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From: Michal Simek <>
To: Michal Simek <>,
	Linus Walleij <>
Cc: "" <>,
	Michal Simek <>,
	Steffen Trumtrar <>,
	Peter Crosthwaite <>,
	"open list:GPIO SUBSYSTEM" <>,
	Rob Herring <>,
	Linux ARM <>
Subject: Re: [PATCH] gpio: zynq: Setup chip->base based on alias ID
Date: Tue, 15 May 2018 15:26:40 +0200	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

Hi Linus,

On 2.5.2018 16:19, Michal Simek wrote:
> On 2.5.2018 15:56, Linus Walleij wrote:
>> On Wed, May 2, 2018 at 3:41 PM, Michal Simek <> wrote:
>>> If you don't want this patch I understand that and it will become just
>>> another soc vendor patch out of mainline.
>> I don't really know what to do, so that is why I'm discussing.
> me too. It is also interesting that I have met with the case with
> zynq/zynqmp gpio driver and not gpio-xilinx.c which can have a lot of
> instances.
>> It's one of those gray areas.
>> From one point of view there is the purist stance that we should
>> only support what the mainline tree does, and be strict and
>> consistent so we don't accumulate to many nasty hacks.
> Also this expect that the first patch does everything right which is not
> truth all the time.
>> On the other hand, it is completely possible that all users of this
>> particular driver actually must have this patch, and then I just
>> push them to use a deviant vendor tree for no good reason.
>> Would it be possible that I apply the patch, and somehow also
>> establish some understanding with all users of the Xilinx
>> platform that whatever legacy applications are out there
>> must start to migrate towards using the character device so
>> this reliance on the numberspace doesn't stick around forever?
> When someone contacts me for asking guidance for gpio I am telling them
> not to use legacy sysfs interface and use libgpiod. Last one was a week
> ago in connection to Ultra96 and libmraa.
> But even chardev is not supported there now.
>> For example can we make a patch to some systems like
>> arch/arm/boot/dts/zynq-*.dts
>> adding proper GPIO line names to these device trees, such
>> as was made in e.g. commit f6b1674d570aa1
>> "arm64: dts: qcom: sbc: Name GPIO lines"
> If you take a look at
> arch/arm64/boot/dts/xilinx/zynqmp-zcu100-revC.dts
> which is Ultra96 board gpio-line-names are filled there for the whole PS
> part. Definitely take a look and let know if you find out any issue there.
> zynq/zynqmp gpio controller contains PS pins (hard part) and PL pins
> coming to logic.
> I can't describe PL gpio pins because it can be whatever even I have
> done that for one fixed hw design.
> Interesting part on that sha1 you shared is how "NC" pin is described.
> gpio pin 35 I have on zcu100 as "" but it should be maybe TP_PAD which
> is really just a pad on real board. And the rest of "" gpio names are
> connected to PL.
> I am happy to take a look at existing platforms and use gpio-line-names
> there. For example arch/arm64/boot/dts/xilinx/zynqmp-zcu102-revA.dts
> I use in tca6416_u97 and u61 comments instead of this property.

Have you done any decision about this patch?


  reply	other threads:[~2018-05-15 13:27 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-11 13:55 Michal Simek
2018-04-26 13:08 ` Linus Walleij
2018-04-26 13:35   ` Michal Simek
2018-05-02 10:10     ` Linus Walleij
2018-05-02 10:15       ` Michal Simek
2018-05-02 13:01         ` Linus Walleij
2018-05-02 13:41           ` Michal Simek
2018-05-02 13:56             ` Linus Walleij
2018-05-02 14:19               ` Michal Simek
2018-05-15 13:26                 ` Michal Simek [this message]
2018-05-23  9:44                   ` Linus Walleij
2018-05-23 10:26                     ` Michal Simek
2018-05-23  9:42                 ` Linus Walleij
2018-05-23 10:17                   ` Michal Simek

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