[PATCH 3.12 070/142] USB: qcserial: Add support for Quectel EC20 Mini PCIe module

From: Jiri Slaby
Date: Mon Apr 10 2017 - 11:53:43 EST


From: Petr Åtetiar <ynezz@xxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit 9d5b5ed796d7afd7e8d2ac4b4fb77c6a49463f4b upstream.

It seems like this device has same vendor and product IDs as G2K
devices, but it has different number of interfaces(4 vs 5) and also
different interface layout which makes it currently unusable:

usbcore: registered new interface driver qcserial
usbserial: USB Serial support registered for Qualcomm USB modem
usb 2-1.2: unknown number of interfaces: 5

lsusb output:

Bus 002 Device 003: ID 05c6:9215 Qualcomm, Inc. Acer Gobi 2000 Wireless
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x05c6 Qualcomm, Inc.
idProduct 0x9215 Acer Gobi 2000 Wireless Modem
bcdDevice 2.32
iManufacturer 1 Quectel
iProduct 2 Quectel LTE Module
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 209
bNumInterfaces 5
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xa0
(Bus Powered)
Remote Wakeup
MaxPower 500mA

Signed-off-by: Petr Åtetiar <ynezz@xxxxxxx>
[johan: rename define and add comment ]
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/usb/serial/qcserial.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)

diff --git a/drivers/usb/serial/qcserial.c b/drivers/usb/serial/qcserial.c
index 9792bfa17f74..2c9a44523991 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 */
@@ -166,6 +168,38 @@ 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;
@@ -241,6 +275,12 @@ 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
--
2.12.2