[deliverable/linux.git] / drivers / usb / serial / metro-usb.c

/*
  Some of this code is credited to Linux USB open source files that are
  distributed with Linux.

  Copyright:	2007 Metrologic Instruments. All rights reserved.
  Copyright:	2011 Azimut Ltd. <http://azimutrzn.ru/>
*/

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/tty.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/moduleparam.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/uaccess.h>
#include <linux/usb/serial.h>

/* Version Information */
#define DRIVER_VERSION "v1.2.0.0"
#define DRIVER_DESC "Metrologic Instruments Inc. - USB-POS driver"

/* Product information. */
#define FOCUS_VENDOR_ID			0x0C2E
#define FOCUS_PRODUCT_ID		0x0720
#define FOCUS_PRODUCT_ID_UNI		0x0710

#define METROUSB_SET_REQUEST_TYPE	0x40
#define METROUSB_SET_MODEM_CTRL_REQUEST	10
#define METROUSB_SET_BREAK_REQUEST	0x40
#define METROUSB_MCR_NONE		0x08	/* Deactivate DTR and RTS. */
#define METROUSB_MCR_RTS		0x0a	/* Activate RTS. */
#define METROUSB_MCR_DTR		0x09	/* Activate DTR. */
#define WDR_TIMEOUT			5000	/* default urb timeout. */

/* Private data structure. */
struct metrousb_private {
	spinlock_t lock;
	int throttled;
	unsigned long control_state;
};

/* Device table list. */
static struct usb_device_id id_table[] = {
	{ USB_DEVICE(FOCUS_VENDOR_ID, FOCUS_PRODUCT_ID) },
	{ USB_DEVICE(FOCUS_VENDOR_ID, FOCUS_PRODUCT_ID_UNI) },
	{ }, /* Terminating entry. */
};
MODULE_DEVICE_TABLE(usb, id_table);

/* Input parameter constants. */
static bool debug;

/* Function prototypes. */
static void metrousb_cleanup(struct usb_serial_port *port);
static void metrousb_close(struct usb_serial_port *port);
static int  metrousb_open(struct tty_struct *tty, struct usb_serial_port *port);
static void metrousb_read_int_callback(struct urb *urb);
static void metrousb_shutdown(struct usb_serial *serial);
static int metrousb_startup(struct usb_serial *serial);
static void metrousb_throttle(struct tty_struct *tty);
static int metrousb_tiocmget(struct tty_struct *tty);
static int metrousb_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear);
static void metrousb_unthrottle(struct tty_struct *tty);

/* Driver structure. */
static struct usb_driver metrousb_driver = {
	.name =		"metro-usb",
	.probe =	usb_serial_probe,
	.disconnect =	usb_serial_disconnect,
	.id_table =	id_table
};

/* Device structure. */
static struct usb_serial_driver metrousb_device = {
	.driver = {
		.owner =	THIS_MODULE,
		.name =		"metro-usb",
	},
	.description		= "Metrologic USB to serial converter.",
	.id_table		= id_table,
	.num_ports		= 1,
	.open			= metrousb_open,
	.close			= metrousb_close,
	.read_int_callback	= metrousb_read_int_callback,
	.attach			= metrousb_startup,
	.release		= metrousb_shutdown,
	.throttle		= metrousb_throttle,
	.unthrottle		= metrousb_unthrottle,
	.tiocmget		= metrousb_tiocmget,
	.tiocmset		= metrousb_tiocmset,
};

static struct usb_serial_driver * const serial_drivers[] = {
	&metrousb_device,
	NULL,
};

/* ----------------------------------------------------------------------------------------------
  Description:
	Clean up any urbs and port information.

  Input:
	struct usb_serial_port *: pointer to a usb_serial_port structure.

  Output:
	int: Returns true (0) if successful, false otherwise.
*/
static void metrousb_cleanup(struct usb_serial_port *port)
{
	dbg("METRO-USB - %s - port number=%d", __FUNCTION__, port->number);

	if (port->serial->dev) {
		/* Shutdown any interrupt in urbs. */
		if (port->interrupt_in_urb) {
			usb_unlink_urb(port->interrupt_in_urb);
			usb_kill_urb(port->interrupt_in_urb);
		}
	}
}

/* ----------------------------------------------------------------------------------------------
  Description:
	Close the open serial port. Cleanup any open serial port information.

  Input:
	struct usb_serial_port *: pointer to a usb_serial_port structure.
	struct file *: pointer to a file structure.

  Output:
	int: Returns true (0) if successful, false otherwise.
*/
static void metrousb_close(struct usb_serial_port *port)
{
	dbg("METRO-USB - %s - port number=%d", __FUNCTION__, port->number);
	metrousb_cleanup(port);
}

/* ----------------------------------------------------------------------------------------------
  Description:
	Open the drivers serial port.

