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/pgtable.h>
59 #include <asm/io.h>
60 #include <asm/div64.h>
61 #include <media/v4l2-common.h>
62 #include <media/v4l2-device.h>
63 #include <media/v4l2-ctrls.h>
64 #include <media/v4l2-chip-ident.h>
65 
66 #include <linux/videodev2.h>
67 
68 MODULE_AUTHOR("Bill Dirks, Justin Schoeman, Gerd Knorr");
69 MODULE_DESCRIPTION("misc helper functions for v4l2 device drivers");
70 MODULE_LICENSE("GPL");
71 
72 /*
73  *
74  *	V 4 L 2   D R I V E R   H E L P E R   A P I
75  *
76  */
77 
78 /*
79  *  Video Standard Operations (contributed by Michael Schimek)
80  */
81 
82 /* Helper functions for control handling			     */
83 
84 /* Check for correctness of the ctrl's value based on the data from
85    struct v4l2_queryctrl and the available menu items. Note that
86    menu_items may be NULL, in that case it is ignored. */
87 int v4l2_ctrl_check(struct v4l2_ext_control *ctrl, struct v4l2_queryctrl *qctrl,
88 		const char * const *menu_items)
89 {
90 	if (qctrl->flags & V4L2_CTRL_FLAG_DISABLED)
91 		return -EINVAL;
92 	if (qctrl->flags & V4L2_CTRL_FLAG_GRABBED)
93 		return -EBUSY;
94 	if (qctrl->type == V4L2_CTRL_TYPE_STRING)
95 		return 0;
96 	if (qctrl->type == V4L2_CTRL_TYPE_BUTTON ||
97 	    qctrl->type == V4L2_CTRL_TYPE_INTEGER64 ||
98 	    qctrl->type == V4L2_CTRL_TYPE_CTRL_CLASS)
99 		return 0;
100 	if (ctrl->value < qctrl->minimum || ctrl->value > qctrl->maximum)
101 		return -ERANGE;
102 	if (qctrl->type == V4L2_CTRL_TYPE_MENU && menu_items != NULL) {
103 		if (menu_items[ctrl->value] == NULL ||
104 		    menu_items[ctrl->value][0] == '\0')
105 			return -EINVAL;
106 	}
107 	if (qctrl->type == V4L2_CTRL_TYPE_BITMASK &&
108 			(ctrl->value & ~qctrl->maximum))
109 		return -ERANGE;
110 	return 0;
111 }
112 EXPORT_SYMBOL(v4l2_ctrl_check);
113 
114 /* Fill in a struct v4l2_queryctrl */
115 int v4l2_ctrl_query_fill(struct v4l2_queryctrl *qctrl, s32 min, s32 max, s32 step, s32 def)
116 {
117 	const char *name;
118 
119 	v4l2_ctrl_fill(qctrl->id, &name, &qctrl->type,
120 		       &min, &max, &step, &def, &qctrl->flags);
121 
122 	if (name == NULL)
123 		return -EINVAL;
124 
125 	qctrl->minimum = min;
126 	qctrl->maximum = max;
127 	qctrl->step = step;
128 	qctrl->default_value = def;
129 	qctrl->reserved[0] = qctrl->reserved[1] = 0;
130 	strlcpy(qctrl->name, name, sizeof(qctrl->name));
131 	return 0;
132 }
133 EXPORT_SYMBOL(v4l2_ctrl_query_fill);
134 
135 /* Fill in a struct v4l2_querymenu based on the struct v4l2_queryctrl and
136    the menu. The qctrl pointer may be NULL, in which case it is ignored.
137    If menu_items is NULL, then the menu items are retrieved using
138    v4l2_ctrl_get_menu. */
139 int v4l2_ctrl_query_menu(struct v4l2_querymenu *qmenu, struct v4l2_queryctrl *qctrl,
140 	       const char * const *menu_items)
141 {
142 	int i;
143 
144 	qmenu->reserved = 0;
145 	if (menu_items == NULL)
146 		menu_items = v4l2_ctrl_get_menu(qmenu->id);
147 	if (menu_items == NULL ||
148 	    (qctrl && (qmenu->index < qctrl->minimum || qmenu->index > qctrl->maximum)))
149 		return -EINVAL;
150 	for (i = 0; i < qmenu->index && menu_items[i]; i++) ;
151 	if (menu_items[i] == NULL || menu_items[i][0] == '\0')
152 		return -EINVAL;
153 	strlcpy(qmenu->name, menu_items[qmenu->index], sizeof(qmenu->name));
154 	return 0;
155 }
156 EXPORT_SYMBOL(v4l2_ctrl_query_menu);
157 
158 /* Fill in a struct v4l2_querymenu based on the specified array of valid
159    menu items (terminated by V4L2_CTRL_MENU_IDS_END).
