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>
33 #include <linux/slab.h>
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	"1.10.00"
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 struct 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 
61 struct 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 
74 static struct cpufreq_driver pcc_cpufreq_driver;
75 
76 struct 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 
92 static void __iomem *pcch_virt_addr;
93 static struct pcc_header __iomem *pcch_hdr;
94 
95 static DEFINE_SPINLOCK(pcc_lock);
96 
97 static struct acpi_generic_address doorbell;
98 
99 static u64 doorbell_preserve;
100 static u64 doorbell_write;
101 
102 static u8 OSC_UUID[16] = {0x9F, 0x2C, 0x9B, 0x63, 0x91, 0x70, 0x1f, 0x49,
103 			  0xBB, 0x4F, 0xA5, 0x98, 0x2F, 0xA1, 0xB5, 0x46};
104 
105 struct pcc_cpu {
106 	u32 input_offset;
107 	u32 output_offset;
108 };
109 
110 static struct pcc_cpu __percpu *pcc_cpu_info;
111 
pcc_cpufreq_verify(struct cpufreq_policy_data * policy)112 static int pcc_cpufreq_verify(struct cpufreq_policy_data *policy)
113 {
114 	cpufreq_verify_within_cpu_limits(policy);
115 	return 0;
116 }
117 
pcc_cmd(void)118 static inline void pcc_cmd(void)
119 {
120 	u64 doorbell_value;
121 	int i;
122 
123 	acpi_read(&doorbell_value, &doorbell);
124 	acpi_write((doorbell_value & doorbell_preserve) | doorbell_write,
125 		   &doorbell);
126 
127 	for (i = 0; i < POLL_LOOPS; i++) {
128 		if (ioread16(&pcch_hdr->status) & CMD_COMPLETE)
129 			break;
130 	}
131 }
132 
pcc_clear_mapping(void)133 static inline void pcc_clear_mapping(void)
134 {
135 	if (pcch_virt_addr)
136 		iounmap(pcch_virt_addr);
137 	pcch_virt_addr = NULL;
138 }
139 
pcc_get_freq(unsigned int cpu)140 static unsigned int pcc_get_freq(unsigned int cpu)
141 {
142 	struct pcc_cpu *pcc_cpu_data;
143 	unsigned int curr_freq;
144 	unsigned int freq_limit;
145 	u16 status;
146 	u32 input_buffer;
147 	u32 output_buffer;
148 
149 	spin_lock(&pcc_lock);
150 
151 	pr_debug("get: get_freq for CPU %d\n", cpu);
152 	pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
153 
154 	input_buffer = 0x1;
155 	iowrite32(input_buffer,
156 			(pcch_virt_addr + pcc_cpu_data->input_offset));
157 	iowrite16(CMD_GET_FREQ, &pcch_hdr->command);
158 
159 	pcc_cmd();
160 
161 	output_buffer =
162 		ioread32(pcch_virt_addr + pcc_cpu_data->output_offset);
163 
164 	/* Clear the input buffer - we are done with the current command */
165 	memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
166 
167 	status = ioread16(&pcch_hdr->status);
168 	if (status != CMD_COMPLETE) {
169 		pr_debug("get: FAILED: for CPU %d, status is %d\n",
170 			cpu, status);
171 		goto cmd_incomplete;
172 	}
173 	iowrite16(0, &pcch_hdr->status);
174 	curr_freq = (((ioread32(&pcch_hdr->nominal) * (output_buffer & 0xff))
175 			/ 100) * 1000);
176 
177 	pr_debug("get: SUCCESS: (virtual) output_offset for cpu %d is "
178 		"0x%p, contains a value of: 0x%x. Speed is: %d MHz\n",
179 		cpu, (pcch_virt_addr + pcc_cpu_data->output_offset),
180 		output_buffer, curr_freq);
181 
182 	freq_limit = (output_buffer >> 8) & 0xff;
183 	if (freq_limit != 0xff) {
184 		pr_debug("get: frequency for cpu %d is being temporarily"
185 			" capped at %d\n", cpu, curr_freq);
186 	}
187 
188 	spin_unlock(&pcc_lock);
189 	return curr_freq;
190 
191 cmd_incomplete:
