USB: add usb-serial spcp8x5 driver

Original version of the driver done by Linxb, changes by Harald, and
lots of cleanups by me in order to get it into a mergable state.

Cc: Linxb <xubin.lin@worldplus.com.cn>
Cc: Harald Klein <hari@vt100.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 1075 insertions, 0 deletions

diff --git a/drivers/usb/serial/spcp8x5.c b/drivers/usb/serial/spcp8x5.c
new file mode 100644
index 00000000000..1b46b846f10
--- /dev/null
+++ b/drivers/usb/serial/spcp8x5.c
@@ -0,0 +1,1075 @@
+/*
+ * spcp8x5 USB to serial adaptor driver
+ *
+ * Copyright (C) 2006 Linxb (xubin.lin@worldplus.com.cn)
+ * Copyright (C) 2006 S1 Corp.
+ *
+ * Original driver for 2.6.10 pl2303 driver by
+ *   Greg Kroah-Hartman (greg@kroah.com)
+ * Changes for 2.6.20 by Harald Klein <hari@vt100.at>
+ *
+ *	This program is free software; you can redistribute it and/or modify
+ *	it under the terms of the GNU General Public License as published by
+ *	the Free Software Foundation; either version 2 of the License, or
+ *	(at your option) any later version.
+ *
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.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/usb.h>
+#include <linux/usb/serial.h>
+
+
+/* Version Information */
+#define DRIVER_VERSION 	"v0.04"
+#define DRIVER_DESC 	"SPCP8x5 USB to serial adaptor driver"
+
+static int debug;
+
+#define SPCP8x5_007_VID		0x04FC
+#define SPCP8x5_007_PID		0x0201
+#define SPCP8x5_008_VID		0x04fc
+#define SPCP8x5_008_PID		0x0235
+#define SPCP8x5_PHILIPS_VID	0x0471
+#define SPCP8x5_PHILIPS_PID	0x081e
+#define SPCP8x5_INTERMATIC_VID	0x04FC
+#define SPCP8x5_INTERMATIC_PID	0x0204
+#define SPCP8x5_835_VID		0x04fc
+#define SPCP8x5_835_PID		0x0231
+
+static struct usb_device_id id_table [] = {
+	{ USB_DEVICE(SPCP8x5_PHILIPS_VID , SPCP8x5_PHILIPS_PID)},
+	{ USB_DEVICE(SPCP8x5_INTERMATIC_VID, SPCP8x5_INTERMATIC_PID)},
+	{ USB_DEVICE(SPCP8x5_835_VID, SPCP8x5_835_PID)},
+	{ USB_DEVICE(SPCP8x5_008_VID, SPCP8x5_008_PID)},
+	{ USB_DEVICE(SPCP8x5_007_VID, SPCP8x5_007_PID)},
+	{ }					/* Terminating entry */
+};
+MODULE_DEVICE_TABLE(usb, id_table);
+
+struct spcp8x5_usb_ctrl_arg {
+	u8 	type;
+	u8	cmd;
+	u8	cmd_type;
+	u16	value;
+	u16	index;
+	u16	length;
+};
+
+/* wait 30s before close */
+#define SPCP8x5_CLOSING_WAIT	(30*HZ)
+
+#define SPCP8x5_BUF_SIZE	1024
+
+
+/* spcp8x5 spec register define */
+#define MCR_CONTROL_LINE_RTS		0x02
+#define MCR_CONTROL_LINE_DTR		0x01
+#define MCR_DTR				0x01
+#define MCR_RTS				0x02
+
+#define MSR_STATUS_LINE_DCD		0x80
+#define MSR_STATUS_LINE_RI		0x40
+#define MSR_STATUS_LINE_DSR		0x20
+#define MSR_STATUS_LINE_CTS		0x10
+
+/* verdor command here , we should define myself */
+#define SET_DEFAULT			0x40
+#define SET_DEFAULT_TYPE		0x20
+
+#define SET_UART_FORMAT			0x40
+#define SET_UART_FORMAT_TYPE		0x21
+#define SET_UART_FORMAT_SIZE_5		0x00
+#define SET_UART_FORMAT_SIZE_6		0x01
+#define SET_UART_FORMAT_SIZE_7		0x02
+#define SET_UART_FORMAT_SIZE_8		0x03
+#define SET_UART_FORMAT_STOP_1		0x00
+#define SET_UART_FORMAT_STOP_2		0x04
+#define SET_UART_FORMAT_PAR_NONE	0x00
+#define SET_UART_FORMAT_PAR_ODD		0x10
+#define SET_UART_FORMAT_PAR_EVEN	0x30
+#define SET_UART_FORMAT_PAR_MASK	0xD0
+#define SET_UART_FORMAT_PAR_SPACE	0x90
