| /* |
| * Sound core. This file is composed of two parts. sound_class |
| * which is common to both OSS and ALSA and OSS sound core which |
| * is used OSS or emulation of it. |
| */ |
| |
| /* |
| * First, the common part. |
| */ |
| #include <linux/module.h> |
| #include <linux/device.h> |
| #include <linux/err.h> |
| #include <linux/kdev_t.h> |
| #include <linux/major.h> |
| #include <sound/core.h> |
| |
| #ifdef CONFIG_SOUND_OSS_CORE |
| static int __init init_oss_soundcore(void); |
| static void cleanup_oss_soundcore(void); |
| #else |
| static inline int init_oss_soundcore(void) { return 0; } |
| static inline void cleanup_oss_soundcore(void) { } |
| #endif |
| |
| struct class *sound_class; |
| EXPORT_SYMBOL(sound_class); |
| |
| MODULE_DESCRIPTION("Core sound module"); |
| MODULE_AUTHOR("Alan Cox"); |
| MODULE_LICENSE("GPL"); |
| |
| static char *sound_devnode(struct device *dev, umode_t *mode) |
| { |
| if (MAJOR(dev->devt) == SOUND_MAJOR) |
| return NULL; |
| return kasprintf(GFP_KERNEL, "snd/%s", dev_name(dev)); |
| } |
| |
| static int __init init_soundcore(void) |
| { |
| int rc; |
| |
| rc = init_oss_soundcore(); |
| if (rc) |
| return rc; |
| |
| sound_class = class_create(THIS_MODULE, "sound"); |
| if (IS_ERR(sound_class)) { |
| cleanup_oss_soundcore(); |
| return PTR_ERR(sound_class); |
| } |
| |
| sound_class->devnode = sound_devnode; |
| |
| return 0; |
| } |
| |
| static void __exit cleanup_soundcore(void) |
| { |
| cleanup_oss_soundcore(); |
| class_destroy(sound_class); |
| } |
| |
| subsys_initcall(init_soundcore); |
| module_exit(cleanup_soundcore); |
| |
| |
| #ifdef CONFIG_SOUND_OSS_CORE |
| /* |
| * OSS sound core handling. Breaks out sound functions to submodules |
| * |
| * Author: Alan Cox <alan@lxorguk.ukuu.org.uk> |
| * |
| * Fixes: |
| * |
| * |
| * 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. |
| * |
| * -------------------- |
| * |
| * Top level handler for the sound subsystem. Various devices can |
| * plug into this. The fact they don't all go via OSS doesn't mean |
| * they don't have to implement the OSS API. There is a lot of logic |
| * to keeping much of the OSS weight out of the code in a compatibility |
| * module, but it's up to the driver to rember to load it... |
| * |
| * The code provides a set of functions for registration of devices |
| * by type. This is done rather than providing a single call so that |
| * we can hide any future changes in the internals (eg when we go to |
| * 32bit dev_t) from the modules and their interface. |
| * |
| * Secondly we need to allocate the dsp, dsp16 and audio devices as |
| * one. Thus we misuse the chains a bit to simplify this. |
| * |
| * Thirdly to make it more fun and for 2.3.x and above we do all |
| * of this using fine grained locking. |
| * |
| * FIXME: we have to resolve modules and fine grained load/unload |
| * locking at some point in 2.3.x. |
| */ |
| |
| #include <linux/init.h> |
| #include <linux/slab.h> |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/sound.h> |
| #include <linux/kmod.h> |
| |
| #define SOUND_STEP 16 |
| |
| struct sound_unit |
| { |
| int unit_minor; |
| const struct file_operations *unit_fops; |
| struct sound_unit *next; |
| char name[32]; |
| }; |
| |
| #ifdef CONFIG_SOUND_MSNDCLAS |
| extern int msnd_classic_init(void); |
| #endif |
| #ifdef CONFIG_SOUND_MSNDPIN |
| extern int msnd_pinnacle_init(void); |
| #endif |
| |
| /* |
| * By default, OSS sound_core claims full legacy minor range (0-255) |
