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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Dave Jones32ee8c32006-02-28 00:43:23 -050016#include <linux/module.h>
17#include <linux/moduleparam.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/init.h>
19#include <linux/cpufreq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/delay.h>
Dave Jonesbbfebd62009-01-17 23:55:22 -050021#include <linux/io.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <asm/ist.h>
Andi Kleenfa8031a2012-01-26 00:09:12 +010023#include <asm/cpu_device_id.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
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.
Dave Jones32ee8c32006-02-28 00:43:23 -050031 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 */
Dave Jonesbbfebd62009-01-17 23:55:22 -050033static int smi_port;
34static int smi_cmd;
35static unsigned int smi_sig;
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
37/* info about the processor */
Rusty Russell1cce76c2009-11-17 14:39:53 -080038static enum speedstep_processor speedstep_processor;
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
Dave Jones32ee8c32006-02-28 00:43:23 -050040/*
41 * There are only two frequency states for each processor. Values
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 * are in kHz for the time being.
43 */
44static struct cpufreq_frequency_table speedstep_freqs[] = {
Dave Jones32ee8c32006-02-28 00:43:23 -050045 {SPEEDSTEP_HIGH, 0},
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 {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
Linus Torvalds1da177e2005-04-16 15:20:36 -070059/**
60 * speedstep_smi_ownership
61 */
Dave Jonesbbfebd62009-01-17 23:55:22 -050062static int speedstep_smi_ownership(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070063{
Stephan Diestelhorstc6e82562008-03-10 16:05:41 +010064 u32 command, result, magic, dummy;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 u32 function = GET_SPEEDSTEP_OWNER;
66 unsigned char magic_data[] = "Copyright (c) 1999 Intel Corporation";
67
68 command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
69 magic = virt_to_phys(magic_data);
70
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +020071 pr_debug("trying to obtain ownership with command %x at port %x\n",
Dave Jonesbbfebd62009-01-17 23:55:22 -050072 command, smi_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
74 __asm__ __volatile__(
Stephan Diestelhorstc6e82562008-03-10 16:05:41 +010075 "push %%ebp\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 "out %%al, (%%dx)\n"
Stephan Diestelhorstc6e82562008-03-10 16:05:41 +010077 "pop %%ebp\n"
Dave Jonesbbfebd62009-01-17 23:55:22 -050078 : "=D" (result),
79 "=a" (dummy), "=b" (dummy), "=c" (dummy), "=d" (dummy),
80 "=S" (dummy)
Andrew Mortonf081a522006-03-25 01:51:51 -080081 : "a" (command), "b" (function), "c" (0), "d" (smi_port),
Dave Jonesbbfebd62009-01-17 23:55:22 -050082 "D" (0), "S" (magic)
Andrew Mortonf081a522006-03-25 01:51:51 -080083 : "memory"
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 );
85
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +020086 pr_debug("result is %x\n", result);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88 return result;
89}
90
91/**
92 * speedstep_smi_get_freqs - get SpeedStep preferred & current freq.
93 * @low: the low frequency value is placed here
94 * @high: the high frequency value is placed here
95 *
96 * Only available on later SpeedStep-enabled systems, returns false results or
97 * even hangs [cf. bugme.osdl.org # 1422] on earlier systems. Empirical testing
98 * shows that the latter occurs if !(ist_info.event & 0xFFFF).
