MT7628移植移远EC20驱动实现4G上网功能（绝大多数使用openwrt的设备通用）
我的上一篇文章中完成对MT7628固件的编译，本文是在固件编译通过的基础上移植EC20驱动的，固件编译问题请参考上文。
在讲解之前先介绍移远的EC20模块，该模块是目前较为成熟的4G模块，可向安装了Windows、Linux等设备的机器提供4G上网服务，移远同类产品中还有AG35模块，这个模块我之前在AM4378上移植过，当时花费了好多时间才移植成功，其实移远产品做得也不错，同类的模块移植方法基本是一样的。
废话不多说，下面开始讲述EC20驱动在MT7628上的移植过程。
第一步：
修改源码（注意：固件必须要先编译过一轮，否则没有build_dir目录）。此步骤必须细心修改，并认真核对。以下路径中的源文件均需要修改才能使用：
/home/user/openwrt-sdk/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7628/linux-3.10.14/drivers/usb/serial/option.c
//大概在532行，添加如下代码
......
static const struct usb_device_id option_ids[] = {
#if 1 //Added by Quectel
{ USB_DEVICE(0x05C6, 0x9090) }, /* Quectel UC15 */
{ USB_DEVICE(0x05C6, 0x9003) }, /* Quectel UC20 */
{ USB_DEVICE(0x2C7C, 0x0125) }, /* Quectel EC25/EC20 R2.0 */
{ USB_DEVICE(0x2C7C, 0x0121) }, /* Quectel EC21 */
{ USB_DEVICE(0x05C6, 0x9215) }, /* Quectel EC20 */
{ USB_DEVICE(0x2C7C, 0x0191) }, /* Quectel EG91 */
{ USB_DEVICE(0x2C7C, 0x0195) }, /* Quectel EG95 */
{ USB_DEVICE(0x2C7C, 0x0306) }, /* Quectel EG06/EP06/EM06 */
{ USB_DEVICE(0x2C7C, 0x0296) }, /* Quectel BG96 */
#endif
{ USB_DEVICE(OPTION_VENDOR_ID, OPTION_PRODUCT_COLT) },
{ USB_DEVICE(OPTION_VENDOR_ID, OPTION_PRODUCT_RICOLA) },
......//大概在1390行，插入以下代码
......
#ifdef CONFIG_PM
.suspend = usb_wwan_suspend,
.resume = usb_wwan_resume,
#if 1 //Added by Quectel
.reset_resume = usb_wwan_resume,
#endif
#endif
......//在大约1459行，插入以下代码
......
if (dev_desc->idVendor == cpu_to_le16(SAMSUNG_VENDOR_ID) &&
dev_desc->idProduct == cpu_to_le16(SAMSUNG_PRODUCT_GT_B3730) &&
iface_desc->bInterfaceClass != USB_CLASS_CDC_DATA)
return -ENODEV;
#if 1 //Added by Quectel
//Quectel UC20's interface 4 can be used as USB Network device
if (serial->dev->descriptor.idVendor == cpu_to_le16(0x05C6) &&
serial->dev->descriptor.idProduct == cpu_to_le16(0x9003)
&& serial->interface->cur_altsetting->desc.bInterfaceNumber >= 4)return -ENODEV;
//Quectel EC20's interface 4 can be used as USB Network device
if (serial->dev->descriptor.idVendor == cpu_to_le16(0x05C6) &&
serial->dev->descriptor.idProduct == cpu_to_le16(0x9215)
&& serial->interface->cur_altsetting->desc.bInterfaceNumber >= 4)
return -ENODEV;
//Quectel EC25&EC21&EC20 R2.0&EG91&EG95&EG06&EP06&EM06&BG96's interface 4 can be
//used as USB Network device
if (serial->dev->descriptor.idVendor == cpu_to_le16(0x2C7C)
&& serial->interface->cur_altsetting->desc.bInterfaceNumber >= 4)
return -ENODEV;
#endif
/* Store device id so we can use it during attach. */
usb_set_serial_data(serial, (void *)id);
....../home/user/openwrt-sdk/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7628/linux-3.10.14/drivers/usb/serial/qcserial.c
//大概在81行，注释以下代码
//{USB_DEVICE(0x05c6, 0x9215)}, /* Acer Gobi 2000 Modem device (VP413) *//home/user/openwrt-sdk/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7628/linux-3.10.14/drivers/net/usb/qmi_wwan.c
//大概在617行，注释以下代码
//{QMI_GOBI_DEVICE(0x05c6, 0x9215)}, /* Acer Gobi 2000 Modem device (VP413) *///在大概436行，插入以下代码
......
