xref: /openbmc/linux/drivers/media/i2c/ov7670.c (revision 4f6cce39)
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-ctrls.h>
21 #include <media/v4l2-mediabus.h>
22 #include <media/v4l2-image-sizes.h>
23 #include <media/i2c/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  * The 7670 sits on i2c with ID 0x42
35  */
36 #define OV7670_I2C_ADDR 0x42
37 
38 #define PLL_FACTOR	4
39 
40 /* Registers */
41 #define REG_GAIN	0x00	/* Gain lower 8 bits (rest in vref) */
42 #define REG_BLUE	0x01	/* blue gain */
43 #define REG_RED		0x02	/* red gain */
44 #define REG_VREF	0x03	/* Pieces of GAIN, VSTART, VSTOP */
45 #define REG_COM1	0x04	/* Control 1 */
46 #define  COM1_CCIR656	  0x40  /* CCIR656 enable */
47 #define REG_BAVE	0x05	/* U/B Average level */
48 #define REG_GbAVE	0x06	/* Y/Gb Average level */
49 #define REG_AECHH	0x07	/* AEC MS 5 bits */
50 #define REG_RAVE	0x08	/* V/R Average level */
51 #define REG_COM2	0x09	/* Control 2 */
52 #define  COM2_SSLEEP	  0x10	/* Soft sleep mode */
53 #define REG_PID		0x0a	/* Product ID MSB */
54 #define REG_VER		0x0b	/* Product ID LSB */
55 #define REG_COM3	0x0c	/* Control 3 */
56 #define  COM3_SWAP	  0x40	  /* Byte swap */
57 #define  COM3_SCALEEN	  0x08	  /* Enable scaling */
58 #define  COM3_DCWEN	  0x04	  /* Enable downsamp/crop/window */
59 #define REG_COM4	0x0d	/* Control 4 */
60 #define REG_COM5	0x0e	/* All "reserved" */
61 #define REG_COM6	0x0f	/* Control 6 */
62 #define REG_AECH	0x10	/* More bits of AEC value */
63 #define REG_CLKRC	0x11	/* Clocl control */
64 #define   CLK_EXT	  0x40	  /* Use external clock directly */
65 #define   CLK_SCALE	  0x3f	  /* Mask for internal clock scale */
66 #define REG_COM7	0x12	/* Control 7 */
67 #define   COM7_RESET	  0x80	  /* Register reset */
68 #define   COM7_FMT_MASK	  0x38
69 #define   COM7_FMT_VGA	  0x00
70 #define	  COM7_FMT_CIF	  0x20	  /* CIF format */
71 #define   COM7_FMT_QVGA	  0x10	  /* QVGA format */
72 #define   COM7_FMT_QCIF	  0x08	  /* QCIF format */
73 #define	  COM7_RGB	  0x04	  /* bits 0 and 2 - RGB format */
74 #define	  COM7_YUV	  0x00	  /* YUV */
75 #define	  COM7_BAYER	  0x01	  /* Bayer format */
76 #define	  COM7_PBAYER	  0x05	  /* "Processed bayer" */
77 #define REG_COM8	0x13	/* Control 8 */
78 #define   COM8_FASTAEC	  0x80	  /* Enable fast AGC/AEC */
79 #define   COM8_AECSTEP	  0x40	  /* Unlimited AEC step size */
80 #define   COM8_BFILT	  0x20	  /* Band filter enable */
81 #define   COM8_AGC	  0x04	  /* Auto gain enable */
82 #define   COM8_AWB	  0x02	  /* White balance enable */
83 #define   COM8_AEC	  0x01	  /* Auto exposure enable */
84 #define REG_COM9	0x14	/* Control 9  - gain ceiling */
85 #define REG_COM10	0x15	/* Control 10 */
86 #define   COM10_HSYNC	  0x40	  /* HSYNC instead of HREF */
87 #define   COM10_PCLK_HB	  0x20	  /* Suppress PCLK on horiz blank */
88 #define   COM10_HREF_REV  0x08	  /* Reverse HREF */
89 #define   COM10_VS_LEAD	  0x04	  /* VSYNC on clock leading edge */
90 #define   COM10_VS_NEG	  0x02	  /* VSYNC negative */
91 #define   COM10_HS_NEG	  0x01	  /* HSYNC negative */
92 #define REG_HSTART	0x17	/* Horiz start high bits */
93 #define REG_HSTOP	0x18	/* Horiz stop high bits */
94 #define REG_VSTART	0x19	/* Vert start high bits */
95 #define REG_VSTOP	0x1a	/* Vert stop high bits */
96 #define REG_PSHFT	0x1b	/* Pixel delay after HREF */
97 #define REG_MIDH	0x1c	/* Manuf. ID high */
98 #define REG_MIDL	0x1d	/* Manuf. ID low */
99 #define REG_MVFP	0x1e	/* Mirror / vflip */
100 #define   MVFP_MIRROR	  0x20	  /* Mirror image */
101 #define   MVFP_FLIP	  0x10	  /* Vertical flip */
102 
103 #define REG_AEW		0x24	/* AGC upper limit */
104 #define REG_AEB		0x25	/* AGC lower limit */
105 #define REG_VPT		0x26	/* AGC/AEC fast mode op region */
106 #define REG_HSYST	0x30	/* HSYNC rising edge delay */
107 #define REG_HSYEN	0x31	/* HSYNC falling edge delay */
108 #define REG_HREF	0x32	/* HREF pieces */
109 #define REG_TSLB	0x3a	/* lots of stuff */
110 #define   TSLB_YLAST	  0x04	  /* UYVY or VYUY - see com13 */
111 #define REG_COM11	0x3b	/* Control 11 */
112 #define   COM11_NIGHT	  0x80	  /* NIght mode enable */
113 #define   COM11_NMFR	  0x60	  /* Two bit NM frame rate */
114 #define   COM11_HZAUTO	  0x10	  /* Auto detect 50/60 Hz */
115 #define	  COM11_50HZ	  0x08	  /* Manual 50Hz select */
116 #define   COM11_EXP	  0x02
117 #define REG_COM12	0x3c	/* Control 12 */
118 #define   COM12_HREF	  0x80	  /* HREF always */
119 #define REG_COM13	0x3d	/* Control 13 */
120 #define   COM13_GAMMA	  0x80	  /* Gamma enable */
121 #define	  COM13_UVSAT	  0x40	  /* UV saturation auto adjustment */
122 #define   COM13_UVSWAP	  0x01	  /* V before U - w/TSLB */
123 #define REG_COM14	0x3e	/* Control 14 */
124 #define   COM14_DCWEN	  0x10	  /* DCW/PCLK-scale enable */
125 #define REG_EDGE	0x3f	/* Edge enhancement factor */
126 #define REG_COM15	0x40	/* Control 15 */
127 #define   COM15_R10F0	  0x00	  /* Data range 10 to F0 */
128 #define	  COM15_R01FE	  0x80	  /*            01 to FE */
129 #define   COM15_R00FF	  0xc0	  /*            00 to FF */
130 #define   COM15_RGB565	  0x10	  /* RGB565 output */
131 #define   COM15_RGB555	  0x30	  /* RGB555 output */
132 #define REG_COM16	0x41	/* Control 16 */
133 #define   COM16_AWBGAIN   0x08	  /* AWB gain enable */
134 #define REG_COM17	0x42	/* Control 17 */
135 #define   COM17_AECWIN	  0xc0	  /* AEC window - must match COM4 */
136 #define   COM17_CBAR	  0x08	  /* DSP Color bar */
137 
138 /*
139  * This matrix defines how the colors are generated, must be
140  * tweaked to adjust hue and saturation.
141  *
142  * Order: v-red, v-green, v-blue, u-red, u-green, u-blue
143  *
144  * They are nine-bit signed quantities, with the sign bit
145  * stored in 0x58.  Sign for v-red is bit 0, and up from there.
