aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/media/video/mx1_camera.c
blob: 2ba14fb5b0311f0f86a42b2148b3fe30e0e7805e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
/*
 * V4L2 Driver for i.MXL/i.MXL camera (CSI) host
 *
 * Copyright (C) 2008, Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
 * Copyright (C) 2009, Darius Augulis <augulis.darius@gmail.com>
 *
 * Based on PXA SoC camera driver
 * Copyright (C) 2006, Sascha Hauer, Pengutronix
 * Copyright (C) 2008, Guennadi Liakhovetski <kernel@pengutronix.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/version.h>
#include <linux/videodev2.h>

#include <media/soc_camera.h>
#include <media/v4l2-common.h>
#include <media/v4l2-dev.h>
#include <media/videobuf-dma-contig.h>
#include <media/soc_mediabus.h>

#include <asm/dma.h>
#include <asm/fiq.h>
#include <mach/dma-mx1-mx2.h>
#include <mach/hardware.h>
#include <mach/mx1_camera.h>

/*
 * CSI registers
 */
#define DMA_CCR(x)	(0x8c + ((x) << 6))	/* Control Registers */
#define DMA_DIMR	0x08			/* Interrupt mask Register */
#define CSICR1		0x00			/* CSI Control Register 1 */
#define CSISR		0x08			/* CSI Status Register */
#define CSIRXR		0x10			/* CSI RxFIFO Register */

#define CSICR1_RXFF_LEVEL(x)	(((x) & 0x3) << 19)
#define CSICR1_SOF_POL		(1 << 17)
#define CSICR1_SOF_INTEN	(1 << 16)
#define CSICR1_MCLKDIV(x)	(((x) & 0xf) << 12)
#define CSICR1_MCLKEN		(1 << 9)
#define CSICR1_FCC		(1 << 8)
#define CSICR1_BIG_ENDIAN	(1 << 7)
#define CSICR1_CLR_RXFIFO	(1 << 5)
#define CSICR1_GCLK_MODE	(1 << 4)
#define CSICR1_DATA_POL		(1 << 2)
#define CSICR1_REDGE		(1 << 1)
#define CSICR1_EN		(1 << 0)

#define CSISR_SFF_OR_INT	(1 << 25)
#define CSISR_RFF_OR_INT	(1 << 24)
#define CSISR_STATFF_INT	(1 << 21)
#define CSISR_RXFF_INT		(1 << 18)
#define CSISR_SOF_INT		(1 << 16)
#define CSISR_DRDY		(1 << 0)

#define VERSION_CODE KERNEL_VERSION(0, 0, 1)
#define DRIVER_NAME "mx1-camera"

#define CSI_IRQ_MASK	(CSISR_SFF_OR_INT | CSISR_RFF_OR_INT | \
			CSISR_STATFF_INT | CSISR_RXFF_INT | CSISR_SOF_INT)

#define CSI_BUS_FLAGS	(SOCAM_MASTER | SOCAM_HSYNC_ACTIVE_HIGH | \
			SOCAM_VSYNC_ACTIVE_HIGH | SOCAM_VSYNC_ACTIVE_LOW | \
			SOCAM_PCLK_SAMPLE_RISING | SOCAM_PCLK_SAMPLE_FALLING | \
			SOCAM_DATA_ACTIVE_HIGH | SOCAM_DATA_ACTIVE_LOW | \
			SOCAM_DATAWIDTH_8)

#define MAX_VIDEO_MEM 16	/* Video memory limit in megabytes */

/*
 * Structures
 */

/* buffer for one video frame */
struct mx1_buffer {
	/* common v4l buffer stuff -- must be first */
	struct videobuf_buffer		vb;
	enum v4l2_mbus_pixelcode	code;
	int				inwork;
};

/*
 * i.MX1/i.MXL is only supposed to handle one camera on its Camera Sensor
 * Interface. If anyone ever builds hardware to enable more than
 * one camera, they will have to modify this driver too
 */
struct mx1_camera_dev {
	struct soc_camera_host		soc_host;
	struct soc_camera_device	*icd;
	struct mx1_camera_pdata		*pdata;
	struct mx1_buffer		*active;
	struct resource			*res;
	struct clk			*clk;
	struct list_head		capture;

	void __iomem			*base;
	int				dma_chan;
	unsigned int			irq;
	unsigned long			mclk;

	spinlock_t			lock;
};

