xref: /linux/drivers/usb/serial/quatech2.c (revision c75c5ab575af7db707689cdbb5a5c458e9a034bb)
1 /*
2  * usb-serial driver for Quatech USB 2 devices
3  *
4  * Copyright (C) 2012 Bill Pemberton (wfp5p@virginia.edu)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License version 2
8  * as published by the Free Software Foundation.
9  *
10  *
11  *  These devices all have only 1 bulk in and 1 bulk out that is shared
12  *  for all serial ports.
13  *
14  */
15 
16 #include <asm/unaligned.h>
17 #include <linux/errno.h>
18 #include <linux/init.h>
19 #include <linux/slab.h>
20 #include <linux/tty.h>
21 #include <linux/tty_driver.h>
22 #include <linux/tty_flip.h>
23 #include <linux/module.h>
24 #include <linux/serial.h>
25 #include <linux/usb.h>
26 #include <linux/usb/serial.h>
27 #include <linux/serial_reg.h>
28 #include <linux/uaccess.h>
29 
30 /* default urb timeout for usb operations */
31 #define QT2_USB_TIMEOUT USB_CTRL_SET_TIMEOUT
32 
33 #define QT_OPEN_CLOSE_CHANNEL       0xca
34 #define QT_SET_GET_DEVICE           0xc2
35 #define QT_SET_GET_REGISTER         0xc0
36 #define QT_GET_SET_PREBUF_TRIG_LVL  0xcc
37 #define QT_SET_ATF                  0xcd
38 #define QT_TRANSFER_IN              0xc0
39 #define QT_HW_FLOW_CONTROL_MASK     0xc5
40 #define QT_SW_FLOW_CONTROL_MASK     0xc6
41 #define QT2_BREAK_CONTROL	    0xc8
42 #define QT2_GET_SET_UART            0xc1
43 #define QT2_FLUSH_DEVICE	    0xc4
44 #define QT2_GET_SET_QMCR            0xe1
45 #define QT2_QMCR_RS232              0x40
46 #define QT2_QMCR_RS422              0x10
47 
48 #define  SERIAL_CRTSCTS ((UART_MCR_RTS << 8) | UART_MSR_CTS)
49 
50 #define  SERIAL_EVEN_PARITY         (UART_LCR_PARITY | UART_LCR_EPAR)
51 
52 /* status bytes for the device */
53 #define QT2_CONTROL_BYTE    0x1b
54 #define QT2_LINE_STATUS     0x00  /* following 1 byte is line status */
55 #define QT2_MODEM_STATUS    0x01  /* following 1 byte is modem status */
56 #define QT2_XMIT_HOLD       0x02  /* following 2 bytes are ?? */
57 #define QT2_CHANGE_PORT     0x03  /* following 1 byte is port to change to */
58 #define QT2_REC_FLUSH       0x04  /* no following info */
59 #define QT2_XMIT_FLUSH      0x05  /* no following info */
60 #define QT2_CONTROL_ESCAPE  0xff  /* pass through previous 2 control bytes */
61 
62 #define  MAX_BAUD_RATE              921600
63 #define  DEFAULT_BAUD_RATE          9600
64 
65 #define QT2_WRITE_BUFFER_SIZE   512  /* size of write buffer */
66 #define QT2_WRITE_CONTROL_SIZE  5    /* control bytes used for a write */
67 
68 #define DRIVER_DESC "Quatech 2nd gen USB to Serial Driver"
69 
70 #define	USB_VENDOR_ID_QUATECH	0x061d
71 #define QUATECH_SSU2_100	0xC120	/* RS232 single port */
72 #define QUATECH_DSU2_100	0xC140	/* RS232 dual port */
73 #define QUATECH_DSU2_400	0xC150	/* RS232/422/485 dual port */
74 #define QUATECH_QSU2_100	0xC160	/* RS232 four port */
75 #define QUATECH_QSU2_400	0xC170	/* RS232/422/485 four port */
76 #define QUATECH_ESU2_100	0xC1A0	/* RS232 eight port */
77 #define QUATECH_ESU2_400	0xC180	/* RS232/422/485 eight port */
78 
79 struct qt2_device_detail {
80 	int product_id;
81 	int num_ports;
82 };
83 
84 #define QT_DETAILS(prod, ports)	\
85 	.product_id = (prod),   \
86 	.num_ports = (ports)
87 
88 static const struct qt2_device_detail qt2_device_details[] = {
89 	{QT_DETAILS(QUATECH_SSU2_100, 1)},
90 	{QT_DETAILS(QUATECH_DSU2_400, 2)},
91 	{QT_DETAILS(QUATECH_DSU2_100, 2)},
92 	{QT_DETAILS(QUATECH_QSU2_400, 4)},
93 	{QT_DETAILS(QUATECH_QSU2_100, 4)},
94 	{QT_DETAILS(QUATECH_ESU2_400, 8)},
95 	{QT_DETAILS(QUATECH_ESU2_100, 8)},
96 	{QT_DETAILS(0, 0)}	/* Terminating entry */
97 };
98 
99 static const struct usb_device_id id_table[] = {
100 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_SSU2_100)},
101 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_100)},
102 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_400)},
103 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_100)},
104 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_400)},
105 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_100)},
