peripherals: add I2C lib [#2]
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Vasily Davydov
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4fda9a4128
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160
source/shoh/src/peripherals/I2C.cpp
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160
source/shoh/src/peripherals/I2C.cpp
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/*
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* I2C.cpp
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*
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* Created on: 21.2.2016
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* Author: krl
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* Based on example provided by NXP Semiconductors. See copyright notice
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* below.
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*/
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/*
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* @brief I2CM bus master example using polling mode
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*
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* @note
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* Copyright(C) NXP Semiconductors, 2014
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* All rights reserved.
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*
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* @par
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* Software that is described herein is for illustrative purposes only
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* which provides customers with programming information regarding the
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* LPC products. This software is supplied "AS IS" without any warranties of
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* any kind, and NXP Semiconductors and its licensor disclaim any and
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* all warranties, express or implied, including all implied warranties of
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* merchantability, fitness for a particular purpose and non-infringement of
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* intellectual property rights. NXP Semiconductors assumes no responsibility
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* or liability for the use of the software, conveys no license or rights under
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* any patent, copyright, mask work right, or any other intellectual property
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* rights in or to any products. NXP Semiconductors reserves the right to make
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* changes in the software without notification. NXP Semiconductors also makes
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* no representation or warranty that such application will be suitable for the
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* specified use without further testing or modification.
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*
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* @par
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* Permission to use, copy, modify, and distribute this software and its
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* documentation is hereby granted, under NXP Semiconductors' and its
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* licensor's relevant copyrights in the software, without fee, provided that
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* it is used in conjunction with NXP Semiconductors microcontrollers. This
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* copyright, permission, and disclaimer notice must appear in all copies of
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* this code.
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*/
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#include "I2C.h"
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I2C::I2C (const I2C_config &cfg) : device (nullptr)
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{
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// if(cfg.device_number == 0) {
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device = LPC_I2C0;
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// board init must have been called before the pins can be configured
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Chip_IOCON_PinMuxSet (LPC_IOCON, 0, 22, IOCON_DIGMODE_EN | cfg.i2c_mode);
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Chip_IOCON_PinMuxSet (LPC_IOCON, 0, 23, IOCON_DIGMODE_EN | cfg.i2c_mode);
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Chip_SWM_EnableFixedPin (SWM_FIXED_I2C0_SCL);
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Chip_SWM_EnableFixedPin (SWM_FIXED_I2C0_SDA);
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//}
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// else {
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// currently we support only I2C number 0
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//}
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if (LPC_I2C0)
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{
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/* Enable I2C clock and reset I2C peripheral - the boot ROM does not
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do this */
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Chip_I2C_Init (LPC_I2C0);
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/* Setup clock rate for I2C */
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Chip_I2C_SetClockDiv (LPC_I2C0, cfg.clock_divider);
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/* Setup I2CM transfer rate */
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Chip_I2CM_SetBusSpeed (LPC_I2C0, cfg.speed);
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/* Enable Master Mode */
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Chip_I2CM_Enable (LPC_I2C0);
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}
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}
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I2C::~I2C ()
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{
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// TODO Auto-generated destructor stub
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}
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bool
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I2C::write (uint8_t devAddr, uint8_t *txBuffPtr, uint16_t txSize)
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{
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return transaction (devAddr, txBuffPtr, txSize, nullptr, 0);
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}
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bool
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I2C::read (uint8_t devAddr, uint8_t *rxBuffPtr, uint16_t rxSize)
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{
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return transaction (devAddr, nullptr, 0, rxBuffPtr, rxSize);
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}
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bool
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I2C::transaction (uint8_t devAddr, uint8_t *txBuffPtr, uint16_t txSize,
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uint8_t *rxBuffPtr, uint16_t rxSize)
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{
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I2CM_XFER_T i2cmXferRec;
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// make sure that master is idle
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while (!Chip_I2CM_IsMasterPending (LPC_I2C0))
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;
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/* Setup I2C transfer record */
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i2cmXferRec.slaveAddr = devAddr;
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i2cmXferRec.status = 0;
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i2cmXferRec.txSz = txSize;
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i2cmXferRec.rxSz = rxSize;
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i2cmXferRec.txBuff = txBuffPtr;
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i2cmXferRec.rxBuff = rxBuffPtr;
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I2CM_XferBlocking (LPC_I2C0, &i2cmXferRec);
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// Chip_I2CM_XferBlocking returns before stop condition is fully completed
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// therefore we need to wait for master to be idle when doing back-to-back
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// transactions (see beginning of the function)
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/* Test for valid operation */
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if (i2cmXferRec.status == I2CM_STATUS_OK)
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{
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return true;
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}
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else
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{
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return false;
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}
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}
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/* Transmit and Receive data in master mode */
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/* This duplicates (and combines) the functionality of Chip_I2CM_Xfer and
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* Chip_I2CM_XferBlocking with a modification that allows us to do a zero
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* length write (needed to use honeywell humidity/temp sensor)
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*/
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uint32_t
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I2C::I2CM_XferBlocking (LPC_I2C_T *pI2C, I2CM_XFER_T *xfer)
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{
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uint32_t ret = 0;
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/* start transfer */
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/* set the transfer status as busy */
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xfer->status = I2CM_STATUS_BUSY;
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/* Clear controller state. */
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Chip_I2CM_ClearStatus (pI2C, I2C_STAT_MSTRARBLOSS | I2C_STAT_MSTSTSTPERR);
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/* Write Address and RW bit to data register */
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// Chip_I2CM_WriteByte(pI2C, (xfer->slaveAddr << 1) | (xfer->txSz == 0)); //
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// original NXP version
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// krl : both read and write lenght is 0 --> write (for honeywell temp
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// sensor)
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Chip_I2CM_WriteByte (pI2C, (xfer->slaveAddr << 1)
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| (xfer->txSz == 0 && xfer->rxSz != 0));
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/* Enter to Master Transmitter mode */
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Chip_I2CM_SendStart (pI2C);
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while (ret == 0)
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{
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/* wait for status change interrupt */
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while (!Chip_I2CM_IsMasterPending (pI2C))
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{
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}
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/* call state change handler */
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ret = Chip_I2CM_XferHandler (pI2C, xfer);
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}
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return ret;
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}
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33
source/shoh/src/peripherals/I2C.h
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33
source/shoh/src/peripherals/I2C.h
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@ -0,0 +1,33 @@
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/*
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* I2C.h
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*
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* Created on: 21.2.2016
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* Author: krl
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*/
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#ifndef I2C_H_
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#define I2C_H_
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#include "chip.h"
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struct I2C_config {
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unsigned int device_number;
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unsigned int speed;
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unsigned int clock_divider;
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unsigned int i2c_mode;
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I2C_config(unsigned int dn, unsigned int sp, unsigned int cd): device_number(dn), speed(sp), clock_divider(cd), i2c_mode(IOCON_SFI2C_EN) {};
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};
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class I2C {
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public:
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I2C(const I2C_config &cfg);
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virtual ~I2C();
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bool transaction(uint8_t devAddr, uint8_t *txBuffPtr, uint16_t txSize, uint8_t *rxBuffPtr, uint16_t rxSize);
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bool write(uint8_t devAddr, uint8_t *txBuffPtr, uint16_t txSize);
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bool read(uint8_t devAddr, uint8_t *rxBuffPtr, uint16_t rxSize);
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private:
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LPC_I2C_T *device;
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static uint32_t I2CM_XferBlocking(LPC_I2C_T *pI2C, I2CM_XFER_T *xfer);
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};
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#endif /* I2C_H_ */
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