/* Copyright (C) 2004  The KOS Team
 
    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 "ioports.h"
 
 #include "i8259.h"
 
 #define PIC_MASTER 0x20
 #define PIC_SLAVE  0xa0
 
 /** Setup the 8259 PIC */
 sos_ret_t sos_i8259_subsystem_setup(void)
 {
   /* Send ICW1: 8086 mode + NOT Single ctrl + call address
      interval=8 */
   outb(0x11, PIC_MASTER);
   outb(0x11, PIC_SLAVE);
 
   /* Send ICW2: ctrl base address */
   outb(0x20, PIC_MASTER+1);
   outb(0x28, PIC_SLAVE+1);
 
   /* Send ICW3 master: mask where slaves are connected */
   outb(0x4, PIC_MASTER+1);
   /* Send ICW3 slave: index where the slave is connected on master */
   outb(0x2, PIC_SLAVE+1);
 
   /* Send ICW4: 8086 mode, fully nested, not buffered, no implicit EOI */
   outb(0x1, PIC_MASTER+1);
   outb(0x1, PIC_SLAVE+1);
 
   /* Send OCW1:
    * Closing all IRQs : waiting for a correct handler The only IRQ
    * enabled is the cascade (that's why we use 0xFB for the master) */
   outb(0xFB, PIC_MASTER+1);
   outb(0xFF, PIC_SLAVE+1);
 
   return SOS_OK;
 }
 
 
 sos_ret_t sos_i8259_enable_irq_line(int numirq)
 {
   if(numirq < 8)
     /*  irq on master PIC */
     outb((inb(PIC_MASTER+1) & ~(1 << numirq)), PIC_MASTER+1);
   else
     /*  irq on slave PIC */
     outb((inb(PIC_SLAVE+1) & ~(1 << (numirq-8))), PIC_SLAVE+1);
   
   return SOS_OK;
 }
 
 
 sos_ret_t sos_i8259_disable_irq_line(int numirq)
 {
   if(numirq < 8)
     /*  irq on master PIC */
     outb((inb(PIC_MASTER+1) | (1 << numirq)), PIC_MASTER+1);
   else
     /*  irq on slave PIC */
     outb((inb(PIC_SLAVE+1) | (1 << (numirq-8))), PIC_SLAVE+1);
 
   return SOS_OK;
 }