rt-thread/bsp/stm32f10x/drivers/i2c.c

86 lines
2.1 KiB
C

#include "i2c.h"
#include <stm32f10x.h>
void stm32_set_sda(void *data, rt_int32_t state)
{
if(state == 1)
GPIO_SetBits(I2C1_GPIO , I2C1_GPIO_SDA); //GPIOB->BSRRL = I2C1_GPIO_SDA
else if(state == 0)
GPIO_ResetBits(I2C1_GPIO , I2C1_GPIO_SDA); //GPIOB->BSRRH = I2C1_GPIO_SDA
}
void stm32_set_scl(void *data, rt_int32_t state)
{
if(state == 1)
GPIO_SetBits(I2C1_GPIO , I2C1_GPIO_SCL); //GPIOB->BSRRL = I2C1_GPIO_SCL
else if(state == 0)
GPIO_ResetBits(I2C1_GPIO , I2C1_GPIO_SCL); //GPIOB->BSRRH = I2C1_GPIO_SCL
}
rt_int32_t stm32_get_sda(void *data)
{
return (rt_int32_t)GPIO_ReadInputDataBit(I2C1_GPIO , I2C1_GPIO_SDA); //return(GPIOB->IDR & I2C1_GPIO_SDA)
}
rt_int32_t stm32_get_scl(void *data)
{
return (rt_int32_t)GPIO_ReadInputDataBit(I2C1_GPIO , I2C1_GPIO_SCL); //return(GPIOB->IDR & I2C1_GPIO_SCL)
}
void stm32_udelay(rt_uint32_t us)
{
rt_uint32_t delta;
/* sysTick->LOAD=21000, RT_TICK_PER_SECOND=1000 */
us = us * (SysTick->LOAD/(1000000/RT_TICK_PER_SECOND));
delta = SysTick->VAL;
/* delay us */
while (delta - SysTick->VAL< us);
}
void stm32_mdelay(rt_uint32_t ms)
{
stm32_udelay(ms * 1000);
}
static const struct rt_i2c_bit_ops stm32_i2c_bit_ops =
{
(void*)0xaa, //no use in set_sda,set_scl,get_sda,get_scl
stm32_set_sda,
stm32_set_scl,
stm32_get_sda,
stm32_get_scl,
stm32_udelay,
20,
};
static void RCC_Configuration(void)
{
RCC->APB2ENR|=1<<4;
RCC_APB2PeriphClockCmd( RCC_I2C, ENABLE );
}
static void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Pin = I2C1_GPIO_SDA | I2C1_GPIO_SCL;
GPIO_InitStructure.GPIO_Mode =GPIO_Mode_Out_OD ;
GPIO_InitStructure.GPIO_Speed =GPIO_Speed_50MHz;
GPIO_Init(I2C1_GPIO, &GPIO_InitStructure);
}
int rt_hw_i2c_init(void)
{
static struct rt_i2c_bus_device stm32_i2c;
RCC_Configuration();
GPIO_Configuration();
rt_memset((void *)&stm32_i2c, 0, sizeof(struct rt_i2c_bus_device));
stm32_i2c.priv = (void *)&stm32_i2c_bit_ops;
rt_i2c_bit_add_bus(&stm32_i2c, "i2c1");
return 0;
}
INIT_BOARD_EXPORT(rt_hw_i2c_init);