sound/oss/v_midi.c

   1 /*
   2  * sound/v_midi.c
   3  *
   4  * The low level driver for the Sound Blaster DS chips.
   5  *
   6  *
   7  * Copyright (C) by Hannu Savolainen 1993-1996
   8  *
   9  * USS/Lite for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
  10  * Version 2 (June 1991). See the "COPYING" file distributed with this software
  11  * for more info.
  12  * ??
  13  *
  14  * Changes
  15  *      Alan Cox                Modularisation, changed memory allocations
  16  *      Christoph Hellwig       Adapted to module_init/module_exit
  17  *
  18  * Status
  19  *      Untested
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/module.h>
  24 #include <linux/spinlock.h>
  25 #include "sound_config.h"
  26
  27 #include "v_midi.h"
  28
  29 static vmidi_devc *v_devc[2] = { NULL, NULL};
  30 static int midi1,midi2;
  31 static void *midi_mem = NULL;
  32
  33 /*
  34  * The DSP channel can be used either for input or output. Variable
  35  * 'sb_irq_mode' will be set when the program calls read or write first time
  36  * after open. Current version doesn't support mode changes without closing
  37  * and reopening the device. Support for this feature may be implemented in a
  38  * future version of this driver.
  39  */
  40
  41
  42 void            (*midi_input_intr) (int dev, unsigned char data);
  43
  44 static int v_midi_open (int dev, int mode,
  45               void            (*input) (int dev, unsigned char data),
  46               void            (*output) (int dev)
  47 )
  48 {
  49         vmidi_devc *devc = midi_devs[dev]->devc;
  50         unsigned long flags;
  51
  52         if (devc == NULL)
  53                 return -(ENXIO);
  54
  55         spin_lock_irqsave(&devc->lock,flags);
  56         if (devc->opened)
  57         {
  58                 spin_unlock_irqrestore(&devc->lock,flags);
  59                 return -(EBUSY);
  60         }
  61         devc->opened = 1;
  62         spin_unlock_irqrestore(&devc->lock,flags);
  63
  64         devc->intr_active = 1;
  65
  66         if (mode & OPEN_READ)
  67         {
  68                 devc->input_opened = 1;
  69                 devc->midi_input_intr = input;
  70         }
  71
  72         return 0;
  73 }
  74
  75 static void v_midi_close (int dev)
  76 {
  77         vmidi_devc *devc = midi_devs[dev]->devc;
  78         unsigned long flags;
  79
  80         if (devc == NULL)
  81                 return;
  82
  83         spin_lock_irqsave(&devc->lock,flags);
  84         devc->intr_active = 0;
  85         devc->input_opened = 0;
  86         devc->opened = 0;
  87         spin_unlock_irqrestore(&devc->lock,flags);
  88 }
  89
  90 static int v_midi_out (int dev, unsigned char midi_byte)
  91 {
  92         vmidi_devc *devc = midi_devs[dev]->devc;
  93         vmidi_devc *pdevc;
  94
  95         if (devc == NULL)
  96                 return -ENXIO;
  97
  98         pdevc = midi_devs[devc->pair_mididev]->devc;
  99         if (pdevc->input_opened > 0){
 100                 if (MIDIbuf_avail(pdevc->my_mididev) > 500)
 101                         return 0;
 102                 pdevc->midi_input_intr (pdevc->my_mididev, midi_byte);
 103         }
 104         return 1;
 105 }
 106
 107 static inline int v_midi_start_read (int dev)
 108 {
 109         return 0;
 110 }
 111
 112 static int v_midi_end_read (int dev)
 113 {
 114         vmidi_devc *devc = midi_devs[dev]->devc;
 115         if (devc == NULL)
 116                 return -ENXIO;
 117
 118         devc->intr_active = 0;
 119         return 0;
 120 }
 121
 122 /* why -EPERM and not -EINVAL?? */
 123
 124 static inline int v_midi_ioctl (int dev, unsigned cmd, void __user *arg)
 125 {
 126         return -EPERM;
 127 }
 128
 129
 130 #define MIDI_SYNTH_NAME "Loopback MIDI"
 131 #define MIDI_SYNTH_CAPS SYNTH_CAP_INPUT
 132
 133 #include "midi_synth.h"
 134
 135 static struct midi_operations v_midi_operations =
 136 {
 137         .owner          = THIS_MODULE,
 138         .info           = {"Loopback MIDI Port 1", 0, 0, SNDCARD_VMIDI},
 139         .converter      = &std_midi_synth,
 140         .in_info        = {0},
 141         .open           = v_midi_open,
 142         .close          = v_midi_close,
 143         .ioctl          = v_midi_ioctl,
 144         .outputc        = v_midi_out,
 145         .start_read     = v_midi_start_read,
 146         .end_read       = v_midi_end_read,
 147 };
 148
 149 static struct midi_operations v_midi_operations2 =
 150 {
 151         .owner          = THIS_MODULE,
 152         .info           = {"Loopback MIDI Port 2", 0, 0, SNDCARD_VMIDI},
