drivers/usb/host/ohci-dbg.c - kernel/msm-4.9 - Gitiles

 /*
  * OHCI HCD (Host Controller Driver) for USB.
  *
  * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
  * (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
  *
  * This file is licenced under the GPL.
  */

 /*-------------------------------------------------------------------------*/

 #define edstring(ed_type) ({ char *temp; \
 	switch (ed_type) { \
 	case PIPE_CONTROL:	temp = "ctrl"; break; \
 	case PIPE_BULK:		temp = "bulk"; break; \
 	case PIPE_INTERRUPT:	temp = "intr"; break; \
 	default:		temp = "isoc"; break; \
 	} temp;})
 #define pipestring(pipe) edstring(usb_pipetype(pipe))


 #define ohci_dbg_sw(ohci, next, size, format, arg...) \
 	do { \
 	if (next != NULL) { \
 		unsigned s_len; \
 		s_len = scnprintf (*next, *size, format, ## arg ); \
 		*size -= s_len; *next += s_len; \
 	} else \
 		ohci_dbg(ohci,format, ## arg ); \
 	} while (0);

 /* Version for use where "next" is the address of a local variable */
 #define ohci_dbg_nosw(ohci, next, size, format, arg...) \
 	do { \
 		unsigned s_len; \
 		s_len = scnprintf(*next, *size, format, ## arg); \
 		*size -= s_len; *next += s_len; \
 	} while (0);


 static void ohci_dump_intr_mask (
 	struct ohci_hcd *ohci,
 	char *label,
 	u32 mask,
 	char **next,
 	unsigned *size)
 {
 	ohci_dbg_sw (ohci, next, size, "%s 0x%08x%s%s%s%s%s%s%s%s%s\n",
 		label,
 		mask,
 		(mask & OHCI_INTR_MIE) ? " MIE" : "",
 		(mask & OHCI_INTR_OC) ? " OC" : "",
 		(mask & OHCI_INTR_RHSC) ? " RHSC" : "",
 		(mask & OHCI_INTR_FNO) ? " FNO" : "",
 		(mask & OHCI_INTR_UE) ? " UE" : "",
 		(mask & OHCI_INTR_RD) ? " RD" : "",
 		(mask & OHCI_INTR_SF) ? " SF" : "",
 		(mask & OHCI_INTR_WDH) ? " WDH" : "",
 		(mask & OHCI_INTR_SO) ? " SO" : ""
 		);
 }

 static void maybe_print_eds (
 	struct ohci_hcd *ohci,
 	char *label,
 	u32 value,
 	char **next,
 	unsigned *size)
 {
 	if (value)
 		ohci_dbg_sw (ohci, next, size, "%s %08x\n", label, value);
 }

 static char *hcfs2string (int state)
 {
 	switch (state) {
 		case OHCI_USB_RESET:	return "reset";
 		case OHCI_USB_RESUME:	return "resume";
 		case OHCI_USB_OPER:	return "operational";
 		case OHCI_USB_SUSPEND:	return "suspend";
 	}
 	return "?";
 }

 static const char *rh_state_string(struct ohci_hcd *ohci)
 {
 	switch (ohci->rh_state) {
 	case OHCI_RH_HALTED:
 		return "halted";
 	case OHCI_RH_SUSPENDED:
 		return "suspended";
 	case OHCI_RH_RUNNING:
 		return "running";
 	}
 	return "?";
 }

 // dump control and status registers
 static void
 ohci_dump_status (struct ohci_hcd *controller, char **next, unsigned *size)
 {
 	struct ohci_regs __iomem *regs = controller->regs;
 	u32			temp;

 	temp = ohci_readl (controller, &regs->revision) & 0xff;
 	ohci_dbg_sw (controller, next, size,
 		"OHCI %d.%d, %s legacy support registers, rh state %s\n",
 		0x03 & (temp >> 4), (temp & 0x0f),
 		(temp & 0x0100) ? "with" : "NO",
 		rh_state_string(controller));

 	temp = ohci_readl (controller, &regs->control);
 	ohci_dbg_sw (controller, next, size,
 		"control 0x%03x%s%s%s HCFS=%s%s%s%s%s CBSR=%d\n",
 		temp,
 		(temp & OHCI_CTRL_RWE) ? " RWE" : "",
 		(temp & OHCI_CTRL_RWC) ? " RWC" : "",
 		(temp & OHCI_CTRL_IR) ? " IR" : "",
 		hcfs2string (temp & OHCI_CTRL_HCFS),
 		(temp & OHCI_CTRL_BLE) ? " BLE" : "",
 		(temp & OHCI_CTRL_CLE) ? " CLE" : "",
 		(temp & OHCI_CTRL_IE) ? " IE" : "",
 		(temp & OHCI_CTRL_PLE) ? " PLE" : "",
 		temp & OHCI_CTRL_CBSR
 		);

 	temp = ohci_readl (controller, &regs->cmdstatus);
 	ohci_dbg_sw (controller, next, size,
 		"cmdstatus 0x%05x SOC=%d%s%s%s%s\n", temp,
 		(temp & OHCI_SOC) >> 16,
 		(temp & OHCI_OCR) ? " OCR" : "",
 		(temp & OHCI_BLF) ? " BLF" : "",
 		(temp & OHCI_CLF) ? " CLF" : "",
 		(temp & OHCI_HCR) ? " HCR" : ""
 		);

 	ohci_dump_intr_mask (controller, "intrstatus",
 			ohci_readl (controller, &regs->intrstatus),
 			next, size);
 	ohci_dump_intr_mask (controller, "intrenable",
 			ohci_readl (controller, &regs->intrenable),
 			next, size);
 	// intrdisable always same as intrenable

 	maybe_print_eds (controller, "ed_periodcurrent",
 			ohci_readl (controller, &regs->ed_periodcurrent),
 			next, size);

 	maybe_print_eds (controller, "ed_controlhead",
 			ohci_readl (controller, &regs->ed_controlhead),
 			next, size);
 	maybe_print_eds (controller, "ed_controlcurrent",
 			ohci_readl (controller, &regs->ed_controlcurrent),
 			next, size);

 	maybe_print_eds (controller, "ed_bulkhead",
 			ohci_readl (controller, &regs->ed_bulkhead),
 			next, size);
 	maybe_print_eds (controller, "ed_bulkcurrent",
 			ohci_readl (controller, &regs->ed_bulkcurrent),
 			next, size);

 	maybe_print_eds (controller, "donehead",
 			ohci_readl (controller, &regs->donehead), next, size);
 }

