git.oblomov.eu Git - linux-2.6/blob - drivers/media/video/v4l2-common.c

   1 /*
   2  *      Video for Linux Two
   3  *
   4  *      A generic video device interface for the LINUX operating system
   5  *      using a set of device structures/vectors for low level operations.
   6  *
   7  *      This file replaces the videodev.c file that comes with the
   8  *      regular kernel distribution.
   9  *
  10  *      This program is free software; you can redistribute it and/or
  11  *      modify it under the terms of the GNU General Public License
  12  *      as published by the Free Software Foundation; either version
  13  *      2 of the License, or (at your option) any later version.
  14  *
  15  * Author:      Bill Dirks <bill@thedirks.org>
  16  *              based on code by Alan Cox, <alan@cymru.net>
  17  *
  18  */
  19
  20 /*
  21  * Video capture interface for Linux
  22  *
  23  *      A generic video device interface for the LINUX operating system
  24  *      using a set of device structures/vectors for low level operations.
  25  *
  26  *              This program is free software; you can redistribute it and/or
  27  *              modify it under the terms of the GNU General Public License
  28  *              as published by the Free Software Foundation; either version
  29  *              2 of the License, or (at your option) any later version.
  30  *
  31  * Author:      Alan Cox, <alan@lxorguk.ukuu.org.uk>
  32  *
  33  * Fixes:
  34  */
  35
  36 /*
  37  * Video4linux 1/2 integration by Justin Schoeman
  38  * <justin@suntiger.ee.up.ac.za>
  39  * 2.4 PROCFS support ported from 2.4 kernels by
  40  *  Iñaki García Etxebarria <garetxe@euskalnet.net>
  41  * Makefile fix by "W. Michael Petullo" <mike@flyn.org>
  42  * 2.4 devfs support ported from 2.4 kernels by
  43  *  Dan Merillat <dan@merillat.org>
  44  * Added Gerd Knorrs v4l1 enhancements (Justin Schoeman)
  45  */
  46
  47 #include <linux/module.h>
  48 #include <linux/types.h>
  49 #include <linux/kernel.h>
  50 #include <linux/mm.h>
  51 #include <linux/string.h>
  52 #include <linux/errno.h>
  53 #include <linux/i2c.h>
  54 #include <asm/uaccess.h>
  55 #include <asm/system.h>
  56 #include <asm/pgtable.h>
  57 #include <asm/io.h>
  58 #include <asm/div64.h>
  59 #define __OLD_VIDIOC_ /* To allow fixing old calls*/
  60 #include <media/v4l2-common.h>
  61 #include <media/v4l2-device.h>
  62 #include <media/v4l2-chip-ident.h>
  63
  64 #include <linux/videodev2.h>
  65
  66 MODULE_AUTHOR("Bill Dirks, Justin Schoeman, Gerd Knorr");
  67 MODULE_DESCRIPTION("misc helper functions for v4l2 device drivers");
  68 MODULE_LICENSE("GPL");
  69
  70 /*
  71  *
  72  *      V 4 L 2   D R I V E R   H E L P E R   A P I
  73  *
  74  */
  75
  76 /*
  77  *  Video Standard Operations (contributed by Michael Schimek)
  78  */
  79
  80
  81 /* ----------------------------------------------------------------- */
  82 /* priority handling                                                 */
  83
  84 #define V4L2_PRIO_VALID(val) (val == V4L2_PRIORITY_BACKGROUND   || \
  85                               val == V4L2_PRIORITY_INTERACTIVE  || \
  86                               val == V4L2_PRIORITY_RECORD)
  87
  88 int v4l2_prio_init(struct v4l2_prio_state *global)
  89 {
  90         memset(global,0,sizeof(*global));
  91         return 0;
  92 }
  93 EXPORT_SYMBOL(v4l2_prio_init);
  94
  95 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
  96                      enum v4l2_priority new)
  97 {
  98         if (!V4L2_PRIO_VALID(new))
  99                 return -EINVAL;
 100         if (*local == new)
 101                 return 0;
 102
 103         atomic_inc(&global->prios[new]);
 104         if (V4L2_PRIO_VALID(*local))
 105                 atomic_dec(&global->prios[*local]);
 106         *local = new;
 107         return 0;
 108 }
 109 EXPORT_SYMBOL(v4l2_prio_change);
 110
 111 int v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local)
 112 {
 113         return v4l2_prio_change(global,local,V4L2_PRIORITY_DEFAULT);
 114 }
 115 EXPORT_SYMBOL(v4l2_prio_open);
 116
 117 int v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority *local)
 118 {
 119         if (V4L2_PRIO_VALID(*local))
 120                 atomic_dec(&global->prios[*local]);
 121         return 0;
 122 }
 123 EXPORT_SYMBOL(v4l2_prio_close);
 124
 125 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global)
 126 {
 127         if (atomic_read(&global->prios[V4L2_PRIORITY_RECORD]) > 0)
 128                 return V4L2_PRIORITY_RECORD;
 129         if (atomic_read(&global->prios[V4L2_PRIORITY_INTERACTIVE]) > 0)
 130                 return V4L2_PRIORITY_INTERACTIVE;
 131         if (atomic_read(&global->prios[V4L2_PRIORITY_BACKGROUND]) > 0)
 132                 return V4L2_PRIORITY_BACKGROUND;
 133         return V4L2_PRIORITY_UNSET;
 134 }
 135 EXPORT_SYMBOL(v4l2_prio_max);
 136
 137 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority *local)
 138 {
 139         if (*local < v4l2_prio_max(global))
 140                 return -EBUSY;
 141         return 0;
 142 }
 143 EXPORT_SYMBOL(v4l2_prio_check);
 144
 145 /* ----------------------------------------------------------------- */
 146
 147 /* Helper functions for control handling                             */
 148
 149 /* Check for correctness of the ctrl's value based on the data from
 150    struct v4l2_queryctrl and the available menu items. Note that
 151    menu_items may be NULL, in that case it is ignored. */
 152 int v4l2_ctrl_check(struct v4l2_ext_control *ctrl, struct v4l2_queryctrl *qctrl,
 153                 const char **menu_items)
 154 {
 155         if (qctrl->flags & V4L2_CTRL_FLAG_DISABLED)
 156                 return -EINVAL;
 157         if (qctrl->flags & V4L2_CTRL_FLAG_GRABBED)
 158                 return -EBUSY;
 159         if (qctrl->type == V4L2_CTRL_TYPE_BUTTON ||
 160             qctrl->type == V4L2_CTRL_TYPE_INTEGER64 ||
 161             qctrl->type == V4L2_CTRL_TYPE_CTRL_CLASS)
 162                 return 0;
 163         if (ctrl->value < qctrl->minimum || ctrl->value > qctrl->maximum)
 164                 return -ERANGE;
 165         if (qctrl->type == V4L2_CTRL_TYPE_MENU && menu_items != NULL) {
 166                 if (menu_items[ctrl->value] == NULL ||
 167                     menu_items[ctrl->value][0] == '\0')
 168                         return -EINVAL;
 169         }
 170         return 0;
 171 }
 172 EXPORT_SYMBOL(v4l2_ctrl_check);
 173
 174 /* Returns NULL or a character pointer array containing the menu for
 175    the given control ID. The pointer array ends with a NULL pointer.
