linux-kernel - Re: [PATCH 3/4] usb: typec: tcpci_maxim: configure charging & data paths

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Date:   Tue, 16 Mar 2021 15:02:51 -0700
From:   Badhri Jagan Sridharan <badhri@...gle.com>
To:     Heikki Krogerus <heikki.krogerus@...ux.intel.com>
Cc:     Guenter Roeck <linux@...ck-us.net>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Rob Herring <robh+dt@...nel.org>,
        USB <linux-usb@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Kyle Tso <kyletso@...gle.com>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@...r.kernel.org>
Subject: Re: [PATCH 3/4] usb: typec: tcpci_maxim: configure charging & data paths

On Thu, Mar 11, 2021 at 9:08 PM Badhri Jagan Sridharan
<badhri@...gle.com> wrote:
>
> On Thu, Mar 11, 2021 at 5:33 AM Heikki Krogerus
> <heikki.krogerus@...ux.intel.com> wrote:
> >
> > Hi,
> >
> > On Thu, Mar 11, 2021 at 02:03:12AM -0800, Badhri Jagan Sridharan wrote:
> > > This change allows the driver to configure input current/voltage
> > > limit for the charging path. The driver sets current_max and voltage_max
> > > values of the power supply identified through chg-psy-name.
> > >
> > > The change also exposes the data_role and the orientation as a extcon
> > > interface for configuring the USB data controller.
> >
> > This looks wrong to me. Why wouldn't you just register your device as
> > a separate psy that supplies your charger (which is also a psy, right)?
>
> Hi Heikki,
>
> Looks like that would pretty much make it reflect the same values as
> "tcpm-source-psy-" exposed
> by tcpm. So experimenting with making the charger power supply a supplicant.
> However, noticed that the "tcpm-source-psy-" does not have calls to
> power_supply_changed().
> So the notifiers are not getting invoked.
> Trying to fix that to see if just "tcpm-source-psy-" helps the case
> without me trying to create another
> one which almost would reflect the same values. Let me know if you
> think that might not work.
Hi Heikki,

With "[PATCH] usb: typec: tcpm: Invoke power_supply_changed for
tcpm-source-psy-"
which I just sent, "tcpm-source-psy-" seems to do the job. So the
set/get_current_limit
and pd_capable callbacks are not needed. Please do review
"[PATCH] usb: typec: tcpm: Invoke power_supply_changed for tcpm-source-psy-".

Thanks,
Badhri

>
> For now, refactored the patches to only include changes related to
> data path and sending
> them in. Will follow up with patches for the charger path once I am
> done with the above approach
> and some validation.
>
> Thanks,
> Badhri
> >
> >
> > thanks,
> >
> > --
> > heikki