xref: /openbmc/linux/drivers/usb/serial/quatech2.c (revision d3964221)
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/slab.h>
19 #include <linux/tty.h>
20 #include <linux/tty_driver.h>
21 #include <linux/tty_flip.h>
22 #include <linux/module.h>
23 #include <linux/serial.h>
24 #include <linux/usb.h>
25 #include <linux/usb/serial.h>
26 #include <linux/serial_reg.h>
27 #include <linux/uaccess.h>
28 
29 /* default urb timeout for usb operations */
30 #define QT2_USB_TIMEOUT USB_CTRL_SET_TIMEOUT
31 
32 #define QT_OPEN_CLOSE_CHANNEL       0xca
33 #define QT_SET_GET_DEVICE           0xc2
34 #define QT_SET_GET_REGISTER         0xc0
35 #define QT_GET_SET_PREBUF_TRIG_LVL  0xcc
36 #define QT_SET_ATF                  0xcd
37 #define QT_TRANSFER_IN              0xc0
38 #define QT_HW_FLOW_CONTROL_MASK     0xc5
39 #define QT_SW_FLOW_CONTROL_MASK     0xc6
40 #define QT2_BREAK_CONTROL	    0xc8
41 #define QT2_GET_SET_UART            0xc1
42 #define QT2_FLUSH_DEVICE	    0xc4
43 #define QT2_GET_SET_QMCR            0xe1
44 #define QT2_QMCR_RS232              0x40
45 #define QT2_QMCR_RS422              0x10
46 
47 #define  SERIAL_CRTSCTS ((UART_MCR_RTS << 8) | UART_MSR_CTS)
48 
49 #define  SERIAL_EVEN_PARITY         (UART_LCR_PARITY | UART_LCR_EPAR)
50 
51 /* status bytes for the device */
52 #define QT2_CONTROL_BYTE    0x1b
53 #define QT2_LINE_STATUS     0x00  /* following 1 byte is line status */
54 #define QT2_MODEM_STATUS    0x01  /* following 1 byte is modem status */
55 #define QT2_XMIT_HOLD       0x02  /* following 2 bytes are ?? */
56 #define QT2_CHANGE_PORT     0x03  /* following 1 byte is port to change to */
57 #define QT2_REC_FLUSH       0x04  /* no following info */
58 #define QT2_XMIT_FLUSH      0x05  /* no following info */
59 #define QT2_CONTROL_ESCAPE  0xff  /* pass through previous 2 control bytes */
60 
61 #define  MAX_BAUD_RATE              921600
62 #define  DEFAULT_BAUD_RATE          9600
63 
64 #define QT2_READ_BUFFER_SIZE    512  /* size of read buffer */
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;
116 };
117 
118 struct qt2_port_private {
119 	u8   device_port;
120 
121 	spinlock_t urb_lock;
122 	bool       urb_in_use;
123 	struct urb *write_urb;
124 	char       *write_buffer;
125 
126 	spinlock_t  lock;
127 	u8          shadowLSR;
128 	u8          shadowMSR;
129 
130 	struct usb_serial_port *port;
131 };
132 
133 static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch);
134 static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch);
135 static void qt2_write_bulk_callback(struct urb *urb);
136 static void qt2_read_bulk_callback(struct urb *urb);
137 
138 static void qt2_release(struct usb_serial *serial)
139 {
140 	struct qt2_serial_private *serial_priv;
141 
142 	serial_priv = usb_get_serial_data(serial);
143 
144 	usb_kill_urb(serial_priv->read_urb);
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_getregister(struct usb_device *dev,
192 				  u8 uart,
193 				  u8 reg,
194 				  u8 *data)
195 {
196 	int ret;
197 
198 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
199 			      QT_SET_GET_REGISTER, 0xc0, reg,
200 			      uart, data, sizeof(*data), QT2_USB_TIMEOUT);
201 	if (ret < sizeof(*data)) {
202 		if (ret >= 0)
203 			ret = -EIO;
204 	}
205 
206 	return ret;
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 					struct usb_serial_endpoints *epds)
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 = port->port_number;
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 < 2) {
377 		dev_err(&port->dev, "%s - open port failed %i\n", __func__,
378 			status);
379 		if (status >= 0)
380 			status = -EIO;
381 		kfree(data);
382 		return status;
383 	}
384 
385 	spin_lock_irqsave(&port_priv->lock, flags);
386 	port_priv->shadowLSR = data[0];
387 	port_priv->shadowMSR = data[1];
388 	spin_unlock_irqrestore(&port_priv->lock, flags);
389 
390 	kfree(data);
391 
392 	/* set to default speed and 8bit word size */
393 	status = qt2_set_port_config(serial->dev, device_port,
394 				     DEFAULT_BAUD_RATE, UART_LCR_WLEN8);
395 	if (status < 0) {
396 		dev_err(&port->dev, "%s - initial setup failed (%i)\n",
