Adding upstream version 6.1.76.upstream/6.1.76

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

1 files changed, 1534 insertions, 0 deletions

diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c
new file mode 100644
index 000000000..45d688e9b
--- /dev/null
+++ b/drivers/usb/serial/digi_acceleport.c
@@ -0,0 +1,1534 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+*  Digi AccelePort USB-4 and USB-2 Serial Converters
+*
+*  Copyright 2000 by Digi International
+*
+*  Shamelessly based on Brian Warner's keyspan_pda.c and Greg Kroah-Hartman's
+*  usb-serial driver.
+*
+*  Peter Berger (pberger@brimson.com)
+*  Al Borchers (borchers@steinerpoint.com)
+*/
+
+#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/uaccess.h>
+#include <linux/usb.h>
+#include <linux/wait.h>
+#include <linux/sched/signal.h>
+#include <linux/usb/serial.h>
+
+/* Defines */
+
+#define DRIVER_AUTHOR "Peter Berger <pberger@brimson.com>, Al Borchers <borchers@steinerpoint.com>"
+#define DRIVER_DESC "Digi AccelePort USB-2/USB-4 Serial Converter driver"
+
+/* port output buffer length -- must be <= transfer buffer length - 2 */
+/* so we can be sure to send the full buffer in one urb */
+#define DIGI_OUT_BUF_SIZE		8
+
+/* port input buffer length -- must be >= transfer buffer length - 3 */
+/* so we can be sure to hold at least one full buffer from one urb */
+#define DIGI_IN_BUF_SIZE		64
+
+/* retry timeout while sleeping */
+#define DIGI_RETRY_TIMEOUT		(HZ/10)
+
+/* timeout while waiting for tty output to drain in close */
+/* this delay is used twice in close, so the total delay could */
+/* be twice this value */
+#define DIGI_CLOSE_TIMEOUT		(5*HZ)
+
+
+/* AccelePort USB Defines */
+
+/* ids */
+#define DIGI_VENDOR_ID			0x05c5
+#define DIGI_2_ID			0x0002	/* USB-2 */
+#define DIGI_4_ID			0x0004	/* USB-4 */
+
+/* commands
+ * "INB": can be used on the in-band endpoint
+ * "OOB": can be used on the out-of-band endpoint
+ */
+#define DIGI_CMD_SET_BAUD_RATE			0	/* INB, OOB */
+#define DIGI_CMD_SET_WORD_SIZE			1	/* INB, OOB */
+#define DIGI_CMD_SET_PARITY			2	/* INB, OOB */
+#define DIGI_CMD_SET_STOP_BITS			3	/* INB, OOB */
+#define DIGI_CMD_SET_INPUT_FLOW_CONTROL		4	/* INB, OOB */
+#define DIGI_CMD_SET_OUTPUT_FLOW_CONTROL	5	/* INB, OOB */
+#define DIGI_CMD_SET_DTR_SIGNAL			6	/* INB, OOB */
+#define DIGI_CMD_SET_RTS_SIGNAL			7	/* INB, OOB */
+#define DIGI_CMD_READ_INPUT_SIGNALS		8	/*      OOB */
+#define DIGI_CMD_IFLUSH_FIFO			9	/*      OOB */
+#define DIGI_CMD_RECEIVE_ENABLE			10	/* INB, OOB */
+#define DIGI_CMD_BREAK_CONTROL			11	/* INB, OOB */
+#define DIGI_CMD_LOCAL_LOOPBACK			12	/* INB, OOB */
+#define DIGI_CMD_TRANSMIT_IDLE			13	/* INB, OOB */
+#define DIGI_CMD_READ_UART_REGISTER		14	/*      OOB */
+#define DIGI_CMD_WRITE_UART_REGISTER		15	/* INB, OOB */
+#define DIGI_CMD_AND_UART_REGISTER		16	/* INB, OOB */
+#define DIGI_CMD_OR_UART_REGISTER		17	/* INB, OOB */
+#define DIGI_CMD_SEND_DATA			18	/* INB      */
+#define DIGI_CMD_RECEIVE_DATA			19	/* INB      */
+#define DIGI_CMD_RECEIVE_DISABLE		20	/* INB      */
+#define DIGI_CMD_GET_PORT_TYPE			21	/*      OOB */
+
+/* baud rates */
+#define DIGI_BAUD_50				0
+#define DIGI_BAUD_75				1
+#define DIGI_BAUD_110				2
+#define DIGI_BAUD_150				3
+#define DIGI_BAUD_200				4
+#define DIGI_BAUD_300				5
+#define DIGI_BAUD_600				6
+#define DIGI_BAUD_1200				7
+#define DIGI_BAUD_1800				8
+#define DIGI_BAUD_2400				9
+#define DIGI_BAUD_4800				10
+#define DIGI_BAUD_7200				11
+#define DIGI_BAUD_9600				12
+#define DIGI_BAUD_14400				13
+#define DIGI_BAUD_19200				14
+#define DIGI_BAUD_28800				15
+#define DIGI_BAUD_38400				16
+#define DIGI_BAUD_57600				17
+#define DIGI_BAUD_76800				18
+#define DIGI_BAUD_115200			19
+#define DIGI_BAUD_153600			20
+#define DIGI_BAUD_230400			21
+#define DIGI_BAUD_460800			22
+
+/* arguments */
+#define DIGI_WORD_SIZE_5			0
+#define DIGI_WORD_SIZE_6			1
+#define DIGI_WORD_SIZE_7			2
+#define DIGI_WORD_SIZE_8			3
+
+#define DIGI_PARITY_NONE			0
+#define DIGI_PARITY_ODD				1
+#define DIGI_PARITY_EVEN			2
+#define DIGI_PARITY_MARK			3
+#define DIGI_PARITY_SPACE			4
+
+#define DIGI_STOP_BITS_1			0
+#define DIGI_STOP_BITS_2			1
+
+#define DIGI_INPUT_FLOW_CONTROL_XON_XOFF	1
+#define DIGI_INPUT_FLOW_CONTROL_RTS		2
+#define DIGI_INPUT_FLOW_CONTROL_DTR		4
+
+#define DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF	1
+#define DIGI_OUTPUT_FLOW_CONTROL_CTS		2
+#define DIGI_OUTPUT_FLOW_CONTROL_DSR		4
+
+#define DIGI_DTR_INACTIVE			0
+#define DIGI_DTR_ACTIVE				1
+#define DIGI_DTR_INPUT_FLOW_CONTROL		2
+
+#define DIGI_RTS_INACTIVE			0
+#define DIGI_RTS_ACTIVE				1
+#define DIGI_RTS_INPUT_FLOW_CONTROL		2
+#define DIGI_RTS_TOGGLE				3
+
+#define DIGI_FLUSH_TX				1
+#define DIGI_FLUSH_RX				2
+#define DIGI_RESUME_TX				4 /* clears xoff condition */
+
+#define DIGI_TRANSMIT_NOT_IDLE			0
+#define DIGI_TRANSMIT_IDLE			1
+
+#define DIGI_DISABLE				0
+#define DIGI_ENABLE				1
+
+#define DIGI_DEASSERT				0
+#define DIGI_ASSERT				1
+
+/* in band status codes */
+#define DIGI_OVERRUN_ERROR			4
+#define DIGI_PARITY_ERROR			8
+#define DIGI_FRAMING_ERROR			16
+#define DIGI_BREAK_ERROR			32
+
+/* out of band status */
+#define DIGI_NO_ERROR				0
+#define DIGI_BAD_FIRST_PARAMETER		1
+#define DIGI_BAD_SECOND_PARAMETER		2
+#define DIGI_INVALID_LINE			3
+#define DIGI_INVALID_OPCODE			4
+
+/* input signals */
+#define DIGI_READ_INPUT_SIGNALS_SLOT		1
+#define DIGI_READ_INPUT_SIGNALS_ERR		2
+#define DIGI_READ_INPUT_SIGNALS_BUSY		4
+#define DIGI_READ_INPUT_SIGNALS_PE		8
+#define DIGI_READ_INPUT_SIGNALS_CTS		16
+#define DIGI_READ_INPUT_SIGNALS_DSR		32
+#define DIGI_READ_INPUT_SIGNALS_RI		64
+#define DIGI_READ_INPUT_SIGNALS_DCD		128
