Adding upstream version 6.1.76.upstream/6.1.76upstream

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

1 files changed, 1763 insertions, 0 deletions

diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c
new file mode 100644
index 000000000..1d1f85fab
--- /dev/null
+++ b/drivers/usb/serial/mos7720.c
@@ -0,0 +1,1763 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * mos7720.c
+ *   Controls the Moschip 7720 usb to dual port serial converter
+ *
+ * Copyright 2006 Moschip Semiconductor Tech. Ltd.
+ *
+ * Developed by:
+ * 	Vijaya Kumar <vijaykumar.gn@gmail.com>
+ *	Ajay Kumar <naanuajay@yahoo.com>
+ *	Gurudeva <ngurudeva@yahoo.com>
+ *
+ * Cleaned up from the original by:
+ *	Greg Kroah-Hartman <gregkh@suse.de>
+ *
+ * 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/spinlock.h>
+#include <linux/serial.h>
+#include <linux/serial_reg.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+#include <linux/uaccess.h>
+#include <linux/parport.h>
+
+#define DRIVER_AUTHOR "Aspire Communications pvt Ltd."
+#define DRIVER_DESC "Moschip USB Serial Driver"
+
+/* default urb timeout */
+#define MOS_WDR_TIMEOUT	5000
+
+#define MOS_MAX_PORT	0x02
+#define MOS_WRITE	0x0E
+#define MOS_READ	0x0D
+
+/* Interrupt Routines Defines	*/
+#define SERIAL_IIR_RLS	0x06
+#define SERIAL_IIR_RDA	0x04
+#define SERIAL_IIR_CTI	0x0c
+#define SERIAL_IIR_THR	0x02
+#define SERIAL_IIR_MS	0x00
+
+#define NUM_URBS			16	/* URB Count */
+#define URB_TRANSFER_BUFFER_SIZE	32	/* URB Size */
+
+/* This structure holds all of the local serial port information */
+struct moschip_port {
+	__u8	shadowLCR;		/* last LCR value received */
+	__u8	shadowMCR;		/* last MCR value received */
+	__u8	shadowMSR;		/* last MSR value received */
+	char			open;
+	struct usb_serial_port	*port;	/* loop back to the owner */
+	struct urb		*write_urb_pool[NUM_URBS];
+};
+
+#define USB_VENDOR_ID_MOSCHIP		0x9710
+#define MOSCHIP_DEVICE_ID_7720		0x7720
+#define MOSCHIP_DEVICE_ID_7715		0x7715
+
+static const struct usb_device_id id_table[] = {
+	{ USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7720) },
+	{ USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7715) },
+	{ } /* terminating entry */
+};
+MODULE_DEVICE_TABLE(usb, id_table);
+
+#ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
+
+/* initial values for parport regs */
+#define DCR_INIT_VAL       0x0c	/* SLCTIN, nINIT */
+#define ECR_INIT_VAL       0x00	/* SPP mode */
+
+enum mos7715_pp_modes {
+	SPP = 0<<5,
+	PS2 = 1<<5,      /* moschip calls this 'NIBBLE' mode */
+	PPF = 2<<5,	 /* moschip calls this 'CB-FIFO mode */
+};
+
+struct mos7715_parport {
+	struct parport          *pp;	       /* back to containing struct */
+	struct kref             ref_count;     /* to instance of this struct */
+	bool                    msg_pending;   /* usb sync call pending */
+	struct completion       syncmsg_compl; /* usb sync call completed */
+	struct work_struct      work;          /* restore deferred writes */
+	struct usb_serial       *serial;       /* back to containing struct */
+	__u8	                shadowECR;     /* parallel port regs... */
+	__u8	                shadowDCR;
+	atomic_t                shadowDSR;     /* updated in int-in callback */
+};
+
+/* lock guards against dereferencing NULL ptr in parport ops callbacks */
+static DEFINE_SPINLOCK(release_lock);
+
+#endif	/* CONFIG_USB_SERIAL_MOS7715_PARPORT */
+
+static const unsigned int dummy; /* for clarity in register access fns */
+
+enum mos_regs {
+	MOS7720_THR,		  /* serial port regs */
+	MOS7720_RHR,
+	MOS7720_IER,
+	MOS7720_FCR,
+	MOS7720_ISR,
+	MOS7720_LCR,
+	MOS7720_MCR,
+	MOS7720_LSR,
+	MOS7720_MSR,
+	MOS7720_SPR,
+	MOS7720_DLL,
+	MOS7720_DLM,
+	MOS7720_DPR,		  /* parallel port regs */
+	MOS7720_DSR,
+	MOS7720_DCR,
+	MOS7720_ECR,
+	MOS7720_SP1_REG,	  /* device control regs */
+	MOS7720_SP2_REG,	  /* serial port 2 (7720 only) */
+	MOS7720_PP_REG,
+	MOS7720_SP_CONTROL_REG,
+};
+
+/*
+ * Return the correct value for the Windex field of the setup packet
+ * for a control endpoint message.  See the 7715 datasheet.
+ */
+static inline __u16 get_reg_index(enum mos_regs reg)
+{
+	static const __u16 mos7715_index_lookup_table[] = {
+		0x00,		/* MOS7720_THR */
+		0x00,		/* MOS7720_RHR */
+		0x01,		/* MOS7720_IER */
+		0x02,		/* MOS7720_FCR */
+		0x02,		/* MOS7720_ISR */
+		0x03,		/* MOS7720_LCR */
+		0x04,		/* MOS7720_MCR */
+		0x05,		/* MOS7720_LSR */
+		0x06,		/* MOS7720_MSR */
+		0x07,		/* MOS7720_SPR */
+		0x00,		/* MOS7720_DLL */
+		0x01,		/* MOS7720_DLM */
+		0x00,		/* MOS7720_DPR */
+		0x01,		/* MOS7720_DSR */
+		0x02,		/* MOS7720_DCR */
+		0x0a,		/* MOS7720_ECR */
+		0x01,		/* MOS7720_SP1_REG */
+		0x02,		/* MOS7720_SP2_REG (7720 only) */
+		0x04,		/* MOS7720_PP_REG (7715 only) */
+		0x08,		/* MOS7720_SP_CONTROL_REG */
+	};
+	return mos7715_index_lookup_table[reg];
+}
+
+/*
+ * Return the correct value for the upper byte of the Wvalue field of
+ * the setup packet for a control endpoint message.
+ */
+static inline __u16 get_reg_value(enum mos_regs reg,
+				  unsigned int serial_portnum)
+{
+	if (reg >= MOS7720_SP1_REG)	/* control reg */
+		return 0x0000;
+
+	else if (reg >= MOS7720_DPR)	/* parallel port reg (7715 only) */
+		return 0x0100;
+
+	else			      /* serial port reg */
+		return (serial_portnum + 2) << 8;
+}
+
+/*
+ * Write data byte to the specified device register.  The data is embedded in
+ * the value field of the setup packet. serial_portnum is ignored for registers
+ * not specific to a particular serial port.
