RMII in SoloX

[alessandrofracc]

Hello everybody

We're working on a custom board derived from Sabre-SDB 6SX rev.c

Sabre has two PHYs. Since oscillators aren't physically present, their clock is provided by ENET_PHY_CLK1 that is ENET_REF_CLK_25M. ENET_REF_CLK_25M is connected to the pad ENET2_RX_CLK.

In fact we measure 50MHz.

Our custom board has one DP83848 as PHY, configured for RMII mode.

Unfortunately ENET2_RX_CLK supplies 25MHz and I don't know why.

We expect 50MHz because settings are equal to the Sabre.

Can anyone help us?

[robertlehmann]

Did you found a solution. I'm heading into the same problem.

Thank you.

~Robert

[Yuri]

Hello,

  What is Your Linux BSP, .dtb ?

Have Your tried the recent BSP ?

i.MX 6 Series Software and Development Tool|NXP

Have a great day,
Yuri

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[alessandrofracc]

Hello Yuri

we’re using Android 5.0.0 Lollipop and imx6sx-sdb.dts . There are no pin conflicts.

In imx6sx.dtsi we have

pinctrl_enet1_1: enet1grp-1 {

fsl,pins = <<br /> MX6SX_PAD_ENET1_MDIO__ENET1_MDIO 0xa0b1
MX6SX_PAD_ENET1_MDC__ENET1_MDC 0xa0b1
MX6SX_PAD_RGMII1_TXC__ENET1_RGMII_TXC 0xa0b9
MX6SX_PAD_RGMII1_TD0__ENET1_TX_DATA_0 0xa0b1
MX6SX_PAD_RGMII1_TD1__ENET1_TX_DATA_1 0xa0b1
MX6SX_PAD_RGMII1_TD2__ENET1_TX_DATA_2 0xa0b1
MX6SX_PAD_RGMII1_TD3__ENET1_TX_DATA_3 0xa0b1
MX6SX_PAD_RGMII1_TX_CTL__ENET1_TX_EN 0xa0b1
MX6SX_PAD_RGMII1_RXC__ENET1_RX_CLK 0x3081
MX6SX_PAD_RGMII1_RD0__ENET1_RX_DATA_0 0x3081
MX6SX_PAD_RGMII1_RD1__ENET1_RX_DATA_1 0x3081
MX6SX_PAD_RGMII1_RD2__ENET1_RX_DATA_2 0x3081
MX6SX_PAD_RGMII1_RD3__ENET1_RX_DATA_3 0x3081
MX6SX_PAD_RGMII1_RX_CTL__ENET1_RX_EN 0x3081

//MX6SX_PAD_ENET1_TX_CLK__ENET1_REF_CLK1 0x40010091
>;
};

pinctrl_enet1_clkout_1: enet1_clkoutgrp-1 {
fsl,pins = <<br /> MX6SX_PAD_ENET2_RX_CLK__ENET2_REF_CLK_25M 0x91
>;
};

In imx6sx-sdb.dts we have

&fec1 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_enet1_1 &pinctrl_enet1_clkout_1>;
phy-mode = "rmii";
fsl,num_tx_queues=<3>;
fsl,num_rx_queues=<3>;

status = "okay";

};

I don’t understand how ENET2_RX_CLK supplies 50MHz in the Sabre board but in ours.

Thanx, Alessandro

Da: Yuri

Inviato: giovedì 12 maggio 2016 10:42

A: Alessandro Fraccaro

Oggetto: Re: - RMII in SoloX

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RMII in SoloX

reply from Yuri Muhin<https://community.freescale.com/people/Yuri?et=watches.email.thread> in i.MX Community - View the full discussion<https://community.freescale.com/message/644362?et=watches.email.thread#comment-644362>

[Yuri]

Hello,

The following may be helpful :

Linux/arch/arm/boot/dts/imx6sx-sdb.dtsi - Linux Cross Reference - Free Electrons

RMII interface on i.MX6SX

Have a great day,
Yuri

[alessandrofracc]

I’m going to follow your suggestion.

Thanx Yuri