[PATCH v2 0/3] thermal/drivers/sun8i: Add support for the Allwinner A80 thermal sensor

From: FuginInsanE <[email protected]>

This series adds support for the thermal sensor of the Allwinner A80
(sun9i), the last SoC of the family with an in-tree DT but no THS
support.

The A80 THS is an early relative of the A83T/H3-era sensor generation:
same register semantics, but the block, bus gate, module clock and
reset line are shared with the GPADC, the THS registers start at
offset 0x40, and there are four sensors (big cluster, DRAM, GPU,
little cluster).

Philipp Rossak posted a driver for this hardware back in 2018 as part
of a larger THS rework which never landed for the A80; Armbian has
been carrying his DT patches ever since. This series takes the
mainline sun8i_thermal driver as the base instead: patch 2 adds a
chip description derived from the vendor BSP (register init values,
protection thresholds and the temperature formula), and patch 3
revives Philipp's DT patch with a fixed interrupt number (SPI 115 as
in the vendor BSP - verified on hardware, the original SPI 31 never
fires) and critical trip points.

The A80 SID is not yet supported by the sunxi nvmem driver, so
calibration data is unavailable for now and the driver falls back to
defaults, which produce plausible values on real hardware.

Tested on a Cubietech Cubieboard4: all four zones report
load-reactive temperatures (idle ~40 degC, ~54 degC under sustained
full load) tracking the BSP formula across the range we could
provoke.

Changes in v2:
- Guard the calibrate callback invocation in sun8i_ths_calibrate()
  against chips without a calibrate op (would have oopsed if a
  calibration nvmem cell were ever added for the A80)
- Do not enable the alarm interrupt: being level triggered it would
  retrigger at conversion rate for as long as an over-temperature
  condition persists; only the emergency shutdown interrupt remains
  enabled
- Note: the unconditional IRQ_HANDLED in the existing interrupt
  handler predates this series and is left untouched here

Philipp Rossak (1):
  ARM: dts: sun9i-a80: Add thermal sensor and thermal zones

Sören Hantel (2):
  dt-bindings: thermal: sun8i: Add binding for the A80 THS controller
  thermal/drivers/sun8i: Add support for the A80 THS

 .../thermal/allwinner,sun8i-a83t-ths.yaml     |  1 +
 arch/arm/boot/dts/allwinner/sun9i-a80.dtsi    | 68 +++++++++++++
 drivers/thermal/sun8i_thermal.c               | 98 ++++++++++++++++++-
 3 files changed, 166 insertions(+), 1 deletion(-)

-- 
2.43.0