arch/arm/mach-omap2/omap2plus-cpufreq.c - kernel/omap - Git at Google

 /*
  *  OMAP2PLUS cpufreq driver
  *
  *  CPU frequency scaling for OMAP using OPP information
  *
  *  Copyright (C) 2005 Nokia Corporation
  *  Written by Tony Lindgren <[email protected]>
  *
  *  Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
  *
  * Copyright (C) 2007-2011 Texas Instruments, Inc.
  * Updated to support OMAP3
  * Rajendra Nayak <[email protected]>
  *
  * 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/types.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/cpufreq.h>
 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/err.h>
 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/opp.h>
 #include <linux/cpu.h>
 #include <linux/earlysuspend.h>
 #include <linux/platform_device.h>

 #include <asm/system.h>
 #include <asm/smp_plat.h>
 #include <asm/cpu.h>

 #include <plat/clock.h>
 #include <plat/omap-pm.h>
 #include <plat/common.h>

 #include <mach/hardware.h>

 #include "dvfs.h"

 #ifdef CONFIG_SMP
 struct lpj_info {
 	unsigned long	ref;
 	unsigned int	freq;
 };

 static DEFINE_PER_CPU(struct lpj_info, lpj_ref);
 static struct lpj_info global_lpj_ref;
 #endif

 static struct cpufreq_frequency_table *freq_table;
 static atomic_t freq_table_users = ATOMIC_INIT(0);
 static struct clk *mpu_clk;
 static char *mpu_clk_name;
 static struct device *mpu_dev;
 static DEFINE_MUTEX(omap_cpufreq_lock);

 static unsigned int max_thermal;
 static unsigned int max_capped;
 static unsigned int max_freq;
 static unsigned int current_target_freq;
 static unsigned int screen_off_max_freq;
 static bool omap_cpufreq_ready;
 static bool omap_cpufreq_suspended;

 static unsigned int omap_getspeed(unsigned int cpu)
 {
 	unsigned long rate;

 	if (cpu >= NR_CPUS)
 		return 0;

 	rate = clk_get_rate(mpu_clk) / 1000;
 	return rate;
 }

 static int omap_cpufreq_scale(unsigned int target_freq, unsigned int cur_freq)
 {
 	unsigned int i;
 	int ret;
 	struct cpufreq_freqs freqs;

 	freqs.new = target_freq;
 	freqs.old = omap_getspeed(0);

 	/*
 	 * If the new frequency is more than the thermal max allowed
 	 * frequency, go ahead and scale the mpu device to proper frequency.
 	 */
 	if (freqs.new > max_thermal)
 		freqs.new = max_thermal;

 	if (max_capped && freqs.new > max_capped)
 		freqs.new = max_capped;

 	if ((freqs.old == freqs.new) && (cur_freq = freqs.new))
 		return 0;

 	get_online_cpus();

 	/* notifiers */
 	for_each_online_cpu(freqs.cpu)
 		cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

 #ifdef CONFIG_CPU_FREQ_DEBUG
 	pr_info("cpufreq-omap: transition: %u --> %u\n", freqs.old, freqs.new);
 #endif

 	ret = omap_device_scale(mpu_dev, mpu_dev, freqs.new * 1000);

 	freqs.new = omap_getspeed(0);

 #ifdef CONFIG_SMP
 	/*
 	 * Note that loops_per_jiffy is not updated on SMP systems in
 	 * cpufreq driver. So, update the per-CPU loops_per_jiffy value
 	 * on frequency transition. We need to update all dependent CPUs.
 	 */
 	for_each_possible_cpu(i) {
 		struct lpj_info *lpj = &per_cpu(lpj_ref, i);
 		if (!lpj->freq) {
 			lpj->ref = per_cpu(cpu_data, i).loops_per_jiffy;
 			lpj->freq = freqs.old;
 		}

 		per_cpu(cpu_data, i).loops_per_jiffy =
 			cpufreq_scale(lpj->ref, lpj->freq, freqs.new);
 	}

