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Message-ID: <1BAFE6F6C881BF42822005164F1491C33EA8FDA9@DBDE01.ent.ti.com>
Date: Wed, 26 Sep 2012 08:26:19 +0000
From: "Hebbar, Gururaja" <gururaja.hebbar@...com>
To: "Porter, Matt" <mporter@...com>
CC: Tony Lindgren <tony@...mide.com>, "Nori, Sekhar" <nsekhar@...com>,
Grant Likely <grant.likely@...retlab.ca>,
Mark Brown <broonie@...nsource.wolfsonmicro.com>,
"Cousson, Benoit" <b-cousson@...com>,
Russell King <linux@....linux.org.uk>,
Vinod Koul <vinod.koul@...el.com>,
Rob Landley <rob@...dley.net>, Chris Ball <cjb@...top.org>,
Linux DaVinci Kernel List
<davinci-linux-open-source@...ux.davincidsp.com>,
Arnd Bergmann <arnd@...db.de>,
Linux Documentation List <linux-doc@...r.kernel.org>,
Devicetree Discuss <devicetree-discuss@...ts.ozlabs.org>,
Linux MMC List <linux-mmc@...r.kernel.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
Rob Herring <rob.herring@...xeda.com>,
Dan Williams <djbw@...com>,
Linux SPI Devel List
<spi-devel-general@...ts.sourceforge.net>,
Linux OMAP List <linux-omap@...r.kernel.org>,
Linux ARM Kernel List <linux-arm-kernel@...ts.infradead.org>
Subject: RE: [RFC PATCH 00/13] DMA Engine support for AM33xx
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
>
> > 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.
Yesterday I tested edma patches on latest linux-next/master + merge of
linux-omap/for_3.7/dts_part2. Below are my observations
1. baseline = linux-next/master + merge of linux-omap/for_3.7/dts_part2
2. on top of above branch, I applied patches [1-9]/13 of your edma
patches
3. few patches required trivial changes before applying
4. Applied dma of patches as you mentioned
5. add custom patch (ARM: CUSTOM: Build a uImage with dtb already
appended)
From https://github.com/hvaibhav/am335x-linux/commit/
7e72f5ed4b702c9373d19f7626f07ae31a381d53#arch/arm/Makefile
6. Modified 9/13 patch to apply properly on latest am33xx.dtsi.
a. Edma portion as it is
b. mmc portion as below
mmc1: mmc@...60000 {
compatible = "ti,omap3-hsmmc";
ti,hwmods = "mmc1";
ti,dual-volt;
ti,needs-special-reset;
bus-width = <4>;
vmmc-supply = <&vmmc_reg>;
dmas = <&edma 24
&edma 25>;
dma-names = "tx", "rx";
};
c. added mmc pinmux as-well
7. make CROSS_COMPILE=arm-arago-linux-gnueabi- ARCH=arm distclean
make CROSS_COMPILE=arm-arago-linux-gnueabi- ARCH=arm
omap2plus_defconfig
8. enabled TI_EDMA from menuconfig (since it was not enabled for
omap2plus_defconfig
9. make CROSS_COMPILE=arm-arago-linux-gnueabi- ARCH=arm uImage
make CROSS_COMPILE=arm-arago-linux-gnueabi- ARCH=arm
uImage-dtb.am335x-evm
With above changes, edma probe was failing at request_mem_region()
Inside linux-next/arch/arm/common/edma.c --> edma_probe()
I had to modify edma_probe as below
diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
index f337f81..efe2673 100644
--- a/arch/arm/common/edma.c
+++ b/arch/arm/common/edma.c
@@ -1589,11 +1589,11 @@ static int __init edma_probe(struct platform_device *pdev)
for (j = 0; j < EDMA_MAX_CC; j++) {
if (node) {
int err;
- err = of_address_to_resource(node, 0, &res[j]);
+ err = of_address_to_resource(node, j, &res[j]);
if (err) {
dev_err(dev,
"unable to find 'reg' property\n");
- return -EIO;
+ //return -EIO;
}
r[j] = &res[j];
With this I was able to boot on am335x-evm and do a successful MMC
copy-md5sum-compare test.
I believe you are looking into above issue in your v2 version.
>
> -Matt
>
...snip...
...snip...
...snip...
Regards,
Gururaja
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