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/*
* i8237.c: 8237A DMA controller suspend functions.
*
* Written by Pierre Ossman, 2005.
*
* 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.
*/
#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);
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