SPI API platform implementation stubs

Marlin/src/HAL/HAL_DUE/spi_impl.cpp

@@ -0,0 +1,51 @@
+#ifdef ARDUINO_ARCH_SAM
+
+#include <stdint.h>
+
+namespace HAL {
+namespace SPI {
+
+bool initialise(uint8_t channel) {
+  return false;
+}
+
+bool enable_cs(uint8_t channel) {
+  return false;
+}
+
+void disable_cs(uint8_t channel) {
+
+}
+
+void set_frequency(uint8_t channel, uint32_t frequency) {
+
+}
+
+void read(uint8_t channel, uint8_t *buffer, uint32_t length) {
+
+}
+
+uint8_t read(uint8_t channel) {
+  return '\0';
+}
+
+void write(uint8_t channel, const uint8_t *buffer, uint32_t length) {
+
+}
+
+void write(uint8_t channel, uint8_t value) {
+
+}
+
+void transfer(uint8_t channel, const uint8_t *buffer_write, uint8_t *buffer_read, uint32_t length) {
+
+}
+
+uint8_t transfer(uint8_t channel, uint8_t value) {
+  return '\0';
+}
+
+} // namespace SPI
+} // namespace HAL
+
+#endif //#ifdef ARDUINO_ARCH_AVR