arch/arm/mach-s3c24xx/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/device.h>
  28 #include <linux/io.h>
  29
  30 #include <asm/irq.h>
  31 #include <asm/mach-types.h>
  32 #include <asm/mach/irq.h>
  33
  34 #include <mach/hardware.h>
  35 #include <mach/regs-irq.h>
  36
  37 #include "bast.h"
  38
  39 #define irqdbf(x...)
  40 #define irqdbf2(x...)
  41
  42 /* handle PC104 ISA interrupts from the system CPLD */
  43
  44 /* table of ISA irq nos to the relevant mask... zero means
  45  * the irq is not implemented
  46 */
  47 static unsigned char bast_pc104_irqmasks[] = {
  48         0,   /* 0 */
  49         0,   /* 1 */
  50         0,   /* 2 */
  51         1,   /* 3 */
  52         0,   /* 4 */
  53         2,   /* 5 */
  54         0,   /* 6 */
  55         4,   /* 7 */
  56         0,   /* 8 */
  57         0,   /* 9 */
  58         8,   /* 10 */
  59         0,   /* 11 */
  60         0,   /* 12 */
  61         0,   /* 13 */
  62         0,   /* 14 */
  63         0,   /* 15 */
  64 };
  65
  66 static unsigned char bast_pc104_irqs[] = { 3, 5, 7, 10 };
  67
  68 static void
  69 bast_pc104_mask(struct irq_data *data)
  70 {
  71         unsigned long temp;
  72
  73         temp = __raw_readb(BAST_VA_PC104_IRQMASK);
  74         temp &= ~bast_pc104_irqmasks[data->irq];
  75         __raw_writeb(temp, BAST_VA_PC104_IRQMASK);
  76 }
  77
  78 static void
  79 bast_pc104_maskack(struct irq_data *data)
  80 {
  81         struct irq_desc *desc = irq_desc + BAST_IRQ_ISA;
  82
  83         bast_pc104_mask(data);
  84         desc->irq_data.chip->irq_ack(&desc->irq_data);
  85 }
  86
  87 static void
  88 bast_pc104_unmask(struct irq_data *data)
  89 {
  90         unsigned long temp;
  91
  92         temp = __raw_readb(BAST_VA_PC104_IRQMASK);
  93         temp |= bast_pc104_irqmasks[data->irq];
  94         __raw_writeb(temp, BAST_VA_PC104_IRQMASK);
  95 }
  96
  97 static struct irq_chip  bast_pc104_chip = {
  98         .irq_mask       = bast_pc104_mask,
  99         .irq_unmask     = bast_pc104_unmask,
 100         .irq_ack        = bast_pc104_maskack
 101 };
 102
 103 static void
 104 bast_irq_pc104_demux(unsigned int irq,
 105                      struct irq_desc *desc)
 106 {
 107         unsigned int stat;
 108         unsigned int irqno;
 109         int i;
 110
 111         stat = __raw_readb(BAST_VA_PC104_IRQREQ) & 0xf;
 112
 113         if (unlikely(stat == 0)) {
 114                 /* ack if we get an irq with nothing (ie, startup) */
 115
 116                 desc = irq_desc + BAST_IRQ_ISA;
 117                 desc->irq_data.chip->irq_ack(&desc->irq_data);
 118         } else {
 119                 /* handle the IRQ */
 120
 121                 for (i = 0; stat != 0; i++, stat >>= 1) {
 122                         if (stat & 1) {
 123                                 irqno = bast_pc104_irqs[i];
 124                                 generic_handle_irq(irqno);
 125                         }
 126                 }
 127         }
 128 }
 129
 130 static __init int bast_irq_init(void)
 131 {
 132         unsigned int i;
 133
 134         if (machine_is_bast()) {
 135                 printk(KERN_INFO "BAST PC104 IRQ routing, Copyright 2005 Simtec Electronics\n");
 136
 137                 /* zap all the IRQs */
 138
 139                 __raw_writeb(0x0, BAST_VA_PC104_IRQMASK);
 140
 141                 irq_set_chained_handler(BAST_IRQ_ISA, bast_irq_pc104_demux);
 142
 143                 /* register our IRQs */
 144
 145                 for (i = 0; i < 4; i++) {
 146                         unsigned int irqno = bast_pc104_irqs[i];
 147
 148                         irq_set_chip_and_handler(irqno, &bast_pc104_chip,
 149                                                  handle_level_irq);
 150                         set_irq_flags(irqno, IRQF_VALID);
 151                 }
 152         }
 153
 154         return 0;
 155 }
 156
 157 arch_initcall(bast_irq_init);