usb host: Oxford OXU210HP HCD driver.

This driver implements the support for Oxford OXU210HP USB high-speed host,
no peripheral nor OTG.

Signed-off-by: Rodolfo Giometti <giometti@linux.it>
Cc: Kan Liu <kan.k.liu@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/host/oxu210hp-hcd.c b/drivers/usb/host/oxu210hp-hcd.c
new file mode 100644
index 0000000..251123c
--- /dev/null
+++ b/drivers/usb/host/oxu210hp-hcd.c
@@ -0,0 +1,3985 @@
+/*
+ * Copyright (c) 2008 Rodolfo Giometti <giometti@linux.it>
+ * Copyright (c) 2008 Eurotech S.p.A. <info@eurtech.it>
+ *
+ * This code is *strongly* based on EHCI-HCD code by David Brownell since
+ * the chip is a quasi-EHCI compatible.
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/dmapool.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/reboot.h>
+#include <linux/usb.h>
+#include <linux/moduleparam.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+
+#include "../core/hcd.h"
+
+#include <asm/irq.h>
+#include <asm/system.h>
+#include <asm/unaligned.h>
+
+#include <linux/irq.h>
+#include <linux/platform_device.h>
+
+#include "oxu210hp.h"
+
+#define DRIVER_VERSION "0.0.50"
+
+/*
+ * Main defines
+ */
+
+#define oxu_dbg(oxu, fmt, args...) \
+		dev_dbg(oxu_to_hcd(oxu)->self.controller , fmt , ## args)
+#define oxu_err(oxu, fmt, args...) \
+		dev_err(oxu_to_hcd(oxu)->self.controller , fmt , ## args)
+#define oxu_info(oxu, fmt, args...) \
+		dev_info(oxu_to_hcd(oxu)->self.controller , fmt , ## args)
+
+static inline struct usb_hcd *oxu_to_hcd(struct oxu_hcd *oxu)
+{
+	return container_of((void *) oxu, struct usb_hcd, hcd_priv);
+}
+
+static inline struct oxu_hcd *hcd_to_oxu(struct usb_hcd *hcd)
+{
+	return (struct oxu_hcd *) (hcd->hcd_priv);
+}
+
+/*
+ * Debug stuff
+ */
+
+#undef OXU_URB_TRACE
+#undef OXU_VERBOSE_DEBUG
+
+#ifdef OXU_VERBOSE_DEBUG
+#define oxu_vdbg			oxu_dbg
+#else
+#define oxu_vdbg(oxu, fmt, args...)	/* Nop */
+#endif
+
+#ifdef DEBUG
+
+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";	/* low speed */
+		break;
+	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 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(oxu, label, status) { \
+	char _buf[80]; \
+	dbg_status_buf(_buf, sizeof _buf, label, status); \
+	oxu_dbg(oxu, "%s\n", _buf); \
+}
+
+#define dbg_cmd(oxu, label, command) { \
+	char _buf[80]; \
+	dbg_command_buf(_buf, sizeof _buf, label, command); \
+	oxu_dbg(oxu, "%s\n", _buf); \
+}
+
+#define dbg_port(oxu, label, port, status) { \
+	char _buf[80]; \
+	dbg_port_buf(_buf, sizeof _buf, label, port, status); \
+	oxu_dbg(oxu, "%s\n", _buf); \
+}
+
+/*
+ * Module parameters
+ */
+
+/* Initial IRQ latency: faster than hw default */
+static int log2_irq_thresh;			/* 0 to 6 */
+module_param(log2_irq_thresh, int, S_IRUGO);
+MODULE_PARM_DESC(log2_irq_thresh, "log2 IRQ latency, 1-64 microframes");
+
+/* Initial park setting: slower than hw default */
+static unsigned park;
+module_param(park, uint, S_IRUGO);
+MODULE_PARM_DESC(park, "park setting; 1-3 back-to-back async packets");
+
+/* For flakey hardware, ignore overcurrent indicators */
+static int ignore_oc;
+module_param(ignore_oc, bool, S_IRUGO);
+MODULE_PARM_DESC(ignore_oc, "ignore bogus hardware overcurrent indications");
+
+
+static void ehci_work(struct oxu_hcd *oxu);
+static int oxu_hub_control(struct usb_hcd *hcd,
+				u16 typeReq, u16 wValue, u16 wIndex,
+				char *buf, u16 wLength);
+
+/*
+ * Local functions
+ */
+
+/* Low level read/write registers functions */
+static inline u32 oxu_readl(void *base, u32 reg)
+{
+	return readl(base + reg);
+}
+
+static inline void oxu_writel(void *base, u32 reg, u32 val)
+{
+	writel(val, base + reg);
+}
+
+static inline void timer_action_done(struct oxu_hcd *oxu,
+					enum ehci_timer_action action)
+{
+	clear_bit(action, &oxu->actions);
+}
+
+static inline void timer_action(struct oxu_hcd *oxu,
+					enum ehci_timer_action action)
+{
+	if (!test_and_set_bit(action, &oxu->actions)) {
+		unsigned long t;
+
+		switch (action) {
+		case TIMER_IAA_WATCHDOG:
+			t = EHCI_IAA_JIFFIES;
+			break;
+		case TIMER_IO_WATCHDOG:
+			t = EHCI_IO_JIFFIES;
+			break;
+		case TIMER_ASYNC_OFF:
+			t = EHCI_ASYNC_JIFFIES;
+			break;
+		case TIMER_ASYNC_SHRINK:
+		default:
+			t = EHCI_SHRINK_JIFFIES;
+			break;
+		}
+		t += jiffies;
+		/* all timings except IAA watchdog can be overridden.
+		 * async queue SHRINK often precedes IAA.  while it's ready
+		 * to go OFF neither can matter, and afterwards the IO
+		 * watchdog stops unless there's still periodic traffic.
+		 */
+		if (action != TIMER_IAA_WATCHDOG
+				&& t > oxu->watchdog.expires
+				&& timer_pending(&oxu->watchdog))
+			return;
+		mod_timer(&oxu->watchdog, t);
+	}
+}
+
+/*
+ * handshake - spin reading hc until handshake completes or fails
+ * @ptr: address of hc register to be read
+ * @mask: bits to look at in result of read
+ * @done: value of those bits when handshake succeeds
+ * @usec: timeout in microseconds
+ *
+ * Returns negative errno, or zero on success
+ *
+ * Success happens when the "mask" bits have the specified value (hardware
+ * handshake done).  There are two failure modes:  "usec" have passed (major
+ * hardware flakeout), or the register reads as all-ones (hardware removed).
+ *
+ * That last failure should_only happen in cases like physical cardbus eject
+ * before driver shutdown. But it also seems to be caused by bugs in cardbus
+ * bridge shutdown:  shutting down the bridge before the devices using it.
+ */
+static int handshake(struct oxu_hcd *oxu, void __iomem *ptr,
+					u32 mask, u32 done, int usec)
+{
+	u32 result;
+
+	do {
+		result = readl(ptr);
+		if (result == ~(u32)0)		/* card removed */
+			return -ENODEV;
+		result &= mask;
+		if (result == done)
+			return 0;
+		udelay(1);
+		usec--;
+	} while (usec > 0);
+	return -ETIMEDOUT;
+}
+
+/* Force HC to halt state from unknown (EHCI spec section 2.3) */
+static int ehci_halt(struct oxu_hcd *oxu)
+{
+	u32	temp = readl(&oxu->regs->status);
+
+	/* disable any irqs left enabled by previous code */
+	writel(0, &oxu->regs->intr_enable);
+
+	if ((temp & STS_HALT) != 0)
+		return 0;
+
+	temp = readl(&oxu->regs->command);
+	temp &= ~CMD_RUN;
+	writel(temp, &oxu->regs->command);
+	return handshake(oxu, &oxu->regs->status,
+			  STS_HALT, STS_HALT, 16 * 125);
+}
+
+/* Put TDI/ARC silicon into EHCI mode */
+static void tdi_reset(struct oxu_hcd *oxu)
+{
+	u32 __iomem *reg_ptr;
+	u32 tmp;
+
+	reg_ptr = (u32 __iomem *)(((u8 __iomem *)oxu->regs) + 0x68);
+	tmp = readl(reg_ptr);
+	tmp |= 0x3;
+	writel(tmp, reg_ptr);
+}
+
+/* Reset a non-running (STS_HALT == 1) controller */
+static int ehci_reset(struct oxu_hcd *oxu)
+{
+	int	retval;
+	u32	command = readl(&oxu->regs->command);
+
+	command |= CMD_RESET;
+	dbg_cmd(oxu, "reset", command);
+	writel(command, &oxu->regs->command);
+	oxu_to_hcd(oxu)->state = HC_STATE_HALT;
+	oxu->next_statechange = jiffies;
+	retval = handshake(oxu, &oxu->regs->command,
+			    CMD_RESET, 0, 250 * 1000);
+
+	if (retval)
+		return retval;
+
+	tdi_reset(oxu);
+
+	return retval;
+}
+
+/* Idle the controller (from running) */
+static void ehci_quiesce(struct oxu_hcd *oxu)
+{
+	u32	temp;
+
+#ifdef DEBUG
+	if (!HC_IS_RUNNING(oxu_to_hcd(oxu)->state))
+		BUG();
+#endif
+
+	/* wait for any schedule enables/disables to take effect */
+	temp = readl(&oxu->regs->command) << 10;
+	temp &= STS_ASS | STS_PSS;
+	if (handshake(oxu, &oxu->regs->status, STS_ASS | STS_PSS,
+				temp, 16 * 125) != 0) {
+		oxu_to_hcd(oxu)->state = HC_STATE_HALT;
+		return;
+	}
+
+	/* then disable anything that's still active */
+	temp = readl(&oxu->regs->command);
+	temp &= ~(CMD_ASE | CMD_IAAD | CMD_PSE);
+	writel(temp, &oxu->regs->command);
+
+	/* hardware can take 16 microframes to turn off ... */
+	if (handshake(oxu, &oxu->regs->status, STS_ASS | STS_PSS,
+				0, 16 * 125) != 0) {
+		oxu_to_hcd(oxu)->state = HC_STATE_HALT;
+		return;
+	}
+}
+
+static int check_reset_complete(struct oxu_hcd *oxu, int index,
+				u32 __iomem *status_reg, int port_status)
+{
+	if (!(port_status & PORT_CONNECT)) {
+		oxu->reset_done[index] = 0;
+		return port_status;
+	}
+
+	/* if reset finished and it's still not enabled -- handoff */
+	if (!(port_status & PORT_PE)) {
+		oxu_dbg(oxu, "Failed to enable port %d on root hub TT\n",
+				index+1);
+		return port_status;
+	} else
+		oxu_dbg(oxu, "port %d high speed\n", index + 1);
+
+	return port_status;
+}
+
+static void ehci_hub_descriptor(struct oxu_hcd *oxu,
+				struct usb_hub_descriptor *desc)
+{
+	int ports = HCS_N_PORTS(oxu->hcs_params);
+	u16 temp;
+
+	desc->bDescriptorType = 0x29;
+	desc->bPwrOn2PwrGood = 10;	/* oxu 1.0, 2.3.9 says 20ms max */
+	desc->bHubContrCurrent = 0;
+
+	desc->bNbrPorts = ports;
+	temp = 1 + (ports / 8);
+	desc->bDescLength = 7 + 2 * temp;
+
+	/* two bitmaps:  ports removable, and usb 1.0 legacy PortPwrCtrlMask */
+	memset(&desc->bitmap[0], 0, temp);
+	memset(&desc->bitmap[temp], 0xff, temp);
+
+	temp = 0x0008;			/* per-port overcurrent reporting */
+	if (HCS_PPC(oxu->hcs_params))
+		temp |= 0x0001;		/* per-port power control */
+	else
+		temp |= 0x0002;		/* no power switching */
+	desc->wHubCharacteristics = (__force __u16)cpu_to_le16(temp);
+}
+
+
+/* Allocate an OXU210HP on-chip memory data buffer
+ *
+ * An on-chip memory data buffer is required for each OXU210HP USB transfer.
+ * Each transfer descriptor has one or more on-chip memory data buffers.
+ *
+ * Data buffers are allocated from a fix sized pool of data blocks.
+ * To minimise fragmentation and give reasonable memory utlisation,
+ * data buffers are allocated with sizes the power of 2 multiples of
+ * the block size, starting on an address a multiple of the allocated size.
+ *
+ * FIXME: callers of this function require a buffer to be allocated for
+ * len=0. This is a waste of on-chip memory and should be fix. Then this
+ * function should be changed to not allocate a buffer for len=0.
+ */
+static int oxu_buf_alloc(struct oxu_hcd *oxu, struct ehci_qtd *qtd, int len)
+{
+	int n_blocks;	/* minium blocks needed to hold len */
+	int a_blocks;	/* blocks allocated */
+	int i, j;
+
+	/* Don't allocte bigger than supported */
+	if (len > BUFFER_SIZE * BUFFER_NUM) {
+		oxu_err(oxu, "buffer too big (%d)\n", len);
+		return -ENOMEM;
+	}
+
+	spin_lock(&oxu->mem_lock);
+
+	/* Number of blocks needed to hold len */
+	n_blocks = (len + BUFFER_SIZE - 1) / BUFFER_SIZE;
+
+	/* Round the number of blocks up to the power of 2 */
+	for (a_blocks = 1; a_blocks < n_blocks; a_blocks <<= 1)
+		;
+
+	/* Find a suitable available data buffer */
+	for (i = 0; i < BUFFER_NUM;
+			i += max(a_blocks, (int)oxu->db_used[i])) {
+
+		/* Check all the required blocks are available */
+		for (j = 0; j < a_blocks; j++)
+			if (oxu->db_used[i + j])
+				break;
+
+		if (j != a_blocks)
+			continue;
+
+		/* Allocate blocks found! */
+		qtd->buffer = (void *) &oxu->mem->db_pool[i];
+		qtd->buffer_dma = virt_to_phys(qtd->buffer);
+
+		qtd->qtd_buffer_len = BUFFER_SIZE * a_blocks;
+		oxu->db_used[i] = a_blocks;
+
+		spin_unlock(&oxu->mem_lock);
+
+		return 0;
+	}
+
+	/* Failed */
+
+	spin_unlock(&oxu->mem_lock);
+
+	return -ENOMEM;
+}
+
+static void oxu_buf_free(struct oxu_hcd *oxu, struct ehci_qtd *qtd)
+{
+	int index;
+
+	spin_lock(&oxu->mem_lock);
+
+	index = (qtd->buffer - (void *) &oxu->mem->db_pool[0])
+							 / BUFFER_SIZE;
+	oxu->db_used[index] = 0;
+	qtd->qtd_buffer_len = 0;
+	qtd->buffer_dma = 0;
+	qtd->buffer = NULL;
+
+	spin_unlock(&oxu->mem_lock);
+
+	return;
+}
+
+static inline void ehci_qtd_init(struct ehci_qtd *qtd, dma_addr_t dma)
+{
+	memset(qtd, 0, sizeof *qtd);
+	qtd->qtd_dma = dma;
+	qtd->hw_token = cpu_to_le32(QTD_STS_HALT);
+	qtd->hw_next = EHCI_LIST_END;
+	qtd->hw_alt_next = EHCI_LIST_END;
+	INIT_LIST_HEAD(&qtd->qtd_list);
+}
+
+static inline void oxu_qtd_free(struct oxu_hcd *oxu, struct ehci_qtd *qtd)
+{
+	int index;
+
+	if (qtd->buffer)
+		oxu_buf_free(oxu, qtd);
+
+	spin_lock(&oxu->mem_lock);
+
+	index = qtd - &oxu->mem->qtd_pool[0];
+	oxu->qtd_used[index] = 0;
+
+	spin_unlock(&oxu->mem_lock);
+
+	return;
+}
+
+static struct ehci_qtd *ehci_qtd_alloc(struct oxu_hcd *oxu)
+{
+	int i;
+	struct ehci_qtd *qtd = NULL;
+
+	spin_lock(&oxu->mem_lock);
+
+	for (i = 0; i < QTD_NUM; i++)
+		if (!oxu->qtd_used[i])
+			break;
+
+	if (i < QTD_NUM) {
+		qtd = (struct ehci_qtd *) &oxu->mem->qtd_pool[i];
+		memset(qtd, 0, sizeof *qtd);
+
+		qtd->hw_token = cpu_to_le32(QTD_STS_HALT);
+		qtd->hw_next = EHCI_LIST_END;
+		qtd->hw_alt_next = EHCI_LIST_END;
+		INIT_LIST_HEAD(&qtd->qtd_list);
+
+		qtd->qtd_dma = virt_to_phys(qtd);
+
+		oxu->qtd_used[i] = 1;
+	}
+
+	spin_unlock(&oxu->mem_lock);
+
+	return qtd;
+}
+
+static void oxu_qh_free(struct oxu_hcd *oxu, struct ehci_qh *qh)
+{
+	int index;
+
+	spin_lock(&oxu->mem_lock);
+
+	index = qh - &oxu->mem->qh_pool[0];
+	oxu->qh_used[index] = 0;
+
+	spin_unlock(&oxu->mem_lock);
+
+	return;
+}
+
+static void qh_destroy(struct kref *kref)
+{
+	struct ehci_qh *qh = container_of(kref, struct ehci_qh, kref);
+	struct oxu_hcd *oxu = qh->oxu;
+
+	/* clean qtds first, and know this is not linked */
+	if (!list_empty(&qh->qtd_list) || qh->qh_next.ptr) {
+		oxu_dbg(oxu, "unused qh not empty!\n");
+		BUG();
+	}
+	if (qh->dummy)
+		oxu_qtd_free(oxu, qh->dummy);
+	oxu_qh_free(oxu, qh);
+}
+
+static struct ehci_qh *oxu_qh_alloc(struct oxu_hcd *oxu)
+{
+	int i;
+	struct ehci_qh *qh = NULL;
+
+	spin_lock(&oxu->mem_lock);
+
+	for (i = 0; i < QHEAD_NUM; i++)
+		if (!oxu->qh_used[i])
+			break;
+
+	if (i < QHEAD_NUM) {
+		qh = (struct ehci_qh *) &oxu->mem->qh_pool[i];
+		memset(qh, 0, sizeof *qh);
+
+		kref_init(&qh->kref);
+		qh->oxu = oxu;
+		qh->qh_dma = virt_to_phys(qh);
+		INIT_LIST_HEAD(&qh->qtd_list);
+
+		/* dummy td enables safe urb queuing */
+		qh->dummy = ehci_qtd_alloc(oxu);
+		if (qh->dummy == NULL) {
+			oxu_dbg(oxu, "no dummy td\n");
+			oxu->qh_used[i] = 0;
+
+			return NULL;
+		}
+
+		oxu->qh_used[i] = 1;
+	}
+
+	spin_unlock(&oxu->mem_lock);
+
+	return qh;
+}
+
+/* to share a qh (cpu threads, or hc) */
+static inline struct ehci_qh *qh_get(struct ehci_qh *qh)
+{
+	kref_get(&qh->kref);
+	return qh;
+}
+
+static inline void qh_put(struct ehci_qh *qh)
+{
+	kref_put(&qh->kref, qh_destroy);
+}
+
+static void oxu_murb_free(struct oxu_hcd *oxu, struct oxu_murb *murb)
+{
+	int index;
+
+	spin_lock(&oxu->mem_lock);
+
+	index = murb - &oxu->murb_pool[0];
+	oxu->murb_used[index] = 0;
+
+	spin_unlock(&oxu->mem_lock);
+
+	return;
+}
+
+static struct oxu_murb *oxu_murb_alloc(struct oxu_hcd *oxu)
+
+{
+	int i;
+	struct oxu_murb *murb = NULL;
+
+	spin_lock(&oxu->mem_lock);
+
+	for (i = 0; i < MURB_NUM; i++)
+		if (!oxu->murb_used[i])
+			break;
+
+	if (i < MURB_NUM) {
+		murb = &(oxu->murb_pool)[i];
+
+		oxu->murb_used[i] = 1;
+	}
+
+	spin_unlock(&oxu->mem_lock);
+
+	return murb;
+}
+
+/* The queue heads and transfer descriptors are managed from pools tied
+ * to each of the "per device" structures.
