summaryrefslogtreecommitdiff
path: root/include/media/v4l2-dv-timings.h
blob: 8778263a8f5d21b45cfc7c530af63d982f002fe9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * v4l2-dv-timings - Internal header with dv-timings helper functions
 *
 * Copyright 2013 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
 */

#ifndef __V4L2_DV_TIMINGS_H
#define __V4L2_DV_TIMINGS_H

#include <linux/videodev2.h>

/*
 * v4l2_dv_timings_presets: list of all dv_timings presets.
 */
extern const struct v4l2_dv_timings v4l2_dv_timings_presets[];

/**
 * typedef v4l2_check_dv_timings_fnc - timings check callback
 *
 * @t: the v4l2_dv_timings struct.
 * @handle: a handle from the driver.
 *
 * Returns true if the given timings are valid.
 */
typedef bool v4l2_check_dv_timings_fnc(const struct v4l2_dv_timings *t, void *handle);

/**
 * v4l2_valid_dv_timings() - are these timings valid?
 *
 * @t:	  the v4l2_dv_timings struct.
 * @cap: the v4l2_dv_timings_cap capabilities.
 * @fnc: callback to check if this timing is OK. May be NULL.
 * @fnc_handle: a handle that is passed on to @fnc.
 *
 * Returns true if the given dv_timings struct is supported by the
 * hardware capabilities and the callback function (if non-NULL), returns
 * false otherwise.
 */
bool v4l2_valid_dv_timings(const struct v4l2_dv_timings *t,
			   const struct v4l2_dv_timings_cap *cap,
			   v4l2_check_dv_timings_fnc fnc,
			   void *fnc_handle);

/**
 * v4l2_enum_dv_timings_cap() - Helper function to enumerate possible DV
 *	 timings based on capabilities
 *
 * @t:	  the v4l2_enum_dv_timings struct.
 * @cap: the v4l2_dv_timings_cap capabilities.
 * @fnc: callback to check if this timing is OK. May be NULL.
 * @fnc_handle: a handle that is passed on to @fnc.
 *
 * This enumerates dv_timings using the full list of possible CEA-861 and DMT
 * timings, filtering out any timings that are not supported based on the
 * hardware capabilities and the callback function (if non-NULL).
 *
 * If a valid timing for the given index is found, it will fill in @t and
 * return 0, otherwise it returns -EINVAL.
 */
int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
			     const struct v4l2_dv_timings_cap *cap,
			     v4l2_check_dv_timings_fnc fnc,
			     void *fnc_handle);

/**
 * v4l2_find_dv_timings_cap() - Find the closest timings struct
 *
 * @t:	  the v4l2_enum_dv_timings struct.
 * @cap: the v4l2_dv_timings_cap capabilities.
 * @pclock_delta: maximum delta between t->pixelclock and the timing struct
 *		under consideration.
 * @fnc: callback to check if a given timings struct is OK. May be NULL.
 * @fnc_handle: a handle that is passed on to @fnc.
 *
 * This function tries to map the given timings to an entry in the
 * full list of possible CEA-861 and DMT timings, filtering out any timings
 * that are not supported based on the hardware capabilities and the callback
 * function (if non-NULL).
 *
 * On success it will fill in @t with the found timings and it returns true.
 * On failure it will return false.
 */
bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
			      const struct v4l2_dv_timings_cap *cap,
			      unsigned pclock_delta,
			      v4l2_check_dv_timings_fnc fnc,
			      void *fnc_handle);

/**
 * v4l2_find_dv_timings_cea861_vic() - find timings based on CEA-861 VIC
 * @t:		the timings data.
 * @vic:	CEA-861 VIC code
 *
 * On success it will fill in @t with the found timings and it returns true.
 * On failure it will return false.
 */
bool v4l2_find_dv_timings_cea861_vic(struct v4l2_dv_timings *t, u8 vic);

