dma-uclass.h
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/* 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);
/**
* rfree - 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 (*rfree)(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);
/**
* get_cfg() - Get DMA channel configuration for client's use
*
* @dma: The DMA Channel to manipulate
* @cfg_id: DMA provider specific ID to identify what
* configuration data client needs
* @data: Pointer to store pointer to DMA driver specific
* configuration data for the given cfg_id (output param)
* @return zero on success, or -ve error code.
*/
int (*get_cfg)(struct dma *dma, u32 cfg_id, void **data);
#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 */