/* * v4l2-dv-timings - Internal header with dv-timings helper functions * * Copyright 2013 Cisco Systems, Inc. and/or its affiliates. All rights reserved. * * This program is free software; you may redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. * */ #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[]; /** * 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_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); /* * reduce_fps - check if conditions for reduced fps are true. * bt - v4l2 timing structure * For different timings reduced fps is allowed if 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