Re: [PATCH v1 1/1] gpio: of: provide option generic property for initial line states

From	Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v1 1/1] gpio: of: provide option generic property for initial line states
Date	2017-06-11 22:00 +0200
Message-ID	<tRhbI-Gr-1@gated-at.bofh.it> (permalink)
References	<tQsVz-2Cx-5@gated-at.bofh.it> <tQukG-3nk-19@gated-at.bofh.it> <tR4o9-1x7-9@gated-at.bofh.it>
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Hi Oleksij,

On 06/11/2017 09:19 AM, Oleksij Rempel wrote:
> Hi Rob,
> 
> On Fri, Jun 09, 2017 at 10:41:30AM -0500, Rob Herring wrote:
>> On Fri, Jun 9, 2017 at 9:16 AM, Oleksij Rempel <o.rempel@pengutronix.de> wrote:
>>> This property is needed for barebox or may be other bootloaders
>>> to set proper gpio configuration as early as possible.
>>>
>>> This example is mainly based on "lines-initial-states" property
>>> from this binding documentation:
>>> Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt
>>
>> Don't we have a binding for this already based on gpio-hogs.
> 
> Markus Pargmann was working on this topic before and suddenly was not
> able to finish it.

that's fine, but the proposed extension is supposedly not wanted.

> I found only some not finished discussions and no code or documentation
> in linux kernel upstream.
> 
> So far, I was able to find fallowing patches and discussions:
> patch 23.08.2015, last comment 11.05.2017:
> https://patchwork.kernel.org/patch/7096721/
> 
> patch 23.02.2016, last comment 09.03.2016:
> https://patchwork.ozlabs.org/patch/586743/
> 
> Since there was objections about node-like design for gpio-initval, I
> provided an array property, which is similar to initval properties already used
> for different other device nodes. For example:
> 
> Documentation/devicetree/bindings/net/wireless/qcom,ath10k.txt
> qcom,ath10k-calibration-data
> 
> Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt
> lines-initial-states

It'd rather be better to fix the drivers and remove the properties
from these found device tree binding descriptions.

> 
> Please fixme if I miss something.

Why is GPIO hogging mechanism not good enough for your purpose?

--
With best wishes,
Vladimir

Thread

[PATCH v1 1/1] gpio: of: provide option generic property for initial line states Oleksij Rempel <o.rempel@pengutronix.de> - 2017-06-09 16:20 +0200
  Re: [PATCH v1 1/1] gpio: of: provide option generic property for  initial line states Rob Herring <robh+dt@kernel.org> - 2017-06-09 17:50 +0200
    Re: [PATCH v1 1/1] gpio: of: provide option generic property for  initial line states Oleksij Rempel <ore@pengutronix.de> - 2017-06-11 08:20 +0200
      Re: [PATCH v1 1/1] gpio: of: provide option generic property for  initial line states Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> - 2017-06-11 22:00 +0200
        Re: [PATCH v1 1/1] gpio: of: provide option generic property for  initial line states Oleksij Rempel <ore@pengutronix.de> - 2017-06-15 08:00 +0200
          Re: [PATCH v1 1/1] gpio: of: provide option generic property for  initial line states Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> - 2017-06-15 11:50 +0200

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