xref: /linux/drivers/pwm/pwm-pca9685.c (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
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/acpi.h>
12 #include <linux/gpio/driver.h>
13 #include <linux/i2c.h>
14 #include <linux/module.h>
15 #include <linux/mutex.h>
16 #include <linux/platform_device.h>
17 #include <linux/property.h>
18 #include <linux/pwm.h>
19 #include <linux/regmap.h>
20 #include <linux/slab.h>
21 #include <linux/delay.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/bitmap.h>
24 
25 /*
26  * Because the PCA9685 has only one prescaler per chip, only the first channel
27  * that is enabled is allowed to change the prescale register.
28  * PWM channels requested afterwards must use a period that results in the same
29  * prescale setting as the one set by the first requested channel.
30  * GPIOs do not count as enabled PWMs as they are not using the prescaler.
31  */
32 
33 #define PCA9685_MODE1		0x00
34 #define PCA9685_MODE2		0x01
35 #define PCA9685_SUBADDR1	0x02
36 #define PCA9685_SUBADDR2	0x03
37 #define PCA9685_SUBADDR3	0x04
38 #define PCA9685_ALLCALLADDR	0x05
39 #define PCA9685_LEDX_ON_L	0x06
40 #define PCA9685_LEDX_ON_H	0x07
41 #define PCA9685_LEDX_OFF_L	0x08
42 #define PCA9685_LEDX_OFF_H	0x09
43 
44 #define PCA9685_ALL_LED_ON_L	0xFA
45 #define PCA9685_ALL_LED_ON_H	0xFB
46 #define PCA9685_ALL_LED_OFF_L	0xFC
47 #define PCA9685_ALL_LED_OFF_H	0xFD
48 #define PCA9685_PRESCALE	0xFE
49 
50 #define PCA9685_PRESCALE_MIN	0x03	/* => max. frequency of 1526 Hz */
51 #define PCA9685_PRESCALE_MAX	0xFF	/* => min. frequency of 24 Hz */
52 
53 #define PCA9685_COUNTER_RANGE	4096
54 #define PCA9685_OSC_CLOCK_MHZ	25	/* Internal oscillator with 25 MHz */
55 
56 #define PCA9685_NUMREGS		0xFF
57 #define PCA9685_MAXCHAN		0x10
58 
59 #define LED_FULL		BIT(4)
60 #define MODE1_ALLCALL		BIT(0)
61 #define MODE1_SUB3		BIT(1)
62 #define MODE1_SUB2		BIT(2)
63 #define MODE1_SUB1		BIT(3)
64 #define MODE1_SLEEP		BIT(4)
65 #define MODE2_INVRT		BIT(4)
66 #define MODE2_OUTDRV		BIT(2)
67 
68 #define LED_N_ON_H(N)	(PCA9685_LEDX_ON_H + (4 * (N)))
69 #define LED_N_ON_L(N)	(PCA9685_LEDX_ON_L + (4 * (N)))
70 #define LED_N_OFF_H(N)	(PCA9685_LEDX_OFF_H + (4 * (N)))
71 #define LED_N_OFF_L(N)	(PCA9685_LEDX_OFF_L + (4 * (N)))
72 
73 #define REG_ON_H(C)	((C) >= PCA9685_MAXCHAN ? PCA9685_ALL_LED_ON_H : LED_N_ON_H((C)))
74 #define REG_ON_L(C)	((C) >= PCA9685_MAXCHAN ? PCA9685_ALL_LED_ON_L : LED_N_ON_L((C)))
75 #define REG_OFF_H(C)	((C) >= PCA9685_MAXCHAN ? PCA9685_ALL_LED_OFF_H : LED_N_OFF_H((C)))
76 #define REG_OFF_L(C)	((C) >= PCA9685_MAXCHAN ? PCA9685_ALL_LED_OFF_L : LED_N_OFF_L((C)))
77 
78 struct pca9685 {
79 	struct regmap *regmap;
80 	struct mutex lock;
81 	DECLARE_BITMAP(pwms_enabled, PCA9685_MAXCHAN + 1);