+ * This is the initialisation and cleanup code.
+ */
+static void ehci_mem_cleanup(struct oxu_hcd *oxu)
+{
+	kfree(oxu->murb_pool);
+	oxu->murb_pool = NULL;
+
+	if (oxu->async)
+		qh_put(oxu->async);
+	oxu->async = NULL;
+
+	del_timer(&oxu->urb_timer);
+
+	oxu->periodic = NULL;
+
+	/* shadow periodic table */
+	kfree(oxu->pshadow);
+	oxu->pshadow = NULL;
+}
+
+/* Remember to add cleanup code (above) if you add anything here.
+ */
+static int ehci_mem_init(struct oxu_hcd *oxu, gfp_t flags)
+{
+	int i;
+
+	for (i = 0; i < oxu->periodic_size; i++)
+		oxu->mem->frame_list[i] = EHCI_LIST_END;
+	for (i = 0; i < QHEAD_NUM; i++)
+		oxu->qh_used[i] = 0;
+	for (i = 0; i < QTD_NUM; i++)
+		oxu->qtd_used[i] = 0;
+
+	oxu->murb_pool = kcalloc(MURB_NUM, sizeof(struct oxu_murb), flags);
+	if (!oxu->murb_pool)
+		goto fail;
+
+	for (i = 0; i < MURB_NUM; i++)
+		oxu->murb_used[i] = 0;
+
+	oxu->async = oxu_qh_alloc(oxu);
+	if (!oxu->async)
+		goto fail;
+
+	oxu->periodic = (__le32 *) &oxu->mem->frame_list;
+	oxu->periodic_dma = virt_to_phys(oxu->periodic);
+
+	for (i = 0; i < oxu->periodic_size; i++)
+		oxu->periodic[i] = EHCI_LIST_END;
+
+	/* software shadow of hardware table */
+	oxu->pshadow = kcalloc(oxu->periodic_size, sizeof(void *), flags);
+	if (oxu->pshadow != NULL)
+		return 0;
+
+fail:
+	oxu_dbg(oxu, "couldn't init memory\n");
+	ehci_mem_cleanup(oxu);
+	return -ENOMEM;
+}
+
+/* Fill a qtd, returning how much of the buffer we were able to queue up.
+ */
+static int qtd_fill(struct ehci_qtd *qtd, dma_addr_t buf, size_t len,
+				int token, int maxpacket)
+{
+	int i, count;
+	u64 addr = buf;
+
+	/* one buffer entry per 4K ... first might be short or unaligned */
+	qtd->hw_buf[0] = cpu_to_le32((u32)addr);
+	qtd->hw_buf_hi[0] = cpu_to_le32((u32)(addr >> 32));
+	count = 0x1000 - (buf & 0x0fff);	/* rest of that page */
+	if (likely(len < count))		/* ... iff needed */
+		count = len;
+	else {
+		buf +=  0x1000;
+		buf &= ~0x0fff;
+
+		/* per-qtd limit: from 16K to 20K (best alignment) */
+		for (i = 1; count < len && i < 5; i++) {
+			addr = buf;
+			qtd->hw_buf[i] = cpu_to_le32((u32)addr);
+			qtd->hw_buf_hi[i] = cpu_to_le32((u32)(addr >> 32));
+			buf += 0x1000;
+			if ((count + 0x1000) < len)
+				count += 0x1000;
+			else
+				count = len;
+		}
+
+		/* short packets may only terminate transfers */
+		if (count != len)
+			count -= (count % maxpacket);
+	}
+	qtd->hw_token = cpu_to_le32((count << 16) | token);
+	qtd->length = count;
+
+	return count;
+}
+
+static inline void qh_update(struct oxu_hcd *oxu,
+				struct ehci_qh *qh, struct ehci_qtd *qtd)
+{
+	/* writes to an active overlay are unsafe */
+	BUG_ON(qh->qh_state != QH_STATE_IDLE);
+
+	qh->hw_qtd_next = QTD_NEXT(qtd->qtd_dma);
+	qh->hw_alt_next = EHCI_LIST_END;
+
+	/* Except for control endpoints, we make hardware maintain data
+	 * toggle (like OHCI) ... here (re)initialize the toggle in the QH,
+	 * and set the pseudo-toggle in udev. Only usb_clear_halt() will
+	 * ever clear it.
+	 */
+	if (!(qh->hw_info1 & cpu_to_le32(1 << 14))) {
+		unsigned	is_out, epnum;
+
+		is_out = !(qtd->hw_token & cpu_to_le32(1 << 8));
+		epnum = (le32_to_cpup(&qh->hw_info1) >> 8) & 0x0f;
+		if (unlikely(!usb_gettoggle(qh->dev, epnum, is_out))) {
+			qh->hw_token &= ~__constant_cpu_to_le32(QTD_TOGGLE);
+			usb_settoggle(qh->dev, epnum, is_out, 1);
+		}
+	}
+
+	/* HC must see latest qtd and qh data before we clear ACTIVE+HALT */
+	wmb();
+	qh->hw_token &= __constant_cpu_to_le32(QTD_TOGGLE | QTD_STS_PING);
+}
+
+/* If it weren't for a common silicon quirk (writing the dummy into the qh
+ * overlay, so qh->hw_token wrongly becomes inactive/halted), only fault
+ * recovery (including urb dequeue) would need software changes to a QH...
+ */
+static void qh_refresh(struct oxu_hcd *oxu, struct ehci_qh *qh)
+{
+	struct ehci_qtd *qtd;
+
+	if (list_empty(&qh->qtd_list))
+		qtd = qh->dummy;
+	else {
+		qtd = list_entry(qh->qtd_list.next,
+				struct ehci_qtd, qtd_list);
+		/* first qtd may already be partially processed */
+		if (cpu_to_le32(qtd->qtd_dma) == qh->hw_current)
+			qtd = NULL;
+	}
+
+	if (qtd)
+		qh_update(oxu, qh, qtd);
+}
+
+static void qtd_copy_status(struct oxu_hcd *oxu, struct urb *urb,
+				size_t length, u32 token)
+{
+	/* count IN/OUT bytes, not SETUP (even short packets) */
+	if (likely(QTD_PID(token) != 2))
+		urb->actual_length += length - QTD_LENGTH(token);
+
+	/* don't modify error codes */
+	if (unlikely(urb->status != -EINPROGRESS))
+		return;
+
+	/* force cleanup after short read; not always an error */
+	if (unlikely(IS_SHORT_READ(token)))
+		urb->status = -EREMOTEIO;
+
+	/* serious "can't proceed" faults reported by the hardware */
+	if (token & QTD_STS_HALT) {
+		if (token & QTD_STS_BABBLE) {
+			/* FIXME "must" disable babbling device's port too */
+			urb->status = -EOVERFLOW;
+		} else if (token & QTD_STS_MMF) {
+			/* fs/ls interrupt xfer missed the complete-split */
+			urb->status = -EPROTO;
+		} else if (token & QTD_STS_DBE) {
+			urb->status = (QTD_PID(token) == 1) /* IN ? */
+				? -ENOSR  /* hc couldn't read data */
+				: -ECOMM; /* hc couldn't write data */
+		} else if (token & QTD_STS_XACT) {
+			/* timeout, bad crc, wrong PID, etc; retried */
+			if (QTD_CERR(token))
+				urb->status = -EPIPE;
+			else {
+				oxu_dbg(oxu, "devpath %s ep%d%s 3strikes\n",
+					urb->dev->devpath,
+					usb_pipeendpoint(urb->pipe),
+					usb_pipein(urb->pipe) ? "in" : "out");
+				urb->status = -EPROTO;
+			}
+		/* CERR nonzero + no errors + halt --> stall */
+		} else if (QTD_CERR(token))
+			urb->status = -EPIPE;
+		else	/* unknown */
+			urb->status = -EPROTO;
+
+		oxu_vdbg(oxu, "dev%d ep%d%s qtd token %08x --> status %d\n",
+			usb_pipedevice(urb->pipe),
+			usb_pipeendpoint(urb->pipe),
+			usb_pipein(urb->pipe) ? "in" : "out",
+			token, urb->status);
+	}
+}
+
+static void ehci_urb_done(struct oxu_hcd *oxu, struct urb *urb)
+__releases(oxu->lock)
+__acquires(oxu->lock)
+{
+	if (likely(urb->hcpriv != NULL)) {
+		struct ehci_qh	*qh = (struct ehci_qh *) urb->hcpriv;
+
+		/* S-mask in a QH means it's an interrupt urb */
+		if ((qh->hw_info2 & __constant_cpu_to_le32(QH_SMASK)) != 0) {
+
+			/* ... update hc-wide periodic stats (for usbfs) */
+			oxu_to_hcd(oxu)->self.bandwidth_int_reqs--;
+		}
+		qh_put(qh);
+	}
+
+	urb->hcpriv = NULL;
+	switch (urb->status) {
+	case -EINPROGRESS:		/* success */
+		urb->status = 0;
+	default:			/* fault */
+		break;
+	case -EREMOTEIO:		/* fault or normal */
+		if (!(urb->transfer_flags & URB_SHORT_NOT_OK))
+			urb->status = 0;
+		break;
+	case -ECONNRESET:		/* canceled */
+	case -ENOENT:
+		break;
+	}
+
+#ifdef OXU_URB_TRACE
+	oxu_dbg(oxu, "%s %s urb %p ep%d%s status %d len %d/%d\n",
+		__func__, urb->dev->devpath, urb,
+		usb_pipeendpoint(urb->pipe),
+		usb_pipein(urb->pipe) ? "in" : "out",
+		urb->status,
+		urb->actual_length, urb->transfer_buffer_length);
+#endif
+
+	/* complete() can reenter this HCD */
+	spin_unlock(&oxu->lock);
+	usb_hcd_giveback_urb(oxu_to_hcd(oxu), urb, urb->status);
+	spin_lock(&oxu->lock);
+}
+
+static void start_unlink_async(struct oxu_hcd *oxu, struct ehci_qh *qh);
+static void unlink_async(struct oxu_hcd *oxu, struct ehci_qh *qh);
+
+static void intr_deschedule(struct oxu_hcd *oxu, struct ehci_qh *qh);
+static int qh_schedule(struct oxu_hcd *oxu, struct ehci_qh *qh);
+
+#define HALT_BIT __constant_cpu_to_le32(QTD_STS_HALT)
+
+/* Process and free completed qtds for a qh, returning URBs to drivers.
+ * Chases up to qh->hw_current.  Returns number of completions called,
+ * indicating how much "real" work we did.
+ */
+static unsigned qh_completions(struct oxu_hcd *oxu, struct ehci_qh *qh)
+{
+	struct ehci_qtd *last = NULL, *end = qh->dummy;
+	struct list_head *entry, *tmp;
+	int stopped;
+	unsigned count = 0;
+	int do_status = 0;
+	u8 state;
+	struct oxu_murb *murb = NULL;
+
+	if (unlikely(list_empty(&qh->qtd_list)))
+		return count;
+
+	/* completions (or tasks on other cpus) must never clobber HALT
+	 * till we've gone through and cleaned everything up, even when
+	 * they add urbs to this qh's queue or mark them for unlinking.
+	 *
+	 * NOTE:  unlinking expects to be done in queue order.
+	 */
+	state = qh->qh_state;
+	qh->qh_state = QH_STATE_COMPLETING;
+	stopped = (state == QH_STATE_IDLE);
+
+	/* remove de-activated QTDs from front of queue.
+	 * after faults (including short reads), cleanup this urb
+	 * then let the queue advance.
+	 * if queue is stopped, handles unlinks.
+	 */
+	list_for_each_safe(entry, tmp, &qh->qtd_list) {
+		struct ehci_qtd	*qtd;
+		struct urb *urb;
+		u32 token = 0;
+
+		qtd = list_entry(entry, struct ehci_qtd, qtd_list);
+		urb = qtd->urb;
+
+		/* Clean up any state from previous QTD ...*/
+		if (last) {
+			if (likely(last->urb != urb)) {
+				if (last->urb->complete == NULL) {
+					murb = (struct oxu_murb *) last->urb;
+					last->urb = murb->main;
+					if (murb->last) {
+						ehci_urb_done(oxu, last->urb);
+						count++;
+					}
+					oxu_murb_free(oxu, murb);
+				} else {
+					ehci_urb_done(oxu, last->urb);
+					count++;
+				}
+			}
+			oxu_qtd_free(oxu, last);
+			last = NULL;
+		}
+
+		/* ignore urbs submitted during completions we reported */
+		if (qtd == end)
+			break;
+
+		/* hardware copies qtd out of qh overlay */
+		rmb();
+		token = le32_to_cpu(qtd->hw_token);
+
+		/* always clean up qtds the hc de-activated */
+		if ((token & QTD_STS_ACTIVE) == 0) {
+
+			if ((token & QTD_STS_HALT) != 0) {
+				stopped = 1;
+
+			/* magic dummy for some short reads; qh won't advance.
+			 * that silicon quirk can kick in with this dummy too.
+			 */
+			} else if (IS_SHORT_READ(token) &&
+					!(qtd->hw_alt_next & EHCI_LIST_END)) {
+				stopped = 1;
+				goto halt;
+			}
+
+		/* stop scanning when we reach qtds the hc is using */
+		} else if (likely(!stopped &&
+				HC_IS_RUNNING(oxu_to_hcd(oxu)->state))) {
+			break;
+
+		} else {
+			stopped = 1;
+
+			if (unlikely(!HC_IS_RUNNING(oxu_to_hcd(oxu)->state)))
+				urb->status = -ESHUTDOWN;
+
+			/* ignore active urbs unless some previous qtd
+			 * for the urb faulted (including short read) or
+			 * its urb was canceled.  we may patch qh or qtds.
