1 // SPDX-License-Identifier: GPL-2.0-only
3 * Driver for PCA9685 16-channel 12-bit PWM LED controller
5 * Copyright (C) 2013 Steffen Trumtrar <s.trumtrar@pengutronix.de>
6 * Copyright (C) 2015 Clemens Gruber <clemens.gruber@pqgruber.com>
8 * based on the pwm-twl-led.c driver
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>
25 * Because the PCA9685 has only one prescaler per chip, changing the period of
26 * one channel affects the period of all 16 PWM outputs!
27 * However, the ratio between each configured duty cycle and the chip-wide
28 * period remains constant, because the OFF time is set in proportion to the
32 #define PCA9685_MODE1 0x00
33 #define PCA9685_MODE2 0x01
34 #define PCA9685_SUBADDR1 0x02
35 #define PCA9685_SUBADDR2 0x03
36 #define PCA9685_SUBADDR3 0x04
37 #define PCA9685_ALLCALLADDR 0x05
38 #define PCA9685_LEDX_ON_L 0x06
39 #define PCA9685_LEDX_ON_H 0x07
40 #define PCA9685_LEDX_OFF_L 0x08
41 #define PCA9685_LEDX_OFF_H 0x09
43 #define PCA9685_ALL_LED_ON_L 0xFA
44 #define PCA9685_ALL_LED_ON_H 0xFB
45 #define PCA9685_ALL_LED_OFF_L 0xFC
46 #define PCA9685_ALL_LED_OFF_H 0xFD
47 #define PCA9685_PRESCALE 0xFE
49 #define PCA9685_PRESCALE_MIN 0x03 /* => max. frequency of 1526 Hz */
50 #define PCA9685_PRESCALE_MAX 0xFF /* => min. frequency of 24 Hz */
52 #define PCA9685_COUNTER_RANGE 4096
53 #define PCA9685_DEFAULT_PERIOD 5000000 /* Default period_ns = 1/200 Hz */
54 #define PCA9685_OSC_CLOCK_MHZ 25 /* Internal oscillator with 25 MHz */
56 #define PCA9685_NUMREGS 0xFF
57 #define PCA9685_MAXCHAN 0x10
59 #define LED_FULL (1 << 4)
60 #define MODE1_SLEEP (1 << 4)
61 #define MODE2_INVRT (1 << 4)
62 #define MODE2_OUTDRV (1 << 2)
64 #define LED_N_ON_H(N) (PCA9685_LEDX_ON_H + (4 * (N)))
65 #define LED_N_ON_L(N) (PCA9685_LEDX_ON_L + (4 * (N)))
66 #define LED_N_OFF_H(N) (PCA9685_LEDX_OFF_H + (4 * (N)))
67 #define LED_N_OFF_L(N) (PCA9685_LEDX_OFF_L + (4 * (N)))
71 struct regmap *regmap;
74 #if IS_ENABLED(CONFIG_GPIOLIB)
76 struct gpio_chip gpio;
80 static inline struct pca9685 *to_pca(struct pwm_chip *chip)
82 return container_of(chip, struct pca9685, chip);
85 #if IS_ENABLED(CONFIG_GPIOLIB)
86 static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset)
88 struct pca9685 *pca = gpiochip_get_data(gpio);
89 struct pwm_device *pwm;
91 mutex_lock(&pca->lock);
93 pwm = &pca->chip.pwms[offset];
95 if (pwm->flags & (PWMF_REQUESTED | PWMF_EXPORTED)) {
96 mutex_unlock(&pca->lock);
100 pwm_set_chip_data(pwm, (void *)1);
102 mutex_unlock(&pca->lock);
103 pm_runtime_get_sync(pca->chip.dev);
107 static bool pca9685_pwm_is_gpio(struct pca9685 *pca, struct pwm_device *pwm)
109 bool is_gpio = false;
111 mutex_lock(&pca->lock);
113 if (pwm->hwpwm >= PCA9685_MAXCHAN) {
117 * Check if any of the GPIOs are requested and in that case
118 * prevent using the "all LEDs" channel.
