linux/arch/powerpc/boot/ebony.c

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/*
* Copyright 2007 David Gibson, IBM Corporation.
*
* Based on earlier code:
* Copyright (C) Paul Mackerras 1997.
*
* Matt Porter <mporter@kernel.crashing.org>
* Copyright 2002-2005 MontaVista Software Inc.
*
* Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
* Copyright (c) 2003, 2004 Zultys Technologies
*
* 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.
*/
#include <stdarg.h>
#include <stddef.h>
#include "types.h"
#include "elf.h"
#include "string.h"
#include "stdio.h"
#include "page.h"
#include "ops.h"
#include "reg.h"
#include "dcr.h"
#include "44x.h"
extern char _dtb_start[];
extern char _dtb_end[];
static u8 *ebony_mac0, *ebony_mac1;
/* Calculate 440GP clocks */
void ibm440gp_fixup_clocks(unsigned int sysclk, unsigned int ser_clk)
{
u32 sys0 = mfdcr(DCRN_CPC0_SYS0);
u32 cr0 = mfdcr(DCRN_CPC0_CR0);
u32 cpu, plb, opb, ebc, tb, uart0, uart1, m;
u32 opdv = CPC0_SYS0_OPDV(sys0);
u32 epdv = CPC0_SYS0_EPDV(sys0);
if (sys0 & CPC0_SYS0_BYPASS) {
/* Bypass system PLL */
cpu = plb = sysclk;
} else {
if (sys0 & CPC0_SYS0_EXTSL)
/* PerClk */
m = CPC0_SYS0_FWDVB(sys0) * opdv * epdv;
else
/* CPU clock */
m = CPC0_SYS0_FBDV(sys0) * CPC0_SYS0_FWDVA(sys0);
cpu = sysclk * m / CPC0_SYS0_FWDVA(sys0);
plb = sysclk * m / CPC0_SYS0_FWDVB(sys0);
}
opb = plb / opdv;
ebc = opb / epdv;
/* FIXME: Check if this is for all 440GP, or just Ebony */
if ((mfpvr() & 0xf0000fff) == 0x40000440)
/* Rev. B 440GP, use external system clock */
tb = sysclk;
else
/* Rev. C 440GP, errata force us to use internal clock */
tb = cpu;
if (cr0 & CPC0_CR0_U0EC)
/* External UART clock */
uart0 = ser_clk;
else
/* Internal UART clock */
uart0 = plb / CPC0_CR0_UDIV(cr0);
if (cr0 & CPC0_CR0_U1EC)
/* External UART clock */
uart1 = ser_clk;
else
/* Internal UART clock */
uart1 = plb / CPC0_CR0_UDIV(cr0);
printf("PPC440GP: SysClk = %dMHz (%x)\n\r",
(sysclk + 500000) / 1000000, sysclk);
dt_fixup_cpu_clocks(cpu, tb, 0);
dt_fixup_clock("/plb", plb);
dt_fixup_clock("/plb/opb", opb);
dt_fixup_clock("/plb/opb/ebc", ebc);
dt_fixup_clock("/plb/opb/serial@40000200", uart0);
dt_fixup_clock("/plb/opb/serial@40000300", uart1);
}
static void ebony_fixups(void)
{
// FIXME: sysclk should be derived by reading the FPGA registers
unsigned long sysclk = 33000000;
ibm440gp_fixup_clocks(sysclk, 6 * 1843200);
ibm44x_fixup_memsize();
dt_fixup_mac_addresses(ebony_mac0, ebony_mac1);
ibm4xx_fixup_ebc_ranges("/plb/opb/ebc");
}
void ebony_init(void *mac0, void *mac1)
{
platform_ops.fixups = ebony_fixups;
platform_ops.exit = ibm44x_dbcr_reset;
ebony_mac0 = mac0;
ebony_mac1 = mac1;
ft_init(_dtb_start, _dtb_end - _dtb_start, 32);
serial_console_init();
}