1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * exynos_ppmu.c - Exynos PPMU (Platform Performance Monitoring Unit) support
4  *
5  * Copyright (c) 2014-2015 Samsung Electronics Co., Ltd.
6  * Author : Chanwoo Choi <cw00.choi@samsung.com>
7  *
8  * This driver is based on drivers/devfreq/exynos/exynos_ppmu.c
9  */
10 
11 #include <linux/clk.h>
12 #include <linux/io.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/of_address.h>
16 #include <linux/of_device.h>
17 #include <linux/platform_device.h>
18 #include <linux/regmap.h>
19 #include <linux/suspend.h>
20 #include <linux/devfreq-event.h>
21 
22 #include "exynos-ppmu.h"
23 
24 enum exynos_ppmu_type {
25 	EXYNOS_TYPE_PPMU,
26 	EXYNOS_TYPE_PPMU_V2,
27 };
28 
29 struct exynos_ppmu_data {
30 	struct clk *clk;
31 };
32 
33 struct exynos_ppmu {
34 	struct devfreq_event_dev **edev;
35 	struct devfreq_event_desc *desc;
36 	unsigned int num_events;
37 
38 	struct device *dev;
39 	struct regmap *regmap;
40 
41 	struct exynos_ppmu_data ppmu;
42 	enum exynos_ppmu_type ppmu_type;
43 };
44 
45 #define PPMU_EVENT(name)			\
46 	{ "ppmu-event0-"#name, PPMU_PMNCNT0 },	\
47 	{ "ppmu-event1-"#name, PPMU_PMNCNT1 },	\
48 	{ "ppmu-event2-"#name, PPMU_PMNCNT2 },	\
49 	{ "ppmu-event3-"#name, PPMU_PMNCNT3 }
50 
51 static struct __exynos_ppmu_events {
52 	char *name;
53 	int id;
54 } ppmu_events[] = {
55 	/* For Exynos3250, Exynos4 and Exynos5260 */
56 	PPMU_EVENT(g3d),
57 	PPMU_EVENT(fsys),
58 
59 	/* For Exynos4 SoCs and Exynos3250 */
60 	PPMU_EVENT(dmc0),
61 	PPMU_EVENT(dmc1),
62 	PPMU_EVENT(cpu),
63 	PPMU_EVENT(rightbus),
64 	PPMU_EVENT(leftbus),
65 	PPMU_EVENT(lcd0),
66 	PPMU_EVENT(camif),
67 
68 	/* Only for Exynos3250 and Exynos5260 */
69 	PPMU_EVENT(mfc),
70 
71 	/* Only for Exynos4 SoCs */
72 	PPMU_EVENT(mfc-left),
73 	PPMU_EVENT(mfc-right),
74 
75 	/* Only for Exynos5260 SoCs */
76 	PPMU_EVENT(drex0-s0),
77 	PPMU_EVENT(drex0-s1),
78 	PPMU_EVENT(drex1-s0),
79 	PPMU_EVENT(drex1-s1),
80 	PPMU_EVENT(eagle),
81 	PPMU_EVENT(kfc),
82 	PPMU_EVENT(isp),
83 	PPMU_EVENT(fimc),
84 	PPMU_EVENT(gscl),
85 	PPMU_EVENT(mscl),
86 	PPMU_EVENT(fimd0x),
87 	PPMU_EVENT(fimd1x),
88 
89 	/* Only for Exynos5433 SoCs */
90 	PPMU_EVENT(d0-cpu),
91 	PPMU_EVENT(d0-general),
92 	PPMU_EVENT(d0-rt),
93 	PPMU_EVENT(d1-cpu),
94 	PPMU_EVENT(d1-general),
95 	PPMU_EVENT(d1-rt),
96 
97 	/* For Exynos5422 SoC, deprecated (backwards compatible) */
98 	PPMU_EVENT(dmc0_0),
99 	PPMU_EVENT(dmc0_1),
100 	PPMU_EVENT(dmc1_0),
101 	PPMU_EVENT(dmc1_1),
102 	/* For Exynos5422 SoC */
103 	PPMU_EVENT(dmc0-0),
104 	PPMU_EVENT(dmc0-1),
105 	PPMU_EVENT(dmc1-0),
106 	PPMU_EVENT(dmc1-1),
107 };
108 
