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
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