mirror of
git://projects.qi-hardware.com/wernermisc.git
synced 2024-11-15 16:52:48 +02:00
57 lines
1.6 KiB
Diff
57 lines
1.6 KiB
Diff
This patch moves MIDI message detection from higher layers to the MIDI
|
|
interrupt handler. This way, MIDI receivers only need to wake up once
|
|
per complete message and not for every single byte.
|
|
|
|
The /dev/midi queue size is changed from 64 bytes to 32 messages
|
|
(typically 3 bytes each).
|
|
|
|
Index: rtems/c/src/lib/libbsp/lm32/shared/milkymist_midi/midi.c
|
|
===================================================================
|
|
--- rtems.orig/c/src/lib/libbsp/lm32/shared/milkymist_midi/midi.c 2011-12-01 19:45:37.000000000 -0300
|
|
+++ rtems/c/src/lib/libbsp/lm32/shared/milkymist_midi/midi.c 2011-12-02 16:05:30.000000000 -0300
|
|
@@ -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 @@
|
|
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 @@
|
|
|
|
sc = rtems_message_queue_create(
|
|
rtems_build_name('M', 'I', 'D', 'I'),
|
|
- 64,
|
|
- 1,
|
|
+ 32,
|
|
+ 3,
|
|
0,
|
|
&midi_q
|
|
);
|