diff options
Diffstat (limited to 'drivers/misc/bcm-vk/bcm_vk_sg.h')
| -rw-r--r-- | drivers/misc/bcm-vk/bcm_vk_sg.h | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/drivers/misc/bcm-vk/bcm_vk_sg.h b/drivers/misc/bcm-vk/bcm_vk_sg.h new file mode 100644 index 000000000..81b3d0976 --- /dev/null +++ b/drivers/misc/bcm-vk/bcm_vk_sg.h @@ -0,0 +1,61 @@ +/* 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 + |