// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * OSS compatible sequencer driver
 *
 * registration of device and proc
 *
 * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/compat.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/initval.h>
#include "seq_oss_device.h"
#include "seq_oss_synth.h"

/*
 * module option
 */
MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
MODULE_DESCRIPTION("OSS-compatible sequencer module");
MODULE_LICENSE("GPL");
/* Takashi says this is really only for sound-service-0-, but this is OK. */
MODULE_ALIAS_SNDRV_MINOR(SNDRV_MINOR_OSS_SEQUENCER);
MODULE_ALIAS_SNDRV_MINOR(SNDRV_MINOR_OSS_MUSIC);


/*
 * prototypes
 */
static int register_device(void);
static void unregister_device(void);
#ifdef CONFIG_SND_PROC_FS
static int register_proc(void);
static void unregister_proc(void);
#else
static inline int register_proc(void) { return 0; }
static inline void unregister_proc(void) {}
#endif

static int odev_open(struct inode *inode, struct file *file);
static int odev_release(struct inode *inode, struct file *file);
static ssize_t odev_read(struct file *file, char __user *buf, size_t count, loff_t *offset);
static ssize_t odev_write(struct file *file, const char __user *buf, size_t count, loff_t *offset);
static long odev_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
static __poll_t odev_poll(struct file *file, poll_table * wait);


/*
 * module interface
 */

static struct snd_seq_driver seq_oss_synth_driver = {
        .probe = snd_seq_oss_synth_probe,
        .remove = snd_seq_oss_synth_remove,
        .driver = {
                .name = KBUILD_MODNAME,
        },
        .id = SNDRV_SEQ_DEV_ID_OSS,
        .argsize = sizeof(struct snd_seq_oss_reg),
};

static int __init alsa_seq_oss_init(void)
{
        int rc;

        rc = register_device();
        if (rc < 0)
                goto error;
        rc = register_proc();
        if (rc < 0) {
                unregister_device();
                goto error;
        }
        rc = snd_seq_oss_create_client();
        if (rc < 0) {
                unregister_proc();
                unregister_device();
                goto error;
        }

        rc = snd_seq_driver_register(&seq_oss_synth_driver);
        if (rc < 0) {
                snd_seq_oss_delete_client();
                unregister_proc();
                unregister_device();
                goto error;
        }

        /* success */
        snd_seq_oss_synth_init();

 error:
        return rc;
}

static void __exit alsa_seq_oss_exit(void)
{
        snd_seq_driver_unregister(&seq_oss_synth_driver);
        snd_seq_oss_delete_client();
        unregister_proc();
        unregister_device();
}

module_init(alsa_seq_oss_init)
module_exit(alsa_seq_oss_exit)

/*
 * ALSA minor device interface
 */

static DEFINE_MUTEX(register_mutex);

static int
odev_open(struct inode *inode, struct file *file)
{
        int level;

        if (iminor(inode) == SNDRV_MINOR_OSS_MUSIC)
                level = SNDRV_SEQ_OSS_MODE_MUSIC;
        else
                level = SNDRV_SEQ_OSS_MODE_SYNTH;

        guard(mutex)(&register_mutex);
        return snd_seq_oss_open(file, level);
}

static int
odev_release(struct inode *inode, struct file *file)
{
        struct seq_oss_devinfo *dp;

        dp = file->private_data;
        if (!dp)
                return 0;

        guard(mutex)(&register_mutex);
        snd_seq_oss_release(dp);
        return 0;
}

static ssize_t
odev_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
{
        struct seq_oss_devinfo *dp;
        dp = file->private_data;
        if (snd_BUG_ON(!dp))
                return -ENXIO;
        return snd_seq_oss_read(dp, buf, count);
}


static ssize_t
odev_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
{
        struct seq_oss_devinfo *dp;
        dp = file->private_data;
        if (snd_BUG_ON(!dp))
                return -ENXIO;
        return snd_seq_oss_write(dp, buf, count, file);
}

static long
odev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
        struct seq_oss_devinfo *dp;
        long rc;

        dp = file->private_data;
        if (snd_BUG_ON(!dp))
                return -ENXIO;

        if (cmd != SNDCTL_SEQ_SYNC &&
            mutex_lock_interruptible(&register_mutex))
                return -ERESTARTSYS;
        rc = snd_seq_oss_ioctl(dp, cmd, arg);
        if (cmd != SNDCTL_SEQ_SYNC)
                mutex_unlock(&register_mutex);
        return rc;
}

#ifdef CONFIG_COMPAT
static long odev_ioctl_compat(struct file *file, unsigned int cmd,
                              unsigned long arg)
{
        return odev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
}
#else
#define odev_ioctl_compat       NULL
#endif

static __poll_t
odev_poll(struct file *file, poll_table * wait)
{
        struct seq_oss_devinfo *dp;
        dp = file->private_data;
        if (snd_BUG_ON(!dp))
                return EPOLLERR;
        return snd_seq_oss_poll(dp, file, wait);
}

/*
 * registration of sequencer minor device
 */

static const struct file_operations seq_oss_f_ops =
{
        .owner =        THIS_MODULE,
        .read =         odev_read,
        .write =        odev_write,
        .open =         odev_open,
        .release =      odev_release,
        .poll =         odev_poll,
        .unlocked_ioctl =       odev_ioctl,
        .compat_ioctl = odev_ioctl_compat,
        .llseek =       noop_llseek,
};

static int __init
register_device(void)
{
        int rc;

        guard(mutex)(&register_mutex);
        rc = snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_SEQUENCER,
                                     NULL, 0,
                                     &seq_oss_f_ops, NULL);
        if (rc < 0) {
                pr_err("ALSA: seq_oss: can't register device seq\n");
                return rc;
        }
        rc = snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_MUSIC,
                                     NULL, 0,
                                     &seq_oss_f_ops, NULL);
        if (rc < 0) {
                pr_err("ALSA: seq_oss: can't register device music\n");
                snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_SEQUENCER, NULL, 0);
                return rc;
        }
        return 0;
}

static void
unregister_device(void)
{
        guard(mutex)(&register_mutex);
        if (snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_MUSIC, NULL, 0) < 0)                
                pr_err("ALSA: seq_oss: error unregister device music\n");
        if (snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_SEQUENCER, NULL, 0) < 0)
                pr_err("ALSA: seq_oss: error unregister device seq\n");
}

/*
 * /proc interface
 */

#ifdef CONFIG_SND_PROC_FS

static struct snd_info_entry *info_entry;

static void
info_read(struct snd_info_entry *entry, struct snd_info_buffer *buf)
{
        guard(mutex)(&register_mutex);
        snd_iprintf(buf, "OSS sequencer emulation version %s\n", SNDRV_SEQ_OSS_VERSION_STR);
        snd_seq_oss_system_info_read(buf);
        snd_seq_oss_synth_info_read(buf);
        snd_seq_oss_midi_info_read(buf);
}


static int __init
register_proc(void)
{
        struct snd_info_entry *entry;

        entry = snd_info_create_module_entry(THIS_MODULE, SNDRV_SEQ_OSS_PROCNAME, snd_seq_root);
        if (entry == NULL)
                return -ENOMEM;

        entry->content = SNDRV_INFO_CONTENT_TEXT;
        entry->private_data = NULL;
        entry->c.text.read = info_read;
        if (snd_info_register(entry) < 0) {
                snd_info_free_entry(entry);
                return -ENOMEM;
        }
        info_entry = entry;
        return 0;
}

static void
unregister_proc(void)
{
        snd_info_free_entry(info_entry);
        info_entry = NULL;
}
#endif /* CONFIG_SND_PROC_FS */