160    Use this if there are 'holes' in the list of valid menu items. */
161 int v4l2_ctrl_query_menu_valid_items(struct v4l2_querymenu *qmenu, const u32 *ids)
162 {
163 	const char * const *menu_items = v4l2_ctrl_get_menu(qmenu->id);
164 
165 	qmenu->reserved = 0;
166 	if (menu_items == NULL || ids == NULL)
167 		return -EINVAL;
168 	while (*ids != V4L2_CTRL_MENU_IDS_END) {
169 		if (*ids++ == qmenu->index) {
170 			strlcpy(qmenu->name, menu_items[qmenu->index],
171 					sizeof(qmenu->name));
172 			return 0;
173 		}
174 	}
175 	return -EINVAL;
176 }
177 EXPORT_SYMBOL(v4l2_ctrl_query_menu_valid_items);
178 
179 /* ctrl_classes points to an array of u32 pointers, the last element is
180    a NULL pointer. Each u32 array is a 0-terminated array of control IDs.
181    Each array must be sorted low to high and belong to the same control
182    class. The array of u32 pointers must also be sorted, from low class IDs
183    to high class IDs.
184 
185    This function returns the first ID that follows after the given ID.
186    When no more controls are available 0 is returned. */
187 u32 v4l2_ctrl_next(const u32 * const * ctrl_classes, u32 id)
188 {
189 	u32 ctrl_class = V4L2_CTRL_ID2CLASS(id);
190 	const u32 *pctrl;
191 
192 	if (ctrl_classes == NULL)
193 		return 0;
194 
195 	/* if no query is desired, then check if the ID is part of ctrl_classes */
196 	if ((id & V4L2_CTRL_FLAG_NEXT_CTRL) == 0) {
197 		/* find class */
198 		while (*ctrl_classes && V4L2_CTRL_ID2CLASS(**ctrl_classes) != ctrl_class)
199 			ctrl_classes++;
200 		if (*ctrl_classes == NULL)
201 			return 0;
202 		pctrl = *ctrl_classes;
203 		/* find control ID */
204 		while (*pctrl && *pctrl != id) pctrl++;
205 		return *pctrl ? id : 0;
206 	}
207 	id &= V4L2_CTRL_ID_MASK;
208 	id++;	/* select next control */
209 	/* find first class that matches (or is greater than) the class of
210 	   the ID */
211 	while (*ctrl_classes && V4L2_CTRL_ID2CLASS(**ctrl_classes) < ctrl_class)
212 		ctrl_classes++;
213 	/* no more classes */
214 	if (*ctrl_classes == NULL)
215 		return 0;
216 	pctrl = *ctrl_classes;
217 	/* find first ctrl within the class that is >= ID */
218 	while (*pctrl && *pctrl < id) pctrl++;
219 	if (*pctrl)
220 		return *pctrl;
221 	/* we are at the end of the controls of the current class. */
222 	/* continue with next class if available */
223 	ctrl_classes++;
224 	if (*ctrl_classes == NULL)
225 		return 0;
226 	return **ctrl_classes;
227 }
228 EXPORT_SYMBOL(v4l2_ctrl_next);
229 
230 int v4l2_chip_match_host(const struct v4l2_dbg_match *match)
231 {
232 	switch (match->type) {
233 	case V4L2_CHIP_MATCH_HOST:
234 		return match->addr == 0;
235 	default:
236 		return 0;
237 	}
238 }
239 EXPORT_SYMBOL(v4l2_chip_match_host);
240 
241 #if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
242 int v4l2_chip_match_i2c_client(struct i2c_client *c, const struct v4l2_dbg_match *match)
243 {
244 	int len;
245 
246 	if (c == NULL || match == NULL)
247 		return 0;
248 
249 	switch (match->type) {
250 	case V4L2_CHIP_MATCH_I2C_DRIVER:
251 		if (c->driver == NULL || c->driver->driver.name == NULL)
252 			return 0;
253 		len = strlen(c->driver->driver.name);
254 		/* legacy drivers have a ' suffix, don't try to match that */
255 		if (len && c->driver->driver.name[len - 1] == '\'')
256 			len--;
257 		return len && !strncmp(c->driver->driver.name, match->name, len);
258 	case V4L2_CHIP_MATCH_I2C_ADDR:
259 		return c->addr == match->addr;
260 	default:
261 		return 0;
262 	}
263 }
264 EXPORT_SYMBOL(v4l2_chip_match_i2c_client);
265 
266 int v4l2_chip_ident_i2c_client(struct i2c_client *c, struct v4l2_dbg_chip_ident *chip,
267 		u32 ident, u32 revision)
268 {
269 	if (!v4l2_chip_match_i2c_client(c, &chip->match))
270 		return 0;
271 	if (chip->ident == V4L2_IDENT_NONE) {
272 		chip->ident = ident;
273 		chip->revision = revision;
274 	}
275 	else {
276 		chip->ident = V4L2_IDENT_AMBIGUOUS;
277 		chip->revision = 0;
278 	}
279 	return 0;
280 }
281 EXPORT_SYMBOL(v4l2_chip_ident_i2c_client);
282 
