Re: [PATCH 3/3] arm64: dts: freescale: imx95-toradex-smarc: Use gpio-hog for WIFI_UART_EN

[Francesco Dolcini <francesco@dolcini.it>]

On Wed, Mar 25, 2026 at 10:54:46AM -0400, Frank Li wrote:
> On Wed, Mar 25, 2026 at 12:55:11PM +0100, Franz Schnyder wrote:
> > From: Franz Schnyder <franz.schnyder@toradex.com>
> >
> > On the Toradex SMARC iMX95, the WiFi UART signals are shared with the
> > JTAG. The WIFI_UART_EN signal is used to select between these
> > two functions.
> >
> > Configure the signal as gpio-hog and drive it high to select the UART
> > function by default. Add a label to override the hog in derived
> > device trees.
> 
> gpio hog have problem about probe order, are you sure gpio device probe
> before pcie?

This is not about PCIe, we are talking about UART here. Specifically the
module is a combo Wi-Fi/BT device, with Wi-Fi over SDIO, and BT over
UART from NXP.

In any case, this DT is going to be used also by the boot firmware that will
configure the GPIO hog way before the Linux driver probes.

The DT files from the Linux kernel are used also by other projects.

> I have not seen any place refer to wifi_uart_en.

There is none (as of now). This is there to make it easier for a user
that needs access to debug to adjust this node enabling the JTAG
functionality.

Francesco