include/media/v4l2-dv-timings.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * v4l2-dv-timings - Internal header with dv-timings helper functions
   4  *
   5  * Copyright 2013 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
   6  */
   7
   8 #ifndef __V4L2_DV_TIMINGS_H
   9 #define __V4L2_DV_TIMINGS_H
  10
  11 #include <linux/videodev2.h>
  12
  13 /*
  14  * v4l2_dv_timings_presets: list of all dv_timings presets.
  15  */
  16 extern const struct v4l2_dv_timings v4l2_dv_timings_presets[];
  17
  18 /**
  19  * typedef v4l2_check_dv_timings_fnc - timings check callback
  20  *
  21  * @t: the v4l2_dv_timings struct.
  22  * @handle: a handle from the driver.
  23  *
  24  * Returns true if the given timings are valid.
  25  */
  26 typedef bool v4l2_check_dv_timings_fnc(const struct v4l2_dv_timings *t, void *handle);
  27
  28 /**
  29  * v4l2_valid_dv_timings() - are these timings valid?
  30  *
  31  * @t:    the v4l2_dv_timings struct.
  32  * @cap: the v4l2_dv_timings_cap capabilities.
  33  * @fnc: callback to check if this timing is OK. May be NULL.
  34  * @fnc_handle: a handle that is passed on to @fnc.
  35  *
  36  * Returns true if the given dv_timings struct is supported by the
  37  * hardware capabilities and the callback function (if non-NULL), returns
  38  * false otherwise.
  39  */
  40 bool v4l2_valid_dv_timings(const struct v4l2_dv_timings *t,
  41                            const struct v4l2_dv_timings_cap *cap,
  42                            v4l2_check_dv_timings_fnc fnc,
  43                            void *fnc_handle);
  44
  45 /**
  46  * v4l2_enum_dv_timings_cap() - Helper function to enumerate possible DV
  47  *       timings based on capabilities
  48  *
  49  * @t:    the v4l2_enum_dv_timings struct.
  50  * @cap: the v4l2_dv_timings_cap capabilities.
  51  * @fnc: callback to check if this timing is OK. May be NULL.
  52  * @fnc_handle: a handle that is passed on to @fnc.
  53  *
  54  * This enumerates dv_timings using the full list of possible CEA-861 and DMT
  55  * timings, filtering out any timings that are not supported based on the
  56  * hardware capabilities and the callback function (if non-NULL).
  57  *
  58  * If a valid timing for the given index is found, it will fill in @t and
  59  * return 0, otherwise it returns -EINVAL.
  60  */
  61 int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
  62                              const struct v4l2_dv_timings_cap *cap,
  63                              v4l2_check_dv_timings_fnc fnc,
  64                              void *fnc_handle);
  65
  66 /**
  67  * v4l2_find_dv_timings_cap() - Find the closest timings struct
  68  *
  69  * @t:    the v4l2_enum_dv_timings struct.
  70  * @cap: the v4l2_dv_timings_cap capabilities.
  71  * @pclock_delta: maximum delta between t->pixelclock and the timing struct
  72  *              under consideration.
  73  * @fnc: callback to check if a given timings struct is OK. May be NULL.
  74  * @fnc_handle: a handle that is passed on to @fnc.
  75  *
  76  * This function tries to map the given timings to an entry in the
  77  * full list of possible CEA-861 and DMT timings, filtering out any timings
  78  * that are not supported based on the hardware capabilities and the callback
  79  * function (if non-NULL).
  80  *
  81  * On success it will fill in @t with the found timings and it returns true.
  82  * On failure it will return false.
  83  */
  84 bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
  85                               const struct v4l2_dv_timings_cap *cap,
  86                               unsigned pclock_delta,
  87                               v4l2_check_dv_timings_fnc fnc,
  88                               void *fnc_handle);
  89
  90 /**
  91  * v4l2_find_dv_timings_cea861_vic() - find timings based on CEA-861 VIC
  92  * @t:          the timings data.
  93  * @vic:        CEA-861 VIC code
  94  *
  95  * On success it will fill in @t with the found timings and it returns true.
  96  * On failure it will return false.
  97  */
  98 bool v4l2_find_dv_timings_cea861_vic(struct v4l2_dv_timings *t, u8 vic);
  99
 100 /**
 101  * v4l2_match_dv_timings() - do two timings match?
 102  *
 103  * @measured:     the measured timings data.
 104  * @standard:     the timings according to the standard.
 105  * @pclock_delta: maximum delta in Hz between standard->pixelclock and
 106  *              the measured timings.
 107  * @match_reduced_fps: if true, then fail if V4L2_DV_FL_REDUCED_FPS does not
 108  * match.
 109  *
 110  * Returns true if the two timings match, returns false otherwise.
 111  */
 112 bool v4l2_match_dv_timings(const struct v4l2_dv_timings *measured,
 113                            const struct v4l2_dv_timings *standard,
 114                            unsigned pclock_delta, bool match_reduced_fps);
 115
 116 /**
 117  * v4l2_print_dv_timings() - log the contents of a dv_timings struct
 118  * @dev_prefix:device prefix for each log line.
 119  * @prefix:     additional prefix for each log line, may be NULL.
 120  * @t:          the timings data.
