input = vidioc_s_input,
356 };
357
358 static const struct video_device comp_videodev_template = {
359 .fops = &comp_fops,
360 .release = video_device_release,
361 .ioctl_ops = &video_ioctl_ops,
362 .tvnorms = V4L2_STD_UNKNOWN,
363 .device_caps = V4L2_CAP_READWRITE | V4L2_CAP_VIDEO_CAPTURE,
364 };
365
366 /**************************************************************************/
367
get_comp_dev(struct most_interface * iface,int channel_idx)368 static struct most_video_dev *get_comp_dev(
369 struct most_interface *iface, int channel_idx)
370 {
371 struct most_video_dev *mdev;
372 unsigned long flags;
373
374 spin_lock_irqsave(&list_lock, flags);
375 list_for_each_entry(mdev, &video_devices, list) {
376 if (mdev->iface == iface && mdev->ch_idx == channel_idx) {
377 spin_unlock_irqrestore(&list_lock, flags);
378 return mdev;
379 }
380 }
381 spin_unlock_irqrestore(&list_lock, flags);
382 return NULL;
383 }
384
comp_rx_data(struct mbo * mbo)385 static int comp_rx_data(struct mbo *mbo)
386 {
387 unsigned long flags;
388 struct most_video_dev *mdev =
389 get_comp_dev(mbo->ifp, mbo->hdm_channel_id);
390
391 if (!mdev)
392 return -EIO;
393
394 spin_lock_irqsave(&mdev->list_lock, flags);
395 if (unlikely(mdev->mute)) {
396 spin_unlock_irqrestore(&mdev->list_lock, flags);
397 return -EIO;
398 }
399
400 list_add_tail(&mbo->list, &mdev->pending_mbos);
401 spin_unlock_irqrestore(&mdev->list_lock, flags);
402 wake_up_interruptible(&mdev->wait_data);
403 return 0;
404 }
405
comp_register_videodev(struct most_video_dev * mdev)406 static int comp_register_videodev(struct most_video_dev *mdev)
407 {
408 int ret;
409
410 init_waitqueue_head(&mdev->wait_data);
411
412 /* allocate and fill v4l2 video struct */
413 mdev->vdev = video_device_alloc();
414 if (!mdev->vdev)
415 return -ENOMEM;
416
417 /* Fill the video capture device struct */
418 *mdev->vdev = comp_videodev_template;
419 mdev->vdev->v4l2_dev = &mdev->v4l2_dev;
420 mdev->vdev->lock = &mdev->lock;
421 snprintf(mdev->vdev->name, sizeof(mdev->vdev->name), "MOST: %s",
422 mdev->v4l2_dev.name);
423
424 /* Register the v4l2 device */
425 video_set_drvdata(mdev->vdev, mdev);
426 ret = video_register_device(mdev->vdev, VFL_TYPE_VIDEO, -1);
427 if (ret) {
428 v4l2_err(&mdev->v4l2_dev, "video_register_device failed (%d)\n",
429 ret);
430 video_device_release(mdev->vdev);
431 }
432
433 return ret;
434 }
435
comp_unregister_videodev(struct most_video_dev * mdev)436 static void comp_unregister_videodev(struct most_video_dev *mdev)
437 {
438 video_unregister_device(mdev->vdev);
439 }
440
comp_v4l2_dev_release(struct v4l2_device * v4l2_dev)441 static void comp_v4l2_dev_release(struct v4l2_device *v4l2_dev)
442 {
443 struct most_video_dev *mdev =
444 container_of(v4l2_dev, struct most_video_dev, v4l2_dev);
445
446 v4l2_device_unregister(v4l2_dev);
447 kfree(mdev);
448 }
449
comp_probe_channel(struct most_interface * iface,int channel_idx,struct most_channel_config * ccfg,char * name,char * args)450 static int comp_probe_channel(struct most_interface *iface, int channel_idx,
451 struct most_channel_config *ccfg, char *name,
452 char *args)
453 {
454 int ret;
455 struct most_video_dev *mdev = get_comp_dev(iface, channel_idx);
456
457 if (mdev) {
458 pr_err("channel already linked\n");
459 return -EEXIST;
460 }
461
