Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

1 files changed, 838 insertions, 0 deletions

diff --git a/drivers/usb/misc/uss720.c b/drivers/usb/misc/uss720.c
new file mode 100644
index 000000000..1ce48f583
--- /dev/null
+++ b/drivers/usb/misc/uss720.c
@@ -0,0 +1,838 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*****************************************************************************/
+
+/*
+ *	uss720.c  --  USS720 USB Parport Cable.
+ *
+ *	Copyright (C) 1999, 2005, 2010
+ *	    Thomas Sailer (t.sailer@alumni.ethz.ch)
+ *
+ *  Based on parport_pc.c
+ *
+ *  History:
+ *   0.1  04.08.1999  Created
+ *   0.2  07.08.1999  Some fixes mainly suggested by Tim Waugh
+ *		      Interrupt handling currently disabled because
+ *		      usb_request_irq crashes somewhere within ohci.c
+ *		      for no apparent reason (that is for me, anyway)
+ *		      ECP currently untested
+ *   0.3  10.08.1999  fixing merge errors
+ *   0.4  13.08.1999  Added Vendor/Product ID of Brad Hard's cable
+ *   0.5  20.09.1999  usb_control_msg wrapper used
+ *        Nov01.2000  usb_device_table support by Adam J. Richter
+ *        08.04.2001  Identify version on module load.  gb
+ *   0.6  02.09.2005  Fix "scheduling in interrupt" problem by making save/restore
+ *                    context asynchronous
+ *
+ */
+
+/*****************************************************************************/
+
+#include <linux/module.h>
+#include <linux/socket.h>
+#include <linux/parport.h>
+#include <linux/init.h>
+#include <linux/usb.h>
+#include <linux/delay.h>
+#include <linux/completion.h>
+#include <linux/kref.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+
+#define DRIVER_AUTHOR "Thomas M. Sailer, t.sailer@alumni.ethz.ch"
+#define DRIVER_DESC "USB Parport Cable driver for Cables using the Lucent Technologies USS720 Chip"
+
+/* --------------------------------------------------------------------- */
+
+struct parport_uss720_private {
+	struct usb_device *usbdev;
+	struct parport *pp;
+	struct kref ref_count;
+	__u8 reg[7];  /* USB registers */
+	struct list_head asynclist;
+	spinlock_t asynclock;
+};
+
+struct uss720_async_request {
+	struct parport_uss720_private *priv;
+	struct kref ref_count;
+	struct list_head asynclist;
+	struct completion compl;
+	struct urb *urb;
+	struct usb_ctrlrequest *dr;
+	__u8 reg[7];
+};
+
+/* --------------------------------------------------------------------- */
+
+static void destroy_priv(struct kref *kref)
+{
+	struct parport_uss720_private *priv = container_of(kref, struct parport_uss720_private, ref_count);
+
+	dev_dbg(&priv->usbdev->dev, "destroying priv datastructure\n");
+	usb_put_dev(priv->usbdev);
+	priv->usbdev = NULL;
+	kfree(priv);
+}
+
+static void destroy_async(struct kref *kref)
+{
+	struct uss720_async_request *rq = container_of(kref, struct uss720_async_request, ref_count);
+	struct parport_uss720_private *priv = rq->priv;
+	unsigned long flags;
+
+	if (likely(rq->urb))
+		usb_free_urb(rq->urb);
+	kfree(rq->dr);
+	spin_lock_irqsave(&priv->asynclock, flags);
+	list_del_init(&rq->asynclist);
+	spin_unlock_irqrestore(&priv->asynclock, flags);
+	kfree(rq);
+	kref_put(&priv->ref_count, destroy_priv);
