xref: /linux/drivers/devfreq/event/exynos-ppmu.c (revision 17cfcb68af3bc7d5e8ae08779b1853310a2949f3)
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 */
98 	PPMU_EVENT(dmc0_0),
99 	PPMU_EVENT(dmc0_1),
100 	PPMU_EVENT(dmc1_0),
101 	PPMU_EVENT(dmc1_1),
102 };
103 
104 static int exynos_ppmu_find_ppmu_id(struct devfreq_event_dev *edev)
105 {
106 	int i;
107 
108 	for (i = 0; i < ARRAY_SIZE(ppmu_events); i++)
109 		if (!strcmp(edev->desc->name, ppmu_events[i].name))
110 			return ppmu_events[i].id;
111 
112 	return -EINVAL;
113 }
114 
115 /*
116  * The devfreq-event ops structure for PPMU v1.1
117  */
118 static int exynos_ppmu_disable(struct devfreq_event_dev *edev)
119 {
120 	struct exynos_ppmu *info = devfreq_event_get_drvdata(edev);
121 	int ret;
122 	u32 pmnc;
123 
124 	/* Disable all counters */
125 	ret = regmap_write(info->regmap, PPMU_CNTENC,
126 				PPMU_CCNT_MASK |
127 				PPMU_PMCNT0_MASK |
128 				PPMU_PMCNT1_MASK |
129 				PPMU_PMCNT2_MASK |
130 				PPMU_PMCNT3_MASK);
131 	if (ret < 0)
132 		return ret;
133 
134 	/* Disable PPMU */
135 	ret = regmap_read(info->regmap, PPMU_PMNC, &pmnc);
136 	if (ret < 0)
137 		return ret;
138 
139 	pmnc &= ~PPMU_PMNC_ENABLE_MASK;
140 	ret = regmap_write(info->regmap, PPMU_PMNC, pmnc);
141 	if (ret < 0)
142 		return ret;
143 
144 	return 0;
145 }
146 
147 static int exynos_ppmu_set_event(struct devfreq_event_dev *edev)
148 {
149 	struct exynos_ppmu *info = devfreq_event_get_drvdata(edev);
150 	int id = exynos_ppmu_find_ppmu_id(edev);
151 	int ret;
152 	u32 pmnc, cntens;
153 
154 	if (id < 0)
155 		return id;
156 
157 	/* Enable specific counter */
158 	ret = regmap_read(info->regmap, PPMU_CNTENS, &cntens);
159 	if (ret < 0)
160 		return ret;
161 
162 	cntens |= (PPMU_CCNT_MASK | (PPMU_ENABLE << id));
163 	ret = regmap_write(info->regmap, PPMU_CNTENS, cntens);
164 	if (ret < 0)
165 		return ret;
166 
167 	/* Set the event of proper data type monitoring */
168 	ret = regmap_write(info->regmap, PPMU_BEVTxSEL(id),
169 			   edev->desc->event_type);
170 	if (ret < 0)
171 		return ret;
172 
173 	/* Reset cycle counter/performance counter and enable PPMU */
174 	ret = regmap_read(info->regmap, PPMU_PMNC, &pmnc);
175 	if (ret < 0)
176 		return ret;
177 
178 	pmnc &= ~(PPMU_PMNC_ENABLE_MASK
179 			| PPMU_PMNC_COUNTER_RESET_MASK
180 			| PPMU_PMNC_CC_RESET_MASK);
181 	pmnc |= (PPMU_ENABLE << PPMU_PMNC_ENABLE_SHIFT);
182 	pmnc |= (PPMU_ENABLE << PPMU_PMNC_COUNTER_RESET_SHIFT);
183 	pmnc |= (PPMU_ENABLE << PPMU_PMNC_CC_RESET_SHIFT);
184 	ret = regmap_write(info->regmap, PPMU_PMNC, pmnc);
185 	if (ret < 0)
186 		return ret;
187 
188 	return 0;
189 }
190 
191 static int exynos_ppmu_get_event(struct devfreq_event_dev *edev,
192 				struct devfreq_event_data *edata)
193 {
194 	struct exynos_ppmu *info = devfreq_event_get_drvdata(edev);
195 	int id = exynos_ppmu_find_ppmu_id(edev);
196 	unsigned int total_count, load_count;
