Re: [PATCH net-next v6 1/4] net: phy: add USXGMII link partner ability constants

Michael Walle
2020-07-16T07:49:30Z

Am 2020-07-16 00:44, schrieb Vladimir Oltean:
> On Wed, Jul 15, 2020 at 10:33:23PM +0200, Michael Walle wrote:
>> Am 2020-07-13 20:37, schrieb Michael Walle:
>> > Am 2020-07-13 20:23, schrieb Russell King - ARM Linux admin:
>> > > On Thu, Jul 09, 2020 at 11:35:23PM +0200, Michael Walle wrote:
>> > > > The constants are taken from the USXGMII Singleport Copper Interface
>> > > > specification. The naming are based on the SGMII ones, but with
>> > > > an MDIO_
>> > > > prefix.
>> > > >
>> > > > Signed-off-by: Michael Walle <michael@walle.cc>
>> > > > ---
>> > > > include/uapi/linux/mdio.h | 26 ++++++++++++++++++++++++++
>> > > > 1 file changed, 26 insertions(+)
>> > > >
>> > > > diff --git a/include/uapi/linux/mdio.h b/include/uapi/linux/mdio.h
>> > > > index 4bcb41c71b8c..784723072578 100644
>> > > > --- a/include/uapi/linux/mdio.h
>> > > > +++ b/include/uapi/linux/mdio.h
>> > > > @@ -324,4 +324,30 @@ static inline __u16 mdio_phy_id_c45(int
>> > > > prtad, int devad)
>> > > > return MDIO_PHY_ID_C45 | (prtad << 5) | devad;
>> > > > }
>> > > >
>> > > > +/* UsxgmiiChannelInfo[15:0] for USXGMII in-band auto-negotiation.*/
>> > > > +#define MDIO_LPA_USXGMII_EEE_CLK_STP 0x0080 /* EEE clock stop
>> > > > supported */
>> > > > +#define MDIO_LPA_USXGMII_EEE 0x0100 /* EEE supported */
>> > > > +#define MDIO_LPA_USXGMII_SPD_MASK 0x0e00 /* USXGMII speed mask */
>> > > > +#define MDIO_LPA_USXGMII_FULL_DUPLEX 0x1000 /* USXGMII full
>> > > > duplex */
>> > > > +#define MDIO_LPA_USXGMII_DPX_SPD_MASK 0x1e00 /* USXGMII duplex
>> > > > and speed bits */
>> > > > +#define MDIO_LPA_USXGMII_10 0x0000 /* 10Mbps */
>> > > > +#define MDIO_LPA_USXGMII_10HALF 0x0000 /* 10Mbps half-duplex */
>> > > > +#define MDIO_LPA_USXGMII_10FULL 0x1000 /* 10Mbps full-duplex */
>> > > > +#define MDIO_LPA_USXGMII_100 0x0200 /* 100Mbps */
>> > > > +#define MDIO_LPA_USXGMII_100HALF 0x0200 /* 100Mbps half-duplex */
>> > > > +#define MDIO_LPA_USXGMII_100FULL 0x1200 /* 100Mbps full-duplex */
>> > > > +#define MDIO_LPA_USXGMII_1000 0x0400 /* 1000Mbps */
>> > > > +#define MDIO_LPA_USXGMII_1000HALF 0x0400 /* 1000Mbps half-duplex */
>> > > > +#define MDIO_LPA_USXGMII_1000FULL 0x1400 /* 1000Mbps full-duplex */
>> > > > +#define MDIO_LPA_USXGMII_10G 0x0600 /* 10Gbps */
>> > > > +#define MDIO_LPA_USXGMII_10GHALF 0x0600 /* 10Gbps half-duplex */
>> > > > +#define MDIO_LPA_USXGMII_10GFULL 0x1600 /* 10Gbps full-duplex */
>> > > > +#define MDIO_LPA_USXGMII_2500 0x0800 /* 2500Mbps */
>> > > > +#define MDIO_LPA_USXGMII_2500HALF 0x0800 /* 2500Mbps half-duplex */
>> > > > +#define MDIO_LPA_USXGMII_2500FULL 0x1800 /* 2500Mbps full-duplex */
>> > > > +#define MDIO_LPA_USXGMII_5000 0x0a00 /* 5000Mbps */
>> > > > +#define MDIO_LPA_USXGMII_5000HALF 0x0a00 /* 5000Mbps half-duplex */
>> > > > +#define MDIO_LPA_USXGMII_5000FULL 0x1a00 /* 5000Mbps full-duplex */
>> > > > +#define MDIO_LPA_USXGMII_LINK 0x8000 /* PHY link with
>> > > > copper-side partner */
>> > >
>> > > btw, the only thing which is missing from this is bit 0.
>> >
>> > TBH, I didn't know how to name it. Any suggestions?
>>
>> NXP calls it ABIL0, in xilinx docs its called USXGMII [1]. In the
>> USXGMII
>> spec, its "set to 1 (0 is SGMII)" which I don't understand because its
>> also 1 for SGMII, right? At least as described in the
>> tx_configReg[15:0] in
>> the SGMII spec.
>>
>> #define MDIO_USXGMII_USXGMII 0x0001 ?
>>
>> -michael
>>
>> [1]
>> https://www.xilinx.com/support/documentation/ip_documentation/usxgmii/v1_0/pg251-usxgmii.pdf
>
> The explanation in the spec is quite cryptic, I've taken that to mean
> "corresponds to bit 0 in SGMII". Hence the reason why, in the code I've
> introduced in Felix, this is simply used as ADVERTISE_SGMII. I have no
> problem in creating an alias to ADVERTISE_SGMII named
> MDIO_LPA_USXGMII_SGMII. That being said, I don't see, right now, a
> practical situation where you might want to parse bit 0 from LPA, it's
> just like in Forrest Gump: "life is like a box of chocolates, you never
> know what you're gonna get". Adding it now to the UAPI might very well
> be a non-issue.

what about
#define MDIO_USXGMII_ADVERTISE 0x0001 /* must always be set */

Russell, do you agree? Then I'd send a new version with your
"Reviewed-by:".

-michael