#ifndef __USBMIXER_H
  #define __USBMIXER_H

  struct usb_mixer_interface {
  	struct snd_usb_audio *chip;

  	struct usb_host_interface *hostif;

  	struct list_head list;
  	unsigned int ignore_ctl_error;
  	struct urb *urb;
  	/* array[MAX_ID_ELEMS], indexed by unit id */
  	struct usb_mixer_elem_info **id_elems;

  	/* the usb audio specification version this interface complies to */
  	int protocol;

  	/* Sound Blaster remote control stuff */
  	const struct rc_config *rc_cfg;
  	u32 rc_code;
  	wait_queue_head_t rc_waitq;
  	struct urb *rc_urb;
  	struct usb_ctrlrequest *rc_setup_packet;
  	u8 rc_buffer[6];
  
  	u8 audigy2nx_leds[3];
  	u8 xonar_u1_status;
  };

  #define MAX_CHANNELS	16	/* max logical channels */
  
  enum {
  	USB_MIXER_BOOLEAN,
  	USB_MIXER_INV_BOOLEAN,
  	USB_MIXER_S8,
  	USB_MIXER_U8,
  	USB_MIXER_S16,
  	USB_MIXER_U16,
  };

  
  struct usb_mixer_elem_info {
  	struct usb_mixer_interface *mixer;
  	struct usb_mixer_elem_info *next_id_elem; /* list of controls with same id */
  	struct snd_ctl_elem_id *elem_id;
  	unsigned int id;
  	unsigned int control;	/* CS or ICN (high byte) */
  	unsigned int cmask; /* channel mask bitmap: 0 = master */

  	unsigned int ch_readonly;
  	unsigned int master_readonly;

  	int channels;
  	int val_type;
  	int min, max, res;
  	int dBmin, dBmax;
  	int cached;
  	int cache_val[MAX_CHANNELS];
  	u8 initialized;
  };

  int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
  			 int ignore_error);
  void snd_usb_mixer_disconnect(struct list_head *p);

  void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid);
  
  int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
  				int request, int validx, int value_set);

  void snd_usb_mixer_inactivate(struct usb_mixer_interface *mixer);
  int snd_usb_mixer_activate(struct usb_mixer_interface *mixer);

  int snd_usb_mixer_add_control(struct usb_mixer_interface *mixer,
  			      struct snd_kcontrol *kctl);

  #endif /* __USBMIXER_H */