summaryrefslogtreecommitdiff
path: root/sound/oss/v_midi.c
blob: f0b4151d9b17c4abfe0dfff99bbce86759aea939 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
/*
 * sound/oss/v_midi.c
 *
 * The low level driver for the Sound Blaster DS chips.
 *
 *
 * 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.
 * ??
 *
 * Changes
 *	Alan Cox		Modularisation, changed memory allocations
 *	Christoph Hellwig	Adapted to module_init/module_exit
 *
 * Status
 *	Untested
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include "sound_config.h"

#include "v_midi.h"

static vmidi_devc *v_devc[2] = { NULL, NULL};
static int midi1,midi2;
static void *midi_mem = NULL;

/*
 * The DSP channel can be used either for input or output. Variable
 * 'sb_irq_mode' will be set when the program calls read or write first time
 * after open. Current version doesn't support mode changes without closing
 * and reopening the device. Support for this feature may be implemented in a
 * future version of this driver.
 */


static int v_midi_open (int dev, int mode,
	      void            (*input) (int dev, unsigned char data),
	      void            (*output) (int dev)
)
{
	vmidi_devc *devc = midi_devs[dev]->devc;
	unsigned long flags;

	if (devc == NULL)
		return -(ENXIO);

	spin_lock_irqsave(&devc->lock,flags);
	if (devc->opened)
	{
		spin_unlock_irqrestore(&devc->lock,flags);
		return -(EBUSY);
	}
	devc->opened = 1;
	spin_unlock_irqrestore(&devc->lock,flags);

	devc->intr_active = 1;

	if (mode & OPEN_READ)
	{
		devc->input_opened = 1;
		devc->midi_input_intr = input;
	}

	return 0;
}

static void v_midi_close (int dev)
{
	vmidi_devc *devc = midi_devs[dev]->devc;
	unsigned long flags;

	if (devc == NULL)
		return;

	spin_lock_irqsave(&devc->lock,flags);
	devc->intr_active = 0;
	devc->input_opened = 0;
	devc->opened = 0;
	spin_unlock_irqrestore(&devc->lock,flags);
}

static int v_midi_out (int dev, unsigned char midi_byte)
{
	vmidi_devc *devc = midi_devs[dev]->devc;
	vmidi_devc *pdevc;

	if (devc == NULL)
		return -ENXIO;

	pdevc = midi_devs[devc->pair_mididev]->devc;
	if (pdevc->input_opened > 0){
		if (MIDIbuf_avail(pdevc->my_mididev) > 500)
			return 0;
		pdevc->midi_input_intr (pdevc->my_mididev, midi_byte);
	}
	return 1;
}

static inline int v_midi_start_read (int dev)
{
	return 0;
}

static int v_midi_end_read (int dev)
{
	vmidi_devc *devc = midi_devs[dev]->devc;
	if (devc == NULL)
		return -ENXIO;

	devc->intr_active = 0;
	return 0;
}

/* why -EPERM and not -EINVAL?? */

static inline int v_midi_ioctl (int dev, unsigned cmd, void __user *arg)
{
	return -EPERM;
}


#define MIDI_SYNTH_NAME	"Loopback MIDI"
#define MIDI_SYNTH_CAPS	SYNTH_CAP_INPUT

#include "midi_synth.h"

static struct midi_operations v_midi_operations =
{
	.owner		= THIS_MODULE,
	.info		= {"Loopback MIDI Port 1", 0, 0, SNDCARD_VMIDI},
	.converter	= &std_midi_synth,
	.in_info	= {0},
	.open		= v_midi_open,
	.close		= v_midi_close,
	.ioctl		= v_midi_ioctl,
	.outputc	= v_midi_out,
	.start_read	= v_midi_start_read,
	.end_read	= v_midi_end_read,
};

static struct midi_operations v_midi_operations2 =
{
	.owner		= THIS_MODULE,
	.info		= {"Loopback MIDI Port 2", 0, 0, SNDCARD_VMIDI},
	.converter	= &std_midi_synth,
	.in_info	= {0},
	.open		= v_midi_open,
	.close		= v_midi_close,
	.ioctl		= v_midi_ioctl,
	.outputc	= v_midi_out,
	.start_read	= v_midi_start_read,
	.end_read	= v_midi_end_read,
};

