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-subdev.h>
  17 #include <media/v4l2-chip-ident.h>
  18 #include <media/soc_camera.h>
  19
  20 /*
  21  * mt9t031 i2c address 0x5d
  22  * The platform has to define i2c_board_info and link to it from
  23  * struct soc_camera_link
  24  */
  25
  26 /* mt9t031 selected register addresses */
  27 #define MT9T031_CHIP_VERSION            0x00
  28 #define MT9T031_ROW_START               0x01
  29 #define MT9T031_COLUMN_START            0x02
  30 #define MT9T031_WINDOW_HEIGHT           0x03
  31 #define MT9T031_WINDOW_WIDTH            0x04
  32 #define MT9T031_HORIZONTAL_BLANKING     0x05
  33 #define MT9T031_VERTICAL_BLANKING       0x06
  34 #define MT9T031_OUTPUT_CONTROL          0x07
  35 #define MT9T031_SHUTTER_WIDTH_UPPER     0x08
  36 #define MT9T031_SHUTTER_WIDTH           0x09
  37 #define MT9T031_PIXEL_CLOCK_CONTROL     0x0a
  38 #define MT9T031_FRAME_RESTART           0x0b
  39 #define MT9T031_SHUTTER_DELAY           0x0c
  40 #define MT9T031_RESET                   0x0d
  41 #define MT9T031_READ_MODE_1             0x1e
  42 #define MT9T031_READ_MODE_2             0x20
  43 #define MT9T031_READ_MODE_3             0x21
  44 #define MT9T031_ROW_ADDRESS_MODE        0x22
  45 #define MT9T031_COLUMN_ADDRESS_MODE     0x23
  46 #define MT9T031_GLOBAL_GAIN             0x35
  47 #define MT9T031_CHIP_ENABLE             0xF8
  48
  49 #define MT9T031_MAX_HEIGHT              1536
  50 #define MT9T031_MAX_WIDTH               2048
  51 #define MT9T031_MIN_HEIGHT              2
  52 #define MT9T031_MIN_WIDTH               18
  53 #define MT9T031_HORIZONTAL_BLANK        142
  54 #define MT9T031_VERTICAL_BLANK          25
  55 #define MT9T031_COLUMN_SKIP             32
  56 #define MT9T031_ROW_SKIP                20
  57
  58 #define MT9T031_BUS_PARAM       (SOCAM_PCLK_SAMPLE_RISING |     \
  59         SOCAM_PCLK_SAMPLE_FALLING | SOCAM_HSYNC_ACTIVE_HIGH |   \
  60         SOCAM_VSYNC_ACTIVE_HIGH | SOCAM_DATA_ACTIVE_HIGH |      \
  61         SOCAM_MASTER | SOCAM_DATAWIDTH_10)
  62
  63 struct mt9t031 {
  64         struct v4l2_subdev subdev;
  65         struct v4l2_rect rect;  /* Sensor window */
  66         int model;      /* V4L2_IDENT_MT9T031* codes from v4l2-chip-ident.h */
  67         u16 xskip;
  68         u16 yskip;
  69         unsigned int gain;
  70         unsigned short y_skip_top;      /* Lines to skip at the top */
  71         unsigned int exposure;
  72         unsigned char autoexposure;
  73 };
  74
  75 static struct mt9t031 *to_mt9t031(const struct i2c_client *client)
  76 {
  77         return container_of(i2c_get_clientdata(client), struct mt9t031, subdev);
  78 }
  79
  80 static int reg_read(struct i2c_client *client, const u8 reg)
  81 {
  82         s32 data = i2c_smbus_read_word_data(client, reg);
  83         return data < 0 ? data : swab16(data);
  84 }
  85
  86 static int reg_write(struct i2c_client *client, const u8 reg,
  87                      const u16 data)
  88 {
  89         return i2c_smbus_write_word_data(client, reg, swab16(data));
  90 }
  91
  92 static int reg_set(struct i2c_client *client, const u8 reg,
  93                    const u16 data)
  94 {
  95         int ret;
  96
  97         ret = reg_read(client, reg);
  98         if (ret < 0)
  99                 return ret;
 100         return reg_write(client, reg, ret | data);
 101 }
 102
 103 static int reg_clear(struct i2c_client *client, const u8 reg,
 104                      const u16 data)
 105 {
 106         int ret;
 107
 108         ret = reg_read(client, reg);
 109         if (ret < 0)
 110                 return ret;
 111         return reg_write(client, reg, ret & ~data);
 112 }
 113
 114 static int set_shutter(struct i2c_client *client, const u32 data)
 115 {
 116         int ret;
 117
