xref: /openbmc/linux/drivers/usb/serial/quatech2.c (revision 5bd8e16d)
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_READ_BUFFER_SIZE    512  /* size of read buffer */
66 #define QT2_WRITE_BUFFER_SIZE   512  /* size of write buffer */
67 #define QT2_WRITE_CONTROL_SIZE  5    /* control bytes used for a write */
68 
69 #define DRIVER_DESC "Quatech 2nd gen USB to Serial Driver"
70 
71 #define	USB_VENDOR_ID_QUATECH	0x061d
72 #define QUATECH_SSU2_100	0xC120	/* RS232 single port */
73 #define QUATECH_DSU2_100	0xC140	/* RS232 dual port */
74 #define QUATECH_DSU2_400	0xC150	/* RS232/422/485 dual port */
75 #define QUATECH_QSU2_100	0xC160	/* RS232 four port */
76 #define QUATECH_QSU2_400	0xC170	/* RS232/422/485 four port */
77 #define QUATECH_ESU2_100	0xC1A0	/* RS232 eight port */
78 #define QUATECH_ESU2_400	0xC180	/* RS232/422/485 eight port */
79 
80 struct qt2_device_detail {
81 	int product_id;
82 	int num_ports;
83 };
84 
85 #define QT_DETAILS(prod, ports)	\
86 	.product_id = (prod),   \
87 	.num_ports = (ports)
88 
89 static const struct qt2_device_detail qt2_device_details[] = {
90 	{QT_DETAILS(QUATECH_SSU2_100, 1)},
91 	{QT_DETAILS(QUATECH_DSU2_400, 2)},
92 	{QT_DETAILS(QUATECH_DSU2_100, 2)},
93 	{QT_DETAILS(QUATECH_QSU2_400, 4)},
94 	{QT_DETAILS(QUATECH_QSU2_100, 4)},
95 	{QT_DETAILS(QUATECH_ESU2_400, 8)},
96 	{QT_DETAILS(QUATECH_ESU2_100, 8)},
97 	{QT_DETAILS(0, 0)}	/* Terminating entry */
98 };
99 
100 static const struct usb_device_id id_table[] = {
101 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_SSU2_100)},
102 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_100)},
103 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_400)},
104 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_100)},
105 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_400)},
106 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_100)},
107 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_400)},
108 	{}			/* Terminating entry */
109 };
110 MODULE_DEVICE_TABLE(usb, id_table);
111 
112 struct qt2_serial_private {
113 	unsigned char current_port;  /* current port for incoming data */
114 
115 	struct urb	*read_urb;   /* shared among all ports */
116 	char		*read_buffer;
117 };
118 
119 struct qt2_port_private {
120 	u8   device_port;
121 
122 	spinlock_t urb_lock;
123 	bool       urb_in_use;
124 	struct urb *write_urb;
125 	char       *write_buffer;
126 
127 	spinlock_t  lock;
128 	u8          shadowLSR;
129 	u8          shadowMSR;
130 
131 	struct usb_serial_port *port;
132 };
133 
134 static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch);
135 static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch);
136 static void qt2_write_bulk_callback(struct urb *urb);
137 static void qt2_read_bulk_callback(struct urb *urb);
138 
139 static void qt2_release(struct usb_serial *serial)
140 {
141 	struct qt2_serial_private *serial_priv;
142 
143 	serial_priv = usb_get_serial_data(serial);
144 
145 	usb_free_urb(serial_priv->read_urb);
146 	kfree(serial_priv->read_buffer);
147 	kfree(serial_priv);
148 }
149 
150 static inline int calc_baud_divisor(int baudrate)
151 {
152 	int divisor, rem;
153 
154 	divisor = MAX_BAUD_RATE / baudrate;
155 	rem = MAX_BAUD_RATE % baudrate;
156 	/* Round to nearest divisor */
157 	if (((rem * 2) >= baudrate) && (baudrate != 110))
158 		divisor++;
159 
160 	return divisor;
161 }
162 
163 static inline int qt2_set_port_config(struct usb_device *dev,
164 				      unsigned char port_number,
