Including SPI 3-wires class
Fork of X_NUCLEO_COMMON_SPI3W by
Diff: DevSPI/DevSPI.h
- Revision:
- 9:1f35e8bf427b
- Child:
- 10:da29b5403ca1
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/DevSPI/DevSPI.h Wed Oct 14 16:50:22 2015 +0200 @@ -0,0 +1,199 @@ +/** + ****************************************************************************** + * @file DevSPI.h + * @author AST / Software Platforms and Cloud + * @version V0.0.1 + * @date September 24th, 2015 + * @brief Header file for a special SPI class DevSPI which provides some + * helper function for on-board communication. + ****************************************************************************** + * @attention + * + * <h2><center>© COPYRIGHT(c) 2014 STMicroelectronics</center></h2> + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. 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. + * 3. Neither the name of STMicroelectronics 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. + * + ****************************************************************************** + */ + +/* Define to prevent from recursive inclusion --------------------------------*/ +#ifndef __DEV_SPI_H +#define __DEV_SPI_H + +/* Includes ------------------------------------------------------------------*/ +#include "mbed.h" + +/* Classes -------------------------------------------------------------------*/ +/** Helper class DevSPI providing functions for multi-register SPI communication + * common for a series of SPI devices. + */ +class DevSPI : public SPI +{ + public: + /* + * Create a DevSPI interface. + * @param mosi pin name of the MOSI pin of the SPI device to be used for communication. + * @param miso pin name of the MISO pin of the SPI device to be used for communication. + * @param sclk pin name of the SCLK pin of the SPI device to be used for communication. + */ + DevSPI(PinName mosi, PinName miso, PinName sclk) : SPI(mosi, miso, sclk) + { + bits = 9; + mode = 0; + frequency_hz = 1E6; + setup_done = false; + } + + /* + * Setup the spi. + * Typically: + * + 8 bit data; + * + high steady state clock; + * + second edge capture; + * + 1MHz clock rate. + * + * @param bits Number of bits per SPI frame (4 - 16) + * @param mode Clock polarity and phase mode (0 - 3) + * @param frequency_hz SCLK frequency in hz (default = 1MHz) + * + * @code + * mode | POL PHA + * -----+-------- + * 0 | 0 0 + * 1 | 0 1 + * 2 | 1 0 + * 3 | 1 1 + * @endcode + */ + void setup(int bits, int mode = 0, int frequency_hz = 1E6) + { + format(bits, mode); + frequency(frequency_hz); + setup_done = true; + } + + /** + * @brief Writes a buffer to the SPI peripheral device. + * @param[in] pBuffer pointer to the buffer of data to send. + * @param[in] ssel GPIO of the SSEL pin of the SPI device to be used for communication. + * @param[in] NumBytesToWrite number of bytes to write. + * @retval 0 if ok. + * @note When using the SPI in Interrupt-mode, remember to disable interrupts + * before calling this function and to enable them again after. + */ + int spi_write(uint8_t* pBuffer, DigitalOut ssel, uint16_t NumBytesToWrite) + { + /* Setup. */ + if (!setup_done) + { + ssel = 1; + setup(8, 3, 1E6); + setup_done = true; + } + + /* Select the chip. */ + ssel = 0; + + /* Write data. */ + for (int i = 0; i < NumBytesToWrite; i++) + write(pBuffer[i]); + + /* Unselect the chip. */ + ssel = 1; + + return 0; + } + + /** + * @brief Reads a buffer from the SPI peripheral device. + * @param[out] pBuffer pointer to the buffer to read data into. + * @param[in] ssel GPIO of the SSEL pin of the SPI device to be used for communication. + * @param[in] NumBytesToRead number of bytes to read. + * @retval 0 if ok. + * @note When using the SPI in Interrupt-mode, remember to disable interrupts + * before calling this function and to enable them again after. + */ + int spi_read(uint8_t* pBuffer, DigitalOut ssel, uint16_t NumBytesToRead) + { + /* Setup. */ + if (!setup_done) + { + ssel = 1; + setup(8, 3, 1E6); + setup_done = true; + } + + /* Select the chip. */ + ssel = 0; + + /* Read data. */ + for (int i = 0; i < NumBytesToRead; i++) + pBuffer[i] = write(0x00); + + /* Unselect the chip. */ + ssel = 1; + + return 0; + } + + /** + * @brief Reads and write a buffer from/to the SPI peripheral device at the same time. + * @param[out] pBufferToRead pointer to the buffer to read data into. + * @param[in] pBufferToWrite pointer to the buffer of data to send. + * @param[in] ssel GPIO of the SSEL pin of the SPI device to be used for communication. + * @param[in] NumBytes number of bytes to read and write. + * @retval 0 if ok. + * @note When using the SPI in Interrupt-mode, remember to disable interrupts + * before calling this function and to enable them again after. + */ + int spi_read_write(uint8_t* pBufferToRead, uint8_t* pBufferToWrite, DigitalOut ssel, uint16_t NumBytes) + { + /* Setup. */ + if (!setup_done) + { + ssel = 1; + setup(8, 3, 1E6); + setup_done = true; + } + + /* Select the chip. */ + ssel = 0; + + /* Read and write data at the same time. */ + for (int i = 0; i < NumBytes; i++) + pBufferToRead[i] = write(pBufferToWrite[i]); + + /* Unselect the chip. */ + ssel = 1; + + return 0; + } + + protected: + bool setup_done; + int bits; + int mode; + int frequency_hz; +}; + +#endif /* __DEV_SPI_H */