82 #if IS_ENABLED(CONFIG_GPIOLIB)
83 	struct gpio_chip gpio;
84 	DECLARE_BITMAP(pwms_inuse, PCA9685_MAXCHAN + 1);
85 #endif
86 };
87 
88 static inline struct pca9685 *to_pca(struct pwm_chip *chip)
89 {
90 	return pwmchip_get_drvdata(chip);
91 }
92 
93 /* This function is supposed to be called with the lock mutex held */
94 static bool pca9685_prescaler_can_change(struct pca9685 *pca, int channel)
95 {
96 	/* No PWM enabled: Change allowed */
97 	if (bitmap_empty(pca->pwms_enabled, PCA9685_MAXCHAN + 1))
98 		return true;
99 	/* More than one PWM enabled: Change not allowed */
100 	if (bitmap_weight(pca->pwms_enabled, PCA9685_MAXCHAN + 1) > 1)
101 		return false;
102 	/*
103 	 * Only one PWM enabled: Change allowed if the PWM about to
104 	 * be changed is the one that is already enabled
105 	 */
106 	return test_bit(channel, pca->pwms_enabled);
107 }
108 
109 static int pca9685_read_reg(struct pwm_chip *chip, unsigned int reg, unsigned int *val)
110 {
111 	struct pca9685 *pca = to_pca(chip);
112 	struct device *dev = pwmchip_parent(chip);
113 	int err;
114 
115 	err = regmap_read(pca->regmap, reg, val);
116 	if (err)
117 		dev_err(dev, "regmap_read of register 0x%x failed: %pe\n", reg, ERR_PTR(err));
118 
119 	return err;
120 }
121 
122 static int pca9685_write_reg(struct pwm_chip *chip, unsigned int reg, unsigned int val)
123 {
124 	struct pca9685 *pca = to_pca(chip);
125 	struct device *dev = pwmchip_parent(chip);
126 	int err;
127 
128 	err = regmap_write(pca->regmap, reg, val);
129 	if (err)
130 		dev_err(dev, "regmap_write to register 0x%x failed: %pe\n", reg, ERR_PTR(err));
131 
132 	return err;
133 }
134 
135 /* Helper function to set the duty cycle ratio to duty/4096 (e.g. duty=2048 -> 50%) */
136 static void pca9685_pwm_set_duty(struct pwm_chip *chip, int channel, unsigned int duty)
137 {
138 	struct pwm_device *pwm = &chip->pwms[channel];
139 	unsigned int on, off;
140 
141 	if (duty == 0) {
142 		/* Set the full OFF bit, which has the highest precedence */
143 		pca9685_write_reg(chip, REG_OFF_H(channel), LED_FULL);
144 		return;
145 	} else if (duty >= PCA9685_COUNTER_RANGE) {
146 		/* Set the full ON bit and clear the full OFF bit */
147 		pca9685_write_reg(chip, REG_ON_H(channel), LED_FULL);
148 		pca9685_write_reg(chip, REG_OFF_H(channel), 0);
149 		return;
150 	}
151 
152 
153 	if (pwm->state.usage_power && channel < PCA9685_MAXCHAN) {
154 		/*
155 		 * If usage_power is set, the pca9685 driver will phase shift
156 		 * the individual channels relative to their channel number.
157 		 * This improves EMI because the enabled channels no longer
158 		 * turn on at the same time, while still maintaining the
159 		 * configured duty cycle / power output.