+ */
+static int write_mos_reg(struct usb_serial *serial, unsigned int serial_portnum,
+			 enum mos_regs reg, __u8 data)
+{
+	struct usb_device *usbdev = serial->dev;
+	unsigned int pipe = usb_sndctrlpipe(usbdev, 0);
+	__u8 request = (__u8)0x0e;
+	__u8 requesttype = (__u8)0x40;
+	__u16 index = get_reg_index(reg);
+	__u16 value = get_reg_value(reg, serial_portnum) + data;
+	int status = usb_control_msg(usbdev, pipe, request, requesttype, value,
+				     index, NULL, 0, MOS_WDR_TIMEOUT);
+	if (status < 0)
+		dev_err(&usbdev->dev,
+			"mos7720: usb_control_msg() failed: %d\n", status);
+	return status;
+}
+
+/*
+ * Read data byte from the specified device register.  The data returned by the
+ * device is embedded in the value field of the setup packet.  serial_portnum is
+ * ignored for registers that are not specific to a particular serial port.
+ */
+static int read_mos_reg(struct usb_serial *serial, unsigned int serial_portnum,
+			enum mos_regs reg, __u8 *data)
+{
+	struct usb_device *usbdev = serial->dev;
+	unsigned int pipe = usb_rcvctrlpipe(usbdev, 0);
+	__u8 request = (__u8)0x0d;
+	__u8 requesttype = (__u8)0xc0;
+	__u16 index = get_reg_index(reg);
+	__u16 value = get_reg_value(reg, serial_portnum);
+	u8 *buf;
+	int status;
+
+	buf = kmalloc(1, GFP_KERNEL);
+	if (!buf) {
+		*data = 0;
+		return -ENOMEM;
+	}
+
+	status = usb_control_msg(usbdev, pipe, request, requesttype, value,
+				     index, buf, 1, MOS_WDR_TIMEOUT);
+	if (status == 1) {
+		*data = *buf;
+	} else {
+		dev_err(&usbdev->dev,
+			"mos7720: usb_control_msg() failed: %d\n", status);
+		if (status >= 0)
+			status = -EIO;
+		*data = 0;
+	}
+
+	kfree(buf);
+
+	return status;
+}
+
+#ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
+
+static inline int mos7715_change_mode(struct mos7715_parport *mos_parport,
+				      enum mos7715_pp_modes mode)
+{
+	mos_parport->shadowECR = mode;
+	write_mos_reg(mos_parport->serial, dummy, MOS7720_ECR,
+		      mos_parport->shadowECR);
+	return 0;
+}
+
+static void destroy_mos_parport(struct kref *kref)
+{
+	struct mos7715_parport *mos_parport =
+		container_of(kref, struct mos7715_parport, ref_count);
+
+	kfree(mos_parport);
+}
+
+/*
+ * This is the common top part of all parallel port callback operations that
+ * send synchronous messages to the device.  This implements convoluted locking
+ * that avoids two scenarios: (1) a port operation is called after usbserial
+ * has called our release function, at which point struct mos7715_parport has
+ * been destroyed, and (2) the device has been disconnected, but usbserial has
+ * not called the release function yet because someone has a serial port open.
+ * The shared release_lock prevents the first, and the mutex and disconnected
+ * flag maintained by usbserial covers the second.  We also use the msg_pending
+ * flag to ensure that all synchronous usb message calls have completed before
+ * our release function can return.
+ */
+static int parport_prologue(struct parport *pp)
+{
+	struct mos7715_parport *mos_parport;
+
+	spin_lock(&release_lock);
+	mos_parport = pp->private_data;
+	if (unlikely(mos_parport == NULL)) {
+		/* release fn called, port struct destroyed */
+		spin_unlock(&release_lock);
+		return -1;
+	}
+	mos_parport->msg_pending = true;   /* synch usb call pending */
+	reinit_completion(&mos_parport->syncmsg_compl);
+	spin_unlock(&release_lock);
+
+	/* ensure writes from restore are submitted before new requests */
+	if (work_pending(&mos_parport->work))
+		flush_work(&mos_parport->work);
+
+	mutex_lock(&mos_parport->serial->disc_mutex);
+	if (mos_parport->serial->disconnected) {
+		/* device disconnected */
+		mutex_unlock(&mos_parport->serial->disc_mutex);
+		mos_parport->msg_pending = false;
+		complete(&mos_parport->syncmsg_compl);
+		return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * This is the common bottom part of all parallel port functions that send
+ * synchronous messages to the device.
+ */
+static inline void parport_epilogue(struct parport *pp)
+{
+	struct mos7715_parport *mos_parport = pp->private_data;
+	mutex_unlock(&mos_parport->serial->disc_mutex);
+	mos_parport->msg_pending = false;
+	complete(&mos_parport->syncmsg_compl);
+}
+
+static void deferred_restore_writes(struct work_struct *work)
+{
+	struct mos7715_parport *mos_parport;
+
+	mos_parport = container_of(work, struct mos7715_parport, work);
+
+	mutex_lock(&mos_parport->serial->disc_mutex);
+
+	/* if device disconnected, game over */
+	if (mos_parport->serial->disconnected)
+		goto done;
+
+	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
+		      mos_parport->shadowDCR);
+	write_mos_reg(mos_parport->serial, dummy, MOS7720_ECR,
+		      mos_parport->shadowECR);
+done:
+	mutex_unlock(&mos_parport->serial->disc_mutex);
+}
+
+static void parport_mos7715_write_data(struct parport *pp, unsigned char d)
+{
+	struct mos7715_parport *mos_parport = pp->private_data;
+
+	if (parport_prologue(pp) < 0)
+		return;
+	mos7715_change_mode(mos_parport, SPP);
+	write_mos_reg(mos_parport->serial, dummy, MOS7720_DPR, (__u8)d);
+	parport_epilogue(pp);
+}
+
+static unsigned char parport_mos7715_read_data(struct parport *pp)
+{
+	struct mos7715_parport *mos_parport = pp->private_data;
+	unsigned char d;
+
+	if (parport_prologue(pp) < 0)
+		return 0;
+	read_mos_reg(mos_parport->serial, dummy, MOS7720_DPR, &d);
+	parport_epilogue(pp);
+	return d;
+}
+
+static void parport_mos7715_write_control(struct parport *pp, unsigned char d)
+{
+	struct mos7715_parport *mos_parport = pp->private_data;
+	__u8 data;
+
+	if (parport_prologue(pp) < 0)
+		return;
+	data = ((__u8)d & 0x0f) | (mos_parport->shadowDCR & 0xf0);
+	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR, data);
+	mos_parport->shadowDCR = data;
+	parport_epilogue(pp);
+}
+
+static unsigned char parport_mos7715_read_control(struct parport *pp)
+{
+	struct mos7715_parport *mos_parport;
+	__u8 dcr;
+
+	spin_lock(&release_lock);
+	mos_parport = pp->private_data;
+	if (unlikely(mos_parport == NULL)) {
+		spin_unlock(&release_lock);
+		return 0;
+	}
+	dcr = mos_parport->shadowDCR & 0x0f;
+	spin_unlock(&release_lock);
+	return dcr;
+}
+
+static unsigned char parport_mos7715_frob_control(struct parport *pp,
+						  unsigned char mask,
+						  unsigned char val)
+{
+	struct mos7715_parport *mos_parport = pp->private_data;
