Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 720 insertions, 0 deletions

diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
new file mode 100644
index 000000000..6fd15cd9e
--- /dev/null
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -0,0 +1,720 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * USB Keyspan PDA / Xircom / Entrega Converter driver
+ *
+ * Copyright (C) 1999 - 2001 Greg Kroah-Hartman	<greg@kroah.com>
+ * Copyright (C) 1999, 2000 Brian Warner	<warner@lothar.com>
+ * Copyright (C) 2000 Al Borchers		<borchers@steinerpoint.com>
+ * Copyright (C) 2020 Johan Hovold <johan@kernel.org>
+ *
+ * See Documentation/usb/usb-serial.rst for more information on using this
+ * driver
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <linux/uaccess.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+#include <linux/usb/ezusb.h>
+
+#define DRIVER_AUTHOR "Brian Warner <warner@lothar.com>, Johan Hovold <johan@kernel.org>"
+#define DRIVER_DESC "USB Keyspan PDA Converter driver"
+
+#define KEYSPAN_TX_THRESHOLD	128
+
+struct keyspan_pda_private {
+	int			tx_room;
+	struct work_struct	unthrottle_work;
+	struct usb_serial	*serial;
+	struct usb_serial_port	*port;
+};
+
+static int keyspan_pda_write_start(struct usb_serial_port *port);
+
+#define KEYSPAN_VENDOR_ID		0x06cd
+#define KEYSPAN_PDA_FAKE_ID		0x0103
+#define KEYSPAN_PDA_ID			0x0104 /* no clue */
+
+/* For Xircom PGSDB9 and older Entrega version of the same device */
+#define XIRCOM_VENDOR_ID		0x085a
+#define XIRCOM_FAKE_ID			0x8027
+#define XIRCOM_FAKE_ID_2		0x8025 /* "PGMFHUB" serial */
+#define ENTREGA_VENDOR_ID		0x1645
+#define ENTREGA_FAKE_ID			0x8093
+
+static const struct usb_device_id id_table_combined[] = {
+	{ USB_DEVICE(KEYSPAN_VENDOR_ID, KEYSPAN_PDA_FAKE_ID) },
+	{ USB_DEVICE(XIRCOM_VENDOR_ID, XIRCOM_FAKE_ID) },
+	{ USB_DEVICE(XIRCOM_VENDOR_ID, XIRCOM_FAKE_ID_2) },
+	{ USB_DEVICE(ENTREGA_VENDOR_ID, ENTREGA_FAKE_ID) },
+	{ USB_DEVICE(KEYSPAN_VENDOR_ID, KEYSPAN_PDA_ID) },
+	{ }						/* Terminating entry */
+};
+MODULE_DEVICE_TABLE(usb, id_table_combined);
+
+static const struct usb_device_id id_table_std[] = {
+	{ USB_DEVICE(KEYSPAN_VENDOR_ID, KEYSPAN_PDA_ID) },
+	{ }						/* Terminating entry */
+};
+
+static const struct usb_device_id id_table_fake[] = {
+	{ USB_DEVICE(KEYSPAN_VENDOR_ID, KEYSPAN_PDA_FAKE_ID) },
+	{ USB_DEVICE(XIRCOM_VENDOR_ID, XIRCOM_FAKE_ID) },
+	{ USB_DEVICE(XIRCOM_VENDOR_ID, XIRCOM_FAKE_ID_2) },
+	{ USB_DEVICE(ENTREGA_VENDOR_ID, ENTREGA_FAKE_ID) },
+	{ }						/* Terminating entry */
+};
+
+static int keyspan_pda_get_write_room(struct keyspan_pda_private *priv)
+{
+	struct usb_serial_port *port = priv->port;
+	struct usb_serial *serial = port->serial;
+	u8 room;
+	int rc;
+
+	rc = usb_control_msg_recv(serial->dev,
+				  0,
+				  6, /* write_room */
+				  USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_IN,
+				  0, /* value: 0 means "remaining room" */
+				  0, /* index */
+				  &room,
+				  1,
+				  2000,
+				  GFP_KERNEL);
+	if (rc) {
+		dev_dbg(&port->dev, "roomquery failed: %d\n", rc);
+		return rc;
+	}
+
+	dev_dbg(&port->dev, "roomquery says %d\n", room);
+
+	return room;
+}
+
+static void keyspan_pda_request_unthrottle(struct work_struct *work)
+{
+	struct keyspan_pda_private *priv =
+		container_of(work, struct keyspan_pda_private, unthrottle_work);
+	struct usb_serial_port *port = priv->port;
+	struct usb_serial *serial = port->serial;
+	unsigned long flags;
+	int result;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	/*
+	 * Ask the device to tell us when the tx buffer becomes
+	 * sufficiently empty.
