xref: /openbmc/linux/drivers/media/usb/uvc/uvc_ctrl.c (revision ae0be8de)
1 /*
2  *      uvc_ctrl.c  --  USB Video Class driver - Controls
3  *
4  *      Copyright (C) 2005-2010
5  *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
6  *
7  *      This program is free software; you can redistribute it and/or modify
8  *      it under the terms of the GNU General Public License as published by
9  *      the Free Software Foundation; either version 2 of the License, or
10  *      (at your option) any later version.
11  *
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/list.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/uaccess.h>
19 #include <linux/usb.h>
20 #include <linux/videodev2.h>
21 #include <linux/vmalloc.h>
22 #include <linux/wait.h>
23 #include <linux/workqueue.h>
24 #include <linux/atomic.h>
25 #include <media/v4l2-ctrls.h>
26 
27 #include "uvcvideo.h"
28 
29 #define UVC_CTRL_DATA_CURRENT	0
30 #define UVC_CTRL_DATA_BACKUP	1
31 #define UVC_CTRL_DATA_MIN	2
32 #define UVC_CTRL_DATA_MAX	3
33 #define UVC_CTRL_DATA_RES	4
34 #define UVC_CTRL_DATA_DEF	5
35 #define UVC_CTRL_DATA_LAST	6
36 
37 /* ------------------------------------------------------------------------
38  * Controls
39  */
40 
41 static const struct uvc_control_info uvc_ctrls[] = {
42 	{
43 		.entity		= UVC_GUID_UVC_PROCESSING,
44 		.selector	= UVC_PU_BRIGHTNESS_CONTROL,
45 		.index		= 0,
46 		.size		= 2,
47 		.flags		= UVC_CTRL_FLAG_SET_CUR
48 				| UVC_CTRL_FLAG_GET_RANGE
49 				| UVC_CTRL_FLAG_RESTORE,
50 	},
51 	{
52 		.entity		= UVC_GUID_UVC_PROCESSING,
53 		.selector	= UVC_PU_CONTRAST_CONTROL,
54 		.index		= 1,
55 		.size		= 2,
56 		.flags		= UVC_CTRL_FLAG_SET_CUR
57 				| UVC_CTRL_FLAG_GET_RANGE
58 				| UVC_CTRL_FLAG_RESTORE,
59 	},
60 	{
61 		.entity		= UVC_GUID_UVC_PROCESSING,
62 		.selector	= UVC_PU_HUE_CONTROL,
63 		.index		= 2,
64 		.size		= 2,
65 		.flags		= UVC_CTRL_FLAG_SET_CUR
66 				| UVC_CTRL_FLAG_GET_RANGE
67 				| UVC_CTRL_FLAG_RESTORE
68 				| UVC_CTRL_FLAG_AUTO_UPDATE,
69 	},
70 	{
71 		.entity		= UVC_GUID_UVC_PROCESSING,
72 		.selector	= UVC_PU_SATURATION_CONTROL,
73 		.index		= 3,
74 		.size		= 2,
75 		.flags		= UVC_CTRL_FLAG_SET_CUR
76 				| UVC_CTRL_FLAG_GET_RANGE
77 				| UVC_CTRL_FLAG_RESTORE,
78 	},
79 	{
80 		.entity		= UVC_GUID_UVC_PROCESSING,
81 		.selector	= UVC_PU_SHARPNESS_CONTROL,
82 		.index		= 4,
83 		.size		= 2,
84 		.flags		= UVC_CTRL_FLAG_SET_CUR
85 				| UVC_CTRL_FLAG_GET_RANGE
86 				| UVC_CTRL_FLAG_RESTORE,
87 	},
88 	{
89 		.entity		= UVC_GUID_UVC_PROCESSING,
90 		.selector	= UVC_PU_GAMMA_CONTROL,
91 		.index		= 5,
92 		.size		= 2,
93 		.flags		= UVC_CTRL_FLAG_SET_CUR
94 				| UVC_CTRL_FLAG_GET_RANGE
95 				| UVC_CTRL_FLAG_RESTORE,
96 	},
97 	{
98 		.entity		= UVC_GUID_UVC_PROCESSING,
99 		.selector	= UVC_PU_WHITE_BALANCE_TEMPERATURE_CONTROL,
100 		.index		= 6,
101 		.size		= 2,
102 		.flags		= UVC_CTRL_FLAG_SET_CUR
103 				| UVC_CTRL_FLAG_GET_RANGE
104 				| UVC_CTRL_FLAG_RESTORE
105 				| UVC_CTRL_FLAG_AUTO_UPDATE,
106 	},
107 	{
108 		.entity		= UVC_GUID_UVC_PROCESSING,
109 		.selector	= UVC_PU_WHITE_BALANCE_COMPONENT_CONTROL,
110 		.index		= 7,
111 		.size		= 4,
112 		.flags		= UVC_CTRL_FLAG_SET_CUR
113 				| UVC_CTRL_FLAG_GET_RANGE
114 				| UVC_CTRL_FLAG_RESTORE
115 				| UVC_CTRL_FLAG_AUTO_UPDATE,
116 	},
117 	{
118 		.entity		= UVC_GUID_UVC_PROCESSING,
119 		.selector	= UVC_PU_BACKLIGHT_COMPENSATION_CONTROL,
120 		.index		= 8,
121 		.size		= 2,
122 		.flags		= UVC_CTRL_FLAG_SET_CUR
123 				| UVC_CTRL_FLAG_GET_RANGE
124 				| UVC_CTRL_FLAG_RESTORE,
125 	},
126 	{
127 		.entity		= UVC_GUID_UVC_PROCESSING,
128 		.selector	= UVC_PU_GAIN_CONTROL,
129 		.index		= 9,
130 		.size		= 2,
131 		.flags		= UVC_CTRL_FLAG_SET_CUR
132 				| UVC_CTRL_FLAG_GET_RANGE
133 				| UVC_CTRL_FLAG_RESTORE,
134 	},
135 	{
136 		.entity		= UVC_GUID_UVC_PROCESSING,
137 		.selector	= UVC_PU_POWER_LINE_FREQUENCY_CONTROL,
138 		.index		= 10,
139 		.size		= 1,
140 		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
141 				| UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_RESTORE,
142 	},
143 	{
144 		.entity		= UVC_GUID_UVC_PROCESSING,
145 		.selector	= UVC_PU_HUE_AUTO_CONTROL,
146 		.index		= 11,
147 		.size		= 1,
148 		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
149 				| UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_RESTORE,
150 	},
151 	{
152 		.entity		= UVC_GUID_UVC_PROCESSING,
153 		.selector	= UVC_PU_WHITE_BALANCE_TEMPERATURE_AUTO_CONTROL,
154 		.index		= 12,
155 		.size		= 1,
156 		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
157 				| UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_RESTORE,
158 	},
159 	{
160 		.entity		= UVC_GUID_UVC_PROCESSING,
161 		.selector	= UVC_PU_WHITE_BALANCE_COMPONENT_AUTO_CONTROL,
162 		.index		= 13,
163 		.size		= 1,
164 		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
165 				| UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_RESTORE,
166 	},
167 	{
168 		.entity		= UVC_GUID_UVC_PROCESSING,
169 		.selector	= UVC_PU_DIGITAL_MULTIPLIER_CONTROL,
170 		.index		= 14,
171 		.size		= 2,
172 		.flags		= UVC_CTRL_FLAG_SET_CUR
173 				| UVC_CTRL_FLAG_GET_RANGE
174 				| UVC_CTRL_FLAG_RESTORE,
175 	},
176 	{
177 		.entity		= UVC_GUID_UVC_PROCESSING,
178 		.selector	= UVC_PU_DIGITAL_MULTIPLIER_LIMIT_CONTROL,
179 		.index		= 15,
180 		.size		= 2,
181 		.flags		= UVC_CTRL_FLAG_SET_CUR
182 				| UVC_CTRL_FLAG_GET_RANGE
183 				| UVC_CTRL_FLAG_RESTORE,
184 	},
185 	{
186 		.entity		= UVC_GUID_UVC_PROCESSING,
187 		.selector	= UVC_PU_ANALOG_VIDEO_STANDARD_CONTROL,
188 		.index		= 16,
189 		.size		= 1,
190 		.flags		= UVC_CTRL_FLAG_GET_CUR,
191 	},
192 	{
193 		.entity		= UVC_GUID_UVC_PROCESSING,
194 		.selector	= UVC_PU_ANALOG_LOCK_STATUS_CONTROL,
195 		.index		= 17,
196 		.size		= 1,
197 		.flags		= UVC_CTRL_FLAG_GET_CUR,
198 	},
199 	{
200 		.entity		= UVC_GUID_UVC_CAMERA,
201 		.selector	= UVC_CT_SCANNING_MODE_CONTROL,
202 		.index		= 0,
203 		.size		= 1,
204 		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
205 				| UVC_CTRL_FLAG_RESTORE,
206 	},
207 	{
208 		.entity		= UVC_GUID_UVC_CAMERA,
209 		.selector	= UVC_CT_AE_MODE_CONTROL,
210 		.index		= 1,
211 		.size		= 1,
212 		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
213 				| UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_GET_RES
214 				| UVC_CTRL_FLAG_RESTORE,
215 	},
216 	{
217 		.entity		= UVC_GUID_UVC_CAMERA,
218 		.selector	= UVC_CT_AE_PRIORITY_CONTROL,
219 		.index		= 2,
220 		.size		= 1,
221 		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
222 				| UVC_CTRL_FLAG_RESTORE,
223 	},
224 	{
225 		.entity		= UVC_GUID_UVC_CAMERA,
226 		.selector	= UVC_CT_EXPOSURE_TIME_ABSOLUTE_CONTROL,
227 		.index		= 3,
228 		.size		= 4,
229 		.flags		= UVC_CTRL_FLAG_SET_CUR
230 				| UVC_CTRL_FLAG_GET_RANGE
231 				| UVC_CTRL_FLAG_RESTORE
232 				| UVC_CTRL_FLAG_AUTO_UPDATE,
233 	},
234 	{
235 		.entity		= UVC_GUID_UVC_CAMERA,
236 		.selector	= UVC_CT_EXPOSURE_TIME_RELATIVE_CONTROL,
237 		.index		= 4,
238 		.size		= 1,
239 		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_RESTORE,
240 	},
241 	{
242 		.entity		= UVC_GUID_UVC_CAMERA,
243 		.selector	= UVC_CT_FOCUS_ABSOLUTE_CONTROL,
244 		.index		= 5,
245 		.size		= 2,
246 		.flags		= UVC_CTRL_FLAG_SET_CUR
247 				| UVC_CTRL_FLAG_GET_RANGE
248 				| UVC_CTRL_FLAG_RESTORE
249 				| UVC_CTRL_FLAG_AUTO_UPDATE,
250 	},
251 	{
252 		.entity		= UVC_GUID_UVC_CAMERA,
253 		.selector	= UVC_CT_FOCUS_RELATIVE_CONTROL,
254 		.index		= 6,
255 		.size		= 2,
256 		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_MIN
257 				| UVC_CTRL_FLAG_GET_MAX | UVC_CTRL_FLAG_GET_RES
258 				| UVC_CTRL_FLAG_GET_DEF
259 				| UVC_CTRL_FLAG_AUTO_UPDATE,
260 	},
261 	{
262 		.entity		= UVC_GUID_UVC_CAMERA,
263 		.selector	= UVC_CT_IRIS_ABSOLUTE_CONTROL,
264 		.index		= 7,
265 		.size		= 2,
266 		.flags		= UVC_CTRL_FLAG_SET_CUR
267 				| UVC_CTRL_FLAG_GET_RANGE
268 				| UVC_CTRL_FLAG_RESTORE
269 				| UVC_CTRL_FLAG_AUTO_UPDATE,
270 	},
271 	{
272 		.entity		= UVC_GUID_UVC_CAMERA,
273 		.selector	= UVC_CT_IRIS_RELATIVE_CONTROL,
274 		.index		= 8,
275 		.size		= 1,
276 		.flags		= UVC_CTRL_FLAG_SET_CUR
277 				| UVC_CTRL_FLAG_AUTO_UPDATE,
278 	},
279 	{
280 		.entity		= UVC_GUID_UVC_CAMERA,
281 		.selector	= UVC_CT_ZOOM_ABSOLUTE_CONTROL,
282 		.index		= 9,
283 		.size		= 2,
284 		.flags		= UVC_CTRL_FLAG_SET_CUR
285 				| UVC_CTRL_FLAG_GET_RANGE
286 				| UVC_CTRL_FLAG_RESTORE
287 				| UVC_CTRL_FLAG_AUTO_UPDATE,
288 	},
289 	{
290 		.entity		= UVC_GUID_UVC_CAMERA,
291 		.selector	= UVC_CT_ZOOM_RELATIVE_CONTROL,
292 		.index		= 10,
293 		.size		= 3,
294 		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_MIN
295 				| UVC_CTRL_FLAG_GET_MAX | UVC_CTRL_FLAG_GET_RES
296 				| UVC_CTRL_FLAG_GET_DEF
297 				| UVC_CTRL_FLAG_AUTO_UPDATE,
298 	},
299 	{
300 		.entity		= UVC_GUID_UVC_CAMERA,
301 		.selector	= UVC_CT_PANTILT_ABSOLUTE_CONTROL,
302 		.index		= 11,
303 		.size		= 8,
304 		.flags		= UVC_CTRL_FLAG_SET_CUR
305 				| UVC_CTRL_FLAG_GET_RANGE
306 				| UVC_CTRL_FLAG_RESTORE
307 				| UVC_CTRL_FLAG_AUTO_UPDATE,
308 	},
309 	{
310 		.entity		= UVC_GUID_UVC_CAMERA,
311 		.selector	= UVC_CT_PANTILT_RELATIVE_CONTROL,
312 		.index		= 12,
313 		.size		= 4,
314 		.flags		= UVC_CTRL_FLAG_SET_CUR
315 				| UVC_CTRL_FLAG_GET_RANGE
316 				| UVC_CTRL_FLAG_AUTO_UPDATE,
317 	},
318 	{
319 		.entity		= UVC_GUID_UVC_CAMERA,
320 		.selector	= UVC_CT_ROLL_ABSOLUTE_CONTROL,
321 		.index		= 13,
322 		.size		= 2,
323 		.flags		= UVC_CTRL_FLAG_SET_CUR
324 				| UVC_CTRL_FLAG_GET_RANGE
325 				| UVC_CTRL_FLAG_RESTORE
326 				| UVC_CTRL_FLAG_AUTO_UPDATE,
327 	},
328 	{
329 		.entity		= UVC_GUID_UVC_CAMERA,
330 		.selector	= UVC_CT_ROLL_RELATIVE_CONTROL,
331 		.index		= 14,
332 		.size		= 2,
333 		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_MIN
334 				| UVC_CTRL_FLAG_GET_MAX | UVC_CTRL_FLAG_GET_RES
335 				| UVC_CTRL_FLAG_GET_DEF
336 				| UVC_CTRL_FLAG_AUTO_UPDATE,
337 	},
338 	{
339 		.entity		= UVC_GUID_UVC_CAMERA,
340 		.selector	= UVC_CT_FOCUS_AUTO_CONTROL,
341 		.index		= 17,
342 		.size		= 1,
343 		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
344 				| UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_RESTORE,
345 	},
346 	{
347 		.entity		= UVC_GUID_UVC_CAMERA,
348 		.selector	= UVC_CT_PRIVACY_CONTROL,
349 		.index		= 18,
350 		.size		= 1,
351 		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
352 				| UVC_CTRL_FLAG_RESTORE
353 				| UVC_CTRL_FLAG_AUTO_UPDATE,
354 	},
355 };
356 
357 static const struct uvc_menu_info power_line_frequency_controls[] = {
358 	{ 0, "Disabled" },
359 	{ 1, "50 Hz" },
360 	{ 2, "60 Hz" },
361 };
362 
363 static const struct uvc_menu_info exposure_auto_controls[] = {
364 	{ 2, "Auto Mode" },
365 	{ 1, "Manual Mode" },
366 	{ 4, "Shutter Priority Mode" },
367 	{ 8, "Aperture Priority Mode" },
368 };
369 
370 static s32 uvc_ctrl_get_zoom(struct uvc_control_mapping *mapping,
371 	u8 query, const u8 *data)
372 {
373 	s8 zoom = (s8)data[0];
374 
375 	switch (query) {
376 	case UVC_GET_CUR:
377 		return (zoom == 0) ? 0 : (zoom > 0 ? data[2] : -data[2]);
378 
379 	case UVC_GET_MIN:
380 	case UVC_GET_MAX:
381 	case UVC_GET_RES:
382 	case UVC_GET_DEF:
383 	default:
384 		return data[2];
385 	}
386 }
387 
388 static void uvc_ctrl_set_zoom(struct uvc_control_mapping *mapping,
389 	s32 value, u8 *data)
390 {
391 	data[0] = value == 0 ? 0 : (value > 0) ? 1 : 0xff;
392 	data[2] = min((int)abs(value), 0xff);
393 }
394 
395 static s32 uvc_ctrl_get_rel_speed(struct uvc_control_mapping *mapping,
396 	u8 query, const u8 *data)
397 {
398 	unsigned int first = mapping->offset / 8;
399 	s8 rel = (s8)data[first];
400 
401 	switch (query) {
402 	case UVC_GET_CUR:
403 		return (rel == 0) ? 0 : (rel > 0 ? data[first+1]
404 						 : -data[first+1]);
405 	case UVC_GET_MIN:
406 		return -data[first+1];
407 	case UVC_GET_MAX:
408 	case UVC_GET_RES:
409 	case UVC_GET_DEF:
410 	default:
411 		return data[first+1];
412 	}
413 }
414 
415 static void uvc_ctrl_set_rel_speed(struct uvc_control_mapping *mapping,
416 	s32 value, u8 *data)
417 {
418 	unsigned int first = mapping->offset / 8;
419 
420 	data[first] = value == 0 ? 0 : (value > 0) ? 1 : 0xff;
421 	data[first+1] = min_t(int, abs(value), 0xff);
422 }
423 
424 static const struct uvc_control_mapping uvc_ctrl_mappings[] = {
425 	{
426 		.id		= V4L2_CID_BRIGHTNESS,
427 		.name		= "Brightness",
428 		.entity		= UVC_GUID_UVC_PROCESSING,
429 		.selector	= UVC_PU_BRIGHTNESS_CONTROL,
430 		.size		= 16,
431 		.offset		= 0,
432 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
433 		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
434 	},
435 	{
436 		.id		= V4L2_CID_CONTRAST,
437 		.name		= "Contrast",
438 		.entity		= UVC_GUID_UVC_PROCESSING,
439 		.selector	= UVC_PU_CONTRAST_CONTROL,
440 		.size		= 16,
441 		.offset		= 0,
442 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
443 		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
444 	},
445 	{
446 		.id		= V4L2_CID_HUE,
447 		.name		= "Hue",
448 		.entity		= UVC_GUID_UVC_PROCESSING,
449 		.selector	= UVC_PU_HUE_CONTROL,
450 		.size		= 16,
451 		.offset		= 0,
452 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
453 		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
454 		.master_id	= V4L2_CID_HUE_AUTO,
455 		.master_manual	= 0,
456 	},
457 	{
458 		.id		= V4L2_CID_SATURATION,
459 		.name		= "Saturation",
460 		.entity		= UVC_GUID_UVC_PROCESSING,
461 		.selector	= UVC_PU_SATURATION_CONTROL,
462 		.size		= 16,
463 		.offset		= 0,
464 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
465 		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
466 	},
467 	{
468 		.id		= V4L2_CID_SHARPNESS,
469 		.name		= "Sharpness",
470 		.entity		= UVC_GUID_UVC_PROCESSING,
471 		.selector	= UVC_PU_SHARPNESS_CONTROL,
472 		.size		= 16,
473 		.offset		= 0,
474 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
475 		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
476 	},
477 	{
478 		.id		= V4L2_CID_GAMMA,
479 		.name		= "Gamma",
480 		.entity		= UVC_GUID_UVC_PROCESSING,
481 		.selector	= UVC_PU_GAMMA_CONTROL,
482 		.size		= 16,
483 		.offset		= 0,
484 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
485 		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
486 	},
487 	{
488 		.id		= V4L2_CID_BACKLIGHT_COMPENSATION,
489 		.name		= "Backlight Compensation",
490 		.entity		= UVC_GUID_UVC_PROCESSING,
491 		.selector	= UVC_PU_BACKLIGHT_COMPENSATION_CONTROL,
492 		.size		= 16,
493 		.offset		= 0,
494 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
495 		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
496 	},
497 	{
498 		.id		= V4L2_CID_GAIN,
499 		.name		= "Gain",
500 		.entity		= UVC_GUID_UVC_PROCESSING,
501 		.selector	= UVC_PU_GAIN_CONTROL,
502 		.size		= 16,
503 		.offset		= 0,
504 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
505 		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
506 	},
507 	{
508 		.id		= V4L2_CID_POWER_LINE_FREQUENCY,
509 		.name		= "Power Line Frequency",
510 		.entity		= UVC_GUID_UVC_PROCESSING,
511 		.selector	= UVC_PU_POWER_LINE_FREQUENCY_CONTROL,
512 		.size		= 2,
513 		.offset		= 0,
514 		.v4l2_type	= V4L2_CTRL_TYPE_MENU,
515 		.data_type	= UVC_CTRL_DATA_TYPE_ENUM,
516 		.menu_info	= power_line_frequency_controls,
517 		.menu_count	= ARRAY_SIZE(power_line_frequency_controls),
518 	},
519 	{
520 		.id		= V4L2_CID_HUE_AUTO,
521 		.name		= "Hue, Auto",
522 		.entity		= UVC_GUID_UVC_PROCESSING,
523 		.selector	= UVC_PU_HUE_AUTO_CONTROL,
524 		.size		= 1,
525 		.offset		= 0,
526 		.v4l2_type	= V4L2_CTRL_TYPE_BOOLEAN,
527 		.data_type	= UVC_CTRL_DATA_TYPE_BOOLEAN,
528 		.slave_ids	= { V4L2_CID_HUE, },
529 	},
530 	{
531 		.id		= V4L2_CID_EXPOSURE_AUTO,
532 		.name		= "Exposure, Auto",
533 		.entity		= UVC_GUID_UVC_CAMERA,
534 		.selector	= UVC_CT_AE_MODE_CONTROL,
535 		.size		= 4,
536 		.offset		= 0,
537 		.v4l2_type	= V4L2_CTRL_TYPE_MENU,
538 		.data_type	= UVC_CTRL_DATA_TYPE_BITMASK,
539 		.menu_info	= exposure_auto_controls,
540 		.menu_count	= ARRAY_SIZE(exposure_auto_controls),
541 		.slave_ids	= { V4L2_CID_EXPOSURE_ABSOLUTE, },
542 	},
543 	{
544 		.id		= V4L2_CID_EXPOSURE_AUTO_PRIORITY,
545 		.name		= "Exposure, Auto Priority",
546 		.entity		= UVC_GUID_UVC_CAMERA,
547 		.selector	= UVC_CT_AE_PRIORITY_CONTROL,
548 		.size		= 1,
549 		.offset		= 0,
550 		.v4l2_type	= V4L2_CTRL_TYPE_BOOLEAN,
551 		.data_type	= UVC_CTRL_DATA_TYPE_BOOLEAN,
552 	},
553 	{
554 		.id		= V4L2_CID_EXPOSURE_ABSOLUTE,
555 		.name		= "Exposure (Absolute)",
556 		.entity		= UVC_GUID_UVC_CAMERA,
557 		.selector	= UVC_CT_EXPOSURE_TIME_ABSOLUTE_CONTROL,
558 		.size		= 32,
