Re: [PATCH devicetree v3] dt-bindings: phy: Add `tx-p2p-microvolt` property binding

From: Vinod Koul <vkoul@kernel.org>
To: "Marek Behún" <kabel@kernel.org>
Cc: Rob Herring <robh@kernel.org>,
	Florian Fainelli <f.fainelli@gmail.com>,
	devicetree@vger.kernel.org, Vladimir Oltean <olteanv@gmail.com>,
	Holger Brunck <holger.brunck@hitachienergy.com>,
	Andrew Lunn <andrew@lunn.ch>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	Russell King <rmk+kernel@armlinux.org.uk>,
	linux-phy@lists.infradead.org,
	Kishon Vijay Abraham I <kishon@ti.com>
Subject: Re: [PATCH devicetree v3] dt-bindings: phy: Add `tx-p2p-microvolt` property binding
Date: Mon, 7 Feb 2022 10:59:38 +0530	[thread overview]
Message-ID: <YgCuQjN5tBvljrQN@matsya> (raw)
In-Reply-To: <20220206185413.4c1ac00d@thinkpad>

On 06-02-22, 18:54, Marek Behún wrote:
> On Fri, 4 Feb 2022 20:18:40 -0600
> Rob Herring <robh@kernel.org> wrote:
> 
> > On Fri, Jan 21, 2022 at 11:18:09AM -0800, Florian Fainelli wrote:
> > > On 1/19/22 5:11 AM, Marek Behún wrote:  
> > > > Common PHYs and network PCSes often have the possibility to specify
> > > > peak-to-peak voltage on the differential pair - the default voltage
> > > > sometimes needs to be changed for a particular board.
> > > > 
> > > > Add properties `tx-p2p-microvolt` and `tx-p2p-microvolt-names` for this
> > > > purpose. The second property is needed to specify the mode for the
> > > > corresponding voltage in the `tx-p2p-microvolt` property, if the voltage
> > > > is to be used only for speficic mode. More voltage-mode pairs can be
> > > > specified.
> > > > 
> > > > Example usage with only one voltage (it will be used for all supported
> > > > PHY modes, the `tx-p2p-microvolt-names` property is not needed in this
> > > > case):
> > > > 
> > > >   tx-p2p-microvolt = <915000>;
> > > > 
> > > > Example usage with voltages for multiple modes:
> > > > 
> > > >   tx-p2p-microvolt = <915000>, <1100000>, <1200000>;
> > > >   tx-p2p-microvolt-names = "2500base-x", "usb", "pcie";
> > > > 
> > > > Add these properties into a separate file phy/transmit-amplitude.yaml,
> > > > which should be referenced by any binding that uses it.  
> > > 
> > > p2p commonly means peer to peer which incidentally could be confusing,
> > > can you spell out the property entire:
> > > 
> > > tx-peaktopeak-microvolt or:
> > > 
> > > tx-pk2pk-microvolt for a more compact name maybe?  
> > 
> > Peer to peer makes little sense in terms of a voltage. I think this is 
> > fine as-is.
> 
> Cool. Should this get merged via devicetree, or via phy maintainers?
> Or should I resend this together with patches that make use of this
> property? (In that case can you add your Ack?)

Sending with patches using this would be better.. It can go thru phy
tree

-- 
~Vinod

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