1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
|
/*
* Copyright (C) 2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <asm/io.h>
#include "intc.h"
struct intc {
void __iomem *regs;
struct irq_chip chip;
};
extern struct platform_device at32_intc0_device;
/*
* TODO: We may be able to implement mask/unmask by setting IxM flags
* in the status register.
*/
static void intc_mask_irq(unsigned int irq)
{
}
static void intc_unmask_irq(unsigned int irq)
{
}
static struct intc intc0 = {
.chip = {
.name = "intc",
.mask = intc_mask_irq,
.unmask = intc_unmask_irq,
},
};
/*
* All interrupts go via intc at some point.
*/
asmlinkage void do_IRQ(int level, struct pt_regs *regs)
{
struct irq_desc *desc;
struct pt_regs *old_regs;
unsigned int irq;
unsigned long status_reg;
local_irq_disable();
old_regs = set_irq_regs(regs);
irq_enter();
irq = intc_readl(&intc0, INTCAUSE0 - 4 * level);
desc = irq_desc + irq;
desc->handle_irq(irq, desc);
/*
* Clear all interrupt level masks so that we may handle
* interrupts during softirq processing. If this is a nested
* interrupt, interrupts must stay globally disabled until we
* return.
*/
status_reg = sysreg_read(SR);
status_reg &= ~(SYSREG_BIT(I0M) | SYSREG_BIT(I1M)
| SYSREG_BIT(I2M) | SYSREG_BIT(I3M));
sysreg_write(SR, status_reg);
irq_exit();
set_irq_regs(old_regs);
}
void __init init_IRQ(void)
{
extern void _evba(void);
extern void irq_level0(void);
struct resource *regs;
struct clk *pclk;
unsigned int i;
u32 offset, readback;
regs = platform_get_resource(&at32_intc0_device, IORESOURCE_MEM, 0);
if (!regs) {
printk(KERN_EMERG "intc: no mmio resource defined\n");
goto fail;
}
pclk = clk_get(&at32_intc0_device.dev, "pclk");
if (IS_ERR(pclk)) {
printk(KERN_EMERG "intc: no clock defined\n");
goto fail;
}
clk_enable(pclk);
intc0.regs = ioremap(regs->start, regs->end - regs->start + 1);
if (!intc0.regs) {
printk(KERN_EMERG "intc: failed to map registers (0x%08lx)\n",
(unsigned long)regs->start);
goto fail;
}
/*
* Initialize all interrupts to level 0 (lowest priority). The
* priority level may be changed by calling
* irq_set_priority().
*
*/
offset = (unsigned long)&irq_level0 - (unsigned long)&_evba;
for (i = 0; i < NR_INTERNAL_IRQS; i++) {
intc_writel(&intc0, INTPR0 + 4 * i, offset);
readback = intc_readl(&intc0, INTPR0 + 4 * i);
if (readback == offset)
set_irq_chip_and_handler(i, &intc0.chip,
handle_simple_irq);
}
/* Unmask all interrupt levels */
sysreg_write(SR, (sysreg_read(SR)
& ~(SR_I3M | SR_I2M | SR_I1M | SR_I0M)));
return;
fail:
panic("Interrupt controller initialization failed!\n");
}
|
