[mirror_ubuntu-artful-kernel.git] / drivers / cpufreq / omap-cpufreq.c

/*
 *  CPU frequency scaling for OMAP
 *
 *  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 <asm/system.h>
#include <asm/smp_plat.h>
#include <asm/cpu.h>

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

#include <mach/hardware.h>

#define VERY_HI_RATE	900000000

#ifdef CONFIG_SMP
struct lpj_info {
	unsigned long	ref;
	unsigned int	freq;
};

static DEFINE_PER_CPU(struct lpj_info, lpj_ref);
static struct lpj_info global_lpj_ref;
#endif

static struct cpufreq_frequency_table *freq_table;
static struct clk *mpu_clk;
static char *mpu_clk_name;
static struct device *mpu_dev;

static int omap_verify_speed(struct cpufreq_policy *policy)
{
	if (freq_table)
		return cpufreq_frequency_table_verify(policy, freq_table);

	if (policy->cpu)
		return -EINVAL;

	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
				     policy->cpuinfo.max_freq);

	policy->min = clk_round_rate(mpu_clk, policy->min * 1000) / 1000;
	policy->max = clk_round_rate(mpu_clk, policy->max * 1000) / 1000;
	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
				     policy->cpuinfo.max_freq);
	return 0;
}

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)
{
	int i, ret = 0;
	struct cpufreq_freqs freqs;

	/* Ensure desired rate is within allowed range.  Some govenors
	 * (ondemand) will just pass target_freq=0 to get the minimum. */
	if (target_freq < policy->min)
		target_freq = policy->min;
	if (target_freq > policy->max)
		target_freq = policy->max;

	freqs.old = omap_getspeed(policy->cpu);
	freqs.new = clk_round_rate(mpu_clk, target_freq * 1000) / 1000;
	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);
	}

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

	ret = clk_set_rate(mpu_clk, freqs.new * 1000);
	freqs.new = omap_getspeed(policy->cpu);

#ifdef CONFIG_SMP
	/*
	 * Note that loops_per_jiffy is not updated on SMP systems in
	 * cpufreq driver. So, update the per-CPU loops_per_jiffy value
	 * on frequency transition. We need to update all dependent CPUs.
	 */
	for_each_cpu(i, policy->cpus) {
		struct lpj_info *lpj = &per_cpu(lpj_ref, i);
		if (!lpj->freq) {
			lpj->ref = per_cpu(cpu_data, i).loops_per_jiffy;
			lpj->freq = freqs.old;
		}

		per_cpu(cpu_data, i).loops_per_jiffy =
			cpufreq_scale(lpj->ref, lpj->freq, freqs.new);
	}

	/* And don't forget to adjust the global one */
	if (!global_lpj_ref.freq) {
		global_lpj_ref.ref = loops_per_jiffy;
		global_lpj_ref.freq = freqs.old;
	}
	loops_per_jiffy = cpufreq_scale(global_lpj_ref.ref, global_lpj_ref.freq,
					freqs.new);
#endif

	/* notifiers */
	for_each_cpu(i, policy->cpus) {
		freqs.cpu = i;
		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	}

	return ret;
}

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)
		return -EINVAL;

	policy->cur = policy->min = policy->max = omap_getspeed(policy->cpu);
	opp_init_cpufreq_table(mpu_dev, &freq_table);

	if (freq_table) {
		result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
		if (!result)
			cpufreq_frequency_table_get_attr(freq_table,
							policy->cpu);
	} else {
		policy->cpuinfo.min_freq = clk_round_rate(mpu_clk, 0) / 1000;
		policy->cpuinfo.max_freq = clk_round_rate(mpu_clk,
							VERY_HI_RATE) / 1000;
	}

	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;
}

static int omap_cpu_exit(struct cpufreq_policy *policy)
{
	clk_exit_cpufreq_table(&freq_table);
	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 = omap2_get_mpuss_device();
	if (!mpu_dev) {
		pr_warning("%s: unable to get the mpu device\n", __func__);
		return -EINVAL;
	}

