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

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Date:   Thu, 11 Mar 2021 21:08:04 -0800
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 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.

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