Hi Peter, it could indeed cause problems when VDD1 != VDD2 and at both needs to be enabled. The pca9846 datasheet seems to refer to VDD1 as VDD. Thus I could add an optional "vdd2" regulator to the binding and driver. Please let me know if that's what you had in mind. Regards, Patrick On Tue, May 2, 2023 at 8:03 AM Peter Rosin <peda@xxxxxxxxxx> wrote: > > Hi! > > 2023-05-01 at 11:15, Patrick Rudolph wrote: > > Update the pca954x bindings to add support for the Maxim MAX735x/MAX736x > > chips. The functionality will be provided by the existing pca954x driver. > > > > For chips that are powered off by default add a regulator called vdd-supply. > > > > Signed-off-by: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx> > > Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> > > --- > > .../bindings/i2c/i2c-mux-pca954x.yaml | 22 +++++++++++++++++-- > > 1 file changed, 20 insertions(+), 2 deletions(-) > > > > diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.yaml b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.yaml > > index e5c1070903ef..6fed6eae9c9b 100644 > > --- a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.yaml > > +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.yaml > > @@ -4,18 +4,29 @@ > > $id: http://devicetree.org/schemas/i2c/i2c-mux-pca954x.yaml# > > $schema: http://devicetree.org/meta-schemas/core.yaml# > > > > -title: NXP PCA954x I2C bus switch > > +title: NXP PCA954x I2C and compatible bus switches > > > > maintainers: > > - Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > > > > description: > > - The binding supports NXP PCA954x and PCA984x I2C mux/switch devices. > > + The NXP PCA954x and compatible devices are I2C bus > > + multiplexer/switches that share the same functionality > > + and register layout. > > + The devices usually have 4 or 8 child buses, which are > > + attached to the parent bus by using the SMBus "Send Byte" > > + command. > > > > properties: > > compatible: > > oneOf: > > - enum: > > + - maxim,max7356 > > + - maxim,max7357 > > + - maxim,max7358 > > + - maxim,max7367 > > + - maxim,max7368 > > + - maxim,max7369 > > - nxp,pca9540 > > - nxp,pca9542 > > - nxp,pca9543 > > @@ -56,6 +67,9 @@ properties: > > description: if present, overrides i2c-mux-idle-disconnect > > $ref: /schemas/mux/mux-controller.yaml#/properties/idle-state > > > > + vdd-supply: > > + description: A voltage regulator supplying power to the chip. > > + > > The pca9846-9 chips do not have one VDD, they have separate supplies for > "low level" (VDD1), and "core logic" (VDD2). I don't know how such a > situation is normally reflected in bindings, but could it not cause > headaches later if use of unqualified VDD is spreading for those chips? > Possibly with different semantics depending on if vdd-supply is tied to > VDD1, VDD2 or both? > > Cheers, > Peter > > > required: > > - compatible > > - reg > > @@ -68,6 +82,8 @@ allOf: > > compatible: > > contains: > > enum: > > + - maxim,max7367 > > + - maxim,max7369 > > - nxp,pca9542 > > - nxp,pca9543 > > - nxp,pca9544 > > @@ -94,6 +110,8 @@ examples: > > #size-cells = <0>; > > reg = <0x74>; > > > > + vdd-supply = <&p3v3>; > > + > > interrupt-parent = <&ipic>; > > interrupts = <17 IRQ_TYPE_LEVEL_LOW>; > > interrupt-controller;
