Adding upstream version 6.1.76.upstream/6.1.76upstream

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

1 files changed, 1775 insertions, 0 deletions

diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
new file mode 100644
index 000000000..6b12bb464
--- /dev/null
+++ b/drivers/usb/serial/mos7840.c
@@ -0,0 +1,1775 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Clean ups from Moschip version and a few ioctl implementations by:
+ *	Paul B Schroeder <pschroeder "at" uplogix "dot" com>
+ *
+ * Originally based on drivers/usb/serial/io_edgeport.c which is:
+ *      Copyright (C) 2000 Inside Out Networks, All rights reserved.
+ *      Copyright (C) 2001-2002 Greg Kroah-Hartman <greg@kroah.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/serial.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+#include <linux/uaccess.h>
+
+#define DRIVER_DESC "Moschip 7840/7820 USB Serial Driver"
+
+/*
+ * 16C50 UART register defines
+ */
+
+#define LCR_BITS_5             0x00	/* 5 bits/char */
+#define LCR_BITS_6             0x01	/* 6 bits/char */
+#define LCR_BITS_7             0x02	/* 7 bits/char */
+#define LCR_BITS_8             0x03	/* 8 bits/char */
+#define LCR_BITS_MASK          0x03	/* Mask for bits/char field */
+
+#define LCR_STOP_1             0x00	/* 1 stop bit */
+#define LCR_STOP_1_5           0x04	/* 1.5 stop bits (if 5   bits/char) */
+#define LCR_STOP_2             0x04	/* 2 stop bits   (if 6-8 bits/char) */
+#define LCR_STOP_MASK          0x04	/* Mask for stop bits field */
+
+#define LCR_PAR_NONE           0x00	/* No parity */
+#define LCR_PAR_ODD            0x08	/* Odd parity */
+#define LCR_PAR_EVEN           0x18	/* Even parity */
+#define LCR_PAR_MARK           0x28	/* Force parity bit to 1 */
+#define LCR_PAR_SPACE          0x38	/* Force parity bit to 0 */
+#define LCR_PAR_MASK           0x38	/* Mask for parity field */
+
+#define LCR_SET_BREAK          0x40	/* Set Break condition */
+#define LCR_DL_ENABLE          0x80	/* Enable access to divisor latch */
+
+#define MCR_DTR                0x01	/* Assert DTR */
+#define MCR_RTS                0x02	/* Assert RTS */
+#define MCR_OUT1               0x04	/* Loopback only: Sets state of RI */
+#define MCR_MASTER_IE          0x08	/* Enable interrupt outputs */
+#define MCR_LOOPBACK           0x10	/* Set internal (digital) loopback mode */
+#define MCR_XON_ANY            0x20	/* Enable any char to exit XOFF mode */
+
+#define MOS7840_MSR_CTS        0x10	/* Current state of CTS */
+#define MOS7840_MSR_DSR        0x20	/* Current state of DSR */
+#define MOS7840_MSR_RI         0x40	/* Current state of RI */
+#define MOS7840_MSR_CD         0x80	/* Current state of CD */
+
+/*
+ * Defines used for sending commands to port
+ */
+
+#define MOS_WDR_TIMEOUT		5000	/* default urb timeout */
+
+#define MOS_PORT1       0x0200
+#define MOS_PORT2       0x0300
+#define MOS_VENREG      0x0000
+#define MOS_MAX_PORT	0x02
+#define MOS_WRITE       0x0E
+#define MOS_READ        0x0D
+
+/* Requests */
+#define MCS_RD_RTYPE    0xC0
+#define MCS_WR_RTYPE    0x40
+#define MCS_RDREQ       0x0D
+#define MCS_WRREQ       0x0E
+#define MCS_CTRL_TIMEOUT        500
+#define VENDOR_READ_LENGTH      (0x01)
+
+#define MAX_NAME_LEN    64
+
+#define ZLP_REG1  0x3A		/* Zero_Flag_Reg1    58 */
+#define ZLP_REG5  0x3E		/* Zero_Flag_Reg5    62 */
+
+/* For higher baud Rates use TIOCEXBAUD */
+#define TIOCEXBAUD     0x5462
+
+/*
+ * Vendor id and device id defines
+ *
+ * NOTE: Do not add new defines, add entries directly to the id_table instead.
+ */
+#define USB_VENDOR_ID_BANDB              0x0856
+#define BANDB_DEVICE_ID_USO9ML2_2        0xAC22
+#define BANDB_DEVICE_ID_USO9ML2_2P       0xBC00
+#define BANDB_DEVICE_ID_USO9ML2_4        0xAC24
+#define BANDB_DEVICE_ID_USO9ML2_4P       0xBC01
+#define BANDB_DEVICE_ID_US9ML2_2         0xAC29
+#define BANDB_DEVICE_ID_US9ML2_4         0xAC30
+#define BANDB_DEVICE_ID_USPTL4_2         0xAC31
+#define BANDB_DEVICE_ID_USPTL4_4         0xAC32
+#define BANDB_DEVICE_ID_USOPTL4_2        0xAC42
+#define BANDB_DEVICE_ID_USOPTL4_2P       0xBC02
+#define BANDB_DEVICE_ID_USOPTL4_4        0xAC44
+#define BANDB_DEVICE_ID_USOPTL4_4P       0xBC03
+
+/* Interrupt Routine Defines    */
+
+#define SERIAL_IIR_RLS      0x06
+#define SERIAL_IIR_MS       0x00
+
+/*
+ *  Emulation of the bit mask on the LINE STATUS REGISTER.
+ */
+#define SERIAL_LSR_DR       0x0001
+#define SERIAL_LSR_OE       0x0002
+#define SERIAL_LSR_PE       0x0004
+#define SERIAL_LSR_FE       0x0008
+#define SERIAL_LSR_BI       0x0010
+
+#define MOS_MSR_DELTA_CTS   0x10
+#define MOS_MSR_DELTA_DSR   0x20
+#define MOS_MSR_DELTA_RI    0x40
+#define MOS_MSR_DELTA_CD    0x80
+
+/* Serial Port register Address */
+#define INTERRUPT_ENABLE_REGISTER  ((__u16)(0x01))
+#define FIFO_CONTROL_REGISTER      ((__u16)(0x02))
+#define LINE_CONTROL_REGISTER      ((__u16)(0x03))
+#define MODEM_CONTROL_REGISTER     ((__u16)(0x04))
+#define LINE_STATUS_REGISTER       ((__u16)(0x05))
+#define MODEM_STATUS_REGISTER      ((__u16)(0x06))
+#define SCRATCH_PAD_REGISTER       ((__u16)(0x07))
+#define DIVISOR_LATCH_LSB          ((__u16)(0x00))
+#define DIVISOR_LATCH_MSB          ((__u16)(0x01))
+
+#define CLK_MULTI_REGISTER         ((__u16)(0x02))
+#define CLK_START_VALUE_REGISTER   ((__u16)(0x03))
+#define GPIO_REGISTER              ((__u16)(0x07))
+
+#define SERIAL_LCR_DLAB            ((__u16)(0x0080))
+
+/*
+ * URB POOL related defines
+ */
+#define NUM_URBS                        16	/* URB Count */
+#define URB_TRANSFER_BUFFER_SIZE        32	/* URB Size  */
+
+/* LED on/off milliseconds*/
+#define LED_ON_MS	500
+#define LED_OFF_MS	500
+
+enum mos7840_flag {
+	MOS7840_FLAG_LED_BUSY,
+};
+
+#define MCS_PORT_MASK	GENMASK(2, 0)
+#define MCS_PORTS(nr)	((nr) & MCS_PORT_MASK)
+#define MCS_LED		BIT(3)
+
+#define MCS_DEVICE(vid, pid, flags) \
+		USB_DEVICE((vid), (pid)), .driver_info = (flags)
+
+static const struct usb_device_id id_table[] = {
+	{ MCS_DEVICE(0x0557, 0x2011, MCS_PORTS(4)) },	/* ATEN UC2324 */
+	{ MCS_DEVICE(0x0557, 0x7820, MCS_PORTS(2)) },	/* ATEN UC2322 */
+	{ MCS_DEVICE(0x110a, 0x2210, MCS_PORTS(2)) },	/* Moxa UPort 2210 */
+	{ MCS_DEVICE(0x9710, 0x7810, MCS_PORTS(1) | MCS_LED) }, /* ASIX MCS7810 */
+	{ MCS_DEVICE(0x9710, 0x7820, MCS_PORTS(2)) },	/* MosChip MCS7820 */
+	{ MCS_DEVICE(0x9710, 0x7840, MCS_PORTS(4)) },	/* MosChip MCS7840 */
+	{ MCS_DEVICE(0x9710, 0x7843, MCS_PORTS(3)) },	/* ASIX MCS7840 3 port */
+	{ USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USO9ML2_2) },
+	{ USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USO9ML2_2P) },
+	{ USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USO9ML2_4) },
+	{ USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USO9ML2_4P) },
+	{ USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_US9ML2_2) },
+	{ USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_US9ML2_4) },
+	{ USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USPTL4_2) },
+	{ USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USPTL4_4) },
+	{ USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USOPTL4_2) },
