xref: /linux/drivers/cpufreq/qcom-cpufreq-nvmem.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2018, The Linux Foundation. All rights reserved.
4  */
5 
6 /*
7  * In Certain QCOM SoCs like apq8096 and msm8996 that have KRYO processors,
8  * the CPU frequency subset and voltage value of each OPP varies
9  * based on the silicon variant in use. Qualcomm Process Voltage Scaling Tables
10  * defines the voltage and frequency value based on the msm-id in SMEM
11  * and speedbin blown in the efuse combination.
12  * The qcom-cpufreq-nvmem driver reads the msm-id and efuse value from the SoC
13  * to provide the OPP framework with required information.
14  * This is used to determine the voltage and frequency value for each OPP of
15  * operating-points-v2 table when it is parsed by the OPP framework.
16  */
17 
18 #include <linux/cpu.h>
19 #include <linux/err.h>
20 #include <linux/init.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/nvmem-consumer.h>
24 #include <linux/of.h>
25 #include <linux/platform_device.h>
26 #include <linux/pm.h>
27 #include <linux/pm_domain.h>
28 #include <linux/pm_opp.h>
29 #include <linux/pm_runtime.h>
30 #include <linux/slab.h>
31 #include <linux/soc/qcom/smem.h>
32 
33 #include <dt-bindings/arm/qcom,ids.h>
34 
35 enum ipq806x_versions {
36 	IPQ8062_VERSION = 0,
37 	IPQ8064_VERSION,
38 	IPQ8065_VERSION,
39 };
40 
41 #define IPQ6000_VERSION	BIT(2)
42 
43 enum ipq8074_versions {
44 	IPQ8074_HAWKEYE_VERSION = 0,
45 	IPQ8074_ACORN_VERSION,
46 };
47 
48 struct qcom_cpufreq_drv;
49 
50 struct qcom_cpufreq_match_data {
51 	int (*get_version)(struct device *cpu_dev,
52 			   struct nvmem_cell *speedbin_nvmem,
53 			   char **pvs_name,
54 			   struct qcom_cpufreq_drv *drv);
55 	const char **pd_names;
56 	unsigned int num_pd_names;
57 };
58 
59 struct qcom_cpufreq_drv_cpu {
60 	int opp_token;
61 	struct dev_pm_domain_list *pd_list;
62 };
63 
64 struct qcom_cpufreq_drv {
65 	u32 versions;
66 	const struct qcom_cpufreq_match_data *data;
67 	struct qcom_cpufreq_drv_cpu cpus[];
68 };
69 
70 static struct platform_device *cpufreq_dt_pdev, *cpufreq_pdev;
71 
72 static int qcom_cpufreq_simple_get_version(struct device *cpu_dev,
73 					   struct nvmem_cell *speedbin_nvmem,
74 					   char **pvs_name,
75 					   struct qcom_cpufreq_drv *drv)
76 {
77 	u8 *speedbin;
78 
79 	*pvs_name = NULL;
80 	speedbin = nvmem_cell_read(speedbin_nvmem, NULL);
81 	if (IS_ERR(speedbin))
82 		return PTR_ERR(speedbin);
83 
84 	dev_dbg(cpu_dev, "speedbin: %d\n", *speedbin);
85 	drv->versions = 1 << *speedbin;
86 	kfree(speedbin);
87 	return 0;
88 }
89 
90 static void get_krait_bin_format_a(struct device *cpu_dev,
91 					  int *speed, int *pvs,
92 					  u8 *buf)
93 {
94 	u32 pte_efuse;
95 
96 	pte_efuse = *((u32 *)buf);
97 
98 	*speed = pte_efuse & 0xf;
99 	if (*speed == 0xf)
100 		*speed = (pte_efuse >> 4) & 0xf;
101 
102 	if (*speed == 0xf) {
103 		*speed = 0;
104 		dev_warn(cpu_dev, "Speed bin: Defaulting to %d\n", *speed);
105 	} else {
106 		dev_dbg(cpu_dev, "Speed bin: %d\n", *speed);
107 	}
108 
109 	*pvs = (pte_efuse >> 10) & 0x7;
110 	if (*pvs == 0x7)
111 		*pvs = (pte_efuse >> 13) & 0x7;