146  */
147 #define	REG_CMATRIX_BASE 0x4f
148 #define   CMATRIX_LEN 6
149 #define REG_CMATRIX_SIGN 0x58
150 
151 
152 #define REG_BRIGHT	0x55	/* Brightness */
153 #define REG_CONTRAS	0x56	/* Contrast control */
154 
155 #define REG_GFIX	0x69	/* Fix gain control */
156 
157 #define REG_DBLV	0x6b	/* PLL control an debugging */
158 #define   DBLV_BYPASS	  0x00	  /* Bypass PLL */
159 #define   DBLV_X4	  0x01	  /* clock x4 */
160 #define   DBLV_X6	  0x10	  /* clock x6 */
161 #define   DBLV_X8	  0x11	  /* clock x8 */
162 
163 #define REG_REG76	0x76	/* OV's name */
164 #define   R76_BLKPCOR	  0x80	  /* Black pixel correction enable */
165 #define   R76_WHTPCOR	  0x40	  /* White pixel correction enable */
166 
167 #define REG_RGB444	0x8c	/* RGB 444 control */
168 #define   R444_ENABLE	  0x02	  /* Turn on RGB444, overrides 5x5 */
169 #define   R444_RGBX	  0x01	  /* Empty nibble at end */
170 
171 #define REG_HAECC1	0x9f	/* Hist AEC/AGC control 1 */
172 #define REG_HAECC2	0xa0	/* Hist AEC/AGC control 2 */
173 
174 #define REG_BD50MAX	0xa5	/* 50hz banding step limit */
175 #define REG_HAECC3	0xa6	/* Hist AEC/AGC control 3 */
176 #define REG_HAECC4	0xa7	/* Hist AEC/AGC control 4 */
177 #define REG_HAECC5	0xa8	/* Hist AEC/AGC control 5 */
178 #define REG_HAECC6	0xa9	/* Hist AEC/AGC control 6 */
179 #define REG_HAECC7	0xaa	/* Hist AEC/AGC control 7 */
180 #define REG_BD60MAX	0xab	/* 60hz banding step limit */
181 
182 enum ov7670_model {
183 	MODEL_OV7670 = 0,
184 	MODEL_OV7675,
185 };
186 
187 struct ov7670_win_size {
188 	int	width;
189 	int	height;
190 	unsigned char com7_bit;
191 	int	hstart;		/* Start/stop values for the camera.  Note */
192 	int	hstop;		/* that they do not always make complete */
193 	int	vstart;		/* sense to humans, but evidently the sensor */
194 	int	vstop;		/* will do the right thing... */
195 	struct regval_list *regs; /* Regs to tweak */
196 };
197 
198 struct ov7670_devtype {
199 	/* formats supported for each model */
200 	struct ov7670_win_size *win_sizes;
201 	unsigned int n_win_sizes;
202 	/* callbacks for frame rate control */
203 	int (*set_framerate)(struct v4l2_subdev *, struct v4l2_fract *);
204 	void (*get_framerate)(struct v4l2_subdev *, struct v4l2_fract *);
205 };
206 
207 /*
208  * Information we maintain about a known sensor.
209  */
210 struct ov7670_format_struct;  /* coming later */
211 struct ov7670_info {
212 	struct v4l2_subdev sd;
213 	struct v4l2_ctrl_handler hdl;
214 	struct {
215 		/* gain cluster */
216 		struct v4l2_ctrl *auto_gain;
217 		struct v4l2_ctrl *gain;
218 	};
219 	struct {
220 		/* exposure cluster */
221 		struct v4l2_ctrl *auto_exposure;
222 		struct v4l2_ctrl *exposure;
223 	};
224 	struct {
225 		/* saturation/hue cluster */
226 		struct v4l2_ctrl *saturation;
227 		struct v4l2_ctrl *hue;
228 	};
229 	struct ov7670_format_struct *fmt;  /* Current format */
230 	int min_width;			/* Filter out smaller sizes */
231 	int min_height;			/* Filter out smaller sizes */
232 	int clock_speed;		/* External clock speed (MHz) */
233 	u8 clkrc;			/* Clock divider value */
234 	bool use_smbus;			/* Use smbus I/O instead of I2C */
235 	bool pll_bypass;
236 	bool pclk_hb_disable;
237 	const struct ov7670_devtype *devtype; /* Device specifics */
238 };
239 
240 static inline struct ov7670_info *to_state(struct v4l2_subdev *sd)
241 {
242 	return container_of(sd, struct ov7670_info, sd);
243 }
244 
245 static inline struct v4l2_subdev *to_sd(struct v4l2_ctrl *ctrl)
246 {
247 	return &container_of(ctrl->handler, struct ov7670_info, hdl)->sd;
248 }
249 
250 
251 
252 /*
253  * The default register settings, as obtained from OmniVision.  There
254  * is really no making sense of most of these - lots of "reserved" values
255  * and such.
256  *
257  * These settings give VGA YUYV.
258  */
259 
260 struct regval_list {
261 	unsigned char reg_num;
262 	unsigned char value;
263 };
264 
265 static struct regval_list ov7670_default_regs[] = {
266 	{ REG_COM7, COM7_RESET },
267 /*
268  * Clock scale: 3 = 15fps
269  *              2 = 20fps
270  *              1 = 30fps
271  */
272 	{ REG_CLKRC, 0x1 },	/* OV: clock scale (30 fps) */
273 	{ REG_TSLB,  0x04 },	/* OV */
274 	{ REG_COM7, 0 },	/* VGA */
275 	/*
276 	 * Set the hardware window.  These values from OV don't entirely
277 	 * make sense - hstop is less than hstart.  But they work...
278 	 */
279 	{ REG_HSTART, 0x13 },	{ REG_HSTOP, 0x01 },
280 	{ REG_HREF, 0xb6 },	{ REG_VSTART, 0x02 },
281 	{ REG_VSTOP, 0x7a },	{ REG_VREF, 0x0a },
282 
283 	{ REG_COM3, 0 },	{ REG_COM14, 0 },
284 	/* Mystery scaling numbers */
285 	{ 0x70, 0x3a },		{ 0x71, 0x35 },
286 	{ 0x72, 0x11 },		{ 0x73, 0xf0 },
287 	{ 0xa2, 0x02 },		{ REG_COM10, 0x0 },
288 
289 	/* Gamma curve values */
290 	{ 0x7a, 0x20 },		{ 0x7b, 0x10 },
291 	{ 0x7c, 0x1e },		{ 0x7d, 0x35 },
292 	{ 0x7e, 0x5a },		{ 0x7f, 0x69 },
293 	{ 0x80, 0x76 },		{ 0x81, 0x80 },
294 	{ 0x82, 0x88 },		{ 0x83, 0x8f },
295 	{ 0x84, 0x96 },		{ 0x85, 0xa3 },
296 	{ 0x86, 0xaf },		{ 0x87, 0xc4 },
297 	{ 0x88, 0xd7 },		{ 0x89, 0xe8 },
298 
299 	/* AGC and AEC parameters.  Note we start by disabling those features,
300 	   then turn them only after tweaking the values. */
301 	{ REG_COM8, COM8_FASTAEC | COM8_AECSTEP | COM8_BFILT },
302 	{ REG_GAIN, 0 },	{ REG_AECH, 0 },
303 	{ REG_COM4, 0x40 }, /* magic reserved bit */
304 	{ REG_COM9, 0x18 }, /* 4x gain + magic rsvd bit */
305 	{ REG_BD50MAX, 0x05 },	{ REG_BD60MAX, 0x07 },
306 	{ REG_AEW, 0x95 },	{ REG_AEB, 0x33 },
307 	{ REG_VPT, 0xe3 },	{ REG_HAECC1, 0x78 },
308 	{ REG_HAECC2, 0x68 },	{ 0xa1, 0x03 }, /* magic */
309 	{ REG_HAECC3, 0xd8 },	{ REG_HAECC4, 0xd8 },
310 	{ REG_HAECC5, 0xf0 },	{ REG_HAECC6, 0x90 },
311 	{ REG_HAECC7, 0x94 },
312 	{ REG_COM8, COM8_FASTAEC|COM8_AECSTEP|COM8_BFILT|COM8_AGC|COM8_AEC },
313 
314 	/* Almost all of these are magic "reserved" values.  */
315 	{ REG_COM5, 0x61 },	{ REG_COM6, 0x4b },
316 	{ 0x16, 0x02 },		{ REG_MVFP, 0x07 },
317 	{ 0x21, 0x02 },		{ 0x22, 0x91 },
318 	{ 0x29, 0x07 },		{ 0x33, 0x0b },
319 	{ 0x35, 0x0b },		{ 0x37, 0x1d },
320 	{ 0x38, 0x71 },		{ 0x39, 0x2a },
321 	{ REG_COM12, 0x78 },	{ 0x4d, 0x40 },
322 	{ 0x4e, 0x20 },		{ REG_GFIX, 0 },
323 	{ 0x6b, 0x4a },		{ 0x74, 0x10 },
324 	{ 0x8d, 0x4f },		{ 0x8e, 0 },
325 	{ 0x8f, 0 },		{ 0x90, 0 },
326 	{ 0x91, 0 },		{ 0x96, 0 },
327 	{ 0x9a, 0 },		{ 0xb0, 0x84 },
328 	{ 0xb1, 0x0c },		{ 0xb2, 0x0e },
329 	{ 0xb3, 0x82 },		{ 0xb8, 0x0a },
330 
331 	/* More reserved magic, some of which tweaks white balance */
332 	{ 0x43, 0x0a },		{ 0x44, 0xf0 },
333 	{ 0x45, 0x34 },		{ 0x46, 0x58 },
334 	{ 0x47, 0x28 },		{ 0x48, 0x3a },
335 	{ 0x59, 0x88 },		{ 0x5a, 0x88 },
336 	{ 0x5b, 0x44 },		{ 0x5c, 0x67 },
337 	{ 0x5d, 0x49 },		{ 0x5e, 0x0e },
338 	{ 0x6c, 0x0a },		{ 0x6d, 0x55 },
339 	{ 0x6e, 0x11 },		{ 0x6f, 0x9f }, /* "9e for advance AWB" */
340 	{ 0x6a, 0x40 },		{ REG_BLUE, 0x40 },
341 	{ REG_RED, 0x60 },
342 	{ REG_COM8, COM8_FASTAEC|COM8_AECSTEP|COM8_BFILT|COM8_AGC|COM8_AEC|COM8_AWB },
343 
344 	/* Matrix coefficients */
345 	{ 0x4f, 0x80 },		{ 0x50, 0x80 },
346 	{ 0x51, 0 },		{ 0x52, 0x22 },
347 	{ 0x53, 0x5e },		{ 0x54, 0x80 },
348 	{ 0x58, 0x9e },
349 
350 	{ REG_COM16, COM16_AWBGAIN },	{ REG_EDGE, 0 },
351 	{ 0x75, 0x05 },		{ 0x76, 0xe1 },
352 	{ 0x4c, 0 },		{ 0x77, 0x01 },
353 	{ REG_COM13, 0xc3 },	{ 0x4b, 0x09 },
354 	{ 0xc9, 0x60 },		{ REG_COM16, 0x38 },
355 	{ 0x56, 0x40 },
356 
357 	{ 0x34, 0x11 },		{ REG_COM11, COM11_EXP|COM11_HZAUTO },
358 	{ 0xa4, 0x88 },		{ 0x96, 0 },
359 	{ 0x97, 0x30 },		{ 0x98, 0x20 },
360 	{ 0x99, 0x30 },		{ 0x9a, 0x84 },
361 	{ 0x9b, 0x29 },		{ 0x9c, 0x03 },
362 	{ 0x9d, 0x4c },		{ 0x9e, 0x3f },
363 	{ 0x78, 0x04 },
364 
365 	/* Extra-weird stuff.  Some sort of multiplexor register */
366 	{ 0x79, 0x01 },		{ 0xc8, 0xf0 },
367 	{ 0x79, 0x0f },		{ 0xc8, 0x00 },
368 	{ 0x79, 0x10 },		{ 0xc8, 0x7e },
369 	{ 0x79, 0x0a },		{ 0xc8, 0x80 },
370 	{ 0x79, 0x0b },		{ 0xc8, 0x01 },
371 	{ 0x79, 0x0c },		{ 0xc8, 0x0f },
372 	{ 0x79, 0x0d },		{ 0xc8, 0x20 },
373 	{ 0x79, 0x09 },		{ 0xc8, 0x80 },
374 	{ 0x79, 0x02 },		{ 0xc8, 0xc0 },
375 	{ 0x79, 0x03 },		{ 0xc8, 0x40 },
376 	{ 0x79, 0x05 },		{ 0xc8, 0x30 },
377 	{ 0x79, 0x26 },
378 
379 	{ 0xff, 0xff },	/* END MARKER */
380 };
381 
382 
383 /*
384  * Here we'll try to encapsulate the changes for just the output
385  * video format.
