[linux-2.6-block.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;

static unsigned int			param_busfreq = 0;
static unsigned int			param_max_multiplier = 0;

module_param_named(max_multiplier, param_max_multiplier, uint, S_IRUGO);
MODULE_PARM_DESC(max_multiplier, "Maximum multiplier (allowed values: 20 30 35 40 45 50 55 60)");

module_param_named(bus_frequency, param_busfreq, uint, S_IRUGO);
MODULE_PARM_DESC(bus_frequency, "Bus frequency in kHz");

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

static const u8 index_to_register[8] = { 6, 3, 1, 0, 2, 7, 5, 4 };
static const u8 register_to_index[8] = { 3, 2, 4, 1, 7, 6, 0, 5 };

static const struct {
	unsigned freq;
	unsigned mult;
} usual_frequency_table[] = {
	{ 350000, 35 },	// 100   * 3.5
	{ 400000, 40 },	// 100   * 4
	{ 450000, 45 }, // 100   * 4.5
	{ 475000, 50 }, //  95   * 5
	{ 500000, 50 }, // 100   * 5
	{ 506250, 45 }, // 112.5 * 4.5
	{ 533500, 55 }, //  97   * 5.5
	{ 550000, 55 }, // 100   * 5.5
	{ 562500, 50 }, // 112.5 * 5
	{ 570000, 60 }, //  95   * 6
	{ 600000, 60 }, // 100   * 6
	{ 618750, 55 }, // 112.5 * 5.5
	{ 660000, 55 }, // 120   * 5.5
	{ 675000, 60 }, // 112.5 * 6
	{ 720000, 60 }, // 120   * 6
};

#define FREQ_RANGE		3000

/**
 * 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)
{
	unsigned long invalue = 0;
	u32 msrval;

	local_irq_disable();

	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 */

	local_irq_enable();

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

static void powernow_k6_set_cpu_multiplier(unsigned int best_i)
{
	unsigned long outvalue, invalue;
	unsigned long msrval;
	unsigned long cr0;

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

	/*
	 * The processor doesn't respond to inquiry cycles while changing the
	 * frequency, so we must disable cache.
	 */
	local_irq_disable();
	cr0 = read_cr0();
	write_cr0(cr0 | X86_CR0_CD);
	wbinvd();

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

	msrval = POWERNOW_IOPORT + 0x1;
	wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
	invalue = inl(POWERNOW_IOPORT + 0x8);
	invalue = invalue & 0x1f;
	outvalue = outvalue | invalue;
	outl(outvalue, (POWERNOW_IOPORT + 0x8));
	msrval = POWERNOW_IOPORT + 0x0;
	wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */

	write_cr0(cr0);
	local_irq_enable();
}

/**
 * powernow_k6_target - set the PowerNow! multiplier
 * @best_i: clock_ratio[best_i] is the target multiplier
 *
 *   Tries to change the PowerNow! multiplier
 */
static int powernow_k6_target(struct cpufreq_policy *policy,
		unsigned int best_i)
{

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

	powernow_k6_set_cpu_multiplier(best_i);

	return 0;
}

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

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

	max_multiplier = 0;
	khz = cpu_khz;
	for (i = 0; i < ARRAY_SIZE(usual_frequency_table); i++) {
		if (khz >= usual_frequency_table[i].freq - FREQ_RANGE &&
		    khz <= usual_frequency_table[i].freq + FREQ_RANGE) {
			khz = usual_frequency_table[i].freq;
			max_multiplier = usual_frequency_table[i].mult;
			break;
		}
	}
	if (param_max_multiplier) {
		cpufreq_for_each_entry(pos, clock_ratio)
			if (pos->driver_data == param_max_multiplier) {
				max_multiplier = param_max_multiplier;
				goto have_max_multiplier;
			}
		printk(KERN_ERR "powernow-k6: invalid max_multiplier parameter, valid parameters 20, 30, 35, 40, 45, 50, 55, 60\n");
		return -EINVAL;
	}

	if (!max_multiplier) {
		printk(KERN_WARNING "powernow-k6: unknown frequency %u, cannot determine current multiplier\n", khz);
		printk(KERN_WARNING "powernow-k6: use module parameters max_multiplier and bus_frequency\n");
		return -EOPNOTSUPP;
	}

have_max_multiplier:
	param_max_multiplier = max_multiplier;

	if (param_busfreq) {
		if (param_busfreq >= 50000 && param_busfreq <= 150000) {
			busfreq = param_busfreq / 10;
			goto have_busfreq;
		}
		printk(KERN_ERR "powernow-k6: invalid bus_frequency parameter, allowed range 50000 - 150000 kHz\n");
		return -EINVAL;
	}

	busfreq = khz / max_multiplier;
have_busfreq:
	param_busfreq = busfreq * 10;

