hwdep.c

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/*
 *  Hardware dependent layer
 *  Copyright (c) by Jaroslav Kysela <[email protected]>
 *
 *
 *   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 <linux/major.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/minors.h>
#include <sound/hwdep.h>
#include <sound/info.h>

MODULE_AUTHOR("Jaroslav Kysela <[email protected]>");
MODULE_DESCRIPTION("Hardware dependent layer");
MODULE_LICENSE("GPL");

static LIST_HEAD(snd_hwdep_devices);
static DEFINE_MUTEX(register_mutex);

static int snd_hwdep_free(struct snd_hwdep *hwdep);
static int snd_hwdep_dev_free(struct snd_device *device);
static int snd_hwdep_dev_register(struct snd_device *device);
static int snd_hwdep_dev_disconnect(struct snd_device *device);


static struct snd_hwdep *snd_hwdep_search(struct snd_card *card, int device)
{
    struct snd_hwdep *hwdep;

    list_for_each_entry(hwdep, &snd_hwdep_devices, list)
        if (hwdep->card == card && hwdep->device == device)
            return hwdep;
    return NULL;
}

static loff_t snd_hwdep_llseek(struct file * file, loff_t offset, int orig)
{
    struct snd_hwdep *hw = file->private_data;
    if (hw->ops.llseek)
        return hw->ops.llseek(hw, file, offset, orig);
    return -ENXIO;
}

static ssize_t snd_hwdep_read(struct file * file, char __user *buf,
                  size_t count, loff_t *offset)
{
    struct snd_hwdep *hw = file->private_data;
    if (hw->ops.read)
        return hw->ops.read(hw, buf, count, offset);
    return -ENXIO;  
}

static ssize_t snd_hwdep_write(struct file * file, const char __user *buf,
                   size_t count, loff_t *offset)
{
    struct snd_hwdep *hw = file->private_data;
    if (hw->ops.write)
        return hw->ops.write(hw, buf, count, offset);
    return -ENXIO;  
}

static int snd_hwdep_open(struct inode *inode, struct file * file)
{
    int major = imajor(inode);
    struct snd_hwdep *hw;
    int err;
    wait_queue_t wait;

    if (major == snd_major) {
        hw = snd_lookup_minor_data(iminor(inode),
                       SNDRV_DEVICE_TYPE_HWDEP);
#ifdef CONFIG_SND_OSSEMUL
    } else if (major == SOUND_MAJOR) {
        hw = snd_lookup_oss_minor_data(iminor(inode),
                           SNDRV_OSS_DEVICE_TYPE_DMFM);
#endif
    } else
        return -ENXIO;
    if (hw == NULL)
        return -ENODEV;

    if (!try_module_get(hw->card->module)) {
        snd_card_unref(hw->card);
        return -EFAULT;
    }

    init_waitqueue_entry(&wait, current);
    add_wait_queue(&hw->open_wait, &wait);
    mutex_lock(&hw->open_mutex);
    while (1) {
        if (hw->exclusive && hw->used > 0) {
            err = -EBUSY;
            break;
        }
        if (!hw->ops.open) {
            err = 0;
            break;
        }
        err = hw->ops.open(hw, file);
        if (err >= 0)
            break;
        if (err == -EAGAIN) {
            if (file->f_flags & O_NONBLOCK) {
                err = -EBUSY;
                break;
            }
        } else
            break;
        set_current_state(TASK_INTERRUPTIBLE);
        mutex_unlock(&hw->open_mutex);
        schedule();
        mutex_lock(&hw->open_mutex);
        if (hw->card->shutdown) {
            err = -ENODEV;
            break;
        }
        if (signal_pending(current)) {
            err = -ERESTARTSYS;
            break;
        }
    }
    remove_wait_queue(&hw->open_wait, &wait);
    if (err >= 0) {
        err = snd_card_file_add(hw->card, file);
        if (err >= 0) {
            file->private_data = hw;
            hw->used++;
        } else {
            if (hw->ops.release)
                hw->ops.release(hw, file);
        }
    }
    mutex_unlock(&hw->open_mutex);
    if (err < 0)
        module_put(hw->card->module);
    snd_card_unref(hw->card);
    return err;
}

