Re: [PATCH v2 1/4] dt-bindings: clock: qcom: Add CMN PLL clock controller for IPQ SoC

[Jie Luo]

On 8/21/2024 4:33 PM, Krzysztof Kozlowski wrote:
> On Tue, Aug 20, 2024 at 10:02:42PM +0800, Luo Jie wrote:
> > The CMN PLL controller provides clocks to networking hardware blocks
> > on Qualcomm IPQ9574 SoC. It receives input clock from the on-chip Wi-Fi,
> > and produces output clocks at fixed rates. These output rates are
> > predetermined, and are unrelated to the input clock rate. The output
> > clocks are supplied to the Ethernet hardware such as PPE (packet
> > process engine) and the externally connected switch or PHY device.
> >
> > Signed-off-by: Luo Jie <quic_luoj@xxxxxxxxxxx>
> > ---
> >   .../bindings/clock/qcom,ipq9574-cmn-pll.yaml       | 70 ++++++++++++++++++++++
> >   include/dt-bindings/clock/qcom,ipq-cmn-pll.h       | 15 +++++
> >   2 files changed, 85 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/clock/qcom,ipq9574-cmn-pll.yaml b/Documentation/devicetree/bindings/clock/qcom,ipq9574-cmn-pll.yaml
> > new file mode 100644
> > index 000000000000..7ad04b58a698
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/clock/qcom,ipq9574-cmn-pll.yaml
> > @@ -0,0 +1,70 @@
> > +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/clock/qcom,ipq9574-cmn-pll.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Qualcomm CMN PLL Clock Controller on IPQ SoC
> > +
> > +maintainers:
> > +  - Bjorn Andersson <andersson@xxxxxxxxxx>
> > +  - Luo Jie <quic_luoj@xxxxxxxxxxx>
> > +
> > +description:
> > +  The CMN PLL clock controller expects a reference input clock.
>
> You did not explain what is CMN. Is this some sort of acronym?

CMN is short form for 'common'. Since it is referred to as 'CMN'
PLL in the hardware programming guides, we wanted the driver name
to include it as well. The description can be updated as below to
clarify the name and purpose of this hardware block. Hope this is
fine.

"The CMN PLL clock controller expects a reference input clock
from the on-board Wi-Fi, and supplies a number of fixed rate
output clocks to the Ethernet devices including PPE (packet
process engine) and the connected switch or PHY device. The
CMN (or 'common') PLL's only function is to enable clocks to
Ethernet hardware used with the IPQ SoC and does not include
any other function."

> Best regards,
> Krzysztof