linux-imx

/*

 * Driver for PCA9685 16-channel 12-bit PWM LED controller

 *

 * Copyright (C) 2013 Steffen Trumtrar <s.trumtrar@pengutronix.de>

 * Copyright (C) 2015 Clemens Gruber <clemens.gruber@pqgruber.com>

 *

 * based on the pwm-twl-led.c driver

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 as published by

 * the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

 * more details.

 *

 * You should have received a copy of the GNU General Public License along with

 * this program.  If not, see <http://www.gnu.org/licenses/>.

 */

​

#include <linux/acpi.h>

#include <linux/gpio/driver.h>

#include <linux/i2c.h>

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/platform_device.h>

#include <linux/property.h>

#include <linux/pwm.h>

#include <linux/regmap.h>

#include <linux/slab.h>

#include <linux/delay.h>

#include <linux/pm_runtime.h>

​

/*

 * Because the PCA9685 has only one prescaler per chip, changing the period of

 * one channel affects the period of all 16 PWM outputs!

 * However, the ratio between each configured duty cycle and the chip-wide

 * period remains constant, because the OFF time is set in proportion to the

 * counter range.

 */

​

#define PCA9685_MODE1       0x00

#define PCA9685_MODE2       0x01

#define PCA9685_SUBADDR1    0x02

#define PCA9685_SUBADDR2    0x03

#define PCA9685_SUBADDR3    0x04

#define PCA9685_ALLCALLADDR 0x05

#define PCA9685_LEDX_ON_L   0x06

#define PCA9685_LEDX_ON_H   0x07

#define PCA9685_LEDX_OFF_L  0x08

#define PCA9685_LEDX_OFF_H  0x09

​

#define PCA9685_ALL_LED_ON_L    0xFA

#define PCA9685_ALL_LED_ON_H    0xFB

#define PCA9685_ALL_LED_OFF_L   0xFC

#define PCA9685_ALL_LED_OFF_H   0xFD

#define PCA9685_PRESCALE    0xFE

​

#define PCA9685_PRESCALE_MIN    0x03    /* => max. frequency of 1526 Hz */

#define PCA9685_PRESCALE_MAX    0xFF    /* => min. frequency of 24 Hz */

​

#define PCA9685_COUNTER_RANGE   4096