[net-next-2.6.git] / arch / alpha / kernel / ns87312.c

/*
 *	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);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/alpha/kernel/ns87312.c
	3	*/
	4
	5	#include <linux/init.h>
	6	#include <asm/io.h>
	7	#include "proto.h"
	8
	9
	10	/*
	11	* The SRM console disables the IDE interface, this code ensures it's
	12	* enabled.
	13	*
	14	* This code bangs on a control register of the 87312 Super I/O chip
	15	* that implements parallel port/serial ports/IDE/FDI. Depending on
	16	* the motherboard, the Super I/O chip can be configured through a
	17	* pair of registers that are located either at I/O ports 0x26e/0x26f
	18	* or 0x398/0x399. Unfortunately, autodetecting which base address is
	19	* in use works only once (right after a reset). The Super I/O chip
	20	* has the additional quirk that configuration register data must be
	21	* written twice (I believe this is a safety feature to prevent
	22	* accidental modification---fun, isn't it?).
	23	*/
	24
	25	void __init
	26	ns87312_enable_ide(long ide_base)
	27	{
	28	int data;
	29	unsigned long flags;
	30
	31	local_irq_save(flags);
	32	outb(0, ide_base); /* set the index register for reg #0 */
	33	data = inb(ide_base+1); /* read the current contents */
	34	outb(0, ide_base); /* set the index register for reg #0 */
	35	outb(data \| 0x40, ide_base+1); /* turn on IDE */
	36	outb(data \| 0x40, ide_base+1); /* turn on IDE, really! */
	37	local_irq_restore(flags);
	38	}