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         if ((q = kzalloc(sizeof(*q), GFP_KERNEL)) == NULL) {
  51                 pr_err("ALSA: seq_oss: can't malloc read queue\n");
  52                 return NULL;
  53         }
  54
  55         if ((q->q = kcalloc(maxlen, sizeof(union evrec), GFP_KERNEL)) == NULL) {
  56                 pr_err("ALSA: seq_oss: can't malloc read queue buffer\n");
  57                 kfree(q);
  58                 return NULL;
  59         }
  60
  61         q->maxlen = maxlen;
  62         q->qlen = 0;
  63         q->head = q->tail = 0;
  64         init_waitqueue_head(&q->midi_sleep);
  65         spin_lock_init(&q->lock);
  66         q->pre_event_timeout = SNDRV_SEQ_OSS_MAX_TIMEOUT;
  67         q->input_time = (unsigned long)-1;
  68
  69         return q;
  70 }
  71
  72 /*
  73  * delete the read queue
  74  */
  75 void
  76 snd_seq_oss_readq_delete(struct seq_oss_readq *q)
  77 {
  78         if (q) {
  79                 kfree(q->q);
  80                 kfree(q);
  81         }
  82 }
  83
  84 /*
  85  * reset the read queue
  86  */
  87 void
  88 snd_seq_oss_readq_clear(struct seq_oss_readq *q)
  89 {
  90         if (q->qlen) {
  91                 q->qlen = 0;
  92                 q->head = q->tail = 0;
  93         }
  94         /* if someone sleeping, wake'em up */
  95         if (waitqueue_active(&q->midi_sleep))
  96                 wake_up(&q->midi_sleep);
  97         q->input_time = (unsigned long)-1;
  98 }
  99
 100 /*
 101  * put a midi byte
 102  */
 103 int
 104 snd_seq_oss_readq_puts(struct seq_oss_readq *q, int dev, unsigned char *data, int len)
 105 {
 106         union evrec rec;
 107         int result;
 108
 109         memset(&rec, 0, sizeof(rec));
 110         rec.c[0] = SEQ_MIDIPUTC;
 111         rec.c[2] = dev;
 112
 113         while (len-- > 0) {
 114                 rec.c[1] = *data++;
 115                 result = snd_seq_oss_readq_put_event(q, &rec);
 116                 if (result < 0)
 117                         return result;
 118         }
 119         return 0;
 120 }
 121
 122 /*
 123  * put MIDI sysex bytes; the event buffer may be chained, thus it has
 124  * to be expanded via snd_seq_dump_var_event().
 125  */
 126 struct readq_sysex_ctx {
 127         struct seq_oss_readq *readq;
 128         int dev;
 129 };
 130
 131 static int readq_dump_sysex(void *ptr, void *buf, int count)
 132 {
 133         struct readq_sysex_ctx *ctx = ptr;
 134
 135         return snd_seq_oss_readq_puts(ctx->readq, ctx->dev, buf, count);
 136 }
 137
 138 int snd_seq_oss_readq_sysex(struct seq_oss_readq *q, int dev,
 139                             struct snd_seq_event *ev)
 140 {
 141         struct readq_sysex_ctx ctx = {
 142                 .readq = q,
 143                 .dev = dev
 144         };
 145
 146         if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
 147                 return 0;
 148         return snd_seq_dump_var_event(ev, readq_dump_sysex, &ctx);
 149 }
 150
 151 /*
 152  * copy an event to input queue:
 153  * return zero if enqueued
 154  */
 155 int
 156 snd_seq_oss_readq_put_event(struct seq_oss_readq *q, union evrec *ev)
 157 {
 158         unsigned long flags;
 159
 160         spin_lock_irqsave(&q->lock, flags);
 161         if (q->qlen >= q->maxlen - 1) {
 162                 spin_unlock_irqrestore(&q->lock, flags);
 163                 return -ENOMEM;
 164         }
 165
 166         memcpy(&q->q[q->tail], ev, sizeof(*ev));
 167         q->tail = (q->tail + 1) % q->maxlen;
 168         q->qlen++;
 169
 170         /* wake up sleeper */
 171         if (waitqueue_active(&q->midi_sleep))
 172                 wake_up(&q->midi_sleep);
 173
 174         spin_unlock_irqrestore(&q->lock, flags);
 175
 176         return 0;
 177 }
 178
 179
 180 /*
 181  * pop queue
 182  * caller must hold lock
 183  */
 184 int
 185 snd_seq_oss_readq_pick(struct seq_oss_readq *q, union evrec *rec)
 186 {
 187         if (q->qlen == 0)
 188                 return -EAGAIN;
 189         memcpy(rec, &q->q[q->head], sizeof(*rec));
 190         return 0;
 191 }
 192
 193 /*
 194  * sleep until ready
 195  */
 196 void
 197 snd_seq_oss_readq_wait(struct seq_oss_readq *q)
 198 {
 199         wait_event_interruptible_timeout(q->midi_sleep,
 200                                          (q->qlen > 0 || q->head == q->tail),
 201                                          q->pre_event_timeout);
 202 }
 203
 204 /*
 205  * drain one record
 206  * caller must hold lock
 207  */
 208 void
 209 snd_seq_oss_readq_free(struct seq_oss_readq *q)
 210 {
 211         if (q->qlen > 0) {
 212                 q->head = (q->head + 1) % q->maxlen;
 213                 q->qlen--;
 214         }
 215 }
 216
 217 /*
 218  * polling/select:
 219  * return non-zero if readq is not empty.
 220  */
 221 unsigned int
 222 snd_seq_oss_readq_poll(struct seq_oss_readq *q, struct file *file, poll_table *wait)
 223 {
 224         poll_wait(file, &q->midi_sleep, wait);
 225         return q->qlen;
 226 }
 227
 228 /*
 229  * put a timestamp
 230  */
 231 int
 232 snd_seq_oss_readq_put_timestamp(struct seq_oss_readq *q, unsigned long curt, int seq_mode)
 233 {
 234         if (curt != q->input_time) {
 235                 union evrec rec;
 236                 memset(&rec, 0, sizeof(rec));
 237                 switch (seq_mode) {
 238                 case SNDRV_SEQ_OSS_MODE_SYNTH:
 239                         rec.echo = (curt << 8) | SEQ_WAIT;
 240                         snd_seq_oss_readq_put_event(q, &rec);
 241                         break;
 242                 case SNDRV_SEQ_OSS_MODE_MUSIC:
 243                         rec.t.code = EV_TIMING;
 244                         rec.t.cmd = TMR_WAIT_ABS;
 245                         rec.t.time = curt;
 246                         snd_seq_oss_readq_put_event(q, &rec);
 247                         break;
 248                 }
 249                 q->input_time = curt;
 250         }
 251         return 0;
 252 }
 253
 254
 255 #ifdef CONFIG_PROC_FS
 256 /*
 257  * proc interface
 258  */
 259 void
 260 snd_seq_oss_readq_info_read(struct seq_oss_readq *q, struct snd_info_buffer *buf)
 261 {
 262         snd_iprintf(buf, "  read queue [%s] length = %d : tick = %ld\n",
 263                     (waitqueue_active(&q->midi_sleep) ? "sleeping":"running"),
 264                     q->qlen, q->input_time);
 265 }
 266 #endif /* CONFIG_PROC_FS */