+	 */
+	result = usb_control_msg(serial->dev,
+				 usb_sndctrlpipe(serial->dev, 0),
+				 7, /* request_unthrottle */
+				 USB_TYPE_VENDOR | USB_RECIP_INTERFACE
+				 | USB_DIR_OUT,
+				 KEYSPAN_TX_THRESHOLD,
+				 0, /* index */
+				 NULL,
+				 0,
+				 2000);
+	if (result < 0)
+		dev_dbg(&serial->dev->dev, "%s - error %d from usb_control_msg\n",
+			__func__, result);
+	/*
+	 * Need to check available space after requesting notification in case
+	 * buffer is already empty so that no notification is sent.
+	 */
+	result = keyspan_pda_get_write_room(priv);
+	if (result > KEYSPAN_TX_THRESHOLD) {
+		spin_lock_irqsave(&port->lock, flags);
+		priv->tx_room = max(priv->tx_room, result);
+		spin_unlock_irqrestore(&port->lock, flags);
+
+		usb_serial_port_softint(port);
+	}
+}
+
+static void keyspan_pda_rx_interrupt(struct urb *urb)
+{
+	struct usb_serial_port *port = urb->context;
+	unsigned char *data = urb->transfer_buffer;
+	unsigned int len = urb->actual_length;
+	int retval;
+	int status = urb->status;
+	struct keyspan_pda_private *priv;
+	unsigned long flags;
+
+	priv = usb_get_serial_port_data(port);
+
+	switch (status) {
+	case 0:
+		/* success */
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		/* this urb is terminated, clean up */
+		dev_dbg(&urb->dev->dev, "%s - urb shutting down with status: %d\n", __func__, status);
+		return;
+	default:
+		dev_dbg(&urb->dev->dev, "%s - nonzero urb status received: %d\n", __func__, status);
+		goto exit;
+	}
+
+	if (len < 1) {
+		dev_warn(&port->dev, "short message received\n");
+		goto exit;
+	}
+
+	/* see if the message is data or a status interrupt */
+	switch (data[0]) {
+	case 0:
+		 /* rest of message is rx data */
+		if (len < 2)
+			break;
+		tty_insert_flip_string(&port->port, data + 1, len - 1);
+		tty_flip_buffer_push(&port->port);
+		break;
+	case 1:
+		/* status interrupt */
+		if (len < 2) {
+			dev_warn(&port->dev, "short interrupt message received\n");
+			break;
+		}
+		dev_dbg(&port->dev, "rx int, d1=%d\n", data[1]);
+		switch (data[1]) {
+		case 1: /* modemline change */
+			break;
+		case 2: /* tx unthrottle interrupt */
+			spin_lock_irqsave(&port->lock, flags);
+			priv->tx_room = max(priv->tx_room, KEYSPAN_TX_THRESHOLD);
+			spin_unlock_irqrestore(&port->lock, flags);
+
+			keyspan_pda_write_start(port);
+
+			usb_serial_port_softint(port);
+			break;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+
+exit:
+	retval = usb_submit_urb(urb, GFP_ATOMIC);
+	if (retval)
+		dev_err(&port->dev,
+			"%s - usb_submit_urb failed with result %d\n",
+			__func__, retval);
+}
+
+static void keyspan_pda_rx_throttle(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	/*
+	 * Stop receiving characters. We just turn off the URB request, and
+	 * let chars pile up in the device. If we're doing hardware
+	 * flowcontrol, the device will signal the other end when its buffer
+	 * fills up. If we're doing XON/XOFF, this would be a good time to
+	 * send an XOFF, although it might make sense to foist that off upon
+	 * the device too.