/**
 * v4l2_match_dv_timings() - do two timings match?
 *
 * @measured:	  the measured timings data.
 * @standard:	  the timings according to the standard.
 * @pclock_delta: maximum delta in Hz between standard->pixelclock and
 *		the measured timings.
 * @match_reduced_fps: if true, then fail if V4L2_DV_FL_REDUCED_FPS does not
 * match.
 *
 * Returns true if the two timings match, returns false otherwise.
 */
bool v4l2_match_dv_timings(const struct v4l2_dv_timings *measured,
			   const struct v4l2_dv_timings *standard,
			   unsigned pclock_delta, bool match_reduced_fps);

/**
 * v4l2_print_dv_timings() - log the contents of a dv_timings struct
 * @dev_prefix:device prefix for each log line.
 * @prefix:	additional prefix for each log line, may be NULL.
 * @t:		the timings data.
 * @detailed:	if true, give a detailed log.
 */
void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
			   const struct v4l2_dv_timings *t, bool detailed);

/**
 * v4l2_detect_cvt - detect if the given timings follow the CVT standard
 *
 * @frame_height: the total height of the frame (including blanking) in lines.
 * @hfreq: the horizontal frequency in Hz.
 * @vsync: the height of the vertical sync in lines.
 * @active_width: active width of image (does not include blanking). This
 * information is needed only in case of version 2 of reduced blanking.
 * In other cases, this parameter does not have any effect on timings.
 * @polarities: the horizontal and vertical polarities (same as struct
 *		v4l2_bt_timings polarities).
 * @interlaced: if this flag is true, it indicates interlaced format
 * @fmt: the resulting timings.
 *
 * This function will attempt to detect if the given values correspond to a
 * valid CVT format. If so, then it will return true, and fmt will be filled
 * in with the found CVT timings.
 */
bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
		unsigned active_width, u32 polarities, bool interlaced,
		struct v4l2_dv_timings *fmt);

/**
 * v4l2_detect_gtf - detect if the given timings follow the GTF standard
 *
 * @frame_height: the total height of the frame (including blanking) in lines.
 * @hfreq: the horizontal frequency in Hz.
 * @vsync: the height of the vertical sync in lines.
 * @polarities: the horizontal and vertical polarities (same as struct
 *		v4l2_bt_timings polarities).
 * @interlaced: if this flag is true, it indicates interlaced format
 * @aspect: preferred aspect ratio. GTF has no method of determining the
 *		aspect ratio in order to derive the image width from the
 *		image height, so it has to be passed explicitly. Usually
 *		the native screen aspect ratio is used for this. If it
 *		is not filled in correctly, then 16:9 will be assumed.
 * @fmt: the resulting timings.
 *
 * This function will attempt to detect if the given values correspond to a
 * valid GTF format. If so, then it will return true, and fmt will be filled
 * in with the found GTF timings.
 */
bool v4l2_detect_gtf(unsigned frame_height, unsigned hfreq, unsigned vsync,
		u32 polarities, bool interlaced, struct v4l2_fract aspect,
		struct v4l2_dv_timings *fmt);

/**
 * v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
 *	0x15 and 0x16 from the EDID.
 *
 * @hor_landscape: byte 0x15 from the EDID.
 * @vert_portrait: byte 0x16 from the EDID.
 *
 * Determines the aspect ratio from the EDID.
 * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
 * "Horizontal and Vertical Screen Size or Aspect Ratio"
 */
struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait);

/**
 * v4l2_dv_timings_aspect_ratio - calculate the aspect ratio based on the
 *	v4l2_dv_timings information.
 *
 * @t: the timings data.
 */
struct v4l2_fract v4l2_dv_timings_aspect_ratio(const struct v4l2_dv_timings *t);

/**
 * can_reduce_fps - check if conditions for reduced fps are true.
 * @bt: v4l2 timing structure
 *
 * For different timings reduced fps is allowed if the following conditions
 * are met:
 *
 *   - For CVT timings: if reduced blanking v2 (vsync == 8) is true.
 *   - For CEA861 timings: if %V4L2_DV_FL_CAN_REDUCE_FPS flag is true.
 */
static inline  bool can_reduce_fps(struct v4l2_bt_timings *bt)
{
	if ((bt->standards & V4L2_DV_BT_STD_CVT) && (bt->vsync == 8))
		return true;

	if ((bt->standards & V4L2_DV_BT_STD_CEA861) &&
	    (bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS))
		return true;

	return false;
}


#endif