On Thu, Jan 15, 2015 at 01:52:01PM +0000, Mark Rutland wrote: > On Wed, Jan 14, 2015 at 08:58:18PM +0000, Suman Anna wrote: > > This patch adds the generic common bindings used to represent > > a hwlock device and use/request locks in a device-tree build. > > > > All the platform-specific hwlock driver implementations need the > > number of locks and associated base id for registering the locks > > present within the device with the driver core. This base id > > needs to be unique across multiple IP instances of a hwspinlock > > device, so that each hwlock can be represented uniquely in a > > system. > > > > The number of locks is represented by 'hwlock-num-locks' property, > > and the base id is represented by the 'hwlock-base-id' property. > > The args specifier length is dependent on each vendor-specific > > implementation and is represented through the '#hwlock-cells' > > property. Client users need to use the property 'hwlocks' for > > requesting specific lock(s). > > > > Note that the document is named hwlock.txt deliberately to keep > > it a bit more generic. > > > > Cc: Rob Herring <robh+dt@xxxxxxxxxx> > > Signed-off-by: Suman Anna <s-anna@xxxxxx> > > --- > > v7: Revised binding info for hwlock-base-id, it is mandatory now > > > > .../devicetree/bindings/hwlock/hwlock.txt | 55 ++++++++++++++++++++++ > > 1 file changed, 55 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/hwlock/hwlock.txt > > > > diff --git a/Documentation/devicetree/bindings/hwlock/hwlock.txt b/Documentation/devicetree/bindings/hwlock/hwlock.txt > > new file mode 100644 > > index 000000000000..8de7aaf878f9 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/hwlock/hwlock.txt > > @@ -0,0 +1,55 @@ > > +Generic hwlock bindings > > +======================= > > + > > +Generic bindings that are common to all the hwlock platform specific driver > > +implementations. > > + > > +The validity and need of these common properties may vary from one platform > > +implementation to another. The platform specific bindings should explicitly > > +state if an optional property is used. Please also look through the individual > > +platform specific hwlock binding documentations for identifying the applicable > > +properties. > > + > > +Common properties: > > +- #hwlock-cells: Specifies the number of cells needed to represent a > > + specific lock. This property is mandatory for all > > + platform implementations. > > +- hwlock-num-locks: Number of locks present in a hwlock device. This > > + property is needed on hwlock devices, where the number > > + of supported locks within a hwlock device cannot be > > + read from a register. > > +- hwlock-base-id: An unique base Id for the locks for a particular hwlock > > + device. This property is mandatory for all platform > > + implementations. > > This property makes no sense. The ID encoded in the hwlock cells is > relative to the instance (identified by phandle), not global. So the DT > has no global ID space. > > Why do you think you need this? Having looked at the way this proeprty is used, NAK. If you need to carve up a Linux-internal ID space, do that dynamically. There is no need for this property. Mark. -- 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