160 		 */
161 		on = channel * PCA9685_COUNTER_RANGE / PCA9685_MAXCHAN;
162 	} else
163 		on = 0;
164 
165 	off = (on + duty) % PCA9685_COUNTER_RANGE;
166 
167 	/* Set ON time (clears full ON bit) */
168 	pca9685_write_reg(chip, REG_ON_L(channel), on & 0xff);
169 	pca9685_write_reg(chip, REG_ON_H(channel), (on >> 8) & 0xf);
170 	/* Set OFF time (clears full OFF bit) */
171 	pca9685_write_reg(chip, REG_OFF_L(channel), off & 0xff);
172 	pca9685_write_reg(chip, REG_OFF_H(channel), (off >> 8) & 0xf);
173 }
174 
175 static unsigned int pca9685_pwm_get_duty(struct pwm_chip *chip, int channel)
176 {
177 	struct pwm_device *pwm = &chip->pwms[channel];
178 	unsigned int off = 0, on = 0, val = 0;
179 
180 	if (WARN_ON(channel >= PCA9685_MAXCHAN)) {
181 		/* HW does not support reading state of "all LEDs" channel */
182 		return 0;
183 	}
184 
185 	pca9685_read_reg(chip, LED_N_OFF_H(channel), &off);
186 	if (off & LED_FULL) {
187 		/* Full OFF bit is set */
188 		return 0;
189 	}
190 
191 	pca9685_read_reg(chip, LED_N_ON_H(channel), &on);
192 	if (on & LED_FULL) {
193 		/* Full ON bit is set */
194 		return PCA9685_COUNTER_RANGE;
195 	}
196 
197 	pca9685_read_reg(chip, LED_N_OFF_L(channel), &val);
198 	off = ((off & 0xf) << 8) | (val & 0xff);
199 	if (!pwm->state.usage_power)
200 		return off;
201 
202 	/* Read ON register to calculate duty cycle of staggered output */
203 	if (pca9685_read_reg(chip, LED_N_ON_L(channel), &val)) {
204 		/* Reset val to 0 in case reading LED_N_ON_L failed */
205 		val = 0;
206 	}
207 	on = ((on & 0xf) << 8) | (val & 0xff);
208 	return (off - on) & (PCA9685_COUNTER_RANGE - 1);
209 }
210 
211 #if IS_ENABLED(CONFIG_GPIOLIB)
212 static bool pca9685_pwm_test_and_set_inuse(struct pca9685 *pca, int pwm_idx)
213 {
214 	bool is_inuse;
215 
216 	mutex_lock(&pca->lock);
217 	if (pwm_idx >= PCA9685_MAXCHAN) {
218 		/*
219 		 * "All LEDs" channel:
220 		 * pretend already in use if any of the PWMs are requested
221 		 */
222 		if (!bitmap_empty(pca->pwms_inuse, PCA9685_MAXCHAN)) {
223 			is_inuse = true;
224 			goto out;
225 		}
226 	} else {
227 		/*
228 		 * Regular channel:
229 		 * pretend already in use if the "all LEDs" channel is requested
230 		 */
231 		if (test_bit(PCA9685_MAXCHAN, pca->pwms_inuse)) {
232 			is_inuse = true;
233 			goto out;
234 		}
235 	}
236 	is_inuse = test_and_set_bit(pwm_idx, pca->pwms_inuse);
237 out:
238 	mutex_unlock(&pca->lock);
239 	return is_inuse;
240 }
241 
242 static void pca9685_pwm_clear_inuse(struct pca9685 *pca, int pwm_idx)
243 {
244 	mutex_lock(&pca->lock);
245 	clear_bit(pwm_idx, pca->pwms_inuse);
246 	mutex_unlock(&pca->lock);
247 }
248 
249 static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset)
250 {
251 	struct pwm_chip *chip = gpiochip_get_data(gpio);
252 	struct pca9685 *pca = to_pca(chip);
253 
254 	if (pca9685_pwm_test_and_set_inuse(pca, offset))
255 		return -EBUSY;
256 	pm_runtime_get_sync(pwmchip_parent(chip));
257 	return 0;
258 }
259 
