SPI: Add explicit pinmap support

drivers/SPI.h

@@ -131,6 +131,33 @@ public:
      */
     SPI(PinName mosi, PinName miso, PinName sclk, PinName ssel, use_gpio_ssel_t);
 
+    /** Create a SPI master connected to the specified pins.
+     *
+     *  @note This constructor passes the SSEL pin selection to the target HAL.
+     *  Not all targets support SSEL, so this cannot be relied on in portable code.
+     *  Portable code should use the alternative constructor that uses GPIO
+     *  for SSEL.
+     *
+     *  @note You can specify mosi or miso as NC if not used.
+     *
+     *  @param explicit_pinmap reference to strucure which holds static pinmap.
+     */
+    SPI(const spi_pinmap_t &explicit_pinmap);
+
+    /** Create a SPI master connected to the specified pins.
+     *
+     *  @note This constructor manipulates the SSEL pin as a GPIO output
+     *  using a DigitalOut object. This should work on any target, and permits
+     *  the use of select() and deselect() methods to keep the pin asserted
+     *  between transfers.
+     *
+     *  @note You can specify mosi or miso as NC if not used.
+     *
+     *  @param explicit_pinmap reference to strucure which holds static pinmap.
+     *  @param ssel SPI Chip Select pin.
+     */
+    SPI(const spi_pinmap_t &explicit_pinmap, PinName ssel);
+
     virtual ~SPI();
 
     /** Configure the data transmission format.
@@ -408,6 +435,12 @@ protected:
     char _write_fill;
     /* Select count to handle re-entrant selection */
     int8_t _select_count;
+    /* Static pinmap data */
+    const spi_pinmap_t *_explicit_pinmap;
+    /* SPI peripheral name */
+    SPIName _peripheral_name;
+    /* Pointer to spi init function */
+    void (*_init_func)(SPI*);
 
 private:
     void _do_construct();
@@ -425,6 +458,10 @@ private:
      */
     static spi_peripheral_s *_alloc();
 
+    static void _do_init(SPI *obj);
+    static void _do_init_direct(SPI *obj);
+
+
 #endif //!defined(DOXYGEN_ONLY)
 };
 

drivers/source/SPI.cpp

@@ -36,8 +36,17 @@ SPI::SPI(PinName mosi, PinName miso, PinName sclk, PinName ssel) :
     _miso(miso),
     _sclk(sclk),
     _hw_ssel(ssel),
-    _sw_ssel(NC)
+    _sw_ssel(NC),
+    _explicit_pinmap(NULL),
+    _init_func(_do_init)
 {
+    // Need backwards compatibility with HALs not providing API
+#ifdef DEVICE_SPI_COUNT
+    _peripheral_name = spi_get_peripheral_name(_mosi, _miso, _sclk);
+#else
+    _peripheral_name = GlobalSPI;
+#endif
+
     _do_construct();
 }
 
@@ -49,11 +58,62 @@ SPI::SPI(PinName mosi, PinName miso, PinName sclk, PinName ssel, use_gpio_ssel_t
     _miso(miso),
     _sclk(sclk),
     _hw_ssel(NC),
-    _sw_ssel(ssel, 1)
+    _sw_ssel(ssel, 1),
+    _explicit_pinmap(NULL),
+    _init_func(_do_init)
+{
+    // Need backwards compatibility with HALs not providing API
+#ifdef DEVICE_SPI_COUNT
+    _peripheral_name = spi_get_peripheral_name(_mosi, _miso, _sclk);
+#else
+    _peripheral_name = GlobalSPI;
+#endif
+    _do_construct();
+}
+
+SPI::SPI(const spi_pinmap_t &pinmap) :
+#if DEVICE_SPI_ASYNCH
+    _irq(this),
+#endif
+    _mosi(pinmap.mosi_pin),
+    _miso(pinmap.miso_pin),
+    _sclk(pinmap.sclk_pin),
+    _hw_ssel(pinmap.ssel_pin),
+    _sw_ssel(NC),
+    _explicit_pinmap(&pinmap),
+    _peripheral_name((SPIName)pinmap.peripheral),
+    _init_func(_do_init_direct)
+
 {
     _do_construct();
 }
 
+SPI::SPI(const spi_pinmap_t &pinmap, PinName ssel) :
+#if DEVICE_SPI_ASYNCH
+    _irq(this),
+#endif
+    _mosi(pinmap.mosi_pin),
+    _miso(pinmap.miso_pin),
+    _sclk(pinmap.sclk_pin),
+    _hw_ssel(NC),
+    _sw_ssel(ssel, 1),
+    _explicit_pinmap(&pinmap),
+    _peripheral_name((SPIName)pinmap.peripheral),
+    _init_func(_do_init_direct)
+{
+    _do_construct();
+}
+
+void SPI::_do_init(SPI *obj)
+{
+    spi_init(&obj->_peripheral->spi, obj->_mosi, obj->_miso, obj->_sclk, obj->_hw_ssel);
+}
+
+void SPI::_do_init_direct(SPI *obj)
+{
+    spi_init_direct(&obj->_peripheral->spi, obj->_explicit_pinmap);
+}
+
 void SPI::_do_construct()
 {
     // No lock needed in the constructor
@@ -67,20 +127,13 @@ void SPI::_do_construct()
     _hz = 1000000;
     _write_fill = SPI_FILL_CHAR;
 
-    // Need backwards compatibility with HALs not providing API
-#ifdef DEVICE_SPI_COUNT
-    SPIName name = spi_get_peripheral_name(_mosi, _miso, _sclk);
-#else
-    SPIName name = GlobalSPI;
-#endif
-
     core_util_critical_section_enter();
     // lookup in a critical section if we already have it else initialize it
 
-    _peripheral = SPI::_lookup(name);
+    _peripheral = SPI::_lookup(_peripheral_name);
     if (!_peripheral) {
         _peripheral = SPI::_alloc();
-        _peripheral->name = name;
+        _peripheral->name = _peripheral_name;
     }
     core_util_critical_section_exit();
 
@@ -158,7 +211,7 @@ void SPI::frequency(int hz)
 void SPI::_acquire()
 {
     if (_peripheral->owner != this) {
-        spi_init(&_peripheral->spi, _mosi, _miso, _sclk, _hw_ssel);
+        _init_func(this);
         spi_format(&_peripheral->spi, _bits, _mode, 0);
         spi_frequency(&_peripheral->spi, _hz);
         _peripheral->owner = this;