 118         ret = reg_write(client, MT9T031_SHUTTER_WIDTH_UPPER, data >> 16);
 119
 120         if (ret >= 0)
 121                 ret = reg_write(client, MT9T031_SHUTTER_WIDTH, data & 0xffff);
 122
 123         return ret;
 124 }
 125
 126 static int get_shutter(struct i2c_client *client, u32 *data)
 127 {
 128         int ret;
 129
 130         ret = reg_read(client, MT9T031_SHUTTER_WIDTH_UPPER);
 131         *data = ret << 16;
 132
 133         if (ret >= 0)
 134                 ret = reg_read(client, MT9T031_SHUTTER_WIDTH);
 135         *data |= ret & 0xffff;
 136
 137         return ret < 0 ? ret : 0;
 138 }
 139
 140 static int mt9t031_idle(struct i2c_client *client)
 141 {
 142         int ret;
 143
 144         /* Disable chip output, synchronous option update */
 145         ret = reg_write(client, MT9T031_RESET, 1);
 146         if (ret >= 0)
 147                 ret = reg_write(client, MT9T031_RESET, 0);
 148         if (ret >= 0)
 149                 ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
 150
 151         return ret >= 0 ? 0 : -EIO;
 152 }
 153
 154 static int mt9t031_disable(struct i2c_client *client)
 155 {
 156         /* Disable the chip */
 157         reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
 158
 159         return 0;
 160 }
 161
 162 static int mt9t031_s_stream(struct v4l2_subdev *sd, int enable)
 163 {
 164         struct i2c_client *client = sd->priv;
 165         int ret;
 166
 167         if (enable)
 168                 /* Switch to master "normal" mode */
 169                 ret = reg_set(client, MT9T031_OUTPUT_CONTROL, 2);
 170         else
 171                 /* Stop sensor readout */
 172                 ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
 173
 174         if (ret < 0)
 175                 return -EIO;
 176
 177         return 0;
 178 }
 179
 180 static int mt9t031_set_bus_param(struct soc_camera_device *icd,
 181                                  unsigned long flags)
 182 {
 183         struct i2c_client *client = to_i2c_client(to_soc_camera_control(icd));
 184
 185         /* The caller should have queried our parameters, check anyway */
 186         if (flags & ~MT9T031_BUS_PARAM)
 187                 return -EINVAL;
 188
 189         if (flags & SOCAM_PCLK_SAMPLE_FALLING)
 190                 reg_clear(client, MT9T031_PIXEL_CLOCK_CONTROL, 0x8000);
 191         else
 192                 reg_set(client, MT9T031_PIXEL_CLOCK_CONTROL, 0x8000);
 193
 194         return 0;
 195 }
 196
 197 static unsigned long mt9t031_query_bus_param(struct soc_camera_device *icd)
 198 {
 199         struct soc_camera_link *icl = to_soc_camera_link(icd);
 200
 201         return soc_camera_apply_sensor_flags(icl, MT9T031_BUS_PARAM);
 202 }
 203
 204 enum {
 205         MT9T031_CTRL_VFLIP,
 206         MT9T031_CTRL_HFLIP,
 207         MT9T031_CTRL_GAIN,
 208         MT9T031_CTRL_EXPOSURE,
 209         MT9T031_CTRL_EXPOSURE_AUTO,
 210 };
 211
 212 static const struct v4l2_queryctrl mt9t031_controls[] = {
 213         [MT9T031_CTRL_VFLIP] = {
 214                 .id             = V4L2_CID_VFLIP,
 215                 .type           = V4L2_CTRL_TYPE_BOOLEAN,
 216                 .name           = "Flip Vertically",
 217                 .minimum        = 0,
 218                 .maximum        = 1,
 219                 .step           = 1,
 220                 .default_value  = 0,
 221         },
 222         [MT9T031_CTRL_HFLIP] = {
 223                 .id             = V4L2_CID_HFLIP,
 224                 .type           = V4L2_CTRL_TYPE_BOOLEAN,
 225                 .name           = "Flip Horizontally",
 226                 .minimum        = 0,
 227                 .maximum        = 1,
 228                 .step           = 1,
 229                 .default_value  = 0,
 230         },
