bcm53xx: backport NVMEM NVRAM driver

It supports NVRAM access described using DT binding. Right now NVRAM
data is exposed using /sys/bus/nvmem/ only.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
(cherry picked from commit 01b1b375281b77233d65eb0ebda8e4e3a1bd2407)

1 files changed, 56 insertions, 0 deletions

diff --git a/target/linux/bcm53xx/patches-5.4/080-v5.13-0001-dt-bindings-nvmem-add-Broadcom-s-NVRAM.patch b/target/linux/bcm53xx/patches-5.4/080-v5.13-0001-dt-bindings-nvmem-add-Broadcom-s-NVRAM.patch
new file mode 100644
index 0000000000..01e29aaad6
--- /dev/null
+++ b/target/linux/bcm53xx/patches-5.4/080-v5.13-0001-dt-bindings-nvmem-add-Broadcom-s-NVRAM.patch
@@ -0,0 +1,56 @@
+From c39edb9f9dcb6c8a0ba0ebf5df9e0ac93ab94b82 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Fri, 5 Mar 2021 19:32:35 +0100
+Subject: [PATCH] dt-bindings: nvmem: add Broadcom's NVRAM
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Broadcom's NVRAM structure contains device data and can be accessed
+using I/O mapping.
+
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+Reviewed-by: Rob Herring <robh@kernel.org>
+Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
+---
+ .../devicetree/bindings/nvmem/brcm,nvram.yaml | 34 +++++++++++++++++++
+ 1 file changed, 34 insertions(+)
+ create mode 100644 Documentation/devicetree/bindings/nvmem/brcm,nvram.yaml
+
+--- /dev/null
++++ b/Documentation/devicetree/bindings/nvmem/brcm,nvram.yaml
+@@ -0,0 +1,34 @@
++# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
++%YAML 1.2
++---
++$id: http://devicetree.org/schemas/nvmem/brcm,nvram.yaml#
++$schema: http://devicetree.org/meta-schemas/core.yaml#
++
++title: Broadcom's NVRAM
++
++description: |
++  Broadcom's NVRAM is a structure containing device specific environment
++  variables. It is used for storing device configuration, booting parameters
++  and calibration data.
++
++  NVRAM can be accessed on Broadcom BCM47xx MIPS and Northstar ARM Cortex-A9
++  devices usiong I/O mapped memory.
++
++maintainers:
++  - Rafał Miłecki <rafal@milecki.pl>
++
++allOf:
++  - $ref: "nvmem.yaml#"
++
++properties:
++  compatible:
++    const: brcm,nvram
++
++unevaluatedProperties: false
++
++examples:
++  - |
++    nvram@1eff0000 {
++            compatible = "brcm,nvram";
++            reg = <0x1eff0000 0x10000>;
++    };