[linux-2.6-block.git] / arch / arm / mach-tegra / cpu-tegra.c

/*
 * arch/arm/mach-tegra/cpu-tegra.c
 *
 * 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>

#include <asm/system.h>

#include <mach/hardware.h>
#include <mach/clk.h>

/* Frequency table index must be sequential starting at 0 */
static struct cpufreq_frequency_table freq_table[] = {
	{ 0, 216000 },
	{ 1, 312000 },
	{ 2, 456000 },
	{ 3, 608000 },
	{ 4, 760000 },
	{ 5, 816000 },
	{ 6, 912000 },
	{ 7, 1000000 },
	{ 8, CPUFREQ_TABLE_END },
};

#define NUM_CPUS	2

static struct clk *cpu_clk;

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

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

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_update_cpu_speed(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;

	for_each_online_cpu(freqs.cpu)
		cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

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

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

	for_each_online_cpu(freqs.cpu)
		cpufreq_notify_transition(&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)
{
	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(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) {
		is_suspended = true;
		pr_info("Tegra cpufreq suspend: setting frequency to %d kHz\n",
			freq_table[0].frequency);
		tegra_update_cpu_speed(freq_table[0].frequency);
	} 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;

	cpu_clk = clk_get_sys(NULL, "cpu");
	if (IS_ERR(cpu_clk))
		return PTR_ERR(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;

	policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
	cpumask_copy(policy->related_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_put(cpu_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)
{
	return cpufreq_register_driver(&tegra_cpufreq_driver);
}

