//***************************************************************************** // // i2c.c - Driver for Inter-IC (I2C) bus block. // // Copyright (c) 2005,2006 Luminary Micro, Inc. All rights reserved. // // Software License Agreement // // Luminary Micro, Inc. (LMI) is supplying this software for use solely and // exclusively on LMI's Stellaris Family of microcontroller products. // // The software is owned by LMI and/or its suppliers, and is protected under // applicable copyright laws. All rights are reserved. Any use in violation // of the foregoing restrictions may subject the user to criminal sanctions // under applicable laws, as well as to civil liability for the breach of the // terms and conditions of this license. // // THIS SOFTWARE IS PROVIDED "AS IS". NO WARRANTIES, WHETHER EXPRESS, IMPLIED // OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. // LMI SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR // CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER. // // This is part of revision 991 of the Stellaris Driver Library. // //***************************************************************************** //***************************************************************************** // //! \addtogroup i2c_api //! @{ // //***************************************************************************** #include "../hw_i2c.h" #include "../hw_ints.h" #include "../hw_memmap.h" #include "../hw_types.h" #include "debug.h" #include "i2c.h" #include "interrupt.h" #include "sysctl.h" //***************************************************************************** // //! Initializes the I2C Master block. //! //! \param ulBase base address of the I2C Master module //! \param bFast set up for fast data transfers //! //! This function initializes operation of the I2C Master block. Upon //! successful initialization of the I2C block, this function will have //! set the bus speed for the master, and will have enabled the I2C Master //! block. //! //! If the parameter \e bFast is \b true, then the master block will be //! set up to transfer data at 400 kbps; otherwise, it will be set up to //! transfer data at 100 kbps. //! //! The I2C clocking is dependent upon the system clock rate returned by //! SysCtlClockGet(); if it does not return the correct system clock rate then //! the I2C clock rate will be incorrect. //! //! \return None. // //***************************************************************************** #if defined(GROUP_masterinit) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CMasterInit(unsigned long ulBase, tBoolean bFast) { unsigned long ulSysClk; unsigned long ulSCLFreq; unsigned long ulTPR; // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); // // Must enable the device before doing anything else. // I2CMasterEnable(ulBase); // // Get the system clock speed. // ulSysClk = SysCtlClockGet(); // // Get the desired SCL speed. // if(bFast == true) { ulSCLFreq = I2C_SCL_FAST; } else { ulSCLFreq = I2C_SCL_STANDARD; } // // Compute the clock divider that achieves the fastest speed less than or // equal to the desired speed. The numerator is biases to favor a larger // clock divider so that the resulting clock is always less than or equal // to the desired clock, never greater. // ulTPR = (((ulSysClk + (2 * I2C_MASTER_TPR_SCL * ulSCLFreq) - 1) / (2 * I2C_MASTER_TPR_SCL * ulSCLFreq)) - 1); HWREG(ulBase + I2C_MASTER_O_TPR) = ulTPR; } #endif //***************************************************************************** // //! Initializes the I2C Slave block. //! //! \param ulBase base address of the I2C Slave module //! \param ucSlaveAddr 7-bit slave address //! //! This function initializes operation of the I2C Slave block. Upon //! successful initialization of the I2C blocks, this function will have //! set the slave address and have enabled the I2C Slave block. //! //! The parameter \e ucSlaveAddr is the value that will be compared //! against the slave address sent by an I2C master. //! //! \return None. // //***************************************************************************** #if defined(GROUP_slaveinit) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CSlaveInit(unsigned long ulBase, unsigned char ucSlaveAddr) { // // Check the arguments. // ASSERT(ulBase == I2C_SLAVE_BASE); ASSERT(!(ucSlaveAddr & 0x80)); // // Must enable the device before doing anything else. // I2CSlaveEnable(ulBase); // // Set up the slave address. // HWREG(ulBase + I2C_SLAVE_O_OAR) = ucSlaveAddr; } #endif //***************************************************************************** // //! Enables the I2C Master block. //! //! \param ulBase base address of the I2C Master module //! //! This will enable operation of the I2C Master block. //! //! \return None. // //***************************************************************************** #if defined(GROUP_masterenable) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CMasterEnable(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); // // Enable the master block. // HWREG(ulBase + I2C_MASTER_O_CR) |= I2C_MASTER_CR_MFE; } #endif //***************************************************************************** // //! Enables the I2C Slave block. //! //! \param ulBase base address of the I2C Slave module //! //! This will enable operation of the I2C Slave block. //! //! \return None. // //***************************************************************************** #if defined(GROUP_slaveenable) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CSlaveEnable(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_SLAVE_BASE); // // Enable the clock to the slave block. // HWREG(ulBase - I2C_O_SLAVE + I2C_MASTER_O_CR) |= I2C_MASTER_CR_SFE; // // Enable the slave. // HWREG(ulBase + I2C_SLAVE_O_CSR) = I2C_SLAVE_CSR_DA; } #endif //***************************************************************************** // //! Disables the I2C master block. //! //! \param ulBase base address of the I2C Master module //! //! This will disable operation of the I2C master block. //! //! \return None. // //***************************************************************************** #if defined(GROUP_masterdisable) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CMasterDisable(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); // // Disable the master block. // HWREG(ulBase + I2C_MASTER_O_CR) &= ~(I2C_MASTER_CR_MFE); } #endif //***************************************************************************** // //! Disables the I2C slave block. //! //! \param ulBase base address of the I2C Slave module //! //! This will disable operation of the I2C slave block. //! //! \return None. // //***************************************************************************** #if defined(GROUP_slavedisable) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CSlaveDisable(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_SLAVE_BASE); // // Disable the slave. // HWREG(ulBase + I2C_SLAVE_O_CSR) = 0; // // Disable the clock to the slave block. // HWREG(ulBase - I2C_O_SLAVE + I2C_MASTER_O_CR) &= ~(I2C_MASTER_CR_SFE); } #endif //***************************************************************************** // //! Registers an interrupt handler for the I2C module //! //! \param ulBase base address of the I2C module //! \param pfnHandler is a pointer to the function to be called when the //! synchronous serial interface interrupt occurs. //! //! This sets the handler to be called when an I2C interrupt occurs. This //! will enable the global interrupt in the interrupt controller; specific I2C //! interrupts must be enabled via I2CMasterIntEnable() and //! I2CSlaveIntEnable(). If necessary, it is the interrupt handler's //! responsibility to clear the interrupt source via I2CMasterIntClear() and //! I2CSlaveIntClear(). //! //! \sa IntRegister() for important information about registering interrupt //! handlers. //! //! \return None. // //***************************************************************************** #if defined(GROUP_intregister) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CIntRegister(unsigned long ulBase, void (*pfnHandler)(void)) { // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); // // Register the interrupt handler, returning an error if an error occurs. // IntRegister(INT_I2C, pfnHandler); // // Enable the I2C interrupt. // IntEnable(INT_I2C); } #endif //***************************************************************************** // //! Unregisters an interrupt handler for the I2C module. //! //! \param ulBase base address of the I2C module //! //! This function will clear the handler to be called when an I2C //! interrupt occurs. This will also mask off the interrupt in the interrupt //! controller so that the interrupt handler no longer is called. //! //! \sa IntRegister() for important information about registering interrupt //! handlers. //! //! \return None. // //***************************************************************************** #if defined(GROUP_intunregister) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CIntUnregister(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); // // Disable the interrupt. // IntDisable(INT_I2C); // // Unregister the interrupt handler. // IntUnregister(INT_I2C); } #endif //***************************************************************************** // //! Enables the I2C Master interrupt. //! //! \param ulBase base address of the I2C Master module //! //! Enables the I2C Master interrupt source. //! //! \return None. // //***************************************************************************** #if defined(GROUP_masterintenable) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CMasterIntEnable(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); // // Enable the master interrupt. // HWREG(ulBase + I2C_MASTER_O_IMR) = 1; } #endif //***************************************************************************** // //! Enables the I2C Slave interrupt. //! //! \param ulBase base address of the I2C Slave module //! //! Enables the I2C Slave interrupt source. //! //! \return None. // //***************************************************************************** #if