| /* |
| * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd. |
| * http://www.samsung.com |
| * |
| * EXYNOS - CPU frequency scaling support for EXYNOS series |
| * |
| * 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/err.h> |
| #include <linux/clk.h> |
| #include <linux/io.h> |
| #include <linux/slab.h> |
| #include <linux/regulator/consumer.h> |
| #include <linux/cpufreq.h> |
| #include <linux/suspend.h> |
| #include <linux/notifier.h> |
| #include <linux/reboot.h> |
| |
| #include <plat/cpu.h> |
| |
| #include "exynos-cpufreq.h" |
| |
| static struct exynos_dvfs_info *exynos_info; |
| |
| static struct regulator *arm_regulator; |
| |
| static unsigned int locking_frequency; |
| static bool frequency_locked; |
| static DEFINE_MUTEX(cpufreq_lock); |
| |
| static unsigned int exynos_getspeed(unsigned int cpu) |
| { |
| return clk_get_rate(exynos_info->cpu_clk) / 1000; |
| } |
| |
| static int exynos_cpufreq_get_index(unsigned int freq) |
| { |
| struct cpufreq_frequency_table *freq_table = exynos_info->freq_table; |
| int index; |
| |
| for (index = 0; |
| freq_table[index].frequency != CPUFREQ_TABLE_END; index++) |
| if (freq_table[index].frequency == freq) |
| break; |
| |
| if (freq_table[index].frequency == CPUFREQ_TABLE_END) |
| return -EINVAL; |
| |
| return index; |
| } |
| |
| static int exynos_cpufreq_scale(unsigned int target_freq) |
| { |
| struct cpufreq_frequency_table *freq_table = exynos_info->freq_table; |
| unsigned int *volt_table = exynos_info->volt_table; |
| struct cpufreq_policy *policy = cpufreq_cpu_get(0); |
| unsigned int arm_volt, safe_arm_volt = 0; |
| unsigned int mpll_freq_khz = exynos_info->mpll_freq_khz; |
| unsigned int old_freq; |
| int index, old_index; |
| int ret = 0; |
| |
| old_freq = policy->cur; |
| |
| /* |
| * The policy max have been changed so that we cannot get proper |
| * old_index with cpufreq_frequency_table_target(). Thus, ignore |
| * policy and get the index from the raw frequency table. |
| */ |
| old_index = exynos_cpufreq_get_index(old_freq); |
| if (old_index < 0) { |
| ret = old_index; |
| goto out; |
| } |
| |
| index = exynos_cpufreq_get_index(target_freq); |
| if (index < 0) { |
| ret = index; |
| goto out; |
| } |
| |
| /* |
| * ARM clock source will be changed APLL to MPLL temporary |
| * To support this level, need to control regulator for |
| * required voltage level |
| */ |
| if (exynos_info->need_apll_change != NULL) { |
| if (exynos_info->need_apll_change(old_index, index) && |
| (freq_table[index].frequency < mpll_freq_khz) && |
| (freq_table[old_index].frequency < mpll_freq_khz)) |
| safe_arm_volt = volt_table[exynos_info->pll_safe_idx]; |
| } |
| arm_volt = volt_table[index]; |
| |
| /* When the new frequency is higher than current frequency */ |
| if ((target_freq > old_freq) && !safe_arm_volt) { |
| /* Firstly, voltage up to increase frequency */ |
| ret = regulator_set_voltage(arm_regulator, arm_volt, arm_volt); |
| if (ret) { |
| pr_err("%s: failed to set cpu voltage to %d\n", |
| __func__, arm_volt); |
| return ret; |
| } |
| } |
| |
| if (safe_arm_volt) { |
| ret = regulator_set_voltage(arm_regulator, safe_arm_volt, |
| safe_arm_volt); |
| if (ret) { |
| pr_err("%s: failed to set cpu voltage to %d\n", |
| __func__, safe_arm_volt); |
| return ret; |
| } |
| } |
| |
| exynos_info->set_freq(old_index, index); |
| |
| /* When the new frequency is lower than current frequency */ |
| if ((target_freq < old_freq) || |
| ((target_freq > old_freq) && safe_arm_volt)) { |
| /* down the voltage after frequency change */ |
| ret = regulator_set_voltage(arm_regulator, arm_volt, |
| arm_volt); |
| if (ret) { |
| pr_err("%s: failed to set cpu voltage to %d\n", |
| __func__, arm_volt); |
| goto out; |
| } |
| } |
| |
| out: |
| cpufreq_cpu_put(policy); |
| |
| return ret; |
| } |
| |
| static int exynos_target(struct cpufreq_policy *policy, unsigned int index) |
| { |
| struct cpufreq_frequency_table *freq_table = exynos_info->freq_table; |
| int ret = 0; |
| |
| mutex_lock(&cpufreq_lock); |
| |
| if (frequency_locked) |
| goto out; |
| |
| ret = exynos_cpufreq_scale(freq_table[index].frequency); |
| |
| out: |
| mutex_unlock(&cpufreq_lock); |
| |
