1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * OSS compatible sequencer driver
4 *
5 * read/write/select interface to device file
6 *
7 * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
8 */
9
10#include "seq_oss_device.h"
11#include "seq_oss_readq.h"
12#include "seq_oss_writeq.h"
13#include "seq_oss_synth.h"
14#include <sound/seq_oss_legacy.h>
15#include "seq_oss_event.h"
16#include "seq_oss_timer.h"
17#include "../seq_clientmgr.h"
18
19
20/*
21 * protoypes
22 */
23static int insert_queue(struct seq_oss_devinfo *dp, union evrec *rec, struct file *opt);
24
25
26/*
27 * read interface
28 */
29
30int
31snd_seq_oss_read(struct seq_oss_devinfo *dp, char __user *buf, int count)
32{
33 struct seq_oss_readq *readq = dp->readq;
34 int result = 0, err = 0;
35 int ev_len;
36 union evrec rec;
37 unsigned long flags;
38
39 if (readq == NULL || ! is_read_mode(dp->file_mode))
40 return -ENXIO;
41
42 while (count >= SHORT_EVENT_SIZE) {
43 snd_seq_oss_readq_lock(readq, flags);
44 err = snd_seq_oss_readq_pick(q: readq, rec: &rec);
45 if (err == -EAGAIN &&
46 !is_nonblock_mode(dp->file_mode) && result == 0) {
47 snd_seq_oss_readq_unlock(readq, flags);
48 snd_seq_oss_readq_wait(q: readq);
49 snd_seq_oss_readq_lock(readq, flags);
50 if (signal_pending(current))
51 err = -ERESTARTSYS;
52 else
53 err = snd_seq_oss_readq_pick(q: readq, rec: &rec);
54 }
55 if (err < 0) {
56 snd_seq_oss_readq_unlock(readq, flags);
57 break;
58 }
59 ev_len = ev_length(&rec);
60 if (ev_len < count) {
61 snd_seq_oss_readq_unlock(readq, flags);
62 break;
63 }
64 snd_seq_oss_readq_free(q: readq);
65 snd_seq_oss_readq_unlock(readq, flags);
66 if (copy_to_user(to: buf, from: &rec, n: ev_len)) {
67 err = -EFAULT;
68 break;
69 }
70 result += ev_len;
71 buf += ev_len;
72 count -= ev_len;
73 }
74 return result > 0 ? result : err;
75}
76
77
78/*
79 * write interface
80 */
81
82int
83snd_seq_oss_write(struct seq_oss_devinfo *dp, const char __user *buf, int count, struct file *opt)
84{
85 int result = 0, err = 0;
86 int ev_size, fmt;
87 union evrec rec;
88
89 if (! is_write_mode(dp->file_mode) || dp->writeq == NULL)
90 return -ENXIO;
91
92 while (count >= SHORT_EVENT_SIZE) {
93 if (copy_from_user(to: &rec, from: buf, SHORT_EVENT_SIZE)) {
94 err = -EFAULT;
95 break;
96 }
97 if (rec.s.code == SEQ_FULLSIZE) {
98 /* load patch */
99 if (result > 0) {
100 err = -EINVAL;
101 break;
102 }
103 fmt = (*(unsigned short *)rec.c) & 0xffff;
104 /* FIXME the return value isn't correct */
105 return snd_seq_oss_synth_load_patch(dp, dev: rec.s.dev,
106 fmt, buf, p: 0, c: count);
107 }
108 if (ev_is_long(&rec)) {
109 /* extended code */
110 if (rec.s.code == SEQ_EXTENDED &&
111 dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC) {
112 err = -EINVAL;
113 break;
114 }
115 ev_size = LONG_EVENT_SIZE;
116 if (count < ev_size)
117 break;
118 /* copy the reset 4 bytes */
119 if (copy_from_user(to: rec.c + SHORT_EVENT_SIZE,
120 from: buf + SHORT_EVENT_SIZE,
121 LONG_EVENT_SIZE - SHORT_EVENT_SIZE)) {
122 err = -EFAULT;
123 break;
124 }
125 } else {
126 /* old-type code */
127 if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC) {
128 err = -EINVAL;
129 break;
130 }
131 ev_size = SHORT_EVENT_SIZE;
132 }
133
134 /* insert queue */
135 err = insert_queue(dp, rec: &rec, opt);
136 if (err < 0)
137 break;
138
139 result += ev_size;
140 buf += ev_size;
141 count -= ev_size;
142 }
143 return result > 0 ? result : err;
144}
145
146
147/*
148 * insert event record to write queue
149 * return: 0 = OK, non-zero = NG
150 */
151static int
152insert_queue(struct seq_oss_devinfo *dp, union evrec *rec, struct file *opt)
153{
154 int rc = 0;
155 struct snd_seq_event event;
156
157 /* if this is a timing event, process the current time */
158 if (snd_seq_oss_process_timer_event(rec: dp->timer, q: rec))
159 return 0; /* no need to insert queue */
160
161 /* parse this event */
162 memset(&event, 0, sizeof(event));
163 /* set dummy -- to be sure */
164 event.type = SNDRV_SEQ_EVENT_NOTEOFF;
165 snd_seq_oss_fill_addr(dp, ev: &event, dest_client: dp->addr.client, dest_port: dp->addr.port);
166
167 if (snd_seq_oss_process_event(dp, q: rec, ev: &event))
168 return 0; /* invalid event - no need to insert queue */
169
170 event.time.tick = snd_seq_oss_timer_cur_tick(timer: dp->timer);
171 if (dp->timer->realtime || !dp->timer->running)
172 snd_seq_oss_dispatch(dp, ev: &event, atomic: 0, hop: 0);
173 else
174 rc = snd_seq_kernel_client_enqueue(client: dp->cseq, ev: &event, file: opt,
175 blocking: !is_nonblock_mode(dp->file_mode));
176 return rc;
177}
178
179
180/*
181 * select / poll
182 */
183
184__poll_t
185snd_seq_oss_poll(struct seq_oss_devinfo *dp, struct file *file, poll_table * wait)
186{
187 __poll_t mask = 0;
188
189 /* input */
190 if (dp->readq && is_read_mode(dp->file_mode)) {
191 if (snd_seq_oss_readq_poll(readq: dp->readq, file, wait))
192 mask |= EPOLLIN | EPOLLRDNORM;
193 }
194
195 /* output */
196 if (dp->writeq && is_write_mode(dp->file_mode)) {
197 if (snd_seq_kernel_client_write_poll(clientid: dp->cseq, file, wait))
198 mask |= EPOLLOUT | EPOLLWRNORM;
199 }
200 return mask;
201}
202

source code of linux/sound/core/seq/oss/seq_oss_rw.c