386  *
387  * RGB656 and YUV422 come from OV; RGB444 is homebrewed.
388  *
389  * IMPORTANT RULE: the first entry must be for COM7, see ov7670_s_fmt for why.
390  */
391 
392 
393 static struct regval_list ov7670_fmt_yuv422[] = {
394 	{ REG_COM7, 0x0 },  /* Selects YUV mode */
395 	{ REG_RGB444, 0 },	/* No RGB444 please */
396 	{ REG_COM1, 0 },	/* CCIR601 */
397 	{ REG_COM15, COM15_R00FF },
398 	{ REG_COM9, 0x48 }, /* 32x gain ceiling; 0x8 is reserved bit */
399 	{ 0x4f, 0x80 }, 	/* "matrix coefficient 1" */
400 	{ 0x50, 0x80 }, 	/* "matrix coefficient 2" */
401 	{ 0x51, 0    },		/* vb */
402 	{ 0x52, 0x22 }, 	/* "matrix coefficient 4" */
403 	{ 0x53, 0x5e }, 	/* "matrix coefficient 5" */
404 	{ 0x54, 0x80 }, 	/* "matrix coefficient 6" */
405 	{ REG_COM13, COM13_GAMMA|COM13_UVSAT },
406 	{ 0xff, 0xff },
407 };
408 
409 static struct regval_list ov7670_fmt_rgb565[] = {
410 	{ REG_COM7, COM7_RGB },	/* Selects RGB mode */
411 	{ REG_RGB444, 0 },	/* No RGB444 please */
412 	{ REG_COM1, 0x0 },	/* CCIR601 */
413 	{ REG_COM15, COM15_RGB565 },
414 	{ REG_COM9, 0x38 }, 	/* 16x gain ceiling; 0x8 is reserved bit */
415 	{ 0x4f, 0xb3 }, 	/* "matrix coefficient 1" */
416 	{ 0x50, 0xb3 }, 	/* "matrix coefficient 2" */
417 	{ 0x51, 0    },		/* vb */
418 	{ 0x52, 0x3d }, 	/* "matrix coefficient 4" */
419 	{ 0x53, 0xa7 }, 	/* "matrix coefficient 5" */
420 	{ 0x54, 0xe4 }, 	/* "matrix coefficient 6" */
421 	{ REG_COM13, COM13_GAMMA|COM13_UVSAT },
422 	{ 0xff, 0xff },
423 };
424 
425 static struct regval_list ov7670_fmt_rgb444[] = {
426 	{ REG_COM7, COM7_RGB },	/* Selects RGB mode */
427 	{ REG_RGB444, R444_ENABLE },	/* Enable xxxxrrrr ggggbbbb */
428 	{ REG_COM1, 0x0 },	/* CCIR601 */
429 	{ REG_COM15, COM15_R01FE|COM15_RGB565 }, /* Data range needed? */
430 	{ REG_COM9, 0x38 }, 	/* 16x gain ceiling; 0x8 is reserved bit */
431 	{ 0x4f, 0xb3 }, 	/* "matrix coefficient 1" */
432 	{ 0x50, 0xb3 }, 	/* "matrix coefficient 2" */
433 	{ 0x51, 0    },		/* vb */
434 	{ 0x52, 0x3d }, 	/* "matrix coefficient 4" */
435 	{ 0x53, 0xa7 }, 	/* "matrix coefficient 5" */
436 	{ 0x54, 0xe4 }, 	/* "matrix coefficient 6" */
437 	{ REG_COM13, COM13_GAMMA|COM13_UVSAT|0x2 },  /* Magic rsvd bit */
438 	{ 0xff, 0xff },
439 };
440 
441 static struct regval_list ov7670_fmt_raw[] = {
442 	{ REG_COM7, COM7_BAYER },
443 	{ REG_COM13, 0x08 }, /* No gamma, magic rsvd bit */
444 	{ REG_COM16, 0x3d }, /* Edge enhancement, denoise */
445 	{ REG_REG76, 0xe1 }, /* Pix correction, magic rsvd */
446 	{ 0xff, 0xff },
447 };
448 
449 
450 
451 /*
452  * Low-level register I/O.
453  *
454  * Note that there are two versions of these.  On the XO 1, the
455  * i2c controller only does SMBUS, so that's what we use.  The
456  * ov7670 is not really an SMBUS device, though, so the communication
457  * is not always entirely reliable.
458  */
459 static int ov7670_read_smbus(struct v4l2_subdev *sd, unsigned char reg,
460 		unsigned char *value)
461 {
462 	struct i2c_client *client = v4l2_get_subdevdata(sd);
463 	int ret;
464 
465 	ret = i2c_smbus_read_byte_data(client, reg);
466 	if (ret >= 0) {
467 		*value = (unsigned char)ret;
468 		ret = 0;
469 	}
470 	return ret;
471 }
472 
473 
474 static int ov7670_write_smbus(struct v4l2_subdev *sd, unsigned char reg,
475 		unsigned char value)
476 {
477 	struct i2c_client *client = v4l2_get_subdevdata(sd);
478 	int ret = i2c_smbus_write_byte_data(client, reg, value);
479 
480 	if (reg == REG_COM7 && (value & COM7_RESET))
481 		msleep(5);  /* Wait for reset to run */
482 	return ret;
483 }
484 
485 /*
486  * On most platforms, we'd rather do straight i2c I/O.
487  */
488 static int ov7670_read_i2c(struct v4l2_subdev *sd, unsigned char reg,
489 		unsigned char *value)
490 {
491 	struct i2c_client *client = v4l2_get_subdevdata(sd);
492 	u8 data = reg;
493 	struct i2c_msg msg;
494 	int ret;
495 
496 	/*
497 	 * Send out the register address...
498 	 */
499 	msg.addr = client->addr;
500 	msg.flags = 0;
501 	msg.len = 1;
502 	msg.buf = &data;
503 	ret = i2c_transfer(client->adapter, &msg, 1);
504 	if (ret < 0) {
505 		printk(KERN_ERR "Error %d on register write\n", ret);
506 		return ret;
507 	}
508 	/*
509 	 * ...then read back the result.
