arch/powerpc/platforms/86xx/pic.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright 2008 Freescale Semiconductor, Inc.
   4  */
   5
   6 #include <linux/stddef.h>
   7 #include <linux/kernel.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/of_irq.h>
  10 #include <linux/of_platform.h>
  11
  12 #include <asm/mpic.h>
  13 #include <asm/i8259.h>
  14
  15 #ifdef CONFIG_PPC_I8259
  16 static void mpc86xx_8259_cascade(struct irq_desc *desc)
  17 {
  18         struct irq_chip *chip = irq_desc_get_chip(desc);
  19         unsigned int cascade_irq = i8259_irq();
  20
  21         if (cascade_irq)
  22                 generic_handle_irq(cascade_irq);
  23
  24         chip->irq_eoi(&desc->irq_data);
  25 }
  26 #endif  /* CONFIG_PPC_I8259 */
  27
  28 void __init mpc86xx_init_irq(void)
  29 {
  30 #ifdef CONFIG_PPC_I8259
  31         struct device_node *np;
  32         struct device_node *cascade_node = NULL;
  33         int cascade_irq;
  34 #endif
  35
  36         struct mpic *mpic = mpic_alloc(NULL, 0, MPIC_BIG_ENDIAN |
  37                         MPIC_SINGLE_DEST_CPU,
  38                         0, 256, " MPIC     ");
  39         BUG_ON(mpic == NULL);
  40
  41         mpic_init(mpic);
  42
  43 #ifdef CONFIG_PPC_I8259
  44         /* Initialize i8259 controller */
  45         for_each_node_by_type(np, "interrupt-controller")
  46                 if (of_device_is_compatible(np, "chrp,iic")) {
  47                         cascade_node = np;
  48                         break;
  49                 }
  50
  51         if (cascade_node == NULL) {
  52                 printk(KERN_DEBUG "Could not find i8259 PIC\n");
  53                 return;
  54         }
  55
  56         cascade_irq = irq_of_parse_and_map(cascade_node, 0);
  57         if (!cascade_irq) {
  58                 printk(KERN_ERR "Failed to map cascade interrupt\n");
  59                 return;
  60         }
  61
  62         i8259_init(cascade_node, 0);
  63         of_node_put(cascade_node);
  64
  65         irq_set_chained_handler(cascade_irq, mpc86xx_8259_cascade);
  66 #endif
  67 }