197 	unsigned int pmcnt3_high, pmcnt3_low;
198 	unsigned int pmnc, cntenc;
199 	int ret;
200 
201 	if (id < 0)
202 		return -EINVAL;
203 
204 	/* Disable PPMU */
205 	ret = regmap_read(info->regmap, PPMU_PMNC, &pmnc);
206 	if (ret < 0)
207 		return ret;
208 
209 	pmnc &= ~PPMU_PMNC_ENABLE_MASK;
210 	ret = regmap_write(info->regmap, PPMU_PMNC, pmnc);
211 	if (ret < 0)
212 		return ret;
213 
214 	/* Read cycle count */
215 	ret = regmap_read(info->regmap, PPMU_CCNT, &total_count);
216 	if (ret < 0)
217 		return ret;
218 	edata->total_count = total_count;
219 
220 	/* Read performance count */
221 	switch (id) {
222 	case PPMU_PMNCNT0:
223 	case PPMU_PMNCNT1:
224 	case PPMU_PMNCNT2:
225 		ret = regmap_read(info->regmap, PPMU_PMNCT(id), &load_count);
226 		if (ret < 0)
227 			return ret;
228 		edata->load_count = load_count;
229 		break;
230 	case PPMU_PMNCNT3:
231 		ret = regmap_read(info->regmap, PPMU_PMCNT3_HIGH, &pmcnt3_high);
232 		if (ret < 0)
233 			return ret;
234 
235 		ret = regmap_read(info->regmap, PPMU_PMCNT3_LOW, &pmcnt3_low);
236 		if (ret < 0)
237 			return ret;
238 
239 		edata->load_count = ((pmcnt3_high << 8) | pmcnt3_low);
240 		break;
241 	default:
242 		return -EINVAL;
243 	}
244 
245 	/* Disable specific counter */
246 	ret = regmap_read(info->regmap, PPMU_CNTENC, &cntenc);
247 	if (ret < 0)
248 		return ret;
249 
250 	cntenc |= (PPMU_CCNT_MASK | (PPMU_ENABLE << id));
251 	ret = regmap_write(info->regmap, PPMU_CNTENC, cntenc);
252 	if (ret < 0)
253 		return ret;
254 
255 	dev_dbg(&edev->dev, "%s (event: %ld/%ld)\n", edev->desc->name,
256 					edata->load_count, edata->total_count);
257 
258 	return 0;
259 }
260 
261 static const struct devfreq_event_ops exynos_ppmu_ops = {
262 	.disable = exynos_ppmu_disable,
263 	.set_event = exynos_ppmu_set_event,
264 	.get_event = exynos_ppmu_get_event,
265 };
266 
267 /*
268  * The devfreq-event ops structure for PPMU v2.0
269  */
270 static int exynos_ppmu_v2_disable(struct devfreq_event_dev *edev)
271 {
272 	struct exynos_ppmu *info = devfreq_event_get_drvdata(edev);
273 	int ret;
274 	u32 pmnc, clear;
275 
276 	/* Disable all counters */
277 	clear = (PPMU_CCNT_MASK | PPMU_PMCNT0_MASK | PPMU_PMCNT1_MASK
278 		| PPMU_PMCNT2_MASK | PPMU_PMCNT3_MASK);
279 	ret = regmap_write(info->regmap, PPMU_V2_FLAG, clear);
280 	if (ret < 0)
281 		return ret;
282 
283 	ret = regmap_write(info->regmap, PPMU_V2_INTENC, clear);
284 	if (ret < 0)
285 		return ret;
286 
287 	ret = regmap_write(info->regmap, PPMU_V2_CNTENC, clear);
288 	if (ret < 0)
289 		return ret;
290 
291 	ret = regmap_write(info->regmap, PPMU_V2_CNT_RESET, clear);
292 	if (ret < 0)
293 		return ret;
294 
295 	ret = regmap_write(info->regmap, PPMU_V2_CIG_CFG0, 0x0);
296 	if (ret < 0)
297 		return ret;
298 
299 	ret = regmap_write(info->regmap, PPMU_V2_CIG_CFG1, 0x0);
300 	if (ret < 0)
301 		return ret;
302 
303 	ret = regmap_write(info->regmap, PPMU_V2_CIG_CFG2, 0x0);
304 	if (ret < 0)
305 		return ret;
306 
307 	ret = regmap_write(info->regmap, PPMU_V2_CIG_RESULT, 0x0);
308 	if (ret < 0)
309 		return ret;
310 
311 	ret = regmap_write(info->regmap, PPMU_V2_CNT_AUTO, 0x0);
312 	if (ret < 0)
313 		return ret;
314 
315 	ret = regmap_write(info->regmap, PPMU_V2_CH_EV0_TYPE, 0x0);
316 	if (ret < 0)
317 		return ret;
318 
319 	ret = regmap_write(info->regmap, PPMU_V2_CH_EV1_TYPE, 0x0);
320 	if (ret < 0)
321 		return ret;
322 
323 	ret = regmap_write(info->regmap, PPMU_V2_CH_EV2_TYPE, 0x0);
324 	if (ret < 0)
325 		return ret;
326 
327 	ret = regmap_write(info->regmap, PPMU_V2_CH_EV3_TYPE, 0x0);
328 	if (ret < 0)
329 		return ret;
330 
331 	ret = regmap_write(info->regmap, PPMU_V2_SM_ID_V, 0x0);
332 	if (ret < 0)
333 		return ret;
334 
335 	ret = regmap_write(info->regmap, PPMU_V2_SM_ID_A, 0x0);
336 	if (ret < 0)
337 		return ret;
338 
339 	ret = regmap_write(info->regmap, PPMU_V2_SM_OTHERS_V, 0x0);
340 	if (ret < 0)
341 		return ret;
342 
343 	ret = regmap_write(info->regmap, PPMU_V2_SM_OTHERS_A, 0x0);
344 	if (ret < 0)
345 		return ret;
346 
347 	ret = regmap_write(info->regmap, PPMU_V2_INTERRUPT_RESET, 0x0);
348 	if (ret < 0)
349 		return ret;
350 
351 	/* Disable PPMU */
352 	ret = regmap_read(info->regmap, PPMU_V2_PMNC, &pmnc);
353 	if (ret < 0)
354 		return ret;
355 
356 	pmnc &= ~PPMU_PMNC_ENABLE_MASK;
357 	ret = regmap_write(info->regmap, PPMU_V2_PMNC, pmnc);
358 	if (ret < 0)
359 		return ret;
360 
361 	return 0;
362 }
363 
364 static int exynos_ppmu_v2_set_event(struct devfreq_event_dev *edev)
365 {
366 	struct exynos_ppmu *info = devfreq_event_get_drvdata(edev);
367 	unsigned int pmnc, cntens;
368 	int id = exynos_ppmu_find_ppmu_id(edev);
369 	int ret;
370 
371 	/* Enable all counters */
372 	ret = regmap_read(info->regmap, PPMU_V2_CNTENS, &cntens);
373 	if (ret < 0)
374 		return ret;
375 
376 	cntens |= (PPMU_CCNT_MASK | (PPMU_ENABLE << id));
377 	ret = regmap_write(info->regmap, PPMU_V2_CNTENS, cntens);
378 	if (ret < 0)
379 		return ret;
380 
381 	/* Set the event of proper data type monitoring */
382 	ret = regmap_write(info->regmap, PPMU_V2_CH_EVx_TYPE(id),
383 			   edev->desc->event_type);
384 	if (ret < 0)
385 		return ret;
386 
387 	/* Reset cycle counter/performance counter and enable PPMU */
388 	ret = regmap_read(info->regmap, PPMU_V2_PMNC, &pmnc);
389 	if (ret < 0)
390 		return ret;
391 
392 	pmnc &= ~(PPMU_PMNC_ENABLE_MASK
393 			| PPMU_PMNC_COUNTER_RESET_MASK
394 			| PPMU_PMNC_CC_RESET_MASK
395 			| PPMU_PMNC_CC_DIVIDER_MASK
396 			| PPMU_V2_PMNC_START_MODE_MASK);
397 	pmnc |= (PPMU_ENABLE << PPMU_PMNC_ENABLE_SHIFT);
398 	pmnc |= (PPMU_ENABLE << PPMU_PMNC_COUNTER_RESET_SHIFT);
399 	pmnc |= (PPMU_ENABLE << PPMU_PMNC_CC_RESET_SHIFT);
400 	pmnc |= (PPMU_V2_MODE_MANUAL << PPMU_V2_PMNC_START_MODE_SHIFT);
401 
402 	ret = regmap_write(info->regmap, PPMU_V2_PMNC, pmnc);
