Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 844 insertions, 0 deletions

diff --git a/drivers/usb/serial/oti6858.c b/drivers/usb/serial/oti6858.c
new file mode 100644
index 000000000..6365cfe54
--- /dev/null
+++ b/drivers/usb/serial/oti6858.c
@@ -0,0 +1,844 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Ours Technology Inc. OTi-6858 USB to serial adapter driver.
+ *
+ * Copyleft  (C) 2007 Kees Lemmens (adapted for kernel 2.6.20)
+ * Copyright (C) 2006 Tomasz Michal Lukaszewski (FIXME: add e-mail)
+ * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
+ * Copyright (C) 2003 IBM Corp.
+ *
+ * Many thanks to the authors of pl2303 driver: all functions in this file
+ * are heavily based on pl2303 code, buffering code is a 1-to-1 copy.
+ *
+ * Warning! You use this driver on your own risk! The only official
+ * description of this device I have is datasheet from manufacturer,
+ * and it doesn't contain almost any information needed to write a driver.
+ * Almost all knowlegde used while writing this driver was gathered by:
+ *  - analyzing traffic between device and the M$ Windows 2000 driver,
+ *  - trying different bit combinations and checking pin states
+ *    with a voltmeter,
+ *  - receiving malformed frames and producing buffer overflows
+ *    to learn how errors are reported,
+ * So, THIS CODE CAN DESTROY OTi-6858 AND ANY OTHER DEVICES, THAT ARE
+ * CONNECTED TO IT!
+ *
+ * See Documentation/usb/usb-serial.rst for more information on using this
+ * driver
+ *
+ * TODO:
+ *  - implement correct flushing for ioctls and oti6858_close()
+ *  - check how errors (rx overflow, parity error, framing error) are reported
+ *  - implement oti6858_break_ctl()
+ *  - implement more ioctls
+ *  - test/implement flow control
+ *  - allow setting custom baud rates
+ */
+
+#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/serial.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/spinlock.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+#include <linux/uaccess.h>
+#include <linux/kfifo.h>
+#include "oti6858.h"
+
+#define OTI6858_DESCRIPTION \
+	"Ours Technology Inc. OTi-6858 USB to serial adapter driver"
+#define OTI6858_AUTHOR "Tomasz Michal Lukaszewski <FIXME@FIXME>"
+
+static const struct usb_device_id id_table[] = {
+	{ USB_DEVICE(OTI6858_VENDOR_ID, OTI6858_PRODUCT_ID) },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(usb, id_table);
+
+/* requests */
+#define	OTI6858_REQ_GET_STATUS		(USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
+#define	OTI6858_REQ_T_GET_STATUS	0x01
+
+#define	OTI6858_REQ_SET_LINE		(USB_DIR_OUT | USB_TYPE_VENDOR | 0x00)
+#define	OTI6858_REQ_T_SET_LINE		0x00
+
+#define	OTI6858_REQ_CHECK_TXBUFF	(USB_DIR_IN | USB_TYPE_VENDOR | 0x01)
+#define	OTI6858_REQ_T_CHECK_TXBUFF	0x00
+
+/* format of the control packet */
+struct oti6858_control_pkt {
+	__le16	divisor;	/* baud rate = 96000000 / (16 * divisor), LE */
+#define OTI6858_MAX_BAUD_RATE	3000000
+	u8	frame_fmt;
+#define FMT_STOP_BITS_MASK	0xc0
+#define FMT_STOP_BITS_1		0x00
+#define FMT_STOP_BITS_2		0x40	/* 1.5 stop bits if FMT_DATA_BITS_5 */
+#define FMT_PARITY_MASK		0x38
+#define FMT_PARITY_NONE		0x00
+#define FMT_PARITY_ODD		0x08
+#define FMT_PARITY_EVEN		0x18
+#define FMT_PARITY_MARK		0x28
+#define FMT_PARITY_SPACE	0x38
+#define FMT_DATA_BITS_MASK	0x03
+#define FMT_DATA_BITS_5		0x00
+#define FMT_DATA_BITS_6		0x01
+#define FMT_DATA_BITS_7		0x02
