/* linux/arch/arm/mach-s3c2410/bast-irq.c
   *
   * Copyright 2003-2005 Simtec Electronics
   *   Ben Dooks <ben@simtec.co.uk>
   *
   * http://www.simtec.co.uk/products/EB2410ITX/
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
  
  
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/ioport.h>
  #include <linux/device.h>
  #include <linux/io.h>
  
  #include <asm/irq.h>
  #include <asm/mach-types.h>
  #include <asm/mach/irq.h>
  
  #include <mach/hardware.h>
  #include <mach/regs-irq.h>
  
  #include "bast.h"
  
  #define irqdbf(x...)
  #define irqdbf2(x...)
  
  /* handle PC104 ISA interrupts from the system CPLD */
  
  /* table of ISA irq nos to the relevant mask... zero means
   * the irq is not implemented
  */
  static unsigned char bast_pc104_irqmasks[] = {
  	0,   /* 0 */
  	0,   /* 1 */
  	0,   /* 2 */
  	1,   /* 3 */
  	0,   /* 4 */
  	2,   /* 5 */
  	0,   /* 6 */
  	4,   /* 7 */
  	0,   /* 8 */
  	0,   /* 9 */
  	8,   /* 10 */
  	0,   /* 11 */
  	0,   /* 12 */
  	0,   /* 13 */
  	0,   /* 14 */
  	0,   /* 15 */
  };
  
  static unsigned char bast_pc104_irqs[] = { 3, 5, 7, 10 };
  
  static void
  bast_pc104_mask(struct irq_data *data)
  {
  	unsigned long temp;
  
  	temp = __raw_readb(BAST_VA_PC104_IRQMASK);
  	temp &= ~bast_pc104_irqmasks[data->irq];
  	__raw_writeb(temp, BAST_VA_PC104_IRQMASK);
  }
  
  static void
  bast_pc104_maskack(struct irq_data *data)
  {
  	struct irq_desc *desc = irq_desc + BAST_IRQ_ISA;
  
  	bast_pc104_mask(data);
  	desc->irq_data.chip->irq_ack(&desc->irq_data);
  }
  
  static void
  bast_pc104_unmask(struct irq_data *data)
  {
  	unsigned long temp;
  
  	temp = __raw_readb(BAST_VA_PC104_IRQMASK);
  	temp |= bast_pc104_irqmasks[data->irq];
  	__raw_writeb(temp, BAST_VA_PC104_IRQMASK);
  }
  
  static struct irq_chip  bast_pc104_chip = {
  	.irq_mask	= bast_pc104_mask,
  	.irq_unmask	= bast_pc104_unmask,
  	.irq_ack	= bast_pc104_maskack
  };
  
  static void
  bast_irq_pc104_demux(unsigned int irq,
  		     struct irq_desc *desc)
  {
  	unsigned int stat;
  	unsigned int irqno;
  	int i;
  
  	stat = __raw_readb(BAST_VA_PC104_IRQREQ) & 0xf;
  
  	if (unlikely(stat == 0)) {
  		/* ack if we get an irq with nothing (ie, startup) */
  
  		desc = irq_desc + BAST_IRQ_ISA;
  		desc->irq_data.chip->irq_ack(&desc->irq_data);
  	} else {
  		/* handle the IRQ */
  
  		for (i = 0; stat != 0; i++, stat >>= 1) {
  			if (stat & 1) {
  				irqno = bast_pc104_irqs[i];
  				generic_handle_irq(irqno);
  			}
  		}
  	}
  }
  
  static __init int bast_irq_init(void)
  {
  	unsigned int i;
  
  	if (machine_is_bast()) {
  		printk(KERN_INFO "BAST PC104 IRQ routing, Copyright 2005 Simtec Electronics
  ");
  
  		/* zap all the IRQs */
  
  		__raw_writeb(0x0, BAST_VA_PC104_IRQMASK);
  
  		irq_set_chained_handler(BAST_IRQ_ISA, bast_irq_pc104_demux);
  
  		/* register our IRQs */
  
  		for (i = 0; i < 4; i++) {
  			unsigned int irqno = bast_pc104_irqs[i];
  
  			irq_set_chip_and_handler(irqno, &bast_pc104_chip,
  						 handle_level_irq);
  			set_irq_flags(irqno, IRQF_VALID);
  		}
  	}
  
  	return 0;
  }
  
  arch_initcall(bast_irq_init);