2 * Driver for PCA9685 16-channel 12-bit PWM LED controller
4 * Copyright (C) 2013 Steffen Trumtrar <s.trumtrar@pengutronix.de>
5 * Copyright (C) 2015 Clemens Gruber <clemens.gruber@pqgruber.com>
7 * based on the pwm-twl-led.c driver
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.
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
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/>.
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>
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
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
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
60 #define PCA9685_PRESCALE_MIN 0x03 /* => max. frequency of 1526 Hz */
61 #define PCA9685_PRESCALE_MAX 0xFF /* => min. frequency of 24 Hz */
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 */
67 #define PCA9685_NUMREGS 0xFF
68 #define PCA9685_MAXCHAN 0x10
70 #define LED_FULL (1 << 4)
71 #define MODE1_SLEEP (1 << 4)
72 #define MODE2_INVRT (1 << 4)
73 #define MODE2_OUTDRV (1 << 2)
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)))
82 struct regmap *regmap;
85 #if IS_ENABLED(CONFIG_GPIOLIB)
87 struct gpio_chip gpio;
91 static inline struct pca9685 *to_pca(struct pwm_chip *chip)
93 return container_of(chip, struct pca9685, chip);
96 #if IS_ENABLED(CONFIG_GPIOLIB)
97 static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset)
99 struct pca9685 *pca = gpiochip_get_data(gpio);
100 struct pwm_device *pwm;
102 mutex_lock(&pca->lock);
104 pwm = &pca->chip.pwms[offset];
106 if (pwm->flags & (PWMF_REQUESTED | PWMF_EXPORTED)) {
107 mutex_unlock(&pca->lock);
111 pwm_set_chip_data(pwm, (void *)1);
113 mutex_unlock(&pca->lock);
114 pm_runtime_get_sync(pca->chip.dev);
118 static bool pca9685_pwm_is_gpio(struct pca9685 *pca, struct pwm_device *pwm)
120 bool is_gpio = false;
122 mutex_lock(&pca->lock);
124 if (pwm->hwpwm >= PCA9685_MAXCHAN) {
128 * Check if any of the GPIOs are requested and in that case
129 * prevent using the "all LEDs" channel.
131 for (i = 0; i < pca->gpio.ngpio; i++)
132 if (gpiochip_is_requested(&pca->gpio, i)) {
136 } else if (pwm_get_chip_data(pwm)) {
140 mutex_unlock(&pca->lock);
144 static int pca9685_pwm_gpio_get(struct gpio_chip *gpio, unsigned int offset)
146 struct pca9685 *pca = gpiochip_get_data(gpio);
147 struct pwm_device *pwm = &pca->chip.pwms[offset];
150 regmap_read(pca->regmap, LED_N_ON_H(pwm->hwpwm), &value);
152 return value & LED_FULL;
155 static void pca9685_pwm_gpio_set(struct gpio_chip *gpio, unsigned int offset,
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;
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);
166 /* Set the full ON bit */
167 regmap_write(pca->regmap, LED_N_ON_H(pwm->hwpwm), on);
170 static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset)
172 struct pca9685 *pca = gpiochip_get_data(gpio);
173 struct pwm_device *pwm;
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 mutex_unlock(&pca->lock);
182 static int pca9685_pwm_gpio_get_direction(struct gpio_chip *chip,
189 static int pca9685_pwm_gpio_direction_input(struct gpio_chip *gpio,
195 static int pca9685_pwm_gpio_direction_output(struct gpio_chip *gpio,
196 unsigned int offset, int value)
198 pca9685_pwm_gpio_set(gpio, offset, value);
204 * The PCA9685 has a bit for turning the PWM output full off or on. Some
205 * boards like Intel Galileo actually uses these as normal GPIOs so we
206 * expose a GPIO chip here which can exclusively take over the underlying
209 static int pca9685_pwm_gpio_probe(struct pca9685 *pca)
211 struct device *dev = pca->chip.dev;
213 mutex_init(&pca->lock);
215 pca->gpio.label = dev_name(dev);
216 pca->gpio.parent = dev;
217 pca->gpio.request = pca9685_pwm_gpio_request;
218 pca->gpio.free = pca9685_pwm_gpio_free;
219 pca->gpio.get_direction = pca9685_pwm_gpio_get_direction;
220 pca->gpio.direction_input = pca9685_pwm_gpio_direction_input;
221 pca->gpio.direction_output = pca9685_pwm_gpio_direction_output;
222 pca->gpio.get = pca9685_pwm_gpio_get;
223 pca->gpio.set = pca9685_pwm_gpio_set;
225 pca->gpio.ngpio = PCA9685_MAXCHAN;
226 pca->gpio.can_sleep = true;
228 return devm_gpiochip_add_data(dev, &pca->gpio, pca);
231 static inline bool pca9685_pwm_is_gpio(struct pca9685 *pca,
232 struct pwm_device *pwm)
237 static inline int pca9685_pwm_gpio_probe(struct pca9685 *pca)
243 static void pca9685_set_sleep_mode(struct pca9685 *pca, bool enable)
245 regmap_update_bits(pca->regmap, PCA9685_MODE1,
246 MODE1_SLEEP, enable ? MODE1_SLEEP : 0);
248 /* Wait 500us for the oscillator to be back up */
253 static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
254 int duty_ns, int period_ns)
256 struct pca9685 *pca = to_pca(chip);
257 unsigned long long duty;
261 if (period_ns != pca->period_ns) {
262 prescale = DIV_ROUND_CLOSEST(PCA9685_OSC_CLOCK_MHZ * period_ns,
263 PCA9685_COUNTER_RANGE * 1000) - 1;
265 if (prescale >= PCA9685_PRESCALE_MIN &&
266 prescale <= PCA9685_PRESCALE_MAX) {
268 * putting the chip briefly into SLEEP mode
269 * at this point won't interfere with the
270 * pm_runtime framework, because the pm_runtime
271 * state is guaranteed active here.
