[mirror_ubuntu-artful-kernel.git] / arch / avr32 / mach-at32ap / cpufreq.c

/*
 * Copyright (C) 2004-2007 Atmel Corporation
 *
 * Based on MIPS implementation arch/mips/kernel/time.c
 *   Copyright 2001 MontaVista Software Inc.
 *
 * 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.
 */

/*#define DEBUG*/

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/export.h>
#include <asm/system.h>

static struct clk *cpuclk;

static int at32_verify_speed(struct cpufreq_policy *policy)
{
	if (policy->cpu != 0)
		return -EINVAL;

	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
			policy->cpuinfo.max_freq);
	return 0;
}

static unsigned int at32_get_speed(unsigned int cpu)
{
	/* No SMP support */
	if (cpu)
		return 0;
	return (unsigned int)((clk_get_rate(cpuclk) + 500) / 1000);
}

static unsigned int	ref_freq;
static unsigned long	loops_per_jiffy_ref;

static int at32_set_target(struct cpufreq_policy *policy,
			  unsigned int target_freq,
			  unsigned int relation)
{
	struct cpufreq_freqs freqs;
	long freq;

	/* Convert target_freq from kHz to Hz */
	freq = clk_round_rate(cpuclk, target_freq * 1000);

	/* Check if policy->min <= new_freq <= policy->max */
	if(freq < (policy->min * 1000) || freq > (policy->max * 1000))
		return -EINVAL;

	pr_debug("cpufreq: requested frequency %u Hz\n", target_freq * 1000);

	freqs.old = at32_get_speed(0);
	freqs.new = (freq + 500) / 1000;
	freqs.cpu = 0;
	freqs.flags = 0;

	if (!ref_freq) {
		ref_freq = freqs.old;
		loops_per_jiffy_ref = boot_cpu_data.loops_per_jiffy;
	}

	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	if (freqs.old < freqs.new)
		boot_cpu_data.loops_per_jiffy = cpufreq_scale(
				loops_per_jiffy_ref, ref_freq, freqs.new);
	clk_set_rate(cpuclk, freq);
	if (freqs.new < freqs.old)
		boot_cpu_data.loops_per_jiffy = cpufreq_scale(
				loops_per_jiffy_ref, ref_freq, freqs.new);
	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

	pr_debug("cpufreq: set frequency %lu Hz\n", freq);

	return 0;
}

static int __init at32_cpufreq_driver_init(struct cpufreq_policy *policy)
{
	if (policy->cpu != 0)
		return -EINVAL;

	cpuclk = clk_get(NULL, "cpu");
	if (IS_ERR(cpuclk)) {
		pr_debug("cpufreq: could not get CPU clk\n");
		return PTR_ERR(cpuclk);
	}

	policy->cpuinfo.min_freq = (clk_round_rate(cpuclk, 1) + 500) / 1000;
	policy->cpuinfo.max_freq = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
	policy->cpuinfo.transition_latency = 0;
	policy->cur = at32_get_speed(0);
	policy->min = policy->cpuinfo.min_freq;
	policy->max = policy->cpuinfo.max_freq;

	printk("cpufreq: AT32AP CPU frequency driver\n");

	return 0;
}

static struct cpufreq_driver at32_driver = {
	.name		= "at32ap",
	.owner		= THIS_MODULE,
	.init		= at32_cpufreq_driver_init,
	.verify		= at32_verify_speed,
	.target		= at32_set_target,
	.get		= at32_get_speed,
	.flags		= CPUFREQ_STICKY,
};

