cmd_cache.c

source code of armboot for s3c4510

/*
 * (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
 */

/*
 * Cache support: switch on or off, get status  choish 20020829
 */
#include <armboot.h>
#include <command.h>

#if defined(CONFIG_S3C2500) || defined(CONFIG_S3C2510)
#define DCACHE_ON (1<<2)     // dcaceh enable choish 20020827
#define ICACHE_ON (1<<12)     // icache enable  choish 20020827


//#if (CONFIG_COMMANDS & CFG_CMD_CACHE)

static int on_off (const char*);

// CP15 r1 Resister read function   choish 20020827
static unsigned long read_cp15r1(void) 
{
    unsigned long value;

    __asm__ __volatile__(
	"mrc     p15, 0, %0, c1, c0, 0   @ read control reg\n"
	: "=r" (value)
	:
	: "memory");
    printf("cp15 register : %08lx\n", value);
    return value;
}


void Cache_init(bd_t * bd)
{
  const char *is; 
  const char *ds;
  is = bd->bi_icache;
 	 switch (on_off(is)) {
				case 0:	
					 _ICache_Flush();
					 _ICache_Disable();
										 
					break;
				case 1:	            
					 _ICache_Enable();
					 _ICache_Flush();
				     				     
					break;
			}
#ifdef VIADBG
 	 	printf ("Instruction Cache is %s\n", icache_status() ? "ON" : "OFF");
#endif 	 	
	ds = bd->bi_dcache;
		switch (on_off(ds)) {
				case 0:
					_DCache_Flush();
			 		_DCache_Disable();
			 		break;
				case 1:
			 		_DCache_Enable();
			 		_DCache_Flush();
			 		break;
			}
#ifdef VIADBG
		printf ("Data (writethrough) Cache is %s\n",dcache_status() ? "ON" : "OFF");
#endif
}


int icache_status(void)
{
  	return (read_cp15r1() & ICACHE_ON) != 0;
}

int dcache_status(void)
{
  	return (read_cp15r1() & DCACHE_ON) != 0;
}
#endif

static int on_off (const char *s)
{
	if (strcmp(s, "on") == 0) {
		return (1);
	} else if (strcmp(s, "off") == 0) {
		return (0);
	}
	return (-1);
}