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 <asm/io.h>
  14 #include <asm/mach/irq.h>
  15 #include <asm/mach-types.h>
  16 #include <asm/arch-ns9xxx/regs-sys-common.h>
  17 #include <asm/arch-ns9xxx/irqs.h>
  18 #include <asm/arch-ns9xxx/board.h>
  19
  20 #include "generic.h"
  21
  22 static void ns9xxx_mask_irq(unsigned int irq)
  23 {
  24         /* XXX: better use cpp symbols */
  25         u32 ic = __raw_readl(SYS_IC(irq / 4));
  26         ic &= ~(1 << (7 + 8 * (3 - (irq & 3))));
  27         __raw_writel(ic, SYS_IC(irq / 4));
  28 }
  29
  30 static void ns9xxx_ack_irq(unsigned int irq)
  31 {
  32         __raw_writel(0, SYS_ISRADDR);
  33 }
  34
  35 static void ns9xxx_maskack_irq(unsigned int irq)
  36 {
  37         ns9xxx_mask_irq(irq);
  38         ns9xxx_ack_irq(irq);
  39 }
  40
  41 static void ns9xxx_unmask_irq(unsigned int irq)
  42 {
  43         /* XXX: better use cpp symbols */
  44         u32 ic = __raw_readl(SYS_IC(irq / 4));
  45         ic |= 1 << (7 + 8 * (3 - (irq & 3)));
  46         __raw_writel(ic, SYS_IC(irq / 4));
  47 }
  48
  49 static struct irq_chip ns9xxx_chip = {
  50         .ack            = ns9xxx_ack_irq,
  51         .mask           = ns9xxx_mask_irq,
  52         .mask_ack       = ns9xxx_maskack_irq,
  53         .unmask         = ns9xxx_unmask_irq,
  54 };
  55
  56 #if 0
  57 #define handle_irq handle_level_irq
  58 #else
  59 void handle_prio_irq(unsigned int irq, struct irq_desc *desc)
  60 {
  61         unsigned int cpu = smp_processor_id();
  62         struct irqaction *action;
  63         irqreturn_t action_ret;
  64
  65         spin_lock(&desc->lock);
  66
  67         if (unlikely(desc->status & IRQ_INPROGRESS))
  68                 goto out_unlock;
  69
  70         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
  71         kstat_cpu(cpu).irqs[irq]++;
  72
  73         action = desc->action;
  74         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
  75                 goto out_unlock;
  76
  77         desc->status |= IRQ_INPROGRESS;
  78         spin_unlock(&desc->lock);
  79
  80         action_ret = handle_IRQ_event(irq, action);
  81
  82         spin_lock(&desc->lock);
  83         desc->status &= ~IRQ_INPROGRESS;
  84         if (!(desc->status & IRQ_DISABLED) && desc->chip->ack)
  85                 desc->chip->ack(irq);
  86
  87 out_unlock:
  88         spin_unlock(&desc->lock);
  89 }
  90 #define handle_irq handle_prio_irq
  91 #endif
  92
  93 void __init ns9xxx_init_irq(void)
  94 {
  95         int i;
  96
  97         /* disable all IRQs */
  98         for (i = 0; i < 8; ++i)
  99                 __raw_writel((4 * i) << 24 | (4 * i + 1) << 16 |
 100                                 (4 * i + 2) << 8 | (4 * i + 3), SYS_IC(i));
 101
 102         /* simple interrupt prio table:
 103          * prio(x) < prio(y) <=> x < y
 104          */
 105         for (i = 0; i < 32; ++i)
 106                 __raw_writel(i, SYS_IVA(i));
 107
 108         for (i = 0; i <= 31; ++i) {
 109                 set_irq_chip(i, &ns9xxx_chip);
 110                 set_irq_handler(i, handle_irq);
 111                 set_irq_flags(i, IRQF_VALID);
 112         }
 113 }