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/ov7670.h>
24
25MODULE_AUTHOR("Jonathan Corbet <corbet@lwn.net>");
26MODULE_DESCRIPTION("A low-level driver for OmniVision ov7670 sensors");
27MODULE_LICENSE("GPL");
28
29static bool debug;
30module_param(debug, bool, 0644);
31MODULE_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
182enum ov7670_model {
183	MODEL_OV7670 = 0,
184	MODEL_OV7675,
185};
186
187struct 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
198struct 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 */
210struct ov7670_format_struct;  /* coming later */
211struct 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
240static inline struct ov7670_info *to_state(struct v4l2_subdev *sd)
241{
242	return container_of(sd, struct ov7670_info, sd);
243}
244
245static 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
260struct regval_list {
261	unsigned char reg_num;
262	unsigned char value;
263};
264
265static 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
393static 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
409static 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
425static 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
441static 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 */
459static 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
474static 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 */
488static 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
521static 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
541static 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
551static 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 */
564static 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 */
579static 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
587static int ov7670_init(struct v4l2_subdev *sd, u32 val)
588{
589	return ov7670_write_array(sd, ov7670_default_regs);
590}
591
592
593
594static 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 */
634static 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_JPEG,
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 */
678static 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
697static 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
744static 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
762static 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
783static 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
839static 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
850static 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 */
873static 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
902static int ov7670_enum_mbus_fmt(struct v4l2_subdev *sd, unsigned index,
903					u32 *code)
904{
905	if (index >= N_OV7670_FMTS)
906		return -EINVAL;
907
908	*code = ov7670_formats[index].mbus_code;
909	return 0;
910}
911
912static int ov7670_try_fmt_internal(struct v4l2_subdev *sd,
913		struct v4l2_mbus_framefmt *fmt,
914		struct ov7670_format_struct **ret_fmt,
915		struct ov7670_win_size **ret_wsize)
916{
917	int index, i;
918	struct ov7670_win_size *wsize;
919	struct ov7670_info *info = to_state(sd);
920	unsigned int n_win_sizes = info->devtype->n_win_sizes;
921	unsigned int win_sizes_limit = n_win_sizes;
922
923	for (index = 0; index < N_OV7670_FMTS; index++)
924		if (ov7670_formats[index].mbus_code == fmt->code)
925			break;
926	if (index >= N_OV7670_FMTS) {
927		/* default to first format */
928		index = 0;
929		fmt->code = ov7670_formats[0].mbus_code;
930	}
931	if (ret_fmt != NULL)
932		*ret_fmt = ov7670_formats + index;
933	/*
934	 * Fields: the OV devices claim to be progressive.
935	 */
936	fmt->field = V4L2_FIELD_NONE;
937
938	/*
939	 * Don't consider values that don't match min_height and min_width
940	 * constraints.
941	 */
942	if (info->min_width || info->min_height)
943		for (i = 0; i < n_win_sizes; i++) {
944			wsize = info->devtype->win_sizes + i;
945
946			if (wsize->width < info->min_width ||
947				wsize->height < info->min_height) {
948				win_sizes_limit = i;
949				break;
950			}
951		}
952	/*
953	 * Round requested image size down to the nearest
954	 * we support, but not below the smallest.
955	 */
956	for (wsize = info->devtype->win_sizes;
957	     wsize < info->devtype->win_sizes + win_sizes_limit; wsize++)
958		if (fmt->width >= wsize->width && fmt->height >= wsize->height)
959			break;
960	if (wsize >= info->devtype->win_sizes + win_sizes_limit)
961		wsize--;   /* Take the smallest one */
962	if (ret_wsize != NULL)
963		*ret_wsize = wsize;
964	/*
965	 * Note the size we'll actually handle.
966	 */
967	fmt->width = wsize->width;
968	fmt->height = wsize->height;
969	fmt->colorspace = ov7670_formats[index].colorspace;
970	return 0;
971}
972
973static int ov7670_try_mbus_fmt(struct v4l2_subdev *sd,
974			    struct v4l2_mbus_framefmt *fmt)
975{
976	return ov7670_try_fmt_internal(sd, fmt, NULL, NULL);
977}
978
979/*
980 * Set a format.