static int __init at32_cpufreq_init(void)
{
	return cpufreq_register_driver(&at32_driver);
}
late_initcall(at32_cpufreq_init);
Commit	Line	Data
9e58e185 HCE	1	/*
	2	* Copyright (C) 2004-2007 Atmel Corporation
	3	*
	4	* Based on MIPS implementation arch/mips/kernel/time.c
	5	* Copyright 2001 MontaVista Software Inc.
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11
	12	/#define DEBUG/
	13
	14	#include <linux/kernel.h>
	15	#include <linux/types.h>
	16	#include <linux/init.h>
	17	#include <linux/cpufreq.h>
	18	#include <linux/io.h>
	19	#include <linux/clk.h>
	20	#include <linux/err.h>
09cf6a29	21	#include <linux/export.h>
9e58e185 HCE	22	#include <asm/system.h>
	23
	24	static struct clk *cpuclk;
	25
	26	static int at32_verify_speed(struct cpufreq_policy *policy)
	27	{
	28	if (policy->cpu != 0)
	29	return -EINVAL;
	30
	31	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
	32	policy->cpuinfo.max_freq);
	33	return 0;
	34	}
	35
	36	static unsigned int at32_get_speed(unsigned int cpu)
	37	{
	38	/* No SMP support */
	39	if (cpu)
	40	return 0;
	41	return (unsigned int)((clk_get_rate(cpuclk) + 500) / 1000);
	42	}
	43
e3f91ca4 HS	44	static unsigned int ref_freq;
	45	static unsigned long loops_per_jiffy_ref;
	46
9e58e185 HCE	47	static int at32_set_target(struct cpufreq_policy *policy,
	48	unsigned int target_freq,
	49	unsigned int relation)
	50	{
	51	struct cpufreq_freqs freqs;
	52	long freq;
	53
	54	/* Convert target_freq from kHz to Hz */
	55	freq = clk_round_rate(cpuclk, target_freq * 1000);
	56
	57	/* Check if policy->min <= new_freq <= policy->max */
	58	if(freq < (policy->min * 1000) \|\| freq > (policy->max * 1000))
	59	return -EINVAL;
	60
	61	pr_debug("cpufreq: requested frequency %u Hz\n", target_freq * 1000);
	62
	63	freqs.old = at32_get_speed(0);
	64	freqs.new = (freq + 500) / 1000;
	65	freqs.cpu = 0;
	66	freqs.flags = 0;
	67
e3f91ca4 HS	68	if (!ref_freq) {
	69	ref_freq = freqs.old;
	70	loops_per_jiffy_ref = boot_cpu_data.loops_per_jiffy;
	71	}
	72
9e58e185	73	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
e3f91ca4 HS	74	if (freqs.old < freqs.new)
	75	boot_cpu_data.loops_per_jiffy = cpufreq_scale(
	76	loops_per_jiffy_ref, ref_freq, freqs.new);
9e58e185	77	clk_set_rate(cpuclk, freq);
e3f91ca4 HS	78	if (freqs.new < freqs.old)
	79	boot_cpu_data.loops_per_jiffy = cpufreq_scale(
	80	loops_per_jiffy_ref, ref_freq, freqs.new);
9e58e185 HCE	81	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	82
	83	pr_debug("cpufreq: set frequency %lu Hz\n", freq);
	84
	85	return 0;
	86	}
	87
	88	static int __init at32_cpufreq_driver_init(struct cpufreq_policy *policy)
	89	{
	90	if (policy->cpu != 0)
	91	return -EINVAL;
	92
	93	cpuclk = clk_get(NULL, "cpu");
	94	if (IS_ERR(cpuclk)) {
	95	pr_debug("cpufreq: could not get CPU clk\n");
	96	return PTR_ERR(cpuclk);
	97	}
	98
	99	policy->cpuinfo.min_freq = (clk_round_rate(cpuclk, 1) + 500) / 1000;
	100	policy->cpuinfo.max_freq = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
	101	policy->cpuinfo.transition_latency = 0;
	102	policy->cur = at32_get_speed(0);
	103	policy->min = policy->cpuinfo.min_freq;
	104	policy->max = policy->cpuinfo.max_freq;
9e58e185 HCE	105
	106	printk("cpufreq: AT32AP CPU frequency driver\n");
	107
	108	return 0;
	109	}
	110
	111	static struct cpufreq_driver at32_driver = {
	112	.name = "at32ap",
	113	.owner = THIS_MODULE,
	114	.init = at32_cpufreq_driver_init,
	115	.verify = at32_verify_speed,
	116	.target = at32_set_target,
	117	.get = at32_get_speed,
	118	.flags = CPUFREQ_STICKY,
	119	};
	120
	121	static int __init at32_cpufreq_init(void)
	122	{
	123	return cpufreq_register_driver(&at32_driver);
	124	}
f04d264a	125	late_initcall(at32_cpufreq_init);