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0f1d683f NC |
1 | /* |
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> | |
5a0e3ad6 | 33 | #include <linux/slab.h> |
0f1d683f NC |
34 | |
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 | ||
42 | #define PCC_VERSION "1.00.00" | |
43 | #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 | ||
51 | #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, \ | |
52 | "pcc-cpufreq", msg) | |
53 | ||
54 | struct pcc_register_resource { | |
55 | u8 descriptor; | |
56 | u16 length; | |
57 | u8 space_id; | |
58 | u8 bit_width; | |
59 | u8 bit_offset; | |
60 | u8 access_size; | |
61 | u64 address; | |
62 | } __attribute__ ((packed)); | |
63 | ||
64 | struct pcc_memory_resource { | |
65 | u8 descriptor; | |
66 | u16 length; | |
67 | u8 space_id; | |
68 | u8 resource_usage; | |
69 | u8 type_specific; | |
70 | u64 granularity; | |
71 | u64 minimum; | |
72 | u64 maximum; | |
73 | u64 translation_offset; | |
74 | u64 address_length; | |
75 | } __attribute__ ((packed)); | |
76 | ||
77 | static struct cpufreq_driver pcc_cpufreq_driver; | |
78 | ||
79 | struct pcc_header { | |
80 | u32 signature; | |
81 | u16 length; | |
82 | u8 major; | |
83 | u8 minor; | |
84 | u32 features; | |
85 | u16 command; | |
86 | u16 status; | |
87 | u32 latency; | |
88 | u32 minimum_time; | |
89 | u32 maximum_time; | |
90 | u32 nominal; | |
91 | u32 throttled_frequency; | |
92 | u32 minimum_frequency; | |
93 | }; | |
94 | ||
95 | static void __iomem *pcch_virt_addr; | |
96 | static struct pcc_header __iomem *pcch_hdr; | |
97 | ||
98 | static DEFINE_SPINLOCK(pcc_lock); | |
99 | ||
100 | static struct acpi_generic_address doorbell; | |
101 | ||
102 | static u64 doorbell_preserve; | |
103 | static u64 doorbell_write; | |
104 | ||
105 | static u8 OSC_UUID[16] = {0x63, 0x9B, 0x2C, 0x9F, 0x70, 0x91, 0x49, 0x1f, | |
106 | 0xBB, 0x4F, 0xA5, 0x98, 0x2F, 0xA1, 0xB5, 0x46}; | |
107 | ||
108 | struct pcc_cpu { | |
109 | u32 input_offset; | |
110 | u32 output_offset; | |
111 | }; | |
112 | ||
113 | static struct pcc_cpu *pcc_cpu_info; | |
114 | ||
115 | static int pcc_cpufreq_verify(struct cpufreq_policy *policy) | |
116 | { | |
117 | cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, | |
118 | policy->cpuinfo.max_freq); | |
119 | return 0; | |
120 | } | |
121 | ||
122 | static inline void pcc_cmd(void) | |
123 | { | |
124 | u64 doorbell_value; | |
125 | int i; | |
126 | ||
127 | acpi_read(&doorbell_value, &doorbell); | |
128 | acpi_write((doorbell_value & doorbell_preserve) | doorbell_write, | |
129 | &doorbell); | |
130 | ||
131 | for (i = 0; i < POLL_LOOPS; i++) { | |
132 | if (ioread16(&pcch_hdr->status) & CMD_COMPLETE) | |
133 | break; | |
134 | } | |
135 | } | |
136 | ||
137 | static inline void pcc_clear_mapping(void) | |
138 | { | |
139 | if (pcch_virt_addr) | |
140 | iounmap(pcch_virt_addr); | |
141 | pcch_virt_addr = NULL; | |
142 | } | |
143 | ||
144 | static unsigned int pcc_get_freq(unsigned int cpu) | |
145 | { | |
146 | struct pcc_cpu *pcc_cpu_data; | |
147 | unsigned int curr_freq; | |
148 | unsigned int freq_limit; | |
149 | u16 status; | |
150 | u32 input_buffer; | |
151 | u32 output_buffer; | |
152 | ||
153 | spin_lock(&pcc_lock); | |
154 | ||