+}
+
+/* --------------------------------------------------------------------- */
+
+static void async_complete(struct urb *urb)
+{
+	struct uss720_async_request *rq;
+	struct parport *pp;
+	struct parport_uss720_private *priv;
+	int status = urb->status;
+
+	rq = urb->context;
+	priv = rq->priv;
+	pp = priv->pp;
+	if (status) {
+		dev_err(&urb->dev->dev, "async_complete: urb error %d\n",
+			status);
+	} else if (rq->dr->bRequest == 3) {
+		memcpy(priv->reg, rq->reg, sizeof(priv->reg));
+#if 0
+		dev_dbg(&priv->usbdev->dev, "async_complete regs %7ph\n",
+			priv->reg);
+#endif
+		/* if nAck interrupts are enabled and we have an interrupt, call the interrupt procedure */
+		if (rq->reg[2] & rq->reg[1] & 0x10 && pp)
+			parport_generic_irq(pp);
+	}
+	complete(&rq->compl);
+	kref_put(&rq->ref_count, destroy_async);
+}
+
+static struct uss720_async_request *submit_async_request(struct parport_uss720_private *priv,
+							 __u8 request, __u8 requesttype, __u16 value, __u16 index,
+							 gfp_t mem_flags)
+{
+	struct usb_device *usbdev;
+	struct uss720_async_request *rq;
+	unsigned long flags;
+	int ret;
+
+	if (!priv)
+		return NULL;
+	usbdev = priv->usbdev;
+	if (!usbdev)
+		return NULL;
+	rq = kzalloc_obj(struct uss720_async_request, mem_flags);
+	if (!rq)
+		return NULL;
+	kref_init(&rq->ref_count);
+	INIT_LIST_HEAD(&rq->asynclist);
+	init_completion(&rq->compl);
+	kref_get(&priv->ref_count);
+	rq->priv = priv;
+	rq->urb = usb_alloc_urb(0, mem_flags);
+	if (!rq->urb) {
+		kref_put(&rq->ref_count, destroy_async);
+		return NULL;
+	}
+	rq->dr = kmalloc_obj(*rq->dr, mem_flags);
+	if (!rq->dr) {
+		kref_put(&rq->ref_count, destroy_async);
+		return NULL;
+	}
+	rq->dr->bRequestType = requesttype;
+	rq->dr->bRequest = request;
+	rq->dr->wValue = cpu_to_le16(value);
+	rq->dr->wIndex = cpu_to_le16(index);
+	rq->dr->wLength = cpu_to_le16((request == 3) ? sizeof(rq->reg) : 0);
+	usb_fill_control_urb(rq->urb, usbdev, (requesttype & 0x80) ? usb_rcvctrlpipe(usbdev, 0) : usb_sndctrlpipe(usbdev, 0),
+			     (unsigned char *)rq->dr,
+			     (request == 3) ? rq->reg : NULL, (request == 3) ? sizeof(rq->reg) : 0, async_complete, rq);
+	/* rq->urb->transfer_flags |= URB_ASYNC_UNLINK; */
+	spin_lock_irqsave(&priv->asynclock, flags);
+	list_add_tail(&rq->asynclist, &priv->asynclist);
+	spin_unlock_irqrestore(&priv->asynclock, flags);
+	kref_get(&rq->ref_count);
+	ret = usb_submit_urb(rq->urb, mem_flags);
+	if (!ret)
+		return rq;
+	destroy_async(&rq->ref_count);
+	dev_err(&usbdev->dev, "submit_async_request submit_urb failed with %d\n", ret);
+	return NULL;
+}
+
+static unsigned int kill_all_async_requests_priv(struct parport_uss720_private *priv)
+{
+	struct uss720_async_request *rq;
+	unsigned long flags;
+	unsigned int ret = 0;
+
+	spin_lock_irqsave(&priv->asynclock, flags);
+	list_for_each_entry(rq, &priv->asynclist, asynclist) {
+		usb_unlink_urb(rq->urb);
+		ret++;
+	}
+	spin_unlock_irqrestore(&priv->asynclock, flags);
+	return ret;
+}
+
+/* --------------------------------------------------------------------- */
+
+static int get_1284_register(struct parport *pp, unsigned char reg, unsigned char *val, gfp_t mem_flags)