+	__u8 dcr;
+
+	mask &= 0x0f;
+	val &= 0x0f;
+	if (parport_prologue(pp) < 0)
+		return 0;
+	mos_parport->shadowDCR = (mos_parport->shadowDCR & (~mask)) ^ val;
+	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
+		      mos_parport->shadowDCR);
+	dcr = mos_parport->shadowDCR & 0x0f;
+	parport_epilogue(pp);
+	return dcr;
+}
+
+static unsigned char parport_mos7715_read_status(struct parport *pp)
+{
+	unsigned char status;
+	struct mos7715_parport *mos_parport;
+
+	spin_lock(&release_lock);
+	mos_parport = pp->private_data;
+	if (unlikely(mos_parport == NULL)) {	/* release called */
+		spin_unlock(&release_lock);
+		return 0;
+	}
+	status = atomic_read(&mos_parport->shadowDSR) & 0xf8;
+	spin_unlock(&release_lock);
+	return status;
+}
+
+static void parport_mos7715_enable_irq(struct parport *pp)
+{
+}
+
+static void parport_mos7715_disable_irq(struct parport *pp)
+{
+}
+
+static void parport_mos7715_data_forward(struct parport *pp)
+{
+	struct mos7715_parport *mos_parport = pp->private_data;
+
+	if (parport_prologue(pp) < 0)
+		return;
+	mos7715_change_mode(mos_parport, PS2);
+	mos_parport->shadowDCR &=  ~0x20;
+	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
+		      mos_parport->shadowDCR);
+	parport_epilogue(pp);
+}
+
+static void parport_mos7715_data_reverse(struct parport *pp)
+{
+	struct mos7715_parport *mos_parport = pp->private_data;
+
+	if (parport_prologue(pp) < 0)
+		return;
+	mos7715_change_mode(mos_parport, PS2);
+	mos_parport->shadowDCR |= 0x20;
+	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
+		      mos_parport->shadowDCR);
+	parport_epilogue(pp);
+}
+
+static void parport_mos7715_init_state(struct pardevice *dev,
+				       struct parport_state *s)
+{
+	s->u.pc.ctr = DCR_INIT_VAL;
+	s->u.pc.ecr = ECR_INIT_VAL;
+}
+
+/* N.B. Parport core code requires that this function not block */
+static void parport_mos7715_save_state(struct parport *pp,
+				       struct parport_state *s)
+{
+	struct mos7715_parport *mos_parport;
+
+	spin_lock(&release_lock);
+	mos_parport = pp->private_data;
+	if (unlikely(mos_parport == NULL)) {	/* release called */
+		spin_unlock(&release_lock);
+		return;
+	}
+	s->u.pc.ctr = mos_parport->shadowDCR;
+	s->u.pc.ecr = mos_parport->shadowECR;
+	spin_unlock(&release_lock);
+}
+
+/* N.B. Parport core code requires that this function not block */
+static void parport_mos7715_restore_state(struct parport *pp,
+					  struct parport_state *s)
+{
+	struct mos7715_parport *mos_parport;
+
+	spin_lock(&release_lock);
+	mos_parport = pp->private_data;
+	if (unlikely(mos_parport == NULL)) {	/* release called */
+		spin_unlock(&release_lock);
+		return;
+	}
+	mos_parport->shadowDCR = s->u.pc.ctr;
+	mos_parport->shadowECR = s->u.pc.ecr;
+
+	schedule_work(&mos_parport->work);
+	spin_unlock(&release_lock);
+}
+
+static size_t parport_mos7715_write_compat(struct parport *pp,
+					   const void *buffer,
+					   size_t len, int flags)
+{
+	int retval;
+	struct mos7715_parport *mos_parport = pp->private_data;
+	int actual_len;
+
+	if (parport_prologue(pp) < 0)
+		return 0;
+	mos7715_change_mode(mos_parport, PPF);
+	retval = usb_bulk_msg(mos_parport->serial->dev,
+			      usb_sndbulkpipe(mos_parport->serial->dev, 2),
+			      (void *)buffer, len, &actual_len,
+			      MOS_WDR_TIMEOUT);
+	parport_epilogue(pp);
+	if (retval) {
+		dev_err(&mos_parport->serial->dev->dev,
+			"mos7720: usb_bulk_msg() failed: %d\n", retval);
+		return 0;
+	}
+	return actual_len;
+}
+
+static struct parport_operations parport_mos7715_ops = {
+	.owner =		THIS_MODULE,
+	.write_data =		parport_mos7715_write_data,
+	.read_data =		parport_mos7715_read_data,
+
+	.write_control =	parport_mos7715_write_control,
+	.read_control =		parport_mos7715_read_control,
+	.frob_control =		parport_mos7715_frob_control,
+
+	.read_status =		parport_mos7715_read_status,
+
+	.enable_irq =		parport_mos7715_enable_irq,
+	.disable_irq =		parport_mos7715_disable_irq,
+
+	.data_forward =		parport_mos7715_data_forward,
+	.data_reverse =		parport_mos7715_data_reverse,
+
+	.init_state =		parport_mos7715_init_state,
+	.save_state =		parport_mos7715_save_state,
+	.restore_state =	parport_mos7715_restore_state,
+
+	.compat_write_data =	parport_mos7715_write_compat,
+
+	.nibble_read_data =	parport_ieee1284_read_nibble,
+	.byte_read_data =	parport_ieee1284_read_byte,
+};
+
+/*
+ * Allocate and initialize parallel port control struct, initialize
+ * the parallel port hardware device, and register with the parport subsystem.
+ */
+static int mos7715_parport_init(struct usb_serial *serial)
+{
+	struct mos7715_parport *mos_parport;
+
+	/* allocate and initialize parallel port control struct */
+	mos_parport = kzalloc(sizeof(struct mos7715_parport), GFP_KERNEL);
+	if (!mos_parport)
+		return -ENOMEM;
+
+	mos_parport->msg_pending = false;
+	kref_init(&mos_parport->ref_count);
+	usb_set_serial_data(serial, mos_parport); /* hijack private pointer */
+	mos_parport->serial = serial;
+	INIT_WORK(&mos_parport->work, deferred_restore_writes);
+	init_completion(&mos_parport->syncmsg_compl);
+
+	/* cycle parallel port reset bit */
+	write_mos_reg(mos_parport->serial, dummy, MOS7720_PP_REG, (__u8)0x80);
+	write_mos_reg(mos_parport->serial, dummy, MOS7720_PP_REG, (__u8)0x00);
+
+	/* initialize device registers */
+	mos_parport->shadowDCR = DCR_INIT_VAL;
+	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
+		      mos_parport->shadowDCR);
+	mos_parport->shadowECR = ECR_INIT_VAL;
+	write_mos_reg(mos_parport->serial, dummy, MOS7720_ECR,
+		      mos_parport->shadowECR);
+
+	/* register with parport core */
+	mos_parport->pp = parport_register_port(0, PARPORT_IRQ_NONE,
+						PARPORT_DMA_NONE,
+						&parport_mos7715_ops);
+	if (mos_parport->pp == NULL) {
+		dev_err(&serial->interface->dev,
+			"Could not register parport\n");
+		kref_put(&mos_parport->ref_count, destroy_mos_parport);
+		return -EIO;
+	}
+	mos_parport->pp->private_data = mos_parport;
+	mos_parport->pp->modes = PARPORT_MODE_COMPAT | PARPORT_MODE_PCSPP;
+	mos_parport->pp->dev = &serial->interface->dev;
+	parport_announce_port(mos_parport->pp);
+
+	return 0;
+}
+#endif	/* CONFIG_USB_SERIAL_MOS7715_PARPORT */
+
+/*
+ * mos7720_interrupt_callback
+ *	this is the callback function for when we have received data on the
+ *	interrupt endpoint.
