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               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 v4l2_subdev subdev;
  72         int model;      /* V4L2_IDENT_MT9T031* codes from v4l2-chip-ident.h */
  73         unsigned char autoexposure;
  74         u16 xskip;
  75         u16 yskip;
  76 };
  77
  78 static struct mt9t031 *to_mt9t031(const struct i2c_client *client)
  79 {
  80         return container_of(i2c_get_clientdata(client), struct mt9t031, subdev);
  81 }
  82
  83 static int reg_read(struct i2c_client *client, const u8 reg)
  84 {
  85         s32 data = i2c_smbus_read_word_data(client, reg);
  86         return data < 0 ? data : swab16(data);
  87 }
  88
  89 static int reg_write(struct i2c_client *client, const u8 reg,
  90                      const u16 data)
  91 {
  92         return i2c_smbus_write_word_data(client, reg, swab16(data));
  93 }
  94
  95 static int reg_set(struct i2c_client *client, const u8 reg,
  96                    const u16 data)
  97 {
  98         int ret;
  99
 100         ret = reg_read(client, reg);
 101         if (ret < 0)
 102                 return ret;
 103         return reg_write(client, reg, ret | data);
 104 }
 105
 106 static int reg_clear(struct i2c_client *client, const u8 reg,
 107                      const u16 data)
 108 {
 109         int ret;
 110
 111         ret = reg_read(client, reg);
 112         if (ret < 0)
 113                 return ret;
 114         return reg_write(client, reg, ret & ~data);
 115 }
 116
 117 static int set_shutter(struct i2c_client *client, const u32 data)
 118 {
 119         int ret;
 120
 121         ret = reg_write(client, MT9T031_SHUTTER_WIDTH_UPPER, data >> 16);
 122
 123         if (ret >= 0)
 124                 ret = reg_write(client, MT9T031_SHUTTER_WIDTH, data & 0xffff);
 125
 126         return ret;
 127 }
 128
 129 static int get_shutter(struct i2c_client *client, u32 *data)
 130 {
 131         int ret;
 132
 133         ret = reg_read(client, MT9T031_SHUTTER_WIDTH_UPPER);
 134         *data = ret << 16;
 135
 136         if (ret >= 0)
 137                 ret = reg_read(client, MT9T031_SHUTTER_WIDTH);
 138         *data |= ret & 0xffff;
 139
 140         return ret < 0 ? ret : 0;
 141 }
 142
 143 static int mt9t031_idle(struct i2c_client *client)
 144 {
 145         int ret;
 146
 147         /* Disable chip output, synchronous option update */
 148         ret = reg_write(client, MT9T031_RESET, 1);
 149         if (ret >= 0)
 150                 ret = reg_write(client, MT9T031_RESET, 0);
 151         if (ret >= 0)
 152                 ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
 153
 154         return ret >= 0 ? 0 : -EIO;
 155 }
 156
 157 static int mt9t031_disable(struct i2c_client *client)
 158 {
 159         /* Disable the chip */
 160         reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
 161
 162         return 0;
 163 }
 164
 165 static int mt9t031_init(struct soc_camera_device *icd)
 166 {
 167         struct i2c_client *client = to_i2c_client(to_soc_camera_control(icd));
 168
 169         return mt9t031_idle(client);
 170 }
 171
 172 static int mt9t031_release(struct soc_camera_device *icd)
 173 {
 174         struct i2c_client *client = to_i2c_client(to_soc_camera_control(icd));
 175
 176         return mt9t031_disable(client);
 177 }
 178
 179 static int mt9t031_s_stream(struct v4l2_subdev *sd, int enable)
 180 {
 181         struct i2c_client *client = sd->priv;
 182         int ret;
 183
 184         if (enable)
 185                 /* Switch to master "normal" mode */
 186                 ret = reg_set(client, MT9T031_OUTPUT_CONTROL, 2);
 187         else
