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 /* simple interrupt prio table: prio(x) < prio(y) <=> x < y */
  23 #define irq2prio(i) (i)
  24 #define prio2irq(p) (p)
  25
  26 static void ns9xxx_mask_irq(unsigned int irq)
  27 {
  28         /* XXX: better use cpp symbols */
  29         int prio = irq2prio(irq);
  30         u32 ic = __raw_readl(SYS_IC(prio / 4));
  31         ic &= ~(1 << (7 + 8 * (3 - (prio & 3))));
  32         __raw_writel(ic, SYS_IC(prio / 4));
  33 }
  34
  35 static void ns9xxx_ack_irq(unsigned int irq)
  36 {
  37         __raw_writel(0, SYS_ISRADDR);
  38 }
  39
  40 static void ns9xxx_maskack_irq(unsigned int irq)
  41 {
  42         ns9xxx_mask_irq(irq);
  43         ns9xxx_ack_irq(irq);
  44 }
  45
  46 static void ns9xxx_unmask_irq(unsigned int irq)
  47 {
  48         /* XXX: better use cpp symbols */
  49         int prio = irq2prio(irq);
  50         u32 ic = __raw_readl(SYS_IC(prio / 4));
  51         ic |= 1 << (7 + 8 * (3 - (prio & 3)));
  52         __raw_writel(ic, SYS_IC(prio / 4));
  53 }
  54
  55 static struct irq_chip ns9xxx_chip = {
  56         .ack            = ns9xxx_ack_irq,
  57         .mask           = ns9xxx_mask_irq,
  58         .mask_ack       = ns9xxx_maskack_irq,
  59         .unmask         = ns9xxx_unmask_irq,
  60 };
  61
  62 #if 0
  63 #define handle_irq handle_level_irq
  64 #else
  65 void handle_prio_irq(unsigned int irq, struct irq_desc *desc)
  66 {
  67         unsigned int cpu = smp_processor_id();
  68         struct irqaction *action;
  69         irqreturn_t action_ret;
  70
  71         spin_lock(&desc->lock);
  72
  73         if (unlikely(desc->status & IRQ_INPROGRESS))
  74                 goto out_unlock;
  75
  76         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
  77         kstat_cpu(cpu).irqs[irq]++;
  78
  79         action = desc->action;
  80         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
  81                 goto out_unlock;
  82
  83         desc->status |= IRQ_INPROGRESS;
  84         spin_unlock(&desc->lock);
  85
  86         action_ret = handle_IRQ_event(irq, action);
  87
  88         spin_lock(&desc->lock);
  89         desc->status &= ~IRQ_INPROGRESS;
  90         if (!(desc->status & IRQ_DISABLED) && desc->chip->ack)
  91                 desc->chip->ack(irq);
  92
  93 out_unlock:
  94         spin_unlock(&desc->lock);
  95 }
  96 #define handle_irq handle_prio_irq
  97 #endif
  98
  99 void __init ns9xxx_init_irq(void)
 100 {
 101         int i;
 102
 103         /* disable all IRQs */
 104         for (i = 0; i < 8; ++i)
 105                 __raw_writel(prio2irq(4 * i) << 24 |
 106                                 prio2irq(4 * i + 1) << 16 |
 107                                 prio2irq(4 * i + 2) << 8 |
 108                                 prio2irq(4 * i + 3),
 109                                 SYS_IC(i));
 110
 111         for (i = 0; i < 32; ++i)
 112                 __raw_writel(prio2irq(i), SYS_IVA(i));
 113
 114         for (i = 0; i <= 31; ++i) {
 115                 set_irq_chip(i, &ns9xxx_chip);
 116                 set_irq_handler(i, handle_irq);
 117                 set_irq_flags(i, IRQF_VALID);
 118         }
 119 }