2 V4L2 controls framework implementation.
4 Copyright (C) 2010 Hans Verkuil <hverkuil@xs4all.nl>
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 #include <linux/ctype.h>
22 #include <linux/slab.h>
23 #include <media/v4l2-ioctl.h>
24 #include <media/v4l2-device.h>
25 #include <media/v4l2-ctrls.h>
26 #include <media/v4l2-dev.h>
28 /* Internal temporary helper struct, one for each v4l2_ext_control */
30 /* The control corresponding to the v4l2_ext_control ID field. */
31 struct v4l2_ctrl *ctrl;
32 /* Used internally to mark whether this control was already
37 /* Returns NULL or a character pointer array containing the menu for
38 the given control ID. The pointer array ends with a NULL pointer.
39 An empty string signifies a menu entry that is invalid. This allows
40 drivers to disable certain options if it is not supported. */
41 const char * const *v4l2_ctrl_get_menu(u32 id)
43 static const char * const mpeg_audio_sampling_freq[] = {
49 static const char * const mpeg_audio_encoding[] = {
57 static const char * const mpeg_audio_l1_bitrate[] = {
74 static const char * const mpeg_audio_l2_bitrate[] = {
91 static const char * const mpeg_audio_l3_bitrate[] = {
108 static const char * const mpeg_audio_ac3_bitrate[] = {
130 static const char * const mpeg_audio_mode[] = {
137 static const char * const mpeg_audio_mode_extension[] = {
144 static const char * const mpeg_audio_emphasis[] = {
150 static const char * const mpeg_audio_crc[] = {
155 static const char * const mpeg_video_encoding[] = {
161 static const char * const mpeg_video_aspect[] = {
168 static const char * const mpeg_video_bitrate_mode[] = {
173 static const char * const mpeg_stream_type[] = {
174 "MPEG-2 Program Stream",
175 "MPEG-2 Transport Stream",
176 "MPEG-1 System Stream",
177 "MPEG-2 DVD-compatible Stream",
178 "MPEG-1 VCD-compatible Stream",
179 "MPEG-2 SVCD-compatible Stream",
182 static const char * const mpeg_stream_vbi_fmt[] = {
184 "Private packet, IVTV format",
187 static const char * const camera_power_line_frequency[] = {
193 static const char * const camera_exposure_auto[] = {
196 "Shutter Priority Mode",
197 "Aperture Priority Mode",
200 static const char * const colorfx[] = {
213 static const char * const tune_preemphasis[] = {
221 case V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ:
222 return mpeg_audio_sampling_freq;
223 case V4L2_CID_MPEG_AUDIO_ENCODING:
224 return mpeg_audio_encoding;
225 case V4L2_CID_MPEG_AUDIO_L1_BITRATE:
226 return mpeg_audio_l1_bitrate;
227 case V4L2_CID_MPEG_AUDIO_L2_BITRATE:
228 return mpeg_audio_l2_bitrate;
229 case V4L2_CID_MPEG_AUDIO_L3_BITRATE:
230 return mpeg_audio_l3_bitrate;
231 case V4L2_CID_MPEG_AUDIO_AC3_BITRATE:
232 return mpeg_audio_ac3_bitrate;
233 case V4L2_CID_MPEG_AUDIO_MODE:
234 return mpeg_audio_mode;
235 case V4L2_CID_MPEG_AUDIO_MODE_EXTENSION:
236 return mpeg_audio_mode_extension;
237 case V4L2_CID_MPEG_AUDIO_EMPHASIS:
238 return mpeg_audio_emphasis;
239 case V4L2_CID_MPEG_AUDIO_CRC:
240 return mpeg_audio_crc;
241 case V4L2_CID_MPEG_VIDEO_ENCODING:
242 return mpeg_video_encoding;
243 case V4L2_CID_MPEG_VIDEO_ASPECT:
244 return mpeg_video_aspect;
245 case V4L2_CID_MPEG_VIDEO_BITRATE_MODE:
246 return mpeg_video_bitrate_mode;
247 case V4L2_CID_MPEG_STREAM_TYPE:
248 return mpeg_stream_type;
249 case V4L2_CID_MPEG_STREAM_VBI_FMT:
250 return mpeg_stream_vbi_fmt;
251 case V4L2_CID_POWER_LINE_FREQUENCY:
252 return camera_power_line_frequency;
253 case V4L2_CID_EXPOSURE_AUTO:
254 return camera_exposure_auto;
255 case V4L2_CID_COLORFX:
257 case V4L2_CID_TUNE_PREEMPHASIS:
258 return tune_preemphasis;
263 EXPORT_SYMBOL(v4l2_ctrl_get_menu);
265 /* Return the control name. */
266 const char *v4l2_ctrl_get_name(u32 id)
270 /* Keep the order of the 'case's the same as in videodev2.h! */
271 case V4L2_CID_USER_CLASS: return "User Controls";
272 case V4L2_CID_BRIGHTNESS: return "Brightness";
273 case V4L2_CID_CONTRAST: return "Contrast";
274 case V4L2_CID_SATURATION: return "Saturation";
275 case V4L2_CID_HUE: return "Hue";
276 case V4L2_CID_AUDIO_VOLUME: return "Volume";
277 case V4L2_CID_AUDIO_BALANCE: return "Balance";
278 case V4L2_CID_AUDIO_BASS: return "Bass";
279 case V4L2_CID_AUDIO_TREBLE: return "Treble";
280 case V4L2_CID_AUDIO_MUTE: return "Mute";
281 case V4L2_CID_AUDIO_LOUDNESS: return "Loudness";
282 case V4L2_CID_BLACK_LEVEL: return "Black Level";
283 case V4L2_CID_AUTO_WHITE_BALANCE: return "White Balance, Automatic";
284 case V4L2_CID_DO_WHITE_BALANCE: return "Do White Balance";
285 case V4L2_CID_RED_BALANCE: return "Red Balance";
286 case V4L2_CID_BLUE_BALANCE: return "Blue Balance";
287 case V4L2_CID_GAMMA: return "Gamma";
288 case V4L2_CID_EXPOSURE: return "Exposure";
289 case V4L2_CID_AUTOGAIN: return "Gain, Automatic";
290 case V4L2_CID_GAIN: return "Gain";
291 case V4L2_CID_HFLIP: return "Horizontal Flip";
292 case V4L2_CID_VFLIP: return "Vertical Flip";
293 case V4L2_CID_HCENTER: return "Horizontal Center";
294 case V4L2_CID_VCENTER: return "Vertical Center";
295 case V4L2_CID_POWER_LINE_FREQUENCY: return "Power Line Frequency";
296 case V4L2_CID_HUE_AUTO: return "Hue, Automatic";
297 case V4L2_CID_WHITE_BALANCE_TEMPERATURE: return "White Balance Temperature";
298 case V4L2_CID_SHARPNESS: return "Sharpness";
299 case V4L2_CID_BACKLIGHT_COMPENSATION: return "Backlight Compensation";
300 case V4L2_CID_CHROMA_AGC: return "Chroma AGC";
301 case V4L2_CID_COLOR_KILLER: return "Color Killer";
302 case V4L2_CID_COLORFX: return "Color Effects";
303 case V4L2_CID_AUTOBRIGHTNESS: return "Brightness, Automatic";
304 case V4L2_CID_BAND_STOP_FILTER: return "Band-Stop Filter";
305 case V4L2_CID_ROTATE: return "Rotate";
306 case V4L2_CID_BG_COLOR: return "Background Color";