/*
 *  Videobuf operations
 */
static int mx1_videobuf_setup(struct videobuf_queue *vq, unsigned int *count,
			      unsigned int *size)
{
	struct soc_camera_device *icd = vq->priv_data;
	int bytes_per_line = soc_mbus_bytes_per_line(icd->user_width,
						icd->current_fmt->host_fmt);

	if (bytes_per_line < 0)
		return bytes_per_line;

	*size = bytes_per_line * icd->user_height;

	if (!*count)
		*count = 32;

	while (*size * *count > MAX_VIDEO_MEM * 1024 * 1024)
		(*count)--;

	dev_dbg(icd->dev.parent, "count=%d, size=%d\n", *count, *size);

	return 0;
}

static void free_buffer(struct videobuf_queue *vq, struct mx1_buffer *buf)
{
	struct soc_camera_device *icd = vq->priv_data;
	struct videobuf_buffer *vb = &buf->vb;

	BUG_ON(in_interrupt());

	dev_dbg(icd->dev.parent, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
		vb, vb->baddr, vb->bsize);

	/*
	 * This waits until this buffer is out of danger, i.e., until it is no
	 * longer in STATE_QUEUED or STATE_ACTIVE
	 */
	videobuf_waiton(vb, 0, 0);
	videobuf_dma_contig_free(vq, vb);

	vb->state = VIDEOBUF_NEEDS_INIT;
}

static int mx1_videobuf_prepare(struct videobuf_queue *vq,
		struct videobuf_buffer *vb, enum v4l2_field field)
{
	struct soc_camera_device *icd = vq->priv_data;
	struct mx1_buffer *buf = container_of(vb, struct mx1_buffer, vb);
	int ret;
	int bytes_per_line = soc_mbus_bytes_per_line(icd->user_width,
						icd->current_fmt->host_fmt);

	if (bytes_per_line < 0)
		return bytes_per_line;

	dev_dbg(icd->dev.parent, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
		vb, vb->baddr, vb->bsize);

	/* Added list head initialization on alloc */
	WARN_ON(!list_empty(&vb->queue));

	BUG_ON(NULL == icd->current_fmt);

	/*
	 * I think, in buf_prepare you only have to protect global data,
	 * the actual buffer is yours
	 */
	buf->inwork = 1;

	if (buf->code	!= icd->current_fmt->code ||
	    vb->width	!= icd->user_width ||
	    vb->height	!= icd->user_height ||
	    vb->field	!= field) {
		buf->code	= icd->current_fmt->code;
		vb->width	= icd->user_width;
		vb->height	= icd->user_height;
		vb->field	= field;
		vb->state	= VIDEOBUF_NEEDS_INIT;
	}

	vb->size = bytes_per_line * vb->height;
	if (0 != vb->baddr && vb->bsize < vb->size) {
		ret = -EINVAL;
		goto out;
	}

	if (vb->state == VIDEOBUF_NEEDS_INIT) {
		ret = videobuf_iolock(vq, vb, NULL);
		if (ret)
			goto fail;

		vb->state = VIDEOBUF_PREPARED;
	}

	buf->inwork = 0;

	return 0;

fail:
	free_buffer(vq, buf);
out:
	buf->inwork = 0;
	return ret;
}

static int mx1_camera_setup_dma(struct mx1_camera_dev *pcdev)
{
	struct videobuf_buffer *vbuf = &pcdev->active->vb;
	struct device *dev = pcdev->icd->dev.parent;
	int ret;

	if (unlikely(!pcdev->active)) {
		dev_err(dev, "DMA End IRQ with no active buffer\n");
		return -EFAULT;
	}

	/* setup sg list for future DMA */
	ret = imx_dma_setup_single(pcdev->dma_chan,
		videobuf_to_dma_contig(vbuf),
		vbuf->size, pcdev->res->start +
		CSIRXR, DMA_MODE_READ);
	if (unlikely(ret))
		dev_err(dev, "Failed to setup DMA sg list\n");

	return ret;
}

/* Called under spinlock_irqsave(&pcdev->lock, ...) */
static void mx1_videobuf_queue(struct videobuf_queue *vq,
						struct videobuf_buffer *vb)
{
	struct soc_camera_device *icd = vq->priv_data;
	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
	struct mx1_camera_dev *pcdev = ici->priv;
	struct mx1_buffer *buf = container_of(vb, struct mx1_buffer, vb);

	dev_dbg(icd->dev.parent, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
		vb, vb->baddr, vb->bsize);

	list_add_tail(&vb->queue, &pcdev->capture);

	vb->state = VIDEOBUF_ACTIVE;

	if (!pcdev->active) {
		pcdev->active = buf;

