172 lines
4.0 KiB
C
172 lines
4.0 KiB
C
/*
|
|
* Copyright (c) 2015 Intel Corporation.
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
|
|
/**
|
|
* @file Driver for PCA9685 I2C-based PWM driver.
|
|
*/
|
|
|
|
#include <errno.h>
|
|
|
|
#include <kernel.h>
|
|
|
|
#include <i2c.h>
|
|
#include <pwm.h>
|
|
|
|
#include "pwm_pca9685.h"
|
|
|
|
#define REG_MODE1 0x00
|
|
#define REG_MODE2 0x01
|
|
|
|
#define REG_LED_ON_L(n) ((4 * n) + 0x06)
|
|
#define REG_LED_ON_H(n) ((4 * n) + 0x07)
|
|
#define REG_LED_OFF_L(n) ((4 * n) + 0x08)
|
|
#define REG_LED_OFF_H(n) ((4 * n) + 0x09)
|
|
|
|
#define REG_ALL_LED_ON_L 0xFA
|
|
#define REG_ALL_LED_ON_H 0xFB
|
|
#define REG_ALL_LED_OFF_L 0xFC
|
|
#define REG_ALL_LED_OFF_H 0xFD
|
|
#define REG_PRE_SCALE 0xFE
|
|
|
|
/* Maximum PWM outputs */
|
|
#define MAX_PWM_OUT 16
|
|
|
|
/* How many ticks per one period */
|
|
#define PWM_ONE_PERIOD_TICKS 4096
|
|
|
|
/**
|
|
* @brief Check to see if a I2C master is identified for communication.
|
|
*
|
|
* @param dev Device struct.
|
|
* @return 1 if I2C master is identified, 0 if not.
|
|
*/
|
|
static inline int _has_i2c_master(struct device *dev)
|
|
{
|
|
struct pwm_pca9685_drv_data * const drv_data =
|
|
(struct pwm_pca9685_drv_data * const)dev->driver_data;
|
|
struct device * const i2c_master = drv_data->i2c_master;
|
|
|
|
if (i2c_master)
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* period_count is always taken as 4095. To control the on period send
|
|
* value to pulse_count
|
|
*/
|
|
static int pwm_pca9685_pin_set_cycles(struct device *dev, u32_t pwm,
|
|
u32_t period_count, u32_t pulse_count)
|
|
{
|
|
const struct pwm_pca9685_config * const config =
|
|
dev->config->config_info;
|
|
struct pwm_pca9685_drv_data * const drv_data =
|
|
(struct pwm_pca9685_drv_data * const)dev->driver_data;
|
|
struct device * const i2c_master = drv_data->i2c_master;
|
|
u16_t i2c_addr = config->i2c_slave_addr;
|
|
u8_t buf[] = { 0, 0, 0, 0, 0};
|
|
|
|
ARG_UNUSED(period_count);
|
|
if (!_has_i2c_master(dev)) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (pwm > MAX_PWM_OUT) {
|
|
return -EINVAL;
|
|
}
|
|
buf[0] = REG_LED_ON_L(pwm);
|
|
|
|
/* If either pulse_count > max ticks, treat PWM as 100%.
|
|
* If pulse_count value == 0, treat it as 0%.
|
|
* Otherwise, populate registers accordingly.
|
|
*/
|
|
if (pulse_count >= PWM_ONE_PERIOD_TICKS) {
|
|
buf[1] = 0x0;
|
|
buf[2] = (1 << 4);
|
|
buf[3] = 0x0;
|
|
buf[4] = 0x0;
|
|
} else if (pulse_count == 0) {
|
|
buf[1] = 0x0;
|
|
buf[2] = 0x0;
|
|
buf[3] = 0x0;
|
|
buf[4] = (1 << 4);
|
|
} else {
|
|
/* No start delay given. When the count is 0 the
|
|
* pwm will be high .
|
|
*/
|
|
buf[0] = 0x0;
|
|
buf[1] = 0x0;
|
|
buf[2] = (pulse_count & 0xFF);
|
|
buf[3] = ((pulse_count >> 8) & 0x0F);
|
|
}
|
|
|
|
return i2c_write(i2c_master, buf, sizeof(buf), i2c_addr);
|
|
}
|
|
|
|
|
|
static const struct pwm_driver_api pwm_pca9685_drv_api_funcs = {
|
|
.pin_set = pwm_pca9685_pin_set_cycles
|
|
};
|
|
|
|
/**
|
|
* @brief Initialization function of PCA9685
|
|
*
|
|
* @param dev Device struct
|
|
* @return 0 if successful, failed otherwise.
|
|
*/
|
|
int pwm_pca9685_init(struct device *dev)
|
|
{
|
|
const struct pwm_pca9685_config * const config =
|
|
dev->config->config_info;
|
|
struct pwm_pca9685_drv_data * const drv_data =
|
|
(struct pwm_pca9685_drv_data * const)dev->driver_data;
|
|
struct device *i2c_master;
|
|
u8_t buf[] = {0, 0};
|
|
int ret;
|
|
|
|
/* Find out the device struct of the I2C master */
|
|
i2c_master = device_get_binding((char *)config->i2c_master_dev_name);
|
|
if (!i2c_master) {
|
|
return -EINVAL;
|
|
}
|
|
drv_data->i2c_master = i2c_master;
|
|
|
|
/* MODE1 register */
|
|
|
|
buf[0] = REG_MODE1;
|
|
buf[1] = (1 << 5); /* register addr auto increment */
|
|
|
|
ret = i2c_write(i2c_master, buf, 2, config->i2c_slave_addr);
|
|
if (ret != 0) {
|
|
return -EPERM;
|
|
}
|
|
|
|
dev->driver_api = &pwm_pca9685_drv_api_funcs;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Initialization for PWM_PCA9685_0 */
|
|
#ifdef CONFIG_PWM_PCA9685_0
|
|
#include <device.h>
|
|
#include <init.h>
|
|
|
|
static const struct pwm_pca9685_config pwm_pca9685_0_cfg = {
|
|
.i2c_master_dev_name = CONFIG_PWM_PCA9685_0_I2C_MASTER_DEV_NAME,
|
|
.i2c_slave_addr = CONFIG_PWM_PCA9685_0_I2C_ADDR,
|
|
};
|
|
|
|
static struct pwm_pca9685_drv_data pwm_pca9685_0_drvdata;
|
|
|
|
/* This has to init after I2C master */
|
|
DEVICE_INIT(pwm_pca9685_0, CONFIG_PWM_PCA9685_0_DEV_NAME,
|
|
pwm_pca9685_init,
|
|
&pwm_pca9685_0_drvdata, &pwm_pca9685_0_cfg,
|
|
POST_KERNEL, CONFIG_PWM_PCA9685_INIT_PRIORITY);
|
|
|
|
#endif /* CONFIG_PWM_PCA9685_0 */
|