[meta-xilinx] Kernel version, xilinx git repo, yocto kernel

[Arno Steffens]

In fact, I think I have difficulties with glitches on the bus, but changes at the boards are much more expensive and time consuming - so I'll try to get a better stability with that gpio-bitbang driver.

Thanks Mike, especially for the hints with devicetree. Are this GPIO numbers are same as MIO-Pin-numbers? I found that the base-include for zynq has been changed completly (at least in my eyes), so it will take some time to adapt it to a new kernel.
I created a new bitstream (IO set to GPIO instead of I2C) and (not sure whether it is required) a new fsbl.  I don't need I2c in Uboot, but I am wondering where this gets information about it. Including driver in kernel is smallest issue. So altogether this becomes quite a project for me ;) but I hope I learn a lot with that. Did all this steps just once or twice some time ago.

> Gesendet: Freitag, 05. April 2019 um 07:44 Uhr
> Von: "Mike Looijmans" <mike.looijmans at topic.nl>
> An: "Arno Steffens" <epsi at gmx.de>
> Cc: "meta xilinx" <meta-xilinx at yoctoproject.org>
> Betreff: Re: Aw: Re: [meta-xilinx] Kernel version, xilinx git repo, yocto kernel
>
> On 04-04-19 14:03, Arno Steffens wrote:
> > Thanks Mike for this clear (and surprising) words.
> > The reason I thought it might help is that functions like this (cdns_i2c_init_recovery_info) has been added.
>
> Well if you need recovery, something is broken on the bus...
>
> > I'll check the bitbang option. Do I have to expect performance/timing issues?
> > I guess I have to adjust devicetree for that too? Phuuuuu. Thats always magic to me.
> > Kind regards, Arno
>
> Here's our devicetree that sets up the bitbank stuff:
>
> https://github.com/topic-embedded-products/linux/blob/topic-miami/arch/arm/boot/dts/topic-miami.dtsi
>
> Don't forget to activate the bitbang GPIO I2C driver in the "drivers" section
> of the kernel configuration as well.
>
> >
> >> Gesendet: Donnerstag, 04. April 2019 um 07:31 Uhr
> >> Von: "Mike Looijmans" <mike.looijmans at topic.nl>
> >> An: "Arno Steffens" <epsi at gmx.de>, "meta xilinx" <meta-xilinx at yoctoproject.org>
> >> Betreff: Re: [meta-xilinx] Kernel version, xilinx git repo, yocto kernel
> >>
> >> Simple solution would be to just stop using the cadence driver. There are
> >> issues in the Zynq that cannot really be resolved in software apparently, and
> >> the only way around them we've found is to just use a bitbang GPIO controller
> >> on the same pins. That made all problems go away.
> >>
> >> Chances are that moving to a newer kernel will not resolve your I2C issues anyway.
> >>
> >> On 03-04-19 13:53, Arno Steffens wrote:
> >>> I need a more recent kernel (Zynq 7000) and wondering, what can I do.
> >>> Why I am looking for that?
> >>> I have I2C issues and guess I need the recovery functionality, but the Cadence I2c driver that supports it is only in the current xilinx master branch. Even not in mainline 4.19.
> >>>
> >>> Before this I2C issue popped up I took a kernel.org LTS kernel and patch/take over the qspi/dma stuff that I need from the xilinx kernel. But this time it will not work. What would you recommend me?
> >>>
> >>> Just take to master branch? That will probably never work with RT patches ...
> >>> The xlx-kernel - Which kernel-org version it is based on?
> >>>
> >>> Best regards, Arno