112 
113 	if (*pvs == 0x7) {
114 		*pvs = 0;
115 		dev_warn(cpu_dev, "PVS bin: Defaulting to %d\n", *pvs);
116 	} else {
117 		dev_dbg(cpu_dev, "PVS bin: %d\n", *pvs);
118 	}
119 }
120 
121 static void get_krait_bin_format_b(struct device *cpu_dev,
122 					  int *speed, int *pvs, int *pvs_ver,
123 					  u8 *buf)
124 {
125 	u32 pte_efuse, redundant_sel;
126 
127 	pte_efuse = *((u32 *)buf);
128 	redundant_sel = (pte_efuse >> 24) & 0x7;
129 
130 	*pvs_ver = (pte_efuse >> 4) & 0x3;
131 
132 	switch (redundant_sel) {
133 	case 1:
134 		*pvs = ((pte_efuse >> 28) & 0x8) | ((pte_efuse >> 6) & 0x7);
135 		*speed = (pte_efuse >> 27) & 0xf;
136 		break;
137 	case 2:
138 		*pvs = (pte_efuse >> 27) & 0xf;
139 		*speed = pte_efuse & 0x7;
140 		break;
141 	default:
142 		/* 4 bits of PVS are in efuse register bits 31, 8-6. */
143 		*pvs = ((pte_efuse >> 28) & 0x8) | ((pte_efuse >> 6) & 0x7);
144 		*speed = pte_efuse & 0x7;
145 	}
146 
147 	/* Check SPEED_BIN_BLOW_STATUS */
148 	if (pte_efuse & BIT(3)) {
149 		dev_dbg(cpu_dev, "Speed bin: %d\n", *speed);
150 	} else {
151 		dev_warn(cpu_dev, "Speed bin not set. Defaulting to 0!\n");
152 		*speed = 0;
153 	}
154 
155 	/* Check PVS_BLOW_STATUS */
156 	pte_efuse = *(((u32 *)buf) + 1);
157 	pte_efuse &= BIT(21);
158 	if (pte_efuse) {
159 		dev_dbg(cpu_dev, "PVS bin: %d\n", *pvs);
160 	} else {
161 		dev_warn(cpu_dev, "PVS bin not set. Defaulting to 0!\n");
162 		*pvs = 0;
163 	}
164 
165 	dev_dbg(cpu_dev, "PVS version: %d\n", *pvs_ver);
166 }
167 
168 static int qcom_cpufreq_kryo_name_version(struct device *cpu_dev,
169 					  struct nvmem_cell *speedbin_nvmem,
170 					  char **pvs_name,
171 					  struct qcom_cpufreq_drv *drv)
172 {
173 	size_t len;
174 	u32 msm_id;
175 	u8 *speedbin;
176 	int ret;
177 	*pvs_name = NULL;
178 
179 	ret = qcom_smem_get_soc_id(&msm_id);
180 	if (ret)
181 		return ret;
182 
183 	speedbin = nvmem_cell_read(speedbin_nvmem, &len);
184 	if (IS_ERR(speedbin))
185 		return PTR_ERR(speedbin);
186 
187 	switch (msm_id) {
188 	case QCOM_ID_MSM8996:
189 	case QCOM_ID_APQ8096:
190 	case QCOM_ID_IPQ5332:
191 	case QCOM_ID_IPQ5322:
192 	case QCOM_ID_IPQ5312:
193 	case QCOM_ID_IPQ5302:
194 	case QCOM_ID_IPQ5300:
195 	case QCOM_ID_IPQ5321:
196 	case QCOM_ID_IPQ9514:
197 	case QCOM_ID_IPQ9550:
198 	case QCOM_ID_IPQ9554:
199 	case QCOM_ID_IPQ9570:
200 	case QCOM_ID_IPQ9574:
201 		drv->versions = 1 << (unsigned int)(*speedbin);
202 		break;
203 	case QCOM_ID_IPQ5424:
204 	case QCOM_ID_IPQ5404:
205 		drv->versions = (*speedbin == 0x3b) ? BIT(1) : BIT(0);
206 		break;
207 	case QCOM_ID_MSM8996SG:
208 	case QCOM_ID_APQ8096SG:
209 		drv->versions = 1 << ((unsigned int)(*speedbin) + 4);
210 		break;
211 	default:
212 		BUG();
213 		break;
214 	}
215 
216 	kfree(speedbin);
217 	return 0;
218 }
219 
220 static int qcom_cpufreq_krait_name_version(struct device *cpu_dev,
221 					   struct nvmem_cell *speedbin_nvmem,
222 					   char **pvs_name,
223 					   struct qcom_cpufreq_drv *drv)
224 {
225 	int speed = 0, pvs = 0, pvs_ver = 0;
226 	u8 *speedbin;
227 	size_t len;
228 	int ret = 0;
229 
230 	speedbin = nvmem_cell_read(speedbin_nvmem, &len);
231 
