[mirror_ubuntu-artful-kernel.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>

#include <plat/clock.h>
#include <plat/omap-pm.h>
#include <plat/common.h>
#include <plat/omap_device.h>

#include <mach/hardware.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 char *mpu_clk_name;
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;

	if (mpu_reg) {
		opp = opp_find_freq_ceil(mpu_dev, &freq);
		if (IS_ERR(opp)) {
			dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
				__func__, freqs.new);
			return -EINVAL;
		}
		volt = opp_get_voltage(opp);
		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, mpu_clk_name);
	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()) {
		policy->shared_type = CPUFREQ_SHARED_TYPE_ANY;
		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)
{
	if (cpu_is_omap24xx())
		mpu_clk_name = "virt_prcm_set";
	else if (cpu_is_omap34xx())
		mpu_clk_name = "dpll1_ck";
	else if (cpu_is_omap44xx())
		mpu_clk_name = "dpll_mpu_ck";

	if (!mpu_clk_name) {
		pr_err("%s: unsupported Silicon?\n", __func__);
		return -EINVAL;
	}

	mpu_dev = omap_device_get_by_hwmod_name("mpu");
	if (IS_ERR(mpu_dev)) {
		pr_warning("%s: unable to get the mpu device\n", __func__);
		return PTR_ERR(mpu_dev);
	}