981 */
982static int ov7670_s_mbus_fmt(struct v4l2_subdev *sd,
983			  struct v4l2_mbus_framefmt *fmt)
984{
985	struct ov7670_format_struct *ovfmt;
986	struct ov7670_win_size *wsize;
987	struct ov7670_info *info = to_state(sd);
988	unsigned char com7;
989	int ret;
990
991	ret = ov7670_try_fmt_internal(sd, fmt, &ovfmt, &wsize);
992
993	if (ret)
994		return ret;
995	/*
996	 * COM7 is a pain in the ass, it doesn't like to be read then
997	 * quickly written afterward.  But we have everything we need
998	 * to set it absolutely here, as long as the format-specific
999	 * register sets list it first.
1000	 */
1001	com7 = ovfmt->regs[0].value;
1002	com7 |= wsize->com7_bit;
1003	ov7670_write(sd, REG_COM7, com7);
1004	/*
1005	 * Now write the rest of the array.  Also store start/stops
1006	 */
1007	ov7670_write_array(sd, ovfmt->regs + 1);
1008	ov7670_set_hw(sd, wsize->hstart, wsize->hstop, wsize->vstart,
1009			wsize->vstop);
1010	ret = 0;
1011	if (wsize->regs)
1012		ret = ov7670_write_array(sd, wsize->regs);
1013	info->fmt = ovfmt;
1014
1015	/*
1016	 * If we're running RGB565, we must rewrite clkrc after setting
1017	 * the other parameters or the image looks poor.  If we're *not*
1018	 * doing RGB565, we must not rewrite clkrc or the image looks
1019	 * *really* poor.
1020	 *
1021	 * (Update) Now that we retain clkrc state, we should be able
1022	 * to write it unconditionally, and that will make the frame
1023	 * rate persistent too.
1024	 */
1025	if (ret == 0)
1026		ret = ov7670_write(sd, REG_CLKRC, info->clkrc);
1027	return 0;
1028}
1029
1030/*
1031 * Implement G/S_PARM.  There is a "high quality" mode we could try
1032 * to do someday; for now, we just do the frame rate tweak.
1033 */
1034static int ov7670_g_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
1035{
1036	struct v4l2_captureparm *cp = &parms->parm.capture;
1037	struct ov7670_info *info = to_state(sd);
1038
1039	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1040		return -EINVAL;
1041
1042	memset(cp, 0, sizeof(struct v4l2_captureparm));
1043	cp->capability = V4L2_CAP_TIMEPERFRAME;
1044	info->devtype->get_framerate(sd, &cp->timeperframe);
1045
1046	return 0;
1047}
1048
1049static int ov7670_s_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
1050{
1051	struct v4l2_captureparm *cp = &parms->parm.capture;
1052	struct v4l2_fract *tpf = &cp->timeperframe;
1053	struct ov7670_info *info = to_state(sd);
1054
1055	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1056		return -EINVAL;
1057	if (cp->extendedmode != 0)
1058		return -EINVAL;
1059
1060	return info->devtype->set_framerate(sd, tpf);
1061}
1062
1063
1064/*
1065 * Frame intervals.  Since frame rates are controlled with the clock
1066 * divider, we can only do 30/n for integer n values.  So no continuous
1067 * or stepwise options.  Here we just pick a handful of logical values.
1068 */
1069
1070static int ov7670_frame_rates[] = { 30, 15, 10, 5, 1 };
1071
1072static int ov7670_enum_frame_interval(struct v4l2_subdev *sd,
1073				      struct v4l2_subdev_pad_config *cfg,
1074				      struct v4l2_subdev_frame_interval_enum *fie)
1075{
1076	if (fie->pad)
1077		return -EINVAL;
1078	if (fie->index >= ARRAY_SIZE(ov7670_frame_rates))
1079		return -EINVAL;
1080	fie->interval.numerator = 1;
1081	fie->interval.denominator = ov7670_frame_rates[fie->index];
1082	return 0;
1083}
1084
1085/*
1086 * Frame size enumeration
1087 */
1088static int ov7670_enum_frame_size(struct v4l2_subdev *sd,
1089				  struct v4l2_subdev_pad_config *cfg,
1090				  struct v4l2_subdev_frame_size_enum *fse)
1091{
1092	struct ov7670_info *info = to_state(sd);
1093	int i;
1094	int num_valid = -1;
1095	__u32 index = fse->index;
1096	unsigned int n_win_sizes = info->devtype->n_win_sizes;
1097
1098	if (fse->pad)
1099		return -EINVAL;
1100
1101	/*
1102	 * If a minimum width/height was requested, filter out the capture
1103	 * windows that fall outside that.