static int snd_hwdep_release(struct inode *inode, struct file * file)
{
    int err = 0;
    struct snd_hwdep *hw = file->private_data;
    struct module *mod = hw->card->module;

    mutex_lock(&hw->open_mutex);
    if (hw->ops.release)
        err = hw->ops.release(hw, file);
    if (hw->used > 0)
        hw->used--;
    mutex_unlock(&hw->open_mutex);
    wake_up(&hw->open_wait);

    snd_card_file_remove(hw->card, file);
    module_put(mod);
    return err;
}

static unsigned int snd_hwdep_poll(struct file * file, poll_table * wait)
{
    struct snd_hwdep *hw = file->private_data;
    if (hw->ops.poll)
        return hw->ops.poll(hw, file, wait);
    return 0;
}

static int snd_hwdep_info(struct snd_hwdep *hw,
              struct snd_hwdep_info __user *_info)
{
    struct snd_hwdep_info info;
    
    memset(&info, 0, sizeof(info));
    info.card = hw->card->number;
    strlcpy(info.id, hw->id, sizeof(info.id));  
    strlcpy(info.name, hw->name, sizeof(info.name));
    info.iface = hw->iface;
    if (copy_to_user(_info, &info, sizeof(info)))
        return -EFAULT;
    return 0;
}

static int snd_hwdep_dsp_status(struct snd_hwdep *hw,
                struct snd_hwdep_dsp_status __user *_info)
{
    struct snd_hwdep_dsp_status info;
    int err;
    
    if (! hw->ops.dsp_status)
        return -ENXIO;
    memset(&info, 0, sizeof(info));
    info.dsp_loaded = hw->dsp_loaded;
    if ((err = hw->ops.dsp_status(hw, &info)) < 0)
        return err;
    if (copy_to_user(_info, &info, sizeof(info)))
        return -EFAULT;
    return 0;
}

static int snd_hwdep_dsp_load(struct snd_hwdep *hw,
                  struct snd_hwdep_dsp_image __user *_info)
{
    struct snd_hwdep_dsp_image info;
    int err;
    
    if (! hw->ops.dsp_load)
        return -ENXIO;
    memset(&info, 0, sizeof(info));
    if (copy_from_user(&info, _info, sizeof(info)))
        return -EFAULT;
    /* check whether the dsp was already loaded */
    if (hw->dsp_loaded & (1 << info.index))
        return -EBUSY;
    if (!access_ok(VERIFY_READ, info.image, info.length))
        return -EFAULT;
    err = hw->ops.dsp_load(hw, &info);
    if (err < 0)
        return err;
    hw->dsp_loaded |= (1 << info.index);
    return 0;
}

static long snd_hwdep_ioctl(struct file * file, unsigned int cmd,
                unsigned long arg)
{
    struct snd_hwdep *hw = file->private_data;
    void __user *argp = (void __user *)arg;
    switch (cmd) {
    case SNDRV_HWDEP_IOCTL_PVERSION:
        return put_user(SNDRV_HWDEP_VERSION, (int __user *)argp);
    case SNDRV_HWDEP_IOCTL_INFO:
        return snd_hwdep_info(hw, argp);
    case SNDRV_HWDEP_IOCTL_DSP_STATUS:
        return snd_hwdep_dsp_status(hw, argp);
    case SNDRV_HWDEP_IOCTL_DSP_LOAD:
        return snd_hwdep_dsp_load(hw, argp);
    }
    if (hw->ops.ioctl)
        return hw->ops.ioctl(hw, file, cmd, arg);
    return -ENOTTY;
}

static int snd_hwdep_mmap(struct file * file, struct vm_area_struct * vma)
{
    struct snd_hwdep *hw = file->private_data;
    if (hw->ops.mmap)
        return hw->ops.mmap(hw, file, vma);
    return -ENXIO;
}

static int snd_hwdep_control_ioctl(struct snd_card *card,
                   struct snd_ctl_file * control,
                   unsigned int cmd, unsigned long arg)
{
    switch (cmd) {
    case SNDRV_CTL_IOCTL_HWDEP_NEXT_DEVICE:
        {
            int device;

            if (get_user(device, (int __user *)arg))
                return -EFAULT;
            mutex_lock(&register_mutex);

