xref: /openbmc/linux/drivers/media/i2c/ov7670.c (revision 206a81c1)
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/ov7670.h>
23 
24 MODULE_AUTHOR("Jonathan Corbet <corbet@lwn.net>");
25 MODULE_DESCRIPTION("A low-level driver for OmniVision ov7670 sensors");
26 MODULE_LICENSE("GPL");
27 
28 static bool debug;
29 module_param(debug, bool, 0644);
30 MODULE_PARM_DESC(debug, "Debug level (0-1)");
31 
32 /*
33  * Basic window sizes.  These probably belong somewhere more globally
34  * useful.
35  */
36 #define VGA_WIDTH	640
37 #define VGA_HEIGHT	480
38 #define QVGA_WIDTH	320
39 #define QVGA_HEIGHT	240
40 #define CIF_WIDTH	352
41 #define CIF_HEIGHT	288
42 #define QCIF_WIDTH	176
43 #define	QCIF_HEIGHT	144
44 
45 /*
46  * The 7670 sits on i2c with ID 0x42
47  */
48 #define OV7670_I2C_ADDR 0x42
49 
50 #define PLL_FACTOR	4
51 
52 /* Registers */
53 #define REG_GAIN	0x00	/* Gain lower 8 bits (rest in vref) */
54 #define REG_BLUE	0x01	/* blue gain */
55 #define REG_RED		0x02	/* red gain */
56 #define REG_VREF	0x03	/* Pieces of GAIN, VSTART, VSTOP */
57 #define REG_COM1	0x04	/* Control 1 */
58 #define  COM1_CCIR656	  0x40  /* CCIR656 enable */
59 #define REG_BAVE	0x05	/* U/B Average level */
60 #define REG_GbAVE	0x06	/* Y/Gb Average level */
61 #define REG_AECHH	0x07	/* AEC MS 5 bits */
62 #define REG_RAVE	0x08	/* V/R Average level */
63 #define REG_COM2	0x09	/* Control 2 */
64 #define  COM2_SSLEEP	  0x10	/* Soft sleep mode */
65 #define REG_PID		0x0a	/* Product ID MSB */
66 #define REG_VER		0x0b	/* Product ID LSB */
67 #define REG_COM3	0x0c	/* Control 3 */
68 #define  COM3_SWAP	  0x40	  /* Byte swap */
69 #define  COM3_SCALEEN	  0x08	  /* Enable scaling */
70 #define  COM3_DCWEN	  0x04	  /* Enable downsamp/crop/window */
71 #define REG_COM4	0x0d	/* Control 4 */
72 #define REG_COM5	0x0e	/* All "reserved" */
73 #define REG_COM6	0x0f	/* Control 6 */
74 #define REG_AECH	0x10	/* More bits of AEC value */
75 #define REG_CLKRC	0x11	/* Clocl control */
76 #define   CLK_EXT	  0x40	  /* Use external clock directly */
77 #define   CLK_SCALE	  0x3f	  /* Mask for internal clock scale */
78 #define REG_COM7	0x12	/* Control 7 */
79 #define   COM7_RESET	  0x80	  /* Register reset */
80 #define   COM7_FMT_MASK	  0x38
81 #define   COM7_FMT_VGA	  0x00
82 #define	  COM7_FMT_CIF	  0x20	  /* CIF format */
83 #define   COM7_FMT_QVGA	  0x10	  /* QVGA format */
84 #define   COM7_FMT_QCIF	  0x08	  /* QCIF format */
85 #define	  COM7_RGB	  0x04	  /* bits 0 and 2 - RGB format */
86 #define	  COM7_YUV	  0x00	  /* YUV */
87 #define	  COM7_BAYER	  0x01	  /* Bayer format */
88 #define	  COM7_PBAYER	  0x05	  /* "Processed bayer" */
89 #define REG_COM8	0x13	/* Control 8 */
90 #define   COM8_FASTAEC	  0x80	  /* Enable fast AGC/AEC */
91 #define   COM8_AECSTEP	  0x40	  /* Unlimited AEC step size */
92 #define   COM8_BFILT	  0x20	  /* Band filter enable */
93 #define   COM8_AGC	  0x04	  /* Auto gain enable */
94 #define   COM8_AWB	  0x02	  /* White balance enable */
95 #define   COM8_AEC	  0x01	  /* Auto exposure enable */
96 #define REG_COM9	0x14	/* Control 9  - gain ceiling */
97 #define REG_COM10	0x15	/* Control 10 */
98 #define   COM10_HSYNC	  0x40	  /* HSYNC instead of HREF */
99 #define   COM10_PCLK_HB	  0x20	  /* Suppress PCLK on horiz blank */
100 #define   COM10_HREF_REV  0x08	  /* Reverse HREF */
101 #define   COM10_VS_LEAD	  0x04	  /* VSYNC on clock leading edge */
102 #define   COM10_VS_NEG	  0x02	  /* VSYNC negative */
103 #define   COM10_HS_NEG	  0x01	  /* HSYNC negative */
104 #define REG_HSTART	0x17	/* Horiz start high bits */
105 #define REG_HSTOP	0x18	/* Horiz stop high bits */
106 #define REG_VSTART	0x19	/* Vert start high bits */
107 #define REG_VSTOP	0x1a	/* Vert stop high bits */
108 #define REG_PSHFT	0x1b	/* Pixel delay after HREF */
109 #define REG_MIDH	0x1c	/* Manuf. ID high */
110 #define REG_MIDL	0x1d	/* Manuf. ID low */
111 #define REG_MVFP	0x1e	/* Mirror / vflip */
112 #define   MVFP_MIRROR	  0x20	  /* Mirror image */
113 #define   MVFP_FLIP	  0x10	  /* Vertical flip */
114 
115 #define REG_AEW		0x24	/* AGC upper limit */
116 #define REG_AEB		0x25	/* AGC lower limit */
117 #define REG_VPT		0x26	/* AGC/AEC fast mode op region */
118 #define REG_HSYST	0x30	/* HSYNC rising edge delay */
119 #define REG_HSYEN	0x31	/* HSYNC falling edge delay */
120 #define REG_HREF	0x32	/* HREF pieces */
121 #define REG_TSLB	0x3a	/* lots of stuff */
122 #define   TSLB_YLAST	  0x04	  /* UYVY or VYUY - see com13 */
123 #define REG_COM11	0x3b	/* Control 11 */
124 #define   COM11_NIGHT	  0x80	  /* NIght mode enable */
125 #define   COM11_NMFR	  0x60	  /* Two bit NM frame rate */
126 #define   COM11_HZAUTO	  0x10	  /* Auto detect 50/60 Hz */
127 #define	  COM11_50HZ	  0x08	  /* Manual 50Hz select */
128 #define   COM11_EXP	  0x02
129 #define REG_COM12	0x3c	/* Control 12 */
130 #define   COM12_HREF	  0x80	  /* HREF always */
131 #define REG_COM13	0x3d	/* Control 13 */
132 #define   COM13_GAMMA	  0x80	  /* Gamma enable */
133 #define	  COM13_UVSAT	  0x40	  /* UV saturation auto adjustment */
134 #define   COM13_UVSWAP	  0x01	  /* V before U - w/TSLB */
135 #define REG_COM14	0x3e	/* Control 14 */
136 #define   COM14_DCWEN	  0x10	  /* DCW/PCLK-scale enable */
137 #define REG_EDGE	0x3f	/* Edge enhancement factor */
138 #define REG_COM15	0x40	/* Control 15 */
139 #define   COM15_R10F0	  0x00	  /* Data range 10 to F0 */
140 #define	  COM15_R01FE	  0x80	  /*            01 to FE */
141 #define   COM15_R00FF	  0xc0	  /*            00 to FF */
142 #define   COM15_RGB565	  0x10	  /* RGB565 output */
143 #define   COM15_RGB555	  0x30	  /* RGB555 output */
144 #define REG_COM16	0x41	/* Control 16 */
145 #define   COM16_AWBGAIN   0x08	  /* AWB gain enable */
146 #define REG_COM17	0x42	/* Control 17 */
147 #define   COM17_AECWIN	  0xc0	  /* AEC window - must match COM4 */
148 #define   COM17_CBAR	  0x08	  /* DSP Color bar */
149 
150 /*
151  * This matrix defines how the colors are generated, must be
152  * tweaked to adjust hue and saturation.
153  *
154  * Order: v-red, v-green, v-blue, u-red, u-green, u-blue
155  *
156  * They are nine-bit signed quantities, with the sign bit
157  * stored in 0x58.  Sign for v-red is bit 0, and up from there.