99 */
Dave Jonesbbfebd62009-01-17 23:55:22 -0500100static int speedstep_smi_get_freqs(unsigned int *low, unsigned int *high)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101{
Stephan Diestelhorstc6e82562008-03-10 16:05:41 +0100102 u32 command, result = 0, edi, high_mhz, low_mhz, dummy;
Dave Jonesbbfebd62009-01-17 23:55:22 -0500103 u32 state = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 u32 function = GET_SPEEDSTEP_FREQS;
105
106 if (!(ist_info.event & 0xFFFF)) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200107 pr_debug("bug #1422 -- can't read freqs from BIOS\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 return -ENODEV;
109 }
110
111 command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
112
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200113 pr_debug("trying to determine frequencies with command %x at port %x\n",
Dave Jonesbbfebd62009-01-17 23:55:22 -0500114 command, smi_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115
Stephan Diestelhorstc6e82562008-03-10 16:05:41 +0100116 __asm__ __volatile__(
117 "push %%ebp\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 "out %%al, (%%dx)\n"
Stephan Diestelhorstc6e82562008-03-10 16:05:41 +0100119 "pop %%ebp"
Dave Jonesbbfebd62009-01-17 23:55:22 -0500120 : "=a" (result),
121 "=b" (high_mhz),
122 "=c" (low_mhz),
123 "=d" (state), "=D" (edi), "=S" (dummy)
124 : "a" (command),
125 "b" (function),
126 "c" (state),
127 "d" (smi_port), "S" (0), "D" (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 );
129
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200130 pr_debug("result %x, low_freq %u, high_freq %u\n",
Dave Jonesbbfebd62009-01-17 23:55:22 -0500131 result, low_mhz, high_mhz);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
133 /* abort if results are obviously incorrect... */
134 if ((high_mhz + low_mhz) < 600)
135 return -EINVAL;
136
137 *high = high_mhz * 1000;
138 *low = low_mhz * 1000;
139
140 return result;
Dave Jones32ee8c32006-02-28 00:43:23 -0500141}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
143/**
144 * speedstep_get_state - set the SpeedStep state
145 * @state: processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
146 *
147 */
Dave Jonesbbfebd62009-01-17 23:55:22 -0500148static int speedstep_get_state(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149{
Dave Jonesbbfebd62009-01-17 23:55:22 -0500150 u32 function = GET_SPEEDSTEP_STATE;
Stephan Diestelhorstc6e82562008-03-10 16:05:41 +0100151 u32 result, state, edi, command, dummy;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
153 command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
154
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200155 pr_debug("trying to determine current setting with command %x "
Dave Jonesbbfebd62009-01-17 23:55:22 -0500156 "at port %x\n", command, smi_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
Stephan Diestelhorstc6e82562008-03-10 16:05:41 +0100158 __asm__ __volatile__(
159 "push %%ebp\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 "out %%al, (%%dx)\n"
Stephan Diestelhorstc6e82562008-03-10 16:05:41 +0100161 "pop %%ebp\n"
Dave Jonesbbfebd62009-01-17 23:55:22 -0500162 : "=a" (result),
163 "=b" (state), "=D" (edi),
164 "=c" (dummy), "=d" (dummy), "=S" (dummy)
165 : "a" (command), "b" (function), "c" (0),
166 "d" (smi_port), "S" (0), "D" (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 );
168
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200169 pr_debug("state is %x, result is %x\n", state, result);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
Dave Jonesbbfebd62009-01-17 23:55:22 -0500171 return state & 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172}
173
174
175/**
176 * speedstep_set_state - set the SpeedStep state
177 * @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
178 *
179 */