+	{ USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USOPTL4_2P) },
+	{ USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USOPTL4_4) },
+	{ USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USOPTL4_4P) },
+	{}			/* terminating entry */
+};
+MODULE_DEVICE_TABLE(usb, id_table);
+
+/* This structure holds all of the local port information */
+
+struct moschip_port {
+	int port_num;		/*Actual port number in the device(1,2,etc) */
+	struct urb *read_urb;	/* read URB for this port */
+	__u8 shadowLCR;		/* last LCR value received */
+	__u8 shadowMCR;		/* last MCR value received */
+	struct usb_serial_port *port;	/* loop back to the owner of this object */
+
+	/* Offsets */
+	__u8 SpRegOffset;
+	__u8 ControlRegOffset;
+	__u8 DcrRegOffset;
+
+	spinlock_t pool_lock;
+	struct urb *write_urb_pool[NUM_URBS];
+	char busy[NUM_URBS];
+	bool read_urb_busy;
+
+	/* For device(s) with LED indicator */
+	bool has_led;
+	struct timer_list led_timer1;	/* Timer for LED on */
+	struct timer_list led_timer2;	/* Timer for LED off */
+	struct urb *led_urb;
+	struct usb_ctrlrequest *led_dr;
+
+	unsigned long flags;
+};
+
+/*
+ * mos7840_set_reg_sync
+ * 	To set the Control register by calling usb_fill_control_urb function
+ *	by passing usb_sndctrlpipe function as parameter.
+ */
+
+static int mos7840_set_reg_sync(struct usb_serial_port *port, __u16 reg,
+				__u16 val)
+{
+	struct usb_device *dev = port->serial->dev;
+	val = val & 0x00ff;
+	dev_dbg(&port->dev, "mos7840_set_reg_sync offset is %x, value %x\n", reg, val);
+
+	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), MCS_WRREQ,
+			       MCS_WR_RTYPE, val, reg, NULL, 0,
+			       MOS_WDR_TIMEOUT);
+}
+
+/*
+ * mos7840_get_reg_sync
+ * 	To set the Uart register by calling usb_fill_control_urb function by
+ *	passing usb_rcvctrlpipe function as parameter.
+ */
+
+static int mos7840_get_reg_sync(struct usb_serial_port *port, __u16 reg,
+				__u16 *val)
+{
+	struct usb_device *dev = port->serial->dev;
+	int ret = 0;
+	u8 *buf;
+
+	buf = kmalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), MCS_RDREQ,
+			      MCS_RD_RTYPE, 0, reg, buf, VENDOR_READ_LENGTH,
+			      MOS_WDR_TIMEOUT);
+	if (ret < VENDOR_READ_LENGTH) {
+		if (ret >= 0)
+			ret = -EIO;
+		goto out;
+	}
+
+	*val = buf[0];
+	dev_dbg(&port->dev, "%s offset is %x, return val %x\n", __func__, reg, *val);
+out:
+	kfree(buf);
+	return ret;
+}
+
+/*
+ * mos7840_set_uart_reg
+ *	To set the Uart register by calling usb_fill_control_urb function by
+ *	passing usb_sndctrlpipe function as parameter.
+ */
+
+static int mos7840_set_uart_reg(struct usb_serial_port *port, __u16 reg,
+				__u16 val)
+{
+
+	struct usb_device *dev = port->serial->dev;
+	val = val & 0x00ff;
+	/* For the UART control registers, the application number need
+	   to be Or'ed */
+	if (port->serial->num_ports == 2 && port->port_number != 0)
+		val |= ((__u16)port->port_number + 2) << 8;
+	else
+		val |= ((__u16)port->port_number + 1) << 8;
+	dev_dbg(&port->dev, "%s application number is %x\n", __func__, val);
+	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), MCS_WRREQ,
+			       MCS_WR_RTYPE, val, reg, NULL, 0,
+			       MOS_WDR_TIMEOUT);
+
+}
+
+/*
+ * mos7840_get_uart_reg
+ *	To set the Control register by calling usb_fill_control_urb function
+ *	by passing usb_rcvctrlpipe function as parameter.
+ */
+static int mos7840_get_uart_reg(struct usb_serial_port *port, __u16 reg,
+				__u16 *val)
+{
+	struct usb_device *dev = port->serial->dev;
+	int ret = 0;
+	__u16 Wval;
+	u8 *buf;
+
+	buf = kmalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Wval  is same as application number */
+	if (port->serial->num_ports == 2 && port->port_number != 0)
+		Wval = ((__u16)port->port_number + 2) << 8;
+	else
+		Wval = ((__u16)port->port_number + 1) << 8;
+	dev_dbg(&port->dev, "%s application number is %x\n", __func__, Wval);
+	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), MCS_RDREQ,
+			      MCS_RD_RTYPE, Wval, reg, buf, VENDOR_READ_LENGTH,
+			      MOS_WDR_TIMEOUT);
+	if (ret < VENDOR_READ_LENGTH) {
+		if (ret >= 0)
+			ret = -EIO;
+		goto out;
+	}
+	*val = buf[0];
+out:
+	kfree(buf);
+	return ret;
+}
+
+static void mos7840_dump_serial_port(struct usb_serial_port *port,
+				     struct moschip_port *mos7840_port)
+{
+
+	dev_dbg(&port->dev, "SpRegOffset is %2x\n", mos7840_port->SpRegOffset);
+	dev_dbg(&port->dev, "ControlRegOffset is %2x\n", mos7840_port->ControlRegOffset);
+	dev_dbg(&port->dev, "DCRRegOffset is %2x\n", mos7840_port->DcrRegOffset);
+
+}
+
+/************************************************************************/
+/************************************************************************/
+/*            U S B  C A L L B A C K   F U N C T I O N S                */
+/*            U S B  C A L L B A C K   F U N C T I O N S                */
+/************************************************************************/
+/************************************************************************/
+
+static void mos7840_set_led_callback(struct urb *urb)
+{
+	switch (urb->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: %d\n",
+			__func__, urb->status);
+		break;
+	default:
+		dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n",
+			__func__, urb->status);
+	}
+}
+
+static void mos7840_set_led_async(struct moschip_port *mcs, __u16 wval,
+				__u16 reg)
+{
+	struct usb_device *dev = mcs->port->serial->dev;
+	struct usb_ctrlrequest *dr = mcs->led_dr;
+
+	dr->bRequestType = MCS_WR_RTYPE;
+	dr->bRequest = MCS_WRREQ;
+	dr->wValue = cpu_to_le16(wval);
+	dr->wIndex = cpu_to_le16(reg);
+	dr->wLength = cpu_to_le16(0);
+
+	usb_fill_control_urb(mcs->led_urb, dev, usb_sndctrlpipe(dev, 0),
+		(unsigned char *)dr, NULL, 0, mos7840_set_led_callback, NULL);
+
+	usb_submit_urb(mcs->led_urb, GFP_ATOMIC);
+}
+
+static void mos7840_set_led_sync(struct usb_serial_port *port, __u16 reg,
+				__u16 val)
+{
+	struct usb_device *dev = port->serial->dev;
+
+	usb_control_msg(dev, usb_sndctrlpipe(dev, 0), MCS_WRREQ, MCS_WR_RTYPE,
+			val, reg, NULL, 0, MOS_WDR_TIMEOUT);
+}
+
+static void mos7840_led_off(struct timer_list *t)
+{
+	struct moschip_port *mcs = from_timer(mcs, t, led_timer1);
+
+	/* Turn off LED */
+	mos7840_set_led_async(mcs, 0x0300, MODEM_CONTROL_REGISTER);
+	mod_timer(&mcs->led_timer2,
+				jiffies + msecs_to_jiffies(LED_OFF_MS));
+}
+
+static void mos7840_led_flag_off(struct timer_list *t)
+{
+	struct moschip_port *mcs = from_timer(mcs, t, led_timer2);
+
+	clear_bit_unlock(MOS7840_FLAG_LED_BUSY, &mcs->flags);
+}
+
+static void mos7840_led_activity(struct usb_serial_port *port)
+{
+	struct moschip_port *mos7840_port = usb_get_serial_port_data(port);
+
+	if (test_and_set_bit_lock(MOS7840_FLAG_LED_BUSY, &mos7840_port->flags))
+		return;
+
+	mos7840_set_led_async(mos7840_port, 0x0301, MODEM_CONTROL_REGISTER);
+	mod_timer(&mos7840_port->led_timer1,
+				jiffies + msecs_to_jiffies(LED_ON_MS));
+}
+
+/*****************************************************************************
+ * mos7840_bulk_in_callback
+ *	this is the callback function for when we have received data on the
+ *	bulk in endpoint.
