blob: 098df2e617ab22b5eec54fb885106165f202166c [file] [log] [blame]
David Howellsb920de12008-02-08 04:19:31 -08001/* 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 */