+gboolean config_key_has_cap(struct sr_dev_driver *driver,
+ const struct sr_dev_inst *sdi, struct sr_channel_group *cg,
+ uint32_t key, uint32_t capability);
+int maybe_config_get(struct sr_dev_driver *driver,
+ const struct sr_dev_inst *sdi, struct sr_channel_group *cg,
+ uint32_t key, GVariant **gvar);
+int maybe_config_set(struct sr_dev_driver *driver,
+ const struct sr_dev_inst *sdi, struct sr_channel_group *cg,
+ uint32_t key, GVariant *gvar);
+int maybe_config_list(struct sr_dev_driver *driver,
+ const struct sr_dev_inst *sdi, struct sr_channel_group *cg,
+ uint32_t key, GVariant **gvar);