+
+
+/* Structures */
+
+struct digi_serial {
+	spinlock_t ds_serial_lock;
+	struct usb_serial_port *ds_oob_port;	/* out-of-band port */
+	int ds_oob_port_num;			/* index of out-of-band port */
+	int ds_device_started;
+};
+
+struct digi_port {
+	spinlock_t dp_port_lock;
+	int dp_port_num;
+	int dp_out_buf_len;
+	unsigned char dp_out_buf[DIGI_OUT_BUF_SIZE];
+	int dp_write_urb_in_use;
+	unsigned int dp_modem_signals;
+	int dp_transmit_idle;
+	wait_queue_head_t dp_transmit_idle_wait;
+	int dp_throttled;
+	int dp_throttle_restart;
+	wait_queue_head_t dp_flush_wait;
+	wait_queue_head_t dp_close_wait;	/* wait queue for close */
+	wait_queue_head_t write_wait;
+	struct usb_serial_port *dp_port;
+};
+
+
+/* Local Function Declarations */
+
+static int digi_write_oob_command(struct usb_serial_port *port,
+	unsigned char *buf, int count, int interruptible);
+static int digi_write_inb_command(struct usb_serial_port *port,
+	unsigned char *buf, int count, unsigned long timeout);
+static int digi_set_modem_signals(struct usb_serial_port *port,
+	unsigned int modem_signals, int interruptible);
+static int digi_transmit_idle(struct usb_serial_port *port,
+	unsigned long timeout);
+static void digi_rx_throttle(struct tty_struct *tty);
+static void digi_rx_unthrottle(struct tty_struct *tty);
+static void digi_set_termios(struct tty_struct *tty,
+			     struct usb_serial_port *port,
+			     const struct ktermios *old_termios);
+static void digi_break_ctl(struct tty_struct *tty, int break_state);
+static int digi_tiocmget(struct tty_struct *tty);
+static int digi_tiocmset(struct tty_struct *tty, unsigned int set,
+		unsigned int clear);
+static int digi_write(struct tty_struct *tty, struct usb_serial_port *port,
+		const unsigned char *buf, int count);
+static void digi_write_bulk_callback(struct urb *urb);
+static unsigned int digi_write_room(struct tty_struct *tty);
+static unsigned int digi_chars_in_buffer(struct tty_struct *tty);
+static int digi_open(struct tty_struct *tty, struct usb_serial_port *port);
+static void digi_close(struct usb_serial_port *port);
+static void digi_dtr_rts(struct usb_serial_port *port, int on);
+static int digi_startup_device(struct usb_serial *serial);
+static int digi_startup(struct usb_serial *serial);
+static void digi_disconnect(struct usb_serial *serial);
+static void digi_release(struct usb_serial *serial);
+static int digi_port_probe(struct usb_serial_port *port);
+static void digi_port_remove(struct usb_serial_port *port);
+static void digi_read_bulk_callback(struct urb *urb);
+static int digi_read_inb_callback(struct urb *urb);
+static int digi_read_oob_callback(struct urb *urb);
+
+
+static const struct usb_device_id id_table_combined[] = {
+	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_2_ID) },
+	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_4_ID) },
+	{ }						/* Terminating entry */
+};
+
+static const struct usb_device_id id_table_2[] = {
+	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_2_ID) },
+	{ }						/* Terminating entry */
+};
+
+static const struct usb_device_id id_table_4[] = {
+	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_4_ID) },
+	{ }						/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, id_table_combined);
+
+/* device info needed for the Digi serial converter */
+
+static struct usb_serial_driver digi_acceleport_2_device = {
+	.driver = {
+		.owner =		THIS_MODULE,
+		.name =			"digi_2",
+	},
+	.description =			"Digi 2 port USB adapter",
+	.id_table =			id_table_2,
+	.num_ports =			3,
+	.num_bulk_in =			4,
+	.num_bulk_out =			4,
+	.open =				digi_open,
+	.close =			digi_close,
+	.dtr_rts =			digi_dtr_rts,
+	.write =			digi_write,
+	.write_room =			digi_write_room,
+	.write_bulk_callback = 		digi_write_bulk_callback,
+	.read_bulk_callback =		digi_read_bulk_callback,
+	.chars_in_buffer =		digi_chars_in_buffer,
+	.throttle =			digi_rx_throttle,
+	.unthrottle =			digi_rx_unthrottle,
+	.set_termios =			digi_set_termios,
+	.break_ctl =			digi_break_ctl,
+	.tiocmget =			digi_tiocmget,
+	.tiocmset =			digi_tiocmset,
+	.attach =			digi_startup,
+	.disconnect =			digi_disconnect,
+	.release =			digi_release,
+	.port_probe =			digi_port_probe,
+	.port_remove =			digi_port_remove,
+};
+
+static struct usb_serial_driver digi_acceleport_4_device = {
+	.driver = {
+		.owner =		THIS_MODULE,
+		.name =			"digi_4",
+	},
+	.description =			"Digi 4 port USB adapter",
+	.id_table =			id_table_4,
+	.num_ports =			4,
+	.num_bulk_in =			5,
+	.num_bulk_out =			5,
+	.open =				digi_open,
+	.close =			digi_close,
+	.write =			digi_write,
+	.write_room =			digi_write_room,
+	.write_bulk_callback = 		digi_write_bulk_callback,
+	.read_bulk_callback =		digi_read_bulk_callback,
+	.chars_in_buffer =		digi_chars_in_buffer,
+	.throttle =			digi_rx_throttle,
+	.unthrottle =			digi_rx_unthrottle,
+	.set_termios =			digi_set_termios,
+	.break_ctl =			digi_break_ctl,
+	.tiocmget =			digi_tiocmget,
+	.tiocmset =			digi_tiocmset,
+	.attach =			digi_startup,
+	.disconnect =			digi_disconnect,
+	.release =			digi_release,
+	.port_probe =			digi_port_probe,
+	.port_remove =			digi_port_remove,
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+	&digi_acceleport_2_device, &digi_acceleport_4_device, NULL
+};
+
+/* Functions */
+
+/*
+ *  Cond Wait Interruptible Timeout Irqrestore
+ *
+ *  Do spin_unlock_irqrestore and interruptible_sleep_on_timeout
+ *  so that wake ups are not lost if they occur between the unlock
+ *  and the sleep.  In other words, spin_unlock_irqrestore and
+ *  interruptible_sleep_on_timeout are "atomic" with respect to
+ *  wake ups.  This is used to implement condition variables.
