diff options
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r-- | drivers/cpufreq/Makefile | 1 | ||||
-rw-r--r-- | drivers/cpufreq/unicore2-cpufreq.c | 92 |
2 files changed, 93 insertions, 0 deletions
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index 3930d2e6a664..18479b27f759 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -84,3 +84,4 @@ obj-$(CONFIG_ETRAXFS) += cris-etraxfs-cpufreq.o obj-$(CONFIG_IA64_ACPI_CPUFREQ) += ia64-acpi-cpufreq.o obj-$(CONFIG_LOONGSON2_CPUFREQ) += loongson2_cpufreq.o obj-$(CONFIG_SH_CPU_FREQ) += sh-cpufreq.o +obj-$(CONFIG_UNICORE32) += unicore2-cpufreq.o diff --git a/drivers/cpufreq/unicore2-cpufreq.c b/drivers/cpufreq/unicore2-cpufreq.c new file mode 100644 index 000000000000..12fc904d7dab --- /dev/null +++ b/drivers/cpufreq/unicore2-cpufreq.c @@ -0,0 +1,92 @@ +/* + * clock scaling for the UniCore-II + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn> + * Copyright (C) 2001-2010 Guan Xuetao + * + * 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/types.h> +#include <linux/init.h> +#include <linux/clk.h> +#include <linux/cpufreq.h> + +#include <mach/hardware.h> + +static struct cpufreq_driver ucv2_driver; + +/* make sure that only the "userspace" governor is run + * -- anything else wouldn't make sense on this platform, anyway. + */ +int ucv2_verify_speed(struct cpufreq_policy *policy) +{ + if (policy->cpu) + return -EINVAL; + + cpufreq_verify_within_limits(policy, + policy->cpuinfo.min_freq, policy->cpuinfo.max_freq); + + return 0; +} + +static unsigned int ucv2_getspeed(unsigned int cpu) +{ + struct clk *mclk = clk_get(NULL, "MAIN_CLK"); + + if (cpu) + return 0; + return clk_get_rate(mclk)/1000; +} + +static int ucv2_target(struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation) +{ + unsigned int cur = ucv2_getspeed(0); + struct cpufreq_freqs freqs; + struct clk *mclk = clk_get(NULL, "MAIN_CLK"); + + cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); + + if (!clk_set_rate(mclk, target_freq * 1000)) { + freqs.old = cur; + freqs.new = target_freq; + } + + cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); + + return 0; +} + +static int __init ucv2_cpu_init(struct cpufreq_policy *policy) +{ + if (policy->cpu != 0) + return -EINVAL; + policy->cur = ucv2_getspeed(0); + policy->min = policy->cpuinfo.min_freq = 250000; + policy->max = policy->cpuinfo.max_freq = 1000000; + policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; + return 0; +} + +static struct cpufreq_driver ucv2_driver = { + .flags = CPUFREQ_STICKY, + .verify = ucv2_verify_speed, + .target = ucv2_target, + .get = ucv2_getspeed, + .init = ucv2_cpu_init, + .name = "UniCore-II", +}; + +static int __init ucv2_cpufreq_init(void) +{ + return cpufreq_register_driver(&ucv2_driver); +} + +arch_initcall(ucv2_cpufreq_init); |