+#define FMT_DATA_BITS_8		0x03
+	u8	something;	/* always equals 0x43 */
+	u8	control;	/* settings of flow control lines */
+#define CONTROL_MASK		0x0c
+#define CONTROL_DTR_HIGH	0x08
+#define CONTROL_RTS_HIGH	0x04
+	u8	tx_status;
+#define	TX_BUFFER_EMPTIED	0x09
+	u8	pin_state;
+#define PIN_MASK		0x3f
+#define PIN_MSR_MASK		0x1b
+#define PIN_RTS			0x20	/* output pin */
+#define PIN_CTS			0x10	/* input pin, active low */
+#define PIN_DSR			0x08	/* input pin, active low */
+#define PIN_DTR			0x04	/* output pin */
+#define PIN_RI			0x02	/* input pin, active low */
+#define PIN_DCD			0x01	/* input pin, active low */
+	u8	rx_bytes_avail;		/* number of bytes in rx buffer */;
+};
+
+#define OTI6858_CTRL_PKT_SIZE	sizeof(struct oti6858_control_pkt)
+#define OTI6858_CTRL_EQUALS_PENDING(a, priv) \
+	(((a)->divisor == (priv)->pending_setup.divisor) \
+	  && ((a)->control == (priv)->pending_setup.control) \
+	  && ((a)->frame_fmt == (priv)->pending_setup.frame_fmt))
+
+/* function prototypes */
+static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port);
+static void oti6858_close(struct usb_serial_port *port);
+static void oti6858_set_termios(struct tty_struct *tty,
+				struct usb_serial_port *port,
+				const struct ktermios *old_termios);
+static void oti6858_init_termios(struct tty_struct *tty);
+static void oti6858_read_int_callback(struct urb *urb);
+static void oti6858_read_bulk_callback(struct urb *urb);
+static void oti6858_write_bulk_callback(struct urb *urb);
+static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
+			const unsigned char *buf, int count);
+static unsigned int oti6858_write_room(struct tty_struct *tty);
+static unsigned int oti6858_chars_in_buffer(struct tty_struct *tty);
+static int oti6858_tiocmget(struct tty_struct *tty);
+static int oti6858_tiocmset(struct tty_struct *tty,
+				unsigned int set, unsigned int clear);
+static int oti6858_port_probe(struct usb_serial_port *port);
+static void oti6858_port_remove(struct usb_serial_port *port);
+
+/* device info */
+static struct usb_serial_driver oti6858_device = {
+	.driver = {
+		.owner =	THIS_MODULE,
+		.name =		"oti6858",
+	},
+	.id_table =		id_table,
+	.num_ports =		1,
+	.num_bulk_in =		1,
+	.num_bulk_out =		1,
+	.num_interrupt_in =	1,
+	.open =			oti6858_open,
+	.close =		oti6858_close,
+	.write =		oti6858_write,
+	.set_termios =		oti6858_set_termios,
+	.init_termios = 	oti6858_init_termios,
+	.tiocmget =		oti6858_tiocmget,
+	.tiocmset =		oti6858_tiocmset,
+	.tiocmiwait =		usb_serial_generic_tiocmiwait,
+	.read_bulk_callback =	oti6858_read_bulk_callback,
+	.read_int_callback =	oti6858_read_int_callback,
+	.write_bulk_callback =	oti6858_write_bulk_callback,
+	.write_room =		oti6858_write_room,
+	.chars_in_buffer =	oti6858_chars_in_buffer,
+	.port_probe =		oti6858_port_probe,
+	.port_remove =		oti6858_port_remove,
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+	&oti6858_device, NULL
+};
+
+struct oti6858_private {
+	spinlock_t lock;
+
+	struct oti6858_control_pkt status;
+
+	struct {
+		u8 read_urb_in_use;
+		u8 write_urb_in_use;
+	} flags;
+	struct delayed_work delayed_write_work;
+
+	struct {
+		__le16 divisor;
+		u8 frame_fmt;
+		u8 control;
+	} pending_setup;
+	u8 transient;
+	u8 setup_done;
+	struct delayed_work delayed_setup_work;
+
+	struct usb_serial_port *port;   /* USB port with which associated */
+};
+
+static void setup_line(struct work_struct *work)
+{
