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seq_oss_rw.c

/*
 * OSS compatible sequencer driver
 *
 * read/write/select interface to device file
 *
 * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#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(seq_oss_devinfo_t *dp, evrec_t *rec, struct file *opt);


/*
 * read interface
 */

int
snd_seq_oss_read(seq_oss_devinfo_t *dp, char __user *buf, int count)
{
      seq_oss_readq_t *readq = dp->readq;
      int result = 0, err = 0;
      int ev_len;
      evrec_t 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(seq_oss_devinfo_t *dp, const char __user *buf, int count, struct file *opt)
{
      int result = 0, err = 0;
      int ev_size, fmt;
      evrec_t 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 */
            if ((err = insert_queue(dp, &rec, opt)) < 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(seq_oss_devinfo_t *dp, evrec_t *rec, struct file *opt)
{
      int rc = 0;
      snd_seq_event_t 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.port, dp->addr.client);

      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 {
            if (is_nonblock_mode(dp->file_mode))
                  rc = snd_seq_kernel_client_enqueue(dp->cseq, &event, 0, 0);
            else
                  rc = snd_seq_kernel_client_enqueue_blocking(dp->cseq, &event, opt, 0, 0);
      }
      return rc;
}
            

/*
 * select / poll
 */
  
unsigned int
snd_seq_oss_poll(seq_oss_devinfo_t *dp, struct file *file, poll_table * wait)
{
      unsigned int mask = 0;

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

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

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