codal_port/microbit_pinmode: Make audio and speech use "audio" pin mode.

This distinguishes "music" and "audio" as separate modes as returned by
pin.get_mode(), making v2 more compatible with micro:bit v1.

Fixes issue #137.

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

Author: dpgeorge

src/codal_port/microbit_pinaudio.c

@@ -30,7 +30,7 @@
 // The currently selected pin output for the audio.
 STATIC const microbit_pin_obj_t *audio_routed_pin = NULL;
 
-void microbit_pin_audio_select(mp_const_obj_t select) {
+void microbit_pin_audio_select(mp_const_obj_t select, const microbit_pinmode_t *pinmode) {
     // Work out which pins are requested for the audio output.
     const microbit_pin_obj_t *pin_selected;
     if (select == mp_const_none) {
@@ -50,9 +50,12 @@ void microbit_pin_audio_select(mp_const_obj_t select) {
         if (audio_routed_pin == NULL) {
             microbit_hal_audio_select_pin(-1);
         } else {
-            microbit_obj_pin_acquire(audio_routed_pin, microbit_pin_mode_music);
+            microbit_obj_pin_acquire(audio_routed_pin, pinmode);
             microbit_hal_audio_select_pin(audio_routed_pin->name);
         }
+    } else if (audio_routed_pin != NULL) {
+        // Update the pin acquisition mode, to make sure pin.get_mode() reflects the current mode.
+        microbit_pin_set_mode(audio_routed_pin, pinmode);
     }
 }
 

src/codal_port/microbit_pinmode.c

@@ -39,15 +39,15 @@ const microbit_pinmode_t *microbit_pin_get_mode(const microbit_pin_obj_t *pin) {
     return &microbit_pinmodes[pinmode];
 }
 
-static void set_mode(uint32_t pin, const microbit_pinmode_t *mode) {
+void microbit_pin_set_mode(const microbit_pin_obj_t *pin, const microbit_pinmode_t *mode) {
     uint32_t index = mode - &microbit_pinmodes[0];
-    microbit_pinmode_indices[pin] = index;
+    microbit_pinmode_indices[pin->number] = index;
     return;
 }
 
 void microbit_obj_pin_free(const microbit_pin_obj_t *pin) {
     if (pin != NULL) {
-        set_mode(pin->number, microbit_pin_mode_unused);
+        microbit_pin_set_mode(pin, microbit_pin_mode_unused);
     }
 }
 
@@ -66,7 +66,7 @@ bool microbit_obj_pin_acquire(const microbit_pin_obj_t *pin, const microbit_pinm
 
     if (current_mode != new_mode) {
         current_mode->release(pin);
-        set_mode(pin->number, new_mode);
+        microbit_pin_set_mode(pin, new_mode);
         return true;
     } else {
         return false;
@@ -86,7 +86,7 @@ static void analog_release(const microbit_pin_obj_t *pin) {
     // TODO: pwm_release()
 }
 
-static void music_release(const microbit_pin_obj_t *pin) {
+static void audio_music_release(const microbit_pin_obj_t *pin) {
     if (microbit_audio_is_playing() || microbit_music_is_playing()) {
         pinmode_error(pin);
     } else {
@@ -101,8 +101,8 @@ const microbit_pinmode_t microbit_pinmodes[] = {
     [MODE_WRITE_DIGITAL] = { MP_QSTR_write_digital, noop },
     [MODE_DISPLAY]       = { MP_QSTR_display, pinmode_error },
     [MODE_BUTTON]        = { MP_QSTR_button, pinmode_error },
-    [MODE_MUSIC]         = { MP_QSTR_music, music_release },
-    [MODE_AUDIO_PLAY]    = { MP_QSTR_audio, noop },
+    [MODE_MUSIC]         = { MP_QSTR_music, audio_music_release },
+    [MODE_AUDIO_PLAY]    = { MP_QSTR_audio, audio_music_release },
     [MODE_TOUCH]         = { MP_QSTR_touch, noop },
     [MODE_I2C]           = { MP_QSTR_i2c, pinmode_error },
     [MODE_SPI]           = { MP_QSTR_spi, pinmode_error }

