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 /* mt9t031 i2c address 0x5d
  21  * The platform has to define i2c_board_info and link to it from
  22  * struct soc_camera_link */
  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               18
  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 v4l2_subdev subdev;
  72         struct v4l2_rect rect;  /* Sensor window */
  73         int model;      /* V4L2_IDENT_MT9T031* codes from v4l2-chip-ident.h */
  74         u16 xskip;
  75         u16 yskip;
  76         unsigned int gain;
  77         unsigned int exposure;
  78         unsigned char autoexposure;
  79 };
  80
  81 static struct mt9t031 *to_mt9t031(const struct i2c_client *client)
  82 {
  83         return container_of(i2c_get_clientdata(client), struct mt9t031, subdev);
  84 }
  85
  86 static int reg_read(struct i2c_client *client, const u8 reg)
  87 {
  88         s32 data = i2c_smbus_read_word_data(client, reg);
  89         return data < 0 ? data : swab16(data);
  90 }
  91
  92 static int reg_write(struct i2c_client *client, const u8 reg,
  93                      const u16 data)
  94 {
  95         return i2c_smbus_write_word_data(client, reg, swab16(data));
  96 }
  97
  98 static int reg_set(struct i2c_client *client, const u8 reg,
  99                    const u16 data)
 100 {
 101         int ret;
 102
 103         ret = reg_read(client, reg);
 104         if (ret < 0)
 105                 return ret;
 106         return reg_write(client, reg, ret | data);
 107 }
 108
 109 static int reg_clear(struct i2c_client *client, const u8 reg,
 110                      const u16 data)
 111 {
 112         int ret;
 113
 114         ret = reg_read(client, reg);
 115         if (ret < 0)
 116                 return ret;
 117         return reg_write(client, reg, ret & ~data);
 118 }
 119
 120 static int set_shutter(struct i2c_client *client, const u32 data)
 121 {
 122         int ret;
 123
 124         ret = reg_write(client, MT9T031_SHUTTER_WIDTH_UPPER, data >> 16);
 125
 126         if (ret >= 0)
 127                 ret = reg_write(client, MT9T031_SHUTTER_WIDTH, data & 0xffff);
 128
 129         return ret;
 130 }
 131
 132 static int get_shutter(struct i2c_client *client, u32 *data)
 133 {
 134         int ret;
 135
 136         ret = reg_read(client, MT9T031_SHUTTER_WIDTH_UPPER);
 137         *data = ret << 16;
 138
 139         if (ret >= 0)
 140                 ret = reg_read(client, MT9T031_SHUTTER_WIDTH);
 141         *data |= ret & 0xffff;
 142
 143         return ret < 0 ? ret : 0;
 144 }
 145
 146 static int mt9t031_idle(struct i2c_client *client)
 147 {
 148         int ret;
 149
 150         /* Disable chip output, synchronous option update */
 151         ret = reg_write(client, MT9T031_RESET, 1);
 152         if (ret >= 0)
 153                 ret = reg_write(client, MT9T031_RESET, 0);
 154         if (ret >= 0)
 155                 ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
 156
 157         return ret >= 0 ? 0 : -EIO;
 158 }
 159
 160 static int mt9t031_disable(struct i2c_client *client)
 161 {
 162         /* Disable the chip */
 163         reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
 164
 165         return 0;
 166 }
 167
 168 static int mt9t031_s_stream(struct v4l2_subdev *sd, int enable)
 169 {
 170         struct i2c_client *client = sd->priv;
 171         int ret;
 172
 173         if (enable)
 174                 /* Switch to master "normal" mode */
