diff --git a/drivers/usb/usbssp/gadget.h b/drivers/usb/usbssp/gadget.h
index 486e868068b7..6b634dc63d9e 100644
--- a/drivers/usb/usbssp/gadget.h
+++ b/drivers/usb/usbssp/gadget.h
@@ -922,6 +922,73 @@ struct usbssp_transfer_event {
 #define COMP_UNDEFINED_ERROR		33
 #define COMP_INVALID_STREAM_ID_ERROR	34
 
+static inline const char *usbssp_trb_comp_code_string(u8 status)
+{
+	switch (status) {
+	case COMP_INVALID:
+		return "Invalid";
+	case COMP_SUCCESS:
+		return "Success";
+	case COMP_DATA_BUFFER_ERROR:
+		return "Data Buffer Error";
+	case COMP_BABBLE_DETECTED_ERROR:
+		return "Babble Detected";
+	case COMP_USB_TRANSACTION_ERROR:
+		return "USB Transaction Error";
+	case COMP_TRB_ERROR:
+		return "TRB Error";
+	case COMP_RESOURCE_ERROR:
+		return "Resource Error";
+	case COMP_NO_SLOTS_AVAILABLE_ERROR:
+		return "No Slots Available Error";
+	case COMP_INVALID_STREAM_TYPE_ERROR:
+		return "Invalid Stream Type Error";
+	case COMP_SLOT_NOT_ENABLED_ERROR:
+		return "Slot Not Enabled Error";
+	case COMP_ENDPOINT_NOT_ENABLED_ERROR:
+		return "Endpoint Not Enabled Error";
+	case COMP_SHORT_PACKET:
+		return "Short Packet";
+	case COMP_RING_UNDERRUN:
+		return "Ring Underrun";
+	case COMP_RING_OVERRUN:
+		return "Ring Overrun";
+	case COMP_VF_EVENT_RING_FULL_ERROR:
+		return "VF Event Ring Full Error";
+	case COMP_PARAMETER_ERROR:
+		return "Parameter Error";
+	case COMP_CONTEXT_STATE_ERROR:
+		return "Context State Error";
+	case COMP_EVENT_RING_FULL_ERROR:
+		return "Event Ring Full Error";
+	case COMP_INCOMPATIBLE_DEVICE_ERROR:
+		return "Incompatible Device Error";
+	case COMP_MISSED_SERVICE_ERROR:
+		return "Missed Service Error";
+	case COMP_COMMAND_RING_STOPPED:
+		return "Command Ring Stopped";
+	case COMP_COMMAND_ABORTED:
+		return "Command Aborted";
+	case COMP_STOPPED:
+		return "Stopped";
+	case COMP_STOPPED_LENGTH_INVALID:
+		return "Stopped - Length Invalid";
+	case COMP_STOPPED_SHORT_PACKET:
+		return "Stopped - Short Packet";
+	case COMP_MAX_EXIT_LATENCY_TOO_LARGE_ERROR:
+		return "Max Exit Latency Too Large Error";
+	case COMP_ISOCH_BUFFER_OVERRUN:
+		return "Isoch Buffer Overrun";
+	case COMP_EVENT_LOST_ERROR:
+		return "Event Lost Error";
+	case COMP_UNDEFINED_ERROR:
+		return "Undefined Error";
+	case COMP_INVALID_STREAM_ID_ERROR:
+		return "Invalid Stream ID Error";
+	default:
+		return "Unknown!!";
+	}
+}
 struct usbssp_link_trb {
 	/* 64-bit segment pointer*/
 	__le64 segment_ptr;
@@ -1274,6 +1341,27 @@ enum usbssp_ring_type {
 	TYPE_EVENT,
 };
 
+static inline const char *usbssp_ring_type_string(enum usbssp_ring_type type)
+{
+	switch (type) {
+	case TYPE_CTRL:
+		return "CTRL";
+	case TYPE_ISOC:
+		return "ISOC";
+	case TYPE_BULK:
+		return "BULK";
+	case TYPE_INTR:
+		return "INTR";
+	case TYPE_STREAM:
+		return "STREAM";
+	case TYPE_COMMAND:
+		return "CMD";
+	case TYPE_EVENT:
+		return "EVENT";
+	}
+
+	return "UNKNOWN";
+}
 struct usbssp_ring {
 	struct usbssp_segment	*first_seg;
 	struct usbssp_segment	*last_seg;
@@ -1564,4 +1652,488 @@ struct usbssp_udc {
 #define usbssp_info(usbssp_data, fmt, args...) \
 	dev_info(usbssp_data->dev, fmt, ## args)
 
+/*
+ * Registers should always be accessed with double word or quad word accesses.
