mirror of https://gitee.com/openkylin/linux.git
56 lines
1.2 KiB
C
56 lines
1.2 KiB
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/syscore_ops.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 void i8237A_resume(void)
|
|
{
|
|
unsigned long flags;
|
|
int i;
|
|
|
|
flags = claim_dma_lock();
|
|
|
|
dma_outb(0, DMA1_RESET_REG);
|
|
dma_outb(0, DMA2_RESET_REG);
|
|
|
|
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);
|
|
}
|
|
|
|
static struct syscore_ops i8237_syscore_ops = {
|
|
.resume = i8237A_resume,
|
|
};
|
|
|
|
static int __init i8237A_init_ops(void)
|
|
{
|
|
register_syscore_ops(&i8237_syscore_ops);
|
|
return 0;
|
|
}
|
|
device_initcall(i8237A_init_ops);
|