Merge branch 'gart/rename' of git://git.kernel.org/pub/scm/linux/kernel/git/joro...
[linux-2.6.git] / drivers / cpufreq / speedstep-ich.c
1 /*
2  * (C) 2001  Dave Jones, Arjan van de ven.
3  * (C) 2002 - 2003  Dominik Brodowski <linux@brodo.de>
4  *
5  *  Licensed under the terms of the GNU GPL License version 2.
6  *  Based upon reverse engineered information, and on Intel documentation
7  *  for chipsets ICH2-M and ICH3-M.
8  *
9  *  Many thanks to Ducrot Bruno for finding and fixing the last
10  *  "missing link" for ICH2-M/ICH3-M support, and to Thomas Winkler
11  *  for extensive testing.
12  *
13  *  BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
14  */
15
16
17 /*********************************************************************
18  *                        SPEEDSTEP - DEFINITIONS                    *
19  *********************************************************************/
20
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/cpufreq.h>
25 #include <linux/pci.h>
26 #include <linux/sched.h>
27
28 #include "speedstep-lib.h"
29
30
31 /* speedstep_chipset:
32  *   It is necessary to know which chipset is used. As accesses to
33  * this device occur at various places in this module, we need a
34  * static struct pci_dev * pointing to that device.
35  */
36 static struct pci_dev *speedstep_chipset_dev;
37
38
39 /* speedstep_processor
40  */
41 static enum speedstep_processor speedstep_processor;
42
43 static u32 pmbase;
44
45 /*
46  *   There are only two frequency states for each processor. Values
47  * are in kHz for the time being.
48  */
49 static struct cpufreq_frequency_table speedstep_freqs[] = {
50         {SPEEDSTEP_HIGH,        0},
51         {SPEEDSTEP_LOW,         0},
52         {0,                     CPUFREQ_TABLE_END},
53 };
54
55
56 /**
57  * speedstep_find_register - read the PMBASE address
58  *
59  * Returns: -ENODEV if no register could be found
60  */
61 static int speedstep_find_register(void)
62 {
63         if (!speedstep_chipset_dev)
64                 return -ENODEV;
65
66         /* get PMBASE */
67         pci_read_config_dword(speedstep_chipset_dev, 0x40, &pmbase);
68         if (!(pmbase & 0x01)) {
69                 printk(KERN_ERR "speedstep-ich: could not find speedstep register\n");
70                 return -ENODEV;
71         }
72
73         pmbase &= 0xFFFFFFFE;
74         if (!pmbase) {
75                 printk(KERN_ERR "speedstep-ich: could not find speedstep register\n");
76                 return -ENODEV;
77         }
78
79         pr_debug("pmbase is 0x%x\n", pmbase);
80         return 0;
81 }
82
83 /**
84  * speedstep_set_state - set the SpeedStep state
85  * @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
86  *
87  *   Tries to change the SpeedStep state.  Can be called from
88  *   smp_call_function_single.
89  */
90 static void speedstep_set_state(unsigned int state)
91 {
92         u8 pm2_blk;
93         u8 value;
94         unsigned long flags;
95
96         if (state > 0x1)
97                 return;
98
99         /* Disable IRQs */
100         local_irq_save(flags);
101
102         /* read state */
103         value = inb(pmbase + 0x50);
104
105         pr_debug("read at pmbase 0x%x + 0x50 returned 0x%x\n", pmbase, value);
106
107         /* write new state */
108         value &= 0xFE;
109         value |= state;
110
111         pr_debug("writing 0x%x to pmbase 0x%x + 0x50\n", value, pmbase);
112
113         /* Disable bus master arbitration */
114         pm2_blk = inb(pmbase + 0x20);
115         pm2_blk |= 0x01;
116         outb(pm2_blk, (pmbase + 0x20));
117
118         /* Actual transition */
119         outb(value, (pmbase + 0x50));
120
121         /* Restore bus master arbitration */
122         pm2_blk &= 0xfe;
123         outb(pm2_blk, (pmbase + 0x20));
124
125         /* check if transition was successful */
126         value = inb(pmbase + 0x50);
127
128         /* Enable IRQs */
129         local_irq_restore(flags);
130
131         pr_debug("read at pmbase 0x%x + 0x50 returned 0x%x\n", pmbase, value);
132
133         if (state == (value & 0x1))
134                 pr_debug("change to %u MHz succeeded\n",
135                         speedstep_get_frequency(speedstep_processor) / 1000);
136         else
137                 printk(KERN_ERR "cpufreq: change failed - I/O error\n");
138
139         return;
140 }
141
142 /* Wrapper for smp_call_function_single. */
143 static void _speedstep_set_state(void *_state)
144 {
145         speedstep_set_state(*(unsigned int *)_state);
146 }
147
148 /**
149  * speedstep_activate - activate SpeedStep control in the chipset
150  *
151  *   Tries to activate the SpeedStep status and control registers.
