[deliverable/linux.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 <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;

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_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)
{
	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(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 <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	32
7056d423	33
7056d423 CC	34	#include <mach/clk.h>
	35
	36	/* Frequency table index must be sequential starting at 0 */
	37	static struct cpufreq_frequency_table freq_table[] = {
1eb2ecf1 CC	38	{ 0, 216000 },
	39	{ 1, 312000 },
	40	{ 2, 456000 },
	41	{ 3, 608000 },
	42	{ 4, 760000 },
	43	{ 5, 816000 },
	44	{ 6, 912000 },
	45	{ 7, 1000000 },
	46	{ 8, CPUFREQ_TABLE_END },
7056d423 CC	47	};
	48
	49	#define NUM_CPUS 2
	50
	51	static struct clk *cpu_clk;
7a281284	52	static struct clk *emc_clk;
7056d423 CC	53
7056d423 CC	54	static unsigned long target_cpu_speed[NUM_CPUS];
1eb2ecf1 CC	55	static DEFINE_MUTEX(tegra_cpu_lock);
1eb2ecf1 CC	56	static bool is_suspended;
7056d423	57
6686c733	58	static int tegra_verify_speed(struct cpufreq_policy *policy)
7056d423 CC	59	{
	60	return cpufreq_frequency_table_verify(policy, freq_table);
	61	}
	62
6686c733	63	static unsigned int tegra_getspeed(unsigned int cpu)
7056d423 CC	64	{
	65	unsigned long rate;
	66
	67	if (cpu >= NUM_CPUS)
	68	return 0;
	69
	70	rate = clk_get_rate(cpu_clk) / 1000;
	71	return rate;
	72	}
	73
1eb2ecf1	74	static int tegra_update_cpu_speed(unsigned long rate)
7056d423	75	{
7056d423 CC	76	int ret = 0;
	77	struct cpufreq_freqs freqs;
	78
7056d423 CC	79	freqs.old = tegra_getspeed(0);
	80	freqs.new = rate;
	81
	82	if (freqs.old == freqs.new)
	83	return ret;
	84
7a281284 CC	85	/*
	86	* Vote on memory bus frequency based on cpu frequency
	87	* This sets the minimum frequency, display or avp may request higher
	88	*/
	89	if (rate >= 816000)
	90	clk_set_rate(emc_clk, 600000000); /* cpu 816 MHz, emc max */
	91	else if (rate >= 456000)
	92	clk_set_rate(emc_clk, 300000000); /* cpu 456 MHz, emc 150Mhz */
	93	else
	94	clk_set_rate(emc_clk, 100000000); /* emc 50Mhz */
	95
7056d423 CC	96	for_each_online_cpu(freqs.cpu)
	97	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	98
	99	#ifdef CONFIG_CPU_FREQ_DEBUG
	100	printk(KERN_DEBUG "cpufreq-tegra: transition: %u --> %u\n",
	101	freqs.old, freqs.new);
	102	#endif
	103
41cfe367	104	ret = clk_set_rate(cpu_clk, freqs.new * 1000);
7056d423 CC	105	if (ret) {
	106	pr_err("cpu-tegra: Failed to set cpu frequency to %d kHz\n",
	107	freqs.new);
	108	return ret;
	109	}
	110
	111	for_each_online_cpu(freqs.cpu)
	112	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	113
	114	return 0;
	115	}
	116
1eb2ecf1 CC	117	static unsigned long tegra_cpu_highest_speed(void)
	118	{
	119	unsigned long rate = 0;
	120	int i;
	121
	122	for_each_online_cpu(i)
	123	rate = max(rate, target_cpu_speed[i]);
	124	return rate;
	125	}
	126
7056d423 CC	127	static int tegra_target(struct cpufreq_policy *policy,
	128	unsigned int target_freq,
	129	unsigned int relation)
	130	{
fdb684ac	131	unsigned int idx;
7056d423	132	unsigned int freq;
1eb2ecf1 CC	133	int ret = 0;
	134
	135	mutex_lock(&tegra_cpu_lock);
	136
	137	if (is_suspended) {
	138	ret = -EBUSY;
