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 */ 28 extern 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 */ 36 typedef 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 */ 48 bool 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 */ 66 int 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 */ 87 bool 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 */ 101 bool 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 */ 111 void 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 * @interlaced - if this flag is true, it indicates interlaced format 121 * @fmt - the resulting timings. 122 * 123 * This function will attempt to detect if the given values correspond to a 124 * valid CVT format. If so, then it will return true, and fmt will be filled 125 * in with the found CVT timings. 126 */ 127 bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync, 128 u32 polarities, bool interlaced, struct v4l2_dv_timings *fmt); 129 130 /** v4l2_detect_gtf - detect if the given timings follow the GTF standard 131 * @frame_height - the total height of the frame (including blanking) in lines. 132 * @hfreq - the horizontal frequency in Hz. 133 * @vsync - the height of the vertical sync in lines. 134 * @polarities - the horizontal and vertical polarities (same as struct 135 * v4l2_bt_timings polarities). 136 * @interlaced - if this flag is true, it indicates interlaced format 137 * @aspect - preferred aspect ratio. GTF has no method of determining the 138 * aspect ratio in order to derive the image width from the 139 * image height, so it has to be passed explicitly. Usually 140 * the native screen aspect ratio is used for this. If it 141 * is not filled in correctly, then 16:9 will be assumed. 142 * @fmt - the resulting timings. 143 * 144 * This function will attempt to detect if the given values correspond to a 145 * valid GTF format. If so, then it will return true, and fmt will be filled 146 * in with the found GTF timings. 147 */ 148 bool v4l2_detect_gtf(unsigned frame_height, unsigned hfreq, unsigned vsync, 149 u32 polarities, bool interlaced, struct v4l2_fract aspect, 150 struct v4l2_dv_timings *fmt); 151 152 /** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes 153 * 0x15 and 0x16 from the EDID. 154 * @hor_landscape - byte 0x15 from the EDID. 155 * @vert_portrait - byte 0x16 from the EDID. 156 * 157 * Determines the aspect ratio from the EDID. 158 * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2: 159 * "Horizontal and Vertical Screen Size or Aspect Ratio" 160 */ 161 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait); 162 163 #endif 164