> -----Original Message-----
> From: dmitry.torokhov@xxxxxxxxx <dmitry.torokhov@xxxxxxxxx>
> Sent: Thursday, October 22, 2020 2:56 AM
> To: Jun Li <jun.li@xxxxxxx>
> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>;
> heikki.krogerus@xxxxxxxxxxxxxxx; robh+dt@xxxxxxxxxx; rafael@xxxxxxxxxx;
> gregkh@xxxxxxxxxxxxxxxxxxx; hdegoede@xxxxxxxxxx; lee.jones@xxxxxxxxxx;
> mika.westerberg@xxxxxxxxxxxxxxx;
> prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx;
> laurent.pinchart+renesas@xxxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>; Peter Chen
> <peter.chen@xxxxxxx>
> Subject: Re: [PATCH v4 2/4] device property: Add fwnode_is_compatible() and
> device_is_compatible() helpers
>
> On Tue, Oct 20, 2020 at 11:13:47AM +0000, Jun Li wrote:
> >
> >
> > > -----Original Message-----
> > > From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> > > Sent: Monday, October 19, 2020 8:25 PM
> > > To: Jun Li <jun.li@xxxxxxx>
> > > Cc: heikki.krogerus@xxxxxxxxxxxxxxx; robh+dt@xxxxxxxxxx;
> > > rafael@xxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; hdegoede@xxxxxxxxxx;
> > > lee.jones@xxxxxxxxxx; mika.westerberg@xxxxxxxxxxxxxxx;
> > > dmitry.torokhov@xxxxxxxxx; prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx;
> > > laurent.pinchart+renesas@xxxxxxxxxxxxxxxx;
> > > linux-usb@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; dl-linux-imx
> > > <linux-imx@xxxxxxx>; Peter Chen <peter.chen@xxxxxxx>
> > > Subject: Re: [PATCH v4 2/4] device property: Add
> > > fwnode_is_compatible() and
> > > device_is_compatible() helpers
> > >
> > > On Mon, Oct 19, 2020 at 05:03:13PM +0800, Li Jun wrote:
> > > > From: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> > > >
> > > > Since there are also some ACPI platforms where the "compatible"
> > > > property is used, introducing a generic helper function
> > > > fwnode_is_compatible() that can be used with DT, ACPI and swnodes,
> > > > and a wrapper function
> > > > device_is_compatible() with it.
> > > >
> > > > The function calls of_device_is_comaptible() with OF nodes, and
> > > > with ACPI and swnodes it matches the given string against the "compatible"
> > > > string property array.
> > >
> > > ...
> > >
> > > > + * Match the compatible strings of @fwnode against @compat.
> > > > + Returns positive
> > > > + * value on match, and 0 when no matching compatible string is found.
> > >
> > > Please move Returns... to a separate paragraph.
> >
> > OK, will change.
> >
> > >
> > > Btw, this is not true...
> > >
> > > > +int fwnode_is_compatible(struct fwnode_handle *fwnode, const char
> > > > +*compat) {
> > > > + int ret;
> > > > +
> > > > + if (is_of_node(fwnode))
> > > > + return of_device_is_compatible(to_of_node(fwnode),
> compat);
> > > > +
> > > > + ret = fwnode_property_match_string(fwnode, "compatible",
> > > > +compat);
> > > > +
> > >
> > > > + return ret < 0 ? 0 : 1;
> > >
> > > ...and this is at least strange after all.
> >
> > of_device_is_compatible() will return positive value on match, and 0
> > when no matching,
> > fwnode_property_match_string() will return 0 if the property was found
> > (success); and negative error code on failure. so the return
> > conversion of fwnode_property_match_string () should work here.
>
> Yes, but please make the function return bool instead of int.
> of_device_is_compatible() returns "score", so it is int, but here we only
> want yes/no.
>
> So
>
> return fwnode_property_match_string(...) == 0;
My understanding this is to keep this new API fwnode_is_compatible() consistent
with of_device_is_compatible(). I would wait patch author Heikki to comment this.
thanks
Li Jun
>
> Thanks.
>
> --
> Dmitry
