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Diffstat (limited to 'kernel/include/media/v4l2-dv-timings.h')
| -rw-r--r-- | kernel/include/media/v4l2-dv-timings.h | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/kernel/include/media/v4l2-dv-timings.h b/kernel/include/media/v4l2-dv-timings.h new file mode 100644 index 000000000..4becc6716 --- /dev/null +++ b/kernel/include/media/v4l2-dv-timings.h @@ -0,0 +1,161 @@ +/* + * 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. + * + * 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); + +/** 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. + * @polarities - the horizontal and vertical polarities (same as struct + * v4l2_bt_timings polarities). + * @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, + u32 polarities, 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). + * @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, 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); + +#endif |