120 for (i = 0; i < pca->gpio.ngpio; i++)
121 if (gpiochip_is_requested(&pca->gpio, i)) {
125 } else if (pwm_get_chip_data(pwm)) {
129 mutex_unlock(&pca->lock);
133 static int pca9685_pwm_gpio_get(struct gpio_chip *gpio, unsigned int offset)
135 struct pca9685 *pca = gpiochip_get_data(gpio);
136 struct pwm_device *pwm = &pca->chip.pwms[offset];
139 regmap_read(pca->regmap, LED_N_ON_H(pwm->hwpwm), &value);
141 return value & LED_FULL;
144 static void pca9685_pwm_gpio_set(struct gpio_chip *gpio, unsigned int offset,
147 struct pca9685 *pca = gpiochip_get_data(gpio);
148 struct pwm_device *pwm = &pca->chip.pwms[offset];
149 unsigned int on = value ? LED_FULL : 0;
151 /* Clear both OFF registers */
152 regmap_write(pca->regmap, LED_N_OFF_L(pwm->hwpwm), 0);
153 regmap_write(pca->regmap, LED_N_OFF_H(pwm->hwpwm), 0);
155 /* Set the full ON bit */
156 regmap_write(pca->regmap, LED_N_ON_H(pwm->hwpwm), on);
159 static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset)
161 struct pca9685 *pca = gpiochip_get_data(gpio);
163 pca9685_pwm_gpio_set(gpio, offset, 0);
164 pm_runtime_put(pca->chip.dev);
167 static int pca9685_pwm_gpio_get_direction(struct gpio_chip *chip,
174 static int pca9685_pwm_gpio_direction_input(struct gpio_chip *gpio,
180 static int pca9685_pwm_gpio_direction_output(struct gpio_chip *gpio,
181 unsigned int offset, int value)
183 pca9685_pwm_gpio_set(gpio, offset, value);
189 * The PCA9685 has a bit for turning the PWM output full off or on. Some
190 * boards like Intel Galileo actually uses these as normal GPIOs so we
191 * expose a GPIO chip here which can exclusively take over the underlying
194 static int pca9685_pwm_gpio_probe(struct pca9685 *pca)
196 struct device *dev = pca->chip.dev;
198 mutex_init(&pca->lock);
200 pca->gpio.label = dev_name(dev);
201 pca->gpio.parent = dev;
202 pca->gpio.request = pca9685_pwm_gpio_request;
203 pca->gpio.free = pca9685_pwm_gpio_free;
204 pca->gpio.get_direction = pca9685_pwm_gpio_get_direction;
205 pca->gpio.direction_input = pca9685_pwm_gpio_direction_input;
206 pca->gpio.direction_output = pca9685_pwm_gpio_direction_output;
207 pca->gpio.get = pca9685_pwm_gpio_get;
208 pca->gpio.set = pca9685_pwm_gpio_set;
210 pca->gpio.ngpio = PCA9685_MAXCHAN;
211 pca->gpio.can_sleep = true;
213 return devm_gpiochip_add_data(dev, &pca->gpio, pca);
216 static inline bool pca9685_pwm_is_gpio(struct pca9685 *pca,
217 struct pwm_device *pwm)
222 static inline int pca9685_pwm_gpio_probe(struct pca9685 *pca)
228 static void pca9685_set_sleep_mode(struct pca9685 *pca, bool enable)
230 regmap_update_bits(pca->regmap, PCA9685_MODE1,
231 MODE1_SLEEP, enable ? MODE1_SLEEP : 0);
233 /* Wait 500us for the oscillator to be back up */
238 static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
239 int duty_ns, int period_ns)
241 struct pca9685 *pca = to_pca(chip);
242 unsigned long long duty;
246 if (period_ns != pca->period_ns) {
247 prescale = DIV_ROUND_CLOSEST(PCA9685_OSC_CLOCK_MHZ * period_ns,
248 PCA9685_COUNTER_RANGE * 1000) - 1;
250 if (prescale >= PCA9685_PRESCALE_MIN &&
251 prescale <= PCA9685_PRESCALE_MAX) {
253 * putting the chip briefly into SLEEP mode
254 * at this point won't interfere with the
255 * pm_runtime framework, because the pm_runtime
256 * state is guaranteed active here.