307 case V4L2_CID_CHROMA_GAIN: return "Chroma Gain";
308 case V4L2_CID_ILLUMINATORS_1: return "Illuminator 1";
309 case V4L2_CID_ILLUMINATORS_2: return "Illuminator 2";
312 /* Keep the order of the 'case's the same as in videodev2.h! */
313 case V4L2_CID_MPEG_CLASS: return "MPEG Encoder Controls";
314 case V4L2_CID_MPEG_STREAM_TYPE: return "Stream Type";
315 case V4L2_CID_MPEG_STREAM_PID_PMT: return "Stream PMT Program ID";
316 case V4L2_CID_MPEG_STREAM_PID_AUDIO: return "Stream Audio Program ID";
317 case V4L2_CID_MPEG_STREAM_PID_VIDEO: return "Stream Video Program ID";
318 case V4L2_CID_MPEG_STREAM_PID_PCR: return "Stream PCR Program ID";
319 case V4L2_CID_MPEG_STREAM_PES_ID_AUDIO: return "Stream PES Audio ID";
320 case V4L2_CID_MPEG_STREAM_PES_ID_VIDEO: return "Stream PES Video ID";
321 case V4L2_CID_MPEG_STREAM_VBI_FMT: return "Stream VBI Format";
322 case V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ: return "Audio Sampling Frequency";
323 case V4L2_CID_MPEG_AUDIO_ENCODING: return "Audio Encoding";
324 case V4L2_CID_MPEG_AUDIO_L1_BITRATE: return "Audio Layer I Bitrate";
325 case V4L2_CID_MPEG_AUDIO_L2_BITRATE: return "Audio Layer II Bitrate";
326 case V4L2_CID_MPEG_AUDIO_L3_BITRATE: return "Audio Layer III Bitrate";
327 case V4L2_CID_MPEG_AUDIO_MODE: return "Audio Stereo Mode";
328 case V4L2_CID_MPEG_AUDIO_MODE_EXTENSION: return "Audio Stereo Mode Extension";
329 case V4L2_CID_MPEG_AUDIO_EMPHASIS: return "Audio Emphasis";
330 case V4L2_CID_MPEG_AUDIO_CRC: return "Audio CRC";
331 case V4L2_CID_MPEG_AUDIO_MUTE: return "Audio Mute";
332 case V4L2_CID_MPEG_AUDIO_AAC_BITRATE: return "Audio AAC Bitrate";
333 case V4L2_CID_MPEG_AUDIO_AC3_BITRATE: return "Audio AC-3 Bitrate";
334 case V4L2_CID_MPEG_VIDEO_ENCODING: return "Video Encoding";
335 case V4L2_CID_MPEG_VIDEO_ASPECT: return "Video Aspect";
336 case V4L2_CID_MPEG_VIDEO_B_FRAMES: return "Video B Frames";
337 case V4L2_CID_MPEG_VIDEO_GOP_SIZE: return "Video GOP Size";
338 case V4L2_CID_MPEG_VIDEO_GOP_CLOSURE: return "Video GOP Closure";
339 case V4L2_CID_MPEG_VIDEO_PULLDOWN: return "Video Pulldown";
340 case V4L2_CID_MPEG_VIDEO_BITRATE_MODE: return "Video Bitrate Mode";
341 case V4L2_CID_MPEG_VIDEO_BITRATE: return "Video Bitrate";
342 case V4L2_CID_MPEG_VIDEO_BITRATE_PEAK: return "Video Peak Bitrate";
343 case V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION: return "Video Temporal Decimation";
344 case V4L2_CID_MPEG_VIDEO_MUTE: return "Video Mute";
345 case V4L2_CID_MPEG_VIDEO_MUTE_YUV: return "Video Mute YUV";
347 /* CAMERA controls */
348 /* Keep the order of the 'case's the same as in videodev2.h! */
349 case V4L2_CID_CAMERA_CLASS: return "Camera Controls";
350 case V4L2_CID_EXPOSURE_AUTO: return "Auto Exposure";
351 case V4L2_CID_EXPOSURE_ABSOLUTE: return "Exposure Time, Absolute";
352 case V4L2_CID_EXPOSURE_AUTO_PRIORITY: return "Exposure, Dynamic Framerate";
353 case V4L2_CID_PAN_RELATIVE: return "Pan, Relative";
354 case V4L2_CID_TILT_RELATIVE: return "Tilt, Relative";
355 case V4L2_CID_PAN_RESET: return "Pan, Reset";
356 case V4L2_CID_TILT_RESET: return "Tilt, Reset";
357 case V4L2_CID_PAN_ABSOLUTE: return "Pan, Absolute";
358 case V4L2_CID_TILT_ABSOLUTE: return "Tilt, Absolute";
359 case V4L2_CID_FOCUS_ABSOLUTE: return "Focus, Absolute";
360 case V4L2_CID_FOCUS_RELATIVE: return "Focus, Relative";
361 case V4L2_CID_FOCUS_AUTO: return "Focus, Automatic";
362 case V4L2_CID_ZOOM_ABSOLUTE: return "Zoom, Absolute";
363 case V4L2_CID_ZOOM_RELATIVE: return "Zoom, Relative";
364 case V4L2_CID_ZOOM_CONTINUOUS: return "Zoom, Continuous";
365 case V4L2_CID_PRIVACY: return "Privacy";
366 case V4L2_CID_IRIS_ABSOLUTE: return "Iris, Absolute";
367 case V4L2_CID_IRIS_RELATIVE: return "Iris, Relative";
369 /* FM Radio Modulator control */
370 /* Keep the order of the 'case's the same as in videodev2.h! */
371 case V4L2_CID_FM_TX_CLASS: return "FM Radio Modulator Controls";
372 case V4L2_CID_RDS_TX_DEVIATION: return "RDS Signal Deviation";
373 case V4L2_CID_RDS_TX_PI: return "RDS Program ID";
374 case V4L2_CID_RDS_TX_PTY: return "RDS Program Type";
375 case V4L2_CID_RDS_TX_PS_NAME: return "RDS PS Name";
376 case V4L2_CID_RDS_TX_RADIO_TEXT: return "RDS Radio Text";
377 case V4L2_CID_AUDIO_LIMITER_ENABLED: return "Audio Limiter Feature Enabled";
378 case V4L2_CID_AUDIO_LIMITER_RELEASE_TIME: return "Audio Limiter Release Time";
379 case V4L2_CID_AUDIO_LIMITER_DEVIATION: return "Audio Limiter Deviation";
380 case V4L2_CID_AUDIO_COMPRESSION_ENABLED: return "Audio Compression Feature Enabled";
381 case V4L2_CID_AUDIO_COMPRESSION_GAIN: return "Audio Compression Gain";
382 case V4L2_CID_AUDIO_COMPRESSION_THRESHOLD: return "Audio Compression Threshold";
383 case V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME: return "Audio Compression Attack Time";
384 case V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME: return "Audio Compression Release Time";
385 case V4L2_CID_PILOT_TONE_ENABLED: return "Pilot Tone Feature Enabled";
386 case V4L2_CID_PILOT_TONE_DEVIATION: return "Pilot Tone Deviation";
387 case V4L2_CID_PILOT_TONE_FREQUENCY: return "Pilot Tone Frequency";
388 case V4L2_CID_TUNE_PREEMPHASIS: return "Pre-emphasis settings";
389 case V4L2_CID_TUNE_POWER_LEVEL: return "Tune Power Level";
390 case V4L2_CID_TUNE_ANTENNA_CAPACITOR: return "Tune Antenna Capacitor";
396 EXPORT_SYMBOL(v4l2_ctrl_get_name);
398 void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
399 s32 *min, s32 *max, s32 *step, s32 *def, u32 *flags)
401 *name = v4l2_ctrl_get_name(id);
405 case V4L2_CID_AUDIO_MUTE:
406 case V4L2_CID_AUDIO_LOUDNESS:
407 case V4L2_CID_AUTO_WHITE_BALANCE:
408 case V4L2_CID_AUTOGAIN:
411 case V4L2_CID_HUE_AUTO:
412 case V4L2_CID_CHROMA_AGC:
413 case V4L2_CID_COLOR_KILLER:
414 case V4L2_CID_MPEG_AUDIO_MUTE:
415 case V4L2_CID_MPEG_VIDEO_MUTE:
416 case V4L2_CID_MPEG_VIDEO_GOP_CLOSURE:
417 case V4L2_CID_MPEG_VIDEO_PULLDOWN:
418 case V4L2_CID_EXPOSURE_AUTO_PRIORITY:
419 case V4L2_CID_FOCUS_AUTO:
420 case V4L2_CID_PRIVACY:
421 case V4L2_CID_AUDIO_LIMITER_ENABLED:
422 case V4L2_CID_AUDIO_COMPRESSION_ENABLED:
423 case V4L2_CID_PILOT_TONE_ENABLED:
424 case V4L2_CID_ILLUMINATORS_1:
425 case V4L2_CID_ILLUMINATORS_2:
426 *type = V4L2_CTRL_TYPE_BOOLEAN;
430 case V4L2_CID_PAN_RESET:
431 case V4L2_CID_TILT_RESET:
432 *type = V4L2_CTRL_TYPE_BUTTON;
433 *flags |= V4L2_CTRL_FLAG_WRITE_ONLY;
434 *min = *max = *step = *def = 0;
436 case V4L2_CID_POWER_LINE_FREQUENCY:
437 case V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ:
438 case V4L2_CID_MPEG_AUDIO_ENCODING:
439 case V4L2_CID_MPEG_AUDIO_L1_BITRATE:
440 case V4L2_CID_MPEG_AUDIO_L2_BITRATE:
441 case V4L2_CID_MPEG_AUDIO_L3_BITRATE:
442 case V4L2_CID_MPEG_AUDIO_AC3_BITRATE:
443 case V4L2_CID_MPEG_AUDIO_MODE:
444 case V4L2_CID_MPEG_AUDIO_MODE_EXTENSION:
445 case V4L2_CID_MPEG_AUDIO_EMPHASIS:
446 case V4L2_CID_MPEG_AUDIO_CRC:
447 case V4L2_CID_MPEG_VIDEO_ENCODING:
448 case V4L2_CID_MPEG_VIDEO_ASPECT:
449 case V4L2_CID_MPEG_VIDEO_BITRATE_MODE:
450 case V4L2_CID_MPEG_STREAM_TYPE:
451 case V4L2_CID_MPEG_STREAM_VBI_FMT:
452 case V4L2_CID_EXPOSURE_AUTO:
453 case V4L2_CID_COLORFX:
454 case V4L2_CID_TUNE_PREEMPHASIS:
455 *type = V4L2_CTRL_TYPE_MENU;
457 case V4L2_CID_RDS_TX_PS_NAME:
458 case V4L2_CID_RDS_TX_RADIO_TEXT:
459 *type = V4L2_CTRL_TYPE_STRING;
461 case V4L2_CID_USER_CLASS:
462 case V4L2_CID_CAMERA_CLASS:
463 case V4L2_CID_MPEG_CLASS:
464 case V4L2_CID_FM_TX_CLASS:
465 *type = V4L2_CTRL_TYPE_CTRL_CLASS;
466 /* You can neither read not write these */
467 *flags |= V4L2_CTRL_FLAG_READ_ONLY | V4L2_CTRL_FLAG_WRITE_ONLY;
468 *min = *max = *step = *def = 0;
470 case V4L2_CID_BG_COLOR:
471 *type = V4L2_CTRL_TYPE_INTEGER;
474 /* Max is calculated as RGB888 that is 2^24 */
478 *type = V4L2_CTRL_TYPE_INTEGER;
482 case V4L2_CID_MPEG_AUDIO_ENCODING:
483 case V4L2_CID_MPEG_AUDIO_MODE:
484 case V4L2_CID_MPEG_VIDEO_BITRATE_MODE:
485 case V4L2_CID_MPEG_VIDEO_B_FRAMES:
486 case V4L2_CID_MPEG_STREAM_TYPE:
487 *flags |= V4L2_CTRL_FLAG_UPDATE;
489 case V4L2_CID_AUDIO_VOLUME:
490 case V4L2_CID_AUDIO_BALANCE:
491 case V4L2_CID_AUDIO_BASS:
492 case V4L2_CID_AUDIO_TREBLE:
493 case V4L2_CID_BRIGHTNESS:
494 case V4L2_CID_CONTRAST:
495 case V4L2_CID_SATURATION:
497 case V4L2_CID_RED_BALANCE:
498 case V4L2_CID_BLUE_BALANCE:
500 case V4L2_CID_SHARPNESS:
501 case V4L2_CID_CHROMA_GAIN:
502 case V4L2_CID_RDS_TX_DEVIATION:
503 case V4L2_CID_AUDIO_LIMITER_RELEASE_TIME:
504 case V4L2_CID_AUDIO_LIMITER_DEVIATION:
505 case V4L2_CID_AUDIO_COMPRESSION_GAIN:
506 case V4L2_CID_AUDIO_COMPRESSION_THRESHOLD:
507 case V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME:
508 case V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME:
509 case V4L2_CID_PILOT_TONE_DEVIATION:
510 case V4L2_CID_PILOT_TONE_FREQUENCY:
511 case V4L2_CID_TUNE_POWER_LEVEL:
512 case V4L2_CID_TUNE_ANTENNA_CAPACITOR:
513 *flags |= V4L2_CTRL_FLAG_SLIDER;
515 case V4L2_CID_PAN_RELATIVE:
516 case V4L2_CID_TILT_RELATIVE:
517 case V4L2_CID_FOCUS_RELATIVE:
518 case V4L2_CID_IRIS_RELATIVE:
519 case V4L2_CID_ZOOM_RELATIVE:
520 *flags |= V4L2_CTRL_FLAG_WRITE_ONLY;
524 EXPORT_SYMBOL(v4l2_ctrl_fill);
526 /* Helper function to determine whether the control type is compatible with
528 static bool type_is_int(const struct v4l2_ctrl *ctrl)
530 switch (ctrl->type) {
531 case V4L2_CTRL_TYPE_INTEGER64:
532 case V4L2_CTRL_TYPE_STRING:
533 /* Nope, these need v4l2_ext_control */
540 /* Helper function: copy the current control value back to the caller */
541 static int cur_to_user(struct v4l2_ext_control *c,
542 struct v4l2_ctrl *ctrl)
546 switch (ctrl->type) {
547 case V4L2_CTRL_TYPE_STRING:
548 len = strlen(ctrl->cur.string);
549 if (c->size < len + 1) {
553 return copy_to_user(c->string, ctrl->cur.string,
554 len + 1) ? -EFAULT : 0;
555 case V4L2_CTRL_TYPE_INTEGER64:
556 c->value64 = ctrl->cur.val64;
559 c->value = ctrl->cur.val;
565 /* Helper function: copy the caller-provider value as the new control value */
566 static int user_to_new(struct v4l2_ext_control *c,
567 struct v4l2_ctrl *ctrl)
573 switch (ctrl->type) {
574 case V4L2_CTRL_TYPE_INTEGER64:
575 ctrl->val64 = c->value64;
577 case V4L2_CTRL_TYPE_STRING:
581 if (size > ctrl->maximum + 1)
582 size = ctrl->maximum + 1;
583 ret = copy_from_user(ctrl->string, c->string, size);
585 char last = ctrl->string[size - 1];
587 ctrl->string[size - 1] = 0;
588 /* If the string was longer than ctrl->maximum,
589 then return an error. */
590 if (strlen(ctrl->string) == ctrl->maximum && last)
593 return ret ? -EFAULT : 0;
595 ctrl->val = c->value;
601 /* Helper function: copy the new control value back to the caller */
602 static int new_to_user(struct v4l2_ext_control *c,
603 struct v4l2_ctrl *ctrl)
607 switch (ctrl->type) {
608 case V4L2_CTRL_TYPE_STRING:
609 len = strlen(ctrl->string);
610 if (c->size < len + 1) {
611 c->size = ctrl->maximum + 1;
614 return copy_to_user(c->string, ctrl->string,
615 len + 1) ? -EFAULT : 0;
616 case V4L2_CTRL_TYPE_INTEGER64:
617 c->value64 = ctrl->val64;
620 c->value = ctrl->val;
626 /* Copy the new value to the current value. */
627 static void new_to_cur(struct v4l2_ctrl *ctrl)
631 switch (ctrl->type) {
632 case V4L2_CTRL_TYPE_STRING:
633 /* strings are always 0-terminated */
634 strcpy(ctrl->cur.string, ctrl->string);
636 case V4L2_CTRL_TYPE_INTEGER64:
637 ctrl->cur.val64 = ctrl->val64;
640 ctrl->cur.val = ctrl->val;
645 /* Copy the current value to the new value */
646 static void cur_to_new(struct v4l2_ctrl *ctrl)
