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 * Copyright 2006-7 Jonathan Corbet <corbet@lwn.net>
10 * This file may be distributed under the terms of the GNU General
11 * Public License, version 2.
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/moduleparam.h>
16 #include <linux/slab.h>
17 #include <linux/delay.h>
18 #include <linux/videodev.h>
19 #include <media/v4l2-common.h>
20 #include <media/v4l2-chip-ident.h>
21 #include <linux/i2c.h>
24 MODULE_AUTHOR("Jonathan Corbet <corbet@lwn.net>");
25 MODULE_DESCRIPTION("A low-level driver for OmniVision ov7670 sensors");
26 MODULE_LICENSE("GPL");
29 * Basic window sizes. These probably belong somewhere more globally
33 #define VGA_HEIGHT 480
34 #define QVGA_WIDTH 320
35 #define QVGA_HEIGHT 240
37 #define CIF_HEIGHT 288
38 #define QCIF_WIDTH 176
39 #define QCIF_HEIGHT 144
42 * Our nominal (default) frame rate.
44 #define OV7670_FRAME_RATE 30
47 * The 7670 sits on i2c with ID 0x42
49 #define OV7670_I2C_ADDR 0x42
52 #define REG_GAIN 0x00 /* Gain lower 8 bits (rest in vref) */
53 #define REG_BLUE 0x01 /* blue gain */
54 #define REG_RED 0x02 /* red gain */
55 #define REG_VREF 0x03 /* Pieces of GAIN, VSTART, VSTOP */
56 #define REG_COM1 0x04 /* Control 1 */
57 #define COM1_CCIR656 0x40 /* CCIR656 enable */
58 #define REG_BAVE 0x05 /* U/B Average level */
59 #define REG_GbAVE 0x06 /* Y/Gb Average level */
60 #define REG_AECHH 0x07 /* AEC MS 5 bits */
61 #define REG_RAVE 0x08 /* V/R Average level */
62 #define REG_COM2 0x09 /* Control 2 */
63 #define COM2_SSLEEP 0x10 /* Soft sleep mode */
64 #define REG_PID 0x0a /* Product ID MSB */
65 #define REG_VER 0x0b /* Product ID LSB */
66 #define REG_COM3 0x0c /* Control 3 */
67 #define COM3_SWAP 0x40 /* Byte swap */
68 #define COM3_SCALEEN 0x08 /* Enable scaling */
69 #define COM3_DCWEN 0x04 /* Enable downsamp/crop/window */
70 #define REG_COM4 0x0d /* Control 4 */
71 #define REG_COM5 0x0e /* All "reserved" */
72 #define REG_COM6 0x0f /* Control 6 */
73 #define REG_AECH 0x10 /* More bits of AEC value */
74 #define REG_CLKRC 0x11 /* Clocl control */
75 #define CLK_EXT 0x40 /* Use external clock directly */
76 #define CLK_SCALE 0x3f /* Mask for internal clock scale */
77 #define REG_COM7 0x12 /* Control 7 */
78 #define COM7_RESET 0x80 /* Register reset */
79 #define COM7_FMT_MASK 0x38
80 #define COM7_FMT_VGA 0x00
81 #define COM7_FMT_CIF 0x20 /* CIF format */
82 #define COM7_FMT_QVGA 0x10 /* QVGA format */
83 #define COM7_FMT_QCIF 0x08 /* QCIF format */
84 #define COM7_RGB 0x04 /* bits 0 and 2 - RGB format */
85 #define COM7_YUV 0x00 /* YUV */
86 #define COM7_BAYER 0x01 /* Bayer format */
87 #define COM7_PBAYER 0x05 /* "Processed bayer" */
88 #define REG_COM8 0x13 /* Control 8 */
89 #define COM8_FASTAEC 0x80 /* Enable fast AGC/AEC */
90 #define COM8_AECSTEP 0x40 /* Unlimited AEC step size */
91 #define COM8_BFILT 0x20 /* Band filter enable */
92 #define COM8_AGC 0x04 /* Auto gain enable */
93 #define COM8_AWB 0x02 /* White balance enable */
94 #define COM8_AEC 0x01 /* Auto exposure enable */
95 #define REG_COM9 0x14 /* Control 9 - gain ceiling */
96 #define REG_COM10 0x15 /* Control 10 */
97 #define COM10_HSYNC 0x40 /* HSYNC instead of HREF */
98 #define COM10_PCLK_HB 0x20 /* Suppress PCLK on horiz blank */
99 #define COM10_HREF_REV 0x08 /* Reverse HREF */
100 #define COM10_VS_LEAD 0x04 /* VSYNC on clock leading edge */
101 #define COM10_VS_NEG 0x02 /* VSYNC negative */
102 #define COM10_HS_NEG 0x01 /* HSYNC negative */
103 #define REG_HSTART 0x17 /* Horiz start high bits */
104 #define REG_HSTOP 0x18 /* Horiz stop high bits */
105 #define REG_VSTART 0x19 /* Vert start high bits */
106 #define REG_VSTOP 0x1a /* Vert stop high bits */
107 #define REG_PSHFT 0x1b /* Pixel delay after HREF */
108 #define REG_MIDH 0x1c /* Manuf. ID high */
109 #define REG_MIDL 0x1d /* Manuf. ID low */
110 #define REG_MVFP 0x1e /* Mirror / vflip */
111 #define MVFP_MIRROR 0x20 /* Mirror image */
