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

#include "clock.h"

struct davinci_cpufreq {
	struct device *dev;
	struct clk *armclk;
};
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;

	cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER,
			dev_driver_string(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 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 __init 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 accomodate 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;

	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);
	}

	return cpufreq_register_driver(&davinci_driver);
}

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

	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),
};

static int __init davinci_cpufreq_init(void)
{
	return platform_driver_probe(&davinci_cpufreq_driver,
							davinci_cpufreq_probe);
}
late_initcall(davinci_cpufreq_init);
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>
	27
	28	#include <mach/hardware.h>
	29	#include <mach/cpufreq.h>
	30	#include <mach/common.h>
	31
	32	#include "clock.h"
	33
	34	struct davinci_cpufreq {
	35	struct device *dev;
	36	struct clk *armclk;
	37	};
	38	static struct davinci_cpufreq cpufreq;
	39
	40	static int davinci_verify_speed(struct cpufreq_policy *policy)
	41	{
	42	struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
	43	struct cpufreq_frequency_table *freq_table = pdata->freq_table;
	44	struct clk *armclk = cpufreq.armclk;
	45
	46	if (freq_table)
	47	return cpufreq_frequency_table_verify(policy, freq_table);
	48
	49	if (policy->cpu)
	50	return -EINVAL;
	51
	52	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
	53	policy->cpuinfo.max_freq);
	54
	55	policy->min = clk_round_rate(armclk, policy->min * 1000) / 1000;
	56	policy->max = clk_round_rate(armclk, policy->max * 1000) / 1000;
	57	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
	58	policy->cpuinfo.max_freq);
	59	return 0;
	60	}
	61
	62	static unsigned int davinci_getspeed(unsigned int cpu)
	63	{
	64	if (cpu)
65	return 0;
66
67	return clk_get_rate(cpufreq.armclk) / 1000;
68	}
69
70	static int davinci_target(struct cpufreq_policy *policy,
71	unsigned int target_freq, unsigned int relation)
72	{
73	int ret = 0;
74	unsigned int idx;
75	struct cpufreq_freqs freqs;
76	struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
77	struct clk *armclk = cpufreq.armclk;
78
79	/*
80	* Ensure desired rate is within allowed range. Some govenors
81	* (ondemand) will just pass target_freq=0 to get the minimum.
82	*/
83	if (target_freq < policy->cpuinfo.min_freq)
84	target_freq = policy->cpuinfo.min_freq;
85	if (target_freq > policy->cpuinfo.max_freq)
86	target_freq = policy->cpuinfo.max_freq;
87
88	freqs.old = davinci_getspeed(0);
89	freqs.new = clk_round_rate(armclk, target_freq * 1000) / 1000;
90	freqs.cpu = 0;
91
92	if (freqs.old == freqs.new)
93	return ret;
94
95	cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER,
96	dev_driver_string(cpufreq.dev),
97	"transition: %u --> %u\n", freqs.old, freqs.new);
98
99	ret = cpufreq_frequency_table_target(policy, pdata->freq_table,
100	freqs.new, relation, &idx);
101	if (ret)
102	return -EINVAL;
103
104	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
105
106	/* if moving to higher frequency, up the voltage beforehand */
fca97b33 SN	107	if (pdata->set_voltage && freqs.new > freqs.old) {
	108	ret = pdata->set_voltage(idx);
	109	if (ret)
	110	goto out;
	111	}
6601b803 SN	112
6601b803 SN	113	ret = clk_set_rate(armclk, idx);
fca97b33 SN	114	if (ret)
fca97b33 SN	115	goto out;
6601b803 SN	116
	117	/* if moving to lower freq, lower the voltage after lowering freq */
	118	if (pdata->set_voltage && freqs.new < freqs.old)
	119	pdata->set_voltage(idx);
	120
fca97b33	121	out:
6601b803 SN	122	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	123
	124	return ret;
	125	}
	126
	127	static int __init davinci_cpu_init(struct cpufreq_policy *policy)
	128	{
	129	int result = 0;
	130	struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
	131	struct cpufreq_frequency_table *freq_table = pdata->freq_table;
	132
	133	if (policy->cpu != 0)
	134	return -EINVAL;
	135
13d5e27a SN	136	/* Finish platform specific initialization */
	137	if (pdata->init) {
	138	result = pdata->init();
	139	if (result)
	140	return result;
	141	}
	142
6601b803 SN	143	policy->cur = policy->min = policy->max = davinci_getspeed(0);
	144
	145	if (freq_table) {
	146	result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
	147	if (!result)
	148	cpufreq_frequency_table_get_attr(freq_table,
	149	policy->cpu);
	150	} else {
	151	policy->cpuinfo.min_freq = policy->min;
	152	policy->cpuinfo.max_freq = policy->max;
	153	}
	154
	155	policy->min = policy->cpuinfo.min_freq;
	156	policy->max = policy->cpuinfo.max_freq;
	157	policy->cur = davinci_getspeed(0);
	158
	159	/*
	160	* Time measurement across the target() function yields ~1500-1800us
	161	* time taken with no drivers on notification list.
	162	* Setting the latency to 2000 us to accomodate addition of drivers
	163	* to pre/post change notification list.
	164	*/
	165	policy->cpuinfo.transition_latency = 2000 * 1000;
	166	return 0;
	167	}
	168
	169	static int davinci_cpu_exit(struct cpufreq_policy *policy)
	170	{
	171	cpufreq_frequency_table_put_attr(policy->cpu);
	172	return 0;
	173	}
	174
	175	static struct freq_attr *davinci_cpufreq_attr[] = {
	176	&cpufreq_freq_attr_scaling_available_freqs,
	177	NULL,
	178	};
	179
	180	static struct cpufreq_driver davinci_driver = {
	181	.flags = CPUFREQ_STICKY,
	182	.verify = davinci_verify_speed,
	183	.target = davinci_target,
	184	.get = davinci_getspeed,
	185	.init = davinci_cpu_init,
	186	.exit = davinci_cpu_exit,
	187	.name = "davinci",
	188	.attr = davinci_cpufreq_attr,
	189	};
	190
	191	static int __init davinci_cpufreq_probe(struct platform_device *pdev)
	192	{
	193	struct davinci_cpufreq_config *pdata = pdev->dev.platform_data;
	194
	195	if (!pdata)
	196	return -EINVAL;
	197	if (!pdata->freq_table)
	198	return -EINVAL;
	199
	200	cpufreq.dev = &pdev->dev;
	201
	202	cpufreq.armclk = clk_get(NULL, "arm");
	203	if (IS_ERR(cpufreq.armclk)) {
	204	dev_err(cpufreq.dev, "Unable to get ARM clock\n");
	205	return PTR_ERR(cpufreq.armclk);
	206	}
207
208	return cpufreq_register_driver(&davinci_driver);
209	}
210
211	static int __exit davinci_cpufreq_remove(struct platform_device *pdev)
212	{
213	clk_put(cpufreq.armclk);
214
215	return cpufreq_unregister_driver(&davinci_driver);
216	}
217
218	static struct platform_driver davinci_cpufreq_driver = {
219	.driver = {
220	.name = "cpufreq-davinci",
221	.owner = THIS_MODULE,
222	},
223	.remove = __exit_p(davinci_cpufreq_remove),
224	};
225
226	static int __init davinci_cpufreq_init(void)
227	{
228	return platform_driver_probe(&davinci_cpufreq_driver,
229	davinci_cpufreq_probe);
230	}
231	late_initcall(davinci_cpufreq_init);
232