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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
78struct pca9685 {
79 struct pwm_chip chip;
80 struct regmap *regmap;
81 struct mutex lock;
82 DECLARE_BITMAP(pwms_enabled, PCA9685_MAXCHAN + 1);
83#if IS_ENABLED(CONFIG_GPIOLIB)
84 struct gpio_chip gpio;
85 DECLARE_BITMAP(pwms_inuse, PCA9685_MAXCHAN + 1);
86#endif
87};
88
89static inline struct pca9685 *to_pca(struct pwm_chip *chip)
90{
91 return container_of(chip, struct pca9685, chip);
92}
93
94/* This function is supposed to be called with the lock mutex held */
95static bool pca9685_prescaler_can_change(struct pca9685 *pca, int channel)
96{
97 /* No PWM enabled: Change allowed */
98 if (bitmap_empty(pca->pwms_enabled, PCA9685_MAXCHAN + 1))
99 return true;
100 /* More than one PWM enabled: Change not allowed */
101 if (bitmap_weight(pca->pwms_enabled, PCA9685_MAXCHAN + 1) > 1)
102 return false;
103 /*
104 * Only one PWM enabled: Change allowed if the PWM about to
105 * be changed is the one that is already enabled
106 */
107 return test_bit(channel, pca->pwms_enabled);
108}
109
110static int pca9685_read_reg(struct pca9685 *pca, unsigned int reg, unsigned int *val)
111{
112 struct device *dev = pca->chip.dev;
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
122static int pca9685_write_reg(struct pca9685 *pca, unsigned int reg, unsigned int val)
123{
124 struct device *dev = pca->chip.dev;
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%) */
135static void pca9685_pwm_set_duty(struct pca9685 *pca, int channel, unsigned int duty)
136{
137 struct pwm_device *pwm = &pca->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(pca, 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(pca, REG_ON_H(channel), LED_FULL);
147 pca9685_write_reg(pca, 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(pca, REG_ON_L(channel), on & 0xff);
168 pca9685_write_reg(pca, REG_ON_H(channel), (on >> 8) & 0xf);
169 /* Set OFF time (clears full OFF bit) */
170 pca9685_write_reg(pca, REG_OFF_L(channel), off & 0xff);
171 pca9685_write_reg(pca, REG_OFF_H(channel), (off >> 8) & 0xf);
172}
173
174static unsigned int pca9685_pwm_get_duty(struct pca9685 *pca, int channel)
175{
176 struct pwm_device *pwm = &pca->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(pca, 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(pca, 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(pca, 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(pca, 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)
211static 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);
236out:
237 mutex_unlock(&pca->lock);
238 return is_inuse;
239}
240
241static 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
248static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset)
249{
250 struct pca9685 *pca = gpiochip_get_data(gpio);
251
252 if (pca9685_pwm_test_and_set_inuse(pca, offset))
253 return -EBUSY;
254 pm_runtime_get_sync(pca->chip.dev);
255 return 0;
256}
257
258static int pca9685_pwm_gpio_get(struct gpio_chip *gpio, unsigned int offset)
259{
260 struct pca9685 *pca = gpiochip_get_data(gpio);
261
262 return pca9685_pwm_get_duty(pca, offset) != 0;
263}
264
265static void pca9685_pwm_gpio_set(struct gpio_chip *gpio, unsigned int offset,
266 int value)
267{
268 struct pca9685 *pca = gpiochip_get_data(gpio);
269
270 pca9685_pwm_set_duty(pca, offset, value ? PCA9685_COUNTER_RANGE : 0);
271}
272
273static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset)
274{
275 struct pca9685 *pca = gpiochip_get_data(gpio);
276
277 pca9685_pwm_set_duty(pca, offset, 0);
278 pm_runtime_put(pca->chip.dev);
279 pca9685_pwm_clear_inuse(pca, offset);
280}
281
282static int pca9685_pwm_gpio_get_direction(struct gpio_chip *chip,
283 unsigned int offset)
284{
285 /* Always out */
286 return GPIO_LINE_DIRECTION_OUT;
287}
288
289static int pca9685_pwm_gpio_direction_input(struct gpio_chip *gpio,
290 unsigned int offset)
291{
292 return -EINVAL;
293}
294
295static int pca9685_pwm_gpio_direction_output(struct gpio_chip *gpio,
296 unsigned int offset, int value)
297{
298 pca9685_pwm_gpio_set(gpio, offset, value);
299
300 return 0;
301}
302
303/*
304 * The PCA9685 has a bit for turning the PWM output full off or on. Some
305 * boards like Intel Galileo actually uses these as normal GPIOs so we
306 * expose a GPIO chip here which can exclusively take over the underlying
307 * PWM channel.
