Root/target/linux/adm5120/files/arch/mips/adm5120/common/irq.c

1/*
2 * ADM5120 specific interrupt handlers
3 *
4 * Copyright (C) 2007-2008 Gabor Juhos <juhosg@openwrt.org>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published
8 * by the Free Software Foundation.
9 *
10 */
11
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/version.h>
15#include <linux/irq.h>
16#include <linux/interrupt.h>
17#include <linux/ioport.h>
18#include <linux/io.h>
19
20#include <asm/irq_cpu.h>
21#include <asm/mipsregs.h>
22#include <asm/bitops.h>
23
24#include <asm/mach-adm5120/adm5120_defs.h>
25
26static void adm5120_intc_irq_unmask(unsigned int irq);
27static void adm5120_intc_irq_mask(unsigned int irq);
28static int adm5120_intc_irq_set_type(unsigned int irq, unsigned int flow_type);
29
30static inline void intc_write_reg(unsigned int reg, u32 val)
31{
32    void __iomem *base = (void __iomem *)KSEG1ADDR(ADM5120_INTC_BASE);
33
34    __raw_writel(val, base + reg);
35}
36
37static inline u32 intc_read_reg(unsigned int reg)
38{
39    void __iomem *base = (void __iomem *)KSEG1ADDR(ADM5120_INTC_BASE);
40
41    return __raw_readl(base + reg);
42}
43
44static struct irq_chip adm5120_intc_irq_chip = {
45    .name = "INTC",
46    .unmask = adm5120_intc_irq_unmask,
47    .mask = adm5120_intc_irq_mask,
48    .mask_ack = adm5120_intc_irq_mask,
49    .set_type = adm5120_intc_irq_set_type
50};
51
52static struct irqaction adm5120_intc_irq_action = {
53    .handler = no_action,
54    .name = "cascade [INTC]"
55};
56
57static void adm5120_intc_irq_unmask(unsigned int irq)
58{
59    irq -= ADM5120_INTC_IRQ_BASE;
60    intc_write_reg(INTC_REG_IRQ_ENABLE, 1 << irq);
61}
62
63static void adm5120_intc_irq_mask(unsigned int irq)
64{
65    irq -= ADM5120_INTC_IRQ_BASE;
66    intc_write_reg(INTC_REG_IRQ_DISABLE, 1 << irq);
67}
68
69static int adm5120_intc_irq_set_type(unsigned int irq, unsigned int flow_type)
70{
71    unsigned int sense;
72    unsigned long mode;
73    int err = 0;
74
75    sense = flow_type & (IRQ_TYPE_SENSE_MASK);
76    switch (sense) {
77    case IRQ_TYPE_NONE:
78    case IRQ_TYPE_LEVEL_HIGH:
79        break;
80    case IRQ_TYPE_LEVEL_LOW:
81        switch (irq) {
82        case ADM5120_IRQ_GPIO2:
83        case ADM5120_IRQ_GPIO4:
84            break;
85        default:
86            err = -EINVAL;
87            break;
88        }
89        break;
90    default:
91        err = -EINVAL;
92        break;
93    }
94
95    if (err)
96        return err;
97
98    switch (irq) {
99    case ADM5120_IRQ_GPIO2:
100    case ADM5120_IRQ_GPIO4:
101        mode = intc_read_reg(INTC_REG_INT_MODE);
102        if (sense == IRQ_TYPE_LEVEL_LOW)
103            mode |= (1 << (irq - ADM5120_INTC_IRQ_BASE));
104        else
105            mode &= ~(1 << (irq - ADM5120_INTC_IRQ_BASE));
106
107        intc_write_reg(INTC_REG_INT_MODE, mode);
108        /* fallthrough */
109    default:
110        irq_desc[irq].status &= ~IRQ_TYPE_SENSE_MASK;
111        irq_desc[irq].status |= sense;
112        break;
113    }
114
115    return 0;
116}
117
118static void adm5120_intc_irq_dispatch(void)
119{
120    unsigned long status;
121    int irq;
122
123    status = intc_read_reg(INTC_REG_IRQ_STATUS) & INTC_INT_ALL;
124    if (status) {
125        irq = ADM5120_INTC_IRQ_BASE + fls(status) - 1;
126        do_IRQ(irq);
127    } else
128        spurious_interrupt();
129}
130
131asmlinkage void plat_irq_dispatch(void)
132{
133    unsigned long pending;
134
135    pending = read_c0_status() & read_c0_cause() & ST0_IM;
136
137    if (pending & STATUSF_IP7)
138        do_IRQ(ADM5120_IRQ_COUNTER);
139    else if (pending & STATUSF_IP2)
140        adm5120_intc_irq_dispatch();
141    else
142        spurious_interrupt();
143}
144
145#define INTC_IRQ_STATUS (IRQ_LEVEL | IRQ_TYPE_LEVEL_HIGH | IRQ_DISABLED)
146static void __init adm5120_intc_irq_init(void)
147{
148    int i;
149
150    /* disable all interrupts */
151    intc_write_reg(INTC_REG_IRQ_DISABLE, INTC_INT_ALL);
152
153    /* setup all interrupts to generate IRQ instead of FIQ */
154    intc_write_reg(INTC_REG_INT_MODE, 0);
155
156    /* set active level for all external interrupts to HIGH */
157    intc_write_reg(INTC_REG_INT_LEVEL, 0);
158
159    /* disable usage of the TEST_SOURCE register */
160    intc_write_reg(INTC_REG_IRQ_SOURCE_SELECT, 0);
161
162    for (i = ADM5120_INTC_IRQ_BASE;
163        i <= ADM5120_INTC_IRQ_BASE + INTC_IRQ_LAST;
164        i++) {
165        irq_desc[i].status = INTC_IRQ_STATUS;
166        set_irq_chip_and_handler(i, &adm5120_intc_irq_chip,
167            handle_level_irq);
168    }
169
170    setup_irq(ADM5120_IRQ_INTC, &adm5120_intc_irq_action);
171}
172
173void __init arch_init_irq(void) {
174    mips_cpu_irq_init();
175    adm5120_intc_irq_init();
176}
177

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