Linux設備驅動編程模型之設備篇

一、數據結構

設備表述符

1. struct device {
2. struct device *parent;/*指向父設備的指針*/
3. /*該字段用於管理device和其他device結構，一起device
4. 與其他結構之間的關系*/
5. struct device_private *p;
7. struct kobject kobj;/*內嵌的kobject結構*/
8. const char *init_name; /* initial name of the device */
9. struct device_type *type;
11. struct semaphore sem; /* semaphore to synchronize calls to
12. * its driver.
13. */
15. struct bus_type *bus;/*指向所連接總線的指針*/ /* type of bus device is on */
16. struct device_driver *driver;/*指向控制設備驅動程序的指針*//* which driver has allocated this
17. device */
18. void *platform_data;/*指向遺留設備驅動程序的私有數據的指針*//* Platform specific data, device
19. core doesn't touch it */
20. struct dev_pm_info power;
22. #ifdef CONFIG_NUMA
23. int numa_node; /* NUMA node this device is close to */
24. #endif
25. u64 *dma_mask; /* dma mask (if dma'able device) */
26. u64 coherent_dma_mask;/* Like dma_mask, but for
27. alloc_coherent mappings as
28. not all hardware supports
29. 64 bit addresses for consistent
30. allocations such descriptors. */
32. struct device_dma_parameters *dma_parms;
34. struct list_head dma_pools;/*www.linuxidc.com聚集的DMA緩沖池鏈表的首部*//* dma pools (if dma'ble) */
36. struct dma_coherent_mem *dma_mem;/*指向設備所使用的一致性DMA存儲器描述符的指針*//* internal for coherent mem
37. override */
38. /* arch specific additions */
39. struct dev_archdata archdata;
41. dev_t devt; /* dev_t, creates the sysfs "dev" */
43. spinlock_t devres_lock;
44. struct list_head devres_head;
46. struct klist_node knode_class;
47. struct class *class;
48. const struct attribute_group **groups; /* optional groups */
50. void (*release)(struct device *dev);/*釋放設備描述符的回調函數*/
51. };

Bus描述符

1. struct bus_type {
2. const char *name;/*總線類型名稱*/
3. /*指向對象的指針，該對象包含總線屬性和用於導出此屬性到sysfs文件系統的方法*/
4. struct bus_attribute *bus_attrs;
5. /*指向對象的指針，該對象包含設備屬性和用於導出此屬性sysfs文件系統的方法*/
6. struct device_attribute *dev_attrs;
7. /*指向對象的指針，該對象包含設備驅動程序屬性和用於導出此屬性到sysfs文件
8. 的方法*/
9. struct driver_attribute *drv_attrs;
10. /*檢驗給定的設備驅動程序是否支持特定設備的方法www.linuxidc.com*/
11. int (*match)(struct device *dev, struct device_driver *drv);
12. /**/
13. int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
14. int (*probe)(struct device *dev);
15. int (*remove)(struct device *dev);
16. void (*shutdown)(struct device *dev);
18. int (*suspend)(struct device *dev, pm_message_t state);
19. int (*resume)(struct device *dev);
21. const struct dev_pm_ops *pm;
23. struct bus_type_private *p;
24. };

設備驅動

1. /*設備驅動程序模型中的每個驅動程序*/
2. struct device_driver {
3. const char *name;/*設備驅動程序的名稱*/
4. struct bus_type *bus;/*指向總線描述符的指針，總線連接所支持的設備*/
6. struct module *owner;/*標識實現設備程序的模塊，如果有的話*/
7. const char *mod_name; /* used for built-in modules */
9. bool suppress_bind_attrs; /* disables bind/unbind via sysfs */
11. int (*probe) (struct device *dev);/*探測設備的方法(檢驗設備驅動程序是否可以控制該設備)*/
12. int (*remove) (struct device *dev);/*移走設備時所調用的方法*/
13. void (*shutdown) (struct device *dev);/*設備斷電時所調用的方法*/
14. int (*suspend) (struct device *dev, pm_message_t state);/*設備置於低功率狀態時所調用的方法*/
15. int (*resume) (struct device *dev);/*設備恢復正常狀態時所調用的方法*/
16. const struct attribute_group **groups;
18. const struct dev_pm_ops *pm;
20. struct driver_private *p;
21. };

類描述符

1. /*
2. * device classes
3. */
4. struct class {
5. const char *name;
6. struct module *owner;
8. struct class_attribute *class_attrs;
9. struct device_attribute *dev_attrs;
10. struct kobject *dev_kobj;
12. int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
13. char *(*devnode)(struct device *dev, mode_t *mode);
15. void (*class_release)(struct class *class);
16. void (*dev_release)(struct device *dev);
18. int (*suspend)(struct device *dev, pm_message_t state);
19. int (*resume)(struct device *dev);
21. const struct dev_pm_ops *pm;
23. struct class_private *p;
24. };