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Based on kernel version 3.16. Page generated on 2014-08-06 21:41 EST.

1	/*
2	 * This is a V4L2 PCI Skeleton Driver. It gives an initial skeleton source
3	 * for use with other PCI drivers.
4	 *
5	 * This skeleton PCI driver assumes that the card has an S-Video connector as
6	 * input 0 and an HDMI connector as input 1.
7	 *
8	 * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
9	 *
10	 * This program is free software; you may redistribute it and/or modify
11	 * it under the terms of the GNU General Public License as published by
12	 * the Free Software Foundation; version 2 of the License.
13	 *
14	 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
15	 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
16	 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
17	 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
18	 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
19	 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
20	 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21	 * SOFTWARE.
22	 */
23	
24	#include <linux/types.h>
25	#include <linux/kernel.h>
26	#include <linux/module.h>
27	#include <linux/init.h>
28	#include <linux/kmod.h>
29	#include <linux/mutex.h>
30	#include <linux/pci.h>
31	#include <linux/interrupt.h>
32	#include <linux/videodev2.h>
33	#include <linux/v4l2-dv-timings.h>
34	#include <media/v4l2-device.h>
35	#include <media/v4l2-dev.h>
36	#include <media/v4l2-ioctl.h>
37	#include <media/v4l2-dv-timings.h>
38	#include <media/v4l2-ctrls.h>
39	#include <media/v4l2-event.h>
40	#include <media/videobuf2-dma-contig.h>
41	
42	MODULE_DESCRIPTION("V4L2 PCI Skeleton Driver");
43	MODULE_AUTHOR("Hans Verkuil");
44	MODULE_LICENSE("GPL v2");
45	MODULE_DEVICE_TABLE(pci, skeleton_pci_tbl);
46	
47	/**
48	 * struct skeleton - All internal data for one instance of device
49	 * @pdev: PCI device
50	 * @v4l2_dev: top-level v4l2 device struct
51	 * @vdev: video node structure
52	 * @ctrl_handler: control handler structure
53	 * @lock: ioctl serialization mutex
54	 * @std: current SDTV standard
55	 * @timings: current HDTV timings
56	 * @format: current pix format
57	 * @input: current video input (0 = SDTV, 1 = HDTV)
58	 * @queue: vb2 video capture queue
59	 * @alloc_ctx: vb2 contiguous DMA context
60	 * @qlock: spinlock controlling access to buf_list and sequence
61	 * @buf_list: list of buffers queued for DMA
62	 * @sequence: frame sequence counter
63	 */
64	struct skeleton {
65		struct pci_dev *pdev;
66		struct v4l2_device v4l2_dev;
67		struct video_device vdev;
68		struct v4l2_ctrl_handler ctrl_handler;
69		struct mutex lock;
70		v4l2_std_id std;
71		struct v4l2_dv_timings timings;
72		struct v4l2_pix_format format;
73		unsigned input;
74	
75		struct vb2_queue queue;
76		struct vb2_alloc_ctx *alloc_ctx;
77	
78		spinlock_t qlock;
79		struct list_head buf_list;
80		unsigned field;
81		unsigned sequence;
82	};
83	
84	struct skel_buffer {
85		struct vb2_buffer vb;
86		struct list_head list;
87	};
88	
89	static inline struct skel_buffer *to_skel_buffer(struct vb2_buffer *vb2)
90	{
91		return container_of(vb2, struct skel_buffer, vb);
92	}
93	
94	static const struct pci_device_id skeleton_pci_tbl[] = {
95		/* { PCI_DEVICE(PCI_VENDOR_ID_, PCI_DEVICE_ID_) }, */
96		{ 0, }
97	};
98	
99	/*
100	 * HDTV: this structure has the capabilities of the HDTV receiver.
101	 * It is used to constrain the huge list of possible formats based
102	 * upon the hardware capabilities.
103	 */
104	static const struct v4l2_dv_timings_cap skel_timings_cap = {
105		.type = V4L2_DV_BT_656_1120,
106		/* keep this initialization for compatibility with GCC < 4.4.6 */
107		.reserved = { 0 },
108		V4L2_INIT_BT_TIMINGS(
109			720, 1920,		/* min/max width */
110			480, 1080,		/* min/max height */
111			27000000, 74250000,	/* min/max pixelclock*/
112			V4L2_DV_BT_STD_CEA861,	/* Supported standards */
113			/* capabilities */
114			V4L2_DV_BT_CAP_INTERLACED | V4L2_DV_BT_CAP_PROGRESSIVE
115		)
116	};
117	
118	/*
119	 * Supported SDTV standards. This does the same job as skel_timings_cap, but
120	 * for standard TV formats.
