xref: /openbmc/linux/drivers/usb/serial/quatech2.c (revision 97da55fc)
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 	wait_queue_head_t   delta_msr_wait; /* Used for TIOCMIWAIT */
132 	struct async_icount icount;
133 
134 	struct usb_serial_port *port;
135 };
136 
137 static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch);
138 static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch);
139 static void qt2_write_bulk_callback(struct urb *urb);
140 static void qt2_read_bulk_callback(struct urb *urb);
141 
142 static void qt2_release(struct usb_serial *serial)
143 {
144 	struct qt2_serial_private *serial_priv;
145 
146 	serial_priv = usb_get_serial_data(serial);
147 
148 	usb_free_urb(serial_priv->read_urb);
149 	kfree(serial_priv);
150 }
151 
152 static inline int calc_baud_divisor(int baudrate)
153 {
154 	int divisor, rem;
155 
156 	divisor = MAX_BAUD_RATE / baudrate;
157 	rem = MAX_BAUD_RATE % baudrate;
158 	/* Round to nearest divisor */
159 	if (((rem * 2) >= baudrate) && (baudrate != 110))
160 		divisor++;
161 
162 	return divisor;
163 }
164 
165 static inline int qt2_set_port_config(struct usb_device *dev,
166 				      unsigned char port_number,
167 				      u16 baudrate, u16 lcr)
168 {
169 	int divisor = calc_baud_divisor(baudrate);
170 	u16 index = ((u16) (lcr << 8) | (u16) (port_number));
171 
172 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
173 			       QT2_GET_SET_UART, 0x40,
174 			       divisor, index, NULL, 0, QT2_USB_TIMEOUT);
175 }
176 
177 static inline int qt2_control_msg(struct usb_device *dev,
178 				  u8 request, u16 data, u16 index)
179 {
180 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
181 			       request, 0x40, data, index,
182 			       NULL, 0, QT2_USB_TIMEOUT);
183 }
184 
185 static inline int qt2_setdevice(struct usb_device *dev, u8 *data)
186 {
187 	u16 x = ((u16) (data[1] << 8) | (u16) (data[0]));
188 
189 	return qt2_control_msg(dev, QT_SET_GET_DEVICE, x, 0);
190 }
191 
192 
193 static inline int qt2_getdevice(struct usb_device *dev, u8 *data)
194 {
195 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
196 			       QT_SET_GET_DEVICE, 0xc0, 0, 0,
197 			       data, 3, QT2_USB_TIMEOUT);
198 }
199 
200 static inline int qt2_getregister(struct usb_device *dev,
201 				  u8 uart,
202 				  u8 reg,
203 				  u8 *data)
204 {
205 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
206 			       QT_SET_GET_REGISTER, 0xc0, reg,
207 			       uart, data, sizeof(*data), QT2_USB_TIMEOUT);
208 
209 }
210 
211 static inline int qt2_setregister(struct usb_device *dev,
212 				  u8 uart, u8 reg, u16 data)
213 {
214 	u16 value = (data << 8) | reg;
215 
216 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
217 			       QT_SET_GET_REGISTER, 0x40, value, uart,
218 			       NULL, 0, QT2_USB_TIMEOUT);
219 }
220 
221 static inline int update_mctrl(struct qt2_port_private *port_priv,
222 			       unsigned int set, unsigned int clear)
223 {
224 	struct usb_serial_port *port = port_priv->port;
225 	struct usb_device *dev = port->serial->dev;
226 	unsigned urb_value;
227 	int status;
228 
229 	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0) {
230 		dev_dbg(&port->dev,
231 			"update_mctrl - DTR|RTS not being set|cleared\n");
232 		return 0;	/* no change */
233 	}
234 
235 	clear &= ~set;	/* 'set' takes precedence over 'clear' */
236 	urb_value = 0;
237 	if (set & TIOCM_DTR)
238 		urb_value |= UART_MCR_DTR;