232 	if (IS_ERR(speedbin))
233 		return PTR_ERR(speedbin);
234 
235 	switch (len) {
236 	case 4:
237 		get_krait_bin_format_a(cpu_dev, &speed, &pvs, speedbin);
238 		break;
239 	case 8:
240 		get_krait_bin_format_b(cpu_dev, &speed, &pvs, &pvs_ver,
241 				       speedbin);
242 		break;
243 	default:
244 		dev_err(cpu_dev, "Unable to read nvmem data. Defaulting to 0!\n");
245 		ret = -ENODEV;
246 		goto len_error;
247 	}
248 
249 	snprintf(*pvs_name, sizeof("speedXX-pvsXX-vXX"), "speed%d-pvs%d-v%d",
250 		 speed, pvs, pvs_ver);
251 
252 	drv->versions = (1 << speed);
253 
254 len_error:
255 	kfree(speedbin);
256 	return ret;
257 }
258 
259 static int qcom_cpufreq_ipq8064_name_version(struct device *cpu_dev,
260 					     struct nvmem_cell *speedbin_nvmem,
261 					     char **pvs_name,
262 					     struct qcom_cpufreq_drv *drv)
263 {
264 	int speed = 0, pvs = 0;
265 	int msm_id, ret = 0;
266 	u8 *speedbin;
267 	size_t len;
268 
269 	speedbin = nvmem_cell_read(speedbin_nvmem, &len);
270 	if (IS_ERR(speedbin))
271 		return PTR_ERR(speedbin);
272 
273 	if (len != 4) {
274 		dev_err(cpu_dev, "Unable to read nvmem data. Defaulting to 0!\n");
275 		ret = -ENODEV;
276 		goto exit;
277 	}
278 
279 	get_krait_bin_format_a(cpu_dev, &speed, &pvs, speedbin);
280 
281 	ret = qcom_smem_get_soc_id(&msm_id);
282 	if (ret)
283 		goto exit;
284 
285 	switch (msm_id) {
286 	case QCOM_ID_IPQ8062:
287 		drv->versions = BIT(IPQ8062_VERSION);
288 		break;
289 	case QCOM_ID_IPQ8064:
290 	case QCOM_ID_IPQ8066:
291 	case QCOM_ID_IPQ8068:
292 		drv->versions = BIT(IPQ8064_VERSION);
293 		break;
294 	case QCOM_ID_IPQ8065:
295 	case QCOM_ID_IPQ8069:
296 		drv->versions = BIT(IPQ8065_VERSION);
297 		break;
298 	default:
299 		dev_err(cpu_dev,
300 			"SoC ID %u is not part of IPQ8064 family, limiting to 1.0GHz!\n",
301 			msm_id);
302 		drv->versions = BIT(IPQ8062_VERSION);
303 		break;
304 	}
305 
306 	/* IPQ8064 speed is never fused. Only pvs values are fused. */
307 	snprintf(*pvs_name, sizeof("speed0-pvsXX"), "speed0-pvs%d", pvs);
308 
309 exit:
310 	kfree(speedbin);
311 	return ret;
312 }
313 
314 static int qcom_cpufreq_ipq6018_name_version(struct device *cpu_dev,
315 					     struct nvmem_cell *speedbin_nvmem,
316 					     char **pvs_name,
317 					     struct qcom_cpufreq_drv *drv)
318 {
319 	u32 msm_id;
320 	int ret;
321 	u8 *speedbin;
322 	*pvs_name = NULL;
323 
324 	ret = qcom_smem_get_soc_id(&msm_id);
325 	if (ret)
326 		return ret;
327 
328 	speedbin = nvmem_cell_read(speedbin_nvmem, NULL);
329 	if (IS_ERR(speedbin))
330 		return PTR_ERR(speedbin);
331 
332 	switch (msm_id) {
333 	case QCOM_ID_IPQ6005:
334 	case QCOM_ID_IPQ6010:
335 	case QCOM_ID_IPQ6018:
336 	case QCOM_ID_IPQ6028:
337 		/* Fuse Value    Freq    BIT to set
338 		 * ---------------------------------
339 		 *   2’b0     No Limit     BIT(0)
340 		 *   2’b1     1.5 GHz      BIT(1)
341 		 */
342 		drv->versions = 1 << (unsigned int)(*speedbin);
343 		break;
344 	case QCOM_ID_IPQ6000:
345 		/*
346 		 * IPQ6018 family only has one bit to advertise the CPU
347 		 * speed-bin, but that is not enough for IPQ6000 which
348 		 * is only rated up to 1.2GHz.
