/******************** (C) COPYRIGHT 2008 STMicroelectronics ********************
* File Name          : stm32f10x_i2c.c
* Author             : MCD Application Team
* Version            : V2.0.2
* Date               : 07/11/2008
* Description        : This file provides all the I2C firmware functions.
********************************************************************************
* THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME.
* AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT,
* INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE
* CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING
* INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
*******************************************************************************/

/* Includes ------------------------------------------------------------------*/
#include "stm32f10x_i2c.h"
#include "stm32f10x_rcc.h"
	 
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* I2C SPE mask */
#define CR1_PE_Set              ((u16)0x0001)
#define CR1_PE_Reset            ((u16)0xFFFE)

/* I2C START mask */
#define CR1_START_Set           ((u16)0x0100)
#define CR1_START_Reset         ((u16)0xFEFF)

/* I2C STOP mask */
#define CR1_STOP_Set            ((u16)0x0200)
#define CR1_STOP_Reset          ((u16)0xFDFF)

/* I2C ACK mask */
#define CR1_ACK_Set             ((u16)0x0400)
#define CR1_ACK_Reset           ((u16)0xFBFF)

/* I2C ENGC mask */
#define CR1_ENGC_Set            ((u16)0x0040)
#define CR1_ENGC_Reset          ((u16)0xFFBF)

/* I2C SWRST mask */
#define CR1_SWRST_Set           ((u16)0x8000)
#define CR1_SWRST_Reset         ((u16)0x7FFF)

/* I2C PEC mask */
#define CR1_PEC_Set             ((u16)0x1000)
#define CR1_PEC_Reset           ((u16)0xEFFF)

/* I2C ENPEC mask */
#define CR1_ENPEC_Set           ((u16)0x0020)
#define CR1_ENPEC_Reset         ((u16)0xFFDF)

/* I2C ENARP mask */
#define CR1_ENARP_Set           ((u16)0x0010)
#define CR1_ENARP_Reset         ((u16)0xFFEF)

/* I2C NOSTRETCH mask */
#define CR1_NOSTRETCH_Set       ((u16)0x0080)
#define CR1_NOSTRETCH_Reset     ((u16)0xFF7F)

/* I2C registers Masks */
#define CR1_CLEAR_Mask          ((u16)0xFBF5)

/* I2C DMAEN mask */
#define CR2_DMAEN_Set           ((u16)0x0800)
#define CR2_DMAEN_Reset         ((u16)0xF7FF)

/* I2C LAST mask */
#define CR2_LAST_Set            ((u16)0x1000)
#define CR2_LAST_Reset          ((u16)0xEFFF)

/* I2C FREQ mask */
#define CR2_FREQ_Reset          ((u16)0xFFC0)

/* I2C ADD0 mask */
#define OAR1_ADD0_Set           ((u16)0x0001)
#define OAR1_ADD0_Reset         ((u16)0xFFFE)

/* I2C ENDUAL mask */
#define OAR2_ENDUAL_Set         ((u16)0x0001)
#define OAR2_ENDUAL_Reset       ((u16)0xFFFE)

/* I2C ADD2 mask */
#define OAR2_ADD2_Reset         ((u16)0xFF01)

/* I2C F/S mask */
#define CCR_FS_Set              ((u16)0x8000)

/* I2C CCR mask */
#define CCR_CCR_Set             ((u16)0x0FFF)

/* I2C FLAG mask */
#define FLAG_Mask               ((u32)0x00FFFFFF)

/* I2C Interrupt Enable mask */
#define ITEN_Mask               ((u32)0x07000000)

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/

/*******************************************************************************
* Function Name  : I2C_DeInit
* Description    : Deinitializes the I2Cx peripheral registers to their default
*                  reset values.
* Input          : - I2Cx: where x can be 1 or 2 to select the I2C peripheral.
* Output         : None
* Return         : None
*******************************************************************************/
void I2C_DeInit(I2C_TypeDef* I2Cx)
{
  /* Check the parameters */
  assert_param(IS_I2C_ALL_PERIPH(I2Cx));

  switch (*(u32*)&I2Cx)
  {
    case I2C1_BASE:
      /* Enable I2C1 reset state */
      RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C1, ENABLE);
      /* Release I2C1 from reset state */
      RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C1, DISABLE);
      break;

