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Naga Chumbalkar0f1d6832009-12-17 20:18:27 +00001/*
2 * pcc-cpufreq.c - Processor Clocking Control firmware cpufreq interface
3 *
4 * Copyright (C) 2009 Red Hat, Matthew Garrett <mjg@redhat.com>
5 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
6 * Nagananda Chumbalkar <nagananda.chumbalkar@hp.com>
7 *
8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; version 2 of the License.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or NON
17 * INFRINGEMENT. See the GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 675 Mass Ave, Cambridge, MA 02139, USA.
22 *
23 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
24 */
25
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/init.h>
29#include <linux/smp.h>
30#include <linux/sched.h>
31#include <linux/cpufreq.h>
32#include <linux/compiler.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090033#include <linux/slab.h>
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +000034
35#include <linux/acpi.h>
36#include <linux/io.h>
37#include <linux/spinlock.h>
38#include <linux/uaccess.h>
39
40#include <acpi/processor.h>
41
Naga Chumbalkar904cc1e2011-04-26 17:05:18 +000042#define PCC_VERSION "1.10.00"
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +000043#define POLL_LOOPS 300
44
45#define CMD_COMPLETE 0x1
46#define CMD_GET_FREQ 0x0
47#define CMD_SET_FREQ 0x1
48
49#define BUF_SZ 4
50
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +000051struct pcc_register_resource {
52 u8 descriptor;
53 u16 length;
54 u8 space_id;
55 u8 bit_width;
56 u8 bit_offset;
57 u8 access_size;
58 u64 address;
59} __attribute__ ((packed));
60
61struct pcc_memory_resource {
62 u8 descriptor;
63 u16 length;
64 u8 space_id;
65 u8 resource_usage;
66 u8 type_specific;
67 u64 granularity;
68 u64 minimum;
69 u64 maximum;
70 u64 translation_offset;
71 u64 address_length;
72} __attribute__ ((packed));
73
74static struct cpufreq_driver pcc_cpufreq_driver;
75
76struct pcc_header {
77 u32 signature;
78 u16 length;
79 u8 major;
80 u8 minor;
81 u32 features;
82 u16 command;
83 u16 status;
84 u32 latency;
85 u32 minimum_time;
86 u32 maximum_time;
87 u32 nominal;
88 u32 throttled_frequency;
89 u32 minimum_frequency;
90};
91
92static void __iomem *pcch_virt_addr;
93static struct pcc_header __iomem *pcch_hdr;
94
95static DEFINE_SPINLOCK(pcc_lock);
96
97static struct acpi_generic_address doorbell;
98
99static u64 doorbell_preserve;
100static u64 doorbell_write;
101
Naga Chumbalkar904cc1e2011-04-26 17:05:18 +0000102static u8 OSC_UUID[16] = {0x9F, 0x2C, 0x9B, 0x63, 0x91, 0x70, 0x1f, 0x49,
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000103 0xBB, 0x4F, 0xA5, 0x98, 0x2F, 0xA1, 0xB5, 0x46};
104
105struct pcc_cpu {
106 u32 input_offset;
107 u32 output_offset;
108};
109
Namhyung Kima3da3232010-08-08 02:37:23 +0900110static struct pcc_cpu __percpu *pcc_cpu_info;
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000111
112static int pcc_cpufreq_verify(struct cpufreq_policy *policy)
113{
114 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
115 policy->cpuinfo.max_freq);
116 return 0;
117}
118
119static inline void pcc_cmd(void)
120{
121 u64 doorbell_value;
122 int i;
123
124 acpi_read(&doorbell_value, &doorbell);
125 acpi_write((doorbell_value & doorbell_preserve) | doorbell_write,
126 &doorbell);
127
128 for (i = 0; i < POLL_LOOPS; i++) {
129 if (ioread16(&pcch_hdr->status) & CMD_COMPLETE)
130 break;
131 }
132}
133
134static inline void pcc_clear_mapping(void)
135{
136 if (pcch_virt_addr)
137 iounmap(pcch_virt_addr);
138 pcch_virt_addr = NULL;
139}
140
141static unsigned int pcc_get_freq(unsigned int cpu)
142{
143 struct pcc_cpu *pcc_cpu_data;
144 unsigned int curr_freq;
145 unsigned int freq_limit;
146 u16 status;
147 u32 input_buffer;
148 u32 output_buffer;
149
150 spin_lock(&pcc_lock);
151
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200152 pr_debug("get: get_freq for CPU %d\n", cpu);
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000153 pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
154
155 input_buffer = 0x1;