            if (device < 0)
                device = 0;
            else if (device < SNDRV_MINOR_HWDEPS)
                device++;
            else
                device = SNDRV_MINOR_HWDEPS;

            while (device < SNDRV_MINOR_HWDEPS) {
                if (snd_hwdep_search(card, device))
                    break;
                device++;
            }
            if (device >= SNDRV_MINOR_HWDEPS)
                device = -1;
            mutex_unlock(&register_mutex);
            if (put_user(device, (int __user *)arg))
                return -EFAULT;
            return 0;
        }
    case SNDRV_CTL_IOCTL_HWDEP_INFO:
        {
            struct snd_hwdep_info __user *info = (struct snd_hwdep_info __user *)arg;
            int device, err;
            struct snd_hwdep *hwdep;

            if (get_user(device, &info->device))
                return -EFAULT;
            mutex_lock(&register_mutex);
            hwdep = snd_hwdep_search(card, device);
            if (hwdep)
                err = snd_hwdep_info(hwdep, info);
            else
                err = -ENXIO;
            mutex_unlock(&register_mutex);
            return err;
        }
    }
    return -ENOIOCTLCMD;
}

#ifdef CONFIG_COMPAT
#include "hwdep_compat.c"
#else
#define snd_hwdep_ioctl_compat  NULL
#endif

/*

 */

static const struct file_operations snd_hwdep_f_ops =
{
    .owner =    THIS_MODULE,
    .llseek =   snd_hwdep_llseek,
    .read =     snd_hwdep_read,
    .write =    snd_hwdep_write,
    .open =     snd_hwdep_open,
    .release =  snd_hwdep_release,
    .poll =     snd_hwdep_poll,
    .unlocked_ioctl =   snd_hwdep_ioctl,
    .compat_ioctl = snd_hwdep_ioctl_compat,
    .mmap =     snd_hwdep_mmap,
};

int snd_hwdep_new(struct snd_card *card, char *id, int device,
          struct snd_hwdep **rhwdep)
{
    struct snd_hwdep *hwdep;
    int err;
    static struct snd_device_ops ops = {
        .dev_free = snd_hwdep_dev_free,
        .dev_register = snd_hwdep_dev_register,
        .dev_disconnect = snd_hwdep_dev_disconnect,
    };

    if (snd_BUG_ON(!card))
        return -ENXIO;
    if (rhwdep)
        *rhwdep = NULL;
    hwdep = kzalloc(sizeof(*hwdep), GFP_KERNEL);
    if (hwdep == NULL) {
        snd_printk(KERN_ERR "hwdep: cannot allocate\n");
        return -ENOMEM;
    }
    hwdep->card = card;
    hwdep->device = device;
    if (id)
        strlcpy(hwdep->id, id, sizeof(hwdep->id));
#ifdef CONFIG_SND_OSSEMUL
    hwdep->oss_type = -1;
#endif
    if ((err = snd_device_new(card, SNDRV_DEV_HWDEP, hwdep, &ops)) < 0) {
        snd_hwdep_free(hwdep);
        return err;
    }
    init_waitqueue_head(&hwdep->open_wait);
    mutex_init(&hwdep->open_mutex);
    if (rhwdep)
        *rhwdep = hwdep;
    return 0;
}

static int snd_hwdep_free(struct snd_hwdep *hwdep)
{
    if (!hwdep)
        return 0;
    if (hwdep->private_free)
        hwdep->private_free(hwdep);
    kfree(hwdep);
    return 0;
}

static int snd_hwdep_dev_free(struct snd_device *device)
{
    struct snd_hwdep *hwdep = device->device_data;
    return snd_hwdep_free(hwdep);
}

static int snd_hwdep_dev_register(struct snd_device *device)
{
    struct snd_hwdep *hwdep = device->device_data;
    int err;
    char name[32];

