diff --git a/drivers/usb/host/ehci-dbg.c b/drivers/usb/host/ehci-dbg.c
new file mode 100644
index 0000000..495e2a3
--- /dev/null
+++ b/drivers/usb/host/ehci-dbg.c
@@ -0,0 +1,755 @@
+/*
+ * Copyright (c) 2001-2002 by David Brownell
+ * 
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/* this file is part of ehci-hcd.c */
+
+#define ehci_dbg(ehci, fmt, args...) \
+	dev_dbg (ehci_to_hcd(ehci)->self.controller , fmt , ## args )
+#define ehci_err(ehci, fmt, args...) \
+	dev_err (ehci_to_hcd(ehci)->self.controller , fmt , ## args )
+#define ehci_info(ehci, fmt, args...) \
+	dev_info (ehci_to_hcd(ehci)->self.controller , fmt , ## args )
+#define ehci_warn(ehci, fmt, args...) \
+	dev_warn (ehci_to_hcd(ehci)->self.controller , fmt , ## args )
+
+#ifdef EHCI_VERBOSE_DEBUG
+#	define vdbg dbg
+#	define ehci_vdbg ehci_dbg
+#else
+#	define vdbg(fmt,args...) do { } while (0)
+#	define ehci_vdbg(ehci, fmt, args...) do { } while (0)
+#endif
+
+#ifdef	DEBUG
+
+/* check the values in the HCSPARAMS register
+ * (host controller _Structural_ parameters)
+ * see EHCI spec, Table 2-4 for each value
+ */
+static void dbg_hcs_params (struct ehci_hcd *ehci, char *label)
+{
+	u32	params = readl (&ehci->caps->hcs_params);
+
+	ehci_dbg (ehci,
+		"%s hcs_params 0x%x dbg=%d%s cc=%d pcc=%d%s%s ports=%d\n",
+		label, params,
+		HCS_DEBUG_PORT (params),
+		HCS_INDICATOR (params) ? " ind" : "",
+		HCS_N_CC (params),
+		HCS_N_PCC (params),
+	        HCS_PORTROUTED (params) ? "" : " ordered",
+		HCS_PPC (params) ? "" : " !ppc",
+		HCS_N_PORTS (params)
+		);
+	/* Port routing, per EHCI 0.95 Spec, Section 2.2.5 */
+	if (HCS_PORTROUTED (params)) {
+		int i;
+		char buf [46], tmp [7], byte;
+
+		buf[0] = 0;
+		for (i = 0; i < HCS_N_PORTS (params); i++) {
+			// FIXME MIPS won't readb() ...
+			byte = readb (&ehci->caps->portroute[(i>>1)]);
+			sprintf(tmp, "%d ", 
+				((i & 0x1) ? ((byte)&0xf) : ((byte>>4)&0xf)));
+			strcat(buf, tmp);
+		}
+		ehci_dbg (ehci, "%s portroute %s\n",
+				label, buf);
+	}
+}
+#else
+
+static inline void dbg_hcs_params (struct ehci_hcd *ehci, char *label) {}
+
+#endif
+
+#ifdef	DEBUG
+
+/* check the values in the HCCPARAMS register
+ * (host controller _Capability_ parameters)
+ * see EHCI Spec, Table 2-5 for each value
+ * */
+static void dbg_hcc_params (struct ehci_hcd *ehci, char *label)
+{
+	u32	params = readl (&ehci->caps->hcc_params);
+
+	if (HCC_ISOC_CACHE (params)) {
+		ehci_dbg (ehci,
+		     "%s hcc_params %04x caching frame %s%s%s\n",
+		     label, params,
+		     HCC_PGM_FRAMELISTLEN (params) ? "256/512/1024" : "1024",
+		     HCC_CANPARK (params) ? " park" : "",
+		     HCC_64BIT_ADDR (params) ? " 64 bit addr" : "");
+	} else {
+		ehci_dbg (ehci,
+		     "%s hcc_params %04x thresh %d uframes %s%s%s\n",
+		     label,
+		     params,
+		     HCC_ISOC_THRES (params),
+		     HCC_PGM_FRAMELISTLEN (params) ? "256/512/1024" : "1024",
+		     HCC_CANPARK (params) ? " park" : "",