308 */
309static int pca9685_pwm_gpio_probe(struct pca9685 *pca)
310{
311 struct device *dev = pca->chip.dev;
312
313 pca->gpio.label = dev_name(dev);
314 pca->gpio.parent = dev;
315 pca->gpio.request = pca9685_pwm_gpio_request;
316 pca->gpio.free = pca9685_pwm_gpio_free;
317 pca->gpio.get_direction = pca9685_pwm_gpio_get_direction;
318 pca->gpio.direction_input = pca9685_pwm_gpio_direction_input;
319 pca->gpio.direction_output = pca9685_pwm_gpio_direction_output;
320 pca->gpio.get = pca9685_pwm_gpio_get;
321 pca->gpio.set = pca9685_pwm_gpio_set;
322 pca->gpio.base = -1;
323 pca->gpio.ngpio = PCA9685_MAXCHAN;
324 pca->gpio.can_sleep = true;
325
326 return devm_gpiochip_add_data(dev, &pca->gpio, pca);
327}
328#else
329static inline bool pca9685_pwm_test_and_set_inuse(struct pca9685 *pca,
330 int pwm_idx)
331{
332 return false;
333}
334
335static inline void
336pca9685_pwm_clear_inuse(struct pca9685 *pca, int pwm_idx)
337{
338}
339
340static inline int pca9685_pwm_gpio_probe(struct pca9685 *pca)
341{
342 return 0;
343}
344#endif
345
346static void pca9685_set_sleep_mode(struct pca9685 *pca, bool enable)
347{
348 struct device *dev = pca->chip.dev;
349 int err = regmap_update_bits(pca->regmap, PCA9685_MODE1,
350 MODE1_SLEEP, enable ? MODE1_SLEEP : 0);
351 if (err) {
352 dev_err(dev, "regmap_update_bits of register 0x%x failed: %pe\n",
353 PCA9685_MODE1, ERR_PTR(err));
354 return;
355 }
356
357 if (!enable) {
358 /* Wait 500us for the oscillator to be back up */
359 udelay(500);
360 }
361}
362
363static int __pca9685_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
364 const struct pwm_state *state)
365{
366 struct pca9685 *pca = to_pca(chip);
367 unsigned long long duty, prescale;
368 unsigned int val = 0;
369
370 if (state->polarity != PWM_POLARITY_NORMAL)
371 return -EINVAL;
372
373 prescale = DIV_ROUND_CLOSEST_ULL(PCA9685_OSC_CLOCK_MHZ * state->period,
374 PCA9685_COUNTER_RANGE * 1000) - 1;
375 if (prescale < PCA9685_PRESCALE_MIN || prescale > PCA9685_PRESCALE_MAX) {
376 dev_err(chip->dev, "pwm not changed: period out of bounds!\n");
377 return -EINVAL;
378 }
379
380 if (!state->enabled) {
381 pca9685_pwm_set_duty(pca, pwm->hwpwm, 0);
382 return 0;
383 }
384
385 pca9685_read_reg(pca, PCA9685_PRESCALE, &val);
386 if (prescale != val) {
387 if (!pca9685_prescaler_can_change(pca, pwm->hwpwm)) {
388 dev_err(chip->dev,
389 "pwm not changed: periods of enabled pwms must match!\n");
390 return -EBUSY;
391 }
392
393 /*
394 * Putting the chip briefly into SLEEP mode
395 * at this point won't interfere with the
396 * pm_runtime framework, because the pm_runtime
397 * state is guaranteed active here.
398 */
399 /* Put chip into sleep mode */
400 pca9685_set_sleep_mode(pca, true);
401
402 /* Change the chip-wide output frequency */
403 pca9685_write_reg(pca, PCA9685_PRESCALE, prescale);
404
405 /* Wake the chip up */
406 pca9685_set_sleep_mode(pca, false);
407 }
408
409 duty = PCA9685_COUNTER_RANGE * state->duty_cycle;
410 duty = DIV_ROUND_UP_ULL(duty, state->period);
411 pca9685_pwm_set_duty(pca, pwm->hwpwm, duty);
412 return 0;
413}
414
415static int pca9685_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
416 const struct pwm_state *state)
417{
418 struct pca9685 *pca = to_pca(chip);
419 int ret;
420
421 mutex_lock(&pca->lock);
422 ret = __pca9685_pwm_apply(chip, pwm, state);
423 if (ret == 0) {
424 if (state->enabled)
425 set_bit(pwm->hwpwm, pca->pwms_enabled);
426 else
427 clear_bit(pwm->hwpwm, pca->pwms_enabled);
428 }
429 mutex_unlock(&pca->lock);
430
431 return ret;
432}
433
434static int pca9685_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
435 struct pwm_state *state)
436{
437 struct pca9685 *pca = to_pca(chip);
438 unsigned long long duty;
439 unsigned int val = 0;
440
441 /* Calculate (chip-wide) period from prescale value */
442 pca9685_read_reg(pca, PCA9685_PRESCALE, &val);
443 /*
444 * PCA9685_OSC_CLOCK_MHZ is 25, i.e. an integer divider of 1000.
