V4L/DVB (11910): mt9: Use v4l bounding/alignment function
[linux-2.6.git] / drivers / media / video / mt9t031.c
1 /*
2  * Driver for MT9T031 CMOS Image Sensor from Micron
3  *
4  * Copyright (C) 2008, Guennadi Liakhovetski, DENX Software Engineering <lg@denx.de>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10
11 #include <linux/videodev2.h>
12 #include <linux/slab.h>
13 #include <linux/i2c.h>
14 #include <linux/log2.h>
15
16 #include <media/v4l2-common.h>
17 #include <media/v4l2-chip-ident.h>
18 #include <media/soc_camera.h>
19
20 /* mt9t031 i2c address 0x5d
21  * The platform has to define i2c_board_info
22  * and call i2c_register_board_info() */
23
24 /* mt9t031 selected register addresses */
25 #define MT9T031_CHIP_VERSION            0x00
26 #define MT9T031_ROW_START               0x01
27 #define MT9T031_COLUMN_START            0x02
28 #define MT9T031_WINDOW_HEIGHT           0x03
29 #define MT9T031_WINDOW_WIDTH            0x04
30 #define MT9T031_HORIZONTAL_BLANKING     0x05
31 #define MT9T031_VERTICAL_BLANKING       0x06
32 #define MT9T031_OUTPUT_CONTROL          0x07
33 #define MT9T031_SHUTTER_WIDTH_UPPER     0x08
34 #define MT9T031_SHUTTER_WIDTH           0x09
35 #define MT9T031_PIXEL_CLOCK_CONTROL     0x0a
36 #define MT9T031_FRAME_RESTART           0x0b
37 #define MT9T031_SHUTTER_DELAY           0x0c
38 #define MT9T031_RESET                   0x0d
39 #define MT9T031_READ_MODE_1             0x1e
40 #define MT9T031_READ_MODE_2             0x20
41 #define MT9T031_READ_MODE_3             0x21
42 #define MT9T031_ROW_ADDRESS_MODE        0x22
43 #define MT9T031_COLUMN_ADDRESS_MODE     0x23
44 #define MT9T031_GLOBAL_GAIN             0x35
45 #define MT9T031_CHIP_ENABLE             0xF8
46
47 #define MT9T031_MAX_HEIGHT              1536
48 #define MT9T031_MAX_WIDTH               2048
49 #define MT9T031_MIN_HEIGHT              2
50 #define MT9T031_MIN_WIDTH               2
51 #define MT9T031_HORIZONTAL_BLANK        142
52 #define MT9T031_VERTICAL_BLANK          25
53 #define MT9T031_COLUMN_SKIP             32
54 #define MT9T031_ROW_SKIP                20
55
56 #define MT9T031_BUS_PARAM       (SOCAM_PCLK_SAMPLE_RISING |     \
57         SOCAM_PCLK_SAMPLE_FALLING | SOCAM_HSYNC_ACTIVE_HIGH |   \
58         SOCAM_VSYNC_ACTIVE_HIGH | SOCAM_DATA_ACTIVE_HIGH |      \
59         SOCAM_MASTER | SOCAM_DATAWIDTH_10)
60
61 static const struct soc_camera_data_format mt9t031_colour_formats[] = {
62         {
63                 .name           = "Bayer (sRGB) 10 bit",
64                 .depth          = 10,
65                 .fourcc         = V4L2_PIX_FMT_SGRBG10,
66                 .colorspace     = V4L2_COLORSPACE_SRGB,
67         }
68 };
69
70 struct mt9t031 {
71         struct i2c_client *client;
72         struct soc_camera_device icd;
73         int model;      /* V4L2_IDENT_MT9T031* codes from v4l2-chip-ident.h */
74         unsigned char autoexposure;
75         u16 xskip;
76         u16 yskip;
77 };
78
79 static int reg_read(struct i2c_client *client, const u8 reg)
80 {
81         s32 data = i2c_smbus_read_word_data(client, reg);
82         return data < 0 ? data : swab16(data);
83 }
84
85 static int reg_write(struct i2c_client *client, const u8 reg,
86                      const u16 data)
87 {
88         return i2c_smbus_write_word_data(client, reg, swab16(data));
89 }
90
91 static int reg_set(struct i2c_client *client, const u8 reg,
92                    const u16 data)
93 {
94         int ret;
95
96         ret = reg_read(client, reg);
97         if (ret < 0)
98                 return ret;
99         return reg_write(client, reg, ret | data);
100 }
101
102 static int reg_clear(struct i2c_client *client, const u8 reg,
103                      const u16 data)
104 {
105         int ret;
106
107         ret = reg_read(client, reg);
108         if (ret < 0)
109                 return ret;
