/* * 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 */		local_irq_save(flags);		val = ctrl_inw((unsigned long)irq_mask_register);		val |= mask;		ctrl_outw(val, (unsigned long)irq_mask_register);		local_irq_restore(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 */		local_irq_save(flags);		val = ctrl_inw((unsigned long)irq_mask_register);		val &= mask;		ctrl_outw(val, (unsigned long)irq_mask_register);		local_irq_restore(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);}