xref: /linux/drivers/pwm/pwm-tiehrpwm.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
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.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 	unsigned long clk_rate;
109 	void __iomem *mmio_base;
110 	unsigned long period_cycles[NUM_PWM_CHANNEL];
111 	enum pwm_polarity polarity[NUM_PWM_CHANNEL];
112 	struct clk *tbclk;
113 	struct ehrpwm_context ctx;
114 };
115 
116 static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
117 {
118 	return pwmchip_get_drvdata(chip);
119 }
120 
121 static inline u16 ehrpwm_read(void __iomem *base, unsigned int offset)
122 {
123 	return readw(base + offset);
124 }
125 
126 static inline void ehrpwm_write(void __iomem *base, unsigned int offset,
127 				u16 value)
128 {
129 	writew(value, base + offset);
130 }
131 
132 static void ehrpwm_modify(void __iomem *base, unsigned int offset, u16 mask,
133 			  u16 value)
134 {
135 	unsigned short val;
136 
137 	val = readw(base + offset);
138 	val &= ~mask;
139 	val |= value & mask;
140 	writew(val, base + offset);
141 }
142 
143 /**
144  * set_prescale_div -	Set up the prescaler divider function
145  * @rqst_prescaler:	prescaler value min
146  * @prescale_div:	prescaler value set
147  * @tb_clk_div:		Time Base Control prescaler bits
148  */
149 static int set_prescale_div(unsigned long rqst_prescaler, u16 *prescale_div,
150 			    u16 *tb_clk_div)
151 {
152 	unsigned int clkdiv, hspclkdiv;
153 
154 	for (clkdiv = 0; clkdiv <= CLKDIV_MAX; clkdiv++) {
155 		for (hspclkdiv = 0; hspclkdiv <= HSPCLKDIV_MAX; hspclkdiv++) {
156 			/*
157 			 * calculations for prescaler value :
158 			 * prescale_div = HSPCLKDIVIDER * CLKDIVIDER.
159 			 * HSPCLKDIVIDER =  2 ** hspclkdiv
160 			 * CLKDIVIDER = (1),		if clkdiv == 0 *OR*
161 			 *		(2 * clkdiv),	if clkdiv != 0
162 			 *
163 			 * Configure prescale_div value such that period
164 			 * register value is less than 65535.
165 			 */
166 
167 			*prescale_div = (1 << clkdiv) *
168 					(hspclkdiv ? (hspclkdiv * 2) : 1);
169 			if (*prescale_div > rqst_prescaler) {
170 				*tb_clk_div = (clkdiv << TBCTL_CLKDIV_SHIFT) |
171 					(hspclkdiv << TBCTL_HSPCLKDIV_SHIFT);
172 				return 0;
173 			}
174 		}
175 	}
176 
177 	return 1;
178 }
179 
180 static void configure_polarity(struct ehrpwm_pwm_chip *pc, int chan)
181 {
182 	u16 aqctl_val, aqctl_mask;
183 	unsigned int aqctl_reg;
184 
185 	/*
186 	 * Configure PWM output to HIGH/LOW level on counter
187 	 * reaches compare register value and LOW/HIGH level
188 	 * on counter value reaches period register value and
189 	 * zero value on counter
190 	 */
191 	if (chan == 1) {
192 		aqctl_reg = AQCTLB;
193 		aqctl_mask = AQCTL_CBU_MASK;
194 
195 		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
196 			aqctl_val = AQCTL_CHANB_POLINVERSED;
197 		else
198 			aqctl_val = AQCTL_CHANB_POLNORMAL;
199 	} else {
200 		aqctl_reg = AQCTLA;
201 		aqctl_mask = AQCTL_CAU_MASK;
202 
203 		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
204 			aqctl_val = AQCTL_CHANA_POLINVERSED;
205 		else
206 			aqctl_val = AQCTL_CHANA_POLNORMAL;
207 	}
208 
209 	aqctl_mask |= AQCTL_PRD_MASK | AQCTL_ZRO_MASK;
210 	ehrpwm_modify(pc->mmio_base, aqctl_reg, aqctl_mask, aqctl_val);
211 }
212 
213 /*
214  * period_ns = 10^9 * (ps_divval * period_cycles) / PWM_CLK_RATE
215  * duty_ns   = 10^9 * (ps_divval * duty_cycles) / PWM_CLK_RATE
216  */
217 static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
218 			     u64 duty_ns, u64 period_ns)
219 {
220 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
221 	u32 period_cycles, duty_cycles;
222 	u16 ps_divval, tb_divval;
223 	unsigned int i, cmp_reg;
224 	unsigned long long c;
225 
226 	if (period_ns > NSEC_PER_SEC)
227 		return -ERANGE;
228 
229 	c = pc->clk_rate;
230 	c = c * period_ns;
231 	do_div(c, NSEC_PER_SEC);
232 	period_cycles = (unsigned long)c;
233 
234 	if (period_cycles < 1) {
235 		period_cycles = 1;
236 		duty_cycles = 1;
237 	} else {
238 		c = pc->clk_rate;
239 		c = c * duty_ns;
240 		do_div(c, NSEC_PER_SEC);
241 		duty_cycles = (unsigned long)c;
242 	}
243 
244 	/*
245 	 * Period values should be same for multiple PWM channels as IP uses
246 	 * same period register for multiple channels.
