tree:   https://github.com/frank-w/BPI-R2-4.14 5.8-main
head:   c005c8640ef47f9bc527cd2d669f887ce1018989
commit: f2f6eae7483a73ffcc8fc71c1dce29ea227a4cef [6/62] mt6625l: add changes outside driver dir
config: arm64-randconfig-r035-20200812 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 30c1633386e7cfb01c0a54b31ccf4c3a3873e71b)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        git checkout f2f6eae7483a73ffcc8fc71c1dce29ea227a4cef
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/soc/mediatek/mtk-pmic-wrap.c:2022:16: warning: no previous prototype for function 'pwrap_node_to_regmap' [-Wmissing-prototypes]
   struct regmap *pwrap_node_to_regmap(struct device_node *np)
                  ^
   drivers/soc/mediatek/mtk-pmic-wrap.c:2022:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   struct regmap *pwrap_node_to_regmap(struct device_node *np)
   ^
   static 
   1 warning generated.

vim +/pwrap_node_to_regmap +2022 drivers/soc/mediatek/mtk-pmic-wrap.c

  2021	
> 2022	struct regmap *pwrap_node_to_regmap(struct device_node *np)
  2023	{
  2024		struct platform_device *pdev;
  2025		struct pmic_wrapper *wrp;
  2026		pdev = of_find_device_by_node(np);
  2027		if (!pdev)
  2028			return ERR_PTR(-ENODEV);
  2029		wrp = platform_get_drvdata(pdev);
  2030		return wrp->regmap;
  2031	}
  2032	EXPORT_SYMBOL_GPL(pwrap_node_to_regmap);
  2033	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org