		/* setup sg list for future DMA */
		if (!mx1_camera_setup_dma(pcdev)) {
			unsigned int temp;
			/* enable SOF irq */
			temp = __raw_readl(pcdev->base + CSICR1) |
							CSICR1_SOF_INTEN;
			__raw_writel(temp, pcdev->base + CSICR1);
		}
	}
}

static void mx1_videobuf_release(struct videobuf_queue *vq,
				 struct videobuf_buffer *vb)
{
	struct mx1_buffer *buf = container_of(vb, struct mx1_buffer, vb);
#ifdef DEBUG
	struct soc_camera_device *icd = vq->priv_data;
	struct device *dev = icd->dev.parent;

	dev_dbg(dev, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
		vb, vb->baddr, vb->bsize);

	switch (vb->state) {
	case VIDEOBUF_ACTIVE:
		dev_dbg(dev, "%s (active)\n", __func__);
		break;
	case VIDEOBUF_QUEUED:
		dev_dbg(dev, "%s (queued)\n", __func__);
		break;
	case VIDEOBUF_PREPARED:
		dev_dbg(dev, "%s (prepared)\n", __func__);
		break;
	default:
		dev_dbg(dev, "%s (unknown)\n", __func__);
		break;
	}
#endif

	free_buffer(vq, buf);
}

static void mx1_camera_wakeup(struct mx1_camera_dev *pcdev,
			      struct videobuf_buffer *vb,
			      struct mx1_buffer *buf)
{
	/* _init is used to debug races, see comment in mx1_camera_reqbufs() */
	list_del_init(&vb->queue);
	vb->state = VIDEOBUF_DONE;
	do_gettimeofday(&vb->ts);
	vb->field_count++;
	wake_up(&vb->done);

	if (list_empty(&pcdev->capture)) {
		pcdev->active = NULL;
		return;
	}

	pcdev->active = list_entry(pcdev->capture.next,
				   struct mx1_buffer, vb.queue);

	/* setup sg list for future DMA */
	if (likely(!mx1_camera_setup_dma(pcdev))) {
		unsigned int temp;

		/* enable SOF irq */
		temp = __raw_readl(pcdev->base + CSICR1) | CSICR1_SOF_INTEN;
		__raw_writel(temp, pcdev->base + CSICR1);
	}
}

static void mx1_camera_dma_irq(int channel, void *data)
{
	struct mx1_camera_dev *pcdev = data;
	struct device *dev = pcdev->icd->dev.parent;
	struct mx1_buffer *buf;
	struct videobuf_buffer *vb;
	unsigned long flags;

	spin_lock_irqsave(&pcdev->lock, flags);

	imx_dma_disable(channel);

	if (unlikely(!pcdev->active)) {
		dev_err(dev, "DMA End IRQ with no active buffer\n");
		goto out;
	}

	vb = &pcdev->active->vb;
	buf = container_of(vb, struct mx1_buffer, vb);
	WARN_ON(buf->inwork || list_empty(&vb->queue));
	dev_dbg(dev, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
		vb, vb->baddr, vb->bsize);

	mx1_camera_wakeup(pcdev, vb, buf);
out:
	spin_unlock_irqrestore(&pcdev->lock, flags);
}

static struct videobuf_queue_ops mx1_videobuf_ops = {
	.buf_setup	= mx1_videobuf_setup,
	.buf_prepare	= mx1_videobuf_prepare,
	.buf_queue	= mx1_videobuf_queue,
	.buf_release	= mx1_videobuf_release,
};

static void mx1_camera_init_videobuf(struct videobuf_queue *q,
				     struct soc_camera_device *icd)
{
	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
	struct mx1_camera_dev *pcdev = ici->priv;

	videobuf_queue_dma_contig_init(q, &mx1_videobuf_ops, icd->dev.parent,
					&pcdev->lock,
					V4L2_BUF_TYPE_VIDEO_CAPTURE,
					V4L2_FIELD_NONE,
					sizeof(struct mx1_buffer), icd);
}

static int mclk_get_divisor(struct mx1_camera_dev *pcdev)
{
	unsigned int mclk = pcdev->mclk;
	unsigned long div;
	unsigned long lcdclk;

	lcdclk = clk_get_rate(pcdev->clk);