  Input:
	struct usb_serial_port *: pointer to a usb_serial_port structure.
	struct file *: pointer to a file structure.

  Output:
	int: Returns true (0) if successful, false otherwise.
*/
static int metrousb_open(struct tty_struct *tty, struct usb_serial_port *port)
{
	struct usb_serial *serial = port->serial;
	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
	unsigned long flags = 0;
	int result = 0;

	dbg("METRO-USB - %s - port number=%d", __FUNCTION__, port->number);

	/* Make sure the urb is initialized. */
	if (!port->interrupt_in_urb) {
		dbg("METRO-USB - %s - interrupt urb not initialized for port number=%d", __FUNCTION__, port->number);
		return -ENODEV;
	}

	/* Set the private data information for the port. */
	spin_lock_irqsave(&metro_priv->lock, flags);
	metro_priv->control_state = 0;
	metro_priv->throttled = 0;
	spin_unlock_irqrestore(&metro_priv->lock, flags);

	/*
	 * Force low_latency on so that our tty_push actually forces the data
	 * through, otherwise it is scheduled, and with high data rates (like
	 * with OHCI) data can get lost.
	 */
	if (tty)
		tty->low_latency = 1;

	/* Clear the urb pipe. */
	usb_clear_halt(serial->dev, port->interrupt_in_urb->pipe);

	/* 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,
			   metrousb_read_int_callback, port, 1);
	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);

	if (result) {
		dbg("METRO-USB - %s - failed submitting interrupt in urb for port number=%d, error code=%d"
			, __FUNCTION__, port->number, result);
		goto exit;
	}

	dbg("METRO-USB - %s - port open for port number=%d", __FUNCTION__, port->number);
exit:
	return result;
}

/* ----------------------------------------------------------------------------------------------
  Description:
	Read the port from the read interrupt.

  Input:
	struct urb *: urb structure to get data.
	struct pt_regs *: pt_regs structure.

  Output:
	None:
*/
static void metrousb_read_int_callback(struct urb *urb)
{
	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
	struct tty_struct *tty;
	unsigned char *data = urb->transfer_buffer;
	int throttled = 0;
	int result = 0;
	unsigned long flags = 0;

	dbg("METRO-USB - %s - port number=%d", __FUNCTION__, port->number);

	switch (urb->status) {
	case 0:
		/* Success status, read from the port. */
		break;
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
		/* urb has been terminated. */
		dbg("METRO-USB - %s - urb shutting down, port number=%d, error code=%d",
			__FUNCTION__, port->number, result);
		return;
	default:
		dbg("METRO-USB - %s - non-zero urb received, port number=%d, error code=%d",
			__FUNCTION__, port->number, result);
		goto exit;
	}


	/* Set the data read from the usb port into the serial port buffer. */
	tty = tty_port_tty_get(&port->port);
	if (!tty) {
		dbg("%s - bad tty pointer - exiting", __func__);
		return;
	}

	if (tty && urb->actual_length) {
		/* Loop through the data copying each byte to the tty layer. */
		tty_insert_flip_string(tty, data, urb->actual_length);

		/* Force the data to the tty layer. */
		tty_flip_buffer_push(tty);
	}
	tty_kref_put(tty);

	/* Set any port variables. */
	spin_lock_irqsave(&metro_priv->lock, flags);
	throttled = metro_priv->throttled;
	spin_unlock_irqrestore(&metro_priv->lock, flags);

	/* Continue trying to read if set. */
	if (!throttled) {
		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,
				 metrousb_read_int_callback, port, 1);

		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);

		if (result) {
			dbg("METRO-USB - %s - failed submitting interrupt in urb for port number=%d, error code=%d",
				__FUNCTION__, port->number, result);
		}
	}
	return;

exit:
	/* Try to resubmit the urb. */
	result = usb_submit_urb(urb, GFP_ATOMIC);
	if (result) {
		dbg("METRO-USB - %s - failed submitting interrupt in urb for port number=%d, error code=%d",
			__FUNCTION__, port->number, result);
	}
}

/* ----------------------------------------------------------------------------------------------
  Description:
	Set the modem control state for the entered serial port.

  Input:
	struct usb_serial_port *: pointer to a usb_serial_port structure.
	unsigned int: control state value to set.