283 /* ----------------------------------------------------------------- */
284 
285 /* I2C Helper functions */
286 
287 
288 void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client,
289 		const struct v4l2_subdev_ops *ops)
290 {
291 	v4l2_subdev_init(sd, ops);
292 	sd->flags |= V4L2_SUBDEV_FL_IS_I2C;
293 	/* the owner is the same as the i2c_client's driver owner */
294 	sd->owner = client->driver->driver.owner;
295 	/* i2c_client and v4l2_subdev point to one another */
296 	v4l2_set_subdevdata(sd, client);
297 	i2c_set_clientdata(client, sd);
298 	/* initialize name */
299 	snprintf(sd->name, sizeof(sd->name), "%s %d-%04x",
300 		client->driver->driver.name, i2c_adapter_id(client->adapter),
301 		client->addr);
302 }
303 EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_init);
304 
305 
306 
307 /* Load an i2c sub-device. */
308 struct v4l2_subdev *v4l2_i2c_new_subdev_board(struct v4l2_device *v4l2_dev,
309 		struct i2c_adapter *adapter, struct i2c_board_info *info,
310 		const unsigned short *probe_addrs)
311 {
312 	struct v4l2_subdev *sd = NULL;
313 	struct i2c_client *client;
314 
315 	BUG_ON(!v4l2_dev);
316 
317 	request_module(I2C_MODULE_PREFIX "%s", info->type);
318 
319 	/* Create the i2c client */
320 	if (info->addr == 0 && probe_addrs)
321 		client = i2c_new_probed_device(adapter, info, probe_addrs,
322 					       NULL);
323 	else
324 		client = i2c_new_device(adapter, info);
325 
326 	/* Note: by loading the module first we are certain that c->driver
327 	   will be set if the driver was found. If the module was not loaded
328 	   first, then the i2c core tries to delay-load the module for us,
329 	   and then c->driver is still NULL until the module is finally
330 	   loaded. This delay-load mechanism doesn't work if other drivers
331 	   want to use the i2c device, so explicitly loading the module
332 	   is the best alternative. */
333 	if (client == NULL || client->driver == NULL)
334 		goto error;
335 
336 	/* Lock the module so we can safely get the v4l2_subdev pointer */
337 	if (!try_module_get(client->driver->driver.owner))
338 		goto error;
339 	sd = i2c_get_clientdata(client);
340 
341 	/* Register with the v4l2_device which increases the module's
342 	   use count as well. */
343 	if (v4l2_device_register_subdev(v4l2_dev, sd))
344 		sd = NULL;
345 	/* Decrease the module use count to match the first try_module_get. */
346 	module_put(client->driver->driver.owner);
347 
348 error:
349 	/* If we have a client but no subdev, then something went wrong and
350 	   we must unregister the client. */
351 	if (client && sd == NULL)
352 		i2c_unregister_device(client);
353 	return sd;
354 }
355 EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev_board);
356 
357 struct v4l2_subdev *v4l2_i2c_new_subdev(struct v4l2_device *v4l2_dev,
358 		struct i2c_adapter *adapter, const char *client_type,
359 		u8 addr, const unsigned short *probe_addrs)
360 {
361 	struct i2c_board_info info;
362 
363 	/* Setup the i2c board info with the device type and
364 	   the device address. */
365 	memset(&info, 0, sizeof(info));
366 	strlcpy(info.type, client_type, sizeof(info.type));
367 	info.addr = addr;
368 
369 	return v4l2_i2c_new_subdev_board(v4l2_dev, adapter, &info, probe_addrs);
370 }
371 EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev);
372 
373 /* Return i2c client address of v4l2_subdev. */
374 unsigned short v4l2_i2c_subdev_addr(struct v4l2_subdev *sd)
375 {
376 	struct i2c_client *client = v4l2_get_subdevdata(sd);
377 
378 	return client ? client->addr : I2C_CLIENT_END;
379 }
380 EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_addr);
381 
382 /* Return a list of I2C tuner addresses to probe. Use only if the tuner
383    addresses are unknown. */
384 const unsigned short *v4l2_i2c_tuner_addrs(enum v4l2_i2c_tuner_type type)
385 {
386 	static const unsigned short radio_addrs[] = {
387 #if defined(CONFIG_MEDIA_TUNER_TEA5761) || defined(CONFIG_MEDIA_TUNER_TEA5761_MODULE)
388 		0x10,
389 #endif
390 		0x60,
391 		I2C_CLIENT_END
392 	};
393 	static const unsigned short demod_addrs[] = {
