arch/mips/jazz/irq.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1992 Linus Torvalds
   7  * Copyright (C) 1994 - 2001, 2003 Ralf Baechle
   8  */
   9 #include <linux/init.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/kernel.h>
  12 #include <linux/spinlock.h>
  13
  14 #include <asm/i8259.h>
  15 #include <asm/io.h>
  16 #include <asm/jazz.h>
  17
  18 extern asmlinkage void jazz_handle_int(void);
  19
  20 static DEFINE_SPINLOCK(r4030_lock);
  21
  22 static void enable_r4030_irq(unsigned int irq)
  23 {
  24         unsigned int mask = 1 << (irq - JAZZ_PARALLEL_IRQ);
  25         unsigned long flags;
  26
  27         spin_lock_irqsave(&r4030_lock, flags);
  28         mask |= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
  29         r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
  30         spin_unlock_irqrestore(&r4030_lock, flags);
  31 }
  32
  33 static unsigned int startup_r4030_irq(unsigned int irq)
  34 {
  35         enable_r4030_irq(irq);
  36         return 0; /* never anything pending */
  37 }
  38
  39 #define shutdown_r4030_irq      disable_r4030_irq
  40
  41 void disable_r4030_irq(unsigned int irq)
  42 {
  43         unsigned int mask = ~(1 << (irq - JAZZ_PARALLEL_IRQ));
  44         unsigned long flags;
  45
  46         spin_lock_irqsave(&r4030_lock, flags);
  47         mask &= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
  48         r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
  49         spin_unlock_irqrestore(&r4030_lock, flags);
  50 }
  51
  52 #define mask_and_ack_r4030_irq disable_r4030_irq
  53
  54 static void end_r4030_irq(unsigned int irq)
  55 {
  56         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
  57                 enable_r4030_irq(irq);
  58 }
  59
  60 static struct hw_interrupt_type r4030_irq_type = {
  61         .typename = "R4030",
  62         .startup = startup_r4030_irq,
  63         .shutdown = shutdown_r4030_irq,
  64         .enable = enable_r4030_irq,
  65         .disable = disable_r4030_irq,
  66         .ack = mask_and_ack_r4030_irq,
  67         .end = end_r4030_irq,
  68 };
  69
  70 void __init init_r4030_ints(void)
  71 {
  72         int i;
  73
  74         for (i = JAZZ_PARALLEL_IRQ; i <= JAZZ_TIMER_IRQ; i++) {
  75                 irq_desc[i].status     = IRQ_DISABLED;
  76                 irq_desc[i].action     = 0;
  77                 irq_desc[i].depth      = 1;
  78                 irq_desc[i].handler    = &r4030_irq_type;
  79         }
  80
  81         r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, 0);
  82         r4030_read_reg16(JAZZ_IO_IRQ_SOURCE);           /* clear pending IRQs */
  83         r4030_read_reg32(JAZZ_R4030_INVAL_ADDR);        /* clear error bits */
  84 }
  85
  86 /*
  87  * On systems with i8259-style interrupt controllers we assume for
  88  * driver compatibility reasons interrupts 0 - 15 to be the i8259
  89  * interrupts even if the hardware uses a different interrupt numbering.
  90  */
  91 void __init arch_init_irq(void)
  92 {
  93         set_except_vector(0, jazz_handle_int);
  94
  95         init_i8259_irqs();                      /* Integrated i8259  */
  96         init_r4030_ints();
  97
  98         change_c0_status(ST0_IM, IE_IRQ4 | IE_IRQ3 | IE_IRQ2 | IE_IRQ1);
  99 }