2 * v4l2-dv-timings - Internal header with dv-timings helper functions
4 * Copyright 2013 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
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8 * the Free Software Foundation; version 2 of the License.
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21 #ifndef __V4L2_DV_TIMINGS_H
22 #define __V4L2_DV_TIMINGS_H
24 #include <linux/videodev2.h>
27 * v4l2_dv_timings_presets: list of all dv_timings presets.
29 extern const struct v4l2_dv_timings v4l2_dv_timings_presets[];
32 * typedef v4l2_check_dv_timings_fnc - timings check callback
34 * @t: the v4l2_dv_timings struct.
35 * @handle: a handle from the driver.
37 * Returns true if the given timings are valid.
39 typedef bool v4l2_check_dv_timings_fnc(const struct v4l2_dv_timings *t, void *handle);
42 * v4l2_valid_dv_timings() - are these timings valid?
44 * @t: the v4l2_dv_timings struct.
45 * @cap: the v4l2_dv_timings_cap capabilities.
46 * @fnc: callback to check if this timing is OK. May be NULL.
47 * @fnc_handle: a handle that is passed on to @fnc.
49 * Returns true if the given dv_timings struct is supported by the
50 * hardware capabilities and the callback function (if non-NULL), returns
53 bool v4l2_valid_dv_timings(const struct v4l2_dv_timings *t,
54 const struct v4l2_dv_timings_cap *cap,
55 v4l2_check_dv_timings_fnc fnc,
59 * v4l2_enum_dv_timings_cap() - Helper function to enumerate possible DV
60 * timings based on capabilities
62 * @t: the v4l2_enum_dv_timings struct.
63 * @cap: the v4l2_dv_timings_cap capabilities.
64 * @fnc: callback to check if this timing is OK. May be NULL.
65 * @fnc_handle: a handle that is passed on to @fnc.
67 * This enumerates dv_timings using the full list of possible CEA-861 and DMT
68 * timings, filtering out any timings that are not supported based on the
69 * hardware capabilities and the callback function (if non-NULL).
71 * If a valid timing for the given index is found, it will fill in @t and
72 * return 0, otherwise it returns -EINVAL.
74 int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
75 const struct v4l2_dv_timings_cap *cap,
76 v4l2_check_dv_timings_fnc fnc,
80 * v4l2_find_dv_timings_cap() - Find the closest timings struct
82 * @t: the v4l2_enum_dv_timings struct.
83 * @cap: the v4l2_dv_timings_cap capabilities.
84 * @pclock_delta: maximum delta between t->pixelclock and the timing struct
85 * under consideration.
86 * @fnc: callback to check if a given timings struct is OK. May be NULL.
87 * @fnc_handle: a handle that is passed on to @fnc.
89 * This function tries to map the given timings to an entry in the
90 * full list of possible CEA-861 and DMT timings, filtering out any timings
91 * that are not supported based on the hardware capabilities and the callback
92 * function (if non-NULL).
94 * On success it will fill in @t with the found timings and it returns true.
95 * On failure it will return false.
97 bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
98 const struct v4l2_dv_timings_cap *cap,
99 unsigned pclock_delta,
100 v4l2_check_dv_timings_fnc fnc,
104 * v4l2_find_dv_timings_cea861_vic() - find timings based on CEA-861 VIC
105 * @t: the timings data.
106 * @vic: CEA-861 VIC code
108 * On success it will fill in @t with the found timings and it returns true.
109 * On failure it will return false.
111 bool v4l2_find_dv_timings_cea861_vic(struct v4l2_dv_timings *t, u8 vic);
114 * v4l2_match_dv_timings() - do two timings match?
116 * @measured: the measured timings data.
117 * @standard: the timings according to the standard.
118 * @pclock_delta: maximum delta in Hz between standard->pixelclock and
119 * the measured timings.
120 * @match_reduced_fps: if true, then fail if V4L2_DV_FL_REDUCED_FPS does not
123 * Returns true if the two timings match, returns false otherwise.
