[mirror_ubuntu-hirsute-kernel.git] / arch / i386 / kernel / cpu / cpufreq / speedstep-smi.c

/*
 * Intel SpeedStep SMI driver.
 *
 * (C) 2003  Hiroshi Miura <miura@da-cha.org>
 *
 *  Licensed under the terms of the GNU GPL License version 2.
 *
 */


/*********************************************************************
 *                        SPEEDSTEP - DEFINITIONS                    *
 *********************************************************************/

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <asm/ist.h>

#include "speedstep-lib.h"

/* speedstep system management interface port/command.
 *
 * These parameters are got from IST-SMI BIOS call.
 * If user gives it, these are used.
 *
 */
static int smi_port = 0;
static int smi_cmd = 0;
static unsigned int smi_sig = 0;

/* info about the processor */
static unsigned int speedstep_processor = 0;

/*
 * There are only two frequency states for each processor. Values
 * are in kHz for the time being.
 */
static struct cpufreq_frequency_table speedstep_freqs[] = {
	{SPEEDSTEP_HIGH,	0},
	{SPEEDSTEP_LOW,		0},
	{0,			CPUFREQ_TABLE_END},
};

#define GET_SPEEDSTEP_OWNER 0
#define GET_SPEEDSTEP_STATE 1
#define SET_SPEEDSTEP_STATE 2
#define GET_SPEEDSTEP_FREQS 4

/* how often shall the SMI call be tried if it failed, e.g. because
 * of DMA activity going on? */
#define SMI_TRIES 5

#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "speedstep-smi", msg)

/**
 * speedstep_smi_ownership
 */
static int speedstep_smi_ownership (void)
{
	u32 command, result, magic;
	u32 function = GET_SPEEDSTEP_OWNER;
	unsigned char magic_data[] = "Copyright (c) 1999 Intel Corporation";

	command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
	magic = virt_to_phys(magic_data);

	dprintk("trying to obtain ownership with command %x at port %x\n", command, smi_port);

	__asm__ __volatile__(
		"out %%al, (%%dx)\n"
		: "=D" (result)
		: "a" (command), "b" (function), "c" (0), "d" (smi_port),
			"D" (0), "S" (magic)
		: "memory"
	);

	dprintk("result is %x\n", result);

	return result;
}

/**
 * speedstep_smi_get_freqs - get SpeedStep preferred & current freq.
 * @low: the low frequency value is placed here
 * @high: the high frequency value is placed here
 *
 * Only available on later SpeedStep-enabled systems, returns false results or
 * even hangs [cf. bugme.osdl.org # 1422] on earlier systems. Empirical testing
 * shows that the latter occurs if !(ist_info.event & 0xFFFF).
 */
static int speedstep_smi_get_freqs (unsigned int *low, unsigned int *high)
{
	u32 command, result = 0, edi, high_mhz, low_mhz;
	u32 state=0;
	u32 function = GET_SPEEDSTEP_FREQS;

	if (!(ist_info.event & 0xFFFF)) {
		dprintk("bug #1422 -- can't read freqs from BIOS\n");
		return -ENODEV;
	}

	command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);

	dprintk("trying to determine frequencies with command %x at port %x\n", command, smi_port);

	__asm__ __volatile__("movl $0, %%edi\n"
		"out %%al, (%%dx)\n"
		: "=a" (result), "=b" (high_mhz), "=c" (low_mhz), "=d" (state), "=D" (edi)
		: "a" (command), "b" (function), "c" (state), "d" (smi_port), "S" (0)
	);

	dprintk("result %x, low_freq %u, high_freq %u\n", result, low_mhz, high_mhz);

	/* abort if results are obviously incorrect... */
	if ((high_mhz + low_mhz) < 600)
		return -EINVAL;

	*high = high_mhz * 1000;
	*low  = low_mhz  * 1000;

	return result;
}

/**
 * speedstep_get_state - set the SpeedStep state
 * @state: processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
 *
 */
static int speedstep_get_state (void)
{
	u32 function=GET_SPEEDSTEP_STATE;
	u32 result, state, edi, command;

	command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);

	dprintk("trying to determine current setting with command %x at port %x\n", command, smi_port);