+	 */
+	usb_kill_urb(port->interrupt_in_urb);
+}
+
+static void keyspan_pda_rx_unthrottle(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+
+	/* just restart the receive interrupt URB */
+	if (usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL))
+		dev_dbg(&port->dev, "usb_submit_urb(read urb) failed\n");
+}
+
+static speed_t keyspan_pda_setbaud(struct usb_serial *serial, speed_t baud)
+{
+	int rc;
+	int bindex;
+
+	switch (baud) {
+	case 110:
+		bindex = 0;
+		break;
+	case 300:
+		bindex = 1;
+		break;
+	case 1200:
+		bindex = 2;
+		break;
+	case 2400:
+		bindex = 3;
+		break;
+	case 4800:
+		bindex = 4;
+		break;
+	case 9600:
+		bindex = 5;
+		break;
+	case 19200:
+		bindex = 6;
+		break;
+	case 38400:
+		bindex = 7;
+		break;
+	case 57600:
+		bindex = 8;
+		break;
+	case 115200:
+		bindex = 9;
+		break;
+	default:
+		bindex = 5;	/* Default to 9600 */
+		baud = 9600;
+	}
+
+	rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+			     0, /* set baud */
+			     USB_TYPE_VENDOR
+			     | USB_RECIP_INTERFACE
+			     | USB_DIR_OUT, /* type */
+			     bindex, /* value */
+			     0, /* index */
+			     NULL, /* &data */
+			     0, /* size */
+			     2000); /* timeout */
+	if (rc < 0)
+		return 0;
+
+	return baud;
+}
+
+static void keyspan_pda_break_ctl(struct tty_struct *tty, int break_state)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct usb_serial *serial = port->serial;
+	int value;
+	int result;
+
+	if (break_state == -1)
+		value = 1; /* start break */
+	else
+		value = 0; /* clear break */
+
+	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+			4, /* set break */
+			USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
+			value, 0, NULL, 0, 2000);
+	if (result < 0)
+		dev_dbg(&port->dev, "%s - error %d from usb_control_msg\n",
+			__func__, result);
+}
+
+static void keyspan_pda_set_termios(struct tty_struct *tty,
+				    struct usb_serial_port *port,
+				    const struct ktermios *old_termios)
+{
+	struct usb_serial *serial = port->serial;
+	speed_t speed;
+
+	/*
+	 * cflag specifies lots of stuff: number of stop bits, parity, number
+	 * of data bits, baud. What can the device actually handle?:
+	 * CSTOPB (1 stop bit or 2)
+	 * PARENB (parity)
+	 * CSIZE (5bit .. 8bit)
+	 * There is minimal hw support for parity (a PSW bit seems to hold the
+	 * parity of whatever is in the accumulator). The UART either deals
+	 * with 10 bits (start, 8 data, stop) or 11 bits (start, 8 data,
+	 * 1 special, stop). So, with firmware changes, we could do:
+	 * 8N1: 10 bit
+	 * 8N2: 11 bit, extra bit always (mark?)
+	 * 8[EOMS]1: 11 bit, extra bit is parity
+	 * 7[EOMS]1: 10 bit, b0/b7 is parity
+	 * 7[EOMS]2: 11 bit, b0/b7 is parity, extra bit always (mark?)
+	 *
+	 * HW flow control is dictated by the tty->termios.c_cflags & CRTSCTS
+	 * bit.
+	 *
+	 * For now, just do baud.