+{
+	struct parport_uss720_private *priv;
+	struct uss720_async_request *rq;
+	static const unsigned char regindex[9] = {
+		4, 0, 1, 5, 5, 0, 2, 3, 6
+	};
+	int ret;
+
+	if (!pp)
+		return -EIO;
+	priv = pp->private_data;
+	rq = submit_async_request(priv, 3, 0xc0, ((unsigned int)reg) << 8, 0, mem_flags);
+	if (!rq) {
+		dev_err(&priv->usbdev->dev, "get_1284_register(%u) failed",
+			(unsigned int)reg);
+		return -EIO;
+	}
+	if (!val) {
+		kref_put(&rq->ref_count, destroy_async);
+		return 0;
+	}
+	if (wait_for_completion_timeout(&rq->compl, HZ)) {
+		ret = rq->urb->status;
+		*val = priv->reg[(reg >= 9) ? 0 : regindex[reg]];
+		if (ret)
+			printk(KERN_WARNING "get_1284_register: "
+			       "usb error %d\n", ret);
+		kref_put(&rq->ref_count, destroy_async);
+		return ret;
+	}
+	printk(KERN_WARNING "get_1284_register timeout\n");
+	kill_all_async_requests_priv(priv);
+	return -EIO;
+}
+
+static int set_1284_register(struct parport *pp, unsigned char reg, unsigned char val, gfp_t mem_flags)
+{
+	struct parport_uss720_private *priv;
+	struct uss720_async_request *rq;
+
+	if (!pp)
+		return -EIO;
+	priv = pp->private_data;
+	rq = submit_async_request(priv, 4, 0x40, (((unsigned int)reg) << 8) | val, 0, mem_flags);
+	if (!rq) {
+		dev_err(&priv->usbdev->dev, "set_1284_register(%u,%u) failed",
+			(unsigned int)reg, (unsigned int)val);
+		return -EIO;
+	}
+	kref_put(&rq->ref_count, destroy_async);
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+/* ECR modes */
+#define ECR_SPP 00
+#define ECR_PS2 01
+#define ECR_PPF 02
+#define ECR_ECP 03
+#define ECR_EPP 04
+
+/* Safely change the mode bits in the ECR */
+static int change_mode(struct parport *pp, int m)
+{
+	struct parport_uss720_private *priv = pp->private_data;
+	int mode;
+	__u8 reg;
+
+	if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
+		return -EIO;
+	/* Bits <7:5> contain the mode. */
+	mode = (priv->reg[2] >> 5) & 0x7;
+	if (mode == m)
+		return 0;
+	/* We have to go through mode 000 or 001 */
+	if (mode > ECR_PS2 && m > ECR_PS2)
+		if (change_mode(pp, ECR_PS2))
+			return -EIO;
+
+	if (m <= ECR_PS2 && !(priv->reg[1] & 0x20)) {
+		/* This mode resets the FIFO, so we may
+		 * have to wait for it to drain first. */
+		unsigned long expire = jiffies + pp->physport->cad->timeout;
+		switch (mode) {
+		case ECR_PPF: /* Parallel Port FIFO mode */
+		case ECR_ECP: /* ECP Parallel Port mode */
+			/* Poll slowly. */
+			for (;;) {
+				if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
+					return -EIO;
+				if (priv->reg[2] & 0x01)
+					break;
+				if (time_after_eq (jiffies, expire))
+					/* The FIFO is stuck. */
+					return -EBUSY;
+				msleep_interruptible(10);
+				if (signal_pending (current))
+					break;
+			}
+		}
+	}
+	/* Set the mode. */
+	if (set_1284_register(pp, 6, m << 5, GFP_KERNEL))
+		return -EIO;
+	if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
+		return -EIO;
+	return 0;
+}
+
+/*
+ * Clear TIMEOUT BIT in EPP MODE
+ */
+static int clear_epp_timeout(struct parport *pp)
+{
+	unsigned char stat;
+
+	if (get_1284_register(pp, 1, &stat, GFP_KERNEL))
+		return 1;
+	return stat & 1;
+}
+
+/*
+ * Access functions.
