root/include/video/display_timing.h

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INCLUDED FROM


DEFINITIONS

This source file includes following definitions.
  1. display_timings_get

/*
 * 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>

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

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