platforms/86xx/pic.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Copyright 2008 Freescale Semiconductor, Inc.
0004  */
0005
0006 #include <linux/stddef.h>
0007 #include <linux/kernel.h>
0008 #include <linux/interrupt.h>
0009 #include <linux/of_irq.h>
0010 #include <linux/of_platform.h>
0011
0012 #include <asm/mpic.h>
0013 #include <asm/i8259.h>
0014
0015 #ifdef CONFIG_PPC_I8259
0016 static void mpc86xx_8259_cascade(struct irq_desc *desc)
0017 {
0018     struct irq_chip *chip = irq_desc_get_chip(desc);
0019     unsigned int cascade_irq = i8259_irq();
0020
0021     if (cascade_irq)
0022         generic_handle_irq(cascade_irq);
0023
0024     chip->irq_eoi(&desc->irq_data);
0025 }
0026 #endif  /* CONFIG_PPC_I8259 */
0027
0028 void __init mpc86xx_init_irq(void)
0029 {
0030 #ifdef CONFIG_PPC_I8259
0031     struct device_node *np;
0032     struct device_node *cascade_node = NULL;
0033     int cascade_irq;
0034 #endif
0035
0036     struct mpic *mpic = mpic_alloc(NULL, 0, MPIC_BIG_ENDIAN |
0037             MPIC_SINGLE_DEST_CPU,
0038             0, 256, " MPIC     ");
0039     BUG_ON(mpic == NULL);
0040
0041     mpic_init(mpic);
0042
0043 #ifdef CONFIG_PPC_I8259
0044     /* Initialize i8259 controller */
0045     for_each_node_by_type(np, "interrupt-controller")
0046         if (of_device_is_compatible(np, "chrp,iic")) {
0047             cascade_node = np;
0048             break;
0049         }
0050
0051     if (cascade_node == NULL) {
0052         printk(KERN_DEBUG "Could not find i8259 PIC\n");
0053         return;
0054     }
0055
0056     cascade_irq = irq_of_parse_and_map(cascade_node, 0);
0057     if (!cascade_irq) {
0058         printk(KERN_ERR "Failed to map cascade interrupt\n");
0059         return;
0060     }
0061
0062     i8259_init(cascade_node, 0);
0063     of_node_put(cascade_node);
0064
0065     irq_set_chained_handler(cascade_irq, mpc86xx_8259_cascade);
0066 #endif
0067 }