arch/arm/mach-iop3xx/iop331-irq.c

   1 /*
   2  * linux/arch/arm/mach-iop3xx/iop331-irq.c
   3  *
   4  * Generic IOP331 IRQ handling functionality
   5  *
   6  * Author: Dave Jiang <dave.jiang@intel.com>
   7  * Copyright (C) 2003 Intel Corp.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  *
  14  */
  15 #include <linux/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/list.h>
  18
  19 #include <asm/mach/irq.h>
  20 #include <asm/irq.h>
  21 #include <asm/hardware.h>
  22
  23 #include <asm/mach-types.h>
  24
  25 static u32 iop331_mask0 = 0;
  26 static u32 iop331_mask1 = 0;
  27
  28 static inline void intctl_write0(u32 val)
  29 {
  30     // INTCTL0
  31         asm volatile("mcr p6,0,%0,c0,c0,0"::"r" (val));
  32 }
  33
  34 static inline void intctl_write1(u32 val)
  35 {
  36     // INTCTL1
  37     asm volatile("mcr p6,0,%0,c1,c0,0"::"r" (val));
  38 }
  39
  40 static inline void intstr_write0(u32 val)
  41 {
  42     // INTSTR0
  43         asm volatile("mcr p6,0,%0,c2,c0,0"::"r" (val));
  44 }
  45
  46 static inline void intstr_write1(u32 val)
  47 {
  48     // INTSTR1
  49         asm volatile("mcr p6,0,%0,c3,c0,0"::"r" (val));
  50 }
  51
  52 static void
  53 iop331_irq_mask1 (unsigned int irq)
  54 {
  55         iop331_mask0 &= ~(1 << (irq - IOP331_IRQ_OFS));
  56         intctl_write0(iop331_mask0);
  57 }
  58
  59 static void
  60 iop331_irq_mask2 (unsigned int irq)
  61 {
  62         iop331_mask1 &= ~(1 << (irq - IOP331_IRQ_OFS - 32));
  63         intctl_write1(iop331_mask1);
  64 }
  65
  66 static void
  67 iop331_irq_unmask1(unsigned int irq)
  68 {
  69         iop331_mask0 |= (1 << (irq - IOP331_IRQ_OFS));
  70         intctl_write0(iop331_mask0);
  71 }
  72
  73 static void
  74 iop331_irq_unmask2(unsigned int irq)
  75 {
  76         iop331_mask1 |= (1 << (irq - IOP331_IRQ_OFS - 32));
  77         intctl_write1(iop331_mask1);
  78 }
  79
  80 struct irqchip iop331_irqchip1 = {
  81         .ack    = iop331_irq_mask1,
  82         .mask   = iop331_irq_mask1,
  83         .unmask = iop331_irq_unmask1,
  84 };
  85
  86 struct irqchip iop331_irqchip2 = {
  87         .ack    = iop331_irq_mask2,
  88         .mask   = iop331_irq_mask2,
  89         .unmask = iop331_irq_unmask2,
  90 };
  91
  92 void __init iop331_init_irq(void)
  93 {
  94         unsigned int i, tmp;
  95
  96         /* Enable access to coprocessor 6 for dealing with IRQs.
  97          * From RMK:
  98          * Basically, the Intel documentation here is poor.  It appears that
  99          * you need to set the bit to be able to access the coprocessor from
 100          * SVC mode.  Whether that allows access from user space or not is
 101          * unclear.
 102          */
 103         asm volatile (
 104                 "mrc p15, 0, %0, c15, c1, 0\n\t"
 105                 "orr %0, %0, %1\n\t"
 106                 "mcr p15, 0, %0, c15, c1, 0\n\t"
 107                 /* The action is delayed, so we have to do this: */
 108                 "mrc p15, 0, %0, c15, c1, 0\n\t"
 109                 "mov %0, %0\n\t"
 110                 "sub pc, pc, #4"
 111                 : "=r" (tmp) : "i" (1 << 6) );
 112
 113         intctl_write0(0);               // disable all interrupts
 114         intctl_write1(0);
 115         intstr_write0(0);               // treat all as IRQ
 116         intstr_write1(0);
 117         if(machine_is_iq80331())        // all interrupts are inputs to chip
 118                 *IOP331_PCIIRSR = 0x0f;
 119
 120         for(i = IOP331_IRQ_OFS; i < NR_IOP331_IRQS; i++)
 121         {
 122                 set_irq_chip(i, (i < 32) ? &iop331_irqchip1 : &iop331_irqchip2);
 123                 set_irq_handler(i, do_level_IRQ);
 124                 set_irq_flags(i, IRQF_VALID | IRQF_PROBE);
 125         }
 126 }
 127