[media] OMAP_VOUTLIB: Fix wrong resizer calculation
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / media / video / v4l2-common.c
1 /*
2 * Video for Linux Two
3 *
4 * A generic video device interface for the LINUX operating system
5 * using a set of device structures/vectors for low level operations.
6 *
7 * This file replaces the videodev.c file that comes with the
8 * regular kernel distribution.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 *
15 * Author: Bill Dirks <bill@thedirks.org>
16 * based on code by Alan Cox, <alan@cymru.net>
17 *
18 */
19
20 /*
21 * Video capture interface for Linux
22 *
23 * A generic video device interface for the LINUX operating system
24 * using a set of device structures/vectors for low level operations.
25 *
26 * This program is free software; you can redistribute it and/or
27 * modify it under the terms of the GNU General Public License
28 * as published by the Free Software Foundation; either version
29 * 2 of the License, or (at your option) any later version.
30 *
31 * Author: Alan Cox, <alan@lxorguk.ukuu.org.uk>
32 *
33 * Fixes:
34 */
35
36 /*
37 * Video4linux 1/2 integration by Justin Schoeman
38 * <justin@suntiger.ee.up.ac.za>
39 * 2.4 PROCFS support ported from 2.4 kernels by
40 * Iñaki García Etxebarria <garetxe@euskalnet.net>
41 * Makefile fix by "W. Michael Petullo" <mike@flyn.org>
42 * 2.4 devfs support ported from 2.4 kernels by
43 * Dan Merillat <dan@merillat.org>
44 * Added Gerd Knorrs v4l1 enhancements (Justin Schoeman)
45 */
46
47 #include <linux/module.h>
48 #include <linux/types.h>
49 #include <linux/kernel.h>
50 #include <linux/mm.h>
51 #include <linux/string.h>
52 #include <linux/errno.h>
53 #include <linux/i2c.h>
54 #if defined(CONFIG_SPI)
55 #include <linux/spi/spi.h>
56 #endif
57 #include <asm/uaccess.h>
58 #include <asm/system.h>
59 #include <asm/pgtable.h>
60 #include <asm/io.h>
61 #include <asm/div64.h>
62 #include <media/v4l2-common.h>
63 #include <media/v4l2-device.h>
64 #include <media/v4l2-ctrls.h>
65 #include <media/v4l2-chip-ident.h>
66
67 #include <linux/videodev2.h>
68
69 MODULE_AUTHOR("Bill Dirks, Justin Schoeman, Gerd Knorr");
70 MODULE_DESCRIPTION("misc helper functions for v4l2 device drivers");
71 MODULE_LICENSE("GPL");
72
73 /*
74 *
75 * V 4 L 2 D R I V E R H E L P E R A P I
76 *
77 */
78
79 /*
80 * Video Standard Operations (contributed by Michael Schimek)
81 */
82
83 /* Helper functions for control handling */
84
85 /* Check for correctness of the ctrl's value based on the data from
86 struct v4l2_queryctrl and the available menu items. Note that
87 menu_items may be NULL, in that case it is ignored. */
88 int v4l2_ctrl_check(struct v4l2_ext_control *ctrl, struct v4l2_queryctrl *qctrl,
89 const char * const *menu_items)
90 {
91 if (qctrl->flags & V4L2_CTRL_FLAG_DISABLED)
92 return -EINVAL;
93 if (qctrl->flags & V4L2_CTRL_FLAG_GRABBED)
94 return -EBUSY;
95 if (qctrl->type == V4L2_CTRL_TYPE_STRING)
96 return 0;
97 if (qctrl->type == V4L2_CTRL_TYPE_BUTTON ||
98 qctrl->type == V4L2_CTRL_TYPE_INTEGER64 ||
99 qctrl->type == V4L2_CTRL_TYPE_CTRL_CLASS)
100 return 0;
101 if (ctrl->value < qctrl->minimum || ctrl->value > qctrl->maximum)
102 return -ERANGE;
103 if (qctrl->type == V4L2_CTRL_TYPE_MENU && menu_items != NULL) {
104 if (menu_items[ctrl->value] == NULL ||
105 menu_items[ctrl->value][0] == '\0')
106 return -EINVAL;
107 }
108 return 0;
109 }
110 EXPORT_SYMBOL(v4l2_ctrl_check);
111
112 /* Fill in a struct v4l2_queryctrl */
113 int v4l2_ctrl_query_fill(struct v4l2_queryctrl *qctrl, s32 min, s32 max, s32 step, s32 def)
114 {
115 const char *name;
116
117 v4l2_ctrl_fill(qctrl->id, &name, &qctrl->type,
118 &min, &max, &step, &def, &qctrl->flags);
119
120 if (name == NULL)
121 return -EINVAL;
122
123 qctrl->minimum = min;
124 qctrl->maximum = max;
125 qctrl->step = step;
126 qctrl->default_value = def;
127 qctrl->reserved[0] = qctrl->reserved[1] = 0;
128 strlcpy(qctrl->name, name, sizeof(qctrl->name));
129 return 0;
130 }
131 EXPORT_SYMBOL(v4l2_ctrl_query_fill);
132
133 /* Fill in a struct v4l2_querymenu based on the struct v4l2_queryctrl and
134 the menu. The qctrl pointer may be NULL, in which case it is ignored.