/*
 *	We kmalloc just one of these - it makes life simpler and the code
 *	cleaner and the memory handling far more efficient
 */
 
struct vmidi_memory
{
	/* Must be first */
	struct midi_operations m_ops[2];
	struct synth_operations s_ops[2];
	struct vmidi_devc v_ops[2];
};

static void __init attach_v_midi (struct address_info *hw_config)
{
	struct vmidi_memory *m;
	/* printk("Attaching v_midi device.....\n"); */

	midi1 = sound_alloc_mididev();
	if (midi1 == -1)
	{
		printk(KERN_ERR "v_midi: Too many midi devices detected\n");
		return;
	}
	
	m = kmalloc(sizeof(struct vmidi_memory), GFP_KERNEL);
	if (m == NULL)
	{
		printk(KERN_WARNING "Loopback MIDI: Failed to allocate memory\n");
		sound_unload_mididev(midi1);
		return;
	}
	
	midi_mem = m;
	
	midi_devs[midi1] = &m->m_ops[0];
	

	midi2 = sound_alloc_mididev();
	if (midi2 == -1)
	{
		printk (KERN_ERR "v_midi: Too many midi devices detected\n");
		kfree(m);
		sound_unload_mididev(midi1);
		return;
	}

	midi_devs[midi2] = &m->m_ops[1];

	/* printk("VMIDI1: %d   VMIDI2: %d\n",midi1,midi2); */

	/* for MIDI-1 */
	v_devc[0] = &m->v_ops[0];
	memcpy ((char *) midi_devs[midi1], (char *) &v_midi_operations,
		sizeof (struct midi_operations));

	v_devc[0]->my_mididev = midi1;
	v_devc[0]->pair_mididev = midi2;
	v_devc[0]->opened = v_devc[0]->input_opened = 0;
	v_devc[0]->intr_active = 0;
	v_devc[0]->midi_input_intr = NULL;
	spin_lock_init(&v_devc[0]->lock);

	midi_devs[midi1]->devc = v_devc[0];

	midi_devs[midi1]->converter = &m->s_ops[0];
	std_midi_synth.midi_dev = midi1;
	memcpy ((char *) midi_devs[midi1]->converter, (char *) &std_midi_synth,
		sizeof (struct synth_operations));
	midi_devs[midi1]->converter->id = "V_MIDI 1";

	/* for MIDI-2 */
	v_devc[1] = &m->v_ops[1];

	memcpy ((char *) midi_devs[midi2], (char *) &v_midi_operations2,
		sizeof (struct midi_operations));

	v_devc[1]->my_mididev = midi2;
	v_devc[1]->pair_mididev = midi1;
	v_devc[1]->opened = v_devc[1]->input_opened = 0;
	v_devc[1]->intr_active = 0;
	v_devc[1]->midi_input_intr = NULL;
	spin_lock_init(&v_devc[1]->lock);

	midi_devs[midi2]->devc = v_devc[1];
	midi_devs[midi2]->converter = &m->s_ops[1];

	std_midi_synth.midi_dev = midi2;
	memcpy ((char *) midi_devs[midi2]->converter, (char *) &std_midi_synth,
		sizeof (struct synth_operations));
	midi_devs[midi2]->converter->id = "V_MIDI 2";

	sequencer_init();
	/* printk("Attached v_midi device\n"); */
}

static inline int __init probe_v_midi(struct address_info *hw_config)
{
	return(1);	/* always OK */
}


static void __exit unload_v_midi(struct address_info *hw_config)
{
	sound_unload_mididev(midi1);
	sound_unload_mididev(midi2);
	kfree(midi_mem);
}

static struct address_info cfg; /* dummy */

static int __init init_vmidi(void)
{
	printk("MIDI Loopback device driver\n");
	if (!probe_v_midi(&cfg))
		return -ENODEV;
	attach_v_midi(&cfg);

	return 0;
}

static void __exit cleanup_vmidi(void)
{
	unload_v_midi(&cfg);
}

module_init(init_vmidi);
module_exit(cleanup_vmidi);
MODULE_LICENSE("GPL");