110         return reg_write(client, reg, ret & ~data);
111 }
112
113 static int set_shutter(struct i2c_client *client, const u32 data)
114 {
115         int ret;
116
117         ret = reg_write(client, MT9T031_SHUTTER_WIDTH_UPPER, data >> 16);
118
119         if (ret >= 0)
120                 ret = reg_write(client, MT9T031_SHUTTER_WIDTH, data & 0xffff);
121
122         return ret;
123 }
124
125 static int get_shutter(struct i2c_client *client, u32 *data)
126 {
127         int ret;
128
129         ret = reg_read(client, MT9T031_SHUTTER_WIDTH_UPPER);
130         *data = ret << 16;
131
132         if (ret >= 0)
133                 ret = reg_read(client, MT9T031_SHUTTER_WIDTH);
134         *data |= ret & 0xffff;
135
136         return ret < 0 ? ret : 0;
137 }
138
139 static int mt9t031_init(struct soc_camera_device *icd)
140 {
141         struct i2c_client *client = to_i2c_client(icd->control);
142         struct soc_camera_link *icl = client->dev.platform_data;
143         int ret;
144
145         if (icl->power) {
146                 ret = icl->power(&client->dev, 1);
147                 if (ret < 0) {
148                         dev_err(icd->vdev->parent,
149                                 "Platform failed to power-on the camera.\n");
150                         return ret;
151                 }
152         }
153
154         /* Disable chip output, synchronous option update */
155         ret = reg_write(client, MT9T031_RESET, 1);
156         if (ret >= 0)
157                 ret = reg_write(client, MT9T031_RESET, 0);
158         if (ret >= 0)
159                 ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
160
161         if (ret < 0 && icl->power)
162                 icl->power(&client->dev, 0);
163
164         return ret >= 0 ? 0 : -EIO;
165 }
166
167 static int mt9t031_release(struct soc_camera_device *icd)
168 {
169         struct i2c_client *client = to_i2c_client(icd->control);
170         struct soc_camera_link *icl = client->dev.platform_data;
171
172         /* Disable the chip */
173         reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
174
175         if (icl->power)
176                 icl->power(&client->dev, 0);
177
178         return 0;
179 }
180
181 static int mt9t031_start_capture(struct soc_camera_device *icd)
182 {
183         struct i2c_client *client = to_i2c_client(icd->control);
184
185         /* Switch to master "normal" mode */
186         if (reg_set(client, MT9T031_OUTPUT_CONTROL, 2) < 0)
187                 return -EIO;
188         return 0;
189 }
190
191 static int mt9t031_stop_capture(struct soc_camera_device *icd)
192 {
193         struct i2c_client *client = to_i2c_client(icd->control);
194
195         /* Stop sensor readout */
196         if (reg_clear(client, MT9T031_OUTPUT_CONTROL, 2) < 0)
197                 return -EIO;
198         return 0;
199 }
200
201 static int mt9t031_set_bus_param(struct soc_camera_device *icd,
202                                  unsigned long flags)
203 {
204         struct i2c_client *client = to_i2c_client(icd->control);
205
206         /* The caller should have queried our parameters, check anyway */
207         if (flags & ~MT9T031_BUS_PARAM)
208                 return -EINVAL;
209
210         if (flags & SOCAM_PCLK_SAMPLE_FALLING)
211                 reg_clear(client, MT9T031_PIXEL_CLOCK_CONTROL, 0x8000);
212         else
213                 reg_set(client, MT9T031_PIXEL_CLOCK_CONTROL, 0x8000);
214
215         return 0;
216 }
217
218 static unsigned long mt9t031_query_bus_param(struct soc_camera_device *icd)
219 {
220         struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
221         struct soc_camera_link *icl = mt9t031->client->dev.platform_data;
222
223         return soc_camera_apply_sensor_flags(icl, MT9T031_BUS_PARAM);
224 }
225
226 /* Round up minima and round down maxima */
