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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 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
88static 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 */
94static 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
109static 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
122static 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%) */
136static 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
175static 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)
212static 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);
237out:
238 mutex_unlock(&pca->lock);
239 return is_inuse;
240}
241
242static 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
249static 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
260static 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
267static 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
275static 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
285static 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
292static int pca9685_pwm_gpio_direction_input(struct gpio_chip *gpio,
293 unsigned int offset)
294{
295 return -EINVAL;
296}
297
298static 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 */
312static 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
333static inline bool pca9685_pwm_test_and_set_inuse(struct pca9685 *pca,
334 int pwm_idx)
335{
336 return false;
337}
338
339static inline void
340pca9685_pwm_clear_inuse(struct pca9685 *pca, int pwm_idx)
341{
342}
343
344static inline int pca9685_pwm_gpio_probe(struct pwm_chip *chip)
345{
346 return 0;
347}
348#endif
349
350static 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
368static 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
420static 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
439static 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
475static 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
494static 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
507static 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
514static 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
521static 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, ®);
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, ®);
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
604static 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
618static 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
627static 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
636static const struct i2c_device_id pca9685_id[] = {
637 { "pca9685", 0 },
638 { /* sentinel */ },
639};
640MODULE_DEVICE_TABLE(i2c, pca9685_id);
641
642#ifdef CONFIG_ACPI
643static const struct acpi_device_id pca9685_acpi_ids[] = {
644 { "INT3492", 0 },
645 { /* sentinel */ },
646};
647MODULE_DEVICE_TABLE(acpi, pca9685_acpi_ids);
648#endif
649
650#ifdef CONFIG_OF
651static const struct of_device_id pca9685_dt_ids[] = {
652 { .compatible = "nxp,pca9685-pwm", },
653 { /* sentinel */ }
654};
655MODULE_DEVICE_TABLE(of, pca9685_dt_ids);
656#endif
657
658static 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
663static 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
675module_i2c_driver(pca9685_i2c_driver);
676
677MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>");
678MODULE_DESCRIPTION("PWM driver for PCA9685");
679MODULE_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/i2c.h>
24#include <linux/module.h>
25#include <linux/platform_device.h>
26#include <linux/property.h>
27#include <linux/pwm.h>
28#include <linux/regmap.h>
29#include <linux/slab.h>
30#include <linux/delay.h>
31
32/*
33 * Because the PCA9685 has only one prescaler per chip, changing the period of
34 * one channel affects the period of all 16 PWM outputs!
35 * However, the ratio between each configured duty cycle and the chip-wide
36 * period remains constant, because the OFF time is set in proportion to the
37 * counter range.
38 */
39
40#define PCA9685_MODE1 0x00
41#define PCA9685_MODE2 0x01
42#define PCA9685_SUBADDR1 0x02
43#define PCA9685_SUBADDR2 0x03
44#define PCA9685_SUBADDR3 0x04
45#define PCA9685_ALLCALLADDR 0x05
46#define PCA9685_LEDX_ON_L 0x06
47#define PCA9685_LEDX_ON_H 0x07
48#define PCA9685_LEDX_OFF_L 0x08
49#define PCA9685_LEDX_OFF_H 0x09
50
51#define PCA9685_ALL_LED_ON_L 0xFA
52#define PCA9685_ALL_LED_ON_H 0xFB
53#define PCA9685_ALL_LED_OFF_L 0xFC
54#define PCA9685_ALL_LED_OFF_H 0xFD
55#define PCA9685_PRESCALE 0xFE
56
57#define PCA9685_PRESCALE_MIN 0x03 /* => max. frequency of 1526 Hz */
58#define PCA9685_PRESCALE_MAX 0xFF /* => min. frequency of 24 Hz */
59
60#define PCA9685_COUNTER_RANGE 4096
61#define PCA9685_DEFAULT_PERIOD 5000000 /* Default period_ns = 1/200 Hz */
62#define PCA9685_OSC_CLOCK_MHZ 25 /* Internal oscillator with 25 MHz */
63
64#define PCA9685_NUMREGS 0xFF
65#define PCA9685_MAXCHAN 0x10
66
67#define LED_FULL (1 << 4)
68#define MODE1_SLEEP (1 << 4)
69#define MODE2_INVRT (1 << 4)
70#define MODE2_OUTDRV (1 << 2)
71
72#define LED_N_ON_H(N) (PCA9685_LEDX_ON_H + (4 * (N)))
73#define LED_N_ON_L(N) (PCA9685_LEDX_ON_L + (4 * (N)))
74#define LED_N_OFF_H(N) (PCA9685_LEDX_OFF_H + (4 * (N)))
75#define LED_N_OFF_L(N) (PCA9685_LEDX_OFF_L + (4 * (N)))
76
77struct pca9685 {
78 struct pwm_chip chip;
79 struct regmap *regmap;
80 int active_cnt;
81 int duty_ns;
82 int period_ns;
83};
84
85static inline struct pca9685 *to_pca(struct pwm_chip *chip)
86{
87 return container_of(chip, struct pca9685, chip);
88}
89
90static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
91 int duty_ns, int period_ns)
92{
93 struct pca9685 *pca = to_pca(chip);
94 unsigned long long duty;
95 unsigned int reg;
96 int prescale;
97
98 if (period_ns != pca->period_ns) {
99 prescale = DIV_ROUND_CLOSEST(PCA9685_OSC_CLOCK_MHZ * period_ns,
100 PCA9685_COUNTER_RANGE * 1000) - 1;
101
102 if (prescale >= PCA9685_PRESCALE_MIN &&
103 prescale <= PCA9685_PRESCALE_MAX) {
104 /* Put chip into sleep mode */
105 regmap_update_bits(pca->regmap, PCA9685_MODE1,
106 MODE1_SLEEP, MODE1_SLEEP);
107
108 /* Change the chip-wide output frequency */
109 regmap_write(pca->regmap, PCA9685_PRESCALE, prescale);
110
111 /* Wake the chip up */
112 regmap_update_bits(pca->regmap, PCA9685_MODE1,
113 MODE1_SLEEP, 0x0);
114
115 /* Wait 500us for the oscillator to be back up */
116 udelay(500);
117
118 pca->period_ns = period_ns;
119 } else {
120 dev_err(chip->dev,
121 "prescaler not set: period out of bounds!\n");
122 return -EINVAL;
123 }
124 }
125
126 pca->duty_ns = duty_ns;
127
128 if (duty_ns < 1) {
