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/*
* Copyright (c) 2006-2018, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2017-06-09 tanek first implementation.
*/
#include "drv_pcf8574.h"
#include <board.h>
#include <rthw.h>
#include <finsh.h>
//#define DEBUG
#ifdef DEBUG
#define DEBUG_PRINTF(...) rt_kprintf(__VA_ARGS__)
#else
#define DEBUG_PRINTF(...)
#endif
#define I2C_BUS_NAME "i2c0"
#define PCF8574_ADDR 0x20
static uint8_t rt_pcf8574_read_onebyte(void);
static void rt_pcf8574_write_onebyte(rt_uint8_t value);
static struct rt_i2c_bus_device * i2c_bus;
rt_err_t rt_pcf8574_init(void)
{
rt_uint8_t buffer[] = { 0xFF };
rt_off_t pos = PCF8574_ADDR;
__HAL_RCC_GPIOB_CLK_ENABLE();
i2c_bus = (struct rt_i2c_bus_device *)rt_device_find(I2C_BUS_NAME);
if (i2c_bus == RT_NULL)
{
DEBUG_PRINTF("\ni2c_bus %s for PCF8574 not found!\n", I2C_BUS_NAME);
return -RT_ENOSYS;
}
if (rt_device_open(&i2c_bus->parent, RT_NULL) != RT_EOK)
{
DEBUG_PRINTF("\ni2c_bus %s for cs43l22 opened failed!\n", I2C_BUS_NAME);
return -RT_EEMPTY;
}
rt_device_write(&i2c_bus->parent, pos, &buffer, 1);
return RT_EOK;
}
static uint8_t rt_pcf8574_read_onebyte(void)
{
rt_uint8_t value;
rt_device_read(&i2c_bus->parent, PCF8574_ADDR, &value, 1);
return value;
}
static void rt_pcf8574_write_onebyte(rt_uint8_t value)
{
rt_device_write(&i2c_bus->parent, PCF8574_ADDR, &value, 1);
}
void rt_pcf8574_write_bit(rt_uint8_t bit, rt_uint8_t state)
{
rt_uint8_t data;
data = rt_pcf8574_read_onebyte();
if (state == 0)
data &= ~(1 << bit);
else
data |= 1 << bit;
rt_pcf8574_write_onebyte(data);
}
rt_uint8_t rt_pcf8574_read_bit(rt_uint8_t bit)
{
rt_uint8_t data;
data = rt_pcf8574_read_onebyte();
if (data&(1 << bit))
return 1;
else
return 0;
}
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