xref: /openbmc/linux/drivers/pwm/pwm-tiehrpwm.c (revision cdfce539)
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 #include <linux/pinctrl/consumer.h>
30 
31 #include "pwm-tipwmss.h"
32 
33 /* EHRPWM registers and bits definitions */
34 
35 /* Time base module registers */
36 #define TBCTL			0x00
37 #define TBPRD			0x0A
38 
39 #define TBCTL_RUN_MASK		(BIT(15) | BIT(14))
40 #define TBCTL_STOP_NEXT		0
41 #define TBCTL_STOP_ON_CYCLE	BIT(14)
42 #define TBCTL_FREE_RUN		(BIT(15) | BIT(14))
43 #define TBCTL_PRDLD_MASK	BIT(3)
44 #define TBCTL_PRDLD_SHDW	0
45 #define TBCTL_PRDLD_IMDT	BIT(3)
46 #define TBCTL_CLKDIV_MASK	(BIT(12) | BIT(11) | BIT(10) | BIT(9) | \
47 				BIT(8) | BIT(7))
48 #define TBCTL_CTRMODE_MASK	(BIT(1) | BIT(0))
49 #define TBCTL_CTRMODE_UP	0
50 #define TBCTL_CTRMODE_DOWN	BIT(0)
51 #define TBCTL_CTRMODE_UPDOWN	BIT(1)
52 #define TBCTL_CTRMODE_FREEZE	(BIT(1) | BIT(0))
53 
54 #define TBCTL_HSPCLKDIV_SHIFT	7
55 #define TBCTL_CLKDIV_SHIFT	10
56 
57 #define CLKDIV_MAX		7
58 #define HSPCLKDIV_MAX		7
59 #define PERIOD_MAX		0xFFFF
60 
61 /* compare module registers */
62 #define CMPA			0x12
63 #define CMPB			0x14
64 
65 /* Action qualifier module registers */
66 #define AQCTLA			0x16
67 #define AQCTLB			0x18
68 #define AQSFRC			0x1A
69 #define AQCSFRC			0x1C
70 
71 #define AQCTL_CBU_MASK		(BIT(9) | BIT(8))
72 #define AQCTL_CBU_FRCLOW	BIT(8)
73 #define AQCTL_CBU_FRCHIGH	BIT(9)
74 #define AQCTL_CBU_FRCTOGGLE	(BIT(9) | BIT(8))
75 #define AQCTL_CAU_MASK		(BIT(5) | BIT(4))
76 #define AQCTL_CAU_FRCLOW	BIT(4)
77 #define AQCTL_CAU_FRCHIGH	BIT(5)
78 #define AQCTL_CAU_FRCTOGGLE	(BIT(5) | BIT(4))
79 #define AQCTL_PRD_MASK		(BIT(3) | BIT(2))
80 #define AQCTL_PRD_FRCLOW	BIT(2)
81 #define AQCTL_PRD_FRCHIGH	BIT(3)
82 #define AQCTL_PRD_FRCTOGGLE	(BIT(3) | BIT(2))
83 #define AQCTL_ZRO_MASK		(BIT(1) | BIT(0))
84 #define AQCTL_ZRO_FRCLOW	BIT(0)
85 #define AQCTL_ZRO_FRCHIGH	BIT(1)
86 #define AQCTL_ZRO_FRCTOGGLE	(BIT(1) | BIT(0))
87 
88 #define AQCTL_CHANA_POLNORMAL	(AQCTL_CAU_FRCLOW | AQCTL_PRD_FRCHIGH | \
89 				AQCTL_ZRO_FRCHIGH)
90 #define AQCTL_CHANA_POLINVERSED	(AQCTL_CAU_FRCHIGH | AQCTL_PRD_FRCLOW | \
91 				AQCTL_ZRO_FRCLOW)
92 #define AQCTL_CHANB_POLNORMAL	(AQCTL_CBU_FRCLOW | AQCTL_PRD_FRCHIGH | \
93 				AQCTL_ZRO_FRCHIGH)
94 #define AQCTL_CHANB_POLINVERSED	(AQCTL_CBU_FRCHIGH | AQCTL_PRD_FRCLOW | \
95 				AQCTL_ZRO_FRCLOW)
96 
97 #define AQSFRC_RLDCSF_MASK	(BIT(7) | BIT(6))
98 #define AQSFRC_RLDCSF_ZRO	0
99 #define AQSFRC_RLDCSF_PRD	BIT(6)
100 #define AQSFRC_RLDCSF_ZROPRD	BIT(7)
