i2c: resolve #4
This commit is contained in:
Vasily Davydov
143
I2C/src/I2C.cpp
Normal file
143
I2C/src/I2C.cpp
Normal file
@@ -0,0 +1,143 @@
|
||||
/*
|
||||
* I2C.cpp
|
||||
*
|
||||
* Created on: 21.2.2016
|
||||
* Author: krl
|
||||
* Based on example provided by NXP Semiconductors. See copyright notice below.
|
||||
*/
|
||||
|
||||
/*
|
||||
* @brief I2CM bus master example using polling mode
|
||||
*
|
||||
* @note
|
||||
* Copyright(C) NXP Semiconductors, 2014
|
||||
* All rights reserved.
|
||||
*
|
||||
* @par
|
||||
* Software that is described herein is for illustrative purposes only
|
||||
* which provides customers with programming information regarding the
|
||||
* LPC products. This software is supplied "AS IS" without any warranties of
|
||||
* any kind, and NXP Semiconductors and its licensor disclaim any and
|
||||
* all warranties, express or implied, including all implied warranties of
|
||||
* merchantability, fitness for a particular purpose and non-infringement of
|
||||
* intellectual property rights. NXP Semiconductors assumes no responsibility
|
||||
* or liability for the use of the software, conveys no license or rights under any
|
||||
* patent, copyright, mask work right, or any other intellectual property rights in
|
||||
* or to any products. NXP Semiconductors reserves the right to make changes
|
||||
* in the software without notification. NXP Semiconductors also makes no
|
||||
* representation or warranty that such application will be suitable for the
|
||||
* specified use without further testing or modification.
|
||||
*
|
||||
* @par
|
||||
* Permission to use, copy, modify, and distribute this software and its
|
||||
* documentation is hereby granted, under NXP Semiconductors' and its
|
||||
* licensor's relevant copyrights in the software, without fee, provided that it
|
||||
* is used in conjunction with NXP Semiconductors microcontrollers. This
|
||||
* copyright, permission, and disclaimer notice must appear in all copies of
|
||||
* this code.
|
||||
*/
|
||||
|
||||
#include "I2C.h"
|
||||
|
||||
|
||||
I2C::I2C(const I2C_config &cfg): device(nullptr) {
|
||||
if(cfg.device_number == 0) {
|
||||
device = LPC_I2C0;
|
||||
// board init must have been called before the pins can be configured
|
||||
Chip_IOCON_PinMuxSet(LPC_IOCON, 0, 22, IOCON_DIGMODE_EN | cfg.i2c_mode);
|
||||
Chip_IOCON_PinMuxSet(LPC_IOCON, 0, 23, IOCON_DIGMODE_EN | cfg.i2c_mode);
|
||||
Chip_SWM_EnableFixedPin(SWM_FIXED_I2C0_SCL);
|
||||
Chip_SWM_EnableFixedPin(SWM_FIXED_I2C0_SDA);
|
||||
}
|
||||
else {
|
||||
// currently we support only I2C number 0
|
||||
}
|
||||
|
||||
if(device) {
|
||||
/* Enable I2C clock and reset I2C peripheral - the boot ROM does not
|
||||
do this */
|
||||
Chip_I2C_Init(device);
|
||||
|
||||
/* Setup clock rate for I2C */
|
||||
Chip_I2C_SetClockDiv(device, cfg.clock_divider);
|
||||
|
||||
/* Setup I2CM transfer rate */
|
||||
Chip_I2CM_SetBusSpeed(device, cfg.speed);
|
||||
|
||||
/* Enable Master Mode */
|
||||
Chip_I2CM_Enable(device);
|
||||
}
|
||||
}
|
||||
|
||||
I2C::~I2C() {
|
||||
// TODO Auto-generated destructor stub
|
||||
}
|
||||
|
||||
bool I2C::write(uint8_t devAddr, uint8_t *txBuffPtr, uint16_t txSize)
|
||||
{
|
||||
return transaction(devAddr, txBuffPtr, txSize, nullptr, 0);
|
||||
}
|
||||
|
||||
bool I2C::read(uint8_t devAddr, uint8_t *rxBuffPtr, uint16_t rxSize)
|
||||
{
|
||||
return transaction(devAddr, nullptr, 0, rxBuffPtr, rxSize);
|
||||
}
|
||||
|
||||
|
||||
bool I2C::transaction(uint8_t devAddr, uint8_t *txBuffPtr, uint16_t txSize, uint8_t *rxBuffPtr, uint16_t rxSize) {
|
||||
I2CM_XFER_T i2cmXferRec;
|
||||
|
||||
// make sure that master is idle
|
||||
while(!Chip_I2CM_IsMasterPending(device));
|
||||
|
||||
/* Setup I2C transfer record */
|
||||
i2cmXferRec.slaveAddr = devAddr;
|
||||
i2cmXferRec.status = 0;
|
||||
i2cmXferRec.txSz = txSize;
|
||||
i2cmXferRec.rxSz = rxSize;
|
||||
i2cmXferRec.txBuff = txBuffPtr;
|
||||
i2cmXferRec.rxBuff = rxBuffPtr;
|
||||
|
||||
I2CM_XferBlocking(device, &i2cmXferRec);
|
||||
// Chip_I2CM_XferBlocking returns before stop condition is fully completed
|
||||
// therefore we need to wait for master to be idle when doing back-to-back transactions (see beginning of the function)
|
||||
|
||||
/* Test for valid operation */
|
||||
if (i2cmXferRec.status == I2CM_STATUS_OK) {
|
||||
return true;
|
||||
}
|
||||
else {
|
||||
return false;
|
||||
}
|
||||
}
|
||||
|
||||
/* Transmit and Receive data in master mode */
|
||||
/* This duplicates (and combines) the functionality of Chip_I2CM_Xfer and Chip_I2CM_XferBlocking with a modification
|
||||
* that allows us to do a zero length write (needed to use honeywell humidity/temp sensor)
|
||||
*/
|
||||
uint32_t I2C::I2CM_XferBlocking(LPC_I2C_T *pI2C, I2CM_XFER_T *xfer)
|
||||
{
|
||||
uint32_t ret = 0;
|
||||
/* start transfer */
|
||||
|
||||
/* set the transfer status as busy */
|
||||
xfer->status = I2CM_STATUS_BUSY;
|
||||
/* Clear controller state. */
|
||||
Chip_I2CM_ClearStatus(pI2C, I2C_STAT_MSTRARBLOSS | I2C_STAT_MSTSTSTPERR);
|
||||
/* Write Address and RW bit to data register */
|
||||
//Chip_I2CM_WriteByte(pI2C, (xfer->slaveAddr << 1) | (xfer->txSz == 0)); // original NXP version
|
||||
// krl : both read and write lenght is 0 --> write (for honeywell temp sensor)
|
||||
Chip_I2CM_WriteByte(pI2C, (xfer->slaveAddr << 1) | (xfer->txSz == 0 && xfer->rxSz != 0));
|
||||
/* Enter to Master Transmitter mode */
|
||||
Chip_I2CM_SendStart(pI2C);
|
||||
|
||||
while (ret == 0) {
|
||||
/* wait for status change interrupt */
|
||||
while (!Chip_I2CM_IsMasterPending(pI2C)) {}
|
||||
/* call state change handler */
|
||||
ret = Chip_I2CM_XferHandler(pI2C, xfer);
|
||||
}
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
||||
Reference in New Issue
Block a user