linux-kernel - Re: [PATCH v2 08/10] dt-bindings: connector: Add PCIe M.2 Mechanical Key E connector

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <2fyzwqr5cvkzkkgu5dk6qbc6o2dhnrtt22lf37rv6jzwtmbrek@yhedhlvzpzw7>
Date: Tue, 30 Dec 2025 13:37:56 +0530
From: Manivannan Sadhasivam <mani@...nel.org>
To: Rob Herring <robh@...nel.org>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@....qualcomm.com>, 
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Jiri Slaby <jirislaby@...nel.org>, 
	Nathan Chancellor <nathan@...nel.org>, Nicolas Schier <nicolas.schier@...ux.dev>, 
	Hans de Goede <hansg@...nel.org>, Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>, 
	Mark Pearson <mpearson-lenovo@...ebb.ca>, "Derek J. Clark" <derekjohn.clark@...il.com>, 
	Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, 
	Marcel Holtmann <marcel@...tmann.org>, Luiz Augusto von Dentz <luiz.dentz@...il.com>, 
	Bartosz Golaszewski <brgl@...ev.pl>, linux-serial@...r.kernel.org, linux-kernel@...r.kernel.org, 
	linux-kbuild@...r.kernel.org, platform-driver-x86@...r.kernel.org, linux-pci@...r.kernel.org, 
	devicetree@...r.kernel.org, linux-arm-msm@...r.kernel.org, linux-bluetooth@...r.kernel.org, 
	linux-pm@...r.kernel.org, Stephan Gerhold <stephan.gerhold@...aro.org>, 
	Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
Subject: Re: [PATCH v2 08/10] dt-bindings: connector: Add PCIe M.2 Mechanical
 Key E connector

On Mon, Dec 08, 2025 at 02:28:03PM -0600, Rob Herring wrote:
> On Tue, Nov 25, 2025 at 08:15:12PM +0530, Manivannan Sadhasivam wrote:
> > Add the devicetree binding for PCIe M.2 Mechanical Key E connector defined
> > in the PCI Express M.2 Specification, r4.0, sec 5.1.2. This connector
> > provides interfaces like PCIe or SDIO to attach the WiFi devices to the
> > host machine, USB or UART+PCM interfaces to attach the Bluetooth (BT)
> > devices along with additional interfaces like I2C for NFC solution. At any
> > point of time, the connector can only support either PCIe or SDIO as the
> > WiFi interface and USB or UART as the BT interface.
> 
> AFAICT, there's no muxing of interfaces. Maybe that's a defacto 
> limitation on x86 systems? There's no reason to encode that into the 
> binding if the pins aren't mux'ed on the connector.
> 

Ok. If you prefer not to describe the MUX (if one exists outside of the
connector) in the binding, then having one endpoint sounds reasonable.

You did raise this point in the other series, but the conversation was not
concluded: https://lore.kernel.org/linux-pci/20251119235614.GA3566558-robh@kernel.org/

> > 
> > The connector provides a primary power supply of 3.3v, along with an
> > optional 1.8v VIO supply for the Adapter I/O buffer circuitry operating at
> > 1.8v sideband signaling.
> > 
> > The connector also supplies optional signals in the form of GPIOs for fine
> > grained power management.
> > 
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@....qualcomm.com>
> > ---
> >  .../bindings/connector/pcie-m2-e-connector.yaml    | 178 +++++++++++++++++++++
> >  MAINTAINERS                                        |   1 +
> >  2 files changed, 179 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/connector/pcie-m2-e-connector.yaml b/Documentation/devicetree/bindings/connector/pcie-m2-e-connector.yaml
> > new file mode 100644
> > index 000000000000..fe2c9a943a21
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/connector/pcie-m2-e-connector.yaml
> > @@ -0,0 +1,178 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/connector/pcie-m2-e-connector.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: PCIe M.2 Mechanical Key E Connector
> > +
> > +maintainers:
> > +  - Manivannan Sadhasivam <manivannan.sadhasivam@....qualcomm.com>
> > +
> > +description:
> > +  A PCIe M.2 E connector node represents a physical PCIe M.2 Mechanical Key E
> > +  connector. Mechanical Key E connectors are used to connect Wireless
> > +  Connectivity devices including combinations of Wi-Fi, BT, NFC to the host
> > +  machine over interfaces like PCIe/SDIO, USB/UART+PCM, and I2C.
> > +
> > +properties:
> > +  compatible:
> > +    const: pcie-m2-e-connector
> > +
> > +  vpcie3v3-supply:
> > +    description: A phandle to the regulator for 3.3v supply.
> > +
> > +  vpcie1v8-supply:
> > +    description: A phandle to the regulator for VIO 1.8v supply.
> > +
> > +  ports:
> > +    $ref: /schemas/graph.yaml#/properties/ports
> > +    description: OF graph bindings modeling the interfaces exposed on the
> > +      connector. Since a single connector can have multiple interfaces, every
> > +      interface has an assigned OF graph port number as described below.
> > +
> > +    properties:
> > +      port@0:
> > +        $ref: /schemas/graph.yaml#/properties/port
> > +        description: Connector interfaces for Wi-Fi
> > +
> > +        properties:
> > +          endpoint@0:
> > +            $ref: /schemas/graph.yaml#/properties/endpoint
> > +            description: PCIe interface
> > +
> > +          endpoint@1:
> > +            $ref: /schemas/graph.yaml#/properties/endpoint
> > +            description: SDIO interface
> > +
> > +        anyOf:
> > +          - required:
> > +              - endpoint@0
> > +          - required:
> > +              - endpoint@1
> > +
> > +      port@1:
> > +        $ref: /schemas/graph.yaml#/properties/port
> > +        description: Connector interfaces for BT
> > +
> > +        properties:
> > +          endpoint@0:
> > +            $ref: /schemas/graph.yaml#/properties/endpoint
> > +            description: USB 2.0 interface
> > +
> > +          endpoint@1:
> > +            $ref: /schemas/graph.yaml#/properties/endpoint
> > +            description: UART interface
> > +
> > +        anyOf:
> > +          - required:
> > +              - endpoint@0
> > +          - required:
> > +              - endpoint@1
> > +
> > +      port@2:
> > +        $ref: /schemas/graph.yaml#/properties/port
> > +        description: PCM/I2S interface
> 
> Does this work with any existing DAI bindings? Or conflict with the 
> audio graph card binding?
> 

I haven't verified with any sound card, but it looks to be compatible with the
existing audio graph card binding.

> > +
> > +      port@3:
> > +        $ref: /schemas/graph.yaml#/properties/port
> > +        description: I2C interface
> 
> Like the other one, use i2c-parent.
> 

Ack.

- Mani

-- 
மணிவண்ணன் சதாசிவம்