codal_port/microbit_pinaudio: Only allow one pin for audio selection.

The audio, music and speech modules can now only take either None ore a
single pin object to specify the output for the audio.  Note that this is
in addition to the speaker output which is now a completely independent
audio entity, and to which audio will always be directed (speaker output
can be disabled via speaker.off()).

Signed-off-by: Damien George <[email protected]>

Author: dpgeorge

src/codal_port/microbit_pin.c

@@ -264,7 +264,7 @@ const mp_obj_type_t microbit_touch_only_pin_type = {
     .locals_dict = (mp_obj_dict_t *)&microbit_touch_only_pin_locals_dict,
 };
 
-const microbit_pin_obj_t *microbit_obj_get_pin(mp_obj_t o) {
+const microbit_pin_obj_t *microbit_obj_get_pin(mp_const_obj_t o) {
     const mp_obj_type_t *type = mp_obj_get_type(o);
     if (type == &microbit_touch_pin_type || type == &microbit_ad_pin_type || type == &microbit_dig_pin_type) {
         return (microbit_pin_obj_t*)o;

src/codal_port/microbit_pinaudio.c

@@ -27,74 +27,17 @@
 #include "microbithal.h"
 #include "modmicrobit.h"
 
-const mp_obj_tuple_t microbit_pin_default_audio_obj = {
-    { &mp_type_tuple },
-    2,
-    {
-        (mp_obj_t)MP_ROM_PTR(&microbit_p0_obj),
-        (mp_obj_t)MP_ROM_PTR(&microbit_pin_speaker_obj),
-    }
-};
-
-// Whether the speaker is enabled or not.  If true, this overrides any selection
-// of the speaker to act as though it was not selected.
-STATIC bool audio_speaker_enabled = true;
-
-// The currently selected pin and/or speaker output for the audio.
+// The currently selected pin output for the audio.
 STATIC const microbit_pin_obj_t *audio_routed_pin = NULL;
-STATIC bool audio_routed_speaker = false;
-
-STATIC void microbit_pin_audio_get_pins(mp_const_obj_t select, const microbit_pin_obj_t **pin_selected, bool *speaker_selected) {
-    // Convert the "select" object into an array of items (which should be pins).
-    size_t len;
-    mp_obj_t *items;
-    if (mp_obj_is_type(select, &mp_type_tuple)) {
-        mp_obj_get_array((mp_obj_t)select, &len, &items);
-        if (len > 2) {
-            mp_raise_ValueError(MP_ERROR_TEXT("maximum of 2 pins allowed"));
-        }
-    } else {
-        len = 1;
-        items = (mp_obj_t *)&select;
-    }
-
-    // Work out which pins are selected for the audio output.
-    *pin_selected = NULL;
-    *speaker_selected = false;
-    if (len == 1 || len == 2) {
-        if (items[0] == &microbit_pin_speaker_obj) {
-            *speaker_selected = true;
-        } else {
-            *pin_selected = microbit_obj_get_pin(items[0]);
-        }
-        if (len == 2) {
-            if (items[1] == &microbit_pin_speaker_obj) {
-                if (*speaker_selected) {
-                    mp_raise_ValueError(MP_ERROR_TEXT("speaker selected twice"));
-                }
-                *speaker_selected = true;
-            } else {
-                if (*pin_selected != NULL) {
-                    mp_raise_ValueError(MP_ERROR_TEXT("can only select one non-speaker pin"));
-                }
-                *pin_selected = microbit_obj_get_pin(items[1]);
-            }
-        }
-    }
-
-    // Apply global override to enable/disable speaker.
-    *speaker_selected = *speaker_selected && audio_speaker_enabled;
-}
-
-void microbit_pin_audio_speaker_enable(bool enable) {
-    audio_speaker_enabled = enable;
-}
 
 void microbit_pin_audio_select(mp_const_obj_t select) {
-    // Work out which pins are selected.
+    // Work out which pins are requested for the audio output.
     const microbit_pin_obj_t *pin_selected;
-    bool speaker_selected;
-    microbit_pin_audio_get_pins(select, &pin_selected, &speaker_selected);
+    if (select == mp_const_none) {
+        pin_selected = NULL;
+    } else {
+        pin_selected = microbit_obj_get_pin((mp_obj_t)select);
+    }
 
     // Change the pin if needed.
     if (pin_selected != audio_routed_pin) {
@@ -109,12 +52,6 @@ void microbit_pin_audio_select(mp_const_obj_t select) {
             microbit_hal_audio_select_pin(audio_routed_pin->name);
         }
     }
-
-    // Change the speaker mode if needed.
-    if (speaker_selected != audio_routed_speaker) {
-        audio_routed_speaker = speaker_selected;
-        microbit_hal_audio_select_speaker(audio_routed_speaker);
-    }
 }
 
 void microbit_pin_audio_free(void) {

src/codal_port/modmicrobit.h

@@ -55,6 +55,8 @@
 #define microbit_pin_mode_i2c           (&microbit_pinmodes[MODE_I2C])
 #define microbit_pin_mode_spi           (&microbit_pinmodes[MODE_SPI])
 
+#define microbit_pin_default_audio_obj (microbit_p0_obj)
+
 typedef struct _microbit_pin_obj_t {
     mp_obj_base_t base;
     uint8_t number; // The pin number on microbit board
@@ -188,10 +190,7 @@ extern const struct _microbit_microphone_obj_t microbit_microphone_obj;
 extern const struct _microbit_button_obj_t microbit_button_a_obj;
 extern const struct _microbit_button_obj_t microbit_button_b_obj;
 
-//extern uint16_t microbit_volume_global;
-extern const mp_obj_tuple_t microbit_pin_default_audio_obj;
-
-const microbit_pin_obj_t *microbit_obj_get_pin(mp_obj_t o);
+const microbit_pin_obj_t *microbit_obj_get_pin(mp_const_obj_t o);
 
 // Release pin for use by other modes. Safe to call in an interrupt.
 // If pin is NULL or pin already unused, then this is a no-op