drivers/cpufreq/exynos-cpufreq.c - linux/kernel/git/viro/vfs - Git at Google

 /*
  * 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 <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_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);

 	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);
	/*
	* 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 <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_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);

	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);