The Compal EXM-G1x is a Qualcomm SDX12-based LTE modem. Add support for
its vendor-specific serial interfaces with protocols 0x30, 0x40, and
0x60.

Relevant output from usb-devices:

T:  Bus=04 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  4 Spd=5000 MxCh= 0
D:  Ver= 3.20 Cls=ef(misc ) Sub=02 Prot=01 MxPS= 9 #Cfgs=  1
P:  Vendor=04b7 ProdID=8217 Rev=05.04
S:  Manufacturer=COMPAL
S:  Product=EXM-G1x
C:  #Ifs= 6 Cfg#= 1 Atr=a0 MxPwr=896mA
I:  If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=30 Driver=option
I:  If#= 1 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=42 Prot=01 Driver=(none)
I:  If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=60 Driver=option
I:  If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=40 Driver=option
I:  If#= 4 Alt= 0 #EPs= 1 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
I:  If#= 8 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=50 Driver=qmi_wwan

Tested on a Compal EXM-G1x modem.

Assisted-by: Codex:GPT-5
Signed-off-by: Ian Lin <jisayme@gmail.com>
---
v3:
  - base on usb-next
  - add AI assistance attribution
  - post as a fresh thread
v2: https://lore.kernel.org/20260828082645.13018-1-jisayme@gmail.com/
  - split USB serial support into a separate patch
  - identify the Qualcomm SDX12 chipset and include usb-devices output
  - keep the device entries sorted and add the product name
v1: https://lore.kernel.org/20260828075644.6228-1-jisayme@gmail.com/

 drivers/usb/serial/option.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c
index fd8f96294..8713f8b93 100644
--- a/drivers/usb/serial/option.c
+++ b/drivers/usb/serial/option.c
@@ -2541,6 +2541,9 @@ static const struct usb_device_id option_ids[] = {
 	{ USB_DEVICE_AND_INTERFACE_INFO(UNISOC_VENDOR_ID, TOZED_PRODUCT_LT70C, 0xff, 0, 0) },
 	{ USB_DEVICE_AND_INTERFACE_INFO(UNISOC_VENDOR_ID, UNISOC_PRODUCT_UIS7720, 0xff, 0, 0) },
 	{ USB_DEVICE_AND_INTERFACE_INFO(UNISOC_VENDOR_ID, LUAT_PRODUCT_AIR720U, 0xff, 0, 0) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(0x04b7, 0x8217, 0xff, 0xff, 0x30) },	/* Compal EXM-G1x */
+	{ USB_DEVICE_AND_INTERFACE_INFO(0x04b7, 0x8217, 0xff, 0xff, 0x40) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(0x04b7, 0x8217, 0xff, 0xff, 0x60) },
 	{ USB_DEVICE_INTERFACE_CLASS(0x1bbb, 0x0530, 0xff),			/* TCL IK512 MBIM */
 	  .driver_info = NCTRL(1) },
 	{ USB_DEVICE_INTERFACE_CLASS(0x1bbb, 0x0640, 0xff),			/* TCL IK512 ECM */

base-commit: 15734de99517b0c81a1a5a3bccaff4593ef8d953
-- 
2.43.0

On Mon, Aug 31, 2026 at 04:44:05PM +0800, Ian Lin wrote:
> The Compal EXM-G1x is a Qualcomm SDX12-based LTE modem. Add support for
> its vendor-specific serial interfaces with protocols 0x30, 0x40, and
> 0x60.
> 
> Relevant output from usb-devices:
> 
> T:  Bus=04 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  4 Spd=5000 MxCh= 0
> D:  Ver= 3.20 Cls=ef(misc ) Sub=02 Prot=01 MxPS= 9 #Cfgs=  1
> P:  Vendor=04b7 ProdID=8217 Rev=05.04
> S:  Manufacturer=COMPAL
> S:  Product=EXM-G1x
> C:  #Ifs= 6 Cfg#= 1 Atr=a0 MxPwr=896mA
> I:  If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=30 Driver=option
> I:  If#= 1 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=42 Prot=01 Driver=(none)
> I:  If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=60 Driver=option
> I:  If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=40 Driver=option
> I:  If#= 4 Alt= 0 #EPs= 1 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
> I:  If#= 8 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=50 Driver=qmi_wwan
> 
> Tested on a Compal EXM-G1x modem.
> 
> Assisted-by: Codex:GPT-5
> Signed-off-by: Ian Lin <jisayme@gmail.com>
> ---
> v3:
>   - base on usb-next
>   - add AI assistance attribution
>   - post as a fresh thread
> v2: https://lore.kernel.org/20260828082645.13018-1-jisayme@gmail.com/
>   - split USB serial support into a separate patch
>   - identify the Qualcomm SDX12 chipset and include usb-devices output
>   - keep the device entries sorted and add the product name
> v1: https://lore.kernel.org/20260828075644.6228-1-jisayme@gmail.com/

Thanks for the update, now applied.

Johan