xref: /linux/drivers/pwm/pwm-pca9685.c (revision 6315d93541f8a5f77c5ef5c4f25233e66d189603)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Driver for PCA9685 16-channel 12-bit PWM LED controller
4  *
5  * Copyright (C) 2013 Steffen Trumtrar <s.trumtrar@pengutronix.de>
6  * Copyright (C) 2015 Clemens Gruber <clemens.gruber@pqgruber.com>
7  *
8  * based on the pwm-twl-led.c driver
9  */
10 
11 #include <linux/gpio/driver.h>
12 #include <linux/i2c.h>
13 #include <linux/module.h>
14 #include <linux/mutex.h>
15 #include <linux/platform_device.h>
16 #include <linux/property.h>
17 #include <linux/pwm.h>
18 #include <linux/regmap.h>
19 #include <linux/slab.h>
20 #include <linux/delay.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/bitmap.h>
23 
24 /*
25  * Because the PCA9685 has only one prescaler per chip, only the first channel
26  * that is enabled is allowed to change the prescale register.
27  * PWM channels requested afterwards must use a period that results in the same
28  * prescale setting as the one set by the first requested channel.
29  * GPIOs do not count as enabled PWMs as they are not using the prescaler.
30  */
31 
32 #define PCA9685_MODE1		0x00
33 #define PCA9685_MODE2		0x01
34 #define PCA9685_SUBADDR1	0x02
35 #define PCA9685_SUBADDR2	0x03
36 #define PCA9685_SUBADDR3	0x04
37 #define PCA9685_ALLCALLADDR	0x05
38 #define PCA9685_LEDX_ON_L	0x06
39 #define PCA9685_LEDX_ON_H	0x07
40 #define PCA9685_LEDX_OFF_L	0x08
41 #define PCA9685_LEDX_OFF_H	0x09
42 
43 #define PCA9685_ALL_LED_ON_L	0xFA
44 #define PCA9685_ALL_LED_ON_H	0xFB
45 #define PCA9685_ALL_LED_OFF_L	0xFC
46 #define PCA9685_ALL_LED_OFF_H	0xFD
47 #define PCA9685_PRESCALE	0xFE
48 
49 #define PCA9685_PRESCALE_MIN	0x03	/* => max. frequency of 1526 Hz */
50 #define PCA9685_PRESCALE_MAX	0xFF	/* => min. frequency of 24 Hz */
51 
52 #define PCA9685_COUNTER_RANGE	4096
53 #define PCA9685_OSC_CLOCK_MHZ	25	/* Internal oscillator with 25 MHz */
54 
55 #define PCA9685_NUMREGS		0xFF
56 #define PCA9685_MAXCHAN		0x10
57 
58 #define LED_FULL		BIT(4)
59 #define MODE1_ALLCALL		BIT(0)
60 #define MODE1_SUB3		BIT(1)
61 #define MODE1_SUB2		BIT(2)
62 #define MODE1_SUB1		BIT(3)
63 #define MODE1_SLEEP		BIT(4)
64 #define MODE2_INVRT		BIT(4)
65 #define MODE2_OUTDRV		BIT(2)
66 
67 #define LED_N_ON_H(N)	(PCA9685_LEDX_ON_H + (4 * (N)))
68 #define LED_N_ON_L(N)	(PCA9685_LEDX_ON_L + (4 * (N)))
69 #define LED_N_OFF_H(N)	(PCA9685_LEDX_OFF_H + (4 * (N)))
70 #define LED_N_OFF_L(N)	(PCA9685_LEDX_OFF_L + (4 * (N)))
71 
72 #define REG_ON_H(C)	((C) >= PCA9685_MAXCHAN ? PCA9685_ALL_LED_ON_H : LED_N_ON_H((C)))
73 #define REG_ON_L(C)	((C) >= PCA9685_MAXCHAN ? PCA9685_ALL_LED_ON_L : LED_N_ON_L((C)))
74 #define REG_OFF_H(C)	((C) >= PCA9685_MAXCHAN ? PCA9685_ALL_LED_OFF_H : LED_N_OFF_H((C)))
75 #define REG_OFF_L(C)	((C) >= PCA9685_MAXCHAN ? PCA9685_ALL_LED_OFF_L : LED_N_OFF_L((C)))