	__asm__ __volatile__("movl $0, %%edi\n"
		"out %%al, (%%dx)\n"
		: "=a" (result), "=b" (state), "=D" (edi)
		: "a" (command), "b" (function), "c" (0), "d" (smi_port), "S" (0)
	);

	dprintk("state is %x, result is %x\n", state, result);

	return (state & 1);
}


/**
 * speedstep_set_state - set the SpeedStep state
 * @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
 *
 */
static void speedstep_set_state (unsigned int state)
{
	unsigned int result = 0, command, new_state;
	unsigned long flags;
	unsigned int function=SET_SPEEDSTEP_STATE;
	unsigned int retry = 0;

	if (state > 0x1)
		return;

	/* Disable IRQs */
	local_irq_save(flags);

	command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);

	dprintk("trying to set frequency to state %u with command %x at port %x\n", state, command, smi_port);

	do {
		if (retry) {
			dprintk("retry %u, previous result %u, waiting...\n", retry, result);
			mdelay(retry * 50);
		}
		retry++;
		__asm__ __volatile__(
			"movl $0, %%edi\n"
			"out %%al, (%%dx)\n"
			: "=b" (new_state), "=D" (result)
			: "a" (command), "b" (function), "c" (state), "d" (smi_port), "S" (0)
			);
	} while ((new_state != state) && (retry <= SMI_TRIES));

	/* enable IRQs */
	local_irq_restore(flags);

	if (new_state == state) {
		dprintk("change to %u MHz succeeded after %u tries with result %u\n", (speedstep_freqs[new_state].frequency / 1000), retry, result);
	} else {
		printk(KERN_ERR "cpufreq: change failed with new_state %u and result %u\n", new_state, result);
	}

	return;
}


/**
 * speedstep_target - set a new CPUFreq policy
 * @policy: new policy
 * @target_freq: new freq
 * @relation:
 *
 * Sets a new CPUFreq policy/freq.
 */
static int speedstep_target (struct cpufreq_policy *policy,
			unsigned int target_freq, unsigned int relation)
{
	unsigned int newstate = 0;
	struct cpufreq_freqs freqs;

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

	freqs.old = speedstep_freqs[speedstep_get_state()].frequency;
	freqs.new = speedstep_freqs[newstate].frequency;
	freqs.cpu = 0; /* speedstep.c is UP only driver */

	if (freqs.old == freqs.new)
		return 0;

	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	speedstep_set_state(newstate);
	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

	return 0;
}


/**
 * speedstep_verify - verifies a new CPUFreq policy
 * @policy: new policy
 *
 * Limit must be within speedstep_low_freq and speedstep_high_freq, with
 * at least one border included.
 */
static int speedstep_verify (struct cpufreq_policy *policy)
{
	return cpufreq_frequency_table_verify(policy, &speedstep_freqs[0]);
}


static int speedstep_cpu_init(struct cpufreq_policy *policy)
{
	int result;
	unsigned int speed,state;

	/* capability check */
	if (policy->cpu != 0)
		return -ENODEV;

	result = speedstep_smi_ownership();
	if (result) {
		dprintk("fails in aquiring ownership of a SMI interface.\n");
		return -EINVAL;
	}

	/* detect low and high frequency */
	result = speedstep_smi_get_freqs(&speedstep_freqs[SPEEDSTEP_LOW].frequency,
				&speedstep_freqs[SPEEDSTEP_HIGH].frequency);
	if (result) {
		/* fall back to speedstep_lib.c dection mechanism: try both states out */
		dprintk("could not detect low and high frequencies by SMI call.\n");
		result = speedstep_get_freqs(speedstep_processor,
				&speedstep_freqs[SPEEDSTEP_LOW].frequency,
				&speedstep_freqs[SPEEDSTEP_HIGH].frequency,
				NULL,
				&speedstep_set_state);

		if (result) {
			dprintk("could not detect two different speeds -- aborting.\n");
			return result;
		} else
			dprintk("workaround worked.\n");
	}

	/* get current speed setting */
	state = speedstep_get_state();
	speed = speedstep_freqs[state].frequency;

	dprintk("currently at %s speed setting - %i MHz\n",
		(speed == speedstep_freqs[SPEEDSTEP_LOW].frequency) ? "low" : "high",
		(speed / 1000));