165 				      u16 baudrate, u16 lcr)
166 {
167 	int divisor = calc_baud_divisor(baudrate);
168 	u16 index = ((u16) (lcr << 8) | (u16) (port_number));
169 
170 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
171 			       QT2_GET_SET_UART, 0x40,
172 			       divisor, index, NULL, 0, QT2_USB_TIMEOUT);
173 }
174 
175 static inline int qt2_control_msg(struct usb_device *dev,
176 				  u8 request, u16 data, u16 index)
177 {
178 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
179 			       request, 0x40, data, index,
180 			       NULL, 0, QT2_USB_TIMEOUT);
181 }
182 
183 static inline int qt2_setdevice(struct usb_device *dev, u8 *data)
184 {
185 	u16 x = ((u16) (data[1] << 8) | (u16) (data[0]));
186 
187 	return qt2_control_msg(dev, QT_SET_GET_DEVICE, x, 0);
188 }
189 
190 
191 static inline int qt2_getdevice(struct usb_device *dev, u8 *data)
192 {
193 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
194 			       QT_SET_GET_DEVICE, 0xc0, 0, 0,
195 			       data, 3, QT2_USB_TIMEOUT);
196 }
197 
198 static inline int qt2_getregister(struct usb_device *dev,
199 				  u8 uart,
200 				  u8 reg,
201 				  u8 *data)
202 {
203 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
204 			       QT_SET_GET_REGISTER, 0xc0, reg,
205 			       uart, data, sizeof(*data), QT2_USB_TIMEOUT);
206 
207 }
208 
209 static inline int qt2_setregister(struct usb_device *dev,
210 				  u8 uart, u8 reg, u16 data)
211 {
212 	u16 value = (data << 8) | reg;
213 
214 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
215 			       QT_SET_GET_REGISTER, 0x40, value, uart,
216 			       NULL, 0, QT2_USB_TIMEOUT);
217 }
218 
219 static inline int update_mctrl(struct qt2_port_private *port_priv,
220 			       unsigned int set, unsigned int clear)
221 {
222 	struct usb_serial_port *port = port_priv->port;
223 	struct usb_device *dev = port->serial->dev;
224 	unsigned urb_value;
225 	int status;
226 
227 	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0) {
228 		dev_dbg(&port->dev,
229 			"update_mctrl - DTR|RTS not being set|cleared\n");
230 		return 0;	/* no change */
231 	}
232 
233 	clear &= ~set;	/* 'set' takes precedence over 'clear' */
234 	urb_value = 0;
235 	if (set & TIOCM_DTR)
236 		urb_value |= UART_MCR_DTR;
237 	if (set & TIOCM_RTS)
238 		urb_value |= UART_MCR_RTS;
239 
240 	status = qt2_setregister(dev, port_priv->device_port, UART_MCR,
241 				 urb_value);
242 	if (status < 0)
243 		dev_err(&port->dev,
244 			"update_mctrl - Error from MODEM_CTRL urb: %i\n",
245 			status);
246 	return status;
247 }
248 
249 static int qt2_calc_num_ports(struct usb_serial *serial)
250 {
251 	struct qt2_device_detail d;
252 	int i;
253 
254 	for (i = 0; d = qt2_device_details[i], d.product_id != 0; i++) {
255 		if (d.product_id == le16_to_cpu(serial->dev->descriptor.idProduct))
256 			return d.num_ports;
257 	}
258 
259 	/* we didn't recognize the device */
260 	dev_err(&serial->dev->dev,
261 		 "don't know the number of ports, assuming 1\n");
262 
263 	return 1;
264 }
265 
266 static void qt2_set_termios(struct tty_struct *tty,
267 			    struct usb_serial_port *port,
268 			    struct ktermios *old_termios)
269 {
270 	struct usb_device *dev = port->serial->dev;
271 	struct qt2_port_private *port_priv;
272 	struct ktermios *termios = &tty->termios;
273 	u16 baud;
274 	unsigned int cflag = termios->c_cflag;
275 	u16 new_lcr = 0;
276 	int status;
277 
278 	port_priv = usb_get_serial_port_data(port);
279 
280 	if (cflag & PARENB) {
281 		if (cflag & PARODD)
