1 /*
2  * irq.c: GT64120 Interrupt Controller
3  *
4  * Copyright (C) 2006, Wind River System Inc.
5  * Author: Rongkai.Zhan, <rongkai.zhan@windriver.com>
6  *
7  * This program is free software; you can redistribute  it and/or modify it
8  * under  the terms of  the GNU General  Public License as published by the
9  * Free Software Foundation;  either version 2 of the  License, or (at your
10  * option) any later version.
11  */
12 #include <linux/hardirq.h>
13 #include <linux/init.h>
14 #include <linux/irq.h>
15 
16 #include <asm/gt64120.h>
17 #include <asm/irq_cpu.h>
18 #include <asm/mipsregs.h>
19 
plat_irq_dispatch(void)20 asmlinkage void plat_irq_dispatch(void)
21 {
22 	unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
23 
24 	if (pending & STATUSF_IP7)
25 		do_IRQ(WRPPMC_MIPS_TIMER_IRQ);	/* CPU Compare/Count internal timer */
26 	else if (pending & STATUSF_IP6)
27 		do_IRQ(WRPPMC_UART16550_IRQ);	/* UART 16550 port */
28 	else if (pending & STATUSF_IP3)
29 		do_IRQ(WRPPMC_PCI_INTA_IRQ);	/* PCI INT_A */
30 	else
31 		spurious_interrupt();
32 }
33 
34 /**
35  * Initialize GT64120 Interrupt Controller
36  */
gt64120_init_pic(void)37 void gt64120_init_pic(void)
38 {
39 	/* clear CPU Interrupt Cause Registers */
40 	GT_WRITE(GT_INTRCAUSE_OFS, (0x1F << 21));
41 	GT_WRITE(GT_HINTRCAUSE_OFS, 0x00);
42 
43 	/* Disable all interrupts from GT64120 bridge chip */
44 	GT_WRITE(GT_INTRMASK_OFS, 0x00);
45 	GT_WRITE(GT_HINTRMASK_OFS, 0x00);
46 	GT_WRITE(GT_PCI0_ICMASK_OFS, 0x00);
47 	GT_WRITE(GT_PCI0_HICMASK_OFS, 0x00);
48 }
49 
arch_init_irq(void)50 void __init arch_init_irq(void)
51 {
52 	/* IRQ 0 - 7 are for MIPS common irq_cpu controller */
53 	mips_cpu_irq_init();
54 
55 	gt64120_init_pic();
56 }
57