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>
35 * Because the PCA9685 has only one prescaler per chip, changing the period of
36 * one channel affects the period of all 16 PWM outputs!
37 * However, the ratio between each configured duty cycle and the chip-wide
38 * period remains constant, because the OFF time is set in proportion to the
42 #define PCA9685_MODE1 0x00
43 #define PCA9685_MODE2 0x01
44 #define PCA9685_SUBADDR1 0x02
45 #define PCA9685_SUBADDR2 0x03
46 #define PCA9685_SUBADDR3 0x04
47 #define PCA9685_ALLCALLADDR 0x05
48 #define PCA9685_LEDX_ON_L 0x06
49 #define PCA9685_LEDX_ON_H 0x07
50 #define PCA9685_LEDX_OFF_L 0x08
51 #define PCA9685_LEDX_OFF_H 0x09
53 #define PCA9685_ALL_LED_ON_L 0xFA
54 #define PCA9685_ALL_LED_ON_H 0xFB
55 #define PCA9685_ALL_LED_OFF_L 0xFC
56 #define PCA9685_ALL_LED_OFF_H 0xFD
57 #define PCA9685_PRESCALE 0xFE
59 #define PCA9685_PRESCALE_MIN 0x03 /* => max. frequency of 1526 Hz */
60 #define PCA9685_PRESCALE_MAX 0xFF /* => min. frequency of 24 Hz */
62 #define PCA9685_COUNTER_RANGE 4096
63 #define PCA9685_DEFAULT_PERIOD 5000000 /* Default period_ns = 1/200 Hz */
64 #define PCA9685_OSC_CLOCK_MHZ 25 /* Internal oscillator with 25 MHz */
66 #define PCA9685_NUMREGS 0xFF
67 #define PCA9685_MAXCHAN 0x10
69 #define LED_FULL (1 << 4)
70 #define MODE1_SLEEP (1 << 4)
71 #define MODE2_INVRT (1 << 4)
72 #define MODE2_OUTDRV (1 << 2)
74 #define LED_N_ON_H(N) (PCA9685_LEDX_ON_H + (4 * (N)))
75 #define LED_N_ON_L(N) (PCA9685_LEDX_ON_L + (4 * (N)))
76 #define LED_N_OFF_H(N) (PCA9685_LEDX_OFF_H + (4 * (N)))
77 #define LED_N_OFF_L(N) (PCA9685_LEDX_OFF_L + (4 * (N)))
81 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
);
117 static void pca9685_pwm_gpio_free(struct gpio_chip
*gpio
, unsigned int offset
)
119 struct pca9685
*pca
= gpiochip_get_data(gpio
);
120 struct pwm_device
*pwm
;
122 mutex_lock(&pca
->lock
);
123 pwm
= &pca
->chip
.pwms
[offset
];
124 pwm_set_chip_data(pwm
, NULL
);
125 mutex_unlock(&pca
->lock
);
128 static bool pca9685_pwm_is_gpio(struct pca9685
*pca
, struct pwm_device
*pwm
)
130 bool is_gpio
= false;
132 mutex_lock(&pca
->lock
);
134 if (pwm
->hwpwm
>= PCA9685_MAXCHAN
) {
138 * Check if any of the GPIOs are requested and in that case
139 * prevent using the "all LEDs" channel.
