# Imx8mn - wifi on the SDIO interface debugging

**URL:** <https://forums.digi.com/t/imx8mn-wifi-on-the-sdio-interface-debugging/22985>\
**Category:** Linux\
**Tags:** wifi, sdio, yocto, digi, ccimx8mn\
**Created:** [March 4, 2022, 10:14am UTC](https://forums.digi.com/t/imx8mn-wifi-on-the-sdio-interface-debugging/22985 "2022-03-04T10:14:13Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![adi1525](https://avatars.discourse-cdn.com/v4/letter/a/a183cd/32.png) [@adi1525](https://forums.digi.com/u/adi1525)\
**Post date:** [March 4, 2022, 10:14am UTC](https://forums.digi.com/t/imx8mn-wifi-on-the-sdio-interface-debugging/22985/1 "2022-03-04T10:14:13Z")

</div>

I have built zeus 3.0 yocto image for imx8mn-dvk and I’m trying connect WiFi module CYW43455 via SDIO interface (plugged as sdCard - usdhc2 interface).

I have configured usdhc2 in device-tree according to MMC/SD/SDIO insctruction on Digi documentation but I can’t run module with brcmfmac.ko driver.

I can’t see this message in dmesg:

mmc1 new high speed SDIO card at address 0001

cat /sys/kernel/debug/mmc1/ios

clock: 0 Hz  
vdd: 0 (invalid)  
bus mode: 2 (push-pull)  
chip select: 0 (don’t care)  
power mode: 0 (off)  
bus width: 0 (1 bits)  
timing spec: 0 (legacy)  
signal voltage: 0 (3.30 V)  
driver type: 0 (driver type B)

I wonder if the information should appear after booting or after starting the driver?

When I boot system with sdCard it’s shows this:

[2.910610] mmc1: new high speed SDHC card at address 5048

Device tree configuration:

/\* External wifi module - SDIO \*/  
&usdhc2 {  
pinctrl-names = “default”, “state\_100mhz”, “state\_200mhz”;  
pinctrl-0 = \<&pinctrl\_usdhc2\>, \<&pinctrl\_usdhc2\_gpio\>,  
\<&pinctrl\_usdhc2\_vsel\>;  
pinctrl-1 = \<&pinctrl\_usdhc2\_100mhz\>, \<&pinctrl\_usdhc2\_gpio\>,  
\<&pinctrl\_usdhc2\_vsel\>;  
pinctrl-2 = \<&pinctrl\_usdhc2\_200mhz\>, \<&pinctrl\_usdhc2\_gpio\>,  
\<&pinctrl\_usdhc2\_vsel\>;  
non-removable;  
no-1-8-v;  
bus-width = \<4\>;  
vmmc-supply = \<&reg\_rf\_wl\_en\_2\>;  
cd-gpios = \<&gpio2 12 GPIO\_ACTIVE\_HIGH\>;  
status = “okay”;  
};

reg\_rf\_wl\_en\_2: regulator@8 {  
compatible = “regulator-fixed”;  
reg = \<8\>;  
pinctrl-names = “default”;  
pinctrl-0 = \<&pinctrl\_reg\_3v3\_rf\>;  
regulator-name = “rf\_wl\_en\_2”;  
regulator-min-microvolt = \<3300000\>;  
regulator-max-microvolt = \<3300000\>;  
enable-active-high;  
startup-delay-us = \<100\>;  
vin-supply = \<&reg\_3v3\_rf\>;  
status = “okay”;  
};  
pinctrl\_usdhc2\_vsel: usdhc2grp\_vsel {  
fsl,pins = \<  
MX8MN\_IOMUXC\_GPIO1\_IO04\_USDHC2\_VSELECT 0x1d0  
\>;  
};  
pinctrl\_usdhc2: usdhc2grp {  
fsl,pins = \<  
MX8MN\_IOMUXC\_SD2\_CLK\_USDHC2\_CLK 0x190  
MX8MN\_IOMUXC\_SD2\_CMD\_USDHC2\_CMD 0x1d0  
MX8MN\_IOMUXC\_SD2\_DATA0\_USDHC2\_DATA0 0x1d0  
MX8MN\_IOMUXC\_SD2\_DATA1\_USDHC2\_DATA1 0x1d0  
MX8MN\_IOMUXC\_SD2\_DATA2\_USDHC2\_DATA2 0x1d0  
MX8MN\_IOMUXC\_SD2\_DATA3\_USDHC2\_DATA3 0x1d0  
\>;  
};

Thanks for help.