510 	 */
511 	msg.flags = I2C_M_RD;
512 	ret = i2c_transfer(client->adapter, &msg, 1);
513 	if (ret >= 0) {
514 		*value = data;
515 		ret = 0;
516 	}
517 	return ret;
518 }
519 
520 
521 static int ov7670_write_i2c(struct v4l2_subdev *sd, unsigned char reg,
522 		unsigned char value)
523 {
524 	struct i2c_client *client = v4l2_get_subdevdata(sd);
525 	struct i2c_msg msg;
526 	unsigned char data[2] = { reg, value };
527 	int ret;
528 
529 	msg.addr = client->addr;
530 	msg.flags = 0;
531 	msg.len = 2;
532 	msg.buf = data;
533 	ret = i2c_transfer(client->adapter, &msg, 1);
534 	if (ret > 0)
535 		ret = 0;
536 	if (reg == REG_COM7 && (value & COM7_RESET))
537 		msleep(5);  /* Wait for reset to run */
538 	return ret;
539 }
540 
541 static int ov7670_read(struct v4l2_subdev *sd, unsigned char reg,
542 		unsigned char *value)
543 {
544 	struct ov7670_info *info = to_state(sd);
545 	if (info->use_smbus)
546 		return ov7670_read_smbus(sd, reg, value);
547 	else
548 		return ov7670_read_i2c(sd, reg, value);
549 }
550 
551 static int ov7670_write(struct v4l2_subdev *sd, unsigned char reg,
552 		unsigned char value)
553 {
554 	struct ov7670_info *info = to_state(sd);
555 	if (info->use_smbus)
556 		return ov7670_write_smbus(sd, reg, value);
557 	else
558 		return ov7670_write_i2c(sd, reg, value);
559 }
560 
561 /*
562  * Write a list of register settings; ff/ff stops the process.
563  */
564 static int ov7670_write_array(struct v4l2_subdev *sd, struct regval_list *vals)
565 {
566 	while (vals->reg_num != 0xff || vals->value != 0xff) {
567 		int ret = ov7670_write(sd, vals->reg_num, vals->value);
568 		if (ret < 0)
569 			return ret;
570 		vals++;
571 	}
572 	return 0;
573 }
574 
575 
576 /*
577  * Stuff that knows about the sensor.
578  */
579 static int ov7670_reset(struct v4l2_subdev *sd, u32 val)
580 {
581 	ov7670_write(sd, REG_COM7, COM7_RESET);
582 	msleep(1);
583 	return 0;
584 }
585 
586 
587 static int ov7670_init(struct v4l2_subdev *sd, u32 val)
588 {
589 	return ov7670_write_array(sd, ov7670_default_regs);
590 }
591 
592 
593 
594 static int ov7670_detect(struct v4l2_subdev *sd)
595 {
596 	unsigned char v;
597 	int ret;
598 
599 	ret = ov7670_init(sd, 0);
600 	if (ret < 0)
601 		return ret;
602 	ret = ov7670_read(sd, REG_MIDH, &v);
603 	if (ret < 0)
604 		return ret;
605 	if (v != 0x7f) /* OV manuf. id. */
606 		return -ENODEV;
607 	ret = ov7670_read(sd, REG_MIDL, &v);
608 	if (ret < 0)
609 		return ret;
610 	if (v != 0xa2)
611 		return -ENODEV;
612 	/*
613 	 * OK, we know we have an OmniVision chip...but which one?
614 	 */
615 	ret = ov7670_read(sd, REG_PID, &v);
616 	if (ret < 0)
617 		return ret;
618 	if (v != 0x76)  /* PID + VER = 0x76 / 0x73 */
619 		return -ENODEV;
620 	ret = ov7670_read(sd, REG_VER, &v);
621 	if (ret < 0)
622 		return ret;
623 	if (v != 0x73)  /* PID + VER = 0x76 / 0x73 */
624 		return -ENODEV;
625 	return 0;
626 }
627 
628 
629 /*
630  * Store information about the video data format.  The color matrix
631  * is deeply tied into the format, so keep the relevant values here.
632  * The magic matrix numbers come from OmniVision.
633  */
634 static struct ov7670_format_struct {
635 	u32 mbus_code;
636 	enum v4l2_colorspace colorspace;
637 	struct regval_list *regs;
638 	int cmatrix[CMATRIX_LEN];
639 } ov7670_formats[] = {
640 	{
641 		.mbus_code	= MEDIA_BUS_FMT_YUYV8_2X8,
642 		.colorspace	= V4L2_COLORSPACE_SRGB,
643 		.regs 		= ov7670_fmt_yuv422,
644 		.cmatrix	= { 128, -128, 0, -34, -94, 128 },
645 	},
646 	{
647 		.mbus_code	= MEDIA_BUS_FMT_RGB444_2X8_PADHI_LE,
648 		.colorspace	= V4L2_COLORSPACE_SRGB,
649 		.regs		= ov7670_fmt_rgb444,
650 		.cmatrix	= { 179, -179, 0, -61, -176, 228 },
651 	},
652 	{
653 		.mbus_code	= MEDIA_BUS_FMT_RGB565_2X8_LE,
654 		.colorspace	= V4L2_COLORSPACE_SRGB,
655 		.regs		= ov7670_fmt_rgb565,
656 		.cmatrix	= { 179, -179, 0, -61, -176, 228 },
657 	},
658 	{
659 		.mbus_code	= MEDIA_BUS_FMT_SBGGR8_1X8,
660 		.colorspace	= V4L2_COLORSPACE_SRGB,
661 		.regs 		= ov7670_fmt_raw,
662 		.cmatrix	= { 0, 0, 0, 0, 0, 0 },
663 	},
664 };
665 #define N_OV7670_FMTS ARRAY_SIZE(ov7670_formats)
666 
667 
668 /*
669  * Then there is the issue of window sizes.  Try to capture the info here.
670  */
671 
672 /*
673  * QCIF mode is done (by OV) in a very strange way - it actually looks like
674  * VGA with weird scaling options - they do *not* use the canned QCIF mode
675  * which is allegedly provided by the sensor.  So here's the weird register
676  * settings.
677  */
678 static struct regval_list ov7670_qcif_regs[] = {
679 	{ REG_COM3, COM3_SCALEEN|COM3_DCWEN },
680 	{ REG_COM3, COM3_DCWEN },
681 	{ REG_COM14, COM14_DCWEN | 0x01},
682 	{ 0x73, 0xf1 },
683 	{ 0xa2, 0x52 },
684 	{ 0x7b, 0x1c },
685 	{ 0x7c, 0x28 },
686 	{ 0x7d, 0x3c },
687 	{ 0x7f, 0x69 },
688 	{ REG_COM9, 0x38 },
689 	{ 0xa1, 0x0b },
690 	{ 0x74, 0x19 },
691 	{ 0x9a, 0x80 },
692 	{ 0x43, 0x14 },
693 	{ REG_COM13, 0xc0 },
694 	{ 0xff, 0xff },
695 };
696 
697 static struct ov7670_win_size ov7670_win_sizes[] = {
698 	/* VGA */
699 	{
700 		.width		= VGA_WIDTH,
701 		.height		= VGA_HEIGHT,
702 		.com7_bit	= COM7_FMT_VGA,
703 		.hstart		= 158,	/* These values from */
704 		.hstop		=  14,	/* Omnivision */
705 		.vstart		=  10,
706 		.vstop		= 490,
707 		.regs		= NULL,
708 	},
709 	/* CIF */
710 	{
711 		.width		= CIF_WIDTH,
712 		.height		= CIF_HEIGHT,
713 		.com7_bit	= COM7_FMT_CIF,
714 		.hstart		= 170,	/* Empirically determined */
715 		.hstop		=  90,
716 		.vstart		=  14,
717 		.vstop		= 494,
718 		.regs		= NULL,
719 	},
720 	/* QVGA */
721 	{
722 		.width		= QVGA_WIDTH,
723 		.height		= QVGA_HEIGHT,
724 		.com7_bit	= COM7_FMT_QVGA,
725 		.hstart		= 168,	/* Empirically determined */
726 		.hstop		=  24,
727 		.vstart		=  12,
728 		.vstop		= 492,
729 		.regs		= NULL,
730 	},
731 	/* QCIF */
732 	{
733 		.width		= QCIF_WIDTH,
734 		.height		= QCIF_HEIGHT,
735 		.com7_bit	= COM7_FMT_VGA, /* see comment above */
736 		.hstart		= 456,	/* Empirically determined */
737 		.hstop		=  24,
738 		.vstart		=  14,
739 		.vstop		= 494,
740 		.regs		= ov7670_qcif_regs,
741 	}
742 };
743 
744 static struct ov7670_win_size ov7675_win_sizes[] = {
745 	/*
746 	 * Currently, only VGA is supported. Theoretically it could be possible
747 	 * to support CIF, QVGA and QCIF too. Taking values for ov7670 as a
748 	 * base and tweak them empirically could be required.
