Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 *  Advanced Linux Sound Architecture

 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>

 *

 *

 *   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.

 *

 *   This program is distributed in the hope that it will be useful,

 *   but WITHOUT ANY WARRANTY; without even the implied warranty of

 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *   GNU General Public License for more details.

 *

 *   You should have received a copy of the GNU General Public License

 *   along with this program; if not, write to the Free Software

 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA

 *

 */

#include <sound/driver.h>

#include <linux/init.h>

#include <linux/slab.h>

#include <linux/time.h>

#include <linux/device.h>

#include <linux/moduleparam.h>

#include <sound/core.h>

#include <sound/minors.h>

#include <sound/info.h>

#include <sound/version.h>

#include <sound/control.h>

#include <sound/initval.h>

#include <linux/kmod.h>

#include <linux/mutex.h>

#define SNDRV_OS_MINORS 256

static int major = CONFIG_SND_MAJOR;

int snd_major;

EXPORT_SYMBOL(snd_major);

static int cards_limit = 1;

MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");

MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");

MODULE_LICENSE("GPL");

module_param(major, int, 0444);

MODULE_PARM_DESC(major, "Major # for sound driver.");

module_param(cards_limit, int, 0444);

MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");

MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);

/* this one holds the actual max. card number currently available.

 * as default, it's identical with cards_limit option.  when more

 * modules are loaded manually, this limit number increases, too.

 */

int snd_ecards_limit;

EXPORT_SYMBOL(snd_ecards_limit);

static struct snd_minor *snd_minors[SNDRV_OS_MINORS];

static DEFINE_MUTEX(sound_mutex);

#ifdef CONFIG_KMOD

/**

 * snd_request_card - try to load the card module

 * @card: the card number

 *

 * Tries to load the module "snd-card-X" for the given card number

 * via KMOD.  Returns immediately if already loaded.

 */

void snd_request_card(int card)

{

        if (! current->fs->root)

                return;

        if (snd_card_locked(card))

                return;

        if (card < 0 || card >= cards_limit)

                return;

        request_module("snd-card-%i", card);

}

EXPORT_SYMBOL(snd_request_card);

static void snd_request_other(int minor)

{

        char *str;

        if (! current->fs->root)

                return;

        switch (minor) {

        case SNDRV_MINOR_SEQUENCER:     str = "snd-seq";        break;

        case SNDRV_MINOR_TIMER:         str = "snd-timer";      break;

        default:                        return;

        }

        request_module(str);

}

#endif                          /* request_module support */

/**

 * snd_lookup_minor_data - get user data of a registered device

 * @minor: the minor number

 * @type: device type (SNDRV_DEVICE_TYPE_XXX)

 *

 * Checks that a minor device with the specified type is registered, and returns

 * its user data pointer.

 */

void *snd_lookup_minor_data(unsigned int minor, int type)

{

        struct snd_minor *mreg;

        void *private_data;

        if (minor >= ARRAY_SIZE(snd_minors))

                return NULL;

        mutex_lock(&sound_mutex);

        mreg = snd_minors[minor];

        if (mreg && mreg->type == type)

                private_data = mreg->private_data;

        else

                private_data = NULL;

        mutex_unlock(&sound_mutex);

        return private_data;

}

EXPORT_SYMBOL(snd_lookup_minor_data);

static int snd_open(struct inode *inode, struct file *file)

{

        unsigned int minor = iminor(inode);

        struct snd_minor *mptr = NULL;

        const struct file_operations *old_fops;

        int err = 0;

        if (minor >= ARRAY_SIZE(snd_minors))

                return -ENODEV;

        mptr = snd_minors[minor];

        if (mptr == NULL) {

#ifdef CONFIG_KMOD

                int dev = SNDRV_MINOR_DEVICE(minor);

                if (dev == SNDRV_MINOR_CONTROL) {

                        /* /dev/aloadC? */

                        int card = SNDRV_MINOR_CARD(minor);

                        if (snd_cards[card] == NULL)

                                snd_request_card(card);

                } else if (dev == SNDRV_MINOR_GLOBAL) {

                        /* /dev/aloadSEQ */

                        snd_request_other(minor);