282 			new_lcr |= UART_LCR_PARITY;
283 		else
284 			new_lcr |= SERIAL_EVEN_PARITY;
285 	}
286 
287 	switch (cflag & CSIZE) {
288 	case CS5:
289 		new_lcr |= UART_LCR_WLEN5;
290 		break;
291 	case CS6:
292 		new_lcr |= UART_LCR_WLEN6;
293 		break;
294 	case CS7:
295 		new_lcr |= UART_LCR_WLEN7;
296 		break;
297 	default:
298 	case CS8:
299 		new_lcr |= UART_LCR_WLEN8;
300 		break;
301 	}
302 
303 	baud = tty_get_baud_rate(tty);
304 	if (!baud)
305 		baud = 9600;
306 
307 	status = qt2_set_port_config(dev, port_priv->device_port, baud,
308 				     new_lcr);
309 	if (status < 0)
310 		dev_err(&port->dev, "%s - qt2_set_port_config failed: %i\n",
311 			__func__, status);
312 
313 	if (cflag & CRTSCTS)
314 		status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
315 					 SERIAL_CRTSCTS,
316 					 port_priv->device_port);
317 	else
318 		status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
319 					 0, port_priv->device_port);
320 	if (status < 0)
321 		dev_err(&port->dev, "%s - set HW flow control failed: %i\n",
322 			__func__, status);
323 
324 	if (I_IXOFF(tty) || I_IXON(tty)) {
325 		u16 x = ((u16) (START_CHAR(tty) << 8) | (u16) (STOP_CHAR(tty)));
326 
327 		status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
328 					 x, port_priv->device_port);
329 	} else
330 		status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
331 					 0, port_priv->device_port);
332 
333 	if (status < 0)
334 		dev_err(&port->dev, "%s - set SW flow control failed: %i\n",
335 			__func__, status);
336 
337 }
338 
339 static int qt2_open(struct tty_struct *tty, struct usb_serial_port *port)
340 {
341 	struct usb_serial *serial;
342 	struct qt2_port_private *port_priv;
343 	u8 *data;
344 	u16 device_port;
345 	int status;
346 	unsigned long flags;
347 
348 	device_port = port->port_number;
349 
350 	serial = port->serial;
351 
352 	port_priv = usb_get_serial_port_data(port);
353 
354 	/* set the port to RS232 mode */
355 	status = qt2_control_msg(serial->dev, QT2_GET_SET_QMCR,
356 				 QT2_QMCR_RS232, device_port);
357 	if (status < 0) {
358 		dev_err(&port->dev,
359 			"%s failed to set RS232 mode for port %i error %i\n",
360 			__func__, device_port, status);
361 		return status;
362 	}
363 
364 	data = kzalloc(2, GFP_KERNEL);
365 	if (!data)
366 		return -ENOMEM;
367 
368 	/* open the port */
369 	status = usb_control_msg(serial->dev,
370 				 usb_rcvctrlpipe(serial->dev, 0),
371 				 QT_OPEN_CLOSE_CHANNEL,
372 				 0xc0, 0,
373 				 device_port, data, 2, QT2_USB_TIMEOUT);
374 
375 	if (status < 0) {
376 		dev_err(&port->dev, "%s - open port failed %i", __func__,
377 			status);
378 		kfree(data);
379 		return status;
380 	}
381 
382 	spin_lock_irqsave(&port_priv->lock, flags);
383 	port_priv->shadowLSR = data[0];
384 	port_priv->shadowMSR = data[1];
385 	spin_unlock_irqrestore(&port_priv->lock, flags);
386 
387 	kfree(data);
388 
389 	/* set to default speed and 8bit word size */
390 	status = qt2_set_port_config(serial->dev, device_port,
391 				     DEFAULT_BAUD_RATE, UART_LCR_WLEN8);
392 	if (status < 0) {
393 		dev_err(&port->dev, "%s - initial setup failed (%i)\n",
394 			__func__, device_port);
395 		return status;
396 	}
397 
398 	port_priv->device_port = (u8) device_port;
399 
400 	if (tty)
401 		qt2_set_termios(tty, port, &tty->termios);
402 
403 	return 0;
404 
405 }
406 
407 static void qt2_close(struct usb_serial_port *port)
408 {
409 	struct usb_serial *serial;
410 	struct qt2_port_private *port_priv;
411 	unsigned long flags;
412 	int i;
413 
