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linux/sound/core/init.c
Takashi Iwai 304cd07f92 [ALSA] Introduce slots option to snd module 
Introduced the global 'slots' option to snd module.  This option provides
an alternative way to handle the order of multiple sound card instances.
It's an easier approach to avoid conflict with hotplug devices, and can
be used together with the existing 'order' option of each card driver.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
2008-01-31 17:29:11 +01:00

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/*
* Initialization routines
* 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 <sound/driver.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/ctype.h>
#include <linux/pm.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/info.h>
static DEFINE_SPINLOCK(shutdown_lock);
static LIST_HEAD(shutdown_files);
static const struct file_operations snd_shutdown_f_ops;
static unsigned int snd_cards_lock; /* locked for registering/using */
struct snd_card *snd_cards[SNDRV_CARDS];
EXPORT_SYMBOL(snd_cards);
static DEFINE_MUTEX(snd_card_mutex);
static char *slots[SNDRV_CARDS];
module_param_array(slots, charp, NULL, 0444);
MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
/* return non-zero if the given index is already reserved for another
* module via slots option
*/
static int module_slot_mismatch(struct module *module, int idx)
{
#ifdef MODULE
char *s1, *s2;
if (!module || !module->name || !slots[idx])
return 0;
s1 = slots[idx];
s2 = module->name;
/* compare module name strings
* hyphens are handled as equivalent with underscore
*/
for (;;) {
char c1 = *s1++;
char c2 = *s2++;
if (c1 == '-')
c1 = '_';
if (c2 == '-')
c2 = '_';
if (c1 != c2)
return 1;
if (!c1)
break;
}
#endif
return 0;
}
#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
#endif
#ifdef CONFIG_PROC_FS
static void snd_card_id_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
snd_iprintf(buffer, "%s\n", entry->card->id);
}
static inline int init_info_for_card(struct snd_card *card)
{
int err;
struct snd_info_entry *entry;
if ((err = snd_info_card_register(card)) < 0) {
snd_printd("unable to create card info\n");
return err;
}
if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
snd_printd("unable to create card entry\n");
return err;
}
entry->c.text.read = snd_card_id_read;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
entry = NULL;
}
card->proc_id = entry;
return 0;
}
#else /* !CONFIG_PROC_FS */
#define init_info_for_card(card)
#endif
/**
* snd_card_new - create and initialize a soundcard structure
* @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
* @xid: card identification (ASCII string)
* @module: top level module for locking
* @extra_size: allocate this extra size after the main soundcard structure
*
* Creates and initializes a soundcard structure.
*
* Returns kmallocated snd_card structure. Creates the ALSA control interface
* (which is blocked until snd_card_register function is called).
*/
struct snd_card *snd_card_new(int idx, const char *xid,
struct module *module, int extra_size)
{
struct snd_card *card;
int err;
if (extra_size < 0)
extra_size = 0;
card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
if (card == NULL)
return NULL;
if (xid) {
if (!snd_info_check_reserved_words(xid))
goto __error;
strlcpy(card->id, xid, sizeof(card->id));
}
err = 0;
mutex_lock(&snd_card_mutex);
if (idx < 0) {
int idx2;
for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
/* idx == -1 == 0xffff means: take any free slot */
if (~snd_cards_lock & idx & 1<<idx2) {
if (module_slot_mismatch(module, idx2))
continue;
idx = idx2;
if (idx >= snd_ecards_limit)
snd_ecards_limit = idx + 1;
break;
}
} else {
if (idx < snd_ecards_limit) {
if (snd_cards_lock & (1 << idx))
err = -EBUSY; /* invalid */
} else {
if (idx < SNDRV_CARDS)
snd_ecards_limit = idx + 1; /* increase the limit */
else
err = -ENODEV;
}
}
if (idx < 0 || err < 0) {
mutex_unlock(&snd_card_mutex);
snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i), error: %d\n",
idx, snd_ecards_limit - 1, err);
goto __error;
}
snd_cards_lock |= 1 << idx; /* lock it */
mutex_unlock(&snd_card_mutex);
card->number = idx;
card->module = module;
INIT_LIST_HEAD(&card->devices);
init_rwsem(&card->controls_rwsem);
rwlock_init(&card->ctl_files_rwlock);
INIT_LIST_HEAD(&card->controls);
INIT_LIST_HEAD(&card->ctl_files);
spin_lock_init(&card->files_lock);
init_waitqueue_head(&card->shutdown_sleep);
