rt-thread/libcpu/arm/s3c24x0/clock.c

78 lines
1.3 KiB
C

/*
* File : clock.c
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2006, RT-Thread Development Team
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://openlab.rt-thread.com/license/LICENSE
*
* Change Logs:
* Date Author Notes
* 2008-04-25 Yi.qiu first version
*/
#include <rtthread.h>
#include "s3c24x0.h"
#define CONFIG_SYS_CLK_FREQ 12000000 // Fin = 12.00MHz
rt_uint32_t PCLK;
rt_uint32_t FCLK;
rt_uint32_t HCLK;
rt_uint32_t UCLK;
void rt_hw_get_clock(void)
{
rt_uint32_t val;
rt_uint8_t m, p, s;
val = MPLLCON;
m = (val>>12)&0xff;
p = (val>>4)&0x3f;
s = val&3;
FCLK = ((m+8)*(CONFIG_SYS_CLK_FREQ/100)*2)/((p+2)*(1<<s))*100;
val = CLKDIVN;
m = (val>>1)&3;
p = val&1;
switch (m) {
case 0:
HCLK = FCLK;
break;
case 1:
HCLK = FCLK>>1;
break;
case 2:
if(s&2)
HCLK = FCLK>>3;
else
HCLK = FCLK>>2;
break;
case 3:
if(s&1)
HCLK = FCLK/6;
else
HCLK = FCLK/3;
break;
}
if(p)
PCLK = HCLK>>1;
else
PCLK = HCLK;
}
void rt_hw_set_clock(rt_uint8_t sdiv, rt_uint8_t pdiv, rt_uint8_t mdiv)
{
MPLLCON = sdiv | pdiv<<4 | mdiv<<12;
}
void rt_hw_set_dividor(rt_uint8_t hdivn, rt_uint8_t pdivn)
{
CLKDIVN = (hdivn<<1) | pdivn;
}