106 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_400)},
107 	{}			/* Terminating entry */
108 };
109 MODULE_DEVICE_TABLE(usb, id_table);
110 
111 struct qt2_serial_private {
112 	unsigned char current_port;  /* current port for incoming data */
113 
114 	struct urb	*read_urb;   /* shared among all ports */
115 	char		read_buffer[512];
116 };
117 
118 struct qt2_port_private {
119 	bool is_open;
120 	u8   device_port;
121 
122 	spinlock_t urb_lock;
123 	bool       urb_in_use;
124 	struct urb *write_urb;
125 	char       write_buffer[QT2_WRITE_BUFFER_SIZE];
126 
127 	spinlock_t  lock;
128 	u8          shadowLSR;
129 	u8          shadowMSR;
130 
131 	struct async_icount icount;
132 
133 	struct usb_serial_port *port;
134 };
135 
136 static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch);
137 static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch);
138 static void qt2_write_bulk_callback(struct urb *urb);
139 static void qt2_read_bulk_callback(struct urb *urb);
140 
141 static void qt2_release(struct usb_serial *serial)
142 {
143 	struct qt2_serial_private *serial_priv;
144 
145 	serial_priv = usb_get_serial_data(serial);
146 
147 	usb_free_urb(serial_priv->read_urb);
148 	kfree(serial_priv);
149 }
150 
151 static inline int calc_baud_divisor(int baudrate)
152 {
153 	int divisor, rem;
154 
155 	divisor = MAX_BAUD_RATE / baudrate;
156 	rem = MAX_BAUD_RATE % baudrate;
157 	/* Round to nearest divisor */
158 	if (((rem * 2) >= baudrate) && (baudrate != 110))
159 		divisor++;
160 
161 	return divisor;
162 }
163 
164 static inline int qt2_set_port_config(struct usb_device *dev,
165 				      unsigned char port_number,
166 				      u16 baudrate, u16 lcr)
167 {
168 	int divisor = calc_baud_divisor(baudrate);
169 	u16 index = ((u16) (lcr << 8) | (u16) (port_number));
170 
171 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
172 			       QT2_GET_SET_UART, 0x40,
173 			       divisor, index, NULL, 0, QT2_USB_TIMEOUT);
174 }
175 
176 static inline int qt2_control_msg(struct usb_device *dev,
177 				  u8 request, u16 data, u16 index)
178 {
179 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
180 			       request, 0x40, data, index,
181 			       NULL, 0, QT2_USB_TIMEOUT);
182 }
183 
184 static inline int qt2_setdevice(struct usb_device *dev, u8 *data)
185 {
186 	u16 x = ((u16) (data[1] << 8) | (u16) (data[0]));
187 
188 	return qt2_control_msg(dev, QT_SET_GET_DEVICE, x, 0);
189 }
190 
191 
192 static inline int qt2_getdevice(struct usb_device *dev, u8 *data)
193 {
194 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
195 			       QT_SET_GET_DEVICE, 0xc0, 0, 0,
196 			       data, 3, QT2_USB_TIMEOUT);
197 }
198 
199 static inline int qt2_getregister(struct usb_device *dev,
200 				  u8 uart,
201 				  u8 reg,
202 				  u8 *data)
203 {
204 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
205 			       QT_SET_GET_REGISTER, 0xc0, reg,
206 			       uart, data, sizeof(*data), QT2_USB_TIMEOUT);
207 
208 }
209 
210 static inline int qt2_setregister(struct usb_device *dev,
211 				  u8 uart, u8 reg, u16 data)
212 {
213 	u16 value = (data << 8) | reg;
214 
215 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
216 			       QT_SET_GET_REGISTER, 0x40, value, uart,
217 			       NULL, 0, QT2_USB_TIMEOUT);
218 }
219 
220 static inline int update_mctrl(struct qt2_port_private *port_priv,
221 			       unsigned int set, unsigned int clear)
222 {
223 	struct usb_serial_port *port = port_priv->port;
224 	struct usb_device *dev = port->serial->dev;
225 	unsigned urb_value;
226 	int status;
227 
228 	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0) {
229 		dev_dbg(&port->dev,
230 			"update_mctrl - DTR|RTS not being set|cleared\n");
231 		return 0;	/* no change */
232 	}
233 
234 	clear &= ~set;	/* 'set' takes precedence over 'clear' */
235 	urb_value = 0;
236 	if (set & TIOCM_DTR)
237 		urb_value |= UART_MCR_DTR;
238 	if (set & TIOCM_RTS)
239 		urb_value |= UART_MCR_RTS;
240 
241 	status = qt2_setregister(dev, port_priv->device_port, UART_MCR,
