summaryrefslogtreecommitdiff
path: root/drivers/media/usb/stkwebcam/stk-sensor.c
blob: fbccbb2eed9f4accaf8644c961573542eda2ece2 (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
/* stk-sensor.c: Driver for ov96xx sensor (used in some Syntek webcams)
 *
 * Copyright 2007-2008 Jaime Velasco Juan <jsagarribay@gmail.com>
 *
 * Some parts derived from ov7670.c:
 * Copyright 2006 One Laptop Per Child Association, Inc.  Written
 * by Jonathan Corbet with substantial inspiration from Mark
 * McClelland's ovcamchip code.
 *
 * Copyright 2006-7 Jonathan Corbet <corbet@lwn.net>
 *
 * This file may be distributed under the terms of the GNU General
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/* Controlling the sensor via the STK1125 vendor specific control interface:
 * The camera uses an OmniVision sensor and the stk1125 provides an
 * SCCB(i2c)-USB bridge which let us program the sensor.
 * In my case the sensor id is 0x9652, it can be read from sensor's register
 * 0x0A and 0x0B as follows:
 * - read register #R:
 *   output #R to index 0x0208
 *   output 0x0070 to index 0x0200
 *   input 1 byte from index 0x0201 (some kind of status register)
 *     until its value is 0x01
 *   input 1 byte from index 0x0209. This is the value of #R
 * - write value V to register #R
 *   output #R to index 0x0204
 *   output V to index 0x0205
 *   output 0x0005 to index 0x0200
 *   input 1 byte from index 0x0201 until its value becomes 0x04
 */

/* It seems the i2c bus is controlled with these registers */

#include "stk-webcam.h"

#define STK_IIC_BASE		(0x0200)
#  define STK_IIC_OP		(STK_IIC_BASE)
#    define STK_IIC_OP_TX	(0x05)
#    define STK_IIC_OP_RX	(0x70)
#  define STK_IIC_STAT		(STK_IIC_BASE+1)
#    define STK_IIC_STAT_TX_OK	(0x04)
#    define STK_IIC_STAT_RX_OK	(0x01)
/* I don't know what does this register.
 * when it is 0x00 or 0x01, we cannot talk to the sensor,
 * other values work */
#  define STK_IIC_ENABLE	(STK_IIC_BASE+2)
#    define STK_IIC_ENABLE_NO	(0x00)
/* This is what the driver writes in windows */
#    define STK_IIC_ENABLE_YES	(0x1e)
/*
 * Address of the slave. Seems like the binary driver look for the
 * sensor in multiple places, attempting a reset sequence.
 * We only know about the ov9650
 */
#  define STK_IIC_ADDR		(STK_IIC_BASE+3)
#  define STK_IIC_TX_INDEX	(STK_IIC_BASE+4)
#  define STK_IIC_TX_VALUE	(STK_IIC_BASE+5)
#  define STK_IIC_RX_INDEX	(STK_IIC_BASE+8)
#  define STK_IIC_RX_VALUE	(STK_IIC_BASE+9)

#define MAX_RETRIES		(50)

#define SENSOR_ADDRESS		(0x60)

