video: add display_timing and videomode
Add display_timing structure and the according helper functions. This allows
the description of a display via its supported timing parameters.
Also, add helper functions to convert from display timings to a generic videomode
structure.
The struct display_timing specifies all needed parameters to describe the signal
properties of a display in one mode. This includes
- ranges for signals that may have min-, max- and typical values
- single integers for signals that can be on, off or are ignored
- booleans for signals that are either on or off
As a display may support multiple modes like this, a struct display_timings is
added, that holds all given struct display_timing pointers and declares the
native mode of the display.
Although a display may state that a signal can be in a range, it is driven with
fixed values that indicate a videomode. Therefore graphic drivers don't need all
the information of struct display_timing, but would generate a videomode from
the given set of supported signal timings and work with that.
The video subsystems all define their own structs that describe a mode and work
with that (e.g. fb_videomode or drm_display_mode). To slowly replace all those
various structures and allow code reuse across those subsystems, add struct
videomode as a generic description.
This patch only includes the most basic fields in struct videomode. All missing
fields that are needed to have a really generic video mode description can be
added at a later stage.
Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Afzal Mohammed <Afzal@ti.com>
Tested-by: Rob Clark <robclark@gmail.com>
Tested-by: Leela Krishna Amudala <leelakrishna.a@gmail.com>
diff --git a/include/video/videomode.h b/include/video/videomode.h
new file mode 100644
index 0000000..a421562
--- /dev/null
+++ b/include/video/videomode.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>
+ *
+ * generic videomode description
+ *
+ * This file is released under the GPLv2
+ */
+
+#ifndef __LINUX_VIDEOMODE_H
+#define __LINUX_VIDEOMODE_H
+
+#include <linux/types.h>
+#include <video/display_timing.h>
+
+/*
+ * Subsystem independent description of a videomode.
+ * Can be generated from struct display_timing.
+ */
+struct videomode {
+ unsigned long pixelclock; /* pixelclock in Hz */
+
+ u32 hactive;
+ u32 hfront_porch;
+ u32 hback_porch;
+ u32 hsync_len;
+
+ u32 vactive;
+ u32 vfront_porch;
+ u32 vback_porch;
+ u32 vsync_len;
+
+ unsigned int dmt_flags; /* VESA DMT flags */
+ unsigned int data_flags; /* video data flags */
+};
+
+/**
+ * videomode_from_timing - convert display timing to videomode
+ * @disp: structure with all possible timing entries
+ * @vm: return value
+ * @index: index into the list of display timings in devicetree
+ *
+ * DESCRIPTION:
+ * This function converts a struct display_timing to a struct videomode.
+ */
+int videomode_from_timing(const struct display_timings *disp,
+ struct videomode *vm, unsigned int index);
+
+#endif