+		     HCC_64BIT_ADDR (params) ? " 64 bit addr" : "");
+	}
+}
+#else
+
+static inline void dbg_hcc_params (struct ehci_hcd *ehci, char *label) {}
+
+#endif
+
+#ifdef	DEBUG
+
+static void __attribute__((__unused__))
+dbg_qtd (const char *label, struct ehci_hcd *ehci, struct ehci_qtd *qtd)
+{
+	ehci_dbg (ehci, "%s td %p n%08x %08x t%08x p0=%08x\n", label, qtd,
+		le32_to_cpup (&qtd->hw_next),
+		le32_to_cpup (&qtd->hw_alt_next),
+		le32_to_cpup (&qtd->hw_token),
+		le32_to_cpup (&qtd->hw_buf [0]));
+	if (qtd->hw_buf [1])
+		ehci_dbg (ehci, "  p1=%08x p2=%08x p3=%08x p4=%08x\n",
+			le32_to_cpup (&qtd->hw_buf [1]),
+			le32_to_cpup (&qtd->hw_buf [2]),
+			le32_to_cpup (&qtd->hw_buf [3]),
+			le32_to_cpup (&qtd->hw_buf [4]));
+}
+
+static void __attribute__((__unused__))
+dbg_qh (const char *label, struct ehci_hcd *ehci, struct ehci_qh *qh)
+{
+	ehci_dbg (ehci, "%s qh %p n%08x info %x %x qtd %x\n", label,
+		qh, qh->hw_next, qh->hw_info1, qh->hw_info2,
+		qh->hw_current);
+	dbg_qtd ("overlay", ehci, (struct ehci_qtd *) &qh->hw_qtd_next);
+}
+
+static void __attribute__((__unused__))
+dbg_itd (const char *label, struct ehci_hcd *ehci, struct ehci_itd *itd) 
+{
+	ehci_dbg (ehci, "%s [%d] itd %p, next %08x, urb %p\n",
+		label, itd->frame, itd, le32_to_cpu(itd->hw_next), itd->urb);
+	ehci_dbg (ehci,
+		"  trans: %08x %08x %08x %08x %08x %08x %08x %08x\n", 
+		le32_to_cpu(itd->hw_transaction[0]),
+		le32_to_cpu(itd->hw_transaction[1]),
+		le32_to_cpu(itd->hw_transaction[2]),
+		le32_to_cpu(itd->hw_transaction[3]),
+		le32_to_cpu(itd->hw_transaction[4]),
+		le32_to_cpu(itd->hw_transaction[5]),
+		le32_to_cpu(itd->hw_transaction[6]),
+		le32_to_cpu(itd->hw_transaction[7]));
+	ehci_dbg (ehci,
+		"  buf:   %08x %08x %08x %08x %08x %08x %08x\n", 
+		le32_to_cpu(itd->hw_bufp[0]),
+		le32_to_cpu(itd->hw_bufp[1]),
+		le32_to_cpu(itd->hw_bufp[2]),
+		le32_to_cpu(itd->hw_bufp[3]),
+		le32_to_cpu(itd->hw_bufp[4]),
+		le32_to_cpu(itd->hw_bufp[5]),
+		le32_to_cpu(itd->hw_bufp[6]));
+	ehci_dbg (ehci, "  index: %d %d %d %d %d %d %d %d\n",
+		itd->index[0], itd->index[1], itd->index[2],
+		itd->index[3], itd->index[4], itd->index[5],
+		itd->index[6], itd->index[7]);
+}
+
+static void __attribute__((__unused__))
+dbg_sitd (const char *label, struct ehci_hcd *ehci, struct ehci_sitd *sitd) 
+{
+	ehci_dbg (ehci, "%s [%d] sitd %p, next %08x, urb %p\n",
+		label, sitd->frame, sitd, le32_to_cpu(sitd->hw_next), sitd->urb);
+	ehci_dbg (ehci,
+		"  addr %08x sched %04x result %08x buf %08x %08x\n", 
+		le32_to_cpu(sitd->hw_fullspeed_ep),
+		le32_to_cpu(sitd->hw_uframe),
+		le32_to_cpu(sitd->hw_results),
+		le32_to_cpu(sitd->hw_buf [0]),
+		le32_to_cpu(sitd->hw_buf [1]));
+}
+
+static int __attribute__((__unused__))
+dbg_status_buf (char *buf, unsigned len, const char *label, u32 status)
+{
+	return scnprintf (buf, len,
+		"%s%sstatus %04x%s%s%s%s%s%s%s%s%s%s",
