Re: [PATCH v4 16/19] dmaengine: ti: k3-udma-v2: Add support for PKTDMA V2

[Sai Sree Kartheek Adivi]

On 03/02/26 11:55, Péter Ujfalusi wrote:
> On 30/01/2026 13:01, Sai Sree Kartheek Adivi wrote:
> > The PKTDMA V2 is different than the existing PKTDMA supported by the
> > k3-udma driver.
> >
> > The changes in PKTDMA V2 are:
> > - Autopair: There is no longer a need for PSIL pair and AUTOPAIR bit
> >    needs to set in the RT_CTL register.
> > - Static channel mapping: Each channel is mapped to a single
> >    peripheral.
> > - Direct IRQs: There is no INT-A and interrupt lines from DMA are
> >    directly connected to GIC.
> > - Remote side configuration handled by DMA. So no need to write to
> >    PEER registers to START / STOP / PAUSE / TEARDOWN.
> Plus I suppose..
>
> > Signed-off-by: Sai Sree Kartheek Adivi <s-adivi@xxxxxx>
> > ---
> >   drivers/dma/ti/k3-udma-common.c |  29 ++++-
> >   drivers/dma/ti/k3-udma-v2.c     | 219 ++++++++++++++++++++++++++++++--
> >   drivers/dma/ti/k3-udma.h        |   3 +
> >   3 files changed, 232 insertions(+), 19 deletions(-)
> >
> > diff --git a/drivers/dma/ti/k3-udma-common.c b/drivers/dma/ti/k3-udma-common.c
> > index ba0fc048234ac..d6459bcc17599 100644
> > --- a/drivers/dma/ti/k3-udma-common.c
> > +++ b/drivers/dma/ti/k3-udma-common.c
> > @@ -2461,12 +2461,21 @@ int pktdma_setup_resources(struct udma_dev *ud)
> >   
> >   	ud->tchan_map = devm_kmalloc_array(dev, BITS_TO_LONGS(ud->tchan_cnt),
> >   					   sizeof(unsigned long), GFP_KERNEL);
> > +	bitmap_zero(ud->tchan_map, ud->tchan_cnt);
> >   	ud->tchans = devm_kcalloc(dev, ud->tchan_cnt, sizeof(*ud->tchans),
> >   				  GFP_KERNEL);
> > -	ud->rchan_map = devm_kmalloc_array(dev, BITS_TO_LONGS(ud->rchan_cnt),
> > -					   sizeof(unsigned long), GFP_KERNEL);
> > -	ud->rchans = devm_kcalloc(dev, ud->rchan_cnt, sizeof(*ud->rchans),
> > -				  GFP_KERNEL);
> > +	if (ud->match_data->type == DMA_TYPE_PKTDMA_V2) {
> > +		ud->rchan_map = ud->tchan_map;
> > +		ud->rchans = ud->tchans;
> > +		ud->chan_map = ud->tchan_map;
> > +		ud->chans = ud->tchans;
> It has single channel space and the TX/RX functionality alternates
> within the space?
> chX: TX, chX+1: TX, chX+2: RX, chX+3: TX, etc?
Yes Peter, that is the case.
> > +	} else {
> > +		ud->rchan_map = devm_kmalloc_array(dev, BITS_TO_LONGS(ud->rchan_cnt),
> > +						   sizeof(unsigned long), GFP_KERNEL);
> > +		bitmap_zero(ud->rchan_map, ud->rchan_cnt);
> > +		ud->rchans = devm_kcalloc(dev, ud->rchan_cnt, sizeof(*ud->rchans),
> > +					  GFP_KERNEL);
> > +	}
> ...
>
> > diff --git a/drivers/dma/ti/k3-udma-v2.c b/drivers/dma/ti/k3-udma-v2.c
> > index af06d25fd598b..6761a079025ba 100644
> > --- a/drivers/dma/ti/k3-udma-v2.c
> > +++ b/drivers/dma/ti/k3-udma-v2.c
> > @@ -744,6 +744,146 @@ static int bcdma_v2_alloc_chan_resources(struct dma_chan *chan)
> >   	return ret;
> >   }
> >   
> > +static int pktdma_v2_alloc_chan_resources(struct dma_chan *chan)
> > +{
> > +	struct udma_chan *uc = to_udma_chan(chan);
> > +	struct udma_dev *ud = to_udma_dev(chan->device);
> > +	u32 irq_ring_idx;
> > +	__be32 addr[2] = {0, 0};
> > +	struct of_phandle_args out_irq;
> > +	int ret;
> Nitpick: revers christmas tree declaration order.