| /****************************************************************************** |
| * 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); |
| } |