root/sound/core/oss/mixer_oss.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  OSS emulation layer for the mixer interface
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/string.h>
#include <linux/module.h>
#include <linux/compat.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/control.h>
#include <sound/info.h>
#include <sound/mixer_oss.h>
#include <linux/soundcard.h>

#define OSS_ALSAEMULVER         _SIOR ('M', 249, int)

MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
MODULE_DESCRIPTION("Mixer OSS emulation for ALSA.");
MODULE_LICENSE("GPL");
MODULE_ALIAS_SNDRV_MINOR(SNDRV_MINOR_OSS_MIXER);

static int snd_mixer_oss_open(struct inode *inode, struct file *file)
{
        struct snd_card *card;
        struct snd_mixer_oss_file *fmixer;
        int err;

        err = nonseekable_open(inode, file);
        if (err < 0)
                return err;

        card = snd_lookup_oss_minor_data(iminor(inode),
                                         SNDRV_OSS_DEVICE_TYPE_MIXER);
        if (card == NULL)
                return -ENODEV;
        if (card->mixer_oss == NULL) {
                snd_card_unref(card);
                return -ENODEV;
        }
        err = snd_card_file_add(card, file);
        if (err < 0) {
                snd_card_unref(card);
                return err;
        }
        fmixer = kzalloc_obj(*fmixer);
        if (fmixer == NULL) {
                snd_card_file_remove(card, file);
                snd_card_unref(card);
                return -ENOMEM;
        }
        fmixer->card = card;
        fmixer->mixer = card->mixer_oss;
        file->private_data = fmixer;
        if (!try_module_get(card->module)) {
                kfree(fmixer);
                snd_card_file_remove(card, file);
                snd_card_unref(card);
                return -EFAULT;
        }
        snd_card_unref(card);
        return 0;
}

static int snd_mixer_oss_release(struct inode *inode, struct file *file)
{
        struct snd_mixer_oss_file *fmixer;

        if (file->private_data) {
                fmixer = file->private_data;
                module_put(fmixer->card->module);
                snd_card_file_remove(fmixer->card, file);
                kfree(fmixer);
        }
        return 0;
}

static int snd_mixer_oss_info(struct snd_mixer_oss_file *fmixer,
                              mixer_info __user *_info)
{
        struct snd_card *card = fmixer->card;
        struct snd_mixer_oss *mixer = fmixer->mixer;
        struct mixer_info info;
        
        memset(&info, 0, sizeof(info));
        strscpy(info.id, mixer && mixer->id[0] ? mixer->id : card->driver, sizeof(info.id));
        strscpy(info.name, mixer && mixer->name[0] ? mixer->name : card->mixername, sizeof(info.name));
        info.modify_counter = card->mixer_oss_change_count;
        if (copy_to_user(_info, &info, sizeof(info)))
                return -EFAULT;
        return 0;
}

static int snd_mixer_oss_info_obsolete(struct snd_mixer_oss_file *fmixer,
                                       _old_mixer_info __user *_info)
{
        struct snd_card *card = fmixer->card;
        struct snd_mixer_oss *mixer = fmixer->mixer;
        _old_mixer_info info;
        
        memset(&info, 0, sizeof(info));
        strscpy(info.id, mixer && mixer->id[0] ? mixer->id : card->driver, sizeof(info.id));
        strscpy(info.name, mixer && mixer->name[0] ? mixer->name : card->mixername, sizeof(info.name));
        if (copy_to_user(_info, &info, sizeof(info)))
                return -EFAULT;
        return 0;
}

static int snd_mixer_oss_caps(struct snd_mixer_oss_file *fmixer)
{
        struct snd_mixer_oss *mixer = fmixer->mixer;
        int result = 0;

        if (mixer == NULL)
                return -EIO;
        if (mixer->get_recsrc && mixer->put_recsrc)
                result |= SOUND_CAP_EXCL_INPUT;
        return result;
}

static int snd_mixer_oss_devmask(struct snd_mixer_oss_file *fmixer)
{
        struct snd_mixer_oss *mixer = fmixer->mixer;
        struct snd_mixer_oss_slot *pslot;
        int result = 0, chn;

        if (mixer == NULL)
                return -EIO;
        guard(mutex)(&mixer->reg_mutex);
        for (chn = 0; chn < 31; chn++) {
                pslot = &mixer->slots[chn];
                if (pslot->put_volume || pslot->put_recsrc)
                        result |= 1 << chn;
        }
        return result;
}

static int snd_mixer_oss_stereodevs(struct snd_mixer_oss_file *fmixer)
{
        struct snd_mixer_oss *mixer = fmixer->mixer;
        struct snd_mixer_oss_slot *pslot;
        int result = 0, chn;

        if (mixer == NULL)
                return -EIO;
        guard(mutex)(&mixer->reg_mutex);
        for (chn = 0; chn < 31; chn++) {
                pslot = &mixer->slots[chn];
                if (pslot->put_volume && pslot->stereo)
                        result |= 1 << chn;
        }
        return result;
}

static int snd_mixer_oss_recmask(struct snd_mixer_oss_file *fmixer)
{
        struct snd_mixer_oss *mixer = fmixer->mixer;
        int result = 0;

        if (mixer == NULL)
                return -EIO;
        guard(mutex)(&mixer->reg_mutex);
        if (mixer->put_recsrc && mixer->get_recsrc) {   /* exclusive */
                result = mixer->mask_recsrc;
        } else {
                struct snd_mixer_oss_slot *pslot;
                int chn;
                for (chn = 0; chn < 31; chn++) {
                        pslot = &mixer->slots[chn];
                        if (pslot->put_recsrc)
                                result |= 1 << chn;
                }
        }
        return result;
}

static int snd_mixer_oss_get_recsrc(struct snd_mixer_oss_file *fmixer)
{
        struct snd_mixer_oss *mixer = fmixer->mixer;
        int result = 0;

        if (mixer == NULL)
                return -EIO;
        guard(mutex)(&mixer->reg_mutex);
        if (mixer->put_recsrc && mixer->get_recsrc) {   /* exclusive */
                unsigned int index;
                result = mixer->get_recsrc(fmixer, &index);
                if (result < 0)
                        return result;
                result = 1 << index;
        } else {
                struct snd_mixer_oss_slot *pslot;
                int chn;
                for (chn = 0; chn < 31; chn++) {
                        pslot = &mixer->slots[chn];
                        if (pslot->get_recsrc) {
                                int active = 0;
                                pslot->get_recsrc(fmixer, pslot, &active);
                                if (active)
                                        result |= 1 << chn;
                        }
                }
        }
        mixer->oss_recsrc = result;
        return result;
}

