[linux-2.6-block.git] / drivers / cpufreq / omap-cpufreq.c

/*
 *  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/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);
	freqs.cpu = policy->cpu;

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

	/* notifiers */
	for_each_cpu(i, policy->cpus) {
		freqs.cpu = i;
		cpufreq_notify_transition(&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 */
	for_each_cpu(i, policy->cpus) {
		freqs.cpu = i;
		cpufreq_notify_transition(&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 = policy->min = policy->max = 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->min = policy->cpuinfo.min_freq;
	policy->max = policy->cpuinfo.max_freq;
	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 __init omap_cpufreq_init(void)
{
	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 void __exit omap_cpufreq_exit(void)
{
	cpufreq_unregister_driver(&omap_driver);
}

MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
MODULE_LICENSE("GPL");
module_init(omap_cpufreq_init);
module_exit(omap_cpufreq_exit);
Commit	Line	Data
ec6bced6	1	/*
ffe4f0f1	2	* CPU frequency scaling for OMAP using OPP information
ec6bced6 TL	3	*
	4	* Copyright (C) 2005 Nokia Corporation
	5	* Written by Tony Lindgren <tony@atomide.com>
	6	*
	7	* Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
	8	*
731e0cc6 SS	9	* Copyright (C) 2007-2011 Texas Instruments, Inc.
	10	* - OMAP3/4 support by Rajendra Nayak, Santosh Shilimkar
	11	*
ec6bced6 TL	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License version 2 as
	14	* published by the Free Software Foundation.
	15	*/
	16	#include <linux/types.h>
	17	#include <linux/kernel.h>
	18	#include <linux/sched.h>
	19	#include <linux/cpufreq.h>
	20	#include <linux/delay.h>
	21	#include <linux/init.h>
	22	#include <linux/err.h>
f8ce2547	23	#include <linux/clk.h>
fced80c7	24	#include <linux/io.h>
731e0cc6	25	#include <linux/opp.h>
46c12216	26	#include <linux/cpu.h>
c1b547bc	27	#include <linux/module.h>
53dfe8a8	28	#include <linux/regulator/consumer.h>
ec6bced6	29
731e0cc6	30	#include <asm/smp_plat.h>
46c12216	31	#include <asm/cpu.h>
ec6bced6	32
42daffd2 AM	33	/* OPP tolerance in percentage */
	34	#define OPP_TOLERANCE 4
	35
731e0cc6	36	static struct cpufreq_frequency_table *freq_table;
1c78217f	37	static atomic_t freq_table_users = ATOMIC_INIT(0);
b8488fbe	38	static struct clk *mpu_clk;
a820ffa8	39	static struct device *mpu_dev;
53dfe8a8	40	static struct regulator *mpu_reg;
b8488fbe	41
b0a330dc	42	static int omap_verify_speed(struct cpufreq_policy *policy)
ec6bced6	43	{
bf2a359d	44	if (!freq_table)
ec6bced6	45	return -EINVAL;
bf2a359d	46	return cpufreq_frequency_table_verify(policy, freq_table);
ec6bced6 TL	47	}
ec6bced6 TL	48
b0a330dc	49	static unsigned int omap_getspeed(unsigned int cpu)
ec6bced6	50	{
ec6bced6 TL	51	unsigned long rate;
ec6bced6 TL	52
46c12216	53	if (cpu >= NR_CPUS)
ec6bced6 TL	54	return 0;
ec6bced6 TL	55
ec6bced6	56	rate = clk_get_rate(mpu_clk) / 1000;
ec6bced6 TL	57	return rate;
	58	}
	59
	60	static int omap_target(struct cpufreq_policy *policy,
	61	unsigned int target_freq,
	62	unsigned int relation)
	63	{
bf2a359d	64	unsigned int i;
53dfe8a8	65	int r, ret = 0;
731e0cc6	66	struct cpufreq_freqs freqs;
53dfe8a8	67	struct opp *opp;
42daffd2	68	unsigned long freq, volt = 0, volt_old = 0, tol = 0;
ec6bced6	69
bf2a359d NM	70	if (!freq_table) {
	71	dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__,
	72	policy->cpu);
	73	return -EINVAL;
	74	}
	75
	76	ret = cpufreq_frequency_table_target(policy, freq_table, target_freq,
	77	relation, &i);
	78	if (ret) {
	79	dev_dbg(mpu_dev, "%s: cpu%d: no freq match for %d(ret=%d)\n",
	80	__func__, policy->cpu, target_freq, ret);
	81	return ret;
	82	}
	83	freqs.new = freq_table[i].frequency;
	84	if (!freqs.new) {
	85	dev_err(mpu_dev, "%s: cpu%d: no match for freq %d\n", __func__,
	86	policy->cpu, target_freq);
	87	return -EINVAL;
	88	}
aeec2990	89
46c12216	90	freqs.old = omap_getspeed(policy->cpu);
46c12216	91	freqs.cpu = policy->cpu;
