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

   1 /*
   2  * linux/arch/sh/boards/renesas/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/init.h>
  13 #include <linux/irq.h>
  14
  15 #include <linux/hdreg.h>
  16 #include <linux/ide.h>
  17 #include <asm/io.h>
  18 #include <asm/systemh7751.h>
  19 #include <asm/smc37c93x.h>
  20
  21 /* address of external interrupt mask register
  22  * address must be set prior to use these (maybe in init_XXX_irq())
  23  * XXX : is it better to use .config than specifying it in code? */
  24 static unsigned long *systemh_irq_mask_register = (unsigned long *)0xB3F10004;
  25 static unsigned long *systemh_irq_request_register = (unsigned long *)0xB3F10000;
  26
  27 /* forward declaration */
  28 static unsigned int startup_systemh_irq(unsigned int irq);
  29 static void shutdown_systemh_irq(unsigned int irq);
  30 static void enable_systemh_irq(unsigned int irq);
  31 static void disable_systemh_irq(unsigned int irq);
  32 static void mask_and_ack_systemh(unsigned int);
  33 static void end_systemh_irq(unsigned int irq);
  34
  35 /* hw_interrupt_type */
  36 static struct hw_interrupt_type systemh_irq_type = {
  37         .typename = " SystemH Register",
  38         .startup = startup_systemh_irq,
  39         .shutdown = shutdown_systemh_irq,
  40         .enable = enable_systemh_irq,
  41         .disable = disable_systemh_irq,
  42         .ack = mask_and_ack_systemh,
  43         .end = end_systemh_irq
  44 };
  45
  46 static unsigned int startup_systemh_irq(unsigned int irq)
  47 {
  48         enable_systemh_irq(irq);
  49         return 0; /* never anything pending */
  50 }
  51
  52 static void shutdown_systemh_irq(unsigned int irq)
  53 {
  54         disable_systemh_irq(irq);
  55 }
  56
  57 static void disable_systemh_irq(unsigned int irq)
  58 {
  59         if (systemh_irq_mask_register) {
  60                 unsigned long val, mask = 0x01 << 1;
  61
  62                 /* Clear the "irq"th bit in the mask and set it in the request */
  63                 val = ctrl_inl((unsigned long)systemh_irq_mask_register);
  64                 val &= ~mask;
  65                 ctrl_outl(val, (unsigned long)systemh_irq_mask_register);
  66
  67                 val = ctrl_inl((unsigned long)systemh_irq_request_register);
  68                 val |= mask;
  69                 ctrl_outl(val, (unsigned long)systemh_irq_request_register);
  70         }
  71 }
  72
  73 static void enable_systemh_irq(unsigned int irq)
  74 {
  75         if (systemh_irq_mask_register) {
  76                 unsigned long val, mask = 0x01 << 1;
  77
  78                 /* Set "irq"th bit in the mask register */
  79                 val = ctrl_inl((unsigned long)systemh_irq_mask_register);
  80                 val |= mask;
  81                 ctrl_outl(val, (unsigned long)systemh_irq_mask_register);
  82         }
  83 }
  84
  85 static void mask_and_ack_systemh(unsigned int irq)
  86 {
  87         disable_systemh_irq(irq);
  88 }
  89
  90 static void end_systemh_irq(unsigned int irq)
  91 {
  92         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
  93                 enable_systemh_irq(irq);
  94 }
  95
  96 void make_systemh_irq(unsigned int irq)
  97 {
  98         disable_irq_nosync(irq);
  99         irq_desc[irq].chip = &systemh_irq_type;
 100         disable_systemh_irq(irq);
 101 }
 102