+ *
+ * Registers with 64-bit address pointers should be written to with
+ * dword accesses by writing the low dword first (ptr[0]), then the high dword
+ * (ptr[1]) second. DC implementations that do not support 64-bit address
+ * pointers will ignore the high dword, and write order is irrelevant.
+ */
+static inline u64 usbssp_read_64(const struct usbssp_udc *usbssp_data,
+		__le64 __iomem *regs)
+{
+	return lo_hi_readq(regs);
+}
+
+static inline void usbssp_write_64(struct usbssp_udc *usbssp_data,
+				 const u64 val, __le64 __iomem *regs)
+{
+	lo_hi_writeq(val, regs);
+}
+static inline char *usbssp_slot_state_string(u32 state)
+{
+	switch (state) {
+	case SLOT_STATE_ENABLED:
+		return "enabled/disabled";
+	case SLOT_STATE_DEFAULT:
+		return "default";
+	case SLOT_STATE_ADDRESSED:
+		return "addressed";
+	case SLOT_STATE_CONFIGURED:
+		return "configured";
+	default:
+		return "reserved";
+	}
+}
+
+static inline const char *usbssp_decode_trb(u32 field0, u32 field1, u32 field2,
+		u32 field3)
+{
+	static char str[256];
+	int type = TRB_FIELD_TO_TYPE(field3);
+
+	switch (type) {
+	case TRB_LINK:
+		sprintf(str,
+			"LINK %08x%08x intr %d type '%s' flags %c:%c:%c:%c",
+			field1, field0, GET_INTR_TARGET(field2),
+			usbssp_trb_type_string(type),
+			field3 & TRB_IOC ? 'I' : 'i',
+			field3 & TRB_CHAIN ? 'C' : 'c',
+			field3 & TRB_TC ? 'T' : 't',
+			field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	case TRB_TRANSFER:
+	case TRB_COMPLETION:
+	case TRB_PORT_STATUS:
+	case TRB_DOORBELL:
+	case TRB_HC_EVENT:
+	case TRB_DEV_NOTE:
+	case TRB_MFINDEX_WRAP:
+		sprintf(str,
+			"TRB %08x%08x status '%s' len %d slot %d ep %d:=:"
+			"type '%s' flags %c:%c",
+			field1, field0,
+			usbssp_trb_comp_code_string(GET_COMP_CODE(field2)),
+			EVENT_TRB_LEN(field2), TRB_TO_SLOT_ID(field3),
+			/* Macro decrements 1, maybe it shouldn't?!? */
+			TRB_TO_EP_INDEX(field3) + 1,
+			usbssp_trb_type_string(type),
+			field3 & EVENT_DATA ? 'E' : 'e',
+			field3 & TRB_CYCLE ? 'C' : 'c');
+
+		break;
+	case TRB_SETUP:
+		sprintf(str, "bRequestType %02x bRequest %02x wValue %02x%02x "
+				"wIndex %02x%02x wLength %d length %d "
+				"TD size %d intr %d type '%s' flags %c:%c:%c",
+				field0 & 0xff,
+				(field0 & 0xff00) >> 8,
+				(field0 & 0xff000000) >> 24,
+				(field0 & 0xff0000) >> 16,
+				(field1 & 0xff00) >> 8,
+				field1 & 0xff,
+				(field1 & 0xff000000) >> 16 |
+				(field1 & 0xff0000) >> 16,
+				TRB_LEN(field2), GET_TD_SIZE(field2),
+				GET_INTR_TARGET(field2),
+				usbssp_trb_type_string(type),
+				field3 & TRB_IDT ? 'I' : 'i',
+				field3 & TRB_IOC ? 'I' : 'i',
+				field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	case TRB_DATA:
+		sprintf(str, "Buffer %08x%08x length %d TD size %d intr %d "
+				"type '%s' flags %c:%c:%c:%c:%c:%c:%c",
+				field1, field0, TRB_LEN(field2),
+				GET_TD_SIZE(field2),
+				GET_INTR_TARGET(field2),
+				usbssp_trb_type_string(type),
+				field3 & TRB_IDT ? 'I' : 'i',
+				field3 & TRB_IOC ? 'I' : 'i',
+				field3 & TRB_CHAIN ? 'C' : 'c',
+				field3 & TRB_NO_SNOOP ? 'S' : 's',
+				field3 & TRB_ISP ? 'I' : 'i',
+				field3 & TRB_ENT ? 'E' : 'e',
+				field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	case TRB_STATUS:
+		sprintf(str, "Buffer %08x%08x length %d TD size %d intr"
