diff options
Diffstat (limited to 'arch/arm/plat-s3c24xx')
| -rw-r--r-- | arch/arm/plat-s3c24xx/Kconfig | 7 | ||||
| -rw-r--r-- | arch/arm/plat-s3c24xx/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/plat-s3c24xx/s3c2410-cpufreq-utils.c | 64 |
3 files changed, 72 insertions, 0 deletions
diff --git a/arch/arm/plat-s3c24xx/Kconfig b/arch/arm/plat-s3c24xx/Kconfig index d82d30c2f059..a547c79ed6ce 100644 --- a/arch/arm/plat-s3c24xx/Kconfig +++ b/arch/arm/plat-s3c24xx/Kconfig @@ -116,6 +116,13 @@ config S3C2410_IOTIMING Internal node to select io timing code that is common to the s3c2410 and s3c2440/s3c2442 cpu frequency support. +config S3C2410_CPUFREQ_UTILS + bool + depends on CPU_FREQ_S3C24XX + help + Internal node to select timing code that is common to the s3c2410 + and s3c2440/s3c244 cpu frequency support. + config MACH_SMDK bool help diff --git a/arch/arm/plat-s3c24xx/Makefile b/arch/arm/plat-s3c24xx/Makefile index 6f9afd13ab4f..b28fe9cb0e5e 100644 --- a/arch/arm/plat-s3c24xx/Makefile +++ b/arch/arm/plat-s3c24xx/Makefile @@ -36,6 +36,7 @@ obj-$(CONFIG_S3C2410_CLOCK) += s3c2410-clock.o obj-$(CONFIG_S3C2410_DMA) += dma.o obj-$(CONFIG_S3C24XX_ADC) += adc.o obj-$(CONFIG_S3C2410_IOTIMING) += s3c2410-iotiming.o +obj-$(CONFIG_S3C2410_CPUFREQ_UTILS) += s3c2410-cpufreq-utils.o # device specific setup and/or initialisation obj-$(CONFIG_ARCH_S3C2410) += setup-i2c.o diff --git a/arch/arm/plat-s3c24xx/s3c2410-cpufreq-utils.c b/arch/arm/plat-s3c24xx/s3c2410-cpufreq-utils.c new file mode 100644 index 000000000000..43ea80190d87 --- /dev/null +++ b/arch/arm/plat-s3c24xx/s3c2410-cpufreq-utils.c @@ -0,0 +1,64 @@ +/* linux/arch/arm/plat-s3c24xx/s3c2410-cpufreq-utils.c + * + * Copyright (c) 2009 Simtec Electronics + * http://armlinux.simtec.co.uk/ + * Ben Dooks <ben@simtec.co.uk> + * + * S3C24XX CPU Frequency scaling - utils for S3C2410/S3C2440/S3C2442 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. +*/ + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/cpufreq.h> +#include <linux/io.h> + +#include <mach/map.h> +#include <mach/regs-mem.h> +#include <mach/regs-clock.h> + +#include <plat/cpu-freq-core.h> + +/** + * s3c2410_cpufreq_setrefresh - set SDRAM refresh value + * @cfg: The frequency configuration + * + * Set the SDRAM refresh value appropriately for the configured + * frequency. + */ +void s3c2410_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg) +{ + struct s3c_cpufreq_board *board = cfg->board; + unsigned long refresh; + unsigned long refval; + + /* Reduce both the refresh time (in ns) and the frequency (in MHz) + * down to ensure that we do not overflow 32 bit numbers. + * + * This should work for HCLK up to 133MHz and refresh period up + * to 30usec. + */ + + refresh = (cfg->freq.hclk / 100) * (board->refresh / 10); + refresh = DIV_ROUND_UP(refresh, (1000 * 1000)); /* apply scale */ + refresh = (1 << 11) + 1 - refresh; + + s3c_freq_dbg("%s: refresh value %lu\n", __func__, refresh); + + refval = __raw_readl(S3C2410_REFRESH); + refval &= ~((1 << 12) - 1); + refval |= refresh; + __raw_writel(refval, S3C2410_REFRESH); +} + +/** + * s3c2410_set_fvco - set the PLL value + * @cfg: The frequency configuration + */ +void s3c2410_set_fvco(struct s3c_cpufreq_config *cfg) +{ + __raw_writel(cfg->pll.index, S3C2410_MPLLCON); +} |