192 	iowrite16(0, &pcch_hdr->status);
193 	spin_unlock(&pcc_lock);
194 	return 0;
195 }
196 
pcc_cpufreq_target(struct cpufreq_policy * policy,unsigned int target_freq,unsigned int relation)197 static int pcc_cpufreq_target(struct cpufreq_policy *policy,
198 			      unsigned int target_freq,
199 			      unsigned int relation)
200 {
201 	struct pcc_cpu *pcc_cpu_data;
202 	struct cpufreq_freqs freqs;
203 	u16 status;
204 	u32 input_buffer;
205 	int cpu;
206 
207 	cpu = policy->cpu;
208 	pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
209 
210 	pr_debug("target: CPU %d should go to target freq: %d "
211 		"(virtual) input_offset is 0x%p\n",
212 		cpu, target_freq,
213 		(pcch_virt_addr + pcc_cpu_data->input_offset));
214 
215 	freqs.old = policy->cur;
216 	freqs.new = target_freq;
217 	cpufreq_freq_transition_begin(policy, &freqs);
218 	spin_lock(&pcc_lock);
219 
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 	iowrite16(0, &pcch_hdr->status);
233 
234 	cpufreq_freq_transition_end(policy, &freqs, status != CMD_COMPLETE);
235 	spin_unlock(&pcc_lock);
236 
237 	if (status != CMD_COMPLETE) {
238 		pr_debug("target: FAILED for cpu %d, with status: 0x%x\n",
239 			cpu, status);
240 		return -EINVAL;
241 	}
242 
243 	pr_debug("target: was SUCCESSFUL for cpu %d\n", cpu);
244 
245 	return 0;
246 }
247 
pcc_get_offset(int cpu)248 static int pcc_get_offset(int cpu)
249 {
250 	acpi_status status;
251 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
252 	union acpi_object *pccp, *offset;
253 	struct pcc_cpu *pcc_cpu_data;
254 	struct acpi_processor *pr;
255 	int ret = 0;
256 
257 	pr = per_cpu(processors, cpu);
258 	pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
259 
260 	if (!pr)
261 		return -ENODEV;
262 
263 	status = acpi_evaluate_object(pr->handle, "PCCP", NULL, &buffer);
264 	if (ACPI_FAILURE(status))
265 		return -ENODEV;
266 
267 	pccp = buffer.pointer;
268 	if (!pccp || pccp->type != ACPI_TYPE_PACKAGE) {
269 		ret = -ENODEV;
270 		goto out_free;
271 	}
272 
273 	offset = &(pccp->package.elements[0]);
274 	if (!offset || offset->type != ACPI_TYPE_INTEGER) {
275 		ret = -ENODEV;
276 		goto out_free;
277 	}
278 
279 	pcc_cpu_data->input_offset = offset->integer.value;
280 
281 	offset = &(pccp->package.elements[1]);
282 	if (!offset || offset->type != ACPI_TYPE_INTEGER) {
283 		ret = -ENODEV;
284 		goto out_free;
285 	}
286 
287 	pcc_cpu_data->output_offset = offset->integer.value;
288 
289 	memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
290 	memset_io((pcch_virt_addr + pcc_cpu_data->output_offset), 0, BUF_SZ);
291 
292 	pr_debug("pcc_get_offset: for CPU %d: pcc_cpu_data "
293 		"input_offset: 0x%x, pcc_cpu_data output_offset: 0x%x\n",
294 		cpu, pcc_cpu_data->input_offset, pcc_cpu_data->output_offset);
295 out_free:
296 	kfree(buffer.pointer);
297 	return ret;
298 }
299 
pcc_cpufreq_do_osc(acpi_handle * handle)300 static int __init pcc_cpufreq_do_osc(acpi_handle *handle)
301 {
302 	acpi_status status;
303 	struct acpi_object_list input;
304 	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
305 	union acpi_object in_params[4];
306 	union acpi_object *out_obj;
307 	u32 capabilities[2];
308 	u32 errors;
309 	u32 supported;
310 	int ret = 0;
311 
312 	input.count = 4;
313 	input.pointer = in_params;
314 	in_params[0].type               = ACPI_TYPE_BUFFER;
315 	in_params[0].buffer.length      = 16;