650 switch (ctrl->type) {
651 case V4L2_CTRL_TYPE_STRING:
652 /* strings are always 0-terminated */
653 strcpy(ctrl->string, ctrl->cur.string);
655 case V4L2_CTRL_TYPE_INTEGER64:
656 ctrl->val64 = ctrl->cur.val64;
659 ctrl->val = ctrl->cur.val;
664 /* Return non-zero if one or more of the controls in the cluster has a new
665 value that differs from the current value. */
666 static int cluster_changed(struct v4l2_ctrl *master)
671 for (i = 0; !diff && i < master->ncontrols; i++) {
672 struct v4l2_ctrl *ctrl = master->cluster[i];
676 switch (ctrl->type) {
677 case V4L2_CTRL_TYPE_BUTTON:
678 /* Button controls are always 'different' */
680 case V4L2_CTRL_TYPE_STRING:
681 /* strings are always 0-terminated */
682 diff = strcmp(ctrl->string, ctrl->cur.string);
684 case V4L2_CTRL_TYPE_INTEGER64:
685 diff = ctrl->val64 != ctrl->cur.val64;
688 diff = ctrl->val != ctrl->cur.val;
695 /* Validate a new control */
696 static int validate_new(struct v4l2_ctrl *ctrl)
699 char *s = ctrl->string;
703 switch (ctrl->type) {
704 case V4L2_CTRL_TYPE_INTEGER:
705 /* Round towards the closest legal value */
706 val += ctrl->step / 2;
707 if (val < ctrl->minimum)
709 if (val > ctrl->maximum)
711 offset = val - ctrl->minimum;
712 offset = ctrl->step * (offset / ctrl->step);
713 val = ctrl->minimum + offset;
717 case V4L2_CTRL_TYPE_BOOLEAN:
718 ctrl->val = !!ctrl->val;
721 case V4L2_CTRL_TYPE_MENU:
722 if (val < ctrl->minimum || val > ctrl->maximum)
724 if (ctrl->qmenu[val][0] == '\0' ||
725 (ctrl->menu_skip_mask & (1 << val)))
729 case V4L2_CTRL_TYPE_BUTTON:
730 case V4L2_CTRL_TYPE_CTRL_CLASS:
734 case V4L2_CTRL_TYPE_INTEGER64:
737 case V4L2_CTRL_TYPE_STRING:
739 if (len < ctrl->minimum)
741 if ((len - ctrl->minimum) % ctrl->step)
750 static inline u32 node2id(struct list_head *node)
752 return list_entry(node, struct v4l2_ctrl_ref, node)->ctrl->id;
755 /* Set the handler's error code if it wasn't set earlier already */
756 static inline int handler_set_err(struct v4l2_ctrl_handler *hdl, int err)
763 /* Initialize the handler */
764 int v4l2_ctrl_handler_init(struct v4l2_ctrl_handler *hdl,
765 unsigned nr_of_controls_hint)
767 mutex_init(&hdl->lock);
768 INIT_LIST_HEAD(&hdl->ctrls);
769 INIT_LIST_HEAD(&hdl->ctrl_refs);
770 hdl->nr_of_buckets = 1 + nr_of_controls_hint / 8;
771 hdl->buckets = kzalloc(sizeof(hdl->buckets[0]) * hdl->nr_of_buckets,
773 hdl->error = hdl->buckets ? 0 : -ENOMEM;
776 EXPORT_SYMBOL(v4l2_ctrl_handler_init);
778 /* Free all controls and control refs */
779 void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl)
781 struct v4l2_ctrl_ref *ref, *next_ref;
782 struct v4l2_ctrl *ctrl, *next_ctrl;
784 if (hdl == NULL || hdl->buckets == NULL)
787 mutex_lock(&hdl->lock);
789 list_for_each_entry_safe(ref, next_ref, &hdl->ctrl_refs, node) {
790 list_del(&ref->node);
793 /* Free all controls owned by the handler */
794 list_for_each_entry_safe(ctrl, next_ctrl, &hdl->ctrls, node) {
795 list_del(&ctrl->node);
802 mutex_unlock(&hdl->lock);
804 EXPORT_SYMBOL(v4l2_ctrl_handler_free);
806 /* For backwards compatibility: V4L2_CID_PRIVATE_BASE should no longer
807 be used except in G_CTRL, S_CTRL, QUERYCTRL and QUERYMENU when dealing
808 with applications that do not use the NEXT_CTRL flag.
810 We just find the n-th private user control. It's O(N), but that should not
811 be an issue in this particular case. */
812 static struct v4l2_ctrl_ref *find_private_ref(
813 struct v4l2_ctrl_handler *hdl, u32 id)
815 struct v4l2_ctrl_ref *ref;
817 id -= V4L2_CID_PRIVATE_BASE;
818 list_for_each_entry(ref, &hdl->ctrl_refs, node) {
819 /* Search for private user controls that are compatible with
821 if (V4L2_CTRL_ID2CLASS(ref->ctrl->id) == V4L2_CTRL_CLASS_USER &&
822 V4L2_CTRL_DRIVER_PRIV(ref->ctrl->id)) {
823 if (!type_is_int(ref->ctrl))
833 /* Find a control with the given ID. */
834 static struct v4l2_ctrl_ref *find_ref(struct v4l2_ctrl_handler *hdl, u32 id)
836 struct v4l2_ctrl_ref *ref;
839 id &= V4L2_CTRL_ID_MASK;
841 /* Old-style private controls need special handling */
842 if (id >= V4L2_CID_PRIVATE_BASE)
843 return find_private_ref(hdl, id);
844 bucket = id % hdl->nr_of_buckets;
846 /* Simple optimization: cache the last control found */
847 if (hdl->cached && hdl->cached->ctrl->id == id)
850 /* Not in cache, search the hash */
851 ref = hdl->buckets ? hdl->buckets[bucket] : NULL;
852 while (ref && ref->ctrl->id != id)
856 hdl->cached = ref; /* cache it! */
860 /* Find a control with the given ID. Take the handler's lock first. */
861 static struct v4l2_ctrl_ref *find_ref_lock(
862 struct v4l2_ctrl_handler *hdl, u32 id)
864 struct v4l2_ctrl_ref *ref = NULL;
867 mutex_lock(&hdl->lock);
868 ref = find_ref(hdl, id);
869 mutex_unlock(&hdl->lock);
874 /* Find a control with the given ID. */
875 struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id)
877 struct v4l2_ctrl_ref *ref = find_ref_lock(hdl, id);
879 return ref ? ref->ctrl : NULL;
881 EXPORT_SYMBOL(v4l2_ctrl_find);
883 /* Allocate a new v4l2_ctrl_ref and hook it into the handler. */
884 static int handler_new_ref(struct v4l2_ctrl_handler *hdl,
885 struct v4l2_ctrl *ctrl)
887 struct v4l2_ctrl_ref *ref;
888 struct v4l2_ctrl_ref *new_ref;
890 u32 class_ctrl = V4L2_CTRL_ID2CLASS(id) | 1;
891 int bucket = id % hdl->nr_of_buckets; /* which bucket to use */
893 /* Automatically add the control class if it is not yet present. */
894 if (id != class_ctrl && find_ref_lock(hdl, class_ctrl) == NULL)
895 if (!v4l2_ctrl_new_std(hdl, NULL, class_ctrl, 0, 0, 0, 0))
901 new_ref = kzalloc(sizeof(*new_ref), GFP_KERNEL);
903 return handler_set_err(hdl, -ENOMEM);
904 new_ref->ctrl = ctrl;
905 if (ctrl->handler == hdl) {
906 /* By default each control starts in a cluster of its own.