158  */
159 #define	REG_CMATRIX_BASE 0x4f
160 #define   CMATRIX_LEN 6
161 #define REG_CMATRIX_SIGN 0x58
162 
163 
164 #define REG_BRIGHT	0x55	/* Brightness */
165 #define REG_CONTRAS	0x56	/* Contrast control */
166 
167 #define REG_GFIX	0x69	/* Fix gain control */
168 
169 #define REG_DBLV	0x6b	/* PLL control an debugging */
170 #define   DBLV_BYPASS	  0x00	  /* Bypass PLL */
171 #define   DBLV_X4	  0x01	  /* clock x4 */
172 #define   DBLV_X6	  0x10	  /* clock x6 */
173 #define   DBLV_X8	  0x11	  /* clock x8 */
174 
175 #define REG_REG76	0x76	/* OV's name */
176 #define   R76_BLKPCOR	  0x80	  /* Black pixel correction enable */
177 #define   R76_WHTPCOR	  0x40	  /* White pixel correction enable */
178 
179 #define REG_RGB444	0x8c	/* RGB 444 control */
180 #define   R444_ENABLE	  0x02	  /* Turn on RGB444, overrides 5x5 */
181 #define   R444_RGBX	  0x01	  /* Empty nibble at end */
182 
183 #define REG_HAECC1	0x9f	/* Hist AEC/AGC control 1 */
184 #define REG_HAECC2	0xa0	/* Hist AEC/AGC control 2 */
185 
186 #define REG_BD50MAX	0xa5	/* 50hz banding step limit */
187 #define REG_HAECC3	0xa6	/* Hist AEC/AGC control 3 */
188 #define REG_HAECC4	0xa7	/* Hist AEC/AGC control 4 */
189 #define REG_HAECC5	0xa8	/* Hist AEC/AGC control 5 */
190 #define REG_HAECC6	0xa9	/* Hist AEC/AGC control 6 */
191 #define REG_HAECC7	0xaa	/* Hist AEC/AGC control 7 */
192 #define REG_BD60MAX	0xab	/* 60hz banding step limit */
193 
194 enum ov7670_model {
195 	MODEL_OV7670 = 0,
196 	MODEL_OV7675,
197 };
198 
199 struct ov7670_win_size {
200 	int	width;
201 	int	height;
202 	unsigned char com7_bit;
203 	int	hstart;		/* Start/stop values for the camera.  Note */
204 	int	hstop;		/* that they do not always make complete */
205 	int	vstart;		/* sense to humans, but evidently the sensor */
206 	int	vstop;		/* will do the right thing... */
207 	struct regval_list *regs; /* Regs to tweak */
208 };
209 
210 struct ov7670_devtype {
211 	/* formats supported for each model */
212 	struct ov7670_win_size *win_sizes;
213 	unsigned int n_win_sizes;
214 	/* callbacks for frame rate control */
215 	int (*set_framerate)(struct v4l2_subdev *, struct v4l2_fract *);
216 	void (*get_framerate)(struct v4l2_subdev *, struct v4l2_fract *);
217 };
218 
219 /*
220  * Information we maintain about a known sensor.
221  */
222 struct ov7670_format_struct;  /* coming later */
223 struct ov7670_info {
224 	struct v4l2_subdev sd;
225 	struct v4l2_ctrl_handler hdl;
226 	struct {
227 		/* gain cluster */
228 		struct v4l2_ctrl *auto_gain;
229 		struct v4l2_ctrl *gain;
230 	};
231 	struct {
232 		/* exposure cluster */
233 		struct v4l2_ctrl *auto_exposure;
234 		struct v4l2_ctrl *exposure;
235 	};
236 	struct {
237 		/* saturation/hue cluster */
238 		struct v4l2_ctrl *saturation;
239 		struct v4l2_ctrl *hue;
240 	};
241 	struct ov7670_format_struct *fmt;  /* Current format */
242 	int min_width;			/* Filter out smaller sizes */
243 	int min_height;			/* Filter out smaller sizes */
244 	int clock_speed;		/* External clock speed (MHz) */
245 	u8 clkrc;			/* Clock divider value */
246 	bool use_smbus;			/* Use smbus I/O instead of I2C */
247 	bool pll_bypass;
248 	bool pclk_hb_disable;
249 	const struct ov7670_devtype *devtype; /* Device specifics */
250 };
251 
252 static inline struct ov7670_info *to_state(struct v4l2_subdev *sd)
253 {
254 	return container_of(sd, struct ov7670_info, sd);
255 }
256 
257 static inline struct v4l2_subdev *to_sd(struct v4l2_ctrl *ctrl)
258 {
259 	return &container_of(ctrl->handler, struct ov7670_info, hdl)->sd;
260 }
261 
262 
263 
264 /*
265  * The default register settings, as obtained from OmniVision.  There
266  * is really no making sense of most of these - lots of "reserved" values
267  * and such.
268  *
269  * These settings give VGA YUYV.
270  */
271 
272 struct regval_list {
273 	unsigned char reg_num;
274 	unsigned char value;
275 };
276 
277 static struct regval_list ov7670_default_regs[] = {
278 	{ REG_COM7, COM7_RESET },
279 /*
280  * Clock scale: 3 = 15fps
281  *              2 = 20fps
282  *              1 = 30fps
283  */
284 	{ REG_CLKRC, 0x1 },	/* OV: clock scale (30 fps) */
285 	{ REG_TSLB,  0x04 },	/* OV */
286 	{ REG_COM7, 0 },	/* VGA */
287 	/*
288 	 * Set the hardware window.  These values from OV don't entirely
289 	 * make sense - hstop is less than hstart.  But they work...
290 	 */
291 	{ REG_HSTART, 0x13 },	{ REG_HSTOP, 0x01 },
292 	{ REG_HREF, 0xb6 },	{ REG_VSTART, 0x02 },
293 	{ REG_VSTOP, 0x7a },	{ REG_VREF, 0x0a },
294 
295 	{ REG_COM3, 0 },	{ REG_COM14, 0 },
296 	/* Mystery scaling numbers */
297 	{ 0x70, 0x3a },		{ 0x71, 0x35 },
298 	{ 0x72, 0x11 },		{ 0x73, 0xf0 },
299 	{ 0xa2, 0x02 },		{ REG_COM10, 0x0 },
300 
301 	/* Gamma curve values */
302 	{ 0x7a, 0x20 },		{ 0x7b, 0x10 },
303 	{ 0x7c, 0x1e },		{ 0x7d, 0x35 },
304 	{ 0x7e, 0x5a },		{ 0x7f, 0x69 },
305 	{ 0x80, 0x76 },		{ 0x81, 0x80 },
306 	{ 0x82, 0x88 },		{ 0x83, 0x8f },
307 	{ 0x84, 0x96 },		{ 0x85, 0xa3 },
308 	{ 0x86, 0xaf },		{ 0x87, 0xc4 },
309 	{ 0x88, 0xd7 },		{ 0x89, 0xe8 },
310 
311 	/* AGC and AEC parameters.  Note we start by disabling those features,
312 	   then turn them only after tweaking the values. */
313 	{ REG_COM8, COM8_FASTAEC | COM8_AECSTEP | COM8_BFILT },
314 	{ REG_GAIN, 0 },	{ REG_AECH, 0 },
315 	{ REG_COM4, 0x40 }, /* magic reserved bit */
316 	{ REG_COM9, 0x18 }, /* 4x gain + magic rsvd bit */
317 	{ REG_BD50MAX, 0x05 },	{ REG_BD60MAX, 0x07 },
318 	{ REG_AEW, 0x95 },	{ REG_AEB, 0x33 },
319 	{ REG_VPT, 0xe3 },	{ REG_HAECC1, 0x78 },
320 	{ REG_HAECC2, 0x68 },	{ 0xa1, 0x03 }, /* magic */
321 	{ REG_HAECC3, 0xd8 },	{ REG_HAECC4, 0xd8 },
322 	{ REG_HAECC5, 0xf0 },	{ REG_HAECC6, 0x90 },
323 	{ REG_HAECC7, 0x94 },
324 	{ REG_COM8, COM8_FASTAEC|COM8_AECSTEP|COM8_BFILT|COM8_AGC|COM8_AEC },
325 
326 	/* Almost all of these are magic "reserved" values.  */
327 	{ REG_COM5, 0x61 },	{ REG_COM6, 0x4b },
328 	{ 0x16, 0x02 },		{ REG_MVFP, 0x07 },
329 	{ 0x21, 0x02 },		{ 0x22, 0x91 },
330 	{ 0x29, 0x07 },		{ 0x33, 0x0b },
331 	{ 0x35, 0x0b },		{ 0x37, 0x1d },
332 	{ 0x38, 0x71 },		{ 0x39, 0x2a },
