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Based on kernel version 3.15.4. Page generated on 2014-07-07 09:05 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 int sequence;
81	};
82	
83	struct skel_buffer {
84		struct vb2_buffer vb;
85		struct list_head list;
86	};
87	
88	static inline struct skel_buffer *to_skel_buffer(struct vb2_buffer *vb2)
89	{
90		return container_of(vb2, struct skel_buffer, vb);
91	}
92	
93	static const struct pci_device_id skeleton_pci_tbl[] = {
94		/* { PCI_DEVICE(PCI_VENDOR_ID_, PCI_DEVICE_ID_) }, */
95		{ 0, }
96	};
97	
98	/*
99	 * HDTV: this structure has the capabilities of the HDTV receiver.
100	 * It is used to constrain the huge list of possible formats based
101	 * upon the hardware capabilities.
102	 */
103	static const struct v4l2_dv_timings_cap skel_timings_cap = {
104		.type = V4L2_DV_BT_656_1120,
105		/* keep this initialization for compatibility with GCC < 4.4.6 */
106		.reserved = { 0 },
107		V4L2_INIT_BT_TIMINGS(
108			720, 1920,		/* min/max width */
109			480, 1080,		/* min/max height */
110			27000000, 74250000,	/* min/max pixelclock*/
111			V4L2_DV_BT_STD_CEA861,	/* Supported standards */
112			/* capabilities */
113			V4L2_DV_BT_CAP_INTERLACED | V4L2_DV_BT_CAP_PROGRESSIVE
114		)
115	};
116	
117	/*
118	 * Supported SDTV standards. This does the same job as skel_timings_cap, but
119	 * for standard TV formats.
120	 */
121	#define SKEL_TVNORMS V4L2_STD_ALL
122	
123	/*
124	 * Interrupt handler: typically interrupts happen after a new frame has been
125	 * captured. It is the job of the handler to remove the new frame from the
126	 * internal list and give it back to the vb2 framework, updating the sequence
127	 * counter and timestamp at the same time.
128	 */
129	static irqreturn_t skeleton_irq(int irq, void *dev_id)
130	{
131	#ifdef TODO
132		struct skeleton *skel = dev_id;
133	
134		/* handle interrupt */
135	
136		/* Once a new frame has been captured, mark it as done like this: */
137		if (captured_new_frame) {
138			...
139			spin_lock(&skel->qlock);
140			list_del(&new_buf->list);
141			spin_unlock(&skel->qlock);
142			new_buf->vb.v4l2_buf.sequence = skel->sequence++;
143			v4l2_get_timestamp(&new_buf->vb.v4l2_buf.timestamp);
144			vb2_buffer_done(&new_buf->vb, VB2_BUF_STATE_DONE);
145		}
146	#endif
147		return IRQ_HANDLED;
148	}
149	
150	/*
151	 * Setup the constraints of the queue: besides setting the number of planes
152	 * per buffer and the size and allocation context of each plane, it also
153	 * checks if sufficient buffers have been allocated. Usually 3 is a good
154	 * minimum number: many DMA engines need a minimum of 2 buffers in the
155	 * queue and you need to have another available for userspace processing.
156	 */
157	static int queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt,
158			       unsigned int *nbuffers, unsigned int *nplanes,
159			       unsigned int sizes[], void *alloc_ctxs[])
160	{
161		struct skeleton *skel = vb2_get_drv_priv(vq);
162	
163		if (vq->num_buffers + *nbuffers < 3)
164			*nbuffers = 3 - vq->num_buffers;
165	
166		if (fmt && fmt->fmt.pix.sizeimage < skel->format.sizeimage)
167			return -EINVAL;
168		*nplanes = 1;
169		sizes[0] = fmt ? fmt->fmt.pix.sizeimage : skel->format.sizeimage;
170		alloc_ctxs[0] = skel->alloc_ctx;
171		return 0;
172	}
173	
174	/*
175	 * Prepare the buffer for queueing to the DMA engine: check and set the
176	 * payload size and fill in the field. Note: if the format's field is
177	 * V4L2_FIELD_ALTERNATE, then vb->v4l2_buf.field should be set in the
178	 * interrupt handler since that's usually where you know if the TOP or
179	 * BOTTOM field has been captured.
