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 <linux/kernel_stat.h>
  13 #include <linux/io.h>
  14 #include <asm/mach/irq.h>
  15 #include <mach/regs-sys-common.h>
  16 #include <mach/irqs.h>
  17 #include <mach/board.h>
  18
  19 #include "generic.h"
  20
  21 /* simple interrupt prio table: prio(x) < prio(y) <=> x < y */
  22 #define irq2prio(i) (i)
  23 #define prio2irq(p) (p)
  24
  25 static void ns9xxx_mask_irq(struct irq_data *d)
  26 {
  27         /* XXX: better use cpp symbols */
  28         int prio = irq2prio(d->irq);
  29         u32 ic = __raw_readl(SYS_IC(prio / 4));
  30         ic &= ~(1 << (7 + 8 * (3 - (prio & 3))));
  31         __raw_writel(ic, SYS_IC(prio / 4));
  32 }
  33
  34 static void ns9xxx_eoi_irq(struct irq_data *d)
  35 {
  36         __raw_writel(0, SYS_ISRADDR);
  37 }
  38
  39 static void ns9xxx_unmask_irq(struct irq_data *d)
  40 {
  41         /* XXX: better use cpp symbols */
  42         int prio = irq2prio(d->irq);
  43         u32 ic = __raw_readl(SYS_IC(prio / 4));
  44         ic |= 1 << (7 + 8 * (3 - (prio & 3)));
  45         __raw_writel(ic, SYS_IC(prio / 4));
  46 }
  47
  48 static struct irq_chip ns9xxx_chip = {
  49         .irq_eoi        = ns9xxx_eoi_irq,
  50         .irq_mask       = ns9xxx_mask_irq,
  51         .irq_unmask     = ns9xxx_unmask_irq,
  52 };
  53
  54 void __init ns9xxx_init_irq(void)
  55 {
  56         int i;
  57
  58         /* disable all IRQs */
  59         for (i = 0; i < 8; ++i)
  60                 __raw_writel(prio2irq(4 * i) << 24 |
  61                                 prio2irq(4 * i + 1) << 16 |
  62                                 prio2irq(4 * i + 2) << 8 |
  63                                 prio2irq(4 * i + 3),
  64                                 SYS_IC(i));
  65
  66         for (i = 0; i < 32; ++i)
  67                 __raw_writel(prio2irq(i), SYS_IVA(i));
  68
  69         for (i = 0; i <= 31; ++i) {
  70                 irq_set_chip_and_handler(i, &ns9xxx_chip, handle_fasteoi_irq);
  71                 set_irq_flags(i, IRQF_VALID);
  72                 irq_set_status_flags(i, IRQ_LEVEL);
  73         }
  74 }