xref: /openbmc/linux/arch/powerpc/platforms/86xx/pic.c (revision 90a53e44)
1 /*
2  * Copyright 2008 Freescale Semiconductor, Inc.
3  *
4  * This program is free software; you can redistribute  it and/or modify it
5  * under  the terms of  the GNU General  Public License as published by the
6  * Free Software Foundation;  either version 2 of the  License, or (at your
7  * option) any later version.
8  */
9 
10 #include <linux/stddef.h>
11 #include <linux/kernel.h>
12 #include <linux/interrupt.h>
13 #include <linux/of_irq.h>
14 #include <linux/of_platform.h>
15 
16 #include <asm/mpic.h>
17 #include <asm/i8259.h>
18 
19 #ifdef CONFIG_PPC_I8259
20 static void mpc86xx_8259_cascade(struct irq_desc *desc)
21 {
22 	struct irq_chip *chip = irq_desc_get_chip(desc);
23 	unsigned int cascade_irq = i8259_irq();
24 
25 	if (cascade_irq)
26 		generic_handle_irq(cascade_irq);
27 
28 	chip->irq_eoi(&desc->irq_data);
29 }
30 #endif	/* CONFIG_PPC_I8259 */
31 
32 void __init mpc86xx_init_irq(void)
33 {
34 #ifdef CONFIG_PPC_I8259
35 	struct device_node *np;
36 	struct device_node *cascade_node = NULL;
37 	int cascade_irq;
38 #endif
39 
40 	struct mpic *mpic = mpic_alloc(NULL, 0, MPIC_BIG_ENDIAN |
41 			MPIC_SINGLE_DEST_CPU,
42 			0, 256, " MPIC     ");
43 	BUG_ON(mpic == NULL);
44 
45 	mpic_init(mpic);
46 
47 #ifdef CONFIG_PPC_I8259
48 	/* Initialize i8259 controller */
49 	for_each_node_by_type(np, "interrupt-controller")
50 		if (of_device_is_compatible(np, "chrp,iic")) {
51 			cascade_node = np;
52 			break;
53 		}
54 
55 	if (cascade_node == NULL) {
56 		printk(KERN_DEBUG "Could not find i8259 PIC\n");
57 		return;
58 	}
59 
60 	cascade_irq = irq_of_parse_and_map(cascade_node, 0);
61 	if (!cascade_irq) {
62 		printk(KERN_ERR "Failed to map cascade interrupt\n");
63 		return;
64 	}
65 
66 	i8259_init(cascade_node, 0);
67 	of_node_put(cascade_node);
68 
69 	irq_set_chained_handler(cascade_irq, mpc86xx_8259_cascade);
70 #endif
71 }
72