+	struct oti6858_private *priv = container_of(work,
+			struct oti6858_private, delayed_setup_work.work);
+	struct usb_serial_port *port = priv->port;
+	struct oti6858_control_pkt *new_setup;
+	unsigned long flags;
+	int result;
+
+	new_setup = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
+	if (!new_setup) {
+		/* we will try again */
+		schedule_delayed_work(&priv->delayed_setup_work,
+						msecs_to_jiffies(2));
+		return;
+	}
+
+	result = usb_control_msg(port->serial->dev,
+				usb_rcvctrlpipe(port->serial->dev, 0),
+				OTI6858_REQ_T_GET_STATUS,
+				OTI6858_REQ_GET_STATUS,
+				0, 0,
+				new_setup, OTI6858_CTRL_PKT_SIZE,
+				100);
+
+	if (result != OTI6858_CTRL_PKT_SIZE) {
+		dev_err(&port->dev, "%s(): error reading status\n", __func__);
+		kfree(new_setup);
+		/* we will try again */
+		schedule_delayed_work(&priv->delayed_setup_work,
+							msecs_to_jiffies(2));
+		return;
+	}
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (!OTI6858_CTRL_EQUALS_PENDING(new_setup, priv)) {
+		new_setup->divisor = priv->pending_setup.divisor;
+		new_setup->control = priv->pending_setup.control;
+		new_setup->frame_fmt = priv->pending_setup.frame_fmt;
+
+		spin_unlock_irqrestore(&priv->lock, flags);
+		result = usb_control_msg(port->serial->dev,
+					usb_sndctrlpipe(port->serial->dev, 0),
+					OTI6858_REQ_T_SET_LINE,
+					OTI6858_REQ_SET_LINE,
+					0, 0,
+					new_setup, OTI6858_CTRL_PKT_SIZE,
+					100);
+	} else {
+		spin_unlock_irqrestore(&priv->lock, flags);
+		result = 0;
+	}
+	kfree(new_setup);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (result != OTI6858_CTRL_PKT_SIZE)
+		priv->transient = 0;
+	priv->setup_done = 1;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
+	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
+	if (result != 0) {
+		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
+			__func__, result);
+	}
+}
+
+static void send_data(struct work_struct *work)
+{
+	struct oti6858_private *priv = container_of(work,
+			struct oti6858_private, delayed_write_work.work);
+	struct usb_serial_port *port = priv->port;
+	int count = 0, result;
+	unsigned long flags;
+	u8 *allow;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (priv->flags.write_urb_in_use) {
+		spin_unlock_irqrestore(&priv->lock, flags);
+		schedule_delayed_work(&priv->delayed_write_work,
+						msecs_to_jiffies(2));
+		return;
+	}
+	priv->flags.write_urb_in_use = 1;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	spin_lock_irqsave(&port->lock, flags);
+	count = kfifo_len(&port->write_fifo);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	if (count > port->bulk_out_size)
+		count = port->bulk_out_size;
+
+	if (count != 0) {
+		allow = kmalloc(1, GFP_KERNEL);
+		if (!allow)
+			return;
+
+		result = usb_control_msg(port->serial->dev,
+				usb_rcvctrlpipe(port->serial->dev, 0),
+				OTI6858_REQ_T_CHECK_TXBUFF,
+				OTI6858_REQ_CHECK_TXBUFF,
+				count, 0, allow, 1, 100);
+		if (result != 1 || *allow != 0)
+			count = 0;
+		kfree(allow);
+	}
+
+	if (count == 0) {
+		priv->flags.write_urb_in_use = 0;
+
+		dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
+		result = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
+		if (result != 0) {
+			dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
+				__func__, result);
+		}
+		return;
+	}
+
+	count = kfifo_out_locked(&port->write_fifo,
+					port->write_urb->transfer_buffer,
+					count, &port->lock);
