u-boot/arch/arm/cpu/arm920t/s3c24x0/speed.c

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/*
* (C) Copyright 2001-2004
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* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* (C) Copyright 2002
* David Mueller, ELSOFT AG, d.mueller@elsoft.ch
*
* SPDX-License-Identifier: GPL-2.0+
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*/
/* 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>
#ifdef CONFIG_S3C24X0
#include <asm/io.h>
#include <asm/arch/s3c24x0_cpu.h>
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#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.
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*
* get_FCLK(), get_HCLK(), get_PCLK() and get_UCLK() return the clock of
* the specified bus in HZ.
*/
/* ------------------------------------------------------------------------- */
static ulong get_PLLCLK(int pllreg)
{
struct s3c24x0_clock_power *clk_power = s3c24x0_get_base_clock_power();
ulong r, m, p, s;
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if (pllreg == MPLL)
r = readl(&clk_power->mpllcon);
else if (pllreg == UPLL)
r = readl(&clk_power->upllcon);
else
hang();
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m = ((r & 0xFF000) >> 12) + 8;
p = ((r & 0x003F0) >> 4) + 2;
s = r & 0x3;
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#if defined(CONFIG_S3C2440)
if (pllreg == MPLL)
return 2 * m * (CONFIG_SYS_CLK_FREQ / (p << s));
#endif
return (CONFIG_SYS_CLK_FREQ * m) / (p << s);
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}
/* return FCLK frequency */
ulong get_FCLK(void)
{
return get_PLLCLK(MPLL);
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}
/* return HCLK frequency */
ulong get_HCLK(void)
{
struct s3c24x0_clock_power *clk_power = s3c24x0_get_base_clock_power();
#ifdef CONFIG_S3C2440
switch (readl(&clk_power->clkdivn) & 0x6) {
default:
case 0:
return get_FCLK();
case 2:
return get_FCLK() / 2;
case 4:
return (readl(&clk_power->camdivn) & (1 << 9)) ?
get_FCLK() / 8 : get_FCLK() / 4;
case 6:
return (readl(&clk_power->camdivn) & (1 << 8)) ?
get_FCLK() / 6 : get_FCLK() / 3;
}
#else
return (readl(&clk_power->clkdivn) & 2) ? get_FCLK() / 2 : get_FCLK();
#endif
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}
/* return PCLK frequency */
ulong get_PCLK(void)
{
struct s3c24x0_clock_power *clk_power = s3c24x0_get_base_clock_power();
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return (readl(&clk_power->clkdivn) & 1) ? get_HCLK() / 2 : get_HCLK();
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}
/* return UCLK frequency */
ulong get_UCLK(void)
{
return get_PLLCLK(UPLL);
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}
#endif /* CONFIG_S3C24X0 */