445 * The following calculation is therefore only a multiplication
446 * and we are not losing precision.
447 */
448 state->period = (PCA9685_COUNTER_RANGE * 1000 / PCA9685_OSC_CLOCK_MHZ) *
449 (val + 1);
450
451 /* The (per-channel) polarity is fixed */
452 state->polarity = PWM_POLARITY_NORMAL;
453
454 if (pwm->hwpwm >= PCA9685_MAXCHAN) {
455 /*
456 * The "all LEDs" channel does not support HW readout
457 * Return 0 and disabled for backwards compatibility
458 */
459 state->duty_cycle = 0;
460 state->enabled = false;
461 return 0;
462 }
463
464 state->enabled = true;
465 duty = pca9685_pwm_get_duty(pca, pwm->hwpwm);
466 state->duty_cycle = DIV_ROUND_DOWN_ULL(duty * state->period, PCA9685_COUNTER_RANGE);
467
468 return 0;
469}
470
471static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
472{
473 struct pca9685 *pca = to_pca(chip);
474
475 if (pca9685_pwm_test_and_set_inuse(pca, pwm->hwpwm))
476 return -EBUSY;
477
478 if (pwm->hwpwm < PCA9685_MAXCHAN) {
479 /* PWMs - except the "all LEDs" channel - default to enabled */
480 mutex_lock(&pca->lock);
481 set_bit(pwm->hwpwm, pca->pwms_enabled);
482 mutex_unlock(&pca->lock);
483 }
484
485 pm_runtime_get_sync(chip->dev);
486
487 return 0;
488}
489
490static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
491{
492 struct pca9685 *pca = to_pca(chip);
493
494 mutex_lock(&pca->lock);
495 pca9685_pwm_set_duty(pca, pwm->hwpwm, 0);
496 clear_bit(pwm->hwpwm, pca->pwms_enabled);
497 mutex_unlock(&pca->lock);
498
499 pm_runtime_put(chip->dev);
500 pca9685_pwm_clear_inuse(pca, pwm->hwpwm);
501}
502
503static const struct pwm_ops pca9685_pwm_ops = {
504 .apply = pca9685_pwm_apply,
505 .get_state = pca9685_pwm_get_state,
506 .request = pca9685_pwm_request,
507 .free = pca9685_pwm_free,
508 .owner = THIS_MODULE,
509};
510
511static const struct regmap_config pca9685_regmap_i2c_config = {
512 .reg_bits = 8,
513 .val_bits = 8,
514 .max_register = PCA9685_NUMREGS,
515 .cache_type = REGCACHE_NONE,
516};
517
518static int pca9685_pwm_probe(struct i2c_client *client)
519{
520 struct pca9685 *pca;
521 unsigned int reg;
522 int ret;
523
524 pca = devm_kzalloc(&client->dev, sizeof(*pca), GFP_KERNEL);
525 if (!pca)
526 return -ENOMEM;
527
528 pca->regmap = devm_regmap_init_i2c(client, &pca9685_regmap_i2c_config);
529 if (IS_ERR(pca->regmap)) {
530 ret = PTR_ERR(pca->regmap);
531 dev_err(&client->dev, "Failed to initialize register map: %d\n",
532 ret);
533 return ret;
534 }
535
536 i2c_set_clientdata(client, pca);
537
538 mutex_init(&pca->lock);
539
540 ret = pca9685_read_reg(pca, PCA9685_MODE2, ®);
541 if (ret)
542 return ret;
543
544 if (device_property_read_bool(&client->dev, "invert"))
545 reg |= MODE2_INVRT;
546 else
547 reg &= ~MODE2_INVRT;
548
549 if (device_property_read_bool(&client->dev, "open-drain"))
550 reg &= ~MODE2_OUTDRV;
551 else
552 reg |= MODE2_OUTDRV;
553
554 ret = pca9685_write_reg(pca, PCA9685_MODE2, reg);
555 if (ret)
556 return ret;
557
558 /* Disable all LED ALLCALL and SUBx addresses to avoid bus collisions */
559 pca9685_read_reg(pca, PCA9685_MODE1, ®);
560 reg &= ~(MODE1_ALLCALL | MODE1_SUB1 | MODE1_SUB2 | MODE1_SUB3);
561 pca9685_write_reg(pca, PCA9685_MODE1, reg);
562
563 /* Reset OFF/ON registers to POR default */
564 pca9685_write_reg(pca, PCA9685_ALL_LED_OFF_L, 0);
565 pca9685_write_reg(pca, PCA9685_ALL_LED_OFF_H, LED_FULL);
