[PATCH v2 0/2] Add JHB100 Fan-Tach support

[Changhuang Liang <changhuang.liang@starfivetech.com>]

StarFive Fan-Tach controller can support up to 16 fan tach input.
The series has been tested on the EVB1 board.

Change since v1:
PATCH 1:
- Add explicit minItems/maxItems and range constraints for tach-ch.
- Switch fan node regex to support hex addresses.
- Add pulses-per-revolution demo.
- Rename example node to fan-controller for consistency.
- Limit the reg property to a maximum value of 15
- Fix tach-ch example by changing /bits/ 8 <0x0>, <0x8> to
  /bits/ 8 <0x0 0x8> so both values are parsed as 8-bit cells.

PATCH 2:
- Added hwmon documentation (starfive-fan-tach.rst)
- Added HAS_IOMEM dependency in Kconfig
- Added per-channel pulses-per-revolution DT property (default 2, range 1-4)
- Added mutex and spinlock for proper concurrency protection
- Added armed_stall/armed_slow mechanism to prevent spurious interrupts
- Added retry logic for zero sampling value in rpm read
- Improved probe sequence: clock enable before reset deassert
- Added devm action for remove path cleanup
- Added input validation for write operations
- Added MODULE_DEVICE_TABLE
- Added linux-hwmon mailing list to MAINTAINERS

v1: https://lore.kernel.org/all/20260428082337.743546-1-changhuang.liang@starfivetech.com/

Changhuang Liang (2):
  dt-bindings: hwmon: Add starfive,jhb100-fan-tach
  hwmon: (starfive-fan-tach) Add fan tach driver for StarFive JHB100

 .../hwmon/starfive,jhb100-fan-tach.yaml       |  93 +++
 Documentation/hwmon/index.rst                 |   1 +
 Documentation/hwmon/starfive-fan-tach.rst     |  34 ++
 MAINTAINERS                                   |   8 +
 drivers/hwmon/Kconfig                         |  14 +
 drivers/hwmon/Makefile                        |   1 +
 drivers/hwmon/starfive-fan-tach.c             | 561 ++++++++++++++++++
 7 files changed, 712 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/starfive,jhb100-fan-tach.yaml
 create mode 100644 Documentation/hwmon/starfive-fan-tach.rst
 create mode 100644 drivers/hwmon/starfive-fan-tach.c

--
2.25.1