xref: /openbmc/linux/drivers/pwm/pwm-tiehrpwm.c (revision 5a244f48)
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_RUN_MASK		(BIT(15) | BIT(14))
37 #define TBCTL_STOP_NEXT		0
38 #define TBCTL_STOP_ON_CYCLE	BIT(14)
39 #define TBCTL_FREE_RUN		(BIT(15) | BIT(14))
40 #define TBCTL_PRDLD_MASK	BIT(3)
41 #define TBCTL_PRDLD_SHDW	0
42 #define TBCTL_PRDLD_IMDT	BIT(3)
43 #define TBCTL_CLKDIV_MASK	(BIT(12) | BIT(11) | BIT(10) | BIT(9) | \
44 				BIT(8) | BIT(7))
45 #define TBCTL_CTRMODE_MASK	(BIT(1) | BIT(0))
46 #define TBCTL_CTRMODE_UP	0
47 #define TBCTL_CTRMODE_DOWN	BIT(0)
48 #define TBCTL_CTRMODE_UPDOWN	BIT(1)
49 #define TBCTL_CTRMODE_FREEZE	(BIT(1) | BIT(0))
50 
51 #define TBCTL_HSPCLKDIV_SHIFT	7
52 #define TBCTL_CLKDIV_SHIFT	10
53 
54 #define CLKDIV_MAX		7
55 #define HSPCLKDIV_MAX		7
56 #define PERIOD_MAX		0xFFFF
57 
58 /* compare module registers */
59 #define CMPA			0x12
60 #define CMPB			0x14
61 
62 /* Action qualifier module registers */
63 #define AQCTLA			0x16
64 #define AQCTLB			0x18
65 #define AQSFRC			0x1A
66 #define AQCSFRC			0x1C
67 
68 #define AQCTL_CBU_MASK		(BIT(9) | BIT(8))
69 #define AQCTL_CBU_FRCLOW	BIT(8)
70 #define AQCTL_CBU_FRCHIGH	BIT(9)
71 #define AQCTL_CBU_FRCTOGGLE	(BIT(9) | BIT(8))
72 #define AQCTL_CAU_MASK		(BIT(5) | BIT(4))
73 #define AQCTL_CAU_FRCLOW	BIT(4)
74 #define AQCTL_CAU_FRCHIGH	BIT(5)
75 #define AQCTL_CAU_FRCTOGGLE	(BIT(5) | BIT(4))
76 #define AQCTL_PRD_MASK		(BIT(3) | BIT(2))
77 #define AQCTL_PRD_FRCLOW	BIT(2)
78 #define AQCTL_PRD_FRCHIGH	BIT(3)
79 #define AQCTL_PRD_FRCTOGGLE	(BIT(3) | BIT(2))
80 #define AQCTL_ZRO_MASK		(BIT(1) | BIT(0))
81 #define AQCTL_ZRO_FRCLOW	BIT(0)
82 #define AQCTL_ZRO_FRCHIGH	BIT(1)
83 #define AQCTL_ZRO_FRCTOGGLE	(BIT(1) | BIT(0))
84 
85 #define AQCTL_CHANA_POLNORMAL	(AQCTL_CAU_FRCLOW | AQCTL_PRD_FRCHIGH | \
86 				AQCTL_ZRO_FRCHIGH)
87 #define AQCTL_CHANA_POLINVERSED	(AQCTL_CAU_FRCHIGH | AQCTL_PRD_FRCLOW | \
88 				AQCTL_ZRO_FRCLOW)
89 #define AQCTL_CHANB_POLNORMAL	(AQCTL_CBU_FRCLOW | AQCTL_PRD_FRCHIGH | \
90 				AQCTL_ZRO_FRCHIGH)
91 #define AQCTL_CHANB_POLINVERSED	(AQCTL_CBU_FRCHIGH | AQCTL_PRD_FRCLOW | \
92 				AQCTL_ZRO_FRCLOW)
93 
94 #define AQSFRC_RLDCSF_MASK	(BIT(7) | BIT(6))
95 #define AQSFRC_RLDCSF_ZRO	0
96 #define AQSFRC_RLDCSF_PRD	BIT(6)
97 #define AQSFRC_RLDCSF_ZROPRD	BIT(7)
98 #define AQSFRC_RLDCSF_IMDT	(BIT(7) | BIT(6))
99 
100 #define AQCSFRC_CSFB_MASK	(BIT(3) | BIT(2))
