/*
 * 86Box	A hypervisor and IBM PC system emulator that specializes in
 *		running old operating systems and software designed for IBM
 *		PC systems and compatibles from 1981 through fairly recent
 *		system designs based on the PCI bus.
 *
 *		This file is part of the 86Box distribution.
 *
 *		DDC monitor emulation.
 *
 *
 *
 * Authors:	Sarah Walker, <http://pcem-emulator.co.uk/>
 *		RichardG, <richardg867@gmail.com>
 *
 *		Copyright 2008-2020 Sarah Walker.
 *		Copyright 2020 RichardG.
 */
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <stddef.h>
#include <wchar.h>
#include <math.h>
#include <86box/86box.h>
#include <86box/i2c.h>


static uint8_t edid_data[128] = {
    0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, /* Fixed header pattern */
    0x09, 0xf8, /* Manufacturer "BOX" - apparently unassigned by UEFI - and it has to be big endian */
    0x00, 0x00, /* Product code */
    0x12, 0x34, 0x56, 0x78, /* Serial number */
    47, 30, /* Manufacturer week and year */
    0x01, 0x03, /* EDID version (1.3) */

    0x08, /* Analog input, separate sync */
    34, 0, /* Landscape, 4:3 */
    0, /* Gamma */
    0x08, /* RGB colour */
    0x81, 0xf1, 0xa3, 0x57, 0x53, 0x9f, 0x27, 0x0a, 0x50, /* Chromaticity */

    0xff, 0xff, 0xff, /* Established timing bitmap */
    0x00, 0x00, /* Standard timing information */
    0x00, 0x00,
    0x00, 0x00,
    0x00, 0x00,
    0x00, 0x00,
    0x00, 0x00,
    0x00, 0x00,
    0x00, 0x00,

    /* Detailed mode descriptions */
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

    0x00, /* No extensions */
    0x00
};


void *
ddc_init(void *i2c)
{
    uint8_t checksum = 0;
    for (int c = 0; c < 127; c++)
        checksum += edid_data[c];
    edid_data[127] = 256 - checksum;

    return i2c_eeprom_init(i2c, 0x50, edid_data, sizeof(edid_data), 0);
}


void
ddc_close(void *dev_handle)
{
    i2c_eeprom_close(dev_handle);
}