+ *****************************************************************************/
+
+static void mos7840_bulk_in_callback(struct urb *urb)
+{
+	struct moschip_port *mos7840_port = urb->context;
+	struct usb_serial_port *port = mos7840_port->port;
+	int retval;
+	unsigned char *data;
+	int status = urb->status;
+
+	if (status) {
+		dev_dbg(&urb->dev->dev, "nonzero read bulk status received: %d\n", status);
+		mos7840_port->read_urb_busy = false;
+		return;
+	}
+
+	data = urb->transfer_buffer;
+	usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
+
+	if (urb->actual_length) {
+		struct tty_port *tport = &mos7840_port->port->port;
+		tty_insert_flip_string(tport, data, urb->actual_length);
+		tty_flip_buffer_push(tport);
+		port->icount.rx += urb->actual_length;
+		dev_dbg(&port->dev, "icount.rx is %d:\n", port->icount.rx);
+	}
+
+	if (mos7840_port->has_led)
+		mos7840_led_activity(port);
+
+	mos7840_port->read_urb_busy = true;
+	retval = usb_submit_urb(mos7840_port->read_urb, GFP_ATOMIC);
+
+	if (retval) {
+		dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, retval = %d\n", retval);
+		mos7840_port->read_urb_busy = false;
+	}
+}
+
+/*****************************************************************************
+ * mos7840_bulk_out_data_callback
+ *	this is the callback function for when we have finished sending
+ *	serial data on the bulk out endpoint.
+ *****************************************************************************/
+
+static void mos7840_bulk_out_data_callback(struct urb *urb)
+{
+	struct moschip_port *mos7840_port = urb->context;
+	struct usb_serial_port *port = mos7840_port->port;
+	int status = urb->status;
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&mos7840_port->pool_lock, flags);
+	for (i = 0; i < NUM_URBS; i++) {
+		if (urb == mos7840_port->write_urb_pool[i]) {
+			mos7840_port->busy[i] = 0;
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);
+
+	if (status) {
+		dev_dbg(&port->dev, "nonzero write bulk status received:%d\n", status);
+		return;
+	}
+
+	tty_port_tty_wakeup(&port->port);
+
+}
+
+/************************************************************************/
+/*       D R I V E R  T T Y  I N T E R F A C E  F U N C T I O N S       */
+/************************************************************************/
+
+/*****************************************************************************
+ * mos7840_open
+ *	this function is called by the tty driver when a port is opened
+ *	If successful, we return 0
+ *	Otherwise we return a negative error number.
+ *****************************************************************************/
+
+static int mos7840_open(struct tty_struct *tty, struct usb_serial_port *port)
+{
+	struct moschip_port *mos7840_port = usb_get_serial_port_data(port);
+	struct usb_serial *serial = port->serial;
+	int response;
+	int j;
+	struct urb *urb;
+	__u16 Data;
+	int status;
+
+	usb_clear_halt(serial->dev, port->write_urb->pipe);
+	usb_clear_halt(serial->dev, port->read_urb->pipe);
+
+	/* Initialising the write urb pool */
+	for (j = 0; j < NUM_URBS; ++j) {
+		urb = usb_alloc_urb(0, GFP_KERNEL);
+		mos7840_port->write_urb_pool[j] = urb;
+		if (!urb)
+			continue;
+
+		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
+								GFP_KERNEL);
+		if (!urb->transfer_buffer) {
+			usb_free_urb(urb);
+			mos7840_port->write_urb_pool[j] = NULL;
+			continue;
+		}
+	}
+
+/*****************************************************************************
+ * Initialize MCS7840 -- Write Init values to corresponding Registers
+ *
+ * Register Index
+ * 1 : IER
+ * 2 : FCR
+ * 3 : LCR
+ * 4 : MCR
+ *
+ * 0x08 : SP1/2 Control Reg
+ *****************************************************************************/
+
+	/* NEED to check the following Block */
+
+	Data = 0x0;
+	status = mos7840_get_reg_sync(port, mos7840_port->SpRegOffset, &Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "Reading Spreg failed\n");
+		goto err;
+	}
+	Data |= 0x80;
+	status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "writing Spreg failed\n");
+		goto err;
+	}
+
+	Data &= ~0x80;
+	status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "writing Spreg failed\n");
+		goto err;
+	}
+	/* End of block to be checked */
+
+	Data = 0x0;
+	status = mos7840_get_reg_sync(port, mos7840_port->ControlRegOffset,
+									&Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "Reading Controlreg failed\n");
+		goto err;
+	}
+	Data |= 0x08;		/* Driver done bit */
+	Data |= 0x20;		/* rx_disable */
+	status = mos7840_set_reg_sync(port,
+				mos7840_port->ControlRegOffset, Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "writing Controlreg failed\n");
+		goto err;
+	}
+	/* do register settings here */
+	/* Set all regs to the device default values. */
+	/***********************************
+	 * First Disable all interrupts.