                }

#ifndef CONFIG_SND_DYNAMIC_MINORS

                /* /dev/snd/{controlC?,seq} */

                mptr = snd_minors[minor];

                if (mptr == NULL)

#endif

#endif

                        return -ENODEV;

        }

        old_fops = file->f_op;

        file->f_op = fops_get(mptr->f_ops);

        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;

}

static const struct file_operations snd_fops =

{

        .owner =        THIS_MODULE,

        .open =         snd_open

};

#ifdef CONFIG_SND_DYNAMIC_MINORS

static int snd_find_free_minor(void)

{

        int minor;

        for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {

                /* skip minors still used statically for autoloading devices */

                if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL ||

                    minor == SNDRV_MINOR_SEQUENCER)

                        continue;

                if (!snd_minors[minor])

                        return minor;

        }

        return -EBUSY;

}

#else

static int snd_kernel_minor(int type, struct snd_card *card, int dev)

{

        int minor;

        switch (type) {

        case SNDRV_DEVICE_TYPE_SEQUENCER:

        case SNDRV_DEVICE_TYPE_TIMER:

                minor = type;

                break;

        case SNDRV_DEVICE_TYPE_CONTROL:

                snd_assert(card != NULL, return -EINVAL);

                minor = SNDRV_MINOR(card->number, type);

                break;

        case SNDRV_DEVICE_TYPE_HWDEP:

        case SNDRV_DEVICE_TYPE_RAWMIDI:

        case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:

        case SNDRV_DEVICE_TYPE_PCM_CAPTURE:

                snd_assert(card != NULL, return -EINVAL);

                minor = SNDRV_MINOR(card->number, type + dev);

                break;

        default:

                return -EINVAL;

        }

        snd_assert(minor >= 0 && minor < SNDRV_OS_MINORS, return -EINVAL);

        return minor;

}

#endif

/**

 * snd_register_device_for_dev - Register the ALSA device file for the card

 * @type: the device type, SNDRV_DEVICE_TYPE_XXX

 * @card: the card instance

 * @dev: the device index

 * @f_ops: the file operations

 * @private_data: user pointer for f_ops->open()

 * @name: the device file name

 * @device: the &struct device to link this new device to

 *

 * Registers an ALSA device file for the given card.

 * The operators have to be set in reg parameter.

 *

 * Returns zero if successful, or a negative error code on failure.

 */

int snd_register_device_for_dev(int type, struct snd_card *card, int dev,

                                const struct file_operations *f_ops,

                                void *private_data,

                                const char *name, struct device *device)

{

        int minor;

        struct snd_minor *preg;

        snd_assert(name, return -EINVAL);

        preg = kmalloc(sizeof *preg, GFP_KERNEL);

        if (preg == NULL)

                return -ENOMEM;

        preg->type = type;

        preg->card = card ? card->number : -1;

        preg->device = dev;

        preg->f_ops = f_ops;

        preg->private_data = private_data;

        mutex_lock(&sound_mutex);

#ifdef CONFIG_SND_DYNAMIC_MINORS

        minor = snd_find_free_minor();

#else

        minor = snd_kernel_minor(type, card, dev);

        if (minor >= 0 && snd_minors[minor])

                minor = -EBUSY;

#endif

        if (minor < 0) {

                mutex_unlock(&sound_mutex);

                kfree(preg);

                return minor;

        }

        snd_minors[minor] = preg;

        preg->dev = device_create(sound_class, device, MKDEV(major, minor),

                                  "%s", name);

        if (IS_ERR(preg->dev)) {

                snd_minors[minor] = NULL;

                mutex_unlock(&sound_mutex);

                minor = PTR_ERR(preg->dev);

                kfree(preg);

                return minor;

        }

        if (preg->dev)

                dev_set_drvdata(preg->dev, private_data);

        mutex_unlock(&sound_mutex);

        return 0;

}

EXPORT_SYMBOL(snd_register_device_for_dev);

/* find the matching minor record

 * return the index of snd_minor, or -1 if not found

 */

static int find_snd_minor(int type, struct snd_card *card, int dev)

{

        int cardnum, minor;

        struct snd_minor *mptr;

        cardnum = card ? card->number : -1;

        for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor)

                if ((mptr = snd_minors[minor]) != NULL &&

                    mptr->type == type &&

                    mptr->card == cardnum &&

                    mptr->device == dev)

                        return minor;

        return -1;

}

/**

 * snd_unregister_device - unregister the device on the given card

 * @type: the device type, SNDRV_DEVICE_TYPE_XXX

 * @card: the card instance

 * @dev: the device index

 *

 * Unregisters the device file already registered via

 * snd_register_device().