227 static void recalculate_limits(struct soc_camera_device *icd,
228                                u16 xskip, u16 yskip)
229 {
230         icd->x_min = (MT9T031_COLUMN_SKIP + xskip - 1) / xskip;
231         icd->y_min = (MT9T031_ROW_SKIP + yskip - 1) / yskip;
232         icd->width_min = (MT9T031_MIN_WIDTH + xskip - 1) / xskip;
233         icd->height_min = (MT9T031_MIN_HEIGHT + yskip - 1) / yskip;
234         icd->width_max = MT9T031_MAX_WIDTH / xskip;
235         icd->height_max = MT9T031_MAX_HEIGHT / yskip;
236 }
237
238 static int mt9t031_set_params(struct soc_camera_device *icd,
239                               struct v4l2_rect *rect, u16 xskip, u16 yskip)
240 {
241         struct i2c_client *client = to_i2c_client(icd->control);
242         struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
243         int ret;
244         u16 xbin, ybin, width, height, left, top;
245         const u16 hblank = MT9T031_HORIZONTAL_BLANK,
246                 vblank = MT9T031_VERTICAL_BLANK;
247
248         /* Make sure we don't exceed sensor limits */
249         if (rect->left + rect->width > icd->width_max)
250                 rect->left = (icd->width_max - rect->width) / 2 + icd->x_min;
251
252         if (rect->top + rect->height > icd->height_max)
253                 rect->top = (icd->height_max - rect->height) / 2 + icd->y_min;
254
255         width = rect->width * xskip;
256         height = rect->height * yskip;
257         left = rect->left * xskip;
258         top = rect->top * yskip;
259
260         xbin = min(xskip, (u16)3);
261         ybin = min(yskip, (u16)3);
262
263         dev_dbg(&icd->dev, "xskip %u, width %u/%u, yskip %u, height %u/%u\n",
264                 xskip, width, rect->width, yskip, height, rect->height);
265
266         /* Could just do roundup(rect->left, [xy]bin * 2); but this is cheaper */
267         switch (xbin) {
268         case 2:
269                 left = (left + 3) & ~3;
270                 break;
271         case 3:
272                 left = roundup(left, 6);
273         }
274
275         switch (ybin) {
276         case 2:
277                 top = (top + 3) & ~3;
278                 break;
279         case 3:
280                 top = roundup(top, 6);
281         }
282
283         /* Disable register update, reconfigure atomically */
284         ret = reg_set(client, MT9T031_OUTPUT_CONTROL, 1);
285         if (ret < 0)
286                 return ret;
287
288         /* Blanking and start values - default... */
289         ret = reg_write(client, MT9T031_HORIZONTAL_BLANKING, hblank);
290         if (ret >= 0)
291                 ret = reg_write(client, MT9T031_VERTICAL_BLANKING, vblank);
292
293         if (yskip != mt9t031->yskip || xskip != mt9t031->xskip) {
294                 /* Binning, skipping */
295                 if (ret >= 0)
296                         ret = reg_write(client, MT9T031_COLUMN_ADDRESS_MODE,
297                                         ((xbin - 1) << 4) | (xskip - 1));
298                 if (ret >= 0)
299                         ret = reg_write(client, MT9T031_ROW_ADDRESS_MODE,
300                                         ((ybin - 1) << 4) | (yskip - 1));
301         }
302         dev_dbg(&icd->dev, "new physical left %u, top %u\n", left, top);
303
304         /* The caller provides a supported format, as guaranteed by
305          * icd->try_fmt_cap(), soc_camera_s_crop() and soc_camera_cropcap() */
306         if (ret >= 0)
307                 ret = reg_write(client, MT9T031_COLUMN_START, left);
308         if (ret >= 0)
309                 ret = reg_write(client, MT9T031_ROW_START, top);
310         if (ret >= 0)
311                 ret = reg_write(client, MT9T031_WINDOW_WIDTH, width - 1);
312         if (ret >= 0)
313                 ret = reg_write(client, MT9T031_WINDOW_HEIGHT,
