1 /* 1
2 * include/asm-xtensa/dma.h
3 *
4 * This file is subject to the terms and condi
5 * License. See the file "COPYING" in the mai
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 <asm/io.h> /* need byte I
15
16 /*
17 * This is only to be defined if we have PC-li
18 * By default this is not true on an Xtensa pr
19 * however on boards with a PCI bus, such func
20 * might be emulated externally.
21 *
22 * NOTE: there still exists driver code that
23 * this is defined, eg. drivers/sound/soundcar
24 */
25 #define MAX_DMA_CHANNELS 8
26
27 /*
28 * The maximum virtual address to which DMA tr
29 * can be performed on this platform.
30 *
31 * NOTE: This is board (platform) specific, no
32 *
33 * NOTE: This assumes DMA transfers can only b
34 * the section of physical memory contigu
35 * space for the kernel. For the Xtensa
36 * means the maximum possible size of thi
37 * the size of the statically mapped kern
38 * (XCHAL_KSEG_{CACHED,BYPASS}_SIZE), ie.
39 *
40 * NOTE: When the entire KSEG area is DMA capa
41 * one from the max address so that the v
42 * works correctly on the address (otherw
43 * enters another area, and virt_to_phys(
44 * the value desired).
45 */
46
47 #ifndef MAX_DMA_ADDRESS
48 #define MAX_DMA_ADDRESS (PAGE_OFFSET +
49 #endif
50
51 /* Reserve and release a DMA channel */
52 extern int request_dma(unsigned int dmanr, con
53 extern void free_dma(unsigned int dmanr);
54
55 #endif
56
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