linux-kernel - Re: [PATCH v2 06/11] mfd: drivers: Add TI TPS65219 PMIC support

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Message-ID: <20220825091730.i7qi7lnfq44cffjh@blmsp>
Date:   Thu, 25 Aug 2022 11:17:30 +0200
From:   Markus Schneider-Pargmann <msp@...libre.com>
To:     Lee Jones <lee.jones@...aro.org>
Cc:     Jerome Neanne <jneanne@...libre.com>, lgirdwood@...il.com,
        broonie@...nel.org, robh+dt@...nel.org, nm@...com,
        kristo@...nel.org, khilman@...libre.com, narmstrong@...libre.com,
        j-keerthy@...com, linux-kernel@...r.kernel.org,
        devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        Lee Jones <lee@...nel.org>
Subject: Re: [PATCH v2 06/11] mfd: drivers: Add TI TPS65219 PMIC support

Hi Lee,

thanks for your comments. I am pushing the next version v4 for Jerome
and fixed most of your comments. Some inline comments.

On Mon, Aug 08, 2022 at 04:49:57PM +0100, Lee Jones wrote:
> On Tue, 26 Jul 2022, Jerome Neanne wrote:
> 
> > The TPS65219 is a power management IC PMIC designed
> > to supply a wide range of SoCs
> > in both portable and stationary applications.
> > Any SoC can control TPS65219 over a standard I2C interface.
> 
> Really odd line break choices here.
> 
> > It contains the following components:
> > - Regulators.
> > - Over Temperature warning and Shut down.
> > - GPIOs
> > - Multi Function Pins (MFP)
> > 
> > This patch adds support for tps65219 mfd device. At this time only
> 
> No such thing as an MFD device, what is it?  PMIC, no?
> 
> > the functionalities listed below are made available:
> > 
> > - Regulators probe and functionalities
> > - warm and cold reset support
> > - SW shutdown support
> > 
> > Signed-off-by: Jerome Neanne <jneanne@...libre.com>
> > ---
> >  MAINTAINERS                  |   1 +
> >  drivers/mfd/Kconfig          |  15 +++
> >  drivers/mfd/Makefile         |   1 +
> >  drivers/mfd/tps65219.c       | 214 +++++++++++++++++++++++++++++
> >  include/linux/mfd/tps65219.h | 251 +++++++++++++++++++++++++++++++++++
> >  5 files changed, 482 insertions(+)
> >  create mode 100644 drivers/mfd/tps65219.c
> >  create mode 100644 include/linux/mfd/tps65219.h
> > 

...

> > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> > index 858cacf659d6..a8ff3d6ea3ab 100644
> > --- a/drivers/mfd/Makefile
> > +++ b/drivers/mfd/Makefile

...

> 
> > +//
> > +// Copyright (C) 2022 BayLibre Incorporated - https://www.baylibre.com/
> > +//
> > +// This implementation derived from tps65218 authored by
> > +// "J Keerthy <j-keerthy@...com>"
> 
> Which he probably copied from elsewhere.
> 
> Please drop this line.
> 
> > +//
> 
> Drop this empty comment
> 
> Only C++ for the SPDX line please.

Mark Brown wanted this the other way around:

"Please make the entire comment a C++ one so things look more
intentional."
https://lore.kernel.org/all/YtayikFdidxXXubS@sirena.org.uk/

Let me know what I should do here.

...

> 
> > +		if (pm_power_off)
> > +			dev_warn(tps->dev, "Setup as system-power-controller but pm_power_off function already registered, overwriting\n");
> 
> Is that really what you want?
> 
> What about the other driver that thinks it's the
> system-power-controller? Seems wrong.

I am now not overwriting pm_power_off but print an error and probe
successfully.

...

> > diff --git a/include/linux/mfd/tps65219.h b/include/linux/mfd/tps65219.h
> > new file mode 100644
> > index 000000000000..e9197ab8bc75
> > --- /dev/null
> > +++ b/include/linux/mfd/tps65219.h
> > @@ -0,0 +1,251 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * linux/mfd/tps65219.h
> 
> No filenames please.  They tend to become unsynced.
> 
> > + * Functions to access TPS65219 power management chip.
> 
> As above.
> 
> > + * Copyright (C) 2022 BayLibre Incorporated - https://www.baylibre.com/
> > + */
> > +
> > +#ifndef __LINUX_MFD_TPS65219_H
> > +#define __LINUX_MFD_TPS65219_H
> 
> LINUX?

This seems to be quite common in include/linux/mfd/*.h to have
__LINUX_MFD_ as prefix (probably for the directory they are in). I am
assuming that's not the right style. What should be used instead?
__MFD_TPS65219_H or MFD_TPS65219_H or maybe something else?

...

> > +
> > +/**
> > + * struct tps65219 - tps65219 sub-driver chip access routines
> > + *
> > + * Device data may be used to access the TPS65219 chip
> > + */
> 
> This is not a complete kerneldoc header.
> 
> Please compile test with W=1.

I didn't see any errors reported for this struct with W=1. I am assuming
you meant missing field descriptions and added them.

Thanks,
Markus