1104	 */
1105	for (i = 0; i < n_win_sizes; i++) {
1106		struct ov7670_win_size *win = &info->devtype->win_sizes[i];
1107		if (info->min_width && win->width < info->min_width)
1108			continue;
1109		if (info->min_height && win->height < info->min_height)
1110			continue;
1111		if (index == ++num_valid) {
1112			fse->min_width = fse->max_width = win->width;
1113			fse->min_height = fse->max_height = win->height;
1114			return 0;
1115		}
1116	}
1117
1118	return -EINVAL;
1119}
1120
1121/*
1122 * Code for dealing with controls.
1123 */
1124
1125static int ov7670_store_cmatrix(struct v4l2_subdev *sd,
1126		int matrix[CMATRIX_LEN])
1127{
1128	int i, ret;
1129	unsigned char signbits = 0;
1130
1131	/*
1132	 * Weird crap seems to exist in the upper part of
1133	 * the sign bits register, so let's preserve it.
1134	 */
1135	ret = ov7670_read(sd, REG_CMATRIX_SIGN, &signbits);
1136	signbits &= 0xc0;
1137
1138	for (i = 0; i < CMATRIX_LEN; i++) {
1139		unsigned char raw;
1140
1141		if (matrix[i] < 0) {
1142			signbits |= (1 << i);
1143			if (matrix[i] < -255)
1144				raw = 0xff;
1145			else
1146				raw = (-1 * matrix[i]) & 0xff;
1147		}
1148		else {
1149			if (matrix[i] > 255)
1150				raw = 0xff;
1151			else
1152				raw = matrix[i] & 0xff;
1153		}
1154		ret += ov7670_write(sd, REG_CMATRIX_BASE + i, raw);
1155	}
1156	ret += ov7670_write(sd, REG_CMATRIX_SIGN, signbits);
1157	return ret;
1158}
1159
1160
1161/*
1162 * Hue also requires messing with the color matrix.  It also requires
1163 * trig functions, which tend not to be well supported in the kernel.
1164 * So here is a simple table of sine values, 0-90 degrees, in steps
1165 * of five degrees.  Values are multiplied by 1000.
1166 *
1167 * The following naive approximate trig functions require an argument
1168 * carefully limited to -180 <= theta <= 180.
1169 */
1170#define SIN_STEP 5
1171static const int ov7670_sin_table[] = {
1172	   0,	 87,   173,   258,   342,   422,
1173	 499,	573,   642,   707,   766,   819,
1174	 866,	906,   939,   965,   984,   996,
1175	1000
1176};
1177
1178static int ov7670_sine(int theta)
1179{
1180	int chs = 1;
1181	int sine;
1182
1183	if (theta < 0) {
1184		theta = -theta;
1185		chs = -1;
1186	}
1187	if (theta <= 90)
1188		sine = ov7670_sin_table[theta/SIN_STEP];
1189	else {
1190		theta -= 90;
1191		sine = 1000 - ov7670_sin_table[theta/SIN_STEP];
1192	}
1193	return sine*chs;
1194}
1195
1196static int ov7670_cosine(int theta)
1197{
1198	theta = 90 - theta;
1199	if (theta > 180)
1200		theta -= 360;
1201	else if (theta < -180)
1202		theta += 360;
1203	return ov7670_sine(theta);
1204}
1205
1206
1207
1208
1209static void ov7670_calc_cmatrix(struct ov7670_info *info,
1210		int matrix[CMATRIX_LEN], int sat, int hue)
1211{
1212	int i;
1213	/*
1214	 * Apply the current saturation setting first.
1215	 */
1216	for (i = 0; i < CMATRIX_LEN; i++)
1217		matrix[i] = (info->fmt->cmatrix[i] * sat) >> 7;
1218	/*
1219	 * Then, if need be, rotate the hue value.
