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/drivers/video/videomode.c b/drivers/video/videomode.c
new file mode 100644
index 0000000..21c47a2
--- /dev/null
+++ b/drivers/video/videomode.c
@@ -0,0 +1,39 @@
+/*
+ * generic display timing functions
+ *
+ * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix
+ *
+ * This file is released under the GPLv2
+ */
+
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <video/display_timing.h>
+#include <video/videomode.h>
+
+int videomode_from_timing(const struct display_timings *disp,
+ struct videomode *vm, unsigned int index)
+{
+ struct display_timing *dt;
+
+ dt = display_timings_get(disp, index);
+ if (!dt)
+ return -EINVAL;
+
+ vm->pixelclock = display_timing_get_value(&dt->pixelclock, TE_TYP);
+ vm->hactive = display_timing_get_value(&dt->hactive, TE_TYP);
+ vm->hfront_porch = display_timing_get_value(&dt->hfront_porch, TE_TYP);
+ vm->hback_porch = display_timing_get_value(&dt->hback_porch, TE_TYP);
+ vm->hsync_len = display_timing_get_value(&dt->hsync_len, TE_TYP);
+
+ vm->vactive = display_timing_get_value(&dt->vactive, TE_TYP);
+ vm->vfront_porch = display_timing_get_value(&dt->vfront_porch, TE_TYP);
+ vm->vback_porch = display_timing_get_value(&dt->vback_porch, TE_TYP);
+ vm->vsync_len = display_timing_get_value(&dt->vsync_len, TE_TYP);
+
+ vm->dmt_flags = dt->dmt_flags;
+ vm->data_flags = dt->data_flags;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(videomode_from_timing);