xref: /openbmc/linux/drivers/media/i2c/ov7670.c (revision f35e839a)
1 /*
2  * A V4L2 driver for OmniVision OV7670 cameras.
3  *
4  * Copyright 2006 One Laptop Per Child Association, Inc.  Written
5  * by Jonathan Corbet with substantial inspiration from Mark
6  * McClelland's ovcamchip code.
7  *
8  * Copyright 2006-7 Jonathan Corbet <corbet@lwn.net>
9  *
10  * This file may be distributed under the terms of the GNU General
11  * Public License, version 2.
12  */
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/i2c.h>
17 #include <linux/delay.h>
18 #include <linux/videodev2.h>
19 #include <media/v4l2-device.h>
20 #include <media/v4l2-chip-ident.h>
21 #include <media/v4l2-ctrls.h>
22 #include <media/v4l2-mediabus.h>
23 #include <media/ov7670.h>
24 
25 MODULE_AUTHOR("Jonathan Corbet <corbet@lwn.net>");
26 MODULE_DESCRIPTION("A low-level driver for OmniVision ov7670 sensors");
27 MODULE_LICENSE("GPL");
28 
29 static bool debug;
30 module_param(debug, bool, 0644);
31 MODULE_PARM_DESC(debug, "Debug level (0-1)");
32 
33 /*
34  * Basic window sizes.  These probably belong somewhere more globally
35  * useful.
36  */
37 #define VGA_WIDTH	640
38 #define VGA_HEIGHT	480
39 #define QVGA_WIDTH	320
40 #define QVGA_HEIGHT	240
41 #define CIF_WIDTH	352
42 #define CIF_HEIGHT	288
43 #define QCIF_WIDTH	176
44 #define	QCIF_HEIGHT	144
45 
46 /*
47  * The 7670 sits on i2c with ID 0x42
48  */
49 #define OV7670_I2C_ADDR 0x42
50 
51 #define PLL_FACTOR	4
52 
53 /* Registers */
54 #define REG_GAIN	0x00	/* Gain lower 8 bits (rest in vref) */
55 #define REG_BLUE	0x01	/* blue gain */
56 #define REG_RED		0x02	/* red gain */
57 #define REG_VREF	0x03	/* Pieces of GAIN, VSTART, VSTOP */
58 #define REG_COM1	0x04	/* Control 1 */
59 #define  COM1_CCIR656	  0x40  /* CCIR656 enable */
60 #define REG_BAVE	0x05	/* U/B Average level */
61 #define REG_GbAVE	0x06	/* Y/Gb Average level */
62 #define REG_AECHH	0x07	/* AEC MS 5 bits */
63 #define REG_RAVE	0x08	/* V/R Average level */
64 #define REG_COM2	0x09	/* Control 2 */
65 #define  COM2_SSLEEP	  0x10	/* Soft sleep mode */
66 #define REG_PID		0x0a	/* Product ID MSB */
67 #define REG_VER		0x0b	/* Product ID LSB */
68 #define REG_COM3	0x0c	/* Control 3 */
69 #define  COM3_SWAP	  0x40	  /* Byte swap */
70 #define  COM3_SCALEEN	  0x08	  /* Enable scaling */
71 #define  COM3_DCWEN	  0x04	  /* Enable downsamp/crop/window */
72 #define REG_COM4	0x0d	/* Control 4 */
73 #define REG_COM5	0x0e	/* All "reserved" */
74 #define REG_COM6	0x0f	/* Control 6 */
75 #define REG_AECH	0x10	/* More bits of AEC value */
76 #define REG_CLKRC	0x11	/* Clocl control */
77 #define   CLK_EXT	  0x40	  /* Use external clock directly */
78 #define   CLK_SCALE	  0x3f	  /* Mask for internal clock scale */
79 #define REG_COM7	0x12	/* Control 7 */
80 #define   COM7_RESET	  0x80	  /* Register reset */
81 #define   COM7_FMT_MASK	  0x38
82 #define   COM7_FMT_VGA	  0x00
83 #define	  COM7_FMT_CIF	  0x20	  /* CIF format */
84 #define   COM7_FMT_QVGA	  0x10	  /* QVGA format */
85 #define   COM7_FMT_QCIF	  0x08	  /* QCIF format */
86 #define	  COM7_RGB	  0x04	  /* bits 0 and 2 - RGB format */
87 #define	  COM7_YUV	  0x00	  /* YUV */
88 #define	  COM7_BAYER	  0x01	  /* Bayer format */
89 #define	  COM7_PBAYER	  0x05	  /* "Processed bayer" */
90 #define REG_COM8	0x13	/* Control 8 */
91 #define   COM8_FASTAEC	  0x80	  /* Enable fast AGC/AEC */
92 #define   COM8_AECSTEP	  0x40	  /* Unlimited AEC step size */
93 #define   COM8_BFILT	  0x20	  /* Band filter enable */
94 #define   COM8_AGC	  0x04	  /* Auto gain enable */
95 #define   COM8_AWB	  0x02	  /* White balance enable */
96 #define   COM8_AEC	  0x01	  /* Auto exposure enable */
97 #define REG_COM9	0x14	/* Control 9  - gain ceiling */
98 #define REG_COM10	0x15	/* Control 10 */
99 #define   COM10_HSYNC	  0x40	  /* HSYNC instead of HREF */
100 #define   COM10_PCLK_HB	  0x20	  /* Suppress PCLK on horiz blank */
101 #define   COM10_HREF_REV  0x08	  /* Reverse HREF */
102 #define   COM10_VS_LEAD	  0x04	  /* VSYNC on clock leading edge */
103 #define   COM10_VS_NEG	  0x02	  /* VSYNC negative */
104 #define   COM10_HS_NEG	  0x01	  /* HSYNC negative */
105 #define REG_HSTART	0x17	/* Horiz start high bits */
106 #define REG_HSTOP	0x18	/* Horiz stop high bits */
107 #define REG_VSTART	0x19	/* Vert start high bits */
108 #define REG_VSTOP	0x1a	/* Vert stop high bits */
109 #define REG_PSHFT	0x1b	/* Pixel delay after HREF */
110 #define REG_MIDH	0x1c	/* Manuf. ID high */
111 #define REG_MIDL	0x1d	/* Manuf. ID low */
112 #define REG_MVFP	0x1e	/* Mirror / vflip */
113 #define   MVFP_MIRROR	  0x20	  /* Mirror image */
114 #define   MVFP_FLIP	  0x10	  /* Vertical flip */
115 
116 #define REG_AEW		0x24	/* AGC upper limit */
117 #define REG_AEB		0x25	/* AGC lower limit */
118 #define REG_VPT		0x26	/* AGC/AEC fast mode op region */
119 #define REG_HSYST	0x30	/* HSYNC rising edge delay */
120 #define REG_HSYEN	0x31	/* HSYNC falling edge delay */
121 #define REG_HREF	0x32	/* HREF pieces */
122 #define REG_TSLB	0x3a	/* lots of stuff */
123 #define   TSLB_YLAST	  0x04	  /* UYVY or VYUY - see com13 */
124 #define REG_COM11	0x3b	/* Control 11 */
125 #define   COM11_NIGHT	  0x80	  /* NIght mode enable */
126 #define   COM11_NMFR	  0x60	  /* Two bit NM frame rate */
127 #define   COM11_HZAUTO	  0x10	  /* Auto detect 50/60 Hz */
128 #define	  COM11_50HZ	  0x08	  /* Manual 50Hz select */
129 #define   COM11_EXP	  0x02
130 #define REG_COM12	0x3c	/* Control 12 */
131 #define   COM12_HREF	  0x80	  /* HREF always */
132 #define REG_COM13	0x3d	/* Control 13 */
133 #define   COM13_GAMMA	  0x80	  /* Gamma enable */
134 #define	  COM13_UVSAT	  0x40	  /* UV saturation auto adjustment */
135 #define   COM13_UVSWAP	  0x01	  /* V before U - w/TSLB */
136 #define REG_COM14	0x3e	/* Control 14 */
137 #define   COM14_DCWEN	  0x10	  /* DCW/PCLK-scale enable */
138 #define REG_EDGE	0x3f	/* Edge enhancement factor */
139 #define REG_COM15	0x40	/* Control 15 */
140 #define   COM15_R10F0	  0x00	  /* Data range 10 to F0 */
141 #define	  COM15_R01FE	  0x80	  /*            01 to FE */
142 #define   COM15_R00FF	  0xc0	  /*            00 to FF */
143 #define   COM15_RGB565	  0x10	  /* RGB565 output */
144 #define   COM15_RGB555	  0x30	  /* RGB555 output */
145 #define REG_COM16	0x41	/* Control 16 */
146 #define   COM16_AWBGAIN   0x08	  /* AWB gain enable */
147 #define REG_COM17	0x42	/* Control 17 */
148 #define   COM17_AECWIN	  0xc0	  /* AEC window - must match COM4 */
149 #define   COM17_CBAR	  0x08	  /* DSP Color bar */
150 
151 /*
152  * This matrix defines how the colors are generated, must be
153  * tweaked to adjust hue and saturation.
154  *
155  * Order: v-red, v-green, v-blue, u-red, u-green, u-blue
156  *
157  * They are nine-bit signed quantities, with the sign bit
158  * stored in 0x58.  Sign for v-red is bit 0, and up from there.