749 	 */
750 	{
751 		.width		= VGA_WIDTH,
752 		.height		= VGA_HEIGHT,
753 		.com7_bit	= COM7_FMT_VGA,
754 		.hstart		= 158,	/* These values from */
755 		.hstop		=  14,	/* Omnivision */
756 		.vstart		=  14,  /* Empirically determined */
757 		.vstop		= 494,
758 		.regs		= NULL,
759 	}
760 };
761 
762 static void ov7675_get_framerate(struct v4l2_subdev *sd,
763 				 struct v4l2_fract *tpf)
764 {
765 	struct ov7670_info *info = to_state(sd);
766 	u32 clkrc = info->clkrc;
767 	int pll_factor;
768 
769 	if (info->pll_bypass)
770 		pll_factor = 1;
771 	else
772 		pll_factor = PLL_FACTOR;
773 
774 	clkrc++;
775 	if (info->fmt->mbus_code == MEDIA_BUS_FMT_SBGGR8_1X8)
776 		clkrc = (clkrc >> 1);
777 
778 	tpf->numerator = 1;
779 	tpf->denominator = (5 * pll_factor * info->clock_speed) /
780 			(4 * clkrc);
781 }
782 
783 static int ov7675_set_framerate(struct v4l2_subdev *sd,
784 				 struct v4l2_fract *tpf)
785 {
786 	struct ov7670_info *info = to_state(sd);
787 	u32 clkrc;
788 	int pll_factor;
789 	int ret;
790 
791 	/*
792 	 * The formula is fps = 5/4*pixclk for YUV/RGB and
793 	 * fps = 5/2*pixclk for RAW.
794 	 *
795 	 * pixclk = clock_speed / (clkrc + 1) * PLLfactor
796 	 *
797 	 */
798 	if (info->pll_bypass) {
799 		pll_factor = 1;
800 		ret = ov7670_write(sd, REG_DBLV, DBLV_BYPASS);
801 	} else {
802 		pll_factor = PLL_FACTOR;
803 		ret = ov7670_write(sd, REG_DBLV, DBLV_X4);
804 	}
805 	if (ret < 0)
806 		return ret;
807 
808 	if (tpf->numerator == 0 || tpf->denominator == 0) {
809 		clkrc = 0;
810 	} else {
811 		clkrc = (5 * pll_factor * info->clock_speed * tpf->numerator) /
812 			(4 * tpf->denominator);
813 		if (info->fmt->mbus_code == MEDIA_BUS_FMT_SBGGR8_1X8)
814 			clkrc = (clkrc << 1);
815 		clkrc--;
816 	}
817 
818 	/*
819 	 * The datasheet claims that clkrc = 0 will divide the input clock by 1
820 	 * but we've checked with an oscilloscope that it divides by 2 instead.
821 	 * So, if clkrc = 0 just bypass the divider.
822 	 */
823 	if (clkrc <= 0)
824 		clkrc = CLK_EXT;
825 	else if (clkrc > CLK_SCALE)
826 		clkrc = CLK_SCALE;
827 	info->clkrc = clkrc;
828 
829 	/* Recalculate frame rate */
830 	ov7675_get_framerate(sd, tpf);
831 
832 	ret = ov7670_write(sd, REG_CLKRC, info->clkrc);
833 	if (ret < 0)
834 		return ret;
835 
836 	return ov7670_write(sd, REG_DBLV, DBLV_X4);
837 }
838 
839 static void ov7670_get_framerate_legacy(struct v4l2_subdev *sd,
840 				 struct v4l2_fract *tpf)
841 {
842 	struct ov7670_info *info = to_state(sd);
843 
844 	tpf->numerator = 1;
845 	tpf->denominator = info->clock_speed;
846 	if ((info->clkrc & CLK_EXT) == 0 && (info->clkrc & CLK_SCALE) > 1)
847 		tpf->denominator /= (info->clkrc & CLK_SCALE);
848 }
849 
850 static int ov7670_set_framerate_legacy(struct v4l2_subdev *sd,
851 					struct v4l2_fract *tpf)
852 {
853 	struct ov7670_info *info = to_state(sd);
854 	int div;
855 
856 	if (tpf->numerator == 0 || tpf->denominator == 0)
857 		div = 1;  /* Reset to full rate */
858 	else
859 		div = (tpf->numerator * info->clock_speed) / tpf->denominator;
860 	if (div == 0)
861 		div = 1;
862 	else if (div > CLK_SCALE)
863 		div = CLK_SCALE;
864 	info->clkrc = (info->clkrc & 0x80) | div;
865 	tpf->numerator = 1;
866 	tpf->denominator = info->clock_speed / div;
867 	return ov7670_write(sd, REG_CLKRC, info->clkrc);
868 }
869 
870 /*
871  * Store a set of start/stop values into the camera.
872  */
873 static int ov7670_set_hw(struct v4l2_subdev *sd, int hstart, int hstop,
874 		int vstart, int vstop)
875 {
876 	int ret;
877 	unsigned char v;
878 /*
879  * Horizontal: 11 bits, top 8 live in hstart and hstop.  Bottom 3 of
880  * hstart are in href[2:0], bottom 3 of hstop in href[5:3].  There is
881  * a mystery "edge offset" value in the top two bits of href.
882  */
883 	ret =  ov7670_write(sd, REG_HSTART, (hstart >> 3) & 0xff);
884 	ret += ov7670_write(sd, REG_HSTOP, (hstop >> 3) & 0xff);
885 	ret += ov7670_read(sd, REG_HREF, &v);
886 	v = (v & 0xc0) | ((hstop & 0x7) << 3) | (hstart & 0x7);
887 	msleep(10);
888 	ret += ov7670_write(sd, REG_HREF, v);
889 /*
890  * Vertical: similar arrangement, but only 10 bits.
891  */
892 	ret += ov7670_write(sd, REG_VSTART, (vstart >> 2) & 0xff);
893 	ret += ov7670_write(sd, REG_VSTOP, (vstop >> 2) & 0xff);
894 	ret += ov7670_read(sd, REG_VREF, &v);
895 	v = (v & 0xf0) | ((vstop & 0x3) << 2) | (vstart & 0x3);
896 	msleep(10);
897 	ret += ov7670_write(sd, REG_VREF, v);
898 	return ret;
899 }
900 
901 
902 static int ov7670_enum_mbus_code(struct v4l2_subdev *sd,
903 		struct v4l2_subdev_pad_config *cfg,
904 		struct v4l2_subdev_mbus_code_enum *code)
905 {
906 	if (code->pad || code->index >= N_OV7670_FMTS)
907 		return -EINVAL;
908 
909 	code->code = ov7670_formats[code->index].mbus_code;
910 	return 0;
911 }
912 
913 static int ov7670_try_fmt_internal(struct v4l2_subdev *sd,
914 		struct v4l2_mbus_framefmt *fmt,
915 		struct ov7670_format_struct **ret_fmt,
916 		struct ov7670_win_size **ret_wsize)
917 {
918 	int index, i;
919 	struct ov7670_win_size *wsize;
920 	struct ov7670_info *info = to_state(sd);
921 	unsigned int n_win_sizes = info->devtype->n_win_sizes;
922 	unsigned int win_sizes_limit = n_win_sizes;
923 
924 	for (index = 0; index < N_OV7670_FMTS; index++)
925 		if (ov7670_formats[index].mbus_code == fmt->code)
926 			break;
927 	if (index >= N_OV7670_FMTS) {
928 		/* default to first format */
929 		index = 0;
930 		fmt->code = ov7670_formats[0].mbus_code;
931 	}
932 	if (ret_fmt != NULL)
933 		*ret_fmt = ov7670_formats + index;
934 	/*
935 	 * Fields: the OV devices claim to be progressive.
936 	 */
937 	fmt->field = V4L2_FIELD_NONE;
938 
939 	/*
940 	 * Don't consider values that don't match min_height and min_width
941 	 * constraints.
942 	 */
943 	if (info->min_width || info->min_height)
944 		for (i = 0; i < n_win_sizes; i++) {
945 			wsize = info->devtype->win_sizes + i;
946 
947 			if (wsize->width < info->min_width ||
948 				wsize->height < info->min_height) {
949 				win_sizes_limit = i;
950 				break;
951 			}
952 		}
953 	/*
954 	 * Round requested image size down to the nearest
955 	 * we support, but not below the smallest.
956 	 */
957 	for (wsize = info->devtype->win_sizes;
958 	     wsize < info->devtype->win_sizes + win_sizes_limit; wsize++)
959 		if (fmt->width >= wsize->width && fmt->height >= wsize->height)
960 			break;
961 	if (wsize >= info->devtype->win_sizes + win_sizes_limit)
962 		wsize--;   /* Take the smallest one */
963 	if (ret_wsize != NULL)
964 		*ret_wsize = wsize;
965 	/*
966 	 * Note the size we'll actually handle.
967 	 */
968 	fmt->width = wsize->width;
969 	fmt->height = wsize->height;
970 	fmt->colorspace = ov7670_formats[index].colorspace;
971 	return 0;
972 }
973 
974 /*
975  * Set a format.