+	port->write_urb->transfer_buffer_length = count;
+	result = usb_submit_urb(port->write_urb, GFP_NOIO);
+	if (result != 0) {
+		dev_err_console(port, "%s(): usb_submit_urb() failed with error %d\n",
+				__func__, result);
+		priv->flags.write_urb_in_use = 0;
+	}
+
+	usb_serial_port_softint(port);
+}
+
+static int oti6858_port_probe(struct usb_serial_port *port)
+{
+	struct oti6858_private *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	spin_lock_init(&priv->lock);
+	priv->port = port;
+	INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
+	INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);
+
+	usb_set_serial_port_data(port, priv);
+
+	port->port.drain_delay = 256;	/* FIXME: check the FIFO length */
+
+	return 0;
+}
+
+static void oti6858_port_remove(struct usb_serial_port *port)
+{
+	struct oti6858_private *priv;
+
+	priv = usb_get_serial_port_data(port);
+	kfree(priv);
+}
+
+static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
+			const unsigned char *buf, int count)
+{
+	if (!count)
+		return count;
+
+	count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
+
+	return count;
+}
+
+static unsigned int oti6858_write_room(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	unsigned int room;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	room = kfifo_avail(&port->write_fifo);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return room;
+}
+
+static unsigned int oti6858_chars_in_buffer(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	unsigned int chars;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	chars = kfifo_len(&port->write_fifo);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return chars;
+}
+
+static void oti6858_init_termios(struct tty_struct *tty)
+{
+	tty_encode_baud_rate(tty, 38400, 38400);
+}
+
+static void oti6858_set_termios(struct tty_struct *tty,
+				struct usb_serial_port *port,
+				const struct ktermios *old_termios)
+{
+	struct oti6858_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	unsigned int cflag;
+	u8 frame_fmt, control;
+	__le16 divisor;
+	int br;
+
+	cflag = tty->termios.c_cflag;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	divisor = priv->pending_setup.divisor;
+	frame_fmt = priv->pending_setup.frame_fmt;
+	control = priv->pending_setup.control;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	frame_fmt &= ~FMT_DATA_BITS_MASK;
+	switch (cflag & CSIZE) {
+	case CS5:
+		frame_fmt |= FMT_DATA_BITS_5;
+		break;
+	case CS6:
+		frame_fmt |= FMT_DATA_BITS_6;
+		break;
+	case CS7:
+		frame_fmt |= FMT_DATA_BITS_7;
+		break;
+	default:
+	case CS8:
+		frame_fmt |= FMT_DATA_BITS_8;
+		break;
+	}
+
+	/* manufacturer claims that this device can work with baud rates
+	 * up to 3 Mbps; I've tested it only on 115200 bps, so I can't
+	 * guarantee that any other baud rate will work (especially
+	 * the higher ones)
+	 */
+	br = tty_get_baud_rate(tty);
+	if (br == 0) {
+		divisor = 0;
+	} else {
+		int real_br;
+		int new_divisor;
+		br = min(br, OTI6858_MAX_BAUD_RATE);
+
+		new_divisor = (96000000 + 8 * br) / (16 * br);
+		real_br = 96000000 / (16 * new_divisor);
+		divisor = cpu_to_le16(new_divisor);
+		tty_encode_baud_rate(tty, real_br, real_br);
+	}
+
+	frame_fmt &= ~FMT_STOP_BITS_MASK;
+	if ((cflag & CSTOPB) != 0)
+		frame_fmt |= FMT_STOP_BITS_2;
+	else
+		frame_fmt |= FMT_STOP_BITS_1;
+
+	frame_fmt &= ~FMT_PARITY_MASK;
+	if ((cflag & PARENB) != 0) {
+		if ((cflag & PARODD) != 0)