+ */
+#if 0
+static int uss720_irq(int usbstatus, void *buffer, int len, void *dev_id)
+{
+	struct parport *pp = (struct parport *)dev_id;
+	struct parport_uss720_private *priv = pp->private_data;	
+
+	if (usbstatus != 0 || len < 4 || !buffer)
+		return 1;
+	memcpy(priv->reg, buffer, 4);
+	/* if nAck interrupts are enabled and we have an interrupt, call the interrupt procedure */
+	if (priv->reg[2] & priv->reg[1] & 0x10)
+		parport_generic_irq(pp);
+	return 1;
+}
+#endif
+
+static void parport_uss720_write_data(struct parport *pp, unsigned char d)
+{
+	set_1284_register(pp, 0, d, GFP_KERNEL);
+}
+
+static unsigned char parport_uss720_read_data(struct parport *pp)
+{
+	unsigned char ret;
+
+	if (get_1284_register(pp, 0, &ret, GFP_KERNEL))
+		return 0;
+	return ret;
+}
+
+static void parport_uss720_write_control(struct parport *pp, unsigned char d)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+
+	d = (d & 0xf) | (priv->reg[1] & 0xf0);
+	if (set_1284_register(pp, 2, d, GFP_KERNEL))
+		return;
+	priv->reg[1] = d;
+}
+
+static unsigned char parport_uss720_read_control(struct parport *pp)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	return priv->reg[1] & 0xf; /* Use soft copy */
+}
+
+static unsigned char parport_uss720_frob_control(struct parport *pp, unsigned char mask, unsigned char val)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	unsigned char d;
+
+	mask &= 0x0f;
+	val &= 0x0f;
+	d = (priv->reg[1] & (~mask)) ^ val;
+	if (set_1284_register(pp, 2, d, GFP_ATOMIC))
+		return 0;
+	priv->reg[1] = d;
+	return d & 0xf;
+}
+
+static unsigned char parport_uss720_read_status(struct parport *pp)
+{
+	unsigned char ret;
+
+	if (get_1284_register(pp, 1, &ret, GFP_ATOMIC))
+		return 0;
+	return ret & 0xf8;
+}
+
+static void parport_uss720_disable_irq(struct parport *pp)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	unsigned char d;
+
+	d = priv->reg[1] & ~0x10;
+	if (set_1284_register(pp, 2, d, GFP_KERNEL))
+		return;
+	priv->reg[1] = d;
+}
+
+static void parport_uss720_enable_irq(struct parport *pp)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	unsigned char d;
+
+	d = priv->reg[1] | 0x10;
+	if (set_1284_register(pp, 2, d, GFP_KERNEL))
+		return;
+	priv->reg[1] = d;
+}
+
+static void parport_uss720_data_forward (struct parport *pp)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	unsigned char d;
+
+	d = priv->reg[1] & ~0x20;
+	if (set_1284_register(pp, 2, d, GFP_KERNEL))
+		return;
+	priv->reg[1] = d;
+}
+
+static void parport_uss720_data_reverse (struct parport *pp)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	unsigned char d;
+
+	d = priv->reg[1] | 0x20;
+	if (set_1284_register(pp, 2, d, GFP_KERNEL))
+		return;
+	priv->reg[1] = d;
+}
+
+static void parport_uss720_init_state(struct pardevice *dev, struct parport_state *s)
+{
+	s->u.pc.ctr = 0xc | (dev->irq_func ? 0x10 : 0x0);
+	s->u.pc.ecr = 0x24;
+}
+
+static void parport_uss720_save_state(struct parport *pp, struct parport_state *s)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+
+#if 0
+	if (get_1284_register(pp, 2, NULL, GFP_ATOMIC))
+		return;
+#endif
+	s->u.pc.ctr = priv->reg[1];
+	s->u.pc.ecr = priv->reg[2];
+}
+
+static void parport_uss720_restore_state(struct parport *pp, struct parport_state *s)
+{
+	struct parport_uss720_private *priv = pp->private_data;
+
+	set_1284_register(pp, 2, s->u.pc.ctr, GFP_ATOMIC);
+	set_1284_register(pp, 6, s->u.pc.ecr, GFP_ATOMIC);
+	get_1284_register(pp, 2, NULL, GFP_ATOMIC);
+	priv->reg[1] = s->u.pc.ctr;
+	priv->reg[2] = s->u.pc.ecr;
+}
+
