/*
 * Copyright 2001 MontaVista Software Inc.
 * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
 *
 *  arch/mips/ddb5xxx/ddb5477/irq.c
 *     The irq setup and misc routines for DDB5476.
 *
 * 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;  either version 2 of the  License, or (at your
 * option) any later version.
 */
#include <linux/config.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/types.h>
#include <linux/ptrace.h>

#include <asm/system.h>
#include <asm/mipsregs.h>
#include <asm/debug.h>

#include <asm/ddb5xxx/ddb5xxx.h>


/*
 * IRQ mapping
 *
 *  0-7: 8 CPU interrupts
 *	0 -	software interrupt 0
 *	1 - 	software interrupt 1
 *	2 - 	most Vrc5477 interrupts are routed to this pin
 *	3 - 	(optional) some other interrupts routed to this pin for debugg
 *	4 - 	not used
 *	5 - 	not used
 *	6 - 	not used
 *	7 - 	cpu timer (used by default)
 *
 *  8-39: 32 Vrc5477 interrupt sources
 *	(refer to the Vrc5477 manual)	
 */

#define	PCI0			DDB_INTPPES0
#define	PCI1			DDB_INTPPES1

#define	ACTIVE_LOW		1
#define	ACTIVE_HIGH		0

#define	LEVEL_SENSE		2
#define	EDGE_TRIGGER		0

#define	INTA			0
#define	INTB			1
#define	INTC			2
#define	INTD			3
#define	INTE			4

static inline void 
set_pci_int_attr(u32 pci, u32 intn, u32 active, u32 trigger)
{
	u32 reg_value;
	u32 reg_bitmask;

	reg_value = ddb_in32(pci);
	reg_bitmask = 0x3 << (intn * 2);
	
	reg_value &= ~reg_bitmask;
	reg_value |= (active | trigger) << (intn * 2);
	ddb_out32(pci, reg_value);
}

extern void vrc5477_irq_init(u32 base);
extern void mips_cpu_irq_init(u32 base);
extern asmlinkage void ddb5477_handle_int(void);

void
ddb5477_irq_setup(void)
{
	db_run(printk("ddb5477_irq_setup invoked.\n"));

	/* by default, we disable all interrupts and route all vrc5477 
	 * interrupts to pin 0 (irq 2) */
	ddb_out32(DDB_INTCTRL0, 0);
	ddb_out32(DDB_INTCTRL1, 0);
	ddb_out32(DDB_INTCTRL2, 0);
	ddb_out32(DDB_INTCTRL3, 0);

	clear_cp0_status(0xff00);
	set_cp0_status(0x0400);

	/* setup PCI interrupt attributes */
	set_pci_int_attr(PCI0, INTA, ACTIVE_LOW, LEVEL_SENSE);
	set_pci_int_attr(PCI0, INTB, ACTIVE_LOW, LEVEL_SENSE);
	set_pci_int_attr(PCI0, INTC, ACTIVE_LOW, LEVEL_SENSE);
	set_pci_int_attr(PCI0, INTD, ACTIVE_LOW, LEVEL_SENSE);
	set_pci_int_attr(PCI0, INTE, ACTIVE_LOW, LEVEL_SENSE);

	set_pci_int_attr(PCI1, INTA, ACTIVE_LOW, LEVEL_SENSE);
	set_pci_int_attr(PCI1, INTB, ACTIVE_LOW, LEVEL_SENSE);
	set_pci_int_attr(PCI1, INTC, ACTIVE_LOW, LEVEL_SENSE);
	set_pci_int_attr(PCI1, INTD, ACTIVE_LOW, LEVEL_SENSE);
	set_pci_int_attr(PCI1, INTE, ACTIVE_LOW, LEVEL_SENSE);

	/* 
	 * for debugging purpose, we enable several error interrupts
	 * and route them to pin 1. (IP3) 
	 */
	/* cpu parity check - 0 */
	ll_vrc5477_irq_route(0, 1); ll_vrc5477_irq_enable(0);
	/* cpu no-target decode - 1 */
	ll_vrc5477_irq_route(1, 1); ll_vrc5477_irq_enable(1);
	/* local bus read time-out - 7 */
	ll_vrc5477_irq_route(7, 1); ll_vrc5477_irq_enable(7);
	/* PCI SERR# - 14 */
	ll_vrc5477_irq_route(14, 1); ll_vrc5477_irq_enable(14);
	/* PCI internal error - 15 */
	ll_vrc5477_irq_route(15, 1); ll_vrc5477_irq_enable(15);
	/* IOPCI SERR# - 30 */
	ll_vrc5477_irq_route(30, 1); ll_vrc5477_irq_enable(30);
	/* IOPCI internal error - 31 */
	ll_vrc5477_irq_route(31, 1); ll_vrc5477_irq_enable(31);

	/* init all controllers */
	mips_cpu_irq_init(0);
	vrc5477_irq_init(8);

	/* hook up the first-level interrupt handler */
	set_except_vector(0, ddb5477_handle_int);
}

/*
 * the first level int-handler will jump here if it is a vrc5477 irq
 */
#define	NUM_5477_IRQS	32
asmlinkage void
vrc5477_irq_dispatch(struct pt_regs *regs)
{
	extern unsigned int do_IRQ(int irq, struct pt_regs *regs);

	u32 intStatus;
	u32 bitmask;
	u32 i;

	db_assert(ddb_in32(DDB_INT2STAT) == 0);
	db_assert(ddb_in32(DDB_INT3STAT) == 0);
	db_assert(ddb_in32(DDB_INT4STAT) == 0);
	db_assert(ddb_in32(DDB_NMISTAT) == 0);

	if (ddb_in32(DDB_INT1STAT) != 0) {
#if defined(CONFIG_DEBUG)
		vrc5477_show_int_regs();
#endif
		panic("error interrupt has happened.");
	}

	intStatus = ddb_in32(DDB_INT0STAT);
	for (i=0, bitmask=1; i<= NUM_5477_IRQS; bitmask <<=1, i++) {
		/* do we need to "and" with the int mask? */
		if (intStatus & bitmask) {
			do_IRQ(8 + i, regs);
		}
	}
}