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Subject: Re: user space interface for configuring T1 PHY management mode
 (master/slave)
To:     Oleksij Rempel <o.rempel@pengutronix.de>,
        David Miller <davem@davemloft.net>
Cc:     andrew@lunn.ch, f.fainelli@gmail.com, hkallweit1@gmail.com,
        mark.rutland@arm.com, robh+dt@kernel.org, kernel@pengutronix.de,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        david@protonic.nl, devicetree@vger.kernel.org,
        linux@armlinux.org.uk, olteanv@gmail.com
References: <20200325083449.GA8404@pengutronix.de>
From:   Marek Vasut <marex@denx.de>
Message-ID: <e2a1877c-1cb2-e047-38e0-e3b41d941b33@denx.de>
Date:   Wed, 25 Mar 2020 11:21:10 +0100
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On 3/25/20 9:34 AM, Oleksij Rempel wrote:
> Hi all,

Hi,

> I'm working on mainlining of NXP1102 PHY (BroadR Reach/802.3bw) support.
> 
> Basic functionality is working and support with mainline kernel. Now it is time
> to extend it. According to the specification, each PHY can be master or slave.
> 
> The HW can be pre configured via bootstrap pins or fuses to have a default
> configuration. But in some cases we still need to be able to configure the PHY
> in a different mode: 
> --------------------------------------------------------------------------------
> http://www.ieee802.org/3/1TPCESG/public/BroadR_Reach_Automotive_Spec_V3.0.pdf
> 
> 6.1 MASTER-SLAVE configuration resolution
> 
> All BroadR-Reach PHYs will default to configure as SLAVE upon power up or reset
> until a management system (for example, processor/microcontroller) configures
> it to be MASTER. MASTER-SLAVE assignment for each link configuration is
> necessary for establishing the timing control of each PHY.

Thanks for reminding me of this. I sent out
https://patchwork.ozlabs.org/project/netdev/list/?series=166575
maybe it helps.