http://ask.openluat.com/article/37
本文章介绍了在linux系统下，如何修改usb驱动支持合宙 Air720模块，以及使用Air720进行ppp拨号上网流程 Air720正常启动后，通过USB连接到linux设备上，驱动正常加载后会在/dev/下产...
本文章介绍了在linux系统下，如何修改usb驱动支持合宙 Air720模块，以及使用Air720进行ppp拨号上网流程
Air720正常启动后，通过USB连接到linux设备上，驱动正常加载后会产生如下设备：
一、修改驱动
首先需要对Linux内核驱动做一定的修改，使操作系统能够支持Air720。
1.Add VID add PID
File: [KERNEL]/drivers/usb/serial/option.c
static const struct usb_device_id option_ids[] = {
//+add by airm2m for Air72x
{ USB_DEVICE(0x1286, 0x4e3d) },
//-add by airm2m for Air72x
{ USB_DEVICE(OPTION_VENDOR_ID, OPTION_PRODUCT_COLT) },
{ USB_DEVICE(OPTION_VENDOR_ID, OPTION_PRODUCT_RICOLA) },
{ USB_DEVICE(OPTION_VENDOR_ID, OPTION_PRODUCT_RICOLA_LIGHT) },
{ USB_DEVICE(OPTION_VENDOR_ID, OPTION_PRODUCT_RICOLA_QUAD) },
{ USB_DEVICE(OPTION_VENDOR_ID, OPTION_PRODUCT_RICOLA_QUAD_LIGHT) },
2. Add the Zero Packet Mechanism
⦁For linux Kernel Version newer than 2.6.34：
File: [KERNEL]/drivers/usb/serial/usb_wwan.c
static struct urb *usb_wwan_setup_urb(struct usb_serial_port *port,
int endpoint,
int dir, void *ctx, char *buf, int len,
void (*callback) (struct urb *))
{
struct usb_serial *serial = port->serial;
struct urb *urb;
urb = usb_alloc_urb(0, GFP_KERNEL); /* No ISO */
if (!urb)
return NULL;
usb_fill_bulk_urb(urb, serial->dev,
usb_sndbulkpipe(serial->dev, endpoint) | dir,
buf, len, callback, ctx);
//+add by airm2m for Air72x
if(dir == USB_DIR_OUT){
struct usb_device_descriptor *desc = &serial->dev->descriptor;
if(desc->idVendor == cpu_to_le16(0x1286) && desc->idProduct == cpu_to_le16(0x4e3d))
{
urb->transfer_flags |= URB_ZERO_PACKET;
}
}
//-add by airm2m for Air72x
return urb;
}
⦁For linux Kernel Version older than 2.6.35：
File: [KERNEL]/drivers/usb/serial/option.c
static struct urb *option_setup_urb(struct usb_serial *serial, int endpoint,
int dir, void *ctx, char *buf, int len,
void (*callback)(struct urb *))
{
......
/* Fill URB using supplied data. */
usb_fill_bulk_urb(urb, serial->dev,
usb_sndbulkpipe(serial->dev, endpoint) | dir,
buf, len, callback, ctx);
//+add by airm2m for Air72x
if(dir == USB_DIR_OUT)
{
struct usb_device_descriptor *desc = &serial->dev->descriptor;
if(desc->idVendor == cpu_to_le16(0x1286) && desc->idProduct == cpu_to_le16(0x4e3d))
{
urb->transfer_flags |= URB_ZERO_PACKET;
}
}
//-add by airm2m for Air72x
return urb;
}
3. Add Reset Resume
⦁For linux Kernel Version newer than 3.4：
File: [KERNEL]/drivers/usb/serial/option.c
static struct usb_serial_driver option_1port_device = {
.driver = {
.owner = THIS_MODULE,
.name = "option1",
},
....
