1 /*
2 * arch/arm/mach-ns9xxx/irq.c
3 *
4 * Copyright (C) 2006,2007 by Digi International Inc.
5 * All rights reserved.
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 version 2 as published by
9 * the Free Software Foundation.
10 */
11 #include <linux/interrupt.h>
12 #include <linux/kernel_stat.h>
13 #include <linux/io.h>
14 #include <asm/mach/irq.h>
15 #include <mach/regs-sys-common.h>
16 #include <mach/irqs.h>
17 #include <mach/board.h>
18
19 #include "generic.h"
20
21 /* simple interrupt prio table: prio(x) < prio(y) <=> x < y */
22 #define irq2prio(i) (i)
23 #define prio2irq(p) (p)
24
ns9xxx_mask_irq(unsigned int irq)25 static void ns9xxx_mask_irq(unsigned int irq)
26 {
27 /* XXX: better use cpp symbols */
28 int prio = irq2prio(irq);
29 u32 ic = __raw_readl(SYS_IC(prio / 4));
30 ic &= ~(1 << (7 + 8 * (3 - (prio & 3))));
31 __raw_writel(ic, SYS_IC(prio / 4));
32 }
33
ns9xxx_ack_irq(unsigned int irq)34 static void ns9xxx_ack_irq(unsigned int irq)
35 {
36 __raw_writel(0, SYS_ISRADDR);
37 }
38
ns9xxx_maskack_irq(unsigned int irq)39 static void ns9xxx_maskack_irq(unsigned int irq)
40 {
41 ns9xxx_mask_irq(irq);
42 ns9xxx_ack_irq(irq);
43 }
44
ns9xxx_unmask_irq(unsigned int irq)45 static void ns9xxx_unmask_irq(unsigned int irq)
46 {
47 /* XXX: better use cpp symbols */
48 int prio = irq2prio(irq);
49 u32 ic = __raw_readl(SYS_IC(prio / 4));
50 ic |= 1 << (7 + 8 * (3 - (prio & 3)));
51 __raw_writel(ic, SYS_IC(prio / 4));
52 }
53
54 static struct irq_chip ns9xxx_chip = {
55 .ack = ns9xxx_ack_irq,
56 .mask = ns9xxx_mask_irq,
57 .mask_ack = ns9xxx_maskack_irq,
58 .unmask = ns9xxx_unmask_irq,
59 };
60
61 #if 0
62 #define handle_irq handle_level_irq
63 #else
handle_prio_irq(unsigned int irq,struct irq_desc * desc)64 static void handle_prio_irq(unsigned int irq, struct irq_desc *desc)
65 {
66 unsigned int cpu = smp_processor_id();
67 struct irqaction *action;
68 irqreturn_t action_ret;
69
70 spin_lock(&desc->lock);
71
72 BUG_ON(desc->status & IRQ_INPROGRESS);
73
74 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
75 kstat_cpu(cpu).irqs[irq]++;
76
77 action = desc->action;
78 if (unlikely(!action || (desc->status & IRQ_DISABLED)))
79 goto out_mask;
80
81 desc->status |= IRQ_INPROGRESS;
82 spin_unlock(&desc->lock);
83
84 action_ret = handle_IRQ_event(irq, action);
85
86 /* XXX: There is no direct way to access noirqdebug, so check
87 * unconditionally for spurious irqs...
88 * Maybe this function should go to kernel/irq/chip.c? */
89 note_interrupt(irq, desc, action_ret);
90
91 spin_lock(&desc->lock);
92 desc->status &= ~IRQ_INPROGRESS;
93
94 if (desc->status & IRQ_DISABLED)
95 out_mask:
96 desc->chip->mask(irq);
97
98 /* ack unconditionally to unmask lower prio irqs */
99 desc->chip->ack(irq);
100
101 spin_unlock(&desc->lock);
102 }
103 #define handle_irq handle_prio_irq
104 #endif
105
ns9xxx_init_irq(void)106 void __init ns9xxx_init_irq(void)
107 {
108 int i;
109
110 /* disable all IRQs */
111 for (i = 0; i < 8; ++i)
112 __raw_writel(prio2irq(4 * i) << 24 |
113 prio2irq(4 * i + 1) << 16 |
114 prio2irq(4 * i + 2) << 8 |
115 prio2irq(4 * i + 3),
116 SYS_IC(i));
117
118 for (i = 0; i < 32; ++i)
119 __raw_writel(prio2irq(i), SYS_IVA(i));
120
121 for (i = 0; i <= 31; ++i) {
122 set_irq_chip(i, &ns9xxx_chip);
123 set_irq_handler(i, handle_irq);
124 set_irq_flags(i, IRQF_VALID);
125 }
126 }
127