	/*
	 * We verify platform_mclk_10khz != 0, so if anyone breaks it, here
	 * they get a nice Oops
	 */
	div = (lcdclk + 2 * mclk - 1) / (2 * mclk) - 1;

	dev_dbg(pcdev->icd->dev.parent,
		"System clock %lukHz, target freq %dkHz, divisor %lu\n",
		lcdclk / 1000, mclk / 1000, div);

	return div;
}

static void mx1_camera_activate(struct mx1_camera_dev *pcdev)
{
	unsigned int csicr1 = CSICR1_EN;

	dev_dbg(pcdev->icd->dev.parent, "Activate device\n");

	clk_enable(pcdev->clk);

	/* enable CSI before doing anything else */
	__raw_writel(csicr1, pcdev->base + CSICR1);

	csicr1 |= CSICR1_MCLKEN | CSICR1_FCC | CSICR1_GCLK_MODE;
	csicr1 |= CSICR1_MCLKDIV(mclk_get_divisor(pcdev));
	csicr1 |= CSICR1_RXFF_LEVEL(2); /* 16 words */

	__raw_writel(csicr1, pcdev->base + CSICR1);
}

static void mx1_camera_deactivate(struct mx1_camera_dev *pcdev)
{
	dev_dbg(pcdev->icd->dev.parent, "Deactivate device\n");

	/* Disable all CSI interface */
	__raw_writel(0x00, pcdev->base + CSICR1);

	clk_disable(pcdev->clk);
}

/*
 * The following two functions absolutely depend on the fact, that
 * there can be only one camera on i.MX1/i.MXL camera sensor interface
 */
static int mx1_camera_add_device(struct soc_camera_device *icd)
{
	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
	struct mx1_camera_dev *pcdev = ici->priv;
	int ret;

	if (pcdev->icd) {
		ret = -EBUSY;
		goto ebusy;
	}

	dev_info(icd->dev.parent, "MX1 Camera driver attached to camera %d\n",
		 icd->devnum);

	mx1_camera_activate(pcdev);

	pcdev->icd = icd;

ebusy:
	return ret;
}

static void mx1_camera_remove_device(struct soc_camera_device *icd)
{
	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
	struct mx1_camera_dev *pcdev = ici->priv;
	unsigned int csicr1;

	BUG_ON(icd != pcdev->icd);

	/* disable interrupts */
	csicr1 = __raw_readl(pcdev->base + CSICR1) & ~CSI_IRQ_MASK;
	__raw_writel(csicr1, pcdev->base + CSICR1);

	/* Stop DMA engine */
	imx_dma_disable(pcdev->dma_chan);

	dev_info(icd->dev.parent, "MX1 Camera driver detached from camera %d\n",
		 icd->devnum);

	mx1_camera_deactivate(pcdev);

	pcdev->icd = NULL;
}

static int mx1_camera_set_crop(struct soc_camera_device *icd,
			       struct v4l2_crop *a)
{
	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);

	return v4l2_subdev_call(sd, video, s_crop, a);
}

static int mx1_camera_set_bus_param(struct soc_camera_device *icd, __u32 pixfmt)
{
	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
	struct mx1_camera_dev *pcdev = ici->priv;
	unsigned long camera_flags, common_flags;
	unsigned int csicr1;
	int ret;

	camera_flags = icd->ops->query_bus_param(icd);

	/* MX1 supports only 8bit buswidth */
	common_flags = soc_camera_bus_param_compatible(camera_flags,
						       CSI_BUS_FLAGS);
	if (!common_flags)
		return -EINVAL;