242 				 urb_value);
243 	if (status < 0)
244 		dev_err(&port->dev,
245 			"update_mctrl - Error from MODEM_CTRL urb: %i\n",
246 			status);
247 	return status;
248 }
249 
250 static int qt2_calc_num_ports(struct usb_serial *serial)
251 {
252 	struct qt2_device_detail d;
253 	int i;
254 
255 	for (i = 0; d = qt2_device_details[i], d.product_id != 0; i++) {
256 		if (d.product_id == le16_to_cpu(serial->dev->descriptor.idProduct))
257 			return d.num_ports;
258 	}
259 
260 	/* we didn't recognize the device */
261 	dev_err(&serial->dev->dev,
262 		 "don't know the number of ports, assuming 1\n");
263 
264 	return 1;
265 }
266 
267 static void qt2_set_termios(struct tty_struct *tty,
268 			    struct usb_serial_port *port,
269 			    struct ktermios *old_termios)
270 {
271 	struct usb_device *dev = port->serial->dev;
272 	struct qt2_port_private *port_priv;
273 	struct ktermios *termios = &tty->termios;
274 	u16 baud;
275 	unsigned int cflag = termios->c_cflag;
276 	u16 new_lcr = 0;
277 	int status;
278 
279 	port_priv = usb_get_serial_port_data(port);
280 
281 	if (cflag & PARENB) {
282 		if (cflag & PARODD)
283 			new_lcr |= UART_LCR_PARITY;
284 		else
285 			new_lcr |= SERIAL_EVEN_PARITY;
286 	}
287 
288 	switch (cflag & CSIZE) {
289 	case CS5:
290 		new_lcr |= UART_LCR_WLEN5;
291 		break;
292 	case CS6:
293 		new_lcr |= UART_LCR_WLEN6;
294 		break;
295 	case CS7:
296 		new_lcr |= UART_LCR_WLEN7;
297 		break;
298 	default:
299 	case CS8:
300 		new_lcr |= UART_LCR_WLEN8;
301 		break;
302 	}
303 
304 	baud = tty_get_baud_rate(tty);
305 	if (!baud)
306 		baud = 9600;
307 
308 	status = qt2_set_port_config(dev, port_priv->device_port, baud,
309 				     new_lcr);
310 	if (status < 0)
311 		dev_err(&port->dev, "%s - qt2_set_port_config failed: %i\n",
312 			__func__, status);
313 
314 	if (cflag & CRTSCTS)
315 		status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
316 					 SERIAL_CRTSCTS,
317 					 port_priv->device_port);
318 	else
319 		status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
320 					 0, port_priv->device_port);
321 	if (status < 0)
322 		dev_err(&port->dev, "%s - set HW flow control failed: %i\n",
323 			__func__, status);
324 
325 	if (I_IXOFF(tty) || I_IXON(tty)) {
326 		u16 x = ((u16) (START_CHAR(tty) << 8) | (u16) (STOP_CHAR(tty)));
327 
328 		status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
329 					 x, port_priv->device_port);
330 	} else
331 		status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
332 					 0, port_priv->device_port);
333 
334 	if (status < 0)
335 		dev_err(&port->dev, "%s - set SW flow control failed: %i\n",
336 			__func__, status);
337 
338 }
339 
340 static int qt2_open(struct tty_struct *tty, struct usb_serial_port *port)
341 {
342 	struct usb_serial *serial;
343 	struct qt2_port_private *port_priv;
344 	u8 *data;
345 	u16 device_port;
346 	int status;
347 	unsigned long flags;
348 
349 	device_port = (u16) (port->number - port->serial->minor);
350 
351 	serial = port->serial;
352 
353 	port_priv = usb_get_serial_port_data(port);
354 
355 	/* set the port to RS232 mode */
356 	status = qt2_control_msg(serial->dev, QT2_GET_SET_QMCR,
357 				 QT2_QMCR_RS232, device_port);
358 	if (status < 0) {
359 		dev_err(&port->dev,
360 			"%s failed to set RS232 mode for port %i error %i\n",
361 			__func__, device_port, status);
362 		return status;
363 	}
364 
365 	data = kzalloc(2, GFP_KERNEL);
366 	if (!data)
367 		return -ENOMEM;
368 
369 	/* open the port */
370 	status = usb_control_msg(serial->dev,
371 				 usb_rcvctrlpipe(serial->dev, 0),
372 				 QT_OPEN_CLOSE_CHANNEL,
373 				 0xc0, 0,
374 				 device_port, data, 2, QT2_USB_TIMEOUT);
375 
376 	if (status < 0) {
377 		dev_err(&port->dev, "%s - open port failed %i", __func__,
378 			status);
379 		kfree(data);
380 		return status;
381 	}
382 
383 	spin_lock_irqsave(&port_priv->lock, flags);
384 	port_priv->shadowLSR = data[0];
385 	port_priv->shadowMSR = data[1];
386 	spin_unlock_irqrestore(&port_priv->lock, flags);
387 
388 	kfree(data);
389 
