最后编辑于: 2016-03-20 19:12 | 分类: linux | 标签: 驱动 | 浏览数: 737 | 评论数: 0
probe函数中定义的局部变量，如果我想在其他地方使用它怎么办呢？这就需要把它保存起来。
内核提供了这个方法，使用函数platform_set_drvdata()可以将ndev保存成平台总线设备的私有数据。以后再要使用它时只需调用platform_get_drvdata()就可以了。
#define platform_set_drvdata(_dev,data) dev_set_drvdata(&(_dev)->dev, (data))
/* /drivers/base/dd.c */
int dev_set_drvdata(struct device *dev, void *data)
{
int error;
if (!dev->p) {
error = device_private_init(dev);
if (error)
return error;
}
dev->p->driver_data = data;
return 0;
}/* /linux/device.h */
struct device {
struct device *parent;
struct device_private *p;
struct kobject kobj;
const char *init_name; /* initial name of the device */
struct device_type *type;
struct semaphore sem; /* semaphore 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 */
struct dev_pm_info power;
#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. */
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 */
/* arch specific additions */
struct dev_archdata archdata;
dev_t devt; /* dev_t, creates the sysfs "dev" */
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);
}; /* /drivers/base/base.h */
struct device_private {
struct klist klist_children;
struct klist_node knode_parent;
struct klist_node knode_driver;
struct klist_node knode_bus;
struct list_head deferred_probe;
void *driver_data;
struct device *device;
};