    case I2C2_BASE:
      /* Enable I2C2 reset state */
      RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C2, ENABLE);
      /* Release I2C2 from reset state */
      RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C2, DISABLE);
      break;

    default:
      break;
  }
}

/*******************************************************************************
* Function Name  : I2C_Init
* Description    : Initializes the I2Cx peripheral according to the specified 
*                  parameters in the I2C_InitStruct.
* Input          : - I2Cx: where x can be 1 or 2 to select the I2C peripheral.
*                  - I2C_InitStruct: pointer to a I2C_InitTypeDef structure that
*                    contains the configuration information for the specified
*                    I2C peripheral.
* Output         : None
* Return         : None
******************************************************************************/
void I2C_Init(I2C_TypeDef* I2Cx, I2C_InitTypeDef* I2C_InitStruct)
{
  u16 tmpreg = 0, freqrange = 0;
  u16 result = 0x04;
  u32 pclk1 = 8000000;
  RCC_ClocksTypeDef  rcc_clocks;

  /* Check the parameters */
  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
  assert_param(IS_I2C_MODE(I2C_InitStruct->I2C_Mode));
  assert_param(IS_I2C_DUTY_CYCLE(I2C_InitStruct->I2C_DutyCycle));
  assert_param(IS_I2C_OWN_ADDRESS1(I2C_InitStruct->I2C_OwnAddress1));
  assert_param(IS_I2C_ACK_STATE(I2C_InitStruct->I2C_Ack));
  assert_param(IS_I2C_ACKNOWLEDGE_ADDRESS(I2C_InitStruct->I2C_AcknowledgedAddress));
  assert_param(IS_I2C_CLOCK_SPEED(I2C_InitStruct->I2C_ClockSpeed));

/*---------------------------- I2Cx CR2 Configuration ------------------------*/
  /* Get the I2Cx CR2 value */
  tmpreg = I2Cx->CR2;
  /* Clear frequency FREQ[5:0] bits */
  tmpreg &= CR2_FREQ_Reset;
  /* Get pclk1 frequency value */
  RCC_GetClocksFreq(&rcc_clocks);
  pclk1 = rcc_clocks.PCLK1_Frequency;
  /* Set frequency bits depending on pclk1 value */
  freqrange = (u16)(pclk1 / 1000000);
  tmpreg |= freqrange;
  /* Write to I2Cx CR2 */
  I2Cx->CR2 = tmpreg;

/*---------------------------- I2Cx CCR Configuration ------------------------*/
  /* Disable the selected I2C peripheral to configure TRISE */
  I2Cx->CR1 &= CR1_PE_Reset;

  /* Reset tmpreg value */
  /* Clear F/S, DUTY and CCR[11:0] bits */
  tmpreg = 0;

  /* Configure speed in standard mode */
  if (I2C_InitStruct->I2C_ClockSpeed <= 100000)
  {
    /* Standard mode speed calculate */
    result = (u16)(pclk1 / (I2C_InitStruct->I2C_ClockSpeed << 1));
    /* Test if CCR value is under 0x4*/
    if (result < 0x04)
    {
      /* Set minimum allowed value */
      result = 0x04;  
    }
    /* Set speed value for standard mode */
    tmpreg |= result;	  
    /* Set Maximum Rise Time for standard mode */
    I2Cx->TRISE = freqrange + 1; 
  }
  /* Configure speed in fast mode */
  else /*(I2C_InitStruct->I2C_ClockSpeed <= 400000)*/
  {
    if (I2C_InitStruct->I2C_DutyCycle == I2C_DutyCycle_2)
    {
      /* Fast mode speed calculate: Tlow/Thigh = 2 */
      result = (u16)(pclk1 / (I2C_InitStruct->I2C_ClockSpeed * 3));
    }
    else /*I2C_InitStruct->I2C_DutyCycle == I2C_DutyCycle_16_9*/
    {
      /* Fast mode speed calculate: Tlow/Thigh = 16/9 */
      result = (u16)(pclk1 / (I2C_InitStruct->I2C_ClockSpeed * 25));
      /* Set DUTY bit */
      result |= I2C_DutyCycle_16_9;
    }
    /* Test if CCR value is under 0x1*/
    if ((result & CCR_CCR_Set) == 0)
    {
      /* Set minimum allowed value */
      result |= (u16)0x0001;  
    }
    /* Set speed value and set F/S bit for fast mode */
    tmpreg |= result | CCR_FS_Set;
    /* Set Maximum Rise Time for fast mode */
    I2Cx->TRISE = (u16)(((freqrange * 300) / 1000) + 1);  
  }
  /* Write to I2Cx CCR */
  I2Cx->CCR = tmpreg;