 	/* And don't forget to adjust the global one */
 	if (!global_lpj_ref.freq) {
 		global_lpj_ref.ref = loops_per_jiffy;
 		global_lpj_ref.freq = freqs.old;
 	}
 	loops_per_jiffy = cpufreq_scale(global_lpj_ref.ref, global_lpj_ref.freq,
 					freqs.new);
 #endif

 	/* notifiers */
 	for_each_online_cpu(freqs.cpu)
 		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

 	put_online_cpus();

 	return ret;
 }

 static unsigned int omap_thermal_lower_speed(void)
 {
 	unsigned int max = 0;
 	unsigned int curr;
 	int i;

 	curr = max_thermal;

 	for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++)
 		if (freq_table[i].frequency > max &&
 		    freq_table[i].frequency < curr)
 			max = freq_table[i].frequency;

 	if (!max)
 		return curr;

 	return max;
 }

 void omap_thermal_throttle(void)
 {
 	unsigned int cur;

 	if (!omap_cpufreq_ready) {
 		pr_warn_once("%s: Thermal throttle prior to CPUFREQ ready\n",
 			     __func__);
 		return;
 	}

 	mutex_lock(&omap_cpufreq_lock);

 	max_thermal = omap_thermal_lower_speed();

 	pr_warn("%s: temperature too high, cpu throttle at max %u\n",
 		__func__, max_thermal);

 	if (!omap_cpufreq_suspended) {
 		cur = omap_getspeed(0);
 		if (cur > max_thermal)
 			omap_cpufreq_scale(max_thermal, cur);
 	}

 	mutex_unlock(&omap_cpufreq_lock);
 }

 void omap_thermal_unthrottle(void)
 {
 	unsigned int cur;

 	if (!omap_cpufreq_ready)
 		return;

 	mutex_lock(&omap_cpufreq_lock);

 	if (max_thermal == max_freq) {
 		pr_warn("%s: not throttling\n", __func__);
 		goto out;
 	}

 	max_thermal = max_freq;

 	pr_warn("%s: temperature reduced, ending cpu throttling\n", __func__);

 	if (!omap_cpufreq_suspended) {
 		cur = omap_getspeed(0);
 		omap_cpufreq_scale(current_target_freq, cur);
 	}

 out:
 	mutex_unlock(&omap_cpufreq_lock);
 }

 static int omap_verify_speed(struct cpufreq_policy *policy)
 {
 	if (!freq_table)
 		return -EINVAL;
 	return cpufreq_frequency_table_verify(policy, freq_table);
 }

 static int omap_target(struct cpufreq_policy *policy,
 		       unsigned int target_freq,
 		       unsigned int relation)
 {
 	unsigned int i;
 	int ret = 0;

 	if (!freq_table) {
 		dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__,
 				policy->cpu);
 		return -EINVAL;
 	}

 	ret = cpufreq_frequency_table_target(policy, freq_table, target_freq,
 			relation, &i);
 	if (ret) {
 		dev_dbg(mpu_dev, "%s: cpu%d: no freq match for %d(ret=%d)\n",
 			__func__, policy->cpu, target_freq, ret);
 		return ret;
 	}

 	mutex_lock(&omap_cpufreq_lock);

 	current_target_freq = freq_table[i].frequency;

 	if (!omap_cpufreq_suspended)
 		ret = omap_cpufreq_scale(current_target_freq, policy->cur);


 	mutex_unlock(&omap_cpufreq_lock);

 	return ret;
 }

 static void omap_cpu_early_suspend(struct early_suspend *h)
 {
 	unsigned int cur;

 	mutex_lock(&omap_cpufreq_lock);

 	if (screen_off_max_freq) {
 		max_capped = screen_off_max_freq;

 		cur = omap_getspeed(0);
 		if (cur > max_capped)
 			omap_cpufreq_scale(max_capped, cur);
 	}

