2 * A V4L2 driver for OmniVision OV7670 cameras.
4 * Copyright 2006 One Laptop Per Child Association, Inc. Written
5 * by Jonathan Corbet with substantial inspiration from Mark
6 * McClelland's ovcamchip code.
8 * This file may be distributed under the terms of the GNU General
9 * Public License, version 2.
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/moduleparam.h>
14 #include <linux/slab.h>
15 #include <linux/delay.h>
16 #include <linux/videodev.h>
17 #include <media/v4l2-common.h>
18 #include <linux/i2c.h>
21 MODULE_AUTHOR("Jonathan Corbet <corbet@lwn.net>");
22 MODULE_DESCRIPTION("A low-level driver for OmniVision ov7670 sensors");
23 MODULE_LICENSE("GPL");
26 * Basic window sizes. These probably belong somewhere more globally
30 #define VGA_HEIGHT 480
31 #define QVGA_WIDTH 320
32 #define QVGA_HEIGHT 240
34 #define CIF_HEIGHT 288
35 #define QCIF_WIDTH 176
36 #define QCIF_HEIGHT 144
39 * Our nominal (default) frame rate.
41 #define OV7670_FRAME_RATE 30
44 * The 7670 sits on i2c with ID 0x42
46 #define OV7670_I2C_ADDR 0x42
49 #define REG_GAIN 0x00 /* Gain lower 8 bits (rest in vref) */
50 #define REG_BLUE 0x01 /* blue gain */
51 #define REG_RED 0x02 /* red gain */
52 #define REG_VREF 0x03 /* Pieces of GAIN, VSTART, VSTOP */
53 #define REG_COM1 0x04 /* Control 1 */
54 #define COM1_CCIR656 0x40 /* CCIR656 enable */
55 #define REG_BAVE 0x05 /* U/B Average level */
56 #define REG_GbAVE 0x06 /* Y/Gb Average level */
57 #define REG_AECHH 0x07 /* AEC MS 5 bits */
58 #define REG_RAVE 0x08 /* V/R Average level */
59 #define REG_COM2 0x09 /* Control 2 */
60 #define COM2_SSLEEP 0x10 /* Soft sleep mode */
61 #define REG_PID 0x0a /* Product ID MSB */
62 #define REG_VER 0x0b /* Product ID LSB */
63 #define REG_COM3 0x0c /* Control 3 */
64 #define COM3_SWAP 0x40 /* Byte swap */
65 #define COM3_SCALEEN 0x08 /* Enable scaling */
66 #define COM3_DCWEN 0x04 /* Enable downsamp/crop/window */
67 #define REG_COM4 0x0d /* Control 4 */
68 #define REG_COM5 0x0e /* All "reserved" */
69 #define REG_COM6 0x0f /* Control 6 */
70 #define REG_AECH 0x10 /* More bits of AEC value */
71 #define REG_CLKRC 0x11 /* Clocl control */
72 #define CLK_EXT 0x40 /* Use external clock directly */
73 #define CLK_SCALE 0x3f /* Mask for internal clock scale */
74 #define REG_COM7 0x12 /* Control 7 */
75 #define COM7_RESET 0x80 /* Register reset */
76 #define COM7_FMT_MASK 0x38
77 #define COM7_FMT_VGA 0x00
78 #define COM7_FMT_CIF 0x20 /* CIF format */
79 #define COM7_FMT_QVGA 0x10 /* QVGA format */
80 #define COM7_FMT_QCIF 0x08 /* QCIF format */
81 #define COM7_RGB 0x04 /* bits 0 and 2 - RGB format */
82 #define COM7_YUV 0x00 /* YUV */
83 #define COM7_BAYER 0x01 /* Bayer format */
84 #define COM7_PBAYER 0x05 /* "Processed bayer" */
85 #define REG_COM8 0x13 /* Control 8 */
86 #define COM8_FASTAEC 0x80 /* Enable fast AGC/AEC */
87 #define COM8_AECSTEP 0x40 /* Unlimited AEC step size */
88 #define COM8_BFILT 0x20 /* Band filter enable */
89 #define COM8_AGC 0x04 /* Auto gain enable */
90 #define COM8_AWB 0x02 /* White balance enable */
91 #define COM8_AEC 0x01 /* Auto exposure enable */
92 #define REG_COM9 0x14 /* Control 9 - gain ceiling */
93 #define REG_COM10 0x15 /* Control 10 */
94 #define COM10_HSYNC 0x40 /* HSYNC instead of HREF */
95 #define COM10_PCLK_HB 0x20 /* Suppress PCLK on horiz blank */
96 #define COM10_HREF_REV 0x08 /* Reverse HREF */
97 #define COM10_VS_LEAD 0x04 /* VSYNC on clock leading edge */
98 #define COM10_VS_NEG 0x02 /* VSYNC negative */
99 #define COM10_HS_NEG 0x01 /* HSYNC negative */
100 #define REG_HSTART 0x17 /* Horiz start high bits */
101 #define REG_HSTOP 0x18 /* Horiz stop high bits */
102 #define REG_VSTART 0x19 /* Vert start high bits */
103 #define REG_VSTOP 0x1a /* Vert stop high bits */
104 #define REG_PSHFT 0x1b /* Pixel delay after HREF */
105 #define REG_MIDH 0x1c /* Manuf. ID high */
106 #define REG_MIDL 0x1d /* Manuf. ID low */
