T1042 Device Tree Fman RGMII-ID

[stefanlange]

Hello NXP team,

we have a design with a custom NXP T1042 PowerPC Module located on a custom baseboard. 

Both module and baseboard are new designs.

I here have a support request regarding the Fman device tree content and syntax.

There are 5 Ethernet Interfaces in use, 3 via SGMII, 2 via RGMII.

The RGMIIs require editing the specific TX and RX RGMII delays in the phy.

I have implemented this in the device tree to my best guess (see attached).

However it seems the parameter

phy-connection-type = "rgmii-id";

is ignored during kernel boot, and thus the RGMII delay values are not set.

I also changed the parameter phy-connection-type = "sgmii"; to phy-connection-type = "aaa"; for a test

The debug print still remained at "sgmii"; it seems phy-connection-type as put in the device tree is not used at all.

See attached my .dts file and a bootlog with debug prints and comments (marked with "?").

I figure I wrote the .dts wrong in some way. I could not find a different device tree that I could use as a template.

Maybe you can shed some light.

Thank you and best regards,

Stefan

Original Attachment has been moved to: tqmt1042.dts.zip

Original Attachment has been moved to: TQMT1042_Bootlog.txt.zip

[stefanlange · Accepted solution]

Hello all,

for what it's worth, I wrote a quick dirty patch for myself to solve this issue for myself.

See below.

Best regards,

Stefan

####################

commit c6dffe1f34476fbb0653328521ab4124f204b007

Author: Stefan Lange <s.lange@gateware.de>

Date:   Wed Jul 13 17:37:34 2016 +0200

        Workaround to enable rgmii-id phy-connection-type with QorIQ Frame Manag

        Dirty Workaround:

        Get the true external PHY's connection type

        Workaround as FMAN overwrites the "phy-connection-type"-property

        with "rgmii" if "rgmii-id" is noted in the device tree.

        The new variable "external_phy_if" is successively used in the

        "init_phy" function further above in this .c-file.

        See also: https://community.nxp.com/thread/398029

diff --git a/arch/powerpc/boot/dts/fsl/tqmt1042.dts b/arch/powerpc/boot/dts/fsl/

index cde8d2f..e81d236 100644

--- a/arch/powerpc/boot/dts/fsl/tqmt1042.dts

+++ b/arch/powerpc/boot/dts/fsl/tqmt1042.dts

@@ -263,12 +263,14 @@

                        enet3: ethernet@e6000 {

                                phy-handle = <&phy_rgmii_0>;

                                phy-connection-type = "rgmii-id";

+                               external-phy-connection-type = "rgmii-id";

                        };

                        /* MAC5: RGMII DP83867 */

                        enet4: ethernet@e8000 {

                                phy-handle = <&phy_rgmii_1>;

                                phy-connection-type = "rgmii-id";

+                               external-phy-connection-type = "rgmii-id";

                        };

                        /* external, dedicated MDIO */

diff --git a/drivers/net/ethernet/freescale/fman/mac.c b/drivers/net/ethernet/fr

index e33d9d2..254e88c 100644

--- a/drivers/net/ethernet/freescale/fman/mac.c

+++ b/drivers/net/ethernet/freescale/fman/mac.c

@@ -67,6 +67,7 @@ struct mac_priv_s {

        struct fixed_phy_status         *fixed_link;

        u16                             speed;

        u16                             max_speed;

+       phy_interface_t                 external_phy_if;

        int (*enable)(struct fman_mac *mac_dev, enum comm_mode mode);

        int (*disable)(struct fman_mac *mac_dev, enum comm_mode mode);

@@ -476,8 +477,14 @@ static int init_phy(struct net_device *net_dev,

        struct phy_device       *phy_dev;

        struct mac_priv_s       *priv = mac_dev->priv;

-       phy_dev = of_phy_connect(net_dev, priv->phy_node, adj_lnk, 0,

+       if (priv->external_phy_if) {

+               phy_dev = of_phy_connect(net_dev, priv->phy_node, adj_lnk, 0,

+                                priv->external_phy_if);