976  */
977 static int ov7670_set_fmt(struct v4l2_subdev *sd,
978 		struct v4l2_subdev_pad_config *cfg,
979 		struct v4l2_subdev_format *format)
980 {
981 	struct ov7670_format_struct *ovfmt;
982 	struct ov7670_win_size *wsize;
983 	struct ov7670_info *info = to_state(sd);
984 	unsigned char com7;
985 	int ret;
986 
987 	if (format->pad)
988 		return -EINVAL;
989 
990 	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
991 		ret = ov7670_try_fmt_internal(sd, &format->format, NULL, NULL);
992 		if (ret)
993 			return ret;
994 		cfg->try_fmt = format->format;
995 		return 0;
996 	}
997 
998 	ret = ov7670_try_fmt_internal(sd, &format->format, &ovfmt, &wsize);
999 
1000 	if (ret)
1001 		return ret;
1002 	/*
1003 	 * COM7 is a pain in the ass, it doesn't like to be read then
1004 	 * quickly written afterward.  But we have everything we need
1005 	 * to set it absolutely here, as long as the format-specific
1006 	 * register sets list it first.
1007 	 */
1008 	com7 = ovfmt->regs[0].value;
1009 	com7 |= wsize->com7_bit;
1010 	ov7670_write(sd, REG_COM7, com7);
1011 	/*
1012 	 * Now write the rest of the array.  Also store start/stops
1013 	 */
1014 	ov7670_write_array(sd, ovfmt->regs + 1);
1015 	ov7670_set_hw(sd, wsize->hstart, wsize->hstop, wsize->vstart,
1016 			wsize->vstop);
1017 	ret = 0;
1018 	if (wsize->regs)
1019 		ret = ov7670_write_array(sd, wsize->regs);
1020 	info->fmt = ovfmt;
1021 
1022 	/*
1023 	 * If we're running RGB565, we must rewrite clkrc after setting
1024 	 * the other parameters or the image looks poor.  If we're *not*
1025 	 * doing RGB565, we must not rewrite clkrc or the image looks
1026 	 * *really* poor.
1027 	 *
1028 	 * (Update) Now that we retain clkrc state, we should be able
1029 	 * to write it unconditionally, and that will make the frame
1030 	 * rate persistent too.
1031 	 */
1032 	if (ret == 0)
1033 		ret = ov7670_write(sd, REG_CLKRC, info->clkrc);
1034 	return 0;
1035 }
1036 
1037 /*
1038  * Implement G/S_PARM.  There is a "high quality" mode we could try
1039  * to do someday; for now, we just do the frame rate tweak.
1040  */
1041 static int ov7670_g_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
1042 {
1043 	struct v4l2_captureparm *cp = &parms->parm.capture;
1044 	struct ov7670_info *info = to_state(sd);
1045 
1046 	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1047 		return -EINVAL;
1048 
1049 	memset(cp, 0, sizeof(struct v4l2_captureparm));
1050 	cp->capability = V4L2_CAP_TIMEPERFRAME;
1051 	info->devtype->get_framerate(sd, &cp->timeperframe);
1052 
1053 	return 0;
1054 }
1055 
1056 static int ov7670_s_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
1057 {
1058 	struct v4l2_captureparm *cp = &parms->parm.capture;
1059 	struct v4l2_fract *tpf = &cp->timeperframe;
1060 	struct ov7670_info *info = to_state(sd);
1061 
1062 	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1063 		return -EINVAL;
1064 	if (cp->extendedmode != 0)
1065 		return -EINVAL;
1066 
1067 	return info->devtype->set_framerate(sd, tpf);
1068 }
1069 
1070 
1071 /*
1072  * Frame intervals.  Since frame rates are controlled with the clock
1073  * divider, we can only do 30/n for integer n values.  So no continuous
1074  * or stepwise options.  Here we just pick a handful of logical values.
1075  */
1076 
1077 static int ov7670_frame_rates[] = { 30, 15, 10, 5, 1 };
1078 
1079 static int ov7670_enum_frame_interval(struct v4l2_subdev *sd,
1080 				      struct v4l2_subdev_pad_config *cfg,
1081 				      struct v4l2_subdev_frame_interval_enum *fie)
1082 {
1083 	struct ov7670_info *info = to_state(sd);
1084 	unsigned int n_win_sizes = info->devtype->n_win_sizes;
1085 	int i;
1086 
1087 	if (fie->pad)
1088 		return -EINVAL;
1089 	if (fie->index >= ARRAY_SIZE(ov7670_frame_rates))
1090 		return -EINVAL;
1091 
1092 	/*
1093 	 * Check if the width/height is valid.
1094 	 *
1095 	 * If a minimum width/height was requested, filter out the capture
1096 	 * windows that fall outside that.
1097 	 */
1098 	for (i = 0; i < n_win_sizes; i++) {
1099 		struct ov7670_win_size *win = &info->devtype->win_sizes[i];
1100 
1101 		if (info->min_width && win->width < info->min_width)
1102 			continue;
1103 		if (info->min_height && win->height < info->min_height)
1104 			continue;
1105 		if (fie->width == win->width && fie->height == win->height)
1106 			break;
1107 	}
1108 	if (i == n_win_sizes)
1109 		return -EINVAL;
1110 	fie->interval.numerator = 1;
1111 	fie->interval.denominator = ov7670_frame_rates[fie->index];
1112 	return 0;
1113 }
1114 
1115 /*
1116  * Frame size enumeration
1117  */
1118 static int ov7670_enum_frame_size(struct v4l2_subdev *sd,
1119 				  struct v4l2_subdev_pad_config *cfg,
1120 				  struct v4l2_subdev_frame_size_enum *fse)
1121 {
1122 	struct ov7670_info *info = to_state(sd);
1123 	int i;
1124 	int num_valid = -1;
1125 	__u32 index = fse->index;
1126 	unsigned int n_win_sizes = info->devtype->n_win_sizes;
1127 
1128 	if (fse->pad)
1129 		return -EINVAL;
1130 
1131 	/*
1132 	 * If a minimum width/height was requested, filter out the capture
1133 	 * windows that fall outside that.
1134 	 */
1135 	for (i = 0; i < n_win_sizes; i++) {
1136 		struct ov7670_win_size *win = &info->devtype->win_sizes[i];
1137 		if (info->min_width && win->width < info->min_width)
1138 			continue;
1139 		if (info->min_height && win->height < info->min_height)
1140 			continue;
1141 		if (index == ++num_valid) {
1142 			fse->min_width = fse->max_width = win->width;
1143 			fse->min_height = fse->max_height = win->height;
1144 			return 0;
1145 		}
1146 	}
1147 
1148 	return -EINVAL;
1149 }
1150 
1151 /*
1152  * Code for dealing with controls.
1153  */
1154 
1155 static int ov7670_store_cmatrix(struct v4l2_subdev *sd,
1156 		int matrix[CMATRIX_LEN])
1157 {
1158 	int i, ret;
1159 	unsigned char signbits = 0;
1160 
1161 	/*
1162 	 * Weird crap seems to exist in the upper part of
1163 	 * the sign bits register, so let's preserve it.
1164 	 */
1165 	ret = ov7670_read(sd, REG_CMATRIX_SIGN, &signbits);
1166 	signbits &= 0xc0;
1167 
1168 	for (i = 0; i < CMATRIX_LEN; i++) {
1169 		unsigned char raw;
1170 
1171 		if (matrix[i] < 0) {
1172 			signbits |= (1 << i);
1173 			if (matrix[i] < -255)
1174 				raw = 0xff;
1175 			else
1176 				raw = (-1 * matrix[i]) & 0xff;
1177 		}
1178 		else {
1179 			if (matrix[i] > 255)
1180 				raw = 0xff;
1181 			else
1182 				raw = matrix[i] & 0xff;
1183 		}
1184 		ret += ov7670_write(sd, REG_CMATRIX_BASE + i, raw);
1185 	}
1186 	ret += ov7670_write(sd, REG_CMATRIX_SIGN, signbits);
1187 	return ret;
1188 }
1189 
1190 
1191 /*
1192  * Hue also requires messing with the color matrix.  It also requires
1193  * trig functions, which tend not to be well supported in the kernel.
1194  * So here is a simple table of sine values, 0-90 degrees, in steps
1195  * of five degrees.  Values are multiplied by 1000.
1196  *
1197  * The following naive approximate trig functions require an argument
1198  * carefully limited to -180 <= theta <= 180.
1199  */
1200 #define SIN_STEP 5
1201 static const int ov7670_sin_table[] = {
1202 	   0,	 87,   173,   258,   342,   422,
1203 	 499,	573,   642,   707,   766,   819,
1204 	 866,	906,   939,   965,   984,   996,
1205 	1000
1206 };
1207 
1208 static int ov7670_sine(int theta)
1209 {
1210 	int chs = 1;
1211 	int sine;
1212 
1213 	if (theta < 0) {
1214 		theta = -theta;
1215 		chs = -1;
1216 	}
1217 	if (theta <= 90)
1218 		sine = ov7670_sin_table[theta/SIN_STEP];
1219 	else {
1220 		theta -= 90;
1221 		sine = 1000 - ov7670_sin_table[theta/SIN_STEP];
1222 	}
1223 	return sine*chs;
1224 }
1225 
1226 static int ov7670_cosine(int theta)
1227 {
1228 	theta = 90 - theta;
1229 	if (theta > 180)
1230 		theta -= 360;
1231 	else if (theta < -180)
1232 		theta += 360;
1233 	return ov7670_sine(theta);
1234 }
1235 
1236 
1237 
1238 
1239 static void ov7670_calc_cmatrix(struct ov7670_info *info,
1240 		int matrix[CMATRIX_LEN], int sat, int hue)
1241 {
1242 	int i;
1243 	/*
1244 	 * Apply the current saturation setting first.