1220	 */
1221	if (hue != 0) {
1222		int sinth, costh, tmpmatrix[CMATRIX_LEN];
1223
1224		memcpy(tmpmatrix, matrix, CMATRIX_LEN*sizeof(int));
1225		sinth = ov7670_sine(hue);
1226		costh = ov7670_cosine(hue);
1227
1228		matrix[0] = (matrix[3]*sinth + matrix[0]*costh)/1000;
1229		matrix[1] = (matrix[4]*sinth + matrix[1]*costh)/1000;
1230		matrix[2] = (matrix[5]*sinth + matrix[2]*costh)/1000;
1231		matrix[3] = (matrix[3]*costh - matrix[0]*sinth)/1000;
1232		matrix[4] = (matrix[4]*costh - matrix[1]*sinth)/1000;
1233		matrix[5] = (matrix[5]*costh - matrix[2]*sinth)/1000;
1234	}
1235}
1236
1237
1238
1239static int ov7670_s_sat_hue(struct v4l2_subdev *sd, int sat, int hue)
1240{
1241	struct ov7670_info *info = to_state(sd);
1242	int matrix[CMATRIX_LEN];
1243	int ret;
1244
1245	ov7670_calc_cmatrix(info, matrix, sat, hue);
1246	ret = ov7670_store_cmatrix(sd, matrix);
1247	return ret;
1248}
1249
1250
1251/*
1252 * Some weird registers seem to store values in a sign/magnitude format!
1253 */
1254
1255static unsigned char ov7670_abs_to_sm(unsigned char v)
1256{
1257	if (v > 127)
1258		return v & 0x7f;
1259	return (128 - v) | 0x80;
1260}
1261
1262static int ov7670_s_brightness(struct v4l2_subdev *sd, int value)
1263{
1264	unsigned char com8 = 0, v;
1265	int ret;
1266
1267	ov7670_read(sd, REG_COM8, &com8);
1268	com8 &= ~COM8_AEC;
1269	ov7670_write(sd, REG_COM8, com8);
1270	v = ov7670_abs_to_sm(value);
1271	ret = ov7670_write(sd, REG_BRIGHT, v);
1272	return ret;
1273}
1274
1275static int ov7670_s_contrast(struct v4l2_subdev *sd, int value)
1276{
1277	return ov7670_write(sd, REG_CONTRAS, (unsigned char) value);
1278}
1279
1280static int ov7670_s_hflip(struct v4l2_subdev *sd, int value)
1281{
1282	unsigned char v = 0;
1283	int ret;
1284
1285	ret = ov7670_read(sd, REG_MVFP, &v);
1286	if (value)
1287		v |= MVFP_MIRROR;
1288	else
1289		v &= ~MVFP_MIRROR;
1290	msleep(10);  /* FIXME */
1291	ret += ov7670_write(sd, REG_MVFP, v);
1292	return ret;
1293}
1294
1295static int ov7670_s_vflip(struct v4l2_subdev *sd, int value)
1296{
1297	unsigned char v = 0;
1298	int ret;
1299
1300	ret = ov7670_read(sd, REG_MVFP, &v);
1301	if (value)
1302		v |= MVFP_FLIP;
1303	else
1304		v &= ~MVFP_FLIP;
1305	msleep(10);  /* FIXME */
1306	ret += ov7670_write(sd, REG_MVFP, v);
1307	return ret;
1308}
1309
1310/*
1311 * GAIN is split between REG_GAIN and REG_VREF[7:6].  If one believes
1312 * the data sheet, the VREF parts should be the most significant, but
1313 * experience shows otherwise.  There seems to be little value in
1314 * messing with the VREF bits, so we leave them alone.
1315 */
1316static int ov7670_g_gain(struct v4l2_subdev *sd, __s32 *value)
1317{
1318	int ret;
1319	unsigned char gain;
1320
1321	ret = ov7670_read(sd, REG_GAIN, &gain);
1322	*value = gain;
1323	return ret;
1324}
1325
1326static int ov7670_s_gain(struct v4l2_subdev *sd, int value)
1327{
1328	int ret;
1329	unsigned char com8;
1330
1331	ret = ov7670_write(sd, REG_GAIN, value & 0xff);
1332	/* Have to turn off AGC as well */
1333	if (ret == 0) {
1334		ret = ov7670_read(sd, REG_COM8, &com8);
1335		ret = ov7670_write(sd, REG_COM8, com8 & ~COM8_AGC);
1336	}
1337	return ret;
1338}
1339
1340/*
1341 * Tweak autogain.