#ifdef CONFIG_PM
mutex_init(&card->power_lock);
init_waitqueue_head(&card->power_sleep);
#endif
/* the control interface cannot be accessed from the user space until */
/* snd_cards_bitmask and snd_cards are set with snd_card_register */
if ((err = snd_ctl_create(card)) < 0) {
snd_printd("unable to register control minors\n");
goto __error;
}
if ((err = snd_info_card_create(card)) < 0) {
snd_printd("unable to create card info\n");
goto __error_ctl;
}
if (extra_size > 0)
card->private_data = (char *)card + sizeof(struct snd_card);
return card;
__error_ctl:
snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
__error:
kfree(card);
return NULL;
}
EXPORT_SYMBOL(snd_card_new);
/* return non-zero if a card is already locked */
int snd_card_locked(int card)
{
int locked;
mutex_lock(&snd_card_mutex);
locked = snd_cards_lock & (1 << card);
mutex_unlock(&snd_card_mutex);
return locked;
}
static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
{
return -ENODEV;
}
static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
size_t count, loff_t *offset)
{
return -ENODEV;
}
static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
size_t count, loff_t *offset)
{
return -ENODEV;
}
static int snd_disconnect_release(struct inode *inode, struct file *file)
{
struct snd_monitor_file *df = NULL, *_df;
spin_lock(&shutdown_lock);
list_for_each_entry(_df, &shutdown_files, shutdown_list) {
if (_df->file == file) {
df = _df;
break;
}
}
spin_unlock(&shutdown_lock);
if (likely(df))
return df->disconnected_f_op->release(inode, file);
panic("%s(%p, %p) failed!", __FUNCTION__, inode, file);
}
static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
{
return POLLERR | POLLNVAL;
}
static long snd_disconnect_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
return -ENODEV;
}
static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
{
return -ENODEV;
}
static int snd_disconnect_fasync(int fd, struct file *file, int on)
{
return -ENODEV;
}
static const struct file_operations snd_shutdown_f_ops =
{
.owner = THIS_MODULE,
.llseek = snd_disconnect_llseek,
.read = snd_disconnect_read,
.write = snd_disconnect_write,
.release = snd_disconnect_release,
.poll = snd_disconnect_poll,
.unlocked_ioctl = snd_disconnect_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = snd_disconnect_ioctl,
#endif
.mmap = snd_disconnect_mmap,
.fasync = snd_disconnect_fasync
};
/**
* snd_card_disconnect - disconnect all APIs from the file-operations (user space)
* @card: soundcard structure
*
* Disconnects all APIs from the file-operations (user space).
*
* Returns zero, otherwise a negative error code.
*
* Note: The current implementation replaces all active file->f_op with special
* dummy file operations (they do nothing except release).
*/
int snd_card_disconnect(struct snd_card *card)
{
struct snd_monitor_file *mfile;
struct file *file;
int err;
spin_lock(&card->files_lock);
if (card->shutdown) {
spin_unlock(&card->files_lock);
return 0;
}
card->shutdown = 1;
spin_unlock(&card->files_lock);
/* phase 1: disable fops (user space) operations for ALSA API */
mutex_lock(&snd_card_mutex);
snd_cards[card->number] = NULL;
mutex_unlock(&snd_card_mutex);
/* phase 2: replace file->f_op with special dummy operations */
spin_lock(&card->files_lock);
mfile = card->files;
while (mfile) {
file = mfile->file;
/* it's critical part, use endless loop */
/* we have no room to fail */
mfile->disconnected_f_op = mfile->file->f_op;
spin_lock(&shutdown_lock);
list_add(&mfile->shutdown_list, &shutdown_files);
spin_unlock(&shutdown_lock);
fops_get(&snd_shutdown_f_ops);
mfile->file->f_op = &snd_shutdown_f_ops;
mfile = mfile->next;
}
spin_unlock(&card->files_lock);
/* phase 3: notify all connected devices about disconnection */
/* at this point, they cannot respond to any calls except release() */
#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
if (snd_mixer_oss_notify_callback)
snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
#endif
/* notify all devices that we are disconnected */
err = snd_device_disconnect_all(card);
if (err < 0)
snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
snd_info_card_disconnect(card);
return 0;
}
EXPORT_SYMBOL(snd_card_disconnect);
/**
* snd_card_free - frees given soundcard structure
* @card: soundcard structure
*
* This function releases the soundcard structure and the all assigned
* devices automatically. That is, you don't have to release the devices
* by yourself.