	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
731e0cc6 SS	33	#include <plat/clock.h>
	34	#include <plat/omap-pm.h>
	35	#include <plat/common.h>
c1b547bc	36	#include <plat/omap_device.h>
a7ca9d2b	37
731e0cc6	38	#include <mach/hardware.h>
aeec2990	39
42daffd2 AM	40	/* OPP tolerance in percentage */
	41	#define OPP_TOLERANCE 4
	42
731e0cc6	43	static struct cpufreq_frequency_table *freq_table;
1c78217f	44	static atomic_t freq_table_users = ATOMIC_INIT(0);
b8488fbe	45	static struct clk *mpu_clk;
08ca3e3b	46	static char *mpu_clk_name;
a820ffa8	47	static struct device *mpu_dev;
53dfe8a8	48	static struct regulator *mpu_reg;
b8488fbe	49
b0a330dc	50	static int omap_verify_speed(struct cpufreq_policy *policy)
ec6bced6	51	{
bf2a359d	52	if (!freq_table)
ec6bced6	53	return -EINVAL;
bf2a359d	54	return cpufreq_frequency_table_verify(policy, freq_table);
ec6bced6 TL	55	}
ec6bced6 TL	56
b0a330dc	57	static unsigned int omap_getspeed(unsigned int cpu)
ec6bced6	58	{
ec6bced6 TL	59	unsigned long rate;
ec6bced6 TL	60
46c12216	61	if (cpu >= NR_CPUS)
ec6bced6 TL	62	return 0;
ec6bced6 TL	63
ec6bced6	64	rate = clk_get_rate(mpu_clk) / 1000;
ec6bced6 TL	65	return rate;
	66	}
	67
	68	static int omap_target(struct cpufreq_policy *policy,
	69	unsigned int target_freq,
	70	unsigned int relation)
	71	{
bf2a359d	72	unsigned int i;
53dfe8a8	73	int r, ret = 0;
731e0cc6	74	struct cpufreq_freqs freqs;
53dfe8a8	75	struct opp *opp;
42daffd2	76	unsigned long freq, volt = 0, volt_old = 0, tol = 0;
ec6bced6	77
bf2a359d NM	78	if (!freq_table) {
	79	dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__,
	80	policy->cpu);
	81	return -EINVAL;
	82	}
	83
	84	ret = cpufreq_frequency_table_target(policy, freq_table, target_freq,
	85	relation, &i);
	86	if (ret) {
	87	dev_dbg(mpu_dev, "%s: cpu%d: no freq match for %d(ret=%d)\n",
	88	__func__, policy->cpu, target_freq, ret);
	89	return ret;
	90	}
	91	freqs.new = freq_table[i].frequency;
	92	if (!freqs.new) {
	93	dev_err(mpu_dev, "%s: cpu%d: no match for freq %d\n", __func__,
	94	policy->cpu, target_freq);
	95	return -EINVAL;
	96	}
aeec2990	97
46c12216	98	freqs.old = omap_getspeed(policy->cpu);
46c12216	99	freqs.cpu = policy->cpu;
ec6bced6	100
022ac03b	101	if (freqs.old == freqs.new && policy->cur == freqs.new)
aeec2990 KH	102	return ret;
aeec2990 KH	103
46c12216 RK	104	/* notifiers */
	105	for_each_cpu(i, policy->cpus) {
	106	freqs.cpu = i;
	107	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	108	}
731e0cc6	109
53dfe8a8 KH	110	freq = freqs.new * 1000;
	111
	112	if (mpu_reg) {
	113	opp = opp_find_freq_ceil(mpu_dev, &freq);
	114	if (IS_ERR(opp)) {
	115	dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
	116	__func__, freqs.new);
	117	return -EINVAL;
	118	}
	119	volt = opp_get_voltage(opp);
42daffd2	120	tol = volt * OPP_TOLERANCE / 100;
53dfe8a8 KH	121	volt_old = regulator_get_voltage(mpu_reg);
	122	}
	123
	124	dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n",
	125	freqs.old / 1000, volt_old ? volt_old / 1000 : -1,
	126	freqs.new / 1000, volt ? volt / 1000 : -1);
	127
	128	/* scaling up? scale voltage before frequency */
	129	if (mpu_reg && (freqs.new > freqs.old)) {
42daffd2	130	r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
53dfe8a8 KH	131	if (r < 0) {
	132	dev_warn(mpu_dev, "%s: unable to scale voltage up.\n",
	133	__func__);
	134	freqs.new = freqs.old;
	135	goto done;
	136	}
	137	}
731e0cc6	138
aeec2990	139	ret = clk_set_rate(mpu_clk, freqs.new * 1000);
46c12216	140
53dfe8a8 KH	141	/* scaling down? scale voltage after frequency */
53dfe8a8 KH	142	if (mpu_reg && (freqs.new < freqs.old)) {
42daffd2	143	r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
53dfe8a8 KH	144	if (r < 0) {
	145	dev_warn(mpu_dev, "%s: unable to scale voltage down.\n",
	146	__func__);
	147	ret = clk_set_rate(mpu_clk, freqs.old * 1000);
	148	freqs.new = freqs.old;
	149	goto done;
	150	}
	151	}
	152
	153	freqs.new = omap_getspeed(policy->cpu);
46c12216	154
53dfe8a8	155	done:
46c12216 RK	156	/* notifiers */
	157	for_each_cpu(i, policy->cpus) {
	158	freqs.cpu = i;
	159	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	160	}
ec6bced6 TL	161
	162	return ret;
	163	}
	164
1c78217f NM	165	static inline void freq_table_free(void)
	166	{
	167	if (atomic_dec_and_test(&freq_table_users))
