xref: /openbmc/linux/drivers/pwm/pwm-tiehrpwm.c (revision e285d5bf)
1 /*
2  * EHRPWM PWM driver
3  *
4  * Copyright (C) 2012 Texas Instruments, Inc. - http://www.ti.com/
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19  */
20 
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
23 #include <linux/pwm.h>
24 #include <linux/io.h>
25 #include <linux/err.h>
26 #include <linux/clk.h>
27 #include <linux/pm_runtime.h>
28 #include <linux/of_device.h>
29 
30 /* EHRPWM registers and bits definitions */
31 
32 /* Time base module registers */
33 #define TBCTL			0x00
34 #define TBPRD			0x0A
35 
36 #define TBCTL_PRDLD_MASK	BIT(3)
37 #define TBCTL_PRDLD_SHDW	0
38 #define TBCTL_PRDLD_IMDT	BIT(3)
39 #define TBCTL_CLKDIV_MASK	(BIT(12) | BIT(11) | BIT(10) | BIT(9) | \
40 				BIT(8) | BIT(7))
41 #define TBCTL_CTRMODE_MASK	(BIT(1) | BIT(0))
42 #define TBCTL_CTRMODE_UP	0
43 #define TBCTL_CTRMODE_DOWN	BIT(0)
44 #define TBCTL_CTRMODE_UPDOWN	BIT(1)
45 #define TBCTL_CTRMODE_FREEZE	(BIT(1) | BIT(0))
46 
47 #define TBCTL_HSPCLKDIV_SHIFT	7
48 #define TBCTL_CLKDIV_SHIFT	10
49 
50 #define CLKDIV_MAX		7
51 #define HSPCLKDIV_MAX		7
52 #define PERIOD_MAX		0xFFFF
53 
54 /* compare module registers */
55 #define CMPA			0x12
56 #define CMPB			0x14
57 
58 /* Action qualifier module registers */
59 #define AQCTLA			0x16
60 #define AQCTLB			0x18
61 #define AQSFRC			0x1A
62 #define AQCSFRC			0x1C
63 
64 #define AQCTL_CBU_MASK		(BIT(9) | BIT(8))
65 #define AQCTL_CBU_FRCLOW	BIT(8)
66 #define AQCTL_CBU_FRCHIGH	BIT(9)
67 #define AQCTL_CBU_FRCTOGGLE	(BIT(9) | BIT(8))
68 #define AQCTL_CAU_MASK		(BIT(5) | BIT(4))
69 #define AQCTL_CAU_FRCLOW	BIT(4)
70 #define AQCTL_CAU_FRCHIGH	BIT(5)
71 #define AQCTL_CAU_FRCTOGGLE	(BIT(5) | BIT(4))
72 #define AQCTL_PRD_MASK		(BIT(3) | BIT(2))
73 #define AQCTL_PRD_FRCLOW	BIT(2)
74 #define AQCTL_PRD_FRCHIGH	BIT(3)
75 #define AQCTL_PRD_FRCTOGGLE	(BIT(3) | BIT(2))
76 #define AQCTL_ZRO_MASK		(BIT(1) | BIT(0))
77 #define AQCTL_ZRO_FRCLOW	BIT(0)
78 #define AQCTL_ZRO_FRCHIGH	BIT(1)
79 #define AQCTL_ZRO_FRCTOGGLE	(BIT(1) | BIT(0))
80 
81 #define AQCTL_CHANA_POLNORMAL	(AQCTL_CAU_FRCLOW | AQCTL_PRD_FRCHIGH | \
82 				AQCTL_ZRO_FRCHIGH)
83 #define AQCTL_CHANA_POLINVERSED	(AQCTL_CAU_FRCHIGH | AQCTL_PRD_FRCLOW | \
84 				AQCTL_ZRO_FRCLOW)
85 #define AQCTL_CHANB_POLNORMAL	(AQCTL_CBU_FRCLOW | AQCTL_PRD_FRCHIGH | \
86 				AQCTL_ZRO_FRCHIGH)
87 #define AQCTL_CHANB_POLINVERSED	(AQCTL_CBU_FRCHIGH | AQCTL_PRD_FRCLOW | \
88 				AQCTL_ZRO_FRCLOW)
89 
90 #define AQSFRC_RLDCSF_MASK	(BIT(7) | BIT(6))
91 #define AQSFRC_RLDCSF_ZRO	0
92 #define AQSFRC_RLDCSF_PRD	BIT(6)
