xref: /DragonOS/kernel/src/driver/base/device/driver.rs (revision 911132c4b8ea0e9c49a4e84b9fa1db114102acbb)
1 use super::{
2     bus::{bus_manager, Bus},
3     Device, DeviceMatchName, DeviceMatcher, IdTable,
4 };
5 use crate::{
6     driver::base::kobject::KObject,
7     filesystem::sysfs::{sysfs_instance, Attribute, AttributeGroup},
8 };
9 use alloc::{
10     sync::{Arc, Weak},
11     vec::Vec,
12 };
13 use core::fmt::Debug;
14 use system_error::SystemError;
15 
16 /// @brief: Driver error
17 #[allow(dead_code)]
18 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
19 pub enum DriverError {
20     ProbeError,            // 探测设备失败(该驱动不能初始化这个设备)
21     RegisterError,         // 设备注册失败
22     AllocateResourceError, // 获取设备所需资源失败
23     UnsupportedOperation,  // 不支持的操作
24     UnInitialized,         // 未初始化
25 }
26 
27 impl From<DriverError> for SystemError {
28     fn from(value: DriverError) -> Self {
29         match value {
30             DriverError::ProbeError => SystemError::ENODEV,
31             DriverError::RegisterError => SystemError::ENODEV,
32             DriverError::AllocateResourceError => SystemError::EIO,
33             DriverError::UnsupportedOperation => SystemError::EIO,
34             DriverError::UnInitialized => SystemError::ENODEV,
35         }
36     }
37 }
38 
39 #[inline(always)]
40 pub fn driver_manager() -> &'static DriverManager {
41     &DriverManager
42 }
43 
44 /// 驱动程序应当实现的trait
45 ///
46 /// ## 注意
47 ///
48 /// 由于设备驱动模型需要从Arc<dyn KObject>转换为Arc<dyn Driver>,
49 /// 因此,所有的实现了 Driver trait的结构体,都应该在结构体上方标注`#[cast_to([sync] Driver)]`,
50 /// 否则在运行时会报错
51 pub trait Driver: Sync + Send + Debug + KObject {
52     fn coredump(&self, _device: &Arc<dyn Device>) -> Result<(), SystemError> {
53         Err(SystemError::ENOSYS)
54     }
55 
56     /// @brief: 获取驱动标识符
57     /// @parameter: None
58     /// @return: 该驱动驱动唯一标识符
59     fn id_table(&self) -> Option<IdTable>;
60 
61     fn devices(&self) -> Vec<Arc<dyn Device>>;
62 
63     /// 把设备加入当前驱动管理的列表中
64     fn add_device(&self, device: Arc<dyn Device>);
65 
66     /// 从当前驱动管理的列表中删除设备
67     fn delete_device(&self, device: &Arc<dyn Device>);
68 
69     /// 根据设备名称查找绑定到驱动的设备
70     ///
71     /// 该方法是一个快速查找方法,要求驱动开发者自行实现。
72     ///
73     /// 如果开发者没有实现该方法,则应当返回None
74     ///
75     /// ## 注意
76     ///
77     /// 这是一个内部方法,不应当被外部调用,若要查找设备,请使用`find_device_by_name()`
78     fn __find_device_by_name_fast(&self, _name: &str) -> Option<Arc<dyn Device>> {
79         None
80     }
81 
82     /// 是否禁用sysfs的bind/unbind属性
83     ///
84     /// ## 返回
85     ///
86     /// - true: 禁用
87     /// - false: 不禁用(默认)
88     fn suppress_bind_attrs(&self) -> bool {
89         false
90     }
91 
92     fn bus(&self) -> Option<Weak<dyn Bus>> {
93         None
94     }
95 
96     fn set_bus(&self, bus: Option<Weak<dyn Bus>>);
97 
98     fn groups(&self) -> &'static [&'static dyn AttributeGroup] {
99         &[]
100     }
101 
102     fn dev_groups(&self) -> &'static [&'static dyn AttributeGroup] {
103         &[]
104     }
105 
106     /// 使用什么样的策略来探测设备
107     fn probe_type(&self) -> DriverProbeType {
108         DriverProbeType::DefaultStrategy
109     }
110 }
111 
112 impl dyn Driver {
113     pub fn allows_async_probing(&self) -> bool {
114         match self.probe_type() {
115             DriverProbeType::PreferAsync => true,
116             DriverProbeType::ForceSync => false,
117             DriverProbeType::DefaultStrategy => {
118                 // todo: 判断是否请求异步探测,如果是的话,就返回true
119 
120                 // 由于目前还没有支持异步探测,因此这里暂时返回false
121                 false
122             }
123         }
124     }
125 
126     /// 根据条件寻找一个绑定到这个驱动的设备(低效实现)
127     ///
128     /// ## 参数
129     ///
130     /// - `matcher` - 匹配器
131     /// - `data` - 传给匹配器的数据
132     ///
133     /// ## 注意
134     ///
135     /// 这里的默认实现很低效,请为特定的驱动自行实现高效的查询
136     fn find_device_slow<T: Copy>(
137         &self,
138         matcher: &dyn DeviceMatcher<T>,
139         data: T,
140     ) -> Option<Arc<dyn Device>> {
141         self.devices()
142             .into_iter()
143             .find(|dev| matcher.match_device(dev, data))
144     }
145 
146     /// 根据设备名称查找绑定到驱动的设备
147     ///
148     /// ## 注意
149     ///
150     /// 这里的默认实现很低效,请为特定的驱动自行实现高效的查询
151     pub fn find_device_by_name(&self, name: &str) -> Option<Arc<dyn Device>> {
152         if let Some(r) = self.__find_device_by_name_fast(name) {
153             return Some(r);
154         }
155 
156         return self.find_device_slow(&DeviceMatchName, name);
157     }
158 }
159 
160 /// @brief: 驱动管理器
161 #[derive(Debug, Clone)]
162 pub struct DriverManager;
163 
164 impl DriverManager {
165     /// 注册设备驱动。该设备驱动应当已经设置好其bus字段
166     ///
167     /// ## 参数
168     ///
169     /// - driver: 驱动
170     ///