  /* Enable the selected I2C peripheral */
  I2Cx->CR1 |= CR1_PE_Set;

/*---------------------------- I2Cx CR1 Configuration ------------------------*/
  /* Get the I2Cx CR1 value */
  tmpreg = I2Cx->CR1;
  /* Clear ACK, SMBTYPE and  SMBUS bits */
  tmpreg &= CR1_CLEAR_Mask;
  /* Configure I2Cx: mode and acknowledgement */
  /* Set SMBTYPE and SMBUS bits according to I2C_Mode value */
  /* Set ACK bit according to I2C_Ack value */
  tmpreg |= (u16)((u32)I2C_InitStruct->I2C_Mode | I2C_InitStruct->I2C_Ack);
  /* Write to I2Cx CR1 */
  I2Cx->CR1 = tmpreg;

/*---------------------------- I2Cx OAR1 Configuration -----------------------*/
  /* Set I2Cx Own Address1 and acknowledged address */
  I2Cx->OAR1 = (I2C_InitStruct->I2C_AcknowledgedAddress | I2C_InitStruct->I2C_OwnAddress1);
}

/*******************************************************************************
* Function Name  : I2C_StructInit
* Description    : Fills each I2C_InitStruct member with its default value.
* Input          : - I2C_InitStruct: pointer to an I2C_InitTypeDef structure
*                    which will be initialized.
* Output         : None
* Return         : None
*******************************************************************************/
void I2C_StructInit(I2C_InitTypeDef* I2C_InitStruct)
{
/*---------------- Reset I2C init structure parameters values ----------------*/
  /* Initialize the I2C_Mode member */
  I2C_InitStruct->I2C_Mode = I2C_Mode_I2C;

  /* Initialize the I2C_DutyCycle member */
  I2C_InitStruct->I2C_DutyCycle = I2C_DutyCycle_2;

  /* Initialize the I2C_OwnAddress1 member */
  I2C_InitStruct->I2C_OwnAddress1 = 0;

  /* Initialize the I2C_Ack member */
  I2C_InitStruct->I2C_Ack = I2C_Ack_Disable;

  /* Initialize the I2C_AcknowledgedAddress member */
  I2C_InitStruct->I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;

  /* initialize the I2C_ClockSpeed member */
  I2C_InitStruct->I2C_ClockSpeed = 5000;
}

/*******************************************************************************
* Function Name  : I2C_Cmd
* Description    : Enables or disables the specified I2C peripheral.
* Input          : - I2Cx: where x can be 1 or 2 to select the I2C peripheral.
*                  - NewState: new state of the I2Cx peripheral. This parameter
*                    can be: ENABLE or DISABLE.
* Output         : None
* Return         : None
*******************************************************************************/
void I2C_Cmd(I2C_TypeDef* I2Cx, FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)
  {
    /* Enable the selected I2C peripheral */
    I2Cx->CR1 |= CR1_PE_Set;
  }
  else
  {
    /* Disable the selected I2C peripheral */
    I2Cx->CR1 &= CR1_PE_Reset;
  }
}

/*******************************************************************************
* Function Name  : I2C_DMACmd
* Description    : Enables or disables the specified I2C DMA requests.
* Input          : - I2Cx: where x can be 1 or 2 to select the I2C peripheral.
*                  - NewState: new state of the I2C DMA transfer.
*                    This parameter can be: ENABLE or DISABLE.
* Output         : None
* Return         : None
*******************************************************************************/
void I2C_DMACmd(I2C_TypeDef* I2Cx, FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)
  {
    /* Enable the selected I2C DMA requests */
    I2Cx->CR2 |= CR2_DMAEN_Set;
  }
  else
  {
    /* Disable the selected I2C DMA requests */
    I2Cx->CR2 &= CR2_DMAEN_Reset;
  }
}