+ */
+static void mos7720_interrupt_callback(struct urb *urb)
+{
+	int result;
+	int length;
+	int status = urb->status;
+	struct device *dev = &urb->dev->dev;
+	__u8 *data;
+	__u8 sp1;
+	__u8 sp2;
+
+	switch (status) {
+	case 0:
+		/* success */
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		/* this urb is terminated, clean up */
+		dev_dbg(dev, "%s - urb shutting down with status: %d\n", __func__, status);
+		return;
+	default:
+		dev_dbg(dev, "%s - nonzero urb status received: %d\n", __func__, status);
+		goto exit;
+	}
+
+	length = urb->actual_length;
+	data = urb->transfer_buffer;
+
+	/* Moschip get 4 bytes
+	 * Byte 1 IIR Port 1 (port.number is 0)
+	 * Byte 2 IIR Port 2 (port.number is 1)
+	 * Byte 3 --------------
+	 * Byte 4 FIFO status for both */
+
+	/* the above description is inverted
+	 * 	oneukum 2007-03-14 */
+
+	if (unlikely(length != 4)) {
+		dev_dbg(dev, "Wrong data !!!\n");
+		return;
+	}
+
+	sp1 = data[3];
+	sp2 = data[2];
+
+	if ((sp1 | sp2) & 0x01) {
+		/* No Interrupt Pending in both the ports */
+		dev_dbg(dev, "No Interrupt !!!\n");
+	} else {
+		switch (sp1 & 0x0f) {
+		case SERIAL_IIR_RLS:
+			dev_dbg(dev, "Serial Port 1: Receiver status error or address bit detected in 9-bit mode\n");
+			break;
+		case SERIAL_IIR_CTI:
+			dev_dbg(dev, "Serial Port 1: Receiver time out\n");
+			break;
+		case SERIAL_IIR_MS:
+			/* dev_dbg(dev, "Serial Port 1: Modem status change\n"); */
+			break;
+		}
+
+		switch (sp2 & 0x0f) {
+		case SERIAL_IIR_RLS:
+			dev_dbg(dev, "Serial Port 2: Receiver status error or address bit detected in 9-bit mode\n");
+			break;
+		case SERIAL_IIR_CTI:
+			dev_dbg(dev, "Serial Port 2: Receiver time out\n");
+			break;
+		case SERIAL_IIR_MS:
+			/* dev_dbg(dev, "Serial Port 2: Modem status change\n"); */
+			break;
+		}
+	}
+
+exit:
+	result = usb_submit_urb(urb, GFP_ATOMIC);
+	if (result)
+		dev_err(dev, "%s - Error %d submitting control urb\n", __func__, result);
+}
+
+/*
+ * mos7715_interrupt_callback
+ *	this is the 7715's callback function for when we have received data on
+ *	the interrupt endpoint.
+ */
+static void mos7715_interrupt_callback(struct urb *urb)
+{
+	int result;
+	int length;
+	int status = urb->status;
+	struct device *dev = &urb->dev->dev;
+	__u8 *data;
+	__u8 iir;
+
+	switch (status) {
+	case 0:
+		/* success */
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+	case -ENODEV:
+		/* this urb is terminated, clean up */
+		dev_dbg(dev, "%s - urb shutting down with status: %d\n", __func__, status);
+		return;
+	default:
+		dev_dbg(dev, "%s - nonzero urb status received: %d\n", __func__, status);
+		goto exit;
+	}
+
+	length = urb->actual_length;
+	data = urb->transfer_buffer;
+
+	/* Structure of data from 7715 device:
+	 * Byte 1: IIR serial Port
+	 * Byte 2: unused
+	 * Byte 2: DSR parallel port
+	 * Byte 4: FIFO status for both */
+
+	if (unlikely(length != 4)) {
+		dev_dbg(dev, "Wrong data !!!\n");
+		return;
+	}
+
+	iir = data[0];
+	if (!(iir & 0x01)) {	/* serial port interrupt pending */
+		switch (iir & 0x0f) {
+		case SERIAL_IIR_RLS:
+			dev_dbg(dev, "Serial Port: Receiver status error or address bit detected in 9-bit mode\n");
+			break;
+		case SERIAL_IIR_CTI:
+			dev_dbg(dev, "Serial Port: Receiver time out\n");
+			break;
+		case SERIAL_IIR_MS:
+			/* dev_dbg(dev, "Serial Port: Modem status change\n"); */
+			break;
+		}
+	}
+
+#ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
+	{       /* update local copy of DSR reg */
+		struct usb_serial_port *port = urb->context;
+		struct mos7715_parport *mos_parport = port->serial->private;
+		if (unlikely(mos_parport == NULL))
+			return;
+		atomic_set(&mos_parport->shadowDSR, data[2]);
+	}
+#endif
+
+exit:
+	result = usb_submit_urb(urb, GFP_ATOMIC);
+	if (result)
+		dev_err(dev, "%s - Error %d submitting control urb\n", __func__, result);
+}
+
+/*
+ * mos7720_bulk_in_callback
+ *	this is the callback function for when we have received data on the
+ *	bulk in endpoint.
+ */
+static void mos7720_bulk_in_callback(struct urb *urb)
+{
+	int retval;
+	unsigned char *data ;
+	struct usb_serial_port *port;
+	int status = urb->status;
+
+	if (status) {
+		dev_dbg(&urb->dev->dev, "nonzero read bulk status received: %d\n", status);
+		return;
+	}
+
+	port = urb->context;
+
+	dev_dbg(&port->dev, "Entering...%s\n", __func__);
+
+	data = urb->transfer_buffer;
+
+	if (urb->actual_length) {
+		tty_insert_flip_string(&port->port, data, urb->actual_length);
+		tty_flip_buffer_push(&port->port);
+	}
+
+	if (port->read_urb->status != -EINPROGRESS) {
+		retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
+		if (retval)
+			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, retval = %d\n", retval);
+	}
+}
+
+/*
+ * mos7720_bulk_out_data_callback
+ *	this is the callback function for when we have finished sending serial
+ *	data on the bulk out endpoint.
+ */
+static void mos7720_bulk_out_data_callback(struct urb *urb)
+{
+	struct moschip_port *mos7720_port;
+	int status = urb->status;
+
+	if (status) {
+		dev_dbg(&urb->dev->dev, "nonzero write bulk status received:%d\n", status);
+		return;
+	}
+
+	mos7720_port = urb->context;
+	if (!mos7720_port) {
+		dev_dbg(&urb->dev->dev, "NULL mos7720_port pointer\n");
+		return ;
+	}
+
+	if (mos7720_port->open)
+		tty_port_tty_wakeup(&mos7720_port->port->port);
+}
+
+static int mos77xx_calc_num_ports(struct usb_serial *serial,
+					struct usb_serial_endpoints *epds)
+{
+	u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
+
+	if (product == MOSCHIP_DEVICE_ID_7715) {
+		/*
+		 * The 7715 uses the first bulk in/out endpoint pair for the
+		 * parallel port, and the second for the serial port. We swap
+		 * the endpoint descriptors here so that the first and
+		 * only registered port structure uses the serial-port
+		 * endpoints.
