i2c.c

Mouse for USB demo, based on STR710

  /******************** (C) COPYRIGHT 2003 STMicroelectronics ********************
* File Name          : i2c.c
* Author             : MCD Application Team
* Date First Issued  : 05/09/2003
* Description        : This file provides Code sources I2C functions
********************************************************************************
* History:
*  05/09/03 : Created.
*******************************************************************************/

#include "i2c.h"
#include "rccu.h"

/*******************************************************************************
* Function Name  : I2C_Init
* Description    : Initializes I2C peripheral control and registers to their
*                  default reset values.
* Input          : I2Cx ( I2C0 or I2C1 )
* Return         : None.
*******************************************************************************/
void I2C_Init (I2C_TypeDef *I2Cx)
{
  //Initialize all the register of the specified I2C passed as parameter
  I2Cx->CR=0x0;
  I2Cx->CCR=0x0;
  I2Cx->ECCR=0x0;
  I2Cx->OAR1=0x0;
  I2Cx->OAR2=0x20;
  (void)I2Cx->SR1;
  (void)I2Cx->SR2;
  I2Cx->DR=0x0;
}

/*******************************************************************************
* Function Name  : I2C_OnOffConfig
* Description    : Enables or disables I2C peripheral.
* Input          : I2Cx ( I2C0 or I2C1 )
*                  condition(ENABLE or DISABLE).
* Return         : None.
*******************************************************************************/
void I2C_OnOffConfig (I2C_TypeDef *I2Cx, FunctionalState NewState)
{
  if (NewState == ENABLE)
    {
      // Enable the I2C selected by setting twice the PE bit on the CR register
      I2Cx->CR |= I2C_PESET_Mask;
      I2Cx->CR |= I2C_PESET_Mask;
    }
  else
      // Disable the I2C selected
      I2Cx->CR &= ~I2C_PESET_Mask;
}

/*******************************************************************************
* Function Name  : I2C_FlagStatus
* Description    : Checks whether any I2C Flag is set or not.
* Input          : I2Cx ( I2C0 or I2C1 )
*                  Access(DIRECT or INDIRECT)
*                  Flag : the flag to be read
*                  input 4: an (u8) variable needed in the case
*                                     of the INDIRECT access
* Return         : the NewState of the Flag (SET or RESET).
*******************************************************************************/
FlagStatus I2C_FlagStatus (I2C_TypeDef *I2Cx, RegisterAccess Access, I2C_Flags Flag, ...)
{
  u16 Tmp;

  if (Access == DIRECT)
    // Store in Tmp variable the register where is located the flag
    Tmp = I2C_GetStatus(I2Cx)&Flag;
  else
    //Get the fourth register
    Tmp = ((u16)*((u32 *)&Flag + sizeof(Flag)))&Flag;
  //Return the Flag NewState
  return Tmp != 0 ? SET : RESET;
}

/*******************************************************************************
* Function Name  :  I2C_FlagClear
* Description    : Clears the I2C Flag passed as a parameter
* Input          : I2Cx ( I2C0 or I2C1 )
*                  Flag : the flag to be read
*                  input3: an (u8) parameter needed in the case that the flag
*                         to be cleared need a write in one register
* Return         : None.
*******************************************************************************/
void I2C_FlagClear (I2C_TypeDef *I2Cx, I2C_Flags Flag, ...)
{
  u8 Tmp = (u8)*((u32 *)&Flag + sizeof(Flag));

  if (Flag==I2C_ADD10 || Flag==I2C_EVF || Flag==I2C_BERR || Flag==I2C_ARLO ||
      Flag==I2C_STOPF || Flag==I2C_AF  || Flag==I2C_ENDAD)
  //flags that need a read of the SR2 register to be cleared
  {
    // Read the SR2 register
    (void)I2Cx->SR2;
    // Two flags need a second step to be cleared
    switch (Flag)
    {
      case  I2C_ADD10: I2Cx->DR = Tmp; break;
      case  I2C_ENDAD: I2Cx->CR|=0x20; break;
    }
  }
  else if (Flag==I2C_SB || Flag==I2C_ADSL || Flag==I2C_BTF || Flag==I2C_TRA)
  //flags that need a read of the SR1 register to be cleared
  {
  	// Read the SR1 register
    (void)I2Cx->SR1;
    if (Flag==I2C_SB) I2Cx->DR=Tmp;
    else if (Flag==I2C_BTF || Flag==I2C_TRA) (void)I2Cx->DR;
  }
  else if ( Flag==I2C_M_SL || Flag==I2C_GCAL)
  //flags that need the PE bit to be cleared
  {
    I2C_OnOffConfig (I2Cx, DISABLE);
    I2C_OnOffConfig (I2Cx, ENABLE);
  }
}