112 #define MVFP_FLIP 0x10 /* Vertical flip */
114 #define REG_AEW 0x24 /* AGC upper limit */
115 #define REG_AEB 0x25 /* AGC lower limit */
116 #define REG_VPT 0x26 /* AGC/AEC fast mode op region */
117 #define REG_HSYST 0x30 /* HSYNC rising edge delay */
118 #define REG_HSYEN 0x31 /* HSYNC falling edge delay */
119 #define REG_HREF 0x32 /* HREF pieces */
120 #define REG_TSLB 0x3a /* lots of stuff */
121 #define TSLB_YLAST 0x04 /* UYVY or VYUY - see com13 */
122 #define REG_COM11 0x3b /* Control 11 */
123 #define COM11_NIGHT 0x80 /* NIght mode enable */
124 #define COM11_NMFR 0x60 /* Two bit NM frame rate */
125 #define COM11_HZAUTO 0x10 /* Auto detect 50/60 Hz */
126 #define COM11_50HZ 0x08 /* Manual 50Hz select */
127 #define COM11_EXP 0x02
128 #define REG_COM12 0x3c /* Control 12 */
129 #define COM12_HREF 0x80 /* HREF always */
130 #define REG_COM13 0x3d /* Control 13 */
131 #define COM13_GAMMA 0x80 /* Gamma enable */
132 #define COM13_UVSAT 0x40 /* UV saturation auto adjustment */
133 #define COM13_UVSWAP 0x01 /* V before U - w/TSLB */
134 #define REG_COM14 0x3e /* Control 14 */
135 #define COM14_DCWEN 0x10 /* DCW/PCLK-scale enable */
136 #define REG_EDGE 0x3f /* Edge enhancement factor */
137 #define REG_COM15 0x40 /* Control 15 */
138 #define COM15_R10F0 0x00 /* Data range 10 to F0 */
139 #define COM15_R01FE 0x80 /* 01 to FE */
140 #define COM15_R00FF 0xc0 /* 00 to FF */
141 #define COM15_RGB565 0x10 /* RGB565 output */
142 #define COM15_RGB555 0x30 /* RGB555 output */
143 #define REG_COM16 0x41 /* Control 16 */
144 #define COM16_AWBGAIN 0x08 /* AWB gain enable */
145 #define REG_COM17 0x42 /* Control 17 */
146 #define COM17_AECWIN 0xc0 /* AEC window - must match COM4 */
147 #define COM17_CBAR 0x08 /* DSP Color bar */
150 * This matrix defines how the colors are generated, must be
151 * tweaked to adjust hue and saturation.
153 * Order: v-red, v-green, v-blue, u-red, u-green, u-blue
155 * They are nine-bit signed quantities, with the sign bit
156 * stored in 0x58. Sign for v-red is bit 0, and up from there.
158 #define REG_CMATRIX_BASE 0x4f
159 #define CMATRIX_LEN 6
160 #define REG_CMATRIX_SIGN 0x58
163 #define REG_BRIGHT 0x55 /* Brightness */
164 #define REG_CONTRAS 0x56 /* Contrast control */
166 #define REG_GFIX 0x69 /* Fix gain control */
168 #define REG_REG76 0x76 /* OV's name */
169 #define R76_BLKPCOR 0x80 /* Black pixel correction enable */
170 #define R76_WHTPCOR 0x40 /* White pixel correction enable */
172 #define REG_RGB444 0x8c /* RGB 444 control */
173 #define R444_ENABLE 0x02 /* Turn on RGB444, overrides 5x5 */
174 #define R444_RGBX 0x01 /* Empty nibble at end */
176 #define REG_HAECC1 0x9f /* Hist AEC/AGC control 1 */
177 #define REG_HAECC2 0xa0 /* Hist AEC/AGC control 2 */
179 #define REG_BD50MAX 0xa5 /* 50hz banding step limit */
180 #define REG_HAECC3 0xa6 /* Hist AEC/AGC control 3 */
181 #define REG_HAECC4 0xa7 /* Hist AEC/AGC control 4 */
182 #define REG_HAECC5 0xa8 /* Hist AEC/AGC control 5 */
183 #define REG_HAECC6 0xa9 /* Hist AEC/AGC control 6 */
184 #define REG_HAECC7 0xaa /* Hist AEC/AGC control 7 */
185 #define REG_BD60MAX 0xab /* 60hz banding step limit */
189 * Information we maintain about a known sensor.
191 struct ov7670_format_struct; /* coming later */
193 struct ov7670_format_struct *fmt; /* Current format */
194 unsigned char sat; /* Saturation value */
195 int hue; /* Hue value */
202 * The default register settings, as obtained from OmniVision. There
203 * is really no making sense of most of these - lots of "reserved" values
206 * These settings give VGA YUYV.
210 unsigned char reg_num;
214 static struct regval_list ov7670_default_regs[] = {
215 { REG_COM7, COM7_RESET },
217 * Clock scale: 3 = 15fps
221 { REG_CLKRC, 0x1 }, /* OV: clock scale (30 fps) */
222 { REG_TSLB, 0x04 }, /* OV */
223 { REG_COM7, 0 }, /* VGA */
225 * Set the hardware window. These values from OV don't entirely
226 * make sense - hstop is less than hstart. But they work...