559 		.offset		= 0,
560 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
561 		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
562 		.master_id	= V4L2_CID_EXPOSURE_AUTO,
563 		.master_manual	= V4L2_EXPOSURE_MANUAL,
564 	},
565 	{
566 		.id		= V4L2_CID_AUTO_WHITE_BALANCE,
567 		.name		= "White Balance Temperature, Auto",
568 		.entity		= UVC_GUID_UVC_PROCESSING,
569 		.selector	= UVC_PU_WHITE_BALANCE_TEMPERATURE_AUTO_CONTROL,
570 		.size		= 1,
571 		.offset		= 0,
572 		.v4l2_type	= V4L2_CTRL_TYPE_BOOLEAN,
573 		.data_type	= UVC_CTRL_DATA_TYPE_BOOLEAN,
574 		.slave_ids	= { V4L2_CID_WHITE_BALANCE_TEMPERATURE, },
575 	},
576 	{
577 		.id		= V4L2_CID_WHITE_BALANCE_TEMPERATURE,
578 		.name		= "White Balance Temperature",
579 		.entity		= UVC_GUID_UVC_PROCESSING,
580 		.selector	= UVC_PU_WHITE_BALANCE_TEMPERATURE_CONTROL,
581 		.size		= 16,
582 		.offset		= 0,
583 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
584 		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
585 		.master_id	= V4L2_CID_AUTO_WHITE_BALANCE,
586 		.master_manual	= 0,
587 	},
588 	{
589 		.id		= V4L2_CID_AUTO_WHITE_BALANCE,
590 		.name		= "White Balance Component, Auto",
591 		.entity		= UVC_GUID_UVC_PROCESSING,
592 		.selector	= UVC_PU_WHITE_BALANCE_COMPONENT_AUTO_CONTROL,
593 		.size		= 1,
594 		.offset		= 0,
595 		.v4l2_type	= V4L2_CTRL_TYPE_BOOLEAN,
596 		.data_type	= UVC_CTRL_DATA_TYPE_BOOLEAN,
597 		.slave_ids	= { V4L2_CID_BLUE_BALANCE,
598 				    V4L2_CID_RED_BALANCE },
599 	},
600 	{
601 		.id		= V4L2_CID_BLUE_BALANCE,
602 		.name		= "White Balance Blue Component",
603 		.entity		= UVC_GUID_UVC_PROCESSING,
604 		.selector	= UVC_PU_WHITE_BALANCE_COMPONENT_CONTROL,
605 		.size		= 16,
606 		.offset		= 0,
607 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
608 		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
609 		.master_id	= V4L2_CID_AUTO_WHITE_BALANCE,
610 		.master_manual	= 0,
611 	},
612 	{
613 		.id		= V4L2_CID_RED_BALANCE,
614 		.name		= "White Balance Red Component",
615 		.entity		= UVC_GUID_UVC_PROCESSING,
616 		.selector	= UVC_PU_WHITE_BALANCE_COMPONENT_CONTROL,
617 		.size		= 16,
618 		.offset		= 16,
619 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
620 		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
621 		.master_id	= V4L2_CID_AUTO_WHITE_BALANCE,
622 		.master_manual	= 0,
623 	},
624 	{
625 		.id		= V4L2_CID_FOCUS_ABSOLUTE,
626 		.name		= "Focus (absolute)",
627 		.entity		= UVC_GUID_UVC_CAMERA,
628 		.selector	= UVC_CT_FOCUS_ABSOLUTE_CONTROL,
629 		.size		= 16,
630 		.offset		= 0,
631 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
632 		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
633 		.master_id	= V4L2_CID_FOCUS_AUTO,
634 		.master_manual	= 0,
635 	},
636 	{
637 		.id		= V4L2_CID_FOCUS_AUTO,
638 		.name		= "Focus, Auto",
639 		.entity		= UVC_GUID_UVC_CAMERA,
640 		.selector	= UVC_CT_FOCUS_AUTO_CONTROL,
641 		.size		= 1,
642 		.offset		= 0,
643 		.v4l2_type	= V4L2_CTRL_TYPE_BOOLEAN,
644 		.data_type	= UVC_CTRL_DATA_TYPE_BOOLEAN,
645 		.slave_ids	= { V4L2_CID_FOCUS_ABSOLUTE, },
646 	},
647 	{
648 		.id		= V4L2_CID_IRIS_ABSOLUTE,
649 		.name		= "Iris, Absolute",
650 		.entity		= UVC_GUID_UVC_CAMERA,
651 		.selector	= UVC_CT_IRIS_ABSOLUTE_CONTROL,
652 		.size		= 16,
653 		.offset		= 0,
654 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
655 		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
656 	},
657 	{
658 		.id		= V4L2_CID_IRIS_RELATIVE,
659 		.name		= "Iris, Relative",
660 		.entity		= UVC_GUID_UVC_CAMERA,
661 		.selector	= UVC_CT_IRIS_RELATIVE_CONTROL,
662 		.size		= 8,
663 		.offset		= 0,
664 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
665 		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
666 	},
667 	{
668 		.id		= V4L2_CID_ZOOM_ABSOLUTE,
669 		.name		= "Zoom, Absolute",
670 		.entity		= UVC_GUID_UVC_CAMERA,
671 		.selector	= UVC_CT_ZOOM_ABSOLUTE_CONTROL,
672 		.size		= 16,
673 		.offset		= 0,
674 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
675 		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
676 	},
677 	{
678 		.id		= V4L2_CID_ZOOM_CONTINUOUS,
679 		.name		= "Zoom, Continuous",
680 		.entity		= UVC_GUID_UVC_CAMERA,
681 		.selector	= UVC_CT_ZOOM_RELATIVE_CONTROL,
682 		.size		= 0,
683 		.offset		= 0,
684 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
685 		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
686 		.get		= uvc_ctrl_get_zoom,
687 		.set		= uvc_ctrl_set_zoom,
688 	},
689 	{
690 		.id		= V4L2_CID_PAN_ABSOLUTE,
691 		.name		= "Pan (Absolute)",
692 		.entity		= UVC_GUID_UVC_CAMERA,
693 		.selector	= UVC_CT_PANTILT_ABSOLUTE_CONTROL,
694 		.size		= 32,
695 		.offset		= 0,
696 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
697 		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
698 	},
699 	{
700 		.id		= V4L2_CID_TILT_ABSOLUTE,
701 		.name		= "Tilt (Absolute)",
702 		.entity		= UVC_GUID_UVC_CAMERA,
703 		.selector	= UVC_CT_PANTILT_ABSOLUTE_CONTROL,
704 		.size		= 32,
705 		.offset		= 32,
706 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
707 		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
708 	},
709 	{
710 		.id		= V4L2_CID_PAN_SPEED,
711 		.name		= "Pan (Speed)",
712 		.entity		= UVC_GUID_UVC_CAMERA,
713 		.selector	= UVC_CT_PANTILT_RELATIVE_CONTROL,
714 		.size		= 16,
715 		.offset		= 0,
716 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
717 		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
718 		.get		= uvc_ctrl_get_rel_speed,
719 		.set		= uvc_ctrl_set_rel_speed,
720 	},
721 	{
722 		.id		= V4L2_CID_TILT_SPEED,
723 		.name		= "Tilt (Speed)",
724 		.entity		= UVC_GUID_UVC_CAMERA,
725 		.selector	= UVC_CT_PANTILT_RELATIVE_CONTROL,
726 		.size		= 16,
727 		.offset		= 16,
728 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
729 		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
730 		.get		= uvc_ctrl_get_rel_speed,
731 		.set		= uvc_ctrl_set_rel_speed,
732 	},
733 	{
734 		.id		= V4L2_CID_PRIVACY,
735 		.name		= "Privacy",
736 		.entity		= UVC_GUID_UVC_CAMERA,
737 		.selector	= UVC_CT_PRIVACY_CONTROL,
738 		.size		= 1,
739 		.offset		= 0,
740 		.v4l2_type	= V4L2_CTRL_TYPE_BOOLEAN,
741 		.data_type	= UVC_CTRL_DATA_TYPE_BOOLEAN,
742 	},
743 };
744 
745 /* ------------------------------------------------------------------------
746  * Utility functions
747  */
748 
749 static inline u8 *uvc_ctrl_data(struct uvc_control *ctrl, int id)
750 {
751 	return ctrl->uvc_data + id * ctrl->info.size;
752 }
753 
754 static inline int uvc_test_bit(const u8 *data, int bit)
755 {
756 	return (data[bit >> 3] >> (bit & 7)) & 1;
757 }
758 
759 static inline void uvc_clear_bit(u8 *data, int bit)
760 {
761 	data[bit >> 3] &= ~(1 << (bit & 7));
762 }
763 
764 /* Extract the bit string specified by mapping->offset and mapping->size
765  * from the little-endian data stored at 'data' and return the result as
766  * a signed 32bit integer. Sign extension will be performed if the mapping
767  * references a signed data type.
768  */
769 static s32 uvc_get_le_value(struct uvc_control_mapping *mapping,
770 	u8 query, const u8 *data)
771 {
772 	int bits = mapping->size;
773 	int offset = mapping->offset;
774 	s32 value = 0;
775 	u8 mask;
776 
777 	data += offset / 8;
778 	offset &= 7;
779 	mask = ((1LL << bits) - 1) << offset;
780 
781 	for (; bits > 0; data++) {
782 		u8 byte = *data & mask;
783 		value |= offset > 0 ? (byte >> offset) : (byte << (-offset));
784 		bits -= 8 - (offset > 0 ? offset : 0);
785 		offset -= 8;
786 		mask = (1 << bits) - 1;
787 	}
788 
789 	/* Sign-extend the value if needed. */
790 	if (mapping->data_type == UVC_CTRL_DATA_TYPE_SIGNED)
791 		value |= -(value & (1 << (mapping->size - 1)));
792 
793 	return value;
794 }
795 
796 /* Set the bit string specified by mapping->offset and mapping->size
797  * in the little-endian data stored at 'data' to the value 'value'.
798  */
799 static void uvc_set_le_value(struct uvc_control_mapping *mapping,
800 	s32 value, u8 *data)
801 {
802 	int bits = mapping->size;
803 	int offset = mapping->offset;
804 	u8 mask;
805 
806 	/* According to the v4l2 spec, writing any value to a button control
807 	 * should result in the action belonging to the button control being
808 	 * triggered. UVC devices however want to see a 1 written -> override
809 	 * value.