 231         [MT9T031_CTRL_GAIN] = {
 232                 .id             = V4L2_CID_GAIN,
 233                 .type           = V4L2_CTRL_TYPE_INTEGER,
 234                 .name           = "Gain",
 235                 .minimum        = 0,
 236                 .maximum        = 127,
 237                 .step           = 1,
 238                 .default_value  = 64,
 239                 .flags          = V4L2_CTRL_FLAG_SLIDER,
 240         },
 241         [MT9T031_CTRL_EXPOSURE] = {
 242                 .id             = V4L2_CID_EXPOSURE,
 243                 .type           = V4L2_CTRL_TYPE_INTEGER,
 244                 .name           = "Exposure",
 245                 .minimum        = 1,
 246                 .maximum        = 255,
 247                 .step           = 1,
 248                 .default_value  = 255,
 249                 .flags          = V4L2_CTRL_FLAG_SLIDER,
 250         },
 251         [MT9T031_CTRL_EXPOSURE_AUTO] = {
 252                 .id             = V4L2_CID_EXPOSURE_AUTO,
 253                 .type           = V4L2_CTRL_TYPE_BOOLEAN,
 254                 .name           = "Automatic Exposure",
 255                 .minimum        = 0,
 256                 .maximum        = 1,
 257                 .step           = 1,
 258                 .default_value  = 1,
 259         }
 260 };
 261
 262 static struct soc_camera_ops mt9t031_ops = {
 263         .set_bus_param          = mt9t031_set_bus_param,
 264         .query_bus_param        = mt9t031_query_bus_param,
 265         .controls               = mt9t031_controls,
 266         .num_controls           = ARRAY_SIZE(mt9t031_controls),
 267 };
 268
 269 /* target must be _even_ */
 270 static u16 mt9t031_skip(s32 *source, s32 target, s32 max)
 271 {
 272         unsigned int skip;
 273
 274         if (*source < target + target / 2) {
 275                 *source = target;
 276                 return 1;
 277         }
 278
 279         skip = min(max, *source + target / 2) / target;
 280         if (skip > 8)
 281                 skip = 8;
 282         *source = target * skip;
 283
 284         return skip;
 285 }
 286
 287 /* rect is the sensor rectangle, the caller guarantees parameter validity */
 288 static int mt9t031_set_params(struct i2c_client *client,
 289                               struct v4l2_rect *rect, u16 xskip, u16 yskip)
 290 {
 291         struct mt9t031 *mt9t031 = to_mt9t031(client);
 292         int ret;
 293         u16 xbin, ybin;
 294         const u16 hblank = MT9T031_HORIZONTAL_BLANK,
 295                 vblank = MT9T031_VERTICAL_BLANK;
 296
 297         xbin = min(xskip, (u16)3);
 298         ybin = min(yskip, (u16)3);
 299
 300         /*
 301          * Could just do roundup(rect->left, [xy]bin * 2); but this is cheaper.
 302          * There is always a valid suitably aligned value. The worst case is
 303          * xbin = 3, width = 2048. Then we will start at 36, the last read out
 304          * pixel will be 2083, which is < 2085 - first black pixel.
 305          *
 306          * MT9T031 datasheet imposes window left border alignment, depending on
 307          * the selected xskip. Failing to conform to this requirement produces
 308          * dark horizontal stripes in the image. However, even obeying to this
 309          * requirement doesn't eliminate the stripes in all configurations. They
 310          * appear "locally reproducibly," but can differ between tests under
 311          * different lighting conditions.
 312          */
 313         switch (xbin) {
 314         case 1:
 315                 rect->left &= ~1;
 316                 break;
 317         case 2:
 318                 rect->left &= ~3;
 319                 break;
 320         case 3:
 321                 rect->left = rect->left > roundup(MT9T031_COLUMN_SKIP, 6) ?