defined(GROUP_slaveintenable) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CSlaveIntEnable(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_SLAVE_BASE); // // Enable the slave interrupt. // HWREG(ulBase + I2C_SLAVE_O_IM) = 1; } #endif //***************************************************************************** // //! Disables the I2C Master interrupt. //! //! \param ulBase base address of the I2C Master module //! //! Disables the I2C Master interrupt source. //! //! \return None. // //***************************************************************************** #if defined(GROUP_masterintdisable) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CMasterIntDisable(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); // // Disable the master interrupt. // HWREG(ulBase + I2C_MASTER_O_IMR) = 0; } #endif //***************************************************************************** // //! Disables the I2C Slave interrupt. //! //! \param ulBase base address of the I2C Slave module //! //! Disables the I2C Slave interrupt source. //! //! \return None. // //***************************************************************************** #if defined(GROUP_slaveintdisable) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CSlaveIntDisable(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_SLAVE_BASE); // // Disable the slave interrupt. // HWREG(ulBase + I2C_SLAVE_O_IM) = 0; } #endif //***************************************************************************** // //! Gets the current I2C Master interrupt status. //! //! \param ulBase base address of the I2C Master module //! \param bMasked is false if the raw interrupt status is requested and //! true if the masked interrupt status is requested. //! //! This returns the interrupt status for the I2C Master module. //! Either the raw interrupt status or the status of interrupts that are //! allowed to reflect to the processor can be returned. //! //! \return The current interrupt status, returned as \b true if active //! or \b false if not active. // //***************************************************************************** #if defined(GROUP_masterintstatus) || defined(BUILD_ALL) || defined(DOXYGEN) tBoolean I2CMasterIntStatus(unsigned long ulBase, tBoolean bMasked) { // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); // // Return either the interrupt status or the raw interrupt status as // requested. // if(bMasked) { return((HWREG(ulBase + I2C_MASTER_O_MIS)) ? true : false); } else { return((HWREG(ulBase + I2C_MASTER_O_RIS)) ? true : false); } } #endif //***************************************************************************** // //! Gets the current I2C Slave interrupt status. //! //! \param ulBase base address of the I2C Slave module //! \param bMasked is false if the raw interrupt status is requested and //! true if the masked interrupt status is requested. //! //! This returns the interrupt status for the I2C Slave module. //! Either the raw interrupt status or the status of interrupts that are //! allowed to reflect to the processor can be returned. //! //! \return The current interrupt status, returned as \b true if active //! or \b false if not active. // //***************************************************************************** #if defined(GROUP_slaveintstatus) || defined(BUILD_ALL) || defined(DOXYGEN) tBoolean I2CSlaveIntStatus(unsigned long ulBase, tBoolean bMasked) { // // Check the arguments. // ASSERT(ulBase == I2C_SLAVE_BASE); // // Return either the interrupt status or the raw interrupt status as // requested. // if(bMasked) { return((HWREG(ulBase + I2C_SLAVE_O_MIS)) ? true : false); } else { return((HWREG(ulBase + I2C_SLAVE_O_RIS)) ? true : false); } } #endif //***************************************************************************** // //! Clears I2C Master interrupt sources. //! //! \param ulBase base address of the I2C Master module //! //! The I2C Master interrupt source is cleared, so that it no longer asserts. //! This must be done in the interrupt handler to keep it from being called //! again immediately upon exit. //! //! \return None. // //***************************************************************************** #if defined(GROUP_masterintclear) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CMasterIntClear(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); // // Clear the I2C master interrupt source. // HWREG(ulBase + I2C_MASTER_O_MICR) = I2C_MASTER_MICR_IC; // // Workaround for I2C master interrupt clear errata for rev B Stellaris // devices. For later devices, this write is ignored and therefore // harmless (other than the slight performance hit). // HWREG(ulBase + I2C_MASTER_O_MIS) = I2C_MASTER_MICR_IC; } #endif //***************************************************************************** // //! Clears I2C Slave interrupt sources. //! //! \param ulBase base address of the I2C Slave module //! //! The I2C Slave interrupt source is cleared, so that it no longer asserts. //! This must be done in the interrupt handler to keep it from being called //! again immediately