135 If menu_items is NULL, then the menu items are retrieved using
136 v4l2_ctrl_get_menu. */
137 int v4l2_ctrl_query_menu(struct v4l2_querymenu *qmenu, struct v4l2_queryctrl *qctrl,
138 const char * const *menu_items)
139 {
140 int i;
141
142 qmenu->reserved = 0;
143 if (menu_items == NULL)
144 menu_items = v4l2_ctrl_get_menu(qmenu->id);
145 if (menu_items == NULL ||
146 (qctrl && (qmenu->index < qctrl->minimum || qmenu->index > qctrl->maximum)))
147 return -EINVAL;
148 for (i = 0; i < qmenu->index && menu_items[i]; i++) ;
149 if (menu_items[i] == NULL || menu_items[i][0] == '\0')
150 return -EINVAL;
151 strlcpy(qmenu->name, menu_items[qmenu->index], sizeof(qmenu->name));
152 return 0;
153 }
154 EXPORT_SYMBOL(v4l2_ctrl_query_menu);
155
156 /* Fill in a struct v4l2_querymenu based on the specified array of valid
157 menu items (terminated by V4L2_CTRL_MENU_IDS_END).
158 Use this if there are 'holes' in the list of valid menu items. */
159 int v4l2_ctrl_query_menu_valid_items(struct v4l2_querymenu *qmenu, const u32 *ids)
160 {
161 const char * const *menu_items = v4l2_ctrl_get_menu(qmenu->id);
162
163 qmenu->reserved = 0;
164 if (menu_items == NULL || ids == NULL)
165 return -EINVAL;
166 while (*ids != V4L2_CTRL_MENU_IDS_END) {
167 if (*ids++ == qmenu->index) {
168 strlcpy(qmenu->name, menu_items[qmenu->index],
169 sizeof(qmenu->name));
170 return 0;
171 }
172 }
173 return -EINVAL;
174 }
175 EXPORT_SYMBOL(v4l2_ctrl_query_menu_valid_items);
176
177 /* ctrl_classes points to an array of u32 pointers, the last element is
178 a NULL pointer. Each u32 array is a 0-terminated array of control IDs.
179 Each array must be sorted low to high and belong to the same control
180 class. The array of u32 pointers must also be sorted, from low class IDs
181 to high class IDs.
