/* * 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/smp_lock.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> 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); 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_MODULES 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 == NULL) { file->f_op = old_fops; return -ENODEV; } 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; } /* BKL pushdown: nasty #ifdef avoidance wrapper */ static int snd_open(struct inode *inode, struct file *file) { int ret; lock_kernel(); ret = __snd_open(inode, file); unlock_kernel(); return ret; } 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: 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: 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(); #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 Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\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);