sound/oss/v_midi.c

   1 /*
   2  * sound/oss/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 static int v_midi_open (int dev, int mode,
  43               void            (*input) (int dev, unsigned char data),
  44               void            (*output) (int dev)
  45 )
  46 {
  47         vmidi_devc *devc = midi_devs[dev]->devc;
  48         unsigned long flags;
  49
  50         if (devc == NULL)
  51                 return -(ENXIO);
  52
  53         spin_lock_irqsave(&devc->lock,flags);
  54         if (devc->opened)
  55         {
  56                 spin_unlock_irqrestore(&devc->lock,flags);
  57                 return -(EBUSY);
  58         }
  59         devc->opened = 1;
  60         spin_unlock_irqrestore(&devc->lock,flags);
  61
  62         devc->intr_active = 1;
  63
  64         if (mode & OPEN_READ)
  65         {
  66                 devc->input_opened = 1;
  67                 devc->midi_input_intr = input;
  68         }
  69
  70         return 0;
  71 }
  72
  73 static void v_midi_close (int dev)
  74 {
  75         vmidi_devc *devc = midi_devs[dev]->devc;
  76         unsigned long flags;
  77
  78         if (devc == NULL)
  79                 return;
  80
  81         spin_lock_irqsave(&devc->lock,flags);
  82         devc->intr_active = 0;
  83         devc->input_opened = 0;
  84         devc->opened = 0;
  85         spin_unlock_irqrestore(&devc->lock,flags);
  86 }
  87
  88 static int v_midi_out (int dev, unsigned char midi_byte)
  89 {
  90         vmidi_devc *devc = midi_devs[dev]->devc;
  91         vmidi_devc *pdevc;
  92
  93         if (devc == NULL)
  94                 return -ENXIO;
  95
  96         pdevc = midi_devs[devc->pair_mididev]->devc;
  97         if (pdevc->input_opened > 0){
  98                 if (MIDIbuf_avail(pdevc->my_mididev) > 500)
  99                         return 0;
 100                 pdevc->midi_input_intr (pdevc->my_mididev, midi_byte);
 101         }
 102         return 1;
 103 }
 104
 105 static inline int v_midi_start_read (int dev)
 106 {
 107         return 0;
 108 }
 109
 110 static int v_midi_end_read (int dev)
 111 {
 112         vmidi_devc *devc = midi_devs[dev]->devc;
 113         if (devc == NULL)
 114                 return -ENXIO;
 115
 116         devc->intr_active = 0;
 117         return 0;
 118 }
 119
 120 /* why -EPERM and not -EINVAL?? */
 121
 122 static inline int v_midi_ioctl (int dev, unsigned cmd, void __user *arg)
 123 {
 124         return -EPERM;
 125 }
 126
 127
 128 #define MIDI_SYNTH_NAME "Loopback MIDI"
 129 #define MIDI_SYNTH_CAPS SYNTH_CAP_INPUT
 130
 131 #include "midi_synth.h"
 132
 133 static struct midi_operations v_midi_operations =
 134 {
 135         .owner          = THIS_MODULE,
 136         .info           = {"Loopback MIDI Port 1", 0, 0, SNDCARD_VMIDI},
 137         .converter      = &std_midi_synth,
 138         .in_info        = {0},
 139         .open           = v_midi_open,
 140         .close          = v_midi_close,
 141         .ioctl          = v_midi_ioctl,
 142         .outputc        = v_midi_out,
 143         .start_read     = v_midi_start_read,
 144         .end_read       = v_midi_end_read,
 145 };
 146
 147 static struct midi_operations v_midi_operations2 =
 148 {
 149         .owner          = THIS_MODULE,
 150         .info           = {"Loopback MIDI Port 2", 0, 0, SNDCARD_VMIDI},
 151         .converter      = &std_midi_synth,
 152         .in_info        = {0},
 153         .open           = v_midi_open,
 154         .close          = v_midi_close,
 155         .ioctl          = v_midi_ioctl,
 156         .outputc        = v_midi_out,
 157         .start_read     = v_midi_start_read,
 158         .end_read       = v_midi_end_read,
 159 };
 160
 161 /*
 162  *      We kmalloc just one of these - it makes life simpler and the code
 163  *      cleaner and the memory handling far more efficient
 164  */
 165
 166 struct vmidi_memory
 167 {
 168         /* Must be first */
