[PATCH v3 0/2] Add support for Texas Instruments INA4230 power monitor

[Alexey Charkov]

TI INA4230 is a 4-channel power monitor with I2C interface, similar in
operation to INA3221 (3-channel) and INA219 (single-channel) but with
a different register layout, different alerting mechanism and slightly
different support for directly reading calculated current/power/energy
values (pre-multiplied by the device itself and needing only to be scaled
by the driver depending on its selected LSB unit values).

In this initial implementation, the driver supports reading voltage,
current, power and energy values, but does not yet support alerts, which
can be added separately if needed. Also the overflows during hardware
calculations are not yet handled, nor is the support for the device's
internal 32-bit energy counter reset.

An example device tree using this binding and driver is available at [1]
(not currently upstreamed, as the device in question is in engineering
phase and not yet publicly available)

[1] https://github.com/flipperdevices/flipper-linux-kernel/blob/flipper-devel/arch/arm64/boot/dts/rockchip/rk3576-flipper-one-rev-f0b0c1.dts

Signed-off-by: Alexey Charkov <alchark@xxxxxxxxxxx>
---
Changes in v3:
- Updated the description of the ti,maximum-expected-current-microamp property
  in the binding to clarify how it is used, and drop the irrelevant mention of
  the PMbus (Guenter Roeck)
- Use div64_u64() instead of do_div() for the final division in the calibration value
  calculation to avoid overflows in the denominator (Guenter Roeck)
- Avoid overflow while scaling the voltage values on 32-bit platforms (Guenter Roeck)
- Use regmap_noinc_read() instead of regmap_raw_read() for reading the energy values
  to ensure that the regmap / bus driver don't wander off to adjacent registers
  during the read operation (on INA4230 the whole 32 bits should be read from
  the same register offset) (Guenter Roeck)
- Remove redundant call to ina4230_set_calibration() in the current read path,
  as the calibration value is already set when enabling the channel and restored
  across PM changes via regcache_sync() (Guenter Roeck)
- Add missing write_enable() function to make hwmon_in_enable writes work as
  advertised in is_visible() (Guenter Roeck)
- Add a check for disabled channels before calling pm_runtime_put_noidle() on them
  to avoid refcount underflow due to imbalanced get_sync/put_noidle calls (Guenter Roeck)
- Dropped unused include of linux/debugfs.h
- Add missing return checks on regmap_write() calls
- uO -> uOhm in the error message to avoid confusion
- Move probe-time calibration after enabling runtime PM to avoid it being reverted
  by the PM sync
- Link to v2: https://lore.kernel.org/r/20260302-ina4230-v2-0-55b49d19d2ab@xxxxxxxxxxx

Changes in v2:
- Replace u64/u64 division with do_div() (kernel test robot)
- Add an example with ti,maximum-expected-current-microamp property in
  bindings (Krzysztof Kozlowski)
- Include the newly added binding in MAINTAINERS file (Krzysztof Kozlowski)
- Use dev_err_probe() where appropriate in the driver (Krzysztof Kozlowski)
- Switch to devm_regmap_field_bulk_alloc() instead of an open-coded loop
- Add a bounds check for the calculated calibration value,
  and a corresponding error message
- Link to v1: https://lore.kernel.org/r/20260225-ina4230-v1-0-92b1de981d46@xxxxxxxxxxx

---
Alexey Charkov (2):
      dt-bindings: hwmon: Add TI INA4230 4-channel I2C power monitor
      hwmon: Add support for TI INA4230 power monitor

 .../devicetree/bindings/hwmon/ti,ina4230.yaml      |  134 +++
 MAINTAINERS                                        |    7 +
 drivers/hwmon/Kconfig                              |   11 +
 drivers/hwmon/Makefile                             |    1 +
 drivers/hwmon/ina4230.c                            | 1066 ++++++++++++++++++++
 5 files changed, 1219 insertions(+)
---
base-commit: 343f51842f4ed7143872f3aa116a214a5619a4b9
change-id: 20260219-ina4230-74a02409153d

Best regards,
-- 
Alexey Charkov <alchark@xxxxxxxxxxx>