390 	/* set to default speed and 8bit word size */
391 	status = qt2_set_port_config(serial->dev, device_port,
392 				     DEFAULT_BAUD_RATE, UART_LCR_WLEN8);
393 	if (status < 0) {
394 		dev_err(&port->dev,
395 			"%s - initial setup failed for port %i (%i)\n",
396 			__func__, port->number, device_port);
397 		return status;
398 	}
399 
400 	port_priv->is_open = true;
401 	port_priv->device_port = (u8) device_port;
402 
403 	if (tty)
404 		qt2_set_termios(tty, port, &tty->termios);
405 
406 	return 0;
407 
408 }
409 
410 static void qt2_close(struct usb_serial_port *port)
411 {
412 	struct usb_serial *serial;
413 	struct qt2_port_private *port_priv;
414 	unsigned long flags;
415 	int i;
416 
417 	serial = port->serial;
418 	port_priv = usb_get_serial_port_data(port);
419 
420 	port_priv->is_open = false;
421 
422 	spin_lock_irqsave(&port_priv->urb_lock, flags);
423 	usb_kill_urb(port_priv->write_urb);
424 	port_priv->urb_in_use = false;
425 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
426 
427 	mutex_lock(&port->serial->disc_mutex);
428 	if (port->serial->disconnected) {
429 		mutex_unlock(&port->serial->disc_mutex);
430 		return;
431 	}
432 
433 	/* flush the port transmit buffer */
434 	i = usb_control_msg(serial->dev,
435 			    usb_rcvctrlpipe(serial->dev, 0),
436 			    QT2_FLUSH_DEVICE, 0x40, 1,
437 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
438 
439 	if (i < 0)
440 		dev_err(&port->dev, "%s - transmit buffer flush failed: %i\n",
441 			__func__, i);
442 
443 	/* flush the port receive buffer */
444 	i = usb_control_msg(serial->dev,
445 			    usb_rcvctrlpipe(serial->dev, 0),
446 			    QT2_FLUSH_DEVICE, 0x40, 0,
447 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
448 
449 	if (i < 0)
450 		dev_err(&port->dev, "%s - receive buffer flush failed: %i\n",
451 			__func__, i);
452 
453 	/* close the port */
454 	i = usb_control_msg(serial->dev,
455 			    usb_sndctrlpipe(serial->dev, 0),
456 			    QT_OPEN_CLOSE_CHANNEL,
457 			    0x40, 0,
458 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
459 
460 	if (i < 0)
461 		dev_err(&port->dev, "%s - close port failed %i\n",
462 			__func__, i);
463 
464 	mutex_unlock(&port->serial->disc_mutex);
465 }
466 
467 static void qt2_disconnect(struct usb_serial *serial)
468 {
469 	struct qt2_serial_private *serial_priv = usb_get_serial_data(serial);
470 
471 	usb_kill_urb(serial_priv->read_urb);
472 }
473 
474 static int get_serial_info(struct usb_serial_port *port,
475 			   struct serial_struct __user *retinfo)
476 {
477 	struct serial_struct tmp;
478 
479 	if (!retinfo)
480 		return -EFAULT;
481 
482 	memset(&tmp, 0, sizeof(tmp));
483 	tmp.line		= port->serial->minor;
484 	tmp.port		= 0;
485 	tmp.irq			= 0;
486 	tmp.flags		= ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
487 	tmp.xmit_fifo_size	= port->bulk_out_size;
488 	tmp.baud_base		= 9600;
489 	tmp.close_delay		= 5*HZ;
490 	tmp.closing_wait	= 30*HZ;
491 
492 	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
493 		return -EFAULT;
494 	return 0;
495 }
496 
497 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
498 {
499 	struct qt2_port_private *priv = usb_get_serial_port_data(port);
500 	struct async_icount prev, cur;
501 	unsigned long flags;
502 
503 	spin_lock_irqsave(&priv->lock, flags);
504 	prev = priv->icount;
505 	spin_unlock_irqrestore(&priv->lock, flags);
506 
507 	while (1) {
508 		wait_event_interruptible(port->delta_msr_wait,
509 					 (port->serial->disconnected ||
510 					  (priv->icount.rng != prev.rng) ||
511 					  (priv->icount.dsr != prev.dsr) ||
512 					  (priv->icount.dcd != prev.dcd) ||
513 					  (priv->icount.cts != prev.cts)));
514 
515 		if (signal_pending(current))
516 			return -ERESTARTSYS;
517 
518 		if (port->serial->disconnected)
519 			return -EIO;
520 
521 		spin_lock_irqsave(&priv->lock, flags);
522 		cur = priv->icount;
523 		spin_unlock_irqrestore(&priv->lock, flags);
524 
525 		if ((prev.rng == cur.rng) &&
526 		    (prev.dsr == cur.dsr) &&
527 		    (prev.dcd == cur.dcd) &&
528 		    (prev.cts == cur.cts))
529 			return -EIO;