121	 */
122	#define SKEL_TVNORMS V4L2_STD_ALL
123	
124	/*
125	 * Interrupt handler: typically interrupts happen after a new frame has been
126	 * captured. It is the job of the handler to remove the new frame from the
127	 * internal list and give it back to the vb2 framework, updating the sequence
128	 * counter, field and timestamp at the same time.
129	 */
130	static irqreturn_t skeleton_irq(int irq, void *dev_id)
131	{
132	#ifdef TODO
133		struct skeleton *skel = dev_id;
134	
135		/* handle interrupt */
136	
137		/* Once a new frame has been captured, mark it as done like this: */
138		if (captured_new_frame) {
139			...
140			spin_lock(&skel->qlock);
141			list_del(&new_buf->list);
142			spin_unlock(&skel->qlock);
143			v4l2_get_timestamp(&new_buf->vb.v4l2_buf.timestamp);
144			new_buf->vb.v4l2_buf.sequence = skel->sequence++;
145			new_buf->vb.v4l2_buf.field = skel->field;
146			if (skel->format.field == V4L2_FIELD_ALTERNATE) {
147				if (skel->field == V4L2_FIELD_BOTTOM)
148					skel->field = V4L2_FIELD_TOP;
149				else if (skel->field == V4L2_FIELD_TOP)
150					skel->field = V4L2_FIELD_BOTTOM;
151			}
152			vb2_buffer_done(&new_buf->vb, VB2_BUF_STATE_DONE);
153		}
154	#endif
155		return IRQ_HANDLED;
156	}
157	
158	/*
159	 * Setup the constraints of the queue: besides setting the number of planes
160	 * per buffer and the size and allocation context of each plane, it also
161	 * checks if sufficient buffers have been allocated. Usually 3 is a good
162	 * minimum number: many DMA engines need a minimum of 2 buffers in the
163	 * queue and you need to have another available for userspace processing.
164	 */
165	static int queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt,
166			       unsigned int *nbuffers, unsigned int *nplanes,
167			       unsigned int sizes[], void *alloc_ctxs[])
168	{
169		struct skeleton *skel = vb2_get_drv_priv(vq);
170	
171		skel->field = skel->format.field;
172		if (skel->field == V4L2_FIELD_ALTERNATE) {
173			/*
174			 * You cannot use read() with FIELD_ALTERNATE since the field
175			 * information (TOP/BOTTOM) cannot be passed back to the user.
176			 */
177			if (vb2_fileio_is_active(vq))
178				return -EINVAL;
179			skel->field = V4L2_FIELD_TOP;
180		}
181	
182		if (vq->num_buffers + *nbuffers < 3)
183			*nbuffers = 3 - vq->num_buffers;
184	
185		if (fmt && fmt->fmt.pix.sizeimage < skel->format.sizeimage)
186			return -EINVAL;
187		*nplanes = 1;
188		sizes[0] = fmt ? fmt->fmt.pix.sizeimage : skel->format.sizeimage;
189		alloc_ctxs[0] = skel->alloc_ctx;
190		return 0;
191	}
192	
193	/*
194	 * Prepare the buffer for queueing to the DMA engine: check and set the
195	 * payload size.
196	 */
197	static int buffer_prepare(struct vb2_buffer *vb)
198	{
199		struct skeleton *skel = vb2_get_drv_priv(vb->vb2_queue);
200		unsigned long size = skel->format.sizeimage;
201	
202		if (vb2_plane_size(vb, 0) < size) {
203			dev_err(&skel->pdev->dev, "buffer too small (%lu < %lu)\n",
204				 vb2_plane_size(vb, 0), size);
205			return -EINVAL;
206		}
207	
208		vb2_set_plane_payload(vb, 0, size);
209		return 0;
210	}
211	
212	/*
213	 * Queue this buffer to the DMA engine.
