Per the MII and RMII specifications, for the standard RMII mode,
the REF_CLK is sourced from MAC to PHY or from an external source.
For the standard MII mode, the RX_CLK and TX_CLK are both sourced
by the PHY. But for TJA11xx PHYs, they support reverse mode, that
is, for revRMII mode, the REF_CLK is output, and for revMII mode,
the TX_CLK and RX_CLK are inputs to the PHY.
Previously the "nxp,rmii-refclk-in" was added to indicate that in
RMII mode, if this property present, REF_CLK is input to the PHY,
otherwise it is output. This seems inappropriate now. Firstly, for
the standard RMII mode, REF_CLK is originally input, and there is
no need to add the "nxp,rmii-refclk-in" property to indicate that
REF_CLK is input. Secondly, this property is not generic for TJA
PHYs, because it cannot cover the settings of TX_CLK and RX_CLK in
MII mode. Therefore, add new property "nxp,reverse-mode" to instead
of the "nxp,rmii-refclk-in" property.
Signed-off-by: Wei Fang <wei.fang@xxxxxxx>
---
.../devicetree/bindings/net/nxp,tja11xx.yaml | 21 +++++++------------
1 file changed, 7 insertions(+), 14 deletions(-)
diff --git a/Documentation/devicetree/bindings/net/nxp,tja11xx.yaml b/Documentation/devicetree/bindings/net/nxp,tja11xx.yaml
index 85bfa45f5122..e8ab2cf8d4d4 100644
--- a/Documentation/devicetree/bindings/net/nxp,tja11xx.yaml
+++ b/Documentation/devicetree/bindings/net/nxp,tja11xx.yaml
@@ -32,21 +32,14 @@ patternProperties:
description:
The ID number for the child PHY. Should be +1 of parent PHY.
- nxp,rmii-refclk-in:
+ nxp,reverse-mode:
type: boolean
description: |
- The REF_CLK is provided for both transmitted and received data
- in RMII mode. This clock signal is provided by the PHY and is
- typically derived from an external 25MHz crystal. Alternatively,
- a 50MHz clock signal generated by an external oscillator can be
- connected to pin REF_CLK. A third option is to connect a 25MHz
- clock to pin CLK_IN_OUT. So, the REF_CLK should be configured
- as input or output according to the actual circuit connection.
- If present, indicates that the REF_CLK will be configured as
- interface reference clock input when RMII mode enabled.
- If not present, the REF_CLK will be configured as interface
- reference clock output when RMII mode enabled.
- Only supported on TJA1100 and TJA1101.
+ If present, the TJA11xx PHY will operate in "reversed" role mode.
+ If XMII_MODE is set to MII, the device operates in revMII mode
+ (TXCLK and RXCLK are input).
+ If XMII_MODE is set to RMII, the device operates in revRMII mode
+ (REF_CLK is output).
required:
- reg
@@ -61,7 +54,7 @@ examples:
tja1101_phy0: ethernet-phy@4 {
reg = <0x4>;
- nxp,rmii-refclk-in;
+ nxp,reverse-mode;
};
};
- |
--
2.34.1