/*******************************************************************************
* Function Name  : I2C_SpeedConfig
* Description    : Selects I2C clock speed and configures its corresponding mode.
* Input          : I2Cx ( I2C0 or I2C1 )
*                  Clock: I2C expected clock in Hertz.
* Return         : None.
*******************************************************************************/
void I2C_SpeedConfig (I2C_TypeDef *I2Cx, u32 Clock)
{
  u32 FCLK;
  u16 result;
  // Get the FCLK frequency using the RCCU library
  FCLK = RCCU_FrequencyValue ( RCCU_FCLK );
  // Test on speed mode
  // Update the CCR and ECCR are updated
  if (Clock <=100000)
  // Standard mode selected
  {
    result = ((FCLK/Clock)/2)-7;
    //Clear FM/SM bit
    I2Cx->CCR=result &0x7f;
  }
  else if (Clock <=400000)
  {
    // Fast mode selected
    result = ((FCLK/Clock)/3)-9;
    //set FM/SM bit
    I2Cx->CCR=result |0x80;
  }
  I2Cx->ECCR= result >>7;
}

/*******************************************************************************
* Function Name  : I2C_AddressConfig
* Description    : Defines the I2C bus address of the interface.
* Input          : I2Cx ( I2C0 or I2C1 ).
*                  Address: an u16 parameter indicating the address
*                           of the interface.
*                  Mode (I2C_Mode10,I2C_Mode7).
* Return         : None.
*******************************************************************************/
void I2C_AddressConfig (I2C_TypeDef *I2Cx, u16 Address, I2C_Addressing Mode)
{
  //Update OAR1 bit[7:1] by the lowest byte of address
  I2Cx->OAR1 = (u8)Address;

  if (Mode == I2C_Mode10)
    //Update Add8 and add9 bits in OAR2
    I2Cx->OAR2 |= (Address & 0x0300)>>7;
}

/*******************************************************************************
* Function Name  : I2C_FCLKConfig
* Description    : Configures frequency bits according to RCLK frequency.
*                  the I2C selected must be disabled
* Input          : I2Cx ( I2C0 or I2C1 )
* Return         : None.
*******************************************************************************/
void I2C_FCLKConfig (I2C_TypeDef *I2Cx)
{
  u32 FCLK;
     // Get the FCLK frequency using the RCCU library
  FCLK = RCCU_FrequencyValue ( RCCU_FCLK );
     // Test the value of the FCLK and affect FR0,FR1&FR2 of the OAR2 register
  if (FCLK > 5000000)
    {
    if (FCLK <10000000)
      I2Cx->OAR2 |= 0x00;
    else if (FCLK <16670000)
      I2Cx->OAR2 |= 0x20;
    else if (FCLK < 26670000)
      I2Cx->OAR2 |= 0x40;
    else if (FCLK <40000000)
      I2Cx->OAR2 |= 0x60;
    else if (FCLK < 53330000)
      I2Cx->OAR2 |= 0x80;
    else if (FCLK < 66000000)
      I2Cx->OAR2 |= 0xA0;
    else if (FCLK <80000000)
      I2Cx->OAR2 |= 0xC0;
    else if (FCLK <100000000)
      I2Cx->OAR2 |= 0xE0;
   }
}

/*******************************************************************************
* Function Name  : I2C_AddressSend
* Description    : Transmits the address byte to select the slave device.
* Input          : I2Cx ( I2C0 or I2C1 )
*                  Address: an u16 parameter indicating the slave address
*                  Mode (I2C_Mode10,I2C_Mode7).
*                  Direction (I2C_RX,I2C_TX).
* Return         : None.
********************************************************************************/
void I2C_AddressSend (I2C_TypeDef *I2Cx, u16 Address, I2C_Addressing Mode, I2C_Direction Direction)
{
  if (Mode == I2C_Mode10 )
  //10 bit addressing mode
  {
    // Update the DR register by generated header
    I2Cx->DR = ((Address>>7)|0xf0)&0xfe;
    //Wait till I2C_ADD10 flag is set
    while ((I2Cx->SR1&0x40)==0);
    //clear I2C_ADD10 flag
    (void)I2Cx->SR2;
    I2Cx->DR=(u8)Address;
    //Test on the direction to define the read/write bit
    if (Direction == I2C_RX)
    {
      //Wait till I2C_ENDAD flag is set
      while ((I2Cx->SR2&0x20)==0);
      I2Cx->CR|=0x20;
      //Repeated START Generate
      I2C_STARTGenerate (I2Cx, ENABLE);
      //Test on SB flag status
      while ((I2Cx->SR1&0x01)==0);
      I2Cx->DR = ((Address>>7)|0xf1);
    }
  }
  else
  // 7 bit addressing mode
  {
    if (Direction == I2C_RX) Address|=0x01; else Address&=~0x01;
    I2Cx->DR=(u8)Address;
  }
}

/*******************************************************************************