projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 795312e7 PO |
1 | /* |
| 2 | * i8237.c: 8237A DMA controller suspend functions. | |
| 3 | * | |
| 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 | ||
| 31 | dma_outb(DMA1_RESET_REG, 0); | |
| 32 | dma_outb(DMA2_RESET_REG, 0); | |
| 33 | ||
| 34 | for (i = 0;i < 8;i++) { | |
| 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 = { | |
| 54 | set_kset_name("i8237"), | |
| 55 | .suspend = i8237A_suspend, | |
| 56 | .resume = i8237A_resume, | |
| 57 | }; | |
| 58 | ||
| 59 | static struct sys_device device_i8237A = { | |
| 60 | .id = 0, | |
| 61 | .cls = &i8237_sysdev_class, | |
| 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 | } | |
| 71 | ||
| 72 | device_initcall(i8237A_init_sysfs); |