drivers/cpufreq/tegra-cpufreq.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright (C) 2010 Google, Inc.
  *
  * Author:
  *	Colin Cross <ccross@google.com>
  *	Based on arch/arm/plat-omap/cpu-omap.c, (C) 2005 Nokia Corporation
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/types.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/suspend.h>

 static struct cpufreq_frequency_table freq_table[] = {
 	{ .frequency = 216000 },
 	{ .frequency = 312000 },
 	{ .frequency = 456000 },
 	{ .frequency = 608000 },
 	{ .frequency = 760000 },
 	{ .frequency = 816000 },
 	{ .frequency = 912000 },
 	{ .frequency = 1000000 },
 	{ .frequency = CPUFREQ_TABLE_END },
 };

 #define NUM_CPUS	2

 static struct clk *cpu_clk;
 static struct clk *pll_x_clk;
 static struct clk *pll_p_clk;
 static struct clk *emc_clk;

 static unsigned long target_cpu_speed[NUM_CPUS];
 static DEFINE_MUTEX(tegra_cpu_lock);
 static bool is_suspended;

 static int tegra_verify_speed(struct cpufreq_policy *policy)
 {
 	return cpufreq_frequency_table_verify(policy, freq_table);
 }

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

 	if (cpu >= NUM_CPUS)
 		return 0;

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

 static int tegra_cpu_clk_set_rate(unsigned long rate)
 {
 	int ret;

 	/*
 	 * Take an extra reference to the main pll so it doesn't turn
 	 * off when we move the cpu off of it
 	 */
 	clk_prepare_enable(pll_x_clk);

 	ret = clk_set_parent(cpu_clk, pll_p_clk);
 	if (ret) {
 		pr_err("Failed to switch cpu to clock pll_p\n");
 		goto out;
 	}

 	if (rate == clk_get_rate(pll_p_clk))
 		goto out;

 	ret = clk_set_rate(pll_x_clk, rate);
 	if (ret) {
 		pr_err("Failed to change pll_x to %lu\n", rate);
 		goto out;
 	}

 	ret = clk_set_parent(cpu_clk, pll_x_clk);
 	if (ret) {
 		pr_err("Failed to switch cpu to clock pll_x\n");
 		goto out;
 	}

 out:
 	clk_disable_unprepare(pll_x_clk);
 	return ret;
 }

 static int tegra_update_cpu_speed(struct cpufreq_policy *policy,
 		unsigned long rate)
 {
 	int ret = 0;
 	struct cpufreq_freqs freqs;

 	freqs.old = tegra_getspeed(0);
 	freqs.new = rate;

 	if (freqs.old == freqs.new)
 		return ret;

 	/*
 	 * Vote on memory bus frequency based on cpu frequency
 	 * This sets the minimum frequency, display or avp may request higher
 	 */
 	if (rate >= 816000)
 		clk_set_rate(emc_clk, 600000000); /* cpu 816 MHz, emc max */
 	else if (rate >= 456000)
 		clk_set_rate(emc_clk, 300000000); /* cpu 456 MHz, emc 150Mhz */
 	else
 		clk_set_rate(emc_clk, 100000000);  /* emc 50Mhz */

 	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);

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

 	ret = tegra_cpu_clk_set_rate(freqs.new * 1000);
 	if (ret) {
 		pr_err("cpu-tegra: Failed to set cpu frequency to %d kHz\n",
 			freqs.new);
 		return ret;
 	}

 	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);

 	return 0;
 }

 static unsigned long tegra_cpu_highest_speed(void)
 {
 	unsigned long rate = 0;
 	int i;

 	for_each_online_cpu(i)
 		rate = max(rate, target_cpu_speed[i]);
 	return rate;
 }

 static int tegra_target(struct cpufreq_policy *policy,
 		       unsigned int target_freq,
 		       unsigned int relation)
 {
 	unsigned int idx;
 	unsigned int freq;
 	int ret = 0;

 	mutex_lock(&tegra_cpu_lock);

 	if (is_suspended) {
 		ret = -EBUSY;
 		goto out;
 	}

 	cpufreq_frequency_table_target(policy, freq_table, target_freq,
 		relation, &idx);

 	freq = freq_table[idx].frequency;

 	target_cpu_speed[policy->cpu] = freq;

 	ret = tegra_update_cpu_speed(policy, tegra_cpu_highest_speed());

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

 static int tegra_pm_notify(struct notifier_block *nb, unsigned long event,
 	void *dummy)
 {
 	mutex_lock(&tegra_cpu_lock);
 	if (event == PM_SUSPEND_PREPARE) {
 		struct cpufreq_policy *policy = cpufreq_cpu_get(0);
 		is_suspended = true;
 		pr_info("Tegra cpufreq suspend: setting frequency to %d kHz\n",
 			freq_table[0].frequency);
 		tegra_update_cpu_speed(policy, freq_table[0].frequency);
 		cpufreq_cpu_put(policy);
 	} else if (event == PM_POST_SUSPEND) {
 		is_suspended = false;
 	}
 	mutex_unlock(&tegra_cpu_lock);

 	return NOTIFY_OK;
 }

 static struct notifier_block tegra_cpu_pm_notifier = {
 	.notifier_call = tegra_pm_notify,
 };

 static int tegra_cpu_init(struct cpufreq_policy *policy)
 {
 	if (policy->cpu >= NUM_CPUS)
 		return -EINVAL;

 	clk_prepare_enable(emc_clk);
 	clk_prepare_enable(cpu_clk);

 	cpufreq_frequency_table_cpuinfo(policy, freq_table);
 	cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
 	policy->cur = tegra_getspeed(policy->cpu);
 	target_cpu_speed[policy->cpu] = policy->cur;