182
183 This function returns the first ID that follows after the given ID.
184 When no more controls are available 0 is returned. */
185 u32 v4l2_ctrl_next(const u32 * const * ctrl_classes, u32 id)
186 {
187 u32 ctrl_class = V4L2_CTRL_ID2CLASS(id);
188 const u32 *pctrl;
189
190 if (ctrl_classes == NULL)
191 return 0;
192
193 /* if no query is desired, then check if the ID is part of ctrl_classes */
194 if ((id & V4L2_CTRL_FLAG_NEXT_CTRL) == 0) {
195 /* find class */
196 while (*ctrl_classes && V4L2_CTRL_ID2CLASS(**ctrl_classes) != ctrl_class)
197 ctrl_classes++;
198 if (*ctrl_classes == NULL)
199 return 0;
200 pctrl = *ctrl_classes;
201 /* find control ID */
202 while (*pctrl && *pctrl != id) pctrl++;
203 return *pctrl ? id : 0;
204 }
205 id &= V4L2_CTRL_ID_MASK;
206 id++; /* select next control */
207 /* find first class that matches (or is greater than) the class of
208 the ID */
209 while (*ctrl_classes && V4L2_CTRL_ID2CLASS(**ctrl_classes) < ctrl_class)
210 ctrl_classes++;
211 /* no more classes */
212 if (*ctrl_classes == NULL)
213 return 0;
214 pctrl = *ctrl_classes;
215 /* find first ctrl within the class that is >= ID */
216 while (*pctrl && *pctrl < id) pctrl++;
217 if (*pctrl)
218 return *pctrl;
219 /* we are at the end of the controls of the current class. */
220 /* continue with next class if available */
221 ctrl_classes++;
222 if (*ctrl_classes == NULL)
223 return 0;
224 return **ctrl_classes;
225 }
226 EXPORT_SYMBOL(v4l2_ctrl_next);
227
228 int v4l2_chip_match_host(const struct v4l2_dbg_match *match)
229 {
230 switch (match->type) {
231 case V4L2_CHIP_MATCH_HOST:
232 return match->addr == 0;
233 default:
234 return 0;
235 }
236 }
237 EXPORT_SYMBOL(v4l2_chip_match_host);
238
239 #if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
240 int v4l2_chip_match_i2c_client(struct i2c_client *c, const struct v4l2_dbg_match *match)
241 {
242 int len;
243
244 if (c == NULL || match == NULL)
245 return 0;
246
247 switch (match->type) {
248 case V4L2_CHIP_MATCH_I2C_DRIVER:
249 if (c->driver == NULL || c->driver->driver.name == NULL)
250 return 0;
251 len = strlen(c->driver->driver.name);
252 /* legacy drivers have a ' suffix, don't try to match that */
253 if (len && c->driver->driver.name[len - 1] == '\'')
254 len--;
255 return len && !strncmp(c->driver->driver.name, match->name, len);
256 case V4L2_CHIP_MATCH_I2C_ADDR:
257 return c->addr == match->addr;
258 default:
259 return 0;
260 }
261 }
262 EXPORT_SYMBOL(v4l2_chip_match_i2c_client);
263
264 int v4l2_chip_ident_i2c_client(struct i2c_client *c, struct v4l2_dbg_chip_ident *chip,
265 u32 ident, u32 revision)
266 {
267 if (!v4l2_chip_match_i2c_client(c, &chip->match))
268 return 0;
269 if (chip->ident == V4L2_IDENT_NONE) {
270 chip->ident = ident;
271 chip->revision = revision;
272 }
273 else {
274 chip->ident = V4L2_IDENT_AMBIGUOUS;
275 chip->revision = 0;
276 }
277 return 0;
278 }
279 EXPORT_SYMBOL(v4l2_chip_ident_i2c_client);
280
281 /* ----------------------------------------------------------------- */
282
283 /* I2C Helper functions */
284
285
286 void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client,
287 const struct v4l2_subdev_ops *ops)
288 {
289 v4l2_subdev_init(sd, ops);
290 sd->flags |= V4L2_SUBDEV_FL_IS_I2C;
291 /* the owner is the same as the i2c_client's driver owner */
292 sd->owner = client->driver->driver.owner;
293 /* i2c_client and v4l2_subdev point to one another */
294 v4l2_set_subdevdata(sd, client);
295 i2c_set_clientdata(client, sd);
296 /* initialize name */
297 snprintf(sd->name, sizeof(sd->name), "%s %d-%04x",