156 iowrite32(input_buffer,
157 (pcch_virt_addr + pcc_cpu_data->input_offset));
158 iowrite16(CMD_GET_FREQ, &pcch_hdr->command);
159
160 pcc_cmd();
161
162 output_buffer =
163 ioread32(pcch_virt_addr + pcc_cpu_data->output_offset);
164
165 /* Clear the input buffer - we are done with the current command */
166 memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
167
168 status = ioread16(&pcch_hdr->status);
169 if (status != CMD_COMPLETE) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200170 pr_debug("get: FAILED: for CPU %d, status is %d\n",
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000171 cpu, status);
172 goto cmd_incomplete;
173 }
174 iowrite16(0, &pcch_hdr->status);
175 curr_freq = (((ioread32(&pcch_hdr->nominal) * (output_buffer & 0xff))
176 / 100) * 1000);
177
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200178 pr_debug("get: SUCCESS: (virtual) output_offset for cpu %d is "
179 "0x%p, contains a value of: 0x%x. Speed is: %d MHz\n",
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000180 cpu, (pcch_virt_addr + pcc_cpu_data->output_offset),
181 output_buffer, curr_freq);
182
183 freq_limit = (output_buffer >> 8) & 0xff;
184 if (freq_limit != 0xff) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200185 pr_debug("get: frequency for cpu %d is being temporarily"
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000186 " capped at %d\n", cpu, curr_freq);
187 }
188
189 spin_unlock(&pcc_lock);
190 return curr_freq;
191
192cmd_incomplete:
193 iowrite16(0, &pcch_hdr->status);
194 spin_unlock(&pcc_lock);
Naga Chumbalkar1f858ef2011-03-09 14:02:49 +0000195 return 0;
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000196}
197
198static int pcc_cpufreq_target(struct cpufreq_policy *policy,
199 unsigned int target_freq,
200 unsigned int relation)
201{
202 struct pcc_cpu *pcc_cpu_data;
203 struct cpufreq_freqs freqs;
204 u16 status;
205 u32 input_buffer;
206 int cpu;
207
208 spin_lock(&pcc_lock);
209 cpu = policy->cpu;
210 pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
211
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200212 pr_debug("target: CPU %d should go to target freq: %d "
213 "(virtual) input_offset is 0x%p\n",
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000214 cpu, target_freq,
215 (pcch_virt_addr + pcc_cpu_data->input_offset));
216
217 freqs.new = target_freq;
Viresh Kumarb43a7ff2013-03-24 11:56:43 +0530218 cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000219
220 input_buffer = 0x1 | (((target_freq * 100)
221 / (ioread32(&pcch_hdr->nominal) * 1000)) << 8);
222 iowrite32(input_buffer,
223 (pcch_virt_addr + pcc_cpu_data->input_offset));
224 iowrite16(CMD_SET_FREQ, &pcch_hdr->command);
225
226 pcc_cmd();
227
228 /* Clear the input buffer - we are done with the current command */
229 memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
230
231 status = ioread16(&pcch_hdr->status);
232 if (status != CMD_COMPLETE) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200233 pr_debug("target: FAILED for cpu %d, with status: 0x%x\n",
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000234 cpu, status);
235 goto cmd_incomplete;
236 }
237 iowrite16(0, &pcch_hdr->status);
238
Viresh Kumarb43a7ff2013-03-24 11:56:43 +0530239 cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200240 pr_debug("target: was SUCCESSFUL for cpu %d\n", cpu);
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000241 spin_unlock(&pcc_lock);
242
243 return 0;
244
245cmd_incomplete:
246 iowrite16(0, &pcch_hdr->status);
247 spin_unlock(&pcc_lock);
248 return -EINVAL;
249}
250
251static int pcc_get_offset(int cpu)
252{
253 acpi_status status;
254 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
255 union acpi_object *pccp, *offset;
256 struct pcc_cpu *pcc_cpu_data;
257 struct acpi_processor *pr;
258 int ret = 0;
259
260 pr = per_cpu(processors, cpu);
261 pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
262
Naga Chumbalkare71f5cc2011-09-14 16:22:23 -0700263 if (!pr)
264 return -ENODEV;
265
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000266 status = acpi_evaluate_object(pr->handle, "PCCP", NULL, &buffer);