+			frame_fmt |= FMT_PARITY_ODD;
+		else
+			frame_fmt |= FMT_PARITY_EVEN;
+	} else {
+		frame_fmt |= FMT_PARITY_NONE;
+	}
+
+	control &= ~CONTROL_MASK;
+	if ((cflag & CRTSCTS) != 0)
+		control |= (CONTROL_DTR_HIGH | CONTROL_RTS_HIGH);
+
+	/* change control lines if we are switching to or from B0 */
+	/* FIXME:
+	spin_lock_irqsave(&priv->lock, flags);
+	control = priv->line_control;
+	if ((cflag & CBAUD) == B0)
+		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
+	else
+		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
+	if (control != priv->line_control) {
+		control = priv->line_control;
+		spin_unlock_irqrestore(&priv->lock, flags);
+		set_control_lines(serial->dev, control);
+	} else {
+		spin_unlock_irqrestore(&priv->lock, flags);
+	}
+	*/
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (divisor != priv->pending_setup.divisor
+			|| control != priv->pending_setup.control
+			|| frame_fmt != priv->pending_setup.frame_fmt) {
+		priv->pending_setup.divisor = divisor;
+		priv->pending_setup.control = control;
+		priv->pending_setup.frame_fmt = frame_fmt;
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port)
+{
+	struct oti6858_private *priv = usb_get_serial_port_data(port);
+	struct usb_serial *serial = port->serial;
+	struct oti6858_control_pkt *buf;
+	unsigned long flags;
+	int result;
+
+	usb_clear_halt(serial->dev, port->write_urb->pipe);
+	usb_clear_halt(serial->dev, port->read_urb->pipe);
+
+	buf = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+				OTI6858_REQ_T_GET_STATUS,
+				OTI6858_REQ_GET_STATUS,
+				0, 0,
+				buf, OTI6858_CTRL_PKT_SIZE,
+				100);
+	if (result != OTI6858_CTRL_PKT_SIZE) {
+		/* assume default (after power-on reset) values */
+		buf->divisor = cpu_to_le16(0x009c);	/* 38400 bps */
+		buf->frame_fmt = 0x03;	/* 8N1 */
+		buf->something = 0x43;
+		buf->control = 0x4c;	/* DTR, RTS */
+		buf->tx_status = 0x00;
+		buf->pin_state = 0x5b;	/* RTS, CTS, DSR, DTR, RI, DCD */
+		buf->rx_bytes_avail = 0x00;
+	}
+
+	spin_lock_irqsave(&priv->lock, flags);
+	memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
+	priv->pending_setup.divisor = buf->divisor;
+	priv->pending_setup.frame_fmt = buf->frame_fmt;
+	priv->pending_setup.control = buf->control;
+	spin_unlock_irqrestore(&priv->lock, flags);
+	kfree(buf);
+
+	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
+	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
+	if (result != 0) {
+		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
+			__func__, result);
+		oti6858_close(port);
+		return result;
+	}
+
+	/* setup termios */
+	if (tty)
+		oti6858_set_termios(tty, port, NULL);
+
+	return 0;
+}
+
+static void oti6858_close(struct usb_serial_port *port)
+{
+	struct oti6858_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	/* clear out any remaining data in the buffer */
+	kfifo_reset_out(&port->write_fifo);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	dev_dbg(&port->dev, "%s(): after buf_clear()\n", __func__);
+
+	/* cancel scheduled setup */
+	cancel_delayed_work_sync(&priv->delayed_setup_work);
+	cancel_delayed_work_sync(&priv->delayed_write_work);
+
+	/* shutdown our urbs */
+	dev_dbg(&port->dev, "%s(): shutting down urbs\n", __func__);
+	usb_kill_urb(port->write_urb);
+	usb_kill_urb(port->read_urb);
+	usb_kill_urb(port->interrupt_in_urb);
+}
+
+static int oti6858_tiocmset(struct tty_struct *tty,
