?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
MIPS: ralink: adds include files
[linux-2.6/btrfs-unstable.git] / drivers / cpufreq / powernow-k7.c
blob334cc2f1e9f1fe1a675b7d9eadf9819fbedadfce
1 /*
2 * AMD K7 Powernow driver.
3 * (C) 2003 Dave Jones on behalf of SuSE Labs.
4 * (C) 2003-2004 Dave Jones <davej@redhat.com>
5 *
6 * Licensed under the terms of the GNU GPL License version 2.
7 * Based upon datasheets & sample CPUs kindly provided by AMD.
8 *
9 * Errata 5:
10 * CPU may fail to execute a FID/VID change in presence of interrupt.
11 * - We cli/sti on stepping A0 CPUs around the FID/VID transition.
12 * Errata 15:
13 * CPU with half frequency multipliers may hang upon wakeup from disconnect.
14 * - We disable half multipliers if ACPI is used on A0 stepping CPUs.
15 */
16
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/init.h>
21 #include <linux/cpufreq.h>
22 #include <linux/slab.h>
23 #include <linux/string.h>
24 #include <linux/dmi.h>
25 #include <linux/timex.h>
26 #include <linux/io.h>
27
28 #include <asm/timer.h> /* Needed for recalibrate_cpu_khz() */
29 #include <asm/msr.h>
30 #include <asm/cpu_device_id.h>
31
32 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
33 #include <linux/acpi.h>
34 #include <acpi/processor.h>
35 #endif
36
37 #include "powernow-k7.h"
38
39 #define PFX "powernow: "
40
41
42 struct psb_s {
43 u8 signature[10];
44 u8 tableversion;
45 u8 flags;
46 u16 settlingtime;
47 u8 reserved1;
48 u8 numpst;
49 };
50
51 struct pst_s {
52 u32 cpuid;
53 u8 fsbspeed;
54 u8 maxfid;
55 u8 startvid;
56 u8 numpstates;
57 };
58
59 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
60 union powernow_acpi_control_t {
61 struct {
62 unsigned long fid:5,
63 vid:5,
64 sgtc:20,
65 res1:2;
66 } bits;
67 unsigned long val;
68 };
69 #endif
70
71 /* divide by 1000 to get VCore voltage in V. */
72 static const int mobile_vid_table[32] = {
73 2000, 1950, 1900, 1850, 1800, 1750, 1700, 1650,
74 1600, 1550, 1500, 1450, 1400, 1350, 1300, 0,
75 1275, 1250, 1225, 1200, 1175, 1150, 1125, 1100,
76 1075, 1050, 1025, 1000, 975, 950, 925, 0,
77 };
78
79 /* divide by 10 to get FID. */
80 static const int fid_codes[32] = {
81 110, 115, 120, 125, 50, 55, 60, 65,
82 70, 75, 80, 85, 90, 95, 100, 105,
83 30, 190, 40, 200, 130, 135, 140, 210,
84 150, 225, 160, 165, 170, 180, -1, -1,
85 };
86
87 /* This parameter is used in order to force ACPI instead of legacy method for
88 * configuration purpose.