+	 */
+	speed = tty_get_baud_rate(tty);
+	speed = keyspan_pda_setbaud(serial, speed);
+
+	if (speed == 0) {
+		dev_dbg(&port->dev, "can't handle requested baud rate\n");
+		/* It hasn't changed so.. */
+		speed = tty_termios_baud_rate(old_termios);
+	}
+	/*
+	 * Only speed can change so copy the old h/w parameters then encode
+	 * the new speed.
+	 */
+	tty_termios_copy_hw(&tty->termios, old_termios);
+	tty_encode_baud_rate(tty, speed, speed);
+}
+
+/*
+ * Modem control pins: DTR and RTS are outputs and can be controlled.
+ * DCD, RI, DSR, CTS are inputs and can be read. All outputs can also be
+ * read. The byte passed is: DTR(b7) DCD RI DSR CTS RTS(b2) unused unused.
+ */
+static int keyspan_pda_get_modem_info(struct usb_serial *serial,
+				      unsigned char *value)
+{
+	int rc;
+	u8 data;
+
+	rc = usb_control_msg_recv(serial->dev, 0,
+				  3, /* get pins */
+				  USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_IN,
+				  0,
+				  0,
+				  &data,
+				  1,
+				  2000,
+				  GFP_KERNEL);
+	if (rc == 0)
+		*value = data;
+
+	return rc;
+}
+
+static int keyspan_pda_set_modem_info(struct usb_serial *serial,
+				      unsigned char value)
+{
+	int rc;
+	rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+			     3, /* set pins */
+			     USB_TYPE_VENDOR|USB_RECIP_INTERFACE|USB_DIR_OUT,
+			     value, 0, NULL, 0, 2000);
+	return rc;
+}
+
+static int keyspan_pda_tiocmget(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct usb_serial *serial = port->serial;
+	int rc;
+	unsigned char status;
+	int value;
+
+	rc = keyspan_pda_get_modem_info(serial, &status);
+	if (rc < 0)
+		return rc;
+
+	value = ((status & BIT(7)) ? TIOCM_DTR : 0) |
+		((status & BIT(6)) ? TIOCM_CAR : 0) |
+		((status & BIT(5)) ? TIOCM_RNG : 0) |
+		((status & BIT(4)) ? TIOCM_DSR : 0) |
+		((status & BIT(3)) ? TIOCM_CTS : 0) |
+		((status & BIT(2)) ? TIOCM_RTS : 0);
+
+	return value;
+}
+
+static int keyspan_pda_tiocmset(struct tty_struct *tty,
+				unsigned int set, unsigned int clear)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct usb_serial *serial = port->serial;
+	int rc;
+	unsigned char status;
+
+	rc = keyspan_pda_get_modem_info(serial, &status);
+	if (rc < 0)
+		return rc;
+
+	if (set & TIOCM_RTS)
+		status |= BIT(2);
+	if (set & TIOCM_DTR)
+		status |= BIT(7);
+
+	if (clear & TIOCM_RTS)
+		status &= ~BIT(2);
+	if (clear & TIOCM_DTR)
+		status &= ~BIT(7);
+	rc = keyspan_pda_set_modem_info(serial, status);
+	return rc;
+}
+
+static int keyspan_pda_write_start(struct usb_serial_port *port)
+{
+	struct keyspan_pda_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	struct urb *urb;
+	int count;
+	int room;
+	int rc;
+
+	/*
+	 * Guess how much room is left in the device's ring buffer. If our
+	 * write will result in no room left, ask the device to give us an
+	 * interrupt when the room available rises above a threshold but also
+	 * query how much room is currently available (in case our guess was
+	 * too conservative and the buffer is already empty when the
+	 * unthrottle work is scheduled).