| return ret; |
| } |
| |
| #ifdef CONFIG_PM |
| static int exynos_cpufreq_suspend(struct cpufreq_policy *policy) |
| { |
| return 0; |
| } |
| |
| static int exynos_cpufreq_resume(struct cpufreq_policy *policy) |
| { |
| return 0; |
| } |
| #endif |
| |
| /** |
| * exynos_cpufreq_pm_notifier - block CPUFREQ's activities in suspend-resume |
| * context |
| * @notifier |
| * @pm_event |
| * @v |
| * |
| * While frequency_locked == true, target() ignores every frequency but |
| * locking_frequency. The locking_frequency value is the initial frequency, |
| * which is set by the bootloader. In order to eliminate possible |
| * inconsistency in clock values, we save and restore frequencies during |
| * suspend and resume and block CPUFREQ activities. Note that the standard |
| * suspend/resume cannot be used as they are too deep (syscore_ops) for |
| * regulator actions. |
| */ |
| static int exynos_cpufreq_pm_notifier(struct notifier_block *notifier, |
| unsigned long pm_event, void *v) |
| { |
| int ret; |
| |
| switch (pm_event) { |
| case PM_SUSPEND_PREPARE: |
| mutex_lock(&cpufreq_lock); |
| frequency_locked = true; |
| mutex_unlock(&cpufreq_lock); |
| |
| ret = exynos_cpufreq_scale(locking_frequency); |
| if (ret < 0) |
| return NOTIFY_BAD; |
| |
| break; |
| |
| case PM_POST_SUSPEND: |
| mutex_lock(&cpufreq_lock); |
| frequency_locked = false; |
| mutex_unlock(&cpufreq_lock); |
| break; |
| } |
| |
| return NOTIFY_OK; |
| } |
| |
| static struct notifier_block exynos_cpufreq_nb = { |
| .notifier_call = exynos_cpufreq_pm_notifier, |
| }; |
| |
| static int exynos_cpufreq_reboot_notifier(struct notifier_block *this, |
| unsigned long code, void *_cmd) |
| { |
| struct cpufreq_policy *policy = cpufreq_cpu_get(0); /* boot CPU */ |
| mutex_lock(&cpufreq_lock); |
| |
| if (frequency_locked) |
| goto out; |
| frequency_locked = true; |
| |
| if (locking_frequency) { |
| mutex_unlock(&cpufreq_lock); |
| exynos_target(policy, locking_frequency, CPUFREQ_RELATION_H); |
| mutex_lock(&cpufreq_lock); |
| } |
| |
| out: |
| mutex_unlock(&cpufreq_lock); |
| return NOTIFY_DONE; |
| } |
| |
| static struct notifier_block exynos_cpufreq_reboot_nb = { |
| .notifier_call = exynos_cpufreq_reboot_notifier, |
| }; |
| |
| static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy) |
| { |
| return cpufreq_generic_init(policy, exynos_info->freq_table, 100000); |
| } |
| |
| static struct cpufreq_driver exynos_driver = { |
| .flags = CPUFREQ_STICKY, |
| .verify = cpufreq_generic_frequency_table_verify, |
| .target_index = exynos_target, |
| .get = exynos_getspeed, |
| .init = exynos_cpufreq_cpu_init, |
| .exit = cpufreq_generic_exit, |
| .name = "exynos_cpufreq", |
| .attr = cpufreq_generic_attr, |
| #ifdef CONFIG_PM |
| .suspend = exynos_cpufreq_suspend, |
| .resume = exynos_cpufreq_resume, |
| #endif |
| }; |
| |
| static int __init exynos_cpufreq_init(void) |
| { |
| int ret = -EINVAL; |
| |
| exynos_info = kzalloc(sizeof(*exynos_info), GFP_KERNEL); |
| if (!exynos_info) |
| return -ENOMEM; |
| |
| if (soc_is_exynos4210()) |
| ret = exynos4210_cpufreq_init(exynos_info); |
| else if (soc_is_exynos4212() || soc_is_exynos4412()) |
| ret = exynos4x12_cpufreq_init(exynos_info); |
| else if (soc_is_exynos5250()) |
| ret = exynos5250_cpufreq_init(exynos_info); |
| else |
| return 0; |
| |
| if (ret) |
| goto err_vdd_arm; |
| |
| if (exynos_info->set_freq == NULL) { |
| pr_err("%s: No set_freq function (ERR)\n", __func__); |
| goto err_vdd_arm; |
| } |
| |
| arm_regulator = regulator_get(NULL, "vdd_arm"); |
| if (IS_ERR(arm_regulator)) { |
| pr_err("%s: failed to get resource vdd_arm\n", __func__); |
| goto err_vdd_arm; |
| } |
| |
| locking_frequency = exynos_getspeed(0); |
| |
| register_pm_notifier(&exynos_cpufreq_nb); |
| register_reboot_notifier(&exynos_cpufreq_reboot_nb); |
| |
| if (cpufreq_register_driver(&exynos_driver)) { |
| pr_err("%s: failed to register cpufreq driver\n", __func__); |
| goto err_cpufreq; |
| } |
| |
| return 0; |
| err_cpufreq: |
| unregister_pm_notifier(&exynos_cpufreq_nb); |
| |
| regulator_put(arm_regulator); |
| err_vdd_arm: |
| kfree(exynos_info); |
| return -EINVAL; |
| } |
| late_initcall(exynos_cpufreq_init); |