298 client->driver->driver.name, i2c_adapter_id(client->adapter),
299 client->addr);
300 }
301 EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_init);
302
303
304
305 /* Load an i2c sub-device. */
306 struct v4l2_subdev *v4l2_i2c_new_subdev_board(struct v4l2_device *v4l2_dev,
307 struct i2c_adapter *adapter, struct i2c_board_info *info,
308 const unsigned short *probe_addrs)
309 {
310 struct v4l2_subdev *sd = NULL;
311 struct i2c_client *client;
312
313 BUG_ON(!v4l2_dev);
314
315 request_module(I2C_MODULE_PREFIX "%s", info->type);
316
317 /* Create the i2c client */
318 if (info->addr == 0 && probe_addrs)
319 client = i2c_new_probed_device(adapter, info, probe_addrs,
320 NULL);
321 else
322 client = i2c_new_device(adapter, info);
323
324 /* Note: by loading the module first we are certain that c->driver
325 will be set if the driver was found. If the module was not loaded
326 first, then the i2c core tries to delay-load the module for us,
327 and then c->driver is still NULL until the module is finally
328 loaded. This delay-load mechanism doesn't work if other drivers
329 want to use the i2c device, so explicitly loading the module
330 is the best alternative. */
331 if (client == NULL || client->driver == NULL)
332 goto error;
333
334 /* Lock the module so we can safely get the v4l2_subdev pointer */
335 if (!try_module_get(client->driver->driver.owner))
336 goto error;
337 sd = i2c_get_clientdata(client);
338
339 /* Register with the v4l2_device which increases the module's
340 use count as well. */
341 if (v4l2_device_register_subdev(v4l2_dev, sd))
342 sd = NULL;
343 /* Decrease the module use count to match the first try_module_get. */
344 module_put(client->driver->driver.owner);
345
346 error:
347 /* If we have a client but no subdev, then something went wrong and
348 we must unregister the client. */
349 if (client && sd == NULL)
350 i2c_unregister_device(client);
351 return sd;
352 }
353 EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev_board);
354
355 struct v4l2_subdev *v4l2_i2c_new_subdev(struct v4l2_device *v4l2_dev,
356 struct i2c_adapter *adapter, const char *client_type,
357 u8 addr, const unsigned short *probe_addrs)
358 {
359 struct i2c_board_info info;
360
361 /* Setup the i2c board info with the device type and
362 the device address. */
363 memset(&info, 0, sizeof(info));
364 strlcpy(info.type, client_type, sizeof(info.type));
365 info.addr = addr;
366
367 return v4l2_i2c_new_subdev_board(v4l2_dev, adapter, &info, probe_addrs);
368 }
369 EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev);
370
371 /* Return i2c client address of v4l2_subdev. */
372 unsigned short v4l2_i2c_subdev_addr(struct v4l2_subdev *sd)
373 {
374 struct i2c_client *client = v4l2_get_subdevdata(sd);
375
376 return client ? client->addr : I2C_CLIENT_END;
377 }
378 EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_addr);
379
380 /* Return a list of I2C tuner addresses to probe. Use only if the tuner
381 addresses are unknown. */
382 const unsigned short *v4l2_i2c_tuner_addrs(enum v4l2_i2c_tuner_type type)
383 {
384 static const unsigned short radio_addrs[] = {
385 #if defined(CONFIG_MEDIA_TUNER_TEA5761) || defined(CONFIG_MEDIA_TUNER_TEA5761_MODULE)
386 0x10,
387 #endif
388 0x60,
389 I2C_CLIENT_END
390 };
391 static const unsigned short demod_addrs[] = {
392 0x42, 0x43, 0x4a, 0x4b,
393 I2C_CLIENT_END
394 };
395 static const unsigned short tv_addrs[] = {
396 0x42, 0x43, 0x4a, 0x4b, /* tda8290 */
397 0x60, 0x61, 0x62, 0x63, 0x64,
398 I2C_CLIENT_END
399 };
400
401 switch (type) {
402 case ADDRS_RADIO:
403 return radio_addrs;
404 case ADDRS_DEMOD:
