From c00b72491366529be722de20679b169c4f479f39 Mon Sep 17 00:00:00 2001 From: Jacopo Mondi Date: Thu, 14 Jan 2021 18:04:26 +0100 Subject: [PATCH] media: dt-bindings: media: max9286: Document 'maxim,reverse-channel-microvolt' Document the 'maxim,reverse-channel-microvolt' vendor property in the bindings document of the max9286 driver. The newly introduced property allows to specify the initial configuration of the GMSL reverse control channel to accommodate remote serializers pre-programmed with the high threshold power supply noise immunity enabled. Reviewed-by: Rob Herring Reviewed-by: Laurent Pinchart Reviewed-by: Kieran Bingham Signed-off-by: Jacopo Mondi Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- .../bindings/media/i2c/maxim,max9286.yaml | 22 +++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml index bf4fa56ffcc7..ee16102fdfe7 100644 --- a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml +++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml @@ -50,6 +50,26 @@ properties: '#gpio-cells': const: 2 + maxim,reverse-channel-microvolt: + minimum: 30000 + maximum: 200000 + default: 170000 + description: | + Initial amplitude of the reverse control channel, in micro volts. + + The initial amplitude shall be adjusted to a value compatible with the + configuration of the connected remote serializer. + + Some camera modules (for example RDACM20) include an on-board MCU that + pre-programs the embedded serializer with power supply noise immunity + (high-threshold) enabled. A typical value of the deserializer's reverse + channel amplitude to communicate with pre-programmed serializers is + 170000 micro volts. + + A typical value for the reverse channel amplitude to communicate with + a remote serializer whose high-threshold noise immunity is not enabled + is 100000 micro volts + ports: $ref: /schemas/graph.yaml#/properties/ports @@ -185,6 +205,8 @@ examples: gpio-controller; #gpio-cells = <2>; + maxim,reverse-channel-microvolt = <170000>; + ports { #address-cells = <1>; #size-cells = <0>;