 176    An empty string signifies a menu entry that is invalid. This allows
 177    drivers to disable certain options if it is not supported. */
 178 const char **v4l2_ctrl_get_menu(u32 id)
 179 {
 180         static const char *mpeg_audio_sampling_freq[] = {
 181                 "44.1 kHz",
 182                 "48 kHz",
 183                 "32 kHz",
 184                 NULL
 185         };
 186         static const char *mpeg_audio_encoding[] = {
 187                 "MPEG-1/2 Layer I",
 188                 "MPEG-1/2 Layer II",
 189                 "MPEG-1/2 Layer III",
 190                 "MPEG-2/4 AAC",
 191                 "AC-3",
 192                 NULL
 193         };
 194         static const char *mpeg_audio_l1_bitrate[] = {
 195                 "32 kbps",
 196                 "64 kbps",
 197                 "96 kbps",
 198                 "128 kbps",
 199                 "160 kbps",
 200                 "192 kbps",
 201                 "224 kbps",
 202                 "256 kbps",
 203                 "288 kbps",
 204                 "320 kbps",
 205                 "352 kbps",
 206                 "384 kbps",
 207                 "416 kbps",
 208                 "448 kbps",
 209                 NULL
 210         };
 211         static const char *mpeg_audio_l2_bitrate[] = {
 212                 "32 kbps",
 213                 "48 kbps",
 214                 "56 kbps",
 215                 "64 kbps",
 216                 "80 kbps",
 217                 "96 kbps",
 218                 "112 kbps",
 219                 "128 kbps",
 220                 "160 kbps",
 221                 "192 kbps",
 222                 "224 kbps",
 223                 "256 kbps",
 224                 "320 kbps",
 225                 "384 kbps",
 226                 NULL
 227         };
 228         static const char *mpeg_audio_l3_bitrate[] = {
 229                 "32 kbps",
 230                 "40 kbps",
 231                 "48 kbps",
 232                 "56 kbps",
 233                 "64 kbps",
 234                 "80 kbps",
 235                 "96 kbps",
 236                 "112 kbps",
 237                 "128 kbps",
 238                 "160 kbps",
 239                 "192 kbps",
 240                 "224 kbps",
 241                 "256 kbps",
 242                 "320 kbps",
 243                 NULL
 244         };
 245         static const char *mpeg_audio_ac3_bitrate[] = {
 246                 "32 kbps",
 247                 "40 kbps",
 248                 "48 kbps",
 249                 "56 kbps",
 250                 "64 kbps",
 251                 "80 kbps",
 252                 "96 kbps",
 253                 "112 kbps",
 254                 "128 kbps",
 255                 "160 kbps",
 256                 "192 kbps",
 257                 "224 kbps",
 258                 "256 kbps",
 259                 "320 kbps",
 260                 "384 kbps",
 261                 "448 kbps",
 262                 "512 kbps",
 263                 "576 kbps",
 264                 "640 kbps",
 265                 NULL
 266         };
 267         static const char *mpeg_audio_mode[] = {
 268                 "Stereo",
 269                 "Joint Stereo",
 270                 "Dual",
 271                 "Mono",
 272                 NULL
 273         };
 274         static const char *mpeg_audio_mode_extension[] = {
 275                 "Bound 4",
 276                 "Bound 8",
 277                 "Bound 12",
 278                 "Bound 16",
 279                 NULL
 280         };
 281         static const char *mpeg_audio_emphasis[] = {
 282                 "No Emphasis",
 283                 "50/15 us",
 284                 "CCITT J17",
 285                 NULL
 286         };
 287         static const char *mpeg_audio_crc[] = {
 288                 "No CRC",
 289                 "16-bit CRC",
 290                 NULL
 291         };
 292         static const char *mpeg_video_encoding[] = {
 293                 "MPEG-1",
 294                 "MPEG-2",
 295                 "MPEG-4 AVC",
 296                 NULL
 297         };
 298         static const char *mpeg_video_aspect[] = {
 299                 "1x1",
 300                 "4x3",
 301                 "16x9",
 302                 "2.21x1",
 303                 NULL
 304         };
 305         static const char *mpeg_video_bitrate_mode[] = {
 306                 "Variable Bitrate",
 307                 "Constant Bitrate",
 308                 NULL
 309         };
 310         static const char *mpeg_stream_type[] = {
 311                 "MPEG-2 Program Stream",
 312                 "MPEG-2 Transport Stream",
 313                 "MPEG-1 System Stream",
 314                 "MPEG-2 DVD-compatible Stream",
 315                 "MPEG-1 VCD-compatible Stream",
 316                 "MPEG-2 SVCD-compatible Stream",
 317                 NULL
 318         };
 319         static const char *mpeg_stream_vbi_fmt[] = {
 320                 "No VBI",
 321                 "Private packet, IVTV format",
 322                 NULL
 323         };
 324         static const char *camera_power_line_frequency[] = {
 325                 "Disabled",
 326                 "50 Hz",
 327                 "60 Hz",
 328                 NULL
 329         };
 330         static const char *camera_exposure_auto[] = {