180	 */
181	static int buffer_prepare(struct vb2_buffer *vb)
182	{
183		struct skeleton *skel = vb2_get_drv_priv(vb->vb2_queue);
184		unsigned long size = skel->format.sizeimage;
185	
186		if (vb2_plane_size(vb, 0) < size) {
187			dev_err(&skel->pdev->dev, "buffer too small (%lu < %lu)\n",
188				 vb2_plane_size(vb, 0), size);
189			return -EINVAL;
190		}
191	
192		vb2_set_plane_payload(vb, 0, size);
193		vb->v4l2_buf.field = skel->format.field;
194		return 0;
195	}
196	
197	/*
198	 * Queue this buffer to the DMA engine.
199	 */
200	static void buffer_queue(struct vb2_buffer *vb)
201	{
202		struct skeleton *skel = vb2_get_drv_priv(vb->vb2_queue);
203		struct skel_buffer *buf = to_skel_buffer(vb);
204		unsigned long flags;
205	
206		spin_lock_irqsave(&skel->qlock, flags);
207		list_add_tail(&buf->list, &skel->buf_list);
208	
209		/* TODO: Update any DMA pointers if necessary */
210	
211		spin_unlock_irqrestore(&skel->qlock, flags);
212	}
213	
214	static void return_all_buffers(struct skeleton *skel,
215				       enum vb2_buffer_state state)
216	{
217		struct skel_buffer *buf, *node;
218		unsigned long flags;
219	
220		spin_lock_irqsave(&skel->qlock, flags);
221		list_for_each_entry_safe(buf, node, &skel->buf_list, list) {
222			vb2_buffer_done(&buf->vb, state);
223			list_del(&buf->list);
224		}
225		spin_unlock_irqrestore(&skel->qlock, flags);
226	}
227	
228	/*
229	 * Start streaming. First check if the minimum number of buffers have been
230	 * queued. If not, then return -ENOBUFS and the vb2 framework will call
231	 * this function again the next time a buffer has been queued until enough
232	 * buffers are available to actually start the DMA engine.
233	 */
234	static int start_streaming(struct vb2_queue *vq, unsigned int count)
235	{
236		struct skeleton *skel = vb2_get_drv_priv(vq);
237		int ret = 0;
238	
239		skel->sequence = 0;
240	
241		/* TODO: start DMA */
242	
243		if (ret) {
244			/*
245			 * In case of an error, return all active buffers to the
246			 * QUEUED state
247			 */
248			return_all_buffers(skel, VB2_BUF_STATE_QUEUED);
249		}
250		return ret;
251	}
252	
253	/*
254	 * Stop the DMA engine. Any remaining buffers in the DMA queue are dequeued
255	 * and passed on to the vb2 framework marked as STATE_ERROR.
256	 */
257	static int stop_streaming(struct vb2_queue *vq)
258	{
259		struct skeleton *skel = vb2_get_drv_priv(vq);
260	
261		/* TODO: stop DMA */
262	
263		/* Release all active buffers */
264		return_all_buffers(skel, VB2_BUF_STATE_ERROR);
265		return 0;
266	}
267	
268	/*
269	 * The vb2 queue ops. Note that since q->lock is set we can use the standard
270	 * vb2_ops_wait_prepare/finish helper functions. If q->lock would be NULL,
271	 * then this driver would have to provide these ops.
272	 */
273	static struct vb2_ops skel_qops = {
274		.queue_setup		= queue_setup,
275		.buf_prepare		= buffer_prepare,
276		.buf_queue		= buffer_queue,
277		.start_streaming	= start_streaming,
278		.stop_streaming		= stop_streaming,
279		.wait_prepare		= vb2_ops_wait_prepare,
280		.wait_finish		= vb2_ops_wait_finish,
281	};
282	
283	/*
284	 * Required ioctl querycap. Note that the version field is prefilled with
285	 * the version of the kernel.