258 /* Put chip into sleep mode */
259 pca9685_set_sleep_mode(pca, true);
261 /* Change the chip-wide output frequency */
262 regmap_write(pca->regmap, PCA9685_PRESCALE, prescale);
264 /* Wake the chip up */
265 pca9685_set_sleep_mode(pca, false);
267 pca->period_ns = period_ns;
270 "prescaler not set: period out of bounds!\n");
275 pca->duty_ns = duty_ns;
278 if (pwm->hwpwm >= PCA9685_MAXCHAN)
279 reg = PCA9685_ALL_LED_OFF_H;
281 reg = LED_N_OFF_H(pwm->hwpwm);
283 regmap_write(pca->regmap, reg, LED_FULL);
288 if (duty_ns == period_ns) {
289 /* Clear both OFF registers */
290 if (pwm->hwpwm >= PCA9685_MAXCHAN)
291 reg = PCA9685_ALL_LED_OFF_L;
293 reg = LED_N_OFF_L(pwm->hwpwm);
295 regmap_write(pca->regmap, reg, 0x0);
297 if (pwm->hwpwm >= PCA9685_MAXCHAN)
298 reg = PCA9685_ALL_LED_OFF_H;
300 reg = LED_N_OFF_H(pwm->hwpwm);
302 regmap_write(pca->regmap, reg, 0x0);
304 /* Set the full ON bit */
305 if (pwm->hwpwm >= PCA9685_MAXCHAN)
306 reg = PCA9685_ALL_LED_ON_H;
308 reg = LED_N_ON_H(pwm->hwpwm);
310 regmap_write(pca->regmap, reg, LED_FULL);
315 duty = PCA9685_COUNTER_RANGE * (unsigned long long)duty_ns;
316 duty = DIV_ROUND_UP_ULL(duty, period_ns);
318 if (pwm->hwpwm >= PCA9685_MAXCHAN)
319 reg = PCA9685_ALL_LED_OFF_L;
321 reg = LED_N_OFF_L(pwm->hwpwm);
323 regmap_write(pca->regmap, reg, (int)duty & 0xff);
325 if (pwm->hwpwm >= PCA9685_MAXCHAN)
326 reg = PCA9685_ALL_LED_OFF_H;
328 reg = LED_N_OFF_H(pwm->hwpwm);
330 regmap_write(pca->regmap, reg, ((int)duty >> 8) & 0xf);
332 /* Clear the full ON bit, otherwise the set OFF time has no effect */
333 if (pwm->hwpwm >= PCA9685_MAXCHAN)
334 reg = PCA9685_ALL_LED_ON_H;
336 reg = LED_N_ON_H(pwm->hwpwm);
338 regmap_write(pca->regmap, reg, 0);
343 static int pca9685_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
345 struct pca9685 *pca = to_pca(chip);
349 * The PWM subsystem does not support a pre-delay.
350 * So, set the ON-timeout to 0
352 if (pwm->hwpwm >= PCA9685_MAXCHAN)
353 reg = PCA9685_ALL_LED_ON_L;
355 reg = LED_N_ON_L(pwm->hwpwm);
357 regmap_write(pca->regmap, reg, 0);
359 if (pwm->hwpwm >= PCA9685_MAXCHAN)
360 reg = PCA9685_ALL_LED_ON_H;
362 reg = LED_N_ON_H(pwm->hwpwm);
364 regmap_write(pca->regmap, reg, 0);
367 * Clear the full-off bit.
368 * It has precedence over the others and must be off.
370 if (pwm->hwpwm >= PCA9685_MAXCHAN)
371 reg = PCA9685_ALL_LED_OFF_H;
373 reg = LED_N_OFF_H(pwm->hwpwm);
375 regmap_update_bits(pca->regmap, reg, LED_FULL, 0x0);
380 static void pca9685_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
382 struct pca9685 *pca = to_pca(chip);
385 if (pwm->hwpwm >= PCA9685_MAXCHAN)
386 reg = PCA9685_ALL_LED_OFF_H;
388 reg = LED_N_OFF_H(pwm->hwpwm);
390 regmap_write(pca->regmap, reg, LED_FULL);
392 /* Clear the LED_OFF counter. */
393 if (pwm->hwpwm >= PCA9685_MAXCHAN)
394 reg = PCA9685_ALL_LED_OFF_L;
396 reg = LED_N_OFF_L(pwm->hwpwm);
398 regmap_write(pca->regmap, reg, 0x0);
401 static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
403 struct pca9685 *pca = to_pca(chip);
405 if (pca9685_pwm_is_gpio(pca, pwm))
407 pm_runtime_get_sync(chip->dev);
412 static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
414 pca9685_pwm_disable(chip, pwm);
415 pm_runtime_put(chip->dev);
418 static const struct pwm_ops pca9685_pwm_ops = {
419 .enable = pca9685_pwm_enable,
420 .disable = pca9685_pwm_disable,
