Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 625 insertions, 0 deletions

diff --git a/sound/sound_core.c b/sound/sound_core.c
new file mode 100644
index 000000000..dd64c4b19
--- /dev/null
+++ b/sound/sound_core.c
@@ -0,0 +1,625 @@
+/*
+ *	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];
+};
+
+/*
+ * 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, 0600, 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", 0600, NULL);
+}
+
+EXPORT_SYMBOL(register_sound_mixer);
+
+/*
+ *	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", 0600, 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_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) < 0) {
+		printk(KERN_ERR "soundcore: sound device already in use.\n");
+		return -EBUSY;
+	}
+
+	return 0;
+}
+
+#endif /* CONFIG_SOUND_OSS_CORE */