 322                         (rect->left / 6) * 6 : roundup(MT9T031_COLUMN_SKIP, 6);
 323         }
 324
 325         rect->top &= ~1;
 326
 327         dev_dbg(&client->dev, "skip %u:%u, rect %ux%u@%u:%u\n",
 328                 xskip, yskip, rect->width, rect->height, rect->left, rect->top);
 329
 330         /* Disable register update, reconfigure atomically */
 331         ret = reg_set(client, MT9T031_OUTPUT_CONTROL, 1);
 332         if (ret < 0)
 333                 return ret;
 334
 335         /* Blanking and start values - default... */
 336         ret = reg_write(client, MT9T031_HORIZONTAL_BLANKING, hblank);
 337         if (ret >= 0)
 338                 ret = reg_write(client, MT9T031_VERTICAL_BLANKING, vblank);
 339
 340         if (yskip != mt9t031->yskip || xskip != mt9t031->xskip) {
 341                 /* Binning, skipping */
 342                 if (ret >= 0)
 343                         ret = reg_write(client, MT9T031_COLUMN_ADDRESS_MODE,
 344                                         ((xbin - 1) << 4) | (xskip - 1));
 345                 if (ret >= 0)
 346                         ret = reg_write(client, MT9T031_ROW_ADDRESS_MODE,
 347                                         ((ybin - 1) << 4) | (yskip - 1));
 348         }
 349         dev_dbg(&client->dev, "new physical left %u, top %u\n",
 350                 rect->left, rect->top);
 351
 352         /*
 353          * The caller provides a supported format, as guaranteed by
 354          * icd->try_fmt_cap(), soc_camera_s_crop() and soc_camera_cropcap()
 355          */
 356         if (ret >= 0)
 357                 ret = reg_write(client, MT9T031_COLUMN_START, rect->left);
 358         if (ret >= 0)
 359                 ret = reg_write(client, MT9T031_ROW_START, rect->top);
 360         if (ret >= 0)
 361                 ret = reg_write(client, MT9T031_WINDOW_WIDTH, rect->width - 1);
 362         if (ret >= 0)
 363                 ret = reg_write(client, MT9T031_WINDOW_HEIGHT,
 364                                 rect->height + mt9t031->y_skip_top - 1);
 365         if (ret >= 0 && mt9t031->autoexposure) {
 366                 unsigned int total_h = rect->height + mt9t031->y_skip_top + vblank;
 367                 ret = set_shutter(client, total_h);
 368                 if (ret >= 0) {
 369                         const u32 shutter_max = MT9T031_MAX_HEIGHT + vblank;
 370                         const struct v4l2_queryctrl *qctrl =
 371                                 &mt9t031_controls[MT9T031_CTRL_EXPOSURE];
 372                         mt9t031->exposure = (shutter_max / 2 + (total_h - 1) *
 373                                  (qctrl->maximum - qctrl->minimum)) /
 374                                 shutter_max + qctrl->minimum;
 375                 }
 376         }
 377
 378         /* Re-enable register update, commit all changes */
 379         if (ret >= 0)
 380                 ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 1);
 381
 382         if (ret >= 0) {
 383                 mt9t031->rect = *rect;
 384                 mt9t031->xskip = xskip;
 385                 mt9t031->yskip = yskip;
 386         }
 387
 388         return ret < 0 ? ret : 0;
 389 }
 390
 391 static int mt9t031_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
 392 {
 393         struct v4l2_rect rect = a->c;
 394         struct i2c_client *client = sd->priv;
 395         struct mt9t031 *mt9t031 = to_mt9t031(client);
 396
 397         rect.width = ALIGN(rect.width, 2);
 398         rect.height = ALIGN(rect.height, 2);
 399
 400         soc_camera_limit_side(&rect.left, &rect.width,
 401                      MT9T031_COLUMN_SKIP, MT9T031_MIN_WIDTH, MT9T031_MAX_WIDTH);
 402
 403         soc_camera_limit_side(&rect.top, &rect.height,
 404                      MT9T031_ROW_SKIP, MT9T031_MIN_HEIGHT, MT9T031_MAX_HEIGHT);
 405
 406         return mt9t031_set_params(client, &rect, mt9t031->xskip, mt9t031->yskip);
 407 }
 408
 409 static int mt9t031_g_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
 410 {
 411         struct i2c_client *client = sd->priv;
 412         struct mt9t031 *mt9t031 = to_mt9t031(client);
 413
 414         a->c    = mt9t031->rect;
 415         a->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 416
 417         return 0;
 418 }
 419
 420 static int mt9t031_cropcap(struct v4l2_subdev *sd, struct v4l2_cropcap *a)
 421 {
 422         a->bounds.left                  = MT9T031_COLUMN_SKIP;
 423         a->bounds.top                   = MT9T031_ROW_SKIP;
 424         a->bounds.width                 = MT9T031_MAX_WIDTH;
 425         a->bounds.height                = MT9T031_MAX_HEIGHT;
 426         a->defrect                      = a->bounds;
 427         a->type                         = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 428         a->pixelaspect.numerator        = 1;
 429         a->pixelaspect.denominator      = 1;
 430
 431         return 0;
 432 }
 433
 434 static int mt9t031_g_fmt(struct v4l2_subdev *sd,
 435                          struct v4l2_mbus_framefmt *mf)
 436 {
 437         struct i2c_client *client = sd->priv;
 438         struct mt9t031 *mt9t031 = to_mt9t031(client);
 439
 440         mf->width       = mt9t031->rect.width / mt9t031->xskip;
 441         mf->height      = mt9t031->rect.height / mt9t031->yskip;
 442         mf->code        = V4L2_MBUS_FMT_SBGGR10_1X10;
 443         mf->colorspace  = V4L2_COLORSPACE_SRGB;
 444         mf->field       = V4L2_FIELD_NONE;
 445
 446         return 0;
 447 }
 448
 449 static int mt9t031_s_fmt(struct v4l2_subdev *sd,
 450                          struct v4l2_mbus_framefmt *mf)
 451 {
 452         struct i2c_client *client = sd->priv;
 453         struct mt9t031 *mt9t031 = to_mt9t031(client);
 454         u16 xskip, yskip;
 455         struct v4l2_rect rect = mt9t031->rect;
 456
 457         /*
 458          * try_fmt has put width and height within limits.