421 .config = pca9685_pwm_config,
422 .request = pca9685_pwm_request,
423 .free = pca9685_pwm_free,
424 .owner = THIS_MODULE,
427 static const struct regmap_config pca9685_regmap_i2c_config = {
430 .max_register = PCA9685_NUMREGS,
431 .cache_type = REGCACHE_NONE,
434 static int pca9685_pwm_probe(struct i2c_client *client,
435 const struct i2c_device_id *id)
441 pca = devm_kzalloc(&client->dev, sizeof(*pca), GFP_KERNEL);
445 pca->regmap = devm_regmap_init_i2c(client, &pca9685_regmap_i2c_config);
446 if (IS_ERR(pca->regmap)) {
447 ret = PTR_ERR(pca->regmap);
448 dev_err(&client->dev, "Failed to initialize register map: %d\n",
453 pca->period_ns = PCA9685_DEFAULT_PERIOD;
455 i2c_set_clientdata(client, pca);
457 regmap_read(pca->regmap, PCA9685_MODE2, &mode2);
459 if (device_property_read_bool(&client->dev, "invert"))
460 mode2 |= MODE2_INVRT;
462 mode2 &= ~MODE2_INVRT;
464 if (device_property_read_bool(&client->dev, "open-drain"))
465 mode2 &= ~MODE2_OUTDRV;
467 mode2 |= MODE2_OUTDRV;
469 regmap_write(pca->regmap, PCA9685_MODE2, mode2);
471 /* clear all "full off" bits */
472 regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0);
473 regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0);
475 pca->chip.ops = &pca9685_pwm_ops;
476 /* add an extra channel for ALL_LED */
477 pca->chip.npwm = PCA9685_MAXCHAN + 1;
479 pca->chip.dev = &client->dev;
482 ret = pwmchip_add(&pca->chip);
486 ret = pca9685_pwm_gpio_probe(pca);
488 pwmchip_remove(&pca->chip);
492 /* the chip comes out of power-up in the active state */
493 pm_runtime_set_active(&client->dev);
495 * enable will put the chip into suspend, which is what we
496 * want as all outputs are disabled at this point
498 pm_runtime_enable(&client->dev);
503 static int pca9685_pwm_remove(struct i2c_client *client)
505 struct pca9685 *pca = i2c_get_clientdata(client);
508 ret = pwmchip_remove(&pca->chip);
511 pm_runtime_disable(&client->dev);
516 static int pca9685_pwm_runtime_suspend(struct device *dev)
518 struct i2c_client *client = to_i2c_client(dev);
519 struct pca9685 *pca = i2c_get_clientdata(client);
521 pca9685_set_sleep_mode(pca, true);
525 static int pca9685_pwm_runtime_resume(struct device *dev)
527 struct i2c_client *client = to_i2c_client(dev);
528 struct pca9685 *pca = i2c_get_clientdata(client);
530 pca9685_set_sleep_mode(pca, false);
535 static const struct i2c_device_id pca9685_id[] = {
539 MODULE_DEVICE_TABLE(i2c, pca9685_id);
542 static const struct acpi_device_id pca9685_acpi_ids[] = {
546 MODULE_DEVICE_TABLE(acpi, pca9685_acpi_ids);
550 static const struct of_device_id pca9685_dt_ids[] = {
551 { .compatible = "nxp,pca9685-pwm", },
554 MODULE_DEVICE_TABLE(of, pca9685_dt_ids);
557 static const struct dev_pm_ops pca9685_pwm_pm = {
558 SET_RUNTIME_PM_OPS(pca9685_pwm_runtime_suspend,
559 pca9685_pwm_runtime_resume, NULL)
562 static struct i2c_driver pca9685_i2c_driver = {
564 .name = "pca9685-pwm",
565 .acpi_match_table = ACPI_PTR(pca9685_acpi_ids),
566 .of_match_table = of_match_ptr(pca9685_dt_ids),
567 .pm = &pca9685_pwm_pm,
569 .probe = pca9685_pwm_probe,
570 .remove = pca9685_pwm_remove,
571 .id_table = pca9685_id,
574 module_i2c_driver(pca9685_i2c_driver);
576 MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>");
577 MODULE_DESCRIPTION("PWM driver for PCA9685");
578 MODULE_LICENSE("GPL");