93 #define AQSFRC_RLDCSF_ZROPRD	BIT(7)
94 #define AQSFRC_RLDCSF_IMDT	(BIT(7) | BIT(6))
95 
96 #define AQCSFRC_CSFB_MASK	(BIT(3) | BIT(2))
97 #define AQCSFRC_CSFB_FRCDIS	0
98 #define AQCSFRC_CSFB_FRCLOW	BIT(2)
99 #define AQCSFRC_CSFB_FRCHIGH	BIT(3)
100 #define AQCSFRC_CSFB_DISSWFRC	(BIT(3) | BIT(2))
101 #define AQCSFRC_CSFA_MASK	(BIT(1) | BIT(0))
102 #define AQCSFRC_CSFA_FRCDIS	0
103 #define AQCSFRC_CSFA_FRCLOW	BIT(0)
104 #define AQCSFRC_CSFA_FRCHIGH	BIT(1)
105 #define AQCSFRC_CSFA_DISSWFRC	(BIT(1) | BIT(0))
106 
107 #define NUM_PWM_CHANNEL		2	/* EHRPWM channels */
108 
109 struct ehrpwm_context {
110 	u16 tbctl;
111 	u16 tbprd;
112 	u16 cmpa;
113 	u16 cmpb;
114 	u16 aqctla;
115 	u16 aqctlb;
116 	u16 aqsfrc;
117 	u16 aqcsfrc;
118 };
119 
120 struct ehrpwm_pwm_chip {
121 	struct pwm_chip chip;
122 	unsigned long clk_rate;
123 	void __iomem *mmio_base;
124 	unsigned long period_cycles[NUM_PWM_CHANNEL];
125 	enum pwm_polarity polarity[NUM_PWM_CHANNEL];
126 	struct clk *tbclk;
127 	struct ehrpwm_context ctx;
128 };
129 
130 static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
131 {
132 	return container_of(chip, struct ehrpwm_pwm_chip, chip);
133 }
134 
135 static inline u16 ehrpwm_read(void __iomem *base, unsigned int offset)
136 {
137 	return readw(base + offset);
138 }
139 
140 static inline void ehrpwm_write(void __iomem *base, unsigned int offset,
141 				u16 value)
142 {
143 	writew(value, base + offset);
144 }
145 
146 static void ehrpwm_modify(void __iomem *base, unsigned int offset, u16 mask,
147 			  u16 value)
148 {
149 	unsigned short val;
150 
151 	val = readw(base + offset);
152 	val &= ~mask;
153 	val |= value & mask;
154 	writew(val, base + offset);
155 }
156 
157 /**
158  * set_prescale_div -	Set up the prescaler divider function
159  * @rqst_prescaler:	prescaler value min
160  * @prescale_div:	prescaler value set
161  * @tb_clk_div:		Time Base Control prescaler bits
162  */
163 static int set_prescale_div(unsigned long rqst_prescaler, u16 *prescale_div,
164 			    u16 *tb_clk_div)
165 {
166 	unsigned int clkdiv, hspclkdiv;
167 
168 	for (clkdiv = 0; clkdiv <= CLKDIV_MAX; clkdiv++) {
169 		for (hspclkdiv = 0; hspclkdiv <= HSPCLKDIV_MAX; hspclkdiv++) {
170 			/*
171 			 * calculations for prescaler value :
172 			 * prescale_div = HSPCLKDIVIDER * CLKDIVIDER.
173 			 * HSPCLKDIVIDER =  2 ** hspclkdiv
174 			 * CLKDIVIDER = (1),		if clkdiv == 0 *OR*
175 			 *		(2 * clkdiv),	if clkdiv != 0
176 			 *
177 			 * Configure prescale_div value such that period
178 			 * register value is less than 65535.
179 			 */
180 
181 			*prescale_div = (1 << clkdiv) *
182 					(hspclkdiv ? (hspclkdiv * 2) : 1);
183 			if (*prescale_div > rqst_prescaler) {
184 				*tb_clk_div = (clkdiv << TBCTL_CLKDIV_SHIFT) |
185 					(hspclkdiv << TBCTL_HSPCLKDIV_SHIFT);
186 				return 0;
187 			}
188 		}
189 	}
190 
191 	return 1;
192 }
193 
194 static void configure_polarity(struct ehrpwm_pwm_chip *pc, int chan)
195 {
196 	u16 aqctl_val, aqctl_mask;
197 	unsigned int aqctl_reg;
198 
199 	/*
200 	 * Configure PWM output to HIGH/LOW level on counter
201 	 * reaches compare register value and LOW/HIGH level
202 	 * on counter value reaches period register value and
203 	 * zero value on counter
204 	 */
205 	if (chan == 1) {
206 		aqctl_reg = AQCTLB;
207 		aqctl_mask = AQCTL_CBU_MASK;
208 
209 		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
210 			aqctl_val = AQCTL_CHANB_POLINVERSED;
211 		else
212 			aqctl_val = AQCTL_CHANB_POLNORMAL;
213 	} else {
214 		aqctl_reg = AQCTLA;
215 		aqctl_mask = AQCTL_CAU_MASK;
216 
217 		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
218 			aqctl_val = AQCTL_CHANA_POLINVERSED;
219 		else
220 			aqctl_val = AQCTL_CHANA_POLNORMAL;
221 	}
222 
223 	aqctl_mask |= AQCTL_PRD_MASK | AQCTL_ZRO_MASK;
224 	ehrpwm_modify(pc->mmio_base, aqctl_reg, aqctl_mask, aqctl_val);
225 }
226 
227 /*
228  * period_ns = 10^9 * (ps_divval * period_cycles) / PWM_CLK_RATE
229  * duty_ns   = 10^9 * (ps_divval * duty_cycles) / PWM_CLK_RATE
230  */
231 static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
232 			     int duty_ns, int period_ns)
233 {
234 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
235 	u32 period_cycles, duty_cycles;
236 	u16 ps_divval, tb_divval;
237 	unsigned int i, cmp_reg;
238 	unsigned long long c;
239 
240 	if (period_ns > NSEC_PER_SEC)
241 		return -ERANGE;
242 
243 	c = pc->clk_rate;
244 	c = c * period_ns;
245 	do_div(c, NSEC_PER_SEC);
246 	period_cycles = (unsigned long)c;
247 
248 	if (period_cycles < 1) {
249 		period_cycles = 1;
250 		duty_cycles = 1;
251 	} else {
252 		c = pc->clk_rate;
253 		c = c * duty_ns;
254 		do_div(c, NSEC_PER_SEC);
255 		duty_cycles = (unsigned long)c;
256 	}
257 
258 	/*
259 	 * Period values should be same for multiple PWM channels as IP uses
260 	 * same period register for multiple channels.
261 	 */
262 	for (i = 0; i < NUM_PWM_CHANNEL; i++) {
263 		if (pc->period_cycles[i] &&
264 				(pc->period_cycles[i] != period_cycles)) {
265 			/*
266 			 * Allow channel to reconfigure period if no other
267 			 * channels being configured.