Dave Jonesbbfebd62009-01-17 23:55:22 -0500180static void speedstep_set_state(unsigned int state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181{
Stephan Diestelhorstc6e82562008-03-10 16:05:41 +0100182 unsigned int result = 0, command, new_state, dummy;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 unsigned long flags;
Dave Jonesbbfebd62009-01-17 23:55:22 -0500184 unsigned int function = SET_SPEEDSTEP_STATE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 unsigned int retry = 0;
186
187 if (state > 0x1)
188 return;
189
190 /* Disable IRQs */
191 local_irq_save(flags);
192
193 command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
194
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200195 pr_debug("trying to set frequency to state %u "
Dave Jonesbbfebd62009-01-17 23:55:22 -0500196 "with command %x at port %x\n",
197 state, command, smi_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198
199 do {
200 if (retry) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200201 pr_debug("retry %u, previous result %u, waiting...\n",
Dave Jonesbbfebd62009-01-17 23:55:22 -0500202 retry, result);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 mdelay(retry * 50);
204 }
205 retry++;
206 __asm__ __volatile__(
Stephan Diestelhorstc6e82562008-03-10 16:05:41 +0100207 "push %%ebp\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 "out %%al, (%%dx)\n"
Stephan Diestelhorstc6e82562008-03-10 16:05:41 +0100209 "pop %%ebp"
Dave Jonesbbfebd62009-01-17 23:55:22 -0500210 : "=b" (new_state), "=D" (result),
211 "=c" (dummy), "=a" (dummy),
212 "=d" (dummy), "=S" (dummy)
213 : "a" (command), "b" (function), "c" (state),
214 "d" (smi_port), "S" (0), "D" (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 );
216 } while ((new_state != state) && (retry <= SMI_TRIES));
217
218 /* enable IRQs */
219 local_irq_restore(flags);
220
Dave Jonesbbfebd62009-01-17 23:55:22 -0500221 if (new_state == state)
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200222 pr_debug("change to %u MHz succeeded after %u tries "
Dave Jonesbbfebd62009-01-17 23:55:22 -0500223 "with result %u\n",
224 (speedstep_freqs[new_state].frequency / 1000),
225 retry, result);
226 else
227 printk(KERN_ERR "cpufreq: change to state %u "
228 "failed with new_state %u and result %u\n",
229 state, new_state, result);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230
231 return;
232}
233
234
235/**
236 * speedstep_target - set a new CPUFreq policy
237 * @policy: new policy
238 * @target_freq: new freq
Dave Jones32ee8c32006-02-28 00:43:23 -0500239 * @relation:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 *
241 * Sets a new CPUFreq policy/freq.
242 */
Dave Jonesbbfebd62009-01-17 23:55:22 -0500243static int speedstep_target(struct cpufreq_policy *policy,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 unsigned int target_freq, unsigned int relation)
245{
246 unsigned int newstate = 0;
247 struct cpufreq_freqs freqs;
248
Dave Jonesbbfebd62009-01-17 23:55:22 -0500249 if (cpufreq_frequency_table_target(policy, &speedstep_freqs[0],
250 target_freq, relation, &newstate))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 return -EINVAL;
252
253 freqs.old = speedstep_freqs[speedstep_get_state()].frequency;
254 freqs.new = speedstep_freqs[newstate].frequency;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
256 if (freqs.old == freqs.new)
257 return 0;
258
Viresh Kumarb43a7ff2013-03-24 11:56:43 +0530259 cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 speedstep_set_state(newstate);
Viresh Kumarb43a7ff2013-03-24 11:56:43 +0530261 cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
263 return 0;
264}
265
266
267/**
268 * speedstep_verify - verifies a new CPUFreq policy
269 * @policy: new policy
270 *
271 * Limit must be within speedstep_low_freq and speedstep_high_freq, with
272 * at least one border included.