171     /// 参考 https://code.dragonos.org.cn/xref/linux-6.1.9/drivers/base/driver.c#222
172     pub fn register(&self, driver: Arc<dyn Driver>) -> Result<(), SystemError> {
173         let bus = driver.bus().and_then(|bus| bus.upgrade()).ok_or_else(|| {
174             kerror!(
175                 "DriverManager::register() failed: driver.bus() is None. Driver: '{:?}'",
176                 driver.name()
177             );
178             SystemError::EINVAL
179         })?;
180 
181         let drv_name = driver.name();
182         let other = bus.find_driver_by_name(&drv_name);
183         if other.is_some() {
184             kerror!(
185                 "DriverManager::register() failed: driver '{}' already registered",
186                 drv_name
187             );
188             return Err(SystemError::EBUSY);
189         }
190 
191         bus_manager().add_driver(&driver)?;
192 
193         self.add_groups(&driver, driver.groups()).map_err(|e| {
194             bus_manager().remove_driver(&driver);
195             e
196         })?;
197 
198         // todo: 发送uevent
199 
200         return Ok(());
201     }
202 
203     /// 从系统中删除一个驱动程序
204     #[allow(dead_code)]
205     pub fn unregister(&self, driver: &Arc<dyn Driver>) {
206         self.remove_groups(driver, driver.groups());
207         bus_manager().remove_driver(driver);
208     }
209 
210     /// 参考: https://code.dragonos.org.cn/xref/linux-6.1.9/drivers/base/dd.c#434
211     pub fn driver_sysfs_add(&self, _dev: &Arc<dyn Device>) -> Result<(), SystemError> {
212         todo!("DriverManager::driver_sysfs_add()");
213     }
214 
215     pub fn add_groups(
216         &self,
217         driver: &Arc<dyn Driver>,
218         groups: &'static [&dyn AttributeGroup],
219     ) -> Result<(), SystemError> {
220         let kobj = driver.clone() as Arc<dyn KObject>;
221         return sysfs_instance().create_groups(&kobj, groups);
222     }
223 
224     pub fn remove_groups(&self, driver: &Arc<dyn Driver>, groups: &'static [&dyn AttributeGroup]) {
225         let kobj = driver.clone() as Arc<dyn KObject>;
226         sysfs_instance().remove_groups(&kobj, groups);
227     }
228 
229     /// 为指定的驱动创建一个属性文件
230     ///
231     /// ## 参数
232     ///
233     /// - `driver` 要创建属性文件的驱动
234     /// - `attr` 属性
235     pub fn create_attr_file(
236         &self,
237         driver: &Arc<dyn Driver>,
238         attr: &'static dyn Attribute,
239     ) -> Result<(), SystemError> {
240         let kobj = driver.clone() as Arc<dyn KObject>;
241         return sysfs_instance().create_file(&kobj, attr);
242     }
243 
244     /// 为指定的驱动删除一个属性文件
245     ///
246     /// 如果属性不存在,也不会报错
247     ///
248     /// ## 参数
249     ///
250     /// - `driver` 要删除属性文件的驱动
251     /// - `attr` 属性
252     pub fn remove_attr_file(&self, driver: &Arc<dyn Driver>, attr: &'static dyn Attribute) {
253         let kobj = driver.clone() as Arc<dyn KObject>;
254         sysfs_instance().remove_file(&kobj, attr);
255     }
256 }
257 
258 /// 驱动匹配器
259 ///
260 /// 用于匹配驱动是否符合某个条件
261 ///
262 /// ## 参数
263 ///
264 /// - `T` - 匹配器的数据类型
265 /// - `data` - 匹配器的数据
266 pub trait DriverMatcher<T>: Debug {
267     fn match_driver(&self, driver: &Arc<dyn Driver>, data: T) -> bool;
268 }
269 
270 /// 根据名称匹配驱动
271 #[derive(Debug)]
272 pub struct DriverMatchName;
273 
274 impl DriverMatcher<&str> for DriverMatchName {
275     #[inline(always)]
276     fn match_driver(&self, driver: &Arc<dyn Driver>, data: &str) -> bool {
277         driver.name() == data
278     }
279 }
280 
281 /// enum probe_type - device driver probe type to try
282 /// Device drivers may opt in for special handling of their
283 /// respective probe routines. This tells the core what to
284 /// expect and prefer.
285 ///
286 /// Note that the end goal is to switch the kernel to use asynchronous
287 /// probing by default, so annotating drivers with
288 /// %PROBE_PREFER_ASYNCHRONOUS is a temporary measure that allows us
289 /// to speed up boot process while we are validating the rest of the
290 /// drivers.
291 #[allow(dead_code)]
292 #[derive(Debug, Default)]
293 pub enum DriverProbeType {
294     /// Drivers for "slow" devices which
295     /// probing order is not essential for booting the system may
296     /// opt into executing their probes asynchronously.
297     PreferAsync,
298 
299     /// Use this to annotate drivers that need
300     /// their probe routines to run synchronously with driver and
301     /// device registration (with the exception of -EPROBE_DEFER
302     /// handling - re-probing always ends up being done asynchronously).
303     ForceSync,
304 
305     #[default]
306     /// Used by drivers that work equally well
307     /// whether probed synchronously or asynchronously.
308     DefaultStrategy,
309 }
310