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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/*
2 * Driver for PCA9685 16-channel 12-bit PWM LED controller
3 *
4 * Copyright (C) 2013 Steffen Trumtrar <s.trumtrar@pengutronix.de>
5 * Copyright (C) 2015 Clemens Gruber <clemens.gruber@pqgruber.com>
6 *
7 * based on the pwm-twl-led.c driver
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License version 2 as published by
11 * the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful, but WITHOUT
14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 * more details.
17 *
18 * You should have received a copy of the GNU General Public License along with
19 * this program. If not, see <http://www.gnu.org/licenses/>.
20 */
21
22#include <linux/acpi.h>
23#include <linux/gpio/driver.h>
24#include <linux/i2c.h>
25#include <linux/module.h>
26#include <linux/mutex.h>
27#include <linux/platform_device.h>
28#include <linux/property.h>
29#include <linux/pwm.h>
30#include <linux/regmap.h>
31#include <linux/slab.h>
32#include <linux/delay.h>
33#include <linux/pm_runtime.h>
34
35/*
36 * Because the PCA9685 has only one prescaler per chip, changing the period of
37 * one channel affects the period of all 16 PWM outputs!
38 * However, the ratio between each configured duty cycle and the chip-wide
39 * period remains constant, because the OFF time is set in proportion to the
40 * counter range.
41 */
42
43#define PCA9685_MODE1 0x00
44#define PCA9685_MODE2 0x01
45#define PCA9685_SUBADDR1 0x02
46#define PCA9685_SUBADDR2 0x03
47#define PCA9685_SUBADDR3 0x04
48#define PCA9685_ALLCALLADDR 0x05
49#define PCA9685_LEDX_ON_L 0x06
50#define PCA9685_LEDX_ON_H 0x07
51#define PCA9685_LEDX_OFF_L 0x08
52#define PCA9685_LEDX_OFF_H 0x09
53
54#define PCA9685_ALL_LED_ON_L 0xFA
55#define PCA9685_ALL_LED_ON_H 0xFB
56#define PCA9685_ALL_LED_OFF_L 0xFC
57#define PCA9685_ALL_LED_OFF_H 0xFD
58#define PCA9685_PRESCALE 0xFE
59
60#define PCA9685_PRESCALE_MIN 0x03 /* => max. frequency of 1526 Hz */
61#define PCA9685_PRESCALE_MAX 0xFF /* => min. frequency of 24 Hz */
62
63#define PCA9685_COUNTER_RANGE 4096
64#define PCA9685_DEFAULT_PERIOD 5000000 /* Default period_ns = 1/200 Hz */
65#define PCA9685_OSC_CLOCK_MHZ 25 /* Internal oscillator with 25 MHz */
66
67#define PCA9685_NUMREGS 0xFF
68#define PCA9685_MAXCHAN 0x10
69
70#define LED_FULL (1 << 4)
71#define MODE1_SLEEP (1 << 4)
72#define MODE2_INVRT (1 << 4)
73#define MODE2_OUTDRV (1 << 2)
74
75#define LED_N_ON_H(N) (PCA9685_LEDX_ON_H + (4 * (N)))
76#define LED_N_ON_L(N) (PCA9685_LEDX_ON_L + (4 * (N)))
77#define LED_N_OFF_H(N) (PCA9685_LEDX_OFF_H + (4 * (N)))
78#define LED_N_OFF_L(N) (PCA9685_LEDX_OFF_L + (4 * (N)))
79
80struct pca9685 {
81 struct pwm_chip chip;
82 struct regmap *regmap;
83 int duty_ns;
84 int period_ns;
85#if IS_ENABLED(CONFIG_GPIOLIB)
86 struct mutex lock;
87 struct gpio_chip gpio;
88#endif
89};
90
91static inline struct pca9685 *to_pca(struct pwm_chip *chip)
92{
93 return container_of(chip, struct pca9685, chip);
94}
95
96#if IS_ENABLED(CONFIG_GPIOLIB)
97static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset)
98{
99 struct pca9685 *pca = gpiochip_get_data(gpio);
100 struct pwm_device *pwm;
101
102 mutex_lock(&pca->lock);
103
104 pwm = &pca->chip.pwms[offset];
105
106 if (pwm->flags & (PWMF_REQUESTED | PWMF_EXPORTED)) {
107 mutex_unlock(&pca->lock);
108 return -EBUSY;
109 }
110
111 pwm_set_chip_data(pwm, (void *)1);
112
113 mutex_unlock(&pca->lock);
114 pm_runtime_get_sync(pca->chip.dev);
115 return 0;
116}
117
118static bool pca9685_pwm_is_gpio(struct pca9685 *pca, struct pwm_device *pwm)
119{
120 bool is_gpio = false;
121
122 mutex_lock(&pca->lock);
123
124 if (pwm->hwpwm >= PCA9685_MAXCHAN) {
125 unsigned int i;
126
127 /*
128 * Check if any of the GPIOs are requested and in that case
129 * prevent using the "all LEDs" channel.
