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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [drivers/] [sound/] [gus_midi.c] - Rev 1772
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/* * sound/gus2_midi.c * * The low level driver for the GUS Midi Interface. */ /* * Copyright (C) by Hannu Savolainen 1993-1996 * * USS/Lite 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. */ #include <linux/config.h> #include "sound_config.h" #include "gus_hw.h" #if defined(CONFIG_GUS) && defined(CONFIG_MIDI) static int midi_busy = 0, input_opened = 0; static int my_dev; static int output_used = 0; static volatile unsigned char gus_midi_control; static void (*midi_input_intr) (int dev, unsigned char data); static unsigned char tmp_queue[256]; static volatile int qlen; static volatile unsigned char qhead, qtail; extern int gus_base, gus_irq, gus_dma; extern int *gus_osp; static int GUS_MIDI_STATUS (void) { return inb (u_MidiStatus); } static int gus_midi_open (int dev, int mode, void (*input) (int dev, unsigned char data), void (*output) (int dev) ) { if (midi_busy) { printk ("GUS: Midi busy\n"); return -(EBUSY); } outb (MIDI_RESET, u_MidiControl); gus_delay (); gus_midi_control = 0; input_opened = 0; if (mode == OPEN_READ || mode == OPEN_READWRITE) { gus_midi_control |= MIDI_ENABLE_RCV; input_opened = 1; } outb (gus_midi_control, u_MidiControl); /* Enable */ midi_busy = 1; qlen = qhead = qtail = output_used = 0; midi_input_intr = input; return 0; } static int dump_to_midi (unsigned char midi_byte) { unsigned long flags; int ok = 0; output_used = 1; save_flags (flags); cli (); if (GUS_MIDI_STATUS () & MIDI_XMIT_EMPTY) { ok = 1; outb (midi_byte, u_MidiData); } else { /* * Enable Midi xmit interrupts (again) */ gus_midi_control |= MIDI_ENABLE_XMIT; outb (gus_midi_control, u_MidiControl); } restore_flags (flags); return ok; } static void gus_midi_close (int dev) { /* * Reset FIFO pointers, disable intrs */ outb (MIDI_RESET, u_MidiControl); midi_busy = 0; } static int gus_midi_out (int dev, unsigned char midi_byte) { unsigned long flags; /* * Drain the local queue first */ save_flags (flags); cli (); while (qlen && dump_to_midi (tmp_queue[qhead])) { qlen--; qhead++; } restore_flags (flags); /* * Output the byte if the local queue is empty. */ if (!qlen) if (dump_to_midi (midi_byte)) return 1; /* * OK */ /* * Put to the local queue */ if (qlen >= 256) return 0; /* * Local queue full */ save_flags (flags); cli (); tmp_queue[qtail] = midi_byte; qlen++; qtail++; restore_flags (flags); return 1; } static int gus_midi_start_read (int dev) { return 0; } static int gus_midi_end_read (int dev) { return 0; } static int gus_midi_ioctl (int dev, unsigned cmd, caddr_t arg) { return -(EINVAL); } static void gus_midi_kick (int dev) { } static int gus_midi_buffer_status (int dev) { unsigned long flags; if (!output_used) return 0; save_flags (flags); cli (); if (qlen && dump_to_midi (tmp_queue[qhead])) { qlen--; qhead++; } restore_flags (flags); return (qlen > 0) | !(GUS_MIDI_STATUS () & MIDI_XMIT_EMPTY); } #define MIDI_SYNTH_NAME "Gravis Ultrasound Midi" #define MIDI_SYNTH_CAPS SYNTH_CAP_INPUT #include "midi_synth.h" static struct midi_operations gus_midi_operations = { {"Gravis UltraSound Midi", 0, 0, SNDCARD_GUS}, &std_midi_synth, {0}, gus_midi_open, gus_midi_close, gus_midi_ioctl, gus_midi_out, gus_midi_start_read, gus_midi_end_read, gus_midi_kick, NULL, /* * command */ gus_midi_buffer_status, NULL }; void gus_midi_init (void) { if (num_midis >= MAX_MIDI_DEV) { printk ("Sound: Too many midi devices detected\n"); return; } outb (MIDI_RESET, u_MidiControl); std_midi_synth.midi_dev = my_dev = num_midis; midi_devs[num_midis++] = &gus_midi_operations; return; } void gus_midi_interrupt (int dummy) { volatile unsigned char stat, data; unsigned long flags; int timeout = 10; save_flags (flags); cli (); while (timeout-- > 0 && (stat = GUS_MIDI_STATUS ()) & (MIDI_RCV_FULL | MIDI_XMIT_EMPTY)) { if (stat & MIDI_RCV_FULL) { data = inb (u_MidiData); if (input_opened) midi_input_intr (my_dev, data); } if (stat & MIDI_XMIT_EMPTY) { while (qlen && dump_to_midi (tmp_queue[qhead])) { qlen--; qhead++; } if (!qlen) { /* * Disable Midi output interrupts, since no data in the buffer */ gus_midi_control &= ~MIDI_ENABLE_XMIT; outb (gus_midi_control, u_MidiControl); outb (gus_midi_control, u_MidiControl); } } } restore_flags (flags); } #endif
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