--- /dev/null
+/*
+ * sound/oss/pas2_midi.c
+ *
+ * The low level driver for the PAS Midi Interface.
+ */
+/*
+ * Copyright (C) by Hannu Savolainen 1993-1997
+ *
+ * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
+ * Version 2 (June 1991). See the "COPYING" file distributed with this software
+ * for more info.
+ *
+ * Bartlomiej Zolnierkiewicz : Added __init to pas_init_mixer()
+ */
+
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include "sound_config.h"
+
+#include "pas2.h"
+
+extern spinlock_t pas_lock;
+
+static int midi_busy, input_opened;
+static int my_dev;
+
+int pas2_mididev=-1;
+
+static unsigned char tmp_queue[256];
+static volatile int qlen;
+static volatile unsigned char qhead, qtail;
+
+static void (*midi_input_intr) (int dev, unsigned char data);
+
+static int pas_midi_open(int dev, int mode,
+ void (*input) (int dev, unsigned char data),
+ void (*output) (int dev)
+)
+{
+ int err;
+ unsigned long flags;
+ unsigned char ctrl;
+
+
+ if (midi_busy)
+ return -EBUSY;
+
+ /*
+ * Reset input and output FIFO pointers
+ */
+ pas_write(0x20 | 0x40,
+ 0x178b);
+
+ spin_lock_irqsave(&pas_lock, flags);
+
+ if ((err = pas_set_intr(0x10)) < 0)
+ {
+ spin_unlock_irqrestore(&pas_lock, flags);
+ return err;
+ }
+ /*
+ * Enable input available and output FIFO empty interrupts
+ */
+
+ ctrl = 0;
+ input_opened = 0;
+ midi_input_intr = input;
+
+ if (mode == OPEN_READ || mode == OPEN_READWRITE)
+ {
+ ctrl |= 0x04; /* Enable input */
+ input_opened = 1;
+ }
+ if (mode == OPEN_WRITE || mode == OPEN_READWRITE)
+ {
+ ctrl |= 0x08 | 0x10; /* Enable output */
+ }
+ pas_write(ctrl, 0x178b);
+
+ /*
+ * Acknowledge any pending interrupts
+ */
+
+ pas_write(0xff, 0x1B88);
+
+ spin_unlock_irqrestore(&pas_lock, flags);
+
+ midi_busy = 1;
+ qlen = qhead = qtail = 0;
+ return 0;
+}
+
+static void pas_midi_close(int dev)
+{
+
+ /*
+ * Reset FIFO pointers, disable intrs
+ */
+ pas_write(0x20 | 0x40, 0x178b);
+
+ pas_remove_intr(0x10);
+ midi_busy = 0;
+}
+
+static int dump_to_midi(unsigned char midi_byte)
+{
+ int fifo_space, x;
+
+ fifo_space = ((x = pas_read(0x1B89)) >> 4) & 0x0f;
+
+ /*
+ * The MIDI FIFO space register and it's documentation is nonunderstandable.
+ * There seem to be no way to differentiate between buffer full and buffer
+ * empty situations. For this reason we don't never write the buffer
+ * completely full. In this way we can assume that 0 (or is it 15)
+ * means that the buffer is empty.
+ */
+
+ if (fifo_space < 2 && fifo_space != 0) /* Full (almost) */
+ return 0; /* Ask upper layers to retry after some time */
+
+ pas_write(midi_byte, 0x178A);
+
+ return 1;
+}
+
+static int pas_midi_out(int dev, unsigned char midi_byte)
+{
+
+ unsigned long flags;
+
+ /*
+ * Drain the local queue first
+ */
+
+ spin_lock_irqsave(&pas_lock, flags);
+
+ while (qlen && dump_to_midi(tmp_queue[qhead]))
+ {
+ qlen--;
+ qhead++;
+ }
+
+ spin_unlock_irqrestore(&pas_lock, flags);
+
+ /*
+ * Output the byte if the local queue is empty.
+ */
+
+ if (!qlen)
+ if (dump_to_midi(midi_byte))
+ return 1;
+
+ /*
+ * Put to the local queue
+ */
+
+ if (qlen >= 256)
+ return 0; /* Local queue full */
+
+ spin_lock_irqsave(&pas_lock, flags);
+
+ tmp_queue[qtail] = midi_byte;
+ qlen++;
+ qtail++;
+
+ spin_unlock_irqrestore(&pas_lock, flags);
+
+ return 1;
+}
+
+static int pas_midi_start_read(int dev)
+{
+ return 0;
+}
+
+static int pas_midi_end_read(int dev)
+{
+ return 0;
+}
+
+static void pas_midi_kick(int dev)
+{
+}
+
+static int pas_buffer_status(int dev)
+{
+ return qlen;
+}
+
+#define MIDI_SYNTH_NAME "Pro Audio Spectrum Midi"
+#define MIDI_SYNTH_CAPS SYNTH_CAP_INPUT
+#include "midi_synth.h"
+
+static struct midi_operations pas_midi_operations =
+{
+ .owner = THIS_MODULE,
+ .info = {"Pro Audio Spectrum", 0, 0, SNDCARD_PAS},
+ .converter = &std_midi_synth,
+ .in_info = {0},
+ .open = pas_midi_open,
+ .close = pas_midi_close,
+ .outputc = pas_midi_out,
+ .start_read = pas_midi_start_read,
+ .end_read = pas_midi_end_read,
+ .kick = pas_midi_kick,
+ .buffer_status = pas_buffer_status,
+};
+
+void __init pas_midi_init(void)
+{
+ int dev = sound_alloc_mididev();
+
+ if (dev == -1)
+ {
+ printk(KERN_WARNING "pas_midi_init: Too many midi devices detected\n");
+ return;
+ }
+ std_midi_synth.midi_dev = my_dev = dev;
+ midi_devs[dev] = &pas_midi_operations;
+ pas2_mididev = dev;
+ sequencer_init();
+}
+
+void pas_midi_interrupt(void)
+{
+ unsigned char stat;
+ int i, incount;
+
+ stat = pas_read(0x1B88);
+
+ if (stat & 0x04) /* Input data available */
+ {
+ incount = pas_read(0x1B89) & 0x0f; /* Input FIFO size */
+ if (!incount)
+ incount = 16;
+
+ for (i = 0; i < incount; i++)
+ if (input_opened)
+ {
+ midi_input_intr(my_dev, pas_read(0x178A));
+ } else
+ pas_read(0x178A); /* Flush */
+ }
+ if (stat & (0x08 | 0x10))
+ {
+ spin_lock(&pas_lock);/* called in irq context */
+
+ while (qlen && dump_to_midi(tmp_queue[qhead]))
+ {
+ qlen--;
+ qhead++;
+ }
+
+ spin_unlock(&pas_lock);
+ }
+ if (stat & 0x40)
+ {
+ printk(KERN_WARNING "MIDI output overrun %x,%x\n", pas_read(0x1B89), stat);
+ }
+ pas_write(stat, 0x1B88); /* Acknowledge interrupts */
+}
Code Review / kvmfornfv.git / blobdiff