333 	{ REG_COM12, 0x78 },	{ 0x4d, 0x40 },
334 	{ 0x4e, 0x20 },		{ REG_GFIX, 0 },
335 	{ 0x6b, 0x4a },		{ 0x74, 0x10 },
336 	{ 0x8d, 0x4f },		{ 0x8e, 0 },
337 	{ 0x8f, 0 },		{ 0x90, 0 },
338 	{ 0x91, 0 },		{ 0x96, 0 },
339 	{ 0x9a, 0 },		{ 0xb0, 0x84 },
340 	{ 0xb1, 0x0c },		{ 0xb2, 0x0e },
341 	{ 0xb3, 0x82 },		{ 0xb8, 0x0a },
342 
343 	/* More reserved magic, some of which tweaks white balance */
344 	{ 0x43, 0x0a },		{ 0x44, 0xf0 },
345 	{ 0x45, 0x34 },		{ 0x46, 0x58 },
346 	{ 0x47, 0x28 },		{ 0x48, 0x3a },
347 	{ 0x59, 0x88 },		{ 0x5a, 0x88 },
348 	{ 0x5b, 0x44 },		{ 0x5c, 0x67 },
349 	{ 0x5d, 0x49 },		{ 0x5e, 0x0e },
350 	{ 0x6c, 0x0a },		{ 0x6d, 0x55 },
351 	{ 0x6e, 0x11 },		{ 0x6f, 0x9f }, /* "9e for advance AWB" */
352 	{ 0x6a, 0x40 },		{ REG_BLUE, 0x40 },
353 	{ REG_RED, 0x60 },
354 	{ REG_COM8, COM8_FASTAEC|COM8_AECSTEP|COM8_BFILT|COM8_AGC|COM8_AEC|COM8_AWB },
355 
356 	/* Matrix coefficients */
357 	{ 0x4f, 0x80 },		{ 0x50, 0x80 },
358 	{ 0x51, 0 },		{ 0x52, 0x22 },
359 	{ 0x53, 0x5e },		{ 0x54, 0x80 },
360 	{ 0x58, 0x9e },
361 
362 	{ REG_COM16, COM16_AWBGAIN },	{ REG_EDGE, 0 },
363 	{ 0x75, 0x05 },		{ 0x76, 0xe1 },
364 	{ 0x4c, 0 },		{ 0x77, 0x01 },
365 	{ REG_COM13, 0xc3 },	{ 0x4b, 0x09 },
366 	{ 0xc9, 0x60 },		{ REG_COM16, 0x38 },
367 	{ 0x56, 0x40 },
368 
369 	{ 0x34, 0x11 },		{ REG_COM11, COM11_EXP|COM11_HZAUTO },
370 	{ 0xa4, 0x88 },		{ 0x96, 0 },
371 	{ 0x97, 0x30 },		{ 0x98, 0x20 },
372 	{ 0x99, 0x30 },		{ 0x9a, 0x84 },
373 	{ 0x9b, 0x29 },		{ 0x9c, 0x03 },
374 	{ 0x9d, 0x4c },		{ 0x9e, 0x3f },
375 	{ 0x78, 0x04 },
376 
377 	/* Extra-weird stuff.  Some sort of multiplexor register */
378 	{ 0x79, 0x01 },		{ 0xc8, 0xf0 },
379 	{ 0x79, 0x0f },		{ 0xc8, 0x00 },
380 	{ 0x79, 0x10 },		{ 0xc8, 0x7e },
381 	{ 0x79, 0x0a },		{ 0xc8, 0x80 },
382 	{ 0x79, 0x0b },		{ 0xc8, 0x01 },
383 	{ 0x79, 0x0c },		{ 0xc8, 0x0f },
384 	{ 0x79, 0x0d },		{ 0xc8, 0x20 },
385 	{ 0x79, 0x09 },		{ 0xc8, 0x80 },
386 	{ 0x79, 0x02 },		{ 0xc8, 0xc0 },
387 	{ 0x79, 0x03 },		{ 0xc8, 0x40 },
388 	{ 0x79, 0x05 },		{ 0xc8, 0x30 },
389 	{ 0x79, 0x26 },
390 
391 	{ 0xff, 0xff },	/* END MARKER */
392 };
393 
394 
395 /*
396  * Here we'll try to encapsulate the changes for just the output
397  * video format.
398  *
399  * RGB656 and YUV422 come from OV; RGB444 is homebrewed.
400  *
401  * IMPORTANT RULE: the first entry must be for COM7, see ov7670_s_fmt for why.
402  */
403 
404 
405 static struct regval_list ov7670_fmt_yuv422[] = {
406 	{ REG_COM7, 0x0 },  /* Selects YUV mode */
407 	{ REG_RGB444, 0 },	/* No RGB444 please */
408 	{ REG_COM1, 0 },	/* CCIR601 */
409 	{ REG_COM15, COM15_R00FF },
410 	{ REG_COM9, 0x48 }, /* 32x gain ceiling; 0x8 is reserved bit */
411 	{ 0x4f, 0x80 }, 	/* "matrix coefficient 1" */
412 	{ 0x50, 0x80 }, 	/* "matrix coefficient 2" */
413 	{ 0x51, 0    },		/* vb */
414 	{ 0x52, 0x22 }, 	/* "matrix coefficient 4" */
415 	{ 0x53, 0x5e }, 	/* "matrix coefficient 5" */
416 	{ 0x54, 0x80 }, 	/* "matrix coefficient 6" */
417 	{ REG_COM13, COM13_GAMMA|COM13_UVSAT },
418 	{ 0xff, 0xff },
419 };
420 
421 static struct regval_list ov7670_fmt_rgb565[] = {
422 	{ REG_COM7, COM7_RGB },	/* Selects RGB mode */
423 	{ REG_RGB444, 0 },	/* No RGB444 please */
424 	{ REG_COM1, 0x0 },	/* CCIR601 */
425 	{ REG_COM15, COM15_RGB565 },
426 	{ REG_COM9, 0x38 }, 	/* 16x gain ceiling; 0x8 is reserved bit */
427 	{ 0x4f, 0xb3 }, 	/* "matrix coefficient 1" */
428 	{ 0x50, 0xb3 }, 	/* "matrix coefficient 2" */
429 	{ 0x51, 0    },		/* vb */
430 	{ 0x52, 0x3d }, 	/* "matrix coefficient 4" */
431 	{ 0x53, 0xa7 }, 	/* "matrix coefficient 5" */
432 	{ 0x54, 0xe4 }, 	/* "matrix coefficient 6" */
433 	{ REG_COM13, COM13_GAMMA|COM13_UVSAT },
434 	{ 0xff, 0xff },
435 };
436 
437 static struct regval_list ov7670_fmt_rgb444[] = {
438 	{ REG_COM7, COM7_RGB },	/* Selects RGB mode */
439 	{ REG_RGB444, R444_ENABLE },	/* Enable xxxxrrrr ggggbbbb */
440 	{ REG_COM1, 0x0 },	/* CCIR601 */
441 	{ REG_COM15, COM15_R01FE|COM15_RGB565 }, /* Data range needed? */
442 	{ REG_COM9, 0x38 }, 	/* 16x gain ceiling; 0x8 is reserved bit */
443 	{ 0x4f, 0xb3 }, 	/* "matrix coefficient 1" */
444 	{ 0x50, 0xb3 }, 	/* "matrix coefficient 2" */
445 	{ 0x51, 0    },		/* vb */
446 	{ 0x52, 0x3d }, 	/* "matrix coefficient 4" */
447 	{ 0x53, 0xa7 }, 	/* "matrix coefficient 5" */
448 	{ 0x54, 0xe4 }, 	/* "matrix coefficient 6" */
449 	{ REG_COM13, COM13_GAMMA|COM13_UVSAT|0x2 },  /* Magic rsvd bit */
450 	{ 0xff, 0xff },
451 };
452 
453 static struct regval_list ov7670_fmt_raw[] = {
454 	{ REG_COM7, COM7_BAYER },
455 	{ REG_COM13, 0x08 }, /* No gamma, magic rsvd bit */
456 	{ REG_COM16, 0x3d }, /* Edge enhancement, denoise */
457 	{ REG_REG76, 0xe1 }, /* Pix correction, magic rsvd */
458 	{ 0xff, 0xff },
459 };
460 
461 
462 
463 /*
464  * Low-level register I/O.
465  *
466  * Note that there are two versions of these.  On the XO 1, the
467  * i2c controller only does SMBUS, so that's what we use.  The
468  * ov7670 is not really an SMBUS device, though, so the communication
469  * is not always entirely reliable.
470  */
471 static int ov7670_read_smbus(struct v4l2_subdev *sd, unsigned char reg,
472 		unsigned char *value)
473 {
474 	struct i2c_client *client = v4l2_get_subdevdata(sd);
475 	int ret;
476 
477 	ret = i2c_smbus_read_byte_data(client, reg);
478 	if (ret >= 0) {
479 		*value = (unsigned char)ret;
480 		ret = 0;
481 	}
482 	return ret;
483 }
484 
485 
486 static int ov7670_write_smbus(struct v4l2_subdev *sd, unsigned char reg,
487 		unsigned char value)
488 {
489 	struct i2c_client *client = v4l2_get_subdevdata(sd);
490 	int ret = i2c_smbus_write_byte_data(client, reg, value);
491 
492 	if (reg == REG_COM7 && (value & COM7_RESET))
493 		msleep(5);  /* Wait for reset to run */
494 	return ret;
495 }
496 
497 /*
498  * On most platforms, we'd rather do straight i2c I/O.
499  */
500 static int ov7670_read_i2c(struct v4l2_subdev *sd, unsigned char reg,
501 		unsigned char *value)
502 {
503 	struct i2c_client *client = v4l2_get_subdevdata(sd);
504 	u8 data = reg;
505 	struct i2c_msg msg;
506 	int ret;
507 
508 	/*
509 	 * Send out the register address...