 	mutex_unlock(&omap_cpufreq_lock);
 }

 static void omap_cpu_late_resume(struct early_suspend *h)
 {
 	unsigned int cur;

 	mutex_lock(&omap_cpufreq_lock);

 	if (max_capped) {
 		max_capped = 0;

 		cur = omap_getspeed(0);
 		if (cur != current_target_freq)
 			omap_cpufreq_scale(current_target_freq, cur);
 	}

 	mutex_unlock(&omap_cpufreq_lock);
 }

 static struct early_suspend omap_cpu_early_suspend_handler = {
 	.level = EARLY_SUSPEND_LEVEL_BLANK_SCREEN,
 	.suspend = omap_cpu_early_suspend,
 	.resume = omap_cpu_late_resume,
 };

 static inline void freq_table_free(void)
 {
 	if (atomic_dec_and_test(&freq_table_users))
 		opp_free_cpufreq_table(mpu_dev, &freq_table);
 }

 static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
 {
 	int result = 0;
 	int i;

 	mpu_clk = clk_get(NULL, mpu_clk_name);
 	if (IS_ERR(mpu_clk))
 		return PTR_ERR(mpu_clk);

 	if (policy->cpu >= NR_CPUS) {
 		result = -EINVAL;
 		goto fail_ck;
 	}

 	policy->cur = policy->min = policy->max = omap_getspeed(policy->cpu);

 	if (atomic_inc_return(&freq_table_users) == 1)
 		result = opp_init_cpufreq_table(mpu_dev, &freq_table);

 	if (result) {
 		dev_err(mpu_dev, "%s: cpu%d: failed creating freq table[%d]\n",
 				__func__, policy->cpu, result);
 		goto fail_ck;
 	}

 	result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
 	if (result)
 		goto fail_table;

 	cpufreq_frequency_table_get_attr(freq_table, policy->cpu);

 	policy->min = policy->cpuinfo.min_freq;
 	policy->max = policy->cpuinfo.max_freq;
 	policy->cur = omap_getspeed(policy->cpu);

 	for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++)
 		max_freq = max(freq_table[i].frequency, max_freq);
 	max_thermal = max_freq;

 	/*
 	 * On OMAP SMP configuartion, both processors share the voltage
 	 * and clock. So both CPUs needs to be scaled together and hence
 	 * needs software co-ordination. Use cpufreq affected_cpus
 	 * interface to handle this scenario. Additional is_smp() check
 	 * is to keep SMP_ON_UP build working.
 	 */
 	if (is_smp()) {
 		policy->shared_type = CPUFREQ_SHARED_TYPE_ANY;
 		cpumask_setall(policy->cpus);
 	}

 	/* FIXME: what's the actual transition time? */
 	policy->cpuinfo.transition_latency = 300 * 1000;

 	return 0;

 fail_table:
 	freq_table_free();
 fail_ck:
 	clk_put(mpu_clk);
 	return result;
 }

 static int omap_cpu_exit(struct cpufreq_policy *policy)
 {
 	freq_table_free();
 	clk_put(mpu_clk);
 	return 0;
 }

 static ssize_t show_screen_off_freq(struct cpufreq_policy *policy, char *buf)
 {
 	return sprintf(buf, "%u\n", screen_off_max_freq);
 }

 static ssize_t store_screen_off_freq(struct cpufreq_policy *policy,
 	const char *buf, size_t count)
 {
 	unsigned int freq = 0;
 	int ret;
 	int index;

 	if (!freq_table)
 		return -EINVAL;

 	ret = sscanf(buf, "%u", &freq);
 	if (ret != 1)
 		return -EINVAL;

 	mutex_lock(&omap_cpufreq_lock);

 	ret = cpufreq_frequency_table_target(policy, freq_table, freq,
 		CPUFREQ_RELATION_H, &index);
 	if (ret)
 		goto out;