810 	 */
811 	if (mapping->v4l2_type == V4L2_CTRL_TYPE_BUTTON)
812 		value = -1;
813 
814 	data += offset / 8;
815 	offset &= 7;
816 
817 	for (; bits > 0; data++) {
818 		mask = ((1LL << bits) - 1) << offset;
819 		*data = (*data & ~mask) | ((value << offset) & mask);
820 		value >>= offset ? offset : 8;
821 		bits -= 8 - offset;
822 		offset = 0;
823 	}
824 }
825 
826 /* ------------------------------------------------------------------------
827  * Terminal and unit management
828  */
829 
830 static const u8 uvc_processing_guid[16] = UVC_GUID_UVC_PROCESSING;
831 static const u8 uvc_camera_guid[16] = UVC_GUID_UVC_CAMERA;
832 static const u8 uvc_media_transport_input_guid[16] =
833 	UVC_GUID_UVC_MEDIA_TRANSPORT_INPUT;
834 
835 static int uvc_entity_match_guid(const struct uvc_entity *entity,
836 	const u8 guid[16])
837 {
838 	switch (UVC_ENTITY_TYPE(entity)) {
839 	case UVC_ITT_CAMERA:
840 		return memcmp(uvc_camera_guid, guid, 16) == 0;
841 
842 	case UVC_ITT_MEDIA_TRANSPORT_INPUT:
843 		return memcmp(uvc_media_transport_input_guid, guid, 16) == 0;
844 
845 	case UVC_VC_PROCESSING_UNIT:
846 		return memcmp(uvc_processing_guid, guid, 16) == 0;
847 
848 	case UVC_VC_EXTENSION_UNIT:
849 		return memcmp(entity->extension.guidExtensionCode,
850 			      guid, 16) == 0;
851 
852 	default:
853 		return 0;
854 	}
855 }
856 
857 /* ------------------------------------------------------------------------
858  * UVC Controls
859  */
860 
861 static void __uvc_find_control(struct uvc_entity *entity, u32 v4l2_id,
862 	struct uvc_control_mapping **mapping, struct uvc_control **control,
863 	int next)
864 {
865 	struct uvc_control *ctrl;
866 	struct uvc_control_mapping *map;
867 	unsigned int i;
868 
869 	if (entity == NULL)
870 		return;
871 
872 	for (i = 0; i < entity->ncontrols; ++i) {
873 		ctrl = &entity->controls[i];
874 		if (!ctrl->initialized)
875 			continue;
876 
877 		list_for_each_entry(map, &ctrl->info.mappings, list) {
878 			if ((map->id == v4l2_id) && !next) {
879 				*control = ctrl;
880 				*mapping = map;
881 				return;
882 			}
883 
884 			if ((*mapping == NULL || (*mapping)->id > map->id) &&
885 			    (map->id > v4l2_id) && next) {
886 				*control = ctrl;
887 				*mapping = map;
888 			}
889 		}
890 	}
891 }
892 
893 static struct uvc_control *uvc_find_control(struct uvc_video_chain *chain,
894 	u32 v4l2_id, struct uvc_control_mapping **mapping)
895 {
896 	struct uvc_control *ctrl = NULL;
897 	struct uvc_entity *entity;
898 	int next = v4l2_id & V4L2_CTRL_FLAG_NEXT_CTRL;
899 
900 	*mapping = NULL;
901 
902 	/* Mask the query flags. */
903 	v4l2_id &= V4L2_CTRL_ID_MASK;
904 
905 	/* Find the control. */
906 	list_for_each_entry(entity, &chain->entities, chain) {
907 		__uvc_find_control(entity, v4l2_id, mapping, &ctrl, next);
908 		if (ctrl && !next)
909 			return ctrl;
910 	}
911 
912 	if (ctrl == NULL && !next)
913 		uvc_trace(UVC_TRACE_CONTROL, "Control 0x%08x not found.\n",
914 				v4l2_id);
915 
916 	return ctrl;
917 }
918 
919 static int uvc_ctrl_populate_cache(struct uvc_video_chain *chain,
920 	struct uvc_control *ctrl)
921 {
922 	int ret;
923 
924 	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_DEF) {
925 		ret = uvc_query_ctrl(chain->dev, UVC_GET_DEF, ctrl->entity->id,
926 				     chain->dev->intfnum, ctrl->info.selector,
927 				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_DEF),
928 				     ctrl->info.size);
929 		if (ret < 0)
930 			return ret;
931 	}
932 
933 	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MIN) {
934 		ret = uvc_query_ctrl(chain->dev, UVC_GET_MIN, ctrl->entity->id,
935 				     chain->dev->intfnum, ctrl->info.selector,
936 				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN),
937 				     ctrl->info.size);
938 		if (ret < 0)
939 			return ret;
940 	}
941 	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MAX) {
942 		ret = uvc_query_ctrl(chain->dev, UVC_GET_MAX, ctrl->entity->id,
943 				     chain->dev->intfnum, ctrl->info.selector,
944 				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX),
945 				     ctrl->info.size);
946 		if (ret < 0)
947 			return ret;
948 	}
949 	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_RES) {
950 		ret = uvc_query_ctrl(chain->dev, UVC_GET_RES, ctrl->entity->id,
951 				     chain->dev->intfnum, ctrl->info.selector,
952 				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES),
953 				     ctrl->info.size);
954 		if (ret < 0) {
955 			if (UVC_ENTITY_TYPE(ctrl->entity) !=
956 			    UVC_VC_EXTENSION_UNIT)
957 				return ret;
958 
959 			/* GET_RES is mandatory for XU controls, but some
960 			 * cameras still choke on it. Ignore errors and set the
961 			 * resolution value to zero.
962 			 */
963 			uvc_warn_once(chain->dev, UVC_WARN_XU_GET_RES,
964 				      "UVC non compliance - GET_RES failed on "
965 				      "an XU control. Enabling workaround.\n");
966 			memset(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES), 0,
967 			       ctrl->info.size);
968 		}
969 	}
970 
971 	ctrl->cached = 1;
972 	return 0;
973 }
974 
975 static s32 __uvc_ctrl_get_value(struct uvc_control_mapping *mapping,
976 				const u8 *data)
977 {
978 	s32 value = mapping->get(mapping, UVC_GET_CUR, data);
979 
980 	if (mapping->v4l2_type == V4L2_CTRL_TYPE_MENU) {
981 		const struct uvc_menu_info *menu = mapping->menu_info;
982 		unsigned int i;
983 
984 		for (i = 0; i < mapping->menu_count; ++i, ++menu) {
985 			if (menu->value == value) {
986 				value = i;
987 				break;
988 			}
989 		}
990 	}
991 
992 	return value;
993 }
994 
995 static int __uvc_ctrl_get(struct uvc_video_chain *chain,
996 	struct uvc_control *ctrl, struct uvc_control_mapping *mapping,
997 	s32 *value)
998 {
999 	int ret;
1000 
1001 	if ((ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) == 0)
1002 		return -EACCES;
1003 
1004 	if (!ctrl->loaded) {
1005 		ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR, ctrl->entity->id,
1006 				chain->dev->intfnum, ctrl->info.selector,
1007 				uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
1008 				ctrl->info.size);
1009 		if (ret < 0)
1010 			return ret;
1011 
1012 		ctrl->loaded = 1;
1013 	}
1014 
1015 	*value = __uvc_ctrl_get_value(mapping,
1016 				uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
1017 
1018 	return 0;
1019 }
1020 
1021 static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
1022 	struct uvc_control *ctrl,
1023 	struct uvc_control_mapping *mapping,
1024 	struct v4l2_queryctrl *v4l2_ctrl)
1025 {
1026 	struct uvc_control_mapping *master_map = NULL;
1027 	struct uvc_control *master_ctrl = NULL;
1028 	const struct uvc_menu_info *menu;
1029 	unsigned int i;
1030 
1031 	memset(v4l2_ctrl, 0, sizeof(*v4l2_ctrl));
1032 	v4l2_ctrl->id = mapping->id;
1033 	v4l2_ctrl->type = mapping->v4l2_type;
1034 	strscpy(v4l2_ctrl->name, mapping->name, sizeof(v4l2_ctrl->name));
1035 	v4l2_ctrl->flags = 0;
1036 
1037 	if (!(ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR))
1038 		v4l2_ctrl->flags |= V4L2_CTRL_FLAG_WRITE_ONLY;
1039 	if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR))
1040 		v4l2_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
1041 
1042 	if (mapping->master_id)
1043 		__uvc_find_control(ctrl->entity, mapping->master_id,
1044 				   &master_map, &master_ctrl, 0);
1045 	if (master_ctrl && (master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR)) {
1046 		s32 val;
1047 		int ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val);
1048 		if (ret < 0)
1049 			return ret;
1050 
1051 		if (val != mapping->master_manual)
1052 				v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE;
1053 	}
1054 
1055 	if (!ctrl->cached) {
1056 		int ret = uvc_ctrl_populate_cache(chain, ctrl);
1057 		if (ret < 0)
1058 			return ret;
1059 	}
1060 
1061 	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_DEF) {
1062 		v4l2_ctrl->default_value = mapping->get(mapping, UVC_GET_DEF,
1063 				uvc_ctrl_data(ctrl, UVC_CTRL_DATA_DEF));
1064 	}
1065 
1066 	switch (mapping->v4l2_type) {
1067 	case V4L2_CTRL_TYPE_MENU:
1068 		v4l2_ctrl->minimum = 0;
1069 		v4l2_ctrl->maximum = mapping->menu_count - 1;
1070 		v4l2_ctrl->step = 1;
1071 
1072 		menu = mapping->menu_info;
1073 		for (i = 0; i < mapping->menu_count; ++i, ++menu) {
1074 			if (menu->value == v4l2_ctrl->default_value) {
1075 				v4l2_ctrl->default_value = i;
1076 				break;
1077 			}
1078 		}
1079 
1080 		return 0;
1081 
1082 	case V4L2_CTRL_TYPE_BOOLEAN:
1083 		v4l2_ctrl->minimum = 0;
1084 		v4l2_ctrl->maximum = 1;
1085 		v4l2_ctrl->step = 1;
1086 		return 0;
1087 
1088 	case V4L2_CTRL_TYPE_BUTTON:
1089 		v4l2_ctrl->minimum = 0;
1090 		v4l2_ctrl->maximum = 0;
1091 		v4l2_ctrl->step = 0;
1092 		return 0;
1093 
1094 	default:
1095 		break;
1096 	}
1097 
1098 	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MIN)
1099 		v4l2_ctrl->minimum = mapping->get(mapping, UVC_GET_MIN,
1100 				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN));
1101 
1102 	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MAX)
1103 		v4l2_ctrl->maximum = mapping->get(mapping, UVC_GET_MAX,
1104 				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX));
1105 
1106 	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_RES)
1107 		v4l2_ctrl->step = mapping->get(mapping, UVC_GET_RES,
1108 				  uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
1109 
1110 	return 0;
1111 }
1112 
1113 int uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
1114 	struct v4l2_queryctrl *v4l2_ctrl)
1115 {
1116 	struct uvc_control *ctrl;
1117 	struct uvc_control_mapping *mapping;
1118 	int ret;
1119 
1120 	ret = mutex_lock_interruptible(&chain->ctrl_mutex);
1121 	if (ret < 0)
1122 		return -ERESTARTSYS;
1123 
1124 	ctrl = uvc_find_control(chain, v4l2_ctrl->id, &mapping);
1125 	if (ctrl == NULL) {
1126 		ret = -EINVAL;
1127 		goto done;
1128 	}
1129 
1130 	ret = __uvc_query_v4l2_ctrl(chain, ctrl, mapping, v4l2_ctrl);
1131 done:
1132 	mutex_unlock(&chain->ctrl_mutex);
1133 	return ret;
1134 }
1135 
1136 /*
1137  * Mapping V4L2 controls to UVC controls can be straightforward if done well.
1138  * Most of the UVC controls exist in V4L2, and can be mapped directly. Some
1139  * must be grouped (for instance the Red Balance, Blue Balance and Do White
1140  * Balance V4L2 controls use the White Balance Component UVC control) or
1141  * otherwise translated. The approach we take here is to use a translation
1142  * table for the controls that can be mapped directly, and handle the others
1143  * manually.