141 for (i
= 0; i
< pca
->gpio
.ngpio
; i
++)
142 if (gpiochip_is_requested(&pca
->gpio
, i
)) {
146 } else if (pwm_get_chip_data(pwm
)) {
150 mutex_unlock(&pca
->lock
);
154 static int pca9685_pwm_gpio_get(struct gpio_chip
*gpio
, unsigned int offset
)
156 struct pca9685
*pca
= gpiochip_get_data(gpio
);
157 struct pwm_device
*pwm
= &pca
->chip
.pwms
[offset
];
160 regmap_read(pca
->regmap
, LED_N_ON_H(pwm
->hwpwm
), &value
);
162 return value
& LED_FULL
;
165 static void pca9685_pwm_gpio_set(struct gpio_chip
*gpio
, unsigned int offset
,
168 struct pca9685
*pca
= gpiochip_get_data(gpio
);
169 struct pwm_device
*pwm
= &pca
->chip
.pwms
[offset
];
170 unsigned int on
= value
? LED_FULL
: 0;
172 /* Clear both OFF registers */
173 regmap_write(pca
->regmap
, LED_N_OFF_L(pwm
->hwpwm
), 0);
174 regmap_write(pca
->regmap
, LED_N_OFF_H(pwm
->hwpwm
), 0);
176 /* Set the full ON bit */
177 regmap_write(pca
->regmap
, LED_N_ON_H(pwm
->hwpwm
), on
);
180 static int pca9685_pwm_gpio_get_direction(struct gpio_chip
*chip
,
187 static int pca9685_pwm_gpio_direction_input(struct gpio_chip
*gpio
,
193 static int pca9685_pwm_gpio_direction_output(struct gpio_chip
*gpio
,
194 unsigned int offset
, int value
)
196 pca9685_pwm_gpio_set(gpio
, offset
, value
);
202 * The PCA9685 has a bit for turning the PWM output full off or on. Some
203 * boards like Intel Galileo actually uses these as normal GPIOs so we
204 * expose a GPIO chip here which can exclusively take over the underlying
207 static int pca9685_pwm_gpio_probe(struct pca9685
*pca
)
209 struct device
*dev
= pca
->chip
.dev
;
211 mutex_init(&pca
->lock
);
213 pca
->gpio
.label
= dev_name(dev
);
214 pca
->gpio
.parent
= dev
;
215 pca
->gpio
.request
= pca9685_pwm_gpio_request
;
216 pca
->gpio
.free
= pca9685_pwm_gpio_free
;
217 pca
->gpio
.get_direction
= pca9685_pwm_gpio_get_direction
;
218 pca
->gpio
.direction_input
= pca9685_pwm_gpio_direction_input
;
219 pca
->gpio
.direction_output
= pca9685_pwm_gpio_direction_output
;
220 pca
->gpio
.get
= pca9685_pwm_gpio_get
;
221 pca
->gpio
.set
= pca9685_pwm_gpio_set
;
223 pca
->gpio
.ngpio
= PCA9685_MAXCHAN
;
224 pca
->gpio
.can_sleep
= true;
226 return devm_gpiochip_add_data(dev
, &pca
->gpio
, pca
);
229 static inline bool pca9685_pwm_is_gpio(struct pca9685
*pca
,
230 struct pwm_device
*pwm
)
235 static inline int pca9685_pwm_gpio_probe(struct pca9685
*pca
)
241 static int pca9685_pwm_config(struct pwm_chip
*chip
, struct pwm_device
*pwm
,
242 int duty_ns
, int period_ns
)
244 struct pca9685
*pca
= to_pca(chip
);
245 unsigned long long duty
;
249 if (period_ns
!= pca
->period_ns
) {
250 prescale
= DIV_ROUND_CLOSEST(PCA9685_OSC_CLOCK_MHZ
* period_ns
,
251 PCA9685_COUNTER_RANGE
* 1000) - 1;
253 if (prescale
>= PCA9685_PRESCALE_MIN
&&
254 prescale
<= PCA9685_PRESCALE_MAX
) {
255 /* Put chip into sleep mode */
256 regmap_update_bits(pca
->regmap
, PCA9685_MODE1
,
257 MODE1_SLEEP
, MODE1_SLEEP
);
259 /* Change the chip-wide output frequency */
260 regmap_write(pca
->regmap
, PCA9685_PRESCALE
, prescale
);
