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

NAME

       ddi_dma_coff - convert a DMA cookie to an offset within a DMA handle

SYNOPSIS

       #include <sys/conf.h>
       #include <sys/ddi.h>
       #include <sys/sunddi.h>

       int ddi_dma_coff(ddi_dma_handle_t handle, ddi_dma_cookie_t *cookiep, off_t *offp);

INTERFACE LEVEL

       Solaris SPARC DDI (Solaris SPARC DDI).

PARAMETERS

       handle	       The handle filled in by a call to ddi_dma_setup(9F).

       cookiep	       A pointer to a DMA cookie (see ddi_dma_cookie(9S)) that contains the appropriate address, length and bus type to be used in
		       programming the DMA engine.

       offp	       A pointer to an offset to be filled in.

DESCRIPTION

       ddi_dma_coff() converts the values in DMA cookie pointed to by cookiep to an offset (in bytes) from the beginning of the  object  that  the
       DMA handle has mapped.

       ddi_dma_coff() allows a driver to update a DMA cookie with values it reads from its device's DMA engine after a transfer completes and con-
       vert that value into an offset into the object that is mapped for DMA.

RETURN VALUES

       ddi_dma_coff() returns:

       DDI_SUCCESS     Successfully filled in offp.

       DDI_FAILURE     Failed to successfully fill in offp.

CONTEXT

       ddi_dma_coff() can be called from user or interrupt context.

SEE ALSO

       ddi_dma_setup(9F), ddi_dma_sync(9F), ddi_dma_cookie(9S)

       Writing Device Drivers

SunOS 5.10							    4 Nov 1991							  ddi_dma_coff(9F)