/*
   * Copyright (C) 2002 Steve Schmidtke

   * Licensed under the GPL
   */

  #include <linux/fs.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/sound.h>
  #include <linux/soundcard.h>
  #include <linux/mutex.h>
  #include <asm/uaccess.h>
  #include <init.h>
  #include <os.h>

  
  struct hostaudio_state {

  	int fd;

  };
  
  struct hostmixer_state {

  	int fd;

  };
  
  #define HOSTAUDIO_DEV_DSP "/dev/sound/dsp"
  #define HOSTAUDIO_DEV_MIXER "/dev/sound/mixer"

  /*
   * Changed either at boot time or module load time.  At boot, this is

   * single-threaded; at module load, multiple modules would each have
   * their own copy of these variables.
   */
  static char *dsp = HOSTAUDIO_DEV_DSP;
  static char *mixer = HOSTAUDIO_DEV_MIXER;

  
  #define DSP_HELP \
  "    This is used to specify the host dsp device to the hostaudio driver.
  " \
  "    The default is \"" HOSTAUDIO_DEV_DSP "\".
  
  "
  
  #define MIXER_HELP \
  "    This is used to specify the host mixer device to the hostaudio driver.
  "\
  "    The default is \"" HOSTAUDIO_DEV_MIXER "\".
  
  "

  module_param(dsp, charp, 0644);
  MODULE_PARM_DESC(dsp, DSP_HELP);
  module_param(mixer, charp, 0644);
  MODULE_PARM_DESC(mixer, MIXER_HELP);

  #ifndef MODULE
  static int set_dsp(char *name, int *add)
  {
  	dsp = name;

  	return 0;

  }
  
  __uml_setup("dsp=", set_dsp, "dsp=<dsp device>
  " DSP_HELP);
  
  static int set_mixer(char *name, int *add)
  {
  	mixer = name;

  	return 0;

  }
  
  __uml_setup("mixer=", set_mixer, "mixer=<mixer device>
  " MIXER_HELP);

  #endif

  static DEFINE_MUTEX(hostaudio_mutex);

  /* /dev/dsp file operations */

  static ssize_t hostaudio_read(struct file *file, char __user *buffer,
  			      size_t count, loff_t *ppos)

  {

  	struct hostaudio_state *state = file->private_data;

  	void *kbuf;
  	int err;
  
  #ifdef DEBUG

  	printk(KERN_DEBUG "hostaudio: read called, count = %d
  ", count);

  #endif
  
  	kbuf = kmalloc(count, GFP_KERNEL);

  	if (kbuf == NULL)
  		return -ENOMEM;

  	err = os_read_file(state->fd, kbuf, count);

  	if (err < 0)

  		goto out;

  	if (copy_to_user(buffer, kbuf, err))

  		err = -EFAULT;

  out:

  	kfree(kbuf);

  	return err;

  }

  static ssize_t hostaudio_write(struct file *file, const char __user *buffer,

  			       size_t count, loff_t *ppos)
  {

  	struct hostaudio_state *state = file->private_data;

  	void *kbuf;
  	int err;
  
  #ifdef DEBUG

  	printk(KERN_DEBUG "hostaudio: write called, count = %d
  ", count);

  #endif
  
  	kbuf = kmalloc(count, GFP_KERNEL);

  	if (kbuf == NULL)
  		return -ENOMEM;

  
  	err = -EFAULT;

  	if (copy_from_user(kbuf, buffer, count))

  		goto out;

  	err = os_write_file(state->fd, kbuf, count);

  	if (err < 0)

  		goto out;
  	*ppos += err;
  
   out:
  	kfree(kbuf);

  	return err;

  }

  static unsigned int hostaudio_poll(struct file *file,

  				   struct poll_table_struct *wait)
  {

  	unsigned int mask = 0;

  
  #ifdef DEBUG

  	printk(KERN_DEBUG "hostaudio: poll called (unimplemented)
  ");

  #endif

  	return mask;

  }

  static long hostaudio_ioctl(struct file *file,

  			   unsigned int cmd, unsigned long arg)
  {

  	struct hostaudio_state *state = file->private_data;

  	unsigned long data = 0;
  	int err;
  
  #ifdef DEBUG

  	printk(KERN_DEBUG "hostaudio: ioctl called, cmd = %u
  ", cmd);

  #endif
  	switch(cmd){
  	case SNDCTL_DSP_SPEED:
  	case SNDCTL_DSP_STEREO:
  	case SNDCTL_DSP_GETBLKSIZE:
  	case SNDCTL_DSP_CHANNELS:
  	case SNDCTL_DSP_SUBDIVIDE:
  	case SNDCTL_DSP_SETFRAGMENT:

  		if (get_user(data, (int __user *) arg))

  			return -EFAULT;

  		break;
  	default:
  		break;
  	}
  
  	err = os_ioctl_generic(state->fd, cmd, (unsigned long) &data);
  
  	switch(cmd){
  	case SNDCTL_DSP_SPEED:
  	case SNDCTL_DSP_STEREO:
  	case SNDCTL_DSP_GETBLKSIZE:
  	case SNDCTL_DSP_CHANNELS:
  	case SNDCTL_DSP_SUBDIVIDE:
  	case SNDCTL_DSP_SETFRAGMENT:

  		if (put_user(data, (int __user *) arg))
  			return -EFAULT;

  		break;
  	default:
  		break;
  	}

  	return err;

  }
  
  static int hostaudio_open(struct inode *inode, struct file *file)
  {

  	struct hostaudio_state *state;
  	int r = 0, w = 0;
  	int ret;