 188                 /* Stop sensor readout */
 189                 ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
 190
 191         if (ret < 0)
 192                 return -EIO;
 193
 194         return 0;
 195 }
 196
 197 static int mt9t031_set_bus_param(struct soc_camera_device *icd,
 198                                  unsigned long flags)
 199 {
 200         struct i2c_client *client = to_i2c_client(to_soc_camera_control(icd));
 201
 202         /* The caller should have queried our parameters, check anyway */
 203         if (flags & ~MT9T031_BUS_PARAM)
 204                 return -EINVAL;
 205
 206         if (flags & SOCAM_PCLK_SAMPLE_FALLING)
 207                 reg_clear(client, MT9T031_PIXEL_CLOCK_CONTROL, 0x8000);
 208         else
 209                 reg_set(client, MT9T031_PIXEL_CLOCK_CONTROL, 0x8000);
 210
 211         return 0;
 212 }
 213
 214 static unsigned long mt9t031_query_bus_param(struct soc_camera_device *icd)
 215 {
 216         struct soc_camera_link *icl = to_soc_camera_link(icd);
 217
 218         return soc_camera_apply_sensor_flags(icl, MT9T031_BUS_PARAM);
 219 }
 220
 221 /* Round up minima and round down maxima */
 222 static void recalculate_limits(struct soc_camera_device *icd,
 223                                u16 xskip, u16 yskip)
 224 {
 225         icd->rect_max.left = (MT9T031_COLUMN_SKIP + xskip - 1) / xskip;
 226         icd->rect_max.top = (MT9T031_ROW_SKIP + yskip - 1) / yskip;
 227         icd->width_min = (MT9T031_MIN_WIDTH + xskip - 1) / xskip;
 228         icd->height_min = (MT9T031_MIN_HEIGHT + yskip - 1) / yskip;
 229         icd->rect_max.width = MT9T031_MAX_WIDTH / xskip;
 230         icd->rect_max.height = MT9T031_MAX_HEIGHT / yskip;
 231 }
 232
 233 static int mt9t031_set_params(struct soc_camera_device *icd,
 234                               struct v4l2_rect *rect, u16 xskip, u16 yskip)
 235 {
 236         struct i2c_client *client = to_i2c_client(to_soc_camera_control(icd));
 237         struct mt9t031 *mt9t031 = to_mt9t031(client);
 238         int ret;
 239         u16 xbin, ybin, width, height, left, top;
 240         const u16 hblank = MT9T031_HORIZONTAL_BLANK,
 241                 vblank = MT9T031_VERTICAL_BLANK;
 242
 243         width = rect->width * xskip;
 244         height = rect->height * yskip;
 245         left = rect->left * xskip;
 246         top = rect->top * yskip;
 247
 248         xbin = min(xskip, (u16)3);
 249         ybin = min(yskip, (u16)3);
 250
 251         dev_dbg(&icd->dev, "xskip %u, width %u/%u, yskip %u, height %u/%u\n",
 252                 xskip, width, rect->width, yskip, height, rect->height);
 253
 254         /* Could just do roundup(rect->left, [xy]bin * 2); but this is cheaper */
 255         switch (xbin) {
 256         case 2:
 257                 left = (left + 3) & ~3;
 258                 break;
 259         case 3:
 260                 left = roundup(left, 6);
 261         }
 262
 263         switch (ybin) {
 264         case 2:
 265                 top = (top + 3) & ~3;
 266                 break;
 267         case 3:
 268                 top = roundup(top, 6);
 269         }
 270
 271         /* Disable register update, reconfigure atomically */
 272         ret = reg_set(client, MT9T031_OUTPUT_CONTROL, 1);
 273         if (ret < 0)
 274                 return ret;
 275
 276         /* Blanking and start values - default... */
 277         ret = reg_write(client, MT9T031_HORIZONTAL_BLANKING, hblank);
 278         if (ret >= 0)
 279                 ret = reg_write(client, MT9T031_VERTICAL_BLANKING, vblank);
 280
 281         if (yskip != mt9t031->yskip || xskip != mt9t031->xskip) {
 282                 /* Binning, skipping */
