1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * vimc-capture.c Virtual Media Controller Driver
  4 *
  5 * Copyright (C) 2015-2017 Helen Koike <helen.fornazier@gmail.com>
  6 */
  7
  8#include <linux/component.h>
  9#include <linux/module.h>
 10#include <linux/mod_devicetable.h>
 11#include <linux/platform_device.h>
 12#include <media/v4l2-ioctl.h>
 13#include <media/videobuf2-core.h>
 14#include <media/videobuf2-vmalloc.h>
 15
 16#include "vimc-common.h"
 17#include "vimc-streamer.h"
 18
 19#define VIMC_CAP_DRV_NAME "vimc-capture"
 20
 21struct vimc_cap_device {
 22	struct vimc_ent_device ved;
 23	struct video_device vdev;
 24	struct device *dev;
 25	struct v4l2_pix_format format;
 26	struct vb2_queue queue;
 27	struct list_head buf_list;
 28	/*
 29	 * NOTE: in a real driver, a spin lock must be used to access the
 30	 * queue because the frames are generated from a hardware interruption
 31	 * and the isr is not allowed to sleep.
 32	 * Even if it is not necessary a spinlock in the vimc driver, we
 33	 * use it here as a code reference
 34	 */
 35	spinlock_t qlock;
 36	struct mutex lock;
 37	u32 sequence;
 38	struct vimc_stream stream;
 39};
 40
 41static const struct v4l2_pix_format fmt_default = {
 42	.width = 640,
 43	.height = 480,
 44	.pixelformat = V4L2_PIX_FMT_RGB24,
 45	.field = V4L2_FIELD_NONE,
 46	.colorspace = V4L2_COLORSPACE_DEFAULT,
 47};
 48
 49struct vimc_cap_buffer {
 50	/*
 51	 * struct vb2_v4l2_buffer must be the first element
 52	 * the videobuf2 framework will allocate this struct based on
 53	 * buf_struct_size and use the first sizeof(struct vb2_buffer) bytes of
 54	 * memory as a vb2_buffer
 55	 */
 56	struct vb2_v4l2_buffer vb2;
 57	struct list_head list;
 58};
 59
 60static int vimc_cap_querycap(struct file *file, void *priv,
 61			     struct v4l2_capability *cap)
 62{
 63	strscpy(cap->driver, VIMC_PDEV_NAME, sizeof(cap->driver));
 64	strscpy(cap->card, KBUILD_MODNAME, sizeof(cap->card));
 65	snprintf(cap->bus_info, sizeof(cap->bus_info),
 66		 "platform:%s", VIMC_PDEV_NAME);
 67
 68	return 0;
 69}
 70
 71static void vimc_cap_get_format(struct vimc_ent_device *ved,
 72				struct v4l2_pix_format *fmt)
 73{
 74	struct vimc_cap_device *vcap = container_of(ved, struct vimc_cap_device,
 75						    ved);
 76
 77	*fmt = vcap->format;
 78}
 79
 80static int vimc_cap_g_fmt_vid_cap(struct file *file, void *priv,
 81				  struct v4l2_format *f)
 82{
 83	struct vimc_cap_device *vcap = video_drvdata(file);
 84
 85	f->fmt.pix = vcap->format;
 86
 87	return 0;
 88}
 89
 90static int vimc_cap_try_fmt_vid_cap(struct file *file, void *priv,
 91				    struct v4l2_format *f)
 92{
 93	struct v4l2_pix_format *format = &f->fmt.pix;
 94	const struct vimc_pix_map *vpix;
 95
 96	format->width = clamp_t(u32, format->width, VIMC_FRAME_MIN_WIDTH,
 97				VIMC_FRAME_MAX_WIDTH) & ~1;
 98	format->height = clamp_t(u32, format->height, VIMC_FRAME_MIN_HEIGHT,
 99				 VIMC_FRAME_MAX_HEIGHT) & ~1;
100
101	/* Don't accept a pixelformat that is not on the table */
102	vpix = vimc_pix_map_by_pixelformat(format->pixelformat);
103	if (!vpix) {
104		format->pixelformat = fmt_default.pixelformat;
105		vpix = vimc_pix_map_by_pixelformat(format->pixelformat);
106	}
107	/* TODO: Add support for custom bytesperline values */