349 		 * So for IPQ6000 manually set BIT(2) based on SMEM ID.
350 		 */
351 		drv->versions = IPQ6000_VERSION;
352 		break;
353 	default:
354 		dev_err(cpu_dev,
355 			"SoC ID %u is not part of IPQ6018 family, limiting to 1.2GHz!\n",
356 			msm_id);
357 		drv->versions = IPQ6000_VERSION;
358 		break;
359 	}
360 
361 	kfree(speedbin);
362 	return 0;
363 }
364 
365 static int qcom_cpufreq_ipq8074_name_version(struct device *cpu_dev,
366 					     struct nvmem_cell *speedbin_nvmem,
367 					     char **pvs_name,
368 					     struct qcom_cpufreq_drv *drv)
369 {
370 	u32 msm_id;
371 	int ret;
372 	*pvs_name = NULL;
373 
374 	ret = qcom_smem_get_soc_id(&msm_id);
375 	if (ret)
376 		return ret;
377 
378 	switch (msm_id) {
379 	case QCOM_ID_IPQ8070A:
380 	case QCOM_ID_IPQ8071A:
381 	case QCOM_ID_IPQ8172:
382 	case QCOM_ID_IPQ8173:
383 	case QCOM_ID_IPQ8174:
384 		drv->versions = BIT(IPQ8074_ACORN_VERSION);
385 		break;
386 	case QCOM_ID_IPQ8072A:
387 	case QCOM_ID_IPQ8074A:
388 	case QCOM_ID_IPQ8076A:
389 	case QCOM_ID_IPQ8078A:
390 		drv->versions = BIT(IPQ8074_HAWKEYE_VERSION);
391 		break;
392 	default:
393 		dev_err(cpu_dev,
394 			"SoC ID %u is not part of IPQ8074 family, limiting to 1.4GHz!\n",
395 			msm_id);
396 		drv->versions = BIT(IPQ8074_ACORN_VERSION);
397 		break;
398 	}
399 
400 	return 0;
401 }
402 
403 static const struct qcom_cpufreq_match_data match_data_kryo = {
404 	.get_version = qcom_cpufreq_kryo_name_version,
405 };
406 
407 static const struct qcom_cpufreq_match_data match_data_krait = {
408 	.get_version = qcom_cpufreq_krait_name_version,
409 };
410 
411 static const struct qcom_cpufreq_match_data match_data_msm8909 = {
412 	.get_version = qcom_cpufreq_simple_get_version,
413 	.pd_names = (const char *[]) { "perf" },
414 	.num_pd_names = 1,
415 };
416 
417 static const struct qcom_cpufreq_match_data match_data_qcs404 = {
418 	.pd_names = (const char *[]) { "cpr" },
419 	.num_pd_names = 1,
420 };
421 
422 static const struct qcom_cpufreq_match_data match_data_ipq6018 = {
423 	.get_version = qcom_cpufreq_ipq6018_name_version,
424 };
425 
426 static const struct qcom_cpufreq_match_data match_data_ipq8064 = {
427 	.get_version = qcom_cpufreq_ipq8064_name_version,
428 };
429 
430 static const struct qcom_cpufreq_match_data match_data_ipq8074 = {
431 	.get_version = qcom_cpufreq_ipq8074_name_version,
432 };
433 
434 static void qcom_cpufreq_suspend_pd_devs(struct qcom_cpufreq_drv *drv, unsigned int cpu)
435 {
436 	struct dev_pm_domain_list *pd_list = drv->cpus[cpu].pd_list;
437 	int i;
438 
439 	if (!pd_list)
440 		return;
441 
442 	for (i = 0; i < pd_list->num_pds; i++)
443 		device_set_awake_path(pd_list->pd_devs[i]);
444 }
445 
446 static int qcom_cpufreq_probe(struct platform_device *pdev)
447 {
448 	struct qcom_cpufreq_drv *drv;
449 	struct nvmem_cell *speedbin_nvmem;
450 	struct device *cpu_dev;
451 	char pvs_name_buffer[] = "speedXX-pvsXX-vXX";
452 	char *pvs_name = pvs_name_buffer;
453 	unsigned cpu;
454 	const struct of_device_id *match;
455 	int ret;
456 
457 	cpu_dev = get_cpu_device(0);