+
+#define GET_UART_STATUS_TYPE		0xc0
+#define GET_UART_STATUS			0x22
+#define GET_UART_STATUS_MSR		0x06
+
+#define SET_UART_STATUS			0x40
+#define SET_UART_STATUS_TYPE		0x23
+#define SET_UART_STATUS_MCR		0x0004
+#define SET_UART_STATUS_MCR_DTR		0x01
+#define SET_UART_STATUS_MCR_RTS		0x02
+#define SET_UART_STATUS_MCR_LOOP	0x10
+
+#define SET_WORKING_MODE		0x40
+#define SET_WORKING_MODE_TYPE		0x24
+#define SET_WORKING_MODE_U2C		0x00
+#define SET_WORKING_MODE_RS485		0x01
+#define SET_WORKING_MODE_PDMA		0x02
+#define SET_WORKING_MODE_SPP		0x03
+
+#define SET_FLOWCTL_CHAR		0x40
+#define SET_FLOWCTL_CHAR_TYPE		0x25
+
+#define GET_VERSION			0xc0
+#define GET_VERSION_TYPE		0x26
+
+#define SET_REGISTER			0x40
+#define SET_REGISTER_TYPE		0x27
+
+#define	GET_REGISTER			0xc0
+#define GET_REGISTER_TYPE		0x28
+
+#define SET_RAM				0x40
+#define SET_RAM_TYPE			0x31
+
+#define GET_RAM				0xc0
+#define GET_RAM_TYPE			0x32
+
+/* how come ??? */
+#define UART_STATE			0x08
+#define UART_STATE_TRANSIENT_MASK	0x74
+#define UART_DCD			0x01
+#define UART_DSR			0x02
+#define UART_BREAK_ERROR		0x04
+#define UART_RING			0x08
+#define UART_FRAME_ERROR		0x10
+#define UART_PARITY_ERROR		0x20
+#define UART_OVERRUN_ERROR		0x40
+#define UART_CTS			0x80
+
+enum spcp8x5_type {
+	SPCP825_007_TYPE,
+	SPCP825_008_TYPE,
+	SPCP825_PHILIP_TYPE,
+	SPCP825_INTERMATIC_TYPE,
+	SPCP835_TYPE,
+};
+
+/* 1st in 1st out buffer 4 driver */
+struct ringbuf {
+	unsigned int	buf_size;
+	char		*buf_buf;
+	char		*buf_get;
+	char		*buf_put;
+};
+
+/* alloc the ring buf and alloc the buffer itself */
+static inline struct ringbuf *alloc_ringbuf(unsigned int size)
+{
+	struct ringbuf *pb;
+
+	if (size == 0)
+		return NULL;
+
+	pb = kmalloc(sizeof(*pb), GFP_KERNEL);
+	if (pb == NULL)
+		return NULL;
+
+	pb->buf_buf = kmalloc(size, GFP_KERNEL);
+	if (pb->buf_buf == NULL) {
+		kfree(pb);
+		return NULL;
+	}
+
+	pb->buf_size = size;
+	pb->buf_get = pb->buf_put = pb->buf_buf;
+
+	return pb;
+}
+
+/* free the ring buf and the buffer itself */
+static inline void free_ringbuf(struct ringbuf *pb)
+{
+	if (pb != NULL) {
+		kfree(pb->buf_buf);
+		kfree(pb);
+	}
+}
+
+/* clear pipo , juest repoint the pointer here */
+static inline void clear_ringbuf(struct ringbuf *pb)
+{
+	if (pb != NULL)
+		pb->buf_get = pb->buf_put;
+}
+
+/* get the number of data in the pipo */
+static inline unsigned int ringbuf_avail_data(struct ringbuf *pb)
+{
+	if (pb == NULL)
+		return 0;
+	return ((pb->buf_size + pb->buf_put - pb->buf_get) % pb->buf_size);
+}
+
+/* get the number of space in the pipo */
+static inline unsigned int ringbuf_avail_space(struct ringbuf *pb)
+{
+	if (pb == NULL)
+		return 0;
+	return ((pb->buf_size + pb->buf_get - pb->buf_put - 1) % pb->buf_size);
+}
+
+/* put count data into pipo */
+static unsigned int put_ringbuf(struct ringbuf *pb, const char *buf,
+				unsigned int count)
+{
+	unsigned int len;
+
+	if (pb == NULL)
+		return 0;
+
+	len  = ringbuf_avail_space(pb);
+	if (count > len)
+		count = len;
+
+	if (count == 0)
+		return 0;
+
+	len = pb->buf_buf + pb->buf_size - pb->buf_put;
+	if (count > len) {
+		memcpy(pb->buf_put, buf, len);
+		memcpy(pb->buf_buf, buf+len, count - len);
+		pb->buf_put = pb->buf_buf + count - len;
+	} else {
