text: /*
   * File      : drv_iic.c
   * This file is part of RT-Thread RTOS
   * COPYRIGHT (C) 2017 RT-Thread Develop Team
   *
   * The license and distribution terms for this file may be
   * found in the file LICENSE in this distribution or at
   * http://www.rt-thread.org/license/LICENSE
   *
   * Change Logs:
   * Date           Author       Notes
   * 2017-06-05     tanek        first implementation.
   */
   
  #include "drv_i2c.h"
  
  #include <board.h>
  #include <finsh.h>
  #include <rtdevice.h>
  #include <rthw.h>
  
  #define DEBUG
  
  #ifdef DEBUG
  #define DEBUG_PRINTF(...)           rt_kprintf(__VA_ARGS__)
  #else
  #define DEBUG_PRINTF(...)   
  #endif
  
  #define I2C_SCL_PIN                 GPIO_PIN_6
  #define I2C_SCL_PORT                GPIOB
  #define I2C_SCL_PORT_CLK_ENABLE()   __HAL_RCC_GPIOB_CLK_ENABLE()
  #define I2C_SDA_PIN                 GPIO_PIN_9
  #define I2C_SDA_PORT                GPIOB
  #define I2C_SDL_PORT_CLK_ENABLE()   
  
  static struct rt_i2c_bus_device i2c_bus;
  
  
  static void stm32f4_i2c_gpio_init()
  {
  	GPIO_InitTypeDef GPIO_Initure;
  
  	I2C_SCL_PORT_CLK_ENABLE();
      I2C_SDL_PORT_CLK_ENABLE();
      
  	GPIO_Initure.Pin = I2C_SCL_PIN | I2C_SDA_PIN;
  	GPIO_Initure.Mode = GPIO_MODE_OUTPUT_OD;
  	GPIO_Initure.Pull = GPIO_NOPULL;
  	GPIO_Initure.Speed = GPIO_SPEED_HIGH;
  	HAL_GPIO_Init(I2C_SDA_PORT, &GPIO_Initure);
      
      HAL_GPIO_WritePin(I2C_SDA_PORT, I2C_SDA_PIN, GPIO_PIN_SET);
      HAL_GPIO_WritePin(I2C_SCL_PORT, I2C_SCL_PIN, GPIO_PIN_SET);
  }
  
  static void stm32f4_set_sda(void *data, rt_int32_t state)
  {
  	HAL_GPIO_WritePin(I2C_SDA_PORT, I2C_SDA_PIN, (GPIO_PinState)state);
  }
  
  static void stm32f4_set_scl(void *data, rt_int32_t state)
  {
  	HAL_GPIO_WritePin(I2C_SCL_PORT, I2C_SCL_PIN, (GPIO_PinState)state);
  }
  
  static rt_int32_t  stm32f4_get_sda(void *data)
  {
  	return (rt_int32_t)HAL_GPIO_ReadPin(I2C_SDA_PORT, I2C_SDA_PIN);
  }
  
  static rt_int32_t  stm32f4_get_scl(void *data)
  {
  	return (rt_int32_t)HAL_GPIO_ReadPin(I2C_SCL_PORT, I2C_SCL_PIN);
  }
  
  static void stm32f4_udelay(rt_uint32_t us)
  {
  	rt_int32_t i;
  	for (; us > 0; us--)
  	{
  		i = 50;
  		while (i > 0)
  		{
  			i--;
  		}
  	}
  }
  
  static const struct rt_i2c_bit_ops bit_ops = {
  	RT_NULL,
  	stm32f4_set_sda,
  	stm32f4_set_scl,
  	stm32f4_get_sda,
  	stm32f4_get_scl,
  
  	stm32f4_udelay,
  
  	50,
  	100
  };
  
  int stm32f4_i2c_init(void)
  {
  	i2c_bus.priv = (void *)&bit_ops;
  
  	stm32f4_i2c_gpio_init();
  
  	rt_i2c_bit_add_bus(&i2c_bus, "i2c0");
  
  	return RT_EOK;
  }
  INIT_DEVICE_EXPORT(stm32f4_i2c_init);
  