273 /* Put chip into sleep mode */
274 pca9685_set_sleep_mode(pca, true);
276 /* Change the chip-wide output frequency */
277 regmap_write(pca->regmap, PCA9685_PRESCALE, prescale);
279 /* Wake the chip up */
280 pca9685_set_sleep_mode(pca, false);
282 pca->period_ns = period_ns;
285 "prescaler not set: period out of bounds!\n");
290 pca->duty_ns = duty_ns;
293 if (pwm->hwpwm >= PCA9685_MAXCHAN)
294 reg = PCA9685_ALL_LED_OFF_H;
296 reg = LED_N_OFF_H(pwm->hwpwm);
298 regmap_write(pca->regmap, reg, LED_FULL);
303 if (duty_ns == period_ns) {
304 /* Clear both OFF registers */
305 if (pwm->hwpwm >= PCA9685_MAXCHAN)
306 reg = PCA9685_ALL_LED_OFF_L;
308 reg = LED_N_OFF_L(pwm->hwpwm);
310 regmap_write(pca->regmap, reg, 0x0);
312 if (pwm->hwpwm >= PCA9685_MAXCHAN)
313 reg = PCA9685_ALL_LED_OFF_H;
315 reg = LED_N_OFF_H(pwm->hwpwm);
317 regmap_write(pca->regmap, reg, 0x0);
319 /* Set the full ON bit */
320 if (pwm->hwpwm >= PCA9685_MAXCHAN)
321 reg = PCA9685_ALL_LED_ON_H;
323 reg = LED_N_ON_H(pwm->hwpwm);
325 regmap_write(pca->regmap, reg, LED_FULL);
330 duty = PCA9685_COUNTER_RANGE * (unsigned long long)duty_ns;
331 duty = DIV_ROUND_UP_ULL(duty, period_ns);
333 if (pwm->hwpwm >= PCA9685_MAXCHAN)
334 reg = PCA9685_ALL_LED_OFF_L;
336 reg = LED_N_OFF_L(pwm->hwpwm);
338 regmap_write(pca->regmap, reg, (int)duty & 0xff);
340 if (pwm->hwpwm >= PCA9685_MAXCHAN)
341 reg = PCA9685_ALL_LED_OFF_H;
343 reg = LED_N_OFF_H(pwm->hwpwm);
345 regmap_write(pca->regmap, reg, ((int)duty >> 8) & 0xf);
347 /* Clear the full ON bit, otherwise the set OFF time has no effect */
348 if (pwm->hwpwm >= PCA9685_MAXCHAN)
349 reg = PCA9685_ALL_LED_ON_H;
351 reg = LED_N_ON_H(pwm->hwpwm);
353 regmap_write(pca->regmap, reg, 0);
358 static int pca9685_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
360 struct pca9685 *pca = to_pca(chip);
364 * The PWM subsystem does not support a pre-delay.
365 * So, set the ON-timeout to 0
367 if (pwm->hwpwm >= PCA9685_MAXCHAN)
368 reg = PCA9685_ALL_LED_ON_L;
370 reg = LED_N_ON_L(pwm->hwpwm);
372 regmap_write(pca->regmap, reg, 0);
374 if (pwm->hwpwm >= PCA9685_MAXCHAN)
375 reg = PCA9685_ALL_LED_ON_H;
377 reg = LED_N_ON_H(pwm->hwpwm);
379 regmap_write(pca->regmap, reg, 0);
382 * Clear the full-off bit.
383 * It has precedence over the others and must be off.