566 pca9685_write_reg(pca, PCA9685_ALL_LED_ON_L, 0);
567 pca9685_write_reg(pca, PCA9685_ALL_LED_ON_H, LED_FULL);
568
569 pca->chip.ops = &pca9685_pwm_ops;
570 /* Add an extra channel for ALL_LED */
571 pca->chip.npwm = PCA9685_MAXCHAN + 1;
572
573 pca->chip.dev = &client->dev;
574
575 ret = pwmchip_add(&pca->chip);
576 if (ret < 0)
577 return ret;
578
579 ret = pca9685_pwm_gpio_probe(pca);
580 if (ret < 0) {
581 pwmchip_remove(&pca->chip);
582 return ret;
583 }
584
585 pm_runtime_enable(&client->dev);
586
587 if (pm_runtime_enabled(&client->dev)) {
588 /*
589 * Although the chip comes out of power-up in the sleep state,
590 * we force it to sleep in case it was woken up before
591 */
592 pca9685_set_sleep_mode(pca, true);
593 pm_runtime_set_suspended(&client->dev);
594 } else {
595 /* Wake the chip up if runtime PM is disabled */
596 pca9685_set_sleep_mode(pca, false);
597 }
598
599 return 0;
600}
601
602static void pca9685_pwm_remove(struct i2c_client *client)
603{
604 struct pca9685 *pca = i2c_get_clientdata(client);
605
606 pwmchip_remove(&pca->chip);
607
608 if (!pm_runtime_enabled(&client->dev)) {
609 /* Put chip in sleep state if runtime PM is disabled */
610 pca9685_set_sleep_mode(pca, true);
611 }
612
613 pm_runtime_disable(&client->dev);
614}
615
616static int __maybe_unused pca9685_pwm_runtime_suspend(struct device *dev)
617{
618 struct i2c_client *client = to_i2c_client(dev);
619 struct pca9685 *pca = i2c_get_clientdata(client);
620
621 pca9685_set_sleep_mode(pca, true);
622 return 0;
623}
624
625static int __maybe_unused pca9685_pwm_runtime_resume(struct device *dev)
626{
627 struct i2c_client *client = to_i2c_client(dev);
628 struct pca9685 *pca = i2c_get_clientdata(client);
629
630 pca9685_set_sleep_mode(pca, false);
631 return 0;
632}
633
634static const struct i2c_device_id pca9685_id[] = {
635 { "pca9685", 0 },
636 { /* sentinel */ },
637};
638MODULE_DEVICE_TABLE(i2c, pca9685_id);
639
640#ifdef CONFIG_ACPI
641static const struct acpi_device_id pca9685_acpi_ids[] = {
642 { "INT3492", 0 },
643 { /* sentinel */ },
644};
645MODULE_DEVICE_TABLE(acpi, pca9685_acpi_ids);
646#endif
647
648#ifdef CONFIG_OF
649static const struct of_device_id pca9685_dt_ids[] = {
650 { .compatible = "nxp,pca9685-pwm", },
651 { /* sentinel */ }
652};
653MODULE_DEVICE_TABLE(of, pca9685_dt_ids);
654#endif
655
656static const struct dev_pm_ops pca9685_pwm_pm = {
657 SET_RUNTIME_PM_OPS(pca9685_pwm_runtime_suspend,
658 pca9685_pwm_runtime_resume, NULL)
659};
660
661static struct i2c_driver pca9685_i2c_driver = {
662 .driver = {
663 .name = "pca9685-pwm",
664 .acpi_match_table = ACPI_PTR(pca9685_acpi_ids),
665 .of_match_table = of_match_ptr(pca9685_dt_ids),
666 .pm = &pca9685_pwm_pm,
667 },
668 .probe_new = pca9685_pwm_probe,
669 .remove = pca9685_pwm_remove,
670 .id_table = pca9685_id,
671};
672
673module_i2c_driver(pca9685_i2c_driver);
674
675MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>");
676MODULE_DESCRIPTION("PWM driver for PCA9685");
677MODULE_LICENSE("GPL");
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, changing the period of
27 * one channel affects the period of all 16 PWM outputs!
28 * However, the ratio between each configured duty cycle and the chip-wide
29 * period remains constant, because the OFF time is set in proportion to the
30 * counter range.
