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Diffstat (limited to 'include/dma-uclass.h')
| -rw-r--r-- | include/dma-uclass.h | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/include/dma-uclass.h b/include/dma-uclass.h new file mode 100644 index 0000000..31b43fb --- /dev/null +++ b/include/dma-uclass.h @@ -0,0 +1,128 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (C) 2018 Álvaro Fernández Rojas <noltari@gmail.com> + * Copyright (C) 2015 - 2018 Texas Instruments Incorporated <www.ti.com> + * Written by Mugunthan V N <mugunthanvnm@ti.com> + * + */ + +#ifndef _DMA_UCLASS_H +#define _DMA_UCLASS_H + +/* See dma.h for background documentation. */ + +#include <dma.h> + +struct ofnode_phandle_args; + +/* + * struct dma_ops - Driver model DMA operations + * + * The uclass interface is implemented by all DMA devices which use + * driver model. + */ +struct dma_ops { +#ifdef CONFIG_DMA_CHANNELS + /** + * of_xlate - Translate a client's device-tree (OF) DMA specifier. + * + * The DMA core calls this function as the first step in implementing + * a client's dma_get_by_*() call. + * + * If this function pointer is set to NULL, the DMA core will use a + * default implementation, which assumes #dma-cells = <1>, and that + * the DT cell contains a simple integer DMA Channel. + * + * At present, the DMA API solely supports device-tree. If this + * changes, other xxx_xlate() functions may be added to support those + * other mechanisms. + * + * @dma: The dma struct to hold the translation result. + * @args: The dma specifier values from device tree. + * @return 0 if OK, or a negative error code. + */ + int (*of_xlate)(struct dma *dma, + struct ofnode_phandle_args *args); + /** + * request - Request a translated DMA. + * + * The DMA core calls this function as the second step in + * implementing a client's dma_get_by_*() call, following a successful + * xxx_xlate() call, or as the only step in implementing a client's + * dma_request() call. + * + * @dma: The DMA struct to request; this has been filled in by + * a previoux xxx_xlate() function call, or by the caller of + * dma_request(). + * @return 0 if OK, or a negative error code. + */ + int (*request)(struct dma *dma); + /** + * free - Free a previously requested dma. + * + * This is the implementation of the client dma_free() API. + * + * @dma: The DMA to free. + * @return 0 if OK, or a negative error code. + */ + int (*free)(struct dma *dma); + /** + * enable() - Enable a DMA Channel. + * + * @dma: The DMA Channel to manipulate. + * @return zero on success, or -ve error code. + */ + int (*enable)(struct dma *dma); + /** + * disable() - Disable a DMA Channel. + * + * @dma: The DMA Channel to manipulate. + * @return zero on success, or -ve error code. + */ + int (*disable)(struct dma *dma); + /** + * prepare_rcv_buf() - Prepare/Add receive DMA buffer. + * + * @dma: The DMA Channel to manipulate. + * @dst: The receive buffer pointer. + * @size: The receive buffer size + * @return zero on success, or -ve error code. + */ + int (*prepare_rcv_buf)(struct dma *dma, void *dst, size_t size); + /** + * receive() - Receive a DMA transfer. + * + * @dma: The DMA Channel to manipulate. + * @dst: The destination pointer. + * @metadata: DMA driver's specific data + * @return zero on success, or -ve error code. + */ + int (*receive)(struct dma *dma, void **dst, void *metadata); + /** + * send() - Send a DMA transfer. + * + * @dma: The DMA Channel to manipulate. + * @src: The source pointer. + * @len: Length of the data to be sent (number of bytes). + * @metadata: DMA driver's specific data + * @return zero on success, or -ve error code. + */ + int (*send)(struct dma *dma, void *src, size_t len, void *metadata); +#endif /* CONFIG_DMA_CHANNELS */ + /** + * transfer() - Issue a DMA transfer. The implementation must + * wait until the transfer is done. + * + * @dev: The DMA device + * @direction: direction of data transfer (should be one from + * enum dma_direction) + * @dst: The destination pointer. + * @src: The source pointer. + * @len: Length of the data to be copied (number of bytes). + * @return zero on success, or -ve error code. + */ + int (*transfer)(struct udevice *dev, int direction, void *dst, + void *src, size_t len); +}; + +#endif /* _DMA_UCLASS_H */ |