1. 根目录:
2. arch
3. arm
4. plat-omap
5. include
6. plat
7. mailbox.h

/* mailbox.h */

#ifndef MAILBOX_H
#define MAILBOX_H

#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/kfifo.h>

typedef u32 mbox_msg_t;
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 kfifo		fifo;
	struct work_struct	work;
	struct tasklet_struct	tasklet;
	struct omap_mbox	*mbox;
	bool full;
};

struct omap_mbox {
	char			*name;
	unsigned int		irq;
	struct omap_mbox_queue	*txq, *rxq;
	struct omap_mbox_ops	*ops;
	struct device		*dev;
	void			*priv;
	int			use_count;
	struct blocking_notifier_head   notifier;
};

int omap_mbox_msg_send(struct omap_mbox *, mbox_msg_t msg);
void omap_mbox_init_seq(struct omap_mbox *);

struct omap_mbox *omap_mbox_get(const char *, struct notifier_block *nb);
void omap_mbox_put(struct omap_mbox *mbox, struct notifier_block *nb);

int omap_mbox_register(struct device *parent, struct omap_mbox **);
int omap_mbox_unregister(void);

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);
}

static inline void omap_mbox_enable_irq(struct omap_mbox *mbox,
					omap_mbox_irq_t irq)
{
	mbox->ops->enable_irq(mbox, irq);
}

static inline void omap_mbox_disable_irq(struct omap_mbox *mbox,
					 omap_mbox_irq_t irq)
{
	mbox->ops->disable_irq(mbox, irq);
}

#endif /* MAILBOX_H */