drivers/cpufreq/powernow-k6.c - kernel/mindspeed - Git at Google

 /*
  *  This file was based upon code in Powertweak Linux (http://powertweak.sf.net)
  *  (C) 2000-2003  Dave Jones, Arjan van de Ven, Janne Pänkälä,
  *                 Dominik Brodowski.
  *
  *  Licensed under the terms of the GNU GPL License version 2.
  *
  *  BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/cpufreq.h>
 #include <linux/ioport.h>
 #include <linux/timex.h>
 #include <linux/io.h>

 #include <asm/msr.h>

 #define POWERNOW_IOPORT 0xfff0          /* it doesn't matter where, as long
 					   as it is unused */

 #define PFX "powernow-k6: "
 static unsigned int                     busfreq;   /* FSB, in 10 kHz */
 static unsigned int                     max_multiplier;


 /* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */
 static struct cpufreq_frequency_table clock_ratio[] = {
 	{45,  /* 000 -> 4.5x */ 0},
 	{50,  /* 001 -> 5.0x */ 0},
 	{40,  /* 010 -> 4.0x */ 0},
 	{55,  /* 011 -> 5.5x */ 0},
 	{20,  /* 100 -> 2.0x */ 0},
 	{30,  /* 101 -> 3.0x */ 0},
 	{60,  /* 110 -> 6.0x */ 0},
 	{35,  /* 111 -> 3.5x */ 0},
 	{0, CPUFREQ_TABLE_END}
 };


 /**
  * powernow_k6_get_cpu_multiplier - returns the current FSB multiplier
  *
  *   Returns the current setting of the frequency multiplier. Core clock
  * speed is frequency of the Front-Side Bus multiplied with this value.
  */
 static int powernow_k6_get_cpu_multiplier(void)
 {
 	u64 invalue = 0;
 	u32 msrval;

 	msrval = POWERNOW_IOPORT + 0x1;
 	wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
 	invalue = inl(POWERNOW_IOPORT + 0x8);
 	msrval = POWERNOW_IOPORT + 0x0;
 	wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */

 	return clock_ratio[(invalue >> 5)&7].index;
 }


 /**
  * powernow_k6_set_state - set the PowerNow! multiplier
  * @best_i: clock_ratio[best_i] is the target multiplier
  *
  *   Tries to change the PowerNow! multiplier
  */
 static void powernow_k6_set_state(unsigned int best_i)
 {
 	unsigned long outvalue = 0, invalue = 0;
 	unsigned long msrval;
 	struct cpufreq_freqs freqs;

 	if (clock_ratio[best_i].index > max_multiplier) {
 		printk(KERN_ERR PFX "invalid target frequency\n");
 		return;
 	}

 	freqs.old = busfreq * powernow_k6_get_cpu_multiplier();
 	freqs.new = busfreq * clock_ratio[best_i].index;
 	freqs.cpu = 0; /* powernow-k6.c is UP only driver */

 	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

 	/* we now need to transform best_i to the BVC format, see AMD#23446 */

 	outvalue = (1<<12) | (1<<10) | (1<<9) | (best_i<<5);

 	msrval = POWERNOW_IOPORT + 0x1;
 	wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
 	invalue = inl(POWERNOW_IOPORT + 0x8);
 	invalue = invalue & 0xf;
 	outvalue = outvalue | invalue;
 	outl(outvalue , (POWERNOW_IOPORT + 0x8));
 	msrval = POWERNOW_IOPORT + 0x0;
 	wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */

 	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

 	return;
 }


 /**
  * powernow_k6_verify - verifies a new CPUfreq policy
  * @policy: new policy
  *
  * Policy must be within lowest and highest possible CPU Frequency,
  * and at least one possible state must be within min and max.
  */
 static int powernow_k6_verify(struct cpufreq_policy *policy)
 {
 	return cpufreq_frequency_table_verify(policy, &clock_ratio[0]);
 }


