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/*
* Copyright (c) 2015, Freescale Semiconductor, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* o Redistributions of source code must retain the above copyright notice, this list
* of conditions and the following disclaimer.
*
* o 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.
*
* o Neither the name of Freescale Semiconductor, Inc. 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 "FreeRTOS.h"
#include "semphr.h"
#include "device_imx.h"
#include "i2c_imx.h"
#include "board.h"
typedef struct _i2c_state {
const uint8_t* cmdBuff; /*!< The buffer of I2C command. */
const uint8_t* txBuff; /*!< The buffer of data being sent.*/
uint8_t* rxBuff; /*!< The buffer of received data. */
uint32_t cmdSize; /*!< The remaining number of commands to be transmitted. */
uint32_t txSize; /*!< The remaining number of bytes to be transmitted. */
uint32_t rxSize; /*!< The remaining number of bytes to be received. */
bool isBusy; /*!< True if there is an active transmission. */
uint32_t operateDir; /*!< Overall I2C bus operating direction. */
uint32_t currentDir; /*!< Current Data transfer direction. */
uint32_t currentMode; /*!< Current I2C Bus role of this module. */
SemaphoreHandle_t xSemaphore; /*!< I2C internal synchronize semaphore. */
} i2c_state_t;
/* I2C runtime state structure */
static volatile i2c_state_t i2cState;
void I2C_XFER_Config(i2c_init_config_t* initConfig)
{
/* Initialize I2C state structure content. */
i2cState.cmdBuff = 0;
i2cState.txBuff = 0;
i2cState.rxBuff = 0;
i2cState.cmdSize = 0;
i2cState.txSize = 0;
i2cState.rxSize = 0;
i2cState.isBusy = false;
i2cState.operateDir = i2cDirectionReceive;
i2cState.currentDir = i2cDirectionReceive;
i2cState.currentMode = i2cModeSlave;
i2cState.xSemaphore = xSemaphoreCreateBinary();
/* Initialize I2C baud rate, mode, transfer direction and slave address. */
I2C_Init(BOARD_I2C_BASEADDR, initConfig);
/* Set I2C Interrupt priority */
NVIC_SetPriority(BOARD_I2C_IRQ_NUM, 3);
/* Call core API to enable the IRQ. */
NVIC_EnableIRQ(BOARD_I2C_IRQ_NUM);
/* Finally, enable the I2C module */
I2C_Enable(BOARD_I2C_BASEADDR);
}
bool I2C_XFER_SendDataBlocking(const uint8_t* cmdBuff, uint32_t cmdSize,
const uint8_t* txBuffer, uint32_t txSize)
{
if ((i2cState.isBusy) || (0 == txSize))
return false;
/* Initialize i2c transfer struct */
i2cState.cmdBuff = cmdBuff;
i2cState.cmdSize = cmdSize;
i2cState.txBuff = txBuffer;
i2cState.txSize = txSize;
i2cState.isBusy = true;
i2cState.operateDir = i2cDirectionTransmit;
/* Clear I2C interrupt flag to avoid spurious interrupt */
I2C_ClearStatusFlag(BOARD_I2C_BASEADDR, i2cStatusInterrupt);
if (I2C_GetStatusFlag(BOARD_I2C_BASEADDR, i2cStatusBusBusy))
{
/* Reset i2c transfer state. */
i2cState.operateDir = i2cDirectionReceive;
i2cState.isBusy = false;
