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/*
* Advanced Linux Sound Architecture
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
*
*
* 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/init.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/device.h>
#include <linux/moduleparam.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/info.h>
#include <sound/version.h>
#include <sound/control.h>
#include <sound/initval.h>
#include <linux/kmod.h>
#include <linux/mutex.h>
#define SNDRV_OS_MINORS 256
static int major = CONFIG_SND_MAJOR;
int snd_major;
EXPORT_SYMBOL(snd_major);
static int cards_limit = 1;
MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
MODULE_LICENSE("GPL");
module_param(major, int, 0444);
MODULE_PARM_DESC(major, "Major # for sound driver.");
module_param(cards_limit, int, 0444);
MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
/* this one holds the actual max. card number currently available.
* as default, it's identical with cards_limit option. when more
* modules are loaded manually, this limit number increases, too.
*/
int snd_ecards_limit;
EXPORT_SYMBOL(snd_ecards_limit);
static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
static DEFINE_MUTEX(sound_mutex);
#ifdef CONFIG_KMOD
/**
* snd_request_card - try to load the card module
* @card: the card number
*
* Tries to load the module "snd-card-X" for the given card number
* via KMOD. Returns immediately if already loaded.
*/
void snd_request_card(int card)
{
if (! current->fs->root)
return;
if (snd_card_locked(card))
return;
if (card < 0 || card >= cards_limit)
return;
request_module("snd-card-%i", card);
}
EXPORT_SYMBOL(snd_request_card);
static void snd_request_other(int minor)
{
char *str;
if (! current->fs->root)
return;
switch (minor) {
case SNDRV_MINOR_SEQUENCER: str = "snd-seq"; break;
case SNDRV_MINOR_TIMER: str = "snd-timer"; break;
default: return;
}
request_module(str);
}
#endif /* request_module support */
/**
* snd_lookup_minor_data - get user data of a registered device
* @minor: the minor number
* @type: device type (SNDRV_DEVICE_TYPE_XXX)
*
* Checks that a minor device with the specified type is registered, and returns
* its user data pointer.
*/
void *snd_lookup_minor_data(unsigned int minor, int type)
{
struct snd_minor *mreg;
void *private_data;
if (minor >= ARRAY_SIZE(snd_minors))
return NULL;
mutex_lock(&sound_mutex);
mreg = snd_minors[minor];
if (mreg && mreg->type == type)
private_data = mreg->private_data;
else
private_data = NULL;
mutex_unlock(&sound_mutex);
return private_data;
}
EXPORT_SYMBOL(snd_lookup_minor_data);
static int snd_open(struct inode *inode, struct file *file)
{
unsigned int minor = iminor(inode);
struct snd_minor *mptr = NULL;
const struct file_operations *old_fops;
int err = 0;
if (minor >= ARRAY_SIZE(snd_minors))
return -ENODEV;
mptr = snd_minors[minor];
if (mptr == NULL) {
#ifdef CONFIG_KMOD
int dev = SNDRV_MINOR_DEVICE(minor);
if (dev == SNDRV_MINOR_CONTROL) {
/* /dev/aloadC? */
int card = SNDRV_MINOR_CARD(minor);
if (snd_cards[card] == NULL)
snd_request_card(card);
} else if (dev == SNDRV_MINOR_GLOBAL) {
/* /dev/aloadSEQ */
snd_request_other(minor);
}
#ifndef CONFIG_SND_DYNAMIC_MINORS
/* /dev/snd/{controlC?,seq} */
mptr = snd_minors[minor];
if (mptr == NULL)
#endif
#endif
return -ENODEV;
}
old_fops = file->f_op;
file->f_op = fops_get(mptr->f_ops);
if (file->f_op->open)
err = file->f_op->open(inode, file);
if (err) {
fops_put(file->f_op);
file->f_op = fops_get(old_fops);
}
fops_put(old_fops);
return err;
}
static const struct file_operations snd_fops =
{
.owner = THIS_MODULE,
.open = snd_open
};
#ifdef CONFIG_SND_DYNAMIC_MINORS
static int snd_find_free_minor(void)
{
int minor;
for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
/* skip minors still used statically for autoloading devices */
if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL ||
minor == SNDRV_MINOR_SEQUENCER)
continue;
if (!snd_minors[minor])
return minor;
}
return -EBUSY;
}
#else
static int snd_kernel_minor(int type, struct snd_card *card, int dev)
{
int minor;
switch (type) {
case SNDRV_DEVICE_TYPE_SEQUENCER:
case SNDRV_DEVICE_TYPE_TIMER:
minor = type;
break;
case SNDRV_DEVICE_TYPE_CONTROL:
snd_assert(card != NULL, return -EINVAL);
minor = SNDRV_MINOR(card->number, type);
break;
case SNDRV_DEVICE_TYPE_HWDEP:
case SNDRV_DEVICE_TYPE_RAWMIDI:
case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
snd_assert(card != NULL, return -EINVAL);
minor = SNDRV_MINOR(card->number, type + dev);
break;
default:
return -EINVAL;
}
snd_assert(minor >= 0 && minor < SNDRV_OS_MINORS, return -EINVAL);
return minor;
}
#endif
/**
* snd_register_device_for_dev - Register the ALSA device file for the card
* @type: the device type, SNDRV_DEVICE_TYPE_XXX
* @card: the card instance
* @dev: the device index
* @f_ops: the file operations
* @private_data: user pointer for f_ops->open()
* @name: the device file name
* @device: the &struct device to link this new device to
*
* Registers an ALSA device file for the given card.
* The operators have to be set in reg parameter.
*
* Returns zero if successful, or a negative error code on failure.
*/
int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
const struct file_operations *f_ops,
void *private_data,
const char *name, struct device *device)
{
int minor;
struct snd_minor *preg;
snd_assert(name, return -EINVAL);
preg = kmalloc(sizeof *preg, GFP_KERNEL);
if (preg == NULL)
return -ENOMEM;
preg->type = type;
preg->card = card ? card->number : -1;
preg->device = dev;
preg->f_ops = f_ops;
preg->private_data = private_data;
mutex_lock(&sound_mutex);
#ifdef CONFIG_SND_DYNAMIC_MINORS
minor = snd_find_free_minor();
#else
minor = snd_kernel_minor(type, card, dev);
if (minor >= 0 && snd_minors[minor])
minor = -EBUSY;
#endif
if (minor < 0) {
mutex_unlock(&sound_mutex);
kfree(preg);
return minor;
}
snd_minors[minor] = preg;
preg->dev = device_create(sound_class, device, MKDEV(major, minor),
"%s", name);
if (IS_ERR(preg->dev)) {
snd_minors[minor] = NULL;
mutex_unlock(&sound_mutex);
minor = PTR_ERR(preg->dev);
kfree(preg);
return minor;
}
if (preg->dev)
dev_set_drvdata(preg->dev, private_data);
mutex_unlock(&sound_mutex);
return 0;
}
EXPORT_SYMBOL(snd_register_device_for_dev);
/* find the matching minor record
* return the index of snd_minor, or -1 if not found
*/
static
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