[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / arm / plat-omap / cpu-omap.c

/*
 *  linux/arch/arm/plat-omap/cpu-omap.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
 *
 * 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 <mach/hardware.h>
#include <plat/clock.h>
#include <asm/system.h>

#define VERY_HI_RATE	900000000

static struct cpufreq_frequency_table *freq_table;

#ifdef CONFIG_ARCH_OMAP1
#define MPU_CLK		"mpu"
#else
#define MPU_CLK		"virt_prcm_set"
#endif

static struct clk *mpu_clk;

/* TODO: Add support for SDRAM timing changes */

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;
}

unsigned int omap_getspeed(unsigned int cpu)
{
	unsigned long rate;

	if (cpu)
		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)
{
	struct cpufreq_freqs freqs;
	int ret = 0;

	/* 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(0);
	freqs.new = clk_round_rate(mpu_clk, target_freq * 1000) / 1000;
	freqs.cpu = 0;

	if (freqs.old == freqs.new)
		return ret;

	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
#ifdef CONFIG_CPU_FREQ_DEBUG
	printk(KERN_DEBUG "cpufreq-omap: transition: %u --> %u\n",
	       freqs.old, freqs.new);
#endif
	ret = clk_set_rate(mpu_clk, freqs.new * 1000);
	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

	return ret;
}

static int __init omap_cpu_init(struct cpufreq_policy *policy)
{
	int result = 0;

	mpu_clk = clk_get(NULL, MPU_CLK);
	if (IS_ERR(mpu_clk))
		return PTR_ERR(mpu_clk);

	if (policy->cpu != 0)
		return -EINVAL;

	policy->cur = policy->min = policy->max = omap_getspeed(0);

	clk_init_cpufreq_table(&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;
	}

	/* 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)
{
	return cpufreq_register_driver(&omap_driver);
}

arch_initcall(omap_cpufreq_init);

