dt-bindings: net: ipq4019-mdio: document now supported clock-frequency

Document support for clock-frequency and add details on why this
property is needed and what values are supported.

From internal documentation, while other values are supported, the
correct function of the MDIO bus is not assured hence add only the
suggested supported values to the property enum.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Christian Marangi 2024-01-31 03:26:03 +01:00 committed by David S. Miller
parent 747056a9a9
commit 9484b9555d

View File

@ -44,6 +44,21 @@ properties:
items:
- const: gcc_mdio_ahb_clk
clock-frequency:
description:
The MDIO bus clock that must be output by the MDIO bus hardware, if
absent, the default hardware values are used.
MDC rate is feed by an external clock (fixed 100MHz) and is divider
internally. The default divider is /256 resulting in the default rate
applied of 390KHz.
To follow 802.3 standard that instruct up to 2.5MHz by default, if
this property is not declared and the divider is set to /256, by
default 1.5625Mhz is select.
enum: [ 390625, 781250, 1562500, 3125000, 6250000, 12500000 ]
default: 1562500
required:
- compatible
- reg