diff options
Diffstat (limited to 'sound/core/init.c')
| -rw-r--r-- | sound/core/init.c | 991 |
1 files changed, 991 insertions, 0 deletions
diff --git a/sound/core/init.c b/sound/core/init.c new file mode 100644 index 00000000..7b012d15 --- /dev/null +++ b/sound/core/init.c @@ -0,0 +1,991 @@ +/* + * 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 <linux/init.h> +#include <linux/sched.h> +#include <linux/module.h> +#include <linux/device.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> + +/* monitor files for graceful shutdown (hotplug) */ +struct snd_monitor_file { + struct file *file; + const struct file_operations *disconnected_f_op; + struct list_head shutdown_list; /* still need to shutdown */ + struct list_head list; /* link of monitor files */ +}; + +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 reserved for the given + * module via slots option + */ +static int module_slot_match(struct module *module, int idx) +{ + int match = 1; +#ifdef MODULE + const char *s1, *s2; + + if (!module || !module->name || !slots[idx]) + return 0; + + s1 = module->name; + s2 = slots[idx]; + if (*s2 == '!') { + match = 0; /* negative match */ + s2++; + } + /* 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 !match; + if (!c1) + break; + } +#endif /* MODULE */ + return match; +} + +#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_create - 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 + * @card_ret: the pointer to store the created card instance + * + * Creates and initializes a soundcard structure. + * + * The function allocates snd_card instance via kzalloc with the given + * space for the driver to use freely. The allocated struct is stored + * in the given card_ret pointer. + * + * Returns zero if successful or a negative error code. + */ +int snd_card_create(int idx, const char *xid, + struct module *module, int extra_size, + struct snd_card **card_ret) +{ + struct snd_card *card; + int err, idx2; + + if (snd_BUG_ON(!card_ret)) + return -EINVAL; + *card_ret = NULL; + + if (extra_size < 0) + extra_size = 0; + card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL); + if (!card) + return -ENOMEM; + if (xid) + strlcpy(card->id, xid, sizeof(card->id)); + err = 0; + mutex_lock(&snd_card_mutex); + if (idx < 0) { + 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_match(module, idx2)) { + idx = idx2; + break; + } + } + } + if (idx < 0) { + for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++) + /* idx == -1 == 0xffff means: take any free slot */ + if (~snd_cards_lock & idx & 1<<idx2) { + if (!slots[idx2] || !*slots[idx2]) { + idx = idx2; + break; + } + } + } + if (idx < 0) + err = -ENODEV; + else if (idx < snd_ecards_limit) { + if (snd_cards_lock & (1 << idx)) + err = -EBUSY; /* invalid */ + } else if (idx >= SNDRV_CARDS) + err = -ENODEV; + if (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 */ + if (idx >= snd_ecards_limit) + snd_ecards_limit = idx + 1; /* increase the limit */ + 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_LIST_HEAD(&card->files_list); + init_waitqueue_head(&card->shutdown_sleep); + atomic_set(&card->refcount, 0); +#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 */ + err = snd_ctl_create(card); + if (err < 0) { + snd_printk(KERN_ERR "unable to register control minors\n"); + goto __error; + } + err = snd_info_card_create(card); + if (err < 0) { + snd_printk(KERN_ERR "unable to create card info\n"); + goto __error_ctl; + } + if (extra_size > 0) + card->private_data = (char *)card + sizeof(struct snd_card); + *card_ret = card; + return 0; + + __error_ctl: + snd_device_free_all(card, SNDRV_DEV_CMD_PRE); + __error: + kfree(card); + return err; +} +EXPORT_SYMBOL(snd_card_create); + +/* 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; + list_del_init(&df->shutdown_list); + break; + } + } + spin_unlock(&shutdown_lock); + + if (likely(df)) { + if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync) + df->disconnected_f_op->fasync(-1, file, 0); + return