101 #define AQSFRC_RLDCSF_IMDT	(BIT(7) | BIT(6))
102 
103 #define AQCSFRC_CSFB_MASK	(BIT(3) | BIT(2))
104 #define AQCSFRC_CSFB_FRCDIS	0
105 #define AQCSFRC_CSFB_FRCLOW	BIT(2)
106 #define AQCSFRC_CSFB_FRCHIGH	BIT(3)
107 #define AQCSFRC_CSFB_DISSWFRC	(BIT(3) | BIT(2))
108 #define AQCSFRC_CSFA_MASK	(BIT(1) | BIT(0))
109 #define AQCSFRC_CSFA_FRCDIS	0
110 #define AQCSFRC_CSFA_FRCLOW	BIT(0)
111 #define AQCSFRC_CSFA_FRCHIGH	BIT(1)
112 #define AQCSFRC_CSFA_DISSWFRC	(BIT(1) | BIT(0))
113 
114 #define NUM_PWM_CHANNEL		2	/* EHRPWM channels */
115 
116 struct ehrpwm_context {
117 	u16 tbctl;
118 	u16 tbprd;
119 	u16 cmpa;
120 	u16 cmpb;
121 	u16 aqctla;
122 	u16 aqctlb;
123 	u16 aqsfrc;
124 	u16 aqcsfrc;
125 };
126 
127 struct ehrpwm_pwm_chip {
128 	struct pwm_chip	chip;
129 	unsigned int	clk_rate;
130 	void __iomem	*mmio_base;
131 	unsigned long period_cycles[NUM_PWM_CHANNEL];
132 	enum pwm_polarity polarity[NUM_PWM_CHANNEL];
133 	struct	clk	*tbclk;
134 	struct ehrpwm_context ctx;
135 };
136 
137 static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
138 {
139 	return container_of(chip, struct ehrpwm_pwm_chip, chip);
140 }
141 
142 static u16 ehrpwm_read(void *base, int offset)
143 {
144 	return readw(base + offset);
145 }
146 
147 static void ehrpwm_write(void *base, int offset, unsigned int val)
148 {
149 	writew(val & 0xFFFF, base + offset);
150 }
151 
152 static void ehrpwm_modify(void *base, int offset,
153 		unsigned short mask, unsigned short val)
154 {
155 	unsigned short regval;
156 
157 	regval = readw(base + offset);
158 	regval &= ~mask;
159 	regval |= val & mask;
160 	writew(regval, base + offset);
161 }
162 
163 /**
164  * set_prescale_div -	Set up the prescaler divider function
165  * @rqst_prescaler:	prescaler value min
166  * @prescale_div:	prescaler value set
167  * @tb_clk_div:		Time Base Control prescaler bits
168  */
169 static int set_prescale_div(unsigned long rqst_prescaler,
170 		unsigned short *prescale_div, unsigned short *tb_clk_div)
171 {
172 	unsigned int clkdiv, hspclkdiv;
173 
174 	for (clkdiv = 0; clkdiv <= CLKDIV_MAX; clkdiv++) {
175 		for (hspclkdiv = 0; hspclkdiv <= HSPCLKDIV_MAX; hspclkdiv++) {
176 
177 			/*
178 			 * calculations for prescaler value :
179 			 * prescale_div = HSPCLKDIVIDER * CLKDIVIDER.
180 			 * HSPCLKDIVIDER =  2 ** hspclkdiv
181 			 * CLKDIVIDER = (1),		if clkdiv == 0 *OR*
182 			 *		(2 * clkdiv),	if clkdiv != 0
183 			 *
184 			 * Configure prescale_div value such that period
185 			 * register value is less than 65535.
