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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 "ecspi.h"
/*******************************************************************************
* Code
******************************************************************************/
/*******************************************************************************
* eCSPI Initialization and Configuration functions
******************************************************************************/
/*FUNCTION**********************************************************************
*
* Function Name : ECSPI_Init
* Description : Initializes the eCSPI module according to the specified
* parameters in the initConfig.
*
*END**************************************************************************/
void ECSPI_Init(ECSPI_Type* base, const ecspi_init_config_t* initConfig)
{
/* Disable eCSPI module */
ECSPI_CONREG_REG(base) = 0;
/* Enable the eCSPI module before write to other registers */
ECSPI_Enable(base);
/* eCSPI CONREG Configuration */
ECSPI_CONREG_REG(base) |= ECSPI_CONREG_BURST_LENGTH(initConfig->burstLength) |
ECSPI_CONREG_CHANNEL_SELECT(initConfig->channelSelect);
ECSPI_CONREG_REG(base) |= initConfig->ecspiAutoStart ? ECSPI_CONREG_SMC_MASK : 0;
/* eCSPI CONFIGREG Configuration */
ECSPI_CONFIGREG_REG(base) = ECSPI_CONFIGREG_SCLK_PHA(((initConfig->clockPhase) & 1) << (initConfig->channelSelect)) |
ECSPI_CONFIGREG_SCLK_POL(((initConfig->clockPolarity) & 1) << (initConfig->channelSelect));
/* Master or Slave mode Configuration */
if(initConfig->mode == ecspiMasterMode)
{
/* Set baud rate in bits per second */
ECSPI_CONREG_REG(base) |= ECSPI_CONREG_CHANNEL_MODE(1 << (initConfig->channelSelect));
ECSPI_SetBaudRate(base, initConfig->clockRate, initConfig->baudRate);
}
else
ECSPI_CONREG_REG(base) &= ~ECSPI_CONREG_CHANNEL_MODE(1 << (initConfig->channelSelect));
}
/*FUNCTION**********************************************************************
*
* Function Name : ECSPI_SetSampClockSource
* Description : Configure the clock source for the sample period counter.
*
*END**************************************************************************/
void ECSPI_SetSampClockSource(ECSPI_Type* base, uint32_t source)
{
/* Select the clock source */
if(source == ecspiSclk)
ECSPI_PERIODREG_REG(base) &= ~ECSPI_PERIODREG_CSRC_MASK;
else
ECSPI_PERIODREG_REG(base) |= ECSPI_PERIODREG_CSRC_MASK;
}
/*FUNCTION**********************************************************************
*
* Function Name : ECSPI_SetBaudRate
* Description : Calculated the eCSPI baud rate in bits per second.
*
*END**************************************************************************/
uint32_t ECSPI_SetBaudRate(ECSPI_Type* base, uint32_t sourceClockInHz, uint32_t bitsPerSec)
{
uint32_t div, pre_div;
uint32_t post_baud; /* baud rate after post divider */
uint32_t pre_baud; /* baud rate before pre divider */
if(sourceClockInHz <= bitsPerSec)
{
ECSPI_CONREG_REG(base) &= ~ECSPI_CONREG_PRE_DIVIDER_MASK;
ECSPI_CONREG_REG(base) &= ~ECSPI_CONREG_POST_DIVIDER_MASK;
return sourceClockInHz;
}
div = sourceClockInHz / bitsPerSec;
if(div < 16) /* pre_divider is enough */
{
if((sourceClockInHz - bitsPerSec * div) < ((bitsPerSec * (div + 1)) - sourceClockInHz))
pre_div = div - 1; /* pre_divider value is one less than the real divider */
else
pre_div = div;
ECSPI_CONREG_REG(base) = (ECSPI_CONREG_REG(base) & (~ECSPI_CONREG_PRE_DIVIDER_MASK)) |
ECSPI_CONREG_PRE_DIVIDER(pre_div);
ECSPI_CONREG_REG(base) = (ECSPI_CONREG_REG(base) & (~ECSPI_CONREG_POST_DIVIDER_MASK)) |
ECSPI_CONREG_POST_DIVIDER(0);
return sourceClockInHz / (pre_div + 1);
}
pre_baud = bitsPerSec * 16;
for(div = 1; div < 16; div++)
{
post_baud = sourceClockInHz >> div;
if(post_baud < pre_baud)
break;
}
if(div == 16) /* divider is not enough, set the biggest ones */
{
ECSPI_CONREG_REG(base) |= ECSPI_CONREG_PRE_DIVIDER(15);
ECSPI_CONREG_REG(base) |= ECSPI_CONREG_POST_DIVIDER(15);
return post_baud / 16;
}
/* find the closed one */
if((post_baud - bitsPerSec * (post_baud / bitsPerSec)) < ((bitsPerSec * ((post_baud / bitsPerSec) + 1)) - post_baud))
pre_div = post_baud / bitsPerSec - 1;
else
pre_div = post_baud / bitsPerSec;
ECSPI_CONREG_REG(base) = (ECSPI_CONREG_REG(base) & (~ECSPI_CONREG_PRE_DIVIDER_MASK)) |
ECSPI_CONREG_PRE_DIVIDER(pre_div);
ECSPI_CONREG_REG(base) = (ECSPI_CONREG_REG(base) & (~ECSPI_CONREG_POST_DIVIDER_MASK)) |
ECSPI_CONREG_POST_DIVIDER(div);
return post_baud / (pre_div + 1);
}
/*******************************************************************************
* DMA management functions
******************************************************************************/
/*FUNCTION**********************************************************************
*
* Function Name : ECSPI_SetDMACmd
* Description : Enable or disable the specified DMA Source.
*
*END**************************************************************************/
void ECSPI_SetDMACmd(ECSPI_Type* base, uint32_t source, bool enable)
{
/* Configure the DAM source */
if(enable)
ECSPI_DMAREG_REG(base) |= ((uint32_t)(1 << source));
else
ECSPI_DMAREG_REG(base) &= ~((uint32_t)(1 << source));
}
/*FUNCTION**********************************************************************
*
* Function Name : ECSPI_SetFIFOThreshold
* Description : Set the RXFIFO or TXFIFO threshold.
*
*END**************************************************************************/
void ECSPI_SetFIFOThreshold(ECSPI_Type* base, uint32_t fifo, uint32_t threshold)
{
/* configure the RXFIFO and TXFIFO threshold that can triggers a DMA/INT request */
if(fifo == ecspiTxfifoThreshold)
ECSPI_DMAREG_REG(base) = (ECSPI_DMAREG_REG(base) & (~ECSPI_DMAREG_TX_THRESHOLD_MASK)) |
ECSPI_DMAREG_TX_THRESHOLD(threshold);
else
ECSPI_DMAREG_REG(base) = (ECSPI_DMAREG_REG(base) & (~ECSPI_DMAREG_RX_THRESHOLD_MASK)) |
ECSPI_DMAREG_RX_THRESHOLD(threshold);
}
/*******************************************************************************
* Interrupts and flags management functions
******************************************************************************/
/*FUNCTION**********************************************************************
*
* Function Name : ECSPI_SetIntCmd
* Description : Enable or disable eCSPI interrupts.
*
*END**************************************************************************/
void ECSPI_SetIntCmd(ECSPI_Type* base, uint32_t flags, bool enable)
{
/* Configure the Interrupt source */
if(enable)
ECSPI_INTREG_REG(base) |= flags;
else
ECSPI_INTREG_REG(base) &= ~flags;
}
/*******************************************************************************
* EOF
******************************************************************************/
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