76 
77 struct pca9685 {
78 	struct regmap *regmap;
79 	struct mutex lock;
80 	DECLARE_BITMAP(pwms_enabled, PCA9685_MAXCHAN + 1);
81 #if IS_ENABLED(CONFIG_GPIOLIB)
82 	struct gpio_chip gpio;
83 	DECLARE_BITMAP(pwms_inuse, PCA9685_MAXCHAN + 1);
84 #endif
85 };
86 
87 static inline struct pca9685 *to_pca(struct pwm_chip *chip)
88 {
89 	return pwmchip_get_drvdata(chip);
90 }
91 
92 /* This function is supposed to be called with the lock mutex held */
93 static bool pca9685_prescaler_can_change(struct pca9685 *pca, int channel)
94 {
95 	/* No PWM enabled: Change allowed */
96 	if (bitmap_empty(pca->pwms_enabled, PCA9685_MAXCHAN + 1))
97 		return true;
98 	/* More than one PWM enabled: Change not allowed */
99 	if (bitmap_weight(pca->pwms_enabled, PCA9685_MAXCHAN + 1) > 1)
100 		return false;
101 	/*
102 	 * Only one PWM enabled: Change allowed if the PWM about to
103 	 * be changed is the one that is already enabled
104 	 */
105 	return test_bit(channel, pca->pwms_enabled);
106 }
107 
108 static int pca9685_read_reg(struct pwm_chip *chip, unsigned int reg, unsigned int *val)
109 {
110 	struct pca9685 *pca = to_pca(chip);
111 	struct device *dev = pwmchip_parent(chip);
112 	int err;
113 
114 	err = regmap_read(pca->regmap, reg, val);
115 	if (err)
116 		dev_err(dev, "regmap_read of register 0x%x failed: %pe\n", reg, ERR_PTR(err));
117 
118 	return err;
119 }
120 
121 static int pca9685_write_reg(struct pwm_chip *chip, unsigned int reg, unsigned int val)
122 {
123 	struct pca9685 *pca = to_pca(chip);
124 	struct device *dev = pwmchip_parent(chip);
125 	int err;
126 
127 	err = regmap_write(pca->regmap, reg, val);
128 	if (err)
129 		dev_err(dev, "regmap_write to register 0x%x failed: %pe\n", reg, ERR_PTR(err));
130 
131 	return err;
132 }
133 
134 /* Helper function to set the duty cycle ratio to duty/4096 (e.g. duty=2048 -> 50%) */
135 static void pca9685_pwm_set_duty(struct pwm_chip *chip, int channel, unsigned int duty)
136 {
137 	struct pwm_device *pwm = &chip->pwms[channel];
138 	unsigned int on, off;
139 
140 	if (duty == 0) {
141 		/* Set the full OFF bit, which has the highest precedence */
142 		pca9685_write_reg(chip, REG_OFF_H(channel), LED_FULL);
143 		return;
144 	} else if (duty >= PCA9685_COUNTER_RANGE) {
145 		/* Set the full ON bit and clear the full OFF bit */
146 		pca9685_write_reg(chip, REG_ON_H(channel), LED_FULL);
147 		pca9685_write_reg(chip, REG_OFF_H(channel), 0);
148 		return;
149 	}
150 
151 
152 	if (pwm->state.usage_power && channel < PCA9685_MAXCHAN) {
153 		/*
154 		 * If usage_power is set, the pca9685 driver will phase shift
155 		 * the individual channels relative to their channel number.
156 		 * This improves EMI because the enabled channels no longer
157 		 * turn on at the same time, while still maintaining the
158 		 * configured duty cycle / power output.