130 */
131 for (i = 0; i < pca->gpio.ngpio; i++)
132 if (gpiochip_is_requested(&pca->gpio, i)) {
133 is_gpio = true;
134 break;
135 }
136 } else if (pwm_get_chip_data(pwm)) {
137 is_gpio = true;
138 }
139
140 mutex_unlock(&pca->lock);
141 return is_gpio;
142}
143
144static int pca9685_pwm_gpio_get(struct gpio_chip *gpio, unsigned int offset)
145{
146 struct pca9685 *pca = gpiochip_get_data(gpio);
147 struct pwm_device *pwm = &pca->chip.pwms[offset];
148 unsigned int value;
149
150 regmap_read(pca->regmap, LED_N_ON_H(pwm->hwpwm), &value);
151
152 return value & LED_FULL;
153}
154
155static void pca9685_pwm_gpio_set(struct gpio_chip *gpio, unsigned int offset,
156 int value)
157{
158 struct pca9685 *pca = gpiochip_get_data(gpio);
159 struct pwm_device *pwm = &pca->chip.pwms[offset];
160 unsigned int on = value ? LED_FULL : 0;
161
162 /* Clear both OFF registers */
163 regmap_write(pca->regmap, LED_N_OFF_L(pwm->hwpwm), 0);
164 regmap_write(pca->regmap, LED_N_OFF_H(pwm->hwpwm), 0);
165
166 /* Set the full ON bit */
167 regmap_write(pca->regmap, LED_N_ON_H(pwm->hwpwm), on);
168}
169
170static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset)
171{
172 struct pca9685 *pca = gpiochip_get_data(gpio);
173 struct pwm_device *pwm;
174
175 pca9685_pwm_gpio_set(gpio, offset, 0);
176 pm_runtime_put(pca->chip.dev);
177 mutex_lock(&pca->lock);
178 pwm = &pca->chip.pwms[offset];
179 pwm_set_chip_data(pwm, NULL);
180 mutex_unlock(&pca->lock);
181}
182
183static int pca9685_pwm_gpio_get_direction(struct gpio_chip *chip,
184 unsigned int offset)
185{
186 /* Always out */
187 return 0;
188}
189
190static int pca9685_pwm_gpio_direction_input(struct gpio_chip *gpio,
191 unsigned int offset)
192{
193 return -EINVAL;
194}
195
196static int pca9685_pwm_gpio_direction_output(struct gpio_chip *gpio,
197 unsigned int offset, int value)
198{
199 pca9685_pwm_gpio_set(gpio, offset, value);
200
201 return 0;
202}
203
204/*
205 * The PCA9685 has a bit for turning the PWM output full off or on. Some
206 * boards like Intel Galileo actually uses these as normal GPIOs so we
207 * expose a GPIO chip here which can exclusively take over the underlying
208 * PWM channel.
