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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include "early_vx900.h"
static void vx900_cpu_bus_preram_setup(void)
{
/* Faster CPU to DRAM Cycle */
pci_mod_config8(HOST_BUS, 0x50, 0x0f, 0x08);
/* CPU Interface Control - Basic Options */
pci_mod_config8(HOST_BUS, 0x51, 0, 0x6c);
/*CPU Interface Control - Advanced Options */
pci_write_config8(HOST_BUS, 0x52, 0xc7);
/* Enable 8QW burst and 4QW request merging [4] and [2]
* and special mode for read cycles bit[3] */
pci_mod_config8(HOST_BUS, 0x54, 0, (1 << 4) | (1 << 2) | (1 << 3));
/* High priority upstream requests on V4 bus */
pci_write_config8(HOST_BUS, 0x56, 0x03);
/* CPU to DRAM extra 1T access control */
pci_mod_config8(HOST_BUS, 0x59, 0x00, (1 << 2));
/* Queue reordering */
pci_mod_config8(HOST_BUS, 0x5f, 0x00, (1 << 6));
/* Only Write cycle of CPU->GFXCTL will flush the CPU->Memory FIFO */
pci_mod_config8(HOST_BUS, 0x98, 0x00, 0x60);
/* 1T delay for data on CPU bus */
pci_write_config8(HOST_BUS, 0x9e, 0x0e);
/* Arbitrate ownership of DRAM controller a few cycles earlier */
pci_mod_config8(HOST_BUS, 0x9f, 0x00, (1 << 7));
/* Write retire policy */
pci_write_config8(HOST_BUS, 0x5d, 0xa2);
/* Occupancy timer */
pci_write_config8(HOST_BUS, 0x53, 0x44);
/* Medium Threshold for Write Retire Policy - 6 requests */
pci_mod_config8(HOST_BUS, 0x56, 0x00, 0x60);
/* Bandwidth timer */
pci_write_config8(HOST_BUS, 0x5e, 0x44);
}
/**
* \brief Configure the CPU to northbridge bus (formerly, FSB)
*
* Configure the CPU <-> host interface. This interface is complex and needs to
* be set up to operate properly. Configured parameters include bandwidth
* arbitration. This function does not, however, change the physical interface
* parameters, such as drive strength and signal timing. Instead, it assumes
* that those parameters were already configured correctly from the ROMSTRAP.
*/
void vx900_cpu_bus_interface_setup(void)
{
vx900_cpu_bus_preram_setup();
dump_pci_device(HOST_BUS);
}