316 	in_params[0].buffer.pointer     = OSC_UUID;
317 	in_params[1].type               = ACPI_TYPE_INTEGER;
318 	in_params[1].integer.value      = 1;
319 	in_params[2].type               = ACPI_TYPE_INTEGER;
320 	in_params[2].integer.value      = 2;
321 	in_params[3].type               = ACPI_TYPE_BUFFER;
322 	in_params[3].buffer.length      = 8;
323 	in_params[3].buffer.pointer     = (u8 *)&capabilities;
324 
325 	capabilities[0] = OSC_QUERY_ENABLE;
326 	capabilities[1] = 0x1;
327 
328 	status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
329 	if (ACPI_FAILURE(status))
330 		return -ENODEV;
331 
332 	if (!output.length)
333 		return -ENODEV;
334 
335 	out_obj = output.pointer;
336 	if (out_obj->type != ACPI_TYPE_BUFFER) {
337 		ret = -ENODEV;
338 		goto out_free;
339 	}
340 
341 	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
342 	if (errors) {
343 		ret = -ENODEV;
344 		goto out_free;
345 	}
346 
347 	supported = *((u32 *)(out_obj->buffer.pointer + 4));
348 	if (!(supported & 0x1)) {
349 		ret = -ENODEV;
350 		goto out_free;
351 	}
352 
353 	kfree(output.pointer);
354 	capabilities[0] = 0x0;
355 	capabilities[1] = 0x1;
356 
357 	status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
358 	if (ACPI_FAILURE(status))
359 		return -ENODEV;
360 
361 	if (!output.length)
362 		return -ENODEV;
363 
364 	out_obj = output.pointer;
365 	if (out_obj->type != ACPI_TYPE_BUFFER) {
366 		ret = -ENODEV;
367 		goto out_free;
368 	}
369 
370 	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
371 	if (errors) {
372 		ret = -ENODEV;
373 		goto out_free;
374 	}
375 
376 	supported = *((u32 *)(out_obj->buffer.pointer + 4));
377 	if (!(supported & 0x1)) {
378 		ret = -ENODEV;
379 		goto out_free;
380 	}
381 
382 out_free:
383 	kfree(output.pointer);
384 	return ret;
385 }
386 
pcc_cpufreq_probe(void)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;
394 	acpi_handle handle, osc_handle;
395 	int ret = 0;
396 
397 	status = acpi_get_handle(NULL, "\\_SB", &handle);
398 	if (ACPI_FAILURE(status))
399 		return -ENODEV;
400 
401 	if (!acpi_has_method(handle, "PCCH"))
402 		return -ENODEV;
403 
404 	status = acpi_get_handle(handle, "_OSC", &osc_handle);
405 	if (ACPI_SUCCESS(status)) {
406 		ret = pcc_cpufreq_do_osc(&osc_handle);
407 		if (ret)
408 			pr_debug("probe: _OSC evaluation did not succeed\n");
409 		/* Firmware's use of _OSC is optional */
410 		ret = 0;
411 	}
412 
413 	status = acpi_evaluate_object(handle, "PCCH", NULL, &output);
414 	if (ACPI_FAILURE(status))
415 		return -ENODEV;
416 
417 	out_obj = output.pointer;
418 	if (out_obj->type != ACPI_TYPE_PACKAGE) {
419 		ret = -ENODEV;
420 		goto out_free;
421 	}
422 
423 	member = &out_obj->package.elements[0];
424 	if (member->type != ACPI_TYPE_BUFFER) {
425 		ret = -ENODEV;
426 		goto out_free;
427 	}
428 
429 	mem_resource = (struct pcc_memory_resource *)member->buffer.pointer;
430 
431 	pr_debug("probe: mem_resource descriptor: 0x%x,"
432 		" length: %d, space_id: %d, resource_usage: %d,"
433 		" type_specific: %d, granularity: 0x%llx,"
434 		" minimum: 0x%llx, maximum: 0x%llx,"
435 		" translation_offset: 0x%llx, address_length: 0x%llx\n",
436 		mem_resource->descriptor, mem_resource->length,
437 		mem_resource->space_id, mem_resource->resource_usage,
438 		mem_resource->type_specific, mem_resource->granularity,
439 		mem_resource->minimum, mem_resource->maximum,