260 static int pca9685_pwm_gpio_get(struct gpio_chip *gpio, unsigned int offset)
261 {
262 	struct pwm_chip *chip = gpiochip_get_data(gpio);
263 
264 	return pca9685_pwm_get_duty(chip, offset) != 0;
265 }
266 
267 static void pca9685_pwm_gpio_set(struct gpio_chip *gpio, unsigned int offset,
268 				 int value)
269 {
270 	struct pwm_chip *chip = gpiochip_get_data(gpio);
271 
272 	pca9685_pwm_set_duty(chip, offset, value ? PCA9685_COUNTER_RANGE : 0);
273 }
274 
275 static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset)
276 {
277 	struct pwm_chip *chip = gpiochip_get_data(gpio);
278 	struct pca9685 *pca = to_pca(chip);
279 
280 	pca9685_pwm_set_duty(chip, offset, 0);
281 	pm_runtime_put(pwmchip_parent(chip));
282 	pca9685_pwm_clear_inuse(pca, offset);
283 }
284 
285 static int pca9685_pwm_gpio_get_direction(struct gpio_chip *chip,
286 					  unsigned int offset)
287 {
288 	/* Always out */
289 	return GPIO_LINE_DIRECTION_OUT;
290 }
291 
292 static int pca9685_pwm_gpio_direction_input(struct gpio_chip *gpio,
293 					    unsigned int offset)
294 {
295 	return -EINVAL;
296 }
297 
298 static int pca9685_pwm_gpio_direction_output(struct gpio_chip *gpio,
299 					     unsigned int offset, int value)
300 {
301 	pca9685_pwm_gpio_set(gpio, offset, value);
302 
303 	return 0;
304 }
305 
306 /*
307  * The PCA9685 has a bit for turning the PWM output full off or on. Some
308  * boards like Intel Galileo actually uses these as normal GPIOs so we
309  * expose a GPIO chip here which can exclusively take over the underlying
310  * PWM channel.
311  */
312 static int pca9685_pwm_gpio_probe(struct pwm_chip *chip)
313 {
314 	struct pca9685 *pca = to_pca(chip);
315 	struct device *dev = pwmchip_parent(chip);
316 
317 	pca->gpio.label = dev_name(dev);
318 	pca->gpio.parent = dev;
319 	pca->gpio.request = pca9685_pwm_gpio_request;
320 	pca->gpio.free = pca9685_pwm_gpio_free;
321 	pca->gpio.get_direction = pca9685_pwm_gpio_get_direction;
322 	pca->gpio.direction_input = pca9685_pwm_gpio_direction_input;
323 	pca->gpio.direction_output = pca9685_pwm_gpio_direction_output;
324 	pca->gpio.get = pca9685_pwm_gpio_get;
325 	pca->gpio.set = pca9685_pwm_gpio_set;
326 	pca->gpio.base = -1;
327 	pca->gpio.ngpio = PCA9685_MAXCHAN;
328 	pca->gpio.can_sleep = true;
329 
330 	return devm_gpiochip_add_data(dev, &pca->gpio, chip);
331 }
332 #else
333 static inline bool pca9685_pwm_test_and_set_inuse(struct pca9685 *pca,
334 						  int pwm_idx)
335 {
336 	return false;
337 }
338 
339 static inline void
340 pca9685_pwm_clear_inuse(struct pca9685 *pca, int pwm_idx)
341 {
342 }
343 
344 static inline int pca9685_pwm_gpio_probe(struct pwm_chip *chip)
345 {
346 	return 0;
347 }
348 #endif
349 
350 static void pca9685_set_sleep_mode(struct pwm_chip *chip, bool enable)
351 {
352 	struct device *dev = pwmchip_parent(chip);
353 	struct pca9685 *pca = to_pca(chip);
354 	int err = regmap_update_bits(pca->regmap, PCA9685_MODE1,