    mutex_lock(&register_mutex);
    if (snd_hwdep_search(hwdep->card, hwdep->device)) {
        mutex_unlock(&register_mutex);
        return -EBUSY;
    }
    list_add_tail(&hwdep->list, &snd_hwdep_devices);
    sprintf(name, "hwC%iD%i", hwdep->card->number, hwdep->device);
    if ((err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,
                       hwdep->card, hwdep->device,
                       &snd_hwdep_f_ops, hwdep, name)) < 0) {
        snd_printk(KERN_ERR "unable to register hardware dependent device %i:%i\n",
               hwdep->card->number, hwdep->device);
        list_del(&hwdep->list);
        mutex_unlock(&register_mutex);
        return err;
    }
#ifdef CONFIG_SND_OSSEMUL
    hwdep->ossreg = 0;
    if (hwdep->oss_type >= 0) {
        if ((hwdep->oss_type == SNDRV_OSS_DEVICE_TYPE_DMFM) && (hwdep->device != 0)) {
            snd_printk (KERN_WARNING "only hwdep device 0 can be registered as OSS direct FM device!\n");
        } else {
            if (snd_register_oss_device(hwdep->oss_type,
                            hwdep->card, hwdep->device,
                            &snd_hwdep_f_ops, hwdep,
                            hwdep->oss_dev) < 0) {
                snd_printk(KERN_ERR "unable to register OSS compatibility device %i:%i\n",
                       hwdep->card->number, hwdep->device);
            } else
                hwdep->ossreg = 1;
        }
    }
#endif
    mutex_unlock(&register_mutex);
    return 0;
}

static int snd_hwdep_dev_disconnect(struct snd_device *device)
{
    struct snd_hwdep *hwdep = device->device_data;

    if (snd_BUG_ON(!hwdep))
        return -ENXIO;
    mutex_lock(&register_mutex);
    if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep) {
        mutex_unlock(&register_mutex);
        return -EINVAL;
    }
    mutex_lock(&hwdep->open_mutex);
    wake_up(&hwdep->open_wait);
#ifdef CONFIG_SND_OSSEMUL
    if (hwdep->ossreg)
        snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device);
#endif
    snd_unregister_device(SNDRV_DEVICE_TYPE_HWDEP, hwdep->card, hwdep->device);
    list_del_init(&hwdep->list);
    mutex_unlock(&hwdep->open_mutex);
    mutex_unlock(&register_mutex);
    return 0;
}

#ifdef CONFIG_PROC_FS
/*
 *  Info interface
 */

static void snd_hwdep_proc_read(struct snd_info_entry *entry,
                struct snd_info_buffer *buffer)
{
    struct snd_hwdep *hwdep;

    mutex_lock(&register_mutex);
    list_for_each_entry(hwdep, &snd_hwdep_devices, list)
        snd_iprintf(buffer, "%02i-%02i: %s\n",
                hwdep->card->number, hwdep->device, hwdep->name);
    mutex_unlock(&register_mutex);
}

static struct snd_info_entry *snd_hwdep_proc_entry;

static void __init snd_hwdep_proc_init(void)
{
    struct snd_info_entry *entry;

    if ((entry = snd_info_create_module_entry(THIS_MODULE, "hwdep", NULL)) != NULL) {
        entry->c.text.read = snd_hwdep_proc_read;
        if (snd_info_register(entry) < 0) {
            snd_info_free_entry(entry);
            entry = NULL;
        }
    }
    snd_hwdep_proc_entry = entry;
}

static void __exit snd_hwdep_proc_done(void)
{
    snd_info_free_entry(snd_hwdep_proc_entry);
}
#else /* !CONFIG_PROC_FS */
#define snd_hwdep_proc_init()
#define snd_hwdep_proc_done()
#endif /* CONFIG_PROC_FS */


/*
 *  ENTRY functions
 */

static int __init alsa_hwdep_init(void)
{
    snd_hwdep_proc_init();
    snd_ctl_register_ioctl(snd_hwdep_control_ioctl);
    snd_ctl_register_ioctl_compat(snd_hwdep_control_ioctl);
    return 0;
}

static void __exit alsa_hwdep_exit(void)
{
    snd_ctl_unregister_ioctl(snd_hwdep_control_ioctl);
    snd_ctl_unregister_ioctl_compat(snd_hwdep_control_ioctl);
    snd_hwdep_proc_done();
}

module_init(alsa_hwdep_init)
module_exit(alsa_hwdep_exit)

EXPORT_SYMBOL(snd_hwdep_new);