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