273 */
Dave Jonesbbfebd62009-01-17 23:55:22 -0500274static int speedstep_verify(struct cpufreq_policy *policy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275{
276 return cpufreq_frequency_table_verify(policy, &speedstep_freqs[0]);
277}
278
279
280static int speedstep_cpu_init(struct cpufreq_policy *policy)
281{
282 int result;
Dave Jonesbbfebd62009-01-17 23:55:22 -0500283 unsigned int speed, state;
284 unsigned int *low, *high;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285
286 /* capability check */
287 if (policy->cpu != 0)
288 return -ENODEV;
289
290 result = speedstep_smi_ownership();
291 if (result) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200292 pr_debug("fails in acquiring ownership of a SMI interface.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 return -EINVAL;
294 }
295
296 /* detect low and high frequency */
Dave Jonesbbfebd62009-01-17 23:55:22 -0500297 low = &speedstep_freqs[SPEEDSTEP_LOW].frequency;
298 high = &speedstep_freqs[SPEEDSTEP_HIGH].frequency;
299
300 result = speedstep_smi_get_freqs(low, high);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 if (result) {
Dave Jonesbbfebd62009-01-17 23:55:22 -0500302 /* fall back to speedstep_lib.c dection mechanism:
303 * try both states out */
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200304 pr_debug("could not detect low and high frequencies "
Dave Jonesbbfebd62009-01-17 23:55:22 -0500305 "by SMI call.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 result = speedstep_get_freqs(speedstep_processor,
Dave Jonesbbfebd62009-01-17 23:55:22 -0500307 low, high,
Mattia Dongili1a107602005-12-02 21:59:41 +0100308 NULL,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 &speedstep_set_state);
310
311 if (result) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200312 pr_debug("could not detect two different speeds"
Dave Jonesbbfebd62009-01-17 23:55:22 -0500313 " -- aborting.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 return result;
315 } else
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200316 pr_debug("workaround worked.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 }
318
319 /* get current speed setting */
320 state = speedstep_get_state();
321 speed = speedstep_freqs[state].frequency;
322
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200323 pr_debug("currently at %s speed setting - %i MHz\n",
Dave Jonesbbfebd62009-01-17 23:55:22 -0500324 (speed == speedstep_freqs[SPEEDSTEP_LOW].frequency)
325 ? "low" : "high",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 (speed / 1000));
327
328 /* cpuinfo and default policy values */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
330 policy->cur = speed;
331
332 result = cpufreq_frequency_table_cpuinfo(policy, speedstep_freqs);
333 if (result)
Dave Jonesbbfebd62009-01-17 23:55:22 -0500334 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335
Dave Jones32ee8c32006-02-28 00:43:23 -0500336 cpufreq_frequency_table_get_attr(speedstep_freqs, policy->cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337
338 return 0;
339}
340
341static int speedstep_cpu_exit(struct cpufreq_policy *policy)
342{
343 cpufreq_frequency_table_put_attr(policy->cpu);
344 return 0;
345}
346
347static unsigned int speedstep_get(unsigned int cpu)
348{
349 if (cpu)
350 return -ENODEV;
Dave Jonesbbfebd62009-01-17 23:55:22 -0500351 return speedstep_get_frequency(speedstep_processor);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352}
353
354
355static int speedstep_resume(struct cpufreq_policy *policy)
356{
357 int result = speedstep_smi_ownership();
358
359 if (result)
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200360 pr_debug("fails in re-acquiring ownership of a SMI interface.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361
362 return result;
363}
364
Dave Jonesbbfebd62009-01-17 23:55:22 -0500365static struct freq_attr *speedstep_attr[] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 &cpufreq_freq_attr_scaling_available_freqs,
367 NULL,
368};
369
Linus Torvalds221dee22007-02-26 14:55:48 -0800370static struct cpufreq_driver speedstep_driver = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 .name = "speedstep-smi",
Dave Jones32ee8c32006-02-28 00:43:23 -0500372 .verify = speedstep_verify,
373 .target = speedstep_target,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 .init = speedstep_cpu_init,
375 .exit = speedstep_cpu_exit,
376 .get = speedstep_get,
377 .resume = speedstep_resume,
378 .owner = THIS_MODULE,
379 .attr = speedstep_attr,
380};
381
Andi Kleenfa8031a2012-01-26 00:09:12 +0100382static const struct x86_cpu_id ss_smi_ids[] = {
383 { X86_VENDOR_INTEL, 6, 0xb, },
384 { X86_VENDOR_INTEL, 6, 0x8, },
385 { X86_VENDOR_INTEL, 15, 2 },
386 {}
387};
388#if 0
389/* Not auto loaded currently */
390MODULE_DEVICE_TABLE(x86cpu, ss_smi_ids);
391#endif
392
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393/**
394 * speedstep_init - initializes the SpeedStep CPUFreq driver
395 *
396 * Initializes the SpeedStep support. Returns -ENODEV on unsupported
397 * BIOS, -EINVAL on problems during initiatization, and zero on
398 * success.