1144  */
1145 int uvc_query_v4l2_menu(struct uvc_video_chain *chain,
1146 	struct v4l2_querymenu *query_menu)
1147 {
1148 	const struct uvc_menu_info *menu_info;
1149 	struct uvc_control_mapping *mapping;
1150 	struct uvc_control *ctrl;
1151 	u32 index = query_menu->index;
1152 	u32 id = query_menu->id;
1153 	int ret;
1154 
1155 	memset(query_menu, 0, sizeof(*query_menu));
1156 	query_menu->id = id;
1157 	query_menu->index = index;
1158 
1159 	ret = mutex_lock_interruptible(&chain->ctrl_mutex);
1160 	if (ret < 0)
1161 		return -ERESTARTSYS;
1162 
1163 	ctrl = uvc_find_control(chain, query_menu->id, &mapping);
1164 	if (ctrl == NULL || mapping->v4l2_type != V4L2_CTRL_TYPE_MENU) {
1165 		ret = -EINVAL;
1166 		goto done;
1167 	}
1168 
1169 	if (query_menu->index >= mapping->menu_count) {
1170 		ret = -EINVAL;
1171 		goto done;
1172 	}
1173 
1174 	menu_info = &mapping->menu_info[query_menu->index];
1175 
1176 	if (mapping->data_type == UVC_CTRL_DATA_TYPE_BITMASK &&
1177 	    (ctrl->info.flags & UVC_CTRL_FLAG_GET_RES)) {
1178 		s32 bitmap;
1179 
1180 		if (!ctrl->cached) {
1181 			ret = uvc_ctrl_populate_cache(chain, ctrl);
1182 			if (ret < 0)
1183 				goto done;
1184 		}
1185 
1186 		bitmap = mapping->get(mapping, UVC_GET_RES,
1187 				      uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
1188 		if (!(bitmap & menu_info->value)) {
1189 			ret = -EINVAL;
1190 			goto done;
1191 		}
1192 	}
1193 
1194 	strscpy(query_menu->name, menu_info->name, sizeof(query_menu->name));
1195 
1196 done:
1197 	mutex_unlock(&chain->ctrl_mutex);
1198 	return ret;
1199 }
1200 
1201 /* --------------------------------------------------------------------------
1202  * Ctrl event handling
1203  */
1204 
1205 static void uvc_ctrl_fill_event(struct uvc_video_chain *chain,
1206 	struct v4l2_event *ev,
1207 	struct uvc_control *ctrl,
1208 	struct uvc_control_mapping *mapping,
1209 	s32 value, u32 changes)
1210 {
1211 	struct v4l2_queryctrl v4l2_ctrl;
1212 
1213 	__uvc_query_v4l2_ctrl(chain, ctrl, mapping, &v4l2_ctrl);
1214 
1215 	memset(ev, 0, sizeof(*ev));
1216 	ev->type = V4L2_EVENT_CTRL;
1217 	ev->id = v4l2_ctrl.id;
1218 	ev->u.ctrl.value = value;
1219 	ev->u.ctrl.changes = changes;
1220 	ev->u.ctrl.type = v4l2_ctrl.type;
1221 	ev->u.ctrl.flags = v4l2_ctrl.flags;
1222 	ev->u.ctrl.minimum = v4l2_ctrl.minimum;
1223 	ev->u.ctrl.maximum = v4l2_ctrl.maximum;
1224 	ev->u.ctrl.step = v4l2_ctrl.step;
1225 	ev->u.ctrl.default_value = v4l2_ctrl.default_value;
1226 }
1227 
1228 /*
1229  * Send control change events to all subscribers for the @ctrl control. By
1230  * default the subscriber that generated the event, as identified by @handle,
1231  * is not notified unless it has set the V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK flag.
1232  * @handle can be NULL for asynchronous events related to auto-update controls,
1233  * in which case all subscribers are notified.
1234  */
1235 static void uvc_ctrl_send_event(struct uvc_video_chain *chain,
1236 	struct uvc_fh *handle, struct uvc_control *ctrl,
1237 	struct uvc_control_mapping *mapping, s32 value, u32 changes)
1238 {
1239 	struct v4l2_fh *originator = handle ? &handle->vfh : NULL;
1240 	struct v4l2_subscribed_event *sev;
1241 	struct v4l2_event ev;
1242 
1243 	if (list_empty(&mapping->ev_subs))
1244 		return;
1245 
1246 	uvc_ctrl_fill_event(chain, &ev, ctrl, mapping, value, changes);
1247 
1248 	list_for_each_entry(sev, &mapping->ev_subs, node) {
1249 		if (sev->fh != originator ||
1250 		    (sev->flags & V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK) ||
1251 		    (changes & V4L2_EVENT_CTRL_CH_FLAGS))
1252 			v4l2_event_queue_fh(sev->fh, &ev);
1253 	}
1254 }
1255 
1256 /*
1257  * Send control change events for the slave of the @master control identified
1258  * by the V4L2 ID @slave_id. The @handle identifies the event subscriber that
1259  * generated the event and may be NULL for auto-update events.
1260  */
1261 static void uvc_ctrl_send_slave_event(struct uvc_video_chain *chain,
1262 	struct uvc_fh *handle, struct uvc_control *master, u32 slave_id)
1263 {
1264 	struct uvc_control_mapping *mapping = NULL;
1265 	struct uvc_control *ctrl = NULL;
1266 	u32 changes = V4L2_EVENT_CTRL_CH_FLAGS;
1267 	s32 val = 0;
1268 
1269 	__uvc_find_control(master->entity, slave_id, &mapping, &ctrl, 0);
1270 	if (ctrl == NULL)
1271 		return;
1272 
1273 	if (__uvc_ctrl_get(chain, ctrl, mapping, &val) == 0)
1274 		changes |= V4L2_EVENT_CTRL_CH_VALUE;
1275 
1276 	uvc_ctrl_send_event(chain, handle, ctrl, mapping, val, changes);
1277 }
1278 
1279 static void uvc_ctrl_status_event_work(struct work_struct *work)
1280 {
1281 	struct uvc_device *dev = container_of(work, struct uvc_device,
1282 					      async_ctrl.work);
1283 	struct uvc_ctrl_work *w = &dev->async_ctrl;
1284 	struct uvc_video_chain *chain = w->chain;
1285 	struct uvc_control_mapping *mapping;
1286 	struct uvc_control *ctrl = w->ctrl;
1287 	struct uvc_fh *handle;
1288 	unsigned int i;
1289 	int ret;
1290 
1291 	mutex_lock(&chain->ctrl_mutex);
1292 
1293 	handle = ctrl->handle;
1294 	ctrl->handle = NULL;
1295 
1296 	list_for_each_entry(mapping, &ctrl->info.mappings, list) {
1297 		s32 value = __uvc_ctrl_get_value(mapping, w->data);
1298 
1299 		/*
1300 		 * handle may be NULL here if the device sends auto-update
1301 		 * events without a prior related control set from userspace.
1302 		 */
1303 		for (i = 0; i < ARRAY_SIZE(mapping->slave_ids); ++i) {
1304 			if (!mapping->slave_ids[i])
1305 				break;
1306 
1307 			uvc_ctrl_send_slave_event(chain, handle, ctrl,
1308 						  mapping->slave_ids[i]);
1309 		}
1310 
1311 		uvc_ctrl_send_event(chain, handle, ctrl, mapping, value,
1312 				    V4L2_EVENT_CTRL_CH_VALUE);
1313 	}
1314 
1315 	mutex_unlock(&chain->ctrl_mutex);
1316 
1317 	/* Resubmit the URB. */
1318 	w->urb->interval = dev->int_ep->desc.bInterval;
1319 	ret = usb_submit_urb(w->urb, GFP_KERNEL);
1320 	if (ret < 0)
1321 		uvc_printk(KERN_ERR, "Failed to resubmit status URB (%d).\n",
1322 			   ret);
1323 }
1324 
1325 bool uvc_ctrl_status_event(struct urb *urb, struct uvc_video_chain *chain,
1326 			   struct uvc_control *ctrl, const u8 *data)
1327 {
1328 	struct uvc_device *dev = chain->dev;
1329 	struct uvc_ctrl_work *w = &dev->async_ctrl;
1330 
1331 	if (list_empty(&ctrl->info.mappings)) {
1332 		ctrl->handle = NULL;
1333 		return false;
1334 	}
1335 
1336 	w->data = data;
1337 	w->urb = urb;
1338 	w->chain = chain;
1339 	w->ctrl = ctrl;
1340 
1341 	schedule_work(&w->work);
1342 
1343 	return true;
1344 }
1345 
1346 static bool uvc_ctrl_xctrls_has_control(const struct v4l2_ext_control *xctrls,
1347 					unsigned int xctrls_count, u32 id)
1348 {
1349 	unsigned int i;
1350 
1351 	for (i = 0; i < xctrls_count; ++i) {
1352 		if (xctrls[i].id == id)
1353 			return true;
1354 	}
1355 
1356 	return false;
1357 }
1358 
1359 static void uvc_ctrl_send_events(struct uvc_fh *handle,
1360 	const struct v4l2_ext_control *xctrls, unsigned int xctrls_count)
1361 {
1362 	struct uvc_control_mapping *mapping;
1363 	struct uvc_control *ctrl;
1364 	u32 changes = V4L2_EVENT_CTRL_CH_VALUE;
1365 	unsigned int i;
1366 	unsigned int j;
1367 
1368 	for (i = 0; i < xctrls_count; ++i) {
1369 		ctrl = uvc_find_control(handle->chain, xctrls[i].id, &mapping);
1370 
1371 		if (ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
1372 			/* Notification will be sent from an Interrupt event. */
1373 			continue;
1374 
1375 		for (j = 0; j < ARRAY_SIZE(mapping->slave_ids); ++j) {
1376 			u32 slave_id = mapping->slave_ids[j];
1377 
1378 			if (!slave_id)
1379 				break;
1380 
1381 			/*
1382 			 * We can skip sending an event for the slave if the
1383 			 * slave is being modified in the same transaction.
1384 			 */
1385 			if (uvc_ctrl_xctrls_has_control(xctrls, xctrls_count,
1386 							slave_id))
1387 				continue;
1388 
1389 			uvc_ctrl_send_slave_event(handle->chain, handle, ctrl,
1390 						  slave_id);
1391 		}
1392 
1393 		/*
1394 		 * If the master is being modified in the same transaction
1395 		 * flags may change too.
1396 		 */
1397 		if (mapping->master_id &&
1398 		    uvc_ctrl_xctrls_has_control(xctrls, xctrls_count,
1399 						mapping->master_id))
1400 			changes |= V4L2_EVENT_CTRL_CH_FLAGS;
1401 
1402 		uvc_ctrl_send_event(handle->chain, handle, ctrl, mapping,
1403 				    xctrls[i].value, changes);
1404 	}
1405 }
1406 
1407 static int uvc_ctrl_add_event(struct v4l2_subscribed_event *sev, unsigned elems)
1408 {
1409 	struct uvc_fh *handle = container_of(sev->fh, struct uvc_fh, vfh);
1410 	struct uvc_control_mapping *mapping;
1411 	struct uvc_control *ctrl;
1412 	int ret;
1413 
1414 	ret = mutex_lock_interruptible(&handle->chain->ctrl_mutex);
1415 	if (ret < 0)
1416 		return -ERESTARTSYS;
1417 
1418 	ctrl = uvc_find_control(handle->chain, sev->id, &mapping);
1419 	if (ctrl == NULL) {
1420 		ret = -EINVAL;
1421 		goto done;
1422 	}
1423 
1424 	list_add_tail(&sev->node, &mapping->ev_subs);
1425 	if (sev->flags & V4L2_EVENT_SUB_FL_SEND_INITIAL) {
1426 		struct v4l2_event ev;
1427 		u32 changes = V4L2_EVENT_CTRL_CH_FLAGS;
1428 		s32 val = 0;
1429 
1430 		if (__uvc_ctrl_get(handle->chain, ctrl, mapping, &val) == 0)
1431 			changes |= V4L2_EVENT_CTRL_CH_VALUE;
1432 
1433 		uvc_ctrl_fill_event(handle->chain, &ev, ctrl, mapping, val,
1434 				    changes);
1435 		/* Mark the queue as active, allowing this initial
1436 		   event to be accepted. */
1437 		sev->elems = elems;
1438 		v4l2_event_queue_fh(sev->fh, &ev);
1439 	}
1440 
1441 done:
1442 	mutex_unlock(&handle->chain->ctrl_mutex);
1443 	return ret;
1444 }
1445 
1446 static void uvc_ctrl_del_event(struct v4l2_subscribed_event *sev)
1447 {
1448 	struct uvc_fh *handle = container_of(sev->fh, struct uvc_fh, vfh);
1449 
1450 	mutex_lock(&handle->chain->ctrl_mutex);
1451 	list_del(&sev->node);
1452 	mutex_unlock(&handle->chain->ctrl_mutex);
1453 }
1454 
1455 const struct v4l2_subscribed_event_ops uvc_ctrl_sub_ev_ops = {
1456 	.add = uvc_ctrl_add_event,
1457 	.del = uvc_ctrl_del_event,
1458 	.replace = v4l2_ctrl_replace,
1459 	.merge = v4l2_ctrl_merge,
1460 };
1461 
1462 /* --------------------------------------------------------------------------
1463  * Control transactions
1464  *
1465  * To make extended set operations as atomic as the hardware allows, controls
1466  * are handled using begin/commit/rollback operations.