89 */
90
91 static int acpi_force;
92
93 static struct cpufreq_frequency_table *powernow_table;
94
95 static unsigned int can_scale_bus;
96 static unsigned int can_scale_vid;
97 static unsigned int minimum_speed = -1;
98 static unsigned int maximum_speed;
99 static unsigned int number_scales;
100 static unsigned int fsb;
101 static unsigned int latency;
102 static char have_a0;
103
104 static int check_fsb(unsigned int fsbspeed)
105 {
106 int delta;
107 unsigned int f = fsb / 1000;
108
109 delta = (fsbspeed > f) ? fsbspeed - f : f - fsbspeed;
110 return delta < 5;
111 }
112
113 static const struct x86_cpu_id powernow_k7_cpuids[] = {
114 { X86_VENDOR_AMD, 6, },
115 {}
116 };
117 MODULE_DEVICE_TABLE(x86cpu, powernow_k7_cpuids);
118
119 static int check_powernow(void)
120 {
121 struct cpuinfo_x86 *c = &cpu_data(0);
122 unsigned int maxei, eax, ebx, ecx, edx;
123
124 if (!x86_match_cpu(powernow_k7_cpuids))
125 return 0;
126
127 /* Get maximum capabilities */
128 maxei = cpuid_eax(0x80000000);
129 if (maxei < 0x80000007) { /* Any powernow info ? */
130 #ifdef MODULE
131 printk(KERN_INFO PFX "No powernow capabilities detected\n");
132 #endif
133 return 0;
134 }
135
136 if ((c->x86_model == 6) && (c->x86_mask == 0)) {
137 printk(KERN_INFO PFX "K7 660[A0] core detected, "
138 "enabling errata workarounds\n");
139 have_a0 = 1;
140 }
141
142 cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
143
144 /* Check we can actually do something before we say anything.*/
145 if (!(edx & (1 << 1 | 1 << 2)))
146 return 0;
147
148 printk(KERN_INFO PFX "PowerNOW! Technology present. Can scale: ");
149
150 if (edx & 1 << 1) {
151 printk("frequency");
152 can_scale_bus = 1;
153 }
154
155 if ((edx & (1 << 1 | 1 << 2)) == 0x6)
156 printk(" and ");
157
158 if (edx & 1 << 2) {
159 printk("voltage");
160 can_scale_vid = 1;
161 }
162
163 printk(".\n");
164 return 1;
165 }
166
167 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
168 static void invalidate_entry(unsigned int entry)
169 {
170 powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
171 }
172 #endif
173
174 static int get_ranges(unsigned char *pst)
175 {
176 unsigned int j;
177 unsigned int speed;
178 u8 fid, vid;
179
180 powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) *
181 (number_scales + 1)), GFP_KERNEL);
182 if (!powernow_table)
183 return -ENOMEM;
184
185 for (j = 0 ; j < number_scales; j++) {
186 fid = *pst++;
187
188 powernow_table[j].frequency = (fsb * fid_codes[fid]) / 10;
189 powernow_table[j].index = fid; /* lower 8 bits */
190
191 speed = powernow_table[j].frequency;
192
193 if ((fid_codes[fid] % 10) == 5) {
194 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
195 if (have_a0 == 1)
196 invalidate_entry(j);
197 #endif
198 }
199
200 if (speed < minimum_speed)
201 minimum_speed = speed;
202 if (speed > maximum_speed)
203 maximum_speed = speed;
204
205 vid = *pst++;
206 powernow_table[j].index |= (vid << 8); /* upper 8 bits */
207
208 pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) "
209 "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
210 fid_codes[fid] % 10, speed/1000, vid,
211 mobile_vid_table[vid]/1000,
212 mobile_vid_table[vid]%1000);
213 }
214 powernow_table[number_scales].frequency = CPUFREQ_TABLE_END;
215 powernow_table[number_scales].index = 0;
216
217 return 0;
218 }
219
220
221 static void change_FID(int fid)
222 {
223 union msr_fidvidctl fidvidctl;
224
225 rdmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
226 if (fidvidctl.bits.FID != fid) {
227 fidvidctl.bits.SGTC = latency;
228 fidvidctl.bits.FID = fid;
229 fidvidctl.bits.VIDC = 0;
230 fidvidctl.bits.FIDC = 1;
231 wrmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
232 }
233 }
234
235
236 static void change_VID(int vid)
237 {
238 union msr_fidvidctl fidvidctl;
239
240 rdmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
241 if (fidvidctl.bits.VID != vid) {
242 fidvidctl.bits.SGTC = latency;
243 fidvidctl.bits.VID = vid;
244 fidvidctl.bits.FIDC = 0;
245 fidvidctl.bits.VIDC = 1;
246 wrmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
247 }
248 }
249
250
251 static void change_speed(unsigned int index)
252 {
253 u8 fid, vid;
254 struct cpufreq_freqs freqs;
255 union msr_fidvidstatus fidvidstatus;
256 int cfid;
257
258 /* fid are the lower 8 bits of the index we stored into
259 * the cpufreq frequency table in powernow_decode_bios,
260 * vid are the upper 8 bits.