 	screen_off_max_freq = freq_table[index].frequency;

 	ret = count;

 out:
 	mutex_unlock(&omap_cpufreq_lock);
 	return ret;
 }

 struct freq_attr omap_cpufreq_attr_screen_off_freq = {
 	.attr = { .name = "screen_off_max_freq",
 		  .mode = 0644,
 		},
 	.show = show_screen_off_freq,
 	.store = store_screen_off_freq,
 };

 static struct freq_attr *omap_cpufreq_attr[] = {
 	&cpufreq_freq_attr_scaling_available_freqs,
 	&omap_cpufreq_attr_screen_off_freq,
 	NULL,
 };

 static struct cpufreq_driver omap_driver = {
 	.flags		= CPUFREQ_STICKY,
 	.verify		= omap_verify_speed,
 	.target		= omap_target,
 	.get		= omap_getspeed,
 	.init		= omap_cpu_init,
 	.exit		= omap_cpu_exit,
 	.name		= "omap2plus",
 	.attr		= omap_cpufreq_attr,
 };

 static int omap_cpufreq_suspend_noirq(struct device *dev)
 {
 	mutex_lock(&omap_cpufreq_lock);
 	omap_cpufreq_suspended = true;
 	mutex_unlock(&omap_cpufreq_lock);
 	return 0;
 }

 static int omap_cpufreq_resume_noirq(struct device *dev)
 {
 	unsigned int cur;

 	mutex_lock(&omap_cpufreq_lock);
 	cur = omap_getspeed(0);
 	if (cur != current_target_freq)
 		omap_cpufreq_scale(current_target_freq, cur);

 	omap_cpufreq_suspended = false;
 	mutex_unlock(&omap_cpufreq_lock);
 	return 0;
 }

 static struct dev_pm_ops omap_cpufreq_driver_pm_ops = {
 	.suspend_noirq = omap_cpufreq_suspend_noirq,
 	.resume_noirq = omap_cpufreq_resume_noirq,
 };

 static struct platform_driver omap_cpufreq_platform_driver = {
 	.driver.name = "omap_cpufreq",
 	.driver.pm = &omap_cpufreq_driver_pm_ops,
 };
 static struct platform_device omap_cpufreq_device = {
 	.name = "omap_cpufreq",
 };

 static int __init omap_cpufreq_init(void)
 {
 	int ret;

 	if (cpu_is_omap24xx())
 		mpu_clk_name = "virt_prcm_set";
 	else if (cpu_is_omap34xx())
 		mpu_clk_name = "dpll1_ck";
 	else if (cpu_is_omap443x())
 		mpu_clk_name = "dpll_mpu_ck";
 	else if (cpu_is_omap446x())
 		mpu_clk_name = "virt_dpll_mpu_ck";

 	if (!mpu_clk_name) {
 		pr_err("%s: unsupported Silicon?\n", __func__);
 		return -EINVAL;
 	}

 	mpu_dev = omap2_get_mpuss_device();
 	if (!mpu_dev) {
 		pr_warning("%s: unable to get the mpu device\n", __func__);
 		return -EINVAL;
 	}

 	register_early_suspend(&omap_cpu_early_suspend_handler);

 	ret = cpufreq_register_driver(&omap_driver);
 	omap_cpufreq_ready = !ret;

 	if (!ret) {
 		int t;

 		t = platform_device_register(&omap_cpufreq_device);
 		if (t)
 			pr_warn("%s_init: platform_device_register failed\n",
 				__func__);
 		t = platform_driver_register(&omap_cpufreq_platform_driver);
 		if (t)
 			pr_warn("%s_init: platform_driver_register failed\n",
 				__func__);
 	}

 	return ret;
 }

 static void __exit omap_cpufreq_exit(void)
 {
 	cpufreq_unregister_driver(&omap_driver);

 	unregister_early_suspend(&omap_cpu_early_suspend_handler);
 	platform_driver_unregister(&omap_cpufreq_platform_driver);
 	platform_device_unregister(&omap_cpufreq_device);
 }

