// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * OSS compatible sequencer driver
 *
 * read/write/select interface to device file
 *
 * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
 */

#include "seq_oss_device.h"
#include "seq_oss_readq.h"
#include "seq_oss_writeq.h"
#include "seq_oss_synth.h"
#include <sound/seq_oss_legacy.h>
#include "seq_oss_event.h"
#include "seq_oss_timer.h"
#include "../seq_clientmgr.h"


/*
 * protoypes
 */
static int insert_queue(struct seq_oss_devinfo *dp, union evrec *rec, struct file *opt);


/*
 * read interface
 */

int
snd_seq_oss_read(struct seq_oss_devinfo *dp, char __user *buf, int count)
{
        struct seq_oss_readq *readq = dp->readq;
        int result = 0, err = 0;
        int ev_len;
        union evrec rec;
        unsigned long flags;

        if (readq == NULL || ! is_read_mode(dp->file_mode))
                return -ENXIO;

        while (count >= SHORT_EVENT_SIZE) {
                snd_seq_oss_readq_lock(readq, flags);
                err = snd_seq_oss_readq_pick(readq, &rec);
                if (err == -EAGAIN &&
                    !is_nonblock_mode(dp->file_mode) && result == 0) {
                        snd_seq_oss_readq_unlock(readq, flags);
                        snd_seq_oss_readq_wait(readq);
                        snd_seq_oss_readq_lock(readq, flags);
                        if (signal_pending(current))
                                err = -ERESTARTSYS;
                        else
                                err = snd_seq_oss_readq_pick(readq, &rec);
                }
                if (err < 0) {
                        snd_seq_oss_readq_unlock(readq, flags);
                        break;
                }
                ev_len = ev_length(&rec);
                if (ev_len < count) {
                        snd_seq_oss_readq_unlock(readq, flags);
                        break;
                }
                snd_seq_oss_readq_free(readq);
                snd_seq_oss_readq_unlock(readq, flags);
                if (copy_to_user(buf, &rec, ev_len)) {
                        err = -EFAULT;
                        break;
                }
                result += ev_len;
                buf += ev_len;
                count -= ev_len;
        }
        return result > 0 ? result : err;
}


/*
 * write interface
 */

int
snd_seq_oss_write(struct seq_oss_devinfo *dp, const char __user *buf, int count, struct file *opt)
{
        int result = 0, err = 0;
        int ev_size, fmt;
        union evrec rec;

        if (! is_write_mode(dp->file_mode) || dp->writeq == NULL)
                return -ENXIO;

        while (count >= SHORT_EVENT_SIZE) {
                if (copy_from_user(&rec, buf, SHORT_EVENT_SIZE)) {
                        err = -EFAULT;
                        break;
                }
                if (rec.s.code == SEQ_FULLSIZE) {
                        /* load patch */
                        if (result > 0) {
                                err = -EINVAL;
                                break;
                        }
                        fmt = (*(unsigned short *)rec.c) & 0xffff;
                        /* FIXME the return value isn't correct */
                        return snd_seq_oss_synth_load_patch(dp, rec.s.dev,
                                                            fmt, buf, 0, count);
                }
                if (ev_is_long(&rec)) {
                        /* extended code */
                        if (rec.s.code == SEQ_EXTENDED &&
                            dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC) {
                                err = -EINVAL;
                                break;
                        }
                        ev_size = LONG_EVENT_SIZE;
                        if (count < ev_size)
                                break;
                        /* copy the reset 4 bytes */
                        if (copy_from_user(rec.c + SHORT_EVENT_SIZE,
                                           buf + SHORT_EVENT_SIZE,
                                           LONG_EVENT_SIZE - SHORT_EVENT_SIZE)) {
                                err = -EFAULT;
                                break;
                        }
                } else {
                        /* old-type code */
                        if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC) {
                                err = -EINVAL;
                                break;
                        }
                        ev_size = SHORT_EVENT_SIZE;
                }

                /* insert queue */
                err = insert_queue(dp, &rec, opt);
                if (err < 0)
                        break;

                result += ev_size;
                buf += ev_size;
                count -= ev_size;
        }
        return result > 0 ? result : err;
}


/*
 * insert event record to write queue
 * return: 0 = OK, non-zero = NG
 */
static int
insert_queue(struct seq_oss_devinfo *dp, union evrec *rec, struct file *opt)
{
        int rc = 0;
        struct snd_seq_event event;

        /* if this is a timing event, process the current time */
        if (snd_seq_oss_process_timer_event(dp->timer, rec))
                return 0; /* no need to insert queue */

        /* parse this event */
        memset(&event, 0, sizeof(event));
        /* set dummy -- to be sure */
        event.type = SNDRV_SEQ_EVENT_NOTEOFF;
        snd_seq_oss_fill_addr(dp, &event, dp->addr.client, dp->addr.port);

        if (snd_seq_oss_process_event(dp, rec, &event))
                return 0; /* invalid event - no need to insert queue */

        event.time.tick = snd_seq_oss_timer_cur_tick(dp->timer);
        if (dp->timer->realtime || !dp->timer->running)
                snd_seq_oss_dispatch(dp, &event, 0, 0);
        else
                rc = snd_seq_kernel_client_enqueue(dp->cseq, &event, opt,
                                                   !is_nonblock_mode(dp->file_mode));
        return rc;
}
                

/*
 * select / poll
 */
  
__poll_t
snd_seq_oss_poll(struct seq_oss_devinfo *dp, struct file *file, poll_table * wait)
{
        __poll_t mask = 0;

        /* input */
        if (dp->readq && is_read_mode(dp->file_mode)) {
                if (snd_seq_oss_readq_poll(dp->readq, file, wait))
                        mask |= EPOLLIN | EPOLLRDNORM;
        }

        /* output */
        if (dp->writeq && is_write_mode(dp->file_mode)) {
                if (snd_seq_kernel_client_write_poll(dp->cseq, file, wait))
                        mask |= EPOLLOUT | EPOLLWRNORM;
        }
        return mask;
}