 283                 if (ret >= 0)
 284                         ret = reg_write(client, MT9T031_COLUMN_ADDRESS_MODE,
 285                                         ((xbin - 1) << 4) | (xskip - 1));
 286                 if (ret >= 0)
 287                         ret = reg_write(client, MT9T031_ROW_ADDRESS_MODE,
 288                                         ((ybin - 1) << 4) | (yskip - 1));
 289         }
 290         dev_dbg(&icd->dev, "new physical left %u, top %u\n", left, top);
 291
 292         /* The caller provides a supported format, as guaranteed by
 293          * icd->try_fmt_cap(), soc_camera_s_crop() and soc_camera_cropcap() */
 294         if (ret >= 0)
 295                 ret = reg_write(client, MT9T031_COLUMN_START, left);
 296         if (ret >= 0)
 297                 ret = reg_write(client, MT9T031_ROW_START, top);
 298         if (ret >= 0)
 299                 ret = reg_write(client, MT9T031_WINDOW_WIDTH, width - 1);
 300         if (ret >= 0)
 301                 ret = reg_write(client, MT9T031_WINDOW_HEIGHT,
 302                                 height + icd->y_skip_top - 1);
 303         if (ret >= 0 && mt9t031->autoexposure) {
 304                 ret = set_shutter(client, height + icd->y_skip_top + vblank);
 305                 if (ret >= 0) {
 306                         const u32 shutter_max = MT9T031_MAX_HEIGHT + vblank;
 307                         const struct v4l2_queryctrl *qctrl =
 308                                 soc_camera_find_qctrl(icd->ops,
 309                                                       V4L2_CID_EXPOSURE);
 310                         icd->exposure = (shutter_max / 2 + (height +
 311                                          icd->y_skip_top + vblank - 1) *
 312                                          (qctrl->maximum - qctrl->minimum)) /
 313                                 shutter_max + qctrl->minimum;
 314                 }
 315         }
 316
 317         /* Re-enable register update, commit all changes */
 318         if (ret >= 0)
 319                 ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 1);
 320
 321         return ret < 0 ? ret : 0;
 322 }
 323
 324 static int mt9t031_set_crop(struct soc_camera_device *icd,
 325                             struct v4l2_rect *rect)
 326 {
 327         struct i2c_client *client = to_i2c_client(to_soc_camera_control(icd));
 328         struct mt9t031 *mt9t031 = to_mt9t031(client);
 329
 330         /* Make sure we don't exceed sensor limits */
 331         if (rect->left + rect->width > icd->rect_max.left + icd->rect_max.width)
 332                 rect->left = icd->rect_max.width + icd->rect_max.left -
 333                         rect->width;
 334
 335         if (rect->top + rect->height > icd->rect_max.height + icd->rect_max.top)
 336                 rect->top = icd->rect_max.height + icd->rect_max.top -
 337                         rect->height;
 338
 339         /* CROP - no change in scaling, or in limits */
 340         return mt9t031_set_params(icd, rect, mt9t031->xskip, mt9t031->yskip);
 341 }
 342
 343 static int mt9t031_s_fmt(struct v4l2_subdev *sd, struct v4l2_format *f)
 344 {
 345         struct i2c_client *client = sd->priv;
 346         struct mt9t031 *mt9t031 = to_mt9t031(client);
 347         struct soc_camera_device *icd = client->dev.platform_data;
 348         int ret;
 349         u16 xskip, yskip;
 350         struct v4l2_rect rect = {
 351                 .left   = icd->rect_current.left,
 352                 .top    = icd->rect_current.top,
 353                 .width  = f->fmt.pix.width,
 354                 .height = f->fmt.pix.height,
 355         };
 356
 357         /*
 358          * try_fmt has put rectangle within limits.