 MODULE_DESCRIPTION("cpufreq driver for OMAP2PLUS SOCs");
 MODULE_LICENSE("GPL");
 late_initcall(omap_cpufreq_init);
 module_exit(omap_cpufreq_exit);
	/*
	* OMAP2PLUS cpufreq driver
	*
	* CPU frequency scaling for OMAP using OPP information
	*
	* Copyright (C) 2005 Nokia Corporation
	* Written by Tony Lindgren <[email protected]>
	*
	* Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
	*
	* Copyright (C) 2007-2011 Texas Instruments, Inc.
	* Updated to support OMAP3
	* Rajendra Nayak <[email protected]>
	*
	* 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/types.h>
	#include <linux/kernel.h>
	#include <linux/sched.h>
	#include <linux/cpufreq.h>
	#include <linux/delay.h>
	#include <linux/init.h>
	#include <linux/err.h>
	#include <linux/clk.h>
	#include <linux/io.h>
	#include <linux/opp.h>
	#include <linux/cpu.h>
	#include <linux/earlysuspend.h>
	#include <linux/platform_device.h>

	#include <asm/system.h>
	#include <asm/smp_plat.h>
	#include <asm/cpu.h>

	#include <plat/clock.h>
	#include <plat/omap-pm.h>
	#include <plat/common.h>

	#include <mach/hardware.h>

	#include "dvfs.h"

	#ifdef CONFIG_SMP
	struct lpj_info {
	unsigned long ref;
	unsigned int freq;
	};

	static DEFINE_PER_CPU(struct lpj_info, lpj_ref);
	static struct lpj_info global_lpj_ref;
	#endif

	static struct cpufreq_frequency_table *freq_table;
	static atomic_t freq_table_users = ATOMIC_INIT(0);
	static struct clk *mpu_clk;
	static char *mpu_clk_name;
	static struct device *mpu_dev;
	static DEFINE_MUTEX(omap_cpufreq_lock);

	static unsigned int max_thermal;
	static unsigned int max_capped;
	static unsigned int max_freq;
	static unsigned int current_target_freq;
	static unsigned int screen_off_max_freq;
	static bool omap_cpufreq_ready;
	static bool omap_cpufreq_suspended;

	static unsigned int omap_getspeed(unsigned int cpu)
	{
	unsigned long rate;

	if (cpu >= NR_CPUS)
	return 0;

	rate = clk_get_rate(mpu_clk) / 1000;
	return rate;
	}

	static int omap_cpufreq_scale(unsigned int target_freq, unsigned int cur_freq)
	{
	unsigned int i;
	int ret;
	struct cpufreq_freqs freqs;

	freqs.new = target_freq;
	freqs.old = omap_getspeed(0);

	/*
	* If the new frequency is more than the thermal max allowed
	* frequency, go ahead and scale the mpu device to proper frequency.
	*/
	if (freqs.new > max_thermal)
	freqs.new = max_thermal;

	if (max_capped && freqs.new > max_capped)
	freqs.new = max_capped;

	if ((freqs.old == freqs.new) && (cur_freq = freqs.new))
	return 0;

	get_online_cpus();

	/* notifiers */
	for_each_online_cpu(freqs.cpu)
	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

	#ifdef CONFIG_CPU_FREQ_DEBUG
	pr_info("cpufreq-omap: transition: %u --> %u\n", freqs.old, freqs.new);
	#endif

	ret = omap_device_scale(mpu_dev, mpu_dev, freqs.new * 1000);

	freqs.new = omap_getspeed(0);

