linux/sound/core/sound.c
Jaroslav Kysela 4266274836 ALSA: remove the main version information
Remove the main ALSA version number from the kernel ALSA driver.
The ALSA driver package release diverges from the upstream. This may
confuse users to see the same ALSA version for many kernel releases
and this version lost it's original purpose and connection.

The "ioctl" APIs have own version numbers, so the user space may check
for specific API changes only.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
2012-09-04 11:38:32 +02:00

484 lines
12 KiB
C

/*
* 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/module.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/info.h>
#include <sound/control.h>
#include <sound/initval.h>
#include <linux/kmod.h>
#include <linux/mutex.h>
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_MODULES
/**
* 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 request_module. Returns immediately if already loaded.
*/
void snd_request_card(int card)
{
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;
switch (minor) {
case SNDRV_MINOR_SEQUENCER: str = "snd-seq"; break;
case SNDRV_MINOR_TIMER: str = "snd-timer"; break;
default: return;
}
request_module(str);
}
#endif /* modular kernel */
/**
* 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);
#ifdef CONFIG_MODULES
static struct snd_minor *autoload_device(unsigned int minor)
{
int dev;
mutex_unlock(&sound_mutex); /* release lock temporarily */
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);
}
mutex_lock(&sound_mutex); /* reacuire lock */
return snd_minors[minor];
}
#else /* !CONFIG_MODULES */
#define autoload_device(minor) NULL
#endif /* CONFIG_MODULES */
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;
mutex_lock(&sound_mutex);
mptr = snd_minors[minor];
if (mptr == NULL) {
mptr = autoload_device(minor);
if (!mptr) {
mutex_unlock(&sound_mutex);
return -ENODEV;
}
}
old_fops = file->f_op;
file->f_op = fops_get(mptr->f_ops);
if (file->f_op == NULL) {
file->f_op = old_fops;
err = -ENODEV;
}
mutex_unlock(&sound_mutex);
if (err < 0)
return err;
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,
.llseek = noop_llseek,
};
#ifdef CONFIG_SND_DYNAMIC_MINORS
static int snd_find_free_minor(int type)
{
int minor;
/* static minors for module auto loading */
if (type == SNDRV_DEVICE_TYPE_SEQUENCER)
return SNDRV_MINOR_SEQUENCER;
if (type == SNDRV_DEVICE_TYPE_TIMER)
return SNDRV_MINOR_TIMER;
for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
/* skip static minors still used for module auto loading */
if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL)
continue;
if (minor == SNDRV_MINOR_SEQUENCER ||
minor == SNDRV_MINOR_TIMER)
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:
if (snd_BUG_ON(!card))
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:
case SNDRV_DEVICE_TYPE_COMPRESS:
if (snd_BUG_ON(!card))
return -EINVAL;
minor = SNDRV_MINOR(card->number, type + dev);
break;
default:
return -EINVAL;
}
if (snd_BUG_ON(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;
if (snd_BUG_ON(!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(type);
#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),
private_data, "%s", name);
if (IS_ERR(preg->dev)) {
snd_minors[minor] = NULL;
mutex_unlock(&sound_mutex);
minor = PTR_ERR(preg->dev);
kfree(preg);
return minor;
}
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 int find_snd_minor(int type, struct snd_card *card, int dev)
{
int cardnum, minor;
struct snd_minor *mptr;
cardnum = card ? card->number : -1;
for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor)
if ((mptr = snd_minors[minor]) != NULL &&
mptr->type == type &&
mptr->card == cardnum &&
mptr->device == dev)
return minor;
return -1;
}
/**
* snd_unregister_device - unregister the device on the given card
* @type: the device type, SNDRV_DEVICE_TYPE_XXX
* @card: the card instance
* @dev: the device index
*
* Unregisters the device file already registered via
* snd_register_device().
*
* Returns zero if sucecessful, or a negative error code on failure
*/
int snd_unregister_device(int type, struct snd_card *card, int dev)
{
int minor;
mutex_lock(&sound_mutex);
minor = find_snd_minor(type, card, dev);
if (minor < 0) {
mutex_unlock(&sound_mutex);
return -EINVAL;
}
device_destroy(sound_class, MKDEV(major, minor));
kfree(snd_minors[minor]);
snd_minors[minor] = NULL;
mutex_unlock(&sound_mutex);
return 0;
}
EXPORT_SYMBOL(snd_unregister_device);
int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev,
struct device_attribute *attr)
{
int minor, ret = -EINVAL;
struct device *d;
mutex_lock(&sound_mutex);
minor = find_snd_minor(type, card, dev);
if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL)
ret = device_create_file(d, attr);
mutex_unlock(&sound_mutex);
return ret;
}
EXPORT_SYMBOL(snd_add_device_sysfs_file);
#ifdef CONFIG_PROC_FS
/*
* INFO PART
*/
static struct snd_info_entry *snd_minor_info_entry;
static const char *snd_device_type_name(int type)
{
switch (type) {
case SNDRV_DEVICE_TYPE_CONTROL:
return "control";
case SNDRV_DEVICE_TYPE_HWDEP:
return "hardware dependent";
case SNDRV_DEVICE_TYPE_RAWMIDI:
return "raw midi";
case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
return "digital audio playback";
case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
return "digital audio capture";
case SNDRV_DEVICE_TYPE_SEQUENCER:
return "sequencer";
case SNDRV_DEVICE_TYPE_TIMER:
return "timer";
default:
return "?";
}
}
static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
{
int minor;
struct snd_minor *mptr;
mutex_lock(&sound_mutex);
for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
if (!(mptr = snd_minors[minor]))
continue;
if (mptr->card >= 0) {
if (mptr->device >= 0)
snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
minor, mptr->card, mptr->device,
snd_device_type_name(mptr->type));
else
snd_iprintf(buffer, "%3i: [%2i] : %s\n",
minor, mptr->card,
snd_device_type_name(mptr->type));
} else
snd_iprintf(buffer, "%3i: : %s\n", minor,
snd_device_type_name(mptr->type));
}
mutex_unlock(&sound_mutex);
}
int __init snd_minor_info_init(void)
{
struct snd_info_entry *entry;
entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
if (entry) {
entry->c.text.read = snd_minor_info_read;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
entry = NULL;
}
}
snd_minor_info_entry = entry;
return 0;
}
int __exit snd_minor_info_done(void)
{
snd_info_free_entry(snd_minor_info_entry);
return 0;
}
#endif /* CONFIG_PROC_FS */
/*
* INIT PART
*/
static int __init alsa_sound_init(void)
{
snd_major = major;
snd_ecards_limit = cards_limit;
if (register_chrdev(major, "alsa", &snd_fops)) {
snd_printk(KERN_ERR "unable to register native major device number %d\n", major);
return -EIO;
}
if (snd_info_init() < 0) {
unregister_chrdev(major, "alsa");
return -ENOMEM;
}
snd_info_minor_register();
#ifndef MODULE
printk(KERN_INFO "Advanced Linux Sound Architecture Driver Initialized.\n");
#endif
return 0;
}
static void __exit alsa_sound_exit(void)
{
snd_info_minor_unregister();
snd_info_done();
unregister_chrdev(major, "alsa");
}
subsys_initcall(alsa_sound_init);
module_exit(alsa_sound_exit);