arch/h8300/kernel/irq.c

   1 /*
   2  * linux/arch/h8300/kernel/irq.c
   3  *
   4  * Copyright 2007 Yoshinori Sato <ysato@users.sourceforge.jp>
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/types.h>
   9 #include <linux/kernel.h>
  10 #include <linux/sched.h>
  11 #include <linux/kernel_stat.h>
  12 #include <linux/seq_file.h>
  13 #include <linux/init.h>
  14 #include <linux/random.h>
  15 #include <linux/bootmem.h>
  16 #include <linux/irq.h>
  17 #include <linux/interrupt.h>
  18
  19 #include <asm/traps.h>
  20 #include <asm/io.h>
  21 #include <asm/setup.h>
  22 #include <asm/errno.h>
  23
  24 /*#define DEBUG*/
  25
  26 extern unsigned long *interrupt_redirect_table;
  27 extern const int h8300_saved_vectors[];
  28 extern const h8300_vector h8300_trap_table[];
  29 int h8300_enable_irq_pin(unsigned int irq);
  30 void h8300_disable_irq_pin(unsigned int irq);
  31
  32 #define CPU_VECTOR ((unsigned long *)0x000000)
  33 #define ADDR_MASK (0xffffff)
  34
  35 static inline int is_ext_irq(unsigned int irq)
  36 {
  37         return (irq >= EXT_IRQ0 && irq <= (EXT_IRQ0 + EXT_IRQS));
  38 }
  39
  40 static void h8300_enable_irq(struct irq_data *data)
  41 {
  42         if (is_ext_irq(data->irq))
  43                 IER_REGS |= 1 << (data->irq - EXT_IRQ0);
  44 }
  45
  46 static void h8300_disable_irq(struct irq_data *data)
  47 {
  48         if (is_ext_irq(data->irq))
  49                 IER_REGS &= ~(1 << (data->irq - EXT_IRQ0));
  50 }
  51
  52 static unsigned int h8300_startup_irq(struct irq_data *data)
  53 {
  54         if (is_ext_irq(data->irq))
  55                 return h8300_enable_irq_pin(data->irq);
  56         else
  57                 return 0;
  58 }
  59
  60 static void h8300_shutdown_irq(struct irq_data *data)
  61 {
  62         if (is_ext_irq(data->irq))
  63                 h8300_disable_irq_pin(data->irq);
  64 }
  65
  66 /*
  67  * h8300 interrupt controller implementation
  68  */
  69 struct irq_chip h8300irq_chip = {
  70         .name           = "H8300-INTC",
  71         .irq_startup    = h8300_startup_irq,
  72         .irq_shutdown   = h8300_shutdown_irq,
  73         .irq_enable     = h8300_enable_irq,
  74         .irq_disable    = h8300_disable_irq,
  75 };
  76
  77 #if defined(CONFIG_RAMKERNEL)
  78 static unsigned long __init *get_vector_address(void)
  79 {
  80         unsigned long *rom_vector = CPU_VECTOR;
  81         unsigned long base,tmp;
  82         int vec_no;
  83
  84         base = rom_vector[EXT_IRQ0] & ADDR_MASK;
  85
  86         /* check romvector format */
  87         for (vec_no = EXT_IRQ1; vec_no <= EXT_IRQ0+EXT_IRQS; vec_no++) {
  88                 if ((base+(vec_no - EXT_IRQ0)*4) != (rom_vector[vec_no] & ADDR_MASK))
  89                         return NULL;
  90         }
  91
  92         /* ramvector base address */
  93         base -= EXT_IRQ0*4;
  94
  95         /* writerble check */
  96         tmp = ~(*(volatile unsigned long *)base);
  97         (*(volatile unsigned long *)base) = tmp;
  98         if ((*(volatile unsigned long *)base) != tmp)
  99                 return NULL;
 100         return (unsigned long *)base;
 101 }
 102
 103 static void __init setup_vector(void)
 104 {
 105         int i;
 106         unsigned long *ramvec,*ramvec_p;
 107         const h8300_vector *trap_entry;
 108         const int *saved_vector;
 109
 110         ramvec = get_vector_address();
 111         if (ramvec == NULL)
 112                 panic("interrupt vector serup failed.");
 113         else
 114                 printk(KERN_INFO "virtual vector at 0x%08lx\n",(unsigned long)ramvec);
 115
 116         /* create redirect table */
 117         ramvec_p = ramvec;
 118         trap_entry = h8300_trap_table;
 119         saved_vector = h8300_saved_vectors;
 120         for ( i = 0; i < NR_IRQS; i++) {
 121                 if (i == *saved_vector) {
 122                         ramvec_p++;
 123                         saved_vector++;
 124                 } else {
 125                         if ( i < NR_TRAPS ) {
 126                                 if (*trap_entry)
 127                                         *ramvec_p = VECTOR(*trap_entry);
 128                                 ramvec_p++;
 129                                 trap_entry++;
 130                         } else
 131                                 *ramvec_p++ = REDIRECT(interrupt_entry);
 132                 }
 133         }
 134         interrupt_redirect_table = ramvec;
 135 #ifdef DEBUG
 136         ramvec_p = ramvec;
 137         for (i = 0; i < NR_IRQS; i++) {
 138                 if ((i % 8) == 0)
 139                         printk(KERN_DEBUG "\n%p: ",ramvec_p);
 140                 printk(KERN_DEBUG "%p ",*ramvec_p);
 141                 ramvec_p++;
 142         }
 143         printk(KERN_DEBUG "\n");
 144 #endif
 145 }
 146 #else
 147 #define setup_vector() do { } while(0)
 148 #endif
 149
 150 void __init init_IRQ(void)
 151 {
 152         int c;
 153
 154         setup_vector();
 155
 156         for (c = 0; c < NR_IRQS; c++)
 157                 irq_set_chip_and_handler(c, &h8300irq_chip, handle_simple_irq);
 158 }
 159
 160 asmlinkage void do_IRQ(int irq)
 161 {
 162         irq_enter();
 163         generic_handle_irq(irq);
 164         irq_exit();
 165 }