	/* cpuinfo and default policy values */
	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
	policy->cur = speed;

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

	cpufreq_frequency_table_get_attr(speedstep_freqs, policy->cpu);

	return 0;
}

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

static unsigned int speedstep_get(unsigned int cpu)
{
	if (cpu)
		return -ENODEV;
	return speedstep_get_processor_frequency(speedstep_processor);
}


static int speedstep_resume(struct cpufreq_policy *policy)
{
	int result = speedstep_smi_ownership();

	if (result)
		dprintk("fails in re-aquiring ownership of a SMI interface.\n");

	return result;
}

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

static const struct cpufreq_driver speedstep_driver = {
	.name		= "speedstep-smi",
	.verify		= speedstep_verify,
	.target		= speedstep_target,
	.init		= speedstep_cpu_init,
	.exit		= speedstep_cpu_exit,
	.get		= speedstep_get,
	.resume		= speedstep_resume,
	.owner		= THIS_MODULE,
	.attr		= speedstep_attr,
};

/**
 * speedstep_init - initializes the SpeedStep CPUFreq driver
 *
 *   Initializes the SpeedStep support. Returns -ENODEV on unsupported
 * BIOS, -EINVAL on problems during initiatization, and zero on
 * success.
 */
static int __init speedstep_init(void)
{
	speedstep_processor = speedstep_detect_processor();

	switch (speedstep_processor) {
	case SPEEDSTEP_PROCESSOR_PIII_T:
	case SPEEDSTEP_PROCESSOR_PIII_C:
	case SPEEDSTEP_PROCESSOR_PIII_C_EARLY:
		break;
	default:
		speedstep_processor = 0;
	}

	if (!speedstep_processor) {
		dprintk ("No supported Intel CPU detected.\n");
		return -ENODEV;
	}

	dprintk("signature:0x%.8lx, command:0x%.8lx, event:0x%.8lx, perf_level:0x%.8lx.\n",
		ist_info.signature, ist_info.command, ist_info.event, ist_info.perf_level);

	/* Error if no IST-SMI BIOS or no PARM
		 sig= 'ISGE' aka 'Intel Speedstep Gate E' */
	if ((ist_info.signature !=  0x47534943) && (
	    (smi_port == 0) || (smi_cmd == 0)))
		return -ENODEV;

	if (smi_sig == 1)
		smi_sig = 0x47534943;
	else
		smi_sig = ist_info.signature;

	/* setup smi_port from MODLULE_PARM or BIOS */
	if ((smi_port > 0xff) || (smi_port < 0))
		return -EINVAL;
	else if (smi_port == 0)
		smi_port = ist_info.command & 0xff;

	if ((smi_cmd > 0xff) || (smi_cmd < 0))
		return -EINVAL;
	else if (smi_cmd == 0)
		smi_cmd = (ist_info.command >> 16) & 0xff;

	return cpufreq_register_driver(&speedstep_driver);
}


/**
 * speedstep_exit - unregisters SpeedStep support
 *
 *   Unregisters SpeedStep support.
 */
static void __exit speedstep_exit(void)
{
	cpufreq_unregister_driver(&speedstep_driver);
}

module_param(smi_port,  int, 0444);
module_param(smi_cmd,   int, 0444);
module_param(smi_sig,  uint, 0444);

MODULE_PARM_DESC(smi_port, "Override the BIOS-given IST port with this value -- Intel's default setting is 0xb2");
MODULE_PARM_DESC(smi_cmd, "Override the BIOS-given IST command with this value -- Intel's default setting is 0x82");
MODULE_PARM_DESC(smi_sig, "Set to 1 to fake the IST signature when using the SMI interface.");