209 */
210static int pca9685_pwm_gpio_probe(struct pca9685 *pca)
211{
212 struct device *dev = pca->chip.dev;
213
214 mutex_init(&pca->lock);
215
216 pca->gpio.label = dev_name(dev);
217 pca->gpio.parent = dev;
218 pca->gpio.request = pca9685_pwm_gpio_request;
219 pca->gpio.free = pca9685_pwm_gpio_free;
220 pca->gpio.get_direction = pca9685_pwm_gpio_get_direction;
221 pca->gpio.direction_input = pca9685_pwm_gpio_direction_input;
222 pca->gpio.direction_output = pca9685_pwm_gpio_direction_output;
223 pca->gpio.get = pca9685_pwm_gpio_get;
224 pca->gpio.set = pca9685_pwm_gpio_set;
225 pca->gpio.base = -1;
226 pca->gpio.ngpio = PCA9685_MAXCHAN;
227 pca->gpio.can_sleep = true;
228
229 return devm_gpiochip_add_data(dev, &pca->gpio, pca);
230}
231#else
232static inline bool pca9685_pwm_is_gpio(struct pca9685 *pca,
233 struct pwm_device *pwm)
234{
235 return false;
236}
237
238static inline int pca9685_pwm_gpio_probe(struct pca9685 *pca)
239{
240 return 0;
241}
242#endif
243
244static void pca9685_set_sleep_mode(struct pca9685 *pca, bool enable)
245{
246 regmap_update_bits(pca->regmap, PCA9685_MODE1,
247 MODE1_SLEEP, enable ? MODE1_SLEEP : 0);
248 if (!enable) {
249 /* Wait 500us for the oscillator to be back up */
250 udelay(500);
251 }
252}
253
254static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
255 int duty_ns, int period_ns)
256{
257 struct pca9685 *pca = to_pca(chip);
258 unsigned long long duty;
259 unsigned int reg;
260 int prescale;
261
262 if (period_ns != pca->period_ns) {
263 prescale = DIV_ROUND_CLOSEST(PCA9685_OSC_CLOCK_MHZ * period_ns,
264 PCA9685_COUNTER_RANGE * 1000) - 1;
265
266 if (prescale >= PCA9685_PRESCALE_MIN &&
267 prescale <= PCA9685_PRESCALE_MAX) {
268 /*
269 * putting the chip briefly into SLEEP mode
270 * at this point won't interfere with the
271 * pm_runtime framework, because the pm_runtime
272 * state is guaranteed active here.
273 */
274 /* Put chip into sleep mode */
275 pca9685_set_sleep_mode(pca, true);
276
277 /* Change the chip-wide output frequency */
278 regmap_write(pca->regmap, PCA9685_PRESCALE, prescale);
279
280 /* Wake the chip up */
281 pca9685_set_sleep_mode(pca, false);
282
283 pca->period_ns = period_ns;
284 } else {
285 dev_err(chip->dev,
286 "prescaler not set: period out of bounds!\n");
287 return -EINVAL;
288 }
289 }
290
291 pca->duty_ns = duty_ns;
292
293 if (duty_ns < 1) {
294 if (pwm->hwpwm >= PCA9685_MAXCHAN)
295 reg = PCA9685_ALL_LED_OFF_H;
296 else
297 reg = LED_N_OFF_H(pwm->hwpwm);
298
299 regmap_write(pca->regmap, reg, LED_FULL);
300
301 return 0;
302 }
303
304 if (duty_ns == period_ns) {
305 /* Clear both OFF registers */
306 if (pwm->hwpwm >= PCA9685_MAXCHAN)
307 reg = PCA9685_ALL_LED_OFF_L;
308 else
309 reg = LED_N_OFF_L(pwm->hwpwm);
310
311 regmap_write(pca->regmap, reg, 0x0);
312
313 if (pwm->hwpwm >= PCA9685_MAXCHAN)
314 reg = PCA9685_ALL_LED_OFF_H;
315 else
316 reg = LED_N_OFF_H(pwm->hwpwm);
317
318 regmap_write(pca->regmap, reg, 0x0);
319
320 /* Set the full ON bit */
321 if (pwm->hwpwm >= PCA9685_MAXCHAN)
322 reg = PCA9685_ALL_LED_ON_H;
323 else
324 reg = LED_N_ON_H(pwm->hwpwm);
325
326 regmap_write(pca->regmap, reg, LED_FULL);
327
328 return 0;
329 }
330
331 duty = PCA9685_COUNTER_RANGE * (unsigned long long)duty_ns;
332 duty = DIV_ROUND_UP_ULL(duty, period_ns);
333
334 if (pwm->hwpwm >= PCA9685_MAXCHAN)
335 reg = PCA9685_ALL_LED_OFF_L;
336 else
337 reg = LED_N_OFF_L(pwm->hwpwm);
338
339 regmap_write(pca->regmap, reg, (int)duty & 0xff);
340
341 if (pwm->hwpwm >= PCA9685_MAXCHAN)
342 reg = PCA9685_ALL_LED_OFF_H;
343 else
344 reg = LED_N_OFF_H(pwm->hwpwm);
345
346 regmap_write(pca->regmap, reg, ((int)duty >> 8) & 0xf);
347
348 /* Clear the full ON bit, otherwise the set OFF time has no effect */
349 if (pwm->hwpwm >= PCA9685_MAXCHAN)
350 reg = PCA9685_ALL_LED_ON_H;
351 else
352 reg = LED_N_ON_H(pwm->hwpwm);
353
354 regmap_write(pca->regmap, reg, 0);
355
356 return 0;
357}
358
359static int pca9685_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
360{
361 struct pca9685 *pca = to_pca(chip);
362 unsigned int reg;
363
364 /*
365 * The PWM subsystem does not support a pre-delay.