 /**
  * powernow_k6_setpolicy - sets a new CPUFreq policy
  * @policy: new policy
  * @target_freq: the target frequency
  * @relation: how that frequency relates to achieved frequency
  *  (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H)
  *
  * sets a new CPUFreq policy
  */
 static int powernow_k6_target(struct cpufreq_policy *policy,
 			       unsigned int target_freq,
 			       unsigned int relation)
 {
 	unsigned int newstate = 0;

 	if (cpufreq_frequency_table_target(policy, &clock_ratio[0],
 				target_freq, relation, &newstate))
 		return -EINVAL;

 	powernow_k6_set_state(newstate);

 	return 0;
 }


 static int powernow_k6_cpu_init(struct cpufreq_policy *policy)
 {
 	unsigned int i, f;
 	int result;

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

 	/* get frequencies */
 	max_multiplier = powernow_k6_get_cpu_multiplier();
 	busfreq = cpu_khz / max_multiplier;

 	/* table init */
 	for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
 		f = clock_ratio[i].index;
 		if (f > max_multiplier)
 			clock_ratio[i].frequency = CPUFREQ_ENTRY_INVALID;
 		else
 			clock_ratio[i].frequency = busfreq * f;
 	}

 	/* cpuinfo and default policy values */
 	policy->cpuinfo.transition_latency = 200000;
 	policy->cur = busfreq * max_multiplier;

 	result = cpufreq_frequency_table_cpuinfo(policy, clock_ratio);
 	if (result)
 		return result;

 	cpufreq_frequency_table_get_attr(clock_ratio, policy->cpu);

 	return 0;
 }


 static int powernow_k6_cpu_exit(struct cpufreq_policy *policy)
 {
 	unsigned int i;
 	for (i = 0; i < 8; i++) {
 		if (i == max_multiplier)
 			powernow_k6_set_state(i);
 	}
 	cpufreq_frequency_table_put_attr(policy->cpu);
 	return 0;
 }

 static unsigned int powernow_k6_get(unsigned int cpu)
 {
 	unsigned int ret;
 	ret = (busfreq * powernow_k6_get_cpu_multiplier());
 	return ret;
 }

 static struct freq_attr *powernow_k6_attr[] = {
 	&cpufreq_freq_attr_scaling_available_freqs,
 	NULL,
 };

 static struct cpufreq_driver powernow_k6_driver = {
 	.verify		= powernow_k6_verify,
 	.target		= powernow_k6_target,
 	.init		= powernow_k6_cpu_init,
 	.exit		= powernow_k6_cpu_exit,
 	.get		= powernow_k6_get,
 	.name		= "powernow-k6",
 	.owner		= THIS_MODULE,
 	.attr		= powernow_k6_attr,
 };


 /**
  * powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver
  *
  *   Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported
  * devices, -EINVAL or -ENOMEM on problems during initiatization, and zero
  * on success.
  */
 static int __init powernow_k6_init(void)
 {
 	struct cpuinfo_x86 *c = &cpu_data(0);

 	if ((c->x86_vendor != X86_VENDOR_AMD) || (c->x86 != 5) ||
 		((c->x86_model != 12) && (c->x86_model != 13)))
 		return -ENODEV;

 	if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) {
 		printk(KERN_INFO PFX "PowerNow IOPORT region already used.\n");
 		return -EIO;
 	}

 	if (cpufreq_register_driver(&powernow_k6_driver)) {
 		release_region(POWERNOW_IOPORT, 16);
 		return -EINVAL;
 	}

 	return 0;
 }


 /**
  * powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support
  *
  *   Unregisters AMD K6-2+ / K6-3+ PowerNow! support.
  */
 static void __exit powernow_k6_exit(void)
 {
 	cpufreq_unregister_driver(&powernow_k6_driver);
 	release_region(POWERNOW_IOPORT, 16);
 }