 331                 "Auto Mode",
 332                 "Manual Mode",
 333                 "Shutter Priority Mode",
 334                 "Aperture Priority Mode",
 335                 NULL
 336         };
 337
 338         switch (id) {
 339                 case V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ:
 340                         return mpeg_audio_sampling_freq;
 341                 case V4L2_CID_MPEG_AUDIO_ENCODING:
 342                         return mpeg_audio_encoding;
 343                 case V4L2_CID_MPEG_AUDIO_L1_BITRATE:
 344                         return mpeg_audio_l1_bitrate;
 345                 case V4L2_CID_MPEG_AUDIO_L2_BITRATE:
 346                         return mpeg_audio_l2_bitrate;
 347                 case V4L2_CID_MPEG_AUDIO_L3_BITRATE:
 348                         return mpeg_audio_l3_bitrate;
 349                 case V4L2_CID_MPEG_AUDIO_AC3_BITRATE:
 350                         return mpeg_audio_ac3_bitrate;
 351                 case V4L2_CID_MPEG_AUDIO_MODE:
 352                         return mpeg_audio_mode;
 353                 case V4L2_CID_MPEG_AUDIO_MODE_EXTENSION:
 354                         return mpeg_audio_mode_extension;
 355                 case V4L2_CID_MPEG_AUDIO_EMPHASIS:
 356                         return mpeg_audio_emphasis;
 357                 case V4L2_CID_MPEG_AUDIO_CRC:
 358                         return mpeg_audio_crc;
 359                 case V4L2_CID_MPEG_VIDEO_ENCODING:
 360                         return mpeg_video_encoding;
 361                 case V4L2_CID_MPEG_VIDEO_ASPECT:
 362                         return mpeg_video_aspect;
 363                 case V4L2_CID_MPEG_VIDEO_BITRATE_MODE:
 364                         return mpeg_video_bitrate_mode;
 365                 case V4L2_CID_MPEG_STREAM_TYPE:
 366                         return mpeg_stream_type;
 367                 case V4L2_CID_MPEG_STREAM_VBI_FMT:
 368                         return mpeg_stream_vbi_fmt;
 369                 case V4L2_CID_POWER_LINE_FREQUENCY:
 370                         return camera_power_line_frequency;
 371                 case V4L2_CID_EXPOSURE_AUTO:
 372                         return camera_exposure_auto;
 373                 default:
 374                         return NULL;
 375         }
 376 }
 377 EXPORT_SYMBOL(v4l2_ctrl_get_menu);
 378
 379 /* Return the control name. */
 380 const char *v4l2_ctrl_get_name(u32 id)
 381 {
 382         switch (id) {
 383         /* USER controls */
 384         case V4L2_CID_USER_CLASS:               return "User Controls";
 385         case V4L2_CID_AUDIO_VOLUME:             return "Volume";
 386         case V4L2_CID_AUDIO_MUTE:               return "Mute";
 387         case V4L2_CID_AUDIO_BALANCE:            return "Balance";
 388         case V4L2_CID_AUDIO_BASS:               return "Bass";
 389         case V4L2_CID_AUDIO_TREBLE:             return "Treble";
 390         case V4L2_CID_AUDIO_LOUDNESS:           return "Loudness";
 391         case V4L2_CID_BRIGHTNESS:               return "Brightness";
 392         case V4L2_CID_CONTRAST:                 return "Contrast";
 393         case V4L2_CID_SATURATION:               return "Saturation";
 394         case V4L2_CID_HUE:                      return "Hue";
 395         case V4L2_CID_BLACK_LEVEL:              return "Black Level";
 396         case V4L2_CID_AUTO_WHITE_BALANCE:       return "White Balance, Automatic";
 397         case V4L2_CID_DO_WHITE_BALANCE:         return "Do White Balance";
 398         case V4L2_CID_RED_BALANCE:              return "Red Balance";
 399         case V4L2_CID_BLUE_BALANCE:             return "Blue Balance";
 400         case V4L2_CID_GAMMA:                    return "Gamma";
 401         case V4L2_CID_EXPOSURE:                 return "Exposure";
 402         case V4L2_CID_AUTOGAIN:                 return "Gain, Automatic";
 403         case V4L2_CID_GAIN:                     return "Gain";
 404         case V4L2_CID_HFLIP:                    return "Horizontal Flip";
 405         case V4L2_CID_VFLIP:                    return "Vertical Flip";
 406         case V4L2_CID_HCENTER:                  return "Horizontal Center";
 407         case V4L2_CID_VCENTER:                  return "Vertical Center";
 408         case V4L2_CID_POWER_LINE_FREQUENCY:     return "Power Line Frequency";
 409         case V4L2_CID_HUE_AUTO:                 return "Hue, Automatic";
 410         case V4L2_CID_WHITE_BALANCE_TEMPERATURE: return "White Balance Temperature";
 411         case V4L2_CID_SHARPNESS:                return "Sharpness";
 412         case V4L2_CID_BACKLIGHT_COMPENSATION:   return "Backlight Compensation";
 413         case V4L2_CID_CHROMA_AGC:               return "Chroma AGC";
 414         case V4L2_CID_COLOR_KILLER:             return "Color Killer";
 415
 416         /* MPEG controls */
 417         case V4L2_CID_MPEG_CLASS:               return "MPEG Encoder Controls";
 418         case V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ: return "Audio Sampling Frequency";
 419         case V4L2_CID_MPEG_AUDIO_ENCODING:      return "Audio Encoding";
 420         case V4L2_CID_MPEG_AUDIO_L1_BITRATE:    return "Audio Layer I Bitrate";
 421         case V4L2_CID_MPEG_AUDIO_L2_BITRATE:    return "Audio Layer II Bitrate";