1342 */
1343static int ov7670_s_autogain(struct v4l2_subdev *sd, int value)
1344{
1345	int ret;
1346	unsigned char com8;
1347
1348	ret = ov7670_read(sd, REG_COM8, &com8);
1349	if (ret == 0) {
1350		if (value)
1351			com8 |= COM8_AGC;
1352		else
1353			com8 &= ~COM8_AGC;
1354		ret = ov7670_write(sd, REG_COM8, com8);
1355	}
1356	return ret;
1357}
1358
1359static int ov7670_s_exp(struct v4l2_subdev *sd, int value)
1360{
1361	int ret;
1362	unsigned char com1, com8, aech, aechh;
1363
1364	ret = ov7670_read(sd, REG_COM1, &com1) +
1365		ov7670_read(sd, REG_COM8, &com8);
1366		ov7670_read(sd, REG_AECHH, &aechh);
1367	if (ret)
1368		return ret;
1369
1370	com1 = (com1 & 0xfc) | (value & 0x03);
1371	aech = (value >> 2) & 0xff;
1372	aechh = (aechh & 0xc0) | ((value >> 10) & 0x3f);
1373	ret = ov7670_write(sd, REG_COM1, com1) +
1374		ov7670_write(sd, REG_AECH, aech) +
1375		ov7670_write(sd, REG_AECHH, aechh);
1376	/* Have to turn off AEC as well */
1377	if (ret == 0)
1378		ret = ov7670_write(sd, REG_COM8, com8 & ~COM8_AEC);
1379	return ret;
1380}
1381
1382/*
1383 * Tweak autoexposure.
1384 */
1385static int ov7670_s_autoexp(struct v4l2_subdev *sd,
1386		enum v4l2_exposure_auto_type value)
1387{
1388	int ret;
1389	unsigned char com8;
1390
1391	ret = ov7670_read(sd, REG_COM8, &com8);
1392	if (ret == 0) {
1393		if (value == V4L2_EXPOSURE_AUTO)
1394			com8 |= COM8_AEC;
1395		else
1396			com8 &= ~COM8_AEC;
1397		ret = ov7670_write(sd, REG_COM8, com8);
1398	}
1399	return ret;
1400}
1401
1402
1403static int ov7670_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
1404{
1405	struct v4l2_subdev *sd = to_sd(ctrl);
1406	struct ov7670_info *info = to_state(sd);
1407
1408	switch (ctrl->id) {
1409	case V4L2_CID_AUTOGAIN:
1410		return ov7670_g_gain(sd, &info->gain->val);
1411	}
1412	return -EINVAL;
1413}
1414
1415static int ov7670_s_ctrl(struct v4l2_ctrl *ctrl)
1416{
1417	struct v4l2_subdev *sd = to_sd(ctrl);
1418	struct ov7670_info *info = to_state(sd);
1419
1420	switch (ctrl->id) {
1421	case V4L2_CID_BRIGHTNESS:
1422		return ov7670_s_brightness(sd, ctrl->val);
1423	case V4L2_CID_CONTRAST:
1424		return ov7670_s_contrast(sd, ctrl->val);
1425	case V4L2_CID_SATURATION:
1426		return ov7670_s_sat_hue(sd,
1427				info->saturation->val, info->hue->val);
1428	case V4L2_CID_VFLIP:
1429		return ov7670_s_vflip(sd, ctrl->val);
1430	case V4L2_CID_HFLIP:
1431		return ov7670_s_hflip(sd, ctrl->val);
1432	case V4L2_CID_AUTOGAIN:
1433		/* Only set manual gain if auto gain is not explicitly
1434		   turned on. */
1435		if (!ctrl->val) {
1436			/* ov7670_s_gain turns off auto gain */
1437			return ov7670_s_gain(sd, info->gain->val);
1438		}
1439		return ov7670_s_autogain(sd, ctrl->val);
1440	case V4L2_CID_EXPOSURE_AUTO:
1441		/* Only set manual exposure if auto exposure is not explicitly
1442		   turned on. */
1443		if (ctrl->val == V4L2_EXPOSURE_MANUAL) {
1444			/* ov7670_s_exp turns off auto exposure */
1445			return ov7670_s_exp(sd, info->exposure->val);
1446		}
1447		return ov7670_s_autoexp(sd, ctrl->val);
1448	}
1449	return -EINVAL;
1450}
1451
1452static const struct v4l2_ctrl_ops ov7670_ctrl_ops = {