| * of SOUND_MAJOR to trap open attempts to any sound minor and |
| * requests modules using custom sound-slot/service-* module aliases. |
| * The only benefit of doing this is allowing use of custom module |
| * aliases instead of the standard char-major-* ones. This behavior |
| * prevents alternative OSS implementation and is scheduled to be |
| * removed. |
| * |
| * CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss kernel |
| * parameter are added to allow distros and developers to try and |
| * switch to alternative implementations without needing to rebuild |
| * the kernel in the meantime. If preclaim_oss is non-zero, the |
| * kernel will behave the same as before. All SOUND_MAJOR minors are |
| * preclaimed and the custom module aliases along with standard chrdev |
| * ones are emitted if a missing device is opened. If preclaim_oss is |
| * zero, sound_core only grabs what's actually in use and for missing |
| * devices only the standard chrdev aliases are requested. |
| * |
| * All these clutters are scheduled to be removed along with |
| * sound-slot/service-* module aliases. |
| */ |
| #ifdef CONFIG_SOUND_OSS_CORE_PRECLAIM |
| static int preclaim_oss = 1; |
| #else |
| static int preclaim_oss = 0; |
| #endif |
| |
| module_param(preclaim_oss, int, 0444); |
| |
| static int soundcore_open(struct inode *, struct file *); |
| |
| static const struct file_operations soundcore_fops = |
| { |
| /* We must have an owner or the module locking fails */ |
| .owner = THIS_MODULE, |
| .open = soundcore_open, |
| .llseek = noop_llseek, |
| }; |
| |
| /* |
| * Low level list operator. Scan the ordered list, find a hole and |
| * join into it. Called with the lock asserted |
| */ |
| |
| static int __sound_insert_unit(struct sound_unit * s, struct sound_unit **list, const struct file_operations *fops, int index, int low, int top) |
| { |
| int n=low; |
| |
| if (index < 0) { /* first free */ |
| |
| while (*list && (*list)->unit_minor<n) |
| list=&((*list)->next); |
| |
| while(n<top) |
| { |
| /* Found a hole ? */ |
| if(*list==NULL || (*list)->unit_minor>n) |
| break; |
| list=&((*list)->next); |
| n+=SOUND_STEP; |
| } |
| |
| if(n>=top) |
| return -ENOENT; |
| } else { |
| n = low+(index*16); |
| while (*list) { |
| if ((*list)->unit_minor==n) |
| return -EBUSY; |
| if ((*list)->unit_minor>n) |
| break; |
| list=&((*list)->next); |
| } |
| } |
| |
| /* |
| * Fill it in |
| */ |
| |
| s->unit_minor=n; |
| s->unit_fops=fops; |
| |
| /* |
| * Link it |
| */ |
| |
| s->next=*list; |
| *list=s; |
| |
| |
| return n; |
| } |
| |
| /* |
| * Remove a node from the chain. Called with the lock asserted |
| */ |
| |
| static struct sound_unit *__sound_remove_unit(struct sound_unit **list, int unit) |
| { |
| while(*list) |
| { |
| struct sound_unit *p=*list; |
| if(p->unit_minor==unit) |
| { |
| *list=p->next; |
| return p; |
| } |
| list=&(p->next); |
| } |
| printk(KERN_ERR "Sound device %d went missing!\n", unit); |
| return NULL; |
| } |
| |
| /* |
| * This lock guards the sound loader list. |
| */ |
| |
| static DEFINE_SPINLOCK(sound_loader_lock); |
| |
| /* |
| * Allocate the controlling structure and add it to the sound driver |
| * list. Acquires locks as needed |
| */ |
| |
| static int sound_insert_unit(struct sound_unit **list, const struct file_operations *fops, int index, int low, int top, const char *name, umode_t mode, struct device *dev) |
| { |
| struct sound_unit *s = kmalloc(sizeof(*s), GFP_KERNEL); |
| int r; |
