Table of Contents
One Linux environment variable, device driver model 1. The origin of the Linux device driver model
First review the usual process of device driver compilation
【1】Implement the entry function module_init() and module unloading function module_exit();
【2】Apply for device number, register_chrdev();-----> (related to kernel)
【3】Use udev/mdev mechanism to create device file nodes class_create(), device_create();------>(related to the kernel)
【4】Hardware initialization: 1.io resource mapping ioremap(), the kernel provides gpio library function; 2. Register interrupt. ------->(Hardware related)
【5】Construct the file_operation structure--------> (related to the kernel)
[6] Implement methods of operating hardware xxx_open(), xxx_write()...
Inference: Not only the fourth part of the entire process is related to hardware, but the rest are similar operations. In order to compile device drivers conveniently (without reinventing the wheel) and save manpower, the device driver model is proposed to simplify device driver compilation. process.
2. Device driver model framework
You can view the bus object through the sysfs virtual file system (taking USB as an example)
二Linux driver programming, BUS bus model programming
Concept map
1.Bus object
【1】structbus_type: Bus object linux training institution, describes a bus, manages device and driverlinux driver programming, perfectly matched.
<span class="token keyword">struct</span> bus_type <span class="token punctuation">{</span><span class="token comment">//只列举重要成员</span>
<span class="token keyword">const</span> <span class="token keyword">char</span> <span class="token operator">*</span>name<span class="token punctuation">;</span> <span class="token comment">//总线名字</span>
<span class="token keyword">int</span> <span class="token punctuation">(</span><span class="token operator">*</span>match<span class="token punctuation">)</span><span class="token punctuation">(</span><span class="token keyword">struct</span> device <span class="token operator">*</span>dev<span class="token punctuation">,</span> <span class="token keyword">struct</span> device_driver <span class="token operator">*</span>drv<span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token comment">//匹配方法</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
【2】Register and logout bus
<span class="token keyword">int</span> <span class="token function">bus_register</span><span class="token punctuation">(</span><span class="token keyword">struct</span> bus_type <span class="token operator">*</span>bus<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">void</span> <span class="token function">bus_unregister</span><span class="token punctuation">(</span><span class="token keyword">struct</span> bus_type <span class="token operator">*</span>bus<span class="token punctuation">)</span><span class="token punctuation">;</span>
【3】Build a bus
<span class="token macro property">#<span class="token directive keyword">include</span> <span class="token string"></span></span>
<span class="token macro property">#<span class="token directive keyword">include</span> <span class="token string"></span></span>
<span class="token macro property">#<span class="token directive keyword">include</span> <span class="token string"></span></span>
<span class="token comment">//实例化一个bus对象</span>
<span class="token keyword">struct</span> bus_type mybus <span class="token operator">=</span> <span class="token punctuation">{</span>
<span class="token punctuation">.</span>name <span class="token operator">=</span> <span class="token string">"mybus"</span><span class="token punctuation">,</span>
<span class="token punctuation">.</span>match <span class="token operator">=</span> mybus_match<span class="token punctuation">,</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token function">EXPORT_SYMBOL</span><span class="token punctuation">(</span>mybus<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">//导出总线对象，让device对象和driver对象使用</span>
<span class="token keyword">static</span> <span class="token keyword">int</span> __init <span class="token function">mybus_init</span><span class="token punctuation">(</span><span class="token keyword">void</span><span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"------%s---------n"</span><span class="token punctuation">,</span>__FUNCTION__<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">int</span> ret<span class="token punctuation">;</span>
<span class="token comment">//构建一个总线结果:/sys/bus/mybus</span>
ret <span class="token operator">=</span> <span class="token function">bus_register</span><span class="token punctuation">(</span><span class="token operator">&</span>mybus<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">if</span><span class="token punctuation">(</span>ret <span class="token operator">!=</span> <span class="token number">0</span><span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"bus_register errorn"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">return</span> ret<span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">return</span> <span class="token number">0</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">static</span> <span class="token keyword">void</span> __exit <span class="token function">mybus_exit</span><span class="token punctuation">(</span><span class="token keyword">void</span><span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"------%s---------n"</span><span class="token punctuation">,</span>__FUNCTION__<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">bus_unregister</span><span class="token punctuation">(</span><span class="token operator">&</span>mybus<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token function">module_init</span><span class="token punctuation">(</span>mybus_init<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">module_exit</span><span class="token punctuation">(</span>mybus_exit<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">MODULE_LICENSE</span><span class="token punctuation">(</span><span class="token string">"GPL"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
2.device object
【1】device object: device object, describing device information, including address, interrupt and other data
<span class="token keyword">struct</span> device <span class="token punctuation">{</span><span class="token comment">//只列举重要成员</span>
