Hi Rob, > -----Original Message----- > From: Rob Herring <robh@xxxxxxxxxx> > Sent: Saturday, August 21, 2021 4:02 AM > To: ChiaWei Wang <chiawei_wang@xxxxxxxxxxxxxx> > Cc: joel@xxxxxxxxx; andrew@xxxxxxxx; linux-aspeed@xxxxxxxxxxxxxxxx; > openbmc@xxxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Ryan Chen > <ryan_chen@xxxxxxxxxxxxxx> > Subject: Re: [PATCH v2 1/5] dt-bindings: aspeed: Add eSPI controller > > On Thu, Aug 19, 2021 at 04:00:36PM +0800, Chia-Wei Wang wrote: > > Add dt-bindings for Aspeed eSPI controller > > > > Signed-off-by: Chia-Wei Wang <chiawei_wang@xxxxxxxxxxxxxx> > > --- > > .../devicetree/bindings/soc/aspeed/espi.yaml | 158 > > ++++++++++++++++++ > > 1 file changed, 158 insertions(+) > > create mode 100644 > > Documentation/devicetree/bindings/soc/aspeed/espi.yaml > > > > diff --git a/Documentation/devicetree/bindings/soc/aspeed/espi.yaml > > b/Documentation/devicetree/bindings/soc/aspeed/espi.yaml > > new file mode 100644 > > index 000000000000..fec3d37f3ffd > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/soc/aspeed/espi.yaml > > @@ -0,0 +1,158 @@ > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) # # > > +Copyright (c) 2021 Aspeed Technology Inc. > > +%YAML 1.2 > > +--- > > +$id: "http://devicetree.org/schemas/soc/aspeed/espi.yaml#"; > > +$schema: "http://devicetree.org/meta-schemas/core.yaml#"; > > + > > +title: Aspeed eSPI Controller > > + > > +maintainers: > > + - Chia-Wei Wang <chiawei_wang@xxxxxxxxxxxxxx> > > + - Ryan Chen <ryan_chen@xxxxxxxxxxxxxx> > > + > > +description: > > + Aspeed eSPI controller implements a slave side eSPI endpoint device > > + supporting the four eSPI channels, namely peripheral, virtual wire, > > + out-of-band, and flash. > > + > > +properties: > > + compatible: > > + items: > > + - enum: > > + - aspeed,ast2500-espi > > + - aspeed,ast2600-espi > > + - const: simple-mfd > > + - const: syscon > > Is this really 2 sub devices that could be used individually or in a different > combination? If not, then I'd make all this 1 node. espi-mmbi has individual function and control registers. However, espi-mmbi is also a feature extended based on the memory cycle of eSPI peripheral channel. Thereby, it has dependency on the eSPI channel initialization conducted by espi-ctrl. The scenario is similar to the lpc-ctrl and other lpc-xxx drivers of Aspeed SoCs. Chiawei
