linux-kernel - Re: [PATCH v4 1/3] dt-bindings: PCI: dwc: Add one more reference clock

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] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250627-sensible-pigeon-of-reading-b021a3@krzk-bin>
Date: Fri, 27 Jun 2025 08:54:46 +0200
From: Krzysztof Kozlowski <krzk@...nel.org>
To: Richard Zhu <hongxing.zhu@....com>
Cc: frank.li@....com, l.stach@...gutronix.de, lpieralisi@...nel.org, 
	kwilczynski@...nel.org, mani@...nel.org, robh@...nel.org, krzk+dt@...nel.org, 
	conor+dt@...nel.org, bhelgaas@...gle.com, shawnguo@...nel.org, s.hauer@...gutronix.de, 
	kernel@...gutronix.de, festevam@...il.com, linux-pci@...r.kernel.org, 
	linux-arm-kernel@...ts.infradead.org, devicetree@...r.kernel.org, imx@...ts.linux.dev, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 1/3] dt-bindings: PCI: dwc: Add one more reference
 clock

On Thu, Jun 26, 2025 at 03:38:02PM +0800, Richard Zhu wrote:
> Add one more reference clock "extref" to be onhalf the reference clock
> that comes from external crystal oscillator.
> 
> Signed-off-by: Richard Zhu <hongxing.zhu@....com>
> ---
>  .../devicetree/bindings/pci/snps,dw-pcie-common.yaml        | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/pci/snps,dw-pcie-common.yaml b/Documentation/devicetree/bindings/pci/snps,dw-pcie-common.yaml
> index 34594972d8db..ee09e0d3bbab 100644
> --- a/Documentation/devicetree/bindings/pci/snps,dw-pcie-common.yaml
> +++ b/Documentation/devicetree/bindings/pci/snps,dw-pcie-common.yaml
> @@ -105,6 +105,12 @@ properties:
>              define it with this name (for instance pipe, core and aux can
>              be connected to a single source of the periodic signal).
>            const: ref
> +        - description:
> +            Some dwc wrappers (like i.MX95 PCIes) have two reference clock
> +            inputs, one from internal PLL, the other from off chip crystal
> +            oscillator. Use extref clock name to be onhalf of the reference
> +            clock comes form external crystal oscillator.

How internal PLL can be represented as 'ref' clock? Internal means it is
not outside, so impossible to represent.

Where is the DTS so we can look at big picture?


Best regards,
Krzysztof