/* From ov7670.c (These registers aren't fully accurate) */

/* Registers */
#define REG_GAIN	0x00	/* Gain lower 8 bits (rest in vref) */
#define REG_BLUE	0x01	/* blue gain */
#define REG_RED		0x02	/* red gain */
#define REG_VREF	0x03	/* Pieces of GAIN, VSTART, VSTOP */
#define REG_COM1	0x04	/* Control 1 */
#define  COM1_CCIR656	  0x40  /* CCIR656 enable */
#define  COM1_QFMT	  0x20  /* QVGA/QCIF format */
#define  COM1_SKIP_0	  0x00  /* Do not skip any row */
#define  COM1_SKIP_2	  0x04  /* Skip 2 rows of 4 */
#define  COM1_SKIP_3	  0x08  /* Skip 3 rows of 4 */
#define REG_BAVE	0x05	/* U/B Average level */
#define REG_GbAVE	0x06	/* Y/Gb Average level */
#define REG_AECHH	0x07	/* AEC MS 5 bits */
#define REG_RAVE	0x08	/* V/R Average level */
#define REG_COM2	0x09	/* Control 2 */
#define  COM2_SSLEEP	  0x10	/* Soft sleep mode */
#define REG_PID		0x0a	/* Product ID MSB */
#define REG_VER		0x0b	/* Product ID LSB */
#define REG_COM3	0x0c	/* Control 3 */
#define  COM3_SWAP	  0x40	  /* Byte swap */
#define  COM3_SCALEEN	  0x08	  /* Enable scaling */
#define  COM3_DCWEN	  0x04	  /* Enable downsamp/crop/window */
#define REG_COM4	0x0d	/* Control 4 */
#define REG_COM5	0x0e	/* All "reserved" */
#define REG_COM6	0x0f	/* Control 6 */
#define REG_AECH	0x10	/* More bits of AEC value */
#define REG_CLKRC	0x11	/* Clock control */
#define   CLK_PLL	  0x80	  /* Enable internal PLL */
#define   CLK_EXT	  0x40	  /* Use external clock directly */
#define   CLK_SCALE	  0x3f	  /* Mask for internal clock scale */
#define REG_COM7	0x12	/* Control 7 */
#define   COM7_RESET	  0x80	  /* Register reset */
#define   COM7_FMT_MASK	  0x38
#define   COM7_FMT_SXGA	  0x00
#define   COM7_FMT_VGA	  0x40
#define	  COM7_FMT_CIF	  0x20	  /* CIF format */
#define   COM7_FMT_QVGA	  0x10	  /* QVGA format */
#define   COM7_FMT_QCIF	  0x08	  /* QCIF format */
#define	  COM7_RGB	  0x04	  /* bits 0 and 2 - RGB format */
#define	  COM7_YUV	  0x00	  /* YUV */
#define	  COM7_BAYER	  0x01	  /* Bayer format */
#define	  COM7_PBAYER	  0x05	  /* "Processed bayer" */
#define REG_COM8	0x13	/* Control 8 */
#define   COM8_FASTAEC	  0x80	  /* Enable fast AGC/AEC */
#define   COM8_AECSTEP	  0x40	  /* Unlimited AEC step size */
#define   COM8_BFILT	  0x20	  /* Band filter enable */
#define   COM8_AGC	  0x04	  /* Auto gain enable */
#define   COM8_AWB	  0x02	  /* White balance enable */
#define   COM8_AEC	  0x01	  /* Auto exposure enable */
#define REG_COM9	0x14	/* Control 9  - gain ceiling */
#define REG_COM10	0x15	/* Control 10 */
#define   COM10_HSYNC	  0x40	  /* HSYNC instead of HREF */
#define   COM10_PCLK_HB	  0x20	  /* Suppress PCLK on horiz blank */
#define   COM10_HREF_REV  0x08	  /* Reverse HREF */
#define   COM10_VS_LEAD	  0x04	  /* VSYNC on clock leading edge */
#define   COM10_VS_NEG	  0x02	  /* VSYNC negative */
#define   COM10_HS_NEG	  0x01	  /* HSYNC negative */
#define REG_HSTART	0x17	/* Horiz start high bits */
#define REG_HSTOP	0x18	/* Horiz stop high bits */
#define REG_VSTART	0x19	/* Vert start high bits */
#define REG_VSTOP	0x1a	/* Vert stop high bits */
#define REG_PSHFT	0x1b	/* Pixel delay after HREF */
#define REG_MIDH	0x1c	/* Manuf. ID high */
#define REG_MIDL	0x1d	/* Manuf. ID low */
#define REG_MVFP	0x1e	/* Mirror / vflip */
#define   MVFP_MIRROR	  0x20	  /* Mirror image */
#define   MVFP_FLIP	  0x10	  /* Vertical flip */

