u-boot/cpu/arm920t/ks8695/lowlevel_init.S
wdenk 3a574cbe72 * Patch by Greg Ungerer, 19 May 2005:
add support for the KS8695P (ARM 922 based) CPU

* Patch by Steven Scholz, 19 May 2005:
  Add support for CONFIG_SERIAL_TAG on ARM boards
2005-05-19 22:39:42 +00:00

205 lines
5.8 KiB
ArmAsm

/*
* lowlevel_init.S - basic hardware initialization for the KS8695 CPU
*
* Copyright (c) 2004-2005, Greg Ungerer <greg.ungerer@opengear.com>
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <config.h>
#include <version.h>
#include <asm/arch/platform.h>
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
/*
*************************************************************************
*
* Handy dandy macros
*
*************************************************************************
*/
/* Delay a bit */
.macro DELAY_FOR cycles, reg0
ldr \reg0, =\cycles
subs \reg0, \reg0, #1
subne pc, pc, #0xc
.endm
/*
*************************************************************************
*
* Some local storage.
*
*************************************************************************
*/
/* Should we boot with an interactive console or not */
.globl serial_console
/*
*************************************************************************
*
* Raw hardware initialization code. The important thing is to get
* SDRAM setup and running. We do some other basic things here too,
* like getting the PLL set for high speed, and init the LEDs.
*
*************************************************************************
*/
.globl lowlevel_init
lowlevel_init:
#if DEBUG
/*
* enable UART for early debug trace
*/
ldr r1, =(KS8695_IO_BASE+KS8695_UART_DIVISOR)
mov r2, #0xd9
str r2, [r1] /* 115200 baud */
ldr r1, =(KS8695_IO_BASE+KS8695_UART_LINE_CTRL)
mov r2, #0x03
str r2, [r1] /* 8 data bits, no parity, 1 stop */
ldr r1, =(KS8695_IO_BASE+KS8695_UART_TX_HOLDING)
mov r2, #0x41
str r2, [r1] /* write 'A' */
#endif
#if DEBUG
ldr r1, =(KS8695_IO_BASE+KS8695_UART_TX_HOLDING)
mov r2, #0x42
str r2, [r1]
#endif
/*
* remap the memory and flash regions. we want to end up with
* ram from address 0, and flash at 32MB.
*/
ldr r1, =(KS8695_IO_BASE+KS8695_MEM_CTRL0)
ldr r2, =0xbfc00040
str r2, [r1] /* large flash map */
ldr pc, =(highflash+0x02000000-0x00f00000) /* jump to high flash address */
highflash:
ldr r2, =0x8fe00040
str r2, [r1] /* remap flash range */
/*
* remap the second select region to the 4MB immediately after
* the first region. This way if you have a larger flash (say 8Mb)
* then you can have it all mapped nicely. Has no effect if you
* only have a 4Mb or smaller flash.
*/
ldr r1, =(KS8695_IO_BASE+KS8695_MEM_CTRL1)
ldr r2, =0x9fe40040
str r2, [r1] /* remap flash2 region, contiguous */
ldr r1, =(KS8695_IO_BASE+KS8695_MEM_GENERAL)
ldr r2, =0x30000005
str r2, [r1] /* enable both flash selects */
#ifdef CONFIG_CM41xx
/*
* map the second flash chip, using the external IO lines.
*/
ldr r1, =(KS8695_IO_BASE+KS8695_IO_CTRL0)
ldr r2, =0xafe80b6d
str r2, [r1] /* remap io0 region, contiguous */
ldr r1, =(KS8695_IO_BASE+KS8695_IO_CTRL1)
ldr r2, =0xbfec0b6d
str r2, [r1] /* remap io1 region, contiguous */
ldr r1, =(KS8695_IO_BASE+KS8695_MEM_GENERAL)
ldr r2, =0x30050005
str r2, [r1] /* enable second flash */
#endif
/*
* before relocating, we have to setup RAM timing
*/
ldr r1, =(KS8695_IO_BASE+KS8695_SDRAM_CTRL0)
#if (PHYS_SDRAM_1_SIZE == 0x02000000)
ldr r2, =0x7fc0000e /* 32MB */
#else
ldr r2, =0x3fc0000e /* 16MB */
#endif
str r2, [r1] /* configure sdram bank0 setup */
ldr r1, =(KS8695_IO_BASE+KS8695_SDRAM_CTRL1)
mov r2, #0
str r2, [r1] /* configure sdram bank1 setup */
ldr r1, =(KS8695_IO_BASE+KS8695_SDRAM_GENERAL)
ldr r2, =0x0000000a
str r2, [r1] /* set RAS/CAS timing */
ldr r1, =(KS8695_IO_BASE+KS8695_SDRAM_BUFFER)
ldr r2, =0x00030000
str r2, [r1] /* send NOP command */
DELAY_FOR 0x100, r0
ldr r2, =0x00010000
str r2, [r1] /* send PRECHARGE-ALL */
DELAY_FOR 0x100, r0
ldr r1, =(KS8695_IO_BASE+KS8695_SDRAM_REFRESH)
ldr r2, =0x00000020
str r2, [r1] /* set for fast refresh */
DELAY_FOR 0x100, r0
ldr r2, =0x00000190
str r2, [r1] /* set normal refresh timing */
ldr r1, =(KS8695_IO_BASE+KS8695_SDRAM_BUFFER)
ldr r2, =0x00020033
str r2, [r1] /* send mode command */
DELAY_FOR 0x100, r0
ldr r2, =0x01f00000
str r2, [r1] /* enable sdram fifos */
/*
* set pll to top speed
*/
ldr r1, =(KS8695_IO_BASE+KS8695_SYSTEN_BUS_CLOCK)
mov r2, #0
str r2, [r1] /* set pll clock to 166MHz */
ldr r1, =(KS8695_IO_BASE+KS8695_SWITCH_CTRL0)
ldr r2, [r1] /* Get switch ctrl0 register */
and r2, r2, #0x0fc00000 /* Mask out LED control bits */
orr r2, r2, #0x01800000 /* Set Link/activity/speed actions */
str r2, [r1]
#ifdef CONFIG_CM4008
ldr r1, =(KS8695_IO_BASE+KS8695_GPIO_MODE)
ldr r2, =0x0000fe30
str r2, [r1] /* enable LED's as outputs */
ldr r1, =(KS8695_IO_BASE+KS8695_GPIO_DATA)
ldr r2, =0x0000fe20
str r2, [r1] /* turn on power LED */
#endif
#if defined(CONFIG_CM4008) || defined(CONFIG_CM41xx)
ldr r2, [r1] /* get current GPIO input data */
tst r2, #0x8 /* check if "erase" depressed */
beq nobutton
mov r2, #0 /* be quiet on boot, no console */
ldr r1, =serial_console
str r2, [r1]
nobutton:
#endif
add lr, lr, #0x02000000 /* flash is now mapped high */
add ip, ip, #0x02000000 /* this is a hack */
mov pc, lr /* all done, return */
#endif /* CONFIG_SKIP_LOWLEVEL_INIT */