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

 	cpumask_copy(policy->cpus, cpu_possible_mask);

 	if (policy->cpu == 0)
 		register_pm_notifier(&tegra_cpu_pm_notifier);

 	return 0;
 }

 static int tegra_cpu_exit(struct cpufreq_policy *policy)
 {
 	cpufreq_frequency_table_cpuinfo(policy, freq_table);
 	clk_disable_unprepare(emc_clk);
 	return 0;
 }

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

 static struct cpufreq_driver tegra_cpufreq_driver = {
 	.verify		= tegra_verify_speed,
 	.target		= tegra_target,
 	.get		= tegra_getspeed,
 	.init		= tegra_cpu_init,
 	.exit		= tegra_cpu_exit,
 	.name		= "tegra",
 	.attr		= tegra_cpufreq_attr,
 };

 static int __init tegra_cpufreq_init(void)
 {
 	cpu_clk = clk_get_sys(NULL, "cpu");
 	if (IS_ERR(cpu_clk))
 		return PTR_ERR(cpu_clk);

 	pll_x_clk = clk_get_sys(NULL, "pll_x");
 	if (IS_ERR(pll_x_clk))
 		return PTR_ERR(pll_x_clk);

 	pll_p_clk = clk_get_sys(NULL, "pll_p_cclk");
 	if (IS_ERR(pll_p_clk))
 		return PTR_ERR(pll_p_clk);

 	emc_clk = clk_get_sys("cpu", "emc");
 	if (IS_ERR(emc_clk)) {
 		clk_put(cpu_clk);
 		return PTR_ERR(emc_clk);
 	}

 	return cpufreq_register_driver(&tegra_cpufreq_driver);
 }

 static void __exit tegra_cpufreq_exit(void)
 {
         cpufreq_unregister_driver(&tegra_cpufreq_driver);
 	clk_put(emc_clk);
 	clk_put(cpu_clk);
 }


 MODULE_AUTHOR("Colin Cross <ccross@android.com>");
 MODULE_DESCRIPTION("cpufreq driver for Nvidia Tegra2");
 MODULE_LICENSE("GPL");
 module_init(tegra_cpufreq_init);
 module_exit(tegra_cpufreq_exit);
	/*
	* Copyright (C) 2010 Google, Inc.
	*
	* Author:
	* Colin Cross <ccross@google.com>
	* Based on arch/arm/plat-omap/cpu-omap.c, (C) 2005 Nokia Corporation
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/types.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/suspend.h>

	static struct cpufreq_frequency_table freq_table[] = {
	{ .frequency = 216000 },
	{ .frequency = 312000 },
	{ .frequency = 456000 },
	{ .frequency = 608000 },
	{ .frequency = 760000 },
	{ .frequency = 816000 },
	{ .frequency = 912000 },
	{ .frequency = 1000000 },
	{ .frequency = CPUFREQ_TABLE_END },
	};

	#define NUM_CPUS 2

	static struct clk *cpu_clk;
	static struct clk *pll_x_clk;
	static struct clk *pll_p_clk;
	static struct clk *emc_clk;

	static unsigned long target_cpu_speed[NUM_CPUS];
	static DEFINE_MUTEX(tegra_cpu_lock);
	static bool is_suspended;

	static int tegra_verify_speed(struct cpufreq_policy *policy)
	{
	return cpufreq_frequency_table_verify(policy, freq_table);
	}

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

	if (cpu >= NUM_CPUS)
	return 0;

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

	static int tegra_cpu_clk_set_rate(unsigned long rate)
	{
	int ret;

	/*
	* Take an extra reference to the main pll so it doesn't turn
	* off when we move the cpu off of it
	*/
	clk_prepare_enable(pll_x_clk);

	ret = clk_set_parent(cpu_clk, pll_p_clk);
	if (ret) {
	pr_err("Failed to switch cpu to clock pll_p\n");
	goto out;
	}

	if (rate == clk_get_rate(pll_p_clk))
	goto out;

	ret = clk_set_rate(pll_x_clk, rate);
	if (ret) {
	pr_err("Failed to change pll_x to %lu\n", rate);
	goto out;
	}

	ret = clk_set_parent(cpu_clk, pll_x_clk);
	if (ret) {
	pr_err("Failed to switch cpu to clock pll_x\n");
	goto out;
	}

	out:
	clk_disable_unprepare(pll_x_clk);
	return ret;
	}

	static int tegra_update_cpu_speed(struct cpufreq_policy *policy,
	unsigned long rate)
	{
	int ret = 0;
	struct cpufreq_freqs freqs;

	freqs.old = tegra_getspeed(0);
	freqs.new = rate;

	if (freqs.old == freqs.new)
	return ret;

