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/system.h>
  16 #include <asm/mpic.h>
  17 #include <asm/i8259.h>
  18
  19 #ifdef CONFIG_PPC_I8259
  20 static void mpc86xx_8259_cascade(unsigned int irq, struct irq_desc *desc)
  21 {
  22         struct irq_chip *chip = irq_desc_get_chip(desc);
  23         unsigned int cascade_irq = i8259_irq();
  24
  25         if (cascade_irq != NO_IRQ)
  26                 generic_handle_irq(cascade_irq);
  27
  28         chip->irq_eoi(&desc->irq_data);
  29 }
  30 #endif  /* CONFIG_PPC_I8259 */
  31
  32 void __init mpc86xx_init_irq(void)
  33 {
  34 #ifdef CONFIG_PPC_I8259
  35         struct device_node *np;
  36         struct device_node *cascade_node = NULL;
  37         int cascade_irq;
  38 #endif
  39
  40         struct mpic *mpic = mpic_alloc(NULL, 0,
  41                         MPIC_WANTS_RESET | MPIC_BIG_ENDIAN |
  42                         MPIC_BROKEN_FRR_NIRQS | MPIC_SINGLE_DEST_CPU,
  43                         0, 256, " MPIC     ");
  44         BUG_ON(mpic == NULL);
  45
  46         mpic_init(mpic);
  47
  48 #ifdef CONFIG_PPC_I8259
  49         /* Initialize i8259 controller */
  50         for_each_node_by_type(np, "interrupt-controller")
  51                 if (of_device_is_compatible(np, "chrp,iic")) {
  52                         cascade_node = np;
  53                         break;
  54                 }
  55
  56         if (cascade_node == NULL) {
  57                 printk(KERN_DEBUG "Could not find i8259 PIC\n");
  58                 return;
  59         }
  60
  61         cascade_irq = irq_of_parse_and_map(cascade_node, 0);
  62         if (cascade_irq == NO_IRQ) {
  63                 printk(KERN_ERR "Failed to map cascade interrupt\n");
  64                 return;
  65         }
  66
  67         i8259_init(cascade_node, 0);
  68         of_node_put(cascade_node);
  69
  70         irq_set_chained_handler(cascade_irq, mpc86xx_8259_cascade);
  71 #endif
  72 }