125 bool v4l2_match_dv_timings(const struct v4l2_dv_timings *measured,
126 const struct v4l2_dv_timings *standard,
127 unsigned pclock_delta, bool match_reduced_fps);
130 * v4l2_print_dv_timings() - log the contents of a dv_timings struct
131 * @dev_prefix:device prefix for each log line.
132 * @prefix: additional prefix for each log line, may be NULL.
133 * @t: the timings data.
134 * @detailed: if true, give a detailed log.
136 void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
137 const struct v4l2_dv_timings *t, bool detailed);
140 * v4l2_detect_cvt - detect if the given timings follow the CVT standard
142 * @frame_height: the total height of the frame (including blanking) in lines.
143 * @hfreq: the horizontal frequency in Hz.
144 * @vsync: the height of the vertical sync in lines.
145 * @active_width: active width of image (does not include blanking). This
146 * information is needed only in case of version 2 of reduced blanking.
147 * In other cases, this parameter does not have any effect on timings.
148 * @polarities: the horizontal and vertical polarities (same as struct
149 * v4l2_bt_timings polarities).
150 * @interlaced: if this flag is true, it indicates interlaced format
151 * @fmt: the resulting timings.
153 * This function will attempt to detect if the given values correspond to a
154 * valid CVT format. If so, then it will return true, and fmt will be filled
155 * in with the found CVT timings.
157 bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
158 unsigned active_width, u32 polarities, bool interlaced,
159 struct v4l2_dv_timings *fmt);
162 * v4l2_detect_gtf - detect if the given timings follow the GTF standard
164 * @frame_height: the total height of the frame (including blanking) in lines.
165 * @hfreq: the horizontal frequency in Hz.
166 * @vsync: the height of the vertical sync in lines.
167 * @polarities: the horizontal and vertical polarities (same as struct
168 * v4l2_bt_timings polarities).
169 * @interlaced: if this flag is true, it indicates interlaced format
170 * @aspect: preferred aspect ratio. GTF has no method of determining the
171 * aspect ratio in order to derive the image width from the
172 * image height, so it has to be passed explicitly. Usually
173 * the native screen aspect ratio is used for this. If it
174 * is not filled in correctly, then 16:9 will be assumed.
175 * @fmt: the resulting timings.
177 * This function will attempt to detect if the given values correspond to a
178 * valid GTF format. If so, then it will return true, and fmt will be filled
179 * in with the found GTF timings.
181 bool v4l2_detect_gtf(unsigned frame_height, unsigned hfreq, unsigned vsync,
182 u32 polarities, bool interlaced, struct v4l2_fract aspect,
183 struct v4l2_dv_timings *fmt);
186 * v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
187 * 0x15 and 0x16 from the EDID.
189 * @hor_landscape: byte 0x15 from the EDID.
190 * @vert_portrait: byte 0x16 from the EDID.
192 * Determines the aspect ratio from the EDID.
193 * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
194 * "Horizontal and Vertical Screen Size or Aspect Ratio"
196 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait);
199 * v4l2_dv_timings_aspect_ratio - calculate the aspect ratio based on the
200 * v4l2_dv_timings information.
202 * @t: the timings data.
204 struct v4l2_fract v4l2_dv_timings_aspect_ratio(const struct v4l2_dv_timings *t);
207 * reduce_fps - check if conditions for reduced fps are true.
208 * bt - v4l2 timing structure
209 * For different timings reduced fps is allowed if following conditions
211 * For CVT timings: if reduced blanking v2 (vsync == 8) is true.
212 * For CEA861 timings: if V4L2_DV_FL_CAN_REDUCE_FPS flag is true.
214 static inline bool can_reduce_fps(struct v4l2_bt_timings *bt)
216 if ((bt->standards & V4L2_DV_BT_STD_CVT) && (bt->vsync == 8))
219 if ((bt->standards & V4L2_DV_BT_STD_CEA861) &&
220 (bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS))