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/mach/irq.h>
  13 #include <asm/mach-types.h>
  14 #include <asm/arch-ns9xxx/regs-sys.h>
  15 #include <asm/arch-ns9xxx/irqs.h>
  16 #include <asm/arch-ns9xxx/board.h>
  17
  18 #include "generic.h"
  19
  20 static void ns9xxx_ack_irq_timer(unsigned int irq)
  21 {
  22         u32 tc = SYS_TC(irq - IRQ_TIMER0);
  23
  24         REGSET(tc, SYS_TCx, INTC, SET);
  25         SYS_TC(irq - IRQ_TIMER0) = tc;
  26
  27         REGSET(tc, SYS_TCx, INTC, UNSET);
  28         SYS_TC(irq - IRQ_TIMER0) = tc;
  29 }
  30
  31 void (*ns9xxx_ack_irq_functions[NR_IRQS])(unsigned int) = {
  32         [IRQ_TIMER0] = ns9xxx_ack_irq_timer,
  33         [IRQ_TIMER1] = ns9xxx_ack_irq_timer,
  34         [IRQ_TIMER2] = ns9xxx_ack_irq_timer,
  35         [IRQ_TIMER3] = ns9xxx_ack_irq_timer,
  36 };
  37
  38 static void ns9xxx_mask_irq(unsigned int irq)
  39 {
  40         /* XXX: better use cpp symbols */
  41         SYS_IC(irq / 4) &= ~(1 << (7 + 8 * (3 - (irq & 3))));
  42 }
  43
  44 static void ns9xxx_ack_irq(unsigned int irq)
  45 {
  46         if (!ns9xxx_ack_irq_functions[irq]) {
  47                 printk(KERN_ERR "no ack function for irq %u\n", irq);
  48                 BUG();
  49         }
  50
  51         ns9xxx_ack_irq_functions[irq](irq);
  52         SYS_ISRADDR = 0;
  53 }
  54
  55 static void ns9xxx_maskack_irq(unsigned int irq)
  56 {
  57         ns9xxx_mask_irq(irq);
  58         ns9xxx_ack_irq(irq);
  59 }
  60
  61 static void ns9xxx_unmask_irq(unsigned int irq)
  62 {
  63         /* XXX: better use cpp symbols */
  64         SYS_IC(irq / 4) |= 1 << (7 + 8 * (3 - (irq & 3)));
  65 }
  66
  67 static struct irq_chip ns9xxx_chip = {
  68         .ack            = ns9xxx_ack_irq,
  69         .mask           = ns9xxx_mask_irq,
  70         .mask_ack       = ns9xxx_maskack_irq,
  71         .unmask         = ns9xxx_unmask_irq,
  72 };
  73
  74 void __init ns9xxx_init_irq(void)
  75 {
  76         int i;
  77
  78         /* disable all IRQs */
  79         for (i = 0; i < 8; ++i)
  80                 SYS_IC(i) = (4 * i) << 24 | (4 * i + 1) << 16 |
  81                         (4 * i + 2) << 8 | (4 * i + 3);
  82
  83         /* simple interrupt prio table:
  84          * prio(x) < prio(y) <=> x < y
  85          */
  86         for (i = 0; i < 32; ++i)
  87                 SYS_IVA(i) = i;
  88
  89         for (i = IRQ_WATCHDOG; i <= IRQ_EXT3; ++i) {
  90                 set_irq_chip(i, &ns9xxx_chip);
  91                 set_irq_handler(i, handle_level_irq);
  92                 set_irq_flags(i, IRQF_VALID);
  93         }
  94 }