linux/drivers/misc/bcm-vk/bcm_vk_sg.h

62 lines
1.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright 2018-2020 Broadcom.
*/
#ifndef BCM_VK_SG_H
#define BCM_VK_SG_H
#include <linux/dma-mapping.h>
struct bcm_vk_dma {
/* for userland buffer */
struct page **pages;
int nr_pages;
/* common */
dma_addr_t handle;
/*
* sglist is of the following LE format
* [U32] num_sg = number of sg addresses (N)
* [U32] totalsize = totalsize of data being transferred in sglist
* [U32] size[0] = size of data in address0
* [U32] addr_l[0] = lower 32-bits of address0
* [U32] addr_h[0] = higher 32-bits of address0
* ..
* [U32] size[N-1] = size of data in addressN-1
* [U32] addr_l[N-1] = lower 32-bits of addressN-1
* [U32] addr_h[N-1] = higher 32-bits of addressN-1
*/
u32 *sglist;
#define SGLIST_NUM_SG 0
#define SGLIST_TOTALSIZE 1
#define SGLIST_VKDATA_START 2
int sglen; /* Length (bytes) of sglist */
int direction;
};
struct _vk_data {
u32 size; /* data size in bytes */
u64 address; /* Pointer to data */
} __packed;
/*
* Scatter-gather DMA buffer API.
*
* These functions provide a simple way to create a page list and a
* scatter-gather list from userspace address and map the memory
* for DMA operation.
*/
int bcm_vk_sg_alloc(struct device *dev,
struct bcm_vk_dma *dma,
int dir,
struct _vk_data *vkdata,
int num);
int bcm_vk_sg_free(struct device *dev, struct bcm_vk_dma *dma, int num,
int *proc_cnt);
#endif