arch/mips/kernel/irq-rm7000.c

   1 /*
   2  * Copyright (C) 2003 Ralf Baechle
   3  *
   4  * This program is free software; you can redistribute  it and/or modify it
   5  * under  the terms of  the GNU General  Public License as published by the
   6  * Free Software Foundation;  either version 2 of the  License, or (at your
   7  * option) any later version.
   8  *
   9  * Handler for RM7000 extended interrupts.  These are a non-standard
  10  * feature so we handle them separately from standard interrupts.
  11  */
  12 #include <linux/init.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/kernel.h>
  15
  16 #include <asm/irq_cpu.h>
  17 #include <asm/mipsregs.h>
  18 #include <asm/system.h>
  19
  20 static int irq_base;
  21
  22 static inline void unmask_rm7k_irq(unsigned int irq)
  23 {
  24         set_c0_intcontrol(0x100 << (irq - irq_base));
  25 }
  26
  27 static inline void mask_rm7k_irq(unsigned int irq)
  28 {
  29         clear_c0_intcontrol(0x100 << (irq - irq_base));
  30 }
  31
  32 static inline void rm7k_cpu_irq_enable(unsigned int irq)
  33 {
  34         unsigned long flags;
  35
  36         local_irq_save(flags);
  37         unmask_rm7k_irq(irq);
  38         local_irq_restore(flags);
  39 }
  40
  41 static void rm7k_cpu_irq_disable(unsigned int irq)
  42 {
  43         unsigned long flags;
  44
  45         local_irq_save(flags);
  46         mask_rm7k_irq(irq);
  47         local_irq_restore(flags);
  48 }
  49
  50 static unsigned int rm7k_cpu_irq_startup(unsigned int irq)
  51 {
  52         rm7k_cpu_irq_enable(irq);
  53
  54         return 0;
  55 }
  56
  57 #define rm7k_cpu_irq_shutdown   rm7k_cpu_irq_disable
  58
  59 /*
  60  * While we ack the interrupt interrupts are disabled and thus we don't need
  61  * to deal with concurrency issues.  Same for rm7k_cpu_irq_end.
  62  */
  63 static void rm7k_cpu_irq_ack(unsigned int irq)
  64 {
  65         mask_rm7k_irq(irq);
  66 }
  67
  68 static void rm7k_cpu_irq_end(unsigned int irq)
  69 {
  70         if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
  71                 unmask_rm7k_irq(irq);
  72 }
  73
  74 static hw_irq_controller rm7k_irq_controller = {
  75         "RM7000",
  76         rm7k_cpu_irq_startup,
  77         rm7k_cpu_irq_shutdown,
  78         rm7k_cpu_irq_enable,
  79         rm7k_cpu_irq_disable,
  80         rm7k_cpu_irq_ack,
  81         rm7k_cpu_irq_end,
  82 };
  83
  84 void __init rm7k_cpu_irq_init(int base)
  85 {
  86         int i;
  87
  88         clear_c0_intcontrol(0x00000f00);                /* Mask all */
  89
  90         for (i = base; i < base + 4; i++) {
  91                 irq_desc[i].status = IRQ_DISABLED;
  92                 irq_desc[i].action = NULL;
  93                 irq_desc[i].depth = 1;
  94                 irq_desc[i].handler = &rm7k_irq_controller;
  95         }
  96
  97         irq_base = base;
  98 }