107 #define REG_MVFP 0x1e /* Mirror / vflip */
108 #define MVFP_MIRROR 0x20 /* Mirror image */
109 #define MVFP_FLIP 0x10 /* Vertical flip */
111 #define REG_AEW 0x24 /* AGC upper limit */
112 #define REG_AEB 0x25 /* AGC lower limit */
113 #define REG_VPT 0x26 /* AGC/AEC fast mode op region */
114 #define REG_HSYST 0x30 /* HSYNC rising edge delay */
115 #define REG_HSYEN 0x31 /* HSYNC falling edge delay */
116 #define REG_HREF 0x32 /* HREF pieces */
117 #define REG_TSLB 0x3a /* lots of stuff */
118 #define TSLB_YLAST 0x04 /* UYVY or VYUY - see com13 */
119 #define REG_COM11 0x3b /* Control 11 */
120 #define COM11_NIGHT 0x80 /* NIght mode enable */
121 #define COM11_NMFR 0x60 /* Two bit NM frame rate */
122 #define COM11_HZAUTO 0x10 /* Auto detect 50/60 Hz */
123 #define COM11_50HZ 0x08 /* Manual 50Hz select */
124 #define COM11_EXP 0x02
125 #define REG_COM12 0x3c /* Control 12 */
126 #define COM12_HREF 0x80 /* HREF always */
127 #define REG_COM13 0x3d /* Control 13 */
128 #define COM13_GAMMA 0x80 /* Gamma enable */
129 #define COM13_UVSAT 0x40 /* UV saturation auto adjustment */
130 #define COM13_UVSWAP 0x01 /* V before U - w/TSLB */
131 #define REG_COM14 0x3e /* Control 14 */
132 #define COM14_DCWEN 0x10 /* DCW/PCLK-scale enable */
133 #define REG_EDGE 0x3f /* Edge enhancement factor */
134 #define REG_COM15 0x40 /* Control 15 */
135 #define COM15_R10F0 0x00 /* Data range 10 to F0 */
136 #define COM15_R01FE 0x80 /* 01 to FE */
137 #define COM15_R00FF 0xc0 /* 00 to FF */
138 #define COM15_RGB565 0x10 /* RGB565 output */
139 #define COM15_RGB555 0x30 /* RGB555 output */
140 #define REG_COM16 0x41 /* Control 16 */
141 #define COM16_AWBGAIN 0x08 /* AWB gain enable */
142 #define REG_COM17 0x42 /* Control 17 */
143 #define COM17_AECWIN 0xc0 /* AEC window - must match COM4 */
144 #define COM17_CBAR 0x08 /* DSP Color bar */
147 * This matrix defines how the colors are generated, must be
148 * tweaked to adjust hue and saturation.
150 * Order: v-red, v-green, v-blue, u-red, u-green, u-blue
152 * They are nine-bit signed quantities, with the sign bit
153 * stored in 0x58. Sign for v-red is bit 0, and up from there.
155 #define REG_CMATRIX_BASE 0x4f
156 #define CMATRIX_LEN 6
157 #define REG_CMATRIX_SIGN 0x58
160 #define REG_BRIGHT 0x55 /* Brightness */
161 #define REG_CONTRAS 0x56 /* Contrast control */
163 #define REG_GFIX 0x69 /* Fix gain control */
165 #define REG_RGB444 0x8c /* RGB 444 control */
166 #define R444_ENABLE 0x02 /* Turn on RGB444, overrides 5x5 */
167 #define R444_RGBX 0x01 /* Empty nibble at end */
169 #define REG_HAECC1 0x9f /* Hist AEC/AGC control 1 */
170 #define REG_HAECC2 0xa0 /* Hist AEC/AGC control 2 */
172 #define REG_BD50MAX 0xa5 /* 50hz banding step limit */
173 #define REG_HAECC3 0xa6 /* Hist AEC/AGC control 3 */
174 #define REG_HAECC4 0xa7 /* Hist AEC/AGC control 4 */
175 #define REG_HAECC5 0xa8 /* Hist AEC/AGC control 5 */
176 #define REG_HAECC6 0xa9 /* Hist AEC/AGC control 6 */
177 #define REG_HAECC7 0xaa /* Hist AEC/AGC control 7 */
178 #define REG_BD60MAX 0xab /* 60hz banding step limit */
182 * Information we maintain about a known sensor.
184 struct ov7670_format_struct
; /* coming later */
186 struct ov7670_format_struct
*fmt
; /* Current format */
187 unsigned char sat
; /* Saturation value */
188 int hue
; /* Hue value */
195 * The default register settings, as obtained from OmniVision. There
196 * is really no making sense of most of these - lots of "reserved" values
199 * These settings give VGA YUYV.
203 unsigned char reg_num
;
207 static struct regval_list ov7670_default_regs
[] = {
208 { REG_COM7
, COM7_RESET
},
210 * Clock scale: 3 = 15fps
214 { REG_CLKRC
, 0x1 }, /* OV: clock scale (30 fps) */
215 { REG_TSLB
, 0x04 }, /* OV */
216 { REG_COM7
, 0 }, /* VGA */
218 * Set the hardware window. These values from OV don't entirely
219 * make sense - hstop is less than hstart. But they work...
