[deliverable/linux.git] / arch / arm / mach-davinci / cpufreq.c

/*
 * CPU frequency scaling for DaVinci
 *
 * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
 *
 * Based on linux/arch/arm/plat-omap/cpu-omap.c. Original Copyright follows:
 *
 *  Copyright (C) 2005 Nokia Corporation
 *  Written by Tony Lindgren <tony@atomide.com>
 *
 *  Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
 *
 * Copyright (C) 2007-2008 Texas Instruments, Inc.
 * Updated to support OMAP3
 * Rajendra Nayak <rnayak@ti.com>
 *
 * 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/cpufreq.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/export.h>

#include <mach/hardware.h>
#include <mach/cpufreq.h>
#include <mach/common.h>

#include "clock.h"

struct davinci_cpufreq {
	struct device *dev;
	struct clk *armclk;
	struct clk *asyncclk;
	unsigned long asyncrate;
};
static struct davinci_cpufreq cpufreq;

static int davinci_verify_speed(struct cpufreq_policy *policy)
{
	struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
	struct cpufreq_frequency_table *freq_table = pdata->freq_table;
	struct clk *armclk = cpufreq.armclk;

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

static unsigned int davinci_getspeed(unsigned int cpu)
{
	if (cpu)
		return 0;

	return clk_get_rate(cpufreq.armclk) / 1000;
}

static int davinci_target(struct cpufreq_policy *policy,
				unsigned int target_freq, unsigned int relation)
{
	int ret = 0;
	unsigned int idx;
	struct cpufreq_freqs freqs;
	struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
	struct clk *armclk = cpufreq.armclk;

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

	freqs.old = davinci_getspeed(0);
	freqs.new = clk_round_rate(armclk, target_freq * 1000) / 1000;
	freqs.cpu = 0;

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

	dev_dbg(cpufreq.dev, "transition: %u --> %u\n", freqs.old, freqs.new);

	ret = cpufreq_frequency_table_target(policy, pdata->freq_table,
						freqs.new, relation, &idx);
	if (ret)
		return -EINVAL;

	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

	/* if moving to higher frequency, up the voltage beforehand */
	if (pdata->set_voltage && freqs.new > freqs.old) {
		ret = pdata->set_voltage(idx);
		if (ret)
			goto out;
	}

	ret = clk_set_rate(armclk, idx);
	if (ret)
		goto out;

	if (cpufreq.asyncclk) {
		ret = clk_set_rate(cpufreq.asyncclk, cpufreq.asyncrate);
		if (ret)
			goto out;
	}

	/* if moving to lower freq, lower the voltage after lowering freq */
	if (pdata->set_voltage && freqs.new < freqs.old)
		pdata->set_voltage(idx);

out:
	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

	return ret;
}

static int davinci_cpu_init(struct cpufreq_policy *policy)
{
	int result = 0;
	struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
	struct cpufreq_frequency_table *freq_table = pdata->freq_table;

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

	/* Finish platform specific initialization */
	if (pdata->init) {
		result = pdata->init();
		if (result)
			return result;
	}

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

	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 = policy->min;
		policy->cpuinfo.max_freq = policy->max;
	}

	policy->min = policy->cpuinfo.min_freq;
	policy->max = policy->cpuinfo.max_freq;
	policy->cur = davinci_getspeed(0);

	/*
	 * Time measurement across the target() function yields ~1500-1800us
	 * time taken with no drivers on notification list.
	 * Setting the latency to 2000 us to accommodate addition of drivers
	 * to pre/post change notification list.
	 */
	policy->cpuinfo.transition_latency = 2000 * 1000;
	return 0;
}

static int davinci_cpu_exit(struct cpufreq_policy *policy)
{
	cpufreq_frequency_table_put_attr(policy->cpu);
	return 0;
}

static struct freq_attr *davinci_cpufreq_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	NULL,
};

static struct cpufreq_driver davinci_driver = {
	.flags		= CPUFREQ_STICKY,
	.verify		= davinci_verify_speed,
	.target		= davinci_target,
	.get		= davinci_getspeed,
	.init		= davinci_cpu_init,
	.exit		= davinci_cpu_exit,
	.name		= "davinci",
	.attr		= davinci_cpufreq_attr,
};

static int __init davinci_cpufreq_probe(struct platform_device *pdev)
{
	struct davinci_cpufreq_config *pdata = pdev->dev.platform_data;
	struct clk *asyncclk;

	if (!pdata)
		return -EINVAL;
	if (!pdata->freq_table)
		return -EINVAL;

	cpufreq.dev = &pdev->dev;

	cpufreq.armclk = clk_get(NULL, "arm");
	if (IS_ERR(cpufreq.armclk)) {
		dev_err(cpufreq.dev, "Unable to get ARM clock\n");
		return PTR_ERR(cpufreq.armclk);
	}

	asyncclk = clk_get(cpufreq.dev, "async");
	if (!IS_ERR(asyncclk)) {
		cpufreq.asyncclk = asyncclk;
		cpufreq.asyncrate = clk_get_rate(asyncclk);
	}