1245 	 */
1246 	for (i = 0; i < CMATRIX_LEN; i++)
1247 		matrix[i] = (info->fmt->cmatrix[i] * sat) >> 7;
1248 	/*
1249 	 * Then, if need be, rotate the hue value.
1250 	 */
1251 	if (hue != 0) {
1252 		int sinth, costh, tmpmatrix[CMATRIX_LEN];
1253 
1254 		memcpy(tmpmatrix, matrix, CMATRIX_LEN*sizeof(int));
1255 		sinth = ov7670_sine(hue);
1256 		costh = ov7670_cosine(hue);
1257 
1258 		matrix[0] = (matrix[3]*sinth + matrix[0]*costh)/1000;
1259 		matrix[1] = (matrix[4]*sinth + matrix[1]*costh)/1000;
1260 		matrix[2] = (matrix[5]*sinth + matrix[2]*costh)/1000;
1261 		matrix[3] = (matrix[3]*costh - matrix[0]*sinth)/1000;
1262 		matrix[4] = (matrix[4]*costh - matrix[1]*sinth)/1000;
1263 		matrix[5] = (matrix[5]*costh - matrix[2]*sinth)/1000;
1264 	}
1265 }
1266 
1267 
1268 
1269 static int ov7670_s_sat_hue(struct v4l2_subdev *sd, int sat, int hue)
1270 {
1271 	struct ov7670_info *info = to_state(sd);
1272 	int matrix[CMATRIX_LEN];
1273 	int ret;
1274 
1275 	ov7670_calc_cmatrix(info, matrix, sat, hue);
1276 	ret = ov7670_store_cmatrix(sd, matrix);
1277 	return ret;
1278 }
1279 
1280 
1281 /*
1282  * Some weird registers seem to store values in a sign/magnitude format!
1283  */
1284 
1285 static unsigned char ov7670_abs_to_sm(unsigned char v)
1286 {
1287 	if (v > 127)
1288 		return v & 0x7f;
1289 	return (128 - v) | 0x80;
1290 }
1291 
1292 static int ov7670_s_brightness(struct v4l2_subdev *sd, int value)
1293 {
1294 	unsigned char com8 = 0, v;
1295 	int ret;
1296 
1297 	ov7670_read(sd, REG_COM8, &com8);
1298 	com8 &= ~COM8_AEC;
1299 	ov7670_write(sd, REG_COM8, com8);
1300 	v = ov7670_abs_to_sm(value);
1301 	ret = ov7670_write(sd, REG_BRIGHT, v);
1302 	return ret;
1303 }
1304 
1305 static int ov7670_s_contrast(struct v4l2_subdev *sd, int value)
1306 {
1307 	return ov7670_write(sd, REG_CONTRAS, (unsigned char) value);
1308 }
1309 
1310 static int ov7670_s_hflip(struct v4l2_subdev *sd, int value)
1311 {
1312 	unsigned char v = 0;
1313 	int ret;
1314 
1315 	ret = ov7670_read(sd, REG_MVFP, &v);
1316 	if (value)
1317 		v |= MVFP_MIRROR;
1318 	else
1319 		v &= ~MVFP_MIRROR;
1320 	msleep(10);  /* FIXME */
1321 	ret += ov7670_write(sd, REG_MVFP, v);
1322 	return ret;
1323 }
1324 
1325 static int ov7670_s_vflip(struct v4l2_subdev *sd, int value)
1326 {
1327 	unsigned char v = 0;
1328 	int ret;
1329 
1330 	ret = ov7670_read(sd, REG_MVFP, &v);
1331 	if (value)
1332 		v |= MVFP_FLIP;
1333 	else
1334 		v &= ~MVFP_FLIP;
1335 	msleep(10);  /* FIXME */
1336 	ret += ov7670_write(sd, REG_MVFP, v);
1337 	return ret;
1338 }
1339 
1340 /*
1341  * GAIN is split between REG_GAIN and REG_VREF[7:6].  If one believes
1342  * the data sheet, the VREF parts should be the most significant, but
1343  * experience shows otherwise.  There seems to be little value in
1344  * messing with the VREF bits, so we leave them alone.
1345  */
1346 static int ov7670_g_gain(struct v4l2_subdev *sd, __s32 *value)
1347 {
1348 	int ret;
1349 	unsigned char gain;
1350 
1351 	ret = ov7670_read(sd, REG_GAIN, &gain);
1352 	*value = gain;
1353 	return ret;
1354 }
1355 
1356 static int ov7670_s_gain(struct v4l2_subdev *sd, int value)
1357 {
1358 	int ret;
1359 	unsigned char com8;
1360 
1361 	ret = ov7670_write(sd, REG_GAIN, value & 0xff);
1362 	/* Have to turn off AGC as well */
1363 	if (ret == 0) {
1364 		ret = ov7670_read(sd, REG_COM8, &com8);
1365 		ret = ov7670_write(sd, REG_COM8, com8 & ~COM8_AGC);
1366 	}
1367 	return ret;
1368 }
1369 
1370 /*
1371  * Tweak autogain.
1372  */
1373 static int ov7670_s_autogain(struct v4l2_subdev *sd, int value)
1374 {
1375 	int ret;
1376 	unsigned char com8;
1377 
1378 	ret = ov7670_read(sd, REG_COM8, &com8);
1379 	if (ret == 0) {
1380 		if (value)
1381 			com8 |= COM8_AGC;
1382 		else
1383 			com8 &= ~COM8_AGC;
1384 		ret = ov7670_write(sd, REG_COM8, com8);
1385 	}
1386 	return ret;
1387 }
1388 
1389 static int ov7670_s_exp(struct v4l2_subdev *sd, int value)
1390 {
1391 	int ret;
1392 	unsigned char com1, com8, aech, aechh;
1393 
1394 	ret = ov7670_read(sd, REG_COM1, &com1) +
1395 		ov7670_read(sd, REG_COM8, &com8) +
1396 		ov7670_read(sd, REG_AECHH, &aechh);
1397 	if (ret)
1398 		return ret;
1399 
1400 	com1 = (com1 & 0xfc) | (value & 0x03);
1401 	aech = (value >> 2) & 0xff;
1402 	aechh = (aechh & 0xc0) | ((value >> 10) & 0x3f);
1403 	ret = ov7670_write(sd, REG_COM1, com1) +
1404 		ov7670_write(sd, REG_AECH, aech) +
1405 		ov7670_write(sd, REG_AECHH, aechh);
1406 	/* Have to turn off AEC as well */
1407 	if (ret == 0)
1408 		ret = ov7670_write(sd, REG_COM8, com8 & ~COM8_AEC);
1409 	return ret;
1410 }
1411 
1412 /*
1413  * Tweak autoexposure.
