Adding upstream version 6.1.76.upstream/6.1.76upstream

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

1 files changed, 1209 insertions, 0 deletions

diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c
new file mode 100644
index 000000000..1e0c028c5
--- /dev/null
+++ b/drivers/usb/serial/cypress_m8.c
@@ -0,0 +1,1209 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * USB Cypress M8 driver
+ *
+ * 	Copyright (C) 2004
+ * 	    Lonnie Mendez (dignome@gmail.com)
+ *	Copyright (C) 2003,2004
+ *	    Neil Whelchel (koyama@firstlight.net)
+ *
+ * See Documentation/usb/usb-serial.rst for more information on using this
+ * driver
+ *
+ * See http://geocities.com/i0xox0i for information on this driver and the
+ * earthmate usb device.
+ */
+
+/* Thanks to Neil Whelchel for writing the first cypress m8 implementation
+   for linux. */
+/* Thanks to cypress for providing references for the hid reports. */
+/* Thanks to Jiang Zhang for providing links and for general help. */
+/* Code originates and was built up from ftdi_sio, belkin, pl2303 and others.*/
+
+
+#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/moduleparam.h>
+#include <linux/spinlock.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+#include <linux/serial.h>
+#include <linux/kfifo.h>
+#include <linux/delay.h>
+#include <linux/uaccess.h>
+#include <asm/unaligned.h>
+
+#include "cypress_m8.h"
+
+
+static bool stats;
+static int interval;
+static bool unstable_bauds;
+
+#define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
+#define DRIVER_DESC "Cypress USB to Serial Driver"
+
+/* write buffer size defines */
+#define CYPRESS_BUF_SIZE	1024
+
+static const struct usb_device_id id_table_earthmate[] = {
+	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
+	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
+	{ }						/* Terminating entry */
+};
+
+static const struct usb_device_id id_table_cyphidcomrs232[] = {
+	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
+	{ USB_DEVICE(VENDOR_ID_SAI, PRODUCT_ID_CYPHIDCOM) },
+	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
+	{ USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
+	{ }						/* Terminating entry */
+};
+
+static const struct usb_device_id id_table_nokiaca42v2[] = {
+	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
+	{ }						/* Terminating entry */
+};
+
+static const struct usb_device_id id_table_combined[] = {
+	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
+	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
+	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
+	{ USB_DEVICE(VENDOR_ID_SAI, PRODUCT_ID_CYPHIDCOM) },
+	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
+	{ USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
+	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
+	{ }						/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, id_table_combined);
+
+enum packet_format {
+	packet_format_1,  /* b0:status, b1:payload count */
+	packet_format_2   /* b0[7:3]:status, b0[2:0]:payload count */
+};
+
+struct cypress_private {
+	spinlock_t lock;		   /* private lock */
+	int chiptype;			   /* identifier of device, for quirks/etc */
+	int bytes_in;			   /* used for statistics */
+	int bytes_out;			   /* used for statistics */
+	int cmd_count;			   /* used for statistics */
+	int cmd_ctrl;			   /* always set this to 1 before issuing a command */
+	struct kfifo write_fifo;	   /* write fifo */
+	int write_urb_in_use;		   /* write urb in use indicator */
+	int write_urb_interval;            /* interval to use for write urb */
+	int read_urb_interval;             /* interval to use for read urb */
+	int comm_is_ok;                    /* true if communication is (still) ok */
+	__u8 line_control;	   	   /* holds dtr / rts value */
+	__u8 current_status;	   	   /* received from last read - info on dsr,cts,cd,ri,etc */
+	__u8 current_config;	   	   /* stores the current configuration byte */
+	__u8 rx_flags;			   /* throttling - used from whiteheat/ftdi_sio */
+	enum packet_format pkt_fmt;	   /* format to use for packet send / receive */
+	int get_cfg_unsafe;		   /* If true, the CYPRESS_GET_CONFIG is unsafe */
+	int baud_rate;			   /* stores current baud rate in
+					      integer form */
+	char prev_status;		   /* used for TIOCMIWAIT */
+};
+
+/* function prototypes for the Cypress USB to serial device */
+static int  cypress_earthmate_port_probe(struct usb_serial_port *port);
+static int  cypress_hidcom_port_probe(struct usb_serial_port *port);
+static int  cypress_ca42v2_port_probe(struct usb_serial_port *port);
+static void cypress_port_remove(struct usb_serial_port *port);
+static int  cypress_open(struct tty_struct *tty, struct usb_serial_port *port);
+static void cypress_close(struct usb_serial_port *port);
+static void cypress_dtr_rts(struct usb_serial_port *port, int on);