+			 */
+			if (likely(urb->status == -EINPROGRESS))
+				continue;
+
+			/* issue status after short control reads */
+			if (unlikely(do_status != 0)
+					&& QTD_PID(token) == 0 /* OUT */) {
+				do_status = 0;
+				continue;
+			}
+
+			/* token in overlay may be most current */
+			if (state == QH_STATE_IDLE
+					&& cpu_to_le32(qtd->qtd_dma)
+						== qh->hw_current)
+				token = le32_to_cpu(qh->hw_token);
+
+			/* force halt for unlinked or blocked qh, so we'll
+			 * patch the qh later and so that completions can't
+			 * activate it while we "know" it's stopped.
+			 */
+			if ((HALT_BIT & qh->hw_token) == 0) {
+halt:
+				qh->hw_token |= HALT_BIT;
+				wmb();
+			}
+		}
+
+		/* Remove it from the queue */
+		qtd_copy_status(oxu, urb->complete ?
+					urb : ((struct oxu_murb *) urb)->main,
+				qtd->length, token);
+		if ((usb_pipein(qtd->urb->pipe)) &&
+				(NULL != qtd->transfer_buffer))
+			memcpy(qtd->transfer_buffer, qtd->buffer, qtd->length);
+		do_status = (urb->status == -EREMOTEIO)
+				&& usb_pipecontrol(urb->pipe);
+
+		if (stopped && qtd->qtd_list.prev != &qh->qtd_list) {
+			last = list_entry(qtd->qtd_list.prev,
+					struct ehci_qtd, qtd_list);
+			last->hw_next = qtd->hw_next;
+		}
+		list_del(&qtd->qtd_list);
+		last = qtd;
+	}
+
+	/* last urb's completion might still need calling */
+	if (likely(last != NULL)) {
+		if (last->urb->complete == NULL) {
+			murb = (struct oxu_murb *) last->urb;
+			last->urb = murb->main;
+			if (murb->last) {
+				ehci_urb_done(oxu, last->urb);
+				count++;
+			}
+			oxu_murb_free(oxu, murb);
+		} else {
+			ehci_urb_done(oxu, last->urb);
+			count++;
+		}
+		oxu_qtd_free(oxu, last);
+	}
+
+	/* restore original state; caller must unlink or relink */
+	qh->qh_state = state;
+
+	/* be sure the hardware's done with the qh before refreshing
+	 * it after fault cleanup, or recovering from silicon wrongly
+	 * overlaying the dummy qtd (which reduces DMA chatter).
+	 */
+	if (stopped != 0 || qh->hw_qtd_next == EHCI_LIST_END) {
+		switch (state) {
+		case QH_STATE_IDLE:
+			qh_refresh(oxu, qh);
+			break;
+		case QH_STATE_LINKED:
+			/* should be rare for periodic transfers,
+			 * except maybe high bandwidth ...
+			 */
+			if ((__constant_cpu_to_le32(QH_SMASK)
+					& qh->hw_info2) != 0) {
+				intr_deschedule(oxu, qh);
+				(void) qh_schedule(oxu, qh);
+			} else
+				unlink_async(oxu, qh);
+			break;
+		/* otherwise, unlink already started */
+		}
+	}
+
+	return count;
+}
+
+/* High bandwidth multiplier, as encoded in highspeed endpoint descriptors */
+#define hb_mult(wMaxPacketSize)		(1 + (((wMaxPacketSize) >> 11) & 0x03))
+/* ... and packet size, for any kind of endpoint descriptor */
+#define max_packet(wMaxPacketSize)	((wMaxPacketSize) & 0x07ff)
+
+/* Reverse of qh_urb_transaction: free a list of TDs.
+ * used for cleanup after errors, before HC sees an URB's TDs.
+ */
+static void qtd_list_free(struct oxu_hcd *oxu,
+				struct urb *urb, struct list_head *qtd_list)
+{
+	struct list_head *entry, *temp;
+
+	list_for_each_safe(entry, temp, qtd_list) {
+		struct ehci_qtd	*qtd;
+
+		qtd = list_entry(entry, struct ehci_qtd, qtd_list);
+		list_del(&qtd->qtd_list);
+		oxu_qtd_free(oxu, qtd);
+	}
+}
+
+/* Create a list of filled qtds for this URB; won't link into qh.
+ */
+static struct list_head *qh_urb_transaction(struct oxu_hcd *oxu,
+						struct urb *urb,
+						struct list_head *head,
+						gfp_t flags)
+{
+	struct ehci_qtd	*qtd, *qtd_prev;
+	dma_addr_t buf;
+	int len, maxpacket;
+	int is_input;
+	u32 token;
+	void *transfer_buf = NULL;
+	int ret;
+
+	/*
+	 * URBs map to sequences of QTDs: one logical transaction
+	 */
+	qtd = ehci_qtd_alloc(oxu);
+	if (unlikely(!qtd))
+		return NULL;
+	list_add_tail(&qtd->qtd_list, head);
+	qtd->urb = urb;
+
+	token = QTD_STS_ACTIVE;
+	token |= (EHCI_TUNE_CERR << 10);
+	/* for split transactions, SplitXState initialized to zero */
+
+	len = urb->transfer_buffer_length;
+	is_input = usb_pipein(urb->pipe);
+	if (!urb->transfer_buffer && urb->transfer_buffer_length && is_input)
+		urb->transfer_buffer = phys_to_virt(urb->transfer_dma);
+
+	if (usb_pipecontrol(urb->pipe)) {
+		/* SETUP pid */
+		ret = oxu_buf_alloc(oxu, qtd, sizeof(struct usb_ctrlrequest));
+		if (ret)
+			goto cleanup;
+
+		qtd_fill(qtd, qtd->buffer_dma, sizeof(struct usb_ctrlrequest),
+				token | (2 /* "setup" */ << 8), 8);
+		memcpy(qtd->buffer, qtd->urb->setup_packet,
+				sizeof(struct usb_ctrlrequest));
+
+		/* ... and always at least one more pid */
+		token ^= QTD_TOGGLE;
+		qtd_prev = qtd;
+		qtd = ehci_qtd_alloc(oxu);
+		if (unlikely(!qtd))
+			goto cleanup;
+		qtd->urb = urb;
+		qtd_prev->hw_next = QTD_NEXT(qtd->qtd_dma);
+		list_add_tail(&qtd->qtd_list, head);
+
+		/* for zero length DATA stages, STATUS is always IN */
+		if (len == 0)
+			token |= (1 /* "in" */ << 8);
+	}
+
+	/*
+	 * Data transfer stage: buffer setup
+	 */
+
+	ret = oxu_buf_alloc(oxu, qtd, len);
+	if (ret)
+		goto cleanup;
+
+	buf = qtd->buffer_dma;
+	transfer_buf = urb->transfer_buffer;
+
+	if (!is_input)
+		memcpy(qtd->buffer, qtd->urb->transfer_buffer, len);
+
+	if (is_input)
+		token |= (1 /* "in" */ << 8);
+	/* else it's already initted to "out" pid (0 << 8) */
+
+	maxpacket = max_packet(usb_maxpacket(urb->dev, urb->pipe, !is_input));
+
+	/*
+	 * buffer gets wrapped in one or more qtds;
+	 * last one may be "short" (including zero len)
+	 * and may serve as a control status ack
+	 */
+	for (;;) {
+		int this_qtd_len;
+
+		this_qtd_len = qtd_fill(qtd, buf, len, token, maxpacket);
+		qtd->transfer_buffer = transfer_buf;
+		len -= this_qtd_len;
+		buf += this_qtd_len;
+		transfer_buf += this_qtd_len;
+		if (is_input)
+			qtd->hw_alt_next = oxu->async->hw_alt_next;
+
+		/* qh makes control packets use qtd toggle; maybe switch it */
+		if ((maxpacket & (this_qtd_len + (maxpacket - 1))) == 0)
+			token ^= QTD_TOGGLE;
+
+		if (likely(len <= 0))
+			break;
+
+		qtd_prev = qtd;
+		qtd = ehci_qtd_alloc(oxu);
+		if (unlikely(!qtd))
+			goto cleanup;
+		if (likely(len > 0)) {
+			ret = oxu_buf_alloc(oxu, qtd, len);
+			if (ret)
+				goto cleanup;
+		}
+		qtd->urb = urb;
+		qtd_prev->hw_next = QTD_NEXT(qtd->qtd_dma);
+		list_add_tail(&qtd->qtd_list, head);
+	}
+
+	/* unless the bulk/interrupt caller wants a chance to clean
+	 * up after short reads, hc should advance qh past this urb
+	 */
+	if (likely((urb->transfer_flags & URB_SHORT_NOT_OK) == 0
+				|| usb_pipecontrol(urb->pipe)))
+		qtd->hw_alt_next = EHCI_LIST_END;
+
+	/*
+	 * control requests may need a terminating data "status" ack;
+	 * bulk ones may need a terminating short packet (zero length).
+	 */
+	if (likely(urb->transfer_buffer_length != 0)) {
+		int	one_more = 0;
+
+		if (usb_pipecontrol(urb->pipe)) {
+			one_more = 1;
+			token ^= 0x0100;	/* "in" <--> "out"  */
+			token |= QTD_TOGGLE;	/* force DATA1 */
+		} else if (usb_pipebulk(urb->pipe)
+				&& (urb->transfer_flags & URB_ZERO_PACKET)
+				&& !(urb->transfer_buffer_length % maxpacket)) {
+			one_more = 1;
+		}
+		if (one_more) {
+			qtd_prev = qtd;
+			qtd = ehci_qtd_alloc(oxu);
+			if (unlikely(!qtd))
+				goto cleanup;
+			qtd->urb = urb;
+			qtd_prev->hw_next = QTD_NEXT(qtd->qtd_dma);
+			list_add_tail(&qtd->qtd_list, head);
+
+			/* never any data in such packets */
+			qtd_fill(qtd, 0, 0, token, 0);
+		}
+	}
+
+	/* by default, enable interrupt on urb completion */
+		qtd->hw_token |= __constant_cpu_to_le32(QTD_IOC);
+	return head;
+
+cleanup:
+	qtd_list_free(oxu, urb, head);
+	return NULL;
+}
+
+/* Each QH holds a qtd list; a QH is used for everything except iso.
+ *
+ * For interrupt urbs, the scheduler must set the microframe scheduling
+ * mask(s) each time the QH gets scheduled.  For highspeed, that's
+ * just one microframe in the s-mask.  For split interrupt transactions
+ * there are additional complications: c-mask, maybe FSTNs.
+ */
+static struct ehci_qh *qh_make(struct oxu_hcd *oxu,
+				struct urb *urb, gfp_t flags)
+{
+	struct ehci_qh *qh = oxu_qh_alloc(oxu);
+	u32 info1 = 0, info2 = 0;
+	int is_input, type;
+	int maxp = 0;
+
+	if (!qh)
+		return qh;
+
+	/*
+	 * init endpoint/device data for this QH
+	 */
+	info1 |= usb_pipeendpoint(urb->pipe) << 8;
+	info1 |= usb_pipedevice(urb->pipe) << 0;
+
+	is_input = usb_pipein(urb->pipe);
+	type = usb_pipetype(urb->pipe);
+	maxp = usb_maxpacket(urb->dev, urb->pipe, !is_input);
+
+	/* Compute interrupt scheduling parameters just once, and save.
+	 * - allowing for high bandwidth, how many nsec/uframe are used?
+	 * - split transactions need a second CSPLIT uframe; same question
+	 * - splits also need a schedule gap (for full/low speed I/O)
+	 * - qh has a polling interval
+	 *
+	 * For control/bulk requests, the HC or TT handles these.
+	 */
+	if (type == PIPE_INTERRUPT) {
+		qh->usecs = NS_TO_US(usb_calc_bus_time(USB_SPEED_HIGH,
+								is_input, 0,
+				hb_mult(maxp) * max_packet(maxp)));
+		qh->start = NO_FRAME;
+
+		if (urb->dev->speed == USB_SPEED_HIGH) {
+			qh->c_usecs = 0;
+			qh->gap_uf = 0;
+
+			qh->period = urb->interval >> 3;
+			if (qh->period == 0 && urb->interval != 1) {
+				/* NOTE interval 2 or 4 uframes could work.
+				 * But interval 1 scheduling is simpler, and
+				 * includes high bandwidth.
+				 */
+				dbg("intr period %d uframes, NYET!",
+						urb->interval);
+				goto done;
+			}
+		} else {
+			struct usb_tt	*tt = urb->dev->tt;
+			int		think_time;
+
+			/* gap is f(FS/LS transfer times) */
+			qh->gap_uf = 1 + usb_calc_bus_time(urb->dev->speed,
+					is_input, 0, maxp) / (125 * 1000);
+
+			/* FIXME this just approximates SPLIT/CSPLIT times */
+			if (is_input) {		/* SPLIT, gap, CSPLIT+DATA */
+				qh->c_usecs = qh->usecs + HS_USECS(0);
+				qh->usecs = HS_USECS(1);
+			} else {		/* SPLIT+DATA, gap, CSPLIT */
+				qh->usecs += HS_USECS(1);
+				qh->c_usecs = HS_USECS(0);
+			}
+
+			think_time = tt ? tt->think_time : 0;
+			qh->tt_usecs = NS_TO_US(think_time +
+					usb_calc_bus_time(urb->dev->speed,
+					is_input, 0, max_packet(maxp)));
+			qh->period = urb->interval;
+		}
+	}
+
+	/* support for tt scheduling, and access to toggles */
+	qh->dev = urb->dev;
+
+	/* using TT? */
+	switch (urb->dev->speed) {
+	case USB_SPEED_LOW:
+		info1 |= (1 << 12);	/* EPS "low" */
+		/* FALL THROUGH */
+
+	case USB_SPEED_FULL:
+		/* EPS 0 means "full" */
+		if (type != PIPE_INTERRUPT)
+			info1 |= (EHCI_TUNE_RL_TT << 28);
+		if (type == PIPE_CONTROL) {
+			info1 |= (1 << 27);	/* for TT */
+			info1 |= 1 << 14;	/* toggle from qtd */
+		}
+		info1 |= maxp << 16;
+
+		info2 |= (EHCI_TUNE_MULT_TT << 30);
+		info2 |= urb->dev->ttport << 23;
+
+		/* NOTE:  if (PIPE_INTERRUPT) { scheduler sets c-mask } */
+
+		break;
+
+	case USB_SPEED_HIGH:		/* no TT involved */
+		info1 |= (2 << 12);	/* EPS "high" */
+		if (type == PIPE_CONTROL) {
+			info1 |= (EHCI_TUNE_RL_HS << 28);
+			info1 |= 64 << 16;	/* usb2 fixed maxpacket */
+			info1 |= 1 << 14;	/* toggle from qtd */
+			info2 |= (EHCI_TUNE_MULT_HS << 30);
+		} else if (type == PIPE_BULK) {
+			info1 |= (EHCI_TUNE_RL_HS << 28);
+			info1 |= 512 << 16;	/* usb2 fixed maxpacket */
+			info2 |= (EHCI_TUNE_MULT_HS << 30);
+		} else {		/* PIPE_INTERRUPT */
+			info1 |= max_packet(maxp) << 16;
+			info2 |= hb_mult(maxp) << 30;
+		}
+		break;
+	default:
+		dbg("bogus dev %p speed %d", urb->dev, urb->dev->speed);
+done:
+		qh_put(qh);
+		return NULL;
+	}
+
+	/* NOTE:  if (PIPE_INTERRUPT) { scheduler sets s-mask } */
+
+	/* init as live, toggle clear, advance to dummy */
+	qh->qh_state = QH_STATE_IDLE;
+	qh->hw_info1 = cpu_to_le32(info1);
+	qh->hw_info2 = cpu_to_le32(info2);
+	usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe), !is_input, 1);
+	qh_refresh(oxu, qh);
+	return qh;
+}
+
+/* Move qh (and its qtds) onto async queue; maybe enable queue.
+ */
+static void qh_link_async(struct oxu_hcd *oxu, struct ehci_qh *qh)
+{
+	__le32 dma = QH_NEXT(qh->qh_dma);
+	struct ehci_qh *head;
+
+	/* (re)start the async schedule? */
+	head = oxu->async;
+	timer_action_done(oxu, TIMER_ASYNC_OFF);
+	if (!head->qh_next.qh) {
+		u32	cmd = readl(&oxu->regs->command);
+
+		if (!(cmd & CMD_ASE)) {
+			/* in case a clear of CMD_ASE didn't take yet */
+			(void)handshake(oxu, &oxu->regs->status,
+					STS_ASS, 0, 150);
+			cmd |= CMD_ASE | CMD_RUN;
+			writel(cmd, &oxu->regs->command);
+			oxu_to_hcd(oxu)->state = HC_STATE_RUNNING;
+			/* posted write need not be known to HC yet ... */
+		}
+	}
+
+	/* clear halt and/or toggle; and maybe recover from silicon quirk */
+	if (qh->qh_state == QH_STATE_IDLE)
+		qh_refresh(oxu, qh);
+
+	/* splice right after start */
+	qh->qh_next = head->qh_next;
+	qh->hw_next = head->hw_next;
+	wmb();
+
+	head->qh_next.qh = qh;
+	head->hw_next = dma;
+
+	qh->qh_state = QH_STATE_LINKED;
+	/* qtd completions reported later by interrupt */
+}
+
+#define	QH_ADDR_MASK	__constant_cpu_to_le32(0x7f)
+
+/*
+ * For control/bulk/interrupt, return QH with these TDs appended.