 459          * S_FMT: use binning and skipping for scaling
 460          */
 461         xskip = mt9t031_skip(&rect.width, mf->width, MT9T031_MAX_WIDTH);
 462         yskip = mt9t031_skip(&rect.height, mf->height, MT9T031_MAX_HEIGHT);
 463
 464         mf->code        = V4L2_MBUS_FMT_SBGGR10_1X10;
 465         mf->colorspace  = V4L2_COLORSPACE_SRGB;
 466
 467         /* mt9t031_set_params() doesn't change width and height */
 468         return mt9t031_set_params(client, &rect, xskip, yskip);
 469 }
 470
 471 /*
 472  * If a user window larger than sensor window is requested, we'll increase the
 473  * sensor window.
 474  */
 475 static int mt9t031_try_fmt(struct v4l2_subdev *sd,
 476                            struct v4l2_mbus_framefmt *mf)
 477 {
 478         v4l_bound_align_image(
 479                 &mf->width, MT9T031_MIN_WIDTH, MT9T031_MAX_WIDTH, 1,
 480                 &mf->height, MT9T031_MIN_HEIGHT, MT9T031_MAX_HEIGHT, 1, 0);
 481
 482         mf->code        = V4L2_MBUS_FMT_SBGGR10_1X10;
 483         mf->colorspace  = V4L2_COLORSPACE_SRGB;
 484
 485         return 0;
 486 }
 487
 488 static int mt9t031_g_chip_ident(struct v4l2_subdev *sd,
 489                                 struct v4l2_dbg_chip_ident *id)
 490 {
 491         struct i2c_client *client = sd->priv;
 492         struct mt9t031 *mt9t031 = to_mt9t031(client);
 493
 494         if (id->match.type != V4L2_CHIP_MATCH_I2C_ADDR)
 495                 return -EINVAL;
 496
 497         if (id->match.addr != client->addr)
 498                 return -ENODEV;
 499
 500         id->ident       = mt9t031->model;
 501         id->revision    = 0;
 502
 503         return 0;
 504 }
 505
 506 #ifdef CONFIG_VIDEO_ADV_DEBUG
 507 static int mt9t031_g_register(struct v4l2_subdev *sd,
 508                               struct v4l2_dbg_register *reg)
 509 {
 510         struct i2c_client *client = sd->priv;
 511
 512         if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
 513                 return -EINVAL;
 514
 515         if (reg->match.addr != client->addr)
 516                 return -ENODEV;
 517
 518         reg->val = reg_read(client, reg->reg);
 519
 520         if (reg->val > 0xffff)
 521                 return -EIO;
 522
 523         return 0;
 524 }
 525
 526 static int mt9t031_s_register(struct v4l2_subdev *sd,
 527                               struct v4l2_dbg_register *reg)
 528 {
 529         struct i2c_client *client = sd->priv;
 530
 531         if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
 532                 return -EINVAL;
 533
 534         if (reg->match.addr != client->addr)
 535                 return -ENODEV;
 536
 537         if (reg_write(client, reg->reg, reg->val) < 0)
 538                 return -EIO;
 539
 540         return 0;
 541 }
 542 #endif
 543
 544 static int mt9t031_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
 545 {
 546         struct i2c_client *client = sd->priv;
 547         struct mt9t031 *mt9t031 = to_mt9t031(client);
 548         int data;
 549
 550         switch (ctrl->id) {
 551         case V4L2_CID_VFLIP:
 552                 data = reg_read(client, MT9T031_READ_MODE_2);
 553                 if (data < 0)
 554                         return -EIO;
 555                 ctrl->value = !!(data & 0x8000);
 556                 break;
 557         case V4L2_CID_HFLIP:
 558                 data = reg_read(client, MT9T031_READ_MODE_2);
 559                 if (data < 0)
 560                         return -EIO;
 561                 ctrl->value = !!(data & 0x4000);
 562                 break;
 563         case V4L2_CID_EXPOSURE_AUTO:
 564                 ctrl->value = mt9t031->autoexposure;
 565                 break;
 566         case V4L2_CID_GAIN:
 567                 ctrl->value = mt9t031->gain;
 568                 break;
 569         case V4L2_CID_EXPOSURE:
 570                 ctrl->value = mt9t031->exposure;
 571                 break;
 572         }
 573         return 0;
 574 }
 575
 576 static int mt9t031_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
 577 {