261 */
262
263 fid = powernow_table[index].index & 0xFF;
264 vid = (powernow_table[index].index & 0xFF00) >> 8;
265
266 freqs.cpu = 0;
267
268 rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
269 cfid = fidvidstatus.bits.CFID;
270 freqs.old = fsb * fid_codes[cfid] / 10;
271
272 freqs.new = powernow_table[index].frequency;
273
274 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
275
276 /* Now do the magic poking into the MSRs. */
277
278 if (have_a0 == 1) /* A0 errata 5 */
279 local_irq_disable();
280
281 if (freqs.old > freqs.new) {
282 /* Going down, so change FID first */
283 change_FID(fid);
284 change_VID(vid);
285 } else {
286 /* Going up, so change VID first */
287 change_VID(vid);
288 change_FID(fid);
289 }
290
291
292 if (have_a0 == 1)
293 local_irq_enable();
294
295 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
296 }
297
298
299 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
300
301 static struct acpi_processor_performance *acpi_processor_perf;
302
303 static int powernow_acpi_init(void)
304 {
305 int i;
306 int retval = 0;
307 union powernow_acpi_control_t pc;
308
309 if (acpi_processor_perf != NULL && powernow_table != NULL) {
310 retval = -EINVAL;
311 goto err0;
312 }
313
314 acpi_processor_perf = kzalloc(sizeof(struct acpi_processor_performance),
315 GFP_KERNEL);
316 if (!acpi_processor_perf) {
317 retval = -ENOMEM;
318 goto err0;
319 }
320
321 if (!zalloc_cpumask_var(&acpi_processor_perf->shared_cpu_map,
322 GFP_KERNEL)) {
323 retval = -ENOMEM;
324 goto err05;
325 }
326
327 if (acpi_processor_register_performance(acpi_processor_perf, 0)) {
328 retval = -EIO;
329 goto err1;
330 }
331
332 if (acpi_processor_perf->control_register.space_id !=
333 ACPI_ADR_SPACE_FIXED_HARDWARE) {
334 retval = -ENODEV;
335 goto err2;
336 }
337
338 if (acpi_processor_perf->status_register.space_id !=
339 ACPI_ADR_SPACE_FIXED_HARDWARE) {
340 retval = -ENODEV;
341 goto err2;
342 }
343
344 number_scales = acpi_processor_perf->state_count;
345
346 if (number_scales < 2) {
347 retval = -ENODEV;
348 goto err2;
349 }
350
351 powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) *
352 (number_scales + 1)), GFP_KERNEL);
353 if (!powernow_table) {
354 retval = -ENOMEM;
355 goto err2;
356 }
357
358 pc.val = (unsigned long) acpi_processor_perf->states[0].control;
359 for (i = 0; i < number_scales; i++) {
360 u8 fid, vid;
361 struct acpi_processor_px *state =
362 &acpi_processor_perf->states[i];
363 unsigned int speed, speed_mhz;
364
365 pc.val = (unsigned long) state->control;
366 pr_debug("acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
367 i,
368 (u32) state->core_frequency,
369 (u32) state->power,
370 (u32) state->transition_latency,
371 (u32) state->control,
372 pc.bits.sgtc);
373
374 vid = pc.bits.vid;
375 fid = pc.bits.fid;
376
377 powernow_table[i].frequency = fsb * fid_codes[fid] / 10;
378 powernow_table[i].index = fid; /* lower 8 bits */
379 powernow_table[i].index |= (vid << 8); /* upper 8 bits */
380
381 speed = powernow_table[i].frequency;
382 speed_mhz = speed / 1000;
383
384 /* processor_perflib will multiply the MHz value by 1000 to
385 * get a KHz value (e.g. 1266000). However, powernow-k7 works
386 * with true KHz values (e.g. 1266768). To ensure that all
387 * powernow frequencies are available, we must ensure that
388 * ACPI doesn't restrict them, so we round up the MHz value
389 * to ensure that perflib's computed KHz value is greater than
390 * or equal to powernow's KHz value.
