On Fri, Oct 18, 2019 at 1:24 PM Linus Walleij <linus.walleij@xxxxxxxxxx> wrote: > > This adds a starting point for processing and defining generic > bindings used by DSI panels. We just define one single bool > property to force the panel into video mode for now. > > Cc: devicetree@xxxxxxxxxxxxxxx > Suggested-by: Rob Herring <robh@xxxxxxxxxx> > Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> > --- > ChangeLog v2->v3: > - Make a more complete DSI panel binding including the controller > and its address-cells and size-cells and a pattern for the panel > nodes. The panel is one per DSI master, the reg property is > compulsory but should always be 0 (as far as I can tell) as > only one panel can be connected. The bus doesn't really have > any addresses for the panel, the address/reg notation seems > to be cargo-culted from the port graphs and is not necessary > to parse some device trees, it is used to tell whether the > node is a panel or not rather than any addressing. > - I have no idea how many displays you can daisychain on a single > DSI master, I just guess 15 will be enough. The MIPI-specs > are memberwalled. Someone who knows can tell perhaps? > ChangeLog v1->v2: > - New patch after feedback. > --- > .../display/panel/panel-dsi-common.yaml | 58 +++++++++++++++++++ > 1 file changed, 58 insertions(+) > create mode 100644 Documentation/devicetree/bindings/display/panel/panel-dsi-common.yaml Perhaps should be display/dsi-controller.yaml now? > > diff --git a/Documentation/devicetree/bindings/display/panel/panel-dsi-common.yaml b/Documentation/devicetree/bindings/display/panel/panel-dsi-common.yaml > new file mode 100644 > index 000000000000..d63f597eff9c > --- /dev/null > +++ b/Documentation/devicetree/bindings/display/panel/panel-dsi-common.yaml > @@ -0,0 +1,58 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/display/panel/panel-dsi-common.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Common Properties for DSI Display Panels > + > +maintainers: > + - Linus Walleij <linus.walleij@xxxxxxxxxx> > + > +description: | > + This document defines device tree properties common to DSI, Display > + Serial Interface panels. It doesn't constitute a device tree binding > + specification by itself but is meant to be referenced by device tree > + bindings. > + > + When referenced from panel device tree bindings the properties defined in > + this document are defined as follows. The panel device tree bindings are > + responsible for defining whether each property is required or optional. > + > + Notice: this binding concerns DSI panels connected directly to a master > + without any intermediate port graph to the panel. Each DSI master > + can control exactly one panel. They should all just have a node "panel" > + for their panel with their reg-property set to 0. > + > +properties: > + $nodename: > + pattern: "^dsi-controller(@[0-9a-f]+)?$" You're assuming a certain unit-address format when a dsi-controller could be on any bus. So use '^dsi-controller(@.*)?$ > + > + "#address-cells": > + const: 1 > + > + "#size-cells": > + const: 0 > + > +patternProperties: > + "^panel$": But here we want to define the unit-address format. The address is the virtual channel # which can be 0-3: ^panel@[0-3]$ > + type: object > + > + properties: > + reg: > + const: 0 minimum: 0 maximum: 3 > + description: > + Only one panel can be connected to each DSI controller, but for I thought it was up to 4 virtual channels? > + historical reasons, the reg property must be specified, as the > + DSI controller can contain other child nodes, and operating > + systems will identify which child node is the panel by looking > + for the reg property. It should however always be set to 0. > + > + enforce-video-mode: > + type: boolean > + description: > + The best option is usually to run a panel in command mode, as this > + gives better control over the panel hardware. However for different > + reasons like broken hardware, missing features or testing, it may be > + useful to be able to force a command mode-capable panel into video > + mode. 'reg' should be required? Rob