  Output:
	int: Returns true (0) if successful, false otherwise.
*/
static int metrousb_set_modem_ctrl(struct usb_serial *serial, unsigned int control_state)
{
	int retval = 0;
	unsigned char mcr = METROUSB_MCR_NONE;

	dbg("METRO-USB - %s - control state=%d", __FUNCTION__, control_state);

	/* Set the modem control value. */
	if (control_state & TIOCM_DTR)
		mcr |= METROUSB_MCR_DTR;
	if (control_state & TIOCM_RTS)
		mcr |= METROUSB_MCR_RTS;

	/* Send the command to the usb port. */
	retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
				METROUSB_SET_REQUEST_TYPE, METROUSB_SET_MODEM_CTRL_REQUEST,
				control_state, 0, NULL, 0, WDR_TIMEOUT);
	if (retval < 0)
		dbg("METRO-USB - %s - set modem ctrl=0x%x failed, error code=%d", __FUNCTION__, mcr, retval);

	return retval;
}


/* ----------------------------------------------------------------------------------------------
  Description:
	Shutdown the driver.

  Input:
	struct usb_serial *: pointer to a usb-serial structure.

  Output:
	int: Returns true (0) if successful, false otherwise.
*/
static void metrousb_shutdown(struct usb_serial *serial)
{
	int i = 0;

	dbg("METRO-USB - %s", __FUNCTION__);

	/* Stop reading and writing on all ports. */
	for (i = 0; i < serial->num_ports; ++i) {
		/* Close any open urbs. */
		metrousb_cleanup(serial->port[i]);

		/* Free memory. */
		kfree(usb_get_serial_port_data(serial->port[i]));
		usb_set_serial_port_data(serial->port[i], NULL);

		dbg("METRO-USB - %s - freed port number=%d", __FUNCTION__, serial->port[i]->number);
	}
}

/* ----------------------------------------------------------------------------------------------
  Description:
	Startup the driver.

  Input:
	struct usb_serial *: pointer to a usb-serial structure.

  Output:
	int: Returns true (0) if successful, false otherwise.
*/
static int metrousb_startup(struct usb_serial *serial)
{
	struct metrousb_private *metro_priv;
	struct usb_serial_port *port;
	int i = 0;

	dbg("METRO-USB - %s", __FUNCTION__);

	/* Loop through the serial ports setting up the private structures.
	 * Currently we only use one port. */
	for (i = 0; i < serial->num_ports; ++i) {
		port = serial->port[i];

		/* Declare memory. */
		metro_priv = kmalloc(sizeof(struct metrousb_private), GFP_KERNEL);
		if (!metro_priv)
			return -ENOMEM;

		/* Clear memory. */
		memset(metro_priv, 0x00, sizeof(struct metrousb_private));

		/* Initialize memory. */
		spin_lock_init(&metro_priv->lock);
		usb_set_serial_port_data(port, metro_priv);

		dbg("METRO-USB - %s - port number=%d.", __FUNCTION__, port->number);
	}

	return 0;
}

/* ----------------------------------------------------------------------------------------------
  Description:
	Set the serial port throttle to stop reading from the port.

  Input:
	struct usb_serial_port *: pointer to a usb_serial_port structure.

  Output:
	None:
*/
static void metrousb_throttle(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
	unsigned long flags = 0;

	dbg("METRO-USB - %s - port number=%d", __FUNCTION__, port->number);

	/* Set the private information for the port to stop reading data. */
	spin_lock_irqsave(&metro_priv->lock, flags);
	metro_priv->throttled = 1;
	spin_unlock_irqrestore(&metro_priv->lock, flags);
}

/* ----------------------------------------------------------------------------------------------
  Description:
	Get the serial port control line states.

  Input:
	struct usb_serial_port *: pointer to a usb_serial_port structure.
	struct file *: pointer to a file structure.

  Output:
	int: Returns the state of the control lines.
*/
static int metrousb_tiocmget(struct tty_struct *tty)
{
	unsigned long control_state = 0;
	struct usb_serial_port *port = tty->driver_data;
	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
	unsigned long flags = 0;

	dbg("METRO-USB - %s - port number=%d", __FUNCTION__, port->number);

	spin_lock_irqsave(&metro_priv->lock, flags);
	control_state = metro_priv->control_state;
	spin_unlock_irqrestore(&metro_priv->lock, flags);

	return control_state;
}

/* ----------------------------------------------------------------------------------------------
  Description:
	Set the serial port control line states.

  Input:
	struct usb_serial_port *: pointer to a usb_serial_port structure.
	struct file *: pointer to a file structure.
	unsigned int: line state to set.
	unsigned int: line state to clear.

