release/src-rt-6.x.4708/linux/linux-2.6.36/arch/mips/brcm-boards/generic/irq.c

   1 /*
   2  * Generic interrupt control functions for Broadcom MIPS boards
   3  *
   4  * Copyright (C) 2012, Broadcom Corporation. All Rights Reserved.
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  13  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
  15  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  16  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  *
  18  * $Id: irq.c,v 1.1 2007-09-04 04:41:12 $
  19  */
  20
  21 #include <linux/config.h>
  22 #include <linux/init.h>
  23 #include <linux/kernel.h>
  24 #include <linux/types.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/irq.h>
  27
  28 #include <asm/irq.h>
  29 #include <asm/mipsregs.h>
  30 #include <asm/gdb-stub.h>
  31
  32 #define ALLINTS (IE_IRQ0 | IE_IRQ1 | IE_IRQ2 | IE_IRQ3 | IE_IRQ4 | IE_IRQ5)
  33
  34 extern asmlinkage void brcmIRQ(void);
  35 extern asmlinkage unsigned int do_IRQ(int irq, struct pt_regs *regs);
  36
  37 void
  38 plat_irq_dispatch(struct pt_regs *regs)
  39 {
  40         u32 cause;
  41
  42         cause = read_c0_cause() &
  43                 read_c0_status() &
  44                 CAUSEF_IP;
  45
  46 #ifdef CONFIG_KERNPROF
  47         change_c0_status(cause | 1, 1);
  48 #else
  49         clear_c0_status(cause);
  50 #endif
  51
  52         if (cause & CAUSEF_IP7)
  53                 do_IRQ(7, regs);
  54         if (cause & CAUSEF_IP2)
  55                 do_IRQ(2, regs);
  56         if (cause & CAUSEF_IP3)
  57                 do_IRQ(3, regs);
  58         if (cause & CAUSEF_IP4)
  59                 do_IRQ(4, regs);
  60         if (cause & CAUSEF_IP5)
  61                 do_IRQ(5, regs);
  62         if (cause & CAUSEF_IP6)
  63                 do_IRQ(6, regs);
  64 }
  65
  66 static void
  67 enable_brcm_irq(unsigned int irq)
  68 {
  69         if (irq < 8)
  70                 set_c0_status(1 << (irq + 8));
  71         else
  72                 set_c0_status(IE_IRQ0);
  73 }
  74
  75 static void
  76 disable_brcm_irq(unsigned int irq)
  77 {
  78         if (irq < 8)
  79                 clear_c0_status(1 << (irq + 8));
  80         else
  81                 clear_c0_status(IE_IRQ0);
  82 }
  83
  84 static void
  85 ack_brcm_irq(unsigned int irq)
  86 {
  87         /* Already done in plat_irq_dispatch */
  88 }
  89
  90 static unsigned int
  91 startup_brcm_irq(unsigned int irq)
  92 {
  93         enable_brcm_irq(irq);
  94
  95         return 0; /* never anything pending */
  96 }
  97
  98 static void
  99 end_brcm_irq(unsigned int irq)
 100 {
 101         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
 102                 enable_brcm_irq(irq);
 103 }
 104
 105 static struct hw_interrupt_type brcm_irq_type = {
 106         typename: "MIPS",
 107         startup: startup_brcm_irq,
 108         shutdown: disable_brcm_irq,
 109         enable: enable_brcm_irq,
 110         disable: disable_brcm_irq,
 111         ack: ack_brcm_irq,
 112         end: end_brcm_irq,
 113         NULL
 114 };
 115
 116 void __init
 117 init_IRQ(void)
 118 {
 119         int i;
 120
 121         for (i = 0; i < NR_IRQS; i++) {
 122                 irq_desc[i].status = IRQ_DISABLED;
 123                 irq_desc[i].action = 0;
 124                 irq_desc[i].depth = 1;
 125                 irq_desc[i].handler = &brcm_irq_type;
 126         }
 127
 128         change_c0_status(ST0_IM, ALLINTS);
 129
 130 #ifdef CONFIG_KGDB
 131         printk("Breaking into debugger...\n");
 132         set_debug_traps();
 133         breakpoint();
 134 #endif
 135 }