109 static int __exynos_ppmu_find_ppmu_id(const char *edev_name)
110 {
111 	int i;
112 
113 	for (i = 0; i < ARRAY_SIZE(ppmu_events); i++)
114 		if (!strcmp(edev_name, ppmu_events[i].name))
115 			return ppmu_events[i].id;
116 
117 	return -EINVAL;
118 }
119 
120 static int exynos_ppmu_find_ppmu_id(struct devfreq_event_dev *edev)
121 {
122 	return __exynos_ppmu_find_ppmu_id(edev->desc->name);
123 }
124 
125 /*
126  * The devfreq-event ops structure for PPMU v1.1
127  */
128 static int exynos_ppmu_disable(struct devfreq_event_dev *edev)
129 {
130 	struct exynos_ppmu *info = devfreq_event_get_drvdata(edev);
131 	int ret;
132 	u32 pmnc;
133 
134 	/* Disable all counters */
135 	ret = regmap_write(info->regmap, PPMU_CNTENC,
136 				PPMU_CCNT_MASK |
137 				PPMU_PMCNT0_MASK |
138 				PPMU_PMCNT1_MASK |
139 				PPMU_PMCNT2_MASK |
140 				PPMU_PMCNT3_MASK);
141 	if (ret < 0)
142 		return ret;
143 
144 	/* Disable PPMU */
145 	ret = regmap_read(info->regmap, PPMU_PMNC, &pmnc);
146 	if (ret < 0)
147 		return ret;
148 
149 	pmnc &= ~PPMU_PMNC_ENABLE_MASK;
150 	ret = regmap_write(info->regmap, PPMU_PMNC, pmnc);
151 	if (ret < 0)
152 		return ret;
153 
154 	return 0;
155 }
156 
157 static int exynos_ppmu_set_event(struct devfreq_event_dev *edev)
158 {
159 	struct exynos_ppmu *info = devfreq_event_get_drvdata(edev);
160 	int id = exynos_ppmu_find_ppmu_id(edev);
161 	int ret;
162 	u32 pmnc, cntens;
163 
164 	if (id < 0)
165 		return id;
166 
167 	/* Enable specific counter */
168 	ret = regmap_read(info->regmap, PPMU_CNTENS, &cntens);
169 	if (ret < 0)
170 		return ret;
171 
172 	cntens |= (PPMU_CCNT_MASK | (PPMU_ENABLE << id));
173 	ret = regmap_write(info->regmap, PPMU_CNTENS, cntens);
174 	if (ret < 0)
175 		return ret;
176 
177 	/* Set the event of proper data type monitoring */
178 	ret = regmap_write(info->regmap, PPMU_BEVTxSEL(id),
179 			   edev->desc->event_type);
180 	if (ret < 0)
181 		return ret;
182 
183 	/* Reset cycle counter/performance counter and enable PPMU */
184 	ret = regmap_read(info->regmap, PPMU_PMNC, &pmnc);
185 	if (ret < 0)
186 		return ret;
187 
188 	pmnc &= ~(PPMU_PMNC_ENABLE_MASK
189 			| PPMU_PMNC_COUNTER_RESET_MASK
190 			| PPMU_PMNC_CC_RESET_MASK);
191 	pmnc |= (PPMU_ENABLE << PPMU_PMNC_ENABLE_SHIFT);
192 	pmnc |= (PPMU_ENABLE << PPMU_PMNC_COUNTER_RESET_SHIFT);
193 	pmnc |= (PPMU_ENABLE << PPMU_PMNC_CC_RESET_SHIFT);
194 	ret = regmap_write(info->regmap, PPMU_PMNC, pmnc);
195 	if (ret < 0)
196 		return ret;
197 
198 	return 0;
199 }
200 
201 static int exynos_ppmu_get_event(struct devfreq_event_dev *edev,
202 				struct devfreq_event_data *edata)
203 {