+ * Allocates and initializes the QH if necessary.
+ * Returns null if it can't allocate a QH it needs to.
+ * If the QH has TDs (urbs) already, that's great.
+ */
+static struct ehci_qh *qh_append_tds(struct oxu_hcd *oxu,
+				struct urb *urb, struct list_head *qtd_list,
+				int epnum, void	**ptr)
+{
+	struct ehci_qh *qh = NULL;
+
+	qh = (struct ehci_qh *) *ptr;
+	if (unlikely(qh == NULL)) {
+		/* can't sleep here, we have oxu->lock... */
+		qh = qh_make(oxu, urb, GFP_ATOMIC);
+		*ptr = qh;
+	}
+	if (likely(qh != NULL)) {
+		struct ehci_qtd	*qtd;
+
+		if (unlikely(list_empty(qtd_list)))
+			qtd = NULL;
+		else
+			qtd = list_entry(qtd_list->next, struct ehci_qtd,
+					qtd_list);
+
+		/* control qh may need patching ... */
+		if (unlikely(epnum == 0)) {
+
+			/* usb_reset_device() briefly reverts to address 0 */
+			if (usb_pipedevice(urb->pipe) == 0)
+				qh->hw_info1 &= ~QH_ADDR_MASK;
+		}
+
+		/* just one way to queue requests: swap with the dummy qtd.
+		 * only hc or qh_refresh() ever modify the overlay.
+		 */
+		if (likely(qtd != NULL)) {
+			struct ehci_qtd	*dummy;
+			dma_addr_t dma;
+			__le32 token;
+
+			/* to avoid racing the HC, use the dummy td instead of
+			 * the first td of our list (becomes new dummy).  both
+			 * tds stay deactivated until we're done, when the
+			 * HC is allowed to fetch the old dummy (4.10.2).
+			 */
+			token = qtd->hw_token;
+			qtd->hw_token = HALT_BIT;
+			wmb();
+			dummy = qh->dummy;
+
+			dma = dummy->qtd_dma;
+			*dummy = *qtd;
+			dummy->qtd_dma = dma;
+
+			list_del(&qtd->qtd_list);
+			list_add(&dummy->qtd_list, qtd_list);
+			list_splice(qtd_list, qh->qtd_list.prev);
+
+			ehci_qtd_init(qtd, qtd->qtd_dma);
+			qh->dummy = qtd;
+
+			/* hc must see the new dummy at list end */
+			dma = qtd->qtd_dma;
+			qtd = list_entry(qh->qtd_list.prev,
+					struct ehci_qtd, qtd_list);
+			qtd->hw_next = QTD_NEXT(dma);
+
+			/* let the hc process these next qtds */
+			dummy->hw_token = (token & ~(0x80));
+			wmb();
+			dummy->hw_token = token;
+
+			urb->hcpriv = qh_get(qh);
+		}
+	}
+	return qh;
+}
+
+static int submit_async(struct oxu_hcd	*oxu, struct urb *urb,
+			struct list_head *qtd_list, gfp_t mem_flags)
+{
+	struct ehci_qtd	*qtd;
+	int epnum;
+	unsigned long flags;
+	struct ehci_qh *qh = NULL;
+	int rc = 0;
+
+	qtd = list_entry(qtd_list->next, struct ehci_qtd, qtd_list);
+	epnum = urb->ep->desc.bEndpointAddress;
+
+#ifdef OXU_URB_TRACE
+	oxu_dbg(oxu, "%s %s urb %p ep%d%s len %d, qtd %p [qh %p]\n",
+		__func__, urb->dev->devpath, urb,
+		epnum & 0x0f, (epnum & USB_DIR_IN) ? "in" : "out",
+		urb->transfer_buffer_length,
+		qtd, urb->ep->hcpriv);
+#endif
+
+	spin_lock_irqsave(&oxu->lock, flags);
+	if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE,
+			       &oxu_to_hcd(oxu)->flags))) {
+		rc = -ESHUTDOWN;
+		goto done;
+	}
+
+	qh = qh_append_tds(oxu, urb, qtd_list, epnum, &urb->ep->hcpriv);
+	if (unlikely(qh == NULL)) {
+		rc = -ENOMEM;
+		goto done;
+	}
+
+	/* Control/bulk operations through TTs don't need scheduling,
+	 * the HC and TT handle it when the TT has a buffer ready.
+	 */
+	if (likely(qh->qh_state == QH_STATE_IDLE))
+		qh_link_async(oxu, qh_get(qh));
+done:
+	spin_unlock_irqrestore(&oxu->lock, flags);
+	if (unlikely(qh == NULL))
+		qtd_list_free(oxu, urb, qtd_list);
+	return rc;
+}
+
+/* The async qh for the qtds being reclaimed are now unlinked from the HC */
+
+static void end_unlink_async(struct oxu_hcd *oxu)
+{
+	struct ehci_qh *qh = oxu->reclaim;
+	struct ehci_qh *next;
+
+	timer_action_done(oxu, TIMER_IAA_WATCHDOG);
+
+	qh->qh_state = QH_STATE_IDLE;
+	qh->qh_next.qh = NULL;
+	qh_put(qh);			/* refcount from reclaim */
+
+	/* other unlink(s) may be pending (in QH_STATE_UNLINK_WAIT) */
+	next = qh->reclaim;
+	oxu->reclaim = next;
+	oxu->reclaim_ready = 0;
+	qh->reclaim = NULL;
+
+	qh_completions(oxu, qh);
+
+	if (!list_empty(&qh->qtd_list)
+			&& HC_IS_RUNNING(oxu_to_hcd(oxu)->state))
+		qh_link_async(oxu, qh);
+	else {
+		qh_put(qh);		/* refcount from async list */
+
+		/* it's not free to turn the async schedule on/off; leave it
+		 * active but idle for a while once it empties.
+		 */
+		if (HC_IS_RUNNING(oxu_to_hcd(oxu)->state)
+				&& oxu->async->qh_next.qh == NULL)
+			timer_action(oxu, TIMER_ASYNC_OFF);
+	}
+
+	if (next) {
+		oxu->reclaim = NULL;
+		start_unlink_async(oxu, next);
+	}
+}
+
+/* makes sure the async qh will become idle */
+/* caller must own oxu->lock */
+
+static void start_unlink_async(struct oxu_hcd *oxu, struct ehci_qh *qh)
+{
+	int cmd = readl(&oxu->regs->command);
+	struct ehci_qh *prev;
+
+#ifdef DEBUG
+	assert_spin_locked(&oxu->lock);
+	if (oxu->reclaim || (qh->qh_state != QH_STATE_LINKED
+				&& qh->qh_state != QH_STATE_UNLINK_WAIT))
+		BUG();
+#endif
+
+	/* stop async schedule right now? */
+	if (unlikely(qh == oxu->async)) {
+		/* can't get here without STS_ASS set */
+		if (oxu_to_hcd(oxu)->state != HC_STATE_HALT
+				&& !oxu->reclaim) {
+			/* ... and CMD_IAAD clear */
+			writel(cmd & ~CMD_ASE, &oxu->regs->command);
+			wmb();
+			/* handshake later, if we need to */
+			timer_action_done(oxu, TIMER_ASYNC_OFF);
+		}
+		return;
+	}
+
+	qh->qh_state = QH_STATE_UNLINK;
+	oxu->reclaim = qh = qh_get(qh);
+
+	prev = oxu->async;
+	while (prev->qh_next.qh != qh)
+		prev = prev->qh_next.qh;
+
+	prev->hw_next = qh->hw_next;
+	prev->qh_next = qh->qh_next;
+	wmb();
+
+	if (unlikely(oxu_to_hcd(oxu)->state == HC_STATE_HALT)) {
+		/* if (unlikely(qh->reclaim != 0))
+		 *	this will recurse, probably not much
+		 */
+		end_unlink_async(oxu);
+		return;
+	}
+
+	oxu->reclaim_ready = 0;
+	cmd |= CMD_IAAD;
+	writel(cmd, &oxu->regs->command);
+	(void) readl(&oxu->regs->command);
+	timer_action(oxu, TIMER_IAA_WATCHDOG);
+}
+
+static void scan_async(struct oxu_hcd *oxu)
+{
+	struct ehci_qh *qh;
+	enum ehci_timer_action action = TIMER_IO_WATCHDOG;
+
+	if (!++(oxu->stamp))
+		oxu->stamp++;
+	timer_action_done(oxu, TIMER_ASYNC_SHRINK);
+rescan:
+	qh = oxu->async->qh_next.qh;
+	if (likely(qh != NULL)) {
+		do {
+			/* clean any finished work for this qh */
+			if (!list_empty(&qh->qtd_list)
+					&& qh->stamp != oxu->stamp) {
+				int temp;
+
+				/* unlinks could happen here; completion
+				 * reporting drops the lock.  rescan using
+				 * the latest schedule, but don't rescan
+				 * qhs we already finished (no looping).
+				 */
+				qh = qh_get(qh);
+				qh->stamp = oxu->stamp;
+				temp = qh_completions(oxu, qh);
+				qh_put(qh);
+				if (temp != 0)
+					goto rescan;
+			}
+
+			/* unlink idle entries, reducing HC PCI usage as well
+			 * as HCD schedule-scanning costs.  delay for any qh
+			 * we just scanned, there's a not-unusual case that it
+			 * doesn't stay idle for long.
+			 * (plus, avoids some kind of re-activation race.)
+			 */
+			if (list_empty(&qh->qtd_list)) {
+				if (qh->stamp == oxu->stamp)
+					action = TIMER_ASYNC_SHRINK;
+				else if (!oxu->reclaim
+					    && qh->qh_state == QH_STATE_LINKED)
+					start_unlink_async(oxu, qh);
+			}
+
+			qh = qh->qh_next.qh;
+		} while (qh);
+	}
+	if (action == TIMER_ASYNC_SHRINK)
+		timer_action(oxu, TIMER_ASYNC_SHRINK);
+}
+
+/*
+ * periodic_next_shadow - return "next" pointer on shadow list
+ * @periodic: host pointer to qh/itd/sitd
+ * @tag: hardware tag for type of this record
+ */
+static union ehci_shadow *periodic_next_shadow(union ehci_shadow *periodic,
+						__le32 tag)
+{
+	switch (tag) {
+	default:
+	case Q_TYPE_QH:
+		return &periodic->qh->qh_next;
+	}
+}
+
+/* caller must hold oxu->lock */
+static void periodic_unlink(struct oxu_hcd *oxu, unsigned frame, void *ptr)
+{
+	union ehci_shadow *prev_p = &oxu->pshadow[frame];
+	__le32 *hw_p = &oxu->periodic[frame];
+	union ehci_shadow here = *prev_p;
+
+	/* find predecessor of "ptr"; hw and shadow lists are in sync */
+	while (here.ptr && here.ptr != ptr) {
+		prev_p = periodic_next_shadow(prev_p, Q_NEXT_TYPE(*hw_p));
+		hw_p = here.hw_next;
+		here = *prev_p;
+	}
+	/* an interrupt entry (at list end) could have been shared */
+	if (!here.ptr)
+		return;
+
+	/* update shadow and hardware lists ... the old "next" pointers
+	 * from ptr may still be in use, the caller updates them.
+	 */
+	*prev_p = *periodic_next_shadow(&here, Q_NEXT_TYPE(*hw_p));
+	*hw_p = *here.hw_next;
+}
+
+/* how many of the uframe's 125 usecs are allocated? */
+static unsigned short periodic_usecs(struct oxu_hcd *oxu,
+					unsigned frame, unsigned uframe)
+{
+	__le32 *hw_p = &oxu->periodic[frame];
+	union ehci_shadow *q = &oxu->pshadow[frame];
+	unsigned usecs = 0;
+
+	while (q->ptr) {
+		switch (Q_NEXT_TYPE(*hw_p)) {
+		case Q_TYPE_QH:
+		default:
+			/* is it in the S-mask? */
+			if (q->qh->hw_info2 & cpu_to_le32(1 << uframe))
+				usecs += q->qh->usecs;
+			/* ... or C-mask? */
+			if (q->qh->hw_info2 & cpu_to_le32(1 << (8 + uframe)))
+				usecs += q->qh->c_usecs;
+			hw_p = &q->qh->hw_next;
+			q = &q->qh->qh_next;
+			break;
+		}
+	}
+#ifdef DEBUG
+	if (usecs > 100)
+		oxu_err(oxu, "uframe %d sched overrun: %d usecs\n",
+						frame * 8 + uframe, usecs);
+#endif
+	return usecs;
+}
+
+static int enable_periodic(struct oxu_hcd *oxu)
+{
+	u32 cmd;
+	int status;
+
+	/* did clearing PSE did take effect yet?
+	 * takes effect only at frame boundaries...
+	 */
+	status = handshake(oxu, &oxu->regs->status, STS_PSS, 0, 9 * 125);
+	if (status != 0) {
+		oxu_to_hcd(oxu)->state = HC_STATE_HALT;
+		return status;
+	}
+
+	cmd = readl(&oxu->regs->command) | CMD_PSE;
+	writel(cmd, &oxu->regs->command);
+	/* posted write ... PSS happens later */
+	oxu_to_hcd(oxu)->state = HC_STATE_RUNNING;
+
+	/* make sure ehci_work scans these */
+	oxu->next_uframe = readl(&oxu->regs->frame_index)
+		% (oxu->periodic_size << 3);
+	return 0;
+}
+
+static int disable_periodic(struct oxu_hcd *oxu)
+{
+	u32 cmd;
+	int status;
+
+	/* did setting PSE not take effect yet?
+	 * takes effect only at frame boundaries...
+	 */
+	status = handshake(oxu, &oxu->regs->status, STS_PSS, STS_PSS, 9 * 125);
+	if (status != 0) {
+		oxu_to_hcd(oxu)->state = HC_STATE_HALT;
+		return status;
+	}
+
+	cmd = readl(&oxu->regs->command) & ~CMD_PSE;
+	writel(cmd, &oxu->regs->command);
+	/* posted write ... */
+
+	oxu->next_uframe = -1;
+	return 0;
+}
+
+/* periodic schedule slots have iso tds (normal or split) first, then a
+ * sparse tree for active interrupt transfers.
+ *
+ * this just links in a qh; caller guarantees uframe masks are set right.
+ * no FSTN support (yet; oxu 0.96+)
+ */
+static int qh_link_periodic(struct oxu_hcd *oxu, struct ehci_qh *qh)
+{
+	unsigned i;
+	unsigned period = qh->period;
+
+	dev_dbg(&qh->dev->dev,
+		"link qh%d-%04x/%p start %d [%d/%d us]\n",
+		period, le32_to_cpup(&qh->hw_info2) & (QH_CMASK | QH_SMASK),
+		qh, qh->start, qh->usecs, qh->c_usecs);
+
+	/* high bandwidth, or otherwise every microframe */
+	if (period == 0)
+		period = 1;
+
+	for (i = qh->start; i < oxu->periodic_size; i += period) {
+		union ehci_shadow	*prev = &oxu->pshadow[i];
+		__le32			*hw_p = &oxu->periodic[i];
+		union ehci_shadow	here = *prev;
+		__le32			type = 0;
+
+		/* skip the iso nodes at list head */
+		while (here.ptr) {
+			type = Q_NEXT_TYPE(*hw_p);
+			if (type == Q_TYPE_QH)
+				break;
+			prev = periodic_next_shadow(prev, type);
+			hw_p = &here.qh->hw_next;
+			here = *prev;
+		}
+
+		/* sorting each branch by period (slow-->fast)
+		 * enables sharing interior tree nodes
+		 */
+		while (here.ptr && qh != here.qh) {
+			if (qh->period > here.qh->period)
+				break;
+			prev = &here.qh->qh_next;
+			hw_p = &here.qh->hw_next;
+			here = *prev;
+		}
+		/* link in this qh, unless some earlier pass did that */
+		if (qh != here.qh) {
+			qh->qh_next = here;
+			if (here.qh)
+				qh->hw_next = *hw_p;
+			wmb();
+			prev->qh = qh;
+			*hw_p = QH_NEXT(qh->qh_dma);
+		}
+	}
+	qh->qh_state = QH_STATE_LINKED;
+	qh_get(qh);
+
+	/* update per-qh bandwidth for usbfs */
+	oxu_to_hcd(oxu)->self.bandwidth_allocated += qh->period
+		? ((qh->usecs + qh->c_usecs) / qh->period)
+		: (qh->usecs * 8);
+
+	/* maybe enable periodic schedule processing */
+	if (!oxu->periodic_sched++)
+		return enable_periodic(oxu);
+
+	return 0;
+}
+
+static void qh_unlink_periodic(struct oxu_hcd *oxu, struct ehci_qh *qh)
+{
+	unsigned i;
+	unsigned period;
+
+	/* FIXME:
+	 *   IF this isn't high speed
+	 *   and this qh is active in the current uframe
+	 *   (and overlay token SplitXstate is false?)