+	 ***********************************/
+	Data = 0x00;
+	status = mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "disabling interrupts failed\n");
+		goto err;
+	}
+	/* Set FIFO_CONTROL_REGISTER to the default value */
+	Data = 0x00;
+	status = mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "Writing FIFO_CONTROL_REGISTER  failed\n");
+		goto err;
+	}
+
+	Data = 0xcf;
+	status = mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "Writing FIFO_CONTROL_REGISTER  failed\n");
+		goto err;
+	}
+
+	Data = 0x03;
+	status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
+	mos7840_port->shadowLCR = Data;
+
+	Data = 0x0b;
+	status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+	mos7840_port->shadowMCR = Data;
+
+	Data = 0x00;
+	status = mos7840_get_uart_reg(port, LINE_CONTROL_REGISTER, &Data);
+	mos7840_port->shadowLCR = Data;
+
+	Data |= SERIAL_LCR_DLAB;	/* data latch enable in LCR 0x80 */
+	status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
+
+	Data = 0x0c;
+	status = mos7840_set_uart_reg(port, DIVISOR_LATCH_LSB, Data);
+
+	Data = 0x0;
+	status = mos7840_set_uart_reg(port, DIVISOR_LATCH_MSB, Data);
+
+	Data = 0x00;
+	status = mos7840_get_uart_reg(port, LINE_CONTROL_REGISTER, &Data);
+
+	Data = Data & ~SERIAL_LCR_DLAB;
+	status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
+	mos7840_port->shadowLCR = Data;
+
+	/* clearing Bulkin and Bulkout Fifo */
+	Data = 0x0;
+	status = mos7840_get_reg_sync(port, mos7840_port->SpRegOffset, &Data);
+
+	Data = Data | 0x0c;
+	status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
+
+	Data = Data & ~0x0c;
+	status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
+	/* Finally enable all interrupts */
+	Data = 0x0c;
+	status = mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
+
+	/* clearing rx_disable */
+	Data = 0x0;
+	status = mos7840_get_reg_sync(port, mos7840_port->ControlRegOffset,
+									&Data);
+	Data = Data & ~0x20;
+	status = mos7840_set_reg_sync(port, mos7840_port->ControlRegOffset,
+									Data);
+
+	/* rx_negate */
+	Data = 0x0;
+	status = mos7840_get_reg_sync(port, mos7840_port->ControlRegOffset,
+									&Data);
+	Data = Data | 0x10;
+	status = mos7840_set_reg_sync(port, mos7840_port->ControlRegOffset,
+									Data);
+
+	dev_dbg(&port->dev, "port number is %d\n", port->port_number);
+	dev_dbg(&port->dev, "minor number is %d\n", port->minor);
+	dev_dbg(&port->dev, "Bulkin endpoint is %d\n", port->bulk_in_endpointAddress);
+	dev_dbg(&port->dev, "BulkOut endpoint is %d\n", port->bulk_out_endpointAddress);
+	dev_dbg(&port->dev, "Interrupt endpoint is %d\n", port->interrupt_in_endpointAddress);
+	dev_dbg(&port->dev, "port's number in the device is %d\n", mos7840_port->port_num);
+	mos7840_port->read_urb = port->read_urb;
+
+	/* set up our bulk in urb */
+	if ((serial->num_ports == 2) && (((__u16)port->port_number % 2) != 0)) {
+		usb_fill_bulk_urb(mos7840_port->read_urb,
+			serial->dev,
+			usb_rcvbulkpipe(serial->dev,
+				(port->bulk_in_endpointAddress) + 2),
+			port->bulk_in_buffer,
+			mos7840_port->read_urb->transfer_buffer_length,
+			mos7840_bulk_in_callback, mos7840_port);
+	} else {
+		usb_fill_bulk_urb(mos7840_port->read_urb,
+			serial->dev,
+			usb_rcvbulkpipe(serial->dev,
+				port->bulk_in_endpointAddress),
+			port->bulk_in_buffer,
+			mos7840_port->read_urb->transfer_buffer_length,
+			mos7840_bulk_in_callback, mos7840_port);
+	}
+
+	dev_dbg(&port->dev, "%s: bulkin endpoint is %d\n", __func__, port->bulk_in_endpointAddress);
+	mos7840_port->read_urb_busy = true;
+	response = usb_submit_urb(mos7840_port->read_urb, GFP_KERNEL);
+	if (response) {
+		dev_err(&port->dev, "%s - Error %d submitting control urb\n",
+			__func__, response);
+		mos7840_port->read_urb_busy = false;
+	}
+
+	/* initialize our port settings */
+	/* Must set to enable ints! */
+	mos7840_port->shadowMCR = MCR_MASTER_IE;
+
+	return 0;
+err:
+	for (j = 0; j < NUM_URBS; ++j) {
+		urb = mos7840_port->write_urb_pool[j];
+		if (!urb)
+			continue;
+		kfree(urb->transfer_buffer);
+		usb_free_urb(urb);
+	}
+	return status;
+}
+
+/*****************************************************************************
+ * mos7840_chars_in_buffer
+ *	this function is called by the tty driver when it wants to know how many
+ *	bytes of data we currently have outstanding in the port (data that has
+ *	been written, but hasn't made it out the port yet)
+ *****************************************************************************/
+
+static unsigned int mos7840_chars_in_buffer(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct moschip_port *mos7840_port = usb_get_serial_port_data(port);
+	int i;
+	unsigned int chars = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&mos7840_port->pool_lock, flags);
+	for (i = 0; i < NUM_URBS; ++i) {
+		if (mos7840_port->busy[i]) {
+			struct urb *urb = mos7840_port->write_urb_pool[i];
+			chars += urb->transfer_buffer_length;
+		}
+	}
+	spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);
+	dev_dbg(&port->dev, "%s - returns %u\n", __func__, chars);
+	return chars;
+
+}
+
+/*****************************************************************************
+ * mos7840_close
+ *	this function is called by the tty driver when a port is closed
+ *****************************************************************************/
+
+static void mos7840_close(struct usb_serial_port *port)
+{
+	struct moschip_port *mos7840_port = usb_get_serial_port_data(port);
+	int j;
+	__u16 Data;
+
+	for (j = 0; j < NUM_URBS; ++j)
+		usb_kill_urb(mos7840_port->write_urb_pool[j]);
+
+	/* Freeing Write URBs */
+	for (j = 0; j < NUM_URBS; ++j) {
+		if (mos7840_port->write_urb_pool[j]) {
+			kfree(mos7840_port->write_urb_pool[j]->transfer_buffer);
+			usb_free_urb(mos7840_port->write_urb_pool[j]);
+		}
+	}
+
+	usb_kill_urb(mos7840_port->read_urb);
+	mos7840_port->read_urb_busy = false;
+
+	Data = 0x0;
+	mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+
+	Data = 0x00;
+	mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
+}
+
+/*****************************************************************************
+ * mos7840_break
+ *	this function sends a break to the port
+ *****************************************************************************/
+static void mos7840_break(struct tty_struct *tty, int break_state)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct moschip_port *mos7840_port = usb_get_serial_port_data(port);
+	unsigned char data;
+
+	if (break_state == -1)
+		data = mos7840_port->shadowLCR | LCR_SET_BREAK;
+	else
+		data = mos7840_port->shadowLCR & ~LCR_SET_BREAK;
+
+	/* FIXME: no locking on shadowLCR anywhere in driver */
+	mos7840_port->shadowLCR = data;
+	dev_dbg(&port->dev, "%s mos7840_port->shadowLCR is %x\n", __func__, mos7840_port->shadowLCR);
+	mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER,
+			     mos7840_port->shadowLCR);
+}
+
+/*****************************************************************************
+ * mos7840_write_room
+ *	this function is called by the tty driver when it wants to know how many
+ *	bytes of data we can accept for a specific port.
+ *****************************************************************************/
+
+static unsigned int mos7840_write_room(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct moschip_port *mos7840_port = usb_get_serial_port_data(port);
+	int i;
+	unsigned int room = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&mos7840_port->pool_lock, flags);
+	for (i = 0; i < NUM_URBS; ++i) {
+		if (!mos7840_port->busy[i])
+			room += URB_TRANSFER_BUFFER_SIZE;
+	}
+	spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);
+
+	room = (room == 0) ? 0 : room - URB_TRANSFER_BUFFER_SIZE + 1;
+	dev_dbg(&mos7840_port->port->dev, "%s - returns %u\n", __func__, room);
+	return room;
+
+}
+
+/*****************************************************************************
+ * mos7840_write
+ *	this function is called by the tty driver when data should be written to
+ *	the port.
+ *	If successful, we return the number of bytes written, otherwise we
+ *      return a negative error number.
