| Message ID | 20240704140413.2797199-4-kamilh@axis.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: phy: bcm5481x: add support for BroadR-Reach mode | expand |
On Thu, Jul 04, 2024 at 04:04:12PM +0200, Kamil Horák (2N) wrote: > There is a group of PHY chips supporting BroadR-Reach link modes in > a manner allowing for more or less identical register usage as standard > Clause 22 PHY. > These chips support standard Ethernet link modes as well, however, the > circuitry is mutually exclusive and cannot be auto-detected. > The link modes in question are 100Base-T1 as defined in IEEE802.3bw, > based on Broadcom's 1BR-100 link mode, and newly defined 10Base-T1BRR > (1BR-10 in Broadcom documents). > > Add optional brr-mode flag to switch the PHY to BroadR-Reach mode. > > Signed-off-by: Kamil Horák (2N) <kamilh@axis.com> Where did the tags go? There's no mention of why they were dropped. > --- > Documentation/devicetree/bindings/net/ethernet-phy.yaml | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/Documentation/devicetree/bindings/net/ethernet-phy.yaml b/Documentation/devicetree/bindings/net/ethernet-phy.yaml > index 8fb2a6ee7e5b..349ae72ebf42 100644 > --- a/Documentation/devicetree/bindings/net/ethernet-phy.yaml > +++ b/Documentation/devicetree/bindings/net/ethernet-phy.yaml > @@ -93,6 +93,14 @@ properties: > the turn around line low at end of the control phase of the > MDIO transaction. > > + brr-mode: > + $ref: /schemas/types.yaml#/definitions/flag > + description: > + If set, indicates the network cable interface is alternative one as > + defined in the BroadR-Reach link mode specification under 1BR-100 and > + 1BR-10 names. The driver needs to configure the PHY to operate in > + BroadR-Reach mode. I find this second sentence unclear. Does the driver need to do configure the phy because this mode is not enabled by default or because the device will not work outside of this mode. Cheers, Conor.
> > --- > > Documentation/devicetree/bindings/net/ethernet-phy.yaml | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/net/ethernet-phy.yaml b/Documentation/devicetree/bindings/net/ethernet-phy.yaml > > index 8fb2a6ee7e5b..349ae72ebf42 100644 > > --- a/Documentation/devicetree/bindings/net/ethernet-phy.yaml > > +++ b/Documentation/devicetree/bindings/net/ethernet-phy.yaml > > @@ -93,6 +93,14 @@ properties: > > the turn around line low at end of the control phase of the > > MDIO transaction. > > > > + brr-mode: > > + $ref: /schemas/types.yaml#/definitions/flag > > + description: > > + If set, indicates the network cable interface is alternative one as > > + defined in the BroadR-Reach link mode specification under 1BR-100 and > > + 1BR-10 names. The driver needs to configure the PHY to operate in > > + BroadR-Reach mode. > > I find this second sentence unclear. Does the driver need to do > configure the phy because this mode is not enabled by default or because > the device will not work outside of this mode. BroadR-Reach uses one pair. Standard 10/100Mbps ethernet needs 2 pair, and 1G needs 4 pair. So any attempt to use standard 10/100/1G is going to fail, the socket/plug and cable just don't work for anything other than BroadR-Reach. As far as i understand it, the PHY could be strapped into BroadR-Reach mode, but there is no guarantee it is, so we should also program it to BroadR-Reach mode if this property is present. Andrew
On Thu, Jul 04, 2024 at 11:11:41PM +0200, Andrew Lunn wrote: > > > --- > > > Documentation/devicetree/bindings/net/ethernet-phy.yaml | 8 ++++++++ > > > 1 file changed, 8 insertions(+) > > > > > > diff --git a/Documentation/devicetree/bindings/net/ethernet-phy.yaml b/Documentation/devicetree/bindings/net/ethernet-phy.yaml > > > index 8fb2a6ee7e5b..349ae72ebf42 100644 > > > --- a/Documentation/devicetree/bindings/net/ethernet-phy.yaml > > > +++ b/Documentation/devicetree/bindings/net/ethernet-phy.yaml > > > @@ -93,6 +93,14 @@ properties: > > > the turn around line low at end of the control phase of the > > > MDIO transaction. > > > > > > + brr-mode: > > > + $ref: /schemas/types.yaml#/definitions/flag > > > + description: > > > + If set, indicates the network cable interface is alternative one as nit: an alternative > > > + defined in the BroadR-Reach link mode specification under 1BR-100 and > > > + 1BR-10 names. The driver needs to configure the PHY to operate in > > > + BroadR-Reach mode. > > > > I find this second sentence unclear. Does the driver need to do > > configure the phy because this mode is not enabled by default or because > > the device will not work outside of this mode. > > BroadR-Reach uses one pair. Standard 10/100Mbps ethernet needs 2 pair, > and 1G needs 4 pair. So any attempt to use standard 10/100/1G is going > to fail, the socket/plug and cable just don't work for anything other > than BroadR-Reach. > > As far as i understand it, the PHY could be strapped into BroadR-Reach > mode, but there is no guarantee it is, so we should also program it to > BroadR-Reach mode if this property is present. Right, I guess for people that want brr-mode they'll probably understand that and it's just unclear to me as I don't :) The nitpicking side of my brain would like that last sentence reworded to "The PHY must be configured to operate in BroadR-Reach mode by software", mostly cos the word "driver" assumes a particular model for the OS, but it's not really a big deal. Acked-by: Conor Dooley <conor.dooley@microchip.com>
diff --git a/Documentation/devicetree/bindings/net/ethernet-phy.yaml b/Documentation/devicetree/bindings/net/ethernet-phy.yaml index 8fb2a6ee7e5b..349ae72ebf42 100644 --- a/Documentation/devicetree/bindings/net/ethernet-phy.yaml +++ b/Documentation/devicetree/bindings/net/ethernet-phy.yaml @@ -93,6 +93,14 @@ properties: the turn around line low at end of the control phase of the MDIO transaction. + brr-mode: + $ref: /schemas/types.yaml#/definitions/flag + description: + If set, indicates the network cable interface is alternative one as + defined in the BroadR-Reach link mode specification under 1BR-100 and + 1BR-10 names. The driver needs to configure the PHY to operate in + BroadR-Reach mode. + clocks: maxItems: 1 description:
There is a group of PHY chips supporting BroadR-Reach link modes in a manner allowing for more or less identical register usage as standard Clause 22 PHY. These chips support standard Ethernet link modes as well, however, the circuitry is mutually exclusive and cannot be auto-detected. The link modes in question are 100Base-T1 as defined in IEEE802.3bw, based on Broadcom's 1BR-100 link mode, and newly defined 10Base-T1BRR (1BR-10 in Broadcom documents). Add optional brr-mode flag to switch the PHY to BroadR-Reach mode. Signed-off-by: Kamil Horák (2N) <kamilh@axis.com> --- Documentation/devicetree/bindings/net/ethernet-phy.yaml | 8 ++++++++ 1 file changed, 8 insertions(+)