1453	.s_ctrl = ov7670_s_ctrl,
1454	.g_volatile_ctrl = ov7670_g_volatile_ctrl,
1455};
1456
1457#ifdef CONFIG_VIDEO_ADV_DEBUG
1458static int ov7670_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
1459{
1460	unsigned char val = 0;
1461	int ret;
1462
1463	ret = ov7670_read(sd, reg->reg & 0xff, &val);
1464	reg->val = val;
1465	reg->size = 1;
1466	return ret;
1467}
1468
1469static int ov7670_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
1470{
1471	ov7670_write(sd, reg->reg & 0xff, reg->val & 0xff);
1472	return 0;
1473}
1474#endif
1475
1476/* ----------------------------------------------------------------------- */
1477
1478static const struct v4l2_subdev_core_ops ov7670_core_ops = {
1479	.reset = ov7670_reset,
1480	.init = ov7670_init,
1481#ifdef CONFIG_VIDEO_ADV_DEBUG
1482	.g_register = ov7670_g_register,
1483	.s_register = ov7670_s_register,
1484#endif
1485};
1486
1487static const struct v4l2_subdev_video_ops ov7670_video_ops = {
1488	.enum_mbus_fmt = ov7670_enum_mbus_fmt,
1489	.try_mbus_fmt = ov7670_try_mbus_fmt,
1490	.s_mbus_fmt = ov7670_s_mbus_fmt,
1491	.s_parm = ov7670_s_parm,
1492	.g_parm = ov7670_g_parm,
1493};
1494
1495static const struct v4l2_subdev_pad_ops ov7670_pad_ops = {
1496	.enum_frame_interval = ov7670_enum_frame_interval,
1497	.enum_frame_size = ov7670_enum_frame_size,
1498};
1499
1500static const struct v4l2_subdev_ops ov7670_ops = {
1501	.core = &ov7670_core_ops,
1502	.video = &ov7670_video_ops,
1503	.pad = &ov7670_pad_ops,
1504};
1505
1506/* ----------------------------------------------------------------------- */
1507
1508static const struct ov7670_devtype ov7670_devdata[] = {
1509	[MODEL_OV7670] = {
1510		.win_sizes = ov7670_win_sizes,
1511		.n_win_sizes = ARRAY_SIZE(ov7670_win_sizes),
1512		.set_framerate = ov7670_set_framerate_legacy,
1513		.get_framerate = ov7670_get_framerate_legacy,
1514	},
1515	[MODEL_OV7675] = {
1516		.win_sizes = ov7675_win_sizes,
1517		.n_win_sizes = ARRAY_SIZE(ov7675_win_sizes),
1518		.set_framerate = ov7675_set_framerate,
1519		.get_framerate = ov7675_get_framerate,
1520	},
1521};
1522
1523static int ov7670_probe(struct i2c_client *client,
1524			const struct i2c_device_id *id)
1525{
1526	struct v4l2_fract tpf;
1527	struct v4l2_subdev *sd;
1528	struct ov7670_info *info;
1529	int ret;
1530
1531	info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
1532	if (info == NULL)
1533		return -ENOMEM;
1534	sd = &info->sd;
1535	v4l2_i2c_subdev_init(sd, client, &ov7670_ops);
1536
1537	info->clock_speed = 30; /* default: a guess */
1538	if (client->dev.platform_data) {
1539		struct ov7670_config *config = client->dev.platform_data;
1540
1541		/*
1542		 * Must apply configuration before initializing device, because it
1543		 * selects I/O method.
1544		 */
1545		info->min_width = config->min_width;
1546		info->min_height = config->min_height;
1547		info->use_smbus = config->use_smbus;
1548
1549		if (config->clock_speed)
1550			info->clock_speed = config->clock_speed;
1551
1552		/*
1553		 * It should be allowed for ov7670 too when it is migrated to
1554		 * the new frame rate formula.
