linux-kernel - Re: [PATCH v5 4/5] mfd: sm5703: Add support for SM5703 MFD

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Message-ID: <YsvXom7CQ8qpzR5O@google.com>
Date:   Mon, 11 Jul 2022 08:56:18 +0100
From:   Lee Jones <lee.jones@...aro.org>
To:     Markuss Broks <markuss.broks@...il.com>
Cc:     linux-kernel@...r.kernel.org, phone-devel@...r.kernel.org,
        ~postmarketos/upstreaming@...ts.sr.ht,
        Matti Vaittinen <mazziesaccount@...il.com>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>,
        MyungJoo Ham <myungjoo.ham@...sung.com>,
        Chanwoo Choi <cw00.choi@...sung.com>,
        devicetree@...r.kernel.org
Subject: Re: [PATCH v5 4/5] mfd: sm5703: Add support for SM5703 MFD

On Sat, 09 Jul 2022, Markuss Broks wrote:

> Hi Lee,
> 
> On 6/15/22 00:32, Lee Jones wrote:
> > On Sat, 23 Apr 2022, Markuss Broks wrote:
> > 
> > > Silicon Mitus SM5703 is a multi-function device, meant to be
> > Please avoid using the term MFD.
> > 
> > How is the device described in the data-sheet?
> I don't have a data-sheet for this device. The only reference I have is
> downstream Linux driver. Maybe a better way to call it would be PMIC?

Yes, if that's what this is, PMIC sounds better.

> > What do you mean by "meant to be"?
> "designed to be", it appears that this part is almost exclusively used by
> Samsung in its mobile phones.

"designed to be" sounds better.

> > > used in mobile devices. It has several modules: LDO, BUCK regulators,
> > Modules or functions?
> 
> Some of "modules" are quite separate, so I decided to call it that way. How
> should it be called?

Functions.

> > > charger circuit, flash LED driver, a fuel gauge for monitoring the battery
> > > and a MUIC USB switcher. The MUIC and fuel gauge parts are separate in that
> > > they use separate i2c lines to communicate with the device, while charger
> > "I2C"
> > 
> > > circuit, LED driver and regulators are on the main i2c line the device is
> > > controlled with.
> > > 
> > > Signed-off-by: Markuss Broks <markuss.broks@...il.com>
> > > ---
> > >   MAINTAINERS                |   8 +++
> > >   drivers/mfd/Kconfig        |  13 +++++
> > >   drivers/mfd/Makefile       |   1 +
> > >   drivers/mfd/sm5703.c       |  78 +++++++++++++++++++++++++++
> > >   include/linux/mfd/sm5703.h | 105 +++++++++++++++++++++++++++++++++++++
> > >   5 files changed, 205 insertions(+)
> > >   create mode 100644 drivers/mfd/sm5703.c
> > >   create mode 100644 include/linux/mfd/sm5703.h
> > > 
> > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > index 6157e706ed02..6125ed1a3be4 100644
> > > --- a/MAINTAINERS
> > > +++ b/MAINTAINERS
> > > @@ -18172,6 +18172,14 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev
> > >   F:	include/linux/srcu*.h
> > >   F:	kernel/rcu/srcu*.c
> > > +SM5703 MFD DRIVER
> > > +M:	Markuss Broks <markuss.broks@...il.com>
> > > +S:	Maintained
> > > +F:	Documentation/devicetree/bindings/mfd/siliconmitus,sm5703.yaml
> > > +F:	Documentation/devicetree/bindings/regulator/siliconmitus,sm5703-regulator.yaml
> > > +F:	drivers/mfd/sm5703.c
> > > +F:	drivers/regulator/sm5703-regulator.c
> > > +
> > >   SMACK SECURITY MODULE
> > >   M:	Casey Schaufler <casey@...aufler-ca.com>
> > >   L:	linux-security-module@...r.kernel.org
> > > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> > > index 3b59456f5545..c13a99ceae99 100644
> > > --- a/drivers/mfd/Kconfig
> > > +++ b/drivers/mfd/Kconfig
> > > @@ -1237,6 +1237,19 @@ config MFD_SM501
> > >   	  interface. The device may be connected by PCI or local bus with
> > >   	  varying functions enabled.
> > > +config MFD_SM5703
> > > +	tristate "Silicon Mitus SM5703 MFD"
> > > +	depends on I2C
> > > +	depends on OF
> > > +	select MFD_CORE
> > > +	select REGMAP_I2C
> > > +	help
> > > +	  This is the core driver for the Silicon Mitus SM5703 multi-function
> > Please drop the MFD term, as above.
> > 
> > > +	  device. This device is meant to be used in phones and it has numerous
> > "meant to be"?
> > 
> > > +	  modules, including LED controller, regulators, fuel gauge, MUIC and
> > Either "an LED controller" or "LED controllers"
> > 
> > Same with "charger circuit" below.
> > 
> > > +	  charger circuit. It also support muxing a serial interface over USB
> > "supports"
> > 
> > What kind of serial?
> UART as a standard Samsung debug port interface (619K Ohm resistor between
> data lines is Samsung's debug cable).

Probably best to state that then.

-- 
Lee Jones [李琼斯]
Principal Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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