510 	 */
511 	msg.addr = client->addr;
512 	msg.flags = 0;
513 	msg.len = 1;
514 	msg.buf = &data;
515 	ret = i2c_transfer(client->adapter, &msg, 1);
516 	if (ret < 0) {
517 		printk(KERN_ERR "Error %d on register write\n", ret);
518 		return ret;
519 	}
520 	/*
521 	 * ...then read back the result.
522 	 */
523 	msg.flags = I2C_M_RD;
524 	ret = i2c_transfer(client->adapter, &msg, 1);
525 	if (ret >= 0) {
526 		*value = data;
527 		ret = 0;
528 	}
529 	return ret;
530 }
531 
532 
533 static int ov7670_write_i2c(struct v4l2_subdev *sd, unsigned char reg,
534 		unsigned char value)
535 {
536 	struct i2c_client *client = v4l2_get_subdevdata(sd);
537 	struct i2c_msg msg;
538 	unsigned char data[2] = { reg, value };
539 	int ret;
540 
541 	msg.addr = client->addr;
542 	msg.flags = 0;
543 	msg.len = 2;
544 	msg.buf = data;
545 	ret = i2c_transfer(client->adapter, &msg, 1);
546 	if (ret > 0)
547 		ret = 0;
548 	if (reg == REG_COM7 && (value & COM7_RESET))
549 		msleep(5);  /* Wait for reset to run */
550 	return ret;
551 }
552 
553 static int ov7670_read(struct v4l2_subdev *sd, unsigned char reg,
554 		unsigned char *value)
555 {
556 	struct ov7670_info *info = to_state(sd);
557 	if (info->use_smbus)
558 		return ov7670_read_smbus(sd, reg, value);
559 	else
560 		return ov7670_read_i2c(sd, reg, value);
561 }
562 
563 static int ov7670_write(struct v4l2_subdev *sd, unsigned char reg,
564 		unsigned char value)
565 {
566 	struct ov7670_info *info = to_state(sd);
567 	if (info->use_smbus)
568 		return ov7670_write_smbus(sd, reg, value);
569 	else
570 		return ov7670_write_i2c(sd, reg, value);
571 }
572 
573 /*
574  * Write a list of register settings; ff/ff stops the process.
575  */
576 static int ov7670_write_array(struct v4l2_subdev *sd, struct regval_list *vals)
577 {
578 	while (vals->reg_num != 0xff || vals->value != 0xff) {
579 		int ret = ov7670_write(sd, vals->reg_num, vals->value);
580 		if (ret < 0)
581 			return ret;
582 		vals++;
583 	}
584 	return 0;
585 }
586 
587 
588 /*
589  * Stuff that knows about the sensor.
590  */
591 static int ov7670_reset(struct v4l2_subdev *sd, u32 val)
592 {
593 	ov7670_write(sd, REG_COM7, COM7_RESET);
594 	msleep(1);
595 	return 0;
596 }
597 
598 
599 static int ov7670_init(struct v4l2_subdev *sd, u32 val)
600 {
601 	return ov7670_write_array(sd, ov7670_default_regs);
602 }
603 
604 
605 
606 static int ov7670_detect(struct v4l2_subdev *sd)
607 {
608 	unsigned char v;
609 	int ret;
610 
611 	ret = ov7670_init(sd, 0);
612 	if (ret < 0)
613 		return ret;
614 	ret = ov7670_read(sd, REG_MIDH, &v);
615 	if (ret < 0)
616 		return ret;
617 	if (v != 0x7f) /* OV manuf. id. */
618 		return -ENODEV;
619 	ret = ov7670_read(sd, REG_MIDL, &v);
620 	if (ret < 0)
621 		return ret;
622 	if (v != 0xa2)
623 		return -ENODEV;
624 	/*
625 	 * OK, we know we have an OmniVision chip...but which one?
626 	 */
627 	ret = ov7670_read(sd, REG_PID, &v);
628 	if (ret < 0)
629 		return ret;
630 	if (v != 0x76)  /* PID + VER = 0x76 / 0x73 */
631 		return -ENODEV;
632 	ret = ov7670_read(sd, REG_VER, &v);
633 	if (ret < 0)
634 		return ret;
635 	if (v != 0x73)  /* PID + VER = 0x76 / 0x73 */
636 		return -ENODEV;
637 	return 0;
638 }
639 
640 
641 /*
642  * Store information about the video data format.  The color matrix
643  * is deeply tied into the format, so keep the relevant values here.
644  * The magic matrix numbers come from OmniVision.
645  */
646 static struct ov7670_format_struct {
647 	enum v4l2_mbus_pixelcode mbus_code;
648 	enum v4l2_colorspace colorspace;
649 	struct regval_list *regs;
650 	int cmatrix[CMATRIX_LEN];
651 } ov7670_formats[] = {
652 	{
653 		.mbus_code	= V4L2_MBUS_FMT_YUYV8_2X8,
654 		.colorspace	= V4L2_COLORSPACE_JPEG,
655 		.regs 		= ov7670_fmt_yuv422,
656 		.cmatrix	= { 128, -128, 0, -34, -94, 128 },
657 	},
658 	{
659 		.mbus_code	= V4L2_MBUS_FMT_RGB444_2X8_PADHI_LE,
660 		.colorspace	= V4L2_COLORSPACE_SRGB,
661 		.regs		= ov7670_fmt_rgb444,
662 		.cmatrix	= { 179, -179, 0, -61, -176, 228 },
663 	},
664 	{
665 		.mbus_code	= V4L2_MBUS_FMT_RGB565_2X8_LE,
666 		.colorspace	= V4L2_COLORSPACE_SRGB,
667 		.regs		= ov7670_fmt_rgb565,
668 		.cmatrix	= { 179, -179, 0, -61, -176, 228 },
669 	},
670 	{
671 		.mbus_code	= V4L2_MBUS_FMT_SBGGR8_1X8,
672 		.colorspace	= V4L2_COLORSPACE_SRGB,
673 		.regs 		= ov7670_fmt_raw,
674 		.cmatrix	= { 0, 0, 0, 0, 0, 0 },
675 	},
676 };
677 #define N_OV7670_FMTS ARRAY_SIZE(ov7670_formats)
678 
679 
680 /*
681  * Then there is the issue of window sizes.  Try to capture the info here.
682  */
683 
684 /*
685  * QCIF mode is done (by OV) in a very strange way - it actually looks like
686  * VGA with weird scaling options - they do *not* use the canned QCIF mode
687  * which is allegedly provided by the sensor.  So here's the weird register
688  * settings.
689  */
690 static struct regval_list ov7670_qcif_regs[] = {
691 	{ REG_COM3, COM3_SCALEEN|COM3_DCWEN },
692 	{ REG_COM3, COM3_DCWEN },
693 	{ REG_COM14, COM14_DCWEN | 0x01},
694 	{ 0x73, 0xf1 },
695 	{ 0xa2, 0x52 },
696 	{ 0x7b, 0x1c },
697 	{ 0x7c, 0x28 },
698 	{ 0x7d, 0x3c },
699 	{ 0x7f, 0x69 },
700 	{ REG_COM9, 0x38 },
701 	{ 0xa1, 0x0b },
702 	{ 0x74, 0x19 },
703 	{ 0x9a, 0x80 },
704 	{ 0x43, 0x14 },
705 	{ REG_COM13, 0xc0 },
706 	{ 0xff, 0xff },
707 };
708 
709 static struct ov7670_win_size ov7670_win_sizes[] = {
710 	/* VGA */
711 	{
712 		.width		= VGA_WIDTH,
713 		.height		= VGA_HEIGHT,
714 		.com7_bit	= COM7_FMT_VGA,
715 		.hstart		= 158,	/* These values from */
716 		.hstop		=  14,	/* Omnivision */
717 		.vstart		=  10,
718 		.vstop		= 490,
719 		.regs		= NULL,
720 	},
721 	/* CIF */
722 	{
723 		.width		= CIF_WIDTH,
724 		.height		= CIF_HEIGHT,
725 		.com7_bit	= COM7_FMT_CIF,
726 		.hstart		= 170,	/* Empirically determined */
727 		.hstop		=  90,
728 		.vstart		=  14,
729 		.vstop		= 494,
730 		.regs		= NULL,
731 	},
732 	/* QVGA */
733 	{
734 		.width		= QVGA_WIDTH,
735 		.height		= QVGA_HEIGHT,
736 		.com7_bit	= COM7_FMT_QVGA,
737 		.hstart		= 168,	/* Empirically determined */
738 		.hstop		=  24,
739 		.vstart		=  12,
740 		.vstop		= 492,
741 		.regs		= NULL,
742 	},
743 	/* QCIF */
744 	{
745 		.width		= QCIF_WIDTH,
746 		.height		= QCIF_HEIGHT,
747 		.com7_bit	= COM7_FMT_VGA, /* see comment above */
748 		.hstart		= 456,	/* Empirically determined */
749 		.hstop		=  24,
750 		.vstart		=  14,
751 		.vstop		= 494,
752 		.regs		= ov7670_qcif_regs,
753 	}
754 };
755 
756 static struct ov7670_win_size ov7675_win_sizes[] = {
757 	/*
758 	 * Currently, only VGA is supported. Theoretically it could be possible
759 	 * to support CIF, QVGA and QCIF too. Taking values for ov7670 as a
760 	 * base and tweak them empirically could be required.
