#ifndef __USBAUDIO_HELPER_H
  #define __USBAUDIO_HELPER_H
  
  unsigned int snd_usb_combine_bytes(unsigned char *bytes, int size);
  
  void *snd_usb_find_desc(void *descstart, int desclen, void *after, u8 dtype);
  void *snd_usb_find_csint_desc(void *descstart, int desclen, void *after, u8 dsubtype);
  
  int snd_usb_ctl_msg(struct usb_device *dev, unsigned int pipe,
  		    __u8 request, __u8 requesttype, __u16 value, __u16 index,

  		    void *data, __u16 size);

  
  unsigned char snd_usb_parse_datainterval(struct snd_usb_audio *chip,
  					 struct usb_host_interface *alts);
  
  /*
   * retrieve usb_interface descriptor from the host interface
   * (conditional for compatibility with the older API)
   */
  #ifndef get_iface_desc
  #define get_iface_desc(iface)	(&(iface)->desc)
  #define get_endpoint(alt,ep)	(&(alt)->endpoint[ep].desc)
  #define get_ep_desc(ep)		(&(ep)->desc)
  #define get_cfg_desc(cfg)	(&(cfg)->desc)
  #endif
  
  #ifndef snd_usb_get_speed
  #define snd_usb_get_speed(dev) ((dev)->speed)
  #endif

  static inline int snd_usb_ctrl_intf(struct snd_usb_audio *chip)
  {
  	return get_iface_desc(chip->ctrl_intf)->bInterfaceNumber;
  }

  
  #endif /* __USBAUDIO_HELPER_H */