[PATCH v4 00/16] Add support for NVMEM API

[Sean Anderson]

This adds support for the nvmem-cells properties cropping up in manyb
device trees. This is an easy way to load configuration, version
information, or calibration data from a non-volatile memory source. For
more information, refer to patch 6 ("misc: Add support for nvmem
cells").

For the moment I have only added some integration tests using the
ethernet addresses. This hits the main code paths (looking up nvmem
cells) but doesn't test writing. I can add a few stand-alone tests if
desired.

CI: https://dev.azure.com/u-boot/u-boot/_build/results?buildId=4167&view=results

The patches are structured in the following manner:
1-9:   These are general cleanups, and may be applied independently of
       the rest of the series.
10-12: Add NVMEM support
13-15: Support reading ethernet addresses using the NVMEM API and add
       some tests.
16:    Example demonstrating how this series could be reworked to be a
       uclass. It should not be applied.

Changes in v4:
- Fix dm_test_alias_highest_id test failing because we changed the
  number of aliases
- Fix segmentation fault if DSA master fails to probe
- Add fallbacks for i2c_eeprom_* functions. This fixes build errors if
  CONFIG_I2C_EEPROM was not enabled.
- Fix failing to find nvmem devices if some supported uclasses were not
  enabled.
- Remove typedefs from documentation
- Document some of the design background, and why a new uclass was not
  created.
- Enable CONFIG_NVMEM for sandbox_spl_defconfig
- Enable CONFIG_I2C_EEPROM for sandbox_spl_defconfig
- Add RFC patch illustrating how this series could be reworked to use a
  more conventional, uclass-based approach.

Changes in v3:
- Add aliases for ethernet devices
- Add mac address for eth8 to environment
- Move patch adding test earlier in the series
- Add test for eth8 as well

Changes in v2:
- Call the appropriate API functions directly from
  nvmem_cell_(read|write). This means we can drop the nvmem_interface
  machinery.

Sean Anderson (16):
  sandbox: net: Add aliases for ethernet devices
  sandbox: net: Add mac address for eth8 to environment
  test: eth: Add test for ethernet addresses
  sandbox: net: Remove fake-host-hwaddr
  sandbox: Remove eth2addr from environment
  sandbox: Move some mac addresses to device tree
  net: dsa: Fix segmentation fault if master fails to probe
  misc: i2c_eeprom: Make i2c_eeprom_write use a const buf
  misc: i2c_eeprom: Add fallbacks
  misc: Add support for nvmem cells
  sandbox: Enable NVMEM
  net: Add support for reading mac addresses from nvmem cells
  test: Load mac address with i2c eeprom
  test: Load mac address using RTC
  test: Load mac address using misc device
  [RFC] misc: nvmem: Convert to using udevices

 MAINTAINERS                        |   7 ++
 arch/sandbox/dts/sandbox.dts       |   1 -
 arch/sandbox/dts/sandbox64.dts     |   1 -
 arch/sandbox/dts/test.dts          |  34 +++++-
 board/sandbox/sandbox.env          |   4 -
 configs/sandbox64_defconfig        |   1 +
 configs/sandbox_defconfig          |   1 +
 configs/sandbox_flattree_defconfig |   1 +
 configs/sandbox_noinst_defconfig   |   1 +
 configs/sandbox_spl_defconfig      |   3 +
 doc/api/index.rst                  |   1 +
 doc/api/nvmem.rst                  |   7 ++
 drivers/misc/Kconfig               |  16 +++
 drivers/misc/Makefile              |   1 +
 drivers/misc/i2c_eeprom.c          |  40 ++++++-
 drivers/misc/i2c_eeprom_emul.c     |   4 +
 drivers/misc/misc-uclass.c         |  58 ++++++++-
 drivers/misc/misc_sandbox.c        |   3 +
 drivers/misc/nvmem.c               | 106 +++++++++++++++++
 drivers/net/sandbox.c              |  10 +-
 drivers/rtc/i2c_rtc_emul.c         |  10 ++
 drivers/rtc/rtc-uclass.c           |  46 ++++++-
 include/dm/uclass-id.h             |   1 +
 include/i2c_eeprom.h               |  27 ++++-
 include/nvmem.h                    | 185 +++++++++++++++++++++++++++++
 net/dsa-uclass.c                   |   6 +-
 net/eth-uclass.c                   |  13 +-
 test/dm/eth.c                      |  29 +++++
 test/dm/test-fdt.c                 |   2 +-
 29 files changed, 584 insertions(+), 35 deletions(-)
 create mode 100644 doc/api/nvmem.rst
 create mode 100644 drivers/misc/nvmem.c
 create mode 100644 include/nvmem.h

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2.35.1.1320.gc452695387.dirty