458 	if (!cpu_dev)
459 		return -ENODEV;
460 
461 	struct device_node *np __free(device_node) =
462 		dev_pm_opp_of_get_opp_desc_node(cpu_dev);
463 	if (!np)
464 		return -ENOENT;
465 
466 	ret = of_device_is_compatible(np, "operating-points-v2-kryo-cpu") ||
467 	      of_device_is_compatible(np, "operating-points-v2-krait-cpu");
468 	if (!ret)
469 		return -ENOENT;
470 
471 	drv = devm_kzalloc(&pdev->dev, struct_size(drv, cpus, num_possible_cpus()),
472 		           GFP_KERNEL);
473 	if (!drv)
474 		return -ENOMEM;
475 
476 	match = pdev->dev.platform_data;
477 	drv->data = match->data;
478 	if (!drv->data)
479 		return -ENODEV;
480 
481 	if (drv->data->get_version) {
482 		speedbin_nvmem = of_nvmem_cell_get(np, NULL);
483 		if (IS_ERR(speedbin_nvmem))
484 			return dev_err_probe(cpu_dev, PTR_ERR(speedbin_nvmem),
485 					     "Could not get nvmem cell\n");
486 
487 		ret = drv->data->get_version(cpu_dev,
488 							speedbin_nvmem, &pvs_name, drv);
489 		if (ret) {
490 			nvmem_cell_put(speedbin_nvmem);
491 			return ret;
492 		}
493 		nvmem_cell_put(speedbin_nvmem);
494 	}
495 
496 	for_each_present_cpu(cpu) {
497 		struct dev_pm_opp_config config = {
498 			.supported_hw = NULL,
499 		};
500 
501 		cpu_dev = get_cpu_device(cpu);
502 		if (NULL == cpu_dev) {
503 			ret = -ENODEV;
504 			goto free_opp;
505 		}
506 
507 		if (drv->data->get_version) {
508 			config.supported_hw = &drv->versions;
509 			config.supported_hw_count = 1;
510 
511 			if (pvs_name)
512 				config.prop_name = pvs_name;
513 		}
514 
515 		if (config.supported_hw) {
516 			drv->cpus[cpu].opp_token = dev_pm_opp_set_config(cpu_dev, &config);
517 			if (drv->cpus[cpu].opp_token < 0) {
518 				ret = drv->cpus[cpu].opp_token;
519 				dev_err(cpu_dev, "Failed to set OPP config\n");
520 				goto free_opp;
521 			}
522 		}
523 
524 		if (drv->data->pd_names) {
525 			struct dev_pm_domain_attach_data attach_data = {
526 				.pd_names = drv->data->pd_names,
527 				.num_pd_names = drv->data->num_pd_names,
528 				.pd_flags = PD_FLAG_DEV_LINK_ON |
529 					    PD_FLAG_REQUIRED_OPP,
530 			};
531 
532 			ret = dev_pm_domain_attach_list(cpu_dev, &attach_data,
533 							&drv->cpus[cpu].pd_list);
534 			if (ret < 0)
535 				goto free_opp;
536 		}
537 	}
538 
539 	cpufreq_dt_pdev = platform_device_register_simple("cpufreq-dt", -1,
540 							  NULL, 0);
541 	if (!IS_ERR(cpufreq_dt_pdev)) {
542 		platform_set_drvdata(pdev, drv);
543 		return 0;
544 	}
545 
546 	ret = PTR_ERR(cpufreq_dt_pdev);
547 	dev_err(cpu_dev, "Failed to register platform device\n");
548 
549 free_opp:
550 	for_each_present_cpu(cpu) {
551 		dev_pm_domain_detach_list(drv->cpus[cpu].pd_list);
552 		dev_pm_opp_clear_config(drv->cpus[cpu].opp_token);
553 	}
554 	return ret;
555 }
556 
557 static void qcom_cpufreq_remove(struct platform_device *pdev)
558 {
559 	struct qcom_cpufreq_drv *drv = platform_get_drvdata(pdev);
560 	unsigned int cpu;
561 
562 	platform_device_unregister(cpufreq_dt_pdev);
563 
564 	for_each_present_cpu(cpu) {
565 		dev_pm_domain_detach_list(drv->cpus[cpu].pd_list);
