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Diffstat (limited to 'include/asm-xtensa/dma.h')
-rw-r--r-- | include/asm-xtensa/dma.h | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/include/asm-xtensa/dma.h b/include/asm-xtensa/dma.h new file mode 100644 index 000000000000..1c22b0234586 --- /dev/null +++ b/include/asm-xtensa/dma.h | |||
@@ -0,0 +1,61 @@ | |||
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 | ||