214	 */
215	static void buffer_queue(struct vb2_buffer *vb)
216	{
217		struct skeleton *skel = vb2_get_drv_priv(vb->vb2_queue);
218		struct skel_buffer *buf = to_skel_buffer(vb);
219		unsigned long flags;
220	
221		spin_lock_irqsave(&skel->qlock, flags);
222		list_add_tail(&buf->list, &skel->buf_list);
223	
224		/* TODO: Update any DMA pointers if necessary */
225	
226		spin_unlock_irqrestore(&skel->qlock, flags);
227	}
228	
229	static void return_all_buffers(struct skeleton *skel,
230				       enum vb2_buffer_state state)
231	{
232		struct skel_buffer *buf, *node;
233		unsigned long flags;
234	
235		spin_lock_irqsave(&skel->qlock, flags);
236		list_for_each_entry_safe(buf, node, &skel->buf_list, list) {
237			vb2_buffer_done(&buf->vb, state);
238			list_del(&buf->list);
239		}
240		spin_unlock_irqrestore(&skel->qlock, flags);
241	}
242	
243	/*
244	 * Start streaming. First check if the minimum number of buffers have been
245	 * queued. If not, then return -ENOBUFS and the vb2 framework will call
246	 * this function again the next time a buffer has been queued until enough
247	 * buffers are available to actually start the DMA engine.
248	 */
249	static int start_streaming(struct vb2_queue *vq, unsigned int count)
250	{
251		struct skeleton *skel = vb2_get_drv_priv(vq);
252		int ret = 0;
253	
254		skel->sequence = 0;
255	
256		/* TODO: start DMA */
257	
258		if (ret) {
259			/*
260			 * In case of an error, return all active buffers to the
261			 * QUEUED state
262			 */
263			return_all_buffers(skel, VB2_BUF_STATE_QUEUED);
264		}
265		return ret;
266	}
267	
268	/*
269	 * Stop the DMA engine. Any remaining buffers in the DMA queue are dequeued
270	 * and passed on to the vb2 framework marked as STATE_ERROR.
271	 */
272	static void stop_streaming(struct vb2_queue *vq)
273	{
274		struct skeleton *skel = vb2_get_drv_priv(vq);
275	
276		/* TODO: stop DMA */
277	
278		/* Release all active buffers */
279		return_all_buffers(skel, VB2_BUF_STATE_ERROR);
280	}
281	
282	/*
283	 * The vb2 queue ops. Note that since q->lock is set we can use the standard
284	 * vb2_ops_wait_prepare/finish helper functions. If q->lock would be NULL,
285	 * then this driver would have to provide these ops.
286	 */
287	static struct vb2_ops skel_qops = {
288		.queue_setup		= queue_setup,
289		.buf_prepare		= buffer_prepare,
290		.buf_queue		= buffer_queue,
291		.start_streaming	= start_streaming,
292		.stop_streaming		= stop_streaming,
293		.wait_prepare		= vb2_ops_wait_prepare,
294		.wait_finish		= vb2_ops_wait_finish,
295	};
296	
297	/*
298	 * Required ioctl querycap. Note that the version field is prefilled with
299	 * the version of the kernel.
300	 */
301	static int skeleton_querycap(struct file *file, void *priv,
302				     struct v4l2_capability *cap)
303	{
304		struct skeleton *skel = video_drvdata(file);
305	
306		strlcpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver));
307		strlcpy(cap->card, "V4L2 PCI Skeleton", sizeof(cap->card));
308		snprintf(cap->bus_info, sizeof(cap->bus_info), "PCI:%s",
309			 pci_name(skel->pdev));
310		cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE |
311				   V4L2_CAP_STREAMING;
312		cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
313		return 0;
314	}
315	
316	/*
317	 * Helper function to check and correct struct v4l2_pix_format. It's used
318	 * not only in VIDIOC_TRY/S_FMT, but also elsewhere if changes to the SDTV
319	 * standard, HDTV timings or the video input would require updating the
320	 * current format.
321	 */
322	static void skeleton_fill_pix_format(struct skeleton *skel,
323					     struct v4l2_pix_format *pix)
324	{
325		pix->pixelformat = V4L2_PIX_FMT_YUYV;
326		if (skel->input == 0) {
327			/* S-Video input */
328			pix->width = 720;
329			pix->height = (skel->std & V4L2_STD_525_60) ? 480 : 576;
330			pix->field = V4L2_FIELD_INTERLACED;
331			pix->colorspace = V4L2_COLORSPACE_SMPTE170M;
332		} else {
333			/* HDMI input */
334			pix->width = skel->timings.bt.width;
335			pix->height = skel->timings.bt.height;
336			if (skel->timings.bt.interlaced) {
337				pix->field = V4L2_FIELD_ALTERNATE;
338				pix->height /= 2;
339			} else {
340				pix->field = V4L2_FIELD_NONE;
341			}
342			pix->colorspace = V4L2_COLORSPACE_REC709;
343		}
344	
345		/*
346		 * The YUYV format is four bytes for every two pixels, so bytesperline
347		 * is width * 2.
