--- /dev/null
+/*
+ * 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
Code Review / kvmfornfv.git / blobdiff