159  */
160 #define	REG_CMATRIX_BASE 0x4f
161 #define   CMATRIX_LEN 6
162 #define REG_CMATRIX_SIGN 0x58
163 
164 
165 #define REG_BRIGHT	0x55	/* Brightness */
166 #define REG_CONTRAS	0x56	/* Contrast control */
167 
168 #define REG_GFIX	0x69	/* Fix gain control */
169 
170 #define REG_DBLV	0x6b	/* PLL control an debugging */
171 #define   DBLV_BYPASS	  0x00	  /* Bypass PLL */
172 #define   DBLV_X4	  0x01	  /* clock x4 */
173 #define   DBLV_X6	  0x10	  /* clock x6 */
174 #define   DBLV_X8	  0x11	  /* clock x8 */
175 
176 #define REG_REG76	0x76	/* OV's name */
177 #define   R76_BLKPCOR	  0x80	  /* Black pixel correction enable */
178 #define   R76_WHTPCOR	  0x40	  /* White pixel correction enable */
179 
180 #define REG_RGB444	0x8c	/* RGB 444 control */
181 #define   R444_ENABLE	  0x02	  /* Turn on RGB444, overrides 5x5 */
182 #define   R444_RGBX	  0x01	  /* Empty nibble at end */
183 
184 #define REG_HAECC1	0x9f	/* Hist AEC/AGC control 1 */
185 #define REG_HAECC2	0xa0	/* Hist AEC/AGC control 2 */
186 
187 #define REG_BD50MAX	0xa5	/* 50hz banding step limit */
188 #define REG_HAECC3	0xa6	/* Hist AEC/AGC control 3 */
189 #define REG_HAECC4	0xa7	/* Hist AEC/AGC control 4 */
190 #define REG_HAECC5	0xa8	/* Hist AEC/AGC control 5 */
191 #define REG_HAECC6	0xa9	/* Hist AEC/AGC control 6 */
192 #define REG_HAECC7	0xaa	/* Hist AEC/AGC control 7 */
193 #define REG_BD60MAX	0xab	/* 60hz banding step limit */
194 
195 enum ov7670_model {
196 	MODEL_OV7670 = 0,
197 	MODEL_OV7675,
198 };
199 
200 struct ov7670_win_size {
201 	int	width;
202 	int	height;
203 	unsigned char com7_bit;
204 	int	hstart;		/* Start/stop values for the camera.  Note */
205 	int	hstop;		/* that they do not always make complete */
206 	int	vstart;		/* sense to humans, but evidently the sensor */
207 	int	vstop;		/* will do the right thing... */
208 	struct regval_list *regs; /* Regs to tweak */
209 };
210 
211 struct ov7670_devtype {
212 	/* formats supported for each model */
213 	struct ov7670_win_size *win_sizes;
214 	unsigned int n_win_sizes;
215 	/* callbacks for frame rate control */
216 	int (*set_framerate)(struct v4l2_subdev *, struct v4l2_fract *);
217 	void (*get_framerate)(struct v4l2_subdev *, struct v4l2_fract *);
218 };
219 
220 /*
221  * Information we maintain about a known sensor.
222  */
223 struct ov7670_format_struct;  /* coming later */
224 struct ov7670_info {
225 	struct v4l2_subdev sd;
226 	struct v4l2_ctrl_handler hdl;
227 	struct {
228 		/* gain cluster */
229 		struct v4l2_ctrl *auto_gain;
230 		struct v4l2_ctrl *gain;
231 	};
232 	struct {
233 		/* exposure cluster */
234 		struct v4l2_ctrl *auto_exposure;
235 		struct v4l2_ctrl *exposure;
236 	};
237 	struct {
238 		/* saturation/hue cluster */
239 		struct v4l2_ctrl *saturation;
240 		struct v4l2_ctrl *hue;
241 	};
242 	struct ov7670_format_struct *fmt;  /* Current format */
243 	int min_width;			/* Filter out smaller sizes */
244 	int min_height;			/* Filter out smaller sizes */
245 	int clock_speed;		/* External clock speed (MHz) */
246 	u8 clkrc;			/* Clock divider value */
247 	bool use_smbus;			/* Use smbus I/O instead of I2C */
248 	bool pll_bypass;
249 	bool pclk_hb_disable;
250 	const struct ov7670_devtype *devtype; /* Device specifics */
251 };
252 
253 static inline struct ov7670_info *to_state(struct v4l2_subdev *sd)
254 {
255 	return container_of(sd, struct ov7670_info, sd);
256 }
257 
258 static inline struct v4l2_subdev *to_sd(struct v4l2_ctrl *ctrl)
259 {
260 	return &container_of(ctrl->handler, struct ov7670_info, hdl)->sd;
261 }
262 
263 
264 
265 /*
266  * The default register settings, as obtained from OmniVision.  There
267  * is really no making sense of most of these - lots of "reserved" values
268  * and such.
269  *
270  * These settings give VGA YUYV.
271  */
272 
273 struct regval_list {
274 	unsigned char reg_num;
275 	unsigned char value;
276 };
277 
278 static struct regval_list ov7670_default_regs[] = {
279 	{ REG_COM7, COM7_RESET },
280 /*
281  * Clock scale: 3 = 15fps
282  *              2 = 20fps
283  *              1 = 30fps
284  */
285 	{ REG_CLKRC, 0x1 },	/* OV: clock scale (30 fps) */
286 	{ REG_TSLB,  0x04 },	/* OV */
287 	{ REG_COM7, 0 },	/* VGA */
288 	/*
289 	 * Set the hardware window.  These values from OV don't entirely
290 	 * make sense - hstop is less than hstart.  But they work...
291 	 */
292 	{ REG_HSTART, 0x13 },	{ REG_HSTOP, 0x01 },
293 	{ REG_HREF, 0xb6 },	{ REG_VSTART, 0x02 },
294 	{ REG_VSTOP, 0x7a },	{ REG_VREF, 0x0a },
295 
296 	{ REG_COM3, 0 },	{ REG_COM14, 0 },
297 	/* Mystery scaling numbers */
298 	{ 0x70, 0x3a },		{ 0x71, 0x35 },
299 	{ 0x72, 0x11 },		{ 0x73, 0xf0 },
300 	{ 0xa2, 0x02 },		{ REG_COM10, 0x0 },
301 
302 	/* Gamma curve values */
303 	{ 0x7a, 0x20 },		{ 0x7b, 0x10 },
304 	{ 0x7c, 0x1e },		{ 0x7d, 0x35 },
305 	{ 0x7e, 0x5a },		{ 0x7f, 0x69 },
306 	{ 0x80, 0x76 },		{ 0x81, 0x80 },
307 	{ 0x82, 0x88 },		{ 0x83, 0x8f },
308 	{ 0x84, 0x96 },		{ 0x85, 0xa3 },
309 	{ 0x86, 0xaf },		{ 0x87, 0xc4 },
310 	{ 0x88, 0xd7 },		{ 0x89, 0xe8 },
311 
312 	/* AGC and AEC parameters.  Note we start by disabling those features,
313 	   then turn them only after tweaking the values. */
314 	{ REG_COM8, COM8_FASTAEC | COM8_AECSTEP | COM8_BFILT },
315 	{ REG_GAIN, 0 },	{ REG_AECH, 0 },
316 	{ REG_COM4, 0x40 }, /* magic reserved bit */
317 	{ REG_COM9, 0x18 }, /* 4x gain + magic rsvd bit */
318 	{ REG_BD50MAX, 0x05 },	{ REG_BD60MAX, 0x07 },
319 	{ REG_AEW, 0x95 },	{ REG_AEB, 0x33 },
320 	{ REG_VPT, 0xe3 },	{ REG_HAECC1, 0x78 },
321 	{ REG_HAECC2, 0x68 },	{ 0xa1, 0x03 }, /* magic */
322 	{ REG_HAECC3, 0xd8 },	{ REG_HAECC4, 0xd8 },
323 	{ REG_HAECC5, 0xf0 },	{ REG_HAECC6, 0x90 },
324 	{ REG_HAECC7, 0x94 },
325 	{ REG_COM8, COM8_FASTAEC|COM8_AECSTEP|COM8_BFILT|COM8_AGC|COM8_AEC },
326 
327 	/* Almost all of these are magic "reserved" values.  */
328 	{ REG_COM5, 0x61 },	{ REG_COM6, 0x4b },
329 	{ 0x16, 0x02 },		{ REG_MVFP, 0x07 },
330 	{ 0x21, 0x02 },		{ 0x22, 0x91 },
331 	{ 0x29, 0x07 },		{ 0x33, 0x0b },
332 	{ 0x35, 0x0b },		{ 0x37, 0x1d },
333 	{ 0x38, 0x71 },		{ 0x39, 0x2a },