405 return demod_addrs;
406 case ADDRS_TV:
407 return tv_addrs;
408 case ADDRS_TV_WITH_DEMOD:
409 return tv_addrs + 4;
410 }
411 return NULL;
412 }
413 EXPORT_SYMBOL_GPL(v4l2_i2c_tuner_addrs);
414
415 #endif /* defined(CONFIG_I2C) */
416
417 #if defined(CONFIG_SPI)
418
419 /* Load a spi sub-device. */
420
421 void v4l2_spi_subdev_init(struct v4l2_subdev *sd, struct spi_device *spi,
422 const struct v4l2_subdev_ops *ops)
423 {
424 v4l2_subdev_init(sd, ops);
425 sd->flags |= V4L2_SUBDEV_FL_IS_SPI;
426 /* the owner is the same as the spi_device's driver owner */
427 sd->owner = spi->dev.driver->owner;
428 /* spi_device and v4l2_subdev point to one another */
429 v4l2_set_subdevdata(sd, spi);
430 spi_set_drvdata(spi, sd);
431 /* initialize name */
432 strlcpy(sd->name, spi->dev.driver->name, sizeof(sd->name));
433 }
434 EXPORT_SYMBOL_GPL(v4l2_spi_subdev_init);
435
436 struct v4l2_subdev *v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev,
437 struct spi_master *master, struct spi_board_info *info)
438 {
439 struct v4l2_subdev *sd = NULL;
440 struct spi_device *spi = NULL;
441
442 BUG_ON(!v4l2_dev);
443
444 if (info->modalias)
445 request_module(info->modalias);
446
447 spi = spi_new_device(master, info);
448
449 if (spi == NULL || spi->dev.driver == NULL)
450 goto error;
451
452 if (!try_module_get(spi->dev.driver->owner))
453 goto error;
454
455 sd = spi_get_drvdata(spi);
456
457 /* Register with the v4l2_device which increases the module's
458 use count as well. */
459 if (v4l2_device_register_subdev(v4l2_dev, sd))
460 sd = NULL;
461
462 /* Decrease the module use count to match the first try_module_get. */
463 module_put(spi->dev.driver->owner);
464
465 error:
466 /* If we have a client but no subdev, then something went wrong and
467 we must unregister the client. */
468 if (spi && sd == NULL)
469 spi_unregister_device(spi);
470
471 return sd;
472 }
473 EXPORT_SYMBOL_GPL(v4l2_spi_new_subdev);
474
475 #endif /* defined(CONFIG_SPI) */
476
477 /* Clamp x to be between min and max, aligned to a multiple of 2^align. min
478 * and max don't have to be aligned, but there must be at least one valid
479 * value. E.g., min=17,max=31,align=4 is not allowed as there are no multiples
480 * of 16 between 17 and 31. */
481 static unsigned int clamp_align(unsigned int x, unsigned int min,
482 unsigned int max, unsigned int align)
483 {
484 /* Bits that must be zero to be aligned */
485 unsigned int mask = ~((1 << align) - 1);
486
487 /* Round to nearest aligned value */
488 if (align)
489 x = (x + (1 << (align - 1))) & mask;
490
491 /* Clamp to aligned value of min and max */
492 if (x < min)
493 x = (min + ~mask) & mask;
494 else if (x > max)
495 x = max & mask;
496
497 return x;
498 }
499
500 /* Bound an image to have a width between wmin and wmax, and height between
501 * hmin and hmax, inclusive. Additionally, the width will be a multiple of
502 * 2^walign, the height will be a multiple of 2^halign, and the overall size
503 * (width*height) will be a multiple of 2^salign. The image may be shrunk
504 * or enlarged to fit the alignment constraints.
505 *
506 * The width or height maximum must not be smaller than the corresponding
507 * minimum. The alignments must not be so high there are no possible image
508 * sizes within the allowed bounds. wmin and hmin must be at least 1
509 * (don't use 0). If you don't care about a certain alignment, specify 0,
510 * as 2^0 is 1 and one byte alignment is equivalent to no alignment. If
511 * you only want to adjust downward, specify a maximum that's the same as
512 * the initial value.
