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

   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 */
 118