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-v4l2.h>
41 #include <media/videobuf2-dma-contig.h>
42 
43 MODULE_DESCRIPTION("V4L2 PCI Skeleton Driver");
44 MODULE_AUTHOR("Hans Verkuil");
45 MODULE_LICENSE("GPL v2");
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  * @qlock: spinlock controlling access to buf_list and sequence
60  * @buf_list: list of buffers queued for DMA
61  * @field: the field (TOP/BOTTOM/other) of the current buffer
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 
77 	spinlock_t qlock;
78 	struct list_head buf_list;
79 	unsigned field;
80 	unsigned sequence;
81 };
82 
83 struct skel_buffer {
84 	struct vb2_v4l2_buffer vb;
85 	struct list_head list;
86 };
87 
88 static inline struct skel_buffer *to_skel_buffer(struct vb2_v4l2_buffer *vbuf)
89 {
90 	return container_of(vbuf, 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 MODULE_DEVICE_TABLE(pci, skeleton_pci_tbl);
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 		new_buf->vb.vb2_buf.timestamp = ktime_get_ns();
144 		new_buf->vb.sequence = skel->sequence++;
145 		new_buf->vb.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, 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,
166 		       unsigned int *nbuffers, unsigned int *nplanes,
167 		       unsigned int sizes[], struct device *alloc_devs[])
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 (*nplanes)
186 		return sizes[0] < skel->format.sizeimage ? -EINVAL : 0;
187 	*nplanes = 1;
188 	sizes[0] = skel->format.sizeimage;
189 	return 0;
190 }
191 
192 /*
193  * Prepare the buffer for queueing to the DMA engine: check and set the
194  * payload size.
195  */
196 static int buffer_prepare(struct vb2_buffer *vb)
197 {
198 	struct skeleton *skel = vb2_get_drv_priv(vb->vb2_queue);
199 	unsigned long size = skel->format.sizeimage;
200 
201 	if (vb2_plane_size(vb, 0) < size) {
202 		dev_err(&skel->pdev->dev, "buffer too small (%lu < %lu)\n",
203 			 vb2_plane_size(vb, 0), size);
204 		return -EINVAL;
205 	}
206 
207 	vb2_set_plane_payload(vb, 0, size);
208 	return 0;
209 }
210 
211 /*
212  * Queue this buffer to the DMA engine.
213  */
214 static void buffer_queue(struct vb2_buffer *vb)
215 {
216 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
217 	struct skeleton *skel = vb2_get_drv_priv(vb->vb2_queue);
218 	struct skel_buffer *buf = to_skel_buffer(vbuf);
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.vb2_buf, 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 const 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 	return 0;
311 }
312 
313 /*
314  * Helper function to check and correct struct v4l2_pix_format. It's used
315  * not only in VIDIOC_TRY/S_FMT, but also elsewhere if changes to the SDTV
316  * standard, HDTV timings or the video input would require updating the
317  * current format.
318  */
319 static void skeleton_fill_pix_format(struct skeleton *skel,
320 				     struct v4l2_pix_format *pix)
321 {
322 	pix->pixelformat = V4L2_PIX_FMT_YUYV;
323 	if (skel->input == 0) {
324 		/* S-Video input */
325 		pix->width = 720;
326 		pix->height = (skel->std & V4L2_STD_525_60) ? 480 : 576;
327 		pix->field = V4L2_FIELD_INTERLACED;
328 		pix->colorspace = V4L2_COLORSPACE_SMPTE170M;
329 	} else {
330 		/* HDMI input */
331 		pix->width = skel->timings.bt.width;
332 		pix->height = skel->timings.bt.height;
333 		if (skel->timings.bt.interlaced) {
334 			pix->field = V4L2_FIELD_ALTERNATE;
335 			pix->height /= 2;
336 		} else {
337 			pix->field = V4L2_FIELD_NONE;
338 		}
339 		pix->colorspace = V4L2_COLORSPACE_REC709;
340 	}
341 
342 	/*
343 	 * The YUYV format is four bytes for every two pixels, so bytesperline
344 	 * is width * 2.