 #define dbg_port_sw(hc,num,value,next,size) \
 	ohci_dbg_sw (hc, next, size, \
 		"roothub.portstatus [%d] " \
 		"0x%08x%s%s%s%s%s%s%s%s%s%s%s%s\n", \
 		num, temp, \
 		(temp & RH_PS_PRSC) ? " PRSC" : "", \
 		(temp & RH_PS_OCIC) ? " OCIC" : "", \
 		(temp & RH_PS_PSSC) ? " PSSC" : "", \
 		(temp & RH_PS_PESC) ? " PESC" : "", \
 		(temp & RH_PS_CSC) ? " CSC" : "", \
 		\
 		(temp & RH_PS_LSDA) ? " LSDA" : "", \
 		(temp & RH_PS_PPS) ? " PPS" : "", \
 		(temp & RH_PS_PRS) ? " PRS" : "", \
 		(temp & RH_PS_POCI) ? " POCI" : "", \
 		(temp & RH_PS_PSS) ? " PSS" : "", \
 		\
 		(temp & RH_PS_PES) ? " PES" : "", \
 		(temp & RH_PS_CCS) ? " CCS" : "" \
 		);


 static void
 ohci_dump_roothub (
 	struct ohci_hcd *controller,
 	int verbose,
 	char **next,
 	unsigned *size)
 {
 	u32			temp, i;

 	temp = roothub_a (controller);
 	if (temp == ~(u32)0)
 		return;

 	if (verbose) {
 		ohci_dbg_sw (controller, next, size,
 			"roothub.a %08x POTPGT=%d%s%s%s%s%s NDP=%d(%d)\n", temp,
 			((temp & RH_A_POTPGT) >> 24) & 0xff,
 			(temp & RH_A_NOCP) ? " NOCP" : "",
 			(temp & RH_A_OCPM) ? " OCPM" : "",
 			(temp & RH_A_DT) ? " DT" : "",
 			(temp & RH_A_NPS) ? " NPS" : "",
 			(temp & RH_A_PSM) ? " PSM" : "",
 			(temp & RH_A_NDP), controller->num_ports
 			);
 		temp = roothub_b (controller);
 		ohci_dbg_sw (controller, next, size,
 			"roothub.b %08x PPCM=%04x DR=%04x\n",
 			temp,
 			(temp & RH_B_PPCM) >> 16,
 			(temp & RH_B_DR)
 			);
 		temp = roothub_status (controller);
 		ohci_dbg_sw (controller, next, size,
 			"roothub.status %08x%s%s%s%s%s%s\n",
 			temp,
 			(temp & RH_HS_CRWE) ? " CRWE" : "",
 			(temp & RH_HS_OCIC) ? " OCIC" : "",
 			(temp & RH_HS_LPSC) ? " LPSC" : "",
 			(temp & RH_HS_DRWE) ? " DRWE" : "",
 			(temp & RH_HS_OCI) ? " OCI" : "",
 			(temp & RH_HS_LPS) ? " LPS" : ""
 			);
 	}

 	for (i = 0; i < controller->num_ports; i++) {
 		temp = roothub_portstatus (controller, i);
 		dbg_port_sw (controller, i, temp, next, size);
 	}
 }

 static void ohci_dump(struct ohci_hcd *controller)
 {
 	ohci_dbg (controller, "OHCI controller state\n");

 	// dumps some of the state we know about
 	ohci_dump_status (controller, NULL, NULL);
 	if (controller->hcca)
 		ohci_dbg (controller,
 			"hcca frame #%04x\n", ohci_frame_no(controller));
 	ohci_dump_roothub (controller, 1, NULL, NULL);
 }

 static const char data0 [] = "DATA0";
 static const char data1 [] = "DATA1";

 static void ohci_dump_td (const struct ohci_hcd *ohci, const char *label,
 		const struct td *td)
 {
 	u32	tmp = hc32_to_cpup (ohci, &td->hwINFO);

 	ohci_dbg (ohci, "%s td %pK%s; urb %pK index %d; hw next td %08x\n",
 		label, td,
 		(tmp & TD_DONE) ? " (DONE)" : "",
 		td->urb, td->index,
 		hc32_to_cpup (ohci, &td->hwNextTD));
 	if ((tmp & TD_ISO) == 0) {
 		const char	*toggle, *pid;
 		u32	cbp, be;

 		switch (tmp & TD_T) {
 		case TD_T_DATA0: toggle = data0; break;
 		case TD_T_DATA1: toggle = data1; break;
 		case TD_T_TOGGLE: toggle = "(CARRY)"; break;
 		default: toggle = "(?)"; break;
 		}
 		switch (tmp & TD_DP) {
 		case TD_DP_SETUP: pid = "SETUP"; break;
 		case TD_DP_IN: pid = "IN"; break;
 		case TD_DP_OUT: pid = "OUT"; break;
 		default: pid = "(bad pid)"; break;
 		}
 		ohci_dbg (ohci, "     info %08x CC=%x %s DI=%d %s %s\n", tmp,
 			TD_CC_GET(tmp), /* EC, */ toggle,
 			(tmp & TD_DI) >> 21, pid,
 			(tmp & TD_R) ? "R" : "");
 		cbp = hc32_to_cpup (ohci, &td->hwCBP);
 		be = hc32_to_cpup (ohci, &td->hwBE);
 		ohci_dbg (ohci, "     cbp %08x be %08x (len %d)\n", cbp, be,
 			cbp ? (be + 1 - cbp) : 0);
 	} else {
 		unsigned	i;
 		ohci_dbg (ohci, "  info %08x CC=%x FC=%d DI=%d SF=%04x\n", tmp,
 			TD_CC_GET(tmp),
 			(tmp >> 24) & 0x07,
 			(tmp & TD_DI) >> 21,
 			tmp & 0x0000ffff);
 		ohci_dbg (ohci, "  bp0 %08x be %08x\n",
 			hc32_to_cpup (ohci, &td->hwCBP) & ~0x0fff,
 			hc32_to_cpup (ohci, &td->hwBE));
 		for (i = 0; i < MAXPSW; i++) {
 			u16	psw = ohci_hwPSW (ohci, td, i);
 			int	cc = (psw >> 12) & 0x0f;
 			ohci_dbg (ohci, "    psw [%d] = %2x, CC=%x %s=%d\n", i,
 				psw, cc,
 				(cc >= 0x0e) ? "OFFSET" : "SIZE",
 				psw & 0x0fff);
 		}
 	}
 }

 /* caller MUST own hcd spinlock if verbose is set! */
 static void __maybe_unused
 ohci_dump_ed (const struct ohci_hcd *ohci, const char *label,
 		const struct ed *ed, int verbose)
 {
 	u32	tmp = hc32_to_cpu (ohci, ed->hwINFO);
 	char	*type = "";

 	ohci_dbg (ohci, "%s, ed %pK state 0x%x type %s; next ed %08x\n",
 		label,
 		ed, ed->state, edstring (ed->type),
 		hc32_to_cpup (ohci, &ed->hwNextED));
 	switch (tmp & (ED_IN|ED_OUT)) {
 	case ED_OUT: type = "-OUT"; break;
 	case ED_IN: type = "-IN"; break;
 	/* else from TDs ... control */
 	}
 	ohci_dbg (ohci,
 		"  info %08x MAX=%d%s%s%s%s EP=%d%s DEV=%d\n", tmp,
 		0x03ff & (tmp >> 16),
 		(tmp & ED_DEQUEUE) ? " DQ" : "",
 		(tmp & ED_ISO) ? " ISO" : "",
 		(tmp & ED_SKIP) ? " SKIP" : "",
 		(tmp & ED_LOWSPEED) ? " LOW" : "",
 		0x000f & (tmp >> 7),
 		type,
 		0x007f & tmp);
 	tmp = hc32_to_cpup (ohci, &ed->hwHeadP);
 	ohci_dbg (ohci, "  tds: head %08x %s%s tail %08x%s\n",
 		tmp,
 		(tmp & ED_C) ? data1 : data0,
 		(tmp & ED_H) ? " HALT" : "",
 		hc32_to_cpup (ohci, &ed->hwTailP),
 		verbose ? "" : " (not listing)");
 	if (verbose) {
 		struct list_head	*tmp;

