sound/drivers/opl3/opl3_oss.c

Source file repositories/reference/linux-study-clean/sound/drivers/opl3/opl3_oss.c

File Facts

System
Linux kernel
Corpus path
sound/drivers/opl3/opl3_oss.c
Extension
.c
Size
6156 bytes
Lines
255
Domain
Driver Families
Bucket
sound/drivers
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Interface for OSS sequencer emulation
 *
 *  Copyright (C) 2000 Uros Bizjak <uros@kss-loka.si>
 */

#include <linux/export.h>
#include "opl3_voice.h"

static int snd_opl3_open_seq_oss(struct snd_seq_oss_arg *arg, void *closure);
static int snd_opl3_close_seq_oss(struct snd_seq_oss_arg *arg);
static int snd_opl3_ioctl_seq_oss(struct snd_seq_oss_arg *arg, unsigned int cmd, unsigned long ioarg);
static int snd_opl3_load_patch_seq_oss(struct snd_seq_oss_arg *arg, int format, const char __user *buf, int offs, int count);
static int snd_opl3_reset_seq_oss(struct snd_seq_oss_arg *arg);

/* operators */

static const struct snd_seq_oss_callback oss_callback = {
	.owner = 	THIS_MODULE,
	.open =		snd_opl3_open_seq_oss,
	.close =	snd_opl3_close_seq_oss,
	.ioctl =	snd_opl3_ioctl_seq_oss,
	.load_patch =	snd_opl3_load_patch_seq_oss,
	.reset =	snd_opl3_reset_seq_oss,
};

static int snd_opl3_oss_event_input(struct snd_seq_event *ev, int direct,
				    void *private_data, int atomic, int hop)
{
	struct snd_opl3 *opl3 = private_data;

	if (ev->type != SNDRV_SEQ_EVENT_OSS)
		snd_midi_process_event(&opl3_ops, ev, opl3->oss_chset);
	return 0;
}

/* ------------------------------ */

static void snd_opl3_oss_free_port(void *private_data)
{
	struct snd_opl3 *opl3 = private_data;

	snd_midi_channel_free_set(opl3->oss_chset);
}

static int snd_opl3_oss_create_port(struct snd_opl3 * opl3)
{
	struct snd_seq_port_callback callbacks;
	char name[32];
	int voices, opl_ver;

	voices = (opl3->hardware < OPL3_HW_OPL3) ?
		MAX_OPL2_VOICES : MAX_OPL3_VOICES;
	opl3->oss_chset = snd_midi_channel_alloc_set(voices);
	if (opl3->oss_chset == NULL)
		return -ENOMEM;
	opl3->oss_chset->private_data = opl3;

	memset(&callbacks, 0, sizeof(callbacks));
	callbacks.owner = THIS_MODULE;
	callbacks.event_input = snd_opl3_oss_event_input;
	callbacks.private_free = snd_opl3_oss_free_port;
	callbacks.private_data = opl3;

	opl_ver = (opl3->hardware & OPL3_HW_MASK) >> 8;
	sprintf(name, "OPL%i OSS Port", opl_ver);

	opl3->oss_chset->client = opl3->seq_client;
	opl3->oss_chset->port = snd_seq_event_port_attach(opl3->seq_client, &callbacks,
							  SNDRV_SEQ_PORT_CAP_WRITE,
							  SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC |
							  SNDRV_SEQ_PORT_TYPE_MIDI_GM |
							  SNDRV_SEQ_PORT_TYPE_HARDWARE |
							  SNDRV_SEQ_PORT_TYPE_SYNTHESIZER,
							  voices, voices,
							  name);
	if (opl3->oss_chset->port < 0) {
		int port;
		port = opl3->oss_chset->port;
		snd_midi_channel_free_set(opl3->oss_chset);
		return port;
	}
	return 0;
}

/* ------------------------------ */

/* register OSS synth */
void snd_opl3_init_seq_oss(struct snd_opl3 *opl3, char *name)

Annotation

Implementation Notes