Hi Gregory, I got this information from Armada-38x functional errata document.
I can add the "marvell,mv78230-i2c" compatible string to the appropriate device tree files but the i2c-mv64xxx driver enables an additional feature (offload i2c transactions) based on the compatible string "marvell,mv78230-i2c". I am not sure if this feature (offload i2c transactions) should be enabled for Armada-38x devices. That is the reason I felt for the need of a new compatible string specifically for Armada-38x SoCs. Thanks, Kalyan ________________________________________ From: Gregory CLEMENT <gregory.clem...@free-electrons.com> Sent: Friday, 22 September 2017 7:30 p.m. To: Kalyan Kinthada Cc: devicet...@vger.kernel.org; w...@the-dreams.de; robh...@kernel.org; pawel.m...@arm.com; mark.rutl...@arm.com; ijc+devicet...@hellion.org.uk; ga...@codeaurora.org; linux-...@vger.kernel.org; linux-kernel@vger.kernel.org; Chris Packham Subject: Re: [PATCH] dt-bindings: i2c: Add armada-38x i2c binding Hi Kalyan, On ven., sept. 22 2017, Kalyan Kinthada <kalyan.kinth...@alliedtelesis.co.nz> wrote: > All armada-38x variants(380, 385, 388) SoCs have an issue > in i2c controller which violates the i2c repeated start timing. Did you had an issue with one of the SoC ? If yes what was your setting ? On my side I never managed to have this sort of issue on Armada 38x. > > This errata is fixed in the i2c-mv64xxx driver but enabled > only for devices with compatible string "marvell,mv78230-i2c". In this case why not just adding the "marvell,mv78230-i2c" as compatible string in the appropriate device tree files ? Gregory > > This patch introduces a new compatible string > "marvell,armada-38x-i2c" for the i2c controller on armada-38x SoCs > so that the workaound is enabled. > > Signed-off-by: Kalyan Kinthada <kalyan.kinth...@alliedtelesis.co.nz> > --- > Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt > b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt > index 5c30026921..fc100b6bdb 100644 > --- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt > +++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt > @@ -14,6 +14,7 @@ Required properties : > very rare, initial version of the SoC which > had broken offload support. Linux > auto-detects this and sets it appropriately. > + - "marvell,armada-38x-i2c" > - interrupts : The interrupt number > > Optional properties : > -- > 2.14.1 > -- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com