268 			 */
269 			if (i == pwm->hwpwm)
270 				continue;
271 
272 			dev_err(chip->dev,
273 				"period value conflicts with channel %u\n",
274 				i);
275 			return -EINVAL;
276 		}
277 	}
278 
279 	pc->period_cycles[pwm->hwpwm] = period_cycles;
280 
281 	/* Configure clock prescaler to support Low frequency PWM wave */
282 	if (set_prescale_div(period_cycles/PERIOD_MAX, &ps_divval,
283 			     &tb_divval)) {
284 		dev_err(chip->dev, "Unsupported values\n");
285 		return -EINVAL;
286 	}
287 
288 	pm_runtime_get_sync(chip->dev);
289 
290 	/* Update clock prescaler values */
291 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CLKDIV_MASK, tb_divval);
292 
293 	/* Update period & duty cycle with presacler division */
294 	period_cycles = period_cycles / ps_divval;
295 	duty_cycles = duty_cycles / ps_divval;
296 
297 	/* Configure shadow loading on Period register */
298 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_PRDLD_MASK, TBCTL_PRDLD_SHDW);
299 
300 	ehrpwm_write(pc->mmio_base, TBPRD, period_cycles);
301 
302 	/* Configure ehrpwm counter for up-count mode */
303 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CTRMODE_MASK,
304 		      TBCTL_CTRMODE_UP);
305 
306 	if (pwm->hwpwm == 1)
307 		/* Channel 1 configured with compare B register */
308 		cmp_reg = CMPB;
309 	else
310 		/* Channel 0 configured with compare A register */
311 		cmp_reg = CMPA;
312 
313 	ehrpwm_write(pc->mmio_base, cmp_reg, duty_cycles);
314 
315 	pm_runtime_put_sync(chip->dev);
316 
317 	return 0;
318 }
319 
320 static int ehrpwm_pwm_set_polarity(struct pwm_chip *chip,
321 				   struct pwm_device *pwm,
322 				   enum pwm_polarity polarity)
323 {
324 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
325 
326 	/* Configuration of polarity in hardware delayed, do at enable */
327 	pc->polarity[pwm->hwpwm] = polarity;
328 
329 	return 0;
330 }
331 
332 static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
333 {
334 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
335 	u16 aqcsfrc_val, aqcsfrc_mask;
336 	int ret;
337 
338 	/* Leave clock enabled on enabling PWM */
339 	pm_runtime_get_sync(chip->dev);
340 
341 	/* Disabling Action Qualifier on PWM output */
342 	if (pwm->hwpwm) {
343 		aqcsfrc_val = AQCSFRC_CSFB_FRCDIS;
344 		aqcsfrc_mask = AQCSFRC_CSFB_MASK;
345 	} else {
346 		aqcsfrc_val = AQCSFRC_CSFA_FRCDIS;
347 		aqcsfrc_mask = AQCSFRC_CSFA_MASK;
348 	}
349 
350 	/* Changes to shadow mode */
351 	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
352 		      AQSFRC_RLDCSF_ZRO);
353 
354 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
355 
356 	/* Channels polarity can be configured from action qualifier module */
357 	configure_polarity(pc, pwm->hwpwm);
358 
359 	/* Enable TBCLK */
360 	ret = clk_enable(pc->tbclk);
361 	if (ret) {
362 		dev_err(chip->dev, "Failed to enable TBCLK for %s: %d\n",
363 			dev_name(pc->chip.dev), ret);
364 		return ret;
365 	}
366 
367 	return 0;
368 }
369 
370 static void ehrpwm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
371 {
372 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
373 	u16 aqcsfrc_val, aqcsfrc_mask;
374 
375 	/* Action Qualifier puts PWM output low forcefully */
376 	if (pwm->hwpwm) {
377 		aqcsfrc_val = AQCSFRC_CSFB_FRCLOW;
