[mirror_ubuntu-artful-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)
	);

	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 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;
	case SPEEDSTEP_PROCESSOR_P4M:
		printk(KERN_INFO "speedstep-smi: you're trying to use this cpufreq driver on a Pentium 4-based CPU. Most likely it will not work.\n");
		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>
	16	#include <linux/module.h>
	17	#include <linux/moduleparam.h>
	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.
	31	*
	32	*/
	33	static int smi_port = 0;
	34	static int smi_cmd = 0;
	35	static unsigned int smi_sig = 0;
	36
	37	/* info about the processor */
	38	static unsigned int speedstep_processor = 0;
	39
	40	/*
	41	* There are only two frequency states for each processor. Values
	42	* are in kHz for the time being.
	43	*/
	44	static struct cpufreq_frequency_table speedstep_freqs[] = {
	45	{SPEEDSTEP_HIGH, 0},
	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)
78	: "a" (command), "b" (function), "c" (0), "d" (smi_port), "D" (0), "S" (magic)
79	);
80
81	dprintk("result is %x\n", result);
82
83	return result;
84	}
85
86	/**
87	* speedstep_smi_get_freqs - get SpeedStep preferred & current freq.
88	* @low: the low frequency value is placed here
89	* @high: the high frequency value is placed here
90	*
91	* Only available on later SpeedStep-enabled systems, returns false results or
92	* even hangs [cf. bugme.osdl.org # 1422] on earlier systems. Empirical testing
93	* shows that the latter occurs if !(ist_info.event & 0xFFFF).
94	*/
95	static int speedstep_smi_get_freqs (unsigned int low, unsigned int high)
96	{
97	u32 command, result = 0, edi, high_mhz, low_mhz;
98	u32 state=0;
99	u32 function = GET_SPEEDSTEP_FREQS;
100
101	if (!(ist_info.event & 0xFFFF)) {
ce38b51e	102	dprintk("bug #1422 -- can't read freqs from BIOS\n");
1da177e4 LT	103	return -ENODEV;
	104	}
	105
	106	command = (smi_sig & 0xffffff00) \| (smi_cmd & 0xff);
	107
	108	dprintk("trying to determine frequencies with command %x at port %x\n", command, smi_port);
	109
	110	__asm__ __volatile__("movl $0, %%edi\n"
	111	"out %%al, (%%dx)\n"
	112	: "=a" (result), "=b" (high_mhz), "=c" (low_mhz), "=d" (state), "=D" (edi)
	113	: "a" (command), "b" (function), "c" (state), "d" (smi_port), "S" (0)
	114	);
	115
	116	dprintk("result %x, low_freq %u, high_freq %u\n", result, low_mhz, high_mhz);
	117
	118	/* abort if results are obviously incorrect... */
	119	if ((high_mhz + low_mhz) < 600)
	120	return -EINVAL;
	121
	122	high = high_mhz 1000;
	123	low = low_mhz 1000;
	124
	125	return result;
	126	}
	127
	128	/**
	129	* speedstep_get_state - set the SpeedStep state
	130	* @state: processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
	131	*
	132	*/
	133	static int speedstep_get_state (void)
	134	{
	135	u32 function=GET_SPEEDSTEP_STATE;
	136	u32 result, state, edi, command;
	137
	138	command = (smi_sig & 0xffffff00) \| (smi_cmd & 0xff);
	139
	140	dprintk("trying to determine current setting with command %x at port %x\n", command, smi_port);
	141
	142	__asm__ __volatile__("movl $0, %%edi\n"
	143	"out %%al, (%%dx)\n"
	144	: "=a" (result), "=b" (state), "=D" (edi)
	145	: "a" (command), "b" (function), "c" (0), "d" (smi_port), "S" (0)
	146	);
	147
	148	dprintk("state is %x, result is %x\n", state, result);
	149
	150	return (state & 1);
	151	}
	152
	153
	154	/**
	155	* speedstep_set_state - set the SpeedStep state
	156	* @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
	157	*
	158	*/
	159	static void speedstep_set_state (unsigned int state)
	160	{
	161	unsigned int result = 0, command, new_state;
	162	unsigned long flags;
	163	unsigned int function=SET_SPEEDSTEP_STATE;
	164	unsigned int retry = 0;
	165
	166	if (state > 0x1)
167	return;
168
169	/* Disable IRQs */
170	local_irq_save(flags);
171
172	command = (smi_sig & 0xffffff00) \| (smi_cmd & 0xff);
173
174	dprintk("trying to set frequency to state %u with command %x at port %x\n", state, command, smi_port);
175
176	do {
177	if (retry) {
178	dprintk("retry %u, previous result %u, waiting...\n", retry, result);
179	mdelay(retry * 50);
180	}
181	retry++;
182	__asm__ __volatile__(
183	"movl $0, %%edi\n"
184	"out %%al, (%%dx)\n"
185	: "=b" (new_state), "=D" (result)
186	: "a" (command), "b" (function), "c" (state), "d" (smi_port), "S" (0)
187	);
188	} while ((new_state != state) && (retry <= SMI_TRIES));
189
190	/* enable IRQs */
191	local_irq_restore(flags);
192
193	if (new_state == state) {
194	dprintk("change to %u MHz succeeded after %u tries with result %u\n", (speedstep_freqs[new_state].frequency / 1000), retry, result);
195	} else {
196	printk(KERN_ERR "cpufreq: change failed with new_state %u and result %u\n", new_state, result);
197	}
198
199	return;
200	}
201
202
203	/**
204	* speedstep_target - set a new CPUFreq policy
205	* @policy: new policy
206	* @target_freq: new freq
207	* @relation:
208	*
209	* Sets a new CPUFreq policy/freq.