 578         struct i2c_client *client = sd->priv;
 579         struct mt9t031 *mt9t031 = to_mt9t031(client);
 580         const struct v4l2_queryctrl *qctrl;
 581         int data;
 582
 583         switch (ctrl->id) {
 584         case V4L2_CID_VFLIP:
 585                 if (ctrl->value)
 586                         data = reg_set(client, MT9T031_READ_MODE_2, 0x8000);
 587                 else
 588                         data = reg_clear(client, MT9T031_READ_MODE_2, 0x8000);
 589                 if (data < 0)
 590                         return -EIO;
 591                 break;
 592         case V4L2_CID_HFLIP:
 593                 if (ctrl->value)
 594                         data = reg_set(client, MT9T031_READ_MODE_2, 0x4000);
 595                 else
 596                         data = reg_clear(client, MT9T031_READ_MODE_2, 0x4000);
 597                 if (data < 0)
 598                         return -EIO;
 599                 break;
 600         case V4L2_CID_GAIN:
 601                 qctrl = &mt9t031_controls[MT9T031_CTRL_GAIN];
 602                 if (ctrl->value > qctrl->maximum || ctrl->value < qctrl->minimum)
 603                         return -EINVAL;
 604                 /* See Datasheet Table 7, Gain settings. */
 605                 if (ctrl->value <= qctrl->default_value) {
 606                         /* Pack it into 0..1 step 0.125, register values 0..8 */
 607                         unsigned long range = qctrl->default_value - qctrl->minimum;
 608                         data = ((ctrl->value - qctrl->minimum) * 8 + range / 2) / range;
 609
 610                         dev_dbg(&client->dev, "Setting gain %d\n", data);
 611                         data = reg_write(client, MT9T031_GLOBAL_GAIN, data);
 612                         if (data < 0)
 613                                 return -EIO;
 614                 } else {
 615                         /* Pack it into 1.125..128 variable step, register values 9..0x7860 */
 616                         /* We assume qctrl->maximum - qctrl->default_value - 1 > 0 */
 617                         unsigned long range = qctrl->maximum - qctrl->default_value - 1;
 618                         /* calculated gain: map 65..127 to 9..1024 step 0.125 */
 619                         unsigned long gain = ((ctrl->value - qctrl->default_value - 1) *
 620                                                1015 + range / 2) / range + 9;
 621
 622                         if (gain <= 32)         /* calculated gain 9..32 -> 9..32 */
 623                                 data = gain;
 624                         else if (gain <= 64)    /* calculated gain 33..64 -> 0x51..0x60 */
 625                                 data = ((gain - 32) * 16 + 16) / 32 + 80;
 626                         else
 627                                 /* calculated gain 65..1024 -> (1..120) << 8 + 0x60 */
 628                                 data = (((gain - 64 + 7) * 32) & 0xff00) | 0x60;
 629
 630                         dev_dbg(&client->dev, "Set gain from 0x%x to 0x%x\n",
 631                                 reg_read(client, MT9T031_GLOBAL_GAIN), data);
 632                         data = reg_write(client, MT9T031_GLOBAL_GAIN, data);
 633                         if (data < 0)
 634                                 return -EIO;
 635                 }
 636
 637                 /* Success */
 638                 mt9t031->gain = ctrl->value;
 639                 break;
 640         case V4L2_CID_EXPOSURE:
 641                 qctrl = &mt9t031_controls[MT9T031_CTRL_EXPOSURE];
 642                 /* mt9t031 has maximum == default */
 643                 if (ctrl->value > qctrl->maximum || ctrl->value < qctrl->minimum)
 644                         return -EINVAL;
 645                 else {
 646                         const unsigned long range = qctrl->maximum - qctrl->minimum;
 647                         const u32 shutter = ((ctrl->value - qctrl->minimum) * 1048 +
 648                                              range / 2) / range + 1;
 649                         u32 old;
 650
