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/arch/mn10300/include/asm/dma.h

http://github.com/mirrors/linux
C++ Header | 117 lines | 51 code | 21 blank | 45 comment | 0 complexity | e55fe3707fd9ee7b614f3d271fe79020 MD5 | raw file
  1/* MN10300 ISA DMA handlers and definitions
  2 *
  3 * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
  4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
  5 *
  6 * This program is free software; you can redistribute it and/or
  7 * modify it under the terms of the GNU General Public Licence
  8 * as published by the Free Software Foundation; either version
  9 * 2 of the Licence, or (at your option) any later version.
 10 */
 11#ifndef _ASM_DMA_H
 12#define _ASM_DMA_H
 13
 14#include <linux/spinlock.h>
 15#include <asm/io.h>
 16#include <linux/delay.h>
 17
 18#undef MAX_DMA_CHANNELS		/* switch off linux/kernel/dma.c */
 19#define MAX_DMA_ADDRESS		0xbfffffff
 20
 21extern spinlock_t dma_spin_lock;
 22
 23static inline unsigned long claim_dma_lock(void)
 24{
 25	unsigned long flags;
 26	spin_lock_irqsave(&dma_spin_lock, flags);
 27	return flags;
 28}
 29
 30static inline void release_dma_lock(unsigned long flags)
 31{
 32	spin_unlock_irqrestore(&dma_spin_lock, flags);
 33}
 34
 35/* enable/disable a specific DMA channel */
 36static inline void enable_dma(unsigned int dmanr)
 37{
 38}
 39
 40static inline void disable_dma(unsigned int dmanr)
 41{
 42}
 43
 44/* Clear the 'DMA Pointer Flip Flop'.
 45 * Write 0 for LSB/MSB, 1 for MSB/LSB access.
 46 * Use this once to initialize the FF to a known state.
 47 * After that, keep track of it. :-)
 48 * --- In order to do that, the DMA routines below should ---
 49 * --- only be used while holding the DMA lock ! ---
 50 */
 51static inline void clear_dma_ff(unsigned int dmanr)
 52{
 53}
 54
 55/* set mode (above) for a specific DMA channel */
 56static inline void set_dma_mode(unsigned int dmanr, char mode)
 57{
 58}
 59
 60/* Set only the page register bits of the transfer address.
 61 * This is used for successive transfers when we know the contents of
 62 * the lower 16 bits of the DMA current address register, but a 64k boundary
 63 * may have been crossed.
 64 */
 65static inline void set_dma_page(unsigned int dmanr, char pagenr)
 66{
 67}
 68
 69
 70/* Set transfer address & page bits for specific DMA channel.
 71 * Assumes dma flipflop is clear.
 72 */
 73static inline void set_dma_addr(unsigned int dmanr, unsigned int a)
 74{
 75}
 76
 77
 78/* Set transfer size (max 64k for DMA1..3, 128k for DMA5..7) for
 79 * a specific DMA channel.
 80 * You must ensure the parameters are valid.
 81 * NOTE: from a manual: "the number of transfers is one more
 82 * than the initial word count"! This is taken into account.
 83 * Assumes dma flip-flop is clear.
 84 * NOTE 2: "count" represents _bytes_ and must be even for channels 5-7.
 85 */
 86static inline void set_dma_count(unsigned int dmanr, unsigned int count)
 87{
 88}
 89
 90
 91/* Get DMA residue count. After a DMA transfer, this
 92 * should return zero. Reading this while a DMA transfer is
 93 * still in progress will return unpredictable results.
 94 * If called before the channel has been used, it may return 1.
 95 * Otherwise, it returns the number of _bytes_ left to transfer.
 96 *
 97 * Assumes DMA flip-flop is clear.
 98 */
 99static inline int get_dma_residue(unsigned int dmanr)
100{
101	return 0;
102}
103
104
105/* These are in kernel/dma.c: */
106extern int request_dma(unsigned int dmanr, const char *device_id);
107extern void free_dma(unsigned int dmanr);
108
109/* From PCI */
110
111#ifdef CONFIG_PCI
112extern int isa_dma_bridge_buggy;
113#else
114#define isa_dma_bridge_buggy 	(0)
115#endif
116
117#endif /* _ASM_DMA_H */