+ *****************************************************************************/
+
+static int mos7840_write(struct tty_struct *tty, struct usb_serial_port *port,
+			 const unsigned char *data, int count)
+{
+	struct moschip_port *mos7840_port = usb_get_serial_port_data(port);
+	struct usb_serial *serial = port->serial;
+	int status;
+	int i;
+	int bytes_sent = 0;
+	int transfer_size;
+	unsigned long flags;
+	struct urb *urb;
+	/* __u16 Data; */
+	const unsigned char *current_position = data;
+
+	/* try to find a free urb in the list */
+	urb = NULL;
+
+	spin_lock_irqsave(&mos7840_port->pool_lock, flags);
+	for (i = 0; i < NUM_URBS; ++i) {
+		if (!mos7840_port->busy[i]) {
+			mos7840_port->busy[i] = 1;
+			urb = mos7840_port->write_urb_pool[i];
+			dev_dbg(&port->dev, "URB:%d\n", i);
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);
+
+	if (urb == NULL) {
+		dev_dbg(&port->dev, "%s - no more free urbs\n", __func__);
+		goto exit;
+	}
+
+	if (urb->transfer_buffer == NULL) {
+		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
+					       GFP_ATOMIC);
+		if (!urb->transfer_buffer) {
+			bytes_sent = -ENOMEM;
+			goto exit;
+		}
+	}
+	transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
+
+	memcpy(urb->transfer_buffer, current_position, transfer_size);
+
+	/* fill urb with data and submit  */
+	if ((serial->num_ports == 2) && (((__u16)port->port_number % 2) != 0)) {
+		usb_fill_bulk_urb(urb,
+			serial->dev,
+			usb_sndbulkpipe(serial->dev,
+				(port->bulk_out_endpointAddress) + 2),
+			urb->transfer_buffer,
+			transfer_size,
+			mos7840_bulk_out_data_callback, mos7840_port);
+	} else {
+		usb_fill_bulk_urb(urb,
+			serial->dev,
+			usb_sndbulkpipe(serial->dev,
+				port->bulk_out_endpointAddress),
+			urb->transfer_buffer,
+			transfer_size,
+			mos7840_bulk_out_data_callback, mos7840_port);
+	}
+
+	dev_dbg(&port->dev, "bulkout endpoint is %d\n", port->bulk_out_endpointAddress);
+
+	if (mos7840_port->has_led)
+		mos7840_led_activity(port);
+
+	/* send it down the pipe */
+	status = usb_submit_urb(urb, GFP_ATOMIC);
+
+	if (status) {
+		mos7840_port->busy[i] = 0;
+		dev_err_console(port, "%s - usb_submit_urb(write bulk) failed "
+			"with status = %d\n", __func__, status);
+		bytes_sent = status;
+		goto exit;
+	}
+	bytes_sent = transfer_size;
+	port->icount.tx += transfer_size;
+	dev_dbg(&port->dev, "icount.tx is %d:\n", port->icount.tx);
+exit:
+	return bytes_sent;
+
+}
+
+/*****************************************************************************
+ * mos7840_throttle
+ *	this function is called by the tty driver when it wants to stop the data
+ *	being read from the port.
+ *****************************************************************************/
+
+static void mos7840_throttle(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct moschip_port *mos7840_port = usb_get_serial_port_data(port);
+	int status;
+
+	/* if we are implementing XON/XOFF, send the stop character */
+	if (I_IXOFF(tty)) {
+		unsigned char stop_char = STOP_CHAR(tty);
+		status = mos7840_write(tty, port, &stop_char, 1);
+		if (status <= 0)
+			return;
+	}
+	/* if we are implementing RTS/CTS, toggle that line */
+	if (C_CRTSCTS(tty)) {
+		mos7840_port->shadowMCR &= ~MCR_RTS;
+		status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER,
+					 mos7840_port->shadowMCR);
+		if (status < 0)
+			return;
+	}
+}
+
+/*****************************************************************************
+ * mos7840_unthrottle
+ *	this function is called by the tty driver when it wants to resume
+ *	the data being read from the port (called after mos7840_throttle is
+ *	called)
+ *****************************************************************************/
+static void mos7840_unthrottle(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct moschip_port *mos7840_port = usb_get_serial_port_data(port);
+	int status;
+
+	/* if we are implementing XON/XOFF, send the start character */
+	if (I_IXOFF(tty)) {
+		unsigned char start_char = START_CHAR(tty);
+		status = mos7840_write(tty, port, &start_char, 1);
+		if (status <= 0)
+			return;
+	}
+
+	/* if we are implementing RTS/CTS, toggle that line */
+	if (C_CRTSCTS(tty)) {
+		mos7840_port->shadowMCR |= MCR_RTS;
+		status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER,
+					 mos7840_port->shadowMCR);
+		if (status < 0)
+			return;
+	}
+}
+
+static int mos7840_tiocmget(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	unsigned int result;
+	__u16 msr;
+	__u16 mcr;
+	int status;
+
+	status = mos7840_get_uart_reg(port, MODEM_STATUS_REGISTER, &msr);
+	if (status < 0)
+		return -EIO;
+	status = mos7840_get_uart_reg(port, MODEM_CONTROL_REGISTER, &mcr);
+	if (status < 0)
+		return -EIO;
+	result = ((mcr & MCR_DTR) ? TIOCM_DTR : 0)
+	    | ((mcr & MCR_RTS) ? TIOCM_RTS : 0)
+	    | ((mcr & MCR_LOOPBACK) ? TIOCM_LOOP : 0)
+	    | ((msr & MOS7840_MSR_CTS) ? TIOCM_CTS : 0)
+	    | ((msr & MOS7840_MSR_CD) ? TIOCM_CAR : 0)
+	    | ((msr & MOS7840_MSR_RI) ? TIOCM_RI : 0)
+	    | ((msr & MOS7840_MSR_DSR) ? TIOCM_DSR : 0);
+
+	dev_dbg(&port->dev, "%s - 0x%04X\n", __func__, result);
+
+	return result;
+}
+
+static int mos7840_tiocmset(struct tty_struct *tty,
+			    unsigned int set, unsigned int clear)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct moschip_port *mos7840_port = usb_get_serial_port_data(port);
+	unsigned int mcr;
+	int status;
+
+	/* FIXME: What locks the port registers ? */
+	mcr = mos7840_port->shadowMCR;
+	if (clear & TIOCM_RTS)
+		mcr &= ~MCR_RTS;
+	if (clear & TIOCM_DTR)
+		mcr &= ~MCR_DTR;
+	if (clear & TIOCM_LOOP)
+		mcr &= ~MCR_LOOPBACK;
+
+	if (set & TIOCM_RTS)
+		mcr |= MCR_RTS;
+	if (set & TIOCM_DTR)
+		mcr |= MCR_DTR;
+	if (set & TIOCM_LOOP)
+		mcr |= MCR_LOOPBACK;
+
+	mos7840_port->shadowMCR = mcr;
+
+	status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, mcr);
+	if (status < 0) {
+		dev_dbg(&port->dev, "setting MODEM_CONTROL_REGISTER Failed\n");
+		return status;
+	}
+
+	return 0;
+}
+
+/*****************************************************************************
+ * mos7840_calc_baud_rate_divisor
+ *	this function calculates the proper baud rate divisor for the specified
+ *	baud rate.
+ *****************************************************************************/
+static int mos7840_calc_baud_rate_divisor(struct usb_serial_port *port,
+					  int baudRate, int *divisor,
+					  __u16 *clk_sel_val)
+{
+	dev_dbg(&port->dev, "%s - %d\n", __func__, baudRate);
+
+	if (baudRate <= 115200) {
+		*divisor = 115200 / baudRate;
+		*clk_sel_val = 0x0;
+	}
+	if ((baudRate > 115200) && (baudRate <= 230400)) {
+		*divisor = 230400 / baudRate;
+		*clk_sel_val = 0x10;
+	} else if ((baudRate > 230400) && (baudRate <= 403200)) {
+		*divisor = 403200 / baudRate;
+		*clk_sel_val = 0x20;
+	} else if ((baudRate > 403200) && (baudRate <= 460800)) {
+		*divisor = 460800 / baudRate;
+		*clk_sel_val = 0x30;
+	} else if ((baudRate > 460800) && (baudRate <= 806400)) {
+		*divisor = 806400 / baudRate;
+		*clk_sel_val = 0x40;
+	} else if ((baudRate > 806400) && (baudRate <= 921600)) {
+		*divisor = 921600 / baudRate;
+		*clk_sel_val = 0x50;
+	} else if ((baudRate > 921600) && (baudRate <= 1572864)) {
+		*divisor = 1572864 / baudRate;
+		*clk_sel_val = 0x60;
+	} else if ((baudRate > 1572864) && (baudRate <= 3145728)) {
+		*divisor = 3145728 / baudRate;
+		*clk_sel_val = 0x70;
+	}
+	return 0;
+}
+
+/*****************************************************************************
+ * mos7840_send_cmd_write_baud_rate
+ *	this function sends the proper command to change the baud rate of the
+ *	specified port.