 359          * S_FMT - use binning and skipping for scaling, recalculate
 360          * limits, used for cropping
 361          */
 362         /* Is this more optimal than just a division? */
 363         for (xskip = 8; xskip > 1; xskip--)
 364                 if (rect.width * xskip <= MT9T031_MAX_WIDTH)
 365                         break;
 366
 367         for (yskip = 8; yskip > 1; yskip--)
 368                 if (rect.height * yskip <= MT9T031_MAX_HEIGHT)
 369                         break;
 370
 371         recalculate_limits(icd, xskip, yskip);
 372
 373         ret = mt9t031_set_params(icd, &rect, xskip, yskip);
 374         if (!ret) {
 375                 mt9t031->xskip = xskip;
 376                 mt9t031->yskip = yskip;
 377         }
 378
 379         return ret;
 380 }
 381
 382 static int mt9t031_try_fmt(struct v4l2_subdev *sd, struct v4l2_format *f)
 383 {
 384         struct v4l2_pix_format *pix = &f->fmt.pix;
 385
 386         v4l_bound_align_image(
 387                 &pix->width, MT9T031_MIN_WIDTH, MT9T031_MAX_WIDTH, 1,
 388                 &pix->height, MT9T031_MIN_HEIGHT, MT9T031_MAX_HEIGHT, 1, 0);
 389
 390         return 0;
 391 }
 392
 393 static int mt9t031_g_chip_ident(struct v4l2_subdev *sd,
 394                                 struct v4l2_dbg_chip_ident *id)
 395 {
 396         struct i2c_client *client = sd->priv;
 397         struct mt9t031 *mt9t031 = to_mt9t031(client);
 398
 399         if (id->match.type != V4L2_CHIP_MATCH_I2C_ADDR)
 400                 return -EINVAL;
 401
 402         if (id->match.addr != client->addr)
 403                 return -ENODEV;
 404
 405         id->ident       = mt9t031->model;
 406         id->revision    = 0;
 407
 408         return 0;
 409 }
 410
 411 #ifdef CONFIG_VIDEO_ADV_DEBUG
 412 static int mt9t031_g_register(struct v4l2_subdev *sd,
 413                               struct v4l2_dbg_register *reg)
 414 {
 415         struct i2c_client *client = sd->priv;
 416
 417         if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
 418                 return -EINVAL;
 419
 420         if (reg->match.addr != client->addr)
 421                 return -ENODEV;
 422
 423         reg->val = reg_read(client, reg->reg);
 424
 425         if (reg->val > 0xffff)
 426                 return -EIO;
 427
 428         return 0;
 429 }
 430
 431 static int mt9t031_s_register(struct v4l2_subdev *sd,
 432                               struct v4l2_dbg_register *reg)
 433 {
 434         struct i2c_client *client = sd->priv;
 435
 436         if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
 437                 return -EINVAL;
 438
 439         if (reg->match.addr != client->addr)
 440                 return -ENODEV;
 441
 442         if (reg_write(client, reg->reg, reg->val) < 0)
 443                 return -EIO;
 444
 445         return 0;
 446 }
 447 #endif
 448
 449 static const struct v4l2_queryctrl mt9t031_controls[] = {
 450         {
 451                 .id             = V4L2_CID_VFLIP,
 452                 .type           = V4L2_CTRL_TYPE_BOOLEAN,
 453                 .name           = "Flip Vertically",
 454                 .minimum        = 0,
 455                 .maximum        = 1,
 456                 .step           = 1,
 457                 .default_value  = 0,
 458         }, {
 459                 .id             = V4L2_CID_HFLIP,
 460                 .type           = V4L2_CTRL_TYPE_BOOLEAN,
 461                 .name           = "Flip Horizontally",
 462                 .minimum        = 0,
 463                 .maximum        = 1,
 464                 .step           = 1,
 465                 .default_value  = 0,
 466         }, {
 467                 .id             = V4L2_CID_GAIN,
 468                 .type           = V4L2_CTRL_TYPE_INTEGER,
 469                 .name           = "Gain",
 470                 .minimum        = 0,
 471                 .maximum        = 127,
 472                 .step           = 1,
 473                 .default_value  = 64,
 474                 .flags          = V4L2_CTRL_FLAG_SLIDER,
 475         }, {
 476                 .id             = V4L2_CID_EXPOSURE,
 477                 .type           = V4L2_CTRL_TYPE_INTEGER,
 478                 .name           = "Exposure",
 479                 .minimum        = 1,
 480                 .maximum        = 255,
 481                 .step           = 1,
 482                 .default_value  = 255,
 483                 .flags          = V4L2_CTRL_FLAG_SLIDER,
 484         }, {
 485                 .id             = V4L2_CID_EXPOSURE_AUTO,
