[PATCH] ISA DMA suspend for i386

obj-y	:= process.o semaphore.o signal.o entry.o traps.o irq.o vm86.o \

		ptrace.o time.o ioport.o ldt.o setup.o i8259.o sys_i386.o \

		pci-dma.o i386_ksyms.o i387.o dmi_scan.o bootflag.o \

		doublefault.o quirks.o

		doublefault.o quirks.o i8237.o

obj-y				+= cpu/

obj-y				+= timers/

/*

 * i8237.c: 8237A DMA controller suspend functions.

 *

 * Written by Pierre Ossman, 2005.

 */

#include <linux/init.h>

#include <linux/sysdev.h>

#include <asm/dma.h>

/*

 * This module just handles suspend/resume issues with the

 * 8237A DMA controller (used for ISA and LPC).

 * Allocation is handled in kernel/dma.c and normal usage is

 * in asm/dma.h.

 */

static int i8237A_resume(struct sys_device *dev)

{

	unsigned long flags;

	int i;

	flags = claim_dma_lock();

	dma_outb(DMA1_RESET_REG, 0);

	dma_outb(DMA2_RESET_REG, 0);

	for (i = 0;i < 8;i++) {

		set_dma_addr(i, 0x000000);

		/* DMA count is a bit weird so this is not 0 */

		set_dma_count(i, 1);

	}

	/* Enable cascade DMA or channel 0-3 won't work */

	enable_dma(4);

	release_dma_lock(flags);

	return 0;

}

static int i8237A_suspend(struct sys_device *dev, pm_message_t state)

{

	return 0;

}

static struct sysdev_class i8237_sysdev_class = {

	set_kset_name("i8237"),

	.suspend = i8237A_suspend,

	.resume = i8237A_resume,

};

static struct sys_device device_i8237A = {

	.id	= 0,

	.cls	= &i8237_sysdev_class,

};

static int __init i8237A_init_sysfs(void)

{

	int error = sysdev_class_register(&i8237_sysdev_class);

	if (!error)

		error = sysdev_register(&device_i8237A);

	return error;

}

device_initcall(i8237A_init_sysfs);