+static int  cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
+			const unsigned char *buf, int count);
+static void cypress_send(struct usb_serial_port *port);
+static unsigned int cypress_write_room(struct tty_struct *tty);
+static void cypress_earthmate_init_termios(struct tty_struct *tty);
+static void cypress_set_termios(struct tty_struct *tty,
+				struct usb_serial_port *port,
+				const struct ktermios *old_termios);
+static int  cypress_tiocmget(struct tty_struct *tty);
+static int  cypress_tiocmset(struct tty_struct *tty,
+			unsigned int set, unsigned int clear);
+static unsigned int cypress_chars_in_buffer(struct tty_struct *tty);
+static void cypress_throttle(struct tty_struct *tty);
+static void cypress_unthrottle(struct tty_struct *tty);
+static void cypress_set_dead(struct usb_serial_port *port);
+static void cypress_read_int_callback(struct urb *urb);
+static void cypress_write_int_callback(struct urb *urb);
+
+static struct usb_serial_driver cypress_earthmate_device = {
+	.driver = {
+		.owner =		THIS_MODULE,
+		.name =			"earthmate",
+	},
+	.description =			"DeLorme Earthmate USB",
+	.id_table =			id_table_earthmate,
+	.num_ports =			1,
+	.port_probe =			cypress_earthmate_port_probe,
+	.port_remove =			cypress_port_remove,
+	.open =				cypress_open,
+	.close =			cypress_close,
+	.dtr_rts =			cypress_dtr_rts,
+	.write =			cypress_write,
+	.write_room =			cypress_write_room,
+	.init_termios =			cypress_earthmate_init_termios,
+	.set_termios =			cypress_set_termios,
+	.tiocmget =			cypress_tiocmget,
+	.tiocmset =			cypress_tiocmset,
+	.tiocmiwait =			usb_serial_generic_tiocmiwait,
+	.chars_in_buffer =		cypress_chars_in_buffer,
+	.throttle =		 	cypress_throttle,
+	.unthrottle =			cypress_unthrottle,
+	.read_int_callback =		cypress_read_int_callback,
+	.write_int_callback =		cypress_write_int_callback,
+};
+
+static struct usb_serial_driver cypress_hidcom_device = {
+	.driver = {
+		.owner =		THIS_MODULE,
+		.name =			"cyphidcom",
+	},
+	.description =			"HID->COM RS232 Adapter",
+	.id_table =			id_table_cyphidcomrs232,
+	.num_ports =			1,
+	.port_probe =			cypress_hidcom_port_probe,
+	.port_remove =			cypress_port_remove,
+	.open =				cypress_open,
+	.close =			cypress_close,
+	.dtr_rts =			cypress_dtr_rts,
+	.write =			cypress_write,
+	.write_room =			cypress_write_room,
+	.set_termios =			cypress_set_termios,
+	.tiocmget =			cypress_tiocmget,
+	.tiocmset =			cypress_tiocmset,
+	.tiocmiwait =			usb_serial_generic_tiocmiwait,
+	.chars_in_buffer =		cypress_chars_in_buffer,
+	.throttle =			cypress_throttle,
+	.unthrottle =			cypress_unthrottle,
+	.read_int_callback =		cypress_read_int_callback,
+	.write_int_callback =		cypress_write_int_callback,
+};
+
+static struct usb_serial_driver cypress_ca42v2_device = {
+	.driver = {
+		.owner =		THIS_MODULE,
+		.name =			"nokiaca42v2",
+	},
+	.description =			"Nokia CA-42 V2 Adapter",
+	.id_table =			id_table_nokiaca42v2,
+	.num_ports =			1,
+	.port_probe =			cypress_ca42v2_port_probe,
+	.port_remove =			cypress_port_remove,
+	.open =				cypress_open,
+	.close =			cypress_close,
+	.dtr_rts =			cypress_dtr_rts,
+	.write =			cypress_write,
+	.write_room =			cypress_write_room,
+	.set_termios =			cypress_set_termios,
+	.tiocmget =			cypress_tiocmget,
+	.tiocmset =			cypress_tiocmset,
+	.tiocmiwait =			usb_serial_generic_tiocmiwait,
+	.chars_in_buffer =		cypress_chars_in_buffer,
+	.throttle =			cypress_throttle,
+	.unthrottle =			cypress_unthrottle,
+	.read_int_callback =		cypress_read_int_callback,
+	.write_int_callback =		cypress_write_int_callback,
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+	&cypress_earthmate_device, &cypress_hidcom_device,
+	&cypress_ca42v2_device, NULL
+};
+
+/*****************************************************************************
+ * Cypress serial helper functions
+ *****************************************************************************/
+
+/* FRWD Dongle hidcom needs to skip reset and speed checks */
+static inline bool is_frwd(struct usb_device *dev)
+{
+	return ((le16_to_cpu(dev->descriptor.idVendor) == VENDOR_ID_FRWD) &&
+		(le16_to_cpu(dev->descriptor.idProduct) == PRODUCT_ID_CYPHIDCOM_FRWD));
+}
+
+static int analyze_baud_rate(struct usb_serial_port *port, speed_t new_rate)
+{
+	struct cypress_private *priv;
+	priv = usb_get_serial_port_data(port);
+
+	if (unstable_bauds)
+		return new_rate;
+
+	/* FRWD Dongle uses 115200 bps */
+	if (is_frwd(port->serial->dev))
+		return new_rate;
+
+	/*
+	 * The general purpose firmware for the Cypress M8 allows for
+	 * a maximum speed of 57600bps (I have no idea whether DeLorme
+	 * chose to use the general purpose firmware or not), if you
+	 * need to modify this speed setting for your own project
+	 * please add your own chiptype and modify the code likewise.