 175                 ret = reg_set(client, MT9T031_OUTPUT_CONTROL, 2);
 176         else
 177                 /* Stop sensor readout */
 178                 ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
 179
 180         if (ret < 0)
 181                 return -EIO;
 182
 183         return 0;
 184 }
 185
 186 static int mt9t031_set_bus_param(struct soc_camera_device *icd,
 187                                  unsigned long flags)
 188 {
 189         struct i2c_client *client = to_i2c_client(to_soc_camera_control(icd));
 190
 191         /* The caller should have queried our parameters, check anyway */
 192         if (flags & ~MT9T031_BUS_PARAM)
 193                 return -EINVAL;
 194
 195         if (flags & SOCAM_PCLK_SAMPLE_FALLING)
 196                 reg_clear(client, MT9T031_PIXEL_CLOCK_CONTROL, 0x8000);
 197         else
 198                 reg_set(client, MT9T031_PIXEL_CLOCK_CONTROL, 0x8000);
 199
 200         return 0;
 201 }
 202
 203 static unsigned long mt9t031_query_bus_param(struct soc_camera_device *icd)
 204 {
 205         struct soc_camera_link *icl = to_soc_camera_link(icd);
 206
 207         return soc_camera_apply_sensor_flags(icl, MT9T031_BUS_PARAM);
 208 }
 209
 210 /* target must be _even_ */
 211 static u16 mt9t031_skip(s32 *source, s32 target, s32 max)
 212 {
 213         unsigned int skip;
 214
 215         if (*source < target + target / 2) {
 216                 *source = target;
 217                 return 1;
 218         }
 219
 220         skip = min(max, *source + target / 2) / target;
 221         if (skip > 8)
 222                 skip = 8;
 223         *source = target * skip;
 224
 225         return skip;
 226 }
 227
 228 /* rect is the sensor rectangle, the caller guarantees parameter validity */
 229 static int mt9t031_set_params(struct soc_camera_device *icd,
 230                               struct v4l2_rect *rect, u16 xskip, u16 yskip)
 231 {
 232         struct i2c_client *client = to_i2c_client(to_soc_camera_control(icd));
 233         struct mt9t031 *mt9t031 = to_mt9t031(client);
 234         int ret;
 235         u16 xbin, ybin;
 236         const u16 hblank = MT9T031_HORIZONTAL_BLANK,
 237                 vblank = MT9T031_VERTICAL_BLANK;
 238
 239         xbin = min(xskip, (u16)3);
 240         ybin = min(yskip, (u16)3);
 241
 242         /*
 243          * Could just do roundup(rect->left, [xy]bin * 2); but this is cheaper.
 244          * There is always a valid suitably aligned value. The worst case is
 245          * xbin = 3, width = 2048. Then we will start at 36, the last read out
 246          * pixel will be 2083, which is < 2085 - first black pixel.
 247          *
 248          * MT9T031 datasheet imposes window left border alignment, depending on
 249          * the selected xskip. Failing to conform to this requirement produces
 250          * dark horizontal stripes in the image. However, even obeying to this
 251          * requirement doesn't eliminate the stripes in all configurations. They
 252          * appear "locally reproducibly," but can differ between tests under
 253          * different lighting conditions.
 254          */
 255         switch (xbin) {
 256         case 1:
 257                 rect->left &= ~1;
 258                 break;
 259         case 2:
 260                 rect->left &= ~3;
 261                 break;
 262         case 3:
 263                 rect->left = rect->left > roundup(MT9T031_COLUMN_SKIP, 6) ?