159 		 */
160 		on = channel * PCA9685_COUNTER_RANGE / PCA9685_MAXCHAN;
161 	} else
162 		on = 0;
163 
164 	off = (on + duty) % PCA9685_COUNTER_RANGE;
165 
166 	/* Set ON time (clears full ON bit) */
167 	pca9685_write_reg(chip, REG_ON_L(channel), on & 0xff);
168 	pca9685_write_reg(chip, REG_ON_H(channel), (on >> 8) & 0xf);
169 	/* Set OFF time (clears full OFF bit) */
170 	pca9685_write_reg(chip, REG_OFF_L(channel), off & 0xff);
171 	pca9685_write_reg(chip, REG_OFF_H(channel), (off >> 8) & 0xf);
172 }
173 
174 static unsigned int pca9685_pwm_get_duty(struct pwm_chip *chip, int channel)
175 {
176 	struct pwm_device *pwm = &chip->pwms[channel];
177 	unsigned int off = 0, on = 0, val = 0;
178 
179 	if (WARN_ON(channel >= PCA9685_MAXCHAN)) {
180 		/* HW does not support reading state of "all LEDs" channel */
181 		return 0;
182 	}
183 
184 	pca9685_read_reg(chip, LED_N_OFF_H(channel), &off);
185 	if (off & LED_FULL) {
186 		/* Full OFF bit is set */
187 		return 0;
188 	}
189 
190 	pca9685_read_reg(chip, LED_N_ON_H(channel), &on);
191 	if (on & LED_FULL) {
192 		/* Full ON bit is set */
193 		return PCA9685_COUNTER_RANGE;
194 	}
195 
196 	pca9685_read_reg(chip, LED_N_OFF_L(channel), &val);
197 	off = ((off & 0xf) << 8) | (val & 0xff);
198 	if (!pwm->state.usage_power)
199 		return off;
200 
201 	/* Read ON register to calculate duty cycle of staggered output */
202 	if (pca9685_read_reg(chip, LED_N_ON_L(channel), &val)) {
203 		/* Reset val to 0 in case reading LED_N_ON_L failed */
204 		val = 0;
205 	}
206 	on = ((on & 0xf) << 8) | (val & 0xff);
207 	return (off - on) & (PCA9685_COUNTER_RANGE - 1);
208 }
209 
210 #if IS_ENABLED(CONFIG_GPIOLIB)
211 static bool pca9685_pwm_test_and_set_inuse(struct pca9685 *pca, int pwm_idx)
212 {
213 	bool is_inuse;
214 
215 	mutex_lock(&pca->lock);
216 	if (pwm_idx >= PCA9685_MAXCHAN) {
217 		/*
218 		 * "All LEDs" channel:
219 		 * pretend already in use if any of the PWMs are requested
220 		 */
221 		if (!bitmap_empty(pca->pwms_inuse, PCA9685_MAXCHAN)) {
222 			is_inuse = true;
223 			goto out;
224 		}
225 	} else {
226 		/*
227 		 * Regular channel:
228 		 * pretend already in use if the "all LEDs" channel is requested
229 		 */
230 		if (test_bit(PCA9685_MAXCHAN, pca->pwms_inuse)) {
231 			is_inuse = true;
232 			goto out;
233 		}
234 	}
235 	is_inuse = test_and_set_bit(pwm_idx, pca->pwms_inuse);
236 out:
237 	mutex_unlock(&pca->lock);
238 	return is_inuse;
239 }
240 
241 static void pca9685_pwm_clear_inuse(struct pca9685 *pca, int pwm_idx)
242 {
243 	mutex_lock(&pca->lock);
244 	clear_bit(pwm_idx, pca->pwms_inuse);
245 	mutex_unlock(&pca->lock);
246 }
247 
248 static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset)
249 {
250 	struct pwm_chip *chip = gpiochip_get_data(gpio);
251 	struct pca9685 *pca = to_pca(chip);
252 
253 	if (pca9685_pwm_test_and_set_inuse(pca, offset))
254 		return -EBUSY;
255 	pm_runtime_get_sync(pwmchip_parent(chip));
256 	return 0;
257 }
258 
