On Fri, Nov 20, 2020 at 06:02:23PM -0800, Saravana Kannan wrote: > Add support for creating supplier-consumer links between fwnodes. It is > intended for internal use the driver core and generic firmware support > code (eg. Device Tree, ACPI), so it is simple by design and the API > provided is limited. > > Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx> > --- > drivers/base/core.c | 98 ++++++++++++++++++++++++++++++++++++++++++ > drivers/of/dynamic.c | 1 + > include/linux/fwnode.h | 14 ++++++ > 3 files changed, 113 insertions(+) > > diff --git a/drivers/base/core.c b/drivers/base/core.c > index 401fa7e3505c..e2b246a44d1a 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -50,6 +50,104 @@ static LIST_HEAD(wait_for_suppliers); > static DEFINE_MUTEX(wfs_lock); > static LIST_HEAD(deferred_sync); > static unsigned int defer_sync_state_count = 1; > +static DEFINE_MUTEX(fwnode_link_lock); > + > +/** > + * fwnode_link_add - Create a link between two fwnode_handles. > + * @con: Consumer end of the link. > + * @sup: Supplier end of the link. > + * > + * Create a fwnode link between fwnode handles @con and @sup. The fwnode link > + * represents the detail that the firmware lists @sup fwnode as supplying a > + * resource to @con. > + * > + * The driver core will use the fwnode link to create a device link between the > + * two device objects corresponding to @con and @sup when they are created. The > + * driver core will automatically delete the fwnode link between @con and @sup > + * after doing that. > + * > + * Attempts to create duplicate links between the same pair of fwnode handles > + * are ignored and there is no reference counting. Sorry to ask, but why is that? Isn't this a programmer error? Thanks