#ifdef CONFIG_PM
.suspend = usb_wwan_suspend,
.resume = usb_wwan_resume,//+add by airm2m for Air726 .reset_resume = usb_wwan_resume, //-add by airm2m for Air726
#endif
};
⦁For linux Kernel Version older than 3.5：
File: [kernel]/drivers/usb/serial/usb-serial.c
/* Driver structure we register with the USB core */
static struct usb_driver usb_serial_driver = {
.name ="usbserial",
.probe =usb_serial_probe,
.disconnect =usb_serial_disconnect,
.suspend =usb_serial_suspend,
.resume =usb_serial_resume,
//+add by airm2m for Air72x
.reset_resume = usb_serial_resume,
//-add by airm2m for Air72x
.no_dynamic_id = 1,
};
4. Modify Kernel Configuration
Step 1：
cd <your kernel directory>
Step 2：
make menuconfig
Step 3：Enable CONFIG_USB_SERIAL_OPTION
[*] Device Drivers → [*] USB Support → [*] USB Serial Converter support → [*] USB driver for GSM and CDMA modems
Step 4：Configure Kernel to Support PPP
[*] Device Drivers → [*] Network device support → [*] PPP (point-to-point protocol) support
5.编译内核
make
将编译好的内核下载到开发板。
二、模块测试
将重新编译好的内核下载到开发板之后，待系统重新启动，如果是带RNDIS网卡的驱动，在/dev/目录下会出现如下设备节点：
Air726的AT端口是/dev/ttyUSB2，现在你可以使用UART端口工具如“minicom”或“busybox microcom”测试AT功能，结果如下：
三、PPP拨号
通过几个不同的配置文件，在拨号的时候选择相应的配置文件，现将配置文件列举如下：
/etc/ppp/peers/air720-ppp
# /etc/ppp/peers/air720-pppd # Usage:root>pppd call air720-pppd #Modem path, like /dev/ttyUSB3,/dev/ttyACM0, depend on your module, default path is /dev/ttyUSB3 /dev/ttyUSB3 115200 #Insert the username and password for authentication, default user and password are test user "" password "" # The chat script, customize your APN in this file connect 'chat -s -v -f /etc/ppp/peers/air720-chat-connect' # The close script disconnect 'chat -s -v -f /etc/ppp/peers/air720-chat-disconnect' # Hide password in debug messages hide-password # The phone is not required to authenticate noauth # Debug info from pppd debug # If you want to use the HSDPA link as your gateway defaultroute # pppd must not propose any IP address to the peer noipdefault # No ppp compression novj novjccomp noccp ipcp-accept-local ipcp-accept-remote local # For sanity, keep a lock on the serial line lock modem dump nodetach # Hardware flow control nocrtscts remotename 3gppp ipparam 3gppp ipcp-max-failure 10 # Ask the peer for up to 2 DNS server addresses usepeerdns
/etc/ppp/peers/air720-chat-connect
#/etc/ppp/peers/air720-chat-connect ABORT "BUSY" ABORT "NO CARRIER" ABORT "ERROR" #ABORT "NO ANSWER" TIMEOUT 10 "" AT "OK-+++\c-OK" ATH0 OK ATE0 OK ATI;+CESQ;+CPIN?;+COPS?;+CEREG?;+CGREG?;&D2 #china unicom's apn is 3gnet #OK AT+CGDCONT=1,"IP","3gnet",,0,0 #OK ATD*99# #China mobile APN OK AT+CGDCONT=1,"IP","cmnet" #OK ATDT*99***1# OK ATD*99# CONNECT ""
/etc/ppp/peers/air720-chat-disconnect
#/etc/ppp/peers/air720-chat-disconnect TIMEOUT 5 ABORT "ERROR" ABORT "NO DIALTONE" ABORT "NO CARRIER" #SAY "\nSending break to the modem\n" "" "+++\c" OK "ATH0" SAY "\nGoodbay\n"
编辑好这几个文件之后，便可以通过pppd进行拨号：
# pppd call air720-ppp &
如果拨号成功会有以下信息打印出来：
此时通过ifconfig命令查看网卡就有一个ppp0网卡出现，这时可以禁用其他网卡，就可以用Air720模块连接到互联网了。