101 #define AQCSFRC_CSFB_FRCDIS	0
102 #define AQCSFRC_CSFB_FRCLOW	BIT(2)
103 #define AQCSFRC_CSFB_FRCHIGH	BIT(3)
104 #define AQCSFRC_CSFB_DISSWFRC	(BIT(3) | BIT(2))
105 #define AQCSFRC_CSFA_MASK	(BIT(1) | BIT(0))
106 #define AQCSFRC_CSFA_FRCDIS	0
107 #define AQCSFRC_CSFA_FRCLOW	BIT(0)
108 #define AQCSFRC_CSFA_FRCHIGH	BIT(1)
109 #define AQCSFRC_CSFA_DISSWFRC	(BIT(1) | BIT(0))
110 
111 #define NUM_PWM_CHANNEL		2	/* EHRPWM channels */
112 
113 struct ehrpwm_context {
114 	u16 tbctl;
115 	u16 tbprd;
116 	u16 cmpa;
117 	u16 cmpb;
118 	u16 aqctla;
119 	u16 aqctlb;
120 	u16 aqsfrc;
121 	u16 aqcsfrc;
122 };
123 
124 struct ehrpwm_pwm_chip {
125 	struct pwm_chip chip;
126 	unsigned long clk_rate;
127 	void __iomem *mmio_base;
128 	unsigned long period_cycles[NUM_PWM_CHANNEL];
129 	enum pwm_polarity polarity[NUM_PWM_CHANNEL];
130 	struct clk *tbclk;
131 	struct ehrpwm_context ctx;
132 };
133 
134 static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
135 {
136 	return container_of(chip, struct ehrpwm_pwm_chip, chip);
137 }
138 
139 static inline u16 ehrpwm_read(void __iomem *base, unsigned int offset)
140 {
141 	return readw(base + offset);
142 }
143 
144 static inline void ehrpwm_write(void __iomem *base, unsigned int offset,
145 				u16 value)
146 {
147 	writew(value, base + offset);
148 }
149 
150 static void ehrpwm_modify(void __iomem *base, unsigned int offset, u16 mask,
151 			  u16 value)
152 {
153 	unsigned short val;
154 
155 	val = readw(base + offset);
156 	val &= ~mask;
157 	val |= value & mask;
158 	writew(val, base + offset);
159 }
160 
161 /**
162  * set_prescale_div -	Set up the prescaler divider function
163  * @rqst_prescaler:	prescaler value min
164  * @prescale_div:	prescaler value set
165  * @tb_clk_div:		Time Base Control prescaler bits
166  */
167 static int set_prescale_div(unsigned long rqst_prescaler, u16 *prescale_div,
168 			    u16 *tb_clk_div)
169 {
170 	unsigned int clkdiv, hspclkdiv;
171 
172 	for (clkdiv = 0; clkdiv <= CLKDIV_MAX; clkdiv++) {
173 		for (hspclkdiv = 0; hspclkdiv <= HSPCLKDIV_MAX; hspclkdiv++) {
174 			/*
175 			 * calculations for prescaler value :
176 			 * prescale_div = HSPCLKDIVIDER * CLKDIVIDER.
177 			 * HSPCLKDIVIDER =  2 ** hspclkdiv
178 			 * CLKDIVIDER = (1),		if clkdiv == 0 *OR*
179 			 *		(2 * clkdiv),	if clkdiv != 0
180 			 *
181 			 * Configure prescale_div value such that period
182 			 * register value is less than 65535.
