drv_spi.cpp

00001 /*******************************************************************************
00002  Simple SPI Transfer function
00003 
00004   File Name:
00005     drv_spi.c
00006 
00007   Summary:
00008     Initializes SPI 1. Transfers data over SPI.
00009     Uses SPI FIFO to speed up transfer.
00010 
00011   Description:
00012     .
00013 
00014   Remarks:
00015     
00016  *******************************************************************************/
00017 
00018 // DOM-IGNORE-BEGIN
00019 /*******************************************************************************
00020 Copyright (c) 2016 Microchip Technology Inc. and its subsidiaries.  
00021 You may use this software and any derivatives exclusively with Microchip products. 
00022   
00023 THIS SOFTWARE IS SUPPLIED BY MICROCHIP "AS IS".  
00024 NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, APPLY TO THIS SOFTWARE, 
00025 INCLUDING ANY IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY, 
00026 AND FITNESS FOR A PARTICULAR PURPOSE, OR ITS INTERACTION WITH MICROCHIP PRODUCTS, 
00027 COMBINATION WITH ANY OTHER PRODUCTS, OR USE IN ANY APPLICATION. 
00028 
00029 IN NO EVENT WILL MICROCHIP BE LIABLE FOR ANY INDIRECT, SPECIAL, PUNITIVE, 
00030 INCIDENTAL OR CONSEQUENTIAL LOSS, DAMAGE, COST OR EXPENSE OF ANY KIND WHATSOEVER 
00031 RELATED TO THE SOFTWARE, HOWEVER CAUSED, EVEN IF MICROCHIP HAS BEEN ADVISED 
00032 OF THE POSSIBILITY OR THE DAMAGES ARE FORESEEABLE.  TO THE FULLEST EXTENT ALLOWED BY LAW, 
00033 MICROCHIP'S TOTAL LIABILITY ON ALL CLAIMS IN ANY WAY RELATED TO THIS SOFTWARE 
00034 WILL NOT EXCEED THE AMOUNT OF FEES, IF ANY, THAT YOU HAVE PAID DIRECTLY TO MICROCHIP FOR THIS SOFTWARE.
00035 
00036 MICROCHIP PROVIDES THIS SOFTWARE CONDITIONALLY UPON YOUR ACCEPTANCE OF THESE TERMS.
00037  *******************************************************************************/
00038 // DOM-IGNORE-END
00039 
00040 #include "mbed.h"
00041 #include <stdint.h>
00042 #include <stdbool.h>
00043 #include <stddef.h>
00044 #include <stdlib.h>
00045 #include "drv_spi.h"
00046 /*
00047 #include "peripheral/spi/plib_spi.h"        // SPI PLIB Header
00048 #include "system_config.h"
00049 #include "system_definitions.h"
00050 */
00051 
00052 DigitalOut cs0(p13);
00053 DigitalOut cs1(p13);
00054 SPI spi0(p5, p6, p7);
00055 SPI spi1(p5, p6, p7); 
00056 
00057 int8_t DRV_SPI_ChipSelectAssert(uint8_t spiSlaveDeviceIndex, bool assert)
00058 {
00059     int8_t error = 0;
00060 
00061     // Select Chip Select
00062     switch (spiSlaveDeviceIndex) {
00063         case DRV_CANFDSPI_INDEX_0:
00064             if (assert) cs0 = 0;
00065             else cs0 = 1;
00066             break;
00067         case DRV_CANFDSPI_INDEX_1:
00068             if (assert) cs1 = 0;
00069             else cs1 = 1;
00070             break;
00071         default:
00072             error = -1;
00073             break;
00074     }
00075 
00076     return error;
00077 }
00078 
00079 void DRV_SPI_Initialize()
00080 {
00081     spi0.format(8,0);               /* 8 bits data tfr, mode0 */
00082     spi0.frequency(1000000);        /* 1 Mhz */
00083     spi1.format(8,0);
00084     spi1.frequency(1000000);
00085 
00086     return;
00087 }
00088 
00089 int8_t DRV_SPI_TransferData(uint8_t spiSlaveDeviceIndex, uint8_t *SpiTxData, uint8_t *SpiRxData, uint16_t spiTransferSize)
00090 {
00091     int8_t error = 0;
00092     bool continueLoop;
00093     uint16_t txcounter = 0;
00094     uint16_t rxcounter = 0;
00095     uint8_t unitsTxed = 0;
00096     const uint8_t maxUnits = 16;
00097     int i;
00098 
00099     // Assert CS
00100     error = DRV_SPI_ChipSelectAssert(spiSlaveDeviceIndex, true);
00101     if (error != 0) return error;
00102     
00103     if (spiSlaveDeviceIndex == 0) {
00104         for (i=0; i<spiTransferSize; i++) {
00105             SpiRxData[i] = spi0.write(SpiTxData[i]); 
00106         }
00107     }
00108     else if (spiSlaveDeviceIndex == 1) {
00109         for (i=0; i<spiTransferSize; i++) {
00110             SpiRxData[i] = spi1.write(SpiTxData[i]); 
00111         }
00112     }
00113     
00114     // De-assert CS
00115     error = DRV_SPI_ChipSelectAssert(spiSlaveDeviceIndex, false);
00116 
00117     return error;
00118 }
00119