	#ifdef CONFIG_SMP
	/*
	* Note that loops_per_jiffy is not updated on SMP systems in
	* cpufreq driver. So, update the per-CPU loops_per_jiffy value
	* on frequency transition. We need to update all dependent CPUs.
	*/
	for_each_possible_cpu(i) {
	struct lpj_info *lpj = &per_cpu(lpj_ref, i);
	if (!lpj->freq) {
	lpj->ref = per_cpu(cpu_data, i).loops_per_jiffy;
	lpj->freq = freqs.old;
	}

	per_cpu(cpu_data, i).loops_per_jiffy =
	cpufreq_scale(lpj->ref, lpj->freq, freqs.new);
	}

	/* And don't forget to adjust the global one */
	if (!global_lpj_ref.freq) {
	global_lpj_ref.ref = loops_per_jiffy;
	global_lpj_ref.freq = freqs.old;
	}
	loops_per_jiffy = cpufreq_scale(global_lpj_ref.ref, global_lpj_ref.freq,
	freqs.new);
	#endif

	/* notifiers */
	for_each_online_cpu(freqs.cpu)
	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

	put_online_cpus();

	return ret;
	}

	static unsigned int omap_thermal_lower_speed(void)
	{
	unsigned int max = 0;
	unsigned int curr;
	int i;

	curr = max_thermal;

	for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++)
	if (freq_table[i].frequency > max &&
	freq_table[i].frequency < curr)
	max = freq_table[i].frequency;

	if (!max)
	return curr;

	return max;
	}

	void omap_thermal_throttle(void)
	{
	unsigned int cur;

	if (!omap_cpufreq_ready) {
	pr_warn_once("%s: Thermal throttle prior to CPUFREQ ready\n",
	__func__);
	return;
	}

	mutex_lock(&omap_cpufreq_lock);

	max_thermal = omap_thermal_lower_speed();

	pr_warn("%s: temperature too high, cpu throttle at max %u\n",
	__func__, max_thermal);

	if (!omap_cpufreq_suspended) {
	cur = omap_getspeed(0);
	if (cur > max_thermal)
	omap_cpufreq_scale(max_thermal, cur);
	}

	mutex_unlock(&omap_cpufreq_lock);
	}

	void omap_thermal_unthrottle(void)
	{
	unsigned int cur;

	if (!omap_cpufreq_ready)
	return;

	mutex_lock(&omap_cpufreq_lock);

	if (max_thermal == max_freq) {
	pr_warn("%s: not throttling\n", __func__);
	goto out;
	}

	max_thermal = max_freq;

	pr_warn("%s: temperature reduced, ending cpu throttling\n", __func__);

	if (!omap_cpufreq_suspended) {
	cur = omap_getspeed(0);
	omap_cpufreq_scale(current_target_freq, cur);
	}

	out:
	mutex_unlock(&omap_cpufreq_lock);
	}

	static int omap_verify_speed(struct cpufreq_policy *policy)
	{
	if (!freq_table)
	return -EINVAL;
	return cpufreq_frequency_table_verify(policy, freq_table);
	}

	static int omap_target(struct cpufreq_policy *policy,
	unsigned int target_freq,
	unsigned int relation)
	{
	unsigned int i;
	int ret = 0;

	if (!freq_table) {
	dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__,
	policy->cpu);
	return -EINVAL;
	}

	ret = cpufreq_frequency_table_target(policy, freq_table, target_freq,
	relation, &i);
	if (ret) {
	dev_dbg(mpu_dev, "%s: cpu%d: no freq match for %d(ret=%d)\n",
	__func__, policy->cpu, target_freq, ret);
	return ret;
	}

	mutex_lock(&omap_cpufreq_lock);

	current_target_freq = freq_table[i].frequency;

	if (!omap_cpufreq_suspended)
	ret = omap_cpufreq_scale(current_target_freq, policy->cur);


	mutex_unlock(&omap_cpufreq_lock);

	return ret;
	}

	static void omap_cpu_early_suspend(struct early_suspend *h)
	{
	unsigned int cur;

	mutex_lock(&omap_cpufreq_lock);