239 	if (set & TIOCM_RTS)
240 		urb_value |= UART_MCR_RTS;
241 
242 	status = qt2_setregister(dev, port_priv->device_port, UART_MCR,
243 				 urb_value);
244 	if (status < 0)
245 		dev_err(&port->dev,
246 			"update_mctrl - Error from MODEM_CTRL urb: %i\n",
247 			status);
248 	return status;
249 }
250 
251 static int qt2_calc_num_ports(struct usb_serial *serial)
252 {
253 	struct qt2_device_detail d;
254 	int i;
255 
256 	for (i = 0; d = qt2_device_details[i], d.product_id != 0; i++) {
257 		if (d.product_id == le16_to_cpu(serial->dev->descriptor.idProduct))
258 			return d.num_ports;
259 	}
260 
261 	/* we didn't recognize the device */
262 	dev_err(&serial->dev->dev,
263 		 "don't know the number of ports, assuming 1\n");
264 
265 	return 1;
266 }
267 
268 static void qt2_set_termios(struct tty_struct *tty,
269 			    struct usb_serial_port *port,
270 			    struct ktermios *old_termios)
271 {
272 	struct usb_device *dev = port->serial->dev;
273 	struct qt2_port_private *port_priv;
274 	struct ktermios *termios = &tty->termios;
275 	u16 baud;
276 	unsigned int cflag = termios->c_cflag;
277 	u16 new_lcr = 0;
278 	int status;
279 
280 	port_priv = usb_get_serial_port_data(port);
281 
282 	if (cflag & PARENB) {
283 		if (cflag & PARODD)
284 			new_lcr |= UART_LCR_PARITY;
285 		else
286 			new_lcr |= SERIAL_EVEN_PARITY;
287 	}
288 
289 	switch (cflag & CSIZE) {
290 	case CS5:
291 		new_lcr |= UART_LCR_WLEN5;
292 		break;
293 	case CS6:
294 		new_lcr |= UART_LCR_WLEN6;
295 		break;
296 	case CS7:
297 		new_lcr |= UART_LCR_WLEN7;
298 		break;
299 	default:
300 	case CS8:
301 		new_lcr |= UART_LCR_WLEN8;
302 		break;
303 	}
304 
305 	baud = tty_get_baud_rate(tty);
306 	if (!baud)
307 		baud = 9600;
308 
309 	status = qt2_set_port_config(dev, port_priv->device_port, baud,
310 				     new_lcr);
311 	if (status < 0)
312 		dev_err(&port->dev, "%s - qt2_set_port_config failed: %i\n",
313 			__func__, status);
314 
315 	if (cflag & CRTSCTS)
316 		status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
317 					 SERIAL_CRTSCTS,
318 					 port_priv->device_port);
319 	else
320 		status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
321 					 0, port_priv->device_port);
322 	if (status < 0)
323 		dev_err(&port->dev, "%s - set HW flow control failed: %i\n",
324 			__func__, status);
325 
326 	if (I_IXOFF(tty) || I_IXON(tty)) {
327 		u16 x = ((u16) (START_CHAR(tty) << 8) | (u16) (STOP_CHAR(tty)));
328 
329 		status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
330 					 x, port_priv->device_port);
331 	} else
332 		status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
333 					 0, port_priv->device_port);
334 
335 	if (status < 0)
336 		dev_err(&port->dev, "%s - set SW flow control failed: %i\n",
337 			__func__, status);
338 
339 }
340 
341 static int qt2_open(struct tty_struct *tty, struct usb_serial_port *port)
342 {
343 	struct usb_serial *serial;
344 	struct qt2_port_private *port_priv;
345 	u8 *data;
346 	u16 device_port;
347 	int status;
348 	unsigned long flags;
349 
350 	device_port = (u16) (port->number - port->serial->minor);
351 
352 	serial = port->serial;
353 
354 	port_priv = usb_get_serial_port_data(port);
355 
356 	/* set the port to RS232 mode */
357 	status = qt2_control_msg(serial->dev, QT2_GET_SET_QMCR,
358 				 QT2_QMCR_RS232, device_port);
359 	if (status < 0) {
360 		dev_err(&port->dev,
361 			"%s failed to set RS232 mode for port %i error %i\n",
362 			__func__, device_port, status);