	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	/*
ec6bced6 TL	2	* CPU frequency scaling for OMAP
	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>
ec6bced6	27
ec6bced6	28	#include <asm/system.h>
731e0cc6	29	#include <asm/smp_plat.h>
46c12216	30	#include <asm/cpu.h>
ec6bced6	31
731e0cc6 SS	32	#include <plat/clock.h>
	33	#include <plat/omap-pm.h>
	34	#include <plat/common.h>
a7ca9d2b	35
731e0cc6	36	#include <mach/hardware.h>
aeec2990	37
731e0cc6	38	#define VERY_HI_RATE 900000000
a7ca9d2b	39
46c12216 RK	40	#ifdef CONFIG_SMP
	41	struct lpj_info {
	42	unsigned long ref;
	43	unsigned int freq;
	44	};
	45
	46	static DEFINE_PER_CPU(struct lpj_info, lpj_ref);
	47	static struct lpj_info global_lpj_ref;
	48	#endif
	49
731e0cc6	50	static struct cpufreq_frequency_table *freq_table;
b8488fbe	51	static struct clk *mpu_clk;
08ca3e3b	52	static char *mpu_clk_name;
a820ffa8	53	static struct device *mpu_dev;
b8488fbe	54
b0a330dc	55	static int omap_verify_speed(struct cpufreq_policy *policy)
ec6bced6	56	{
aeec2990 KH	57	if (freq_table)
	58	return cpufreq_frequency_table_verify(policy, freq_table);
	59
ec6bced6 TL	60	if (policy->cpu)
	61	return -EINVAL;
	62
	63	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
	64	policy->cpuinfo.max_freq);
b8488fbe	65
ec6bced6 TL	66	policy->min = clk_round_rate(mpu_clk, policy->min * 1000) / 1000;
	67	policy->max = clk_round_rate(mpu_clk, policy->max * 1000) / 1000;
	68	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
	69	policy->cpuinfo.max_freq);
ec6bced6 TL	70	return 0;
	71	}
	72
b0a330dc	73	static unsigned int omap_getspeed(unsigned int cpu)
ec6bced6	74	{
ec6bced6 TL	75	unsigned long rate;
ec6bced6 TL	76
46c12216	77	if (cpu >= NR_CPUS)
ec6bced6 TL	78	return 0;
ec6bced6 TL	79
ec6bced6	80	rate = clk_get_rate(mpu_clk) / 1000;
ec6bced6 TL	81	return rate;
	82	}
	83
	84	static int omap_target(struct cpufreq_policy *policy,
	85	unsigned int target_freq,
	86	unsigned int relation)
	87	{
46c12216	88	int i, ret = 0;
731e0cc6	89	struct cpufreq_freqs freqs;
ec6bced6	90
aeec2990 KH	91	/* Ensure desired rate is within allowed range. Some govenors
aeec2990 KH	92	* (ondemand) will just pass target_freq=0 to get the minimum. */
60c45ae1 EN	93	if (target_freq < policy->min)
	94	target_freq = policy->min;
	95	if (target_freq > policy->max)
	96	target_freq = policy->max;
aeec2990	97
46c12216	98	freqs.old = omap_getspeed(policy->cpu);
ec6bced6	99	freqs.new = clk_round_rate(mpu_clk, target_freq * 1000) / 1000;
46c12216	100	freqs.cpu = policy->cpu;
ec6bced6	101
022ac03b	102	if (freqs.old == freqs.new && policy->cur == freqs.new)
aeec2990 KH	103	return ret;
aeec2990 KH	104
46c12216 RK	105	/* notifiers */
	106	for_each_cpu(i, policy->cpus) {
	107	freqs.cpu = i;
	108	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	109	}
731e0cc6	110
aeec2990	111	#ifdef CONFIG_CPU_FREQ_DEBUG
731e0cc6	112	pr_info("cpufreq-omap: transition: %u --> %u\n", freqs.old, freqs.new);
aeec2990	113	#endif
731e0cc6	114
aeec2990	115	ret = clk_set_rate(mpu_clk, freqs.new * 1000);
46c12216 RK	116	freqs.new = omap_getspeed(policy->cpu);
	117
	118	#ifdef CONFIG_SMP
	119	/*
	120	* Note that loops_per_jiffy is not updated on SMP systems in
	121	* cpufreq driver. So, update the per-CPU loops_per_jiffy value
	122	* on frequency transition. We need to update all dependent CPUs.
	123	*/
	124	for_each_cpu(i, policy->cpus) {
	125	struct lpj_info *lpj = &per_cpu(lpj_ref, i);
	126	if (!lpj->freq) {
	127	lpj->ref = per_cpu(cpu_data, i).loops_per_jiffy;
	128	lpj->freq = freqs.old;
	129	}
	130
	131	per_cpu(cpu_data, i).loops_per_jiffy =
	132	cpufreq_scale(lpj->ref, lpj->freq, freqs.new);
	133	}
731e0cc6	134
46c12216 RK	135	/* And don't forget to adjust the global one */