/*
 * if ever we want to remove this, upon cleanup call:
 *
 * cpufreq_unregister_driver()
 * cpufreq_frequency_table_put_attr()
 */
Commit	Line	Data
ec6bced6 TL	1	/*
	2	* linux/arch/arm/plat-omap/cpu-omap.c
	3	*
	4	* CPU frequency scaling for OMAP
	5	*
	6	* Copyright (C) 2005 Nokia Corporation
	7	* Written by Tony Lindgren <tony@atomide.com>
	8	*
	9	* Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
	10	*
	11	* This program is free software; you can redistribute it and/or modify
	12	* it under the terms of the GNU General Public License version 2 as
	13	* published by the Free Software Foundation.
	14	*/
	15	#include <linux/types.h>
	16	#include <linux/kernel.h>
	17	#include <linux/sched.h>
	18	#include <linux/cpufreq.h>
	19	#include <linux/delay.h>
	20	#include <linux/init.h>
	21	#include <linux/err.h>
f8ce2547	22	#include <linux/clk.h>
fced80c7	23	#include <linux/io.h>
ec6bced6	24
a09e64fb	25	#include <mach/hardware.h>
ce491cf8	26	#include <plat/clock.h>
ec6bced6 TL	27	#include <asm/system.h>
ec6bced6 TL	28
a7ca9d2b TL	29	#define VERY_HI_RATE 900000000
a7ca9d2b TL	30
aeec2990 KH	31	static struct cpufreq_frequency_table *freq_table;
aeec2990 KH	32
a7ca9d2b TL	33	#ifdef CONFIG_ARCH_OMAP1
	34	#define MPU_CLK "mpu"
	35	#else
	36	#define MPU_CLK "virt_prcm_set"
	37	#endif
	38
b8488fbe HD	39	static struct clk *mpu_clk;
b8488fbe HD	40
ec6bced6 TL	41	/* TODO: Add support for SDRAM timing changes */
	42
	43	int omap_verify_speed(struct cpufreq_policy *policy)
	44	{
aeec2990 KH	45	if (freq_table)
	46	return cpufreq_frequency_table_verify(policy, freq_table);
	47
ec6bced6 TL	48	if (policy->cpu)
	49	return -EINVAL;
	50
	51	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
	52	policy->cpuinfo.max_freq);
b8488fbe	53
ec6bced6 TL	54	policy->min = clk_round_rate(mpu_clk, policy->min * 1000) / 1000;
	55	policy->max = clk_round_rate(mpu_clk, policy->max * 1000) / 1000;
	56	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
	57	policy->cpuinfo.max_freq);
ec6bced6 TL	58	return 0;
	59	}
	60
	61	unsigned int omap_getspeed(unsigned int cpu)
	62	{
ec6bced6 TL	63	unsigned long rate;
	64
	65	if (cpu)
	66	return 0;
	67
ec6bced6	68	rate = clk_get_rate(mpu_clk) / 1000;
ec6bced6 TL	69	return rate;
	70	}
	71
	72	static int omap_target(struct cpufreq_policy *policy,
	73	unsigned int target_freq,
	74	unsigned int relation)
	75	{
ec6bced6 TL	76	struct cpufreq_freqs freqs;
	77	int ret = 0;
	78
aeec2990 KH	79	/* Ensure desired rate is within allowed range. Some govenors
aeec2990 KH	80	* (ondemand) will just pass target_freq=0 to get the minimum. */
60c45ae1 EN	81	if (target_freq < policy->min)
	82	target_freq = policy->min;
	83	if (target_freq > policy->max)
	84	target_freq = policy->max;
aeec2990	85
ec6bced6 TL	86	freqs.old = omap_getspeed(0);
	87	freqs.new = clk_round_rate(mpu_clk, target_freq * 1000) / 1000;
	88	freqs.cpu = 0;
	89
aeec2990 KH	90	if (freqs.old == freqs.new)
	91	return ret;
	92
ec6bced6	93	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
aeec2990 KH	94	#ifdef CONFIG_CPU_FREQ_DEBUG
	95	printk(KERN_DEBUG "cpufreq-omap: transition: %u --> %u\n",
	96	freqs.old, freqs.new);
	97	#endif
	98	ret = clk_set_rate(mpu_clk, freqs.new * 1000);
ec6bced6	99	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
ec6bced6 TL	100
	101	return ret;
	102	}
	103
	104	static int __init omap_cpu_init(struct cpufreq_policy *policy)
	105	{
aeec2990 KH	106	int result = 0;
aeec2990 KH	107
a7ca9d2b	108	mpu_clk = clk_get(NULL, MPU_CLK);
ec6bced6 TL	109	if (IS_ERR(mpu_clk))
	110	return PTR_ERR(mpu_clk);
	111
	112	if (policy->cpu != 0)
	113	return -EINVAL;
aeec2990	114
ec6bced6	115	policy->cur = policy->min = policy->max = omap_getspeed(0);
aeec2990 KH	116
	117	clk_init_cpufreq_table(&freq_table);
	118	if (freq_table) {
	119	result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
	120	if (!result)
	121	cpufreq_frequency_table_get_attr(freq_table,
	122	policy->cpu);
	123	} else {
	124	policy->cpuinfo.min_freq = clk_round_rate(mpu_clk, 0) / 1000;
	125	policy->cpuinfo.max_freq = clk_round_rate(mpu_clk,
	126	VERY_HI_RATE) / 1000;
	127	}
	128
	129	/* FIXME: what's the actual transition time? */
b029839c	130	policy->cpuinfo.transition_latency = 300 * 1000;
ec6bced6 TL	131
	132	return 0;
	133	}
	134
b8488fbe HD	135	static int omap_cpu_exit(struct cpufreq_policy *policy)
b8488fbe HD	136	{
4e37c10d	137	clk_exit_cpufreq_table(&freq_table);
b8488fbe HD	138	clk_put(mpu_clk);
	139	return 0;
	140	}
	141
aeec2990 KH	142	static struct freq_attr *omap_cpufreq_attr[] = {
	143	&cpufreq_freq_attr_scaling_available_freqs,
	144	NULL,
	145	};
	146
ec6bced6 TL	147	static struct cpufreq_driver omap_driver = {
	148	.flags = CPUFREQ_STICKY,
	149	.verify = omap_verify_speed,
	150	.target = omap_target,
	151	.get = omap_getspeed,
	152	.init = omap_cpu_init,
b8488fbe	153	.exit = omap_cpu_exit,
ec6bced6	154	.name = "omap",
aeec2990	155	.attr = omap_cpufreq_attr,
ec6bced6 TL	156	};
	157
	158	static int __init omap_cpufreq_init(void)
	159	{
	160	return cpufreq_register_driver(&omap_driver);
	161	}
	162
	163	arch_initcall(omap_cpufreq_init);
aeec2990 KH	164
	165	/*
	166	* if ever we want to remove this, upon cleanup call:
	167	*
	168	* cpufreq_unregister_driver()
	169	* cpufreq_frequency_table_put_attr()
	170	*/
	171