	return cpufreq_register_driver(&davinci_driver);
}

static int __exit davinci_cpufreq_remove(struct platform_device *pdev)
{
	clk_put(cpufreq.armclk);

	if (cpufreq.asyncclk)
		clk_put(cpufreq.asyncclk);

	return cpufreq_unregister_driver(&davinci_driver);
}

static struct platform_driver davinci_cpufreq_driver = {
	.driver = {
		.name	 = "cpufreq-davinci",
		.owner	 = THIS_MODULE,
	},
	.remove = __exit_p(davinci_cpufreq_remove),
};

int __init davinci_cpufreq_init(void)
{
	return platform_driver_probe(&davinci_cpufreq_driver,
							davinci_cpufreq_probe);
}
Commit	Line	Data
6601b803 SN	1	/*
	2	* CPU frequency scaling for DaVinci
	3	*
	4	* Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
	5	*
	6	* Based on linux/arch/arm/plat-omap/cpu-omap.c. Original Copyright follows:
	7	*
	8	* Copyright (C) 2005 Nokia Corporation
	9	* Written by Tony Lindgren <tony@atomide.com>
	10	*
	11	* Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
	12	*
	13	* Copyright (C) 2007-2008 Texas Instruments, Inc.
	14	* Updated to support OMAP3
	15	* Rajendra Nayak <rnayak@ti.com>
	16	*
	17	* This program is free software; you can redistribute it and/or modify
	18	* it under the terms of the GNU General Public License version 2 as
	19	* published by the Free Software Foundation.
	20	*/
	21	#include <linux/types.h>
	22	#include <linux/cpufreq.h>
	23	#include <linux/init.h>
	24	#include <linux/err.h>
	25	#include <linux/clk.h>
	26	#include <linux/platform_device.h>
dc28094b	27	#include <linux/export.h>
6601b803 SN	28
	29	#include <mach/hardware.h>
	30	#include <mach/cpufreq.h>
	31	#include <mach/common.h>
	32
	33	#include "clock.h"
	34
	35	struct davinci_cpufreq {
	36	struct device *dev;
	37	struct clk *armclk;
30a2c5d2 SN	38	struct clk *asyncclk;
30a2c5d2 SN	39	unsigned long asyncrate;
6601b803 SN	40	};
	41	static struct davinci_cpufreq cpufreq;
	42
	43	static int davinci_verify_speed(struct cpufreq_policy *policy)
	44	{
	45	struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
	46	struct cpufreq_frequency_table *freq_table = pdata->freq_table;
	47	struct clk *armclk = cpufreq.armclk;
	48
	49	if (freq_table)
	50	return cpufreq_frequency_table_verify(policy, freq_table);
	51
	52	if (policy->cpu)
	53	return -EINVAL;
	54
	55	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
	56	policy->cpuinfo.max_freq);
	57
	58	policy->min = clk_round_rate(armclk, policy->min * 1000) / 1000;
	59	policy->max = clk_round_rate(armclk, policy->max * 1000) / 1000;
	60	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
	61	policy->cpuinfo.max_freq);
	62	return 0;
	63	}
	64
	65	static unsigned int davinci_getspeed(unsigned int cpu)
	66	{
	67	if (cpu)
	68	return 0;
	69
	70	return clk_get_rate(cpufreq.armclk) / 1000;
	71	}
	72
	73	static int davinci_target(struct cpufreq_policy *policy,
	74	unsigned int target_freq, unsigned int relation)
	75	{
	76	int ret = 0;
	77	unsigned int idx;
	78	struct cpufreq_freqs freqs;
	79	struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
	80	struct clk *armclk = cpufreq.armclk;
	81
	82	/*
	83	* Ensure desired rate is within allowed range. Some govenors
	84	* (ondemand) will just pass target_freq=0 to get the minimum.
	85	*/
	86	if (target_freq < policy->cpuinfo.min_freq)
	87	target_freq = policy->cpuinfo.min_freq;
	88	if (target_freq > policy->cpuinfo.max_freq)
	89	target_freq = policy->cpuinfo.max_freq;
	90
	91	freqs.old = davinci_getspeed(0);
	92	freqs.new = clk_round_rate(armclk, target_freq * 1000) / 1000;
	93	freqs.cpu = 0;
	94
	95	if (freqs.old == freqs.new)
	96	return ret;
	97
d870df68	98	dev_dbg(cpufreq.dev, "transition: %u --> %u\n", freqs.old, freqs.new);
6601b803 SN	99
	100	ret = cpufreq_frequency_table_target(policy, pdata->freq_table,
	101	freqs.new, relation, &idx);
	102	if (ret)
	103	return -EINVAL;
	104
	105	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	106
	107	/* if moving to higher frequency, up the voltage beforehand */
fca97b33 SN	108	if (pdata->set_voltage && freqs.new > freqs.old) {
