seq_oss_rw.c

  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}