MODULE_AUTHOR ("Hiroshi Miura");
MODULE_DESCRIPTION ("Speedstep driver for IST applet SMI interface.");
MODULE_LICENSE ("GPL");

module_init(speedstep_init);
module_exit(speedstep_exit);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Intel SpeedStep SMI driver.
	3	*
	4	* (C) 2003 Hiroshi Miura <miura@da-cha.org>
	5	*
	6	* Licensed under the terms of the GNU GPL License version 2.
	7	*
	8	*/
	9
	10
	11	/*********************************************************************
	12	* SPEEDSTEP - DEFINITIONS *
	13	*********************************************************************/
	14
	15	#include <linux/kernel.h>
32ee8c3e DJ	16	#include <linux/module.h>
32ee8c3e DJ	17	#include <linux/moduleparam.h>
1da177e4 LT	18	#include <linux/init.h>
	19	#include <linux/cpufreq.h>
	20	#include <linux/pci.h>
	21	#include <linux/slab.h>
	22	#include <linux/delay.h>
	23	#include <asm/ist.h>
	24
	25	#include "speedstep-lib.h"
	26
	27	/* speedstep system management interface port/command.
	28	*
	29	* These parameters are got from IST-SMI BIOS call.
	30	* If user gives it, these are used.
32ee8c3e	31	*
1da177e4	32	*/
32ee8c3e DJ	33	static int smi_port = 0;
	34	static int smi_cmd = 0;
	35	static unsigned int smi_sig = 0;
1da177e4 LT	36
1da177e4 LT	37	/* info about the processor */
32ee8c3e	38	static unsigned int speedstep_processor = 0;
1da177e4	39
32ee8c3e DJ	40	/*
32ee8c3e DJ	41	* There are only two frequency states for each processor. Values
1da177e4 LT	42	* are in kHz for the time being.
	43	*/
	44	static struct cpufreq_frequency_table speedstep_freqs[] = {
32ee8c3e	45	{SPEEDSTEP_HIGH, 0},
1da177e4 LT	46	{SPEEDSTEP_LOW, 0},
	47	{0, CPUFREQ_TABLE_END},
	48	};
	49
	50	#define GET_SPEEDSTEP_OWNER 0
	51	#define GET_SPEEDSTEP_STATE 1
	52	#define SET_SPEEDSTEP_STATE 2
	53	#define GET_SPEEDSTEP_FREQS 4
	54
	55	/* how often shall the SMI call be tried if it failed, e.g. because
	56	* of DMA activity going on? */
	57	#define SMI_TRIES 5
	58
	59	#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "speedstep-smi", msg)
	60
	61	/**
	62	* speedstep_smi_ownership
	63	*/
	64	static int speedstep_smi_ownership (void)
	65	{
	66	u32 command, result, magic;
	67	u32 function = GET_SPEEDSTEP_OWNER;
	68	unsigned char magic_data[] = "Copyright (c) 1999 Intel Corporation";
	69
	70	command = (smi_sig & 0xffffff00) \| (smi_cmd & 0xff);
	71	magic = virt_to_phys(magic_data);
	72
	73	dprintk("trying to obtain ownership with command %x at port %x\n", command, smi_port);
	74
	75	__asm__ __volatile__(
	76	"out %%al, (%%dx)\n"
	77	: "=D" (result)
f081a529 AM	78	: "a" (command), "b" (function), "c" (0), "d" (smi_port),
	79	"D" (0), "S" (magic)
	80	: "memory"
1da177e4 LT	81	);
	82
	83	dprintk("result is %x\n", result);
	84
	85	return result;
	86	}
	87
	88	/**
	89	* speedstep_smi_get_freqs - get SpeedStep preferred & current freq.
	90	* @low: the low frequency value is placed here
	91	* @high: the high frequency value is placed here
	92	*
	93	* Only available on later SpeedStep-enabled systems, returns false results or
	94	* even hangs [cf. bugme.osdl.org # 1422] on earlier systems. Empirical testing
	95	* shows that the latter occurs if !(ist_info.event & 0xFFFF).
	96	*/
	97	static int speedstep_smi_get_freqs (unsigned int low, unsigned int high)
	98	{
	99	u32 command, result = 0, edi, high_mhz, low_mhz;
	100	u32 state=0;
