xref: /openbmc/linux/drivers/pwm/pwm-tiehrpwm.c (revision 9cfc5c90)
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 #include "pwm-tipwmss.h"
31 
32 /* EHRPWM registers and bits definitions */
33 
34 /* Time base module registers */
35 #define TBCTL			0x00
36 #define TBPRD			0x0A
37 
38 #define TBCTL_RUN_MASK		(BIT(15) | BIT(14))
39 #define TBCTL_STOP_NEXT		0
40 #define TBCTL_STOP_ON_CYCLE	BIT(14)
41 #define TBCTL_FREE_RUN		(BIT(15) | BIT(14))
42 #define TBCTL_PRDLD_MASK	BIT(3)
43 #define TBCTL_PRDLD_SHDW	0
44 #define TBCTL_PRDLD_IMDT	BIT(3)
45 #define TBCTL_CLKDIV_MASK	(BIT(12) | BIT(11) | BIT(10) | BIT(9) | \
46 				BIT(8) | BIT(7))
47 #define TBCTL_CTRMODE_MASK	(BIT(1) | BIT(0))
48 #define TBCTL_CTRMODE_UP	0
49 #define TBCTL_CTRMODE_DOWN	BIT(0)
50 #define TBCTL_CTRMODE_UPDOWN	BIT(1)
51 #define TBCTL_CTRMODE_FREEZE	(BIT(1) | BIT(0))
52 
53 #define TBCTL_HSPCLKDIV_SHIFT	7
54 #define TBCTL_CLKDIV_SHIFT	10
55 
56 #define CLKDIV_MAX		7
57 #define HSPCLKDIV_MAX		7
58 #define PERIOD_MAX		0xFFFF
59 
60 /* compare module registers */
61 #define CMPA			0x12
62 #define CMPB			0x14
63 
64 /* Action qualifier module registers */
65 #define AQCTLA			0x16
66 #define AQCTLB			0x18
67 #define AQSFRC			0x1A
68 #define AQCSFRC			0x1C
69 
70 #define AQCTL_CBU_MASK		(BIT(9) | BIT(8))
71 #define AQCTL_CBU_FRCLOW	BIT(8)
72 #define AQCTL_CBU_FRCHIGH	BIT(9)
73 #define AQCTL_CBU_FRCTOGGLE	(BIT(9) | BIT(8))
74 #define AQCTL_CAU_MASK		(BIT(5) | BIT(4))
75 #define AQCTL_CAU_FRCLOW	BIT(4)
76 #define AQCTL_CAU_FRCHIGH	BIT(5)
77 #define AQCTL_CAU_FRCTOGGLE	(BIT(5) | BIT(4))
78 #define AQCTL_PRD_MASK		(BIT(3) | BIT(2))
79 #define AQCTL_PRD_FRCLOW	BIT(2)
80 #define AQCTL_PRD_FRCHIGH	BIT(3)
81 #define AQCTL_PRD_FRCTOGGLE	(BIT(3) | BIT(2))
82 #define AQCTL_ZRO_MASK		(BIT(1) | BIT(0))
83 #define AQCTL_ZRO_FRCLOW	BIT(0)
84 #define AQCTL_ZRO_FRCHIGH	BIT(1)
85 #define AQCTL_ZRO_FRCTOGGLE	(BIT(1) | BIT(0))
86 
87 #define AQCTL_CHANA_POLNORMAL	(AQCTL_CAU_FRCLOW | AQCTL_PRD_FRCHIGH | \
88 				AQCTL_ZRO_FRCHIGH)
89 #define AQCTL_CHANA_POLINVERSED	(AQCTL_CAU_FRCHIGH | AQCTL_PRD_FRCLOW | \
90 				AQCTL_ZRO_FRCLOW)
91 #define AQCTL_CHANB_POLNORMAL	(AQCTL_CBU_FRCLOW | AQCTL_PRD_FRCHIGH | \
92 				AQCTL_ZRO_FRCHIGH)
93 #define AQCTL_CHANB_POLINVERSED	(AQCTL_CBU_FRCHIGH | AQCTL_PRD_FRCLOW | \
94 				AQCTL_ZRO_FRCLOW)
95 
96 #define AQSFRC_RLDCSF_MASK	(BIT(7) | BIT(6))
97 #define AQSFRC_RLDCSF_ZRO	0
98 #define AQSFRC_RLDCSF_PRD	BIT(6)
99 #define AQSFRC_RLDCSF_ZROPRD	BIT(7)
100 #define AQSFRC_RLDCSF_IMDT	(BIT(7) | BIT(6))