129 if (pwm->hwpwm >= PCA9685_MAXCHAN)
130 reg = PCA9685_ALL_LED_OFF_H;
131 else
132 reg = LED_N_OFF_H(pwm->hwpwm);
133
134 regmap_write(pca->regmap, reg, LED_FULL);
135
136 return 0;
137 }
138
139 if (duty_ns == period_ns) {
140 /* Clear both OFF registers */
141 if (pwm->hwpwm >= PCA9685_MAXCHAN)
142 reg = PCA9685_ALL_LED_OFF_L;
143 else
144 reg = LED_N_OFF_L(pwm->hwpwm);
145
146 regmap_write(pca->regmap, reg, 0x0);
147
148 if (pwm->hwpwm >= PCA9685_MAXCHAN)
149 reg = PCA9685_ALL_LED_OFF_H;
150 else
151 reg = LED_N_OFF_H(pwm->hwpwm);
152
153 regmap_write(pca->regmap, reg, 0x0);
154
155 /* Set the full ON bit */
156 if (pwm->hwpwm >= PCA9685_MAXCHAN)
157 reg = PCA9685_ALL_LED_ON_H;
158 else
159 reg = LED_N_ON_H(pwm->hwpwm);
160
161 regmap_write(pca->regmap, reg, LED_FULL);
162
163 return 0;
164 }
165
166 duty = PCA9685_COUNTER_RANGE * (unsigned long long)duty_ns;
167 duty = DIV_ROUND_UP_ULL(duty, period_ns);
168
169 if (pwm->hwpwm >= PCA9685_MAXCHAN)
170 reg = PCA9685_ALL_LED_OFF_L;
171 else
172 reg = LED_N_OFF_L(pwm->hwpwm);
173
174 regmap_write(pca->regmap, reg, (int)duty & 0xff);
175
176 if (pwm->hwpwm >= PCA9685_MAXCHAN)
177 reg = PCA9685_ALL_LED_OFF_H;
178 else
179 reg = LED_N_OFF_H(pwm->hwpwm);
180
181 regmap_write(pca->regmap, reg, ((int)duty >> 8) & 0xf);
182
183 /* Clear the full ON bit, otherwise the set OFF time has no effect */
184 if (pwm->hwpwm >= PCA9685_MAXCHAN)
185 reg = PCA9685_ALL_LED_ON_H;
186 else
187 reg = LED_N_ON_H(pwm->hwpwm);
188
189 regmap_write(pca->regmap, reg, 0);
190
191 return 0;
192}
193
194static int pca9685_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
195{
196 struct pca9685 *pca = to_pca(chip);
197 unsigned int reg;
198
199 /*
200 * The PWM subsystem does not support a pre-delay.
201 * So, set the ON-timeout to 0
202 */
203 if (pwm->hwpwm >= PCA9685_MAXCHAN)
204 reg = PCA9685_ALL_LED_ON_L;
205 else
206 reg = LED_N_ON_L(pwm->hwpwm);
207
208 regmap_write(pca->regmap, reg, 0);
209
210 if (pwm->hwpwm >= PCA9685_MAXCHAN)
211 reg = PCA9685_ALL_LED_ON_H;
212 else
213 reg = LED_N_ON_H(pwm->hwpwm);
214
215 regmap_write(pca->regmap, reg, 0);
216
217 /*
218 * Clear the full-off bit.
219 * It has precedence over the others and must be off.
220 */
221 if (pwm->hwpwm >= PCA9685_MAXCHAN)
222 reg = PCA9685_ALL_LED_OFF_H;
223 else
224 reg = LED_N_OFF_H(pwm->hwpwm);
225
226 regmap_update_bits(pca->regmap, reg, LED_FULL, 0x0);
227
228 return 0;
229}
230
231static void pca9685_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
232{
233 struct pca9685 *pca = to_pca(chip);
234 unsigned int reg;
235
236 if (pwm->hwpwm >= PCA9685_MAXCHAN)
237 reg = PCA9685_ALL_LED_OFF_H;
238 else
239 reg = LED_N_OFF_H(pwm->hwpwm);
240
241 regmap_write(pca->regmap, reg, LED_FULL);
242
243 /* Clear the LED_OFF counter. */
244 if (pwm->hwpwm >= PCA9685_MAXCHAN)
245 reg = PCA9685_ALL_LED_OFF_L;
246 else
247 reg = LED_N_OFF_L(pwm->hwpwm);
248
249 regmap_write(pca->regmap, reg, 0x0);
250}
251
252static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
253{
254 struct pca9685 *pca = to_pca(chip);
255
256 if (pca->active_cnt++ == 0)
257 return regmap_update_bits(pca->regmap, PCA9685_MODE1,
258 MODE1_SLEEP, 0x0);
259
260 return 0;
261}
262
263static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
264{
265 struct pca9685 *pca = to_pca(chip);
