[mirror_ubuntu-hirsute-kernel.git] / drivers / cpufreq / powernow-k6.c

/*
 *  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/cpu_device_id.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].driver_data;
}


/**
 * 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(struct cpufreq_policy *policy,
		unsigned int best_i)
{
	unsigned long outvalue = 0, invalue = 0;
	unsigned long msrval;
	struct cpufreq_freqs freqs;

	if (clock_ratio[best_i].driver_data > 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].driver_data;

	cpufreq_notify_transition(policy, &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(policy, &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(policy, newstate);

	return 0;
}


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

	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].driver_data;
		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;

	return cpufreq_table_validate_and_show(policy, clock_ratio);
}


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(policy, 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",
	.attr		= powernow_k6_attr,
};

static const struct x86_cpu_id powernow_k6_ids[] = {
	{ X86_VENDOR_AMD, 5, 12 },
	{ X86_VENDOR_AMD, 5, 13 },
	{}
};
MODULE_DEVICE_TABLE(x86cpu, powernow_k6_ids);

/**
 * 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)
{
	if (!x86_match_cpu(powernow_k6_ids))
		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);
Commit	Line	Data
1da177e4 LT	1	/*
1da177e4 LT	2	* This file was based upon code in Powertweak Linux (http://powertweak.sf.net)
14a6650f DJ	3	* (C) 2000-2003 Dave Jones, Arjan van de Ven, Janne Pänkälä,
14a6650f DJ	4	* Dominik Brodowski.
1da177e4 LT	5	*
	6	* Licensed under the terms of the GNU GPL License version 2.
	7	*
	8	* BIG FAT DISCLAIMER: Work in progress code. Possibly dangerous
	9	*/
	10
	11	#include <linux/kernel.h>
32ee8c3e	12	#include <linux/module.h>
1da177e4 LT	13	#include <linux/init.h>
	14	#include <linux/cpufreq.h>
	15	#include <linux/ioport.h>
8d2d2051 PC	16	#include <linux/timex.h>
8d2d2051 PC	17	#include <linux/io.h>
1da177e4	18
fa8031ae	19	#include <asm/cpu_device_id.h>
14a6650f DJ	20	#include <asm/msr.h>
14a6650f DJ	21
8d2d2051 PC	22	#define POWERNOW_IOPORT 0xfff0 /* it doesn't matter where, as long
8d2d2051 PC	23	as it is unused */
1da177e4	24
14a6650f	25	#define PFX "powernow-k6: "
1da177e4 LT	26	static unsigned int busfreq; /* FSB, in 10 kHz */
	27	static unsigned int max_multiplier;
	28
	29
	30	/* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */
	31	static struct cpufreq_frequency_table clock_ratio[] = {
	32	{45, /* 000 -> 4.5x */ 0},
	33	{50, /* 001 -> 5.0x */ 0},
	34	{40, /* 010 -> 4.0x */ 0},
	35	{55, /* 011 -> 5.5x */ 0},
	36	{20, /* 100 -> 2.0x */ 0},
	37	{30, /* 101 -> 3.0x */ 0},
	38	{60, /* 110 -> 6.0x */ 0},
	39	{35, /* 111 -> 3.5x */ 0},
	40	{0, CPUFREQ_TABLE_END}
	41	};
	42
	43
	44	/**
	45	* powernow_k6_get_cpu_multiplier - returns the current FSB multiplier
	46	*
	47	* Returns the current setting of the frequency multiplier. Core clock
	48	* speed is frequency of the Front-Side Bus multiplied with this value.
	49	*/
	50	static int powernow_k6_get_cpu_multiplier(void)
	51	{
14a6650f DJ	52	u64 invalue = 0;
14a6650f DJ	53	u32 msrval;
32ee8c3e	54
1da177e4 LT	55	msrval = POWERNOW_IOPORT + 0x1;
