arch/arm/mach-ns9xxx/irq.c

   1 /*
   2  * arch/arm/mach-ns9xxx/irq.c
   3  *
   4  * Copyright (C) 2006,2007 by Digi International Inc.
   5  * All rights reserved.
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published by
   9  * the Free Software Foundation.
  10  */
  11 #include <linux/interrupt.h>
  12 #include <asm/io.h>
  13 #include <asm/mach/irq.h>
  14 #include <asm/mach-types.h>
  15 #include <asm/arch-ns9xxx/regs-sys-common.h>
  16 #include <asm/arch-ns9xxx/irqs.h>
  17 #include <asm/arch-ns9xxx/board.h>
  18
  19 #include "generic.h"
  20
  21 static void ns9xxx_mask_irq(unsigned int irq)
  22 {
  23         /* XXX: better use cpp symbols */
  24         u32 ic = __raw_readl(SYS_IC(irq / 4));
  25         ic &= ~(1 << (7 + 8 * (3 - (irq & 3))));
  26         __raw_writel(ic, SYS_IC(irq / 4));
  27 }
  28
  29 static void ns9xxx_ack_irq(unsigned int irq)
  30 {
  31         __raw_writel(0, SYS_ISRADDR);
  32 }
  33
  34 static void ns9xxx_maskack_irq(unsigned int irq)
  35 {
  36         ns9xxx_mask_irq(irq);
  37         ns9xxx_ack_irq(irq);
  38 }
  39
  40 static void ns9xxx_unmask_irq(unsigned int irq)
  41 {
  42         /* XXX: better use cpp symbols */
  43         u32 ic = __raw_readl(SYS_IC(irq / 4));
  44         ic |= 1 << (7 + 8 * (3 - (irq & 3)));
  45         __raw_writel(ic, SYS_IC(irq / 4));
  46 }
  47
  48 static struct irq_chip ns9xxx_chip = {
  49         .ack            = ns9xxx_ack_irq,
  50         .mask           = ns9xxx_mask_irq,
  51         .mask_ack       = ns9xxx_maskack_irq,
  52         .unmask         = ns9xxx_unmask_irq,
  53 };
  54
  55 void __init ns9xxx_init_irq(void)
  56 {
  57         int i;
  58
  59         /* disable all IRQs */
  60         for (i = 0; i < 8; ++i)
  61                 __raw_writel((4 * i) << 24 | (4 * i + 1) << 16 |
  62                                 (4 * i + 2) << 8 | (4 * i + 3), SYS_IC(i));
  63
  64         /* simple interrupt prio table:
  65          * prio(x) < prio(y) <=> x < y
  66          */
  67         for (i = 0; i < 32; ++i)
  68                 __raw_writel(i, SYS_IVA(i));
  69
  70         for (i = 0; i <= 31; ++i) {
  71                 set_irq_chip(i, &ns9xxx_chip);
  72                 set_irq_handler(i, handle_level_irq);
  73                 set_irq_flags(i, IRQF_VALID);
  74         }
  75 }