+				unsigned int set, unsigned int clear)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct oti6858_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	u8 control;
+
+	dev_dbg(&port->dev, "%s(set = 0x%08x, clear = 0x%08x)\n",
+		__func__, set, clear);
+
+	/* FIXME: check if this is correct (active high/low) */
+	spin_lock_irqsave(&priv->lock, flags);
+	control = priv->pending_setup.control;
+	if ((set & TIOCM_RTS) != 0)
+		control |= CONTROL_RTS_HIGH;
+	if ((set & TIOCM_DTR) != 0)
+		control |= CONTROL_DTR_HIGH;
+	if ((clear & TIOCM_RTS) != 0)
+		control &= ~CONTROL_RTS_HIGH;
+	if ((clear & TIOCM_DTR) != 0)
+		control &= ~CONTROL_DTR_HIGH;
+
+	if (control != priv->pending_setup.control)
+		priv->pending_setup.control = control;
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+	return 0;
+}
+
+static int oti6858_tiocmget(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct oti6858_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	unsigned pin_state;
+	unsigned result = 0;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	pin_state = priv->status.pin_state & PIN_MASK;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* FIXME: check if this is correct (active high/low) */
+	if ((pin_state & PIN_RTS) != 0)
+		result |= TIOCM_RTS;
+	if ((pin_state & PIN_CTS) != 0)
+		result |= TIOCM_CTS;
+	if ((pin_state & PIN_DSR) != 0)
+		result |= TIOCM_DSR;
+	if ((pin_state & PIN_DTR) != 0)
+		result |= TIOCM_DTR;
+	if ((pin_state & PIN_RI) != 0)
+		result |= TIOCM_RI;
+	if ((pin_state & PIN_DCD) != 0)
+		result |= TIOCM_CD;
+
+	dev_dbg(&port->dev, "%s() = 0x%08x\n", __func__, result);
+
+	return result;
+}
+
+static void oti6858_read_int_callback(struct urb *urb)
+{
+	struct usb_serial_port *port =  urb->context;
+	struct oti6858_private *priv = usb_get_serial_port_data(port);
+	int transient = 0, can_recv = 0, resubmit = 1;
+	int status = urb->status;
+
+	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);
+		break;
+	}
+
+	if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
+		struct oti6858_control_pkt *xs = urb->transfer_buffer;
+		unsigned long flags;
+
+		spin_lock_irqsave(&priv->lock, flags);
+
+		if (!priv->transient) {
+			if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
+				if (xs->rx_bytes_avail == 0) {
+					priv->transient = 4;
+					priv->setup_done = 0;
+					resubmit = 0;
+					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
+					schedule_delayed_work(&priv->delayed_setup_work, 0);
+				}
+			}
+		} else {
+			if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
+				priv->transient = 0;
+			} else if (!priv->setup_done) {
+				resubmit = 0;
+			} else if (--priv->transient == 0) {
+				if (xs->rx_bytes_avail == 0) {
+					priv->transient = 4;
+					priv->setup_done = 0;
+					resubmit = 0;
+					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
+					schedule_delayed_work(&priv->delayed_setup_work, 0);
+				}
+			}
+		}
+
+		if (!priv->transient) {
+			u8 delta = xs->pin_state ^ priv->status.pin_state;
+
+			if (delta & PIN_MSR_MASK) {
+				if (delta & PIN_CTS)
+					port->icount.cts++;
+				if (delta & PIN_DSR)
+					port->icount.dsr++;
+				if (delta & PIN_RI)
+					port->icount.rng++;
+				if (delta & PIN_DCD)
+					port->icount.dcd++;
+
+				wake_up_interruptible(&port->port.delta_msr_wait);
+			}
+
+			memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
+		}
+
+		if (!priv->transient && xs->rx_bytes_avail != 0) {
