i.MX ProcessorsのトピックRe: wifi device tree

wifi device tree

sumosumo — Sun, 05 Jun 2016 21:25:31 GMT

Hi all

I am using wandboard quad and made a minimal filesystem and kernel under yocto framework.

Wifi wasn't working with the minimal image , so I manually added the wifi driver (bcm4329-fmac) and the suitable firmware.

my question is: How come wifi is working (there is an interface and i get results on "iw wlan0 scan") without updating the device tree files (I did not encountered any compatible name "bcm4329-fmac") ?

Thanks

Re: wifi device tree

weidong_sun — Mon, 06 Jun 2016 04:06:02 GMT

Hello sumo,

It is very necessary to add wifi to device tree, for example:

(1) Multiplexing SDIO PINs connected to WIFI card

(2) Initializing corresponding data structure of SDIO

(3) Initializing GPIOs for controlling WIFI's power and reset.

...

Above work must be done in BSP.

Hope above advice can help you !

Regards,

Weidong

Re: wifi device tree

sumosumo — Mon, 06 Jun 2016 07:12:19 GMT

Hi Weidong Sun

First, thanks for your quick reply.

I understand that with the device tree you can config GPIOs, IRQ etc.. (and basically and more generally, initialize the pdev pointer which is sent to the probe function with the relevant values)

What I still did not get is how (in this case) the kernel registered the wifi driver if there is no compatible field associated to that driver?

Best Regards

Re: wifi device tree

weidong_sun — Tue, 07 Jun 2016 04:25:32 GMT

Hello sumo,

compatible field should be in your wifi driver, you can check if there exists a file name of.c, and search the filed.

Regards,

Weidong

Re: wifi device tree

sumosumo — Tue, 07 Jun 2016 08:12:41 GMT

shouldn't compatible field be in the driver (of.c in this case) and in the dts file as well ?

Isn't compatible field who makes the binding between device-tree and the driver ?

Thanks !