xref: /openbmc/linux/sound/core/seq/oss/seq_oss_rw.c (revision f9a6bb84)
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  */
23 static int insert_queue(struct seq_oss_devinfo *dp, union evrec *rec, struct file *opt);
24 
25 
26 /*
27  * read interface
28  */
29 
30 int
snd_seq_oss_read(struct seq_oss_devinfo * dp,char __user * buf,int count)31 snd_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(readq, &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(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(readq, &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(readq);
65 		snd_seq_oss_readq_unlock(readq, flags);
66 		if (copy_to_user(buf, &rec, 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 
82 int
snd_seq_oss_write(struct seq_oss_devinfo * dp,const char __user * buf,int count,struct file * opt)83 snd_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(&rec, 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, rec.s.dev,
106 							    fmt, buf, 0, 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(rec.c + SHORT_EVENT_SIZE,
120 					   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, 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  */
151 static int
insert_queue(struct seq_oss_devinfo * dp,union evrec * rec,struct file * opt)152 insert_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(dp->timer, 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, &event, dp->addr.client, dp->addr.port);
166 
167 	if (snd_seq_oss_process_event(dp, rec, &event))
168 		return 0; /* invalid event - no need to insert queue */
169 
170 	event.time.tick = snd_seq_oss_timer_cur_tick(dp->timer);
171 	if (dp->timer->realtime || !dp->timer->running)
172 		snd_seq_oss_dispatch(dp, &event, 0, 0);
173 	else
174 		rc = snd_seq_kernel_client_enqueue(dp->cseq, &event, opt,
175 						   !is_nonblock_mode(dp->file_mode));
176 	return rc;
177 }
178 
179 
180 /*
181  * select / poll
182  */
183 
184 __poll_t
snd_seq_oss_poll(struct seq_oss_devinfo * dp,struct file * file,poll_table * wait)185 snd_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(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(dp->cseq, file, wait))
198 			mask |= EPOLLOUT | EPOLLWRNORM;
199 	}
200 	return mask;
201 }
202