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>
123 lines
3.1 KiB
C
123 lines
3.1 KiB
C
/*
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* Copyright (C) 2004-2007 Atmel Corporation
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*
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* Based on MIPS implementation arch/mips/kernel/time.c
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* Copyright 2001 MontaVista Software Inc.
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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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/*#define DEBUG*/
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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/cpufreq.h>
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#include <linux/io.h>
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/export.h>
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static struct clk *cpuclk;
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static int at32_verify_speed(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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cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
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policy->cpuinfo.max_freq);
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return 0;
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}
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static unsigned int at32_get_speed(unsigned int cpu)
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{
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/* No SMP support */
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if (cpu)
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return 0;
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return (unsigned int)((clk_get_rate(cpuclk) + 500) / 1000);
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}
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static unsigned int ref_freq;
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static unsigned long loops_per_jiffy_ref;
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static int at32_set_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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struct cpufreq_freqs freqs;
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long freq;
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/* Convert target_freq from kHz to Hz */
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freq = clk_round_rate(cpuclk, target_freq * 1000);
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/* Check if policy->min <= new_freq <= policy->max */
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if(freq < (policy->min * 1000) || freq > (policy->max * 1000))
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return -EINVAL;
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pr_debug("cpufreq: requested frequency %u Hz\n", target_freq * 1000);
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freqs.old = at32_get_speed(0);
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freqs.new = (freq + 500) / 1000;
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freqs.flags = 0;
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if (!ref_freq) {
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ref_freq = freqs.old;
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loops_per_jiffy_ref = boot_cpu_data.loops_per_jiffy;
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}
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cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
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if (freqs.old < freqs.new)
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boot_cpu_data.loops_per_jiffy = cpufreq_scale(
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loops_per_jiffy_ref, ref_freq, freqs.new);
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clk_set_rate(cpuclk, freq);
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if (freqs.new < freqs.old)
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boot_cpu_data.loops_per_jiffy = cpufreq_scale(
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loops_per_jiffy_ref, ref_freq, freqs.new);
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cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
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pr_debug("cpufreq: set frequency %lu Hz\n", freq);
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return 0;
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}
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static int __init at32_cpufreq_driver_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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cpuclk = clk_get(NULL, "cpu");
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if (IS_ERR(cpuclk)) {
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pr_debug("cpufreq: could not get CPU clk\n");
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return PTR_ERR(cpuclk);
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}
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policy->cpuinfo.min_freq = (clk_round_rate(cpuclk, 1) + 500) / 1000;
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policy->cpuinfo.max_freq = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
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policy->cpuinfo.transition_latency = 0;
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policy->cur = at32_get_speed(0);
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policy->min = policy->cpuinfo.min_freq;
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policy->max = policy->cpuinfo.max_freq;
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printk("cpufreq: AT32AP CPU frequency driver\n");
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return 0;
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}
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static struct cpufreq_driver at32_driver = {
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.name = "at32ap",
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.owner = THIS_MODULE,
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.init = at32_cpufreq_driver_init,
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.verify = at32_verify_speed,
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.target = at32_set_target,
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.get = at32_get_speed,
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.flags = CPUFREQ_STICKY,
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};
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static int __init at32_cpufreq_init(void)
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{
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return cpufreq_register_driver(&at32_driver);
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}
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late_initcall(at32_cpufreq_init);
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