	168	opp_free_cpufreq_table(mpu_dev, &freq_table);
	169	}
	170
790ab7e9	171	static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
ec6bced6	172	{
aeec2990	173	int result = 0;
731e0cc6	174
08ca3e3b	175	mpu_clk = clk_get(NULL, mpu_clk_name);
ec6bced6 TL	176	if (IS_ERR(mpu_clk))
	177	return PTR_ERR(mpu_clk);
	178
11e04fdd NM	179	if (policy->cpu >= NR_CPUS) {
	180	result = -EINVAL;
	181	goto fail_ck;
	182	}
aeec2990	183
46c12216	184	policy->cur = policy->min = policy->max = omap_getspeed(policy->cpu);
1c78217f	185
1b865214	186	if (!freq_table)
1c78217f	187	result = opp_init_cpufreq_table(mpu_dev, &freq_table);
bf2a359d NM	188
	189	if (result) {
	190	dev_err(mpu_dev, "%s: cpu%d: failed creating freq table[%d]\n",
	191	__func__, policy->cpu, result);
11e04fdd	192	goto fail_ck;
aeec2990 KH	193	}
aeec2990 KH	194
1b865214 RN	195	atomic_inc_return(&freq_table_users);
1b865214 RN	196
bf2a359d	197	result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
1c78217f NM	198	if (result)
	199	goto fail_table;
	200
	201	cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
bf2a359d	202
731e0cc6 SS	203	policy->min = policy->cpuinfo.min_freq;
731e0cc6 SS	204	policy->max = policy->cpuinfo.max_freq;
46c12216 RK	205	policy->cur = omap_getspeed(policy->cpu);
	206
	207	/*
	208	* On OMAP SMP configuartion, both processors share the voltage
	209	* and clock. So both CPUs needs to be scaled together and hence
	210	* needs software co-ordination. Use cpufreq affected_cpus
	211	* interface to handle this scenario. Additional is_smp() check
	212	* is to keep SMP_ON_UP build working.
	213	*/
	214	if (is_smp()) {
	215	policy->shared_type = CPUFREQ_SHARED_TYPE_ANY;
ed8ce00c	216	cpumask_setall(policy->cpus);
46c12216	217	}
731e0cc6	218
aeec2990	219	/* FIXME: what's the actual transition time? */
b029839c	220	policy->cpuinfo.transition_latency = 300 * 1000;
ec6bced6 TL	221
ec6bced6 TL	222	return 0;
11e04fdd	223
1c78217f NM	224	fail_table:
1c78217f NM	225	freq_table_free();
11e04fdd NM	226	fail_ck:
	227	clk_put(mpu_clk);
	228	return result;
ec6bced6 TL	229	}
ec6bced6 TL	230
b8488fbe HD	231	static int omap_cpu_exit(struct cpufreq_policy *policy)
b8488fbe HD	232	{
1c78217f	233	freq_table_free();
b8488fbe HD	234	clk_put(mpu_clk);
	235	return 0;
	236	}
	237
aeec2990 KH	238	static struct freq_attr *omap_cpufreq_attr[] = {
	239	&cpufreq_freq_attr_scaling_available_freqs,
	240	NULL,
	241	};
	242
ec6bced6 TL	243	static struct cpufreq_driver omap_driver = {
	244	.flags = CPUFREQ_STICKY,
	245	.verify = omap_verify_speed,
	246	.target = omap_target,
	247	.get = omap_getspeed,
	248	.init = omap_cpu_init,
b8488fbe	249	.exit = omap_cpu_exit,
ec6bced6	250	.name = "omap",
aeec2990	251	.attr = omap_cpufreq_attr,
ec6bced6 TL	252	};
	253
	254	static int __init omap_cpufreq_init(void)
	255	{
08ca3e3b NM	256	if (cpu_is_omap24xx())
	257	mpu_clk_name = "virt_prcm_set";
	258	else if (cpu_is_omap34xx())
	259	mpu_clk_name = "dpll1_ck";
	260	else if (cpu_is_omap44xx())
	261	mpu_clk_name = "dpll_mpu_ck";
	262
	263	if (!mpu_clk_name) {
	264	pr_err("%s: unsupported Silicon?\n", __func__);
	265	return -EINVAL;
	266	}
a820ffa8	267
c1b547bc	268	mpu_dev = omap_device_get_by_hwmod_name("mpu");
1bae9958	269	if (IS_ERR(mpu_dev)) {
a820ffa8	270	pr_warning("%s: unable to get the mpu device\n", __func__);
1bae9958	271	return PTR_ERR(mpu_dev);
a820ffa8 NM	272	}
a820ffa8 NM	273
53dfe8a8 KH	274	mpu_reg = regulator_get(mpu_dev, "vcc");
	275	if (IS_ERR(mpu_reg)) {
	276	pr_warning("%s: unable to get MPU regulator\n", __func__);
	277	mpu_reg = NULL;
	278	} else {
	279	/*
	280	* Ensure physical regulator is present.
	281	* (e.g. could be dummy regulator.)
	282	*/
	283	if (regulator_get_voltage(mpu_reg) < 0) {
	284	pr_warn("%s: physical regulator not present for MPU\n",
	285	__func__);
	286	regulator_put(mpu_reg);
	287	mpu_reg = NULL;
	288	}
	289	}
	290
ec6bced6 TL	291	return cpufreq_register_driver(&omap_driver);
	292	}
	293
731e0cc6 SS	294	static void __exit omap_cpufreq_exit(void)
	295	{
	296	cpufreq_unregister_driver(&omap_driver);
	297	}
aeec2990	298
731e0cc6 SS	299	MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
	300	MODULE_LICENSE("GPL");
	301	module_init(omap_cpufreq_init);
	302	module_exit(omap_cpufreq_exit);