1467  *
1468  * At the beginning of a set request, uvc_ctrl_begin should be called to
1469  * initialize the request. This function acquires the control lock.
1470  *
1471  * When setting a control, the new value is stored in the control data field
1472  * at position UVC_CTRL_DATA_CURRENT. The control is then marked as dirty for
1473  * later processing. If the UVC and V4L2 control sizes differ, the current
1474  * value is loaded from the hardware before storing the new value in the data
1475  * field.
1476  *
1477  * After processing all controls in the transaction, uvc_ctrl_commit or
1478  * uvc_ctrl_rollback must be called to apply the pending changes to the
1479  * hardware or revert them. When applying changes, all controls marked as
1480  * dirty will be modified in the UVC device, and the dirty flag will be
1481  * cleared. When reverting controls, the control data field
1482  * UVC_CTRL_DATA_CURRENT is reverted to its previous value
1483  * (UVC_CTRL_DATA_BACKUP) for all dirty controls. Both functions release the
1484  * control lock.
1485  */
1486 int uvc_ctrl_begin(struct uvc_video_chain *chain)
1487 {
1488 	return mutex_lock_interruptible(&chain->ctrl_mutex) ? -ERESTARTSYS : 0;
1489 }
1490 
1491 static int uvc_ctrl_commit_entity(struct uvc_device *dev,
1492 	struct uvc_entity *entity, int rollback)
1493 {
1494 	struct uvc_control *ctrl;
1495 	unsigned int i;
1496 	int ret;
1497 
1498 	if (entity == NULL)
1499 		return 0;
1500 
1501 	for (i = 0; i < entity->ncontrols; ++i) {
1502 		ctrl = &entity->controls[i];
1503 		if (!ctrl->initialized)
1504 			continue;
1505 
1506 		/* Reset the loaded flag for auto-update controls that were
1507 		 * marked as loaded in uvc_ctrl_get/uvc_ctrl_set to prevent
1508 		 * uvc_ctrl_get from using the cached value, and for write-only
1509 		 * controls to prevent uvc_ctrl_set from setting bits not
1510 		 * explicitly set by the user.
1511 		 */
1512 		if (ctrl->info.flags & UVC_CTRL_FLAG_AUTO_UPDATE ||
1513 		    !(ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR))
1514 			ctrl->loaded = 0;
1515 
1516 		if (!ctrl->dirty)
1517 			continue;
1518 
1519 		if (!rollback)
1520 			ret = uvc_query_ctrl(dev, UVC_SET_CUR, ctrl->entity->id,
1521 				dev->intfnum, ctrl->info.selector,
1522 				uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
1523 				ctrl->info.size);
1524 		else
1525 			ret = 0;
1526 
1527 		if (rollback || ret < 0)
1528 			memcpy(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
1529 			       uvc_ctrl_data(ctrl, UVC_CTRL_DATA_BACKUP),
1530 			       ctrl->info.size);
1531 
1532 		ctrl->dirty = 0;
1533 
1534 		if (ret < 0)
1535 			return ret;
1536 	}
1537 
1538 	return 0;
1539 }
1540 
1541 int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
1542 		      const struct v4l2_ext_control *xctrls,
1543 		      unsigned int xctrls_count)
1544 {
1545 	struct uvc_video_chain *chain = handle->chain;
1546 	struct uvc_entity *entity;
1547 	int ret = 0;
1548 
1549 	/* Find the control. */
1550 	list_for_each_entry(entity, &chain->entities, chain) {
1551 		ret = uvc_ctrl_commit_entity(chain->dev, entity, rollback);
1552 		if (ret < 0)
1553 			goto done;
1554 	}
1555 
1556 	if (!rollback)
1557 		uvc_ctrl_send_events(handle, xctrls, xctrls_count);
1558 done:
1559 	mutex_unlock(&chain->ctrl_mutex);
1560 	return ret;
1561 }
1562 
1563 int uvc_ctrl_get(struct uvc_video_chain *chain,
1564 	struct v4l2_ext_control *xctrl)
1565 {
1566 	struct uvc_control *ctrl;
1567 	struct uvc_control_mapping *mapping;
1568 
1569 	ctrl = uvc_find_control(chain, xctrl->id, &mapping);
1570 	if (ctrl == NULL)
1571 		return -EINVAL;
1572 
1573 	return __uvc_ctrl_get(chain, ctrl, mapping, &xctrl->value);
1574 }
1575 
1576 int uvc_ctrl_set(struct uvc_fh *handle,
1577 	struct v4l2_ext_control *xctrl)
1578 {
1579 	struct uvc_video_chain *chain = handle->chain;
1580 	struct uvc_control *ctrl;
1581 	struct uvc_control_mapping *mapping;
1582 	s32 value;
1583 	u32 step;
1584 	s32 min;
1585 	s32 max;
1586 	int ret;
1587 
1588 	ctrl = uvc_find_control(chain, xctrl->id, &mapping);
1589 	if (ctrl == NULL)
1590 		return -EINVAL;
1591 	if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR))
1592 		return -EACCES;
1593 
1594 	/* Clamp out of range values. */
1595 	switch (mapping->v4l2_type) {
1596 	case V4L2_CTRL_TYPE_INTEGER:
1597 		if (!ctrl->cached) {
1598 			ret = uvc_ctrl_populate_cache(chain, ctrl);
1599 			if (ret < 0)
1600 				return ret;
1601 		}
1602 
1603 		min = mapping->get(mapping, UVC_GET_MIN,
1604 				   uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN));
1605 		max = mapping->get(mapping, UVC_GET_MAX,
1606 				   uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX));
1607 		step = mapping->get(mapping, UVC_GET_RES,
1608 				    uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
1609 		if (step == 0)
1610 			step = 1;
1611 
1612 		xctrl->value = min + ((u32)(xctrl->value - min) + step / 2)
1613 			     / step * step;
1614 		if (mapping->data_type == UVC_CTRL_DATA_TYPE_SIGNED)
1615 			xctrl->value = clamp(xctrl->value, min, max);
1616 		else
1617 			xctrl->value = clamp_t(u32, xctrl->value, min, max);
1618 		value = xctrl->value;
1619 		break;
1620 
1621 	case V4L2_CTRL_TYPE_BOOLEAN:
1622 		xctrl->value = clamp(xctrl->value, 0, 1);
1623 		value = xctrl->value;
1624 		break;
1625 
1626 	case V4L2_CTRL_TYPE_MENU:
1627 		if (xctrl->value < 0 || xctrl->value >= mapping->menu_count)
1628 			return -ERANGE;
1629 		value = mapping->menu_info[xctrl->value].value;
1630 
1631 		/* Valid menu indices are reported by the GET_RES request for
1632 		 * UVC controls that support it.
1633 		 */
1634 		if (mapping->data_type == UVC_CTRL_DATA_TYPE_BITMASK &&
1635 		    (ctrl->info.flags & UVC_CTRL_FLAG_GET_RES)) {
1636 			if (!ctrl->cached) {
1637 				ret = uvc_ctrl_populate_cache(chain, ctrl);
1638 				if (ret < 0)
1639 					return ret;
1640 			}
1641 
1642 			step = mapping->get(mapping, UVC_GET_RES,
1643 					uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
1644 			if (!(step & value))
1645 				return -EINVAL;
1646 		}
1647 
1648 		break;
1649 
1650 	default:
1651 		value = xctrl->value;
1652 		break;
1653 	}
1654 
1655 	/* If the mapping doesn't span the whole UVC control, the current value
1656 	 * needs to be loaded from the device to perform the read-modify-write
1657 	 * operation.
1658 	 */
1659 	if (!ctrl->loaded && (ctrl->info.size * 8) != mapping->size) {
1660 		if ((ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) == 0) {
1661 			memset(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
1662 				0, ctrl->info.size);
1663 		} else {
1664 			ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR,
1665 				ctrl->entity->id, chain->dev->intfnum,
1666 				ctrl->info.selector,
1667 				uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
1668 				ctrl->info.size);
1669 			if (ret < 0)
1670 				return ret;
1671 		}
1672 
1673 		ctrl->loaded = 1;
1674 	}
1675 
1676 	/* Backup the current value in case we need to rollback later. */
1677 	if (!ctrl->dirty) {
1678 		memcpy(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_BACKUP),
1679 		       uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
1680 		       ctrl->info.size);
1681 	}
1682 
1683 	mapping->set(mapping, value,
1684 		uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
1685 
1686 	if (ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
1687 		ctrl->handle = handle;
1688 
1689 	ctrl->dirty = 1;
1690 	ctrl->modified = 1;
1691 	return 0;
1692 }
1693 
1694 /* --------------------------------------------------------------------------
1695  * Dynamic controls
1696  */
1697 
1698 /*
1699  * Retrieve flags for a given control
1700  */
1701 static int uvc_ctrl_get_flags(struct uvc_device *dev,
1702 			      const struct uvc_control *ctrl,
1703 			      struct uvc_control_info *info)
1704 {
1705 	u8 *data;
1706 	int ret;
1707 
1708 	data = kmalloc(1, GFP_KERNEL);
1709 	if (data == NULL)
1710 		return -ENOMEM;
1711 
1712 	ret = uvc_query_ctrl(dev, UVC_GET_INFO, ctrl->entity->id, dev->intfnum,
1713 			     info->selector, data, 1);
1714 	if (!ret)
1715 		info->flags |= (data[0] & UVC_CONTROL_CAP_GET ?
1716 				UVC_CTRL_FLAG_GET_CUR : 0)
1717 			    |  (data[0] & UVC_CONTROL_CAP_SET ?
1718 				UVC_CTRL_FLAG_SET_CUR : 0)
1719 			    |  (data[0] & UVC_CONTROL_CAP_AUTOUPDATE ?
1720 				UVC_CTRL_FLAG_AUTO_UPDATE : 0)
1721 			    |  (data[0] & UVC_CONTROL_CAP_ASYNCHRONOUS ?
1722 				UVC_CTRL_FLAG_ASYNCHRONOUS : 0);
1723 
1724 	kfree(data);
1725 	return ret;
1726 }
1727 
1728 static void uvc_ctrl_fixup_xu_info(struct uvc_device *dev,
1729 	const struct uvc_control *ctrl, struct uvc_control_info *info)
1730 {
1731 	struct uvc_ctrl_fixup {
1732 		struct usb_device_id id;
1733 		u8 entity;
1734 		u8 selector;
1735 		u8 flags;
1736 	};
1737 
1738 	static const struct uvc_ctrl_fixup fixups[] = {
1739 		{ { USB_DEVICE(0x046d, 0x08c2) }, 9, 1,
1740 			UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX |
1741 			UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_SET_CUR |
1742 			UVC_CTRL_FLAG_AUTO_UPDATE },
1743 		{ { USB_DEVICE(0x046d, 0x08cc) }, 9, 1,
1744 			UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX |
1745 			UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_SET_CUR |
1746 			UVC_CTRL_FLAG_AUTO_UPDATE },
1747 		{ { USB_DEVICE(0x046d, 0x0994) }, 9, 1,
1748 			UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX |
1749 			UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_SET_CUR |
1750 			UVC_CTRL_FLAG_AUTO_UPDATE },
1751 	};
1752 
1753 	unsigned int i;
1754 
1755 	for (i = 0; i < ARRAY_SIZE(fixups); ++i) {
1756 		if (!usb_match_one_id(dev->intf, &fixups[i].id))
1757 			continue;
1758 
1759 		if (fixups[i].entity == ctrl->entity->id &&
1760 		    fixups[i].selector == info->selector) {
1761 			info->flags = fixups[i].flags;
1762 			return;
1763 		}
1764 	}
1765 }
1766 
1767 /*
1768  * Query control information (size and flags) for XU controls.
