函数static inline void platform_set_drvdata(struct platform_device *pdev, void *data)目的存储用户在probe()中主动申请的内存区域的指针以防止丢失，
static inline void *platform_get_drvdata(const struct platform_device *pdev)则是将其取出。
函数platform_set_drvdata()和platform_get_drvdata(),定义于..includelinuxplatform_device.h:
static inline void platform_set_drvdata(struct platform_device *pdev, void *data)
{
dev_set_drvdata(&pdev->dev, data);
}
static inline void *platform_get_drvdata(const struct platform_device *pdev)
{
return dev_get_drvdata(&pdev->dev);
}
分析发现，函数platform_set_drvdata()调用了函数dev_set_drvdata(),函数dev_set_drvdata()定义于..includelinuxDd.h:
int dev_set_drv_data(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;
}
将data指向的内存地址赋予了dev->p->driver_data，分析platform_device结构体
platform_device 结构体定义于..includelinuxplatform_device.h：
struct platform_device {
const char * name;
int id;
struct device dev;
u32 num_resources;
struct resource * resource;
const struct platform_device_id *id_entry;
/* MFD cell pointer */
struct mfd_cell *mfd_cell;
/* arch specific additions */
struct pdev_archdata archdata;
};
device 结构体定义于..includelinuxDevice.h：
struct device {
struct device *parent;
struct device_private *p;
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 */
struct dev_pm_info power;
struct dev_pm_domain *pm_domain;
#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;
struct device_node *of_node; /* associated device tree 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);
};
device_private结构体定义于..driversaseBase.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;
};
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原文链接：https://blog.csdn.net/skycover/java/article/details/69950727