On Mon, May 22, 2023 at 03:51:01PM -0500, Bjorn Andersson wrote:
> On Fri, Oct 08, 2021 at 03:38:21PM +0300, Heikki Krogerus wrote:
> > Hi,
> >
> > On Thu, Oct 07, 2021 at 09:15:12AM -0700, Bjorn Andersson wrote:
> > > The one thing that I still don't understand though is, if the typec_mux
> > > is used by the typec controller to inform _the_ mux about the function
> > > to be used, what's up with the complexity in typec_mux_match()? This is
> > > what lead me to believe that typec_mux was enabling/disabling individual
> > > altmodes, rather just flipping the physical switch at the bottom.
> >
> > Ah, typec_mux_match() is a mess. I'm sorry about that. I think most of
> > the code in that function is not used by anybody. If I remember
> > correctly, all that complexity is attempting to solve some
> > hypothetical corner case(s). Probable a case where we have multiple
> > muxes per port to deal with.
> >
> > I think it would probable be best to clean the function to the bare
> > minimum by keeping only the parts that are actually used today
> > (attached).
> >
>
> Sorry for not replying to this in a timely manner Heikki. I've been
> ignoring this issue for a long time now, just adding "svid" to our dts
> files. But, this obviously shows up in DT validation - and I'd prefer
> not defining these properties as valid.
>
> The attached patch works as expected.
>
Sorry, I must have failed at applying the patch - it doesn't work...
> Could you please spin this as a proper patch, so we can get it merged?
>
> Regards,
> Bjorn
>
> > thanks,
> >
> > --
> > heikki
>
> > diff --git a/drivers/usb/typec/mux.c b/drivers/usb/typec/mux.c
> > index c8340de0ed495..44f168c9bd9bf 100644
> > --- a/drivers/usb/typec/mux.c
> > +++ b/drivers/usb/typec/mux.c
> > @@ -193,56 +193,15 @@ static int mux_fwnode_match(struct device *dev, const
> > void *fwnode)
> > static void *typec_mux_match(struct fwnode_handle *fwnode, const char *id,
> > void *data)
> > {
> > - const struct typec_altmode_desc *desc = data;
> > struct device *dev;
> > - bool match;
> > - int nval;
> > - u16 *val;
> > - int ret;
> > - int i;
> >
> > /*
> > - * Check has the identifier already been "consumed". If it
> > - * has, no need to do any extra connection identification.
> > + * The connection identifier will be needed with device graph (OF
> > graph).
> > + * Device graph is not supported by this code yet, so bailing out.
> > */
> > - match = !id;
> > - if (match)
> > - goto find_mux;
> > -
> > - /* Accessory Mode muxes */
> > - if (!desc) {
> > - match = fwnode_property_present(fwnode, "accessory");
> > - if (match)
> > - goto find_mux;
> > - return NULL;
> > - }
> > -
> > - /* Alternate Mode muxes */
> > - nval = fwnode_property_count_u16(fwnode, "svid");
> > - if (nval <= 0)
> > - return NULL;
> > -
> > - val = kcalloc(nval, sizeof(*val), GFP_KERNEL);
> > - if (!val)
> > - return ERR_PTR(-ENOMEM);
> > -
> > - ret = fwnode_property_read_u16_array(fwnode, "svid", val, nval);
> > - if (ret < 0) {
> > - kfree(val);
> > - return ERR_PTR(ret);
> > - }
> > -
> > - for (i = 0; i < nval; i++) {
> > - match = val[i] == desc->svid;
> > - if (match) {
> > - kfree(val);
> > - goto find_mux;
> > - }
> > - }
> > - kfree(val);
> > - return NULL;
> > + if (id)
We pass id as "mode-switch", so this will never be NULL. But we also only
want to consider endpoints with "mode-switch", otherwise we'll fail if
any of the referred endpoints is not implementing a typec_mux...
So this needs the same snippet we find in typec_switch_match():
/*
* Device graph (OF graph) does not give any means to identify the
* device type or the device class of the remote port parent that
@fwnode
* represents, so in order to identify the type or the class of @fwnode
* an additional device property is needed. With typec switches the
* property is named "orientation-switch" (@id). The value of the device
* property is ignored.
*/
if (id && !fwnode_property_present(fwnode, id))
return NULL;
With that, this works as expected!
Regards,
Bjorn
> > + return ERR_PTR(-ENOTSUPP);
> >
> > -find_mux:
> > dev = class_find_device(&typec_mux_class, NULL, fwnode,
> > mux_fwnode_match);
> >
>
