arch/mips/ddb5xxx/ddb5477/irq_5477.c

   1 /*
   2  * Copyright 2001 MontaVista Software Inc.
   3  * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
   4  *
   5  *  arch/mips/ddb5xxx/ddb5477/irq_5477.c
   6  *     This file defines the irq handler for Vrc5477.
   7  *
   8  * This program is free software; you can redistribute  it and/or modify it
   9  * under  the terms of  the GNU General  Public License as published by the
  10  * Free Software Foundation;  either version 2 of the  License, or (at your
  11  * option) any later version.
  12  *
  13  */
  14
  15 /*
  16  * Vrc5477 defines 32 IRQs.
  17  *
  18  * This file exports one function:
  19  *      vrc5477_irq_init(u32 irq_base);
  20  */
  21
  22 #include <linux/interrupt.h>
  23 #include <linux/types.h>
  24 #include <linux/ptrace.h>
  25
  26 #include <asm/debug.h>
  27
  28 #include <asm/ddb5xxx/ddb5xxx.h>
  29
  30 /* number of total irqs supported by Vrc5477 */
  31 #define NUM_5477_IRQ            32
  32
  33 static int vrc5477_irq_base = -1;
  34
  35
  36 static void
  37 vrc5477_irq_enable(unsigned int irq)
  38 {
  39         db_assert(vrc5477_irq_base != -1);
  40         db_assert(irq >= vrc5477_irq_base);
  41         db_assert(irq < vrc5477_irq_base+ NUM_5477_IRQ);
  42
  43         ll_vrc5477_irq_enable(irq - vrc5477_irq_base);
  44 }
  45
  46 static void
  47 vrc5477_irq_disable(unsigned int irq)
  48 {
  49         db_assert(vrc5477_irq_base != -1);
  50         db_assert(irq >= vrc5477_irq_base);
  51         db_assert(irq < vrc5477_irq_base + NUM_5477_IRQ);
  52
  53         ll_vrc5477_irq_disable(irq - vrc5477_irq_base);
  54 }
  55
  56 static unsigned int vrc5477_irq_startup(unsigned int irq)
  57 {
  58         vrc5477_irq_enable(irq);
  59         return 0;
  60 }
  61
  62 #define vrc5477_irq_shutdown    vrc5477_irq_disable
  63
  64 static void
  65 vrc5477_irq_ack(unsigned int irq)
  66 {
  67         db_assert(vrc5477_irq_base != -1);
  68         db_assert(irq >= vrc5477_irq_base);
  69         db_assert(irq < vrc5477_irq_base+ NUM_5477_IRQ);
  70
  71         /* clear the interrupt bit */
  72         /* some irqs require the driver to clear the sources */
  73         ddb_out32(DDB_INTCLR32, 1 << (irq - vrc5477_irq_base));
  74
  75         /* disable interrupt - some handler will re-enable the irq
  76          * and if the interrupt is leveled, we will have infinite loop
  77          */
  78         ll_vrc5477_irq_disable(irq - vrc5477_irq_base);
  79 }
  80
  81 static void
  82 vrc5477_irq_end(unsigned int irq)
  83 {
  84         db_assert(vrc5477_irq_base != -1);
  85         db_assert(irq >= vrc5477_irq_base);
  86         db_assert(irq < vrc5477_irq_base + NUM_5477_IRQ);
  87
  88         if(!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
  89                 ll_vrc5477_irq_enable( irq - vrc5477_irq_base);
  90 }
  91
  92 hw_irq_controller vrc5477_irq_controller = {
  93         .typename = "vrc5477_irq",
  94         .startup = vrc5477_irq_startup,
  95         .shutdown = vrc5477_irq_shutdown,
  96         .enable = vrc5477_irq_enable,
  97         .disable = vrc5477_irq_disable,
  98         .ack = vrc5477_irq_ack,
  99         .end = vrc5477_irq_end
 100 };
 101
 102 void __init vrc5477_irq_init(u32 irq_base)
 103 {
 104         u32 i;
 105
 106         for (i= irq_base; i< irq_base+ NUM_5477_IRQ; i++) {
 107                 irq_desc[i].status = IRQ_DISABLED;
 108                 irq_desc[i].action = NULL;
 109                 irq_desc[i].depth = 1;
 110                 irq_desc[i].handler = &vrc5477_irq_controller;
 111         }
 112
 113         vrc5477_irq_base = irq_base;
 114 }
 115
 116 void ll_vrc5477_irq_route(int vrc5477_irq, int ip)
 117 {
 118         u32 reg_value;
 119         u32 reg_bitmask;
 120         u32 reg_index;
 121
 122         db_assert(vrc5477_irq >= 0);
 123         db_assert(vrc5477_irq < NUM_5477_IRQ);
 124         db_assert(ip >= 0);
 125         db_assert((ip < 5) || (ip == 6));
 126
 127         reg_index = DDB_INTCTRL0 + vrc5477_irq/8*4;
 128         reg_value = ddb_in32(reg_index);
 129         reg_bitmask = 7 << (vrc5477_irq % 8 * 4);
 130         reg_value &= ~reg_bitmask;
 131         reg_value |= ip << (vrc5477_irq % 8 * 4);
 132         ddb_out32(reg_index, reg_value);
 133 }
 134
 135 void ll_vrc5477_irq_enable(int vrc5477_irq)
 136 {
 137         u32 reg_value;
 138         u32 reg_bitmask;
 139         u32 reg_index;
 140
 141         db_assert(vrc5477_irq >= 0);
 142         db_assert(vrc5477_irq < NUM_5477_IRQ);
 143
 144         reg_index = DDB_INTCTRL0 + vrc5477_irq/8*4;
 145         reg_value = ddb_in32(reg_index);
 146         reg_bitmask = 8 << (vrc5477_irq % 8 * 4);
 147         db_assert((reg_value & reg_bitmask) == 0);
 148         ddb_out32(reg_index, reg_value | reg_bitmask);
 149 }
 150
 151 void ll_vrc5477_irq_disable(int vrc5477_irq)
 152 {
 153         u32 reg_value;
 154         u32 reg_bitmask;
 155         u32 reg_index;
 156
 157         db_assert(vrc5477_irq >= 0);
 158         db_assert(vrc5477_irq < NUM_5477_IRQ);
 159
 160         reg_index = DDB_INTCTRL0 + vrc5477_irq/8*4;
 161         reg_value = ddb_in32(reg_index);
 162         reg_bitmask = 8 << (vrc5477_irq % 8 * 4);
 163
 164         /* we assert that the interrupt is enabled (perhaps over-zealous) */
 165         db_assert( (reg_value & reg_bitmask) != 0);
 166         ddb_out32(reg_index, reg_value & ~reg_bitmask);
 167 }