[PATCH v1 1/1] misc: extcon: add MAX14526 MUIC support

[Tim Harvey]

On Thu, Apr 20, 2023 at 9:54 AM Svyatoslav Ryhel <clamor95 at gmail.com> wrote:
>
> чт, 20 квіт. 2023 р. о 19:30 Simon Glass <sjg at chromium.org> пише:
> >
> > Hi Svyatoslav,
> >
> > On Thu, 20 Apr 2023 at 18:01, Svyatoslav Ryhel <clamor95 at gmail.com> wrote:
> > >
> > > чт, 20 квіт. 2023 р. о 01:41 Simon Glass <sjg at chromium.org> пише:
> > > >
> > > > Hi Svyatoslav,
> > > >
> > > > On Wed, 19 Apr 2023 at 12:53, Svyatoslav Ryhel <clamor95 at gmail.com> wrote:
> > > > >
> > > > > MAX14526 is a powerful extcon chip which allows detection of various
> > > > > plugs like usb, mhl, uart, headset etc. This version of driver
> > > > > implements support of AP-usb and CP-usb/uart paths.
> > > > >
> > > > > Tested-by: Andreas Westman Dorcsak <hedmoo at yahoo.com> # LG P880 T30
> > > > > Tested-by: Svyatoslav Ryhel <clamor95 at gmail.com> # LG P895 T30
> > > > > Signed-off-by: Svyatoslav Ryhel <clamor95 at gmail.com>
> > > > > ---
> > > > >  drivers/misc/Kconfig                  |   2 +
> > > > >  drivers/misc/Makefile                 |   1 +
> > > > >  drivers/misc/extcon/Kconfig           |   8 ++
> > > > >  drivers/misc/extcon/Makefile          |   2 +
> > > > >  drivers/misc/extcon/extcon-max14526.c | 153 ++++++++++++++++++++++++++
> > > > >  5 files changed, 166 insertions(+)
> > > > >  create mode 100644 drivers/misc/extcon/Kconfig
> > > > >  create mode 100644 drivers/misc/extcon/Makefile
> > > > >  create mode 100644 drivers/misc/extcon/extcon-max14526.c
> > > > >
> > > > > diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> > > > > index 4e1ae03e9f..1b49f3cf72 100644
> > > > > --- a/drivers/misc/Kconfig
> > > > > +++ b/drivers/misc/Kconfig
> > > > > @@ -659,4 +659,6 @@ config SL28CPLD
> > > > >           the base driver which provides common access methods for the
> > > > >           sub-drivers.
> > > > >
> > > > > +source "drivers/misc/extcon/Kconfig"
> > > > > +
> > > > >  endmenu
> > > > > diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
> > > > > index 3b792f2a14..6d4fc8ddf9 100644
> > > > > --- a/drivers/misc/Makefile
> > > > > +++ b/drivers/misc/Makefile
> > > > > @@ -87,3 +87,4 @@ obj-$(CONFIG_K3_AVS0) += k3_avs.o
> > > > >  obj-$(CONFIG_ESM_K3) += k3_esm.o
> > > > >  obj-$(CONFIG_ESM_PMIC) += esm_pmic.o
> > > > >  obj-$(CONFIG_SL28CPLD) += sl28cpld.o
> > > > > +obj-y += extcon/
> > > > > diff --git a/drivers/misc/extcon/Kconfig b/drivers/misc/extcon/Kconfig
> > > > > new file mode 100644
> > > > > index 0000000000..99c38224f3
> > > > > --- /dev/null
> > > > > +++ b/drivers/misc/extcon/Kconfig
> > > > > @@ -0,0 +1,8 @@
> > > > > +config EXTCON_MAX14526
> > > > > +       bool "Maxim MAX14526 EXTCON Support"
> > > > > +       select DM_I2C
> > > > > +       select DM_MISC
> > > > > +       help
> > > > > +         If you say yes here you get support for the MUIC device of
> > > > > +         Maxim MAX14526. The MAX14526 MUIC is a USB port accessory
> > > > > +         detector and switch.
> > > > > diff --git a/drivers/misc/extcon/Makefile b/drivers/misc/extcon/Makefile
> > > > > new file mode 100644
> > > > > index 0000000000..f012b688ce
> > > > > --- /dev/null
> > > > > +++ b/drivers/misc/extcon/Makefile
> > > > > @@ -0,0 +1,2 @@
> > > > > +# SPDX-License-Identifier: GPL-2.0+
> > > > > +obj-$(CONFIG_EXTCON_MAX14526) += extcon-max14526.o
> > > > > diff --git a/drivers/misc/extcon/extcon-max14526.c b/drivers/misc/extcon/extcon-max14526.c
> > > > > new file mode 100644
> > > > > index 0000000000..c8505dae49
> > > > > --- /dev/null
> > > > > +++ b/drivers/misc/extcon/extcon-max14526.c
> > > > > @@ -0,0 +1,153 @@
> > > > > +// SPDX-License-Identifier: GPL-2.0+
> > > > > +/*
> > > > > + * Copyright (c) 2022 Svyatoslav Ryhel <clamor95 at gmail.com>
> > > > > + *
> > > > > + * U-boot lacks extcon DM.
> > > >
> > > > In that case I think it is best to add a new uclass for it.
> > > >
> > > > Regards,
> > > > Simon
> > >
> > > Thank you, Simon!
> > >
> > > First of all, thanks for your reviews, all of them apart from those I have
> > > responded to are fairly reasonable and will be implemented.
> > >
> > > About extcon uclass. My vision is to leave this driver as is in misc for
> > > some time and check if there will be any other extcon devices added.
> > > In case these devices become at least sometimes used on supported
> > > devices there will be good reasons to create a new uclass. As for now,
> > > it is a bit pointless to waste time for a new uclass and new framework for
> > > only one device used by one board.
> >
> > I am sure there will be more.
> >
> > The problem with accepting this patch as is, is that the burden of
> > creating the uclass (which is actually not that large at all) falls on
> > the second driver submitter, as well as the burden of converting your
> > driver. In practice what happens is that no one can be bothered.
> >
> > See UCLASS_PCH for a simple uclass. You just need to define the API
> > (which may just be empty), any uclass-private struct then add
> > something to test.dst and a simple test to test/dm/extcon.c
> >
> > Regards
> >
> > Simon
>
> Ok, I will look into this a bit deeper

Svyatoslav,

I agree with Simon and would like to see a uclass. We do have the need
for a U-Boot driver that supports gpio based USB ID such as Linux
drivers/usb/common/usb-conn-gpio.c (compatible "gpio-usb-b-connector")
and drivers/extcon/extcon-usb-gpio.c (compatible
"linux,extcon-usb-gpio") (which I believe is deprecated) as there are
many usb controllers that use this that appear unsupported for
role-switch in U-Boot today.

Best Regards,

Tim