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
148
149
150
151
152
153
154
155
156
157
158
|
/*
* Support for Versatile FPGA-based IRQ controllers
*/
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/irqdomain.h>
#include <linux/module.h>
#include <asm/exception.h>
#include <asm/mach/irq.h>
#include <plat/fpga-irq.h>
#define IRQ_STATUS 0x00
#define IRQ_RAW_STATUS 0x04
#define IRQ_ENABLE_SET 0x08
#define IRQ_ENABLE_CLEAR 0x0c
/**
* struct fpga_irq_data - irq data container for the FPGA IRQ controller
* @base: memory offset in virtual memory
* @irq_start: first IRQ number handled by this instance
* @chip: chip container for this instance
* @domain: IRQ domain for this instance
* @valid: mask for valid IRQs on this controller
* @used_irqs: number of active IRQs on this controller
*/
struct fpga_irq_data {
void __iomem *base;
unsigned int irq_start;
struct irq_chip chip;
u32 valid;
struct irq_domain *domain;
u8 used_irqs;
};
/* we cannot allocate memory when the controllers are initially registered */
static struct fpga_irq_data fpga_irq_devices[CONFIG_PLAT_VERSATILE_FPGA_IRQ_NR];
static int fpga_irq_id;
static void fpga_irq_mask(struct irq_data *d)
{
struct fpga_irq_data *f = irq_data_get_irq_chip_data(d);
u32 mask = 1 << d->hwirq;
writel(mask, f->base + IRQ_ENABLE_CLEAR);
}
static void fpga_irq_unmask(struct irq_data *d)
{
struct fpga_irq_data *f = irq_data_get_irq_chip_data(d);
u32 mask = 1 << d->hwirq;
writel(mask, f->base + IRQ_ENABLE_SET);
}
static void fpga_irq_handle(unsigned int irq, struct irq_desc *desc)
{
struct fpga_irq_data *f = irq_desc_get_handler_data(desc);
u32 status = readl(f->base + IRQ_STATUS);
if (status == 0) {
do_bad_IRQ(irq, desc);
return;
}
do {
irq = ffs(status) - 1;
status &= ~(1 << irq);
generic_handle_irq(irq_find_mapping(f->domain, irq));
} while (status);
}
/*
* Handle each interrupt in a single FPGA IRQ controller. Returns non-zero
* if we've handled at least one interrupt. This does a single read of the
* status register and handles all interrupts in order from LSB first.
*/
static int handle_one_fpga(struct fpga_irq_data *f, struct pt_regs *regs)
{
int handled = 0;
int irq;
u32 status;
while ((status = readl(f->base + IRQ_STATUS))) {
irq = ffs(status) - 1;
handle_IRQ(irq_find_mapping(f->domain, irq), regs);
handled = 1;
}
return handled;
}
/*
* Keep iterating over all registered FPGA IRQ controllers until there are
* no pending interrupts.
*/
asmlinkage void __exception_irq_entry fpga_handle_irq(struct pt_regs *regs)
{
int i, handled;
do {
for (i = 0, handled = 0; i < fpga_irq_id; ++i)
handled |= handle_one_fpga(&fpga_irq_devices[i], regs);
} while (handled);
}
static int fpga_irqdomain_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hwirq)
{
struct fpga_irq_data *f = d->host_data;
/* Skip invalid IRQs, only register handlers for the real ones */
if (!(f->valid & (1 << hwirq)))
return -ENOTSUPP;
irq_set_chip_data(irq, f);
irq_set_chip_and_handler(irq, &f->chip,
handle_level_irq);
set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
f->used_irqs++;
return 0;
}
static struct irq_domain_ops fpga_irqdomain_ops = {
.map = fpga_irqdomain_map,
.xlate = irq_domain_xlate_onetwocell,
};
void __init fpga_irq_init(void __iomem *base, const char *name, int irq_start,
int parent_irq, u32 valid, struct device_node *node)
{
struct fpga_irq_data *f;
if (fpga_irq_id >= ARRAY_SIZE(fpga_irq_devices)) {
printk(KERN_ERR "%s: too few FPGA IRQ controllers, increase CONFIG_PLAT_VERSATILE_FPGA_IRQ_NR\n", __func__);
return;
}
f = &fpga_irq_devices[fpga_irq_id];
f->base = base;
f->irq_start = irq_start;
f->chip.name = name;
f->chip.irq_ack = fpga_irq_mask;
f->chip.irq_mask = fpga_irq_mask;
f->chip.irq_unmask = fpga_irq_unmask;
f->valid = valid;
if (parent_irq != -1) {
irq_set_handler_data(parent_irq, f);
irq_set_chained_handler(parent_irq, fpga_irq_handle);
}
f->domain = irq_domain_add_legacy(node, fls(valid), f->irq_start, 0,
&fpga_irqdomain_ops, f);
pr_info("FPGA IRQ chip %d \"%s\" @ %p, %u irqs\n",
fpga_irq_id, name, base, f->used_irqs);
fpga_irq_id++;
}
|
