drivers/cpufreq/omap-cpufreq.c - kernel/msm-5.4 - Gitiles

 /*
  *  CPU frequency scaling for OMAP using OPP information
  *
  *  Copyright (C) 2005 Nokia Corporation
  *  Written by Tony Lindgren <tony@atomide.com>
  *
  *  Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
  *
  * Copyright (C) 2007-2011 Texas Instruments, Inc.
  * - OMAP3/4 support by Rajendra Nayak, Santosh Shilimkar
  *
  * 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/module.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>

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

 /* OPP tolerance in percentage */
 #define	OPP_TOLERANCE	4

 static struct cpufreq_frequency_table *freq_table;
 static atomic_t freq_table_users = ATOMIC_INIT(0);
 static struct clk *mpu_clk;
 static struct device *mpu_dev;
 static struct regulator *mpu_reg;

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

 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_target(struct cpufreq_policy *policy,
 		       unsigned int target_freq,
 		       unsigned int relation)
 {
 	unsigned int i;
 	int r, ret = 0;
 	struct cpufreq_freqs freqs;
 	struct opp *opp;
 	unsigned long freq, volt = 0, volt_old = 0, tol = 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;
 	}
 	freqs.new = freq_table[i].frequency;
 	if (!freqs.new) {
 		dev_err(mpu_dev, "%s: cpu%d: no match for freq %d\n", __func__,
 			policy->cpu, target_freq);
 		return -EINVAL;
 	}

 	freqs.old = omap_getspeed(policy->cpu);

 	if (freqs.old == freqs.new && policy->cur == freqs.new)
 		return ret;

 	/* notifiers */
 	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);

 	freq = freqs.new * 1000;
 	ret = clk_round_rate(mpu_clk, freq);
 	if (IS_ERR_VALUE(ret)) {
 		dev_warn(mpu_dev,
 			 "CPUfreq: Cannot find matching frequency for %lu\n",
 			 freq);
 		return ret;
 	}
 	freq = ret;

 	if (mpu_reg) {
 		rcu_read_lock();
 		opp = opp_find_freq_ceil(mpu_dev, &freq);
 		if (IS_ERR(opp)) {
 			rcu_read_unlock();
 			dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
 				__func__, freqs.new);
 			return -EINVAL;
 		}
 		volt = opp_get_voltage(opp);
 		rcu_read_unlock();
 		tol = volt * OPP_TOLERANCE / 100;
 		volt_old = regulator_get_voltage(mpu_reg);
 	}

 	dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n",
 		freqs.old / 1000, volt_old ? volt_old / 1000 : -1,
 		freqs.new / 1000, volt ? volt / 1000 : -1);

 	/* scaling up?  scale voltage before frequency */
 	if (mpu_reg && (freqs.new > freqs.old)) {
 		r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
 		if (r < 0) {
 			dev_warn(mpu_dev, "%s: unable to scale voltage up.\n",
 				 __func__);
 			freqs.new = freqs.old;
 			goto done;
 		}
 	}

 	ret = clk_set_rate(mpu_clk, freqs.new * 1000);

 	/* scaling down?  scale voltage after frequency */
 	if (mpu_reg && (freqs.new < freqs.old)) {
 		r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
 		if (r < 0) {
 			dev_warn(mpu_dev, "%s: unable to scale voltage down.\n",
 				 __func__);
 			ret = clk_set_rate(mpu_clk, freqs.old * 1000);
 			freqs.new = freqs.old;
 			goto done;
 		}
 	}

 	freqs.new = omap_getspeed(policy->cpu);

 done:
 	/* notifiers */
 	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);

 	return ret;
 }

 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;

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

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

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

 	if (!freq_table)
 		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;
 	}

 	atomic_inc_return(&freq_table_users);

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

 	cpufreq_frequency_table_get_attr(freq_table, policy->cpu);

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

 	/*
 	 * 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())
 		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 struct freq_attr *omap_cpufreq_attr[] = {
 	&cpufreq_freq_attr_scaling_available_freqs,
 	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		= "omap",
 	.attr		= omap_cpufreq_attr,
 };

 static int omap_cpufreq_probe(struct platform_device *pdev)
 {
 	mpu_dev = get_cpu_device(0);
 	if (!mpu_dev) {
 		pr_warning("%s: unable to get the mpu device\n", __func__);
 		return -EINVAL;
 	}

 	mpu_reg = regulator_get(mpu_dev, "vcc");
 	if (IS_ERR(mpu_reg)) {
 		pr_warning("%s: unable to get MPU regulator\n", __func__);
 		mpu_reg = NULL;
 	} else {
 		/*
 		 * Ensure physical regulator is present.
 		 * (e.g. could be dummy regulator.)
 		 */
 		if (regulator_get_voltage(mpu_reg) < 0) {
 			pr_warn("%s: physical regulator not present for MPU\n",
 				__func__);
 			regulator_put(mpu_reg);
 			mpu_reg = NULL;
 		}
 	}

 	return cpufreq_register_driver(&omap_driver);
 }

 static int omap_cpufreq_remove(struct platform_device *pdev)
 {
 	return cpufreq_unregister_driver(&omap_driver);
 }

 static struct platform_driver omap_cpufreq_platdrv = {
 	.driver = {
 		.name	= "omap-cpufreq",
 		.owner	= THIS_MODULE,
 	},
 	.probe		= omap_cpufreq_probe,
 	.remove		= omap_cpufreq_remove,
 };
 module_platform_driver(omap_cpufreq_platdrv);

 MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
 MODULE_LICENSE("GPL");
	/*
	* CPU frequency scaling for OMAP using OPP information
	*
	* Copyright (C) 2005 Nokia Corporation
	* Written by Tony Lindgren <tony@atomide.com>
	*
	* Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
	*
	* Copyright (C) 2007-2011 Texas Instruments, Inc.
	* - OMAP3/4 support by Rajendra Nayak, Santosh Shilimkar
	*
	* 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/module.h>
	#include <linux/platform_device.h>
	#include <linux/regulator/consumer.h>

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

	/* OPP tolerance in percentage */
	#define OPP_TOLERANCE 4

	static struct cpufreq_frequency_table *freq_table;
	static atomic_t freq_table_users = ATOMIC_INIT(0);
	static struct clk *mpu_clk;
	static struct device *mpu_dev;
	static struct regulator *mpu_reg;

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

	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_target(struct cpufreq_policy *policy,
	unsigned int target_freq,
	unsigned int relation)
	{
	unsigned int i;
	int r, ret = 0;
	struct cpufreq_freqs freqs;
	struct opp *opp;
	unsigned long freq, volt = 0, volt_old = 0, tol = 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;
	}
	freqs.new = freq_table[i].frequency;
	if (!freqs.new) {
	dev_err(mpu_dev, "%s: cpu%d: no match for freq %d\n", __func__,
	policy->cpu, target_freq);
	return -EINVAL;
	}

	freqs.old = omap_getspeed(policy->cpu);

	if (freqs.old == freqs.new && policy->cur == freqs.new)
	return ret;

	/* notifiers */
	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);

	freq = freqs.new * 1000;
	ret = clk_round_rate(mpu_clk, freq);
	if (IS_ERR_VALUE(ret)) {
	dev_warn(mpu_dev,
	"CPUfreq: Cannot find matching frequency for %lu\n",
	freq);
	return ret;
	}
	freq = ret;

	if (mpu_reg) {
	rcu_read_lock();
	opp = opp_find_freq_ceil(mpu_dev, &freq);
	if (IS_ERR(opp)) {
	rcu_read_unlock();
	dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
	__func__, freqs.new);
	return -EINVAL;
	}
	volt = opp_get_voltage(opp);
	rcu_read_unlock();
	tol = volt * OPP_TOLERANCE / 100;
	volt_old = regulator_get_voltage(mpu_reg);
	}

	dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n",
	freqs.old / 1000, volt_old ? volt_old / 1000 : -1,
	freqs.new / 1000, volt ? volt / 1000 : -1);

	/* scaling up? scale voltage before frequency */
	if (mpu_reg && (freqs.new > freqs.old)) {
	r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
	if (r < 0) {
	dev_warn(mpu_dev, "%s: unable to scale voltage up.\n",
	__func__);
	freqs.new = freqs.old;
	goto done;
	}
	}

	ret = clk_set_rate(mpu_clk, freqs.new * 1000);

	/* scaling down? scale voltage after frequency */
	if (mpu_reg && (freqs.new < freqs.old)) {
	r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
	if (r < 0) {
	dev_warn(mpu_dev, "%s: unable to scale voltage down.\n",
	__func__);
	ret = clk_set_rate(mpu_clk, freqs.old * 1000);
	freqs.new = freqs.old;
	goto done;
	}
	}

	freqs.new = omap_getspeed(policy->cpu);

	done:
	/* notifiers */
	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);

	return ret;
	}

	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;

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

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

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

	if (!freq_table)
	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;
	}

	atomic_inc_return(&freq_table_users);

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

	cpufreq_frequency_table_get_attr(freq_table, policy->cpu);

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

	/*
	* 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())
	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 struct freq_attr *omap_cpufreq_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	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 = "omap",
	.attr = omap_cpufreq_attr,
	};

	static int omap_cpufreq_probe(struct platform_device *pdev)
	{
	mpu_dev = get_cpu_device(0);
	if (!mpu_dev) {
	pr_warning("%s: unable to get the mpu device\n", __func__);
	return -EINVAL;
	}

	mpu_reg = regulator_get(mpu_dev, "vcc");
	if (IS_ERR(mpu_reg)) {
	pr_warning("%s: unable to get MPU regulator\n", __func__);
	mpu_reg = NULL;
	} else {
	/*
	* Ensure physical regulator is present.
	* (e.g. could be dummy regulator.)
	*/
	if (regulator_get_voltage(mpu_reg) < 0) {
	pr_warn("%s: physical regulator not present for MPU\n",
	__func__);
	regulator_put(mpu_reg);
	mpu_reg = NULL;
	}
	}

	return cpufreq_register_driver(&omap_driver);
	}

	static int omap_cpufreq_remove(struct platform_device *pdev)
	{
	return cpufreq_unregister_driver(&omap_driver);
	}

	static struct platform_driver omap_cpufreq_platdrv = {
	.driver = {
	.name = "omap-cpufreq",
	.owner = THIS_MODULE,
	},
	.probe = omap_cpufreq_probe,
	.remove = omap_cpufreq_remove,
	};
	module_platform_driver(omap_cpufreq_platdrv);

	MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
	MODULE_LICENSE("GPL");