Re: [PATCH v2 1/3] dmaengine: add DMA_PREP_CMD for non-Data descriptors.

From: Vinod Koul
Date: Wed Jul 19 2017 - 06:08:43 EST


On Mon, Jul 17, 2017 at 02:54:21PM +0530, Abhishek Sahu wrote:
> On 2017-06-26 18:19, Abhishek Sahu wrote:
> >Some of the DMA controllers are capable of issuing the commands
> >to peripheral by the DMA. These commands can be list of register
> >reads/writes and its different from normal data reads/writes.
> >This patch adds new flag DMA_PREP_CMD in DMA API which tells
> >the driver that the data passed to DMA API is in command format
> >and DMA driver will form descriptor in the required format.
> >
> >This flag can be used by any DMA controller driver which requires
> >special handling for non-Data descriptors.
> >
> >Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx>
> >---
> > include/linux/dmaengine.h | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> >diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
> >index 5336808..bbc297e 100644
> >--- a/include/linux/dmaengine.h
> >+++ b/include/linux/dmaengine.h
> >@@ -186,6 +186,8 @@ struct dma_interleaved_template {
> > * on the result of this operation
> > * @DMA_CTRL_REUSE: client can reuse the descriptor and submit again till
> > * cleared or freed
> >+ * @DMA_PREP_CMD: tell the driver that the data passed to DMA API is in
> >command
> >+ * format and it will be used for configuring the peripheral registers.
> > */
> > enum dma_ctrl_flags {
> > DMA_PREP_INTERRUPT = (1 << 0),
> >@@ -195,6 +197,7 @@ enum dma_ctrl_flags {
> > DMA_PREP_CONTINUE = (1 << 4),
> > DMA_PREP_FENCE = (1 << 5),
> > DMA_CTRL_REUSE = (1 << 6),
> >+ DMA_PREP_CMD = (1 << 7),
>
> Hi Vinod/Dan,
>
> Could you please help in reviewing these DMA patches.
> I have posted QPIC NAND support patches which are dependent
> upon these DMA patches.

Please allow reasonable time for review! This patch series was sent just
before the merge window and it closed couple of days back!!

>
> https://www.spinics.net/lists/kernel/msg2545386.html
>
>
> > };
> >
> > /**
>
> --
> Abhishek Sahu

--
~Vinod