108	format->bytesperline = format->width * vpix->bpp;
109	format->sizeimage = format->bytesperline * format->height;
110
111	if (format->field == V4L2_FIELD_ANY)
112		format->field = fmt_default.field;
113
114	vimc_colorimetry_clamp(format);
115
116	return 0;
117}
118
119static int vimc_cap_s_fmt_vid_cap(struct file *file, void *priv,
120				  struct v4l2_format *f)
121{
122	struct vimc_cap_device *vcap = video_drvdata(file);
123	int ret;
124
125	/* Do not change the format while stream is on */
126	if (vb2_is_busy(&vcap->queue))
127		return -EBUSY;
128
129	ret = vimc_cap_try_fmt_vid_cap(file, priv, f);
130	if (ret)
131		return ret;
132
133	dev_dbg(vcap->dev, "%s: format update: "
134		"old:%dx%d (0x%x, %d, %d, %d, %d) "
135		"new:%dx%d (0x%x, %d, %d, %d, %d)\n", vcap->vdev.name,
136		/* old */
137		vcap->format.width, vcap->format.height,
138		vcap->format.pixelformat, vcap->format.colorspace,
139		vcap->format.quantization, vcap->format.xfer_func,
140		vcap->format.ycbcr_enc,
141		/* new */
142		f->fmt.pix.width, f->fmt.pix.height,
143		f->fmt.pix.pixelformat,	f->fmt.pix.colorspace,
144		f->fmt.pix.quantization, f->fmt.pix.xfer_func,
145		f->fmt.pix.ycbcr_enc);
146
147	vcap->format = f->fmt.pix;
148
149	return 0;
150}
151
152static int vimc_cap_enum_fmt_vid_cap(struct file *file, void *priv,
153				     struct v4l2_fmtdesc *f)
154{
155	const struct vimc_pix_map *vpix = vimc_pix_map_by_index(f->index);
156
157	if (!vpix)
158		return -EINVAL;
159
160	f->pixelformat = vpix->pixelformat;
161
162	return 0;
163}
164
165static int vimc_cap_enum_framesizes(struct file *file, void *fh,
166				    struct v4l2_frmsizeenum *fsize)
167{
168	const struct vimc_pix_map *vpix;
169
170	if (fsize->index)
171		return -EINVAL;
172
173	/* Only accept code in the pix map table */
174	vpix = vimc_pix_map_by_code(fsize->pixel_format);
175	if (!vpix)
176		return -EINVAL;
177
178	fsize->type = V4L2_FRMSIZE_TYPE_CONTINUOUS;
179	fsize->stepwise.min_width = VIMC_FRAME_MIN_WIDTH;
180	fsize->stepwise.max_width = VIMC_FRAME_MAX_WIDTH;
181	fsize->stepwise.min_height = VIMC_FRAME_MIN_HEIGHT;
182	fsize->stepwise.max_height = VIMC_FRAME_MAX_HEIGHT;
183	fsize->stepwise.step_width = 1;
184	fsize->stepwise.step_height = 1;
185
186	return 0;
187}
188
189static const struct v4l2_file_operations vimc_cap_fops = {
190	.owner		= THIS_MODULE,
191	.open		= v4l2_fh_open,
192	.release	= vb2_fop_release,
193	.read           = vb2_fop_read,
194	.poll		= vb2_fop_poll,
195	.unlocked_ioctl = video_ioctl2,
196	.mmap           = vb2_fop_mmap,
197};
198
199static const struct v4l2_ioctl_ops vimc_cap_ioctl_ops = {
200	.vidioc_querycap = vimc_cap_querycap,
201
202	.vidioc_g_fmt_vid_cap = vimc_cap_g_fmt_vid_cap,
203	.vidioc_s_fmt_vid_cap = vimc_cap_s_fmt_vid_cap,
204	.vidioc_try_fmt_vid_cap = vimc_cap_try_fmt_vid_cap,
205	.vidioc_enum_fmt_vid_cap = vimc_cap_enum_fmt_vid_cap,
206	.vidioc_enum_framesizes = vimc_cap_enum_framesizes,
207
208	.vidioc_reqbufs = vb2_ioctl_reqbufs,
209	.vidioc_create_bufs = vb2_ioctl_create_bufs,
210	.vidioc_prepare_buf = vb2_ioctl_prepare_buf,
211	.vidioc_querybuf = vb2_ioctl_querybuf,
212	.vidioc_qbuf = vb2_ioctl_qbuf,
213	.vidioc_dqbuf = vb2_ioctl_dqbuf,
214	.vidioc_expbuf = vb2_ioctl_expbuf,
215	.vidioc_streamon = vb2_ioctl_streamon,