391 */
392 if (speed % 1000 > 0)
393 speed_mhz++;
394
395 if ((fid_codes[fid] % 10) == 5) {
396 if (have_a0 == 1)
397 invalidate_entry(i);
398 }
399
400 pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) "
401 "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
402 fid_codes[fid] % 10, speed_mhz, vid,
403 mobile_vid_table[vid]/1000,
404 mobile_vid_table[vid]%1000);
405
406 if (state->core_frequency != speed_mhz) {
407 state->core_frequency = speed_mhz;
408 pr_debug(" Corrected ACPI frequency to %d\n",
409 speed_mhz);
410 }
411
412 if (latency < pc.bits.sgtc)
413 latency = pc.bits.sgtc;
414
415 if (speed < minimum_speed)
416 minimum_speed = speed;
417 if (speed > maximum_speed)
418 maximum_speed = speed;
419 }
420
421 powernow_table[i].frequency = CPUFREQ_TABLE_END;
422 powernow_table[i].index = 0;
423
424 /* notify BIOS that we exist */
425 acpi_processor_notify_smm(THIS_MODULE);
426
427 return 0;
428
429 err2:
430 acpi_processor_unregister_performance(acpi_processor_perf, 0);
431 err1:
432 free_cpumask_var(acpi_processor_perf->shared_cpu_map);
433 err05:
434 kfree(acpi_processor_perf);
435 err0:
436 printk(KERN_WARNING PFX "ACPI perflib can not be used on "
437 "this platform\n");
438 acpi_processor_perf = NULL;
439 return retval;
440 }
441 #else
442 static int powernow_acpi_init(void)
443 {
444 printk(KERN_INFO PFX "no support for ACPI processor found."
445 " Please recompile your kernel with ACPI processor\n");
446 return -EINVAL;
447 }
448 #endif
449
450 static void print_pst_entry(struct pst_s *pst, unsigned int j)
451 {
452 pr_debug("PST:%d (@%p)\n", j, pst);
453 pr_debug(" cpuid: 0x%x fsb: %d maxFID: 0x%x startvid: 0x%x\n",
454 pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid);
455 }
456
457 static int powernow_decode_bios(int maxfid, int startvid)
458 {
459 struct psb_s *psb;
460 struct pst_s *pst;
461 unsigned int i, j;
462 unsigned char *p;
463 unsigned int etuple;
464 unsigned int ret;
465
466 etuple = cpuid_eax(0x80000001);
467
468 for (i = 0xC0000; i < 0xffff0 ; i += 16) {
469
470 p = phys_to_virt(i);
471
472 if (memcmp(p, "AMDK7PNOW!", 10) == 0) {
473 pr_debug("Found PSB header at %p\n", p);
474 psb = (struct psb_s *) p;
475 pr_debug("Table version: 0x%x\n", psb->tableversion);
476 if (psb->tableversion != 0x12) {
477 printk(KERN_INFO PFX "Sorry, only v1.2 tables"
478 " supported right now\n");
479 return -ENODEV;
480 }
481
482 pr_debug("Flags: 0x%x\n", psb->flags);
483 if ((psb->flags & 1) == 0)
484 pr_debug("Mobile voltage regulator\n");
485 else
486 pr_debug("Desktop voltage regulator\n");
487
488 latency = psb->settlingtime;
489 if (latency < 100) {
490 printk(KERN_INFO PFX "BIOS set settling time "
491 "to %d microseconds. "
492 "Should be at least 100. "
493 "Correcting.\n", latency);
494 latency = 100;
495 }
496 pr_debug("Settling Time: %d microseconds.\n",
497 psb->settlingtime);
498 pr_debug("Has %d PST tables. (Only dumping ones "