+static size_t parport_uss720_epp_read_data(struct parport *pp, void *buf, size_t length, int flags)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	size_t got = 0;
+
+	if (change_mode(pp, ECR_EPP))
+		return 0;
+	for (; got < length; got++) {
+		if (get_1284_register(pp, 4, (char *)buf, GFP_KERNEL))
+			break;
+		buf++;
+		if (priv->reg[0] & 0x01) {
+			clear_epp_timeout(pp);
+			break;
+		}
+	}
+	change_mode(pp, ECR_PS2);
+	return got;
+}
+
+static size_t parport_uss720_epp_write_data(struct parport *pp, const void *buf, size_t length, int flags)
+{
+#if 0
+	struct parport_uss720_private *priv = pp->private_data;	
+	size_t written = 0;
+
+	if (change_mode(pp, ECR_EPP))
+		return 0;
+	for (; written < length; written++) {
+		if (set_1284_register(pp, 4, (char *)buf, GFP_KERNEL))
+			break;
+		((char*)buf)++;
+		if (get_1284_register(pp, 1, NULL, GFP_KERNEL))
+			break;
+		if (priv->reg[0] & 0x01) {
+			clear_epp_timeout(pp);
+			break;
+		}
+	}
+	change_mode(pp, ECR_PS2);
+	return written;
+#else
+	struct parport_uss720_private *priv = pp->private_data;
+	struct usb_device *usbdev = priv->usbdev;
+	int rlen = 0;
+	int i;
+
+	if (!usbdev)
+		return 0;
+	if (change_mode(pp, ECR_EPP))
+		return 0;
+	i = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 1), (void *)buf, length, &rlen, 20000);
+	if (i)
+		printk(KERN_ERR "uss720: sendbulk ep 1 buf %p len %zu rlen %u\n", buf, length, rlen);
+	change_mode(pp, ECR_PS2);
+	return rlen;
+#endif
+}
+
+static size_t parport_uss720_epp_read_addr(struct parport *pp, void *buf, size_t length, int flags)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	size_t got = 0;
+
+	if (change_mode(pp, ECR_EPP))
+		return 0;
+	for (; got < length; got++) {
+		if (get_1284_register(pp, 3, (char *)buf, GFP_KERNEL))
+			break;
+		buf++;
+		if (priv->reg[0] & 0x01) {
+			clear_epp_timeout(pp);
+			break;
+		}
+	}
+	change_mode(pp, ECR_PS2);
+	return got;
+}
+
+static size_t parport_uss720_epp_write_addr(struct parport *pp, const void *buf, size_t length, int flags)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	size_t written = 0;
+
+	if (change_mode(pp, ECR_EPP))
+		return 0;
+	for (; written < length; written++) {
+		if (set_1284_register(pp, 3, *(char *)buf, GFP_KERNEL))
+			break;
+		buf++;
+		if (get_1284_register(pp, 1, NULL, GFP_KERNEL))
+			break;
+		if (priv->reg[0] & 0x01) {
+			clear_epp_timeout(pp);
+			break;
+		}
+	}
+	change_mode(pp, ECR_PS2);
+	return written;
+}
+
+static size_t parport_uss720_ecp_write_data(struct parport *pp, const void *buffer, size_t len, int flags)
+{
+	struct parport_uss720_private *priv = pp->private_data;
+	struct usb_device *usbdev = priv->usbdev;
+	int rlen = 0;
+	int i;
+
+	if (!usbdev)
+		return 0;
+	if (change_mode(pp, ECR_ECP))
+		return 0;
+	i = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 1), (void *)buffer, len, &rlen, 20000);
+	if (i)
+		printk(KERN_ERR "uss720: sendbulk ep 1 buf %p len %zu rlen %u\n", buffer, len, rlen);
+	change_mode(pp, ECR_PS2);
+	return rlen;
+}
+
+static size_t parport_uss720_ecp_read_data(struct parport *pp, void *buffer, size_t len, int flags)
+{
+	struct parport_uss720_private *priv = pp->private_data;
+	struct usb_device *usbdev = priv->usbdev;
+	int rlen = 0;
+	int i;
+
+	if (!usbdev)
+		return 0;
+	if (change_mode(pp, ECR_ECP))
+		return 0;
+	i = usb_bulk_msg(usbdev, usb_rcvbulkpipe(usbdev, 2), buffer, len, &rlen, 20000);
+	if (i)
+		printk(KERN_ERR "uss720: recvbulk ep 2 buf %p len %zu rlen %u\n", buffer, len, rlen);
+	change_mode(pp, ECR_PS2);
+	return rlen;
+}
+
+static size_t parport_uss720_ecp_write_addr(struct parport *pp, const void *buffer, size_t len, int flags)
+{
