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         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(struct seq_oss_readq *q, int dev, unsigned char *data, int len)
 103 {
 104         union evrec 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  * put MIDI sysex bytes; the event buffer may be chained, thus it has
 122  * to be expanded via snd_seq_dump_var_event().
 123  */
 124 struct readq_sysex_ctx {
 125         struct seq_oss_readq *readq;
 126         int dev;
 127 };
 128
 129 static int readq_dump_sysex(void *ptr, void *buf, int count)
 130 {
 131         struct readq_sysex_ctx *ctx = ptr;
 132
 133         return snd_seq_oss_readq_puts(ctx->readq, ctx->dev, buf, count);
 134 }
 135
 136 int snd_seq_oss_readq_sysex(struct seq_oss_readq *q, int dev,
 137                             struct snd_seq_event *ev)
 138 {
 139         struct readq_sysex_ctx ctx = {
 140                 .readq = q,
 141                 .dev = dev
 142         };
 143
 144         if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
 145                 return 0;
 146         return snd_seq_dump_var_event(ev, readq_dump_sysex, &ctx);
 147 }
 148
 149 /*
 150  * copy an event to input queue:
 151  * return zero if enqueued
 152  */
 153 int
 154 snd_seq_oss_readq_put_event(struct seq_oss_readq *q, union evrec *ev)
 155 {
 156         unsigned long flags;
 157
 158         spin_lock_irqsave(&q->lock, flags);
 159         if (q->qlen >= q->maxlen - 1) {
 160                 spin_unlock_irqrestore(&q->lock, flags);
 161                 return -ENOMEM;
 162         }
 163
 164         memcpy(&q->q[q->tail], ev, sizeof(*ev));
 165         q->tail = (q->tail + 1) % q->maxlen;
 166         q->qlen++;
 167
 168         /* wake up sleeper */
 169         wake_up(&q->midi_sleep);
 170
 171         spin_unlock_irqrestore(&q->lock, flags);
 172
 173         return 0;
 174 }
 175
 176
 177 /*
 178  * pop queue
 179  * caller must hold lock
 180  */
 181 int
 182 snd_seq_oss_readq_pick(struct seq_oss_readq *q, union evrec *rec)
 183 {
 184         if (q->qlen == 0)
 185                 return -EAGAIN;
 186         memcpy(rec, &q->q[q->head], sizeof(*rec));
 187         return 0;
 188 }
 189
 190 /*
 191  * sleep until ready
 192  */
 193 void
 194 snd_seq_oss_readq_wait(struct seq_oss_readq *q)
 195 {
 196         wait_event_interruptible_timeout(q->midi_sleep,
 197                                          (q->qlen > 0 || q->head == q->tail),
 198                                          q->pre_event_timeout);
 199 }
 200
 201 /*
 202  * drain one record
 203  * caller must hold lock
 204  */
 205 void
 206 snd_seq_oss_readq_free(struct seq_oss_readq *q)
 207 {
 208         if (q->qlen > 0) {
 209                 q->head = (q->head + 1) % q->maxlen;
 210                 q->qlen--;
 211         }
 212 }
 213
 214 /*
 215  * polling/select:
 216  * return non-zero if readq is not empty.
 217  */
 218 unsigned int
 219 snd_seq_oss_readq_poll(struct seq_oss_readq *q, struct file *file, poll_table *wait)
 220 {
 221         poll_wait(file, &q->midi_sleep, wait);
 222         return q->qlen;
 223 }
 224
 225 /*
 226  * put a timestamp
 227  */
 228 int
 229 snd_seq_oss_readq_put_timestamp(struct seq_oss_readq *q, unsigned long curt, int seq_mode)
 230 {
 231         if (curt != q->input_time) {
 232                 union evrec rec;
 233                 memset(&rec, 0, sizeof(rec));
 234                 switch (seq_mode) {
 235                 case SNDRV_SEQ_OSS_MODE_SYNTH:
 236                         rec.echo = (curt << 8) | SEQ_WAIT;
 237                         snd_seq_oss_readq_put_event(q, &rec);
 238                         break;
 239                 case SNDRV_SEQ_OSS_MODE_MUSIC:
 240                         rec.t.code = EV_TIMING;
 241                         rec.t.cmd = TMR_WAIT_ABS;
 242                         rec.t.time = curt;
 243                         snd_seq_oss_readq_put_event(q, &rec);
 244                         break;
 245                 }
 246                 q->input_time = curt;
 247         }
 248         return 0;
 249 }
 250
 251
 252 #ifdef CONFIG_SND_PROC_FS
 253 /*
 254  * proc interface
 255  */
 256 void
 257 snd_seq_oss_readq_info_read(struct seq_oss_readq *q, struct snd_info_buffer *buf)
 258 {
 259         snd_iprintf(buf, "  read queue [%s] length = %d : tick = %ld\n",
 260                     (waitqueue_active(&q->midi_sleep) ? "sleeping":"running"),
 261                     q->qlen, q->input_time);
 262 }
 263 #endif /* CONFIG_SND_PROC_FS */