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(&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(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
106err_rm:
107	v4l2_fh_del(&fh->fh);
108	v4l2_fh_exit(&fh->fh);
109
110err_dec:
111	atomic_dec(&mdev->access_ref);
112	kfree(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(&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
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(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
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, &mdev->wait_data, 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(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(cap->bus_info, sizeof(cap->bus_info),
251		 "%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, 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, 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(&list_lock, flags);
377			return mdev;
378		}
379	}
380	spin_unlock_irqrestore(&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(mbo->ifp, 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(&mdev->list_lock, flags);
396		return -EIO;
397	}
398
399	list_add_tail(&mbo->list, &mdev->pending_mbos);
400	spin_unlock_irqrestore(&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(mdev->vdev->name, sizeof(mdev->vdev->name), "MOST: %s",
421		 mdev->v4l2_dev.name);
422
423	/* Register the v4l2 device */
424	video_set_drvdata(mdev->vdev, mdev);
425	ret = video_register_device(mdev->vdev, VFL_TYPE_VIDEO, -1);
426	if (ret) {
427		v4l2_err(&mdev->v4l2_dev, "video_register_device failed (%d)\n",
428			 ret);
429		video_device_release(mdev->vdev);
430	}
431
432	return ret;
433}
434
435static void comp_unregister_videodev(struct most_video_dev *mdev)
436{
437	video_unregister_device(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(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(sizeof(*mdev), GFP_KERNEL);
473	if (!mdev)
474		return -ENOMEM;
475
476	mutex_init(&mdev->lock);
477	atomic_set(&mdev->access_ref, -1);
478	spin_lock_init(&mdev->list_lock);
479	INIT_LIST_HEAD(&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, &mdev->v4l2_dev);
487	if (ret) {
488		pr_err("v4l2_device_register() failed\n");
489		kfree(mdev);
490		return ret;
491	}
492
493	ret = comp_register_videodev(mdev);
494	if (ret)
495		goto err_unreg;
496
497	spin_lock_irq(&list_lock);
498	list_add(&mdev->list, &video_devices);
499	spin_unlock_irq(&list_lock);
500	return 0;
501
502err_unreg:
503	v4l2_device_disconnect(&mdev->v4l2_dev);
504	v4l2_device_put(&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(&list_lock);
519	list_del(&mdev->list);
520	spin_unlock_irq(&list_lock);
521
522	comp_unregister_videodev(mdev);
523	v4l2_device_disconnect(&mdev->v4l2_dev);
524	v4l2_device_put(&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);
541	if (err)
542		return err;
543	err = most_register_configfs_subsys(&comp);
544	if (err) {
545		most_deregister_component(&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(&list_lock);
562	list_for_each_entry_safe(mdev, tmp, &video_devices, list) {
563		list_del(&mdev->list);
564		spin_unlock_irq(&list_lock);
565
566		comp_unregister_videodev(mdev);
567		v4l2_device_disconnect(&mdev->v4l2_dev);
568		v4l2_device_put(&mdev->v4l2_dev);
569		spin_lock_irq(&list_lock);
570	}
571	spin_unlock_irq(&list_lock);
572
573	most_deregister_configfs_subsys(&comp);
574	most_deregister_component(&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