u-boot/arch/arm/cpu/arm1176/s3c64xx/speed.c

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/*
* (C) Copyright 2001-2004
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* (C) Copyright 2002
* David Mueller, ELSOFT AG, d.mueller@elsoft.ch
*
* 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
*/
/*
* This code should work for both the S3C2400 and the S3C2410
* as they seem to have the same PLL and clock machinery inside.
* The different address mapping is handled by the s3c24xx.h files below.
*/
#include <common.h>
#include <asm/arch/s3c6400.h>
#define APLL 0
#define MPLL 1
#define EPLL 2
/* ------------------------------------------------------------------------- */
/*
* NOTE: This describes the proper use of this file.
*
* CONFIG_SYS_CLK_FREQ should be defined as the input frequency of the PLL.
*
* get_FCLK(), get_HCLK(), get_PCLK() and get_UCLK() return the clock of
* the specified bus in HZ.
*/
/* ------------------------------------------------------------------------- */
static ulong get_PLLCLK(int pllreg)
{
ulong r, m, p, s;
switch (pllreg) {
case APLL:
r = APLL_CON_REG;
break;
case MPLL:
r = MPLL_CON_REG;
break;
case EPLL:
r = EPLL_CON0_REG;
break;
default:
hang();
}
m = (r >> 16) & 0x3ff;
p = (r >> 8) & 0x3f;
s = r & 0x7;
return m * (CONFIG_SYS_CLK_FREQ / (p * (1 << s)));
}
/* return ARMCORE frequency */
ulong get_ARMCLK(void)
{
ulong div;
div = CLK_DIV0_REG;
return get_PLLCLK(APLL) / ((div & 0x7) + 1);
}
/* return FCLK frequency */
ulong get_FCLK(void)
{
return get_PLLCLK(APLL);
}
/* return HCLK frequency */
ulong get_HCLK(void)
{
ulong fclk;
uint hclkx2_div = ((CLK_DIV0_REG >> 9) & 0x7) + 1;
uint hclk_div = ((CLK_DIV0_REG >> 8) & 0x1) + 1;
/*
* Bit 7 exists on s3c6410, and not on s3c6400, it is reserved on
* s3c6400 and is always 0, and it is indeed running in ASYNC mode
*/
if (OTHERS_REG & 0x80)
fclk = get_FCLK(); /* SYNC Mode */
else
fclk = get_PLLCLK(MPLL); /* ASYNC Mode */
return fclk / (hclk_div * hclkx2_div);
}
/* return PCLK frequency */
ulong get_PCLK(void)
{
ulong fclk;
uint hclkx2_div = ((CLK_DIV0_REG >> 9) & 0x7) + 1;
uint pre_div = ((CLK_DIV0_REG >> 12) & 0xf) + 1;
if (OTHERS_REG & 0x80)
fclk = get_FCLK(); /* SYNC Mode */
else
fclk = get_PLLCLK(MPLL); /* ASYNC Mode */
return fclk / (hclkx2_div * pre_div);
}
/* return UCLK frequency */
ulong get_UCLK(void)
{
return get_PLLCLK(EPLL);
}
int print_cpuinfo(void)
{
printf("\nCPU: S3C6400@%luMHz\n", get_ARMCLK() / 1000000);
printf(" Fclk = %luMHz, Hclk = %luMHz, Pclk = %luMHz ",
get_FCLK() / 1000000, get_HCLK() / 1000000,
get_PCLK() / 1000000);
if (OTHERS_REG & 0x80)
printf("(SYNC Mode) \n");
else
printf("(ASYNC Mode) \n");
return 0;
}