+		memcpy(pb->buf_put, buf, count);
+		if (count < len)
+			pb->buf_put += count;
+		else /* count == len */
+			pb->buf_put = pb->buf_buf;
+	}
+	return count;
+}
+
+/* get count data from pipo */
+static unsigned int get_ringbuf(struct ringbuf *pb, char *buf,
+				unsigned int count)
+{
+	unsigned int len;
+
+	if (pb == NULL || buf == NULL)
+		return 0;
+
+	len = ringbuf_avail_data(pb);
+	if (count > len)
+		count = len;
+
+	if (count == 0)
+		return 0;
+
+	len = pb->buf_buf + pb->buf_size - pb->buf_get;
+	if (count > len) {
+		memcpy(buf, pb->buf_get, len);
+		memcpy(buf+len, pb->buf_buf, count - len);
+		pb->buf_get = pb->buf_buf + count - len;
+	} else {
+		memcpy(buf, pb->buf_get, count);
+		if (count < len)
+			pb->buf_get += count;
+		else /* count == len */
+			pb->buf_get = pb->buf_buf;
+	}
+
+	return count;
+}
+
+static struct usb_driver spcp8x5_driver = {
+	.name =			"spcp8x5",
+	.probe =		usb_serial_probe,
+	.disconnect =		usb_serial_disconnect,
+	.id_table =		id_table,
+	.no_dynamic_id =	1,
+};
+
+
+struct spcp8x5_private {
+	spinlock_t 	lock;
+	struct ringbuf	*buf;
+	int 		write_urb_in_use;
+	enum spcp8x5_type	type;
+	wait_queue_head_t	delta_msr_wait;
+	u8 			line_control;
+	u8 			line_status;
+	u8 			termios_initialized;
+};
+
+/* desc : when device plug in,this function would be called.
+ * thanks to usb_serial subsystem,then do almost every things for us. And what
+ * we should do just alloc the buffer */
+static int spcp8x5_startup(struct usb_serial *serial)
+{
+	struct spcp8x5_private *priv;
+	int i;
+	enum spcp8x5_type type = SPCP825_007_TYPE;
+
+	if (serial->dev->descriptor.idProduct == 0x0201)
+		type = SPCP825_007_TYPE;
+	else if (serial->dev->descriptor.idProduct == 0x0231)
+		type = SPCP835_TYPE;
+	else if (serial->dev->descriptor.idProduct == 0x0235)
+		type = SPCP825_008_TYPE;
+	else if (serial->dev->descriptor.idProduct == 0x0204)
+		type = SPCP825_INTERMATIC_TYPE;
+	else if (serial->dev->descriptor.idProduct == 0x0471 &&
+		 serial->dev->descriptor.idVendor == 0x081e)
+		type = SPCP825_PHILIP_TYPE;
+	dev_dbg(&serial->dev->dev, "device type = %d\n", (int)type);
+
+	for (i = 0; i < serial->num_ports; ++i) {
+		priv = kzalloc(sizeof(struct spcp8x5_private), GFP_KERNEL);
+		if (!priv)
+			goto cleanup;
+
+		spin_lock_init(&priv->lock);
+		priv->buf = alloc_ringbuf(SPCP8x5_BUF_SIZE);
+		if (priv->buf == NULL)
+			goto cleanup2;
+
+		init_waitqueue_head(&priv->delta_msr_wait);
+		priv->type = type;
+		usb_set_serial_port_data(serial->port[i] , priv);
+
+	}
+
+	return 0;
+
+cleanup2:
+	kfree(priv);
+cleanup:
+	for (--i; i >= 0; --i) {
+		priv = usb_get_serial_port_data(serial->port[i]);
+		free_ringbuf(priv->buf);
+		kfree(priv);
+		usb_set_serial_port_data(serial->port[i] , NULL);
+	}
+	return -ENOMEM;
+}
+
+/* call when the device plug out. free all the memory alloced by probe */
+static void spcp8x5_shutdown(struct usb_serial *serial)
+{
+	int i;
+	struct spcp8x5_private *priv;
+
+	for (i = 0; i < serial->num_ports; i++) {
+		priv = usb_get_serial_port_data(serial->port[i]);
+		if (priv) {
+			free_ringbuf(priv->buf);
+			kfree(priv);
+			usb_set_serial_port_data(serial->port[i] , NULL);
+		}
+	}
+}
+
+/* set the modem control line of the device.