<span class="token keyword">struct</span> kobject kobj<span class="token punctuation">;</span> <span class="token comment">//所有对象的父类</span>
<span class="token keyword">const</span> <span class="token keyword">char</span> <span class="token operator">*</span>init_name<span class="token punctuation">;</span><span class="token comment">//在/sys/bus/mybus/device的名字，用于在总线中匹配</span>
<span class="token keyword">struct</span> bus_type <span class="token operator">*</span>bus<span class="token punctuation">;</span> <span class="token comment">//指向该device对象依附的总线对象</span>
<span class="token keyword">void</span> <span class="token operator">*</span>platform_data<span class="token punctuation">;</span> <span class="token comment">//自定义的数据，指向任何类型的数据</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
【2】Register and logout bus
<span class="token keyword">int</span> <span class="token function">device_register</span><span class="token punctuation">(</span><span class="token keyword">struct</span> device <span class="token operator">*</span>dev<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">void</span> <span class="token function">device_unregister</span><span class="token punctuation">(</span><span class="token keyword">struct</span> device <span class="token operator">*</span>dev<span class="token punctuation">)</span><span class="token punctuation">;</span>
【3】Write device object
定义一个描述设备的信息的结构体，匹配成功以后让driver对象在总线中领到device对象的信息，实现分离。
<span class="token macro property">#<span class="token directive keyword">include</span> <span class="token string"></span></span>
<span class="token macro property">#<span class="token directive keyword">include</span> <span class="token string"></span></span>
<span class="token macro property">#<span class="token directive keyword">include</span> <span class="token string"></span></span>
<span class="token keyword">extern</span> <span class="token keyword">struct</span> bus_type mybus<span class="token punctuation">;</span>
<span class="token keyword">struct</span> mydev_desc<span class="token punctuation">{</span>
<span class="token keyword">char</span><span class="token operator">*</span> name<span class="token punctuation">;</span>
<span class="token keyword">int</span> irqno<span class="token punctuation">;</span>
<span class="token keyword">unsigned</span> <span class="token keyword">long</span> addr<span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token keyword">struct</span> mydev_desc deviofo <span class="token operator">=</span> <span class="token punctuation">{</span>
<span class="token punctuation">.</span>name <span class="token operator">=</span> <span class="token string">"hqs"</span><span class="token punctuation">,</span>
<span class="token punctuation">.</span>irqno <span class="token operator">=</span> <span class="token number">8877</span><span class="token punctuation">,</span>
<span class="token punctuation">.</span>addr <span class="token operator">=</span> <span class="token number">0x12345678</span><span class="token punctuation">,</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token keyword">void</span> <span class="token function">mydev_release</span><span class="token punctuation">(</span><span class="token keyword">struct</span> device<span class="token operator">*</span> dev<span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"------%s---------n"</span><span class="token punctuation">,</span>__FUNCTION__<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token comment">//构建一个device对象</span>
<span class="token keyword">struct</span> device mydev <span class="token operator">=</span> <span class="token punctuation">{</span>
<span class="token punctuation">.</span>init_name <span class="token operator">=</span> <span class="token string">"fsdev_drv"</span><span class="token punctuation">,</span>
<span class="token punctuation">.</span>bus <span class="token operator">=</span> <span class="token operator">&</span>mybus<span class="token punctuation">,</span>
<span class="token punctuation">.</span>release <span class="token operator">=</span> mydev_release<span class="token punctuation">,</span>
<span class="token punctuation">.</span>platform_data <span class="token operator">=</span> <span class="token operator">&</span>deviofo<span class="token punctuation">,</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token keyword">static</span> <span class="token keyword">int</span> __init <span class="token function">mydev_init</span><span class="token punctuation">(</span><span class="token keyword">void</span><span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"------%s---------n"</span><span class="token punctuation">,</span>__FUNCTION__<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">int</span> ret<span class="token punctuation">;</span>
<span class="token comment">//将device注册到总线中</span>
ret <span class="token operator">=</span> <span class="token function">device_register</span><span class="token punctuation">(</span><span class="token operator">&</span>mydev<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">if</span><span class="token punctuation">(</span>ret <span class="token operator"><</span> <span class="token number">0</span><span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"device_register errorn"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">return</span> ret<span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">return</span> <span class="token number">0</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">static</span> <span class="token keyword">void</span> __exit <span class="token function">mydev_exit</span><span class="token punctuation">(</span><span class="token keyword">void</span><span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"------%s---------n"</span><span class="token punctuation">,</span>__FUNCTION__<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">device_unregister</span><span class="token punctuation">(</span><span class="token operator">&</span>mydev<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token function">module_init</span><span class="token punctuation">(</span>mydev_init<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">module_exit</span><span class="token punctuation">(</span>mydev_exit<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">MODULE_LICENSE</span><span class="token punctuation">(</span><span class="token string">"GPL"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