df->disconnected_f_op->release(inode, file); + } + + panic("%s(%p, %p) failed!", __func__, 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; + int err; + + if (!card) + return -EINVAL; + + 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; + snd_cards_lock &= ~(1 << card->number); + mutex_unlock(&snd_card_mutex); + + /* phase 2: replace file->f_op with special dummy operations */ + + spin_lock(&card->files_lock); + list_for_each_entry(mfile, &card->files_list, list) { + /* 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); + + mfile->file->f_op = &snd_shutdown_f_ops; + fops_get(mfile->file->f_op); + } + 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); + if (card->card_dev) { + device_unregister(card->card_dev); + card->card_dev = NULL; + } +#ifdef CONFIG_PM + wake_up(&card->power_sleep); +#endif + 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 */ + } + kfree(card); + return 0; +} + +/** + * snd_card_unref - release the reference counter + * @card: the card instance + * + * Decrements the reference counter. When it reaches to zero, wake up + * the sleeper and call the destructor if needed. + */ +void snd_card_unref(struct snd_card *card) +{ + if (atomic_dec_and_test(&card->refcount)) { + wake_up(&card->shutdown_sleep); + if (card->free_on_last_close) + snd_card_do_free(card); + } +} +EXPORT_SYMBOL(snd_card_unref); + +int snd_card_free_when_closed(struct snd_card *card) +{ + int ret; + + atomic_inc(&card->refcount); + ret = snd_card_disconnect(card); + if (ret) { + atomic_dec(&card->refcount); + return ret; + } + + card->free_on_last_close = 1; + if (atomic_dec_and_test(&card->refcount)) + 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_disconnect(card); + if (ret) + return ret; + + /* wait, until all devices are ready for the free operation */ + wait_event(card->shutdown_sleep, !atomic_read(&card->refcount)); + snd_card_do_free(card); + return 0; +} + +EXPORT_SYMBOL(snd_card_free); + +/* retrieve the last word of shortname or longname */ +static const char *retrieve_id_from_card_name(const char *name) +{ + const char *spos = name; + + while (*name) { + if (isspace(*name) && isalnum(name[1])) + spos = name + 1; + name++; + } + return spos; +} + +/* return true if the given id string doesn't conflict any other card ids */ +static bool card_id_ok(struct snd_card *card, const char *id) +{ + int i; + if (!snd_info_check_reserved_words(id)) + return false; + for (i = 0; i < snd_ecards_limit; i++) { + if (snd_cards[i] && snd_cards[i] != card && + !strcmp(snd_cards[i]->id, id)) + return false; + } + return true; +} + +/* copy to card->id only with valid letters from nid */ +static void copy_valid_id_string(struct snd_card *card, const char *src, + const char *nid) +{ + char *id = card->id; + + while (*nid && !isalnum(*nid)) + nid++; + if (isdigit(*nid)) + *id++ = isalpha(*src) ? *src : 'D'; + while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) { + if (isalnum(*nid)) + *id++ = *nid; + nid++; + } + *id = 0; +} + +/* Set card->id from the given string + * If the string conflicts with other ids, add a suffix to make it unique. + */ +static void snd_card_set_id_no_lock(struct snd_card *card, const char *src, + const char *nid) +{ + int len, loops; + bool with_suffix; + bool is_default = false; + char *id; + + copy_valid_id_string(card, src, nid); + id = card->id; + + again: + /* use "Default" for obviously invalid strings + * ("card" conflicts with proc directories) + */ + if (!*id || !strncmp(id, "card", 4)) { + strcpy(id, "Default"); + is_default = true; + } + + with_suffix = false; + for (loops = 0; loops < SNDRV_CARDS; loops++) { + if (card_id_ok(card, id)) + return; /* OK */ + + len = strlen(id); + if (!with_suffix) { + /* add the "_X" suffix */ + char *spos = id + len; + if (len > sizeof(card->id) - 3) + spos = id + sizeof(card->id) - 3; + strcpy(spos, "_1"); + with_suffix = true; + } else { + /* modify the existing suffix */ + if (id[len - 1] != '9') + id[len - 1]++; + else + id[len - 1] = 'A'; + } + } + /* fallback to the default id */ + if (!is_default) { + *id = 0; + goto