arch/arm/mach-s3c2410/bast-irq.c

   1 /* linux/arch/arm/mach-s3c2410/bast-irq.c
   2  *
   3  * Copyright (c) 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  * Modifications:
  23  *     08-Jan-2003 BJD  Moved from central IRQ code
  24  *     21-Aug-2005 BJD  Fixed missing code and compile errors
  25 */
  26
  27
  28 #include <linux/init.h>
  29 #include <linux/module.h>
  30 #include <linux/ioport.h>
  31 #include <linux/ptrace.h>
  32 #include <linux/sysdev.h>
  33
  34 #include <asm/mach-types.h>
  35
  36 #include <asm/hardware.h>
  37 #include <asm/irq.h>
  38 #include <asm/io.h>
  39
  40 #include <asm/mach/irq.h>
  41
  42 #include <asm/arch/regs-irq.h>
  43 #include <asm/arch/bast-map.h>
  44 #include <asm/arch/bast-irq.h>
  45
  46 #include "irq.h"
  47
  48 #if 0
  49 #include <asm/debug-ll.h>
  50 #endif
  51
  52 #define irqdbf(x...)
  53 #define irqdbf2(x...)
  54
  55
  56 /* handle PC104 ISA interrupts from the system CPLD */
  57
  58 /* table of ISA irq nos to the relevant mask... zero means
  59  * the irq is not implemented
  60 */
  61 static unsigned char bast_pc104_irqmasks[] = {
  62         0,   /* 0 */
  63         0,   /* 1 */
  64         0,   /* 2 */
  65         1,   /* 3 */
  66         0,   /* 4 */
  67         2,   /* 5 */
  68         0,   /* 6 */
  69         4,   /* 7 */
  70         0,   /* 8 */
  71         0,   /* 9 */
  72         8,   /* 10 */
  73         0,   /* 11 */
  74         0,   /* 12 */
  75         0,   /* 13 */
  76         0,   /* 14 */
  77         0,   /* 15 */
  78 };
  79
  80 static unsigned char bast_pc104_irqs[] = { 3, 5, 7, 10 };
  81
  82 static void
  83 bast_pc104_mask(unsigned int irqno)
  84 {
  85         unsigned long temp;
  86
  87         temp = __raw_readb(BAST_VA_PC104_IRQMASK);
  88         temp &= ~bast_pc104_irqmasks[irqno];
  89         __raw_writeb(temp, BAST_VA_PC104_IRQMASK);
  90 }
  91
  92 static void
  93 bast_pc104_maskack(unsigned int irqno)
  94 {
  95         struct irqdesc *desc = irq_desc + IRQ_ISA;
  96
  97         bast_pc104_mask(irqno);
  98         desc->chip->ack(IRQ_ISA);
  99 }
 100
 101 static void
 102 bast_pc104_unmask(unsigned int irqno)
 103 {
 104         unsigned long temp;
 105
 106         temp = __raw_readb(BAST_VA_PC104_IRQMASK);
 107         temp |= bast_pc104_irqmasks[irqno];
 108         __raw_writeb(temp, BAST_VA_PC104_IRQMASK);
 109 }
 110
 111 static struct irqchip  bast_pc104_chip = {
 112         .mask        = bast_pc104_mask,
 113         .unmask      = bast_pc104_unmask,
 114         .ack         = bast_pc104_maskack
 115 };
 116
 117 static void
 118 bast_irq_pc104_demux(unsigned int irq,
 119                      struct irqdesc *desc,
 120                      struct pt_regs *regs)
 121 {
 122         unsigned int stat;
 123         unsigned int irqno;
 124         int i;
 125
 126         stat = __raw_readb(BAST_VA_PC104_IRQREQ) & 0xf;
 127
 128         if (unlikely(stat == 0)) {
 129                 /* ack if we get an irq with nothing (ie, startup) */
 130
 131                 desc = irq_desc + IRQ_ISA;
 132                 desc->chip->ack(IRQ_ISA);
 133         } else {
 134                 /* handle the IRQ */
 135
 136                 for (i = 0; stat != 0; i++, stat >>= 1) {
 137                         if (stat & 1) {
 138                                 irqno = bast_pc104_irqs[i];
 139
 140                                 desc_handle_irq(irqno, irq_desc + irqno, regs);
 141                         }
 142                 }
 143         }
 144 }
 145
 146 static __init int bast_irq_init(void)
 147 {
 148         unsigned int i;
 149
 150         if (machine_is_bast()) {
 151                 printk(KERN_INFO "BAST PC104 IRQ routing, (c) 2005 Simtec Electronics\n");
 152
 153                 /* zap all the IRQs */
 154
 155                 __raw_writeb(0x0, BAST_VA_PC104_IRQMASK);
 156
 157                 set_irq_chained_handler(IRQ_ISA, bast_irq_pc104_demux);
 158
 159                 /* reigster our IRQs */
 160
 161                 for (i = 0; i < 4; i++) {
 162                         unsigned int irqno = bast_pc104_irqs[i];
 163
 164                         set_irq_chip(irqno, &bast_pc104_chip);
 165                         set_irq_handler(irqno, do_level_IRQ);
 166                         set_irq_flags(irqno, IRQF_VALID);
 167                 }
 168         }
 169
 170         return 0;
 171 }
 172
 173 arch_initcall(bast_irq_init);