247 	 */
248 	for (i = 0; i < NUM_PWM_CHANNEL; i++) {
249 		if (pc->period_cycles[i] &&
250 				(pc->period_cycles[i] != period_cycles)) {
251 			/*
252 			 * Allow channel to reconfigure period if no other
253 			 * channels being configured.
254 			 */
255 			if (i == pwm->hwpwm)
256 				continue;
257 
258 			dev_err(pwmchip_parent(chip),
259 				"period value conflicts with channel %u\n",
260 				i);
261 			return -EINVAL;
262 		}
263 	}
264 
265 	pc->period_cycles[pwm->hwpwm] = period_cycles;
266 
267 	/* Configure clock prescaler to support Low frequency PWM wave */
268 	if (set_prescale_div(period_cycles/PERIOD_MAX, &ps_divval,
269 			     &tb_divval)) {
270 		dev_err(pwmchip_parent(chip), "Unsupported values\n");
271 		return -EINVAL;
272 	}
273 
274 	pm_runtime_get_sync(pwmchip_parent(chip));
275 
276 	/* Update clock prescaler values */
277 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CLKDIV_MASK, tb_divval);
278 
279 	/* Update period & duty cycle with presacler division */
280 	period_cycles = period_cycles / ps_divval;
281 	duty_cycles = duty_cycles / ps_divval;
282 
283 	/* Configure shadow loading on Period register */
284 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_PRDLD_MASK, TBCTL_PRDLD_SHDW);
285 
286 	ehrpwm_write(pc->mmio_base, TBPRD, period_cycles);
287 
288 	/* Configure ehrpwm counter for up-count mode */
289 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CTRMODE_MASK,
290 		      TBCTL_CTRMODE_UP);
291 
292 	if (pwm->hwpwm == 1)
293 		/* Channel 1 configured with compare B register */
294 		cmp_reg = CMPB;
295 	else
296 		/* Channel 0 configured with compare A register */
297 		cmp_reg = CMPA;
298 
299 	ehrpwm_write(pc->mmio_base, cmp_reg, duty_cycles);
300 
301 	pm_runtime_put_sync(pwmchip_parent(chip));
302 
303 	return 0;
304 }
305 
306 static int ehrpwm_pwm_set_polarity(struct pwm_chip *chip,
307 				   struct pwm_device *pwm,
308 				   enum pwm_polarity polarity)
309 {
310 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
311 
312 	/* Configuration of polarity in hardware delayed, do at enable */
313 	pc->polarity[pwm->hwpwm] = polarity;
314 
315 	return 0;
316 }
317 
318 static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
319 {
320 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
321 	u16 aqcsfrc_val, aqcsfrc_mask;
322 	int ret;
323 
324 	/* Leave clock enabled on enabling PWM */
325 	pm_runtime_get_sync(pwmchip_parent(chip));
326 
327 	/* Disabling Action Qualifier on PWM output */
328 	if (pwm->hwpwm) {
329 		aqcsfrc_val = AQCSFRC_CSFB_FRCDIS;
330 		aqcsfrc_mask = AQCSFRC_CSFB_MASK;
331 	} else {
332 		aqcsfrc_val = AQCSFRC_CSFA_FRCDIS;
333 		aqcsfrc_mask = AQCSFRC_CSFA_MASK;
334 	}
335 
336 	/* Changes to shadow mode */
337 	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
338 		      AQSFRC_RLDCSF_ZRO);
339 
340 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
341 
342 	/* Channels polarity can be configured from action qualifier module */
343 	configure_polarity(pc, pwm->hwpwm);
344 
345 	/* Enable TBCLK */
346 	ret = clk_enable(pc->tbclk);
347 	if (ret) {
348 		dev_err(pwmchip_parent(chip), "Failed to enable TBCLK for %s: %d\n",