+ * NOTE spcp825-007 not supported this */
+static int spcp8x5_set_ctrlLine(struct usb_device *dev, u8 value,
+				enum spcp8x5_type type)
+{
+	int retval;
+	u8 mcr = 0 ;
+
+	if (type == SPCP825_007_TYPE)
+		return -EPERM;
+
+	mcr = (unsigned short)value;
+	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+				 SET_UART_STATUS_TYPE, SET_UART_STATUS,
+				 mcr, 0x04, NULL, 0, 100);
+	if (retval != 0)
+		dev_dbg(&dev->dev, "usb_control_msg return %#x\n", retval);
+	return retval;
+}
+
+/* get the modem status register of the device
+ * NOTE spcp825-007 not supported this */
+static int spcp8x5_get_msr(struct usb_device *dev, u8 *status,
+			   enum spcp8x5_type type)
+{
+	u8 *status_buffer;
+	int ret;
+
+	/* I return Permited not support here but seem inval device
+	 * is more fix */
+	if (type == SPCP825_007_TYPE)
+		return -EPERM;
+	if (status == NULL)
+		return -EINVAL;
+
+	status_buffer = kmalloc(1, GFP_KERNEL);
+	if (!status_buffer)
+		return -ENOMEM;
+	status_buffer[0] = status[0];
+
+	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
+			      GET_UART_STATUS, GET_UART_STATUS_TYPE,
+			      0, GET_UART_STATUS_MSR, status_buffer, 1, 100);
+	if (ret < 0)
+		dev_dbg(&dev->dev, "Get MSR = 0x%p failed (error = %d)",
+			status_buffer, ret);
+
+	dev_dbg(&dev->dev, "0xc0:0x22:0:6  %d - 0x%p ", ret, status_buffer);
+	status[0] = status_buffer[0];
+	kfree(status_buffer);
+
+	return ret;
+}
+
+/* select the work mode.
+ * NOTE this function not supported by spcp825-007 */
+static void spcp8x5_set_workMode(struct usb_device *dev, u16 value,
+				 u16 index, enum spcp8x5_type type)
+{
+	int ret;
+
+	/* I return Permited not support here but seem inval device
+	 * is more fix */
+	if (type == SPCP825_007_TYPE)
+		return;
+
+	ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+			      SET_WORKING_MODE_TYPE, SET_WORKING_MODE,
+			      value, index, NULL, 0, 100);
+	dev_dbg(&dev->dev, "value = %#x , index = %#x\n", value, index);
+	if (ret < 0)
+		dev_dbg(&dev->dev,
+			"RTSCTS usb_control_msg(enable flowctrl) = %d\n", ret);
+}
+
+/* close the serial port. We should wait for data sending to device 1st and
+ * then kill all urb. */
+static void spcp8x5_close(struct usb_serial_port *port, struct file *filp)
+{
+	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	unsigned int c_cflag;
+	int bps;
+	long timeout;
+	wait_queue_t wait;
+	int result;
+
+	dbg("%s - port %d", __func__, port->number);
+
+	/* wait for data to drain from the buffer */
+	spin_lock_irqsave(&priv->lock, flags);
+	timeout = SPCP8x5_CLOSING_WAIT;
+	init_waitqueue_entry(&wait, current);
+	add_wait_queue(&port->tty->write_wait, &wait);
+	for (;;) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (ringbuf_avail_data(priv->buf) == 0 ||
+		    timeout == 0 || signal_pending(current))
+			break;
+		spin_unlock_irqrestore(&priv->lock, flags);
+		timeout = schedule_timeout(timeout);
+		spin_lock_irqsave(&priv->lock, flags);
+	}
+	set_current_state(TASK_RUNNING);
+	remove_wait_queue(&port->tty->write_wait, &wait);
+
+	/* clear out any remaining data in the buffer */
+	clear_ringbuf(priv->buf);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* wait for characters to drain from the device (this is long enough
+	 * for the entire all byte spcp8x5 hardware buffer to drain with no
+	 * flow control for data rates of 1200 bps or more, for lower rates we
+	 * should really know how much data is in the buffer to compute a delay
+	 * that is not unnecessarily long) */
+	bps = tty_get_baud_rate(port->tty);
+	if (bps > 1200)
+		timeout = max((HZ*2560) / bps, HZ/10);
+	else
+		timeout = 2*HZ;
+	set_current_state(TASK_INTERRUPTIBLE);
+	schedule_timeout(timeout);