static int snd_mixer_oss_set_recsrc(struct snd_mixer_oss_file *fmixer, int recsrc)
{
        struct snd_mixer_oss *mixer = fmixer->mixer;
        struct snd_mixer_oss_slot *pslot;
        int chn, active;
        unsigned int index;
        int result = 0;

        if (mixer == NULL)
                return -EIO;
        guard(mutex)(&mixer->reg_mutex);
        if (mixer->get_recsrc && mixer->put_recsrc) {   /* exclusive input */
                if (recsrc & ~mixer->oss_recsrc)
                        recsrc &= ~mixer->oss_recsrc;
                mixer->put_recsrc(fmixer, ffz(~recsrc));
                mixer->get_recsrc(fmixer, &index);
                result = 1 << index;
        }
        for (chn = 0; chn < 31; chn++) {
                pslot = &mixer->slots[chn];
                if (pslot->put_recsrc) {
                        active = (recsrc & (1 << chn)) ? 1 : 0;
                        pslot->put_recsrc(fmixer, pslot, active);
                }
        }
        if (! result) {
                for (chn = 0; chn < 31; chn++) {
                        pslot = &mixer->slots[chn];
                        if (pslot->get_recsrc) {
                                active = 0;
                                pslot->get_recsrc(fmixer, pslot, &active);
                                if (active)
                                        result |= 1 << chn;
                        }
                }
        }
        return result;
}

static int snd_mixer_oss_get_volume(struct snd_mixer_oss_file *fmixer, int slot)
{
        struct snd_mixer_oss *mixer = fmixer->mixer;
        struct snd_mixer_oss_slot *pslot;
        int result = 0, left, right;

        if (mixer == NULL || slot > 30)
                return -EIO;
        guard(mutex)(&mixer->reg_mutex);
        pslot = &mixer->slots[slot];
        left = pslot->volume[0];
        right = pslot->volume[1];
        if (pslot->get_volume)
                result = pslot->get_volume(fmixer, pslot, &left, &right);
        if (!pslot->stereo)
                right = left;
        if (snd_BUG_ON(left < 0 || left > 100))
                return -EIO;
        if (snd_BUG_ON(right < 0 || right > 100))
                return -EIO;
        if (result >= 0) {
                pslot->volume[0] = left;
                pslot->volume[1] = right;
                result = (left & 0xff) | ((right & 0xff) << 8);
        }
        return result;
}

static int snd_mixer_oss_set_volume(struct snd_mixer_oss_file *fmixer,
                                    int slot, int volume)
{
        struct snd_mixer_oss *mixer = fmixer->mixer;
        struct snd_mixer_oss_slot *pslot;
        int result = 0, left = volume & 0xff, right = (volume >> 8) & 0xff;

        if (mixer == NULL || slot > 30)
                return -EIO;
        guard(mutex)(&mixer->reg_mutex);
        pslot = &mixer->slots[slot];
        if (left > 100)
                left = 100;
        if (right > 100)
                right = 100;
        if (!pslot->stereo)
                right = left;
        if (pslot->put_volume)
                result = pslot->put_volume(fmixer, pslot, left, right);
        if (result < 0)
                return result;
        pslot->volume[0] = left;
        pslot->volume[1] = right;
        result = (left & 0xff) | ((right & 0xff) << 8);
        return result;
}

static int snd_mixer_oss_ioctl1(struct snd_mixer_oss_file *fmixer, unsigned int cmd, unsigned long arg)
{
        void __user *argp = (void __user *)arg;
        int __user *p = argp;
        int tmp;

        if (snd_BUG_ON(!fmixer))
                return -ENXIO;
        if (((cmd >> 8) & 0xff) == 'M') {
                switch (cmd) {
                case SOUND_MIXER_INFO:
                        return snd_mixer_oss_info(fmixer, argp);
                case SOUND_OLD_MIXER_INFO:
                        return snd_mixer_oss_info_obsolete(fmixer, argp);
                case SOUND_MIXER_WRITE_RECSRC:
                        if (get_user(tmp, p))
                                return -EFAULT;
                        tmp = snd_mixer_oss_set_recsrc(fmixer, tmp);
                        if (tmp < 0)
                                return tmp;
                        return put_user(tmp, p);
                case OSS_GETVERSION:
                        return put_user(SNDRV_OSS_VERSION, p);
                case OSS_ALSAEMULVER:
                        return put_user(1, p);
                case SOUND_MIXER_READ_DEVMASK:
                        tmp = snd_mixer_oss_devmask(fmixer);
                        if (tmp < 0)
                                return tmp;
                        return put_user(tmp, p);
                case SOUND_MIXER_READ_STEREODEVS:
                        tmp = snd_mixer_oss_stereodevs(fmixer);
                        if (tmp < 0)
                                return tmp;
                        return put_user(tmp, p);
                case SOUND_MIXER_READ_RECMASK:
                        tmp = snd_mixer_oss_recmask(fmixer);
                        if (tmp < 0)
                                return tmp;
                        return put_user(tmp, p);
                case SOUND_MIXER_READ_CAPS:
                        tmp = snd_mixer_oss_caps(fmixer);
                        if (tmp < 0)
                                return tmp;
                        return put_user(tmp, p);
                case SOUND_MIXER_READ_RECSRC:
                        tmp = snd_mixer_oss_get_recsrc(fmixer);
                        if (tmp < 0)
                                return tmp;
                        return put_user(tmp, p);
                }
        }
        if (cmd & SIOC_IN) {
                if (get_user(tmp, p))
                        return -EFAULT;
                tmp = snd_mixer_oss_set_volume(fmixer, cmd & 0xff, tmp);
                if (tmp < 0)
                        return tmp;
                return put_user(tmp, p);
        } else if (cmd & SIOC_OUT) {
                tmp = snd_mixer_oss_get_volume(fmixer, cmd & 0xff);
                if (tmp < 0)
                        return tmp;
                return put_user(tmp, p);
        }
        return -ENXIO;
}

static long snd_mixer_oss_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
        return snd_mixer_oss_ioctl1(file->private_data, cmd, arg);
}

int snd_mixer_oss_ioctl_card(struct snd_card *card, unsigned int cmd, unsigned long arg)
{
        struct snd_mixer_oss_file fmixer;
        
        if (snd_BUG_ON(!card))
                return -ENXIO;
        if (card->mixer_oss == NULL)
                return -ENXIO;
        memset(&fmixer, 0, sizeof(fmixer));
        fmixer.card = card;
        fmixer.mixer = card->mixer_oss;
        return snd_mixer_oss_ioctl1(&fmixer, cmd, arg);
}
EXPORT_SYMBOL(snd_mixer_oss_ioctl_card);

#ifdef CONFIG_COMPAT
/* all compatible */
static long snd_mixer_oss_ioctl_compat(struct file *file, unsigned int cmd,
                                       unsigned long arg)
{
        return snd_mixer_oss_ioctl1(file->private_data, cmd,
                                    (unsigned long)compat_ptr(arg));
}
#else
#define snd_mixer_oss_ioctl_compat      NULL
#endif

/*
 *  REGISTRATION PART
 */

static const struct file_operations snd_mixer_oss_f_ops =
{
        .owner =        THIS_MODULE,
        .open =         snd_mixer_oss_open,
        .release =      snd_mixer_oss_release,
        .unlocked_ioctl =       snd_mixer_oss_ioctl,
        .compat_ioctl = snd_mixer_oss_ioctl_compat,
};

/*
 *  utilities
 */

static long snd_mixer_oss_conv(long val, long omin, long omax, long nmin, long nmax)
{
        long orange = omax - omin, nrange = nmax - nmin;
        
        if (orange == 0)
                return 0;
        return DIV_ROUND_CLOSEST(nrange * (val - omin), orange) + nmin;
}

/* convert from alsa native to oss values (0-100) */
static long snd_mixer_oss_conv1(long val, long min, long max, int *old)
{
        if (val == snd_mixer_oss_conv(*old, 0, 100, min, max))
                return *old;
        return snd_mixer_oss_conv(val, min, max, 0, 100);
}

/* convert from oss to alsa native values */
static long snd_mixer_oss_conv2(long val, long min, long max)
{
        return snd_mixer_oss_conv(val, 0, 100, min, max);
}

#if 0
static void snd_mixer_oss_recsrce_set(struct snd_card *card, int slot)
{
        struct snd_mixer_oss *mixer = card->mixer_oss;
        if (mixer)
                mixer->mask_recsrc |= 1 << slot;
}

static int snd_mixer_oss_recsrce_get(struct snd_card *card, int slot)
{
        struct snd_mixer_oss *mixer = card->mixer_oss;
        if (mixer && (mixer->mask_recsrc & (1 << slot)))
                return 1;
        return 0;
}
#endif

#define SNDRV_MIXER_OSS_SIGNATURE               0x65999250

#define SNDRV_MIXER_OSS_ITEM_GLOBAL     0
#define SNDRV_MIXER_OSS_ITEM_GSWITCH    1
#define SNDRV_MIXER_OSS_ITEM_GROUTE     2
#define SNDRV_MIXER_OSS_ITEM_GVOLUME    3
#define SNDRV_MIXER_OSS_ITEM_PSWITCH    4
#define SNDRV_MIXER_OSS_ITEM_PROUTE     5
#define SNDRV_MIXER_OSS_ITEM_PVOLUME    6
#define SNDRV_MIXER_OSS_ITEM_CSWITCH    7
#define SNDRV_MIXER_OSS_ITEM_CROUTE     8
#define SNDRV_MIXER_OSS_ITEM_CVOLUME    9
#define SNDRV_MIXER_OSS_ITEM_CAPTURE    10

#define SNDRV_MIXER_OSS_ITEM_COUNT      11

#define SNDRV_MIXER_OSS_PRESENT_GLOBAL  (1<<0)
#define SNDRV_MIXER_OSS_PRESENT_GSWITCH (1<<1)
#define SNDRV_MIXER_OSS_PRESENT_GROUTE  (1<<2)
#define SNDRV_MIXER_OSS_PRESENT_GVOLUME (1<<3)
#define SNDRV_MIXER_OSS_PRESENT_PSWITCH (1<<4)
#define SNDRV_MIXER_OSS_PRESENT_PROUTE  (1<<5)
#define SNDRV_MIXER_OSS_PRESENT_PVOLUME (1<<6)
#define SNDRV_MIXER_OSS_PRESENT_CSWITCH (1<<7)
#define SNDRV_MIXER_OSS_PRESENT_CROUTE  (1<<8)
#define SNDRV_MIXER_OSS_PRESENT_CVOLUME (1<<9)
#define SNDRV_MIXER_OSS_PRESENT_CAPTURE (1<<10)

struct slot {
        unsigned int signature;
        unsigned int present;
        unsigned int channels;
        unsigned int numid[SNDRV_MIXER_OSS_ITEM_COUNT];
        unsigned int capture_item;
        const struct snd_mixer_oss_assign_table *assigned;
        unsigned int allocated: 1;
};

#define ID_UNKNOWN      ((unsigned int)-1)

static struct snd_kcontrol *snd_mixer_oss_test_id(struct snd_mixer_oss *mixer, const char *name, int index)
{
        struct snd_card *card = mixer->card;
        struct snd_ctl_elem_id id;
        
        memset(&id, 0, sizeof(id));
        id.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
        strscpy(id.name, name, sizeof(id.name));
        id.index = index;
        return snd_ctl_find_id(card, &id);
}

static void snd_mixer_oss_get_volume1_vol(struct snd_mixer_oss_file *fmixer,
                                          struct snd_mixer_oss_slot *pslot,
                                          unsigned int numid,
                                          int *left, int *right)
{
        struct snd_kcontrol *kctl;
        struct snd_card *card = fmixer->card;

        if (numid == ID_UNKNOWN)
                return;
        guard(rwsem_read)(&card->controls_rwsem);
        if (card->shutdown)
                return;
        kctl = snd_ctl_find_numid(card, numid);
        if (!kctl)
                return;

        struct snd_ctl_elem_info *uinfo __free(kfree) =
                kzalloc_obj(*uinfo);
        struct snd_ctl_elem_value *uctl __free(kfree) =
                kzalloc_obj(*uctl);
        if (uinfo == NULL || uctl == NULL)
                return;
        if (kctl->info(kctl, uinfo))
                return;
        if (kctl->get(kctl, uctl))
                return;
        if (uinfo->type == SNDRV_CTL_ELEM_TYPE_BOOLEAN &&
            uinfo->value.integer.min == 0 && uinfo->value.integer.max == 1)
                return;
        *left = snd_mixer_oss_conv1(uctl->value.integer.value[0], uinfo->value.integer.min, uinfo->value.integer.max, &pslot->volume[0]);
        if (uinfo->count > 1)
                *right = snd_mixer_oss_conv1(uctl->value.integer.value[1], uinfo->value.integer.min, uinfo->value.integer.max, &pslot->volume[1]);
}

static void snd_mixer_oss_get_volume1_sw(struct snd_mixer_oss_file *fmixer,
                                         struct snd_mixer_oss_slot *pslot,
                                         unsigned int numid,
                                         int *left, int *right,
                                         int route)
{
        struct snd_kcontrol *kctl;
        struct snd_card *card = fmixer->card;