907 new_ref->ctrl is basically a cluster array with one
908 element, so that's perfect to use as the cluster pointer.
909 But only do this for the handler that owns the control. */
910 ctrl->cluster = &new_ref->ctrl;
914 INIT_LIST_HEAD(&new_ref->node);
916 mutex_lock(&hdl->lock);
918 /* Add immediately at the end of the list if the list is empty, or if
919 the last element in the list has a lower ID.
920 This ensures that when elements are added in ascending order the
921 insertion is an O(1) operation. */
922 if (list_empty(&hdl->ctrl_refs) || id > node2id(hdl->ctrl_refs.prev)) {
923 list_add_tail(&new_ref->node, &hdl->ctrl_refs);
927 /* Find insert position in sorted list */
928 list_for_each_entry(ref, &hdl->ctrl_refs, node) {
929 if (ref->ctrl->id < id)
931 /* Don't add duplicates */
932 if (ref->ctrl->id == id) {
936 list_add(&new_ref->node, ref->node.prev);
941 /* Insert the control node in the hash */
942 new_ref->next = hdl->buckets[bucket];
943 hdl->buckets[bucket] = new_ref;
946 mutex_unlock(&hdl->lock);
950 /* Add a new control */
951 static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
952 const struct v4l2_ctrl_ops *ops,
953 u32 id, const char *name, enum v4l2_ctrl_type type,
954 s32 min, s32 max, u32 step, s32 def,
955 u32 flags, const char * const *qmenu, void *priv)
957 struct v4l2_ctrl *ctrl;
958 unsigned sz_extra = 0;
964 if (id == 0 || name == NULL || id >= V4L2_CID_PRIVATE_BASE ||
966 (type == V4L2_CTRL_TYPE_INTEGER && step == 0) ||
967 (type == V4L2_CTRL_TYPE_MENU && qmenu == NULL) ||
968 (type == V4L2_CTRL_TYPE_STRING && max == 0)) {
969 handler_set_err(hdl, -ERANGE);
972 if ((type == V4L2_CTRL_TYPE_INTEGER ||
973 type == V4L2_CTRL_TYPE_MENU ||
974 type == V4L2_CTRL_TYPE_BOOLEAN) &&
975 (def < min || def > max)) {
976 handler_set_err(hdl, -ERANGE);
980 if (type == V4L2_CTRL_TYPE_BUTTON)
981 flags |= V4L2_CTRL_FLAG_WRITE_ONLY;
982 else if (type == V4L2_CTRL_TYPE_CTRL_CLASS)
983 flags |= V4L2_CTRL_FLAG_READ_ONLY;
984 else if (type == V4L2_CTRL_TYPE_STRING)
985 sz_extra += 2 * (max + 1);
987 ctrl = kzalloc(sizeof(*ctrl) + sz_extra, GFP_KERNEL);
989 handler_set_err(hdl, -ENOMEM);
993 INIT_LIST_HEAD(&ctrl->node);
1000 ctrl->minimum = min;
1001 ctrl->maximum = max;
1003 ctrl->qmenu = qmenu;
1005 ctrl->cur.val = ctrl->val = ctrl->default_value = def;
1007 if (ctrl->type == V4L2_CTRL_TYPE_STRING) {
1008 ctrl->cur.string = (char *)&ctrl[1] + sz_extra - (max + 1);
1009 ctrl->string = (char *)&ctrl[1] + sz_extra - 2 * (max + 1);
1011 memset(ctrl->cur.string, ' ', ctrl->minimum);
1013 if (handler_new_ref(hdl, ctrl)) {
1017 mutex_lock(&hdl->lock);
1018 list_add_tail(&ctrl->node, &hdl->ctrls);
1019 mutex_unlock(&hdl->lock);
1023 struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
1024 const struct v4l2_ctrl_config *cfg, void *priv)
1027 struct v4l2_ctrl *ctrl;
1028 const char *name = cfg->name;
1029 const char * const *qmenu = cfg->qmenu;
1030 enum v4l2_ctrl_type type = cfg->type;
1031 u32 flags = cfg->flags;
1034 u32 step = cfg->step;
1038 v4l2_ctrl_fill(cfg->id, &name, &type, &min, &max, &step,
1041 is_menu = (cfg->type == V4L2_CTRL_TYPE_MENU);
1045 WARN_ON(cfg->menu_skip_mask);
1046 if (is_menu && qmenu == NULL)
1047 qmenu = v4l2_ctrl_get_menu(cfg->id);
1049 ctrl = v4l2_ctrl_new(hdl, cfg->ops, cfg->id, name,
1051 is_menu ? cfg->menu_skip_mask : step,
1052 def, flags, qmenu, priv);
1054 ctrl->is_private = cfg->is_private;
1055 ctrl->is_volatile = cfg->is_volatile;
1059 EXPORT_SYMBOL(v4l2_ctrl_new_custom);
1061 /* Helper function for standard non-menu controls */
1062 struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
1063 const struct v4l2_ctrl_ops *ops,
1064 u32 id, s32 min, s32 max, u32 step, s32 def)
1067 enum v4l2_ctrl_type type;
1070 v4l2_ctrl_fill(id, &name, &type, &min, &max, &step, &def, &flags);
1071 if (type == V4L2_CTRL_TYPE_MENU) {
1072 handler_set_err(hdl, -EINVAL);
1075 return v4l2_ctrl_new(hdl, ops, id, name, type,
1076 min, max, step, def, flags, NULL, NULL);
1078 EXPORT_SYMBOL(v4l2_ctrl_new_std);
1080 /* Helper function for standard menu controls */
1081 struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
1082 const struct v4l2_ctrl_ops *ops,
1083 u32 id, s32 max, s32 mask, s32 def)
1085 const char * const *qmenu = v4l2_ctrl_get_menu(id);
1087 enum v4l2_ctrl_type type;
1092 v4l2_ctrl_fill(id, &name, &type, &min, &max, &step, &def, &flags);
1093 if (type != V4L2_CTRL_TYPE_MENU) {
1094 handler_set_err(hdl, -EINVAL);
1097 return v4l2_ctrl_new(hdl, ops, id, name, type,
1098 0, max, mask, def, flags, qmenu, NULL);
1100 EXPORT_SYMBOL(v4l2_ctrl_new_std_menu);
1102 /* Add a control from another handler to this handler */
1103 struct v4l2_ctrl *v4l2_ctrl_add_ctrl(struct v4l2_ctrl_handler *hdl,
1104 struct v4l2_ctrl *ctrl)
1106 if (hdl == NULL || hdl->error)
1109 handler_set_err(hdl, -EINVAL);
1112 if (ctrl->handler == hdl)
1114 return handler_new_ref(hdl, ctrl) ? NULL : ctrl;
1116 EXPORT_SYMBOL(v4l2_ctrl_add_ctrl);
1118 /* Add the controls from another handler to our own. */
1119 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
1120 struct v4l2_ctrl_handler *add)
1122 struct v4l2_ctrl *ctrl;
1125 /* Do nothing if either handler is NULL or if they are the same */
1126 if (!hdl || !add || hdl == add)
1130 mutex_lock(&add->lock);
1131 list_for_each_entry(ctrl, &add->ctrls, node) {
1132 /* Skip handler-private controls. */
1133 if (ctrl->is_private)
1135 ret = handler_new_ref(hdl, ctrl);
1139 mutex_unlock(&add->lock);
1142 EXPORT_SYMBOL(v4l2_ctrl_add_handler);
1144 /* Cluster controls */
1145 void v4l2_ctrl_cluster(unsigned ncontrols, struct v4l2_ctrl **controls)
1149 /* The first control is the master control and it must not be NULL */
1150 BUG_ON(controls[0] == NULL);
1152 for (i = 0; i < ncontrols; i++) {
1154 controls[i]->cluster = controls;
1155 controls[i]->ncontrols = ncontrols;
1159 EXPORT_SYMBOL(v4l2_ctrl_cluster);
1161 /* Activate/deactivate a control. */
1162 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active)
1168 /* set V4L2_CTRL_FLAG_INACTIVE */
1169 set_bit(4, &ctrl->flags);
1171 /* clear V4L2_CTRL_FLAG_INACTIVE */
1172 clear_bit(4, &ctrl->flags);
1174 EXPORT_SYMBOL(v4l2_ctrl_activate);
1176 /* Grab/ungrab a control.
