/* * Author: Brendan Le Foll * Copyright (c) 2014 Intel Corporation. * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #pragma once #include "spi.h" #include "types.hpp" #include namespace mraa { /** * MRAA SPI Modes */ typedef enum { SPI_MODE0 = 0, /**< CPOL = 0, CPHA = 0, Clock idle low, data is clocked in on rising edge, output data (change) on falling edge */ SPI_MODE1 = 1, /**< CPOL = 0, CPHA = 1, Clock idle low, data is clocked in on falling edge, output data (change) on rising edge */ SPI_MODE2 = 2, /**< CPOL = 1, CPHA = 0, Clock idle low, data is clocked in on falling edge, output data (change) on rising edge */ SPI_MODE3 = 3, /**< CPOL = 1, CPHA = 1, Clock idle low, data is clocked in on rising, edge output data (change) on falling edge */ } Spi_Mode; /** * @brief API to Serial Peripheral Interface * * This file defines the SPI interface for libmraa * * @snippet Spi-pot.cpp Interesting */ class Spi { public: /** * Initialise SPI object using the board mapping to set muxes * * @param bus to use, as listed in the platform definition, normally 0 */ Spi(int bus) { m_spi = mraa_spi_init(bus); if (m_spi == NULL) { throw std::invalid_argument("Error initialising SPI bus"); } } /** * Closes spi bus */ ~Spi() { mraa_spi_stop(m_spi); } /** * Set the SPI device mode. see spidev0-3 * * @param mode the mode. See Linux spidev doc * @return Result of operation */ Result mode(Spi_Mode mode) { return (Result) mraa_spi_mode(m_spi, (mraa_spi_mode_t) mode); } /** * Set the SPI device operating clock frequency * * @param hz the frequency to set in hz * @return Result of operation */ Result frequency(int hz) { return (Result) mraa_spi_frequency(m_spi, hz); } /** * Write single byte to the SPI device * * @param data the byte to send * @return data received on the miso line or -1 in case of error */ int writeByte(uint8_t data) { return mraa_spi_write(m_spi, (uint8_t) data); } /** * Write single byte to the SPI device * * @param data the byte to send * @return data received on the miso line */ uint16_t write_word(uint16_t data) { return mraa_spi_write_word(m_spi, (uint16_t) data); } /** * Write buffer of bytes to SPI device The pointer return has to be * free'd by the caller. It will return a NULL pointer in cases of * error * * @param txBuf buffer to send * @param length size of buffer to send * @return uint8_t* data received on the miso line. Same length as passed in */ uint8_t* write(uint8_t* txBuf, int length) { return mraa_spi_write_buf(m_spi, txBuf, length); } #ifndef SWIG /** * Write buffer of bytes to SPI device The pointer return has to be * free'd by the caller. It will return a NULL pointer in cases of * error * * @param txBuf buffer to send * @param length size of buffer (in bytes) to send * @return uint8_t* data received on the miso line. Same length as passed in */ uint16_t* write_word(uint16_t* txBuf, int length) { return mraa_spi_write_buf_word(m_spi, txBuf, length); } #endif #ifndef SWIG /** * Transfer data to and from SPI device Receive pointer may be null if * return data is not needed. * * @param txBuf buffer to send * @param rxBuf buffer to optionally receive data from spi device * @param length size of buffer to send * @return Result of operation */ Result transfer(uint8_t* txBuf, uint8_t* rxBuf, int length) { return (Result) mraa_spi_transfer_buf(m_spi, txBuf, rxBuf, length); } /** * Transfer data to and from SPI device Receive pointer may be null if * return data is not needed. * * @param txBuf buffer to send * @param rxBuf buffer to optionally receive data from spi device * @param length size of buffer to send * @return Result of operation */ Result transfer_word(uint16_t* txBuf, uint16_t* rxBuf, int length) { return (Result) mraa_spi_transfer_buf_word(m_spi, txBuf, rxBuf, length); } #endif /** * Change the SPI lsb mode * * @param lsb Use least significant bit transmission - 0 for msbi * @return Result of operation */ Result lsbmode(bool lsb) { return (Result) mraa_spi_lsbmode(m_spi, (mraa_boolean_t) lsb); } /** * Set bits per mode on transaction, default is 8 * * @param bits bits per word * @return Result of operation */ Result bitPerWord(unsigned int bits) { return (Result) mraa_spi_bit_per_word(m_spi, bits); } private: mraa_spi_context m_spi; }; }