upon exit. //! //! \return None. // //***************************************************************************** #if defined(GROUP_slaveintclear) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CSlaveIntClear(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_SLAVE_BASE); // // Clear the I2C slave interrupt source. // HWREG(ulBase + I2C_SLAVE_O_SICR) = I2C_SLAVE_SICR_IC; } #endif //***************************************************************************** // //! Sets the address that the I2C Master will place on the bus. //! //! \param ulBase base address of the I2C Master module //! \param ucSlaveAddr 7-bit slave address //! \param bReceive flag indicating the type of communication with the slave //! //! This function will set the address that the I2C Master will place on the //! bus when initiating a transaction. When the parameter \e bReceive is set //! to \b true, the address will indicate that the I2C Master is initiating //! a read from the slave; otherwise the address will indicate that the I2C //! Master is initiating a write to the slave. //! //! \return None. // //***************************************************************************** #if defined(GROUP_masterslaveaddrset) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CMasterSlaveAddrSet(unsigned long ulBase, unsigned char ucSlaveAddr, tBoolean bReceive) { // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); ASSERT(!(ucSlaveAddr & 0x80)); // // Set the address of the slave with which the master will communicate. // HWREG(ulBase + I2C_MASTER_O_SA) = (ucSlaveAddr << 1) | bReceive; } #endif //***************************************************************************** // //! Indicates whether or not the I2C Master is busy. //! //! \param ulBase base address of the I2C Master module //! //! This function returns an indication of whether or not the I2C Master is //! busy transmitting or receiving data. //! //! \return Returns \b true if the I2C Master is busy; otherwise, returns //! \b false. // //***************************************************************************** #if defined(GROUP_masterbusy) || defined(BUILD_ALL) || defined(DOXYGEN) tBoolean I2CMasterBusy(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); // // Return the busy status. // if(HWREG(ulBase + I2C_MASTER_O_CS) & I2C_MASTER_CS_BUSY) { return(true); } else { return(false); } } #endif //***************************************************************************** // //! Indicates whether or not the I2C bus is busy. //! //! \param ulBase base address of the I2C Master module //! //! This function returns an indication of whether or not the I2C bus is //! busy. This function can be used in a multi-master environment to //! determine if another master is currently using the bus. //! //! \return Returns \b true if the I2C bus is busy; otherwise, returns //! \b false. // //***************************************************************************** #if defined(GROUP_masterbusbusy) || defined(BUILD_ALL) || defined(DOXYGEN) tBoolean I2CMasterBusBusy(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); // // Return the bus busy status. // if(HWREG(ulBase + I2C_MASTER_O_CS) & I2C_MASTER_CS_BUS_BUSY) { return(true); } else { return(false); } } #endif //***************************************************************************** // //! Controls the state of the I2C Master module. //! //! \param ulBase base address of the I2C Master module //! \param ulCmd command to be issued to the I2C Master module //! //! This function is used to control the state of the Master module send and //! receive operations. The parameter \e ucCmd can be one of the following //! values: //! //! - I2C_MASTER_CMD_SINGLE_SEND //! - I2C_MASTER_CMD_SINGLE_RECEIVE //! - I2C_MASTER_CMD_BURST_SEND_START //! - I2C_MASTER_CMD_BURST_SEND_CONT //! - I2C_MASTER_CMD_BURST_SEND_FINISH //! - I2C_MASTER_CMD_BURST_SEND_ERROR_STOP //! - I2C_MASTER_CMD_BURST_RECEIVE_START //! - I2C_MASTER_CMD_BURST_RECEIVE_CONT //! - I2C_MASTER_CMD_BURST_RECEIVE_FINISH //! - I2C_MASTER_CMD_BURST_RECEIVE_ERROR_STOP //! //! \return None. // //***************************************************************************** #if defined(GROUP_mastercontrol) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CMasterControl(unsigned long ulBase, unsigned long ulCmd) { // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); ASSERT((ulCmd == I2C_MASTER_CMD_SINGLE_SEND) || (ulCmd == I2C_MASTER_CMD_SINGLE_RECEIVE) || (ulCmd == I2C_MASTER_CMD_BURST_SEND_START) || (ulCmd == I2C_MASTER_CMD_BURST_SEND_CONT) || (ulCmd == I2C_MASTER_CMD_BURST_SEND_FINISH) || (ulCmd == I2C_MASTER_CMD_BURST_SEND_ERROR_STOP) || (ulCmd == I2C_MASTER_CMD_BURST_RECEIVE_START) || (ulCmd == I2C_MASTER_CMD_BURST_RECEIVE_CONT) || (ulCmd == I2C_MASTER_CMD_BURST_RECEIVE_FINISH) || (ulCmd == I2C_MASTER_CMD_BURST_RECEIVE_ERROR_STOP)); // // Send the command. // HWREG(ulBase + I2C_MASTER_O_CS) = ulCmd; } #endif //***************************************************************************** // //! Gets the error status of the I2C Master module. //! //! \param