[PATCH 0/4] Actually implement nvmem support for mtd
From: Ansuel Smith
Date: Sat Sep 19 2020 - 17:50:05 EST
The mtd support for the nvmem api has been stalled from 2018 with a patch
half pushed hoping that a scheme is found for the mtd name later. This
pathset try to address this and add a very needed feature for the
My solution to the already discussed problem here  is to keep it simple.
A mtd subpartition can be set as a nvmem-provider with a specific tag and
each direct subnode is treat by the nvmem api as a nvmem-cell and gets
correctly registred. The mtd driver will treat a direct subnode of the
subpartition as a legacy subpartition of the subpartition using the
'fixed-partition' parser. To fix this every nvmem-cell has to have the
'nvmem-cell' tag and the fixed-partition parser will skip these node if
this tag is detected. Simple as that. The subpartition with the tag
'nvmem-provider' will then be set by the config to not skip the of
registration in the config and the nvmem-cells are correctly registred
and can be used to set mac-address of the devices on the system.
The last 2 patch try to address a problem in the embedded devices (mostly
routers) that have the mac-address saved in a dedicated partition and is
a ""master"" mac-address. Each device increment or decrement the extracted
mac-address based on the device number. The increment function is
implemented in the of_net function to get the mac-address that every net
driver should allready use if they don't have a trusty mac-address source.
(One example of this implementation are many ath10k device that gets the
mac-address from the art mtd partition assigned to the network driver and
increments it 1 for the wifi 2.4ghz and 2 for the wifi 5ghz).
I really hope my mtd nvmem implementation doesn't conflicts with others
and can be used, since this would remove many patch used to get mac-address
and other nvmem data.
Ansuel Smith (4):
mtd: Add nvmem support for mtd nvmem-providers
dt-bindings: mtd: partition: Document use of nvmem-provider
of_net: add mac-address-increment support
dt-bindings: net: Document use of mac-address-increment
.../devicetree/bindings/mtd/partition.txt | 59 +++++++++++++++++++
.../bindings/net/ethernet-controller.yaml | 19 ++++++
drivers/mtd/mtdcore.c | 2 +-
drivers/mtd/parsers/ofpart.c | 8 +++
drivers/of/of_net.c | 53 +++++++++++++----
5 files changed, 128 insertions(+), 13 deletions(-)