extmod/modmachine: Add MICROPY_PY_MACHINE_SIGNAL configuration option.

Enabled by default.

Signed-off-by: Damien George <damien@micropython.org>

extmod/machine_signal.c

@@ -24,12 +24,11 @@
  * THE SOFTWARE.
  */
 
-#include "py/mpconfig.h"
-#if MICROPY_PY_MACHINE
-
 #include <string.h>
-
 #include "py/runtime.h"
+
+#if MICROPY_PY_MACHINE_SIGNAL
+
 #include "extmod/modmachine.h"
 #include "extmod/virtpin.h"
 
@@ -181,4 +180,4 @@ MP_DEFINE_CONST_OBJ_TYPE(
     locals_dict, &signal_locals_dict
     );
 
-#endif // MICROPY_PY_MACHINE
+#endif // MICROPY_PY_MACHINE_SIGNAL

extmod/modmachine.c

@@ -186,7 +186,9 @@ static const mp_rom_map_elem_t machine_module_globals_table[] = {
     #if MICROPY_PY_MACHINE_PIN_BASE
     { MP_ROM_QSTR(MP_QSTR_PinBase), MP_ROM_PTR(&machine_pinbase_type) },
     #endif
+    #if MICROPY_PY_MACHINE_SIGNAL
     { MP_ROM_QSTR(MP_QSTR_Signal), MP_ROM_PTR(&machine_signal_type) },
+    #endif
 
     // Classes for software bus protocols.
     #if MICROPY_PY_MACHINE_SOFTI2C

py/mpconfig.h

@@ -1702,6 +1702,11 @@ typedef double mp_float_t;
 #define MICROPY_PY_MACHINE_PULSE (0)
 #endif
 
+// Whether to provide the "machine.Signal" class
+#ifndef MICROPY_PY_MACHINE_SIGNAL
+#define MICROPY_PY_MACHINE_SIGNAL (MICROPY_PY_MACHINE)
+#endif
+
 #ifndef MICROPY_PY_MACHINE_I2C
 #define MICROPY_PY_MACHINE_I2C (0)
 #endif