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