3.driver对象
【1】driver对象：描述设备驱动发的方式
<span class="token keyword">struct</span> device_driver <span class="token punctuation">{</span><span class="token comment">//只列举重要成员</span>
<span class="token keyword">const</span> <span class="token keyword">char</span> <span class="token operator">*</span>name<span class="token punctuation">;</span><span class="token comment">//在/sys/bus/mybus/driver的名字，用于在总线中匹配</span>
<span class="token keyword">struct</span> bus_type <span class="token operator">*</span>bus<span class="token punctuation">;</span><span class="token comment">//指向该device对象依附的总线对象</span>
<span class="token keyword">int</span> <span class="token punctuation">(</span><span class="token operator">*</span>probe<span class="token punctuation">)</span> <span class="token punctuation">(</span><span class="token keyword">struct</span> device <span class="token operator">*</span>dev<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">//device和driver匹配之后要做的事情</span>
<span class="token keyword">int</span> <span class="token punctuation">(</span><span class="token operator">*</span>remove<span class="token punctuation">)</span> <span class="token punctuation">(</span><span class="token keyword">struct</span> device <span class="token operator">*</span>dev<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">//device和driver分离之后要做的事情</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
【2】注册和注销总线
<span class="token keyword">int</span> <span class="token function">driver_register</span><span class="token punctuation">(</span><span class="token keyword">struct</span> device_driver <span class="token operator">*</span>drv<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">void</span> <span class="token function">driver_unregister</span><span class="token punctuation">(</span><span class="token keyword">struct</span> device_driver <span class="token operator">*</span>drv<span class="token punctuation">)</span><span class="token punctuation">;</span>
【3】编写driver对象
匹配成功以后可以在总线中领到device对象的数据，具体实现在probe函数里。
<span class="token macro property">#<span class="token directive keyword">include</span> <span class="token string"></span></span>
<span class="token macro property">#<span class="token directive keyword">include</span> <span class="token string"></span></span>
<span class="token macro property">#<span class="token directive keyword">include</span> <span class="token string"></span></span>
<span class="token macro property">#<span class="token directive keyword">include</span> <span class="token string"></span></span>
<span class="token keyword">extern</span> <span class="token keyword">struct</span> bus_type mybus<span class="token punctuation">;</span>
<span class="token keyword">struct</span> mydev_desc<span class="token punctuation">{</span>
<span class="token keyword">char</span><span class="token operator">*</span> name<span class="token punctuation">;</span>
<span class="token keyword">int</span> irqno<span class="token punctuation">;</span>
<span class="token keyword">unsigned</span> <span class="token keyword">long</span> addr<span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token keyword">struct</span> mydev_desc<span class="token operator">*</span> pdesc<span class="token punctuation">;</span>
<span class="token keyword">int</span> <span class="token function">mydrv_probe</span><span class="token punctuation">(</span><span class="token keyword">struct</span> device <span class="token operator">*</span>dev<span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"------%s---------n"</span><span class="token punctuation">,</span>__FUNCTION__<span class="token punctuation">)</span><span class="token punctuation">;</span>
pdesc <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token keyword">struct</span> mydev_desc<span class="token operator">*</span><span class="token punctuation">)</span>dev<span class="token operator">-></span>platform_data<span class="token punctuation">;</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"name =%sn"</span><span class="token punctuation">,</span>pdesc<span class="token operator">-></span>name<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"irqno = %dn"</span><span class="token punctuation">,</span>pdesc<span class="token operator">-></span>irqno<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">unsigned</span> <span class="token keyword">long</span> <span class="token operator">*</span> paddr <span class="token operator">=</span> <span class="token function">ioremap</span><span class="token punctuation">(</span>pdesc<span class="token operator">-></span>addr<span class="token punctuation">,</span> <span class="token number">8</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">return</span> <span class="token number">0</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">int</span> mydrv_remove <span class="token punctuation">(</span><span class="token keyword">struct</span> device <span class="token operator">*</span>dev<span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"------%s---------n"</span><span class="token punctuation">,</span>__FUNCTION__<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">return</span> <span class="token number">0</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token comment">//构建一个driver对象</span>
<span class="token keyword">struct</span> device_driver mydrv <span class="token operator">=</span> <span class="token punctuation">{</span>
<span class="token punctuation">.</span>name <span class="token operator">=</span> <span class="token string">"fsdev_drv"</span><span class="token punctuation">,</span>
<span class="token punctuation">.</span>bus <span class="token operator">=</span> <span class="token operator">&</span>mybus<span class="token punctuation">,</span>
<span class="token punctuation">.</span>probe <span class="token operator">=</span> mydrv_probe<span class="token punctuation">,</span>