+	 * The Cypress HID->COM device will work successfully up to
+	 * 115200bps (but the actual throughput is around 3kBps).
+	 */
+	if (port->serial->dev->speed == USB_SPEED_LOW) {
+		/*
+		 * Mike Isely <isely@pobox.com> 2-Feb-2008: The
+		 * Cypress app note that describes this mechanism
+		 * states that the low-speed part can't handle more
+		 * than 800 bytes/sec, in which case 4800 baud is the
+		 * safest speed for a part like that.
+		 */
+		if (new_rate > 4800) {
+			dev_dbg(&port->dev,
+				"%s - failed setting baud rate, device incapable speed %d\n",
+				__func__, new_rate);
+			return -1;
+		}
+	}
+	switch (priv->chiptype) {
+	case CT_EARTHMATE:
+		if (new_rate <= 600) {
+			/* 300 and 600 baud rates are supported under
+			 * the generic firmware, but are not used with
+			 * NMEA and SiRF protocols */
+			dev_dbg(&port->dev,
+				"%s - failed setting baud rate, unsupported speed of %d on Earthmate GPS\n",
+				__func__, new_rate);
+			return -1;
+		}
+		break;
+	default:
+		break;
+	}
+	return new_rate;
+}
+
+
+/* This function can either set or retrieve the current serial line settings */
+static int cypress_serial_control(struct tty_struct *tty,
+	struct usb_serial_port *port, speed_t baud_rate, int data_bits,
+	int stop_bits, int parity_enable, int parity_type, int reset,
+	int cypress_request_type)
+{
+	int new_baudrate = 0, retval = 0, tries = 0;
+	struct cypress_private *priv;
+	struct device *dev = &port->dev;
+	u8 *feature_buffer;
+	const unsigned int feature_len = 5;
+	unsigned long flags;
+
+	priv = usb_get_serial_port_data(port);
+
+	if (!priv->comm_is_ok)
+		return -ENODEV;
+
+	feature_buffer = kcalloc(feature_len, sizeof(u8), GFP_KERNEL);
+	if (!feature_buffer)
+		return -ENOMEM;
+
+	switch (cypress_request_type) {
+	case CYPRESS_SET_CONFIG:
+		/* 0 means 'Hang up' so doesn't change the true bit rate */
+		new_baudrate = priv->baud_rate;
+		if (baud_rate && baud_rate != priv->baud_rate) {
+			dev_dbg(dev, "%s - baud rate is changing\n", __func__);
+			retval = analyze_baud_rate(port, baud_rate);
+			if (retval >= 0) {
+				new_baudrate = retval;
+				dev_dbg(dev, "%s - New baud rate set to %d\n",
+					__func__, new_baudrate);
+			}
+		}
+		dev_dbg(dev, "%s - baud rate is being sent as %d\n", __func__,
+			new_baudrate);
+
+		/* fill the feature_buffer with new configuration */
+		put_unaligned_le32(new_baudrate, feature_buffer);
+		feature_buffer[4] |= data_bits - 5;   /* assign data bits in 2 bit space ( max 3 ) */
+		/* 1 bit gap */
+		feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
+		feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
+		feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
+		/* 1 bit gap */
+		feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
+
+		dev_dbg(dev, "%s - device is being sent this feature report:\n", __func__);
+		dev_dbg(dev, "%s - %02X - %02X - %02X - %02X - %02X\n", __func__,
+			feature_buffer[0], feature_buffer[1],
+			feature_buffer[2], feature_buffer[3],
+			feature_buffer[4]);
+
+		do {
+			retval = usb_control_msg(port->serial->dev,
+					usb_sndctrlpipe(port->serial->dev, 0),
+					HID_REQ_SET_REPORT,
+					USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
+					0x0300, 0, feature_buffer,
+					feature_len, 500);
+
+			if (tries++ >= 3)
+				break;
+
+		} while (retval != feature_len &&
+			 retval != -ENODEV);
+
+		if (retval != feature_len) {
+			dev_err(dev, "%s - failed sending serial line settings - %d\n",
+				__func__, retval);
+			cypress_set_dead(port);
+		} else {
+			spin_lock_irqsave(&priv->lock, flags);
+			priv->baud_rate = new_baudrate;
+			priv->current_config = feature_buffer[4];
+			spin_unlock_irqrestore(&priv->lock, flags);
+			/* If we asked for a speed change encode it */
+			if (baud_rate)
+				tty_encode_baud_rate(tty,
+					new_baudrate, new_baudrate);
+		}
+	break;
+	case CYPRESS_GET_CONFIG:
+		if (priv->get_cfg_unsafe) {
+			/* Not implemented for this device,
