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