1/*
2 * arch/sh/drivers/dma/dma-isa.c
3 *
4 * Generic ISA DMA wrapper for SH DMA API
5 *
6 * Copyright (C) 2003, 2004  Paul Mundt
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License.  See the file "COPYING" in the main directory of this archive
10 * for more details.
11 */
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <asm/dma.h>
15
16/*
17 * This implements a small wrapper set to make code using the old ISA DMA API
18 * work with the SH DMA API. Since most of the work in the new API happens
19 * at ops->xfer() time, we simply use the various set_dma_xxx() routines to
20 * fill in per-channel info, and then hand hand this off to ops->xfer() at
21 * enable_dma() time.
22 *
23 * For channels that are doing on-demand data transfer via cascading, the
24 * channel itself will still need to be configured through the new API. As
25 * such, this code is meant for only the simplest of tasks (and shouldn't be
26 * used in any new drivers at all).
27 *
28 * NOTE: ops->xfer() is the preferred way of doing things. However, there
29 * are some users of the ISA DMA API that exist in common code that we
30 * don't necessarily want to go out of our way to break, so we still
31 * allow for some compatibility at that level. Any new code is strongly
32 * advised to run far away from the ISA DMA API and use the SH DMA API
33 * directly.
34 */
35unsigned long claim_dma_lock(void)
36{
37	unsigned long flags;
38
39	spin_lock_irqsave(&dma_spin_lock, flags);
40
41	return flags;
42}
43EXPORT_SYMBOL(claim_dma_lock);
44
45void release_dma_lock(unsigned long flags)
46{
47	spin_unlock_irqrestore(&dma_spin_lock, flags);
48}
49EXPORT_SYMBOL(release_dma_lock);
50
51void disable_dma(unsigned int chan)
52{
53	/* Nothing */
54}
55EXPORT_SYMBOL(disable_dma);
56
57void enable_dma(unsigned int chan)
58{
59	struct dma_info *info = get_dma_info(chan);
60	struct dma_channel *channel = &info->channels[chan];
61
62	info->ops->xfer(channel);
63}
64EXPORT_SYMBOL(enable_dma);
65
66void clear_dma_ff(unsigned int chan)
67{
68	/* Nothing */
69}
70EXPORT_SYMBOL(clear_dma_ff);
71
72void set_dma_mode(unsigned int chan, char mode)
73{
74	struct dma_info *info = get_dma_info(chan);
75	struct dma_channel *channel = &info->channels[chan];
76
77	channel->mode = mode;
78}
79EXPORT_SYMBOL(set_dma_mode);
80
81void set_dma_addr(unsigned int chan, unsigned int addr)
82{
83	struct dma_info *info = get_dma_info(chan);
84	struct dma_channel *channel = &info->channels[chan];
85
86	/*
87	 * Single address mode is the only thing supported through
88	 * this interface.
89	 */
90	if ((channel->mode & DMA_MODE_MASK) == DMA_MODE_READ) {
91		channel->sar = addr;
92	} else {
93		channel->dar = addr;
94	}
95}
96EXPORT_SYMBOL(set_dma_addr);
97
98void set_dma_count(unsigned int chan, unsigned int count)
99{
100	struct dma_info *info = get_dma_info(chan);
101	struct dma_channel *channel = &info->channels[chan];
102
103	channel->count = count;
104}
105EXPORT_SYMBOL(set_dma_count);
106