target/linux/brcm-2.4/files/arch/mips/bcm947xx/generic/irq.c

   1 /*
   2  * Generic interrupt control functions for Broadcom MIPS boards
   3  *
   4  * Copyright 2004, Broadcom Corporation
   5  * All Rights Reserved.
   6  *
   7  * THIS SOFTWARE IS OFFERED "AS IS", AND BROADCOM GRANTS NO WARRANTIES OF ANY
   8  * KIND, EXPRESS OR IMPLIED, BY STATUTE, COMMUNICATION OR OTHERWISE. BROADCOM
   9  * SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS
  10  * FOR A SPECIFIC PURPOSE OR NONINFRINGEMENT CONCERNING THIS SOFTWARE.
  11  *
  12  */
  13
  14 #include <linux/config.h>
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <linux/types.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/irq.h>
  20
  21 #include <asm/irq.h>
  22 #include <asm/mipsregs.h>
  23 #include <asm/gdb-stub.h>
  24
  25 #define ALLINTS (IE_IRQ0 | IE_IRQ1 | IE_IRQ2 | IE_IRQ3 | IE_IRQ4 | IE_IRQ5)
  26
  27 extern asmlinkage void brcmIRQ(void);
  28 extern asmlinkage unsigned int do_IRQ(int irq, struct pt_regs *regs);
  29
  30 void
  31 brcm_irq_dispatch(struct pt_regs *regs)
  32 {
  33         u32 cause;
  34
  35         cause = read_c0_cause() &
  36                 read_c0_status() &
  37                 CAUSEF_IP;
  38
  39 #ifdef CONFIG_KERNPROF
  40         change_c0_status(cause | 1, 1);
  41 #else
  42         clear_c0_status(cause);
  43 #endif
  44
  45         if (cause & CAUSEF_IP7)
  46                 do_IRQ(7, regs);
  47         if (cause & CAUSEF_IP2)
  48                 do_IRQ(2, regs);
  49         if (cause & CAUSEF_IP3)
  50                 do_IRQ(3, regs);
  51         if (cause & CAUSEF_IP4)
  52                 do_IRQ(4, regs);
  53         if (cause & CAUSEF_IP5)
  54                 do_IRQ(5, regs);
  55         if (cause & CAUSEF_IP6)
  56                 do_IRQ(6, regs);
  57 }
  58
  59 static void
  60 enable_brcm_irq(unsigned int irq)
  61 {
  62         if (irq < 8)
  63                 set_c0_status(1 << (irq + 8));
  64         else
  65                 set_c0_status(IE_IRQ0);
  66 }
  67
  68 static void
  69 disable_brcm_irq(unsigned int irq)
  70 {
  71         if (irq < 8)
  72                 clear_c0_status(1 << (irq + 8));
  73         else
  74                 clear_c0_status(IE_IRQ0);
  75 }
  76
  77 static void
  78 ack_brcm_irq(unsigned int irq)
  79 {
  80         /* Already done in brcm_irq_dispatch */
  81 }
  82
  83 static unsigned int
  84 startup_brcm_irq(unsigned int irq)
  85 {
  86         enable_brcm_irq(irq);
  87
  88         return 0; /* never anything pending */
  89 }
  90
  91 static void
  92 end_brcm_irq(unsigned int irq)
  93 {
  94         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
  95                 enable_brcm_irq(irq);
  96 }
  97
  98 static struct hw_interrupt_type brcm_irq_type = {
  99         typename: "MIPS",
 100         startup: startup_brcm_irq,
 101         shutdown: disable_brcm_irq,
 102         enable: enable_brcm_irq,
 103         disable: disable_brcm_irq,
 104         ack: ack_brcm_irq,
 105         end: end_brcm_irq,
 106         NULL
 107 };
 108
 109 void __init
 110 init_IRQ(void)
 111 {
 112         int i;
 113
 114         for (i = 0; i < NR_IRQS; i++) {
 115                 irq_desc[i].status = IRQ_DISABLED;
 116                 irq_desc[i].action = 0;
 117                 irq_desc[i].depth = 1;
 118                 irq_desc[i].handler = &brcm_irq_type;
 119         }
 120
 121         set_except_vector(0, brcmIRQ);
 122         change_c0_status(ST0_IM, ALLINTS);
 123
 124 #ifdef CONFIG_REMOTE_DEBUG
 125         printk("Breaking into debugger...\n");
 126         set_debug_traps();
 127         breakpoint();
 128 #endif
 129 }