projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 9a8fd558 CZ |
1 | /* |
| 2 | * include/asm-xtensa/dma.h | |
| 3 | * | |
| 4 | * This file is subject to the terms and conditions of the GNU General Public | |
| 5 | * License. See the file "COPYING" in the main directory of this archive | |
| 6 | * for more details. | |
| 7 | * | |
| 8 | * Copyright (C) 2003 - 2005 Tensilica Inc. | |
| 9 | */ | |
| 10 | ||
| 11 | #ifndef _XTENSA_DMA_H | |
| 12 | #define _XTENSA_DMA_H | |
| 13 | ||
| 14 | #include <linux/config.h> | |
| 15 | #include <asm/io.h> /* need byte IO */ | |
| 16 | #include <xtensa/config/core.h> | |
| 17 | ||
| 18 | /* | |
| 19 | * This is only to be defined if we have PC-like DMA. | |
| 20 | * By default this is not true on an Xtensa processor, | |
| 21 | * however on boards with a PCI bus, such functionality | |
| 22 | * might be emulated externally. | |
| 23 | * | |
| 24 | * NOTE: there still exists driver code that assumes | |
| 25 | * this is defined, eg. drivers/sound/soundcard.c (as of 2.4). | |
| 26 | */ | |
| 27 | #define MAX_DMA_CHANNELS 8 | |
| 28 | ||
| 29 | /* | |
| 30 | * The maximum virtual address to which DMA transfers | |
| 31 | * can be performed on this platform. | |
| 32 | * | |
| 33 | * NOTE: This is board (platform) specific, not processor-specific! | |
| 34 | * | |
| 35 | * NOTE: This assumes DMA transfers can only be performed on | |
| 36 | * the section of physical memory contiguously mapped in virtual | |
| 37 | * space for the kernel. For the Xtensa architecture, this | |
| 38 | * means the maximum possible size of this DMA area is | |
| 39 | * the size of the statically mapped kernel segment | |
| 40 | * (XCHAL_KSEG_{CACHED,BYPASS}_SIZE), ie. 128 MB. | |
| 41 | * | |
| 42 | * NOTE: When the entire KSEG area is DMA capable, we substract | |
| 43 | * one from the max address so that the virt_to_phys() macro | |
| 44 | * works correctly on the address (otherwise the address | |
| 45 | * enters another area, and virt_to_phys() may not return | |
| 46 | * the value desired). | |
| 47 | */ | |
| 48 | #define MAX_DMA_ADDRESS (PAGE_OFFSET + XCHAL_KSEG_CACHED_SIZE - 1) | |
| 49 | ||
| 50 | /* Reserve and release a DMA channel */ | |
| 51 | extern int request_dma(unsigned int dmanr, const char * device_id); | |
| 52 | extern void free_dma(unsigned int dmanr); | |
| 53 | ||
| 54 | #ifdef CONFIG_PCI | |
| 55 | extern int isa_dma_bridge_buggy; | |
| 56 | #else | |
| 57 | #define isa_dma_bridge_buggy (0) | |
| 58 | #endif | |
| 59 | ||
| 60 | ||
| 61 | #endif |