Connecting Murata Wifi/BLE to iMX6ULEVK

[sajiddalvi]

I have been following Murata's Getting Started Guide for the Wifi and BT dev kit (Type 1DX) for iMX6 platform.
PDF | Murata Manufacturing

I am using the latest iMX kernel version I managed to get Wifi working however am having trouble with Bluetooth.
The bcmdhd.ko was built using IMX's latest yocto distribution for kernel 4.1.15

I set up the device tree in uboot to imx6ul-14x14-evk-btwifi.dtb

I copied fw_bcmdhd.bin, bcmdhd.1DX.SDIO.cal and BCM4335C0.ZP.hcd to /etc/firmware. I extracted these from sdcard image link for iMX6UL-EVK provided in the Murata Getting Started guide.

I manually installed the module using :

insmod bcmdhd.ko firmware_path=/home/root/fw_bcmdhd.bin nvram_path=/home/root/bcmdhd.1DX.SDIO.cal

Wifi works with this, However for BLE I am unable to see a ttyXX interface on which to do an HCI attach.

The instruction in the Murata Getting Started Guide that I am stuck on is :

7.2.4 i.MX 6UltraLite EVK (V2 Adapter)

echo 252 > /sys/class/gpio/export

This gives me the following error :

imx6ulevk login: rootroot@imx6ulevk:~# echo 252 > /sys/class/gpio/exportexport_store: invalid GPIO 252-sh: echo: write error: Invalid argumentroot@imx6ulevk:~#

Don't quite understand what 252 means.

Based on my understanding this will end up being GPIO8_28 but IMX doesn't have a GPIO8 bank.

[jimmychan · Accepted solution]

According to the i.MX6ULEVK schematic, the BT_nPWD connected to the 74LV595PW which is used for extending the GPIO connections (8 GPIOs Q0-Q7). The input signals of 74LV595PW is using gpio-to-spi signals. So, the corresponding gpio signals of Q0-Q7 are gpio_spi0 to gpio_spi7. In the kernel configuration, please enable the SPI_GPIO.  The Q0-Q7 are gpio248 to gpio255.

Q4 is connected to BT_nPWD : so it is gpio 252.

[sajiddalvi]

Thanks jimmychan​

On my board with linux 4.1.15 I found that the SPI gpio expander was actually setup with a base of

gpiochip504 -> ../../devices/platform/spi4/spi_master/spi32766/spi32766.0/gpio/gpiochip504

So to get to the BT_nPWD I used gpio 508.

[djoygaurav]

Thanks sajiddalvi,

I Think you made a mistake in last line of your comment above "So to get to the BT_nPWD I used gpio 508 ". It must be 504 here.This same worked for me too,but only when i booted up with “fsl-image-gui-x11-imx6ul.rootfs.sdcard” image.When I am booting it with "my_project.rootfs.sdcard" image, its giving some problem which might be because I replaced "init with " systemd " init manager. Some log started appearing repeatedly just when I did boot after setting environment variable using "setenv fdt_file imx6ul-14x14-evk-btwifi.dtb" command. Please Help!!