driver model: implement platform_match()

- For matching registered platform devices with platform drivers.

- Also, make sure platform_bus is initialized early, with the rest of the 
  core stuff.

drivers/base/init.c

@@ -6,6 +6,7 @@ extern int devices_init(void);
 extern int buses_init(void);
 extern int classes_init(void);
 extern int firmware_init(void);
+extern int platform_bus_init(void);
 extern int sys_bus_init(void);
 extern int cpu_dev_init(void);
 
@@ -27,6 +28,7 @@ void __init driver_init(void)
 	/* These are also core pieces, but must come after the 
 	 * core core pieces.
 	 */
+	platform_bus_init();
 	sys_bus_init();
 	cpu_dev_init();
 }

drivers/base/platform.c

@@ -42,8 +42,28 @@ void platform_device_unregister(struct platform_device * pdev)
 		device_unregister(&pdev->dev);
 }
 
+
+/**
+ *	platform_match - bind platform device to platform driver.
+ *	@dev:	device.
+ *	@drv:	driver.
+ *
+ *	Platform device IDs are assumed to be encoded like this: 
+ *	"<name><instance>", where <name> is a short description of the 
+ *	type of device, like "pci" or "floppy", and <instance> is the 
+ *	enumerated instance of the device, like '0' or '42'.
+ *	Driver IDs are simply "<name>". 
+ *	So, extract the <name> from the device, and compare it against 
+ *	the name of the driver. Return whether they match or not.
+ */
+
 static int platform_match(struct device * dev, struct device_driver * drv)
 {
+	char name[BUS_ID_SIZE];
+
+	if (sscanf(dev->bus_id,"%s",name))
+		return (strcmp(name,drv->name) == 0);
+
 	return 0;
 }
 
@@ -52,13 +72,11 @@ struct bus_type platform_bus_type = {
 	.match		= platform_match,
 };
 
-static int __init platform_bus_init(void)
+int __init platform_bus_init(void)
 {
 	device_register(&legacy_bus);
 	return bus_register(&platform_bus_type);
 }
 
-postcore_initcall(platform_bus_init);
-
 EXPORT_SYMBOL(platform_device_register);
 EXPORT_SYMBOL(platform_device_unregister);