Re: [PATCH v4] usb: dwc3: qcom: Remove extcon functionality from glue

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 7/18/25 7:38 AM, Krishna Kurapati wrote:
> Deprecate usage of extcon functionality from the glue driver. Now
> that the glue driver is a flattened implementation, all existing
> DTs would eventually move to new bindings. While doing so let them
> make use of role-switch/ typec frameworks to provide role data
> rather than using extcon. None of the existing in-kernel extcon users
> have moved to using new bindings yet, so this change doesn't affect
> any existing users.
> 
> On upstream, summary of targets/platforms using extcon is as follows:
> 
> 1. MSM8916 and MSM8939 use Chipidea controller, hence the changes have no
> effect on them.
> 
> 2. Of the other extcon users, most of them use "linux,extcon-usb-gpio"
> driver which relies on id/vbus gpios to inform role changes. This can be
> transitioned to role switch based driver (usb-conn-gpio) while flattening
> those platforms to move away from extcon and rely on role switching.
> 
> 3. The one target that uses dwc3 controller and extcon and is not based
> on reading gpios is "arch/arm64/boot/dts/qcom/msm8996-xiaomi-common.dtsi".
> This platform uses TI's Type-C Port controller chip to provide extcon. If
> usb on this platform is being flattened, then effort should be put in to
> define a usb-c-connector device in DT and make use of role switch in
> TUSB320L driver.
> 
> Signed-off-by: Krishna Kurapati <krishna.kurapati@oss.qualcomm.com>
> ---

To an external reviewer who doesn't have the context, 'flattening' doesn't
really mean much. You should instead specifically mention the existence
and purpose of dwc3-qcom-legacy.c

Konrad