363 		return status;
364 	}
365 
366 	data = kzalloc(2, GFP_KERNEL);
367 	if (!data)
368 		return -ENOMEM;
369 
370 	/* open the port */
371 	status = usb_control_msg(serial->dev,
372 				 usb_rcvctrlpipe(serial->dev, 0),
373 				 QT_OPEN_CLOSE_CHANNEL,
374 				 0xc0, 0,
375 				 device_port, data, 2, QT2_USB_TIMEOUT);
376 
377 	if (status < 0) {
378 		dev_err(&port->dev, "%s - open port failed %i", __func__,
379 			status);
380 		kfree(data);
381 		return status;
382 	}
383 
384 	spin_lock_irqsave(&port_priv->lock, flags);
385 	port_priv->shadowLSR = data[0];
386 	port_priv->shadowMSR = data[1];
387 	spin_unlock_irqrestore(&port_priv->lock, flags);
388 
389 	kfree(data);
390 
391 	/* set to default speed and 8bit word size */
392 	status = qt2_set_port_config(serial->dev, device_port,
393 				     DEFAULT_BAUD_RATE, UART_LCR_WLEN8);
394 	if (status < 0) {
395 		dev_err(&port->dev,
396 			"%s - initial setup failed for port %i (%i)\n",
397 			__func__, port->number, device_port);
398 		return status;
399 	}
400 
401 	port_priv->is_open = true;
402 	port_priv->device_port = (u8) device_port;
403 
404 	if (tty)
405 		qt2_set_termios(tty, port, &tty->termios);
406 
407 	return 0;
408 
409 }
410 
411 static void qt2_close(struct usb_serial_port *port)
412 {
413 	struct usb_serial *serial;
414 	struct qt2_port_private *port_priv;
415 	unsigned long flags;
416 	int i;
417 
418 	serial = port->serial;
419 	port_priv = usb_get_serial_port_data(port);
420 
421 	port_priv->is_open = false;
422 
423 	spin_lock_irqsave(&port_priv->urb_lock, flags);
424 	usb_kill_urb(port_priv->write_urb);
425 	port_priv->urb_in_use = false;
426 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
427 
428 	mutex_lock(&port->serial->disc_mutex);
429 	if (port->serial->disconnected) {
430 		mutex_unlock(&port->serial->disc_mutex);
431 		return;
432 	}
433 
434 	/* flush the port transmit buffer */
435 	i = usb_control_msg(serial->dev,
436 			    usb_rcvctrlpipe(serial->dev, 0),
437 			    QT2_FLUSH_DEVICE, 0x40, 1,
438 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
439 
440 	if (i < 0)
441 		dev_err(&port->dev, "%s - transmit buffer flush failed: %i\n",
442 			__func__, i);
443 
444 	/* flush the port receive buffer */
445 	i = usb_control_msg(serial->dev,
446 			    usb_rcvctrlpipe(serial->dev, 0),
447 			    QT2_FLUSH_DEVICE, 0x40, 0,
448 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
449 
450 	if (i < 0)
451 		dev_err(&port->dev, "%s - receive buffer flush failed: %i\n",
452 			__func__, i);
453 
454 	/* close the port */
455 	i = usb_control_msg(serial->dev,
456 			    usb_sndctrlpipe(serial->dev, 0),
457 			    QT_OPEN_CLOSE_CHANNEL,
458 			    0x40, 0,
459 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
460 
461 	if (i < 0)
462 		dev_err(&port->dev, "%s - close port failed %i\n",
463 			__func__, i);
464 
465 	mutex_unlock(&port->serial->disc_mutex);
466 }
467 
468 static void qt2_disconnect(struct usb_serial *serial)
469 {
470 	struct qt2_serial_private *serial_priv = usb_get_serial_data(serial);
471 
472 	usb_kill_urb(serial_priv->read_urb);
473 }
474 
475 static int get_serial_info(struct usb_serial_port *port,
476 			   struct serial_struct __user *retinfo)
477 {
478 	struct serial_struct tmp;
479 
480 	if (!retinfo)
481 		return -EFAULT;
482 
483 	memset(&tmp, 0, sizeof(tmp));
484 	tmp.line		= port->serial->minor;
485 	tmp.port		= 0;
486 	tmp.irq			= 0;