348		 */
349		pix->bytesperline = pix->width * 2;
350		pix->sizeimage = pix->bytesperline * pix->height;
351		pix->priv = 0;
352	}
353	
354	static int skeleton_try_fmt_vid_cap(struct file *file, void *priv,
355					    struct v4l2_format *f)
356	{
357		struct skeleton *skel = video_drvdata(file);
358		struct v4l2_pix_format *pix = &f->fmt.pix;
359	
360		/*
361		 * Due to historical reasons providing try_fmt with an unsupported
362		 * pixelformat will return -EINVAL for video receivers. Webcam drivers,
363		 * however, will silently correct the pixelformat. Some video capture
364		 * applications rely on this behavior...
365		 */
366		if (pix->pixelformat != V4L2_PIX_FMT_YUYV)
367			return -EINVAL;
368		skeleton_fill_pix_format(skel, pix);
369		return 0;
370	}
371	
372	static int skeleton_s_fmt_vid_cap(struct file *file, void *priv,
373					  struct v4l2_format *f)
374	{
375		struct skeleton *skel = video_drvdata(file);
376		int ret;
377	
378		ret = skeleton_try_fmt_vid_cap(file, priv, f);
379		if (ret)
380			return ret;
381	
382		/*
383		 * It is not allowed to change the format while buffers for use with
384		 * streaming have already been allocated.
385		 */
386		if (vb2_is_busy(&skel->queue))
387			return -EBUSY;
388	
389		/* TODO: change format */
390		skel->format = f->fmt.pix;
391		return 0;
392	}
393	
394	static int skeleton_g_fmt_vid_cap(struct file *file, void *priv,
395					  struct v4l2_format *f)
396	{
397		struct skeleton *skel = video_drvdata(file);
398	
399		f->fmt.pix = skel->format;
400		return 0;
401	}
402	
403	static int skeleton_enum_fmt_vid_cap(struct file *file, void *priv,
404					     struct v4l2_fmtdesc *f)
405	{
406		if (f->index != 0)
407			return -EINVAL;
408	
409		strlcpy(f->description, "4:2:2, packed, YUYV", sizeof(f->description));
410		f->pixelformat = V4L2_PIX_FMT_YUYV;
411		f->flags = 0;
412		return 0;
413	}
414	
415	static int skeleton_s_std(struct file *file, void *priv, v4l2_std_id std)
416	{
417		struct skeleton *skel = video_drvdata(file);
418	
419		/* S_STD is not supported on the HDMI input */
420		if (skel->input)
421			return -ENODATA;
422	
423		/*
424		 * No change, so just return. Some applications call S_STD again after
425		 * the buffers for streaming have been set up, so we have to allow for
426		 * this behavior.
427		 */
428		if (std == skel->std)
429			return 0;
430	
431		/*
432		 * Changing the standard implies a format change, which is not allowed
433		 * while buffers for use with streaming have already been allocated.
434		 */
435		if (vb2_is_busy(&skel->queue))
436			return -EBUSY;
437	
438		/* TODO: handle changing std */
439	
440		skel->std = std;
441	
442		/* Update the internal format */
443		skeleton_fill_pix_format(skel, &skel->format);
444		return 0;
445	}
446	
447	static int skeleton_g_std(struct file *file, void *priv, v4l2_std_id *std)
448	{
449		struct skeleton *skel = video_drvdata(file);
450	
451		/* G_STD is not supported on the HDMI input */
452		if (skel->input)
453			return -ENODATA;
454	
455		*std = skel->std;
456		return 0;
457	}
458	
459	/*
460	 * Query the current standard as seen by the hardware. This function shall
461	 * never actually change the standard, it just detects and reports.
462	 * The framework will initially set *std to tvnorms (i.e. the set of
463	 * supported standards by this input), and this function should just AND
464	 * this value. If there is no signal, then *std should be set to 0.
