http://blog.csdn.net/flydream0/article/details/8161418
CAN总线在嵌入式Linux下驱动程序的实现
http://www.21ic.com/app/embed/200911/49216.htm
Socke Can设置波特率
找到其中一个方法使用IP命令，BUSYBOX制作的IP好像不支持对socketcan的设置，必须要自己去下载iproute2的源代码自己编译。得到IP命令，拷贝到自己系统的bin目录下。
ip link set can0 type can bitrate 250000
设置CNA0的波特率为250K，在设置前需要先把CAN0关闭了，ip set can0 down
可以结贴了，！！！！！！！！！！！！
linux can 总线socket接口测试使用，解释了为什么会从字符设备升级到socket设备
http://blog.chinaunix.net/uid-26119896-id-3452315.html
http://www.cnblogs.com/zym0805/p/4345175.html
dmesg | grep can
root@imx_mfgtools_nogpu:~# dmesg | grep can
can-3v3: 3300 mV
flexcan 2090000.can: device registered (reg_base=a0968000, irq=142)
flexcan 2094000.can: device registered (reg_base=a0970000, irq=143)
can: controller area network core (rev 20120528 abi 9)
can: raw protocol (rev 20120528)
can: broadcast manager protocol (rev 20120528 t)
can: netlink gateway (rev 20130117) max_hops=1
can-3v3: disabling
ifconfig -a
can0 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
NOARP MTU:16 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:10
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Interrupt:142
can1 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
NOARP MTU:16 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:10
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Interrupt:143
ip -details link show can0
root@imx_mfgtools_nogpu:~# ip -details link show can0
2: can0: <NOARP,ECHO> mtu 16 qdisc noop state DOWN mode DEFAULT group default qlen 10
link/can promiscuity 0
can state STOPPED (berr-counter tx 0 rx 0) restart-ms 0
bitrate 0 sample-point 0.000
tq 0 prop-seg 0 phase-seg1 0 phase-seg2 0 sjw 0
flexcan: tseg1 4..16 tseg2 2..8 sjw 1..4 brp 1..256 brp-inc 1
clock 30000000