[PATCH v8 0/4] backlight: add new max25014 backlight driver

Maud Spierings via B4 Relay
2026-04-07T14:41:46Z

The Maxim MAX25014 is an automotive grade backlight driver IC. Its
datasheet can be found at [1].

With its integrated boost controller, it can power 4 channels (led
strings) and has a number of different modes using pwm and or i2c.
Currently implemented is only i2c control.

link: https://www.analog.com/media/en/technical-documentation/data-sheets/MAX25014.pdf [1]

Signed-off-by: Maud Spierings <maudspierings@gocontroll.com>
---
Changes in v8:
- Clean up some leftovers from the led subnodes, address/size-cells (Rob)
- Add Robs rb tag
- Add Daniels rb tag
- Bring the Kconfig option in line text wise with other drivers
- Rebase on the latest next
- Link to v7: https://lore.kernel.org/r/20260123-max25014-v7-0-15e504b9acc7@gocontroll.com

Changes in v7:
- remove the led subnodes
- always enable the regulator by using devm_regulator_get_enable()
- remove the no longer required gotos and simplify early returns
- fix the name of the SHORTED_LED error field
- fix the name of the SHORTGND error field
- use the proper backlight helper functions for setting/getting
brightness
- Link to v6: https://lore.kernel.org/r/20251201-max25014-v6-0-88e3ac8112ff@gocontroll.com

Changes in v6:
- fixup changes in v4 where default brightness handling was changed but
not noted
- remove leftover comment about initializing brightness
- use BIT definitions for fields in the DIAG register
- apply reverse christmas tree initialization of local variables
- remove !=0 from checks, just check if (ret)
- remove > 0 from checks, just check if (val)
- use dev_err_probe() more
- set enable gpio high in the get() instead of seperately calling set()
- change usleep_range() to fsleep()
- remove null checks when setting gpio value
- get regular regulator, not optional to avoid further NULL checks in
case none is provided
- introduce max25014_initial_power_state() to check if the bootloader
has already initialized the backlight and to correctly set props.power
- squash max25014_register_control() into max25014_update_status()
- in max25014_configure() perform extra checking on the DISABLE register
now that the state from the bootloader is taken into account
- Link to v5: https://lore.kernel.org/r/20251107-max25014-v5-0-9a6aa57306bf@gocontroll.com

Changes in v5:
- moved comment about current functions of the driver to the actual
comment section of the commit
- fixed the led@0 property, regex patternProperty is not needed as of
now
- added extra clarification about the ISET field/register
- moved #address-cells and #size-cells to the correct location
- remove leftover default-brightness in backlight nodes
- Link to v4: https://lore.kernel.org/r/20251009-max25014-v4-0-6adb2a0aa35f@gocontroll.com

Changes in v4:
- remove setting default brightness, let backlight core take care of it
- use a led node to describe the backlight
- use led-sources to enable specific channels
- also wait 2ms when there is a supply but no enable
- change dev_warn() to dev_err() in error path in max25014_check_errors()
- set backlight_properties.scale to BACKLIGHT_SCALE_LINEAR
- rebase latest next
- add address-cells and size-cells to i2c4 in av101hdt-a10.dtso
- Link to v3: https://lore.kernel.org/r/20250911-max25014-v3-0-d03f4eba375e@gocontroll.com

Changes in v3:
- fixed commit message type intgrated -> integrated
- added maximum and description to maxim,iset-property
- dropped unused labels and pinctrl in bindings example
- put the compatible first in the bindings example and dts
- removed brackets around defines
- removed the leftover pdata struct field
- removed the initial_brightness struct field
- Link to v2: https://lore.kernel.org/r/20250819-max25014-v2-0-5fd7aeb141ea@gocontroll.com

Changes in v2:
- Remove leftover unused property from the bindings example
- Complete the bindings example with all properties
- Remove some double info from the maxim,iset property
- Remove platform_data header, fold its data into the max25014 struct
- Don't force defines to be unsigned
- Remove stray struct max25014 declaration
- Remove chipname and device from the max25014 struct
- Inline the max25014_backlight_register() and strings_mask() functions
- Remove CONFIG_OF ifdef
- Link to v1: https://lore.kernel.org/r/20250725-max25014-v1-0-0e8cce92078e@gocontroll.com

---
Maud Spierings (4):
dt-bindings: backlight: Add max25014 support
backlight: add max25014atg backlight
arm64: dts: freescale: moduline-display-av101hdt-a10: add backlight
arm64: dts: freescale: moduline-display-av123z7m-n17: add backlight

.../bindings/leds/backlight/maxim,max25014.yaml | 83 +++++
MAINTAINERS | 6 +
...x8p-ml81-moduline-display-106-av101hdt-a10.dtso | 24 ++
...x8p-ml81-moduline-display-106-av123z7m-n17.dtso | 19 +-
drivers/video/backlight/Kconfig | 7 +
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/max25014.c | 377 +++++++++++++++++++++
7 files changed, 516 insertions(+), 1 deletion(-)
---
base-commit: f3e6330d7fe42b204af05a2dbc68b379e0ad179e
change-id: 20250626-max25014-4207591e1af5

Best regards,
--
Maud Spierings <maudspierings@gocontroll.com>