+		label, label [0] ? " " : "", status,
+		(status & STS_ASS) ? " Async" : "",
+		(status & STS_PSS) ? " Periodic" : "",
+		(status & STS_RECL) ? " Recl" : "",
+		(status & STS_HALT) ? " Halt" : "",
+		(status & STS_IAA) ? " IAA" : "",
+		(status & STS_FATAL) ? " FATAL" : "",
+		(status & STS_FLR) ? " FLR" : "",
+		(status & STS_PCD) ? " PCD" : "",
+		(status & STS_ERR) ? " ERR" : "",
+		(status & STS_INT) ? " INT" : ""
+		);
+}
+
+static int __attribute__((__unused__))
+dbg_intr_buf (char *buf, unsigned len, const char *label, u32 enable)
+{
+	return scnprintf (buf, len,
+		"%s%sintrenable %02x%s%s%s%s%s%s",
+		label, label [0] ? " " : "", enable,
+		(enable & STS_IAA) ? " IAA" : "",
+		(enable & STS_FATAL) ? " FATAL" : "",
+		(enable & STS_FLR) ? " FLR" : "",
+		(enable & STS_PCD) ? " PCD" : "",
+		(enable & STS_ERR) ? " ERR" : "",
+		(enable & STS_INT) ? " INT" : ""
+		);
+}
+
+static const char *const fls_strings [] =
+    { "1024", "512", "256", "??" };
+
+static int
+dbg_command_buf (char *buf, unsigned len, const char *label, u32 command)
+{
+	return scnprintf (buf, len,
+		"%s%scommand %06x %s=%d ithresh=%d%s%s%s%s period=%s%s %s",
+		label, label [0] ? " " : "", command,
+		(command & CMD_PARK) ? "park" : "(park)",
+		CMD_PARK_CNT (command),
+		(command >> 16) & 0x3f,
+		(command & CMD_LRESET) ? " LReset" : "",
+		(command & CMD_IAAD) ? " IAAD" : "",
+		(command & CMD_ASE) ? " Async" : "",
+		(command & CMD_PSE) ? " Periodic" : "",
+		fls_strings [(command >> 2) & 0x3],
+		(command & CMD_RESET) ? " Reset" : "",
+		(command & CMD_RUN) ? "RUN" : "HALT"
+		);
+}
+
+static int
+dbg_port_buf (char *buf, unsigned len, const char *label, int port, u32 status)
+{
+	char	*sig;
+
+	/* signaling state */
+	switch (status & (3 << 10)) {
+	case 0 << 10: sig = "se0"; break;
+	case 1 << 10: sig = "k"; break;		/* low speed */
+	case 2 << 10: sig = "j"; break;
+	default: sig = "?"; break;
+	}
+
+	return scnprintf (buf, len,
+		"%s%sport %d status %06x%s%s sig=%s %s%s%s%s%s%s%s%s%s",
+		label, label [0] ? " " : "", port, status,
+		(status & PORT_POWER) ? " POWER" : "",
+		(status & PORT_OWNER) ? " OWNER" : "",
+		sig,
+		(status & PORT_RESET) ? " RESET" : "",
+		(status & PORT_SUSPEND) ? " SUSPEND" : "",
+		(status & PORT_RESUME) ? " RESUME" : "",
+		(status & PORT_OCC) ? " OCC" : "",
+		(status & PORT_OC) ? " OC" : "",
+		(status & PORT_PEC) ? " PEC" : "",
+		(status & PORT_PE) ? " PE" : "",
+		(status & PORT_CSC) ? " CSC" : "",
+		(status & PORT_CONNECT) ? " CONNECT" : ""
+	    );
+}
+
+#else
+static inline void __attribute__((__unused__))
+dbg_qh (char *label, struct ehci_hcd *ehci, struct ehci_qh *qh)
+{}
+
+static inline int __attribute__((__unused__))
+dbg_status_buf (char *buf, unsigned len, const char *label, u32 status)
+{ return 0; }
+
+static inline int __attribute__((__unused__))
+dbg_command_buf (char *buf, unsigned len, const char *label, u32 command)
+{ return 0; }
+
