kernel/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 #include <linux/wait.h>
  28 #include <linux/slab.h>
  29
  30 /*
  31  * constants
  32  */
  33 //#define SNDRV_SEQ_OSS_MAX_TIMEOUT     (unsigned long)(-1)
  34 #define SNDRV_SEQ_OSS_MAX_TIMEOUT       (HZ * 3600)
  35
  36
  37 /*
  38  * prototypes
  39  */
  40
  41
  42 /*
  43  * create a read queue
  44  */
  45 struct seq_oss_readq *
  46 snd_seq_oss_readq_new(struct seq_oss_devinfo *dp, int maxlen)
  47 {
  48         struct seq_oss_readq *q;
  49
  50         q = kzalloc(sizeof(*q), GFP_KERNEL);
  51         if (!q)
  52                 return NULL;
  53
  54         q->q = kcalloc(maxlen, sizeof(union evrec), GFP_KERNEL);
  55         if (!q->q) {
  56                 kfree(q);
  57                 return NULL;
  58         }
  59
  60         q->maxlen = maxlen;
  61         q->qlen = 0;
  62         q->head = q->tail = 0;
  63         init_waitqueue_head(&q->midi_sleep);
  64         spin_lock_init(&q->lock);
  65         q->pre_event_timeout = SNDRV_SEQ_OSS_MAX_TIMEOUT;
  66         q->input_time = (unsigned long)-1;
  67
  68         return q;
  69 }
  70
  71 /*
  72  * delete the read queue
  73  */
  74 void
  75 snd_seq_oss_readq_delete(struct seq_oss_readq *q)
  76 {
  77         if (q) {
  78                 kfree(q->q);
  79                 kfree(q);
  80         }
  81 }
  82
  83 /*
  84  * reset the read queue
  85  */
  86 void
  87 snd_seq_oss_readq_clear(struct seq_oss_readq *q)
  88 {
  89         if (q->qlen) {
  90                 q->qlen = 0;
  91                 q->head = q->tail = 0;
  92         }
  93         /* if someone sleeping, wake'em up */
  94         if (waitqueue_active(&q->midi_sleep))
  95                 wake_up(&q->midi_sleep);
  96         q->input_time = (unsigned long)-1;
  97 }
  98
  99 /*
 100  * put a midi byte
 101  */
 102 int
 103 snd_seq_oss_readq_puts(struct seq_oss_readq *q, int dev, unsigned char *data, int len)
 104 {
 105         union evrec rec;
 106         int result;
 107
 108         memset(&rec, 0, sizeof(rec));
 109         rec.c[0] = SEQ_MIDIPUTC;
 110         rec.c[2] = dev;
 111
 112         while (len-- > 0) {
 113                 rec.c[1] = *data++;
 114                 result = snd_seq_oss_readq_put_event(q, &rec);
 115                 if (result < 0)
 116                         return result;
 117         }
 118         return 0;
 119 }
 120
 121 /*
 122  * copy an event to input queue:
 123  * return zero if enqueued
 124  */
 125 int
 126 snd_seq_oss_readq_put_event(struct seq_oss_readq *q, union evrec *ev)
 127 {
 128         unsigned long flags;
 129
 130         spin_lock_irqsave(&q->lock, flags);
 131         if (q->qlen >= q->maxlen - 1) {
 132                 spin_unlock_irqrestore(&q->lock, flags);
 133                 return -ENOMEM;
 134         }
 135
 136         memcpy(&q->q[q->tail], ev, sizeof(*ev));
 137         q->tail = (q->tail + 1) % q->maxlen;
 138         q->qlen++;
 139
 140         /* wake up sleeper */
 141         if (waitqueue_active(&q->midi_sleep))
 142                 wake_up(&q->midi_sleep);
 143
 144         spin_unlock_irqrestore(&q->lock, flags);
 145
 146         return 0;
 147 }
 148
 149
 150 /*
 151  * pop queue
 152  * caller must hold lock
 153  */
 154 int
 155 snd_seq_oss_readq_pick(struct seq_oss_readq *q, union evrec *rec)
 156 {
 157         if (q->qlen == 0)
 158                 return -EAGAIN;
 159         memcpy(rec, &q->q[q->head], sizeof(*rec));
 160         return 0;
 161 }
 162
 163 /*
 164  * sleep until ready
 165  */
 166 void
 167 snd_seq_oss_readq_wait(struct seq_oss_readq *q)
 168 {
 169         wait_event_interruptible_timeout(q->midi_sleep,
 170                                          (q->qlen > 0 || q->head == q->tail),
 171                                          q->pre_event_timeout);
 172 }
 173
 174 /*
 175  * drain one record
 176  * caller must hold lock
 177  */
 178 void
 179 snd_seq_oss_readq_free(struct seq_oss_readq *q)
 180 {
 181         if (q->qlen > 0) {
 182                 q->head = (q->head + 1) % q->maxlen;
 183                 q->qlen--;
 184         }
 185 }
 186
 187 /*
 188  * polling/select:
 189  * return non-zero if readq is not empty.
 190  */
 191 unsigned int
 192 snd_seq_oss_readq_poll(struct seq_oss_readq *q, struct file *file, poll_table *wait)
 193 {
 194         poll_wait(file, &q->midi_sleep, wait);
 195         return q->qlen;
 196 }
 197
 198 /*
 199  * put a timestamp
 200  */
 201 int
 202 snd_seq_oss_readq_put_timestamp(struct seq_oss_readq *q, unsigned long curt, int seq_mode)
 203 {
 204         if (curt != q->input_time) {
 205                 union evrec rec;
 206                 memset(&rec, 0, sizeof(rec));
 207                 switch (seq_mode) {
 208                 case SNDRV_SEQ_OSS_MODE_SYNTH:
 209                         rec.echo = (curt << 8) | SEQ_WAIT;
 210                         snd_seq_oss_readq_put_event(q, &rec);
 211                         break;
 212                 case SNDRV_SEQ_OSS_MODE_MUSIC:
 213                         rec.t.code = EV_TIMING;
 214                         rec.t.cmd = TMR_WAIT_ABS;
 215                         rec.t.time = curt;
 216                         snd_seq_oss_readq_put_event(q, &rec);
 217                         break;
 218                 }
 219                 q->input_time = curt;
 220         }
 221         return 0;
 222 }
 223
 224
 225 #ifdef CONFIG_PROC_FS
 226 /*
 227  * proc interface
 228  */
 229 void
 230 snd_seq_oss_readq_info_read(struct seq_oss_readq *q, struct snd_info_buffer *buf)
 231 {
 232         snd_iprintf(buf, "  read queue [%s] length = %d : tick = %ld\n",
 233                     (waitqueue_active(&q->midi_sleep) ? "sleeping":"running"),
 234                     q->qlen, q->input_time);
 235 }
 236 #endif /* CONFIG_PROC_FS */