414 	serial = port->serial;
415 	port_priv = usb_get_serial_port_data(port);
416 
417 	spin_lock_irqsave(&port_priv->urb_lock, flags);
418 	usb_kill_urb(port_priv->write_urb);
419 	port_priv->urb_in_use = false;
420 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
421 
422 	/* flush the port transmit buffer */
423 	i = usb_control_msg(serial->dev,
424 			    usb_rcvctrlpipe(serial->dev, 0),
425 			    QT2_FLUSH_DEVICE, 0x40, 1,
426 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
427 
428 	if (i < 0)
429 		dev_err(&port->dev, "%s - transmit buffer flush failed: %i\n",
430 			__func__, i);
431 
432 	/* flush the port receive buffer */
433 	i = usb_control_msg(serial->dev,
434 			    usb_rcvctrlpipe(serial->dev, 0),
435 			    QT2_FLUSH_DEVICE, 0x40, 0,
436 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
437 
438 	if (i < 0)
439 		dev_err(&port->dev, "%s - receive buffer flush failed: %i\n",
440 			__func__, i);
441 
442 	/* close the port */
443 	i = usb_control_msg(serial->dev,
444 			    usb_sndctrlpipe(serial->dev, 0),
445 			    QT_OPEN_CLOSE_CHANNEL,
446 			    0x40, 0,
447 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
448 
449 	if (i < 0)
450 		dev_err(&port->dev, "%s - close port failed %i\n",
451 			__func__, i);
452 }
453 
454 static void qt2_disconnect(struct usb_serial *serial)
455 {
456 	struct qt2_serial_private *serial_priv = usb_get_serial_data(serial);
457 
458 	usb_kill_urb(serial_priv->read_urb);
459 }
460 
461 static int get_serial_info(struct usb_serial_port *port,
462 			   struct serial_struct __user *retinfo)
463 {
464 	struct serial_struct tmp;
465 
466 	if (!retinfo)
467 		return -EFAULT;
468 
469 	memset(&tmp, 0, sizeof(tmp));
470 	tmp.line		= port->minor;
471 	tmp.port		= 0;
472 	tmp.irq			= 0;
473 	tmp.flags		= ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
474 	tmp.xmit_fifo_size	= port->bulk_out_size;
475 	tmp.baud_base		= 9600;
476 	tmp.close_delay		= 5*HZ;
477 	tmp.closing_wait	= 30*HZ;
478 
479 	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
480 		return -EFAULT;
481 	return 0;
482 }
483 
484 static int qt2_ioctl(struct tty_struct *tty,
485 		     unsigned int cmd, unsigned long arg)
486 {
487 	struct usb_serial_port *port = tty->driver_data;
488 
489 	switch (cmd) {
490 	case TIOCGSERIAL:
491 		return get_serial_info(port,
492 				       (struct serial_struct __user *)arg);
493 	default:
494 		break;
495 	}
496 
497 	return -ENOIOCTLCMD;
498 }
499 
500 static void qt2_process_status(struct usb_serial_port *port, unsigned char *ch)
501 {
502 	switch (*ch) {
503 	case QT2_LINE_STATUS:
504 		qt2_update_lsr(port, ch + 1);
505 		break;
506 	case QT2_MODEM_STATUS:
507 		qt2_update_msr(port, ch + 1);
508 		break;
509 	}
510 }
511 
512 /* not needed, kept to document functionality */
513 static void qt2_process_xmit_empty(struct usb_serial_port *port,
514 				   unsigned char *ch)
515 {
516 	int bytes_written;
517 
518 	bytes_written = (int)(*ch) + (int)(*(ch + 1) << 4);
519 }
520 
521 /* not needed, kept to document functionality */
522 static void qt2_process_flush(struct usb_serial_port *port, unsigned char *ch)
523 {
524 	return;
525 }
526 
527 static void qt2_process_read_urb(struct urb *urb)
528 {
529 	struct usb_serial *serial;
530 	struct qt2_serial_private *serial_priv;
531 	struct usb_serial_port *port;
532 	struct qt2_port_private *port_priv;
533 	bool escapeflag;
534 	unsigned char *ch;
535 	int i;
536 	unsigned char newport;
537 	int len = urb->actual_length;
538 
