b43a7ffbf3
policy->cpus contains all online cpus that have single shared clock line. And their frequencies are always updated together. Many SMP system's cpufreq drivers take care of this in individual drivers but the best place for this code is in cpufreq core. This patch modifies cpufreq_notify_transition() to notify frequency change for all cpus in policy->cpus and hence updates all users of this API. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
92 lines
2.2 KiB
C
92 lines
2.2 KiB
C
/*
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* linux/arch/unicore32/kernel/cpu-ucv2.c: clock scaling for the UniCore-II
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*
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* Code specific to PKUnity SoC and UniCore ISA
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*
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* Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
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* Copyright (C) 2001-2010 Guan Xuetao
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/clk.h>
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#include <linux/cpufreq.h>
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#include <mach/hardware.h>
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static struct cpufreq_driver ucv2_driver;
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/* make sure that only the "userspace" governor is run
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* -- anything else wouldn't make sense on this platform, anyway.
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*/
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int ucv2_verify_speed(struct cpufreq_policy *policy)
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{
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if (policy->cpu)
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return -EINVAL;
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cpufreq_verify_within_limits(policy,
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policy->cpuinfo.min_freq, policy->cpuinfo.max_freq);
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return 0;
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}
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static unsigned int ucv2_getspeed(unsigned int cpu)
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{
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struct clk *mclk = clk_get(NULL, "MAIN_CLK");
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if (cpu)
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return 0;
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return clk_get_rate(mclk)/1000;
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}
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static int ucv2_target(struct cpufreq_policy *policy,
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unsigned int target_freq,
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unsigned int relation)
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{
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unsigned int cur = ucv2_getspeed(0);
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struct cpufreq_freqs freqs;
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struct clk *mclk = clk_get(NULL, "MAIN_CLK");
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cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
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if (!clk_set_rate(mclk, target_freq * 1000)) {
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freqs.old = cur;
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freqs.new = target_freq;
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}
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cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
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return 0;
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}
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static int __init ucv2_cpu_init(struct cpufreq_policy *policy)
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{
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if (policy->cpu != 0)
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return -EINVAL;
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policy->cur = ucv2_getspeed(0);
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policy->min = policy->cpuinfo.min_freq = 250000;
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policy->max = policy->cpuinfo.max_freq = 1000000;
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policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
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return 0;
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}
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static struct cpufreq_driver ucv2_driver = {
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.flags = CPUFREQ_STICKY,
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.verify = ucv2_verify_speed,
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.target = ucv2_target,
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.get = ucv2_getspeed,
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.init = ucv2_cpu_init,
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.name = "UniCore-II",
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};
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static int __init ucv2_cpufreq_init(void)
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{
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return cpufreq_register_driver(&ucv2_driver);
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}
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arch_initcall(ucv2_cpufreq_init);
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