+	size_t written = 0;
+
+	if (change_mode(pp, ECR_ECP))
+		return 0;
+	for (; written < len; written++) {
+		if (set_1284_register(pp, 5, *(char *)buffer, GFP_KERNEL))
+			break;
+		buffer++;
+	}
+	change_mode(pp, ECR_PS2);
+	return written;
+}
+
+static size_t parport_uss720_write_compat(struct parport *pp, const void *buffer, size_t len, int flags)
+{
+	struct parport_uss720_private *priv = pp->private_data;
+	struct usb_device *usbdev = priv->usbdev;
+	int rlen = 0;
+	int i;
+
+	if (!usbdev)
+		return 0;
+	if (change_mode(pp, ECR_PPF))
+		return 0;
+	i = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 1), (void *)buffer, len, &rlen, 20000);
+	if (i)
+		printk(KERN_ERR "uss720: sendbulk ep 1 buf %p len %zu rlen %u\n", buffer, len, rlen);
+	change_mode(pp, ECR_PS2);
+	return rlen;
+}
+
+/* --------------------------------------------------------------------- */
+
+static struct parport_operations parport_uss720_ops = 
+{
+	.owner =		THIS_MODULE,
+	.write_data =		parport_uss720_write_data,
+	.read_data =		parport_uss720_read_data,
+
+	.write_control =	parport_uss720_write_control,
+	.read_control =		parport_uss720_read_control,
+	.frob_control =		parport_uss720_frob_control,
+
+	.read_status =		parport_uss720_read_status,
+
+	.enable_irq =		parport_uss720_enable_irq,
+	.disable_irq =		parport_uss720_disable_irq,
+
+	.data_forward =		parport_uss720_data_forward,
+	.data_reverse =		parport_uss720_data_reverse,
+
+	.init_state =		parport_uss720_init_state,
+	.save_state =		parport_uss720_save_state,
+	.restore_state =	parport_uss720_restore_state,
+
+	.epp_write_data =	parport_uss720_epp_write_data,
+	.epp_read_data =	parport_uss720_epp_read_data,
+	.epp_write_addr =	parport_uss720_epp_write_addr,
+	.epp_read_addr =	parport_uss720_epp_read_addr,
+
+	.ecp_write_data =	parport_uss720_ecp_write_data,
+	.ecp_read_data =	parport_uss720_ecp_read_data,
+	.ecp_write_addr =	parport_uss720_ecp_write_addr,
+
+	.compat_write_data =	parport_uss720_write_compat,
+	.nibble_read_data =	parport_ieee1284_read_nibble,
+	.byte_read_data =	parport_ieee1284_read_byte,
+};
+
+/* --------------------------------------------------------------------- */
+
+static int uss720_probe(struct usb_interface *intf,
+			const struct usb_device_id *id)
+{
+	struct usb_device *usbdev = usb_get_dev(interface_to_usbdev(intf));
+	struct usb_host_interface *interface;
+	struct usb_endpoint_descriptor *epd;
+	struct parport_uss720_private *priv;
+	struct parport *pp;
+	unsigned char reg;
+	int ret = -ENODEV;
+
+	dev_dbg(&intf->dev, "probe: vendor id 0x%x, device id 0x%x\n",
+		le16_to_cpu(usbdev->descriptor.idVendor),
+		le16_to_cpu(usbdev->descriptor.idProduct));
+
+	/* our known interfaces have 3 alternate settings */
+	if (intf->num_altsetting != 3)
+		goto bail_out_early;
+
+	ret = usb_set_interface(usbdev, intf->altsetting->desc.bInterfaceNumber, 2);
+	dev_dbg(&intf->dev, "set interface result %d\n", ret);
+
+	interface = intf->cur_altsetting;
+
+	if (interface->desc.bNumEndpoints < 2)
+		goto bail_out_early;
+
+	/*
+	 * Allocate parport interface 
+	 */
+	ret = -ENOMEM;
+	priv = kzalloc_obj(struct parport_uss720_private);
+	if (!priv)
+		goto bail_out_early;
+
+	priv->pp = NULL;
+	priv->usbdev = usbdev;
+	kref_init(&priv->ref_count);
+	spin_lock_init(&priv->asynclock);
+	INIT_LIST_HEAD(&priv->asynclist);
+	pp = parport_register_port(0, PARPORT_IRQ_NONE, PARPORT_DMA_NONE, &parport_uss720_ops);
+	if (!pp) {
+		printk(KERN_WARNING "uss720: could not register parport\n");
+		goto probe_abort;
+	}
+
+	priv->pp = pp;
+	pp->private_data = priv;