  
  #ifdef DEBUG

  	kparam_block_sysfs_write(dsp);

  	printk(KERN_DEBUG "hostaudio: open called (host: %s)
  ", dsp);

  	kparam_unblock_sysfs_write(dsp);

  #endif

  	state = kmalloc(sizeof(struct hostaudio_state), GFP_KERNEL);

  	if (state == NULL)
  		return -ENOMEM;

  	if (file->f_mode & FMODE_READ)
  		r = 1;
  	if (file->f_mode & FMODE_WRITE)
  		w = 1;

  	kparam_block_sysfs_write(dsp);

  	mutex_lock(&hostaudio_mutex);

  	ret = os_open_file(dsp, of_set_rw(OPENFLAGS(), r, w), 0);

  	mutex_unlock(&hostaudio_mutex);

  	kparam_unblock_sysfs_write(dsp);

  	if (ret < 0) {

  		kfree(state);

  		return ret;

  	}

  	state->fd = ret;

  	file->private_data = state;

  	return 0;

  }
  
  static int hostaudio_release(struct inode *inode, struct file *file)
  {

  	struct hostaudio_state *state = file->private_data;

  
  #ifdef DEBUG

  	printk(KERN_DEBUG "hostaudio: release called
  ");

  #endif

  	os_close_file(state->fd);
  	kfree(state);

  	return 0;

  }
  
  /* /dev/mixer file operations */

  static long hostmixer_ioctl_mixdev(struct file *file,

  				  unsigned int cmd, unsigned long arg)
  {

  	struct hostmixer_state *state = file->private_data;

  
  #ifdef DEBUG

  	printk(KERN_DEBUG "hostmixer: ioctl called
  ");

  #endif

  	return os_ioctl_generic(state->fd, cmd, arg);

  }
  
  static int hostmixer_open_mixdev(struct inode *inode, struct file *file)
  {

  	struct hostmixer_state *state;
  	int r = 0, w = 0;
  	int ret;

  
  #ifdef DEBUG

  	printk(KERN_DEBUG "hostmixer: open called (host: %s)
  ", mixer);

  #endif

  	state = kmalloc(sizeof(struct hostmixer_state), GFP_KERNEL);

  	if (state == NULL)
  		return -ENOMEM;

  	if (file->f_mode & FMODE_READ)
  		r = 1;
  	if (file->f_mode & FMODE_WRITE)
  		w = 1;

  	kparam_block_sysfs_write(mixer);

  	mutex_lock(&hostaudio_mutex);

  	ret = os_open_file(mixer, of_set_rw(OPENFLAGS(), r, w), 0);

  	mutex_unlock(&hostaudio_mutex);

  	kparam_unblock_sysfs_write(mixer);

  
  	if (ret < 0) {

  		kparam_block_sysfs_write(dsp);

  		printk(KERN_ERR "hostaudio_open_mixdev failed to open '%s', "
  		       "err = %d
  ", dsp, -ret);

  		kparam_unblock_sysfs_write(dsp);

  		kfree(state);

  		return ret;

  	}

  	file->private_data = state;

  	return 0;

  }
  
  static int hostmixer_release(struct inode *inode, struct file *file)
  {

  	struct hostmixer_state *state = file->private_data;

  
  #ifdef DEBUG

  	printk(KERN_DEBUG "hostmixer: release called
  ");

  #endif

  	os_close_file(state->fd);
  	kfree(state);

  	return 0;

  }

  /* kernel module operations */

  static const struct file_operations hostaudio_fops = {

  	.owner          = THIS_MODULE,
  	.llseek         = no_llseek,
  	.read           = hostaudio_read,
  	.write          = hostaudio_write,
  	.poll           = hostaudio_poll,

  	.unlocked_ioctl	= hostaudio_ioctl,

  	.mmap           = NULL,
  	.open           = hostaudio_open,
  	.release        = hostaudio_release,

  };

  static const struct file_operations hostmixer_fops = {

  	.owner          = THIS_MODULE,
  	.llseek         = no_llseek,

  	.unlocked_ioctl	= hostmixer_ioctl_mixdev,

  	.open           = hostmixer_open_mixdev,
  	.release        = hostmixer_release,

  };
  
  struct {
  	int dev_audio;
  	int dev_mixer;
  } module_data;
  
  MODULE_AUTHOR("Steve Schmidtke");
  MODULE_DESCRIPTION("UML Audio Relay");
  MODULE_LICENSE("GPL");
  
  static int __init hostaudio_init_module(void)
  {

  	__kernel_param_lock();

  	printk(KERN_INFO "UML Audio Relay (host dsp = %s, host mixer = %s)
  ",

  	       dsp, mixer);

  	__kernel_param_unlock();

  
  	module_data.dev_audio = register_sound_dsp(&hostaudio_fops, -1);

  	if (module_data.dev_audio < 0) {

  		printk(KERN_ERR "hostaudio: couldn't register DSP device!
  ");
  		return -ENODEV;
  	}

  
  	module_data.dev_mixer = register_sound_mixer(&hostmixer_fops, -1);

  	if (module_data.dev_mixer < 0) {

  		printk(KERN_ERR "hostmixer: couldn't register mixer "

  		       "device!
  ");

  		unregister_sound_dsp(module_data.dev_audio);
  		return -ENODEV;
  	}

  	return 0;

  }
  
  static void __exit hostaudio_cleanup_module (void)
  {

  	unregister_sound_mixer(module_data.dev_mixer);
  	unregister_sound_dsp(module_data.dev_audio);

  }
  
  module_init(hostaudio_init_module);
  module_exit(hostaudio_cleanup_module);