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kernel/linux-imx6_3.14.28/drivers/usb/gadget/functions.c 2.22 KB
6b13f685e   김민수   BSP 최초 추가
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  #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);