ulBase base address of the I2C Master module //! //! This function is used to obtain the error status of the Master module //! send and receive operations. It returns one of the following values: //! //! - I2C_MASTER_ERR_NONE //! - I2C_MASTER_ERR_ADDR_ACK //! - I2C_MASTER_ERR_DATA_ACK //! - I2C_MASTER_ERR_ARB_LOST //! //! \return None. // //***************************************************************************** #if defined(GROUP_mastererr) || defined(BUILD_ALL) || defined(DOXYGEN) unsigned long I2CMasterErr(unsigned long ulBase) { unsigned long ulErr; // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); // // Get the raw error state // ulErr = HWREG(ulBase + I2C_MASTER_O_CS); // // If the I2C master is busy, then all the other bit are invalid, and // don't have an error to report. // if(ulErr & I2C_MASTER_CS_BUSY) { return(I2C_MASTER_ERR_NONE); } // // Check for errors. // if(ulErr & I2C_MASTER_CS_ERROR) { return(ulErr & (I2C_MASTER_CS_ERR_MASK)); } else { return(I2C_MASTER_ERR_NONE); } } #endif //***************************************************************************** // //! Transmits a byte from the I2C Master. //! //! \param ulBase base address of the I2C Master module //! \param ucData data to be transmitted from the I2C Master //! //! This function will place the supplied data into I2C Master Data Register. //! //! \return None. // //***************************************************************************** #if defined(GROUP_masterdataput) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CMasterDataPut(unsigned long ulBase, unsigned char ucData) { // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); // // Write the byte. // HWREG(ulBase + I2C_MASTER_O_DR) = ucData; } #endif //***************************************************************************** // //! Receives a byte that has been sent to the I2C Master. //! //! \param ulBase base address of the I2C Master module //! //! This function reads a byte of data from the I2C Master Data Register. //! //! \return Returns the byte received from by the I2C Master, cast as an //! unsigned long. // //***************************************************************************** #if defined(GROUP_masterdataget) || defined(BUILD_ALL) || defined(DOXYGEN) unsigned long I2CMasterDataGet(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_MASTER_BASE); // // Read a byte. // return(HWREG(ulBase + I2C_MASTER_O_DR)); } #endif //***************************************************************************** // //! Gets the I2C Slave module status //! //! \param ulBase base address of the I2C Slave module //! //! This function will return the action requested from a master, if any. The //! possible values returned are: //! //! - I2C_SLAVE_ACT_NONE //! - I2C_SLAVE_ACT_RREQ //! - I2C_SLAVE_ACT_TREQ //! //! where I2C_SLAVE_ACT_NONE means that no action has been requested of the //! I2C Slave module, I2C_SLAVE_ACT_RREQ means that an I2C master has sent //! data to the I2C Slave module, and I2C_SLAVE_ACT_TREQ means that an I2C //! master has requested that the I2C Slave module send data. //! //! \return None. // //***************************************************************************** #if defined(GROUP_slavestatus) || defined(BUILD_ALL) || defined(DOXYGEN) unsigned long I2CSlaveStatus(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_SLAVE_BASE); // // Return the slave status. // return(HWREG(ulBase + I2C_SLAVE_O_CSR)); } #endif //***************************************************************************** // //! Transmits a byte from the I2C Slave. //! //! \param ulBase base address of the I2C Slave module //! \param ucData data to be transmitted from the I2C Slave //! //! This function will place the supplied data into I2C Slave Data Register. //! //! \return None. // //***************************************************************************** #if defined(GROUP_slavedataput) || defined(BUILD_ALL) || defined(DOXYGEN) void I2CSlaveDataPut(unsigned long ulBase, unsigned char ucData) { // // Check the arguments. // ASSERT(ulBase == I2C_SLAVE_BASE); // // Write the byte. // HWREG(ulBase + I2C_SLAVE_O_DR) = ucData; } #endif //***************************************************************************** // //! Receives a byte that has been sent to the I2C Slave. //! //! \param ulBase base address of the I2C Slave module //! //! This function reads a byte of data from the I2C Slave Data Register. //! //! \return Returns the byte received from by the I2C Slave, cast as an //! unsigned long. // //***************************************************************************** #if defined(GROUP_slavedataget) || defined(BUILD_ALL) || defined(DOXYGEN) unsigned long I2CSlaveDataGet(unsigned long ulBase) { // // Check the arguments. // ASSERT(ulBase == I2C_SLAVE_BASE); // // Read a byte. // return(HWREG(ulBase + I2C_SLAVE_O_DR)); } #endif //***************************************************************************** // // Close the Doxygen group. //! @} // //*****************************************************************************