 		/* use ed->td_list because HC concurrently modifies
 		 * hwNextTD as it accumulates ed_donelist.
 		 */
 		list_for_each (tmp, &ed->td_list) {
 			struct td		*td;
 			td = list_entry (tmp, struct td, td_list);
 			ohci_dump_td (ohci, "  ->", td);
 		}
 	}
 }

 /*-------------------------------------------------------------------------*/

 static int debug_async_open(struct inode *, struct file *);
 static int debug_periodic_open(struct inode *, struct file *);
 static int debug_registers_open(struct inode *, struct file *);
 static int debug_async_open(struct inode *, struct file *);
 static ssize_t debug_output(struct file*, char __user*, size_t, loff_t*);
 static int debug_close(struct inode *, struct file *);

 static const struct file_operations debug_async_fops = {
 	.owner		= THIS_MODULE,
 	.open		= debug_async_open,
 	.read		= debug_output,
 	.release	= debug_close,
 	.llseek		= default_llseek,
 };
 static const struct file_operations debug_periodic_fops = {
 	.owner		= THIS_MODULE,
 	.open		= debug_periodic_open,
 	.read		= debug_output,
 	.release	= debug_close,
 	.llseek		= default_llseek,
 };
 static const struct file_operations debug_registers_fops = {
 	.owner		= THIS_MODULE,
 	.open		= debug_registers_open,
 	.read		= debug_output,
 	.release	= debug_close,
 	.llseek		= default_llseek,
 };

 static struct dentry *ohci_debug_root;

 struct debug_buffer {
 	ssize_t (*fill_func)(struct debug_buffer *);	/* fill method */
 	struct ohci_hcd *ohci;
 	struct mutex mutex;	/* protect filling of buffer */
 	size_t count;		/* number of characters filled into buffer */
 	char *page;
 };

 static ssize_t
 show_list (struct ohci_hcd *ohci, char *buf, size_t count, struct ed *ed)
 {
 	unsigned		temp, size = count;

 	if (!ed)
 		return 0;

 	/* print first --> last */
 	while (ed->ed_prev)
 		ed = ed->ed_prev;

 	/* dump a snapshot of the bulk or control schedule */
 	while (ed) {
 		u32		info = hc32_to_cpu (ohci, ed->hwINFO);
 		u32		headp = hc32_to_cpu (ohci, ed->hwHeadP);
 		struct list_head *entry;
 		struct td	*td;

 		temp = scnprintf (buf, size,
 			"ed/%pK %cs dev%d ep%d%s max %d %08x%s%s %s",
 			ed,
 			(info & ED_LOWSPEED) ? 'l' : 'f',
 			info & 0x7f,
 			(info >> 7) & 0xf,
 			(info & ED_IN) ? "in" : "out",
 			0x03ff & (info >> 16),
 			info,
 			(info & ED_SKIP) ? " s" : "",
 			(headp & ED_H) ? " H" : "",
 			(headp & ED_C) ? data1 : data0);
 		size -= temp;
 		buf += temp;

 		list_for_each (entry, &ed->td_list) {
 			u32		cbp, be;

 			td = list_entry (entry, struct td, td_list);
 			info = hc32_to_cpup (ohci, &td->hwINFO);
 			cbp = hc32_to_cpup (ohci, &td->hwCBP);
 			be = hc32_to_cpup (ohci, &td->hwBE);
 			temp = scnprintf (buf, size,
 					"\n\ttd %pK %s %d cc=%x urb %pK (%08x)",
 					td,
 					({ char *pid;
 					switch (info & TD_DP) {
 					case TD_DP_SETUP: pid = "setup"; break;
 					case TD_DP_IN: pid = "in"; break;
 					case TD_DP_OUT: pid = "out"; break;
 					default: pid = "(?)"; break;
 					 } pid;}),
 					cbp ? (be + 1 - cbp) : 0,
 					TD_CC_GET (info), td->urb, info);
 			size -= temp;
 			buf += temp;
 		}

 		temp = scnprintf (buf, size, "\n");
 		size -= temp;
 		buf += temp;

 		ed = ed->ed_next;
 	}
 	return count - size;
 }

 static ssize_t fill_async_buffer(struct debug_buffer *buf)
 {
 	struct ohci_hcd		*ohci;
 	size_t			temp, size;
 	unsigned long		flags;

 	ohci = buf->ohci;
 	size = PAGE_SIZE;

 	/* display control and bulk lists together, for simplicity */
 	spin_lock_irqsave (&ohci->lock, flags);
 	temp = show_list(ohci, buf->page, size, ohci->ed_controltail);
 	temp += show_list(ohci, buf->page + temp, size - temp,
 			  ohci->ed_bulktail);
 	spin_unlock_irqrestore (&ohci->lock, flags);

 	return temp;
 }

 #define DBG_SCHED_LIMIT 64

 static ssize_t fill_periodic_buffer(struct debug_buffer *buf)
 {
 	struct ohci_hcd		*ohci;
 	struct ed		**seen, *ed;
 	unsigned long		flags;
 	unsigned		temp, size, seen_count;
 	char			*next;
 	unsigned		i;

 	seen = kmalloc(DBG_SCHED_LIMIT * sizeof *seen, GFP_ATOMIC);
 	if (!seen)
 		return 0;
 	seen_count = 0;

 	ohci = buf->ohci;
 	next = buf->page;
 	size = PAGE_SIZE;

 	temp = scnprintf (next, size, "size = %d\n", NUM_INTS);
 	size -= temp;
 	next += temp;

 	/* dump a snapshot of the periodic schedule (and load) */
 	spin_lock_irqsave (&ohci->lock, flags);
 	for (i = 0; i < NUM_INTS; i++) {
 		ed = ohci->periodic[i];
 		if (!ed)
 			continue;

 		temp = scnprintf (next, size, "%2d [%3d]:", i, ohci->load [i]);
 		size -= temp;
 		next += temp;

 		do {
 			temp = scnprintf (next, size, " ed%d/%pK",
 				ed->interval, ed);
 			size -= temp;
 			next += temp;
 			for (temp = 0; temp < seen_count; temp++) {
 				if (seen [temp] == ed)
 					break;
 			}

 			/* show more info the first time around */
 			if (temp == seen_count) {
 				u32	info = hc32_to_cpu (ohci, ed->hwINFO);
 				struct list_head	*entry;
 				unsigned		qlen = 0;