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_DEFAULT_PERIOD 5000000 /* Default period_ns = 1/200 Hz */
55#define PCA9685_OSC_CLOCK_MHZ 25 /* Internal oscillator with 25 MHz */
56
57#define PCA9685_NUMREGS 0xFF
58#define PCA9685_MAXCHAN 0x10
59
60#define LED_FULL (1 << 4)
61#define MODE1_SLEEP (1 << 4)
62#define MODE2_INVRT (1 << 4)
63#define MODE2_OUTDRV (1 << 2)
64
65#define LED_N_ON_H(N) (PCA9685_LEDX_ON_H + (4 * (N)))
66#define LED_N_ON_L(N) (PCA9685_LEDX_ON_L + (4 * (N)))
67#define LED_N_OFF_H(N) (PCA9685_LEDX_OFF_H + (4 * (N)))
68#define LED_N_OFF_L(N) (PCA9685_LEDX_OFF_L + (4 * (N)))
69
70struct pca9685 {
71 struct pwm_chip chip;
72 struct regmap *regmap;
73 int period_ns;
74#if IS_ENABLED(CONFIG_GPIOLIB)
75 struct mutex lock;
76 struct gpio_chip gpio;
77 DECLARE_BITMAP(pwms_inuse, PCA9685_MAXCHAN + 1);
78#endif
79};
80
81static inline struct pca9685 *to_pca(struct pwm_chip *chip)
82{
83 return container_of(chip, struct pca9685, chip);
84}
85
86#if IS_ENABLED(CONFIG_GPIOLIB)
87static bool pca9685_pwm_test_and_set_inuse(struct pca9685 *pca, int pwm_idx)
88{
89 bool is_inuse;
90
91 mutex_lock(&pca->lock);
92 if (pwm_idx >= PCA9685_MAXCHAN) {
93 /*
94 * "all LEDs" channel:
95 * pretend already in use if any of the PWMs are requested
96 */
97 if (!bitmap_empty(pca->pwms_inuse, PCA9685_MAXCHAN)) {
98 is_inuse = true;
99 goto out;
100 }
101 } else {
102 /*
103 * regular channel:
104 * pretend already in use if the "all LEDs" channel is requested
105 */
106 if (test_bit(PCA9685_MAXCHAN, pca->pwms_inuse)) {
107 is_inuse = true;
108 goto out;
109 }
110 }
111 is_inuse = test_and_set_bit(pwm_idx, pca->pwms_inuse);
112out:
113 mutex_unlock(&pca->lock);
114 return is_inuse;
115}
116
117static void pca9685_pwm_clear_inuse(struct pca9685 *pca, int pwm_idx)
118{
119 mutex_lock(&pca->lock);
120 clear_bit(pwm_idx, pca->pwms_inuse);
121 mutex_unlock(&pca->lock);
122}
123
124static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset)
125{
126 struct pca9685 *pca = gpiochip_get_data(gpio);
127
128 if (pca9685_pwm_test_and_set_inuse(pca, offset))
129 return -EBUSY;
130 pm_runtime_get_sync(pca->chip.dev);
131 return 0;
132}
133
134static int pca9685_pwm_gpio_get(struct gpio_chip *gpio, unsigned int offset)
135{
136 struct pca9685 *pca = gpiochip_get_data(gpio);
137 struct pwm_device *pwm = &pca->chip.pwms[offset];
138 unsigned int value;
139
140 regmap_read(pca->regmap, LED_N_ON_H(pwm->hwpwm), &value);
141
142 return value & LED_FULL;
143}
144
145static void pca9685_pwm_gpio_set(struct gpio_chip *gpio, unsigned int offset,
146 int value)
147{
148 struct pca9685 *pca = gpiochip_get_data(gpio);
149 struct pwm_device *pwm = &pca->chip.pwms[offset];
150 unsigned int on = value ? LED_FULL : 0;
151
152 /* Clear both OFF registers */
153 regmap_write(pca->regmap, LED_N_OFF_L(pwm->hwpwm), 0);
154 regmap_write(pca->regmap, LED_N_OFF_H(pwm->hwpwm), 0);
155
156 /* Set the full ON bit */
157 regmap_write(pca->regmap, LED_N_ON_H(pwm->hwpwm), on);
158}
159
160static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset)
161{
162 struct pca9685 *pca = gpiochip_get_data(gpio);
163
164 pca9685_pwm_gpio_set(gpio, offset, 0);
165 pm_runtime_put(pca->chip.dev);
166 pca9685_pwm_clear_inuse(pca, offset);
167}
168
169static int pca9685_pwm_gpio_get_direction(struct gpio_chip *chip,
170 unsigned int offset)
171{
172 /* Always out */
173 return GPIO_LINE_DIRECTION_OUT;
174}
175
176static int pca9685_pwm_gpio_direction_input(struct gpio_chip *gpio,
177 unsigned int offset)
178{
179 return -EINVAL;
180}
181
182static int pca9685_pwm_gpio_direction_output(struct gpio_chip *gpio,
183 unsigned int offset, int value)
184{
185 pca9685_pwm_gpio_set(gpio, offset, value);
186
187 return 0;
188}
189
190/*
191 * The PCA9685 has a bit for turning the PWM output full off or on. Some
192 * boards like Intel Galileo actually uses these as normal GPIOs so we
193 * expose a GPIO chip here which can exclusively take over the underlying
194 * PWM channel.