+		 */
+		swap(epds->bulk_in[0], epds->bulk_in[1]);
+		swap(epds->bulk_out[0], epds->bulk_out[1]);
+
+		return 1;
+	}
+
+	return 2;
+}
+
+static int mos7720_open(struct tty_struct *tty, struct usb_serial_port *port)
+{
+	struct usb_serial *serial;
+	struct urb *urb;
+	struct moschip_port *mos7720_port;
+	int response;
+	int port_number;
+	__u8 data;
+	int allocated_urbs = 0;
+	int j;
+
+	serial = port->serial;
+
+	mos7720_port = usb_get_serial_port_data(port);
+	if (mos7720_port == NULL)
+		return -ENODEV;
+
+	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);
+		mos7720_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(mos7720_port->write_urb_pool[j]);
+			mos7720_port->write_urb_pool[j] = NULL;
+			continue;
+		}
+		allocated_urbs++;
+	}
+
+	if (!allocated_urbs)
+		return -ENOMEM;
+
+	 /* Initialize MCS7720 -- Write Init values to corresponding Registers
+	  *
+	  * Register Index
+	  * 0 : MOS7720_THR/MOS7720_RHR
+	  * 1 : MOS7720_IER
+	  * 2 : MOS7720_FCR
+	  * 3 : MOS7720_LCR
+	  * 4 : MOS7720_MCR
+	  * 5 : MOS7720_LSR
+	  * 6 : MOS7720_MSR
+	  * 7 : MOS7720_SPR
+	  *
+	  * 0x08 : SP1/2 Control Reg
+	  */
+	port_number = port->port_number;
+	read_mos_reg(serial, port_number, MOS7720_LSR, &data);
+
+	dev_dbg(&port->dev, "SS::%p LSR:%x\n", mos7720_port, data);
+
+	write_mos_reg(serial, dummy, MOS7720_SP1_REG, 0x02);
+	write_mos_reg(serial, dummy, MOS7720_SP2_REG, 0x02);
+
+	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
+	write_mos_reg(serial, port_number, MOS7720_FCR, 0x00);
+
+	write_mos_reg(serial, port_number, MOS7720_FCR, 0xcf);
+	mos7720_port->shadowLCR = 0x03;
+	write_mos_reg(serial, port_number, MOS7720_LCR,
+		      mos7720_port->shadowLCR);
+	mos7720_port->shadowMCR = 0x0b;
+	write_mos_reg(serial, port_number, MOS7720_MCR,
+		      mos7720_port->shadowMCR);
+
+	write_mos_reg(serial, port_number, MOS7720_SP_CONTROL_REG, 0x00);
+	read_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, &data);
+	data = data | (port->port_number + 1);
+	write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, data);
+	mos7720_port->shadowLCR = 0x83;
+	write_mos_reg(serial, port_number, MOS7720_LCR,
+		      mos7720_port->shadowLCR);
+	write_mos_reg(serial, port_number, MOS7720_THR, 0x0c);
+	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
+	mos7720_port->shadowLCR = 0x03;
+	write_mos_reg(serial, port_number, MOS7720_LCR,
+		      mos7720_port->shadowLCR);
+	write_mos_reg(serial, port_number, MOS7720_IER, 0x0c);
+
+	response = usb_submit_urb(port->read_urb, GFP_KERNEL);
+	if (response)
+		dev_err(&port->dev, "%s - Error %d submitting read urb\n",
+							__func__, response);
+
+	/* initialize our port settings */
+	mos7720_port->shadowMCR = UART_MCR_OUT2; /* Must set to enable ints! */
+
+	/* send a open port command */
+	mos7720_port->open = 1;
+
+	return 0;
+}
+
+/*
+ * mos7720_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 mos7720_chars_in_buffer(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
+	int i;
+	unsigned int chars = 0;
+
+	for (i = 0; i < NUM_URBS; ++i) {
+		if (mos7720_port->write_urb_pool[i] &&
+		    mos7720_port->write_urb_pool[i]->status == -EINPROGRESS)
+			chars += URB_TRANSFER_BUFFER_SIZE;
+	}
+	dev_dbg(&port->dev, "%s - returns %u\n", __func__, chars);
+	return chars;
+}
+
+static void mos7720_close(struct usb_serial_port *port)
+{
+	struct usb_serial *serial;
+	struct moschip_port *mos7720_port;
+	int j;
+
+	serial = port->serial;
+
+	mos7720_port = usb_get_serial_port_data(port);
+	if (mos7720_port == NULL)
+		return;
+
+	for (j = 0; j < NUM_URBS; ++j)
+		usb_kill_urb(mos7720_port->write_urb_pool[j]);
+
+	/* Freeing Write URBs */
+	for (j = 0; j < NUM_URBS; ++j) {
+		if (mos7720_port->write_urb_pool[j]) {
+			kfree(mos7720_port->write_urb_pool[j]->transfer_buffer);
+			usb_free_urb(mos7720_port->write_urb_pool[j]);
+		}
+	}
+
+	/* While closing port, shutdown all bulk read, write  *
+	 * and interrupt read if they exists, otherwise nop   */
+	usb_kill_urb(port->write_urb);
+	usb_kill_urb(port->read_urb);
+
+	write_mos_reg(serial, port->port_number, MOS7720_MCR, 0x00);
+	write_mos_reg(serial, port->port_number, MOS7720_IER, 0x00);
+
+	mos7720_port->open = 0;
+}
+
+static void mos7720_break(struct tty_struct *tty, int break_state)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	unsigned char data;
+	struct usb_serial *serial;
+	struct moschip_port *mos7720_port;
+
+	serial = port->serial;
+
+	mos7720_port = usb_get_serial_port_data(port);
+	if (mos7720_port == NULL)
+		return;
+
+	if (break_state == -1)
+		data = mos7720_port->shadowLCR | UART_LCR_SBC;
+	else
+		data = mos7720_port->shadowLCR & ~UART_LCR_SBC;
+
+	mos7720_port->shadowLCR  = data;
+	write_mos_reg(serial, port->port_number, MOS7720_LCR,
+		      mos7720_port->shadowLCR);
+}
+
+/*
+ * mos7720_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 mos7720_write_room(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
+	unsigned int room = 0;
+	int i;
+
+	/* FIXME: Locking */
+	for (i = 0; i < NUM_URBS; ++i) {
+		if (mos7720_port->write_urb_pool[i] &&
+		    mos7720_port->write_urb_pool[i]->status != -EINPROGRESS)
+			room += URB_TRANSFER_BUFFER_SIZE;
+	}
+
+	dev_dbg(&port->dev, "%s - returns %u\n", __func__, room);
+	return room;
+}
+
+static int mos7720_write(struct tty_struct *tty, struct usb_serial_port *port,
+				 const unsigned char *data, int count)
+{
+	int status;
+	int i;
+	int bytes_sent = 0;
+	int transfer_size;
+
+	struct moschip_port *mos7720_port;
+	struct usb_serial *serial;
+	struct urb    *urb;
+	const unsigned char *current_position = data;
+
+	serial = port->serial;
+
+	mos7720_port = usb_get_serial_port_data(port);
+	if (mos7720_port == NULL)
+		return -ENODEV;
+
+	/* try to find a free urb in the list */
+	urb = NULL;
+
+	for (i = 0; i < NUM_URBS; ++i) {
+		if (mos7720_port->write_urb_pool[i] &&
+		    mos7720_port->write_urb_pool[i]->status != -EINPROGRESS) {
+			urb = mos7720_port->write_urb_pool[i];
+			dev_dbg(&port->dev, "URB:%d\n", i);
+			break;
+		}
+	}
+
+	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);
+	usb_serial_debug_data(&port->dev, __func__, transfer_size,
