Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

ddi_dma_setup(9f) [posix man page]

ddi_dma_setup(9F)					   Kernel Functions for Drivers 					 ddi_dma_setup(9F)

ddi_dma_setup - setup DMA resources SYNOPSIS
#include <sys/ddi.h> #include <sys/sunddi.h> int ddi_dma_setup(dev_info_t *dip, ddi_dma_req_t *dmareqp, ddi_dma_handle_t *handlep); INTERFACE LEVEL
This interface is obsolete. The functions ddi_dma_addr_bind_handle(9F), ddi_dma_alloc_handle(9F), ddi_dma_buf_bind_handle(9F), ddi_dma_free_handle(9F), and ddi_dma_unbind_handle(9F) should be used instead. PARAMETERS
dip A pointer to the device's dev_info structure. dmareqp A pointer to a DMA request structure (see ddi_dma_req(9S)). handlep A pointer to a DMA handle to be filled in. See below for a discussion of a handle. If handlep is NULL, the call to ddi_dma_setup() is considered an advisory call, in which case no resources are allocated, but a value indicating the legal- ity and the feasibility of the request is returned. DESCRIPTION
ddi_dma_setup() allocates resources for a memory object such that a device can perform DMA to or from that object. A call to ddi_dma_setup() informs the system that device referred to by dip wishes to perform DMA to or from a memory object. The memory object, the device's DMA capabilities, the device driver's policy on whether to wait for resources, are all specified in the ddi_dma_req structure pointed to by dmareqp. A successful call to ddi_dma_setup() fills in the value pointed to by handlep. This is an opaque object called a DMA handle. This handle is then used in subsequent DMA calls, until ddi_dma_free(9F) is called. Again a DMA handle is opaque--drivers may not attempt to interpret its value. When a driver wants to enable its DMA engine, it must retrieve the appropriate address to supply to its DMA engine using a call to ddi_dma_htoc(9F), which takes a pointer to a DMA handle and returns the appropriate DMA address. When DMA transfer completes, the driver should free up the the allocated DMA resources by calling ddi_dma_free(). RETURN VALUES
ddi_dma_setup() returns: DDI_DMA_MAPPED Successfully allocated resources for the object. In the case of an advisory call, this indicates that the request is legal. DDI_DMA_PARTIAL_MAP Successfully allocated resources for a part of the object. This is acceptable when partial transfers are allowed using a flag setting in the ddi_dma_req structure (see ddi_dma_req(9S) and ddi_dma_movwin(9F)). DDI_DMA_NORESOURCES When no resources are available. DDI_DMA_NOMAPPING The object cannot be reached by the device requesting the resources. DDI_DMA_TOOBIG The object is too big and exceeds the available resources. The maximum size varies depending on machine and config- uration. CONTEXT
ddi_dma_setup() can be called from user or interrupt context, except when the dmar_fp member of the ddi_dma_req structure pointed to by dmareqp is set to DDI_DMA_SLEEP, in which case it can be called from user context only. ATTRIBUTES
See attributes(5) for a description of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Stability Level |Obsolete | +-----------------------------+-----------------------------+ SEE ALSO
attributes(5), ddi_dma_addr_bind_handle(9F), ddi_dma_alloc_handle(9F), ddi_dma_buf_bind_handle(9F), ddi_dma_free_handle(9F), ddi_dma_unbind_handle(9F)ddi_dma_addr_setup(9F), ddi_dma_buf_setup(9F), ddi_dma_free(9F), ddi_dma_htoc(9F), ddi_dma_movwin(9F), ddi_dma_sync(9F), ddi_dma_req(9S) Writing Device Drivers NOTES
The construction of the ddi_dma_req structure is complicated. Use of the provided interface functions such as ddi_dma_buf_setup(9F) simpli- fies this task. SunOS 5.10 27 Sep 2002 ddi_dma_setup(9F)
Man Page