diff --git a/include/lib/mmio.h b/include/lib/mmio.h
index 5d33c59..cb37a1c 100644
--- a/include/lib/mmio.h
+++ b/include/lib/mmio.h
@@ -33,13 +33,34 @@
 
 #include <stdint.h>
 
-void mmio_write_8(uintptr_t addr, uint8_t value);
-uint8_t mmio_read_8(uintptr_t addr);
+static inline void mmio_write_8(uintptr_t addr, uint8_t value)
+{
+	*(volatile uint8_t*)addr = value;
+}
 
-void mmio_write_32(uintptr_t addr, uint32_t value);
-uint32_t mmio_read_32(uintptr_t addr);
+static inline uint8_t mmio_read_8(uintptr_t addr)
+{
+	return *(volatile uint8_t*)addr;
+}
 
-void mmio_write_64(uintptr_t addr, uint64_t value);
-uint64_t mmio_read_64(uintptr_t addr);
+static inline void mmio_write_32(uintptr_t addr, uint32_t value)
+{
+	*(volatile uint32_t*)addr = value;
+}
+
+static inline uint32_t mmio_read_32(uintptr_t addr)
+{
+	return *(volatile uint32_t*)addr;
+}
+
+static inline void mmio_write_64(uintptr_t addr, uint64_t value)
+{
+	*(volatile uint64_t*)addr = value;
+}
+
+static inline uint64_t mmio_read_64(uintptr_t addr)
+{
+	return *(volatile uint64_t*)addr;
+}
 
 #endif /* __MMIO_H__ */