static const struct usb_device_id products[] = {
#if 1 //Added by Quectel
#ifndef QMI_FIXED_INTF
/* map QMI/wwan function by a fixed interface number */
#define QMI_FIXED_INTF(vend, prod, num) \
.match_flags = USB_DEVICE_ID_MATCH_DEVICE |
USB_DEVICE_ID_MATCH_INT_INFO, \
.idVendor = vend, \
.idProduct = prod, \
.bInterfaceClass = 0xff, \
.bInterfaceSubClass = 0xff, \
.bInterfaceProtocol = 0xff, \
.driver_info = (unsigned long)&qmi_wwan_force_int##num,
#endif
{ QMI_FIXED_INTF(0x05C6, 0x9003, 4) }, /* Quectel UC20 */
{ QMI_FIXED_INTF(0x2C7C, 0x0125, 4) }, /* Quectel EC25/EC20 R2.0 */
{ QMI_FIXED_INTF(0x2C7C, 0x0121, 4) }, /* Quectel EC21 */
{ QMI_FIXED_INTF(0x05C6, 0x9215, 4) }, /* Quectel EC20 */
{ QMI_FIXED_INTF(0x2C7C, 0x0191, 4) }, /* Quectel EG91 */
{ QMI_FIXED_INTF(0x2C7C, 0x0195, 4) }, /* Quectel EG95 */
{ QMI_FIXED_INTF(0x2C7C, 0x0306, 4) }, /* Quectel EG06/EP06/EM06 */
{ QMI_FIXED_INTF(0x2C7C, 0x0296, 4) }, /* Quectel BG96 */
#endif
......//在文件的开头处插入如下代码
......
#include
#include
#if 1 //Added by Quectel
#include
struct sk_buff *qmi_wwan_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
{
if (dev->udev->descriptor.idVendor != cpu_to_le16(0x2C7C))
return skb;
// Skip Ethernet header from message
if (skb_pull(skb, ETH_HLEN)) {
return skb;
} else {
dev_err(&dev->intf->dev, "Packet Dropped ");
}
// Filter the packet out, release it
dev_kfree_skb_any(skb);
return NULL;
}
#include
#if (LINUX_VERSION_CODE < KERNEL_VERSION( 3,9,1 ))
static int qmi_wwan_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
{
__be16 proto;
if (dev->udev->descriptor.idVendor != cpu_to_le16(0x2C7C))
return 1;/* This check is no longer done by usbnet */
if (skb->len < dev->net->hard_header_len)
return 0;
switch (skb->data[0] & 0xf0) {
case 0x40:
proto = htons(ETH_P_IP);
break;
case 0x60:
proto = htons(ETH_P_IPV6);
break;
case 0x00:
if (is_multicast_ether_addr(skb->data))
return 1;
/* possibly bogus destination - rewrite just in case */
skb_reset_mac_header(skb);
goto fix_dest;
default:
/* pass along other packets without modifications */
return 1;
}
if (skb_headroom(skb) < ETH_HLEN)
return 0;
skb_push(skb, ETH_HLEN);
skb_reset_mac_header(skb);
eth_hdr(skb)->h_proto = proto;
memset(eth_hdr(skb)->h_source, 0, ETH_ALEN);
fix_dest:
memcpy(eth_hdr(skb)->h_dest, dev->net->dev_addr, ETH_ALEN);
return 1;
}
/* very simplistic detection of IPv4 or IPv6 headers */
static bool possibly_iphdr(const char *data)
{
return (data[0] & 0xd0) == 0x40;
}
#endif
#endif
...... //在大概395行，插入如下代码
......
#if 1 //Added by Quectel
if (dev->udev->descriptor.idVendor == cpu_to_le16(0x2C7C)) {
dev_info(&intf->dev, "Quectel EC25&EC21&EC20 R2.0&EG91&EG95&EG06&EP06&EM06&BG96 work on RawIP mode\n");
dev->net->flags |= IFF_NOARP;
#if (LINUX_VERSION_CODE < KERNEL_VERSION( 3,9,1 ))
/* make MAC addr easily distinguishable from an IP header */
if (possibly_iphdr(dev->net->dev_addr)) {
dev->net->dev_addr[0] |= 0x02; /* set local assignment bit */
dev->net->dev_addr[0] &= 0xbf; /* clear "IP" bit */
}
#endif
usb_control_msg(
interface_to_usbdev(intf),
usb_sndctrlpipe(interface_to_usbdev(intf), 0),
0x22, //USB_CDC_REQ_SET_CONTROL_LINE_STATE
0x21, //USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE
1, //active CDC DTR
intf->cur_altsetting->desc.bInterfaceNumber,
NULL, 0, 100);
}
#endif
......//在大约504行，插入如下代码
......