| |
| if (!s) |
| return -ENOMEM; |
| |
| spin_lock(&sound_loader_lock); |
| retry: |
| r = __sound_insert_unit(s, list, fops, index, low, top); |
| spin_unlock(&sound_loader_lock); |
| |
| if (r < 0) |
| goto fail; |
| else if (r < SOUND_STEP) |
| sprintf(s->name, "sound/%s", name); |
| else |
| sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP); |
| |
| if (!preclaim_oss) { |
| /* |
| * Something else might have grabbed the minor. If |
| * first free slot is requested, rescan with @low set |
| * to the next unit; otherwise, -EBUSY. |
| */ |
| r = __register_chrdev(SOUND_MAJOR, s->unit_minor, 1, s->name, |
| &soundcore_fops); |
| if (r < 0) { |
| spin_lock(&sound_loader_lock); |
| __sound_remove_unit(list, s->unit_minor); |
| if (index < 0) { |
| low = s->unit_minor + SOUND_STEP; |
| goto retry; |
| } |
| spin_unlock(&sound_loader_lock); |
| r = -EBUSY; |
| goto fail; |
| } |
| } |
| |
| device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor), |
| NULL, "%s", s->name+6); |
| return s->unit_minor; |
| |
| fail: |
| kfree(s); |
| return r; |
| } |
| |
| /* |
| * Remove a unit. Acquires locks as needed. The drivers MUST have |
| * completed the removal before their file operations become |
| * invalid. |
| */ |
| |
| static void sound_remove_unit(struct sound_unit **list, int unit) |
| { |
| struct sound_unit *p; |
| |
| spin_lock(&sound_loader_lock); |
| p = __sound_remove_unit(list, unit); |
| spin_unlock(&sound_loader_lock); |
| if (p) { |
| if (!preclaim_oss) |
| __unregister_chrdev(SOUND_MAJOR, p->unit_minor, 1, |
| p->name); |
| device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor)); |
| kfree(p); |
| } |
| } |
| |
| /* |
| * Allocations |
| * |
| * 0 *16 Mixers |
| * 1 *8 Sequencers |
| * 2 *16 Midi |
| * 3 *16 DSP |
| * 4 *16 SunDSP |
| * 5 *16 DSP16 |
| * 6 -- sndstat (obsolete) |
| * 7 *16 unused |
| * 8 -- alternate sequencer (see above) |
| * 9 *16 raw synthesizer access |
| * 10 *16 unused |
| * 11 *16 unused |
| * 12 *16 unused |
| * 13 *16 unused |
| * 14 *16 unused |
| * 15 *16 unused |
| */ |
| |
| static struct sound_unit *chains[SOUND_STEP]; |
| |
| /** |
| * register_sound_special_device - register a special sound node |
| * @fops: File operations for the driver |
| * @unit: Unit number to allocate |
| * @dev: device pointer |
| * |
| * Allocate a special sound device by minor number from the sound |
| * subsystem. |
| * |
| * Return: The allocated number is returned on success. On failure, |
| * a negative error code is returned. |
| */ |
| |
| int register_sound_special_device(const struct file_operations *fops, int unit, |
| struct device *dev) |
| { |
| const int chain = unit % SOUND_STEP; |
| int max_unit = 256; |
| const char *name; |
| char _name[16]; |
| |
| switch (chain) { |
| case 0: |
| name = "mixer"; |
| break; |
| case 1: |
| name = "sequencer"; |
| if (unit >= SOUND_STEP) |
| goto __unknown; |
| max_unit = unit + 1; |
| break; |
| case 2: |
| name = "midi"; |
| break; |
| case 3: |
| name = "dsp"; |
| break; |
| case 4: |
| name = "audio"; |
| break; |
| case 5: |
| name = "dspW"; |
| break; |
| case 8: |
| name = "sequencer2"; |
| if (unit >= SOUND_STEP) |
| goto __unknown; |
| max_unit = unit + 1; |
| break; |
| case 9: |
| name = "dmmidi"; |
| break; |
| case 10: |
| name = "dmfm"; |
| break; |
| case 12: |
| name = "adsp"; |
| break; |
| case 13: |
| name = "amidi"; |
| break; |
| case 14: |
| name = "admmidi"; |
| break; |
| default: |
| { |
| __unknown: |