+				"%d type '%s' flags %c:%c:%c:%c",
+				field1, field0, TRB_LEN(field2),
+				GET_TD_SIZE(field2),
+				GET_INTR_TARGET(field2),
+				usbssp_trb_type_string(type),
+				field3 & TRB_IOC ? 'I' : 'i',
+				field3 & TRB_CHAIN ? 'C' : 'c',
+				field3 & TRB_ENT ? 'E' : 'e',
+				field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	case TRB_NORMAL:
+	case TRB_ISOC:
+	case TRB_EVENT_DATA:
+	case TRB_TR_NOOP:
+		sprintf(str,
+			"Buffer %08x%08x length %d TD size %d intr %d "
+			"type '%s' flags %c:%c:%c:%c:%c:%c:%c:%c",
+			field1, field0, TRB_LEN(field2), GET_TD_SIZE(field2),
+			GET_INTR_TARGET(field2),
+			usbssp_trb_type_string(type),
+			field3 & TRB_BEI ? 'B' : 'b',
+			field3 & TRB_IDT ? 'I' : 'i',
+			field3 & TRB_IOC ? 'I' : 'i',
+			field3 & TRB_CHAIN ? 'C' : 'c',
+			field3 & TRB_NO_SNOOP ? 'S' : 's',
+			field3 & TRB_ISP ? 'I' : 'i',
+			field3 & TRB_ENT ? 'E' : 'e',
+			field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+
+	case TRB_CMD_NOOP:
+	case TRB_ENABLE_SLOT:
+		sprintf(str,
+			"%s: flags %c",
+			usbssp_trb_type_string(type),
+			field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	case TRB_DISABLE_SLOT:
+		sprintf(str,
+			"%s: slot %d flags %c",
+			usbssp_trb_type_string(type),
+			TRB_TO_SLOT_ID(field3),
+			field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	case TRB_ADDR_DEV:
+		sprintf(str,
+			"%s: ctx %08x%08x slot %d flags %c:%c",
+			usbssp_trb_type_string(type),
+			field1, field0,
+			TRB_TO_SLOT_ID(field3),
+			field3 & TRB_BSR ? 'B' : 'b',
+			field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	case TRB_CONFIG_EP:
+		sprintf(str,
+			"%s: ctx %08x%08x slot %d flags %c:%c",
+			usbssp_trb_type_string(type),
+			field1, field0,
+			TRB_TO_SLOT_ID(field3),
+			field3 & TRB_DC ? 'D' : 'd',
+			field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	case TRB_EVAL_CONTEXT:
+		sprintf(str,
+			"%s: ctx %08x%08x slot %d flags %c",
+			usbssp_trb_type_string(type),
+			field1, field0,
+			TRB_TO_SLOT_ID(field3),
+			field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	case TRB_RESET_EP:
+		sprintf(str,
+			"%s: ctx %08x%08x slot %d ep %d flags %c",
+			usbssp_trb_type_string(type),
+			field1, field0,
+			TRB_TO_SLOT_ID(field3),
+			/* Macro decrements 1, maybe it shouldn't?!? */
+			TRB_TO_EP_INDEX(field3) + 1,
+			field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	case TRB_STOP_RING:
+		sprintf(str,
+			"%s: slot %d sp %d ep %d flags %c",
+			usbssp_trb_type_string(type),
+			TRB_TO_SLOT_ID(field3),
+			TRB_TO_SUSPEND_PORT(field3),
+			/* Macro decrements 1, maybe it shouldn't?!? */
+			TRB_TO_EP_INDEX(field3) + 1,
+			field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	case TRB_SET_DEQ:
+		sprintf(str,
+			"%s: deq %08x%08x stream %d slot %d ep %d flags %c",
+			usbssp_trb_type_string(type),
+			field1, field0,
+			TRB_TO_STREAM_ID(field2),
+			TRB_TO_SLOT_ID(field3),
+			/* Macro decrements 1, maybe it shouldn't?!? */
+			TRB_TO_EP_INDEX(field3) + 1,
+			field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	case TRB_RESET_DEV:
+		sprintf(str,
+			"%s: slot %d flags %c",
+			usbssp_trb_type_string(type),
+			TRB_TO_SLOT_ID(field3),
+			field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	case TRB_FORCE_EVENT:
+		sprintf(str,
+			"%s: event %08x%08x vf intr %d vf id %d flags %c",
+			usbssp_trb_type_string(type),
+			field1, field0,
+			TRB_TO_VF_INTR_TARGET(field2),
+			TRB_TO_VF_ID(field3),
+			field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	case TRB_SET_LT:
+		sprintf(str,
+			"%s: belt %d flags %c",
+			usbssp_trb_type_string(type),
+			TRB_TO_BELT(field3),
+			field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	case TRB_FORCE_HEADER:
+		sprintf(str,
+			"%s: info %08x%08x%08x pkt type %d roothub port %d flags %c",
+			usbssp_trb_type_string(type),
+			field2, field1, field0 & 0xffffffe0,
+			TRB_TO_PACKET_TYPE(field0),
+			TRB_TO_DEV_PORT(field3),
+			field3 & TRB_CYCLE ? 'C' : 'c');
+		break;
+	default:
+		sprintf(str,
+			"type '%s' -> raw %08x %08x %08x %08x",
+			usbssp_trb_type_string(type),
+			field0, field1, field2, field3);
+	}
+
+	return str;
+}
+
+static inline const char *usbssp_decode_slot_context(u32 info, u32 info2,
+		u32 int_target, u32 state)
+{
+	static char str[1024];
+	u32 speed;
+	int ret = 0;
+
+	speed = info & DEV_SPEED;
+
+	ret = sprintf(str, "%s Ctx Entries %d MEL %d us",
+			({ char *s;
+			switch (speed) {
+			case SLOT_SPEED_FS:
+				s = "full-speed";
+				break;
+			case SLOT_SPEED_LS:
+				s = "low-speed";
+				break;
+			case SLOT_SPEED_HS:
+				s = "high-speed";
+				break;
+			case SLOT_SPEED_SS:
+				s = "super-speed";
+				break;
+			case SLOT_SPEED_SSP:
+				s = "super-speed plus";
+				break;
+			default:
+				s = "UNKNOWN speed";
+			} s; }),
+			(info & LAST_CTX_MASK) >> 27,
+			info2 & MAX_EXIT);
+
+	ret += sprintf(str + ret, " [Intr %d] Addr %d State %s",
+			GET_INTR_TARGET(int_target),
+			state & DEV_ADDR_MASK,
+			usbssp_slot_state_string(GET_SLOT_STATE(state)));
+
+	return str;
+}
+
+
+static inline const char *usbssp_portsc_link_state_string(u32 portsc)
+{
+	switch (portsc & PORT_PLS_MASK) {
+	case XDEV_U0:
+		return "U0";
+	case XDEV_U1:
+		return "U1";
+	case XDEV_U2:
+		return "U2";
+	case XDEV_U3:
+		return "U3";
+	case XDEV_DISABLED:
+		return "Disabled";
+	case XDEV_RXDETECT:
+		return "RxDetect";
+	case XDEV_INACTIVE:
+		return "Inactive";
+	case XDEV_POLLING:
+		return "Polling";
+	case XDEV_RECOVERY:
+		return "Recovery";
+	case XDEV_HOT_RESET:
+		return "Hot Reset";
+	case XDEV_COMP_MODE:
+		return "Compliance mode";
+	case XDEV_TEST_MODE:
+		return "Test mode";
+	case XDEV_RESUME:
+		return "Resume";
+	default:
+		break;
+	}
+	return "Unknown";
+}
+
+static inline const char *usbssp_decode_portsc(u32 portsc)
+{
+	static char str[256];
+	int ret;
+
+	ret = sprintf(str, "%s %s %s Link:%s PortSpeed:%d ",
+			portsc & PORT_POWER	? "Powered" : "Powered-off",
+			portsc & PORT_CONNECT	? "Connected" : "Not-connected",
+			portsc & PORT_PE	? "Enabled" : "Disabled",
+			usbssp_portsc_link_state_string(portsc),
+			DEV_PORT_SPEED(portsc));
+
+	if (portsc & PORT_OC)
+		ret += sprintf(str + ret, "OverCurrent ");
+	if (portsc & PORT_RESET)
+		ret += sprintf(str + ret, "In-Reset ");
+
+	ret += sprintf(str + ret, "Change: ");
+	if (portsc & PORT_CSC)
+		ret += sprintf(str + ret, "CSC ");
+	if (portsc & PORT_PEC)
+		ret += sprintf(str + ret, "PEC ");
+	if (portsc & PORT_WRC)
+		ret += sprintf(str + ret, "WRC ");
+	if (portsc & PORT_OCC)