	101	u32 function = GET_SPEEDSTEP_FREQS;
	102
	103	if (!(ist_info.event & 0xFFFF)) {
ce38b51e	104	dprintk("bug #1422 -- can't read freqs from BIOS\n");
1da177e4 LT	105	return -ENODEV;
	106	}
	107
	108	command = (smi_sig & 0xffffff00) \| (smi_cmd & 0xff);
	109
	110	dprintk("trying to determine frequencies with command %x at port %x\n", command, smi_port);
	111
	112	__asm__ __volatile__("movl $0, %%edi\n"
	113	"out %%al, (%%dx)\n"
	114	: "=a" (result), "=b" (high_mhz), "=c" (low_mhz), "=d" (state), "=D" (edi)
	115	: "a" (command), "b" (function), "c" (state), "d" (smi_port), "S" (0)
	116	);
	117
	118	dprintk("result %x, low_freq %u, high_freq %u\n", result, low_mhz, high_mhz);
	119
	120	/* abort if results are obviously incorrect... */
	121	if ((high_mhz + low_mhz) < 600)
	122	return -EINVAL;
	123
	124	high = high_mhz 1000;
	125	low = low_mhz 1000;
	126
	127	return result;
32ee8c3e	128	}
1da177e4 LT	129
	130	/**
	131	* speedstep_get_state - set the SpeedStep state
	132	* @state: processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
	133	*
	134	*/
	135	static int speedstep_get_state (void)
	136	{
	137	u32 function=GET_SPEEDSTEP_STATE;
	138	u32 result, state, edi, command;
	139
	140	command = (smi_sig & 0xffffff00) \| (smi_cmd & 0xff);
	141
	142	dprintk("trying to determine current setting with command %x at port %x\n", command, smi_port);
	143
	144	__asm__ __volatile__("movl $0, %%edi\n"
	145	"out %%al, (%%dx)\n"
	146	: "=a" (result), "=b" (state), "=D" (edi)
	147	: "a" (command), "b" (function), "c" (0), "d" (smi_port), "S" (0)
	148	);
	149
	150	dprintk("state is %x, result is %x\n", state, result);
	151
	152	return (state & 1);
	153	}
	154
	155
	156	/**
	157	* speedstep_set_state - set the SpeedStep state
	158	* @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
	159	*
	160	*/
	161	static void speedstep_set_state (unsigned int state)
	162	{
	163	unsigned int result = 0, command, new_state;
	164	unsigned long flags;
	165	unsigned int function=SET_SPEEDSTEP_STATE;
	166	unsigned int retry = 0;
	167
	168	if (state > 0x1)
	169	return;
	170
	171	/* Disable IRQs */
	172	local_irq_save(flags);
	173
	174	command = (smi_sig & 0xffffff00) \| (smi_cmd & 0xff);
	175
	176	dprintk("trying to set frequency to state %u with command %x at port %x\n", state, command, smi_port);
	177
	178	do {
	179	if (retry) {
	180	dprintk("retry %u, previous result %u, waiting...\n", retry, result);
	181	mdelay(retry * 50);
	182	}
	183	retry++;
	184	__asm__ __volatile__(
	185	"movl $0, %%edi\n"
	186	"out %%al, (%%dx)\n"
	187	: "=b" (new_state), "=D" (result)
	188	: "a" (command), "b" (function), "c" (state), "d" (smi_port), "S" (0)
	189	);
	190	} while ((new_state != state) && (retry <= SMI_TRIES));
	191
	192	/* enable IRQs */
193	local_irq_restore(flags);
194
195	if (new_state == state) {
196	dprintk("change to %u MHz succeeded after %u tries with result %u\n", (speedstep_freqs[new_state].frequency / 1000), retry, result);
197	} else {
198	printk(KERN_ERR "cpufreq: change failed with new_state %u and result %u\n", new_state, result);
199	}
200
201	return;
202	}
203
204
205	/**
206	* speedstep_target - set a new CPUFreq policy
207	* @policy: new policy
208	* @target_freq: new freq
32ee8c3e	209	* @relation:
1da177e4 LT	210	*
	211	* Sets a new CPUFreq policy/freq.
	212	*/
	213	static int speedstep_target (struct cpufreq_policy *policy,