355 				     MODE1_SLEEP, enable ? MODE1_SLEEP : 0);
356 	if (err) {
357 		dev_err(dev, "regmap_update_bits of register 0x%x failed: %pe\n",
358 			PCA9685_MODE1, ERR_PTR(err));
359 		return;
360 	}
361 
362 	if (!enable) {
363 		/* Wait 500us for the oscillator to be back up */
364 		udelay(500);
365 	}
366 }
367 
368 static int __pca9685_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
369 			       const struct pwm_state *state)
370 {
371 	struct pca9685 *pca = to_pca(chip);
372 	unsigned long long duty, prescale;
373 	unsigned int val = 0;
374 
375 	if (state->polarity != PWM_POLARITY_NORMAL)
376 		return -EINVAL;
377 
378 	prescale = DIV_ROUND_CLOSEST_ULL(PCA9685_OSC_CLOCK_MHZ * state->period,
379 					 PCA9685_COUNTER_RANGE * 1000) - 1;
380 	if (prescale < PCA9685_PRESCALE_MIN || prescale > PCA9685_PRESCALE_MAX) {
381 		dev_err(pwmchip_parent(chip), "pwm not changed: period out of bounds!\n");
382 		return -EINVAL;
383 	}
384 
385 	if (!state->enabled) {
386 		pca9685_pwm_set_duty(chip, pwm->hwpwm, 0);
387 		return 0;
388 	}
389 
390 	pca9685_read_reg(chip, PCA9685_PRESCALE, &val);
391 	if (prescale != val) {
392 		if (!pca9685_prescaler_can_change(pca, pwm->hwpwm)) {
393 			dev_err(pwmchip_parent(chip),
394 				"pwm not changed: periods of enabled pwms must match!\n");
395 			return -EBUSY;
396 		}
397 
398 		/*
399 		 * Putting the chip briefly into SLEEP mode
400 		 * at this point won't interfere with the
401 		 * pm_runtime framework, because the pm_runtime
402 		 * state is guaranteed active here.
403 		 */
404 		/* Put chip into sleep mode */
405 		pca9685_set_sleep_mode(chip, true);
406 
407 		/* Change the chip-wide output frequency */
408 		pca9685_write_reg(chip, PCA9685_PRESCALE, prescale);
409 
410 		/* Wake the chip up */
411 		pca9685_set_sleep_mode(chip, false);
412 	}
413 
414 	duty = PCA9685_COUNTER_RANGE * state->duty_cycle;
415 	duty = DIV_ROUND_UP_ULL(duty, state->period);
416 	pca9685_pwm_set_duty(chip, pwm->hwpwm, duty);
417 	return 0;
418 }
419 
420 static int pca9685_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
421 			     const struct pwm_state *state)
422 {
423 	struct pca9685 *pca = to_pca(chip);
424 	int ret;
425 
426 	mutex_lock(&pca->lock);
427 	ret = __pca9685_pwm_apply(chip, pwm, state);
428 	if (ret == 0) {
429 		if (state->enabled)
430 			set_bit(pwm->hwpwm, pca->pwms_enabled);
431 		else
432 			clear_bit(pwm->hwpwm, pca->pwms_enabled);
433 	}
434 	mutex_unlock(&pca->lock);
435 
436 	return ret;
437 }
438 
439 static int pca9685_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
440 				 struct pwm_state *state)
441 {
442 	unsigned long long duty;
443 	unsigned int val = 0;
444 
445 	/* Calculate (chip-wide) period from prescale value */
446 	pca9685_read_reg(chip, PCA9685_PRESCALE, &val);
447 	/*
448 	 * PCA9685_OSC_CLOCK_MHZ is 25, i.e. an integer divider of 1000.
449 	 * The following calculation is therefore only a multiplication
450 	 * and we are not losing precision.