+		ret += sprintf(str + ret, "OCC ");
+	if (portsc & PORT_RC)
+		ret += sprintf(str + ret, "PRC ");
+	if (portsc & PORT_PLC)
+		ret += sprintf(str + ret, "PLC ");
+	if (portsc & PORT_CEC)
+		ret += sprintf(str + ret, "CEC ");
+	ret += sprintf(str + ret, "Wake: ");
+	if (portsc & PORT_WKCONN_E)
+		ret += sprintf(str + ret, "WCE ");
+	if (portsc & PORT_WKDISC_E)
+		ret += sprintf(str + ret, "WDE ");
+	if (portsc & PORT_WKOC_E)
+		ret += sprintf(str + ret, "WOE ");
+
+	return str;
+}
+
+static inline const char *usbssp_ep_state_string(u8 state)
+{
+	switch (state) {
+	case EP_STATE_DISABLED:
+		return "disabled";
+	case EP_STATE_RUNNING:
+		return "running";
+	case EP_STATE_HALTED:
+		return "halted";
+	case EP_STATE_STOPPED:
+		return "stopped";
+	case EP_STATE_ERROR:
+		return "error";
+	default:
+		return "INVALID";
+	}
+}
+
+static inline const char *usbssp_ep_type_string(u8 type)
+{
+	switch (type) {
+	case ISOC_OUT_EP:
+		return "Isoc OUT";
+	case BULK_OUT_EP:
+		return "Bulk OUT";
+	case INT_OUT_EP:
+		return "Int OUT";
+	case CTRL_EP:
+		return "Ctrl";
+	case ISOC_IN_EP:
+		return "Isoc IN";
+	case BULK_IN_EP:
+		return "Bulk IN";
+	case INT_IN_EP:
+		return "Int IN";
+	default:
+		return "INVALID";
+	}
+}
+
+static inline const char *usbssp_decode_ep_context(u32 info, u32 info2, u64 deq,
+		u32 tx_info)
+{
+	static char str[1024];
+	int ret;
+
+	u32 esit;
+	u16 maxp;
+	u16 avg;
+
+	u8 max_pstr;
+	u8 ep_state;
+	u8 interval;
+	u8 ep_type;
+	u8 burst;
+	u8 cerr;
+	u8 mult;
+
+	bool lsa;
+	bool hid;
+
+	esit = CTX_TO_MAX_ESIT_PAYLOAD_HI(info) << 16 |
+		CTX_TO_MAX_ESIT_PAYLOAD(tx_info);
+
+	ep_state = info & EP_STATE_MASK;
+	max_pstr = CTX_TO_EP_MAXPSTREAMS(info);
+	interval = CTX_TO_EP_INTERVAL(info);
+	mult = CTX_TO_EP_MULT(info) + 1;
+	lsa = !!(info & EP_HAS_LSA);
+
+	cerr = (info2 & (3 << 1)) >> 1;
+	ep_type = CTX_TO_EP_TYPE(info2);
+	hid = !!(info2 & (1 << 7));
+	burst = CTX_TO_MAX_BURST(info2);
+	maxp = MAX_PACKET_DECODED(info2);
+
+	avg = EP_AVG_TRB_LENGTH(tx_info);
+
+	ret = sprintf(str, "State %s mult %d max P. Streams %d %s",
+			usbssp_ep_state_string(ep_state), mult,
+			max_pstr, lsa ? "LSA " : "");
+
+	ret += sprintf(str + ret, "interval %d us max ESIT payload %d CErr %d ",
+			(1 << interval) * 125, esit, cerr);
+
+	ret += sprintf(str + ret, "Type %s %sburst %d maxp %d deq %016llx ",
+			usbssp_ep_type_string(ep_type), hid ? "HID" : "",
+			burst, maxp, deq);
+
+	ret += sprintf(str + ret, "avg trb len %d", avg);
+
+	return str;
+}
+
+/**
+ * next_request - gets the next request on the given list
+ * @list: the request list to operate on
+ *
+ * Caller should take care of locking. This function return %NULL or the first
+ * request available on @list.
+ */
+static inline struct usbssp_request *next_request(struct list_head *list)
+{
+	return list_first_entry_or_null(list, struct usbssp_request, list);
+}
+
+struct usbssp_udc;
+#define to_usbssp_ep(ep) (container_of(ep, struct usbssp_ep, endpoint))
+#define gadget_to_usbssp(g) (container_of(g, struct usbssp_udc, gadget))
+#define request_to_usbssp_request(r) (container_of(r, struct usbssp_request, request))
+
+#define to_usbssp_request(r) (container_of(r, struct usbssp_request, request))
+
 #endif /* __LINUX_USBSSP_GADGET_H */