	/* table init */
	cpufreq_for_each_entry(pos, clock_ratio) {
		f = pos->driver_data;
		if (f > max_multiplier)
			pos->frequency = CPUFREQ_ENTRY_INVALID;
		else
			pos->frequency = busfreq * f;
	}

	/* cpuinfo and default policy values */
	policy->cpuinfo.transition_latency = 500000;

	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; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
		if (clock_ratio[i].driver_data == max_multiplier) {
			struct cpufreq_freqs freqs;

			freqs.old = policy->cur;
			freqs.new = clock_ratio[i].frequency;
			freqs.flags = 0;

			cpufreq_freq_transition_begin(policy, &freqs);
			powernow_k6_target(policy, i);
			cpufreq_freq_transition_end(policy, &freqs, 0);
			break;
		}
	}
	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 cpufreq_driver powernow_k6_driver = {
	.verify		= cpufreq_generic_frequency_table_verify,
	.target_index	= powernow_k6_target,
	.init		= powernow_k6_cpu_init,
	.exit		= powernow_k6_cpu_exit,
	.get		= powernow_k6_get,
	.name		= "powernow-k6",
	.attr		= cpufreq_generic_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, "
		"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
d82b922a MP	29	static unsigned int param_busfreq = 0;
	30	static unsigned int param_max_multiplier = 0;
	31
	32	module_param_named(max_multiplier, param_max_multiplier, uint, S_IRUGO);
	33	MODULE_PARM_DESC(max_multiplier, "Maximum multiplier (allowed values: 20 30 35 40 45 50 55 60)");
	34
	35	module_param_named(bus_frequency, param_busfreq, uint, S_IRUGO);
	36	MODULE_PARM_DESC(bus_frequency, "Bus frequency in kHz");
1da177e4 LT	37
	38	/* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */
	39	static struct cpufreq_frequency_table clock_ratio[] = {
7f4b0461 VK	40	{0, 60, /* 110 -> 6.0x */ 0},
	41	{0, 55, /* 011 -> 5.5x */ 0},
	42	{0, 50, /* 001 -> 5.0x */ 0},
	43	{0, 45, /* 000 -> 4.5x */ 0},
	44	{0, 40, /* 010 -> 4.0x */ 0},
	45	{0, 35, /* 111 -> 3.5x */ 0},
	46	{0, 30, /* 101 -> 3.0x */ 0},
	47	{0, 20, /* 100 -> 2.0x */ 0},
	48	{0, 0, CPUFREQ_TABLE_END}
1da177e4 LT	49	};
1da177e4 LT	50
22c73795 MP	51	static const u8 index_to_register[8] = { 6, 3, 1, 0, 2, 7, 5, 4 };
	52	static const u8 register_to_index[8] = { 3, 2, 4, 1, 7, 6, 0, 5 };
	53
d82b922a MP	54	static const struct {
	55	unsigned freq;
	56	unsigned mult;
	57	} usual_frequency_table[] = {
853aa05a	58	{ 350000, 35 }, // 100 * 3.5
d82b922a MP	59	{ 400000, 40 }, // 100 * 4
	60	{ 450000, 45 }, // 100 * 4.5
	61	{ 475000, 50 }, // 95 * 5
	62	{ 500000, 50 }, // 100 * 5
	63	{ 506250, 45 }, // 112.5 * 4.5
	64	{ 533500, 55 }, // 97 * 5.5
	65	{ 550000, 55 }, // 100 * 5.5
	66	{ 562500, 50 }, // 112.5 * 5
	67	{ 570000, 60 }, // 95 * 6
	68	{ 600000, 60 }, // 100 * 6
	69	{ 618750, 55 }, // 112.5 * 5.5
	70	{ 660000, 55 }, // 120 * 5.5
	71	{ 675000, 60 }, // 112.5 * 6
	72	{ 720000, 60 }, // 120 * 6
	73	};
	74
	75	#define FREQ_RANGE 3000
1da177e4 LT	76
	77	/**
	78	* powernow_k6_get_cpu_multiplier - returns the current FSB multiplier
	79	*
e20e1d0a	80	* Returns the current setting of the frequency multiplier. Core clock
1da177e4 LT	81	* speed is frequency of the Front-Side Bus multiplied with this value.
	82	*/
	83	static int powernow_k6_get_cpu_multiplier(void)
	84	{
e20e1d0a	85	unsigned long invalue = 0;
14a6650f	86	u32 msrval;
32ee8c3e	87
e20e1d0a MP	88	local_irq_disable();
e20e1d0a MP	89
1da177e4 LT	90	msrval = POWERNOW_IOPORT + 0x1;
1da177e4 LT	91	wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
8d2d2051	92	invalue = inl(POWERNOW_IOPORT + 0x8);
1da177e4 LT	93	msrval = POWERNOW_IOPORT + 0x0;