1177 Typically used when streaming starts and you want to grab controls,
1178 preventing the user from changing them.
1180 Just call this and the framework will block any attempts to change
1182 void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
1188 /* set V4L2_CTRL_FLAG_GRABBED */
1189 set_bit(1, &ctrl->flags);
1191 /* clear V4L2_CTRL_FLAG_GRABBED */
1192 clear_bit(1, &ctrl->flags);
1194 EXPORT_SYMBOL(v4l2_ctrl_grab);
1196 /* Log the control name and value */
1197 static void log_ctrl(const struct v4l2_ctrl *ctrl,
1198 const char *prefix, const char *colon)
1200 int fl_inact = ctrl->flags & V4L2_CTRL_FLAG_INACTIVE;
1201 int fl_grabbed = ctrl->flags & V4L2_CTRL_FLAG_GRABBED;
1203 if (ctrl->flags & (V4L2_CTRL_FLAG_DISABLED | V4L2_CTRL_FLAG_WRITE_ONLY))
1205 if (ctrl->type == V4L2_CTRL_TYPE_CTRL_CLASS)
1208 printk(KERN_INFO "%s%s%s: ", prefix, colon, ctrl->name);
1210 switch (ctrl->type) {
1211 case V4L2_CTRL_TYPE_INTEGER:
1212 printk(KERN_CONT "%d", ctrl->cur.val);
1214 case V4L2_CTRL_TYPE_BOOLEAN:
1215 printk(KERN_CONT "%s", ctrl->cur.val ? "true" : "false");
1217 case V4L2_CTRL_TYPE_MENU:
1218 printk(KERN_CONT "%s", ctrl->qmenu[ctrl->cur.val]);
1220 case V4L2_CTRL_TYPE_INTEGER64:
1221 printk(KERN_CONT "%lld", ctrl->cur.val64);
1223 case V4L2_CTRL_TYPE_STRING:
1224 printk(KERN_CONT "%s", ctrl->cur.string);
1227 printk(KERN_CONT "unknown type %d", ctrl->type);
1230 if (fl_inact && fl_grabbed)
1231 printk(KERN_CONT " (inactive, grabbed)\n");
1233 printk(KERN_CONT " (inactive)\n");
1234 else if (fl_grabbed)
1235 printk(KERN_CONT " (grabbed)\n");
1237 printk(KERN_CONT "\n");
1240 /* Log all controls owned by the handler */
1241 void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
1244 struct v4l2_ctrl *ctrl;
1245 const char *colon = "";
1252 len = strlen(prefix);
1253 if (len && prefix[len - 1] != ' ')
1255 mutex_lock(&hdl->lock);
1256 list_for_each_entry(ctrl, &hdl->ctrls, node)
1257 if (!(ctrl->flags & V4L2_CTRL_FLAG_DISABLED))
1258 log_ctrl(ctrl, prefix, colon);
1259 mutex_unlock(&hdl->lock);
1261 EXPORT_SYMBOL(v4l2_ctrl_handler_log_status);
1263 /* Call s_ctrl for all controls owned by the handler */
1264 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl)
1266 struct v4l2_ctrl *ctrl;
1271 mutex_lock(&hdl->lock);
1272 list_for_each_entry(ctrl, &hdl->ctrls, node)
1275 list_for_each_entry(ctrl, &hdl->ctrls, node) {
1276 struct v4l2_ctrl *master = ctrl->cluster[0];
1279 /* Skip if this control was already handled by a cluster. */
1283 for (i = 0; i < master->ncontrols; i++) {
1284 if (master->cluster[i]) {
1285 cur_to_new(master->cluster[i]);
1286 master->cluster[i]->is_new = 1;
1290 /* Skip button controls and read-only controls. */
1291 if (ctrl->type == V4L2_CTRL_TYPE_BUTTON ||
1292 (ctrl->flags & V4L2_CTRL_FLAG_READ_ONLY))
1294 ret = master->ops->s_ctrl(master);
1297 for (i = 0; i < master->ncontrols; i++)
1298 if (master->cluster[i])
1299 master->cluster[i]->done = true;
1301 mutex_unlock(&hdl->lock);
1304 EXPORT_SYMBOL(v4l2_ctrl_handler_setup);
1306 /* Implement VIDIOC_QUERYCTRL */
1307 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc)
1309 u32 id = qc->id & V4L2_CTRL_ID_MASK;
1310 struct v4l2_ctrl_ref *ref;
1311 struct v4l2_ctrl *ctrl;
1316 mutex_lock(&hdl->lock);
1318 /* Try to find it */
1319 ref = find_ref(hdl, id);
1321 if ((qc->id & V4L2_CTRL_FLAG_NEXT_CTRL) && !list_empty(&hdl->ctrl_refs)) {
1322 /* Find the next control with ID > qc->id */
1324 /* Did we reach the end of the control list? */
1325 if (id >= node2id(hdl->ctrl_refs.prev)) {
1326 ref = NULL; /* Yes, so there is no next control */
1328 /* We found a control with the given ID, so just get
1329 the next one in the list. */
1330 ref = list_entry(ref->node.next, typeof(*ref), node);
1332 /* No control with the given ID exists, so start
1333 searching for the next largest ID. We know there
1334 is one, otherwise the first 'if' above would have
1336 list_for_each_entry(ref, &hdl->ctrl_refs, node)
1337 if (id < ref->ctrl->id)
1341 mutex_unlock(&hdl->lock);
1346 memset(qc, 0, sizeof(*qc));
1348 strlcpy(qc->name, ctrl->name, sizeof(qc->name));
1349 qc->minimum = ctrl->minimum;
1350 qc->maximum = ctrl->maximum;
1351 qc->default_value = ctrl->default_value;
1352 if (qc->type == V4L2_CTRL_TYPE_MENU)
1355 qc->step = ctrl->step;
1356 qc->flags = ctrl->flags;
1357 qc->type = ctrl->type;
1360 EXPORT_SYMBOL(v4l2_queryctrl);
1362 int v4l2_subdev_queryctrl(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc)
1364 return v4l2_queryctrl(sd->ctrl_handler, qc);
1366 EXPORT_SYMBOL(v4l2_subdev_queryctrl);
1368 /* Implement VIDIOC_QUERYMENU */
1369 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm)
1371 struct v4l2_ctrl *ctrl;
1374 ctrl = v4l2_ctrl_find(hdl, qm->id);
1380 if (ctrl->qmenu == NULL ||
1381 i < ctrl->minimum || i > ctrl->maximum)
1383 /* Use mask to see if this menu item should be skipped */
1384 if (ctrl->menu_skip_mask & (1 << i))
1386 /* Empty menu items should also be skipped */
1387 if (ctrl->qmenu[i] == NULL || ctrl->qmenu[i][0] == '\0')
1389 strlcpy(qm->name, ctrl->qmenu[i], sizeof(qm->name));
1392 EXPORT_SYMBOL(v4l2_querymenu);
1394 int v4l2_subdev_querymenu(struct v4l2_subdev *sd, struct v4l2_querymenu *qm)
1396 return v4l2_querymenu(sd->ctrl_handler, qm);
1398 EXPORT_SYMBOL(v4l2_subdev_querymenu);
1402 /* Some general notes on the atomic requirements of VIDIOC_G/TRY/S_EXT_CTRLS:
1404 It is not a fully atomic operation, just best-effort only. After all, if
1405 multiple controls have to be set through multiple i2c writes (for example)
1406 then some initial writes may succeed while others fail. Thus leaving the
1407 system in an inconsistent state. The question is how much effort you are
1408 willing to spend on trying to make something atomic that really isn't.