228 { REG_HSTART, 0x13 }, { REG_HSTOP, 0x01 },
229 { REG_HREF, 0xb6 }, { REG_VSTART, 0x02 },
230 { REG_VSTOP, 0x7a }, { REG_VREF, 0x0a },
232 { REG_COM3, 0 }, { REG_COM14, 0 },
233 /* Mystery scaling numbers */
234 { 0x70, 0x3a }, { 0x71, 0x35 },
235 { 0x72, 0x11 }, { 0x73, 0xf0 },
236 { 0xa2, 0x02 }, { REG_COM10, 0x0 },
238 /* Gamma curve values */
239 { 0x7a, 0x20 }, { 0x7b, 0x10 },
240 { 0x7c, 0x1e }, { 0x7d, 0x35 },
241 { 0x7e, 0x5a }, { 0x7f, 0x69 },
242 { 0x80, 0x76 }, { 0x81, 0x80 },
243 { 0x82, 0x88 }, { 0x83, 0x8f },
244 { 0x84, 0x96 }, { 0x85, 0xa3 },
245 { 0x86, 0xaf }, { 0x87, 0xc4 },
246 { 0x88, 0xd7 }, { 0x89, 0xe8 },
248 /* AGC and AEC parameters. Note we start by disabling those features,
249 then turn them only after tweaking the values. */
250 { REG_COM8, COM8_FASTAEC | COM8_AECSTEP | COM8_BFILT },
251 { REG_GAIN, 0 }, { REG_AECH, 0 },
252 { REG_COM4, 0x40 }, /* magic reserved bit */
253 { REG_COM9, 0x18 }, /* 4x gain + magic rsvd bit */
254 { REG_BD50MAX, 0x05 }, { REG_BD60MAX, 0x07 },
255 { REG_AEW, 0x95 }, { REG_AEB, 0x33 },
256 { REG_VPT, 0xe3 }, { REG_HAECC1, 0x78 },
257 { REG_HAECC2, 0x68 }, { 0xa1, 0x03 }, /* magic */
258 { REG_HAECC3, 0xd8 }, { REG_HAECC4, 0xd8 },
259 { REG_HAECC5, 0xf0 }, { REG_HAECC6, 0x90 },
260 { REG_HAECC7, 0x94 },
261 { REG_COM8, COM8_FASTAEC|COM8_AECSTEP|COM8_BFILT|COM8_AGC|COM8_AEC },
263 /* Almost all of these are magic "reserved" values. */
264 { REG_COM5, 0x61 }, { REG_COM6, 0x4b },
265 { 0x16, 0x02 }, { REG_MVFP, 0x07 },
266 { 0x21, 0x02 }, { 0x22, 0x91 },
267 { 0x29, 0x07 }, { 0x33, 0x0b },
268 { 0x35, 0x0b }, { 0x37, 0x1d },
269 { 0x38, 0x71 }, { 0x39, 0x2a },
270 { REG_COM12, 0x78 }, { 0x4d, 0x40 },
271 { 0x4e, 0x20 }, { REG_GFIX, 0 },
272 { 0x6b, 0x4a }, { 0x74, 0x10 },
273 { 0x8d, 0x4f }, { 0x8e, 0 },
274 { 0x8f, 0 }, { 0x90, 0 },
275 { 0x91, 0 }, { 0x96, 0 },
276 { 0x9a, 0 }, { 0xb0, 0x84 },
277 { 0xb1, 0x0c }, { 0xb2, 0x0e },
278 { 0xb3, 0x82 }, { 0xb8, 0x0a },
280 /* More reserved magic, some of which tweaks white balance */
281 { 0x43, 0x0a }, { 0x44, 0xf0 },
282 { 0x45, 0x34 }, { 0x46, 0x58 },
283 { 0x47, 0x28 }, { 0x48, 0x3a },
284 { 0x59, 0x88 }, { 0x5a, 0x88 },
285 { 0x5b, 0x44 }, { 0x5c, 0x67 },
286 { 0x5d, 0x49 }, { 0x5e, 0x0e },
287 { 0x6c, 0x0a }, { 0x6d, 0x55 },
288 { 0x6e, 0x11 }, { 0x6f, 0x9f }, /* "9e for advance AWB" */
289 { 0x6a, 0x40 }, { REG_BLUE, 0x40 },
291 { REG_COM8, COM8_FASTAEC|COM8_AECSTEP|COM8_BFILT|COM8_AGC|COM8_AEC|COM8_AWB },
293 /* Matrix coefficients */
294 { 0x4f, 0x80 }, { 0x50, 0x80 },
295 { 0x51, 0 }, { 0x52, 0x22 },
296 { 0x53, 0x5e }, { 0x54, 0x80 },
299 { REG_COM16, COM16_AWBGAIN }, { REG_EDGE, 0 },
300 { 0x75, 0x05 }, { 0x76, 0xe1 },
301 { 0x4c, 0 }, { 0x77, 0x01 },
302 { REG_COM13, 0xc3 }, { 0x4b, 0x09 },
303 { 0xc9, 0x60 }, { REG_COM16, 0x38 },
306 { 0x34, 0x11 }, { REG_COM11, COM11_EXP|COM11_HZAUTO },
307 { 0xa4, 0x88 }, { 0x96, 0 },
308 { 0x97, 0x30 }, { 0x98, 0x20 },
309 { 0x99, 0x30 }, { 0x9a, 0x84 },
310 { 0x9b, 0x29 }, { 0x9c, 0x03 },
311 { 0x9d, 0x4c }, { 0x9e, 0x3f },
314 /* Extra-weird stuff. Some sort of multiplexor register */
315 { 0x79, 0x01 }, { 0xc8, 0xf0 },
316 { 0x79, 0x0f }, { 0xc8, 0x00 },
317 { 0x79, 0x10 }, { 0xc8, 0x7e },
318 { 0x79, 0x0a }, { 0xc8, 0x80 },
319 { 0x79, 0x0b }, { 0xc8, 0x01 },
320 { 0x79, 0x0c }, { 0xc8, 0x0f },
321 { 0x79, 0x0d }, { 0xc8, 0x20 },
322 { 0x79, 0x09 }, { 0xc8, 0x80 },
323 { 0x79, 0x02 }, { 0xc8, 0xc0 },
324 { 0x79, 0x03 }, { 0xc8, 0x40 },
325 { 0x79, 0x05 }, { 0xc8, 0x30 },
328 { 0xff, 0xff }, /* END MARKER */
333 * Here we'll try to encapsulate the changes for just the output
336 * RGB656 and YUV422 come from OV; RGB444 is homebrewed.
