Diff: swspi.h

Revision:

0:8a4db0f083fc

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/swspi.h	Sun Jun 11 04:04:19 2017 +0000
@@ -0,0 +1,84 @@
+// Software (bit-banged) SPI Module supporting two CPHA modes and two
+// chip select signals.  Yields to allow use by different threads.
+//
+
+#ifndef sw_spi_h
+#define sw_spi_h
+
+#include "mbed.h"
+#include <stdint.h>
+
+// This is the bit in the SPI address that marks it as a write
+#define SPI_WRITE_MASK 0x80
+
+
+/////////////////////////////////////////////////////////////////////
+/// \class swspi swspi.h <swspi.h>
+/// \brief bit-banged SPI
+
+class swspi
+{
+public:
+    /// Constructor
+    /// \param[in] mosiPin pin number for MOSI
+    /// \param[in] misoPin pin number for MISO
+    /// \param[in] sckPin pin number for SCK
+    /// \param[in] ss1Pin pin number for Slave Select 1
+    /// \param[in] ss2Pin pin number for Slave Select 2
+    swspi(PinName mosiPin, PinName misoPin, PinName sckPin, PinName ss1Pin, PinName ss2Pin);
+
+    /// Initialise the Driver transport hardware and software.
+    /// Make sure the Driver is properly configured before calling init().
+    void           init();
+
+    /// Reads a single register from the SPI device
+    /// \param[in] reg Register number
+    /// \return The value of the register
+    uint8_t        spiRead(uint8_t reg, int cpha, int ss);
+
+    /// Writes a single byte to the SPI device
+    /// \param[in] reg Register number
+    /// \param[in] val The value to write
+    /// \return Some devices return a status byte during the first data transfer. This byte is returned.
+    ///  it may or may not be meaningfule depending on the the type of device being accessed.
+    uint8_t           spiWrite(uint8_t reg, uint8_t val, int cpha, int ss);
+
+    /// Reads a number of consecutive registers from the SPI device using burst read mode
+    /// \param[in] reg Register number of the first register
+    /// \param[in] dest Array to write the register values to. Must be at least len bytes
+    /// \param[in] len Number of bytes to read
+    /// \return Some devices return a status byte during the first data transfer. This byte is returned.
+    ///  it may or may not be meaningfule depending on the the type of device being accessed.
+    uint8_t           spiBurstRead(uint8_t reg, uint8_t* dest, uint8_t len, int cpha, int ss);
+
+    /// Write a number of consecutive registers using burst write mode
+    /// \param[in] reg Register number of the first register
+    /// \param[in] src Array of new register values to write. Must be at least len bytes
+    /// \param[in] len Number of bytes to write
+    /// \return Some devices return a status byte during the first data transfer. This byte is returned.
+    ///  it may or may not be meaningfule depending on the the type of device being accessed.
+    uint8_t           spiBurstWrite(uint8_t reg, const uint8_t* src, uint8_t len, int cpha, int ss);
+
+protected:
+
+    void _setSlaveSelect(int v);
+    uint8_t _transfer(uint8_t v);
+    
+    /// Pins
+    DigitalOut* mosiP;
+    DigitalIn* misoP;
+    DigitalOut* sckP;
+    DigitalOut* ss1P;
+    DigitalOut* ss2P;
+    
+    /// The current transfer data phase
+    int                 _cpha;
+    
+    /// The current transfer slave select
+    uint8_t             _ss;
+    
+    // Access control
+    Mutex               _spi_mutex;
+};
+
+#endif