diff options
Diffstat (limited to 'arch/arm/cpu/arm920t/s3c24x0/speed.c')
-rw-r--r-- | arch/arm/cpu/arm920t/s3c24x0/speed.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/arch/arm/cpu/arm920t/s3c24x0/speed.c b/arch/arm/cpu/arm920t/s3c24x0/speed.c new file mode 100644 index 0000000000..b13283a798 --- /dev/null +++ b/arch/arm/cpu/arm920t/s3c24x0/speed.c @@ -0,0 +1,98 @@ +/* + * (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> +#ifdef CONFIG_S3C24X0 + +#include <asm/io.h> +#include <asm/arch/s3c24x0_cpu.h> + +#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) +{ + struct s3c24x0_clock_power *clk_power = s3c24x0_get_base_clock_power(); + ulong r, m, p, s; + + if (pllreg == MPLL) + r = readl(&clk_power->MPLLCON); + else if (pllreg == UPLL) + r = readl(&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) +{ + struct s3c24x0_clock_power *clk_power = s3c24x0_get_base_clock_power(); + + return (readl(&clk_power->CLKDIVN) & 2) ? get_FCLK() / 2 : get_FCLK(); +} + +/* return PCLK frequency */ +ulong get_PCLK(void) +{ + struct s3c24x0_clock_power *clk_power = s3c24x0_get_base_clock_power(); + + return (readl(&clk_power->CLKDIVN) & 1) ? get_HCLK() / 2 : get_HCLK(); +} + +/* return UCLK frequency */ +ulong get_UCLK(void) +{ + return get_PLLCLK(UPLL); +} + +#endif /* CONFIG_S3C24X0 */ |