cpu.c

AT91RM9200的完整启动代码：包括loader, boot及U-boot三部分均已编译通过！欢迎下载使用！

/*
 * (C) Copyright 2000
 * Wolfgang Denk, DENX Software Engineering, [e-mail].
 *
 * 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
 */

/*
 * m8xx.c
 *
 * CPU specific code
 *
 * written or collected and sometimes rewritten by
 * Magnus Damm <[e-mail]>
 *
 * minor modifications by
 * Wolfgang Denk <[e-mail]>
 */

#include <common.h>
#include <watchdog.h>
#include <command.h>
#include <asm/cache.h>
#include <ppc4xx.h>


#if defined(CONFIG_440)
static int do_chip_reset( unsigned long sys0, unsigned long sys1 );
#endif

/* ------------------------------------------------------------------------- */

int checkcpu (void)
{
#if defined(CONFIG_405GP) || \
    defined(CONFIG_405CR) || \
    defined(CONFIG_IOP480) || \
    defined(CONFIG_440) || \
    defined(CONFIG_405EP)
	uint pvr = get_pvr();
#endif
#if defined(CONFIG_405GP) || \
    defined(CONFIG_405CR) || \
    defined(CONFIG_IOP480) || \
    defined(CONFIG_405EP)
	DECLARE_GLOBAL_DATA_PTR;

	ulong clock = gd->cpu_clk;
	char buf[32];
#endif

#if defined(CONFIG_405GP) || defined(CONFIG_405CR) || defined(CONFIG_405EP)
	PPC405_SYS_INFO sys_info;

	puts ("CPU:   ");

	get_sys_info(&sys_info);

#if CONFIG_405GP
	puts("IBM PowerPC 405GP");
	if (pvr == PVR_405GPR_RB) {
		putc('r');
	}
	puts(" Rev. ");
#endif
#if CONFIG_405CR
	puts("IBM PowerPC 405CR Rev. ");
#endif
#if CONFIG_405EP
	puts("IBM PowerPC 405EP Rev. ");
#endif
	switch (pvr) {
	case PVR_405GP_RB:
	case PVR_405GPR_RB:
		putc('B');
		break;
	case PVR_405GP_RC:
#if CONFIG_405CR
	case PVR_405CR_RC:
#endif
		putc('C');
		break;
	case PVR_405GP_RD:
		putc('D');
		break;
#if CONFIG_405GP
	case PVR_405GP_RE:
		putc('E');
		break;
#endif
	case PVR_405CR_RA:
		putc('A');
		break;
	case PVR_405CR_RB:
	case PVR_405EP_RB:
		putc('B');
		break;
	default:
		printf("? (PVR=%08x)", pvr);
		break;
	}

	printf(" at %s MHz (PLB=%lu, OPB=%lu, EBC=%lu MHz)\n", strmhz(buf, clock),
	       sys_info.freqPLB / 1000000,
	       sys_info.freqPLB / sys_info.pllOpbDiv / 1000000,
	       sys_info.freqPLB / sys_info.pllExtBusDiv / 1000000);

#if defined(CONFIG_405GP)
	if (mfdcr(strap) & PSR_PCI_ASYNC_EN)
		printf("           PCI async ext clock used, ");
	else
		printf("           PCI sync clock at %lu MHz, ",
		       sys_info.freqPLB / sys_info.pllPciDiv / 1000000);
	if (mfdcr(strap) & PSR_PCI_ARBIT_EN)
		printf("internal PCI arbiter enabled\n");
	else
		printf("external PCI arbiter enabled\n");
#elif defined(CONFIG_405EP)
	if (mfdcr(cpc0_boot) & CPC0_BOOT_SEP)
		printf("           IIC Boot EEPROM enabled\n");
	else
		printf("           IIC Boot EEPROM disabled\n");
	printf("           PCI async ext clock used, ");
	if (mfdcr(cpc0_pci) & CPC0_PCI_ARBIT_EN)
		printf("internal PCI arbiter enabled\n");
	else
		printf("external PCI arbiter enabled\n");
#endif