1414  */
1415 static int ov7670_s_autoexp(struct v4l2_subdev *sd,
1416 		enum v4l2_exposure_auto_type value)
1417 {
1418 	int ret;
1419 	unsigned char com8;
1420 
1421 	ret = ov7670_read(sd, REG_COM8, &com8);
1422 	if (ret == 0) {
1423 		if (value == V4L2_EXPOSURE_AUTO)
1424 			com8 |= COM8_AEC;
1425 		else
1426 			com8 &= ~COM8_AEC;
1427 		ret = ov7670_write(sd, REG_COM8, com8);
1428 	}
1429 	return ret;
1430 }
1431 
1432 
1433 static int ov7670_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
1434 {
1435 	struct v4l2_subdev *sd = to_sd(ctrl);
1436 	struct ov7670_info *info = to_state(sd);
1437 
1438 	switch (ctrl->id) {
1439 	case V4L2_CID_AUTOGAIN:
1440 		return ov7670_g_gain(sd, &info->gain->val);
1441 	}
1442 	return -EINVAL;
1443 }
1444 
1445 static int ov7670_s_ctrl(struct v4l2_ctrl *ctrl)
1446 {
1447 	struct v4l2_subdev *sd = to_sd(ctrl);
1448 	struct ov7670_info *info = to_state(sd);
1449 
1450 	switch (ctrl->id) {
1451 	case V4L2_CID_BRIGHTNESS:
1452 		return ov7670_s_brightness(sd, ctrl->val);
1453 	case V4L2_CID_CONTRAST:
1454 		return ov7670_s_contrast(sd, ctrl->val);
1455 	case V4L2_CID_SATURATION:
1456 		return ov7670_s_sat_hue(sd,
1457 				info->saturation->val, info->hue->val);
1458 	case V4L2_CID_VFLIP:
1459 		return ov7670_s_vflip(sd, ctrl->val);
1460 	case V4L2_CID_HFLIP:
1461 		return ov7670_s_hflip(sd, ctrl->val);
1462 	case V4L2_CID_AUTOGAIN:
1463 		/* Only set manual gain if auto gain is not explicitly
1464 		   turned on. */
1465 		if (!ctrl->val) {
1466 			/* ov7670_s_gain turns off auto gain */
1467 			return ov7670_s_gain(sd, info->gain->val);
1468 		}
1469 		return ov7670_s_autogain(sd, ctrl->val);
1470 	case V4L2_CID_EXPOSURE_AUTO:
1471 		/* Only set manual exposure if auto exposure is not explicitly
1472 		   turned on. */
1473 		if (ctrl->val == V4L2_EXPOSURE_MANUAL) {
1474 			/* ov7670_s_exp turns off auto exposure */
1475 			return ov7670_s_exp(sd, info->exposure->val);
1476 		}
1477 		return ov7670_s_autoexp(sd, ctrl->val);
1478 	}
1479 	return -EINVAL;
1480 }
1481 
1482 static const struct v4l2_ctrl_ops ov7670_ctrl_ops = {
1483 	.s_ctrl = ov7670_s_ctrl,
1484 	.g_volatile_ctrl = ov7670_g_volatile_ctrl,
1485 };
1486 
1487 #ifdef CONFIG_VIDEO_ADV_DEBUG
1488 static int ov7670_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
1489 {
1490 	unsigned char val = 0;
1491 	int ret;
1492 
1493 	ret = ov7670_read(sd, reg->reg & 0xff, &val);
1494 	reg->val = val;
1495 	reg->size = 1;
1496 	return ret;
1497 }
1498 
1499 static int ov7670_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
1500 {
1501 	ov7670_write(sd, reg->reg & 0xff, reg->val & 0xff);
1502 	return 0;
1503 }
1504 #endif
1505 
1506 /* ----------------------------------------------------------------------- */
1507 
1508 static const struct v4l2_subdev_core_ops ov7670_core_ops = {
1509 	.reset = ov7670_reset,
1510 	.init = ov7670_init,
1511 #ifdef CONFIG_VIDEO_ADV_DEBUG
1512 	.g_register = ov7670_g_register,
1513 	.s_register = ov7670_s_register,
1514 #endif
1515 };
1516 
1517 static const struct v4l2_subdev_video_ops ov7670_video_ops = {
1518 	.s_parm = ov7670_s_parm,
1519 	.g_parm = ov7670_g_parm,
1520 };
1521 
1522 static const struct v4l2_subdev_pad_ops ov7670_pad_ops = {
1523 	.enum_frame_interval = ov7670_enum_frame_interval,
1524 	.enum_frame_size = ov7670_enum_frame_size,
1525 	.enum_mbus_code = ov7670_enum_mbus_code,
1526 	.set_fmt = ov7670_set_fmt,
1527 };
1528 
1529 static const struct v4l2_subdev_ops ov7670_ops = {
1530 	.core = &ov7670_core_ops,
1531 	.video = &ov7670_video_ops,
1532 	.pad = &ov7670_pad_ops,
1533 };
1534 
1535 /* ----------------------------------------------------------------------- */
1536 
1537 static const struct ov7670_devtype ov7670_devdata[] = {
1538 	[MODEL_OV7670] = {
1539 		.win_sizes = ov7670_win_sizes,
1540 		.n_win_sizes = ARRAY_SIZE(ov7670_win_sizes),
1541 		.set_framerate = ov7670_set_framerate_legacy,
1542 		.get_framerate = ov7670_get_framerate_legacy,
1543 	},
1544 	[MODEL_OV7675] = {
1545 		.win_sizes = ov7675_win_sizes,
1546 		.n_win_sizes = ARRAY_SIZE(ov7675_win_sizes),
1547 		.set_framerate = ov7675_set_framerate,
1548 		.get_framerate = ov7675_get_framerate,
1549 	},
1550 };
1551 
1552 static int ov7670_probe(struct i2c_client *client,
1553 			const struct i2c_device_id *id)
1554 {
1555 	struct v4l2_fract tpf;
1556 	struct v4l2_subdev *sd;
1557 	struct ov7670_info *info;
1558 	int ret;
1559 
1560 	info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
1561 	if (info == NULL)
1562 		return -ENOMEM;
1563 	sd = &info->sd;
1564 	v4l2_i2c_subdev_init(sd, client, &ov7670_ops);
1565 
1566 	info->clock_speed = 30; /* default: a guess */
1567 	if (client->dev.platform_data) {
1568 		struct ov7670_config *config = client->dev.platform_data;
1569 
1570 		/*
1571 		 * Must apply configuration before initializing device, because it
1572 		 * selects I/O method.
1573 		 */
1574 		info->min_width = config->min_width;
1575 		info->min_height = config->min_height;
1576 		info->use_smbus = config->use_smbus;
1577 
1578 		if (config->clock_speed)
1579 			info->clock_speed = config->clock_speed;
1580 
1581 		/*
1582 		 * It should be allowed for ov7670 too when it is migrated to
1583 		 * the new frame rate formula.
1584 		 */
1585 		if (config->pll_bypass && id->driver_data != MODEL_OV7670)
1586 			info->pll_bypass = true;
1587 
1588 		if (config->pclk_hb_disable)
1589 			info->pclk_hb_disable = true;
1590 	}
1591 
1592 	/* Make sure it's an ov7670 */
1593 	ret = ov7670_detect(sd);
1594 	if (ret) {
1595 		v4l_dbg(1, debug, client,
1596 			"chip found @ 0x%x (%s) is not an ov7670 chip.\n",
1597 			client->addr << 1, client->adapter->name);
1598 		return ret;
1599 	}
1600 	v4l_info(client, "chip found @ 0x%02x (%s)\n",
1601 			client->addr << 1, client->adapter->name);
1602 
1603 	info->devtype = &ov7670_devdata[id->driver_data];
1604 	info->fmt = &ov7670_formats[0];
1605 	info->clkrc = 0;
1606 
1607 	/* Set default frame rate to 30 fps */
1608 	tpf.numerator = 1;
1609 	tpf.denominator = 30;
1610 	info->devtype->set_framerate(sd, &tpf);
1611 
1612 	if (info->pclk_hb_disable)
1613 		ov7670_write(sd, REG_COM10, COM10_PCLK_HB);
1614 
1615 	v4l2_ctrl_handler_init(&info->hdl, 10);
1616 	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1617 			V4L2_CID_BRIGHTNESS, 0, 255, 1, 128);
1618 	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1619 			V4L2_CID_CONTRAST, 0, 127, 1, 64);
1620 	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1621 			V4L2_CID_VFLIP, 0, 1, 1, 0);
1622 	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1623 			V4L2_CID_HFLIP, 0, 1, 1, 0);
1624 	info->saturation = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1625 			V4L2_CID_SATURATION, 0, 256, 1, 128);
1626 	info->hue = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1627 			V4L2_CID_HUE, -180, 180, 5, 0);
1628 	info->gain = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1629 			V4L2_CID_GAIN, 0, 255, 1, 128);
1630 	info->auto_gain = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1631 			V4L2_CID_AUTOGAIN, 0, 1, 1, 1);
1632 	info->exposure = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1633 			V4L2_CID_EXPOSURE, 0, 65535, 1, 500);
1634 	info->auto_exposure = v4l2_ctrl_new_std_menu(&info->hdl, &ov7670_ctrl_ops,
1635 			V4L2_CID_EXPOSURE_AUTO, V4L2_EXPOSURE_MANUAL, 0,
1636 			V4L2_EXPOSURE_AUTO);
1637 	sd->ctrl_handler = &info->hdl;
1638 	if (info->hdl.error) {
1639 		int err = info->hdl.error;
1640 
1641 		v4l2_ctrl_handler_free(&info->hdl);
1642 		return err;
1643 	}
1644 	/*
1645 	 * We have checked empirically that hw allows to read back the gain
1646 	 * value chosen by auto gain but that's not the case for auto exposure.
1647 	 */
1648 	v4l2_ctrl_auto_cluster(2, &info->auto_gain, 0, true);
1649 	v4l2_ctrl_auto_cluster(2, &info->auto_exposure,
1650 			       V4L2_EXPOSURE_MANUAL, false);
1651 	v4l2_ctrl_cluster(2, &info->saturation);
1652 	v4l2_ctrl_handler_setup(&info->hdl);
1653 
1654 	return 0;
1655 }
1656 
1657 
1658 static int ov7670_remove(struct i2c_client *client)
1659 {
1660 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
1661 	struct ov7670_info *info = to_state(sd);
1662 
1663 	v4l2_device_unregister_subdev(sd);
1664 	v4l2_ctrl_handler_free(&info->hdl);
1665 	return 0;
1666 }
1667 
1668 static const struct i2c_device_id ov7670_id[] = {
1669 	{ "ov7670", MODEL_OV7670 },
1670 	{ "ov7675", MODEL_OV7675 },
1671 	{ }
1672 };
1673 MODULE_DEVICE_TABLE(i2c, ov7670_id);
1674 
1675 static struct i2c_driver ov7670_driver = {
1676 	.driver = {
1677 		.name	= "ov7670",
1678 	},
1679 	.probe		= ov7670_probe,
1680 	.remove		= ov7670_remove,
1681 	.id_table	= ov7670_id,
1682 };
1683 
1684 module_i2c_driver(ov7670_driver);
1685