 				/* qlen measured here in TDs, not urbs */
 				list_for_each (entry, &ed->td_list)
 					qlen++;

 				temp = scnprintf (next, size,
 					" (%cs dev%d ep%d%s-%s qlen %u"
 					" max %d %08x%s%s)",
 					(info & ED_LOWSPEED) ? 'l' : 'f',
 					info & 0x7f,
 					(info >> 7) & 0xf,
 					(info & ED_IN) ? "in" : "out",
 					(info & ED_ISO) ? "iso" : "int",
 					qlen,
 					0x03ff & (info >> 16),
 					info,
 					(info & ED_SKIP) ? " K" : "",
 					(ed->hwHeadP &
 						cpu_to_hc32(ohci, ED_H)) ?
 							" H" : "");
 				size -= temp;
 				next += temp;

 				if (seen_count < DBG_SCHED_LIMIT)
 					seen [seen_count++] = ed;

 				ed = ed->ed_next;

 			} else {
 				/* we've seen it and what's after */
 				temp = 0;
 				ed = NULL;
 			}

 		} while (ed);

 		temp = scnprintf (next, size, "\n");
 		size -= temp;
 		next += temp;
 	}
 	spin_unlock_irqrestore (&ohci->lock, flags);
 	kfree (seen);

 	return PAGE_SIZE - size;
 }
 #undef DBG_SCHED_LIMIT

 static ssize_t fill_registers_buffer(struct debug_buffer *buf)
 {
 	struct usb_hcd		*hcd;
 	struct ohci_hcd		*ohci;
 	struct ohci_regs __iomem *regs;
 	unsigned long		flags;
 	unsigned		temp, size;
 	char			*next;
 	u32			rdata;

 	ohci = buf->ohci;
 	hcd = ohci_to_hcd(ohci);
 	regs = ohci->regs;
 	next = buf->page;
 	size = PAGE_SIZE;

 	spin_lock_irqsave (&ohci->lock, flags);

 	/* dump driver info, then registers in spec order */

 	ohci_dbg_nosw(ohci, &next, &size,
 		"bus %s, device %s\n"
 		"%s\n"
 		"%s\n",
 		hcd->self.controller->bus->name,
 		dev_name(hcd->self.controller),
 		hcd->product_desc,
 		hcd_name);

 	if (!HCD_HW_ACCESSIBLE(hcd)) {
 		size -= scnprintf (next, size,
 			"SUSPENDED (no register access)\n");
 		goto done;
 	}

 	ohci_dump_status(ohci, &next, &size);

 	/* hcca */
 	if (ohci->hcca)
 		ohci_dbg_nosw(ohci, &next, &size,
 			"hcca frame 0x%04x\n", ohci_frame_no(ohci));

 	/* other registers mostly affect frame timings */
 	rdata = ohci_readl (ohci, &regs->fminterval);
 	temp = scnprintf (next, size,
 			"fmintvl 0x%08x %sFSMPS=0x%04x FI=0x%04x\n",
 			rdata, (rdata >> 31) ? "FIT " : "",
 			(rdata >> 16) & 0xefff, rdata & 0xffff);
 	size -= temp;
 	next += temp;

 	rdata = ohci_readl (ohci, &regs->fmremaining);
 	temp = scnprintf (next, size, "fmremaining 0x%08x %sFR=0x%04x\n",
 			rdata, (rdata >> 31) ? "FRT " : "",
 			rdata & 0x3fff);
 	size -= temp;
 	next += temp;

 	rdata = ohci_readl (ohci, &regs->periodicstart);
 	temp = scnprintf (next, size, "periodicstart 0x%04x\n",
 			rdata & 0x3fff);
 	size -= temp;
 	next += temp;

 	rdata = ohci_readl (ohci, &regs->lsthresh);
 	temp = scnprintf (next, size, "lsthresh 0x%04x\n",
 			rdata & 0x3fff);
 	size -= temp;
 	next += temp;

 	temp = scnprintf (next, size, "hub poll timer %s\n",
 			HCD_POLL_RH(ohci_to_hcd(ohci)) ? "ON" : "off");
 	size -= temp;
 	next += temp;

 	/* roothub */
 	ohci_dump_roothub (ohci, 1, &next, &size);

 done:
 	spin_unlock_irqrestore (&ohci->lock, flags);

 	return PAGE_SIZE - size;
 }

 static struct debug_buffer *alloc_buffer(struct ohci_hcd *ohci,
 				ssize_t (*fill_func)(struct debug_buffer *))
 {
 	struct debug_buffer *buf;

 	buf = kzalloc(sizeof(struct debug_buffer), GFP_KERNEL);

 	if (buf) {
 		buf->ohci = ohci;
 		buf->fill_func = fill_func;
 		mutex_init(&buf->mutex);
 	}

 	return buf;
 }

 static int fill_buffer(struct debug_buffer *buf)
 {
 	int ret = 0;

 	if (!buf->page)
 		buf->page = (char *)get_zeroed_page(GFP_KERNEL);

 	if (!buf->page) {
 		ret = -ENOMEM;
 		goto out;
 	}

 	ret = buf->fill_func(buf);

 	if (ret >= 0) {
 		buf->count = ret;
 		ret = 0;
 	}

 out:
 	return ret;
 }

 static ssize_t debug_output(struct file *file, char __user *user_buf,
 			size_t len, loff_t *offset)
 {
 	struct debug_buffer *buf = file->private_data;
 	int ret = 0;

 	mutex_lock(&buf->mutex);
 	if (buf->count == 0) {
 		ret = fill_buffer(buf);
 		if (ret != 0) {
 			mutex_unlock(&buf->mutex);
 			goto out;
 		}
 	}
 	mutex_unlock(&buf->mutex);

 	ret = simple_read_from_buffer(user_buf, len, offset,
 				      buf->page, buf->count);

 out:
 	return ret;

 }

 static int debug_close(struct inode *inode, struct file *file)
 {
 	struct debug_buffer *buf = file->private_data;

 	if (buf) {
 		if (buf->page)
 			free_page((unsigned long)buf->page);
 		kfree(buf);
 	}

 	return 0;
 }
 static int debug_async_open(struct inode *inode, struct file *file)
 {
 	file->private_data = alloc_buffer(inode->i_private, fill_async_buffer);

 	return file->private_data ? 0 : -ENOMEM;
 }

 static int debug_periodic_open(struct inode *inode, struct file *file)
 {
 	file->private_data = alloc_buffer(inode->i_private,
 					  fill_periodic_buffer);

 	return file->private_data ? 0 : -ENOMEM;
 }

 static int debug_registers_open(struct inode *inode, struct file *file)
 {
 	file->private_data = alloc_buffer(inode->i_private,
 					  fill_registers_buffer);

 	return file->private_data ? 0 : -ENOMEM;
 }
 static inline void create_debug_files (struct ohci_hcd *ohci)
 {
 	struct usb_bus *bus = &ohci_to_hcd(ohci)->self;

 	ohci->debug_dir = debugfs_create_dir(bus->bus_name, ohci_debug_root);
 	if (!ohci->debug_dir)
 		goto dir_error;

 	ohci->debug_async = debugfs_create_file("async", S_IRUGO,
 						ohci->debug_dir, ohci,
 						&debug_async_fops);
 	if (!ohci->debug_async)
 		goto async_error;

 	ohci->debug_periodic = debugfs_create_file("periodic", S_IRUGO,
 						   ohci->debug_dir, ohci,
 						   &debug_periodic_fops);
 	if (!ohci->debug_periodic)
 		goto periodic_error;

 	ohci->debug_registers = debugfs_create_file("registers", S_IRUGO,
 						    ohci->debug_dir, ohci,
 						    &debug_registers_fops);
 	if (!ohci->debug_registers)
 		goto registers_error;

 	ohci_dbg (ohci, "created debug files\n");
 	return;

 registers_error:
 	debugfs_remove(ohci->debug_periodic);
 periodic_error:
 	debugfs_remove(ohci->debug_async);
 async_error:
 	debugfs_remove(ohci->debug_dir);
 dir_error:
 	ohci->debug_periodic = NULL;
 	ohci->debug_async = NULL;
 	ohci->debug_dir = NULL;
 }

 static inline void remove_debug_files (struct ohci_hcd *ohci)
 {
 	debugfs_remove(ohci->debug_registers);
 	debugfs_remove(ohci->debug_periodic);
 	debugfs_remove(ohci->debug_async);
 	debugfs_remove(ohci->debug_dir);
 }

