move generic mmio functions to header file

tests/Makefile

@@ -12,7 +12,7 @@ dumps: $(addsuffix .dump,$(PROGRAMS))
 %.o: %.S
 	$(GCC) $(CFLAGS) -D__ASSEMBLY__=1 -c $< -o $@
 
-%.o: %.c
+%.o: %.c mmio.h
 	$(GCC) $(CFLAGS) -c $< -o $@
 
 %.riscv: %.o crt.o syscalls.o

tests/mmio.h

@@ -0,0 +1,16 @@
+#ifndef __MMIO_H__
+#define __MMIO_H__
+
+static inline void write_reg(unsigned long addr, unsigned int data)
+{
+	volatile unsigned int *ptr = (volatile unsigned int *) addr;
+	*ptr = data;
+}
+
+static inline unsigned long read_reg(unsigned long addr)
+{
+	volatile unsigned int *ptr = (volatile unsigned int *) addr;
+	return *ptr;
+}
+
+#endif

tests/pwm.c

@@ -2,17 +2,7 @@
 #define PWM_DUTY 0x2004
 #define PWM_ENABLE 0x2008
 
-static inline void write_reg(unsigned long addr, unsigned int data)
-{
-	volatile unsigned int *ptr = (volatile unsigned int *) addr;
-	*ptr = data;
-}
-
-static inline unsigned long read_reg(unsigned long addr)
-{
-	volatile unsigned int *ptr = (volatile unsigned int *) addr;
-	return *ptr;
-}
+#include "mmio.h"
 
 int main(void)
 {