487 	tmp.flags		= ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
488 	tmp.xmit_fifo_size	= port->bulk_out_size;
489 	tmp.baud_base		= 9600;
490 	tmp.close_delay		= 5*HZ;
491 	tmp.closing_wait	= 30*HZ;
492 
493 	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
494 		return -EFAULT;
495 	return 0;
496 }
497 
498 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
499 {
500 	struct qt2_port_private *priv = usb_get_serial_port_data(port);
501 	struct async_icount prev, cur;
502 	unsigned long flags;
503 
504 	spin_lock_irqsave(&priv->lock, flags);
505 	prev = priv->icount;
506 	spin_unlock_irqrestore(&priv->lock, flags);
507 
508 	while (1) {
509 		wait_event_interruptible(priv->delta_msr_wait,
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 		spin_lock_irqsave(&priv->lock, flags);
519 		cur = priv->icount;
520 		spin_unlock_irqrestore(&priv->lock, flags);
521 
522 		if ((prev.rng == cur.rng) &&
523 		    (prev.dsr == cur.dsr) &&
524 		    (prev.dcd == cur.dcd) &&
525 		    (prev.cts == cur.cts))
526 			return -EIO;
527 
528 		if ((arg & TIOCM_RNG && (prev.rng != cur.rng)) ||
529 		    (arg & TIOCM_DSR && (prev.dsr != cur.dsr)) ||
530 		    (arg & TIOCM_CD && (prev.dcd != cur.dcd)) ||
531 		    (arg & TIOCM_CTS && (prev.cts != cur.cts)))
532 			return 0;
533 	}
534 	return 0;
535 }
536 
537 static int qt2_get_icount(struct tty_struct *tty,
538 			  struct serial_icounter_struct *icount)
539 {
540 	struct usb_serial_port *port = tty->driver_data;
541 	struct qt2_port_private *priv = usb_get_serial_port_data(port);
542 	struct async_icount cnow = priv->icount;
543 
544 	icount->cts = cnow.cts;
545 	icount->dsr = cnow.dsr;
546 	icount->rng = cnow.rng;
547 	icount->dcd = cnow.dcd;
548 	icount->rx = cnow.rx;
549 	icount->tx = cnow.tx;
550 	icount->frame = cnow.frame;
551 	icount->overrun = cnow.overrun;
552 	icount->parity = cnow.parity;
553 	icount->brk = cnow.brk;
554 	icount->buf_overrun = cnow.buf_overrun;
555 
556 	return 0;
557 }
558 
559 static int qt2_ioctl(struct tty_struct *tty,
560 		     unsigned int cmd, unsigned long arg)
561 {
562 	struct usb_serial_port *port = tty->driver_data;
563 
564 	switch (cmd) {
565 	case TIOCGSERIAL:
566 		return get_serial_info(port,
567 				       (struct serial_struct __user *)arg);
568 
569 	case TIOCMIWAIT:
570 		return wait_modem_info(port, arg);
571 
572 	default:
573 		break;
574 	}
575 
576 	return -ENOIOCTLCMD;
577 }
578 
579 static void qt2_process_status(struct usb_serial_port *port, unsigned char *ch)
580 {
581 	switch (*ch) {
582 	case QT2_LINE_STATUS:
583 		qt2_update_lsr(port, ch + 1);
584 		break;
585 	case QT2_MODEM_STATUS:
586 		qt2_update_msr(port, ch + 1);
587 		break;
588 	}
589 }
590 
591 /* not needed, kept to document functionality */
592 static void qt2_process_xmit_empty(struct usb_serial_port *port,
593 				   unsigned char *ch)
594 {
595 	int bytes_written;
596 
597 	bytes_written = (int)(*ch) + (int)(*(ch + 1) << 4);
598 }
599 
600 /* not needed, kept to document functionality */
601 static void qt2_process_flush(struct usb_serial_port *port, unsigned char *ch)
602 {
603 	return;
604 }
605 
606 void qt2_process_read_urb(struct urb *urb)
607 {
608 	struct usb_serial *serial;
609 	struct qt2_serial_private *serial_priv;
610 	struct usb_serial_port *port;
611 	struct qt2_port_private *port_priv;
612 	bool escapeflag;
613 	unsigned char *ch;
614 	int i;
615 	unsigned char newport;
616 	int len = urb->actual_length;
617 
