1/*
2 * Copyright 2001 MontaVista Software Inc.
3 * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
4 *
5 *  arch/mips/ddb5xxx/ddb5477/irq.c
6 *     The irq setup and misc routines for DDB5476.
7 *
8 * This program is free software; you can redistribute  it and/or modify it
9 * under  the terms of  the GNU General  Public License as published by the
10 * Free Software Foundation;  either version 2 of the  License, or (at your
11 * option) any later version.
12 */
13#include <linux/init.h>
14#include <linux/interrupt.h>
15#include <linux/irq.h>
16#include <linux/types.h>
17#include <linux/ptrace.h>
18
19#include <asm/i8259.h>
20#include <asm/irq_cpu.h>
21#include <asm/system.h>
22#include <asm/mipsregs.h>
23#include <asm/debug.h>
24#include <asm/addrspace.h>
25#include <asm/bootinfo.h>
26
27#include <asm/ddb5xxx/ddb5xxx.h>
28
29
30/*
31 * IRQ mapping
32 *
33 *  0-7: 8 CPU interrupts
34 *	0 -	software interrupt 0
35 *	1 - 	software interrupt 1
36 *	2 - 	most Vrc5477 interrupts are routed to this pin
37 *	3 - 	(optional) some other interrupts routed to this pin for debugg
38 *	4 - 	not used
39 *	5 - 	not used
40 *	6 - 	not used
41 *	7 - 	cpu timer (used by default)
42 *
43 *  8-39: 32 Vrc5477 interrupt sources
44 *	(refer to the Vrc5477 manual)
45 */
46
47#define	PCI0			DDB_INTPPES0
48#define	PCI1			DDB_INTPPES1
49
50#define	ACTIVE_LOW		1
51#define	ACTIVE_HIGH		0
52
53#define	LEVEL_SENSE		2
54#define	EDGE_TRIGGER		0
55
56#define	INTA			0
57#define	INTB			1
58#define	INTC			2
59#define	INTD			3
60#define	INTE			4
61
62static inline void
63set_pci_int_attr(u32 pci, u32 intn, u32 active, u32 trigger)
64{
65	u32 reg_value;
66	u32 reg_bitmask;
67
68	reg_value = ddb_in32(pci);
69	reg_bitmask = 0x3 << (intn * 2);
70
71	reg_value &= ~reg_bitmask;
72	reg_value |= (active | trigger) << (intn * 2);
73	ddb_out32(pci, reg_value);
74}
75
76extern void vrc5477_irq_init(u32 base);
77static struct irqaction irq_cascade = { no_action, 0, CPU_MASK_NONE, "cascade", NULL, NULL };
78
79void __init arch_init_irq(void)
80{
81	/* by default, we disable all interrupts and route all vrc5477
82	 * interrupts to pin 0 (irq 2) */
83	ddb_out32(DDB_INTCTRL0, 0);
84	ddb_out32(DDB_INTCTRL1, 0);
85	ddb_out32(DDB_INTCTRL2, 0);
86	ddb_out32(DDB_INTCTRL3, 0);
87
88	clear_c0_status(0xff00);
89	set_c0_status(0x0400);
90
91	/* setup PCI interrupt attributes */
92	set_pci_int_attr(PCI0, INTA, ACTIVE_LOW, LEVEL_SENSE);
93	set_pci_int_attr(PCI0, INTB, ACTIVE_LOW, LEVEL_SENSE);
94	if (mips_machtype == MACH_NEC_ROCKHOPPERII)
95		set_pci_int_attr(PCI0, INTC, ACTIVE_HIGH, LEVEL_SENSE);
96	else
97		set_pci_int_attr(PCI0, INTC, ACTIVE_LOW, LEVEL_SENSE);
98	set_pci_int_attr(PCI0, INTD, ACTIVE_LOW, LEVEL_SENSE);
99	set_pci_int_attr(PCI0, INTE, ACTIVE_LOW, LEVEL_SENSE);
100
101	set_pci_int_attr(PCI1, INTA, ACTIVE_LOW, LEVEL_SENSE);
102	set_pci_int_attr(PCI1, INTB, ACTIVE_LOW, LEVEL_SENSE);
103	set_pci_int_attr(PCI1, INTC, ACTIVE_LOW, LEVEL_SENSE);
104	set_pci_int_attr(PCI1, INTD, ACTIVE_LOW, LEVEL_SENSE);