195 */
196static int pca9685_pwm_gpio_probe(struct pca9685 *pca)
197{
198 struct device *dev = pca->chip.dev;
199
200 mutex_init(&pca->lock);
201
202 pca->gpio.label = dev_name(dev);
203 pca->gpio.parent = dev;
204 pca->gpio.request = pca9685_pwm_gpio_request;
205 pca->gpio.free = pca9685_pwm_gpio_free;
206 pca->gpio.get_direction = pca9685_pwm_gpio_get_direction;
207 pca->gpio.direction_input = pca9685_pwm_gpio_direction_input;
208 pca->gpio.direction_output = pca9685_pwm_gpio_direction_output;
209 pca->gpio.get = pca9685_pwm_gpio_get;
210 pca->gpio.set = pca9685_pwm_gpio_set;
211 pca->gpio.base = -1;
212 pca->gpio.ngpio = PCA9685_MAXCHAN;
213 pca->gpio.can_sleep = true;
214
215 return devm_gpiochip_add_data(dev, &pca->gpio, pca);
216}
217#else
218static inline bool pca9685_pwm_test_and_set_inuse(struct pca9685 *pca,
219 int pwm_idx)
220{
221 return false;
222}
223
224static inline void
225pca9685_pwm_clear_inuse(struct pca9685 *pca, int pwm_idx)
226{
227}
228
229static inline int pca9685_pwm_gpio_probe(struct pca9685 *pca)
230{
231 return 0;
232}
233#endif
234
235static void pca9685_set_sleep_mode(struct pca9685 *pca, bool enable)
236{
237 regmap_update_bits(pca->regmap, PCA9685_MODE1,
238 MODE1_SLEEP, enable ? MODE1_SLEEP : 0);
239 if (!enable) {
240 /* Wait 500us for the oscillator to be back up */
241 udelay(500);
242 }
243}
244
245static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
246 int duty_ns, int period_ns)
247{
248 struct pca9685 *pca = to_pca(chip);
249 unsigned long long duty;
250 unsigned int reg;
251 int prescale;
252
253 if (period_ns != pca->period_ns) {
254 prescale = DIV_ROUND_CLOSEST(PCA9685_OSC_CLOCK_MHZ * period_ns,
255 PCA9685_COUNTER_RANGE * 1000) - 1;
256
257 if (prescale >= PCA9685_PRESCALE_MIN &&
258 prescale <= PCA9685_PRESCALE_MAX) {
259 /*
260 * putting the chip briefly into SLEEP mode
261 * at this point won't interfere with the
262 * pm_runtime framework, because the pm_runtime
263 * state is guaranteed active here.
264 */
265 /* Put chip into sleep mode */
266 pca9685_set_sleep_mode(pca, true);
267
268 /* Change the chip-wide output frequency */
269 regmap_write(pca->regmap, PCA9685_PRESCALE, prescale);
270
271 /* Wake the chip up */
272 pca9685_set_sleep_mode(pca, false);
273
274 pca->period_ns = period_ns;
275 } else {
276 dev_err(chip->dev,
277 "prescaler not set: period out of bounds!\n");
278 return -EINVAL;
279 }
280 }
281
282 if (duty_ns < 1) {
283 if (pwm->hwpwm >= PCA9685_MAXCHAN)
284 reg = PCA9685_ALL_LED_OFF_H;
285 else
286 reg = LED_N_OFF_H(pwm->hwpwm);
287
288 regmap_write(pca->regmap, reg, LED_FULL);
289
290 return 0;
291 }
292
293 if (duty_ns == period_ns) {
294 /* Clear both OFF registers */
295 if (pwm->hwpwm >= PCA9685_MAXCHAN)
296 reg = PCA9685_ALL_LED_OFF_L;
297 else
298 reg = LED_N_OFF_L(pwm->hwpwm);
299
300 regmap_write(pca->regmap, reg, 0x0);
301
302 if (pwm->hwpwm >= PCA9685_MAXCHAN)
303 reg = PCA9685_ALL_LED_OFF_H;
304 else
305 reg = LED_N_OFF_H(pwm->hwpwm);
306
307 regmap_write(pca->regmap, reg, 0x0);
308
309 /* Set the full ON bit */
310 if (pwm->hwpwm >= PCA9685_MAXCHAN)
311 reg = PCA9685_ALL_LED_ON_H;
312 else
313 reg = LED_N_ON_H(pwm->hwpwm);
314
315 regmap_write(pca->regmap, reg, LED_FULL);
316
317 return 0;
318 }
319
320 duty = PCA9685_COUNTER_RANGE * (unsigned long long)duty_ns;
321 duty = DIV_ROUND_UP_ULL(duty, period_ns);
322