| sprintf(_name, "unknown%d", chain); |
| if (unit >= SOUND_STEP) |
| strcat(_name, "-"); |
| name = _name; |
| } |
| break; |
| } |
| return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit, |
| name, S_IRUSR | S_IWUSR, dev); |
| } |
| |
| EXPORT_SYMBOL(register_sound_special_device); |
| |
| int register_sound_special(const struct file_operations *fops, int unit) |
| { |
| return register_sound_special_device(fops, unit, NULL); |
| } |
| |
| EXPORT_SYMBOL(register_sound_special); |
| |
| /** |
| * register_sound_mixer - register a mixer device |
| * @fops: File operations for the driver |
| * @dev: Unit number to allocate |
| * |
| * Allocate a mixer device. Unit is the number of the mixer requested. |
| * Pass -1 to request the next free mixer unit. |
| * |
| * Return: On success, the allocated number is returned. On failure, |
| * a negative error code is returned. |
| */ |
| |
| int register_sound_mixer(const struct file_operations *fops, int dev) |
| { |
| return sound_insert_unit(&chains[0], fops, dev, 0, 128, |
| "mixer", S_IRUSR | S_IWUSR, NULL); |
| } |
| |
| EXPORT_SYMBOL(register_sound_mixer); |
| |
| /** |
| * register_sound_midi - register a midi device |
| * @fops: File operations for the driver |
| * @dev: Unit number to allocate |
| * |
| * Allocate a midi device. Unit is the number of the midi device requested. |
| * Pass -1 to request the next free midi unit. |
| * |
| * Return: On success, the allocated number is returned. On failure, |
| * a negative error code is returned. |
| */ |
| |
| int register_sound_midi(const struct file_operations *fops, int dev) |
| { |
| return sound_insert_unit(&chains[2], fops, dev, 2, 130, |
| "midi", S_IRUSR | S_IWUSR, NULL); |
| } |
| |
| EXPORT_SYMBOL(register_sound_midi); |
| |
| /* |
| * DSP's are registered as a triple. Register only one and cheat |
| * in open - see below. |
| */ |
| |
| /** |
| * register_sound_dsp - register a DSP device |
| * @fops: File operations for the driver |
| * @dev: Unit number to allocate |
| * |
| * Allocate a DSP device. Unit is the number of the DSP requested. |
| * Pass -1 to request the next free DSP unit. |
| * |
| * This function allocates both the audio and dsp device entries together |
| * and will always allocate them as a matching pair - eg dsp3/audio3 |
| * |
| * Return: On success, the allocated number is returned. On failure, |
| * a negative error code is returned. |
| */ |
| |
| int register_sound_dsp(const struct file_operations *fops, int dev) |
| { |
| return sound_insert_unit(&chains[3], fops, dev, 3, 131, |
| "dsp", S_IWUSR | S_IRUSR, NULL); |
| } |
| |
| EXPORT_SYMBOL(register_sound_dsp); |
| |
| /** |
| * unregister_sound_special - unregister a special sound device |
| * @unit: unit number to allocate |
| * |
| * Release a sound device that was allocated with |
| * register_sound_special(). The unit passed is the return value from |
| * the register function. |
| */ |
| |
| |
| void unregister_sound_special(int unit) |
| { |
| sound_remove_unit(&chains[unit % SOUND_STEP], unit); |
| } |
| |
| EXPORT_SYMBOL(unregister_sound_special); |
| |
| /** |
| * unregister_sound_mixer - unregister a mixer |
| * @unit: unit number to allocate |
| * |
| * Release a sound device that was allocated with register_sound_mixer(). |
| * The unit passed is the return value from the register function. |
| */ |
| |
| void unregister_sound_mixer(int unit) |
| { |
| sound_remove_unit(&chains[0], unit); |
| } |
| |
| EXPORT_SYMBOL(unregister_sound_mixer); |