+ *
+ *  interruptible_sleep_on_timeout is deprecated and has been replaced
+ *  with the equivalent code.
+ */
+
+static long cond_wait_interruptible_timeout_irqrestore(
+	wait_queue_head_t *q, long timeout,
+	spinlock_t *lock, unsigned long flags)
+__releases(lock)
+{
+	DEFINE_WAIT(wait);
+
+	prepare_to_wait(q, &wait, TASK_INTERRUPTIBLE);
+	spin_unlock_irqrestore(lock, flags);
+	timeout = schedule_timeout(timeout);
+	finish_wait(q, &wait);
+
+	return timeout;
+}
+
+/*
+ *  Digi Write OOB Command
+ *
+ *  Write commands on the out of band port.  Commands are 4
+ *  bytes each, multiple commands can be sent at once, and
+ *  no command will be split across USB packets.  Returns 0
+ *  if successful, -EINTR if interrupted while sleeping and
+ *  the interruptible flag is true, or a negative error
+ *  returned by usb_submit_urb.
+ */
+
+static int digi_write_oob_command(struct usb_serial_port *port,
+	unsigned char *buf, int count, int interruptible)
+{
+	int ret = 0;
+	int len;
+	struct usb_serial_port *oob_port = (struct usb_serial_port *)((struct digi_serial *)(usb_get_serial_data(port->serial)))->ds_oob_port;
+	struct digi_port *oob_priv = usb_get_serial_port_data(oob_port);
+	unsigned long flags;
+
+	dev_dbg(&port->dev,
+		"digi_write_oob_command: TOP: port=%d, count=%d\n",
+		oob_priv->dp_port_num, count);
+
+	spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
+	while (count > 0) {
+		while (oob_priv->dp_write_urb_in_use) {
+			cond_wait_interruptible_timeout_irqrestore(
+				&oob_priv->write_wait, DIGI_RETRY_TIMEOUT,
+				&oob_priv->dp_port_lock, flags);
+			if (interruptible && signal_pending(current))
+				return -EINTR;
+			spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
+		}
+
+		/* len must be a multiple of 4, so commands are not split */
+		len = min(count, oob_port->bulk_out_size);
+		if (len > 4)
+			len &= ~3;
+		memcpy(oob_port->write_urb->transfer_buffer, buf, len);
+		oob_port->write_urb->transfer_buffer_length = len;
+		ret = usb_submit_urb(oob_port->write_urb, GFP_ATOMIC);
+		if (ret == 0) {
+			oob_priv->dp_write_urb_in_use = 1;
+			count -= len;
+			buf += len;
+		}
+	}
+	spin_unlock_irqrestore(&oob_priv->dp_port_lock, flags);
+	if (ret)
+		dev_err(&port->dev, "%s: usb_submit_urb failed, ret=%d\n",
+			__func__, ret);
+	return ret;
+
+}
+
+
+/*
+ *  Digi Write In Band Command
+ *
+ *  Write commands on the given port.  Commands are 4
+ *  bytes each, multiple commands can be sent at once, and
+ *  no command will be split across USB packets.  If timeout
+ *  is non-zero, write in band command will return after
+ *  waiting unsuccessfully for the URB status to clear for
+ *  timeout ticks.  Returns 0 if successful, or a negative
+ *  error returned by digi_write.
+ */
+
+static int digi_write_inb_command(struct usb_serial_port *port,
+	unsigned char *buf, int count, unsigned long timeout)
+{
+	int ret = 0;
+	int len;
+	struct digi_port *priv = usb_get_serial_port_data(port);
+	unsigned char *data = port->write_urb->transfer_buffer;
+	unsigned long flags;
+
+	dev_dbg(&port->dev, "digi_write_inb_command: TOP: port=%d, count=%d\n",
+		priv->dp_port_num, count);
+
+	if (timeout)
+		timeout += jiffies;
+	else
+		timeout = ULONG_MAX;
+
+	spin_lock_irqsave(&priv->dp_port_lock, flags);
+	while (count > 0 && ret == 0) {
+		while (priv->dp_write_urb_in_use &&
+		       time_before(jiffies, timeout)) {
+			cond_wait_interruptible_timeout_irqrestore(
+				&priv->write_wait, DIGI_RETRY_TIMEOUT,
+				&priv->dp_port_lock, flags);
+			if (signal_pending(current))
+				return -EINTR;
+			spin_lock_irqsave(&priv->dp_port_lock, flags);
+		}
+
+		/* len must be a multiple of 4 and small enough to */
+		/* guarantee the write will send buffered data first, */
+		/* so commands are in order with data and not split */
+		len = min(count, port->bulk_out_size-2-priv->dp_out_buf_len);
+		if (len > 4)
+			len &= ~3;
+
+		/* write any buffered data first */
+		if (priv->dp_out_buf_len > 0) {
+			data[0] = DIGI_CMD_SEND_DATA;
+			data[1] = priv->dp_out_buf_len;
+			memcpy(data + 2, priv->dp_out_buf,
+				priv->dp_out_buf_len);
+			memcpy(data + 2 + priv->dp_out_buf_len, buf, len);
+			port->write_urb->transfer_buffer_length
+				= priv->dp_out_buf_len + 2 + len;
+		} else {
+			memcpy(data, buf, len);
+			port->write_urb->transfer_buffer_length = len;
+		}
+
+		ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
+		if (ret == 0) {
+			priv->dp_write_urb_in_use = 1;
+			priv->dp_out_buf_len = 0;
+			count -= len;
+			buf += len;
+		}
+
+	}
+	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+
+	if (ret)
+		dev_err(&port->dev,
+			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
+			__func__, ret, priv->dp_port_num);
+	return ret;
+}
+
+
+/*
+ *  Digi Set Modem Signals
+ *
+ *  Sets or clears DTR and RTS on the port, according to the
+ *  modem_signals argument.  Use TIOCM_DTR and TIOCM_RTS flags
+ *  for the modem_signals argument.  Returns 0 if successful,
+ *  -EINTR if interrupted while sleeping, or a non-zero error
+ *  returned by usb_submit_urb.