259 static int pca9685_pwm_gpio_get(struct gpio_chip *gpio, unsigned int offset)
260 {
261 	struct pwm_chip *chip = gpiochip_get_data(gpio);
262 
263 	return pca9685_pwm_get_duty(chip, offset) != 0;
264 }
265 
266 static void pca9685_pwm_gpio_set(struct gpio_chip *gpio, unsigned int offset,
267 				 int value)
268 {
269 	struct pwm_chip *chip = gpiochip_get_data(gpio);
270 
271 	pca9685_pwm_set_duty(chip, offset, value ? PCA9685_COUNTER_RANGE : 0);
272 }
273 
274 static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset)
275 {
276 	struct pwm_chip *chip = gpiochip_get_data(gpio);
277 	struct pca9685 *pca = to_pca(chip);
278 
279 	pca9685_pwm_set_duty(chip, offset, 0);
280 	pm_runtime_put(pwmchip_parent(chip));
281 	pca9685_pwm_clear_inuse(pca, offset);
282 }
283 
284 static int pca9685_pwm_gpio_get_direction(struct gpio_chip *chip,
285 					  unsigned int offset)
286 {
287 	/* Always out */
288 	return GPIO_LINE_DIRECTION_OUT;
289 }
290 
291 static int pca9685_pwm_gpio_direction_input(struct gpio_chip *gpio,
292 					    unsigned int offset)
293 {
294 	return -EINVAL;
295 }
296 
297 static int pca9685_pwm_gpio_direction_output(struct gpio_chip *gpio,
298 					     unsigned int offset, int value)
299 {
300 	pca9685_pwm_gpio_set(gpio, offset, value);
301 
302 	return 0;
303 }
304 
305 /*
306  * The PCA9685 has a bit for turning the PWM output full off or on. Some
307  * boards like Intel Galileo actually uses these as normal GPIOs so we
308  * expose a GPIO chip here which can exclusively take over the underlying
309  * PWM channel.
310  */
311 static int pca9685_pwm_gpio_probe(struct pwm_chip *chip)
312 {
313 	struct pca9685 *pca = to_pca(chip);
314 	struct device *dev = pwmchip_parent(chip);
315 
316 	pca->gpio.label = dev_name(dev);
317 	pca->gpio.parent = dev;
318 	pca->gpio.request = pca9685_pwm_gpio_request;
319 	pca->gpio.free = pca9685_pwm_gpio_free;
320 	pca->gpio.get_direction = pca9685_pwm_gpio_get_direction;
321 	pca->gpio.direction_input = pca9685_pwm_gpio_direction_input;
322 	pca->gpio.direction_output = pca9685_pwm_gpio_direction_output;
323 	pca->gpio.get = pca9685_pwm_gpio_get;
324 	pca->gpio.set = pca9685_pwm_gpio_set;
325 	pca->gpio.base = -1;
326 	pca->gpio.ngpio = PCA9685_MAXCHAN;
327 	pca->gpio.can_sleep = true;
328 
329 	return devm_gpiochip_add_data(dev, &pca->gpio, chip);
330 }
331 #else
332 static inline bool pca9685_pwm_test_and_set_inuse(struct pca9685 *pca,
333 						  int pwm_idx)
334 {
335 	return false;
336 }
337 
338 static inline void
339 pca9685_pwm_clear_inuse(struct pca9685 *pca, int pwm_idx)
340 {
341 }
342 
343 static inline int pca9685_pwm_gpio_probe(struct pwm_chip *chip)
344 {
345 	return 0;
346 }
347 #endif
348 
349 static void pca9685_set_sleep_mode(struct pwm_chip *chip, bool enable)
350 {
351 	struct device *dev = pwmchip_parent(chip);
352 	struct pca9685 *pca = to_pca(chip);
353 	int err = regmap_update_bits(pca->regmap, PCA9685_MODE1,
354 				     MODE1_SLEEP, enable ? MODE1_SLEEP : 0);
355 	if (err) {
356 		dev_err(dev, "regmap_update_bits of register 0x%x failed: %pe\n",
357 			PCA9685_MODE1, ERR_PTR(err));
358 		return;
359 	}
360 
361 	if (!enable) {
362 		/* Wait 500us for the oscillator to be back up */
363 		udelay(500);
364 	}
365 }
366 
367 static int __pca9685_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
368 			       const struct pwm_state *state)
369 {
370 	struct pca9685 *pca = to_pca(chip);
371 	unsigned long long duty, prescale;
372 	unsigned int val = 0;
373 
374 	if (state->polarity != PWM_POLARITY_NORMAL)
375 		return -EINVAL;
376 
377 	prescale = DIV_ROUND_CLOSEST_ULL(PCA9685_OSC_CLOCK_MHZ * state->period,
378 					 PCA9685_COUNTER_RANGE * 1000) - 1;
379 	if (prescale < PCA9685_PRESCALE_MIN || prescale > PCA9685_PRESCALE_MAX) {
380 		dev_err(pwmchip_parent(chip), "pwm not changed: period out of bounds!\n");
381 		return -EINVAL;
382 	}
383 
384 	if (!state->enabled) {
385 		pca9685_pwm_set_duty(chip, pwm->hwpwm, 0);
386 		return 0;
387 	}
388 
389 	pca9685_read_reg(chip, PCA9685_PRESCALE, &val);
390 	if (prescale != val) {
391 		if (!pca9685_prescaler_can_change(pca, pwm->hwpwm)) {
392 			dev_err(pwmchip_parent(chip),
393 				"pwm not changed: periods of enabled pwms must match!\n");
394 			return -EBUSY;
395 		}
396 
397 		/*
398 		 * Putting the chip briefly into SLEEP mode
399 		 * at this point won't interfere with the
400 		 * pm_runtime framework, because the pm_runtime
401 		 * state is guaranteed active here.
402 		 */
403 		/* Put chip into sleep mode */
404 		pca9685_set_sleep_mode(chip, true);
405 
406 		/* Change the chip-wide output frequency */
407 		pca9685_write_reg(chip, PCA9685_PRESCALE, prescale);
408 
409 		/* Wake the chip up */
410 		pca9685_set_sleep_mode(chip, false);
411 	}
412 
413 	duty = PCA9685_COUNTER_RANGE * state->duty_cycle;
414 	duty = DIV_ROUND_UP_ULL(duty, state->period);
415 	pca9685_pwm_set_duty(chip, pwm->hwpwm, duty);
416 	return 0;
417 }
418 
419 static int pca9685_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
420 			     const struct pwm_state *state)
421 {
422 	struct pca9685 *pca = to_pca(chip);
423 	int ret;
424 
425 	mutex_lock(&pca->lock);
426 	ret = __pca9685_pwm_apply(chip, pwm, state);
427 	if (ret == 0) {
428 		if (state->enabled)
429 			set_bit(pwm->hwpwm, pca->pwms_enabled);
430 		else
431 			clear_bit(pwm->hwpwm, pca->pwms_enabled);
432 	}
433 	mutex_unlock(&pca->lock);
434 
435 	return ret;
436 }
437 
438 static int pca9685_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
439 				 struct pwm_state *state)
440 {
441 	unsigned long long duty;
442 	unsigned int val = 0;
443 
444 	/* Calculate (chip-wide) period from prescale value */
445 	pca9685_read_reg(chip, PCA9685_PRESCALE, &val);
446 	/*
447 	 * PCA9685_OSC_CLOCK_MHZ is 25, i.e. an integer divider of 1000.
448 	 * The following calculation is therefore only a multiplication
449 	 * and we are not losing precision.