 264                         (rect->left / 6) * 6 : roundup(MT9T031_COLUMN_SKIP, 6);
 265         }
 266
 267         rect->top &= ~1;
 268
 269         dev_dbg(&client->dev, "skip %u:%u, rect %ux%u@%u:%u\n",
 270                 xskip, yskip, rect->width, rect->height, rect->left, rect->top);
 271
 272         /* Disable register update, reconfigure atomically */
 273         ret = reg_set(client, MT9T031_OUTPUT_CONTROL, 1);
 274         if (ret < 0)
 275                 return ret;
 276
 277         /* Blanking and start values - default... */
 278         ret = reg_write(client, MT9T031_HORIZONTAL_BLANKING, hblank);
 279         if (ret >= 0)
 280                 ret = reg_write(client, MT9T031_VERTICAL_BLANKING, vblank);
 281
 282         if (yskip != mt9t031->yskip || xskip != mt9t031->xskip) {
 283                 /* Binning, skipping */
 284                 if (ret >= 0)
 285                         ret = reg_write(client, MT9T031_COLUMN_ADDRESS_MODE,
 286                                         ((xbin - 1) << 4) | (xskip - 1));
 287                 if (ret >= 0)
 288                         ret = reg_write(client, MT9T031_ROW_ADDRESS_MODE,
 289                                         ((ybin - 1) << 4) | (yskip - 1));
 290         }
 291         dev_dbg(&client->dev, "new physical left %u, top %u\n",
 292                 rect->left, rect->top);
 293
 294         /* The caller provides a supported format, as guaranteed by
 295          * icd->try_fmt_cap(), soc_camera_s_crop() and soc_camera_cropcap() */
 296         if (ret >= 0)
 297                 ret = reg_write(client, MT9T031_COLUMN_START, rect->left);
 298         if (ret >= 0)
 299                 ret = reg_write(client, MT9T031_ROW_START, rect->top);
 300         if (ret >= 0)
 301                 ret = reg_write(client, MT9T031_WINDOW_WIDTH, rect->width - 1);
 302         if (ret >= 0)
 303                 ret = reg_write(client, MT9T031_WINDOW_HEIGHT,
 304                                 rect->height + icd->y_skip_top - 1);
 305         if (ret >= 0 && mt9t031->autoexposure) {
 306                 unsigned int total_h = rect->height + icd->y_skip_top + vblank;
 307                 ret = set_shutter(client, total_h);
 308                 if (ret >= 0) {
 309                         const u32 shutter_max = MT9T031_MAX_HEIGHT + vblank;
 310                         const struct v4l2_queryctrl *qctrl =
 311                                 soc_camera_find_qctrl(icd->ops,
 312                                                       V4L2_CID_EXPOSURE);
 313                         mt9t031->exposure = (shutter_max / 2 + (total_h - 1) *
 314                                  (qctrl->maximum - qctrl->minimum)) /
 315                                 shutter_max + qctrl->minimum;
 316                 }
 317         }
 318
 319         /* Re-enable register update, commit all changes */
 320         if (ret >= 0)
 321                 ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 1);
 322
 323         if (ret >= 0) {
 324                 mt9t031->rect = *rect;
 325                 mt9t031->xskip = xskip;
 326                 mt9t031->yskip = yskip;
 327         }
 328
 329         return ret < 0 ? ret : 0;
 330 }
 331
 332 static int mt9t031_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
 333 {
 334         struct v4l2_rect rect = a->c;
 335         struct i2c_client *client = sd->priv;
 336         struct mt9t031 *mt9t031 = to_mt9t031(client);
 337         struct soc_camera_device *icd = client->dev.platform_data;
 338
 339         rect.width = ALIGN(rect.width, 2);
 340         rect.height = ALIGN(rect.height, 2);
 341
 342         soc_camera_limit_side(&rect.left, &rect.width,
 343                      MT9T031_COLUMN_SKIP, MT9T031_MIN_WIDTH, MT9T031_MAX_WIDTH);
 344
 345         soc_camera_limit_side(&rect.top, &rect.height,
 346                      MT9T031_ROW_SKIP, MT9T031_MIN_HEIGHT, MT9T031_MAX_HEIGHT);
 347
 348         return mt9t031_set_params(icd, &rect, mt9t031->xskip, mt9t031->yskip);