221 { REG_HSTART
, 0x13 }, { REG_HSTOP
, 0x01 },
222 { REG_HREF
, 0xb6 }, { REG_VSTART
, 0x02 },
223 { REG_VSTOP
, 0x7a }, { REG_VREF
, 0x0a },
225 { REG_COM3
, 0 }, { REG_COM14
, 0 },
226 /* Mystery scaling numbers */
227 { 0x70, 0x3a }, { 0x71, 0x35 },
228 { 0x72, 0x11 }, { 0x73, 0xf0 },
229 { 0xa2, 0x02 }, { REG_COM10
, 0x0 },
231 /* Gamma curve values */
232 { 0x7a, 0x20 }, { 0x7b, 0x10 },
233 { 0x7c, 0x1e }, { 0x7d, 0x35 },
234 { 0x7e, 0x5a }, { 0x7f, 0x69 },
235 { 0x80, 0x76 }, { 0x81, 0x80 },
236 { 0x82, 0x88 }, { 0x83, 0x8f },
237 { 0x84, 0x96 }, { 0x85, 0xa3 },
238 { 0x86, 0xaf }, { 0x87, 0xc4 },
239 { 0x88, 0xd7 }, { 0x89, 0xe8 },
241 /* AGC and AEC parameters. Note we start by disabling those features,
242 then turn them only after tweaking the values. */
243 { REG_COM8
, COM8_FASTAEC
| COM8_AECSTEP
| COM8_BFILT
},
244 { REG_GAIN
, 0 }, { REG_AECH
, 0 },
245 { REG_COM4
, 0x40 }, /* magic reserved bit */
246 { REG_COM9
, 0x18 }, /* 4x gain + magic rsvd bit */
247 { REG_BD50MAX
, 0x05 }, { REG_BD60MAX
, 0x07 },
248 { REG_AEW
, 0x95 }, { REG_AEB
, 0x33 },
249 { REG_VPT
, 0xe3 }, { REG_HAECC1
, 0x78 },
250 { REG_HAECC2
, 0x68 }, { 0xa1, 0x03 }, /* magic */
251 { REG_HAECC3
, 0xd8 }, { REG_HAECC4
, 0xd8 },
252 { REG_HAECC5
, 0xf0 }, { REG_HAECC6
, 0x90 },
253 { REG_HAECC7
, 0x94 },
254 { REG_COM8
, COM8_FASTAEC
|COM8_AECSTEP
|COM8_BFILT
|COM8_AGC
|COM8_AEC
},
256 /* Almost all of these are magic "reserved" values. */
257 { REG_COM5
, 0x61 }, { REG_COM6
, 0x4b },
258 { 0x16, 0x02 }, { REG_MVFP
, 0x07|MVFP_MIRROR
},
259 { 0x21, 0x02 }, { 0x22, 0x91 },
260 { 0x29, 0x07 }, { 0x33, 0x0b },
261 { 0x35, 0x0b }, { 0x37, 0x1d },
262 { 0x38, 0x71 }, { 0x39, 0x2a },
263 { REG_COM12
, 0x78 }, { 0x4d, 0x40 },
264 { 0x4e, 0x20 }, { REG_GFIX
, 0 },
265 { 0x6b, 0x4a }, { 0x74, 0x10 },
266 { 0x8d, 0x4f }, { 0x8e, 0 },
267 { 0x8f, 0 }, { 0x90, 0 },
268 { 0x91, 0 }, { 0x96, 0 },
269 { 0x9a, 0 }, { 0xb0, 0x84 },
270 { 0xb1, 0x0c }, { 0xb2, 0x0e },
271 { 0xb3, 0x82 }, { 0xb8, 0x0a },
273 /* More reserved magic, some of which tweaks white balance */
274 { 0x43, 0x0a }, { 0x44, 0xf0 },
275 { 0x45, 0x34 }, { 0x46, 0x58 },
276 { 0x47, 0x28 }, { 0x48, 0x3a },
277 { 0x59, 0x88 }, { 0x5a, 0x88 },
278 { 0x5b, 0x44 }, { 0x5c, 0x67 },
279 { 0x5d, 0x49 }, { 0x5e, 0x0e },
280 { 0x6c, 0x0a }, { 0x6d, 0x55 },
281 { 0x6e, 0x11 }, { 0x6f, 0x9f }, /* "9e for advance AWB" */
282 { 0x6a, 0x40 }, { REG_BLUE
, 0x40 },
284 { REG_COM8
, COM8_FASTAEC
|COM8_AECSTEP
|COM8_BFILT
|COM8_AGC
|COM8_AEC
|COM8_AWB
},
286 /* Matrix coefficients */
287 { 0x4f, 0x80 }, { 0x50, 0x80 },
288 { 0x51, 0 }, { 0x52, 0x22 },
289 { 0x53, 0x5e }, { 0x54, 0x80 },
292 { REG_COM16
, COM16_AWBGAIN
}, { REG_EDGE
, 0 },
293 { 0x75, 0x05 }, { 0x76, 0xe1 },
294 { 0x4c, 0 }, { 0x77, 0x01 },
295 { REG_COM13
, 0xc3 }, { 0x4b, 0x09 },
296 { 0xc9, 0x60 }, { REG_COM16
, 0x38 },
299 { 0x34, 0x11 }, { REG_COM11
, COM11_EXP
|COM11_HZAUTO
},
300 { 0xa4, 0x88 }, { 0x96, 0 },
301 { 0x97, 0x30 }, { 0x98, 0x20 },
302 { 0x99, 0x30 }, { 0x9a, 0x84 },
303 { 0x9b, 0x29 }, { 0x9c, 0x03 },
304 { 0x9d, 0x4c }, { 0x9e, 0x3f },
307 /* Extra-weird stuff. Some sort of multiplexor register */
308 { 0x79, 0x01 }, { 0xc8, 0xf0 },
309 { 0x79, 0x0f }, { 0xc8, 0x00 },
310 { 0x79, 0x10 }, { 0xc8, 0x7e },
311 { 0x79, 0x0a }, { 0xc8, 0x80 },
312 { 0x79, 0x0b }, { 0xc8, 0x01 },
313 { 0x79, 0x0c }, { 0xc8, 0x0f },
314 { 0x79, 0x0d }, { 0xc8, 0x20 },
315 { 0x79, 0x09 }, { 0xc8, 0x80 },
316 { 0x79, 0x02 }, { 0xc8, 0xc0 },
317 { 0x79, 0x03 }, { 0xc8, 0x40 },
318 { 0x79, 0x05 }, { 0xc8, 0x30 },
321 { 0xff, 0xff }, /* END MARKER */
326 * Here we'll try to encapsulate the changes for just the output
329 * RGB656 and YUV422 come from OV; RGB444 is homebrewed.
