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

   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/mpic.h>
  16 #include <asm/i8259.h>
  17
  18 #ifdef CONFIG_PPC_I8259
  19 static void mpc86xx_8259_cascade(unsigned int irq, struct irq_desc *desc)
  20 {
  21         struct irq_chip *chip = irq_desc_get_chip(desc);
  22         unsigned int cascade_irq = i8259_irq();
  23
  24         if (cascade_irq != NO_IRQ)
  25                 generic_handle_irq(cascade_irq);
  26
  27         chip->irq_eoi(&desc->irq_data);
  28 }
  29 #endif  /* CONFIG_PPC_I8259 */
  30
  31 void __init mpc86xx_init_irq(void)
  32 {
  33 #ifdef CONFIG_PPC_I8259
  34         struct device_node *np;
  35         struct device_node *cascade_node = NULL;
  36         int cascade_irq;
  37 #endif
  38
  39         struct mpic *mpic = mpic_alloc(NULL, 0, MPIC_BIG_ENDIAN |
  40                         MPIC_SINGLE_DEST_CPU,
  41                         0, 256, " MPIC     ");
  42         BUG_ON(mpic == NULL);
  43
  44         mpic_init(mpic);
  45
  46 #ifdef CONFIG_PPC_I8259
  47         /* Initialize i8259 controller */
  48         for_each_node_by_type(np, "interrupt-controller")
  49                 if (of_device_is_compatible(np, "chrp,iic")) {
  50                         cascade_node = np;
  51                         break;
  52                 }
  53
  54         if (cascade_node == NULL) {
  55                 printk(KERN_DEBUG "Could not find i8259 PIC\n");
  56                 return;
  57         }
  58
  59         cascade_irq = irq_of_parse_and_map(cascade_node, 0);
  60         if (cascade_irq == NO_IRQ) {
  61                 printk(KERN_ERR "Failed to map cascade interrupt\n");
  62                 return;
  63         }
  64
  65         i8259_init(cascade_node, 0);
  66         of_node_put(cascade_node);
  67
  68         irq_set_chained_handler(cascade_irq, mpc86xx_8259_cascade);
  69 #endif
  70 }