Re: [RFC PATCH 00/13] DMA Engine support for AM33xx

[Matt Porter <mporter@ti.com>]

On Mon, Sep 24, 2012 at 11:26:55AM +0000, Hebbar, Gururaja wrote:
> On Fri, Sep 21, 2012 at 23:52:11, Porter, Matt wrote:
> > On Fri, Sep 21, 2012 at 08:27:07AM +0000, Hebbar, Gururaja wrote:
> > > On Thu, Sep 20, 2012 at 20:13:33, Porter, Matt wrote:
> > > > This series adds DMA Engine support for AM33xx, which uses
> > > > an EDMA DMAC. The EDMA DMAC has been previously supported by only
> > > > a private API implementation (much like the situation with OMAP
> > > > DMA) found on the DaVinci family of SoCs.
> > > > 
> > > > There are a mind-boggling number of dependencies for this series:
> > > > 
> > > > 	- Jon Hunter's OF DMA helpers series
> > > > 	  https://patchwork.kernel.org/patch/1461061/
> > > > 	  https://patchwork.kernel.org/patch/1461051/
> > > > 	- Patch to address OF DMA helpers naming issues:
> > > > 	  https://patchwork.kernel.org/patch/1477921/
> > > > 	- EDMA DMA Engine wrapper driver in linux-next
> > > > 	  c2dde5f8f2095d7c623ff3565c1462e190272273
> > > > 	- EDMA DMA Engine wrapper driver bug fix:
> > > > 	  https://patchwork.kernel.org/patch/1474411/  
> > > > 	- A huge number of patches in linux-next for AM33xx boot
> > > > 	  (too numerous to list)
> > > > 
> > > > The approach taken is similar to how OMAP DMA is being converted to
> > > > DMA Engine support. With the functional EDMA private API already
> > > > existing in mach-davinci/dma.c, we first move that to an ARM common
> > > > area so it can be shared. Adding DT and runtime PM support to the
> > > > private EDMA API implementation allows it to run on AM33xx. AM33xx
> > > > *only* boots using DT so we leverage Jon's generic DT DMA helpers to
> > > > register EDMA DMAC with the of_dma framework and then add support
> > > > for calling the dma_request_slave_channel() API to both the mmc
> > > > and spi drivers.
> > > > 
> > > > What works? Well, with this series we now have MMC and SPI support
> > > > on AM33xx. The only caveat for MMC is that the mmc3 controller has
> > > > its events on the crossbar and is not usable right now.
> > > > 
> > > > This is tested on BeagleBone with a SPI framebuffer driver and SD
> > > > card.
> > > > 
> > > > After this series, the plan is to convert the last in-tree user
> > > > of the private EDMA API (davinci-pcm/mcasp) and then eliminate
> > > > the private EDMA API by folding its functionality into
> > > > drivers/dma/edma.c.
> > > > 
> > > > TODO:
> > > > 	add AM33xx crossbar support to the private EDMA API
> > > > 	(any EDMA events on the crossbar are not supported)
> > > > 
> > > 
> > > 
> > > Can you please mention the base repo you have taken as starting point.
> > > (repo + extra patches ...).
> > 
> > It's mainline 3.6-rc6 and you can see the complete set of patches
> > at https://github.com/ohporter/linux/tree/edma-dmaengine-am33xx-rfc-v1
> > after commit 5698bd757d55b1bb87edd1a9744ab09c142abfc2

> 
> Thanks for the link. However, I was looking for the mainline kernel repo/branch
> That you first used as baseline. 

Linus 3.6-rc6 is the baseline. This inital version was created before any
of the am33xx base support patches got pulled to linux-next. v2 is being
rebased against that to slim down the stack of patches necessary for
testing.