216	.vidioc_streamoff = vb2_ioctl_streamoff,
217};
218
219static void vimc_cap_return_all_buffers(struct vimc_cap_device *vcap,
220					enum vb2_buffer_state state)
221{
222	struct vimc_cap_buffer *vbuf, *node;
223
224	spin_lock(&vcap->qlock);
225
226	list_for_each_entry_safe(vbuf, node, &vcap->buf_list, list) {
227		list_del(&vbuf->list);
228		vb2_buffer_done(&vbuf->vb2.vb2_buf, state);
229	}
230
231	spin_unlock(&vcap->qlock);
232}
233
234static int vimc_cap_start_streaming(struct vb2_queue *vq, unsigned int count)
235{
236	struct vimc_cap_device *vcap = vb2_get_drv_priv(vq);
237	struct media_entity *entity = &vcap->vdev.entity;
238	int ret;
239
240	vcap->sequence = 0;
241
242	/* Start the media pipeline */
243	ret = media_pipeline_start(entity, &vcap->stream.pipe);
244	if (ret) {
245		vimc_cap_return_all_buffers(vcap, VB2_BUF_STATE_QUEUED);
246		return ret;
247	}
248
249	ret = vimc_streamer_s_stream(&vcap->stream, &vcap->ved, 1);
250	if (ret) {
251		media_pipeline_stop(entity);
252		vimc_cap_return_all_buffers(vcap, VB2_BUF_STATE_QUEUED);
253		return ret;
254	}
255
256	return 0;
257}
258
259/*
260 * Stop the stream engine. Any remaining buffers in the stream queue are
261 * dequeued and passed on to the vb2 framework marked as STATE_ERROR.
262 */
263static void vimc_cap_stop_streaming(struct vb2_queue *vq)
264{
265	struct vimc_cap_device *vcap = vb2_get_drv_priv(vq);
266
267	vimc_streamer_s_stream(&vcap->stream, &vcap->ved, 0);
268
269	/* Stop the media pipeline */
270	media_pipeline_stop(&vcap->vdev.entity);
271
272	/* Release all active buffers */
273	vimc_cap_return_all_buffers(vcap, VB2_BUF_STATE_ERROR);
274}
275
276static void vimc_cap_buf_queue(struct vb2_buffer *vb2_buf)
277{
278	struct vimc_cap_device *vcap = vb2_get_drv_priv(vb2_buf->vb2_queue);
279	struct vimc_cap_buffer *buf = container_of(vb2_buf,
280						   struct vimc_cap_buffer,
281						   vb2.vb2_buf);
282
283	spin_lock(&vcap->qlock);
284	list_add_tail(&buf->list, &vcap->buf_list);
285	spin_unlock(&vcap->qlock);
286}
287
288static int vimc_cap_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
289				unsigned int *nplanes, unsigned int sizes[],
290				struct device *alloc_devs[])
291{
292	struct vimc_cap_device *vcap = vb2_get_drv_priv(vq);
293
294	if (*nplanes)
295		return sizes[0] < vcap->format.sizeimage ? -EINVAL : 0;
296	/* We don't support multiplanes for now */
297	*nplanes = 1;
298	sizes[0] = vcap->format.sizeimage;
299
300	return 0;
301}
302
303static int vimc_cap_buffer_prepare(struct vb2_buffer *vb)
304{
305	struct vimc_cap_device *vcap = vb2_get_drv_priv(vb->vb2_queue);
306	unsigned long size = vcap->format.sizeimage;
307
308	if (vb2_plane_size(vb, 0) < size) {
309		dev_err(vcap->dev, "%s: buffer too small (%lu < %lu)\n",
310			vcap->vdev.name, vb2_plane_size(vb, 0), size);
311		return -EINVAL;
312	}
313	return 0;
314}
315
316static const struct vb2_ops vimc_cap_qops = {
317	.start_streaming	= vimc_cap_start_streaming,
318	.stop_streaming		= vimc_cap_stop_streaming,
319	.buf_queue		= vimc_cap_buf_queue,
320	.queue_setup		= vimc_cap_queue_setup,
321	.buf_prepare		= vimc_cap_buffer_prepare,
322	/*
323	 * Since q->lock is set we can use the standard
324	 * vb2_ops_wait_prepare/finish helper functions.