	/* Make choises, based on platform choice */
	if ((common_flags & SOCAM_VSYNC_ACTIVE_HIGH) &&
		(common_flags & SOCAM_VSYNC_ACTIVE_LOW)) {
			if (!pcdev->pdata ||
			     pcdev->pdata->flags & MX1_CAMERA_VSYNC_HIGH)
				common_flags &= ~SOCAM_VSYNC_ACTIVE_LOW;
			else
				common_flags &= ~SOCAM_VSYNC_ACTIVE_HIGH;
	}

	if ((common_flags & SOCAM_PCLK_SAMPLE_RISING) &&
		(common_flags & SOCAM_PCLK_SAMPLE_FALLING)) {
			if (!pcdev->pdata ||
			     pcdev->pdata->flags & MX1_CAMERA_PCLK_RISING)
				common_flags &= ~SOCAM_PCLK_SAMPLE_FALLING;
			else
				common_flags &= ~SOCAM_PCLK_SAMPLE_RISING;
	}

	if ((common_flags & SOCAM_DATA_ACTIVE_HIGH) &&
		(common_flags & SOCAM_DATA_ACTIVE_LOW)) {
			if (!pcdev->pdata ||
			     pcdev->pdata->flags & MX1_CAMERA_DATA_HIGH)
				common_flags &= ~SOCAM_DATA_ACTIVE_LOW;
			else
				common_flags &= ~SOCAM_DATA_ACTIVE_HIGH;
	}

	ret = icd->ops->set_bus_param(icd, common_flags);
	if (ret < 0)
		return ret;

	csicr1 = __raw_readl(pcdev->base + CSICR1);

	if (common_flags & SOCAM_PCLK_SAMPLE_RISING)
		csicr1 |= CSICR1_REDGE;
	if (common_flags & SOCAM_VSYNC_ACTIVE_HIGH)
		csicr1 |= CSICR1_SOF_POL;
	if (common_flags & SOCAM_DATA_ACTIVE_LOW)
		csicr1 |= CSICR1_DATA_POL;

	__raw_writel(csicr1, pcdev->base + CSICR1);

	return 0;
}

static int mx1_camera_set_fmt(struct soc_camera_device *icd,
			      struct v4l2_format *f)
{
	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
	const struct soc_camera_format_xlate *xlate;
	struct v4l2_pix_format *pix = &f->fmt.pix;
	struct v4l2_mbus_framefmt mf;
	int ret, buswidth;

	xlate = soc_camera_xlate_by_fourcc(icd, pix->pixelformat);
	if (!xlate) {
		dev_warn(icd->dev.parent, "Format %x not found\n",
			 pix->pixelformat);
		return -EINVAL;
	}

	buswidth = xlate->host_fmt->bits_per_sample;
	if (buswidth > 8) {
		dev_warn(icd->dev.parent,
			 "bits-per-sample %d for format %x unsupported\n",
			 buswidth, pix->pixelformat);
		return -EINVAL;
	}

	mf.width	= pix->width;
	mf.height	= pix->height;
	mf.field	= pix->field;
	mf.colorspace	= pix->colorspace;
	mf.code		= xlate->code;

	ret = v4l2_subdev_call(sd, video, s_mbus_fmt, &mf);
	if (ret < 0)
		return ret;

	if (mf.code != xlate->code)
		return -EINVAL;

	pix->width		= mf.width;
	pix->height		= mf.height;
	pix->field		= mf.field;
	pix->colorspace		= mf.colorspace;
	icd->current_fmt	= xlate;

	return ret;
}

static int mx1_camera_try_fmt(struct soc_camera_device *icd,
			      struct v4l2_format *f)
{
	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
	const struct soc_camera_format_xlate *xlate;
	struct v4l2_pix_format *pix = &f->fmt.pix;
	struct v4l2_mbus_framefmt mf;
	int ret;
	/* TODO: limit to mx1 hardware capabilities */

	xlate = soc_camera_xlate_by_fourcc(icd, pix->pixelformat);
	if (!xlate) {
		dev_warn(icd->dev.parent, "Format %x not found\n",
			 pix->pixelformat);
		return -EINVAL;
	}

	mf.width	= pix->width;
	mf.height	= pix->height;
	mf.field	= pix->field;
	mf.colorspace	= pix->colorspace;
	mf.code		= xlate->code;

