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