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

/*
 * arch/arm/mach-tegra/cpu-tegra.c
 *
 * Copyright (C) 2010 Google, Inc.
 *
 * Author:
 *	Colin Cross <[email protected]>
 *	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 struct clk *emc_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;

	/*
	 * 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 */

	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);

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

	clk_enable(emc_clk);
	clk_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;

	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_disable(emc_clk);
	clk_put(emc_clk);
	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 <[email protected]>");
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 <[email protected]>
	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;
7a281284	54	static struct clk *emc_clk;
7056d423 CC	55
7056d423 CC	56	static unsigned long target_cpu_speed[NUM_CPUS];
1eb2ecf1 CC	57	static DEFINE_MUTEX(tegra_cpu_lock);
1eb2ecf1 CC	58	static bool is_suspended;
7056d423 CC	59
	60	int tegra_verify_speed(struct cpufreq_policy *policy)
	61	{
	62	return cpufreq_frequency_table_verify(policy, freq_table);
	63	}
	64
	65	unsigned int tegra_getspeed(unsigned int cpu)
	66	{
	67	unsigned long rate;
	68
	69	if (cpu >= NUM_CPUS)
	70	return 0;
	71
	72	rate = clk_get_rate(cpu_clk) / 1000;
	73	return rate;
	74	}
	75
1eb2ecf1	76	static int tegra_update_cpu_speed(unsigned long rate)
7056d423	77	{
7056d423 CC	78	int ret = 0;
	79	struct cpufreq_freqs freqs;
	80
7056d423 CC	81	freqs.old = tegra_getspeed(0);
	82	freqs.new = rate;
	83
	84	if (freqs.old == freqs.new)
	85	return ret;
	86
7a281284 CC	87	/*
	88	* Vote on memory bus frequency based on cpu frequency
	89	* This sets the minimum frequency, display or avp may request higher
	90	*/
	91	if (rate >= 816000)
	92	clk_set_rate(emc_clk, 600000000); /* cpu 816 MHz, emc max */
	93	else if (rate >= 456000)
	94	clk_set_rate(emc_clk, 300000000); /* cpu 456 MHz, emc 150Mhz */
	95	else
	96	clk_set_rate(emc_clk, 100000000); /* emc 50Mhz */
	97
7056d423 CC	98	for_each_online_cpu(freqs.cpu)
	99	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	100
	101	#ifdef CONFIG_CPU_FREQ_DEBUG
	102	printk(KERN_DEBUG "cpufreq-tegra: transition: %u --> %u\n",
	103	freqs.old, freqs.new);
	104	#endif
	105
41cfe367	106	ret = clk_set_rate(cpu_clk, freqs.new * 1000);
7056d423 CC	107	if (ret) {
	108	pr_err("cpu-tegra: Failed to set cpu frequency to %d kHz\n",
	109	freqs.new);
	110	return ret;
	111	}
	112
	113	for_each_online_cpu(freqs.cpu)
	114	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	115
	116	return 0;
	117	}
	118
1eb2ecf1 CC	119	static unsigned long tegra_cpu_highest_speed(void)
	120	{
	121	unsigned long rate = 0;
	122	int i;
	123
	124	for_each_online_cpu(i)
	125	rate = max(rate, target_cpu_speed[i]);
	126	return rate;
	127	}
	128
7056d423 CC	129	static int tegra_target(struct cpufreq_policy *policy,
	130	unsigned int target_freq,
	131	unsigned int relation)
	132	{
	133	int idx;
	134	unsigned int freq;
1eb2ecf1 CC	135	int ret = 0;
	136
	137	mutex_lock(&tegra_cpu_lock);
	138
	139	if (is_suspended) {
	140	ret = -EBUSY;
	141	goto out;
	142	}
