Re: [PATCH v4 3/5] dt-bindings: Add TI SCI PM Domains

[Dave Gerlach]

On 03/15/2017 12:53 PM, Rob Herring wrote:
> On Tue, Mar 07, 2017 at 04:22:32AM -0600, Dave Gerlach wrote:
> > Add a generic power domain implementation, TI SCI PM Domains, that
> > will hook into the genpd framework and allow the TI SCI protocol to
> > control device power states.
> >
> > Also, provide macros representing each device index as understood
> > by TI SCI to be used in the device node power-domain references.
> > These are identifiers for the K2G devices managed by the PMMC.
> >
> > Signed-off-by: Nishanth Menon <nm@xxxxxx>
> > Signed-off-by: Dave Gerlach <d-gerlach@xxxxxx>
> > ---
> >  .../devicetree/bindings/soc/ti/sci-pm-domain.txt   | 59 ++++++++++++++
> >  MAINTAINERS                                        |  2 +
> >  include/dt-bindings/genpd/k2g.h                    | 90 ++++++++++++++++++++++
> >  3 files changed, 151 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt
> >  create mode 100644 include/dt-bindings/genpd/k2g.h
> >
> > diff --git a/Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt b/Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt
> > new file mode 100644
> > index 000000000000..86a6a3d52ed6
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt
> > @@ -0,0 +1,59 @@
> > +Texas Instruments TI-SCI Generic Power Domain
> > +---------------------------------------------
> > +
> > +Some TI SoCs contain a system controller (like the PMMC, etc...) that is
> > +responsible for controlling the state of the IPs that are present.
> > +Communication between the host processor running an OS and the system
> > +controller happens through a protocol known as TI-SCI [1]. This pm domain
> > +implementation plugs into the generic pm domain framework and makes use of
> > +the TI SCI protocol power on and off each device when needed.
>
> The last sentence is mostly Linux implementation details. The binding is
> power domains. The Linux framework is PM domains. Let's keep those
> distinct and the latter doesn't belong in bindings.

Ok, I will send an update to just this patch and drop the last sentence above.

Regards,
Dave

> > +
> > +[1] Documentation/devicetree/bindings/arm/keystone/ti,sci.txt
> > +
> > +PM Domain Node
> > +==============
> > +The PM domain node represents the global PM domain managed by the PMMC, which
> > +in this case is the implementation as documented by the generic PM domain
> > +bindings in Documentation/devicetree/bindings/power/power_domain.txt.  Because
> > +this relies on the TI SCI protocol to communicate with the PMMC it must be a
> > +child of the pmmc node.
> > +
> > +Required Properties:
> > +--------------------
> > +- compatible: should be "ti,sci-pm-domain"
> > +- #power-domain-cells: Must be 1 so that an id can be provided in each
> > +		       device node.
> > +
> > +Example (K2G):
> > +-------------
> > +	pmmc: pmmc {
> > +		compatible = "ti,k2g-sci";
> > +		...
> > +
> > +		k2g_pds: power-controller {
> > +			compatible = "ti,sci-pm-domain";
> > +			#power-domain-cells = <1>;
> > +		};
> > +	};
> > +
> > +PM Domain Consumers
> > +===================
> > +Hardware blocks belonging to a PM domain should contain a "power-domains"
> > +property that is a phandle pointing to the corresponding PM domain node
> > +along with an index representing the device id to be passed to the PMMC
> > +for device control.
> > +
> > +Required Properties:
> > +--------------------
> > +- power-domains: phandle pointing to the corresponding PM domain node
> > +		 and an ID representing the device.
> > +
> > +See dt-bindings/genpd/k2g.h for the list of valid identifiers for k2g.
> > +
> > +Example (K2G):
> > +--------------------
> > +	uart0: serial@02530c00 {
> > +		compatible = "ns16550a";
> > +		...
> > +		power-domains = <&k2g_pds K2G_DEV_UART0>;
> > +	};