MT7620原生SDK支持HUAWEI 4G dongle -- 2

从linux-3.10.11移植qmi_wwan.c到MT7620原生SDK使用的linux-2.6.36.x

该驱动对应使用 Qualcomm MSM Interface (QMI)的2G/4G dongle，源码中解释如下：

/* 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
 *
 * Alternatively, control and data functions can be combined in a
 * single USB interface.
 *
 * Handling a protocol like QMI is out of the scope for any driver.
 * It is exported as a character device using the cdc-wdm driver as
 * a subdriver, enabling userspace applications ("modem managers") to
 * handle it.
 *
 * These devices may alternatively/additionally be configured using AT
 * commands on a serial interface
 */

首先拷贝"linux-3.10.11\drivers\net\usb\qmi_wwan.c"到“linux-2.6.36.x\drivers\net\usb\”目录，以及修改该目录的makefile，kconfig；编译时会有错误，需要在做一些工作，其中的一部分如下所示：

1）修改“linux-2.6.36.x\include\linux\mod_devicetable.h” 增加“__u8        bInterfaceNumber;”


/**
 * struct usb_device_id - identifies USB devices for probing and hotplugging
 * @match_flags: Bit mask controlling of the other fields are used to match
 *  against new devices.  Any field except for driver_info may be used,
 *  although some only make sense in conjunction with other fields.
 *  This is usually set by a USB_DEVICE_*() macro, which sets all
 *  other fields in this structure except for driver_info.
 * @idVendor: USB vendor ID for a device; numbers are assigned
 *  by the USB forum to its members.
 * @idProduct: Vendor-assigned product ID.
 * @bcdDevice_lo: Low end of range of vendor-assigned product version numbers.
 *  This is also used to identify individual product versions, for
 *  a range consisting of a single device.
 * @bcdDevice_hi: High end of version number range.  The range of product
 *  versions is inclusive.
 * @bDeviceClass: Class of device; numbers are assigned
 *  by the USB forum.  Products may choose to implement classes,
 *  or be vendor-specific.  Device classes specify behavior of all
 *  the interfaces on a devices.
 * @bDeviceSubClass: Subclass of device; associated with bDeviceClass.
 * @bDeviceProtocol: Protocol of device; associated with bDeviceClass.
 * @bInterfaceClass: Class of interface; numbers are assigned
 *  by the USB forum.  Products may choose to implement classes,
 *  or be vendor-specific.  Interface classes specify behavior only
 *  of a given interface; other interfaces may support other classes.
 * @bInterfaceSubClass: Subclass of interface; associated with bInterfaceClass.
 * @bInterfaceProtocol: Protocol of interface; associated with bInterfaceClass.
 * @bInterfaceNumber: Number of interface; composite devices may use
 *  fixed interface numbers to differentiate between vendor-specific
 *  interfaces.
 * @driver_info: Holds information used by the driver.  Usually it holds
 *  a pointer to a descriptor understood by the driver, or perhaps
 *  device flags.
 *
 * In most cases, drivers will create a table of device IDs by using
 * USB_DEVICE(), or similar macros designed for that purpose.
 * They will then export it to userspace using MODULE_DEVICE_TABLE(),
 * and provide it to the USB core through their usb_driver structure.
 *
 * See the usb_match_id() function for information about how matches are
 * performed.  Briefly, you will normally use one of several macros to help
 * construct these entries.  Each entry you provide will either identify
 * one or more specific products, or will identify a class of products
 * which have agreed to behave the same.  You should put the more specific
 * matches towards the beginning of your table, so that driver_info can
 * record quirks of specific products.
 */
struct usb_device_id {
    /* which fields to match against? */
    __u16       match_flags;


    /* Used for product specific matches; range is inclusive */
    __u16       idVendor;
    __u16       idProduct;
    __u16       bcdDevice_lo;
    __u16       bcdDevice_hi;


    /* Used for device class matches */
    __u8        bDeviceClass;
    __u8        bDeviceSubClass;
    __u8        bDeviceProtocol;


    /* Used for interface class matches */
    __u8        bInterfaceClass;
    __u8        bInterfaceSubClass;
    __u8        bInterfaceProtocol;


    /* Used for vendor-specific interface matches */
    __u8        bInterfaceNumber;


    /* not matched against */
    kernel_ulong_t  driver_info
        __attribute__((aligned(sizeof(kernel_ulong_t))));
};




2）拷贝“linux-3.10.11\include\uapi\linux\usb\cdc-wdm.h”到“linux-2.6.36.x\include\uapi\linux\usb\”目录


3）
drivers/net/usb/qmi_wwan.c: In function `qmi_wwan_mac_addr':
drivers/net/usb/qmi_wwan.c:127: error: implicit declaration of function `eth_prepare_mac_addr_change'
drivers/net/usb/qmi_wwan.c:132: error: implicit declaration of function `eth_commit_mac_addr_change'
drivers/net/usb/qmi_wwan.c: In function `qmi_wwan_bind':
drivers/net/usb/qmi_wwan.c:327: error: implicit declaration of function `eth_hw_addr_random'


解决上面的错误，修改linux-2.6.36.x\net\ethernet\eth.c
linux-2.6.36.x\include\linux\etherdevice.h

根据linux-3.10.11对应修改。尽量只解决编译问题，不引起太大的改动。例如“alloc_etherdev_mq”函数涉及到的地方比较多，尽量保持linux-2.6.36.x中的定义。




4）
error: unknown field `disable_hub_initiated_lpm' specified in initializer


修改 “linux-2.6.36.x\include\linux\usb.h”中“struct usb_driver”，增加“unsigned int disable_hub_initiated_lpm:1;”
struct usb_driver {
    const char *name;


    int (*probe) (struct usb_interface *intf,
              const struct usb_device_id *id);


    void (*disconnect) (struct usb_interface *intf);


    int (*unlocked_ioctl) (struct usb_interface *intf, unsigned int code,
            void *buf);


    int (*suspend) (struct usb_interface *intf, pm_message_t message);
    int (*resume) (struct usb_interface *intf);
    int (*reset_resume)(struct usb_interface *intf);


    int (*pre_reset)(struct usb_interface *intf);
    int (*post_reset)(struct usb_interface *intf);


    const struct usb_device_id *id_table;


    struct usb_dynids dynids;
    struct usbdrv_wrap drvwrap;
    unsigned int no_dynamic_id:1;
    unsigned int supports_autosuspend:1;
    unsigned int disable_hub_initiated_lpm:1;
    unsigned int soft_unbind:1;
};




5）
  CC      net/ethernet/eth.o
net/ethernet/eth.c: In function `eth_prepare_mac_addr_change':
net/ethernet/eth.c:282: error: `IFF_LIVE_ADDR_CHANGE' undeclared (first use in this function)


找到如下定义，添加到eth.c中
#define IFF_LIVE_ADDR_CHANGE 0x100000 /* device supports hardware address
* change when it's running */

总之，遇到编译错误，就从linux-3.10.11中将相关代码移植到linux 2.6.36； 

最终是可以编译过的，不过手上没有相应的dongle，无法验证工作是否OK。