| Message ID | 20211117225050.18395-2-kabel@kernel.org |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | Extend `phy-mode` to string array | expand |
| Context | Check | Description |
|---|---|---|
| robh/checkpatch | success | |
| robh/dt-meta-schema | success | |
| robh/dtbs-check | fail | build log |
On Wed, Nov 17, 2021 at 11:50:43PM +0100, Marek Behún wrote: > Sometimes, an ethernet PHY may communicate with ethernet controller with > multiple different PHY connection types, and the software should be able > to choose between them. > > Russell King says: > conventionally phy-mode has meant "this is the mode we want to operate > the PHY interface in" which was fine when PHYs didn't change their > mode depending on the media speed > This is no longer the case, since we have PHYs that can change PHY mode. > > Existing example is the Marvell 88X3310 PHY, which supports connecting > the MAC with the PHY with `xaui` and `rxaui`. The MAC may also support > both modes, but it is possible that a particular board doesn't have > these modes wired (since they use multiple SerDes lanes). > > Another example is one SerDes lane capable of `1000base-x`, `2500base-x` > and `sgmii` when connecting Marvell switches with Marvell ethernet > controller. Currently we mention only one of these modes in device-tree, > and software assumes the other modes are also supported, since they use > the same SerDes lanes. But a board may be able to support `1000base-x` > and not support `2500base-x`, for example due to the higher frequency > not working correctly on a particular board. > > In order for the kernel to know which modes are supported on the board, > we need to be able to specify them all in the device-tree. > > Change the type of property `phy-connection-type` of an ethernet > controller to be an array of the enumerated strings, instead of just one > string. Require at least one item defined. > > Signed-off-by: Marek Behún <kabel@kernel.org> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Andrew
diff --git a/Documentation/devicetree/bindings/net/ethernet-controller.yaml b/Documentation/devicetree/bindings/net/ethernet-controller.yaml index b0933a8c295a..1fd27d45d136 100644 --- a/Documentation/devicetree/bindings/net/ethernet-controller.yaml +++ b/Documentation/devicetree/bindings/net/ethernet-controller.yaml @@ -54,51 +54,55 @@ properties: phy-connection-type: description: - Specifies interface type between the Ethernet device and a physical - layer (PHY) device. - enum: - # There is not a standard bus between the MAC and the PHY, - # something proprietary is being used to embed the PHY in the - # MAC. - - internal - - mii - - gmii - - sgmii - - qsgmii - - tbi - - rev-mii - - rmii - - rev-rmii - - # RX and TX delays are added by the MAC when required - - rgmii - - # RGMII with internal RX and TX delays provided by the PHY, - # the MAC should not add the RX or TX delays in this case - - rgmii-id - - # RGMII with internal RX delay provided by the PHY, the MAC - # should not add an RX delay in this case - - rgmii-rxid - - # RGMII with internal TX delay provided by the PHY, the MAC - # should not add an TX delay in this case - - rgmii-txid - - rtbi - - smii - - xgmii - - trgmii - - 1000base-x - - 2500base-x - - 5gbase-r - - rxaui - - xaui - - # 10GBASE-KR, XFI, SFI - - 10gbase-kr - - usxgmii - - 10gbase-r - - 25gbase-r + Specifies interface types between the Ethernet device and a physical + layer (PHY) device. Since more interface types can be wired between + the MAC and the PHY, this property should list all that are supported + by the board. + minItems: 1 + items: + enum: + # There is not a standard bus between the MAC and the PHY, + # something proprietary is being used to embed the PHY in the + # MAC. + - internal + - mii + - gmii + - sgmii + - qsgmii + - tbi + - rev-mii + - rmii + - rev-rmii + + # RX and TX delays are added by the MAC when required + - rgmii + + # RGMII with internal RX and TX delays provided by the PHY, + # the MAC should not add the RX or TX delays in this case + - rgmii-id + + # RGMII with internal RX delay provided by the PHY, the MAC + # should not add an RX delay in this case + - rgmii-rxid + + # RGMII with internal TX delay provided by the PHY, the MAC + # should not add an TX delay in this case + - rgmii-txid + - rtbi + - smii + - xgmii + - trgmii + - 1000base-x + - 2500base-x + - 5gbase-r + - rxaui + - xaui + + # 10GBASE-KR, XFI, SFI + - 10gbase-kr + - usxgmii + - 10gbase-r + - 25gbase-r phy-mode: $ref: "#/properties/phy-connection-type"
Sometimes, an ethernet PHY may communicate with ethernet controller with multiple different PHY connection types, and the software should be able to choose between them. Russell King says: conventionally phy-mode has meant "this is the mode we want to operate the PHY interface in" which was fine when PHYs didn't change their mode depending on the media speed This is no longer the case, since we have PHYs that can change PHY mode. Existing example is the Marvell 88X3310 PHY, which supports connecting the MAC with the PHY with `xaui` and `rxaui`. The MAC may also support both modes, but it is possible that a particular board doesn't have these modes wired (since they use multiple SerDes lanes). Another example is one SerDes lane capable of `1000base-x`, `2500base-x` and `sgmii` when connecting Marvell switches with Marvell ethernet controller. Currently we mention only one of these modes in device-tree, and software assumes the other modes are also supported, since they use the same SerDes lanes. But a board may be able to support `1000base-x` and not support `2500base-x`, for example due to the higher frequency not working correctly on a particular board. In order for the kernel to know which modes are supported on the board, we need to be able to specify them all in the device-tree. Change the type of property `phy-connection-type` of an ethernet controller to be an array of the enumerated strings, instead of just one string. Require at least one item defined. Signed-off-by: Marek Behún <kabel@kernel.org> Cc: devicetree@vger.kernel.org --- Changes since RFC: - update also description of the `phy-connection-type` property --- .../bindings/net/ethernet-controller.yaml | 94 ++++++++++--------- 1 file changed, 49 insertions(+), 45 deletions(-)