        if (numid == ID_UNKNOWN)
                return;
        guard(rwsem_read)(&card->controls_rwsem);
        if (card->shutdown)
                return;
        kctl = snd_ctl_find_numid(card, numid);
        if (!kctl)
                return;

        struct snd_ctl_elem_info *uinfo __free(kfree) =
                kzalloc_obj(*uinfo);
        struct snd_ctl_elem_value *uctl __free(kfree) =
                kzalloc_obj(*uctl);
        if (uinfo == NULL || uctl == NULL)
                return;
        if (kctl->info(kctl, uinfo))
                return;
        if (kctl->get(kctl, uctl))
                return;
        if (!uctl->value.integer.value[0]) {
                *left = 0;
                if (uinfo->count == 1)
                        *right = 0;
        }
        if (uinfo->count > 1 && !uctl->value.integer.value[route ? 3 : 1])
                *right = 0;
}

static int snd_mixer_oss_get_volume1(struct snd_mixer_oss_file *fmixer,
                                     struct snd_mixer_oss_slot *pslot,
                                     int *left, int *right)
{
        struct slot *slot = pslot->private_data;
        
        *left = *right = 100;
        if (slot->present & SNDRV_MIXER_OSS_PRESENT_PVOLUME) {
                snd_mixer_oss_get_volume1_vol(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PVOLUME], left, right);
        } else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GVOLUME) {
                snd_mixer_oss_get_volume1_vol(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GVOLUME], left, right);
        } else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GLOBAL) {
                snd_mixer_oss_get_volume1_vol(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GLOBAL], left, right);
        }
        if (slot->present & SNDRV_MIXER_OSS_PRESENT_PSWITCH) {
                snd_mixer_oss_get_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PSWITCH], left, right, 0);
        } else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GSWITCH) {
                snd_mixer_oss_get_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GSWITCH], left, right, 0);
        } else if (slot->present & SNDRV_MIXER_OSS_PRESENT_PROUTE) {
                snd_mixer_oss_get_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PROUTE], left, right, 1);
        } else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GROUTE) {
                snd_mixer_oss_get_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GROUTE], left, right, 1);
        }
        return 0;
}

static void snd_mixer_oss_put_volume1_vol(struct snd_mixer_oss_file *fmixer,
                                          struct snd_mixer_oss_slot *pslot,
                                          unsigned int numid,
                                          int left, int right)
{
        struct snd_kcontrol *kctl;
        struct snd_card *card = fmixer->card;
        int res;

        if (numid == ID_UNKNOWN)
                return;
        guard(rwsem_read)(&card->controls_rwsem);
        if (card->shutdown)
                return;
        kctl = snd_ctl_find_numid(card, numid);
        if (!kctl)
                return;

        struct snd_ctl_elem_info *uinfo __free(kfree) =
                kzalloc_obj(*uinfo);
        struct snd_ctl_elem_value *uctl __free(kfree) =
                kzalloc_obj(*uctl);
        if (uinfo == NULL || uctl == NULL)
                return;
        if (kctl->info(kctl, uinfo))
                return;
        if (uinfo->type == SNDRV_CTL_ELEM_TYPE_BOOLEAN &&
            uinfo->value.integer.min == 0 && uinfo->value.integer.max == 1)
                return;
        uctl->value.integer.value[0] = snd_mixer_oss_conv2(left, uinfo->value.integer.min, uinfo->value.integer.max);
        if (uinfo->count > 1)
                uctl->value.integer.value[1] = snd_mixer_oss_conv2(right, uinfo->value.integer.min, uinfo->value.integer.max);
        res = kctl->put(kctl, uctl);
        if (res < 0)
                return;
        if (res > 0)
                snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id);
}

static void snd_mixer_oss_put_volume1_sw(struct snd_mixer_oss_file *fmixer,
                                         struct snd_mixer_oss_slot *pslot,
                                         unsigned int numid,
                                         int left, int right,
                                         int route)
{
        struct snd_kcontrol *kctl;
        struct snd_card *card = fmixer->card;
        int res;

        if (numid == ID_UNKNOWN)
                return;
        guard(rwsem_read)(&card->controls_rwsem);
        if (card->shutdown)
                return;
        kctl = snd_ctl_find_numid(card, numid);
        if (!kctl)
                return;

        struct snd_ctl_elem_info *uinfo __free(kfree) =
                kzalloc_obj(*uinfo);
        struct snd_ctl_elem_value *uctl __free(kfree) =
                kzalloc_obj(*uctl);
        if (uinfo == NULL || uctl == NULL)
                return;
        if (kctl->info(kctl, uinfo))
                return;
        if (uinfo->count > 1) {
                uctl->value.integer.value[0] = left > 0 ? 1 : 0;
                uctl->value.integer.value[route ? 3 : 1] = right > 0 ? 1 : 0;
                if (route) {
                        uctl->value.integer.value[1] =
                        uctl->value.integer.value[2] = 0;
                }
        } else {
                uctl->value.integer.value[0] = (left > 0 || right > 0) ? 1 : 0;
        }
        res = kctl->put(kctl, uctl);
        if (res < 0)
                return;
        if (res > 0)
                snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id);
}

static int snd_mixer_oss_put_volume1(struct snd_mixer_oss_file *fmixer,
                                     struct snd_mixer_oss_slot *pslot,
                                     int left, int right)
{
        struct slot *slot = pslot->private_data;
        
        if (slot->present & SNDRV_MIXER_OSS_PRESENT_PVOLUME) {
                snd_mixer_oss_put_volume1_vol(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PVOLUME], left, right);
                if (slot->present & SNDRV_MIXER_OSS_PRESENT_CVOLUME)
                        snd_mixer_oss_put_volume1_vol(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CVOLUME], left, right);
        } else if (slot->present & SNDRV_MIXER_OSS_PRESENT_CVOLUME) {
                snd_mixer_oss_put_volume1_vol(fmixer, pslot,
                        slot->numid[SNDRV_MIXER_OSS_ITEM_CVOLUME], left, right);
        } else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GVOLUME) {
                snd_mixer_oss_put_volume1_vol(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GVOLUME], left, right);
        } else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GLOBAL) {
                snd_mixer_oss_put_volume1_vol(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GLOBAL], left, right);
        }
        if (left || right) {
                if (slot->present & SNDRV_MIXER_OSS_PRESENT_PSWITCH)
                        snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PSWITCH], left, right, 0);
                if (slot->present & SNDRV_MIXER_OSS_PRESENT_CSWITCH)
                        snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CSWITCH], left, right, 0);
                if (slot->present & SNDRV_MIXER_OSS_PRESENT_GSWITCH)
                        snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GSWITCH], left, right, 0);
                if (slot->present & SNDRV_MIXER_OSS_PRESENT_PROUTE)
                        snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PROUTE], left, right, 1);
                if (slot->present & SNDRV_MIXER_OSS_PRESENT_CROUTE)
                        snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CROUTE], left, right, 1);
                if (slot->present & SNDRV_MIXER_OSS_PRESENT_GROUTE)
                        snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GROUTE], left, right, 1);
        } else {
                if (slot->present & SNDRV_MIXER_OSS_PRESENT_PSWITCH) {
                        snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PSWITCH], left, right, 0);
                } else if (slot->present & SNDRV_MIXER_OSS_PRESENT_CSWITCH) {
                        snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CSWITCH], left, right, 0);
                } else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GSWITCH) {
                        snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GSWITCH], left, right, 0);
                } else if (slot->present & SNDRV_MIXER_OSS_PRESENT_PROUTE) {
                        snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PROUTE], left, right, 1);
                } else if (slot->present & SNDRV_MIXER_OSS_PRESENT_CROUTE) {
                        snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CROUTE], left, right, 1);
                } else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GROUTE) {
                        snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GROUTE], left, right, 1);
                }
        }
        return 0;
}