+
+	/* clear control lines */
+	if (port->tty) {
+		c_cflag = port->tty->termios->c_cflag;
+		if (c_cflag & HUPCL) {
+			spin_lock_irqsave(&priv->lock, flags);
+			priv->line_control = 0;
+			spin_unlock_irqrestore(&priv->lock, flags);
+			spcp8x5_set_ctrlLine(port->serial->dev, 0 , priv->type);
+		}
+	}
+
+	/* kill urb */
+	if (port->write_urb != NULL) {
+		result = usb_unlink_urb(port->write_urb);
+		if (result)
+			dev_dbg(&port->dev,
+				"usb_unlink_urb(write_urb) = %d\n", result);
+	}
+	result = usb_unlink_urb(port->read_urb);
+	if (result)
+		dev_dbg(&port->dev, "usb_unlink_urb(read_urb) = %d\n", result);
+}
+
+/* set the serial param for transfer. we should check if we really need to
+ * transfer. then if be set flow contorl we should do this too. */
+static void spcp8x5_set_termios(struct usb_serial_port *port,
+				struct ktermios *old_termios)
+{
+	struct usb_serial *serial = port->serial;
+	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	unsigned int cflag = port->tty->termios->c_cflag;
+	unsigned int old_cflag = old_termios->c_cflag;
+	unsigned short uartdata;
+	unsigned char buf[2] = {0, 0};
+	int baud;
+	int i;
+	u8 control;
+
+	if ((!port->tty) || (!port->tty->termios))
+		return;
+
+	/* for the 1st time call this function */
+	spin_lock_irqsave(&priv->lock, flags);
+	if (!priv->termios_initialized) {
+		*(port->tty->termios) = tty_std_termios;
+		port->tty->termios->c_cflag = B115200 | CS8 | CREAD |
+					      HUPCL | CLOCAL;
+		priv->termios_initialized = 1;
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* check that they really want us to change something */
+	if (!tty_termios_hw_change(port->tty->termios, old_termios))
+		return;
+
+	/* set DTR/RTS active */
+	spin_lock_irqsave(&priv->lock, flags);
+	control = priv->line_control;
+	if ((old_cflag & CBAUD) == B0) {
+		priv->line_control |= MCR_DTR;
+		if (!(old_cflag & CRTSCTS))
+			priv->line_control |= MCR_RTS;
+	}
+	if (control != priv->line_control) {
+		control = priv->line_control;
+		spin_unlock_irqrestore(&priv->lock, flags);
+		spcp8x5_set_ctrlLine(serial->dev, control , priv->type);
+	} else {
+		spin_unlock_irqrestore(&priv->lock, flags);
+	}
+
+	/* Set Baud Rate */
+	baud = tty_get_baud_rate(port->tty);;
+	switch (baud) {
+	case 300:	buf[0] = 0x00;	break;
+	case 600:	buf[0] = 0x01;	break;
+	case 1200:	buf[0] = 0x02;	break;
+	case 2400:	buf[0] = 0x03;	break;
+	case 4800:	buf[0] = 0x04;	break;
+	case 9600:	buf[0] = 0x05;	break;
+	case 19200:	buf[0] = 0x07;	break;
+	case 38400:	buf[0] = 0x09;	break;
+	case 57600:	buf[0] = 0x0a;	break;
+	case 115200:	buf[0] = 0x0b;	break;
+	case 230400:	buf[0] = 0x0c;	break;
+	case 460800:	buf[0] = 0x0d;	break;
+	case 921600:	buf[0] = 0x0e;	break;
+/*	case 1200000:	buf[0] = 0x0f;	break; */
+/*	case 2400000:	buf[0] = 0x10;	break; */
+	case 3000000:	buf[0] = 0x11;	break;
+/*	case 6000000:	buf[0] = 0x12;	break; */
+	case 0:
+	case 1000000:
+			buf[0] = 0x0b;	break;
+	default:
+		err("spcp825 driver does not support the baudrate "
+		    "requested, using default of 9600.");
+	}
+
+	/* Set Data Length : 00:5bit, 01:6bit, 10:7bit, 11:8bit */
+	if (cflag & CSIZE) {
+		switch (cflag & CSIZE) {
+		case CS5:
+			buf[1] |= SET_UART_FORMAT_SIZE_5;
+			break;
+		case CS6:
+			buf[1] |= SET_UART_FORMAT_SIZE_6;
+			break;
+		case CS7:
+			buf[1] |= SET_UART_FORMAT_SIZE_7;
+			break;
+		default:
+		case CS8:
+			buf[1] |= SET_UART_FORMAT_SIZE_8;
+			break;
+		}
+	}
+
+	/* Set Stop bit2 : 0:1bit 1:2bit */
+	buf[1] |= (cflag & CSTOPB) ? SET_UART_FORMAT_STOP_2 :
+				     SET_UART_FORMAT_STOP_1;
+
+	/* Set Parity bit3-4 01:Odd 11:Even */
+	if (cflag & PARENB) {
+		buf[1] |= (cflag & PARODD) ?