465	 */
466	static int skeleton_querystd(struct file *file, void *priv, v4l2_std_id *std)
467	{
468		struct skeleton *skel = video_drvdata(file);
469	
470		/* QUERY_STD is not supported on the HDMI input */
471		if (skel->input)
472			return -ENODATA;
473	
474	#ifdef TODO
475		/*
476		 * Query currently seen standard. Initial value of *std is
477		 * V4L2_STD_ALL. This function should look something like this:
478		 */
479		get_signal_info();
480		if (no_signal) {
481			*std = 0;
482			return 0;
483		}
484		/* Use signal information to reduce the number of possible standards */
485		if (signal_has_525_lines)
486			*std &= V4L2_STD_525_60;
487		else
488			*std &= V4L2_STD_625_50;
489	#endif
490		return 0;
491	}
492	
493	static int skeleton_s_dv_timings(struct file *file, void *_fh,
494					 struct v4l2_dv_timings *timings)
495	{
496		struct skeleton *skel = video_drvdata(file);
497	
498		/* S_DV_TIMINGS is not supported on the S-Video input */
499		if (skel->input == 0)
500			return -ENODATA;
501	
502		/* Quick sanity check */
503		if (!v4l2_valid_dv_timings(timings, &skel_timings_cap, NULL, NULL))
504			return -EINVAL;
505	
506		/* Check if the timings are part of the CEA-861 timings. */
507		if (!v4l2_find_dv_timings_cap(timings, &skel_timings_cap,
508					      0, NULL, NULL))
509			return -EINVAL;
510	
511		/* Return 0 if the new timings are the same as the current timings. */
512		if (v4l2_match_dv_timings(timings, &skel->timings, 0))
513			return 0;
514	
515		/*
516		 * Changing the timings implies a format change, which is not allowed
517		 * while buffers for use with streaming have already been allocated.
518		 */
519		if (vb2_is_busy(&skel->queue))
520			return -EBUSY;
521	
522		/* TODO: Configure new timings */
523	
524		/* Save timings */
525		skel->timings = *timings;
526	
527		/* Update the internal format */
528		skeleton_fill_pix_format(skel, &skel->format);
529		return 0;
530	}
531	
532	static int skeleton_g_dv_timings(struct file *file, void *_fh,
533					 struct v4l2_dv_timings *timings)
534	{
535		struct skeleton *skel = video_drvdata(file);
536	
537		/* G_DV_TIMINGS is not supported on the S-Video input */
538		if (skel->input == 0)
539			return -ENODATA;
540	
541		*timings = skel->timings;
542		return 0;
543	}
544	
545	static int skeleton_enum_dv_timings(struct file *file, void *_fh,
546					    struct v4l2_enum_dv_timings *timings)
547	{
548		struct skeleton *skel = video_drvdata(file);
549	
550		/* ENUM_DV_TIMINGS is not supported on the S-Video input */
551		if (skel->input == 0)
552			return -ENODATA;
553	
554		return v4l2_enum_dv_timings_cap(timings, &skel_timings_cap,
555						NULL, NULL);
556	}
557	
558	/*
559	 * Query the current timings as seen by the hardware. This function shall
560	 * never actually change the timings, it just detects and reports.
561	 * If no signal is detected, then return -ENOLINK. If the hardware cannot
562	 * lock to the signal, then return -ENOLCK. If the signal is out of range
563	 * of the capabilities of the system (e.g., it is possible that the receiver
564	 * can lock but that the DMA engine it is connected to cannot handle
565	 * pixelclocks above a certain frequency), then -ERANGE is returned.