314                                 height + icd->y_skip_top - 1);
315         if (ret >= 0 && mt9t031->autoexposure) {
316                 ret = set_shutter(client, height + icd->y_skip_top + vblank);
317                 if (ret >= 0) {
318                         const u32 shutter_max = MT9T031_MAX_HEIGHT + vblank;
319                         const struct v4l2_queryctrl *qctrl =
320                                 soc_camera_find_qctrl(icd->ops,
321                                                       V4L2_CID_EXPOSURE);
322                         icd->exposure = (shutter_max / 2 + (height +
323                                          icd->y_skip_top + vblank - 1) *
324                                          (qctrl->maximum - qctrl->minimum)) /
325                                 shutter_max + qctrl->minimum;
326                 }
327         }
328
329         /* Re-enable register update, commit all changes */
330         if (ret >= 0)
331                 ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 1);
332
333         return ret < 0 ? ret : 0;
334 }
335
336 static int mt9t031_set_crop(struct soc_camera_device *icd,
337                             struct v4l2_rect *rect)
338 {
339         struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
340
341         /* CROP - no change in scaling, or in limits */
342         return mt9t031_set_params(icd, rect, mt9t031->xskip, mt9t031->yskip);
343 }
344
345 static int mt9t031_set_fmt(struct soc_camera_device *icd,
346                            struct v4l2_format *f)
347 {
348         struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
349         int ret;
350         u16 xskip, yskip;
351         struct v4l2_rect rect = {
352                 .left   = icd->x_current,
353                 .top    = icd->y_current,
354                 .width  = f->fmt.pix.width,
355                 .height = f->fmt.pix.height,
356         };
357
358         /*
359          * try_fmt has put rectangle within limits.
360          * S_FMT - use binning and skipping for scaling, recalculate
361          * limits, used for cropping
362          */
363         /* Is this more optimal than just a division? */
364         for (xskip = 8; xskip > 1; xskip--)
365                 if (rect.width * xskip <= MT9T031_MAX_WIDTH)
366                         break;
367
368         for (yskip = 8; yskip > 1; yskip--)
369                 if (rect.height * yskip <= MT9T031_MAX_HEIGHT)
370                         break;
371
372         recalculate_limits(icd, xskip, yskip);
373
374         ret = mt9t031_set_params(icd, &rect, xskip, yskip);
375         if (!ret) {
376                 mt9t031->xskip = xskip;
377                 mt9t031->yskip = yskip;
378         }
379
380         return ret;
381 }
382
383 static int mt9t031_try_fmt(struct soc_camera_device *icd,
384                            struct v4l2_format *f)
385 {
386         struct v4l2_pix_format *pix = &f->fmt.pix;
387
388         v4l_bound_align_image(
389                 &pix->width, MT9T031_MIN_WIDTH, MT9T031_MAX_WIDTH, 1,
390                 &pix->height, MT9T031_MIN_HEIGHT, MT9T031_MAX_HEIGHT, 1, 0);
391
392         return 0;
393 }
394
395 static int mt9t031_get_chip_id(struct soc_camera_device *icd,
396                                struct v4l2_dbg_chip_ident *id)
397 {
398         struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
399
400         if (id->match.type != V4L2_CHIP_MATCH_I2C_ADDR)
401                 return -EINVAL;
402
403         if (id->match.addr != mt9t031->client->addr)
404                 return -ENODEV;
405
406         id->ident       = mt9t031->model;
407         id->revision    = 0;
408
409         return 0;
410 }
411
412 #ifdef CONFIG_VIDEO_ADV_DEBUG
413 static int mt9t031_get_register(struct soc_camera_device *icd,
414                                 struct v4l2_dbg_register *reg)
