[PATCH v4 0/2] iio: adc: Add the Ingenic X1600 ADC

[Olivier Louvignes]

A driver for the SAR ADC of the Ingenic X1600: four auxiliary channels,
12 bits, one interrupt per channel. Tested on a HiBy R1, whose keys are on
channel 0 behind adc-keys.

As in v3, this version is X1600-only. The X1830 and the X2000 have the
same register layout by their programming manuals, and a chip_info with
the channel count and the resolution can add them later, with a test on
either.

Changes in v4:
- The Kconfig prompt, the header comment and MODULE_DESCRIPTION() are
  the same text (Andy).
- The read computes the data register's bank and half next to each
  other, and the two macros take them (Andy).
- X1600_ADC_CLK_RATE_HZ (Andy).
- Read and write helpers that add the base (Andy). Plain MMIO rather
  than regmap: nothing is cached or shared, and the only
  read-modify-writes are under the conversion mutex or in probe.
- The device clock rate is clamped before dividing (Andy); the divider
  comes out the same for every rate.
- Binding: the description's last sentence and clock-names dropped; the
  driver takes its one clock unnamed (Krzysztof on v2 and Conor on v1:
  their reviews and v3 crossed).
- Joshua's Reviewed-by on patch 2: the changes to it are the points
  above, with no change in behaviour.

Changes in v3:
- Cover letter (Andy, Joshua).
- MAINTAINERS: no list line; the binding's path in patch 1, the driver's
  in patch 2 (Joshua).
- Includes for what the driver uses, copyright line, MODULE_AUTHOR(),
  reverse xmas tree, open-coded return, no message after
  devm_request_irq(), a blank line (Joshua; Andy on the return).
- fsleep(2 * USEC_PER_MSEC) (Andy).
- The ADC clock divider is now even, as the X1600 programming manual
  has it; v2 wrote the divider minus one, as the vendor kernel does. The
  divider fields are named as in the manual, and the two clocks only
  repeated sampling uses stay at their reset values.
- The probe comment on staying powered up no longer names the keys
  (Jonathan).

Changes in v2 (Jonathan):
- The comparison with the JZ47xx ADCs dropped from the file header.
- No mod_devicetable.h include.
- X1600_ADC_VREF_mV.
- The status declaration split from its readl() in the interrupt
  handler.
- field_get() for the channel's result.
- fsleep(2000) instead of usleep_range().

v3: https://lore.kernel.org/all/20261026083631.48406-1-olivier@xxxxxxxxx/
v2: https://lore.kernel.org/all/20261024041357.34346-1-olivier@xxxxxxxxx/
v1: https://lore.kernel.org/all/20261023204209.48556-1-olivier@xxxxxxxxx/

Olivier Louvignes (2):
  dt-bindings: iio: adc: Add the Ingenic X1600 ADC
  iio: adc: Add a driver for the Ingenic X1600 ADC

 .../bindings/iio/adc/ingenic,x1600-adc.yaml   |  53 ++++
 MAINTAINERS                                   |   6 +
 drivers/iio/adc/Kconfig                       |  10 +
 drivers/iio/adc/Makefile                      |   1 +
 drivers/iio/adc/ingenic-x1600-adc.c           | 257 ++++++++++++++++++
 5 files changed, 327 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/ingenic,x1600-adc.yaml
 create mode 100644 drivers/iio/adc/ingenic-x1600-adc.c


base-commit: a3b3580713f3ac5a32dc2874ee546828977a1d68
-- 
2.54.0