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(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
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(&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 */
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(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
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(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