+static inline int __attribute__((__unused__))
+dbg_intr_buf (char *buf, unsigned len, const char *label, u32 enable)
+{ return 0; }
+
+static inline int __attribute__((__unused__))
+dbg_port_buf (char *buf, unsigned len, const char *label, int port, u32 status)
+{ return 0; }
+
+#endif	/* DEBUG */
+
+/* functions have the "wrong" filename when they're output... */
+#define dbg_status(ehci, label, status) { \
+	char _buf [80]; \
+	dbg_status_buf (_buf, sizeof _buf, label, status); \
+	ehci_dbg (ehci, "%s\n", _buf); \
+}
+
+#define dbg_cmd(ehci, label, command) { \
+	char _buf [80]; \
+	dbg_command_buf (_buf, sizeof _buf, label, command); \
+	ehci_dbg (ehci, "%s\n", _buf); \
+}
+
+#define dbg_port(ehci, label, port, status) { \
+	char _buf [80]; \
+	dbg_port_buf (_buf, sizeof _buf, label, port, status); \
+	ehci_dbg (ehci, "%s\n", _buf); \
+}
+
+/*-------------------------------------------------------------------------*/
+
+#ifdef STUB_DEBUG_FILES
+
+static inline void create_debug_files (struct ehci_hcd *bus) { }
+static inline void remove_debug_files (struct ehci_hcd *bus) { }
+
+#else
+
+/* troubleshooting help: expose state in driverfs */
+
+#define speed_char(info1) ({ char tmp; \
+		switch (info1 & (3 << 12)) { \
+		case 0 << 12: tmp = 'f'; break; \
+		case 1 << 12: tmp = 'l'; break; \
+		case 2 << 12: tmp = 'h'; break; \
+		default: tmp = '?'; break; \
+		}; tmp; })
+
+static inline char token_mark (__le32 token)
+{
+	__u32 v = le32_to_cpu (token);
+	if (v & QTD_STS_ACTIVE)
+		return '*';
+	if (v & QTD_STS_HALT)
+		return '-';
+	if (!IS_SHORT_READ (v))
+		return ' ';
+	/* tries to advance through hw_alt_next */
+	return '/';
+}
+
+static void qh_lines (
+	struct ehci_hcd *ehci,
+	struct ehci_qh *qh,
+	char **nextp,
+	unsigned *sizep
+)
+{
+	u32			scratch;
+	u32			hw_curr;
+	struct list_head	*entry;
+	struct ehci_qtd		*td;
+	unsigned		temp;
+	unsigned		size = *sizep;
+	char			*next = *nextp;
+	char			mark;
+
+	if (qh->hw_qtd_next == EHCI_LIST_END)	/* NEC does this */
+		mark = '@';
+	else
+		mark = token_mark (qh->hw_token);
+	if (mark == '/') {	/* qh_alt_next controls qh advance? */
+		if ((qh->hw_alt_next & QTD_MASK) == ehci->async->hw_alt_next)
+			mark = '#';	/* blocked */
+		else if (qh->hw_alt_next == EHCI_LIST_END)
+			mark = '.';	/* use hw_qtd_next */
+		/* else alt_next points to some other qtd */
+	}
+	scratch = le32_to_cpup (&qh->hw_info1);
+	hw_curr = (mark == '*') ? le32_to_cpup (&qh->hw_current) : 0;
+	temp = scnprintf (next, size,
+			"qh/%p dev%d %cs ep%d %08x %08x (%08x%c %s nak%d)",
+			qh, scratch & 0x007f,
+			speed_char (scratch),
+			(scratch >> 8) & 0x000f,
+			scratch, le32_to_cpup (&qh->hw_info2),
+			le32_to_cpup (&qh->hw_token), mark,
+			(__constant_cpu_to_le32 (QTD_TOGGLE) & qh->hw_token)
+				? "data1" : "data0",
+			(le32_to_cpup (&qh->hw_alt_next) >> 1) & 0x0f);
+	size -= temp;
+	next += temp;
+
+	/* hc may be modifying the list as we read it ... */