	94	wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
	95
e20e1d0a MP	96	local_irq_enable();
e20e1d0a MP	97
22c73795	98	return clock_ratio[register_to_index[(invalue >> 5)&7]].driver_data;
1da177e4 LT	99	}
1da177e4 LT	100
e20e1d0a MP	101	static void powernow_k6_set_cpu_multiplier(unsigned int best_i)
	102	{
	103	unsigned long outvalue, invalue;
	104	unsigned long msrval;
	105	unsigned long cr0;
	106
	107	/* we now need to transform best_i to the BVC format, see AMD#23446 */
	108
	109	/*
	110	* The processor doesn't respond to inquiry cycles while changing the
	111	* frequency, so we must disable cache.
	112	*/
	113	local_irq_disable();
	114	cr0 = read_cr0();
	115	write_cr0(cr0 \| X86_CR0_CD);
	116	wbinvd();
	117
22c73795	118	outvalue = (1<<12) \| (1<<10) \| (1<<9) \| (index_to_register[best_i]<<5);
e20e1d0a MP	119
	120	msrval = POWERNOW_IOPORT + 0x1;
	121	wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
	122	invalue = inl(POWERNOW_IOPORT + 0x8);
	123	invalue = invalue & 0x1f;
	124	outvalue = outvalue \| invalue;
	125	outl(outvalue, (POWERNOW_IOPORT + 0x8));
	126	msrval = POWERNOW_IOPORT + 0x0;
	127	wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
	128
	129	write_cr0(cr0);
	130	local_irq_enable();
	131	}
1da177e4 LT	132
1da177e4 LT	133	/**
9c0ebcf7	134	* powernow_k6_target - set the PowerNow! multiplier
1da177e4 LT	135	* @best_i: clock_ratio[best_i] is the target multiplier
	136	*
	137	* Tries to change the PowerNow! multiplier
	138	*/
9c0ebcf7	139	static int powernow_k6_target(struct cpufreq_policy *policy,
b43a7ffb	140	unsigned int best_i)
1da177e4	141	{
1da177e4	142
50701588	143	if (clock_ratio[best_i].driver_data > max_multiplier) {
14a6650f	144	printk(KERN_ERR PFX "invalid target frequency\n");
9c0ebcf7	145	return -EINVAL;
1da177e4 LT	146	}
1da177e4 LT	147
e20e1d0a	148	powernow_k6_set_cpu_multiplier(best_i);
1da177e4	149
1da177e4 LT	150	return 0;
	151	}
	152
1da177e4 LT	153	static int powernow_k6_cpu_init(struct cpufreq_policy *policy)
1da177e4 LT	154	{
041526f9	155	struct cpufreq_frequency_table *pos;
14a6650f	156	unsigned int i, f;
d82b922a	157	unsigned khz;
1da177e4 LT	158
	159	if (policy->cpu != 0)
	160	return -ENODEV;
	161
d82b922a MP	162	max_multiplier = 0;
	163	khz = cpu_khz;
	164	for (i = 0; i < ARRAY_SIZE(usual_frequency_table); i++) {
	165	if (khz >= usual_frequency_table[i].freq - FREQ_RANGE &&
	166	khz <= usual_frequency_table[i].freq + FREQ_RANGE) {
	167	khz = usual_frequency_table[i].freq;
	168	max_multiplier = usual_frequency_table[i].mult;
	169	break;
	170	}
	171	}
	172	if (param_max_multiplier) {
041526f9 SK	173	cpufreq_for_each_entry(pos, clock_ratio)
041526f9 SK	174	if (pos->driver_data == param_max_multiplier) {
d82b922a MP	175	max_multiplier = param_max_multiplier;
	176	goto have_max_multiplier;
	177	}
d82b922a MP	178	printk(KERN_ERR "powernow-k6: invalid max_multiplier parameter, valid parameters 20, 30, 35, 40, 45, 50, 55, 60\n");
	179	return -EINVAL;
	180	}
	181
	182	if (!max_multiplier) {
	183	printk(KERN_WARNING "powernow-k6: unknown frequency %u, cannot determine current multiplier\n", khz);
	184	printk(KERN_WARNING "powernow-k6: use module parameters max_multiplier and bus_frequency\n");
	185	return -EOPNOTSUPP;
	186	}
	187
	188	have_max_multiplier:
	189	param_max_multiplier = max_multiplier;
	190
	191	if (param_busfreq) {
	192	if (param_busfreq >= 50000 && param_busfreq <= 150000) {
	193	busfreq = param_busfreq / 10;
	194	goto have_busfreq;
	195	}
	196	printk(KERN_ERR "powernow-k6: invalid bus_frequency parameter, allowed range 50000 - 150000 kHz\n");
