This v4 series continues the cleanup and scale-fix work for the AD5504
high-voltage DAC driver, addressing all outstanding feedback from the v3 review.
Jonathan Cameron applied patches 2 (sort headers alphabetically) and 4
(introduce local dev pointer) from v3 directly to iio/testing. This series
rebases on top of that state and does not re-send those patches.
Changes in v4:
* Split the formerly monolithic v3 patch 5 into four focused commits:
pdata removal, locking, ACPI/DT separation, and output-range support.
Each commit leaves the driver in a clean, bisectable state.
* Fix ACPI probe path by forking on ACPI_COMPANION() instead of relying
on the -ENODEV sentinel from the regulator framework, following the
pattern established in adc/ti-ads7950.c (David Lechner).
* Introduce a mutex via devm_mutex_init() and guard(mutex) to fix three
concurrency issues: shared DMA SPI buffers, non-atomic CTRL+NOOP write
sequences, and unprotected pwr_down_mask/pwr_down_mode state.
* Use device_property_present() to cleanly distinguish "property absent"
from "property present but malformed" when parsing
output-range-microvolt, replacing the ambiguous -EINVAL sentinel.
* Add backward compatibility fallback via
devm_regulator_get_enable_read_voltage() for old DTs that predate the
output-range-microvolt property.
* Replace <linux/device.h> with <linux/dev_printk.h> in IWYU patch
(Jonathan Cameron).
Testing:
Verified on ARM64 Raspberry Pi 5 (BCM2712) using a custom Device Tree
overlay on spi10, without physical AD5504 hardware.
60V path (output-range-microvolt = <0 60000000>):
$ cat /sys/bus/iio/devices/iio:device0/out_voltage_scale
14.648437500 (60000 mV / 4096)
30V path (output-range-microvolt = <0 30000000>):
$ cat /sys/bus/iio/devices/iio:device0/out_voltage_scale
7.324218750 (30000 mV / 4096)
Invalid range (output-range-microvolt = <0 70000000>):
[ 40.646862] ad5504 spi10.0: error -EINVAL: Invalid output-range-microvolt
[ 40.646869] ad5504 spi10.0: probe with driver ad5504 failed with error -22
Backward compatibility (no output-range-microvolt, vcc-supply = 60V):
$ cat /sys/bus/iio/devices/iio:device0/out_voltage_scale
14.648437500 (60000 mV / 4096 via regulator fallback)
Powerdown sysfs read/write and powerdown mode switching (20kohm_to_gnd,
three_state) verified on all four channels without errors.
Previous versions:
v3: https://lore.kernel.org/linux-iio/20260509142047.30302-1-0rayn.dev@gmail.com/
v2: https://lore.kernel.org/linux-iio/20260310174835.24209-1-0rayn.dev@gmail.com/
v1: https://lore.kernel.org/linux-iio/20260212181955.42724-1-0rayn.dev@gmail.com/
Thank you to Jonathan Cameron, David Lechner, Andy Shevchenko, Nuno Sá,
Krzysztof Kozlowski, and Conor Dooley for the continued reviews.
Taha Ed-Dafili (6):
dt-bindings: iio: dac: ad5504: add output-range and missing gpios
iio: dac: ad5504: Align headers with IWYU principle
iio: dac: ad5504: remove legacy platform data support
iio: dac: ad5504: introduce local lock to protect state and spi
transfers
iio: dac: ad5504: strictly separate ACPI and DT probe paths
iio: dac: ad5504: support scale via output-range-microvolt property
.../bindings/iio/dac/adi,ad5504.yaml | 39 +++++++++-
drivers/iio/dac/ad5504.c | 76 ++++++++++++++-----
include/linux/iio/dac/ad5504.h | 15 ----
3 files changed, 97 insertions(+), 33 deletions(-)
delete mode 100644 include/linux/iio/dac/ad5504.h
--
2.55.0