 *

 * Returns zero if sucecessful, or a negative error code on failure

 */

int snd_unregister_device(int type, struct snd_card *card, int dev)

{

        int minor;

        mutex_lock(&sound_mutex);

        minor = find_snd_minor(type, card, dev);

        if (minor < 0) {

                mutex_unlock(&sound_mutex);

                return -EINVAL;

        }

        device_destroy(sound_class, MKDEV(major, minor));

        kfree(snd_minors[minor]);

        snd_minors[minor] = NULL;

        mutex_unlock(&sound_mutex);

        return 0;

}

EXPORT_SYMBOL(snd_unregister_device);

int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev,

                              struct device_attribute *attr)

{

        int minor, ret = -EINVAL;

        struct device *d;

        mutex_lock(&sound_mutex);

        minor = find_snd_minor(type, card, dev);

        if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL)

                ret = device_create_file(d, attr);

        mutex_unlock(&sound_mutex);

        return ret;

}

EXPORT_SYMBOL(snd_add_device_sysfs_file);

#ifdef CONFIG_PROC_FS

/*

 *  INFO PART

 */

static struct snd_info_entry *snd_minor_info_entry;

static const char *snd_device_type_name(int type)

{

        switch (type) {

        case SNDRV_DEVICE_TYPE_CONTROL:

                return "control";

        case SNDRV_DEVICE_TYPE_HWDEP:

                return "hardware dependent";

        case SNDRV_DEVICE_TYPE_RAWMIDI:

                return "raw midi";

        case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:

                return "digital audio playback";

        case SNDRV_DEVICE_TYPE_PCM_CAPTURE:

                return "digital audio capture";

        case SNDRV_DEVICE_TYPE_SEQUENCER:

                return "sequencer";

        case SNDRV_DEVICE_TYPE_TIMER:

                return "timer";

        default:

                return "?";

        }

}

static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)

{

        int minor;

        struct snd_minor *mptr;

        mutex_lock(&sound_mutex);

        for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {

                if (!(mptr = snd_minors[minor]))

                        continue;

                if (mptr->card >= 0) {

                        if (mptr->device >= 0)

                                snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",

                                            minor, mptr->card, mptr->device,

                                            snd_device_type_name(mptr->type));

                        else

                                snd_iprintf(buffer, "%3i: [%2i]   : %s\n",

                                            minor, mptr->card,

                                            snd_device_type_name(mptr->type));

                } else

                        snd_iprintf(buffer, "%3i:        : %s\n", minor,

                                    snd_device_type_name(mptr->type));

        }

        mutex_unlock(&sound_mutex);

}

int __init snd_minor_info_init(void)

{

        struct snd_info_entry *entry;

        entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);

        if (entry) {

                entry->c.text.read = snd_minor_info_read;

                if (snd_info_register(entry) < 0) {

                        snd_info_free_entry(entry);

                        entry = NULL;

                }

        }

        snd_minor_info_entry = entry;

        return 0;

}

int __exit snd_minor_info_done(void)

{

        snd_info_free_entry(snd_minor_info_entry);

        return 0;

}

#endif /* CONFIG_PROC_FS */

/*

 *  INIT PART

 */

static int __init alsa_sound_init(void)

{

        snd_major = major;

        snd_ecards_limit = cards_limit;

        if (register_chrdev(major, "alsa", &snd_fops)) {

                snd_printk(KERN_ERR "unable to register native major device number %d\n", major);

                return -EIO;

        }

        if (snd_info_init() < 0) {

                unregister_chrdev(major, "alsa");

                return -ENOMEM;

        }

        snd_info_minor_register();

#ifndef MODULE

        printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");

#endif

        return 0;

}

static void __exit alsa_sound_exit(void)

{

        snd_info_minor_unregister();

        snd_info_done();

        unregister_chrdev(major, "alsa");

}

module_init(alsa_sound_init)

module_exit(alsa_sound_exit)