diff options
Diffstat (limited to 'sound/core/seq/oss/seq_oss_readq.c')
| -rw-r--r-- | sound/core/seq/oss/seq_oss_readq.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/sound/core/seq/oss/seq_oss_readq.c b/sound/core/seq/oss/seq_oss_readq.c new file mode 100644 index 000000000..f0db5d3dc --- /dev/null +++ b/sound/core/seq/oss/seq_oss_readq.c @@ -0,0 +1,250 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * OSS compatible sequencer driver + * + * seq_oss_readq.c - MIDI input queue + * + * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de> + */ + +#include "seq_oss_readq.h" +#include "seq_oss_event.h" +#include <sound/seq_oss_legacy.h> +#include "../seq_lock.h" +#include <linux/wait.h> +#include <linux/slab.h> + +/* + * constants + */ +//#define SNDRV_SEQ_OSS_MAX_TIMEOUT (unsigned long)(-1) +#define SNDRV_SEQ_OSS_MAX_TIMEOUT (HZ * 3600) + + +/* + * prototypes + */ + + +/* + * create a read queue + */ +struct seq_oss_readq * +snd_seq_oss_readq_new(struct seq_oss_devinfo *dp, int maxlen) +{ + struct seq_oss_readq *q; + + q = kzalloc(sizeof(*q), GFP_KERNEL); + if (!q) + return NULL; + + q->q = kcalloc(maxlen, sizeof(union evrec), GFP_KERNEL); + if (!q->q) { + kfree(q); + return NULL; + } + + q->maxlen = maxlen; + q->qlen = 0; + q->head = q->tail = 0; + init_waitqueue_head(&q->midi_sleep); + spin_lock_init(&q->lock); + q->pre_event_timeout = SNDRV_SEQ_OSS_MAX_TIMEOUT; + q->input_time = (unsigned long)-1; + + return q; +} + +/* + * delete the read queue + */ +void +snd_seq_oss_readq_delete(struct seq_oss_readq *q) +{ + if (q) { + kfree(q->q); + kfree(q); + } +} + +/* + * reset the read queue + */ +void +snd_seq_oss_readq_clear(struct seq_oss_readq *q) +{ + if (q->qlen) { + q->qlen = 0; + q->head = q->tail = 0; + } + /* if someone sleeping, wake'em up */ + wake_up(&q->midi_sleep); + q->input_time = (unsigned long)-1; +} + +/* + * put a midi byte + */ +int +snd_seq_oss_readq_puts(struct seq_oss_readq *q, int dev, unsigned char *data, int len) +{ + union evrec rec; + int result; + + memset(&rec, 0, sizeof(rec)); + rec.c[0] = SEQ_MIDIPUTC; + rec.c[2] = dev; + + while (len-- > 0) { + rec.c[1] = *data++; + result = snd_seq_oss_readq_put_event(q, &rec); + if (result < 0) + return result; + } + return 0; +} + +/* + * put MIDI sysex bytes; the event buffer may be chained, thus it has + * to be expanded via snd_seq_dump_var_event(). + */ +struct readq_sysex_ctx { + struct seq_oss_readq *readq; + int dev; +}; + +static int readq_dump_sysex(void *ptr, void *buf, int count) +{ + struct readq_sysex_ctx *ctx = ptr; + + return snd_seq_oss_readq_puts(ctx->readq, ctx->dev, buf, count); +} + +int snd_seq_oss_readq_sysex(struct seq_oss_readq *q, int dev, + struct snd_seq_event *ev) +{ + struct readq_sysex_ctx ctx = { + .readq = q, + .dev = dev + }; + + if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE) + return 0; + return snd_seq_dump_var_event(ev, readq_dump_sysex, &ctx); +} + +/* + * copy an event to input queue: + * return zero if enqueued + */ +int +snd_seq_oss_readq_put_event(struct seq_oss_readq *q, union evrec *ev) +{ + unsigned long flags; + + spin_lock_irqsave(&q->lock, flags); + if (q->qlen >= q->maxlen - 1) { + spin_unlock_irqrestore(&q->lock, flags); + return -ENOMEM; + } + + memcpy(&q->q[q->tail], ev, sizeof(*ev)); + q->tail = (q->tail + 1) % q->maxlen; + q->qlen++; + + /* wake up sleeper */ + wake_up(&q->midi_sleep); + + spin_unlock_irqrestore(&q->lock, flags); + + return 0; +} + + +/* + * pop queue + * caller must hold lock + */ +int +snd_seq_oss_readq_pick(struct seq_oss_readq *q, union evrec *rec) +{ + if (q->qlen == 0) + return -EAGAIN; + memcpy(rec, &q->q[q->head], sizeof(*rec)); + return 0; +} + +/* + * sleep until ready + */ +void +snd_seq_oss_readq_wait(struct seq_oss_readq *q) +{ + wait_event_interruptible_timeout(q->midi_sleep, + (q->qlen > 0 || q->head == q->tail), + q->pre_event_timeout); +} + +/* + * drain one record + * caller must hold lock + */ +void +snd_seq_oss_readq_free(struct seq_oss_readq *q) +{ + if (q->qlen > 0) { + q->head = (q->head + 1) % q->maxlen; + q->qlen--; + } +} + +/* + * polling/select: + * return non-zero if readq is not empty. + */ +unsigned int +snd_seq_oss_readq_poll(struct seq_oss_readq *q, struct file *file, poll_table *wait) +{ + poll_wait(file, &q->midi_sleep, wait); + return q->qlen; +} + +/* + * put a timestamp + */ +int +snd_seq_oss_readq_put_timestamp(struct seq_oss_readq *q, unsigned long curt, int seq_mode) +{ + if (curt != q->input_time) { + union evrec rec; + memset(&rec, 0, sizeof(rec)); + switch (seq_mode) { + case SNDRV_SEQ_OSS_MODE_SYNTH: + rec.echo = (curt << 8) | SEQ_WAIT; + snd_seq_oss_readq_put_event(q, &rec); + break; + case SNDRV_SEQ_OSS_MODE_MUSIC: + rec.t.code = EV_TIMING; + rec.t.cmd = TMR_WAIT_ABS; + rec.t.time = curt; + snd_seq_oss_readq_put_event(q, &rec); + break; + } + q->input_time = curt; + } + return 0; +} + + +#ifdef CONFIG_SND_PROC_FS +/* + * proc interface + */ +void +snd_seq_oss_readq_info_read(struct seq_oss_readq *q, struct snd_info_buffer *buf) +{ + snd_iprintf(buf, " read queue [%s] length = %d : tick = %ld\n", + (waitqueue_active(&q->midi_sleep) ? "sleeping":"running"), + q->qlen, q->input_time); +} +#endif /* CONFIG_SND_PROC_FS */ |