1/*
2 * v4l2-dv-timings - Internal header with dv-timings helper functions
3 *
4 * Copyright 2013 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
5 *
6 * This program is free software; you may redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
11 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
12 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
13 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
14 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
15 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
16 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
17 * SOFTWARE.
18 *
19 */
20
21#ifndef __V4L2_DV_TIMINGS_H
22#define __V4L2_DV_TIMINGS_H
23
24#include <linux/videodev2.h>
25
26/** v4l2_dv_timings_presets: list of all dv_timings presets.
27 */
28extern const struct v4l2_dv_timings v4l2_dv_timings_presets[];
29
30/** v4l2_check_dv_timings_fnc - timings check callback
31 * @t: the v4l2_dv_timings struct.
32 * @handle: a handle from the driver.
33 *
34 * Returns true if the given timings are valid.
35 */
36typedef bool v4l2_check_dv_timings_fnc(const struct v4l2_dv_timings *t, void *handle);
37
38/** v4l2_valid_dv_timings() - are these timings valid?
39  * @t:	  the v4l2_dv_timings struct.
40  * @cap: the v4l2_dv_timings_cap capabilities.
41  * @fnc: callback to check if this timing is OK. May be NULL.
42  * @fnc_handle: a handle that is passed on to @fnc.
43  *
44  * Returns true if the given dv_timings struct is supported by the
45  * hardware capabilities and the callback function (if non-NULL), returns
46  * false otherwise.
47  */
48bool v4l2_valid_dv_timings(const struct v4l2_dv_timings *t,
49			   const struct v4l2_dv_timings_cap *cap,
50			   v4l2_check_dv_timings_fnc fnc,
51			   void *fnc_handle);
52
53/** v4l2_enum_dv_timings_cap() - Helper function to enumerate possible DV timings based on capabilities
54  * @t:	  the v4l2_enum_dv_timings struct.
55  * @cap: the v4l2_dv_timings_cap capabilities.
56  * @fnc: callback to check if this timing is OK. May be NULL.
57  * @fnc_handle: a handle that is passed on to @fnc.
58  *
59  * This enumerates dv_timings using the full list of possible CEA-861 and DMT
60  * timings, filtering out any timings that are not supported based on the
61  * hardware capabilities and the callback function (if non-NULL).
62  *
63  * If a valid timing for the given index is found, it will fill in @t and
64  * return 0, otherwise it returns -EINVAL.
65  */
66int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
67			     const struct v4l2_dv_timings_cap *cap,
68			     v4l2_check_dv_timings_fnc fnc,
69			     void *fnc_handle);
70
71/** v4l2_find_dv_timings_cap() - Find the closest timings struct
72  * @t:	  the v4l2_enum_dv_timings struct.
73  * @cap: the v4l2_dv_timings_cap capabilities.
74  * @pclock_delta: maximum delta between t->pixelclock and the timing struct
75  *		under consideration.
76  * @fnc: callback to check if a given timings struct is OK. May be NULL.
77  * @fnc_handle: a handle that is passed on to @fnc.
78  *
79  * This function tries to map the given timings to an entry in the
80  * full list of possible CEA-861 and DMT timings, filtering out any timings
81  * that are not supported based on the hardware capabilities and the callback
82  * function (if non-NULL).
83  *
84  * On success it will fill in @t with the found timings and it returns true.
85  * On failure it will return false.
86  */
87bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
88			      const struct v4l2_dv_timings_cap *cap,
89			      unsigned pclock_delta,
90			      v4l2_check_dv_timings_fnc fnc,
91			      void *fnc_handle);
92
93/** v4l2_match_dv_timings() - do two timings match?
94  * @measured:	  the measured timings data.
95  * @standard:	  the timings according to the standard.
96  * @pclock_delta: maximum delta in Hz between standard->pixelclock and
97  * 		the measured timings.
98  *
99  * Returns true if the two timings match, returns false otherwise.
100  */
101bool v4l2_match_dv_timings(const struct v4l2_dv_timings *measured,
102			   const struct v4l2_dv_timings *standard,
103			   unsigned pclock_delta);
104
105/** v4l2_print_dv_timings() - log the contents of a dv_timings struct
106  * @dev_prefix:device prefix for each log line.
107  * @prefix:	additional prefix for each log line, may be NULL.
108  * @t:		the timings data.
109  * @detailed:	if true, give a detailed log.
110  */
111void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
112			   const struct v4l2_dv_timings *t, bool detailed);
113
114/** v4l2_detect_cvt - detect if the given timings follow the CVT standard
115 * @frame_height - the total height of the frame (including blanking) in lines.
116 * @hfreq - the horizontal frequency in Hz.
117 * @vsync - the height of the vertical sync in lines.
118 * @polarities - the horizontal and vertical polarities (same as struct
119 *		v4l2_bt_timings polarities).
120 * @fmt - the resulting timings.
121 *
122 * This function will attempt to detect if the given values correspond to a
123 * valid CVT format. If so, then it will return true, and fmt will be filled
124 * in with the found CVT timings.
125 */
126bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
127		u32 polarities, struct v4l2_dv_timings *fmt);
128
129/** v4l2_detect_gtf - detect if the given timings follow the GTF standard
130 * @frame_height - the total height of the frame (including blanking) in lines.
131 * @hfreq - the horizontal frequency in Hz.
132 * @vsync - the height of the vertical sync in lines.
133 * @polarities - the horizontal and vertical polarities (same as struct
134 *		v4l2_bt_timings polarities).
135 * @aspect - preferred aspect ratio. GTF has no method of determining the
136 *		aspect ratio in order to derive the image width from the
137 *		image height, so it has to be passed explicitly. Usually
138 *		the native screen aspect ratio is used for this. If it
139 *		is not filled in correctly, then 16:9 will be assumed.
140 * @fmt - the resulting timings.
141 *
142 * This function will attempt to detect if the given values correspond to a
143 * valid GTF format. If so, then it will return true, and fmt will be filled
144 * in with the found GTF timings.
145 */
146bool v4l2_detect_gtf(unsigned frame_height, unsigned hfreq, unsigned vsync,
147		u32 polarities, struct v4l2_fract aspect,
148		struct v4l2_dv_timings *fmt);
149
150/** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
151 *	0x15 and 0x16 from the EDID.
152 * @hor_landscape - byte 0x15 from the EDID.
153 * @vert_portrait - byte 0x16 from the EDID.
154 *
155 * Determines the aspect ratio from the EDID.
156 * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
157 * "Horizontal and Vertical Screen Size or Aspect Ratio"
158 */
159struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait);
160
161#endif
162