sdio_register_driver()会创建设备名吗？

Question

我读了下面这样的代码。设备名称"my_sdio“是在调用sdio_register_driver()之后还是在调用my_sdio_probe()之后在/dev中创建的？如果两者都不是，设备名称是什么时候创建的？

static struct sdio_driver my_sdio_driver = {
   .name    = "my_sdio",
   .id_table = my_sdio_ids,
   .probe   = my_sdio_probe,
   .remove  = my_sdio_remove,
};

sdio_register_driver(&my_sdio_driver);

Answer 1

sdio_register_driver()和my_sdio_probe()都不会创建名为my_sdio的设备。

函数sdio_register_driver会将你的驱动注册到内核。设备将通过将设备注册到内核来创建。通常在使用register_blkdev或register_chrdev的应用程序代码中。在这里，您将为您的设备指定名称my_sdio。

下面结构中的name参数有助于将驱动程序绑定到设备(在应用程序代码中创建)。

static struct sdio_driver my_sdio_driver = {
   .name    = "my_sdio",
   .id_table = my_sdio_ids,
   .probe   = my_sdio_probe,
   .remove  = my_sdio_remove,
};

只有在找到设备和驱动程序之间的匹配项后，才会调用my_sdio_probe()函数。

来自https://www.kernel.org/doc/Documentation/driver-model/platform.txt

驱动程序绑定由驱动程序核心自动执行，在找到设备和驱动程序之间的匹配后调用驱动程序探测()。如果探测()成功，则驱动程序和设备照常绑定。有三种不同的方法可以找到这样的匹配：

- Whenever a device is registered, the drivers for that bus are
  checked for matches.  Platform devices should be registered very
  early during system boot.

- When a driver is registered using platform_driver_register(), all
  unbound devices on that bus are checked for matches.  Drivers
  usually register later during booting, or by module loading.

- Registering a driver using platform_driver_probe() works just like
  using platform_driver_register(), except that the driver won't
  be probed later if another device registers.  (Which is OK, since
  this interface is only for use with non-hotpluggable devices.)