403 	if (ret < 0)
404 		return ret;
405 
406 	return 0;
407 }
408 
409 static int exynos_ppmu_v2_get_event(struct devfreq_event_dev *edev,
410 				    struct devfreq_event_data *edata)
411 {
412 	struct exynos_ppmu *info = devfreq_event_get_drvdata(edev);
413 	int id = exynos_ppmu_find_ppmu_id(edev);
414 	int ret;
415 	unsigned int pmnc, cntenc;
416 	unsigned int pmcnt_high, pmcnt_low;
417 	unsigned int total_count, count;
418 	unsigned long load_count = 0;
419 
420 	/* Disable PPMU */
421 	ret = regmap_read(info->regmap, PPMU_V2_PMNC, &pmnc);
422 	if (ret < 0)
423 		return ret;
424 
425 	pmnc &= ~PPMU_PMNC_ENABLE_MASK;
426 	ret = regmap_write(info->regmap, PPMU_V2_PMNC, pmnc);
427 	if (ret < 0)
428 		return ret;
429 
430 	/* Read cycle count and performance count */
431 	ret = regmap_read(info->regmap, PPMU_V2_CCNT, &total_count);
432 	if (ret < 0)
433 		return ret;
434 	edata->total_count = total_count;
435 
436 	switch (id) {
437 	case PPMU_PMNCNT0:
438 	case PPMU_PMNCNT1:
439 	case PPMU_PMNCNT2:
440 		ret = regmap_read(info->regmap, PPMU_V2_PMNCT(id), &count);
441 		if (ret < 0)
442 			return ret;
443 		load_count = count;
444 		break;
445 	case PPMU_PMNCNT3:
446 		ret = regmap_read(info->regmap, PPMU_V2_PMCNT3_HIGH,
447 						&pmcnt_high);
448 		if (ret < 0)
449 			return ret;
450 
451 		ret = regmap_read(info->regmap, PPMU_V2_PMCNT3_LOW, &pmcnt_low);
452 		if (ret < 0)
453 			return ret;
454 
455 		load_count = ((u64)((pmcnt_high & 0xff)) << 32)+ (u64)pmcnt_low;
456 		break;
457 	}
458 	edata->load_count = load_count;
459 
460 	/* Disable all counters */
461 	ret = regmap_read(info->regmap, PPMU_V2_CNTENC, &cntenc);
462 	if (ret < 0)
463 		return 0;
464 
465 	cntenc |= (PPMU_CCNT_MASK | (PPMU_ENABLE << id));
466 	ret = regmap_write(info->regmap, PPMU_V2_CNTENC, cntenc);
467 	if (ret < 0)
468 		return ret;
469 
470 	dev_dbg(&edev->dev, "%25s (load: %ld / %ld)\n", edev->desc->name,
471 					edata->load_count, edata->total_count);
472 	return 0;
473 }
474 
475 static const struct devfreq_event_ops exynos_ppmu_v2_ops = {
476 	.disable = exynos_ppmu_v2_disable,
477 	.set_event = exynos_ppmu_v2_set_event,
478 	.get_event = exynos_ppmu_v2_get_event,
479 };
480 
481 static const struct of_device_id exynos_ppmu_id_match[] = {
482 	{
483 		.compatible = "samsung,exynos-ppmu",
484 		.data = (void *)EXYNOS_TYPE_PPMU,
485 	}, {
486 		.compatible = "samsung,exynos-ppmu-v2",
487 		.data = (void *)EXYNOS_TYPE_PPMU_V2,
488 	},
489 	{ /* sentinel */ },
490 };
491 MODULE_DEVICE_TABLE(of, exynos_ppmu_id_match);
492 
493 static int of_get_devfreq_events(struct device_node *np,
494 				 struct exynos_ppmu *info)
495 {
496 	struct devfreq_event_desc *desc;
497 	struct device *dev = info->dev;
498 	struct device_node *events_np, *node;
499 	int i, j, count;
500 	const struct of_device_id *of_id;
501 	int ret;
502 
503 	events_np = of_get_child_by_name(np, "events");