+ */
+
+static int digi_set_modem_signals(struct usb_serial_port *port,
+	unsigned int modem_signals, int interruptible)
+{
+
+	int ret;
+	struct digi_port *port_priv = usb_get_serial_port_data(port);
+	struct usb_serial_port *oob_port = (struct usb_serial_port *) ((struct digi_serial *)(usb_get_serial_data(port->serial)))->ds_oob_port;
+	struct digi_port *oob_priv = usb_get_serial_port_data(oob_port);
+	unsigned char *data = oob_port->write_urb->transfer_buffer;
+	unsigned long flags;
+
+	dev_dbg(&port->dev,
+		"digi_set_modem_signals: TOP: port=%d, modem_signals=0x%x\n",
+		port_priv->dp_port_num, modem_signals);
+
+	spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
+	spin_lock(&port_priv->dp_port_lock);
+
+	while (oob_priv->dp_write_urb_in_use) {
+		spin_unlock(&port_priv->dp_port_lock);
+		cond_wait_interruptible_timeout_irqrestore(
+			&oob_priv->write_wait, DIGI_RETRY_TIMEOUT,
+			&oob_priv->dp_port_lock, flags);
+		if (interruptible && signal_pending(current))
+			return -EINTR;
+		spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
+		spin_lock(&port_priv->dp_port_lock);
+	}
+	data[0] = DIGI_CMD_SET_DTR_SIGNAL;
+	data[1] = port_priv->dp_port_num;
+	data[2] = (modem_signals & TIOCM_DTR) ?
+					DIGI_DTR_ACTIVE : DIGI_DTR_INACTIVE;
+	data[3] = 0;
+	data[4] = DIGI_CMD_SET_RTS_SIGNAL;
+	data[5] = port_priv->dp_port_num;
+	data[6] = (modem_signals & TIOCM_RTS) ?
+					DIGI_RTS_ACTIVE : DIGI_RTS_INACTIVE;
+	data[7] = 0;
+
+	oob_port->write_urb->transfer_buffer_length = 8;
+
+	ret = usb_submit_urb(oob_port->write_urb, GFP_ATOMIC);
+	if (ret == 0) {
+		oob_priv->dp_write_urb_in_use = 1;
+		port_priv->dp_modem_signals &= ~(TIOCM_DTR | TIOCM_RTS);
+		port_priv->dp_modem_signals |=
+				modem_signals & (TIOCM_DTR | TIOCM_RTS);
+	}
+	spin_unlock(&port_priv->dp_port_lock);
+	spin_unlock_irqrestore(&oob_priv->dp_port_lock, flags);
+	if (ret)
+		dev_err(&port->dev, "%s: usb_submit_urb failed, ret=%d\n",
+			__func__, ret);
+	return ret;
+}
+
+/*
+ *  Digi Transmit Idle
+ *
+ *  Digi transmit idle waits, up to timeout ticks, for the transmitter
+ *  to go idle.  It returns 0 if successful or a negative error.
+ *
+ *  There are race conditions here if more than one process is calling
+ *  digi_transmit_idle on the same port at the same time.  However, this
+ *  is only called from close, and only one process can be in close on a
+ *  port at a time, so its ok.
+ */
+
+static int digi_transmit_idle(struct usb_serial_port *port,
+	unsigned long timeout)
+{
+	int ret;
+	unsigned char buf[2];
+	struct digi_port *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->dp_port_lock, flags);
+	priv->dp_transmit_idle = 0;
+	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+
+	buf[0] = DIGI_CMD_TRANSMIT_IDLE;
+	buf[1] = 0;
+
+	timeout += jiffies;
+
+	ret = digi_write_inb_command(port, buf, 2, timeout - jiffies);
+	if (ret != 0)
+		return ret;
+
+	spin_lock_irqsave(&priv->dp_port_lock, flags);
+
+	while (time_before(jiffies, timeout) && !priv->dp_transmit_idle) {
+		cond_wait_interruptible_timeout_irqrestore(
+			&priv->dp_transmit_idle_wait, DIGI_RETRY_TIMEOUT,
+			&priv->dp_port_lock, flags);
+		if (signal_pending(current))
+			return -EINTR;
+		spin_lock_irqsave(&priv->dp_port_lock, flags);
+	}
+	priv->dp_transmit_idle = 0;
+	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+	return 0;
+
+}
+
+
+static void digi_rx_throttle(struct tty_struct *tty)
+{
+	unsigned long flags;
+	struct usb_serial_port *port = tty->driver_data;
+	struct digi_port *priv = usb_get_serial_port_data(port);
+
+	/* stop receiving characters by not resubmitting the read urb */
+	spin_lock_irqsave(&priv->dp_port_lock, flags);
+	priv->dp_throttled = 1;
+	priv->dp_throttle_restart = 0;
+	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+}
+
+
+static void digi_rx_unthrottle(struct tty_struct *tty)
+{
+	int ret = 0;
+	unsigned long flags;
+	struct usb_serial_port *port = tty->driver_data;
+	struct digi_port *priv = usb_get_serial_port_data(port);
+
+	spin_lock_irqsave(&priv->dp_port_lock, flags);
+
+	/* restart read chain */
+	if (priv->dp_throttle_restart)
+		ret = usb_submit_urb(port->read_urb, GFP_ATOMIC);
+
+	/* turn throttle off */
+	priv->dp_throttled = 0;
+	priv->dp_throttle_restart = 0;
+
+	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+
+	if (ret)
+		dev_err(&port->dev,
+			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
+			__func__, ret, priv->dp_port_num);
+}
+
+
+static void digi_set_termios(struct tty_struct *tty,
+			     struct usb_serial_port *port,
+			     const struct ktermios *old_termios)
+{
+	struct digi_port *priv = usb_get_serial_port_data(port);
+	struct device *dev = &port->dev;
+	unsigned int iflag = tty->termios.c_iflag;
+	unsigned int cflag = tty->termios.c_cflag;
+	unsigned int old_iflag = old_termios->c_iflag;
+	unsigned int old_cflag = old_termios->c_cflag;
+	unsigned char buf[32];
+	unsigned int modem_signals;
+	int arg, ret;
+	int i = 0;
+	speed_t baud;
+
+	dev_dbg(dev,
+		"digi_set_termios: TOP: port=%d, iflag=0x%x, old_iflag=0x%x, cflag=0x%x, old_cflag=0x%x\n",
+		priv->dp_port_num, iflag, old_iflag, cflag, old_cflag);
+
+	/* set baud rate */
+	baud = tty_get_baud_rate(tty);
+	if (baud != tty_termios_baud_rate(old_termios)) {
+		arg = -1;
+
+		/* reassert DTR and (maybe) RTS on transition from B0 */
+		if ((old_cflag & CBAUD) == B0) {
+			/* don't set RTS if using hardware flow control */
+			/* and throttling input */
+			modem_signals = TIOCM_DTR;
+			if (!C_CRTSCTS(tty) || !tty_throttled(tty))
+				modem_signals |= TIOCM_RTS;
+			digi_set_modem_signals(port, modem_signals, 1);
+		}
+		switch (baud) {
+		/* drop DTR and RTS on transition to B0 */
+		case 0: digi_set_modem_signals(port, 0, 1); break;
+		case 50: arg = DIGI_BAUD_50; break;
+		case 75: arg = DIGI_BAUD_75; break;
+		case 110: arg = DIGI_BAUD_110; break;
+		case 150: arg = DIGI_BAUD_150; break;
+		case 200: arg = DIGI_BAUD_200; break;