#if defined(CONFIG_405EP)
	printf("           16 kB I-Cache 16 kB D-Cache");
#else
	if ((pvr | 0x00000001) == PVR_405GPR_RB) {
		printf("           16 kB I-Cache 16 kB D-Cache");
	} else {
		printf("           16 kB I-Cache 8 kB D-Cache");
	}
#endif
#endif  /* defined(CONFIG_405GP) || defined(CONFIG_405CR) */

#ifdef CONFIG_IOP480
	printf("PLX IOP480 (PVR=%08x)", pvr);
	printf(" at %s MHz:", strmhz(buf, clock));
	printf(" %u kB I-Cache", 4);
	printf(" %u kB D-Cache", 2);
#endif

#if defined(CONFIG_440)
	puts("IBM PowerPC 440 Rev. ");
	switch(pvr)
	{
        case PVR_440GP_RB:
		putc('B');
        /* See errata 1.12: CHIP_4 */
        if(   ( mfdcr(cpc0_sys0) != mfdcr(cpc0_strp0) )
            ||( mfdcr(cpc0_sys1) != mfdcr(cpc0_strp1) ) ){
            puts("\n\t CPC0_SYSx DCRs corrupted. Resetting chip ...\n");
            udelay( 1000 * 1000 ); /* Give time for serial buf to clear */
            do_chip_reset( mfdcr(cpc0_strp0), mfdcr(cpc0_strp1) );
        }
		break;
        case PVR_440GP_RC:
		putc('C');
		break;
        default:
		printf("UNKNOWN (PVR=%08x)", pvr);
		break;
	}
#endif

	printf("\n");

	return 0;
}


/* ------------------------------------------------------------------------- */

int do_reset (cmd_tbl_t *cmdtp, bd_t *bd, int flag, int argc, char *argv[])
{
        /*
         * Initiate system reset in debug control register DBCR
         */
	__asm__ __volatile__("lis   3, 0x3000" ::: "r3");
#if defined(CONFIG_440)
	__asm__ __volatile__("mtspr 0x134, 3");
#else
	__asm__ __volatile__("mtspr 0x3f2, 3");
#endif
	return 1;
}

#if defined(CONFIG_440)
static
int do_chip_reset( unsigned long sys0, unsigned long sys1 )
{
    /* Changes to cpc0_sys0 and cpc0_sys1 require chip
     * reset.
     */
    mtdcr( cntrl0, mfdcr(cntrl0) | 0x80000000 ); /* Set SWE */
    mtdcr( cpc0_sys0, sys0 );
    mtdcr( cpc0_sys1, sys1 );
    mtdcr( cntrl0, mfdcr(cntrl0) & ~0x80000000 ); /* Clr SWE */
    mtspr( dbcr0, 0x20000000);  /* Reset the chip */

    return 1;
}
#endif


/*
 * Get timebase clock frequency
 */
unsigned long get_tbclk (void)
{
#if defined(CONFIG_440)

	sys_info_t  sys_info;

	get_sys_info(&sys_info);
	return (sys_info.freqProcessor);

#elif defined(CONFIG_405GP) || \
      defined(CONFIG_405CR) || \
      defined(CONFIG_405) || \
      defined(CONFIG_405EP)

	PPC405_SYS_INFO sys_info;

	get_sys_info(&sys_info);
	return (sys_info.freqProcessor);

#elif defined(CONFIG_IOP480)

	return (66000000);

#else

# error get_tbclk() not implemented

#endif

}


#if defined(CONFIG_WATCHDOG)
void
watchdog_reset(void)
{
	int re_enable = disable_interrupts();
	reset_4xx_watchdog();
	if (re_enable) enable_interrupts();
}

void
reset_4xx_watchdog(void)
{
	/*
	 * Clear TSR(WIS) bit
	 */
	mtspr(tsr, 0x40000000);
}
#endif	/* CONFIG_WATCHDOG */