183 			 */
184 
185 			*prescale_div = (1 << clkdiv) *
186 					(hspclkdiv ? (hspclkdiv * 2) : 1);
187 			if (*prescale_div > rqst_prescaler) {
188 				*tb_clk_div = (clkdiv << TBCTL_CLKDIV_SHIFT) |
189 					(hspclkdiv << TBCTL_HSPCLKDIV_SHIFT);
190 				return 0;
191 			}
192 		}
193 	}
194 
195 	return 1;
196 }
197 
198 static void configure_polarity(struct ehrpwm_pwm_chip *pc, int chan)
199 {
200 	u16 aqctl_val, aqctl_mask;
201 	unsigned int aqctl_reg;
202 
203 	/*
204 	 * Configure PWM output to HIGH/LOW level on counter
205 	 * reaches compare register value and LOW/HIGH level
206 	 * on counter value reaches period register value and
207 	 * zero value on counter
208 	 */
209 	if (chan == 1) {
210 		aqctl_reg = AQCTLB;
211 		aqctl_mask = AQCTL_CBU_MASK;
212 
213 		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
214 			aqctl_val = AQCTL_CHANB_POLINVERSED;
215 		else
216 			aqctl_val = AQCTL_CHANB_POLNORMAL;
217 	} else {
218 		aqctl_reg = AQCTLA;
219 		aqctl_mask = AQCTL_CAU_MASK;
220 
221 		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
222 			aqctl_val = AQCTL_CHANA_POLINVERSED;
223 		else
224 			aqctl_val = AQCTL_CHANA_POLNORMAL;
225 	}
226 
227 	aqctl_mask |= AQCTL_PRD_MASK | AQCTL_ZRO_MASK;
228 	ehrpwm_modify(pc->mmio_base, aqctl_reg, aqctl_mask, aqctl_val);
229 }
230 
231 /*
232  * period_ns = 10^9 * (ps_divval * period_cycles) / PWM_CLK_RATE
233  * duty_ns   = 10^9 * (ps_divval * duty_cycles) / PWM_CLK_RATE
234  */
235 static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
236 			     int duty_ns, int period_ns)
237 {
238 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
239 	u32 period_cycles, duty_cycles;
240 	u16 ps_divval, tb_divval;
241 	unsigned int i, cmp_reg;
242 	unsigned long long c;
243 
244 	if (period_ns > NSEC_PER_SEC)
245 		return -ERANGE;
246 
247 	c = pc->clk_rate;
248 	c = c * period_ns;
249 	do_div(c, NSEC_PER_SEC);
250 	period_cycles = (unsigned long)c;
251 
252 	if (period_cycles < 1) {
253 		period_cycles = 1;
254 		duty_cycles = 1;
255 	} else {
256 		c = pc->clk_rate;
257 		c = c * duty_ns;
258 		do_div(c, NSEC_PER_SEC);
259 		duty_cycles = (unsigned long)c;
260 	}
261 
262 	/*
263 	 * Period values should be same for multiple PWM channels as IP uses
264 	 * same period register for multiple channels.
265 	 */
266 	for (i = 0; i < NUM_PWM_CHANNEL; i++) {
267 		if (pc->period_cycles[i] &&
268 				(pc->period_cycles[i] != period_cycles)) {
269 			/*
270 			 * Allow channel to reconfigure period if no other
271 			 * channels being configured.