+		case 300: arg = DIGI_BAUD_300; break;
+		case 600: arg = DIGI_BAUD_600; break;
+		case 1200: arg = DIGI_BAUD_1200; break;
+		case 1800: arg = DIGI_BAUD_1800; break;
+		case 2400: arg = DIGI_BAUD_2400; break;
+		case 4800: arg = DIGI_BAUD_4800; break;
+		case 9600: arg = DIGI_BAUD_9600; break;
+		case 19200: arg = DIGI_BAUD_19200; break;
+		case 38400: arg = DIGI_BAUD_38400; break;
+		case 57600: arg = DIGI_BAUD_57600; break;
+		case 115200: arg = DIGI_BAUD_115200; break;
+		case 230400: arg = DIGI_BAUD_230400; break;
+		case 460800: arg = DIGI_BAUD_460800; break;
+		default:
+			arg = DIGI_BAUD_9600;
+			baud = 9600;
+			break;
+		}
+		if (arg != -1) {
+			buf[i++] = DIGI_CMD_SET_BAUD_RATE;
+			buf[i++] = priv->dp_port_num;
+			buf[i++] = arg;
+			buf[i++] = 0;
+		}
+	}
+	/* set parity */
+	tty->termios.c_cflag &= ~CMSPAR;
+
+	if ((cflag & (PARENB | PARODD)) != (old_cflag & (PARENB | PARODD))) {
+		if (cflag & PARENB) {
+			if (cflag & PARODD)
+				arg = DIGI_PARITY_ODD;
+			else
+				arg = DIGI_PARITY_EVEN;
+		} else {
+			arg = DIGI_PARITY_NONE;
+		}
+		buf[i++] = DIGI_CMD_SET_PARITY;
+		buf[i++] = priv->dp_port_num;
+		buf[i++] = arg;
+		buf[i++] = 0;
+	}
+	/* set word size */
+	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
+		arg = -1;
+		switch (cflag & CSIZE) {
+		case CS5: arg = DIGI_WORD_SIZE_5; break;
+		case CS6: arg = DIGI_WORD_SIZE_6; break;
+		case CS7: arg = DIGI_WORD_SIZE_7; break;
+		case CS8: arg = DIGI_WORD_SIZE_8; break;
+		default:
+			dev_dbg(dev,
+				"digi_set_termios: can't handle word size %d\n",
+				cflag & CSIZE);
+			break;
+		}
+
+		if (arg != -1) {
+			buf[i++] = DIGI_CMD_SET_WORD_SIZE;
+			buf[i++] = priv->dp_port_num;
+			buf[i++] = arg;
+			buf[i++] = 0;
+		}
+
+	}
+
+	/* set stop bits */
+	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
+
+		if ((cflag & CSTOPB))
+			arg = DIGI_STOP_BITS_2;
+		else
+			arg = DIGI_STOP_BITS_1;
+
+		buf[i++] = DIGI_CMD_SET_STOP_BITS;
+		buf[i++] = priv->dp_port_num;
+		buf[i++] = arg;
+		buf[i++] = 0;
+
+	}
+
+	/* set input flow control */
+	if ((iflag & IXOFF) != (old_iflag & IXOFF) ||
+			(cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
+		arg = 0;
+		if (iflag & IXOFF)
+			arg |= DIGI_INPUT_FLOW_CONTROL_XON_XOFF;
+		else
+			arg &= ~DIGI_INPUT_FLOW_CONTROL_XON_XOFF;
+
+		if (cflag & CRTSCTS) {
+			arg |= DIGI_INPUT_FLOW_CONTROL_RTS;
+
+			/* On USB-4 it is necessary to assert RTS prior */
+			/* to selecting RTS input flow control.  */
+			buf[i++] = DIGI_CMD_SET_RTS_SIGNAL;
+			buf[i++] = priv->dp_port_num;
+			buf[i++] = DIGI_RTS_ACTIVE;
+			buf[i++] = 0;
+
+		} else {
+			arg &= ~DIGI_INPUT_FLOW_CONTROL_RTS;
+		}
+		buf[i++] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
+		buf[i++] = priv->dp_port_num;
+		buf[i++] = arg;
+		buf[i++] = 0;
+	}
+
+	/* set output flow control */
+	if ((iflag & IXON) != (old_iflag & IXON) ||
+			(cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
+		arg = 0;
+		if (iflag & IXON)
+			arg |= DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF;
+		else
+			arg &= ~DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF;
+
+		if (cflag & CRTSCTS)
+			arg |= DIGI_OUTPUT_FLOW_CONTROL_CTS;
+		else
+			arg &= ~DIGI_OUTPUT_FLOW_CONTROL_CTS;
+
+		buf[i++] = DIGI_CMD_SET_OUTPUT_FLOW_CONTROL;
+		buf[i++] = priv->dp_port_num;
+		buf[i++] = arg;
+		buf[i++] = 0;
+	}
+
+	/* set receive enable/disable */
+	if ((cflag & CREAD) != (old_cflag & CREAD)) {
+		if (cflag & CREAD)
+			arg = DIGI_ENABLE;
+		else
+			arg = DIGI_DISABLE;
+
+		buf[i++] = DIGI_CMD_RECEIVE_ENABLE;
+		buf[i++] = priv->dp_port_num;
+		buf[i++] = arg;
+		buf[i++] = 0;
+	}
+	ret = digi_write_oob_command(port, buf, i, 1);
+	if (ret != 0)
+		dev_dbg(dev, "digi_set_termios: write oob failed, ret=%d\n", ret);
+	tty_encode_baud_rate(tty, baud, baud);
+}
+
+
+static void digi_break_ctl(struct tty_struct *tty, int break_state)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	unsigned char buf[4];
+
+	buf[0] = DIGI_CMD_BREAK_CONTROL;
+	buf[1] = 2;				/* length */
+	buf[2] = break_state ? 1 : 0;
+	buf[3] = 0;				/* pad */
+	digi_write_inb_command(port, buf, 4, 0);
+}
+
+
+static int digi_tiocmget(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct digi_port *priv = usb_get_serial_port_data(port);
+	unsigned int val;
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->dp_port_lock, flags);
+	val = priv->dp_modem_signals;
+	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+	return val;
+}
+
+
+static int digi_tiocmset(struct tty_struct *tty,
+					unsigned int set, unsigned int clear)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct digi_port *priv = usb_get_serial_port_data(port);
+	unsigned int val;
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->dp_port_lock, flags);
+	val = (priv->dp_modem_signals & ~clear) | set;
+	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+	return digi_set_modem_signals(port, val, 1);
+}
+
+
+static int digi_write(struct tty_struct *tty, struct usb_serial_port *port,
+					const unsigned char *buf, int count)
+{
+
+	int ret, data_len, new_len;
+	struct digi_port *priv = usb_get_serial_port_data(port);
+	unsigned char *data = port->write_urb->transfer_buffer;
+	unsigned long flags;
+
+	dev_dbg(&port->dev, "digi_write: TOP: port=%d, count=%d\n",
+		priv->dp_port_num, count);
+
+	/* copy user data (which can sleep) before getting spin lock */
+	count = min(count, port->bulk_out_size-2);
+	count = min(64, count);
+
+	/* be sure only one write proceeds at a time */
+	/* there are races on the port private buffer */
+	spin_lock_irqsave(&priv->dp_port_lock, flags);
+
+	/* wait for urb status clear to submit another urb */
+	if (priv->dp_write_urb_in_use) {
+		/* buffer data if count is 1 (probably put_char) if possible */
+		if (count == 1 && priv->dp_out_buf_len < DIGI_OUT_BUF_SIZE) {
+			priv->dp_out_buf[priv->dp_out_buf_len++] = *buf;
+			new_len = 1;
+		} else {
+			new_len = 0;
+		}