267 if (ACPI_FAILURE(status))
268 return -ENODEV;
269
270 pccp = buffer.pointer;
271 if (!pccp || pccp->type != ACPI_TYPE_PACKAGE) {
272 ret = -ENODEV;
273 goto out_free;
274 };
275
276 offset = &(pccp->package.elements[0]);
277 if (!offset || offset->type != ACPI_TYPE_INTEGER) {
278 ret = -ENODEV;
279 goto out_free;
280 }
281
282 pcc_cpu_data->input_offset = offset->integer.value;
283
284 offset = &(pccp->package.elements[1]);
285 if (!offset || offset->type != ACPI_TYPE_INTEGER) {
286 ret = -ENODEV;
287 goto out_free;
288 }
289
290 pcc_cpu_data->output_offset = offset->integer.value;
291
292 memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
293 memset_io((pcch_virt_addr + pcc_cpu_data->output_offset), 0, BUF_SZ);
294
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200295 pr_debug("pcc_get_offset: for CPU %d: pcc_cpu_data "
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000296 "input_offset: 0x%x, pcc_cpu_data output_offset: 0x%x\n",
297 cpu, pcc_cpu_data->input_offset, pcc_cpu_data->output_offset);
298out_free:
299 kfree(buffer.pointer);
300 return ret;
301}
302
303static int __init pcc_cpufreq_do_osc(acpi_handle *handle)
304{
305 acpi_status status;
306 struct acpi_object_list input;
307 struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
308 union acpi_object in_params[4];
309 union acpi_object *out_obj;
310 u32 capabilities[2];
311 u32 errors;
312 u32 supported;
313 int ret = 0;
314
315 input.count = 4;
316 input.pointer = in_params;
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000317 in_params[0].type = ACPI_TYPE_BUFFER;
318 in_params[0].buffer.length = 16;
319 in_params[0].buffer.pointer = OSC_UUID;
320 in_params[1].type = ACPI_TYPE_INTEGER;
321 in_params[1].integer.value = 1;
322 in_params[2].type = ACPI_TYPE_INTEGER;
323 in_params[2].integer.value = 2;
324 in_params[3].type = ACPI_TYPE_BUFFER;
325 in_params[3].buffer.length = 8;
326 in_params[3].buffer.pointer = (u8 *)&capabilities;
327
328 capabilities[0] = OSC_QUERY_ENABLE;
329 capabilities[1] = 0x1;
330
331 status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
332 if (ACPI_FAILURE(status))
333 return -ENODEV;
334
335 if (!output.length)
336 return -ENODEV;
337
338 out_obj = output.pointer;
339 if (out_obj->type != ACPI_TYPE_BUFFER) {
340 ret = -ENODEV;
341 goto out_free;
342 }
343
344 errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
345 if (errors) {
346 ret = -ENODEV;
347 goto out_free;
348 }
349
350 supported = *((u32 *)(out_obj->buffer.pointer + 4));
351 if (!(supported & 0x1)) {
352 ret = -ENODEV;
353 goto out_free;
354 }
355
356 kfree(output.pointer);
357 capabilities[0] = 0x0;
358 capabilities[1] = 0x1;
359
360 status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
361 if (ACPI_FAILURE(status))
362 return -ENODEV;
363
364 if (!output.length)
365 return -ENODEV;
366
367 out_obj = output.pointer;
Pekka Enberg36829302010-09-30 22:57:33 +0300368 if (out_obj->type != ACPI_TYPE_BUFFER) {
369 ret = -ENODEV;
370 goto out_free;
371 }
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000372
373 errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
Pekka Enberg36829302010-09-30 22:57:33 +0300374 if (errors) {
375 ret = -ENODEV;
376 goto out_free;
377 }
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000378
379 supported = *((u32 *)(out_obj->buffer.pointer + 4));
Pekka Enberg36829302010-09-30 22:57:33 +0300380 if (!(supported & 0x1)) {
381 ret = -ENODEV;
382 goto out_free;
383 }
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000384
385out_free:
386 kfree(output.pointer);
387 return ret;
388}
389
390static int __init pcc_cpufreq_probe(void)
391{
392 acpi_status status;
393 struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
394 struct pcc_memory_resource *mem_resource;
395 struct pcc_register_resource *reg_resource;
396 union acpi_object *out_obj, *member;
Matthew Garrett47f8bcf2010-07-20 13:52:00 -0400397 acpi_handle handle, osc_handle, pcch_handle;
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000398 int ret = 0;
399