 422         case V4L2_CID_MPEG_AUDIO_L3_BITRATE:    return "Audio Layer III Bitrate";
 423         case V4L2_CID_MPEG_AUDIO_AAC_BITRATE:   return "Audio AAC Bitrate";
 424         case V4L2_CID_MPEG_AUDIO_AC3_BITRATE:   return "Audio AC-3 Bitrate";
 425         case V4L2_CID_MPEG_AUDIO_MODE:          return "Audio Stereo Mode";
 426         case V4L2_CID_MPEG_AUDIO_MODE_EXTENSION: return "Audio Stereo Mode Extension";
 427         case V4L2_CID_MPEG_AUDIO_EMPHASIS:      return "Audio Emphasis";
 428         case V4L2_CID_MPEG_AUDIO_CRC:           return "Audio CRC";
 429         case V4L2_CID_MPEG_AUDIO_MUTE:          return "Audio Mute";
 430         case V4L2_CID_MPEG_VIDEO_ENCODING:      return "Video Encoding";
 431         case V4L2_CID_MPEG_VIDEO_ASPECT:        return "Video Aspect";
 432         case V4L2_CID_MPEG_VIDEO_B_FRAMES:      return "Video B Frames";
 433         case V4L2_CID_MPEG_VIDEO_GOP_SIZE:      return "Video GOP Size";
 434         case V4L2_CID_MPEG_VIDEO_GOP_CLOSURE:   return "Video GOP Closure";
 435         case V4L2_CID_MPEG_VIDEO_PULLDOWN:      return "Video Pulldown";
 436         case V4L2_CID_MPEG_VIDEO_BITRATE_MODE:  return "Video Bitrate Mode";
 437         case V4L2_CID_MPEG_VIDEO_BITRATE:       return "Video Bitrate";
 438         case V4L2_CID_MPEG_VIDEO_BITRATE_PEAK:  return "Video Peak Bitrate";
 439         case V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION: return "Video Temporal Decimation";
 440         case V4L2_CID_MPEG_VIDEO_MUTE:          return "Video Mute";
 441         case V4L2_CID_MPEG_VIDEO_MUTE_YUV:      return "Video Mute YUV";
 442         case V4L2_CID_MPEG_STREAM_TYPE:         return "Stream Type";
 443         case V4L2_CID_MPEG_STREAM_PID_PMT:      return "Stream PMT Program ID";
 444         case V4L2_CID_MPEG_STREAM_PID_AUDIO:    return "Stream Audio Program ID";
 445         case V4L2_CID_MPEG_STREAM_PID_VIDEO:    return "Stream Video Program ID";
 446         case V4L2_CID_MPEG_STREAM_PID_PCR:      return "Stream PCR Program ID";
 447         case V4L2_CID_MPEG_STREAM_PES_ID_AUDIO: return "Stream PES Audio ID";
 448         case V4L2_CID_MPEG_STREAM_PES_ID_VIDEO: return "Stream PES Video ID";
 449         case V4L2_CID_MPEG_STREAM_VBI_FMT:      return "Stream VBI Format";
 450
 451         /* CAMERA controls */
 452         case V4L2_CID_CAMERA_CLASS:             return "Camera Controls";
 453         case V4L2_CID_EXPOSURE_AUTO:            return "Auto Exposure";
 454         case V4L2_CID_EXPOSURE_ABSOLUTE:        return "Exposure Time, Absolute";
 455         case V4L2_CID_EXPOSURE_AUTO_PRIORITY:   return "Exposure, Dynamic Framerate";
 456         case V4L2_CID_PAN_RELATIVE:             return "Pan, Relative";
 457         case V4L2_CID_TILT_RELATIVE:            return "Tilt, Relative";
 458         case V4L2_CID_PAN_RESET:                return "Pan, Reset";
 459         case V4L2_CID_TILT_RESET:               return "Tilt, Reset";
 460         case V4L2_CID_PAN_ABSOLUTE:             return "Pan, Absolute";
 461         case V4L2_CID_TILT_ABSOLUTE:            return "Tilt, Absolute";
 462         case V4L2_CID_FOCUS_ABSOLUTE:           return "Focus, Absolute";
 463         case V4L2_CID_FOCUS_RELATIVE:           return "Focus, Relative";
 464         case V4L2_CID_FOCUS_AUTO:               return "Focus, Automatic";
 465         case V4L2_CID_ZOOM_ABSOLUTE:            return "Zoom, Absolute";
 466         case V4L2_CID_ZOOM_RELATIVE:            return "Zoom, Relative";
 467         case V4L2_CID_ZOOM_CONTINUOUS:          return "Zoom, Continuous";
 468         case V4L2_CID_PRIVACY:                  return "Privacy";
 469
 470         default:
 471                 return NULL;
 472         }
 473 }
 474 EXPORT_SYMBOL(v4l2_ctrl_get_name);
 475
 476 /* Fill in a struct v4l2_queryctrl */
 477 int v4l2_ctrl_query_fill(struct v4l2_queryctrl *qctrl, s32 min, s32 max, s32 step, s32 def)
 478 {
 479         const char *name = v4l2_ctrl_get_name(qctrl->id);
 480
 481         qctrl->flags = 0;
 482         if (name == NULL)
 483                 return -EINVAL;
 484
 485         switch (qctrl->id) {
 486         case V4L2_CID_AUDIO_MUTE:
 487         case V4L2_CID_AUDIO_LOUDNESS:
 488         case V4L2_CID_AUTO_WHITE_BALANCE:
 489         case V4L2_CID_AUTOGAIN:
 490         case V4L2_CID_HFLIP:
 491         case V4L2_CID_VFLIP:
 492         case V4L2_CID_HUE_AUTO:
 493         case V4L2_CID_MPEG_AUDIO_MUTE:
 494         case V4L2_CID_MPEG_VIDEO_MUTE:
 495         case V4L2_CID_MPEG_VIDEO_GOP_CLOSURE:
 496         case V4L2_CID_MPEG_VIDEO_PULLDOWN:
 497         case V4L2_CID_EXPOSURE_AUTO_PRIORITY:
 498         case V4L2_CID_PRIVACY:
 499                 qctrl->type = V4L2_CTRL_TYPE_BOOLEAN;
 500                 min = 0;
 501                 max = step = 1;
 502                 break;
 503         case V4L2_CID_POWER_LINE_FREQUENCY:
 504         case V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ:
 505         case V4L2_CID_MPEG_AUDIO_ENCODING:
 506         case V4L2_CID_MPEG_AUDIO_L1_BITRATE:
 507         case V4L2_CID_MPEG_AUDIO_L2_BITRATE:
 508         case V4L2_CID_MPEG_AUDIO_L3_BITRATE:
 509         case V4L2_CID_MPEG_AUDIO_AC3_BITRATE:
 510         case V4L2_CID_MPEG_AUDIO_MODE:
 511         case V4L2_CID_MPEG_AUDIO_MODE_EXTENSION:
 512         case V4L2_CID_MPEG_AUDIO_EMPHASIS:
 513         case V4L2_CID_MPEG_AUDIO_CRC:
 514         case V4L2_CID_MPEG_VIDEO_ENCODING:
 515         case V4L2_CID_MPEG_VIDEO_ASPECT:
 516         case V4L2_CID_MPEG_VIDEO_BITRATE_MODE:
 517         case V4L2_CID_MPEG_STREAM_TYPE:
 518         case V4L2_CID_MPEG_STREAM_VBI_FMT:
 519         case V4L2_CID_EXPOSURE_AUTO:
 520                 qctrl->type = V4L2_CTRL_TYPE_MENU;
 521                 step = 1;
 522                 break;
 523         case V4L2_CID_USER_CLASS:
 524         case V4L2_CID_CAMERA_CLASS:
 525         case V4L2_CID_MPEG_CLASS:
 526                 qctrl->type = V4L2_CTRL_TYPE_CTRL_CLASS;
 527                 qctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
 528                 min = max = step = def = 0;
 529                 break;
 530         default:
 531                 qctrl->type = V4L2_CTRL_TYPE_INTEGER;
 532                 break;
 533         }
 534         switch (qctrl->id) {
 535         case V4L2_CID_MPEG_AUDIO_ENCODING:
 536         case V4L2_CID_MPEG_AUDIO_MODE:
 537         case V4L2_CID_MPEG_VIDEO_BITRATE_MODE:
 538         case V4L2_CID_MPEG_VIDEO_B_FRAMES:
 539         case V4L2_CID_MPEG_STREAM_TYPE:
 540                 qctrl->flags |= V4L2_CTRL_FLAG_UPDATE;
 541                 break;
 542         case V4L2_CID_AUDIO_VOLUME:
 543         case V4L2_CID_AUDIO_BALANCE:
 544         case V4L2_CID_AUDIO_BASS:
 545         case V4L2_CID_AUDIO_TREBLE:
 546         case V4L2_CID_BRIGHTNESS:
 547         case V4L2_CID_CONTRAST:
 548         case V4L2_CID_SATURATION:
 549         case V4L2_CID_HUE:
 550                 qctrl->flags |= V4L2_CTRL_FLAG_SLIDER;
 551                 break;
 552         }
 553         qctrl->minimum = min;
 554         qctrl->maximum = max;
 555         qctrl->step = step;
 556         qctrl->default_value = def;
 557         qctrl->reserved[0] = qctrl->reserved[1] = 0;
 558         snprintf(qctrl->name, sizeof(qctrl->name), name);
 559         return 0;
 560 }
 561 EXPORT_SYMBOL(v4l2_ctrl_query_fill);
 562
 563 /* Fill in a struct v4l2_queryctrl with standard values based on
 564    the control ID. */
 565 int v4l2_ctrl_query_fill_std(struct v4l2_queryctrl *qctrl)
 566 {
 567         switch (qctrl->id) {
 568         /* USER controls */
 569         case V4L2_CID_USER_CLASS:
 570         case V4L2_CID_MPEG_CLASS:
 571                 return v4l2_ctrl_query_fill(qctrl, 0, 0, 0, 0);
 572         case V4L2_CID_AUDIO_VOLUME:
 573                 return v4l2_ctrl_query_fill(qctrl, 0, 65535, 65535 / 100, 58880);
 574         case V4L2_CID_AUDIO_MUTE:
 575         case V4L2_CID_AUDIO_LOUDNESS:
 576                 return v4l2_ctrl_query_fill(qctrl, 0, 1, 1, 0);
 577         case V4L2_CID_AUDIO_BALANCE:
 578         case V4L2_CID_AUDIO_BASS:
 579         case V4L2_CID_AUDIO_TREBLE:
 580                 return v4l2_ctrl_query_fill(qctrl, 0, 65535, 65535 / 100, 32768);
 581         case V4L2_CID_BRIGHTNESS:
 582                 return v4l2_ctrl_query_fill(qctrl, 0, 255, 1, 128);
 583         case V4L2_CID_CONTRAST:
 584         case V4L2_CID_SATURATION:
 585                 return v4l2_ctrl_query_fill(qctrl, 0, 127, 1, 64);
 586         case V4L2_CID_HUE:
 587                 return v4l2_ctrl_query_fill(qctrl, -128, 127, 1, 0);
 588
 589         /* MPEG controls */
 590         case V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ:
 591                 return v4l2_ctrl_query_fill(qctrl,
 592                                 V4L2_MPEG_AUDIO_SAMPLING_FREQ_44100,
 593                                 V4L2_MPEG_AUDIO_SAMPLING_FREQ_32000, 1,
 594                                 V4L2_MPEG_AUDIO_SAMPLING_FREQ_48000);
 595         case V4L2_CID_MPEG_AUDIO_ENCODING:
 596                 return v4l2_ctrl_query_fill(qctrl,
 597                                 V4L2_MPEG_AUDIO_ENCODING_LAYER_1,
 598                                 V4L2_MPEG_AUDIO_ENCODING_AC3, 1,
 599                                 V4L2_MPEG_AUDIO_ENCODING_LAYER_2);
 600         case V4L2_CID_MPEG_AUDIO_L1_BITRATE:
 601                 return v4l2_ctrl_query_fill(qctrl,
 602                                 V4L2_MPEG_AUDIO_L1_BITRATE_32K,
 603                                 V4L2_MPEG_AUDIO_L1_BITRATE_448K, 1,
 604                                 V4L2_MPEG_AUDIO_L1_BITRATE_256K);
 605         case V4L2_CID_MPEG_AUDIO_L2_BITRATE:
 606                 return v4l2_ctrl_query_fill(qctrl,
 607                                 V4L2_MPEG_AUDIO_L2_BITRATE_32K,
 608                                 V4L2_MPEG_AUDIO_L2_BITRATE_384K, 1,
 609                                 V4L2_MPEG_AUDIO_L2_BITRATE_224K);
 610         case V4L2_CID_MPEG_AUDIO_L3_BITRATE:
 611                 return v4l2_ctrl_query_fill(qctrl,
 612                                 V4L2_MPEG_AUDIO_L3_BITRATE_32K,
 613                                 V4L2_MPEG_AUDIO_L3_BITRATE_320K, 1,
 614                                 V4L2_MPEG_AUDIO_L3_BITRATE_192K);
 615         case V4L2_CID_MPEG_AUDIO_AAC_BITRATE:
 616                 return v4l2_ctrl_query_fill(qctrl, 0, 6400, 1, 3200000);
 617         case V4L2_CID_MPEG_AUDIO_AC3_BITRATE:
 618                 return v4l2_ctrl_query_fill(qctrl,
 619                                 V4L2_MPEG_AUDIO_AC3_BITRATE_32K,
 620                                 V4L2_MPEG_AUDIO_AC3_BITRATE_640K, 1,
