Re: [PATCH v3 6/6] dmaengine: loongson: New driver for the Loongson Multi-Channel DMA controller

[Vinod Koul <vkoul@kernel.org>]

On 26-02-26, 16:18, Huacai Chen wrote:
> Hi, Binbin,
> 
> On Wed, Feb 25, 2026 at 3:41 PM Binbin Zhou <zhoubinbin@loongson.cn> wrote:
> >
> > This DMA controller appears in Loongson-2K0300 and Loongson-2K3000.
> >
> > It is a chain multi-channel controller that enables data transfers from
> > memory to memory, device to memory, and memory to device, as well as
> > channel prioritization configurable through the channel configuration
> > registers.
> >
> > In addition, there are slight differences between Loongson-2K0300 and
> > Loongson-2K3000, such as channel register offsets and the number of
> > channels.
> >
> > Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
> > ---
> >  MAINTAINERS                                  |   1 +
> >  drivers/dma/loongson/Kconfig                 |  10 +
> >  drivers/dma/loongson/Makefile                |   1 +
> >  drivers/dma/loongson/loongson2-apb-cmc-dma.c | 729 +++++++++++++++++++
> >  4 files changed, 741 insertions(+)
> >  create mode 100644 drivers/dma/loongson/loongson2-apb-cmc-dma.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index aea29c28d865..af9fbb3b43e2 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -14954,6 +14954,7 @@ L:      dmaengine@vger.kernel.org
> >  S:     Maintained
> >  F:     Documentation/devicetree/bindings/dma/loongson,ls2k0300-dma.yaml
> >  F:     Documentation/devicetree/bindings/dma/loongson,ls2x-apbdma.yaml
> > +F:     drivers/dma/loongson/loongson2-apb-cmc-dma.c
> >  F:     drivers/dma/loongson/loongson2-apb-dma.c
> >
> >  LOONGSON LS2X I2C DRIVER
> > diff --git a/drivers/dma/loongson/Kconfig b/drivers/dma/loongson/Kconfig
> > index 9dbdaef5a59f..4278fbbe8096 100644
> > --- a/drivers/dma/loongson/Kconfig
> > +++ b/drivers/dma/loongson/Kconfig
> > @@ -12,6 +12,16 @@ config LOONGSON1_APB_DMA
> >           This selects support for the APB DMA controller in Loongson1 SoCs,
> >           which is required by Loongson1 NAND and audio support.
> >
> > +config LOONGSON2_APB_CMC_DMA
> > +       tristate "Loongson2 Chain Multi-Channel DMA support"
> > +       select DMA_ENGINE
> > +       select DMA_VIRTUAL_CHANNELS
> > +       help
> > +         Support for the Loongson Chain Multi-Channel DMA controller driver.
> > +         It is discovered on the Loongson-2K chip (Loongson-2K0300/Loongson-2K3000),
> > +         which has 4/8 channels internally, enabling bidirectional data transfer
> > +         between devices and memory.
> Moving this to after LOONGSON2_APB_DMA is a little better.

Yes and we expect these files to be sorted, so this needs to be done

-- 
~Vinod