338 * IMPORTANT RULE: the first entry must be for COM7, see ov7670_s_fmt for why.
342 static struct regval_list ov7670_fmt_yuv422[] = {
343 { REG_COM7, 0x0 }, /* Selects YUV mode */
344 { REG_RGB444, 0 }, /* No RGB444 please */
346 { REG_COM15, COM15_R00FF },
347 { REG_COM9, 0x18 }, /* 4x gain ceiling; 0x8 is reserved bit */
348 { 0x4f, 0x80 }, /* "matrix coefficient 1" */
349 { 0x50, 0x80 }, /* "matrix coefficient 2" */
350 { 0x51, 0 }, /* vb */
351 { 0x52, 0x22 }, /* "matrix coefficient 4" */
352 { 0x53, 0x5e }, /* "matrix coefficient 5" */
353 { 0x54, 0x80 }, /* "matrix coefficient 6" */
354 { REG_COM13, COM13_GAMMA|COM13_UVSAT },
358 static struct regval_list ov7670_fmt_rgb565[] = {
359 { REG_COM7, COM7_RGB }, /* Selects RGB mode */
360 { REG_RGB444, 0 }, /* No RGB444 please */
362 { REG_COM15, COM15_RGB565 },
363 { REG_COM9, 0x38 }, /* 16x gain ceiling; 0x8 is reserved bit */
364 { 0x4f, 0xb3 }, /* "matrix coefficient 1" */
365 { 0x50, 0xb3 }, /* "matrix coefficient 2" */
366 { 0x51, 0 }, /* vb */
367 { 0x52, 0x3d }, /* "matrix coefficient 4" */
368 { 0x53, 0xa7 }, /* "matrix coefficient 5" */
369 { 0x54, 0xe4 }, /* "matrix coefficient 6" */
370 { REG_COM13, COM13_GAMMA|COM13_UVSAT },
374 static struct regval_list ov7670_fmt_rgb444[] = {
375 { REG_COM7, COM7_RGB }, /* Selects RGB mode */
376 { REG_RGB444, R444_ENABLE }, /* Enable xxxxrrrr ggggbbbb */
377 { REG_COM1, 0x40 }, /* Magic reserved bit */
378 { REG_COM15, COM15_R01FE|COM15_RGB565 }, /* Data range needed? */
379 { REG_COM9, 0x38 }, /* 16x gain ceiling; 0x8 is reserved bit */
380 { 0x4f, 0xb3 }, /* "matrix coefficient 1" */
381 { 0x50, 0xb3 }, /* "matrix coefficient 2" */
382 { 0x51, 0 }, /* vb */
383 { 0x52, 0x3d }, /* "matrix coefficient 4" */
384 { 0x53, 0xa7 }, /* "matrix coefficient 5" */
385 { 0x54, 0xe4 }, /* "matrix coefficient 6" */
386 { REG_COM13, COM13_GAMMA|COM13_UVSAT|0x2 }, /* Magic rsvd bit */
390 static struct regval_list ov7670_fmt_raw[] = {
391 { REG_COM7, COM7_BAYER },
392 { REG_COM13, 0x08 }, /* No gamma, magic rsvd bit */
393 { REG_COM16, 0x3d }, /* Edge enhancement, denoise */
394 { REG_REG76, 0xe1 }, /* Pix correction, magic rsvd */
401 * Low-level register I/O.
404 static int ov7670_read(struct i2c_client *c, unsigned char reg,
405 unsigned char *value)
409 ret = i2c_smbus_read_byte_data(c, reg);
411 *value = (unsigned char) ret;
416 static int ov7670_write(struct i2c_client *c, unsigned char reg,
419 return i2c_smbus_write_byte_data(c, reg, value);
424 * Write a list of register settings; ff/ff stops the process.
426 static int ov7670_write_array(struct i2c_client *c, struct regval_list *vals)
428 while (vals->reg_num != 0xff || vals->value != 0xff) {
429 int ret = ov7670_write(c, vals->reg_num, vals->value);
439 * Stuff that knows about the sensor.
441 static void ov7670_reset(struct i2c_client *client)
443 ov7670_write(client, REG_COM7, COM7_RESET);
448 static int ov7670_init(struct i2c_client *client)
450 return ov7670_write_array(client, ov7670_default_regs);
455 static int ov7670_detect(struct i2c_client *client)
460 ret = ov7670_init(client);
463 ret = ov7670_read(client, REG_MIDH, &v);
466 if (v != 0x7f) /* OV manuf. id. */
468 ret = ov7670_read(client, REG_MIDL, &v);
474 * OK, we know we have an OmniVision chip...but which one?