  Output:
	int: Returns the state of the control lines.
*/
static int metrousb_tiocmset(struct tty_struct *tty,
			     unsigned int set, unsigned int clear)
{
	struct usb_serial_port *port = tty->driver_data;
	struct usb_serial *serial = port->serial;
	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
	unsigned long flags = 0;
	unsigned long control_state = 0;

	dbg("METRO-USB - %s - port number=%d, set=%d, clear=%d", __FUNCTION__, port->number, set, clear);

	spin_lock_irqsave(&metro_priv->lock, flags);
	control_state = metro_priv->control_state;

	/* Set the RTS and DTR values. */
	if (set & TIOCM_RTS)
		control_state |= TIOCM_RTS;
	if (set & TIOCM_DTR)
		control_state |= TIOCM_DTR;
	if (clear & TIOCM_RTS)
		control_state &= ~TIOCM_RTS;
	if (clear & TIOCM_DTR)
		control_state &= ~TIOCM_DTR;

	metro_priv->control_state = control_state;
	spin_unlock_irqrestore(&metro_priv->lock, flags);
	return metrousb_set_modem_ctrl(serial, control_state);
}

/* ----------------------------------------------------------------------------------------------
  Description:
	Set the serial port unthrottle to resume reading from the port.

  Input:
	struct usb_serial_port *: pointer to a usb_serial_port structure.

  Output:
	None:
*/
static void metrousb_unthrottle(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
	unsigned long flags = 0;
	int result = 0;

	dbg("METRO-USB - %s - port number=%d", __FUNCTION__, port->number);

	/* Set the private information for the port to resume reading data. */
	spin_lock_irqsave(&metro_priv->lock, flags);
	metro_priv->throttled = 0;
	spin_unlock_irqrestore(&metro_priv->lock, flags);

	/* Submit the urb to read from the port. */
	port->interrupt_in_urb->dev = port->serial->dev;
	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
	if (result) {
		dbg("METRO-USB - %s - failed submitting interrupt in urb for port number=%d, error code=%d",
			__FUNCTION__, port->number, result);
	}
}

module_usb_serial_driver(metrousb_driver, serial_drivers);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Philip Nicastro");
MODULE_AUTHOR("Aleksey Babahin <tamerlan311@gmail.com>");
MODULE_DESCRIPTION(DRIVER_DESC);