186 			 */
187 
188 			*prescale_div = (1 << clkdiv) *
189 					(hspclkdiv ? (hspclkdiv * 2) : 1);
190 			if (*prescale_div > rqst_prescaler) {
191 				*tb_clk_div = (clkdiv << TBCTL_CLKDIV_SHIFT) |
192 					(hspclkdiv << TBCTL_HSPCLKDIV_SHIFT);
193 				return 0;
194 			}
195 		}
196 	}
197 	return 1;
198 }
199 
200 static void configure_polarity(struct ehrpwm_pwm_chip *pc, int chan)
201 {
202 	int aqctl_reg;
203 	unsigned short aqctl_val, aqctl_mask;
204 
205 	/*
206 	 * Configure PWM output to HIGH/LOW level on counter
207 	 * reaches compare register value and LOW/HIGH level
208 	 * on counter value reaches period register value and
209 	 * zero value on counter
210 	 */
211 	if (chan == 1) {
212 		aqctl_reg = AQCTLB;
213 		aqctl_mask = AQCTL_CBU_MASK;
214 
215 		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
216 			aqctl_val = AQCTL_CHANB_POLINVERSED;
217 		else
218 			aqctl_val = AQCTL_CHANB_POLNORMAL;
219 	} else {
220 		aqctl_reg = AQCTLA;
221 		aqctl_mask = AQCTL_CAU_MASK;
222 
223 		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
224 			aqctl_val = AQCTL_CHANA_POLINVERSED;
225 		else
226 			aqctl_val = AQCTL_CHANA_POLNORMAL;
227 	}
228 
229 	aqctl_mask |= AQCTL_PRD_MASK | AQCTL_ZRO_MASK;
230 	ehrpwm_modify(pc->mmio_base, aqctl_reg, aqctl_mask, aqctl_val);
231 }
232 
233 /*
234  * period_ns = 10^9 * (ps_divval * period_cycles) / PWM_CLK_RATE
235  * duty_ns   = 10^9 * (ps_divval * duty_cycles) / PWM_CLK_RATE
236  */
237 static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
238 		int duty_ns, int period_ns)
239 {
240 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
241 	unsigned long long c;
242 	unsigned long period_cycles, duty_cycles;
243 	unsigned short ps_divval, tb_divval;
244 	int i, cmp_reg;
245 
246 	if (period_ns > NSEC_PER_SEC)
247 		return -ERANGE;
248 
249 	c = pc->clk_rate;
250 	c = c * period_ns;
251 	do_div(c, NSEC_PER_SEC);
252 	period_cycles = (unsigned long)c;
253 
254 	if (period_cycles < 1) {
255 		period_cycles = 1;
256 		duty_cycles = 1;
257 	} else {
258 		c = pc->clk_rate;
259 		c = c * duty_ns;
260 		do_div(c, NSEC_PER_SEC);
261 		duty_cycles = (unsigned long)c;
262 	}
263 
264 	/*
265 	 * Period values should be same for multiple PWM channels as IP uses
266 	 * same period register for multiple channels.
267 	 */
268 	for (i = 0; i < NUM_PWM_CHANNEL; i++) {
269 		if (pc->period_cycles[i] &&
270 				(pc->period_cycles[i] != period_cycles)) {
271 			/*
272 			 * Allow channel to reconfigure period if no other
273 			 * channels being configured.