378 		aqcsfrc_mask = AQCSFRC_CSFB_MASK;
379 	} else {
380 		aqcsfrc_val = AQCSFRC_CSFA_FRCLOW;
381 		aqcsfrc_mask = AQCSFRC_CSFA_MASK;
382 	}
383 
384 	/* Update shadow register first before modifying active register */
385 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
386 	/*
387 	 * Changes to immediate action on Action Qualifier. This puts
388 	 * Action Qualifier control on PWM output from next TBCLK
389 	 */
390 	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
391 		      AQSFRC_RLDCSF_IMDT);
392 
393 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
394 
395 	/* Disabling TBCLK on PWM disable */
396 	clk_disable(pc->tbclk);
397 
398 	/* Disable clock on PWM disable */
399 	pm_runtime_put_sync(chip->dev);
400 }
401 
402 static void ehrpwm_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
403 {
404 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
405 
406 	if (pwm_is_enabled(pwm)) {
407 		dev_warn(chip->dev, "Removing PWM device without disabling\n");
408 		pm_runtime_put_sync(chip->dev);
409 	}
410 
411 	/* set period value to zero on free */
412 	pc->period_cycles[pwm->hwpwm] = 0;
413 }
414 
415 static const struct pwm_ops ehrpwm_pwm_ops = {
416 	.free = ehrpwm_pwm_free,
417 	.config = ehrpwm_pwm_config,
418 	.set_polarity = ehrpwm_pwm_set_polarity,
419 	.enable = ehrpwm_pwm_enable,
420 	.disable = ehrpwm_pwm_disable,
421 	.owner = THIS_MODULE,
422 };
423 
424 static const struct of_device_id ehrpwm_of_match[] = {
425 	{ .compatible = "ti,am3352-ehrpwm" },
426 	{ .compatible = "ti,am33xx-ehrpwm" },
427 	{},
428 };
429 MODULE_DEVICE_TABLE(of, ehrpwm_of_match);
430 
431 static int ehrpwm_pwm_probe(struct platform_device *pdev)
432 {
433 	struct device_node *np = pdev->dev.of_node;
434 	struct ehrpwm_pwm_chip *pc;
435 	struct resource *r;
436 	struct clk *clk;
437 	int ret;
438 
439 	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
440 	if (!pc)
441 		return -ENOMEM;
442 
443 	clk = devm_clk_get(&pdev->dev, "fck");
444 	if (IS_ERR(clk)) {
445 		if (of_device_is_compatible(np, "ti,am33xx-ecap")) {
446 			dev_warn(&pdev->dev, "Binding is obsolete.\n");
447 			clk = devm_clk_get(pdev->dev.parent, "fck");
448 		}
449 	}
450 
451 	if (IS_ERR(clk)) {
452 		dev_err(&pdev->dev, "failed to get clock\n");
453 		return PTR_ERR(clk);
454 	}
455 
456 	pc->clk_rate = clk_get_rate(clk);
457 	if (!pc->clk_rate) {
458 		dev_err(&pdev->dev, "failed to get clock rate\n");
459 		return -EINVAL;
460 	}
461 
462 	pc->chip.dev = &pdev->dev;
463 	pc->chip.ops = &ehrpwm_pwm_ops;
464 	pc->chip.of_xlate = of_pwm_xlate_with_flags;
465 	pc->chip.of_pwm_n_cells = 3;
466 	pc->chip.base = -1;
467 	pc->chip.npwm = NUM_PWM_CHANNEL;
468 
469 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
470 	pc->mmio_base = devm_ioremap_resource(&pdev->dev, r);
471 	if (IS_ERR(pc->mmio_base))
472 		return PTR_ERR(pc->mmio_base);
473 
474 	/* Acquire tbclk for Time Base EHRPWM submodule */
475 	pc->tbclk = devm_clk_get(&pdev->dev, "tbclk");
476 	if (IS_ERR(pc->tbclk)) {
477 		dev_err(&pdev->dev, "Failed to get tbclk\n");
478 		return PTR_ERR(pc->tbclk);
479 	}
480 
481 	ret = clk_prepare(pc->tbclk);
482 	if (ret < 0) {
483 		dev_err(&pdev->dev, "clk_prepare() failed: %d\n", ret);
484 		return ret;
485 	}