static int snd_mixer_oss_get_recsrc1_sw(struct snd_mixer_oss_file *fmixer,
                                        struct snd_mixer_oss_slot *pslot,
                                        int *active)
{
        struct slot *slot = pslot->private_data;
        int left, right;
        
        left = right = 1;
        snd_mixer_oss_get_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CSWITCH], &left, &right, 0);
        *active = (left || right) ? 1 : 0;
        return 0;
}

static int snd_mixer_oss_get_recsrc1_route(struct snd_mixer_oss_file *fmixer,
                                           struct snd_mixer_oss_slot *pslot,
                                           int *active)
{
        struct slot *slot = pslot->private_data;
        int left, right;
        
        left = right = 1;
        snd_mixer_oss_get_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CROUTE], &left, &right, 1);
        *active = (left || right) ? 1 : 0;
        return 0;
}

static int snd_mixer_oss_put_recsrc1_sw(struct snd_mixer_oss_file *fmixer,
                                        struct snd_mixer_oss_slot *pslot,
                                        int active)
{
        struct slot *slot = pslot->private_data;
        
        snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CSWITCH], active, active, 0);
        return 0;
}

static int snd_mixer_oss_put_recsrc1_route(struct snd_mixer_oss_file *fmixer,
                                           struct snd_mixer_oss_slot *pslot,
                                           int active)
{
        struct slot *slot = pslot->private_data;
        
        snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CROUTE], active, active, 1);
        return 0;
}

static int snd_mixer_oss_get_recsrc2(struct snd_mixer_oss_file *fmixer, unsigned int *active_index)
{
        struct snd_card *card = fmixer->card;
        struct snd_mixer_oss *mixer = fmixer->mixer;
        struct snd_kcontrol *kctl;
        struct snd_mixer_oss_slot *pslot;
        struct slot *slot;
        int err, idx;
        
        struct snd_ctl_elem_info *uinfo __free(kfree) =
                kzalloc_obj(*uinfo);
        struct snd_ctl_elem_value *uctl __free(kfree) =
                kzalloc_obj(*uctl);
        if (uinfo == NULL || uctl == NULL)
                return -ENOMEM;
        guard(rwsem_read)(&card->controls_rwsem);
        if (card->shutdown)
                return -ENODEV;
        kctl = snd_mixer_oss_test_id(mixer, "Capture Source", 0);
        if (!kctl)
                return -ENOENT;
        err = kctl->info(kctl, uinfo);
        if (err < 0)
                return err;
        err = kctl->get(kctl, uctl);
        if (err < 0)
                return err;
        for (idx = 0; idx < 32; idx++) {
                if (!(mixer->mask_recsrc & (1 << idx)))
                        continue;
                pslot = &mixer->slots[idx];
                slot = pslot->private_data;
                if (slot->signature != SNDRV_MIXER_OSS_SIGNATURE)
                        continue;
                if (!(slot->present & SNDRV_MIXER_OSS_PRESENT_CAPTURE))
                        continue;
                if (slot->capture_item == uctl->value.enumerated.item[0]) {
                        *active_index = idx;
                        break;
                }
        }
        return 0;
}

static int snd_mixer_oss_put_recsrc2(struct snd_mixer_oss_file *fmixer, unsigned int active_index)
{
        struct snd_card *card = fmixer->card;
        struct snd_mixer_oss *mixer = fmixer->mixer;
        struct snd_kcontrol *kctl;
        struct snd_mixer_oss_slot *pslot;
        struct slot *slot = NULL;
        int err;
        unsigned int idx;

        struct snd_ctl_elem_info *uinfo __free(kfree) =
                kzalloc_obj(*uinfo);
        struct snd_ctl_elem_value *uctl __free(kfree) =
                kzalloc_obj(*uctl);
        if (uinfo == NULL || uctl == NULL)
                return -ENOMEM;
        guard(rwsem_read)(&card->controls_rwsem);
        if (card->shutdown)
                return -ENODEV;
        kctl = snd_mixer_oss_test_id(mixer, "Capture Source", 0);
        if (!kctl)
                return -ENOENT;
        err = kctl->info(kctl, uinfo);
        if (err < 0)
                return err;
        for (idx = 0; idx < 32; idx++) {
                if (!(mixer->mask_recsrc & (1 << idx)))
                        continue;
                pslot = &mixer->slots[idx];
                slot = pslot->private_data;
                if (slot->signature != SNDRV_MIXER_OSS_SIGNATURE)
                        continue;
                if (!(slot->present & SNDRV_MIXER_OSS_PRESENT_CAPTURE))
                        continue;
                if (idx == active_index)
                        break;
                slot = NULL;
        }
        if (!slot)
                return 0;
        for (idx = 0; idx < uinfo->count; idx++)
                uctl->value.enumerated.item[idx] = slot->capture_item;
        err = kctl->put(kctl, uctl);
        if (err > 0)
                snd_ctl_notify(fmixer->card, SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id);
        return 0;
}

struct snd_mixer_oss_assign_table {
        int oss_id;
        const char *name;
        int index;
};

static int snd_mixer_oss_build_test(struct snd_mixer_oss *mixer, struct slot *slot, const char *name, int index, int item)
{
        struct snd_kcontrol *kcontrol;
        struct snd_card *card = mixer->card;
        int err;

