| /* |
| * cpufreq driver for the SuperH processors. |
| * |
| * Copyright (C) 2002 - 2012 Paul Mundt |
| * Copyright (C) 2002 M. R. Brown |
| * |
| * Clock framework bits from arch/avr32/mach-at32ap/cpufreq.c |
| * |
| * Copyright (C) 2004-2007 Atmel Corporation |
| * |
| * This file is subject to the terms and conditions of the GNU General Public |
| * License. See the file "COPYING" in the main directory of this archive |
| * for more details. |
| */ |
| #define pr_fmt(fmt) "cpufreq: " fmt |
| |
| #include <linux/types.h> |
| #include <linux/cpufreq.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/err.h> |
| #include <linux/cpumask.h> |
| #include <linux/cpu.h> |
| #include <linux/smp.h> |
| #include <linux/sched.h> /* set_cpus_allowed() */ |
| #include <linux/clk.h> |
| #include <linux/percpu.h> |
| #include <linux/sh_clk.h> |
| |
| static DEFINE_PER_CPU(struct clk, sh_cpuclk); |
| |
| static unsigned int sh_cpufreq_get(unsigned int cpu) |
| { |
| return (clk_get_rate(&per_cpu(sh_cpuclk, cpu)) + 500) / 1000; |
| } |
| |
| /* |
| * Here we notify other drivers of the proposed change and the final change. |
| */ |
| static int sh_cpufreq_target(struct cpufreq_policy *policy, |
| unsigned int target_freq, |
| unsigned int relation) |
| { |
| unsigned int cpu = policy->cpu; |
| struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu); |
| cpumask_t cpus_allowed; |
| struct cpufreq_freqs freqs; |
| struct device *dev; |
| long freq; |
| |
| cpus_allowed = current->cpus_allowed; |
| set_cpus_allowed_ptr(current, cpumask_of(cpu)); |
| |
| BUG_ON(smp_processor_id() != cpu); |
| |
| dev = get_cpu_device(cpu); |
| |
| /* Convert target_freq from kHz to Hz */ |
| freq = clk_round_rate(cpuclk, target_freq * 1000); |
| |
| if (freq < (policy->min * 1000) || freq > (policy->max * 1000)) |
| return -EINVAL; |
| |
| dev_dbg(dev, "requested frequency %u Hz\n", target_freq * 1000); |
| |
| freqs.cpu = cpu; |
| freqs.old = sh_cpufreq_get(cpu); |
| freqs.new = (freq + 500) / 1000; |
| freqs.flags = 0; |
| |
| cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); |
| set_cpus_allowed_ptr(current, &cpus_allowed); |
| clk_set_rate(cpuclk, freq); |
| cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); |
| |
| dev_dbg(dev, "set frequency %lu Hz\n", freq); |
| |
| return 0; |
| } |
| |
| static int sh_cpufreq_verify(struct cpufreq_policy *policy) |
| { |
| struct clk *cpuclk = &per_cpu(sh_cpuclk, policy->cpu); |
| struct cpufreq_frequency_table *freq_table; |
| |
| freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL; |
| if (freq_table) |
| return cpufreq_frequency_table_verify(policy, freq_table); |
| |
| cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, |
| policy->cpuinfo.max_freq); |
| |
| policy->min = (clk_round_rate(cpuclk, 1) + 500) / 1000; |
| policy->max = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000; |
| |
| cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, |
| policy->cpuinfo.max_freq); |
| |
| return 0; |
| } |
| |
| static int sh_cpufreq_cpu_init(struct cpufreq_policy *policy) |
| { |
| unsigned int cpu = policy->cpu; |
| struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu); |
| struct cpufreq_frequency_table *freq_table; |
| struct device *dev; |
| |
| dev = get_cpu_device(cpu); |
| |
| cpuclk = clk_get(dev, "cpu_clk"); |
| if (IS_ERR(cpuclk)) { |
| dev_err(dev, "couldn't get CPU clk\n"); |
| return PTR_ERR(cpuclk); |
| } |
| |
| policy->cur = sh_cpufreq_get(cpu); |
| |
| freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL; |
| if (freq_table) { |
| int result; |
| |
| result = cpufreq_frequency_table_cpuinfo(policy, freq_table); |
| if (!result) |
| cpufreq_frequency_table_get_attr(freq_table, cpu); |
| } else { |
| dev_notice(dev, "no frequency table found, falling back " |
| "to rate rounding.\n"); |
| |
| policy->min = policy->cpuinfo.min_freq = |
| (clk_round_rate(cpuclk, 1) + 500) / 1000; |
| policy->max = policy->cpuinfo.max_freq = |
| (clk_round_rate(cpuclk, ~0UL) + 500) / 1000; |
| } |
| |
| policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; |
| |
| dev_info(dev, "CPU Frequencies - Minimum %u.%03u MHz, " |
| "Maximum %u.%03u MHz.\n", |
| policy->min / 1000, policy->min % 1000, |
| policy->max / 1000, policy->max % 1000); |
| |
| return 0; |
| } |
| |
| static int sh_cpufreq_cpu_exit(struct cpufreq_policy *policy) |
| { |
| unsigned int cpu = policy->cpu; |
| struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu); |
| |
| cpufreq_frequency_table_put_attr(cpu); |
| clk_put(cpuclk); |
| |
| return 0; |
| } |
| |
| static struct freq_attr *sh_freq_attr[] = { |
| &cpufreq_freq_attr_scaling_available_freqs, |
| NULL, |
| }; |
| |
| static struct cpufreq_driver sh_cpufreq_driver = { |
| .owner = THIS_MODULE, |
| .name = "sh", |
| .get = sh_cpufreq_get, |
| .target = sh_cpufreq_target, |
| .verify = sh_cpufreq_verify, |
| .init = sh_cpufreq_cpu_init, |
| .exit = sh_cpufreq_cpu_exit, |
| .attr = sh_freq_attr, |
| }; |
| |
| static int __init sh_cpufreq_module_init(void) |
| { |
| pr_notice("SuperH CPU frequency driver.\n"); |
| return cpufreq_register_driver(&sh_cpufreq_driver); |
| } |
| |
| static void __exit sh_cpufreq_module_exit(void) |
| { |
| cpufreq_unregister_driver(&sh_cpufreq_driver); |
| } |
| |
| module_init(sh_cpufreq_module_init); |
| module_exit(sh_cpufreq_module_exit); |
| |
| MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>"); |
| MODULE_DESCRIPTION("cpufreq driver for SuperH"); |
| MODULE_LICENSE("GPL"); |