323 if (pwm->hwpwm >= PCA9685_MAXCHAN)
324 reg = PCA9685_ALL_LED_OFF_L;
325 else
326 reg = LED_N_OFF_L(pwm->hwpwm);
327
328 regmap_write(pca->regmap, reg, (int)duty & 0xff);
329
330 if (pwm->hwpwm >= PCA9685_MAXCHAN)
331 reg = PCA9685_ALL_LED_OFF_H;
332 else
333 reg = LED_N_OFF_H(pwm->hwpwm);
334
335 regmap_write(pca->regmap, reg, ((int)duty >> 8) & 0xf);
336
337 /* Clear the full ON bit, otherwise the set OFF time has no effect */
338 if (pwm->hwpwm >= PCA9685_MAXCHAN)
339 reg = PCA9685_ALL_LED_ON_H;
340 else
341 reg = LED_N_ON_H(pwm->hwpwm);
342
343 regmap_write(pca->regmap, reg, 0);
344
345 return 0;
346}
347
348static int pca9685_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
349{
350 struct pca9685 *pca = to_pca(chip);
351 unsigned int reg;
352
353 /*
354 * The PWM subsystem does not support a pre-delay.
355 * So, set the ON-timeout to 0
356 */
357 if (pwm->hwpwm >= PCA9685_MAXCHAN)
358 reg = PCA9685_ALL_LED_ON_L;
359 else
360 reg = LED_N_ON_L(pwm->hwpwm);
361
362 regmap_write(pca->regmap, reg, 0);
363
364 if (pwm->hwpwm >= PCA9685_MAXCHAN)
365 reg = PCA9685_ALL_LED_ON_H;
366 else
367 reg = LED_N_ON_H(pwm->hwpwm);
368
369 regmap_write(pca->regmap, reg, 0);
370
371 /*
372 * Clear the full-off bit.
373 * It has precedence over the others and must be off.
374 */
375 if (pwm->hwpwm >= PCA9685_MAXCHAN)
376 reg = PCA9685_ALL_LED_OFF_H;
377 else
378 reg = LED_N_OFF_H(pwm->hwpwm);
379
380 regmap_update_bits(pca->regmap, reg, LED_FULL, 0x0);
381
382 return 0;
383}
384
385static void pca9685_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
386{
387 struct pca9685 *pca = to_pca(chip);
388 unsigned int reg;
389
390 if (pwm->hwpwm >= PCA9685_MAXCHAN)
391 reg = PCA9685_ALL_LED_OFF_H;
392 else
393 reg = LED_N_OFF_H(pwm->hwpwm);
394
395 regmap_write(pca->regmap, reg, LED_FULL);
396
397 /* Clear the LED_OFF counter. */
398 if (pwm->hwpwm >= PCA9685_MAXCHAN)
399 reg = PCA9685_ALL_LED_OFF_L;
400 else
401 reg = LED_N_OFF_L(pwm->hwpwm);
402
403 regmap_write(pca->regmap, reg, 0x0);
404}
405
406static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
407{
408 struct pca9685 *pca = to_pca(chip);
409
410 if (pca9685_pwm_test_and_set_inuse(pca, pwm->hwpwm))
411 return -EBUSY;
412 pm_runtime_get_sync(chip->dev);
413
414 return 0;
415}
416
417static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
418{
419 struct pca9685 *pca = to_pca(chip);
420
421 pca9685_pwm_disable(chip, pwm);
422 pm_runtime_put(chip->dev);
423 pca9685_pwm_clear_inuse(pca, pwm->hwpwm);
424}
425
426static const struct pwm_ops pca9685_pwm_ops = {
427 .enable = pca9685_pwm_enable,
428 .disable = pca9685_pwm_disable,
429 .config = pca9685_pwm_config,
430 .request = pca9685_pwm_request,
431 .free = pca9685_pwm_free,
432 .owner = THIS_MODULE,
433};
434
435static const struct regmap_config pca9685_regmap_i2c_config = {
436 .reg_bits = 8,
437 .val_bits = 8,
438 .max_register = PCA9685_NUMREGS,
439 .cache_type = REGCACHE_NONE,
440};
441
442static int pca9685_pwm_probe(struct i2c_client *client,
443 const struct i2c_device_id *id)
444{
445 struct pca9685 *pca;
446 int ret;
447 int mode2;
448
449 pca = devm_kzalloc(&client->dev, sizeof(*pca), GFP_KERNEL);
450 if (!pca)
451 return -ENOMEM;
452
453 pca->regmap = devm_regmap_init_i2c(client, &pca9685_regmap_i2c_config);
454 if (IS_ERR(pca->regmap)) {
455 ret = PTR_ERR(pca->regmap);