+		SET_UART_FORMAT_PAR_ODD : SET_UART_FORMAT_PAR_EVEN ;
+	} else
+		buf[1] |= SET_UART_FORMAT_PAR_NONE;
+
+	uartdata = buf[0] | buf[1]<<8;
+
+	i = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+			    SET_UART_FORMAT_TYPE, SET_UART_FORMAT,
+			    uartdata, 0, NULL, 0, 100);
+	if (i < 0)
+		err("Set UART format %#x failed (error = %d)", uartdata, i);
+	dbg("0x21:0x40:0:0  %d\n", i);
+
+	if (cflag & CRTSCTS) {
+		/* enable hardware flow control */
+		spcp8x5_set_workMode(serial->dev, 0x000a,
+				     SET_WORKING_MODE_U2C, priv->type);
+	}
+	return;
+}
+
+/* open the serial port. do some usb system call. set termios and get the line
+ * status of the device. then submit the read urb */
+static int spcp8x5_open(struct usb_serial_port *port, struct file *filp)
+{
+	struct ktermios tmp_termios;
+	struct usb_serial *serial = port->serial;
+	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
+	int ret;
+	unsigned long flags;
+	u8 status = 0x30;
+	/* status 0x30 means DSR and CTS = 1 other CDC RI and delta = 0 */
+
+	dbg("%s -  port %d", __func__, port->number);
+
+	usb_clear_halt(serial->dev, port->write_urb->pipe);
+	usb_clear_halt(serial->dev, port->read_urb->pipe);
+
+	ret = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+			      0x09, 0x00,
+			      0x01, 0x00, NULL, 0x00, 100);
+	if (ret)
+		return ret;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (port->tty->termios->c_cflag & CBAUD)
+		priv->line_control = MCR_DTR | MCR_RTS;
+	else
+		priv->line_control = 0;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	spcp8x5_set_ctrlLine(serial->dev, priv->line_control , priv->type);
+
+	/* Setup termios */
+	if (port->tty)
+		spcp8x5_set_termios(port, &tmp_termios);
+
+	spcp8x5_get_msr(serial->dev, &status, priv->type);
+
+	/* may be we should update uart status here but now we did not do */
+	spin_lock_irqsave(&priv->lock, flags);
+	priv->line_status = status & 0xf0 ;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* FIXME: need to assert RTS and DTR if CRTSCTS off */
+
+	dbg("%s - submitting read urb", __func__);
+	port->read_urb->dev = serial->dev;
+	ret = usb_submit_urb(port->read_urb, GFP_KERNEL);
+	if (ret) {
+		spcp8x5_close(port, NULL);
+		return -EPROTO;
+	}
+	return 0;
+}
+
+/* bulk read call back function. check the status of the urb. if transfer
+ * failed return. then update the status and the tty send data to tty subsys.
+ * submit urb again.
+ */
+static void spcp8x5_read_bulk_callback(struct urb *urb)
+{
+	struct usb_serial_port *port = urb->context;
+	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
+	struct tty_struct *tty;
+	unsigned char *data = urb->transfer_buffer;
+	unsigned long flags;
+	int i;
+	int result;
+	u8 status = 0;
+	char tty_flag;
+
+	dev_dbg(&port->dev, "start, urb->status = %d, "
+		"urb->actual_length = %d\n,", urb->status, urb->actual_length);
+
+	/* check the urb status */
+	if (urb->status) {
+		if (!port->open_count)
+			return;
+		if (urb->status == -EPROTO) {
+			/* spcp8x5 mysteriously fails with -EPROTO */
+			/* reschedule the read */
+			urb->status = 0;
+			urb->dev = port->serial->dev;
+			result = usb_submit_urb(urb , GFP_ATOMIC);
+			if (result)
+				dev_dbg(&port->dev,
+					"failed submitting read urb %d\n",
+					result);
+			return;
+		}
+		dev_dbg(&port->dev, "unable to handle the error, exiting.\n");
+		return;
+	}
+
+	/* get tty_flag from status */
+	tty_flag = TTY_NORMAL;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	status = priv->line_status;
+	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
+	spin_unlock_irqrestore(&priv->lock, flags);
+	/* wake up the wait for termios */
+	wake_up_interruptible(&priv->delta_msr_wait);
+
+	/* break takes precedence over parity, which takes precedence over
+	 * framing errors */
+	if (status & UART_BREAK_ERROR)
+		tty_flag = TTY_BREAK;
+	else if (status & UART_PARITY_ERROR)
+		tty_flag = TTY_PARITY;
+	else if (status & UART_FRAME_ERROR)
+		tty_flag = TTY_FRAME;
+	dev_dbg(&port->dev, "tty_flag = %d\n", tty_flag);
+
+	tty = port->tty;
+	if (tty && urb->actual_length) {
+		tty_buffer_request_room(tty, urb->actual_length + 1);
+		/* overrun is special, not associated with a char */
