428 строки
8.6 KiB
C
428 строки
8.6 KiB
C
/*
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* sound/oss/midibuf.c
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*
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* Device file manager for /dev/midi#
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*/
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/*
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* Copyright (C) by Hannu Savolainen 1993-1997
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*
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* OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
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* Version 2 (June 1991). See the "COPYING" file distributed with this software
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* for more info.
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*/
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/*
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* Thomas Sailer : ioctl code reworked (vmalloc/vfree removed)
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*/
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#include <linux/stddef.h>
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#include <linux/kmod.h>
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#include <linux/spinlock.h>
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#include <linux/sched/signal.h>
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#define MIDIBUF_C
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#include "sound_config.h"
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/*
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* Don't make MAX_QUEUE_SIZE larger than 4000
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*/
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#define MAX_QUEUE_SIZE 4000
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static wait_queue_head_t midi_sleeper[MAX_MIDI_DEV];
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static wait_queue_head_t input_sleeper[MAX_MIDI_DEV];
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struct midi_buf
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{
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int len, head, tail;
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unsigned char queue[MAX_QUEUE_SIZE];
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};
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struct midi_parms
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{
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long prech_timeout; /*
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* Timeout before the first ch
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*/
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};
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static struct midi_buf *midi_out_buf[MAX_MIDI_DEV] = {NULL};
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static struct midi_buf *midi_in_buf[MAX_MIDI_DEV] = {NULL};
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static struct midi_parms parms[MAX_MIDI_DEV];
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static void midi_poll(unsigned long dummy);
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static DEFINE_TIMER(poll_timer, midi_poll, 0, 0);
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static volatile int open_devs;
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static DEFINE_SPINLOCK(lock);
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#define DATA_AVAIL(q) (q->len)
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#define SPACE_AVAIL(q) (MAX_QUEUE_SIZE - q->len)
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#define QUEUE_BYTE(q, data) \
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if (SPACE_AVAIL(q)) \
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{ \
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unsigned long flags; \
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spin_lock_irqsave(&lock, flags); \
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q->queue[q->tail] = (data); \
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q->len++; q->tail = (q->tail+1) % MAX_QUEUE_SIZE; \
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spin_unlock_irqrestore(&lock, flags); \
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}
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#define REMOVE_BYTE(q, data) \
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if (DATA_AVAIL(q)) \
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{ \
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unsigned long flags; \
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spin_lock_irqsave(&lock, flags); \
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data = q->queue[q->head]; \
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q->len--; q->head = (q->head+1) % MAX_QUEUE_SIZE; \
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spin_unlock_irqrestore(&lock, flags); \
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}
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static void drain_midi_queue(int dev)
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{
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/*
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* Give the Midi driver time to drain its output queues
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*/
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if (midi_devs[dev]->buffer_status != NULL)
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wait_event_interruptible_timeout(midi_sleeper[dev],
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!midi_devs[dev]->buffer_status(dev), HZ/10);
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}
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static void midi_input_intr(int dev, unsigned char data)
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{
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if (midi_in_buf[dev] == NULL)
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return;
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if (data == 0xfe) /*
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* Active sensing
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*/
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return; /*
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* Ignore
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*/
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if (SPACE_AVAIL(midi_in_buf[dev])) {
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QUEUE_BYTE(midi_in_buf[dev], data);
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wake_up(&input_sleeper[dev]);
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}
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}
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static void midi_output_intr(int dev)
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{
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/*
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* Currently NOP
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*/
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}
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static void midi_poll(unsigned long dummy)
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{
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unsigned long flags;
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int dev;
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spin_lock_irqsave(&lock, flags);
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if (open_devs)
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{
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for (dev = 0; dev < num_midis; dev++)
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if (midi_devs[dev] != NULL && midi_out_buf[dev] != NULL)
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{
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while (DATA_AVAIL(midi_out_buf[dev]))
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{
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int ok;
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int c = midi_out_buf[dev]->queue[midi_out_buf[dev]->head];
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spin_unlock_irqrestore(&lock,flags);/* Give some time to others */
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ok = midi_devs[dev]->outputc(dev, c);