ec6bced6	92
022ac03b	93	if (freqs.old == freqs.new && policy->cur == freqs.new)
aeec2990 KH	94	return ret;
aeec2990 KH	95
46c12216 RK	96	/* notifiers */
	97	for_each_cpu(i, policy->cpus) {
	98	freqs.cpu = i;
	99	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	100	}
731e0cc6	101
53dfe8a8	102	freq = freqs.new * 1000;
8df0a663 KH	103	ret = clk_round_rate(mpu_clk, freq);
	104	if (IS_ERR_VALUE(ret)) {
	105	dev_warn(mpu_dev,
	106	"CPUfreq: Cannot find matching frequency for %lu\n",
	107	freq);
	108	return ret;
	109	}
	110	freq = ret;
53dfe8a8 KH	111
53dfe8a8 KH	112	if (mpu_reg) {
f44d188a	113	rcu_read_lock();
53dfe8a8 KH	114	opp = opp_find_freq_ceil(mpu_dev, &freq);
53dfe8a8 KH	115	if (IS_ERR(opp)) {
f44d188a	116	rcu_read_unlock();
53dfe8a8 KH	117	dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
	118	__func__, freqs.new);
	119	return -EINVAL;
	120	}
	121	volt = opp_get_voltage(opp);
f44d188a	122	rcu_read_unlock();
42daffd2	123	tol = volt * OPP_TOLERANCE / 100;
53dfe8a8 KH	124	volt_old = regulator_get_voltage(mpu_reg);
	125	}
	126
	127	dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n",
	128	freqs.old / 1000, volt_old ? volt_old / 1000 : -1,
	129	freqs.new / 1000, volt ? volt / 1000 : -1);
	130
	131	/* scaling up? scale voltage before frequency */
	132	if (mpu_reg && (freqs.new > freqs.old)) {
42daffd2	133	r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
53dfe8a8 KH	134	if (r < 0) {
	135	dev_warn(mpu_dev, "%s: unable to scale voltage up.\n",
	136	__func__);
	137	freqs.new = freqs.old;
	138	goto done;
	139	}
	140	}
731e0cc6	141
aeec2990	142	ret = clk_set_rate(mpu_clk, freqs.new * 1000);
46c12216	143
53dfe8a8 KH	144	/* scaling down? scale voltage after frequency */
53dfe8a8 KH	145	if (mpu_reg && (freqs.new < freqs.old)) {
42daffd2	146	r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
53dfe8a8 KH	147	if (r < 0) {
	148	dev_warn(mpu_dev, "%s: unable to scale voltage down.\n",
	149	__func__);
	150	ret = clk_set_rate(mpu_clk, freqs.old * 1000);
	151	freqs.new = freqs.old;
	152	goto done;
	153	}
	154	}
	155
	156	freqs.new = omap_getspeed(policy->cpu);
46c12216	157
53dfe8a8	158	done:
46c12216 RK	159	/* notifiers */
	160	for_each_cpu(i, policy->cpus) {
	161	freqs.cpu = i;
	162	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	163	}
ec6bced6 TL	164
	165	return ret;
	166	}
	167
1c78217f NM	168	static inline void freq_table_free(void)
	169	{
	170	if (atomic_dec_and_test(&freq_table_users))
	171	opp_free_cpufreq_table(mpu_dev, &freq_table);
	172	}
	173
790ab7e9	174	static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
ec6bced6	175	{
aeec2990	176	int result = 0;
731e0cc6	177
e2ee1b4d	178	mpu_clk = clk_get(NULL, "cpufreq_ck");
ec6bced6 TL	179	if (IS_ERR(mpu_clk))
	180	return PTR_ERR(mpu_clk);
	181
11e04fdd NM	182	if (policy->cpu >= NR_CPUS) {
	183	result = -EINVAL;
	184	goto fail_ck;
	185	}
aeec2990	186
46c12216	187	policy->cur = policy->min = policy->max = omap_getspeed(policy->cpu);
1c78217f	188
1b865214	189	if (!freq_table)
1c78217f	190	result = opp_init_cpufreq_table(mpu_dev, &freq_table);
bf2a359d NM	191
	192	if (result) {
	193	dev_err(mpu_dev, "%s: cpu%d: failed creating freq table[%d]\n",
	194	__func__, policy->cpu, result);
11e04fdd	195	goto fail_ck;
aeec2990 KH	196	}
aeec2990 KH	197
1b865214 RN	198	atomic_inc_return(&freq_table_users);
1b865214 RN	199
bf2a359d	200	result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
1c78217f NM	201	if (result)
	202	goto fail_table;
	203
	204	cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
bf2a359d	205
731e0cc6 SS	206	policy->min = policy->cpuinfo.min_freq;
731e0cc6 SS	207	policy->max = policy->cpuinfo.max_freq;
46c12216 RK	208	policy->cur = omap_getspeed(policy->cpu);
	209
	210	/*
	211	* On OMAP SMP configuartion, both processors share the voltage
	212	* and clock. So both CPUs needs to be scaled together and hence
	213	* needs software co-ordination. Use cpufreq affected_cpus
	214	* interface to handle this scenario. Additional is_smp() check
	215	* is to keep SMP_ON_UP build working.