+		spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+		return new_len;
+	}
+
+	/* allow space for any buffered data and for new data, up to */
+	/* transfer buffer size - 2 (for command and length bytes) */
+	new_len = min(count, port->bulk_out_size-2-priv->dp_out_buf_len);
+	data_len = new_len + priv->dp_out_buf_len;
+
+	if (data_len == 0) {
+		spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+		return 0;
+	}
+
+	port->write_urb->transfer_buffer_length = data_len+2;
+
+	*data++ = DIGI_CMD_SEND_DATA;
+	*data++ = data_len;
+
+	/* copy in buffered data first */
+	memcpy(data, priv->dp_out_buf, priv->dp_out_buf_len);
+	data += priv->dp_out_buf_len;
+
+	/* copy in new data */
+	memcpy(data, buf, new_len);
+
+	ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
+	if (ret == 0) {
+		priv->dp_write_urb_in_use = 1;
+		ret = new_len;
+		priv->dp_out_buf_len = 0;
+	}
+
+	/* return length of new data written, or error */
+	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+	if (ret < 0)
+		dev_err_console(port,
+			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
+			__func__, ret, priv->dp_port_num);
+	dev_dbg(&port->dev, "digi_write: returning %d\n", ret);
+	return ret;
+
+}
+
+static void digi_write_bulk_callback(struct urb *urb)
+{
+
+	struct usb_serial_port *port = urb->context;
+	struct usb_serial *serial;
+	struct digi_port *priv;
+	struct digi_serial *serial_priv;
+	unsigned long flags;
+	int ret = 0;
+	int status = urb->status;
+	bool wakeup;
+
+	/* port and serial sanity check */
+	if (port == NULL || (priv = usb_get_serial_port_data(port)) == NULL) {
+		pr_err("%s: port or port->private is NULL, status=%d\n",
+			__func__, status);
+		return;
+	}
+	serial = port->serial;
+	if (serial == NULL || (serial_priv = usb_get_serial_data(serial)) == NULL) {
+		dev_err(&port->dev,
+			"%s: serial or serial->private is NULL, status=%d\n",
+			__func__, status);
+		return;
+	}
+
+	/* handle oob callback */
+	if (priv->dp_port_num == serial_priv->ds_oob_port_num) {
+		dev_dbg(&port->dev, "digi_write_bulk_callback: oob callback\n");
+		spin_lock_irqsave(&priv->dp_port_lock, flags);
+		priv->dp_write_urb_in_use = 0;
+		wake_up_interruptible(&priv->write_wait);
+		spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+		return;
+	}
+
+	/* try to send any buffered data on this port */
+	wakeup = true;
+	spin_lock_irqsave(&priv->dp_port_lock, flags);
+	priv->dp_write_urb_in_use = 0;
+	if (priv->dp_out_buf_len > 0) {
+		*((unsigned char *)(port->write_urb->transfer_buffer))
+			= (unsigned char)DIGI_CMD_SEND_DATA;
+		*((unsigned char *)(port->write_urb->transfer_buffer) + 1)
+			= (unsigned char)priv->dp_out_buf_len;
+		port->write_urb->transfer_buffer_length =
+						priv->dp_out_buf_len + 2;
+		memcpy(port->write_urb->transfer_buffer + 2, priv->dp_out_buf,
+			priv->dp_out_buf_len);
+		ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
+		if (ret == 0) {
+			priv->dp_write_urb_in_use = 1;
+			priv->dp_out_buf_len = 0;
+			wakeup = false;
+		}
+	}
+	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+
+	if (ret && ret != -EPERM)
+		dev_err_console(port,
+			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
+			__func__, ret, priv->dp_port_num);
+
+	if (wakeup)
+		tty_port_tty_wakeup(&port->port);
+}
+
+static unsigned int digi_write_room(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct digi_port *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	unsigned int room;
+
+	spin_lock_irqsave(&priv->dp_port_lock, flags);
+
+	if (priv->dp_write_urb_in_use)
+		room = 0;
+	else
+		room = port->bulk_out_size - 2 - priv->dp_out_buf_len;
+
+	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+	dev_dbg(&port->dev, "digi_write_room: port=%d, room=%u\n", priv->dp_port_num, room);
+	return room;
+
+}
+
+static unsigned int digi_chars_in_buffer(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct digi_port *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	unsigned int chars;
+
+	spin_lock_irqsave(&priv->dp_port_lock, flags);
+	if (priv->dp_write_urb_in_use)
+		chars = port->bulk_out_size - 2;
+	else
+		chars = priv->dp_out_buf_len;
+	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+
+	dev_dbg(&port->dev, "%s: port=%d, chars=%d\n", __func__,
+			priv->dp_port_num, chars);
+	return chars;
+}
+
+static void digi_dtr_rts(struct usb_serial_port *port, int on)
+{
+	/* Adjust DTR and RTS */
+	digi_set_modem_signals(port, on * (TIOCM_DTR | TIOCM_RTS), 1);
+}
+
+static int digi_open(struct tty_struct *tty, struct usb_serial_port *port)
+{
+	int ret;
+	unsigned char buf[32];
+	struct digi_port *priv = usb_get_serial_port_data(port);
+	struct ktermios not_termios;
+
+	/* be sure the device is started up */
+	if (digi_startup_device(port->serial) != 0)
+		return -ENXIO;
+
+	/* read modem signals automatically whenever they change */
+	buf[0] = DIGI_CMD_READ_INPUT_SIGNALS;
+	buf[1] = priv->dp_port_num;
+	buf[2] = DIGI_ENABLE;
+	buf[3] = 0;
+
+	/* flush fifos */
+	buf[4] = DIGI_CMD_IFLUSH_FIFO;
+	buf[5] = priv->dp_port_num;
+	buf[6] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
+	buf[7] = 0;
+
+	ret = digi_write_oob_command(port, buf, 8, 1);
+	if (ret != 0)
+		dev_dbg(&port->dev, "digi_open: write oob failed, ret=%d\n", ret);
+
+	/* set termios settings */
+	if (tty) {
+		not_termios.c_cflag = ~tty->termios.c_cflag;
+		not_termios.c_iflag = ~tty->termios.c_iflag;
+		digi_set_termios(tty, port, &not_termios);
+	}
+	return 0;
+}
+
+
+static void digi_close(struct usb_serial_port *port)
+{
+	DEFINE_WAIT(wait);
+	int ret;
+	unsigned char buf[32];
+	struct digi_port *priv = usb_get_serial_port_data(port);
+
+	mutex_lock(&port->serial->disc_mutex);
+	/* if disconnected, just clear flags */
+	if (port->serial->disconnected)
+		goto exit;
+
+	/* FIXME: Transmit idle belongs in the wait_unti_sent path */
+	digi_transmit_idle(port, DIGI_CLOSE_TIMEOUT);
+
+	/* disable input flow control */
