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linux/Documentation/devicetree/bindings/nvmem/brcm,nvram.yaml
Rafał Miłecki 1d53afe387 dt-bindings: nvmem: brcm,nvram: add #nvmem-cell-cells for MACs
Broadcom's NVRAM contains MACs for Ethernet interfaces. Those MACs are
usually base addresses that are also used for calculating other MACs.

For example if a router vendor decided to use gmac0 it most likely
programmed NVRAM of each unit with a proper "et0macaddr" value. That is
a base.

Ethernet interface is usually connected to switch port. Switch usually
includes few LAN ports and a WAN port. MAC of WAN port gets calculated
as relative address to the interface one. Offset varies depending on
device model.

Wireless MACs may also need to be calculated using relevant offsets.

To support all those scenarios let MAC NVMEM cells be referenced with an
index specifying MAC offset. Disallow additionalProperties while at it.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Message-ID: <20230611140330.154222-4-srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-15 13:42:16 +02:00

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1.7 KiB
YAML

# 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.
NVRAM variables can be defined as NVMEM device subnodes.
maintainers:
- Rafał Miłecki <rafal@milecki.pl>
allOf:
- $ref: nvmem.yaml#
properties:
compatible:
const: brcm,nvram
reg:
maxItems: 1
board_id:
type: object
description: Board identification name
et0macaddr:
type: object
description: First Ethernet interface's MAC address
properties:
"#nvmem-cell-cells":
description: The first argument is a MAC address offset.
const: 1
additionalProperties: false
et1macaddr:
type: object
description: Second Ethernet interface's MAC address
properties:
"#nvmem-cell-cells":
description: The first argument is a MAC address offset.
const: 1
additionalProperties: false
et2macaddr:
type: object
description: Third Ethernet interface's MAC address
properties:
"#nvmem-cell-cells":
description: The first argument is a MAC address offset.
const: 1
additionalProperties: false
unevaluatedProperties: false
examples:
- |
nvram@1eff0000 {
compatible = "brcm,nvram";
reg = <0x1eff0000 0x10000>;
mac: et0macaddr {
};
};