274 			 */
275 			if (i == pwm->hwpwm)
276 				continue;
277 
278 			dev_err(chip->dev, "Period value conflicts with channel %d\n",
279 					i);
280 			return -EINVAL;
281 		}
282 	}
283 
284 	pc->period_cycles[pwm->hwpwm] = period_cycles;
285 
286 	/* Configure clock prescaler to support Low frequency PWM wave */
287 	if (set_prescale_div(period_cycles/PERIOD_MAX, &ps_divval,
288 				&tb_divval)) {
289 		dev_err(chip->dev, "Unsupported values\n");
290 		return -EINVAL;
291 	}
292 
293 	pm_runtime_get_sync(chip->dev);
294 
295 	/* Update clock prescaler values */
296 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CLKDIV_MASK, tb_divval);
297 
298 	/* Update period & duty cycle with presacler division */
299 	period_cycles = period_cycles / ps_divval;
300 	duty_cycles = duty_cycles / ps_divval;
301 
302 	/* Configure shadow loading on Period register */
303 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_PRDLD_MASK, TBCTL_PRDLD_SHDW);
304 
305 	ehrpwm_write(pc->mmio_base, TBPRD, period_cycles);
306 
307 	/* Configure ehrpwm counter for up-count mode */
308 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CTRMODE_MASK,
309 			TBCTL_CTRMODE_UP);
310 
311 	if (pwm->hwpwm == 1)
312 		/* Channel 1 configured with compare B register */
313 		cmp_reg = CMPB;
314 	else
315 		/* Channel 0 configured with compare A register */
316 		cmp_reg = CMPA;
317 
318 	ehrpwm_write(pc->mmio_base, cmp_reg, duty_cycles);
319 
320 	pm_runtime_put_sync(chip->dev);
321 	return 0;
322 }
323 
324 static int ehrpwm_pwm_set_polarity(struct pwm_chip *chip,
325 		struct pwm_device *pwm,	enum pwm_polarity polarity)
326 {
327 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
328 
329 	/* Configuration of polarity in hardware delayed, do at enable */
330 	pc->polarity[pwm->hwpwm] = polarity;
331 	return 0;
332 }
333 
334 static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
335 {
336 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
337 	unsigned short aqcsfrc_val, aqcsfrc_mask;
338 	int ret;
339 
340 	/* Leave clock enabled on enabling PWM */
341 	pm_runtime_get_sync(chip->dev);
342 
343 	/* Disabling Action Qualifier on PWM output */
344 	if (pwm->hwpwm) {
345 		aqcsfrc_val = AQCSFRC_CSFB_FRCDIS;
346 		aqcsfrc_mask = AQCSFRC_CSFB_MASK;
347 	} else {
348 		aqcsfrc_val = AQCSFRC_CSFA_FRCDIS;
349 		aqcsfrc_mask = AQCSFRC_CSFA_MASK;
350 	}
351 
352 	/* Changes to shadow mode */
353 	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
354 			AQSFRC_RLDCSF_ZRO);
355 
356 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
357 
358 	/* Channels polarity can be configured from action qualifier module */
359 	configure_polarity(pc, pwm->hwpwm);
360 
361 	/* Enable TBCLK before enabling PWM device */
362 	ret = clk_prepare_enable(pc->tbclk);
363 	if (ret) {
364 		pr_err("Failed to enable TBCLK for %s\n",
365 				dev_name(pc->chip.dev));
366 		return ret;
367 	}
368 
369 	/* Enable time counter for free_run */
370 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_FREE_RUN);
371 	return 0;
372 }
373 
374 static void ehrpwm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
375 {
376 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
377 	unsigned short aqcsfrc_val, aqcsfrc_mask;
378 
379 	/* Action Qualifier puts PWM output low forcefully */
380 	if (pwm->hwpwm) {
381 		aqcsfrc_val = AQCSFRC_CSFB_FRCLOW;
382 		aqcsfrc_mask = AQCSFRC_CSFB_MASK;
383 	} else {
384 		aqcsfrc_val = AQCSFRC_CSFA_FRCLOW;
385 		aqcsfrc_mask = AQCSFRC_CSFA_MASK;
386 	}
387 
388 	/*
389 	 * Changes to immediate action on Action Qualifier. This puts
390 	 * Action Qualifier control on PWM output from next TBCLK
391 	 */
392 	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