101 
102 #define AQCSFRC_CSFB_MASK	(BIT(3) | BIT(2))
103 #define AQCSFRC_CSFB_FRCDIS	0
104 #define AQCSFRC_CSFB_FRCLOW	BIT(2)
105 #define AQCSFRC_CSFB_FRCHIGH	BIT(3)
106 #define AQCSFRC_CSFB_DISSWFRC	(BIT(3) | BIT(2))
107 #define AQCSFRC_CSFA_MASK	(BIT(1) | BIT(0))
108 #define AQCSFRC_CSFA_FRCDIS	0
109 #define AQCSFRC_CSFA_FRCLOW	BIT(0)
110 #define AQCSFRC_CSFA_FRCHIGH	BIT(1)
111 #define AQCSFRC_CSFA_DISSWFRC	(BIT(1) | BIT(0))
112 
113 #define NUM_PWM_CHANNEL		2	/* EHRPWM channels */
114 
115 struct ehrpwm_context {
116 	u16 tbctl;
117 	u16 tbprd;
118 	u16 cmpa;
119 	u16 cmpb;
120 	u16 aqctla;
121 	u16 aqctlb;
122 	u16 aqsfrc;
123 	u16 aqcsfrc;
124 };
125 
126 struct ehrpwm_pwm_chip {
127 	struct pwm_chip	chip;
128 	unsigned int	clk_rate;
129 	void __iomem	*mmio_base;
130 	unsigned long period_cycles[NUM_PWM_CHANNEL];
131 	enum pwm_polarity polarity[NUM_PWM_CHANNEL];
132 	struct	clk	*tbclk;
133 	struct ehrpwm_context ctx;
134 };
135 
136 static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
137 {
138 	return container_of(chip, struct ehrpwm_pwm_chip, chip);
139 }
140 
141 static inline u16 ehrpwm_read(void __iomem *base, int offset)
142 {
143 	return readw(base + offset);
144 }
145 
146 static inline void ehrpwm_write(void __iomem *base, int offset, unsigned int val)
147 {
148 	writew(val & 0xFFFF, base + offset);
149 }
150 
151 static void ehrpwm_modify(void __iomem *base, int offset,
152 		unsigned short mask, unsigned short val)
153 {
154 	unsigned short regval;
155 
156 	regval = readw(base + offset);
157 	regval &= ~mask;
158 	regval |= val & mask;
159 	writew(regval, base + offset);
160 }
161 
162 /**
163  * set_prescale_div -	Set up the prescaler divider function
164  * @rqst_prescaler:	prescaler value min
165  * @prescale_div:	prescaler value set
166  * @tb_clk_div:		Time Base Control prescaler bits
167  */
168 static int set_prescale_div(unsigned long rqst_prescaler,
169 		unsigned short *prescale_div, unsigned short *tb_clk_div)
170 {
171 	unsigned int clkdiv, hspclkdiv;
172 
173 	for (clkdiv = 0; clkdiv <= CLKDIV_MAX; clkdiv++) {
174 		for (hspclkdiv = 0; hspclkdiv <= HSPCLKDIV_MAX; hspclkdiv++) {
175 
176 			/*
177 			 * calculations for prescaler value :
178 			 * prescale_div = HSPCLKDIVIDER * CLKDIVIDER.
179 			 * HSPCLKDIVIDER =  2 ** hspclkdiv
180 			 * CLKDIVIDER = (1),		if clkdiv == 0 *OR*
181 			 *		(2 * clkdiv),	if clkdiv != 0
182 			 *
183 			 * Configure prescale_div value such that period
184 			 * register value is less than 65535.
