[mirror_ubuntu-focal-kernel.git] / arch / x86 / kernel / 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(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);

	return 0;
}

static int i8237A_suspend(struct sys_device *dev, pm_message_t state)
{
	return 0;
}

static struct sysdev_class i8237_sysdev_class = {
	.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);
Commit	Line	Data
795312e7	1	/*
835c34a1	2	* 8237A DMA controller suspend functions.
795312e7 PO	3	*
795312e7 PO	4	* Written by Pierre Ossman, 2005.
643f720c PO	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or (at
	9	* your option) any later version.
795312e7 PO	10	*/
	11
	12	#include <linux/init.h>
	13	#include <linux/sysdev.h>
	14
	15	#include <asm/dma.h>
	16
	17	/*
	18	* This module just handles suspend/resume issues with the
	19	* 8237A DMA controller (used for ISA and LPC).
	20	* Allocation is handled in kernel/dma.c and normal usage is
	21	* in asm/dma.h.
	22	*/
	23
	24	static int i8237A_resume(struct sys_device *dev)
	25	{
	26	unsigned long flags;
	27	int i;
	28
	29	flags = claim_dma_lock();
	30
b52af409 CL	31	dma_outb(0, DMA1_RESET_REG);
b52af409 CL	32	dma_outb(0, DMA2_RESET_REG);
795312e7	33
b52af409	34	for (i = 0; i < 8; i++) {
795312e7 PO	35	set_dma_addr(i, 0x000000);
	36	/* DMA count is a bit weird so this is not 0 */
	37	set_dma_count(i, 1);
	38	}
	39
	40	/* Enable cascade DMA or channel 0-3 won't work */
	41	enable_dma(4);
	42
	43	release_dma_lock(flags);
	44
	45	return 0;
	46	}
	47
	48	static int i8237A_suspend(struct sys_device *dev, pm_message_t state)
	49	{
	50	return 0;
	51	}
	52
	53	static struct sysdev_class i8237_sysdev_class = {
b52af409 CL	54	.name = "i8237",
	55	.suspend = i8237A_suspend,
	56	.resume = i8237A_resume,
795312e7 PO	57	};
	58
	59	static struct sys_device device_i8237A = {
b52af409 CL	60	.id = 0,
b52af409 CL	61	.cls = &i8237_sysdev_class,
795312e7 PO	62	};
	63
	64	static int __init i8237A_init_sysfs(void)
	65	{
	66	int error = sysdev_class_register(&i8237_sysdev_class);
	67	if (!error)
	68	error = sysdev_register(&device_i8237A);
	69	return error;
	70	}
795312e7	71	device_initcall(i8237A_init_sysfs);