400 status = acpi_get_handle(NULL, "\\_SB", &handle);
401 if (ACPI_FAILURE(status))
402 return -ENODEV;
403
Matthew Garrett47f8bcf2010-07-20 13:52:00 -0400404 status = acpi_get_handle(handle, "PCCH", &pcch_handle);
405 if (ACPI_FAILURE(status))
406 return -ENODEV;
407
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000408 status = acpi_get_handle(handle, "_OSC", &osc_handle);
409 if (ACPI_SUCCESS(status)) {
410 ret = pcc_cpufreq_do_osc(&osc_handle);
411 if (ret)
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200412 pr_debug("probe: _OSC evaluation did not succeed\n");
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000413 /* Firmware's use of _OSC is optional */
414 ret = 0;
415 }
416
417 status = acpi_evaluate_object(handle, "PCCH", NULL, &output);
418 if (ACPI_FAILURE(status))
419 return -ENODEV;
420
421 out_obj = output.pointer;
422 if (out_obj->type != ACPI_TYPE_PACKAGE) {
423 ret = -ENODEV;
424 goto out_free;
425 }
426
427 member = &out_obj->package.elements[0];
428 if (member->type != ACPI_TYPE_BUFFER) {
429 ret = -ENODEV;
430 goto out_free;
431 }
432
433 mem_resource = (struct pcc_memory_resource *)member->buffer.pointer;
434
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200435 pr_debug("probe: mem_resource descriptor: 0x%x,"
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000436 " length: %d, space_id: %d, resource_usage: %d,"
437 " type_specific: %d, granularity: 0x%llx,"
438 " minimum: 0x%llx, maximum: 0x%llx,"
439 " translation_offset: 0x%llx, address_length: 0x%llx\n",
440 mem_resource->descriptor, mem_resource->length,
441 mem_resource->space_id, mem_resource->resource_usage,
442 mem_resource->type_specific, mem_resource->granularity,
443 mem_resource->minimum, mem_resource->maximum,
444 mem_resource->translation_offset,
445 mem_resource->address_length);
446
447 if (mem_resource->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
448 ret = -ENODEV;
449 goto out_free;
450 }
451
452 pcch_virt_addr = ioremap_nocache(mem_resource->minimum,
453 mem_resource->address_length);
454 if (pcch_virt_addr == NULL) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200455 pr_debug("probe: could not map shared mem region\n");
Julia Lawalld06a8a42012-08-05 22:56:43 +0200456 ret = -ENOMEM;
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000457 goto out_free;
458 }
459 pcch_hdr = pcch_virt_addr;
460
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200461 pr_debug("probe: PCCH header (virtual) addr: 0x%p\n", pcch_hdr);
462 pr_debug("probe: PCCH header is at physical address: 0x%llx,"
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000463 " signature: 0x%x, length: %d bytes, major: %d, minor: %d,"
464 " supported features: 0x%x, command field: 0x%x,"
465 " status field: 0x%x, nominal latency: %d us\n",
466 mem_resource->minimum, ioread32(&pcch_hdr->signature),
467 ioread16(&pcch_hdr->length), ioread8(&pcch_hdr->major),
468 ioread8(&pcch_hdr->minor), ioread32(&pcch_hdr->features),
469 ioread16(&pcch_hdr->command), ioread16(&pcch_hdr->status),
470 ioread32(&pcch_hdr->latency));
471
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200472 pr_debug("probe: min time between commands: %d us,"
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000473 " max time between commands: %d us,"
474 " nominal CPU frequency: %d MHz,"
475 " minimum CPU frequency: %d MHz,"
476 " minimum CPU frequency without throttling: %d MHz\n",
477 ioread32(&pcch_hdr->minimum_time),
478 ioread32(&pcch_hdr->maximum_time),
479 ioread32(&pcch_hdr->nominal),
480 ioread32(&pcch_hdr->throttled_frequency),
481 ioread32(&pcch_hdr->minimum_frequency));
482
483 member = &out_obj->package.elements[1];
484 if (member->type != ACPI_TYPE_BUFFER) {
485 ret = -ENODEV;
486 goto pcch_free;
487 }
488
489 reg_resource = (struct pcc_register_resource *)member->buffer.pointer;
490
491 doorbell.space_id = reg_resource->space_id;
492 doorbell.bit_width = reg_resource->bit_width;
493 doorbell.bit_offset = reg_resource->bit_offset;
494 doorbell.access_width = 64;
495 doorbell.address = reg_resource->address;
496
