| Mugunthan V N | 8c3c918 | 2016-02-15 15:31:37 +0530 | [diff] [blame] | 1 | /* |
| 2 | * (C) Copyright 2015 |
| 3 | * Texas Instruments Incorporated, <www.ti.com> |
| 4 | * |
| 5 | * SPDX-License-Identifier: GPL-2.0+ |
| 6 | */ |
| 7 | |
| 8 | #ifndef _DMA_H_ |
| 9 | #define _DMA_H_ |
| 10 | |
| 11 | /* |
| 12 | * enum dma_direction - dma transfer direction indicator |
| 13 | * @DMA_MEM_TO_MEM: Memcpy mode |
| 14 | * @DMA_MEM_TO_DEV: From Memory to Device |
| 15 | * @DMA_DEV_TO_MEM: From Device to Memory |
| 16 | * @DMA_DEV_TO_DEV: From Device to Device |
| 17 | */ |
| 18 | enum dma_direction { |
| 19 | DMA_MEM_TO_MEM, |
| 20 | DMA_MEM_TO_DEV, |
| 21 | DMA_DEV_TO_MEM, |
| 22 | DMA_DEV_TO_DEV, |
| 23 | }; |
| 24 | |
| 25 | #define DMA_SUPPORTS_MEM_TO_MEM BIT(0) |
| 26 | #define DMA_SUPPORTS_MEM_TO_DEV BIT(1) |
| 27 | #define DMA_SUPPORTS_DEV_TO_MEM BIT(2) |
| 28 | #define DMA_SUPPORTS_DEV_TO_DEV BIT(3) |
| 29 | |
| 30 | /* |
| 31 | * struct dma_ops - Driver model DMA operations |
| 32 | * |
| 33 | * The uclass interface is implemented by all DMA devices which use |
| 34 | * driver model. |
| 35 | */ |
| 36 | struct dma_ops { |
| 37 | /* |
| 38 | * Get the current timer count |
| 39 | * |
| 40 | * @dev: The DMA device |
| 41 | * @direction: direction of data transfer should be one from |
| 42 | enum dma_direction |
| 43 | * @dst: Destination pointer |
| 44 | * @src: Source pointer |
| 45 | * @len: Length of the data to be copied. |
| 46 | * @return: 0 if OK, -ve on error |
| 47 | */ |
| 48 | int (*transfer)(struct udevice *dev, int direction, void *dst, |
| 49 | void *src, size_t len); |
| 50 | }; |
| 51 | |
| 52 | /* |
| 53 | * struct dma_dev_priv - information about a device used by the uclass |
| 54 | * |
| 55 | * @supported: mode of transfers that DMA can support, should be |
| 56 | * one/multiple of DMA_SUPPORTS_* |
| 57 | */ |
| 58 | struct dma_dev_priv { |
| 59 | u32 supported; |
| 60 | }; |
| 61 | |
| 62 | /* |
| 63 | * dma_get_device - get a DMA device which supports transfer |
| 64 | * type of transfer_type |
| 65 | * |
| 66 | * @transfer_type - transfer type should be one/multiple of |
| 67 | * DMA_SUPPORTS_* |
| 68 | * @devp - udevice pointer to return the found device |
| 69 | * @return - will return on success and devp will hold the |
| 70 | * pointer to the device |
| 71 | */ |
| 72 | int dma_get_device(u32 transfer_type, struct udevice **devp); |
| 73 | |
| 74 | /* |
| 75 | * dma_memcpy - try to use DMA to do a mem copy which will be |
| 76 | * much faster than CPU mem copy |
| 77 | * |
| 78 | * @dst - destination pointer |
| 79 | * @src - souce pointer |
| 80 | * @len - data length to be copied |
| 81 | * @return - on successful transfer returns no of bytes |
| 82 | transferred and on failure return error code. |
| 83 | */ |
| 84 | int dma_memcpy(void *dst, void *src, size_t len); |
| 85 | |
| 86 | #endif /* _DMA_H_ */ |