/* * Sound core handling. Breaks out sound functions to submodules * * Author: Alan Cox * * 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 dont 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 its 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 #include #include #include #include #include #include #include #include #include #include #define SOUND_STEP 16 struct sound_unit { int unit_minor; struct file_operations *unit_fops; struct sound_unit *next; devfs_handle_t de; }; #ifdef CONFIG_SOUND_MSNDCLAS extern int msnd_classic_init(void); #endif #ifdef CONFIG_SOUND_MSNDPIN extern int msnd_pinnacle_init(void); #endif /* * 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, struct file_operations *fops, int index, int low, int top) { int n=low; if (index < 0) { /* first free */ while (*list && (*list)->unit_minornext); while(nunit_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; MOD_INC_USE_COUNT; return n; } /* * Remove a node from the chain. Called with the lock asserted */ static void __sound_remove_unit(struct sound_unit **list, int unit) { while(*list) { struct sound_unit *p=*list; if(p->unit_minor==unit) { *list=p->next; devfs_unregister (p->de); kfree(p); MOD_DEC_USE_COUNT; return; } list=&(p->next); } printk(KERN_ERR "Sound device %d went missing!\n", unit); } /* * This lock guards the sound loader list. */ spinlock_t sound_loader_lock = SPIN_LOCK_UNLOCKED; /* * Allocate the controlling structure and add it to the sound driver * list. Acquires locks as needed */ static devfs_handle_t devfs_handle; static int sound_insert_unit(struct sound_unit **list, struct file_operations *fops, int index, int low, int top, const char *name, umode_t mode) { int r; struct sound_unit *s=(struct sound_unit *)kmalloc(sizeof(struct sound_unit), GFP_KERNEL); char name_buf[16]; if(s==NULL) return -ENOMEM; spin_lock(&sound_loader_lock); r=__sound_insert_unit(s,list,fops,index,low,top); spin_unlock(&sound_loader_lock); if(r<0) kfree(s); if (r == low) sprintf (name_buf, "%s", name); else sprintf (name_buf, "%s%d", name, (r - low) / SOUND_STEP); s->de = devfs_register (devfs_handle, name_buf, DEVFS_FL_NONE, SOUND_MAJOR, s->unit_minor, S_IFCHR | mode, fops, NULL); 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) { spin_lock(&sound_loader_lock); __sound_remove_unit(list, unit); spin_unlock(&sound_loader_lock); } /* * 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[16]; /** * register_sound_special - register a special sound node * @fops: File operations for the driver * @unit: Unit number to allocate * * Allocate a special sound device by minor number from the sound * subsystem. The allocated number is returned on succes. On failure * a negative error code is returned. */ int register_sound_special(struct file_operations *fops, int unit) { char *name; switch (unit) { case 0: name = "mixer"; break; case 1: name = "sequencer"; break; case 2: name = "midi00"; break; case 3: name = "dsp"; break; case 4: name = "audio"; break; case 5: name = "unknown5"; break; case 6: /* Was once sndstat */ name = "unknown6"; break; case 7: name = "unknown7"; break; case 8: name = "sequencer2"; break; case 9: name = "dmmidi"; break; case 10: name = "dmfm"; break; case 11: name = "unknown11"; break; case 12: name = "adsp"; break; case 13: name = "amidi"; break; case 14: name = "admmidi"; break; default: name = "unknown"; break; } return sound_insert_unit(&chains[unit&15], fops, -1, unit, unit+1, name, S_IRUSR | S_IWUSR); } 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. On success the allocated * number is returned, on failure a negative error code is returned. */ int register_sound_mixer(struct file_operations *fops, int dev) { return sound_insert_unit(&chains[0], fops, dev, 0, 128, "mixer", S_IRUSR | S_IWUSR); } 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. On success the allocated * number is returned, on failure a negative error code is returned. */ int register_sound_midi(struct file_operations *fops, int dev) { return sound_insert_unit(&chains[2], fops, dev, 2, 130, "midi", S_IRUSR | S_IWUSR); } 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. On success the allocated * number is returned, on failure a negative error code is returned. * * This function allocates both the audio and dsp device entries together * and will always allocate them as a matching pair - eg dsp3/audio3 */ int register_sound_dsp(struct file_operations *fops, int dev) { return sound_insert_unit(&chains[3], fops, dev, 3, 131, "dsp", S_IWUSR | S_IRUSR); } EXPORT_SYMBOL(register_sound_dsp); /** * register_sound_synth - register a synth device * @fops: File operations for the driver * @dev: Unit number to allocate * * Allocate a synth device. Unit is the number of the synth device requested. * Pass -1 to request the next free synth unit. On success the allocated * number is returned, on failure a negative error code is returned. */ int register_sound_synth(struct file_operations *fops, int dev) { return sound_insert_unit(&chains[9], fops, dev, 9, 137, "synth", S_IRUSR | S_IWUSR); } EXPORT_SYMBOL(register_sound_synth); /** * 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&15], 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) { return 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) { return sound_remove_unit(&chains[3], unit); } EXPORT_SYMBOL(unregister_sound_dsp); /** * unregister_sound_synth - unregister a synth device * @unit: unit number to allocate * * Release a sound device that was allocated with register_sound_synth(). * The unit passed is the return value from the register function. */ void unregister_sound_synth(int unit) { return sound_remove_unit(&chains[9], unit); } EXPORT_SYMBOL(unregister_sound_synth); /* * Now our file operations */ static int soundcore_open(struct inode *, struct file *); static struct file_operations soundcore_fops= { /* We must have an owner or the module locking fails */ owner: THIS_MODULE, open: soundcore_open, }; 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; } int soundcore_open(struct inode *inode, struct file *file) { int chain; int unit=MINOR(inode->i_rdev); struct sound_unit *s; 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 (!new_fops) { char mod[32]; 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 ] */ sprintf(mod, "sound-slot-%i", unit>>4); request_module(mod); sprintf(mod, "sound-service-%i-%i", unit>>4, chain); request_module(mod); spin_lock(&sound_loader_lock); s = __look_for_unit(chain, unit); if (s) new_fops = fops_get(s->unit_fops); } if (new_fops) { /* * We rely upon the fact that we can't be unloaded while the * subdriver is there, so if ->open() is successful we can * safely drop the reference counter and if it is not we can * revert to old ->f_op. Ugly, indeed, but that's the cost of * switching ->f_op in the first place. */ int err = 0; struct file_operations *old_fops = file->f_op; file->f_op = new_fops; spin_unlock(&sound_loader_lock); 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; } spin_unlock(&sound_loader_lock); return -ENODEV; } extern int mod_firmware_load(const char *, char **); EXPORT_SYMBOL(mod_firmware_load); MODULE_DESCRIPTION("Core sound module"); MODULE_AUTHOR("Alan Cox"); static void __exit cleanup_soundcore(void) { /* We have nothing to really do here - we know the lists must be empty */ devfs_unregister_chrdev(SOUND_MAJOR, "sound"); devfs_unregister (devfs_handle); } static int __init init_soundcore(void) { if(devfs_register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops)==-1) { printk(KERN_ERR "soundcore: sound device already in use.\n"); return -EBUSY; } devfs_handle = devfs_mk_dir (NULL, "sound", NULL); return 0; } module_init(init_soundcore); module_exit(cleanup_soundcore);