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https://github.com/AsahiLinux/u-boot
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a0594cefb7
Implement a DMA uclass so that the devices like ethernet, spi, mmc etc can offload the data transfers from/to the device and memory. Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com> Reviewed-by: Simon Glass <sjg@chromium.org> Reviewed-by: Jagan Teki <jteki@openedev.com>
86 lines
2.1 KiB
C
86 lines
2.1 KiB
C
/*
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* (C) Copyright 2015
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* Texas Instruments Incorporated, <www.ti.com>
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#ifndef _DMA_H_
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#define _DMA_H_
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/*
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* enum dma_direction - dma transfer direction indicator
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* @DMA_MEM_TO_MEM: Memcpy mode
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* @DMA_MEM_TO_DEV: From Memory to Device
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* @DMA_DEV_TO_MEM: From Device to Memory
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* @DMA_DEV_TO_DEV: From Device to Device
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*/
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enum dma_direction {
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DMA_MEM_TO_MEM,
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DMA_MEM_TO_DEV,
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DMA_DEV_TO_MEM,
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DMA_DEV_TO_DEV,
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};
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#define DMA_SUPPORTS_MEM_TO_MEM BIT(0)
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#define DMA_SUPPORTS_MEM_TO_DEV BIT(1)
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#define DMA_SUPPORTS_DEV_TO_MEM BIT(2)
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#define DMA_SUPPORTS_DEV_TO_DEV BIT(3)
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/*
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* struct dma_ops - Driver model DMA operations
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*
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* The uclass interface is implemented by all DMA devices which use
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* driver model.
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*/
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struct dma_ops {
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/*
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* Get the current timer count
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*
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* @dev: The DMA device
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* @direction: direction of data transfer should be one from
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enum dma_direction
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* @dst: Destination pointer
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* @src: Source pointer
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* @len: Length of the data to be copied.
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* @return: 0 if OK, -ve on error
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*/
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int (*transfer)(struct udevice *dev, int direction, void *dst,
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void *src, size_t len);
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};
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/*
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* struct dma_dev_priv - information about a device used by the uclass
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*
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* @supported: mode of transfers that DMA can support, should be
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* one/multiple of DMA_SUPPORTS_*
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*/
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struct dma_dev_priv {
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u32 supported;
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};
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/*
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* dma_get_device - get a DMA device which supports transfer
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* type of transfer_type
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*
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* @transfer_type - transfer type should be one/multiple of
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* DMA_SUPPORTS_*
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* @devp - udevice pointer to return the found device
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* @return - will return on success and devp will hold the
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* pointer to the device
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*/
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int dma_get_device(u32 transfer_type, struct udevice **devp);
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/*
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* dma_memcpy - try to use DMA to do a mem copy which will be
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* much faster than CPU mem copy
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*
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* @dst - destination pointer
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* @src - souce pointer
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* @len - data length to be copied
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* @return - on successful transfer returns no of bytes
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transferred and on failure return error code.
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*/
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int dma_memcpy(void *dst, void *src, size_t len);
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#endif /* _DMA_H_ */
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