+	 * THEN
+	 *   qh->hw_info1 |= __constant_cpu_to_le32(1 << 7 "ignore");
+	 */
+
+	/* high bandwidth, or otherwise part of every microframe */
+	period = qh->period;
+	if (period == 0)
+		period = 1;
+
+	for (i = qh->start; i < oxu->periodic_size; i += period)
+		periodic_unlink(oxu, i, qh);
+
+	/* update per-qh bandwidth for usbfs */
+	oxu_to_hcd(oxu)->self.bandwidth_allocated -= qh->period
+		? ((qh->usecs + qh->c_usecs) / qh->period)
+		: (qh->usecs * 8);
+
+	dev_dbg(&qh->dev->dev,
+		"unlink qh%d-%04x/%p start %d [%d/%d us]\n",
+		qh->period,
+		le32_to_cpup(&qh->hw_info2) & (QH_CMASK | QH_SMASK),
+		qh, qh->start, qh->usecs, qh->c_usecs);
+
+	/* qh->qh_next still "live" to HC */
+	qh->qh_state = QH_STATE_UNLINK;
+	qh->qh_next.ptr = NULL;
+	qh_put(qh);
+
+	/* maybe turn off periodic schedule */
+	oxu->periodic_sched--;
+	if (!oxu->periodic_sched)
+		(void) disable_periodic(oxu);
+}
+
+static void intr_deschedule(struct oxu_hcd *oxu, struct ehci_qh *qh)
+{
+	unsigned wait;
+
+	qh_unlink_periodic(oxu, qh);
+
+	/* simple/paranoid:  always delay, expecting the HC needs to read
+	 * qh->hw_next or finish a writeback after SPLIT/CSPLIT ... and
+	 * expect khubd to clean up after any CSPLITs we won't issue.
+	 * active high speed queues may need bigger delays...
+	 */
+	if (list_empty(&qh->qtd_list)
+		|| (__constant_cpu_to_le32(QH_CMASK) & qh->hw_info2) != 0)
+		wait = 2;
+	else
+		wait = 55;	/* worst case: 3 * 1024 */
+
+	udelay(wait);
+	qh->qh_state = QH_STATE_IDLE;
+	qh->hw_next = EHCI_LIST_END;
+	wmb();
+}
+
+static int check_period(struct oxu_hcd *oxu,
+			unsigned frame, unsigned uframe,
+			unsigned period, unsigned usecs)
+{
+	int claimed;
+
+	/* complete split running into next frame?
+	 * given FSTN support, we could sometimes check...
+	 */
+	if (uframe >= 8)
+		return 0;
+
+	/*
+	 * 80% periodic == 100 usec/uframe available
+	 * convert "usecs we need" to "max already claimed"
+	 */
+	usecs = 100 - usecs;
+
+	/* we "know" 2 and 4 uframe intervals were rejected; so
+	 * for period 0, check _every_ microframe in the schedule.
+	 */
+	if (unlikely(period == 0)) {
+		do {
+			for (uframe = 0; uframe < 7; uframe++) {
+				claimed = periodic_usecs(oxu, frame, uframe);
+				if (claimed > usecs)
+					return 0;
+			}
+		} while ((frame += 1) < oxu->periodic_size);
+
+	/* just check the specified uframe, at that period */
+	} else {
+		do {
+			claimed = periodic_usecs(oxu, frame, uframe);
+			if (claimed > usecs)
+				return 0;
+		} while ((frame += period) < oxu->periodic_size);
+	}
+
+	return 1;
+}
+
+static int check_intr_schedule(struct oxu_hcd	*oxu,
+				unsigned frame, unsigned uframe,
+				const struct ehci_qh *qh, __le32 *c_maskp)
+{
+	int retval = -ENOSPC;
+
+	if (qh->c_usecs && uframe >= 6)		/* FSTN territory? */
+		goto done;
+
+	if (!check_period(oxu, frame, uframe, qh->period, qh->usecs))
+		goto done;
+	if (!qh->c_usecs) {
+		retval = 0;
+		*c_maskp = 0;
+		goto done;
+	}
+
+done:
+	return retval;
+}
+
+/* "first fit" scheduling policy used the first time through,
+ * or when the previous schedule slot can't be re-used.
+ */
+static int qh_schedule(struct oxu_hcd *oxu, struct ehci_qh *qh)
+{
+	int		status;
+	unsigned	uframe;
+	__le32		c_mask;
+	unsigned	frame;		/* 0..(qh->period - 1), or NO_FRAME */
+
+	qh_refresh(oxu, qh);
+	qh->hw_next = EHCI_LIST_END;
+	frame = qh->start;
+
+	/* reuse the previous schedule slots, if we can */
+	if (frame < qh->period) {
+		uframe = ffs(le32_to_cpup(&qh->hw_info2) & QH_SMASK);
+		status = check_intr_schedule(oxu, frame, --uframe,
+				qh, &c_mask);
+	} else {
+		uframe = 0;
+		c_mask = 0;
+		status = -ENOSPC;
+	}
+
+	/* else scan the schedule to find a group of slots such that all
+	 * uframes have enough periodic bandwidth available.
+	 */
+	if (status) {
+		/* "normal" case, uframing flexible except with splits */
+		if (qh->period) {
+			frame = qh->period - 1;
+			do {
+				for (uframe = 0; uframe < 8; uframe++) {
+					status = check_intr_schedule(oxu,
+							frame, uframe, qh,
+							&c_mask);
+					if (status == 0)
+						break;
+				}
+			} while (status && frame--);
+
+		/* qh->period == 0 means every uframe */
+		} else {
+			frame = 0;
+			status = check_intr_schedule(oxu, 0, 0, qh, &c_mask);
+		}
+		if (status)
+			goto done;
+		qh->start = frame;
+
+		/* reset S-frame and (maybe) C-frame masks */
+		qh->hw_info2 &= __constant_cpu_to_le32(~(QH_CMASK | QH_SMASK));
+		qh->hw_info2 |= qh->period
+			? cpu_to_le32(1 << uframe)
+			: __constant_cpu_to_le32(QH_SMASK);
+		qh->hw_info2 |= c_mask;
+	} else
+		oxu_dbg(oxu, "reused qh %p schedule\n", qh);
+
+	/* stuff into the periodic schedule */
+	status = qh_link_periodic(oxu, qh);
+done:
+	return status;
+}
+
+static int intr_submit(struct oxu_hcd *oxu, struct urb *urb,
+			struct list_head *qtd_list, gfp_t mem_flags)
+{
+	unsigned epnum;
+	unsigned long flags;
+	struct ehci_qh *qh;
+	int status = 0;
+	struct list_head	empty;
+
+	/* get endpoint and transfer/schedule data */
+	epnum = urb->ep->desc.bEndpointAddress;
+
+	spin_lock_irqsave(&oxu->lock, flags);
+
+	if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE,
+			       &oxu_to_hcd(oxu)->flags))) {
+		status = -ESHUTDOWN;
+		goto done;
+	}
+
+	/* get qh and force any scheduling errors */
+	INIT_LIST_HEAD(&empty);
+	qh = qh_append_tds(oxu, urb, &empty, epnum, &urb->ep->hcpriv);
+	if (qh == NULL) {
+		status = -ENOMEM;
+		goto done;
+	}
+	if (qh->qh_state == QH_STATE_IDLE) {
+		status = qh_schedule(oxu, qh);
+		if (status != 0)
+			goto done;
+	}
+
+	/* then queue the urb's tds to the qh */
+	qh = qh_append_tds(oxu, urb, qtd_list, epnum, &urb->ep->hcpriv);
+	BUG_ON(qh == NULL);
+
+	/* ... update usbfs periodic stats */
+	oxu_to_hcd(oxu)->self.bandwidth_int_reqs++;
+
+done:
+	spin_unlock_irqrestore(&oxu->lock, flags);
+	if (status)
+		qtd_list_free(oxu, urb, qtd_list);
+
+	return status;
+}
+
+static inline int itd_submit(struct oxu_hcd *oxu, struct urb *urb,
+						gfp_t mem_flags)
+{
+	oxu_dbg(oxu, "iso support is missing!\n");
+	return -ENOSYS;
+}
+
+static inline int sitd_submit(struct oxu_hcd *oxu, struct urb *urb,
+						gfp_t mem_flags)
+{
+	oxu_dbg(oxu, "split iso support is missing!\n");
+	return -ENOSYS;
+}
+
+static void scan_periodic(struct oxu_hcd *oxu)
+{
+	unsigned frame, clock, now_uframe, mod;
+	unsigned modified;
+
+	mod = oxu->periodic_size << 3;
+
+	/*
+	 * When running, scan from last scan point up to "now"
+	 * else clean up by scanning everything that's left.
+	 * Touches as few pages as possible:  cache-friendly.
+	 */
+	now_uframe = oxu->next_uframe;
+	if (HC_IS_RUNNING(oxu_to_hcd(oxu)->state))
+		clock = readl(&oxu->regs->frame_index);
+	else
+		clock = now_uframe + mod - 1;
+	clock %= mod;
+
+	for (;;) {
+		union ehci_shadow	q, *q_p;
+		__le32			type, *hw_p;
+		unsigned		uframes;
+
+		/* don't scan past the live uframe */
+		frame = now_uframe >> 3;
+		if (frame == (clock >> 3))
+			uframes = now_uframe & 0x07;
+		else {
+			/* safe to scan the whole frame at once */
+			now_uframe |= 0x07;
+			uframes = 8;
+		}
+
+restart:
+		/* scan each element in frame's queue for completions */
+		q_p = &oxu->pshadow[frame];
+		hw_p = &oxu->periodic[frame];
+		q.ptr = q_p->ptr;
+		type = Q_NEXT_TYPE(*hw_p);
+		modified = 0;
+
+		while (q.ptr != NULL) {
+			union ehci_shadow temp;
+			int live;
+
+			live = HC_IS_RUNNING(oxu_to_hcd(oxu)->state);
+			switch (type) {
+			case Q_TYPE_QH:
+				/* handle any completions */
+				temp.qh = qh_get(q.qh);
+				type = Q_NEXT_TYPE(q.qh->hw_next);
+				q = q.qh->qh_next;
+				modified = qh_completions(oxu, temp.qh);
+				if (unlikely(list_empty(&temp.qh->qtd_list)))
+					intr_deschedule(oxu, temp.qh);
+				qh_put(temp.qh);
+				break;
+			default:
+				dbg("corrupt type %d frame %d shadow %p",
+					type, frame, q.ptr);
+				q.ptr = NULL;
+			}
+
+			/* assume completion callbacks modify the queue */
+			if (unlikely(modified))
+				goto restart;
+		}
+
+		/* Stop when we catch up to the HC */
+
+		/* FIXME:  this assumes we won't get lapped when
+		 * latencies climb; that should be rare, but...
+		 * detect it, and just go all the way around.
+		 * FLR might help detect this case, so long as latencies
+		 * don't exceed periodic_size msec (default 1.024 sec).
+		 */
+
+		/* FIXME: likewise assumes HC doesn't halt mid-scan */
+
+		if (now_uframe == clock) {
+			unsigned	now;
+
+			if (!HC_IS_RUNNING(oxu_to_hcd(oxu)->state))
+				break;
+			oxu->next_uframe = now_uframe;
+			now = readl(&oxu->regs->frame_index) % mod;
+			if (now_uframe == now)
+				break;
+
+			/* rescan the rest of this frame, then ... */
+			clock = now;
+		} else {
+			now_uframe++;
+			now_uframe %= mod;
+		}
+	}
+}
+
+/* On some systems, leaving remote wakeup enabled prevents system shutdown.
+ * The firmware seems to think that powering off is a wakeup event!
+ * This routine turns off remote wakeup and everything else, on all ports.
+ */
+static void ehci_turn_off_all_ports(struct oxu_hcd *oxu)
+{
+	int port = HCS_N_PORTS(oxu->hcs_params);
+
+	while (port--)
+		writel(PORT_RWC_BITS, &oxu->regs->port_status[port]);
+}
+
+static void ehci_port_power(struct oxu_hcd *oxu, int is_on)
+{
+	unsigned port;
+
+	if (!HCS_PPC(oxu->hcs_params))
+		return;
+
+	oxu_dbg(oxu, "...power%s ports...\n", is_on ? "up" : "down");
+	for (port = HCS_N_PORTS(oxu->hcs_params); port > 0; )
+		(void) oxu_hub_control(oxu_to_hcd(oxu),
+				is_on ? SetPortFeature : ClearPortFeature,
+				USB_PORT_FEAT_POWER,
+				port--, NULL, 0);
+	msleep(20);
+}
+
+/* Called from some interrupts, timers, and so on.
+ * It calls driver completion functions, after dropping oxu->lock.
+ */
+static void ehci_work(struct oxu_hcd *oxu)
+{
+	timer_action_done(oxu, TIMER_IO_WATCHDOG);
+	if (oxu->reclaim_ready)
+		end_unlink_async(oxu);
+
+	/* another CPU may drop oxu->lock during a schedule scan while
+	 * it reports urb completions.  this flag guards against bogus
+	 * attempts at re-entrant schedule scanning.
+	 */
+	if (oxu->scanning)
+		return;
+	oxu->scanning = 1;
+	scan_async(oxu);
+	if (oxu->next_uframe != -1)
+		scan_periodic(oxu);
+	oxu->scanning = 0;
+
+	/* the IO watchdog guards against hardware or driver bugs that
+	 * misplace IRQs, and should let us run completely without IRQs.
+	 * such lossage has been observed on both VT6202 and VT8235.
+	 */
+	if (HC_IS_RUNNING(oxu_to_hcd(oxu)->state) &&
+			(oxu->async->qh_next.ptr != NULL ||
+			 oxu->periodic_sched != 0))
+		timer_action(oxu, TIMER_IO_WATCHDOG);
+}
+
+static void unlink_async(struct oxu_hcd *oxu, struct ehci_qh *qh)
+{
+	/* if we need to use IAA and it's busy, defer */
+	if (qh->qh_state == QH_STATE_LINKED
+			&& oxu->reclaim
+			&& HC_IS_RUNNING(oxu_to_hcd(oxu)->state)) {
+		struct ehci_qh		*last;
+
+		for (last = oxu->reclaim;
+				last->reclaim;
+				last = last->reclaim)
+			continue;
+		qh->qh_state = QH_STATE_UNLINK_WAIT;
+		last->reclaim = qh;
+
+	/* bypass IAA if the hc can't care */
+	} else if (!HC_IS_RUNNING(oxu_to_hcd(oxu)->state) && oxu->reclaim)
+		end_unlink_async(oxu);
+
+	/* something else might have unlinked the qh by now */
+	if (qh->qh_state == QH_STATE_LINKED)
+		start_unlink_async(oxu, qh);
+}
+
+/*
+ * USB host controller methods
+ */
+
+static irqreturn_t oxu210_hcd_irq(struct usb_hcd *hcd)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+	u32 status, pcd_status = 0;
+	int bh;
+
+	spin_lock(&oxu->lock);
+
+	status = readl(&oxu->regs->status);
+
+	/* e.g. cardbus physical eject */
+	if (status == ~(u32) 0) {
+		oxu_dbg(oxu, "device removed\n");
+		goto dead;
+	}
+
+	status &= INTR_MASK;
+	if (!status) {			/* irq sharing? */
+		spin_unlock(&oxu->lock);
+		return IRQ_NONE;
+	}
+
+	/* clear (just) interrupts */
+	writel(status, &oxu->regs->status);
+	readl(&oxu->regs->command);	/* unblock posted write */
+	bh = 0;
+
+#ifdef OXU_VERBOSE_DEBUG
+	/* unrequested/ignored: Frame List Rollover */
+	dbg_status(oxu, "irq", status);
+#endif
+
+	/* INT, ERR, and IAA interrupt rates can be throttled */
+
+	/* normal [4.15.1.2] or error [4.15.1.1] completion */
+	if (likely((status & (STS_INT|STS_ERR)) != 0))
+		bh = 1;
+
+	/* complete the unlinking of some qh [4.15.2.3] */
+	if (status & STS_IAA) {
+		oxu->reclaim_ready = 1;
+		bh = 1;
+	}
+
+	/* remote wakeup [4.3.1] */
+	if (status & STS_PCD) {
+		unsigned i = HCS_N_PORTS(oxu->hcs_params);
+		pcd_status = status;
+
+		/* resume root hub? */
+		if (!(readl(&oxu->regs->command) & CMD_RUN))
+			usb_hcd_resume_root_hub(hcd);
+
+		while (i--) {
+			int pstatus = readl(&oxu->regs->port_status[i]);
+
+			if (pstatus & PORT_OWNER)
+				continue;
+			if (!(pstatus & PORT_RESUME)
+					|| oxu->reset_done[i] != 0)
+				continue;
+
+			/* start 20 msec resume signaling from this port,
+			 * and make khubd collect PORT_STAT_C_SUSPEND to
+			 * stop that signaling.
