RE: [PATCHv11 2/2] dma: Add Freescale eDMA engine driver support

[Jingchang Lu]

Hi, Vinod,

    Could you please help merge this patch? We are having some other upstreaming
patches using the dma functionality pending the acceptance of the eDMA driver.
    Many thanks!

Best Regards,
Jingchang

> -----Original Message-----
> From: Lu Jingchang-B35083
> Sent: Monday, January 27, 2014 1:20 PM
> To: Lu Jingchang-B35083; vinod.koul@xxxxxxxxx
> Cc: dan.j.williams@xxxxxxxxx; arnd@xxxxxxxx; shawn.guo@xxxxxxxxxx;
> pawel.moll@xxxxxxx; mark.rutland@xxxxxxx; swarren@xxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; Wang Huan-B18965
> Subject: RE: [PATCHv11 2/2] dma: Add Freescale eDMA engine driver support
> 
> Hi, Vinod,
> 
>   Let me give some more explanation on the eDMA engine pause and
> termination here:
> The eDMA engine is a request-driven controller, it manage all channels in
> one engine and schedule them to perform each one's transfer when one's
> dma request arrive.
> When a dma request of a specific channel is received, the channel's
> appropriate TCD Parameter contents are loaded into the eDMA engine, and
> the appropriate reads and writes Perform until the minor byte transfer
> count has transferred, the number of bytes to transfer per request is
> determined by the salve's characteristics, such as the FIFO size, and the
> dma request condition is also determined by specific slave, such as FIFO
> empty.
> And to the transfer a bunch of data need many dma requests.
>   So if the dma request enable bit of a channel is cleared, there will be
> no further dma Request received by the eDMA engine, thus the channel will
> never be scheduled to run by the eDMA engine, the channel is paused,
> halted, also as stopped. If the channel need to transfer the remained
> data with the previous setting, just set the dma request enable bit, the
> transfer will complete with slave's dma request.(resume) If the
> parameters need be changed, corresponding register parameters can be
> reprogrammed, after all is ok, the dma request enable bit can be set to
> enable a new dma transfer.(terminate)
>   So is this ok and could it be merged, thanks!
> 
> 
> Best Regards,
> Jingchang
> 
> 
> > -----Original Message-----
> > From: Jingchang Lu [mailto:b35083@xxxxxxxxxxxxx]
> > Sent: Monday, January 20, 2014 5:24 PM
> > To: vinod.koul@xxxxxxxxx
> > Cc: dan.j.williams@xxxxxxxxx; arnd@xxxxxxxx; shawn.guo@xxxxxxxxxx;
> > pawel.moll@xxxxxxx; mark.rutland@xxxxxxx; swarren@xxxxxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> > devicetree@xxxxxxxxxxxxxxx; Lu Jingchang-B35083; Wang Huan-B18965
> > Subject: [PATCHv11 2/2] dma: Add Freescale eDMA engine driver support
> >
> > Add Freescale enhanced direct memory(eDMA) controller support.
> > This module can be found on Vybrid and LS-1 SoCs.
> >
> > Signed-off-by: Alison Wang <b18965@xxxxxxxxxxxxx>
> > Signed-off-by: Jingchang Lu <b35083@xxxxxxxxxxxxx>
> > Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
> > ---
> > changes in v11:
> >  Add dma device_slave_caps definition.
> >
> > changes in v10:
> >  define fsl_edma_mutex in fsl_edma_engine instead of global.
> >  minor changes of binding description.
> >
> > changes in v9:
> >  define endian's operating functions instead of macro definition.
> >  remove the filter function, using dma_get_slave_channel instead.
> >
> > changes in v8:
> >  change the edma driver according eDMA dts change.
> >  add big-endian and little-endian handling.
> >
> >  no changes in v4 ~ v7.
> >
> >  changes in v3:
> >   add vf610 edma dt-bindings namespace with prefix VF610_*.
> >
> >  changes in v2:
> >   using generic dma-channels property instead of fsl,dma-channels.
> >
> >  Documentation/devicetree/bindings/dma/fsl-edma.txt |  76 ++
> >  drivers/dma/Kconfig                                |  10 +
> >  drivers/dma/Makefile                               |   1 +
> >  drivers/dma/fsl-edma.c                             | 975
> > +++++++++++++++++++++
> >  4 files changed, 1062 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/dma/fsl-edma.txt
> >  create mode 100644 drivers/dma/fsl-edma.c