        struct snd_ctl_elem_info *info __free(kfree) =
                kmalloc(sizeof(*info), GFP_KERNEL);
        if (!info)
                return -ENOMEM;
        scoped_guard(rwsem_read, &card->controls_rwsem) {
                if (card->shutdown)
                        return -ENODEV;
                kcontrol = snd_mixer_oss_test_id(mixer, name, index);
                if (kcontrol == NULL)
                        return 0;
                err = kcontrol->info(kcontrol, info);
                if (err < 0)
                        return err;
                slot->numid[item] = kcontrol->id.numid;
        }
        if (info->count > slot->channels)
                slot->channels = info->count;
        slot->present |= 1 << item;
        return 0;
}

static void snd_mixer_oss_slot_free(struct snd_mixer_oss_slot *chn)
{
        struct slot *p = chn->private_data;
        if (p) {
                if (p->allocated && p->assigned) {
                        kfree(p->assigned->name);
                        kfree(p->assigned);
                }
                kfree(p);
        }
}

static void mixer_slot_clear(struct snd_mixer_oss_slot *rslot)
{
        int idx = rslot->number; /* remember this */
        if (rslot->private_free)
                rslot->private_free(rslot);
        memset(rslot, 0, sizeof(*rslot));
        rslot->number = idx;
}

/* In a separate function to keep gcc 3.2 happy - do NOT merge this in
   snd_mixer_oss_build_input! */
static int snd_mixer_oss_build_test_all(struct snd_mixer_oss *mixer,
                                        const struct snd_mixer_oss_assign_table *ptr,
                                        struct slot *slot)
{
        char str[64];
        int err;

        err = snd_mixer_oss_build_test(mixer, slot, ptr->name, ptr->index,
                                       SNDRV_MIXER_OSS_ITEM_GLOBAL);
        if (err)
                return err;
        sprintf(str, "%s Switch", ptr->name);
        err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
                                       SNDRV_MIXER_OSS_ITEM_GSWITCH);
        if (err)
                return err;
        sprintf(str, "%s Route", ptr->name);
        err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
                                       SNDRV_MIXER_OSS_ITEM_GROUTE);
        if (err)
                return err;
        sprintf(str, "%s Volume", ptr->name);
        err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
                                       SNDRV_MIXER_OSS_ITEM_GVOLUME);
        if (err)
                return err;
        sprintf(str, "%s Playback Switch", ptr->name);
        err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
                                       SNDRV_MIXER_OSS_ITEM_PSWITCH);
        if (err)
                return err;
        sprintf(str, "%s Playback Route", ptr->name);
        err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
                                       SNDRV_MIXER_OSS_ITEM_PROUTE);
        if (err)
                return err;
        sprintf(str, "%s Playback Volume", ptr->name);
        err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
                                       SNDRV_MIXER_OSS_ITEM_PVOLUME);
        if (err)
                return err;
        sprintf(str, "%s Capture Switch", ptr->name);
        err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
                                       SNDRV_MIXER_OSS_ITEM_CSWITCH);
        if (err)
                return err;
        sprintf(str, "%s Capture Route", ptr->name);
        err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
                                       SNDRV_MIXER_OSS_ITEM_CROUTE);
        if (err)
                return err;
        sprintf(str, "%s Capture Volume", ptr->name);
        err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
                                       SNDRV_MIXER_OSS_ITEM_CVOLUME);
        if (err)
                return err;

        return 0;
}

/*
 * build an OSS mixer element.
 * ptr_allocated means the entry is dynamically allocated (change via proc file).
 * when replace_old = 1, the old entry is replaced with the new one.
 */
static int snd_mixer_oss_build_input(struct snd_mixer_oss *mixer,
                                     const struct snd_mixer_oss_assign_table *ptr,
                                     int ptr_allocated, int replace_old)
{
        struct slot slot;
        struct slot *pslot;
        struct snd_kcontrol *kctl;
        struct snd_mixer_oss_slot *rslot;
        const char *str;
        
        /* check if already assigned */
        if (mixer->slots[ptr->oss_id].get_volume && ! replace_old)
                return 0;

        memset(&slot, 0, sizeof(slot));
        memset(slot.numid, 0xff, sizeof(slot.numid)); /* ID_UNKNOWN */
        if (snd_mixer_oss_build_test_all(mixer, ptr, &slot))
                return 0;
        guard(rwsem_read)(&mixer->card->controls_rwsem);
        if (mixer->card->shutdown)
                return -ENODEV;
        kctl = NULL;
        if (!ptr->index)
                kctl = snd_mixer_oss_test_id(mixer, "Capture Source", 0);
        if (kctl) {
                struct snd_ctl_elem_info *uinfo __free(kfree) =
                        kzalloc_obj(*uinfo);

                if (!uinfo)
                        return -ENOMEM;
                        
                if (kctl->info(kctl, uinfo))
                        return 0;
                str = ptr->name;
                if (!strcmp(str, "Master"))
                        str = "Mix";
                else if (!strcmp(str, "Master Mono"))
                        str = "Mix Mono";
                slot.capture_item = 0;
                if (!strcmp(uinfo->value.enumerated.name, str)) {
                        slot.present |= SNDRV_MIXER_OSS_PRESENT_CAPTURE;
                } else {
                        for (slot.capture_item = 1; slot.capture_item < uinfo->value.enumerated.items; slot.capture_item++) {
                                uinfo->value.enumerated.item = slot.capture_item;
                                if (kctl->info(kctl, uinfo))
                                        return 0;
                                if (!strcmp(uinfo->value.enumerated.name, str)) {
                                        slot.present |= SNDRV_MIXER_OSS_PRESENT_CAPTURE;
                                        break;
                                }
                        }
                }
        }
        if (slot.present != 0) {
                pslot = kmalloc_obj(slot);
                if (! pslot)
                        return -ENOMEM;
                *pslot = slot;
                pslot->signature = SNDRV_MIXER_OSS_SIGNATURE;
                pslot->assigned = ptr;
                pslot->allocated = ptr_allocated;
                rslot = &mixer->slots[ptr->oss_id];
                mixer_slot_clear(rslot);
                rslot->stereo = slot.channels > 1 ? 1 : 0;
                rslot->get_volume = snd_mixer_oss_get_volume1;
                rslot->put_volume = snd_mixer_oss_put_volume1;
                /* note: ES18xx have both Capture Source and XX Capture Volume !!! */
                if (slot.present & SNDRV_MIXER_OSS_PRESENT_CSWITCH) {
                        rslot->get_recsrc = snd_mixer_oss_get_recsrc1_sw;
                        rslot->put_recsrc = snd_mixer_oss_put_recsrc1_sw;
                } else if (slot.present & SNDRV_MIXER_OSS_PRESENT_CROUTE) {
                        rslot->get_recsrc = snd_mixer_oss_get_recsrc1_route;
                        rslot->put_recsrc = snd_mixer_oss_put_recsrc1_route;
                } else if (slot.present & SNDRV_MIXER_OSS_PRESENT_CAPTURE) {
                        mixer->mask_recsrc |= 1 << ptr->oss_id;
                }
                rslot->private_data = pslot;
                rslot->private_free = snd_mixer_oss_slot_free;
                return 1;
        }
        return 0;
}