/* Module input parameters */
module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Print debug info (bool 1=on, 0=off)");
Commit	Line	Data
43d186fe	1	/*
d4cbd6e9 GKH	2	Some of this code is credited to Linux USB open source files that are
d4cbd6e9 GKH	3	distributed with Linux.
43d186fe AB	4
	5	Copyright: 2007 Metrologic Instruments. All rights reserved.
	6	Copyright: 2011 Azimut Ltd. <http://azimutrzn.ru/>
43d186fe AB	7	*/
	8
	9	#include <linux/kernel.h>
	10	#include <linux/init.h>
	11	#include <linux/tty.h>
	12	#include <linux/module.h>
	13	#include <linux/usb.h>
	14	#include <linux/errno.h>
	15	#include <linux/slab.h>
	16	#include <linux/tty_driver.h>
	17	#include <linux/tty_flip.h>
	18	#include <linux/moduleparam.h>
	19	#include <linux/spinlock.h>
43d186fe	20	#include <linux/errno.h>
d4cbd6e9	21	#include <linux/uaccess.h>
43d186fe AB	22	#include <linux/usb/serial.h>
	23
	24	/* Version Information */
	25	#define DRIVER_VERSION "v1.2.0.0"
	26	#define DRIVER_DESC "Metrologic Instruments Inc. - USB-POS driver"
	27
159d4d8d GKH	28	/* Product information. */
	29	#define FOCUS_VENDOR_ID 0x0C2E
	30	#define FOCUS_PRODUCT_ID 0x0720
	31	#define FOCUS_PRODUCT_ID_UNI 0x0710
	32
	33	#define METROUSB_SET_REQUEST_TYPE 0x40
	34	#define METROUSB_SET_MODEM_CTRL_REQUEST 10
	35	#define METROUSB_SET_BREAK_REQUEST 0x40
	36	#define METROUSB_MCR_NONE 0x08 /* Deactivate DTR and RTS. */
	37	#define METROUSB_MCR_RTS 0x0a /* Activate RTS. */
	38	#define METROUSB_MCR_DTR 0x09 /* Activate DTR. */
d4cbd6e9	39	#define WDR_TIMEOUT 5000 /* default urb timeout. */
159d4d8d GKH	40
	41	/* Private data structure. */
	42	struct metrousb_private {
	43	spinlock_t lock;
	44	int throttled;
	45	unsigned long control_state;
	46	};
	47
43d186fe	48	/* Device table list. */
d4cbd6e9	49	static struct usb_device_id id_table[] = {
43d186fe AB	50	{ USB_DEVICE(FOCUS_VENDOR_ID, FOCUS_PRODUCT_ID) },
43d186fe AB	51	{ USB_DEVICE(FOCUS_VENDOR_ID, FOCUS_PRODUCT_ID_UNI) },
43d186fe AB	52	{ }, /* Terminating entry. */
	53	};
	54	MODULE_DEVICE_TABLE(usb, id_table);
	55
	56	/* Input parameter constants. */
fdac0f64	57	static bool debug;
43d186fe AB	58
43d186fe AB	59	/* Function prototypes. */
d4cbd6e9 GKH	60	static void metrousb_cleanup(struct usb_serial_port *port);
	61	static void metrousb_close(struct usb_serial_port *port);
	62	static int metrousb_open(struct tty_struct tty, struct usb_serial_port port);
	63	static void metrousb_read_int_callback(struct urb *urb);
	64	static void metrousb_shutdown(struct usb_serial *serial);
	65	static int metrousb_startup(struct usb_serial *serial);
43d186fe AB	66	static void metrousb_throttle(struct tty_struct *tty);
	67	static int metrousb_tiocmget(struct tty_struct *tty);
	68	static int metrousb_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear);
	69	static void metrousb_unthrottle(struct tty_struct *tty);
	70
	71	/* Driver structure. */
	72	static struct usb_driver metrousb_driver = {
	73	.name = "metro-usb",
	74	.probe = usb_serial_probe,
	75	.disconnect = usb_serial_disconnect,
	76	.id_table = id_table
	77	};
	78
	79	/* Device structure. */
	80	static struct usb_serial_driver metrousb_device = {
	81	.driver = {
	82	.owner = THIS_MODULE,
	83	.name = "metro-usb",
	84	},
d4cbd6e9 GKH	85	.description = "Metrologic USB to serial converter.",
	86	.id_table = id_table,
	87	.num_ports = 1,
	88	.open = metrousb_open,
	89	.close = metrousb_close,
	90	.read_int_callback = metrousb_read_int_callback,
	91	.attach = metrousb_startup,
	92	.release = metrousb_shutdown,
	93	.throttle = metrousb_throttle,
	94	.unthrottle = metrousb_unthrottle,
	95	.tiocmget = metrousb_tiocmget,
	96	.tiocmset = metrousb_tiocmset,
43d186fe AB	97	};
43d186fe AB	98
11a4f400 GKH	99	static struct usb_serial_driver * const serial_drivers[] = {
	100	&metrousb_device,
	101	NULL,
	102	};
	103
43d186fe AB	104	/* ----------------------------------------------------------------------------------------------
	105	Description:
	106	Clean up any urbs and port information.
	107
	108	Input:
	109	struct usb_serial_port *: pointer to a usb_serial_port structure.
	110
	111	Output:
	112	int: Returns true (0) if successful, false otherwise.
	113	*/
d4cbd6e9	114	static void metrousb_cleanup(struct usb_serial_port *port)
43d186fe AB	115	{
	116	dbg("METRO-USB - %s - port number=%d", __FUNCTION__, port->number);
	117
	118	if (port->serial->dev) {
	119	/* Shutdown any interrupt in urbs. */
	120	if (port->interrupt_in_urb) {
	121	usb_unlink_urb(port->interrupt_in_urb);
	122	usb_kill_urb(port->interrupt_in_urb);
	123	}
43d186fe AB	124	}
	125	}
	126
	127	/* ----------------------------------------------------------------------------------------------
	128	Description:
	129	Close the open serial port. Cleanup any open serial port information.
	130
	131	Input:
	132	struct usb_serial_port *: pointer to a usb_serial_port structure.
	133	struct file *: pointer to a file structure.
	134
	135	Output:
	136	int: Returns true (0) if successful, false otherwise.
	137	*/
d4cbd6e9	138	static void metrousb_close(struct usb_serial_port *port)
43d186fe AB	139	{
	140	dbg("METRO-USB - %s - port number=%d", __FUNCTION__, port->number);
	141	metrousb_cleanup(port);
	142	}
	143
43d186fe AB	144	/* ----------------------------------------------------------------------------------------------
	145	Description:
	146	Open the drivers serial port.
	147
	148	Input:
	149	struct usb_serial_port *: pointer to a usb_serial_port structure.
	150	struct file *: pointer to a file structure.
	151
	152	Output:
	153	int: Returns true (0) if successful, false otherwise.
	154	*/
d4cbd6e9	155	static int metrousb_open(struct tty_struct tty, struct usb_serial_port port)
43d186fe AB	156	{
	157	struct usb_serial *serial = port->serial;
	158	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
	159	unsigned long flags = 0;
	160	int result = 0;
	161
	162	dbg("METRO-USB - %s - port number=%d", __FUNCTION__, port->number);
	163
	164	/* Make sure the urb is initialized. */
	165	if (!port->interrupt_in_urb) {
	166	dbg("METRO-USB - %s - interrupt urb not initialized for port number=%d", __FUNCTION__, port->number);
	167	return -ENODEV;
	168	}
	169
	170	/* Set the private data information for the port. */
	171	spin_lock_irqsave(&metro_priv->lock, flags);
	172	metro_priv->control_state = 0;
	173	metro_priv->throttled = 0;
	174	spin_unlock_irqrestore(&metro_priv->lock, flags);
	175
	176	/*
	177	* Force low_latency on so that our tty_push actually forces the data
	178	* through, otherwise it is scheduled, and with high data rates (like
	179	* with OHCI) data can get lost.
	180	*/
d4cbd6e9	181	if (tty)
43d186fe	182	tty->low_latency = 1;
43d186fe AB	183
	184	/* Clear the urb pipe. */
	185	usb_clear_halt(serial->dev, port->interrupt_in_urb->pipe);
	186
	187	/* Start reading from the device */
d4cbd6e9 GKH	188	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
d4cbd6e9 GKH	189	usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
43d186fe AB	190	port->interrupt_in_urb->transfer_buffer,
	191	port->interrupt_in_urb->transfer_buffer_length,
	192	metrousb_read_int_callback, port, 1);
	193	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
	194
	195	if (result) {
	196	dbg("METRO-USB - %s - failed submitting interrupt in urb for port number=%d, error code=%d"
	197	, __FUNCTION__, port->number, result);
	198	goto exit;
	199	}
	200
	201	dbg("METRO-USB - %s - port open for port number=%d", __FUNCTION__, port->number);
	202	exit:
	203	return result;
	204	}
	205
	206	/* ----------------------------------------------------------------------------------------------
	207	Description:
	208	Read the port from the read interrupt.
	209
	210	Input:
	211	struct urb *: urb structure to get data.
	212	struct pt_regs *: pt_regs structure.
	213
	214	Output:
	215	None:
	216	*/
d4cbd6e9	217	static void metrousb_read_int_callback(struct urb *urb)
43d186fe AB	218	{
	219	struct usb_serial_port port = (struct usb_serial_port )urb->context;
	220	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
	221	struct tty_struct *tty;
	222	unsigned char *data = urb->transfer_buffer;
	223	int throttled = 0;
	224	int result = 0;
	225	unsigned long flags = 0;
	226
	227	dbg("METRO-USB - %s - port number=%d", __FUNCTION__, port->number);
	228
	229	switch (urb->status) {
d4cbd6e9 GKH	230	case 0:
	231	/* Success status, read from the port. */
	232	break;
	233	case -ECONNRESET:
	234	case -ENOENT:
	235	case -ESHUTDOWN:
	236	/* urb has been terminated. */
	237	dbg("METRO-USB - %s - urb shutting down, port number=%d, error code=%d",
	238	__FUNCTION__, port->number, result);
	239	return;
	240	default:
	241	dbg("METRO-USB - %s - non-zero urb received, port number=%d, error code=%d",
	242	__FUNCTION__, port->number, result);
	243	goto exit;
43d186fe AB	244	}
	245
	246
	247	/* Set the data read from the usb port into the serial port buffer. */
	248	tty = tty_port_tty_get(&port->port);
	249	if (!tty) {
	250	dbg("%s - bad tty pointer - exiting", __func__);
	251	return;
	252	}
	253
	254	if (tty && urb->actual_length) {
d4cbd6e9	255	/* Loop through the data copying each byte to the tty layer. */
43d186fe AB	256	tty_insert_flip_string(tty, data, urb->actual_length);
43d186fe AB	257
d4cbd6e9	258	/* Force the data to the tty layer. */
43d186fe AB	259	tty_flip_buffer_push(tty);
	260	}
	261	tty_kref_put(tty);
	262
	263	/* Set any port variables. */