349 			dev_name(pwmchip_parent(chip)), ret);
350 		return ret;
351 	}
352 
353 	return 0;
354 }
355 
356 static void ehrpwm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
357 {
358 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
359 	u16 aqcsfrc_val, aqcsfrc_mask;
360 
361 	/* Action Qualifier puts PWM output low forcefully */
362 	if (pwm->hwpwm) {
363 		aqcsfrc_val = AQCSFRC_CSFB_FRCLOW;
364 		aqcsfrc_mask = AQCSFRC_CSFB_MASK;
365 	} else {
366 		aqcsfrc_val = AQCSFRC_CSFA_FRCLOW;
367 		aqcsfrc_mask = AQCSFRC_CSFA_MASK;
368 	}
369 
370 	/* Update shadow register first before modifying active register */
371 	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
372 		      AQSFRC_RLDCSF_ZRO);
373 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
374 	/*
375 	 * Changes to immediate action on Action Qualifier. This puts
376 	 * Action Qualifier control on PWM output from next TBCLK
377 	 */
378 	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
379 		      AQSFRC_RLDCSF_IMDT);
380 
381 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
382 
383 	/* Disabling TBCLK on PWM disable */
384 	clk_disable(pc->tbclk);
385 
386 	/* Disable clock on PWM disable */
387 	pm_runtime_put_sync(pwmchip_parent(chip));
388 }
389 
390 static void ehrpwm_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
391 {
392 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
393 
394 	if (pwm_is_enabled(pwm)) {
395 		dev_warn(pwmchip_parent(chip), "Removing PWM device without disabling\n");
396 		pm_runtime_put_sync(pwmchip_parent(chip));
397 	}
398 
399 	/* set period value to zero on free */
400 	pc->period_cycles[pwm->hwpwm] = 0;
401 }
402 
403 static int ehrpwm_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
404 			    const struct pwm_state *state)
405 {
406 	int err;
407 	bool enabled = pwm->state.enabled;
408 
409 	if (state->polarity != pwm->state.polarity) {
410 		if (enabled) {
411 			ehrpwm_pwm_disable(chip, pwm);
412 			enabled = false;
413 		}
414 
415 		err = ehrpwm_pwm_set_polarity(chip, pwm, state->polarity);
416 		if (err)
417 			return err;
418 	}
419 
420 	if (!state->enabled) {
421 		if (enabled)
422 			ehrpwm_pwm_disable(chip, pwm);
423 		return 0;
424 	}
425 
426 	err = ehrpwm_pwm_config(chip, pwm, state->duty_cycle, state->period);
427 	if (err)
428 		return err;
429 
430 	if (!enabled)
431 		err = ehrpwm_pwm_enable(chip, pwm);
432 
433 	return err;
434 }
435 
436 static const struct pwm_ops ehrpwm_pwm_ops = {
437 	.free = ehrpwm_pwm_free,
438 	.apply = ehrpwm_pwm_apply,
439 };
440 
441 static const struct of_device_id ehrpwm_of_match[] = {
442 	{ .compatible = "ti,am3352-ehrpwm" },
443 	{ .compatible = "ti,am33xx-ehrpwm" },
444 	{},
445 };
446 MODULE_DEVICE_TABLE(of, ehrpwm_of_match);
447 
448 static int ehrpwm_pwm_probe(struct platform_device *pdev)
449 {
450 	struct device_node *np = pdev->dev.of_node;
451 	struct ehrpwm_pwm_chip *pc;
452 	struct pwm_chip *chip;
453 	struct clk *clk;
454 	int ret;
455 
456 	chip = devm_pwmchip_alloc(&pdev->dev, NUM_PWM_CHANNEL, sizeof(*pc));
457 	if (IS_ERR(chip))
458 		return PTR_ERR(chip);