 349 }
 350
 351 static int mt9t031_g_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
 352 {
 353         struct i2c_client *client = sd->priv;
 354         struct mt9t031 *mt9t031 = to_mt9t031(client);
 355
 356         a->c    = mt9t031->rect;
 357         a->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 358
 359         return 0;
 360 }
 361
 362 static int mt9t031_cropcap(struct v4l2_subdev *sd, struct v4l2_cropcap *a)
 363 {
 364         a->bounds.left                  = MT9T031_COLUMN_SKIP;
 365         a->bounds.top                   = MT9T031_ROW_SKIP;
 366         a->bounds.width                 = MT9T031_MAX_WIDTH;
 367         a->bounds.height                = MT9T031_MAX_HEIGHT;
 368         a->defrect                      = a->bounds;
 369         a->type                         = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 370         a->pixelaspect.numerator        = 1;
 371         a->pixelaspect.denominator      = 1;
 372
 373         return 0;
 374 }
 375
 376 static int mt9t031_g_fmt(struct v4l2_subdev *sd, struct v4l2_format *f)
 377 {
 378         struct i2c_client *client = sd->priv;
 379         struct mt9t031 *mt9t031 = to_mt9t031(client);
 380         struct v4l2_pix_format *pix = &f->fmt.pix;
 381
 382         pix->width              = mt9t031->rect.width / mt9t031->xskip;
 383         pix->height             = mt9t031->rect.height / mt9t031->yskip;
 384         pix->pixelformat        = V4L2_PIX_FMT_SGRBG10;
 385         pix->field              = V4L2_FIELD_NONE;
 386         pix->colorspace         = V4L2_COLORSPACE_SRGB;
 387
 388         return 0;
 389 }
 390
 391 static int mt9t031_s_fmt(struct v4l2_subdev *sd, struct v4l2_format *f)
 392 {
 393         struct i2c_client *client = sd->priv;
 394         struct mt9t031 *mt9t031 = to_mt9t031(client);
 395         struct soc_camera_device *icd = client->dev.platform_data;
 396         struct v4l2_pix_format *pix = &f->fmt.pix;
 397         u16 xskip, yskip;
 398         struct v4l2_rect rect = mt9t031->rect;
 399
 400         /*
 401          * try_fmt has put width and height within limits.
 402          * S_FMT: use binning and skipping for scaling
 403          */
 404         xskip = mt9t031_skip(&rect.width, pix->width, MT9T031_MAX_WIDTH);
 405         yskip = mt9t031_skip(&rect.height, pix->height, MT9T031_MAX_HEIGHT);
 406
 407         /* mt9t031_set_params() doesn't change width and height */
 408         return mt9t031_set_params(icd, &rect, xskip, yskip);
 409 }
 410
 411 /*
 412  * If a user window larger than sensor window is requested, we'll increase the
 413  * sensor window.
 414  */
 415 static int mt9t031_try_fmt(struct v4l2_subdev *sd, struct v4l2_format *f)
 416 {
 417         struct v4l2_pix_format *pix = &f->fmt.pix;
 418
 419         v4l_bound_align_image(
 420                 &pix->width, MT9T031_MIN_WIDTH, MT9T031_MAX_WIDTH, 1,
 421                 &pix->height, MT9T031_MIN_HEIGHT, MT9T031_MAX_HEIGHT, 1, 0);
 422
 423         return 0;
 424 }
 425
 426 static int mt9t031_g_chip_ident(struct v4l2_subdev *sd,
 427                                 struct v4l2_dbg_chip_ident *id)
 428 {
 429         struct i2c_client *client = sd->priv;
 430         struct mt9t031 *mt9t031 = to_mt9t031(client);
 431
 432         if (id->match.type != V4L2_CHIP_MATCH_I2C_ADDR)
 433                 return -EINVAL;
 434
 435         if (id->match.addr != client->addr)
 436                 return -ENODEV;
 437
 438         id->ident       = mt9t031->model;
 439         id->revision    = 0;
 440
 441         return 0;
 442 }
 443
 444 #ifdef CONFIG_VIDEO_ADV_DEBUG
 445 static int mt9t031_g_register(struct v4l2_subdev *sd,
 446                               struct v4l2_dbg_register *reg)
 447 {
 448         struct i2c_client *client = sd->priv;
 449
 450         if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
 451                 return -EINVAL;
 452
 453         if (reg->match.addr != client->addr)
 454                 return -ENODEV;