	214	unsigned int target_freq, unsigned int relation)
	215	{
	216	unsigned int newstate = 0;
	217	struct cpufreq_freqs freqs;
	218
	219	if (cpufreq_frequency_table_target(policy, &speedstep_freqs[0], target_freq, relation, &newstate))
	220	return -EINVAL;
	221
	222	freqs.old = speedstep_freqs[speedstep_get_state()].frequency;
	223	freqs.new = speedstep_freqs[newstate].frequency;
	224	freqs.cpu = 0; /* speedstep.c is UP only driver */
	225
	226	if (freqs.old == freqs.new)
	227	return 0;
	228
	229	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	230	speedstep_set_state(newstate);
	231	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	232
	233	return 0;
	234	}
	235
	236
	237	/**
	238	* speedstep_verify - verifies a new CPUFreq policy
	239	* @policy: new policy
	240	*
	241	* Limit must be within speedstep_low_freq and speedstep_high_freq, with
	242	* at least one border included.
	243	*/
	244	static int speedstep_verify (struct cpufreq_policy *policy)
	245	{
	246	return cpufreq_frequency_table_verify(policy, &speedstep_freqs[0]);
	247	}
	248
	249
	250	static int speedstep_cpu_init(struct cpufreq_policy *policy)
	251	{
	252	int result;
	253	unsigned int speed,state;
	254
	255	/* capability check */
	256	if (policy->cpu != 0)
	257	return -ENODEV;
	258
	259	result = speedstep_smi_ownership();
	260	if (result) {
	261	dprintk("fails in aquiring ownership of a SMI interface.\n");
	262	return -EINVAL;
	263	}
	264
	265	/* detect low and high frequency */
	266	result = speedstep_smi_get_freqs(&speedstep_freqs[SPEEDSTEP_LOW].frequency,
	267	&speedstep_freqs[SPEEDSTEP_HIGH].frequency);
	268	if (result) {
	269	/* fall back to speedstep_lib.c dection mechanism: try both states out */
	270	dprintk("could not detect low and high frequencies by SMI call.\n");
	271	result = speedstep_get_freqs(speedstep_processor,
	272	&speedstep_freqs[SPEEDSTEP_LOW].frequency,
	273	&speedstep_freqs[SPEEDSTEP_HIGH].frequency,
1a10760c	274	NULL,
1da177e4 LT	275	&speedstep_set_state);
	276
	277	if (result) {
	278	dprintk("could not detect two different speeds -- aborting.\n");
	279	return result;
	280	} else
	281	dprintk("workaround worked.\n");
	282	}
	283
	284	/* get current speed setting */
	285	state = speedstep_get_state();
	286	speed = speedstep_freqs[state].frequency;
	287
32ee8c3e	288	dprintk("currently at %s speed setting - %i MHz\n",
1da177e4 LT	289	(speed == speedstep_freqs[SPEEDSTEP_LOW].frequency) ? "low" : "high",
	290	(speed / 1000));
	291
	292	/* cpuinfo and default policy values */
	293	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
	294	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
	295	policy->cur = speed;
	296
	297	result = cpufreq_frequency_table_cpuinfo(policy, speedstep_freqs);
	298	if (result)
	299	return (result);
	300
32ee8c3e	301	cpufreq_frequency_table_get_attr(speedstep_freqs, policy->cpu);
1da177e4 LT	302
	303	return 0;
	304	}
	305
	306	static int speedstep_cpu_exit(struct cpufreq_policy *policy)
	307	{
	308	cpufreq_frequency_table_put_attr(policy->cpu);
	309	return 0;
	310	}
	311
	312	static unsigned int speedstep_get(unsigned int cpu)
	313	{
	314	if (cpu)
	315	return -ENODEV;
	316	return speedstep_get_processor_frequency(speedstep_processor);
	317	}
	318
	319
	320	static int speedstep_resume(struct cpufreq_policy *policy)
	321	{
	322	int result = speedstep_smi_ownership();