272 			 */
273 			if (i == pwm->hwpwm)
274 				continue;
275 
276 			dev_err(chip->dev,
277 				"period value conflicts with channel %u\n",
278 				i);
279 			return -EINVAL;
280 		}
281 	}
282 
283 	pc->period_cycles[pwm->hwpwm] = period_cycles;
284 
285 	/* Configure clock prescaler to support Low frequency PWM wave */
286 	if (set_prescale_div(period_cycles/PERIOD_MAX, &ps_divval,
287 			     &tb_divval)) {
288 		dev_err(chip->dev, "Unsupported values\n");
289 		return -EINVAL;
290 	}
291 
292 	pm_runtime_get_sync(chip->dev);
293 
294 	/* Update clock prescaler values */
295 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CLKDIV_MASK, tb_divval);
296 
297 	/* Update period & duty cycle with presacler division */
298 	period_cycles = period_cycles / ps_divval;
299 	duty_cycles = duty_cycles / ps_divval;
300 
301 	/* Configure shadow loading on Period register */
302 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_PRDLD_MASK, TBCTL_PRDLD_SHDW);
303 
304 	ehrpwm_write(pc->mmio_base, TBPRD, period_cycles);
305 
306 	/* Configure ehrpwm counter for up-count mode */
307 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CTRMODE_MASK,
308 		      TBCTL_CTRMODE_UP);
309 
310 	if (pwm->hwpwm == 1)
311 		/* Channel 1 configured with compare B register */
312 		cmp_reg = CMPB;
313 	else
314 		/* Channel 0 configured with compare A register */
315 		cmp_reg = CMPA;
316 
317 	ehrpwm_write(pc->mmio_base, cmp_reg, duty_cycles);
318 
319 	pm_runtime_put_sync(chip->dev);
320 
321 	return 0;
322 }
323 
324 static int ehrpwm_pwm_set_polarity(struct pwm_chip *chip,
325 				   struct pwm_device *pwm,
326 				   enum pwm_polarity polarity)
327 {
328 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
329 
330 	/* Configuration of polarity in hardware delayed, do at enable */
331 	pc->polarity[pwm->hwpwm] = polarity;
332 
333 	return 0;
334 }
335 
336 static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
337 {
338 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
339 	u16 aqcsfrc_val, aqcsfrc_mask;
340 	int ret;
341 
342 	/* Leave clock enabled on enabling PWM */
343 	pm_runtime_get_sync(chip->dev);
344 
345 	/* Disabling Action Qualifier on PWM output */
346 	if (pwm->hwpwm) {
347 		aqcsfrc_val = AQCSFRC_CSFB_FRCDIS;
348 		aqcsfrc_mask = AQCSFRC_CSFB_MASK;
349 	} else {
350 		aqcsfrc_val = AQCSFRC_CSFA_FRCDIS;
351 		aqcsfrc_mask = AQCSFRC_CSFA_MASK;
352 	}
353 
354 	/* Changes to shadow mode */
355 	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
356 		      AQSFRC_RLDCSF_ZRO);
357 
358 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
359 
360 	/* Channels polarity can be configured from action qualifier module */
361 	configure_polarity(pc, pwm->hwpwm);
362 
363 	/* Enable TBCLK before enabling PWM device */
364 	ret = clk_enable(pc->tbclk);
365 	if (ret) {
366 		dev_err(chip->dev, "Failed to enable TBCLK for %s: %d\n",
367 			dev_name(pc->chip.dev), ret);
368 		return ret;
369 	}
370 
371 	/* Enable time counter for free_run */
372 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_FREE_RUN);
373 
374 	return 0;
375 }
376 
377 static void ehrpwm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
378 {
