RE: [PATCH v2 05/12] Document: dt: binding: imx: update pinctrl doc for imx6sll

From: Jacky Bai <ping.bai@nxp.com>
To: Shawn Guo <shawnguo@kernel.org>,
	Linus Walleij <linus.walleij@linaro.org>
Cc: Michael Turquette <mturquette@baylibre.com>,
	Stephen Boyd <sboyd@codeaurora.org>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Sascha Hauer <kernel@pengutronix.de>,
	Fabio Estevam <fabio.estevam@nxp.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Philipp Zabel <p.zabel@pengutronix.de>,
	linux-clk <linux-clk@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	"jacky.baip@gmail.com" <jacky.baip@gmail.com>,
	Anson Huang <anson.huang@nxp.com>
Subject: RE: [PATCH v2 05/12] Document: dt: binding: imx: update pinctrl doc for imx6sll
Date: Mon, 23 Jan 2017 07:17:30 +0000	[thread overview]
Message-ID: <AM3PR04MB530E214A598B06ECFFE551487720@AM3PR04MB530.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <20170123060454.GD5662@dragon>

> From: Shawn Guo [mailto:shawnguo@kernel.org]
> > >>
> > >> > Another thing is that we can use a pins-tool program developed by
> > >> > NXP to  generate the pinctrl configuration code that can be used
> > >> > directly in dts. This tiny program can avoid pin function
> > >> > conflict. As on i.MX, there are so may pins, each pin can be used for up 8
> function.
> > >> > Configuring the pins is a time-consuming work.  This tools is
> > >> > very useful for
> > >> customer to generate the dts code.
> > >>
> > >> I understand, but every silicon vendor has such a tool, all are
> > >> different, proprietary and unfriendly to programmers and open
> > >> source developers, who need to understand how the hardware is
> > >> working without magic tools and secret data sheets to fix bugs.
> > >>
> > >> For the people working with maintaining the code it is paramount
> > >> that DTS files are self-descriptive.
> > >
> > > OK.  Thanks for your comments.  Adding generic-pinconf in imx
> > > pinctrl needs some time to finish and the legacy method still need be here
> even if generic-pinconf is added.
> > > Do you plan to pick this legacy binding patch for now?
> >
> > As I said earlier:
> >
> > > atleast I need an indication from one of the i.MX maintainers how
> > > they want to proceed.
> 
> Sorry for being late for the discussion.
> 
> To be honest, I did not really expect so many i.MX6 variants coming to us.  Just
> out of curiosity, are there any more in the pipeline to come, or is this the last
> known one?
> 

AFAIK, this should be the last variant of i.MX6. But not the last one of i.MX family.

> I understand that there are now more generic support available at pinctrl core
> level for us to use than the time we initial designed i.MX pinctrl driver.  But I
> intend to agree with Jacky that imx6sll can be supported by the existing driver,
> since it doesn't require any additional driver changes.
> 
> If any new generation of i.MX family require changes on the existing pinctrl
> driver, we should probably push back for a redesign to use generic support as
> much as possible.  @Jacky, how does i.MX8 pinctrl look like?  How same or
> different as/from i.MX6 pinctrl?
> 

i.MX8 kernel support is in development stage. The code has not been finalized.
For now, i.MX8 shares most of the pinctrl code with i.MX6 and use the same pinconfig method.

> Just my opinion.
> 
> Shawn