1769  */
1770 static int uvc_ctrl_fill_xu_info(struct uvc_device *dev,
1771 	const struct uvc_control *ctrl, struct uvc_control_info *info)
1772 {
1773 	u8 *data;
1774 	int ret;
1775 
1776 	data = kmalloc(2, GFP_KERNEL);
1777 	if (data == NULL)
1778 		return -ENOMEM;
1779 
1780 	memcpy(info->entity, ctrl->entity->extension.guidExtensionCode,
1781 	       sizeof(info->entity));
1782 	info->index = ctrl->index;
1783 	info->selector = ctrl->index + 1;
1784 
1785 	/* Query and verify the control length (GET_LEN) */
1786 	ret = uvc_query_ctrl(dev, UVC_GET_LEN, ctrl->entity->id, dev->intfnum,
1787 			     info->selector, data, 2);
1788 	if (ret < 0) {
1789 		uvc_trace(UVC_TRACE_CONTROL,
1790 			  "GET_LEN failed on control %pUl/%u (%d).\n",
1791 			   info->entity, info->selector, ret);
1792 		goto done;
1793 	}
1794 
1795 	info->size = le16_to_cpup((__le16 *)data);
1796 
1797 	info->flags = UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX
1798 		    | UVC_CTRL_FLAG_GET_RES | UVC_CTRL_FLAG_GET_DEF;
1799 
1800 	ret = uvc_ctrl_get_flags(dev, ctrl, info);
1801 	if (ret < 0) {
1802 		uvc_trace(UVC_TRACE_CONTROL,
1803 			  "Failed to get flags for control %pUl/%u (%d).\n",
1804 			  info->entity, info->selector, ret);
1805 		goto done;
1806 	}
1807 
1808 	uvc_ctrl_fixup_xu_info(dev, ctrl, info);
1809 
1810 	uvc_trace(UVC_TRACE_CONTROL, "XU control %pUl/%u queried: len %u, "
1811 		  "flags { get %u set %u auto %u }.\n",
1812 		  info->entity, info->selector, info->size,
1813 		  (info->flags & UVC_CTRL_FLAG_GET_CUR) ? 1 : 0,
1814 		  (info->flags & UVC_CTRL_FLAG_SET_CUR) ? 1 : 0,
1815 		  (info->flags & UVC_CTRL_FLAG_AUTO_UPDATE) ? 1 : 0);
1816 
1817 done:
1818 	kfree(data);
1819 	return ret;
1820 }
1821 
1822 static int uvc_ctrl_add_info(struct uvc_device *dev, struct uvc_control *ctrl,
1823 	const struct uvc_control_info *info);
1824 
1825 static int uvc_ctrl_init_xu_ctrl(struct uvc_device *dev,
1826 	struct uvc_control *ctrl)
1827 {
1828 	struct uvc_control_info info;
1829 	int ret;
1830 
1831 	if (ctrl->initialized)
1832 		return 0;
1833 
1834 	ret = uvc_ctrl_fill_xu_info(dev, ctrl, &info);
1835 	if (ret < 0)
1836 		return ret;
1837 
1838 	ret = uvc_ctrl_add_info(dev, ctrl, &info);
1839 	if (ret < 0)
1840 		uvc_trace(UVC_TRACE_CONTROL, "Failed to initialize control "
1841 			  "%pUl/%u on device %s entity %u\n", info.entity,
1842 			  info.selector, dev->udev->devpath, ctrl->entity->id);
1843 
1844 	return ret;
1845 }
1846 
1847 int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
1848 	struct uvc_xu_control_query *xqry)
1849 {
1850 	struct uvc_entity *entity;
1851 	struct uvc_control *ctrl;
1852 	unsigned int i, found = 0;
1853 	u32 reqflags;
1854 	u16 size;
1855 	u8 *data = NULL;
1856 	int ret;
1857 
1858 	/* Find the extension unit. */
1859 	list_for_each_entry(entity, &chain->entities, chain) {
1860 		if (UVC_ENTITY_TYPE(entity) == UVC_VC_EXTENSION_UNIT &&
1861 		    entity->id == xqry->unit)
1862 			break;
1863 	}
1864 
1865 	if (entity->id != xqry->unit) {
1866 		uvc_trace(UVC_TRACE_CONTROL, "Extension unit %u not found.\n",
1867 			xqry->unit);
1868 		return -ENOENT;
1869 	}
1870 
1871 	/* Find the control and perform delayed initialization if needed. */
1872 	for (i = 0; i < entity->ncontrols; ++i) {
1873 		ctrl = &entity->controls[i];
1874 		if (ctrl->index == xqry->selector - 1) {
1875 			found = 1;
1876 			break;
1877 		}
1878 	}
1879 
1880 	if (!found) {
1881 		uvc_trace(UVC_TRACE_CONTROL, "Control %pUl/%u not found.\n",
1882 			entity->extension.guidExtensionCode, xqry->selector);
1883 		return -ENOENT;
1884 	}
1885 
1886 	if (mutex_lock_interruptible(&chain->ctrl_mutex))
1887 		return -ERESTARTSYS;
1888 
1889 	ret = uvc_ctrl_init_xu_ctrl(chain->dev, ctrl);
1890 	if (ret < 0) {
1891 		ret = -ENOENT;
1892 		goto done;
1893 	}
1894 
1895 	/* Validate the required buffer size and flags for the request */
1896 	reqflags = 0;
1897 	size = ctrl->info.size;
1898 
1899 	switch (xqry->query) {
1900 	case UVC_GET_CUR:
1901 		reqflags = UVC_CTRL_FLAG_GET_CUR;
1902 		break;
1903 	case UVC_GET_MIN:
1904 		reqflags = UVC_CTRL_FLAG_GET_MIN;
1905 		break;
1906 	case UVC_GET_MAX:
1907 		reqflags = UVC_CTRL_FLAG_GET_MAX;
1908 		break;
1909 	case UVC_GET_DEF:
1910 		reqflags = UVC_CTRL_FLAG_GET_DEF;
1911 		break;
1912 	case UVC_GET_RES:
1913 		reqflags = UVC_CTRL_FLAG_GET_RES;
1914 		break;
1915 	case UVC_SET_CUR:
1916 		reqflags = UVC_CTRL_FLAG_SET_CUR;
1917 		break;
1918 	case UVC_GET_LEN:
1919 		size = 2;
1920 		break;
1921 	case UVC_GET_INFO:
1922 		size = 1;
1923 		break;
1924 	default:
1925 		ret = -EINVAL;
1926 		goto done;
1927 	}
1928 
1929 	if (size != xqry->size) {
1930 		ret = -ENOBUFS;
1931 		goto done;
1932 	}
1933 
1934 	if (reqflags && !(ctrl->info.flags & reqflags)) {
1935 		ret = -EBADRQC;
1936 		goto done;
1937 	}
1938 
1939 	data = kmalloc(size, GFP_KERNEL);
1940 	if (data == NULL) {
1941 		ret = -ENOMEM;
1942 		goto done;
1943 	}
1944 
1945 	if (xqry->query == UVC_SET_CUR &&
1946 	    copy_from_user(data, xqry->data, size)) {
1947 		ret = -EFAULT;
1948 		goto done;
1949 	}
1950 
1951 	ret = uvc_query_ctrl(chain->dev, xqry->query, xqry->unit,
1952 			     chain->dev->intfnum, xqry->selector, data, size);
1953 	if (ret < 0)
1954 		goto done;
1955 
1956 	if (xqry->query != UVC_SET_CUR &&
1957 	    copy_to_user(xqry->data, data, size))
1958 		ret = -EFAULT;
1959 done:
1960 	kfree(data);
1961 	mutex_unlock(&chain->ctrl_mutex);
1962 	return ret;
1963 }
1964 
1965 /* --------------------------------------------------------------------------
1966  * Suspend/resume
1967  */
1968 
1969 /*
1970  * Restore control values after resume, skipping controls that haven't been
1971  * changed.
1972  *
1973  * TODO
1974  * - Don't restore modified controls that are back to their default value.
1975  * - Handle restore order (Auto-Exposure Mode should be restored before
1976  *   Exposure Time).
1977  */
1978 int uvc_ctrl_restore_values(struct uvc_device *dev)
1979 {
1980 	struct uvc_control *ctrl;
1981 	struct uvc_entity *entity;
1982 	unsigned int i;
1983 	int ret;
1984 
1985 	/* Walk the entities list and restore controls when possible. */
1986 	list_for_each_entry(entity, &dev->entities, list) {
1987 
1988 		for (i = 0; i < entity->ncontrols; ++i) {
1989 			ctrl = &entity->controls[i];
1990 
1991 			if (!ctrl->initialized || !ctrl->modified ||
1992 			    (ctrl->info.flags & UVC_CTRL_FLAG_RESTORE) == 0)
1993 				continue;
1994 
1995 			printk(KERN_INFO "restoring control %pUl/%u/%u\n",
1996 				ctrl->info.entity, ctrl->info.index,
1997 				ctrl->info.selector);
1998 			ctrl->dirty = 1;
1999 		}
2000 
2001 		ret = uvc_ctrl_commit_entity(dev, entity, 0);
2002 		if (ret < 0)
2003 			return ret;
2004 	}
2005 
2006 	return 0;
2007 }
2008 
2009 /* --------------------------------------------------------------------------
2010  * Control and mapping handling
2011  */
2012 
2013 /*
2014  * Add control information to a given control.
2015  */
2016 static int uvc_ctrl_add_info(struct uvc_device *dev, struct uvc_control *ctrl,
2017 	const struct uvc_control_info *info)
2018 {
2019 	int ret = 0;
2020 
2021 	ctrl->info = *info;
2022 	INIT_LIST_HEAD(&ctrl->info.mappings);
2023 
2024 	/* Allocate an array to save control values (cur, def, max, etc.) */
2025 	ctrl->uvc_data = kzalloc(ctrl->info.size * UVC_CTRL_DATA_LAST + 1,
2026 				 GFP_KERNEL);
2027 	if (ctrl->uvc_data == NULL) {
2028 		ret = -ENOMEM;
2029 		goto done;
2030 	}
2031 
2032 	/*
2033 	 * Retrieve control flags from the device. Ignore errors and work with
2034 	 * default flag values from the uvc_ctrl array when the device doesn't
2035 	 * properly implement GET_INFO on standard controls.
2036 	 */
2037 	uvc_ctrl_get_flags(dev, ctrl, &ctrl->info);
2038 
2039 	ctrl->initialized = 1;
2040 
2041 	uvc_trace(UVC_TRACE_CONTROL, "Added control %pUl/%u to device %s "
2042 		"entity %u\n", ctrl->info.entity, ctrl->info.selector,
2043 		dev->udev->devpath, ctrl->entity->id);
2044 
2045 done:
2046 	if (ret < 0)
2047 		kfree(ctrl->uvc_data);
2048 	return ret;
2049 }
2050 
2051 /*
2052  * Add a control mapping to a given control.
2053  */
2054 static int __uvc_ctrl_add_mapping(struct uvc_device *dev,
2055 	struct uvc_control *ctrl, const struct uvc_control_mapping *mapping)
2056 {
2057 	struct uvc_control_mapping *map;
2058 	unsigned int size;
2059 
2060 	/* Most mappings come from static kernel data and need to be duplicated.
2061 	 * Mappings that come from userspace will be unnecessarily duplicated,
2062 	 * this could be optimized.