334 	{ REG_COM12, 0x78 },	{ 0x4d, 0x40 },
335 	{ 0x4e, 0x20 },		{ REG_GFIX, 0 },
336 	{ 0x6b, 0x4a },		{ 0x74, 0x10 },
337 	{ 0x8d, 0x4f },		{ 0x8e, 0 },
338 	{ 0x8f, 0 },		{ 0x90, 0 },
339 	{ 0x91, 0 },		{ 0x96, 0 },
340 	{ 0x9a, 0 },		{ 0xb0, 0x84 },
341 	{ 0xb1, 0x0c },		{ 0xb2, 0x0e },
342 	{ 0xb3, 0x82 },		{ 0xb8, 0x0a },
343 
344 	/* More reserved magic, some of which tweaks white balance */
345 	{ 0x43, 0x0a },		{ 0x44, 0xf0 },
346 	{ 0x45, 0x34 },		{ 0x46, 0x58 },
347 	{ 0x47, 0x28 },		{ 0x48, 0x3a },
348 	{ 0x59, 0x88 },		{ 0x5a, 0x88 },
349 	{ 0x5b, 0x44 },		{ 0x5c, 0x67 },
350 	{ 0x5d, 0x49 },		{ 0x5e, 0x0e },
351 	{ 0x6c, 0x0a },		{ 0x6d, 0x55 },
352 	{ 0x6e, 0x11 },		{ 0x6f, 0x9f }, /* "9e for advance AWB" */
353 	{ 0x6a, 0x40 },		{ REG_BLUE, 0x40 },
354 	{ REG_RED, 0x60 },
355 	{ REG_COM8, COM8_FASTAEC|COM8_AECSTEP|COM8_BFILT|COM8_AGC|COM8_AEC|COM8_AWB },
356 
357 	/* Matrix coefficients */
358 	{ 0x4f, 0x80 },		{ 0x50, 0x80 },
359 	{ 0x51, 0 },		{ 0x52, 0x22 },
360 	{ 0x53, 0x5e },		{ 0x54, 0x80 },
361 	{ 0x58, 0x9e },
362 
363 	{ REG_COM16, COM16_AWBGAIN },	{ REG_EDGE, 0 },
364 	{ 0x75, 0x05 },		{ 0x76, 0xe1 },
365 	{ 0x4c, 0 },		{ 0x77, 0x01 },
366 	{ REG_COM13, 0xc3 },	{ 0x4b, 0x09 },
367 	{ 0xc9, 0x60 },		{ REG_COM16, 0x38 },
368 	{ 0x56, 0x40 },
369 
370 	{ 0x34, 0x11 },		{ REG_COM11, COM11_EXP|COM11_HZAUTO },
371 	{ 0xa4, 0x88 },		{ 0x96, 0 },
372 	{ 0x97, 0x30 },		{ 0x98, 0x20 },
373 	{ 0x99, 0x30 },		{ 0x9a, 0x84 },
374 	{ 0x9b, 0x29 },		{ 0x9c, 0x03 },
375 	{ 0x9d, 0x4c },		{ 0x9e, 0x3f },
376 	{ 0x78, 0x04 },
377 
378 	/* Extra-weird stuff.  Some sort of multiplexor register */
379 	{ 0x79, 0x01 },		{ 0xc8, 0xf0 },
380 	{ 0x79, 0x0f },		{ 0xc8, 0x00 },
381 	{ 0x79, 0x10 },		{ 0xc8, 0x7e },
382 	{ 0x79, 0x0a },		{ 0xc8, 0x80 },
383 	{ 0x79, 0x0b },		{ 0xc8, 0x01 },
384 	{ 0x79, 0x0c },		{ 0xc8, 0x0f },
385 	{ 0x79, 0x0d },		{ 0xc8, 0x20 },
386 	{ 0x79, 0x09 },		{ 0xc8, 0x80 },
387 	{ 0x79, 0x02 },		{ 0xc8, 0xc0 },
388 	{ 0x79, 0x03 },		{ 0xc8, 0x40 },
389 	{ 0x79, 0x05 },		{ 0xc8, 0x30 },
390 	{ 0x79, 0x26 },
391 
392 	{ 0xff, 0xff },	/* END MARKER */
393 };
394 
395 
396 /*
397  * Here we'll try to encapsulate the changes for just the output
398  * video format.
399  *
400  * RGB656 and YUV422 come from OV; RGB444 is homebrewed.
401  *
402  * IMPORTANT RULE: the first entry must be for COM7, see ov7670_s_fmt for why.
403  */
404 
405 
406 static struct regval_list ov7670_fmt_yuv422[] = {
407 	{ REG_COM7, 0x0 },  /* Selects YUV mode */
408 	{ REG_RGB444, 0 },	/* No RGB444 please */
409 	{ REG_COM1, 0 },	/* CCIR601 */
410 	{ REG_COM15, COM15_R00FF },
411 	{ REG_COM9, 0x48 }, /* 32x gain ceiling; 0x8 is reserved bit */
412 	{ 0x4f, 0x80 }, 	/* "matrix coefficient 1" */
413 	{ 0x50, 0x80 }, 	/* "matrix coefficient 2" */
414 	{ 0x51, 0    },		/* vb */
415 	{ 0x52, 0x22 }, 	/* "matrix coefficient 4" */
416 	{ 0x53, 0x5e }, 	/* "matrix coefficient 5" */
417 	{ 0x54, 0x80 }, 	/* "matrix coefficient 6" */
418 	{ REG_COM13, COM13_GAMMA|COM13_UVSAT },
419 	{ 0xff, 0xff },
420 };
421 
422 static struct regval_list ov7670_fmt_rgb565[] = {
423 	{ REG_COM7, COM7_RGB },	/* Selects RGB mode */
424 	{ REG_RGB444, 0 },	/* No RGB444 please */
425 	{ REG_COM1, 0x0 },	/* CCIR601 */
426 	{ REG_COM15, COM15_RGB565 },
427 	{ REG_COM9, 0x38 }, 	/* 16x gain ceiling; 0x8 is reserved bit */
428 	{ 0x4f, 0xb3 }, 	/* "matrix coefficient 1" */
429 	{ 0x50, 0xb3 }, 	/* "matrix coefficient 2" */
430 	{ 0x51, 0    },		/* vb */
431 	{ 0x52, 0x3d }, 	/* "matrix coefficient 4" */
432 	{ 0x53, 0xa7 }, 	/* "matrix coefficient 5" */
433 	{ 0x54, 0xe4 }, 	/* "matrix coefficient 6" */
434 	{ REG_COM13, COM13_GAMMA|COM13_UVSAT },
435 	{ 0xff, 0xff },
436 };
437 
438 static struct regval_list ov7670_fmt_rgb444[] = {
439 	{ REG_COM7, COM7_RGB },	/* Selects RGB mode */
440 	{ REG_RGB444, R444_ENABLE },	/* Enable xxxxrrrr ggggbbbb */
441 	{ REG_COM1, 0x0 },	/* CCIR601 */
442 	{ REG_COM15, COM15_R01FE|COM15_RGB565 }, /* Data range needed? */
443 	{ REG_COM9, 0x38 }, 	/* 16x gain ceiling; 0x8 is reserved bit */
444 	{ 0x4f, 0xb3 }, 	/* "matrix coefficient 1" */
445 	{ 0x50, 0xb3 }, 	/* "matrix coefficient 2" */
446 	{ 0x51, 0    },		/* vb */
447 	{ 0x52, 0x3d }, 	/* "matrix coefficient 4" */
448 	{ 0x53, 0xa7 }, 	/* "matrix coefficient 5" */
449 	{ 0x54, 0xe4 }, 	/* "matrix coefficient 6" */
450 	{ REG_COM13, COM13_GAMMA|COM13_UVSAT|0x2 },  /* Magic rsvd bit */
451 	{ 0xff, 0xff },
452 };
453 
454 static struct regval_list ov7670_fmt_raw[] = {
455 	{ REG_COM7, COM7_BAYER },
456 	{ REG_COM13, 0x08 }, /* No gamma, magic rsvd bit */
457 	{ REG_COM16, 0x3d }, /* Edge enhancement, denoise */
458 	{ REG_REG76, 0xe1 }, /* Pix correction, magic rsvd */
459 	{ 0xff, 0xff },
460 };
461 
462 
463 
464 /*
465  * Low-level register I/O.
466  *
467  * Note that there are two versions of these.  On the XO 1, the
468  * i2c controller only does SMBUS, so that's what we use.  The
469  * ov7670 is not really an SMBUS device, though, so the communication
470  * is not always entirely reliable.
471  */
472 static int ov7670_read_smbus(struct v4l2_subdev *sd, unsigned char reg,
473 		unsigned char *value)
474 {
475 	struct i2c_client *client = v4l2_get_subdevdata(sd);
476 	int ret;
477 
478 	ret = i2c_smbus_read_byte_data(client, reg);
479 	if (ret >= 0) {
480 		*value = (unsigned char)ret;
481 		ret = 0;
482 	}
483 	return ret;
484 }
485 
486 
487 static int ov7670_write_smbus(struct v4l2_subdev *sd, unsigned char reg,
488 		unsigned char value)
489 {
490 	struct i2c_client *client = v4l2_get_subdevdata(sd);
491 	int ret = i2c_smbus_write_byte_data(client, reg, value);
492 
493 	if (reg == REG_COM7 && (value & COM7_RESET))
494 		msleep(5);  /* Wait for reset to run */
495 	return ret;
496 }
497 
498 /*
499  * On most platforms, we'd rather do straight i2c I/O.
500  */
501 static int ov7670_read_i2c(struct v4l2_subdev *sd, unsigned char reg,
502 		unsigned char *value)
503 {
504 	struct i2c_client *client = v4l2_get_subdevdata(sd);
505 	u8 data = reg;
506 	struct i2c_msg msg;
507 	int ret;
508 
509 	/*
510 	 * Send out the register address...
