DRV_DMA

DRV_DMA API Status

API
`drv_dma_device_init()`
`drv_dma_device_deinit()`
`drv_dma_chn_alloc()`
`drv_dma_chn_free()`
`drv_dma_cfg_callback()`
`drv_dma_cfg_param()`
`drv_dma_cfg_hw_request()`
`drv_dma_load()`
`drv_dma_update_loop_pause_addr()`
`drv_dma_chn_enable()`
`drv_dma_chn_is_enabled()`
`drv_dma_get_remain_len()`
`drv_dma_get_src_read_addr()`
`drv_dma_get_dst_write_addr()`
`drv_dma_flush_unaligned_data()`
`drv_dma_wait_flush_unaligned_data_done()`
`drv_dma_get_loop_pause_addr()`

DRV_DMA API Reference

Header File

driver/dma/drv_dma.h

Functions

int32_t drv_dma_device_init(uint32_t dev_index)

init a dma device.

初始化dma设备，通常是在系统开始初始化的时候调用一次

参数:

dev_index – [in] device index, from 0(the first device)

返回值:

0 – success [BK_RET_OK]
other – fail

返回:

result

int32_t drv_dma_device_deinit(uint32_t dev_index)

deinit a dma device.

反初始化dma设备，所有的dma channel都没用的时候才能返回成功，通常可能不会被调用

参数:

dev_index – [in] device index, same as drv_dma_device_init()

返回值:

0 – success [BK_RET_OK]
other – fail

返回:

result

uint32_t drv_dma_chn_alloc(uint32_t dev_index, int32_t req_chn_index)

alloc a dma channel.

从这个dma设备中分配出一个dma channel，后续操作dma channel需要用到该函数的返回值

参数:

dev_index – [in] device index, from 0(the first device)
req_chn_index – [in] -1: 不指定，随机分配 >=0: 指定对应的channel

返回值:

0 – fail
other – success

返回:

dma channel instance

int32_t drv_dma_chn_free(uint32_t chn_instance)

free dma channel.

释放dma channel，当不再使用该channel时需要调用该函数以让该channel被其他人使用

参数:

chn_instance – [in] return value of drv_dma_chn_alloc()

返回值:

0 – success [BK_RET_OK]
other – fail

返回:

result

int32_t drv_dma_cfg_callback(uint32_t chn_instance, int32_t priority, pfunc_dma_cb_t pfn_half, pfunc_dma_cb_t pfn_finish, void *pv_cb_arg)

config dma channel callback.

配置dma搬移完成的callback，如果不想处理callback，对应的参数传NULL即可如果不想处理callback，也应该调用该函数，避免误调上次使用该channel的人的callback

参数:

chn_instance – [in] return value of drv_dma_chn_alloc()
priority – [in] 该channel的优先级(0~7), 7是最高优先级
pfn_half – [in] 搬移完成一半的时候出的callback
pfn_finish – [in] 全部搬移完成出的callback
pv_cb_arg – [in] callback带的参数

返回值:

0 – success [BK_RET_OK]
other – fail

返回:

result

int32_t drv_dma_cfg_param(uint32_t chn_instance, dma_mode_e mode, dma_data_width_e src_data_width, dma_data_width_e dst_data_width, dma_burst_type_e src_burst_len, dma_burst_type_e dst_burst_len)

config dma channel parameter.

配置该dma channel的一些参数, 需要在 drv_dma_load() 之前调用

参数:

chn_instance – [in] return value of drv_dma_chn_alloc()
mode – [in] see dma_mode_e
src_data_width – [in] source data width, see dma_data_width_e
dst_data_width – [in] destination data width, see dma_data_width_e
src_burst_len – [in] source burst length, see dma_burst_type_e
dst_burst_len – [in] destination burst length, see dma_burst_type_e

返回值:

0 – success [BK_RET_OK]
other – fail

返回:

result

int32_t drv_dma_cfg_hw_request(uint32_t chn_instance, dma_from_to_e e_src_dst, dma_req_mux_e e_req)

config HW request for this dma channel.

对该dma channel的源和目标选择对应的硬件request信号，外设使用dma的时候需要进行配置

参数:

chn_instance – [in] return value of drv_dma_chn_alloc()
e_src_dst – [in] 选择源还是目标，see dma_from_to_e
e_req – [in] dma request, see dma_req_mux_e

返回值:

0 – success [BK_RET_OK]
other – fail

返回:

result

int32_t drv_dma_load(uint32_t chn_instance, uint32_t transmit_bytes, uint32_t src_addr_start, uint32_t dst_addr_start, uint32_t src_addr_end, uint32_t dst_addr_end)

load dma address and length.

