From: Ulf Hansson <ulf.hansson@linaro.org>
To: Jerome Brunet <jbrunet@baylibre.com>
Cc: DTML <devicetree@vger.kernel.org>,
Jianxin Pan <jianxin.pan@amlogic.com>,
Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
"linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
yinxin_1989@aliyun.com, Stephen Boyd <sboyd@kernel.org>,
Rob Herring <robh+dt@kernel.org>,
Anand Moon <linux.amoon@gmail.com>,
"open list:ARM/Amlogic Meson..."
<linux-amlogic@lists.infradead.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
lnykww@gmail.com
Subject: Re: [PATCH v6 2/2] mmc: host: meson-mx-sdhc: new driver for the Amlogic Meson SDHC host
Date: Tue, 5 May 2020 19:30:59 +0200 [thread overview]
Message-ID: <CAPDyKFogZgX05mPgue4UT57cTM-KVPfmoPJPf1BNJurGN+qp-g@mail.gmail.com> (raw)
In-Reply-To: <1j1rnygye6.fsf@starbuckisacylon.baylibre.com>
On Tue, 5 May 2020 at 18:05, Jerome Brunet <jbrunet@baylibre.com> wrote:
>
>
> On Tue 05 May 2020 at 10:17, Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> > [...]
> >
> >> >> > +
> >> >> > + return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
> >> >> > + onecell_data);
> >> >>
> >> >> I think registering a provider for a module that does not provide clocks
> >> >> to any other device is a bit overkill.
> >> >>
> >> >> I understand the matter is getting the per-user clk* pointer.
> >> >> Since this is the module registering the clock, you can use clk_hw->clk
> >> >> to get it.
> >> >>
> >> >> Once you have the clk* of the leaf clocks, you don't even need to keep
> >> >> track of the clk_hw* since you are using devm_
> >> >>
> >> >> Afterward, we should propably discuss with Stephen if something should
> >> >> be added in CCF to get a struct clk* from struct clk_hw*.
> >> >>
> >> >
> >> > [...]
> >> >
> >> > Hmm.
> >> >
> >> > I am not sure the above is a good idea, at all. Unless, I am
> >> > misunderstanding your point, which may be the case.
> >> >
> >> > I think above "shortcuts" could lead to abuse of the clock framework
> >> > and its internal data structures. When going forward, this could make
> >> > it unnecessary harder to maintain the clock framework.
> >> >
> >> > I know, it's not my responsibility, but from my experience with MMC
> >> > and SDIO interfaces, is that those have been too easy abuse - since
> >> > most of the data structures and interfaces have been exported. Now,
> >> > it's hard to roll back that, if you see what I mean.
> >>
> >> Indeed, it worth clarifying this first.
> >>
> >> With clk_register deprecated in favor of clk_hw_register, we are likely
> >> to see that case rise elsewhere.
> >>
> >
> > So, according to the separate discussion [1], I think we can let
> > Martin decide what option to implement at this point.
> >
> > 1. Implement the "clk_hw_get_clk()" approach. The preferred option,
> > but requires wider changes of the clock subsystem as well.
> >
> > 2. Keep the existing approach, with devm_clk_get(). I am fine with
> > this as well, we can always switch to 1) later on.
>
> I have a problem with this approach.
> The dt-bindings would include "#clock-cells = <1>" for a device that
> does not actually provide and only needs it has a temporary work around.
> Those bindings are supposed to be stable ...
I agree, the bindings need to be stable.
What is the problem of keeping "#clock-cells = <1>" around, when we
move to a clk_hw_get_clk() approach in the next step?
>
> I have proposed 2 other short term solutions, let's see how it goes
Yes, seems like we need to wait for Stephen's input then.
Kind regards
Uffe
_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
next prev parent reply other threads:[~2020-05-05 17:31 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-28 21:02 [PATCH v6 0/2] Amlogic 32-bit Meson SoC SDHC MMC controller driver Martin Blumenstingl
2020-04-28 21:02 ` [PATCH v6 1/2] dt-bindings: mmc: Document the Amlogic Meson SDHC MMC host controller Martin Blumenstingl
2020-04-28 21:02 ` [PATCH v6 2/2] mmc: host: meson-mx-sdhc: new driver for the Amlogic Meson SDHC host Martin Blumenstingl
2020-04-30 9:47 ` Jerome Brunet
2020-04-30 11:10 ` Ulf Hansson
2020-04-30 12:04 ` Jerome Brunet
2020-05-05 8:17 ` Ulf Hansson
2020-05-05 16:05 ` Jerome Brunet
2020-05-05 17:30 ` Ulf Hansson [this message]
2020-05-10 20:52 ` Martin Blumenstingl
2020-05-12 7:09 ` Jerome Brunet
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAPDyKFogZgX05mPgue4UT57cTM-KVPfmoPJPf1BNJurGN+qp-g@mail.gmail.com \
--to=ulf.hansson@linaro.org \
--cc=devicetree@vger.kernel.org \
--cc=jbrunet@baylibre.com \
--cc=jianxin.pan@amlogic.com \
--cc=linux-amlogic@lists.infradead.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mmc@vger.kernel.org \
--cc=linux.amoon@gmail.com \
--cc=lnykww@gmail.com \
--cc=martin.blumenstingl@googlemail.com \
--cc=robh+dt@kernel.org \
--cc=sboyd@kernel.org \
--cc=yinxin_1989@aliyun.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).