394 		0x42, 0x43, 0x4a, 0x4b,
395 		I2C_CLIENT_END
396 	};
397 	static const unsigned short tv_addrs[] = {
398 		0x42, 0x43, 0x4a, 0x4b,		/* tda8290 */
399 		0x60, 0x61, 0x62, 0x63, 0x64,
400 		I2C_CLIENT_END
401 	};
402 
403 	switch (type) {
404 	case ADDRS_RADIO:
405 		return radio_addrs;
406 	case ADDRS_DEMOD:
407 		return demod_addrs;
408 	case ADDRS_TV:
409 		return tv_addrs;
410 	case ADDRS_TV_WITH_DEMOD:
411 		return tv_addrs + 4;
412 	}
413 	return NULL;
414 }
415 EXPORT_SYMBOL_GPL(v4l2_i2c_tuner_addrs);
416 
417 #endif /* defined(CONFIG_I2C) */
418 
419 #if defined(CONFIG_SPI)
420 
421 /* Load an spi sub-device. */
422 
423 void v4l2_spi_subdev_init(struct v4l2_subdev *sd, struct spi_device *spi,
424 		const struct v4l2_subdev_ops *ops)
425 {
426 	v4l2_subdev_init(sd, ops);
427 	sd->flags |= V4L2_SUBDEV_FL_IS_SPI;
428 	/* the owner is the same as the spi_device's driver owner */
429 	sd->owner = spi->dev.driver->owner;
430 	/* spi_device and v4l2_subdev point to one another */
431 	v4l2_set_subdevdata(sd, spi);
432 	spi_set_drvdata(spi, sd);
433 	/* initialize name */
434 	strlcpy(sd->name, spi->dev.driver->name, sizeof(sd->name));
435 }
436 EXPORT_SYMBOL_GPL(v4l2_spi_subdev_init);
437 
438 struct v4l2_subdev *v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev,
439 		struct spi_master *master, struct spi_board_info *info)
440 {
441 	struct v4l2_subdev *sd = NULL;
442 	struct spi_device *spi = NULL;
443 
444 	BUG_ON(!v4l2_dev);
445 
446 	if (info->modalias[0])
447 		request_module(info->modalias);
448 
449 	spi = spi_new_device(master, info);
450 
451 	if (spi == NULL || spi->dev.driver == NULL)
452 		goto error;
453 
454 	if (!try_module_get(spi->dev.driver->owner))
455 		goto error;
456 
457 	sd = spi_get_drvdata(spi);
458 
459 	/* Register with the v4l2_device which increases the module's
460 	   use count as well. */
461 	if (v4l2_device_register_subdev(v4l2_dev, sd))
462 		sd = NULL;
463 
464 	/* Decrease the module use count to match the first try_module_get. */
465 	module_put(spi->dev.driver->owner);
466 
467 error:
468 	/* If we have a client but no subdev, then something went wrong and
469 	   we must unregister the client. */
470 	if (spi && sd == NULL)
471 		spi_unregister_device(spi);
472 
473 	return sd;
474 }
475 EXPORT_SYMBOL_GPL(v4l2_spi_new_subdev);
476 
477 #endif /* defined(CONFIG_SPI) */
478 
479 /* Clamp x to be between min and max, aligned to a multiple of 2^align.  min
480  * and max don't have to be aligned, but there must be at least one valid
481  * value.  E.g., min=17,max=31,align=4 is not allowed as there are no multiples
482  * of 16 between 17 and 31.  */
483 static unsigned int clamp_align(unsigned int x, unsigned int min,
484 				unsigned int max, unsigned int align)
485 {
486 	/* Bits that must be zero to be aligned */
487 	unsigned int mask = ~((1 << align) - 1);
488 
489 	/* Round to nearest aligned value */
490 	if (align)
491 		x = (x + (1 << (align - 1))) & mask;
492 
493 	/* Clamp to aligned value of min and max */
494 	if (x < min)
495 		x = (min + ~mask) & mask;
496 	else if (x > max)
497 		x = max & mask;
498 
499 	return x;
500 }
501 
502 /* Bound an image to have a width between wmin and wmax, and height between
503  * hmin and hmax, inclusive.  Additionally, the width will be a multiple of
504  * 2^walign, the height will be a multiple of 2^halign, and the overall size
505  * (width*height) will be a multiple of 2^salign.  The image may be shrunk
506  * or enlarged to fit the alignment constraints.
507  *
508  * The width or height maximum must not be smaller than the corresponding
509  * minimum.  The alignments must not be so high there are no possible image
510  * sizes within the allowed bounds.  wmin and hmin must be at least 1
511  * (don't use 0).  If you don't care about a certain alignment, specify 0,
512  * as 2^0 is 1 and one byte alignment is equivalent to no alignment.  If
513  * you only want to adjust downward, specify a maximum that's the same as
514  * the initial value.
