diff options
Diffstat (limited to 'c/src/lib/libbsp/lm32/shared/milkymist_midi')
-rw-r--r-- | c/src/lib/libbsp/lm32/shared/milkymist_midi/midi.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/c/src/lib/libbsp/lm32/shared/milkymist_midi/midi.c b/c/src/lib/libbsp/lm32/shared/milkymist_midi/midi.c index ad5c4342d8..ce1a2f50e1 100644 --- a/c/src/lib/libbsp/lm32/shared/milkymist_midi/midi.c +++ b/c/src/lib/libbsp/lm32/shared/milkymist_midi/midi.c @@ -26,6 +26,8 @@ #define DEVICE_NAME "/dev/midi" static rtems_id midi_q; +static unsigned char *midi_p = NULL; +static unsigned char midi_msg[3]; static rtems_isr interrupt_handler(rtems_vector_number n) { @@ -34,7 +36,23 @@ static rtems_isr interrupt_handler(rtems_vector_number n) while (MM_READ(MM_MIDI_STAT) & MIDI_STAT_RX_EVT) { msg = MM_READ(MM_MIDI_RXTX); MM_WRITE(MM_MIDI_STAT, MIDI_STAT_RX_EVT); - rtems_message_queue_send(midi_q, &msg, 1); + + if ((msg & 0xf8) == 0xf8) + continue; /* ignore system real-time */ + + if (msg & 0x80) + midi_p = midi_msg; /* status byte */ + + if (!midi_p) + continue; /* ignore extra or unsynchronized data */ + + *midi_p++ = msg; + + if (midi_p == midi_msg+3) { + /* received a complete MIDI message */ + rtems_message_queue_send(midi_q, midi_msg, 3); + midi_p = NULL; + } } lm32_interrupt_ack(1 << MM_IRQ_MIDI); } @@ -53,8 +71,8 @@ rtems_device_driver midi_initialize( sc = rtems_message_queue_create( rtems_build_name('M', 'I', 'D', 'I'), - 64, - 1, + 32, + 3, 0, &midi_q ); |