text: /* mailbox.h */
  
  #ifndef MAILBOX_H
  #define MAILBOX_H
  
  #include <linux/wait.h>
  #include <linux/workqueue.h>
  #include <linux/blkdev.h>
  
  typedef u32 mbox_msg_t;
  typedef void (mbox_receiver_t)(mbox_msg_t msg);
  struct omap_mbox;
  
  typedef int __bitwise omap_mbox_irq_t;
  #define IRQ_TX ((__force omap_mbox_irq_t) 1)
  #define IRQ_RX ((__force omap_mbox_irq_t) 2)
  
  typedef int __bitwise omap_mbox_type_t;
  #define OMAP_MBOX_TYPE1 ((__force omap_mbox_type_t) 1)
  #define OMAP_MBOX_TYPE2 ((__force omap_mbox_type_t) 2)
  
  struct omap_mbox_ops {
  	omap_mbox_type_t	type;
  	int		(*startup)(struct omap_mbox *mbox);
  	void		(*shutdown)(struct omap_mbox *mbox);
  	/* fifo */
  	mbox_msg_t	(*fifo_read)(struct omap_mbox *mbox);
  	void		(*fifo_write)(struct omap_mbox *mbox, mbox_msg_t msg);
  	int		(*fifo_empty)(struct omap_mbox *mbox);
  	int		(*fifo_full)(struct omap_mbox *mbox);
  	/* irq */
  	void		(*enable_irq)(struct omap_mbox *mbox, omap_mbox_irq_t irq);
  	void		(*disable_irq)(struct omap_mbox *mbox, omap_mbox_irq_t irq);
  	void		(*ack_irq)(struct omap_mbox *mbox, omap_mbox_irq_t irq);
  	int		(*is_irq)(struct omap_mbox *mbox, omap_mbox_irq_t irq);
  	/* ctx */
  	void		(*save_ctx)(struct omap_mbox *mbox);
  	void		(*restore_ctx)(struct omap_mbox *mbox);
  };
  
  struct omap_mbox_queue {
  	spinlock_t		lock;
  	struct request_queue	*queue;
  	struct work_struct	work;
  	int	(*callback)(void *);
  	struct omap_mbox	*mbox;
  };
  
  struct omap_mbox {
  	char			*name;
  	unsigned int		irq;
  
  	struct omap_mbox_queue	*txq, *rxq;
  
  	struct omap_mbox_ops	*ops;
  
  	mbox_msg_t		seq_snd, seq_rcv;
  
  	struct device		*dev;
  
  	struct omap_mbox	*next;
  	void			*priv;
  
  	void			(*err_notify)(void);
  };
  
  int omap_mbox_msg_send(struct omap_mbox *, mbox_msg_t msg, void *);
  void omap_mbox_init_seq(struct omap_mbox *);
  
  struct omap_mbox *omap_mbox_get(const char *);
  void omap_mbox_put(struct omap_mbox *);
  
  int omap_mbox_register(struct device *parent, struct omap_mbox *);
  int omap_mbox_unregister(struct omap_mbox *);
  
  static inline void omap_mbox_save_ctx(struct omap_mbox *mbox)
  {
  	if (!mbox->ops->save_ctx) {
  		dev_err(mbox->dev, "%s:\tno save\n", __func__);
  		return;
  	}
  
  	mbox->ops->save_ctx(mbox);
  }
  
  static inline void omap_mbox_restore_ctx(struct omap_mbox *mbox)
  {
  	if (!mbox->ops->restore_ctx) {
  		dev_err(mbox->dev, "%s:\tno restore\n", __func__);
  		return;
  	}
  
  	mbox->ops->restore_ctx(mbox);
  }
  
  #endif /* MAILBOX_H */
  