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200497 pr_debug("probe: doorbell: space_id is %d, bit_width is %d, "
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000498 "bit_offset is %d, access_width is %d, address is 0x%llx\n",
499 doorbell.space_id, doorbell.bit_width, doorbell.bit_offset,
500 doorbell.access_width, reg_resource->address);
501
502 member = &out_obj->package.elements[2];
503 if (member->type != ACPI_TYPE_INTEGER) {
504 ret = -ENODEV;
505 goto pcch_free;
506 }
507
508 doorbell_preserve = member->integer.value;
509
510 member = &out_obj->package.elements[3];
511 if (member->type != ACPI_TYPE_INTEGER) {
512 ret = -ENODEV;
513 goto pcch_free;
514 }
515
516 doorbell_write = member->integer.value;
517
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200518 pr_debug("probe: doorbell_preserve: 0x%llx,"
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000519 " doorbell_write: 0x%llx\n",
520 doorbell_preserve, doorbell_write);
521
522 pcc_cpu_info = alloc_percpu(struct pcc_cpu);
523 if (!pcc_cpu_info) {
524 ret = -ENOMEM;
525 goto pcch_free;
526 }
527
528 printk(KERN_DEBUG "pcc-cpufreq: (v%s) driver loaded with frequency"
529 " limits: %d MHz, %d MHz\n", PCC_VERSION,
530 ioread32(&pcch_hdr->minimum_frequency),
531 ioread32(&pcch_hdr->nominal));
532 kfree(output.pointer);
533 return ret;
534pcch_free:
535 pcc_clear_mapping();
536out_free:
537 kfree(output.pointer);
538 return ret;
539}
540
541static int pcc_cpufreq_cpu_init(struct cpufreq_policy *policy)
542{
543 unsigned int cpu = policy->cpu;
544 unsigned int result = 0;
545
546 if (!pcch_virt_addr) {
547 result = -1;
Matthew Garrett179ee432010-07-15 11:44:00 -0400548 goto out;
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000549 }
550
551 result = pcc_get_offset(cpu);
552 if (result) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200553 pr_debug("init: PCCP evaluation failed\n");
Matthew Garrett179ee432010-07-15 11:44:00 -0400554 goto out;
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000555 }
556
557 policy->max = policy->cpuinfo.max_freq =
558 ioread32(&pcch_hdr->nominal) * 1000;
559 policy->min = policy->cpuinfo.min_freq =
560 ioread32(&pcch_hdr->minimum_frequency) * 1000;
561 policy->cur = pcc_get_freq(cpu);
562
Matthew Garrett179ee432010-07-15 11:44:00 -0400563 if (!policy->cur) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200564 pr_debug("init: Unable to get current CPU frequency\n");
Matthew Garrett179ee432010-07-15 11:44:00 -0400565 result = -EINVAL;
566 goto out;
567 }
568
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200569 pr_debug("init: policy->max is %d, policy->min is %d\n",
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000570 policy->max, policy->min);
Matthew Garrett179ee432010-07-15 11:44:00 -0400571out:
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000572 return result;
573}
574
575static int pcc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
576{
577 return 0;
578}
579
580static struct cpufreq_driver pcc_cpufreq_driver = {
581 .flags = CPUFREQ_CONST_LOOPS,
582 .get = pcc_get_freq,
583 .verify = pcc_cpufreq_verify,
584 .target = pcc_cpufreq_target,
585 .init = pcc_cpufreq_cpu_init,
586 .exit = pcc_cpufreq_cpu_exit,
587 .name = "pcc-cpufreq",
588 .owner = THIS_MODULE,
589};
590
591static int __init pcc_cpufreq_init(void)
592{
593 int ret;
594
595 if (acpi_disabled)
596 return 0;
597
598 ret = pcc_cpufreq_probe();
599 if (ret) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200600 pr_debug("pcc_cpufreq_init: PCCH evaluation failed\n");
Naga Chumbalkar0f1d6832009-12-17 20:18:27 +0000601 return ret;
602 }
603
604 ret = cpufreq_register_driver(&pcc_cpufreq_driver);
605
606 return ret;
607}
608
609static void __exit pcc_cpufreq_exit(void)
610{
611 cpufreq_unregister_driver(&pcc_cpufreq_driver);
612
613 pcc_clear_mapping();
614
615 free_percpu(pcc_cpu_info);
616}
617
618MODULE_AUTHOR("Matthew Garrett, Naga Chumbalkar");
619MODULE_VERSION(PCC_VERSION);
620MODULE_DESCRIPTION("Processor Clocking Control interface driver");
621MODULE_LICENSE("GPL");
622
623late_initcall(pcc_cpufreq_init);
624module_exit(pcc_cpufreq_exit);