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
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
|
// SPDX-License-Identifier: GPL-2.0
/*
* Support for Versatile FPGA-based IRQ controllers
*/
#include <linux/bitops.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/irqchip.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/irqchip/versatile-fpga.h>
#include <linux/irqdomain.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <asm/exception.h>
#include <asm/mach/irq.h>
#define IRQ_STATUS 0x00
#define IRQ_RAW_STATUS 0x04
#define IRQ_ENABLE_SET 0x08
#define IRQ_ENABLE_CLEAR 0x0c
#define INT_SOFT_SET 0x10
#define INT_SOFT_CLEAR 0x14
#define FIQ_STATUS 0x20
#define FIQ_RAW_STATUS 0x24
#define FIQ_ENABLE 0x28
#define FIQ_ENABLE_SET 0x28
#define FIQ_ENABLE_CLEAR 0x2C
#define PIC_ENABLES 0x20 /* set interrupt pass through bits */
/**
* struct fpga_irq_data - irq data container for the FPGA IRQ controller
* @base: memory offset in virtual memory
* @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;
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_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(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
struct fpga_irq_data *f = irq_desc_get_handler_data(desc);
u32 status;
chained_irq_enter(chip, desc);
status = readl(f->base + IRQ_STATUS);
if (status == 0) {
do_bad_IRQ(desc);
goto out;
}
do {
unsigned int irq = ffs(status) - 1;
status &= ~(1 << irq);
generic_handle_irq(irq_find_mapping(f->domain, irq));
} while (status);
out:
chained_irq_exit(chip, desc);
}
/*
* 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_domain_irq(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 & BIT(hwirq)))
return -EPERM;
irq_set_chip_data(irq, f);
irq_set_chip_and_handler(irq, &f->chip,
handle_level_irq);
irq_set_probe(irq);
return 0;
}
static const 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;
int i;
if (fpga_irq_id >= ARRAY_SIZE(fpga_irq_devices)) {
pr_err("%s: too few FPGA IRQ controllers, increase CONFIG_VERSATILE_FPGA_IRQ_NR\n", __func__);
return;
}
f = &fpga_irq_devices[fpga_irq_id];
f->base = base;
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_chained_handler_and_data(parent_irq, fpga_irq_handle,
f);
}
/* This will also allocate irq descriptors */
f->domain = irq_domain_add_simple(node, fls(valid), irq_start,
&fpga_irqdomain_ops, f);
/* This will allocate all valid descriptors in the linear case */
for (i = 0; i < fls(valid); i++)
if (valid & BIT(i)) {
if (!irq_start)
irq_create_mapping(f->domain, i);
f->used_irqs++;
}
pr_info("FPGA IRQ chip %d \"%s\" @ %p, %u irqs",
fpga_irq_id, name, base, f->used_irqs);
if (parent_irq != -1)
pr_cont(", parent IRQ: %d\n", parent_irq);
else
pr_cont("\n");
fpga_irq_id++;
}
#ifdef CONFIG_OF
int __init fpga_irq_of_init(struct device_node *node,
struct device_node *parent)
{
void __iomem *base;
u32 clear_mask;
u32 valid_mask;
int parent_irq;
if (WARN_ON(!node))
return -ENODEV;
base = of_iomap(node, 0);
WARN(!base, "unable to map fpga irq registers\n");
if (of_property_read_u32(node, "clear-mask", &clear_mask))
clear_mask = 0;
if (of_property_read_u32(node, "valid-mask", &valid_mask))
valid_mask = 0;
writel(clear_mask, base + IRQ_ENABLE_CLEAR);
writel(clear_mask, base + FIQ_ENABLE_CLEAR);
/* Some chips are cascaded from a parent IRQ */
parent_irq = irq_of_parse_and_map(node, 0);
if (!parent_irq) {
set_handle_irq(fpga_handle_irq);
parent_irq = -1;
}
fpga_irq_init(base, node->name, 0, parent_irq, valid_mask, node);
/*
* On Versatile AB/PB, some secondary interrupts have a direct
* pass-thru to the primary controller for IRQs 20 and 22-31 which need
* to be enabled. See section 3.10 of the Versatile AB user guide.
*/
if (of_device_is_compatible(node, "arm,versatile-sic"))
writel(0xffd00000, base + PIC_ENABLES);
return 0;
}
IRQCHIP_DECLARE(arm_fpga, "arm,versatile-fpga-irq", fpga_irq_of_init);
IRQCHIP_DECLARE(arm_fpga_sic, "arm,versatile-sic", fpga_irq_of_init);
IRQCHIP_DECLARE(ox810se_rps, "oxsemi,ox810se-rps-irq", fpga_irq_of_init);
#endif
|