+			      urb->transfer_buffer);
+
+	/* fill urb with data and submit  */
+	usb_fill_bulk_urb(urb, serial->dev,
+			  usb_sndbulkpipe(serial->dev,
+					port->bulk_out_endpointAddress),
+			  urb->transfer_buffer, transfer_size,
+			  mos7720_bulk_out_data_callback, mos7720_port);
+
+	/* send it down the pipe */
+	status = usb_submit_urb(urb, GFP_ATOMIC);
+	if (status) {
+		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;
+
+exit:
+	return bytes_sent;
+}
+
+static void mos7720_throttle(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct moschip_port *mos7720_port;
+	int status;
+
+	mos7720_port = usb_get_serial_port_data(port);
+
+	if (mos7720_port == NULL)
+		return;
+
+	if (!mos7720_port->open) {
+		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
+		return;
+	}
+
+	/* if we are implementing XON/XOFF, send the stop character */
+	if (I_IXOFF(tty)) {
+		unsigned char stop_char = STOP_CHAR(tty);
+		status = mos7720_write(tty, port, &stop_char, 1);
+		if (status <= 0)
+			return;
+	}
+
+	/* if we are implementing RTS/CTS, toggle that line */
+	if (C_CRTSCTS(tty)) {
+		mos7720_port->shadowMCR &= ~UART_MCR_RTS;
+		write_mos_reg(port->serial, port->port_number, MOS7720_MCR,
+			      mos7720_port->shadowMCR);
+	}
+}
+
+static void mos7720_unthrottle(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
+	int status;
+
+	if (mos7720_port == NULL)
+		return;
+
+	if (!mos7720_port->open) {
+		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
+		return;
+	}
+
+	/* if we are implementing XON/XOFF, send the start character */
+	if (I_IXOFF(tty)) {
+		unsigned char start_char = START_CHAR(tty);
+		status = mos7720_write(tty, port, &start_char, 1);
+		if (status <= 0)
+			return;
+	}
+
+	/* if we are implementing RTS/CTS, toggle that line */
+	if (C_CRTSCTS(tty)) {
+		mos7720_port->shadowMCR |= UART_MCR_RTS;
+		write_mos_reg(port->serial, port->port_number, MOS7720_MCR,
+			      mos7720_port->shadowMCR);
+	}
+}
+
+/* FIXME: this function does not work */
+static int set_higher_rates(struct moschip_port *mos7720_port,
+			    unsigned int baud)
+{
+	struct usb_serial_port *port;
+	struct usb_serial *serial;
+	int port_number;
+	enum mos_regs sp_reg;
+	if (mos7720_port == NULL)
+		return -EINVAL;
+
+	port = mos7720_port->port;
+	serial = port->serial;
+
+	 /***********************************************
+	 *      Init Sequence for higher rates
+	 ***********************************************/
+	dev_dbg(&port->dev, "Sending Setting Commands ..........\n");
+	port_number = port->port_number;
+
+	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
+	write_mos_reg(serial, port_number, MOS7720_FCR, 0x00);
+	write_mos_reg(serial, port_number, MOS7720_FCR, 0xcf);
+	mos7720_port->shadowMCR = 0x0b;
+	write_mos_reg(serial, port_number, MOS7720_MCR,
+		      mos7720_port->shadowMCR);
+	write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, 0x00);
+
+	/***********************************************
+	 *              Set for higher rates           *
+	 ***********************************************/
+	/* writing baud rate verbatum into uart clock field clearly not right */
+	if (port_number == 0)
+		sp_reg = MOS7720_SP1_REG;
+	else
+		sp_reg = MOS7720_SP2_REG;
+	write_mos_reg(serial, dummy, sp_reg, baud * 0x10);
+	write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, 0x03);
+	mos7720_port->shadowMCR = 0x2b;
+	write_mos_reg(serial, port_number, MOS7720_MCR,
+		      mos7720_port->shadowMCR);
+
+	/***********************************************
+	 *              Set DLL/DLM
+	 ***********************************************/
+	mos7720_port->shadowLCR = mos7720_port->shadowLCR | UART_LCR_DLAB;
+	write_mos_reg(serial, port_number, MOS7720_LCR,
+		      mos7720_port->shadowLCR);
+	write_mos_reg(serial, port_number, MOS7720_DLL, 0x01);
+	write_mos_reg(serial, port_number, MOS7720_DLM, 0x00);
+	mos7720_port->shadowLCR = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
+	write_mos_reg(serial, port_number, MOS7720_LCR,
+		      mos7720_port->shadowLCR);
+
+	return 0;
+}
+
+/* baud rate information */
+struct divisor_table_entry {
+	__u32  baudrate;
+	__u16  divisor;
+};
+
+/* Define table of divisors for moschip 7720 hardware	   *
+ * These assume a 3.6864MHz crystal, the standard /16, and *
+ * MCR.7 = 0.						   */
+static const struct divisor_table_entry divisor_table[] = {
+	{   50,		2304},
+	{   110,	1047},	/* 2094.545455 => 230450   => .0217 % over */
+	{   134,	857},	/* 1713.011152 => 230398.5 => .00065% under */
+	{   150,	768},
+	{   300,	384},
+	{   600,	192},
+	{   1200,	96},
+	{   1800,	64},
+	{   2400,	48},
+	{   4800,	24},
+	{   7200,	16},
+	{   9600,	12},
+	{   19200,	6},
+	{   38400,	3},
+	{   57600,	2},
+	{   115200,	1},
+};
+
+/*****************************************************************************
+ * calc_baud_rate_divisor
+ *	this function calculates the proper baud rate divisor for the specified
+ *	baud rate.
+ *****************************************************************************/
+static int calc_baud_rate_divisor(struct usb_serial_port *port, int baudrate, int *divisor)
+{
+	int i;
+	__u16 custom;
+	__u16 round1;
+	__u16 round;
+
+
+	dev_dbg(&port->dev, "%s - %d\n", __func__, baudrate);
+
+	for (i = 0; i < ARRAY_SIZE(divisor_table); i++) {
+		if (divisor_table[i].baudrate == baudrate) {
+			*divisor = divisor_table[i].divisor;
+			return 0;
+		}
+	}
+
+	/* After trying for all the standard baud rates    *
+	 * Try calculating the divisor for this baud rate  */
+	if (baudrate > 75 &&  baudrate < 230400) {
+		/* get the divisor */
+		custom = (__u16)(230400L  / baudrate);
+
+		/* Check for round off */
+		round1 = (__u16)(2304000L / baudrate);
+		round = (__u16)(round1 - (custom * 10));
+		if (round > 4)
+			custom++;
+		*divisor = custom;
+
+		dev_dbg(&port->dev, "Baud %d = %d\n", baudrate, custom);
+		return 0;
+	}
+
+	dev_dbg(&port->dev, "Baud calculation Failed...\n");
+	return -EINVAL;
+}
+
+/*
+ * send_cmd_write_baud_rate
+ *	this function sends the proper command to change the baud rate of the
+ *	specified port.