155 | dprintk("get: get_freq for CPU %d\n", cpu); | |
156 | pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu); | |
157 | ||
158 | input_buffer = 0x1; | |
159 | iowrite32(input_buffer, | |
160 | (pcch_virt_addr + pcc_cpu_data->input_offset)); | |
161 | iowrite16(CMD_GET_FREQ, &pcch_hdr->command); | |
162 | ||
163 | pcc_cmd(); | |
164 | ||
165 | output_buffer = | |
166 | ioread32(pcch_virt_addr + pcc_cpu_data->output_offset); | |
167 | ||
168 | /* Clear the input buffer - we are done with the current command */ | |
169 | memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ); | |
170 | ||
171 | status = ioread16(&pcch_hdr->status); | |
172 | if (status != CMD_COMPLETE) { | |
173 | dprintk("get: FAILED: for CPU %d, status is %d\n", | |
174 | cpu, status); | |
175 | goto cmd_incomplete; | |
176 | } | |
177 | iowrite16(0, &pcch_hdr->status); | |
178 | curr_freq = (((ioread32(&pcch_hdr->nominal) * (output_buffer & 0xff)) | |
179 | / 100) * 1000); | |
180 | ||
181 | dprintk("get: SUCCESS: (virtual) output_offset for cpu %d is " | |
182 | "0x%x, contains a value of: 0x%x. Speed is: %d MHz\n", | |
183 | cpu, (pcch_virt_addr + pcc_cpu_data->output_offset), | |
184 | output_buffer, curr_freq); | |
185 | ||
186 | freq_limit = (output_buffer >> 8) & 0xff; | |
187 | if (freq_limit != 0xff) { | |
188 | dprintk("get: frequency for cpu %d is being temporarily" | |
189 | " capped at %d\n", cpu, curr_freq); | |
190 | } | |
191 | ||
192 | spin_unlock(&pcc_lock); | |
193 | return curr_freq; | |
194 | ||
195 | cmd_incomplete: | |
196 | iowrite16(0, &pcch_hdr->status); | |
197 | spin_unlock(&pcc_lock); | |
198 | return -EINVAL; | |
199 | } | |
200 | ||
201 | static int pcc_cpufreq_target(struct cpufreq_policy *policy, | |
202 | unsigned int target_freq, | |
203 | unsigned int relation) | |
204 | { | |
205 | struct pcc_cpu *pcc_cpu_data; | |
206 | struct cpufreq_freqs freqs; | |
207 | u16 status; | |
208 | u32 input_buffer; | |
209 | int cpu; | |
210 | ||
211 | spin_lock(&pcc_lock); | |
212 | cpu = policy->cpu; | |
213 | pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu); | |
214 | ||
215 | dprintk("target: CPU %d should go to target freq: %d " | |
216 | "(virtual) input_offset is 0x%x\n", | |
217 | cpu, target_freq, | |
218 | (pcch_virt_addr + pcc_cpu_data->input_offset)); | |
219 | ||
220 | freqs.new = target_freq; | |
221 | freqs.cpu = cpu; | |
222 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
223 | ||
224 | input_buffer = 0x1 | (((target_freq * 100) | |
225 | / (ioread32(&pcch_hdr->nominal) * 1000)) << 8); | |
226 | iowrite32(input_buffer, | |
227 | (pcch_virt_addr + pcc_cpu_data->input_offset)); | |
228 | iowrite16(CMD_SET_FREQ, &pcch_hdr->command); | |
229 | ||
230 | pcc_cmd(); | |
231 | ||
232 | /* Clear the input buffer - we are done with the current command */ | |
233 | memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ); | |
234 | ||
235 | status = ioread16(&pcch_hdr->status); | |
236 | if (status != CMD_COMPLETE) { | |
237 | dprintk("target: FAILED for cpu %d, with status: 0x%x\n", | |
238 | cpu, status); | |
239 | goto cmd_incomplete; | |
240 | } | |
241 | iowrite16(0, &pcch_hdr->status); | |
242 | ||
243 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