+		if (status & UART_OVERRUN_ERROR)
+			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+		for (i = 0; i < urb->actual_length; ++i)
+			tty_insert_flip_char(tty, data[i], tty_flag);
+		tty_flip_buffer_push(tty);
+	}
+
+	/* Schedule the next read _if_ we are still open */
+	if (port->open_count) {
+		urb->dev = port->serial->dev;
+		result = usb_submit_urb(urb , GFP_ATOMIC);
+		if (result)
+			dev_dbg(&port->dev, "failed submitting read urb %d\n",
+				result);
+	}
+
+	return;
+}
+
+/* get data from ring buffer and then write to usb bus */
+static void spcp8x5_send(struct usb_serial_port *port)
+{
+	int count, result;
+	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	if (priv->write_urb_in_use) {
+		dev_dbg(&port->dev, "write urb still used\n");
+		spin_unlock_irqrestore(&priv->lock, flags);
+		return;
+	}
+
+	/* send the 1st urb for writting */
+	memset(port->write_urb->transfer_buffer , 0x00 , port->bulk_out_size);
+	count = get_ringbuf(priv->buf, port->write_urb->transfer_buffer,
+		port->bulk_out_size);
+
+	if (count == 0) {
+		spin_unlock_irqrestore(&priv->lock, flags);
+		return;
+	}
+
+	/* update the urb status */
+	priv->write_urb_in_use = 1;
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	port->write_urb->transfer_buffer_length = count;
+	port->write_urb->dev = port->serial->dev;
+
+	result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
+	if (result) {
+		dev_dbg(&port->dev, "failed submitting write urb, error %d\n",
+			result);
+		priv->write_urb_in_use = 0;
+		/* TODO: reschedule spcp8x5_send */
+	}
+
+
+	schedule_work(&port->work);
+}
+
+/* this is the call back function for write urb. NOTE we should not sleep in
+ * this routine. check the urb return code and then submit the write urb again
+ * to hold the write loop */
+static void spcp8x5_write_bulk_callback(struct urb *urb)
+{
+	struct usb_serial_port *port = urb->context;
+	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
+	int result;
+
+	switch (urb->status) {
+	case 0:
+		/* success */
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		/* this urb is terminated, clean up */
+		dev_dbg(&port->dev, "urb shutting down with status: %d\n",
+			urb->status);
+		priv->write_urb_in_use = 0;
+		return;
+	default:
+		/* error in the urb, so we have to resubmit it */
+		dbg("%s - Overflow in write", __func__);
+		dbg("%s - nonzero write bulk status received: %d",
+			__func__, urb->status);
+		port->write_urb->transfer_buffer_length = 1;
+		port->write_urb->dev = port->serial->dev;
+		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
+		if (result)
+			dev_dbg(&port->dev,
+				"failed resubmitting write urb %d\n", result);
+		else
+			return;
+	}
+
+	priv->write_urb_in_use = 0;
+
+	/* send any buffered data */
+	spcp8x5_send(port);
+}
+
+/* write data to ring buffer. and then start the write transfer */
+static int spcp8x5_write(struct usb_serial_port *port,
+			 const unsigned char *buf, int count)
+{
+	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+
+	dev_dbg(&port->dev, "%d bytes\n", count);
+
+	if (!count)
+		return count;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	count = put_ringbuf(priv->buf, buf, count);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	spcp8x5_send(port);
+
+	return count;
+}
+
+static int spcp8x5_wait_modem_info(struct usb_serial_port *port,
+				   unsigned int arg)
+{
+	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	unsigned int prevstatus;
+	unsigned int status;
+	unsigned int changed;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	prevstatus = priv->line_status;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	while (1) {
+		/* wake up in bulk read */
+		interruptible_sleep_on(&priv->delta_msr_wait);
+
+		/* see if a signal did it */
+		if (signal_pending(current))
+			return -ERESTARTSYS;
+
+		spin_lock_irqsave(&priv->lock, flags);
+		status = priv->line_status;
+		spin_unlock_irqrestore(&priv->lock, flags);
+
+		changed = prevstatus^status;
+
+		if (((arg & TIOCM_RNG) && (changed & MSR_STATUS_LINE_RI)) ||
+		    ((arg & TIOCM_DSR) && (changed & MSR_STATUS_LINE_DSR)) ||
+		    ((arg & TIOCM_CD)  && (changed & MSR_STATUS_LINE_DCD)) ||