+	list_for_each (entry, &qh->qtd_list) {
+		td = list_entry (entry, struct ehci_qtd, qtd_list);
+		scratch = le32_to_cpup (&td->hw_token);
+		mark = ' ';
+		if (hw_curr == td->qtd_dma)
+			mark = '*';
+		else if (qh->hw_qtd_next == td->qtd_dma)
+			mark = '+';
+		else if (QTD_LENGTH (scratch)) {
+			if (td->hw_alt_next == ehci->async->hw_alt_next)
+				mark = '#';
+			else if (td->hw_alt_next != EHCI_LIST_END)
+				mark = '/';
+		}
+		temp = snprintf (next, size,
+				"\n\t%p%c%s len=%d %08x urb %p",
+				td, mark, ({ char *tmp;
+				 switch ((scratch>>8)&0x03) {
+				 case 0: tmp = "out"; break;
+				 case 1: tmp = "in"; break;
+				 case 2: tmp = "setup"; break;
+				 default: tmp = "?"; break;
+				 } tmp;}),
+				(scratch >> 16) & 0x7fff,
+				scratch,
+				td->urb);
+		if (temp < 0)
+			temp = 0;
+		else if (size < temp)
+			temp = size;
+		size -= temp;
+		next += temp;
+		if (temp == size)
+			goto done;
+	}
+
+	temp = snprintf (next, size, "\n");
+	if (temp < 0)
+		temp = 0;
+	else if (size < temp)
+		temp = size;
+	size -= temp;
+	next += temp;
+
+done:
+	*sizep = size;
+	*nextp = next;
+}
+
+static ssize_t
+show_async (struct class_device *class_dev, char *buf)
+{
+	struct usb_bus		*bus;
+	struct usb_hcd		*hcd;
+	struct ehci_hcd		*ehci;
+	unsigned long		flags;
+	unsigned		temp, size;
+	char			*next;
+	struct ehci_qh		*qh;
+
+	*buf = 0;
+
+	bus = to_usb_bus(class_dev);
+	hcd = bus->hcpriv;
+	ehci = hcd_to_ehci (hcd);
+	next = buf;
+	size = PAGE_SIZE;
+
+	/* dumps a snapshot of the async schedule.
+	 * usually empty except for long-term bulk reads, or head.
+	 * one QH per line, and TDs we know about
+	 */
+	spin_lock_irqsave (&ehci->lock, flags);
+	for (qh = ehci->async->qh_next.qh; size > 0 && qh; qh = qh->qh_next.qh)
+		qh_lines (ehci, qh, &next, &size);
+	if (ehci->reclaim && size > 0) {
+		temp = scnprintf (next, size, "\nreclaim =\n");
+		size -= temp;
+		next += temp;
+
+		for (qh = ehci->reclaim; size > 0 && qh; qh = qh->reclaim)
+			qh_lines (ehci, qh, &next, &size);
+	}
+	spin_unlock_irqrestore (&ehci->lock, flags);
+
+	return strlen (buf);
+}
+static CLASS_DEVICE_ATTR (async, S_IRUGO, show_async, NULL);
+
+#define DBG_SCHED_LIMIT 64
+
+static ssize_t
+show_periodic (struct class_device *class_dev, char *buf)
+{
+	struct usb_bus		*bus;
+	struct usb_hcd		*hcd;
+	struct ehci_hcd		*ehci;
+	unsigned long		flags;
+	union ehci_shadow	p, *seen;
+	unsigned		temp, size, seen_count;
+	char			*next;
+	unsigned		i;
+	__le32			tag;
+
+	if (!(seen = kmalloc (DBG_SCHED_LIMIT * sizeof *seen, SLAB_ATOMIC)))
+		return 0;
+	seen_count = 0;
+
+	bus = to_usb_bus(class_dev);
+	hcd = bus->hcpriv;
+	ehci = hcd_to_ehci (hcd);
+	next = buf;
+	size = PAGE_SIZE;
+
+	temp = scnprintf (next, size, "size = %d\n", ehci->periodic_size);
+	size -= temp;
+	next += temp;
+
+	/* dump a snapshot of the periodic schedule.
+	 * iso changes, interrupt usually doesn't.