530 
531 		if ((arg & TIOCM_RNG && (prev.rng != cur.rng)) ||
532 		    (arg & TIOCM_DSR && (prev.dsr != cur.dsr)) ||
533 		    (arg & TIOCM_CD && (prev.dcd != cur.dcd)) ||
534 		    (arg & TIOCM_CTS && (prev.cts != cur.cts)))
535 			return 0;
536 	}
537 	return 0;
538 }
539 
540 static int qt2_get_icount(struct tty_struct *tty,
541 			  struct serial_icounter_struct *icount)
542 {
543 	struct usb_serial_port *port = tty->driver_data;
544 	struct qt2_port_private *priv = usb_get_serial_port_data(port);
545 	struct async_icount cnow = priv->icount;
546 
547 	icount->cts = cnow.cts;
548 	icount->dsr = cnow.dsr;
549 	icount->rng = cnow.rng;
550 	icount->dcd = cnow.dcd;
551 	icount->rx = cnow.rx;
552 	icount->tx = cnow.tx;
553 	icount->frame = cnow.frame;
554 	icount->overrun = cnow.overrun;
555 	icount->parity = cnow.parity;
556 	icount->brk = cnow.brk;
557 	icount->buf_overrun = cnow.buf_overrun;
558 
559 	return 0;
560 }
561 
562 static int qt2_ioctl(struct tty_struct *tty,
563 		     unsigned int cmd, unsigned long arg)
564 {
565 	struct usb_serial_port *port = tty->driver_data;
566 
567 	switch (cmd) {
568 	case TIOCGSERIAL:
569 		return get_serial_info(port,
570 				       (struct serial_struct __user *)arg);
571 
572 	case TIOCMIWAIT:
573 		return wait_modem_info(port, arg);
574 
575 	default:
576 		break;
577 	}
578 
579 	return -ENOIOCTLCMD;
580 }
581 
582 static void qt2_process_status(struct usb_serial_port *port, unsigned char *ch)
583 {
584 	switch (*ch) {
585 	case QT2_LINE_STATUS:
586 		qt2_update_lsr(port, ch + 1);
587 		break;
588 	case QT2_MODEM_STATUS:
589 		qt2_update_msr(port, ch + 1);
590 		break;
591 	}
592 }
593 
594 /* not needed, kept to document functionality */
595 static void qt2_process_xmit_empty(struct usb_serial_port *port,
596 				   unsigned char *ch)
597 {
598 	int bytes_written;
599 
600 	bytes_written = (int)(*ch) + (int)(*(ch + 1) << 4);
601 }
602 
603 /* not needed, kept to document functionality */
604 static void qt2_process_flush(struct usb_serial_port *port, unsigned char *ch)
605 {
606 	return;
607 }
608 
609 void qt2_process_read_urb(struct urb *urb)
610 {
611 	struct usb_serial *serial;
612 	struct qt2_serial_private *serial_priv;
613 	struct usb_serial_port *port;
614 	struct qt2_port_private *port_priv;
615 	bool escapeflag;
616 	unsigned char *ch;
617 	int i;
618 	unsigned char newport;
619 	int len = urb->actual_length;
620 
621 	if (!len)
622 		return;
623 
624 	ch = urb->transfer_buffer;
625 	serial = urb->context;
626 	serial_priv = usb_get_serial_data(serial);
627 	port = serial->port[serial_priv->current_port];
628 	port_priv = usb_get_serial_port_data(port);
629 
630 	for (i = 0; i < urb->actual_length; i++) {
631 		ch = (unsigned char *)urb->transfer_buffer + i;
632 		if ((i <= (len - 3)) &&
633 		    (*ch == QT2_CONTROL_BYTE) &&
634 		    (*(ch + 1) == QT2_CONTROL_BYTE)) {
635 			escapeflag = false;
636 			switch (*(ch + 2)) {
637 			case QT2_LINE_STATUS:
638 			case QT2_MODEM_STATUS:
639 				if (i > (len - 4)) {
640 					dev_warn(&port->dev,
641 						 "%s - status message too short\n",
642 						__func__);
643 					break;
644 				}
645 				qt2_process_status(port, ch + 2);
646 				i += 3;
647 				escapeflag = true;
648 				break;
649 			case QT2_XMIT_HOLD:
650 				if (i > (len - 5)) {
651 					dev_warn(&port->dev,
652 						 "%s - xmit_empty message too short\n",
653 						 __func__);
654 					break;
655 				}
656 				qt2_process_xmit_empty(port, ch + 3);
657 				i += 4;
658 				escapeflag = true;
659 				break;
660 			case QT2_CHANGE_PORT:
661 				if (i > (len - 4)) {
662 					dev_warn(&port->dev,
663 						 "%s - change_port message too short\n",
664 						 __func__);
665 					break;
666 				}
667 
668 				if (port_priv->is_open)
669 					tty_flip_buffer_push(&port->port);
670 
671 				newport = *(ch + 3);
672 
673 				if (newport > serial->num_ports) {
674 					dev_err(&port->dev,
675 						"%s - port change to invalid port: %i\n",
676 						__func__, newport);
677 					break;
678 				}
679 
680 				serial_priv->current_port = newport;
