[0/8] nvmem: add ethernet address offset support

Message

Michael Walle Dec. 28, 2021, 2:25 p.m. UTC

This is my second attempt to solve the use case where there is only the
base MAC address stored in an EEPROM or similar storage provider. This
is the case for the Kontron sl28 board and multiple openwrt supported
boards.

Introduce an NVMEM transformation op. This can then be used to parse or
swap bytes of the NVMEM cell value. A transformation might also have
multiple output values, like in the base mac address case. It reads the mac
address from the nvmem storage and generates multiple individual addresses,
i.e. on our board we reserve 8 consecutive addresses. These addresses then
can be assigned to different network interfaces. To make it possible to
reference different values we need to introduce an argument to the phandle.
This additional argument is then an index which is can be used by the
transformation op.

Previous discussion can be found here:
https://lore.kernel.org/linux-devicetree/[e-mail]/

Michael Walle (8):
  of: base: add of_parse_phandle_with_optional_args()
  dt-bindings: nvmem: add transformation bindings
  nvmem: core: add an index parameter to the cell
  nvmem: core: add transformations support
  net: add helper eth_addr_add()
  nvmem: transformations: ethernet address offset support
  arm64: dts: ls1028a: sl28: get MAC addresses from VPD
  arm64: defconfig: enable NVMEM transformations

 .../devicetree/bindings/mtd/mtd.yaml          |  7 +-
 .../bindings/nvmem/nvmem-transformations.yaml | 46 ++++++++++++
 .../fsl-ls1028a-kontron-kbox-a-230-ls.dts     |  8 ++
 .../fsl-ls1028a-kontron-sl28-var1.dts         |  2 +
 .../fsl-ls1028a-kontron-sl28-var2.dts         |  4 +
 .../fsl-ls1028a-kontron-sl28-var4.dts         |  2 +
 .../freescale/fsl-ls1028a-kontron-sl28.dts    | 17 +++++
 arch/arm64/configs/defconfig                  |  1 +
 drivers/nvmem/Kconfig                         |  7 ++
 drivers/nvmem/Makefile                        |  1 +
 drivers/nvmem/core.c                          | 44 ++++++++---
 drivers/nvmem/imx-ocotp.c                     |  4 +-
 drivers/nvmem/transformations.c               | 73 +++++++++++++++++++
 drivers/of/base.c                             | 23 ++++++
 include/linux/etherdevice.h                   | 14 ++++
 include/linux/nvmem-provider.h                | 13 +++-
 include/linux/of.h                            | 12 +++
 17 files changed, 260 insertions(+), 18 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/nvmem/nvmem-transformations.yaml
 create mode 100644 drivers/nvmem/transformations.c