117 lines
		
	
	
	
		
			2.2 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			117 lines
		
	
	
	
		
			2.2 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
|   | #include <linux/kernel.h>
 | ||
|  | #include <linux/slab.h>
 | ||
|  | #include <linux/module.h>
 | ||
|  | #include <linux/err.h>
 | ||
|  | 
 | ||
|  | #include <linux/usb/composite.h>
 | ||
|  | 
 | ||
|  | static LIST_HEAD(func_list); | ||
|  | static DEFINE_MUTEX(func_lock); | ||
|  | 
 | ||
|  | static struct usb_function_instance *try_get_usb_function_instance(const char *name) | ||
|  | { | ||
|  | 	struct usb_function_driver *fd; | ||
|  | 	struct usb_function_instance *fi; | ||
|  | 
 | ||
|  | 	fi = ERR_PTR(-ENOENT); | ||
|  | 	mutex_lock(&func_lock); | ||
|  | 	list_for_each_entry(fd, &func_list, list) { | ||
|  | 
 | ||
|  | 		if (strcmp(name, fd->name)) | ||
|  | 			continue; | ||
|  | 
 | ||
|  | 		if (!try_module_get(fd->mod)) { | ||
|  | 			fi = ERR_PTR(-EBUSY); | ||
|  | 			break; | ||
|  | 		} | ||
|  | 		fi = fd->alloc_inst(); | ||
|  | 		if (IS_ERR(fi)) | ||
|  | 			module_put(fd->mod); | ||
|  | 		else | ||
|  | 			fi->fd = fd; | ||
|  | 		break; | ||
|  | 	} | ||
|  | 	mutex_unlock(&func_lock); | ||
|  | 	return fi; | ||
|  | } | ||
|  | 
 | ||
|  | struct usb_function_instance *usb_get_function_instance(const char *name) | ||
|  | { | ||
|  | 	struct usb_function_instance *fi; | ||
|  | 	int ret; | ||
|  | 
 | ||
|  | 	fi = try_get_usb_function_instance(name); | ||
|  | 	if (!IS_ERR(fi)) | ||
|  | 		return fi; | ||
|  | 	ret = PTR_ERR(fi); | ||
|  | 	if (ret != -ENOENT) | ||
|  | 		return fi; | ||
|  | 	ret = request_module("usbfunc:%s", name); | ||
|  | 	if (ret < 0) | ||
|  | 		return ERR_PTR(ret); | ||
|  | 	return try_get_usb_function_instance(name); | ||
|  | } | ||
|  | EXPORT_SYMBOL_GPL(usb_get_function_instance); | ||
|  | 
 | ||
|  | struct usb_function *usb_get_function(struct usb_function_instance *fi) | ||
|  | { | ||
|  | 	struct usb_function *f; | ||
|  | 
 | ||
|  | 	f = fi->fd->alloc_func(fi); | ||
|  | 	if (IS_ERR(f)) | ||
|  | 		return f; | ||
|  | 	f->fi = fi; | ||
|  | 	return f; | ||
|  | } | ||
|  | EXPORT_SYMBOL_GPL(usb_get_function); | ||
|  | 
 | ||
|  | void usb_put_function_instance(struct usb_function_instance *fi) | ||
|  | { | ||
|  | 	struct module *mod; | ||
|  | 
 | ||
|  | 	if (!fi) | ||
|  | 		return; | ||
|  | 
 | ||
|  | 	mod = fi->fd->mod; | ||
|  | 	fi->free_func_inst(fi); | ||
|  | 	module_put(mod); | ||
|  | } | ||
|  | EXPORT_SYMBOL_GPL(usb_put_function_instance); | ||
|  | 
 | ||
|  | void usb_put_function(struct usb_function *f) | ||
|  | { | ||
|  | 	if (!f) | ||
|  | 		return; | ||
|  | 
 | ||
|  | 	f->free_func(f); | ||
|  | } | ||
|  | EXPORT_SYMBOL_GPL(usb_put_function); | ||
|  | 
 | ||
|  | int usb_function_register(struct usb_function_driver *newf) | ||
|  | { | ||
|  | 	struct usb_function_driver *fd; | ||
|  | 	int ret; | ||
|  | 
 | ||
|  | 	ret = -EEXIST; | ||
|  | 
 | ||
|  | 	mutex_lock(&func_lock); | ||
|  | 	list_for_each_entry(fd, &func_list, list) { | ||
|  | 		if (!strcmp(fd->name, newf->name)) | ||
|  | 			goto out; | ||
|  | 	} | ||
|  | 	ret = 0; | ||
|  | 	list_add_tail(&newf->list, &func_list); | ||
|  | out: | ||
|  | 	mutex_unlock(&func_lock); | ||
|  | 	return ret; | ||
|  | } | ||
|  | EXPORT_SYMBOL_GPL(usb_function_register); | ||
|  | 
 | ||
|  | void usb_function_unregister(struct usb_function_driver *fd) | ||
|  | { | ||
|  | 	mutex_lock(&func_lock); | ||
|  | 	list_del(&fd->list); | ||
|  | 	mutex_unlock(&func_lock); | ||
|  | } | ||
|  | EXPORT_SYMBOL_GPL(usb_function_unregister); |