476 ret = ov7670_read(client, REG_PID, &v);
479 if (v != 0x76) /* PID + VER = 0x76 / 0x73 */
481 ret = ov7670_read(client, REG_VER, &v);
484 if (v != 0x73) /* PID + VER = 0x76 / 0x73 */
491 * Store information about the video data format. The color matrix
492 * is deeply tied into the format, so keep the relevant values here.
493 * The magic matrix nubmers come from OmniVision.
495 static struct ov7670_format_struct {
498 struct regval_list *regs;
499 int cmatrix[CMATRIX_LEN];
500 int bpp; /* Bytes per pixel */
501 } ov7670_formats[] = {
503 .desc = "YUYV 4:2:2",
504 .pixelformat = V4L2_PIX_FMT_YUYV,
505 .regs = ov7670_fmt_yuv422,
506 .cmatrix = { 128, -128, 0, -34, -94, 128 },
511 .pixelformat = V4L2_PIX_FMT_RGB444,
512 .regs = ov7670_fmt_rgb444,
513 .cmatrix = { 179, -179, 0, -61, -176, 228 },
518 .pixelformat = V4L2_PIX_FMT_RGB565,
519 .regs = ov7670_fmt_rgb565,
520 .cmatrix = { 179, -179, 0, -61, -176, 228 },
524 .desc = "Raw RGB Bayer",
525 .pixelformat = V4L2_PIX_FMT_SBGGR8,
526 .regs = ov7670_fmt_raw,
527 .cmatrix = { 0, 0, 0, 0, 0, 0 },
531 #define N_OV7670_FMTS ARRAY_SIZE(ov7670_formats)
535 * Then there is the issue of window sizes. Try to capture the info here.
539 * QCIF mode is done (by OV) in a very strange way - it actually looks like
540 * VGA with weird scaling options - they do *not* use the canned QCIF mode
541 * which is allegedly provided by the sensor. So here's the weird register
544 static struct regval_list ov7670_qcif_regs[] = {
545 { REG_COM3, COM3_SCALEEN|COM3_DCWEN },
546 { REG_COM3, COM3_DCWEN },
547 { REG_COM14, COM14_DCWEN | 0x01},
563 static struct ov7670_win_size {
566 unsigned char com7_bit;
567 int hstart; /* Start/stop values for the camera. Note */
568 int hstop; /* that they do not always make complete */
569 int vstart; /* sense to humans, but evidently the sensor */
570 int vstop; /* will do the right thing... */
571 struct regval_list *regs; /* Regs to tweak */
573 } ov7670_win_sizes[] = {
577 .height = VGA_HEIGHT,
578 .com7_bit = COM7_FMT_VGA,
579 .hstart = 158, /* These values from */
580 .hstop = 14, /* Omnivision */
588 .height = CIF_HEIGHT,
589 .com7_bit = COM7_FMT_CIF,
590 .hstart = 170, /* Empirically determined */
599 .height = QVGA_HEIGHT,
600 .com7_bit = COM7_FMT_QVGA,
601 .hstart = 164, /* Empirically determined */
610 .height = QCIF_HEIGHT,
611 .com7_bit = COM7_FMT_VGA, /* see comment above */
612 .hstart = 456, /* Empirically determined */
616 .regs = ov7670_qcif_regs,
620 #define N_WIN_SIZES (ARRAY_SIZE(ov7670_win_sizes))
624 * Store a set of start/stop values into the camera.
626 static int ov7670_set_hw(struct i2c_client *client, int hstart, int hstop,
627 int vstart, int vstop)
632 * Horizontal: 11 bits, top 8 live in hstart and hstop. Bottom 3 of
633 * hstart are in href[2:0], bottom 3 of hstop in href[5:3]. There is
634 * a mystery "edge offset" value in the top two bits of href.
636 ret = ov7670_write(client, REG_HSTART, (hstart >> 3) & 0xff);
637 ret += ov7670_write(client, REG_HSTOP, (hstop >> 3) & 0xff);
638 ret += ov7670_read(client, REG_HREF, &v);
639 v = (v & 0xc0) | ((hstop & 0x7) << 3) | (hstart & 0x7);
641 ret += ov7670_write(client, REG_HREF, v);
643 * Vertical: similar arrangement, but only 10 bits.
645 ret += ov7670_write(client, REG_VSTART, (vstart >> 2) & 0xff);
646 ret += ov7670_write(client, REG_VSTOP, (vstop >> 2) & 0xff);
647 ret += ov7670_read(client, REG_VREF, &v);
648 v = (v & 0xf0) | ((vstop & 0x3) << 2) | (vstart & 0x3);
650 ret += ov7670_write(client, REG_VREF, v);
655 static int ov7670_enum_fmt(struct i2c_client *c, struct v4l2_fmtdesc *fmt)
657 struct ov7670_format_struct *ofmt;
659 if (fmt->index >= N_OV7670_FMTS)
662 ofmt = ov7670_formats + fmt->index;
664 strcpy(fmt->description, ofmt->desc);
665 fmt->pixelformat = ofmt->pixelformat;
670 static int ov7670_try_fmt(struct i2c_client *c, struct v4l2_format *fmt,
671 struct ov7670_format_struct **ret_fmt,
672 struct ov7670_win_size **ret_wsize)
675 struct ov7670_win_size *wsize;
676 struct v4l2_pix_format *pix = &fmt->fmt.pix;
678 for (index = 0; index < N_OV7670_FMTS; index++)
679 if (ov7670_formats[index].pixelformat == pix->pixelformat)
681 if (index >= N_OV7670_FMTS)
684 *ret_fmt = ov7670_formats + index;
686 * Fields: the OV devices claim to be progressive.