1555		 */
1556		if (config->pll_bypass && id->driver_data != MODEL_OV7670)
1557			info->pll_bypass = true;
1558
1559		if (config->pclk_hb_disable)
1560			info->pclk_hb_disable = true;
1561	}
1562
1563	/* Make sure it's an ov7670 */
1564	ret = ov7670_detect(sd);
1565	if (ret) {
1566		v4l_dbg(1, debug, client,
1567			"chip found @ 0x%x (%s) is not an ov7670 chip.\n",
1568			client->addr << 1, client->adapter->name);
1569		return ret;
1570	}
1571	v4l_info(client, "chip found @ 0x%02x (%s)\n",
1572			client->addr << 1, client->adapter->name);
1573
1574	info->devtype = &ov7670_devdata[id->driver_data];
1575	info->fmt = &ov7670_formats[0];
1576	info->clkrc = 0;
1577
1578	/* Set default frame rate to 30 fps */
1579	tpf.numerator = 1;
1580	tpf.denominator = 30;
1581	info->devtype->set_framerate(sd, &tpf);
1582
1583	if (info->pclk_hb_disable)
1584		ov7670_write(sd, REG_COM10, COM10_PCLK_HB);
1585
1586	v4l2_ctrl_handler_init(&info->hdl, 10);
1587	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1588			V4L2_CID_BRIGHTNESS, 0, 255, 1, 128);
1589	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1590			V4L2_CID_CONTRAST, 0, 127, 1, 64);
1591	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1592			V4L2_CID_VFLIP, 0, 1, 1, 0);
1593	v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1594			V4L2_CID_HFLIP, 0, 1, 1, 0);
1595	info->saturation = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1596			V4L2_CID_SATURATION, 0, 256, 1, 128);
1597	info->hue = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1598			V4L2_CID_HUE, -180, 180, 5, 0);
1599	info->gain = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1600			V4L2_CID_GAIN, 0, 255, 1, 128);
1601	info->auto_gain = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1602			V4L2_CID_AUTOGAIN, 0, 1, 1, 1);
1603	info->exposure = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
1604			V4L2_CID_EXPOSURE, 0, 65535, 1, 500);
1605	info->auto_exposure = v4l2_ctrl_new_std_menu(&info->hdl, &ov7670_ctrl_ops,
1606			V4L2_CID_EXPOSURE_AUTO, V4L2_EXPOSURE_MANUAL, 0,
1607			V4L2_EXPOSURE_AUTO);
1608	sd->ctrl_handler = &info->hdl;
1609	if (info->hdl.error) {
1610		int err = info->hdl.error;
1611
1612		v4l2_ctrl_handler_free(&info->hdl);
1613		return err;
1614	}
1615	/*
1616	 * We have checked empirically that hw allows to read back the gain
1617	 * value chosen by auto gain but that's not the case for auto exposure.
1618	 */
1619	v4l2_ctrl_auto_cluster(2, &info->auto_gain, 0, true);
1620	v4l2_ctrl_auto_cluster(2, &info->auto_exposure,
1621			       V4L2_EXPOSURE_MANUAL, false);
1622	v4l2_ctrl_cluster(2, &info->saturation);
1623	v4l2_ctrl_handler_setup(&info->hdl);
1624
1625	return 0;
1626}
1627
1628
1629static int ov7670_remove(struct i2c_client *client)
1630{
1631	struct v4l2_subdev *sd = i2c_get_clientdata(client);
1632	struct ov7670_info *info = to_state(sd);
1633
1634	v4l2_device_unregister_subdev(sd);
1635	v4l2_ctrl_handler_free(&info->hdl);
1636	return 0;
1637}
1638
1639static const struct i2c_device_id ov7670_id[] = {
1640	{ "ov7670", MODEL_OV7670 },
1641	{ "ov7675", MODEL_OV7675 },
1642	{ }
1643};
1644MODULE_DEVICE_TABLE(i2c, ov7670_id);
1645
1646static struct i2c_driver ov7670_driver = {
1647	.driver = {
1648		.owner	= THIS_MODULE,
1649		.name	= "ov7670",
1650	},
1651	.probe		= ov7670_probe,
1652	.remove		= ov7670_remove,
1653	.id_table	= ov7670_id,
1654};
1655
1656module_i2c_driver(ov7670_driver);
1657