1410 From the point of view of an application the main requirement is that
1411 when you call VIDIOC_S_EXT_CTRLS and some values are invalid then an
1412 error should be returned without actually affecting any controls.
1414 If all the values are correct, then it is acceptable to just give up
1415 in case of low-level errors.
1417 It is important though that the application can tell when only a partial
1418 configuration was done. The way we do that is through the error_idx field
1419 of struct v4l2_ext_controls: if that is equal to the count field then no
1420 controls were affected. Otherwise all controls before that index were
1421 successful in performing their 'get' or 'set' operation, the control at
1422 the given index failed, and you don't know what happened with the controls
1423 after the failed one. Since if they were part of a control cluster they
1424 could have been successfully processed (if a cluster member was encountered
1425 at index < error_idx), they could have failed (if a cluster member was at
1426 error_idx), or they may not have been processed yet (if the first cluster
1427 member appeared after error_idx).
1429 It is all fairly theoretical, though. In practice all you can do is to
1430 bail out. If error_idx == count, then it is an application bug. If
1431 error_idx < count then it is only an application bug if the error code was
1432 EBUSY. That usually means that something started streaming just when you
1433 tried to set the controls. In all other cases it is a driver/hardware
1434 problem and all you can do is to retry or bail out.
1436 Note that these rules do not apply to VIDIOC_TRY_EXT_CTRLS: since that
1437 never modifies controls the error_idx is just set to whatever control
1438 has an invalid value.
1441 /* Prepare for the extended g/s/try functions.
1442 Find the controls in the control array and do some basic checks. */
1443 static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
1444 struct v4l2_ext_controls *cs,
1445 struct ctrl_helper *helpers,
1450 for (i = 0; i < cs->count; i++) {
1451 struct v4l2_ext_control *c = &cs->controls[i];
1452 struct v4l2_ctrl *ctrl;
1453 u32 id = c->id & V4L2_CTRL_ID_MASK;
1458 if (cs->ctrl_class && V4L2_CTRL_ID2CLASS(id) != cs->ctrl_class)
1461 /* Old-style private controls are not allowed for
1462 extended controls */
1463 if (id >= V4L2_CID_PRIVATE_BASE)
1465 ctrl = v4l2_ctrl_find(hdl, id);
1468 if (ctrl->flags & V4L2_CTRL_FLAG_DISABLED)
1471 helpers[i].ctrl = ctrl;
1472 helpers[i].handled = false;
1477 typedef int (*cluster_func)(struct v4l2_ext_control *c,
1478 struct v4l2_ctrl *ctrl);
1480 /* Walk over all controls in v4l2_ext_controls belonging to the same cluster
1481 and call the provided function. */
1482 static int cluster_walk(unsigned from,
1483 struct v4l2_ext_controls *cs,
1484 struct ctrl_helper *helpers,
1487 struct v4l2_ctrl **cluster = helpers[from].ctrl->cluster;
1491 /* Find any controls from the same cluster and call the function */
1492 for (i = from; !ret && i < cs->count; i++) {
1493 struct v4l2_ctrl *ctrl = helpers[i].ctrl;
1495 if (!helpers[i].handled && ctrl->cluster == cluster)
1496 ret = f(&cs->controls[i], ctrl);
1501 static void cluster_done(unsigned from,
1502 struct v4l2_ext_controls *cs,
1503 struct ctrl_helper *helpers)
1505 struct v4l2_ctrl **cluster = helpers[from].ctrl->cluster;
1508 /* Find any controls from the same cluster and mark them as handled */
1509 for (i = from; i < cs->count; i++)
1510 if (helpers[i].ctrl->cluster == cluster)
1511 helpers[i].handled = true;
1514 /* Handles the corner case where cs->count == 0. It checks whether the
1515 specified control class exists. If that class ID is 0, then it checks
1516 whether there are any controls at all. */
1517 static int class_check(struct v4l2_ctrl_handler *hdl, u32 ctrl_class)
1519 if (ctrl_class == 0)
1520 return list_empty(&hdl->ctrl_refs) ? -EINVAL : 0;
1521 return find_ref_lock(hdl, ctrl_class | 1) ? 0 : -EINVAL;
1526 /* Get extended controls. Allocates the helpers array if needed. */
1527 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs)
1529 struct ctrl_helper helper[4];
1530 struct ctrl_helper *helpers = helper;
1534 cs->error_idx = cs->count;
1535 cs->ctrl_class = V4L2_CTRL_ID2CLASS(cs->ctrl_class);
1541 return class_check(hdl, cs->ctrl_class);
1543 if (cs->count > ARRAY_SIZE(helper)) {
1544 helpers = kmalloc(sizeof(helper[0]) * cs->count, GFP_KERNEL);
1545 if (helpers == NULL)
1549 ret = prepare_ext_ctrls(hdl, cs, helpers, false);
1551 for (i = 0; !ret && i < cs->count; i++)
1552 if (helpers[i].ctrl->flags & V4L2_CTRL_FLAG_WRITE_ONLY)
1555 for (i = 0; !ret && i < cs->count; i++) {
1556 struct v4l2_ctrl *ctrl = helpers[i].ctrl;
1557 struct v4l2_ctrl *master = ctrl->cluster[0];
1559 if (helpers[i].handled)
1564 v4l2_ctrl_lock(master);
1565 /* g_volatile_ctrl will update the current control values */
1566 if (ctrl->is_volatile && master->ops->g_volatile_ctrl)
1567 ret = master->ops->g_volatile_ctrl(master);
1568 /* If OK, then copy the current control values to the caller */
1570 ret = cluster_walk(i, cs, helpers, cur_to_user);
1571 v4l2_ctrl_unlock(master);
1572 cluster_done(i, cs, helpers);
1575 if (cs->count > ARRAY_SIZE(helper))
1579 EXPORT_SYMBOL(v4l2_g_ext_ctrls);
1581 int v4l2_subdev_g_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs)
1583 return v4l2_g_ext_ctrls(sd->ctrl_handler, cs);
1585 EXPORT_SYMBOL(v4l2_subdev_g_ext_ctrls);
1587 /* Helper function to get a single control */
1588 static int get_ctrl(struct v4l2_ctrl *ctrl, s32 *val)
1590 struct v4l2_ctrl *master = ctrl->cluster[0];
1593 if (ctrl->flags & V4L2_CTRL_FLAG_WRITE_ONLY)
1596 v4l2_ctrl_lock(master);
1597 /* g_volatile_ctrl will update the current control values */
1598 if (ctrl->is_volatile && master->ops->g_volatile_ctrl)
1599 ret = master->ops->g_volatile_ctrl(master);
1600 *val = ctrl->cur.val;
1601 v4l2_ctrl_unlock(master);
1605 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *control)
1607 struct v4l2_ctrl *ctrl = v4l2_ctrl_find(hdl, control->id);
1609 if (ctrl == NULL || !type_is_int(ctrl))
1611 return get_ctrl(ctrl, &control->value);
1613 EXPORT_SYMBOL(v4l2_g_ctrl);
1615 int v4l2_subdev_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *control)
1617 return v4l2_g_ctrl(sd->ctrl_handler, control);
1619 EXPORT_SYMBOL(v4l2_subdev_g_ctrl);
1621 s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl)
1625 /* It's a driver bug if this happens. */
1626 WARN_ON(!type_is_int(ctrl));
1627 get_ctrl(ctrl, &val);
1630 EXPORT_SYMBOL(v4l2_ctrl_g_ctrl);
1633 /* Core function that calls try/s_ctrl and ensures that the new value is
1634 copied to the current value on a set.
