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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");