459 	pc = to_ehrpwm_pwm_chip(chip);
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 	chip->ops = &ehrpwm_pwm_ops;
479 
480 	pc->mmio_base = devm_platform_ioremap_resource(pdev, 0);
481 	if (IS_ERR(pc->mmio_base))
482 		return PTR_ERR(pc->mmio_base);
483 
484 	/* Acquire tbclk for Time Base EHRPWM submodule */
485 	pc->tbclk = devm_clk_get(&pdev->dev, "tbclk");
486 	if (IS_ERR(pc->tbclk))
487 		return dev_err_probe(&pdev->dev, PTR_ERR(pc->tbclk), "Failed to get tbclk\n");
488 
489 	ret = clk_prepare(pc->tbclk);
490 	if (ret < 0) {
491 		dev_err(&pdev->dev, "clk_prepare() failed: %d\n", ret);
492 		return ret;
493 	}
494 
495 	ret = pwmchip_add(chip);
496 	if (ret < 0) {
497 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
498 		goto err_clk_unprepare;
499 	}
500 
501 	platform_set_drvdata(pdev, chip);
502 	pm_runtime_enable(&pdev->dev);
503 
504 	return 0;
505 
506 err_clk_unprepare:
507 	clk_unprepare(pc->tbclk);
508 
509 	return ret;
510 }
511 
512 static void ehrpwm_pwm_remove(struct platform_device *pdev)
513 {
514 	struct pwm_chip *chip = platform_get_drvdata(pdev);
515 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
516 
517 	pwmchip_remove(chip);
518 
519 	clk_unprepare(pc->tbclk);
520 
521 	pm_runtime_disable(&pdev->dev);
522 }
523 
524 static void ehrpwm_pwm_save_context(struct pwm_chip *chip)
525 {
526 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
527 
528 	pm_runtime_get_sync(pwmchip_parent(chip));
529 
530 	pc->ctx.tbctl = ehrpwm_read(pc->mmio_base, TBCTL);
531 	pc->ctx.tbprd = ehrpwm_read(pc->mmio_base, TBPRD);
532 	pc->ctx.cmpa = ehrpwm_read(pc->mmio_base, CMPA);
533 	pc->ctx.cmpb = ehrpwm_read(pc->mmio_base, CMPB);
534 	pc->ctx.aqctla = ehrpwm_read(pc->mmio_base, AQCTLA);
535 	pc->ctx.aqctlb = ehrpwm_read(pc->mmio_base, AQCTLB);
536 	pc->ctx.aqsfrc = ehrpwm_read(pc->mmio_base, AQSFRC);
537 	pc->ctx.aqcsfrc = ehrpwm_read(pc->mmio_base, AQCSFRC);
538 
539 	pm_runtime_put_sync(pwmchip_parent(chip));
540 }
541 
542 static void ehrpwm_pwm_restore_context(struct pwm_chip *chip)
543 {
544 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
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 pwm_chip *chip = dev_get_drvdata(dev);
559 	unsigned int i;
560 
561 	ehrpwm_pwm_save_context(chip);
562 
563 	for (i = 0; i < chip->npwm; i++) {
564 		struct pwm_device *pwm = &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 pwm_chip *chip = dev_get_drvdata(dev);
579 	unsigned int i;
580 
581 	for (i = 0; i < chip->npwm; i++) {
582 		struct pwm_device *pwm = &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(chip);
592 
593 	return 0;
594 }
595 
596 static DEFINE_SIMPLE_DEV_PM_OPS(ehrpwm_pwm_pm_ops, ehrpwm_pwm_suspend,
597 				ehrpwm_pwm_resume);
598 
599 static struct platform_driver ehrpwm_pwm_driver = {
600 	.driver = {
601 		.name = "ehrpwm",
602 		.of_match_table = ehrpwm_of_match,
603 		.pm = pm_ptr(&ehrpwm_pwm_pm_ops),
604 	},
605 	.probe = ehrpwm_pwm_probe,
606 	.remove_new = ehrpwm_pwm_remove,
607 };
608 module_platform_driver(ehrpwm_pwm_driver);
609 
610 MODULE_DESCRIPTION("EHRPWM PWM driver");
611 MODULE_AUTHOR("Texas Instruments");
612 MODULE_LICENSE("GPL");
613