xref: /openbmc/linux/drivers/pwm/pwm-tiehrpwm.c (revision e65e175b)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * EHRPWM PWM driver
4  *
5  * Copyright (C) 2012 Texas Instruments, Inc. - https://www.ti.com/
6  */
7 
8 #include <linux/module.h>
9 #include <linux/platform_device.h>
10 #include <linux/pwm.h>
11 #include <linux/io.h>
12 #include <linux/err.h>
13 #include <linux/clk.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/of_device.h>
16 
17 /* EHRPWM registers and bits definitions */
18 
19 /* Time base module registers */
20 #define TBCTL			0x00
21 #define TBPRD			0x0A
22 
23 #define TBCTL_PRDLD_MASK	BIT(3)
24 #define TBCTL_PRDLD_SHDW	0
25 #define TBCTL_PRDLD_IMDT	BIT(3)
26 #define TBCTL_CLKDIV_MASK	(BIT(12) | BIT(11) | BIT(10) | BIT(9) | \
27 				BIT(8) | BIT(7))
28 #define TBCTL_CTRMODE_MASK	(BIT(1) | BIT(0))
29 #define TBCTL_CTRMODE_UP	0
30 #define TBCTL_CTRMODE_DOWN	BIT(0)
31 #define TBCTL_CTRMODE_UPDOWN	BIT(1)
32 #define TBCTL_CTRMODE_FREEZE	(BIT(1) | BIT(0))
33 
34 #define TBCTL_HSPCLKDIV_SHIFT	7
35 #define TBCTL_CLKDIV_SHIFT	10
36 
37 #define CLKDIV_MAX		7
38 #define HSPCLKDIV_MAX		7
39 #define PERIOD_MAX		0xFFFF
40 
41 /* compare module registers */
42 #define CMPA			0x12
43 #define CMPB			0x14
44 
45 /* Action qualifier module registers */
46 #define AQCTLA			0x16
47 #define AQCTLB			0x18
48 #define AQSFRC			0x1A
49 #define AQCSFRC			0x1C
50 
51 #define AQCTL_CBU_MASK		(BIT(9) | BIT(8))
52 #define AQCTL_CBU_FRCLOW	BIT(8)
53 #define AQCTL_CBU_FRCHIGH	BIT(9)
54 #define AQCTL_CBU_FRCTOGGLE	(BIT(9) | BIT(8))
55 #define AQCTL_CAU_MASK		(BIT(5) | BIT(4))
56 #define AQCTL_CAU_FRCLOW	BIT(4)
57 #define AQCTL_CAU_FRCHIGH	BIT(5)
58 #define AQCTL_CAU_FRCTOGGLE	(BIT(5) | BIT(4))
59 #define AQCTL_PRD_MASK		(BIT(3) | BIT(2))
60 #define AQCTL_PRD_FRCLOW	BIT(2)
61 #define AQCTL_PRD_FRCHIGH	BIT(3)
62 #define AQCTL_PRD_FRCTOGGLE	(BIT(3) | BIT(2))
63 #define AQCTL_ZRO_MASK		(BIT(1) | BIT(0))
64 #define AQCTL_ZRO_FRCLOW	BIT(0)
65 #define AQCTL_ZRO_FRCHIGH	BIT(1)
66 #define AQCTL_ZRO_FRCTOGGLE	(BIT(1) | BIT(0))
67 
68 #define AQCTL_CHANA_POLNORMAL	(AQCTL_CAU_FRCLOW | AQCTL_PRD_FRCHIGH | \
69 				AQCTL_ZRO_FRCHIGH)
70 #define AQCTL_CHANA_POLINVERSED	(AQCTL_CAU_FRCHIGH | AQCTL_PRD_FRCLOW | \
71 				AQCTL_ZRO_FRCLOW)
72 #define AQCTL_CHANB_POLNORMAL	(AQCTL_CBU_FRCLOW | AQCTL_PRD_FRCHIGH | \
73 				AQCTL_ZRO_FRCHIGH)
74 #define AQCTL_CHANB_POLINVERSED	(AQCTL_CBU_FRCHIGH | AQCTL_PRD_FRCLOW | \
75 				AQCTL_ZRO_FRCLOW)
76 
77 #define AQSFRC_RLDCSF_MASK	(BIT(7) | BIT(6))
78 #define AQSFRC_RLDCSF_ZRO	0