#ifdef CONFIG_SND_PROC_FS
/*
 */
#define MIXER_VOL(name) [SOUND_MIXER_##name] = #name
static const char * const oss_mixer_names[SNDRV_OSS_MAX_MIXERS] = {
        MIXER_VOL(VOLUME),
        MIXER_VOL(BASS),
        MIXER_VOL(TREBLE),
        MIXER_VOL(SYNTH),
        MIXER_VOL(PCM),
        MIXER_VOL(SPEAKER),
        MIXER_VOL(LINE),
        MIXER_VOL(MIC),
        MIXER_VOL(CD),
        MIXER_VOL(IMIX),
        MIXER_VOL(ALTPCM),
        MIXER_VOL(RECLEV),
        MIXER_VOL(IGAIN),
        MIXER_VOL(OGAIN),
        MIXER_VOL(LINE1),
        MIXER_VOL(LINE2),
        MIXER_VOL(LINE3),
        MIXER_VOL(DIGITAL1),
        MIXER_VOL(DIGITAL2),
        MIXER_VOL(DIGITAL3),
        MIXER_VOL(PHONEIN),
        MIXER_VOL(PHONEOUT),
        MIXER_VOL(VIDEO),
        MIXER_VOL(RADIO),
        MIXER_VOL(MONITOR),
};
        
/*
 *  /proc interface
 */

static void snd_mixer_oss_proc_read(struct snd_info_entry *entry,
                                    struct snd_info_buffer *buffer)
{
        struct snd_mixer_oss *mixer = entry->private_data;
        int i;

        guard(mutex)(&mixer->reg_mutex);
        for (i = 0; i < SNDRV_OSS_MAX_MIXERS; i++) {
                struct slot *p;

                if (! oss_mixer_names[i])
                        continue;
                p = (struct slot *)mixer->slots[i].private_data;
                snd_iprintf(buffer, "%s ", oss_mixer_names[i]);
                if (p && p->assigned)
                        snd_iprintf(buffer, "\"%s\" %d\n",
                                    p->assigned->name,
                                    p->assigned->index);
                else
                        snd_iprintf(buffer, "\"\" 0\n");
        }
}

static void snd_mixer_oss_proc_write(struct snd_info_entry *entry,
                                     struct snd_info_buffer *buffer)
{
        struct snd_mixer_oss *mixer = entry->private_data;
        char line[128], str[32], idxstr[16];
        const char *cptr;
        unsigned int idx;
        int ch;
        struct snd_mixer_oss_assign_table *tbl;
        struct slot *slot;

        while (!snd_info_get_line(buffer, line, sizeof(line))) {
                cptr = snd_info_get_str(str, line, sizeof(str));
                for (ch = 0; ch < SNDRV_OSS_MAX_MIXERS; ch++)
                        if (oss_mixer_names[ch] && strcmp(oss_mixer_names[ch], str) == 0)
                                break;
                if (ch >= SNDRV_OSS_MAX_MIXERS) {
                        pr_err("ALSA: mixer_oss: invalid OSS volume '%s'\n",
                               str);
                        continue;
                }
                cptr = snd_info_get_str(str, cptr, sizeof(str));
                if (! *str) {
                        /* remove the entry */
                        scoped_guard(mutex, &mixer->reg_mutex)
                                mixer_slot_clear(&mixer->slots[ch]);
                        continue;
                }
                snd_info_get_str(idxstr, cptr, sizeof(idxstr));
                idx = simple_strtoul(idxstr, NULL, 10);
                if (idx >= 0x4000) { /* too big */
                        pr_err("ALSA: mixer_oss: invalid index %d\n", idx);
                        continue;
                }
                scoped_guard(mutex, &mixer->reg_mutex) {
                        slot = (struct slot *)mixer->slots[ch].private_data;
                        if (slot && slot->assigned &&
                            slot->assigned->index == idx && !strcmp(slot->assigned->name, str))
                                /* not changed */
                                break;
                        tbl = kmalloc(sizeof(*tbl), GFP_KERNEL);
                        if (!tbl)
                                break;
                        tbl->oss_id = ch;
                        tbl->name = kstrdup(str, GFP_KERNEL);
                        if (!tbl->name) {
                                kfree(tbl);
                                break;
                        }
                        tbl->index = idx;
                        if (snd_mixer_oss_build_input(mixer, tbl, 1, 1) <= 0) {
                                kfree(tbl->name);
                                kfree(tbl);
                        }
                }
        }
}

static void snd_mixer_oss_proc_init(struct snd_mixer_oss *mixer)
{
        struct snd_info_entry *entry;

        entry = snd_info_create_card_entry(mixer->card, "oss_mixer",
                                           mixer->card->proc_root);
        if (! entry)
                return;
        entry->content = SNDRV_INFO_CONTENT_TEXT;
        entry->mode = S_IFREG | 0644;
        entry->c.text.read = snd_mixer_oss_proc_read;
        entry->c.text.write = snd_mixer_oss_proc_write;
        entry->private_data = mixer;
        if (snd_info_register(entry) < 0) {
                snd_info_free_entry(entry);
                entry = NULL;
        }
        mixer->proc_entry = entry;
}

static void snd_mixer_oss_proc_done(struct snd_mixer_oss *mixer)
{
        snd_info_free_entry(mixer->proc_entry);
        mixer->proc_entry = NULL;
}
#else /* !CONFIG_SND_PROC_FS */
#define snd_mixer_oss_proc_init(mix)
#define snd_mixer_oss_proc_done(mix)
#endif /* CONFIG_SND_PROC_FS */

