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
|
/*
* (C) Copyright 2015
* Texas Instruments Incorporated, <www.ti.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef _DMA_H_
#define _DMA_H_
/*
* enum dma_direction - dma transfer direction indicator
* @DMA_MEM_TO_MEM: Memcpy mode
* @DMA_MEM_TO_DEV: From Memory to Device
* @DMA_DEV_TO_MEM: From Device to Memory
* @DMA_DEV_TO_DEV: From Device to Device
*/
enum dma_direction {
DMA_MEM_TO_MEM,
DMA_MEM_TO_DEV,
DMA_DEV_TO_MEM,
DMA_DEV_TO_DEV,
};
#define DMA_SUPPORTS_MEM_TO_MEM BIT(0)
#define DMA_SUPPORTS_MEM_TO_DEV BIT(1)
#define DMA_SUPPORTS_DEV_TO_MEM BIT(2)
#define DMA_SUPPORTS_DEV_TO_DEV BIT(3)
/*
* struct dma_ops - Driver model DMA operations
*
* The uclass interface is implemented by all DMA devices which use
* driver model.
*/
struct dma_ops {
/*
* Get the current timer count
*
* @dev: The DMA device
* @direction: direction of data transfer should be one from
enum dma_direction
* @dst: Destination pointer
* @src: Source pointer
* @len: Length of the data to be copied.
* @return: 0 if OK, -ve on error
*/
int (*transfer)(struct udevice *dev, int direction, void *dst,
void *src, size_t len);
};
/*
* struct dma_dev_priv - information about a device used by the uclass
*
* @supported: mode of transfers that DMA can support, should be
* one/multiple of DMA_SUPPORTS_*
*/
struct dma_dev_priv {
u32 supported;
};
/*
* dma_get_device - get a DMA device which supports transfer
* type of transfer_type
*
* @transfer_type - transfer type should be one/multiple of
* DMA_SUPPORTS_*
* @devp - udevice pointer to return the found device
* @return - will return on success and devp will hold the
* pointer to the device
*/
int dma_get_device(u32 transfer_type, struct udevice **devp);
/*
* dma_memcpy - try to use DMA to do a mem copy which will be
* much faster than CPU mem copy
*
* @dst - destination pointer
* @src - souce pointer
* @len - data length to be copied
* @return - on successful transfer returns no of bytes
transferred and on failure return error code.
*/
int dma_memcpy(void *dst, void *src, size_t len);
#endif /* _DMA_H_ */
|
