[PATCH v5 0/3] iio: adc: qcom-pm8xxx-xoadc: add support for reading channel labels from DT

[Antony Kurniawan Soemardi]

This series adds support for reading channel labels from the device tree
in the Qualcomm PM8xxx XOADC driver, along with the corresponding DT
updates for the PM8921 PMIC. Also removes the redundant error logs when
reading values, as returning -EINVAL and -ETIMEDOUT are sufficient to
report failures.

This series also includes minor refactoring, such as removing redundant
error loggings.

Tested on Sony Xperia SP (PM8921):
> cat /sys/bus/iio/devices/iio\:device0/in_voltage7_label
usb_vbus
> cat /sys/bus/iio/devices/iio\:device0/in_temp12_label
ref_muxoff
> sensors
iio_hwmon-isa-0000
Adapter: ISA adapter
vbat:        267.86 V
dcin:          4.82 kV
...
chg_temp:    +1071.4°C

Note: the sensor readings above are incorrect due to pending calibration
fixes are not included in this series. This patch only addresses label
visibility. The values are expected to be wrong until the calibration
fixes lands separately.

---
Changes in v5:
- Drop constify pointers patch as it causes build failures
- Link to v4: https://patch.msgid.link/20260426-pm8xxx-xoadc-label-v4-0-0ec782362615@xxxxxxxxxxxxxx

Changes in v4:
- Constify pointers in read operations
- Reworked wait_for_completion_timeout() handling
- Updated variable declaration style in pm8xxx_read_label()
- Link to v3: https://lore.kernel.org/r/20260405-pm8xxx-xoadc-label-v3-0-9fe179c283ec@xxxxxxxxxxxxxx

Changes in v3:
- Simplify label assignment logic by removing the unnecessary
  conditional branch
- Remove redundant error logging in pm8xxx_read_channel_rsv, since
  -ETIMEDOUT is sufficient to report failures.
- Link to v2: https://lore.kernel.org/r/20260403-pm8xxx-xoadc-label-v2-0-29b50bf821e6@xxxxxxxxxxxxxx

Changes in v2:
- Remove redundant error logging in pm8xxx_read_raw, since -EINVAL is
  sufficient to report failures.
- Reword the uncommon Tested-by commit tag to freeform text
- Link to v1: https://lore.kernel.org/r/20260326-pm8xxx-xoadc-label-v1-0-027805dad4db@xxxxxxxxxxxxxx

Changes since original patch:
- The label is now read from the platform description (device tree)
  instead of the internal datasheet name.
- Link to original patch:
  https://lore.kernel.org/all/20251028-pm8xxx-xoadc-fix-v1-1-b000e1036e41@xxxxxxxxxxxxxx/

---
Antony Kurniawan Soemardi (3):
      ARM: dts: qcom: pm8921: add labels for ADC channels
      iio: adc: qcom-pm8xxx-xoadc: remove redundant error logs when reading values
      iio: adc: qcom-pm8xxx-xoadc: add support for reading channel labels

 arch/arm/boot/dts/qcom/pm8921.dtsi  | 12 +++++++++++
 drivers/iio/adc/qcom-pm8xxx-xoadc.c | 40 +++++++++++++++++++++----------------
 2 files changed, 35 insertions(+), 17 deletions(-)
---
base-commit: 27d128c1cff64c3b8012cc56dd5a1391bb4f1821
change-id: 20260321-pm8xxx-xoadc-label-47afdf7f06a9

Best regards,
--  
Antony Kurniawan Soemardi <linux@xxxxxxxxxxxxxx>