539 	if (!len)
540 		return;
541 
542 	ch = urb->transfer_buffer;
543 	serial = urb->context;
544 	serial_priv = usb_get_serial_data(serial);
545 	port = serial->port[serial_priv->current_port];
546 	port_priv = usb_get_serial_port_data(port);
547 
548 	for (i = 0; i < urb->actual_length; i++) {
549 		ch = (unsigned char *)urb->transfer_buffer + i;
550 		if ((i <= (len - 3)) &&
551 		    (*ch == QT2_CONTROL_BYTE) &&
552 		    (*(ch + 1) == QT2_CONTROL_BYTE)) {
553 			escapeflag = false;
554 			switch (*(ch + 2)) {
555 			case QT2_LINE_STATUS:
556 			case QT2_MODEM_STATUS:
557 				if (i > (len - 4)) {
558 					dev_warn(&port->dev,
559 						 "%s - status message too short\n",
560 						__func__);
561 					break;
562 				}
563 				qt2_process_status(port, ch + 2);
564 				i += 3;
565 				escapeflag = true;
566 				break;
567 			case QT2_XMIT_HOLD:
568 				if (i > (len - 5)) {
569 					dev_warn(&port->dev,
570 						 "%s - xmit_empty message too short\n",
571 						 __func__);
572 					break;
573 				}
574 				qt2_process_xmit_empty(port, ch + 3);
575 				i += 4;
576 				escapeflag = true;
577 				break;
578 			case QT2_CHANGE_PORT:
579 				if (i > (len - 4)) {
580 					dev_warn(&port->dev,
581 						 "%s - change_port message too short\n",
582 						 __func__);
583 					break;
584 				}
585 				tty_flip_buffer_push(&port->port);
586 
587 				newport = *(ch + 3);
588 
589 				if (newport > serial->num_ports) {
590 					dev_err(&port->dev,
591 						"%s - port change to invalid port: %i\n",
592 						__func__, newport);
593 					break;
594 				}
595 
596 				serial_priv->current_port = newport;
597 				port = serial->port[serial_priv->current_port];
598 				port_priv = usb_get_serial_port_data(port);
599 				i += 3;
600 				escapeflag = true;
601 				break;
602 			case QT2_REC_FLUSH:
603 			case QT2_XMIT_FLUSH:
604 				qt2_process_flush(port, ch + 2);
605 				i += 2;
606 				escapeflag = true;
607 				break;
608 			case QT2_CONTROL_ESCAPE:
609 				tty_buffer_request_room(&port->port, 2);
610 				tty_insert_flip_string(&port->port, ch, 2);
611 				i += 2;
612 				escapeflag = true;
613 				break;
614 			default:
615 				dev_warn(&port->dev,
616 					 "%s - unsupported command %i\n",
617 					 __func__, *(ch + 2));
618 				break;
619 			}
620 			if (escapeflag)
621 				continue;
622 		}
623 
624 		tty_buffer_request_room(&port->port, 1);
625 		tty_insert_flip_string(&port->port, ch, 1);
626 	}
627 
628 	tty_flip_buffer_push(&port->port);
629 }
630 
631 static void qt2_write_bulk_callback(struct urb *urb)
632 {
633 	struct usb_serial_port *port;
634 	struct qt2_port_private *port_priv;
635 
636 	port = urb->context;
637 	port_priv = usb_get_serial_port_data(port);
638 
639 	spin_lock(&port_priv->urb_lock);
640 
641 	port_priv->urb_in_use = false;
642 	usb_serial_port_softint(port);
643 
644 	spin_unlock(&port_priv->urb_lock);
645 
646 }
647 
648 static void qt2_read_bulk_callback(struct urb *urb)
649 {
650 	struct usb_serial *serial = urb->context;
651 	int status;
652 
653 	if (urb->status) {
654 		dev_warn(&serial->dev->dev,
655 			 "%s - non-zero urb status: %i\n", __func__,
656 			 urb->status);
657 		return;
658 	}
659 
660 	qt2_process_read_urb(urb);
661 
662 	status = usb_submit_urb(urb, GFP_ATOMIC);
663 	if (status != 0)
664 		dev_err(&serial->dev->dev,
665 			"%s - resubmit read urb failed: %i\n",
666 			__func__, status);
667 }
668 
669 static int qt2_setup_urbs(struct usb_serial *serial)
670 {
671 	struct usb_serial_port *port0;