415 {
416         struct i2c_client *client = to_i2c_client(icd->control);
417
418         if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
419                 return -EINVAL;
420
421         if (reg->match.addr != client->addr)
422                 return -ENODEV;
423
424         reg->val = reg_read(client, reg->reg);
425
426         if (reg->val > 0xffff)
427                 return -EIO;
428
429         return 0;
430 }
431
432 static int mt9t031_set_register(struct soc_camera_device *icd,
433                                 struct v4l2_dbg_register *reg)
434 {
435         struct i2c_client *client = to_i2c_client(icd->control);
436
437         if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
438                 return -EINVAL;
439
440         if (reg->match.addr != client->addr)
441                 return -ENODEV;
442
443         if (reg_write(client, reg->reg, reg->val) < 0)
444                 return -EIO;
445
446         return 0;
447 }
448 #endif
449
450 static const struct v4l2_queryctrl mt9t031_controls[] = {
451         {
452                 .id             = V4L2_CID_VFLIP,
453                 .type           = V4L2_CTRL_TYPE_BOOLEAN,
454                 .name           = "Flip Vertically",
455                 .minimum        = 0,
456                 .maximum        = 1,
457                 .step           = 1,
458                 .default_value  = 0,
459         }, {
460                 .id             = V4L2_CID_HFLIP,
461                 .type           = V4L2_CTRL_TYPE_BOOLEAN,
462                 .name           = "Flip Horizontally",
463                 .minimum        = 0,
464                 .maximum        = 1,
465                 .step           = 1,
466                 .default_value  = 0,
467         }, {
468                 .id             = V4L2_CID_GAIN,
469                 .type           = V4L2_CTRL_TYPE_INTEGER,
470                 .name           = "Gain",
471                 .minimum        = 0,
472                 .maximum        = 127,
473                 .step           = 1,
474                 .default_value  = 64,
475                 .flags          = V4L2_CTRL_FLAG_SLIDER,
476         }, {
477                 .id             = V4L2_CID_EXPOSURE,
478                 .type           = V4L2_CTRL_TYPE_INTEGER,
479                 .name           = "Exposure",
480                 .minimum        = 1,
481                 .maximum        = 255,
482                 .step           = 1,
483                 .default_value  = 255,
484                 .flags          = V4L2_CTRL_FLAG_SLIDER,
485         }, {
486                 .id             = V4L2_CID_EXPOSURE_AUTO,
487                 .type           = V4L2_CTRL_TYPE_BOOLEAN,
488                 .name           = "Automatic Exposure",
489                 .minimum        = 0,
490                 .maximum        = 1,
491                 .step           = 1,
492                 .default_value  = 1,
493         }
494 };
495
496 static int mt9t031_video_probe(struct soc_camera_device *);
497 static void mt9t031_video_remove(struct soc_camera_device *);
498 static int mt9t031_get_control(struct soc_camera_device *, struct v4l2_control *);
499 static int mt9t031_set_control(struct soc_camera_device *, struct v4l2_control *);
500
501 static struct soc_camera_ops mt9t031_ops = {
502         .owner                  = THIS_MODULE,
503         .probe                  = mt9t031_video_probe,
504         .remove                 = mt9t031_video_remove,
505         .init                   = mt9t031_init,
506         .release                = mt9t031_release,
507         .start_capture          = mt9t031_start_capture,
508         .stop_capture           = mt9t031_stop_capture,
509         .set_crop               = mt9t031_set_crop,
510         .set_fmt                = mt9t031_set_fmt,
