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