262 /* Wake the chip up */
263 regmap_update_bits(pca
->regmap
, PCA9685_MODE1
,
266 /* Wait 500us for the oscillator to be back up */
269 pca
->period_ns
= period_ns
;
272 "prescaler not set: period out of bounds!\n");
277 pca
->duty_ns
= duty_ns
;
280 if (pwm
->hwpwm
>= PCA9685_MAXCHAN
)
281 reg
= PCA9685_ALL_LED_OFF_H
;
283 reg
= LED_N_OFF_H(pwm
->hwpwm
);
285 regmap_write(pca
->regmap
, reg
, LED_FULL
);
290 if (duty_ns
== period_ns
) {
291 /* Clear both OFF registers */
292 if (pwm
->hwpwm
>= PCA9685_MAXCHAN
)
293 reg
= PCA9685_ALL_LED_OFF_L
;
295 reg
= LED_N_OFF_L(pwm
->hwpwm
);
297 regmap_write(pca
->regmap
, reg
, 0x0);
299 if (pwm
->hwpwm
>= PCA9685_MAXCHAN
)
300 reg
= PCA9685_ALL_LED_OFF_H
;
302 reg
= LED_N_OFF_H(pwm
->hwpwm
);
304 regmap_write(pca
->regmap
, reg
, 0x0);
306 /* Set the full ON bit */
307 if (pwm
->hwpwm
>= PCA9685_MAXCHAN
)
308 reg
= PCA9685_ALL_LED_ON_H
;
310 reg
= LED_N_ON_H(pwm
->hwpwm
);
312 regmap_write(pca
->regmap
, reg
, LED_FULL
);
317 duty
= PCA9685_COUNTER_RANGE
* (unsigned long long)duty_ns
;
318 duty
= DIV_ROUND_UP_ULL(duty
, period_ns
);
320 if (pwm
->hwpwm
>= PCA9685_MAXCHAN
)
321 reg
= PCA9685_ALL_LED_OFF_L
;
323 reg
= LED_N_OFF_L(pwm
->hwpwm
);
325 regmap_write(pca
->regmap
, reg
, (int)duty
& 0xff);
327 if (pwm
->hwpwm
>= PCA9685_MAXCHAN
)
328 reg
= PCA9685_ALL_LED_OFF_H
;
330 reg
= LED_N_OFF_H(pwm
->hwpwm
);
332 regmap_write(pca
->regmap
, reg
, ((int)duty
>> 8) & 0xf);
334 /* Clear the full ON bit, otherwise the set OFF time has no effect */
335 if (pwm
->hwpwm
>= PCA9685_MAXCHAN
)
336 reg
= PCA9685_ALL_LED_ON_H
;
338 reg
= LED_N_ON_H(pwm
->hwpwm
);
340 regmap_write(pca
->regmap
, reg
, 0);
345 static int pca9685_pwm_enable(struct pwm_chip
*chip
, struct pwm_device
*pwm
)
347 struct pca9685
*pca
= to_pca(chip
);
351 * The PWM subsystem does not support a pre-delay.
352 * So, set the ON-timeout to 0
354 if (pwm
->hwpwm
>= PCA9685_MAXCHAN
)
355 reg
= PCA9685_ALL_LED_ON_L
;
357 reg
= LED_N_ON_L(pwm
->hwpwm
);
359 regmap_write(pca
->regmap
, reg
, 0);
361 if (pwm
->hwpwm
>= PCA9685_MAXCHAN
)
362 reg
= PCA9685_ALL_LED_ON_H
;
364 reg
= LED_N_ON_H(pwm
->hwpwm
);
366 regmap_write(pca
->regmap
, reg
, 0);
369 * Clear the full-off bit.
370 * It has precedence over the others and must be off.
372 if (pwm
->hwpwm
>= PCA9685_MAXCHAN
)
373 reg
= PCA9685_ALL_LED_OFF_H
;
375 reg
= LED_N_OFF_H(pwm
->hwpwm
);
377 regmap_update_bits(pca
->regmap
, reg
, LED_FULL
, 0x0);
382 static void pca9685_pwm_disable(struct pwm_chip
*chip
, struct pwm_device
*pwm
)
384 struct pca9685
*pca
= to_pca(chip
);
387 if (pwm
->hwpwm
>= PCA9685_MAXCHAN
)
388 reg
= PCA9685_ALL_LED_OFF_H
;
390 reg
= LED_N_OFF_H(pwm
->hwpwm
);
392 regmap_write(pca
->regmap
, reg
, LED_FULL
);
394 /* Clear the LED_OFF counter. */
395 if (pwm
->hwpwm
>= PCA9685_MAXCHAN
)
396 reg
= PCA9685_ALL_LED_OFF_L
;
398 reg
= LED_N_OFF_L(pwm
->hwpwm
);
400 regmap_write(pca
->regmap
, reg
, 0x0);
403 static int pca9685_pwm_request(struct pwm_chip
*chip
, struct pwm_device
*pwm
)
405 struct pca9685
*pca
= to_pca(chip
);
