驱动笔记

struct bus_type {
	const char		*name;
	const char		*dev_name;
	struct device		*dev_root;
	struct device_attribute	*dev_attrs;	/* use dev_groups instead */
	const struct attribute_group **bus_groups;
	const struct attribute_group **dev_groups;
	const struct attribute_group **drv_groups;

	int (*match)(struct device *dev, struct device_driver *drv);
	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
	int (*probe)(struct device *dev);
	int (*remove)(struct device *dev);
	void (*shutdown)(struct device *dev);

	int (*online)(struct device *dev);
	int (*offline)(struct device *dev);

	int (*suspend)(struct device *dev, pm_message_t state);
	int (*resume)(struct device *dev);

	const struct dev_pm_ops *pm;

	const struct iommu_ops *iommu_ops;

	struct subsys_private *p;
	struct lock_class_key lock_key;
};

struct subsys_private {
	struct kset subsys;
	struct kset *devices_kset;
	struct list_head interfaces;
	struct mutex mutex;

	struct kset *drivers_kset;
	struct klist klist_devices;	// 挂载总线上所有设备的链表
	struct klist klist_drivers;	// 挂载总线上所有驱动的链表
	struct blocking_notifier_head bus_notifier;
	unsigned int drivers_autoprobe:1;
	struct bus_type *bus;

	struct kset glue_dirs;
	struct class *class;
};

struct device {
	struct device		*parent;

	struct device_private	*p;	// 重要

	struct kobject kobj;
	const char		*init_name; /* initial name of the device */
	const struct device_type *type;

	struct mutex		mutex;	/* mutex to synchronize calls to its driver. */

	struct bus_type	*bus;		/* type of bus device is on */
	struct device_driver *driver;	/* which driver has allocated this device */
	void		*platform_data;	/* Platform specific data, device core doesn't touch it */
	void		*driver_data;	/* Driver data, set and get with ev_set/get_drvdata */
	struct dev_pm_info	power;
	struct dev_pm_domain	*pm_domain;

#ifdef CONFIG_PINCTRL
	struct dev_pin_info	*pins;
#endif

#ifdef CONFIG_NUMA
	int		numa_node;	/* NUMA node this device is close to */
#endif
	u64		*dma_mask;	/* dma mask (if dma'able device) */
	u64		coherent_dma_mask;/* Like dma_mask, but for
					     alloc_coherent mappings as
					     not all hardware supports
					     64 bit addresses for consistent
					     allocations such descriptors. */
	unsigned long	dma_pfn_offset;

	struct device_dma_parameters *dma_parms;

	struct list_head	dma_pools;	/* dma pools (if dma'ble) */

	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem override */
#ifdef CONFIG_DMA_CMA
	struct cma *cma_area;		/* contiguous memory area for dma allocations */
#endif
	/* arch specific additions */
	struct dev_archdata	archdata;

	struct device_node	*of_node; /* associated device tree node */
	struct fwnode_handle	*fwnode; /* firmware device node */

	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
	u32			id;	/* device instance */

	spinlock_t		devres_lock;
	struct list_head	devres_head;

	struct klist_node	knode_class;
	struct class		*class;
	const struct attribute_group **groups;	/* optional groups */

	void	(*release)(struct device *dev);
	struct iommu_group	*iommu_group;

	bool			offline_disabled:1;
	bool			offline:1;
};

struct device_driver {
	const char		*name;
	struct bus_type		*bus;

	struct module		*owner;
	const char		*mod_name;	/* used for built-in modules */

	bool suppress_bind_attrs;	/* disables bind/unbind via sysfs */

	const struct of_device_id	*of_match_table;
	const struct acpi_device_id	*acpi_match_table;

	int (*probe) (struct device *dev);
	int (*remove) (struct device *dev);
	void (*shutdown) (struct device *dev);
	int (*suspend) (struct device *dev, pm_message_t state);
	int (*resume) (struct device *dev);
	const struct attribute_group **groups;

	const struct dev_pm_ops *pm;

	struct driver_private *p;	// 重要
};