return false;
}
/* Set I2C work under Tx mode */
I2C_SetDirMode(BOARD_I2C_BASEADDR, i2cDirectionTransmit);
i2cState.currentDir = i2cDirectionTransmit;
/* Switch to Master Mode and Send Start Signal. */
I2C_SetWorkMode(BOARD_I2C_BASEADDR, i2cModeMaster);
i2cState.currentMode = i2cModeMaster;
if (0 != cmdSize)
{
I2C_WriteByte(BOARD_I2C_BASEADDR, *i2cState.cmdBuff);
i2cState.cmdBuff++;
i2cState.cmdSize--;
}
else
{
I2C_WriteByte(BOARD_I2C_BASEADDR, *i2cState.txBuff);
i2cState.txBuff++;
i2cState.txSize--;
}
/* Enable I2C interrupt, subsequent data transfer will be handled in ISR. */
I2C_SetIntCmd(BOARD_I2C_BASEADDR, true);
/* Wait until send data finish. */
xSemaphoreTake(i2cState.xSemaphore, portMAX_DELAY);
return true;
}
uint32_t I2C_XFER_GetSendStatus(void)
{
return i2cState.txSize;
}
bool I2C_XFER_ReceiveDataBlocking(const uint8_t* cmdBuff, uint32_t cmdSize,
uint8_t* rxBuffer, uint32_t rxSize)
{
if ((i2cState.isBusy) || (0 == rxSize))
return false;
/* Initialize i2c transfer struct */
i2cState.cmdBuff = cmdBuff;
i2cState.cmdSize = cmdSize;
i2cState.rxBuff = rxBuffer;
i2cState.rxSize = rxSize;
i2cState.isBusy = true;
i2cState.operateDir = i2cDirectionReceive;
/* Clear I2C interrupt flag to avoid spurious interrupt */
I2C_ClearStatusFlag(BOARD_I2C_BASEADDR, i2cStatusInterrupt);
if (I2C_GetStatusFlag(BOARD_I2C_BASEADDR, i2cStatusBusBusy))
{
/* Reset i2c transfer state. */
i2cState.operateDir = i2cDirectionReceive;
i2cState.isBusy = false;
return false;
}
/* Set I2C work under Tx mode */
I2C_SetDirMode(BOARD_I2C_BASEADDR, i2cDirectionTransmit);
i2cState.currentDir = i2cDirectionTransmit;
/* Switch to Master Mode and Send Start Signal. */
I2C_SetWorkMode(BOARD_I2C_BASEADDR, i2cModeMaster);
i2cState.currentMode = i2cModeMaster;
/* Is there command to be sent before receive data? */
if (0 != i2cState.cmdSize)
{
if (1 == i2cState.cmdSize)
I2C_SendRepeatStart(BOARD_I2C_BASEADDR);
I2C_WriteByte(BOARD_I2C_BASEADDR, *i2cState.cmdBuff);
i2cState.cmdBuff++;
i2cState.cmdSize--;
}
else
{
/* Change to receive state. */
I2C_SetDirMode(BOARD_I2C_BASEADDR, i2cDirectionReceive);
i2cState.currentDir = i2cDirectionReceive;
if (1 == rxSize)
/* Send Nack */
I2C_SetAckBit(BOARD_I2C_BASEADDR, false);
else
/* Send Ack */
I2C_SetAckBit(BOARD_I2C_BASEADDR, true);
/* dummy read to clock in 1st byte */
I2C_ReadByte(BOARD_I2C_BASEADDR);
}
/* Enable I2C interrupt, subsequent data transfer will be handled in ISR. */
I2C_SetIntCmd(BOARD_I2C_BASEADDR, true);
/* Wait until receive data finish. */
xSemaphoreTake(i2cState.xSemaphore, portMAX_DELAY);
return true;
}
uint32_t I2C_XFER_GetReceiveStatus(void)
{
return i2cState.rxSize;
}
void BOARD_I2C_HANDLER(void)
{
BaseType_t xHigherPriorityTaskWoken = pdFALSE;
/* Clear interrupt flag. */
I2C_ClearStatusFlag(BOARD_I2C_BASEADDR, i2cStatusInterrupt);