+	 */
+	spin_lock_irqsave (&ehci->lock, flags);
+	for (i = 0; i < ehci->periodic_size; i++) {
+		p = ehci->pshadow [i];
+		if (likely (!p.ptr))
+			continue;
+		tag = Q_NEXT_TYPE (ehci->periodic [i]);
+
+		temp = scnprintf (next, size, "%4d: ", i);
+		size -= temp;
+		next += temp;
+
+		do {
+			switch (tag) {
+			case Q_TYPE_QH:
+				temp = scnprintf (next, size, " qh%d-%04x/%p",
+						p.qh->period,
+						le32_to_cpup (&p.qh->hw_info2)
+							/* uframe masks */
+							& 0xffff,
+						p.qh);
+				size -= temp;
+				next += temp;
+				/* don't repeat what follows this qh */
+				for (temp = 0; temp < seen_count; temp++) {
+					if (seen [temp].ptr != p.ptr)
+						continue;
+					if (p.qh->qh_next.ptr)
+						temp = scnprintf (next, size,
+							" ...");
+					p.ptr = NULL;
+					break;
+				}
+				/* show more info the first time around */
+				if (temp == seen_count && p.ptr) {
+					u32	scratch = le32_to_cpup (
+							&p.qh->hw_info1);
+					struct ehci_qtd	*qtd;
+					char		*type = "";
+
+					/* count tds, get ep direction */
+					temp = 0;
+					list_for_each_entry (qtd,
+							&p.qh->qtd_list,
+							qtd_list) {
+						temp++;
+						switch (0x03 & (le32_to_cpu (
+							qtd->hw_token) >> 8)) {
+						case 0: type = "out"; continue;
+						case 1: type = "in"; continue;
+						}
+					}
+
+					temp = scnprintf (next, size,
+						" (%c%d ep%d%s "
+						"[%d/%d] q%d p%d)",
+						speed_char (scratch),
+						scratch & 0x007f,
+						(scratch >> 8) & 0x000f, type,
+						p.qh->usecs, p.qh->c_usecs,
+						temp,
+						0x7ff & (scratch >> 16));
+
+					if (seen_count < DBG_SCHED_LIMIT)
+						seen [seen_count++].qh = p.qh;
+				} else
+					temp = 0;
+				if (p.qh) {
+					tag = Q_NEXT_TYPE (p.qh->hw_next);
+					p = p.qh->qh_next;
+				}
+				break;
+			case Q_TYPE_FSTN:
+				temp = scnprintf (next, size,
+					" fstn-%8x/%p", p.fstn->hw_prev,
+					p.fstn);
+				tag = Q_NEXT_TYPE (p.fstn->hw_next);
+				p = p.fstn->fstn_next;
+				break;
+			case Q_TYPE_ITD:
+				temp = scnprintf (next, size,
+					" itd/%p", p.itd);
+				tag = Q_NEXT_TYPE (p.itd->hw_next);
+				p = p.itd->itd_next;
+				break;
+			case Q_TYPE_SITD:
+				temp = scnprintf (next, size,
+					" sitd%d-%04x/%p",
+					p.sitd->stream->interval,
+					le32_to_cpup (&p.sitd->hw_uframe)
+						& 0x0000ffff,
+					p.sitd);
+				tag = Q_NEXT_TYPE (p.sitd->hw_next);
+				p = p.sitd->sitd_next;
+				break;
+			}
+			size -= temp;
+			next += temp;
+		} while (p.ptr);
+
+		temp = scnprintf (next, size, "\n");
+		size -= temp;
+		next += temp;
+	}
+	spin_unlock_irqrestore (&ehci->lock, flags);
+	kfree (seen);
+
+	return PAGE_SIZE - size;
+}
+static CLASS_DEVICE_ATTR (periodic, S_IRUGO, show_periodic, NULL);
+
+#undef DBG_SCHED_LIMIT
+
+static ssize_t
+show_registers (struct class_device *class_dev, char *buf)
+{
+	struct usb_bus		*bus;
+	struct usb_hcd		*hcd;
+	struct ehci_hcd		*ehci;
+	unsigned long		flags;
+	unsigned		temp, size, i;
+	char			*next, scratch [80];
+	static char		fmt [] = "%*s\n";
+	static char		label [] = "";
+
+	bus = to_usb_bus(class_dev);
+	hcd = bus->hcpriv;
+	ehci = hcd_to_ehci (hcd);
+	next = buf;
+	size = PAGE_SIZE;
+
+	spin_lock_irqsave (&ehci->lock, flags);
+
+	if (bus->controller->power.power_state) {