+			   and if we try to do it we're likely
+			   to crash the hardware. */
+			retval = -ENOTTY;
+			goto out;
+		}
+		dev_dbg(dev, "%s - retrieving serial line settings\n", __func__);
+		do {
+			retval = usb_control_msg(port->serial->dev,
+					usb_rcvctrlpipe(port->serial->dev, 0),
+					HID_REQ_GET_REPORT,
+					USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
+					0x0300, 0, feature_buffer,
+					feature_len, 500);
+
+			if (tries++ >= 3)
+				break;
+		} while (retval != feature_len
+						&& retval != -ENODEV);
+
+		if (retval != feature_len) {
+			dev_err(dev, "%s - failed to retrieve serial line settings - %d\n",
+				__func__, retval);
+			cypress_set_dead(port);
+			goto out;
+		} else {
+			spin_lock_irqsave(&priv->lock, flags);
+			/* store the config in one byte, and later
+			   use bit masks to check values */
+			priv->current_config = feature_buffer[4];
+			priv->baud_rate = get_unaligned_le32(feature_buffer);
+			spin_unlock_irqrestore(&priv->lock, flags);
+		}
+	}
+	spin_lock_irqsave(&priv->lock, flags);
+	++priv->cmd_count;
+	spin_unlock_irqrestore(&priv->lock, flags);
+out:
+	kfree(feature_buffer);
+	return retval;
+} /* cypress_serial_control */
+
+
+static void cypress_set_dead(struct usb_serial_port *port)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (!priv->comm_is_ok) {
+		spin_unlock_irqrestore(&priv->lock, flags);
+		return;
+	}
+	priv->comm_is_ok = 0;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	dev_err(&port->dev, "cypress_m8 suspending failing port %d - "
+		"interval might be too short\n", port->port_number);
+}
+
+
+/*****************************************************************************
+ * Cypress serial driver functions
+ *****************************************************************************/
+
+
+static int cypress_generic_port_probe(struct usb_serial_port *port)
+{
+	struct usb_serial *serial = port->serial;
+	struct cypress_private *priv;
+
+	if (!port->interrupt_out_urb || !port->interrupt_in_urb) {
+		dev_err(&port->dev, "required endpoint is missing\n");
+		return -ENODEV;
+	}
+
+	priv = kzalloc(sizeof(struct cypress_private), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->comm_is_ok = !0;
+	spin_lock_init(&priv->lock);
+	if (kfifo_alloc(&priv->write_fifo, CYPRESS_BUF_SIZE, GFP_KERNEL)) {
+		kfree(priv);
+		return -ENOMEM;
+	}
+
+	/* Skip reset for FRWD device. It is a workaound:
+	   device hangs if it receives SET_CONFIGURE in Configured
+	   state. */
+	if (!is_frwd(serial->dev))
+		usb_reset_configuration(serial->dev);
+
+	priv->cmd_ctrl = 0;
+	priv->line_control = 0;
+	priv->rx_flags = 0;
+	/* Default packet format setting is determined by packet size.
+	   Anything with a size larger then 9 must have a separate
+	   count field since the 3 bit count field is otherwise too
+	   small.  Otherwise we can use the slightly more compact
+	   format.  This is in accordance with the cypress_m8 serial
+	   converter app note. */
+	if (port->interrupt_out_size > 9)
+		priv->pkt_fmt = packet_format_1;
+	else
+		priv->pkt_fmt = packet_format_2;
+
+	if (interval > 0) {
+		priv->write_urb_interval = interval;
+		priv->read_urb_interval = interval;
+		dev_dbg(&port->dev, "%s - read & write intervals forced to %d\n",
+			__func__, interval);
+	} else {
+		priv->write_urb_interval = port->interrupt_out_urb->interval;
+		priv->read_urb_interval = port->interrupt_in_urb->interval;
+		dev_dbg(&port->dev, "%s - intervals: read=%d write=%d\n",
+			__func__, priv->read_urb_interval,
+			priv->write_urb_interval);
+	}
+	usb_set_serial_port_data(port, priv);
+
+	port->port.drain_delay = 256;
+
+	return 0;
+}
+
+
+static int cypress_earthmate_port_probe(struct usb_serial_port *port)
+{
+	struct usb_serial *serial = port->serial;
+	struct cypress_private *priv;
+	int ret;
+
+	ret = cypress_generic_port_probe(port);
+	if (ret) {
+		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
+		return ret;
+	}
+