688 if (pix->field == V4L2_FIELD_ANY)
689 pix->field = V4L2_FIELD_NONE;
690 else if (pix->field != V4L2_FIELD_NONE)
693 * Round requested image size down to the nearest
694 * we support, but not below the smallest.
696 for (wsize = ov7670_win_sizes; wsize < ov7670_win_sizes + N_WIN_SIZES;
698 if (pix->width >= wsize->width && pix->height >= wsize->height)
700 if (wsize >= ov7670_win_sizes + N_WIN_SIZES)
701 wsize--; /* Take the smallest one */
702 if (ret_wsize != NULL)
705 * Note the size we'll actually handle.
707 pix->width = wsize->width;
708 pix->height = wsize->height;
709 pix->bytesperline = pix->width*ov7670_formats[index].bpp;
710 pix->sizeimage = pix->height*pix->bytesperline;
717 static int ov7670_s_fmt(struct i2c_client *c, struct v4l2_format *fmt)
720 struct ov7670_format_struct *ovfmt;
721 struct ov7670_win_size *wsize;
722 struct ov7670_info *info = i2c_get_clientdata(c);
723 unsigned char com7, clkrc;
725 ret = ov7670_try_fmt(c, fmt, &ovfmt, &wsize);
729 * HACK: if we're running rgb565 we need to grab then rewrite
730 * CLKRC. If we're *not*, however, then rewriting clkrc hoses
733 if (fmt->fmt.pix.pixelformat == V4L2_PIX_FMT_RGB565) {
734 ret = ov7670_read(c, REG_CLKRC, &clkrc);
739 * COM7 is a pain in the ass, it doesn't like to be read then
740 * quickly written afterward. But we have everything we need
741 * to set it absolutely here, as long as the format-specific
742 * register sets list it first.
744 com7 = ovfmt->regs[0].value;
745 com7 |= wsize->com7_bit;
746 ov7670_write(c, REG_COM7, com7);
748 * Now write the rest of the array. Also store start/stops
750 ov7670_write_array(c, ovfmt->regs + 1);
751 ov7670_set_hw(c, wsize->hstart, wsize->hstop, wsize->vstart,
755 ret = ov7670_write_array(c, wsize->regs);
758 if (fmt->fmt.pix.pixelformat == V4L2_PIX_FMT_RGB565 && ret == 0)
759 ret = ov7670_write(c, REG_CLKRC, clkrc);
764 * Implement G/S_PARM. There is a "high quality" mode we could try
765 * to do someday; for now, we just do the frame rate tweak.
767 static int ov7670_g_parm(struct i2c_client *c, struct v4l2_streamparm *parms)
769 struct v4l2_captureparm *cp = &parms->parm.capture;
773 if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
775 ret = ov7670_read(c, REG_CLKRC, &clkrc);
778 memset(cp, 0, sizeof(struct v4l2_captureparm));
779 cp->capability = V4L2_CAP_TIMEPERFRAME;
780 cp->timeperframe.numerator = 1;
781 cp->timeperframe.denominator = OV7670_FRAME_RATE;
782 if ((clkrc & CLK_EXT) == 0 && (clkrc & CLK_SCALE) > 1)
783 cp->timeperframe.denominator /= (clkrc & CLK_SCALE);
787 static int ov7670_s_parm(struct i2c_client *c, struct v4l2_streamparm *parms)
789 struct v4l2_captureparm *cp = &parms->parm.capture;
790 struct v4l2_fract *tpf = &cp->timeperframe;
794 if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
796 if (cp->extendedmode != 0)
799 * CLKRC has a reserved bit, so let's preserve it.
801 ret = ov7670_read(c, REG_CLKRC, &clkrc);
804 if (tpf->numerator == 0 || tpf->denominator == 0)
805 div = 1; /* Reset to full rate */
807 div = (tpf->numerator*OV7670_FRAME_RATE)/tpf->denominator;
810 else if (div > CLK_SCALE)
812 clkrc = (clkrc & 0x80) | div;
814 tpf->denominator = OV7670_FRAME_RATE/div;
815 return ov7670_write(c, REG_CLKRC, clkrc);
821 * Code for dealing with controls.
828 static int ov7670_store_cmatrix(struct i2c_client *client,
829 int matrix[CMATRIX_LEN])
832 unsigned char signbits;
835 * Weird crap seems to exist in the upper part of
836 * the sign bits register, so let's preserve it.
838 ret = ov7670_read(client, REG_CMATRIX_SIGN, &signbits);
841 for (i = 0; i < CMATRIX_LEN; i++) {
845 signbits |= (1 << i);
846 if (matrix[i] < -255)
849 raw = (-1 * matrix[i]) & 0xff;
855 raw = matrix[i] & 0xff;
857 ret += ov7670_write(client, REG_CMATRIX_BASE + i, raw);
859 ret += ov7670_write(client, REG_CMATRIX_SIGN, signbits);
865 * Hue also requires messing with the color matrix. It also requires
866 * trig functions, which tend not to be well supported in the kernel.
867 * So here is a simple table of sine values, 0-90 degrees, in steps
868 * of five degrees. Values are multiplied by 1000.
870 * The following naive approximate trig functions require an argument
871 * carefully limited to -180 <= theta <= 180.
874 static const int ov7670_sin_table[] = {
875 0, 87, 173, 258, 342, 422,
876 499, 573, 642, 707, 766, 819,
877 866, 906, 939, 965, 984, 996,
881 static int ov7670_sine(int theta)
891 sine = ov7670_sin_table[theta/SIN_STEP];
894 sine = 1000 - ov7670_sin_table[theta/SIN_STEP];
899 static int ov7670_cosine(int theta)
904 else if (theta < -180)
906 return ov7670_sine(theta);
912 static void ov7670_calc_cmatrix(struct ov7670_info *info,
913 int matrix[CMATRIX_LEN])
917 * Apply the current saturation setting first.
919 for (i = 0; i < CMATRIX_LEN; i++)
920 matrix[i] = (info->fmt->cmatrix[i]*info->sat) >> 7;
922 * Then, if need be, rotate the hue value.
924 if (info->hue != 0) {
925 int sinth, costh, tmpmatrix[CMATRIX_LEN];
927 memcpy(tmpmatrix, matrix, CMATRIX_LEN*sizeof(int));
928 sinth = ov7670_sine(info->hue);
929 costh = ov7670_cosine(info->hue);
931 matrix[0] = (matrix[3]*sinth + matrix[0]*costh)/1000;
932 matrix[1] = (matrix[4]*sinth + matrix[1]*costh)/1000;
933 matrix[2] = (matrix[5]*sinth + matrix[2]*costh)/1000;
934 matrix[3] = (matrix[3]*costh - matrix[0]*sinth)/1000;
935 matrix[4] = (matrix[4]*costh - matrix[1]*sinth)/1000;
936 matrix[5] = (matrix[5]*costh - matrix[2]*sinth)/1000;
942 static int ov7670_t_sat(struct i2c_client *client, int value)
944 struct ov7670_info *info = i2c_get_clientdata(client);
945 int matrix[CMATRIX_LEN];
949 ov7670_calc_cmatrix(info, matrix);
950 ret = ov7670_store_cmatrix(client, matrix);
954 static int ov7670_q_sat(struct i2c_client *client, __s32 *value)
956 struct ov7670_info *info = i2c_get_clientdata(client);
962 static int ov7670_t_hue(struct i2c_client *client, int value)
964 struct ov7670_info *info = i2c_get_clientdata(client);
965 int matrix[CMATRIX_LEN];
968 if (value < -180 || value > 180)
971 ov7670_calc_cmatrix(info, matrix);
972 ret = ov7670_store_cmatrix(client, matrix);
977 static int ov7670_q_hue(struct i2c_client *client, __s32 *value)
979 struct ov7670_info *info = i2c_get_clientdata(client);
987 * Some weird registers seem to store values in a sign/magnitude format!
989 static unsigned char ov7670_sm_to_abs(unsigned char v)
994 return 128 - (v & 0x7f);
998 static unsigned char ov7670_abs_to_sm(unsigned char v)
1003 return (128 - v) | 0x80;
1006 static int ov7670_t_brightness(struct i2c_client *client, int value)
1008 unsigned char com8, v;
1011 ov7670_read(client, REG_COM8, &com8);
1013 ov7670_write(client, REG_COM8, com8);
1014 v = ov7670_abs_to_sm(value);
1015 ret = ov7670_write(client, REG_BRIGHT, v);
1019 static int ov7670_q_brightness(struct i2c_client *client, __s32 *value)
1022 int ret = ov7670_read(client, REG_BRIGHT, &v);
1024 *value = ov7670_sm_to_abs(v);
1028 static int ov7670_t_contrast(struct i2c_client *client, int value)
1030 return ov7670_write(client, REG_CONTRAS, (unsigned char) value);
1033 static int ov7670_q_contrast(struct i2c_client *client, __s32 *value)
1036 int ret = ov7670_read(client, REG_CONTRAS, &v);
1042 static int ov7670_q_hflip(struct i2c_client *client, __s32 *value)
1047 ret = ov7670_read(client, REG_MVFP, &v);
1048 *value = (v & MVFP_MIRROR) == MVFP_MIRROR;
1053 static int ov7670_t_hflip(struct i2c_client *client, int value)
1058 ret = ov7670_read(client, REG_MVFP, &v);
1063 msleep(10); /* FIXME */
1064 ret += ov7670_write(client, REG_MVFP, v);
1070 static int ov7670_q_vflip(struct i2c_client *client, __s32 *value)
1075 ret = ov7670_read(client, REG_MVFP, &v);
1076 *value = (v & MVFP_FLIP) == MVFP_FLIP;
1081 static int ov7670_t_vflip(struct i2c_client *client, int value)
1086 ret = ov7670_read(client, REG_MVFP, &v);
1091 msleep(10); /* FIXME */
1092 ret += ov7670_write(client, REG_MVFP, v);
1097 static struct ov7670_control {
1098 struct v4l2_queryctrl qc;
1099 int (*query)(struct i2c_client *c, __s32 *value);
1100 int (*tweak)(struct i2c_client *c, int value);
1101 } ov7670_controls[] =
1105 .id = V4L2_CID_BRIGHTNESS,
1106 .type = V4L2_CTRL_TYPE_INTEGER,
1107 .name = "Brightness",
1111 .default_value = 0x80,
1112 .flags = V4L2_CTRL_FLAG_SLIDER
1114 .tweak = ov7670_t_brightness,
1115 .query = ov7670_q_brightness,