/* Exit the ISR if no transfer is happening for this instance. */
if (!i2cState.isBusy)
return;
if (i2cModeMaster == i2cState.currentMode)
{
if (i2cDirectionTransmit == i2cState.currentDir)
{
if ((I2C_GetStatusFlag(BOARD_I2C_BASEADDR, i2cStatusReceivedAck)) ||
((0 == i2cState.txSize) && (0 == i2cState.cmdSize)))
{
if ((i2cDirectionTransmit == i2cState.operateDir) ||
(I2C_GetStatusFlag(BOARD_I2C_BASEADDR, i2cStatusReceivedAck)))
{
/* Switch to Slave mode and Generate a Stop Signal. */
I2C_SetWorkMode(BOARD_I2C_BASEADDR, i2cModeSlave);
i2cState.currentMode = i2cModeSlave;
/* Switch back to Rx direction. */
I2C_SetDirMode(BOARD_I2C_BASEADDR, i2cDirectionReceive);
i2cState.currentDir = i2cDirectionReceive;
/* Close I2C interrupt. */
I2C_SetIntCmd(BOARD_I2C_BASEADDR, false);
/* Release I2C Bus. */
i2cState.isBusy = false;
xSemaphoreGiveFromISR(i2cState.xSemaphore, &xHigherPriorityTaskWoken);
}
else
{
/* Switch back to Rx direction. */
I2C_SetDirMode(BOARD_I2C_BASEADDR, i2cDirectionReceive);
i2cState.currentDir = i2cDirectionReceive;
if (1 == i2cState.rxSize)
/* Send Nack */
I2C_SetAckBit(BOARD_I2C_BASEADDR, false);
else
/* Send Ack */
I2C_SetAckBit(BOARD_I2C_BASEADDR, true);
/* dummy read to clock in 1st byte */
*i2cState.rxBuff = I2C_ReadByte(BOARD_I2C_BASEADDR);
}
}
else
{
if (0 != i2cState.cmdSize)
{
if ((1 == i2cState.cmdSize) && (i2cDirectionReceive == i2cState.operateDir))
I2C_SendRepeatStart(BOARD_I2C_BASEADDR);
I2C_WriteByte(BOARD_I2C_BASEADDR, *i2cState.cmdBuff);
i2cState.cmdBuff++;
i2cState.cmdSize--;
}
else
{
I2C_WriteByte(BOARD_I2C_BASEADDR, *i2cState.txBuff);
i2cState.txBuff++;
i2cState.txSize--;
}
}
}
else
{
/* Normal read operation. */
if (2 == i2cState.rxSize)
/* Send Nack */
I2C_SetAckBit(BOARD_I2C_BASEADDR, false);
else
/* Send Nack */
I2C_SetAckBit(BOARD_I2C_BASEADDR, true);
if (1 == i2cState.rxSize)
{
/* Switch back to Tx direction to avoid additional I2C bus read. */
I2C_SetDirMode(BOARD_I2C_BASEADDR, i2cDirectionTransmit);
i2cState.currentDir = i2cDirectionTransmit;
}
*i2cState.rxBuff = I2C_ReadByte(BOARD_I2C_BASEADDR);
i2cState.rxBuff++;
i2cState.rxSize--;
/* receive finished. */
if (0 == i2cState.rxSize)
{
/* Switch to Slave mode and Generate a Stop Signal. */
I2C_SetWorkMode(BOARD_I2C_BASEADDR, i2cModeSlave);
i2cState.currentMode = i2cModeSlave;
/* Switch back to Rx direction. */
I2C_SetDirMode(BOARD_I2C_BASEADDR, i2cDirectionReceive);
i2cState.currentDir = i2cDirectionReceive;
/* Close I2C interrupt. */
I2C_SetIntCmd(BOARD_I2C_BASEADDR, false);
/* Release I2C Bus. */
i2cState.isBusy = false;
/* Release I2C Sem4 */
xSemaphoreGiveFromISR(i2cState.xSemaphore, &xHigherPriorityTaskWoken);
}
}
}
}
/*******************************************************************************
* EOF
******************************************************************************/
|