152  * Returns -EINVAL on an unsupported chipset, and zero on success.
153  */
154 static int speedstep_activate(void)
155 {
156         u16 value = 0;
157
158         if (!speedstep_chipset_dev)
159                 return -EINVAL;
160
161         pci_read_config_word(speedstep_chipset_dev, 0x00A0, &value);
162         if (!(value & 0x08)) {
163                 value |= 0x08;
164                 pr_debug("activating SpeedStep (TM) registers\n");
165                 pci_write_config_word(speedstep_chipset_dev, 0x00A0, value);
166         }
167
168         return 0;
169 }
170
171
172 /**
173  * speedstep_detect_chipset - detect the Southbridge which contains SpeedStep logic
174  *
175  *   Detects ICH2-M, ICH3-M and ICH4-M so far. The pci_dev points to
176  * the LPC bridge / PM module which contains all power-management
177  * functions. Returns the SPEEDSTEP_CHIPSET_-number for the detected
178  * chipset, or zero on failure.
179  */
180 static unsigned int speedstep_detect_chipset(void)
181 {
182         speedstep_chipset_dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
183                               PCI_DEVICE_ID_INTEL_82801DB_12,
184                               PCI_ANY_ID, PCI_ANY_ID,
185                               NULL);
186         if (speedstep_chipset_dev)
187                 return 4; /* 4-M */
188
189         speedstep_chipset_dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
190                               PCI_DEVICE_ID_INTEL_82801CA_12,
191                               PCI_ANY_ID, PCI_ANY_ID,
192                               NULL);
193         if (speedstep_chipset_dev)
194                 return 3; /* 3-M */
195
196
197         speedstep_chipset_dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
198                               PCI_DEVICE_ID_INTEL_82801BA_10,
199                               PCI_ANY_ID, PCI_ANY_ID,
200                               NULL);
201         if (speedstep_chipset_dev) {
202                 /* speedstep.c causes lockups on Dell Inspirons 8000 and
203                  * 8100 which use a pretty old revision of the 82815
204                  * host brige. Abort on these systems.
205                  */
206                 static struct pci_dev *hostbridge;
207
208                 hostbridge  = pci_get_subsys(PCI_VENDOR_ID_INTEL,
209                               PCI_DEVICE_ID_INTEL_82815_MC,
210                               PCI_ANY_ID, PCI_ANY_ID,
211                               NULL);
212
213                 if (!hostbridge)
214                         return 2; /* 2-M */
215
216                 if (hostbridge->revision < 5) {
217                         pr_debug("hostbridge does not support speedstep\n");
218                         speedstep_chipset_dev = NULL;
219                         pci_dev_put(hostbridge);
220                         return 0;
221                 }
222
223                 pci_dev_put(hostbridge);
224                 return 2; /* 2-M */
225         }
226
227         return 0;
228 }
229
230 static void get_freq_data(void *_speed)
231 {
232         unsigned int *speed = _speed;
233
234         *speed = speedstep_get_frequency(speedstep_processor);
235 }
236
237 static unsigned int speedstep_get(unsigned int cpu)
238 {
239         unsigned int speed;
240
241         /* You're supposed to ensure CPU is online. */
242         if (smp_call_function_single(cpu, get_freq_data, &speed, 1) != 0)
243                 BUG();
244
245         pr_debug("detected %u kHz as current frequency\n", speed);
246         return speed;
247 }
248
249 /**
250  * speedstep_target - set a new CPUFreq policy
251  * @policy: new policy
252  * @target_freq: the target frequency
253  * @relation: how that frequency relates to achieved frequency
254  *      (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H)
255  *
256  * Sets a new CPUFreq policy.
257  */
258 static int speedstep_target(struct cpufreq_policy *policy,
259                              unsigned int target_freq,
260                              unsigned int relation)
261 {
262         unsigned int newstate = 0, policy_cpu;
263         struct cpufreq_freqs freqs;
264         int i;
265
266         if (cpufreq_frequency_table_target(policy, &speedstep_freqs[0],
267                                 target_freq, relation, &newstate))
268                 return -EINVAL;
269
270         policy_cpu = cpumask_any_and(policy->cpus, cpu_online_mask);
271         freqs.old = speedstep_get(policy_cpu);
272         freqs.new = speedstep_freqs[newstate].frequency;
273         freqs.cpu = policy->cpu;
274
275         pr_debug("transiting from %u to %u kHz\n", freqs.old, freqs.new);
276
277         /* no transition necessary */
278         if (freqs.old == freqs.new)
279                 return 0;
280
281         for_each_cpu(i, policy->cpus) {
282                 freqs.cpu = i;
283                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
284         }
285
286         smp_call_function_single(policy_cpu, _speedstep_set_state, &newstate,
287                                  true);
288
289         for_each_cpu(i, policy->cpus) {
290                 freqs.cpu = i;
291                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
292         }
293
294         return 0;
295 }
296
297
298 /**
299  * speedstep_verify - verifies a new CPUFreq policy
300  * @policy: new policy
301  *
302  * Limit must be within speedstep_low_freq and speedstep_high_freq, with
303  * at least one border included.
