Hi,
On Thu, Jun 09, 2022 at 06:09:41PM +0000, Prashant Malani wrote:
> There are some drivers that can use the Type C mux API, but don't have
> to. Introduce CONFIG guards for the mux functions so that drivers can
> include the header file and not run into compilation errors on systems
> which don't have CONFIG_TYPEC enabled. When CONFIG_TYPEC is not enabled,
> the Type C mux functions will be stub versions of the original calls.
>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Signed-off-by: Prashant Malani <pmalani@xxxxxxxxxxxx>
> ---
>
> Changes since v1:
> - Added static inline to stub functions.
> - Updated function signature of stub functions from "struct typec_mux"
> to "struct typec_mux_dev" in accordance with updates from commit
> 713fd49b430c ("usb: typec: mux: Introduce indirection")
>
> include/linux/usb/typec_mux.h | 38 +++++++++++++++++++++++++++++++++++
> 1 file changed, 38 insertions(+)
>
> diff --git a/include/linux/usb/typec_mux.h b/include/linux/usb/typec_mux.h
> index ee57781dcf28..9eda6146fd26 100644
> --- a/include/linux/usb/typec_mux.h
> +++ b/include/linux/usb/typec_mux.h
> @@ -58,6 +58,8 @@ struct typec_mux_desc {
> void *drvdata;
> };
>
> +#if IS_ENABLED(CONFIG_TYPEC) || IS_MODULE(CONFIG_TYPEC)
> +
> struct typec_mux *fwnode_typec_mux_get(struct fwnode_handle *fwnode,
> const struct typec_altmode_desc *desc);
> void typec_mux_put(struct typec_mux *mux);
> @@ -76,4 +78,40 @@ void typec_mux_unregister(struct typec_mux_dev *mux);
> void typec_mux_set_drvdata(struct typec_mux_dev *mux, void *data);
> void *typec_mux_get_drvdata(struct typec_mux_dev *mux);
>
> +#else
> +
> +static inline struct typec_mux *fwnode_typec_mux_get(struct fwnode_handle *fwnode,
> + const struct typec_altmode_desc *desc)
> +{
> + return ERR_PTR(-EOPNOTSUPP);
> +}
The mux is optional resource for the drivers - fwnode_typec_mux_get()
returns NULL if there is no mux for the caller - so it's better to
just return NULL from this stub.
> +static inline void typec_mux_put(struct typec_mux *mux) {}
> +
> +static inline int typec_mux_set(struct typec_mux *mux, struct typec_mux_state *state)
> +{
> + return -EOPNOTSUPP;
> +}
Return 0 in this case. That way this stub matches the function
behaviour:
...
if (IS_ERR_OR_NULL(mux))
return 0;
...
> +static inline struct typec_mux *
> +typec_mux_get(struct device *dev, const struct typec_altmode_desc *desc)
> +{
> + return ERR_PTR(-EOPNOTSUPP);
> +}
You don't need this one. Just leave the original outside of the ifdef.
It's already an inline wrapper function.
> +static inline struct typec_mux_dev *
> +typec_mux_register(struct device *parent, const struct typec_mux_desc *desc)
> +{
> + return ERR_PTR(-EOPNOTSUPP);
> +}
> +static inline void typec_mux_unregister(struct typec_mux_dev *mux) {}
> +
> +static inline void typec_mux_set_drvdata(struct typec_mux_dev *mux, void *data) {}
> +static inline void *typec_mux_get_drvdata(struct typec_mux_dev *mux)
> +{
> + return ERR_PTR(-EOPNOTSUPP);
> +}
> +
> +#endif /* CONFIG_TYPEC */
> +
> #endif /* __USB_TYPEC_MUX */
thanks,
--
heikki