204 	struct exynos_ppmu *info = devfreq_event_get_drvdata(edev);
205 	int id = exynos_ppmu_find_ppmu_id(edev);
206 	unsigned int total_count, load_count;
207 	unsigned int pmcnt3_high, pmcnt3_low;
208 	unsigned int pmnc, cntenc;
209 	int ret;
210 
211 	if (id < 0)
212 		return -EINVAL;
213 
214 	/* Disable PPMU */
215 	ret = regmap_read(info->regmap, PPMU_PMNC, &pmnc);
216 	if (ret < 0)
217 		return ret;
218 
219 	pmnc &= ~PPMU_PMNC_ENABLE_MASK;
220 	ret = regmap_write(info->regmap, PPMU_PMNC, pmnc);
221 	if (ret < 0)
222 		return ret;
223 
224 	/* Read cycle count */
225 	ret = regmap_read(info->regmap, PPMU_CCNT, &total_count);
226 	if (ret < 0)
227 		return ret;
228 	edata->total_count = total_count;
229 
230 	/* Read performance count */
231 	switch (id) {
232 	case PPMU_PMNCNT0:
233 	case PPMU_PMNCNT1:
234 	case PPMU_PMNCNT2:
235 		ret = regmap_read(info->regmap, PPMU_PMNCT(id), &load_count);
236 		if (ret < 0)
237 			return ret;
238 		edata->load_count = load_count;
239 		break;
240 	case PPMU_PMNCNT3:
241 		ret = regmap_read(info->regmap, PPMU_PMCNT3_HIGH, &pmcnt3_high);
242 		if (ret < 0)
243 			return ret;
244 
245 		ret = regmap_read(info->regmap, PPMU_PMCNT3_LOW, &pmcnt3_low);
246 		if (ret < 0)
247 			return ret;
248 
249 		edata->load_count = ((pmcnt3_high << 8) | pmcnt3_low);
250 		break;
251 	default:
252 		return -EINVAL;
253 	}
254 
255 	/* Disable specific counter */
256 	ret = regmap_read(info->regmap, PPMU_CNTENC, &cntenc);
257 	if (ret < 0)
258 		return ret;
259 
260 	cntenc |= (PPMU_CCNT_MASK | (PPMU_ENABLE << id));
261 	ret = regmap_write(info->regmap, PPMU_CNTENC, cntenc);
262 	if (ret < 0)
263 		return ret;
264 
265 	dev_dbg(&edev->dev, "%s (event: %ld/%ld)\n", edev->desc->name,
266 					edata->load_count, edata->total_count);
267 
268 	return 0;
269 }
270 
271 static const struct devfreq_event_ops exynos_ppmu_ops = {
272 	.disable = exynos_ppmu_disable,
273 	.set_event = exynos_ppmu_set_event,
274 	.get_event = exynos_ppmu_get_event,
275 };
276 
277 /*
278  * The devfreq-event ops structure for PPMU v2.0
279  */
280 static int exynos_ppmu_v2_disable(struct devfreq_event_dev *edev)
281 {
282 	struct exynos_ppmu *info = devfreq_event_get_drvdata(edev);
283 	int ret;
284 	u32 pmnc, clear;
285 
286 	/* Disable all counters */
287 	clear = (PPMU_CCNT_MASK | PPMU_PMCNT0_MASK | PPMU_PMCNT1_MASK
288 		| PPMU_PMCNT2_MASK | PPMU_PMCNT3_MASK);
289 	ret = regmap_write(info->regmap, PPMU_V2_FLAG, clear);
290 	if (ret < 0)
291 		return ret;
292 
293 	ret = regmap_write(info->regmap, PPMU_V2_INTENC, clear);
294 	if (ret < 0)
295 		return ret;
296 
297 	ret = regmap_write(info->regmap, PPMU_V2_CNTENC, clear);