499 "relevant to this CPU).\n",
500 psb->numpst);
501
502 p += sizeof(struct psb_s);
503
504 pst = (struct pst_s *) p;
505
506 for (j = 0; j < psb->numpst; j++) {
507 pst = (struct pst_s *) p;
508 number_scales = pst->numpstates;
509
510 if ((etuple == pst->cpuid) &&
511 check_fsb(pst->fsbspeed) &&
512 (maxfid == pst->maxfid) &&
513 (startvid == pst->startvid)) {
514 print_pst_entry(pst, j);
515 p = (char *)pst + sizeof(struct pst_s);
516 ret = get_ranges(p);
517 return ret;
518 } else {
519 unsigned int k;
520 p = (char *)pst + sizeof(struct pst_s);
521 for (k = 0; k < number_scales; k++)
522 p += 2;
523 }
524 }
525 printk(KERN_INFO PFX "No PST tables match this cpuid "
526 "(0x%x)\n", etuple);
527 printk(KERN_INFO PFX "This is indicative of a broken "
528 "BIOS.\n");
529
530 return -EINVAL;
531 }
532 p++;
533 }
534
535 return -ENODEV;
536 }
537
538
539 static int powernow_target(struct cpufreq_policy *policy,
540 unsigned int target_freq,
541 unsigned int relation)
542 {
543 unsigned int newstate;
544
545 if (cpufreq_frequency_table_target(policy, powernow_table, target_freq,
546 relation, &newstate))
547 return -EINVAL;
548
549 change_speed(newstate);
550
551 return 0;
552 }
553
554
555 static int powernow_verify(struct cpufreq_policy *policy)
556 {
557 return cpufreq_frequency_table_verify(policy, powernow_table);
558 }
559
560 /*
561 * We use the fact that the bus frequency is somehow
562 * a multiple of 100000/3 khz, then we compute sgtc according
563 * to this multiple.
564 * That way, we match more how AMD thinks all of that work.
565 * We will then get the same kind of behaviour already tested under
566 * the "well-known" other OS.
567 */
568 static int __cpuinit fixup_sgtc(void)
569 {
570 unsigned int sgtc;
571 unsigned int m;
572
573 m = fsb / 3333;
574 if ((m % 10) >= 5)
575 m += 5;
576
577 m /= 10;
578
579 sgtc = 100 * m * latency;
580 sgtc = sgtc / 3;
581 if (sgtc > 0xfffff) {
582 printk(KERN_WARNING PFX "SGTC too large %d\n", sgtc);
583 sgtc = 0xfffff;
584 }
585 return sgtc;
586 }
587
588 static unsigned int powernow_get(unsigned int cpu)
589 {
590 union msr_fidvidstatus fidvidstatus;
591 unsigned int cfid;
592
593 if (cpu)
594 return 0;
595 rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
596 cfid = fidvidstatus.bits.CFID;
597
598 return fsb * fid_codes[cfid] / 10;
599 }
600
601
602 static int __cpuinit acer_cpufreq_pst(const struct dmi_system_id *d)
603 {
604 printk(KERN_WARNING PFX
605 "%s laptop with broken PST tables in BIOS detected.\n",
606 d->ident);
607 printk(KERN_WARNING PFX
608 "You need to downgrade to 3A21 (09/09/2002), or try a newer "
609 "BIOS than 3A71 (01/20/2003)\n");
610 printk(KERN_WARNING PFX
611 "cpufreq scaling has been disabled as a result of this.\n");
612 return 0;
613 }
614
615 /*
616 * Some Athlon laptops have really fucked PST tables.
617 * A BIOS update is all that can save them.
618 * Mention this, and disable cpufreq.