331 * IMPORTANT RULE: the first entry must be for COM7, see ov7670_s_fmt for why.
335 static struct regval_list ov7670_fmt_yuv422
[] = {
336 { REG_COM7
, 0x0 }, /* Selects YUV mode */
337 { REG_RGB444
, 0 }, /* No RGB444 please */
339 { REG_COM15
, COM15_R00FF
},
340 { REG_COM9
, 0x18 }, /* 4x gain ceiling; 0x8 is reserved bit */
341 { 0x4f, 0x80 }, /* "matrix coefficient 1" */
342 { 0x50, 0x80 }, /* "matrix coefficient 2" */
343 { 0x51, 0 }, /* vb */
344 { 0x52, 0x22 }, /* "matrix coefficient 4" */
345 { 0x53, 0x5e }, /* "matrix coefficient 5" */
346 { 0x54, 0x80 }, /* "matrix coefficient 6" */
347 { REG_COM13
, COM13_GAMMA
|COM13_UVSAT
},
351 static struct regval_list ov7670_fmt_rgb565
[] = {
352 { REG_COM7
, COM7_RGB
}, /* Selects RGB mode */
353 { REG_RGB444
, 0 }, /* No RGB444 please */
355 { REG_COM15
, COM15_RGB565
},
356 { REG_COM9
, 0x38 }, /* 16x gain ceiling; 0x8 is reserved bit */
357 { 0x4f, 0xb3 }, /* "matrix coefficient 1" */
358 { 0x50, 0xb3 }, /* "matrix coefficient 2" */
359 { 0x51, 0 }, /* vb */
360 { 0x52, 0x3d }, /* "matrix coefficient 4" */
361 { 0x53, 0xa7 }, /* "matrix coefficient 5" */
362 { 0x54, 0xe4 }, /* "matrix coefficient 6" */
363 { REG_COM13
, COM13_GAMMA
|COM13_UVSAT
},
367 static struct regval_list ov7670_fmt_rgb444
[] = {
368 { REG_COM7
, COM7_RGB
}, /* Selects RGB mode */
369 { REG_RGB444
, R444_ENABLE
}, /* Enable xxxxrrrr ggggbbbb */
370 { REG_COM1
, 0x40 }, /* Magic reserved bit */
371 { REG_COM15
, COM15_R01FE
|COM15_RGB565
}, /* Data range needed? */
372 { REG_COM9
, 0x38 }, /* 16x gain ceiling; 0x8 is reserved bit */
373 { 0x4f, 0xb3 }, /* "matrix coefficient 1" */
374 { 0x50, 0xb3 }, /* "matrix coefficient 2" */
375 { 0x51, 0 }, /* vb */
376 { 0x52, 0x3d }, /* "matrix coefficient 4" */
377 { 0x53, 0xa7 }, /* "matrix coefficient 5" */
378 { 0x54, 0xe4 }, /* "matrix coefficient 6" */
379 { REG_COM13
, COM13_GAMMA
|COM13_UVSAT
|0x2 }, /* Magic rsvd bit */
387 * Low-level register I/O.
390 static int ov7670_read(struct i2c_client
*c
, unsigned char reg
,
391 unsigned char *value
)
395 ret
= i2c_smbus_read_byte_data(c
, reg
);
397 *value
= (unsigned char) ret
;
402 static int ov7670_write(struct i2c_client
*c
, unsigned char reg
,
405 return i2c_smbus_write_byte_data(c
, reg
, value
);
410 * Write a list of register settings; ff/ff stops the process.
412 static int ov7670_write_array(struct i2c_client
*c
, struct regval_list
*vals
)
414 while (vals
->reg_num
!= 0xff || vals
->value
!= 0xff) {
415 int ret
= ov7670_write(c
, vals
->reg_num
, vals
->value
);
425 * Stuff that knows about the sensor.
427 static void ov7670_reset(struct i2c_client
*client
)
429 ov7670_write(client
, REG_COM7
, COM7_RESET
);
434 static int ov7670_init(struct i2c_client
*client
)
436 return ov7670_write_array(client
, ov7670_default_regs
);
441 static int ov7670_detect(struct i2c_client
*client
)
446 ret
= ov7670_init(client
);
449 ret
= ov7670_read(client
, REG_MIDH
, &v
);
452 if (v
!= 0x7f) /* OV manuf. id. */
454 ret
= ov7670_read(client
, REG_MIDL
, &v
);
460 * OK, we know we have an OmniVision chip...but which one?
462 ret
= ov7670_read(client
, REG_PID
, &v
);
465 if (v
!= 0x76) /* PID + VER = 0x76 / 0x73 */
467 ret
= ov7670_read(client
, REG_VER
, &v
);
470 if (v
!= 0x73) /* PID + VER = 0x76 / 0x73 */
477 * Store information about the video data format. The color matrix
478 * is deeply tied into the format, so keep the relevant values here.
479 * The magic matrix nubmers come from OmniVision.
