Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 *      linux/arch/alpha/kernel/ns87312.c

 */

#include <linux/init.h>

#include <asm/io.h>

#include "proto.h"

/*

 * The SRM console *disables* the IDE interface, this code ensures it's

 * enabled.

 *

 * This code bangs on a control register of the 87312 Super I/O chip

 * that implements parallel port/serial ports/IDE/FDI.  Depending on

 * the motherboard, the Super I/O chip can be configured through a

 * pair of registers that are located either at I/O ports 0x26e/0x26f

 * or 0x398/0x399.  Unfortunately, autodetecting which base address is

 * in use works only once (right after a reset).  The Super I/O chip

 * has the additional quirk that configuration register data must be

 * written twice (I believe this is a safety feature to prevent

 * accidental modification---fun, isn't it?).

 */

void __init

ns87312_enable_ide(long ide_base)

{

        int data;

        unsigned long flags;

        local_irq_save(flags);

        outb(0, ide_base);               /* set the index register for reg #0 */

        data = inb(ide_base+1);         /* read the current contents */

        outb(0, ide_base);               /* set the index register for reg #0 */

        outb(data | 0x40, ide_base+1);  /* turn on IDE */

        outb(data | 0x40, ide_base+1);  /* turn on IDE, really! */

        local_irq_restore(flags);

}