	197	return -EINVAL;
	198	}
	199
	200	busfreq = khz / max_multiplier;
	201	have_busfreq:
	202	param_busfreq = busfreq * 10;
1da177e4 LT	203
1da177e4 LT	204	/* table init */
041526f9 SK	205	cpufreq_for_each_entry(pos, clock_ratio) {
041526f9 SK	206	f = pos->driver_data;
14a6650f	207	if (f > max_multiplier)
041526f9	208	pos->frequency = CPUFREQ_ENTRY_INVALID;
1da177e4	209	else
041526f9	210	pos->frequency = busfreq * f;
1da177e4 LT	211	}
	212
	213	/* cpuinfo and default policy values */
e20e1d0a	214	policy->cpuinfo.transition_latency = 500000;
1da177e4	215
b147405a	216	return cpufreq_table_validate_and_show(policy, clock_ratio);
1da177e4 LT	217	}
	218
	219
	220	static int powernow_k6_cpu_exit(struct cpufreq_policy *policy)
	221	{
	222	unsigned int i;
237ede16 SB	223
237ede16 SB	224	for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
3221e55b SB	225	if (clock_ratio[i].driver_data == max_multiplier) {
	226	struct cpufreq_freqs freqs;
	227
	228	freqs.old = policy->cur;
	229	freqs.new = clock_ratio[i].frequency;
	230	freqs.flags = 0;
	231
	232	cpufreq_freq_transition_begin(policy, &freqs);
9c0ebcf7	233	powernow_k6_target(policy, i);
3221e55b SB	234	cpufreq_freq_transition_end(policy, &freqs, 0);
	235	break;
	236	}
1da177e4	237	}
32ee8c3e	238	return 0;
1da177e4 LT	239	}
	240
	241	static unsigned int powernow_k6_get(unsigned int cpu)
	242	{
14a6650f DJ	243	unsigned int ret;
	244	ret = (busfreq * powernow_k6_get_cpu_multiplier());
	245	return ret;
1da177e4 LT	246	}
1da177e4 LT	247
221dee28	248	static struct cpufreq_driver powernow_k6_driver = {
d63bd27f	249	.verify = cpufreq_generic_frequency_table_verify,
9c0ebcf7	250	.target_index = powernow_k6_target,
1da177e4 LT	251	.init = powernow_k6_cpu_init,
	252	.exit = powernow_k6_cpu_exit,
	253	.get = powernow_k6_get,
	254	.name = "powernow-k6",
d63bd27f	255	.attr = cpufreq_generic_attr,
1da177e4 LT	256	};
1da177e4 LT	257
fa8031ae AK	258	static const struct x86_cpu_id powernow_k6_ids[] = {
	259	{ X86_VENDOR_AMD, 5, 12 },
	260	{ X86_VENDOR_AMD, 5, 13 },
	261	{}
	262	};
b4d2d231	263	MODULE_DEVICE_TABLE(x86cpu, powernow_k6_ids);
1da177e4 LT	264
	265	/**
	266	* powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver
	267	*
	268	* Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported
	269	* devices, -EINVAL or -ENOMEM on problems during initiatization, and zero
	270	* on success.
	271	*/
	272	static int __init powernow_k6_init(void)
32ee8c3e	273	{
fa8031ae	274	if (!x86_match_cpu(powernow_k6_ids))
1da177e4 LT	275	return -ENODEV;
	276
	277	if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) {
14a6650f	278	printk(KERN_INFO PFX "PowerNow IOPORT region already used.\n");
1da177e4 LT	279	return -EIO;
	280	}
	281
	282	if (cpufreq_register_driver(&powernow_k6_driver)) {
8d2d2051	283	release_region(POWERNOW_IOPORT, 16);
1da177e4 LT	284	return -EINVAL;
	285	}
	286
	287	return 0;
	288	}
	289
	290
	291	/**
	292	* powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support
	293	*
	294	* Unregisters AMD K6-2+ / K6-3+ PowerNow! support.
	295	*/
	296	static void __exit powernow_k6_exit(void)
	297	{
	298	cpufreq_unregister_driver(&powernow_k6_driver);
8d2d2051	299	release_region(POWERNOW_IOPORT, 16);
1da177e4 LT	300	}
	301
	302
d5e80b4b	303	MODULE_AUTHOR("Arjan van de Ven, Dave Jones, "
14a6650f	304	"Dominik Brodowski <linux@brodo.de>");
8d2d2051 PC	305	MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors.");
8d2d2051 PC	306	MODULE_LICENSE("GPL");
1da177e4 LT	307
	308	module_init(powernow_k6_init);
	309	module_exit(powernow_k6_exit);