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
 26extern unsigned long *interrupt_redirect_table;
 27extern const int h8300_saved_vectors[];
 28extern const h8300_vector h8300_trap_table[];
 29int h8300_enable_irq_pin(unsigned int irq);
 30void h8300_disable_irq_pin(unsigned int irq);
 31
 32#define CPU_VECTOR ((unsigned long *)0x000000)
 33#define ADDR_MASK (0xffffff)
 34
 35static inline int is_ext_irq(unsigned int irq)
 36{
 37	return (irq >= EXT_IRQ0 && irq <= (EXT_IRQ0 + EXT_IRQS));
 38}
 39
 40static 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
 46static 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
 52static 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
 60static 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 */
 69struct 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)
 78static 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
103static 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
150void __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
160asmlinkage void do_IRQ(int irq)
161{
162	irq_enter();
163	generic_handle_irq(irq);
164	irq_exit();
165}