 621                                 V4L2_MPEG_AUDIO_AC3_BITRATE_384K);
 622         case V4L2_CID_MPEG_AUDIO_MODE:
 623                 return v4l2_ctrl_query_fill(qctrl,
 624                                 V4L2_MPEG_AUDIO_MODE_STEREO,
 625                                 V4L2_MPEG_AUDIO_MODE_MONO, 1,
 626                                 V4L2_MPEG_AUDIO_MODE_STEREO);
 627         case V4L2_CID_MPEG_AUDIO_MODE_EXTENSION:
 628                 return v4l2_ctrl_query_fill(qctrl,
 629                                 V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_4,
 630                                 V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_16, 1,
 631                                 V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_4);
 632         case V4L2_CID_MPEG_AUDIO_EMPHASIS:
 633                 return v4l2_ctrl_query_fill(qctrl,
 634                                 V4L2_MPEG_AUDIO_EMPHASIS_NONE,
 635                                 V4L2_MPEG_AUDIO_EMPHASIS_CCITT_J17, 1,
 636                                 V4L2_MPEG_AUDIO_EMPHASIS_NONE);
 637         case V4L2_CID_MPEG_AUDIO_CRC:
 638                 return v4l2_ctrl_query_fill(qctrl,
 639                                 V4L2_MPEG_AUDIO_CRC_NONE,
 640                                 V4L2_MPEG_AUDIO_CRC_CRC16, 1,
 641                                 V4L2_MPEG_AUDIO_CRC_NONE);
 642         case V4L2_CID_MPEG_AUDIO_MUTE:
 643                 return v4l2_ctrl_query_fill(qctrl, 0, 1, 1, 0);
 644         case V4L2_CID_MPEG_VIDEO_ENCODING:
 645                 return v4l2_ctrl_query_fill(qctrl,
 646                                 V4L2_MPEG_VIDEO_ENCODING_MPEG_1,
 647                                 V4L2_MPEG_VIDEO_ENCODING_MPEG_4_AVC, 1,
 648                                 V4L2_MPEG_VIDEO_ENCODING_MPEG_2);
 649         case V4L2_CID_MPEG_VIDEO_ASPECT:
 650                 return v4l2_ctrl_query_fill(qctrl,
 651                                 V4L2_MPEG_VIDEO_ASPECT_1x1,
 652                                 V4L2_MPEG_VIDEO_ASPECT_221x100, 1,
 653                                 V4L2_MPEG_VIDEO_ASPECT_4x3);
 654         case V4L2_CID_MPEG_VIDEO_B_FRAMES:
 655                 return v4l2_ctrl_query_fill(qctrl, 0, 33, 1, 2);
 656         case V4L2_CID_MPEG_VIDEO_GOP_SIZE:
 657                 return v4l2_ctrl_query_fill(qctrl, 1, 34, 1, 12);
 658         case V4L2_CID_MPEG_VIDEO_GOP_CLOSURE:
 659                 return v4l2_ctrl_query_fill(qctrl, 0, 1, 1, 1);
 660         case V4L2_CID_MPEG_VIDEO_PULLDOWN:
 661                 return v4l2_ctrl_query_fill(qctrl, 0, 1, 1, 0);
 662         case V4L2_CID_MPEG_VIDEO_BITRATE_MODE:
 663                 return v4l2_ctrl_query_fill(qctrl,
 664                                 V4L2_MPEG_VIDEO_BITRATE_MODE_VBR,
 665                                 V4L2_MPEG_VIDEO_BITRATE_MODE_CBR, 1,
 666                                 V4L2_MPEG_VIDEO_BITRATE_MODE_VBR);
 667         case V4L2_CID_MPEG_VIDEO_BITRATE:
 668                 return v4l2_ctrl_query_fill(qctrl, 0, 27000000, 1, 6000000);
 669         case V4L2_CID_MPEG_VIDEO_BITRATE_PEAK:
 670                 return v4l2_ctrl_query_fill(qctrl, 0, 27000000, 1, 8000000);
 671         case V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION:
 672                 return v4l2_ctrl_query_fill(qctrl, 0, 255, 1, 0);
 673         case V4L2_CID_MPEG_VIDEO_MUTE:
 674                 return v4l2_ctrl_query_fill(qctrl, 0, 1, 1, 0);
 675         case V4L2_CID_MPEG_VIDEO_MUTE_YUV:  /* Init YUV (really YCbCr) to black */
 676                 return v4l2_ctrl_query_fill(qctrl, 0, 0xffffff, 1, 0x008080);
 677         case V4L2_CID_MPEG_STREAM_TYPE:
 678                 return v4l2_ctrl_query_fill(qctrl,
 679                                 V4L2_MPEG_STREAM_TYPE_MPEG2_PS,
 680                                 V4L2_MPEG_STREAM_TYPE_MPEG2_SVCD, 1,
 681                                 V4L2_MPEG_STREAM_TYPE_MPEG2_PS);
 682         case V4L2_CID_MPEG_STREAM_PID_PMT:
 683                 return v4l2_ctrl_query_fill(qctrl, 0, (1 << 14) - 1, 1, 16);
 684         case V4L2_CID_MPEG_STREAM_PID_AUDIO:
 685                 return v4l2_ctrl_query_fill(qctrl, 0, (1 << 14) - 1, 1, 260);
 686         case V4L2_CID_MPEG_STREAM_PID_VIDEO:
 687                 return v4l2_ctrl_query_fill(qctrl, 0, (1 << 14) - 1, 1, 256);
 688         case V4L2_CID_MPEG_STREAM_PID_PCR:
 689                 return v4l2_ctrl_query_fill(qctrl, 0, (1 << 14) - 1, 1, 259);
 690         case V4L2_CID_MPEG_STREAM_PES_ID_AUDIO:
 691                 return v4l2_ctrl_query_fill(qctrl, 0, 255, 1, 0);
 692         case V4L2_CID_MPEG_STREAM_PES_ID_VIDEO:
 693                 return v4l2_ctrl_query_fill(qctrl, 0, 255, 1, 0);
 694         case V4L2_CID_MPEG_STREAM_VBI_FMT:
 695                 return v4l2_ctrl_query_fill(qctrl,
 696                                 V4L2_MPEG_STREAM_VBI_FMT_NONE,
 697                                 V4L2_MPEG_STREAM_VBI_FMT_IVTV, 1,
 698                                 V4L2_MPEG_STREAM_VBI_FMT_NONE);
 699         default:
 700                 return -EINVAL;
 701         }
 702 }
 703 EXPORT_SYMBOL(v4l2_ctrl_query_fill_std);
 704
 705 /* Fill in a struct v4l2_querymenu based on the struct v4l2_queryctrl and
 706    the menu. The qctrl pointer may be NULL, in which case it is ignored.