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


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);
Commit	Line	Data
7056d423 CC	1	/*
	2	* arch/arm/mach-tegra/cpu-tegra.c
	3	*
	4	* Copyright (C) 2010 Google, Inc.
	5	*
	6	* Author:
	7	* Colin Cross <ccross@google.com>
	8	* Based on arch/arm/plat-omap/cpu-omap.c, (C) 2005 Nokia Corporation
	9	*
	10	* This software is licensed under the terms of the GNU General Public
	11	* License version 2, as published by the Free Software Foundation, and
	12	* may be copied, distributed, and modified under those terms.
	13	*
	14	* This program is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
	18	*
	19	*/
	20
	21	#include <linux/kernel.h>
	22	#include <linux/module.h>
	23	#include <linux/types.h>
	24	#include <linux/sched.h>
	25	#include <linux/cpufreq.h>
	26	#include <linux/delay.h>
	27	#include <linux/init.h>
	28	#include <linux/err.h>
	29	#include <linux/clk.h>
	30	#include <linux/io.h>
1eb2ecf1	31	#include <linux/suspend.h>
7056d423 CC	32
	33	#include <asm/system.h>
	34
	35	#include <mach/hardware.h>
	36	#include <mach/clk.h>
	37
	38	/* Frequency table index must be sequential starting at 0 */
	39	static struct cpufreq_frequency_table freq_table[] = {
1eb2ecf1 CC	40	{ 0, 216000 },
	41	{ 1, 312000 },
	42	{ 2, 456000 },
	43	{ 3, 608000 },
	44	{ 4, 760000 },
	45	{ 5, 816000 },
	46	{ 6, 912000 },
	47	{ 7, 1000000 },
	48	{ 8, CPUFREQ_TABLE_END },
7056d423 CC	49	};
	50
	51	#define NUM_CPUS 2
	52
	53	static struct clk *cpu_clk;
	54
	55	static unsigned long target_cpu_speed[NUM_CPUS];
1eb2ecf1 CC	56	static DEFINE_MUTEX(tegra_cpu_lock);
1eb2ecf1 CC	57	static bool is_suspended;
7056d423 CC	58
	59	int tegra_verify_speed(struct cpufreq_policy *policy)
	60	{
	61	return cpufreq_frequency_table_verify(policy, freq_table);
	62	}
	63
	64	unsigned int tegra_getspeed(unsigned int cpu)
	65	{
	66	unsigned long rate;
	67
	68	if (cpu >= NUM_CPUS)
	69	return 0;
	70
	71	rate = clk_get_rate(cpu_clk) / 1000;
	72	return rate;
	73	}
	74
1eb2ecf1	75	static int tegra_update_cpu_speed(unsigned long rate)
7056d423	76	{
7056d423 CC	77	int ret = 0;
	78	struct cpufreq_freqs freqs;
	79
7056d423 CC	80	freqs.old = tegra_getspeed(0);
	81	freqs.new = rate;
	82
	83	if (freqs.old == freqs.new)
	84	return ret;
	85
	86	for_each_online_cpu(freqs.cpu)
	87	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	88
	89	#ifdef CONFIG_CPU_FREQ_DEBUG
	90	printk(KERN_DEBUG "cpufreq-tegra: transition: %u --> %u\n",
	91	freqs.old, freqs.new);
	92	#endif
	93
41cfe367	94	ret = clk_set_rate(cpu_clk, freqs.new * 1000);
7056d423 CC	95	if (ret) {
	96	pr_err("cpu-tegra: Failed to set cpu frequency to %d kHz\n",
	97	freqs.new);
	98	return ret;
	99	}
	100
	101	for_each_online_cpu(freqs.cpu)
	102	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	103
	104	return 0;
	105	}
	106
1eb2ecf1 CC	107	static unsigned long tegra_cpu_highest_speed(void)
	108	{
	109	unsigned long rate = 0;
	110	int i;
	111
	112	for_each_online_cpu(i)
	113	rate = max(rate, target_cpu_speed[i]);
	114	return rate;
	115	}
	116
7056d423 CC	117	static int tegra_target(struct cpufreq_policy *policy,
	118	unsigned int target_freq,
	119	unsigned int relation)
	120	{
	121	int idx;
	122	unsigned int freq;
1eb2ecf1 CC	123	int ret = 0;
	124
	125	mutex_lock(&tegra_cpu_lock);
	126
	127	if (is_suspended) {
	128	ret = -EBUSY;
	129	goto out;
	130	}
7056d423 CC	131
	132	cpufreq_frequency_table_target(policy, freq_table, target_freq,
	133	relation, &idx);
	134
	135	freq = freq_table[idx].frequency;
	136
	137	target_cpu_speed[policy->cpu] = freq;
	138
1eb2ecf1 CC	139	ret = tegra_update_cpu_speed(tegra_cpu_highest_speed());
	140
	141	out:
	142	mutex_unlock(&tegra_cpu_lock);
	143	return ret;
7056d423 CC	144	}
7056d423 CC	145
1eb2ecf1 CC	146	static int tegra_pm_notify(struct notifier_block *nb, unsigned long event,
	147	void *dummy)
	148	{
	149	mutex_lock(&tegra_cpu_lock);
	150	if (event == PM_SUSPEND_PREPARE) {
	151	is_suspended = true;
	152	pr_info("Tegra cpufreq suspend: setting frequency to %d kHz\n",
	153	freq_table[0].frequency);
	154	tegra_update_cpu_speed(freq_table[0].frequency);
	155	} else if (event == PM_POST_SUSPEND) {
	156	is_suspended = false;
	157	}
	158	mutex_unlock(&tegra_cpu_lock);
	159
	160	return NOTIFY_OK;
	161	}
	162
	163	static struct notifier_block tegra_cpu_pm_notifier = {
	164	.notifier_call = tegra_pm_notify,
	165	};
	166
7056d423 CC	167	static int tegra_cpu_init(struct cpufreq_policy *policy)
	168	{
	169	if (policy->cpu >= NUM_CPUS)
	170	return -EINVAL;
	171
	172	cpu_clk = clk_get_sys(NULL, "cpu");
	173	if (IS_ERR(cpu_clk))
	174	return PTR_ERR(cpu_clk);
	175
	176	cpufreq_frequency_table_cpuinfo(policy, freq_table);
	177	cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
	178	policy->cur = tegra_getspeed(policy->cpu);
	179	target_cpu_speed[policy->cpu] = policy->cur;
	180
	181	/* FIXME: what's the actual transition time? */
	182	policy->cpuinfo.transition_latency = 300 * 1000;
	183
	184	policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
	185	cpumask_copy(policy->related_cpus, cpu_possible_mask);
	186
1eb2ecf1 CC	187	if (policy->cpu == 0)
	188	register_pm_notifier(&tegra_cpu_pm_notifier);
	189
7056d423 CC	190	return 0;
	191	}
	192
	193	static int tegra_cpu_exit(struct cpufreq_policy *policy)
	194	{
	195	cpufreq_frequency_table_cpuinfo(policy, freq_table);
	196	clk_put(cpu_clk);
	197	return 0;
	198	}
	199
	200	static struct freq_attr *tegra_cpufreq_attr[] = {
	201	&cpufreq_freq_attr_scaling_available_freqs,
	202	NULL,
	203	};
	204
	205	static struct cpufreq_driver tegra_cpufreq_driver = {
	206	.verify = tegra_verify_speed,
	207	.target = tegra_target,
	208	.get = tegra_getspeed,
	209	.init = tegra_cpu_init,
	210	.exit = tegra_cpu_exit,
	211	.name = "tegra",
	212	.attr = tegra_cpufreq_attr,
	213	};
	214
	215	static int __init tegra_cpufreq_init(void)
	216	{
	217	return cpufreq_register_driver(&tegra_cpufreq_driver);
	218	}
	219
	220	static void __exit tegra_cpufreq_exit(void)
	221	{
	222	cpufreq_unregister_driver(&tegra_cpufreq_driver);
	223	}
	224
	225
	226	MODULE_AUTHOR("Colin Cross <ccross@android.com>");
	227	MODULE_DESCRIPTION("cpufreq driver for Nvidia Tegra2");
	228	MODULE_LICENSE("GPL");
	229	module_init(tegra_cpufreq_init);
	230	module_exit(tegra_cpufreq_exit);