RE: [v2 1/2] Docs/devicetree: add serdes-output-amplitude-mv to marvell.txt

On Thu,  2 Dec 2021 09:05:26 +0100
Holger Brunck [off-list ref] wrote:

quoted

This can be configured from the device tree. Add this property to the
documentation accordingly. This is a property of the port node, which
needs to be specified in millivolts

CC: Andrew Lunn <andrew@lunn.ch>
CC: Jakub Kicinski <kuba@kernel.org>
CC: Marek Behún <kabel@kernel.org>
Signed-off-by: Holger Brunck <redacted>
---
 Documentation/devicetree/bindings/net/dsa/marvell.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/dsa/marvell.txt

b/Documentation/devicetree/bindings/net/dsa/marvell.txt
index 2363b412410c..9292b6f960df 100644

--- a/Documentation/devicetree/bindings/net/dsa/marvell.txt
+++ b/Documentation/devicetree/bindings/net/dsa/marvell.txt

@@ -46,6 +46,11 @@ Optional properties:
 - mdio?              : Container of PHYs and devices on the external MDIO
                        bus. The node must contains a compatible string of
                        "marvell,mv88e6xxx-mdio-external"
+- serdes-output-amplitude-mv: Configure the output amplitude of the serdes
+                           interface in millivolts. This option can be
+                              set in the ports node as it is a property of
+                              the port.
+    serdes-output-amplitude-mv = <210>;

The suffix should be millivolt, as can be seen in other bindings.

Also I think maybe use "tx" instead of "output"? It is more common to refere to
serdes pairs as rx/tx instead of input/output:

  serdes-tx-amplitude-millivolt

I can change that. The naming output-amplitude was chosen because the
register in the datasheet is named  "SGMII/FiberOutput Amplitude".
If I change it,  it would make sense that I also rename the
function and variable names to make it consistent IMHO.

Best regards
Holger