diff options
Diffstat (limited to 'arch/arm/cpu/arm920t/ks8695/lowlevel_init.S')
| -rw-r--r-- | arch/arm/cpu/arm920t/ks8695/lowlevel_init.S | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/arch/arm/cpu/arm920t/ks8695/lowlevel_init.S b/arch/arm/cpu/arm920t/ks8695/lowlevel_init.S new file mode 100644 index 0000000..1bba571 --- /dev/null +++ b/arch/arm/cpu/arm920t/ks8695/lowlevel_init.S @@ -0,0 +1,205 @@ +/* + * 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, #((25000000+CONFIG_BAUDRATE/2) / CONFIG_BAUDRATE) + str r2, [r1] + ldr r1, =(KS8695_IO_BASE+KS8695_UART_LINE_CTRL) + mov r2, #KS8695_UART_LINEC_WLEN8 + 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 */ |