399 */
400static int __init speedstep_init(void)
401{
Andi Kleenfa8031a2012-01-26 00:09:12 +0100402 if (!x86_match_cpu(ss_smi_ids))
403 return -ENODEV;
404
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 speedstep_processor = speedstep_detect_processor();
406
407 switch (speedstep_processor) {
Dave Jonesbbfebd62009-01-17 23:55:22 -0500408 case SPEEDSTEP_CPU_PIII_T:
409 case SPEEDSTEP_CPU_PIII_C:
410 case SPEEDSTEP_CPU_PIII_C_EARLY:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 default:
413 speedstep_processor = 0;
414 }
415
416 if (!speedstep_processor) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200417 pr_debug("No supported Intel CPU detected.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 return -ENODEV;
419 }
420
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200421 pr_debug("signature:0x%.8ulx, command:0x%.8ulx, "
422 "event:0x%.8ulx, perf_level:0x%.8ulx.\n",
Dave Jonesbbfebd62009-01-17 23:55:22 -0500423 ist_info.signature, ist_info.command,
424 ist_info.event, ist_info.perf_level);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425
Dave Jones32ee8c32006-02-28 00:43:23 -0500426 /* Error if no IST-SMI BIOS or no PARM
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 sig= 'ISGE' aka 'Intel Speedstep Gate E' */
Dave Jones32ee8c32006-02-28 00:43:23 -0500428 if ((ist_info.signature != 0x47534943) && (
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 (smi_port == 0) || (smi_cmd == 0)))
430 return -ENODEV;
431
432 if (smi_sig == 1)
433 smi_sig = 0x47534943;
434 else
435 smi_sig = ist_info.signature;
436
437 /* setup smi_port from MODLULE_PARM or BIOS */
Dave Jones32ee8c32006-02-28 00:43:23 -0500438 if ((smi_port > 0xff) || (smi_port < 0))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 return -EINVAL;
Dave Jones32ee8c32006-02-28 00:43:23 -0500440 else if (smi_port == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 smi_port = ist_info.command & 0xff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442
Dave Jones32ee8c32006-02-28 00:43:23 -0500443 if ((smi_cmd > 0xff) || (smi_cmd < 0))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 return -EINVAL;
Dave Jones32ee8c32006-02-28 00:43:23 -0500445 else if (smi_cmd == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 smi_cmd = (ist_info.command >> 16) & 0xff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447
448 return cpufreq_register_driver(&speedstep_driver);
449}
450
451
452/**
453 * speedstep_exit - unregisters SpeedStep support
454 *
455 * Unregisters SpeedStep support.
456 */
457static void __exit speedstep_exit(void)
458{
459 cpufreq_unregister_driver(&speedstep_driver);
460}
461
Dave Jonesbbfebd62009-01-17 23:55:22 -0500462module_param(smi_port, int, 0444);
463module_param(smi_cmd, int, 0444);
464module_param(smi_sig, uint, 0444);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465
Dave Jonesbbfebd62009-01-17 23:55:22 -0500466MODULE_PARM_DESC(smi_port, "Override the BIOS-given IST port with this value "
467 "-- Intel's default setting is 0xb2");
468MODULE_PARM_DESC(smi_cmd, "Override the BIOS-given IST command with this value "
469 "-- Intel's default setting is 0x82");
470MODULE_PARM_DESC(smi_sig, "Set to 1 to fake the IST signature when using the "
471 "SMI interface.");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472
Dave Jonesbbfebd62009-01-17 23:55:22 -0500473MODULE_AUTHOR("Hiroshi Miura");
474MODULE_DESCRIPTION("Speedstep driver for IST applet SMI interface.");
475MODULE_LICENSE("GPL");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476
477module_init(speedstep_init);
478module_exit(speedstep_exit);