arch/sh/boards/renesas/systemh/irq.c

   1 /*
   2  * linux/arch/sh/boards/systemh/irq.c
   3  *
   4  * Copyright (C) 2000  Kazumoto Kojima
   5  *
   6  * Hitachi SystemH Support.
   7  *
   8  * Modified for 7751 SystemH by
   9  * Jonathan Short.
  10  */
  11
  12 #include <linux/config.h>
  13 #include <linux/init.h>
  14 #include <linux/irq.h>
  15
  16 #include <linux/hdreg.h>
  17 #include <linux/ide.h>
  18 #include <asm/io.h>
  19 #include <asm/mach/7751systemh.h>
  20 #include <asm/smc37c93x.h>
  21
  22 /* address of external interrupt mask register
  23  * address must be set prior to use these (maybe in init_XXX_irq())
  24  * XXX : is it better to use .config than specifying it in code? */
  25 static unsigned long *systemh_irq_mask_register = (unsigned long *)0xB3F10004;
  26 static unsigned long *systemh_irq_request_register = (unsigned long *)0xB3F10000;
  27
  28 /* forward declaration */
  29 static unsigned int startup_systemh_irq(unsigned int irq);
  30 static void shutdown_systemh_irq(unsigned int irq);
  31 static void enable_systemh_irq(unsigned int irq);
  32 static void disable_systemh_irq(unsigned int irq);
  33 static void mask_and_ack_systemh(unsigned int);
  34 static void end_systemh_irq(unsigned int irq);
  35
  36 /* hw_interrupt_type */
  37 static struct hw_interrupt_type systemh_irq_type = {
  38         " SystemH Register",
  39         startup_systemh_irq,
  40         shutdown_systemh_irq,
  41         enable_systemh_irq,
  42         disable_systemh_irq,
  43         mask_and_ack_systemh,
  44         end_systemh_irq
  45 };
  46
  47 static unsigned int startup_systemh_irq(unsigned int irq)
  48 {
  49         enable_systemh_irq(irq);
  50         return 0; /* never anything pending */
  51 }
  52
  53 static void shutdown_systemh_irq(unsigned int irq)
  54 {
  55         disable_systemh_irq(irq);
  56 }
  57
  58 static void disable_systemh_irq(unsigned int irq)
  59 {
  60         if (systemh_irq_mask_register) {
  61                 unsigned long flags;
  62                 unsigned long val, mask = 0x01 << 1;
  63
  64                 /* Clear the "irq"th bit in the mask and set it in the request */
  65                 local_irq_save(flags);
  66
  67                 val = ctrl_inl((unsigned long)systemh_irq_mask_register);
  68                 val &= ~mask;
  69                 ctrl_outl(val, (unsigned long)systemh_irq_mask_register);
  70
  71                 val = ctrl_inl((unsigned long)systemh_irq_request_register);
  72                 val |= mask;
  73                 ctrl_outl(val, (unsigned long)systemh_irq_request_register);
  74
  75                 local_irq_restore(flags);
  76         }
  77 }
  78
  79 static void enable_systemh_irq(unsigned int irq)
  80 {
  81         if (systemh_irq_mask_register) {
  82                 unsigned long flags;
  83                 unsigned long val, mask = 0x01 << 1;
  84
  85                 /* Set "irq"th bit in the mask register */
  86                 local_irq_save(flags);
  87                 val = ctrl_inl((unsigned long)systemh_irq_mask_register);
  88                 val |= mask;
  89                 ctrl_outl(val, (unsigned long)systemh_irq_mask_register);
  90                 local_irq_restore(flags);
  91         }
  92 }
  93
  94 static void mask_and_ack_systemh(unsigned int irq)
  95 {
  96         disable_systemh_irq(irq);
  97 }
  98
  99 static void end_systemh_irq(unsigned int irq)
 100 {
 101         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
 102                 enable_systemh_irq(irq);
 103 }
 104
 105 void make_systemh_irq(unsigned int irq)
 106 {
 107         disable_irq_nosync(irq);
 108         irq_desc[irq].handler = &systemh_irq_type;
 109         disable_systemh_irq(irq);
 110 }
 111