+	 */
+
+	/*
+	 * We might block because of:
+	 * the TX urb is in-flight (wait until it completes)
+	 * the device is full (wait until it says there is room)
+	 */
+	spin_lock_irqsave(&port->lock, flags);
+
+	room = priv->tx_room;
+	count = kfifo_len(&port->write_fifo);
+
+	if (!test_bit(0, &port->write_urbs_free) || count == 0 || room == 0) {
+		spin_unlock_irqrestore(&port->lock, flags);
+		return 0;
+	}
+	__clear_bit(0, &port->write_urbs_free);
+
+	if (count > room)
+		count = room;
+	if (count > port->bulk_out_size)
+		count = port->bulk_out_size;
+
+	urb = port->write_urb;
+	count = kfifo_out(&port->write_fifo, urb->transfer_buffer, count);
+	urb->transfer_buffer_length = count;
+
+	port->tx_bytes += count;
+	priv->tx_room -= count;
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	dev_dbg(&port->dev, "%s - count = %d, txroom = %d\n", __func__, count, room);
+
+	rc = usb_submit_urb(urb, GFP_ATOMIC);
+	if (rc) {
+		dev_dbg(&port->dev, "usb_submit_urb(write bulk) failed\n");
+
+		spin_lock_irqsave(&port->lock, flags);
+		port->tx_bytes -= count;
+		priv->tx_room = max(priv->tx_room, room + count);
+		__set_bit(0, &port->write_urbs_free);
+		spin_unlock_irqrestore(&port->lock, flags);
+
+		return rc;
+	}
+
+	if (count == room)
+		schedule_work(&priv->unthrottle_work);
+
+	return count;
+}
+
+static void keyspan_pda_write_bulk_callback(struct urb *urb)
+{
+	struct usb_serial_port *port = urb->context;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	port->tx_bytes -= urb->transfer_buffer_length;
+	__set_bit(0, &port->write_urbs_free);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	keyspan_pda_write_start(port);
+
+	usb_serial_port_softint(port);
+}
+
+static int keyspan_pda_write(struct tty_struct *tty, struct usb_serial_port *port,
+		const unsigned char *buf, int count)
+{
+	int rc;
+
+	dev_dbg(&port->dev, "%s - count = %d\n", __func__, count);
+
+	if (!count)
+		return 0;
+
+	count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
+
+	rc = keyspan_pda_write_start(port);
+	if (rc)
+		return rc;
+
+	return count;
+}
+
+static void keyspan_pda_dtr_rts(struct usb_serial_port *port, int on)
+{
+	struct usb_serial *serial = port->serial;
+
+	if (on)
+		keyspan_pda_set_modem_info(serial, BIT(7) | BIT(2));
+	else
+		keyspan_pda_set_modem_info(serial, 0);
+}
+
+
+static int keyspan_pda_open(struct tty_struct *tty,
+					struct usb_serial_port *port)
+{
+	struct keyspan_pda_private *priv = usb_get_serial_port_data(port);
+	int rc;
+
+	/* find out how much room is in the Tx ring */
+	rc = keyspan_pda_get_write_room(priv);
+	if (rc < 0)
+		return rc;
+
+	spin_lock_irq(&port->lock);
+	priv->tx_room = rc;
+	spin_unlock_irq(&port->lock);
+
+	rc = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
+	if (rc) {
+		dev_dbg(&port->dev, "%s - usb_submit_urb(read int) failed\n", __func__);
+		return rc;
+	}
+
+	return 0;
+}
+
+static void keyspan_pda_close(struct usb_serial_port *port)
+{
+	struct keyspan_pda_private *priv = usb_get_serial_port_data(port);
+
+	/*
+	 * Stop the interrupt URB first as its completion handler may submit
+	 * the write URB.