298 	if (ret < 0)
299 		return ret;
300 
301 	ret = regmap_write(info->regmap, PPMU_V2_CNT_RESET, clear);
302 	if (ret < 0)
303 		return ret;
304 
305 	ret = regmap_write(info->regmap, PPMU_V2_CIG_CFG0, 0x0);
306 	if (ret < 0)
307 		return ret;
308 
309 	ret = regmap_write(info->regmap, PPMU_V2_CIG_CFG1, 0x0);
310 	if (ret < 0)
311 		return ret;
312 
313 	ret = regmap_write(info->regmap, PPMU_V2_CIG_CFG2, 0x0);
314 	if (ret < 0)
315 		return ret;
316 
317 	ret = regmap_write(info->regmap, PPMU_V2_CIG_RESULT, 0x0);
318 	if (ret < 0)
319 		return ret;
320 
321 	ret = regmap_write(info->regmap, PPMU_V2_CNT_AUTO, 0x0);
322 	if (ret < 0)
323 		return ret;
324 
325 	ret = regmap_write(info->regmap, PPMU_V2_CH_EV0_TYPE, 0x0);
326 	if (ret < 0)
327 		return ret;
328 
329 	ret = regmap_write(info->regmap, PPMU_V2_CH_EV1_TYPE, 0x0);
330 	if (ret < 0)
331 		return ret;
332 
333 	ret = regmap_write(info->regmap, PPMU_V2_CH_EV2_TYPE, 0x0);
334 	if (ret < 0)
335 		return ret;
336 
337 	ret = regmap_write(info->regmap, PPMU_V2_CH_EV3_TYPE, 0x0);
338 	if (ret < 0)
339 		return ret;
340 
341 	ret = regmap_write(info->regmap, PPMU_V2_SM_ID_V, 0x0);
342 	if (ret < 0)
343 		return ret;
344 
345 	ret = regmap_write(info->regmap, PPMU_V2_SM_ID_A, 0x0);
346 	if (ret < 0)
347 		return ret;
348 
349 	ret = regmap_write(info->regmap, PPMU_V2_SM_OTHERS_V, 0x0);
350 	if (ret < 0)
351 		return ret;
352 
353 	ret = regmap_write(info->regmap, PPMU_V2_SM_OTHERS_A, 0x0);
354 	if (ret < 0)
355 		return ret;
356 
357 	ret = regmap_write(info->regmap, PPMU_V2_INTERRUPT_RESET, 0x0);
358 	if (ret < 0)
359 		return ret;
360 
361 	/* Disable PPMU */
362 	ret = regmap_read(info->regmap, PPMU_V2_PMNC, &pmnc);
363 	if (ret < 0)
364 		return ret;
365 
366 	pmnc &= ~PPMU_PMNC_ENABLE_MASK;
367 	ret = regmap_write(info->regmap, PPMU_V2_PMNC, pmnc);
368 	if (ret < 0)
369 		return ret;
370 
371 	return 0;
372 }
373 
374 static int exynos_ppmu_v2_set_event(struct devfreq_event_dev *edev)
375 {
376 	struct exynos_ppmu *info = devfreq_event_get_drvdata(edev);
377 	unsigned int pmnc, cntens;
378 	int id = exynos_ppmu_find_ppmu_id(edev);
379 	int ret;
380 
381 	/* Enable all counters */
382 	ret = regmap_read(info->regmap, PPMU_V2_CNTENS, &cntens);
383 	if (ret < 0)
384 		return ret;
385 
386 	cntens |= (PPMU_CCNT_MASK | (PPMU_ENABLE << id));
387 	ret = regmap_write(info->regmap, PPMU_V2_CNTENS, cntens);
388 	if (ret < 0)
389 		return ret;
390 
391 	/* Set the event of proper data type monitoring */
392 	ret = regmap_write(info->regmap, PPMU_V2_CH_EVx_TYPE(id),
393 			   edev->desc->event_type);
394 	if (ret < 0)
395 		return ret;