+			 */
+			oxu->reset_done[i] = jiffies + msecs_to_jiffies(20);
+			oxu_dbg(oxu, "port %d remote wakeup\n", i + 1);
+			mod_timer(&hcd->rh_timer, oxu->reset_done[i]);
+		}
+	}
+
+	/* PCI errors [4.15.2.4] */
+	if (unlikely((status & STS_FATAL) != 0)) {
+		/* bogus "fatal" IRQs appear on some chips... why?  */
+		status = readl(&oxu->regs->status);
+		dbg_cmd(oxu, "fatal", readl(&oxu->regs->command));
+		dbg_status(oxu, "fatal", status);
+		if (status & STS_HALT) {
+			oxu_err(oxu, "fatal error\n");
+dead:
+			ehci_reset(oxu);
+			writel(0, &oxu->regs->configured_flag);
+			/* generic layer kills/unlinks all urbs, then
+			 * uses oxu_stop to clean up the rest
+			 */
+			bh = 1;
+		}
+	}
+
+	if (bh)
+		ehci_work(oxu);
+	spin_unlock(&oxu->lock);
+	if (pcd_status & STS_PCD)
+		usb_hcd_poll_rh_status(hcd);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t oxu_irq(struct usb_hcd *hcd)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+	int ret = IRQ_HANDLED;
+
+	u32 status = oxu_readl(hcd->regs, OXU_CHIPIRQSTATUS);
+	u32 enable = oxu_readl(hcd->regs, OXU_CHIPIRQEN_SET);
+
+	/* Disable all interrupt */
+	oxu_writel(hcd->regs, OXU_CHIPIRQEN_CLR, enable);
+
+	if ((oxu->is_otg && (status & OXU_USBOTGI)) ||
+		(!oxu->is_otg && (status & OXU_USBSPHI)))
+		oxu210_hcd_irq(hcd);
+	else
+		ret = IRQ_NONE;
+
+	/* Enable all interrupt back */
+	oxu_writel(hcd->regs, OXU_CHIPIRQEN_SET, enable);
+
+	return ret;
+}
+
+static void oxu_watchdog(unsigned long param)
+{
+	struct oxu_hcd	*oxu = (struct oxu_hcd *) param;
+	unsigned long flags;
+
+	spin_lock_irqsave(&oxu->lock, flags);
+
+	/* lost IAA irqs wedge things badly; seen with a vt8235 */
+	if (oxu->reclaim) {
+		u32 status = readl(&oxu->regs->status);
+		if (status & STS_IAA) {
+			oxu_vdbg(oxu, "lost IAA\n");
+			writel(STS_IAA, &oxu->regs->status);
+			oxu->reclaim_ready = 1;
+		}
+	}
+
+	/* stop async processing after it's idled a bit */
+	if (test_bit(TIMER_ASYNC_OFF, &oxu->actions))
+		start_unlink_async(oxu, oxu->async);
+
+	/* oxu could run by timer, without IRQs ... */
+	ehci_work(oxu);
+
+	spin_unlock_irqrestore(&oxu->lock, flags);
+}
+
+/* One-time init, only for memory state.
+ */
+static int oxu_hcd_init(struct usb_hcd *hcd)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+	u32 temp;
+	int retval;
+	u32 hcc_params;
+
+	spin_lock_init(&oxu->lock);
+
+	init_timer(&oxu->watchdog);
+	oxu->watchdog.function = oxu_watchdog;
+	oxu->watchdog.data = (unsigned long) oxu;
+
+	/*
+	 * hw default: 1K periodic list heads, one per frame.
+	 * periodic_size can shrink by USBCMD update if hcc_params allows.
+	 */
+	oxu->periodic_size = DEFAULT_I_TDPS;
+	retval = ehci_mem_init(oxu, GFP_KERNEL);
+	if (retval < 0)
+		return retval;
+
+	/* controllers may cache some of the periodic schedule ... */
+	hcc_params = readl(&oxu->caps->hcc_params);
+	if (HCC_ISOC_CACHE(hcc_params))		/* full frame cache */
+		oxu->i_thresh = 8;
+	else					/* N microframes cached */
+		oxu->i_thresh = 2 + HCC_ISOC_THRES(hcc_params);
+
+	oxu->reclaim = NULL;
+	oxu->reclaim_ready = 0;
+	oxu->next_uframe = -1;
+
+	/*
+	 * dedicate a qh for the async ring head, since we couldn't unlink
+	 * a 'real' qh without stopping the async schedule [4.8].  use it
+	 * as the 'reclamation list head' too.
+	 * its dummy is used in hw_alt_next of many tds, to prevent the qh
+	 * from automatically advancing to the next td after short reads.
+	 */
+	oxu->async->qh_next.qh = NULL;
+	oxu->async->hw_next = QH_NEXT(oxu->async->qh_dma);
+	oxu->async->hw_info1 = cpu_to_le32(QH_HEAD);
+	oxu->async->hw_token = cpu_to_le32(QTD_STS_HALT);
+	oxu->async->hw_qtd_next = EHCI_LIST_END;
+	oxu->async->qh_state = QH_STATE_LINKED;
+	oxu->async->hw_alt_next = QTD_NEXT(oxu->async->dummy->qtd_dma);
+
+	/* clear interrupt enables, set irq latency */
+	if (log2_irq_thresh < 0 || log2_irq_thresh > 6)
+		log2_irq_thresh = 0;
+	temp = 1 << (16 + log2_irq_thresh);
+	if (HCC_CANPARK(hcc_params)) {
+		/* HW default park == 3, on hardware that supports it (like
+		 * NVidia and ALI silicon), maximizes throughput on the async
+		 * schedule by avoiding QH fetches between transfers.
+		 *
+		 * With fast usb storage devices and NForce2, "park" seems to
+		 * make problems:  throughput reduction (!), data errors...
+		 */
+		if (park) {
+			park = min(park, (unsigned) 3);
+			temp |= CMD_PARK;
+			temp |= park << 8;
+		}
+		oxu_dbg(oxu, "park %d\n", park);
+	}
+	if (HCC_PGM_FRAMELISTLEN(hcc_params)) {
+		/* periodic schedule size can be smaller than default */
+		temp &= ~(3 << 2);
+		temp |= (EHCI_TUNE_FLS << 2);
+	}
+	oxu->command = temp;
+
+	return 0;
+}
+
+/* Called during probe() after chip reset completes.
+ */
+static int oxu_reset(struct usb_hcd *hcd)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+	int ret;
+
+	spin_lock_init(&oxu->mem_lock);
+	INIT_LIST_HEAD(&oxu->urb_list);
+	oxu->urb_len = 0;
+
+	/* FIMXE */
+	hcd->self.controller->dma_mask = 0UL;
+
+	if (oxu->is_otg) {
+		oxu->caps = hcd->regs + OXU_OTG_CAP_OFFSET;
+		oxu->regs = hcd->regs + OXU_OTG_CAP_OFFSET + \
+			HC_LENGTH(readl(&oxu->caps->hc_capbase));
+
+		oxu->mem = hcd->regs + OXU_SPH_MEM;
+	} else {
+		oxu->caps = hcd->regs + OXU_SPH_CAP_OFFSET;
+		oxu->regs = hcd->regs + OXU_SPH_CAP_OFFSET + \
+			HC_LENGTH(readl(&oxu->caps->hc_capbase));
+
+		oxu->mem = hcd->regs + OXU_OTG_MEM;
+	}
+
+	oxu->hcs_params = readl(&oxu->caps->hcs_params);
+	oxu->sbrn = 0x20;
+
+	ret = oxu_hcd_init(hcd);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int oxu_run(struct usb_hcd *hcd)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+	int retval;
+	u32 temp, hcc_params;
+
+	hcd->uses_new_polling = 1;
+	hcd->poll_rh = 0;
+
+	/* EHCI spec section 4.1 */
+	retval = ehci_reset(oxu);
+	if (retval != 0) {
+		ehci_mem_cleanup(oxu);
+		return retval;
+	}
+	writel(oxu->periodic_dma, &oxu->regs->frame_list);
+	writel((u32) oxu->async->qh_dma, &oxu->regs->async_next);
+
+	/* hcc_params controls whether oxu->regs->segment must (!!!)
+	 * be used; it constrains QH/ITD/SITD and QTD locations.
+	 * pci_pool consistent memory always uses segment zero.
+	 * streaming mappings for I/O buffers, like pci_map_single(),
+	 * can return segments above 4GB, if the device allows.
+	 *
+	 * NOTE:  the dma mask is visible through dma_supported(), so
+	 * drivers can pass this info along ... like NETIF_F_HIGHDMA,
+	 * Scsi_Host.highmem_io, and so forth.  It's readonly to all
+	 * host side drivers though.
+	 */
+	hcc_params = readl(&oxu->caps->hcc_params);
+	if (HCC_64BIT_ADDR(hcc_params))
+		writel(0, &oxu->regs->segment);
+
+	oxu->command &= ~(CMD_LRESET | CMD_IAAD | CMD_PSE |
+				CMD_ASE | CMD_RESET);
+	oxu->command |= CMD_RUN;
+	writel(oxu->command, &oxu->regs->command);
+	dbg_cmd(oxu, "init", oxu->command);
+
+	/*
+	 * Start, enabling full USB 2.0 functionality ... usb 1.1 devices
+	 * are explicitly handed to companion controller(s), so no TT is
+	 * involved with the root hub.  (Except where one is integrated,
+	 * and there's no companion controller unless maybe for USB OTG.)
+	 */
+	hcd->state = HC_STATE_RUNNING;
+	writel(FLAG_CF, &oxu->regs->configured_flag);
+	readl(&oxu->regs->command);	/* unblock posted writes */
+
+	temp = HC_VERSION(readl(&oxu->caps->hc_capbase));
+	oxu_info(oxu, "USB %x.%x started, quasi-EHCI %x.%02x, driver %s%s\n",
+		((oxu->sbrn & 0xf0)>>4), (oxu->sbrn & 0x0f),
+		temp >> 8, temp & 0xff, DRIVER_VERSION,
+		ignore_oc ? ", overcurrent ignored" : "");
+
+	writel(INTR_MASK, &oxu->regs->intr_enable); /* Turn On Interrupts */
+
+	return 0;
+}
+
+static void oxu_stop(struct usb_hcd *hcd)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+
+	/* Turn off port power on all root hub ports. */
+	ehci_port_power(oxu, 0);
+
+	/* no more interrupts ... */
+	del_timer_sync(&oxu->watchdog);
+
+	spin_lock_irq(&oxu->lock);
+	if (HC_IS_RUNNING(hcd->state))
+		ehci_quiesce(oxu);
+
+	ehci_reset(oxu);
+	writel(0, &oxu->regs->intr_enable);
+	spin_unlock_irq(&oxu->lock);
+
+	/* let companion controllers work when we aren't */
+	writel(0, &oxu->regs->configured_flag);
+
+	/* root hub is shut down separately (first, when possible) */
+	spin_lock_irq(&oxu->lock);
+	if (oxu->async)
+		ehci_work(oxu);
+	spin_unlock_irq(&oxu->lock);
+	ehci_mem_cleanup(oxu);
+
+	dbg_status(oxu, "oxu_stop completed", readl(&oxu->regs->status));
+}
+
+/* Kick in for silicon on any bus (not just pci, etc).
+ * This forcibly disables dma and IRQs, helping kexec and other cases
+ * where the next system software may expect clean state.
+ */
+static void oxu_shutdown(struct usb_hcd *hcd)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+
+	(void) ehci_halt(oxu);
+	ehci_turn_off_all_ports(oxu);
+
+	/* make BIOS/etc use companion controller during reboot */
+	writel(0, &oxu->regs->configured_flag);
+
+	/* unblock posted writes */
+	readl(&oxu->regs->configured_flag);
+}
+
+/* Non-error returns are a promise to giveback() the urb later
+ * we drop ownership so next owner (or urb unlink) can get it
+ *
+ * urb + dev is in hcd.self.controller.urb_list
+ * we're queueing TDs onto software and hardware lists
+ *
+ * hcd-specific init for hcpriv hasn't been done yet
+ *
+ * NOTE:  control, bulk, and interrupt share the same code to append TDs
+ * to a (possibly active) QH, and the same QH scanning code.
+ */
+static int __oxu_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
+				gfp_t mem_flags)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+	struct list_head qtd_list;
+
+	INIT_LIST_HEAD(&qtd_list);
+
+	switch (usb_pipetype(urb->pipe)) {
+	case PIPE_CONTROL:
+	case PIPE_BULK:
+	default:
+		if (!qh_urb_transaction(oxu, urb, &qtd_list, mem_flags))
+			return -ENOMEM;
+		return submit_async(oxu, urb, &qtd_list, mem_flags);
+
+	case PIPE_INTERRUPT:
+		if (!qh_urb_transaction(oxu, urb, &qtd_list, mem_flags))
+			return -ENOMEM;
+		return intr_submit(oxu, urb, &qtd_list, mem_flags);
+
+	case PIPE_ISOCHRONOUS:
+		if (urb->dev->speed == USB_SPEED_HIGH)
+			return itd_submit(oxu, urb, mem_flags);
+		else
+			return sitd_submit(oxu, urb, mem_flags);
+	}
+}
+
+/* This function is responsible for breaking URBs with big data size
+ * into smaller size and processing small urbs in sequence.
+ */
+static int oxu_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
+				gfp_t mem_flags)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+	int num, rem;
+	int transfer_buffer_length;
+	void *transfer_buffer;
+	struct urb *murb;
+	int i, ret;
+
+	/* If not bulk pipe just enqueue the URB */
+	if (!usb_pipebulk(urb->pipe))
+		return __oxu_urb_enqueue(hcd, urb, mem_flags);
+
+	/* Otherwise we should verify the USB transfer buffer size! */
+	transfer_buffer = urb->transfer_buffer;
+	transfer_buffer_length = urb->transfer_buffer_length;
+
+	num = urb->transfer_buffer_length / 4096;
+	rem = urb->transfer_buffer_length % 4096;
+	if (rem != 0)
+		num++;
+
+	/* If URB is smaller than 4096 bytes just enqueue it! */
+	if (num == 1)
+		return __oxu_urb_enqueue(hcd, urb, mem_flags);
+
+	/* Ok, we have more job to do! :) */
+
+	for (i = 0; i < num - 1; i++) {
+		/* Get free micro URB poll till a free urb is recieved */
+
+		do {
+			murb = (struct urb *) oxu_murb_alloc(oxu);
+			if (!murb)
+				schedule();
+		} while (!murb);
+
+		/* Coping the urb */
+		memcpy(murb, urb, sizeof(struct urb));
+
+		murb->transfer_buffer_length = 4096;
+		murb->transfer_buffer = transfer_buffer + i * 4096;
+
+		/* Null pointer for the encodes that this is a micro urb */
+		murb->complete = NULL;
+
+		((struct oxu_murb *) murb)->main = urb;
+		((struct oxu_murb *) murb)->last = 0;
+
+		/* This loop is to guarantee urb to be processed when there's
+		 * not enough resources at a particular time by retrying.
+		 */
+		do {
+			ret  = __oxu_urb_enqueue(hcd, murb, mem_flags);
+			if (ret)
+				schedule();
+		} while (ret);
+	}
+
+	/* Last urb requires special handling  */
+
+	/* Get free micro URB poll till a free urb is recieved */
+	do {
+		murb = (struct urb *) oxu_murb_alloc(oxu);
+		if (!murb)
+			schedule();
+	} while (!murb);
+
+	/* Coping the urb */
+	memcpy(murb, urb, sizeof(struct urb));
+
+	murb->transfer_buffer_length = rem > 0 ? rem : 4096;
+	murb->transfer_buffer = transfer_buffer + (num - 1) * 4096;
+
+	/* Null pointer for the encodes that this is a micro urb */
+	murb->complete = NULL;
+
+	((struct oxu_murb *) murb)->main = urb;
+	((struct oxu_murb *) murb)->last = 1;
+
+	do {
+		ret = __oxu_urb_enqueue(hcd, murb, mem_flags);
+		if (ret)
+			schedule();
+	} while (ret);
+
+	return ret;
+}
+
+/* Remove from hardware lists.
+ * Completions normally happen asynchronously
+ */
+static int oxu_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+	struct ehci_qh *qh;
+	unsigned long flags;
+
+	spin_lock_irqsave(&oxu->lock, flags);
+	switch (usb_pipetype(urb->pipe)) {
+	case PIPE_CONTROL:
+	case PIPE_BULK:
+	default:
+		qh = (struct ehci_qh *) urb->hcpriv;
+		if (!qh)
+			break;
+		unlink_async(oxu, qh);
+		break;
+
+	case PIPE_INTERRUPT:
+		qh = (struct ehci_qh *) urb->hcpriv;
+		if (!qh)
+			break;
+		switch (qh->qh_state) {
+		case QH_STATE_LINKED:
+			intr_deschedule(oxu, qh);
+			/* FALL THROUGH */
+		case QH_STATE_IDLE:
+			qh_completions(oxu, qh);
+			break;
+		default:
+			oxu_dbg(oxu, "bogus qh %p state %d\n",
+					qh, qh->qh_state);
+			goto done;
+		}
+
+		/* reschedule QH iff another request is queued */
+		if (!list_empty(&qh->qtd_list)
+				&& HC_IS_RUNNING(hcd->state)) {
+			int status;
+
+			status = qh_schedule(oxu, qh);
+			spin_unlock_irqrestore(&oxu->lock, flags);
+
+			if (status != 0) {
+				/* shouldn't happen often, but ...
