fix compiler warnings

src/rp2_common/hardware_pio/pio.c

diff --git a/src/rp2_common/hardware_pio/pio.c b/src/rp2_common/hardware_pio/pio.c
index 976d7e5..10698ea 100644
--- a/src/rp2_common/hardware_pio/pio.c
+++ b/src/rp2_common/hardware_pio/pio.c
@@ -413,11 +413,11 @@
             int offset_or_error = pio_add_program(pio, program);
             if (offset_or_error >= 0) {
                 *pio_out = pio;
-                *sm_out = sm_or_error;
-                *offset_out = offset_or_error;
+                *sm_out = (uint)sm_or_error;
+                *offset_out = (uint)offset_or_error;
                 return true;
             }
-            pio_sm_unclaim(pio, sm_or_error);
+            pio_sm_unclaim(pio, (uint)sm_or_error);
         }
     }
     return false;