在linux2.6.37上添加MCP251x驱动

Socket CAN 对CAN protocol做了封装，对CAN设备的读写变成了类似tcp/ip的读写网络（socket操作）。

目标环境：linux2.6.37， i.mx27开发板带mcp2515

首先注册spi device和mcp2515 device：

 

代码

<!--Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/--> 1 static const int plat27_pins[] __initconst= { 2     ... 3  4  #if (defined CONFIG_SPI_IMX || defined CONFIG_SPI_IMX_MODULE ) 5     //PD27_PF_CSPI1_SS1, //use mxc_gpio_mode instead mxc_gpio_setup_multiple_pins otherwise spi-imx.c can't request it 6     //PD28_PF_CSPI1_SS0, 7      PD25_PF_CSPI1_RDY, 8     PD29_PF_CSPI1_SCLK, 9     PD30_PF_CSPI1_MISO,10     PD31_PF_CSPI1_MOSI,11  #endif12 }13 14  #if (defined CONFIG_SPI_IMX || defined CONFIG_SPI_IMX_MODULE )15  static int cspi1_ss[] = {GPIO_PORTD + 28}; //CSPI1 ss0=PD28, ss1=PD2716  static const struct spi_imx_master cspi_pdata __initconst = {    17     .chipselect = cspi1_ss,    18     .num_chipselect = ARRAY_SIZE(cspi1_ss),19 };20 21 #if (defined CONFIG_CAN_MCP251X || defined CONFIG_CAN_MCP251X_MODULE )22 static struct mcp251x_platform_data mcp251x_info = {23     .oscillator_frequency = 16*1000*1000,24 };25 26 static struct spi_board_info plat27_spi_board_info[] __initdata = {27     {28         .modalias        = "mcp2515",   //must match with device driver id_table name29         .bus_num        = 0,           //0 for CSPI1, 1 for CSPI2, ...30         .chip_select    = 0,           //0 for SS0 ,1 for SS1, ....31         .max_speed_hz    = 2*1000*1000, //maxium is 10MHz, but will lost data in my experience32         .irq            = IRQ_GPIOC(15),33         .platform_data    = &mcp251x_info,34         .mode           = SPI_MODE_0,  //not required exactly since mcp251x driver will set it to SPI_MODE_035     },36 };37 #endif38 #endif39 40 static void __init XXX_init(void)41 {42     ...43     44 #if (defined CONFIG_SPI_IMX || defined CONFIG_SPI_IMX_MODULE )45     mxc_gpio_mode(GPIO_PORTD | 28 | GPIO_GPIO | GPIO_OUT); 46     imx27_add_spi_imx0(&cspi_pdata);47     48 #if (defined CONFIG_CAN_MCP251X || defined CONFIG_CAN_MCP251X_MODULE )49     spi_register_board_info(plat27_spi_board_info, ARRAY_SIZE(plat27_spi_board_info));50 #endif51 #endif52 53 }

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make menuconfig中加入:

 

代码

<!--Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/--> 1 [*]Networking support-> 2     <M>CAN bus subsystem support-> 3         <M>Raw CAN Protocal 4         <M>Broadcast Manage CAN Protocal 5         CAN Device Drivers-> 6             <M>Platform CAN driver with Netlink support 7              [*]CAN bit-timing calculation 8             <M>Microchip MCP251x SPI CAN controllers 9 10 Device drivers->11     [*]SPI support -> 12         <*>Freescale i.MX spi controllers13 14  

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编译安装mod：

insmod can.ko

insmod can-raw.ko

insmod can-bcm.ko

insmod can-dev.ko

insmod mcp251x.ko

 

最新版busybox的ip还是不支持socketcan，所以要自己编译一个。

上http://corp-dev.linuxfoundation.org/collaborate/workgroups/networking/iproute2下载iproute2，目前版本是2.6.35。

编译iproute2的时候有很多问题，安装了bison，flex，libdb4.7-dev还是死在tc目录，后来想想只要用它的ip，于是最终修改Makefile如下：

CC = /opt/arm-2010q1/bin/arm-none-linux-gnueabi-gcc
SUBDIRS=lib ip

make通过，把ip目录中的ip（elf文件）拷到目标板中运行：

chmod 777 ip

./ip link set can0 up type can bitrate 250000
./ip -details link show can0

can0设置好后可以用以下命令修改bitrate

ifconfig can0 down 
echo 125000 > /sys/class/net/can0/can_bitrate 
ifconfig can0 up 
 

到这一步socketcan就算配置完成了，不过还是可以给它添加一些工具。

1.用socketcan里的can-utils：

sudo apt-get install subversion
svn checkout svn://svn.berlios.de/socketcan/trunk socketcan
cp -r socketcan ../Workspaces
修改socketcan/can-utils/Makefile
PREFIX=./bin
KERNELDIR = http://www.cnblogs.com/linux-2.6.37
CC=/opt/arm-2010q1/bin/arm-none-linux-gnueabi-gcc  （新增）
socketcan和linux2.6.37带的socketcan版本不同，导致有些不能编译成功，不过大部分工具都有了，剩下的如果要的话可以考虑merge linux内核----还不如自己写工具呢

2.在http://www.pengutronix.de/software/socket-can下载can-utils 4.0.6，里面有5个工具，不过搞不定它的configure，手工编译之吧：

先在include下建一个can_config.h，里面就一句话#define VERSION 20090105  （随便怎么写吧，我是看到can.ko的版本是20090105） 

然后进到src目录

/opt/arm-2010q1/bin/arm-none-linux-gnueabi-gcc  -o xxx  xxx.c -I$PWD/../include -I$PWD/***/linux-2.6.37/include  （faint，http://www.cnblogs.com/被转成www.cnblogs.com）

除了canconfig.c通不过（需要libsocketcan.h，好在已经有iproute2了）其他的都成功。 感觉这个cansend比socketcan里的cansend好用。