366 * So, set the ON-timeout to 0
367 */
368 if (pwm->hwpwm >= PCA9685_MAXCHAN)
369 reg = PCA9685_ALL_LED_ON_L;
370 else
371 reg = LED_N_ON_L(pwm->hwpwm);
372
373 regmap_write(pca->regmap, reg, 0);
374
375 if (pwm->hwpwm >= PCA9685_MAXCHAN)
376 reg = PCA9685_ALL_LED_ON_H;
377 else
378 reg = LED_N_ON_H(pwm->hwpwm);
379
380 regmap_write(pca->regmap, reg, 0);
381
382 /*
383 * Clear the full-off bit.
384 * It has precedence over the others and must be off.
385 */
386 if (pwm->hwpwm >= PCA9685_MAXCHAN)
387 reg = PCA9685_ALL_LED_OFF_H;
388 else
389 reg = LED_N_OFF_H(pwm->hwpwm);
390
391 regmap_update_bits(pca->regmap, reg, LED_FULL, 0x0);
392
393 return 0;
394}
395
396static void pca9685_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
397{
398 struct pca9685 *pca = to_pca(chip);
399 unsigned int reg;
400
401 if (pwm->hwpwm >= PCA9685_MAXCHAN)
402 reg = PCA9685_ALL_LED_OFF_H;
403 else
404 reg = LED_N_OFF_H(pwm->hwpwm);
405
406 regmap_write(pca->regmap, reg, LED_FULL);
407
408 /* Clear the LED_OFF counter. */
409 if (pwm->hwpwm >= PCA9685_MAXCHAN)
410 reg = PCA9685_ALL_LED_OFF_L;
411 else
412 reg = LED_N_OFF_L(pwm->hwpwm);
413
414 regmap_write(pca->regmap, reg, 0x0);
415}
416
417static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
418{
419 struct pca9685 *pca = to_pca(chip);
420
421 if (pca9685_pwm_is_gpio(pca, pwm))
422 return -EBUSY;
423 pm_runtime_get_sync(chip->dev);
424
425 return 0;
426}
427
428static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
429{
430 pca9685_pwm_disable(chip, pwm);
431 pm_runtime_put(chip->dev);
432}
433
434static const struct pwm_ops pca9685_pwm_ops = {
435 .enable = pca9685_pwm_enable,
436 .disable = pca9685_pwm_disable,
437 .config = pca9685_pwm_config,
438 .request = pca9685_pwm_request,
439 .free = pca9685_pwm_free,
440 .owner = THIS_MODULE,
441};
442
443static const struct regmap_config pca9685_regmap_i2c_config = {
444 .reg_bits = 8,
445 .val_bits = 8,
446 .max_register = PCA9685_NUMREGS,
447 .cache_type = REGCACHE_NONE,
448};
449
450static int pca9685_pwm_probe(struct i2c_client *client,
451 const struct i2c_device_id *id)
452{
453 struct pca9685 *pca;
454 int ret;
455 int mode2;
456
457 pca = devm_kzalloc(&client->dev, sizeof(*pca), GFP_KERNEL);
458 if (!pca)
459 return -ENOMEM;
460
461 pca->regmap = devm_regmap_init_i2c(client, &pca9685_regmap_i2c_config);
462 if (IS_ERR(pca->regmap)) {
463 ret = PTR_ERR(pca->regmap);
464 dev_err(&client->dev, "Failed to initialize register map: %d\n",
465 ret);
466 return ret;
467 }
468 pca->duty_ns = 0;
469 pca->period_ns = PCA9685_DEFAULT_PERIOD;
470
471 i2c_set_clientdata(client, pca);
472
473 regmap_read(pca->regmap, PCA9685_MODE2, &mode2);
474
475 if (device_property_read_bool(&client->dev, "invert"))
476 mode2 |= MODE2_INVRT;
477 else
478 mode2 &= ~MODE2_INVRT;
479
480 if (device_property_read_bool(&client->dev, "open-drain"))
481 mode2 &= ~MODE2_OUTDRV;
482 else
