static int sh_dmac_xfer_dma(struct dma_channel *chan)
{
/*
* If we haven't pre-configured the channel with special flags, use
* the defaults.
*/
if (unlikely(!(chan->flags & DMA_CONFIGURED)))
sh_dmac_configure_channel(chan, 0);
sh_dmac_disable_dma(chan);
/*
* Single-address mode usage note!
*
* It's important that we don't accidentally write any value to SAR/DAR
* (this includes 0) that hasn't been directly specified by the user if
* we're in single-address mode.
*
* In this case, only one address can be defined, anything else will
* result in a DMA address error interrupt (at least on the SH-4),
* which will subsequently halt the transfer.
*
* Channel 2 on the Dreamcast is a special case, as this is used for
* cascading to the PVR2 DMAC. In this case, we still need to write
* SAR and DAR, regardless of value, in order for cascading to work.
*/
if (chan->sar || (mach_is_dreamcast() &&
chan->chan == PVR2_CASCADE_CHAN))
ctrl_outl(chan->sar, SAR[chan->chan]);
if (chan->dar || (mach_is_dreamcast() &&
chan->chan == PVR2_CASCADE_CHAN))
ctrl_outl(chan->dar, DAR[chan->chan]);
ctrl_outl(chan->count >> calc_xmit_shift(chan), DMATCR[chan->chan]);
sh_dmac_enable_dma(chan);
return 0;
}
static int sh_dmac_xfer_dma(struct dma_info *info)
{
/*
* If we haven't pre-configured the channel with special flags, use
* the defaults.
*/
if (!info->configured)
sh_dmac_configure_channel(info, 0);
sh_dmac_disable_dma(info);
/*
* Single-address mode usage note!
*
* It's important that we don't accidentally write any value to SAR/DAR
* (this includes 0) that hasn't been directly specified by the user if
* we're in single-address mode.
*
* In this case, only one address can be defined, anything else will
* result in a DMA address error interrupt (at least on the SH-4),
* which will subsequently halt the transfer.
*
* Channel 2 on the Dreamcast is a special case, as this is used for
* cascading to the PVR2 DMAC. In this case, we still need to write
* SAR and DAR, regardless of value, in order for cascading to work.
*/
if (info->sar || (mach_is_dreamcast() && info->chan == 2))
sh_dmac->channel[info->chan].sar = info->sar;
if (info->dar || (mach_is_dreamcast() && info->chan == 2))
sh_dmac->channel[info->chan].dar = info->dar;
sh_dmac->channel[info->chan].dmatcr = info->count >> calc_xmit_shift(info);
sh_dmac_enable_dma(info);
return 0;
}