185 			 */
186 
187 			*prescale_div = (1 << clkdiv) *
188 					(hspclkdiv ? (hspclkdiv * 2) : 1);
189 			if (*prescale_div > rqst_prescaler) {
190 				*tb_clk_div = (clkdiv << TBCTL_CLKDIV_SHIFT) |
191 					(hspclkdiv << TBCTL_HSPCLKDIV_SHIFT);
192 				return 0;
193 			}
194 		}
195 	}
196 	return 1;
197 }
198 
199 static void configure_polarity(struct ehrpwm_pwm_chip *pc, int chan)
200 {
201 	int aqctl_reg;
202 	unsigned short aqctl_val, aqctl_mask;
203 
204 	/*
205 	 * Configure PWM output to HIGH/LOW level on counter
206 	 * reaches compare register value and LOW/HIGH level
207 	 * on counter value reaches period register value and
208 	 * zero value on counter
209 	 */
210 	if (chan == 1) {
211 		aqctl_reg = AQCTLB;
212 		aqctl_mask = AQCTL_CBU_MASK;
213 
214 		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
215 			aqctl_val = AQCTL_CHANB_POLINVERSED;
216 		else
217 			aqctl_val = AQCTL_CHANB_POLNORMAL;
218 	} else {
219 		aqctl_reg = AQCTLA;
220 		aqctl_mask = AQCTL_CAU_MASK;
221 
222 		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
223 			aqctl_val = AQCTL_CHANA_POLINVERSED;
224 		else
225 			aqctl_val = AQCTL_CHANA_POLNORMAL;
226 	}
227 
228 	aqctl_mask |= AQCTL_PRD_MASK | AQCTL_ZRO_MASK;
229 	ehrpwm_modify(pc->mmio_base, aqctl_reg, aqctl_mask, aqctl_val);
230 }
231 
232 /*
233  * period_ns = 10^9 * (ps_divval * period_cycles) / PWM_CLK_RATE
234  * duty_ns   = 10^9 * (ps_divval * duty_cycles) / PWM_CLK_RATE
235  */
236 static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
237 		int duty_ns, int period_ns)
238 {
239 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
240 	unsigned long long c;
241 	unsigned long period_cycles, duty_cycles;
242 	unsigned short ps_divval, tb_divval;
243 	int i, cmp_reg;
244 
245 	if (period_ns > NSEC_PER_SEC)
246 		return -ERANGE;
247 
248 	c = pc->clk_rate;
249 	c = c * period_ns;
250 	do_div(c, NSEC_PER_SEC);
251 	period_cycles = (unsigned long)c;
252 
253 	if (period_cycles < 1) {
254 		period_cycles = 1;
255 		duty_cycles = 1;
256 	} else {
257 		c = pc->clk_rate;
258 		c = c * duty_ns;
259 		do_div(c, NSEC_PER_SEC);
260 		duty_cycles = (unsigned long)c;
261 	}
262 
263 	/*
264 	 * Period values should be same for multiple PWM channels as IP uses
265 	 * same period register for multiple channels.
266 	 */
267 	for (i = 0; i < NUM_PWM_CHANNEL; i++) {
268 		if (pc->period_cycles[i] &&
269 				(pc->period_cycles[i] != period_cycles)) {
270 			/*
271 			 * Allow channel to reconfigure period if no other
272 			 * channels being configured.
273 			 */
274 			if (i == pwm->hwpwm)
275 				continue;
276 
277 			dev_err(chip->dev, "Period value conflicts with channel %d\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 	return 0;
321 }
322 
323 static int ehrpwm_pwm_set_polarity(struct pwm_chip *chip,
324 		struct pwm_device *pwm,	enum pwm_polarity polarity)
325 {
326 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
327 
328 	/* Configuration of polarity in hardware delayed, do at enable */
329 	pc->polarity[pwm->hwpwm] = polarity;
330 	return 0;
331 }
332 
333 static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
334 {
335 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
336 	unsigned short aqcsfrc_val, aqcsfrc_mask;
337 	int ret;
338 
339 	/* Leave clock enabled on enabling PWM */
340 	pm_runtime_get_sync(chip->dev);
341 
342 	/* Disabling Action Qualifier on PWM output */
343 	if (pwm->hwpwm) {
344 		aqcsfrc_val = AQCSFRC_CSFB_FRCDIS;
345 		aqcsfrc_mask = AQCSFRC_CSFB_MASK;
346 	} else {
347 		aqcsfrc_val = AQCSFRC_CSFA_FRCDIS;
348 		aqcsfrc_mask = AQCSFRC_CSFA_MASK;
349 	}
350 
351 	/* Changes to shadow mode */
352 	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
353 			AQSFRC_RLDCSF_ZRO);
354 
355 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
356 
357 	/* Channels polarity can be configured from action qualifier module */
358 	configure_polarity(pc, pwm->hwpwm);
359 
360 	/* Enable TBCLK before enabling PWM device */
361 	ret = clk_enable(pc->tbclk);
362 	if (ret) {
363 		dev_err(chip->dev, "Failed to enable TBCLK for %s\n",
364 			dev_name(pc->chip.dev));
365 		return ret;
366 	}
367 
368 	/* Enable time counter for free_run */
369 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_FREE_RUN);
370 	return 0;
371 }
372 
373 static void ehrpwm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