 455
 456         reg->val = reg_read(client, reg->reg);
 457
 458         if (reg->val > 0xffff)
 459                 return -EIO;
 460
 461         return 0;
 462 }
 463
 464 static int mt9t031_s_register(struct v4l2_subdev *sd,
 465                               struct v4l2_dbg_register *reg)
 466 {
 467         struct i2c_client *client = sd->priv;
 468
 469         if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
 470                 return -EINVAL;
 471
 472         if (reg->match.addr != client->addr)
 473                 return -ENODEV;
 474
 475         if (reg_write(client, reg->reg, reg->val) < 0)
 476                 return -EIO;
 477
 478         return 0;
 479 }
 480 #endif
 481
 482 static const struct v4l2_queryctrl mt9t031_controls[] = {
 483         {
 484                 .id             = V4L2_CID_VFLIP,
 485                 .type           = V4L2_CTRL_TYPE_BOOLEAN,
 486                 .name           = "Flip Vertically",
 487                 .minimum        = 0,
 488                 .maximum        = 1,
 489                 .step           = 1,
 490                 .default_value  = 0,
 491         }, {
 492                 .id             = V4L2_CID_HFLIP,
 493                 .type           = V4L2_CTRL_TYPE_BOOLEAN,
 494                 .name           = "Flip Horizontally",
 495                 .minimum        = 0,
 496                 .maximum        = 1,
 497                 .step           = 1,
 498                 .default_value  = 0,
 499         }, {
 500                 .id             = V4L2_CID_GAIN,
 501                 .type           = V4L2_CTRL_TYPE_INTEGER,
 502                 .name           = "Gain",
 503                 .minimum        = 0,
 504                 .maximum        = 127,
 505                 .step           = 1,
 506                 .default_value  = 64,
 507                 .flags          = V4L2_CTRL_FLAG_SLIDER,
 508         }, {
 509                 .id             = V4L2_CID_EXPOSURE,
 510                 .type           = V4L2_CTRL_TYPE_INTEGER,
 511                 .name           = "Exposure",
 512                 .minimum        = 1,
 513                 .maximum        = 255,
 514                 .step           = 1,
 515                 .default_value  = 255,
 516                 .flags          = V4L2_CTRL_FLAG_SLIDER,
 517         }, {
 518                 .id             = V4L2_CID_EXPOSURE_AUTO,
 519                 .type           = V4L2_CTRL_TYPE_BOOLEAN,
 520                 .name           = "Automatic Exposure",
 521                 .minimum        = 0,
 522                 .maximum        = 1,
 523                 .step           = 1,
 524                 .default_value  = 1,
 525         }
 526 };
 527
 528 static struct soc_camera_ops mt9t031_ops = {
 529         .set_bus_param          = mt9t031_set_bus_param,
 530         .query_bus_param        = mt9t031_query_bus_param,
 531         .controls               = mt9t031_controls,
 532         .num_controls           = ARRAY_SIZE(mt9t031_controls),
 533 };
 534
 535 static int mt9t031_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
 536 {
 537         struct i2c_client *client = sd->priv;
 538         struct mt9t031 *mt9t031 = to_mt9t031(client);
 539         int data;
 540
 541         switch (ctrl->id) {
 542         case V4L2_CID_VFLIP:
 543                 data = reg_read(client, MT9T031_READ_MODE_2);
 544                 if (data < 0)
 545                         return -EIO;
 546                 ctrl->value = !!(data & 0x8000);
 547                 break;
 548         case V4L2_CID_HFLIP:
 549                 data = reg_read(client, MT9T031_READ_MODE_2);
 550                 if (data < 0)
 551                         return -EIO;
 552                 ctrl->value = !!(data & 0x4000);
 553                 break;
 554         case V4L2_CID_EXPOSURE_AUTO:
 555                 ctrl->value = mt9t031->autoexposure;
 556                 break;
 557         case V4L2_CID_GAIN:
