1 files changed, 74 insertions, 20 deletions

diff --git a/drivers/usb/serial/qcserial.c b/drivers/usb/serial/qcserial.c
index 5022fcfa0260..9919d2a9faf2 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;
@@ -181,6 +215,10 @@ static int qcprobe(struct usb_serial *serial, const struct usb_device_id *id)
         int altsetting = -1;
         bool sendsetup = false;
 
+        /* we only support vendor specific functions */
+        if (intf->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC)
+                goto done;
+
         nintf = serial->dev->actconfig->desc.bNumInterfaces;
         dev_dbg(dev, "Num Interfaces = %d\n", nintf);
         ifnum = intf->desc.bInterfaceNumber;
@@ -240,6 +278,12 @@ 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
@@ -301,29 +345,39 @@ static int qcprobe(struct usb_serial *serial, const struct usb_device_id *id)
                 break;
         case QCSERIAL_HWI:
                 /*
-                 * Huawei layout:
-                 * 0: AT-capable modem port
-                 * 1: DM/DIAG
-                 * 2: AT-capable modem port
-                 * 3: CCID-compatible PCSC interface
-                 * 4: QMI/net
-                 * 5: NMEA
+                 * Huawei devices map functions by subclass + protocol
+                 * instead of interface numbers. The protocol identify
+                 * a specific function, while the subclass indicate a
+                 * specific firmware source
+                 *
+                 * This is a blacklist of functions known to be
+                 * non-serial.  The rest are assumed to be serial and
+                 * will be handled by this driver
                  */
-                switch (ifnum) {
-                case 0:
-                case 2:
-                        dev_dbg(dev, "Modem port found\n");
-                        break;
-                case 1:
-                        dev_dbg(dev, "DM/DIAG interface found\n");
-                        break;
-                case 5:
-                        dev_dbg(dev, "NMEA GPS interface found\n");
-                        break;
-                default:
-                        /* don't claim any unsupported interface */
+                switch (intf->desc.bInterfaceProtocol) {
+                        /* QMI combined (qmi_wwan) */
+                case 0x07:
+                case 0x37:
+                case 0x67:
+                        /* QMI data (qmi_wwan) */
+                case 0x08:
+                case 0x38:
+                case 0x68:
+                        /* QMI control (qmi_wwan) */
+                case 0x09:
+                case 0x39:
+                case 0x69:
+                        /* NCM like (huawei_cdc_ncm) */
+                case 0x16:
+                case 0x46:
+                case 0x76:
                         altsetting = -1;
                         break;
+                default:
+                        dev_dbg(dev, "Huawei type serial port found (%02x/%02x/%02x)\n",
+                                intf->desc.bInterfaceClass,
+                                intf->desc.bInterfaceSubClass,
+                                intf->desc.bInterfaceProtocol);
                 }
                 break;
         default: