diff options
Diffstat (limited to 'arch/arm/plat-omap')
| -rw-r--r-- | arch/arm/plat-omap/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/plat-omap/cpu-omap.c | 128 |
2 files changed, 129 insertions, 0 deletions
diff --git a/arch/arm/plat-omap/Makefile b/arch/arm/plat-omap/Makefile index 3be25ebfc45..531e11af54d 100644 --- a/arch/arm/plat-omap/Makefile +++ b/arch/arm/plat-omap/Makefile @@ -14,3 +14,4 @@ obj-$(CONFIG_ARCH_OMAP16XX) += ocpi.o # Power Management obj-$(CONFIG_PM) += pm.o sleep.o +obj-$(CONFIG_CPU_FREQ) += cpu-omap.o diff --git a/arch/arm/plat-omap/cpu-omap.c b/arch/arm/plat-omap/cpu-omap.c new file mode 100644 index 00000000000..409aac2c4b9 --- /dev/null +++ b/arch/arm/plat-omap/cpu-omap.c @@ -0,0 +1,128 @@ +/* + * linux/arch/arm/plat-omap/cpu-omap.c + * + * CPU frequency scaling for OMAP + * + * Copyright (C) 2005 Nokia Corporation + * Written by Tony Lindgren <tony@atomide.com> + * + * Based on cpu-sa1110.c, Copyright (C) 2001 Russell King + * + * 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/types.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/cpufreq.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/err.h> + +#include <asm/hardware.h> +#include <asm/mach-types.h> +#include <asm/io.h> +#include <asm/system.h> + +#include <asm/hardware/clock.h> + +/* TODO: Add support for SDRAM timing changes */ + +int omap_verify_speed(struct cpufreq_policy *policy) +{ + struct clk * mpu_clk; + + if (policy->cpu) + return -EINVAL; + + cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, + policy->cpuinfo.max_freq); + mpu_clk = clk_get(NULL, "mpu"); + if (IS_ERR(mpu_clk)) + return PTR_ERR(mpu_clk); + policy->min = clk_round_rate(mpu_clk, policy->min * 1000) / 1000; + policy->max = clk_round_rate(mpu_clk, policy->max * 1000) / 1000; + cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, + policy->cpuinfo.max_freq); + clk_put(mpu_clk); + + return 0; +} + +unsigned int omap_getspeed(unsigned int cpu) +{ + struct clk * mpu_clk; + unsigned long rate; + + if (cpu) + return 0; + + mpu_clk = clk_get(NULL, "mpu"); + if (IS_ERR(mpu_clk)) + return 0; + rate = clk_get_rate(mpu_clk) / 1000; + clk_put(mpu_clk); + + return rate; +} + +static int omap_target(struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation) +{ + struct clk * mpu_clk; + struct cpufreq_freqs freqs; + int ret = 0; + + mpu_clk = clk_get(NULL, "mpu"); + if (IS_ERR(mpu_clk)) + return PTR_ERR(mpu_clk); + + freqs.old = omap_getspeed(0); + freqs.new = clk_round_rate(mpu_clk, target_freq * 1000) / 1000; + freqs.cpu = 0; + + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); + ret = clk_set_rate(mpu_clk, target_freq * 1000); + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); + clk_put(mpu_clk); + + return ret; +} + +static int __init omap_cpu_init(struct cpufreq_policy *policy) +{ + struct clk * mpu_clk; + + mpu_clk = clk_get(NULL, "mpu"); + if (IS_ERR(mpu_clk)) + return PTR_ERR(mpu_clk); + + if (policy->cpu != 0) + return -EINVAL; + policy->cur = policy->min = policy->max = omap_getspeed(0); + policy->governor = CPUFREQ_DEFAULT_GOVERNOR; + policy->cpuinfo.min_freq = clk_round_rate(mpu_clk, 0) / 1000; + policy->cpuinfo.max_freq = clk_round_rate(mpu_clk, 216000000) / 1000; + policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; + clk_put(mpu_clk); + + return 0; +} + +static struct cpufreq_driver omap_driver = { + .flags = CPUFREQ_STICKY, + .verify = omap_verify_speed, + .target = omap_target, + .get = omap_getspeed, + .init = omap_cpu_init, + .name = "omap", +}; + +static int __init omap_cpufreq_init(void) +{ + return cpufreq_register_driver(&omap_driver); +} + +arch_initcall(omap_cpufreq_init); |