xref: /openbmc/linux/arch/powerpc/platforms/86xx/pic.c (revision 545e4006)
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_platform.h>
14 
15 #include <asm/system.h>
16 #include <asm/mpic.h>
17 #include <asm/i8259.h>
18 
19 #ifdef CONFIG_PPC_I8259
20 static void mpc86xx_8259_cascade(unsigned int irq, struct irq_desc *desc)
21 {
22 	unsigned int cascade_irq = i8259_irq();
23 	if (cascade_irq != NO_IRQ)
24 		generic_handle_irq(cascade_irq);
25 	desc->chip->eoi(irq);
26 }
27 #endif	/* CONFIG_PPC_I8259 */
28 
29 void __init mpc86xx_init_irq(void)
30 {
31 	struct mpic *mpic;
32 	struct device_node *np;
33 	struct resource res;
34 #ifdef CONFIG_PPC_I8259
35 	struct device_node *cascade_node = NULL;
36 	int cascade_irq;
37 #endif
38 
39 	/* Determine PIC address. */
40 	np = of_find_node_by_type(NULL, "open-pic");
41 	if (np == NULL)
42 		return;
43 	of_address_to_resource(np, 0, &res);
44 
45 	mpic = mpic_alloc(np, res.start,
46 			MPIC_PRIMARY | MPIC_WANTS_RESET |
47 			MPIC_BIG_ENDIAN | MPIC_BROKEN_FRR_NIRQS,
48 			0, 256, " MPIC     ");
49 	of_node_put(np);
50 	BUG_ON(mpic == NULL);
51 
52 	mpic_init(mpic);
53 
54 #ifdef CONFIG_PPC_I8259
55 	/* Initialize i8259 controller */
56 	for_each_node_by_type(np, "interrupt-controller")
57 		if (of_device_is_compatible(np, "chrp,iic")) {
58 			cascade_node = np;
59 			break;
60 		}
61 
62 	if (cascade_node == NULL) {
63 		printk(KERN_DEBUG "Could not find i8259 PIC\n");
64 		return;
65 	}
66 
67 	cascade_irq = irq_of_parse_and_map(cascade_node, 0);
68 	if (cascade_irq == NO_IRQ) {
69 		printk(KERN_ERR "Failed to map cascade interrupt\n");
70 		return;
71 	}
72 
73 	i8259_init(cascade_node, 0);
74 	of_node_put(cascade_node);
75 
76 	set_irq_chained_handler(cascade_irq, mpc86xx_8259_cascade);
77 #endif
78 }
79