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