345 	 */
346 	pix->bytesperline = pix->width * 2;
347 	pix->sizeimage = pix->bytesperline * pix->height;
348 	pix->priv = 0;
349 }
350 
351 static int skeleton_try_fmt_vid_cap(struct file *file, void *priv,
352 				    struct v4l2_format *f)
353 {
354 	struct skeleton *skel = video_drvdata(file);
355 	struct v4l2_pix_format *pix = &f->fmt.pix;
356 
357 	/*
358 	 * Due to historical reasons providing try_fmt with an unsupported
359 	 * pixelformat will return -EINVAL for video receivers. Webcam drivers,
360 	 * however, will silently correct the pixelformat. Some video capture
361 	 * applications rely on this behavior...
362 	 */
363 	if (pix->pixelformat != V4L2_PIX_FMT_YUYV)
364 		return -EINVAL;
365 	skeleton_fill_pix_format(skel, pix);
366 	return 0;
367 }
368 
369 static int skeleton_s_fmt_vid_cap(struct file *file, void *priv,
370 				  struct v4l2_format *f)
371 {
372 	struct skeleton *skel = video_drvdata(file);
373 	int ret;
374 
375 	ret = skeleton_try_fmt_vid_cap(file, priv, f);
376 	if (ret)
377 		return ret;
378 
379 	/*
380 	 * It is not allowed to change the format while buffers for use with
381 	 * streaming have already been allocated.
382 	 */
383 	if (vb2_is_busy(&skel->queue))
384 		return -EBUSY;
385 
386 	/* TODO: change format */
387 	skel->format = f->fmt.pix;
388 	return 0;
389 }
390 
391 static int skeleton_g_fmt_vid_cap(struct file *file, void *priv,
392 				  struct v4l2_format *f)
393 {
394 	struct skeleton *skel = video_drvdata(file);
395 
396 	f->fmt.pix = skel->format;
397 	return 0;
398 }
399 
400 static int skeleton_enum_fmt_vid_cap(struct file *file, void *priv,
401 				     struct v4l2_fmtdesc *f)
402 {
403 	if (f->index != 0)
404 		return -EINVAL;
405 
406 	f->pixelformat = V4L2_PIX_FMT_YUYV;
407 	return 0;
408 }
409 
410 static int skeleton_s_std(struct file *file, void *priv, v4l2_std_id std)
411 {
412 	struct skeleton *skel = video_drvdata(file);
413 
414 	/* S_STD is not supported on the HDMI input */
415 	if (skel->input)
416 		return -ENODATA;
417 
418 	/*
419 	 * No change, so just return. Some applications call S_STD again after
420 	 * the buffers for streaming have been set up, so we have to allow for
421 	 * this behavior.
422 	 */
423 	if (std == skel->std)
424 		return 0;
425 
426 	/*
427 	 * Changing the standard implies a format change, which is not allowed
428 	 * while buffers for use with streaming have already been allocated.
429 	 */
430 	if (vb2_is_busy(&skel->queue))
431 		return -EBUSY;
432 
433 	/* TODO: handle changing std */
434 
435 	skel->std = std;
436 
437 	/* Update the internal format */
438 	skeleton_fill_pix_format(skel, &skel->format);
439 	return 0;
440 }
441 
442 static int skeleton_g_std(struct file *file, void *priv, v4l2_std_id *std)
443 {
444 	struct skeleton *skel = video_drvdata(file);
445 
446 	/* G_STD is not supported on the HDMI input */
447 	if (skel->input)
448 		return -ENODATA;
449 
450 	*std = skel->std;
451 	return 0;
452 }
453 
454 /*
455  * Query the current standard as seen by the hardware. This function shall
456  * never actually change the standard, it just detects and reports.
457  * The framework will initially set *std to tvnorms (i.e. the set of
458  * supported standards by this input), and this function should just AND
459  * this value. If there is no signal, then *std should be set to 0.