	if (screen_off_max_freq) {
	max_capped = screen_off_max_freq;

	cur = omap_getspeed(0);
	if (cur > max_capped)
	omap_cpufreq_scale(max_capped, cur);
	}

	mutex_unlock(&omap_cpufreq_lock);
	}

	static void omap_cpu_late_resume(struct early_suspend *h)
	{
	unsigned int cur;

	mutex_lock(&omap_cpufreq_lock);

	if (max_capped) {
	max_capped = 0;

	cur = omap_getspeed(0);
	if (cur != current_target_freq)
	omap_cpufreq_scale(current_target_freq, cur);
	}

	mutex_unlock(&omap_cpufreq_lock);
	}

	static struct early_suspend omap_cpu_early_suspend_handler = {
	.level = EARLY_SUSPEND_LEVEL_BLANK_SCREEN,
	.suspend = omap_cpu_early_suspend,
	.resume = omap_cpu_late_resume,
	};

	static inline void freq_table_free(void)
	{
	if (atomic_dec_and_test(&freq_table_users))
	opp_free_cpufreq_table(mpu_dev, &freq_table);
	}

	static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
	{
	int result = 0;
	int i;

	mpu_clk = clk_get(NULL, mpu_clk_name);
	if (IS_ERR(mpu_clk))
	return PTR_ERR(mpu_clk);

	if (policy->cpu >= NR_CPUS) {
	result = -EINVAL;
	goto fail_ck;
	}

	policy->cur = policy->min = policy->max = omap_getspeed(policy->cpu);

	if (atomic_inc_return(&freq_table_users) == 1)
	result = opp_init_cpufreq_table(mpu_dev, &freq_table);

	if (result) {
	dev_err(mpu_dev, "%s: cpu%d: failed creating freq table[%d]\n",
	__func__, policy->cpu, result);
	goto fail_ck;
	}

	result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
	if (result)
	goto fail_table;

	cpufreq_frequency_table_get_attr(freq_table, policy->cpu);

	policy->min = policy->cpuinfo.min_freq;
	policy->max = policy->cpuinfo.max_freq;
	policy->cur = omap_getspeed(policy->cpu);

	for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++)
	max_freq = max(freq_table[i].frequency, max_freq);
	max_thermal = max_freq;

	/*
	* On OMAP SMP configuartion, both processors share the voltage
	* and clock. So both CPUs needs to be scaled together and hence
	* needs software co-ordination. Use cpufreq affected_cpus
	* interface to handle this scenario. Additional is_smp() check
	* is to keep SMP_ON_UP build working.
	*/
	if (is_smp()) {
	policy->shared_type = CPUFREQ_SHARED_TYPE_ANY;
	cpumask_setall(policy->cpus);
	}

	/* FIXME: what's the actual transition time? */
	policy->cpuinfo.transition_latency = 300 * 1000;

	return 0;

	fail_table:
	freq_table_free();
	fail_ck:
	clk_put(mpu_clk);
	return result;
	}

	static int omap_cpu_exit(struct cpufreq_policy *policy)
	{
	freq_table_free();
	clk_put(mpu_clk);
	return 0;
	}

	static ssize_t show_screen_off_freq(struct cpufreq_policy policy, char buf)
	{
	return sprintf(buf, "%u\n", screen_off_max_freq);
	}

	static ssize_t store_screen_off_freq(struct cpufreq_policy *policy,
	const char *buf, size_t count)
	{
	unsigned int freq = 0;
	int ret;
	int index;

	if (!freq_table)
	return -EINVAL;

	ret = sscanf(buf, "%u", &freq);
	if (ret != 1)
	return -EINVAL;

	mutex_lock(&omap_cpufreq_lock);

	ret = cpufreq_frequency_table_target(policy, freq_table, freq,
	CPUFREQ_RELATION_H, &index);
	if (ret)
	goto out;

	screen_off_max_freq = freq_table[index].frequency;

	ret = count;

