Hi, On 05.11.2013 19:41, ext Pantelis Antoniou wrote: > Add a runtime interface to /proc to enable generic device tree overlay > usage. > > Two new /proc files are added: > > /proc/device-tree-overlay & /proc/device-tree-overlay-status > > /proc/device-tree-overlay accepts a stream of a device tree objects and > applies it to the running kernel's device tree. > > $ cat ~/BB-UART2-00A0.dtbo >device-tree-overlay > overlay_proc_release: Applied #2 overlay segments @0 > > /proc/device-tree-overlay-status displays the the overlays added using > the /proc interface > > $ cat device-tree-overlay-status > 0: 861 bytes BB-UART2:00A0 > > The format of the status line is > <ID>: <SIZE> bytes <part-number>:<version> > > <ID> is the id of the overlay > <SIZE> is the size of the overlay in bytes > <part-number>, <version> are (optional) root level properties of the DTBO > > You can remove an overlay by echoing the <ID> number of the overlay > precedded with a '-' > > So > $ echo "-0" >device-tree-overlay-status > Wouldn't it be easier if echo "-BB-UART2-00A0" > device-tree-overlay-status was supported also? That way one doesn't need to know the order in which the overlays were applied or parse the status file to get the <ID>. > Removes the overlay. > > Note that this seldom works on most platforms since platform_device > removal is something that almost never works without extra patches. > > Signed-off-by: Pantelis Antoniou <panto@xxxxxxxxxxxxxxxxxxxxxxx> It would be very helpful to me if I would have a notification mechanism for overlay add and remove operations based on blocking_notifier_call_chain(),. This way other drivers can be notified when the dt changes. But I guess that could be added in the future with another patch. Thanks, Ionut -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