393 			AQSFRC_RLDCSF_IMDT);
394 
395 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
396 
397 	/* Disabling TBCLK on PWM disable */
398 	clk_disable_unprepare(pc->tbclk);
399 
400 	/* Stop Time base counter */
401 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_STOP_NEXT);
402 
403 	/* Disable clock on PWM disable */
404 	pm_runtime_put_sync(chip->dev);
405 }
406 
407 static void ehrpwm_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
408 {
409 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
410 
411 	if (test_bit(PWMF_ENABLED, &pwm->flags)) {
412 		dev_warn(chip->dev, "Removing PWM device without disabling\n");
413 		pm_runtime_put_sync(chip->dev);
414 	}
415 
416 	/* set period value to zero on free */
417 	pc->period_cycles[pwm->hwpwm] = 0;
418 }
419 
420 static const struct pwm_ops ehrpwm_pwm_ops = {
421 	.free		= ehrpwm_pwm_free,
422 	.config		= ehrpwm_pwm_config,
423 	.set_polarity	= ehrpwm_pwm_set_polarity,
424 	.enable		= ehrpwm_pwm_enable,
425 	.disable	= ehrpwm_pwm_disable,
426 	.owner		= THIS_MODULE,
427 };
428 
429 static const struct of_device_id ehrpwm_of_match[] = {
430 	{ .compatible	= "ti,am33xx-ehrpwm" },
431 	{},
432 };
433 MODULE_DEVICE_TABLE(of, ehrpwm_of_match);
434 
435 static int ehrpwm_pwm_probe(struct platform_device *pdev)
436 {
437 	int ret;
438 	struct resource *r;
439 	struct clk *clk;
440 	struct ehrpwm_pwm_chip *pc;
441 	u16 status;
442 	struct pinctrl *pinctrl;
443 
444 	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
445 	if (IS_ERR(pinctrl))
446 		dev_warn(&pdev->dev, "unable to select pin group\n");
447 
448 	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
449 	if (!pc) {
450 		dev_err(&pdev->dev, "failed to allocate memory\n");
451 		return -ENOMEM;
452 	}
453 
454 	clk = devm_clk_get(&pdev->dev, "fck");
455 	if (IS_ERR(clk)) {
456 		dev_err(&pdev->dev, "failed to get clock\n");
457 		return PTR_ERR(clk);
458 	}
459 
460 	pc->clk_rate = clk_get_rate(clk);
461 	if (!pc->clk_rate) {
462 		dev_err(&pdev->dev, "failed to get clock rate\n");
463 		return -EINVAL;
464 	}
465 
466 	pc->chip.dev = &pdev->dev;
467 	pc->chip.ops = &ehrpwm_pwm_ops;
468 	pc->chip.of_xlate = of_pwm_xlate_with_flags;
469 	pc->chip.of_pwm_n_cells = 3;
470 	pc->chip.base = -1;
471 	pc->chip.npwm = NUM_PWM_CHANNEL;
472 
473 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
474 	pc->mmio_base = devm_ioremap_resource(&pdev->dev, r);
475 	if (IS_ERR(pc->mmio_base))
476 		return PTR_ERR(pc->mmio_base);
477 
478 	/* Acquire tbclk for Time Base EHRPWM submodule */
479 	pc->tbclk = devm_clk_get(&pdev->dev, "tbclk");
480 	if (IS_ERR(pc->tbclk)) {
481 		dev_err(&pdev->dev, "Failed to get tbclk\n");
482 		return PTR_ERR(pc->tbclk);
483 	}
484 
485 	ret = pwmchip_add(&pc->chip);
486 	if (ret < 0) {
487 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
488 		return ret;
489 	}
490 
491 	pm_runtime_enable(&pdev->dev);
492 	pm_runtime_get_sync(&pdev->dev);
493 
494 	status = pwmss_submodule_state_change(pdev->dev.parent,
495 			PWMSS_EPWMCLK_EN);
496 	if (!(status & PWMSS_EPWMCLK_EN_ACK)) {
497 		dev_err(&pdev->dev, "PWMSS config space clock enable failed\n");
498 		ret = -EINVAL;
499 		goto pwmss_clk_failure;
500 	}
501 
502 	pm_runtime_put_sync(&pdev->dev);
503 
504 	platform_set_drvdata(pdev, pc);
505 	return 0;
506 
507 pwmss_clk_failure:
508 	pm_runtime_put_sync(&pdev->dev);
509 	pm_runtime_disable(&pdev->dev);
510 	pwmchip_remove(&pc->chip);
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 	pm_runtime_get_sync(&pdev->dev);
519 	/*
520 	 * Due to hardware misbehaviour, acknowledge of the stop_req
521 	 * is missing. Hence checking of the status bit skipped.