+ *****************************************************************************/
+
+static int mos7840_send_cmd_write_baud_rate(struct moschip_port *mos7840_port,
+					    int baudRate)
+{
+	struct usb_serial_port *port = mos7840_port->port;
+	int divisor = 0;
+	int status;
+	__u16 Data;
+	__u16 clk_sel_val;
+
+	dev_dbg(&port->dev, "%s - baud = %d\n", __func__, baudRate);
+	/* reset clk_uart_sel in spregOffset */
+	if (baudRate > 115200) {
+#ifdef HW_flow_control
+		/* NOTE: need to see the pther register to modify */
+		/* setting h/w flow control bit to 1 */
+		Data = 0x2b;
+		mos7840_port->shadowMCR = Data;
+		status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER,
+									Data);
+		if (status < 0) {
+			dev_dbg(&port->dev, "Writing spreg failed in set_serial_baud\n");
+			return -1;
+		}
+#endif
+
+	} else {
+#ifdef HW_flow_control
+		/* setting h/w flow control bit to 0 */
+		Data = 0xb;
+		mos7840_port->shadowMCR = Data;
+		status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER,
+									Data);
+		if (status < 0) {
+			dev_dbg(&port->dev, "Writing spreg failed in set_serial_baud\n");
+			return -1;
+		}
+#endif
+
+	}
+
+	if (1) {		/* baudRate <= 115200) */
+		clk_sel_val = 0x0;
+		Data = 0x0;
+		status = mos7840_calc_baud_rate_divisor(port, baudRate, &divisor,
+						   &clk_sel_val);
+		status = mos7840_get_reg_sync(port, mos7840_port->SpRegOffset,
+								 &Data);
+		if (status < 0) {
+			dev_dbg(&port->dev, "reading spreg failed in set_serial_baud\n");
+			return -1;
+		}
+		Data = (Data & 0x8f) | clk_sel_val;
+		status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset,
+								Data);
+		if (status < 0) {
+			dev_dbg(&port->dev, "Writing spreg failed in set_serial_baud\n");
+			return -1;
+		}
+		/* Calculate the Divisor */
+
+		if (status) {
+			dev_err(&port->dev, "%s - bad baud rate\n", __func__);
+			return status;
+		}
+		/* Enable access to divisor latch */
+		Data = mos7840_port->shadowLCR | SERIAL_LCR_DLAB;
+		mos7840_port->shadowLCR = Data;
+		mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
+
+		/* Write the divisor */
+		Data = (unsigned char)(divisor & 0xff);
+		dev_dbg(&port->dev, "set_serial_baud Value to write DLL is %x\n", Data);
+		mos7840_set_uart_reg(port, DIVISOR_LATCH_LSB, Data);
+
+		Data = (unsigned char)((divisor & 0xff00) >> 8);
+		dev_dbg(&port->dev, "set_serial_baud Value to write DLM is %x\n", Data);
+		mos7840_set_uart_reg(port, DIVISOR_LATCH_MSB, Data);
+
+		/* Disable access to divisor latch */
+		Data = mos7840_port->shadowLCR & ~SERIAL_LCR_DLAB;
+		mos7840_port->shadowLCR = Data;
+		mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
+
+	}
+	return status;
+}
+
+/*****************************************************************************
+ * mos7840_change_port_settings
+ *	This routine is called to set the UART on the device to match
+ *      the specified new settings.
+ *****************************************************************************/
+
+static void mos7840_change_port_settings(struct tty_struct *tty,
+					 struct moschip_port *mos7840_port,
+					 const struct ktermios *old_termios)
+{
+	struct usb_serial_port *port = mos7840_port->port;
+	int baud;
+	unsigned cflag;
+	__u8 lData;
+	__u8 lParity;
+	__u8 lStop;
+	int status;
+	__u16 Data;
+
+	lData = LCR_BITS_8;
+	lStop = LCR_STOP_1;
+	lParity = LCR_PAR_NONE;
+
+	cflag = tty->termios.c_cflag;
+
+	/* Change the number of bits */
+	switch (cflag & CSIZE) {
+	case CS5:
+		lData = LCR_BITS_5;
+		break;
+
+	case CS6:
+		lData = LCR_BITS_6;
+		break;
+
+	case CS7:
+		lData = LCR_BITS_7;
+		break;
+
+	default:
+	case CS8:
+		lData = LCR_BITS_8;
+		break;
+	}
+
+	/* Change the Parity bit */
+	if (cflag & PARENB) {
+		if (cflag & PARODD) {
+			lParity = LCR_PAR_ODD;
+			dev_dbg(&port->dev, "%s - parity = odd\n", __func__);
+		} else {
+			lParity = LCR_PAR_EVEN;
+			dev_dbg(&port->dev, "%s - parity = even\n", __func__);
+		}
+
+	} else {
+		dev_dbg(&port->dev, "%s - parity = none\n", __func__);
+	}
+
+	if (cflag & CMSPAR)
+		lParity = lParity | 0x20;
+
+	/* Change the Stop bit */
+	if (cflag & CSTOPB) {
+		lStop = LCR_STOP_2;
+		dev_dbg(&port->dev, "%s - stop bits = 2\n", __func__);
+	} else {
+		lStop = LCR_STOP_1;
+		dev_dbg(&port->dev, "%s - stop bits = 1\n", __func__);
+	}
+
+	/* Update the LCR with the correct value */
+	mos7840_port->shadowLCR &=
+	    ~(LCR_BITS_MASK | LCR_STOP_MASK | LCR_PAR_MASK);
+	mos7840_port->shadowLCR |= (lData | lParity | lStop);
+
+	dev_dbg(&port->dev, "%s - mos7840_port->shadowLCR is %x\n", __func__,
+		mos7840_port->shadowLCR);
+	/* Disable Interrupts */
+	Data = 0x00;
+	mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
+
+	Data = 0x00;
+	mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);
+
+	Data = 0xcf;
+	mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);
+
+	/* Send the updated LCR value to the mos7840 */
+	Data = mos7840_port->shadowLCR;
+
+	mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
+
+	Data = 0x00b;
+	mos7840_port->shadowMCR = Data;
+	mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+	Data = 0x00b;
+	mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+
+	/* set up the MCR register and send it to the mos7840 */
+
+	mos7840_port->shadowMCR = MCR_MASTER_IE;
+	if (cflag & CBAUD)
+		mos7840_port->shadowMCR |= (MCR_DTR | MCR_RTS);
+
+	if (cflag & CRTSCTS)
+		mos7840_port->shadowMCR |= (MCR_XON_ANY);
+	else
+		mos7840_port->shadowMCR &= ~(MCR_XON_ANY);
+
+	Data = mos7840_port->shadowMCR;
+	mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+
+	/* Determine divisor based on baud rate */
+	baud = tty_get_baud_rate(tty);
+
+	if (!baud) {
+		/* pick a default, any default... */
+		dev_dbg(&port->dev, "%s", "Picked default baud...\n");
+		baud = 9600;
+	}
+
+	dev_dbg(&port->dev, "%s - baud rate = %d\n", __func__, baud);
+	status = mos7840_send_cmd_write_baud_rate(mos7840_port, baud);
+
+	/* Enable Interrupts */
+	Data = 0x0c;
+	mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
+
+	if (!mos7840_port->read_urb_busy) {
+		mos7840_port->read_urb_busy = true;
+		status = usb_submit_urb(mos7840_port->read_urb, GFP_KERNEL);
+		if (status) {
+			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, status = %d\n",
+			    status);
+			mos7840_port->read_urb_busy = false;
+		}
+	}
+	dev_dbg(&port->dev, "%s - mos7840_port->shadowLCR is End %x\n", __func__,
+		mos7840_port->shadowLCR);
+}
+
+/*****************************************************************************
+ * mos7840_set_termios
+ *	this function is called by the tty driver when it wants to change
+ *	the termios structure
+ *****************************************************************************/
+
+static void mos7840_set_termios(struct tty_struct *tty,
+				struct usb_serial_port *port,
+				const struct ktermios *old_termios)
+{
+	struct moschip_port *mos7840_port = usb_get_serial_port_data(port);
+	int status;
+
+	/* change the port settings to the new ones specified */
+
+	mos7840_change_port_settings(tty, mos7840_port, old_termios);
+
+	if (!mos7840_port->read_urb_busy) {
+		mos7840_port->read_urb_busy = true;
+		status = usb_submit_urb(mos7840_port->read_urb, GFP_KERNEL);
+		if (status) {
+			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, status = %d\n",
+			    status);
+			mos7840_port->read_urb_busy = false;
+		}
+	}
+}
+
+/*****************************************************************************
+ * mos7840_get_lsr_info - get line status register info
+ *
+ * Purpose: Let user call ioctl() to get info when the UART physically
+ * 	    is emptied.  On bus types like RS485, the transmitter must
+ * 	    release the bus after transmitting. This must be done when
+ * 	    the transmit shift register is empty, not be done when the
+ * 	    transmit holding register is empty.  This functionality
+ * 	    allows an RS485 driver to be written in user space.