 /*-------------------------------------------------------------------------*/
	/*
	* OHCI HCD (Host Controller Driver) for USB.
	*
	* (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
	* (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
	*
	* This file is licenced under the GPL.
	*/

	/-------------------------------------------------------------------------/

	#define edstring(ed_type) ({ char *temp; \
	switch (ed_type) { \
	case PIPE_CONTROL: temp = "ctrl"; break; \
	case PIPE_BULK: temp = "bulk"; break; \
	case PIPE_INTERRUPT: temp = "intr"; break; \
	default: temp = "isoc"; break; \
	} temp;})
	#define pipestring(pipe) edstring(usb_pipetype(pipe))


	#define ohci_dbg_sw(ohci, next, size, format, arg...) \
	do { \
	if (next != NULL) { \
	unsigned s_len; \
	s_len = scnprintf (next, size, format, ## arg ); \
	size -= s_len; next += s_len; \
	} else \
	ohci_dbg(ohci,format, ## arg ); \
	} while (0);

	/* Version for use where "next" is the address of a local variable */
	#define ohci_dbg_nosw(ohci, next, size, format, arg...) \
	do { \
	unsigned s_len; \
	s_len = scnprintf(next, size, format, ## arg); \
	size -= s_len; next += s_len; \
	} while (0);


	static void ohci_dump_intr_mask (
	struct ohci_hcd *ohci,
	char *label,
	u32 mask,
	char **next,
	unsigned *size)
	{
	ohci_dbg_sw (ohci, next, size, "%s 0x%08x%s%s%s%s%s%s%s%s%s\n",
	label,
	mask,
	(mask & OHCI_INTR_MIE) ? " MIE" : "",
	(mask & OHCI_INTR_OC) ? " OC" : "",
	(mask & OHCI_INTR_RHSC) ? " RHSC" : "",
	(mask & OHCI_INTR_FNO) ? " FNO" : "",
	(mask & OHCI_INTR_UE) ? " UE" : "",
	(mask & OHCI_INTR_RD) ? " RD" : "",
	(mask & OHCI_INTR_SF) ? " SF" : "",
	(mask & OHCI_INTR_WDH) ? " WDH" : "",
	(mask & OHCI_INTR_SO) ? " SO" : ""
	);
	}

	static void maybe_print_eds (
	struct ohci_hcd *ohci,
	char *label,
	u32 value,
	char **next,
	unsigned *size)
	{
	if (value)
	ohci_dbg_sw (ohci, next, size, "%s %08x\n", label, value);
	}

	static char *hcfs2string (int state)
	{
	switch (state) {
	case OHCI_USB_RESET: return "reset";
	case OHCI_USB_RESUME: return "resume";
	case OHCI_USB_OPER: return "operational";
	case OHCI_USB_SUSPEND: return "suspend";
	}
	return "?";
	}

	static const char rh_state_string(struct ohci_hcd ohci)
	{
	switch (ohci->rh_state) {
	case OHCI_RH_HALTED:
	return "halted";
	case OHCI_RH_SUSPENDED:
	return "suspended";
	case OHCI_RH_RUNNING:
	return "running";
	}
	return "?";
	}

	// dump control and status registers
	static void
	ohci_dump_status (struct ohci_hcd controller, char next, unsigned size)
	{
	struct ohci_regs __iomem *regs = controller->regs;
	u32 temp;

	temp = ohci_readl (controller, &regs->revision) & 0xff;
	ohci_dbg_sw (controller, next, size,
	"OHCI %d.%d, %s legacy support registers, rh state %s\n",
	0x03 & (temp >> 4), (temp & 0x0f),
	(temp & 0x0100) ? "with" : "NO",
	rh_state_string(controller));

	temp = ohci_readl (controller, &regs->control);
	ohci_dbg_sw (controller, next, size,
	"control 0x%03x%s%s%s HCFS=%s%s%s%s%s CBSR=%d\n",
	temp,
	(temp & OHCI_CTRL_RWE) ? " RWE" : "",
	(temp & OHCI_CTRL_RWC) ? " RWC" : "",
	(temp & OHCI_CTRL_IR) ? " IR" : "",
	hcfs2string (temp & OHCI_CTRL_HCFS),
	(temp & OHCI_CTRL_BLE) ? " BLE" : "",
	(temp & OHCI_CTRL_CLE) ? " CLE" : "",
	(temp & OHCI_CTRL_IE) ? " IE" : "",
	(temp & OHCI_CTRL_PLE) ? " PLE" : "",
	temp & OHCI_CTRL_CBSR
	);

	temp = ohci_readl (controller, &regs->cmdstatus);
	ohci_dbg_sw (controller, next, size,
	"cmdstatus 0x%05x SOC=%d%s%s%s%s\n", temp,
	(temp & OHCI_SOC) >> 16,
	(temp & OHCI_OCR) ? " OCR" : "",
	(temp & OHCI_BLF) ? " BLF" : "",
	(temp & OHCI_CLF) ? " CLF" : "",
	(temp & OHCI_HCR) ? " HCR" : ""
	);

	ohci_dump_intr_mask (controller, "intrstatus",
	ohci_readl (controller, &regs->intrstatus),
	next, size);
	ohci_dump_intr_mask (controller, "intrenable",
	ohci_readl (controller, &regs->intrenable),
	next, size);
	// intrdisable always same as intrenable

	maybe_print_eds (controller, "ed_periodcurrent",
	ohci_readl (controller, &regs->ed_periodcurrent),
	next, size);

	maybe_print_eds (controller, "ed_controlhead",
	ohci_readl (controller, &regs->ed_controlhead),
	next, size);
	maybe_print_eds (controller, "ed_controlcurrent",
	ohci_readl (controller, &regs->ed_controlcurrent),
	next, size);

	maybe_print_eds (controller, "ed_bulkhead",
	ohci_readl (controller, &regs->ed_bulkhead),
	next, size);
	maybe_print_eds (controller, "ed_bulkcurrent",
	ohci_readl (controller, &regs->ed_bulkcurrent),
	next, size);

	maybe_print_eds (controller, "donehead",
	ohci_readl (controller, &regs->donehead), next, size);
	}

