Date:   Sun, 26 Dec 2021 23:26:30 +0100
From:   Andrew Lunn <andrew@lunn.ch>
To:     "Russell King (Oracle)" <linux@armlinux.org.uk>
Cc:     Daniel Golle <daniel@makrotopia.org>,
        linux-mediatek@lists.infradead.org, netdev@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Felix Fietkau <nbd@nbd.name>, John Crispin <john@phrozen.org>,
        Sean Wang <sean.wang@mediatek.com>,
        Mark Lee <Mark-MC.Lee@mediatek.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>
Subject: Re: [PATCH] net: ethernet: mtk_eth_soc: implement Clause 45 MDIO
 access
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References: <YcjepQ2fmkPZ2+pE@makrotopia.org>
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 <YcjlMCacTTJ4RsSA@shell.armlinux.org.uk>
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On Sun, Dec 26, 2021 at 09:57:04PM +0000, Russell King (Oracle) wrote:
> On Sun, Dec 26, 2021 at 10:51:08PM +0100, Andrew Lunn wrote:
> > > +	if (phy_register & MII_ADDR_C45) {
> > > +		u8 dev_num = (phy_register >> 16) & 0x1f;
> > > +		u16 reg = (u16)(phy_register & 0xffff);
> > 
> > Hi Daniel
> > 
> > You can use the helpers
> > 
> > mdio_phy_id_is_c45()
> > mdio_phy_id_prtad()
> > mdio_phy_id_devad()
> 
> Before someone makes a mistake with this... no, don't use these. These
> are for the userspace MII ioctl API, not for drivers.

Ah, Sorry.

Thanks Russell, i got this wrong. I though there was some helpers for
this, and happened to land on bnxt_hwrm_port_phy_read(), without
checking what it was actually used for.

> The C45 register address can be extracted by masking with
> MII_REGADDR_C45_MASK. The C45 devad can be extracted by shifting right
> by MII_DEVADDR_C45_SHIFT and masking 5 bits. We don't have helpers for
> this.

Maybe we should have helpers.

      Andrew