aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/plat-samsung/dma-ops.c
blob: eb9f4f5340060d432f7fd6741a3acfc6fbfa2dbc (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
/* linux/arch/arm/plat-samsung/dma-ops.c
 *
 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com
 *
 * Samsung DMA Operations
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/amba/pl330.h>
#include <linux/scatterlist.h>
#include <linux/export.h>

#include <mach/dma.h>

static unsigned samsung_dmadev_request(enum dma_ch dma_ch,
				struct samsung_dma_info *info)
{
	struct dma_chan *chan;
	dma_cap_mask_t mask;
	struct dma_slave_config slave_config;
	void *filter_param;

	dma_cap_zero(mask);
	dma_cap_set(info->cap, mask);

	/*
	 * If a dma channel property of a device node from device tree is
	 * specified, use that as the fliter parameter.
	 */
	filter_param = (dma_ch == DMACH_DT_PROP) ? (void *)info->dt_dmach_prop :
				(void *)dma_ch;
	chan = dma_request_channel(mask, pl330_filter, filter_param);

	if (info->direction == DMA_DEV_TO_MEM) {
		memset(&slave_config, 0, sizeof(struct dma_slave_config));
		slave_config.direction = info->direction;
		slave_config.src_addr = info->fifo;
		slave_config.src_addr_width = info->width;
		slave_config.src_maxburst = 1;
		dmaengine_slave_config(chan, &slave_config);
	} else if (info->direction == DMA_MEM_TO_DEV) {
		memset(&slave_config, 0, sizeof(struct dma_slave_config));
		slave_config.direction = info->direction;
		slave_config.dst_addr = info->fifo;
		slave_config.dst_addr_width = info->width;
		slave_config.dst_maxburst = 1;
		dmaengine_slave_config(chan, &slave_config);
	}

	return (unsigned)chan;
}

static int samsung_dmadev_release(unsigned ch,
			struct s3c2410_dma_client *client)
{
	dma_release_channel((struct dma_chan *)ch);

	return 0;
}

static int samsung_dmadev_prepare(unsigned ch,
			struct samsung_dma_prep_info *info)
{
	struct scatterlist sg;
	struct dma_chan *chan = (struct dma_chan *)ch;
	struct dma_async_tx_descriptor *desc;

	switch (info->cap) {
	case DMA_SLAVE:
		sg_init_table(&sg, 1);
		sg_dma_len(&sg) = info->len;
		sg_set_page(&sg, pfn_to_page(PFN_DOWN(info->buf)),
			    info->len, offset_in_page(info->buf));
		sg_dma_address(&sg) = info->buf;

		desc = dmaengine_prep_slave_sg(chan,
			&sg, 1, info->direction, DMA_PREP_INTERRUPT);
		break;
	case DMA_CYCLIC:
		desc = dmaengine_prep_dma_cyclic(chan,
			info->buf, info->len, info->period, info->direction);
		break;
	default:
		dev_err(&chan->dev->device, "unsupported format\n");
		return -EFAULT;
	}

	if (!desc) {
		dev_err(&chan->dev->device, "cannot prepare cyclic dma\n");
		return -EFAULT;
	}

	desc->callback = info->fp;
	desc->callback_param = info->fp_param;

	dmaengine_submit((struct dma_async_tx_descriptor *)desc);

	return 0;
}

static inline int samsung_dmadev_trigger(unsigned ch)
{
	dma_async_issue_pending((struct dma_chan *)ch);

	return 0;
}

static inline int samsung_dmadev_flush(unsigned ch)
{
	return dmaengine_terminate_all((struct dma_chan *)ch);
}

static struct samsung_dma_ops dmadev_ops = {
	.request	= samsung_dmadev_request,
	.release	= samsung_dmadev_release,
	.prepare	= samsung_dmadev_prepare,
	.trigger	= samsung_dmadev_trigger,
	.started	= NULL,
	.flush		= samsung_dmadev_flush,
	.stop		= samsung_dmadev_flush,
};

void *samsung_dmadev_get_ops(void)
{
	return &dmadev_ops;
}
EXPORT_SYMBOL(samsung_dmadev_get_ops);