511 	 */
512 	msg.addr = client->addr;
513 	msg.flags = 0;
514 	msg.len = 1;
515 	msg.buf = &data;
516 	ret = i2c_transfer(client->adapter, &msg, 1);
517 	if (ret < 0) {
518 		printk(KERN_ERR "Error %d on register write\n", ret);
519 		return ret;
520 	}
521 	/*
522 	 * ...then read back the result.
523 	 */
524 	msg.flags = I2C_M_RD;
525 	ret = i2c_transfer(client->adapter, &msg, 1);
526 	if (ret >= 0) {
527 		*value = data;
528 		ret = 0;
529 	}
530 	return ret;
531 }
532 
533 
534 static int ov7670_write_i2c(struct v4l2_subdev *sd, unsigned char reg,
535 		unsigned char value)
536 {
537 	struct i2c_client *client = v4l2_get_subdevdata(sd);
538 	struct i2c_msg msg;
539 	unsigned char data[2] = { reg, value };
540 	int ret;
541 
542 	msg.addr = client->addr;
543 	msg.flags = 0;
544 	msg.len = 2;
545 	msg.buf = data;
546 	ret = i2c_transfer(client->adapter, &msg, 1);
547 	if (ret > 0)
548 		ret = 0;
549 	if (reg == REG_COM7 && (value & COM7_RESET))
550 		msleep(5);  /* Wait for reset to run */
551 	return ret;
552 }
553 
554 static int ov7670_read(struct v4l2_subdev *sd, unsigned char reg,
555 		unsigned char *value)
556 {
557 	struct ov7670_info *info = to_state(sd);
558 	if (info->use_smbus)
559 		return ov7670_read_smbus(sd, reg, value);
560 	else
561 		return ov7670_read_i2c(sd, reg, value);
562 }
563 
564 static int ov7670_write(struct v4l2_subdev *sd, unsigned char reg,
565 		unsigned char value)
566 {
567 	struct ov7670_info *info = to_state(sd);
568 	if (info->use_smbus)
569 		return ov7670_write_smbus(sd, reg, value);
570 	else
571 		return ov7670_write_i2c(sd, reg, value);
572 }
573 
574 /*
575  * Write a list of register settings; ff/ff stops the process.
576  */
577 static int ov7670_write_array(struct v4l2_subdev *sd, struct regval_list *vals)
578 {
579 	while (vals->reg_num != 0xff || vals->value != 0xff) {
580 		int ret = ov7670_write(sd, vals->reg_num, vals->value);
581 		if (ret < 0)
582 			return ret;
583 		vals++;
584 	}
585 	return 0;
586 }
587 
588 
589 /*
590  * Stuff that knows about the sensor.
591  */
592 static int ov7670_reset(struct v4l2_subdev *sd, u32 val)
593 {
594 	ov7670_write(sd, REG_COM7, COM7_RESET);
595 	msleep(1);
596 	return 0;
597 }
598 
599 
600 static int ov7670_init(struct v4l2_subdev *sd, u32 val)
601 {
602 	return ov7670_write_array(sd, ov7670_default_regs);
603 }
604 
605 
606 
607 static int ov7670_detect(struct v4l2_subdev *sd)
608 {
609 	unsigned char v;
610 	int ret;
611 
612 	ret = ov7670_init(sd, 0);
613 	if (ret < 0)
614 		return ret;
615 	ret = ov7670_read(sd, REG_MIDH, &v);
616 	if (ret < 0)
617 		return ret;
618 	if (v != 0x7f) /* OV manuf. id. */
619 		return -ENODEV;
620 	ret = ov7670_read(sd, REG_MIDL, &v);
621 	if (ret < 0)
622 		return ret;
623 	if (v != 0xa2)
624 		return -ENODEV;
625 	/*
626 	 * OK, we know we have an OmniVision chip...but which one?
627 	 */
628 	ret = ov7670_read(sd, REG_PID, &v);
629 	if (ret < 0)
630 		return ret;
631 	if (v != 0x76)  /* PID + VER = 0x76 / 0x73 */
632 		return -ENODEV;
633 	ret = ov7670_read(sd, REG_VER, &v);
634 	if (ret < 0)
635 		return ret;
636 	if (v != 0x73)  /* PID + VER = 0x76 / 0x73 */
637 		return -ENODEV;
638 	return 0;
639 }
640 
641 
642 /*
643  * Store information about the video data format.  The color matrix
644  * is deeply tied into the format, so keep the relevant values here.
645  * The magic matrix numbers come from OmniVision.
646  */
647 static struct ov7670_format_struct {
648 	enum v4l2_mbus_pixelcode mbus_code;
649 	enum v4l2_colorspace colorspace;
650 	struct regval_list *regs;
651 	int cmatrix[CMATRIX_LEN];
652 } ov7670_formats[] = {
653 	{
654 		.mbus_code	= V4L2_MBUS_FMT_YUYV8_2X8,
655 		.colorspace	= V4L2_COLORSPACE_JPEG,
656 		.regs 		= ov7670_fmt_yuv422,
657 		.cmatrix	= { 128, -128, 0, -34, -94, 128 },
658 	},
659 	{
660 		.mbus_code	= V4L2_MBUS_FMT_RGB444_2X8_PADHI_LE,
661 		.colorspace	= V4L2_COLORSPACE_SRGB,
662 		.regs		= ov7670_fmt_rgb444,
663 		.cmatrix	= { 179, -179, 0, -61, -176, 228 },
664 	},
665 	{
666 		.mbus_code	= V4L2_MBUS_FMT_RGB565_2X8_LE,
667 		.colorspace	= V4L2_COLORSPACE_SRGB,
668 		.regs		= ov7670_fmt_rgb565,
669 		.cmatrix	= { 179, -179, 0, -61, -176, 228 },
670 	},
671 	{
672 		.mbus_code	= V4L2_MBUS_FMT_SBGGR8_1X8,
673 		.colorspace	= V4L2_COLORSPACE_SRGB,
674 		.regs 		= ov7670_fmt_raw,
675 		.cmatrix	= { 0, 0, 0, 0, 0, 0 },
676 	},
677 };
678 #define N_OV7670_FMTS ARRAY_SIZE(ov7670_formats)
679 
680 
681 /*
682  * Then there is the issue of window sizes.  Try to capture the info here.
683  */
684 
685 /*
686  * QCIF mode is done (by OV) in a very strange way - it actually looks like
687  * VGA with weird scaling options - they do *not* use the canned QCIF mode
688  * which is allegedly provided by the sensor.  So here's the weird register
689  * settings.
690  */
691 static struct regval_list ov7670_qcif_regs[] = {
692 	{ REG_COM3, COM3_SCALEEN|COM3_DCWEN },
693 	{ REG_COM3, COM3_DCWEN },
694 	{ REG_COM14, COM14_DCWEN | 0x01},
695 	{ 0x73, 0xf1 },
696 	{ 0xa2, 0x52 },
697 	{ 0x7b, 0x1c },
698 	{ 0x7c, 0x28 },
699 	{ 0x7d, 0x3c },
700 	{ 0x7f, 0x69 },
701 	{ REG_COM9, 0x38 },
702 	{ 0xa1, 0x0b },
703 	{ 0x74, 0x19 },
704 	{ 0x9a, 0x80 },
705 	{ 0x43, 0x14 },
706 	{ REG_COM13, 0xc0 },
707 	{ 0xff, 0xff },
708 };
709 
710 static struct ov7670_win_size ov7670_win_sizes[] = {
711 	/* VGA */
712 	{
713 		.width		= VGA_WIDTH,
714 		.height		= VGA_HEIGHT,
715 		.com7_bit	= COM7_FMT_VGA,
716 		.hstart		= 158,	/* These values from */
717 		.hstop		=  14,	/* Omnivision */
718 		.vstart		=  10,
719 		.vstop		= 490,
720 		.regs		= NULL,
721 	},
722 	/* CIF */
723 	{
724 		.width		= CIF_WIDTH,
725 		.height		= CIF_HEIGHT,
726 		.com7_bit	= COM7_FMT_CIF,
727 		.hstart		= 170,	/* Empirically determined */
728 		.hstop		=  90,
729 		.vstart		=  14,
730 		.vstop		= 494,
731 		.regs		= NULL,
732 	},
733 	/* QVGA */
734 	{
735 		.width		= QVGA_WIDTH,
736 		.height		= QVGA_HEIGHT,
737 		.com7_bit	= COM7_FMT_QVGA,
738 		.hstart		= 168,	/* Empirically determined */
739 		.hstop		=  24,
740 		.vstart		=  12,
741 		.vstop		= 492,
742 		.regs		= NULL,
743 	},
744 	/* QCIF */
745 	{
746 		.width		= QCIF_WIDTH,
747 		.height		= QCIF_HEIGHT,
748 		.com7_bit	= COM7_FMT_VGA, /* see comment above */
749 		.hstart		= 456,	/* Empirically determined */
750 		.hstop		=  24,
751 		.vstart		=  14,
752 		.vstop		= 494,
753 		.regs		= ov7670_qcif_regs,
754 	}
755 };
756 
757 static struct ov7670_win_size ov7675_win_sizes[] = {
758 	/*
759 	 * Currently, only VGA is supported. Theoretically it could be possible
760 	 * to support CIF, QVGA and QCIF too. Taking values for ov7670 as a
761 	 * base and tweak them empirically could be required.