672 	struct qt2_serial_private *serial_priv;
673 	int status;
674 
675 	port0 = serial->port[0];
676 
677 	serial_priv = usb_get_serial_data(serial);
678 	serial_priv->read_urb = usb_alloc_urb(0, GFP_KERNEL);
679 	if (!serial_priv->read_urb) {
680 		dev_err(&serial->dev->dev, "No free urbs available\n");
681 		return -ENOMEM;
682 	}
683 
684 	usb_fill_bulk_urb(serial_priv->read_urb, serial->dev,
685 			  usb_rcvbulkpipe(serial->dev,
686 					  port0->bulk_in_endpointAddress),
687 			  serial_priv->read_buffer,
688 			  QT2_READ_BUFFER_SIZE,
689 			  qt2_read_bulk_callback, serial);
690 
691 	status = usb_submit_urb(serial_priv->read_urb, GFP_KERNEL);
692 	if (status != 0) {
693 		dev_err(&serial->dev->dev,
694 			"%s - submit read urb failed %i\n", __func__, status);
695 		usb_free_urb(serial_priv->read_urb);
696 		return status;
697 	}
698 
699 	return 0;
700 }
701 
702 static int qt2_attach(struct usb_serial *serial)
703 {
704 	struct qt2_serial_private *serial_priv;
705 	int status;
706 
707 	/* power on unit */
708 	status = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
709 				 0xc2, 0x40, 0x8000, 0, NULL, 0,
710 				 QT2_USB_TIMEOUT);
711 	if (status < 0) {
712 		dev_err(&serial->dev->dev,
713 			"%s - failed to power on unit: %i\n", __func__, status);
714 		return status;
715 	}
716 
717 	serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL);
718 	if (!serial_priv) {
719 		dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
720 		return -ENOMEM;
721 	}
722 
723 	serial_priv->read_buffer = kmalloc(QT2_READ_BUFFER_SIZE, GFP_KERNEL);
724 	if (!serial_priv->read_buffer) {
725 		status = -ENOMEM;
726 		goto err_buf;
727 	}
728 
729 	usb_set_serial_data(serial, serial_priv);
730 
731 	status = qt2_setup_urbs(serial);
732 	if (status != 0)
733 		goto attach_failed;
734 
735 	return 0;
736 
737 attach_failed:
738 	kfree(serial_priv->read_buffer);
739 err_buf:
740 	kfree(serial_priv);
741 	return status;
742 }
743 
744 static int qt2_port_probe(struct usb_serial_port *port)
745 {
746 	struct usb_serial *serial = port->serial;
747 	struct qt2_port_private *port_priv;
748 	u8 bEndpointAddress;
749 
750 	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
751 	if (!port_priv)
752 		return -ENOMEM;
753 
754 	spin_lock_init(&port_priv->lock);
755 	spin_lock_init(&port_priv->urb_lock);
756 	port_priv->port = port;
757 
758 	port_priv->write_buffer = kmalloc(QT2_WRITE_BUFFER_SIZE, GFP_KERNEL);
759 	if (!port_priv->write_buffer)
760 		goto err_buf;
761 
762 	port_priv->write_urb = usb_alloc_urb(0, GFP_KERNEL);
763 	if (!port_priv->write_urb)
764 		goto err_urb;
765 
766 	bEndpointAddress = serial->port[0]->bulk_out_endpointAddress;
767 	usb_fill_bulk_urb(port_priv->write_urb, serial->dev,
768 				usb_sndbulkpipe(serial->dev, bEndpointAddress),
769 				port_priv->write_buffer,
770 				QT2_WRITE_BUFFER_SIZE,
771 				qt2_write_bulk_callback, port);
772 
773 	usb_set_serial_port_data(port, port_priv);
774 
775 	return 0;
776 err_urb:
777 	kfree(port_priv->write_buffer);
778 err_buf:
779 	kfree(port_priv);
780 	return -ENOMEM;
781 }
782 
783 static int qt2_port_remove(struct usb_serial_port *port)
784 {
785 	struct qt2_port_private *port_priv;
786 
787 	port_priv = usb_get_serial_port_data(port);
788 	usb_free_urb(port_priv->write_urb);
789 	kfree(port_priv->write_buffer);
790 	kfree(port_priv);
791 
792 	return 0;
793 }
794 
795 static int qt2_tiocmget(struct tty_struct *tty)
796 {
797 	struct usb_serial_port *port = tty->driver_data;