451 	 */
452 	state->period = (PCA9685_COUNTER_RANGE * 1000 / PCA9685_OSC_CLOCK_MHZ) *
453 			(val + 1);
454 
455 	/* The (per-channel) polarity is fixed */
456 	state->polarity = PWM_POLARITY_NORMAL;
457 
458 	if (pwm->hwpwm >= PCA9685_MAXCHAN) {
459 		/*
460 		 * The "all LEDs" channel does not support HW readout
461 		 * Return 0 and disabled for backwards compatibility
462 		 */
463 		state->duty_cycle = 0;
464 		state->enabled = false;
465 		return 0;
466 	}
467 
468 	state->enabled = true;
469 	duty = pca9685_pwm_get_duty(chip, pwm->hwpwm);
470 	state->duty_cycle = DIV_ROUND_DOWN_ULL(duty * state->period, PCA9685_COUNTER_RANGE);
471 
472 	return 0;
473 }
474 
475 static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
476 {
477 	struct pca9685 *pca = to_pca(chip);
478 
479 	if (pca9685_pwm_test_and_set_inuse(pca, pwm->hwpwm))
480 		return -EBUSY;
481 
482 	if (pwm->hwpwm < PCA9685_MAXCHAN) {
483 		/* PWMs - except the "all LEDs" channel - default to enabled */
484 		mutex_lock(&pca->lock);
485 		set_bit(pwm->hwpwm, pca->pwms_enabled);
486 		mutex_unlock(&pca->lock);
487 	}
488 
489 	pm_runtime_get_sync(pwmchip_parent(chip));
490 
491 	return 0;
492 }
493 
494 static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
495 {
496 	struct pca9685 *pca = to_pca(chip);
497 
498 	mutex_lock(&pca->lock);
499 	pca9685_pwm_set_duty(chip, pwm->hwpwm, 0);
500 	clear_bit(pwm->hwpwm, pca->pwms_enabled);
501 	mutex_unlock(&pca->lock);
502 
503 	pm_runtime_put(pwmchip_parent(chip));
504 	pca9685_pwm_clear_inuse(pca, pwm->hwpwm);
505 }
506 
507 static const struct pwm_ops pca9685_pwm_ops = {
508 	.apply = pca9685_pwm_apply,
509 	.get_state = pca9685_pwm_get_state,
510 	.request = pca9685_pwm_request,
511 	.free = pca9685_pwm_free,
512 };
513 
514 static const struct regmap_config pca9685_regmap_i2c_config = {
515 	.reg_bits = 8,
516 	.val_bits = 8,
517 	.max_register = PCA9685_NUMREGS,
518 	.cache_type = REGCACHE_NONE,
519 };
520 
521 static int pca9685_pwm_probe(struct i2c_client *client)
522 {
523 	struct pwm_chip *chip;
524 	struct pca9685 *pca;
525 	unsigned int reg;
526 	int ret;
527 
528 	/* Add an extra channel for ALL_LED */
529 	chip = devm_pwmchip_alloc(&client->dev, PCA9685_MAXCHAN + 1, sizeof(*pca));
530 	if (IS_ERR(chip))
531 		return PTR_ERR(chip);
532 	pca = to_pca(chip);
533 
534 	pca->regmap = devm_regmap_init_i2c(client, &pca9685_regmap_i2c_config);
535 	if (IS_ERR(pca->regmap)) {
536 		ret = PTR_ERR(pca->regmap);
537 		dev_err(&client->dev, "Failed to initialize register map: %d\n",
538 			ret);
539 		return ret;
540 	}
541 
542 	i2c_set_clientdata(client, chip);
543 
544 	mutex_init(&pca->lock);
545 
546 	ret = pca9685_read_reg(chip, PCA9685_MODE2, &reg);
547 	if (ret)
548 		return ret;
549 
550 	if (device_property_read_bool(&client->dev, "invert"))
551 		reg |= MODE2_INVRT;
552 	else
553 		reg &= ~MODE2_INVRT;
554 
555 	if (device_property_read_bool(&client->dev, "open-drain"))
556 		reg &= ~MODE2_OUTDRV;
557 	else
558 		reg |= MODE2_OUTDRV;
559 
560 	ret = pca9685_write_reg(chip, PCA9685_MODE2, reg);
561 	if (ret)
562 		return ret;
563 
564 	/* Disable all LED ALLCALL and SUBx addresses to avoid bus collisions */
565 	pca9685_read_reg(chip, PCA9685_MODE1, &reg);
