1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright 2008 Freescale Semiconductor, Inc.
4 */
5
6#include <linux/stddef.h>
7#include <linux/kernel.h>
8#include <linux/interrupt.h>
9#include <linux/of.h>
10#include <linux/of_irq.h>
11
12#include <asm/mpic.h>
13#include <asm/i8259.h>
14
15#include "mpc86xx.h"
16
17#ifdef CONFIG_PPC_I8259
18static void mpc86xx_8259_cascade(struct irq_desc *desc)
19{
20 struct irq_chip *chip = irq_desc_get_chip(desc);
21 unsigned int cascade_irq = i8259_irq();
22
23 if (cascade_irq)
24 generic_handle_irq(cascade_irq);
25
26 chip->irq_eoi(&desc->irq_data);
27}
28#endif /* CONFIG_PPC_I8259 */
29
30void __init mpc86xx_init_irq(void)
31{
32#ifdef CONFIG_PPC_I8259
33 struct device_node *np;
34 struct device_node *cascade_node = NULL;
35 int cascade_irq;
36#endif
37
38 struct mpic *mpic = mpic_alloc(NULL, 0, MPIC_BIG_ENDIAN |
39 MPIC_SINGLE_DEST_CPU,
40 0, 256, " MPIC ");
41 BUG_ON(mpic == NULL);
42
43 mpic_init(mpic);
44
45#ifdef CONFIG_PPC_I8259
46 /* Initialize i8259 controller */
47 for_each_node_by_type(np, "interrupt-controller")
48 if (of_device_is_compatible(np, "chrp,iic")) {
49 cascade_node = np;
50 break;
51 }
52
53 if (cascade_node == NULL) {
54 printk(KERN_DEBUG "Could not find i8259 PIC\n");
55 return;
56 }
57
58 cascade_irq = irq_of_parse_and_map(cascade_node, 0);
59 if (!cascade_irq) {
60 printk(KERN_ERR "Failed to map cascade interrupt\n");
61 return;
62 }
63
64 i8259_init(cascade_node, 0);
65 of_node_put(cascade_node);
66
67 irq_set_chained_handler(cascade_irq, mpc86xx_8259_cascade);
68#endif
69}
70

source code of linux/arch/powerpc/platforms/86xx/pic.c