	out:
	mutex_unlock(&omap_cpufreq_lock);
	return ret;
	}

	struct freq_attr omap_cpufreq_attr_screen_off_freq = {
	.attr = { .name = "screen_off_max_freq",
	.mode = 0644,
	},
	.show = show_screen_off_freq,
	.store = store_screen_off_freq,
	};

	static struct freq_attr *omap_cpufreq_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	&omap_cpufreq_attr_screen_off_freq,
	NULL,
	};

	static struct cpufreq_driver omap_driver = {
	.flags = CPUFREQ_STICKY,
	.verify = omap_verify_speed,
	.target = omap_target,
	.get = omap_getspeed,
	.init = omap_cpu_init,
	.exit = omap_cpu_exit,
	.name = "omap2plus",
	.attr = omap_cpufreq_attr,
	};

	static int omap_cpufreq_suspend_noirq(struct device *dev)
	{
	mutex_lock(&omap_cpufreq_lock);
	omap_cpufreq_suspended = true;
	mutex_unlock(&omap_cpufreq_lock);
	return 0;
	}

	static int omap_cpufreq_resume_noirq(struct device *dev)
	{
	unsigned int cur;

	mutex_lock(&omap_cpufreq_lock);
	cur = omap_getspeed(0);
	if (cur != current_target_freq)
	omap_cpufreq_scale(current_target_freq, cur);

	omap_cpufreq_suspended = false;
	mutex_unlock(&omap_cpufreq_lock);
	return 0;
	}

	static struct dev_pm_ops omap_cpufreq_driver_pm_ops = {
	.suspend_noirq = omap_cpufreq_suspend_noirq,
	.resume_noirq = omap_cpufreq_resume_noirq,
	};

	static struct platform_driver omap_cpufreq_platform_driver = {
	.driver.name = "omap_cpufreq",
	.driver.pm = &omap_cpufreq_driver_pm_ops,
	};
	static struct platform_device omap_cpufreq_device = {
	.name = "omap_cpufreq",
	};

	static int __init omap_cpufreq_init(void)
	{
	int ret;

	if (cpu_is_omap24xx())
	mpu_clk_name = "virt_prcm_set";
	else if (cpu_is_omap34xx())
	mpu_clk_name = "dpll1_ck";
	else if (cpu_is_omap443x())
	mpu_clk_name = "dpll_mpu_ck";
	else if (cpu_is_omap446x())
	mpu_clk_name = "virt_dpll_mpu_ck";

	if (!mpu_clk_name) {
	pr_err("%s: unsupported Silicon?\n", __func__);
	return -EINVAL;
	}

	mpu_dev = omap2_get_mpuss_device();
	if (!mpu_dev) {
	pr_warning("%s: unable to get the mpu device\n", __func__);
	return -EINVAL;
	}

	register_early_suspend(&omap_cpu_early_suspend_handler);

	ret = cpufreq_register_driver(&omap_driver);
	omap_cpufreq_ready = !ret;

	if (!ret) {
	int t;

	t = platform_device_register(&omap_cpufreq_device);
	if (t)
	pr_warn("%s_init: platform_device_register failed\n",
	__func__);
	t = platform_driver_register(&omap_cpufreq_platform_driver);
	if (t)
	pr_warn("%s_init: platform_driver_register failed\n",
	__func__);
	}

	return ret;
	}

	static void __exit omap_cpufreq_exit(void)
	{
	cpufreq_unregister_driver(&omap_driver);

	unregister_early_suspend(&omap_cpu_early_suspend_handler);
	platform_driver_unregister(&omap_cpufreq_platform_driver);
	platform_device_unregister(&omap_cpufreq_device);
	}

	MODULE_DESCRIPTION("cpufreq driver for OMAP2PLUS SOCs");
	MODULE_LICENSE("GPL");
	late_initcall(omap_cpufreq_init);
	module_exit(omap_cpufreq_exit);