 558                 ctrl->value = mt9t031->gain;
 559                 break;
 560         case V4L2_CID_EXPOSURE:
 561                 ctrl->value = mt9t031->exposure;
 562                 break;
 563         }
 564         return 0;
 565 }
 566
 567 static int mt9t031_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
 568 {
 569         struct i2c_client *client = sd->priv;
 570         struct mt9t031 *mt9t031 = to_mt9t031(client);
 571         struct soc_camera_device *icd = client->dev.platform_data;
 572         const struct v4l2_queryctrl *qctrl;
 573         int data;
 574
 575         qctrl = soc_camera_find_qctrl(&mt9t031_ops, ctrl->id);
 576
 577         if (!qctrl)
 578                 return -EINVAL;
 579
 580         switch (ctrl->id) {
 581         case V4L2_CID_VFLIP:
 582                 if (ctrl->value)
 583                         data = reg_set(client, MT9T031_READ_MODE_2, 0x8000);
 584                 else
 585                         data = reg_clear(client, MT9T031_READ_MODE_2, 0x8000);
 586                 if (data < 0)
 587                         return -EIO;
 588                 break;
 589         case V4L2_CID_HFLIP:
 590                 if (ctrl->value)
 591                         data = reg_set(client, MT9T031_READ_MODE_2, 0x4000);
 592                 else
 593                         data = reg_clear(client, MT9T031_READ_MODE_2, 0x4000);
 594                 if (data < 0)
 595                         return -EIO;
 596                 break;
 597         case V4L2_CID_GAIN:
 598                 if (ctrl->value > qctrl->maximum || ctrl->value < qctrl->minimum)
 599                         return -EINVAL;
 600                 /* See Datasheet Table 7, Gain settings. */
 601                 if (ctrl->value <= qctrl->default_value) {
 602                         /* Pack it into 0..1 step 0.125, register values 0..8 */
 603                         unsigned long range = qctrl->default_value - qctrl->minimum;
 604                         data = ((ctrl->value - qctrl->minimum) * 8 + range / 2) / range;
 605
 606                         dev_dbg(&client->dev, "Setting gain %d\n", data);
 607                         data = reg_write(client, MT9T031_GLOBAL_GAIN, data);
 608                         if (data < 0)
 609                                 return -EIO;
 610                 } else {
 611                         /* Pack it into 1.125..128 variable step, register values 9..0x7860 */
 612                         /* We assume qctrl->maximum - qctrl->default_value - 1 > 0 */
 613                         unsigned long range = qctrl->maximum - qctrl->default_value - 1;
 614                         /* calculated gain: map 65..127 to 9..1024 step 0.125 */
 615                         unsigned long gain = ((ctrl->value - qctrl->default_value - 1) *
 616                                                1015 + range / 2) / range + 9;
 617
 618                         if (gain <= 32)         /* calculated gain 9..32 -> 9..32 */
 619                                 data = gain;
 620                         else if (gain <= 64)    /* calculated gain 33..64 -> 0x51..0x60 */
 621                                 data = ((gain - 32) * 16 + 16) / 32 + 80;
 622                         else
 623                                 /* calculated gain 65..1024 -> (1..120) << 8 + 0x60 */
 624                                 data = (((gain - 64 + 7) * 32) & 0xff00) | 0x60;
 625
 626                         dev_dbg(&client->dev, "Set gain from 0x%x to 0x%x\n",
 627                                 reg_read(client, MT9T031_GLOBAL_GAIN), data);
 628                         data = reg_write(client, MT9T031_GLOBAL_GAIN, data);
 629                         if (data < 0)
 630                                 return -EIO;
 631                 }
 632
 633                 /* Success */
 634                 mt9t031->gain = ctrl->value;
 635                 break;
 636         case V4L2_CID_EXPOSURE:
 637                 /* mt9t031 has maximum == default */