385 if (pwm->hwpwm >= PCA9685_MAXCHAN)
386 reg = PCA9685_ALL_LED_OFF_H;
388 reg = LED_N_OFF_H(pwm->hwpwm);
390 regmap_update_bits(pca->regmap, reg, LED_FULL, 0x0);
395 static void pca9685_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
397 struct pca9685 *pca = to_pca(chip);
400 if (pwm->hwpwm >= PCA9685_MAXCHAN)
401 reg = PCA9685_ALL_LED_OFF_H;
403 reg = LED_N_OFF_H(pwm->hwpwm);
405 regmap_write(pca->regmap, reg, LED_FULL);
407 /* Clear the LED_OFF counter. */
408 if (pwm->hwpwm >= PCA9685_MAXCHAN)
409 reg = PCA9685_ALL_LED_OFF_L;
411 reg = LED_N_OFF_L(pwm->hwpwm);
413 regmap_write(pca->regmap, reg, 0x0);
416 static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
418 struct pca9685 *pca = to_pca(chip);
420 if (pca9685_pwm_is_gpio(pca, pwm))
422 pm_runtime_get_sync(chip->dev);
427 static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
429 pca9685_pwm_disable(chip, pwm);
430 pm_runtime_put(chip->dev);
433 static const struct pwm_ops pca9685_pwm_ops = {
434 .enable = pca9685_pwm_enable,
435 .disable = pca9685_pwm_disable,
436 .config = pca9685_pwm_config,
437 .request = pca9685_pwm_request,
438 .free = pca9685_pwm_free,
439 .owner = THIS_MODULE,
442 static const struct regmap_config pca9685_regmap_i2c_config = {
445 .max_register = PCA9685_NUMREGS,
446 .cache_type = REGCACHE_NONE,
449 static int pca9685_pwm_probe(struct i2c_client *client,
450 const struct i2c_device_id *id)
456 pca = devm_kzalloc(&client->dev, sizeof(*pca), GFP_KERNEL);
460 pca->regmap = devm_regmap_init_i2c(client, &pca9685_regmap_i2c_config);
461 if (IS_ERR(pca->regmap)) {
462 ret = PTR_ERR(pca->regmap);
463 dev_err(&client->dev, "Failed to initialize register map: %d\n",
468 pca->period_ns = PCA9685_DEFAULT_PERIOD;
470 i2c_set_clientdata(client, pca);
472 regmap_read(pca->regmap, PCA9685_MODE2, &mode2);
474 if (device_property_read_bool(&client->dev, "invert"))
475 mode2 |= MODE2_INVRT;
477 mode2 &= ~MODE2_INVRT;
479 if (device_property_read_bool(&client->dev, "open-drain"))
480 mode2 &= ~MODE2_OUTDRV;
482 mode2 |= MODE2_OUTDRV;
484 regmap_write(pca->regmap, PCA9685_MODE2, mode2);
486 /* clear all "full off" bits */
487 regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0);
488 regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0);
490 pca->chip.ops = &pca9685_pwm_ops;
491 /* add an extra channel for ALL_LED */
492 pca->chip.npwm = PCA9685_MAXCHAN + 1;
494 pca->chip.dev = &client->dev;
497 ret = pwmchip_add(&pca->chip);
501 ret = pca9685_pwm_gpio_probe(pca);
503 pwmchip_remove(&pca->chip);
507 /* the chip comes out of power-up in the active state */
508 pm_runtime_set_active(&client->dev);
510 * enable will put the chip into suspend, which is what we
511 * want as all outputs are disabled at this point
513 pm_runtime_enable(&client->dev);
518 static int pca9685_pwm_remove(struct i2c_client *client)
520 struct pca9685 *pca = i2c_get_clientdata(client);
523 ret = pwmchip_remove(&pca->chip);
526 pm_runtime_disable(&client->dev);
531 static int pca9685_pwm_runtime_suspend(struct device *dev)
533 struct i2c_client *client = to_i2c_client(dev);
534 struct pca9685 *pca = i2c_get_clientdata(client);
536 pca9685_set_sleep_mode(pca, true);
540 static int pca9685_pwm_runtime_resume(struct device *dev)
542 struct i2c_client *client = to_i2c_client(dev);
543 struct pca9685 *pca = i2c_get_clientdata(client);
545 pca9685_set_sleep_mode(pca, false);
550 static const struct i2c_device_id pca9685_id[] = {
554 MODULE_DEVICE_TABLE(i2c, pca9685_id);
557 static const struct acpi_device_id pca9685_acpi_ids[] = {
561 MODULE_DEVICE_TABLE(acpi, pca9685_acpi_ids);
565 static const struct of_device_id pca9685_dt_ids[] = {
566 { .compatible = "nxp,pca9685-pwm", },
569 MODULE_DEVICE_TABLE(of, pca9685_dt_ids);
572 static const struct dev_pm_ops pca9685_pwm_pm = {
573 SET_RUNTIME_PM_OPS(pca9685_pwm_runtime_suspend,
574 pca9685_pwm_runtime_resume, NULL)
577 static struct i2c_driver pca9685_i2c_driver = {
579 .name = "pca9685-pwm",
580 .acpi_match_table = ACPI_PTR(pca9685_acpi_ids),
581 .of_match_table = of_match_ptr(pca9685_dt_ids),
582 .pm = &pca9685_pwm_pm,
584 .probe = pca9685_pwm_probe,
585 .remove = pca9685_pwm_remove,
586 .id_table = pca9685_id,
589 module_i2c_driver(pca9685_i2c_driver);
591 MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>");
592 MODULE_DESCRIPTION("PWM driver for PCA9685");
593 MODULE_LICENSE("GPL");