irq-nvic.c
3.75 KB
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
139
140
141
142
143
144
145
146
147
/*
* drivers/irq/irq-nvic.c
*
* Copyright (C) 2008 ARM Limited, All Rights Reserved.
* Copyright (C) 2013 Pengutronix
*
* 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.
*
* Support for the Nested Vectored Interrupt Controller found on the
* ARMv7-M CPUs (Cortex-M3/M4)
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
#include <asm/v7m.h>
#include <asm/exception.h>
#define NVIC_ISER 0x000
#define NVIC_ICER 0x080
#define NVIC_IPR 0x300
#define NVIC_MAX_BANKS 16
/*
* Each bank handles 32 irqs. Only the 16th (= last) bank handles only
* 16 irqs.
*/
#define NVIC_MAX_IRQ ((NVIC_MAX_BANKS - 1) * 32 + 16)
static struct irq_domain *nvic_irq_domain;
asmlinkage void __exception_irq_entry
nvic_handle_irq(irq_hw_number_t hwirq, struct pt_regs *regs)
{
unsigned int irq = irq_linear_revmap(nvic_irq_domain, hwirq);
handle_IRQ(irq, regs);
}
static int nvic_irq_domain_translate(struct irq_domain *d,
struct irq_fwspec *fwspec,
unsigned long *hwirq, unsigned int *type)
{
if (WARN_ON(fwspec->param_count < 1))
return -EINVAL;
*hwirq = fwspec->param[0];
*type = IRQ_TYPE_NONE;
return 0;
}
static int nvic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs, void *arg)
{
int i, ret;
irq_hw_number_t hwirq;
unsigned int type = IRQ_TYPE_NONE;
struct irq_fwspec *fwspec = arg;
ret = nvic_irq_domain_translate(domain, fwspec, &hwirq, &type);
if (ret)
return ret;
for (i = 0; i < nr_irqs; i++)
irq_map_generic_chip(domain, virq + i, hwirq + i);
return 0;
}
static const struct irq_domain_ops nvic_irq_domain_ops = {
.translate = nvic_irq_domain_translate,
.alloc = nvic_irq_domain_alloc,
.free = irq_domain_free_irqs_top,
};
static int __init nvic_of_init(struct device_node *node,
struct device_node *parent)
{
unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
unsigned int irqs, i, ret, numbanks;
void __iomem *nvic_base;
numbanks = (readl_relaxed(V7M_SCS_ICTR) &
V7M_SCS_ICTR_INTLINESNUM_MASK) + 1;
nvic_base = of_iomap(node, 0);
if (!nvic_base) {
pr_warn("unable to map nvic registers\n");
return -ENOMEM;
}
irqs = numbanks * 32;
if (irqs > NVIC_MAX_IRQ)
irqs = NVIC_MAX_IRQ;
nvic_irq_domain =
irq_domain_add_linear(node, irqs, &nvic_irq_domain_ops, NULL);
if (!nvic_irq_domain) {
pr_warn("Failed to allocate irq domain\n");
return -ENOMEM;
}
ret = irq_alloc_domain_generic_chips(nvic_irq_domain, 32, 1,
"nvic_irq", handle_fasteoi_irq,
clr, 0, IRQ_GC_INIT_MASK_CACHE);
if (ret) {
pr_warn("Failed to allocate irq chips\n");
irq_domain_remove(nvic_irq_domain);
return ret;
}
for (i = 0; i < numbanks; ++i) {
struct irq_chip_generic *gc;
gc = irq_get_domain_generic_chip(nvic_irq_domain, 32 * i);
gc->reg_base = nvic_base + 4 * i;
gc->chip_types[0].regs.enable = NVIC_ISER;
gc->chip_types[0].regs.disable = NVIC_ICER;
gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
/* This is a no-op as end of interrupt is signaled by the
* exception return sequence.
*/
gc->chip_types[0].chip.irq_eoi = irq_gc_noop;
/* disable interrupts */
writel_relaxed(~0, gc->reg_base + NVIC_ICER);
}
/* Set priority on all interrupts */
for (i = 0; i < irqs; i += 4)
writel_relaxed(0, nvic_base + NVIC_IPR + i);
return 0;
}
IRQCHIP_DECLARE(armv7m_nvic, "arm,armv7m-nvic", nvic_of_init);