	/*
	* Vote on memory bus frequency based on cpu frequency
	* This sets the minimum frequency, display or avp may request higher
	*/
	if (rate >= 816000)
	clk_set_rate(emc_clk, 600000000); /* cpu 816 MHz, emc max */
	else if (rate >= 456000)
	clk_set_rate(emc_clk, 300000000); /* cpu 456 MHz, emc 150Mhz */
	else
	clk_set_rate(emc_clk, 100000000); /* emc 50Mhz */

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);

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

	ret = tegra_cpu_clk_set_rate(freqs.new * 1000);
	if (ret) {
	pr_err("cpu-tegra: Failed to set cpu frequency to %d kHz\n",
	freqs.new);
	return ret;
	}

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);

	return 0;
	}

	static unsigned long tegra_cpu_highest_speed(void)
	{
	unsigned long rate = 0;
	int i;

	for_each_online_cpu(i)
	rate = max(rate, target_cpu_speed[i]);
	return rate;
	}

	static int tegra_target(struct cpufreq_policy *policy,
	unsigned int target_freq,
	unsigned int relation)
	{
	unsigned int idx;
	unsigned int freq;
	int ret = 0;

	mutex_lock(&tegra_cpu_lock);

	if (is_suspended) {
	ret = -EBUSY;
	goto out;
	}

	cpufreq_frequency_table_target(policy, freq_table, target_freq,
	relation, &idx);

	freq = freq_table[idx].frequency;

	target_cpu_speed[policy->cpu] = freq;

	ret = tegra_update_cpu_speed(policy, tegra_cpu_highest_speed());

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

	static int tegra_pm_notify(struct notifier_block *nb, unsigned long event,
	void *dummy)
	{
	mutex_lock(&tegra_cpu_lock);
	if (event == PM_SUSPEND_PREPARE) {
	struct cpufreq_policy *policy = cpufreq_cpu_get(0);
	is_suspended = true;
	pr_info("Tegra cpufreq suspend: setting frequency to %d kHz\n",
	freq_table[0].frequency);
	tegra_update_cpu_speed(policy, freq_table[0].frequency);
	cpufreq_cpu_put(policy);
	} else if (event == PM_POST_SUSPEND) {
	is_suspended = false;
	}
	mutex_unlock(&tegra_cpu_lock);

	return NOTIFY_OK;
	}

	static struct notifier_block tegra_cpu_pm_notifier = {
	.notifier_call = tegra_pm_notify,
	};

	static int tegra_cpu_init(struct cpufreq_policy *policy)
	{
	if (policy->cpu >= NUM_CPUS)
	return -EINVAL;

	clk_prepare_enable(emc_clk);
	clk_prepare_enable(cpu_clk);

	cpufreq_frequency_table_cpuinfo(policy, freq_table);
	cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
	policy->cur = tegra_getspeed(policy->cpu);
	target_cpu_speed[policy->cpu] = policy->cur;

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

	cpumask_copy(policy->cpus, cpu_possible_mask);

	if (policy->cpu == 0)
	register_pm_notifier(&tegra_cpu_pm_notifier);

	return 0;
	}

	static int tegra_cpu_exit(struct cpufreq_policy *policy)
	{
	cpufreq_frequency_table_cpuinfo(policy, freq_table);
	clk_disable_unprepare(emc_clk);
	return 0;
	}

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

	static struct cpufreq_driver tegra_cpufreq_driver = {
	.verify = tegra_verify_speed,
	.target = tegra_target,
	.get = tegra_getspeed,
	.init = tegra_cpu_init,
	.exit = tegra_cpu_exit,
	.name = "tegra",
	.attr = tegra_cpufreq_attr,
	};

	static int __init tegra_cpufreq_init(void)
	{
	cpu_clk = clk_get_sys(NULL, "cpu");
	if (IS_ERR(cpu_clk))
	return PTR_ERR(cpu_clk);

	pll_x_clk = clk_get_sys(NULL, "pll_x");
	if (IS_ERR(pll_x_clk))
	return PTR_ERR(pll_x_clk);

	pll_p_clk = clk_get_sys(NULL, "pll_p_cclk");
	if (IS_ERR(pll_p_clk))
	return PTR_ERR(pll_p_clk);

	emc_clk = clk_get_sys("cpu", "emc");
	if (IS_ERR(emc_clk)) {
	clk_put(cpu_clk);
	return PTR_ERR(emc_clk);
	}

	return cpufreq_register_driver(&tegra_cpufreq_driver);
	}

	static void __exit tegra_cpufreq_exit(void)
	{
	cpufreq_unregister_driver(&tegra_cpufreq_driver);
	clk_put(emc_clk);
	clk_put(cpu_clk);
	}


	MODULE_AUTHOR("Colin Cross <ccross@android.com>");
	MODULE_DESCRIPTION("cpufreq driver for Nvidia Tegra2");
	MODULE_LICENSE("GPL");
	module_init(tegra_cpufreq_init);
	module_exit(tegra_cpufreq_exit);