 651                         get_shutter(client, &old);
 652                         dev_dbg(&client->dev, "Set shutter from %u to %u\n",
 653                                 old, shutter);
 654                         if (set_shutter(client, shutter) < 0)
 655                                 return -EIO;
 656                         mt9t031->exposure = ctrl->value;
 657                         mt9t031->autoexposure = 0;
 658                 }
 659                 break;
 660         case V4L2_CID_EXPOSURE_AUTO:
 661                 if (ctrl->value) {
 662                         const u16 vblank = MT9T031_VERTICAL_BLANK;
 663                         const u32 shutter_max = MT9T031_MAX_HEIGHT + vblank;
 664                         unsigned int total_h = mt9t031->rect.height +
 665                                 mt9t031->y_skip_top + vblank;
 666
 667                         if (set_shutter(client, total_h) < 0)
 668                                 return -EIO;
 669                         qctrl = &mt9t031_controls[MT9T031_CTRL_EXPOSURE];
 670                         mt9t031->exposure = (shutter_max / 2 + (total_h - 1) *
 671                                  (qctrl->maximum - qctrl->minimum)) /
 672                                 shutter_max + qctrl->minimum;
 673                         mt9t031->autoexposure = 1;
 674                 } else
 675                         mt9t031->autoexposure = 0;
 676                 break;
 677         default:
 678                 return -EINVAL;
 679         }
 680         return 0;
 681 }
 682
 683 /*
 684  * Interface active, can use i2c. If it fails, it can indeed mean, that
 685  * this wasn't our capture interface, so, we wait for the right one
 686  */
 687 static int mt9t031_video_probe(struct i2c_client *client)
 688 {
 689         struct mt9t031 *mt9t031 = to_mt9t031(client);
 690         s32 data;
 691         int ret;
 692
 693         /* Enable the chip */
 694         data = reg_write(client, MT9T031_CHIP_ENABLE, 1);
 695         dev_dbg(&client->dev, "write: %d\n", data);
 696
 697         /* Read out the chip version register */
 698         data = reg_read(client, MT9T031_CHIP_VERSION);
 699
 700         switch (data) {
 701         case 0x1621:
 702                 mt9t031->model = V4L2_IDENT_MT9T031;
 703                 break;
 704         default:
 705                 dev_err(&client->dev,
 706                         "No MT9T031 chip detected, register read %x\n", data);
 707                 return -ENODEV;
 708         }
 709
 710         dev_info(&client->dev, "Detected a MT9T031 chip ID %x\n", data);
 711
 712         ret = mt9t031_idle(client);
 713         if (ret < 0)
 714                 dev_err(&client->dev, "Failed to initialise the camera\n");
 715
 716         /* mt9t031_idle() has reset the chip to default. */
 717         mt9t031->exposure = 255;
 718         mt9t031->gain = 64;
 719
 720         return ret;
 721 }
 722
 723 static int mt9t031_g_skip_top_lines(struct v4l2_subdev *sd, u32 *lines)
 724 {
 725         struct i2c_client *client = sd->priv;
 726         struct mt9t031 *mt9t031 = to_mt9t031(client);
 727
 728         *lines = mt9t031->y_skip_top;
 729
 730         return 0;
 731 }
 732
 733 static struct v4l2_subdev_core_ops mt9t031_subdev_core_ops = {
 734         .g_ctrl         = mt9t031_g_ctrl,
 735         .s_ctrl         = mt9t031_s_ctrl,
 736         .g_chip_ident   = mt9t031_g_chip_ident,
 737 #ifdef CONFIG_VIDEO_ADV_DEBUG
 738         .g_register     = mt9t031_g_register,
 739         .s_register     = mt9t031_s_register,
 740 #endif
 741 };
 742
 743 static int mt9t031_enum_fmt(struct v4l2_subdev *sd, int index,
 744                             enum v4l2_mbus_pixelcode *code)
 745 {
 746         if (index)
 747                 return -EINVAL;
 748
 749         *code = V4L2_MBUS_FMT_SBGGR10_1X10;
 750         return 0;
 751 }
 752
 753 static struct v4l2_subdev_video_ops mt9t031_subdev_video_ops = {
 754         .s_stream       = mt9t031_s_stream,
 755         .s_mbus_fmt     = mt9t031_s_fmt,
 756         .g_mbus_fmt     = mt9t031_g_fmt,