244 | dprintk("target: was SUCCESSFUL for cpu %d\n", cpu); | |
245 | spin_unlock(&pcc_lock); | |
246 | ||
247 | return 0; | |
248 | ||
249 | cmd_incomplete: | |
250 | iowrite16(0, &pcch_hdr->status); | |
251 | spin_unlock(&pcc_lock); | |
252 | return -EINVAL; | |
253 | } | |
254 | ||
255 | static int pcc_get_offset(int cpu) | |
256 | { | |
257 | acpi_status status; | |
258 | struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; | |
259 | union acpi_object *pccp, *offset; | |
260 | struct pcc_cpu *pcc_cpu_data; | |
261 | struct acpi_processor *pr; | |
262 | int ret = 0; | |
263 | ||
264 | pr = per_cpu(processors, cpu); | |
265 | pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu); | |
266 | ||
267 | status = acpi_evaluate_object(pr->handle, "PCCP", NULL, &buffer); | |
268 | if (ACPI_FAILURE(status)) | |
269 | return -ENODEV; | |
270 | ||
271 | pccp = buffer.pointer; | |
272 | if (!pccp || pccp->type != ACPI_TYPE_PACKAGE) { | |
273 | ret = -ENODEV; | |
274 | goto out_free; | |
275 | }; | |
276 | ||
277 | offset = &(pccp->package.elements[0]); | |
278 | if (!offset || offset->type != ACPI_TYPE_INTEGER) { | |
279 | ret = -ENODEV; | |
280 | goto out_free; | |
281 | } | |
282 | ||
283 | pcc_cpu_data->input_offset = offset->integer.value; | |
284 | ||
285 | offset = &(pccp->package.elements[1]); | |
286 | if (!offset || offset->type != ACPI_TYPE_INTEGER) { | |
287 | ret = -ENODEV; | |
288 | goto out_free; | |
289 | } | |
290 | ||
291 | pcc_cpu_data->output_offset = offset->integer.value; | |
292 | ||
293 | memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ); | |
294 | memset_io((pcch_virt_addr + pcc_cpu_data->output_offset), 0, BUF_SZ); | |
295 | ||
296 | dprintk("pcc_get_offset: for CPU %d: pcc_cpu_data " | |
297 | "input_offset: 0x%x, pcc_cpu_data output_offset: 0x%x\n", | |
298 | cpu, pcc_cpu_data->input_offset, pcc_cpu_data->output_offset); | |
299 | out_free: | |
300 | kfree(buffer.pointer); | |
301 | return ret; | |
302 | } | |
303 | ||
304 | static int __init pcc_cpufreq_do_osc(acpi_handle *handle) | |
305 | { | |
306 | acpi_status status; | |
307 | struct acpi_object_list input; | |
308 | struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL}; | |
309 | union acpi_object in_params[4]; | |
310 | union acpi_object *out_obj; | |
311 | u32 capabilities[2]; | |
312 | u32 errors; | |
313 | u32 supported; | |
314 | int ret = 0; | |
315 | ||
316 | input.count = 4; | |
317 | input.pointer = in_params; | |
318 | input.count = 4; | |
319 | input.pointer = in_params; | |
320 | in_params[0].type = ACPI_TYPE_BUFFER; | |
321 | in_params[0].buffer.length = 16; | |
322 | in_params[0].buffer.pointer = OSC_UUID; | |
323 | in_params[1].type = ACPI_TYPE_INTEGER; | |
324 | in_params[1].integer.value = 1; | |
325 | in_params[2].type = ACPI_TYPE_INTEGER; | |
326 | in_params[2].integer.value = 2; | |
327 | in_params[3].type = ACPI_TYPE_BUFFER; | |
328 | in_params[3].buffer.length = 8; | |
329 | in_params[3].buffer.pointer = (u8 *)&capabilities; | |
330 | ||
331 | capabilities[0] = OSC_QUERY_ENABLE; | |
332 | capabilities[1] = 0x1; | |
333 | ||
334 | status = acpi_evaluate_object(*handle, "_OSC", &input, &output); | |
335 | if (ACPI_FAILURE(status)) | |
336 | return -ENODEV; | |
337 | ||