286	 */
287	static int skeleton_querycap(struct file *file, void *priv,
288				     struct v4l2_capability *cap)
289	{
290		struct skeleton *skel = video_drvdata(file);
291	
292		strlcpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver));
293		strlcpy(cap->card, "V4L2 PCI Skeleton", sizeof(cap->card));
294		snprintf(cap->bus_info, sizeof(cap->bus_info), "PCI:%s",
295			 pci_name(skel->pdev));
296		cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE |
297				   V4L2_CAP_STREAMING;
298		cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
299		return 0;
300	}
301	
302	/*
303	 * Helper function to check and correct struct v4l2_pix_format. It's used
304	 * not only in VIDIOC_TRY/S_FMT, but also elsewhere if changes to the SDTV
305	 * standard, HDTV timings or the video input would require updating the
306	 * current format.
307	 */
308	static void skeleton_fill_pix_format(struct skeleton *skel,
309					     struct v4l2_pix_format *pix)
310	{
311		pix->pixelformat = V4L2_PIX_FMT_YUYV;
312		if (skel->input == 0) {
313			/* S-Video input */
314			pix->width = 720;
315			pix->height = (skel->std & V4L2_STD_525_60) ? 480 : 576;
316			pix->field = V4L2_FIELD_INTERLACED;
317			pix->colorspace = V4L2_COLORSPACE_SMPTE170M;
318		} else {
319			/* HDMI input */
320			pix->width = skel->timings.bt.width;
321			pix->height = skel->timings.bt.height;
322			if (skel->timings.bt.interlaced)
323				pix->field = V4L2_FIELD_INTERLACED;
324			else
325				pix->field = V4L2_FIELD_NONE;
326			pix->colorspace = V4L2_COLORSPACE_REC709;
327		}
328	
329		/*
330		 * The YUYV format is four bytes for every two pixels, so bytesperline
331		 * is width * 2.
332		 */
333		pix->bytesperline = pix->width * 2;
334		pix->sizeimage = pix->bytesperline * pix->height;
335		pix->priv = 0;
336	}
337	
338	static int skeleton_try_fmt_vid_cap(struct file *file, void *priv,
339					    struct v4l2_format *f)
340	{
341		struct skeleton *skel = video_drvdata(file);
342		struct v4l2_pix_format *pix = &f->fmt.pix;
343	
344		/*
345		 * Due to historical reasons providing try_fmt with an unsupported
346		 * pixelformat will return -EINVAL for video receivers. Webcam drivers,
347		 * however, will silently correct the pixelformat. Some video capture
348		 * applications rely on this behavior...
349		 */
350		if (pix->pixelformat != V4L2_PIX_FMT_YUYV)
351			return -EINVAL;
352		skeleton_fill_pix_format(skel, pix);
353		return 0;
354	}
355	
356	static int skeleton_s_fmt_vid_cap(struct file *file, void *priv,
357					  struct v4l2_format *f)
358	{
359		struct skeleton *skel = video_drvdata(file);
360		int ret;
361	
362		ret = skeleton_try_fmt_vid_cap(file, priv, f);
363		if (ret)
364			return ret;
365	
366		/*
367		 * It is not allowed to change the format while buffers for use with
368		 * streaming have already been allocated.
