[PATCH v4 1/2] dt-bindings: ramoops: Inherit reserve memory property

[Mukesh Ojha <quic_mojha@quicinc.com>]

The reserved memory region for ramoops is assumed to be at a
fixed and known location when read from the devicetree. This
is not desirable in an environment where it is preferred the
region to be dynamically allocated at runtime, as opposed to
being fixed at compile time.

So, update the ramoops binding by inheriting some reserve memory
property to allocate the ramoops region dynamically.

Cc: Kees Cook <keescook@chromium.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guilherme G. Piccoli <gpiccoli@igalia.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com>
---
Changes in v4:
 - Addressed comment made by Krzysztof on ramoops node name.

Changes in v3:
 - Fixed yaml error and updated commit text as per comment.

Change in v2:
  - Added this patch as per changes going to be done in patch 3/3

 .../bindings/reserved-memory/ramoops.yaml          | 34 ++++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/reserved-memory/ramoops.yaml b/Documentation/devicetree/bindings/reserved-memory/ramoops.yaml
index 0391871..8741626 100644
--- a/Documentation/devicetree/bindings/reserved-memory/ramoops.yaml
+++ b/Documentation/devicetree/bindings/reserved-memory/ramoops.yaml
@@ -10,7 +10,8 @@ description: |
   ramoops provides persistent RAM storage for oops and panics, so they can be
   recovered after a reboot. This is a child-node of "/reserved-memory", and
   is named "ramoops" after the backend, rather than "pstore" which is the
-  subsystem.
+  subsystem. This region can be reserved both statically or dynamically by
+  using appropriate property in device tree.
 
   Parts of this storage may be set aside for other persistent log buffers, such
   as kernel log messages, or for optional ECC error-correction data.  The total
@@ -112,7 +113,13 @@ unevaluatedProperties: false
 
 required:
   - compatible
-  - reg
+
+oneOf:
+  - required:
+      - reg
+
+  - required:
+      - size
 
 anyOf:
   - required: [record-size]
@@ -142,3 +149,26 @@ examples:
             };
         };
     };
+
+  - |
+    / {
+        compatible = "foo";
+        model = "foo";
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        reserved-memory {
+            #address-cells = <1>;
+            #size-cells = <1>;
+            ranges;
+
+            ramoops_region: ramoops {
+                compatible = "ramoops";
+                alloc-ranges = <0x00000000 0xffffffff>;
+                size = <0x0 0x10000>;       /* 64kB */
+                console-size = <0x8000>;    /* 32kB */
+                record-size = <0x400>;      /*  1kB */
+                ecc-size = <16>;
+            };
+        };
+    };
-- 
2.7.4