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<div class="post-metadata">

**Author:** ![LeonidM](https://avatars.discourse-cdn.com/v4/letter/l/d26b3c/32.png) [@LeonidM](https://forums.digi.com/u/LeonidM)\
**Post date:** [March 10, 2022, 10:39am UTC](https://forums.digi.com/t/imx8mn-wifi-on-the-sdio-interface-debugging/22985/2 "2022-03-10T10:39:11Z")

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are you using Digi cc8mn and trying to add 2nd wifi interface? Are you able to see it in u-boot with  
mmc rescan  
mmc dev 1  
mmc info

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<div class="post-metadata">

**Author:** ![adi1525](https://avatars.discourse-cdn.com/v4/letter/a/a183cd/32.png) [@adi1525](https://forums.digi.com/u/adi1525)\
**Post date:** [March 17, 2022, 5:06am UTC](https://forums.digi.com/t/imx8mn-wifi-on-the-sdio-interface-debugging/22985/3 "2022-03-17T05:06:04Z")

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Yes I’m using Digi cc8mn with the second wifi module over SDIO. I have connected it via sdCard socket.

After plugged the modem, response from commands from you:

=\> mmc dev 1  
=\> mmc info  
Device: FSL\_SDHC  
Manufacturer ID: 13  
OEM: 14e  
Name: Q2J55  
Bus Speed: 52000000  
Mode: MMC High Speed (52MHz)  
Rd Block Len: 512  
MMC version 5.0  
High Capacity: Yes  
Capacity: 7.1 GiB  
Bus Width: 8-bit  
Erase Group Size: 512 KiB  
HC WP Group Size: 8 MiB  
User Capacity: 7.1 GiB WRREL  
Boot Capacity: 16 MiB ENH  
RPMB Capacity: 4 MiB ENH  
=\>

I think that the response from mmc info is for mmc0.

One more thing, I didn’t configure device tree for uboot, I configured it for kernel only.

Sorry I din’t respond for long time but I was working on another project.

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<div class="post-metadata">

**Author:** ![adi1525](https://avatars.discourse-cdn.com/v4/letter/a/a183cd/32.png) [@adi1525](https://forums.digi.com/u/adi1525)\
**Post date:** [March 17, 2022, 8:18am UTC](https://forums.digi.com/t/imx8mn-wifi-on-the-sdio-interface-debugging/22985/4 "2022-03-17T08:18:52Z")

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Yes I’m using Digi cc8mn with the second wifi module over SDIO. I have connected it via sdCard socket.

After plugged the modem, response from commands from you:

=\> mmc dev 1  
=\> mmc info  
Device: FSL\_SDHC  
Manufacturer ID: 13  
OEM: 14e  
Name: Q2J55  
Bus Speed: 52000000  
Mode: MMC High Speed (52MHz)  
Rd Block Len: 512  
MMC version 5.0  
High Capacity: Yes  
Capacity: 7.1 GiB  
Bus Width: 8-bit  
Erase Group Size: 512 KiB  
HC WP Group Size: 8 MiB  
User Capacity: 7.1 GiB WRREL  
Boot Capacity: 16 MiB ENH  
RPMB Capacity: 4 MiB ENH  
=\>  
I think that the response from mmc info is for mmc0.  
One more thing, I didn’t configure device tree for uboot, I configured it for kernel only.

Sorry I din’t respond for long time but I was working on another project.