> > > This will help us to test the code.
> > > 
> > > This is because I looked at the patch 12/13 and I see that mmc
> > > device-node is modified. But in mainline I don’t see device 
> > > node for mmc (yet).
> > 
> > Oops. You'll need e62a3333ae450bcdefbe22229d7bc277ae0ef645 and
> > fe97304557d2c6f7d0aaf1ea028ea48ffca366a9 which I forgot to include
> > in this series. I'll have them in for v2.
> > 
> > -Matt
> > 
> > > > Matt Porter (13):
> > > >   ARM: davinci: move private EDMA API to arm/common
> > > >   ARM: edma: remove unused transfer controller handlers
> > > >   ARM: edma: add DT and runtime PM support for AM335x
> > > >   dmaengine: edma: enable build for AM335x
> > > >   dma: Add TI EDMA device tree binding
> > > >   ARM: omap: add hsmmc am33xx specific init
> > > >   mmc: omap_hsmmc: dma_request_slave_channel() support for DT platforms
> > > >   mmc: omap_hsmmc: limit max_segs with the EDMA DMAC
> > > >   mmc: omap_hsmmc: add generic DMA request support to the DT binding
> > > >   spi: omap2-mcspi: dma_request_slave_channel() support for DT
> > > >     platforms
> > > >   spi: omap2-mcspi: add generic DMA request support to the DT binding
> > > >   ARM: dts: add am33xx EDMA support
> > > >   Documentation: add schedule for removing private EDMA API
> > > > 
> > > >  Documentation/devicetree/bindings/dma/ti-edma.txt  |   49 +
> > > >  .../devicetree/bindings/mmc/ti-omap-hsmmc.txt      |   25 +-
> > > >  Documentation/devicetree/bindings/spi/omap-spi.txt |   27 +-
> > > >  Documentation/feature-removal-schedule.txt         |   10 +
> > > >  arch/arm/Kconfig                                   |    1 +
> > > >  arch/arm/boot/dts/am33xx.dtsi                      |   46 +
> > > >  arch/arm/common/Kconfig                            |    3 +
> > > >  arch/arm/common/Makefile                           |    1 +
> > > >  arch/arm/common/edma.c                             | 1779 ++++++++++++++++++++
> > > >  arch/arm/include/asm/mach/edma.h                   |  267 +++
> > > >  arch/arm/mach-davinci/Makefile                     |    2 +-
> > > >  arch/arm/mach-davinci/devices.c                    |    3 +-
> > > >  arch/arm/mach-davinci/dm355.c                      |    2 +-
> > > >  arch/arm/mach-davinci/dm365.c                      |    2 +-
> > > >  arch/arm/mach-davinci/dm644x.c                     |    2 +-
> > > >  arch/arm/mach-davinci/dm646x.c                     |    2 +-
> > > >  arch/arm/mach-davinci/dma.c                        | 1588 -----------------
> > > >  arch/arm/mach-davinci/include/mach/asp.h           |    2 +-
> > > >  arch/arm/mach-davinci/include/mach/da8xx.h         |    3 +-
> > > >  arch/arm/mach-davinci/include/mach/edma.h          |  267 ---
> > > >  arch/arm/mach-davinci/include/mach/spi.h           |    2 +-
> > > >  arch/arm/mach-omap2/hsmmc.c                        |    7 +-
> > > >  arch/arm/plat-omap/Kconfig                         |    1 +
> > > >  drivers/dma/Kconfig                                |    2 +-
> > > >  drivers/dma/edma.c                                 |    2 +-
> > > >  drivers/mmc/host/omap_hsmmc.c                      |   26 +-
> > > >  drivers/spi/spi-omap2-mcspi.c                      |   68 +-
> > > >  27 files changed, 2296 insertions(+), 1893 deletions(-)
> > > >  create mode 100644 Documentation/devicetree/bindings/dma/ti-edma.txt
> > > >  create mode 100644 arch/arm/common/edma.c
> > > >  create mode 100644 arch/arm/include/asm/mach/edma.h
> > > >  delete mode 100644 arch/arm/mach-davinci/dma.c
> > > >  delete mode 100644 arch/arm/mach-davinci/include/mach/edma.h
> > > > 
> > > > -- 
> > > > 1.7.9.5
> > > > 
> > > > _______________________________________________
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> > > > Davinci-linux-open-source@linux.davincidsp.com
> > > > http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
> > > > 
> > > 
> > > 
> > > Regards, 
> > > Gururaja
> > > _______________________________________________
> > > Davinci-linux-open-source mailing list
> > > Davinci-linux-open-source@linux.davincidsp.com
> > > http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
> > 
> 
> 
> Regards, 
> Gururaja
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