397 			__func__, device_port);
398 		return status;
399 	}
400 
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 	int i;
415 
416 	serial = port->serial;
417 	port_priv = usb_get_serial_port_data(port);
418 
419 	usb_kill_urb(port_priv->write_urb);
420 
421 	/* flush the port transmit buffer */
422 	i = usb_control_msg(serial->dev,
423 			    usb_rcvctrlpipe(serial->dev, 0),
424 			    QT2_FLUSH_DEVICE, 0x40, 1,
425 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
426 
427 	if (i < 0)
428 		dev_err(&port->dev, "%s - transmit buffer flush failed: %i\n",
429 			__func__, i);
430 
431 	/* flush the port receive buffer */
432 	i = usb_control_msg(serial->dev,
433 			    usb_rcvctrlpipe(serial->dev, 0),
434 			    QT2_FLUSH_DEVICE, 0x40, 0,
435 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
436 
437 	if (i < 0)
438 		dev_err(&port->dev, "%s - receive buffer flush failed: %i\n",
439 			__func__, i);
440 
441 	/* close the port */
442 	i = usb_control_msg(serial->dev,
443 			    usb_sndctrlpipe(serial->dev, 0),
444 			    QT_OPEN_CLOSE_CHANNEL,
445 			    0x40, 0,
446 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
447 
448 	if (i < 0)
449 		dev_err(&port->dev, "%s - close port failed %i\n",
450 			__func__, i);
451 }
452 
453 static void qt2_disconnect(struct usb_serial *serial)
454 {
455 	struct qt2_serial_private *serial_priv = usb_get_serial_data(serial);
456 
457 	usb_kill_urb(serial_priv->read_urb);
458 }
459 
460 static int get_serial_info(struct usb_serial_port *port,
461 			   struct serial_struct __user *retinfo)
462 {
463 	struct serial_struct tmp;
464 
465 	memset(&tmp, 0, sizeof(tmp));
466 	tmp.line		= port->minor;
467 	tmp.port		= 0;
468 	tmp.irq			= 0;
469 	tmp.xmit_fifo_size	= port->bulk_out_size;
470 	tmp.baud_base		= 9600;
471 	tmp.close_delay		= 5*HZ;
472 	tmp.closing_wait	= 30*HZ;
473 
474 	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
475 		return -EFAULT;
476 	return 0;
477 }
478 
479 static int qt2_ioctl(struct tty_struct *tty,
480 		     unsigned int cmd, unsigned long arg)
481 {
482 	struct usb_serial_port *port = tty->driver_data;
483 
484 	switch (cmd) {
485 	case TIOCGSERIAL:
486 		return get_serial_info(port,
487 				       (struct serial_struct __user *)arg);
488 	default:
489 		break;
490 	}
491 
492 	return -ENOIOCTLCMD;
493 }
494 
495 static void qt2_process_status(struct usb_serial_port *port, unsigned char *ch)
496 {
497 	switch (*ch) {
498 	case QT2_LINE_STATUS:
499 		qt2_update_lsr(port, ch + 1);
500 		break;
501 	case QT2_MODEM_STATUS:
502 		qt2_update_msr(port, ch + 1);
503 		break;
504 	}
505 }
506 
507 /* not needed, kept to document functionality */
508 static void qt2_process_xmit_empty(struct usb_serial_port *port,
509 				   unsigned char *ch)
510 {
511 	int bytes_written;
512 
513 	bytes_written = (int)(*ch) + (int)(*(ch + 1) << 4);
514 }
515 
516 /* not needed, kept to document functionality */
517 static void qt2_process_flush(struct usb_serial_port *port, unsigned char *ch)
518 {
519 	return;
520 }
521 
522 static void qt2_process_read_urb(struct urb *urb)
523 {
524 	struct usb_serial *serial;
525 	struct qt2_serial_private *serial_priv;
526 	struct usb_serial_port *port;
527 	struct qt2_port_private *port_priv;
528 	bool escapeflag;
529 	unsigned char *ch;
530 	int i;
531 	unsigned char newport;
532 	int len = urb->actual_length;
533 
534 	if (!len)
535 		return;
536 
537 	ch = urb->transfer_buffer;
538 	serial = urb->context;
539 	serial_priv = usb_get_serial_data(serial);
540 	port = serial->port[serial_priv->current_port];
541 	port_priv = usb_get_serial_port_data(port);
542 
543 	for (i = 0; i < urb->actual_length; i++) {
544 		ch = (unsigned char *)urb->transfer_buffer + i;
545 		if ((i <= (len - 3)) &&
546 		    (*ch == QT2_CONTROL_BYTE) &&
547 		    (*(ch + 1) == QT2_CONTROL_BYTE)) {
548 			escapeflag = false;
549 			switch (*(ch + 2)) {
550 			case QT2_LINE_STATUS:
551 			case QT2_MODEM_STATUS:
552 				if (i > (len - 4)) {
553 					dev_warn(&port->dev,
554 						 "%s - status message too short\n",
555 						__func__);
556 					break;