+		    ((arg & TIOCM_CTS) && (changed & MSR_STATUS_LINE_CTS)))
+			return 0;
+
+		prevstatus = status;
+	}
+	/* NOTREACHED */
+	return 0;
+}
+
+static int spcp8x5_ioctl(struct usb_serial_port *port, struct file *file,
+			 unsigned int cmd, unsigned long arg)
+{
+	dbg("%s (%d) cmd = 0x%04x", __func__, port->number, cmd);
+
+	switch (cmd) {
+	case TIOCMIWAIT:
+		dbg("%s (%d) TIOCMIWAIT", __func__,  port->number);
+		return spcp8x5_wait_modem_info(port, arg);
+
+	default:
+		dbg("%s not supported = 0x%04x", __func__, cmd);
+		break;
+	}
+
+	return -ENOIOCTLCMD;
+}
+
+static int spcp8x5_tiocmset(struct usb_serial_port *port, struct file *file,
+			    unsigned int set, unsigned int clear)
+{
+	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	u8 control;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (set & TIOCM_RTS)
+		priv->line_control |= MCR_RTS;
+	if (set & TIOCM_DTR)
+		priv->line_control |= MCR_DTR;
+	if (clear & TIOCM_RTS)
+		priv->line_control &= ~MCR_RTS;
+	if (clear & TIOCM_DTR)
+		priv->line_control &= ~MCR_DTR;
+	control = priv->line_control;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return spcp8x5_set_ctrlLine(port->serial->dev, control , priv->type);
+}
+
+static int spcp8x5_tiocmget(struct usb_serial_port *port, struct file *file)
+{
+	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	unsigned int mcr;
+	unsigned int status;
+	unsigned int result;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	mcr = priv->line_control;
+	status = priv->line_status;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	result = ((mcr & MCR_DTR)			? TIOCM_DTR : 0)
+		  | ((mcr & MCR_RTS)			? TIOCM_RTS : 0)
+		  | ((status & MSR_STATUS_LINE_CTS)	? TIOCM_CTS : 0)
+		  | ((status & MSR_STATUS_LINE_DSR)	? TIOCM_DSR : 0)
+		  | ((status & MSR_STATUS_LINE_RI)	? TIOCM_RI  : 0)
+		  | ((status & MSR_STATUS_LINE_DCD)	? TIOCM_CD  : 0);
+
+	return result;
+}
+
+/* get the avail space room in ring buffer */
+static int spcp8x5_write_room(struct usb_serial_port *port)
+{
+	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
+	int room = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	room = ringbuf_avail_space(priv->buf);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return room;
+}
+
+/* get the number of avail data in write ring buffer */
+static int spcp8x5_chars_in_buffer(struct usb_serial_port *port)
+{
+	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
+	int chars = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	chars = ringbuf_avail_data(priv->buf);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return chars;
+}
+
+/* All of the device info needed for the spcp8x5 SIO serial converter */
+static struct usb_serial_driver spcp8x5_device = {
+	.driver = {
+		.owner =	THIS_MODULE,
+		.name =		"SPCP8x5",
+	},
+	.id_table		= id_table,
+	.num_interrupt_in 	= NUM_DONT_CARE,
+	.num_bulk_in 		= 1,
+	.num_bulk_out		= 1,
+	.num_ports		= 1,
+	.open 			= spcp8x5_open,
+	.close 			= spcp8x5_close,
+	.write 			= spcp8x5_write,
+	.set_termios 		= spcp8x5_set_termios,
+	.ioctl 			= spcp8x5_ioctl,
+	.tiocmget 		= spcp8x5_tiocmget,
+	.tiocmset 		= spcp8x5_tiocmset,
+	.write_room 		= spcp8x5_write_room,
+	.read_bulk_callback 	= spcp8x5_read_bulk_callback,
+	.write_bulk_callback	= spcp8x5_write_bulk_callback,
+	.chars_in_buffer 	= spcp8x5_chars_in_buffer,
+	.attach 		= spcp8x5_startup,
+	.shutdown 		= spcp8x5_shutdown,
+};
+
+static int __init spcp8x5_init(void)
+{
+	int retval;
+	retval = usb_serial_register(&spcp8x5_device);
+	if (retval)
+		goto failed_usb_serial_register;
+	retval = usb_register(&spcp8x5_driver);
+	if (retval)
+		goto failed_usb_register;
+	info(DRIVER_DESC " " DRIVER_VERSION);
+	return 0;
+failed_usb_register:
+	usb_serial_deregister(&spcp8x5_device);
+failed_usb_serial_register:
+	return retval;
+}
+
+static void __exit spcp8x5_exit(void)
+{
+	usb_deregister(&spcp8x5_driver);
+	usb_serial_deregister(&spcp8x5_device);
+}
+
+module_init(spcp8x5_init);
+module_exit(spcp8x5_exit);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL");
+
+module_param(debug, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug enabled or not");