u-boot/cpu/arm920t/s3c24x0/speed.c
wdenk 1d9f410500 Patch by Steven Scholz, 16 Aug 2004:
- Introducing the concept of SoCs "./cpu/$(CPU)/$(SOC)"
- creating subdirs for SoCs ./cpu/arm920t/imx and ./cpu/arm920t/s3c24x0
- moving SoC specific code out of cpu/arm920t/ into cpu/arm920t/$(SOC)/
- moving drivers/s3c24x0_i2c.c and drivers/serial_imx.c out of drivers/
  into cpu/arm920t/$(SOC)/
2004-10-09 22:21:29 +00:00

101 lines
2.8 KiB
C

/*
* (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>
#if defined(CONFIG_S3C2400) || defined (CONFIG_S3C2410) || defined (CONFIG_TRAB)
#if defined(CONFIG_S3C2400)
#include <s3c2400.h>
#elif defined(CONFIG_S3C2410)
#include <s3c2410.h>
#endif
#define MPLL 0
#define UPLL 1
/* ------------------------------------------------------------------------- */
/* 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)
{
S3C24X0_CLOCK_POWER * const clk_power = S3C24X0_GetBase_CLOCK_POWER();
ulong r, m, p, s;
if (pllreg == MPLL)
r = clk_power->MPLLCON;
else if (pllreg == UPLL)
r = clk_power->UPLLCON;
else
hang();
m = ((r & 0xFF000) >> 12) + 8;
p = ((r & 0x003F0) >> 4) + 2;
s = r & 0x3;
return((CONFIG_SYS_CLK_FREQ * m) / (p << s));
}
/* return FCLK frequency */
ulong get_FCLK(void)
{
return(get_PLLCLK(MPLL));
}
/* return HCLK frequency */
ulong get_HCLK(void)
{
S3C24X0_CLOCK_POWER * const clk_power = S3C24X0_GetBase_CLOCK_POWER();
return((clk_power->CLKDIVN & 0x2) ? get_FCLK()/2 : get_FCLK());
}
/* return PCLK frequency */
ulong get_PCLK(void)
{
S3C24X0_CLOCK_POWER * const clk_power = S3C24X0_GetBase_CLOCK_POWER();
return((clk_power->CLKDIVN & 0x1) ? get_HCLK()/2 : get_HCLK());
}
/* return UCLK frequency */
ulong get_UCLK(void)
{
return(get_PLLCLK(UPLL));
}
#endif /* defined(CONFIG_S3C2400) || defined (CONFIG_S3C2410) || defined (CONFIG_TRAB) */