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Diffstat (limited to 'cpu/at91rm9200/cpu.c')
| -rw-r--r-- | cpu/at91rm9200/cpu.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/cpu/at91rm9200/cpu.c b/cpu/at91rm9200/cpu.c new file mode 100644 index 0000000..f41210b --- /dev/null +++ b/cpu/at91rm9200/cpu.c @@ -0,0 +1,177 @@ +/* + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Marius Groeger <mgroeger@sysgo.de> + * + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Alex Zuepke <azu@sysgo.de> + * + * 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 + */ + +/* + * CPU specific code + */ + +#include <common.h> +#include <command.h> +#include <AT91RM9200.h> + +/* read co-processor 15, register #1 (control register) */ +static unsigned long read_p15_c1(void) +{ + unsigned long value; + + __asm__ __volatile__( + "mrc p15, 0, %0, c1, c0, 0 @ read control reg\n" + : "=r" (value) + : + : "memory"); + /*printf("p15/c1 is = %08lx\n", value); */ + return value; +} + +/* write to co-processor 15, register #1 (control register) */ +static void write_p15_c1(unsigned long value) +{ + /*printf("write %08lx to p15/c1\n", value); */ + __asm__ __volatile__( + "mcr p15, 0, %0, c1, c0, 0 @ write it back\n" + : "=r" (value) + : + : "memory"); + + read_p15_c1(); +} + +static void cp_delay(void) +{ + volatile int i; + + /* copro seems to need some delay between reading and writing */ + for (i=0; i<100; i++); +} +/* See also ARM Ref. Man. */ +#define C1_MMU (1<<0) /* mmu off/on */ +#define C1_ALIGN (1<<1) /* alignment faults off/on */ +#define C1_IDC (1<<2) /* icache and/or dcache off/on */ +#define C1_WRITE_BUFFER (1<<3) /* write buffer off/on */ +#define C1_BIG_ENDIAN (1<<7) /* big endian off/on */ +#define C1_SYS_PROT (1<<8) /* system protection */ +#define C1_ROM_PROT (1<<9) /* ROM protection */ +#define C1_HIGH_VECTORS (1<<13) /* location of vectors: low/high addresses */ + +int cpu_init(void) +{ + /* + * setup up stack if necessary + */ +#ifdef CONFIG_USE_IRQ + IRQ_STACK_START = _armboot_end + + CONFIG_STACKSIZE + CONFIG_STACKSIZE_IRQ - 4; + FIQ_STACK_START = IRQ_STACK_START + CONFIG_STACKSIZE_FIQ; + _armboot_real_end = FIQ_STACK_START + 4; +#else + _armboot_real_end = _armboot_end + CONFIG_STACKSIZE; +#endif + return 0; +} + +int cleanup_before_linux(void) +{ + /* + * this function is called just before we call linux + * it prepares the processor for linux + * + * we turn off caches etc ... + * and we set the CPU-speed to 73 MHz - see start.S for details + */ + + disable_interrupts(); + return 0; +} + +int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +{ + +#ifdef CFG_SOFT_RESET + extern void reset_cpu(ulong addr); + + disable_interrupts(); + reset_cpu(0); +#else + AT91PS_USART us = AT91C_BASE_US1; + AT91PS_PIO pio = AT91C_BASE_PIOA; + + /*shutdown the console to avoid strange chars during reset */ + us->US_CR = (AT91C_US_RSTRX | AT91C_US_RSTTX); + + /* Clear PA19 to trigger the hard reset */ + pio->PIO_CODR = 0x00080000; + pio->PIO_OER = 0x00080000; + pio->PIO_PER = 0x00080000; + /* Never reached */ +#endif + return 0; +} + +void icache_enable(void) +{ + ulong reg; + reg = read_p15_c1(); + cp_delay(); + write_p15_c1(reg | C1_IDC); +} + +void icache_disable(void) +{ + ulong reg; + reg = read_p15_c1(); + cp_delay(); + write_p15_c1(reg & ~C1_IDC); +} + +int icache_status(void) +{ + return (read_p15_c1() & C1_IDC) != 0; + return 0; +} + +void dcache_enable(void) +{ + ulong reg; + reg = read_p15_c1(); + cp_delay(); + write_p15_c1(reg | C1_IDC); +} + +void dcache_disable(void) +{ + ulong reg; + reg = read_p15_c1(); + cp_delay(); + write_p15_c1(reg & ~C1_IDC); +} + +int dcache_status(void) +{ + return (read_p15_c1() & C1_IDC) != 0; + return 0; +} |