+ */
+static int send_cmd_write_baud_rate(struct moschip_port *mos7720_port,
+				    int baudrate)
+{
+	struct usb_serial_port *port;
+	struct usb_serial *serial;
+	int divisor;
+	int status;
+	unsigned char number;
+
+	if (mos7720_port == NULL)
+		return -1;
+
+	port = mos7720_port->port;
+	serial = port->serial;
+
+	number = port->port_number;
+	dev_dbg(&port->dev, "%s - baud = %d\n", __func__, baudrate);
+
+	/* Calculate the Divisor */
+	status = calc_baud_rate_divisor(port, baudrate, &divisor);
+	if (status) {
+		dev_err(&port->dev, "%s - bad baud rate\n", __func__);
+		return status;
+	}
+
+	/* Enable access to divisor latch */
+	mos7720_port->shadowLCR = mos7720_port->shadowLCR | UART_LCR_DLAB;
+	write_mos_reg(serial, number, MOS7720_LCR, mos7720_port->shadowLCR);
+
+	/* Write the divisor */
+	write_mos_reg(serial, number, MOS7720_DLL, (__u8)(divisor & 0xff));
+	write_mos_reg(serial, number, MOS7720_DLM,
+		      (__u8)((divisor & 0xff00) >> 8));
+
+	/* Disable access to divisor latch */
+	mos7720_port->shadowLCR = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
+	write_mos_reg(serial, number, MOS7720_LCR, mos7720_port->shadowLCR);
+
+	return status;
+}
+
+/*
+ * change_port_settings
+ *	This routine is called to set the UART on the device to match
+ *      the specified new settings.
+ */
+static void change_port_settings(struct tty_struct *tty,
+				 struct moschip_port *mos7720_port,
+				 const struct ktermios *old_termios)
+{
+	struct usb_serial_port *port;
+	struct usb_serial *serial;
+	int baud;
+	unsigned cflag;
+	__u8 lData;
+	__u8 lParity;
+	__u8 lStop;
+	int status;
+	int port_number;
+
+	if (mos7720_port == NULL)
+		return ;
+
+	port = mos7720_port->port;
+	serial = port->serial;
+	port_number = port->port_number;
+
+	if (!mos7720_port->open) {
+		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
+		return;
+	}
+
+	lStop = 0x00;	/* 1 stop bit */
+	lParity = 0x00;	/* No parity */
+
+	cflag = tty->termios.c_cflag;
+
+	lData = UART_LCR_WLEN(tty_get_char_size(cflag));
+
+	/* Change the Parity bit */
+	if (cflag & PARENB) {
+		if (cflag & PARODD) {
+			lParity = UART_LCR_PARITY;
+			dev_dbg(&port->dev, "%s - parity = odd\n", __func__);
+		} else {
+			lParity = (UART_LCR_EPAR | UART_LCR_PARITY);
+			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 = UART_LCR_STOP;
+		dev_dbg(&port->dev, "%s - stop bits = 2\n", __func__);
+	} else {
+		lStop = 0x00;
+		dev_dbg(&port->dev, "%s - stop bits = 1\n", __func__);
+	}
+
+#define LCR_BITS_MASK		0x03	/* Mask for bits/char field */
+#define LCR_STOP_MASK		0x04	/* Mask for stop bits field */
+#define LCR_PAR_MASK		0x38	/* Mask for parity field */
+
+	/* Update the LCR with the correct value */
+	mos7720_port->shadowLCR &=
+		~(LCR_BITS_MASK | LCR_STOP_MASK | LCR_PAR_MASK);
+	mos7720_port->shadowLCR |= (lData | lParity | lStop);
+
+
+	/* Disable Interrupts */
+	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
+	write_mos_reg(serial, port_number, MOS7720_FCR, 0x00);
+	write_mos_reg(serial, port_number, MOS7720_FCR, 0xcf);
+
+	/* Send the updated LCR value to the mos7720 */
+	write_mos_reg(serial, port_number, MOS7720_LCR,
+		      mos7720_port->shadowLCR);
+	mos7720_port->shadowMCR = 0x0b;
+	write_mos_reg(serial, port_number, MOS7720_MCR,
+		      mos7720_port->shadowMCR);
+
+	/* set up the MCR register and send it to the mos7720 */
+	mos7720_port->shadowMCR = UART_MCR_OUT2;
+	if (cflag & CBAUD)
+		mos7720_port->shadowMCR |= (UART_MCR_DTR | UART_MCR_RTS);
+
+	if (cflag & CRTSCTS) {
+		mos7720_port->shadowMCR |= (UART_MCR_XONANY);
+		/* To set hardware flow control to the specified *
+		 * serial port, in SP1/2_CONTROL_REG             */
+		if (port_number)
+			write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG,
+				      0x01);
+		else
+			write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG,
+				      0x02);
+
+	} else
+		mos7720_port->shadowMCR &= ~(UART_MCR_XONANY);
+
+	write_mos_reg(serial, port_number, MOS7720_MCR,
+		      mos7720_port->shadowMCR);
+
+	/* Determine divisor based on baud rate */
+	baud = tty_get_baud_rate(tty);
+	if (!baud) {
+		/* pick a default, any default... */
+		dev_dbg(&port->dev, "Picked default baud...\n");
+		baud = 9600;
+	}
+
+	if (baud >= 230400) {
+		set_higher_rates(mos7720_port, baud);
+		/* Enable Interrupts */
+		write_mos_reg(serial, port_number, MOS7720_IER, 0x0c);
+		return;
+	}
+
+	dev_dbg(&port->dev, "%s - baud rate = %d\n", __func__, baud);
+	status = send_cmd_write_baud_rate(mos7720_port, baud);
+	/* FIXME: needs to write actual resulting baud back not just
+	   blindly do so */
+	if (cflag & CBAUD)
+		tty_encode_baud_rate(tty, baud, baud);
+	/* Enable Interrupts */
+	write_mos_reg(serial, port_number, MOS7720_IER, 0x0c);
+
+	if (port->read_urb->status != -EINPROGRESS) {
+		status = usb_submit_urb(port->read_urb, GFP_KERNEL);
+		if (status)
+			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, status = %d\n", status);
+	}
+}
+
+/*
+ * mos7720_set_termios
+ *	this function is called by the tty driver when it wants to change the
+ *	termios structure.