210	*/
211	static int speedstep_target (struct cpufreq_policy *policy,
212	unsigned int target_freq, unsigned int relation)
213	{
214	unsigned int newstate = 0;
215	struct cpufreq_freqs freqs;
216
217	if (cpufreq_frequency_table_target(policy, &speedstep_freqs[0], target_freq, relation, &newstate))
218	return -EINVAL;
219
220	freqs.old = speedstep_freqs[speedstep_get_state()].frequency;
221	freqs.new = speedstep_freqs[newstate].frequency;
222	freqs.cpu = 0; /* speedstep.c is UP only driver */
223
224	if (freqs.old == freqs.new)
225	return 0;
226
227	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
228	speedstep_set_state(newstate);
229	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
230
231	return 0;
232	}
233
234
235	/**
236	* speedstep_verify - verifies a new CPUFreq policy
237	* @policy: new policy
238	*
239	* Limit must be within speedstep_low_freq and speedstep_high_freq, with
240	* at least one border included.
241	*/
242	static int speedstep_verify (struct cpufreq_policy *policy)
243	{
244	return cpufreq_frequency_table_verify(policy, &speedstep_freqs[0]);
245	}
246
247
248	static int speedstep_cpu_init(struct cpufreq_policy *policy)
249	{
250	int result;
251	unsigned int speed,state;
252
253	/* capability check */
254	if (policy->cpu != 0)
255	return -ENODEV;
256
257	result = speedstep_smi_ownership();
258	if (result) {
259	dprintk("fails in aquiring ownership of a SMI interface.\n");
260	return -EINVAL;
261	}
262
263	/* detect low and high frequency */
264	result = speedstep_smi_get_freqs(&speedstep_freqs[SPEEDSTEP_LOW].frequency,
265	&speedstep_freqs[SPEEDSTEP_HIGH].frequency);
266	if (result) {
267	/* fall back to speedstep_lib.c dection mechanism: try both states out */
268	dprintk("could not detect low and high frequencies by SMI call.\n");
269	result = speedstep_get_freqs(speedstep_processor,
270	&speedstep_freqs[SPEEDSTEP_LOW].frequency,
271	&speedstep_freqs[SPEEDSTEP_HIGH].frequency,
1a10760c	272	NULL,
1da177e4 LT	273	&speedstep_set_state);
	274
	275	if (result) {
	276	dprintk("could not detect two different speeds -- aborting.\n");
	277	return result;
	278	} else
	279	dprintk("workaround worked.\n");
	280	}
	281
	282	/* get current speed setting */
	283	state = speedstep_get_state();
	284	speed = speedstep_freqs[state].frequency;
	285
	286	dprintk("currently at %s speed setting - %i MHz\n",
	287	(speed == speedstep_freqs[SPEEDSTEP_LOW].frequency) ? "low" : "high",
	288	(speed / 1000));
	289
	290	/* cpuinfo and default policy values */
	291	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
	292	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
	293	policy->cur = speed;
	294
	295	result = cpufreq_frequency_table_cpuinfo(policy, speedstep_freqs);
	296	if (result)
	297	return (result);
	298
	299	cpufreq_frequency_table_get_attr(speedstep_freqs, policy->cpu);
	300
	301	return 0;
	302	}
	303
	304	static int speedstep_cpu_exit(struct cpufreq_policy *policy)
	305	{
	306	cpufreq_frequency_table_put_attr(policy->cpu);
	307	return 0;
	308	}
	309
	310	static unsigned int speedstep_get(unsigned int cpu)
	311	{
	312	if (cpu)
	313	return -ENODEV;
	314	return speedstep_get_processor_frequency(speedstep_processor);
	315	}
	316
	317
	318	static int speedstep_resume(struct cpufreq_policy *policy)
	319	{
	320	int result = speedstep_smi_ownership();
	321
	322	if (result)
	323	dprintk("fails in re-aquiring ownership of a SMI interface.\n");
	324
	325	return result;
	326	}
	327
	328	static struct freq_attr* speedstep_attr[] = {
	329	&cpufreq_freq_attr_scaling_available_freqs,
	330	NULL,
	331	};
	332
	333	static struct cpufreq_driver speedstep_driver = {
	334	.name = "speedstep-smi",
	335	.verify = speedstep_verify,
	336	.target = speedstep_target,
337	.init = speedstep_cpu_init,
338	.exit = speedstep_cpu_exit,
339	.get = speedstep_get,
340	.resume = speedstep_resume,
341	.owner = THIS_MODULE,
342	.attr = speedstep_attr,
343	};
344
345	/**
346	* speedstep_init - initializes the SpeedStep CPUFreq driver
347	*
348	* Initializes the SpeedStep support. Returns -ENODEV on unsupported
349	* BIOS, -EINVAL on problems during initiatization, and zero on
350	* success.