#define REG_AEW		0x24	/* AGC upper limit */
#define REG_AEB		0x25	/* AGC lower limit */
#define REG_VPT		0x26	/* AGC/AEC fast mode op region */
#define REG_ADVFL	0x2d	/* Insert dummy lines (LSB) */
#define REG_ADVFH	0x2e	/* Insert dummy lines (MSB) */
#define REG_HSYST	0x30	/* HSYNC rising edge delay */
#define REG_HSYEN	0x31	/* HSYNC falling edge delay */
#define REG_HREF	0x32	/* HREF pieces */
#define REG_TSLB	0x3a	/* lots of stuff */
#define   TSLB_YLAST	  0x04	  /* UYVY or VYUY - see com13 */
#define   TSLB_BYTEORD	  0x08	  /* swap bytes in 16bit mode? */
#define REG_COM11	0x3b	/* Control 11 */
#define   COM11_NIGHT	  0x80	  /* NIght mode enable */
#define   COM11_NMFR	  0x60	  /* Two bit NM frame rate */
#define   COM11_HZAUTO	  0x10	  /* Auto detect 50/60 Hz */
#define	  COM11_50HZ	  0x08	  /* Manual 50Hz select */
#define   COM11_EXP	  0x02
#define REG_COM12	0x3c	/* Control 12 */
#define   COM12_HREF	  0x80	  /* HREF always */
#define REG_COM13	0x3d	/* Control 13 */
#define   COM13_GAMMA	  0x80	  /* Gamma enable */
#define	  COM13_UVSAT	  0x40	  /* UV saturation auto adjustment */
#define	  COM13_CMATRIX	  0x10	  /* Enable color matrix for RGB or YUV */
#define   COM13_UVSWAP	  0x01	  /* V before U - w/TSLB */
#define REG_COM14	0x3e	/* Control 14 */
#define   COM14_DCWEN	  0x10	  /* DCW/PCLK-scale enable */
#define REG_EDGE	0x3f	/* Edge enhancement factor */
#define REG_COM15	0x40	/* Control 15 */
#define   COM15_R10F0	  0x00	  /* Data range 10 to F0 */
#define	  COM15_R01FE	  0x80	  /*            01 to FE */
#define   COM15_R00FF	  0xc0	  /*            00 to FF */
#define   COM15_RGB565	  0x10	  /* RGB565 output */
#define   COM15_RGBFIXME	  0x20	  /* FIXME  */
#define   COM15_RGB555	  0x30	  /* RGB555 output */
#define REG_COM16	0x41	/* Control 16 */
#define   COM16_AWBGAIN   0x08	  /* AWB gain enable */
#define REG_COM17	0x42	/* Control 17 */
#define   COM17_AECWIN	  0xc0	  /* AEC window - must match COM4 */
#define   COM17_CBAR	  0x08	  /* DSP Color bar */

/*
 * This matrix defines how the colors are generated, must be
 * tweaked to adjust hue and saturation.
 *
 * Order: v-red, v-green, v-blue, u-red, u-green, u-blue
 *
 * They are nine-bit signed quantities, with the sign bit
 * stored in 0x58.  Sign for v-red is bit 0, and up from there.
 */
#define	REG_CMATRIX_BASE 0x4f
#define   CMATRIX_LEN 6
#define REG_CMATRIX_SIGN 0x58


#define REG_BRIGHT	0x55	/* Brightness */
#define REG_CONTRAS	0x56	/* Contrast control */

#define REG_GFIX	0x69	/* Fix gain control */

#define REG_RGB444	0x8c	/* RGB 444 control */
#define   R444_ENABLE	  0x02	  /* Turn on RGB444, overrides 5x5 */
#define   R444_RGBX	  0x01	  /* Empty nibble at end */

#define REG_HAECC1	0x9f	/* Hist AEC/AGC control 1 */
#define REG_HAECC2	0xa0	/* Hist AEC/AGC control 2 */

#define REG_BD50MAX	0xa5	/* 50hz banding step limit */
#define REG_HAECC3	0xa6	/* Hist AEC/AGC control 3 */
#define REG_HAECC4	0xa7	/* Hist AEC/AGC control 4 */
#define REG_HAECC5	0xa8	/* Hist AEC/AGC control 5 */
#define REG_HAECC6	0xa9	/* Hist AEC/AGC control 6 */
#define REG_HAECC7	0xaa	/* Hist AEC/AGC control 7 */
#define REG_BD60MAX	0xab	/* 60hz banding step limit */




