251 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * OSS compatible sequencer driver4 *5 * seq_oss_readq.c - MIDI input queue6 *7 * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>8 */9 10#include "seq_oss_readq.h"11#include "seq_oss_event.h"12#include <sound/seq_oss_legacy.h>13#include "../seq_lock.h"14#include <linux/wait.h>15#include <linux/slab.h>16 17/*18 * constants19 */20//#define SNDRV_SEQ_OSS_MAX_TIMEOUT (unsigned long)(-1)21#define SNDRV_SEQ_OSS_MAX_TIMEOUT (HZ * 3600)22 23 24/*25 * prototypes26 */27 28 29/*30 * create a read queue31 */32struct seq_oss_readq *33snd_seq_oss_readq_new(struct seq_oss_devinfo *dp, int maxlen)34{35 struct seq_oss_readq *q;36 37 q = kzalloc(sizeof(*q), GFP_KERNEL);38 if (!q)39 return NULL;40 41 q->q = kcalloc(maxlen, sizeof(union evrec), GFP_KERNEL);42 if (!q->q) {43 kfree(q);44 return NULL;45 }46 47 q->maxlen = maxlen;48 q->qlen = 0;49 q->head = q->tail = 0;50 init_waitqueue_head(&q->midi_sleep);51 spin_lock_init(&q->lock);52 q->pre_event_timeout = SNDRV_SEQ_OSS_MAX_TIMEOUT;53 q->input_time = (unsigned long)-1;54 55 return q;56}57 58/*59 * delete the read queue60 */61void62snd_seq_oss_readq_delete(struct seq_oss_readq *q)63{64 if (q) {65 kfree(q->q);66 kfree(q);67 }68}69 70/*71 * reset the read queue72 */73void74snd_seq_oss_readq_clear(struct seq_oss_readq *q)75{76 if (q->qlen) {77 q->qlen = 0;78 q->head = q->tail = 0;79 }80 /* if someone sleeping, wake'em up */81 wake_up(&q->midi_sleep);82 q->input_time = (unsigned long)-1;83}84 85/*86 * put a midi byte87 */88int89snd_seq_oss_readq_puts(struct seq_oss_readq *q, int dev, unsigned char *data, int len)90{91 union evrec rec;92 int result;93 94 memset(&rec, 0, sizeof(rec));95 rec.c[0] = SEQ_MIDIPUTC;96 rec.c[2] = dev;97 98 while (len-- > 0) {99 rec.c[1] = *data++;100 result = snd_seq_oss_readq_put_event(q, &rec);101 if (result < 0)102 return result;103 }104 return 0;105}106 107/*108 * put MIDI sysex bytes; the event buffer may be chained, thus it has109 * to be expanded via snd_seq_dump_var_event().110 */111struct readq_sysex_ctx {112 struct seq_oss_readq *readq;113 int dev;114};115 116static int readq_dump_sysex(void *ptr, void *buf, int count)117{118 struct readq_sysex_ctx *ctx = ptr;119 120 return snd_seq_oss_readq_puts(ctx->readq, ctx->dev, buf, count);121}122 123int snd_seq_oss_readq_sysex(struct seq_oss_readq *q, int dev,124 struct snd_seq_event *ev)125{126 struct readq_sysex_ctx ctx = {127 .readq = q,128 .dev = dev129 };130 131 if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)132 return 0;133 return snd_seq_dump_var_event(ev, readq_dump_sysex, &ctx);134}135 136/*137 * copy an event to input queue:138 * return zero if enqueued139 */140int141snd_seq_oss_readq_put_event(struct seq_oss_readq *q, union evrec *ev)142{143 unsigned long flags;144 145 spin_lock_irqsave(&q->lock, flags);146 if (q->qlen >= q->maxlen - 1) {147 spin_unlock_irqrestore(&q->lock, flags);148 return -ENOMEM;149 }150 151 memcpy(&q->q[q->tail], ev, sizeof(*ev));152 q->tail = (q->tail + 1) % q->maxlen;153 q->qlen++;154 155 /* wake up sleeper */156 wake_up(&q->midi_sleep);157 158 spin_unlock_irqrestore(&q->lock, flags);159 160 return 0;161}162 163 164/*165 * pop queue166 * caller must hold lock167 */168int169snd_seq_oss_readq_pick(struct seq_oss_readq *q, union evrec *rec)170{171 if (q->qlen == 0)172 return -EAGAIN;173 memcpy(rec, &q->q[q->head], sizeof(*rec));174 return 0;175}176 177/*178 * sleep until ready179 */180void181snd_seq_oss_readq_wait(struct seq_oss_readq *q)182{183 wait_event_interruptible_timeout(q->midi_sleep,184 (q->qlen > 0 || q->head == q->tail),185 q->pre_event_timeout);186}187 188/*189 * drain one record190 * caller must hold lock191 */192void193snd_seq_oss_readq_free(struct seq_oss_readq *q)194{195 if (q->qlen > 0) {196 q->head = (q->head + 1) % q->maxlen;197 q->qlen--;198 }199}200 201/*202 * polling/select:203 * return non-zero if readq is not empty.204 */205unsigned int206snd_seq_oss_readq_poll(struct seq_oss_readq *q, struct file *file, poll_table *wait)207{208 poll_wait(file, &q->midi_sleep, wait);209 return q->qlen;210}211 212/*213 * put a timestamp214 */215int216snd_seq_oss_readq_put_timestamp(struct seq_oss_readq *q, unsigned long curt, int seq_mode)217{218 if (curt != q->input_time) {219 union evrec rec;220 memset(&rec, 0, sizeof(rec));221 switch (seq_mode) {222 case SNDRV_SEQ_OSS_MODE_SYNTH:223 rec.echo = (curt << 8) | SEQ_WAIT;224 snd_seq_oss_readq_put_event(q, &rec);225 break;226 case SNDRV_SEQ_OSS_MODE_MUSIC:227 rec.t.code = EV_TIMING;228 rec.t.cmd = TMR_WAIT_ABS;229 rec.t.time = curt;230 snd_seq_oss_readq_put_event(q, &rec);231 break;232 }233 q->input_time = curt;234 }235 return 0;236}237 238 239#ifdef CONFIG_SND_PROC_FS240/*241 * proc interface242 */243void244snd_seq_oss_readq_info_read(struct seq_oss_readq *q, struct snd_info_buffer *buf)245{246 snd_iprintf(buf, " read queue [%s] length = %d : tick = %ld\n",247 (waitqueue_active(&q->midi_sleep) ? "sleeping":"running"),248 q->qlen, q->input_time);249}250#endif /* CONFIG_SND_PROC_FS */251