static void snd_mixer_oss_build(struct snd_mixer_oss *mixer)
{
        static const struct snd_mixer_oss_assign_table table[] = {
                { SOUND_MIXER_VOLUME,   "Master",               0 },
                { SOUND_MIXER_VOLUME,   "Front",                0 }, /* fallback */
                { SOUND_MIXER_BASS,     "Tone Control - Bass",  0 },
                { SOUND_MIXER_TREBLE,   "Tone Control - Treble", 0 },
                { SOUND_MIXER_SYNTH,    "Synth",                0 },
                { SOUND_MIXER_SYNTH,    "FM",                   0 }, /* fallback */
                { SOUND_MIXER_SYNTH,    "Music",                0 }, /* fallback */
                { SOUND_MIXER_PCM,      "PCM",                  0 },
                { SOUND_MIXER_SPEAKER,  "Beep",                 0 },
                { SOUND_MIXER_SPEAKER,  "PC Speaker",           0 }, /* fallback */
                { SOUND_MIXER_SPEAKER,  "Speaker",              0 }, /* fallback */
                { SOUND_MIXER_LINE,     "Line",                 0 },
                { SOUND_MIXER_MIC,      "Mic",                  0 },
                { SOUND_MIXER_CD,       "CD",                   0 },
                { SOUND_MIXER_IMIX,     "Monitor Mix",          0 },
                { SOUND_MIXER_ALTPCM,   "PCM",                  1 },
                { SOUND_MIXER_ALTPCM,   "Headphone",            0 }, /* fallback */
                { SOUND_MIXER_ALTPCM,   "Wave",                 0 }, /* fallback */
                { SOUND_MIXER_RECLEV,   "-- nothing --",        0 },
                { SOUND_MIXER_IGAIN,    "Capture",              0 },
                { SOUND_MIXER_OGAIN,    "Playback",             0 },
                { SOUND_MIXER_LINE1,    "Aux",                  0 },
                { SOUND_MIXER_LINE2,    "Aux",                  1 },
                { SOUND_MIXER_LINE3,    "Aux",                  2 },
                { SOUND_MIXER_DIGITAL1, "Digital",              0 },
                { SOUND_MIXER_DIGITAL1, "IEC958",               0 }, /* fallback */
                { SOUND_MIXER_DIGITAL1, "IEC958 Optical",       0 }, /* fallback */
                { SOUND_MIXER_DIGITAL1, "IEC958 Coaxial",       0 }, /* fallback */
                { SOUND_MIXER_DIGITAL2, "Digital",              1 },
                { SOUND_MIXER_DIGITAL3, "Digital",              2 },
                { SOUND_MIXER_PHONEIN,  "Phone",                0 },
                { SOUND_MIXER_PHONEOUT, "Master Mono",          0 },
                { SOUND_MIXER_PHONEOUT, "Speaker",              0 }, /*fallback*/
                { SOUND_MIXER_PHONEOUT, "Mono",                 0 }, /*fallback*/
                { SOUND_MIXER_PHONEOUT, "Phone",                0 }, /* fallback */
                { SOUND_MIXER_VIDEO,    "Video",                0 },
                { SOUND_MIXER_RADIO,    "Radio",                0 },
                { SOUND_MIXER_MONITOR,  "Monitor",              0 }
        };
        unsigned int idx;
        
        for (idx = 0; idx < ARRAY_SIZE(table); idx++)
                snd_mixer_oss_build_input(mixer, &table[idx], 0, 0);
        if (mixer->mask_recsrc) {
                mixer->get_recsrc = snd_mixer_oss_get_recsrc2;
                mixer->put_recsrc = snd_mixer_oss_put_recsrc2;
        }
}

/*
 *
 */

static int snd_mixer_oss_free1(void *private)
{
        struct snd_mixer_oss *mixer = private;
        struct snd_card *card;
        int idx;
 
        if (!mixer)
                return 0;
        card = mixer->card;
        if (snd_BUG_ON(mixer != card->mixer_oss))
                return -ENXIO;
        card->mixer_oss = NULL;
        for (idx = 0; idx < SNDRV_OSS_MAX_MIXERS; idx++) {
                struct snd_mixer_oss_slot *chn = &mixer->slots[idx];
                if (chn->private_free)
                        chn->private_free(chn);
        }
        kfree(mixer);
        return 0;
}

static int snd_mixer_oss_notify_handler(struct snd_card *card, int cmd)
{
        struct snd_mixer_oss *mixer;

        if (cmd == SND_MIXER_OSS_NOTIFY_REGISTER) {
                int idx, err;

                mixer = kzalloc_objs(*mixer, 2);
                if (mixer == NULL)
                        return -ENOMEM;
                mutex_init(&mixer->reg_mutex);
                err = snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_MIXER,
                                              card, 0,
                                              &snd_mixer_oss_f_ops, card);
                if (err < 0) {
                        dev_err(card->dev,
                                "unable to register OSS mixer device %i:%i\n",
                                card->number, 0);
                        kfree(mixer);
                        return err;
                }
                mixer->oss_dev_alloc = 1;
                mixer->card = card;
                if (*card->mixername)
                        strscpy(mixer->name, card->mixername, sizeof(mixer->name));
                else
                        snprintf(mixer->name, sizeof(mixer->name),
                                 "mixer%i", card->number);
#ifdef SNDRV_OSS_INFO_DEV_MIXERS
                snd_oss_info_register(SNDRV_OSS_INFO_DEV_MIXERS,
                                      card->number,
                                      mixer->name);
#endif
                for (idx = 0; idx < SNDRV_OSS_MAX_MIXERS; idx++)
                        mixer->slots[idx].number = idx;
                card->mixer_oss = mixer;
                snd_mixer_oss_build(mixer);
                snd_mixer_oss_proc_init(mixer);
        } else {
                mixer = card->mixer_oss;
                if (mixer == NULL)
                        return 0;
                if (mixer->oss_dev_alloc) {
#ifdef SNDRV_OSS_INFO_DEV_MIXERS
                        snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_MIXERS, mixer->card->number);
#endif
                        snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_MIXER, mixer->card, 0);
                        mixer->oss_dev_alloc = 0;
                }
                if (cmd == SND_MIXER_OSS_NOTIFY_DISCONNECT)
                        return 0;
                snd_mixer_oss_proc_done(mixer);
                return snd_mixer_oss_free1(mixer);
        }
        return 0;
}

static int __init alsa_mixer_oss_init(void)
{
        struct snd_card *card;
        int idx;
        
        snd_mixer_oss_notify_callback = snd_mixer_oss_notify_handler;
        for (idx = 0; idx < SNDRV_CARDS; idx++) {
                card = snd_card_ref(idx);
                if (card) {
                        snd_mixer_oss_notify_handler(card, SND_MIXER_OSS_NOTIFY_REGISTER);
                        snd_card_unref(card);
                }
        }
        return 0;
}

static void __exit alsa_mixer_oss_exit(void)
{
        struct snd_card *card;
        int idx;

        snd_mixer_oss_notify_callback = NULL;
        for (idx = 0; idx < SNDRV_CARDS; idx++) {
                card = snd_card_ref(idx);
                if (card) {
                        snd_mixer_oss_notify_handler(card, SND_MIXER_OSS_NOTIFY_FREE);
                        snd_card_unref(card);
                }
        }
}

module_init(alsa_mixer_oss_init)
module_exit(alsa_mixer_oss_exit)