tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * OSS compatible sequencer driver
3 *
4 * seq_oss_readq.c - MIDI input queue
5 *
6 * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23#include "seq_oss_readq.h"
24#include "seq_oss_event.h"
25#include <sound/seq_oss_legacy.h>
26#include "../seq_lock.h"
27#include <linux/wait.h>
28#include <linux/slab.h>
29
30/*
31 * constants
32 */
33//#define SNDRV_SEQ_OSS_MAX_TIMEOUT (unsigned long)(-1)
34#define SNDRV_SEQ_OSS_MAX_TIMEOUT (HZ * 3600)
35
36
37/*
38 * prototypes
39 */
40
41
42/*
43 * create a read queue
44 */
45struct seq_oss_readq *
46snd_seq_oss_readq_new(struct seq_oss_devinfo *dp, int maxlen)
47{
48 struct seq_oss_readq *q;
49
50 q = kzalloc(sizeof(*q), GFP_KERNEL);
51 if (!q)
52 return NULL;
53
54 q->q = kcalloc(maxlen, sizeof(union evrec), GFP_KERNEL);
55 if (!q->q) {
56 kfree(q);
57 return NULL;
58 }
59
60 q->maxlen = maxlen;
61 q->qlen = 0;
62 q->head = q->tail = 0;
63 init_waitqueue_head(&q->midi_sleep);
64 spin_lock_init(&q->lock);
65 q->pre_event_timeout = SNDRV_SEQ_OSS_MAX_TIMEOUT;
66 q->input_time = (unsigned long)-1;
67
68 return q;
69}
70
71/*
72 * delete the read queue
73 */
74void
75snd_seq_oss_readq_delete(struct seq_oss_readq *q)
76{
77 if (q) {
78 kfree(q->q);
79 kfree(q);
80 }
81}
82
83/*
84 * reset the read queue
85 */
86void
87snd_seq_oss_readq_clear(struct seq_oss_readq *q)
88{
89 if (q->qlen) {
90 q->qlen = 0;
91 q->head = q->tail = 0;
92 }
93 /* if someone sleeping, wake'em up */
94 wake_up(&q->midi_sleep);
95 q->input_time = (unsigned long)-1;
96}
97
98/*
99 * put a midi byte
100 */
101int
102snd_seq_oss_readq_puts(struct seq_oss_readq *q, int dev, unsigned char *data, int len)
103{
104 union evrec rec;
105 int result;
106
107 memset(&rec, 0, sizeof(rec));
108 rec.c[0] = SEQ_MIDIPUTC;
109 rec.c[2] = dev;
110
111 while (len-- > 0) {
112 rec.c[1] = *data++;
113 result = snd_seq_oss_readq_put_event(q, &rec);
114 if (result < 0)
115 return result;
116 }
117 return 0;
118}
119
120/*
121 * copy an event to input queue:
122 * return zero if enqueued
123 */
124int
125snd_seq_oss_readq_put_event(struct seq_oss_readq *q, union evrec *ev)
126{
127 unsigned long flags;
128
129 spin_lock_irqsave(&q->lock, flags);
130 if (q->qlen >= q->maxlen - 1) {
131 spin_unlock_irqrestore(&q->lock, flags);
132 return -ENOMEM;
133 }
134
135 memcpy(&q->q[q->tail], ev, sizeof(*ev));
136 q->tail = (q->tail + 1) % q->maxlen;
137 q->qlen++;
138
139 /* wake up sleeper */
140 wake_up(&q->midi_sleep);
141
142 spin_unlock_irqrestore(&q->lock, flags);
143
144 return 0;
145}
146
147
148/*
149 * pop queue
150 * caller must hold lock
151 */
152int
153snd_seq_oss_readq_pick(struct seq_oss_readq *q, union evrec *rec)
154{
155 if (q->qlen == 0)
156 return -EAGAIN;
157 memcpy(rec, &q->q[q->head], sizeof(*rec));
158 return 0;
159}
160
161/*
162 * sleep until ready
163 */
164void
165snd_seq_oss_readq_wait(struct seq_oss_readq *q)
166{
167 wait_event_interruptible_timeout(q->midi_sleep,
168 (q->qlen > 0 || q->head == q->tail),
169 q->pre_event_timeout);
170}
171
172/*
173 * drain one record
174 * caller must hold lock
175 */
176void
177snd_seq_oss_readq_free(struct seq_oss_readq *q)
178{
179 if (q->qlen > 0) {
180 q->head = (q->head + 1) % q->maxlen;
181 q->qlen--;
182 }
183}
184
185/*
186 * polling/select:
187 * return non-zero if readq is not empty.
188 */
189unsigned int
190snd_seq_oss_readq_poll(struct seq_oss_readq *q, struct file *file, poll_table *wait)
191{
192 poll_wait(file, &q->midi_sleep, wait);
193 return q->qlen;
194}
195
196/*
197 * put a timestamp
198 */
199int
200snd_seq_oss_readq_put_timestamp(struct seq_oss_readq *q, unsigned long curt, int seq_mode)
201{
202 if (curt != q->input_time) {
203 union evrec rec;
204 memset(&rec, 0, sizeof(rec));
205 switch (seq_mode) {
206 case SNDRV_SEQ_OSS_MODE_SYNTH:
207 rec.echo = (curt << 8) | SEQ_WAIT;
208 snd_seq_oss_readq_put_event(q, &rec);
209 break;
210 case SNDRV_SEQ_OSS_MODE_MUSIC:
211 rec.t.code = EV_TIMING;
212 rec.t.cmd = TMR_WAIT_ABS;
213 rec.t.time = curt;
214 snd_seq_oss_readq_put_event(q, &rec);
215 break;
216 }
217 q->input_time = curt;
218 }
219 return 0;
220}
221
222
223#ifdef CONFIG_SND_PROC_FS
224/*
225 * proc interface
226 */
227void
228snd_seq_oss_readq_info_read(struct seq_oss_readq *q, struct snd_info_buffer *buf)
229{
230 snd_iprintf(buf, " read queue [%s] length = %d : tick = %ld\n",
231 (waitqueue_active(&q->midi_sleep) ? "sleeping":"running"),
232 q->qlen, q->input_time);
233}
234#endif /* CONFIG_SND_PROC_FS */