+			can_recv = xs->rx_bytes_avail;
+			priv->flags.read_urb_in_use = 1;
+		}
+
+		transient = priv->transient;
+		spin_unlock_irqrestore(&priv->lock, flags);
+	}
+
+	if (can_recv) {
+		int result;
+
+		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
+		if (result != 0) {
+			priv->flags.read_urb_in_use = 0;
+			dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
+					" error %d\n", __func__, result);
+		} else {
+			resubmit = 0;
+		}
+	} else if (!transient) {
+		unsigned long flags;
+		int count;
+
+		spin_lock_irqsave(&port->lock, flags);
+		count = kfifo_len(&port->write_fifo);
+		spin_unlock_irqrestore(&port->lock, flags);
+
+		spin_lock_irqsave(&priv->lock, flags);
+		if (priv->flags.write_urb_in_use == 0 && count != 0) {
+			schedule_delayed_work(&priv->delayed_write_work, 0);
+			resubmit = 0;
+		}
+		spin_unlock_irqrestore(&priv->lock, flags);
+	}
+
+	if (resubmit) {
+		int result;
+
+/*		dev_dbg(&urb->dev->dev, "%s(): submitting interrupt urb\n", __func__); */
+		result = usb_submit_urb(urb, GFP_ATOMIC);
+		if (result != 0) {
+			dev_err(&urb->dev->dev,
+					"%s(): usb_submit_urb() failed with"
+					" error %d\n", __func__, result);
+		}
+	}
+}
+
+static void oti6858_read_bulk_callback(struct urb *urb)
+{
+	struct usb_serial_port *port =  urb->context;
+	struct oti6858_private *priv = usb_get_serial_port_data(port);
+	unsigned char *data = urb->transfer_buffer;
+	unsigned long flags;
+	int status = urb->status;
+	int result;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	priv->flags.read_urb_in_use = 0;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	if (status != 0) {
+		dev_dbg(&urb->dev->dev, "%s(): unable to handle the error, exiting\n", __func__);
+		return;
+	}
+
+	if (urb->actual_length > 0) {
+		tty_insert_flip_string(&port->port, data, urb->actual_length);
+		tty_flip_buffer_push(&port->port);
+	}
+
+	/* schedule the interrupt urb */
+	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
+	if (result != 0 && result != -EPERM) {
+		dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
+				" error %d\n", __func__, result);
+	}
+}
+
+static void oti6858_write_bulk_callback(struct urb *urb)
+{
+	struct usb_serial_port *port =  urb->context;
+	struct oti6858_private *priv = usb_get_serial_port_data(port);
+	int status = urb->status;
+	int result;
+
+	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);
+		priv->flags.write_urb_in_use = 0;
+		return;
+	default:
+		/* error in the urb, so we have to resubmit it */
+		dev_dbg(&urb->dev->dev, "%s(): nonzero write bulk status received: %d\n", __func__, status);
+		dev_dbg(&urb->dev->dev, "%s(): overflow in write\n", __func__);
+
+		port->write_urb->transfer_buffer_length = 1;
+		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
+		if (result) {
+			dev_err_console(port, "%s(): usb_submit_urb() failed,"
+					" error %d\n", __func__, result);
+		} else {
+			return;
+		}
+	}
+
+	priv->flags.write_urb_in_use = 0;
+
+	/* schedule the interrupt urb if we are still open */
+	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
+	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
+	if (result != 0) {
+		dev_err(&port->dev, "%s(): failed submitting int urb,"
+					" error %d\n", __func__, result);
+	}
+}
+
+module_usb_serial_driver(serial_drivers, id_table);
+
+MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
+MODULE_AUTHOR(OTI6858_AUTHOR);
+MODULE_LICENSE("GPL v2");