1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * MPC85xx 8259 functions for DS Board Setup
4  *
5  * Author Xianghua Xiao (x.xiao@freescale.com)
6  * Roy Zang <tie-fei.zang@freescale.com>
7  *      - Add PCI/PCI Express support
8  * Copyright 2007 Freescale Semiconductor Inc.
9  */
10 
11 #include <linux/stddef.h>
12 #include <linux/kernel.h>
13 #include <linux/interrupt.h>
14 #include <linux/of_irq.h>
15 #include <linux/of_platform.h>
16 
17 #include <asm/mpic.h>
18 #include <asm/i8259.h>
19 
20 #include "mpc85xx.h"
21 
22 static void mpc85xx_8259_cascade(struct irq_desc *desc)
23 {
24 	struct irq_chip *chip = irq_desc_get_chip(desc);
25 	unsigned int cascade_irq = i8259_irq();
26 
27 	if (cascade_irq)
28 		generic_handle_irq(cascade_irq);
29 
30 	chip->irq_eoi(&desc->irq_data);
31 }
32 
33 void __init mpc85xx_8259_init(void)
34 {
35 	struct device_node *np;
36 	struct device_node *cascade_node = NULL;
37 	int cascade_irq;
38 
39 	/* Initialize the i8259 controller */
40 	for_each_node_by_type(np, "interrupt-controller") {
41 		if (of_device_is_compatible(np, "chrp,iic")) {
42 			cascade_node = np;
43 			break;
44 		}
45 	}
46 
47 	if (cascade_node == NULL) {
48 		pr_debug("i8259: Could not find i8259 PIC\n");
49 		return;
50 	}
51 
52 	cascade_irq = irq_of_parse_and_map(cascade_node, 0);
53 	if (!cascade_irq) {
54 		pr_err("i8259: Failed to map cascade interrupt\n");
55 		return;
56 	}
57 
58 	pr_debug("i8259: cascade mapped to irq %d\n", cascade_irq);
59 
60 	i8259_init(cascade_node, 0);
61 	of_node_put(cascade_node);
62 
63 	irq_set_chained_handler(cascade_irq, mpc85xx_8259_cascade);
64 }
65