+				 * FIXME kill those tds' urbs
+				 */
+				err("can't reschedule qh %p, err %d",
+					qh, status);
+			}
+			return status;
+		}
+		break;
+	}
+done:
+	spin_unlock_irqrestore(&oxu->lock, flags);
+	return 0;
+}
+
+/* Bulk qh holds the data toggle */
+static void oxu_endpoint_disable(struct usb_hcd *hcd,
+					struct usb_host_endpoint *ep)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+	unsigned long		flags;
+	struct ehci_qh		*qh, *tmp;
+
+	/* ASSERT:  any requests/urbs are being unlinked */
+	/* ASSERT:  nobody can be submitting urbs for this any more */
+
+rescan:
+	spin_lock_irqsave(&oxu->lock, flags);
+	qh = ep->hcpriv;
+	if (!qh)
+		goto done;
+
+	/* endpoints can be iso streams.  for now, we don't
+	 * accelerate iso completions ... so spin a while.
+	 */
+	if (qh->hw_info1 == 0) {
+		oxu_vdbg(oxu, "iso delay\n");
+		goto idle_timeout;
+	}
+
+	if (!HC_IS_RUNNING(hcd->state))
+		qh->qh_state = QH_STATE_IDLE;
+	switch (qh->qh_state) {
+	case QH_STATE_LINKED:
+		for (tmp = oxu->async->qh_next.qh;
+				tmp && tmp != qh;
+				tmp = tmp->qh_next.qh)
+			continue;
+		/* periodic qh self-unlinks on empty */
+		if (!tmp)
+			goto nogood;
+		unlink_async(oxu, qh);
+		/* FALL THROUGH */
+	case QH_STATE_UNLINK:		/* wait for hw to finish? */
+idle_timeout:
+		spin_unlock_irqrestore(&oxu->lock, flags);
+		schedule_timeout_uninterruptible(1);
+		goto rescan;
+	case QH_STATE_IDLE:		/* fully unlinked */
+		if (list_empty(&qh->qtd_list)) {
+			qh_put(qh);
+			break;
+		}
+		/* else FALL THROUGH */
+	default:
+nogood:
+		/* caller was supposed to have unlinked any requests;
+		 * that's not our job.  just leak this memory.
+		 */
+		oxu_err(oxu, "qh %p (#%02x) state %d%s\n",
+			qh, ep->desc.bEndpointAddress, qh->qh_state,
+			list_empty(&qh->qtd_list) ? "" : "(has tds)");
+		break;
+	}
+	ep->hcpriv = NULL;
+done:
+	spin_unlock_irqrestore(&oxu->lock, flags);
+	return;
+}
+
+static int oxu_get_frame(struct usb_hcd *hcd)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+
+	return (readl(&oxu->regs->frame_index) >> 3) %
+		oxu->periodic_size;
+}
+
+/* Build "status change" packet (one or two bytes) from HC registers */
+static int oxu_hub_status_data(struct usb_hcd *hcd, char *buf)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+	u32 temp, mask, status = 0;
+	int ports, i, retval = 1;
+	unsigned long flags;
+
+	/* if !USB_SUSPEND, root hub timers won't get shut down ... */
+	if (!HC_IS_RUNNING(hcd->state))
+		return 0;
+
+	/* init status to no-changes */
+	buf[0] = 0;
+	ports = HCS_N_PORTS(oxu->hcs_params);
+	if (ports > 7) {
+		buf[1] = 0;
+		retval++;
+	}
+
+	/* Some boards (mostly VIA?) report bogus overcurrent indications,
+	 * causing massive log spam unless we completely ignore them.  It
+	 * may be relevant that VIA VT8235 controlers, where PORT_POWER is
+	 * always set, seem to clear PORT_OCC and PORT_CSC when writing to
+	 * PORT_POWER; that's surprising, but maybe within-spec.
+	 */
+	if (!ignore_oc)
+		mask = PORT_CSC | PORT_PEC | PORT_OCC;
+	else
+		mask = PORT_CSC | PORT_PEC;
+
+	/* no hub change reports (bit 0) for now (power, ...) */
+
+	/* port N changes (bit N)? */
+	spin_lock_irqsave(&oxu->lock, flags);
+	for (i = 0; i < ports; i++) {
+		temp = readl(&oxu->regs->port_status[i]);
+
+		/*
+		 * Return status information even for ports with OWNER set.
+		 * Otherwise khubd wouldn't see the disconnect event when a
+		 * high-speed device is switched over to the companion
+		 * controller by the user.
+		 */
+
+		if (!(temp & PORT_CONNECT))
+			oxu->reset_done[i] = 0;
+		if ((temp & mask) != 0 || ((temp & PORT_RESUME) != 0 &&
+				time_after_eq(jiffies, oxu->reset_done[i]))) {
+			if (i < 7)
+				buf[0] |= 1 << (i + 1);
+			else
+				buf[1] |= 1 << (i - 7);
+			status = STS_PCD;
+		}
+	}
+	/* FIXME autosuspend idle root hubs */
+	spin_unlock_irqrestore(&oxu->lock, flags);
+	return status ? retval : 0;
+}
+
+/* Returns the speed of a device attached to a port on the root hub. */
+static inline unsigned int oxu_port_speed(struct oxu_hcd *oxu,
+						unsigned int portsc)
+{
+	switch ((portsc >> 26) & 3) {
+	case 0:
+		return 0;
+	case 1:
+		return 1 << USB_PORT_FEAT_LOWSPEED;
+	case 2:
+	default:
+		return 1 << USB_PORT_FEAT_HIGHSPEED;
+	}
+}
+
+#define	PORT_WAKE_BITS	(PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E)
+static int oxu_hub_control(struct usb_hcd *hcd, u16 typeReq,
+				u16 wValue, u16 wIndex, char *buf, u16 wLength)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+	int ports = HCS_N_PORTS(oxu->hcs_params);
+	u32 __iomem *status_reg = &oxu->regs->port_status[wIndex - 1];
+	u32 temp, status;
+	unsigned long	flags;
+	int retval = 0;
+	unsigned selector;
+
+	/*
+	 * FIXME:  support SetPortFeatures USB_PORT_FEAT_INDICATOR.
+	 * HCS_INDICATOR may say we can change LEDs to off/amber/green.
+	 * (track current state ourselves) ... blink for diagnostics,
+	 * power, "this is the one", etc.  EHCI spec supports this.
+	 */
+
+	spin_lock_irqsave(&oxu->lock, flags);
+	switch (typeReq) {
+	case ClearHubFeature:
+		switch (wValue) {
+		case C_HUB_LOCAL_POWER:
+		case C_HUB_OVER_CURRENT:
+			/* no hub-wide feature/status flags */
+			break;
+		default:
+			goto error;
+		}
+		break;
+	case ClearPortFeature:
+		if (!wIndex || wIndex > ports)
+			goto error;
+		wIndex--;
+		temp = readl(status_reg);
+
+		/*
+		 * Even if OWNER is set, so the port is owned by the
+		 * companion controller, khubd needs to be able to clear
+		 * the port-change status bits (especially
+		 * USB_PORT_FEAT_C_CONNECTION).
+		 */
+
+		switch (wValue) {
+		case USB_PORT_FEAT_ENABLE:
+			writel(temp & ~PORT_PE, status_reg);
+			break;
+		case USB_PORT_FEAT_C_ENABLE:
+			writel((temp & ~PORT_RWC_BITS) | PORT_PEC, status_reg);
+			break;
+		case USB_PORT_FEAT_SUSPEND:
+			if (temp & PORT_RESET)
+				goto error;
+			if (temp & PORT_SUSPEND) {
+				if ((temp & PORT_PE) == 0)
+					goto error;
+				/* resume signaling for 20 msec */
+				temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
+				writel(temp | PORT_RESUME, status_reg);
+				oxu->reset_done[wIndex] = jiffies
+						+ msecs_to_jiffies(20);
+			}
+			break;
+		case USB_PORT_FEAT_C_SUSPEND:
+			/* we auto-clear this feature */
+			break;
+		case USB_PORT_FEAT_POWER:
+			if (HCS_PPC(oxu->hcs_params))
+				writel(temp & ~(PORT_RWC_BITS | PORT_POWER),
+					  status_reg);
+			break;
+		case USB_PORT_FEAT_C_CONNECTION:
+			writel((temp & ~PORT_RWC_BITS) | PORT_CSC, status_reg);
+			break;
+		case USB_PORT_FEAT_C_OVER_CURRENT:
+			writel((temp & ~PORT_RWC_BITS) | PORT_OCC, status_reg);
+			break;
+		case USB_PORT_FEAT_C_RESET:
+			/* GetPortStatus clears reset */
+			break;
+		default:
+			goto error;
+		}
+		readl(&oxu->regs->command);	/* unblock posted write */
+		break;
+	case GetHubDescriptor:
+		ehci_hub_descriptor(oxu, (struct usb_hub_descriptor *)
+			buf);
+		break;
+	case GetHubStatus:
+		/* no hub-wide feature/status flags */
+		memset(buf, 0, 4);
+		break;
+	case GetPortStatus:
+		if (!wIndex || wIndex > ports)
+			goto error;
+		wIndex--;
+		status = 0;
+		temp = readl(status_reg);
+
+		/* wPortChange bits */
+		if (temp & PORT_CSC)
+			status |= 1 << USB_PORT_FEAT_C_CONNECTION;
+		if (temp & PORT_PEC)
+			status |= 1 << USB_PORT_FEAT_C_ENABLE;
+		if ((temp & PORT_OCC) && !ignore_oc)
+			status |= 1 << USB_PORT_FEAT_C_OVER_CURRENT;
+
+		/* whoever resumes must GetPortStatus to complete it!! */
+		if (temp & PORT_RESUME) {
+
+			/* Remote Wakeup received? */
+			if (!oxu->reset_done[wIndex]) {
+				/* resume signaling for 20 msec */
+				oxu->reset_done[wIndex] = jiffies
+						+ msecs_to_jiffies(20);
+				/* check the port again */
+				mod_timer(&oxu_to_hcd(oxu)->rh_timer,
+						oxu->reset_done[wIndex]);
+			}
+
+			/* resume completed? */
+			else if (time_after_eq(jiffies,
+					oxu->reset_done[wIndex])) {
+				status |= 1 << USB_PORT_FEAT_C_SUSPEND;
+				oxu->reset_done[wIndex] = 0;
+
+				/* stop resume signaling */
+				temp = readl(status_reg);
+				writel(temp & ~(PORT_RWC_BITS | PORT_RESUME),
+					status_reg);
+				retval = handshake(oxu, status_reg,
+					   PORT_RESUME, 0, 2000 /* 2msec */);
+				if (retval != 0) {
+					oxu_err(oxu,
+						"port %d resume error %d\n",
+						wIndex + 1, retval);
+					goto error;
+				}
+				temp &= ~(PORT_SUSPEND|PORT_RESUME|(3<<10));
+			}
+		}
+
+		/* whoever resets must GetPortStatus to complete it!! */
+		if ((temp & PORT_RESET)
+				&& time_after_eq(jiffies,
+					oxu->reset_done[wIndex])) {
+			status |= 1 << USB_PORT_FEAT_C_RESET;
+			oxu->reset_done[wIndex] = 0;
+
+			/* force reset to complete */
+			writel(temp & ~(PORT_RWC_BITS | PORT_RESET),
+					status_reg);
+			/* REVISIT:  some hardware needs 550+ usec to clear
+			 * this bit; seems too long to spin routinely...
+			 */
+			retval = handshake(oxu, status_reg,
+					PORT_RESET, 0, 750);
+			if (retval != 0) {
+				oxu_err(oxu, "port %d reset error %d\n",
+					wIndex + 1, retval);
+				goto error;
+			}
+
+			/* see what we found out */
+			temp = check_reset_complete(oxu, wIndex, status_reg,
+					readl(status_reg));
+		}
+
+		/* transfer dedicated ports to the companion hc */
+		if ((temp & PORT_CONNECT) &&
+				test_bit(wIndex, &oxu->companion_ports)) {
+			temp &= ~PORT_RWC_BITS;
+			temp |= PORT_OWNER;
+			writel(temp, status_reg);
+			oxu_dbg(oxu, "port %d --> companion\n", wIndex + 1);
+			temp = readl(status_reg);
+		}
+
+		/*
+		 * Even if OWNER is set, there's no harm letting khubd
+		 * see the wPortStatus values (they should all be 0 except
+		 * for PORT_POWER anyway).
+		 */
+
+		if (temp & PORT_CONNECT) {
+			status |= 1 << USB_PORT_FEAT_CONNECTION;
+			/* status may be from integrated TT */
+			status |= oxu_port_speed(oxu, temp);
+		}
+		if (temp & PORT_PE)
+			status |= 1 << USB_PORT_FEAT_ENABLE;
+		if (temp & (PORT_SUSPEND|PORT_RESUME))
+			status |= 1 << USB_PORT_FEAT_SUSPEND;
+		if (temp & PORT_OC)
+			status |= 1 << USB_PORT_FEAT_OVER_CURRENT;
+		if (temp & PORT_RESET)
+			status |= 1 << USB_PORT_FEAT_RESET;
+		if (temp & PORT_POWER)
+			status |= 1 << USB_PORT_FEAT_POWER;
+
+#ifndef	OXU_VERBOSE_DEBUG
+	if (status & ~0xffff)	/* only if wPortChange is interesting */
+#endif
+		dbg_port(oxu, "GetStatus", wIndex + 1, temp);
+		put_unaligned(cpu_to_le32(status), (__le32 *) buf);
+		break;
+	case SetHubFeature:
+		switch (wValue) {
+		case C_HUB_LOCAL_POWER:
+		case C_HUB_OVER_CURRENT:
+			/* no hub-wide feature/status flags */
+			break;
+		default:
+			goto error;
+		}
+		break;
+	case SetPortFeature:
+		selector = wIndex >> 8;
+		wIndex &= 0xff;
+		if (!wIndex || wIndex > ports)
+			goto error;
+		wIndex--;
+		temp = readl(status_reg);
+		if (temp & PORT_OWNER)
+			break;
+
+		temp &= ~PORT_RWC_BITS;
+		switch (wValue) {
+		case USB_PORT_FEAT_SUSPEND:
+			if ((temp & PORT_PE) == 0
+					|| (temp & PORT_RESET) != 0)
+				goto error;
+			if (device_may_wakeup(&hcd->self.root_hub->dev))
+				temp |= PORT_WAKE_BITS;
+			writel(temp | PORT_SUSPEND, status_reg);
+			break;
+		case USB_PORT_FEAT_POWER:
+			if (HCS_PPC(oxu->hcs_params))
+				writel(temp | PORT_POWER, status_reg);
+			break;
+		case USB_PORT_FEAT_RESET:
+			if (temp & PORT_RESUME)
+				goto error;
+			/* line status bits may report this as low speed,
+			 * which can be fine if this root hub has a
+			 * transaction translator built in.
+			 */
+			oxu_vdbg(oxu, "port %d reset\n", wIndex + 1);
+			temp |= PORT_RESET;
+			temp &= ~PORT_PE;
+
+			/*
+			 * caller must wait, then call GetPortStatus
+			 * usb 2.0 spec says 50 ms resets on root
+			 */
+			oxu->reset_done[wIndex] = jiffies
+					+ msecs_to_jiffies(50);
+			writel(temp, status_reg);
+			break;
+
+		/* For downstream facing ports (these):  one hub port is put
+		 * into test mode according to USB2 11.24.2.13, then the hub
+		 * must be reset (which for root hub now means rmmod+modprobe,
+		 * or else system reboot).  See EHCI 2.3.9 and 4.14 for info
+		 * about the EHCI-specific stuff.
+		 */
+		case USB_PORT_FEAT_TEST:
+			if (!selector || selector > 5)
+				goto error;
+			ehci_quiesce(oxu);
+			ehci_halt(oxu);
+			temp |= selector << 16;
+			writel(temp, status_reg);
+			break;
+
+		default:
+			goto error;
+		}
+		readl(&oxu->regs->command);	/* unblock posted writes */
+		break;
+
+	default:
+error:
+		/* "stall" on error */
+		retval = -EPIPE;
+	}
+	spin_unlock_irqrestore(&oxu->lock, flags);
+	return retval;
+}
+
+#ifdef CONFIG_PM
+
+static int oxu_bus_suspend(struct usb_hcd *hcd)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+	int port;
+	int mask;
+
+	oxu_dbg(oxu, "suspend root hub\n");
+
+	if (time_before(jiffies, oxu->next_statechange))
+		msleep(5);
+
+	port = HCS_N_PORTS(oxu->hcs_params);
+	spin_lock_irq(&oxu->lock);
+
+	/* stop schedules, clean any completed work */
+	if (HC_IS_RUNNING(hcd->state)) {
+		ehci_quiesce(oxu);
+		hcd->state = HC_STATE_QUIESCING;
+	}
+	oxu->command = readl(&oxu->regs->command);
+	if (oxu->reclaim)
+		oxu->reclaim_ready = 1;
+	ehci_work(oxu);
+
+	/* Unlike other USB host controller types, EHCI doesn't have
+	 * any notion of "global" or bus-wide suspend.  The driver has
+	 * to manually suspend all the active unsuspended ports, and
+	 * then manually resume them in the bus_resume() routine.
