release/src-rt-6.x.4708/linux/linux-2.6.36/arch/mips/wrppmc/irq.c

   1 /*
   2  * irq.c: GT64120 Interrupt Controller
   3  *
   4  * Copyright (C) 2006, Wind River System Inc.
   5  * Author: Rongkai.Zhan, <rongkai.zhan@windriver.com>
   6  *
   7  * This program is free software; you can redistribute  it and/or modify it
   8  * under  the terms of  the GNU General  Public License as published by the
   9  * Free Software Foundation;  either version 2 of the  License, or (at your
  10  * option) any later version.
  11  */
  12 #include <linux/hardirq.h>
  13 #include <linux/init.h>
  14 #include <linux/irq.h>
  15
  16 #include <asm/gt64120.h>
  17 #include <asm/irq_cpu.h>
  18 #include <asm/mipsregs.h>
  19
  20 asmlinkage void plat_irq_dispatch(void)
  21 {
  22         unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
  23
  24         if (pending & STATUSF_IP7)
  25                 do_IRQ(WRPPMC_MIPS_TIMER_IRQ);  /* CPU Compare/Count internal timer */
  26         else if (pending & STATUSF_IP6)
  27                 do_IRQ(WRPPMC_UART16550_IRQ);   /* UART 16550 port */
  28         else if (pending & STATUSF_IP3)
  29                 do_IRQ(WRPPMC_PCI_INTA_IRQ);    /* PCI INT_A */
  30         else
  31                 spurious_interrupt();
  32 }
  33
  34 /**
  35  * Initialize GT64120 Interrupt Controller
  36  */
  37 void gt64120_init_pic(void)
  38 {
  39         /* clear CPU Interrupt Cause Registers */
  40         GT_WRITE(GT_INTRCAUSE_OFS, (0x1F << 21));
  41         GT_WRITE(GT_HINTRCAUSE_OFS, 0x00);
  42
  43         /* Disable all interrupts from GT64120 bridge chip */
  44         GT_WRITE(GT_INTRMASK_OFS, 0x00);
  45         GT_WRITE(GT_HINTRMASK_OFS, 0x00);
  46         GT_WRITE(GT_PCI0_ICMASK_OFS, 0x00);
  47         GT_WRITE(GT_PCI0_HICMASK_OFS, 0x00);
  48 }
  49
  50 void __init arch_init_irq(void)
  51 {
  52         /* IRQ 0 - 7 are for MIPS common irq_cpu controller */
  53         mips_cpu_irq_init();
  54
  55         gt64120_init_pic();
  56 }