[RFC PATCH v1 2/2] dt-bindings: arm: Add description to the new property for-s2idle-only

[zhang . lyra]

From: Chunyan Zhang <chunyan.zhang@xxxxxxxxxx>

Add a new property for-s2idle-only. The idle-state marked with this
property will be set with CPUIDLE_FLAG_S2IDLE during initialization
and it would be expected to be found as deepest state for s2idle
rather than other cases like play_idle().

Signed-off-by: Chunyan Zhang <chunyan.zhang@xxxxxxxxxx>
---
 Documentation/devicetree/bindings/arm/idle-states.yaml | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/arm/idle-states.yaml b/Documentation/devicetree/bindings/arm/idle-states.yaml
index ea805c1e6b20..cec47b3a447f 100644
--- a/Documentation/devicetree/bindings/arm/idle-states.yaml
+++ b/Documentation/devicetree/bindings/arm/idle-states.yaml
@@ -263,7 +263,6 @@ patternProperties:
     description: |
       Each state node represents an idle state description and must be defined
       as follows.
-
       The idle state entered by executing the wfi instruction (idle_standby
       SBSA,[3][4]) is considered standard on all ARM platforms and therefore
       must not be listed.
@@ -283,6 +282,15 @@ patternProperties:
              lost on state entry, otherwise it is retained.
         type: boolean
 
+      for-s2idle-only:
+        description:
+          This indicates that the state only can be found as deepest state
+          for s2idle rather than other cases like play_idle(). In general,
+          the state having this property should have longer min-residency
+          than the cpuidle target min-residency which CPU QoS constraints
+          defines, to avoid being used by runtime cpuidle.
+        type: boolean
+
       entry-latency-us:
         description:
           Worst case latency in microseconds required to enter the idle state.
-- 
2.20.1