374 {
375 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
376 	unsigned short aqcsfrc_val, aqcsfrc_mask;
377 
378 	/* Action Qualifier puts PWM output low forcefully */
379 	if (pwm->hwpwm) {
380 		aqcsfrc_val = AQCSFRC_CSFB_FRCLOW;
381 		aqcsfrc_mask = AQCSFRC_CSFB_MASK;
382 	} else {
383 		aqcsfrc_val = AQCSFRC_CSFA_FRCLOW;
384 		aqcsfrc_mask = AQCSFRC_CSFA_MASK;
385 	}
386 
387 	/*
388 	 * Changes to immediate action on Action Qualifier. This puts
389 	 * Action Qualifier control on PWM output from next TBCLK
390 	 */
391 	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
392 			AQSFRC_RLDCSF_IMDT);
393 
394 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
395 
396 	/* Disabling TBCLK on PWM disable */
397 	clk_disable(pc->tbclk);
398 
399 	/* Stop Time base counter */
400 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_STOP_NEXT);
401 
402 	/* Disable clock on PWM disable */
403 	pm_runtime_put_sync(chip->dev);
404 }
405 
406 static void ehrpwm_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
407 {
408 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
409 
410 	if (pwm_is_enabled(pwm)) {
411 		dev_warn(chip->dev, "Removing PWM device without disabling\n");
412 		pm_runtime_put_sync(chip->dev);
413 	}
414 
415 	/* set period value to zero on free */
416 	pc->period_cycles[pwm->hwpwm] = 0;
417 }
418 
419 static const struct pwm_ops ehrpwm_pwm_ops = {
420 	.free		= ehrpwm_pwm_free,
421 	.config		= ehrpwm_pwm_config,
422 	.set_polarity	= ehrpwm_pwm_set_polarity,
423 	.enable		= ehrpwm_pwm_enable,
424 	.disable	= ehrpwm_pwm_disable,
425 	.owner		= THIS_MODULE,
426 };
427 
428 static const struct of_device_id ehrpwm_of_match[] = {
429 	{ .compatible	= "ti,am33xx-ehrpwm" },
430 	{},
431 };
432 MODULE_DEVICE_TABLE(of, ehrpwm_of_match);
433 
434 static int ehrpwm_pwm_probe(struct platform_device *pdev)
435 {
436 	int ret;
437 	struct resource *r;
438 	struct clk *clk;
439 	struct ehrpwm_pwm_chip *pc;
440 	u16 status;
441 
442 	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
443 	if (!pc)
444 		return -ENOMEM;
445 
446 	clk = devm_clk_get(&pdev->dev, "fck");
447 	if (IS_ERR(clk)) {
448 		dev_err(&pdev->dev, "failed to get clock\n");
449 		return PTR_ERR(clk);
450 	}
451 
452 	pc->clk_rate = clk_get_rate(clk);
453 	if (!pc->clk_rate) {
454 		dev_err(&pdev->dev, "failed to get clock rate\n");
455 		return -EINVAL;
456 	}
457 
458 	pc->chip.dev = &pdev->dev;
459 	pc->chip.ops = &ehrpwm_pwm_ops;
460 	pc->chip.of_xlate = of_pwm_xlate_with_flags;
461 	pc->chip.of_pwm_n_cells = 3;
462 	pc->chip.base = -1;
463 	pc->chip.npwm = NUM_PWM_CHANNEL;
464 
465 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
466 	pc->mmio_base = devm_ioremap_resource(&pdev->dev, r);
467 	if (IS_ERR(pc->mmio_base))
468 		return PTR_ERR(pc->mmio_base);
469 
470 	/* Acquire tbclk for Time Base EHRPWM submodule */
471 	pc->tbclk = devm_clk_get(&pdev->dev, "tbclk");
472 	if (IS_ERR(pc->tbclk)) {
473 		dev_err(&pdev->dev, "Failed to get tbclk\n");
474 		return PTR_ERR(pc->tbclk);
475 	}
476 
477 	ret = clk_prepare(pc->tbclk);
478 	if (ret < 0) {
479 		dev_err(&pdev->dev, "clk_prepare() failed: %d\n", ret);
480 		return ret;
481 	}
482 
483 	ret = pwmchip_add(&pc->chip);
484 	if (ret < 0) {
485 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
486 		return ret;
487 	}
488 
489 	pm_runtime_enable(&pdev->dev);
490 	pm_runtime_get_sync(&pdev->dev);
491 
492 	status = pwmss_submodule_state_change(pdev->dev.parent,
493 			PWMSS_EPWMCLK_EN);
494 	if (!(status & PWMSS_EPWMCLK_EN_ACK)) {
495 		dev_err(&pdev->dev, "PWMSS config space clock enable failed\n");
496 		ret = -EINVAL;
497 		goto pwmss_clk_failure;
498 	}
499 
500 	pm_runtime_put_sync(&pdev->dev);
501 
502 	platform_set_drvdata(pdev, pc);
503 	return 0;
504 
505 pwmss_clk_failure:
506 	pm_runtime_put_sync(&pdev->dev);
507 	pm_runtime_disable(&pdev->dev);
508 	pwmchip_remove(&pc->chip);
509 	clk_unprepare(pc->tbclk);
510 	return ret;
511 }
512 
513 static int ehrpwm_pwm_remove(struct platform_device *pdev)
514 {
515 	struct ehrpwm_pwm_chip *pc = platform_get_drvdata(pdev);
516 
517 	clk_unprepare(pc->tbclk);
518 
519 	pm_runtime_get_sync(&pdev->dev);
520 	/*
521 	 * Due to hardware misbehaviour, acknowledge of the stop_req
522 	 * is missing. Hence checking of the status bit skipped.
