/*
* Copyright 2011-2012, Meador Inge, Mentor Graphics Corporation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; version 2 of the
* License.
*
*/

#ifndef _ASM_MPIC_MSGR_H
#define _ASM_MPIC_MSGR_H

#include <linux/types.h>
#include <linux/spinlock.h>
#include <asm/smp.h>
#include <asm/io.h>

struct mpic_msgr {
u32 __iomem *base;
u32 __iomem *mer;
int irq;
unsigned char in_use;
raw_spinlock_t lock;
int num;
};

/* Get a message register
*
* @reg_num: the MPIC message register to get
*
* A pointer to the message register is returned. If
* the message register asked for is already in use, then
* EBUSY is returned. If the number given is not associated
* with an actual message register, then ENODEV is returned.
* Successfully getting the register marks it as in use.
*/
extern struct mpic_msgr *mpic_msgr_get(unsigned int reg_num);

/* Relinquish a message register
*
* @msgr: the message register to return
*
* Disables the given message register and marks it as free.
* After this call has completed successully the message
* register is available to be acquired by a call to
* mpic_msgr_get.
*/
extern void mpic_msgr_put(struct mpic_msgr *msgr);

/* Enable a message register
*
* @msgr: the message register to enable
*
* The given message register is enabled for sending
* messages.
*/
extern void mpic_msgr_enable(struct mpic_msgr *msgr);

/* Disable a message register
*
* @msgr: the message register to disable
*
* The given message register is disabled for sending
* messages.
*/
extern void mpic_msgr_disable(struct mpic_msgr *msgr);

/* Write a message to a message register
*
* @msgr: the message register to write to
* @message: the message to write
*
* The given 32-bit message is written to the given message
* register. Writing to an enabled message registers fires
* an interrupt.
*/
static inline void mpic_msgr_write(struct mpic_msgr *msgr, u32 message)
{
out_be32(msgr->base, message);
}

/* Read a message from a message register
*
* @msgr: the message register to read from
*
* Returns the 32-bit value currently in the given message register.
* Upon reading the register any interrupts for that register are
* cleared.
*/
static inline u32 mpic_msgr_read(struct mpic_msgr *msgr)
{
return in_be32(msgr->base);
}

/* Clear a message register
*
* @msgr: the message register to clear
*
* Clears any interrupts associated with the given message register.
*/
static inline void mpic_msgr_clear(struct mpic_msgr *msgr)
{
(void) mpic_msgr_read(msgr);
}

/* Set the destination CPU for the message register
*
* @msgr: the message register whose destination is to be set
* @cpu_num: the Linux CPU number to bind the message register to
*
* Note that the CPU number given is the CPU number used by the kernel
* and *not* the actual hardware CPU number.
*/
static inline void mpic_msgr_set_destination(struct mpic_msgr *msgr,
u32 cpu_num)
{
out_be32(msgr->base, 1 << get_hard_smp_processor_id(cpu_num));
}

/* Get the IRQ number for the message register
* @msgr: the message register whose IRQ is to be returned
*
* Returns the IRQ number associated with the given message register.
* NO_IRQ is returned if this message register is not capable of
* receiving interrupts. What message register can and cannot receive
* interrupts is specified in the device tree for the system.
*/
static inline int mpic_msgr_get_irq(struct mpic_msgr *msgr)
{
return msgr->irq;
}

#endif