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Date:   Tue, 13 Sep 2022 14:23:01 +0200
From:   Horatiu Vultur <horatiu.vultur@microchip.com>
To:     Michael Walle <michael@walle.cc>
CC:     <UNGLinuxDriver@microchip.com>, <andrew@lunn.ch>,
        <davem@davemloft.net>, <edumazet@google.com>,
        <hkallweit1@gmail.com>, <kuba@kernel.org>,
        <linux-kernel@vger.kernel.org>, <linux@armlinux.org.uk>,
        <netdev@vger.kernel.org>, <pabeni@redhat.com>
Subject: Re: [PATCH net-next] net: phy: micrel: Add interrupts support for
 LAN8804 PHY
Message-ID: <20220913122301.362ap6zghpdpluci@soft-dev3-1.localhost>
References: <20220912195650.466518-1-horatiu.vultur@microchip.com>
 <20220913081814.212548-1-michael@walle.cc>
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In-Reply-To: <20220913081814.212548-1-michael@walle.cc>
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The 09/13/2022 10:18, Michael Walle wrote:
> 
> > Add support for interrupts for LAN8804 PHY.
> >
> > Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
> > ---
> >  drivers/net/phy/micrel.c | 55 ++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 55 insertions(+)
> >
> > diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> > index 7b8c5c8d013e..98e9bc101d96 100644
> > --- a/drivers/net/phy/micrel.c
> > +++ b/drivers/net/phy/micrel.c
> > @@ -2676,6 +2676,59 @@ static int lan8804_config_init(struct phy_device *phydev)
> >       return 0;
> >  }
> >
> > +static irqreturn_t lan8804_handle_interrupt(struct phy_device *phydev)
> > +{
> > +     int status;
> > +
> > +     status = phy_read(phydev, LAN8814_INTS);
> > +     if (status < 0) {
> > +             phy_error(phydev);
> > +             return IRQ_NONE;
> > +     }
> > +
> > +     if (status > 0)
> > +             phy_trigger_machine(phydev);
> > +
> > +     return IRQ_HANDLED;
> > +}
> > +
> > +#define LAN8804_OUTPUT_CONTROL                       25
> > +#define LAN8804_OUTPUT_CONTROL_INTR_BUFFER   BIT(14)
> > +#define LAN8804_CONTROL                              31
> > +#define LAN8804_CONTROL_INTR_POLARITY                BIT(14)
> > +
> > +static int lan8804_config_intr(struct phy_device *phydev)
> > +{
> > +     int err;
> > +
> > +     /* Change interrupt polarity */
> > +     phy_write(phydev, LAN8804_CONTROL, LAN8804_CONTROL_INTR_POLARITY);
> 
> I assume you change the polarity to high active? Could you add a note?
> The LAN966x nor the LAN8804 datasheet describe this bit. You might also add
> a note, that this is an internal PHY and you cannot change the polarity on
> the GIC. Which begs the question, is this really only an internal PHY or
> can you actually buy it as a dedicated one. Then you'd change the polarity
> in a really unusual way.

That is correct, as you described it, I change the polarity to high.
From what I know, you can't buy a dedicated PHY.
I will add these notes in the next version.

> 
> 
> > +
> > +     /* Change interrupt buffer type */
> 
> To what? Push-pull?

Yes, I have changed it to push-pull.
I will add a node in the next version.

> 
> -michael
> 
> > +     phy_write(phydev, LAN8804_OUTPUT_CONTROL,
> > +               LAN8804_OUTPUT_CONTROL_INTR_BUFFER);
> > +

-- 
/Horatiu