798 	struct usb_device *dev = port->serial->dev;
799 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
800 	u8 *d;
801 	int r;
802 
803 	d = kzalloc(2, GFP_KERNEL);
804 	if (!d)
805 		return -ENOMEM;
806 
807 	r = qt2_getregister(dev, port_priv->device_port, UART_MCR, d);
808 	if (r < 0)
809 		goto mget_out;
810 
811 	r = qt2_getregister(dev, port_priv->device_port, UART_MSR, d + 1);
812 	if (r < 0)
813 		goto mget_out;
814 
815 	r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) |
816 	    (d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) |
817 	    (d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) |
818 	    (d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) |
819 	    (d[1] & UART_MSR_RI ? TIOCM_RI : 0) |
820 	    (d[1] & UART_MSR_DSR ? TIOCM_DSR : 0);
821 
822 mget_out:
823 	kfree(d);
824 	return r;
825 }
826 
827 static int qt2_tiocmset(struct tty_struct *tty,
828 			unsigned int set, unsigned int clear)
829 {
830 	struct qt2_port_private *port_priv;
831 
832 	port_priv = usb_get_serial_port_data(tty->driver_data);
833 	return update_mctrl(port_priv, set, clear);
834 }
835 
836 static void qt2_break_ctl(struct tty_struct *tty, int break_state)
837 {
838 	struct usb_serial_port *port = tty->driver_data;
839 	struct qt2_port_private *port_priv;
840 	int status;
841 	u16 val;
842 
843 	port_priv = usb_get_serial_port_data(port);
844 
845 	val = (break_state == -1) ? 1 : 0;
846 
847 	status = qt2_control_msg(port->serial->dev, QT2_BREAK_CONTROL,
848 				 val, port_priv->device_port);
849 	if (status < 0)
850 		dev_warn(&port->dev,
851 			 "%s - failed to send control message: %i\n", __func__,
852 			 status);
853 }
854 
855 
856 
857 static void qt2_dtr_rts(struct usb_serial_port *port, int on)
858 {
859 	struct usb_device *dev = port->serial->dev;
860 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
861 
862 	/* Disable flow control */
863 	if (!on) {
864 		if (qt2_setregister(dev, port_priv->device_port,
865 					   UART_MCR, 0) < 0)
866 			dev_warn(&port->dev, "error from flowcontrol urb\n");
867 	}
868 	/* drop RTS and DTR */
869 	if (on)
870 		update_mctrl(port_priv, TIOCM_DTR | TIOCM_RTS, 0);
871 	else
872 		update_mctrl(port_priv, 0, TIOCM_DTR | TIOCM_RTS);
873 }
874 
875 static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch)
876 {
877 	struct qt2_port_private *port_priv;
878 	u8 newMSR = (u8) *ch;
879 	unsigned long flags;
880 
881 	port_priv = usb_get_serial_port_data(port);
882 
883 	spin_lock_irqsave(&port_priv->lock, flags);
884 	port_priv->shadowMSR = newMSR;
885 	spin_unlock_irqrestore(&port_priv->lock, flags);
886 
887 	if (newMSR & UART_MSR_ANY_DELTA) {
888 		/* update input line counters */
889 		if (newMSR & UART_MSR_DCTS)
890 			port->icount.cts++;
891 		if (newMSR & UART_MSR_DDSR)
892 			port->icount.dsr++;
893 		if (newMSR & UART_MSR_DDCD)
894 			port->icount.dcd++;
895 		if (newMSR & UART_MSR_TERI)
896 			port->icount.rng++;
897 
898 		wake_up_interruptible(&port->port.delta_msr_wait);
899 	}
900 }
901 
902 static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch)
903 {
904 	struct qt2_port_private *port_priv;
905 	struct async_icount *icount;
906 	unsigned long flags;
907 	u8 newLSR = (u8) *ch;
908 
909 	port_priv = usb_get_serial_port_data(port);
910 
911 	if (newLSR & UART_LSR_BI)
912 		newLSR &= (u8) (UART_LSR_OE | UART_LSR_BI);
913 
914 	spin_lock_irqsave(&port_priv->lock, flags);
915 	port_priv->shadowLSR = newLSR;
916 	spin_unlock_irqrestore(&port_priv->lock, flags);
917 