| |
| /** |
| * unregister_sound_midi - unregister a midi device |
| * @unit: unit number to allocate |
| * |
| * Release a sound device that was allocated with register_sound_midi(). |
| * The unit passed is the return value from the register function. |
| */ |
| |
| void unregister_sound_midi(int unit) |
| { |
| sound_remove_unit(&chains[2], unit); |
| } |
| |
| EXPORT_SYMBOL(unregister_sound_midi); |
| |
| /** |
| * unregister_sound_dsp - unregister a DSP device |
| * @unit: unit number to allocate |
| * |
| * Release a sound device that was allocated with register_sound_dsp(). |
| * The unit passed is the return value from the register function. |
| * |
| * Both of the allocated units are released together automatically. |
| */ |
| |
| void unregister_sound_dsp(int unit) |
| { |
| sound_remove_unit(&chains[3], unit); |
| } |
| |
| |
| EXPORT_SYMBOL(unregister_sound_dsp); |
| |
| static struct sound_unit *__look_for_unit(int chain, int unit) |
| { |
| struct sound_unit *s; |
| |
| s=chains[chain]; |
| while(s && s->unit_minor <= unit) |
| { |
| if(s->unit_minor==unit) |
| return s; |
| s=s->next; |
| } |
| return NULL; |
| } |
| |
| static int soundcore_open(struct inode *inode, struct file *file) |
| { |
| int chain; |
| int unit = iminor(inode); |
| struct sound_unit *s; |
| const struct file_operations *new_fops = NULL; |
| |
| chain=unit&0x0F; |
| if(chain==4 || chain==5) /* dsp/audio/dsp16 */ |
| { |
| unit&=0xF0; |
| unit|=3; |
| chain=3; |
| } |
| |
| spin_lock(&sound_loader_lock); |
| s = __look_for_unit(chain, unit); |
| if (s) |
| new_fops = fops_get(s->unit_fops); |
| if (preclaim_oss && !new_fops) { |
| spin_unlock(&sound_loader_lock); |
| |
| /* |
| * Please, don't change this order or code. |
| * For ALSA slot means soundcard and OSS emulation code |
| * comes as add-on modules which aren't depend on |
| * ALSA toplevel modules for soundcards, thus we need |
| * load them at first. [Jaroslav Kysela <perex@jcu.cz>] |
| */ |
| request_module("sound-slot-%i", unit>>4); |
| request_module("sound-service-%i-%i", unit>>4, chain); |
| |
| /* |
| * sound-slot/service-* module aliases are scheduled |
| * for removal in favor of the standard char-major-* |
| * module aliases. For the time being, generate both |
| * the legacy and standard module aliases to ease |
| * transition. |
| */ |
| if (request_module("char-major-%d-%d", SOUND_MAJOR, unit) > 0) |
| request_module("char-major-%d", SOUND_MAJOR); |
| |
| spin_lock(&sound_loader_lock); |
| s = __look_for_unit(chain, unit); |
| if (s) |
| new_fops = fops_get(s->unit_fops); |
| } |
| spin_unlock(&sound_loader_lock); |
| if (new_fops) { |
| /* |
| * We rely upon the fact that we can't be unloaded while the |
| * subdriver is there. |
| */ |
| int err = 0; |
| replace_fops(file, new_fops); |
| |
| if (file->f_op->open) |
| err = file->f_op->open(inode,file); |
| |
| return err; |
| } |
| return -ENODEV; |
| } |
| |
| MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR); |
| |
| static void cleanup_oss_soundcore(void) |
| { |
| /* We have nothing to really do here - we know the lists must be |
| empty */ |
| unregister_chrdev(SOUND_MAJOR, "sound"); |
| } |
| |
| static int __init init_oss_soundcore(void) |
| { |
| if (preclaim_oss && |
| register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) == -1) { |
| printk(KERN_ERR "soundcore: sound device already in use.\n"); |
| return -EBUSY; |
| } |
| |
| return 0; |
| } |
| |
| #endif /* CONFIG_SOUND_OSS_CORE */ |