379 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
380 	u16 aqcsfrc_val, aqcsfrc_mask;
381 
382 	/* Action Qualifier puts PWM output low forcefully */
383 	if (pwm->hwpwm) {
384 		aqcsfrc_val = AQCSFRC_CSFB_FRCLOW;
385 		aqcsfrc_mask = AQCSFRC_CSFB_MASK;
386 	} else {
387 		aqcsfrc_val = AQCSFRC_CSFA_FRCLOW;
388 		aqcsfrc_mask = AQCSFRC_CSFA_MASK;
389 	}
390 
391 	/*
392 	 * Changes to immediate action on Action Qualifier. This puts
393 	 * Action Qualifier control on PWM output from next TBCLK
394 	 */
395 	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
396 		      AQSFRC_RLDCSF_IMDT);
397 
398 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
399 
400 	/* Disabling TBCLK on PWM disable */
401 	clk_disable(pc->tbclk);
402 
403 	/* Stop Time base counter */
404 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_STOP_NEXT);
405 
406 	/* Disable clock on PWM disable */
407 	pm_runtime_put_sync(chip->dev);
408 }
409 
410 static void ehrpwm_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
411 {
412 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
413 
414 	if (pwm_is_enabled(pwm)) {
415 		dev_warn(chip->dev, "Removing PWM device without disabling\n");
416 		pm_runtime_put_sync(chip->dev);
417 	}
418 
419 	/* set period value to zero on free */
420 	pc->period_cycles[pwm->hwpwm] = 0;
421 }
422 
423 static const struct pwm_ops ehrpwm_pwm_ops = {
424 	.free = ehrpwm_pwm_free,
425 	.config = ehrpwm_pwm_config,
426 	.set_polarity = ehrpwm_pwm_set_polarity,
427 	.enable = ehrpwm_pwm_enable,
428 	.disable = ehrpwm_pwm_disable,
429 	.owner = THIS_MODULE,
430 };
431 
432 static const struct of_device_id ehrpwm_of_match[] = {
433 	{ .compatible = "ti,am3352-ehrpwm" },
434 	{ .compatible = "ti,am33xx-ehrpwm" },
435 	{},
436 };
437 MODULE_DEVICE_TABLE(of, ehrpwm_of_match);
438 
439 static int ehrpwm_pwm_probe(struct platform_device *pdev)
440 {
441 	struct device_node *np = pdev->dev.of_node;
442 	struct ehrpwm_pwm_chip *pc;
443 	struct resource *r;
444 	struct clk *clk;
445 	int ret;
446 
447 	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
448 	if (!pc)
449 		return -ENOMEM;
450 
451 	clk = devm_clk_get(&pdev->dev, "fck");
452 	if (IS_ERR(clk)) {
453 		if (of_device_is_compatible(np, "ti,am33xx-ecap")) {
454 			dev_warn(&pdev->dev, "Binding is obsolete.\n");
455 			clk = devm_clk_get(pdev->dev.parent, "fck");
456 		}
457 	}
458 
459 	if (IS_ERR(clk)) {
460 		dev_err(&pdev->dev, "failed to get clock\n");
461 		return PTR_ERR(clk);
462 	}
463 
464 	pc->clk_rate = clk_get_rate(clk);
465 	if (!pc->clk_rate) {
466 		dev_err(&pdev->dev, "failed to get clock rate\n");
467 		return -EINVAL;
468 	}
469 
470 	pc->chip.dev = &pdev->dev;
471 	pc->chip.ops = &ehrpwm_pwm_ops;
472 	pc->chip.of_xlate = of_pwm_xlate_with_flags;
473 	pc->chip.of_pwm_n_cells = 3;
474 	pc->chip.base = -1;
475 	pc->chip.npwm = NUM_PWM_CHANNEL;
476 
477 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
478 	pc->mmio_base = devm_ioremap_resource(&pdev->dev, r);
479 	if (IS_ERR(pc->mmio_base))
480 		return PTR_ERR(pc->mmio_base);
481 
482 	/* Acquire tbclk for Time Base EHRPWM submodule */
483 	pc->tbclk = devm_clk_get(&pdev->dev, "tbclk");