	109	ret = pdata->set_voltage(idx);
	110	if (ret)
	111	goto out;
	112	}
6601b803 SN	113
6601b803 SN	114	ret = clk_set_rate(armclk, idx);
fca97b33 SN	115	if (ret)
fca97b33 SN	116	goto out;
6601b803	117
30a2c5d2 SN	118	if (cpufreq.asyncclk) {
	119	ret = clk_set_rate(cpufreq.asyncclk, cpufreq.asyncrate);
	120	if (ret)
	121	goto out;
	122	}
	123
6601b803 SN	124	/* if moving to lower freq, lower the voltage after lowering freq */
	125	if (pdata->set_voltage && freqs.new < freqs.old)
	126	pdata->set_voltage(idx);
	127
fca97b33	128	out:
6601b803 SN	129	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	130
	131	return ret;
	132	}
	133
079db590	134	static int davinci_cpu_init(struct cpufreq_policy *policy)
6601b803 SN	135	{
	136	int result = 0;
	137	struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
	138	struct cpufreq_frequency_table *freq_table = pdata->freq_table;
	139
	140	if (policy->cpu != 0)
	141	return -EINVAL;
	142
13d5e27a SN	143	/* Finish platform specific initialization */
	144	if (pdata->init) {
	145	result = pdata->init();
	146	if (result)
	147	return result;
	148	}
	149
6601b803 SN	150	policy->cur = policy->min = policy->max = davinci_getspeed(0);
	151
	152	if (freq_table) {
	153	result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
	154	if (!result)
	155	cpufreq_frequency_table_get_attr(freq_table,
	156	policy->cpu);
	157	} else {
	158	policy->cpuinfo.min_freq = policy->min;
	159	policy->cpuinfo.max_freq = policy->max;
	160	}
	161
	162	policy->min = policy->cpuinfo.min_freq;
	163	policy->max = policy->cpuinfo.max_freq;
	164	policy->cur = davinci_getspeed(0);
	165
	166	/*
	167	* Time measurement across the target() function yields ~1500-1800us
	168	* time taken with no drivers on notification list.
25985edc	169	* Setting the latency to 2000 us to accommodate addition of drivers
6601b803 SN	170	* to pre/post change notification list.
	171	*/
	172	policy->cpuinfo.transition_latency = 2000 * 1000;
	173	return 0;
	174	}
	175
	176	static int davinci_cpu_exit(struct cpufreq_policy *policy)
	177	{
	178	cpufreq_frequency_table_put_attr(policy->cpu);
	179	return 0;
	180	}
	181
	182	static struct freq_attr *davinci_cpufreq_attr[] = {
	183	&cpufreq_freq_attr_scaling_available_freqs,
	184	NULL,
	185	};
	186
	187	static struct cpufreq_driver davinci_driver = {
	188	.flags = CPUFREQ_STICKY,
	189	.verify = davinci_verify_speed,
	190	.target = davinci_target,
	191	.get = davinci_getspeed,
	192	.init = davinci_cpu_init,
	193	.exit = davinci_cpu_exit,
	194	.name = "davinci",
	195	.attr = davinci_cpufreq_attr,
	196	};
	197
	198	static int __init davinci_cpufreq_probe(struct platform_device *pdev)
	199	{
	200	struct davinci_cpufreq_config *pdata = pdev->dev.platform_data;
30a2c5d2	201	struct clk *asyncclk;
6601b803 SN	202
	203	if (!pdata)
	204	return -EINVAL;
	205	if (!pdata->freq_table)
	206	return -EINVAL;
	207
	208	cpufreq.dev = &pdev->dev;
	209
	210	cpufreq.armclk = clk_get(NULL, "arm");
	211	if (IS_ERR(cpufreq.armclk)) {
	212	dev_err(cpufreq.dev, "Unable to get ARM clock\n");
	213	return PTR_ERR(cpufreq.armclk);
	214	}
	215
30a2c5d2 SN	216	asyncclk = clk_get(cpufreq.dev, "async");
	217	if (!IS_ERR(asyncclk)) {
	218	cpufreq.asyncclk = asyncclk;
	219	cpufreq.asyncrate = clk_get_rate(asyncclk);
	220	}
	221
6601b803 SN	222	return cpufreq_register_driver(&davinci_driver);
	223	}
	224
	225	static int __exit davinci_cpufreq_remove(struct platform_device *pdev)
	226	{
	227	clk_put(cpufreq.armclk);
	228
30a2c5d2 SN	229	if (cpufreq.asyncclk)
	230	clk_put(cpufreq.asyncclk);
	231
6601b803 SN	232	return cpufreq_unregister_driver(&davinci_driver);
	233	}
	234
	235	static struct platform_driver davinci_cpufreq_driver = {
	236	.driver = {
	237	.name = "cpufreq-davinci",
	238	.owner = THIS_MODULE,
	239	},
	240	.remove = __exit_p(davinci_cpufreq_remove),
	241	};
	242
3aa3e840	243	int __init davinci_cpufreq_init(void)
6601b803 SN	244	{
	245	return platform_driver_probe(&davinci_cpufreq_driver,
	246	davinci_cpufreq_probe);
	247	}
6601b803	248