*
* Returns zero. Frees all associated devices and frees the control
* interface associated to given soundcard.
*/
static int snd_card_do_free(struct snd_card *card)
{
#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
if (snd_mixer_oss_notify_callback)
snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
#endif
if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
snd_printk(KERN_ERR "unable to free all devices (pre)\n");
/* Fatal, but this situation should never occur */
}
if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
snd_printk(KERN_ERR "unable to free all devices (normal)\n");
/* Fatal, but this situation should never occur */
}
if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
snd_printk(KERN_ERR "unable to free all devices (post)\n");
/* Fatal, but this situation should never occur */
}
if (card->private_free)
card->private_free(card);
snd_info_free_entry(card->proc_id);
if (snd_info_card_free(card) < 0) {
snd_printk(KERN_WARNING "unable to free card info\n");
/* Not fatal error */
}
#ifndef CONFIG_SYSFS_DEPRECATED
if (card->card_dev)
device_unregister(card->card_dev);
#endif
kfree(card);
return 0;
}
static int snd_card_free_prepare(struct snd_card *card)
{
if (card == NULL)
return -EINVAL;
(void) snd_card_disconnect(card);
mutex_lock(&snd_card_mutex);
snd_cards[card->number] = NULL;
snd_cards_lock &= ~(1 << card->number);
mutex_unlock(&snd_card_mutex);
#ifdef CONFIG_PM
wake_up(&card->power_sleep);
#endif
return 0;
}
int snd_card_free_when_closed(struct snd_card *card)
{
int free_now = 0;
int ret = snd_card_free_prepare(card);
if (ret)
return ret;
spin_lock(&card->files_lock);
if (card->files == NULL)
free_now = 1;
else
card->free_on_last_close = 1;
spin_unlock(&card->files_lock);
if (free_now)
snd_card_do_free(card);
return 0;
}
EXPORT_SYMBOL(snd_card_free_when_closed);
int snd_card_free(struct snd_card *card)
{
int ret = snd_card_free_prepare(card);
if (ret)
return ret;
/* wait, until all devices are ready for the free operation */
wait_event(card->shutdown_sleep, card->files == NULL);
snd_card_do_free(card);
return 0;
}
EXPORT_SYMBOL(snd_card_free);
static void choose_default_id(struct snd_card *card)
{
int i, len, idx_flag = 0, loops = SNDRV_CARDS;
char *id, *spos;
id = spos = card->shortname;
while (*id != '\0') {
if (*id == ' ')
spos = id + 1;
id++;
}
id = card->id;
while (*spos != '\0' && !isalnum(*spos))
spos++;
if (isdigit(*spos))
*id++ = isalpha(card->shortname[0]) ? card->shortname[0] : 'D';
while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
if (isalnum(*spos))
*id++ = *spos;
spos++;
}
*id = '\0';
id = card->id;
if (*id == '\0')
strcpy(id, "default");
while (1) {
if (loops-- == 0) {
snd_printk(KERN_ERR "unable to choose default card id (%s)\n", id);
strcpy(card->id, card->proc_root->name);
return;
}
if (!snd_info_check_reserved_words(id))
goto __change;
for (i = 0; i < snd_ecards_limit; i++) {
if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
goto __change;
}
break;
__change:
len = strlen(id);
if (idx_flag) {
if (id[len-1] != '9')
id[len-1]++;
else
id[len-1] = 'A';
} else if ((size_t)len <= sizeof(card->id) - 3) {
strcat(id, "_1");
idx_flag++;
} else {
spos = id + len - 2;
if ((size_t)len <= sizeof(card->id) - 2)
spos++;
*spos++ = '_';
*spos++ = '1';
*spos++ = '\0';
idx_flag++;
}
}
}
/**
* snd_card_register - register the soundcard
* @card: soundcard structure
*
* This function registers all the devices assigned to the soundcard.