	264	spin_lock_irqsave(&metro_priv->lock, flags);
	265	throttled = metro_priv->throttled;
	266	spin_unlock_irqrestore(&metro_priv->lock, flags);
	267
	268	/* Continue trying to read if set. */
	269	if (!throttled) {
d4cbd6e9 GKH	270	usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
	271	usb_rcvintpipe(port->serial->dev, port->interrupt_in_endpointAddress),
	272	port->interrupt_in_urb->transfer_buffer,
	273	port->interrupt_in_urb->transfer_buffer_length,
	274	metrousb_read_int_callback, port, 1);
43d186fe AB	275
	276	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
	277
	278	if (result) {
	279	dbg("METRO-USB - %s - failed submitting interrupt in urb for port number=%d, error code=%d",
	280	__FUNCTION__, port->number, result);
	281	}
	282	}
	283	return;
	284
	285	exit:
	286	/* Try to resubmit the urb. */
d4cbd6e9	287	result = usb_submit_urb(urb, GFP_ATOMIC);
43d186fe AB	288	if (result) {
	289	dbg("METRO-USB - %s - failed submitting interrupt in urb for port number=%d, error code=%d",
	290	__FUNCTION__, port->number, result);
	291	}
	292	}
	293
	294	/* ----------------------------------------------------------------------------------------------
	295	Description:
	296	Set the modem control state for the entered serial port.
	297
	298	Input:
	299	struct usb_serial_port *: pointer to a usb_serial_port structure.
	300	unsigned int: control state value to set.
	301
	302	Output:
	303	int: Returns true (0) if successful, false otherwise.
	304	*/
	305	static int metrousb_set_modem_ctrl(struct usb_serial *serial, unsigned int control_state)
	306	{
	307	int retval = 0;
	308	unsigned char mcr = METROUSB_MCR_NONE;
	309
	310	dbg("METRO-USB - %s - control state=%d", __FUNCTION__, control_state);
	311
	312	/* Set the modem control value. */
	313	if (control_state & TIOCM_DTR)
	314	mcr \|= METROUSB_MCR_DTR;
	315	if (control_state & TIOCM_RTS)
	316	mcr \|= METROUSB_MCR_RTS;
	317
	318	/* Send the command to the usb port. */
	319	retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
	320	METROUSB_SET_REQUEST_TYPE, METROUSB_SET_MODEM_CTRL_REQUEST,
	321	control_state, 0, NULL, 0, WDR_TIMEOUT);
	322	if (retval < 0)
	323	dbg("METRO-USB - %s - set modem ctrl=0x%x failed, error code=%d", __FUNCTION__, mcr, retval);
	324
	325	return retval;
	326	}
	327
	328
	329	/* ----------------------------------------------------------------------------------------------
	330	Description:
	331	Shutdown the driver.
	332
	333	Input:
	334	struct usb_serial *: pointer to a usb-serial structure.
	335
	336	Output:
	337	int: Returns true (0) if successful, false otherwise.
	338	*/
d4cbd6e9	339	static void metrousb_shutdown(struct usb_serial *serial)
43d186fe AB	340	{
	341	int i = 0;
	342
	343	dbg("METRO-USB - %s", __FUNCTION__);
	344
	345	/* Stop reading and writing on all ports. */
d4cbd6e9	346	for (i = 0; i < serial->num_ports; ++i) {
43d186fe AB	347	/* Close any open urbs. */
	348	metrousb_cleanup(serial->port[i]);
	349
	350	/* Free memory. */
	351	kfree(usb_get_serial_port_data(serial->port[i]));
	352	usb_set_serial_port_data(serial->port[i], NULL);
	353
	354	dbg("METRO-USB - %s - freed port number=%d", __FUNCTION__, serial->port[i]->number);
	355	}
	356	}
	357
	358	/* ----------------------------------------------------------------------------------------------
	359	Description:
	360	Startup the driver.
	361
	362	Input:
	363	struct usb_serial *: pointer to a usb-serial structure.
	364
	365	Output:
	366	int: Returns true (0) if successful, false otherwise.
	367	*/
	368	static int metrousb_startup(struct usb_serial *serial)
	369	{
	370	struct metrousb_private *metro_priv;
	371	struct usb_serial_port *port;
	372	int i = 0;
	373
	374	dbg("METRO-USB - %s", __FUNCTION__);
	375
	376	/* Loop through the serial ports setting up the private structures.
	377	* Currently we only use one port. */
	378	for (i = 0; i < serial->num_ports; ++i) {
	379	port = serial->port[i];
	380
	381	/* Declare memory. */
d4cbd6e9	382	metro_priv = kmalloc(sizeof(struct metrousb_private), GFP_KERNEL);
43d186fe AB	383	if (!metro_priv)
	384	return -ENOMEM;
	385
	386	/* Clear memory. */
d4cbd6e9	387	memset(metro_priv, 0x00, sizeof(struct metrousb_private));
43d186fe AB	388
	389	/* Initialize memory. */
	390	spin_lock_init(&metro_priv->lock);
	391	usb_set_serial_port_data(port, metro_priv);
	392
	393	dbg("METRO-USB - %s - port number=%d.", __FUNCTION__, port->number);
	394	}
	395
	396	return 0;
	397	}
	398
	399	/* ----------------------------------------------------------------------------------------------
	400	Description:
	401	Set the serial port throttle to stop reading from the port.
	402
	403	Input:
	404	struct usb_serial_port *: pointer to a usb_serial_port structure.