762 	 */
763 	{
764 		.width		= VGA_WIDTH,
765 		.height		= VGA_HEIGHT,
766 		.com7_bit	= COM7_FMT_VGA,
767 		.hstart		= 158,	/* These values from */
768 		.hstop		=  14,	/* Omnivision */
769 		.vstart		=  14,  /* Empirically determined */
770 		.vstop		= 494,
771 		.regs		= NULL,
772 	}
773 };
774 
775 static void ov7675_get_framerate(struct v4l2_subdev *sd,
776 				 struct v4l2_fract *tpf)
777 {
778 	struct ov7670_info *info = to_state(sd);
779 	u32 clkrc = info->clkrc;
780 	int pll_factor;
781 
782 	if (info->pll_bypass)
783 		pll_factor = 1;
784 	else
785 		pll_factor = PLL_FACTOR;
786 
787 	clkrc++;
788 	if (info->fmt->mbus_code == V4L2_MBUS_FMT_SBGGR8_1X8)
789 		clkrc = (clkrc >> 1);
790 
791 	tpf->numerator = 1;
792 	tpf->denominator = (5 * pll_factor * info->clock_speed) /
793 			(4 * clkrc);
794 }
795 
796 static int ov7675_set_framerate(struct v4l2_subdev *sd,
797 				 struct v4l2_fract *tpf)
798 {
799 	struct ov7670_info *info = to_state(sd);
800 	u32 clkrc;
801 	int pll_factor;
802 	int ret;
803 
804 	/*
805 	 * The formula is fps = 5/4*pixclk for YUV/RGB and
806 	 * fps = 5/2*pixclk for RAW.
807 	 *
808 	 * pixclk = clock_speed / (clkrc + 1) * PLLfactor
809 	 *
810 	 */
811 	if (info->pll_bypass) {
812 		pll_factor = 1;
813 		ret = ov7670_write(sd, REG_DBLV, DBLV_BYPASS);
814 	} else {
815 		pll_factor = PLL_FACTOR;
816 		ret = ov7670_write(sd, REG_DBLV, DBLV_X4);
817 	}
818 	if (ret < 0)
819 		return ret;
820 
821 	if (tpf->numerator == 0 || tpf->denominator == 0) {
822 		clkrc = 0;
823 	} else {
824 		clkrc = (5 * pll_factor * info->clock_speed * tpf->numerator) /
825 			(4 * tpf->denominator);
826 		if (info->fmt->mbus_code == V4L2_MBUS_FMT_SBGGR8_1X8)
827 			clkrc = (clkrc << 1);
828 		clkrc--;
829 	}
830 
831 	/*
832 	 * The datasheet claims that clkrc = 0 will divide the input clock by 1
833 	 * but we've checked with an oscilloscope that it divides by 2 instead.
834 	 * So, if clkrc = 0 just bypass the divider.
835 	 */
836 	if (clkrc <= 0)
837 		clkrc = CLK_EXT;
838 	else if (clkrc > CLK_SCALE)
839 		clkrc = CLK_SCALE;
840 	info->clkrc = clkrc;
841 
842 	/* Recalculate frame rate */
843 	ov7675_get_framerate(sd, tpf);
844 
845 	ret = ov7670_write(sd, REG_CLKRC, info->clkrc);
846 	if (ret < 0)
847 		return ret;
848 
849 	return ov7670_write(sd, REG_DBLV, DBLV_X4);
850 }
851 
852 static void ov7670_get_framerate_legacy(struct v4l2_subdev *sd,
853 				 struct v4l2_fract *tpf)
854 {
855 	struct ov7670_info *info = to_state(sd);
856 
857 	tpf->numerator = 1;
858 	tpf->denominator = info->clock_speed;
859 	if ((info->clkrc & CLK_EXT) == 0 && (info->clkrc & CLK_SCALE) > 1)
860 		tpf->denominator /= (info->clkrc & CLK_SCALE);
861 }
862 
863 static int ov7670_set_framerate_legacy(struct v4l2_subdev *sd,
864 					struct v4l2_fract *tpf)
865 {
866 	struct ov7670_info *info = to_state(sd);
867 	int div;
868 
869 	if (tpf->numerator == 0 || tpf->denominator == 0)
870 		div = 1;  /* Reset to full rate */
871 	else
872 		div = (tpf->numerator * info->clock_speed) / tpf->denominator;
873 	if (div == 0)
874 		div = 1;
875 	else if (div > CLK_SCALE)
876 		div = CLK_SCALE;
877 	info->clkrc = (info->clkrc & 0x80) | div;
878 	tpf->numerator = 1;
879 	tpf->denominator = info->clock_speed / div;
880 	return ov7670_write(sd, REG_CLKRC, info->clkrc);
881 }
882 
883 /*
884  * Store a set of start/stop values into the camera.
885  */
886 static int ov7670_set_hw(struct v4l2_subdev *sd, int hstart, int hstop,
887 		int vstart, int vstop)
888 {
889 	int ret;
890 	unsigned char v;
891 /*
892  * Horizontal: 11 bits, top 8 live in hstart and hstop.  Bottom 3 of
893  * hstart are in href[2:0], bottom 3 of hstop in href[5:3].  There is
894  * a mystery "edge offset" value in the top two bits of href.
895  */
896 	ret =  ov7670_write(sd, REG_HSTART, (hstart >> 3) & 0xff);
897 	ret += ov7670_write(sd, REG_HSTOP, (hstop >> 3) & 0xff);
898 	ret += ov7670_read(sd, REG_HREF, &v);
899 	v = (v & 0xc0) | ((hstop & 0x7) << 3) | (hstart & 0x7);
900 	msleep(10);
901 	ret += ov7670_write(sd, REG_HREF, v);
902 /*
903  * Vertical: similar arrangement, but only 10 bits.
904  */
905 	ret += ov7670_write(sd, REG_VSTART, (vstart >> 2) & 0xff);
906 	ret += ov7670_write(sd, REG_VSTOP, (vstop >> 2) & 0xff);
907 	ret += ov7670_read(sd, REG_VREF, &v);
908 	v = (v & 0xf0) | ((vstop & 0x3) << 2) | (vstart & 0x3);
909 	msleep(10);
910 	ret += ov7670_write(sd, REG_VREF, v);
911 	return ret;
912 }
913 
914 
915 static int ov7670_enum_mbus_fmt(struct v4l2_subdev *sd, unsigned index,
916 					enum v4l2_mbus_pixelcode *code)
917 {
918 	if (index >= N_OV7670_FMTS)
919 		return -EINVAL;
920 
921 	*code = ov7670_formats[index].mbus_code;
922 	return 0;
923 }
924 
925 static int ov7670_try_fmt_internal(struct v4l2_subdev *sd,
926 		struct v4l2_mbus_framefmt *fmt,
927 		struct ov7670_format_struct **ret_fmt,
928 		struct ov7670_win_size **ret_wsize)
929 {
930 	int index, i;
931 	struct ov7670_win_size *wsize;
932 	struct ov7670_info *info = to_state(sd);
933 	unsigned int n_win_sizes = info->devtype->n_win_sizes;
934 	unsigned int win_sizes_limit = n_win_sizes;
935 
936 	for (index = 0; index < N_OV7670_FMTS; index++)
937 		if (ov7670_formats[index].mbus_code == fmt->code)
938 			break;
939 	if (index >= N_OV7670_FMTS) {
940 		/* default to first format */
941 		index = 0;
942 		fmt->code = ov7670_formats[0].mbus_code;
943 	}
944 	if (ret_fmt != NULL)
945 		*ret_fmt = ov7670_formats + index;
946 	/*
947 	 * Fields: the OV devices claim to be progressive.
948 	 */
949 	fmt->field = V4L2_FIELD_NONE;
950 
951 	/*
952 	 * Don't consider values that don't match min_height and min_width
953 	 * constraints.
954 	 */
955 	if (info->min_width || info->min_height)
956 		for (i = 0; i < n_win_sizes; i++) {
957 			wsize = info->devtype->win_sizes + i;
958 
959 			if (wsize->width < info->min_width ||
960 				wsize->height < info->min_height) {
961 				win_sizes_limit = i;
962 				break;
963 			}
964 		}
965 	/*
966 	 * Round requested image size down to the nearest
967 	 * we support, but not below the smallest.
968 	 */
969 	for (wsize = info->devtype->win_sizes;
970 	     wsize < info->devtype->win_sizes + win_sizes_limit; wsize++)
971 		if (fmt->width >= wsize->width && fmt->height >= wsize->height)
972 			break;
973 	if (wsize >= info->devtype->win_sizes + win_sizes_limit)
974 		wsize--;   /* Take the smallest one */
975 	if (ret_wsize != NULL)
976 		*ret_wsize = wsize;
977 	/*
978 	 * Note the size we'll actually handle.