+	 */
+	oxu->bus_suspended = 0;
+	while (port--) {
+		u32 __iomem *reg = &oxu->regs->port_status[port];
+		u32 t1 = readl(reg) & ~PORT_RWC_BITS;
+		u32 t2 = t1;
+
+		/* keep track of which ports we suspend */
+		if ((t1 & PORT_PE) && !(t1 & PORT_OWNER) &&
+				!(t1 & PORT_SUSPEND)) {
+			t2 |= PORT_SUSPEND;
+			set_bit(port, &oxu->bus_suspended);
+		}
+
+		/* enable remote wakeup on all ports */
+		if (device_may_wakeup(&hcd->self.root_hub->dev))
+			t2 |= PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E;
+		else
+			t2 &= ~(PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E);
+
+		if (t1 != t2) {
+			oxu_vdbg(oxu, "port %d, %08x -> %08x\n",
+				port + 1, t1, t2);
+			writel(t2, reg);
+		}
+	}
+
+	/* turn off now-idle HC */
+	del_timer_sync(&oxu->watchdog);
+	ehci_halt(oxu);
+	hcd->state = HC_STATE_SUSPENDED;
+
+	/* allow remote wakeup */
+	mask = INTR_MASK;
+	if (!device_may_wakeup(&hcd->self.root_hub->dev))
+		mask &= ~STS_PCD;
+	writel(mask, &oxu->regs->intr_enable);
+	readl(&oxu->regs->intr_enable);
+
+	oxu->next_statechange = jiffies + msecs_to_jiffies(10);
+	spin_unlock_irq(&oxu->lock);
+	return 0;
+}
+
+/* Caller has locked the root hub, and should reset/reinit on error */
+static int oxu_bus_resume(struct usb_hcd *hcd)
+{
+	struct oxu_hcd *oxu = hcd_to_oxu(hcd);
+	u32 temp;
+	int i;
+
+	if (time_before(jiffies, oxu->next_statechange))
+		msleep(5);
+	spin_lock_irq(&oxu->lock);
+
+	/* Ideally and we've got a real resume here, and no port's power
+	 * was lost.  (For PCI, that means Vaux was maintained.)  But we
+	 * could instead be restoring a swsusp snapshot -- so that BIOS was
+	 * the last user of the controller, not reset/pm hardware keeping
+	 * state we gave to it.
+	 */
+	temp = readl(&oxu->regs->intr_enable);
+	oxu_dbg(oxu, "resume root hub%s\n", temp ? "" : " after power loss");
+
+	/* at least some APM implementations will try to deliver
+	 * IRQs right away, so delay them until we're ready.
+	 */
+	writel(0, &oxu->regs->intr_enable);
+
+	/* re-init operational registers */
+	writel(0, &oxu->regs->segment);
+	writel(oxu->periodic_dma, &oxu->regs->frame_list);
+	writel((u32) oxu->async->qh_dma, &oxu->regs->async_next);
+
+	/* restore CMD_RUN, framelist size, and irq threshold */
+	writel(oxu->command, &oxu->regs->command);
+
+	/* Some controller/firmware combinations need a delay during which
+	 * they set up the port statuses.  See Bugzilla #8190. */
+	mdelay(8);
+
+	/* manually resume the ports we suspended during bus_suspend() */
+	i = HCS_N_PORTS(oxu->hcs_params);
+	while (i--) {
+		temp = readl(&oxu->regs->port_status[i]);
+		temp &= ~(PORT_RWC_BITS
+			| PORT_WKOC_E | PORT_WKDISC_E | PORT_WKCONN_E);
+		if (test_bit(i, &oxu->bus_suspended) && (temp & PORT_SUSPEND)) {
+			oxu->reset_done[i] = jiffies + msecs_to_jiffies(20);
+			temp |= PORT_RESUME;
+		}
+		writel(temp, &oxu->regs->port_status[i]);
+	}
+	i = HCS_N_PORTS(oxu->hcs_params);
+	mdelay(20);
+	while (i--) {
+		temp = readl(&oxu->regs->port_status[i]);
+		if (test_bit(i, &oxu->bus_suspended) && (temp & PORT_SUSPEND)) {
+			temp &= ~(PORT_RWC_BITS | PORT_RESUME);
+			writel(temp, &oxu->regs->port_status[i]);
+			oxu_vdbg(oxu, "resumed port %d\n", i + 1);
+		}
+	}
+	(void) readl(&oxu->regs->command);
+
+	/* maybe re-activate the schedule(s) */
+	temp = 0;
+	if (oxu->async->qh_next.qh)
+		temp |= CMD_ASE;
+	if (oxu->periodic_sched)
+		temp |= CMD_PSE;
+	if (temp) {
+		oxu->command |= temp;
+		writel(oxu->command, &oxu->regs->command);
+	}
+
+	oxu->next_statechange = jiffies + msecs_to_jiffies(5);
+	hcd->state = HC_STATE_RUNNING;
+
+	/* Now we can safely re-enable irqs */
+	writel(INTR_MASK, &oxu->regs->intr_enable);
+
+	spin_unlock_irq(&oxu->lock);
+	return 0;
+}
+
+#else
+
+static int oxu_bus_suspend(struct usb_hcd *hcd)
+{
+	return 0;
+}
+
+static int oxu_bus_resume(struct usb_hcd *hcd)
+{
+	return 0;
+}
+
+#endif	/* CONFIG_PM */
+
+static const struct hc_driver oxu_hc_driver = {
+	.description =		"oxu210hp_hcd",
+	.product_desc =		"oxu210hp HCD",
+	.hcd_priv_size =	sizeof(struct oxu_hcd),
+
+	/*
+	 * Generic hardware linkage
+	 */
+	.irq =			oxu_irq,
+	.flags =		HCD_MEMORY | HCD_USB2,
+
+	/*
+	 * Basic lifecycle operations
+	 */
+	.reset =		oxu_reset,
+	.start =		oxu_run,
+	.stop =			oxu_stop,
+	.shutdown =		oxu_shutdown,
+
+	/*
+	 * Managing i/o requests and associated device resources
+	 */
+	.urb_enqueue =		oxu_urb_enqueue,
+	.urb_dequeue =		oxu_urb_dequeue,
+	.endpoint_disable =	oxu_endpoint_disable,
+
+	/*
+	 * Scheduling support
+	 */
+	.get_frame_number =	oxu_get_frame,
+
+	/*
+	 * Root hub support
+	 */
+	.hub_status_data =	oxu_hub_status_data,
+	.hub_control =		oxu_hub_control,
+	.bus_suspend =		oxu_bus_suspend,
+	.bus_resume =		oxu_bus_resume,
+};
+
+/*
+ * Module stuff
+ */
+
+static void oxu_configuration(struct platform_device *pdev, void *base)
+{
+	u32 tmp;
+
+	/* Initialize top level registers.
+	 * First write ever
+	 */
+	oxu_writel(base, OXU_HOSTIFCONFIG, 0x0000037D);
+	oxu_writel(base, OXU_SOFTRESET, OXU_SRESET);
+	oxu_writel(base, OXU_HOSTIFCONFIG, 0x0000037D);
+
+	tmp = oxu_readl(base, OXU_PIOBURSTREADCTRL);
+	oxu_writel(base, OXU_PIOBURSTREADCTRL, tmp | 0x0040);
+
+	oxu_writel(base, OXU_ASO, OXU_SPHPOEN | OXU_OVRCCURPUPDEN |
+					OXU_COMPARATOR | OXU_ASO_OP);
+
+	tmp = oxu_readl(base, OXU_CLKCTRL_SET);
+	oxu_writel(base, OXU_CLKCTRL_SET, tmp | OXU_SYSCLKEN | OXU_USBOTGCLKEN);
+
+	/* Clear all top interrupt enable */
+	oxu_writel(base, OXU_CHIPIRQEN_CLR, 0xff);
+
+	/* Clear all top interrupt status */
+	oxu_writel(base, OXU_CHIPIRQSTATUS, 0xff);
+
+	/* Enable all needed top interrupt except OTG SPH core */
+	oxu_writel(base, OXU_CHIPIRQEN_SET, OXU_USBSPHLPWUI | OXU_USBOTGLPWUI);
+}
+
+static int oxu_verify_id(struct platform_device *pdev, void *base)
+{
+	u32 id;
+	char *bo[] = {
+		"reserved",
+		"128-pin LQFP",
+		"84-pin TFBGA",
+		"reserved",
+	};
+
+	/* Read controller signature register to find a match */
+	id = oxu_readl(base, OXU_DEVICEID);
+	dev_info(&pdev->dev, "device ID %x\n", id);
+	if ((id & OXU_REV_MASK) != (OXU_REV_2100 << OXU_REV_SHIFT))
+		return -1;
+
+	dev_info(&pdev->dev, "found device %x %s (%04x:%04x)\n",
+		id >> OXU_REV_SHIFT,
+		bo[(id & OXU_BO_MASK) >> OXU_BO_SHIFT],
+		(id & OXU_MAJ_REV_MASK) >> OXU_MAJ_REV_SHIFT,
+		(id & OXU_MIN_REV_MASK) >> OXU_MIN_REV_SHIFT);
+
+	return 0;
+}
+
+static const struct hc_driver oxu_hc_driver;
+static struct usb_hcd *oxu_create(struct platform_device *pdev,
+				unsigned long memstart, unsigned long memlen,
+				void *base, int irq, int otg)
+{
+	struct device *dev = &pdev->dev;
+
+	struct usb_hcd *hcd;
+	struct oxu_hcd *oxu;
+	int ret;
+
+	/* Set endian mode and host mode */
+	oxu_writel(base + (otg ? OXU_OTG_CORE_OFFSET : OXU_SPH_CORE_OFFSET),
+				OXU_USBMODE,
+				OXU_CM_HOST_ONLY | OXU_ES_LITTLE | OXU_VBPS);
+
+	hcd = usb_create_hcd(&oxu_hc_driver, dev,
+				otg ? "oxu210hp_otg" : "oxu210hp_sph");
+	if (!hcd)
+		return ERR_PTR(-ENOMEM);
+
+	hcd->rsrc_start = memstart;
+	hcd->rsrc_len = memlen;
+	hcd->regs = base;
+	hcd->irq = irq;
+	hcd->state = HC_STATE_HALT;
+
+	oxu = hcd_to_oxu(hcd);
+	oxu->is_otg = otg;
+
+	ret = usb_add_hcd(hcd, irq, IRQF_SHARED);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	return hcd;
+}
+
+static int oxu_init(struct platform_device *pdev,
+				unsigned long memstart, unsigned long memlen,
+				void *base, int irq)
+{
+	struct oxu_info *info = platform_get_drvdata(pdev);
+	struct usb_hcd *hcd;
+	int ret;
+
+	/* First time configuration at start up */
+	oxu_configuration(pdev, base);
+
+	ret = oxu_verify_id(pdev, base);
+	if (ret) {
+		dev_err(&pdev->dev, "no devices found!\n");
+		return -ENODEV;
+	}
+
+	/* Create the OTG controller */
+	hcd = oxu_create(pdev, memstart, memlen, base, irq, 1);
+	if (IS_ERR(hcd)) {
+		dev_err(&pdev->dev, "cannot create OTG controller!\n");
+		ret = PTR_ERR(hcd);
+		goto error_create_otg;
+	}
+	info->hcd[0] = hcd;
+
+	/* Create the SPH host controller */
+	hcd = oxu_create(pdev, memstart, memlen, base, irq, 0);
+	if (IS_ERR(hcd)) {
+		dev_err(&pdev->dev, "cannot create SPH controller!\n");
+		ret = PTR_ERR(hcd);
+		goto error_create_sph;
+	}
+	info->hcd[1] = hcd;
+
+	oxu_writel(base, OXU_CHIPIRQEN_SET,
+		oxu_readl(base, OXU_CHIPIRQEN_SET) | 3);
+
+	return 0;
+
+error_create_sph:
+	usb_remove_hcd(info->hcd[0]);
+	usb_put_hcd(info->hcd[0]);
+
+error_create_otg:
+	return ret;
+}
+
+static int oxu_drv_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	void *base;
+	unsigned long memstart, memlen;
+	int irq, ret;
+	struct oxu_info *info;
+
+	if (usb_disabled())
+		return -ENODEV;
+
+	/*
+	 * Get the platform resources
+	 */
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!res) {
+		dev_err(&pdev->dev,
+			"no IRQ! Check %s setup!\n", pdev->dev.bus_id);
+		return -ENODEV;
+	}
+	irq = res->start;
+	dev_dbg(&pdev->dev, "IRQ resource %d\n", irq);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "no registers address! Check %s setup!\n",
+			pdev->dev.bus_id);
+		return -ENODEV;
+	}
+	memstart = res->start;
+	memlen = res->end - res->start + 1;
+	dev_dbg(&pdev->dev, "MEM resource %lx-%lx\n", memstart, memlen);
+	if (!request_mem_region(memstart, memlen,
+				oxu_hc_driver.description)) {
+		dev_dbg(&pdev->dev, "memory area already in use\n");
+		return -EBUSY;
+	}
+
+	ret = set_irq_type(irq, IRQF_TRIGGER_FALLING);
+	if (ret) {
+		dev_err(&pdev->dev, "error setting irq type\n");
+		ret = -EFAULT;
+		goto error_set_irq_type;
+	}
+
+	base = ioremap(memstart, memlen);
+	if (!base) {
+		dev_dbg(&pdev->dev, "error mapping memory\n");
+		ret = -EFAULT;
+		goto error_ioremap;
+	}
+
+	/* Allocate a driver data struct to hold useful info for both
+	 * SPH & OTG devices
+	 */
+	info = kzalloc(sizeof(struct oxu_info), GFP_KERNEL);
+	if (!info) {
+		dev_dbg(&pdev->dev, "error allocating memory\n");
+		ret = -EFAULT;
+		goto error_alloc;
+	}
+	platform_set_drvdata(pdev, info);
+
+	ret = oxu_init(pdev, memstart, memlen, base, irq);
+	if (ret < 0) {
+		dev_dbg(&pdev->dev, "cannot init USB devices\n");
+		goto error_init;
+	}
+
+	dev_info(&pdev->dev, "devices enabled and running\n");
+	platform_set_drvdata(pdev, info);
+
+	return 0;
+
+error_init:
+	kfree(info);
+	platform_set_drvdata(pdev, NULL);
+
+error_alloc:
+	iounmap(base);
+
+error_set_irq_type:
+error_ioremap:
+	release_mem_region(memstart, memlen);
+
+	dev_err(&pdev->dev, "init %s fail, %d\n", pdev->dev.bus_id, ret);
+	return ret;
+}
+
+static void oxu_remove(struct platform_device *pdev, struct usb_hcd *hcd)
+{
+	usb_remove_hcd(hcd);
+	usb_put_hcd(hcd);
+}
+
+static int oxu_drv_remove(struct platform_device *pdev)
+{
+	struct oxu_info *info = platform_get_drvdata(pdev);
+	unsigned long memstart = info->hcd[0]->rsrc_start,
+			memlen = info->hcd[0]->rsrc_len;
+	void *base = info->hcd[0]->regs;
+
+	oxu_remove(pdev, info->hcd[0]);
+	oxu_remove(pdev, info->hcd[1]);
+
+	iounmap(base);
+	release_mem_region(memstart, memlen);
+
+	kfree(info);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static void oxu_drv_shutdown(struct platform_device *pdev)
+{
+	oxu_drv_remove(pdev);
+}
+
+#if 0
+/* FIXME: TODO */
+static int oxu_drv_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct usb_hcd *hcd = dev_get_drvdata(dev);
+
+	return 0;
+}
+
+static int oxu_drv_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct usb_hcd *hcd = dev_get_drvdata(dev);
+
+	return 0;
+}
+#else
+#define oxu_drv_suspend	NULL
+#define oxu_drv_resume	NULL
+#endif
+
+static struct platform_driver oxu_driver = {
+	.probe		= oxu_drv_probe,
+	.remove		= oxu_drv_remove,
+	.shutdown	= oxu_drv_shutdown,
+	.suspend	= oxu_drv_suspend,
+	.resume		= oxu_drv_resume,
+	.driver = {
+		.name = "oxu210hp-hcd",
+		.bus = &platform_bus_type
+	}
+};
+
+static int __init oxu_module_init(void)
+{
+	int retval = 0;
+
+	retval = platform_driver_register(&oxu_driver);
+	if (retval < 0)
+		return retval;
+
+	return retval;
+}
+
+static void __exit oxu_module_cleanup(void)
+{
+	platform_driver_unregister(&oxu_driver);
+}
+
+module_init(oxu_module_init);
+module_exit(oxu_module_cleanup);
+
+MODULE_DESCRIPTION("Oxford OXU210HP HCD driver - ver. " DRIVER_VERSION);
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_LICENSE("GPL");