blob: 0d254fbd778464ca2c000f950690ad922533ad5d [file] [log] [blame]
/******************************************************************************
* Filename: i2c.c
* Revised: 2017-04-26 18:27:45 +0200 (Wed, 26 Apr 2017)
* Revision: 48852
*
* Description: Driver for the I2C module
*
* Copyright (c) 2015 - 2017, Texas Instruments Incorporated
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1) Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2) Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3) Neither the name of the ORGANIZATION nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************/
#include "i2c.h"
//*****************************************************************************
//
// Handle support for DriverLib in ROM:
// This section will undo prototype renaming made in the header file
//
//*****************************************************************************
#if !defined(DOXYGEN)
#undef I2CMasterInitExpClk
#define I2CMasterInitExpClk NOROM_I2CMasterInitExpClk
#undef I2CMasterErr
#define I2CMasterErr NOROM_I2CMasterErr
#undef I2CIntRegister
#define I2CIntRegister NOROM_I2CIntRegister
#undef I2CIntUnregister
#define I2CIntUnregister NOROM_I2CIntUnregister
#endif
//*****************************************************************************
//
// Initializes the I2C Master block
//
//*****************************************************************************
void
I2CMasterInitExpClk(uint32_t ui32Base, uint32_t ui32I2CClk,
bool bFast)
{
uint32_t ui32SCLFreq;
uint32_t ui32TPR;
// Check the arguments.
ASSERT(I2CBaseValid(ui32Base));
// Must enable the device before doing anything else.
I2CMasterEnable(I2C0_BASE);
// Get the desired SCL speed.
if(bFast == true)
{
ui32SCLFreq = 400000;
}
else
{
ui32SCLFreq = 100000;
}
// Compute the clock divider that achieves the fastest speed less than or
// equal to the desired speed. The numerator is biased to favor a larger
// clock divider so that the resulting clock is always less than or equal
// to the desired clock, never greater.
ui32TPR = ((ui32I2CClk + (2 * 10 * ui32SCLFreq) - 1) / (2 * 10 * ui32SCLFreq)) - 1;
HWREG(I2C0_BASE + I2C_O_MTPR) = ui32TPR;
}
//*****************************************************************************
//
// Gets the error status of the I2C Master module
//
//*****************************************************************************
uint32_t
I2CMasterErr(uint32_t ui32Base)
{
uint32_t ui32Err;
// Check the arguments.
ASSERT(I2CBaseValid(ui32Base));
// Get the raw error state.
ui32Err = HWREG(I2C0_BASE + I2C_O_MSTAT);
// If the I2C master is busy, then all the other status bits are invalid,
// and there is no error to report.
if(ui32Err & I2C_MSTAT_BUSY)
{
return(I2C_MASTER_ERR_NONE);
}
// Check for errors.
if(ui32Err & (I2C_MSTAT_ERR | I2C_MSTAT_ARBLST))
{
return(ui32Err & (I2C_MSTAT_ARBLST | I2C_MSTAT_DATACK_N | I2C_MSTAT_ADRACK_N));
}
else
{
return(I2C_MASTER_ERR_NONE);
}
}
//*****************************************************************************
//
// Registers an interrupt handler for the I2C module
//
//*****************************************************************************
void
I2CIntRegister(uint32_t ui32Base, void (*pfnHandler)(void))
{
uint32_t ui32Int;
// Check the arguments.
ASSERT(I2CBaseValid(ui32Base));
// Get the interrupt number.
ui32Int = INT_I2C_IRQ;
// Register the interrupt handler, returning an error if an error occurs.
IntRegister(ui32Int, pfnHandler);
// Enable the I2C interrupt.
IntEnable(ui32Int);
}
//*****************************************************************************
//
// Unregisters an interrupt handler for the I2C module
//
//*****************************************************************************
void
I2CIntUnregister(uint32_t ui32Base)
{
uint32_t ui32Int;
// Check the arguments.
ASSERT(I2CBaseValid(ui32Base));
// Get the interrupt number.
ui32Int = INT_I2C_IRQ;
// Disable the interrupt.
IntDisable(ui32Int);
// Unregister the interrupt handler.
IntUnregister(ui32Int);
}