504 	if (!events_np) {
505 		dev_err(dev,
506 			"failed to get child node of devfreq-event devices\n");
507 		return -EINVAL;
508 	}
509 
510 	count = of_get_child_count(events_np);
511 	desc = devm_kcalloc(dev, count, sizeof(*desc), GFP_KERNEL);
512 	if (!desc)
513 		return -ENOMEM;
514 	info->num_events = count;
515 
516 	of_id = of_match_device(exynos_ppmu_id_match, dev);
517 	if (of_id)
518 		info->ppmu_type = (enum exynos_ppmu_type)of_id->data;
519 	else
520 		return -EINVAL;
521 
522 	j = 0;
523 	for_each_child_of_node(events_np, node) {
524 		for (i = 0; i < ARRAY_SIZE(ppmu_events); i++) {
525 			if (!ppmu_events[i].name)
526 				continue;
527 
528 			if (of_node_name_eq(node, ppmu_events[i].name))
529 				break;
530 		}
531 
532 		if (i == ARRAY_SIZE(ppmu_events)) {
533 			dev_warn(dev,
534 				"don't know how to configure events : %pOFn\n",
535 				node);
536 			continue;
537 		}
538 
539 		switch (info->ppmu_type) {
540 		case EXYNOS_TYPE_PPMU:
541 			desc[j].ops = &exynos_ppmu_ops;
542 			break;
543 		case EXYNOS_TYPE_PPMU_V2:
544 			desc[j].ops = &exynos_ppmu_v2_ops;
545 			break;
546 		}
547 
548 		desc[j].driver_data = info;
549 
550 		of_property_read_string(node, "event-name", &desc[j].name);
551 		ret = of_property_read_u32(node, "event-data-type",
552 					   &desc[j].event_type);
553 		if (ret) {
554 			/* Set the event of proper data type counting.
555 			 * Check if the data type has been defined in DT,
556 			 * use default if not.
557 			 */
558 			if (info->ppmu_type == EXYNOS_TYPE_PPMU_V2) {
559 				struct devfreq_event_dev edev;
560 				int id;
561 				/* Not all registers take the same value for
562 				 * read+write data count.
563 				 */
564 				edev.desc = &desc[j];
565 				id = exynos_ppmu_find_ppmu_id(&edev);
566 
567 				switch (id) {
568 				case PPMU_PMNCNT0:
569 				case PPMU_PMNCNT1:
570 				case PPMU_PMNCNT2:
571 					desc[j].event_type = PPMU_V2_RO_DATA_CNT
572 						| PPMU_V2_WO_DATA_CNT;
573 					break;
574 				case PPMU_PMNCNT3:
575 					desc[j].event_type =
576 						PPMU_V2_EVT3_RW_DATA_CNT;
577 					break;
578 				}
579 			} else {
580 				desc[j].event_type = PPMU_RO_DATA_CNT |
581 					PPMU_WO_DATA_CNT;
582 			}
583 		}
584 
585 		j++;
586 	}
587 	info->desc = desc;
588 
589 	of_node_put(events_np);
590 
591 	return 0;
592 }
593 
594 static struct regmap_config exynos_ppmu_regmap_config = {
595 	.reg_bits = 32,
596 	.val_bits = 32,
597 	.reg_stride = 4,
598 };
599 
600 static int exynos_ppmu_parse_dt(struct platform_device *pdev,
601 				struct exynos_ppmu *info)
602 {
603 	struct device *dev = info->dev;
604 	struct device_node *np = dev->of_node;
605 	struct resource *res;
606 	void __iomem *base;
607 	int ret = 0;
608 
609 	if (!np) {
610 		dev_err(dev, "failed to find devicetree node\n");
611 		return -EINVAL;
612 	}
613 
614 	/* Maps the memory mapped IO to control PPMU register */