/* Returns 0 if OK */
static int stk_sensor_outb(struct stk_camera *dev, u8 reg, u8 val)
{
	int i = 0;
	u8 tmpval = 0;

	if (stk_camera_write_reg(dev, STK_IIC_TX_INDEX, reg))
		return 1;
	if (stk_camera_write_reg(dev, STK_IIC_TX_VALUE, val))
		return 1;
	if (stk_camera_write_reg(dev, STK_IIC_OP, STK_IIC_OP_TX))
		return 1;
	do {
		if (stk_camera_read_reg(dev, STK_IIC_STAT, &tmpval))
			return 1;
		i++;
	} while (tmpval == 0 && i < MAX_RETRIES);
	if (tmpval != STK_IIC_STAT_TX_OK) {
		if (tmpval)
			STK_ERROR("stk_sensor_outb failed, status=0x%02x\n",
				tmpval);
		return 1;
	} else
		return 0;
}

static int stk_sensor_inb(struct stk_camera *dev, u8 reg, u8 *val)
{
	int i = 0;
	u8 tmpval = 0;

	if (stk_camera_write_reg(dev, STK_IIC_RX_INDEX, reg))
		return 1;
	if (stk_camera_write_reg(dev, STK_IIC_OP, STK_IIC_OP_RX))
		return 1;
	do {
		if (stk_camera_read_reg(dev, STK_IIC_STAT, &tmpval))
			return 1;
		i++;
	} while (tmpval == 0 && i < MAX_RETRIES);
	if (tmpval != STK_IIC_STAT_RX_OK) {
		if (tmpval)
			STK_ERROR("stk_sensor_inb failed, status=0x%02x\n",
				tmpval);
		return 1;
	}

	if (stk_camera_read_reg(dev, STK_IIC_RX_VALUE, &tmpval))
		return 1;

	*val = tmpval;
	return 0;
}

static int stk_sensor_write_regvals(struct stk_camera *dev,
		struct regval *rv)
{
	int ret;
	if (rv == NULL)
		return 0;
	while (rv->reg != 0xff || rv->val != 0xff) {
		ret = stk_sensor_outb(dev, rv->reg, rv->val);
		if (ret != 0)
			return ret;
		rv++;
	}
	return 0;
}

int stk_sensor_sleep(struct stk_camera *dev)
{
	u8 tmp;
	return stk_sensor_inb(dev, REG_COM2, &tmp)
		|| stk_sensor_outb(dev, REG_COM2, tmp|COM2_SSLEEP);
}

int stk_sensor_wakeup(struct stk_camera *dev)
{
	u8 tmp;
	return stk_sensor_inb(dev, REG_COM2, &tmp)
		|| stk_sensor_outb(dev, REG_COM2, tmp&~COM2_SSLEEP);
}