+ */
+static void mos7720_set_termios(struct tty_struct *tty,
+				struct usb_serial_port *port,
+				const struct ktermios *old_termios)
+{
+	int status;
+	struct moschip_port *mos7720_port;
+
+	mos7720_port = usb_get_serial_port_data(port);
+
+	if (mos7720_port == NULL)
+		return;
+
+	if (!mos7720_port->open) {
+		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
+		return;
+	}
+
+	/* change the port settings to the new ones specified */
+	change_port_settings(tty, mos7720_port, old_termios);
+
+	if (port->read_urb->status != -EINPROGRESS) {
+		status = usb_submit_urb(port->read_urb, GFP_KERNEL);
+		if (status)
+			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, status = %d\n", status);
+	}
+}
+
+/*
+ * 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 get_lsr_info(struct tty_struct *tty,
+		struct moschip_port *mos7720_port, unsigned int __user *value)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	unsigned int result = 0;
+	unsigned char data = 0;
+	int port_number = port->port_number;
+	int count;
+
+	count = mos7720_chars_in_buffer(tty);
+	if (count == 0) {
+		read_mos_reg(port->serial, port_number, MOS7720_LSR, &data);
+		if ((data & (UART_LSR_TEMT | UART_LSR_THRE))
+					== (UART_LSR_TEMT | UART_LSR_THRE)) {
+			dev_dbg(&port->dev, "%s -- Empty\n", __func__);
+			result = TIOCSER_TEMT;
+		}
+	}
+	if (copy_to_user(value, &result, sizeof(int)))
+		return -EFAULT;
+	return 0;
+}
+
+static int mos7720_tiocmget(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
+	unsigned int result = 0;
+	unsigned int mcr ;
+	unsigned int msr ;
+
+	mcr = mos7720_port->shadowMCR;
+	msr = mos7720_port->shadowMSR;
+
+	result = ((mcr & UART_MCR_DTR)  ? TIOCM_DTR : 0)   /* 0x002 */
+	  | ((mcr & UART_MCR_RTS)   ? TIOCM_RTS : 0)   /* 0x004 */
+	  | ((msr & UART_MSR_CTS)   ? TIOCM_CTS : 0)   /* 0x020 */
+	  | ((msr & UART_MSR_DCD)   ? TIOCM_CAR : 0)   /* 0x040 */
+	  | ((msr & UART_MSR_RI)    ? TIOCM_RI :  0)   /* 0x080 */
+	  | ((msr & UART_MSR_DSR)   ? TIOCM_DSR : 0);  /* 0x100 */
+
+	return result;
+}
+
+static int mos7720_tiocmset(struct tty_struct *tty,
+			    unsigned int set, unsigned int clear)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
+	unsigned int mcr ;
+
+	mcr = mos7720_port->shadowMCR;
+
+	if (set & TIOCM_RTS)
+		mcr |= UART_MCR_RTS;
+	if (set & TIOCM_DTR)
+		mcr |= UART_MCR_DTR;
+	if (set & TIOCM_LOOP)
+		mcr |= UART_MCR_LOOP;
+
+	if (clear & TIOCM_RTS)
+		mcr &= ~UART_MCR_RTS;
+	if (clear & TIOCM_DTR)
+		mcr &= ~UART_MCR_DTR;
+	if (clear & TIOCM_LOOP)
+		mcr &= ~UART_MCR_LOOP;
+
+	mos7720_port->shadowMCR = mcr;
+	write_mos_reg(port->serial, port->port_number, MOS7720_MCR,
+		      mos7720_port->shadowMCR);
+
+	return 0;
+}
+
+static int mos7720_ioctl(struct tty_struct *tty,
+			 unsigned int cmd, unsigned long arg)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct moschip_port *mos7720_port;
+
+	mos7720_port = usb_get_serial_port_data(port);
+	if (mos7720_port == NULL)
+		return -ENODEV;
+
+	switch (cmd) {
+	case TIOCSERGETLSR:
+		dev_dbg(&port->dev, "%s TIOCSERGETLSR\n", __func__);
+		return get_lsr_info(tty, mos7720_port,
+					(unsigned int __user *)arg);
+	}
+
+	return -ENOIOCTLCMD;
+}
+
+static int mos7720_startup(struct usb_serial *serial)
+{
+	struct usb_device *dev;
+	char data;
+	u16 product;
+	int ret_val;
+
+	product = le16_to_cpu(serial->dev->descriptor.idProduct);
+	dev = serial->dev;
+
+	if (product == MOSCHIP_DEVICE_ID_7715) {
+		struct urb *urb = serial->port[0]->interrupt_in_urb;
+
+		urb->complete = mos7715_interrupt_callback;
+
+#ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
+		ret_val = mos7715_parport_init(serial);
+		if (ret_val < 0)
+			return ret_val;
+#endif
+	}
+	/* start the interrupt urb */
+	ret_val = usb_submit_urb(serial->port[0]->interrupt_in_urb, GFP_KERNEL);
+	if (ret_val) {
+		dev_err(&dev->dev, "failed to submit interrupt urb: %d\n",
+			ret_val);
+	}
+
+	/* LSR For Port 1 */
+	read_mos_reg(serial, 0, MOS7720_LSR, &data);
+	dev_dbg(&dev->dev, "LSR:%x\n", data);
+
+	return 0;
+}
+
+static void mos7720_release(struct usb_serial *serial)
+{
+	usb_kill_urb(serial->port[0]->interrupt_in_urb);
+
+#ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
+	/* close the parallel port */
+
+	if (le16_to_cpu(serial->dev->descriptor.idProduct)
+	    == MOSCHIP_DEVICE_ID_7715) {
+		struct mos7715_parport *mos_parport =
+			usb_get_serial_data(serial);
+
+		/* prevent NULL ptr dereference in port callbacks */
+		spin_lock(&release_lock);
+		mos_parport->pp->private_data = NULL;
+		spin_unlock(&release_lock);
+
+		/* wait for synchronous usb calls to return */
+		if (mos_parport->msg_pending)
+			wait_for_completion_timeout(&mos_parport->syncmsg_compl,
+					    msecs_to_jiffies(MOS_WDR_TIMEOUT));
+		/*
+		 * If delayed work is currently scheduled, wait for it to
+		 * complete. This also implies barriers that ensure the
+		 * below serial clearing is not hoisted above the ->work.
+		 */
+		cancel_work_sync(&mos_parport->work);
+
+		parport_remove_port(mos_parport->pp);
+		usb_set_serial_data(serial, NULL);
+		mos_parport->serial = NULL;
+
+		parport_del_port(mos_parport->pp);
+
+		kref_put(&mos_parport->ref_count, destroy_mos_parport);
+	}
+#endif
+}
+
+static int mos7720_port_probe(struct usb_serial_port *port)
+{
+	struct moschip_port *mos7720_port;
+
+	mos7720_port = kzalloc(sizeof(*mos7720_port), GFP_KERNEL);
+	if (!mos7720_port)
+		return -ENOMEM;
+
+	mos7720_port->port = port;
+
+	usb_set_serial_port_data(port, mos7720_port);
+
+	return 0;
+}
+
+static void mos7720_port_remove(struct usb_serial_port *port)
+{
+	struct moschip_port *mos7720_port;
+
+	mos7720_port = usb_get_serial_port_data(port);
+	kfree(mos7720_port);
+}
+
+static struct usb_serial_driver moschip7720_2port_driver = {
+	.driver = {
+		.owner =	THIS_MODULE,
+		.name =		"moschip7720",
+	},
+	.description		= "Moschip 2 port adapter",
+	.id_table		= id_table,
+	.num_bulk_in		= 2,
+	.num_bulk_out		= 2,
+	.num_interrupt_in	= 1,
+	.calc_num_ports		= mos77xx_calc_num_ports,
+	.open			= mos7720_open,
+	.close			= mos7720_close,
+	.throttle		= mos7720_throttle,
+	.unthrottle		= mos7720_unthrottle,
+	.attach			= mos7720_startup,
+	.release		= mos7720_release,
+	.port_probe		= mos7720_port_probe,
+	.port_remove		= mos7720_port_remove,
+	.ioctl			= mos7720_ioctl,
+	.tiocmget		= mos7720_tiocmget,
+	.tiocmset		= mos7720_tiocmset,
+	.set_termios		= mos7720_set_termios,
+	.write			= mos7720_write,
+	.write_room		= mos7720_write_room,
+	.chars_in_buffer	= mos7720_chars_in_buffer,
+	.break_ctl		= mos7720_break,
+	.read_bulk_callback	= mos7720_bulk_in_callback,
+	.read_int_callback	= mos7720_interrupt_callback,
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+	&moschip7720_2port_driver, NULL
+};
+
+module_usb_serial_driver(serial_drivers, id_table);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL v2");