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/system.h>
  20 #include <asm/traps.h>
  21 #include <asm/io.h>
  22 #include <asm/setup.h>
  23 #include <asm/errno.h>
  24
  25 /*#define DEBUG*/
  26
  27 extern unsigned long *interrupt_redirect_table;
  28 extern const int h8300_saved_vectors[];
  29 extern const h8300_vector h8300_trap_table[];
  30 int h8300_enable_irq_pin(unsigned int irq);
  31 void h8300_disable_irq_pin(unsigned int irq);
  32
  33 #define CPU_VECTOR ((unsigned long *)0x000000)
  34 #define ADDR_MASK (0xffffff)
  35
  36 static inline int is_ext_irq(unsigned int irq)
  37 {
  38         return (irq >= EXT_IRQ0 && irq <= (EXT_IRQ0 + EXT_IRQS));
  39 }
  40
  41 static void h8300_enable_irq(struct irq_data *data)
  42 {
  43         if (is_ext_irq(data->irq))
  44                 IER_REGS |= 1 << (data->irq - EXT_IRQ0);
  45 }
  46
  47 static void h8300_disable_irq(struct irq_data *data)
  48 {
  49         if (is_ext_irq(data->irq))
  50                 IER_REGS &= ~(1 << (data->irq - EXT_IRQ0));
  51 }
  52
  53 static unsigned int h8300_startup_irq(struct irq_data *data)
  54 {
  55         if (is_ext_irq(data->irq))
  56                 return h8300_enable_irq_pin(data->irq);
  57         else
  58                 return 0;
  59 }
  60
  61 static void h8300_shutdown_irq(struct irq_data *data)
  62 {
  63         if (is_ext_irq(data->irq))
  64                 h8300_disable_irq_pin(data->irq);
  65 }
  66
  67 /*
  68  * h8300 interrupt controller implementation
  69  */
  70 struct irq_chip h8300irq_chip = {
  71         .name           = "H8300-INTC",
  72         .irq_startup    = h8300_startup_irq,
  73         .irq_shutdown   = h8300_shutdown_irq,
  74         .irq_enable     = h8300_enable_irq,
  75         .irq_disable    = h8300_disable_irq,
  76 };
  77
  78 #if defined(CONFIG_RAMKERNEL)
  79 static unsigned long __init *get_vector_address(void)
  80 {
  81         unsigned long *rom_vector = CPU_VECTOR;
  82         unsigned long base,tmp;
  83         int vec_no;
  84
  85         base = rom_vector[EXT_IRQ0] & ADDR_MASK;
  86
  87         /* check romvector format */
  88         for (vec_no = EXT_IRQ1; vec_no <= EXT_IRQ0+EXT_IRQS; vec_no++) {
  89                 if ((base+(vec_no - EXT_IRQ0)*4) != (rom_vector[vec_no] & ADDR_MASK))
  90                         return NULL;
  91         }
  92
  93         /* ramvector base address */
  94         base -= EXT_IRQ0*4;
  95
  96         /* writerble check */
  97         tmp = ~(*(volatile unsigned long *)base);
  98         (*(volatile unsigned long *)base) = tmp;
  99         if ((*(volatile unsigned long *)base) != tmp)
 100                 return NULL;
 101         return (unsigned long *)base;
 102 }
 103
 104 static void __init setup_vector(void)
 105 {
 106         int i;
 107         unsigned long *ramvec,*ramvec_p;
 108         const h8300_vector *trap_entry;
 109         const int *saved_vector;
 110
 111         ramvec = get_vector_address();
 112         if (ramvec == NULL)
 113                 panic("interrupt vector serup failed.");
 114         else
 115                 printk(KERN_INFO "virtual vector at 0x%08lx\n",(unsigned long)ramvec);
 116
 117         /* create redirect table */
 118         ramvec_p = ramvec;
 119         trap_entry = h8300_trap_table;
 120         saved_vector = h8300_saved_vectors;
 121         for ( i = 0; i < NR_IRQS; i++) {
 122                 if (i == *saved_vector) {
 123                         ramvec_p++;
 124                         saved_vector++;
 125                 } else {
 126                         if ( i < NR_TRAPS ) {
 127                                 if (*trap_entry)
 128                                         *ramvec_p = VECTOR(*trap_entry);
 129                                 ramvec_p++;
 130                                 trap_entry++;
 131                         } else
 132                                 *ramvec_p++ = REDIRECT(interrupt_entry);
 133                 }
 134         }
 135         interrupt_redirect_table = ramvec;
 136 #ifdef DEBUG
 137         ramvec_p = ramvec;
 138         for (i = 0; i < NR_IRQS; i++) {
 139                 if ((i % 8) == 0)
 140                         printk(KERN_DEBUG "\n%p: ",ramvec_p);
 141                 printk(KERN_DEBUG "%p ",*ramvec_p);
 142                 ramvec_p++;
 143         }
 144         printk(KERN_DEBUG "\n");
 145 #endif
 146 }
 147 #else
 148 #define setup_vector() do { } while(0)
 149 #endif
 150
 151 void __init init_IRQ(void)
 152 {
 153         int c;
 154
 155         setup_vector();
 156
 157         for (c = 0; c < NR_IRQS; c++)
 158                 irq_set_chip_and_handler(c, &h8300irq_chip, handle_simple_irq);
 159 }
 160
 161 asmlinkage void do_IRQ(int irq)
 162 {
 163         irq_enter();
 164         generic_handle_irq(irq);
 165         irq_exit();
 166 }