linux-kernel - [PATCH V2 dt-schema.git] schemas: add NVMEM cell with #nvmem-cell-cells

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <20221121114708.10161-1-zajec5@gmail.com>
Date:   Mon, 21 Nov 2022 12:47:08 +0100
From:   Rafał Miłecki <zajec5@...il.com>
To:     Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>
Cc:     Michael Walle <michael@...le.cc>,
        Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
        Miquel Raynal <miquel.raynal@...tlin.com>,
        Richard Weinberger <richard@....at>,
        Vignesh Raghavendra <vigneshr@...com>,
        linux-mtd@...ts.infradead.org, devicetree@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Rafał Miłecki <rafal@...ecki.pl>
Subject: [PATCH V2 dt-schema.git] schemas: add NVMEM cell with #nvmem-cell-cells

From: Rafał Miłecki <rafal@...ecki.pl>

Some NVMEM cells may provide more than 1 value. An example can be base
MAC address that is used for calculating multiple MACs (for few
different devices). For specifying value to read phandle needs to be
used with an argument.

Cc: Srinivas Kandagatla" <srinivas.kandagatla@...aro.org>
Cc: Michael Walle <michael@...le.cc>
Signed-off-by: Rafał Miłecki <rafal@...ecki.pl>
---
V2: Drop redundant quotes (thanks Krzysztof)

Please note there is ongoing work by Michael who chose to modify
meta-schema in his work: https://github.com/devicetree-org/dt-schema/pull/89

This bit is required for moving forward with the
[PATCH v2 00/20] nvmem: core: introduce NVMEM layouts
https://lore.kernel.org/linux-arm-kernel/20220901221857.2600340-1-michael@walle.cc/

As pointed out by Rob #nvmem-cell-cells should be added to the dt-schema
and not a Linux binding:
Re: [PATCH v2 15/20] dt-bindings: nvmem: add YAML schema for the sl28 vpd layout
https://lore.kernel.org/linux-arm-kernel/20220912192038.GA1661550-robh@kernel.org/

sl28 is one example that needs #nvmem-cell-cells
u-boot,env is another one
---
 dtschema/schemas/nvmem/nvmem-cell.yaml | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 dtschema/schemas/nvmem/nvmem-cell.yaml

diff --git a/dtschema/schemas/nvmem/nvmem-cell.yaml b/dtschema/schemas/nvmem/nvmem-cell.yaml
new file mode 100644
index 0000000..1a1741d
--- /dev/null
+++ b/dtschema/schemas/nvmem/nvmem-cell.yaml
@@ -0,0 +1,23 @@
+# SPDX-License-Identifier: BSD-2-Clause
+$id: http://devicetree.org/schemas/nvmem/nvmem-cell.yaml#
+$schema: http://devicetree.org/meta-schemas/base.yaml#
+
+title: NVMEM Cell Common Properties
+description: Schema for NVMEM cell devicetree bindings
+maintainers:
+  - Rafał Miłecki <rafal@...ecki.pl>
+  - Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
+
+# always select the core schema
+select: true
+
+properties:
+  "#nvmem-cell-cells":
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: >
+      Some NVMEM cells may consist of raw data that requires some extra
+      processing. They may provide more than 1 value.
+
+      Passing extra argument(s) allows selecting data to access.
+
+additionalProperties: true
-- 
2.34.1