+       }

+       else {

+               phy_dev = of_phy_connect(net_dev, priv->phy_node, adj_lnk, 0,

                                 priv->phy_if);

+       }

        if (!phy_dev) {

                netdev_err(net_dev, "Could not connect to PHY\n");

                return -ENODEV;

@@ -881,6 +888,23 @@ static int mac_probe(struct platform_device *_of_dev)

                priv->phy_if = str2phy(char_prop);

        }

+       /*

+        * Dirty Workaround:

+        * Get the true external PHY's connection type

+        * Workaround as FMAN overwrites the "phy-connection-type"-property

+        * with "rgmii" if "rgmii-id" is noted in the device tree.

+        * The new variable "external_phy_if" is successively used in the

+        * "init_phy" function further above in this .c-file.

+        * See also: https://community.nxp.com/thread/398029

+        */

+       char_prop = (const char *)of_get_property(mac_node,

+                                                 "external-phy-connection-type"

+       if (char_prop) {

+               dev_info(dev,"'external-phy-connection-type' property present in

+               dev_info(dev,"'external-phy-connection-type' set to %s \n", char

+               priv->external_phy_if = str2phy(char_prop);

+       }

+

        priv->speed             = phy2speed[priv->phy_if];

        priv->max_speed         = priv->speed;

        mac_dev->if_support     = DTSEC_SUPPORTED;

[stefanlange]

Hello NXP team,

this issue is still pending.

We would be glad about a hint.

Best regards,

Stefan

[stefanlange]

Hello Avinash,

still waiting on the reply from NXP.

With some ethernet PHYs it is possible to set the RGMII delay via external strapping resistors. This might be a fallback solution in your case.

Best regards,
Stefan

[avinashh]

Hi Stefan,

I am experiencing a similar problem with my P2041 processor RGMII port, my RGMII-0 is working but not at 1Gbps and my RGMII-1 is not working at all even after implementing the delays in the PHY registers in the U-boot.

Maybe if you get a solution to your problem, you can help us also,

the link to my service request is: RGMII ETHERNET port of P2041 processor is showing alive in uboot but not pinging in kern

Thanks

Avinash

[bpe]

Your observations are fully correct. T1042 has no internal delay on

RGMII signlas, See Note 2 to Table 48 of T1042 HW spec. You cannot

configure for it in any way. The interface type is configured at reset and cannot be

changed in software, see T1042RM, Table 4-11, fields EC1, EC2. For

this reason,  'phy-connection-type' property is there only for the sake of

completeness. The actual interface type is determined from the chip

registers that reflect RCW settings.

Have a great day,
Platon

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[stefanlange]

Hello Platon,

thanks for your response.

This is in a way what I had expected.

But how can I set the external(!) RGMII phy's registers?

Best regards,

Stefan

[bpe]

In general, controlling a PHY is a burden of it's driver. Consult at your PHY manufacturer/documentation and driver

maintainer/source/documentation for supported methods of setting the PHY parameters.

Typically,  MAC/PHY interface type and parameters are fully static, thus internal delays are either

pin-configured at PHY reset, if the PHY has that option, or setup once by u-Boot. Linux actually don't

have to do anything with  it.

Have a great day,
Platon

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[stefanlange]

Hello NXP team,

this issue is still pending.

We would be glad about a hint.

Best regards,

Stefan

[stefanlange]

Hello Platon,

we are setting the PHY's internal delays in u-boot and the interface is working correctly in u-boot.

However once the ethernet interface is initialized / used in linux, e.g. via ifconfig fm1-gb3 <ipaddr>, linux resets thePHY and the delay settings are lost.

The DP83867 driver accounts for this, it has the option of setting tx-internal-delay, rx-internal-delay via the device tree.

But: The respective routines in the driver are called only if the ethernet device tree node is set to

phy-connection-type = "rgmii-id";

As the phy-connection-type attribute is ignored and hard-set to "rgmii", is there a way I can achieve the DP83867 sees phy-connection-type = "rgmii-id", or is there any other smart way to solve this?

Thanks & best regards,

Stefan