 638                 if (ctrl->value > qctrl->maximum || ctrl->value < qctrl->minimum)
 639                         return -EINVAL;
 640                 else {
 641                         const unsigned long range = qctrl->maximum - qctrl->minimum;
 642                         const u32 shutter = ((ctrl->value - qctrl->minimum) * 1048 +
 643                                              range / 2) / range + 1;
 644                         u32 old;
 645
 646                         get_shutter(client, &old);
 647                         dev_dbg(&client->dev, "Set shutter from %u to %u\n",
 648                                 old, shutter);
 649                         if (set_shutter(client, shutter) < 0)
 650                                 return -EIO;
 651                         mt9t031->exposure = ctrl->value;
 652                         mt9t031->autoexposure = 0;
 653                 }
 654                 break;
 655         case V4L2_CID_EXPOSURE_AUTO:
 656                 if (ctrl->value) {
 657                         const u16 vblank = MT9T031_VERTICAL_BLANK;
 658                         const u32 shutter_max = MT9T031_MAX_HEIGHT + vblank;
 659                         unsigned int total_h = mt9t031->rect.height +
 660                                 icd->y_skip_top + vblank;
 661
 662                         if (set_shutter(client, total_h) < 0)
 663                                 return -EIO;
 664                         qctrl = soc_camera_find_qctrl(icd->ops, V4L2_CID_EXPOSURE);
 665                         mt9t031->exposure = (shutter_max / 2 + (total_h - 1) *
 666                                  (qctrl->maximum - qctrl->minimum)) /
 667                                 shutter_max + qctrl->minimum;
 668                         mt9t031->autoexposure = 1;
 669                 } else
 670                         mt9t031->autoexposure = 0;
 671                 break;
 672         }
 673         return 0;
 674 }
 675
 676 /* Interface active, can use i2c. If it fails, it can indeed mean, that
 677  * this wasn't our capture interface, so, we wait for the right one */
 678 static int mt9t031_video_probe(struct i2c_client *client)
 679 {
 680         struct soc_camera_device *icd = client->dev.platform_data;
 681         struct mt9t031 *mt9t031 = to_mt9t031(client);
 682         s32 data;
 683         int ret;
 684
 685         /* Enable the chip */
 686         data = reg_write(client, MT9T031_CHIP_ENABLE, 1);
 687         dev_dbg(&client->dev, "write: %d\n", data);
 688
 689         /* Read out the chip version register */
 690         data = reg_read(client, MT9T031_CHIP_VERSION);
 691
 692         switch (data) {
 693         case 0x1621:
 694                 mt9t031->model = V4L2_IDENT_MT9T031;
 695                 icd->formats = mt9t031_colour_formats;
 696                 icd->num_formats = ARRAY_SIZE(mt9t031_colour_formats);
 697                 break;
 698         default:
 699                 dev_err(&client->dev,
 700                         "No MT9T031 chip detected, register read %x\n", data);
 701                 return -ENODEV;
 702         }
 703
 704         dev_info(&client->dev, "Detected a MT9T031 chip ID %x\n", data);
 705
 706         ret = mt9t031_idle(client);
 707         if (ret < 0)
 708                 dev_err(&client->dev, "Failed to initialise the camera\n");
 709
 710         /* mt9t031_idle() has reset the chip to default. */
 711         mt9t031->exposure = 255;
 712         mt9t031->gain = 64;
 713
 714         return ret;
 715 }
 716
 717 static struct v4l2_subdev_core_ops mt9t031_subdev_core_ops = {
 718         .g_ctrl         = mt9t031_g_ctrl,
 719         .s_ctrl         = mt9t031_s_ctrl,
 720         .g_chip_ident   = mt9t031_g_chip_ident,
 721 #ifdef CONFIG_VIDEO_ADV_DEBUG
 722         .g_register     = mt9t031_g_register,
 723         .s_register     = mt9t031_s_register,
 724 #endif
 725 };
 726
 727 static struct v4l2_subdev_video_ops mt9t031_subdev_video_ops = {
 728         .s_stream       = mt9t031_s_stream,
