/*
        Haiku S3 Virge driver adapted from the X.org Virge and Savage driver.

        Copyright (C) 1994-2000 The XFree86 Project, Inc.  All Rights Reserved.

        Copyright 2007-2008 Haiku, Inc.  All rights reserved.
        Distributed under the terms of the MIT license.

        Authors:
        Gerald Zajac 2007-2008
*/

#include "accel.h"
#include "virge.h"

#include <string.h>
#include <ddc.h>
#include <edid.h>



static status_t
GetI2CSignals_Alt(void* cookie, int* _clock, int* data)
{
        uint32 index = (uint32)(addr_t)cookie;
        uint8 value = ReadCrtcReg(index);

        *_clock = (value & 0x4) != 0;
        *data = (value & 0x8) != 0;
        return B_OK;
}


static status_t
SetI2CSignals_Alt(void* cookie, int _clock, int data)
{
        uint32 index = (uint32)(addr_t)cookie;
        uint8 value = 0x10;

        if (_clock)
                value |= 0x1;
        if (data)
                value |= 0x2;

        WriteCrtcReg(index, value);
        return B_OK;
}



static status_t
GetI2CSignals(void* cookie, int* _clock, int* data)
{
        (void)cookie;           // avoid compiler warning for unused arg

        uint8 reg = ReadReg8(DDC_REG);

        *_clock = (reg & 0x4) != 0;
        *data = (reg & 0x8) != 0;
        return B_OK;
}


static status_t
SetI2CSignals(void* cookie, int _clock, int data)
{
        (void)cookie;           // avoid compiler warning for unused arg

        uint8 reg = 0x10;

        if (_clock)
                reg |= 0x1;
        if (data)
                reg |= 0x2;

        WriteReg8(DDC_REG, reg);
        return B_OK;
}



bool
Virge_GetEdidInfo(edid1_info& edidInfo)
{
        // Get the EDID info and return true if successful.

        SharedInfo& si = *gInfo.sharedInfo;

        bool bResult = false;

        if (si.chipType == S3_TRIO_3D_2X) {
                uint32 DDCPort = 0xAA;

                i2c_bus bus;
                bus.cookie = (void*)(addr_t)DDCPort;
                bus.set_signals = &SetI2CSignals_Alt;
                bus.get_signals = &GetI2CSignals_Alt;
                ddc2_init_timing(&bus);

                uint8 tmp = ReadCrtcReg(DDCPort);
                WriteCrtcReg(DDCPort, tmp | 0x13);

                bResult = (ddc2_read_edid1(&bus, &edidInfo, NULL, NULL) == B_OK);

                WriteCrtcReg(DDCPort, tmp);
        } else {
                i2c_bus bus;
                bus.cookie = (void*)DDC_REG;
                bus.set_signals = &SetI2CSignals;
                bus.get_signals = &GetI2CSignals;
                ddc2_init_timing(&bus);

                uint8 tmp = ReadReg8(DDC_REG);
                WriteReg8(DDC_REG, tmp | 0x13);

                bResult = (ddc2_read_edid1(&bus, &edidInfo, NULL, NULL) == B_OK);

                WriteReg8(DDC_REG, tmp);
        }

        return bResult;
}