 486                 .type           = V4L2_CTRL_TYPE_BOOLEAN,
 487                 .name           = "Automatic Exposure",
 488                 .minimum        = 0,
 489                 .maximum        = 1,
 490                 .step           = 1,
 491                 .default_value  = 1,
 492         }
 493 };
 494
 495 static struct soc_camera_ops mt9t031_ops = {
 496         .init                   = mt9t031_init,
 497         .release                = mt9t031_release,
 498         .set_crop               = mt9t031_set_crop,
 499         .set_bus_param          = mt9t031_set_bus_param,
 500         .query_bus_param        = mt9t031_query_bus_param,
 501         .controls               = mt9t031_controls,
 502         .num_controls           = ARRAY_SIZE(mt9t031_controls),
 503 };
 504
 505 static int mt9t031_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
 506 {
 507         struct i2c_client *client = sd->priv;
 508         struct mt9t031 *mt9t031 = to_mt9t031(client);
 509         int data;
 510
 511         switch (ctrl->id) {
 512         case V4L2_CID_VFLIP:
 513                 data = reg_read(client, MT9T031_READ_MODE_2);
 514                 if (data < 0)
 515                         return -EIO;
 516                 ctrl->value = !!(data & 0x8000);
 517                 break;
 518         case V4L2_CID_HFLIP:
 519                 data = reg_read(client, MT9T031_READ_MODE_2);
 520                 if (data < 0)
 521                         return -EIO;
 522                 ctrl->value = !!(data & 0x4000);
 523                 break;
 524         case V4L2_CID_EXPOSURE_AUTO:
 525                 ctrl->value = mt9t031->autoexposure;
 526                 break;
 527         }
 528         return 0;
 529 }
 530
 531 static int mt9t031_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
 532 {
 533         struct i2c_client *client = sd->priv;
 534         struct mt9t031 *mt9t031 = to_mt9t031(client);
 535         struct soc_camera_device *icd = client->dev.platform_data;
 536         const struct v4l2_queryctrl *qctrl;
 537         int data;
 538
 539         qctrl = soc_camera_find_qctrl(&mt9t031_ops, ctrl->id);
 540
 541         if (!qctrl)
 542                 return -EINVAL;
 543
 544         switch (ctrl->id) {
 545         case V4L2_CID_VFLIP:
 546                 if (ctrl->value)
 547                         data = reg_set(client, MT9T031_READ_MODE_2, 0x8000);
 548                 else
 549                         data = reg_clear(client, MT9T031_READ_MODE_2, 0x8000);
 550                 if (data < 0)
 551                         return -EIO;
 552                 break;
 553         case V4L2_CID_HFLIP:
 554                 if (ctrl->value)
 555                         data = reg_set(client, MT9T031_READ_MODE_2, 0x4000);
 556                 else
 557                         data = reg_clear(client, MT9T031_READ_MODE_2, 0x4000);
 558                 if (data < 0)
 559                         return -EIO;
 560                 break;
 561         case V4L2_CID_GAIN:
 562                 if (ctrl->value > qctrl->maximum || ctrl->value < qctrl->minimum)
 563                         return -EINVAL;
 564                 /* See Datasheet Table 7, Gain settings. */
 565                 if (ctrl->value <= qctrl->default_value) {
 566                         /* Pack it into 0..1 step 0.125, register values 0..8 */
 567                         unsigned long range = qctrl->default_value - qctrl->minimum;
 568                         data = ((ctrl->value - qctrl->minimum) * 8 + range / 2) / range;
 569
 570                         dev_dbg(&icd->dev, "Setting gain %d\n", data);
 571                         data = reg_write(client, MT9T031_GLOBAL_GAIN, data);
 572                         if (data < 0)
 573                                 return -EIO;
 574                 } else {
 575                         /* Pack it into 1.125..128 variable step, register values 9..0x7860 */
 576                         /* We assume qctrl->maximum - qctrl->default_value - 1 > 0 */
 577                         unsigned long range = qctrl->maximum - qctrl->default_value - 1;
 578                         /* calculated gain: map 65..127 to 9..1024 step 0.125 */
 579                         unsigned long gain = ((ctrl->value - qctrl->default_value - 1) *
 580                                                1015 + range / 2) / range + 9;
 581
 582                         if (gain <= 32)         /* calculated gain 9..32 -> 9..32 */
 583                                 data = gain;