351	*/
352	static int __init speedstep_init(void)
353	{
354	speedstep_processor = speedstep_detect_processor();
355
356	switch (speedstep_processor) {
357	case SPEEDSTEP_PROCESSOR_PIII_T:
358	case SPEEDSTEP_PROCESSOR_PIII_C:
359	case SPEEDSTEP_PROCESSOR_PIII_C_EARLY:
360	break;
6f4095af DJ	361	case SPEEDSTEP_PROCESSOR_P4M:
	362	printk(KERN_INFO "speedstep-smi: you're trying to use this cpufreq driver on a Pentium 4-based CPU. Most likely it will not work.\n");
	363	break;
1da177e4 LT	364	default:
	365	speedstep_processor = 0;
	366	}
	367
	368	if (!speedstep_processor) {
	369	dprintk ("No supported Intel CPU detected.\n");
	370	return -ENODEV;
	371	}
	372
	373	dprintk("signature:0x%.8lx, command:0x%.8lx, event:0x%.8lx, perf_level:0x%.8lx.\n",
	374	ist_info.signature, ist_info.command, ist_info.event, ist_info.perf_level);
	375
	376
	377	/* Error if no IST-SMI BIOS or no PARM
	378	sig= 'ISGE' aka 'Intel Speedstep Gate E' */
	379	if ((ist_info.signature != 0x47534943) && (
	380	(smi_port == 0) \|\| (smi_cmd == 0)))
	381	return -ENODEV;
	382
	383	if (smi_sig == 1)
	384	smi_sig = 0x47534943;
	385	else
	386	smi_sig = ist_info.signature;
	387
	388	/* setup smi_port from MODLULE_PARM or BIOS */
	389	if ((smi_port > 0xff) \|\| (smi_port < 0)) {
	390	return -EINVAL;
	391	} else if (smi_port == 0) {
	392	smi_port = ist_info.command & 0xff;
	393	}
	394
	395	if ((smi_cmd > 0xff) \|\| (smi_cmd < 0)) {
	396	return -EINVAL;
	397	} else if (smi_cmd == 0) {
	398	smi_cmd = (ist_info.command >> 16) & 0xff;
	399	}
	400
	401	return cpufreq_register_driver(&speedstep_driver);
	402	}
	403
	404
	405	/**
	406	* speedstep_exit - unregisters SpeedStep support
	407	*
	408	* Unregisters SpeedStep support.
	409	*/
	410	static void __exit speedstep_exit(void)
	411	{
	412	cpufreq_unregister_driver(&speedstep_driver);
	413	}
	414
	415	module_param(smi_port, int, 0444);
	416	module_param(smi_cmd, int, 0444);
	417	module_param(smi_sig, uint, 0444);
	418
	419	MODULE_PARM_DESC(smi_port, "Override the BIOS-given IST port with this value -- Intel's default setting is 0xb2");
	420	MODULE_PARM_DESC(smi_cmd, "Override the BIOS-given IST command with this value -- Intel's default setting is 0x82");
	421	MODULE_PARM_DESC(smi_sig, "Set to 1 to fake the IST signature when using the SMI interface.");
	422
	423	MODULE_AUTHOR ("Hiroshi Miura");
	424	MODULE_DESCRIPTION ("Speedstep driver for IST applet SMI interface.");
	425	MODULE_LICENSE ("GPL");
	426
	427	module_init(speedstep_init);
428	module_exit(speedstep_exit);