core.c

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/*
 * Apple Onboard Audio driver core
 *
 * Copyright 2006 Johannes Berg <[email protected]>
 *
 * GPL v2, can be found in COPYING.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/list.h>
#include "../aoa.h"
#include "alsa.h"

MODULE_DESCRIPTION("Apple Onboard Audio Sound Driver");
MODULE_AUTHOR("Johannes Berg <[email protected]>");
MODULE_LICENSE("GPL");

/* We allow only one fabric. This simplifies things,
 * and more don't really make that much sense */
static struct aoa_fabric *fabric;
static LIST_HEAD(codec_list);

static int attach_codec_to_fabric(struct aoa_codec *c)
{
    int err;

    if (!try_module_get(c->owner))
        return -EBUSY;
    /* found_codec has to be assigned */
    err = -ENOENT;
    if (fabric->found_codec)
        err = fabric->found_codec(c);
    if (err) {
        module_put(c->owner);
        printk(KERN_ERR "snd-aoa: fabric didn't like codec %s\n",
                c->name);
        return err;
    }
    c->fabric = fabric;

    err = 0;
    if (c->init)
        err = c->init(c);
    if (err) {
        printk(KERN_ERR "snd-aoa: codec %s didn't init\n", c->name);
        c->fabric = NULL;
        if (fabric->remove_codec)
            fabric->remove_codec(c);
        module_put(c->owner);
        return err;
    }
    if (fabric->attached_codec)
        fabric->attached_codec(c);
    return 0;
}

int aoa_codec_register(struct aoa_codec *codec)
{
    int err = 0;

    /* if there's a fabric already, we can tell if we
     * will want to have this codec, so propagate error
     * through. Otherwise, this will happen later... */
    if (fabric)
        err = attach_codec_to_fabric(codec);
    if (!err)
        list_add(&codec->list, &codec_list);
    return err;
}
EXPORT_SYMBOL_GPL(aoa_codec_register);

void aoa_codec_unregister(struct aoa_codec *codec)
{
    list_del(&codec->list);
    if (codec->fabric && codec->exit)
        codec->exit(codec);
    if (fabric && fabric->remove_codec)
        fabric->remove_codec(codec);
    codec->fabric = NULL;
    module_put(codec->owner);
}
EXPORT_SYMBOL_GPL(aoa_codec_unregister);

int aoa_fabric_register(struct aoa_fabric *new_fabric, struct device *dev)
{
    struct aoa_codec *c;
    int err;

    /* allow querying for presence of fabric
     * (i.e. do this test first!) */
    if (new_fabric == fabric) {
        err = -EALREADY;
        goto attach;
    }
    if (fabric)
        return -EEXIST;
    if (!new_fabric)
        return -EINVAL;

    err = aoa_alsa_init(new_fabric->name, new_fabric->owner, dev);
    if (err)
        return err;

    fabric = new_fabric;

 attach:
    list_for_each_entry(c, &codec_list, list) {
        if (c->fabric != fabric)
            attach_codec_to_fabric(c);
    }
    return err;
}
EXPORT_SYMBOL_GPL(aoa_fabric_register);

void aoa_fabric_unregister(struct aoa_fabric *old_fabric)
{
    struct aoa_codec *c;

    if (fabric != old_fabric)
        return;

    list_for_each_entry(c, &codec_list, list) {
        if (c->fabric)
            aoa_fabric_unlink_codec(c);
    }

    aoa_alsa_cleanup();

    fabric = NULL;
}
EXPORT_SYMBOL_GPL(aoa_fabric_unregister);

void aoa_fabric_unlink_codec(struct aoa_codec *codec)
{
    if (!codec->fabric) {
        printk(KERN_ERR "snd-aoa: fabric unassigned "
                "in aoa_fabric_unlink_codec\n");
        dump_stack();
        return;
    }
    if (codec->exit)
        codec->exit(codec);
    if (codec->fabric->remove_codec)
        codec->fabric->remove_codec(codec);
    codec->fabric = NULL;
    module_put(codec->owner);
}
EXPORT_SYMBOL_GPL(aoa_fabric_unlink_codec);

static int __init aoa_init(void)
{
    return 0;
}

static void __exit aoa_exit(void)
{
    aoa_alsa_cleanup();
}

module_init(aoa_init);
module_exit(aoa_exit);