515  */
516 void v4l_bound_align_image(u32 *w, unsigned int wmin, unsigned int wmax,
517 			   unsigned int walign,
518 			   u32 *h, unsigned int hmin, unsigned int hmax,
519 			   unsigned int halign, unsigned int salign)
520 {
521 	*w = clamp_align(*w, wmin, wmax, walign);
522 	*h = clamp_align(*h, hmin, hmax, halign);
523 
524 	/* Usually we don't need to align the size and are done now. */
525 	if (!salign)
526 		return;
527 
528 	/* How much alignment do we have? */
529 	walign = __ffs(*w);
530 	halign = __ffs(*h);
531 	/* Enough to satisfy the image alignment? */
532 	if (walign + halign < salign) {
533 		/* Max walign where there is still a valid width */
534 		unsigned int wmaxa = __fls(wmax ^ (wmin - 1));
535 		/* Max halign where there is still a valid height */
536 		unsigned int hmaxa = __fls(hmax ^ (hmin - 1));
537 
538 		/* up the smaller alignment until we have enough */
539 		do {
540 			if (halign >= hmaxa ||
541 			    (walign <= halign && walign < wmaxa)) {
542 				*w = clamp_align(*w, wmin, wmax, walign + 1);
543 				walign = __ffs(*w);
544 			} else {
545 				*h = clamp_align(*h, hmin, hmax, halign + 1);
546 				halign = __ffs(*h);
547 			}
548 		} while (halign + walign < salign);
549 	}
550 }
551 EXPORT_SYMBOL_GPL(v4l_bound_align_image);
552 
553 /**
554  * v4l_fill_dv_preset_info - fill description of a digital video preset
555  * @preset - preset value
556  * @info - pointer to struct v4l2_dv_enum_preset
557  *
558  * drivers can use this helper function to fill description of dv preset
559  * in info.
560  */
561 int v4l_fill_dv_preset_info(u32 preset, struct v4l2_dv_enum_preset *info)
562 {
563 	static const struct v4l2_dv_preset_info {
564 		u16 width;
565 		u16 height;
566 		const char *name;
567 	} dv_presets[] = {
568 		{ 0, 0, "Invalid" },		/* V4L2_DV_INVALID */
569 		{ 720,  480, "480p@59.94" },	/* V4L2_DV_480P59_94 */
570 		{ 720,  576, "576p@50" },	/* V4L2_DV_576P50 */
571 		{ 1280, 720, "720p@24" },	/* V4L2_DV_720P24 */
572 		{ 1280, 720, "720p@25" },	/* V4L2_DV_720P25 */
573 		{ 1280, 720, "720p@30" },	/* V4L2_DV_720P30 */
574 		{ 1280, 720, "720p@50" },	/* V4L2_DV_720P50 */
575 		{ 1280, 720, "720p@59.94" },	/* V4L2_DV_720P59_94 */
576 		{ 1280, 720, "720p@60" },	/* V4L2_DV_720P60 */
577 		{ 1920, 1080, "1080i@29.97" },	/* V4L2_DV_1080I29_97 */
578 		{ 1920, 1080, "1080i@30" },	/* V4L2_DV_1080I30 */
579 		{ 1920, 1080, "1080i@25" },	/* V4L2_DV_1080I25 */
580 		{ 1920, 1080, "1080i@50" },	/* V4L2_DV_1080I50 */
581 		{ 1920, 1080, "1080i@60" },	/* V4L2_DV_1080I60 */
582 		{ 1920, 1080, "1080p@24" },	/* V4L2_DV_1080P24 */
583 		{ 1920, 1080, "1080p@25" },	/* V4L2_DV_1080P25 */
584 		{ 1920, 1080, "1080p@30" },	/* V4L2_DV_1080P30 */
585 		{ 1920, 1080, "1080p@50" },	/* V4L2_DV_1080P50 */
586 		{ 1920, 1080, "1080p@60" },	/* V4L2_DV_1080P60 */
587 	};
588 
589 	if (info == NULL || preset >= ARRAY_SIZE(dv_presets))
590 		return -EINVAL;
591 
592 	info->preset = preset;
593 	info->width = dv_presets[preset].width;
594 	info->height = dv_presets[preset].height;
595 	strlcpy(info->name, dv_presets[preset].name, sizeof(info->name));
596 	return 0;
597 }
598 EXPORT_SYMBOL_GPL(v4l_fill_dv_preset_info);
599 
600 /**
601  * v4l_match_dv_timings - check if two timings match
602  * @t1 - compare this v4l2_dv_timings struct...
603  * @t2 - with this struct.
604  * @pclock_delta - the allowed pixelclock deviation.
605  *
606  * Compare t1 with t2 with a given margin of error for the pixelclock.