513 */
514 void v4l_bound_align_image(u32 *w, unsigned int wmin, unsigned int wmax,
515 unsigned int walign,
516 u32 *h, unsigned int hmin, unsigned int hmax,
517 unsigned int halign, unsigned int salign)
518 {
519 *w = clamp_align(*w, wmin, wmax, walign);
520 *h = clamp_align(*h, hmin, hmax, halign);
521
522 /* Usually we don't need to align the size and are done now. */
523 if (!salign)
524 return;
525
526 /* How much alignment do we have? */
527 walign = __ffs(*w);
528 halign = __ffs(*h);
529 /* Enough to satisfy the image alignment? */
530 if (walign + halign < salign) {
531 /* Max walign where there is still a valid width */
532 unsigned int wmaxa = __fls(wmax ^ (wmin - 1));
533 /* Max halign where there is still a valid height */
534 unsigned int hmaxa = __fls(hmax ^ (hmin - 1));
535
536 /* up the smaller alignment until we have enough */
537 do {
538 if (halign >= hmaxa ||
539 (walign <= halign && walign < wmaxa)) {
540 *w = clamp_align(*w, wmin, wmax, walign + 1);
541 walign = __ffs(*w);
542 } else {
543 *h = clamp_align(*h, hmin, hmax, halign + 1);
544 halign = __ffs(*h);
545 }
546 } while (halign + walign < salign);
547 }
548 }
549 EXPORT_SYMBOL_GPL(v4l_bound_align_image);
550
551 /**
552 * v4l_fill_dv_preset_info - fill description of a digital video preset
553 * @preset - preset value
554 * @info - pointer to struct v4l2_dv_enum_preset
555 *
556 * drivers can use this helper function to fill description of dv preset
557 * in info.
558 */
559 int v4l_fill_dv_preset_info(u32 preset, struct v4l2_dv_enum_preset *info)
560 {
561 static const struct v4l2_dv_preset_info {
562 u16 width;
563 u16 height;
564 const char *name;
565 } dv_presets[] = {
566 { 0, 0, "Invalid" }, /* V4L2_DV_INVALID */
567 { 720, 480, "480p@59.94" }, /* V4L2_DV_480P59_94 */
568 { 720, 576, "576p@50" }, /* V4L2_DV_576P50 */
569 { 1280, 720, "720p@24" }, /* V4L2_DV_720P24 */
570 { 1280, 720, "720p@25" }, /* V4L2_DV_720P25 */
571 { 1280, 720, "720p@30" }, /* V4L2_DV_720P30 */
572 { 1280, 720, "720p@50" }, /* V4L2_DV_720P50 */
573 { 1280, 720, "720p@59.94" }, /* V4L2_DV_720P59_94 */
574 { 1280, 720, "720p@60" }, /* V4L2_DV_720P60 */
575 { 1920, 1080, "1080i@29.97" }, /* V4L2_DV_1080I29_97 */
576 { 1920, 1080, "1080i@30" }, /* V4L2_DV_1080I30 */
577 { 1920, 1080, "1080i@25" }, /* V4L2_DV_1080I25 */
578 { 1920, 1080, "1080i@50" }, /* V4L2_DV_1080I50 */
579 { 1920, 1080, "1080i@60" }, /* V4L2_DV_1080I60 */
580 { 1920, 1080, "1080p@24" }, /* V4L2_DV_1080P24 */
581 { 1920, 1080, "1080p@25" }, /* V4L2_DV_1080P25 */
582 { 1920, 1080, "1080p@30" }, /* V4L2_DV_1080P30 */
583 { 1920, 1080, "1080p@50" }, /* V4L2_DV_1080P50 */
584 { 1920, 1080, "1080p@60" }, /* V4L2_DV_1080P60 */
585 };
586
587 if (info == NULL || preset >= ARRAY_SIZE(dv_presets))
588 return -EINVAL;
589
590 info->preset = preset;
591 info->width = dv_presets[preset].width;
592 info->height = dv_presets[preset].height;
593 strlcpy(info->name, dv_presets[preset].name, sizeof(info->name));
594 return 0;
595 }
596 EXPORT_SYMBOL_GPL(v4l_fill_dv_preset_info);
597
598 const struct v4l2_frmsize_discrete *v4l2_find_nearest_format(
599 const struct v4l2_discrete_probe *probe,
600 s32 width, s32 height)
601 {
602 int i;
603 u32 error, min_error = UINT_MAX;
604 const struct v4l2_frmsize_discrete *size, *best = NULL;
605
606 if (!probe)
607 return best;
608
609 for (i = 0, size = probe->sizes; i < probe->num_sizes; i++, size++) {
610 error = abs(size->width - width) + abs(size->height - height);
611 if (error < min_error) {
612 min_error = error;
613 best = size;
614 }
615 if (!error)
616 break;
617 }
618
619 return best;
620 }
621 EXPORT_SYMBOL_GPL(v4l2_find_nearest_format);