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
27static struct most_component comp;
28
29struct 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
48struct 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
55static LIST_HEAD(video_devices);
56static DEFINE_SPINLOCK(list_lock);
57
58static inline bool data_ready(struct most_video_dev *mdev)
59{
60 return !list_empty(head: &mdev->pending_mbos);
61}
62
63static 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
68static int comp_vdev_open(struct file *filp)
69{
70 int ret;
71 struct video_device *vdev = video_devdata(file: filp);
72 struct most_video_dev *mdev = video_drvdata(file: 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(size: sizeof(*fh), GFP_KERNEL);
83 if (!fh)
84 return -ENOMEM;
85
86 if (!atomic_inc_and_test(v: &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->fh, vdev);
94 filp->private_data = fh;
95
96 v4l2_fh_add(fh: &fh->fh);
97
98 ret = most_start_channel(iface: mdev->iface, channel_idx: mdev->ch_idx, comp: &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
106err_rm:
107 v4l2_fh_del(fh: &fh->fh);
108 v4l2_fh_exit(fh: &fh->fh);
109
110err_dec:
111 atomic_dec(v: &mdev->access_ref);
112 kfree(objp: fh);
113 return ret;
114}
115
116static 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(lock: &mdev->list_lock);
132 mdev->mute = true;
133 list_for_each_entry_safe(mbo, tmp, &mdev->pending_mbos, list) {
134 list_del(entry: &mbo->list);
135 spin_unlock_irq(lock: &mdev->list_lock);
136 most_put_mbo(mbo);
137 spin_lock_irq(lock: &mdev->list_lock);
138 }
139 spin_unlock_irq(lock: &mdev->list_lock);
140 most_stop_channel(iface: mdev->iface, channel_idx: mdev->ch_idx, comp: &comp);
141 mdev->mute = false;
142
143 v4l2_fh_del(fh: &fh->fh);
144 v4l2_fh_exit(fh: &fh->fh);
145
146 atomic_dec(v: &mdev->access_ref);
147 kfree(objp: fh);
148 return 0;
149}
150
151static 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(to: buf, from: mbo->virt_address + fh->offs, n: 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(lock: &mdev->list_lock);
193 list_del(entry: &mbo->list);
194 spin_unlock_irq(lock: &mdev->list_lock);
195 most_put_mbo(mbo);
196 }
197 }
198 return ret;
199}
200
201static __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, wait_address: &mdev->wait_data, p: wait);
210 if (data_ready(mdev))
211 mask |= EPOLLIN | EPOLLRDNORM;
212
213 return mask;
214}
215
216static 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
228static 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(f: format);
238
239 return 0;
240}
241
242static 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(buf: cap->bus_info, size: sizeof(cap->bus_info),
251 fmt: "%s", mdev->iface->description);
252 return 0;
253}
254
255static 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
269static 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
276static 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, format: f);
283}
284
285static 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, format: f);
292}
293
294static int vidioc_g_std(struct file *file, void *priv, v4l2_std_id *norm)
295{
296 *norm = V4L2_STD_UNKNOWN;
297 return 0;
298}
299
300static 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
318static 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
326static 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
337static 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
346static 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
358static 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
368static struct most_video_dev *get_comp_dev(struct most_interface *iface, int channel_idx)
369{
370 struct most_video_dev *mdev;
371 unsigned long flags;
372
373 spin_lock_irqsave(&list_lock, flags);
374 list_for_each_entry(mdev, &video_devices, list) {
375 if (mdev->iface == iface && mdev->ch_idx == channel_idx) {
376 spin_unlock_irqrestore(lock: &list_lock, flags);
377 return mdev;
378 }
379 }
380 spin_unlock_irqrestore(lock: &list_lock, flags);
381 return NULL;
382}
383
384static int comp_rx_data(struct mbo *mbo)
385{
386 unsigned long flags;
387 struct most_video_dev *mdev =
388 get_comp_dev(iface: mbo->ifp, channel_idx: mbo->hdm_channel_id);
389
390 if (!mdev)
391 return -EIO;
392
393 spin_lock_irqsave(&mdev->list_lock, flags);
394 if (unlikely(mdev->mute)) {
395 spin_unlock_irqrestore(lock: &mdev->list_lock, flags);
396 return -EIO;
397 }
398
399 list_add_tail(new: &mbo->list, head: &mdev->pending_mbos);
400 spin_unlock_irqrestore(lock: &mdev->list_lock, flags);
401 wake_up_interruptible(&mdev->wait_data);
402 return 0;
403}
404
405static int comp_register_videodev(struct most_video_dev *mdev)
406{
407 int ret;
408
409 init_waitqueue_head(&mdev->wait_data);
410
411 /* allocate and fill v4l2 video struct */
412 mdev->vdev = video_device_alloc();