	136	if (!global_lpj_ref.freq) {
	137	global_lpj_ref.ref = loops_per_jiffy;
	138	global_lpj_ref.freq = freqs.old;
	139	}
	140	loops_per_jiffy = cpufreq_scale(global_lpj_ref.ref, global_lpj_ref.freq,
	141	freqs.new);
	142	#endif
	143
	144	/* notifiers */
	145	for_each_cpu(i, policy->cpus) {
	146	freqs.cpu = i;
	147	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	148	}
ec6bced6 TL	149
	150	return ret;
	151	}
	152
790ab7e9	153	static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
ec6bced6	154	{
aeec2990	155	int result = 0;
731e0cc6	156
08ca3e3b	157	mpu_clk = clk_get(NULL, mpu_clk_name);
ec6bced6 TL	158	if (IS_ERR(mpu_clk))
	159	return PTR_ERR(mpu_clk);
	160
46c12216	161	if (policy->cpu >= NR_CPUS)
ec6bced6	162	return -EINVAL;
aeec2990	163
46c12216	164	policy->cur = policy->min = policy->max = omap_getspeed(policy->cpu);
731e0cc6 SS	165	opp_init_cpufreq_table(mpu_dev, &freq_table);
731e0cc6 SS	166
aeec2990 KH	167	if (freq_table) {
	168	result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
	169	if (!result)
	170	cpufreq_frequency_table_get_attr(freq_table,
	171	policy->cpu);
	172	} else {
	173	policy->cpuinfo.min_freq = clk_round_rate(mpu_clk, 0) / 1000;
	174	policy->cpuinfo.max_freq = clk_round_rate(mpu_clk,
	175	VERY_HI_RATE) / 1000;
	176	}
	177
731e0cc6 SS	178	policy->min = policy->cpuinfo.min_freq;
731e0cc6 SS	179	policy->max = policy->cpuinfo.max_freq;
46c12216 RK	180	policy->cur = omap_getspeed(policy->cpu);
	181
	182	/*
	183	* On OMAP SMP configuartion, both processors share the voltage
	184	* and clock. So both CPUs needs to be scaled together and hence
	185	* needs software co-ordination. Use cpufreq affected_cpus
	186	* interface to handle this scenario. Additional is_smp() check
	187	* is to keep SMP_ON_UP build working.
	188	*/
	189	if (is_smp()) {
	190	policy->shared_type = CPUFREQ_SHARED_TYPE_ANY;
ed8ce00c	191	cpumask_setall(policy->cpus);
46c12216	192	}
731e0cc6	193
aeec2990	194	/* FIXME: what's the actual transition time? */
b029839c	195	policy->cpuinfo.transition_latency = 300 * 1000;
ec6bced6 TL	196
	197	return 0;
	198	}
	199
b8488fbe HD	200	static int omap_cpu_exit(struct cpufreq_policy *policy)
b8488fbe HD	201	{
4e37c10d	202	clk_exit_cpufreq_table(&freq_table);
b8488fbe HD	203	clk_put(mpu_clk);
	204	return 0;
	205	}
	206
aeec2990 KH	207	static struct freq_attr *omap_cpufreq_attr[] = {
	208	&cpufreq_freq_attr_scaling_available_freqs,
	209	NULL,
	210	};
	211
ec6bced6 TL	212	static struct cpufreq_driver omap_driver = {
	213	.flags = CPUFREQ_STICKY,
	214	.verify = omap_verify_speed,
	215	.target = omap_target,
	216	.get = omap_getspeed,
	217	.init = omap_cpu_init,
b8488fbe	218	.exit = omap_cpu_exit,
ec6bced6	219	.name = "omap",
aeec2990	220	.attr = omap_cpufreq_attr,
ec6bced6 TL	221	};
	222
	223	static int __init omap_cpufreq_init(void)
	224	{
08ca3e3b NM	225	if (cpu_is_omap24xx())
	226	mpu_clk_name = "virt_prcm_set";
	227	else if (cpu_is_omap34xx())
	228	mpu_clk_name = "dpll1_ck";
	229	else if (cpu_is_omap44xx())
	230	mpu_clk_name = "dpll_mpu_ck";
	231
	232	if (!mpu_clk_name) {
	233	pr_err("%s: unsupported Silicon?\n", __func__);
	234	return -EINVAL;
	235	}
a820ffa8 NM	236
	237	mpu_dev = omap2_get_mpuss_device();
	238	if (!mpu_dev) {
	239	pr_warning("%s: unable to get the mpu device\n", __func__);
	240	return -EINVAL;
	241	}
	242
ec6bced6 TL	243	return cpufreq_register_driver(&omap_driver);
	244	}
	245
731e0cc6 SS	246	static void __exit omap_cpufreq_exit(void)
	247	{
	248	cpufreq_unregister_driver(&omap_driver);
	249	}
aeec2990	250
731e0cc6 SS	251	MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
	252	MODULE_LICENSE("GPL");
	253	module_init(omap_cpufreq_init);
	254	module_exit(omap_cpufreq_exit);