On 11/7/25 19:16, Conor Dooley wrote:

On Fri, Nov 07, 2025 at 01:49:58PM +0100, Maud Spierings via B4 Relay wrote:

quoted

From: Maud Spierings <maudspierings@gocontroll.com>

The Maxim MAX25014 is a 4-channel automotive grade backlight driver IC
with integrated boost controller.

Signed-off-by: Maud Spierings <maudspierings@gocontroll.com>

---

In the current implementation the control registers for channel 1,
control all channels. So only one led subnode with led-sources is
supported right now. If at some point the driver functionality is
expanded the bindings can be easily extended with it.

I'm sorry if I asked this before and forgot or w/e, but how backwards
compatible is this? If they control all channels and it gets changed to
only control channel one, how will a changed kernel understand the
difference between a new devicetree that only wants to control channel 1
and an old devicetree that is trying to use channel 1 to control all
channels?

The idea is that an implementation like that will add multiple led@ 
subnodes without the led-sources property.

So devicetrees controlled by one channel will still have only one led 
with multiple sources in the devicetree.

Kind regards,
Maud

quoted

---
  .../bindings/leds/backlight/maxim,max25014.yaml    | 107 +++++++++++++++++++++
  MAINTAINERS                                        |   5 +
  2 files changed, 112 insertions(+)

diff --git a/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml b/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
new file mode 100644
index 000000000000..e83723224b07
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml

@@ -0,0 +1,107 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/backlight/maxim,max25014.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Maxim max25014 backlight controller
+
+maintainers:
+  - Maud Spierings <maudspierings@gocontroll.com>
+
+properties:
+  compatible:
+    enum:
+      - maxim,max25014
+
+  reg:
+    maxItems: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  enable-gpios:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  power-supply:
+    description: Regulator which controls the boost converter input rail.
+
+  pwms:
+    maxItems: 1
+
+  maxim,iset:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 15
+    default: 11
+    description:
+      Value of the ISET field in the ISET register. This controls the current
+      scale of the outputs, a higher number means more current.
+
+  led@0:
+    type: object
+    description: Properties for a string of connected LEDs.
+    $ref: common.yaml#
+
+    properties:
+      reg:
+        const: 0
+
+      led-sources:
+        allOf:
+          - minItems: 1
+            maxItems: 4
+            items:
+              minimum: 0
+              maximum: 3
+            default: [0, 1, 2, 3]
+
+      default-brightness:
+        minimum: 0
+        maximum: 100
+        default: 50
+
+    required:
+      - reg
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        backlight@6f {
+            compatible = "maxim,max25014";
+            reg = <0x6f>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+            enable-gpios = <&gpio1 4 GPIO_ACTIVE_HIGH>;
+            interrupt-parent = <&gpio1>;
+            interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
+            power-supply = <&reg_backlight>;
+            pwms = <&pwm1>;
+            maxim,iset = <7>;
+
+            led@0 {
+                reg = <0>;
+                led-sources = <0 1 2 3>;
+                default-brightness = <50>;
+            };
+        };
+    };

diff --git a/MAINTAINERS b/MAINTAINERS
index 58c7e3f678d8..606ce086f758 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS

@@ -15261,6 +15261,11 @@ F:	Documentation/userspace-api/media/drivers/max2175.rst
  F:	drivers/media/i2c/max2175*
  F:	include/uapi/linux/max2175.h
  
+MAX25014 BACKLIGHT DRIVER
+M:	Maud Spierings <maudspierings@gocontroll.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
+
  MAX31335 RTC DRIVER
  M:	Antoniu Miclaus <antoniu.miclaus@analog.com>
  L:	linux-rtc@vger.kernel.org

-- 
2.51.2