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");