450 	 */
451 	state->period = (PCA9685_COUNTER_RANGE * 1000 / PCA9685_OSC_CLOCK_MHZ) *
452 			(val + 1);
453 
454 	/* The (per-channel) polarity is fixed */
455 	state->polarity = PWM_POLARITY_NORMAL;
456 
457 	if (pwm->hwpwm >= PCA9685_MAXCHAN) {
458 		/*
459 		 * The "all LEDs" channel does not support HW readout
460 		 * Return 0 and disabled for backwards compatibility
461 		 */
462 		state->duty_cycle = 0;
463 		state->enabled = false;
464 		return 0;
465 	}
466 
467 	state->enabled = true;
468 	duty = pca9685_pwm_get_duty(chip, pwm->hwpwm);
469 	state->duty_cycle = DIV_ROUND_DOWN_ULL(duty * state->period, PCA9685_COUNTER_RANGE);
470 
471 	return 0;
472 }
473 
474 static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
475 {
476 	struct pca9685 *pca = to_pca(chip);
477 
478 	if (pca9685_pwm_test_and_set_inuse(pca, pwm->hwpwm))
479 		return -EBUSY;
480 
481 	if (pwm->hwpwm < PCA9685_MAXCHAN) {
482 		/* PWMs - except the "all LEDs" channel - default to enabled */
483 		mutex_lock(&pca->lock);
484 		set_bit(pwm->hwpwm, pca->pwms_enabled);
485 		mutex_unlock(&pca->lock);
486 	}
487 
488 	pm_runtime_get_sync(pwmchip_parent(chip));
489 
490 	return 0;
491 }
492 
493 static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
494 {
495 	struct pca9685 *pca = to_pca(chip);
496 
497 	mutex_lock(&pca->lock);
498 	pca9685_pwm_set_duty(chip, pwm->hwpwm, 0);
499 	clear_bit(pwm->hwpwm, pca->pwms_enabled);
500 	mutex_unlock(&pca->lock);
501 
502 	pm_runtime_put(pwmchip_parent(chip));
503 	pca9685_pwm_clear_inuse(pca, pwm->hwpwm);
504 }
505 
506 static const struct pwm_ops pca9685_pwm_ops = {
507 	.apply = pca9685_pwm_apply,
508 	.get_state = pca9685_pwm_get_state,
509 	.request = pca9685_pwm_request,
510 	.free = pca9685_pwm_free,
511 };
512 
513 static const struct regmap_config pca9685_regmap_i2c_config = {
514 	.reg_bits = 8,
515 	.val_bits = 8,
516 	.max_register = PCA9685_NUMREGS,
517 	.cache_type = REGCACHE_NONE,
518 };
519 
520 static int pca9685_pwm_probe(struct i2c_client *client)
521 {
522 	struct pwm_chip *chip;
523 	struct pca9685 *pca;
524 	unsigned int reg;
525 	int ret;
526 
527 	/* Add an extra channel for ALL_LED */
528 	chip = devm_pwmchip_alloc(&client->dev, PCA9685_MAXCHAN + 1, sizeof(*pca));
529 	if (IS_ERR(chip))
530 		return PTR_ERR(chip);
531 	pca = to_pca(chip);
532 
533 	pca->regmap = devm_regmap_init_i2c(client, &pca9685_regmap_i2c_config);
534 	if (IS_ERR(pca->regmap)) {
535 		ret = PTR_ERR(pca->regmap);
536 		dev_err(&client->dev, "Failed to initialize register map: %d\n",
537 			ret);
538 		return ret;
539 	}
540 
541 	i2c_set_clientdata(client, chip);
542 
543 	mutex_init(&pca->lock);
544 
545 	ret = pca9685_read_reg(chip, PCA9685_MODE2, &reg);
546 	if (ret)
547 		return ret;
548 
549 	if (device_property_read_bool(&client->dev, "invert"))
550 		reg |= MODE2_INVRT;
551 	else
552 		reg &= ~MODE2_INVRT;
553 
554 	if (device_property_read_bool(&client->dev, "open-drain"))
555 		reg &= ~MODE2_OUTDRV;
556 	else
557 		reg |= MODE2_OUTDRV;
558 
559 	ret = pca9685_write_reg(chip, PCA9685_MODE2, reg);
560 	if (ret)
561 		return ret;
562 
563 	/* Disable all LED ALLCALL and SUBx addresses to avoid bus collisions */
564 	pca9685_read_reg(chip, PCA9685_MODE1, &reg);
