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From:   George McCollister <george.mccollister@gmail.com>
Date:   Mon, 9 Sep 2019 08:33:05 -0500
Message-ID: <CAFSKS=PMBQyAs_e_AVeOR2MaYgSM7OOUstg9V9e8D4zZngdjKw@mail.gmail.com>
Subject: Re: [PATCH net-next 2/3] net: dsa: microchip: add ksz9567 to ksz9477 driver
To:     Marek Vasut <marex@denx.de>
Cc:     netdev@vger.kernel.org, Woojung Huh <woojung.huh@microchip.com>,
        Andrew Lunn <andrew@lunn.ch>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Tristram Ha <Tristram.Ha@microchip.com>,
        "David S. Miller" <davem@davemloft.net>,
        open list <linux-kernel@vger.kernel.org>
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On Fri, Sep 6, 2019 at 4:42 PM Marek Vasut <marex@denx.de> wrote:
>
> On 9/6/19 11:30 PM, George McCollister wrote:
> > Add support for the KSZ9567 7-Port Gigabit Ethernet Switch to the
> > ksz9477 driver. The KSZ9567 supports both SPI and I2C. Oddly the
> > ksz9567 is already in the device tree binding documentation.
> >
> > Signed-off-by: George McCollister <george.mccollister@gmail.com>
> > ---
> >  drivers/net/dsa/microchip/ksz9477.c     | 9 +++++++++
> >  drivers/net/dsa/microchip/ksz9477_i2c.c | 1 +
> >  drivers/net/dsa/microchip/ksz9477_spi.c | 1 +
> >  3 files changed, 11 insertions(+)
> >
> > diff --git a/drivers/net/dsa/microchip/ksz9477.c b/drivers/net/dsa/micr=
ochip/ksz9477.c
> > index 187be42de5f1..50ffc63d6231 100644
> > --- a/drivers/net/dsa/microchip/ksz9477.c
> > +++ b/drivers/net/dsa/microchip/ksz9477.c
> > @@ -1529,6 +1529,15 @@ static const struct ksz_chip_data ksz9477_switch=
_chips[] =3D {
> >               .cpu_ports =3D 0x07,      /* can be configured as cpu por=
t */
> >               .port_cnt =3D 3,          /* total port count */
> >       },
> > +     {
> > +             .chip_id =3D 0x00956700,
> > +             .dev_name =3D "KSZ9567",
> > +             .num_vlans =3D 4096,
> > +             .num_alus =3D 4096,
> > +             .num_statics =3D 16,
> > +             .cpu_ports =3D 0x7F,      /* can be configured as cpu por=
t */
> > +             .port_cnt =3D 7,          /* total physical port count */
>
> I might be wrong, and this is just an idea for future improvement, but
> is .cpu_ports =3D GEN_MASK(.port_cnt, 0) always ?

GENMASK, not GEN_MASK. And I think it would be .cpu_ports =3D
GENMASK(.port_cnt - 1, 0).
I'm not sure if it would always be that. TBH I'm not sure if 0x7F is
even correct. For instance if a port has a PHY should it be excluded
from this mask or only if it doesn't support tail tagging? Maybe
someone would hook the CPU port up with a PHY instead of
RGMII/MII/RMII but it seems quite an odd thing to do.

On the KSZ9567R datasheet it shows 1-7 for this so if actually correct
I believe all ports support tail tagging but maybe some other variants
don't:
Port Operation Control 0 Register
Port N: 1-7
Bit 2 - Tail Tag Enable
When tail tagging is enabled for a port, it designates that port to be
the =E2=80=9Chost=E2=80=9D or =E2=80=9CCPU=E2=80=9D port. Do not enable tai=
l tagging for more than one
port.

My inclination is to leave it as is until a more compelling reason for
changing it arises.

>
> > +     },
> >  };
> >
> >  static int ksz9477_switch_init(struct ksz_device *dev)
> > diff --git a/drivers/net/dsa/microchip/ksz9477_i2c.c b/drivers/net/dsa/=
microchip/ksz9477_i2c.c
> > index 85fd0fb43941..c1548a43b60d 100644
> > --- a/drivers/net/dsa/microchip/ksz9477_i2c.c
> > +++ b/drivers/net/dsa/microchip/ksz9477_i2c.c
> > @@ -77,6 +77,7 @@ MODULE_DEVICE_TABLE(i2c, ksz9477_i2c_id);
> >  static const struct of_device_id ksz9477_dt_ids[] =3D {
> >       { .compatible =3D "microchip,ksz9477" },
> >       { .compatible =3D "microchip,ksz9897" },
> > +     { .compatible =3D "microchip,ksz9567" },
> >       {},
> >  };
> >  MODULE_DEVICE_TABLE(of, ksz9477_dt_ids);
> > diff --git a/drivers/net/dsa/microchip/ksz9477_spi.c b/drivers/net/dsa/=
microchip/ksz9477_spi.c
> > index 2e402e4d866f..f4198d6f72be 100644
> > --- a/drivers/net/dsa/microchip/ksz9477_spi.c
> > +++ b/drivers/net/dsa/microchip/ksz9477_spi.c
> > @@ -81,6 +81,7 @@ static const struct of_device_id ksz9477_dt_ids[] =3D=
 {
> >       { .compatible =3D "microchip,ksz9893" },
> >       { .compatible =3D "microchip,ksz9563" },
> >       { .compatible =3D "microchip,ksz8563" },
> > +     { .compatible =3D "microchip,ksz9567" },
> >       {},
> >  };
> >  MODULE_DEVICE_TABLE(of, ksz9477_dt_ids);
> >
>
> Reviewed-by: Marek Vasut <marex@denx.de>

Thanks.

>
> --
> Best regards,
> Marek Vasut