linux/include/sound/seq_kernel.h
Takashi Iwai 68ab61084d ALSA: seq: bind seq driver automatically
Currently the sequencer module binding is performed independently from
the card module itself.  The reason behind it is to keep the sequencer
stuff optional and allow the system running without it (e.g. for using
PCM or rawmidi only).  This works in most cases, but a remaining
problem is that the binding isn't done automatically when a new driver
module is probed.  Typically this becomes visible when a hotplug
driver like usb audio is used.

This patch tries to address this and other potential issues.  First,
the seq-binder (seq_device.c) tries to load a missing driver module at
creating a new device object.  This is done asynchronously in a workq
for avoiding the deadlock (modprobe call in module init path).

This action, however, should be enabled only when the sequencer stuff
was already initialized, i.e. snd-seq module was already loaded.  For
that, a new function, snd_seq_autoload_init() is introduced here; this
clears the blocking of autoloading, and also tries to load all pending
driver modules.

Reported-by: Adam Goode <agoode@chromium.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-10-18 20:25:12 +02:00

121 lines
4.3 KiB
C

#ifndef __SOUND_SEQ_KERNEL_H
#define __SOUND_SEQ_KERNEL_H
/*
* Main kernel header file for the ALSA sequencer
* Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/time.h>
#include <sound/asequencer.h>
typedef struct snd_seq_real_time snd_seq_real_time_t;
typedef union snd_seq_timestamp snd_seq_timestamp_t;
/* maximum number of events dequeued per schedule interval */
#define SNDRV_SEQ_MAX_DEQUEUE 50
/* maximum number of queues */
#define SNDRV_SEQ_MAX_QUEUES 8
/* max number of concurrent clients */
#define SNDRV_SEQ_MAX_CLIENTS 192
/* max number of concurrent ports */
#define SNDRV_SEQ_MAX_PORTS 254
/* max number of events in memory pool */
#define SNDRV_SEQ_MAX_EVENTS 2000
/* default number of events in memory chunk */
#define SNDRV_SEQ_DEFAULT_CHUNK_EVENTS 64
/* default number of events in memory pool */
#define SNDRV_SEQ_DEFAULT_EVENTS 500
/* max number of events in memory pool for one client (outqueue) */
#define SNDRV_SEQ_MAX_CLIENT_EVENTS 2000
/* default number of events in memory pool for one client (outqueue) */
#define SNDRV_SEQ_DEFAULT_CLIENT_EVENTS 200
/* max delivery path length */
#define SNDRV_SEQ_MAX_HOPS 10
/* max size of event size */
#define SNDRV_SEQ_MAX_EVENT_LEN 0x3fffffff
/* call-backs for kernel port */
struct snd_seq_port_callback {
struct module *owner;
void *private_data;
int (*subscribe)(void *private_data, struct snd_seq_port_subscribe *info);
int (*unsubscribe)(void *private_data, struct snd_seq_port_subscribe *info);
int (*use)(void *private_data, struct snd_seq_port_subscribe *info);
int (*unuse)(void *private_data, struct snd_seq_port_subscribe *info);
int (*event_input)(struct snd_seq_event *ev, int direct, void *private_data, int atomic, int hop);
void (*private_free)(void *private_data);
unsigned int callback_all; /* call subscribe callbacks at each connection/disconnection */
/*...*/
};
/* interface for kernel client */
__printf(3, 4)
int snd_seq_create_kernel_client(struct snd_card *card, int client_index,
const char *name_fmt, ...);
int snd_seq_delete_kernel_client(int client);
int snd_seq_kernel_client_enqueue(int client, struct snd_seq_event *ev, int atomic, int hop);
int snd_seq_kernel_client_dispatch(int client, struct snd_seq_event *ev, int atomic, int hop);
int snd_seq_kernel_client_ctl(int client, unsigned int cmd, void *arg);
#define SNDRV_SEQ_EXT_MASK 0xc0000000
#define SNDRV_SEQ_EXT_USRPTR 0x80000000
#define SNDRV_SEQ_EXT_CHAINED 0x40000000
typedef int (*snd_seq_dump_func_t)(void *ptr, void *buf, int count);
int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char *buf,
int in_kernel, int size_aligned);
int snd_seq_dump_var_event(const struct snd_seq_event *event,
snd_seq_dump_func_t func, void *private_data);
/* interface for OSS emulation */
int snd_seq_set_queue_tempo(int client, struct snd_seq_queue_tempo *tempo);
/* port callback routines */
void snd_port_init_callback(struct snd_seq_port_callback *p);
struct snd_seq_port_callback *snd_port_alloc_callback(void);
/* port attach/detach */
int snd_seq_event_port_attach(int client, struct snd_seq_port_callback *pcbp,
int cap, int type, int midi_channels, int midi_voices, char *portname);
int snd_seq_event_port_detach(int client, int port);
#ifdef CONFIG_MODULES
void snd_seq_autoload_lock(void);
void snd_seq_autoload_unlock(void);
void snd_seq_autoload_init(void);
#define snd_seq_autoload_exit() snd_seq_autoload_lock()
#else
#define snd_seq_autoload_lock()
#define snd_seq_autoload_unlock()
#define snd_seq_autoload_init()
#define snd_seq_autoload_exit()
#endif
#endif /* __SOUND_SEQ_KERNEL_H */