+	buf[0] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
+	buf[1] = priv->dp_port_num;
+	buf[2] = DIGI_DISABLE;
+	buf[3] = 0;
+
+	/* disable output flow control */
+	buf[4] = DIGI_CMD_SET_OUTPUT_FLOW_CONTROL;
+	buf[5] = priv->dp_port_num;
+	buf[6] = DIGI_DISABLE;
+	buf[7] = 0;
+
+	/* disable reading modem signals automatically */
+	buf[8] = DIGI_CMD_READ_INPUT_SIGNALS;
+	buf[9] = priv->dp_port_num;
+	buf[10] = DIGI_DISABLE;
+	buf[11] = 0;
+
+	/* disable receive */
+	buf[12] = DIGI_CMD_RECEIVE_ENABLE;
+	buf[13] = priv->dp_port_num;
+	buf[14] = DIGI_DISABLE;
+	buf[15] = 0;
+
+	/* flush fifos */
+	buf[16] = DIGI_CMD_IFLUSH_FIFO;
+	buf[17] = priv->dp_port_num;
+	buf[18] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
+	buf[19] = 0;
+
+	ret = digi_write_oob_command(port, buf, 20, 0);
+	if (ret != 0)
+		dev_dbg(&port->dev, "digi_close: write oob failed, ret=%d\n",
+									ret);
+	/* wait for final commands on oob port to complete */
+	prepare_to_wait(&priv->dp_flush_wait, &wait,
+			TASK_INTERRUPTIBLE);
+	schedule_timeout(DIGI_CLOSE_TIMEOUT);
+	finish_wait(&priv->dp_flush_wait, &wait);
+
+	/* shutdown any outstanding bulk writes */
+	usb_kill_urb(port->write_urb);
+exit:
+	spin_lock_irq(&priv->dp_port_lock);
+	priv->dp_write_urb_in_use = 0;
+	wake_up_interruptible(&priv->dp_close_wait);
+	spin_unlock_irq(&priv->dp_port_lock);
+	mutex_unlock(&port->serial->disc_mutex);
+}
+
+
+/*
+ *  Digi Startup Device
+ *
+ *  Starts reads on all ports.  Must be called AFTER startup, with
+ *  urbs initialized.  Returns 0 if successful, non-zero error otherwise.
+ */
+
+static int digi_startup_device(struct usb_serial *serial)
+{
+	int i, ret = 0;
+	struct digi_serial *serial_priv = usb_get_serial_data(serial);
+	struct usb_serial_port *port;
+
+	/* be sure this happens exactly once */
+	spin_lock(&serial_priv->ds_serial_lock);
+	if (serial_priv->ds_device_started) {
+		spin_unlock(&serial_priv->ds_serial_lock);
+		return 0;
+	}
+	serial_priv->ds_device_started = 1;
+	spin_unlock(&serial_priv->ds_serial_lock);
+
+	/* start reading from each bulk in endpoint for the device */
+	/* set USB_DISABLE_SPD flag for write bulk urbs */
+	for (i = 0; i < serial->type->num_ports + 1; i++) {
+		port = serial->port[i];
+		ret = usb_submit_urb(port->read_urb, GFP_KERNEL);
+		if (ret != 0) {
+			dev_err(&port->dev,
+				"%s: usb_submit_urb failed, ret=%d, port=%d\n",
+				__func__, ret, i);
+			break;
+		}
+	}
+	return ret;
+}
+
+static int digi_port_init(struct usb_serial_port *port, unsigned port_num)
+{
+	struct digi_port *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	spin_lock_init(&priv->dp_port_lock);
+	priv->dp_port_num = port_num;
+	init_waitqueue_head(&priv->dp_transmit_idle_wait);
+	init_waitqueue_head(&priv->dp_flush_wait);
+	init_waitqueue_head(&priv->dp_close_wait);
+	init_waitqueue_head(&priv->write_wait);
+	priv->dp_port = port;
+
+	usb_set_serial_port_data(port, priv);
+
+	return 0;
+}
+
+static int digi_startup(struct usb_serial *serial)
+{
+	struct digi_serial *serial_priv;
+	int ret;
+
+	serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL);
+	if (!serial_priv)
+		return -ENOMEM;
+
+	spin_lock_init(&serial_priv->ds_serial_lock);
+	serial_priv->ds_oob_port_num = serial->type->num_ports;
+	serial_priv->ds_oob_port = serial->port[serial_priv->ds_oob_port_num];
+
+	ret = digi_port_init(serial_priv->ds_oob_port,
+						serial_priv->ds_oob_port_num);
+	if (ret) {
+		kfree(serial_priv);
+		return ret;
+	}
+
+	usb_set_serial_data(serial, serial_priv);
+
+	return 0;
+}
+
+
+static void digi_disconnect(struct usb_serial *serial)
+{
+	int i;
+
+	/* stop reads and writes on all ports */
+	for (i = 0; i < serial->type->num_ports + 1; i++) {
+		usb_kill_urb(serial->port[i]->read_urb);
+		usb_kill_urb(serial->port[i]->write_urb);
+	}
+}
+
+
+static void digi_release(struct usb_serial *serial)
+{
+	struct digi_serial *serial_priv;
+	struct digi_port *priv;
+
+	serial_priv = usb_get_serial_data(serial);
+
+	priv = usb_get_serial_port_data(serial_priv->ds_oob_port);
+	kfree(priv);
+
+	kfree(serial_priv);
+}
+
+static int digi_port_probe(struct usb_serial_port *port)
+{
+	return digi_port_init(port, port->port_number);
+}
+
+static void digi_port_remove(struct usb_serial_port *port)
+{
+	struct digi_port *priv;
+
+	priv = usb_get_serial_port_data(port);
+	kfree(priv);
+}
+
+static void digi_read_bulk_callback(struct urb *urb)
+{
+	struct usb_serial_port *port = urb->context;
+	struct digi_port *priv;
+	struct digi_serial *serial_priv;
+	int ret;
+	int status = urb->status;
+
+	/* port sanity check, do not resubmit if port is not valid */
+	if (port == NULL)
+		return;
+	priv = usb_get_serial_port_data(port);
+	if (priv == NULL) {
+		dev_err(&port->dev, "%s: port->private is NULL, status=%d\n",
+			__func__, status);
+		return;
+	}
+	if (port->serial == NULL ||
+		(serial_priv = usb_get_serial_data(port->serial)) == NULL) {
+		dev_err(&port->dev, "%s: serial is bad or serial->private "
+			"is NULL, status=%d\n", __func__, status);
+		return;
+	}
+
+	/* do not resubmit urb if it has any status error */
+	if (status) {
+		dev_err(&port->dev,
+			"%s: nonzero read bulk status: status=%d, port=%d\n",
+			__func__, status, priv->dp_port_num);
+		return;
+	}
+
+	/* handle oob or inb callback, do not resubmit if error */
+	if (priv->dp_port_num == serial_priv->ds_oob_port_num) {
+		if (digi_read_oob_callback(urb) != 0)
+			return;
+	} else {
+		if (digi_read_inb_callback(urb) != 0)
+			return;
+	}
+
+	/* continue read */
+	ret = usb_submit_urb(urb, GFP_ATOMIC);
+	if (ret != 0 && ret != -EPERM) {
+		dev_err(&port->dev,
+			"%s: failed resubmitting urb, ret=%d, port=%d\n",
+			__func__, ret, priv->dp_port_num);
+	}
+
+}
+
+/*
+ *  Digi Read INB Callback
+ *
+ *  Digi Read INB Callback handles reads on the in band ports, sending
+ *  the data on to the tty subsystem.  When called we know port and
+ *  port->private are not NULL and port->serial has been validated.