619 */
620 static struct dmi_system_id __cpuinitdata powernow_dmi_table[] = {
621 {
622 .callback = acer_cpufreq_pst,
623 .ident = "Acer Aspire",
624 .matches = {
625 DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"),
626 DMI_MATCH(DMI_BIOS_VERSION, "3A71"),
627 },
628 },
629 { }
630 };
631
632 static int __cpuinit powernow_cpu_init(struct cpufreq_policy *policy)
633 {
634 union msr_fidvidstatus fidvidstatus;
635 int result;
636
637 if (policy->cpu != 0)
638 return -ENODEV;
639
640 rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
641
642 recalibrate_cpu_khz();
643
644 fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID];
645 if (!fsb) {
646 printk(KERN_WARNING PFX "can not determine bus frequency\n");
647 return -EINVAL;
648 }
649 pr_debug("FSB: %3dMHz\n", fsb/1000);
650
651 if (dmi_check_system(powernow_dmi_table) || acpi_force) {
652 printk(KERN_INFO PFX "PSB/PST known to be broken. "
653 "Trying ACPI instead\n");
654 result = powernow_acpi_init();
655 } else {
656 result = powernow_decode_bios(fidvidstatus.bits.MFID,
657 fidvidstatus.bits.SVID);
658 if (result) {
659 printk(KERN_INFO PFX "Trying ACPI perflib\n");
660 maximum_speed = 0;
661 minimum_speed = -1;
662 latency = 0;
663 result = powernow_acpi_init();
664 if (result) {
665 printk(KERN_INFO PFX
666 "ACPI and legacy methods failed\n");
667 }
668 } else {
669 /* SGTC use the bus clock as timer */
670 latency = fixup_sgtc();
671 printk(KERN_INFO PFX "SGTC: %d\n", latency);
672 }
673 }
674
675 if (result)
676 return result;
677
678 printk(KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n",
679 minimum_speed/1000, maximum_speed/1000);
680
681 policy->cpuinfo.transition_latency =
682 cpufreq_scale(2000000UL, fsb, latency);
683
684 policy->cur = powernow_get(0);
685
686 cpufreq_frequency_table_get_attr(powernow_table, policy->cpu);
687
688 return cpufreq_frequency_table_cpuinfo(policy, powernow_table);
689 }
690
691 static int powernow_cpu_exit(struct cpufreq_policy *policy)
692 {
693 cpufreq_frequency_table_put_attr(policy->cpu);
694
695 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
696 if (acpi_processor_perf) {
697 acpi_processor_unregister_performance(acpi_processor_perf, 0);
698 free_cpumask_var(acpi_processor_perf->shared_cpu_map);
699 kfree(acpi_processor_perf);
700 }
701 #endif
702
703 kfree(powernow_table);
704 return 0;
705 }
706
707 static struct freq_attr *powernow_table_attr[] = {
708 &cpufreq_freq_attr_scaling_available_freqs,
709 NULL,
710 };
711
712 static struct cpufreq_driver powernow_driver = {
713 .verify = powernow_verify,
714 .target = powernow_target,
715 .get = powernow_get,
716 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
717 .bios_limit = acpi_processor_get_bios_limit,
718 #endif
719 .init = powernow_cpu_init,
720 .exit = powernow_cpu_exit,
721 .name = "powernow-k7",
722 .owner = THIS_MODULE,
723 .attr = powernow_table_attr,
724 };
725
726 static int __init powernow_init(void)
727 {
728 if (check_powernow() == 0)
729 return -ENODEV;
730 return cpufreq_register_driver(&powernow_driver);
731 }
732
733
734 static void __exit powernow_exit(void)
735 {
736 cpufreq_unregister_driver(&powernow_driver);
737 }
738
739 module_param(acpi_force, int, 0444);
740 MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");
741
742 MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
743 MODULE_DESCRIPTION("Powernow driver for AMD K7 processors.");
744 MODULE_LICENSE("GPL");
745
746 late_initcall(powernow_init);
747 module_exit(powernow_exit);
748
(deprecated) Btrfs devel tree