369		 */
370		if (vb2_is_busy(&skel->queue))
371			return -EBUSY;
372	
373		/* TODO: change format */
374		skel->format = f->fmt.pix;
375		return 0;
376	}
377	
378	static int skeleton_g_fmt_vid_cap(struct file *file, void *priv,
379					  struct v4l2_format *f)
380	{
381		struct skeleton *skel = video_drvdata(file);
382	
383		f->fmt.pix = skel->format;
384		return 0;
385	}
386	
387	static int skeleton_enum_fmt_vid_cap(struct file *file, void *priv,
388					     struct v4l2_fmtdesc *f)
389	{
390		if (f->index != 0)
391			return -EINVAL;
392	
393		strlcpy(f->description, "4:2:2, packed, YUYV", sizeof(f->description));
394		f->pixelformat = V4L2_PIX_FMT_YUYV;
395		f->flags = 0;
396		return 0;
397	}
398	
399	static int skeleton_s_std(struct file *file, void *priv, v4l2_std_id std)
400	{
401		struct skeleton *skel = video_drvdata(file);
402	
403		/* S_STD is not supported on the HDMI input */
404		if (skel->input)
405			return -ENODATA;
406	
407		/*
408		 * No change, so just return. Some applications call S_STD again after
409		 * the buffers for streaming have been set up, so we have to allow for
410		 * this behavior.
411		 */
412		if (std == skel->std)
413			return 0;
414	
415		/*
416		 * Changing the standard implies a format change, which is not allowed
417		 * while buffers for use with streaming have already been allocated.
418		 */
419		if (vb2_is_busy(&skel->queue))
420			return -EBUSY;
421	
422		/* TODO: handle changing std */
423	
424		skel->std = std;
425	
426		/* Update the internal format */
427		skeleton_fill_pix_format(skel, &skel->format);
428		return 0;
429	}
430	
431	static int skeleton_g_std(struct file *file, void *priv, v4l2_std_id *std)
432	{
433		struct skeleton *skel = video_drvdata(file);
434	
435		/* G_STD is not supported on the HDMI input */
436		if (skel->input)
437			return -ENODATA;
438	
439		*std = skel->std;
440		return 0;
441	}
442	
443	/*
444	 * Query the current standard as seen by the hardware. This function shall
445	 * never actually change the standard, it just detects and reports.
446	 * The framework will initially set *std to tvnorms (i.e. the set of
447	 * supported standards by this input), and this function should just AND
448	 * this value. If there is no signal, then *std should be set to 0.
449	 */
450	static int skeleton_querystd(struct file *file, void *priv, v4l2_std_id *std)
451	{
452		struct skeleton *skel = video_drvdata(file);
453	
454		/* QUERY_STD is not supported on the HDMI input */
455		if (skel->input)
456			return -ENODATA;
457	
458	#ifdef TODO
459		/*
460		 * Query currently seen standard. Initial value of *std is
461		 * V4L2_STD_ALL. This function should look something like this:
462		 */
463		get_signal_info();
464		if (no_signal) {
465			*std = 0;
466			return 0;
467		}
468		/* Use signal information to reduce the number of possible standards */
469		if (signal_has_525_lines)
470			*std &= V4L2_STD_525_60;
471		else
472			*std &= V4L2_STD_625_50;
473	#endif
474		return 0;
475	}
476	
477	static int skeleton_s_dv_timings(struct file *file, void *_fh,
478					 struct v4l2_dv_timings *timings)
479	{
480		struct skeleton *skel = video_drvdata(file);
481	
482		/* S_DV_TIMINGS is not supported on the S-Video input */
483		if (skel->input == 0)
484			return -ENODATA;
485	
486		/* Quick sanity check */
487		if (!v4l2_valid_dv_timings(timings, &skel_timings_cap, NULL, NULL))
488			return -EINVAL;
489	
490		/* Check if the timings are part of the CEA-861 timings. */
491		if (!v4l2_find_dv_timings_cap(timings, &skel_timings_cap,
492					      0, NULL, NULL))
493			return -EINVAL;
494	
495		/* Return 0 if the new timings are the same as the current timings. */
496		if (v4l2_match_dv_timings(timings, &skel->timings, 0))
497			return 0;
498	
499		/*
500		 * Changing the timings implies a format change, which is not allowed
501		 * while buffers for use with streaming have already been allocated.
