2 files changed, 9 insertions, 0 deletions
diff --git a/shared-bindings/busio/SPI.c b/shared-bindings/busio/SPI.c
index 22f001d2d..793ab4f67 100644
--- a/shared-bindings/busio/SPI.c
+++ b/shared-bindings/busio/SPI.c
@@ -418,3 +418,10 @@ const mp_obj_type_t busio_spi_type = {
    .make_new = busio_spi_make_new,
    .locals_dict = (mp_obj_dict_t*)&busio_spi_locals_dict,
 };
+
+busio_spi_obj_t *validate_obj_is_spi_bus(mp_obj_t obj) {
+    if (!MP_OBJ_IS_TYPE(obj, &busio_spi_type)) {
+        mp_raise_TypeError_varg(translate("Expected a %q"), busio_spi_type.name);
+    }
+    return MP_OBJ_TO_PTR(obj);
+}
diff --git a/shared-bindings/busio/SPI.h b/shared-bindings/busio/SPI.h
index b7b0715d1..aa7d715b9 100644
--- a/shared-bindings/busio/SPI.h
+++ b/shared-bindings/busio/SPI.h
@@ -70,4 +70,6 @@ uint8_t common_hal_busio_spi_get_polarity(busio_spi_obj_t* self);
 // This is used by the supervisor to claim SPI devices indefinitely.
 extern void common_hal_busio_spi_never_reset(busio_spi_obj_t *self);
 
+extern busio_spi_obj_t *validate_obj_is_spi_bus(mp_obj_t obj_in);
+
 #endif // MICROPY_INCLUDED_SHARED_BINDINGS_BUSIO_SPI_H