761 	 */
762 	{
763 		.width		= VGA_WIDTH,
764 		.height		= VGA_HEIGHT,
765 		.com7_bit	= COM7_FMT_VGA,
766 		.hstart		= 158,	/* These values from */
767 		.hstop		=  14,	/* Omnivision */
768 		.vstart		=  14,  /* Empirically determined */
769 		.vstop		= 494,
770 		.regs		= NULL,
771 	}
772 };
773 
774 static void ov7675_get_framerate(struct v4l2_subdev *sd,
775 				 struct v4l2_fract *tpf)
776 {
777 	struct ov7670_info *info = to_state(sd);
778 	u32 clkrc = info->clkrc;
779 	int pll_factor;
780 
781 	if (info->pll_bypass)
782 		pll_factor = 1;
783 	else
784 		pll_factor = PLL_FACTOR;
785 
786 	clkrc++;
787 	if (info->fmt->mbus_code == V4L2_MBUS_FMT_SBGGR8_1X8)
788 		clkrc = (clkrc >> 1);
789 
790 	tpf->numerator = 1;
791 	tpf->denominator = (5 * pll_factor * info->clock_speed) /
792 			(4 * clkrc);
793 }
794 
795 static int ov7675_set_framerate(struct v4l2_subdev *sd,
796 				 struct v4l2_fract *tpf)
797 {
798 	struct ov7670_info *info = to_state(sd);
799 	u32 clkrc;
800 	int pll_factor;
801 	int ret;
802 
803 	/*
804 	 * The formula is fps = 5/4*pixclk for YUV/RGB and
805 	 * fps = 5/2*pixclk for RAW.
806 	 *
807 	 * pixclk = clock_speed / (clkrc + 1) * PLLfactor
808 	 *
809 	 */
810 	if (info->pll_bypass) {
811 		pll_factor = 1;
812 		ret = ov7670_write(sd, REG_DBLV, DBLV_BYPASS);
813 	} else {
814 		pll_factor = PLL_FACTOR;
815 		ret = ov7670_write(sd, REG_DBLV, DBLV_X4);
816 	}
817 	if (ret < 0)
818 		return ret;
819 
820 	if (tpf->numerator == 0 || tpf->denominator == 0) {
821 		clkrc = 0;
822 	} else {
823 		clkrc = (5 * pll_factor * info->clock_speed * tpf->numerator) /
824 			(4 * tpf->denominator);
825 		if (info->fmt->mbus_code == V4L2_MBUS_FMT_SBGGR8_1X8)
826 			clkrc = (clkrc << 1);
827 		clkrc--;
828 	}
829 
830 	/*
831 	 * The datasheet claims that clkrc = 0 will divide the input clock by 1
832 	 * but we've checked with an oscilloscope that it divides by 2 instead.
833 	 * So, if clkrc = 0 just bypass the divider.
834 	 */
835 	if (clkrc <= 0)
836 		clkrc = CLK_EXT;
837 	else if (clkrc > CLK_SCALE)
838 		clkrc = CLK_SCALE;
839 	info->clkrc = clkrc;
840 
841 	/* Recalculate frame rate */
842 	ov7675_get_framerate(sd, tpf);
843 
844 	ret = ov7670_write(sd, REG_CLKRC, info->clkrc);
845 	if (ret < 0)
846 		return ret;
847 
848 	return ov7670_write(sd, REG_DBLV, DBLV_X4);
849 }
850 
851 static void ov7670_get_framerate_legacy(struct v4l2_subdev *sd,
852 				 struct v4l2_fract *tpf)
853 {
854 	struct ov7670_info *info = to_state(sd);
855 
856 	tpf->numerator = 1;
857 	tpf->denominator = info->clock_speed;
858 	if ((info->clkrc & CLK_EXT) == 0 && (info->clkrc & CLK_SCALE) > 1)
859 		tpf->denominator /= (info->clkrc & CLK_SCALE);
860 }
861 
862 static int ov7670_set_framerate_legacy(struct v4l2_subdev *sd,
863 					struct v4l2_fract *tpf)
864 {
865 	struct ov7670_info *info = to_state(sd);
866 	int div;
867 
868 	if (tpf->numerator == 0 || tpf->denominator == 0)
869 		div = 1;  /* Reset to full rate */
870 	else
871 		div = (tpf->numerator * info->clock_speed) / tpf->denominator;
872 	if (div == 0)
873 		div = 1;
874 	else if (div > CLK_SCALE)
875 		div = CLK_SCALE;
876 	info->clkrc = (info->clkrc & 0x80) | div;
877 	tpf->numerator = 1;
878 	tpf->denominator = info->clock_speed / div;
879 	return ov7670_write(sd, REG_CLKRC, info->clkrc);
880 }
881 
882 /*
883  * Store a set of start/stop values into the camera.
884  */
885 static int ov7670_set_hw(struct v4l2_subdev *sd, int hstart, int hstop,
886 		int vstart, int vstop)
887 {
888 	int ret;
889 	unsigned char v;
890 /*
891  * Horizontal: 11 bits, top 8 live in hstart and hstop.  Bottom 3 of
892  * hstart are in href[2:0], bottom 3 of hstop in href[5:3].  There is
893  * a mystery "edge offset" value in the top two bits of href.
894  */
895 	ret =  ov7670_write(sd, REG_HSTART, (hstart >> 3) & 0xff);
896 	ret += ov7670_write(sd, REG_HSTOP, (hstop >> 3) & 0xff);
897 	ret += ov7670_read(sd, REG_HREF, &v);
898 	v = (v & 0xc0) | ((hstop & 0x7) << 3) | (hstart & 0x7);
899 	msleep(10);
900 	ret += ov7670_write(sd, REG_HREF, v);
901 /*
902  * Vertical: similar arrangement, but only 10 bits.
903  */
904 	ret += ov7670_write(sd, REG_VSTART, (vstart >> 2) & 0xff);
905 	ret += ov7670_write(sd, REG_VSTOP, (vstop >> 2) & 0xff);
906 	ret += ov7670_read(sd, REG_VREF, &v);
907 	v = (v & 0xf0) | ((vstop & 0x3) << 2) | (vstart & 0x3);
908 	msleep(10);
909 	ret += ov7670_write(sd, REG_VREF, v);
910 	return ret;
911 }
912 
913 
914 static int ov7670_enum_mbus_fmt(struct v4l2_subdev *sd, unsigned index,
915 					enum v4l2_mbus_pixelcode *code)
916 {
917 	if (index >= N_OV7670_FMTS)
918 		return -EINVAL;
919 
920 	*code = ov7670_formats[index].mbus_code;
921 	return 0;
922 }
923 
924 static int ov7670_try_fmt_internal(struct v4l2_subdev *sd,
925 		struct v4l2_mbus_framefmt *fmt,
926 		struct ov7670_format_struct **ret_fmt,
927 		struct ov7670_win_size **ret_wsize)
928 {
929 	int index, i;
930 	struct ov7670_win_size *wsize;
931 	struct ov7670_info *info = to_state(sd);
932 	unsigned int n_win_sizes = info->devtype->n_win_sizes;
933 	unsigned int win_sizes_limit = n_win_sizes;
934 
935 	for (index = 0; index < N_OV7670_FMTS; index++)
936 		if (ov7670_formats[index].mbus_code == fmt->code)
937 			break;
938 	if (index >= N_OV7670_FMTS) {
939 		/* default to first format */
940 		index = 0;
941 		fmt->code = ov7670_formats[0].mbus_code;
942 	}
943 	if (ret_fmt != NULL)
944 		*ret_fmt = ov7670_formats + index;
945 	/*
946 	 * Fields: the OV devices claim to be progressive.
947 	 */
948 	fmt->field = V4L2_FIELD_NONE;
949 
950 	/*
951 	 * Don't consider values that don't match min_height and min_width
952 	 * constraints.
953 	 */
954 	if (info->min_width || info->min_height)
955 		for (i = 0; i < n_win_sizes; i++) {
956 			wsize = info->devtype->win_sizes + i;
957 
958 			if (wsize->width < info->min_width ||
959 				wsize->height < info->min_height) {
960 				win_sizes_limit = i;
961 				break;
962 			}
963 		}
964 	/*
965 	 * Round requested image size down to the nearest
966 	 * we support, but not below the smallest.
967 	 */
968 	for (wsize = info->devtype->win_sizes;
969 	     wsize < info->devtype->win_sizes + win_sizes_limit; wsize++)
970 		if (fmt->width >= wsize->width && fmt->height >= wsize->height)
971 			break;
972 	if (wsize >= info->devtype->win_sizes + win_sizes_limit)
973 		wsize--;   /* Take the smallest one */
974 	if (ret_wsize != NULL)
975 		*ret_wsize = wsize;
976 	/*
977 	 * Note the size we'll actually handle.