 121  * @detailed:   if true, give a detailed log.
 122  */
 123 void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
 124                            const struct v4l2_dv_timings *t, bool detailed);
 125
 126 /**
 127  * v4l2_detect_cvt - detect if the given timings follow the CVT standard
 128  *
 129  * @frame_height: the total height of the frame (including blanking) in lines.
 130  * @hfreq: the horizontal frequency in Hz.
 131  * @vsync: the height of the vertical sync in lines.
 132  * @active_width: active width of image (does not include blanking). This
 133  * information is needed only in case of version 2 of reduced blanking.
 134  * In other cases, this parameter does not have any effect on timings.
 135  * @polarities: the horizontal and vertical polarities (same as struct
 136  *              v4l2_bt_timings polarities).
 137  * @interlaced: if this flag is true, it indicates interlaced format
 138  * @fmt: the resulting timings.
 139  *
 140  * This function will attempt to detect if the given values correspond to a
 141  * valid CVT format. If so, then it will return true, and fmt will be filled
 142  * in with the found CVT timings.
 143  */
 144 bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
 145                 unsigned active_width, u32 polarities, bool interlaced,
 146                 struct v4l2_dv_timings *fmt);
 147
 148 /**
 149  * v4l2_detect_gtf - detect if the given timings follow the GTF standard
 150  *
 151  * @frame_height: the total height of the frame (including blanking) in lines.
 152  * @hfreq: the horizontal frequency in Hz.
 153  * @vsync: the height of the vertical sync in lines.
 154  * @polarities: the horizontal and vertical polarities (same as struct
 155  *              v4l2_bt_timings polarities).
 156  * @interlaced: if this flag is true, it indicates interlaced format
 157  * @aspect: preferred aspect ratio. GTF has no method of determining the
 158  *              aspect ratio in order to derive the image width from the
 159  *              image height, so it has to be passed explicitly. Usually
 160  *              the native screen aspect ratio is used for this. If it
 161  *              is not filled in correctly, then 16:9 will be assumed.
 162  * @fmt: the resulting timings.
 163  *
 164  * This function will attempt to detect if the given values correspond to a
 165  * valid GTF format. If so, then it will return true, and fmt will be filled
 166  * in with the found GTF timings.
 167  */
 168 bool v4l2_detect_gtf(unsigned frame_height, unsigned hfreq, unsigned vsync,
 169                 u32 polarities, bool interlaced, struct v4l2_fract aspect,
 170                 struct v4l2_dv_timings *fmt);
 171
 172 /**
 173  * v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
 174  *      0x15 and 0x16 from the EDID.
 175  *
 176  * @hor_landscape: byte 0x15 from the EDID.
 177  * @vert_portrait: byte 0x16 from the EDID.
 178  *
 179  * Determines the aspect ratio from the EDID.
 180  * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
 181  * "Horizontal and Vertical Screen Size or Aspect Ratio"
 182  */
 183 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait);
 184
 185 /**
 186  * v4l2_dv_timings_aspect_ratio - calculate the aspect ratio based on the
 187  *      v4l2_dv_timings information.
 188  *
 189  * @t: the timings data.
 190  */
 191 struct v4l2_fract v4l2_dv_timings_aspect_ratio(const struct v4l2_dv_timings *t);
 192
 193 /**
 194  * can_reduce_fps - check if conditions for reduced fps are true.
 195  * @bt: v4l2 timing structure
 196  *
 197  * For different timings reduced fps is allowed if the following conditions
 198  * are met:
 199  *
 200  *   - For CVT timings: if reduced blanking v2 (vsync == 8) is true.
 201  *   - For CEA861 timings: if %V4L2_DV_FL_CAN_REDUCE_FPS flag is true.
 202  */
 203 static inline  bool can_reduce_fps(struct v4l2_bt_timings *bt)
 204 {
 205         if ((bt->standards & V4L2_DV_BT_STD_CVT) && (bt->vsync == 8))
 206                 return true;
 207
 208         if ((bt->standards & V4L2_DV_BT_STD_CEA861) &&
 209             (bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS))
 210                 return true;
 211
 212         return false;
 213 }
 214
 215 /**
 216  * struct v4l2_hdmi_rx_colorimetry - describes the HDMI colorimetry information
 217  * @colorspace:         enum v4l2_colorspace, the colorspace
 218  * @ycbcr_enc:          enum v4l2_ycbcr_encoding, Y'CbCr encoding
 219  * @quantization:       enum v4l2_quantization, colorspace quantization
 220  * @xfer_func:          enum v4l2_xfer_func, colorspace transfer function
 221  */
 222 struct v4l2_hdmi_colorimetry {
 223         enum v4l2_colorspace colorspace;
 224         enum v4l2_ycbcr_encoding ycbcr_enc;
 225         enum v4l2_quantization quantization;
 226         enum v4l2_xfer_func xfer_func;
 227 };
 228
 229 struct hdmi_avi_infoframe;
 230 struct hdmi_vendor_infoframe;
 231
 232 struct v4l2_hdmi_colorimetry
 233 v4l2_hdmi_rx_colorimetry(const struct hdmi_avi_infoframe *avi,
 234                          const struct hdmi_vendor_infoframe *hdmi,
 235                          unsigned int height);
 236
 237 #endif