sound/core/seq/oss/seq_oss_readq.c

   1 /*
   2  * OSS compatible sequencer driver
   3  *
   4  * seq_oss_readq.c - MIDI input queue
   5  *
   6  * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  21  */
  22
  23 #include "seq_oss_readq.h"
  24 #include "seq_oss_event.h"
  25 #include <sound/seq_oss_legacy.h>
  26 #include "../seq_lock.h"
  27
  28 /*
  29  * constants
  30  */
  31 //#define SNDRV_SEQ_OSS_MAX_TIMEOUT     (unsigned long)(-1)
  32 #define SNDRV_SEQ_OSS_MAX_TIMEOUT       (HZ * 3600)
  33
  34
  35 /*
  36  * prototypes
  37  */
  38
  39
  40 /*
  41  * create a read queue
  42  */
  43 seq_oss_readq_t *
  44 snd_seq_oss_readq_new(seq_oss_devinfo_t *dp, int maxlen)
  45 {
  46         seq_oss_readq_t *q;
  47
  48         if ((q = kcalloc(1, sizeof(*q), GFP_KERNEL)) == NULL) {
  49                 snd_printk(KERN_ERR "can't malloc read queue\n");
  50                 return NULL;
  51         }
  52
  53         if ((q->q = kcalloc(maxlen, sizeof(evrec_t), GFP_KERNEL)) == NULL) {
  54                 snd_printk(KERN_ERR "can't malloc read queue buffer\n");
  55                 kfree(q);
  56                 return NULL;
  57         }
  58
  59         q->maxlen = maxlen;
  60         q->qlen = 0;
  61         q->head = q->tail = 0;
  62         init_waitqueue_head(&q->midi_sleep);
  63         spin_lock_init(&q->lock);
  64         q->pre_event_timeout = SNDRV_SEQ_OSS_MAX_TIMEOUT;
  65         q->input_time = (unsigned long)-1;
  66
  67         return q;
  68 }
  69
  70 /*
  71  * delete the read queue
  72  */
  73 void
  74 snd_seq_oss_readq_delete(seq_oss_readq_t *q)
  75 {
  76         if (q) {
  77                 kfree(q->q);
  78                 kfree(q);
  79         }
  80 }
  81
  82 /*
  83  * reset the read queue
  84  */
  85 void
  86 snd_seq_oss_readq_clear(seq_oss_readq_t *q)
  87 {
  88         if (q->qlen) {
  89                 q->qlen = 0;
  90                 q->head = q->tail = 0;
  91         }
  92         /* if someone sleeping, wake'em up */
  93         if (waitqueue_active(&q->midi_sleep))
  94                 wake_up(&q->midi_sleep);
  95         q->input_time = (unsigned long)-1;
  96 }
  97
  98 /*
  99  * put a midi byte
 100  */
 101 int
 102 snd_seq_oss_readq_puts(seq_oss_readq_t *q, int dev, unsigned char *data, int len)
 103 {
 104         evrec_t rec;
 105         int result;
 106
 107         memset(&rec, 0, sizeof(rec));
 108         rec.c[0] = SEQ_MIDIPUTC;
 109         rec.c[2] = dev;
 110
 111         while (len-- > 0) {
 112                 rec.c[1] = *data++;
 113                 result = snd_seq_oss_readq_put_event(q, &rec);
 114                 if (result < 0)
 115                         return result;
 116         }
 117         return 0;
 118 }
 119
 120 /*
 121  * copy an event to input queue:
 122  * return zero if enqueued
 123  */
 124 int
 125 snd_seq_oss_readq_put_event(seq_oss_readq_t *q, evrec_t *ev)
 126 {
 127         unsigned long flags;
 128
 129         spin_lock_irqsave(&q->lock, flags);
 130         if (q->qlen >= q->maxlen - 1) {
 131                 spin_unlock_irqrestore(&q->lock, flags);
 132                 return -ENOMEM;
 133         }
 134
 135         memcpy(&q->q[q->tail], ev, sizeof(*ev));
 136         q->tail = (q->tail + 1) % q->maxlen;
 137         q->qlen++;
 138
 139         /* wake up sleeper */
 140         if (waitqueue_active(&q->midi_sleep))
 141                 wake_up(&q->midi_sleep);
 142
 143         spin_unlock_irqrestore(&q->lock, flags);
 144
 145         return 0;
 146 }
 147
 148
 149 /*
 150  * pop queue
 151  * caller must hold lock
 152  */
 153 int
 154 snd_seq_oss_readq_pick(seq_oss_readq_t *q, evrec_t *rec)
 155 {
 156         if (q->qlen == 0)
 157                 return -EAGAIN;
 158         memcpy(rec, &q->q[q->head], sizeof(*rec));
 159         return 0;
 160 }
 161
 162 /*
 163  * sleep until ready
 164  */
 165 void
 166 snd_seq_oss_readq_wait(seq_oss_readq_t *q)
 167 {
 168         interruptible_sleep_on_timeout(&q->midi_sleep, q->pre_event_timeout);
 169 }
 170
 171 /*
 172  * drain one record
 173  * caller must hold lock
 174  */
 175 void
 176 snd_seq_oss_readq_free(seq_oss_readq_t *q)
 177 {
 178         if (q->qlen > 0) {
 179                 q->head = (q->head + 1) % q->maxlen;
 180                 q->qlen--;
 181         }
 182 }
 183
 184 /*
 185  * polling/select:
 186  * return non-zero if readq is not empty.
 187  */
 188 unsigned int
 189 snd_seq_oss_readq_poll(seq_oss_readq_t *q, struct file *file, poll_table *wait)
 190 {
 191         poll_wait(file, &q->midi_sleep, wait);
 192         return q->qlen;
 193 }
 194
 195 /*
 196  * put a timestamp
 197  */
 198 int
 199 snd_seq_oss_readq_put_timestamp(seq_oss_readq_t *q, unsigned long curt, int seq_mode)
 200 {
 201         if (curt != q->input_time) {
 202                 evrec_t rec;
 203                 memset(&rec, 0, sizeof(rec));
 204                 switch (seq_mode) {
 205                 case SNDRV_SEQ_OSS_MODE_SYNTH:
 206                         rec.echo = (curt << 8) | SEQ_WAIT;
 207                         snd_seq_oss_readq_put_event(q, &rec);
 208                         break;
 209                 case SNDRV_SEQ_OSS_MODE_MUSIC:
 210                         rec.t.code = EV_TIMING;
 211                         rec.t.cmd = TMR_WAIT_ABS;
 212                         rec.t.time = curt;
 213                         snd_seq_oss_readq_put_event(q, &rec);
 214                         break;
 215                 }
 216                 q->input_time = curt;
 217         }
 218         return 0;
 219 }
 220
 221
 222 /*
 223  * proc interface
 224  */
 225 void
 226 snd_seq_oss_readq_info_read(seq_oss_readq_t *q, snd_info_buffer_t *buf)
 227 {
 228         snd_iprintf(buf, "  read queue [%s] length = %d : tick = %ld\n",
 229                     (waitqueue_active(&q->midi_sleep) ? "sleeping":"running"),
 230                     q->qlen, q->input_time);
 231 }