	216	*/
62b36cc1	217	if (is_smp())
ed8ce00c	218	cpumask_setall(policy->cpus);
731e0cc6	219
aeec2990	220	/* FIXME: what's the actual transition time? */
b029839c	221	policy->cpuinfo.transition_latency = 300 * 1000;
ec6bced6 TL	222
ec6bced6 TL	223	return 0;
11e04fdd	224
1c78217f NM	225	fail_table:
1c78217f NM	226	freq_table_free();
11e04fdd NM	227	fail_ck:
	228	clk_put(mpu_clk);
	229	return result;
ec6bced6 TL	230	}
ec6bced6 TL	231
b8488fbe HD	232	static int omap_cpu_exit(struct cpufreq_policy *policy)
b8488fbe HD	233	{
1c78217f	234	freq_table_free();
b8488fbe HD	235	clk_put(mpu_clk);
	236	return 0;
	237	}
	238
aeec2990 KH	239	static struct freq_attr *omap_cpufreq_attr[] = {
	240	&cpufreq_freq_attr_scaling_available_freqs,
	241	NULL,
	242	};
	243
ec6bced6 TL	244	static struct cpufreq_driver omap_driver = {
	245	.flags = CPUFREQ_STICKY,
	246	.verify = omap_verify_speed,
	247	.target = omap_target,
	248	.get = omap_getspeed,
	249	.init = omap_cpu_init,
b8488fbe	250	.exit = omap_cpu_exit,
ec6bced6	251	.name = "omap",
aeec2990	252	.attr = omap_cpufreq_attr,
ec6bced6 TL	253	};
	254
	255	static int __init omap_cpufreq_init(void)
	256	{
747a7f64 KH	257	mpu_dev = get_cpu_device(0);
747a7f64 KH	258	if (!mpu_dev) {
a820ffa8	259	pr_warning("%s: unable to get the mpu device\n", __func__);
747a7f64	260	return -EINVAL;
a820ffa8 NM	261	}
a820ffa8 NM	262
53dfe8a8 KH	263	mpu_reg = regulator_get(mpu_dev, "vcc");
	264	if (IS_ERR(mpu_reg)) {
	265	pr_warning("%s: unable to get MPU regulator\n", __func__);
	266	mpu_reg = NULL;
	267	} else {
	268	/*
	269	* Ensure physical regulator is present.
	270	* (e.g. could be dummy regulator.)
	271	*/
	272	if (regulator_get_voltage(mpu_reg) < 0) {
	273	pr_warn("%s: physical regulator not present for MPU\n",
	274	__func__);
	275	regulator_put(mpu_reg);
	276	mpu_reg = NULL;
	277	}
	278	}
	279
ec6bced6 TL	280	return cpufreq_register_driver(&omap_driver);
	281	}
	282
731e0cc6 SS	283	static void __exit omap_cpufreq_exit(void)
	284	{
	285	cpufreq_unregister_driver(&omap_driver);
	286	}
aeec2990	287
731e0cc6 SS	288	MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
	289	MODULE_LICENSE("GPL");
	290	module_init(omap_cpufreq_init);
	291	module_exit(omap_cpufreq_exit);