338 | if (!output.length) | |
339 | return -ENODEV; | |
340 | ||
341 | out_obj = output.pointer; | |
342 | if (out_obj->type != ACPI_TYPE_BUFFER) { | |
343 | ret = -ENODEV; | |
344 | goto out_free; | |
345 | } | |
346 | ||
347 | errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0); | |
348 | if (errors) { | |
349 | ret = -ENODEV; | |
350 | goto out_free; | |
351 | } | |
352 | ||
353 | supported = *((u32 *)(out_obj->buffer.pointer + 4)); | |
354 | if (!(supported & 0x1)) { | |
355 | ret = -ENODEV; | |
356 | goto out_free; | |
357 | } | |
358 | ||
359 | kfree(output.pointer); | |
360 | capabilities[0] = 0x0; | |
361 | capabilities[1] = 0x1; | |
362 | ||
363 | status = acpi_evaluate_object(*handle, "_OSC", &input, &output); | |
364 | if (ACPI_FAILURE(status)) | |
365 | return -ENODEV; | |
366 | ||
367 | if (!output.length) | |
368 | return -ENODEV; | |
369 | ||
370 | out_obj = output.pointer; | |
3847d223 DB |
371 | if (out_obj->type != ACPI_TYPE_BUFFER) |
372 | return -ENODEV; | |
0f1d683f NC |
373 | |
374 | errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0); | |
3847d223 DB |
375 | if (errors) |
376 | return -ENODEV; | |
0f1d683f NC |
377 | |
378 | supported = *((u32 *)(out_obj->buffer.pointer + 4)); | |
3847d223 DB |
379 | if (!(supported & 0x1)) |
380 | return -ENODEV; | |
0f1d683f NC |
381 | |
382 | out_free: | |
383 | kfree(output.pointer); | |
384 | return ret; | |
385 | } | |
386 | ||
387 | static int __init pcc_cpufreq_probe(void) | |
388 | { | |
389 | acpi_status status; | |
390 | struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL}; | |
391 | struct pcc_memory_resource *mem_resource; | |
392 | struct pcc_register_resource *reg_resource; | |
393 | union acpi_object *out_obj, *member; | |
47f8bcf3 | 394 | acpi_handle handle, osc_handle, pcch_handle; |
0f1d683f NC |
395 | int ret = 0; |
396 | ||
397 | status = acpi_get_handle(NULL, "\\_SB", &handle); | |
398 | if (ACPI_FAILURE(status)) | |
399 | return -ENODEV; | |
400 | ||
47f8bcf3 MG |
401 | status = acpi_get_handle(handle, "PCCH", &pcch_handle); |
402 | if (ACPI_FAILURE(status)) | |
403 | return -ENODEV; | |
404 | ||
0f1d683f NC |
405 | status = acpi_get_handle(handle, "_OSC", &osc_handle); |
406 | if (ACPI_SUCCESS(status)) { | |
407 | ret = pcc_cpufreq_do_osc(&osc_handle); | |
408 | if (ret) | |
409 | dprintk("probe: _OSC evaluation did not succeed\n"); | |
410 | /* Firmware's use of _OSC is optional */ | |
411 | ret = 0; | |
412 | } | |
413 | ||
414 | status = acpi_evaluate_object(handle, "PCCH", NULL, &output); | |
415 | if (ACPI_FAILURE(status)) | |
416 | return -ENODEV; | |
417 | ||
418 | out_obj = output.pointer; | |
419 | if (out_obj->type != ACPI_TYPE_PACKAGE) { | |
420 | ret = -ENODEV; | |
421 | goto out_free; | |
422 | } | |
423 | ||
424 | member = &out_obj->package.elements[0]; | |
425 | if (member->type != ACPI_TYPE_BUFFER) { | |
426 | ret = -ENODEV; | |
427 | goto out_free; | |
428 | } | |
429 | ||
430 | mem_resource = (struct pcc_memory_resource *)member->buffer.pointer; | |
431 | ||
432 | dprintk("probe: mem_resource descriptor: 0x%x," | |
433 | " length: %d, space_id: %d, resource_usage: %d," | |
434 | " type_specific: %d, granularity: 0x%llx," | |
435 | " minimum: 0x%llx, maximum: 0x%llx," | |
