From: Michal Simek <michal.simek@xilinx.com>
To: Harini Katakam <harinik@xilinx.com>, Andrew Lunn <andrew@lunn.ch>
Cc: Michal Simek <michal.simek@xilinx.com>,
Paul Kocialkowski <paul.kocialkowski@bootlin.com>,
Florian Fainelli <f.fainelli@gmail.com>, <netdev@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>,
"David S . Miller" <davem@davemloft.net>,
Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
Heiner Kallweit <hkallweit1@gmail.com>
Subject: Re: [PATCH RESEND net] net: phy: xgmiitorgmii: Support generic PHY status read
Date: Mon, 11 Mar 2019 13:51:18 +0100 [thread overview]
Message-ID: <12abec9f-29a8-7dfc-b7cc-59be34e1b6d7@xilinx.com> (raw)
In-Reply-To: <CAFcVECK8=6WMi4uDU-HBxzPxUwU=rRXM385wUup_fd9bHQvwwQ@mail.gmail.com>
On 11. 03. 19 13:27, Harini Katakam wrote:
> Hi Andrew,
> On Mon, Mar 11, 2019 at 11:34 AM Harini Katakam <harinik@xilinx.com> wrote:
>>
>> Hi Andrew,
>> On Sat, Mar 9, 2019 at 9:53 PM Andrew Lunn <andrew@lunn.ch> wrote:
>>>
>>>> Related to this, I have a query on how the DT node for gmii2rgmii should look.
>>>> One of the users of gmii2rgmii is Cadence macb driver. In Xilinx tree, we use
>>>> this piece of code to register this mdiobus:
>>>> + mdio_np = of_get_child_by_name(np, "mdio");
>>>> + if (mdio_np) {
>>>> + of_node_put(mdio_np);
>>>> + err = of_mdiobus_register(bp->mii_bus, mdio_np);
>>>> + if (err)
>>>> + goto err_out_unregister_bus;
>>>>
>>>> And the DT node looks like this:
>>>> ethernet {
>>>> phy-mode = "gmii";
>>>> phy-handle = <&extphy>;
>>>>
>>>> mdio {
>>>> extphy {
>>>> reg = <x>;
>>>> };
>>>> gmii_to_rgmii{
>>>> compatible = "xlnx,gmii-to-rgmii-1.0";
>>>> phy-handle = <&extphy>;
>>>> reg = <x>;
>>>> };
>>>> };
>>>> };
>>>
>>> Hi Harini
>>>
>>> You have this setup:
>>>
>>> MAC <==> GMII2RGMII <==> RGMII_PHY
>>>
>>> So you want the MAC phy-handle to point to the gmii_to_rgmii 'PHY'.
>>>
>>> Feel free to submit a patch extending
>>> Documentation/devicetree/bindings/net/xilinx_gmii2rgmii.txt to include
>>> a MAC node, etc.
>>
>> Thank you, will do the same.
>
> Thanks again for your input. So, I did some testing with this change.
> But the issue is that, if I point the phy-handle to gmi2rgmii,
> of_phy_connect will be called from the MAC and it will fail because gmii2rgmii
> is not a PHY driver and it does not have a standard PHY register set or ID.
> Which goes back to the discussion above whether this needs to changed in the IP.
>
> But right now, it is a bridge device on the MDIO bus and has no PHY
> functionality.
> Moreover, any MAC is capable of accessing the external PHY with no interference
> in the MDIO path (the gmii2rgmii bridge just acts like another device
> on a common bus).
>
> What Michal suggested below in uboot is that they register gmii2rgmii
> with a dummy
> PHY ID and then attach the external phy driver in its probe. I'm not
> sure if this will work
> in linux i.e. calling phy_connect_direct inside the gmii2rgmii probe.
In u-boot behavior and wiring is similar to fixed-link phy.
Thanks,
Michal
next prev parent reply other threads:[~2019-03-11 12:51 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-15 16:32 [PATCH RESEND net] net: phy: xgmiitorgmii: Support generic PHY status read Paul Kocialkowski
2019-02-15 17:02 ` Andrew Lunn
2019-02-15 17:38 ` Florian Fainelli
2019-02-15 18:34 ` Paul Kocialkowski
2019-02-15 18:53 ` Florian Fainelli
2019-02-19 9:56 ` Paul Kocialkowski
2019-02-19 17:25 ` Andrew Lunn
2019-02-20 6:58 ` Michal Simek
2019-02-21 10:24 ` Paul Kocialkowski
2019-02-21 11:03 ` Michal Simek
2019-02-27 8:43 ` Michal Simek
2019-02-27 9:05 ` Harini Katakam
2019-02-28 7:33 ` Harini Katakam
2019-03-09 12:09 ` Harini Katakam
2019-03-09 16:19 ` Andrew Lunn
2019-03-11 6:04 ` Harini Katakam
2019-03-11 12:27 ` Harini Katakam
2019-03-11 12:51 ` Michal Simek [this message]
2019-03-11 6:45 ` Michal Simek
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