release/src-rt-6.x.4708/linux/linux-2.6.36/arch/arm/mach-s3c2410/bast-irq.c

   1 /* linux/arch/arm/mach-s3c2410/bast-irq.c
   2  *
   3  * Copyright 2003-2005 Simtec Electronics
   4  *   Ben Dooks <ben@simtec.co.uk>
   5  *
   6  * http://www.simtec.co.uk/products/EB2410ITX/
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21 */
  22
  23
  24 #include <linux/init.h>
  25 #include <linux/module.h>
  26 #include <linux/ioport.h>
  27 #include <linux/sysdev.h>
  28 #include <linux/io.h>
  29
  30 #include <asm/mach-types.h>
  31
  32 #include <mach/hardware.h>
  33 #include <asm/irq.h>
  34
  35 #include <asm/mach/irq.h>
  36
  37 #include <mach/regs-irq.h>
  38 #include <mach/bast-map.h>
  39 #include <mach/bast-irq.h>
  40
  41 #include <plat/irq.h>
  42
  43
  44 #define irqdbf(x...)
  45 #define irqdbf2(x...)
  46
  47
  48 /* handle PC104 ISA interrupts from the system CPLD */
  49
  50 /* table of ISA irq nos to the relevant mask... zero means
  51  * the irq is not implemented
  52 */
  53 static unsigned char bast_pc104_irqmasks[] = {
  54         0,   /* 0 */
  55         0,   /* 1 */
  56         0,   /* 2 */
  57         1,   /* 3 */
  58         0,   /* 4 */
  59         2,   /* 5 */
  60         0,   /* 6 */
  61         4,   /* 7 */
  62         0,   /* 8 */
  63         0,   /* 9 */
  64         8,   /* 10 */
  65         0,   /* 11 */
  66         0,   /* 12 */
  67         0,   /* 13 */
  68         0,   /* 14 */
  69         0,   /* 15 */
  70 };
  71
  72 static unsigned char bast_pc104_irqs[] = { 3, 5, 7, 10 };
  73
  74 static void
  75 bast_pc104_mask(unsigned int irqno)
  76 {
  77         unsigned long temp;
  78
  79         temp = __raw_readb(BAST_VA_PC104_IRQMASK);
  80         temp &= ~bast_pc104_irqmasks[irqno];
  81         __raw_writeb(temp, BAST_VA_PC104_IRQMASK);
  82 }
  83
  84 static void
  85 bast_pc104_maskack(unsigned int irqno)
  86 {
  87         struct irq_desc *desc = irq_desc + IRQ_ISA;
  88
  89         bast_pc104_mask(irqno);
  90         desc->chip->ack(IRQ_ISA);
  91 }
  92
  93 static void
  94 bast_pc104_unmask(unsigned int irqno)
  95 {
  96         unsigned long temp;
  97
  98         temp = __raw_readb(BAST_VA_PC104_IRQMASK);
  99         temp |= bast_pc104_irqmasks[irqno];
 100         __raw_writeb(temp, BAST_VA_PC104_IRQMASK);
 101 }
 102
 103 static struct irq_chip  bast_pc104_chip = {
 104         .mask        = bast_pc104_mask,
 105         .unmask      = bast_pc104_unmask,
 106         .ack         = bast_pc104_maskack
 107 };
 108
 109 static void
 110 bast_irq_pc104_demux(unsigned int irq,
 111                      struct irq_desc *desc)
 112 {
 113         unsigned int stat;
 114         unsigned int irqno;
 115         int i;
 116
 117         stat = __raw_readb(BAST_VA_PC104_IRQREQ) & 0xf;
 118
 119         if (unlikely(stat == 0)) {
 120                 /* ack if we get an irq with nothing (ie, startup) */
 121
 122                 desc = irq_desc + IRQ_ISA;
 123                 desc->chip->ack(IRQ_ISA);
 124         } else {
 125                 /* handle the IRQ */
 126
 127                 for (i = 0; stat != 0; i++, stat >>= 1) {
 128                         if (stat & 1) {
 129                                 irqno = bast_pc104_irqs[i];
 130                                 generic_handle_irq(irqno);
 131                         }
 132                 }
 133         }
 134 }
 135
 136 static __init int bast_irq_init(void)
 137 {
 138         unsigned int i;
 139
 140         if (machine_is_bast()) {
 141                 printk(KERN_INFO "BAST PC104 IRQ routing, Copyright 2005 Simtec Electronics\n");
 142
 143                 /* zap all the IRQs */
 144
 145                 __raw_writeb(0x0, BAST_VA_PC104_IRQMASK);
 146
 147                 set_irq_chained_handler(IRQ_ISA, bast_irq_pc104_demux);
 148
 149                 /* register our IRQs */
 150
 151                 for (i = 0; i < 4; i++) {
 152                         unsigned int irqno = bast_pc104_irqs[i];
 153
 154                         set_irq_chip(irqno, &bast_pc104_chip);
 155                         set_irq_handler(irqno, handle_level_irq);
 156                         set_irq_flags(irqno, IRQF_VALID);
 157                 }
 158         }
 159
 160         return 0;
 161 }
 162
 163 arch_initcall(bast_irq_init);