566	 */
567	static int skeleton_query_dv_timings(struct file *file, void *_fh,
568					     struct v4l2_dv_timings *timings)
569	{
570		struct skeleton *skel = video_drvdata(file);
571	
572		/* QUERY_DV_TIMINGS is not supported on the S-Video input */
573		if (skel->input == 0)
574			return -ENODATA;
575	
576	#ifdef TODO
577		/*
578		 * Query currently seen timings. This function should look
579		 * something like this:
580		 */
581		detect_timings();
582		if (no_signal)
583			return -ENOLINK;
584		if (cannot_lock_to_signal)
585			return -ENOLCK;
586		if (signal_out_of_range_of_capabilities)
587			return -ERANGE;
588	
589		/* Useful for debugging */
590		v4l2_print_dv_timings(skel->v4l2_dev.name, "query_dv_timings:",
591				timings, true);
592	#endif
593		return 0;
594	}
595	
596	static int skeleton_dv_timings_cap(struct file *file, void *fh,
597					   struct v4l2_dv_timings_cap *cap)
598	{
599		struct skeleton *skel = video_drvdata(file);
600	
601		/* DV_TIMINGS_CAP is not supported on the S-Video input */
602		if (skel->input == 0)
603			return -ENODATA;
604		*cap = skel_timings_cap;
605		return 0;
606	}
607	
608	static int skeleton_enum_input(struct file *file, void *priv,
609				       struct v4l2_input *i)
610	{
611		if (i->index > 1)
612			return -EINVAL;
613	
614		i->type = V4L2_INPUT_TYPE_CAMERA;
615		if (i->index == 0) {
616			i->std = SKEL_TVNORMS;
617			strlcpy(i->name, "S-Video", sizeof(i->name));
618			i->capabilities = V4L2_IN_CAP_STD;
619		} else {
620			i->std = 0;
621			strlcpy(i->name, "HDMI", sizeof(i->name));
622			i->capabilities = V4L2_IN_CAP_DV_TIMINGS;
623		}
624		return 0;
625	}
626	
627	static int skeleton_s_input(struct file *file, void *priv, unsigned int i)
628	{
629		struct skeleton *skel = video_drvdata(file);
630	
631		if (i > 1)
632			return -EINVAL;
633	
634		/*
635		 * Changing the input implies a format change, which is not allowed
636		 * while buffers for use with streaming have already been allocated.
637		 */
638		if (vb2_is_busy(&skel->queue))
639			return -EBUSY;
640	
641		skel->input = i;
642		/*
643		 * Update tvnorms. The tvnorms value is used by the core to implement
644		 * VIDIOC_ENUMSTD so it has to be correct. If tvnorms == 0, then
645		 * ENUMSTD will return -ENODATA.
646		 */
647		skel->vdev.tvnorms = i ? 0 : SKEL_TVNORMS;
648	
649		/* Update the internal format */
650		skeleton_fill_pix_format(skel, &skel->format);
651		return 0;
652	}
653	
654	static int skeleton_g_input(struct file *file, void *priv, unsigned int *i)
655	{
656		struct skeleton *skel = video_drvdata(file);
657	
658		*i = skel->input;
659		return 0;
660	}
661	
662	/* The control handler. */
663	static int skeleton_s_ctrl(struct v4l2_ctrl *ctrl)
664	{
665		/*struct skeleton *skel =
666			container_of(ctrl->handler, struct skeleton, ctrl_handler);*/
667	
668		switch (ctrl->id) {
669		case V4L2_CID_BRIGHTNESS:
670			/* TODO: set brightness to ctrl->val */
671			break;
672		case V4L2_CID_CONTRAST:
673			/* TODO: set contrast to ctrl->val */
674			break;
675		case V4L2_CID_SATURATION:
676			/* TODO: set saturation to ctrl->val */
677			break;
678		case V4L2_CID_HUE:
679			/* TODO: set hue to ctrl->val */
680			break;
681		default:
682			return -EINVAL;
683		}
684		return 0;
685	}
686	
687	/* ------------------------------------------------------------------
688		File operations for the device
689	   ------------------------------------------------------------------*/
690	
691	static const struct v4l2_ctrl_ops skel_ctrl_ops = {
692		.s_ctrl = skeleton_s_ctrl,
693	};
694	
695	/*
696	 * The set of all supported ioctls. Note that all the streaming ioctls
697	 * use the vb2 helper functions that take care of all the locking and
698	 * that also do ownership tracking (i.e. only the filehandle that requested
699	 * the buffers can call the streaming ioctls, all other filehandles will
700	 * receive -EBUSY if they attempt to call the same streaming ioctls).
701	 *
702	 * The last three ioctls also use standard helper functions: these implement
703	 * standard behavior for drivers with controls.