607  */
608 bool v4l_match_dv_timings(const struct v4l2_dv_timings *t1,
609 			  const struct v4l2_dv_timings *t2,
610 			  unsigned pclock_delta)
611 {
612 	if (t1->type != t2->type || t1->type != V4L2_DV_BT_656_1120)
613 		return false;
614 	if (t1->bt.width == t2->bt.width &&
615 	    t1->bt.height == t2->bt.height &&
616 	    t1->bt.interlaced == t2->bt.interlaced &&
617 	    t1->bt.polarities == t2->bt.polarities &&
618 	    t1->bt.pixelclock >= t2->bt.pixelclock - pclock_delta &&
619 	    t1->bt.pixelclock <= t2->bt.pixelclock + pclock_delta &&
620 	    t1->bt.hfrontporch == t2->bt.hfrontporch &&
621 	    t1->bt.vfrontporch == t2->bt.vfrontporch &&
622 	    t1->bt.vsync == t2->bt.vsync &&
623 	    t1->bt.vbackporch == t2->bt.vbackporch &&
624 	    (!t1->bt.interlaced ||
625 		(t1->bt.il_vfrontporch == t2->bt.il_vfrontporch &&
626 		 t1->bt.il_vsync == t2->bt.il_vsync &&
627 		 t1->bt.il_vbackporch == t2->bt.il_vbackporch)))
628 		return true;
629 	return false;
630 }
631 EXPORT_SYMBOL_GPL(v4l_match_dv_timings);
632 
633 /*
634  * CVT defines
635  * Based on Coordinated Video Timings Standard
636  * version 1.1 September 10, 2003
637  */
638 
639 #define CVT_PXL_CLK_GRAN	250000	/* pixel clock granularity */
640 
641 /* Normal blanking */
642 #define CVT_MIN_V_BPORCH	7	/* lines */
643 #define CVT_MIN_V_PORCH_RND	3	/* lines */
644 #define CVT_MIN_VSYNC_BP	550	/* min time of vsync + back porch (us) */
645 
646 /* Normal blanking for CVT uses GTF to calculate horizontal blanking */
647 #define CVT_CELL_GRAN		8	/* character cell granularity */
648 #define CVT_M			600	/* blanking formula gradient */
649 #define CVT_C			40	/* blanking formula offset */
650 #define CVT_K			128	/* blanking formula scaling factor */
651 #define CVT_J			20	/* blanking formula scaling factor */
652 #define CVT_C_PRIME (((CVT_C - CVT_J) * CVT_K / 256) + CVT_J)
653 #define CVT_M_PRIME (CVT_K * CVT_M / 256)
654 
655 /* Reduced Blanking */
656 #define CVT_RB_MIN_V_BPORCH    7       /* lines  */
657 #define CVT_RB_V_FPORCH        3       /* lines  */
658 #define CVT_RB_MIN_V_BLANK   460     /* us     */
659 #define CVT_RB_H_SYNC         32       /* pixels */
660 #define CVT_RB_H_BPORCH       80       /* pixels */
661 #define CVT_RB_H_BLANK       160       /* pixels */
662 
663 /** v4l2_detect_cvt - detect if the given timings follow the CVT standard
664  * @frame_height - the total height of the frame (including blanking) in lines.
665  * @hfreq - the horizontal frequency in Hz.
666  * @vsync - the height of the vertical sync in lines.
667  * @polarities - the horizontal and vertical polarities (same as struct
668  *		v4l2_bt_timings polarities).
669  * @fmt - the resulting timings.
670  *
671  * This function will attempt to detect if the given values correspond to a
672  * valid CVT format. If so, then it will return true, and fmt will be filled
673  * in with the found CVT timings.
674  */
675 bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
676 		u32 polarities, struct v4l2_dv_timings *fmt)
677 {
678 	int  v_fp, v_bp, h_fp, h_bp, hsync;
679 	int  frame_width, image_height, image_width;
680 	bool reduced_blanking;
681 	unsigned pix_clk;
682 
683 	if (vsync < 4 || vsync > 7)
684 		return false;
685 
686 	if (polarities == V4L2_DV_VSYNC_POS_POL)
687 		reduced_blanking = false;
688 	else if (polarities == V4L2_DV_HSYNC_POS_POL)
689 		reduced_blanking = true;
690 	else
691 		return false;
692 
693 	/* Vertical */
694 	if (reduced_blanking) {
695 		v_fp = CVT_RB_V_FPORCH;
696 		v_bp = (CVT_RB_MIN_V_BLANK * hfreq + 999999) / 1000000;
697 		v_bp -= vsync + v_fp;
698 
699 		if (v_bp < CVT_RB_MIN_V_BPORCH)
700 			v_bp = CVT_RB_MIN_V_BPORCH;
701 	} else {
702 		v_fp = CVT_MIN_V_PORCH_RND;
703 		v_bp = (CVT_MIN_VSYNC_BP * hfreq + 999999) / 1000000 - vsync;
704 
705 		if (v_bp < CVT_MIN_V_BPORCH)
706 			v_bp = CVT_MIN_V_BPORCH;
707 	}
708 	image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
709 
710 	/* Aspect ratio based on vsync */
711 	switch (vsync) {
712 	case 4:
713 		image_width = (image_height * 4) / 3;
714 		break;
715 	case 5:
716 		image_width = (image_height * 16) / 9;
717 		break;
718 	case 6:
719 		image_width = (image_height * 16) / 10;