502		 */
503		if (vb2_is_busy(&skel->queue))
504			return -EBUSY;
505	
506		/* TODO: Configure new timings */
507	
508		/* Save timings */
509		skel->timings = *timings;
510	
511		/* Update the internal format */
512		skeleton_fill_pix_format(skel, &skel->format);
513		return 0;
514	}
515	
516	static int skeleton_g_dv_timings(struct file *file, void *_fh,
517					 struct v4l2_dv_timings *timings)
518	{
519		struct skeleton *skel = video_drvdata(file);
520	
521		/* G_DV_TIMINGS is not supported on the S-Video input */
522		if (skel->input == 0)
523			return -ENODATA;
524	
525		*timings = skel->timings;
526		return 0;
527	}
528	
529	static int skeleton_enum_dv_timings(struct file *file, void *_fh,
530					    struct v4l2_enum_dv_timings *timings)
531	{
532		struct skeleton *skel = video_drvdata(file);
533	
534		/* ENUM_DV_TIMINGS is not supported on the S-Video input */
535		if (skel->input == 0)
536			return -ENODATA;
537	
538		return v4l2_enum_dv_timings_cap(timings, &skel_timings_cap,
539						NULL, NULL);
540	}
541	
542	/*
543	 * Query the current timings as seen by the hardware. This function shall
544	 * never actually change the timings, it just detects and reports.
545	 * If no signal is detected, then return -ENOLINK. If the hardware cannot
546	 * lock to the signal, then return -ENOLCK. If the signal is out of range
547	 * of the capabilities of the system (e.g., it is possible that the receiver
548	 * can lock but that the DMA engine it is connected to cannot handle
549	 * pixelclocks above a certain frequency), then -ERANGE is returned.
550	 */
551	static int skeleton_query_dv_timings(struct file *file, void *_fh,
552					     struct v4l2_dv_timings *timings)
553	{
554		struct skeleton *skel = video_drvdata(file);
555	
556		/* QUERY_DV_TIMINGS is not supported on the S-Video input */
557		if (skel->input == 0)
558			return -ENODATA;
559	
560	#ifdef TODO
561		/*
562		 * Query currently seen timings. This function should look
563		 * something like this:
564		 */
565		detect_timings();
566		if (no_signal)
567			return -ENOLINK;
568		if (cannot_lock_to_signal)
569			return -ENOLCK;
570		if (signal_out_of_range_of_capabilities)
571			return -ERANGE;
572	
573		/* Useful for debugging */
574		v4l2_print_dv_timings(skel->v4l2_dev.name, "query_dv_timings:",
575				timings, true);
576	#endif
577		return 0;
578	}
579	
580	static int skeleton_dv_timings_cap(struct file *file, void *fh,
581					   struct v4l2_dv_timings_cap *cap)
582	{
583		struct skeleton *skel = video_drvdata(file);
584	
585		/* DV_TIMINGS_CAP is not supported on the S-Video input */
586		if (skel->input == 0)
587			return -ENODATA;
588		*cap = skel_timings_cap;
589		return 0;
590	}
591	
592	static int skeleton_enum_input(struct file *file, void *priv,
593				       struct v4l2_input *i)
594	{
595		if (i->index > 1)
596			return -EINVAL;
597	
598		i->type = V4L2_INPUT_TYPE_CAMERA;
599		if (i->index == 0) {
600			i->std = SKEL_TVNORMS;
601			strlcpy(i->name, "S-Video", sizeof(i->name));
602			i->capabilities = V4L2_IN_CAP_STD;
603		} else {
604			i->std = 0;
605			strlcpy(i->name, "HDMI", sizeof(i->name));
606			i->capabilities = V4L2_IN_CAP_DV_TIMINGS;
607		}
608		return 0;
609	}
610	
611	static int skeleton_s_input(struct file *file, void *priv, unsigned int i)
612	{
613		struct skeleton *skel = video_drvdata(file);
614	
615		if (i > 1)
616			return -EINVAL;
617	
618		/*
619		 * Changing the input implies a format change, which is not allowed
620		 * while buffers for use with streaming have already been allocated.