396 
397 	/* Reset cycle counter/performance counter and enable PPMU */
398 	ret = regmap_read(info->regmap, PPMU_V2_PMNC, &pmnc);
399 	if (ret < 0)
400 		return ret;
401 
402 	pmnc &= ~(PPMU_PMNC_ENABLE_MASK
403 			| PPMU_PMNC_COUNTER_RESET_MASK
404 			| PPMU_PMNC_CC_RESET_MASK
405 			| PPMU_PMNC_CC_DIVIDER_MASK
406 			| PPMU_V2_PMNC_START_MODE_MASK);
407 	pmnc |= (PPMU_ENABLE << PPMU_PMNC_ENABLE_SHIFT);
408 	pmnc |= (PPMU_ENABLE << PPMU_PMNC_COUNTER_RESET_SHIFT);
409 	pmnc |= (PPMU_ENABLE << PPMU_PMNC_CC_RESET_SHIFT);
410 	pmnc |= (PPMU_V2_MODE_MANUAL << PPMU_V2_PMNC_START_MODE_SHIFT);
411 
412 	ret = regmap_write(info->regmap, PPMU_V2_PMNC, pmnc);
413 	if (ret < 0)
414 		return ret;
415 
416 	return 0;
417 }
418 
419 static int exynos_ppmu_v2_get_event(struct devfreq_event_dev *edev,
420 				    struct devfreq_event_data *edata)
421 {
422 	struct exynos_ppmu *info = devfreq_event_get_drvdata(edev);
423 	int id = exynos_ppmu_find_ppmu_id(edev);
424 	int ret;
425 	unsigned int pmnc, cntenc;
426 	unsigned int pmcnt_high, pmcnt_low;
427 	unsigned int total_count, count;
428 	unsigned long load_count = 0;
429 
430 	/* Disable PPMU */
431 	ret = regmap_read(info->regmap, PPMU_V2_PMNC, &pmnc);
432 	if (ret < 0)
433 		return ret;
434 
435 	pmnc &= ~PPMU_PMNC_ENABLE_MASK;
436 	ret = regmap_write(info->regmap, PPMU_V2_PMNC, pmnc);
437 	if (ret < 0)
438 		return ret;
439 
440 	/* Read cycle count and performance count */
441 	ret = regmap_read(info->regmap, PPMU_V2_CCNT, &total_count);
442 	if (ret < 0)
443 		return ret;
444 	edata->total_count = total_count;
445 
446 	switch (id) {
447 	case PPMU_PMNCNT0:
448 	case PPMU_PMNCNT1:
449 	case PPMU_PMNCNT2:
450 		ret = regmap_read(info->regmap, PPMU_V2_PMNCT(id), &count);
451 		if (ret < 0)
452 			return ret;
453 		load_count = count;
454 		break;
455 	case PPMU_PMNCNT3:
456 		ret = regmap_read(info->regmap, PPMU_V2_PMCNT3_HIGH,
457 						&pmcnt_high);
458 		if (ret < 0)
459 			return ret;
460 
461 		ret = regmap_read(info->regmap, PPMU_V2_PMCNT3_LOW, &pmcnt_low);
462 		if (ret < 0)
463 			return ret;
464 
465 		load_count = ((u64)((pmcnt_high & 0xff)) << 32)+ (u64)pmcnt_low;
466 		break;
467 	}
468 	edata->load_count = load_count;
469 
470 	/* Disable all counters */
471 	ret = regmap_read(info->regmap, PPMU_V2_CNTENC, &cntenc);
472 	if (ret < 0)
473 		return 0;
474 
475 	cntenc |= (PPMU_CCNT_MASK | (PPMU_ENABLE << id));
476 	ret = regmap_write(info->regmap, PPMU_V2_CNTENC, cntenc);
477 	if (ret < 0)
478 		return ret;
479 
480 	dev_dbg(&edev->dev, "%25s (load: %ld / %ld)\n", edev->desc->name,
481 					edata->load_count, edata->total_count);