481 static struct ov7670_format_struct
{
484 struct regval_list
*regs
;
485 int cmatrix
[CMATRIX_LEN
];
486 } ov7670_formats
[] = {
488 .desc
= "YUYV 4:2:2",
489 .pixelformat
= V4L2_PIX_FMT_YUYV
,
490 .regs
= ov7670_fmt_yuv422
,
491 .cmatrix
= { 128, -128, 0, -34, -94, 128 },
495 .pixelformat
= V4L2_PIX_FMT_RGB444
,
496 .regs
= ov7670_fmt_rgb444
,
497 .cmatrix
= { 179, -179, 0, -61, -176, 228 },
501 .pixelformat
= V4L2_PIX_FMT_RGB565
,
502 .regs
= ov7670_fmt_rgb565
,
503 .cmatrix
= { 179, -179, 0, -61, -176, 228 },
506 #define N_OV7670_FMTS (sizeof(ov7670_formats)/sizeof(ov7670_formats[0]))
509 * All formats we support are 2 bytes/pixel.
511 #define BYTES_PER_PIXEL 2
514 * Then there is the issue of window sizes. Try to capture the info here.
518 * QCIF mode is done (by OV) in a very strange way - it actually looks like
519 * VGA with weird scaling options - they do *not* use the canned QCIF mode
520 * which is allegedly provided by the sensor. So here's the weird register
523 static struct regval_list ov7670_qcif_regs
[] = {
524 { REG_COM3
, COM3_SCALEEN
|COM3_DCWEN
},
525 { REG_COM3
, COM3_DCWEN
},
526 { REG_COM14
, COM14_DCWEN
| 0x01},
542 static struct ov7670_win_size
{
545 unsigned char com7_bit
;
546 int hstart
; /* Start/stop values for the camera. Note */
547 int hstop
; /* that they do not always make complete */
548 int vstart
; /* sense to humans, but evidently the sensor */
549 int vstop
; /* will do the right thing... */
550 struct regval_list
*regs
; /* Regs to tweak */
552 } ov7670_win_sizes
[] = {
556 .height
= VGA_HEIGHT
,
557 .com7_bit
= COM7_FMT_VGA
,
558 .hstart
= 158, /* These values from */
559 .hstop
= 14, /* Omnivision */
567 .height
= CIF_HEIGHT
,
568 .com7_bit
= COM7_FMT_CIF
,
569 .hstart
= 170, /* Empirically determined */
578 .height
= QVGA_HEIGHT
,
579 .com7_bit
= COM7_FMT_QVGA
,
580 .hstart
= 164, /* Empirically determined */
589 .height
= QCIF_HEIGHT
,
590 .com7_bit
= COM7_FMT_VGA
, /* see comment above */
591 .hstart
= 456, /* Empirically determined */
595 .regs
= ov7670_qcif_regs
,
599 #define N_WIN_SIZES (sizeof(ov7670_win_sizes)/sizeof(ov7670_win_sizes[0]))
603 * Store a set of start/stop values into the camera.
605 static int ov7670_set_hw(struct i2c_client
*client
, int hstart
, int hstop
,
606 int vstart
, int vstop
)
611 * Horizontal: 11 bits, top 8 live in hstart and hstop. Bottom 3 of
612 * hstart are in href[2:0], bottom 3 of hstop in href[5:3]. There is
613 * a mystery "edge offset" value in the top two bits of href.
615 ret
= ov7670_write(client
, REG_HSTART
, (hstart
>> 3) & 0xff);
616 ret
+= ov7670_write(client
, REG_HSTOP
, (hstop
>> 3) & 0xff);
617 ret
+= ov7670_read(client
, REG_HREF
, &v
);
618 v
= (v
& 0xc0) | ((hstop
& 0x7) << 3) | (hstart
& 0x7);
620 ret
+= ov7670_write(client
, REG_HREF
, v
);
622 * Vertical: similar arrangement, but only 10 bits.
624 ret
+= ov7670_write(client
, REG_VSTART
, (vstart
>> 2) & 0xff);
625 ret
+= ov7670_write(client
, REG_VSTOP
, (vstop
>> 2) & 0xff);
626 ret
+= ov7670_read(client
, REG_VREF
, &v
);
627 v
= (v
& 0xf0) | ((vstop
& 0x3) << 2) | (vstart
& 0x3);
629 ret
+= ov7670_write(client
, REG_VREF
, v
);
634 static int ov7670_enum_fmt(struct i2c_client
*c
, struct v4l2_fmtdesc
*fmt
)
636 struct ov7670_format_struct
*ofmt
;
638 if (fmt
->index
>= N_OV7670_FMTS
)
641 ofmt
= ov7670_formats
+ fmt
->index
;
643 strcpy(fmt
->description
, ofmt
->desc
);
644 fmt
->pixelformat
= ofmt
->pixelformat
;
649 static int ov7670_try_fmt(struct i2c_client
*c
, struct v4l2_format
*fmt
,
650 struct ov7670_format_struct
**ret_fmt
,
651 struct ov7670_win_size
**ret_wsize
)
654 struct ov7670_win_size
*wsize
;
655 struct v4l2_pix_format
*pix
= &fmt
->fmt
.pix
;
657 for (index
= 0; index
< N_OV7670_FMTS
; index
++)
658 if (ov7670_formats
[index
].pixelformat
== pix
->pixelformat
)
660 if (index
>= N_OV7670_FMTS
)
663 *ret_fmt
= ov7670_formats
+ index
;
665 * Fields: the OV devices claim to be progressive.
667 if (pix
->field
== V4L2_FIELD_ANY
)
668 pix
->field
= V4L2_FIELD_NONE
;
669 else if (pix
->field
!= V4L2_FIELD_NONE
)
672 * Round requested image size down to the nearest
673 * we support, but not below the smallest.