2063 	 */
2064 	map = kmemdup(mapping, sizeof(*mapping), GFP_KERNEL);
2065 	if (map == NULL)
2066 		return -ENOMEM;
2067 
2068 	INIT_LIST_HEAD(&map->ev_subs);
2069 
2070 	size = sizeof(*mapping->menu_info) * mapping->menu_count;
2071 	map->menu_info = kmemdup(mapping->menu_info, size, GFP_KERNEL);
2072 	if (map->menu_info == NULL) {
2073 		kfree(map);
2074 		return -ENOMEM;
2075 	}
2076 
2077 	if (map->get == NULL)
2078 		map->get = uvc_get_le_value;
2079 	if (map->set == NULL)
2080 		map->set = uvc_set_le_value;
2081 
2082 	list_add_tail(&map->list, &ctrl->info.mappings);
2083 	uvc_trace(UVC_TRACE_CONTROL,
2084 		"Adding mapping '%s' to control %pUl/%u.\n",
2085 		map->name, ctrl->info.entity, ctrl->info.selector);
2086 
2087 	return 0;
2088 }
2089 
2090 int uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
2091 	const struct uvc_control_mapping *mapping)
2092 {
2093 	struct uvc_device *dev = chain->dev;
2094 	struct uvc_control_mapping *map;
2095 	struct uvc_entity *entity;
2096 	struct uvc_control *ctrl;
2097 	int found = 0;
2098 	int ret;
2099 
2100 	if (mapping->id & ~V4L2_CTRL_ID_MASK) {
2101 		uvc_trace(UVC_TRACE_CONTROL, "Can't add mapping '%s', control "
2102 			"id 0x%08x is invalid.\n", mapping->name,
2103 			mapping->id);
2104 		return -EINVAL;
2105 	}
2106 
2107 	/* Search for the matching (GUID/CS) control on the current chain */
2108 	list_for_each_entry(entity, &chain->entities, chain) {
2109 		unsigned int i;
2110 
2111 		if (UVC_ENTITY_TYPE(entity) != UVC_VC_EXTENSION_UNIT ||
2112 		    !uvc_entity_match_guid(entity, mapping->entity))
2113 			continue;
2114 
2115 		for (i = 0; i < entity->ncontrols; ++i) {
2116 			ctrl = &entity->controls[i];
2117 			if (ctrl->index == mapping->selector - 1) {
2118 				found = 1;
2119 				break;
2120 			}
2121 		}
2122 
2123 		if (found)
2124 			break;
2125 	}
2126 	if (!found)
2127 		return -ENOENT;
2128 
2129 	if (mutex_lock_interruptible(&chain->ctrl_mutex))
2130 		return -ERESTARTSYS;
2131 
2132 	/* Perform delayed initialization of XU controls */
2133 	ret = uvc_ctrl_init_xu_ctrl(dev, ctrl);
2134 	if (ret < 0) {
2135 		ret = -ENOENT;
2136 		goto done;
2137 	}
2138 
2139 	/* Validate the user-provided bit-size and offset */
2140 	if (mapping->size > 32 ||
2141 	    mapping->offset + mapping->size > ctrl->info.size * 8) {
2142 		ret = -EINVAL;
2143 		goto done;
2144 	}
2145 
2146 	list_for_each_entry(map, &ctrl->info.mappings, list) {
2147 		if (mapping->id == map->id) {
2148 			uvc_trace(UVC_TRACE_CONTROL, "Can't add mapping '%s', "
2149 				"control id 0x%08x already exists.\n",
2150 				mapping->name, mapping->id);
2151 			ret = -EEXIST;
2152 			goto done;
2153 		}
2154 	}
2155 
2156 	/* Prevent excess memory consumption */
2157 	if (atomic_inc_return(&dev->nmappings) > UVC_MAX_CONTROL_MAPPINGS) {
2158 		atomic_dec(&dev->nmappings);
2159 		uvc_trace(UVC_TRACE_CONTROL, "Can't add mapping '%s', maximum "
2160 			"mappings count (%u) exceeded.\n", mapping->name,
2161 			UVC_MAX_CONTROL_MAPPINGS);
2162 		ret = -ENOMEM;
2163 		goto done;
2164 	}
2165 
2166 	ret = __uvc_ctrl_add_mapping(dev, ctrl, mapping);
2167 	if (ret < 0)
2168 		atomic_dec(&dev->nmappings);
2169 
2170 done:
2171 	mutex_unlock(&chain->ctrl_mutex);
2172 	return ret;
2173 }
2174 
2175 /*
2176  * Prune an entity of its bogus controls using a blacklist. Bogus controls
2177  * are currently the ones that crash the camera or unconditionally return an
2178  * error when queried.
2179  */
2180 static void uvc_ctrl_prune_entity(struct uvc_device *dev,
2181 	struct uvc_entity *entity)
2182 {
2183 	struct uvc_ctrl_blacklist {
2184 		struct usb_device_id id;
2185 		u8 index;
2186 	};
2187 
2188 	static const struct uvc_ctrl_blacklist processing_blacklist[] = {
2189 		{ { USB_DEVICE(0x13d3, 0x509b) }, 9 }, /* Gain */
2190 		{ { USB_DEVICE(0x1c4f, 0x3000) }, 6 }, /* WB Temperature */
2191 		{ { USB_DEVICE(0x5986, 0x0241) }, 2 }, /* Hue */
2192 	};
2193 	static const struct uvc_ctrl_blacklist camera_blacklist[] = {
2194 		{ { USB_DEVICE(0x06f8, 0x3005) }, 9 }, /* Zoom, Absolute */
2195 	};
2196 
2197 	const struct uvc_ctrl_blacklist *blacklist;
2198 	unsigned int size;
2199 	unsigned int count;
2200 	unsigned int i;
2201 	u8 *controls;
2202 
2203 	switch (UVC_ENTITY_TYPE(entity)) {
2204 	case UVC_VC_PROCESSING_UNIT:
2205 		blacklist = processing_blacklist;
2206 		count = ARRAY_SIZE(processing_blacklist);
2207 		controls = entity->processing.bmControls;
2208 		size = entity->processing.bControlSize;
2209 		break;
2210 
2211 	case UVC_ITT_CAMERA:
2212 		blacklist = camera_blacklist;
2213 		count = ARRAY_SIZE(camera_blacklist);
2214 		controls = entity->camera.bmControls;
2215 		size = entity->camera.bControlSize;
2216 		break;
2217 
2218 	default:
2219 		return;
2220 	}
2221 
2222 	for (i = 0; i < count; ++i) {
2223 		if (!usb_match_one_id(dev->intf, &blacklist[i].id))
2224 			continue;
2225 
2226 		if (blacklist[i].index >= 8 * size ||
2227 		    !uvc_test_bit(controls, blacklist[i].index))
2228 			continue;
2229 
2230 		uvc_trace(UVC_TRACE_CONTROL, "%u/%u control is black listed, "
2231 			"removing it.\n", entity->id, blacklist[i].index);
2232 
2233 		uvc_clear_bit(controls, blacklist[i].index);
2234 	}
2235 }
2236 
2237 /*
2238  * Add control information and hardcoded stock control mappings to the given
2239  * device.
2240  */
2241 static void uvc_ctrl_init_ctrl(struct uvc_device *dev, struct uvc_control *ctrl)
2242 {
2243 	const struct uvc_control_info *info = uvc_ctrls;
2244 	const struct uvc_control_info *iend = info + ARRAY_SIZE(uvc_ctrls);
2245 	const struct uvc_control_mapping *mapping = uvc_ctrl_mappings;
2246 	const struct uvc_control_mapping *mend =
2247 		mapping + ARRAY_SIZE(uvc_ctrl_mappings);
2248 
2249 	/* XU controls initialization requires querying the device for control
2250 	 * information. As some buggy UVC devices will crash when queried
2251 	 * repeatedly in a tight loop, delay XU controls initialization until
2252 	 * first use.
2253 	 */
2254 	if (UVC_ENTITY_TYPE(ctrl->entity) == UVC_VC_EXTENSION_UNIT)
2255 		return;
2256 
2257 	for (; info < iend; ++info) {
2258 		if (uvc_entity_match_guid(ctrl->entity, info->entity) &&
2259 		    ctrl->index == info->index) {
2260 			uvc_ctrl_add_info(dev, ctrl, info);
2261 			break;
2262 		 }
2263 	}
2264 
2265 	if (!ctrl->initialized)
2266 		return;
2267 
2268 	for (; mapping < mend; ++mapping) {
2269 		if (uvc_entity_match_guid(ctrl->entity, mapping->entity) &&
2270 		    ctrl->info.selector == mapping->selector)
2271 			__uvc_ctrl_add_mapping(dev, ctrl, mapping);
2272 	}
2273 }
2274 
2275 /*
2276  * Initialize device controls.
2277  */
2278 int uvc_ctrl_init_device(struct uvc_device *dev)
2279 {
2280 	struct uvc_entity *entity;
2281 	unsigned int i;
2282 
2283 	INIT_WORK(&dev->async_ctrl.work, uvc_ctrl_status_event_work);
2284 
2285 	/* Walk the entities list and instantiate controls */
2286 	list_for_each_entry(entity, &dev->entities, list) {
2287 		struct uvc_control *ctrl;
2288 		unsigned int bControlSize = 0, ncontrols;
2289 		u8 *bmControls = NULL;
2290 
2291 		if (UVC_ENTITY_TYPE(entity) == UVC_VC_EXTENSION_UNIT) {
2292 			bmControls = entity->extension.bmControls;
2293 			bControlSize = entity->extension.bControlSize;
2294 		} else if (UVC_ENTITY_TYPE(entity) == UVC_VC_PROCESSING_UNIT) {
2295 			bmControls = entity->processing.bmControls;
2296 			bControlSize = entity->processing.bControlSize;
2297 		} else if (UVC_ENTITY_TYPE(entity) == UVC_ITT_CAMERA) {
2298 			bmControls = entity->camera.bmControls;
2299 			bControlSize = entity->camera.bControlSize;
2300 		}
2301 
2302 		/* Remove bogus/blacklisted controls */
2303 		uvc_ctrl_prune_entity(dev, entity);
2304 
2305 		/* Count supported controls and allocate the controls array */
2306 		ncontrols = memweight(bmControls, bControlSize);
2307 		if (ncontrols == 0)
2308 			continue;
2309 
2310 		entity->controls = kcalloc(ncontrols, sizeof(*ctrl),
2311 					   GFP_KERNEL);
2312 		if (entity->controls == NULL)
2313 			return -ENOMEM;
2314 		entity->ncontrols = ncontrols;
2315 
2316 		/* Initialize all supported controls */
2317 		ctrl = entity->controls;
2318 		for (i = 0; i < bControlSize * 8; ++i) {
2319 			if (uvc_test_bit(bmControls, i) == 0)
2320 				continue;
2321 
2322 			ctrl->entity = entity;
2323 			ctrl->index = i;
2324 
2325 			uvc_ctrl_init_ctrl(dev, ctrl);
2326 			ctrl++;
2327 		}
2328 	}
2329 
2330 	return 0;
2331 }
2332 
2333 /*
2334  * Cleanup device controls.
2335  */
2336 static void uvc_ctrl_cleanup_mappings(struct uvc_device *dev,
2337 	struct uvc_control *ctrl)
2338 {
2339 	struct uvc_control_mapping *mapping, *nm;
2340 
2341 	list_for_each_entry_safe(mapping, nm, &ctrl->info.mappings, list) {
2342 		list_del(&mapping->list);
2343 		kfree(mapping->menu_info);
2344 		kfree(mapping);
2345 	}
2346 }
2347 
2348 void uvc_ctrl_cleanup_device(struct uvc_device *dev)
2349 {
2350 	struct uvc_entity *entity;
2351 	unsigned int i;
2352 
2353 	cancel_work_sync(&dev->async_ctrl.work);
2354 
2355 	/* Free controls and control mappings for all entities. */
2356 	list_for_each_entry(entity, &dev->entities, list) {
2357 		for (i = 0; i < entity->ncontrols; ++i) {
2358 			struct uvc_control *ctrl = &entity->controls[i];
2359 
2360 			if (!ctrl->initialized)
2361 				continue;
2362 
2363 			uvc_ctrl_cleanup_mappings(dev, ctrl);
2364 			kfree(ctrl->uvc_data);
2365 		}
2366 
2367 		kfree(entity->controls);
2368 	}
2369 }
2370