460  */
461 static int skeleton_querystd(struct file *file, void *priv, v4l2_std_id *std)
462 {
463 	struct skeleton *skel = video_drvdata(file);
464 
465 	/* QUERY_STD is not supported on the HDMI input */
466 	if (skel->input)
467 		return -ENODATA;
468 
469 #ifdef TODO
470 	/*
471 	 * Query currently seen standard. Initial value of *std is
472 	 * V4L2_STD_ALL. This function should look something like this:
473 	 */
474 	get_signal_info();
475 	if (no_signal) {
476 		*std = 0;
477 		return 0;
478 	}
479 	/* Use signal information to reduce the number of possible standards */
480 	if (signal_has_525_lines)
481 		*std &= V4L2_STD_525_60;
482 	else
483 		*std &= V4L2_STD_625_50;
484 #endif
485 	return 0;
486 }
487 
488 static int skeleton_s_dv_timings(struct file *file, void *_fh,
489 				 struct v4l2_dv_timings *timings)
490 {
491 	struct skeleton *skel = video_drvdata(file);
492 
493 	/* S_DV_TIMINGS is not supported on the S-Video input */
494 	if (skel->input == 0)
495 		return -ENODATA;
496 
497 	/* Quick sanity check */
498 	if (!v4l2_valid_dv_timings(timings, &skel_timings_cap, NULL, NULL))
499 		return -EINVAL;
500 
501 	/* Check if the timings are part of the CEA-861 timings. */
502 	if (!v4l2_find_dv_timings_cap(timings, &skel_timings_cap,
503 				      0, NULL, NULL))
504 		return -EINVAL;
505 
506 	/* Return 0 if the new timings are the same as the current timings. */
507 	if (v4l2_match_dv_timings(timings, &skel->timings, 0, false))
508 		return 0;
509 
510 	/*
511 	 * Changing the timings implies a format change, which is not allowed
512 	 * while buffers for use with streaming have already been allocated.
513 	 */
514 	if (vb2_is_busy(&skel->queue))
515 		return -EBUSY;
516 
517 	/* TODO: Configure new timings */
518 
519 	/* Save timings */
520 	skel->timings = *timings;
521 
522 	/* Update the internal format */
523 	skeleton_fill_pix_format(skel, &skel->format);
524 	return 0;
525 }
526 
527 static int skeleton_g_dv_timings(struct file *file, void *_fh,
528 				 struct v4l2_dv_timings *timings)
529 {
530 	struct skeleton *skel = video_drvdata(file);
531 
532 	/* G_DV_TIMINGS is not supported on the S-Video input */
533 	if (skel->input == 0)
534 		return -ENODATA;
535 
536 	*timings = skel->timings;
537 	return 0;
538 }
539 
540 static int skeleton_enum_dv_timings(struct file *file, void *_fh,
541 				    struct v4l2_enum_dv_timings *timings)
542 {
543 	struct skeleton *skel = video_drvdata(file);
544 
545 	/* ENUM_DV_TIMINGS is not supported on the S-Video input */
546 	if (skel->input == 0)
547 		return -ENODATA;
548 
549 	return v4l2_enum_dv_timings_cap(timings, &skel_timings_cap,
550 					NULL, NULL);
551 }
552 
553 /*
554  * Query the current timings as seen by the hardware. This function shall
555  * never actually change the timings, it just detects and reports.
556  * If no signal is detected, then return -ENOLINK. If the hardware cannot
557  * lock to the signal, then return -ENOLCK. If the signal is out of range
558  * of the capabilities of the system (e.g., it is possible that the receiver
559  * can lock but that the DMA engine it is connected to cannot handle
560  * pixelclocks above a certain frequency), then -ERANGE is returned.
561  */
562 static int skeleton_query_dv_timings(struct file *file, void *_fh,
563 				     struct v4l2_dv_timings *timings)
564 {
565 	struct skeleton *skel = video_drvdata(file);
566 
567 	/* QUERY_DV_TIMINGS is not supported on the S-Video input */
568 	if (skel->input == 0)
569 		return -ENODATA;
570 
571 #ifdef TODO
572 	/*
573 	 * Query currently seen timings. This function should look
574 	 * something like this:
575 	 */
576 	detect_timings();
577 	if (no_signal)
578 		return -ENOLINK;
579 	if (cannot_lock_to_signal)
580 		return -ENOLCK;
581 	if (signal_out_of_range_of_capabilities)
582 		return -ERANGE;
583 
584 	/* Useful for debugging */
585 	v4l2_print_dv_timings(skel->v4l2_dev.name, "query_dv_timings:",
586 			timings, true);
587 #endif
588 	return 0;
589 }
590 
591 static int skeleton_dv_timings_cap(struct file *file, void *fh,
592 				   struct v4l2_dv_timings_cap *cap)
593 {
594 	struct skeleton *skel = video_drvdata(file);
595 
596 	/* DV_TIMINGS_CAP is not supported on the S-Video input */
597 	if (skel->input == 0)
598 		return -ENODATA;
599 	*cap = skel_timings_cap;
600 	return 0;
601 }
602 
603 static int skeleton_enum_input(struct file *file, void *priv,
604 			       struct v4l2_input *i)
605 {
606 	if (i->index > 1)
607 		return -EINVAL;
608 
609 	i->type = V4L2_INPUT_TYPE_CAMERA;
610 	if (i->index == 0) {
611 		i->std = SKEL_TVNORMS;
612 		strlcpy(i->name, "S-Video", sizeof(i->name));
613 		i->capabilities = V4L2_IN_CAP_STD;
614 	} else {
615 		i->std = 0;
616 		strlcpy(i->name, "HDMI", sizeof(i->name));
617 		i->capabilities = V4L2_IN_CAP_DV_TIMINGS;
618 	}
619 	return 0;
620 }
621 
622 static int skeleton_s_input(struct file *file, void *priv, unsigned int i)
623 {
624 	struct skeleton *skel = video_drvdata(file);
625 
626 	if (i > 1)
627 		return -EINVAL;
628 
629 	/*
630 	 * Changing the input implies a format change, which is not allowed
631 	 * while buffers for use with streaming have already been allocated.