621		 */
622		if (vb2_is_busy(&skel->queue))
623			return -EBUSY;
624	
625		skel->input = i;
626		/*
627		 * Update tvnorms. The tvnorms value is used by the core to implement
628		 * VIDIOC_ENUMSTD so it has to be correct. If tvnorms == 0, then
629		 * ENUMSTD will return -ENODATA.
630		 */
631		skel->vdev.tvnorms = i ? 0 : SKEL_TVNORMS;
632	
633		/* Update the internal format */
634		skeleton_fill_pix_format(skel, &skel->format);
635		return 0;
636	}
637	
638	static int skeleton_g_input(struct file *file, void *priv, unsigned int *i)
639	{
640		struct skeleton *skel = video_drvdata(file);
641	
642		*i = skel->input;
643		return 0;
644	}
645	
646	/* The control handler. */
647	static int skeleton_s_ctrl(struct v4l2_ctrl *ctrl)
648	{
649		/*struct skeleton *skel =
650			container_of(ctrl->handler, struct skeleton, ctrl_handler);*/
651	
652		switch (ctrl->id) {
653		case V4L2_CID_BRIGHTNESS:
654			/* TODO: set brightness to ctrl->val */
655			break;
656		case V4L2_CID_CONTRAST:
657			/* TODO: set contrast to ctrl->val */
658			break;
659		case V4L2_CID_SATURATION:
660			/* TODO: set saturation to ctrl->val */
661			break;
662		case V4L2_CID_HUE:
663			/* TODO: set hue to ctrl->val */
664			break;
665		default:
666			return -EINVAL;
667		}
668		return 0;
669	}
670	
671	/* ------------------------------------------------------------------
672		File operations for the device
673	   ------------------------------------------------------------------*/
674	
675	static const struct v4l2_ctrl_ops skel_ctrl_ops = {
676		.s_ctrl = skeleton_s_ctrl,
677	};
678	
679	/*
680	 * The set of all supported ioctls. Note that all the streaming ioctls
681	 * use the vb2 helper functions that take care of all the locking and
682	 * that also do ownership tracking (i.e. only the filehandle that requested
683	 * the buffers can call the streaming ioctls, all other filehandles will
684	 * receive -EBUSY if they attempt to call the same streaming ioctls).
685	 *
686	 * The last three ioctls also use standard helper functions: these implement
687	 * standard behavior for drivers with controls.
688	 */
689	static const struct v4l2_ioctl_ops skel_ioctl_ops = {
690		.vidioc_querycap = skeleton_querycap,
691		.vidioc_try_fmt_vid_cap = skeleton_try_fmt_vid_cap,
692		.vidioc_s_fmt_vid_cap = skeleton_s_fmt_vid_cap,
693		.vidioc_g_fmt_vid_cap = skeleton_g_fmt_vid_cap,
694		.vidioc_enum_fmt_vid_cap = skeleton_enum_fmt_vid_cap,
695	
696		.vidioc_g_std = skeleton_g_std,
697		.vidioc_s_std = skeleton_s_std,
698		.vidioc_querystd = skeleton_querystd,
699	
700		.vidioc_s_dv_timings = skeleton_s_dv_timings,
701		.vidioc_g_dv_timings = skeleton_g_dv_timings,
702		.vidioc_enum_dv_timings = skeleton_enum_dv_timings,
703		.vidioc_query_dv_timings = skeleton_query_dv_timings,
704		.vidioc_dv_timings_cap = skeleton_dv_timings_cap,
705	
706		.vidioc_enum_input = skeleton_enum_input,
707		.vidioc_g_input = skeleton_g_input,
708		.vidioc_s_input = skeleton_s_input,
709	
710		.vidioc_reqbufs = vb2_ioctl_reqbufs,
711		.vidioc_create_bufs = vb2_ioctl_create_bufs,
712		.vidioc_querybuf = vb2_ioctl_querybuf,
713		.vidioc_qbuf = vb2_ioctl_qbuf,
714		.vidioc_dqbuf = vb2_ioctl_dqbuf,
715		.vidioc_expbuf = vb2_ioctl_expbuf,
716		.vidioc_streamon = vb2_ioctl_streamon,
717		.vidioc_streamoff = vb2_ioctl_streamoff,
718	
719		.vidioc_log_status = v4l2_ctrl_log_status,
720		.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
721		.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
722	};
723	
724	/*
725	 * The set of file operations. Note that all these ops are standard core
726	 * helper functions.