+	priv = usb_get_serial_port_data(port);
+	priv->chiptype = CT_EARTHMATE;
+	/* All Earthmate devices use the separated-count packet
+	   format!  Idiotic. */
+	priv->pkt_fmt = packet_format_1;
+	if (serial->dev->descriptor.idProduct !=
+				cpu_to_le16(PRODUCT_ID_EARTHMATEUSB)) {
+		/* The old original USB Earthmate seemed able to
+		   handle GET_CONFIG requests; everything they've
+		   produced since that time crashes if this command is
+		   attempted :-( */
+		dev_dbg(&port->dev,
+			"%s - Marking this device as unsafe for GET_CONFIG commands\n",
+			__func__);
+		priv->get_cfg_unsafe = !0;
+	}
+
+	return 0;
+}
+
+static int cypress_hidcom_port_probe(struct usb_serial_port *port)
+{
+	struct cypress_private *priv;
+	int ret;
+
+	ret = cypress_generic_port_probe(port);
+	if (ret) {
+		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
+		return ret;
+	}
+
+	priv = usb_get_serial_port_data(port);
+	priv->chiptype = CT_CYPHIDCOM;
+
+	return 0;
+}
+
+static int cypress_ca42v2_port_probe(struct usb_serial_port *port)
+{
+	struct cypress_private *priv;
+	int ret;
+
+	ret = cypress_generic_port_probe(port);
+	if (ret) {
+		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
+		return ret;
+	}
+
+	priv = usb_get_serial_port_data(port);
+	priv->chiptype = CT_CA42V2;
+
+	return 0;
+}
+
+static void cypress_port_remove(struct usb_serial_port *port)
+{
+	struct cypress_private *priv;
+
+	priv = usb_get_serial_port_data(port);
+
+	kfifo_free(&priv->write_fifo);
+	kfree(priv);
+}
+
+static int cypress_open(struct tty_struct *tty, struct usb_serial_port *port)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	struct usb_serial *serial = port->serial;
+	unsigned long flags;
+	int result = 0;
+
+	if (!priv->comm_is_ok)
+		return -EIO;
+
+	/* clear halts before open */
+	usb_clear_halt(serial->dev, 0x81);
+	usb_clear_halt(serial->dev, 0x02);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	/* reset read/write statistics */
+	priv->bytes_in = 0;
+	priv->bytes_out = 0;
+	priv->cmd_count = 0;
+	priv->rx_flags = 0;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* Set termios */
+	cypress_send(port);
+
+	if (tty)
+		cypress_set_termios(tty, port, NULL);
+
+	/* setup the port and start reading from the device */
+	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
+		usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
+		port->interrupt_in_urb->transfer_buffer,
+		port->interrupt_in_urb->transfer_buffer_length,
+		cypress_read_int_callback, port, priv->read_urb_interval);
+	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
+
+	if (result) {
+		dev_err(&port->dev,
+			"%s - failed submitting read urb, error %d\n",
+							__func__, result);
+		cypress_set_dead(port);
+	}
+
+	return result;
+} /* cypress_open */
+
+static void cypress_dtr_rts(struct usb_serial_port *port, int on)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	/* drop dtr and rts */
+	spin_lock_irq(&priv->lock);
+	if (on == 0)
+		priv->line_control = 0;
+	else 
+		priv->line_control = CONTROL_DTR | CONTROL_RTS;
+	priv->cmd_ctrl = 1;
+	spin_unlock_irq(&priv->lock);
+	cypress_write(NULL, port, NULL, 0);
+}
+
+static void cypress_close(struct usb_serial_port *port)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	kfifo_reset_out(&priv->write_fifo);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	dev_dbg(&port->dev, "%s - stopping urbs\n", __func__);
+	usb_kill_urb(port->interrupt_in_urb);
+	usb_kill_urb(port->interrupt_out_urb);
+
+	if (stats)
+		dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
+			priv->bytes_in, priv->bytes_out, priv->cmd_count);
+} /* cypress_close */
+
+
+static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
+					const unsigned char *buf, int count)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+
+	dev_dbg(&port->dev, "%s - %d bytes\n", __func__, count);
+
+	/* line control commands, which need to be executed immediately,
+	   are not put into the buffer for obvious reasons.