79 #define AQSFRC_RLDCSF_PRD	BIT(6)
80 #define AQSFRC_RLDCSF_ZROPRD	BIT(7)
81 #define AQSFRC_RLDCSF_IMDT	(BIT(7) | BIT(6))
82 
83 #define AQCSFRC_CSFB_MASK	(BIT(3) | BIT(2))
84 #define AQCSFRC_CSFB_FRCDIS	0
85 #define AQCSFRC_CSFB_FRCLOW	BIT(2)
86 #define AQCSFRC_CSFB_FRCHIGH	BIT(3)
87 #define AQCSFRC_CSFB_DISSWFRC	(BIT(3) | BIT(2))
88 #define AQCSFRC_CSFA_MASK	(BIT(1) | BIT(0))
89 #define AQCSFRC_CSFA_FRCDIS	0
90 #define AQCSFRC_CSFA_FRCLOW	BIT(0)
91 #define AQCSFRC_CSFA_FRCHIGH	BIT(1)
92 #define AQCSFRC_CSFA_DISSWFRC	(BIT(1) | BIT(0))
93 
94 #define NUM_PWM_CHANNEL		2	/* EHRPWM channels */
95 
96 struct ehrpwm_context {
97 	u16 tbctl;
98 	u16 tbprd;
99 	u16 cmpa;
100 	u16 cmpb;
101 	u16 aqctla;
102 	u16 aqctlb;
103 	u16 aqsfrc;
104 	u16 aqcsfrc;
105 };
106 
107 struct ehrpwm_pwm_chip {
108 	struct pwm_chip chip;
109 	unsigned long clk_rate;
110 	void __iomem *mmio_base;
111 	unsigned long period_cycles[NUM_PWM_CHANNEL];
112 	enum pwm_polarity polarity[NUM_PWM_CHANNEL];
113 	struct clk *tbclk;
114 	struct ehrpwm_context ctx;
115 };
116 
117 static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
118 {
119 	return container_of(chip, struct ehrpwm_pwm_chip, chip);
120 }
121 
122 static inline u16 ehrpwm_read(void __iomem *base, unsigned int offset)
123 {
124 	return readw(base + offset);
125 }
126 
127 static inline void ehrpwm_write(void __iomem *base, unsigned int offset,
128 				u16 value)
129 {
130 	writew(value, base + offset);
131 }
132 
133 static void ehrpwm_modify(void __iomem *base, unsigned int offset, u16 mask,
134 			  u16 value)
135 {
136 	unsigned short val;
137 
138 	val = readw(base + offset);
139 	val &= ~mask;
140 	val |= value & mask;
141 	writew(val, base + offset);
142 }
143 
144 /**
145  * set_prescale_div -	Set up the prescaler divider function
146  * @rqst_prescaler:	prescaler value min
147  * @prescale_div:	prescaler value set
148  * @tb_clk_div:		Time Base Control prescaler bits
149  */
150 static int set_prescale_div(unsigned long rqst_prescaler, u16 *prescale_div,
151 			    u16 *tb_clk_div)
152 {
153 	unsigned int clkdiv, hspclkdiv;
154 
155 	for (clkdiv = 0; clkdiv <= CLKDIV_MAX; clkdiv++) {
156 		for (hspclkdiv = 0; hspclkdiv <= HSPCLKDIV_MAX; hspclkdiv++) {
157 			/*
158 			 * calculations for prescaler value :
159 			 * prescale_div = HSPCLKDIVIDER * CLKDIVIDER.
160 			 * HSPCLKDIVIDER =  2 ** hspclkdiv
161 			 * CLKDIVIDER = (1),		if clkdiv == 0 *OR*
162 			 *		(2 * clkdiv),	if clkdiv != 0
163 			 *
164 			 * Configure prescale_div value such that period
165 			 * register value is less than 65535.
166 			 */
167 
168 			*prescale_div = (1 << clkdiv) *
169 					(hspclkdiv ? (hspclkdiv * 2) : 1);
170 			if (*prescale_div > rqst_prescaler) {
171 				*tb_clk_div = (clkdiv << TBCTL_CLKDIV_SHIFT) |
172 					(hspclkdiv << TBCTL_HSPCLKDIV_SHIFT);
173 				return 0;
174 			}
175 		}
176 	}
177 
178 	return 1;
179 }
180 
181 static void configure_polarity(struct ehrpwm_pwm_chip *pc, int chan)
182 {
183 	u16 aqctl_val, aqctl_mask;
184 	unsigned int aqctl_reg;
185 
186 	/*
187 	 * Configure PWM output to HIGH/LOW level on counter
188 	 * reaches compare register value and LOW/HIGH level
189 	 * on counter value reaches period register value and
190 	 * zero value on counter
191 	 */
192 	if (chan == 1) {
193 		aqctl_reg = AQCTLB;
194 		aqctl_mask = AQCTL_CBU_MASK;
195 
196 		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
197 			aqctl_val = AQCTL_CHANB_POLINVERSED;
198 		else
199 			aqctl_val = AQCTL_CHANB_POLNORMAL;
200 	} else {
201 		aqctl_reg = AQCTLA;
202 		aqctl_mask = AQCTL_CAU_MASK;
203 
204 		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
205 			aqctl_val = AQCTL_CHANA_POLINVERSED;
206 		else
207 			aqctl_val = AQCTL_CHANA_POLNORMAL;
208 	}
209 
210 	aqctl_mask |= AQCTL_PRD_MASK | AQCTL_ZRO_MASK;
211 	ehrpwm_modify(pc->mmio_base, aqctl_reg, aqctl_mask, aqctl_val);
212 }
213 
214 /*
215  * period_ns = 10^9 * (ps_divval * period_cycles) / PWM_CLK_RATE
216  * duty_ns   = 10^9 * (ps_divval * duty_cycles) / PWM_CLK_RATE
217  */
218 static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
219 			     u64 duty_ns, u64 period_ns)
220 {
221 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
222 	u32 period_cycles, duty_cycles;
223 	u16 ps_divval, tb_divval;
224 	unsigned int i, cmp_reg;
225 	unsigned long long c;
226 
227 	if (period_ns > NSEC_PER_SEC)
228 		return -ERANGE;
229 
230 	c = pc->clk_rate;
231 	c = c * period_ns;
232 	do_div(c, NSEC_PER_SEC);
233 	period_cycles = (unsigned long)c;
234 
235 	if (period_cycles < 1) {
236 		period_cycles = 1;
237 		duty_cycles = 1;
238 	} else {
239 		c = pc->clk_rate;
240 		c = c * duty_ns;
241 		do_div(c, NSEC_PER_SEC);
242 		duty_cycles = (unsigned long)c;
243 	}
244 
245 	/*
246 	 * Period values should be same for multiple PWM channels as IP uses
247 	 * same period register for multiple channels.
248 	 */
249 	for (i = 0; i < NUM_PWM_CHANNEL; i++) {
250 		if (pc->period_cycles[i] &&
251 				(pc->period_cycles[i] != period_cycles)) {
252 			/*
253 			 * Allow channel to reconfigure period if no other
254 			 * channels being configured.
255 			 */
256 			if (i == pwm->hwpwm)
257 				continue;
258 
259 			dev_err(chip->dev,
260 				"period value conflicts with channel %u\n",
261 				i);
262 			return -EINVAL;
263 		}
264 	}
265 
266 	pc->period_cycles[pwm->hwpwm] = period_cycles;
267 
268 	/* Configure clock prescaler to support Low frequency PWM wave */
269 	if (set_prescale_div(period_cycles/PERIOD_MAX, &ps_divval,
270 			     &tb_divval)) {
271 		dev_err(chip->dev, "Unsupported values\n");
272 		return -EINVAL;
273 	}
274 
275 	pm_runtime_get_sync(chip->dev);
276 
277 	/* Update clock prescaler values */
278 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CLKDIV_MASK, tb_divval);
279 
280 	/* Update period & duty cycle with presacler division */
281 	period_cycles = period_cycles / ps_divval;
282 	duty_cycles = duty_cycles / ps_divval;
283 
284 	/* Configure shadow loading on Period register */
285 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_PRDLD_MASK, TBCTL_PRDLD_SHDW);
286 
287 	ehrpwm_write(pc->mmio_base, TBPRD, period_cycles);
288 
289 	/* Configure ehrpwm counter for up-count mode */
290 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CTRMODE_MASK,
291 		      TBCTL_CTRMODE_UP);
292 
293 	if (pwm->hwpwm == 1)
294 		/* Channel 1 configured with compare B register */
295 		cmp_reg = CMPB;
296 	else
297 		/* Channel 0 configured with compare A register */
298 		cmp_reg = CMPA;
299 
300 	ehrpwm_write(pc->mmio_base, cmp_reg, duty_cycles);
301 
302 	pm_runtime_put_sync(chip->dev);
303 
304 	return 0;
305 }
306 
307 static int ehrpwm_pwm_set_polarity(struct pwm_chip *chip,
308 				   struct pwm_device *pwm,
309 				   enum pwm_polarity polarity)
310 {
311 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
312 
313 	/* Configuration of polarity in hardware delayed, do at enable */
314 	pc->polarity[pwm->hwpwm] = polarity;
315 
316 	return 0;
317 }
318 
319 static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
320 {
321 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
322 	u16 aqcsfrc_val, aqcsfrc_mask;
323 	int ret;
324 
325 	/* Leave clock enabled on enabling PWM */
326 	pm_runtime_get_sync(chip->dev);
327 
328 	/* Disabling Action Qualifier on PWM output */
329 	if (pwm->hwpwm) {
330 		aqcsfrc_val = AQCSFRC_CSFB_FRCDIS;
331 		aqcsfrc_mask = AQCSFRC_CSFB_MASK;
332 	} else {
333 		aqcsfrc_val = AQCSFRC_CSFA_FRCDIS;
334 		aqcsfrc_mask = AQCSFRC_CSFA_MASK;
335 	}
336 
337 	/* Changes to shadow mode */
338 	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
339 		      AQSFRC_RLDCSF_ZRO);
340 
341 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
342 
343 	/* Channels polarity can be configured from action qualifier module */
344 	configure_polarity(pc, pwm->hwpwm);
345 
346 	/* Enable TBCLK */
347 	ret = clk_enable(pc->tbclk);
348 	if (ret) {
349 		dev_err(chip->dev, "Failed to enable TBCLK for %s: %d\n",
350 			dev_name(pc->chip.dev), ret);
351 		return ret;
352 	}
353 
354 	return 0;
355 }
356 
357 static void ehrpwm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
358 {
359 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
360 	u16 aqcsfrc_val, aqcsfrc_mask;
361 
362 	/* Action Qualifier puts PWM output low forcefully */
363 	if (pwm->hwpwm) {
364 		aqcsfrc_val = AQCSFRC_CSFB_FRCLOW;
365 		aqcsfrc_mask = AQCSFRC_CSFB_MASK;
366 	} else {
367 		aqcsfrc_val = AQCSFRC_CSFA_FRCLOW;
368 		aqcsfrc_mask = AQCSFRC_CSFA_MASK;
369 	}
370 