462 if (ccfg->direction != MOST_CH_RX) {
463 pr_err("wrong direction, expect rx\n");
464 return -EINVAL;
465 }
466
467 if (ccfg->data_type != MOST_CH_SYNC &&
468 ccfg->data_type != MOST_CH_ISOC) {
469 pr_err("wrong channel type, expect sync or isoc\n");
470 return -EINVAL;
471 }
472
473 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
474 if (!mdev)
475 return -ENOMEM;
476
477 mutex_init(&mdev->lock);
478 atomic_set(&mdev->access_ref, -1);
479 spin_lock_init(&mdev->list_lock);
480 INIT_LIST_HEAD(&mdev->pending_mbos);
481 mdev->iface = iface;
482 mdev->ch_idx = channel_idx;
483 mdev->v4l2_dev.release = comp_v4l2_dev_release;
484
485 /* Create the v4l2_device */
486 strscpy(mdev->v4l2_dev.name, name, sizeof(mdev->v4l2_dev.name));
487 ret = v4l2_device_register(NULL, &mdev->v4l2_dev);
488 if (ret) {
489 pr_err("v4l2_device_register() failed\n");
490 kfree(mdev);
491 return ret;
492 }
493
494 ret = comp_register_videodev(mdev);
495 if (ret)
496 goto err_unreg;
497
498 spin_lock_irq(&list_lock);
499 list_add(&mdev->list, &video_devices);
500 spin_unlock_irq(&list_lock);
501 return 0;
502
503 err_unreg:
504 v4l2_device_disconnect(&mdev->v4l2_dev);
505 v4l2_device_put(&mdev->v4l2_dev);
506 return ret;
507 }
508
comp_disconnect_channel(struct most_interface * iface,int channel_idx)509 static int comp_disconnect_channel(struct most_interface *iface,
510 int channel_idx)
511 {
512 struct most_video_dev *mdev = get_comp_dev(iface, channel_idx);
513
514 if (!mdev) {
515 pr_err("no such channel is linked\n");
516 return -ENOENT;
517 }
518
519 spin_lock_irq(&list_lock);
520 list_del(&mdev->list);
521 spin_unlock_irq(&list_lock);
522
523 comp_unregister_videodev(mdev);
524 v4l2_device_disconnect(&mdev->v4l2_dev);
525 v4l2_device_put(&mdev->v4l2_dev);
526 return 0;
527 }
528
529 static struct most_component comp = {
530 .mod = THIS_MODULE,
531 .name = "video",
532 .probe_channel = comp_probe_channel,
533 .disconnect_channel = comp_disconnect_channel,
534 .rx_completion = comp_rx_data,
535 };
536
comp_init(void)537 static int __init comp_init(void)
538 {
539 int err;
540
541 err = most_register_component(&comp);
542 if (err)
543 return err;
544 err = most_register_configfs_subsys(&comp);
545 if (err) {
546 most_deregister_component(&comp);
547 return err;
548 }
549 return 0;
550 }
551
comp_exit(void)552 static void __exit comp_exit(void)
553 {
554 struct most_video_dev *mdev, *tmp;
555
556 /*
557 * As the mostcore currently doesn't call disconnect_channel()
558 * for linked channels while we call most_deregister_component()
559 * we simulate this call here.
560 * This must be fixed in core.
561 */
562 spin_lock_irq(&list_lock);
563 list_for_each_entry_safe(mdev, tmp, &video_devices, list) {
564 list_del(&mdev->list);
565 spin_unlock_irq(&list_lock);
566
567 comp_unregister_videodev(mdev);
568 v4l2_device_disconnect(&mdev->v4l2_dev);
569 v4l2_device_put(&mdev->v4l2_dev);
570 spin_lock_irq(&list_lock);
571 }
572 spin_unlock_irq(&list_lock);
573
574 most_deregister_configfs_subsys(&comp);
575 most_deregister_component(&comp);
576 BUG_ON(!list_empty(&video_devices));
577 }
578
579 module_init(comp_init);
580 module_exit(comp_exit);
581
582 MODULE_DESCRIPTION("V4L2 Component Module for Mostcore");
583 MODULE_AUTHOR("Andrey Shvetsov <andrey.shvetsov@k2l.de>");
584 MODULE_LICENSE("GPL");
585