727	 */
728	static const struct v4l2_file_operations skel_fops = {
729		.owner = THIS_MODULE,
730		.open = v4l2_fh_open,
731		.release = vb2_fop_release,
732		.unlocked_ioctl = video_ioctl2,
733		.read = vb2_fop_read,
734		.mmap = vb2_fop_mmap,
735		.poll = vb2_fop_poll,
736	};
737	
738	/*
739	 * The initial setup of this device instance. Note that the initial state of
740	 * the driver should be complete. So the initial format, standard, timings
741	 * and video input should all be initialized to some reasonable value.
742	 */
743	static int skeleton_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
744	{
745		/* The initial timings are chosen to be 720p60. */
746		static const struct v4l2_dv_timings timings_def =
747			V4L2_DV_BT_CEA_1280X720P60;
748		struct skeleton *skel;
749		struct video_device *vdev;
750		struct v4l2_ctrl_handler *hdl;
751		struct vb2_queue *q;
752		int ret;
753	
754		/* Enable PCI */
755		ret = pci_enable_device(pdev);
756		if (ret)
757			return ret;
758		ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
759		if (ret) {
760			dev_err(&pdev->dev, "no suitable DMA available.\n");
761			goto disable_pci;
762		}
763	
764		/* Allocate a new instance */
765		skel = devm_kzalloc(&pdev->dev, sizeof(struct skeleton), GFP_KERNEL);
766		if (!skel)
767			return -ENOMEM;
768	
769		/* Allocate the interrupt */
770		ret = devm_request_irq(&pdev->dev, pdev->irq,
771				       skeleton_irq, 0, KBUILD_MODNAME, skel);
772		if (ret) {
773			dev_err(&pdev->dev, "request_irq failed\n");
774			goto disable_pci;
775		}
776		skel->pdev = pdev;
777	
778		/* Fill in the initial format-related settings */
779		skel->timings = timings_def;
780		skel->std = V4L2_STD_625_50;
781		skeleton_fill_pix_format(skel, &skel->format);
782	
783		/* Initialize the top-level structure */
784		ret = v4l2_device_register(&pdev->dev, &skel->v4l2_dev);
785		if (ret)
786			goto disable_pci;
787	
788		mutex_init(&skel->lock);
789	
790		/* Add the controls */
791		hdl = &skel->ctrl_handler;
792		v4l2_ctrl_handler_init(hdl, 4);
793		v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
794				  V4L2_CID_BRIGHTNESS, 0, 255, 1, 127);
795		v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
796				  V4L2_CID_CONTRAST, 0, 255, 1, 16);
797		v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
798				  V4L2_CID_SATURATION, 0, 255, 1, 127);
799		v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
800				  V4L2_CID_HUE, -128, 127, 1, 0);
801		if (hdl->error) {
802			ret = hdl->error;
803			goto free_hdl;
804		}
805		skel->v4l2_dev.ctrl_handler = hdl;
806	
807		/* Initialize the vb2 queue */
808		q = &skel->queue;
809		q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
810		q->io_modes = VB2_MMAP | VB2_DMABUF | VB2_READ;
811		q->drv_priv = skel;
812		q->buf_struct_size = sizeof(struct skel_buffer);
813		q->ops = &skel_qops;
814		q->mem_ops = &vb2_dma_contig_memops;
815		q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
816		/*
817		 * Assume that this DMA engine needs to have at least two buffers
818		 * available before it can be started. The start_streaming() op
819		 * won't be called until at least this many buffers are queued up.
