mailbox/omap: move the OMAP mailbox framework to drivers

The mailbox hardware (in OMAP) uses a queued mailbox interrupt
mechanism that provides a communication channel between processors
through a set of registers and their associated interrupt signals
by sending and receiving messages.

The OMAP mailbox framework/driver code is moved to be under
drivers/mailbox, in preparation for adapting to a common mailbox
driver framework. This allows the build for OMAP mailbox to be
enabled (it was disabled during the multi-platform support).

As part of the migration from plat and mach code:
- Kconfig symbols have been renamed to build OMAP1 or OMAP2+ drivers.
- mailbox.h under plat-omap/plat/include has been split into a public
  and private header files. The public header has only the API related
  functions and types.
- The module name mailbox.ko from plat-omap is changed to
  omap-mailbox.ko
- The module name mailbox_mach.ko from mach-omapX is changed as
    mailbox_omap1.ko for OMAP1
    mailbox_omap2.ko for OMAP2+

Cc: Tony Lindgren <tony@atomide.com>
[gregkh@linuxfoundation.org: ack for staging part]
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Omar Ramirez Luna <omar.ramirez@copitl.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
diff --git a/drivers/mailbox/omap-mbox.h b/drivers/mailbox/omap-mbox.h
new file mode 100644
index 0000000..6cd38fc
--- /dev/null
+++ b/drivers/mailbox/omap-mbox.h
@@ -0,0 +1,67 @@
+/*
+ * omap-mbox.h: OMAP mailbox internal definitions
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef OMAP_MBOX_H
+#define OMAP_MBOX_H
+
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/kfifo.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <linux/omap-mailbox.h>
+
+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 {
+	const 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_register(struct device *parent, struct omap_mbox **);
+int omap_mbox_unregister(void);
+
+#endif /* OMAP_MBOX_H */