 MODULE_AUTHOR("Arjan van de Ven, Dave Jones <davej@redhat.com>, "
 		"Dominik Brodowski <linux@brodo.de>");
 MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors.");
 MODULE_LICENSE("GPL");

 module_init(powernow_k6_init);
 module_exit(powernow_k6_exit);
	/*
	* This file was based upon code in Powertweak Linux (http://powertweak.sf.net)
	* (C) 2000-2003 Dave Jones, Arjan van de Ven, Janne Pänkälä,
	* Dominik Brodowski.
	*
	* Licensed under the terms of the GNU GPL License version 2.
	*
	* BIG FAT DISCLAIMER: Work in progress code. Possibly dangerous
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/cpufreq.h>
	#include <linux/ioport.h>
	#include <linux/timex.h>
	#include <linux/io.h>

	#include <asm/msr.h>

	#define POWERNOW_IOPORT 0xfff0 /* it doesn't matter where, as long
	as it is unused */

	#define PFX "powernow-k6: "
	static unsigned int busfreq; /* FSB, in 10 kHz */
	static unsigned int max_multiplier;


	/* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */
	static struct cpufreq_frequency_table clock_ratio[] = {
	{45, /* 000 -> 4.5x */ 0},
	{50, /* 001 -> 5.0x */ 0},
	{40, /* 010 -> 4.0x */ 0},
	{55, /* 011 -> 5.5x */ 0},
	{20, /* 100 -> 2.0x */ 0},
	{30, /* 101 -> 3.0x */ 0},
	{60, /* 110 -> 6.0x */ 0},
	{35, /* 111 -> 3.5x */ 0},
	{0, CPUFREQ_TABLE_END}
	};


	/**
	* powernow_k6_get_cpu_multiplier - returns the current FSB multiplier
	*
	* Returns the current setting of the frequency multiplier. Core clock
	* speed is frequency of the Front-Side Bus multiplied with this value.
	*/
	static int powernow_k6_get_cpu_multiplier(void)
	{
	u64 invalue = 0;
	u32 msrval;

	msrval = POWERNOW_IOPORT + 0x1;
	wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
	invalue = inl(POWERNOW_IOPORT + 0x8);
	msrval = POWERNOW_IOPORT + 0x0;
	wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */

	return clock_ratio[(invalue >> 5)&7].index;
	}


	/**
	* powernow_k6_set_state - set the PowerNow! multiplier
	* @best_i: clock_ratio[best_i] is the target multiplier
	*
	* Tries to change the PowerNow! multiplier
	*/
	static void powernow_k6_set_state(unsigned int best_i)
	{
	unsigned long outvalue = 0, invalue = 0;
	unsigned long msrval;
	struct cpufreq_freqs freqs;

	if (clock_ratio[best_i].index > max_multiplier) {
	printk(KERN_ERR PFX "invalid target frequency\n");
	return;
	}

	freqs.old = busfreq * powernow_k6_get_cpu_multiplier();
	freqs.new = busfreq * clock_ratio[best_i].index;
	freqs.cpu = 0; /* powernow-k6.c is UP only driver */

	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

	/* we now need to transform best_i to the BVC format, see AMD#23446 */

	outvalue = (1<<12) \| (1<<10) \| (1<<9) \| (best_i<<5);

	msrval = POWERNOW_IOPORT + 0x1;
	wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
	invalue = inl(POWERNOW_IOPORT + 0x8);
	invalue = invalue & 0xf;
	outvalue = outvalue \| invalue;
	outl(outvalue , (POWERNOW_IOPORT + 0x8));
	msrval = POWERNOW_IOPORT + 0x0;
	wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */

	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

	return;
	}


	/**
	* powernow_k6_verify - verifies a new CPUfreq policy
	* @policy: new policy
	*
	* Policy must be within lowest and highest possible CPU Frequency,
	* and at least one possible state must be within min and max.
	*/
	static int powernow_k6_verify(struct cpufreq_policy *policy)
	{
	return cpufreq_frequency_table_verify(policy, &clock_ratio[0]);
	}