1da177e4 LT	56	wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
8d2d2051	57	invalue = inl(POWERNOW_IOPORT + 0x8);
1da177e4 LT	58	msrval = POWERNOW_IOPORT + 0x0;
	59	wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
	60
50701588	61	return clock_ratio[(invalue >> 5)&7].driver_data;
1da177e4 LT	62	}
	63
	64
	65	/**
	66	* powernow_k6_set_state - set the PowerNow! multiplier
	67	* @best_i: clock_ratio[best_i] is the target multiplier
	68	*
	69	* Tries to change the PowerNow! multiplier
	70	*/
b43a7ffb VK	71	static void powernow_k6_set_state(struct cpufreq_policy *policy,
b43a7ffb VK	72	unsigned int best_i)
1da177e4	73	{
14a6650f DJ	74	unsigned long outvalue = 0, invalue = 0;
	75	unsigned long msrval;
	76	struct cpufreq_freqs freqs;
1da177e4	77
50701588	78	if (clock_ratio[best_i].driver_data > max_multiplier) {
14a6650f	79	printk(KERN_ERR PFX "invalid target frequency\n");
1da177e4 LT	80	return;
	81	}
	82
	83	freqs.old = busfreq * powernow_k6_get_cpu_multiplier();
50701588	84	freqs.new = busfreq * clock_ratio[best_i].driver_data;
32ee8c3e	85
b43a7ffb	86	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
1da177e4 LT	87
	88	/* we now need to transform best_i to the BVC format, see AMD#23446 */
	89
	90	outvalue = (1<<12) \| (1<<10) \| (1<<9) \| (best_i<<5);
	91
	92	msrval = POWERNOW_IOPORT + 0x1;
	93	wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
8d2d2051	94	invalue = inl(POWERNOW_IOPORT + 0x8);
1da177e4 LT	95	invalue = invalue & 0xf;
1da177e4 LT	96	outvalue = outvalue \| invalue;
8d2d2051	97	outl(outvalue , (POWERNOW_IOPORT + 0x8));
1da177e4 LT	98	msrval = POWERNOW_IOPORT + 0x0;
	99	wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
	100
b43a7ffb	101	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
1da177e4 LT	102
	103	return;
	104	}
	105
	106
	107	/**
	108	* powernow_k6_verify - verifies a new CPUfreq policy
	109	* @policy: new policy
	110	*
	111	* Policy must be within lowest and highest possible CPU Frequency,
	112	* and at least one possible state must be within min and max.
	113	*/
	114	static int powernow_k6_verify(struct cpufreq_policy *policy)
	115	{
	116	return cpufreq_frequency_table_verify(policy, &clock_ratio[0]);
	117	}
	118
	119
	120	/**
	121	* powernow_k6_setpolicy - sets a new CPUFreq policy
	122	* @policy: new policy
	123	* @target_freq: the target frequency
14a6650f DJ	124	* @relation: how that frequency relates to achieved frequency
14a6650f DJ	125	* (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H)
1da177e4 LT	126	*
	127	* sets a new CPUFreq policy
	128	*/
8d2d2051	129	static int powernow_k6_target(struct cpufreq_policy *policy,
1da177e4 LT	130	unsigned int target_freq,
	131	unsigned int relation)
	132	{
14a6650f	133	unsigned int newstate = 0;
1da177e4	134
14a6650f DJ	135	if (cpufreq_frequency_table_target(policy, &clock_ratio[0],
14a6650f DJ	136	target_freq, relation, &newstate))
1da177e4 LT	137	return -EINVAL;
1da177e4 LT	138
b43a7ffb	139	powernow_k6_set_state(policy, newstate);
1da177e4 LT	140
	141	return 0;
	142	}
	143
	144
	145	static int powernow_k6_cpu_init(struct cpufreq_policy *policy)
	146	{
14a6650f	147	unsigned int i, f;
1da177e4 LT	148
	149	if (policy->cpu != 0)
	150	return -ENODEV;
	151
	152	/* get frequencies */
	153	max_multiplier = powernow_k6_get_cpu_multiplier();
	154	busfreq = cpu_khz / max_multiplier;
	155