+	 */
+	if (priv->cmd_ctrl) {
+		count = 0;
+		goto finish;
+	}
+
+	if (!count)
+		return count;
+
+	count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock);
+
+finish:
+	cypress_send(port);
+
+	return count;
+} /* cypress_write */
+
+
+static void cypress_send(struct usb_serial_port *port)
+{
+	int count = 0, result, offset, actual_size;
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	struct device *dev = &port->dev;
+	unsigned long flags;
+
+	if (!priv->comm_is_ok)
+		return;
+
+	dev_dbg(dev, "%s - interrupt out size is %d\n", __func__,
+		port->interrupt_out_size);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (priv->write_urb_in_use) {
+		dev_dbg(dev, "%s - can't write, urb in use\n", __func__);
+		spin_unlock_irqrestore(&priv->lock, flags);
+		return;
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* clear buffer */
+	memset(port->interrupt_out_urb->transfer_buffer, 0,
+						port->interrupt_out_size);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	switch (priv->pkt_fmt) {
+	default:
+	case packet_format_1:
+		/* this is for the CY7C64013... */
+		offset = 2;
+		port->interrupt_out_buffer[0] = priv->line_control;
+		break;
+	case packet_format_2:
+		/* this is for the CY7C63743... */
+		offset = 1;
+		port->interrupt_out_buffer[0] = priv->line_control;
+		break;
+	}
+
+	if (priv->line_control & CONTROL_RESET)
+		priv->line_control &= ~CONTROL_RESET;
+
+	if (priv->cmd_ctrl) {
+		priv->cmd_count++;
+		dev_dbg(dev, "%s - line control command being issued\n", __func__);
+		spin_unlock_irqrestore(&priv->lock, flags);
+		goto send;
+	} else
+		spin_unlock_irqrestore(&priv->lock, flags);
+
+	count = kfifo_out_locked(&priv->write_fifo,
+					&port->interrupt_out_buffer[offset],
+					port->interrupt_out_size - offset,
+					&priv->lock);
+	if (count == 0)
+		return;
+
+	switch (priv->pkt_fmt) {
+	default:
+	case packet_format_1:
+		port->interrupt_out_buffer[1] = count;
+		break;
+	case packet_format_2:
+		port->interrupt_out_buffer[0] |= count;
+	}
+
+	dev_dbg(dev, "%s - count is %d\n", __func__, count);
+
+send:
+	spin_lock_irqsave(&priv->lock, flags);
+	priv->write_urb_in_use = 1;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	if (priv->cmd_ctrl)
+		actual_size = 1;
+	else
+		actual_size = count +
+			      (priv->pkt_fmt == packet_format_1 ? 2 : 1);
+
+	usb_serial_debug_data(dev, __func__, port->interrupt_out_size,
+			      port->interrupt_out_urb->transfer_buffer);
+
+	usb_fill_int_urb(port->interrupt_out_urb, port->serial->dev,
+		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
+		port->interrupt_out_buffer, actual_size,
+		cypress_write_int_callback, port, priv->write_urb_interval);
+	result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
+	if (result) {
+		dev_err_console(port,
+				"%s - failed submitting write urb, error %d\n",
+							__func__, result);
+		priv->write_urb_in_use = 0;
+		cypress_set_dead(port);
+	}
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (priv->cmd_ctrl)
+		priv->cmd_ctrl = 0;
+
+	/* do not count the line control and size bytes */
+	priv->bytes_out += count;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	usb_serial_port_softint(port);
+} /* cypress_send */
+
+
+/* returns how much space is available in the soft buffer */
+static unsigned int cypress_write_room(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	unsigned int room;
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	room = kfifo_avail(&priv->write_fifo);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	dev_dbg(&port->dev, "%s - returns %u\n", __func__, room);
+	return room;
+}
+
+
+static int cypress_tiocmget(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	__u8 status, control;
+	unsigned int result = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	control = priv->line_control;
+	status = priv->current_status;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
+		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
+		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
+		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
+		| ((status & UART_RI)         ? TIOCM_RI  : 0)
+		| ((status & UART_CD)         ? TIOCM_CD  : 0);
+
+	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
+
+	return result;
+}
+
+
+static int cypress_tiocmset(struct tty_struct *tty,
+			       unsigned int set, unsigned int clear)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (set & TIOCM_RTS)
+		priv->line_control |= CONTROL_RTS;
+	if (set & TIOCM_DTR)
+		priv->line_control |= CONTROL_DTR;
+	if (clear & TIOCM_RTS)
+		priv->line_control &= ~CONTROL_RTS;
+	if (clear & TIOCM_DTR)
+		priv->line_control &= ~CONTROL_DTR;
+	priv->cmd_ctrl = 1;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return cypress_write(tty, port, NULL, 0);
+}
+
+static void cypress_earthmate_init_termios(struct tty_struct *tty)
+{
+	tty_encode_baud_rate(tty, 4800, 4800);
+}
+
+static void cypress_set_termios(struct tty_struct *tty,
