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From:   =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
To:     Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org,
        =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>,
        Christian Marangi <ansuelsmth@gmail.com>
Subject: [PATCH 2/2] dt-bindings: nvmem: u-boot,env: describe "data-size" property
Date:   Wed, 13 Dec 2023 16:47:21 +0100
Message-Id: <20231213154721.5037-2-zajec5@gmail.com>
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From: Rafał Miłecki <rafal@milecki.pl>

Describe what "data-size" means in U-Boot env context and why it may be
needed. It's a generic property but giving it some extra meaning in
U-Boot context may be helpful.

Cc: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
 .../devicetree/bindings/nvmem/u-boot,env.yaml          | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml b/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
index 9c36afc7084b..0006f022d0af 100644
--- a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
+++ b/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
@@ -44,6 +44,15 @@ properties:
   reg:
     maxItems: 1
 
+  data-size:
+    description:
+      U-Boot environment data size is set and hardcoded during compilation using
+      CONFIG_ENV_SIZE. Knowing it is critical for CRC32 checksum calculation.
+
+      This property allows specifying it in case it differs from NVMEM device
+      size. It may happen if device partitioning was designed with different
+      concepts in mind (like block alignment or future-proof size).
+
   bootcmd:
     type: object
     description: Command to use for automatic booting
@@ -76,6 +85,7 @@ examples:
         env: partition@40000 {
             compatible = "u-boot,env";
             reg = <0x40000 0x10000>;
+            data-size = <0x4000>;
 
             mac: ethaddr {
                 #nvmem-cell-cells = <1>;
-- 
2.35.3