<span class="token punctuation">.</span>remove <span class="token operator">=</span> mydrv_remove<span class="token punctuation">,</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token keyword">static</span> <span class="token keyword">int</span> __init <span class="token function">mydrv_init</span><span class="token punctuation">(</span><span class="token keyword">void</span><span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"------%s---------n"</span><span class="token punctuation">,</span>__FUNCTION__<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">int</span> ret<span class="token punctuation">;</span>
<span class="token comment">//将device注册到总线中</span>
ret <span class="token operator">=</span> <span class="token function">driver_register</span><span class="token punctuation">(</span><span class="token operator">&</span>mydrv<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">if</span><span class="token punctuation">(</span>ret <span class="token operator"><</span> <span class="token number">0</span><span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"driver_register errorn"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">return</span> ret<span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">return</span> <span class="token number">0</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">static</span> <span class="token keyword">void</span> __exit <span class="token function">mydrv_exit</span><span class="token punctuation">(</span><span class="token keyword">void</span><span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"------%s---------n"</span><span class="token punctuation">,</span>__FUNCTION__<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">driver_unregister</span><span class="token punctuation">(</span><span class="token operator">&</span>mydrv<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token function">module_init</span><span class="token punctuation">(</span>mydrv_init<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">module_exit</span><span class="token punctuation">(</span>mydrv_exit<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">MODULE_LICENSE</span><span class="token punctuation">(</span><span class="token string">"GPL"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
4.device对象和driver对象匹配
【1】实现BUS对象中的match方式（按device对象的名子和driver对象中的名子相匹配）
要注意的是不能直接用device对象中的init_name，而要用device对象中继承的structkobjectkobj;上面的成员name不然会报错
<span class="token keyword">int</span> <span class="token function">mybus_match</span><span class="token punctuation">(</span><span class="token keyword">struct</span> device <span class="token operator">*</span>dev<span class="token punctuation">,</span> <span class="token keyword">struct</span> device_driver <span class="token operator">*</span>drv<span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token comment">//如果匹配成功，match方法一定要返回一个1，失败返回0</span>
<span class="token keyword">if</span><span class="token punctuation">(</span><span class="token operator">!</span> <span class="token function">strncmp</span><span class="token punctuation">(</span>drv<span class="token operator">-></span>name<span class="token punctuation">,</span>dev<span class="token operator">-></span>kobj<span class="token punctuation">.</span>name<span class="token punctuation">,</span><span class="token function">strlen</span><span class="token punctuation">(</span>drv<span class="token operator">-></span>name<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span>
<span class="token punctuation">{</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"match okn"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">return</span> <span class="token number">1</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">else</span>
<span class="token punctuation">{</span>
<span class="token function">printk</span><span class="token punctuation">(</span><span class="token string">"match failedn"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">return</span> <span class="token number">0</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">return</span> <span class="token number">0</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token comment">//实例化一个bus对象</span>
<span class="token keyword">struct</span> bus_type mybus <span class="token operator">=</span> <span class="token punctuation">{</span>
<span class="token punctuation">.</span>name <span class="token operator">=</span> <span class="token string">"mybus"</span><span class="token punctuation">,</span>
<span class="token punctuation">.</span>match <span class="token operator">=</span> mybus_match<span class="token punctuation">,</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
【2】保证device对象和driver对象的名子一样：例如这儿都使用"fsdev_drv"才能保证能匹配成功
<span class="token comment">//构建一个device对象</span>
<span class="token keyword">struct</span> device mydev <span class="token operator">=</span> <span class="token punctuation">{</span>
<span class="token punctuation">.</span>init_name <span class="token operator">=</span> <span class="token string">"fsdev_drv"</span><span class="token punctuation">,</span>
<span class="token punctuation">.</span>bus <span class="token operator">=</span> <span class="token operator">&</span>mybus<span class="token punctuation">,</span>
<span class="token punctuation">.</span>release <span class="token operator">=</span> mydev_release<span class="token punctuation">,</span>
<span class="token punctuation">.</span>platform_data <span class="token operator">=</span> <span class="token operator">&</span>deviofo<span class="token punctuation">,</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token comment">//构建一个driver对象</span>
<span class="token keyword">struct</span> device_driver mydrv <span class="token operator">=</span> <span class="token punctuation">{</span>
<span class="token punctuation">.</span>name <span class="token operator">=</span> <span class="token string">"fsdev_drv"</span><span class="token punctuation">,</span>
<span class="token punctuation">.</span>bus <span class="token operator">=</span> <span class="token operator">&</span>mybus<span class="token punctuation">,</span>
<span class="token punctuation">.</span>probe <span class="token operator">=</span> mydrv_probe<span class="token punctuation">,</span>
<span class="token punctuation">.</span>remove <span class="token operator">=</span> mydrv_remove<span class="token punctuation">,</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
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