On Tue, Dec 15 2015 at 03:07 -0700, Marc Titinger wrote:
On 10/12/2015 17:53, Ulf Hansson wrote:
On 17 November 2015 at 23:37, Lina Iyer <lina.iyer@xxxxxxxxxx> wrote:
diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt
index 025b5e7..e2f542e 100644
--- a/Documentation/devicetree/bindings/power/power_domain.txt
+++ b/Documentation/devicetree/bindings/power/power_domain.txt
@@ -29,6 +29,44 @@ Optional properties:
specified by this binding. More details about power domain specifier are
available in the next section.
+- power-states : A phandle of an idle-state that shall be soaked into a
+ generic domain power state. The power-state shall be
+ compatible with "linux,domain-state".
Why mention the Linux specific "generic power domain" here?
Let's instead try to describe this without using specific terminology
from Linux.
Hmm, I will need Lina's help to answer this one.
Following a previous review actually I dropped this power-states
compatible, to stick with idle-states.
I didnt want this to be ARM specific. An arm,idle-state is too specific
to be reused for generic PM domains, hence this compatible. We dont need
a compatible property, but I thought it would be nice to have the
property to give structure to the power state node.
+
+==Power state==
+
+A PM domain power state describes an idle state of a domain and must be
+have the following properties -
+
+ - compatible
+ Usage: Required
+ Value type: <stringlist>
+ Definition: Must be "linux,domain-state"
Why do you need a compatible string?
You already have the phandle available, I suppose you can use that
instead of parsing for a new compatible string.
Hmm.. okay.
+
+ - entry-latency-us
+ Usage: Not required if wakeup-latency-us is provided.
+ Value type: <prop-encoded-array>
+ Definition: u32 value representing worst case latency in
+ microseconds required to enter the idle state.
+ The exit-latency-us duration may be guaranteed
+ only after entry-latency-us has passed.
+
+ - exit-latency-us
+ Usage: Not required if wakeup-latency-us is provided.
+ Value type: <prop-encoded-array>
+ Definition: u32 value representing worst case latency
+ in microseconds required to exit the idle state.
+
+ - wakeup-latency-us:
+ Usage: Not required if entry-latency-us and exit-latency-us
+ are provided.
+ Value type: <prop-encoded-array>
+ Definition: u32 value representing maximum delay between the
+ signaling the wakeup of the domain and the domain resuming
+ regular operation.
+ If omitted, this is assumed to be equal to:
+ entry-latency-us + exit-latency-us
I think we should decide which of the two alternatives to use, we
shouldn't make it more complicated than needed.
Agreed.
I like the entry + exit option.
Thanks,
Lina
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