522 	 */
523 	pwmss_submodule_state_change(pdev->dev.parent, PWMSS_EPWMCLK_STOP_REQ);
524 	pm_runtime_put_sync(&pdev->dev);
525 
526 	pm_runtime_put_sync(&pdev->dev);
527 	pm_runtime_disable(&pdev->dev);
528 	return pwmchip_remove(&pc->chip);
529 }
530 
531 static void ehrpwm_pwm_save_context(struct ehrpwm_pwm_chip *pc)
532 {
533 	pm_runtime_get_sync(pc->chip.dev);
534 	pc->ctx.tbctl = ehrpwm_read(pc->mmio_base, TBCTL);
535 	pc->ctx.tbprd = ehrpwm_read(pc->mmio_base, TBPRD);
536 	pc->ctx.cmpa = ehrpwm_read(pc->mmio_base, CMPA);
537 	pc->ctx.cmpb = ehrpwm_read(pc->mmio_base, CMPB);
538 	pc->ctx.aqctla = ehrpwm_read(pc->mmio_base, AQCTLA);
539 	pc->ctx.aqctlb = ehrpwm_read(pc->mmio_base, AQCTLB);
540 	pc->ctx.aqsfrc = ehrpwm_read(pc->mmio_base, AQSFRC);
541 	pc->ctx.aqcsfrc = ehrpwm_read(pc->mmio_base, AQCSFRC);
542 	pm_runtime_put_sync(pc->chip.dev);
543 }
544 
545 static void ehrpwm_pwm_restore_context(struct ehrpwm_pwm_chip *pc)
546 {
547 	ehrpwm_write(pc->mmio_base, TBPRD, pc->ctx.tbprd);
548 	ehrpwm_write(pc->mmio_base, CMPA, pc->ctx.cmpa);
549 	ehrpwm_write(pc->mmio_base, CMPB, pc->ctx.cmpb);
550 	ehrpwm_write(pc->mmio_base, AQCTLA, pc->ctx.aqctla);
551 	ehrpwm_write(pc->mmio_base, AQCTLB, pc->ctx.aqctlb);
552 	ehrpwm_write(pc->mmio_base, AQSFRC, pc->ctx.aqsfrc);
553 	ehrpwm_write(pc->mmio_base, AQCSFRC, pc->ctx.aqcsfrc);
554 	ehrpwm_write(pc->mmio_base, TBCTL, pc->ctx.tbctl);
555 }
556 
557 #ifdef CONFIG_PM_SLEEP
558 static int ehrpwm_pwm_suspend(struct device *dev)
559 {
560 	struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
561 	int i;
562 
563 	ehrpwm_pwm_save_context(pc);
564 	for (i = 0; i < pc->chip.npwm; i++) {
565 		struct pwm_device *pwm = &pc->chip.pwms[i];
566 
567 		if (!test_bit(PWMF_ENABLED, &pwm->flags))
568 			continue;
569 
570 		/* Disable explicitly if PWM is running */
571 		pm_runtime_put_sync(dev);
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 	int i;
580 
581 	for (i = 0; i < pc->chip.npwm; i++) {
582 		struct pwm_device *pwm = &pc->chip.pwms[i];
583 
584 		if (!test_bit(PWMF_ENABLED, &pwm->flags))
585 			continue;
586 
587 		/* Enable explicitly if PWM was running */
588 		pm_runtime_get_sync(dev);
589 	}
590 	ehrpwm_pwm_restore_context(pc);
591 	return 0;
592 }
593 #endif
594 
595 static SIMPLE_DEV_PM_OPS(ehrpwm_pwm_pm_ops, ehrpwm_pwm_suspend,
596 		ehrpwm_pwm_resume);
597 
598 static struct platform_driver ehrpwm_pwm_driver = {
599 	.driver = {
600 		.name	= "ehrpwm",
601 		.owner	= THIS_MODULE,
602 		.of_match_table = ehrpwm_of_match,
603 		.pm	= &ehrpwm_pwm_pm_ops,
604 	},
605 	.probe = ehrpwm_pwm_probe,
606 	.remove = ehrpwm_pwm_remove,
607 };
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