 153         .converter      = &std_midi_synth,
 154         .in_info        = {0},
 155         .open           = v_midi_open,
 156         .close          = v_midi_close,
 157         .ioctl          = v_midi_ioctl,
 158         .outputc        = v_midi_out,
 159         .start_read     = v_midi_start_read,
 160         .end_read       = v_midi_end_read,
 161 };
 162
 163 /*
 164  *      We kmalloc just one of these - it makes life simpler and the code
 165  *      cleaner and the memory handling far more efficient
 166  */
 167
 168 struct vmidi_memory
 169 {
 170         /* Must be first */
 171         struct midi_operations m_ops[2];
 172         struct synth_operations s_ops[2];
 173         struct vmidi_devc v_ops[2];
 174 };
 175
 176 static void __init attach_v_midi (struct address_info *hw_config)
 177 {
 178         struct vmidi_memory *m;
 179         /* printk("Attaching v_midi device.....\n"); */
 180
 181         midi1 = sound_alloc_mididev();
 182         if (midi1 == -1)
 183         {
 184                 printk(KERN_ERR "v_midi: Too many midi devices detected\n");
 185                 return;
 186         }
 187
 188         m=(struct vmidi_memory *)kmalloc(sizeof(struct vmidi_memory), GFP_KERNEL);
 189         if (m == NULL)
 190         {
 191                 printk(KERN_WARNING "Loopback MIDI: Failed to allocate memory\n");
 192                 sound_unload_mididev(midi1);
 193                 return;
 194         }
 195
 196         midi_mem = m;
 197
 198         midi_devs[midi1] = &m->m_ops[0];
 199
 200
 201         midi2 = sound_alloc_mididev();
 202         if (midi2 == -1)
 203         {
 204                 printk (KERN_ERR "v_midi: Too many midi devices detected\n");
 205                 kfree(m);
 206                 sound_unload_mididev(midi1);
 207                 return;
 208         }
 209
 210         midi_devs[midi2] = &m->m_ops[1];
 211
 212         /* printk("VMIDI1: %d   VMIDI2: %d\n",midi1,midi2); */
 213
 214         /* for MIDI-1 */
 215         v_devc[0] = &m->v_ops[0];
 216         memcpy ((char *) midi_devs[midi1], (char *) &v_midi_operations,
 217                 sizeof (struct midi_operations));
 218
 219         v_devc[0]->my_mididev = midi1;
 220         v_devc[0]->pair_mididev = midi2;
 221         v_devc[0]->opened = v_devc[0]->input_opened = 0;
 222         v_devc[0]->intr_active = 0;
 223         v_devc[0]->midi_input_intr = NULL;
 224         spin_lock_init(&v_devc[0]->lock);
 225
 226         midi_devs[midi1]->devc = v_devc[0];
 227
 228         midi_devs[midi1]->converter = &m->s_ops[0];
 229         std_midi_synth.midi_dev = midi1;
 230         memcpy ((char *) midi_devs[midi1]->converter, (char *) &std_midi_synth,
 231                 sizeof (struct synth_operations));
 232         midi_devs[midi1]->converter->id = "V_MIDI 1";
 233
 234         /* for MIDI-2 */
 235         v_devc[1] = &m->v_ops[1];
 236
 237         memcpy ((char *) midi_devs[midi2], (char *) &v_midi_operations2,
 238                 sizeof (struct midi_operations));
 239
 240         v_devc[1]->my_mididev = midi2;
 241         v_devc[1]->pair_mididev = midi1;
 242         v_devc[1]->opened = v_devc[1]->input_opened = 0;
 243         v_devc[1]->intr_active = 0;
 244         v_devc[1]->midi_input_intr = NULL;
 245         spin_lock_init(&v_devc[1]->lock);
 246
 247         midi_devs[midi2]->devc = v_devc[1];
 248         midi_devs[midi2]->converter = &m->s_ops[1];
 249
 250         std_midi_synth.midi_dev = midi2;
 251         memcpy ((char *) midi_devs[midi2]->converter, (char *) &std_midi_synth,
 252                 sizeof (struct synth_operations));
 253         midi_devs[midi2]->converter->id = "V_MIDI 2";
 254
 255         sequencer_init();
 256         /* printk("Attached v_midi device\n"); */
 257 }
 258
 259 static inline int __init probe_v_midi(struct address_info *hw_config)
 260 {
 261         return(1);      /* always OK */
 262 }
 263
 264
 265 static void __exit unload_v_midi(struct address_info *hw_config)
 266 {
 267         sound_unload_mididev(midi1);
 268         sound_unload_mididev(midi2);
 269         kfree(midi_mem);
 270 }
 271
 272 static struct address_info cfg; /* dummy */
 273
 274 static int __init init_vmidi(void)
 275 {
 276         printk("MIDI Loopback device driver\n");
 277         if (!probe_v_midi(&cfg))
 278                 return -ENODEV;
 279         attach_v_midi(&cfg);
 280
 281         return 0;
 282 }
 283
 284 static void __exit cleanup_vmidi(void)
 285 {
 286         unload_v_midi(&cfg);
 287 }
 288
 289 module_init(init_vmidi);
 290 module_exit(cleanup_vmidi);
 291 MODULE_LICENSE("GPL");