* Until calling this, the ALSA control interface is blocked from the
* external accesses. Thus, you should call this function at the end
* of the initialization of the card.
*
* Returns zero otherwise a negative error code if the registrain failed.
*/
int snd_card_register(struct snd_card *card)
{
int err;
snd_assert(card != NULL, return -EINVAL);
#ifndef CONFIG_SYSFS_DEPRECATED
if (!card->card_dev) {
card->card_dev = device_create(sound_class, card->dev, 0,
"card%i", card->number);
if (IS_ERR(card->card_dev))
card->card_dev = NULL;
}
#endif
if ((err = snd_device_register_all(card)) < 0)
return err;
mutex_lock(&snd_card_mutex);
if (snd_cards[card->number]) {
/* already registered */
mutex_unlock(&snd_card_mutex);
return 0;
}
if (card->id[0] == '\0')
choose_default_id(card);
snd_cards[card->number] = card;
mutex_unlock(&snd_card_mutex);
init_info_for_card(card);
#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
if (snd_mixer_oss_notify_callback)
snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
#endif
return 0;
}
EXPORT_SYMBOL(snd_card_register);
#ifdef CONFIG_PROC_FS
static struct snd_info_entry *snd_card_info_entry;
static void snd_card_info_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
int idx, count;
struct snd_card *card;
for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
mutex_lock(&snd_card_mutex);
if ((card = snd_cards[idx]) != NULL) {
count++;
snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
idx,
card->id,
card->driver,
card->shortname);
snd_iprintf(buffer, " %s\n",
card->longname);
}
mutex_unlock(&snd_card_mutex);
}
if (!count)
snd_iprintf(buffer, "--- no soundcards ---\n");
}
#ifdef CONFIG_SND_OSSEMUL
void snd_card_info_read_oss(struct snd_info_buffer *buffer)
{
int idx, count;
struct snd_card *card;
for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
mutex_lock(&snd_card_mutex);
if ((card = snd_cards[idx]) != NULL) {
count++;
snd_iprintf(buffer, "%s\n", card->longname);
}
mutex_unlock(&snd_card_mutex);
}
if (!count) {
snd_iprintf(buffer, "--- no soundcards ---\n");
}
}
#endif
#ifdef MODULE
static struct snd_info_entry *snd_card_module_info_entry;
static void snd_card_module_info_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
int idx;
struct snd_card *card;
for (idx = 0; idx < SNDRV_CARDS; idx++) {
mutex_lock(&snd_card_mutex);
if ((card = snd_cards[idx]) != NULL)
snd_iprintf(buffer, "%2i %s\n",
idx, card->module->name);
mutex_unlock(&snd_card_mutex);
}
}
#endif
int __init snd_card_info_init(void)
{
struct snd_info_entry *entry;
entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
if (! entry)
return -ENOMEM;
entry->c.text.read = snd_card_info_read;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
return -ENOMEM;
}
snd_card_info_entry = entry;
#ifdef MODULE
entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
if (entry) {
entry->c.text.read = snd_card_module_info_read;
if (snd_info_register(entry) < 0)
snd_info_free_entry(entry);
else
snd_card_module_info_entry = entry;
}
#endif
return 0;
}
int __exit snd_card_info_done(void)
{
snd_info_free_entry(snd_card_info_entry);
#ifdef MODULE
snd_info_free_entry(snd_card_module_info_entry);
#endif
return 0;
}
#endif /* CONFIG_PROC_FS */
/**
* snd_component_add - add a component string
* @card: soundcard structure
* @component: the component id string
*
* This function adds the component id string to the supported list.
