spi_master.cpp

00001 /*
00002 
00003 Copyright (c) 2012-2014 RedBearLab
00004 
00005 Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
00006 and associated documentation files (the "Software"), to deal in the Software without restriction, 
00007 including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, 
00008 and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, 
00009 subject to the following conditions:
00010 The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
00011 
00012 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
00013 INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR 
00014 PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE 
00015 FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
00016 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00017 
00018 */
00019 
00020 #include "spi_master.h"
00021 
00022 /**********************************************************************
00023 name :
00024 function : 
00025 **********************************************************************/
00026 SPIClass::SPIClass(NRF_SPI_Type *_spi) : spi(_spi)
00027 {
00028     //do nothing
00029 }
00030 
00031 /**********************************************************************
00032 name :
00033 function : 
00034 **********************************************************************/
00035 void SPIClass::setCPOL( bool active_low)
00036 {
00037     if(active_low)
00038     {
00039         spi->CONFIG |= (SPI_CONFIG_CPOL_ActiveLow << SPI_CONFIG_CPOL_Pos);
00040     }
00041     else
00042     {
00043         spi->CONFIG |= (SPI_CONFIG_CPOL_ActiveHigh << SPI_CONFIG_CPOL_Pos);
00044     }
00045 }
00046 
00047 /**********************************************************************
00048 name :
00049 function : 
00050 **********************************************************************/
00051 void SPIClass::setCPHA( bool trailing)
00052 {
00053     if(trailing)
00054     {
00055         spi->CONFIG |= (SPI_CONFIG_CPHA_Trailing << SPI_CONFIG_CPHA_Pos);
00056     }
00057     else
00058     {
00059         spi->CONFIG |= (SPI_CONFIG_CPHA_Leading << SPI_CONFIG_CPHA_Pos);
00060     }
00061 
00062 }
00063 
00064 /**********************************************************************
00065 name :
00066 function : MSBFIRST, LSBFIRST
00067 **********************************************************************/
00068 void SPIClass::setBitORDER( BitOrder  bit)
00069 {
00070     if(bit == MSBFIRST)
00071     {
00072         spi->CONFIG |= (SPI_CONFIG_ORDER_MsbFirst << SPI_CONFIG_ORDER_Pos);
00073     }
00074     else
00075     {
00076         spi->CONFIG |= (SPI_CONFIG_ORDER_LsbFirst << SPI_CONFIG_ORDER_Pos);
00077     }
00078 }
00079 
00080 /**********************************************************************
00081 name :
00082 function : 
00083 **********************************************************************/
00084 void SPIClass::setFrequency(uint8_t speed)
00085 {
00086     if (speed == 0)
00087     {
00088         spi->FREQUENCY = SPI_FREQUENCY_125K;
00089     }
00090     else if (speed == 1)
00091     {
00092         spi->FREQUENCY = SPI_FREQUENCY_250K;
00093     }
00094     else if (speed == 2)
00095     {
00096         spi->FREQUENCY = SPI_FREQUENCY_500K;
00097     }
00098     else if (speed == 3)
00099     {
00100         spi->FREQUENCY = SPI_FREQUENCY_1M;
00101     }
00102     else if (speed == 4)
00103     {
00104         spi->FREQUENCY = SPI_FREQUENCY_2M;
00105     }
00106     else if (speed == 5)
00107     {
00108         spi->FREQUENCY = SPI_FREQUENCY_4M;
00109     }
00110     else if (speed == 6)
00111     {
00112         spi->FREQUENCY = SPI_FREQUENCY_8M;
00113     }
00114     else
00115     {
00116         spi->FREQUENCY = SPI_FREQUENCY_4M;
00117     }   
00118 }
00119 
00120 /**********************************************************************
00121 name :
00122 function : 
00123 **********************************************************************/
00124 void SPIClass::setSPIMode( uint8_t mode )
00125 {
00126     if (SPI_MODE0 == mode)
00127     {
00128         setCPOL(0);
00129         setCPHA(0);     
00130     }
00131     else if (mode == SPI_MODE1)
00132     {
00133         setCPOL(0);
00134         setCPHA(1);
00135     }
00136     else if (mode == SPI_MODE2)
00137     {
00138         setCPOL(1);
00139         setCPHA(0);
00140     }
00141     else if (mode == SPI_MODE3)
00142     {
00143         setCPOL(1);
00144         setCPHA(1);
00145     }
00146     else
00147     {
00148         setCPOL(0);
00149         setCPHA(0);         
00150     }
00151 }
00152 
00153 /**********************************************************************
00154 name :
00155 function : 
00156 **********************************************************************/
00157 void SPIClass::begin(uint32_t sck, uint32_t mosi, uint32_t miso)
00158 {
00159 
00160         SCK_Pin = sck;
00161         MOSI_Pin = mosi;
00162         MISO_Pin = miso;
00163         
00164         NRF_GPIO->PIN_CNF[SCK_Pin] = (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos)
00165                                         | (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos)
00166                                         | (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos)
00167                                         | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos)
00168                                         | (GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos);    
00169                                         
00170         NRF_GPIO->PIN_CNF[MOSI_Pin] = (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos)
00171                                         | (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos)
00172                                         | (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos)
00173                                         | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos)
00174                                         | (GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos);
00175                                         
00176         NRF_GPIO->PIN_CNF[MISO_Pin] = (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos)
00177                                         | (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos)
00178                                         | (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos)
00179                                         | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos)
00180                                         | (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos);                                     
00181         spi->PSELSCK  = SCK_Pin;
00182         spi->PSELMOSI = MOSI_Pin;
00183         spi->PSELMISO = MISO_Pin;       
00184         
00185         setFrequency(SPI_1M);
00186         setSPIMode(SPI_MODE3);
00187         setBitORDER(MSBFIRST);
00188         
00189         spi->EVENTS_READY = 0;
00190         spi->ENABLE = (SPI_ENABLE_ENABLE_Enabled << SPI_ENABLE_ENABLE_Pos);
00191     
00192 }
00193 
00194 /**********************************************************************
00195 name :
00196 function : 
00197 **********************************************************************/
00198 void SPIClass::begin()
00199 {
00200     begin(SCK, MOSI, MISO);
00201 }
00202 
00203 /**********************************************************************
00204 name :
00205 function : 
00206 **********************************************************************/
00207 uint8_t SPIClass::transfer(uint8_t data)
00208 {
00209     while( spi->EVENTS_READY != 0U );
00210     
00211     spi->TXD = (uint32_t)data;
00212     
00213     while(spi->EVENTS_READY == 0);
00214     
00215     data = (uint8_t)spi->RXD;
00216     
00217     spi->EVENTS_READY = 0;
00218     
00219     return data;
00220 }
00221 
00222 /**********************************************************************
00223 name :
00224 function : 
00225 **********************************************************************/
00226 void SPIClass::endTransfer()
00227 {
00228     spi->ENABLE = (SPI_ENABLE_ENABLE_Disabled << SPI_ENABLE_ENABLE_Pos);
00229 }
00230 
00231 /**********************************************************************
00232 name :
00233 function : 
00234 **********************************************************************/
00235 
00236 //SPIClass SPI(NRF_SPI1);