[media] v4l2-dv-timings: add new helper module

This module makes it easy to filter valid timings from the full list of
CEA and DMT timings based on the timings capabilities.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

1 files changed, 67 insertions, 0 deletions

diff --git a/include/media/v4l2-dv-timings.h b/include/media/v4l2-dv-timings.h
new file mode 100644
index 000000000000..41075fa02a96
--- /dev/null
+++ b/include/media/v4l2-dv-timings.h
@@ -0,0 +1,67 @@
+/*
+ * 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_valid_timings() - are these timings valid?
+  * @t:	  the v4l2_dv_timings struct.
+  * @cap: the v4l2_dv_timings_cap capabilities.
+  *
+  * Returns true if the given dv_timings struct is supported by the
+  * hardware capabilities, returns false otherwise.
+  */
+bool v4l2_dv_valid_timings(const struct v4l2_dv_timings *t,
+			   const struct v4l2_dv_timings_cap *cap);
+
+/** 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.
+  *
+  * 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.
+  *
+  * 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_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.
+  *
+  * 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.
+  *
+  * 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);
+
+#endif