681 				port = serial->port[serial_priv->current_port];
682 				port_priv = usb_get_serial_port_data(port);
683 				i += 3;
684 				escapeflag = true;
685 				break;
686 			case QT2_REC_FLUSH:
687 			case QT2_XMIT_FLUSH:
688 				qt2_process_flush(port, ch + 2);
689 				i += 2;
690 				escapeflag = true;
691 				break;
692 			case QT2_CONTROL_ESCAPE:
693 				tty_buffer_request_room(&port->port, 2);
694 				tty_insert_flip_string(&port->port, ch, 2);
695 				i += 2;
696 				escapeflag = true;
697 				break;
698 			default:
699 				dev_warn(&port->dev,
700 					 "%s - unsupported command %i\n",
701 					 __func__, *(ch + 2));
702 				break;
703 			}
704 			if (escapeflag)
705 				continue;
706 		}
707 
708 		tty_buffer_request_room(&port->port, 1);
709 		tty_insert_flip_string(&port->port, ch, 1);
710 	}
711 
712 	if (port_priv->is_open)
713 		tty_flip_buffer_push(&port->port);
714 }
715 
716 static void qt2_write_bulk_callback(struct urb *urb)
717 {
718 	struct usb_serial_port *port;
719 	struct qt2_port_private *port_priv;
720 
721 	port = urb->context;
722 	port_priv = usb_get_serial_port_data(port);
723 
724 	spin_lock(&port_priv->urb_lock);
725 
726 	port_priv->urb_in_use = false;
727 	usb_serial_port_softint(port);
728 
729 	spin_unlock(&port_priv->urb_lock);
730 
731 }
732 
733 static void qt2_read_bulk_callback(struct urb *urb)
734 {
735 	struct usb_serial *serial = urb->context;
736 	int status;
737 
738 	if (urb->status) {
739 		dev_warn(&serial->dev->dev,
740 			 "%s - non-zero urb status: %i\n", __func__,
741 			 urb->status);
742 		return;
743 	}
744 
745 	qt2_process_read_urb(urb);
746 
747 	status = usb_submit_urb(urb, GFP_ATOMIC);
748 	if (status != 0)
749 		dev_err(&serial->dev->dev,
750 			"%s - resubmit read urb failed: %i\n",
751 			__func__, status);
752 }
753 
754 static int qt2_setup_urbs(struct usb_serial *serial)
755 {
756 	struct usb_serial_port *port0;
757 	struct qt2_serial_private *serial_priv;
758 	int status;
759 
760 	port0 = serial->port[0];
761 
762 	serial_priv = usb_get_serial_data(serial);
763 	serial_priv->read_urb = usb_alloc_urb(0, GFP_KERNEL);
764 	if (!serial_priv->read_urb) {
765 		dev_err(&serial->dev->dev, "No free urbs available\n");
766 		return -ENOMEM;
767 	}
768 
769 	usb_fill_bulk_urb(serial_priv->read_urb, serial->dev,
770 			  usb_rcvbulkpipe(serial->dev,
771 					  port0->bulk_in_endpointAddress),
772 			  serial_priv->read_buffer,
773 			  sizeof(serial_priv->read_buffer),
774 			  qt2_read_bulk_callback, serial);
775 
776 	status = usb_submit_urb(serial_priv->read_urb, GFP_KERNEL);
777 	if (status != 0) {
778 		dev_err(&serial->dev->dev,
779 			"%s - submit read urb failed %i\n", __func__, status);
780 		usb_free_urb(serial_priv->read_urb);
781 		return status;
782 	}
783 
784 	return 0;
785 }
786 
787 static int qt2_attach(struct usb_serial *serial)
788 {
789 	struct qt2_serial_private *serial_priv;
790 	int status;
791 
792 	/* power on unit */
793 	status = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
794 				 0xc2, 0x40, 0x8000, 0, NULL, 0,
795 				 QT2_USB_TIMEOUT);
796 	if (status < 0) {
797 		dev_err(&serial->dev->dev,
798 			"%s - failed to power on unit: %i\n", __func__, status);
799 		return status;
800 	}
801 
802 	serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL);
803 	if (!serial_priv) {
804 		dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
805 		return -ENOMEM;
806 	}
807 
808 	usb_set_serial_data(serial, serial_priv);
809 
810 	status = qt2_setup_urbs(serial);
811 	if (status != 0)
812 		goto attach_failed;
813 
814 	return 0;
815 
816 attach_failed:
817 	kfree(serial_priv);
818 	return status;
819 }
820 
821 static int qt2_port_probe(struct usb_serial_port *port)
822 {
823 	struct usb_serial *serial = port->serial;
824 	struct qt2_port_private *port_priv;
825 	u8 bEndpointAddress;
826 
827 	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
828 	if (!port_priv)
829 		return -ENOMEM;
830 
831 	spin_lock_init(&port_priv->lock);
832 	spin_lock_init(&port_priv->urb_lock);
