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 convert 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