978 	 */
979 	fmt->width = wsize->width;
980 	fmt->height = wsize->height;
981 	fmt->colorspace = ov7670_formats[index].colorspace;
982 	return 0;
983 }
984 
985 static int ov7670_try_mbus_fmt(struct v4l2_subdev *sd,
986 			    struct v4l2_mbus_framefmt *fmt)
987 {
988 	return ov7670_try_fmt_internal(sd, fmt, NULL, NULL);
989 }
990 
991 /*
992  * Set a format.
993  */
994 static int ov7670_s_mbus_fmt(struct v4l2_subdev *sd,
995 			  struct v4l2_mbus_framefmt *fmt)
996 {
997 	struct ov7670_format_struct *ovfmt;
998 	struct ov7670_win_size *wsize;
999 	struct ov7670_info *info = to_state(sd);
1000 	unsigned char com7;
1001 	int ret;
1002 
1003 	ret = ov7670_try_fmt_internal(sd, fmt, &ovfmt, &wsize);
1004 
1005 	if (ret)
1006 		return ret;
1007 	/*
1008 	 * COM7 is a pain in the ass, it doesn't like to be read then
1009 	 * quickly written afterward.  But we have everything we need
1010 	 * to set it absolutely here, as long as the format-specific
1011 	 * register sets list it first.
1012 	 */
1013 	com7 = ovfmt->regs[0].value;
1014 	com7 |= wsize->com7_bit;
1015 	ov7670_write(sd, REG_COM7, com7);
1016 	/*
1017 	 * Now write the rest of the array.  Also store start/stops
1018 	 */
1019 	ov7670_write_array(sd, ovfmt->regs + 1);
1020 	ov7670_set_hw(sd, wsize->hstart, wsize->hstop, wsize->vstart,
1021 			wsize->vstop);
1022 	ret = 0;
1023 	if (wsize->regs)
1024 		ret = ov7670_write_array(sd, wsize->regs);
1025 	info->fmt = ovfmt;
1026 
1027 	/*
1028 	 * If we're running RGB565, we must rewrite clkrc after setting
1029 	 * the other parameters or the image looks poor.  If we're *not*
1030 	 * doing RGB565, we must not rewrite clkrc or the image looks
1031 	 * *really* poor.
1032 	 *
1033 	 * (Update) Now that we retain clkrc state, we should be able
1034 	 * to write it unconditionally, and that will make the frame
1035 	 * rate persistent too.
1036 	 */
1037 	if (ret == 0)
1038 		ret = ov7670_write(sd, REG_CLKRC, info->clkrc);
1039 	return 0;
1040 }
1041 
1042 /*
1043  * Implement G/S_PARM.  There is a "high quality" mode we could try
1044  * to do someday; for now, we just do the frame rate tweak.
1045  */
1046 static int ov7670_g_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
1047 {
1048 	struct v4l2_captureparm *cp = &parms->parm.capture;
1049 	struct ov7670_info *info = to_state(sd);
1050 
1051 	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1052 		return -EINVAL;
1053 
1054 	memset(cp, 0, sizeof(struct v4l2_captureparm));
1055 	cp->capability = V4L2_CAP_TIMEPERFRAME;
1056 	info->devtype->get_framerate(sd, &cp->timeperframe);
1057 
1058 	return 0;
1059 }
1060 
1061 static int ov7670_s_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
1062 {
1063 	struct v4l2_captureparm *cp = &parms->parm.capture;
1064 	struct v4l2_fract *tpf = &cp->timeperframe;
1065 	struct ov7670_info *info = to_state(sd);
1066 
1067 	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1068 		return -EINVAL;
1069 	if (cp->extendedmode != 0)
1070 		return -EINVAL;
1071 
1072 	return info->devtype->set_framerate(sd, tpf);
1073 }
1074 
1075 
1076 /*
1077  * Frame intervals.  Since frame rates are controlled with the clock
1078  * divider, we can only do 30/n for integer n values.  So no continuous
1079  * or stepwise options.  Here we just pick a handful of logical values.
1080  */
1081 
1082 static int ov7670_frame_rates[] = { 30, 15, 10, 5, 1 };
1083 
1084 static int ov7670_enum_frameintervals(struct v4l2_subdev *sd,
1085 		struct v4l2_frmivalenum *interval)
1086 {
1087 	if (interval->index >= ARRAY_SIZE(ov7670_frame_rates))
1088 		return -EINVAL;
1089 	interval->type = V4L2_FRMIVAL_TYPE_DISCRETE;
1090 	interval->discrete.numerator = 1;
1091 	interval->discrete.denominator = ov7670_frame_rates[interval->index];
1092 	return 0;
1093 }
1094 
1095 /*
1096  * Frame size enumeration
1097  */
1098 static int ov7670_enum_framesizes(struct v4l2_subdev *sd,
1099 		struct v4l2_frmsizeenum *fsize)
1100 {
1101 	struct ov7670_info *info = to_state(sd);
1102 	int i;
1103 	int num_valid = -1;
1104 	__u32 index = fsize->index;
1105 	unsigned int n_win_sizes = info->devtype->n_win_sizes;
1106 
1107 	/*
1108 	 * If a minimum width/height was requested, filter out the capture
1109 	 * windows that fall outside that.
1110 	 */
1111 	for (i = 0; i < n_win_sizes; i++) {
1112 		struct ov7670_win_size *win = &info->devtype->win_sizes[i];
1113 		if (info->min_width && win->width < info->min_width)
1114 			continue;
1115 		if (info->min_height && win->height < info->min_height)
1116 			continue;
1117 		if (index == ++num_valid) {
1118 			fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
1119 			fsize->discrete.width = win->width;
1120 			fsize->discrete.height = win->height;
1121 			return 0;
1122 		}
1123 	}
1124 
1125 	return -EINVAL;
1126 }
1127 
1128 /*
1129  * Code for dealing with controls.
1130  */
1131 
1132 static int ov7670_store_cmatrix(struct v4l2_subdev *sd,
1133 		int matrix[CMATRIX_LEN])
1134 {
1135 	int i, ret;
1136 	unsigned char signbits = 0;
1137 
1138 	/*
1139 	 * Weird crap seems to exist in the upper part of
1140 	 * the sign bits register, so let's preserve it.
1141 	 */
1142 	ret = ov7670_read(sd, REG_CMATRIX_SIGN, &signbits);
1143 	signbits &= 0xc0;
1144 
1145 	for (i = 0; i < CMATRIX_LEN; i++) {
1146 		unsigned char raw;
1147 
1148 		if (matrix[i] < 0) {
1149 			signbits |= (1 << i);
1150 			if (matrix[i] < -255)
1151 				raw = 0xff;
1152 			else
1153 				raw = (-1 * matrix[i]) & 0xff;
1154 		}
1155 		else {
1156 			if (matrix[i] > 255)
1157 				raw = 0xff;
1158 			else
1159 				raw = matrix[i] & 0xff;
1160 		}
1161 		ret += ov7670_write(sd, REG_CMATRIX_BASE + i, raw);
1162 	}
1163 	ret += ov7670_write(sd, REG_CMATRIX_SIGN, signbits);
1164 	return ret;
1165 }
1166 
1167 
1168 /*
1169  * Hue also requires messing with the color matrix.  It also requires
1170  * trig functions, which tend not to be well supported in the kernel.
1171  * So here is a simple table of sine values, 0-90 degrees, in steps
1172  * of five degrees.  Values are multiplied by 1000.
1173  *
1174  * The following naive approximate trig functions require an argument
1175  * carefully limited to -180 <= theta <= 180.
1176  */
1177 #define SIN_STEP 5
1178 static const int ov7670_sin_table[] = {
1179 	   0,	 87,   173,   258,   342,   422,
1180 	 499,	573,   642,   707,   766,   819,
1181 	 866,	906,   939,   965,   984,   996,
1182 	1000
1183 };
1184 
1185 static int ov7670_sine(int theta)
1186 {
1187 	int chs = 1;
1188 	int sine;
1189 
1190 	if (theta < 0) {
1191 		theta = -theta;
1192 		chs = -1;
1193 	}
1194 	if (theta <= 90)
1195 		sine = ov7670_sin_table[theta/SIN_STEP];
1196 	else {
1197 		theta -= 90;
1198 		sine = 1000 - ov7670_sin_table[theta/SIN_STEP];
1199 	}
1200 	return sine*chs;
1201 }
1202 
1203 static int ov7670_cosine(int theta)
1204 {
1205 	theta = 90 - theta;
1206 	if (theta > 180)
1207 		theta -= 360;
1208 	else if (theta < -180)
1209 		theta += 360;
1210 	return ov7670_sine(theta);
1211 }
1212 
1213 
1214 
1215 
1216 static void ov7670_calc_cmatrix(struct ov7670_info *info,
1217 		int matrix[CMATRIX_LEN], int sat, int hue)
1218 {
1219 	int i;
1220 	/*
1221 	 * Apply the current saturation setting first.
