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 
     
    #endif
    

    12 
    }

    13 
    

    14 
     
    #if
     (defined CONFIG_SPI_IMX || defined CONFIG_SPI_IMX_MODULE )
    

    15 
     
    static
     
    int
     cspi1_ss[] 
    =
     {GPIO_PORTD 
    +
     
    28
    }; 
    //
    CSPI1 ss0=PD28, ss1=PD27
    

    16 
     
    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 name
    

    29 
            .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 experience
    

    32 
            .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_0
    

    35 
        },

    36 
    };

    37 
    #endif
    

    38 
    #endif
    

    39 
    

    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 
    #endif
    

    51 
    #endif
    

    52 
    

    53 
    }
   

复制代码

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 controllers

    13 
    

    14 
     
   

复制代码

 

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。