979 	 */
980 	fmt->width = wsize->width;
981 	fmt->height = wsize->height;
982 	fmt->colorspace = ov7670_formats[index].colorspace;
983 	return 0;
984 }
985 
986 static int ov7670_try_mbus_fmt(struct v4l2_subdev *sd,
987 			    struct v4l2_mbus_framefmt *fmt)
988 {
989 	return ov7670_try_fmt_internal(sd, fmt, NULL, NULL);
990 }
991 
992 /*
993  * Set a format.
994  */
995 static int ov7670_s_mbus_fmt(struct v4l2_subdev *sd,
996 			  struct v4l2_mbus_framefmt *fmt)
997 {
998 	struct ov7670_format_struct *ovfmt;
999 	struct ov7670_win_size *wsize;
1000 	struct ov7670_info *info = to_state(sd);
1001 	unsigned char com7;
1002 	int ret;
1003 
1004 	ret = ov7670_try_fmt_internal(sd, fmt, &ovfmt, &wsize);
1005 
1006 	if (ret)
1007 		return ret;
1008 	/*
1009 	 * COM7 is a pain in the ass, it doesn't like to be read then
1010 	 * quickly written afterward.  But we have everything we need
1011 	 * to set it absolutely here, as long as the format-specific
1012 	 * register sets list it first.
1013 	 */
1014 	com7 = ovfmt->regs[0].value;
1015 	com7 |= wsize->com7_bit;
1016 	ov7670_write(sd, REG_COM7, com7);
1017 	/*
1018 	 * Now write the rest of the array.  Also store start/stops
1019 	 */
1020 	ov7670_write_array(sd, ovfmt->regs + 1);
1021 	ov7670_set_hw(sd, wsize->hstart, wsize->hstop, wsize->vstart,
1022 			wsize->vstop);
1023 	ret = 0;
1024 	if (wsize->regs)
1025 		ret = ov7670_write_array(sd, wsize->regs);
1026 	info->fmt = ovfmt;
1027 
1028 	/*
1029 	 * If we're running RGB565, we must rewrite clkrc after setting
1030 	 * the other parameters or the image looks poor.  If we're *not*
1031 	 * doing RGB565, we must not rewrite clkrc or the image looks
1032 	 * *really* poor.
1033 	 *
1034 	 * (Update) Now that we retain clkrc state, we should be able
1035 	 * to write it unconditionally, and that will make the frame
1036 	 * rate persistent too.
1037 	 */
1038 	if (ret == 0)
1039 		ret = ov7670_write(sd, REG_CLKRC, info->clkrc);
1040 	return 0;
1041 }
1042 
1043 /*
1044  * Implement G/S_PARM.  There is a "high quality" mode we could try
1045  * to do someday; for now, we just do the frame rate tweak.
1046  */
1047 static int ov7670_g_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
1048 {
1049 	struct v4l2_captureparm *cp = &parms->parm.capture;
1050 	struct ov7670_info *info = to_state(sd);
1051 
1052 	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1053 		return -EINVAL;
1054 
1055 	memset(cp, 0, sizeof(struct v4l2_captureparm));
1056 	cp->capability = V4L2_CAP_TIMEPERFRAME;
1057 	info->devtype->get_framerate(sd, &cp->timeperframe);
1058 
1059 	return 0;
1060 }
1061 
1062 static int ov7670_s_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
1063 {
1064 	struct v4l2_captureparm *cp = &parms->parm.capture;
1065 	struct v4l2_fract *tpf = &cp->timeperframe;
1066 	struct ov7670_info *info = to_state(sd);
1067 
1068 	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1069 		return -EINVAL;
1070 	if (cp->extendedmode != 0)
1071 		return -EINVAL;
1072 
1073 	return info->devtype->set_framerate(sd, tpf);
1074 }
1075 
1076 
1077 /*
1078  * Frame intervals.  Since frame rates are controlled with the clock
1079  * divider, we can only do 30/n for integer n values.  So no continuous
1080  * or stepwise options.  Here we just pick a handful of logical values.
1081  */
1082 
1083 static int ov7670_frame_rates[] = { 30, 15, 10, 5, 1 };
1084 
1085 static int ov7670_enum_frameintervals(struct v4l2_subdev *sd,
1086 		struct v4l2_frmivalenum *interval)
1087 {
1088 	if (interval->index >= ARRAY_SIZE(ov7670_frame_rates))
1089 		return -EINVAL;
1090 	interval->type = V4L2_FRMIVAL_TYPE_DISCRETE;
1091 	interval->discrete.numerator = 1;
1092 	interval->discrete.denominator = ov7670_frame_rates[interval->index];
1093 	return 0;
1094 }
1095 
1096 /*
1097  * Frame size enumeration
1098  */
1099 static int ov7670_enum_framesizes(struct v4l2_subdev *sd,
1100 		struct v4l2_frmsizeenum *fsize)
1101 {
1102 	struct ov7670_info *info = to_state(sd);
1103 	int i;
1104 	int num_valid = -1;
1105 	__u32 index = fsize->index;
1106 	unsigned int n_win_sizes = info->devtype->n_win_sizes;
1107 
1108 	/*
1109 	 * If a minimum width/height was requested, filter out the capture
1110 	 * windows that fall outside that.
1111 	 */
1112 	for (i = 0; i < n_win_sizes; i++) {
1113 		struct ov7670_win_size *win = &info->devtype->win_sizes[index];
1114 		if (info->min_width && win->width < info->min_width)
1115 			continue;
1116 		if (info->min_height && win->height < info->min_height)
1117 			continue;
1118 		if (index == ++num_valid) {
1119 			fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
1120 			fsize->discrete.width = win->width;
1121 			fsize->discrete.height = win->height;
1122 			return 0;
1123 		}
1124 	}
1125 
1126 	return -EINVAL;
1127 }
1128 
1129 /*
1130  * Code for dealing with controls.
1131  */
1132 
1133 static int ov7670_store_cmatrix(struct v4l2_subdev *sd,
1134 		int matrix[CMATRIX_LEN])
1135 {
1136 	int i, ret;
1137 	unsigned char signbits = 0;
1138 
1139 	/*
1140 	 * Weird crap seems to exist in the upper part of
1141 	 * the sign bits register, so let's preserve it.
1142 	 */
1143 	ret = ov7670_read(sd, REG_CMATRIX_SIGN, &signbits);
1144 	signbits &= 0xc0;
1145 
1146 	for (i = 0; i < CMATRIX_LEN; i++) {
1147 		unsigned char raw;
1148 
1149 		if (matrix[i] < 0) {
1150 			signbits |= (1 << i);
1151 			if (matrix[i] < -255)
1152 				raw = 0xff;
1153 			else
1154 				raw = (-1 * matrix[i]) & 0xff;
1155 		}
1156 		else {
1157 			if (matrix[i] > 255)
1158 				raw = 0xff;
1159 			else
1160 				raw = matrix[i] & 0xff;
1161 		}
1162 		ret += ov7670_write(sd, REG_CMATRIX_BASE + i, raw);
1163 	}
1164 	ret += ov7670_write(sd, REG_CMATRIX_SIGN, signbits);
1165 	return ret;
1166 }
1167 
1168 
1169 /*
1170  * Hue also requires messing with the color matrix.  It also requires
1171  * trig functions, which tend not to be well supported in the kernel.
1172  * So here is a simple table of sine values, 0-90 degrees, in steps
1173  * of five degrees.  Values are multiplied by 1000.
1174  *
1175  * The following naive approximate trig functions require an argument
1176  * carefully limited to -180 <= theta <= 180.
1177  */
1178 #define SIN_STEP 5
1179 static const int ov7670_sin_table[] = {
1180 	   0,	 87,   173,   258,   342,   422,
1181 	 499,	573,   642,   707,   766,   819,
1182 	 866,	906,   939,   965,   984,   996,
1183 	1000
1184 };
1185 
1186 static int ov7670_sine(int theta)
1187 {
1188 	int chs = 1;
1189 	int sine;
1190 
1191 	if (theta < 0) {
1192 		theta = -theta;
1193 		chs = -1;
1194 	}
1195 	if (theta <= 90)
1196 		sine = ov7670_sin_table[theta/SIN_STEP];
1197 	else {
1198 		theta -= 90;
1199 		sine = 1000 - ov7670_sin_table[theta/SIN_STEP];
1200 	}
1201 	return sine*chs;
1202 }
1203 
1204 static int ov7670_cosine(int theta)
1205 {
1206 	theta = 90 - theta;
1207 	if (theta > 180)
1208 		theta -= 360;
1209 	else if (theta < -180)
1210 		theta += 360;
1211 	return ov7670_sine(theta);
1212 }
1213 
1214 
1215 
1216 
1217 static void ov7670_calc_cmatrix(struct ov7670_info *info,
1218 		int matrix[CMATRIX_LEN], int sat, int hue)
1219 {
1220 	int i;
1221 	/*
1222 	 * Apply the current saturation setting first.
1223 	 */
1224 	for (i = 0; i < CMATRIX_LEN; i++)
1225 		matrix[i] = (info->fmt->cmatrix[i] * sat) >> 7;
1226 	/*
1227 	 * Then, if need be, rotate the hue value.