486 
487 	ret = pwmchip_add(&pc->chip);
488 	if (ret < 0) {
489 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
490 		goto err_clk_unprepare;
491 	}
492 
493 	platform_set_drvdata(pdev, pc);
494 	pm_runtime_enable(&pdev->dev);
495 
496 	return 0;
497 
498 err_clk_unprepare:
499 	clk_unprepare(pc->tbclk);
500 
501 	return ret;
502 }
503 
504 static int ehrpwm_pwm_remove(struct platform_device *pdev)
505 {
506 	struct ehrpwm_pwm_chip *pc = platform_get_drvdata(pdev);
507 
508 	clk_unprepare(pc->tbclk);
509 
510 	pm_runtime_disable(&pdev->dev);
511 
512 	return pwmchip_remove(&pc->chip);
513 }
514 
515 #ifdef CONFIG_PM_SLEEP
516 static void ehrpwm_pwm_save_context(struct ehrpwm_pwm_chip *pc)
517 {
518 	pm_runtime_get_sync(pc->chip.dev);
519 
520 	pc->ctx.tbctl = ehrpwm_read(pc->mmio_base, TBCTL);
521 	pc->ctx.tbprd = ehrpwm_read(pc->mmio_base, TBPRD);
522 	pc->ctx.cmpa = ehrpwm_read(pc->mmio_base, CMPA);
523 	pc->ctx.cmpb = ehrpwm_read(pc->mmio_base, CMPB);
524 	pc->ctx.aqctla = ehrpwm_read(pc->mmio_base, AQCTLA);
525 	pc->ctx.aqctlb = ehrpwm_read(pc->mmio_base, AQCTLB);
526 	pc->ctx.aqsfrc = ehrpwm_read(pc->mmio_base, AQSFRC);
527 	pc->ctx.aqcsfrc = ehrpwm_read(pc->mmio_base, AQCSFRC);
528 
529 	pm_runtime_put_sync(pc->chip.dev);
530 }
531 
532 static void ehrpwm_pwm_restore_context(struct ehrpwm_pwm_chip *pc)
533 {
534 	ehrpwm_write(pc->mmio_base, TBPRD, pc->ctx.tbprd);
535 	ehrpwm_write(pc->mmio_base, CMPA, pc->ctx.cmpa);
536 	ehrpwm_write(pc->mmio_base, CMPB, pc->ctx.cmpb);
537 	ehrpwm_write(pc->mmio_base, AQCTLA, pc->ctx.aqctla);
538 	ehrpwm_write(pc->mmio_base, AQCTLB, pc->ctx.aqctlb);
539 	ehrpwm_write(pc->mmio_base, AQSFRC, pc->ctx.aqsfrc);
540 	ehrpwm_write(pc->mmio_base, AQCSFRC, pc->ctx.aqcsfrc);
541 	ehrpwm_write(pc->mmio_base, TBCTL, pc->ctx.tbctl);
542 }
543 
544 static int ehrpwm_pwm_suspend(struct device *dev)
545 {
546 	struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
547 	unsigned int i;
548 
549 	ehrpwm_pwm_save_context(pc);
550 
551 	for (i = 0; i < pc->chip.npwm; i++) {
552 		struct pwm_device *pwm = &pc->chip.pwms[i];
553 
554 		if (!pwm_is_enabled(pwm))
555 			continue;
556 
557 		/* Disable explicitly if PWM is running */
558 		pm_runtime_put_sync(dev);
559 	}
560 
561 	return 0;
562 }
563 
564 static int ehrpwm_pwm_resume(struct device *dev)
565 {
566 	struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
567 	unsigned int i;
568 
569 	for (i = 0; i < pc->chip.npwm; i++) {
570 		struct pwm_device *pwm = &pc->chip.pwms[i];
571 
572 		if (!pwm_is_enabled(pwm))
573 			continue;
574 
575 		/* Enable explicitly if PWM was running */
576 		pm_runtime_get_sync(dev);
577 	}
578 
579 	ehrpwm_pwm_restore_context(pc);
580 
581 	return 0;
582 }
583 #endif
584 
585 static SIMPLE_DEV_PM_OPS(ehrpwm_pwm_pm_ops, ehrpwm_pwm_suspend,
586 			 ehrpwm_pwm_resume);
587 
588 static struct platform_driver ehrpwm_pwm_driver = {
589 	.driver = {
590 		.name = "ehrpwm",
591 		.of_match_table = ehrpwm_of_match,
592 		.pm = &ehrpwm_pwm_pm_ops,
593 	},
594 	.probe = ehrpwm_pwm_probe,
595 	.remove = ehrpwm_pwm_remove,
596 };
597 module_platform_driver(ehrpwm_pwm_driver);
598 
599 MODULE_DESCRIPTION("EHRPWM PWM driver");
600 MODULE_AUTHOR("Texas Instruments");
601 MODULE_LICENSE("GPL");
602