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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /sound/sound_core.c
downloadlinux-linaro-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'sound/sound_core.c')
-rw-r--r--sound/sound_core.c583
1 files changed, 583 insertions, 0 deletions
diff --git a/sound/sound_core.c b/sound/sound_core.c
new file mode 100644
index 00000000000..30f75c9288c
--- /dev/null
+++ b/sound/sound_core.c
@@ -0,0 +1,583 @@
+/*
+ * Sound core handling. Breaks out sound functions to submodules
+ *
+ * Author: Alan Cox <alan.cox@linux.org>
+ *
+ * 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/config.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/sound.h>
+#include <linux/major.h>
+#include <linux/kmod.h>
+#include <linux/devfs_fs_kernel.h>
+#include <linux/device.h>
+
+#define SOUND_STEP 16
+
+
+struct sound_unit
+{
+ int unit_minor;
+ 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
+
+struct class_simple *sound_class;
+EXPORT_SYMBOL(sound_class);
+
+/*
+ * 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_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, struct file_operations *fops, int index, int low, int top, const char *name, umode_t mode)
+{
+ struct sound_unit *s = kmalloc(sizeof(*s), GFP_KERNEL);
+ int r;
+
+ if (!s)
+ 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)
+ goto fail;
+ else if (r < SOUND_STEP)
+ sprintf(s->name, "sound/%s", name);
+ else
+ sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP);
+
+ devfs_mk_cdev(MKDEV(SOUND_MAJOR, s->unit_minor),
+ S_IFCHR | mode, s->name);
+ class_simple_device_add(sound_class, MKDEV(SOUND_MAJOR, s->unit_minor),
+ NULL, s->name+6);
+ return r;
+
+ 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) {
+ devfs_remove(p->name);
+ class_simple_device_remove(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 - 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)
+{
+ const int chain = unit % SOUND_STEP;
+ int max_unit = 128 + chain;
+ 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 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);
+}
+
+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 % 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)
+{
+ 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 = iminor(inode);
+ 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) {
+ 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);
+ 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");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);
+
+static void __exit cleanup_soundcore(void)
+{
+ /* We have nothing to really do here - we know the lists must be
+ empty */
+ unregister_chrdev(SOUND_MAJOR, "sound");
+ devfs_remove("sound");
+ class_simple_destroy(sound_class);
+}
+
+static int __init init_soundcore(void)
+{
+ if (register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops)==-1) {
+ printk(KERN_ERR "soundcore: sound device already in use.\n");
+ return -EBUSY;
+ }
+ devfs_mk_dir ("sound");
+ sound_class = class_simple_create(THIS_MODULE, "sound");
+ if (IS_ERR(sound_class))
+ return PTR_ERR(sound_class);
+
+ return 0;
+}
+
+module_init(init_soundcore);
+module_exit(cleanup_soundcore);