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\arch\arm\mach-mx6\board-mx6q_sabresd.c
1 static struct i2c_board_info i2c_board_info_rtc[] __initdata = { 2 //isl1208 does not work on the 1st board that‘s sent to Korea, but we should enbaled it later. 3 #if 1 4 { 5 I2C_BOARD_INFO("isl1208", 0x6F), 6 //.irq = gpio_to_irq(CYNO_GPIO_R10), 7 }, 8 #else 9 //pcf8563 is no longer usned. 10 { 11 I2C_BOARD_INFO("pcf8563", 0x51), 12 //.irq = gpio_to_irq(CYNO_GPIO_R10), 13 }, 14 #endif 15 };
这个busnum号决定了adapter->nr之间的关系，如果相等这把这个总线设备和适配器连接起来
i2c_register_board_info(2, i2c_board_info_rtc, ARRAY_SIZE(i2c_board_info_rtc));
下面我们再来分析下i2c_register_board_info这个文件的定义
在drivers/i2c/i2c-boardinfo.c文件中我们找到这个函数的定义：
1 int __init 2 i2c_register_board_info(int busnum, //这个busnum号决定了adapter->nr之间的关系，如果相等这把这个总线设备和适配器连接起来 3 struct i2c_board_info const *info, unsigned len) 4 { 5 int status; 6 7 down_write(&__i2c_board_lock); 8 9 /* dynamic bus numbers will be assigned after the last static one */ 10 if (busnum >= __i2c_first_dynamic_bus_num) 11 __i2c_first_dynamic_bus_num = busnum + 1; 12 13 for (status = 0; len; len--, info++) { 14 struct i2c_devinfo *devinfo; 15 16 devinfo = kzalloc(sizeof(*devinfo), GFP_KERNEL); 17 if (!devinfo) { 18 pr_debug("i2c-core: can‘t register boardinfo!\n"); 19 status = -ENOMEM; 20 break; 21 } 22 23 devinfo->busnum = busnum; 24 devinfo->board_info = *info; 25 list_add_tail(&devinfo->list, &__i2c_board_list); 26 } 27 28 up_write(&__i2c_board_lock); 29 30 return status; 31 }
在这个函数里面定义了bus_num以及RTC相关信息
下面我们针对这个设备具体分析
我们在/drivers/rtc/rtc-isl1208.c这个文件
static const struct i2c_device_id isl1208_id[] = {
{ "isl1208", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, isl1208_id);
static struct i2c_driver isl1208_driver = {
.driver = {
.name = "rtc-isl1208",
},
.probe = isl1208_probe,
.remove = isl1208_remove,
.id_table = isl1208_id,
};
可以看到isl1208_driver真是这个设备所支持的驱动
一旦一个drivers注册了 定会调用其probe函数去查找其相应的adapter,找到adapter后就注册adapter，使得总线和设备驱动通信
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原文地址：http://www.cnblogs.com/haoxing990/p/4718834.html