632 	 */
633 	if (vb2_is_busy(&skel->queue))
634 		return -EBUSY;
635 
636 	skel->input = i;
637 	/*
638 	 * Update tvnorms. The tvnorms value is used by the core to implement
639 	 * VIDIOC_ENUMSTD so it has to be correct. If tvnorms == 0, then
640 	 * ENUMSTD will return -ENODATA.
641 	 */
642 	skel->vdev.tvnorms = i ? 0 : SKEL_TVNORMS;
643 
644 	/* Update the internal format */
645 	skeleton_fill_pix_format(skel, &skel->format);
646 	return 0;
647 }
648 
649 static int skeleton_g_input(struct file *file, void *priv, unsigned int *i)
650 {
651 	struct skeleton *skel = video_drvdata(file);
652 
653 	*i = skel->input;
654 	return 0;
655 }
656 
657 /* The control handler. */
658 static int skeleton_s_ctrl(struct v4l2_ctrl *ctrl)
659 {
660 	/*struct skeleton *skel =
661 		container_of(ctrl->handler, struct skeleton, ctrl_handler);*/
662 
663 	switch (ctrl->id) {
664 	case V4L2_CID_BRIGHTNESS:
665 		/* TODO: set brightness to ctrl->val */
666 		break;
667 	case V4L2_CID_CONTRAST:
668 		/* TODO: set contrast to ctrl->val */
669 		break;
670 	case V4L2_CID_SATURATION:
671 		/* TODO: set saturation to ctrl->val */
672 		break;
673 	case V4L2_CID_HUE:
674 		/* TODO: set hue to ctrl->val */
675 		break;
676 	default:
677 		return -EINVAL;
678 	}
679 	return 0;
680 }
681 
682 /* ------------------------------------------------------------------
683 	File operations for the device
684    ------------------------------------------------------------------*/
685 
686 static const struct v4l2_ctrl_ops skel_ctrl_ops = {
687 	.s_ctrl = skeleton_s_ctrl,
688 };
689 
690 /*
691  * The set of all supported ioctls. Note that all the streaming ioctls
692  * use the vb2 helper functions that take care of all the locking and
693  * that also do ownership tracking (i.e. only the filehandle that requested
694  * the buffers can call the streaming ioctls, all other filehandles will
695  * receive -EBUSY if they attempt to call the same streaming ioctls).
696  *
697  * The last three ioctls also use standard helper functions: these implement
698  * standard behavior for drivers with controls.
