include/asm-mn10300/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
  22 extern spinlock_t dma_spin_lock;
  23
  24 static 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
  31 static 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 */
  37 static inline void enable_dma(unsigned int dmanr)
  38 {
  39 }
  40
  41 static 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  */
  52 static inline void clear_dma_ff(unsigned int dmanr)
  53 {
  54 }
  55
  56 /* set mode (above) for a specific DMA channel */
  57 static 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  */
  66 static 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  */
  74 static 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  */
  87 static 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  */
 100 static inline int get_dma_residue(unsigned int dmanr)
 101 {
 102         return 0;
 103 }
 104
 105
 106 /* These are in kernel/dma.c: */
 107 extern int request_dma(unsigned int dmanr, const char *device_id);
 108 extern void free_dma(unsigned int dmanr);
 109
 110 /* From PCI */
 111
 112 #ifdef CONFIG_PCI
 113 extern int isa_dma_bridge_buggy;
 114 #else
 115 #define isa_dma_bridge_buggy    (0)
 116 #endif
 117
 118 #endif /* _ASM_DMA_H */