483 mode2 |= MODE2_OUTDRV;
484
485 regmap_write(pca->regmap, PCA9685_MODE2, mode2);
486
487 /* clear all "full off" bits */
488 regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0);
489 regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0);
490
491 pca->chip.ops = &pca9685_pwm_ops;
492 /* add an extra channel for ALL_LED */
493 pca->chip.npwm = PCA9685_MAXCHAN + 1;
494
495 pca->chip.dev = &client->dev;
496 pca->chip.base = -1;
497
498 ret = pwmchip_add(&pca->chip);
499 if (ret < 0)
500 return ret;
501
502 ret = pca9685_pwm_gpio_probe(pca);
503 if (ret < 0) {
504 pwmchip_remove(&pca->chip);
505 return ret;
506 }
507
508 /* the chip comes out of power-up in the active state */
509 pm_runtime_set_active(&client->dev);
510 /*
511 * enable will put the chip into suspend, which is what we
512 * want as all outputs are disabled at this point
513 */
514 pm_runtime_enable(&client->dev);
515
516 return 0;
517}
518
519static int pca9685_pwm_remove(struct i2c_client *client)
520{
521 struct pca9685 *pca = i2c_get_clientdata(client);
522 int ret;
523
524 ret = pwmchip_remove(&pca->chip);
525 if (ret)
526 return ret;
527 pm_runtime_disable(&client->dev);
528 return 0;
529}
530
531#ifdef CONFIG_PM
532static int pca9685_pwm_runtime_suspend(struct device *dev)
533{
534 struct i2c_client *client = to_i2c_client(dev);
535 struct pca9685 *pca = i2c_get_clientdata(client);
536
537 pca9685_set_sleep_mode(pca, true);
538 return 0;
539}
540
541static int pca9685_pwm_runtime_resume(struct device *dev)
542{
543 struct i2c_client *client = to_i2c_client(dev);
544 struct pca9685 *pca = i2c_get_clientdata(client);
545
546 pca9685_set_sleep_mode(pca, false);
547 return 0;
548}
549#endif
550
551static const struct i2c_device_id pca9685_id[] = {
552 { "pca9685", 0 },
553 { /* sentinel */ },
554};
555MODULE_DEVICE_TABLE(i2c, pca9685_id);
556
557#ifdef CONFIG_ACPI
558static const struct acpi_device_id pca9685_acpi_ids[] = {
559 { "INT3492", 0 },
560 { /* sentinel */ },
561};
562MODULE_DEVICE_TABLE(acpi, pca9685_acpi_ids);
563#endif
564
565#ifdef CONFIG_OF
566static const struct of_device_id pca9685_dt_ids[] = {
567 { .compatible = "nxp,pca9685-pwm", },
568 { /* sentinel */ }
569};
570MODULE_DEVICE_TABLE(of, pca9685_dt_ids);
571#endif
572
573static const struct dev_pm_ops pca9685_pwm_pm = {
574 SET_RUNTIME_PM_OPS(pca9685_pwm_runtime_suspend,
575 pca9685_pwm_runtime_resume, NULL)
576};
577
578static struct i2c_driver pca9685_i2c_driver = {
579 .driver = {
580 .name = "pca9685-pwm",
581 .acpi_match_table = ACPI_PTR(pca9685_acpi_ids),
582 .of_match_table = of_match_ptr(pca9685_dt_ids),
583 .pm = &pca9685_pwm_pm,
584 },
585 .probe = pca9685_pwm_probe,
586 .remove = pca9685_pwm_remove,
587 .id_table = pca9685_id,
588};
589
590module_i2c_driver(pca9685_i2c_driver);
591
592MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>");
593MODULE_DESCRIPTION("PWM driver for PCA9685");
594MODULE_LICENSE("GPL");