1 files changed, 40 insertions, 0 deletions

diff --git a/drivers/usb/serial/qcserial.c b/drivers/usb/serial/qcserial.c
index 5022fcfa0260..0e46af0d0cb4 100644
--- a/drivers/usb/serial/qcserial.c
+++ b/drivers/usb/serial/qcserial.c
@@ -22,6 +22,8 @@
 #define DRIVER_AUTHOR "Qualcomm Inc"
 #define DRIVER_DESC "Qualcomm USB Serial driver"
 
+#define QUECTEL_EC20_PID        0x9215
+
 /* standard device layouts supported by this driver */
 enum qcserial_layouts {
         QCSERIAL_G2K = 0,       /* Gobi 2000 */
@@ -171,6 +173,38 @@ static const struct usb_device_id id_table[] = {
 };
 MODULE_DEVICE_TABLE(usb, id_table);
 
+static int handle_quectel_ec20(struct device *dev, int ifnum)
+{
+        int altsetting = 0;
+
+        /*
+         * Quectel EC20 Mini PCIe LTE module layout:
+         * 0: DM/DIAG (use libqcdm from ModemManager for communication)
+         * 1: NMEA
+         * 2: AT-capable modem port
+         * 3: Modem interface
+         * 4: NDIS
+         */
+        switch (ifnum) {
+        case 0:
+                dev_dbg(dev, "Quectel EC20 DM/DIAG interface found\n");
+                break;
+        case 1:
+                dev_dbg(dev, "Quectel EC20 NMEA GPS interface found\n");
+                break;
+        case 2:
+        case 3:
+                dev_dbg(dev, "Quectel EC20 Modem port found\n");
+                break;
+        case 4:
+                /* Don't claim the QMI/net interface */
+                altsetting = -1;
+                break;
+        }
+
+        return altsetting;
+}
+
 static int qcprobe(struct usb_serial *serial, const struct usb_device_id *id)
 {
         struct usb_host_interface *intf = serial->interface->cur_altsetting;
@@ -240,6 +274,12 @@ static int qcprobe(struct usb_serial *serial, const struct usb_device_id *id)
                         altsetting = -1;
                 break;
         case QCSERIAL_G2K:
+                /* handle non-standard layouts */
+                if (nintf == 5 && id->idProduct == QUECTEL_EC20_PID) {
+                        altsetting = handle_quectel_ec20(dev, ifnum);
+                        goto done;
+                }
+
                 /*
                  * Gobi 2K+ USB layout:
                  * 0: QMI/net