325	 */
326	.wait_prepare		= vb2_ops_wait_prepare,
327	.wait_finish		= vb2_ops_wait_finish,
328};
329
330static const struct media_entity_operations vimc_cap_mops = {
331	.link_validate		= vimc_link_validate,
332};
333
334static void vimc_cap_release(struct video_device *vdev)
335{
336	struct vimc_cap_device *vcap =
337		container_of(vdev, struct vimc_cap_device, vdev);
338
339	vimc_pads_cleanup(vcap->ved.pads);
340	kfree(vcap);
341}
342
343static void vimc_cap_comp_unbind(struct device *comp, struct device *master,
344				 void *master_data)
345{
346	struct vimc_ent_device *ved = dev_get_drvdata(comp);
347	struct vimc_cap_device *vcap = container_of(ved, struct vimc_cap_device,
348						    ved);
349
350	vb2_queue_release(&vcap->queue);
351	media_entity_cleanup(ved->ent);
352	video_unregister_device(&vcap->vdev);
353}
354
355static void *vimc_cap_process_frame(struct vimc_ent_device *ved,
356				    const void *frame)
357{
358	struct vimc_cap_device *vcap = container_of(ved, struct vimc_cap_device,
359						    ved);
360	struct vimc_cap_buffer *vimc_buf;
361	void *vbuf;
362
363	spin_lock(&vcap->qlock);
364
365	/* Get the first entry of the list */
366	vimc_buf = list_first_entry_or_null(&vcap->buf_list,
367					    typeof(*vimc_buf), list);
368	if (!vimc_buf) {
369		spin_unlock(&vcap->qlock);
370		return ERR_PTR(-EAGAIN);
371	}
372
373	/* Remove this entry from the list */
374	list_del(&vimc_buf->list);
375
376	spin_unlock(&vcap->qlock);
377
378	/* Fill the buffer */
379	vimc_buf->vb2.vb2_buf.timestamp = ktime_get_ns();
380	vimc_buf->vb2.sequence = vcap->sequence++;
381	vimc_buf->vb2.field = vcap->format.field;
382
383	vbuf = vb2_plane_vaddr(&vimc_buf->vb2.vb2_buf, 0);
384
385	memcpy(vbuf, frame, vcap->format.sizeimage);
386
387	/* Set it as ready */
388	vb2_set_plane_payload(&vimc_buf->vb2.vb2_buf, 0,
389			      vcap->format.sizeimage);
390	vb2_buffer_done(&vimc_buf->vb2.vb2_buf, VB2_BUF_STATE_DONE);
391	return NULL;
392}
393
394static int vimc_cap_comp_bind(struct device *comp, struct device *master,
395			      void *master_data)
396{
397	struct v4l2_device *v4l2_dev = master_data;
398	struct vimc_platform_data *pdata = comp->platform_data;
399	const struct vimc_pix_map *vpix;
400	struct vimc_cap_device *vcap;
401	struct video_device *vdev;
402	struct vb2_queue *q;
403	int ret;
404
405	/* Allocate the vimc_cap_device struct */
406	vcap = kzalloc(sizeof(*vcap), GFP_KERNEL);
407	if (!vcap)
408		return -ENOMEM;
409
410	/* Allocate the pads */
411	vcap->ved.pads =
412		vimc_pads_init(1, (const unsigned long[1]) {MEDIA_PAD_FL_SINK});
413	if (IS_ERR(vcap->ved.pads)) {
414		ret = PTR_ERR(vcap->ved.pads);
415		goto err_free_vcap;
416	}
417
418	/* Initialize the media entity */
419	vcap->vdev.entity.name = pdata->entity_name;
420	vcap->vdev.entity.function = MEDIA_ENT_F_IO_V4L;
421	ret = media_entity_pads_init(&vcap->vdev.entity,
422				     1, vcap->ved.pads);
423	if (ret)
424		goto err_clean_pads;
425
426	/* Initialize the lock */
427	mutex_init(&vcap->lock);
428
429	/* Initialize the vb2 queue */
430	q = &vcap->queue;
431	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
432	q->io_modes = VB2_MMAP | VB2_DMABUF | VB2_USERPTR;