	156	/* table init */
8d2d2051	157	for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
50701588	158	f = clock_ratio[i].driver_data;
14a6650f	159	if (f > max_multiplier)
1da177e4 LT	160	clock_ratio[i].frequency = CPUFREQ_ENTRY_INVALID;
1da177e4 LT	161	else
14a6650f	162	clock_ratio[i].frequency = busfreq * f;
1da177e4 LT	163	}
	164
	165	/* cpuinfo and default policy values */
db2820dd	166	policy->cpuinfo.transition_latency = 200000;
1da177e4 LT	167	policy->cur = busfreq * max_multiplier;
1da177e4 LT	168
b147405a	169	return cpufreq_table_validate_and_show(policy, clock_ratio);
1da177e4 LT	170	}
	171
	172
	173	static int powernow_k6_cpu_exit(struct cpufreq_policy *policy)
	174	{
	175	unsigned int i;
8d2d2051 PC	176	for (i = 0; i < 8; i++) {
8d2d2051 PC	177	if (i == max_multiplier)
b43a7ffb	178	powernow_k6_set_state(policy, i);
1da177e4 LT	179	}
1da177e4 LT	180	cpufreq_frequency_table_put_attr(policy->cpu);
32ee8c3e	181	return 0;
1da177e4 LT	182	}
	183
	184	static unsigned int powernow_k6_get(unsigned int cpu)
	185	{
14a6650f DJ	186	unsigned int ret;
	187	ret = (busfreq * powernow_k6_get_cpu_multiplier());
	188	return ret;
1da177e4 LT	189	}
1da177e4 LT	190
8d2d2051	191	static struct freq_attr *powernow_k6_attr[] = {
1da177e4 LT	192	&cpufreq_freq_attr_scaling_available_freqs,
	193	NULL,
	194	};
	195
221dee28	196	static struct cpufreq_driver powernow_k6_driver = {
32ee8c3e DJ	197	.verify = powernow_k6_verify,
32ee8c3e DJ	198	.target = powernow_k6_target,
1da177e4 LT	199	.init = powernow_k6_cpu_init,
	200	.exit = powernow_k6_cpu_exit,
	201	.get = powernow_k6_get,
	202	.name = "powernow-k6",
1da177e4 LT	203	.attr = powernow_k6_attr,
	204	};
	205
fa8031ae AK	206	static const struct x86_cpu_id powernow_k6_ids[] = {
	207	{ X86_VENDOR_AMD, 5, 12 },
	208	{ X86_VENDOR_AMD, 5, 13 },
	209	{}
	210	};
b4d2d231	211	MODULE_DEVICE_TABLE(x86cpu, powernow_k6_ids);
1da177e4 LT	212
	213	/**
	214	* powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver
	215	*
	216	* Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported
	217	* devices, -EINVAL or -ENOMEM on problems during initiatization, and zero
	218	* on success.
	219	*/
	220	static int __init powernow_k6_init(void)
32ee8c3e	221	{
fa8031ae	222	if (!x86_match_cpu(powernow_k6_ids))
1da177e4 LT	223	return -ENODEV;
	224
	225	if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) {
14a6650f	226	printk(KERN_INFO PFX "PowerNow IOPORT region already used.\n");
1da177e4 LT	227	return -EIO;
	228	}
	229
	230	if (cpufreq_register_driver(&powernow_k6_driver)) {
8d2d2051	231	release_region(POWERNOW_IOPORT, 16);
1da177e4 LT	232	return -EINVAL;
	233	}
	234
	235	return 0;
	236	}
	237
	238
	239	/**
	240	* powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support
	241	*
	242	* Unregisters AMD K6-2+ / K6-3+ PowerNow! support.
	243	*/
	244	static void __exit powernow_k6_exit(void)
	245	{
	246	cpufreq_unregister_driver(&powernow_k6_driver);
8d2d2051	247	release_region(POWERNOW_IOPORT, 16);
1da177e4 LT	248	}
	249
	250
14a6650f DJ	251	MODULE_AUTHOR("Arjan van de Ven, Dave Jones <davej@redhat.com>, "
14a6650f DJ	252	"Dominik Brodowski <linux@brodo.de>");
8d2d2051 PC	253	MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors.");
8d2d2051 PC	254	MODULE_LICENSE("GPL");
1da177e4 LT	255
	256	module_init(powernow_k6_init);
	257	module_exit(powernow_k6_exit);