 729         .s_fmt          = mt9t031_s_fmt,
 730         .g_fmt          = mt9t031_g_fmt,
 731         .try_fmt        = mt9t031_try_fmt,
 732         .s_crop         = mt9t031_s_crop,
 733         .g_crop         = mt9t031_g_crop,
 734         .cropcap        = mt9t031_cropcap,
 735 };
 736
 737 static struct v4l2_subdev_ops mt9t031_subdev_ops = {
 738         .core   = &mt9t031_subdev_core_ops,
 739         .video  = &mt9t031_subdev_video_ops,
 740 };
 741
 742 static int mt9t031_probe(struct i2c_client *client,
 743                          const struct i2c_device_id *did)
 744 {
 745         struct mt9t031 *mt9t031;
 746         struct soc_camera_device *icd = client->dev.platform_data;
 747         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 748         struct soc_camera_link *icl;
 749         int ret;
 750
 751         if (!icd) {
 752                 dev_err(&client->dev, "MT9T031: missing soc-camera data!\n");
 753                 return -EINVAL;
 754         }
 755
 756         icl = to_soc_camera_link(icd);
 757         if (!icl) {
 758                 dev_err(&client->dev, "MT9T031 driver needs platform data\n");
 759                 return -EINVAL;
 760         }
 761
 762         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
 763                 dev_warn(&adapter->dev,
 764                          "I2C-Adapter doesn't support I2C_FUNC_SMBUS_WORD\n");
 765                 return -EIO;
 766         }
 767
 768         mt9t031 = kzalloc(sizeof(struct mt9t031), GFP_KERNEL);
 769         if (!mt9t031)
 770                 return -ENOMEM;
 771
 772         v4l2_i2c_subdev_init(&mt9t031->subdev, client, &mt9t031_subdev_ops);
 773
 774         /* Second stage probe - when a capture adapter is there */
 775         icd->ops                = &mt9t031_ops;
 776         icd->y_skip_top         = 0;
 777
 778         mt9t031->rect.left      = MT9T031_COLUMN_SKIP;
 779         mt9t031->rect.top       = MT9T031_ROW_SKIP;
 780         mt9t031->rect.width     = MT9T031_MAX_WIDTH;
 781         mt9t031->rect.height    = MT9T031_MAX_HEIGHT;
 782
 783         /* Simulated autoexposure. If enabled, we calculate shutter width
 784          * ourselves in the driver based on vertical blanking and frame width */
 785         mt9t031->autoexposure = 1;
 786
 787         mt9t031->xskip = 1;
 788         mt9t031->yskip = 1;
 789
 790         mt9t031_idle(client);
 791
 792         ret = mt9t031_video_probe(client);
 793
 794         mt9t031_disable(client);
 795
 796         if (ret) {
 797                 icd->ops = NULL;
 798                 i2c_set_clientdata(client, NULL);
 799                 kfree(mt9t031);
 800         }
 801
 802         return ret;
 803 }
 804
 805 static int mt9t031_remove(struct i2c_client *client)
 806 {
 807         struct mt9t031 *mt9t031 = to_mt9t031(client);
 808         struct soc_camera_device *icd = client->dev.platform_data;
 809
 810         icd->ops = NULL;
 811         i2c_set_clientdata(client, NULL);
 812         client->driver = NULL;
 813         kfree(mt9t031);
 814
 815         return 0;
 816 }
 817
 818 static const struct i2c_device_id mt9t031_id[] = {
 819         { "mt9t031", 0 },
 820         { }
 821 };
 822 MODULE_DEVICE_TABLE(i2c, mt9t031_id);
 823
 824 static struct i2c_driver mt9t031_i2c_driver = {
 825         .driver = {
 826                 .name = "mt9t031",
 827         },
 828         .probe          = mt9t031_probe,
 829         .remove         = mt9t031_remove,
 830         .id_table       = mt9t031_id,
 831 };
 832
 833 static int __init mt9t031_mod_init(void)
 834 {
 835         return i2c_add_driver(&mt9t031_i2c_driver);
 836 }
 837
 838 static void __exit mt9t031_mod_exit(void)
 839 {
 840         i2c_del_driver(&mt9t031_i2c_driver);
 841 }
 842
 843 module_init(mt9t031_mod_init);
 844 module_exit(mt9t031_mod_exit);
 845
 846 MODULE_DESCRIPTION("Micron MT9T031 Camera driver");
 847 MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
 848 MODULE_LICENSE("GPL v2");