static const struct driver_info qmi_wwan_info = {
.description = "WWAN/QMI device",
.flags = FLAG_WWAN,
.bind = qmi_wwan_bind,
.unbind = qmi_wwan_unbind,
.manage_power = qmi_wwan_manage_power,
.rx_fixup = qmi_wwan_rx_fixup,
#if 1 //Added by Quectel
.tx_fixup = qmi_wwan_tx_fixup,
#endif
....../home/lusy/openwrt-sdk/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7628/linux-3.10.14/drivers/usb/serial/usb_wwan.c
//大概在460行，插入如下代码
......
usb_fill_bulk_urb(urb, serial->dev,
usb_sndbulkpipe(serial->dev, endpoint) | dir,
buf, len, callback, ctx);
#if 1 //Added by Quectel for Zero Packet
if (dir == USB_DIR_OUT) {
struct usb_device_descriptor *desc = &serial->dev->descriptor;
if (desc->idVendor == cpu_to_le16(0x05C6) && desc->idProduct == cpu_to_le16(0x9090))
urb->transfer_flags |= URB_ZERO_PACKET;
if (desc->idVendor == cpu_to_le16(0x05C6) && desc->idProduct == cpu_to_le16(0x9003))
urb->transfer_flags |= URB_ZERO_PACKET;
if (desc->idVendor == cpu_to_le16(0x05C6) && desc->idProduct == cpu_to_le16(0x9215))
urb->transfer_flags |= URB_ZERO_PACKET;
if (desc->idVendor == cpu_to_le16(0x2C7C))
urb->transfer_flags |= URB_ZERO_PACKET;
}
#endif
return urb;
......
第二步：
修改配置，在内核中添加一些选项来支持EC20。这里参考了别人的博客，网址如下：https://blog.csdn.net/hunzhangzui9837/article/details/85916965
#make menuconfig
Kernel modules->USB Support
照着图片配置就行。。。
Network->
将以下选项编译进内核，但是我在我的make menuconfig中找不到wwan，先不管它，有就勾上。
wwan
chat
ppp
uqmi
Utilities->
将以下选项编译进内核，同样没找到comgt-ncm，不管它
comgt
comgt-ncm
usb-modeswitch
Luci->
1.Collections
luci
3.Applications
luci-app-multiwan
luci-app-qos
6.Protocols
luci-proto-3g
luci-proto-ppp
全都配置完了，开始编译
#make V=s
没有问题，全部编译成功。
第三步：
将编译好的固件烧入开发板。固件在/home/user/openwrt-sdk/bin/ramips路径下，名称为openwrt-ramips-mt7628-mt7628-squashfs-sysupgrade.bin。
启动开发板，先用
#ifconfig
查看一下当前ip地址，然后将ip地址复制到浏览器打开，即可通过LuCI登录板子进行配置。
选择如上图所示进入固件更新页面，进入如下页面
在这个页面更新固件就可以了。
更新完成后，就可以将EC20通过USB插入开发板了，如果你的驱动移植成功，将会看到如下log：
#cd /dev
查看一下是否有这几个文件。
第四步：
怎么通过4G模块上网。先进入LuCI页面。
如上图，进入接口配置。这里需要添加一个接口，下图已经添加好了，我下面教大家怎么添加。
点击Add new interface，名字自己起一个，选DHCP，选wwan0，如下图所示。
完成后记得修改一下这个接口的防火墙，如下图。
保存退出，最好板子也重启一下。
再次进入板子，输入
#ifconfig
就能看到你新加的接口了，4G网络正常的话这个接口应能获取到IP地址。
#ping www.baidu.com
PING www.baidu.com (183.232.231.172): 56 data bytes
64 bytes from 183.232.231.172: seq=0 ttl=53 time=131.616 ms
64 bytes from 183.232.231.172: seq=1 ttl=53 time=107.725 ms
64 bytes from 183.232.231.172: seq=2 ttl=53 time=112.723 ms
64 bytes from 183.232.231.172: seq=3 ttl=53 time=113.865 ms
OK，大功告成！