1635 Must be called with ctrl->handler->lock held. */
1636 static int try_or_set_control_cluster(struct v4l2_ctrl *master, bool set)
1642 /* Go through the cluster and either validate the new value or
1643 (if no new value was set), copy the current value to the new
1644 value, ensuring a consistent view for the control ops when
1646 for (i = 0; !ret && i < master->ncontrols; i++) {
1647 struct v4l2_ctrl *ctrl = master->cluster[i];
1653 /* Double check this: it may have changed since the
1654 last check in try_or_set_ext_ctrls(). */
1655 if (set && (ctrl->flags & V4L2_CTRL_FLAG_GRABBED))
1658 /* Validate if required */
1660 ret = validate_new(ctrl);
1663 /* No new value was set, so copy the current and force
1664 a call to try_ctrl later, since the values for the cluster
1665 may now have changed and the end result might be invalid. */
1670 /* For larger clusters you have to call try_ctrl again to
1671 verify that the controls are still valid after the
1672 'cur_to_new' above. */
1673 if (!ret && master->ops->try_ctrl && try)
1674 ret = master->ops->try_ctrl(master);
1676 /* Don't set if there is no change */
1677 if (!ret && set && cluster_changed(master)) {
1678 ret = master->ops->s_ctrl(master);
1679 /* If OK, then make the new values permanent. */
1681 for (i = 0; i < master->ncontrols; i++)
1682 new_to_cur(master->cluster[i]);
1687 /* Try or set controls. */
1688 static int try_or_set_ext_ctrls(struct v4l2_ctrl_handler *hdl,
1689 struct v4l2_ext_controls *cs,
1690 struct ctrl_helper *helpers,
1696 cs->error_idx = cs->count;
1697 for (i = 0; i < cs->count; i++) {
1698 struct v4l2_ctrl *ctrl = helpers[i].ctrl;
1703 if (ctrl->flags & V4L2_CTRL_FLAG_READ_ONLY)
1705 /* This test is also done in try_set_control_cluster() which
1706 is called in atomic context, so that has the final say,
1707 but it makes sense to do an up-front check as well. Once
1708 an error occurs in try_set_control_cluster() some other
1709 controls may have been set already and we want to do a
1710 best-effort to avoid that. */
1711 if (set && (ctrl->flags & V4L2_CTRL_FLAG_GRABBED))
1715 for (i = 0; !ret && i < cs->count; i++) {
1716 struct v4l2_ctrl *ctrl = helpers[i].ctrl;
1717 struct v4l2_ctrl *master = ctrl->cluster[0];
1721 if (helpers[i].handled)
1724 v4l2_ctrl_lock(ctrl);
1726 /* Reset the 'is_new' flags of the cluster */
1727 for (j = 0; j < master->ncontrols; j++)
1728 if (master->cluster[j])
1729 master->cluster[j]->is_new = 0;
1731 /* Copy the new caller-supplied control values.
1732 user_to_new() sets 'is_new' to 1. */
1733 ret = cluster_walk(i, cs, helpers, user_to_new);
1736 ret = try_or_set_control_cluster(master, set);
1738 /* Copy the new values back to userspace. */
1740 ret = cluster_walk(i, cs, helpers, new_to_user);
1742 v4l2_ctrl_unlock(ctrl);
1743 cluster_done(i, cs, helpers);
1748 /* Try or try-and-set controls */
1749 static int try_set_ext_ctrls(struct v4l2_ctrl_handler *hdl,
1750 struct v4l2_ext_controls *cs,
1753 struct ctrl_helper helper[4];
1754 struct ctrl_helper *helpers = helper;
1758 cs->error_idx = cs->count;
1759 cs->ctrl_class = V4L2_CTRL_ID2CLASS(cs->ctrl_class);
1765 return class_check(hdl, cs->ctrl_class);
1767 if (cs->count > ARRAY_SIZE(helper)) {
1768 helpers = kmalloc(sizeof(helper[0]) * cs->count, GFP_KERNEL);
1772 ret = prepare_ext_ctrls(hdl, cs, helpers, !set);
1776 /* First 'try' all controls and abort on error */
1777 ret = try_or_set_ext_ctrls(hdl, cs, helpers, false);
1778 /* If this is a 'set' operation and the initial 'try' failed,
1779 then set error_idx to count to tell the application that no
1780 controls changed value yet. */
1782 cs->error_idx = cs->count;
1784 /* Reset 'handled' state */
1785 for (i = 0; i < cs->count; i++)
1786 helpers[i].handled = false;
1787 ret = try_or_set_ext_ctrls(hdl, cs, helpers, true);
1791 if (cs->count > ARRAY_SIZE(helper))
1796 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs)
1798 return try_set_ext_ctrls(hdl, cs, false);
1800 EXPORT_SYMBOL(v4l2_try_ext_ctrls);
1802 int v4l2_s_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs)
1804 return try_set_ext_ctrls(hdl, cs, true);
1806 EXPORT_SYMBOL(v4l2_s_ext_ctrls);
1808 int v4l2_subdev_try_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs)
1810 return try_set_ext_ctrls(sd->ctrl_handler, cs, false);
1812 EXPORT_SYMBOL(v4l2_subdev_try_ext_ctrls);
1814 int v4l2_subdev_s_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs)
1816 return try_set_ext_ctrls(sd->ctrl_handler, cs, true);
1818 EXPORT_SYMBOL(v4l2_subdev_s_ext_ctrls);
1820 /* Helper function for VIDIOC_S_CTRL compatibility */
1821 static int set_ctrl(struct v4l2_ctrl *ctrl, s32 *val)
1823 struct v4l2_ctrl *master = ctrl->cluster[0];
1827 v4l2_ctrl_lock(ctrl);
1829 /* Reset the 'is_new' flags of the cluster */
1830 for (i = 0; i < master->ncontrols; i++)
1831 if (master->cluster[i])
1832 master->cluster[i]->is_new = 0;
1836 ret = try_or_set_control_cluster(master, false);
1838 ret = try_or_set_control_cluster(master, true);
1839 *val = ctrl->cur.val;
1840 v4l2_ctrl_unlock(ctrl);
1844 int v4l2_s_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *control)
1846 struct v4l2_ctrl *ctrl = v4l2_ctrl_find(hdl, control->id);
1848 if (ctrl == NULL || !type_is_int(ctrl))
1851 return set_ctrl(ctrl, &control->value);
1853 EXPORT_SYMBOL(v4l2_s_ctrl);
1855 int v4l2_subdev_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *control)
1857 return v4l2_s_ctrl(sd->ctrl_handler, control);
1859 EXPORT_SYMBOL(v4l2_subdev_s_ctrl);
1861 int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
1863 /* It's a driver bug if this happens. */
1864 WARN_ON(!type_is_int(ctrl));
1865 return set_ctrl(ctrl, &val);
1867 EXPORT_SYMBOL(v4l2_ctrl_s_ctrl);