 584                         else if (gain <= 64)    /* calculated gain 33..64 -> 0x51..0x60 */
 585                                 data = ((gain - 32) * 16 + 16) / 32 + 80;
 586                         else
 587                                 /* calculated gain 65..1024 -> (1..120) << 8 + 0x60 */
 588                                 data = (((gain - 64 + 7) * 32) & 0xff00) | 0x60;
 589
 590                         dev_dbg(&icd->dev, "Setting gain from 0x%x to 0x%x\n",
 591                                 reg_read(client, MT9T031_GLOBAL_GAIN), data);
 592                         data = reg_write(client, MT9T031_GLOBAL_GAIN, data);
 593                         if (data < 0)
 594                                 return -EIO;
 595                 }
 596
 597                 /* Success */
 598                 icd->gain = ctrl->value;
 599                 break;
 600         case V4L2_CID_EXPOSURE:
 601                 /* mt9t031 has maximum == default */
 602                 if (ctrl->value > qctrl->maximum || ctrl->value < qctrl->minimum)
 603                         return -EINVAL;
 604                 else {
 605                         const unsigned long range = qctrl->maximum - qctrl->minimum;
 606                         const u32 shutter = ((ctrl->value - qctrl->minimum) * 1048 +
 607                                              range / 2) / range + 1;
 608                         u32 old;
 609
 610                         get_shutter(client, &old);
 611                         dev_dbg(&icd->dev, "Setting shutter width from %u to %u\n",
 612                                 old, shutter);
 613                         if (set_shutter(client, shutter) < 0)
 614                                 return -EIO;
 615                         icd->exposure = ctrl->value;
 616                         mt9t031->autoexposure = 0;
 617                 }
 618                 break;
 619         case V4L2_CID_EXPOSURE_AUTO:
 620                 if (ctrl->value) {
 621                         const u16 vblank = MT9T031_VERTICAL_BLANK;
 622                         const u32 shutter_max = MT9T031_MAX_HEIGHT + vblank;
 623                         if (set_shutter(client, icd->rect_current.height +
 624                                         icd->y_skip_top + vblank) < 0)
 625                                 return -EIO;
 626                         qctrl = soc_camera_find_qctrl(icd->ops, V4L2_CID_EXPOSURE);
 627                         icd->exposure = (shutter_max / 2 +
 628                                          (icd->rect_current.height +
 629                                           icd->y_skip_top + vblank - 1) *
 630                                          (qctrl->maximum - qctrl->minimum)) /
 631                                 shutter_max + qctrl->minimum;
 632                         mt9t031->autoexposure = 1;
 633                 } else
 634                         mt9t031->autoexposure = 0;
 635                 break;
 636         }
 637         return 0;
 638 }
 639
 640 /* Interface active, can use i2c. If it fails, it can indeed mean, that
 641  * this wasn't our capture interface, so, we wait for the right one */
 642 static int mt9t031_video_probe(struct i2c_client *client)
 643 {
 644         struct soc_camera_device *icd = client->dev.platform_data;
 645         struct mt9t031 *mt9t031 = to_mt9t031(client);
 646         s32 data;
 647
 648         /* We must have a parent by now. And it cannot be a wrong one.
 649          * So this entire test is completely redundant. */
 650         if (!icd->dev.parent ||
 651             to_soc_camera_host(icd->dev.parent)->nr != icd->iface)
 652                 return -ENODEV;
 653
 654         /* Enable the chip */
 655         data = reg_write(client, MT9T031_CHIP_ENABLE, 1);
 656         dev_dbg(&icd->dev, "write: %d\n", data);
 657
 658         /* Read out the chip version register */
 659         data = reg_read(client, MT9T031_CHIP_VERSION);
 660
 661         switch (data) {
 662         case 0x1621:
 663                 mt9t031->model = V4L2_IDENT_MT9T031;
 664                 icd->formats = mt9t031_colour_formats;
 665                 icd->num_formats = ARRAY_SIZE(mt9t031_colour_formats);
 666                 break;
 667         default:
 668                 dev_err(&icd->dev,
 669                         "No MT9T031 chip detected, register read %x\n", data);
 670                 return -ENODEV;
 671         }
 672
 673         dev_info(&icd->dev, "Detected a MT9T031 chip ID %x\n", data);
 674
 675         return 0;