static struct regval ov_initvals[] = {
	{REG_CLKRC, CLK_PLL},
	{REG_COM11, 0x01},
	{0x6a, 0x7d},
	{REG_AECH, 0x40},
	{REG_GAIN, 0x00},
	{REG_BLUE, 0x80},
	{REG_RED, 0x80},
	/* Do not enable fast AEC for now */
	/*{REG_COM8, COM8_FASTAEC|COM8_AECSTEP|COM8_BFILT|COM8_AGC|COM8_AEC},*/
	{REG_COM8, COM8_AECSTEP|COM8_BFILT|COM8_AGC|COM8_AEC},
	{0x39, 0x50}, {0x38, 0x93},
	{0x37, 0x00}, {0x35, 0x81},
	{REG_COM5, 0x20},
	{REG_COM1, 0x00},
	{REG_COM3, 0x00},
	{REG_COM4, 0x00},
	{REG_PSHFT, 0x00},
	{0x16, 0x07},
	{0x33, 0xe2}, {0x34, 0xbf},
	{REG_COM16, 0x00},
	{0x96, 0x04},
	/* Gamma curve values */
/*	{ 0x7a, 0x20 },		{ 0x7b, 0x10 },
	{ 0x7c, 0x1e },		{ 0x7d, 0x35 },
	{ 0x7e, 0x5a },		{ 0x7f, 0x69 },
	{ 0x80, 0x76 },		{ 0x81, 0x80 },
	{ 0x82, 0x88 },		{ 0x83, 0x8f },
	{ 0x84, 0x96 },		{ 0x85, 0xa3 },
	{ 0x86, 0xaf },		{ 0x87, 0xc4 },
	{ 0x88, 0xd7 },		{ 0x89, 0xe8 },
*/
	{REG_GFIX, 0x40},
	{0x8e, 0x00},
	{REG_COM12, 0x73},
	{0x8f, 0xdf}, {0x8b, 0x06},
	{0x8c, 0x20},
	{0x94, 0x88}, {0x95, 0x88},
/*	{REG_COM15, 0xc1}, TODO */
	{0x29, 0x3f},
	{REG_COM6, 0x42},
	{REG_BD50MAX, 0x80},
	{REG_HAECC6, 0xb8}, {REG_HAECC7, 0x92},
	{REG_BD60MAX, 0x0a},
	{0x90, 0x00}, {0x91, 0x00},
	{REG_HAECC1, 0x00}, {REG_HAECC2, 0x00},
	{REG_AEW, 0x68}, {REG_AEB, 0x5c},
	{REG_VPT, 0xc3},
	{REG_COM9, 0x2e},
	{0x2a, 0x00}, {0x2b, 0x00},

	{0xff, 0xff}, /* END MARKER */
};

/* Probe the I2C bus and initialise the sensor chip */
int stk_sensor_init(struct stk_camera *dev)
{
	u8 idl = 0;
	u8 idh = 0;

	if (stk_camera_write_reg(dev, STK_IIC_ENABLE, STK_IIC_ENABLE_YES)
		|| stk_camera_write_reg(dev, STK_IIC_ADDR, SENSOR_ADDRESS)
		|| stk_sensor_outb(dev, REG_COM7, COM7_RESET)) {
		STK_ERROR("Sensor resetting failed\n");
		return -ENODEV;
	}
	msleep(10);
	/* Read the manufacturer ID: ov = 0x7FA2 */
	if (stk_sensor_inb(dev, REG_MIDH, &idh)
	    || stk_sensor_inb(dev, REG_MIDL, &idl)) {
		STK_ERROR("Strange error reading sensor ID\n");
		return -ENODEV;
	}
	if (idh != 0x7f || idl != 0xa2) {
		STK_ERROR("Huh? you don't have a sensor from ovt\n");
		return -ENODEV;
	}
	if (stk_sensor_inb(dev, REG_PID, &idh)
	    || stk_sensor_inb(dev, REG_VER, &idl)) {
		STK_ERROR("Could not read sensor model\n");
		return -ENODEV;
	}
	stk_sensor_write_regvals(dev, ov_initvals);
	msleep(10);
	STK_INFO("OmniVision sensor detected, id %02X%02X at address %x\n",
		 idh, idl, SENSOR_ADDRESS);
	return 0;
}

/* V4L2_PIX_FMT_UYVY */
static struct regval ov_fmt_uyvy[] = {
	{REG_TSLB, TSLB_YLAST|0x08 },
	{ 0x4f, 0x80 }, 	/* "matrix coefficient 1" */
	{ 0x50, 0x80 }, 	/* "matrix coefficient 2" */
	{ 0x51, 0    },		/* vb */
	{ 0x52, 0x22 }, 	/* "matrix coefficient 4" */
	{ 0x53, 0x5e }, 	/* "matrix coefficient 5" */
	{ 0x54, 0x80 }, 	/* "matrix coefficient 6" */
	{REG_COM13, COM13_UVSAT|COM13_CMATRIX},
	{REG_COM15, COM15_R00FF },
	{0xff, 0xff}, /* END MARKER */
};
/* V4L2_PIX_FMT_YUYV */
static struct regval ov_fmt_yuyv[] = {
	{REG_TSLB, 0 },
	{ 0x4f, 0x80 }, 	/* "matrix coefficient 1" */
	{ 0x50, 0x80 }, 	/* "matrix coefficient 2" */
	{ 0x51, 0    },		/* vb */
	{ 0x52, 0x22 }, 	/* "matrix coefficient 4" */
	{ 0x53, 0x5e }, 	/* "matrix coefficient 5" */
	{ 0x54, 0x80 }, 	/* "matrix coefficient 6" */
	{REG_COM13, COM13_UVSAT|COM13_CMATRIX},
	{REG_COM15, COM15_R00FF },
	{0xff, 0xff}, /* END MARKER */
};