	/* limit to sensor capabilities */
	ret = v4l2_subdev_call(sd, video, try_mbus_fmt, &mf);
	if (ret < 0)
		return ret;

	pix->width	= mf.width;
	pix->height	= mf.height;
	pix->field	= mf.field;
	pix->colorspace	= mf.colorspace;

	return 0;
}

static int mx1_camera_reqbufs(struct soc_camera_file *icf,
			      struct v4l2_requestbuffers *p)
{
	int i;

	/*
	 * This is for locking debugging only. I removed spinlocks and now I
	 * check whether .prepare is ever called on a linked buffer, or whether
	 * a dma IRQ can occur for an in-work or unlinked buffer. Until now
	 * it hadn't triggered
	 */
	for (i = 0; i < p->count; i++) {
		struct mx1_buffer *buf = container_of(icf->vb_vidq.bufs[i],
						      struct mx1_buffer, vb);
		buf->inwork = 0;
		INIT_LIST_HEAD(&buf->vb.queue);
	}

	return 0;
}

static unsigned int mx1_camera_poll(struct file *file, poll_table *pt)
{
	struct soc_camera_file *icf = file->private_data;
	struct mx1_buffer *buf;

	buf = list_entry(icf->vb_vidq.stream.next, struct mx1_buffer,
			 vb.stream);

	poll_wait(file, &buf->vb.done, pt);

	if (buf->vb.state == VIDEOBUF_DONE ||
	    buf->vb.state == VIDEOBUF_ERROR)
		return POLLIN | POLLRDNORM;

	return 0;
}

static int mx1_camera_querycap(struct soc_camera_host *ici,
			       struct v4l2_capability *cap)
{
	/* cap->name is set by the friendly caller:-> */
	strlcpy(cap->card, "i.MX1/i.MXL Camera", sizeof(cap->card));
	cap->version = VERSION_CODE;
	cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;

	return 0;
}

static struct soc_camera_host_ops mx1_soc_camera_host_ops = {
	.owner		= THIS_MODULE,
	.add		= mx1_camera_add_device,
	.remove		= mx1_camera_remove_device,
	.set_bus_param	= mx1_camera_set_bus_param,
	.set_crop	= mx1_camera_set_crop,
	.set_fmt	= mx1_camera_set_fmt,
	.try_fmt	= mx1_camera_try_fmt,
	.init_videobuf	= mx1_camera_init_videobuf,
	.reqbufs	= mx1_camera_reqbufs,
	.poll		= mx1_camera_poll,
	.querycap	= mx1_camera_querycap,
};

static struct fiq_handler fh = {
	.name		= "csi_sof"
};

static int __init mx1_camera_probe(struct platform_device *pdev)
{
	struct mx1_camera_dev *pcdev;
	struct resource *res;
	struct pt_regs regs;
	struct clk *clk;
	void __iomem *base;
	unsigned int irq;
	int err = 0;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	irq = platform_get_irq(pdev, 0);
	if (!res || !irq) {
		err = -ENODEV;
		goto exit;
	}

	clk = clk_get(&pdev->dev, "csi_clk");
	if (IS_ERR(clk)) {
		err = PTR_ERR(clk);
		goto exit;
	}

	pcdev = kzalloc(sizeof(*pcdev), GFP_KERNEL);
	if (!pcdev) {
		dev_err(&pdev->dev, "Could not allocate pcdev\n");
		err = -ENOMEM;
		goto exit_put_clk;
	}

	pcdev->res = res;
	pcdev->clk = clk;

	pcdev->pdata = pdev->dev.platform_data;

	if (pcdev->pdata)
		pcdev->mclk = pcdev->pdata->mclk_10khz * 10000;

	if (!pcdev->mclk) {
		dev_warn(&pdev->dev,
			 "mclk_10khz == 0! Please, fix your platform data. "
			 "Using default 20MHz\n");
		pcdev->mclk = 20000000;
	}

	INIT_LIST_HEAD(&pcdev->capture);
	spin_lock_init(&pcdev->lock);

	/*
	 * Request the regions.
	 */
	if (!request_mem_region(res->start, resource_size(res), DRIVER_NAME)) {
		err = -EBUSY;
		goto exit_kfree;
	}

	base = ioremap(res->start, resource_size(res));
	if (!base) {
		err = -ENOMEM;
		goto exit_release;
	}
	pcdev->irq = irq;
	pcdev->base = base;