833 	port_priv->port = port;
834 
835 	port_priv->write_urb = usb_alloc_urb(0, GFP_KERNEL);
836 	if (!port_priv->write_urb) {
837 		kfree(port_priv);
838 		return -ENOMEM;
839 	}
840 	bEndpointAddress = serial->port[0]->bulk_out_endpointAddress;
841 	usb_fill_bulk_urb(port_priv->write_urb, serial->dev,
842 				usb_sndbulkpipe(serial->dev, bEndpointAddress),
843 				port_priv->write_buffer,
844 				sizeof(port_priv->write_buffer),
845 				qt2_write_bulk_callback, port);
846 
847 	usb_set_serial_port_data(port, port_priv);
848 
849 	return 0;
850 }
851 
852 static int qt2_port_remove(struct usb_serial_port *port)
853 {
854 	struct qt2_port_private *port_priv;
855 
856 	port_priv = usb_get_serial_port_data(port);
857 	usb_free_urb(port_priv->write_urb);
858 	kfree(port_priv);
859 
860 	return 0;
861 }
862 
863 static int qt2_tiocmget(struct tty_struct *tty)
864 {
865 	struct usb_serial_port *port = tty->driver_data;
866 	struct usb_device *dev = port->serial->dev;
867 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
868 	u8 *d;
869 	int r;
870 
871 	d = kzalloc(2, GFP_KERNEL);
872 	if (!d)
873 		return -ENOMEM;
874 
875 	r = qt2_getregister(dev, port_priv->device_port, UART_MCR, d);
876 	if (r < 0)
877 		goto mget_out;
878 
879 	r = qt2_getregister(dev, port_priv->device_port, UART_MSR, d + 1);
880 	if (r < 0)
881 		goto mget_out;
882 
883 	r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) |
884 	    (d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) |
885 	    (d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) |
886 	    (d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) |
887 	    (d[1] & UART_MSR_RI ? TIOCM_RI : 0) |
888 	    (d[1] & UART_MSR_DSR ? TIOCM_DSR : 0);
889 
890 mget_out:
891 	kfree(d);
892 	return r;
893 }
894 
895 static int qt2_tiocmset(struct tty_struct *tty,
896 			unsigned int set, unsigned int clear)
897 {
898 	struct qt2_port_private *port_priv;
899 
900 	port_priv = usb_get_serial_port_data(tty->driver_data);
901 	return update_mctrl(port_priv, set, clear);
902 }
903 
904 static void qt2_break_ctl(struct tty_struct *tty, int break_state)
905 {
906 	struct usb_serial_port *port = tty->driver_data;
907 	struct qt2_port_private *port_priv;
908 	int status;
909 	u16 val;
910 
911 	port_priv = usb_get_serial_port_data(port);
912 
913 	if (!port_priv->is_open) {
914 		dev_err(&port->dev,
915 			"%s - port is not open\n", __func__);
916 		return;
917 	}
918 
919 	val = (break_state == -1) ? 1 : 0;
920 
921 	status = qt2_control_msg(port->serial->dev, QT2_BREAK_CONTROL,
922 				 val, port_priv->device_port);
923 	if (status < 0)
924 		dev_warn(&port->dev,
925 			 "%s - failed to send control message: %i\n", __func__,
926 			 status);
927 }
928 
929 
930 
931 static void qt2_dtr_rts(struct usb_serial_port *port, int on)
932 {
933 	struct usb_device *dev = port->serial->dev;
934 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
935 
936 	/* Disable flow control */
937 	if (!on) {
938 		if (qt2_setregister(dev, port_priv->device_port,
939 					   UART_MCR, 0) < 0)
940 			dev_warn(&port->dev, "error from flowcontrol urb\n");
941 	}
942 	/* drop RTS and DTR */
943 	if (on)
944 		update_mctrl(port_priv, TIOCM_DTR | TIOCM_RTS, 0);
945 	else
946 		update_mctrl(port_priv, 0, TIOCM_DTR | TIOCM_RTS);
947 }
948 
949 static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch)
950 {
951 	struct qt2_port_private *port_priv;
952 	u8 newMSR = (u8) *ch;
953 	unsigned long flags;
954 
955 	port_priv = usb_get_serial_port_data(port);
956 
957 	spin_lock_irqsave(&port_priv->lock, flags);
958 	port_priv->shadowMSR = newMSR;
959 	spin_unlock_irqrestore(&port_priv->lock, flags);
960 
961 	if (newMSR & UART_MSR_ANY_DELTA) {
962 		/* update input line counters */
963 		if (newMSR & UART_MSR_DCTS)
964 			port_priv->icount.cts++;
965 
966 		if (newMSR & UART_MSR_DDSR)
967 			port_priv->icount.dsr++;
968 
969 		if (newMSR & UART_MSR_DDCD)
970 			port_priv->icount.dcd++;
971 
972 		if (newMSR & UART_MSR_TERI)
973 			port_priv->icount.rng++;
974 
975 		wake_up_interruptible(&port->delta_msr_wait);
