Linux platform device-driven match automatic matching

<span style= "FONT-SIZE:14PX;" >struct Platform_device {   //linux/platform_device.hconst char* name;intid;struct devicedev;u32num_resources; struct resource* resource;struct platform_device_id*id_entry;/* Arch specific additions */struct Pdev_archdataarchdata ;}; </span>

There is also a more important structure resource more critical, usually < Span style= "font-size:14px" > define a platform_device General need to initialize two aspects of the content: device occupied by the resources resource and device private data dev.platform_data. The resources occupied by the device are mainly two aspects: IO memory and IRQ resource.

struct Resource {   //linux/ioportsresource_size_t start;resource_size_t end;const char *name;unsigned long flags; struct resource *parent, *sibling, *child;};

static struct resource myled_resource[] = {        [0] = {                . Start = 0x56000010,                . End   = 0x56000010 + +,                . Flag s = Ioresource_mem        },};

struct Platform_driver {int (*probe) (struct platform_device *); int (*remove) (struct platform_device *); void (*shutdown) (struct platform_device *); int (*suspend) (struct Platform_device *, pm_message_t State); Int (*resume) (struct PLATFORM_ device *); struct device_driver driver;struct platform_device_id *id_table;};

A bus_type instance is defined for the platform bus in the system platform_bus_type,struct bus_type platform_bus_type = {    . Name = "Platform",    . Dev_attrs = Platform_dev_attrs,    . Match = Platform_match,    . uevent = platform_uevent,    . PM = Platform_pm_ops _ptr,}; EXPORT_SYMBOL_GPL (Platform_bus_type); The focus here is on the match () member function, which shows how Platform_device and Platform_driver match. static int Platform_match (struct device *dev, struct device_driver *drv) {    struct platform_device *pdev;    Pdev = container_of (dev, struct platform_device, dev);    Return (STRNCMP (Pdev->name, drv->name, bus_id_size) = = 0);} Matching Platform_device and Platform_driver mainly depends on whether the name field is the same. The definition of Platform_device is usually implemented in the BSP Board file, in the board file, the Platform_device is summed up as an array, which is eventually registered through the Platform_add_devices () function. The Platform_add_devices () function can add a platform device to the system, and the prototype of the function is: int platform_add_devices (struct platform_device **devs, int num); /The first parameter of the function is a pointer to the platform device array, the second parameter is the number of platform devices, which internally calls the Platform_device_register () function to register a single platform device.

Example

MYLED.C Equipment

static struct Platform_device myledplatform_device_led = {        . Name           = "Myled_platform_device_driver",        . Id             =-1,        . Num_resources  = array_size (Myled_resource),        . Resource       = Myled_resource,        . Dev            = {              . Release  = Myled_platform_device_release,        },};

myled_drv.c Device Driver

static struct Platform_driver Myled_platform_driver = {. Probe  = Myled_probe,.remove = __devexit_p (Myled_remove),. Driver = {. Name = "Myled_platform_device_driver",. Owner = This_module,}};

as long as we set the Driver.name in the Platform_device and Platform_driver, the match of the platform bus will match automatically .Platform_device and Platform_driver.

Linux platform device-driven match automatic matching