/* V4L2_PIX_FMT_RGB565X rrrrrggg gggbbbbb */
static struct regval ov_fmt_rgbr[] = {
	{ REG_RGB444, 0 },	/* No RGB444 please */
	{REG_TSLB, 0x00},
	{ REG_COM1, 0x0 },
	{ REG_COM9, 0x38 }, 	/* 16x gain ceiling; 0x8 is reserved bit */
	{ 0x4f, 0xb3 }, 	/* "matrix coefficient 1" */
	{ 0x50, 0xb3 }, 	/* "matrix coefficient 2" */
	{ 0x51, 0    },		/* vb */
	{ 0x52, 0x3d }, 	/* "matrix coefficient 4" */
	{ 0x53, 0xa7 }, 	/* "matrix coefficient 5" */
	{ 0x54, 0xe4 }, 	/* "matrix coefficient 6" */
	{ REG_COM13, COM13_GAMMA },
	{ REG_COM15, COM15_RGB565|COM15_R00FF },
	{ 0xff, 0xff },
};

/* V4L2_PIX_FMT_RGB565 gggbbbbb rrrrrggg */
static struct regval ov_fmt_rgbp[] = {
	{ REG_RGB444, 0 },	/* No RGB444 please */
	{REG_TSLB, TSLB_BYTEORD },
	{ REG_COM1, 0x0 },
	{ REG_COM9, 0x38 }, 	/* 16x gain ceiling; 0x8 is reserved bit */
	{ 0x4f, 0xb3 }, 	/* "matrix coefficient 1" */
	{ 0x50, 0xb3 }, 	/* "matrix coefficient 2" */
	{ 0x51, 0    },		/* vb */
	{ 0x52, 0x3d }, 	/* "matrix coefficient 4" */
	{ 0x53, 0xa7 }, 	/* "matrix coefficient 5" */
	{ 0x54, 0xe4 }, 	/* "matrix coefficient 6" */
	{ REG_COM13, COM13_GAMMA },
	{ REG_COM15, COM15_RGB565|COM15_R00FF },
	{ 0xff, 0xff },
};

/* V4L2_PIX_FMT_SRGGB8 */
static struct regval ov_fmt_bayer[] = {
	/* This changes color order */
	{REG_TSLB, 0x40}, /* BGGR */
	/* {REG_TSLB, 0x08}, */ /* BGGR with vertical image flipping */
	{REG_COM15, COM15_R00FF },
	{0xff, 0xff}, /* END MARKER */
};
/*
 * Store a set of start/stop values into the camera.
 */
static int stk_sensor_set_hw(struct stk_camera *dev,
		int hstart, int hstop, int vstart, int vstop)
{
	int ret;
	unsigned char v;
/*
 * Horizontal: 11 bits, top 8 live in hstart and hstop.  Bottom 3 of
 * hstart are in href[2:0], bottom 3 of hstop in href[5:3].  There is
 * a mystery "edge offset" value in the top two bits of href.
 */
	ret =  stk_sensor_outb(dev, REG_HSTART, (hstart >> 3) & 0xff);
	ret += stk_sensor_outb(dev, REG_HSTOP, (hstop >> 3) & 0xff);
	ret += stk_sensor_inb(dev, REG_HREF, &v);
	v = (v & 0xc0) | ((hstop & 0x7) << 3) | (hstart & 0x7);
	msleep(10);
	ret += stk_sensor_outb(dev, REG_HREF, v);
/*
 * Vertical: similar arrangement (note: this is different from ov7670.c)
 */
	ret += stk_sensor_outb(dev, REG_VSTART, (vstart >> 3) & 0xff);
	ret += stk_sensor_outb(dev, REG_VSTOP, (vstop >> 3) & 0xff);
	ret += stk_sensor_inb(dev, REG_VREF, &v);
	v = (v & 0xc0) | ((vstop & 0x7) << 3) | (vstart & 0x7);
	msleep(10);
	ret += stk_sensor_outb(dev, REG_VREF, v);
	return ret;
}