511         .try_fmt                = mt9t031_try_fmt,
512         .set_bus_param          = mt9t031_set_bus_param,
513         .query_bus_param        = mt9t031_query_bus_param,
514         .controls               = mt9t031_controls,
515         .num_controls           = ARRAY_SIZE(mt9t031_controls),
516         .get_control            = mt9t031_get_control,
517         .set_control            = mt9t031_set_control,
518         .get_chip_id            = mt9t031_get_chip_id,
519 #ifdef CONFIG_VIDEO_ADV_DEBUG
520         .get_register           = mt9t031_get_register,
521         .set_register           = mt9t031_set_register,
522 #endif
523 };
524
525 static int mt9t031_get_control(struct soc_camera_device *icd, struct v4l2_control *ctrl)
526 {
527         struct i2c_client *client = to_i2c_client(icd->control);
528         struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
529         int data;
530
531         switch (ctrl->id) {
532         case V4L2_CID_VFLIP:
533                 data = reg_read(client, MT9T031_READ_MODE_2);
534                 if (data < 0)
535                         return -EIO;
536                 ctrl->value = !!(data & 0x8000);
537                 break;
538         case V4L2_CID_HFLIP:
539                 data = reg_read(client, MT9T031_READ_MODE_2);
540                 if (data < 0)
541                         return -EIO;
542                 ctrl->value = !!(data & 0x4000);
543                 break;
544         case V4L2_CID_EXPOSURE_AUTO:
545                 ctrl->value = mt9t031->autoexposure;
546                 break;
547         }
548         return 0;
549 }
550
551 static int mt9t031_set_control(struct soc_camera_device *icd, struct v4l2_control *ctrl)
552 {
553         struct i2c_client *client = to_i2c_client(icd->control);
554         struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
555         const struct v4l2_queryctrl *qctrl;
556         int data;
557
558         qctrl = soc_camera_find_qctrl(&mt9t031_ops, ctrl->id);
559
560         if (!qctrl)
561                 return -EINVAL;
562
563         switch (ctrl->id) {
564         case V4L2_CID_VFLIP:
565                 if (ctrl->value)
566                         data = reg_set(client, MT9T031_READ_MODE_2, 0x8000);
567                 else
568                         data = reg_clear(client, MT9T031_READ_MODE_2, 0x8000);
569                 if (data < 0)
570                         return -EIO;
571                 break;
572         case V4L2_CID_HFLIP:
573                 if (ctrl->value)
574                         data = reg_set(client, MT9T031_READ_MODE_2, 0x4000);
575                 else
576                         data = reg_clear(client, MT9T031_READ_MODE_2, 0x4000);
577                 if (data < 0)
578                         return -EIO;
579                 break;
580         case V4L2_CID_GAIN:
581                 if (ctrl->value > qctrl->maximum || ctrl->value < qctrl->minimum)
582                         return -EINVAL;
583                 /* See Datasheet Table 7, Gain settings. */
584                 if (ctrl->value <= qctrl->default_value) {
585                         /* Pack it into 0..1 step 0.125, register values 0..8 */
586                         unsigned long range = qctrl->default_value - qctrl->minimum;
587                         data = ((ctrl->value - qctrl->minimum) * 8 + range / 2) / range;
588
589                         dev_dbg(&icd->dev, "Setting gain %d\n", data);
590                         data = reg_write(client, MT9T031_GLOBAL_GAIN, data);
591                         if (data < 0)
592                                 return -EIO;
593                 } else {
594                         /* Pack it into 1.125..128 variable step, register values 9..0x7860 */
595                         /* We assume qctrl->maximum - qctrl->default_value - 1 > 0 */