699  */
700 static const struct v4l2_ioctl_ops skel_ioctl_ops = {
701 	.vidioc_querycap = skeleton_querycap,
702 	.vidioc_try_fmt_vid_cap = skeleton_try_fmt_vid_cap,
703 	.vidioc_s_fmt_vid_cap = skeleton_s_fmt_vid_cap,
704 	.vidioc_g_fmt_vid_cap = skeleton_g_fmt_vid_cap,
705 	.vidioc_enum_fmt_vid_cap = skeleton_enum_fmt_vid_cap,
706 
707 	.vidioc_g_std = skeleton_g_std,
708 	.vidioc_s_std = skeleton_s_std,
709 	.vidioc_querystd = skeleton_querystd,
710 
711 	.vidioc_s_dv_timings = skeleton_s_dv_timings,
712 	.vidioc_g_dv_timings = skeleton_g_dv_timings,
713 	.vidioc_enum_dv_timings = skeleton_enum_dv_timings,
714 	.vidioc_query_dv_timings = skeleton_query_dv_timings,
715 	.vidioc_dv_timings_cap = skeleton_dv_timings_cap,
716 
717 	.vidioc_enum_input = skeleton_enum_input,
718 	.vidioc_g_input = skeleton_g_input,
719 	.vidioc_s_input = skeleton_s_input,
720 
721 	.vidioc_reqbufs = vb2_ioctl_reqbufs,
722 	.vidioc_create_bufs = vb2_ioctl_create_bufs,
723 	.vidioc_querybuf = vb2_ioctl_querybuf,
724 	.vidioc_qbuf = vb2_ioctl_qbuf,
725 	.vidioc_dqbuf = vb2_ioctl_dqbuf,
726 	.vidioc_expbuf = vb2_ioctl_expbuf,
727 	.vidioc_streamon = vb2_ioctl_streamon,
728 	.vidioc_streamoff = vb2_ioctl_streamoff,
729 
730 	.vidioc_log_status = v4l2_ctrl_log_status,
731 	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
732 	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
733 };
734 
735 /*
736  * The set of file operations. Note that all these ops are standard core
737  * helper functions.
738  */
739 static const struct v4l2_file_operations skel_fops = {
740 	.owner = THIS_MODULE,
741 	.open = v4l2_fh_open,
742 	.release = vb2_fop_release,
743 	.unlocked_ioctl = video_ioctl2,
744 	.read = vb2_fop_read,
745 	.mmap = vb2_fop_mmap,
746 	.poll = vb2_fop_poll,
747 };
748 
749 /*
750  * The initial setup of this device instance. Note that the initial state of
751  * the driver should be complete. So the initial format, standard, timings
752  * and video input should all be initialized to some reasonable value.
753  */
754 static int skeleton_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
755 {
756 	/* The initial timings are chosen to be 720p60. */
757 	static const struct v4l2_dv_timings timings_def =
758 		V4L2_DV_BT_CEA_1280X720P60;
759 	struct skeleton *skel;
760 	struct video_device *vdev;
761 	struct v4l2_ctrl_handler *hdl;
762 	struct vb2_queue *q;
763 	int ret;
764 
765 	/* Enable PCI */
766 	ret = pci_enable_device(pdev);
767 	if (ret)
768 		return ret;
769 	ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
770 	if (ret) {
771 		dev_err(&pdev->dev, "no suitable DMA available.\n");
772 		goto disable_pci;
773 	}
774 
775 	/* Allocate a new instance */
776 	skel = devm_kzalloc(&pdev->dev, sizeof(struct skeleton), GFP_KERNEL);
777 	if (!skel) {
778 		ret = -ENOMEM;
779 		goto disable_pci;
780 	}
781 
782 	/* Allocate the interrupt */
783 	ret = devm_request_irq(&pdev->dev, pdev->irq,
784 			       skeleton_irq, 0, KBUILD_MODNAME, skel);
785 	if (ret) {
786 		dev_err(&pdev->dev, "request_irq failed\n");
787 		goto disable_pci;
788 	}
789 	skel->pdev = pdev;
790 
791 	/* Fill in the initial format-related settings */
792 	skel->timings = timings_def;
793 	skel->std = V4L2_STD_625_50;
794 	skeleton_fill_pix_format(skel, &skel->format);
795 
796 	/* Initialize the top-level structure */
797 	ret = v4l2_device_register(&pdev->dev, &skel->v4l2_dev);
798 	if (ret)
799 		goto disable_pci;
800 
801 	mutex_init(&skel->lock);
802 
803 	/* Add the controls */
804 	hdl = &skel->ctrl_handler;
805 	v4l2_ctrl_handler_init(hdl, 4);
806 	v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
807 			  V4L2_CID_BRIGHTNESS, 0, 255, 1, 127);
808 	v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
809 			  V4L2_CID_CONTRAST, 0, 255, 1, 16);
810 	v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
811 			  V4L2_CID_SATURATION, 0, 255, 1, 127);
812 	v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
813 			  V4L2_CID_HUE, -128, 127, 1, 0);
814 	if (hdl->error) {
815 		ret = hdl->error;
816 		goto free_hdl;
817 	}
818 	skel->v4l2_dev.ctrl_handler = hdl;
819 
820 	/* Initialize the vb2 queue */
821 	q = &skel->queue;
822 	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
823 	q->io_modes = VB2_MMAP | VB2_DMABUF | VB2_READ;
824 	q->dev = &pdev->dev;
825 	q->drv_priv = skel;
826 	q->buf_struct_size = sizeof(struct skel_buffer);
827 	q->ops = &skel_qops;
828 	q->mem_ops = &vb2_dma_contig_memops;
829 	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
830 	/*
831 	 * Assume that this DMA engine needs to have at least two buffers
832 	 * available before it can be started. The start_streaming() op
833 	 * won't be called until at least this many buffers are queued up.
