Re: [PATCH stblinux.git 1/2] dt-bindings: firmware: add Broadcom's NVRAM memory mapping
From: Rob Herring <robh@kernel.org>
Date: 2021-03-08 18:44:00
Also in:
linux-arm-kernel, linux-devicetree, lkml
On Tue, Mar 02, 2021 at 08:44:04AM +0100, Rafał Miłecki wrote:
quoted hunk ↗ jump to hunk
From: Rafał Miłecki <rafal@milecki.pl> NVRAM structure contains device data and can be accessed using MMIO. Signed-off-by: Rafał Miłecki <rafal@milecki.pl> --- .../bindings/firmware/brcm,nvram.yaml | 41 +++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 Documentation/devicetree/bindings/firmware/brcm,nvram.yamldiff --git a/Documentation/devicetree/bindings/firmware/brcm,nvram.yaml b/Documentation/devicetree/bindings/firmware/brcm,nvram.yaml new file mode 100644 index 000000000000..12af8e2e7c9c --- /dev/null +++ b/Documentation/devicetree/bindings/firmware/brcm,nvram.yaml@@ -0,0 +1,41 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- +$id: "http://devicetree.org/schemas/firmware/brcm,nvram.yaml#" +$schema: "http://devicetree.org/meta-schemas/core.yaml#" + +title: Broadcom's NVRAM + +maintainers: + - Rafał Miłecki <rafal@milecki.pl> + +description: | + NVRAM is a structure containing device specific environment variables. + It is used for storing device configuration, booting parameters and + calibration data.
The structure of the data is fully discoverable just from a genericish 'brcm,nvram'? And it's a dedicated memory outside of regular RAM?
+
+ It's required very early in booting process and so is made available
+ using memory mapping.
+
+ NVRAM can be found on Broadcom BCM47xx MIPS, Northstar ARM Cortex-A9
+ and some more devices.
+
+properties:
+ compatible:
+ const: brcm,nvram
+
+ reg:
+ description: memory region with NVRAM data
+ maxItems: 1
+
+required:
+ - reg
+
+additionalProperties: false
+
+examples:
+ - |
+ nvram@1e000000 {
+ compatible = "brcm,nvram";
+ reg = <0x1e000000 0x10000>;
+ };
--
2.26.2