3 files changed, 251 insertions, 0 deletions

diff --git a/drivers/net/usb/Kconfig b/drivers/net/usb/Kconfig
index 233576127934..4bad899fb38f 100644
--- a/drivers/net/usb/Kconfig
+++ b/drivers/net/usb/Kconfig
@@ -398,6 +398,27 @@ config USB_NET_KALMIA
           To compile this driver as a module, choose M here: the
           module will be called kalmia.
 
+config USB_NET_QMI_WWAN
+        tristate "QMI WWAN driver for Qualcomm MSM based 3G and LTE modems"
+        depends on USB_USBNET
+        help
+          Support WWAN LTE/3G devices based on Qualcomm Mobile Data Modem
+          (MDM) chipsets.  Examples of such devices are
+            * Huawei E392/E398
+
+          This driver will only drive the ethernet part of the chips.
+          The devices require additional configuration to be usable.
+          Multiple management interfaces with linux drivers are
+          available:
+
+            * option: AT commands on /dev/ttyUSBx
+            * cdc-wdm: Qualcomm MSM Interface (QMI) protocol on /dev/cdc-wdmx
+
+          A modem manager with support for QMI is recommended.
+
+          To compile this driver as a module, choose M here: the
+          module will be called qmi_wwan.
+
 config USB_HSO
         tristate "Option USB High Speed Mobile Devices"
         depends on USB && RFKILL
@@ -461,4 +482,5 @@ config USB_VL600
 
           http://ubuntuforums.org/showpost.php?p=10589647&postcount=17
 
+
 endmenu
diff --git a/drivers/net/usb/Makefile b/drivers/net/usb/Makefile
index c203fa21f6b1..a2e2d72c52a0 100644
--- a/drivers/net/usb/Makefile
+++ b/drivers/net/usb/Makefile
@@ -29,4 +29,5 @@ obj-$(CONFIG_USB_SIERRA_NET)	+= sierra_net.o
 obj-$(CONFIG_USB_NET_CX82310_ETH)       += cx82310_eth.o
 obj-$(CONFIG_USB_NET_CDC_NCM)   += cdc_ncm.o
 obj-$(CONFIG_USB_VL600)         += lg-vl600.o
+obj-$(CONFIG_USB_NET_QMI_WWAN)  += qmi_wwan.o
 
diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
new file mode 100644
index 000000000000..739e6de7abcb
--- /dev/null
+++ b/drivers/net/usb/qmi_wwan.c
@@ -0,0 +1,228 @@
+/*
+ * Copyright (c) 2012  Bjørn Mork <bjorn@mork.no>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/ethtool.h>
+#include <linux/mii.h>
+#include <linux/usb.h>
+#include <linux/usb/cdc.h>
+#include <linux/usb/usbnet.h>
+
+/* The name of the CDC Device Management driver */
+#define DM_DRIVER "cdc_wdm"
+
+/*
+ * This driver supports wwan (3G/LTE/?) devices using a vendor
+ * specific management protocol called Qualcomm MSM Interface (QMI) -
+ * in addition to the more common AT commands over serial interface
+ * management
+ *
+ * QMI is wrapped in CDC, using CDC encapsulated commands on the
+ * control ("master") interface of a two-interface CDC Union
+ * resembling standard CDC ECM.  The devices do not use the control
+ * interface for any other CDC messages.  Most likely because the
+ * management protocol is used in place of the standard CDC
+ * notifications NOTIFY_NETWORK_CONNECTION and NOTIFY_SPEED_CHANGE
+ *
+ * Handling a protocol like QMI is out of the scope for any driver.
+ * It can be exported as a character device using the cdc-wdm driver,
+ * which will enable userspace applications ("modem managers") to
+ * handle it.  This may be required to use the network interface
+ * provided by the driver.
+ *
+ * These devices may alternatively/additionally be configured using AT
+ * commands on any of the serial interfaces driven by the option driver
+ *
+ * This driver binds only to the data ("slave") interface to enable
+ * the cdc-wdm driver to bind to the control interface.  It still
+ * parses the CDC functional descriptors on the control interface to
+ *  a) verify that this is indeed a handled interface (CDC Union
+ *     header lists it as slave)
+ *  b) get MAC address and other ethernet config from the CDC Ethernet
+ *     header
+ *  c) enable user bind requests against the control interface, which
+ *     is the common way to bind to CDC Ethernet Control Model type
+ *     interfaces
+ *  d) provide a hint to the user about which interface is the
+ *     corresponding management interface
+ */
+
+static int qmi_wwan_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+        int status = -1;
+        struct usb_interface *control = NULL;
+        u8 *buf = intf->cur_altsetting->extra;
+        int len = intf->cur_altsetting->extralen;
+        struct usb_interface_descriptor *desc = &intf->cur_altsetting->desc;
+        struct usb_cdc_union_desc *cdc_union = NULL;
+        struct usb_cdc_ether_desc *cdc_ether = NULL;
+        u32 required = 1 << USB_CDC_HEADER_TYPE | 1 << USB_CDC_UNION_TYPE;
+        u32 found = 0;
+
+        /*
+         * assume a data interface has no additional descriptors and
+         * that the control and data interface are numbered
+         * consecutively - this holds for the Huawei device at least
+         */
+        if (len == 0 && desc->bInterfaceNumber > 0) {
+                control = usb_ifnum_to_if(dev->udev, desc->bInterfaceNumber - 1);
+                if (!control)
+                        goto err;
+
+                buf = control->cur_altsetting->extra;
+                len = control->cur_altsetting->extralen;
+                dev_dbg(&intf->dev, "guessing \"control\" => %s, \"data\" => this\n",
+                        dev_name(&control->dev));
+        }
+
+        while (len > 3) {
+                struct usb_descriptor_header *h = (void *)buf;
+
+                /* ignore any misplaced descriptors */
+                if (h->bDescriptorType != USB_DT_CS_INTERFACE)
+                        goto next_desc;
+
+                /* buf[2] is CDC descriptor subtype */
+                switch (buf[2]) {
+                case USB_CDC_HEADER_TYPE:
+                        if (found & 1 << USB_CDC_HEADER_TYPE) {
+                                dev_dbg(&intf->dev, "extra CDC header\n");
+                                goto err;
+                        }
+                        if (h->bLength != sizeof(struct usb_cdc_header_desc)) {
+                                dev_dbg(&intf->dev, "CDC header len %u\n", h->bLength);
+                                goto err;
+                        }
+                        break;
+                case USB_CDC_UNION_TYPE:
+                        if (found & 1 << USB_CDC_UNION_TYPE) {
+                                dev_dbg(&intf->dev, "extra CDC union\n");
+                                goto err;
+                        }
+                        if (h->bLength != sizeof(struct usb_cdc_union_desc)) {
+                                dev_dbg(&intf->dev, "CDC union len %u\n", h->bLength);
+                                goto err;
+                        }
+                        cdc_union = (struct usb_cdc_union_desc *)buf;
+                        break;
+                case USB_CDC_ETHERNET_TYPE:
+                        if (found & 1 << USB_CDC_ETHERNET_TYPE) {
+                                dev_dbg(&intf->dev, "extra CDC ether\n");
+                                goto err;
+                        }
+                        if (h->bLength != sizeof(struct usb_cdc_ether_desc)) {
+                                dev_dbg(&intf->dev, "CDC ether len %u\n",  h->bLength);
+                                goto err;
+                        }
+                        cdc_ether = (struct usb_cdc_ether_desc *)buf;
+                        break;
+                }
+
+                /*
+                 * Remember which CDC functional descriptors we've seen.  Works
+                 * for all types we care about, of which USB_CDC_ETHERNET_TYPE
+                 * (0x0f) is the highest numbered
+                 */
+                if (buf[2] < 32)
+                        found |= 1 << buf[2];
+
+next_desc:
+                len -= h->bLength;
+                buf += h->bLength;
+        }
+
+        /* did we find all the required ones? */
+        if ((found & required) != required) {
+                dev_err(&intf->dev, "CDC functional descriptors missing\n");
+                goto err;
+        }
+
+        /* give the user a helpful hint if trying to bind to the wrong interface */
+        if (cdc_union && desc->bInterfaceNumber == cdc_union->bMasterInterface0) {
+                dev_err(&intf->dev, "leaving \"control\" interface for " DM_DRIVER " - try binding to %s instead!\n",
+                        dev_name(&usb_ifnum_to_if(dev->udev, cdc_union->bSlaveInterface0)->dev));
+                goto err;
+        }
+
+        /* errors aren't fatal - we can live with the dynamic address */
+        if (cdc_ether) {
+                dev->hard_mtu = le16_to_cpu(cdc_ether->wMaxSegmentSize);
+                usbnet_get_ethernet_addr(dev, cdc_ether->iMACAddress);
+        }
+
+        /* success! point the user to the management interface */
+        if (control)
+                dev_info(&intf->dev, "Use \"" DM_DRIVER "\" for QMI interface %s\n",
+                        dev_name(&control->dev));
+
+        /* XXX: add a sysfs symlink somewhere to help management applications find it? */
+
+        /* collect bulk endpoints now that we know intf == "data" interface */
+        status = usbnet_get_endpoints(dev, intf);
+
+err:
+        return status;
+}
+
+/* stolen from cdc_ether.c */
+static int qmi_wwan_manage_power(struct usbnet *dev, int on)
+{
+        dev->intf->needs_remote_wakeup = on;
+        return 0;
+}
+
+static const struct driver_info qmi_wwan_info = {
+        .description    = "QMI speaking wwan device",
+        .flags          = FLAG_WWAN,
+        .bind           = qmi_wwan_bind,
+        .manage_power   = qmi_wwan_manage_power,
+};
+
+#define HUAWEI_VENDOR_ID        0x12D1
+
+static const struct usb_device_id products[] = {
+{
+        /* Huawei E392, E398 and possibly others sharing both device id and more... */
+        .match_flags        = USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_INT_INFO,
+        .idVendor           = HUAWEI_VENDOR_ID,
+        .bInterfaceClass    = USB_CLASS_VENDOR_SPEC,
+        .bInterfaceSubClass = 1,
+        .bInterfaceProtocol = 8, /* NOTE: This is the *slave* interface of the CDC Union! */
+        .driver_info        = (unsigned long)&qmi_wwan_info,
+}, {
+},      /* END */
+};
+MODULE_DEVICE_TABLE(usb, products);
+
+static struct usb_driver qmi_wwan_driver = {
+        .name                 = "qmi_wwan",
+        .id_table             = products,
+        .probe                = usbnet_probe,
+        .disconnect           = usbnet_disconnect,
+        .suspend              = usbnet_suspend,
+        .resume               = usbnet_resume,
+        .reset_resume         = usbnet_resume,
+        .supports_autosuspend = 1,
+};
+
+static int __init qmi_wwan_init(void)
+{
+        return usb_register(&qmi_wwan_driver);
+}
+module_init(qmi_wwan_init);
+
+static void __exit qmi_wwan_exit(void)
+{
+        usb_deregister(&qmi_wwan_driver);
+}
+module_exit(qmi_wwan_exit);
+
+MODULE_AUTHOR("Bjørn Mork <bjorn@mork.no>");
+MODULE_DESCRIPTION("Qualcomm MSM Interface (QMI) WWAN driver");
+MODULE_LICENSE("GPL");