1119 .id = V4L2_CID_CONTRAST,
1120 .type = V4L2_CTRL_TYPE_INTEGER,
1125 .default_value = 0x40, /* XXX ov7670 spec */
1126 .flags = V4L2_CTRL_FLAG_SLIDER
1128 .tweak = ov7670_t_contrast,
1129 .query = ov7670_q_contrast,
1133 .id = V4L2_CID_SATURATION,
1134 .type = V4L2_CTRL_TYPE_INTEGER,
1135 .name = "Saturation",
1139 .default_value = 0x80,
1140 .flags = V4L2_CTRL_FLAG_SLIDER
1142 .tweak = ov7670_t_sat,
1143 .query = ov7670_q_sat,
1148 .type = V4L2_CTRL_TYPE_INTEGER,
1154 .flags = V4L2_CTRL_FLAG_SLIDER
1156 .tweak = ov7670_t_hue,
1157 .query = ov7670_q_hue,
1161 .id = V4L2_CID_VFLIP,
1162 .type = V4L2_CTRL_TYPE_BOOLEAN,
1163 .name = "Vertical flip",
1169 .tweak = ov7670_t_vflip,
1170 .query = ov7670_q_vflip,
1174 .id = V4L2_CID_HFLIP,
1175 .type = V4L2_CTRL_TYPE_BOOLEAN,
1176 .name = "Horizontal mirror",
1182 .tweak = ov7670_t_hflip,
1183 .query = ov7670_q_hflip,
1186 #define N_CONTROLS (ARRAY_SIZE(ov7670_controls))
1188 static struct ov7670_control *ov7670_find_control(__u32 id)
1192 for (i = 0; i < N_CONTROLS; i++)
1193 if (ov7670_controls[i].qc.id == id)
1194 return ov7670_controls + i;
1199 static int ov7670_queryctrl(struct i2c_client *client,
1200 struct v4l2_queryctrl *qc)
1202 struct ov7670_control *ctrl = ov7670_find_control(qc->id);
1210 static int ov7670_g_ctrl(struct i2c_client *client, struct v4l2_control *ctrl)
1212 struct ov7670_control *octrl = ov7670_find_control(ctrl->id);
1217 ret = octrl->query(client, &ctrl->value);
1223 static int ov7670_s_ctrl(struct i2c_client *client, struct v4l2_control *ctrl)
1225 struct ov7670_control *octrl = ov7670_find_control(ctrl->id);
1230 ret = octrl->tweak(client, ctrl->value);
1244 static struct i2c_driver ov7670_driver;
1246 static int ov7670_attach(struct i2c_adapter *adapter)
1249 struct i2c_client *client;
1250 struct ov7670_info *info;
1253 * For now: only deal with adapters we recognize.
1255 if (adapter->id != I2C_HW_SMBUS_CAFE)
1258 client = kzalloc(sizeof (struct i2c_client), GFP_KERNEL);
1261 client->adapter = adapter;
1262 client->addr = OV7670_I2C_ADDR;
1263 client->driver = &ov7670_driver,
1264 strcpy(client->name, "OV7670");
1266 * Set up our info structure.
1268 info = kzalloc(sizeof (struct ov7670_info), GFP_KERNEL);
1273 info->fmt = &ov7670_formats[0];
1274 info->sat = 128; /* Review this */
1275 i2c_set_clientdata(client, info);
1278 * Make sure it's an ov7670
1280 ret = ov7670_detect(client);
1283 ret = i2c_attach_client(client);
1296 static int ov7670_detach(struct i2c_client *client)
1298 i2c_detach_client(client);
1299 kfree(i2c_get_clientdata(client));
1305 static int ov7670_command(struct i2c_client *client, unsigned int cmd,
1309 case VIDIOC_G_CHIP_IDENT:
1310 return v4l2_chip_ident_i2c_client(client, arg, V4L2_IDENT_OV7670, 0);
1312 case VIDIOC_INT_RESET:
1313 ov7670_reset(client);
1316 case VIDIOC_INT_INIT:
1317 return ov7670_init(client);
1319 case VIDIOC_ENUM_FMT:
1320 return ov7670_enum_fmt(client, (struct v4l2_fmtdesc *) arg);
1321 case VIDIOC_TRY_FMT:
1322 return ov7670_try_fmt(client, (struct v4l2_format *) arg, NULL, NULL);
1324 return ov7670_s_fmt(client, (struct v4l2_format *) arg);
1325 case VIDIOC_QUERYCTRL:
1326 return ov7670_queryctrl(client, (struct v4l2_queryctrl *) arg);
1328 return ov7670_s_ctrl(client, (struct v4l2_control *) arg);
1330 return ov7670_g_ctrl(client, (struct v4l2_control *) arg);
1332 return ov7670_s_parm(client, (struct v4l2_streamparm *) arg);
1334 return ov7670_g_parm(client, (struct v4l2_streamparm *) arg);
1341 static struct i2c_driver ov7670_driver = {
1345 .id = I2C_DRIVERID_OV7670,
1346 .class = I2C_CLASS_CAM_DIGITAL,
1347 .attach_adapter = ov7670_attach,
1348 .detach_client = ov7670_detach,
1349 .command = ov7670_command,
1354 * Module initialization
1356 static int __init ov7670_mod_init(void)
1358 printk(KERN_NOTICE "OmniVision ov7670 sensor driver, at your service\n");
1359 return i2c_add_driver(&ov7670_driver);
1362 static void __exit ov7670_mod_exit(void)
1364 i2c_del_driver(&ov7670_driver);
1367 module_init(ov7670_mod_init);
1368 module_exit(ov7670_mod_exit);