again; + } + /* last resort... */ + snd_printk(KERN_ERR "unable to set card id (%s)\n", id); + if (card->proc_root->name) + strcpy(card->id, card->proc_root->name); +} + +/** + * snd_card_set_id - set card identification name + * @card: soundcard structure + * @nid: new identification string + * + * This function sets the card identification and checks for name + * collisions. + */ +void snd_card_set_id(struct snd_card *card, const char *nid) +{ + /* check if user specified own card->id */ + if (card->id[0] != '\0') + return; + mutex_lock(&snd_card_mutex); + snd_card_set_id_no_lock(card, nid, nid); + mutex_unlock(&snd_card_mutex); +} +EXPORT_SYMBOL(snd_card_set_id); + +static ssize_t +card_id_show_attr(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct snd_card *card = dev_get_drvdata(dev); + return snprintf(buf, PAGE_SIZE, "%s\n", card ? card->id : "(null)"); +} + +static ssize_t +card_id_store_attr(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct snd_card *card = dev_get_drvdata(dev); + char buf1[sizeof(card->id)]; + size_t copy = count > sizeof(card->id) - 1 ? + sizeof(card->id) - 1 : count; + size_t idx; + int c; + + for (idx = 0; idx < copy; idx++) { + c = buf[idx]; + if (!isalnum(c) && c != '_' && c != '-') + return -EINVAL; + } + memcpy(buf1, buf, copy); + buf1[copy] = '\0'; + mutex_lock(&snd_card_mutex); + if (!card_id_ok(NULL, buf1)) { + mutex_unlock(&snd_card_mutex); + return -EEXIST; + } + strcpy(card->id, buf1); + snd_info_card_id_change(card); + mutex_unlock(&snd_card_mutex); + + return count; +} + +static struct device_attribute card_id_attrs = + __ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr); + +static ssize_t +card_number_show_attr(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct snd_card *card = dev_get_drvdata(dev); + return snprintf(buf, PAGE_SIZE, "%i\n", card ? card->number : -1); +} + +static struct device_attribute card_number_attrs = + __ATTR(number, S_IRUGO, card_number_show_attr, NULL); + +/** + * 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 registration failed. + */ +int snd_card_register(struct snd_card *card) +{ + int err; + + if (snd_BUG_ON(!card)) + return -EINVAL; + + if (!card->card_dev) { + card->card_dev = device_create(sound_class, card->dev, + MKDEV(0, 0), card, + "card%i", card->number); + if (IS_ERR(card->card_dev)) + card->card_dev = NULL; + } + + 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) { + /* make a unique id name from the given string */ + char tmpid[sizeof(card->id)]; + memcpy(tmpid, card->id, sizeof(card->id)); + snd_card_set_id_no_lock(card, tmpid, tmpid); + } else { + /* create an id from either shortname or longname */ + const char *src; + src = *card->shortname ? card->shortname : card->longname; + snd_card_set_id_no_lock(card, src, + retrieve_id_from_card_name(src)); + } + 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 + if (card->card_dev) { + err = device_create_file(card->card_dev, &card_id_attrs); + if (err < 0) + return err; + err = device_create_file(card->card_dev, &card_number_attrs); + if (err < 0) + return err; + } + + 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; + INIT_LIST_HEAD(&mfile->shutdown_list); + spin_lock(&card->files_lock); + if (card->shutdown) { + spin_unlock(&card->files_lock); + kfree(mfile); + return -ENODEV; + } + list_add(&mfile->list, &card->files_list); + atomic_inc(&card->refcount); + 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, *found = NULL; + + spin_lock(&card->files_lock); + list_for_each_entry(mfile, &card->files_list, list) { + if (mfile->file == file) { + list_del(&mfile->list); + spin_lock(&shutdown_lock); + list_del(&mfile->shutdown_list); + spin_unlock(&shutdown_lock); + if (mfile->disconnected_f_op) + fops_put(mfile->disconnected_f_op); + found = mfile; + break; + } + } + spin_unlock(&card->files_lock); + if (!found) { + snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file); + return -ENOENT; + } + kfree(found); + snd_card_unref(card); + 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 */ |