int stk_sensor_configure(struct stk_camera *dev)
{
	int com7;
	/*
	 * We setup the sensor to output dummy lines in low-res modes,
	 * so we don't get absurdly hight framerates.
	 */
	unsigned dummylines;
	int flip;
	struct regval *rv;

	switch (dev->vsettings.mode) {
	case MODE_QCIF: com7 = COM7_FMT_QCIF;
		dummylines = 604;
		break;
	case MODE_QVGA: com7 = COM7_FMT_QVGA;
		dummylines = 267;
		break;
	case MODE_CIF: com7 = COM7_FMT_CIF;
		dummylines = 412;
		break;
	case MODE_VGA: com7 = COM7_FMT_VGA;
		dummylines = 11;
		break;
	case MODE_SXGA: com7 = COM7_FMT_SXGA;
		dummylines = 0;
		break;
	default: STK_ERROR("Unsupported mode %d\n", dev->vsettings.mode);
		return -EFAULT;
	}
	switch (dev->vsettings.palette) {
	case V4L2_PIX_FMT_UYVY:
		com7 |= COM7_YUV;
		rv = ov_fmt_uyvy;
		break;
	case V4L2_PIX_FMT_YUYV:
		com7 |= COM7_YUV;
		rv = ov_fmt_yuyv;
		break;
	case V4L2_PIX_FMT_RGB565:
		com7 |= COM7_RGB;
		rv = ov_fmt_rgbp;
		break;
	case V4L2_PIX_FMT_RGB565X:
		com7 |= COM7_RGB;
		rv = ov_fmt_rgbr;
		break;
	case V4L2_PIX_FMT_SBGGR8:
		com7 |= COM7_PBAYER;
		rv = ov_fmt_bayer;
		break;
	default: STK_ERROR("Unsupported colorspace\n");
		return -EFAULT;
	}
	/*FIXME sometimes the sensor go to a bad state
	stk_sensor_write_regvals(dev, ov_initvals); */
	stk_sensor_outb(dev, REG_COM7, com7);
	msleep(50);
	stk_sensor_write_regvals(dev, rv);
	flip = (dev->vsettings.vflip?MVFP_FLIP:0)
		| (dev->vsettings.hflip?MVFP_MIRROR:0);
	stk_sensor_outb(dev, REG_MVFP, flip);
	if (dev->vsettings.palette == V4L2_PIX_FMT_SBGGR8
			&& !dev->vsettings.vflip)
		stk_sensor_outb(dev, REG_TSLB, 0x08);
	stk_sensor_outb(dev, REG_ADVFH, dummylines >> 8);
	stk_sensor_outb(dev, REG_ADVFL, dummylines & 0xff);
	msleep(50);
	switch (dev->vsettings.mode) {
	case MODE_VGA:
		if (stk_sensor_set_hw(dev, 302, 1582, 6, 486))
			STK_ERROR("stk_sensor_set_hw failed (VGA)\n");
		break;
	case MODE_SXGA:
	case MODE_CIF:
	case MODE_QVGA:
	case MODE_QCIF:
		/*FIXME These settings seem ignored by the sensor
		if (stk_sensor_set_hw(dev, 220, 1500, 10, 1034))
			STK_ERROR("stk_sensor_set_hw failed (SXGA)\n");
		*/
		break;
	}
	msleep(10);
	return 0;
}

int stk_sensor_set_brightness(struct stk_camera *dev, int br)
{
	if (br < 0 || br > 0xff)
		return -EINVAL;
	stk_sensor_outb(dev, REG_AEB, max(0x00, br - 6));
	stk_sensor_outb(dev, REG_AEW, min(0xff, br + 6));
	return 0;
}