834 	 */
835 	q->min_buffers_needed = 2;
836 	/*
837 	 * The serialization lock for the streaming ioctls. This is the same
838 	 * as the main serialization lock, but if some of the non-streaming
839 	 * ioctls could take a long time to execute, then you might want to
840 	 * have a different lock here to prevent VIDIOC_DQBUF from being
841 	 * blocked while waiting for another action to finish. This is
842 	 * generally not needed for PCI devices, but USB devices usually do
843 	 * want a separate lock here.
844 	 */
845 	q->lock = &skel->lock;
846 	/*
847 	 * Since this driver can only do 32-bit DMA we must make sure that
848 	 * the vb2 core will allocate the buffers in 32-bit DMA memory.
849 	 */
850 	q->gfp_flags = GFP_DMA32;
851 	ret = vb2_queue_init(q);
852 	if (ret)
853 		goto free_hdl;
854 
855 	INIT_LIST_HEAD(&skel->buf_list);
856 	spin_lock_init(&skel->qlock);
857 
858 	/* Initialize the video_device structure */
859 	vdev = &skel->vdev;
860 	strlcpy(vdev->name, KBUILD_MODNAME, sizeof(vdev->name));
861 	/*
862 	 * There is nothing to clean up, so release is set to an empty release
863 	 * function. The release callback must be non-NULL.
864 	 */
865 	vdev->release = video_device_release_empty;
866 	vdev->fops = &skel_fops,
867 	vdev->ioctl_ops = &skel_ioctl_ops,
868 	vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE |
869 			    V4L2_CAP_STREAMING;
870 	/*
871 	 * The main serialization lock. All ioctls are serialized by this
872 	 * lock. Exception: if q->lock is set, then the streaming ioctls
873 	 * are serialized by that separate lock.
874 	 */
875 	vdev->lock = &skel->lock;
876 	vdev->queue = q;
877 	vdev->v4l2_dev = &skel->v4l2_dev;
878 	/* Supported SDTV standards, if any */
879 	vdev->tvnorms = SKEL_TVNORMS;
880 	video_set_drvdata(vdev, skel);
881 
882 	ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
883 	if (ret)
884 		goto free_hdl;
885 
886 	dev_info(&pdev->dev, "V4L2 PCI Skeleton Driver loaded\n");
887 	return 0;
888 
889 free_hdl:
890 	v4l2_ctrl_handler_free(&skel->ctrl_handler);
891 	v4l2_device_unregister(&skel->v4l2_dev);
892 disable_pci:
893 	pci_disable_device(pdev);
894 	return ret;
895 }
896 
897 static void skeleton_remove(struct pci_dev *pdev)
898 {
899 	struct v4l2_device *v4l2_dev = pci_get_drvdata(pdev);
900 	struct skeleton *skel = container_of(v4l2_dev, struct skeleton, v4l2_dev);
901 
902 	video_unregister_device(&skel->vdev);
903 	v4l2_ctrl_handler_free(&skel->ctrl_handler);
904 	v4l2_device_unregister(&skel->v4l2_dev);
905 	pci_disable_device(skel->pdev);
906 }
907 
908 static struct pci_driver skeleton_driver = {
909 	.name = KBUILD_MODNAME,
910 	.probe = skeleton_probe,
911 	.remove = skeleton_remove,
912 	.id_table = skeleton_pci_tbl,
913 };
914 
915 module_pci_driver(skeleton_driver);
916