src/codal_port/modaudio.c

@@ -140,7 +140,7 @@ void microbit_audio_play_source(mp_obj_t src, mp_obj_t pin_select, bool wait, ui
         microbit_audio_stop();
     }
     audio_init(sample_rate);
-    microbit_pin_audio_select(pin_select);
+    microbit_pin_audio_select(pin_select, microbit_pin_mode_audio_play);
 
     const char *sound_expr_data = NULL;
     if (mp_obj_is_type(src, &microbit_sound_type)) {

src/codal_port/modmicrobit.h

@@ -220,11 +220,15 @@ bool microbit_obj_pin_can_be_acquired(const microbit_pin_obj_t *pin);
 // Not safe to call in an interrupt as it may raise if pin can't be acquired.
 bool microbit_obj_pin_acquire(const microbit_pin_obj_t *pin, const microbit_pinmode_t *mode);
 
+// Change the mode of a pin.  This does not check the existing mode, nor release any
+// resources, and should only be used if pin resources are managed by the caller.
+void microbit_pin_set_mode(const microbit_pin_obj_t *pin, const microbit_pinmode_t *mode);
+
 const microbit_pinmode_t *microbit_pin_get_mode(const microbit_pin_obj_t *pin);
 void pinmode_error(const microbit_pin_obj_t *pin);
 
 void microbit_pin_audio_speaker_enable(bool enable);
-void microbit_pin_audio_select(mp_const_obj_t select);
+void microbit_pin_audio_select(mp_const_obj_t select, const microbit_pinmode_t *pinmode);
 void microbit_pin_audio_free(void);
 
 MP_DECLARE_CONST_FUN_OBJ_0(microbit_reset_obj);

src/codal_port/modmusic.c

@@ -284,7 +284,7 @@ STATIC mp_obj_t microbit_music_stop(mp_uint_t n_args, const mp_obj_t *args) {
         pin = args[0];
     }
     // Raise exception if the pin we are trying to stop is not in a compatible mode.
-    microbit_pin_audio_select(pin);
+    microbit_pin_audio_select(pin, microbit_pin_mode_music);
 
     // Stop any ongoing background music
     music_data->async_state = ASYNC_MUSIC_STATE_IDLE;
@@ -326,7 +326,7 @@ STATIC mp_obj_t microbit_music_play(mp_uint_t n_args, const mp_obj_t *pos_args,
     music_data->async_state = ASYNC_MUSIC_STATE_IDLE;
 
     // get the pin to play on
-    microbit_pin_audio_select(args[1].u_obj);
+    microbit_pin_audio_select(args[1].u_obj, microbit_pin_mode_music);
 
     // start the tune running in the background
     music_data->async_wait_ticks = mp_hal_ticks_ms();
@@ -372,7 +372,7 @@ STATIC mp_obj_t microbit_music_pitch(mp_uint_t n_args, const mp_obj_t *pos_args,
     music_data->async_state = ASYNC_MUSIC_STATE_IDLE;
 
     // Update pin modes
-    microbit_pin_audio_select(args[2].u_obj);
+    microbit_pin_audio_select(args[2].u_obj, microbit_pin_mode_music);
 
     bool wait = args[3].u_bool;
     music_output_amplitude(MUSIC_OUTPUT_AMPLITUDE_ON);

src/codal_port/modspeech.c

@@ -421,7 +421,7 @@ STATIC mp_obj_t articulate(mp_obj_t phonemes, mp_uint_t n_args, const mp_obj_t *
 
     #if USE_DEDICATED_AUDIO_CHANNEL
     sam_output_reset(NULL);
-    microbit_pin_audio_select(args[7].u_obj);
+    microbit_pin_audio_select(args[7].u_obj, microbit_pin_mode_audio_play);
     microbit_hal_audio_speech_init(sample_rate);
     #else
     speech_iterator_t *src = make_speech_iter();