+ *****************************************************************************/
+
+static int mos7840_get_lsr_info(struct tty_struct *tty,
+				unsigned int __user *value)
+{
+	int count;
+	unsigned int result = 0;
+
+	count = mos7840_chars_in_buffer(tty);
+	if (count == 0)
+		result = TIOCSER_TEMT;
+
+	if (copy_to_user(value, &result, sizeof(int)))
+		return -EFAULT;
+	return 0;
+}
+
+/*****************************************************************************
+ * SerialIoctl
+ *	this function handles any ioctl calls to the driver
+ *****************************************************************************/
+
+static int mos7840_ioctl(struct tty_struct *tty,
+			 unsigned int cmd, unsigned long arg)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	void __user *argp = (void __user *)arg;
+
+	switch (cmd) {
+		/* return number of bytes available */
+
+	case TIOCSERGETLSR:
+		dev_dbg(&port->dev, "%s TIOCSERGETLSR\n", __func__);
+		return mos7840_get_lsr_info(tty, argp);
+
+	default:
+		break;
+	}
+	return -ENOIOCTLCMD;
+}
+
+/*
+ * Check if GPO (pin 42) is connected to GPI (pin 33) as recommended by ASIX
+ * for MCS7810 by bit-banging a 16-bit word.
+ *
+ * Note that GPO is really RTS of the third port so this will toggle RTS of
+ * port two or three on two- and four-port devices.
+ */
+static int mos7810_check(struct usb_serial *serial)
+{
+	int i, pass_count = 0;
+	u8 *buf;
+	__u16 data = 0, mcr_data = 0;
+	__u16 test_pattern = 0x55AA;
+	int res;
+
+	buf = kmalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
+	if (!buf)
+		return 0;	/* failed to identify 7810 */
+
+	/* Store MCR setting */
+	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+		MCS_RDREQ, MCS_RD_RTYPE, 0x0300, MODEM_CONTROL_REGISTER,
+		buf, VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+	if (res == VENDOR_READ_LENGTH)
+		mcr_data = *buf;
+
+	for (i = 0; i < 16; i++) {
+		/* Send the 1-bit test pattern out to MCS7810 test pin */
+		usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+			MCS_WRREQ, MCS_WR_RTYPE,
+			(0x0300 | (((test_pattern >> i) & 0x0001) << 1)),
+			MODEM_CONTROL_REGISTER, NULL, 0, MOS_WDR_TIMEOUT);
+
+		/* Read the test pattern back */
+		res = usb_control_msg(serial->dev,
+				usb_rcvctrlpipe(serial->dev, 0), MCS_RDREQ,
+				MCS_RD_RTYPE, 0, GPIO_REGISTER, buf,
+				VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+		if (res == VENDOR_READ_LENGTH)
+			data = *buf;
+
+		/* If this is a MCS7810 device, both test patterns must match */
+		if (((test_pattern >> i) ^ (~data >> 1)) & 0x0001)
+			break;
+
+		pass_count++;
+	}
+
+	/* Restore MCR setting */
+	usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), MCS_WRREQ,
+		MCS_WR_RTYPE, 0x0300 | mcr_data, MODEM_CONTROL_REGISTER, NULL,
+		0, MOS_WDR_TIMEOUT);
+
+	kfree(buf);
+
+	if (pass_count == 16)
+		return 1;
+
+	return 0;
+}
+
+static int mos7840_probe(struct usb_serial *serial,
+				const struct usb_device_id *id)
+{
+	unsigned long device_flags = id->driver_info;
+	u8 *buf;
+
+	/* Skip device-type detection if we already have device flags. */
+	if (device_flags)
+		goto out;
+
+	buf = kzalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+			MCS_RDREQ, MCS_RD_RTYPE, 0, GPIO_REGISTER, buf,
+			VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+
+	/* For a MCS7840 device GPIO0 must be set to 1 */
+	if (buf[0] & 0x01)
+		device_flags = MCS_PORTS(4);
+	else if (mos7810_check(serial))
+		device_flags = MCS_PORTS(1) | MCS_LED;
+	else
+		device_flags = MCS_PORTS(2);
+
+	kfree(buf);
+out:
+	usb_set_serial_data(serial, (void *)device_flags);
+
+	return 0;
+}
+
+static int mos7840_calc_num_ports(struct usb_serial *serial,
+					struct usb_serial_endpoints *epds)
+{
+	unsigned long device_flags = (unsigned long)usb_get_serial_data(serial);
+	int num_ports = MCS_PORTS(device_flags);
+
+	if (num_ports == 0 || num_ports > 4)
+		return -ENODEV;
+
+	if (epds->num_bulk_in < num_ports || epds->num_bulk_out < num_ports) {
+		dev_err(&serial->interface->dev, "missing endpoints\n");
+		return -ENODEV;
+	}
+
+	return num_ports;
+}
+
+static int mos7840_attach(struct usb_serial *serial)
+{
+	struct device *dev = &serial->interface->dev;
+	int status;
+	u16 val;
+
+	/* Zero Length flag enable */
+	val = 0x0f;
+	status = mos7840_set_reg_sync(serial->port[0], ZLP_REG5, val);
+	if (status < 0)
+		dev_dbg(dev, "Writing ZLP_REG5 failed status-0x%x\n", status);
+	else
+		dev_dbg(dev, "ZLP_REG5 Writing success status%d\n", status);
+
+	return status;
+}
+
+static int mos7840_port_probe(struct usb_serial_port *port)
+{
+	struct usb_serial *serial = port->serial;
+	unsigned long device_flags = (unsigned long)usb_get_serial_data(serial);
+	struct moschip_port *mos7840_port;
+	int status;
+	int pnum;
+	__u16 Data;
+
+	/* we set up the pointers to the endpoints in the mos7840_open *
+	 * function, as the structures aren't created yet.             */
+
+	pnum = port->port_number;
+
+	dev_dbg(&port->dev, "mos7840_startup: configuring port %d\n", pnum);
+	mos7840_port = kzalloc(sizeof(struct moschip_port), GFP_KERNEL);
+	if (!mos7840_port)
+		return -ENOMEM;
+
+	/* Initialize all port interrupt end point to port 0 int
+	 * endpoint. Our device has only one interrupt end point
+	 * common to all port */
+
+	mos7840_port->port = port;
+	spin_lock_init(&mos7840_port->pool_lock);
+
+	/* minor is not initialised until later by
+	 * usb-serial.c:get_free_serial() and cannot therefore be used
+	 * to index device instances */
+	mos7840_port->port_num = pnum + 1;
+	dev_dbg(&port->dev, "port->minor = %d\n", port->minor);
+	dev_dbg(&port->dev, "mos7840_port->port_num = %d\n", mos7840_port->port_num);
+
+	if (mos7840_port->port_num == 1) {
+		mos7840_port->SpRegOffset = 0x0;
+		mos7840_port->ControlRegOffset = 0x1;
+		mos7840_port->DcrRegOffset = 0x4;
+	} else {
+		u8 phy_num = mos7840_port->port_num;
+
+		/* Port 2 in the 2-port case uses registers of port 3 */
+		if (serial->num_ports == 2)
+			phy_num = 3;
+
+		mos7840_port->SpRegOffset = 0x8 + 2 * (phy_num - 2);
+		mos7840_port->ControlRegOffset = 0x9 + 2 * (phy_num - 2);
+		mos7840_port->DcrRegOffset = 0x16 + 3 * (phy_num - 2);
+	}
+	mos7840_dump_serial_port(port, mos7840_port);
+	usb_set_serial_port_data(port, mos7840_port);
+
