… > +++ b/include/linux/mfd/photonicat-pmu.h > @@ -0,0 +1,86 @@ … > +#ifndef _PHOTONICAT_PMU_H > +#define _PHOTONICAT_PMU_H … I suggest to omit leading underscores from such identifiers. https://wiki.sei.cmu.edu/confluence/display/c/DCL37-C.+Do+not+declare+or+define+a+reserved+identifier Regards, Markus