/* * 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 = { .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);