+	 */
+	usb_kill_urb(port->interrupt_in_urb);
+	usb_kill_urb(port->write_urb);
+
+	cancel_work_sync(&priv->unthrottle_work);
+
+	spin_lock_irq(&port->lock);
+	kfifo_reset(&port->write_fifo);
+	spin_unlock_irq(&port->lock);
+}
+
+/* download the firmware to a "fake" device (pre-renumeration) */
+static int keyspan_pda_fake_startup(struct usb_serial *serial)
+{
+	unsigned int vid = le16_to_cpu(serial->dev->descriptor.idVendor);
+	const char *fw_name;
+
+	/* download the firmware here ... */
+	ezusb_fx1_set_reset(serial->dev, 1);
+
+	switch (vid) {
+	case KEYSPAN_VENDOR_ID:
+		fw_name = "keyspan_pda/keyspan_pda.fw";
+		break;
+	case XIRCOM_VENDOR_ID:
+	case ENTREGA_VENDOR_ID:
+		fw_name = "keyspan_pda/xircom_pgs.fw";
+		break;
+	default:
+		dev_err(&serial->dev->dev, "%s: unknown vendor, aborting.\n",
+			__func__);
+		return -ENODEV;
+	}
+
+	if (ezusb_fx1_ihex_firmware_download(serial->dev, fw_name) < 0) {
+		dev_err(&serial->dev->dev, "failed to load firmware \"%s\"\n",
+			fw_name);
+		return -ENOENT;
+	}
+
+	/*
+	 * After downloading firmware renumeration will occur in a moment and
+	 * the new device will bind to the real driver.
+	 */
+
+	/* We want this device to fail to have a driver assigned to it. */
+	return 1;
+}
+
+MODULE_FIRMWARE("keyspan_pda/keyspan_pda.fw");
+MODULE_FIRMWARE("keyspan_pda/xircom_pgs.fw");
+
+static int keyspan_pda_port_probe(struct usb_serial_port *port)
+{
+
+	struct keyspan_pda_private *priv;
+
+	priv = kmalloc(sizeof(struct keyspan_pda_private), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	INIT_WORK(&priv->unthrottle_work, keyspan_pda_request_unthrottle);
+	priv->port = port;
+
+	usb_set_serial_port_data(port, priv);
+
+	return 0;
+}
+
+static void keyspan_pda_port_remove(struct usb_serial_port *port)
+{
+	struct keyspan_pda_private *priv;
+
+	priv = usb_get_serial_port_data(port);
+	kfree(priv);
+}
+
+static struct usb_serial_driver keyspan_pda_fake_device = {
+	.driver = {
+		.owner =	THIS_MODULE,
+		.name =		"keyspan_pda_pre",
+	},
+	.description =		"Keyspan PDA - (prerenumeration)",
+	.id_table =		id_table_fake,
+	.num_ports =		1,
+	.attach =		keyspan_pda_fake_startup,
+};
+
+static struct usb_serial_driver keyspan_pda_device = {
+	.driver = {
+		.owner =	THIS_MODULE,
+		.name =		"keyspan_pda",
+	},
+	.description =		"Keyspan PDA",
+	.id_table =		id_table_std,
+	.num_ports =		1,
+	.num_bulk_out =		1,
+	.num_interrupt_in =	1,
+	.dtr_rts =		keyspan_pda_dtr_rts,
+	.open =			keyspan_pda_open,
+	.close =		keyspan_pda_close,
+	.write =		keyspan_pda_write,
+	.write_bulk_callback =	keyspan_pda_write_bulk_callback,
+	.read_int_callback =	keyspan_pda_rx_interrupt,
+	.throttle =		keyspan_pda_rx_throttle,
+	.unthrottle =		keyspan_pda_rx_unthrottle,
+	.set_termios =		keyspan_pda_set_termios,
+	.break_ctl =		keyspan_pda_break_ctl,
+	.tiocmget =		keyspan_pda_tiocmget,
+	.tiocmset =		keyspan_pda_tiocmset,
+	.port_probe =		keyspan_pda_port_probe,
+	.port_remove =		keyspan_pda_port_remove,
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+	&keyspan_pda_device,
+	&keyspan_pda_fake_device,
+	NULL
+};
+
+module_usb_serial_driver(serial_drivers, id_table_combined);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");