Viewing file:  irq_maskreg.c (2.66 KB) -rw-r--r--
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/*
* linux/arch/sh/kernel/irq_maskreg.c
*
* Copyright (C) 2001 A&D Co., Ltd. <http://www.aandd.co.jp>
*
* This file may be copied or modified under the terms of the GNU
* General Public License. See linux/COPYING for more information.
*
* Interrupt handling for Simple external interrupt mask register
*
* This is for the machine which have single 16 bit register
* for masking external IRQ individually.
* Each bit of the register is for masking each interrupt.
*/
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/machvec.h>
/* address of external interrupt mask register
* address must be set prior to use these (maybe in init_XXX_irq())
* XXX : is it better to use .config than specifying it in code? */
unsigned short *irq_mask_register = 0;
/* forward declaration */
static unsigned int startup_maskreg_irq(unsigned int irq);
static void shutdown_maskreg_irq(unsigned int irq);
static void enable_maskreg_irq(unsigned int irq);
static void disable_maskreg_irq(unsigned int irq);
static void mask_and_ack_maskreg(unsigned int);
static void end_maskreg_irq(unsigned int irq);
/* hw_interrupt_type */
static struct hw_interrupt_type maskreg_irq_type = {
" Mask Register",
startup_maskreg_irq,
shutdown_maskreg_irq,
enable_maskreg_irq,
disable_maskreg_irq,
mask_and_ack_maskreg,
end_maskreg_irq
};
/* actual implementatin */
static unsigned int startup_maskreg_irq(unsigned int irq)
{
enable_maskreg_irq(irq);
return 0; /* never anything pending */
}
static void shutdown_maskreg_irq(unsigned int irq)
{
disable_maskreg_irq(irq);
}
static void disable_maskreg_irq(unsigned int irq)
{
if (irq_mask_register) {
unsigned long flags;
unsigned short val, mask = 0x01 << irq;
/* Set "irq"th bit */
save_and_cli(flags);
val = ctrl_inw((unsigned long)irq_mask_register);
val |= mask;
ctrl_outw(val, (unsigned long)irq_mask_register);
restore_flags(flags);
}
}
static void enable_maskreg_irq(unsigned int irq)
{
if (irq_mask_register) {
unsigned long flags;
unsigned short val, mask = ~(0x01 << irq);
/* Clear "irq"th bit */
save_and_cli(flags);
val = ctrl_inw((unsigned long)irq_mask_register);
val &= mask;
ctrl_outw(val, (unsigned long)irq_mask_register);
restore_flags(flags);
}
}
static void mask_and_ack_maskreg(unsigned int irq)
{
disable_maskreg_irq(irq);
}
static void end_maskreg_irq(unsigned int irq)
{
if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
enable_maskreg_irq(irq);
}
void make_maskreg_irq(unsigned int irq)
{
disable_irq_nosync(irq);
irq_desc[irq].handler = &maskreg_irq_type;
disable_maskreg_irq(irq);
}
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