+	pp->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_TRISTATE | PARPORT_MODE_EPP | PARPORT_MODE_COMPAT;
+	if (interface->desc.bNumEndpoints >= 3)
+		pp->modes |= PARPORT_MODE_ECP;
+	pp->dev = &usbdev->dev;
+
+	/* set the USS720 control register to manual mode, no ECP compression, enable all ints */
+	set_1284_register(pp, 7, 0x00, GFP_KERNEL);
+	set_1284_register(pp, 6, 0x30, GFP_KERNEL);  /* PS/2 mode */
+	set_1284_register(pp, 2, 0x0c, GFP_KERNEL);
+
+	/* The Belkin F5U002 Rev 2 P80453-B USB parallel port adapter shares the
+	 * device ID 050d:0002 with some other device that works with this
+	 * driver, but it itself does not. Detect and handle the bad cable
+	 * here. */
+	ret = get_1284_register(pp, 0, &reg, GFP_KERNEL);
+	dev_dbg(&intf->dev, "reg: %7ph\n", priv->reg);
+	if (ret < 0) {
+		priv->pp = NULL;
+		parport_del_port(pp);
+		goto probe_abort;
+	}
+
+	ret = usb_find_last_int_in_endpoint(interface, &epd);
+	if (!ret) {
+		dev_dbg(&intf->dev, "epaddr %d interval %d\n",
+				epd->bEndpointAddress, epd->bInterval);
+	}
+	parport_announce_port(pp);
+
+	usb_set_intfdata(intf, pp);
+	return 0;
+
+probe_abort:
+	kill_all_async_requests_priv(priv);
+	kref_put(&priv->ref_count, destroy_priv);
+	return -ENODEV;
+
+bail_out_early:
+	usb_put_dev(usbdev);
+	return ret;
+}
+
+static void uss720_disconnect(struct usb_interface *intf)
+{
+	struct parport *pp = usb_get_intfdata(intf);
+	struct parport_uss720_private *priv;
+
+	dev_dbg(&intf->dev, "disconnect\n");
+	usb_set_intfdata(intf, NULL);
+	if (pp) {
+		priv = pp->private_data;
+		priv->pp = NULL;
+		dev_dbg(&intf->dev, "parport_remove_port\n");
+		parport_remove_port(pp);
+		parport_put_port(pp);
+		kill_all_async_requests_priv(priv);
+		kref_put(&priv->ref_count, destroy_priv);
+	}
+	dev_dbg(&intf->dev, "disconnect done\n");
+}
+
+/* table of cables that work through this driver */
+static const struct usb_device_id uss720_table[] = {
+	{ USB_DEVICE(0x047e, 0x1001) }, /* Infowave 901-0030 */
+	{ USB_DEVICE(0x04b8, 0x0002) }, /* Epson CAEUL0002 ISD-103 */
+	{ USB_DEVICE(0x04b8, 0x0003) }, /* Epson ISD-101 */
+	{ USB_DEVICE(0x050d, 0x0002) },
+	{ USB_DEVICE(0x050d, 0x1202) }, /* Belkin F5U120-PC */
+	{ USB_DEVICE(0x0557, 0x2001) },
+	{ USB_DEVICE(0x05ab, 0x0002) }, /* Belkin F5U002 ISD-101 */
+	{ USB_DEVICE(0x05ab, 0x1001) }, /* Belkin F5U002 P80453-A */
+	{ USB_DEVICE(0x06c6, 0x0100) }, /* Infowave ISD-103 */
+	{ USB_DEVICE(0x0729, 0x1284) },
+	{ USB_DEVICE(0x1293, 0x0002) },
+	{ }						/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE (usb, uss720_table);
+
+
+static struct usb_driver uss720_driver = {
+	.name =		"uss720",
+	.probe =	uss720_probe,
+	.disconnect =	uss720_disconnect,
+	.id_table =	uss720_table,
+};
+
+/* --------------------------------------------------------------------- */
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+static int __init uss720_init(void)
+{
+	int retval;
+	retval = usb_register(&uss720_driver);
+	if (retval)
+		goto out;
+
+	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_DESC "\n");
+	printk(KERN_INFO KBUILD_MODNAME ": NOTE: this is a special purpose "
+	       "driver to allow nonstandard\n");
+	printk(KERN_INFO KBUILD_MODNAME ": protocols (eg. bitbang) over "
+	       "USS720 usb to parallel cables\n");
+	printk(KERN_INFO KBUILD_MODNAME ": If you just want to connect to a "
+	       "printer, use usblp instead\n");
+out:
+	return retval;
+}
+
+static void __exit uss720_cleanup(void)
+{
+	usb_deregister(&uss720_driver);
+}
+
+module_init(uss720_init);
+module_exit(uss720_cleanup);
+
+/* --------------------------------------------------------------------- */