 707    If menu_items is NULL, then the menu items are retrieved using
 708    v4l2_ctrl_get_menu. */
 709 int v4l2_ctrl_query_menu(struct v4l2_querymenu *qmenu, struct v4l2_queryctrl *qctrl,
 710                const char **menu_items)
 711 {
 712         int i;
 713
 714         qmenu->reserved = 0;
 715         if (menu_items == NULL)
 716                 menu_items = v4l2_ctrl_get_menu(qmenu->id);
 717         if (menu_items == NULL ||
 718             (qctrl && (qmenu->index < qctrl->minimum || qmenu->index > qctrl->maximum)))
 719                 return -EINVAL;
 720         for (i = 0; i < qmenu->index && menu_items[i]; i++) ;
 721         if (menu_items[i] == NULL || menu_items[i][0] == '\0')
 722                 return -EINVAL;
 723         snprintf(qmenu->name, sizeof(qmenu->name), menu_items[qmenu->index]);
 724         return 0;
 725 }
 726 EXPORT_SYMBOL(v4l2_ctrl_query_menu);
 727
 728 /* Fill in a struct v4l2_querymenu based on the specified array of valid
 729    menu items (terminated by V4L2_CTRL_MENU_IDS_END).
 730    Use this if there are 'holes' in the list of valid menu items. */
 731 int v4l2_ctrl_query_menu_valid_items(struct v4l2_querymenu *qmenu, const u32 *ids)
 732 {
 733         const char **menu_items = v4l2_ctrl_get_menu(qmenu->id);
 734
 735         qmenu->reserved = 0;
 736         if (menu_items == NULL || ids == NULL)
 737                 return -EINVAL;
 738         while (*ids != V4L2_CTRL_MENU_IDS_END) {
 739                 if (*ids++ == qmenu->index) {
 740                         snprintf(qmenu->name, sizeof(qmenu->name),
 741                                        menu_items[qmenu->index]);
 742                         return 0;
 743                 }
 744         }
 745         return -EINVAL;
 746 }
 747 EXPORT_SYMBOL(v4l2_ctrl_query_menu_valid_items);
 748
 749 /* ctrl_classes points to an array of u32 pointers, the last element is
 750    a NULL pointer. Each u32 array is a 0-terminated array of control IDs.
 751    Each array must be sorted low to high and belong to the same control
 752    class. The array of u32 pointer must also be sorted, from low class IDs
 753    to high class IDs.
 754
 755    This function returns the first ID that follows after the given ID.
 756    When no more controls are available 0 is returned. */
 757 u32 v4l2_ctrl_next(const u32 * const * ctrl_classes, u32 id)
 758 {
 759         u32 ctrl_class = V4L2_CTRL_ID2CLASS(id);
 760         const u32 *pctrl;
 761
 762         if (ctrl_classes == NULL)
 763                 return 0;
 764
 765         /* if no query is desired, then check if the ID is part of ctrl_classes */
 766         if ((id & V4L2_CTRL_FLAG_NEXT_CTRL) == 0) {
 767                 /* find class */
 768                 while (*ctrl_classes && V4L2_CTRL_ID2CLASS(**ctrl_classes) != ctrl_class)
 769                         ctrl_classes++;
 770                 if (*ctrl_classes == NULL)
 771                         return 0;
 772                 pctrl = *ctrl_classes;
 773                 /* find control ID */
 774                 while (*pctrl && *pctrl != id) pctrl++;
 775                 return *pctrl ? id : 0;
 776         }
 777         id &= V4L2_CTRL_ID_MASK;
 778         id++;   /* select next control */
 779         /* find first class that matches (or is greater than) the class of
 780            the ID */
 781         while (*ctrl_classes && V4L2_CTRL_ID2CLASS(**ctrl_classes) < ctrl_class)
 782                 ctrl_classes++;
 783         /* no more classes */
 784         if (*ctrl_classes == NULL)
 785                 return 0;
 786         pctrl = *ctrl_classes;
 787         /* find first ctrl within the class that is >= ID */
 788         while (*pctrl && *pctrl < id) pctrl++;
 789         if (*pctrl)
 790                 return *pctrl;
 791         /* we are at the end of the controls of the current class. */
 792         /* continue with next class if available */
 793         ctrl_classes++;
 794         if (*ctrl_classes == NULL)
 795                 return 0;
 796         return **ctrl_classes;
 797 }
 798 EXPORT_SYMBOL(v4l2_ctrl_next);
 799
 800 int v4l2_chip_match_host(u32 match_type, u32 match_chip)
 801 {
 802         switch (match_type) {
 803         case V4L2_CHIP_MATCH_HOST:
 804                 return match_chip == 0;
 805         default:
 806                 return 0;
 807         }
 808 }
 809 EXPORT_SYMBOL(v4l2_chip_match_host);
 810
 811 #if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
 812 int v4l2_chip_match_i2c_client(struct i2c_client *c, u32 match_type, u32 match_chip)
 813 {
 814         switch (match_type) {
 815         case V4L2_CHIP_MATCH_I2C_DRIVER:
 816                 return (c != NULL && c->driver != NULL && c->driver->id == match_chip);
 817         case V4L2_CHIP_MATCH_I2C_ADDR:
 818                 return (c != NULL && c->addr == match_chip);
 819         default:
 820                 return 0;
 821         }
 822 }
 823 EXPORT_SYMBOL(v4l2_chip_match_i2c_client);
 824
 825 int v4l2_chip_ident_i2c_client(struct i2c_client *c, struct v4l2_chip_ident *chip,
 826                 u32 ident, u32 revision)
 827 {
 828         if (!v4l2_chip_match_i2c_client(c, chip->match_type, chip->match_chip))
 829                 return 0;
 830         if (chip->ident == V4L2_IDENT_NONE) {
 831                 chip->ident = ident;
 832                 chip->revision = revision;
 833         }
 834         else {
 835                 chip->ident = V4L2_IDENT_AMBIGUOUS;
 836                 chip->revision = 0;
 837         }
 838         return 0;
 839 }
 840 EXPORT_SYMBOL(v4l2_chip_ident_i2c_client);
 841
 842 /* ----------------------------------------------------------------- */
 843
 844 /* Helper function for I2C legacy drivers */
 845