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spin_lock_irqsave(&lock, flags);
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if (!ok)
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break;
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midi_out_buf[dev]->head = (midi_out_buf[dev]->head + 1) % MAX_QUEUE_SIZE;
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midi_out_buf[dev]->len--;
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}
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if (DATA_AVAIL(midi_out_buf[dev]) < 100)
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wake_up(&midi_sleeper[dev]);
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}
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poll_timer.expires = (1) + jiffies;
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add_timer(&poll_timer);
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/*
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* Come back later
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*/
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}
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spin_unlock_irqrestore(&lock, flags);
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}
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int MIDIbuf_open(int dev, struct file *file)
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{
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int mode, err;
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dev = dev >> 4;
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mode = translate_mode(file);
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if (num_midis > MAX_MIDI_DEV)
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{
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printk(KERN_ERR "midi: Too many midi interfaces\n");
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num_midis = MAX_MIDI_DEV;
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}
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if (dev < 0 || dev >= num_midis || midi_devs[dev] == NULL)
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return -ENXIO;
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/*
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* Interrupts disabled. Be careful
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*/
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module_put(midi_devs[dev]->owner);
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if ((err = midi_devs[dev]->open(dev, mode,
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midi_input_intr, midi_output_intr)) < 0)
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return err;
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parms[dev].prech_timeout = MAX_SCHEDULE_TIMEOUT;
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midi_in_buf[dev] = vmalloc(sizeof(struct midi_buf));
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if (midi_in_buf[dev] == NULL)
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{
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printk(KERN_WARNING "midi: Can't allocate buffer\n");
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midi_devs[dev]->close(dev);
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return -EIO;
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}
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midi_in_buf[dev]->len = midi_in_buf[dev]->head = midi_in_buf[dev]->tail = 0;
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midi_out_buf[dev] = vmalloc(sizeof(struct midi_buf));
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if (midi_out_buf[dev] == NULL)
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{
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printk(KERN_WARNING "midi: Can't allocate buffer\n");
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midi_devs[dev]->close(dev);
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vfree(midi_in_buf[dev]);
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midi_in_buf[dev] = NULL;
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return -EIO;
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}
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midi_out_buf[dev]->len = midi_out_buf[dev]->head = midi_out_buf[dev]->tail = 0;
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open_devs++;
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init_waitqueue_head(&midi_sleeper[dev]);
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init_waitqueue_head(&input_sleeper[dev]);
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if (open_devs < 2) /* This was first open */
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{
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poll_timer.expires = 1 + jiffies;
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add_timer(&poll_timer); /* Start polling */
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}
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return err;
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}
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void MIDIbuf_release(int dev, struct file *file)
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{
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int mode;
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dev = dev >> 4;
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mode = translate_mode(file);
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if (dev < 0 || dev >= num_midis || midi_devs[dev] == NULL)
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return;
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/*
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* Wait until the queue is empty
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*/
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if (mode != OPEN_READ)
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{
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midi_devs[dev]->outputc(dev, 0xfe); /*
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* Active sensing to shut the
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* devices
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*/
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wait_event_interruptible(midi_sleeper[dev],
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!DATA_AVAIL(midi_out_buf[dev]));
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/*
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* Sync
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*/
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drain_midi_queue(dev); /*
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* Ensure the output queues are empty
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*/
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}
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midi_devs[dev]->close(dev);
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open_devs--;
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if (open_devs == 0)
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del_timer_sync(&poll_timer);
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vfree(midi_in_buf[dev]);
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vfree(midi_out_buf[dev]);
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midi_in_buf[dev] = NULL;
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midi_out_buf[dev] = NULL;
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module_put(midi_devs[dev]->owner);
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}
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int MIDIbuf_write(int dev, struct file *file, const char __user *buf, int count)
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{
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int c, n, i;
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unsigned char tmp_data;
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dev = dev >> 4;
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if (!count)
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return 0;
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c = 0;
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while (c < count)
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{
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n = SPACE_AVAIL(midi_out_buf[dev]);
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if (n == 0) { /*
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* No space just now.