704	 */
705	static const struct v4l2_ioctl_ops skel_ioctl_ops = {
706		.vidioc_querycap = skeleton_querycap,
707		.vidioc_try_fmt_vid_cap = skeleton_try_fmt_vid_cap,
708		.vidioc_s_fmt_vid_cap = skeleton_s_fmt_vid_cap,
709		.vidioc_g_fmt_vid_cap = skeleton_g_fmt_vid_cap,
710		.vidioc_enum_fmt_vid_cap = skeleton_enum_fmt_vid_cap,
711	
712		.vidioc_g_std = skeleton_g_std,
713		.vidioc_s_std = skeleton_s_std,
714		.vidioc_querystd = skeleton_querystd,
715	
716		.vidioc_s_dv_timings = skeleton_s_dv_timings,
717		.vidioc_g_dv_timings = skeleton_g_dv_timings,
718		.vidioc_enum_dv_timings = skeleton_enum_dv_timings,
719		.vidioc_query_dv_timings = skeleton_query_dv_timings,
720		.vidioc_dv_timings_cap = skeleton_dv_timings_cap,
721	
722		.vidioc_enum_input = skeleton_enum_input,
723		.vidioc_g_input = skeleton_g_input,
724		.vidioc_s_input = skeleton_s_input,
725	
726		.vidioc_reqbufs = vb2_ioctl_reqbufs,
727		.vidioc_create_bufs = vb2_ioctl_create_bufs,
728		.vidioc_querybuf = vb2_ioctl_querybuf,
729		.vidioc_qbuf = vb2_ioctl_qbuf,
730		.vidioc_dqbuf = vb2_ioctl_dqbuf,
731		.vidioc_expbuf = vb2_ioctl_expbuf,
732		.vidioc_streamon = vb2_ioctl_streamon,
733		.vidioc_streamoff = vb2_ioctl_streamoff,
734	
735		.vidioc_log_status = v4l2_ctrl_log_status,
736		.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
737		.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
738	};
739	
740	/*
741	 * The set of file operations. Note that all these ops are standard core
742	 * helper functions.
743	 */
744	static const struct v4l2_file_operations skel_fops = {
745		.owner = THIS_MODULE,
746		.open = v4l2_fh_open,
747		.release = vb2_fop_release,
748		.unlocked_ioctl = video_ioctl2,
749		.read = vb2_fop_read,
750		.mmap = vb2_fop_mmap,
751		.poll = vb2_fop_poll,
752	};
753	
754	/*
755	 * The initial setup of this device instance. Note that the initial state of
756	 * the driver should be complete. So the initial format, standard, timings
757	 * and video input should all be initialized to some reasonable value.
758	 */
759	static int skeleton_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
760	{
761		/* The initial timings are chosen to be 720p60. */
762		static const struct v4l2_dv_timings timings_def =
763			V4L2_DV_BT_CEA_1280X720P60;
764		struct skeleton *skel;
765		struct video_device *vdev;
766		struct v4l2_ctrl_handler *hdl;
767		struct vb2_queue *q;
768		int ret;
769	
770		/* Enable PCI */
771		ret = pci_enable_device(pdev);
772		if (ret)
773			return ret;
774		ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
775		if (ret) {
776			dev_err(&pdev->dev, "no suitable DMA available.\n");
777			goto disable_pci;
778		}
779	
780		/* Allocate a new instance */
781		skel = devm_kzalloc(&pdev->dev, sizeof(struct skeleton), GFP_KERNEL);
782		if (!skel)
783			return -ENOMEM;
784	
785		/* Allocate the interrupt */
786		ret = devm_request_irq(&pdev->dev, pdev->irq,
787				       skeleton_irq, 0, KBUILD_MODNAME, skel);
788		if (ret) {
789			dev_err(&pdev->dev, "request_irq failed\n");
790			goto disable_pci;
791		}
792		skel->pdev = pdev;
793	
794		/* Fill in the initial format-related settings */
795		skel->timings = timings_def;
796		skel->std = V4L2_STD_625_50;
797		skeleton_fill_pix_format(skel, &skel->format);
798	
799		/* Initialize the top-level structure */
800		ret = v4l2_device_register(&pdev->dev, &skel->v4l2_dev);
801		if (ret)
802			goto disable_pci;
803	
804		mutex_init(&skel->lock);
805	
806		/* Add the controls */
807		hdl = &skel->ctrl_handler;
808		v4l2_ctrl_handler_init(hdl, 4);
809		v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
810				  V4L2_CID_BRIGHTNESS, 0, 255, 1, 127);
811		v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
812				  V4L2_CID_CONTRAST, 0, 255, 1, 16);
813		v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
814				  V4L2_CID_SATURATION, 0, 255, 1, 127);
815		v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
816				  V4L2_CID_HUE, -128, 127, 1, 0);
817		if (hdl->error) {
818			ret = hdl->error;
819			goto free_hdl;
820		}
821		skel->v4l2_dev.ctrl_handler = hdl;
822	
823		/* Initialize the vb2 queue */
824		q = &skel->queue;
825		q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
826		q->io_modes = VB2_MMAP | VB2_DMABUF | VB2_READ;
827		q->drv_priv = skel;
828		q->buf_struct_size = sizeof(struct skel_buffer);
829		q->ops = &skel_qops;
830		q->mem_ops = &vb2_dma_contig_memops;
831		q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
832		/*
833		 * Assume that this DMA engine needs to have at least two buffers
834		 * available before it can be started. The start_streaming() op
835		 * won't be called until at least this many buffers are queued up.
836		 */
837		q->min_buffers_needed = 2;
838		/*
839		 * The serialization lock for the streaming ioctls. This is the same
840		 * as the main serialization lock, but if some of the non-streaming
841		 * ioctls could take a long time to execute, then you might want to
842		 * have a different lock here to prevent VIDIOC_DQBUF from being
843		 * blocked while waiting for another action to finish. This is
844		 * generally not needed for PCI devices, but USB devices usually do
845		 * want a separate lock here.
846		 */
847		q->lock = &skel->lock;
848		/*
849		 * Since this driver can only do 32-bit DMA we must make sure that
850		 * the vb2 core will allocate the buffers in 32-bit DMA memory.
851		 */
852		q->gfp_flags = GFP_DMA32;
853		ret = vb2_queue_init(q);
854		if (ret)
855			goto free_hdl;
856	
857		skel->alloc_ctx = vb2_dma_contig_init_ctx(&pdev->dev);
858		if (IS_ERR(skel->alloc_ctx)) {
859			dev_err(&pdev->dev, "Can't allocate buffer context");
860			ret = PTR_ERR(skel->alloc_ctx);
861			goto free_hdl;
862		}
863		INIT_LIST_HEAD(&skel->buf_list);
864		spin_lock_init(&skel->qlock);
865	
866		/* Initialize the video_device structure */
867		vdev = &skel->vdev;
868		strlcpy(vdev->name, KBUILD_MODNAME, sizeof(vdev->name));
869		/*
870		 * There is nothing to clean up, so release is set to an empty release
871		 * function. The release callback must be non-NULL.
872		 */
873		vdev->release = video_device_release_empty;
874		vdev->fops = &skel_fops,
875		vdev->ioctl_ops = &skel_ioctl_ops,
876		/*
877		 * The main serialization lock. All ioctls are serialized by this
878		 * lock. Exception: if q->lock is set, then the streaming ioctls
879		 * are serialized by that separate lock.
880		 */
881		vdev->lock = &skel->lock;
882		vdev->queue = q;
883		vdev->v4l2_dev = &skel->v4l2_dev;
884		/* Supported SDTV standards, if any */
885		vdev->tvnorms = SKEL_TVNORMS;
886		/* If this bit is set, then the v4l2 core will provide the support
887		 * for the VIDIOC_G/S_PRIORITY ioctls. This flag will eventually
888		 * go away once all drivers have been converted to use struct v4l2_fh.
889		 */
890		set_bit(V4L2_FL_USE_FH_PRIO, &vdev->flags);
891		video_set_drvdata(vdev, skel);
892	
893		ret = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
894		if (ret)
895			goto free_ctx;
896	
897		dev_info(&pdev->dev, "V4L2 PCI Skeleton Driver loaded\n");
898		return 0;
899	
900	free_ctx:
901		vb2_dma_contig_cleanup_ctx(skel->alloc_ctx);
902	free_hdl:
903		v4l2_ctrl_handler_free(&skel->ctrl_handler);
904		v4l2_device_unregister(&skel->v4l2_dev);
905	disable_pci:
906		pci_disable_device(pdev);
907		return ret;
908	}
909	
910	static void skeleton_remove(struct pci_dev *pdev)
911	{
912		struct v4l2_device *v4l2_dev = pci_get_drvdata(pdev);
913		struct skeleton *skel = container_of(v4l2_dev, struct skeleton, v4l2_dev);
914	
915		video_unregister_device(&skel->vdev);
916		v4l2_ctrl_handler_free(&skel->ctrl_handler);
917		vb2_dma_contig_cleanup_ctx(skel->alloc_ctx);
918		v4l2_device_unregister(&skel->v4l2_dev);
919		pci_disable_device(skel->pdev);
920	}
921	
922	static struct pci_driver skeleton_driver = {
923		.name = KBUILD_MODNAME,
924		.probe = skeleton_probe,
925		.remove = skeleton_remove,
926		.id_table = skeleton_pci_tbl,
927	};
928	
929	module_pci_driver(skeleton_driver);
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