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 <asm/system.h>
  15#include <linux/spinlock.h>
  16#include <asm/io.h>
  17#include <linux/delay.h>
  18
  19#undef MAX_DMA_CHANNELS         /* switch off linux/kernel/dma.c */
  20#define MAX_DMA_ADDRESS         0xbfffffff
  21
  22extern spinlock_t dma_spin_lock;
  23
  24static inline unsigned long claim_dma_lock(void)
  25{
  26        unsigned long flags;
  27        spin_lock_irqsave(&dma_spin_lock, flags);
  28        return flags;
  29}
  30
  31static inline void release_dma_lock(unsigned long flags)
  32{
  33        spin_unlock_irqrestore(&dma_spin_lock, flags);
  34}
  35
  36/* enable/disable a specific DMA channel */
  37static inline void enable_dma(unsigned int dmanr)
  38{
  39}
  40
  41static inline void disable_dma(unsigned int dmanr)
  42{
  43}
  44
  45/* Clear the 'DMA Pointer Flip Flop'.
  46 * Write 0 for LSB/MSB, 1 for MSB/LSB access.
  47 * Use this once to initialize the FF to a known state.
  48 * After that, keep track of it. :-)
  49 * --- In order to do that, the DMA routines below should ---
  50 * --- only be used while holding the DMA lock ! ---
  51 */
  52static inline void clear_dma_ff(unsigned int dmanr)
  53{
  54}
  55
  56/* set mode (above) for a specific DMA channel */
  57static inline void set_dma_mode(unsigned int dmanr, char mode)
  58{
  59}
  60
  61/* Set only the page register bits of the transfer address.
  62 * This is used for successive transfers when we know the contents of
  63 * the lower 16 bits of the DMA current address register, but a 64k boundary
  64 * may have been crossed.
  65 */
  66static inline void set_dma_page(unsigned int dmanr, char pagenr)
  67{
  68}
  69
  70
  71/* Set transfer address & page bits for specific DMA channel.
  72 * Assumes dma flipflop is clear.
  73 */
  74static inline void set_dma_addr(unsigned int dmanr, unsigned int a)
  75{
  76}
  77
  78
  79/* Set transfer size (max 64k for DMA1..3, 128k for DMA5..7) for
  80 * a specific DMA channel.
  81 * You must ensure the parameters are valid.
  82 * NOTE: from a manual: "the number of transfers is one more
  83 * than the initial word count"! This is taken into account.
  84 * Assumes dma flip-flop is clear.
  85 * NOTE 2: "count" represents _bytes_ and must be even for channels 5-7.
  86 */
  87static inline void set_dma_count(unsigned int dmanr, unsigned int count)
  88{
  89}
  90
  91
  92/* Get DMA residue count. After a DMA transfer, this
  93 * should return zero. Reading this while a DMA transfer is
  94 * still in progress will return unpredictable results.
  95 * If called before the channel has been used, it may return 1.
  96 * Otherwise, it returns the number of _bytes_ left to transfer.
  97 *
  98 * Assumes DMA flip-flop is clear.
  99 */
 100static inline int get_dma_residue(unsigned int dmanr)
 101{
 102        return 0;
 103}
 104
 105
 106/* These are in kernel/dma.c: */
 107extern int request_dma(unsigned int dmanr, const char *device_id);
 108extern void free_dma(unsigned int dmanr);
 109
 110/* From PCI */
 111
 112#ifdef CONFIG_PCI
 113extern int isa_dma_bridge_buggy;
 114#else
 115#define isa_dma_bridge_buggy    (0)
 116#endif
 117
 118#endif /* _ASM_DMA_H */
 119