	/**
	* powernow_k6_setpolicy - sets a new CPUFreq policy
	* @policy: new policy
	* @target_freq: the target frequency
	* @relation: how that frequency relates to achieved frequency
	* (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H)
	*
	* sets a new CPUFreq policy
	*/
	static int powernow_k6_target(struct cpufreq_policy *policy,
	unsigned int target_freq,
	unsigned int relation)
	{
	unsigned int newstate = 0;

	if (cpufreq_frequency_table_target(policy, &clock_ratio[0],
	target_freq, relation, &newstate))
	return -EINVAL;

	powernow_k6_set_state(newstate);

	return 0;
	}


	static int powernow_k6_cpu_init(struct cpufreq_policy *policy)
	{
	unsigned int i, f;
	int result;

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

	/* get frequencies */
	max_multiplier = powernow_k6_get_cpu_multiplier();
	busfreq = cpu_khz / max_multiplier;

	/* table init */
	for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
	f = clock_ratio[i].index;
	if (f > max_multiplier)
	clock_ratio[i].frequency = CPUFREQ_ENTRY_INVALID;
	else
	clock_ratio[i].frequency = busfreq * f;
	}

	/* cpuinfo and default policy values */
	policy->cpuinfo.transition_latency = 200000;
	policy->cur = busfreq * max_multiplier;

	result = cpufreq_frequency_table_cpuinfo(policy, clock_ratio);
	if (result)
	return result;

	cpufreq_frequency_table_get_attr(clock_ratio, policy->cpu);

	return 0;
	}


	static int powernow_k6_cpu_exit(struct cpufreq_policy *policy)
	{
	unsigned int i;
	for (i = 0; i < 8; i++) {
	if (i == max_multiplier)
	powernow_k6_set_state(i);
	}
	cpufreq_frequency_table_put_attr(policy->cpu);
	return 0;
	}

	static unsigned int powernow_k6_get(unsigned int cpu)
	{
	unsigned int ret;
	ret = (busfreq * powernow_k6_get_cpu_multiplier());
	return ret;
	}

	static struct freq_attr *powernow_k6_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	NULL,
	};

	static struct cpufreq_driver powernow_k6_driver = {
	.verify = powernow_k6_verify,
	.target = powernow_k6_target,
	.init = powernow_k6_cpu_init,
	.exit = powernow_k6_cpu_exit,
	.get = powernow_k6_get,
	.name = "powernow-k6",
	.owner = THIS_MODULE,
	.attr = powernow_k6_attr,
	};


	/**
	* powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver
	*
	* Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported
	* devices, -EINVAL or -ENOMEM on problems during initiatization, and zero
	* on success.
	*/
	static int __init powernow_k6_init(void)
	{
	struct cpuinfo_x86 *c = &cpu_data(0);

	if ((c->x86_vendor != X86_VENDOR_AMD) \|\| (c->x86 != 5) \|\|
	((c->x86_model != 12) && (c->x86_model != 13)))
	return -ENODEV;

	if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) {
	printk(KERN_INFO PFX "PowerNow IOPORT region already used.\n");
	return -EIO;
	}

	if (cpufreq_register_driver(&powernow_k6_driver)) {
	release_region(POWERNOW_IOPORT, 16);
	return -EINVAL;
	}

	return 0;
	}


	/**
	* powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support
	*
	* Unregisters AMD K6-2+ / K6-3+ PowerNow! support.
	*/
	static void __exit powernow_k6_exit(void)
	{
	cpufreq_unregister_driver(&powernow_k6_driver);
	release_region(POWERNOW_IOPORT, 16);
	}


	MODULE_AUTHOR("Arjan van de Ven, Dave Jones <davej@redhat.com>, "
	"Dominik Brodowski <linux@brodo.de>");
	MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors.");
	MODULE_LICENSE("GPL");

	module_init(powernow_k6_init);
	module_exit(powernow_k6_exit);