1228 	 */
1229 	if (hue != 0) {
1230 		int sinth, costh, tmpmatrix[CMATRIX_LEN];
1231 
1232 		memcpy(tmpmatrix, matrix, CMATRIX_LEN*sizeof(int));
1233 		sinth = ov7670_sine(hue);
1234 		costh = ov7670_cosine(hue);
1235 
1236 		matrix[0] = (matrix[3]*sinth + matrix[0]*costh)/1000;
1237 		matrix[1] = (matrix[4]*sinth + matrix[1]*costh)/1000;
1238 		matrix[2] = (matrix[5]*sinth + matrix[2]*costh)/1000;
1239 		matrix[3] = (matrix[3]*costh - matrix[0]*sinth)/1000;
1240 		matrix[4] = (matrix[4]*costh - matrix[1]*sinth)/1000;
1241 		matrix[5] = (matrix[5]*costh - matrix[2]*sinth)/1000;
1242 	}
1243 }
1244 
1245 
1246 
1247 static int ov7670_s_sat_hue(struct v4l2_subdev *sd, int sat, int hue)
1248 {
1249 	struct ov7670_info *info = to_state(sd);
1250 	int matrix[CMATRIX_LEN];
1251 	int ret;
1252 
1253 	ov7670_calc_cmatrix(info, matrix, sat, hue);
1254 	ret = ov7670_store_cmatrix(sd, matrix);
1255 	return ret;
1256 }
1257 
1258 
1259 /*
1260  * Some weird registers seem to store values in a sign/magnitude format!
1261  */
1262 
1263 static unsigned char ov7670_abs_to_sm(unsigned char v)
1264 {
1265 	if (v > 127)
1266 		return v & 0x7f;
1267 	return (128 - v) | 0x80;
1268 }
1269 
1270 static int ov7670_s_brightness(struct v4l2_subdev *sd, int value)
1271 {
1272 	unsigned char com8 = 0, v;
1273 	int ret;
1274 
1275 	ov7670_read(sd, REG_COM8, &com8);
1276 	com8 &= ~COM8_AEC;
1277 	ov7670_write(sd, REG_COM8, com8);
1278 	v = ov7670_abs_to_sm(value);
1279 	ret = ov7670_write(sd, REG_BRIGHT, v);
1280 	return ret;
1281 }
1282 
1283 static int ov7670_s_contrast(struct v4l2_subdev *sd, int value)
1284 {
1285 	return ov7670_write(sd, REG_CONTRAS, (unsigned char) value);
1286 }
1287 
1288 static int ov7670_s_hflip(struct v4l2_subdev *sd, int value)
1289 {
1290 	unsigned char v = 0;
1291 	int ret;
1292 
1293 	ret = ov7670_read(sd, REG_MVFP, &v);
1294 	if (value)
1295 		v |= MVFP_MIRROR;
1296 	else
1297 		v &= ~MVFP_MIRROR;
1298 	msleep(10);  /* FIXME */
1299 	ret += ov7670_write(sd, REG_MVFP, v);
1300 	return ret;
1301 }
1302 
1303 static int ov7670_s_vflip(struct v4l2_subdev *sd, int value)
1304 {
1305 	unsigned char v = 0;
1306 	int ret;
1307 
1308 	ret = ov7670_read(sd, REG_MVFP, &v);
1309 	if (value)
1310 		v |= MVFP_FLIP;
1311 	else
1312 		v &= ~MVFP_FLIP;
1313 	msleep(10);  /* FIXME */
1314 	ret += ov7670_write(sd, REG_MVFP, v);
1315 	return ret;
1316 }
1317 
1318 /*
1319  * GAIN is split between REG_GAIN and REG_VREF[7:6].  If one believes
1320  * the data sheet, the VREF parts should be the most significant, but
1321  * experience shows otherwise.  There seems to be little value in
1322  * messing with the VREF bits, so we leave them alone.
1323  */
1324 static int ov7670_g_gain(struct v4l2_subdev *sd, __s32 *value)
1325 {
1326 	int ret;
1327 	unsigned char gain;
1328 
1329 	ret = ov7670_read(sd, REG_GAIN, &gain);
1330 	*value = gain;
1331 	return ret;
1332 }
1333 
1334 static int ov7670_s_gain(struct v4l2_subdev *sd, int value)
1335 {
1336 	int ret;
1337 	unsigned char com8;
1338 
1339 	ret = ov7670_write(sd, REG_GAIN, value & 0xff);
1340 	/* Have to turn off AGC as well */
1341 	if (ret == 0) {
1342 		ret = ov7670_read(sd, REG_COM8, &com8);
1343 		ret = ov7670_write(sd, REG_COM8, com8 & ~COM8_AGC);
1344 	}
1345 	return ret;
1346 }
1347 
1348 /*
1349  * Tweak autogain.
1350  */
1351 static int ov7670_s_autogain(struct v4l2_subdev *sd, int value)
1352 {
1353 	int ret;
1354 	unsigned char com8;
1355 
1356 	ret = ov7670_read(sd, REG_COM8, &com8);
1357 	if (ret == 0) {
1358 		if (value)
1359 			com8 |= COM8_AGC;
1360 		else
1361 			com8 &= ~COM8_AGC;
1362 		ret = ov7670_write(sd, REG_COM8, com8);
1363 	}
1364 	return ret;
1365 }
1366 
1367 static int ov7670_s_exp(struct v4l2_subdev *sd, int value)
1368 {
1369 	int ret;
1370 	unsigned char com1, com8, aech, aechh;
1371 
1372 	ret = ov7670_read(sd, REG_COM1, &com1) +
1373 		ov7670_read(sd, REG_COM8, &com8);
1374 		ov7670_read(sd, REG_AECHH, &aechh);
1375 	if (ret)
1376 		return ret;
1377 
1378 	com1 = (com1 & 0xfc) | (value & 0x03);
1379 	aech = (value >> 2) & 0xff;
1380 	aechh = (aechh & 0xc0) | ((value >> 10) & 0x3f);
1381 	ret = ov7670_write(sd, REG_COM1, com1) +
1382 		ov7670_write(sd, REG_AECH, aech) +
1383 		ov7670_write(sd, REG_AECHH, aechh);
1384 	/* Have to turn off AEC as well */
1385 	if (ret == 0)
1386 		ret = ov7670_write(sd, REG_COM8, com8 & ~COM8_AEC);
1387 	return ret;
1388 }
1389 
1390 /*
1391  * Tweak autoexposure.
1392  */
1393 static int ov7670_s_autoexp(struct v4l2_subdev *sd,
1394 		enum v4l2_exposure_auto_type value)
1395 {
1396 	int ret;
1397 	unsigned char com8;
1398 
1399 	ret = ov7670_read(sd, REG_COM8, &com8);
1400 	if (ret == 0) {
1401 		if (value == V4L2_EXPOSURE_AUTO)
1402 			com8 |= COM8_AEC;
1403 		else
1404 			com8 &= ~COM8_AEC;
1405 		ret = ov7670_write(sd, REG_COM8, com8);
1406 	}
1407 	return ret;
1408 }
1409 
1410 
1411 static int ov7670_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
1412 {
1413 	struct v4l2_subdev *sd = to_sd(ctrl);
1414 	struct ov7670_info *info = to_state(sd);
1415 
1416 	switch (ctrl->id) {
1417 	case V4L2_CID_AUTOGAIN:
1418 		return ov7670_g_gain(sd, &info->gain->val);
1419 	}
1420 	return -EINVAL;
1421 }
1422 
1423 static int ov7670_s_ctrl(struct v4l2_ctrl *ctrl)
1424 {
1425 	struct v4l2_subdev *sd = to_sd(ctrl);
1426 	struct ov7670_info *info = to_state(sd);
1427 
1428 	switch (ctrl->id) {
1429 	case V4L2_CID_BRIGHTNESS:
1430 		return ov7670_s_brightness(sd, ctrl->val);
1431 	case V4L2_CID_CONTRAST:
1432 		return ov7670_s_contrast(sd, ctrl->val);
1433 	case V4L2_CID_SATURATION:
1434 		return ov7670_s_sat_hue(sd,
1435 				info->saturation->val, info->hue->val);
1436 	case V4L2_CID_VFLIP:
1437 		return ov7670_s_vflip(sd, ctrl->val);
1438 	case V4L2_CID_HFLIP:
1439 		return ov7670_s_hflip(sd, ctrl->val);
1440 	case V4L2_CID_AUTOGAIN:
1441 		/* Only set manual gain if auto gain is not explicitly
1442 		   turned on. */
1443 		if (!ctrl->val) {
1444 			/* ov7670_s_gain turns off auto gain */
1445 			return ov7670_s_gain(sd, info->gain->val);
1446 		}
1447 		return ov7670_s_autogain(sd, ctrl->val);
1448 	case V4L2_CID_EXPOSURE_AUTO:
1449 		/* Only set manual exposure if auto exposure is not explicitly
1450 		   turned on. */
1451 		if (ctrl->val == V4L2_EXPOSURE_MANUAL) {
1452 			/* ov7670_s_exp turns off auto exposure */
1453 			return ov7670_s_exp(sd, info->exposure->val);
1454 		}
1455 		return ov7670_s_autoexp(sd, ctrl->val);
1456 	}
1457 	return -EINVAL;
1458 }
1459 
1460 static const struct v4l2_ctrl_ops ov7670_ctrl_ops = {
1461 	.s_ctrl = ov7670_s_ctrl,
1462 	.g_volatile_ctrl = ov7670_g_volatile_ctrl,
1463 };
1464 
1465 static int ov7670_g_chip_ident(struct v4l2_subdev *sd,
1466 		struct v4l2_dbg_chip_ident *chip)
1467 {
1468 	struct i2c_client *client = v4l2_get_subdevdata(sd);
1469 
1470 	return v4l2_chip_ident_i2c_client(client, chip, V4L2_IDENT_OV7670, 0);
1471 }
1472 
1473 #ifdef CONFIG_VIDEO_ADV_DEBUG