436 | " translation_offset: 0x%llx, address_length: 0x%llx\n", | |
437 | mem_resource->descriptor, mem_resource->length, | |
438 | mem_resource->space_id, mem_resource->resource_usage, | |
439 | mem_resource->type_specific, mem_resource->granularity, | |
440 | mem_resource->minimum, mem_resource->maximum, | |
441 | mem_resource->translation_offset, | |
442 | mem_resource->address_length); | |
443 | ||
444 | if (mem_resource->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) { | |
445 | ret = -ENODEV; | |
446 | goto out_free; | |
447 | } | |
448 | ||
449 | pcch_virt_addr = ioremap_nocache(mem_resource->minimum, | |
450 | mem_resource->address_length); | |
451 | if (pcch_virt_addr == NULL) { | |
452 | dprintk("probe: could not map shared mem region\n"); | |
453 | goto out_free; | |
454 | } | |
455 | pcch_hdr = pcch_virt_addr; | |
456 | ||
fb463593 | 457 | dprintk("probe: PCCH header (virtual) addr: 0x%p\n", pcch_hdr); |
0f1d683f NC |
458 | dprintk("probe: PCCH header is at physical address: 0x%llx," |
459 | " signature: 0x%x, length: %d bytes, major: %d, minor: %d," | |
460 | " supported features: 0x%x, command field: 0x%x," | |
461 | " status field: 0x%x, nominal latency: %d us\n", | |
462 | mem_resource->minimum, ioread32(&pcch_hdr->signature), | |
463 | ioread16(&pcch_hdr->length), ioread8(&pcch_hdr->major), | |
464 | ioread8(&pcch_hdr->minor), ioread32(&pcch_hdr->features), | |
465 | ioread16(&pcch_hdr->command), ioread16(&pcch_hdr->status), | |
466 | ioread32(&pcch_hdr->latency)); | |
467 | ||
468 | dprintk("probe: min time between commands: %d us," | |
469 | " max time between commands: %d us," | |
470 | " nominal CPU frequency: %d MHz," | |
471 | " minimum CPU frequency: %d MHz," | |
472 | " minimum CPU frequency without throttling: %d MHz\n", | |
473 | ioread32(&pcch_hdr->minimum_time), | |
474 | ioread32(&pcch_hdr->maximum_time), | |
475 | ioread32(&pcch_hdr->nominal), | |
476 | ioread32(&pcch_hdr->throttled_frequency), | |
477 | ioread32(&pcch_hdr->minimum_frequency)); | |
478 | ||
479 | member = &out_obj->package.elements[1]; | |
480 | if (member->type != ACPI_TYPE_BUFFER) { | |
481 | ret = -ENODEV; | |
482 | goto pcch_free; | |
483 | } | |
484 | ||
485 | reg_resource = (struct pcc_register_resource *)member->buffer.pointer; | |
486 | ||
487 | doorbell.space_id = reg_resource->space_id; | |
488 | doorbell.bit_width = reg_resource->bit_width; | |
489 | doorbell.bit_offset = reg_resource->bit_offset; | |
490 | doorbell.access_width = 64; | |
491 | doorbell.address = reg_resource->address; | |
492 | ||
493 | dprintk("probe: doorbell: space_id is %d, bit_width is %d, " | |
494 | "bit_offset is %d, access_width is %d, address is 0x%llx\n", | |
495 | doorbell.space_id, doorbell.bit_width, doorbell.bit_offset, | |
496 | doorbell.access_width, reg_resource->address); | |
497 | ||
498 | member = &out_obj->package.elements[2]; | |
499 | if (member->type != ACPI_TYPE_INTEGER) { | |
500 | ret = -ENODEV; | |
501 | goto pcch_free; | |
502 | } | |
503 | ||
504 | doorbell_preserve = member->integer.value; | |
505 | ||
506 | member = &out_obj->package.elements[3]; | |
507 | if (member->type != ACPI_TYPE_INTEGER) { | |
508 | ret = -ENODEV; | |
509 | goto pcch_free; | |
510 | } | |
