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/*
* ALSA sequencer device management
* Copyright (c) 1999 by Takashi Iwai <tiwai@suse.de>
*
* 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
*
*
*----------------------------------------------------------------
*
* This device handler separates the card driver module from sequencer
* stuff (sequencer core, synth drivers, etc), so that user can avoid
* to spend unnecessary resources e.g. if he needs only listening to
* MP3s.
*
* The card (or lowlevel) driver creates a sequencer device entry
* via snd_seq_device_new(). This is an entry pointer to communicate
* with the sequencer device "driver", which is involved with the
* actual part to communicate with the sequencer core.
* Each sequencer device entry has an id string and the corresponding
* driver with the same id is loaded when required. For example,
* lowlevel codes to access emu8000 chip on sbawe card are included in
* emu8000-synth module. To activate this module, the hardware
* resources like i/o port are passed via snd_seq_device argument.
*
*/
#include <linux/init.h>
#include <sound/core.h>
#include <sound/info.h>
#include <sound/seq_device.h>
#include <sound/seq_kernel.h>
#include <sound/initval.h>
#include <linux/kmod.h>
#include <linux/slab.h>
#include <linux/mutex.h>
MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
MODULE_DESCRIPTION("ALSA sequencer device management");
MODULE_LICENSE("GPL");
/* driver state */
#define DRIVER_EMPTY 0
#define DRIVER_LOADED (1<<0)
#define DRIVER_REQUESTED (1<<1)
#define DRIVER_LOCKED (1<<2)
struct ops_list {
char id[ID_LEN]; /* driver id */
int driver; /* driver state */
int used; /* reference counter */
int argsize; /* argument size */
/* operators */
struct snd_seq_dev_ops ops;
/* registred devices */
struct list_head dev_list; /* list of devices */
int num_devices; /* number of associated devices */
int num_init_devices; /* number of initialized devices */
struct mutex reg_mutex;
struct list_head list; /* next driver */
};
static LIST_HEAD(opslist);
static int num_ops;
static DEFINE_MUTEX(ops_mutex);
#ifdef CONFIG_PROC_FS
static struct snd_info_entry *info_entry;
#endif
/*
* prototypes
*/
static int snd_seq_device_free(struct snd_seq_device *dev);
static int snd_seq_device_dev_free(struct snd_device *device);
static int snd_seq_device_dev_register(struct snd_device *device);
static int snd_seq_device_dev_disconnect(struct snd_device *device);
static int init_device(struct snd_seq_device *dev, struct ops_list *ops);
static int free_device(struct snd_seq_device *dev, struct ops_list *ops);
static struct ops_list *find_driver(char *id, int create_if_empty);
static struct ops_list *create_driver(char *id);
static void unlock_driver(struct ops_list *ops);
static void remove_drivers(void);
/*
* show all drivers and their status
*/
#ifdef CONFIG_PROC_FS
static void snd_seq_device_info(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct ops_list *ops;
mutex_lock(&ops_mutex);
list_for_each_entry(ops, &opslist, list) {
snd_iprintf(buffer, "snd-%s%s%s%s,%d\n",
ops->id,
ops->driver & DRIVER_LOADED ? ",loaded" : (ops->driver == DRIVER_EMPTY ? ",empty" : ""),
ops->driver & DRIVER_REQUESTED ? ",requested" : "",
ops->driver & DRIVER_LOCKED ? ",locked" : "",
ops->num_devices);
}
mutex_unlock(&ops_mutex);
}
#endif
/*
* load all registered drivers (called from seq_clientmgr.c)
*/
#ifdef CONFIG_KMOD
/* avoid auto-loading during module_init() */
static int snd_seq_in_init;
void snd_seq_autoload_lock(void)
{
snd_seq_in_init++;
}
void snd_seq_autoload_unlock(void)
{
snd_seq_in_init--;
}
#endif
void snd_seq_device_load_drivers(void)
{
#ifdef CONFIG_KMOD
struct ops_list *ops;
/* Calling request_module during module_init()
* may cause blocking.
*/
if (snd_seq_in_init)
return;
mutex_lock(&ops_mutex);
list_for_each_entry(ops, &opslist, list) {
if (! (ops->driver & DRIVER_LOADED) &&
! (ops->driver & DRIVER_REQUESTED)) {
ops->used++;
mutex_unlock(&ops_mutex);
ops->driver |= DRIVER_REQUESTED;
request_module("snd-%s", ops->id);
mutex_lock(&ops_mutex);
ops->used--;
}
}
mutex_unlock(&ops_mutex);
#endif
}
/*
* register a sequencer device
* card = card info (NULL allowed)
* device = device number (if any)
* id = id of driver
* result = return pointer (NULL allowed if unnecessary)
*/
int snd_seq_device_new(struct snd_card *card, int device, char *id, int argsize,
struct snd_seq_device **result)
{
struct snd_seq_device *dev;
struct ops_list *ops;
int err;
static struct snd_device_ops dops = {
.dev_free = snd_seq_device_dev_free,
.dev_register = snd_seq_device_dev_register,
.dev_disconnect = snd_seq_device_dev_disconnect,
};
if (result)
*result = NULL;
snd_assert(id != NULL, return -EINVAL);
ops = find_driver(id, 1);
if (ops == NULL)
return -ENOMEM;
dev = kzalloc(sizeof(*dev)*2 + argsize, GFP_KERNEL);
if (dev == NULL) {
unlock_driver(ops);
return -ENOMEM;
}
/* set up device info */
dev->card = card;
dev->device = device;
strlcpy(dev->id, id, sizeof(dev->id));
dev->argsize = argsize;
dev->status = SNDRV_SEQ_DEVICE_FREE;
/* add this device to the list */
mutex_lock(&ops->reg_mutex);
list_add_tail(&dev->list, &ops->dev_list);
ops->num_devices++;
mutex_unlock(&ops->reg_mutex);
unlock_driver(ops);
if ((err = snd_device_new(card, SNDRV_DEV_SEQUENCER, dev, &dops)) < 0) {
snd_seq_device_free(dev);
return err;
}
if (result)
*result = dev;
return 0;
}
/*
* free the existing device
*/
static int snd_seq_device_free(struct snd_seq_device *dev)
{
struct ops_list *ops;
snd_assert(dev != NULL, return -EINVAL);
ops = find_driver(dev->id, 0);
if (ops == NULL)
return -ENXIO;
/* remove the device from the list */
mutex_lock(&ops->reg_mutex);
list_del(&dev->list);
ops->num_devices--;
mutex_unlock(&ops->reg_mutex);
free_device(dev, ops);
if (dev->private_free)
dev->private_free(dev);
kfree(dev);
unlock_driver(ops);
return 0;
}
static int snd_seq_device_dev_free(struct snd_device *device)
{
struct snd_seq_device *dev = device->device_data;
return snd_seq_device_free(dev);
}
/*
* register the device
*/
static int snd_seq_device_dev_register(struct snd_device *device)
{
struct snd_seq_device *dev = device->device_data;
struct ops_list *ops;
ops = find_driver(dev->id, 0);
if (ops == NULL)
return -ENOENT;
/* initialize this device if the corresponding driver was
* already loaded
*/
if
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