413 if (!mdev->vdev)
414 return -ENOMEM;
415
416 /* Fill the video capture device struct */
417 *mdev->vdev = comp_videodev_template;
418 mdev->vdev->v4l2_dev = &mdev->v4l2_dev;
419 mdev->vdev->lock = &mdev->lock;
420 snprintf(buf: mdev->vdev->name, size: sizeof(mdev->vdev->name), fmt: "MOST: %s",
421 mdev->v4l2_dev.name);
422
423 /* Register the v4l2 device */
424 video_set_drvdata(vdev: mdev->vdev, data: mdev);
425 ret = video_register_device(vdev: mdev->vdev, type: VFL_TYPE_VIDEO, nr: -1);
426 if (ret) {
427 v4l2_err(&mdev->v4l2_dev, "video_register_device failed (%d)\n",
428 ret);
429 video_device_release(vdev: mdev->vdev);
430 }
431
432 return ret;
433}
434
435static void comp_unregister_videodev(struct most_video_dev *mdev)
436{
437 video_unregister_device(vdev: mdev->vdev);
438}
439
440static void comp_v4l2_dev_release(struct v4l2_device *v4l2_dev)
441{
442 struct most_video_dev *mdev =
443 container_of(v4l2_dev, struct most_video_dev, v4l2_dev);
444
445 v4l2_device_unregister(v4l2_dev);
446 kfree(objp: mdev);
447}
448
449static int comp_probe_channel(struct most_interface *iface, int channel_idx,
450 struct most_channel_config *ccfg, char *name,
451 char *args)
452{
453 int ret;
454 struct most_video_dev *mdev = get_comp_dev(iface, channel_idx);
455
456 if (mdev) {
457 pr_err("channel already linked\n");
458 return -EEXIST;
459 }
460
461 if (ccfg->direction != MOST_CH_RX) {
462 pr_err("wrong direction, expect rx\n");
463 return -EINVAL;
464 }
465
466 if (ccfg->data_type != MOST_CH_SYNC &&
467 ccfg->data_type != MOST_CH_ISOC) {
468 pr_err("wrong channel type, expect sync or isoc\n");
469 return -EINVAL;
470 }
471
472 mdev = kzalloc(size: sizeof(*mdev), GFP_KERNEL);
473 if (!mdev)
474 return -ENOMEM;
475
476 mutex_init(&mdev->lock);
477 atomic_set(v: &mdev->access_ref, i: -1);
478 spin_lock_init(&mdev->list_lock);
479 INIT_LIST_HEAD(list: &mdev->pending_mbos);
480 mdev->iface = iface;
481 mdev->ch_idx = channel_idx;
482 mdev->v4l2_dev.release = comp_v4l2_dev_release;
483
484 /* Create the v4l2_device */
485 strscpy(mdev->v4l2_dev.name, name, sizeof(mdev->v4l2_dev.name));
486 ret = v4l2_device_register(NULL, v4l2_dev: &mdev->v4l2_dev);
487 if (ret) {
488 pr_err("v4l2_device_register() failed\n");
489 kfree(objp: mdev);
490 return ret;
491 }
492
493 ret = comp_register_videodev(mdev);
494 if (ret)
495 goto err_unreg;
496
497 spin_lock_irq(lock: &list_lock);
498 list_add(new: &mdev->list, head: &video_devices);
499 spin_unlock_irq(lock: &list_lock);
500 return 0;
501
502err_unreg:
503 v4l2_device_disconnect(v4l2_dev: &mdev->v4l2_dev);
504 v4l2_device_put(v4l2_dev: &mdev->v4l2_dev);
505 return ret;
506}
507
508static int comp_disconnect_channel(struct most_interface *iface,
509 int channel_idx)
510{
511 struct most_video_dev *mdev = get_comp_dev(iface, channel_idx);
512
513 if (!mdev) {
514 pr_err("no such channel is linked\n");
515 return -ENOENT;
516 }
517
518 spin_lock_irq(lock: &list_lock);
519 list_del(entry: &mdev->list);
520 spin_unlock_irq(lock: &list_lock);
521
522 comp_unregister_videodev(mdev);
523 v4l2_device_disconnect(v4l2_dev: &mdev->v4l2_dev);
524 v4l2_device_put(v4l2_dev: &mdev->v4l2_dev);
525 return 0;
526}
527
528static struct most_component comp = {
529 .mod = THIS_MODULE,
530 .name = "video",
531 .probe_channel = comp_probe_channel,
532 .disconnect_channel = comp_disconnect_channel,
533 .rx_completion = comp_rx_data,
534};
535
536static int __init comp_init(void)
537{
538 int err;
539
540 err = most_register_component(comp: &comp);
541 if (err)
542 return err;
543 err = most_register_configfs_subsys(comp: &comp);
544 if (err) {
545 most_deregister_component(comp: &comp);
546 return err;
547 }
548 return 0;
549}
550
551static void __exit comp_exit(void)
552{
553 struct most_video_dev *mdev, *tmp;
554
555 /*
556 * As the mostcore currently doesn't call disconnect_channel()
557 * for linked channels while we call most_deregister_component()
558 * we simulate this call here.
559 * This must be fixed in core.
560 */
561 spin_lock_irq(lock: &list_lock);
562 list_for_each_entry_safe(mdev, tmp, &video_devices, list) {
563 list_del(entry: &mdev->list);
564 spin_unlock_irq(lock: &list_lock);
565
566 comp_unregister_videodev(mdev);
567 v4l2_device_disconnect(v4l2_dev: &mdev->v4l2_dev);
568 v4l2_device_put(v4l2_dev: &mdev->v4l2_dev);
569 spin_lock_irq(lock: &list_lock);
570 }
571 spin_unlock_irq(lock: &list_lock);
572
573 most_deregister_configfs_subsys(comp: &comp);
574 most_deregister_component(comp: &comp);
575 BUG_ON(!list_empty(&video_devices));
576}
577
578module_init(comp_init);
579module_exit(comp_exit);
580
581MODULE_DESCRIPTION("V4L2 Component Module for Mostcore");
582MODULE_AUTHOR("Andrey Shvetsov <andrey.shvetsov@k2l.de>");
583MODULE_LICENSE("GPL");
584

source code of linux/drivers/staging/most/video/video.c