482 	return 0;
483 }
484 
485 static const struct devfreq_event_ops exynos_ppmu_v2_ops = {
486 	.disable = exynos_ppmu_v2_disable,
487 	.set_event = exynos_ppmu_v2_set_event,
488 	.get_event = exynos_ppmu_v2_get_event,
489 };
490 
491 static const struct of_device_id exynos_ppmu_id_match[] = {
492 	{
493 		.compatible = "samsung,exynos-ppmu",
494 		.data = (void *)EXYNOS_TYPE_PPMU,
495 	}, {
496 		.compatible = "samsung,exynos-ppmu-v2",
497 		.data = (void *)EXYNOS_TYPE_PPMU_V2,
498 	},
499 	{ /* sentinel */ },
500 };
501 MODULE_DEVICE_TABLE(of, exynos_ppmu_id_match);
502 
503 static int of_get_devfreq_events(struct device_node *np,
504 				 struct exynos_ppmu *info)
505 {
506 	struct devfreq_event_desc *desc;
507 	struct device *dev = info->dev;
508 	struct device_node *events_np, *node;
509 	int i, j, count;
510 	const struct of_device_id *of_id;
511 	int ret;
512 
513 	events_np = of_get_child_by_name(np, "events");
514 	if (!events_np) {
515 		dev_err(dev,
516 			"failed to get child node of devfreq-event devices\n");
517 		return -EINVAL;
518 	}
519 
520 	count = of_get_child_count(events_np);
521 	desc = devm_kcalloc(dev, count, sizeof(*desc), GFP_KERNEL);
522 	if (!desc) {
523 		of_node_put(events_np);
524 		return -ENOMEM;
525 	}
526 	info->num_events = count;
527 
528 	of_id = of_match_device(exynos_ppmu_id_match, dev);
529 	if (of_id)
530 		info->ppmu_type = (enum exynos_ppmu_type)of_id->data;
531 	else {
532 		of_node_put(events_np);
533 		return -EINVAL;
534 	}
535 
536 	j = 0;
537 	for_each_child_of_node(events_np, node) {
538 		for (i = 0; i < ARRAY_SIZE(ppmu_events); i++) {
539 			if (!ppmu_events[i].name)
540 				continue;
541 
542 			if (of_node_name_eq(node, ppmu_events[i].name))
543 				break;
544 		}
545 
546 		if (i == ARRAY_SIZE(ppmu_events)) {
547 			dev_warn(dev,
548 				"don't know how to configure events : %pOFn\n",
549 				node);
550 			continue;
551 		}
552 
553 		switch (info->ppmu_type) {
554 		case EXYNOS_TYPE_PPMU:
555 			desc[j].ops = &exynos_ppmu_ops;
556 			break;
557 		case EXYNOS_TYPE_PPMU_V2:
558 			desc[j].ops = &exynos_ppmu_v2_ops;
559 			break;
560 		}
561 
562 		desc[j].driver_data = info;
563 
564 		of_property_read_string(node, "event-name", &desc[j].name);
565 		ret = of_property_read_u32(node, "event-data-type",
566 					   &desc[j].event_type);
567 		if (ret) {
568 			/* Set the event of proper data type counting.
569 			 * Check if the data type has been defined in DT,
570 			 * use default if not.
571 			 */
572 			if (info->ppmu_type == EXYNOS_TYPE_PPMU_V2) {
573 				/* Not all registers take the same value for
574 				 * read+write data count.