618 	if (!len)
619 		return;
620 
621 	ch = urb->transfer_buffer;
622 	serial = urb->context;
623 	serial_priv = usb_get_serial_data(serial);
624 	port = serial->port[serial_priv->current_port];
625 	port_priv = usb_get_serial_port_data(port);
626 
627 	for (i = 0; i < urb->actual_length; i++) {
628 		ch = (unsigned char *)urb->transfer_buffer + i;
629 		if ((i <= (len - 3)) &&
630 		    (*ch == QT2_CONTROL_BYTE) &&
631 		    (*(ch + 1) == QT2_CONTROL_BYTE)) {
632 			escapeflag = false;
633 			switch (*(ch + 2)) {
634 			case QT2_LINE_STATUS:
635 			case QT2_MODEM_STATUS:
636 				if (i > (len - 4)) {
637 					dev_warn(&port->dev,
638 						 "%s - status message too short\n",
639 						__func__);
640 					break;
641 				}
642 				qt2_process_status(port, ch + 2);
643 				i += 3;
644 				escapeflag = true;
645 				break;
646 			case QT2_XMIT_HOLD:
647 				if (i > (len - 5)) {
648 					dev_warn(&port->dev,
649 						 "%s - xmit_empty message too short\n",
650 						 __func__);
651 					break;
652 				}
653 				qt2_process_xmit_empty(port, ch + 3);
654 				i += 4;
655 				escapeflag = true;
656 				break;
657 			case QT2_CHANGE_PORT:
658 				if (i > (len - 4)) {
659 					dev_warn(&port->dev,
660 						 "%s - change_port message too short\n",
661 						 __func__);
662 					break;
663 				}
664 				tty_flip_buffer_push(&port->port);
665 
666 				newport = *(ch + 3);
667 
668 				if (newport > serial->num_ports) {
669 					dev_err(&port->dev,
670 						"%s - port change to invalid port: %i\n",
671 						__func__, newport);
672 					break;
673 				}
674 
675 				serial_priv->current_port = newport;
676 				port = serial->port[serial_priv->current_port];
677 				port_priv = usb_get_serial_port_data(port);
678 				i += 3;
679 				escapeflag = true;
680 				break;
681 			case QT2_REC_FLUSH:
682 			case QT2_XMIT_FLUSH:
683 				qt2_process_flush(port, ch + 2);
684 				i += 2;
685 				escapeflag = true;
686 				break;
687 			case QT2_CONTROL_ESCAPE:
688 				tty_buffer_request_room(&port->port, 2);
689 				tty_insert_flip_string(&port->port, ch, 2);
690 				i += 2;
691 				escapeflag = true;
692 				break;
693 			default:
694 				dev_warn(&port->dev,
695 					 "%s - unsupported command %i\n",
696 					 __func__, *(ch + 2));
697 				break;
698 			}
699 			if (escapeflag)
700 				continue;
701 		}
702 
703 		tty_buffer_request_room(&port->port, 1);
704 		tty_insert_flip_string(&port->port, ch, 1);
705 	}
706 
707 	tty_flip_buffer_push(&port->port);
708 }
709 
710 static void qt2_write_bulk_callback(struct urb *urb)
711 {
712 	struct usb_serial_port *port;
713 	struct qt2_port_private *port_priv;
714 
715 	port = urb->context;
716 	port_priv = usb_get_serial_port_data(port);
717 
718 	spin_lock(&port_priv->urb_lock);
719 
720 	port_priv->urb_in_use = false;
721 	usb_serial_port_softint(port);
722 
723 	spin_unlock(&port_priv->urb_lock);
724 
725 }
726 
727 static void qt2_read_bulk_callback(struct urb *urb)
728 {
729 	struct usb_serial *serial = urb->context;
730 	int status;
731 
732 	if (urb->status) {
733 		dev_warn(&serial->dev->dev,
734 			 "%s - non-zero urb status: %i\n", __func__,
735 			 urb->status);
736 		return;
737 	}
738 
739 	qt2_process_read_urb(urb);
740 
741 	status = usb_submit_urb(urb, GFP_ATOMIC);
742 	if (status != 0)
743 		dev_err(&serial->dev->dev,
744 			"%s - resubmit read urb failed: %i\n",
745 			__func__, status);
746 }
747 
748 static int qt2_setup_urbs(struct usb_serial *serial)
