Index: uspace/lib/c/generic/ddi.c
===================================================================
--- uspace/lib/c/generic/ddi.c	(revision aac1c41761e0243b82c3356b90847ec9e1d7df84)
+++ uspace/lib/c/generic/ddi.c	(revision 9b11a9713f6f55d4238b0f328de4c3d87f51d55d)
@@ -192,5 +192,5 @@
 }
 
-uint8_t pio_read_8(ioport8_t *reg)
+uint8_t pio_read_8(const ioport8_t *reg)
 {
 	const uint8_t val = arch_pio_read_8(reg);
@@ -199,5 +199,5 @@
 }
 
-uint16_t pio_read_16(ioport16_t *reg)
+uint16_t pio_read_16(const ioport16_t *reg)
 {
 	const uint16_t val = arch_pio_read_16(reg);
@@ -206,5 +206,5 @@
 }
 
-uint32_t pio_read_32(ioport32_t *reg)
+uint32_t pio_read_32(const ioport32_t *reg)
 {
 	const uint32_t val = arch_pio_read_32(reg);
Index: uspace/lib/c/generic/pio_trace.c
===================================================================
--- uspace/lib/c/generic/pio_trace.c	(revision aac1c41761e0243b82c3356b90847ec9e1d7df84)
+++ uspace/lib/c/generic/pio_trace.c	(revision 9b11a9713f6f55d4238b0f328de4c3d87f51d55d)
@@ -91,5 +91,5 @@
 
 
-void pio_trace_log(volatile void *r, uint32_t val, bool write)
+void pio_trace_log(const volatile void *r, uint32_t val, bool write)
 {
 	pio_regions_t *regions = get_regions();