1474 static int ov7670_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
1475 {
1476 	struct i2c_client *client = v4l2_get_subdevdata(sd);
1477 	unsigned char val = 0;
1478 	int ret;
1479 
1480 	if (!v4l2_chip_match_i2c_client(client, &reg->match))
1481 		return -EINVAL;
1482 	if (!capable(CAP_SYS_ADMIN))
1483 		return -EPERM;
1484 	ret = ov7670_read(sd, reg->reg & 0xff, &val);
1485 	reg->val = val;
1486 	reg->size = 1;
1487 	return ret;
1488 }
1489 
1490 static int ov7670_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
1491 {
1492 	struct i2c_client *client = v4l2_get_subdevdata(sd);
1493 
1494 	if (!v4l2_chip_match_i2c_client(client, &reg->match))
1495 		return -EINVAL;
1496 	if (!capable(CAP_SYS_ADMIN))
1497 		return -EPERM;
1498 	ov7670_write(sd, reg->reg & 0xff, reg->val & 0xff);
1499 	return 0;
1500 }
1501 #endif
1502 
1503 /* ----------------------------------------------------------------------- */
1504 
1505 static const struct v4l2_subdev_core_ops ov7670_core_ops = {
1506 	.g_chip_ident = ov7670_g_chip_ident,
1507 	.reset = ov7670_reset,
1508 	.init = ov7670_init,
1509 #ifdef CONFIG_VIDEO_ADV_DEBUG
1510 	.g_register = ov7670_g_register,
1511 	.s_register = ov7670_s_register,
1512 #endif
1513 };
1514 
1515 static const struct v4l2_subdev_video_ops ov7670_video_ops = {
1516 	.enum_mbus_fmt = ov7670_enum_mbus_fmt,
1517 	.try_mbus_fmt = ov7670_try_mbus_fmt,
1518 	.s_mbus_fmt = ov7670_s_mbus_fmt,
1519 	.s_parm = ov7670_s_parm,
1520 	.g_parm = ov7670_g_parm,
1521 	.enum_frameintervals = ov7670_enum_frameintervals,
1522 	.enum_framesizes = ov7670_enum_framesizes,
1523 };
1524 
1525 static const struct v4l2_subdev_ops ov7670_ops = {
1526 	.core = &ov7670_core_ops,
1527 	.video = &ov7670_video_ops,
1528 };
1529 
1530 /* ----------------------------------------------------------------------- */
1531 
1532 static const struct ov7670_devtype ov7670_devdata[] = {
1533 	[MODEL_OV7670] = {
1534 		.win_sizes = ov7670_win_sizes,
1535 		.n_win_sizes = ARRAY_SIZE(ov7670_win_sizes),
1536 		.set_framerate = ov7670_set_framerate_legacy,
1537 		.get_framerate = ov7670_get_framerate_legacy,
1538 	},
1539 	[MODEL_OV7675] = {
1540 		.win_sizes = ov7675_win_sizes,
1541 		.n_win_sizes = ARRAY_SIZE(ov7675_win_sizes),
1542 		.set_framerate = ov7675_set_framerate,
1543 		.get_framerate = ov7675_get_framerate,
1544 	},
1545 };
1546 
1547 static int ov7670_probe(struct i2c_client *client,
1548 			const struct i2c_device_id *id)
1549 {
1550 	struct v4l2_fract tpf;
1551 	struct v4l2_subdev *sd;
1552 	struct ov7670_info *info;
1553 	int ret;
1554 
1555 	info = kzalloc(sizeof(struct ov7670_info), GFP_KERNEL);
1556 	if (info == NULL)
1557 		return -ENOMEM;
1558 	sd = &info->sd;
1559 	v4l2_i2c_subdev_init(sd, client, &ov7670_ops);
1560 
1561 	info->clock_speed = 30; /* default: a guess */
1562 	if (client->dev.platform_data) {
1563 		struct ov7670_config *config = client->dev.platform_data;
1564 
1565 		/*
1566 		 * Must apply configuration before initializing device, because it
1567 		 * selects I/O method.
1568 		 */
1569 		info->min_width = config->min_width;
1570 		info->min_height = config->min_height;
1571 		info->use_smbus = config->use_smbus;
1572 
1573 		if (config->clock_speed)
1574 			info->clock_speed = config->clock_speed;
1575 
1576 		/*
1577 		 * It should be allowed for ov7670 too when it is migrated to
1578 		 * the new frame rate formula.
1579 		 */
1580 		if (config->pll_bypass && id->driver_data != MODEL_OV7670)
1581 			info->pll_bypass = true;
1582 
1583 		if (config->pclk_hb_disable)
1584 			info->pclk_hb_disable = true;
1585 	}
1586 
1587 	/* Make sure it's an ov7670 */
1588 	ret = ov7670_detect(sd);
1589 	if (ret) {
1590 		v4l_dbg(1, debug, client,
1591 			"chip found @ 0x%x (%s) is not an ov7670 chip.\n",
1592 			client->addr << 1, client->adapter->name);
1593 		kfree(info);
1594 		return ret;
1595 	}
1596 	v4l_info(client, "chip found @ 0x%02x (%s)\n",
1597 			client->addr << 1, client->adapter->name);
1598 
1599 	info->devtype = &ov7670_devdata[id->driver_data];
1600 	info->fmt = &ov7670_formats[0];
1601 	info->clkrc = 0;
1602 
1603 	/* Set default frame rate to 30 fps */
1604 	tpf.numerator = 1;
1605 	tpf.denominator = 30;
1606 	info->devtype->set_framerate(sd, &tpf);
1607 
1608 	if (info->pclk_hb_disable)
1609 		ov7670_write(sd, REG_COM10, COM10_PCLK_HB);
1610 
1611 	v4l2_ctrl_handler_init(&info->hdl, 10);
1612 	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1613 			V4L2_CID_BRIGHTNESS, 0, 255, 1, 128);
1614 	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1615 			V4L2_CID_CONTRAST, 0, 127, 1, 64);
1616 	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1617 			V4L2_CID_VFLIP, 0, 1, 1, 0);
1618 	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1619 			V4L2_CID_HFLIP, 0, 1, 1, 0);
1620 	info->saturation = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1621 			V4L2_CID_SATURATION, 0, 256, 1, 128);
1622 	info->hue = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1623 			V4L2_CID_HUE, -180, 180, 5, 0);
1624 	info->gain = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1625 			V4L2_CID_GAIN, 0, 255, 1, 128);
1626 	info->auto_gain = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1627 			V4L2_CID_AUTOGAIN, 0, 1, 1, 1);
1628 	info->exposure = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1629 			V4L2_CID_EXPOSURE, 0, 65535, 1, 500);
1630 	info->auto_exposure = v4l2_ctrl_new_std_menu(&info->hdl, &ov7670_ctrl_ops,
1631 			V4L2_CID_EXPOSURE_AUTO, V4L2_EXPOSURE_MANUAL, 0,
1632 			V4L2_EXPOSURE_AUTO);
1633 	sd->ctrl_handler = &info->hdl;
1634 	if (info->hdl.error) {
1635 		int err = info->hdl.error;
1636 
1637 		v4l2_ctrl_handler_free(&info->hdl);
1638 		kfree(info);
1639 		return err;
1640 	}
1641 	/*
1642 	 * We have checked empirically that hw allows to read back the gain
1643 	 * value chosen by auto gain but that's not the case for auto exposure.
1644 	 */
1645 	v4l2_ctrl_auto_cluster(2, &info->auto_gain, 0, true);
1646 	v4l2_ctrl_auto_cluster(2, &info->auto_exposure,
1647 			       V4L2_EXPOSURE_MANUAL, false);
1648 	v4l2_ctrl_cluster(2, &info->saturation);
1649 	v4l2_ctrl_handler_setup(&info->hdl);
1650 
1651 	return 0;
1652 }
1653 
1654 
1655 static int ov7670_remove(struct i2c_client *client)
1656 {
1657 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
1658 	struct ov7670_info *info = to_state(sd);
1659 
1660 	v4l2_device_unregister_subdev(sd);
1661 	v4l2_ctrl_handler_free(&info->hdl);
1662 	kfree(info);
1663 	return 0;
1664 }
1665 
1666 static const struct i2c_device_id ov7670_id[] = {
1667 	{ "ov7670", MODEL_OV7670 },
1668 	{ "ov7675", MODEL_OV7675 },
1669 	{ }
1670 };
1671 MODULE_DEVICE_TABLE(i2c, ov7670_id);
1672 
1673 static struct i2c_driver ov7670_driver = {
1674 	.driver = {
1675 		.owner	= THIS_MODULE,
1676 		.name	= "ov7670",
1677 	},
1678 	.probe		= ov7670_probe,
1679 	.remove		= ov7670_remove,
1680 	.id_table	= ov7670_id,
1681 };
1682 
1683 module_i2c_driver(ov7670_driver);
1684