 846 int v4l2_i2c_attach(struct i2c_adapter *adapter, int address, struct i2c_driver *driver,
 847                 const char *name,
 848                 int (*probe)(struct i2c_client *, const struct i2c_device_id *))
 849 {
 850         struct i2c_client *client;
 851         int err;
 852
 853         client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
 854         if (!client)
 855                 return -ENOMEM;
 856
 857         client->addr = address;
 858         client->adapter = adapter;
 859         client->driver = driver;
 860         strlcpy(client->name, name, sizeof(client->name));
 861
 862         err = probe(client, NULL);
 863         if (err == 0) {
 864                 i2c_attach_client(client);
 865         } else {
 866                 kfree(client);
 867         }
 868         return err != -ENOMEM ? 0 : err;
 869 }
 870 EXPORT_SYMBOL(v4l2_i2c_attach);
 871
 872 void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client,
 873                 const struct v4l2_subdev_ops *ops)
 874 {
 875         v4l2_subdev_init(sd, ops);
 876         /* the owner is the same as the i2c_client's driver owner */
 877         sd->owner = client->driver->driver.owner;
 878         /* i2c_client and v4l2_subdev point to one another */
 879         v4l2_set_subdevdata(sd, client);
 880         i2c_set_clientdata(client, sd);
 881         /* initialize name */
 882         snprintf(sd->name, sizeof(sd->name), "%s %d-%04x",
 883                 client->driver->driver.name, i2c_adapter_id(client->adapter),
 884                 client->addr);
 885 }
 886 EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_init);
 887
 888
 889
 890 /* Load an i2c sub-device. It assumes that i2c_get_adapdata(adapter)
 891    returns the v4l2_device and that i2c_get_clientdata(client)
 892    returns the v4l2_subdev. */
 893 struct v4l2_subdev *v4l2_i2c_new_subdev(struct i2c_adapter *adapter,
 894                 const char *module_name, const char *client_type, u8 addr)
 895 {
 896         struct v4l2_device *dev = i2c_get_adapdata(adapter);
 897         struct v4l2_subdev *sd = NULL;
 898         struct i2c_client *client;
 899         struct i2c_board_info info;
 900
 901         BUG_ON(!dev);
 902 #ifdef MODULE
 903         if (module_name)
 904                 request_module(module_name);
 905 #endif
 906         /* Setup the i2c board info with the device type and
 907            the device address. */
 908         memset(&info, 0, sizeof(info));
 909         strlcpy(info.type, client_type, sizeof(info.type));
 910         info.addr = addr;
 911
 912         /* Create the i2c client */
 913         client = i2c_new_device(adapter, &info);
 914         /* Note: it is possible in the future that
 915            c->driver is NULL if the driver is still being loaded.
 916            We need better support from the kernel so that we
 917            can easily wait for the load to finish. */
 918         if (client == NULL || client->driver == NULL)
 919                 return NULL;
 920
 921         /* Lock the module so we can safely get the v4l2_subdev pointer */
 922         if (!try_module_get(client->driver->driver.owner))
 923                 return NULL;
 924         sd = i2c_get_clientdata(client);
 925
 926         /* Register with the v4l2_device which increases the module's
 927            use count as well. */
 928         if (v4l2_device_register_subdev(dev, sd))
 929                 sd = NULL;
 930         /* Decrease the module use count to match the first try_module_get. */
 931         module_put(client->driver->driver.owner);
 932         return sd;
 933
 934 }
 935 EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev);
 936
 937 /* Probe and load an i2c sub-device. It assumes that i2c_get_adapdata(adapter)
 938    returns the v4l2_device and that i2c_get_clientdata(client)
 939    returns the v4l2_subdev. */
 940 struct v4l2_subdev *v4l2_i2c_new_probed_subdev(struct i2c_adapter *adapter,
 941         const char *module_name, const char *client_type,
 942         const unsigned short *addrs)
 943 {
 944         struct v4l2_device *dev = i2c_get_adapdata(adapter);
 945         struct v4l2_subdev *sd = NULL;
 946         struct i2c_client *client = NULL;
 947         struct i2c_board_info info;
 948
 949         BUG_ON(!dev);
 950 #ifdef MODULE
 951         if (module_name)
 952                 request_module(module_name);
 953 #endif
 954         /* Setup the i2c board info with the device type and
 955            the device address. */
 956         memset(&info, 0, sizeof(info));
 957         strlcpy(info.type, client_type, sizeof(info.type));
 958
 959         /* Probe and create the i2c client */
 960         client = i2c_new_probed_device(adapter, &info, addrs);
 961         /* Note: it is possible in the future that
 962            c->driver is NULL if the driver is still being loaded.
 963            We need better support from the kernel so that we
 964            can easily wait for the load to finish. */
 965         if (client == NULL || client->driver == NULL)
 966                 return NULL;
 967
 968         /* Lock the module so we can safely get the v4l2_subdev pointer */
 969         if (!try_module_get(client->driver->driver.owner))
 970                 return NULL;
 971         sd = i2c_get_clientdata(client);
 972
 973         /* Register with the v4l2_device which increases the module's
 974            use count as well. */
 975         if (v4l2_device_register_subdev(dev, sd))
 976                 sd = NULL;
 977         /* Decrease the module use count to match the first try_module_get. */
 978         module_put(client->driver->driver.owner);
 979         return sd;
 980 }
 981 EXPORT_SYMBOL_GPL(v4l2_i2c_new_probed_subdev);
 982
 983 #endif