Index: uspace/drv/bus/usb/xhci/hw_struct/context.h
===================================================================
--- uspace/drv/bus/usb/xhci/hw_struct/context.h	(revision 45e49e65244f085359a080a0a043bc9b3a697503)
+++ uspace/drv/bus/usb/xhci/hw_struct/context.h	(revision 26beeda2d741763808e2a8f21f8484381ecf8ff3)
@@ -179,12 +179,12 @@
 #define XHCI_CTX_SIZE_SMALL 32
 #define XHCI_ONE_CTX_SIZE(hc) (XHCI_CTX_SIZE_SMALL << hc->csz)
+#define XHCI_GET_CTX_FIELD(type, ctx, hc, ci) (xhci_##type##_ctx_to_charptr(ctx) + (ci) * XHCI_ONE_CTX_SIZE(hc))
+
+/**
+ * Device context: section 6.2.1
+ */
 #define XHCI_DEVICE_CTX_SIZE(hc) ((1 + XHCI_EP_COUNT) * XHCI_ONE_CTX_SIZE(hc))
-
-/**
- * Device context: section 6.2.1
- */
-#define XHCI_GET_DC_FIELD(dev_ctx, hc, dci) ((char*)dev_ctx + (dci) * XHCI_ONE_CTX_SIZE(hc))
-#define XHCI_GET_EP_CTX(dev_ctx, hc, dci) ((xhci_ep_ctx_t *)   XHCI_GET_DC_FIELD(dev_ctx, hc, dci))
-#define XHCI_GET_SLOT_CTX(dev_ctx, hc)    ((xhci_slot_ctx_t *) XHCI_GET_DC_FIELD(dev_ctx, hc, 0))
+#define XHCI_GET_EP_CTX(dev_ctx, hc, dci) ((xhci_ep_ctx_t *)   XHCI_GET_CTX_FIELD(device, (dev_ctx), (hc), (dci)))
+#define XHCI_GET_SLOT_CTX(dev_ctx, hc)    ((xhci_slot_ctx_t *) XHCI_GET_CTX_FIELD(device, (dev_ctx), (hc), 0))
 
 /**
@@ -196,4 +196,12 @@
 typedef struct xhci_device_ctx {
 } xhci_device_ctx_t;
+
+/**
+ * Force type checking.
+ */
+static inline char *xhci_device_ctx_to_charptr(const xhci_device_ctx_t *ctx)
+{
+	return (char *) ctx;
+}
 
 /**
@@ -243,13 +251,18 @@
  * Input context: section 6.2.5
  */
-
-#define XHCI_CTRL_CTX_OFFSET 0
-#define XHCI_DEVICE_CTX_OFFSET 1
-#define XHCI_INPUT_CTX_SIZE(hc) (XHCI_DEVICE_CTX_OFFSET * XHCI_ONE_CTX_SIZE(hc) + XHCI_DEVICE_CTX_SIZE(hc))
-#define XHCI_GET_CTRL_CTX(ictx, hc) (xhci_input_ctrl_ctx_t*)((char*)ictx + XHCI_CTRL_CTX_OFFSET * XHCI_ONE_CTX_SIZE(hc))
-#define XHCI_GET_DEVICE_CTX(ictx, hc) (xhci_device_ctx_t *)((char*)ictx + XHCI_DEVICE_CTX_OFFSET * XHCI_ONE_CTX_SIZE(hc))
+#define XHCI_INPUT_CTX_SIZE(hc) (XHCI_ONE_CTX_SIZE(hc) + XHCI_DEVICE_CTX_SIZE(hc))
+#define XHCI_GET_CTRL_CTX(ictx, hc)  ((xhci_input_ctrl_ctx_t *) XHCI_GET_CTX_FIELD(input, (ictx), (hc), 0))
+#define XHCI_GET_DEVICE_CTX(dev_ctx, hc) ((xhci_device_ctx_t *) XHCI_GET_CTX_FIELD(input, (ictx), (hc), 1))
 
 typedef struct xhci_input_ctx {
 } xhci_input_ctx_t;
+
+/**
+ * Force type checking.
+ */
+static inline char *xhci_input_ctx_to_charptr(const xhci_input_ctx_t *ctx)
+{
+	return (char *) ctx;
+}
 
 /**