+		size = scnprintf (next, size,
+			"bus %s, device %s (driver " DRIVER_VERSION ")\n"
+			"SUSPENDED (no register access)\n",
+			hcd->self.controller->bus->name,
+			hcd->self.controller->bus_id);
+		goto done;
+	}
+
+	/* Capability Registers */
+	i = HC_VERSION(readl (&ehci->caps->hc_capbase));
+	temp = scnprintf (next, size,
+		"bus %s, device %s (driver " DRIVER_VERSION ")\n"
+		"EHCI %x.%02x, hcd state %d\n",
+		hcd->self.controller->bus->name,
+		hcd->self.controller->bus_id,
+		i >> 8, i & 0x0ff, hcd->state);
+	size -= temp;
+	next += temp;
+
+	// FIXME interpret both types of params
+	i = readl (&ehci->caps->hcs_params);
+	temp = scnprintf (next, size, "structural params 0x%08x\n", i);
+	size -= temp;
+	next += temp;
+
+	i = readl (&ehci->caps->hcc_params);
+	temp = scnprintf (next, size, "capability params 0x%08x\n", i);
+	size -= temp;
+	next += temp;
+
+	/* Operational Registers */
+	temp = dbg_status_buf (scratch, sizeof scratch, label,
+			readl (&ehci->regs->status));
+	temp = scnprintf (next, size, fmt, temp, scratch);
+	size -= temp;
+	next += temp;
+
+	temp = dbg_command_buf (scratch, sizeof scratch, label,
+			readl (&ehci->regs->command));
+	temp = scnprintf (next, size, fmt, temp, scratch);
+	size -= temp;
+	next += temp;
+
+	temp = dbg_intr_buf (scratch, sizeof scratch, label,
+			readl (&ehci->regs->intr_enable));
+	temp = scnprintf (next, size, fmt, temp, scratch);
+	size -= temp;
+	next += temp;
+
+	temp = scnprintf (next, size, "uframe %04x\n",
+			readl (&ehci->regs->frame_index));
+	size -= temp;
+	next += temp;
+
+	for (i = 0; i < HCS_N_PORTS (ehci->hcs_params); i++) {
+		temp = dbg_port_buf (scratch, sizeof scratch, label, i + 1,
+				readl (&ehci->regs->port_status [i]));
+		temp = scnprintf (next, size, fmt, temp, scratch);
+		size -= temp;
+		next += temp;
+	}
+
+	if (ehci->reclaim) {
+		temp = scnprintf (next, size, "reclaim qh %p%s\n",
+				ehci->reclaim,
+				ehci->reclaim_ready ? " ready" : "");
+		size -= temp;
+		next += temp;
+	}
+
+#ifdef EHCI_STATS
+	temp = scnprintf (next, size,
+		"irq normal %ld err %ld reclaim %ld (lost %ld)\n",
+		ehci->stats.normal, ehci->stats.error, ehci->stats.reclaim,
+		ehci->stats.lost_iaa);
+	size -= temp;
+	next += temp;
+
+	temp = scnprintf (next, size, "complete %ld unlink %ld\n",
+		ehci->stats.complete, ehci->stats.unlink);
+	size -= temp;
+	next += temp;
+#endif
+
+done:
+	spin_unlock_irqrestore (&ehci->lock, flags);
+
+	return PAGE_SIZE - size;
+}
+static CLASS_DEVICE_ATTR (registers, S_IRUGO, show_registers, NULL);
+
+static inline void create_debug_files (struct ehci_hcd *ehci)
+{
+	struct class_device *cldev = &ehci_to_hcd(ehci)->self.class_dev;
+
+	class_device_create_file(cldev, &class_device_attr_async);
+	class_device_create_file(cldev, &class_device_attr_periodic);
+	class_device_create_file(cldev, &class_device_attr_registers);
+}
+
+static inline void remove_debug_files (struct ehci_hcd *ehci)
+{
+	struct class_device *cldev = &ehci_to_hcd(ehci)->self.class_dev;
+
+	class_device_remove_file(cldev, &class_device_attr_async);
+	class_device_remove_file(cldev, &class_device_attr_periodic);
+	class_device_remove_file(cldev, &class_device_attr_registers);
+}
+
+#endif /* STUB_DEBUG_FILES */
+