575 				 */
576 				switch (ppmu_events[i].id) {
577 				case PPMU_PMNCNT0:
578 				case PPMU_PMNCNT1:
579 				case PPMU_PMNCNT2:
580 					desc[j].event_type = PPMU_V2_RO_DATA_CNT
581 						| PPMU_V2_WO_DATA_CNT;
582 					break;
583 				case PPMU_PMNCNT3:
584 					desc[j].event_type =
585 						PPMU_V2_EVT3_RW_DATA_CNT;
586 					break;
587 				}
588 			} else {
589 				desc[j].event_type = PPMU_RO_DATA_CNT |
590 					PPMU_WO_DATA_CNT;
591 			}
592 		}
593 
594 		j++;
595 	}
596 	info->desc = desc;
597 
598 	of_node_put(events_np);
599 
600 	return 0;
601 }
602 
603 static struct regmap_config exynos_ppmu_regmap_config = {
604 	.reg_bits = 32,
605 	.val_bits = 32,
606 	.reg_stride = 4,
607 };
608 
609 static int exynos_ppmu_parse_dt(struct platform_device *pdev,
610 				struct exynos_ppmu *info)
611 {
612 	struct device *dev = info->dev;
613 	struct device_node *np = dev->of_node;
614 	struct resource *res;
615 	void __iomem *base;
616 	int ret = 0;
617 
618 	if (!np) {
619 		dev_err(dev, "failed to find devicetree node\n");
620 		return -EINVAL;
621 	}
622 
623 	/* Maps the memory mapped IO to control PPMU register */
624 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
625 	base = devm_ioremap_resource(dev, res);
626 	if (IS_ERR(base))
627 		return PTR_ERR(base);
628 
629 	exynos_ppmu_regmap_config.max_register = resource_size(res) - 4;
630 	info->regmap = devm_regmap_init_mmio(dev, base,
631 					&exynos_ppmu_regmap_config);
632 	if (IS_ERR(info->regmap)) {
633 		dev_err(dev, "failed to initialize regmap\n");
634 		return PTR_ERR(info->regmap);
635 	}
636 
637 	info->ppmu.clk = devm_clk_get(dev, "ppmu");
638 	if (IS_ERR(info->ppmu.clk)) {
639 		info->ppmu.clk = NULL;
640 		dev_warn(dev, "cannot get PPMU clock\n");
641 	}
642 
643 	ret = of_get_devfreq_events(np, info);
644 	if (ret < 0) {
645 		dev_err(dev, "failed to parse exynos ppmu dt node\n");
646 		return ret;
647 	}
648 
649 	return 0;
650 }
651 
652 static int exynos_ppmu_probe(struct platform_device *pdev)
653 {
654 	struct exynos_ppmu *info;
655 	struct devfreq_event_dev **edev;
656 	struct devfreq_event_desc *desc;
657 	int i, ret = 0, size;
658 
659 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
660 	if (!info)
661 		return -ENOMEM;
662 
663 	info->dev = &pdev->dev;
664 
665 	/* Parse dt data to get resource */
666 	ret = exynos_ppmu_parse_dt(pdev, info);
667 	if (ret < 0) {
668 		dev_err(&pdev->dev,
669 			"failed to parse devicetree for resource\n");
670 		return ret;
671 	}
672 	desc = info->desc;
673 
674 	size = sizeof(struct devfreq_event_dev *) * info->num_events;
675 	info->edev = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
676 	if (!info->edev)
677 		return -ENOMEM;
678 
679 	edev = info->edev;
680 	platform_set_drvdata(pdev, info);
681 
682 	for (i = 0; i < info->num_events; i++) {
683 		edev[i] = devm_devfreq_event_add_edev(&pdev->dev, &desc[i]);
684 		if (IS_ERR(edev[i])) {
685 			dev_err(&pdev->dev,
686 				"failed to add devfreq-event device\n");
687 			return PTR_ERR(edev[i]);
688 		}
689 
690 		pr_info("exynos-ppmu: new PPMU device registered %s (%s)\n",
691 			dev_name(&pdev->dev), desc[i].name);
692 	}
693 
694 	ret = clk_prepare_enable(info->ppmu.clk);
695 	if (ret) {
696 		dev_err(&pdev->dev, "failed to prepare ppmu clock\n");
697 		return ret;
698 	}
699 
700 	return 0;
701 }
702 
703 static int exynos_ppmu_remove(struct platform_device *pdev)
704 {
705 	struct exynos_ppmu *info = platform_get_drvdata(pdev);
706 
707 	clk_disable_unprepare(info->ppmu.clk);
708 
709 	return 0;
710 }
711 
712 static struct platform_driver exynos_ppmu_driver = {
713 	.probe	= exynos_ppmu_probe,
714 	.remove	= exynos_ppmu_remove,
715 	.driver = {
716 		.name	= "exynos-ppmu",
717 		.of_match_table = exynos_ppmu_id_match,
718 	},
719 };
720 module_platform_driver(exynos_ppmu_driver);
721 
722 MODULE_DESCRIPTION("Exynos PPMU(Platform Performance Monitoring Unit) driver");
723 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
724 MODULE_LICENSE("GPL");
725