440 		mem_resource->translation_offset,
441 		mem_resource->address_length);
442 
443 	if (mem_resource->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
444 		ret = -ENODEV;
445 		goto out_free;
446 	}
447 
448 	pcch_virt_addr = ioremap(mem_resource->minimum,
449 					mem_resource->address_length);
450 	if (pcch_virt_addr == NULL) {
451 		pr_debug("probe: could not map shared mem region\n");
452 		ret = -ENOMEM;
453 		goto out_free;
454 	}
455 	pcch_hdr = pcch_virt_addr;
456 
457 	pr_debug("probe: PCCH header (virtual) addr: 0x%p\n", pcch_hdr);
458 	pr_debug("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 	pr_debug("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 = 4;
491 	doorbell.address = reg_resource->address;
492 
493 	pr_debug("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 	pr_debug("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 
pcc_cpufreq_cpu_init(struct cpufreq_policy * policy)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 out;
545 	}
546 
547 	result = pcc_get_offset(cpu);
548 	if (result) {
549 		pr_debug("init: PCCP evaluation failed\n");
550 		goto out;
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 
558 	pr_debug("init: policy->max is %d, policy->min is %d\n",
559 		policy->max, policy->min);
560 out:
561 	return result;
562 }
563 
pcc_cpufreq_cpu_exit(struct cpufreq_policy * policy)564 static int pcc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
565 {
566 	return 0;
567 }
568 
569 static struct cpufreq_driver pcc_cpufreq_driver = {
570 	.flags = CPUFREQ_CONST_LOOPS,
571 	.get = pcc_get_freq,
572 	.verify = pcc_cpufreq_verify,
573 	.target = pcc_cpufreq_target,
574 	.init = pcc_cpufreq_cpu_init,
575 	.exit = pcc_cpufreq_cpu_exit,
576 	.name = "pcc-cpufreq",
577 };
578 
pcc_cpufreq_init(void)579 static int __init pcc_cpufreq_init(void)
580 {
581 	int ret;
582 
583 	/* Skip initialization if another cpufreq driver is there. */
584 	if (cpufreq_get_current_driver())
585 		return -EEXIST;
586 
587 	if (acpi_disabled)
588 		return -ENODEV;
589 
590 	ret = pcc_cpufreq_probe();
591 	if (ret) {
592 		pr_debug("pcc_cpufreq_init: PCCH evaluation failed\n");
593 		return ret;
594 	}
595 
596 	if (num_present_cpus() > 4) {
597 		pcc_cpufreq_driver.flags |= CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING;
598 		pr_err("%s: Too many CPUs, dynamic performance scaling disabled\n",
599 		       __func__);
600 		pr_err("%s: Try to enable another scaling driver through BIOS settings\n",
601 		       __func__);
602 		pr_err("%s: and complain to the system vendor\n", __func__);
603 	}
604 
605 	ret = cpufreq_register_driver(&pcc_cpufreq_driver);
606 
607 	return ret;
608 }
609 
pcc_cpufreq_exit(void)610 static void __exit pcc_cpufreq_exit(void)
611 {
612 	cpufreq_unregister_driver(&pcc_cpufreq_driver);
613 
614 	pcc_clear_mapping();
615 
616 	free_percpu(pcc_cpu_info);
617 }
618 
619 static const struct acpi_device_id __maybe_unused processor_device_ids[] = {
620 	{ACPI_PROCESSOR_OBJECT_HID, },
621 	{ACPI_PROCESSOR_DEVICE_HID, },
622 	{},
623 };
624 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
625 
626 MODULE_AUTHOR("Matthew Garrett, Naga Chumbalkar");
627 MODULE_VERSION(PCC_VERSION);
628 MODULE_DESCRIPTION("Processor Clocking Control interface driver");
629 MODULE_LICENSE("GPL");
630 
631 late_initcall(pcc_cpufreq_init);
632 module_exit(pcc_cpufreq_exit);
633