596                         unsigned long range = qctrl->maximum - qctrl->default_value - 1;
597                         /* calculated gain: map 65..127 to 9..1024 step 0.125 */
598                         unsigned long gain = ((ctrl->value - qctrl->default_value - 1) *
599                                                1015 + range / 2) / range + 9;
600
601                         if (gain <= 32)         /* calculated gain 9..32 -> 9..32 */
602                                 data = gain;
603                         else if (gain <= 64)    /* calculated gain 33..64 -> 0x51..0x60 */
604                                 data = ((gain - 32) * 16 + 16) / 32 + 80;
605                         else
606                                 /* calculated gain 65..1024 -> (1..120) << 8 + 0x60 */
607                                 data = (((gain - 64 + 7) * 32) & 0xff00) | 0x60;
608
609                         dev_dbg(&icd->dev, "Setting gain from 0x%x to 0x%x\n",
610                                 reg_read(client, MT9T031_GLOBAL_GAIN), data);
611                         data = reg_write(client, MT9T031_GLOBAL_GAIN, data);
612                         if (data < 0)
613                                 return -EIO;
614                 }
615
616                 /* Success */
617                 icd->gain = ctrl->value;
618                 break;
619         case V4L2_CID_EXPOSURE:
620                 /* mt9t031 has maximum == default */
621                 if (ctrl->value > qctrl->maximum || ctrl->value < qctrl->minimum)
622                         return -EINVAL;
623                 else {
624                         const unsigned long range = qctrl->maximum - qctrl->minimum;
625                         const u32 shutter = ((ctrl->value - qctrl->minimum) * 1048 +
626                                              range / 2) / range + 1;
627                         u32 old;
628
629                         get_shutter(client, &old);
630                         dev_dbg(&icd->dev, "Setting shutter width from %u to %u\n",
631                                 old, shutter);
632                         if (set_shutter(client, shutter) < 0)
633                                 return -EIO;
634                         icd->exposure = ctrl->value;
635                         mt9t031->autoexposure = 0;
636                 }
637                 break;
638         case V4L2_CID_EXPOSURE_AUTO:
639                 if (ctrl->value) {
640                         const u16 vblank = MT9T031_VERTICAL_BLANK;
641                         const u32 shutter_max = MT9T031_MAX_HEIGHT + vblank;
642                         if (set_shutter(client, icd->height +
643                                         icd->y_skip_top + vblank) < 0)
644                                 return -EIO;
645                         qctrl = soc_camera_find_qctrl(icd->ops, V4L2_CID_EXPOSURE);
646                         icd->exposure = (shutter_max / 2 + (icd->height +
647                                          icd->y_skip_top + vblank - 1) *
648                                          (qctrl->maximum - qctrl->minimum)) /
649                                 shutter_max + qctrl->minimum;
650                         mt9t031->autoexposure = 1;
651                 } else
652                         mt9t031->autoexposure = 0;
653                 break;
654         }
655         return 0;
656 }
657
658 /* Interface active, can use i2c. If it fails, it can indeed mean, that
659  * this wasn't our capture interface, so, we wait for the right one */
660 static int mt9t031_video_probe(struct soc_camera_device *icd)
661 {
662         struct i2c_client *client = to_i2c_client(icd->control);
663         struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
664         s32 data;
665         int ret;
666
667         /* We must have a parent by now. And it cannot be a wrong one.