266
267 if (--pca->active_cnt == 0)
268 regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP,
269 MODE1_SLEEP);
270}
271
272static const struct pwm_ops pca9685_pwm_ops = {
273 .enable = pca9685_pwm_enable,
274 .disable = pca9685_pwm_disable,
275 .config = pca9685_pwm_config,
276 .request = pca9685_pwm_request,
277 .free = pca9685_pwm_free,
278 .owner = THIS_MODULE,
279};
280
281static const struct regmap_config pca9685_regmap_i2c_config = {
282 .reg_bits = 8,
283 .val_bits = 8,
284 .max_register = PCA9685_NUMREGS,
285 .cache_type = REGCACHE_NONE,
286};
287
288static int pca9685_pwm_probe(struct i2c_client *client,
289 const struct i2c_device_id *id)
290{
291 struct pca9685 *pca;
292 int ret;
293 int mode2;
294
295 pca = devm_kzalloc(&client->dev, sizeof(*pca), GFP_KERNEL);
296 if (!pca)
297 return -ENOMEM;
298
299 pca->regmap = devm_regmap_init_i2c(client, &pca9685_regmap_i2c_config);
300 if (IS_ERR(pca->regmap)) {
301 ret = PTR_ERR(pca->regmap);
302 dev_err(&client->dev, "Failed to initialize register map: %d\n",
303 ret);
304 return ret;
305 }
306 pca->duty_ns = 0;
307 pca->period_ns = PCA9685_DEFAULT_PERIOD;
308
309 i2c_set_clientdata(client, pca);
310
311 regmap_read(pca->regmap, PCA9685_MODE2, &mode2);
312
313 if (device_property_read_bool(&client->dev, "invert"))
314 mode2 |= MODE2_INVRT;
315 else
316 mode2 &= ~MODE2_INVRT;
317
318 if (device_property_read_bool(&client->dev, "open-drain"))
319 mode2 &= ~MODE2_OUTDRV;
320 else
321 mode2 |= MODE2_OUTDRV;
322
323 regmap_write(pca->regmap, PCA9685_MODE2, mode2);
324
325 /* clear all "full off" bits */
326 regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0);
327 regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0);
328
329 pca->chip.ops = &pca9685_pwm_ops;
330 /* add an extra channel for ALL_LED */
331 pca->chip.npwm = PCA9685_MAXCHAN + 1;
332
333 pca->chip.dev = &client->dev;
334 pca->chip.base = -1;
335 pca->chip.can_sleep = true;
336
337 return pwmchip_add(&pca->chip);
338}
339
340static int pca9685_pwm_remove(struct i2c_client *client)
341{
342 struct pca9685 *pca = i2c_get_clientdata(client);
343
344 regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP,
345 MODE1_SLEEP);
346
347 return pwmchip_remove(&pca->chip);
348}
349
350static const struct i2c_device_id pca9685_id[] = {
351 { "pca9685", 0 },
352 { /* sentinel */ },
353};
354MODULE_DEVICE_TABLE(i2c, pca9685_id);
355
356#ifdef CONFIG_ACPI
357static const struct acpi_device_id pca9685_acpi_ids[] = {
358 { "INT3492", 0 },
359 { /* sentinel */ },
360};
361MODULE_DEVICE_TABLE(acpi, pca9685_acpi_ids);
362#endif
363
364#ifdef CONFIG_OF
365static const struct of_device_id pca9685_dt_ids[] = {
366 { .compatible = "nxp,pca9685-pwm", },
367 { /* sentinel */ }
368};
369MODULE_DEVICE_TABLE(of, pca9685_dt_ids);
370#endif
371
372static struct i2c_driver pca9685_i2c_driver = {
373 .driver = {
374 .name = "pca9685-pwm",
375 .acpi_match_table = ACPI_PTR(pca9685_acpi_ids),
376 .of_match_table = of_match_ptr(pca9685_dt_ids),
377 },
378 .probe = pca9685_pwm_probe,
379 .remove = pca9685_pwm_remove,
380 .id_table = pca9685_id,
381};
382
383module_i2c_driver(pca9685_i2c_driver);
384
385MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>");
386MODULE_DESCRIPTION("PWM driver for PCA9685");
387MODULE_LICENSE("GPL");