749 {
750 	struct usb_serial_port *port0;
751 	struct qt2_serial_private *serial_priv;
752 	int status;
753 
754 	port0 = serial->port[0];
755 
756 	serial_priv = usb_get_serial_data(serial);
757 	serial_priv->read_urb = usb_alloc_urb(0, GFP_KERNEL);
758 	if (!serial_priv->read_urb) {
759 		dev_err(&serial->dev->dev, "No free urbs available\n");
760 		return -ENOMEM;
761 	}
762 
763 	usb_fill_bulk_urb(serial_priv->read_urb, serial->dev,
764 			  usb_rcvbulkpipe(serial->dev,
765 					  port0->bulk_in_endpointAddress),
766 			  serial_priv->read_buffer,
767 			  sizeof(serial_priv->read_buffer),
768 			  qt2_read_bulk_callback, serial);
769 
770 	status = usb_submit_urb(serial_priv->read_urb, GFP_KERNEL);
771 	if (status != 0) {
772 		dev_err(&serial->dev->dev,
773 			"%s - submit read urb failed %i\n", __func__, status);
774 		usb_free_urb(serial_priv->read_urb);
775 		return status;
776 	}
777 
778 	return 0;
779 }
780 
781 static int qt2_attach(struct usb_serial *serial)
782 {
783 	struct qt2_serial_private *serial_priv;
784 	int status;
785 
786 	/* power on unit */
787 	status = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
788 				 0xc2, 0x40, 0x8000, 0, NULL, 0,
789 				 QT2_USB_TIMEOUT);
790 	if (status < 0) {
791 		dev_err(&serial->dev->dev,
792 			"%s - failed to power on unit: %i\n", __func__, status);
793 		return status;
794 	}
795 
796 	serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL);
797 	if (!serial_priv) {
798 		dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
799 		return -ENOMEM;
800 	}
801 
802 	usb_set_serial_data(serial, serial_priv);
803 
804 	status = qt2_setup_urbs(serial);
805 	if (status != 0)
806 		goto attach_failed;
807 
808 	return 0;
809 
810 attach_failed:
811 	kfree(serial_priv);
812 	return status;
813 }
814 
815 static int qt2_port_probe(struct usb_serial_port *port)
816 {
817 	struct usb_serial *serial = port->serial;
818 	struct qt2_port_private *port_priv;
819 	u8 bEndpointAddress;
820 
821 	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
822 	if (!port_priv)
823 		return -ENOMEM;
824 
825 	spin_lock_init(&port_priv->lock);
826 	spin_lock_init(&port_priv->urb_lock);
827 	init_waitqueue_head(&port_priv->delta_msr_wait);
828 	port_priv->port = port;
829 
830 	port_priv->write_urb = usb_alloc_urb(0, GFP_KERNEL);
831 	if (!port_priv->write_urb) {
832 		kfree(port_priv);
833 		return -ENOMEM;
834 	}
835 	bEndpointAddress = serial->port[0]->bulk_out_endpointAddress;
836 	usb_fill_bulk_urb(port_priv->write_urb, serial->dev,
837 				usb_sndbulkpipe(serial->dev, bEndpointAddress),
838 				port_priv->write_buffer,
839 				sizeof(port_priv->write_buffer),
840 				qt2_write_bulk_callback, port);
841 
842 	usb_set_serial_port_data(port, port_priv);
843 
844 	return 0;
845 }
846 
847 static int qt2_port_remove(struct usb_serial_port *port)
848 {
849 	struct qt2_port_private *port_priv;
850 
851 	port_priv = usb_get_serial_port_data(port);
852 	usb_free_urb(port_priv->write_urb);
853 	kfree(port_priv);
854 
855 	return 0;
856 }
857 
858 static int qt2_tiocmget(struct tty_struct *tty)
859 {
860 	struct usb_serial_port *port = tty->driver_data;
861 	struct usb_device *dev = port->serial->dev;
862 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
863 	u8 *d;
864 	int r;
865 
866 	d = kzalloc(2, GFP_KERNEL);
867 	if (!d)
868 		return -ENOMEM;
869 
870 	r = qt2_getregister(dev, port_priv->device_port, UART_MCR, d);
871 	if (r < 0)