1222 	 */
1223 	for (i = 0; i < CMATRIX_LEN; i++)
1224 		matrix[i] = (info->fmt->cmatrix[i] * sat) >> 7;
1225 	/*
1226 	 * Then, if need be, rotate the hue value.
1227 	 */
1228 	if (hue != 0) {
1229 		int sinth, costh, tmpmatrix[CMATRIX_LEN];
1230 
1231 		memcpy(tmpmatrix, matrix, CMATRIX_LEN*sizeof(int));
1232 		sinth = ov7670_sine(hue);
1233 		costh = ov7670_cosine(hue);
1234 
1235 		matrix[0] = (matrix[3]*sinth + matrix[0]*costh)/1000;
1236 		matrix[1] = (matrix[4]*sinth + matrix[1]*costh)/1000;
1237 		matrix[2] = (matrix[5]*sinth + matrix[2]*costh)/1000;
1238 		matrix[3] = (matrix[3]*costh - matrix[0]*sinth)/1000;
1239 		matrix[4] = (matrix[4]*costh - matrix[1]*sinth)/1000;
1240 		matrix[5] = (matrix[5]*costh - matrix[2]*sinth)/1000;
1241 	}
1242 }
1243 
1244 
1245 
1246 static int ov7670_s_sat_hue(struct v4l2_subdev *sd, int sat, int hue)
1247 {
1248 	struct ov7670_info *info = to_state(sd);
1249 	int matrix[CMATRIX_LEN];
1250 	int ret;
1251 
1252 	ov7670_calc_cmatrix(info, matrix, sat, hue);
1253 	ret = ov7670_store_cmatrix(sd, matrix);
1254 	return ret;
1255 }
1256 
1257 
1258 /*
1259  * Some weird registers seem to store values in a sign/magnitude format!
1260  */
1261 
1262 static unsigned char ov7670_abs_to_sm(unsigned char v)
1263 {
1264 	if (v > 127)
1265 		return v & 0x7f;
1266 	return (128 - v) | 0x80;
1267 }
1268 
1269 static int ov7670_s_brightness(struct v4l2_subdev *sd, int value)
1270 {
1271 	unsigned char com8 = 0, v;
1272 	int ret;
1273 
1274 	ov7670_read(sd, REG_COM8, &com8);
1275 	com8 &= ~COM8_AEC;
1276 	ov7670_write(sd, REG_COM8, com8);
1277 	v = ov7670_abs_to_sm(value);
1278 	ret = ov7670_write(sd, REG_BRIGHT, v);
1279 	return ret;
1280 }
1281 
1282 static int ov7670_s_contrast(struct v4l2_subdev *sd, int value)
1283 {
1284 	return ov7670_write(sd, REG_CONTRAS, (unsigned char) value);
1285 }
1286 
1287 static int ov7670_s_hflip(struct v4l2_subdev *sd, int value)
1288 {
1289 	unsigned char v = 0;
1290 	int ret;
1291 
1292 	ret = ov7670_read(sd, REG_MVFP, &v);
1293 	if (value)
1294 		v |= MVFP_MIRROR;
1295 	else
1296 		v &= ~MVFP_MIRROR;
1297 	msleep(10);  /* FIXME */
1298 	ret += ov7670_write(sd, REG_MVFP, v);
1299 	return ret;
1300 }
1301 
1302 static int ov7670_s_vflip(struct v4l2_subdev *sd, int value)
1303 {
1304 	unsigned char v = 0;
1305 	int ret;
1306 
1307 	ret = ov7670_read(sd, REG_MVFP, &v);
1308 	if (value)
1309 		v |= MVFP_FLIP;
1310 	else
1311 		v &= ~MVFP_FLIP;
1312 	msleep(10);  /* FIXME */
1313 	ret += ov7670_write(sd, REG_MVFP, v);
1314 	return ret;
1315 }
1316 
1317 /*
1318  * GAIN is split between REG_GAIN and REG_VREF[7:6].  If one believes
1319  * the data sheet, the VREF parts should be the most significant, but
1320  * experience shows otherwise.  There seems to be little value in
1321  * messing with the VREF bits, so we leave them alone.
1322  */
1323 static int ov7670_g_gain(struct v4l2_subdev *sd, __s32 *value)
1324 {
1325 	int ret;
1326 	unsigned char gain;
1327 
1328 	ret = ov7670_read(sd, REG_GAIN, &gain);
1329 	*value = gain;
1330 	return ret;
1331 }
1332 
1333 static int ov7670_s_gain(struct v4l2_subdev *sd, int value)
1334 {
1335 	int ret;
1336 	unsigned char com8;
1337 
1338 	ret = ov7670_write(sd, REG_GAIN, value & 0xff);
1339 	/* Have to turn off AGC as well */
1340 	if (ret == 0) {
1341 		ret = ov7670_read(sd, REG_COM8, &com8);
1342 		ret = ov7670_write(sd, REG_COM8, com8 & ~COM8_AGC);
1343 	}
1344 	return ret;
1345 }
1346 
1347 /*
1348  * Tweak autogain.
1349  */
1350 static int ov7670_s_autogain(struct v4l2_subdev *sd, int value)
1351 {
1352 	int ret;
1353 	unsigned char com8;
1354 
1355 	ret = ov7670_read(sd, REG_COM8, &com8);
1356 	if (ret == 0) {
1357 		if (value)
1358 			com8 |= COM8_AGC;
1359 		else
1360 			com8 &= ~COM8_AGC;
1361 		ret = ov7670_write(sd, REG_COM8, com8);
1362 	}
1363 	return ret;
1364 }
1365 
1366 static int ov7670_s_exp(struct v4l2_subdev *sd, int value)
1367 {
1368 	int ret;
1369 	unsigned char com1, com8, aech, aechh;
1370 
1371 	ret = ov7670_read(sd, REG_COM1, &com1) +
1372 		ov7670_read(sd, REG_COM8, &com8);
1373 		ov7670_read(sd, REG_AECHH, &aechh);
1374 	if (ret)
1375 		return ret;
1376 
1377 	com1 = (com1 & 0xfc) | (value & 0x03);
1378 	aech = (value >> 2) & 0xff;
1379 	aechh = (aechh & 0xc0) | ((value >> 10) & 0x3f);
1380 	ret = ov7670_write(sd, REG_COM1, com1) +
1381 		ov7670_write(sd, REG_AECH, aech) +
1382 		ov7670_write(sd, REG_AECHH, aechh);
1383 	/* Have to turn off AEC as well */
1384 	if (ret == 0)
1385 		ret = ov7670_write(sd, REG_COM8, com8 & ~COM8_AEC);
1386 	return ret;
1387 }
1388 
1389 /*
1390  * Tweak autoexposure.