	#define dbg_port_sw(hc,num,value,next,size) \
	ohci_dbg_sw (hc, next, size, \
	"roothub.portstatus [%d] " \
	"0x%08x%s%s%s%s%s%s%s%s%s%s%s%s\n", \
	num, temp, \
	(temp & RH_PS_PRSC) ? " PRSC" : "", \
	(temp & RH_PS_OCIC) ? " OCIC" : "", \
	(temp & RH_PS_PSSC) ? " PSSC" : "", \
	(temp & RH_PS_PESC) ? " PESC" : "", \
	(temp & RH_PS_CSC) ? " CSC" : "", \
	\
	(temp & RH_PS_LSDA) ? " LSDA" : "", \
	(temp & RH_PS_PPS) ? " PPS" : "", \
	(temp & RH_PS_PRS) ? " PRS" : "", \
	(temp & RH_PS_POCI) ? " POCI" : "", \
	(temp & RH_PS_PSS) ? " PSS" : "", \
	\
	(temp & RH_PS_PES) ? " PES" : "", \
	(temp & RH_PS_CCS) ? " CCS" : "" \
	);


	static void
	ohci_dump_roothub (
	struct ohci_hcd *controller,
	int verbose,
	char **next,
	unsigned *size)
	{
	u32 temp, i;

	temp = roothub_a (controller);
	if (temp == ~(u32)0)
	return;

	if (verbose) {
	ohci_dbg_sw (controller, next, size,
	"roothub.a %08x POTPGT=%d%s%s%s%s%s NDP=%d(%d)\n", temp,
	((temp & RH_A_POTPGT) >> 24) & 0xff,
	(temp & RH_A_NOCP) ? " NOCP" : "",
	(temp & RH_A_OCPM) ? " OCPM" : "",
	(temp & RH_A_DT) ? " DT" : "",
	(temp & RH_A_NPS) ? " NPS" : "",
	(temp & RH_A_PSM) ? " PSM" : "",
	(temp & RH_A_NDP), controller->num_ports
	);
	temp = roothub_b (controller);
	ohci_dbg_sw (controller, next, size,
	"roothub.b %08x PPCM=%04x DR=%04x\n",
	temp,
	(temp & RH_B_PPCM) >> 16,
	(temp & RH_B_DR)
	);
	temp = roothub_status (controller);
	ohci_dbg_sw (controller, next, size,
	"roothub.status %08x%s%s%s%s%s%s\n",
	temp,
	(temp & RH_HS_CRWE) ? " CRWE" : "",
	(temp & RH_HS_OCIC) ? " OCIC" : "",
	(temp & RH_HS_LPSC) ? " LPSC" : "",
	(temp & RH_HS_DRWE) ? " DRWE" : "",
	(temp & RH_HS_OCI) ? " OCI" : "",
	(temp & RH_HS_LPS) ? " LPS" : ""
	);
	}

	for (i = 0; i < controller->num_ports; i++) {
	temp = roothub_portstatus (controller, i);
	dbg_port_sw (controller, i, temp, next, size);
	}
	}

	static void ohci_dump(struct ohci_hcd *controller)
	{
	ohci_dbg (controller, "OHCI controller state\n");

	// dumps some of the state we know about
	ohci_dump_status (controller, NULL, NULL);
	if (controller->hcca)
	ohci_dbg (controller,
	"hcca frame #%04x\n", ohci_frame_no(controller));
	ohci_dump_roothub (controller, 1, NULL, NULL);
	}

	static const char data0 [] = "DATA0";
	static const char data1 [] = "DATA1";

	static void ohci_dump_td (const struct ohci_hcd ohci, const char label,
	const struct td *td)
	{
	u32 tmp = hc32_to_cpup (ohci, &td->hwINFO);

	ohci_dbg (ohci, "%s td %pK%s; urb %pK index %d; hw next td %08x\n",
	label, td,
	(tmp & TD_DONE) ? " (DONE)" : "",
	td->urb, td->index,
	hc32_to_cpup (ohci, &td->hwNextTD));
	if ((tmp & TD_ISO) == 0) {
	const char toggle, pid;
	u32 cbp, be;

	switch (tmp & TD_T) {
	case TD_T_DATA0: toggle = data0; break;
	case TD_T_DATA1: toggle = data1; break;
	case TD_T_TOGGLE: toggle = "(CARRY)"; break;
	default: toggle = "(?)"; break;
	}
	switch (tmp & TD_DP) {
	case TD_DP_SETUP: pid = "SETUP"; break;
	case TD_DP_IN: pid = "IN"; break;
	case TD_DP_OUT: pid = "OUT"; break;
	default: pid = "(bad pid)"; break;
	}
	ohci_dbg (ohci, " info %08x CC=%x %s DI=%d %s %s\n", tmp,
	TD_CC_GET(tmp), /* EC, */ toggle,
	(tmp & TD_DI) >> 21, pid,
	(tmp & TD_R) ? "R" : "");
	cbp = hc32_to_cpup (ohci, &td->hwCBP);
	be = hc32_to_cpup (ohci, &td->hwBE);
	ohci_dbg (ohci, " cbp %08x be %08x (len %d)\n", cbp, be,
	cbp ? (be + 1 - cbp) : 0);
	} else {
	unsigned i;
	ohci_dbg (ohci, " info %08x CC=%x FC=%d DI=%d SF=%04x\n", tmp,
	TD_CC_GET(tmp),
	(tmp >> 24) & 0x07,
	(tmp & TD_DI) >> 21,
	tmp & 0x0000ffff);
	ohci_dbg (ohci, " bp0 %08x be %08x\n",
	hc32_to_cpup (ohci, &td->hwCBP) & ~0x0fff,
	hc32_to_cpup (ohci, &td->hwBE));
	for (i = 0; i < MAXPSW; i++) {
	u16 psw = ohci_hwPSW (ohci, td, i);
	int cc = (psw >> 12) & 0x0f;
	ohci_dbg (ohci, " psw [%d] = %2x, CC=%x %s=%d\n", i,
	psw, cc,
	(cc >= 0x0e) ? "OFFSET" : "SIZE",
	psw & 0x0fff);
	}
	}
	}

	/* caller MUST own hcd spinlock if verbose is set! */
	static void __maybe_unused
	ohci_dump_ed (const struct ohci_hcd ohci, const char label,
	const struct ed *ed, int verbose)
	{
	u32 tmp = hc32_to_cpu (ohci, ed->hwINFO);
	char *type = "";

	ohci_dbg (ohci, "%s, ed %pK state 0x%x type %s; next ed %08x\n",
	label,
	ed, ed->state, edstring (ed->type),
	hc32_to_cpup (ohci, &ed->hwNextED));
	switch (tmp & (ED_IN\|ED_OUT)) {
	case ED_OUT: type = "-OUT"; break;
	case ED_IN: type = "-IN"; break;
	/* else from TDs ... control */
	}
	ohci_dbg (ohci,
	" info %08x MAX=%d%s%s%s%s EP=%d%s DEV=%d\n", tmp,
	0x03ff & (tmp >> 16),
	(tmp & ED_DEQUEUE) ? " DQ" : "",
	(tmp & ED_ISO) ? " ISO" : "",
	(tmp & ED_SKIP) ? " SKIP" : "",
	(tmp & ED_LOWSPEED) ? " LOW" : "",
	0x000f & (tmp >> 7),
	type,
	0x007f & tmp);
	tmp = hc32_to_cpup (ohci, &ed->hwHeadP);
	ohci_dbg (ohci, " tds: head %08x %s%s tail %08x%s\n",
	tmp,
	(tmp & ED_C) ? data1 : data0,
	(tmp & ED_H) ? " HALT" : "",
	hc32_to_cpup (ohci, &ed->hwTailP),
	verbose ? "" : " (not listing)");
	if (verbose) {
	struct list_head *tmp;