304  */
305 static int speedstep_verify(struct cpufreq_policy *policy)
306 {
307         return cpufreq_frequency_table_verify(policy, &speedstep_freqs[0]);
308 }
309
310 struct get_freqs {
311         struct cpufreq_policy *policy;
312         int ret;
313 };
314
315 static void get_freqs_on_cpu(void *_get_freqs)
316 {
317         struct get_freqs *get_freqs = _get_freqs;
318
319         get_freqs->ret =
320                 speedstep_get_freqs(speedstep_processor,
321                             &speedstep_freqs[SPEEDSTEP_LOW].frequency,
322                             &speedstep_freqs[SPEEDSTEP_HIGH].frequency,
323                             &get_freqs->policy->cpuinfo.transition_latency,
324                             &speedstep_set_state);
325 }
326
327 static int speedstep_cpu_init(struct cpufreq_policy *policy)
328 {
329         int result;
330         unsigned int policy_cpu, speed;
331         struct get_freqs gf;
332
333         /* only run on CPU to be set, or on its sibling */
334 #ifdef CONFIG_SMP
335         cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu));
336 #endif
337         policy_cpu = cpumask_any_and(policy->cpus, cpu_online_mask);
338
339         /* detect low and high frequency and transition latency */
340         gf.policy = policy;
341         smp_call_function_single(policy_cpu, get_freqs_on_cpu, &gf, 1);
342         if (gf.ret)
343                 return gf.ret;
344
345         /* get current speed setting */
346         speed = speedstep_get(policy_cpu);
347         if (!speed)
348                 return -EIO;
349
350         pr_debug("currently at %s speed setting - %i MHz\n",
351                 (speed == speedstep_freqs[SPEEDSTEP_LOW].frequency)
352                 ? "low" : "high",
353                 (speed / 1000));
354
355         /* cpuinfo and default policy values */
356         policy->cur = speed;
357
358         result = cpufreq_frequency_table_cpuinfo(policy, speedstep_freqs);
359         if (result)
360                 return result;
361
362         cpufreq_frequency_table_get_attr(speedstep_freqs, policy->cpu);
363
364         return 0;
365 }
366
367
368 static int speedstep_cpu_exit(struct cpufreq_policy *policy)
369 {
370         cpufreq_frequency_table_put_attr(policy->cpu);
371         return 0;
372 }
373
374 static struct freq_attr *speedstep_attr[] = {
375         &cpufreq_freq_attr_scaling_available_freqs,
376         NULL,
377 };
378
379
380 static struct cpufreq_driver speedstep_driver = {
381         .name   = "speedstep-ich",
382         .verify = speedstep_verify,
383         .target = speedstep_target,
384         .init   = speedstep_cpu_init,
385         .exit   = speedstep_cpu_exit,
386         .get    = speedstep_get,
387         .owner  = THIS_MODULE,
388         .attr   = speedstep_attr,
389 };
390
391
392 /**
393  * speedstep_init - initializes the SpeedStep CPUFreq driver
394  *
395  *   Initializes the SpeedStep support. Returns -ENODEV on unsupported
396  * devices, -EINVAL on problems during initiatization, and zero on
397  * success.
398  */
399 static int __init speedstep_init(void)
400 {
401         /* detect processor */
402         speedstep_processor = speedstep_detect_processor();
403         if (!speedstep_processor) {
404                 pr_debug("Intel(R) SpeedStep(TM) capable processor "
405                                 "not found\n");
406                 return -ENODEV;
407         }
408
409         /* detect chipset */
410         if (!speedstep_detect_chipset()) {
411                 pr_debug("Intel(R) SpeedStep(TM) for this chipset not "
412                                 "(yet) available.\n");
413                 return -ENODEV;
414         }
415
416         /* activate speedstep support */
417         if (speedstep_activate()) {
418                 pci_dev_put(speedstep_chipset_dev);
419                 return -EINVAL;
420         }
421
422         if (speedstep_find_register())
423                 return -ENODEV;
424
425         return cpufreq_register_driver(&speedstep_driver);
426 }
427
428
429 /**
430  * speedstep_exit - unregisters SpeedStep support
431  *
432  *   Unregisters SpeedStep support.
433  */
434 static void __exit speedstep_exit(void)
435 {
436         pci_dev_put(speedstep_chipset_dev);
437         cpufreq_unregister_driver(&speedstep_driver);
438 }
439
440
441 MODULE_AUTHOR("Dave Jones <davej@redhat.com>, "
442                 "Dominik Brodowski <linux@brodo.de>");
443 MODULE_DESCRIPTION("Speedstep driver for Intel mobile processors on chipsets "
444                 "with ICH-M southbridges.");
445 MODULE_LICENSE("GPL");
446
447 module_init(speedstep_init);
448 module_exit(speedstep_exit);