7056d423 CC	143
	144	cpufreq_frequency_table_target(policy, freq_table, target_freq,
	145	relation, &idx);
	146
	147	freq = freq_table[idx].frequency;
	148
	149	target_cpu_speed[policy->cpu] = freq;
	150
1eb2ecf1 CC	151	ret = tegra_update_cpu_speed(tegra_cpu_highest_speed());
	152
	153	out:
	154	mutex_unlock(&tegra_cpu_lock);
	155	return ret;
7056d423 CC	156	}
7056d423 CC	157
1eb2ecf1 CC	158	static int tegra_pm_notify(struct notifier_block *nb, unsigned long event,
	159	void *dummy)
	160	{
	161	mutex_lock(&tegra_cpu_lock);
	162	if (event == PM_SUSPEND_PREPARE) {
	163	is_suspended = true;
	164	pr_info("Tegra cpufreq suspend: setting frequency to %d kHz\n",
	165	freq_table[0].frequency);
	166	tegra_update_cpu_speed(freq_table[0].frequency);
	167	} else if (event == PM_POST_SUSPEND) {
	168	is_suspended = false;
	169	}
	170	mutex_unlock(&tegra_cpu_lock);
	171
	172	return NOTIFY_OK;
	173	}
	174
	175	static struct notifier_block tegra_cpu_pm_notifier = {
	176	.notifier_call = tegra_pm_notify,
	177	};
	178
7056d423 CC	179	static int tegra_cpu_init(struct cpufreq_policy *policy)
	180	{
	181	if (policy->cpu >= NUM_CPUS)
	182	return -EINVAL;
	183
	184	cpu_clk = clk_get_sys(NULL, "cpu");
	185	if (IS_ERR(cpu_clk))
	186	return PTR_ERR(cpu_clk);
	187
7a281284 CC	188	emc_clk = clk_get_sys("cpu", "emc");
	189	if (IS_ERR(emc_clk)) {
	190	clk_put(cpu_clk);
	191	return PTR_ERR(emc_clk);
	192	}
	193
	194	clk_enable(emc_clk);
89a5fb84 CC	195	clk_enable(cpu_clk);
89a5fb84 CC	196
7056d423 CC	197	cpufreq_frequency_table_cpuinfo(policy, freq_table);
	198	cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
	199	policy->cur = tegra_getspeed(policy->cpu);
	200	target_cpu_speed[policy->cpu] = policy->cur;
	201
	202	/* FIXME: what's the actual transition time? */
	203	policy->cpuinfo.transition_latency = 300 * 1000;
	204
	205	policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
	206	cpumask_copy(policy->related_cpus, cpu_possible_mask);
	207
1eb2ecf1 CC	208	if (policy->cpu == 0)
	209	register_pm_notifier(&tegra_cpu_pm_notifier);
	210
7056d423 CC	211	return 0;
	212	}
	213
	214	static int tegra_cpu_exit(struct cpufreq_policy *policy)
	215	{
	216	cpufreq_frequency_table_cpuinfo(policy, freq_table);
7a281284 CC	217	clk_disable(emc_clk);
7a281284 CC	218	clk_put(emc_clk);
7056d423 CC	219	clk_put(cpu_clk);
	220	return 0;
	221	}
	222
	223	static struct freq_attr *tegra_cpufreq_attr[] = {
	224	&cpufreq_freq_attr_scaling_available_freqs,
	225	NULL,
	226	};
	227
	228	static struct cpufreq_driver tegra_cpufreq_driver = {
	229	.verify = tegra_verify_speed,
	230	.target = tegra_target,
	231	.get = tegra_getspeed,
	232	.init = tegra_cpu_init,
	233	.exit = tegra_cpu_exit,
	234	.name = "tegra",
	235	.attr = tegra_cpufreq_attr,
	236	};
	237
	238	static int __init tegra_cpufreq_init(void)
	239	{
	240	return cpufreq_register_driver(&tegra_cpufreq_driver);
	241	}
	242
	243	static void __exit tegra_cpufreq_exit(void)
	244	{
	245	cpufreq_unregister_driver(&tegra_cpufreq_driver);
	246	}
	247
	248
	249	MODULE_AUTHOR("Colin Cross <[email protected]>");
	250	MODULE_DESCRIPTION("cpufreq driver for Nvidia Tegra2");
	251	MODULE_LICENSE("GPL");
	252	module_init(tegra_cpufreq_init);
	253	module_exit(tegra_cpufreq_exit);