	139	goto out;
	140	}
7056d423 CC	141
	142	cpufreq_frequency_table_target(policy, freq_table, target_freq,
	143	relation, &idx);
	144
	145	freq = freq_table[idx].frequency;
	146
	147	target_cpu_speed[policy->cpu] = freq;
	148
1eb2ecf1 CC	149	ret = tegra_update_cpu_speed(tegra_cpu_highest_speed());
	150
	151	out:
	152	mutex_unlock(&tegra_cpu_lock);
	153	return ret;
7056d423 CC	154	}
7056d423 CC	155
1eb2ecf1 CC	156	static int tegra_pm_notify(struct notifier_block *nb, unsigned long event,
	157	void *dummy)
	158	{
	159	mutex_lock(&tegra_cpu_lock);
	160	if (event == PM_SUSPEND_PREPARE) {
	161	is_suspended = true;
	162	pr_info("Tegra cpufreq suspend: setting frequency to %d kHz\n",
	163	freq_table[0].frequency);
	164	tegra_update_cpu_speed(freq_table[0].frequency);
	165	} else if (event == PM_POST_SUSPEND) {
	166	is_suspended = false;
	167	}
	168	mutex_unlock(&tegra_cpu_lock);
	169
	170	return NOTIFY_OK;
	171	}
	172
	173	static struct notifier_block tegra_cpu_pm_notifier = {
	174	.notifier_call = tegra_pm_notify,
	175	};
	176
7056d423 CC	177	static int tegra_cpu_init(struct cpufreq_policy *policy)
	178	{
	179	if (policy->cpu >= NUM_CPUS)
	180	return -EINVAL;
	181
	182	cpu_clk = clk_get_sys(NULL, "cpu");
	183	if (IS_ERR(cpu_clk))
	184	return PTR_ERR(cpu_clk);
	185
7a281284 CC	186	emc_clk = clk_get_sys("cpu", "emc");
	187	if (IS_ERR(emc_clk)) {
	188	clk_put(cpu_clk);
	189	return PTR_ERR(emc_clk);
	190	}
	191
	192	clk_enable(emc_clk);
89a5fb84 CC	193	clk_enable(cpu_clk);
89a5fb84 CC	194
7056d423 CC	195	cpufreq_frequency_table_cpuinfo(policy, freq_table);
	196	cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
	197	policy->cur = tegra_getspeed(policy->cpu);
	198	target_cpu_speed[policy->cpu] = policy->cur;
	199
	200	/* FIXME: what's the actual transition time? */
	201	policy->cpuinfo.transition_latency = 300 * 1000;
	202
	203	policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
	204	cpumask_copy(policy->related_cpus, cpu_possible_mask);
	205
1eb2ecf1 CC	206	if (policy->cpu == 0)
	207	register_pm_notifier(&tegra_cpu_pm_notifier);
	208
7056d423 CC	209	return 0;
	210	}
	211
	212	static int tegra_cpu_exit(struct cpufreq_policy *policy)
	213	{
	214	cpufreq_frequency_table_cpuinfo(policy, freq_table);
7a281284 CC	215	clk_disable(emc_clk);
7a281284 CC	216	clk_put(emc_clk);
7056d423 CC	217	clk_put(cpu_clk);
	218	return 0;
	219	}
	220
	221	static struct freq_attr *tegra_cpufreq_attr[] = {
	222	&cpufreq_freq_attr_scaling_available_freqs,
	223	NULL,
	224	};
	225
	226	static struct cpufreq_driver tegra_cpufreq_driver = {
	227	.verify = tegra_verify_speed,
	228	.target = tegra_target,
	229	.get = tegra_getspeed,
	230	.init = tegra_cpu_init,
	231	.exit = tegra_cpu_exit,
	232	.name = "tegra",
	233	.attr = tegra_cpufreq_attr,
	234	};
	235
	236	static int __init tegra_cpufreq_init(void)
	237	{
	238	return cpufreq_register_driver(&tegra_cpufreq_driver);
	239	}
	240
	241	static void __exit tegra_cpufreq_exit(void)
	242	{
	243	cpufreq_unregister_driver(&tegra_cpufreq_driver);
	244	}
	245
	246
	247	MODULE_AUTHOR("Colin Cross <ccross@android.com>");
	248	MODULE_DESCRIPTION("cpufreq driver for Nvidia Tegra2");
	249	MODULE_LICENSE("GPL");
	250	module_init(tegra_cpufreq_init);
	251	module_exit(tegra_cpufreq_exit);