linux-kernel - Re: [PATCH 2/3] regulator: qcom_usb_vbus: Add support for PMI8998 VBUS

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Message-ID: <20250212112510.2c7140a5@jamesmacinnes-VirtualBox>
Date: Wed, 12 Feb 2025 11:25:10 -0800
From: "James A. MacInnes" <james.a.macinnes@...il.com>
To: Caleb Connolly <caleb.connolly@...aro.org>
Cc: Mark Brown <broonie@...nel.org>, linux-arm-msm@...r.kernel.org,
 linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
 andersson@...nel.org, konradybcio@...nel.org, quic_wcheng@...cinc.com,
 robh@...nel.org, krzk+dt@...nel.org, conor+dt@...nel.org,
 lgirdwood@...il.com
Subject: Re: [PATCH 2/3] regulator: qcom_usb_vbus: Add support for PMI8998
 VBUS

On Wed, 12 Feb 2025 16:09:01 +0000
Caleb Connolly <caleb.connolly@...aro.org> wrote:

> On 2/12/25 15:37, Mark Brown wrote:
> > On Wed, Feb 12, 2025 at 03:29:54PM +0000, Caleb Connolly wrote:
> >   
> >> I would suggest implementing a proper .is_enabled op to poll the
> >> status register for OTG_STATE_ENABLED and configuring  
> > 
> > No, that would be buggy.  Implement a get_status() operation if the
> > device can report status.  is_enabled() should report what the
> > driver asked for.  
> 
> Ahh yep, that's right. it should implement .get_status() (as per the 
> polling code in _regulator_do_enable()).
> 

I am happy to implement the proper get_status() operation, but the
other half of this, the type-c driver (that is functional on the 845),
is managing the status portion. With my testing so far, I see the
regulator resets the USB hub when I remove power and then supplies from
its own battery. Is this the expected operation? As of yet, I am not
seeing any failures and the original Android driver lacked the
knowledge of the output is status.

I can dive back into the original driver and the documentation to
verify. 

Any other thoughts?

Thank you,