872 		goto mget_out;
873 
874 	r = qt2_getregister(dev, port_priv->device_port, UART_MSR, d + 1);
875 	if (r < 0)
876 		goto mget_out;
877 
878 	r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) |
879 	    (d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) |
880 	    (d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) |
881 	    (d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) |
882 	    (d[1] & UART_MSR_RI ? TIOCM_RI : 0) |
883 	    (d[1] & UART_MSR_DSR ? TIOCM_DSR : 0);
884 
885 mget_out:
886 	kfree(d);
887 	return r;
888 }
889 
890 static int qt2_tiocmset(struct tty_struct *tty,
891 			unsigned int set, unsigned int clear)
892 {
893 	struct qt2_port_private *port_priv;
894 
895 	port_priv = usb_get_serial_port_data(tty->driver_data);
896 	return update_mctrl(port_priv, set, clear);
897 }
898 
899 static void qt2_break_ctl(struct tty_struct *tty, int break_state)
900 {
901 	struct usb_serial_port *port = tty->driver_data;
902 	struct qt2_port_private *port_priv;
903 	int status;
904 	u16 val;
905 
906 	port_priv = usb_get_serial_port_data(port);
907 
908 	if (!port_priv->is_open) {
909 		dev_err(&port->dev,
910 			"%s - port is not open\n", __func__);
911 		return;
912 	}
913 
914 	val = (break_state == -1) ? 1 : 0;
915 
916 	status = qt2_control_msg(port->serial->dev, QT2_BREAK_CONTROL,
917 				 val, port_priv->device_port);
918 	if (status < 0)
919 		dev_warn(&port->dev,
920 			 "%s - failed to send control message: %i\n", __func__,
921 			 status);
922 }
923 
924 
925 
926 static void qt2_dtr_rts(struct usb_serial_port *port, int on)
927 {
928 	struct usb_device *dev = port->serial->dev;
929 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
930 
931 	/* Disable flow control */
932 	if (!on) {
933 		if (qt2_setregister(dev, port_priv->device_port,
934 					   UART_MCR, 0) < 0)
935 			dev_warn(&port->dev, "error from flowcontrol urb\n");
936 	}
937 	/* drop RTS and DTR */
938 	if (on)
939 		update_mctrl(port_priv, TIOCM_DTR | TIOCM_RTS, 0);
940 	else
941 		update_mctrl(port_priv, 0, TIOCM_DTR | TIOCM_RTS);
942 }
943 
944 static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch)
945 {
946 	struct qt2_port_private *port_priv;
947 	u8 newMSR = (u8) *ch;
948 	unsigned long flags;
949 
950 	port_priv = usb_get_serial_port_data(port);
951 
952 	spin_lock_irqsave(&port_priv->lock, flags);
953 	port_priv->shadowMSR = newMSR;
954 	spin_unlock_irqrestore(&port_priv->lock, flags);
955 
956 	if (newMSR & UART_MSR_ANY_DELTA) {
957 		/* update input line counters */
958 		if (newMSR & UART_MSR_DCTS)
959 			port_priv->icount.cts++;
960 
961 		if (newMSR & UART_MSR_DDSR)
962 			port_priv->icount.dsr++;
963 
964 		if (newMSR & UART_MSR_DDCD)
965 			port_priv->icount.dcd++;
966 
967 		if (newMSR & UART_MSR_TERI)
968 			port_priv->icount.rng++;
969 
970 		wake_up_interruptible(&port_priv->delta_msr_wait);
971 	}
972 }
973 
974 static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch)
975 {
976 	struct qt2_port_private *port_priv;
977 	struct async_icount *icount;
978 	unsigned long flags;
979 	u8 newLSR = (u8) *ch;
980 
981 	port_priv = usb_get_serial_port_data(port);
982 
983 	if (newLSR & UART_LSR_BI)
984 		newLSR &= (u8) (UART_LSR_OE | UART_LSR_BI);
985 
986 	spin_lock_irqsave(&port_priv->lock, flags);
987 	port_priv->shadowLSR = newLSR;
988 	spin_unlock_irqrestore(&port_priv->lock, flags);
989 
990 	icount = &port_priv->icount;
991 
992 	if (newLSR & UART_LSR_BRK_ERROR_BITS) {