675 for (wsize
= ov7670_win_sizes
; wsize
< ov7670_win_sizes
+ N_WIN_SIZES
;
677 if (pix
->width
>= wsize
->width
&& pix
->height
>= wsize
->height
)
679 if (wsize
>= ov7670_win_sizes
+ N_WIN_SIZES
)
680 wsize
--; /* Take the smallest one */
681 if (ret_wsize
!= NULL
)
684 * Note the size we'll actually handle.
686 pix
->width
= wsize
->width
;
687 pix
->height
= wsize
->height
;
688 pix
->bytesperline
= pix
->width
*BYTES_PER_PIXEL
;
689 pix
->sizeimage
= pix
->height
*pix
->bytesperline
;
696 static int ov7670_s_fmt(struct i2c_client
*c
, struct v4l2_format
*fmt
)
699 struct ov7670_format_struct
*ovfmt
;
700 struct ov7670_win_size
*wsize
;
701 struct ov7670_info
*info
= i2c_get_clientdata(c
);
704 ret
= ov7670_try_fmt(c
, fmt
, &ovfmt
, &wsize
);
708 * COM7 is a pain in the ass, it doesn't like to be read then
709 * quickly written afterward. But we have everything we need
710 * to set it absolutely here, as long as the format-specific
711 * register sets list it first.
713 com7
= ovfmt
->regs
[0].value
;
714 com7
|= wsize
->com7_bit
;
715 ov7670_write(c
, REG_COM7
, com7
);
717 * Now write the rest of the array. Also store start/stops
719 ov7670_write_array(c
, ovfmt
->regs
+ 1);
720 ov7670_set_hw(c
, wsize
->hstart
, wsize
->hstop
, wsize
->vstart
,
724 ret
= ov7670_write_array(c
, wsize
->regs
);
730 * Implement G/S_PARM. There is a "high quality" mode we could try
731 * to do someday; for now, we just do the frame rate tweak.
733 static int ov7670_g_parm(struct i2c_client
*c
, struct v4l2_streamparm
*parms
)
735 struct v4l2_captureparm
*cp
= &parms
->parm
.capture
;
739 if (parms
->type
!= V4L2_BUF_TYPE_VIDEO_CAPTURE
)
741 ret
= ov7670_read(c
, REG_CLKRC
, &clkrc
);
744 memset(cp
, 0, sizeof(struct v4l2_captureparm
));
745 cp
->capability
= V4L2_CAP_TIMEPERFRAME
;
746 cp
->timeperframe
.numerator
= 1;
747 cp
->timeperframe
.denominator
= OV7670_FRAME_RATE
;
748 if ((clkrc
& CLK_EXT
) == 0 && (clkrc
& CLK_SCALE
) > 1)
749 cp
->timeperframe
.denominator
/= (clkrc
& CLK_SCALE
);
753 static int ov7670_s_parm(struct i2c_client
*c
, struct v4l2_streamparm
*parms
)
755 struct v4l2_captureparm
*cp
= &parms
->parm
.capture
;
756 struct v4l2_fract
*tpf
= &cp
->timeperframe
;
760 if (parms
->type
!= V4L2_BUF_TYPE_VIDEO_CAPTURE
)
762 if (cp
->extendedmode
!= 0)
765 * CLKRC has a reserved bit, so let's preserve it.
767 ret
= ov7670_read(c
, REG_CLKRC
, &clkrc
);
770 if (tpf
->numerator
== 0 || tpf
->denominator
== 0)
771 div
= 1; /* Reset to full rate */
773 div
= (tpf
->numerator
*OV7670_FRAME_RATE
)/tpf
->denominator
;
776 else if (div
> CLK_SCALE
)
778 clkrc
= (clkrc
& 0x80) | div
;
780 tpf
->denominator
= OV7670_FRAME_RATE
/div
;
781 return ov7670_write(c
, REG_CLKRC
, clkrc
);
787 * Code for dealing with controls.
794 static int ov7670_store_cmatrix(struct i2c_client
*client
,
795 int matrix
[CMATRIX_LEN
])
798 unsigned char signbits
;
801 * Weird crap seems to exist in the upper part of
802 * the sign bits register, so let's preserve it.
804 ret
= ov7670_read(client
, REG_CMATRIX_SIGN
, &signbits
);
807 for (i
= 0; i
< CMATRIX_LEN
; i
++) {
811 signbits
|= (1 << i
);
812 if (matrix
[i
] < -255)
815 raw
= (-1 * matrix
[i
]) & 0xff;
821 raw
= matrix
[i
] & 0xff;
823 ret
+= ov7670_write(client
, REG_CMATRIX_BASE
+ i
, raw
);
825 ret
+= ov7670_write(client
, REG_CMATRIX_SIGN
, signbits
);
831 * Hue also requires messing with the color matrix. It also requires
832 * trig functions, which tend not to be well supported in the kernel.
833 * So here is a simple table of sine values, 0-90 degrees, in steps
834 * of five degrees. Values are multiplied by 1000.
836 * The following naive approximate trig functions require an argument
837 * carefully limited to -180 <= theta <= 180.
840 static const int ov7670_sin_table
[] = {
841 0, 87, 173, 258, 342, 422,
842 499, 573, 642, 707, 766, 819,
843 866, 906, 939, 965, 984, 996,
847 static int ov7670_sine(int theta
)
857 sine
= ov7670_sin_table
[theta
/SIN_STEP
];
860 sine
= 1000 - ov7670_sin_table
[theta
/SIN_STEP
];
865 static int ov7670_cosine(int theta
)
870 else if (theta
< -180)
872 return ov7670_sine(theta
);
878 static void ov7670_calc_cmatrix(struct ov7670_info
*info
,
879 int matrix
[CMATRIX_LEN
])
883 * Apply the current saturation setting first.
