Add support for Actions Semi Owl socinfo

This patchset adds a socinfo driver which provides information about Actions Semi Owl SoCs to user space via sysfs: machine, family, soc_id, serial_number.

Please note the serial number is currently available only for the S500 SoC variant.

This has been tested on the S500 SoC based RoseapplePi SBC.

Thanks,
Cristi

Changes in v2:
- Exposed the memory range for reading the SoC serial number under /reserved-memory DT node, according to Rob's review; as a consequence added a new binding document (actions,owl-soc-serial.yaml) and updated owl-socinfo.yaml

- Replaced the unportable usage of system_serial_{low,high} globals with a public API to provide external access to SoC serial number parts (e.g. Owl Ethernet MAC driver will use this to generate a stable MAC address)

- Rebased patch series on v5.12-rc5

Cristian Ciocaltea (6):
dt-bindings: reserved-memory: Add Owl SoC serial number binding
dt-bindings: soc: actions: Add Actions Semi Owl socinfo binding
soc: actions: Add Actions Semi Owl socinfo driver
arm: dts: owl-s500: Add reserved-memory range for Owl SoC serial
number
arm: dts: owl-s500: Add socinfo support
MAINTAINERS: Add entries for Owl reserved-memory and socinfo bindings

 .../actions,owl-soc-serial.yaml               |  53 ++++++
 .../bindings/soc/actions/owl-socinfo.yaml     |  57 +++++++
 MAINTAINERS                                   |   2 +
 arch/arm/boot/dts/owl-s500.dtsi               |  13 +-
 drivers/soc/actions/Kconfig                   |   8 +
 drivers/soc/actions/Makefile                  |   1 +
 drivers/soc/actions/owl-socinfo.c             | 152 ++++++++++++++++++
 include/linux/soc/actions/owl-serial-number.h |  20 +++
 8 files changed, 305 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/reserved-memory/actions,owl-soc-serial.yaml
 create mode 100644 Documentation/devicetree/bindings/soc/actions/owl-socinfo.yaml
 create mode 100644 drivers/soc/actions/owl-socinfo.c
 create mode 100644 include/linux/soc/actions/owl-serial-number.h

2.31.1