993 
994 		if (newLSR & UART_LSR_BI)
995 			icount->brk++;
996 
997 		if (newLSR & UART_LSR_OE)
998 			icount->overrun++;
999 
1000 		if (newLSR & UART_LSR_PE)
1001 			icount->parity++;
1002 
1003 		if (newLSR & UART_LSR_FE)
1004 			icount->frame++;
1005 	}
1006 
1007 }
1008 
1009 static int qt2_write_room(struct tty_struct *tty)
1010 {
1011 	struct usb_serial_port *port = tty->driver_data;
1012 	struct qt2_port_private *port_priv;
1013 	unsigned long flags = 0;
1014 	int r;
1015 
1016 	port_priv = usb_get_serial_port_data(port);
1017 
1018 	spin_lock_irqsave(&port_priv->urb_lock, flags);
1019 
1020 	if (port_priv->urb_in_use)
1021 		r = 0;
1022 	else
1023 		r = QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE;
1024 
1025 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
1026 
1027 	return r;
1028 }
1029 
1030 static int qt2_write(struct tty_struct *tty,
1031 		     struct usb_serial_port *port,
1032 		     const unsigned char *buf, int count)
1033 {
1034 	struct qt2_port_private *port_priv;
1035 	struct urb *write_urb;
1036 	unsigned char *data;
1037 	unsigned long flags;
1038 	int status;
1039 	int bytes_out = 0;
1040 
1041 	port_priv = usb_get_serial_port_data(port);
1042 
1043 	if (port_priv->write_urb == NULL) {
1044 		dev_err(&port->dev, "%s - no output urb\n", __func__);
1045 		return 0;
1046 	}
1047 	write_urb = port_priv->write_urb;
1048 
1049 	count = min(count, QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE);
1050 
1051 	data = write_urb->transfer_buffer;
1052 	spin_lock_irqsave(&port_priv->urb_lock, flags);
1053 	if (port_priv->urb_in_use == true) {
1054 		dev_err(&port->dev, "qt2_write - urb is in use\n");
1055 		goto write_out;
1056 	}
1057 
1058 	*data++ = QT2_CONTROL_BYTE;
1059 	*data++ = QT2_CONTROL_BYTE;
1060 	*data++ = port_priv->device_port;
1061 	put_unaligned_le16(count, data);
1062 	data += 2;
1063 	memcpy(data, buf, count);
1064 
1065 	write_urb->transfer_buffer_length = count + QT2_WRITE_CONTROL_SIZE;
1066 
1067 	status = usb_submit_urb(write_urb, GFP_ATOMIC);
1068 	if (status == 0) {
1069 		port_priv->urb_in_use = true;
1070 		bytes_out += count;
1071 	}
1072 
1073 write_out:
1074 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
1075 	return bytes_out;
1076 }
1077 
1078 
1079 static struct usb_serial_driver qt2_device = {
1080 	.driver = {
1081 		.owner = THIS_MODULE,
1082 		.name = "quatech-serial",
1083 	},
1084 	.description	     = DRIVER_DESC,
1085 	.id_table	     = id_table,
1086 	.open		     = qt2_open,
1087 	.close		     = qt2_close,
1088 	.write               = qt2_write,
1089 	.write_room          = qt2_write_room,
1090 	.calc_num_ports      = qt2_calc_num_ports,
1091 	.attach              = qt2_attach,
1092 	.release             = qt2_release,
1093 	.disconnect          = qt2_disconnect,
1094 	.port_probe          = qt2_port_probe,
1095 	.port_remove         = qt2_port_remove,
1096 	.dtr_rts             = qt2_dtr_rts,
1097 	.break_ctl           = qt2_break_ctl,
1098 	.tiocmget            = qt2_tiocmget,
1099 	.tiocmset            = qt2_tiocmset,
1100 	.get_icount	     = qt2_get_icount,
1101 	.ioctl               = qt2_ioctl,
1102 	.set_termios         = qt2_set_termios,
1103 };
1104 
1105 static struct usb_serial_driver *const serial_drivers[] = {
1106 	&qt2_device, NULL
1107 };
1108 
1109 module_usb_serial_driver(serial_drivers, id_table);
1110 
1111 MODULE_DESCRIPTION(DRIVER_DESC);
1112 MODULE_LICENSE("GPL");
1113