Root/target/linux/amazon/files/arch/mips/amazon/interrupt.c

1/*
2 * Gary Jennejohn (C) 2003 <gj@denx.de>
3 * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
4 * Copyright (C) 2007 John Crispin <blogic@openwrt.org>
5 *
6 * This program is free software; you can distribute it and/or modify it
7 * under the terms of the GNU General Public License (Version 2) as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
18 *
19 * Routines for generic manipulation of the interrupts found on the
20 * AMAZON boards.
21 */
22
23#include <linux/init.h>
24#include <linux/sched.h>
25#include <linux/slab.h>
26#include <linux/interrupt.h>
27#include <linux/kernel_stat.h>
28#include <linux/module.h>
29
30#include <asm/amazon/amazon.h>
31#include <asm/amazon/irq.h>
32#include <asm/bootinfo.h>
33#include <asm/irq_cpu.h>
34#include <asm/irq.h>
35#include <asm/time.h>
36
37static void amazon_disable_irq(struct irq_data *d)
38{
39    int i;
40    u32 amazon_ier = AMAZON_ICU_IM0_IER;
41    unsigned int irq_nr = d->irq;
42
43    if (irq_nr <= INT_NUM_IM0_IRL11 && irq_nr >= INT_NUM_IM0_IRL0)
44        amazon_writel(amazon_readl(amazon_ier) & (~(AMAZON_DMA_H_MASK)), amazon_ier);
45    else {
46        irq_nr -= INT_NUM_IRQ0;
47        for (i = 0; i <= 4; i++)
48        {
49            if (irq_nr <= 31)
50                amazon_writel(amazon_readl(amazon_ier) & ~(1 << irq_nr ), amazon_ier);
51            amazon_ier += 0x10;
52            irq_nr -= 32;
53        }
54    }
55}
56
57static void amazon_mask_and_ack_irq(struct irq_data *d)
58{
59    int i;
60    u32 amazon_ier = AMAZON_ICU_IM0_IER;
61    u32 amazon_isr = AMAZON_ICU_IM0_ISR;
62    unsigned int irq_nr = d->irq;
63
64    if (irq_nr <= INT_NUM_IM0_IRL11 && irq_nr >= INT_NUM_IM0_IRL0){
65        amazon_writel(amazon_readl(amazon_ier) & (~(AMAZON_DMA_H_MASK)), amazon_ier);
66        amazon_writel(AMAZON_DMA_H_MASK, amazon_isr);
67    } else {
68        irq_nr -= INT_NUM_IRQ0;
69        for (i = 0; i <= 4; i++)
70        {
71            if (irq_nr <= 31){
72                amazon_writel(amazon_readl(amazon_ier) & ~(1 << irq_nr ), amazon_ier);
73                amazon_writel((1 << irq_nr ), amazon_isr);
74            }
75            amazon_ier += 0x10;
76            amazon_isr += 0x10;
77            irq_nr -= 32;
78        }
79    }
80}
81
82static void amazon_enable_irq(struct irq_data *d)
83{
84    int i;
85    u32 amazon_ier = AMAZON_ICU_IM0_IER;
86    unsigned int irq_nr = d->irq;
87
88    if (irq_nr <= INT_NUM_IM0_IRL11 && irq_nr >= INT_NUM_IM0_IRL0)
89        amazon_writel(amazon_readl(amazon_ier) | AMAZON_DMA_H_MASK, amazon_ier);
90    else {
91        irq_nr -= INT_NUM_IRQ0;
92        for (i = 0; i <= 4; i++)
93        {
94            if (irq_nr <= 31)
95                amazon_writel(amazon_readl(amazon_ier) | (1 << irq_nr ), amazon_ier);
96            amazon_ier += 0x10;
97            irq_nr -= 32;
98        }
99    }
100}
101
102static unsigned int amazon_startup_irq(struct irq_data *d)
103{
104    amazon_enable_irq(d);
105    return 0;
106}
107
108static struct irq_chip amazon_irq_type = {
109    .name = "AMAZON",
110    .irq_startup = amazon_startup_irq,
111    .irq_enable = amazon_enable_irq,
112    .irq_disable = amazon_disable_irq,
113    .irq_unmask = amazon_enable_irq,
114    .irq_ack = amazon_mask_and_ack_irq,
115    .irq_mask = amazon_disable_irq,
116    .irq_mask_ack = amazon_mask_and_ack_irq,
117};
118
119/* Cascaded interrupts from IM0-4 */
120static inline void amazon_hw_irqdispatch(u8 line)
121{
122    u32 irq;
123
124    irq = (amazon_readl(AMAZON_ICU_IM_VEC) >> (line * 5)) & AMAZON_ICU_IM0_VEC_MASK;
125    if (line == 0 && irq <= 11 && irq >= 0) {
126        //DMA fixed to IM0_IRL0
127        irq = 0;
128    }
129    do_IRQ(irq + INT_NUM_IRQ0 + (line * 32));
130}
131
132asmlinkage void plat_irq_dispatch(void)
133{
134    unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
135    if (pending & CAUSEF_IP7){
136        do_IRQ(MIPS_CPU_TIMER_IRQ);
137        goto out;
138    } else {
139        unsigned int i;
140        for (i = 0; i <= 4; i++)
141        {
142            if(pending & (CAUSEF_IP2 << i)){
143                amazon_hw_irqdispatch(i);
144                goto out;
145            }
146        }
147    }
148    printk("Spurious IRQ: CAUSE=0x%08x\n", read_c0_status());
149out:
150    return;
151}
152
153static struct irqaction cascade = {
154    .handler = no_action,
155    .flags = IRQF_DISABLED,
156    .name = "cascade",
157};
158
159void __init arch_init_irq(void)
160{
161    int i;
162
163    /* mask all interrupt sources */
164    for(i = 0; i <= 4; i++){
165        amazon_writel(0, AMAZON_ICU_IM0_IER + (i * 0x10));
166    }
167
168    mips_cpu_irq_init();
169
170    /* set up irq cascade */
171    for (i = 2; i <= 6; i++) {
172        setup_irq(i, &cascade);
173    }
174
175    for (i = INT_NUM_IRQ0; i <= INT_NUM_IM4_IRL31; i++)
176        irq_set_chip_and_handler(i, &amazon_irq_type,
177            handle_level_irq);
178
179    set_c0_status(IE_IRQ0 | IE_IRQ1 | IE_IRQ2 | IE_IRQ3 | IE_IRQ4 | IE_IRQ5);
180}
181
182void __cpuinit arch_fixup_c0_irqs(void)
183{
184    /* FIXME: check for CPUID and only do fix for specific chips/versions */
185    cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
186    cp0_perfcount_irq = CP0_LEGACY_PERFCNT_IRQ;
187}
188

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