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.k...@intel.com
> Cc: dan.j.willi...@intel.com; a...@arndb.de; shawn....@linaro.org;
> pawel.m...@arm.com; mark.rutl...@arm.com; swar...@wwwdotorg.org; linux-
> ker...@vger.kernel.org; linux-arm-ker...@lists.infradead.org;
> devicetree@vger.kernel.org; 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:b35...@freescale.com]
> > Sent: Monday, January 20, 2014 5:24 PM
> > To: vinod.k...@intel.com
> > Cc: dan.j.willi...@intel.com; a...@arndb.de; shawn....@linaro.org;
> > pawel.m...@arm.com; mark.rutl...@arm.com; swar...@wwwdotorg.org; linux-
> > ker...@vger.kernel.org; linux-arm-ker...@lists.infradead.org;
> > devicetree@vger.kernel.org; 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 <b18...@freescale.com>
> > Signed-off-by: Jingchang Lu <b35...@freescale.com>
> > Acked-by: Arnd Bergmann <a...@arndb.de>
> > ---
> > 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
