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/*
* Copyright 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>
*
* description of display timings
*
* This file is released under the GPLv2
*/
#ifndef __LINUX_DISPLAY_TIMING_H
#define __LINUX_DISPLAY_TIMING_H
#include <linux/bitops.h>
#include <linux/types.h>
/* VESA display monitor timing parameters */
#define VESA_DMT_HSYNC_LOW BIT(0)
#define VESA_DMT_HSYNC_HIGH BIT(1)
#define VESA_DMT_VSYNC_LOW BIT(2)
#define VESA_DMT_VSYNC_HIGH BIT(3)
/* display specific flags */
#define DISPLAY_FLAGS_DE_LOW BIT(0) /* data enable flag */
#define DISPLAY_FLAGS_DE_HIGH BIT(1)
#define DISPLAY_FLAGS_PIXDATA_POSEDGE BIT(2) /* drive data on pos. edge */
#define DISPLAY_FLAGS_PIXDATA_NEGEDGE BIT(3) /* drive data on neg. edge */
#define DISPLAY_FLAGS_INTERLACED BIT(4)
#define DISPLAY_FLAGS_DOUBLESCAN BIT(5)
/*
* A single signal can be specified via a range of minimal and maximal values
* with a typical value, that lies somewhere inbetween.
*/
struct timing_entry {
u32 min;
u32 typ;
u32 max;
};
enum timing_entry_index {
TE_MIN = 0,
TE_TYP = 1,
TE_MAX = 2,
};
/*
* Single "mode" entry. This describes one set of signal timings a display can
* have in one setting. This struct can later be converted to struct videomode
* (see include/video/videomode.h). As each timing_entry can be defined as a
* range, one struct display_timing may become multiple struct videomodes.
*
* Example: hsync active high, vsync active low
*
* Active Video
* Video ______________________XXXXXXXXXXXXXXXXXXXXXX_____________________
* |<- sync ->|<- back ->|<----- active ----->|<- front ->|<- sync..
* | | porch | | porch |
*
* HSync _|¯¯¯¯¯¯¯¯¯¯|___________________________________________|¯¯¯¯¯¯¯¯¯
*
* VSync ¯|__________|¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯|_________
*/
struct display_timing {
struct timing_entry pixelclock;
struct timing_entry hactive; /* hor. active video */
struct timing_entry hfront_porch; /* hor. front porch */
struct timing_entry hback_porch; /* hor. back porch */
struct timing_entry hsync_len; /* hor. sync len */
struct timing_entry vactive; /* ver. active video */
struct timing_entry vfront_porch; /* ver. front porch */
struct timing_entry vback_porch; /* ver. back porch */
struct timing_entry vsync_len; /* ver. sync len */
unsigned int dmt_flags; /* VESA DMT flags */
unsigned int data_flags; /* video data flags */
};
/*
* This describes all timing settings a display provides.
* The native_mode is the default setting for this display.
* Drivers that can handle multiple videomodes should work with this struct and
* convert each entry to the desired end result.
*/
struct display_timings {
unsigned int num_timings;
unsigned int native_mode;
struct display_timing **timings;
};
/* get value specified by index from struct timing_entry */
static inline u32 display_timing_get_value(const struct timing_entry *te,
enum timing_entry_index index)
{
switch (index) {
case TE_MIN:
return te->min;
break;
case TE_TYP:
return te->typ;
break;
case TE_MAX:
return te->max;
break;
default:
return te->typ;
}
}
/* get one entry from struct display_timings */
static inline struct display_timing *display_timings_get(const struct
display_timings *disp,
unsigned int index)
{
if (disp->num_timings > index)
return disp->timings[index];
else
return NULL;
}
void display_timings_release(struct display_timings *disp);
#endif
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