885 for (i
= 0; i
< CMATRIX_LEN
; i
++)
886 matrix
[i
] = (info
->fmt
->cmatrix
[i
]*info
->sat
) >> 7;
888 * Then, if need be, rotate the hue value.
890 if (info
->hue
!= 0) {
891 int sinth
, costh
, tmpmatrix
[CMATRIX_LEN
];
893 memcpy(tmpmatrix
, matrix
, CMATRIX_LEN
*sizeof(int));
894 sinth
= ov7670_sine(info
->hue
);
895 costh
= ov7670_cosine(info
->hue
);
897 matrix
[0] = (matrix
[3]*sinth
+ matrix
[0]*costh
)/1000;
898 matrix
[1] = (matrix
[4]*sinth
+ matrix
[1]*costh
)/1000;
899 matrix
[2] = (matrix
[5]*sinth
+ matrix
[2]*costh
)/1000;
900 matrix
[3] = (matrix
[3]*costh
- matrix
[0]*sinth
)/1000;
901 matrix
[4] = (matrix
[4]*costh
- matrix
[1]*sinth
)/1000;
902 matrix
[5] = (matrix
[5]*costh
- matrix
[2]*sinth
)/1000;
908 static int ov7670_t_sat(struct i2c_client
*client
, int value
)
910 struct ov7670_info
*info
= i2c_get_clientdata(client
);
911 int matrix
[CMATRIX_LEN
];
915 ov7670_calc_cmatrix(info
, matrix
);
916 ret
= ov7670_store_cmatrix(client
, matrix
);
920 static int ov7670_q_sat(struct i2c_client
*client
, __s32
*value
)
922 struct ov7670_info
*info
= i2c_get_clientdata(client
);
928 static int ov7670_t_hue(struct i2c_client
*client
, int value
)
930 struct ov7670_info
*info
= i2c_get_clientdata(client
);
931 int matrix
[CMATRIX_LEN
];
934 if (value
< -180 || value
> 180)
937 ov7670_calc_cmatrix(info
, matrix
);
938 ret
= ov7670_store_cmatrix(client
, matrix
);
943 static int ov7670_q_hue(struct i2c_client
*client
, __s32
*value
)
945 struct ov7670_info
*info
= i2c_get_clientdata(client
);
953 * Some weird registers seem to store values in a sign/magnitude format!
955 static unsigned char ov7670_sm_to_abs(unsigned char v
)
960 return 128 - (v
& 0x7f);
964 static unsigned char ov7670_abs_to_sm(unsigned char v
)
969 return (128 - v
) | 0x80;
972 static int ov7670_t_brightness(struct i2c_client
*client
, int value
)
974 unsigned char com8
, v
;
977 ov7670_read(client
, REG_COM8
, &com8
);
979 ov7670_write(client
, REG_COM8
, com8
);
980 v
= ov7670_abs_to_sm(value
);
981 ret
= ov7670_write(client
, REG_BRIGHT
, v
);
985 static int ov7670_q_brightness(struct i2c_client
*client
, __s32
*value
)
988 int ret
= ov7670_read(client
, REG_BRIGHT
, &v
);
990 *value
= ov7670_sm_to_abs(v
);
994 static int ov7670_t_contrast(struct i2c_client
*client
, int value
)
996 return ov7670_write(client
, REG_CONTRAS
, (unsigned char) value
);
999 static int ov7670_q_contrast(struct i2c_client
*client
, __s32
*value
)
1002 int ret
= ov7670_read(client
, REG_CONTRAS
, &v
);
1008 static int ov7670_q_hflip(struct i2c_client
*client
, __s32
*value
)
1013 ret
= ov7670_read(client
, REG_MVFP
, &v
);
1014 *value
= (v
& MVFP_MIRROR
) == MVFP_MIRROR
;
1019 static int ov7670_t_hflip(struct i2c_client
*client
, int value
)
1024 ret
= ov7670_read(client
, REG_MVFP
, &v
);
1029 msleep(10); /* FIXME */
1030 ret
+= ov7670_write(client
, REG_MVFP
, v
);
1036 static int ov7670_q_vflip(struct i2c_client
*client
, __s32
*value
)
1041 ret
= ov7670_read(client
, REG_MVFP
, &v
);
1042 *value
= (v
& MVFP_FLIP
) == MVFP_FLIP
;
1047 static int ov7670_t_vflip(struct i2c_client
*client
, int value
)
1052 ret
= ov7670_read(client
, REG_MVFP
, &v
);
1057 msleep(10); /* FIXME */
1058 ret
+= ov7670_write(client
, REG_MVFP
, v
);
1063 static struct ov7670_control
{
1064 struct v4l2_queryctrl qc
;
1065 int (*query
)(struct i2c_client
*c
, __s32
*value
);
1066 int (*tweak
)(struct i2c_client
*c
, int value
);
1067 } ov7670_controls
[] =
1071 .id
= V4L2_CID_BRIGHTNESS
,
1072 .type
= V4L2_CTRL_TYPE_INTEGER
,
1073 .name
= "Brightness",
1077 .default_value
= 0x80,
1078 .flags
= V4L2_CTRL_FLAG_SLIDER
1080 .tweak
= ov7670_t_brightness
,
1081 .query
= ov7670_q_brightness
,
1085 .id
= V4L2_CID_CONTRAST
,
1086 .type
= V4L2_CTRL_TYPE_INTEGER
,
1091 .default_value
= 0x40, /* XXX ov7670 spec */
1092 .flags
= V4L2_CTRL_FLAG_SLIDER
1094 .tweak
= ov7670_t_contrast
,
1095 .query
= ov7670_q_contrast
,
1099 .id