511 | ||
512 | doorbell_write = member->integer.value; | |
513 | ||
514 | dprintk("probe: doorbell_preserve: 0x%llx," | |
515 | " doorbell_write: 0x%llx\n", | |
516 | doorbell_preserve, doorbell_write); | |
517 | ||
518 | pcc_cpu_info = alloc_percpu(struct pcc_cpu); | |
519 | if (!pcc_cpu_info) { | |
520 | ret = -ENOMEM; | |
521 | goto pcch_free; | |
522 | } | |
523 | ||
524 | printk(KERN_DEBUG "pcc-cpufreq: (v%s) driver loaded with frequency" | |
525 | " limits: %d MHz, %d MHz\n", PCC_VERSION, | |
526 | ioread32(&pcch_hdr->minimum_frequency), | |
527 | ioread32(&pcch_hdr->nominal)); | |
528 | kfree(output.pointer); | |
529 | return ret; | |
530 | pcch_free: | |
531 | pcc_clear_mapping(); | |
532 | out_free: | |
533 | kfree(output.pointer); | |
534 | return ret; | |
535 | } | |
536 | ||
537 | static int pcc_cpufreq_cpu_init(struct cpufreq_policy *policy) | |
538 | { | |
539 | unsigned int cpu = policy->cpu; | |
540 | unsigned int result = 0; | |
541 | ||
542 | if (!pcch_virt_addr) { | |
543 | result = -1; | |
544 | goto pcch_null; | |
545 | } | |
546 | ||
547 | result = pcc_get_offset(cpu); | |
548 | if (result) { | |
549 | dprintk("init: PCCP evaluation failed\n"); | |
550 | goto free; | |
551 | } | |
552 | ||
553 | policy->max = policy->cpuinfo.max_freq = | |
554 | ioread32(&pcch_hdr->nominal) * 1000; | |
555 | policy->min = policy->cpuinfo.min_freq = | |
556 | ioread32(&pcch_hdr->minimum_frequency) * 1000; | |
557 | policy->cur = pcc_get_freq(cpu); | |
558 | ||
559 | dprintk("init: policy->max is %d, policy->min is %d\n", | |
560 | policy->max, policy->min); | |
561 | ||
562 | return 0; | |
563 | free: | |
564 | pcc_clear_mapping(); | |
565 | free_percpu(pcc_cpu_info); | |
566 | pcch_null: | |
567 | return result; | |
568 | } | |
569 | ||
570 | static int pcc_cpufreq_cpu_exit(struct cpufreq_policy *policy) | |
571 | { | |
572 | return 0; | |
573 | } | |
574 | ||
575 | static struct cpufreq_driver pcc_cpufreq_driver = { | |
576 | .flags = CPUFREQ_CONST_LOOPS, | |
577 | .get = pcc_get_freq, | |
578 | .verify = pcc_cpufreq_verify, | |
579 | .target = pcc_cpufreq_target, | |
580 | .init = pcc_cpufreq_cpu_init, | |
581 | .exit = pcc_cpufreq_cpu_exit, | |
582 | .name = "pcc-cpufreq", | |
583 | .owner = THIS_MODULE, | |
584 | }; | |
585 | ||
586 | static int __init pcc_cpufreq_init(void) | |
587 | { | |
588 | int ret; | |
589 | ||
590 | if (acpi_disabled) | |
591 | return 0; | |
592 | ||
593 | ret = pcc_cpufreq_probe(); | |
594 | if (ret) { | |
595 | dprintk("pcc_cpufreq_init: PCCH evaluation failed\n"); | |
596 | return ret; | |
597 | } | |
598 | ||
599 | ret = cpufreq_register_driver(&pcc_cpufreq_driver); | |
600 | ||
601 | return ret; | |
602 | } | |
603 | ||
604 | static void __exit pcc_cpufreq_exit(void) | |
605 | { | |
606 | cpufreq_unregister_driver(&pcc_cpufreq_driver); | |
607 | ||
608 | pcc_clear_mapping(); | |
609 | ||
610 | free_percpu(pcc_cpu_info); | |
611 | } | |
612 | ||
613 | MODULE_AUTHOR("Matthew Garrett, Naga Chumbalkar"); | |
614 | MODULE_VERSION(PCC_VERSION); | |
615 | MODULE_DESCRIPTION("Processor Clocking Control interface driver"); | |
616 | MODULE_LICENSE("GPL"); | |
617 | ||
618 | late_initcall(pcc_cpufreq_init); | |
619 | module_exit(pcc_cpufreq_exit); |