720 		break;
721 	case 7:
722 		/* special case */
723 		if (image_height == 1024)
724 			image_width = (image_height * 5) / 4;
725 		else if (image_height == 768)
726 			image_width = (image_height * 15) / 9;
727 		else
728 			return false;
729 		break;
730 	default:
731 		return false;
732 	}
733 
734 	image_width = image_width & ~7;
735 
736 	/* Horizontal */
737 	if (reduced_blanking) {
738 		pix_clk = (image_width + CVT_RB_H_BLANK) * hfreq;
739 		pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;
740 
741 		h_bp = CVT_RB_H_BPORCH;
742 		hsync = CVT_RB_H_SYNC;
743 		h_fp = CVT_RB_H_BLANK - h_bp - hsync;
744 
745 		frame_width = image_width + CVT_RB_H_BLANK;
746 	} else {
747 		int h_blank;
748 		unsigned ideal_duty_cycle = CVT_C_PRIME - (CVT_M_PRIME * 1000) / hfreq;
749 
750 		h_blank = (image_width * ideal_duty_cycle + (100 - ideal_duty_cycle) / 2) /
751 						(100 - ideal_duty_cycle);
752 		h_blank = h_blank - h_blank % (2 * CVT_CELL_GRAN);
753 
754 		if (h_blank * 100 / image_width < 20) {
755 			h_blank = image_width / 5;
756 			h_blank = (h_blank + 0x7) & ~0x7;
757 		}
758 
759 		pix_clk = (image_width + h_blank) * hfreq;
760 		pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;
761 
762 		h_bp = h_blank / 2;
763 		frame_width = image_width + h_blank;
764 
765 		hsync = (frame_width * 8 + 50) / 100;
766 		hsync = hsync - hsync % CVT_CELL_GRAN;
767 		h_fp = h_blank - hsync - h_bp;
768 	}
769 
770 	fmt->bt.polarities = polarities;
771 	fmt->bt.width = image_width;
772 	fmt->bt.height = image_height;
773 	fmt->bt.hfrontporch = h_fp;
774 	fmt->bt.vfrontporch = v_fp;
775 	fmt->bt.hsync = hsync;
776 	fmt->bt.vsync = vsync;
777 	fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
778 	fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
779 	fmt->bt.pixelclock = pix_clk;
780 	fmt->bt.standards = V4L2_DV_BT_STD_CVT;
781 	if (reduced_blanking)
782 		fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
783 	return true;
784 }
785 EXPORT_SYMBOL_GPL(v4l2_detect_cvt);
786 
787 /*
788  * GTF defines
789  * Based on Generalized Timing Formula Standard
790  * Version 1.1 September 2, 1999
791  */
792 
793 #define GTF_PXL_CLK_GRAN	250000	/* pixel clock granularity */
794 
795 #define GTF_MIN_VSYNC_BP	550	/* min time of vsync + back porch (us) */
796 #define GTF_V_FP		1	/* vertical front porch (lines) */
797 #define GTF_CELL_GRAN		8	/* character cell granularity */
798 
799 /* Default */
800 #define GTF_D_M			600	/* blanking formula gradient */
801 #define GTF_D_C			40	/* blanking formula offset */
802 #define GTF_D_K			128	/* blanking formula scaling factor */
803 #define GTF_D_J			20	/* blanking formula scaling factor */
804 #define GTF_D_C_PRIME ((((GTF_D_C - GTF_D_J) * GTF_D_K) / 256) + GTF_D_J)
805 #define GTF_D_M_PRIME ((GTF_D_K * GTF_D_M) / 256)
806 
807 /* Secondary */
808 #define GTF_S_M			3600	/* blanking formula gradient */
809 #define GTF_S_C			40	/* blanking formula offset */
810 #define GTF_S_K			128	/* blanking formula scaling factor */
811 #define GTF_S_J			35	/* blanking formula scaling factor */
812 #define GTF_S_C_PRIME ((((GTF_S_C - GTF_S_J) * GTF_S_K) / 256) + GTF_S_J)
813 #define GTF_S_M_PRIME ((GTF_S_K * GTF_S_M) / 256)
814 
815 /** v4l2_detect_gtf - detect if the given timings follow the GTF standard
816  * @frame_height - the total height of the frame (including blanking) in lines.
817  * @hfreq - the horizontal frequency in Hz.
818  * @vsync - the height of the vertical sync in lines.
819  * @polarities - the horizontal and vertical polarities (same as struct
820  *		v4l2_bt_timings polarities).
821  * @aspect - preferred aspect ratio. GTF has no method of determining the
822  *		aspect ratio in order to derive the image width from the
823  *		image height, so it has to be passed explicitly. Usually
824  *		the native screen aspect ratio is used for this. If it
825  *		is not filled in correctly, then 16:9 will be assumed.
826  * @fmt - the resulting timings.
827  *
828  * This function will attempt to detect if the given values correspond to a
829  * valid GTF format. If so, then it will return true, and fmt will be filled
830  * in with the found GTF timings.