523 	 */
524 	pwmss_submodule_state_change(pdev->dev.parent, PWMSS_EPWMCLK_STOP_REQ);
525 	pm_runtime_put_sync(&pdev->dev);
526 
527 	pm_runtime_put_sync(&pdev->dev);
528 	pm_runtime_disable(&pdev->dev);
529 	return pwmchip_remove(&pc->chip);
530 }
531 
532 #ifdef CONFIG_PM_SLEEP
533 static void ehrpwm_pwm_save_context(struct ehrpwm_pwm_chip *pc)
534 {
535 	pm_runtime_get_sync(pc->chip.dev);
536 	pc->ctx.tbctl = ehrpwm_read(pc->mmio_base, TBCTL);
537 	pc->ctx.tbprd = ehrpwm_read(pc->mmio_base, TBPRD);
538 	pc->ctx.cmpa = ehrpwm_read(pc->mmio_base, CMPA);
539 	pc->ctx.cmpb = ehrpwm_read(pc->mmio_base, CMPB);
540 	pc->ctx.aqctla = ehrpwm_read(pc->mmio_base, AQCTLA);
541 	pc->ctx.aqctlb = ehrpwm_read(pc->mmio_base, AQCTLB);
542 	pc->ctx.aqsfrc = ehrpwm_read(pc->mmio_base, AQSFRC);
543 	pc->ctx.aqcsfrc = ehrpwm_read(pc->mmio_base, AQCSFRC);
544 	pm_runtime_put_sync(pc->chip.dev);
545 }
546 
547 static void ehrpwm_pwm_restore_context(struct ehrpwm_pwm_chip *pc)
548 {
549 	ehrpwm_write(pc->mmio_base, TBPRD, pc->ctx.tbprd);
550 	ehrpwm_write(pc->mmio_base, CMPA, pc->ctx.cmpa);
551 	ehrpwm_write(pc->mmio_base, CMPB, pc->ctx.cmpb);
552 	ehrpwm_write(pc->mmio_base, AQCTLA, pc->ctx.aqctla);
553 	ehrpwm_write(pc->mmio_base, AQCTLB, pc->ctx.aqctlb);
554 	ehrpwm_write(pc->mmio_base, AQSFRC, pc->ctx.aqsfrc);
555 	ehrpwm_write(pc->mmio_base, AQCSFRC, pc->ctx.aqcsfrc);
556 	ehrpwm_write(pc->mmio_base, TBCTL, pc->ctx.tbctl);
557 }
558 
559 static int ehrpwm_pwm_suspend(struct device *dev)
560 {
561 	struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
562 	int i;
563 
564 	ehrpwm_pwm_save_context(pc);
565 	for (i = 0; i < pc->chip.npwm; i++) {
566 		struct pwm_device *pwm = &pc->chip.pwms[i];
567 
568 		if (!pwm_is_enabled(pwm))
569 			continue;
570 
571 		/* Disable explicitly if PWM is running */
572 		pm_runtime_put_sync(dev);
573 	}
574 	return 0;
575 }
576 
577 static int ehrpwm_pwm_resume(struct device *dev)
578 {
579 	struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
580 	int i;
581 
582 	for (i = 0; i < pc->chip.npwm; i++) {
583 		struct pwm_device *pwm = &pc->chip.pwms[i];
584 
585 		if (!pwm_is_enabled(pwm))
586 			continue;
587 
588 		/* Enable explicitly if PWM was running */
589 		pm_runtime_get_sync(dev);
590 	}
591 	ehrpwm_pwm_restore_context(pc);
592 	return 0;
593 }
594 #endif
595 
596 static 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	= &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