105	set_pci_int_attr(PCI1, INTE, ACTIVE_LOW, LEVEL_SENSE);
106
107	/*
108	 * for debugging purpose, we enable several error interrupts
109	 * and route them to pin 1. (IP3)
110	 */
111	/* cpu parity check - 0 */
112	ll_vrc5477_irq_route(0, 1); ll_vrc5477_irq_enable(0);
113	/* cpu no-target decode - 1 */
114	ll_vrc5477_irq_route(1, 1); ll_vrc5477_irq_enable(1);
115	/* local bus read time-out - 7 */
116	ll_vrc5477_irq_route(7, 1); ll_vrc5477_irq_enable(7);
117	/* PCI SERR# - 14 */
118	ll_vrc5477_irq_route(14, 1); ll_vrc5477_irq_enable(14);
119	/* PCI internal error - 15 */
120	ll_vrc5477_irq_route(15, 1); ll_vrc5477_irq_enable(15);
121	/* IOPCI SERR# - 30 */
122	ll_vrc5477_irq_route(30, 1); ll_vrc5477_irq_enable(30);
123	/* IOPCI internal error - 31 */
124	ll_vrc5477_irq_route(31, 1); ll_vrc5477_irq_enable(31);
125
126	/* init all controllers */
127	init_i8259_irqs();
128	mips_cpu_irq_init();
129	vrc5477_irq_init(VRC5477_IRQ_BASE);
130
131
132	/* setup cascade interrupts */
133	setup_irq(VRC5477_IRQ_BASE + VRC5477_I8259_CASCADE, &irq_cascade);
134	setup_irq(CPU_IRQ_BASE + CPU_VRC5477_CASCADE, &irq_cascade);
135}
136
137u8 i8259_interrupt_ack(void)
138{
139	u8 irq;
140	u32 reg;
141
142	/* Set window 0 for interrupt acknowledge */
143	reg = ddb_in32(DDB_PCIINIT10);
144
145	ddb_set_pmr(DDB_PCIINIT10, DDB_PCICMD_IACK, 0, DDB_PCI_ACCESS_32);
146	irq = *(volatile u8 *) KSEG1ADDR(DDB_PCI_IACK_BASE);
147	ddb_out32(DDB_PCIINIT10, reg);
148
149	return irq;
150}
151/*
152 * the first level int-handler will jump here if it is a vrc5477 irq
153 */
154#define	NUM_5477_IRQS	32
155static void vrc5477_irq_dispatch(void)
156{
157	u32 intStatus;
158	u32 bitmask;
159	u32 i;
160
161	db_assert(ddb_in32(DDB_INT2STAT) == 0);
162	db_assert(ddb_in32(DDB_INT3STAT) == 0);
163	db_assert(ddb_in32(DDB_INT4STAT) == 0);
164	db_assert(ddb_in32(DDB_NMISTAT) == 0);
165
166	if (ddb_in32(DDB_INT1STAT) != 0) {
167#if defined(CONFIG_RUNTIME_DEBUG)
168		vrc5477_show_int_regs();
169#endif
170		panic("error interrupt has happened.");
171	}
172
173	intStatus = ddb_in32(DDB_INT0STAT);
174
175	if (mips_machtype == MACH_NEC_ROCKHOPPERII) {
176		/* check for i8259 interrupts */
177		if (intStatus & (1 << VRC5477_I8259_CASCADE)) {
178			int i8259_irq = i8259_interrupt_ack();
179			do_IRQ(i8259_irq);
180			return;
181		}
182	}
183
184	for (i=0, bitmask=1; i<= NUM_5477_IRQS; bitmask <<=1, i++) {
185		/* do we need to "and" with the int mask? */
186		if (intStatus & bitmask) {
187			do_IRQ(VRC5477_IRQ_BASE + i);
188			return;
189		}
190	}
191}
192
193#define VR5477INTS (STATUSF_IP2|STATUSF_IP3|STATUSF_IP4|STATUSF_IP5|STATUSF_IP6)
194
195asmlinkage void plat_irq_dispatch(void)
196{
197	unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;
198
199	if (pending & STATUSF_IP7)
200		do_IRQ(CPU_IRQ_BASE + 7);
201	else if (pending & VR5477INTS)
202		vrc5477_irq_dispatch();
203	else if (pending & STATUSF_IP0)
204		do_IRQ(CPU_IRQ_BASE);
205	else if (pending & STATUSF_IP1)
206		do_IRQ(CPU_IRQ_BASE + 1);
207	else
208		spurious_interrupt();
209}
210