	/* request dma */
	pcdev->dma_chan = imx_dma_request_by_prio(DRIVER_NAME, DMA_PRIO_HIGH);
	if (pcdev->dma_chan < 0) {
		dev_err(&pdev->dev, "Can't request DMA for MX1 CSI\n");
		err = -EBUSY;
		goto exit_iounmap;
	}
	dev_dbg(&pdev->dev, "got DMA channel %d\n", pcdev->dma_chan);

	imx_dma_setup_handlers(pcdev->dma_chan, mx1_camera_dma_irq, NULL,
			       pcdev);

	imx_dma_config_channel(pcdev->dma_chan, IMX_DMA_TYPE_FIFO,
			       IMX_DMA_MEMSIZE_32, DMA_REQ_CSI_R, 0);
	/* burst length : 16 words = 64 bytes */
	imx_dma_config_burstlen(pcdev->dma_chan, 0);

	/* request irq */
	err = claim_fiq(&fh);
	if (err) {
		dev_err(&pdev->dev, "Camera interrupt register failed \n");
		goto exit_free_dma;
	}

	set_fiq_handler(&mx1_camera_sof_fiq_start, &mx1_camera_sof_fiq_end -
						   &mx1_camera_sof_fiq_start);

	regs.ARM_r8 = DMA_BASE + DMA_DIMR;
	regs.ARM_r9 = DMA_BASE + DMA_CCR(pcdev->dma_chan);
	regs.ARM_r10 = (long)pcdev->base + CSICR1;
	regs.ARM_fp = (long)pcdev->base + CSISR;
	regs.ARM_sp = 1 << pcdev->dma_chan;
	set_fiq_regs(&regs);

	mxc_set_irq_fiq(irq, 1);
	enable_fiq(irq);

	pcdev->soc_host.drv_name	= DRIVER_NAME;
	pcdev->soc_host.ops		= &mx1_soc_camera_host_ops;
	pcdev->soc_host.priv		= pcdev;
	pcdev->soc_host.v4l2_dev.dev	= &pdev->dev;
	pcdev->soc_host.nr		= pdev->id;
	err = soc_camera_host_register(&pcdev->soc_host);
	if (err)
		goto exit_free_irq;

	dev_info(&pdev->dev, "MX1 Camera driver loaded\n");

	return 0;

exit_free_irq:
	disable_fiq(irq);
	mxc_set_irq_fiq(irq, 0);
	release_fiq(&fh);
exit_free_dma:
	imx_dma_free(pcdev->dma_chan);
exit_iounmap:
	iounmap(base);
exit_release:
	release_mem_region(res->start, resource_size(res));
exit_kfree:
	kfree(pcdev);
exit_put_clk:
	clk_put(clk);
exit:
	return err;
}

static int __exit mx1_camera_remove(struct platform_device *pdev)
{
	struct soc_camera_host *soc_host = to_soc_camera_host(&pdev->dev);
	struct mx1_camera_dev *pcdev = container_of(soc_host,
					struct mx1_camera_dev, soc_host);
	struct resource *res;

	imx_dma_free(pcdev->dma_chan);
	disable_fiq(pcdev->irq);
	mxc_set_irq_fiq(pcdev->irq, 0);
	release_fiq(&fh);

	clk_put(pcdev->clk);

	soc_camera_host_unregister(soc_host);

	iounmap(pcdev->base);

	res = pcdev->res;
	release_mem_region(res->start, resource_size(res));

	kfree(pcdev);

	dev_info(&pdev->dev, "MX1 Camera driver unloaded\n");

	return 0;
}

static struct platform_driver mx1_camera_driver = {
	.driver 	= {
		.name	= DRIVER_NAME,
	},
	.remove		= __exit_p(mx1_camera_remove),
};

static int __init mx1_camera_init(void)
{
	return platform_driver_probe(&mx1_camera_driver, mx1_camera_probe);
}

static void __exit mx1_camera_exit(void)
{
	return platform_driver_unregister(&mx1_camera_driver);
}

module_init(mx1_camera_init);
module_exit(mx1_camera_exit);

MODULE_DESCRIPTION("i.MX1/i.MXL SoC Camera Host driver");
MODULE_AUTHOR("Paulius Zaleckas <paulius.zaleckas@teltonika.lt>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRIVER_NAME);