1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2013 Altera Corporation
4 * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
5 * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
6 *
7 * based on irq.c from m68k which is:
8 *
9 * Copyright (C) 2007 Greg Ungerer <gerg@snapgear.com>
10 */
11
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/irqdomain.h>
15 #include <linux/of.h>
16
17 static u32 ienable;
18
19 asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs)
20 {
21 struct pt_regs *oldregs = set_irq_regs(regs);
22
23 irq_enter();
24 generic_handle_domain_irq(NULL, hwirq);
25 irq_exit();
26
27 set_irq_regs(oldregs);
28 }
29
30 static void chip_unmask(struct irq_data *d)
31 {
32 ienable |= (1 << d->hwirq);
33 WRCTL(CTL_IENABLE, ienable);
34 }
35
36 static void chip_mask(struct irq_data *d)
37 {
38 ienable &= ~(1 << d->hwirq);
39 WRCTL(CTL_IENABLE, ienable);
40 }
41
42 static struct irq_chip m_irq_chip = {
43 .name = "NIOS2-INTC",
44 .irq_unmask = chip_unmask,
45 .irq_mask = chip_mask,
46 };
47
48 static int irq_map(struct irq_domain *h, unsigned int virq,
49 irq_hw_number_t hw_irq_num)
50 {
51 irq_set_chip_and_handler(virq, &m_irq_chip, handle_level_irq);
52
53 return 0;
54 }
55
56 static const struct irq_domain_ops irq_ops = {
57 .map = irq_map,
58 .xlate = irq_domain_xlate_onecell,
59 };
60
61 void __init init_IRQ(void)
62 {
63 struct irq_domain *domain;
64 struct device_node *node;
65
66 node = of_find_compatible_node(NULL, NULL, "altr,nios2-1.0");
67 if (!node)
68 node = of_find_compatible_node(NULL, NULL, "altr,nios2-1.1");
69
70 BUG_ON(!node);
71
72 domain = irq_domain_add_linear(node, NIOS2_CPU_NR_IRQS, &irq_ops, NULL);
73 BUG_ON(!domain);
74
75 irq_set_default_host(domain);
76 of_node_put(node);
77 /* Load the initial ienable value */
78 ienable = RDCTL(CTL_IENABLE);
79 }
80
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