	323
	324	if (result)
	325	dprintk("fails in re-aquiring ownership of a SMI interface.\n");
	326
	327	return result;
	328	}
	329
	330	static struct freq_attr* speedstep_attr[] = {
	331	&cpufreq_freq_attr_scaling_available_freqs,
	332	NULL,
	333	};
	334
aeeddc14	335	static const struct cpufreq_driver speedstep_driver = {
1da177e4	336	.name = "speedstep-smi",
32ee8c3e DJ	337	.verify = speedstep_verify,
32ee8c3e DJ	338	.target = speedstep_target,
1da177e4 LT	339	.init = speedstep_cpu_init,
	340	.exit = speedstep_cpu_exit,
	341	.get = speedstep_get,
	342	.resume = speedstep_resume,
	343	.owner = THIS_MODULE,
	344	.attr = speedstep_attr,
	345	};
	346
	347	/**
	348	* speedstep_init - initializes the SpeedStep CPUFreq driver
	349	*
	350	* Initializes the SpeedStep support. Returns -ENODEV on unsupported
	351	* BIOS, -EINVAL on problems during initiatization, and zero on
	352	* success.
	353	*/
	354	static int __init speedstep_init(void)
	355	{
	356	speedstep_processor = speedstep_detect_processor();
	357
	358	switch (speedstep_processor) {
	359	case SPEEDSTEP_PROCESSOR_PIII_T:
	360	case SPEEDSTEP_PROCESSOR_PIII_C:
	361	case SPEEDSTEP_PROCESSOR_PIII_C_EARLY:
	362	break;
	363	default:
	364	speedstep_processor = 0;
	365	}
	366
	367	if (!speedstep_processor) {
	368	dprintk ("No supported Intel CPU detected.\n");
	369	return -ENODEV;
	370	}
	371
32ee8c3e	372	dprintk("signature:0x%.8lx, command:0x%.8lx, event:0x%.8lx, perf_level:0x%.8lx.\n",
1da177e4 LT	373	ist_info.signature, ist_info.command, ist_info.event, ist_info.perf_level);
1da177e4 LT	374
32ee8c3e	375	/* Error if no IST-SMI BIOS or no PARM
1da177e4	376	sig= 'ISGE' aka 'Intel Speedstep Gate E' */
32ee8c3e	377	if ((ist_info.signature != 0x47534943) && (
1da177e4 LT	378	(smi_port == 0) \|\| (smi_cmd == 0)))
	379	return -ENODEV;
	380
	381	if (smi_sig == 1)
	382	smi_sig = 0x47534943;
	383	else
	384	smi_sig = ist_info.signature;
	385
	386	/* setup smi_port from MODLULE_PARM or BIOS */
32ee8c3e	387	if ((smi_port > 0xff) \|\| (smi_port < 0))
1da177e4	388	return -EINVAL;
32ee8c3e	389	else if (smi_port == 0)
1da177e4	390	smi_port = ist_info.command & 0xff;
1da177e4	391
32ee8c3e	392	if ((smi_cmd > 0xff) \|\| (smi_cmd < 0))
1da177e4	393	return -EINVAL;
32ee8c3e	394	else if (smi_cmd == 0)
1da177e4	395	smi_cmd = (ist_info.command >> 16) & 0xff;
1da177e4 LT	396
	397	return cpufreq_register_driver(&speedstep_driver);
	398	}
	399
	400
	401	/**
	402	* speedstep_exit - unregisters SpeedStep support
	403	*
	404	* Unregisters SpeedStep support.
	405	*/
	406	static void __exit speedstep_exit(void)
	407	{
	408	cpufreq_unregister_driver(&speedstep_driver);
	409	}
	410
	411	module_param(smi_port, int, 0444);
	412	module_param(smi_cmd, int, 0444);
	413	module_param(smi_sig, uint, 0444);
	414
	415	MODULE_PARM_DESC(smi_port, "Override the BIOS-given IST port with this value -- Intel's default setting is 0xb2");
	416	MODULE_PARM_DESC(smi_cmd, "Override the BIOS-given IST command with this value -- Intel's default setting is 0x82");
	417	MODULE_PARM_DESC(smi_sig, "Set to 1 to fake the IST signature when using the SMI interface.");
	418
	419	MODULE_AUTHOR ("Hiroshi Miura");
	420	MODULE_DESCRIPTION ("Speedstep driver for IST applet SMI interface.");
	421	MODULE_LICENSE ("GPL");
	422
	423	module_init(speedstep_init);
	424	module_exit(speedstep_exit);