1391  */
1392 static int ov7670_s_autoexp(struct v4l2_subdev *sd,
1393 		enum v4l2_exposure_auto_type value)
1394 {
1395 	int ret;
1396 	unsigned char com8;
1397 
1398 	ret = ov7670_read(sd, REG_COM8, &com8);
1399 	if (ret == 0) {
1400 		if (value == V4L2_EXPOSURE_AUTO)
1401 			com8 |= COM8_AEC;
1402 		else
1403 			com8 &= ~COM8_AEC;
1404 		ret = ov7670_write(sd, REG_COM8, com8);
1405 	}
1406 	return ret;
1407 }
1408 
1409 
1410 static int ov7670_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
1411 {
1412 	struct v4l2_subdev *sd = to_sd(ctrl);
1413 	struct ov7670_info *info = to_state(sd);
1414 
1415 	switch (ctrl->id) {
1416 	case V4L2_CID_AUTOGAIN:
1417 		return ov7670_g_gain(sd, &info->gain->val);
1418 	}
1419 	return -EINVAL;
1420 }
1421 
1422 static int ov7670_s_ctrl(struct v4l2_ctrl *ctrl)
1423 {
1424 	struct v4l2_subdev *sd = to_sd(ctrl);
1425 	struct ov7670_info *info = to_state(sd);
1426 
1427 	switch (ctrl->id) {
1428 	case V4L2_CID_BRIGHTNESS:
1429 		return ov7670_s_brightness(sd, ctrl->val);
1430 	case V4L2_CID_CONTRAST:
1431 		return ov7670_s_contrast(sd, ctrl->val);
1432 	case V4L2_CID_SATURATION:
1433 		return ov7670_s_sat_hue(sd,
1434 				info->saturation->val, info->hue->val);
1435 	case V4L2_CID_VFLIP:
1436 		return ov7670_s_vflip(sd, ctrl->val);
1437 	case V4L2_CID_HFLIP:
1438 		return ov7670_s_hflip(sd, ctrl->val);
1439 	case V4L2_CID_AUTOGAIN:
1440 		/* Only set manual gain if auto gain is not explicitly
1441 		   turned on. */
1442 		if (!ctrl->val) {
1443 			/* ov7670_s_gain turns off auto gain */
1444 			return ov7670_s_gain(sd, info->gain->val);
1445 		}
1446 		return ov7670_s_autogain(sd, ctrl->val);
1447 	case V4L2_CID_EXPOSURE_AUTO:
1448 		/* Only set manual exposure if auto exposure is not explicitly
1449 		   turned on. */
1450 		if (ctrl->val == V4L2_EXPOSURE_MANUAL) {
1451 			/* ov7670_s_exp turns off auto exposure */
1452 			return ov7670_s_exp(sd, info->exposure->val);
1453 		}
1454 		return ov7670_s_autoexp(sd, ctrl->val);
1455 	}
1456 	return -EINVAL;
1457 }
1458 
1459 static const struct v4l2_ctrl_ops ov7670_ctrl_ops = {
1460 	.s_ctrl = ov7670_s_ctrl,
1461 	.g_volatile_ctrl = ov7670_g_volatile_ctrl,
1462 };
1463 
1464 #ifdef CONFIG_VIDEO_ADV_DEBUG
1465 static int ov7670_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
1466 {
1467 	unsigned char val = 0;
1468 	int ret;
1469 
1470 	ret = ov7670_read(sd, reg->reg & 0xff, &val);
1471 	reg->val = val;
1472 	reg->size = 1;
1473 	return ret;
1474 }
1475 
1476 static int ov7670_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
1477 {
1478 	ov7670_write(sd, reg->reg & 0xff, reg->val & 0xff);
1479 	return 0;
1480 }
1481 #endif
1482 
1483 /* ----------------------------------------------------------------------- */
1484 
1485 static const struct v4l2_subdev_core_ops ov7670_core_ops = {
1486 	.reset = ov7670_reset,
1487 	.init = ov7670_init,
1488 #ifdef CONFIG_VIDEO_ADV_DEBUG
1489 	.g_register = ov7670_g_register,
1490 	.s_register = ov7670_s_register,
1491 #endif
1492 };
1493 
1494 static const struct v4l2_subdev_video_ops ov7670_video_ops = {
1495 	.enum_mbus_fmt = ov7670_enum_mbus_fmt,
1496 	.try_mbus_fmt = ov7670_try_mbus_fmt,
1497 	.s_mbus_fmt = ov7670_s_mbus_fmt,
1498 	.s_parm = ov7670_s_parm,
1499 	.g_parm = ov7670_g_parm,
1500 	.enum_frameintervals = ov7670_enum_frameintervals,
1501 	.enum_framesizes = ov7670_enum_framesizes,
1502 };
1503 
1504 static const struct v4l2_subdev_ops ov7670_ops = {
1505 	.core = &ov7670_core_ops,
1506 	.video = &ov7670_video_ops,
1507 };
1508 
1509 /* ----------------------------------------------------------------------- */
1510 
1511 static const struct ov7670_devtype ov7670_devdata[] = {
1512 	[MODEL_OV7670] = {
1513 		.win_sizes = ov7670_win_sizes,
1514 		.n_win_sizes = ARRAY_SIZE(ov7670_win_sizes),
1515 		.set_framerate = ov7670_set_framerate_legacy,
1516 		.get_framerate = ov7670_get_framerate_legacy,
1517 	},
1518 	[MODEL_OV7675] = {
1519 		.win_sizes = ov7675_win_sizes,
1520 		.n_win_sizes = ARRAY_SIZE(ov7675_win_sizes),
1521 		.set_framerate = ov7675_set_framerate,
1522 		.get_framerate = ov7675_get_framerate,
1523 	},
1524 };
1525 
1526 static int ov7670_probe(struct i2c_client *client,
1527 			const struct i2c_device_id *id)
1528 {
1529 	struct v4l2_fract tpf;
1530 	struct v4l2_subdev *sd;
1531 	struct ov7670_info *info;
1532 	int ret;
1533 
1534 	info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
1535 	if (info == NULL)
1536 		return -ENOMEM;
1537 	sd = &info->sd;
1538 	v4l2_i2c_subdev_init(sd, client, &ov7670_ops);
1539 
1540 	info->clock_speed = 30; /* default: a guess */
1541 	if (client->dev.platform_data) {
1542 		struct ov7670_config *config = client->dev.platform_data;
1543 
1544 		/*
1545 		 * Must apply configuration before initializing device, because it
1546 		 * selects I/O method.
1547 		 */
1548 		info->min_width = config->min_width;
1549 		info->min_height = config->min_height;
1550 		info->use_smbus = config->use_smbus;
1551 
1552 		if (config->clock_speed)
1553 			info->clock_speed = config->clock_speed;
1554 
1555 		/*
1556 		 * It should be allowed for ov7670 too when it is migrated to
1557 		 * the new frame rate formula.
1558 		 */
1559 		if (config->pll_bypass && id->driver_data != MODEL_OV7670)
1560 			info->pll_bypass = true;
1561 
1562 		if (config->pclk_hb_disable)
1563 			info->pclk_hb_disable = true;
1564 	}
1565 
1566 	/* Make sure it's an ov7670 */
1567 	ret = ov7670_detect(sd);
1568 	if (ret) {
1569 		v4l_dbg(1, debug, client,
1570 			"chip found @ 0x%x (%s) is not an ov7670 chip.\n",
1571 			client->addr << 1, client->adapter->name);
1572 		return ret;
1573 	}
1574 	v4l_info(client, "chip found @ 0x%02x (%s)\n",
1575 			client->addr << 1, client->adapter->name);
1576 
1577 	info->devtype = &ov7670_devdata[id->driver_data];
1578 	info->fmt = &ov7670_formats[0];
1579 	info->clkrc = 0;
1580 
1581 	/* Set default frame rate to 30 fps */
1582 	tpf.numerator = 1;
1583 	tpf.denominator = 30;
1584 	info->devtype->set_framerate(sd, &tpf);
1585 
1586 	if (info->pclk_hb_disable)
1587 		ov7670_write(sd, REG_COM10, COM10_PCLK_HB);
1588 
1589 	v4l2_ctrl_handler_init(&info->hdl, 10);
1590 	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1591 			V4L2_CID_BRIGHTNESS, 0, 255, 1, 128);
1592 	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1593 			V4L2_CID_CONTRAST, 0, 127, 1, 64);
1594 	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1595 			V4L2_CID_VFLIP, 0, 1, 1, 0);
1596 	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1597 			V4L2_CID_HFLIP, 0, 1, 1, 0);
1598 	info->saturation = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1599 			V4L2_CID_SATURATION, 0, 256, 1, 128);
1600 	info->hue = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1601 			V4L2_CID_HUE, -180, 180, 5, 0);
1602 	info->gain = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1603 			V4L2_CID_GAIN, 0, 255, 1, 128);
1604 	info->auto_gain = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1605 			V4L2_CID_AUTOGAIN, 0, 1, 1, 1);
1606 	info->exposure = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1607 			V4L2_CID_EXPOSURE, 0, 65535, 1, 500);
1608 	info->auto_exposure = v4l2_ctrl_new_std_menu(&info->hdl, &ov7670_ctrl_ops,
1609 			V4L2_CID_EXPOSURE_AUTO, V4L2_EXPOSURE_MANUAL, 0,
1610 			V4L2_EXPOSURE_AUTO);
1611 	sd->ctrl_handler = &info->hdl;
1612 	if (info->hdl.error) {
1613 		int err = info->hdl.error;
1614 
1615 		v4l2_ctrl_handler_free(&info->hdl);
1616 		return err;
1617 	}
1618 	/*
1619 	 * We have checked empirically that hw allows to read back the gain
1620 	 * value chosen by auto gain but that's not the case for auto exposure.
1621 	 */
1622 	v4l2_ctrl_auto_cluster(2, &info->auto_gain, 0, true);
1623 	v4l2_ctrl_auto_cluster(2, &info->auto_exposure,
1624 			       V4L2_EXPOSURE_MANUAL, false);
1625 	v4l2_ctrl_cluster(2, &info->saturation);
1626 	v4l2_ctrl_handler_setup(&info->hdl);
1627 
1628 	return 0;
1629 }
1630 
1631 
1632 static int ov7670_remove(struct i2c_client *client)
1633 {
1634 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
1635 	struct ov7670_info *info = to_state(sd);
1636 
1637 	v4l2_device_unregister_subdev(sd);
1638 	v4l2_ctrl_handler_free(&info->hdl);
1639 	return 0;
1640 }
1641 
1642 static const struct i2c_device_id ov7670_id[] = {
1643 	{ "ov7670", MODEL_OV7670 },
1644 	{ "ov7675", MODEL_OV7675 },
1645 	{ }
1646 };
1647 MODULE_DEVICE_TABLE(i2c, ov7670_id);
1648 
1649 static struct i2c_driver ov7670_driver = {
1650 	.driver = {
1651 		.owner	= THIS_MODULE,
1652 		.name	= "ov7670",
1653 	},
1654 	.probe		= ov7670_probe,
1655 	.remove		= ov7670_remove,
1656 	.id_table	= ov7670_id,
1657 };
1658 
1659 module_i2c_driver(ov7670_driver);
1660