RE: [PATCH v4 3/4] usb: typec: mux: add "compatible" property for switch match

[Jun Li <jun.li@nxp.com>]

> -----Original Message-----
> From: Peter Chen <peter.chen@nxp.com>
> Sent: Wednesday, October 21, 2020 8:16 AM
> To: Jun Li <jun.li@nxp.com>
> Cc: heikki.krogerus@linux.intel.com; robh+dt@kernel.org;
> rafael@kernel.org; gregkh@linuxfoundation.org;
> andriy.shevchenko@linux.intel.com; hdegoede@redhat.com;
> lee.jones@linaro.org; mika.westerberg@linux.intel.com;
> dmitry.torokhov@gmail.com; prabhakar.mahadev-lad.rj@bp.renesas.com;
> laurent.pinchart+renesas@ideasonboard.com; linux-usb@vger.kernel.org;
> devicetree@vger.kernel.org; dl-linux-imx <linux-imx@nxp.com>
> Subject: Re: [PATCH v4 3/4] usb: typec: mux: add "compatible" property for
> switch match
> 
> On 20-10-20 13:02:30, Jun Li wrote:
> >
> >
> > > -----Original Message-----
> > > From: Peter Chen <peter.chen@nxp.com>
> > > Sent: Tuesday, October 20, 2020 2:05 PM
> > > To: Jun Li <jun.li@nxp.com>
> > > Cc: heikki.krogerus@linux.intel.com; robh+dt@kernel.org;
> > > rafael@kernel.org; gregkh@linuxfoundation.org;
> > > andriy.shevchenko@linux.intel.com; hdegoede@redhat.com;
> > > lee.jones@linaro.org; mika.westerberg@linux.intel.com;
> > > dmitry.torokhov@gmail.com; prabhakar.mahadev-lad.rj@bp.renesas.com;
> > > laurent.pinchart+renesas@ideasonboard.com;
> > > linux-usb@vger.kernel.org; devicetree@vger.kernel.org; dl-linux-imx
> > > <linux-imx@nxp.com>
> > > Subject: Re: [PATCH v4 3/4] usb: typec: mux: add "compatible"
> > > property for switch match
> > >
> > > On 20-10-19 17:03:14, Li Jun wrote:
> > > > For those need a dedicated typec switch simple solution driver,
> > > > use compatible property for matching.
> > > >
> > > > Signed-off-by: Li Jun <jun.li@nxp.com>
> > > > ---
> > > > New patch for v4.
> > > >
> > > >  drivers/usb/typec/mux.c | 7 ++++---
> > > >  1 file changed, 4 insertions(+), 3 deletions(-)
> > > >
> > > > diff --git a/drivers/usb/typec/mux.c b/drivers/usb/typec/mux.c
> > > > index
> > > > 52ad277..3da17d1 100644
> > > > --- a/drivers/usb/typec/mux.c
> > > > +++ b/drivers/usb/typec/mux.c
> > > > @@ -39,7 +39,8 @@ static void *typec_switch_match(struct
> > > > device_connection *con, int ep,  {
> > > >  	struct device *dev;
> > > >
> > > > -	if (con->id && !fwnode_property_present(con->fwnode, con->id))
> > > > +	if (con->id && !fwnode_is_compatible(con->fwnode, con->id) &&
> > > > +		       !fwnode_property_present(con->fwnode, con->id))
> > > >  		return NULL;
> > >
> > > If property is not present, should not fwnode_is_compatible return NULL?
> >
> > Do you want to say:
> >
> > If property is not present, should not *typec_switch_match* return NULL?
> 
> If fwnode_is_compatible returns true, it should mean the
> fwnode_property_present is true too. 

Nope.

fwnode_is_compatible():
        property name: compatible
fwnode_property_present():
        property name: typec-orientation-switch

> But if fwnode_is_compatible is false,
> the fwnode_property_present may return true, the code does not return NULL.

Yes. Original matching via bool property is still allowed.

> Then, with this new patch, what changes compared to original logic?

One more way to match typec switch via compatible.

> 
> Peter
> 
> > >
> > > >
> > > >  	dev = class_find_device(&typec_mux_class, NULL, con->fwnode, @@
> > > > -61,8 +62,8 @@ struct typec_switch *fwnode_typec_switch_get(struct
> > > > fwnode_handle *fwnode)  {
> > > >  	struct typec_switch *sw;
> > > >
> > > > -	sw = fwnode_connection_find_match(fwnode, "orientation-switch",
> NULL,
> > > > -					  typec_switch_match);
> > > > +	sw = fwnode_connection_find_match(fwnode,
> "typec-orientation-switch",
> > > > +					  NULL, typec_switch_match);
> > > >  	if (!IS_ERR_OR_NULL(sw))
> > > >  		WARN_ON(!try_module_get(sw->dev.parent->driver->owner));
> > > >
> > > > --
> > > > 2.7.4
> > > >
> > >
> > > --
> > >
> > > Thanks,
> > > Peter Chen
> 
> --
> 
> Thanks,
> Peter Chen