+				struct usb_serial_port *port,
+				const struct ktermios *old_termios)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	struct device *dev = &port->dev;
+	int data_bits, stop_bits, parity_type, parity_enable;
+	unsigned int cflag;
+	unsigned long flags;
+	__u8 oldlines;
+	int linechange = 0;
+
+	/* Unsupported features need clearing */
+	tty->termios.c_cflag &= ~(CMSPAR|CRTSCTS);
+
+	cflag = tty->termios.c_cflag;
+
+	/* set number of data bits, parity, stop bits */
+	/* when parity is disabled the parity type bit is ignored */
+
+	/* 1 means 2 stop bits, 0 means 1 stop bit */
+	stop_bits = cflag & CSTOPB ? 1 : 0;
+
+	if (cflag & PARENB) {
+		parity_enable = 1;
+		/* 1 means odd parity, 0 means even parity */
+		parity_type = cflag & PARODD ? 1 : 0;
+	} else
+		parity_enable = parity_type = 0;
+
+	data_bits = tty_get_char_size(cflag);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	oldlines = priv->line_control;
+	if ((cflag & CBAUD) == B0) {
+		/* drop dtr and rts */
+		dev_dbg(dev, "%s - dropping the lines, baud rate 0bps\n", __func__);
+		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
+	} else
+		priv->line_control = (CONTROL_DTR | CONTROL_RTS);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	dev_dbg(dev, "%s - sending %d stop_bits, %d parity_enable, %d parity_type, %d data_bits (+5)\n",
+		__func__, stop_bits, parity_enable, parity_type, data_bits);
+
+	cypress_serial_control(tty, port, tty_get_baud_rate(tty),
+			data_bits, stop_bits,
+			parity_enable, parity_type,
+			0, CYPRESS_SET_CONFIG);
+
+	/* we perform a CYPRESS_GET_CONFIG so that the current settings are
+	 * filled into the private structure this should confirm that all is
+	 * working if it returns what we just set */
+	cypress_serial_control(tty, port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
+
+	/* Here we can define custom tty settings for devices; the main tty
+	 * termios flag base comes from empeg.c */
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (priv->chiptype == CT_EARTHMATE && priv->baud_rate == 4800) {
+		dev_dbg(dev, "Using custom termios settings for a baud rate of 4800bps.\n");
+		/* define custom termios settings for NMEA protocol */
+
+		tty->termios.c_iflag /* input modes - */
+			&= ~(IGNBRK  /* disable ignore break */
+			| BRKINT     /* disable break causes interrupt */
+			| PARMRK     /* disable mark parity errors */
+			| ISTRIP     /* disable clear high bit of input char */
+			| INLCR      /* disable translate NL to CR */
+			| IGNCR      /* disable ignore CR */
+			| ICRNL      /* disable translate CR to NL */
+			| IXON);     /* disable enable XON/XOFF flow control */
+
+		tty->termios.c_oflag /* output modes */
+			&= ~OPOST;    /* disable postprocess output char */
+
+		tty->termios.c_lflag /* line discipline modes */
+			&= ~(ECHO     /* disable echo input characters */
+			| ECHONL      /* disable echo new line */
+			| ICANON      /* disable erase, kill, werase, and rprnt
+					 special characters */
+			| ISIG        /* disable interrupt, quit, and suspend
+					 special characters */
+			| IEXTEN);    /* disable non-POSIX special characters */
+	} /* CT_CYPHIDCOM: Application should handle this for device */
+
+	linechange = (priv->line_control != oldlines);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* if necessary, set lines */
+	if (linechange) {
+		priv->cmd_ctrl = 1;
+		cypress_write(tty, port, NULL, 0);
+	}
+} /* cypress_set_termios */
+
+
+/* returns amount of data still left in soft buffer */
+static unsigned int cypress_chars_in_buffer(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	unsigned int chars;
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	chars = kfifo_len(&priv->write_fifo);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	dev_dbg(&port->dev, "%s - returns %u\n", __func__, chars);
+	return chars;
+}
+
+
+static void cypress_throttle(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+
+	spin_lock_irq(&priv->lock);
+	priv->rx_flags = THROTTLED;
+	spin_unlock_irq(&priv->lock);
+}
+
+
+static void cypress_unthrottle(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	int actually_throttled, result;
+
+	spin_lock_irq(&priv->lock);
+	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
+	priv->rx_flags = 0;
+	spin_unlock_irq(&priv->lock);
+
+	if (!priv->comm_is_ok)
+		return;
+
+	if (actually_throttled) {
+		result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
+		if (result) {
+			dev_err(&port->dev, "%s - failed submitting read urb, "
+					"error %d\n", __func__, result);
+			cypress_set_dead(port);
+		}
+	}
+}
+
+
+static void cypress_read_int_callback(struct urb *urb)
+{
+	struct usb_serial_port *port = urb->context;
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	struct device *dev = &urb->dev->dev;
+	struct tty_struct *tty;
+	unsigned char *data = urb->transfer_buffer;
+	unsigned long flags;
+	char tty_flag = TTY_NORMAL;
+	int bytes = 0;
+	int result;
+	int i = 0;
+	int status = urb->status;