	405
	406	Output:
	407	None:
	408	*/
d4cbd6e9	409	static void metrousb_throttle(struct tty_struct *tty)
43d186fe AB	410	{
	411	struct usb_serial_port *port = tty->driver_data;
	412	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
	413	unsigned long flags = 0;
	414
	415	dbg("METRO-USB - %s - port number=%d", __FUNCTION__, port->number);
	416
	417	/* Set the private information for the port to stop reading data. */
	418	spin_lock_irqsave(&metro_priv->lock, flags);
	419	metro_priv->throttled = 1;
	420	spin_unlock_irqrestore(&metro_priv->lock, flags);
	421	}
	422
	423	/* ----------------------------------------------------------------------------------------------
	424	Description:
	425	Get the serial port control line states.
	426
	427	Input:
	428	struct usb_serial_port *: pointer to a usb_serial_port structure.
	429	struct file *: pointer to a file structure.
	430
	431	Output:
	432	int: Returns the state of the control lines.
	433	*/
d4cbd6e9	434	static int metrousb_tiocmget(struct tty_struct *tty)
43d186fe AB	435	{
	436	unsigned long control_state = 0;
	437	struct usb_serial_port *port = tty->driver_data;
	438	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
	439	unsigned long flags = 0;
	440
	441	dbg("METRO-USB - %s - port number=%d", __FUNCTION__, port->number);
	442
	443	spin_lock_irqsave(&metro_priv->lock, flags);
	444	control_state = metro_priv->control_state;
	445	spin_unlock_irqrestore(&metro_priv->lock, flags);
	446
	447	return control_state;
	448	}
	449
	450	/* ----------------------------------------------------------------------------------------------
	451	Description:
	452	Set the serial port control line states.
	453
	454	Input:
	455	struct usb_serial_port *: pointer to a usb_serial_port structure.
	456	struct file *: pointer to a file structure.
	457	unsigned int: line state to set.
	458	unsigned int: line state to clear.
	459
	460	Output:
	461	int: Returns the state of the control lines.
	462	*/
d4cbd6e9 GKH	463	static int metrousb_tiocmset(struct tty_struct *tty,
d4cbd6e9 GKH	464	unsigned int set, unsigned int clear)
43d186fe AB	465	{
	466	struct usb_serial_port *port = tty->driver_data;
	467	struct usb_serial *serial = port->serial;
	468	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
	469	unsigned long flags = 0;
	470	unsigned long control_state = 0;
	471
	472	dbg("METRO-USB - %s - port number=%d, set=%d, clear=%d", __FUNCTION__, port->number, set, clear);
	473
	474	spin_lock_irqsave(&metro_priv->lock, flags);
	475	control_state = metro_priv->control_state;
	476
d4cbd6e9	477	/* Set the RTS and DTR values. */
43d186fe AB	478	if (set & TIOCM_RTS)
	479	control_state \|= TIOCM_RTS;
	480	if (set & TIOCM_DTR)
	481	control_state \|= TIOCM_DTR;
	482	if (clear & TIOCM_RTS)
	483	control_state &= ~TIOCM_RTS;
	484	if (clear & TIOCM_DTR)
	485	control_state &= ~TIOCM_DTR;
	486
	487	metro_priv->control_state = control_state;
	488	spin_unlock_irqrestore(&metro_priv->lock, flags);
	489	return metrousb_set_modem_ctrl(serial, control_state);
	490	}
	491
	492	/* ----------------------------------------------------------------------------------------------
	493	Description:
	494	Set the serial port unthrottle to resume reading from the port.
	495
	496	Input:
	497	struct usb_serial_port *: pointer to a usb_serial_port structure.
	498
	499	Output:
	500	None:
	501	*/
d4cbd6e9	502	static void metrousb_unthrottle(struct tty_struct *tty)
43d186fe AB	503	{
	504	struct usb_serial_port *port = tty->driver_data;
	505	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
	506	unsigned long flags = 0;
	507	int result = 0;
	508
	509	dbg("METRO-USB - %s - port number=%d", __FUNCTION__, port->number);
	510
	511	/* Set the private information for the port to resume reading data. */
	512	spin_lock_irqsave(&metro_priv->lock, flags);
	513	metro_priv->throttled = 0;
	514	spin_unlock_irqrestore(&metro_priv->lock, flags);
	515
	516	/* Submit the urb to read from the port. */
	517	port->interrupt_in_urb->dev = port->serial->dev;
	518	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
	519	if (result) {
	520	dbg("METRO-USB - %s - failed submitting interrupt in urb for port number=%d, error code=%d",
	521	__FUNCTION__, port->number, result);
	522	}
	523	}
	524
1935e357 GKH	525	module_usb_serial_driver(metrousb_driver, serial_drivers);
1935e357 GKH	526
43d186fe	527	MODULE_LICENSE("GPL");
d4cbd6e9 GKH	528	MODULE_AUTHOR("Philip Nicastro");
	529	MODULE_AUTHOR("Aleksey Babahin <tamerlan311@gmail.com>");
	530	MODULE_DESCRIPTION(DRIVER_DESC);
43d186fe AB	531
	532	/* Module input parameters */
	533	module_param(debug, bool, S_IRUGO \| S_IWUSR);
	534	MODULE_PARM_DESC(debug, "Print debug info (bool 1=on, 0=off)");