371 	/* Update shadow register first before modifying active register */
372 	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
373 		      AQSFRC_RLDCSF_ZRO);
374 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
375 	/*
376 	 * Changes to immediate action on Action Qualifier. This puts
377 	 * Action Qualifier control on PWM output from next TBCLK
378 	 */
379 	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
380 		      AQSFRC_RLDCSF_IMDT);
381 
382 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
383 
384 	/* Disabling TBCLK on PWM disable */
385 	clk_disable(pc->tbclk);
386 
387 	/* Disable clock on PWM disable */
388 	pm_runtime_put_sync(chip->dev);
389 }
390 
391 static void ehrpwm_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
392 {
393 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
394 
395 	if (pwm_is_enabled(pwm)) {
396 		dev_warn(chip->dev, "Removing PWM device without disabling\n");
397 		pm_runtime_put_sync(chip->dev);
398 	}
399 
400 	/* set period value to zero on free */
401 	pc->period_cycles[pwm->hwpwm] = 0;
402 }
403 
404 static int ehrpwm_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
405 			    const struct pwm_state *state)
406 {
407 	int err;
408 	bool enabled = pwm->state.enabled;
409 
410 	if (state->polarity != pwm->state.polarity) {
411 		if (enabled) {
412 			ehrpwm_pwm_disable(chip, pwm);
413 			enabled = false;
414 		}
415 
416 		err = ehrpwm_pwm_set_polarity(chip, pwm, state->polarity);
417 		if (err)
418 			return err;
419 	}
420 
421 	if (!state->enabled) {
422 		if (enabled)
423 			ehrpwm_pwm_disable(chip, pwm);
424 		return 0;
425 	}
426 
427 	err = ehrpwm_pwm_config(chip, pwm, state->duty_cycle, state->period);
428 	if (err)
429 		return err;
430 
431 	if (!enabled)
432 		err = ehrpwm_pwm_enable(chip, pwm);
433 
434 	return err;
435 }
436 
437 static const struct pwm_ops ehrpwm_pwm_ops = {
438 	.free = ehrpwm_pwm_free,
439 	.apply = ehrpwm_pwm_apply,
440 	.owner = THIS_MODULE,
441 };
442 
443 static const struct of_device_id ehrpwm_of_match[] = {
444 	{ .compatible = "ti,am3352-ehrpwm" },
445 	{ .compatible = "ti,am33xx-ehrpwm" },
446 	{},
447 };
448 MODULE_DEVICE_TABLE(of, ehrpwm_of_match);
449 
450 static int ehrpwm_pwm_probe(struct platform_device *pdev)
451 {
452 	struct device_node *np = pdev->dev.of_node;
453 	struct ehrpwm_pwm_chip *pc;
454 	struct clk *clk;
455 	int ret;
456 
457 	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
458 	if (!pc)
459 		return -ENOMEM;
460 
461 	clk = devm_clk_get(&pdev->dev, "fck");
462 	if (IS_ERR(clk)) {
463 		if (of_device_is_compatible(np, "ti,am33xx-ecap")) {
464 			dev_warn(&pdev->dev, "Binding is obsolete.\n");
465 			clk = devm_clk_get(pdev->dev.parent, "fck");
466 		}
467 	}
468 
469 	if (IS_ERR(clk))
470 		return dev_err_probe(&pdev->dev, PTR_ERR(clk), "Failed to get fck\n");
471 
472 	pc->clk_rate = clk_get_rate(clk);
473 	if (!pc->clk_rate) {
474 		dev_err(&pdev->dev, "failed to get clock rate\n");
475 		return -EINVAL;
476 	}
477 
478 	pc->chip.dev = &pdev->dev;
479 	pc->chip.ops = &ehrpwm_pwm_ops;
480 	pc->chip.npwm = NUM_PWM_CHANNEL;
481 
482 	pc->mmio_base = devm_platform_ioremap_resource(pdev, 0);
483 	if (IS_ERR(pc->mmio_base))
484 		return PTR_ERR(pc->mmio_base);
485 
486 	/* Acquire tbclk for Time Base EHRPWM submodule */
487 	pc->tbclk = devm_clk_get(&pdev->dev, "tbclk");
488 	if (IS_ERR(pc->tbclk))
489 		return dev_err_probe(&pdev->dev, PTR_ERR(pc->tbclk), "Failed to get tbclk\n");