668          * So this entire test is completely redundant. */
669         if (!icd->dev.parent ||
670             to_soc_camera_host(icd->dev.parent)->nr != icd->iface)
671                 return -ENODEV;
672
673         /* Enable the chip */
674         data = reg_write(client, MT9T031_CHIP_ENABLE, 1);
675         dev_dbg(&icd->dev, "write: %d\n", data);
676
677         /* Read out the chip version register */
678         data = reg_read(client, MT9T031_CHIP_VERSION);
679
680         switch (data) {
681         case 0x1621:
682                 mt9t031->model = V4L2_IDENT_MT9T031;
683                 icd->formats = mt9t031_colour_formats;
684                 icd->num_formats = ARRAY_SIZE(mt9t031_colour_formats);
685                 break;
686         default:
687                 ret = -ENODEV;
688                 dev_err(&icd->dev,
689                         "No MT9T031 chip detected, register read %x\n", data);
690                 goto ei2c;
691         }
692
693         dev_info(&icd->dev, "Detected a MT9T031 chip ID %x\n", data);
694
695         /* Now that we know the model, we can start video */
696         ret = soc_camera_video_start(icd);
697         if (ret)
698                 goto evstart;
699
700         return 0;
701
702 evstart:
703 ei2c:
704         return ret;
705 }
706
707 static void mt9t031_video_remove(struct soc_camera_device *icd)
708 {
709         struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
710
711         dev_dbg(&icd->dev, "Video %x removed: %p, %p\n", mt9t031->client->addr,
712                 icd->dev.parent, icd->vdev);
713         soc_camera_video_stop(icd);
714 }
715
716 static int mt9t031_probe(struct i2c_client *client,
717                          const struct i2c_device_id *did)
718 {
719         struct mt9t031 *mt9t031;
720         struct soc_camera_device *icd;
721         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
722         struct soc_camera_link *icl = client->dev.platform_data;
723         int ret;
724
725         if (!icl) {
726                 dev_err(&client->dev, "MT9T031 driver needs platform data\n");
727                 return -EINVAL;
728         }
729
730         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
731                 dev_warn(&adapter->dev,
732                          "I2C-Adapter doesn't support I2C_FUNC_SMBUS_WORD\n");
733                 return -EIO;
734         }
735
736         mt9t031 = kzalloc(sizeof(struct mt9t031), GFP_KERNEL);
737         if (!mt9t031)
738                 return -ENOMEM;
739
740         mt9t031->client = client;
741         i2c_set_clientdata(client, mt9t031);
742
743         /* Second stage probe - when a capture adapter is there */
744         icd = &mt9t031->icd;
745         icd->ops        = &mt9t031_ops;
746         icd->control    = &client->dev;
747         icd->x_min      = MT9T031_COLUMN_SKIP;
748         icd->y_min      = MT9T031_ROW_SKIP;
749         icd->x_current  = icd->x_min;
750         icd->y_current  = icd->y_min;
751         icd->width_min  = MT9T031_MIN_WIDTH;
752         icd->width_max  = MT9T031_MAX_WIDTH;
753         icd->height_min = MT9T031_MIN_HEIGHT;
754         icd->height_max = MT9T031_MAX_HEIGHT;
755         icd->y_skip_top = 0;
756         icd->iface      = icl->bus_id;
757         /* Simulated autoexposure. If enabled, we calculate shutter width
758          * ourselves in the driver based on vertical blanking and frame width */
759         mt9t031->autoexposure = 1;
760
761         mt9t031->xskip = 1;
762         mt9t031->yskip = 1;
763
764         ret = soc_camera_device_register(icd);
765         if (ret)
766                 goto eisdr;
767
768         return 0;
769
770 eisdr:
771         i2c_set_clientdata(client, NULL);
772         kfree(mt9t031);
773         return ret;
774 }
775
776 static int mt9t031_remove(struct i2c_client *client)
777 {
778         struct mt9t031 *mt9t031 = i2c_get_clientdata(client);
779
780         soc_camera_device_unregister(&mt9t031->icd);
781         i2c_set_clientdata(client, NULL);
782         kfree(mt9t031);
783
784         return 0;
785 }
786
787 static const struct i2c_device_id mt9t031_id[] = {
788         { "mt9t031", 0 },
789         { }
790 };
791 MODULE_DEVICE_TABLE(i2c, mt9t031_id);
792
793 static struct i2c_driver mt9t031_i2c_driver = {
794         .driver = {
795                 .name = "mt9t031",
796         },
797         .probe          = mt9t031_probe,
798         .remove         = mt9t031_remove,
799         .id_table       = mt9t031_id,
800 };
801
802 static int __init mt9t031_mod_init(void)
803 {
804         return i2c_add_driver(&mt9t031_i2c_driver);
805 }
806
807 static void __exit mt9t031_mod_exit(void)
808 {
809         i2c_del_driver(&mt9t031_i2c_driver);
810 }
811
812 module_init(mt9t031_mod_init);
813 module_exit(mt9t031_mod_exit);
814
815 MODULE_DESCRIPTION("Micron MT9T031 Camera driver");
816 MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
817 MODULE_LICENSE("GPL v2");