linux-kernel - Re: [PATCH v5 02/13] mfd: add simple regmap based I2C driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Mon, 20 Jul 2020 08:43:12 +0100
From:   Lee Jones <lee.jones@...aro.org>
To:     Michael Walle <michael@...le.cc>
Cc:     linux-gpio@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-hwmon@...r.kernel.org,
        linux-pwm@...r.kernel.org, linux-watchdog@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>,
        Rob Herring <robh+dt@...nel.org>,
        Jean Delvare <jdelvare@...e.com>,
        Guenter Roeck <linux@...ck-us.net>,
        Thierry Reding <thierry.reding@...il.com>,
        Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>,
        Wim Van Sebroeck <wim@...ux-watchdog.org>,
        Shawn Guo <shawnguo@...nel.org>, Li Yang <leoyang.li@....com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Jason Cooper <jason@...edaemon.net>,
        Marc Zyngier <maz@...nel.org>, Mark Brown <broonie@...nel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Subject: Re: [PATCH v5 02/13] mfd: add simple regmap based I2C driver

On Mon, 20 Jul 2020, Michael Walle wrote:

> Am 2020-07-17 11:06, schrieb Lee Jones:
> > On Mon, 06 Jul 2020, Michael Walle wrote:
> > 
> > > There are I2C devices which contain several different functions but
> > > doesn't require any special access functions. For these kind of
> > > drivers
> > > an I2C regmap should be enough.
> > > 
> > > Create an I2C driver which creates an I2C regmap and enumerates its
> > > children. If a device wants to use this as its MFD core driver, it has
> > > to add an individual compatible string. It may provide its own regmap
> > > configuration.
> > > 
> > > Subdevices can use dev_get_regmap() on the parent to get their regmap
> > > instance.
> > > 
> > > Signed-off-by: Michael Walle <michael@...le.cc>
> > > ---
> > > Changes since v4:
> > >  - new patch. Lee, please bear with me. I didn't want to delay the
> > >    new version (where a lot of remarks on the other patches were
> > >    addressed) even more, just because we haven't figured out how
> > >    to deal with the MFD part. So for now, I've included this one.
> > > 
> > >  drivers/mfd/Kconfig          |  9 +++++++
> > >  drivers/mfd/Makefile         |  1 +
> > >  drivers/mfd/simple-mfd-i2c.c | 50
> > > ++++++++++++++++++++++++++++++++++++
> > >  3 files changed, 60 insertions(+)
> > >  create mode 100644 drivers/mfd/simple-mfd-i2c.c
> > > 
> > > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> > > index 33df0837ab41..f1536a710aca 100644
> > > --- a/drivers/mfd/Kconfig
> > > +++ b/drivers/mfd/Kconfig
> > > @@ -1162,6 +1162,15 @@ config MFD_SI476X_CORE
> > >  	  To compile this driver as a module, choose M here: the
> > >  	  module will be called si476x-core.
> > > 
> > > +config MFD_SIMPLE_MFD_I2C
> > > +	tristate "Simple regmap based I2C devices"
> > 
> > Doesn't look like tristate to me.
> > 
> > Haven't you made this builtin only?
> 
> Mh yeah, I forgot to change it to module in the driver. I don't
> know whats better though, have it tristate or just offer a boolean
> option because it should be small anyway. What do you think?
> My interrupt driver will force it to boolean anyway.

Better to give consumers the choice I think.

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