820		 */
821		q->min_buffers_needed = 2;
822		/*
823		 * The serialization lock for the streaming ioctls. This is the same
824		 * as the main serialization lock, but if some of the non-streaming
825		 * ioctls could take a long time to execute, then you might want to
826		 * have a different lock here to prevent VIDIOC_DQBUF from being
827		 * blocked while waiting for another action to finish. This is
828		 * generally not needed for PCI devices, but USB devices usually do
829		 * want a separate lock here.
830		 */
831		q->lock = &skel->lock;
832		/*
833		 * Since this driver can only do 32-bit DMA we must make sure that
834		 * the vb2 core will allocate the buffers in 32-bit DMA memory.
835		 */
836		q->gfp_flags = GFP_DMA32;
837		ret = vb2_queue_init(q);
838		if (ret)
839			goto free_hdl;
840	
841		skel->alloc_ctx = vb2_dma_contig_init_ctx(&pdev->dev);
842		if (IS_ERR(skel->alloc_ctx)) {
843			dev_err(&pdev->dev, "Can't allocate buffer context");
844			ret = PTR_ERR(skel->alloc_ctx);
845			goto free_hdl;
846		}
847		INIT_LIST_HEAD(&skel->buf_list);
848		spin_lock_init(&skel->qlock);
849	
850		/* Initialize the video_device structure */
851		vdev = &skel->vdev;
852		strlcpy(vdev->name, KBUILD_MODNAME, sizeof(vdev->name));
853		/*
854		 * There is nothing to clean up, so release is set to an empty release
855		 * function. The release callback must be non-NULL.
856		 */
857		vdev->release = video_device_release_empty;
858		vdev->fops = &skel_fops,
859		vdev->ioctl_ops = &skel_ioctl_ops,
860		/*
861		 * The main serialization lock. All ioctls are serialized by this
862		 * lock. Exception: if q->lock is set, then the streaming ioctls
863		 * are serialized by that separate lock.
864		 */
865		vdev->lock = &skel->lock;
866		vdev->queue = q;
867		vdev->v4l2_dev = &skel->v4l2_dev;
868		/* Supported SDTV standards, if any */
869		vdev->tvnorms = SKEL_TVNORMS;
870		/* If this bit is set, then the v4l2 core will provide the support
871		 * for the VIDIOC_G/S_PRIORITY ioctls. This flag will eventually
872		 * go away once all drivers have been converted to use struct v4l2_fh.
873		 */
874		set_bit(V4L2_FL_USE_FH_PRIO, &vdev->flags);
875		video_set_drvdata(vdev, skel);
876	
877		ret = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
878		if (ret)
879			goto free_ctx;
880	
881		dev_info(&pdev->dev, "V4L2 PCI Skeleton Driver loaded\n");
882		return 0;
883	
884	free_ctx:
885		vb2_dma_contig_cleanup_ctx(skel->alloc_ctx);
886	free_hdl:
887		v4l2_ctrl_handler_free(&skel->ctrl_handler);
888		v4l2_device_unregister(&skel->v4l2_dev);
889	disable_pci:
890		pci_disable_device(pdev);
891		return ret;
892	}
893	
894	static void skeleton_remove(struct pci_dev *pdev)
895	{
896		struct v4l2_device *v4l2_dev = pci_get_drvdata(pdev);
897		struct skeleton *skel = container_of(v4l2_dev, struct skeleton, v4l2_dev);
898	
899		video_unregister_device(&skel->vdev);
900		v4l2_ctrl_handler_free(&skel->ctrl_handler);
901		vb2_dma_contig_cleanup_ctx(skel->alloc_ctx);
902		v4l2_device_unregister(&skel->v4l2_dev);
903		pci_disable_device(skel->pdev);
904	}
905	
906	static struct pci_driver skeleton_driver = {
907		.name = KBUILD_MODNAME,
908		.probe = skeleton_probe,
909		.remove = skeleton_remove,
910		.id_table = skeleton_pci_tbl,
911	};
912	
913	module_pci_driver(skeleton_driver);
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