[U-Boot] [PATCH v5 6/7] phy: Add USB PHY driver for the cadence USB3

[Pawel Laszczak]

+ Rafal, Anil, Sanket, Jayshri, Rahul

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>We are discussing if Cadence/TI/NXP could use the same USB PHY driver
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>(drivers/phy/cadence/phy-cadence-sierra.c), I find I can't get
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>Alan Douglas <adouglas at cadence.com>, would you please forward related
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>people? The question is like below, thanks.
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>Alan, we find the suggested value at this driver (drivers/phy/cadence/phy-cadence-sierra.c)
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>is so different with "USB 3.0 PHY User Guide for 28FDSOI" CH 3.1.1 Bring-up Sequence.
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>Does this driver support this 28nm PHY? If it supports, why the initialized value is so different?
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>The UG suggested value can be used at NXP platform.
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>Peter
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>> > >
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>> > > This is indeed a different driver. IMO it would be better to keep
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>> > > the driver closer to its linux version. The reason for that  is that
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>> > > it is quite new and will be adapted when platforms starts supporting
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>> > > it. If we start with something too far from the original, it will hard to update.
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>> > > Already I see that the registers initialized are not all the same as
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>> > > in the linux driver and not all the values are the same either, nor
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>> > > are the register names
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>> > >
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>> > > TI's J7 platforms is using this PHY driver for USB3/PCIe support,
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>> > > and the linux driver has already seen quite a few modifications to
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>> > > get it to work
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>> > (https://urldefense.proofpoint.com/v2/url?u=https-3A__eur01.safelinks.protection.outlook.com_-3Furl-3Dhttps-253A-252F-
>252Fgit.ti&d=DwIGaQ&c=aUq983L2pue2FqKFoP6PGHMJQyoJ7kl3s3GZ-_haXqY&r=e1OgxfvkL0qo9XO6fX1gscva-w03uSYC1nIyxl89-
>rI&m=Ip2RbyxoGLS3zuYNjazxkPFURIUZllrs6iSfUmllZGM&s=MG2JpCkGii7tKv3Sb4ekJ08smJd54TTIC6jmZpOdzY0&e= .
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>> > > com%2Fti-linux-kernel%2Fti-linux-kernel%2Fblobs%2Fhistory%2Fti-linux
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>> > > -
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>> > > 4.19.y%2Fdrivers%2Fphy%2Fcadence%2Fphy-cadence-
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>> > > sierra.c&data=02%7C01%7Csherry.sun%40nxp.com%7C84f9122d7eb64
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>> > > 9820bae08d72b997681%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0
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>> > > %7C637025810458595586&sdata=6JpD7VcFudhzXSVP0WaGVEp7Fwrue
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>> > > A%2B4V6eeOfif19w%3D&reserved=0)
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>> > > Adding support for it on top of this current version will be rather difficult.
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>> > >
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>> >
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>> > Thanks for your advice.
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>> > Actually I am not familiar with this phy driver in linux, so also
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>> > +peter, who worked on this USB driver under linux, maybe he can give some
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>> suggestions.
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>> >
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>>
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>> Add Alan from Cadence
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>>
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>> Alan, we find the suggested value at this driver (drivers/phy/cadence/phy-cadence-
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>> sierra.c)
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>> is so different with "USB 3.0 PHY User Guide for 28FDSOI" CH 3.1.1 Bring-up
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>> Sequence.
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>> Does this driver support this 28nm PHY? If it supports, why the initialized value is so
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>> different?
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>> The UG suggested value can be used at NXP platform.
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>>
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>> Peter