831  */
832 bool v4l2_detect_gtf(unsigned frame_height,
833 		unsigned hfreq,
834 		unsigned vsync,
835 		u32 polarities,
836 		struct v4l2_fract aspect,
837 		struct v4l2_dv_timings *fmt)
838 {
839 	int pix_clk;
840 	int  v_fp, v_bp, h_fp, h_bp, hsync;
841 	int frame_width, image_height, image_width;
842 	bool default_gtf;
843 	int h_blank;
844 
845 	if (vsync != 3)
846 		return false;
847 
848 	if (polarities == V4L2_DV_VSYNC_POS_POL)
849 		default_gtf = true;
850 	else if (polarities == V4L2_DV_HSYNC_POS_POL)
851 		default_gtf = false;
852 	else
853 		return false;
854 
855 	/* Vertical */
856 	v_fp = GTF_V_FP;
857 	v_bp = (GTF_MIN_VSYNC_BP * hfreq + 999999) / 1000000 - vsync;
858 	image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
859 
860 	if (aspect.numerator == 0 || aspect.denominator == 0) {
861 		aspect.numerator = 16;
862 		aspect.denominator = 9;
863 	}
864 	image_width = ((image_height * aspect.numerator) / aspect.denominator);
865 
866 	/* Horizontal */
867 	if (default_gtf)
868 		h_blank = ((image_width * GTF_D_C_PRIME * hfreq) -
869 					(image_width * GTF_D_M_PRIME * 1000) +
870 			(hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) / 2) /
871 			(hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000);
872 	else
873 		h_blank = ((image_width * GTF_S_C_PRIME * hfreq) -
874 					(image_width * GTF_S_M_PRIME * 1000) +
875 			(hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) / 2) /
876 			(hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000);
877 
878 	h_blank = h_blank - h_blank % (2 * GTF_CELL_GRAN);
879 	frame_width = image_width + h_blank;
880 
881 	pix_clk = (image_width + h_blank) * hfreq;
882 	pix_clk = pix_clk / GTF_PXL_CLK_GRAN * GTF_PXL_CLK_GRAN;
883 
884 	hsync = (frame_width * 8 + 50) / 100;
885 	hsync = hsync - hsync % GTF_CELL_GRAN;
886 
887 	h_fp = h_blank / 2 - hsync;
888 	h_bp = h_blank / 2;
889 
890 	fmt->bt.polarities = polarities;
891 	fmt->bt.width = image_width;
892 	fmt->bt.height = image_height;
893 	fmt->bt.hfrontporch = h_fp;
894 	fmt->bt.vfrontporch = v_fp;
895 	fmt->bt.hsync = hsync;
896 	fmt->bt.vsync = vsync;
897 	fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
898 	fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
899 	fmt->bt.pixelclock = pix_clk;
900 	fmt->bt.standards = V4L2_DV_BT_STD_GTF;
901 	if (!default_gtf)
902 		fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
903 	return true;
904 }
905 EXPORT_SYMBOL_GPL(v4l2_detect_gtf);
906 
907 /** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
908  *	0x15 and 0x16 from the EDID.
909  * @hor_landscape - byte 0x15 from the EDID.
910  * @vert_portrait - byte 0x16 from the EDID.
911  *
912  * Determines the aspect ratio from the EDID.
913  * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
914  * "Horizontal and Vertical Screen Size or Aspect Ratio"
915  */
916 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait)
917 {
918 	struct v4l2_fract aspect = { 16, 9 };
919 	u32 tmp;
920 	u8 ratio;
921 
922 	/* Nothing filled in, fallback to 16:9 */
923 	if (!hor_landscape && !vert_portrait)
924 		return aspect;
925 	/* Both filled in, so they are interpreted as the screen size in cm */
926 	if (hor_landscape && vert_portrait) {
927 		aspect.numerator = hor_landscape;
928 		aspect.denominator = vert_portrait;
929 		return aspect;
930 	}
931 	/* Only one is filled in, so interpret them as a ratio:
932 	   (val + 99) / 100 */
933 	ratio = hor_landscape | vert_portrait;
934 	/* Change some rounded values into the exact aspect ratio */
935 	if (ratio == 79) {
936 		aspect.numerator = 16;
937 		aspect.denominator = 9;
938 	} else if (ratio == 34) {
939 		aspect.numerator = 4;
940 		aspect.numerator = 3;
941 	} else if (ratio == 68) {
942 		aspect.numerator = 15;
943 		aspect.numerator = 9;
944 	} else {
945 		aspect.numerator = hor_landscape + 99;
946 		aspect.denominator = 100;
947 	}
948 	if (hor_landscape)
949 		return aspect;
950 	/* The aspect ratio is for portrait, so swap numerator and denominator */
951 	tmp = aspect.denominator;
952 	aspect.denominator = aspect.numerator;
953 	aspect.numerator = tmp;
954 	return aspect;
955 }
956 EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio);
957 
958 const struct v4l2_frmsize_discrete *v4l2_find_nearest_format(
959 		const struct v4l2_discrete_probe *probe,
960 		s32 width, s32 height)
961 {
962 	int i;
963 	u32 error, min_error = UINT_MAX;
964 	const struct v4l2_frmsize_discrete *size, *best = NULL;
965 
966 	if (!probe)
967 		return best;
968 
969 	for (i = 0, size = probe->sizes; i < probe->num_sizes; i++, size++) {
970 		error = abs(size->width - width) + abs(size->height - height);
971 		if (error < min_error) {
972 			min_error = error;
973 			best = size;
974 		}
975 		if (!error)
976 			break;
977 	}
978 
979 	return best;
980 }
981 EXPORT_SYMBOL_GPL(v4l2_find_nearest_format);
982