615 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
616 	base = devm_ioremap_resource(dev, res);
617 	if (IS_ERR(base))
618 		return PTR_ERR(base);
619 
620 	exynos_ppmu_regmap_config.max_register = resource_size(res) - 4;
621 	info->regmap = devm_regmap_init_mmio(dev, base,
622 					&exynos_ppmu_regmap_config);
623 	if (IS_ERR(info->regmap)) {
624 		dev_err(dev, "failed to initialize regmap\n");
625 		return PTR_ERR(info->regmap);
626 	}
627 
628 	info->ppmu.clk = devm_clk_get(dev, "ppmu");
629 	if (IS_ERR(info->ppmu.clk)) {
630 		info->ppmu.clk = NULL;
631 		dev_warn(dev, "cannot get PPMU clock\n");
632 	}
633 
634 	ret = of_get_devfreq_events(np, info);
635 	if (ret < 0) {
636 		dev_err(dev, "failed to parse exynos ppmu dt node\n");
637 		return ret;
638 	}
639 
640 	return 0;
641 }
642 
643 static int exynos_ppmu_probe(struct platform_device *pdev)
644 {
645 	struct exynos_ppmu *info;
646 	struct devfreq_event_dev **edev;
647 	struct devfreq_event_desc *desc;
648 	int i, ret = 0, size;
649 
650 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
651 	if (!info)
652 		return -ENOMEM;
653 
654 	info->dev = &pdev->dev;
655 
656 	/* Parse dt data to get resource */
657 	ret = exynos_ppmu_parse_dt(pdev, info);
658 	if (ret < 0) {
659 		dev_err(&pdev->dev,
660 			"failed to parse devicetree for resource\n");
661 		return ret;
662 	}
663 	desc = info->desc;
664 
665 	size = sizeof(struct devfreq_event_dev *) * info->num_events;
666 	info->edev = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
667 	if (!info->edev)
668 		return -ENOMEM;
669 
670 	edev = info->edev;
671 	platform_set_drvdata(pdev, info);
672 
673 	for (i = 0; i < info->num_events; i++) {
674 		edev[i] = devm_devfreq_event_add_edev(&pdev->dev, &desc[i]);
675 		if (IS_ERR(edev[i])) {
676 			ret = PTR_ERR(edev[i]);
677 			dev_err(&pdev->dev,
678 				"failed to add devfreq-event device\n");
679 			return PTR_ERR(edev[i]);
680 		}
681 
682 		pr_info("exynos-ppmu: new PPMU device registered %s (%s)\n",
683 			dev_name(&pdev->dev), desc[i].name);
684 	}
685 
686 	ret = clk_prepare_enable(info->ppmu.clk);
687 	if (ret) {
688 		dev_err(&pdev->dev, "failed to prepare ppmu clock\n");
689 		return ret;
690 	}
691 
692 	return 0;
693 }
694 
695 static int exynos_ppmu_remove(struct platform_device *pdev)
696 {
697 	struct exynos_ppmu *info = platform_get_drvdata(pdev);
698 
699 	clk_disable_unprepare(info->ppmu.clk);
700 
701 	return 0;
702 }
703 
704 static struct platform_driver exynos_ppmu_driver = {
705 	.probe	= exynos_ppmu_probe,
706 	.remove	= exynos_ppmu_remove,
707 	.driver = {
708 		.name	= "exynos-ppmu",
709 		.of_match_table = exynos_ppmu_id_match,
710 	},
711 };
712 module_platform_driver(exynos_ppmu_driver);
713 
714 MODULE_DESCRIPTION("Exynos PPMU(Platform Performance Monitoring Unit) driver");
715 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
716 MODULE_LICENSE("GPL");
717