/*
* Copyright 2012 Steffen Trumtrar <[email protected]>
*
* 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>

enum display_flags {
DISPLAY_FLAGS_HSYNC_LOW = BIT(0),
DISPLAY_FLAGS_HSYNC_HIGH = BIT(1),
DISPLAY_FLAGS_VSYNC_LOW = BIT(2),
DISPLAY_FLAGS_VSYNC_HIGH = BIT(3),

/* data enable flag */
DISPLAY_FLAGS_DE_LOW = BIT(4),
DISPLAY_FLAGS_DE_HIGH = BIT(5),
/* drive data on pos. edge */
DISPLAY_FLAGS_PIXDATA_POSEDGE = BIT(6),
/* drive data on neg. edge */
DISPLAY_FLAGS_PIXDATA_NEGEDGE = BIT(7),
DISPLAY_FLAGS_INTERLACED = BIT(8),
DISPLAY_FLAGS_DOUBLESCAN = BIT(9),
DISPLAY_FLAGS_DOUBLECLK = BIT(10),
};

/*
* 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;
};

/*
* 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 */

enum display_flags flags; /* display 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 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