484 	if (IS_ERR(pc->tbclk)) {
485 		dev_err(&pdev->dev, "Failed to get tbclk\n");
486 		return PTR_ERR(pc->tbclk);
487 	}
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(&pc->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, pc);
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 int ehrpwm_pwm_remove(struct platform_device *pdev)
513 {
514 	struct ehrpwm_pwm_chip *pc = platform_get_drvdata(pdev);
515 
516 	clk_unprepare(pc->tbclk);
517 
518 	pm_runtime_disable(&pdev->dev);
519 
520 	return pwmchip_remove(&pc->chip);
521 }
522 
523 #ifdef CONFIG_PM_SLEEP
524 static void ehrpwm_pwm_save_context(struct ehrpwm_pwm_chip *pc)
525 {
526 	pm_runtime_get_sync(pc->chip.dev);
527 
528 	pc->ctx.tbctl = ehrpwm_read(pc->mmio_base, TBCTL);
529 	pc->ctx.tbprd = ehrpwm_read(pc->mmio_base, TBPRD);
530 	pc->ctx.cmpa = ehrpwm_read(pc->mmio_base, CMPA);
531 	pc->ctx.cmpb = ehrpwm_read(pc->mmio_base, CMPB);
532 	pc->ctx.aqctla = ehrpwm_read(pc->mmio_base, AQCTLA);
533 	pc->ctx.aqctlb = ehrpwm_read(pc->mmio_base, AQCTLB);
534 	pc->ctx.aqsfrc = ehrpwm_read(pc->mmio_base, AQSFRC);
535 	pc->ctx.aqcsfrc = ehrpwm_read(pc->mmio_base, AQCSFRC);
536 
537 	pm_runtime_put_sync(pc->chip.dev);
538 }
539 
540 static void ehrpwm_pwm_restore_context(struct ehrpwm_pwm_chip *pc)
541 {
542 	ehrpwm_write(pc->mmio_base, TBPRD, pc->ctx.tbprd);
543 	ehrpwm_write(pc->mmio_base, CMPA, pc->ctx.cmpa);
544 	ehrpwm_write(pc->mmio_base, CMPB, pc->ctx.cmpb);
545 	ehrpwm_write(pc->mmio_base, AQCTLA, pc->ctx.aqctla);
546 	ehrpwm_write(pc->mmio_base, AQCTLB, pc->ctx.aqctlb);
547 	ehrpwm_write(pc->mmio_base, AQSFRC, pc->ctx.aqsfrc);
548 	ehrpwm_write(pc->mmio_base, AQCSFRC, pc->ctx.aqcsfrc);
549 	ehrpwm_write(pc->mmio_base, TBCTL, pc->ctx.tbctl);
550 }
551 
552 static int ehrpwm_pwm_suspend(struct device *dev)
553 {
554 	struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
555 	unsigned int i;
556 
557 	ehrpwm_pwm_save_context(pc);
558 
559 	for (i = 0; i < pc->chip.npwm; i++) {
560 		struct pwm_device *pwm = &pc->chip.pwms[i];
561 
562 		if (!pwm_is_enabled(pwm))
563 			continue;
564 
565 		/* Disable explicitly if PWM is running */
566 		pm_runtime_put_sync(dev);
567 	}
568 
569 	return 0;
570 }
571 
572 static int ehrpwm_pwm_resume(struct device *dev)
573 {
574 	struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
575 	unsigned int i;
576 
577 	for (i = 0; i < pc->chip.npwm; i++) {
578 		struct pwm_device *pwm = &pc->chip.pwms[i];
579 
580 		if (!pwm_is_enabled(pwm))
581 			continue;
582 
583 		/* Enable explicitly if PWM was running */
584 		pm_runtime_get_sync(dev);
585 	}
586 
587 	ehrpwm_pwm_restore_context(pc);
588 
589 	return 0;
590 }
591 #endif
592 
593 static SIMPLE_DEV_PM_OPS(ehrpwm_pwm_pm_ops, ehrpwm_pwm_suspend,
594 			 ehrpwm_pwm_resume);
595 
596 static struct platform_driver ehrpwm_pwm_driver = {
597 	.driver = {
598 		.name = "ehrpwm",
599 		.of_match_table = ehrpwm_of_match,
600 		.pm = &ehrpwm_pwm_pm_ops,
601 	},
602 	.probe = ehrpwm_pwm_probe,
603 	.remove = ehrpwm_pwm_remove,
604 };
605 module_platform_driver(ehrpwm_pwm_driver);
606 
607 MODULE_DESCRIPTION("EHRPWM PWM driver");
608 MODULE_AUTHOR("Texas Instruments");
609 MODULE_LICENSE("GPL");
610