490 
491 	ret = clk_prepare(pc->tbclk);
492 	if (ret < 0) {
493 		dev_err(&pdev->dev, "clk_prepare() failed: %d\n", ret);
494 		return ret;
495 	}
496 
497 	ret = pwmchip_add(&pc->chip);
498 	if (ret < 0) {
499 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
500 		goto err_clk_unprepare;
501 	}
502 
503 	platform_set_drvdata(pdev, pc);
504 	pm_runtime_enable(&pdev->dev);
505 
506 	return 0;
507 
508 err_clk_unprepare:
509 	clk_unprepare(pc->tbclk);
510 
511 	return ret;
512 }
513 
514 static int ehrpwm_pwm_remove(struct platform_device *pdev)
515 {
516 	struct ehrpwm_pwm_chip *pc = platform_get_drvdata(pdev);
517 
518 	pwmchip_remove(&pc->chip);
519 
520 	clk_unprepare(pc->tbclk);
521 
522 	pm_runtime_disable(&pdev->dev);
523 
524 	return 0;
525 }
526 
527 #ifdef CONFIG_PM_SLEEP
528 static void ehrpwm_pwm_save_context(struct ehrpwm_pwm_chip *pc)
529 {
530 	pm_runtime_get_sync(pc->chip.dev);
531 
532 	pc->ctx.tbctl = ehrpwm_read(pc->mmio_base, TBCTL);
533 	pc->ctx.tbprd = ehrpwm_read(pc->mmio_base, TBPRD);
534 	pc->ctx.cmpa = ehrpwm_read(pc->mmio_base, CMPA);
535 	pc->ctx.cmpb = ehrpwm_read(pc->mmio_base, CMPB);
536 	pc->ctx.aqctla = ehrpwm_read(pc->mmio_base, AQCTLA);
537 	pc->ctx.aqctlb = ehrpwm_read(pc->mmio_base, AQCTLB);
538 	pc->ctx.aqsfrc = ehrpwm_read(pc->mmio_base, AQSFRC);
539 	pc->ctx.aqcsfrc = ehrpwm_read(pc->mmio_base, AQCSFRC);
540 
541 	pm_runtime_put_sync(pc->chip.dev);
542 }
543 
544 static void ehrpwm_pwm_restore_context(struct ehrpwm_pwm_chip *pc)
545 {
546 	ehrpwm_write(pc->mmio_base, TBPRD, pc->ctx.tbprd);
547 	ehrpwm_write(pc->mmio_base, CMPA, pc->ctx.cmpa);
548 	ehrpwm_write(pc->mmio_base, CMPB, pc->ctx.cmpb);
549 	ehrpwm_write(pc->mmio_base, AQCTLA, pc->ctx.aqctla);
550 	ehrpwm_write(pc->mmio_base, AQCTLB, pc->ctx.aqctlb);
551 	ehrpwm_write(pc->mmio_base, AQSFRC, pc->ctx.aqsfrc);
552 	ehrpwm_write(pc->mmio_base, AQCSFRC, pc->ctx.aqcsfrc);
553 	ehrpwm_write(pc->mmio_base, TBCTL, pc->ctx.tbctl);
554 }
555 
556 static int ehrpwm_pwm_suspend(struct device *dev)
557 {
558 	struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
559 	unsigned int i;
560 
561 	ehrpwm_pwm_save_context(pc);
562 
563 	for (i = 0; i < pc->chip.npwm; i++) {
564 		struct pwm_device *pwm = &pc->chip.pwms[i];
565 
566 		if (!pwm_is_enabled(pwm))
567 			continue;
568 
569 		/* Disable explicitly if PWM is running */
570 		pm_runtime_put_sync(dev);
571 	}
572 
573 	return 0;
574 }
575 
576 static int ehrpwm_pwm_resume(struct device *dev)
577 {
578 	struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
579 	unsigned int i;
580 
581 	for (i = 0; i < pc->chip.npwm; i++) {
582 		struct pwm_device *pwm = &pc->chip.pwms[i];
583 
584 		if (!pwm_is_enabled(pwm))
585 			continue;
586 
587 		/* Enable explicitly if PWM was running */
588 		pm_runtime_get_sync(dev);
589 	}
590 
591 	ehrpwm_pwm_restore_context(pc);
592 
593 	return 0;
594 }
595 #endif
596 
597 static SIMPLE_DEV_PM_OPS(ehrpwm_pwm_pm_ops, ehrpwm_pwm_suspend,
598 			 ehrpwm_pwm_resume);
599 
600 static struct platform_driver ehrpwm_pwm_driver = {
601 	.driver = {
602 		.name = "ehrpwm",
603 		.of_match_table = ehrpwm_of_match,
604 		.pm = &ehrpwm_pwm_pm_ops,
605 	},
606 	.probe = ehrpwm_pwm_probe,
607 	.remove = ehrpwm_pwm_remove,
608 };
609 module_platform_driver(ehrpwm_pwm_driver);
610 
611 MODULE_DESCRIPTION("EHRPWM PWM driver");
612 MODULE_AUTHOR("Texas Instruments");
613 MODULE_LICENSE("GPL");
614