= V4L2_CID_SATURATION
,
1100 .type
= V4L2_CTRL_TYPE_INTEGER
,
1101 .name
= "Saturation",
1105 .default_value
= 0x80,
1106 .flags
= V4L2_CTRL_FLAG_SLIDER
1108 .tweak
= ov7670_t_sat
,
1109 .query
= ov7670_q_sat
,
1114 .type
= V4L2_CTRL_TYPE_INTEGER
,
1120 .flags
= V4L2_CTRL_FLAG_SLIDER
1122 .tweak
= ov7670_t_hue
,
1123 .query
= ov7670_q_hue
,
1127 .id
= V4L2_CID_VFLIP
,
1128 .type
= V4L2_CTRL_TYPE_BOOLEAN
,
1129 .name
= "Vertical flip",
1135 .tweak
= ov7670_t_vflip
,
1136 .query
= ov7670_q_vflip
,
1140 .id
= V4L2_CID_HFLIP
,
1141 .type
= V4L2_CTRL_TYPE_BOOLEAN
,
1142 .name
= "Horizontal mirror",
1148 .tweak
= ov7670_t_hflip
,
1149 .query
= ov7670_q_hflip
,
1152 #define N_CONTROLS (sizeof(ov7670_controls)/sizeof(ov7670_controls[0]))
1154 static struct ov7670_control
*ov7670_find_control(__u32 id
)
1158 for (i
= 0; i
< N_CONTROLS
; i
++)
1159 if (ov7670_controls
[i
].qc
.id
== id
)
1160 return ov7670_controls
+ i
;
1165 static int ov7670_queryctrl(struct i2c_client
*client
,
1166 struct v4l2_queryctrl
*qc
)
1168 struct ov7670_control
*ctrl
= ov7670_find_control(qc
->id
);
1176 static int ov7670_g_ctrl(struct i2c_client
*client
, struct v4l2_control
*ctrl
)
1178 struct ov7670_control
*octrl
= ov7670_find_control(ctrl
->id
);
1183 ret
= octrl
->query(client
, &ctrl
->value
);
1189 static int ov7670_s_ctrl(struct i2c_client
*client
, struct v4l2_control
*ctrl
)
1191 struct ov7670_control
*octrl
= ov7670_find_control(ctrl
->id
);
1196 ret
= octrl
->tweak(client
, ctrl
->value
);
1210 static struct i2c_driver ov7670_driver
;
1212 static int ov7670_attach(struct i2c_adapter
*adapter
)
1215 struct i2c_client
*client
;
1216 struct ov7670_info
*info
;
1219 * For now: only deal with adapters we recognize.
1221 if (adapter
->id
!= I2C_HW_SMBUS_CAFE
)
1224 client
= kzalloc(sizeof (struct i2c_client
), GFP_KERNEL
);
1227 client
->adapter
= adapter
;
1228 client
->addr
= OV7670_I2C_ADDR
;
1229 client
->driver
= &ov7670_driver
,
1230 strcpy(client
->name
, "OV7670");
1232 * Set up our info structure.
1234 info
= kzalloc(sizeof (struct ov7670_info
), GFP_KERNEL
);
1239 info
->fmt
= &ov7670_formats
[0];
1240 info
->sat
= 128; /* Review this */
1241 i2c_set_clientdata(client
, info
);
1244 * Make sure it's an ov7670
1246 ret
= ov7670_detect(client
);
1249 i2c_attach_client(client
);
1260 static int ov7670_detach(struct i2c_client
*client
)
1262 i2c_detach_client(client
);
1263 kfree(i2c_get_clientdata(client
));
1269 static int ov7670_command(struct i2c_client
*client
, unsigned int cmd
,
1273 case VIDIOC_INT_G_CHIP_IDENT
:
1274 * (enum v4l2_chip_ident
*) arg
= V4L2_IDENT_OV7670
;
1277 case VIDIOC_INT_RESET
:
1278 ov7670_reset(client
);
1281 case VIDIOC_INT_INIT
:
1282 return ov7670_init(client
);
1284 case VIDIOC_ENUM_FMT
:
1285 return ov7670_enum_fmt(client
, (struct v4l2_fmtdesc
*) arg
);
1286 case VIDIOC_TRY_FMT
:
1287 return ov7670_try_fmt(client
, (struct v4l2_format
*) arg
, NULL
, NULL
);
1289 return ov7670_s_fmt(client
, (struct v4l2_format
*) arg
);
1290 case VIDIOC_QUERYCTRL
:
1291 return ov7670_queryctrl(client
, (struct v4l2_queryctrl
*) arg
);
1293 return ov7670_s_ctrl(client
, (struct v4l2_control
*) arg
);
1295 return ov7670_g_ctrl(client
, (struct v4l2_control
*) arg
);
1297 return ov7670_s_parm(client
, (struct v4l2_streamparm
*) arg
);
1299 return ov7670_g_parm(client
, (struct v4l2_streamparm
*) arg
);
1306 static struct i2c_driver ov7670_driver
= {
1310 .id
= I2C_DRIVERID_OV7670
,
1311 .class = I2C_CLASS_CAM_DIGITAL
,
1312 .attach_adapter
= ov7670_attach
,
1313 .detach_client
= ov7670_detach
,
1314 .command
= ov7670_command
,
1319 * Module initialization
1321 static int __init
ov7670_mod_init(void)
1323 printk(KERN_NOTICE
"OmniVision ov7670 sensor driver, at your service\n");
1324 return i2c_add_driver(&ov7670_driver
);
1327 static void __exit
ov7670_mod_exit(void)
1329 i2c_del_driver(&ov7670_driver
);
1332 module_init(ov7670_mod_init
);
1333 module_exit(ov7670_mod_exit
);