// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   *  Hardware dependent layer

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

   */

  #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 <linux/sched/signal.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 <perex@perex.cz>");

  MODULE_DESCRIPTION("Hardware dependent layer");
  MODULE_LICENSE("GPL");

  static LIST_HEAD(snd_hwdep_devices);

  static DEFINE_MUTEX(register_mutex);

  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_entry_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 __poll_t 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 *info)

  {

  	int err;
  	
  	if (! hw->ops.dsp_load)
  		return -ENXIO;

  	if (info->index >= 32)

  		return -EINVAL;

  	/* check whether the dsp was already loaded */

  	if (hw->dsp_loaded & (1u << info->index))

  		return -EBUSY;

  	err = hw->ops.dsp_load(hw, info);

  	if (err < 0)
  		return err;

  	hw->dsp_loaded |= (1u << info->index);

  	return 0;
  }

  static int snd_hwdep_dsp_load_user(struct snd_hwdep *hw,
  				   struct snd_hwdep_dsp_image __user *_info)
  {
  	struct snd_hwdep_dsp_image info = {};
  
  	if (copy_from_user(&info, _info, sizeof(info)))
  		return -EFAULT;
  	return snd_hwdep_dsp_load(hw, &info);
  }

  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_user(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,
  };

  static void release_hwdep_device(struct device *dev)
  {
  	kfree(container_of(dev, struct snd_hwdep, dev));
  }

  /**
   * snd_hwdep_new - create a new hwdep instance
   * @card: the card instance
   * @id: the id string
   * @device: the device index (zero-based)
   * @rhwdep: the pointer to store the new hwdep instance
   *
   * Creates a new hwdep instance with the given index on the card.
   * The callbacks (hwdep->ops) must be set on the returned instance
   * after this call manually by the caller.
   *

   * Return: Zero if successful, or a negative error code on failure.

   */

  int snd_hwdep_new(struct snd_card *card, char *id, int device,
  		  struct snd_hwdep **rhwdep)

  {

  	struct snd_hwdep *hwdep;

  	int err;

  	static const 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)

  		return -ENOMEM;

  
  	init_waitqueue_head(&hwdep->open_wait);
  	mutex_init(&hwdep->open_mutex);

  	hwdep->card = card;
  	hwdep->device = device;

  	if (id)

  		strlcpy(hwdep->id, id, sizeof(hwdep->id));

  
  	snd_device_initialize(&hwdep->dev, card);
  	hwdep->dev.release = release_hwdep_device;
  	dev_set_name(&hwdep->dev, "hwC%iD%i", card->number, device);

  #ifdef CONFIG_SND_OSSEMUL
  	hwdep->oss_type = -1;
  #endif

  
  	err = snd_device_new(card, SNDRV_DEV_HWDEP, hwdep, &ops);
  	if (err < 0) {
  		put_device(&hwdep->dev);

  		return err;
  	}

  	if (rhwdep)
  		*rhwdep = hwdep;

  	return 0;
  }

  EXPORT_SYMBOL(snd_hwdep_new);

  static int snd_hwdep_dev_free(struct snd_device *device)

  {

  	struct snd_hwdep *hwdep = device->device_data;

  	if (!hwdep)
  		return 0;

  	if (hwdep->private_free)
  		hwdep->private_free(hwdep);

  	put_device(&hwdep->dev);

  	return 0;
  }

  static int snd_hwdep_dev_register(struct snd_device *device)

  {

  	struct snd_hwdep *hwdep = device->device_data;

  	struct snd_card *card = hwdep->card;

  	int err;

  	mutex_lock(&register_mutex);

  	if (snd_hwdep_search(card, hwdep->device)) {

  		mutex_unlock(&register_mutex);

  		return -EBUSY;
  	}

  	list_add_tail(&hwdep->list, &snd_hwdep_devices);

  	err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,
  				  hwdep->card, hwdep->device,
  				  &snd_hwdep_f_ops, hwdep, &hwdep->dev);

  	if (err < 0) {

  		dev_err(&hwdep->dev, "unable to register
  ");

  		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)
  			dev_warn(&hwdep->dev,

  				 "only hwdep device 0 can be registered as OSS direct FM device!
  ");

  		else if (snd_register_oss_device(hwdep->oss_type,
  						 card, hwdep->device,
  						 &snd_hwdep_f_ops, hwdep) < 0)
  			dev_warn(&hwdep->dev,
  				 "unable to register OSS compatibility 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(&hwdep->dev);

  	list_del_init(&hwdep->list);

  	mutex_unlock(&hwdep->open_mutex);

  	mutex_unlock(&register_mutex);

  	return 0;

  }

  #ifdef CONFIG_SND_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
  ",

  			    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_SND_PROC_FS */

  #define snd_hwdep_proc_init()
  #define snd_hwdep_proc_done()

  #endif /* CONFIG_SND_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)