Re: [PATCH v1 5/5] dt-bindings: leds: Document TI LM3560 Synchronous Boost Flash Driver
From: Sakari Ailus
Date: Fri Apr 17 2026 - 08:36:22 EST
Hi Svyatoslav,
On Fri, Apr 17, 2026 at 03:30:30PM +0300, Svyatoslav Ryhel wrote:
> пт, 17 квіт. 2026 р. о 15:13 Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> пише:
> >
> > Hi Svyatoslav,
> >
> > Thanks for the set.
> >
> > This patch should be the first one in the set, or at least before those
> > using the bindings defined here.
> >
>
> Maybe before conversion, but definitely not the first. I would like to
> avoid patch multiplication caused by schema adjustments after every
> single commit if possible.
You don't have to use all the properties defined but you can't use
properties in drivers not yet defined in bindings.
>
> > On Fri, Apr 17, 2026 at 02:42:26PM +0300, Svyatoslav Ryhel wrote:
> > > Document TI LM3560 Synchronous Boost Flash Driver used for camera flash
> > > LEDs.
> > >
> > > Signed-off-by: Svyatoslav Ryhel <clamor95@xxxxxxxxx>
> > > ---
> > > .../devicetree/bindings/leds/ti,lm3560.yaml | 134 ++++++++++++++++++
> > > 1 file changed, 134 insertions(+)
> > > create mode 100644 Documentation/devicetree/bindings/leds/ti,lm3560.yaml
> > >
> > > diff --git a/Documentation/devicetree/bindings/leds/ti,lm3560.yaml b/Documentation/devicetree/bindings/leds/ti,lm3560.yaml
> > > new file mode 100644
> > > index 000000000000..460ea1fbc1e5
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/leds/ti,lm3560.yaml
> > > @@ -0,0 +1,134 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/leds/ti,lm3560.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: TI LM3560 Synchronous Boost Flash Driver
> > > +
> > > +maintainers:
> > > + - Svyatoslav Ryhel <clamor95@xxxxxxxxx>
> > > +
> > > +description:
> > > + The LM3560 is a 2-MHz fixed frequency synchronous boost converter with two
> > > + 1000-mA constant current drivers for high-current white LEDs. The dual high-
> > > + side current sources allow for grounded cathode LED operation and can be
> > > + tied together for providing flash currents at up to 2 A through a single LED.
> > > + An adaptive regulation method ensures the current for each LED remains in
> > > + regulation and maximizes efficiency.
> > > +
> > > +properties:
> > > + compatible:
> > > + enum:
> > > + - ti,lm3559
> > > + - ti,lm3560
> > > +
> > > + reg:
> > > + maxItems: 1
> > > +
> > > + '#address-cells':
> > > + const: 1
> > > +
> > > + '#size-cells':
> > > + const: 0
> > > +
> > > + enable-gpios:
> > > + description: GPIO connected to the HWEN pin.
> > > + maxItems: 1
> > > +
> > > + vin-supply:
> > > + description: Supply connected to the IN line.
> > > +
> > > + ti,peak-current-microamp:
> > > + description:
> > > + The LM3560 features 4 selectable current limits 1.6A, 2.3A, 3A, and 3.6A.
> > > + When the current limit is reached, the LM3560 stops switching for the
> > > + remainder of the switching cycle.
> > > + enum: [16000000, 23000000, 30000000, 36000000]
> > > + default: 36000000
> > > +
> > > + ti,max-flash-timeout-ms:
> > > + description:
> > > + Maximum flash timeout in ms with step 32ms.
> > > + minimum: 32
> > > + maximum: 1024
> > > + default: 1024
> > > +
> > > +patternProperties:
> > > + '^led@[01]$':
> > > + description: LED control bank nodes.
> > > + $ref: /schemas/leds/common.yaml#
> > > + unevaluatedProperties: false
> > > +
> > > + properties:
> > > + reg:
> > > + description: Control bank selection (0 = bank A, 1 = bank B).
> > > + maximum: 1
> > > +
> > > + ti,max-flash-current-microamp:
> > > + description:
> > > + Maximum flash current in uA with step 62500uA.
> > > + minimum: 62500
> > > + maximum: 1000000
> > > + default: 1000000
> > > +
> > > + ti,max-torch-current-microamp:
> >
> > Don't the LED flash bindings already have standardised properties for
> > these?
> >
>
> Oh, they do! Thanks for pointing out. led-max-microamp,
> flash-max-microamp and flash-max-timeout-us. Very nice, I will adjust
> in the v2.
Sounds good, thanks!
I think it'd be worth standardising maximum input current, too, as other
devices use it, too.
>
> > > + description:
> > > + Maximum flash current in uA with step 31250uA.
> > > + minimum: 31250
> > > + maximum: 250000
> > > + default: 250000
> > > +
> > > + required:
> > > + - reg
> >
> > I'd say the max current properties are required as well, same for the
> > timeouts. Or make the lowest the default. The lowest values are very seldom
> > used in practice though.
> >
>
> I have transferred from the driver which uses maximum values as
> default one. I can change to minimum if needed, that is not a big
> deal.
I'd just make these mandatory.
>
> > > +
> > > +required:
> > > + - compatible
> > > + - reg
> > > + - '#address-cells'
> > > + - '#size-cells'
> > > +
> > > +additionalProperties: false
> > > +
> > > +examples:
> > > + - |
> > > + #include <dt-bindings/gpio/gpio.h>
> > > +
> > > + i2c {
> > > + #address-cells = <1>;
> > > + #size-cells = <0>;
> > > +
> > > + led-controller@53 {
> > > + compatible = "ti,lm3560";
> > > + reg = <0x53>;
> > > +
> > > + enable-gpios = <&gpio 28 GPIO_ACTIVE_HIGH>;
> > > + vin-supply = <&vdd_3v3_sys>;
> > > +
> > > + ti,peak-current-microamp = <16000000>;
> > > + ti,max-flash-timeout-ms = <1024>;
> > > +
> > > + #address-cells = <1>;
> > > + #size-cells = <0>;
> > > +
> > > + led@0 {
> > > + reg = <0>;
> > > +
> > > + label = "white::flash";
> > > + linux,default-trigger = "flash";
> > > +
> > > + ti,max-flash-current-microamp = <562500>;
> > > + ti,max-torch-current-microamp = <156250>;
> > > + };
> > > +
> > > + led@1 {
> > > + reg = <1>;
> > > +
> > > + label = "yellow::flash";
> > > + linux,default-trigger = "flash";
> > > +
> > > + ti,max-flash-current-microamp = <562500>;
> > > + ti,max-torch-current-microamp = <156250>;
> > > + };
> > > + };
> > > + };
> >
> > --
> > Kind regards,
> >
> > Sakari Ailus
--
Kind regards,
Sakari Ailus