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linux-sg2042/drivers/video/display_timing.c

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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>
2012-12-17 21:20:17 +08:00
/*
* generic display timing functions
*
* Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix
*
* This file is released under the GPLv2
*/
#include <linux/export.h>
#include <linux/slab.h>
#include <video/display_timing.h>
void display_timings_release(struct display_timings *disp)
{
if (disp->timings) {
unsigned int i;
for (i = 0; i < disp->num_timings; i++)
kfree(disp->timings[i]);
kfree(disp->timings);
}
kfree(disp);
}
EXPORT_SYMBOL_GPL(display_timings_release);