* The component can be referred from the alsa-lib.
*
* Returns zero otherwise a negative error code.
*/
int snd_component_add(struct snd_card *card, const char *component)
{
char *ptr;
int len = strlen(component);
ptr = strstr(card->components, component);
if (ptr != NULL) {
if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
return 1;
}
if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
snd_BUG();
return -ENOMEM;
}
if (card->components[0] != '\0')
strcat(card->components, " ");
strcat(card->components, component);
return 0;
}
EXPORT_SYMBOL(snd_component_add);
/**
* snd_card_file_add - add the file to the file list of the card
* @card: soundcard structure
* @file: file pointer
*
* This function adds the file to the file linked-list of the card.
* This linked-list is used to keep tracking the connection state,
* and to avoid the release of busy resources by hotplug.
*
* Returns zero or a negative error code.
*/
int snd_card_file_add(struct snd_card *card, struct file *file)
{
struct snd_monitor_file *mfile;
mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
if (mfile == NULL)
return -ENOMEM;
mfile->file = file;
mfile->disconnected_f_op = NULL;
mfile->next = NULL;
spin_lock(&card->files_lock);
if (card->shutdown) {
spin_unlock(&card->files_lock);
kfree(mfile);
return -ENODEV;
}
mfile->next = card->files;
card->files = mfile;
spin_unlock(&card->files_lock);
return 0;
}
EXPORT_SYMBOL(snd_card_file_add);
/**
* snd_card_file_remove - remove the file from the file list
* @card: soundcard structure
* @file: file pointer
*
* This function removes the file formerly added to the card via
* snd_card_file_add() function.
* If all files are removed and snd_card_free_when_closed() was
* called beforehand, it processes the pending release of
* resources.
*
* Returns zero or a negative error code.
*/
int snd_card_file_remove(struct snd_card *card, struct file *file)
{
struct snd_monitor_file *mfile, *pfile = NULL;
int last_close = 0;
spin_lock(&card->files_lock);
mfile = card->files;
while (mfile) {
if (mfile->file == file) {
if (pfile)
pfile->next = mfile->next;
else
card->files = mfile->next;
break;
}
pfile = mfile;
mfile = mfile->next;
}
if (mfile && mfile->disconnected_f_op) {
fops_put(mfile->disconnected_f_op);
spin_lock(&shutdown_lock);
list_del(&mfile->shutdown_list);
spin_unlock(&shutdown_lock);
}
if (card->files == NULL)
last_close = 1;
spin_unlock(&card->files_lock);
if (last_close) {
wake_up(&card->shutdown_sleep);
if (card->free_on_last_close)
snd_card_do_free(card);
}
if (!mfile) {
snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
return -ENOENT;
}
kfree(mfile);
return 0;
}
EXPORT_SYMBOL(snd_card_file_remove);
#ifdef CONFIG_PM
/**
* snd_power_wait - wait until the power-state is changed.
* @card: soundcard structure
* @power_state: expected power state
*
* Waits until the power-state is changed.
*
* Note: the power lock must be active before call.
*/
int snd_power_wait(struct snd_card *card, unsigned int power_state)
{
wait_queue_t wait;
int result = 0;
/* fastpath */
if (snd_power_get_state(card) == power_state)
return 0;
init_waitqueue_entry(&wait, current);
add_wait_queue(&card->power_sleep, &wait);
while (1) {
if (card->shutdown) {
result = -ENODEV;
break;
}
if (snd_power_get_state(card) == power_state)
break;
set_current_state(TASK_UNINTERRUPTIBLE);
snd_power_unlock(card);
schedule_timeout(30 * HZ);
snd_power_lock(card);
}
remove_wait_queue(&card->power_sleep, &wait);
return result;
}
EXPORT_SYMBOL(snd_power_wait);
#endif /* CONFIG_PM */
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