 169         struct midi_operations m_ops[2];
 170         struct synth_operations s_ops[2];
 171         struct vmidi_devc v_ops[2];
 172 };
 173
 174 static void __init attach_v_midi (struct address_info *hw_config)
 175 {
 176         struct vmidi_memory *m;
 177         /* printk("Attaching v_midi device.....\n"); */
 178
 179         midi1 = sound_alloc_mididev();
 180         if (midi1 == -1)
 181         {
 182                 printk(KERN_ERR "v_midi: Too many midi devices detected\n");
 183                 return;
 184         }
 185
 186         m = kmalloc(sizeof(struct vmidi_memory), GFP_KERNEL);
 187         if (m == NULL)
 188         {
 189                 printk(KERN_WARNING "Loopback MIDI: Failed to allocate memory\n");
 190                 sound_unload_mididev(midi1);
 191                 return;
 192         }
 193
 194         midi_mem = m;
 195
 196         midi_devs[midi1] = &m->m_ops[0];
 197
 198
 199         midi2 = sound_alloc_mididev();
 200         if (midi2 == -1)
 201         {
 202                 printk (KERN_ERR "v_midi: Too many midi devices detected\n");
 203                 kfree(m);
 204                 sound_unload_mididev(midi1);
 205                 return;
 206         }
 207
 208         midi_devs[midi2] = &m->m_ops[1];
 209
 210         /* printk("VMIDI1: %d   VMIDI2: %d\n",midi1,midi2); */
 211
 212         /* for MIDI-1 */
 213         v_devc[0] = &m->v_ops[0];
 214         memcpy ((char *) midi_devs[midi1], (char *) &v_midi_operations,
 215                 sizeof (struct midi_operations));
 216
 217         v_devc[0]->my_mididev = midi1;
 218         v_devc[0]->pair_mididev = midi2;
 219         v_devc[0]->opened = v_devc[0]->input_opened = 0;
 220         v_devc[0]->intr_active = 0;
 221         v_devc[0]->midi_input_intr = NULL;
 222         spin_lock_init(&v_devc[0]->lock);
 223
 224         midi_devs[midi1]->devc = v_devc[0];
 225
 226         midi_devs[midi1]->converter = &m->s_ops[0];
 227         std_midi_synth.midi_dev = midi1;
 228         memcpy ((char *) midi_devs[midi1]->converter, (char *) &std_midi_synth,
 229                 sizeof (struct synth_operations));
 230         midi_devs[midi1]->converter->id = "V_MIDI 1";
 231
 232         /* for MIDI-2 */
 233         v_devc[1] = &m->v_ops[1];
 234
 235         memcpy ((char *) midi_devs[midi2], (char *) &v_midi_operations2,
 236                 sizeof (struct midi_operations));
 237
 238         v_devc[1]->my_mididev = midi2;
 239         v_devc[1]->pair_mididev = midi1;
 240         v_devc[1]->opened = v_devc[1]->input_opened = 0;
 241         v_devc[1]->intr_active = 0;
 242         v_devc[1]->midi_input_intr = NULL;
 243         spin_lock_init(&v_devc[1]->lock);
 244
 245         midi_devs[midi2]->devc = v_devc[1];
 246         midi_devs[midi2]->converter = &m->s_ops[1];
 247
 248         std_midi_synth.midi_dev = midi2;
 249         memcpy ((char *) midi_devs[midi2]->converter, (char *) &std_midi_synth,
 250                 sizeof (struct synth_operations));
 251         midi_devs[midi2]->converter->id = "V_MIDI 2";
 252
 253         sequencer_init();
 254         /* printk("Attached v_midi device\n"); */
 255 }
 256
 257 static inline int __init probe_v_midi(struct address_info *hw_config)
 258 {
 259         return(1);      /* always OK */
 260 }
 261
 262
 263 static void __exit unload_v_midi(struct address_info *hw_config)
 264 {
 265         sound_unload_mididev(midi1);
 266         sound_unload_mididev(midi2);
 267         kfree(midi_mem);
 268 }
 269
 270 static struct address_info cfg; /* dummy */
 271
 272 static int __init init_vmidi(void)
 273 {
 274         printk("MIDI Loopback device driver\n");
 275         if (!probe_v_midi(&cfg))
 276                 return -ENODEV;
 277         attach_v_midi(&cfg);
 278
 279         return 0;
 280 }
 281
 282 static void __exit cleanup_vmidi(void)
 283 {
 284         unload_v_midi(&cfg);
 285 }
 286
 287 module_init(init_vmidi);
 288 module_exit(cleanup_vmidi);
 289 MODULE_LICENSE("GPL");