root/arch/arm/mach-s3c24xx/bast-irq.c

DEFINITIONS

1. bast_pc104_mask
2. bast_pc104_maskack
3. bast_pc104_unmask
4. bast_irq_pc104_demux
5. bast_irq_init

   1 // SPDX-License-Identifier: GPL-2.0+
   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 #include <linux/init.h>
   9 #include <linux/module.h>
  10 #include <linux/ioport.h>
  11 #include <linux/device.h>
  12 #include <linux/io.h>
  13 
  14 #include <asm/irq.h>
  15 #include <asm/mach-types.h>
  16 #include <asm/mach/irq.h>
  17 
  18 #include <mach/hardware.h>
  19 #include <mach/regs-irq.h>
  20 
  21 #include "bast.h"
  22 
  23 #define irqdbf(x...)
  24 #define irqdbf2(x...)
  25 
  26 /* handle PC104 ISA interrupts from the system CPLD */
  27 
  28 /* table of ISA irq nos to the relevant mask... zero means
  29  * the irq is not implemented
  30 */
  31 static const unsigned char bast_pc104_irqmasks[] = {
  32         0,   /* 0 */
  33         0,   /* 1 */
  34         0,   /* 2 */
  35         1,   /* 3 */
  36         0,   /* 4 */
  37         2,   /* 5 */
  38         0,   /* 6 */
  39         4,   /* 7 */
  40         0,   /* 8 */
  41         0,   /* 9 */
  42         8,   /* 10 */
  43         0,   /* 11 */
  44         0,   /* 12 */
  45         0,   /* 13 */
  46         0,   /* 14 */
  47         0,   /* 15 */
  48 };
  49 
  50 static const unsigned char bast_pc104_irqs[] = { 3, 5, 7, 10 };
  51 
  52 static void
  53 bast_pc104_mask(struct irq_data *data)
  54 {
  55         unsigned long temp;
  56 
  57         temp = __raw_readb(BAST_VA_PC104_IRQMASK);
  58         temp &= ~bast_pc104_irqmasks[data->irq];
  59         __raw_writeb(temp, BAST_VA_PC104_IRQMASK);
  60 }
  61 
  62 static void
  63 bast_pc104_maskack(struct irq_data *data)
  64 {
  65         struct irq_desc *desc = irq_desc + BAST_IRQ_ISA;
  66 
  67         bast_pc104_mask(data);
  68         desc->irq_data.chip->irq_ack(&desc->irq_data);
  69 }
  70 
  71 static void
  72 bast_pc104_unmask(struct irq_data *data)
  73 {
  74         unsigned long temp;
  75 
  76         temp = __raw_readb(BAST_VA_PC104_IRQMASK);
  77         temp |= bast_pc104_irqmasks[data->irq];
  78         __raw_writeb(temp, BAST_VA_PC104_IRQMASK);
  79 }
  80 
  81 static struct irq_chip  bast_pc104_chip = {
  82         .irq_mask       = bast_pc104_mask,
  83         .irq_unmask     = bast_pc104_unmask,
  84         .irq_ack        = bast_pc104_maskack
  85 };
  86 
  87 static void bast_irq_pc104_demux(struct irq_desc *desc)
  88 {
  89         unsigned int stat;
  90         unsigned int irqno;
  91         int i;
  92 
  93         stat = __raw_readb(BAST_VA_PC104_IRQREQ) & 0xf;
  94 
  95         if (unlikely(stat == 0)) {
  96                 /* ack if we get an irq with nothing (ie, startup) */
  97 
  98                 desc = irq_desc + BAST_IRQ_ISA;
  99                 desc->irq_data.chip->irq_ack(&desc->irq_data);
 100         } else {
 101                 /* handle the IRQ */
 102 
 103                 for (i = 0; stat != 0; i++, stat >>= 1) {
 104                         if (stat & 1) {
 105                                 irqno = bast_pc104_irqs[i];
 106                                 generic_handle_irq(irqno);
 107                         }
 108                 }
 109         }
 110 }
 111 
 112 static __init int bast_irq_init(void)
 113 {
 114         unsigned int i;
 115 
 116         if (machine_is_bast()) {
 117                 printk(KERN_INFO "BAST PC104 IRQ routing, Copyright 2005 Simtec Electronics\n");
 118 
 119                 /* zap all the IRQs */
 120 
 121                 __raw_writeb(0x0, BAST_VA_PC104_IRQMASK);
 122 
 123                 irq_set_chained_handler(BAST_IRQ_ISA, bast_irq_pc104_demux);
 124 
 125                 /* register our IRQs */
 126 
 127                 for (i = 0; i < 4; i++) {
 128                         unsigned int irqno = bast_pc104_irqs[i];
 129 
 130                         irq_set_chip_and_handler(irqno, &bast_pc104_chip,
 131                                                  handle_level_irq);
 132                         irq_clear_status_flags(irqno, IRQ_NOREQUEST);
 133                 }
 134         }
 135 
 136         return 0;
 137 }
 138 
 139 arch_initcall(bast_irq_init);