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_writeq.c - write queue and sync
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_writeq.h"
24#include "seq_oss_event.h"
25#include "seq_oss_timer.h"
26#include <sound/seq_oss_legacy.h>
27#include "../seq_lock.h"
28#include "../seq_clientmgr.h"
29#include <linux/wait.h>
30
31
32/*
33 * create a write queue record
34 */
35struct seq_oss_writeq *
36snd_seq_oss_writeq_new(struct seq_oss_devinfo *dp, int maxlen)
37{
38 struct seq_oss_writeq *q;
39 struct snd_seq_client_pool pool;
40
41 if ((q = kzalloc(sizeof(*q), GFP_KERNEL)) == NULL)
42 return NULL;
43 q->dp = dp;
44 q->maxlen = maxlen;
45 spin_lock_init(&q->sync_lock);
46 q->sync_event_put = 0;
47 q->sync_time = 0;
48 init_waitqueue_head(&q->sync_sleep);
49
50 memset(&pool, 0, sizeof(pool));
51 pool.client = dp->cseq;
52 pool.output_pool = maxlen;
53 pool.output_room = maxlen / 2;
54
55 snd_seq_oss_control(dp, SNDRV_SEQ_IOCTL_SET_CLIENT_POOL, &pool);
56
57 return q;
58}
59
60/*
61 * delete the write queue
62 */
63void
64snd_seq_oss_writeq_delete(struct seq_oss_writeq *q)
65{
66 if (q) {
67 snd_seq_oss_writeq_clear(q); /* to be sure */
68 kfree(q);
69 }
70}
71
72
73/*
74 * reset the write queue
75 */
76void
77snd_seq_oss_writeq_clear(struct seq_oss_writeq *q)
78{
79 struct snd_seq_remove_events reset;
80
81 memset(&reset, 0, sizeof(reset));
82 reset.remove_mode = SNDRV_SEQ_REMOVE_OUTPUT; /* remove all */
83 snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_REMOVE_EVENTS, &reset);
84
85 /* wake up sleepers if any */
86 snd_seq_oss_writeq_wakeup(q, 0);
87}
88
89/*
90 * wait until the write buffer has enough room
91 */
92int
93snd_seq_oss_writeq_sync(struct seq_oss_writeq *q)
94{
95 struct seq_oss_devinfo *dp = q->dp;
96 abstime_t time;
97
98 time = snd_seq_oss_timer_cur_tick(dp->timer);
99 if (q->sync_time >= time)
100 return 0; /* already finished */
101
102 if (! q->sync_event_put) {
103 struct snd_seq_event ev;
104 union evrec *rec;
105
106 /* put echoback event */
107 memset(&ev, 0, sizeof(ev));
108 ev.flags = 0;
109 ev.type = SNDRV_SEQ_EVENT_ECHO;
110 ev.time.tick = time;
111 /* echo back to itself */
112 snd_seq_oss_fill_addr(dp, &ev, dp->addr.client, dp->addr.port);
113 rec = (union evrec *)&ev.data;
114 rec->t.code = SEQ_SYNCTIMER;
115 rec->t.time = time;
116 q->sync_event_put = 1;
117 snd_seq_kernel_client_enqueue_blocking(dp->cseq, &ev, NULL, 0, 0);
118 }
119
120 wait_event_interruptible_timeout(q->sync_sleep, ! q->sync_event_put, HZ);
121 if (signal_pending(current))
122 /* interrupted - return 0 to finish sync */
123 q->sync_event_put = 0;
124 if (! q->sync_event_put || q->sync_time >= time)
125 return 0;
126 return 1;
127}
128
129/*
130 * wake up sync - echo event was catched
131 */
132void
133snd_seq_oss_writeq_wakeup(struct seq_oss_writeq *q, abstime_t time)
134{
135 unsigned long flags;
136
137 spin_lock_irqsave(&q->sync_lock, flags);
138 q->sync_time = time;
139 q->sync_event_put = 0;
140 if (waitqueue_active(&q->sync_sleep)) {
141 wake_up(&q->sync_sleep);
142 }
143 spin_unlock_irqrestore(&q->sync_lock, flags);
144}
145
146
147/*
148 * return the unused pool size
149 */
150int
151snd_seq_oss_writeq_get_free_size(struct seq_oss_writeq *q)
152{
153 struct snd_seq_client_pool pool;
154 pool.client = q->dp->cseq;
155 snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, &pool);
156 return pool.output_free;
157}
158
159
160/*
161 * set output threshold size from ioctl
162 */
163void
164snd_seq_oss_writeq_set_output(struct seq_oss_writeq *q, int val)
165{
166 struct snd_seq_client_pool pool;
167 pool.client = q->dp->cseq;
168 snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, &pool);
169 pool.output_room = val;
170 snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_SET_CLIENT_POOL, &pool);
171}
172