566 		dev_pm_opp_clear_config(drv->cpus[cpu].opp_token);
567 	}
568 }
569 
570 static int qcom_cpufreq_suspend(struct device *dev)
571 {
572 	struct qcom_cpufreq_drv *drv = dev_get_drvdata(dev);
573 	unsigned int cpu;
574 
575 	for_each_present_cpu(cpu)
576 		qcom_cpufreq_suspend_pd_devs(drv, cpu);
577 
578 	return 0;
579 }
580 
581 static DEFINE_SIMPLE_DEV_PM_OPS(qcom_cpufreq_pm_ops, qcom_cpufreq_suspend, NULL);
582 
583 static struct platform_driver qcom_cpufreq_driver = {
584 	.probe = qcom_cpufreq_probe,
585 	.remove = qcom_cpufreq_remove,
586 	.driver = {
587 		.name = "qcom-cpufreq-nvmem",
588 		.pm = pm_sleep_ptr(&qcom_cpufreq_pm_ops),
589 	},
590 };
591 
592 static const struct of_device_id qcom_cpufreq_match_list[] __initconst __maybe_unused = {
593 	{ .compatible = "qcom,apq8096", .data = &match_data_kryo },
594 	{ .compatible = "qcom,msm8909", .data = &match_data_msm8909 },
595 	{ .compatible = "qcom,msm8996", .data = &match_data_kryo },
596 	{ .compatible = "qcom,qcs404", .data = &match_data_qcs404 },
597 	{ .compatible = "qcom,ipq5332", .data = &match_data_kryo },
598 	{ .compatible = "qcom,ipq5424", .data = &match_data_kryo },
599 	{ .compatible = "qcom,ipq6018", .data = &match_data_ipq6018 },
600 	{ .compatible = "qcom,ipq8064", .data = &match_data_ipq8064 },
601 	{ .compatible = "qcom,ipq8074", .data = &match_data_ipq8074 },
602 	{ .compatible = "qcom,apq8064", .data = &match_data_krait },
603 	{ .compatible = "qcom,ipq9574", .data = &match_data_kryo },
604 	{ .compatible = "qcom,msm8974", .data = &match_data_krait },
605 	{ .compatible = "qcom,msm8960", .data = &match_data_krait },
606 	{},
607 };
608 MODULE_DEVICE_TABLE(of, qcom_cpufreq_match_list);
609 
610 /*
611  * Since the driver depends on smem and nvmem drivers, which may
612  * return EPROBE_DEFER, all the real activity is done in the probe,
613  * which may be defered as well. The init here is only registering
614  * the driver and the platform device.
615  */
616 static int __init qcom_cpufreq_init(void)
617 {
618 	struct device_node *np __free(device_node) = of_find_node_by_path("/");
619 	const struct of_device_id *match;
620 	int ret;
621 
622 	if (!np)
623 		return -ENODEV;
624 
625 	match = of_match_node(qcom_cpufreq_match_list, np);
626 	if (!match)
627 		return -ENODEV;
628 
629 	ret = platform_driver_register(&qcom_cpufreq_driver);
630 	if (unlikely(ret < 0))
631 		return ret;
632 
633 	cpufreq_pdev = platform_device_register_data(NULL, "qcom-cpufreq-nvmem",
634 						     -1, match, sizeof(*match));
635 	ret = PTR_ERR_OR_ZERO(cpufreq_pdev);
636 	if (0 == ret)
637 		return 0;
638 
639 	platform_driver_unregister(&qcom_cpufreq_driver);
640 	return ret;
641 }
642 module_init(qcom_cpufreq_init);
643 
644 static void __exit qcom_cpufreq_exit(void)
645 {
646 	platform_device_unregister(cpufreq_pdev);
647 	platform_driver_unregister(&qcom_cpufreq_driver);
648 }
649 module_exit(qcom_cpufreq_exit);
650 
651 MODULE_DESCRIPTION("Qualcomm Technologies, Inc. CPUfreq driver");
652 MODULE_LICENSE("GPL v2");
653