Re: [PATCH v4 05/15] pinctrl: add a pincontrol driver for BCM6328

From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: "Álvaro Fernández Rojas" <noltari@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>,
	Rob Herring <robh+dt@kernel.org>,
	Michael Walle <michael@walle.cc>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>,
	 Florian Fainelli <f.fainelli@gmail.com>,
	 bcm-kernel-feedback-list <bcm-kernel-feedback-list@broadcom.com>,
	 Jonas Gorski <jonas.gorski@gmail.com>,
	Necip Fazil Yildiran <fazilyildiran@gmail.com>,
	 "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
	devicetree <devicetree@vger.kernel.org>,
	 Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	 linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v4 05/15] pinctrl: add a pincontrol driver for BCM6328
Date: Thu, 4 Mar 2021 17:36:31 +0200	[thread overview]
Message-ID: <CAHp75VeNqF+38srodSvVXwJZ80n7RxkD-X9tiMGRK_KrQYo0gw@mail.gmail.com> (raw)
In-Reply-To: <0A8F3739-E4A2-499F-8B25-C35CF6F811ED@gmail.com>

On Thu, Mar 4, 2021 at 5:33 PM Álvaro Fernández Rojas <noltari@gmail.com> wrote:
> > El 4 mar 2021, a las 16:25, Andy Shevchenko <andy.shevchenko@gmail.com> escribió:
> > On Thu, Mar 4, 2021 at 2:25 PM Álvaro Fernández Rojas <noltari@gmail.com> wrote:
> >>> El 4 mar 2021, a las 13:12, Andy Shevchenko <andy.shevchenko@gmail.com> escribió:
> >>> On Thu, Mar 4, 2021 at 1:13 PM Álvaro Fernández Rojas <noltari@gmail.com> wrote:
> >>>>> El 4 mar 2021, a las 11:49, Andy Shevchenko <andy.shevchenko@gmail.com> escribió:
> >>>>> On Thu, Mar 4, 2021 at 10:57 AM Álvaro Fernández Rojas
> >>>>> <noltari@gmail.com> wrote:
> >
> > ...
> >
> >>>>>> +               BCM6328_MUX_LO_REG,
> >>>>>> +               BCM6328_MUX_HI_REG,
> >>>>>
> >>>>>> +               BCM6328_MUX_OTHER_REG
> >>>>>
> >>>>> When it's not terminator add a comma, otherwise remove a comma.
> >>>
> >>>> … so you want me to add a comma or not?
> >>>
> >>> Hmm... you tell me! If this is a list which covers all possible cases
> >>> _and_ the last one is the kinda maximum value (aka terminator), then
> >>> comma is not needed, otherwise add it (to me feels like the latter
> >>> should be done here).
> >>
> >> Well… Then it shouldn’t be needed, since this is a list which covers all possible cases and the last one is a terminator.
> >
> > Honestly the name suggests otherwise. And looking into the code there
> > is no guarantee you won't split that _OTHER_ area to something with
> > new compatible hardware.
>
> Every BCM63XX device has its own specific pin controllers.
> It seems that on every new SoC created by Broadcom they decided that the previous pin controller approach was a bad decision or something xD.
> Therefore I don’t think there will be such “new compatible hardware”...
>
> > Renaming to BCM6328_MUX_MAX_REG will clear that this is terminator,
> > but it means its value shouldn't be used except as to understand the
> > amount of supported registers of this enumerator.
>
> No, I don’t think this is a good idea.
> Please, take a look at:
> https://github.com/jameshilliard/gfiber-gflt100/blob/b292e8c271addbda62104bece90e3c8018714194/shared/opensource/include/bcm963xx/6328_map_part.h#L410-L441
> As you can see, BCM6328_MUX_LO_REG and BCM6328_MUX_HI_REG are used for specific GPIOs, but BCM6328_MUX_OTHER_REG is used for pins which lack a direct GPIO assignment.

Understood. Thanks for elaboration. Go ahead with current approach, thanks!

-- 
With Best Regards,
Andy Shevchenko

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel