The U-Blox EVK-M101 enumerates as 1546:0506 [1] with four FTDI interfaces:
- EVK-M101 current sensors
- EVK-M101 I2C
- EVK-M101 UART
- EVK-M101 port D

Only the third USB interface is a UART. This change lets ftdi_sio probe
the VID/PID and registers only interface #3 as a TTY, leaving the rest
available for other drivers.

[1]
usb 5-1.3: new high-speed USB device number 11 using xhci_hcd
usb 5-1.3: New USB device found, idVendor=1546, idProduct=0506, bcdDevice= 8.00
usb 5-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
usb 5-1.3: Product: EVK-M101
usb 5-1.3: Manufacturer: u-blox AG

Datasheet: https://content.u-blox.com/sites/default/files/documents/EVK-M10_UserGuide_UBX-21003949.pdf

Link: https://lore.kernel.org/all/20251030090056.3175217-1-cryosay@gmail.com/
Signed-off-by: Oleksandr Suvorov <cryosay@gmail.com>
---
v3:
 - Use USB_DEVICE_INTERFACE_NUMBER instead of custom probe()
v2:
 - Restrict probing to interface #3 only
 - Add a device model to commit message
 - Fix grammar in commit message
 - Add Link: to v1
Signed-off-by: Oleksandr Suvorov <cryosay@gmail.com>
---
 drivers/usb/serial/ftdi_sio.c     | 1 +
 drivers/usb/serial/ftdi_sio_ids.h | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 49666c33b41f..b37fa31f5694 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1074,6 +1074,7 @@ static const struct usb_device_id id_table_combined[] = {
 	/* U-Blox devices */
 	{ USB_DEVICE(UBLOX_VID, UBLOX_C099F9P_ZED_PID) },
 	{ USB_DEVICE(UBLOX_VID, UBLOX_C099F9P_ODIN_PID) },
+	{ USB_DEVICE_INTERFACE_NUMBER(UBLOX_VID, UBLOX_EVK_M101_PID, 2) },
 	/* FreeCalypso USB adapters */
 	{ USB_DEVICE(FTDI_VID, FTDI_FALCONIA_JTAG_BUF_PID),
 		.driver_info = (kernel_ulong_t)&ftdi_jtag_quirk },
diff --git a/drivers/usb/serial/ftdi_sio_ids.h b/drivers/usb/serial/ftdi_sio_ids.h
index 4cc1fae8acb9..2539b9e2f712 100644
--- a/drivers/usb/serial/ftdi_sio_ids.h
+++ b/drivers/usb/serial/ftdi_sio_ids.h
@@ -1614,6 +1614,7 @@
 #define UBLOX_VID			0x1546
 #define UBLOX_C099F9P_ZED_PID		0x0502
 #define UBLOX_C099F9P_ODIN_PID		0x0503
+#define UBLOX_EVK_M101_PID		0x0506
 
 /*
  * GMC devices
-- 
2.48.1

On Thu, Oct 30, 2025 at 05:42:54PM +0200, Oleksandr Suvorov wrote:
> The U-Blox EVK-M101 enumerates as 1546:0506 [1] with four FTDI interfaces:
> - EVK-M101 current sensors
> - EVK-M101 I2C
> - EVK-M101 UART
> - EVK-M101 port D
> 
> Only the third USB interface is a UART. This change lets ftdi_sio probe
> the VID/PID and registers only interface #3 as a TTY, leaving the rest
> available for other drivers.

> ---
> v3:
>  - Use USB_DEVICE_INTERFACE_NUMBER instead of custom probe()
> v2:
>  - Restrict probing to interface #3 only
>  - Add a device model to commit message
>  - Fix grammar in commit message
>  - Add Link: to v1

Now applied, thanks.

Johan