	/* use ed->td_list because HC concurrently modifies
	* hwNextTD as it accumulates ed_donelist.
	*/
	list_for_each (tmp, &ed->td_list) {
	struct td *td;
	td = list_entry (tmp, struct td, td_list);
	ohci_dump_td (ohci, " ->", td);
	}
	}
	}

	/-------------------------------------------------------------------------/

	static int debug_async_open(struct inode , struct file );
	static int debug_periodic_open(struct inode , struct file );
	static int debug_registers_open(struct inode , struct file );
	static int debug_async_open(struct inode , struct file );
	static ssize_t debug_output(struct file, char __user, size_t, loff_t*);
	static int debug_close(struct inode , struct file );

	static const struct file_operations debug_async_fops = {
	.owner = THIS_MODULE,
	.open = debug_async_open,
	.read = debug_output,
	.release = debug_close,
	.llseek = default_llseek,
	};
	static const struct file_operations debug_periodic_fops = {
	.owner = THIS_MODULE,
	.open = debug_periodic_open,
	.read = debug_output,
	.release = debug_close,
	.llseek = default_llseek,
	};
	static const struct file_operations debug_registers_fops = {
	.owner = THIS_MODULE,
	.open = debug_registers_open,
	.read = debug_output,
	.release = debug_close,
	.llseek = default_llseek,
	};

	static struct dentry *ohci_debug_root;

	struct debug_buffer {
	ssize_t (fill_func)(struct debug_buffer ); /* fill method */
	struct ohci_hcd *ohci;
	struct mutex mutex; /* protect filling of buffer */
	size_t count; /* number of characters filled into buffer */
	char *page;
	};

	static ssize_t
	show_list (struct ohci_hcd ohci, char buf, size_t count, struct ed *ed)
	{
	unsigned temp, size = count;

	if (!ed)
	return 0;

	/* print first --> last */
	while (ed->ed_prev)
	ed = ed->ed_prev;

	/* dump a snapshot of the bulk or control schedule */
	while (ed) {
	u32 info = hc32_to_cpu (ohci, ed->hwINFO);
	u32 headp = hc32_to_cpu (ohci, ed->hwHeadP);
	struct list_head *entry;
	struct td *td;

	temp = scnprintf (buf, size,
	"ed/%pK %cs dev%d ep%d%s max %d %08x%s%s %s",
	ed,
	(info & ED_LOWSPEED) ? 'l' : 'f',
	info & 0x7f,
	(info >> 7) & 0xf,
	(info & ED_IN) ? "in" : "out",
	0x03ff & (info >> 16),
	info,
	(info & ED_SKIP) ? " s" : "",
	(headp & ED_H) ? " H" : "",
	(headp & ED_C) ? data1 : data0);
	size -= temp;
	buf += temp;

	list_for_each (entry, &ed->td_list) {
	u32 cbp, be;

	td = list_entry (entry, struct td, td_list);
	info = hc32_to_cpup (ohci, &td->hwINFO);
	cbp = hc32_to_cpup (ohci, &td->hwCBP);
	be = hc32_to_cpup (ohci, &td->hwBE);
	temp = scnprintf (buf, size,
	"\n\ttd %pK %s %d cc=%x urb %pK (%08x)",
	td,
	({ char *pid;
	switch (info & TD_DP) {
	case TD_DP_SETUP: pid = "setup"; break;
	case TD_DP_IN: pid = "in"; break;
	case TD_DP_OUT: pid = "out"; break;
	default: pid = "(?)"; break;
	} pid;}),
	cbp ? (be + 1 - cbp) : 0,
	TD_CC_GET (info), td->urb, info);
	size -= temp;
	buf += temp;
	}

	temp = scnprintf (buf, size, "\n");
	size -= temp;
	buf += temp;

	ed = ed->ed_next;
	}
	return count - size;
	}

	static ssize_t fill_async_buffer(struct debug_buffer *buf)
	{
	struct ohci_hcd *ohci;
	size_t temp, size;
	unsigned long flags;

	ohci = buf->ohci;
	size = PAGE_SIZE;

	/* display control and bulk lists together, for simplicity */
	spin_lock_irqsave (&ohci->lock, flags);
	temp = show_list(ohci, buf->page, size, ohci->ed_controltail);
	temp += show_list(ohci, buf->page + temp, size - temp,
	ohci->ed_bulktail);
	spin_unlock_irqrestore (&ohci->lock, flags);

	return temp;
	}

	#define DBG_SCHED_LIMIT 64

	static ssize_t fill_periodic_buffer(struct debug_buffer *buf)
	{
	struct ohci_hcd *ohci;
	struct ed *seen, ed;
	unsigned long flags;
	unsigned temp, size, seen_count;
	char *next;
	unsigned i;

	seen = kmalloc(DBG_SCHED_LIMIT * sizeof *seen, GFP_ATOMIC);
	if (!seen)
	return 0;
	seen_count = 0;

	ohci = buf->ohci;
	next = buf->page;
	size = PAGE_SIZE;

	temp = scnprintf (next, size, "size = %d\n", NUM_INTS);
	size -= temp;
	next += temp;

	/* dump a snapshot of the periodic schedule (and load) */
	spin_lock_irqsave (&ohci->lock, flags);
	for (i = 0; i < NUM_INTS; i++) {
	ed = ohci->periodic[i];
	if (!ed)
	continue;

	temp = scnprintf (next, size, "%2d [%3d]:", i, ohci->load [i]);
	size -= temp;
	next += temp;

	do {
	temp = scnprintf (next, size, " ed%d/%pK",
	ed->interval, ed);
	size -= temp;
	next += temp;
	for (temp = 0; temp < seen_count; temp++) {
	if (seen [temp] == ed)
	break;
	}

	/* show more info the first time around */
	if (temp == seen_count) {
	u32 info = hc32_to_cpu (ohci, ed->hwINFO);
	struct list_head *entry;
	unsigned qlen = 0;

	/* qlen measured here in TDs, not urbs */
	list_for_each (entry, &ed->td_list)
	qlen++;

	temp = scnprintf (next, size,
	" (%cs dev%d ep%d%s-%s qlen %u"
	" max %d %08x%s%s)",
	(info & ED_LOWSPEED) ? 'l' : 'f',
	info & 0x7f,
	(info >> 7) & 0xf,
	(info & ED_IN) ? "in" : "out",
	(info & ED_ISO) ? "iso" : "int",
	qlen,
	0x03ff & (info >> 16),
	info,
	(info & ED_SKIP) ? " K" : "",
	(ed->hwHeadP &
	cpu_to_hc32(ohci, ED_H)) ?
	" H" : "");
	size -= temp;
	next += temp;

	if (seen_count < DBG_SCHED_LIMIT)
	seen [seen_count++] = ed;

	ed = ed->ed_next;