加载dma搬移的长度和地址，end地址也需要配置，用来判断是否是不动的FIFO地址调用该函数前应该先调用 drv_dma_cfg_param() 和 drv_dma_cfg_hw_request()

参数:

chn_instance – [in] return value of drv_dma_chn_alloc()
transmit_bytes – [in] 以byte为单位的搬移长度
src_addr_start – [in] 搬移源的开始地址，需要和data width对齐
dst_addr_start – [in] 搬移目标的开始地址，需要和data width对齐
src_addr_end – [in] 搬移源的结束地址，对于memory to memory, 该地址等于transmit_bytes + src_addr_start
dst_addr_end – [in] 搬移目标的结束地址，对于memory to memory, 该地址等于transmit_bytes + dst_addr_start

返回值:

0 – success [BK_RET_OK]
other – fail

返回:

result

int32_t drv_dma_update_loop_pause_addr(uint32_t chn_instance, dma_from_to_e e_src_dst, uint32_t addr)

config pause address in loop mode.

对于循环重复搬移的情况，涉及到读写数据的同步问题，该地址用来告诉dma读写的时候不用越过它例如，将memory数据循环搬到codec中，如果软件动作太慢，则dma会搬到一些软件还未填写的数据如果软件配置了pause address，则dma会在到达这个地址后等到软件填了数据，更新地址后再进行搬数

参数:

chn_instance – [in] return value of drv_dma_chn_alloc()
e_src_dst – [in] 配置源还是目标，see dma_from_to_e
addr – [in] pause address for dma

返回值:

0 – success [BK_RET_OK]
other – fail

返回:

result

int32_t drv_dma_chn_enable(uint32_t chn_instance, bool enable)

enable dma channel or not.

使能该dma channel

参数:

chn_instance – [in] return value of drv_dma_chn_alloc()
enable – [in] true: enable false: disable

返回值:

0 – success [BK_RET_OK]
other – fail

返回:

result

bool drv_dma_chn_is_enabled(uint32_t chn_instance)

check the dma channel is enabled or not.

参数:

chn_instance – [in] return value of drv_dma_chn_alloc()

返回值:

true – dma channel is enabled
false – dma channel is not enabled

返回:

is enabled

uint32_t drv_dma_get_remain_len(uint32_t chn_instance)

get remain length.

dma还未完成搬移，通过该函数可以知道还剩多少数据未搬

参数:: chn_instance – [in] return value of drv_dma_chn_alloc()
返回:: left size in bytes.

uint32_t drv_dma_get_src_read_addr(uint32_t chn_instance)

get source read address.

获取此时dma搬移源的读地址(下一个要读的地址)

参数:: chn_instance – [in] return value of drv_dma_chn_alloc()
返回:: source read pointer

uint32_t drv_dma_get_dst_write_addr(uint32_t chn_instance)

get destination write address.

获取此时dma搬移目标的写地址(下一个要写的地址)

参数:: chn_instance – [in] return value of drv_dma_chn_alloc()
返回:: destination write pointer

int32_t drv_dma_flush_unaligned_data(uint32_t chn_instance)

flush unaligned data in dma channel.

如果因为对齐原因导致dma无法送出部分数据，可以调用该接口

参数:

chn_instance – [in] return value of drv_dma_chn_alloc()

返回值:

0 – success [BK_RET_OK]
other – fail

返回:

result

void drv_dma_wait_flush_unaligned_data_done(uint32_t chn_instance)

wait flush unaligned data finish.

该函数会阻塞直到dma将flush动作完成，实际上是很快完成的的，通常不会在该函数中while住

参数:: chn_instance – [in] return value of drv_dma_chn_alloc()
返回:: N/A

int32_t drv_dma_get_loop_pause_addr(uint32_t chn_instance, dma_from_to_e e_src_dst)

drv_dma_get_loop_pause_addr brief description

得到当前的pause地址

参见

备注

参数:

chn_instance – [in]
e_src_dst – [in]

返回值:

0 – success
other – fail

返回:

result

Macros

DMA_DEVICE_NUM

Type Definitions

typedef enum _dma_mode_e dma_mode_e

typedef enum _dma_from_to_e dma_from_to_e

typedef enum _dma_data_width_e dma_data_width_e

typedef enum _dma_burst_type_e dma_burst_type_e

typedef void (*pfunc_dma_cb_t)(uint32_t chn_instance, void *pv_arg)

Enumerations

enum _dma_mode_e

Values:

enumerator DRV_DMA_SINGLE_XFER

enumerator DRV_DMA_LOOP_REPEAT

single transfer

repeat forever

enum _dma_from_to_e

Values:

enumerator DRV_DMA_SOURCE

enumerator DRV_DMA_DESTINATION

from source

to destination

enum _dma_data_width_e

Values:

enumerator DRV_DMA_1BYTE

enumerator DRV_DMA_2BYTE: 1byte

enumerator DRV_DMA_4BYTE: 2bytes, half word

enum _dma_burst_type_e

Values:

enumerator DRV_DMA_SINGLE

enumerator DRV_DMA_4ITEMS: single, no burst transfer

enumerator DRV_DMA_8ITEMS: 4 burst at a time

enumerator DRV_DMA_16ITEMS: 8 burst at a time