Re: [PATCH v3 3/7] mfd: Add MFD driver for ATC260x PMICs

From: Lee Jones <lee.jones@linaro.org>
To: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
Cc: "Rob Herring" <robh+dt@kernel.org>,
	"Dmitry Torokhov" <dmitry.torokhov@gmail.com>,
	"Sebastian Reichel" <sre@kernel.org>,
	"Mark Brown" <broonie@kernel.org>,
	"Manivannan Sadhasivam" <manivannan.sadhasivam@linaro.org>,
	"Liam Girdwood" <lgirdwood@gmail.com>,
	"Andreas Färber" <afaerber@suse.de>,
	linux-actions@lists.infradead.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-input@vger.kernel.org,
	linux-pm@vger.kernel.org
Subject: Re: [PATCH v3 3/7] mfd: Add MFD driver for ATC260x PMICs
Date: Mon, 21 Dec 2020 08:10:15 +0000	[thread overview]
Message-ID: <20201221081015.GA4825@dell> (raw)
In-Reply-To: <20201218160710.GA134686@BV030612LT>

On Fri, 18 Dec 2020, Cristian Ciocaltea wrote:

> On Fri, Dec 18, 2020 at 01:21:39PM +0000, Lee Jones wrote:
> > On Fri, 18 Dec 2020, Cristian Ciocaltea wrote:
> > 
> > > Hi Lee,
> > > 
> > > Thank you for the detailed review!
> > > 
> > > I will prepare a new revision, but there are still a couple of open
> > > points..
> > 
> > Could you please snip your replies, leaving only the open points.
> > 
> > Scrolling through lots of empty quotes or "done" comments is quite
> > time consuming.  Thanks.
> 
> Sure, I'll take that into account.
> 
> > [...]
> > 
> > > > > +	ret = regmap_read(atc260x->regmap, atc260x->rev_reg, &chip_rev);
> > > > > +	if (ret) {
> > > > > +		dev_err(dev, "Failed to get chip revision\n");
> > > > > +		return ret;
> > > > > +	}
> > > > > +
> > > > > +	if (chip_rev < 0 || chip_rev > 31) {
> > > > > +		dev_err(dev, "Unknown chip revision: %d\n", ret);
> > > > > +		return -EINVAL;
> > > > > +	}
> > > > 
> > > > This still seems limiting.
> > > 
> > > This is based on the vendor implementation. Unfortunately I don't have
> > > access to a data sheet or any other source of information about the
> > > management of the chip revisions.
> > 
> > So which versions does this driver work with?  All 32?
> 
> I'm not even sure there are so many revisions, I guess that's just a
> rough validation for a vendor reserved range.
> 
> For the moment, the only place where the functionality is affected
> by the chip revision is in the regulator driver - there is a special
> handling for the ATC2603C rev.B chip variant.
> 
> I expect some additional handling might be required for new drivers
> bringing support for the other functions provided by the hardware.

The current patch seems to insinuate that 32 versions are currently
supported.  What is the chip_rev for the ATC2603C rev.B?

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog