101 lines
2.0 KiB
C
101 lines
2.0 KiB
C
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/*
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* File : drv_iic.c
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* This file is part of RT-Thread RTOS
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* COPYRIGHT (C) 2017 RT-Thread Develop Team
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*
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* The license and distribution terms for this file may be
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* found in the file LICENSE in this distribution or at
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* http://www.rt-thread.org/license/LICENSE
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*
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* Change Logs:
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* Date Author Notes
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* 2017-06-09 tanek first implementation.
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*/
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#include "drv_pcf8574.h"
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#include <board.h>
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#include <rthw.h>
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#include <finsh.h>
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//#define DEBUG
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#ifdef DEBUG
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#define DEBUG_PRINTF(...) rt_kprintf(__VA_ARGS__)
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#else
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#define DEBUG_PRINTF(...)
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#endif
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#define I2C_BUS_NAME "i2c0"
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#define PCF8574_ADDR 0x20
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static uint8_t rt_pcf8574_read_onebyte(void);
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static void rt_pcf8574_write_onebyte(rt_uint8_t value);
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static struct rt_i2c_bus_device * i2c_bus;
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rt_err_t rt_pcf8574_init(void)
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{
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rt_uint8_t buffer[] = { 0xFF };
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rt_off_t pos = PCF8574_ADDR;
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__HAL_RCC_GPIOB_CLK_ENABLE();
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i2c_bus = (struct rt_i2c_bus_device *)rt_device_find(I2C_BUS_NAME);
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if (i2c_bus == RT_NULL)
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{
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DEBUG_PRINTF("\ni2c_bus %s for PCF8574 not found!\n", I2C_BUS_NAME);
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return -RT_ENOSYS;
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}
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if (rt_device_open(&i2c_bus->parent, RT_NULL) != RT_EOK)
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{
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DEBUG_PRINTF("\ni2c_bus %s for cs43l22 opened failed!\n", I2C_BUS_NAME);
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return -RT_EEMPTY;
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}
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rt_device_write(&i2c_bus->parent, pos, &buffer, 1);
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return RT_EOK;
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}
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static uint8_t rt_pcf8574_read_onebyte(void)
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{
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rt_uint8_t value;
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rt_device_read(&i2c_bus->parent, PCF8574_ADDR, &value, 1);
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return value;
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}
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static void rt_pcf8574_write_onebyte(rt_uint8_t value)
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{
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rt_device_write(&i2c_bus->parent, PCF8574_ADDR, &value, 1);
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}
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void rt_pcf8574_write_bit(rt_uint8_t bit, rt_uint8_t state)
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{
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rt_uint8_t data;
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data = rt_pcf8574_read_onebyte();
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if (state == 0)
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data &= ~(1 << bit);
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else
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data |= 1 << bit;
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rt_pcf8574_write_onebyte(data);
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}
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rt_uint8_t rt_pcf8574_read_bit(rt_uint8_t bit)
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{
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rt_uint8_t data;
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data = rt_pcf8574_read_onebyte();
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if (data&(1 << bit))
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return 1;
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else
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return 0;
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}
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