566 	reg &= ~(MODE1_ALLCALL | MODE1_SUB1 | MODE1_SUB2 | MODE1_SUB3);
567 	pca9685_write_reg(chip, PCA9685_MODE1, reg);
568 
569 	/* Reset OFF/ON registers to POR default */
570 	pca9685_write_reg(chip, PCA9685_ALL_LED_OFF_L, 0);
571 	pca9685_write_reg(chip, PCA9685_ALL_LED_OFF_H, LED_FULL);
572 	pca9685_write_reg(chip, PCA9685_ALL_LED_ON_L, 0);
573 	pca9685_write_reg(chip, PCA9685_ALL_LED_ON_H, LED_FULL);
574 
575 	chip->ops = &pca9685_pwm_ops;
576 
577 	ret = pwmchip_add(chip);
578 	if (ret < 0)
579 		return ret;
580 
581 	ret = pca9685_pwm_gpio_probe(chip);
582 	if (ret < 0) {
583 		pwmchip_remove(chip);
584 		return ret;
585 	}
586 
587 	pm_runtime_enable(&client->dev);
588 
589 	if (pm_runtime_enabled(&client->dev)) {
590 		/*
591 		 * Although the chip comes out of power-up in the sleep state,
592 		 * we force it to sleep in case it was woken up before
593 		 */
594 		pca9685_set_sleep_mode(chip, true);
595 		pm_runtime_set_suspended(&client->dev);
596 	} else {
597 		/* Wake the chip up if runtime PM is disabled */
598 		pca9685_set_sleep_mode(chip, false);
599 	}
600 
601 	return 0;
602 }
603 
604 static void pca9685_pwm_remove(struct i2c_client *client)
605 {
606 	struct pwm_chip *chip = i2c_get_clientdata(client);
607 
608 	pwmchip_remove(chip);
609 
610 	if (!pm_runtime_enabled(&client->dev)) {
611 		/* Put chip in sleep state if runtime PM is disabled */
612 		pca9685_set_sleep_mode(chip, true);
613 	}
614 
615 	pm_runtime_disable(&client->dev);
616 }
617 
618 static int __maybe_unused pca9685_pwm_runtime_suspend(struct device *dev)
619 {
620 	struct i2c_client *client = to_i2c_client(dev);
621 	struct pwm_chip *chip = i2c_get_clientdata(client);
622 
623 	pca9685_set_sleep_mode(chip, true);
624 	return 0;
625 }
626 
627 static int __maybe_unused pca9685_pwm_runtime_resume(struct device *dev)
628 {
629 	struct i2c_client *client = to_i2c_client(dev);
630 	struct pwm_chip *chip = i2c_get_clientdata(client);
631 
632 	pca9685_set_sleep_mode(chip, false);
633 	return 0;
634 }
635 
636 static const struct i2c_device_id pca9685_id[] = {
637 	{ "pca9685", 0 },
638 	{ /* sentinel */ },
639 };
640 MODULE_DEVICE_TABLE(i2c, pca9685_id);
641 
642 #ifdef CONFIG_ACPI
643 static const struct acpi_device_id pca9685_acpi_ids[] = {
644 	{ "INT3492", 0 },
645 	{ /* sentinel */ },
646 };
647 MODULE_DEVICE_TABLE(acpi, pca9685_acpi_ids);
648 #endif
649 
650 #ifdef CONFIG_OF
651 static const struct of_device_id pca9685_dt_ids[] = {
652 	{ .compatible = "nxp,pca9685-pwm", },
653 	{ /* sentinel */ }
654 };
655 MODULE_DEVICE_TABLE(of, pca9685_dt_ids);
656 #endif
657 
658 static const struct dev_pm_ops pca9685_pwm_pm = {
659 	SET_RUNTIME_PM_OPS(pca9685_pwm_runtime_suspend,
660 			   pca9685_pwm_runtime_resume, NULL)
661 };
662 
663 static struct i2c_driver pca9685_i2c_driver = {
664 	.driver = {
665 		.name = "pca9685-pwm",
666 		.acpi_match_table = ACPI_PTR(pca9685_acpi_ids),
667 		.of_match_table = of_match_ptr(pca9685_dt_ids),
668 		.pm = &pca9685_pwm_pm,
669 	},
670 	.probe = pca9685_pwm_probe,
671 	.remove = pca9685_pwm_remove,
672 	.id_table = pca9685_id,
673 };
674 
675 module_i2c_driver(pca9685_i2c_driver);
676 
677 MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>");
678 MODULE_DESCRIPTION("PWM driver for PCA9685");
679 MODULE_LICENSE("GPL");
680