407 if (pca9685_pwm_is_gpio(pca
, pwm
))
410 if (pca
->active_cnt
++ == 0)
411 return regmap_update_bits(pca
->regmap
, PCA9685_MODE1
,
417 static void pca9685_pwm_free(struct pwm_chip
*chip
, struct pwm_device
*pwm
)
419 struct pca9685
*pca
= to_pca(chip
);
421 if (--pca
->active_cnt
== 0)
422 regmap_update_bits(pca
->regmap
, PCA9685_MODE1
, MODE1_SLEEP
,
426 static const struct pwm_ops pca9685_pwm_ops
= {
427 .enable
= pca9685_pwm_enable
,
428 .disable
= pca9685_pwm_disable
,
429 .config
= pca9685_pwm_config
,
430 .request
= pca9685_pwm_request
,
431 .free
= pca9685_pwm_free
,
432 .owner
= THIS_MODULE
,
435 static const struct regmap_config pca9685_regmap_i2c_config
= {
438 .max_register
= PCA9685_NUMREGS
,
439 .cache_type
= REGCACHE_NONE
,
442 static int pca9685_pwm_probe(struct i2c_client
*client
,
443 const struct i2c_device_id
*id
)
449 pca
= devm_kzalloc(&client
->dev
, sizeof(*pca
), GFP_KERNEL
);
453 pca
->regmap
= devm_regmap_init_i2c(client
, &pca9685_regmap_i2c_config
);
454 if (IS_ERR(pca
->regmap
)) {
455 ret
= PTR_ERR(pca
->regmap
);
456 dev_err(&client
->dev
, "Failed to initialize register map: %d\n",
461 pca
->period_ns
= PCA9685_DEFAULT_PERIOD
;
463 i2c_set_clientdata(client
, pca
);
465 regmap_read(pca
->regmap
, PCA9685_MODE2
, &mode2
);
467 if (device_property_read_bool(&client
->dev
, "invert"))
468 mode2
|= MODE2_INVRT
;
470 mode2
&= ~MODE2_INVRT
;
472 if (device_property_read_bool(&client
->dev
, "open-drain"))
473 mode2
&= ~MODE2_OUTDRV
;
475 mode2
|= MODE2_OUTDRV
;
477 regmap_write(pca
->regmap
, PCA9685_MODE2
, mode2
);
479 /* clear all "full off" bits */
480 regmap_write(pca
->regmap
, PCA9685_ALL_LED_OFF_L
, 0);
481 regmap_write(pca
->regmap
, PCA9685_ALL_LED_OFF_H
, 0);
483 pca
->chip
.ops
= &pca9685_pwm_ops
;
484 /* add an extra channel for ALL_LED */
485 pca
->chip
.npwm
= PCA9685_MAXCHAN
+ 1;
487 pca
->chip
.dev
= &client
->dev
;
490 ret
= pwmchip_add(&pca
->chip
);
494 ret
= pca9685_pwm_gpio_probe(pca
);
496 pwmchip_remove(&pca
->chip
);
501 static int pca9685_pwm_remove(struct i2c_client
*client
)
503 struct pca9685
*pca
= i2c_get_clientdata(client
);
505 regmap_update_bits(pca
->regmap
, PCA9685_MODE1
, MODE1_SLEEP
,
508 return pwmchip_remove(&pca
->chip
);
511 static const struct i2c_device_id pca9685_id
[] = {
515 MODULE_DEVICE_TABLE(i2c
, pca9685_id
);
518 static const struct acpi_device_id pca9685_acpi_ids
[] = {
522 MODULE_DEVICE_TABLE(acpi
, pca9685_acpi_ids
);
526 static const struct of_device_id pca9685_dt_ids
[] = {
527 { .compatible
= "nxp,pca9685-pwm", },
530 MODULE_DEVICE_TABLE(of
, pca9685_dt_ids
);
533 static struct i2c_driver pca9685_i2c_driver
= {
535 .name
= "pca9685-pwm",
536 .acpi_match_table
= ACPI_PTR(pca9685_acpi_ids
),
537 .of_match_table
= of_match_ptr(pca9685_dt_ids
),
539 .probe
= pca9685_pwm_probe
,
540 .remove
= pca9685_pwm_remove
,
541 .id_table
= pca9685_id
,
544 module_i2c_driver(pca9685_i2c_driver
);
546 MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>");
547 MODULE_DESCRIPTION("PWM driver for PCA9685");
548 MODULE_LICENSE("GPL");