456 dev_err(&client->dev, "Failed to initialize register map: %d\n",
457 ret);
458 return ret;
459 }
460 pca->period_ns = PCA9685_DEFAULT_PERIOD;
461
462 i2c_set_clientdata(client, pca);
463
464 regmap_read(pca->regmap, PCA9685_MODE2, &mode2);
465
466 if (device_property_read_bool(&client->dev, "invert"))
467 mode2 |= MODE2_INVRT;
468 else
469 mode2 &= ~MODE2_INVRT;
470
471 if (device_property_read_bool(&client->dev, "open-drain"))
472 mode2 &= ~MODE2_OUTDRV;
473 else
474 mode2 |= MODE2_OUTDRV;
475
476 regmap_write(pca->regmap, PCA9685_MODE2, mode2);
477
478 /* clear all "full off" bits */
479 regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0);
480 regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0);
481
482 pca->chip.ops = &pca9685_pwm_ops;
483 /* add an extra channel for ALL_LED */
484 pca->chip.npwm = PCA9685_MAXCHAN + 1;
485
486 pca->chip.dev = &client->dev;
487 pca->chip.base = -1;
488
489 ret = pwmchip_add(&pca->chip);
490 if (ret < 0)
491 return ret;
492
493 ret = pca9685_pwm_gpio_probe(pca);
494 if (ret < 0) {
495 pwmchip_remove(&pca->chip);
496 return ret;
497 }
498
499 /* the chip comes out of power-up in the active state */
500 pm_runtime_set_active(&client->dev);
501 /*
502 * enable will put the chip into suspend, which is what we
503 * want as all outputs are disabled at this point
504 */
505 pm_runtime_enable(&client->dev);
506
507 return 0;
508}
509
510static int pca9685_pwm_remove(struct i2c_client *client)
511{
512 struct pca9685 *pca = i2c_get_clientdata(client);
513 int ret;
514
515 ret = pwmchip_remove(&pca->chip);
516 if (ret)
517 return ret;
518 pm_runtime_disable(&client->dev);
519 return 0;
520}
521
522static int __maybe_unused pca9685_pwm_runtime_suspend(struct device *dev)
523{
524 struct i2c_client *client = to_i2c_client(dev);
525 struct pca9685 *pca = i2c_get_clientdata(client);
526
527 pca9685_set_sleep_mode(pca, true);
528 return 0;
529}
530
531static int __maybe_unused pca9685_pwm_runtime_resume(struct device *dev)
532{
533 struct i2c_client *client = to_i2c_client(dev);
534 struct pca9685 *pca = i2c_get_clientdata(client);
535
536 pca9685_set_sleep_mode(pca, false);
537 return 0;
538}
539
540static const struct i2c_device_id pca9685_id[] = {
541 { "pca9685", 0 },
542 { /* sentinel */ },
543};
544MODULE_DEVICE_TABLE(i2c, pca9685_id);
545
546#ifdef CONFIG_ACPI
547static const struct acpi_device_id pca9685_acpi_ids[] = {
548 { "INT3492", 0 },
549 { /* sentinel */ },
550};
551MODULE_DEVICE_TABLE(acpi, pca9685_acpi_ids);
552#endif
553
554#ifdef CONFIG_OF
555static const struct of_device_id pca9685_dt_ids[] = {
556 { .compatible = "nxp,pca9685-pwm", },
557 { /* sentinel */ }
558};
559MODULE_DEVICE_TABLE(of, pca9685_dt_ids);
560#endif
561
562static const struct dev_pm_ops pca9685_pwm_pm = {
563 SET_RUNTIME_PM_OPS(pca9685_pwm_runtime_suspend,
564 pca9685_pwm_runtime_resume, NULL)
565};
566
567static struct i2c_driver pca9685_i2c_driver = {
568 .driver = {
569 .name = "pca9685-pwm",
570 .acpi_match_table = ACPI_PTR(pca9685_acpi_ids),
571 .of_match_table = of_match_ptr(pca9685_dt_ids),
572 .pm = &pca9685_pwm_pm,
573 },
574 .probe = pca9685_pwm_probe,
575 .remove = pca9685_pwm_remove,
576 .id_table = pca9685_id,
577};
578
579module_i2c_driver(pca9685_i2c_driver);
580
581MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>");
582MODULE_DESCRIPTION("PWM driver for PCA9685");
583MODULE_LICENSE("GPL");