	} else {
	/* we've seen it and what's after */
	temp = 0;
	ed = NULL;
	}

	} while (ed);

	temp = scnprintf (next, size, "\n");
	size -= temp;
	next += temp;
	}
	spin_unlock_irqrestore (&ohci->lock, flags);
	kfree (seen);

	return PAGE_SIZE - size;
	}
	#undef DBG_SCHED_LIMIT

	static ssize_t fill_registers_buffer(struct debug_buffer *buf)
	{
	struct usb_hcd *hcd;
	struct ohci_hcd *ohci;
	struct ohci_regs __iomem *regs;
	unsigned long flags;
	unsigned temp, size;
	char *next;
	u32 rdata;

	ohci = buf->ohci;
	hcd = ohci_to_hcd(ohci);
	regs = ohci->regs;
	next = buf->page;
	size = PAGE_SIZE;

	spin_lock_irqsave (&ohci->lock, flags);

	/* dump driver info, then registers in spec order */

	ohci_dbg_nosw(ohci, &next, &size,
	"bus %s, device %s\n"
	"%s\n"
	"%s\n",
	hcd->self.controller->bus->name,
	dev_name(hcd->self.controller),
	hcd->product_desc,
	hcd_name);

	if (!HCD_HW_ACCESSIBLE(hcd)) {
	size -= scnprintf (next, size,
	"SUSPENDED (no register access)\n");
	goto done;
	}

	ohci_dump_status(ohci, &next, &size);

	/* hcca */
	if (ohci->hcca)
	ohci_dbg_nosw(ohci, &next, &size,
	"hcca frame 0x%04x\n", ohci_frame_no(ohci));

	/* other registers mostly affect frame timings */
	rdata = ohci_readl (ohci, &regs->fminterval);
	temp = scnprintf (next, size,
	"fmintvl 0x%08x %sFSMPS=0x%04x FI=0x%04x\n",
	rdata, (rdata >> 31) ? "FIT " : "",
	(rdata >> 16) & 0xefff, rdata & 0xffff);
	size -= temp;
	next += temp;

	rdata = ohci_readl (ohci, &regs->fmremaining);
	temp = scnprintf (next, size, "fmremaining 0x%08x %sFR=0x%04x\n",
	rdata, (rdata >> 31) ? "FRT " : "",
	rdata & 0x3fff);
	size -= temp;
	next += temp;

	rdata = ohci_readl (ohci, &regs->periodicstart);
	temp = scnprintf (next, size, "periodicstart 0x%04x\n",
	rdata & 0x3fff);
	size -= temp;
	next += temp;

	rdata = ohci_readl (ohci, &regs->lsthresh);
	temp = scnprintf (next, size, "lsthresh 0x%04x\n",
	rdata & 0x3fff);
	size -= temp;
	next += temp;

	temp = scnprintf (next, size, "hub poll timer %s\n",
	HCD_POLL_RH(ohci_to_hcd(ohci)) ? "ON" : "off");
	size -= temp;
	next += temp;

	/* roothub */
	ohci_dump_roothub (ohci, 1, &next, &size);

	done:
	spin_unlock_irqrestore (&ohci->lock, flags);

	return PAGE_SIZE - size;
	}

	static struct debug_buffer alloc_buffer(struct ohci_hcd ohci,
	ssize_t (fill_func)(struct debug_buffer ))
	{
	struct debug_buffer *buf;

	buf = kzalloc(sizeof(struct debug_buffer), GFP_KERNEL);

	if (buf) {
	buf->ohci = ohci;
	buf->fill_func = fill_func;
	mutex_init(&buf->mutex);
	}

	return buf;
	}

	static int fill_buffer(struct debug_buffer *buf)
	{
	int ret = 0;

	if (!buf->page)
	buf->page = (char *)get_zeroed_page(GFP_KERNEL);

	if (!buf->page) {
	ret = -ENOMEM;
	goto out;
	}

	ret = buf->fill_func(buf);

	if (ret >= 0) {
	buf->count = ret;
	ret = 0;
	}

	out:
	return ret;
	}

	static ssize_t debug_output(struct file file, char __user user_buf,
	size_t len, loff_t *offset)
	{
	struct debug_buffer *buf = file->private_data;
	int ret = 0;

	mutex_lock(&buf->mutex);
	if (buf->count == 0) {
	ret = fill_buffer(buf);
	if (ret != 0) {
	mutex_unlock(&buf->mutex);
	goto out;
	}
	}
	mutex_unlock(&buf->mutex);

	ret = simple_read_from_buffer(user_buf, len, offset,
	buf->page, buf->count);

	out:
	return ret;

	}

	static int debug_close(struct inode inode, struct file file)
	{
	struct debug_buffer *buf = file->private_data;

	if (buf) {
	if (buf->page)
	free_page((unsigned long)buf->page);
	kfree(buf);
	}

	return 0;
	}
	static int debug_async_open(struct inode inode, struct file file)
	{
	file->private_data = alloc_buffer(inode->i_private, fill_async_buffer);

	return file->private_data ? 0 : -ENOMEM;
	}

	static int debug_periodic_open(struct inode inode, struct file file)
	{
	file->private_data = alloc_buffer(inode->i_private,
	fill_periodic_buffer);

	return file->private_data ? 0 : -ENOMEM;
	}

	static int debug_registers_open(struct inode inode, struct file file)
	{
	file->private_data = alloc_buffer(inode->i_private,
	fill_registers_buffer);

	return file->private_data ? 0 : -ENOMEM;
	}
	static inline void create_debug_files (struct ohci_hcd *ohci)
	{
	struct usb_bus *bus = &ohci_to_hcd(ohci)->self;

	ohci->debug_dir = debugfs_create_dir(bus->bus_name, ohci_debug_root);
	if (!ohci->debug_dir)
	goto dir_error;

	ohci->debug_async = debugfs_create_file("async", S_IRUGO,
	ohci->debug_dir, ohci,
	&debug_async_fops);
	if (!ohci->debug_async)
	goto async_error;

	ohci->debug_periodic = debugfs_create_file("periodic", S_IRUGO,
	ohci->debug_dir, ohci,
	&debug_periodic_fops);
	if (!ohci->debug_periodic)
	goto periodic_error;

	ohci->debug_registers = debugfs_create_file("registers", S_IRUGO,
	ohci->debug_dir, ohci,
	&debug_registers_fops);
	if (!ohci->debug_registers)
	goto registers_error;

	ohci_dbg (ohci, "created debug files\n");
	return;

	registers_error:
	debugfs_remove(ohci->debug_periodic);
	periodic_error:
	debugfs_remove(ohci->debug_async);
	async_error:
	debugfs_remove(ohci->debug_dir);
	dir_error:
	ohci->debug_periodic = NULL;
	ohci->debug_async = NULL;
	ohci->debug_dir = NULL;
	}

	static inline void remove_debug_files (struct ohci_hcd *ohci)
	{
	debugfs_remove(ohci->debug_registers);
	debugfs_remove(ohci->debug_periodic);
	debugfs_remove(ohci->debug_async);
	debugfs_remove(ohci->debug_dir);
	}

	/-------------------------------------------------------------------------/