433	q->drv_priv = vcap;
434	q->buf_struct_size = sizeof(struct vimc_cap_buffer);
435	q->ops = &vimc_cap_qops;
436	q->mem_ops = &vb2_vmalloc_memops;
437	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
438	q->min_buffers_needed = 2;
439	q->lock = &vcap->lock;
440
441	ret = vb2_queue_init(q);
442	if (ret) {
443		dev_err(comp, "%s: vb2 queue init failed (err=%d)\n",
444			pdata->entity_name, ret);
445		goto err_clean_m_ent;
446	}
447
448	/* Initialize buffer list and its lock */
449	INIT_LIST_HEAD(&vcap->buf_list);
450	spin_lock_init(&vcap->qlock);
451
452	/* Set default frame format */
453	vcap->format = fmt_default;
454	vpix = vimc_pix_map_by_pixelformat(vcap->format.pixelformat);
455	vcap->format.bytesperline = vcap->format.width * vpix->bpp;
456	vcap->format.sizeimage = vcap->format.bytesperline *
457				 vcap->format.height;
458
459	/* Fill the vimc_ent_device struct */
460	vcap->ved.ent = &vcap->vdev.entity;
461	vcap->ved.process_frame = vimc_cap_process_frame;
462	vcap->ved.vdev_get_format = vimc_cap_get_format;
463	dev_set_drvdata(comp, &vcap->ved);
464	vcap->dev = comp;
465
466	/* Initialize the video_device struct */
467	vdev = &vcap->vdev;
468	vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
469	vdev->entity.ops = &vimc_cap_mops;
470	vdev->release = vimc_cap_release;
471	vdev->fops = &vimc_cap_fops;
472	vdev->ioctl_ops = &vimc_cap_ioctl_ops;
473	vdev->lock = &vcap->lock;
474	vdev->queue = q;
475	vdev->v4l2_dev = v4l2_dev;
476	vdev->vfl_dir = VFL_DIR_RX;
477	strscpy(vdev->name, pdata->entity_name, sizeof(vdev->name));
478	video_set_drvdata(vdev, &vcap->ved);
479
480	/* Register the video_device with the v4l2 and the media framework */
481	ret = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
482	if (ret) {
483		dev_err(comp, "%s: video register failed (err=%d)\n",
484			vcap->vdev.name, ret);
485		goto err_release_queue;
486	}
487
488	return 0;
489
490err_release_queue:
491	vb2_queue_release(q);
492err_clean_m_ent:
493	media_entity_cleanup(&vcap->vdev.entity);
494err_clean_pads:
495	vimc_pads_cleanup(vcap->ved.pads);
496err_free_vcap:
497	kfree(vcap);
498
499	return ret;
500}
501
502static const struct component_ops vimc_cap_comp_ops = {
503	.bind = vimc_cap_comp_bind,
504	.unbind = vimc_cap_comp_unbind,
505};
506
507static int vimc_cap_probe(struct platform_device *pdev)
508{
509	return component_add(&pdev->dev, &vimc_cap_comp_ops);
510}
511
512static int vimc_cap_remove(struct platform_device *pdev)
513{
514	component_del(&pdev->dev, &vimc_cap_comp_ops);
515
516	return 0;
517}
518
519static const struct platform_device_id vimc_cap_driver_ids[] = {
520	{
521		.name           = VIMC_CAP_DRV_NAME,
522	},
523	{ }
524};
525
526static struct platform_driver vimc_cap_pdrv = {
527	.probe		= vimc_cap_probe,
528	.remove		= vimc_cap_remove,
529	.id_table	= vimc_cap_driver_ids,
530	.driver		= {
531		.name	= VIMC_CAP_DRV_NAME,
532	},
533};
534
535module_platform_driver(vimc_cap_pdrv);
536
537MODULE_DEVICE_TABLE(platform, vimc_cap_driver_ids);
538
539MODULE_DESCRIPTION("Virtual Media Controller Driver (VIMC) Capture");
540MODULE_AUTHOR("Helen Mae Koike Fornazier <helen.fornazier@gmail.com>");
541MODULE_LICENSE("GPL");