linux kernel i2c底层代码跟踪

其实跟上次跟的平台总线有关

在arch/arm/mach-mx6/board-mx6q_sabresd.c　文件中

 static void __init mx6_sabresd_board_init(void)
 {
     ．．．
         strcpy(mxc_i2c0_board_info[].type, "wm8962");
         mxc_i2c0_board_info[].platform_data = &wm8962_config_data;             

         imx6q_add_imx_i2c(, &mx6q_sabresd_i2c_data);
         imx6q_add_imx_i2c(, &mx6q_sabresd_i2c_data);
         imx6q_add_imx_i2c(, &mx6q_sabresd_i2c_data);
     ．．．
 ｝

这里对３个i2c总线进行添加

看一下mx6q_sabresd_i2c_data　的原型

 static struct imxi2c_platform_data mx6q_sabresd_i2c_data = {
     //.bitrate = 100000,
     .bitrate = ,
 };                                                                              

设置了i2c　比特率

进里面的代码：

 #define imx6q_add_imx_i2c(id, pdata)    \
     imx_add_imx_i2c(&imx6q_imx_i2c_data[id], pdata)                             

里面是一个宏定义，很显然，这可能是另外一个人写的代码，里面有个结构体

 extern const struct imx_imx_i2c_data imx6q_imx_i2c_data[] __initconst; 

 struct imx_imx_i2c_data {
     int id;
     resource_size_t iobase;
     resource_size_t iosize;
     resource_size_t irq;
 };                                                                              

再进imx_add_imx_i2c() ;

 struct platform_device *__init imx_add_imx_i2c(
         const struct imx_imx_i2c_data *data,
         const struct imxi2c_platform_data *pdata)
 {
     struct resource res[] = {
         {
             .start = data->iobase,
             .end = data->iobase + data->iosize - ,
             .flags = IORESOURCE_MEM,
         }, {
             .start = data->irq,
             .end = data->irq,
             .flags = IORESOURCE_IRQ,
         },
     };                                                                          

     return imx_add_platform_device("imx-i2c", data->id,
             res, ARRAY_SIZE(res),
             pdata, sizeof(*pdata));
 }