> -----Original Message----- > From: Andrew Lunn <andrew@xxxxxxx> > Sent: 2024年8月16日 11:28 > To: Wei Fang <wei.fang@xxxxxxx> > Cc: davem@xxxxxxxxxxxxx; edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx; > pabeni@xxxxxxxxxx; robh@xxxxxxxxxx; krzk+dt@xxxxxxxxxx; > conor+dt@xxxxxxxxxx; f.fainelli@xxxxxxxxx; hkallweit1@xxxxxxxxx; > linux@xxxxxxxxxxxxxxx; Andrei Botila (OSS) <andrei.botila@xxxxxxxxxxx>; > netdev@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [PATCH net-next 1/3] dt-bindings: net: tja11xx: use reverse-mode > to instead of rmii-refclk-in > > > Based on the TJA data sheet, like TJA1103/TJA1104, if the reverse mode > > is set. If XMII_MODE is set to MII, the device operates in revMII mode > > (TXCLK and RXCLK are input). If XMII_MODE is set to RMII, the device > > operates in revRMII mode (REF_CLK is output). So it's just that the input > > and output directions of xx_CLK are reversed. > > we don't need to tell the MAC to play the role of the PHY, in our case, we > > just need the PHY to provide the reference clock in RMII mode. > > If this is purely about providing a reference clock, normally 25Mhz, > there are a few PHY drivers which support this. Find one and copy > it. There is no need to invent something new. > Sorry, I didn't find the correct PHY driver, could you point me to which PHY driver that I can refer to? The PHY drivers I searched for using the "clk" keyword all seem to set the clock via a vendor defined property. Such as, realtek: "realtek,clkout-disable" dp83867 and dp83869: "ti,clk-output-sel" and "ti,sgmii-ref-clock-output-enable" motorcomm: " motorcomm,tx-clk-1000-inverted" micrel: "rmii-ref"