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*/
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if (file->f_flags & O_NONBLOCK) {
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c = -EAGAIN;
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goto out;
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}
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if (wait_event_interruptible(midi_sleeper[dev],
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SPACE_AVAIL(midi_out_buf[dev])))
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{
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c = -EINTR;
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goto out;
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}
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n = SPACE_AVAIL(midi_out_buf[dev]);
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}
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if (n > (count - c))
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n = count - c;
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for (i = 0; i < n; i++)
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{
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/* BROKE BROKE BROKE - CAN'T DO THIS WITH CLI !! */
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/* yes, think the same, so I removed the cli() brackets
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QUEUE_BYTE is protected against interrupts */
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if (copy_from_user((char *) &tmp_data, &(buf)[c], 1)) {
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c = -EFAULT;
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goto out;
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}
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QUEUE_BYTE(midi_out_buf[dev], tmp_data);
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c++;
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}
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}
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out:
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return c;
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}
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int MIDIbuf_read(int dev, struct file *file, char __user *buf, int count)
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{
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int n, c = 0;
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unsigned char tmp_data;
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dev = dev >> 4;
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if (!DATA_AVAIL(midi_in_buf[dev])) { /*
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* No data yet, wait
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*/
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if (file->f_flags & O_NONBLOCK) {
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c = -EAGAIN;
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goto out;
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}
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wait_event_interruptible_timeout(input_sleeper[dev],
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DATA_AVAIL(midi_in_buf[dev]),
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parms[dev].prech_timeout);
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if (signal_pending(current))
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c = -EINTR; /* The user is getting restless */
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}
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if (c == 0 && DATA_AVAIL(midi_in_buf[dev])) /*
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* Got some bytes
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*/
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{
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n = DATA_AVAIL(midi_in_buf[dev]);
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if (n > count)
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n = count;
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c = 0;
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while (c < n)
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{
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char *fixit;
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REMOVE_BYTE(midi_in_buf[dev], tmp_data);
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fixit = (char *) &tmp_data;
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/* BROKE BROKE BROKE */
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/* yes removed the cli() brackets again
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should q->len,tail&head be atomic_t? */
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if (copy_to_user(&(buf)[c], fixit, 1)) {
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c = -EFAULT;
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goto out;
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}
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c++;
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}
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}
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out:
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return c;
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}
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int MIDIbuf_ioctl(int dev, struct file *file,
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unsigned int cmd, void __user *arg)
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{
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int val;
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dev = dev >> 4;
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if (((cmd >> 8) & 0xff) == 'C')
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{
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if (midi_devs[dev]->coproc) /* Coprocessor ioctl */
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return midi_devs[dev]->coproc->ioctl(midi_devs[dev]->coproc->devc, cmd, arg, 0);
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/* printk("/dev/midi%d: No coprocessor for this device\n", dev);*/
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return -ENXIO;
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}
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else
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{
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switch (cmd)
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{
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case SNDCTL_MIDI_PRETIME:
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if (get_user(val, (int __user *)arg))
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return -EFAULT;
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if (val < 0)
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val = 0;
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val = (HZ * val) / 10;
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parms[dev].prech_timeout = val;
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return put_user(val, (int __user *)arg);
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default:
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if (!midi_devs[dev]->ioctl)
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return -EINVAL;
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return midi_devs[dev]->ioctl(dev, cmd, arg);
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}
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}
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}
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/* No kernel lock - fine */
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unsigned int MIDIbuf_poll(int dev, struct file *file, poll_table * wait)
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{
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unsigned int mask = 0;
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dev = dev >> 4;
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/* input */
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poll_wait(file, &input_sleeper[dev], wait);
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if (DATA_AVAIL(midi_in_buf[dev]))
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mask |= POLLIN | POLLRDNORM;
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/* output */
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poll_wait(file, &midi_sleeper[dev], wait);
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if (!SPACE_AVAIL(midi_out_buf[dev]))
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mask |= POLLOUT | POLLWRNORM;
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return mask;
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}
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int MIDIbuf_avail(int dev)
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{
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if (midi_in_buf[dev])
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return DATA_AVAIL (midi_in_buf[dev]);
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return 0;
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}
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EXPORT_SYMBOL(MIDIbuf_avail);
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