976 	}
977 }
978 
979 static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch)
980 {
981 	struct qt2_port_private *port_priv;
982 	struct async_icount *icount;
983 	unsigned long flags;
984 	u8 newLSR = (u8) *ch;
985 
986 	port_priv = usb_get_serial_port_data(port);
987 
988 	if (newLSR & UART_LSR_BI)
989 		newLSR &= (u8) (UART_LSR_OE | UART_LSR_BI);
990 
991 	spin_lock_irqsave(&port_priv->lock, flags);
992 	port_priv->shadowLSR = newLSR;
993 	spin_unlock_irqrestore(&port_priv->lock, flags);
994 
995 	icount = &port_priv->icount;
996 
997 	if (newLSR & UART_LSR_BRK_ERROR_BITS) {
998 
999 		if (newLSR & UART_LSR_BI)
1000 			icount->brk++;
1001 
1002 		if (newLSR & UART_LSR_OE)
1003 			icount->overrun++;
1004 
1005 		if (newLSR & UART_LSR_PE)
1006 			icount->parity++;
1007 
1008 		if (newLSR & UART_LSR_FE)
1009 			icount->frame++;
1010 	}
1011 
1012 }
1013 
1014 static int qt2_write_room(struct tty_struct *tty)
1015 {
1016 	struct usb_serial_port *port = tty->driver_data;
1017 	struct qt2_port_private *port_priv;
1018 	unsigned long flags = 0;
1019 	int r;
1020 
1021 	port_priv = usb_get_serial_port_data(port);
1022 
1023 	spin_lock_irqsave(&port_priv->urb_lock, flags);
1024 
1025 	if (port_priv->urb_in_use)
1026 		r = 0;
1027 	else
1028 		r = QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE;
1029 
1030 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
1031 
1032 	return r;
1033 }
1034 
1035 static int qt2_write(struct tty_struct *tty,
1036 		     struct usb_serial_port *port,
1037 		     const unsigned char *buf, int count)
1038 {
1039 	struct qt2_port_private *port_priv;
1040 	struct urb *write_urb;
1041 	unsigned char *data;
1042 	unsigned long flags;
1043 	int status;
1044 	int bytes_out = 0;
1045 
1046 	port_priv = usb_get_serial_port_data(port);
1047 
1048 	if (port_priv->write_urb == NULL) {
1049 		dev_err(&port->dev, "%s - no output urb\n", __func__);
1050 		return 0;
1051 	}
1052 	write_urb = port_priv->write_urb;
1053 
1054 	count = min(count, QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE);
1055 
1056 	data = write_urb->transfer_buffer;
1057 	spin_lock_irqsave(&port_priv->urb_lock, flags);
1058 	if (port_priv->urb_in_use == true) {
1059 		dev_err(&port->dev, "qt2_write - urb is in use\n");
1060 		goto write_out;
1061 	}
1062 
1063 	*data++ = QT2_CONTROL_BYTE;
1064 	*data++ = QT2_CONTROL_BYTE;
1065 	*data++ = port_priv->device_port;
1066 	put_unaligned_le16(count, data);
1067 	data += 2;
1068 	memcpy(data, buf, count);
1069 
1070 	write_urb->transfer_buffer_length = count + QT2_WRITE_CONTROL_SIZE;
1071 
1072 	status = usb_submit_urb(write_urb, GFP_ATOMIC);
1073 	if (status == 0) {
1074 		port_priv->urb_in_use = true;
1075 		bytes_out += count;
1076 	}
1077 
1078 write_out:
1079 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
1080 	return bytes_out;
1081 }
1082 
1083 
1084 static struct usb_serial_driver qt2_device = {
1085 	.driver = {
1086 		.owner = THIS_MODULE,
1087 		.name = "quatech-serial",
1088 	},
1089 	.description	     = DRIVER_DESC,
1090 	.id_table	     = id_table,
1091 	.open		     = qt2_open,
1092 	.close		     = qt2_close,
1093 	.write               = qt2_write,
1094 	.write_room          = qt2_write_room,
1095 	.calc_num_ports      = qt2_calc_num_ports,
1096 	.attach              = qt2_attach,
1097 	.release             = qt2_release,
1098 	.disconnect          = qt2_disconnect,
1099 	.port_probe          = qt2_port_probe,
1100 	.port_remove         = qt2_port_remove,
1101 	.dtr_rts             = qt2_dtr_rts,
1102 	.break_ctl           = qt2_break_ctl,
1103 	.tiocmget            = qt2_tiocmget,
1104 	.tiocmset            = qt2_tiocmset,
1105 	.get_icount	     = qt2_get_icount,
1106 	.ioctl               = qt2_ioctl,
1107 	.set_termios         = qt2_set_termios,
1108 };
1109 
1110 static struct usb_serial_driver *const serial_drivers[] = {
1111 	&qt2_device, NULL
1112 };
1113 
1114 module_usb_serial_driver(serial_drivers, id_table);
1115 
1116 MODULE_DESCRIPTION(DRIVER_DESC);
1117 MODULE_LICENSE("GPL");
1118