+	/* enable rx_disable bit in control register */
+	status = mos7840_get_reg_sync(port,
+			mos7840_port->ControlRegOffset, &Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "Reading ControlReg failed status-0x%x\n", status);
+		goto error;
+	} else
+		dev_dbg(&port->dev, "ControlReg Reading success val is %x, status%d\n", Data, status);
+	Data |= 0x08;	/* setting driver done bit */
+	Data |= 0x04;	/* sp1_bit to have cts change reflect in
+			   modem status reg */
+
+	/* Data |= 0x20; //rx_disable bit */
+	status = mos7840_set_reg_sync(port,
+			mos7840_port->ControlRegOffset, Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "Writing ControlReg failed(rx_disable) status-0x%x\n", status);
+		goto error;
+	} else
+		dev_dbg(&port->dev, "ControlReg Writing success(rx_disable) status%d\n", status);
+
+	/* Write default values in DCR (i.e 0x01 in DCR0, 0x05 in DCR2
+	   and 0x24 in DCR3 */
+	Data = 0x01;
+	status = mos7840_set_reg_sync(port,
+			(__u16) (mos7840_port->DcrRegOffset + 0), Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "Writing DCR0 failed status-0x%x\n", status);
+		goto error;
+	} else
+		dev_dbg(&port->dev, "DCR0 Writing success status%d\n", status);
+
+	Data = 0x05;
+	status = mos7840_set_reg_sync(port,
+			(__u16) (mos7840_port->DcrRegOffset + 1), Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "Writing DCR1 failed status-0x%x\n", status);
+		goto error;
+	} else
+		dev_dbg(&port->dev, "DCR1 Writing success status%d\n", status);
+
+	Data = 0x24;
+	status = mos7840_set_reg_sync(port,
+			(__u16) (mos7840_port->DcrRegOffset + 2), Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "Writing DCR2 failed status-0x%x\n", status);
+		goto error;
+	} else
+		dev_dbg(&port->dev, "DCR2 Writing success status%d\n", status);
+
+	/* write values in clkstart0x0 and clkmulti 0x20 */
+	Data = 0x0;
+	status = mos7840_set_reg_sync(port, CLK_START_VALUE_REGISTER, Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "Writing CLK_START_VALUE_REGISTER failed status-0x%x\n", status);
+		goto error;
+	} else
+		dev_dbg(&port->dev, "CLK_START_VALUE_REGISTER Writing success status%d\n", status);
+
+	Data = 0x20;
+	status = mos7840_set_reg_sync(port, CLK_MULTI_REGISTER, Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "Writing CLK_MULTI_REGISTER failed status-0x%x\n", status);
+		goto error;
+	} else
+		dev_dbg(&port->dev, "CLK_MULTI_REGISTER Writing success status%d\n", status);
+
+	/* write value 0x0 to scratchpad register */
+	Data = 0x00;
+	status = mos7840_set_uart_reg(port, SCRATCH_PAD_REGISTER, Data);
+	if (status < 0) {
+		dev_dbg(&port->dev, "Writing SCRATCH_PAD_REGISTER failed status-0x%x\n", status);
+		goto error;
+	} else
+		dev_dbg(&port->dev, "SCRATCH_PAD_REGISTER Writing success status%d\n", status);
+
+	/* Zero Length flag register */
+	if ((mos7840_port->port_num != 1) && (serial->num_ports == 2)) {
+		Data = 0xff;
+		status = mos7840_set_reg_sync(port,
+				(__u16) (ZLP_REG1 +
+					((__u16)mos7840_port->port_num)), Data);
+		dev_dbg(&port->dev, "ZLIP offset %x\n",
+				(__u16)(ZLP_REG1 + ((__u16) mos7840_port->port_num)));
+		if (status < 0) {
+			dev_dbg(&port->dev, "Writing ZLP_REG%d failed status-0x%x\n", pnum + 2, status);
+			goto error;
+		} else
+			dev_dbg(&port->dev, "ZLP_REG%d Writing success status%d\n", pnum + 2, status);
+	} else {
+		Data = 0xff;
+		status = mos7840_set_reg_sync(port,
+				(__u16) (ZLP_REG1 +
+					((__u16)mos7840_port->port_num) - 0x1), Data);
+		dev_dbg(&port->dev, "ZLIP offset %x\n",
+				(__u16)(ZLP_REG1 + ((__u16) mos7840_port->port_num) - 0x1));
+		if (status < 0) {
+			dev_dbg(&port->dev, "Writing ZLP_REG%d failed status-0x%x\n", pnum + 1, status);
+			goto error;
+		} else
+			dev_dbg(&port->dev, "ZLP_REG%d Writing success status%d\n", pnum + 1, status);
+
+	}
+
+	mos7840_port->has_led = device_flags & MCS_LED;
+
+	/* Initialize LED timers */
+	if (mos7840_port->has_led) {
+		mos7840_port->led_urb = usb_alloc_urb(0, GFP_KERNEL);
+		mos7840_port->led_dr = kmalloc(sizeof(*mos7840_port->led_dr),
+								GFP_KERNEL);
+		if (!mos7840_port->led_urb || !mos7840_port->led_dr) {
+			status = -ENOMEM;
+			goto error;
+		}
+
+		timer_setup(&mos7840_port->led_timer1, mos7840_led_off, 0);
+		mos7840_port->led_timer1.expires =
+			jiffies + msecs_to_jiffies(LED_ON_MS);
+		timer_setup(&mos7840_port->led_timer2, mos7840_led_flag_off,
+			    0);
+		mos7840_port->led_timer2.expires =
+			jiffies + msecs_to_jiffies(LED_OFF_MS);
+
+		/* Turn off LED */
+		mos7840_set_led_sync(port, MODEM_CONTROL_REGISTER, 0x0300);
+	}
+
+	return 0;
+error:
+	kfree(mos7840_port->led_dr);
+	usb_free_urb(mos7840_port->led_urb);
+	kfree(mos7840_port);
+
+	return status;
+}
+
+static void mos7840_port_remove(struct usb_serial_port *port)
+{
+	struct moschip_port *mos7840_port = usb_get_serial_port_data(port);
+
+	if (mos7840_port->has_led) {
+		/* Turn off LED */
+		mos7840_set_led_sync(port, MODEM_CONTROL_REGISTER, 0x0300);
+
+		del_timer_sync(&mos7840_port->led_timer1);
+		del_timer_sync(&mos7840_port->led_timer2);
+
+		usb_kill_urb(mos7840_port->led_urb);
+		usb_free_urb(mos7840_port->led_urb);
+		kfree(mos7840_port->led_dr);
+	}
+
+	kfree(mos7840_port);
+}
+
+static struct usb_serial_driver moschip7840_4port_device = {
+	.driver = {
+		   .owner = THIS_MODULE,
+		   .name = "mos7840",
+		   },
+	.description = DRIVER_DESC,
+	.id_table = id_table,
+	.num_interrupt_in = 1,
+	.open = mos7840_open,
+	.close = mos7840_close,
+	.write = mos7840_write,
+	.write_room = mos7840_write_room,
+	.chars_in_buffer = mos7840_chars_in_buffer,
+	.throttle = mos7840_throttle,
+	.unthrottle = mos7840_unthrottle,
+	.calc_num_ports = mos7840_calc_num_ports,
+	.probe = mos7840_probe,
+	.attach = mos7840_attach,
+	.ioctl = mos7840_ioctl,
+	.set_termios = mos7840_set_termios,
+	.break_ctl = mos7840_break,
+	.tiocmget = mos7840_tiocmget,
+	.tiocmset = mos7840_tiocmset,
+	.get_icount = usb_serial_generic_get_icount,
+	.port_probe = mos7840_port_probe,
+	.port_remove = mos7840_port_remove,
+	.read_bulk_callback = mos7840_bulk_in_callback,
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+	&moschip7840_4port_device, NULL
+};
+
+module_usb_serial_driver(serial_drivers, id_table);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");