+
+	switch (status) {
+	case 0: /* success */
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		/* precursor to disconnect so just go away */
+		return;
+	case -EPIPE:
+		/* Can't call usb_clear_halt while in_interrupt */
+		fallthrough;
+	default:
+		/* something ugly is going on... */
+		dev_err(dev, "%s - unexpected nonzero read status received: %d\n",
+			__func__, status);
+		cypress_set_dead(port);
+		return;
+	}
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (priv->rx_flags & THROTTLED) {
+		dev_dbg(dev, "%s - now throttling\n", __func__);
+		priv->rx_flags |= ACTUALLY_THROTTLED;
+		spin_unlock_irqrestore(&priv->lock, flags);
+		return;
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	tty = tty_port_tty_get(&port->port);
+	if (!tty) {
+		dev_dbg(dev, "%s - bad tty pointer - exiting\n", __func__);
+		return;
+	}
+
+	spin_lock_irqsave(&priv->lock, flags);
+	result = urb->actual_length;
+	switch (priv->pkt_fmt) {
+	default:
+	case packet_format_1:
+		/* This is for the CY7C64013... */
+		priv->current_status = data[0] & 0xF8;
+		bytes = data[1] + 2;
+		i = 2;
+		break;
+	case packet_format_2:
+		/* This is for the CY7C63743... */
+		priv->current_status = data[0] & 0xF8;
+		bytes = (data[0] & 0x07) + 1;
+		i = 1;
+		break;
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+	if (result < bytes) {
+		dev_dbg(dev,
+			"%s - wrong packet size - received %d bytes but packet said %d bytes\n",
+			__func__, result, bytes);
+		goto continue_read;
+	}
+
+	usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	/* check to see if status has changed */
+	if (priv->current_status != priv->prev_status) {
+		u8 delta = priv->current_status ^ priv->prev_status;
+
+		if (delta & UART_MSR_MASK) {
+			if (delta & UART_CTS)
+				port->icount.cts++;
+			if (delta & UART_DSR)
+				port->icount.dsr++;
+			if (delta & UART_RI)
+				port->icount.rng++;
+			if (delta & UART_CD)
+				port->icount.dcd++;
+
+			wake_up_interruptible(&port->port.delta_msr_wait);
+		}
+
+		priv->prev_status = priv->current_status;
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* hangup, as defined in acm.c... this might be a bad place for it
+	 * though */
+	if (tty && !C_CLOCAL(tty) && !(priv->current_status & UART_CD)) {
+		dev_dbg(dev, "%s - calling hangup\n", __func__);
+		tty_hangup(tty);
+		goto continue_read;
+	}
+
+	/* There is one error bit... I'm assuming it is a parity error
+	 * indicator as the generic firmware will set this bit to 1 if a
+	 * parity error occurs.
+	 * I can not find reference to any other error events. */
+	spin_lock_irqsave(&priv->lock, flags);
+	if (priv->current_status & CYP_ERROR) {
+		spin_unlock_irqrestore(&priv->lock, flags);
+		tty_flag = TTY_PARITY;
+		dev_dbg(dev, "%s - Parity Error detected\n", __func__);
+	} else
+		spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* process read if there is data other than line status */
+	if (bytes > i) {
+		tty_insert_flip_string_fixed_flag(&port->port, data + i,
+				tty_flag, bytes - i);
+		tty_flip_buffer_push(&port->port);
+	}
+
+	spin_lock_irqsave(&priv->lock, flags);
+	/* control and status byte(s) are also counted */
+	priv->bytes_in += bytes;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+continue_read:
+	tty_kref_put(tty);
+
+	/* Continue trying to always read */
+
+	if (priv->comm_is_ok) {
+		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
+				usb_rcvintpipe(port->serial->dev,
+					port->interrupt_in_endpointAddress),
+				port->interrupt_in_urb->transfer_buffer,
+				port->interrupt_in_urb->transfer_buffer_length,
+				cypress_read_int_callback, port,
+				priv->read_urb_interval);
+		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
+		if (result && result != -EPERM) {
+			dev_err(dev, "%s - failed resubmitting read urb, error %d\n",
+				__func__, result);
+			cypress_set_dead(port);
+		}
+	}
+} /* cypress_read_int_callback */
+
+
+static void cypress_write_int_callback(struct urb *urb)
+{
+	struct usb_serial_port *port = urb->context;
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	struct device *dev = &urb->dev->dev;
+	int status = urb->status;
+
+	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);
+		priv->write_urb_in_use = 0;
+		return;
+	case -EPIPE:
+		/* Cannot call usb_clear_halt while in_interrupt */
+		fallthrough;
+	default:
+		dev_err(dev, "%s - unexpected nonzero write status received: %d\n",
+			__func__, status);
+		cypress_set_dead(port);
+		break;
+	}
+	priv->write_urb_in_use = 0;
+
+	/* send any buffered data */
+	cypress_send(port);
+}
+
+module_usb_serial_driver(serial_drivers, id_table_combined);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+module_param(stats, bool, 0644);
+MODULE_PARM_DESC(stats, "Enable statistics or not");
+module_param(interval, int, 0644);
+MODULE_PARM_DESC(interval, "Overrides interrupt interval");
+module_param(unstable_bauds, bool, 0644);
+MODULE_PARM_DESC(unstable_bauds, "Allow unstable baud rates");