libraries: SPI: handle multiple SPI instances

Create multiple SPI instances if the `spis` array contains plural elements.
Declare these as 'SPI1', 'SPI2', ..., from the second element of the array.
(The first element is already declared as 'SPI'.)

If `spis` is not defined but the DTS already defines `arduino-spi` and,
use it to define the first SPI instance.
The `arduion-spi` is usually defined with arduino_header in
boards definitions.

Signed-off-by: TOKITA Hiroshi <tokita.hiroshi@gmail.com>

libraries/SPI/SPI.cpp

@@ -121,5 +121,26 @@ void arduino::ZephyrSPI::begin() {}
 
 void arduino::ZephyrSPI::end() {}
 
-arduino::ZephyrSPI
-    SPI(DEVICE_DT_GET(DT_PHANDLE_BY_IDX(DT_PATH(zephyr_user), spis, 0)));
+#if DT_NODE_HAS_PROP(DT_PATH(zephyr_user), spis)
+#if (DT_PROP_LEN(DT_PATH(zephyr_user), spis) > 1)
+#define ARDUINO_SPI_DEFINED_0 1
+#define DECL_SPI_0(n, p, i)   arduino::ZephyrSPI SPI(DEVICE_DT_GET(DT_PHANDLE_BY_IDX(n, p, i)));
+#define DECL_SPI_N(n, p, i)   arduino::ZephyrSPI SPI##i(DEVICE_DT_GET(DT_PHANDLE_BY_IDX(n, p, i)));
+#define DECLARE_SPI_N(n, p, i)                                                                     \
+	COND_CODE_1(ARDUINO_SPI_DEFINED_##i, (DECL_SPI_0(n, p, i)), (DECL_SPI_N(n, p, i)))
+
+/* Declare SPI, SPI1, SPI2, ... */
+DT_FOREACH_PROP_ELEM(DT_PATH(zephyr_user), spis, DECLARE_SPI_N)
+
+#undef DECLARE_SPI_N
+#undef DECL_SPI_N
+#undef DECL_SPI_0
+#undef ARDUINO_SPI_DEFINED_0
+#else  // PROP_LEN(spis) > 1
+/* When PROP_LEN(spis) == 1, DT_FOREACH_PROP_ELEM work not correctly. */
+arduino::ZephyrSPI SPI(DEVICE_DT_GET(DT_PHANDLE_BY_IDX(DT_PATH(zephyr_user), spis, 0)));
+#endif // HAS_PORP(spis)
+/* If spis node is not defined, tries to use arduino_spi */
+#elif DT_NODE_EXISTS(DT_NODELABEL(arduino_spi))
+arduino::ZephyrSPI SPI(DEVICE_DT_GET(DT_NODELABEL(arduino_spi)));
+#endif

libraries/SPI/SPI.h

@@ -56,7 +56,24 @@ class ZephyrSPI : public HardwareSPI {
 
 } // namespace arduino
 
+#if DT_NODE_HAS_PROP(DT_PATH(zephyr_user), spis) && (DT_PROP_LEN(DT_PATH(zephyr_user), spis) > 1)
+#define ARDUINO_SPI_DEFINED_0 1
+#define DECL_EXTERN_SPI_0(i)  extern arduino::ZephyrSPI SPI
+#define DECL_EXTERN_SPI_N(i)  extern arduino::ZephyrSPI SPI##i
+#define DECLARE_EXTERN_SPI_N(n, p, i)                                                              \
+	COND_CODE_1(ARDUINO_SPI_DEFINED_##i, (DECL_EXTERN_SPI_0(i);), (DECL_EXTERN_SPI_N(i);))
+
+/* Declare SPI, SPI1, SPI2, ... */
+DT_FOREACH_PROP_ELEM(DT_PATH(zephyr_user), spis, DECLARE_EXTERN_SPI_N)
+
+#undef DECLARE_EXTERN_SPI_N
+#undef DECL_EXTERN_SPI_N
+#undef DECL_EXTERN_SPI_0
+#undef ARDUINO_SPI_DEFINED_0
+#else
 extern arduino::ZephyrSPI SPI;
+#endif
+
 /* Serial Peripheral Control Register */
 extern uint8_t SPCR;