 757         .try_mbus_fmt   = mt9t031_try_fmt,
 758         .s_crop         = mt9t031_s_crop,
 759         .g_crop         = mt9t031_g_crop,
 760         .cropcap        = mt9t031_cropcap,
 761         .enum_mbus_fmt  = mt9t031_enum_fmt,
 762 };
 763
 764 static struct v4l2_subdev_sensor_ops mt9t031_subdev_sensor_ops = {
 765         .g_skip_top_lines       = mt9t031_g_skip_top_lines,
 766 };
 767
 768 static struct v4l2_subdev_ops mt9t031_subdev_ops = {
 769         .core   = &mt9t031_subdev_core_ops,
 770         .video  = &mt9t031_subdev_video_ops,
 771         .sensor = &mt9t031_subdev_sensor_ops,
 772 };
 773
 774 static int mt9t031_probe(struct i2c_client *client,
 775                          const struct i2c_device_id *did)
 776 {
 777         struct mt9t031 *mt9t031;
 778         struct soc_camera_device *icd = client->dev.platform_data;
 779         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 780         int ret;
 781
 782         if (icd) {
 783                 struct soc_camera_link *icl = to_soc_camera_link(icd);
 784                 if (!icl) {
 785                         dev_err(&client->dev, "MT9T031 driver needs platform data\n");
 786                         return -EINVAL;
 787                 }
 788
 789                 icd->ops = &mt9t031_ops;
 790         }
 791
 792         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
 793                 dev_warn(&adapter->dev,
 794                          "I2C-Adapter doesn't support I2C_FUNC_SMBUS_WORD\n");
 795                 return -EIO;
 796         }
 797
 798         mt9t031 = kzalloc(sizeof(struct mt9t031), GFP_KERNEL);
 799         if (!mt9t031)
 800                 return -ENOMEM;
 801
 802         v4l2_i2c_subdev_init(&mt9t031->subdev, client, &mt9t031_subdev_ops);
 803
 804         mt9t031->y_skip_top     = 0;
 805         mt9t031->rect.left      = MT9T031_COLUMN_SKIP;
 806         mt9t031->rect.top       = MT9T031_ROW_SKIP;
 807         mt9t031->rect.width     = MT9T031_MAX_WIDTH;
 808         mt9t031->rect.height    = MT9T031_MAX_HEIGHT;
 809
 810         /*
 811          * Simulated autoexposure. If enabled, we calculate shutter width
 812          * ourselves in the driver based on vertical blanking and frame width
 813          */
 814         mt9t031->autoexposure = 1;
 815
 816         mt9t031->xskip = 1;
 817         mt9t031->yskip = 1;
 818
 819         mt9t031_idle(client);
 820
 821         ret = mt9t031_video_probe(client);
 822
 823         mt9t031_disable(client);
 824
 825         if (ret) {
 826                 if (icd)
 827                         icd->ops = NULL;
 828                 i2c_set_clientdata(client, NULL);
 829                 kfree(mt9t031);
 830         }
 831
 832         return ret;
 833 }
 834
 835 static int mt9t031_remove(struct i2c_client *client)
 836 {
 837         struct mt9t031 *mt9t031 = to_mt9t031(client);
 838         struct soc_camera_device *icd = client->dev.platform_data;
 839
 840         if (icd)
 841                 icd->ops = NULL;
 842         i2c_set_clientdata(client, NULL);
 843         client->driver = NULL;
 844         kfree(mt9t031);
 845
 846         return 0;
 847 }
 848
 849 static const struct i2c_device_id mt9t031_id[] = {
 850         { "mt9t031", 0 },
 851         { }
 852 };
 853 MODULE_DEVICE_TABLE(i2c, mt9t031_id);
 854
 855 static struct i2c_driver mt9t031_i2c_driver = {
 856         .driver = {
 857                 .name = "mt9t031",
 858         },
 859         .probe          = mt9t031_probe,
 860         .remove         = mt9t031_remove,
 861         .id_table       = mt9t031_id,
 862 };
 863
 864 static int __init mt9t031_mod_init(void)
 865 {
 866         return i2c_add_driver(&mt9t031_i2c_driver);
 867 }
 868
 869 static void __exit mt9t031_mod_exit(void)
 870 {
 871         i2c_del_driver(&mt9t031_i2c_driver);
 872 }
 873
 874 module_init(mt9t031_mod_init);
 875 module_exit(mt9t031_mod_exit);
 876
 877 MODULE_DESCRIPTION("Micron MT9T031 Camera driver");
 878 MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
 879 MODULE_LICENSE("GPL v2");