565 	reg &= ~(MODE1_ALLCALL | MODE1_SUB1 | MODE1_SUB2 | MODE1_SUB3);
566 	pca9685_write_reg(chip, PCA9685_MODE1, reg);
567 
568 	/* Reset OFF/ON registers to POR default */
569 	pca9685_write_reg(chip, PCA9685_ALL_LED_OFF_L, 0);
570 	pca9685_write_reg(chip, PCA9685_ALL_LED_OFF_H, LED_FULL);
571 	pca9685_write_reg(chip, PCA9685_ALL_LED_ON_L, 0);
572 	pca9685_write_reg(chip, PCA9685_ALL_LED_ON_H, LED_FULL);
573 
574 	chip->ops = &pca9685_pwm_ops;
575 
576 	ret = pwmchip_add(chip);
577 	if (ret < 0)
578 		return ret;
579 
580 	ret = pca9685_pwm_gpio_probe(chip);
581 	if (ret < 0) {
582 		pwmchip_remove(chip);
583 		return ret;
584 	}
585 
586 	pm_runtime_enable(&client->dev);
587 
588 	if (pm_runtime_enabled(&client->dev)) {
589 		/*
590 		 * Although the chip comes out of power-up in the sleep state,
591 		 * we force it to sleep in case it was woken up before
592 		 */
593 		pca9685_set_sleep_mode(chip, true);
594 		pm_runtime_set_suspended(&client->dev);
595 	} else {
596 		/* Wake the chip up if runtime PM is disabled */
597 		pca9685_set_sleep_mode(chip, false);
598 	}
599 
600 	return 0;
601 }
602 
603 static void pca9685_pwm_remove(struct i2c_client *client)
604 {
605 	struct pwm_chip *chip = i2c_get_clientdata(client);
606 
607 	pwmchip_remove(chip);
608 
609 	if (!pm_runtime_enabled(&client->dev)) {
610 		/* Put chip in sleep state if runtime PM is disabled */
611 		pca9685_set_sleep_mode(chip, true);
612 	}
613 
614 	pm_runtime_disable(&client->dev);
615 }
616 
617 static int __maybe_unused pca9685_pwm_runtime_suspend(struct device *dev)
618 {
619 	struct i2c_client *client = to_i2c_client(dev);
620 	struct pwm_chip *chip = i2c_get_clientdata(client);
621 
622 	pca9685_set_sleep_mode(chip, true);
623 	return 0;
624 }
625 
626 static int __maybe_unused pca9685_pwm_runtime_resume(struct device *dev)
627 {
628 	struct i2c_client *client = to_i2c_client(dev);
629 	struct pwm_chip *chip = i2c_get_clientdata(client);
630 
631 	pca9685_set_sleep_mode(chip, false);
632 	return 0;
633 }
634 
635 static const struct i2c_device_id pca9685_id[] = {
636 	{ "pca9685" },
637 	{ /* sentinel */ }
638 };
639 MODULE_DEVICE_TABLE(i2c, pca9685_id);
640 
641 static const struct acpi_device_id pca9685_acpi_ids[] = {
642 	{ "INT3492", 0 },
643 	{ /* sentinel */ },
644 };
645 MODULE_DEVICE_TABLE(acpi, pca9685_acpi_ids);
646 
647 static const struct of_device_id pca9685_dt_ids[] = {
648 	{ .compatible = "nxp,pca9685-pwm", },
649 	{ /* sentinel */ }
650 };
651 MODULE_DEVICE_TABLE(of, pca9685_dt_ids);
652 
653 static const struct dev_pm_ops pca9685_pwm_pm = {
654 	SET_RUNTIME_PM_OPS(pca9685_pwm_runtime_suspend,
655 			   pca9685_pwm_runtime_resume, NULL)
656 };
657 
658 static struct i2c_driver pca9685_i2c_driver = {
659 	.driver = {
660 		.name = "pca9685-pwm",
661 		.acpi_match_table = pca9685_acpi_ids,
662 		.of_match_table = pca9685_dt_ids,
663 		.pm = &pca9685_pwm_pm,
664 	},
665 	.probe = pca9685_pwm_probe,
666 	.remove = pca9685_pwm_remove,
667 	.id_table = pca9685_id,
668 };
669 
670 module_i2c_driver(pca9685_i2c_driver);
671 
672 MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>");
673 MODULE_DESCRIPTION("PWM driver for PCA9685");
674 MODULE_LICENSE("GPL");
675