+ *  It returns 0 if successful, 1 if successful but the port is
+ *  throttled, and -1 if the sanity checks failed.
+ */
+
+static int digi_read_inb_callback(struct urb *urb)
+{
+	struct usb_serial_port *port = urb->context;
+	struct digi_port *priv = usb_get_serial_port_data(port);
+	unsigned char *buf = urb->transfer_buffer;
+	unsigned long flags;
+	int opcode;
+	int len;
+	int port_status;
+	unsigned char *data;
+	int tty_flag, throttled;
+
+	/* short/multiple packet check */
+	if (urb->actual_length < 2) {
+		dev_warn(&port->dev, "short packet received\n");
+		return -1;
+	}
+
+	opcode = buf[0];
+	len = buf[1];
+
+	if (urb->actual_length != len + 2) {
+		dev_err(&port->dev, "malformed packet received: port=%d, opcode=%d, len=%d, actual_length=%u\n",
+			priv->dp_port_num, opcode, len, urb->actual_length);
+		return -1;
+	}
+
+	if (opcode == DIGI_CMD_RECEIVE_DATA && len < 1) {
+		dev_err(&port->dev, "malformed data packet received\n");
+		return -1;
+	}
+
+	spin_lock_irqsave(&priv->dp_port_lock, flags);
+
+	/* check for throttle; if set, do not resubmit read urb */
+	/* indicate the read chain needs to be restarted on unthrottle */
+	throttled = priv->dp_throttled;
+	if (throttled)
+		priv->dp_throttle_restart = 1;
+
+	/* receive data */
+	if (opcode == DIGI_CMD_RECEIVE_DATA) {
+		port_status = buf[2];
+		data = &buf[3];
+
+		/* get flag from port_status */
+		tty_flag = 0;
+
+		/* overrun is special, not associated with a char */
+		if (port_status & DIGI_OVERRUN_ERROR)
+			tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
+
+		/* break takes precedence over parity, */
+		/* which takes precedence over framing errors */
+		if (port_status & DIGI_BREAK_ERROR)
+			tty_flag = TTY_BREAK;
+		else if (port_status & DIGI_PARITY_ERROR)
+			tty_flag = TTY_PARITY;
+		else if (port_status & DIGI_FRAMING_ERROR)
+			tty_flag = TTY_FRAME;
+
+		/* data length is len-1 (one byte of len is port_status) */
+		--len;
+		if (len > 0) {
+			tty_insert_flip_string_fixed_flag(&port->port, data,
+					tty_flag, len);
+			tty_flip_buffer_push(&port->port);
+		}
+	}
+	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+
+	if (opcode == DIGI_CMD_RECEIVE_DISABLE)
+		dev_dbg(&port->dev, "%s: got RECEIVE_DISABLE\n", __func__);
+	else if (opcode != DIGI_CMD_RECEIVE_DATA)
+		dev_dbg(&port->dev, "%s: unknown opcode: %d\n", __func__, opcode);
+
+	return throttled ? 1 : 0;
+
+}
+
+
+/*
+ *  Digi Read OOB Callback
+ *
+ *  Digi Read OOB Callback handles reads on the out of band port.
+ *  When called we know port and port->private are not NULL and
+ *  the port->serial is valid.  It returns 0 if successful, and
+ *  -1 if the sanity checks failed.
+ */
+
+static int digi_read_oob_callback(struct urb *urb)
+{
+
+	struct usb_serial_port *port = urb->context;
+	struct usb_serial *serial = port->serial;
+	struct tty_struct *tty;
+	struct digi_port *priv;
+	unsigned char *buf = urb->transfer_buffer;
+	int opcode, line, status, val;
+	unsigned long flags;
+	int i;
+	unsigned int rts;
+
+	if (urb->actual_length < 4)
+		return -1;
+
+	/* handle each oob command */
+	for (i = 0; i < urb->actual_length - 3; i += 4) {
+		opcode = buf[i];
+		line = buf[i + 1];
+		status = buf[i + 2];
+		val = buf[i + 3];
+
+		dev_dbg(&port->dev, "digi_read_oob_callback: opcode=%d, line=%d, status=%d, val=%d\n",
+			opcode, line, status, val);
+
+		if (status != 0 || line >= serial->type->num_ports)
+			continue;
+
+		port = serial->port[line];
+
+		priv = usb_get_serial_port_data(port);
+		if (priv == NULL)
+			return -1;
+
+		tty = tty_port_tty_get(&port->port);
+
+		rts = 0;
+		if (tty)
+			rts = C_CRTSCTS(tty);
+
+		if (tty && opcode == DIGI_CMD_READ_INPUT_SIGNALS) {
+			bool wakeup = false;
+
+			spin_lock_irqsave(&priv->dp_port_lock, flags);
+			/* convert from digi flags to termiox flags */
+			if (val & DIGI_READ_INPUT_SIGNALS_CTS) {
+				priv->dp_modem_signals |= TIOCM_CTS;
+				if (rts)
+					wakeup = true;
+			} else {
+				priv->dp_modem_signals &= ~TIOCM_CTS;
+				/* port must be open to use tty struct */
+			}
+			if (val & DIGI_READ_INPUT_SIGNALS_DSR)
+				priv->dp_modem_signals |= TIOCM_DSR;
+			else
+				priv->dp_modem_signals &= ~TIOCM_DSR;
+			if (val & DIGI_READ_INPUT_SIGNALS_RI)
+				priv->dp_modem_signals |= TIOCM_RI;
+			else
+				priv->dp_modem_signals &= ~TIOCM_RI;
+			if (val & DIGI_READ_INPUT_SIGNALS_DCD)
+				priv->dp_modem_signals |= TIOCM_CD;
+			else
+				priv->dp_modem_signals &= ~TIOCM_CD;
+
+			spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+
+			if (wakeup)
+				tty_port_tty_wakeup(&port->port);
+		} else if (opcode == DIGI_CMD_TRANSMIT_IDLE) {
+			spin_lock_irqsave(&priv->dp_port_lock, flags);
+			priv->dp_transmit_idle = 1;
+			wake_up_interruptible(&priv->dp_transmit_idle_wait);
+			spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+		} else if (opcode == DIGI_CMD_IFLUSH_FIFO) {
+			wake_up_interruptible(&priv->dp_flush_wait);
+		}
+		tty_kref_put(tty);
+	}
+	return 0;
+
+}
+
+module_usb_serial_driver(serial_drivers, id_table_combined);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");