#include <dmaengine.h>

Data Fields
enum dma_transfer_direction	direction

dma_addr_t	src_addr

dma_addr_t	dst_addr

enum dma_slave_buswidth	src_addr_width

enum dma_slave_buswidth	dst_addr_width

u32	src_maxburst

u32	dst_maxburst

bool	device_fc

unsigned int	slave_id

Detailed Description

struct dma_slave_config - dma slave channel runtime config : whether the data shall go in or out on this slave channel, right now. DMA_TO_DEVICE and DMA_FROM_DEVICE are legal values, DMA_BIDIRECTIONAL is not acceptable since we need to differentiate source and target addresses. : this is the physical address where DMA slave data should be read (RX), if the source is memory this argument is ignored. : this is the physical address where DMA slave data should be written (TX), if the source is memory this argument is ignored. : this is the width in bytes of the source (RX) register where DMA data shall be read. If the source is memory this may be ignored depending on architecture. Legal values: 1, 2, 4, 8. : same as src_addr_width but for destination target (TX) mutatis mutandis. : the maximum number of words (note: words, as in units of the src_addr_width member, not bytes) that can be sent in one burst to the device. Typically something like half the FIFO depth on I/O peripherals so you don't overflow it. This may or may not be applicable on memory sources. : same as src_maxburst but for destination target mutatis mutandis. : Flow Controller Settings. Only valid for slave channels. Fill with 'true' if peripheral should be flow controller. Direction will be selected at Runtime. : Slave requester id. Only valid for slave channels. The dma slave peripheral will have unique id as dma requester which need to be pass as slave config.

This struct is passed in as configuration data to a DMA engine in order to set up a certain channel for DMA transport at runtime. The DMA device/engine has to provide support for an additional command in the channel config interface, DMA_SLAVE_CONFIG and this struct will then be passed in as an argument to the DMA engine device_control() function.

The rationale for adding configuration information to this struct is as follows: if it is likely that most DMA slave controllers in the world will support the configuration option, then make it generic. If not: if it is fixed so that it be sent in static from the platform data, then prefer to do that. Else, if it is neither fixed at runtime, nor generic enough (such as bus mastership on some CPU family and whatnot) then create a custom slave config struct and pass that, then make this config a member of that struct, if applicable.

Definition at line 362 of file dmaengine.h.