 676 }
 677
 678 static struct v4l2_subdev_core_ops mt9t031_subdev_core_ops = {
 679         .g_ctrl         = mt9t031_g_ctrl,
 680         .s_ctrl         = mt9t031_s_ctrl,
 681         .g_chip_ident   = mt9t031_g_chip_ident,
 682 #ifdef CONFIG_VIDEO_ADV_DEBUG
 683         .g_register     = mt9t031_g_register,
 684         .s_register     = mt9t031_s_register,
 685 #endif
 686 };
 687
 688 static struct v4l2_subdev_video_ops mt9t031_subdev_video_ops = {
 689         .s_stream       = mt9t031_s_stream,
 690         .s_fmt          = mt9t031_s_fmt,
 691         .try_fmt        = mt9t031_try_fmt,
 692 };
 693
 694 static struct v4l2_subdev_ops mt9t031_subdev_ops = {
 695         .core   = &mt9t031_subdev_core_ops,
 696         .video  = &mt9t031_subdev_video_ops,
 697 };
 698
 699 static int mt9t031_probe(struct i2c_client *client,
 700                          const struct i2c_device_id *did)
 701 {
 702         struct mt9t031 *mt9t031;
 703         struct soc_camera_device *icd = client->dev.platform_data;
 704         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 705         struct soc_camera_link *icl;
 706         int ret;
 707
 708         if (!icd) {
 709                 dev_err(&client->dev, "MT9T031: missing soc-camera data!\n");
 710                 return -EINVAL;
 711         }
 712
 713         icl = to_soc_camera_link(icd);
 714         if (!icl) {
 715                 dev_err(&client->dev, "MT9T031 driver needs platform data\n");
 716                 return -EINVAL;
 717         }
 718
 719         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
 720                 dev_warn(&adapter->dev,
 721                          "I2C-Adapter doesn't support I2C_FUNC_SMBUS_WORD\n");
 722                 return -EIO;
 723         }
 724
 725         mt9t031 = kzalloc(sizeof(struct mt9t031), GFP_KERNEL);
 726         if (!mt9t031)
 727                 return -ENOMEM;
 728
 729         v4l2_i2c_subdev_init(&mt9t031->subdev, client, &mt9t031_subdev_ops);
 730
 731         /* Second stage probe - when a capture adapter is there */
 732         icd->ops                = &mt9t031_ops;
 733         icd->rect_max.left      = MT9T031_COLUMN_SKIP;
 734         icd->rect_max.top       = MT9T031_ROW_SKIP;
 735         icd->rect_current.left  = icd->rect_max.left;
 736         icd->rect_current.top   = icd->rect_max.top;
 737         icd->width_min          = MT9T031_MIN_WIDTH;
 738         icd->rect_max.width     = MT9T031_MAX_WIDTH;
 739         icd->height_min         = MT9T031_MIN_HEIGHT;
 740         icd->rect_max.height    = MT9T031_MAX_HEIGHT;
 741         icd->y_skip_top         = 0;
 742         /* Simulated autoexposure. If enabled, we calculate shutter width
 743          * ourselves in the driver based on vertical blanking and frame width */
 744         mt9t031->autoexposure = 1;
 745
 746         mt9t031->xskip = 1;
 747         mt9t031->yskip = 1;
 748
 749         mt9t031_idle(client);
 750
 751         ret = mt9t031_video_probe(client);
 752
 753         mt9t031_disable(client);
 754
 755         if (ret) {
 756                 icd->ops = NULL;
 757                 i2c_set_clientdata(client, NULL);
 758                 kfree(mt9t031);
 759         }
 760
 761         return ret;
 762 }
 763
 764 static int mt9t031_remove(struct i2c_client *client)
 765 {
 766         struct mt9t031 *mt9t031 = to_mt9t031(client);
 767         struct soc_camera_device *icd = client->dev.platform_data;
 768
 769         icd->ops = NULL;
 770         i2c_set_clientdata(client, NULL);
 771         client->driver = NULL;
 772         kfree(mt9t031);
 773
 774         return 0;
 775 }
 776
 777 static const struct i2c_device_id mt9t031_id[] = {
 778         { "mt9t031", 0 },
 779         { }
 780 };
 781 MODULE_DEVICE_TABLE(i2c, mt9t031_id);
 782
 783 static struct i2c_driver mt9t031_i2c_driver = {
 784         .driver = {
 785                 .name = "mt9t031",
 786         },
 787         .probe          = mt9t031_probe,
 788         .remove         = mt9t031_remove,
 789         .id_table       = mt9t031_id,
 790 };
 791
 792 static int __init mt9t031_mod_init(void)
 793 {
 794         return i2c_add_driver(&mt9t031_i2c_driver);
 795 }
 796
 797 static void __exit mt9t031_mod_exit(void)
 798 {
 799         i2c_del_driver(&mt9t031_i2c_driver);
 800 }
 801
 802 module_init(mt9t031_mod_init);
 803 module_exit(mt9t031_mod_exit);
 804
 805 MODULE_DESCRIPTION("Micron MT9T031 Camera driver");
 806 MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
 807 MODULE_LICENSE("GPL v2");