918 	icount = &port->icount;
919 
920 	if (newLSR & UART_LSR_BRK_ERROR_BITS) {
921 
922 		if (newLSR & UART_LSR_BI)
923 			icount->brk++;
924 
925 		if (newLSR & UART_LSR_OE)
926 			icount->overrun++;
927 
928 		if (newLSR & UART_LSR_PE)
929 			icount->parity++;
930 
931 		if (newLSR & UART_LSR_FE)
932 			icount->frame++;
933 	}
934 
935 }
936 
937 static int qt2_write_room(struct tty_struct *tty)
938 {
939 	struct usb_serial_port *port = tty->driver_data;
940 	struct qt2_port_private *port_priv;
941 	unsigned long flags = 0;
942 	int r;
943 
944 	port_priv = usb_get_serial_port_data(port);
945 
946 	spin_lock_irqsave(&port_priv->urb_lock, flags);
947 
948 	if (port_priv->urb_in_use)
949 		r = 0;
950 	else
951 		r = QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE;
952 
953 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
954 
955 	return r;
956 }
957 
958 static int qt2_write(struct tty_struct *tty,
959 		     struct usb_serial_port *port,
960 		     const unsigned char *buf, int count)
961 {
962 	struct qt2_port_private *port_priv;
963 	struct urb *write_urb;
964 	unsigned char *data;
965 	unsigned long flags;
966 	int status;
967 	int bytes_out = 0;
968 
969 	port_priv = usb_get_serial_port_data(port);
970 
971 	if (port_priv->write_urb == NULL) {
972 		dev_err(&port->dev, "%s - no output urb\n", __func__);
973 		return 0;
974 	}
975 	write_urb = port_priv->write_urb;
976 
977 	count = min(count, QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE);
978 
979 	data = write_urb->transfer_buffer;
980 	spin_lock_irqsave(&port_priv->urb_lock, flags);
981 	if (port_priv->urb_in_use == true) {
982 		dev_err(&port->dev, "qt2_write - urb is in use\n");
983 		goto write_out;
984 	}
985 
986 	*data++ = QT2_CONTROL_BYTE;
987 	*data++ = QT2_CONTROL_BYTE;
988 	*data++ = port_priv->device_port;
989 	put_unaligned_le16(count, data);
990 	data += 2;
991 	memcpy(data, buf, count);
992 
993 	write_urb->transfer_buffer_length = count + QT2_WRITE_CONTROL_SIZE;
994 
995 	status = usb_submit_urb(write_urb, GFP_ATOMIC);
996 	if (status == 0) {
997 		port_priv->urb_in_use = true;
998 		bytes_out += count;
999 	}
1000 
1001 write_out:
1002 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
1003 	return bytes_out;
1004 }
1005 
1006 
1007 static struct usb_serial_driver qt2_device = {
1008 	.driver = {
1009 		.owner = THIS_MODULE,
1010 		.name = "quatech-serial",
1011 	},
1012 	.description	     = DRIVER_DESC,
1013 	.id_table	     = id_table,
1014 	.open		     = qt2_open,
1015 	.close		     = qt2_close,
1016 	.write               = qt2_write,
1017 	.write_room          = qt2_write_room,
1018 	.calc_num_ports      = qt2_calc_num_ports,
1019 	.attach              = qt2_attach,
1020 	.release             = qt2_release,
1021 	.disconnect          = qt2_disconnect,
1022 	.port_probe          = qt2_port_probe,
1023 	.port_remove         = qt2_port_remove,
1024 	.dtr_rts             = qt2_dtr_rts,
1025 	.break_ctl           = qt2_break_ctl,
1026 	.tiocmget            = qt2_tiocmget,
1027 	.tiocmset            = qt2_tiocmset,
1028 	.tiocmiwait          = usb_serial_generic_tiocmiwait,
1029 	.get_icount	     = usb_serial_generic_get_icount,
1030 	.ioctl               = qt2_ioctl,
1031 	.set_termios         = qt2_set_termios,
1032 };
1033 
1034 static struct usb_serial_driver *const serial_drivers[] = {
1035 	&qt2_device, NULL
1036 };
1037 
1038 module_usb_serial_driver(serial_drivers, id_table);
1039 
1040 MODULE_DESCRIPTION(DRIVER_DESC);
1041 MODULE_LICENSE("GPL");
1042