557 				}
558 				qt2_process_status(port, ch + 2);
559 				i += 3;
560 				escapeflag = true;
561 				break;
562 			case QT2_XMIT_HOLD:
563 				if (i > (len - 5)) {
564 					dev_warn(&port->dev,
565 						 "%s - xmit_empty message too short\n",
566 						 __func__);
567 					break;
568 				}
569 				qt2_process_xmit_empty(port, ch + 3);
570 				i += 4;
571 				escapeflag = true;
572 				break;
573 			case QT2_CHANGE_PORT:
574 				if (i > (len - 4)) {
575 					dev_warn(&port->dev,
576 						 "%s - change_port message too short\n",
577 						 __func__);
578 					break;
579 				}
580 				tty_flip_buffer_push(&port->port);
581 
582 				newport = *(ch + 3);
583 
584 				if (newport > serial->num_ports) {
585 					dev_err(&port->dev,
586 						"%s - port change to invalid port: %i\n",
587 						__func__, newport);
588 					break;
589 				}
590 
591 				serial_priv->current_port = newport;
592 				port = serial->port[serial_priv->current_port];
593 				port_priv = usb_get_serial_port_data(port);
594 				i += 3;
595 				escapeflag = true;
596 				break;
597 			case QT2_REC_FLUSH:
598 			case QT2_XMIT_FLUSH:
599 				qt2_process_flush(port, ch + 2);
600 				i += 2;
601 				escapeflag = true;
602 				break;
603 			case QT2_CONTROL_ESCAPE:
604 				tty_insert_flip_string(&port->port, ch, 2);
605 				i += 2;
606 				escapeflag = true;
607 				break;
608 			default:
609 				dev_warn(&port->dev,
610 					 "%s - unsupported command %i\n",
611 					 __func__, *(ch + 2));
612 				break;
613 			}
614 			if (escapeflag)
615 				continue;
616 		}
617 
618 		tty_insert_flip_char(&port->port, *ch, TTY_NORMAL);
619 	}
620 
621 	tty_flip_buffer_push(&port->port);
622 }
623 
624 static void qt2_write_bulk_callback(struct urb *urb)
625 {
626 	struct usb_serial_port *port;
627 	struct qt2_port_private *port_priv;
628 
629 	port = urb->context;
630 	port_priv = usb_get_serial_port_data(port);
631 
632 	spin_lock(&port_priv->urb_lock);
633 
634 	port_priv->urb_in_use = false;
635 	usb_serial_port_softint(port);
636 
637 	spin_unlock(&port_priv->urb_lock);
638 
639 }
640 
641 static void qt2_read_bulk_callback(struct urb *urb)
642 {
643 	struct usb_serial *serial = urb->context;
644 	int status;
645 
646 	if (urb->status) {
647 		dev_warn(&serial->dev->dev,
648 			 "%s - non-zero urb status: %i\n", __func__,
649 			 urb->status);
650 		return;
651 	}
652 
653 	qt2_process_read_urb(urb);
654 
655 	status = usb_submit_urb(urb, GFP_ATOMIC);
656 	if (status != 0)
657 		dev_err(&serial->dev->dev,
658 			"%s - resubmit read urb failed: %i\n",
659 			__func__, status);
660 }
661 
662 static int qt2_setup_urbs(struct usb_serial *serial)
663 {
664 	struct usb_serial_port *port0;
665 	struct qt2_serial_private *serial_priv;
666 	int status;
667 
668 	port0 = serial->port[0];
669 
670 	serial_priv = usb_get_serial_data(serial);
671 	serial_priv->read_urb = usb_alloc_urb(0, GFP_KERNEL);
672 	if (!serial_priv->read_urb)
673 		return -ENOMEM;
674 
675 	usb_fill_bulk_urb(serial_priv->read_urb, serial->dev,
676 			  usb_rcvbulkpipe(serial->dev,
677 					  port0->bulk_in_endpointAddress),
678 			  serial_priv->read_buffer,
679 			  QT2_READ_BUFFER_SIZE,
680 			  qt2_read_bulk_callback, serial);
681 
682 	status = usb_submit_urb(serial_priv->read_urb, GFP_KERNEL);
683 	if (status != 0) {
684 		dev_err(&serial->dev->dev,
685 			"%s - submit read urb failed %i\n", __func__, status);
686 		usb_free_urb(serial_priv->read_urb);
687 		return status;
688 	}
689 
690 	return 0;
691 }
692 
693 static int qt2_attach(struct usb_serial *serial)
694 {
695 	struct qt2_serial_private *serial_priv;
696 	int status;
697 
698 	/* power on unit */
699 	status = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
700 				 0xc2, 0x40, 0x8000, 0, NULL, 0,
701 				 QT2_USB_TIMEOUT);
702 	if (status < 0) {
703 		dev_err(&serial->dev->dev,
704 			"%s - failed to power on unit: %i\n", __func__, status);
705 		return status;
706 	}
707 
708 	serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL);
709 	if (!serial_priv)
710 		return -ENOMEM;
711 
712 	serial_priv->read_buffer = kmalloc(QT2_READ_BUFFER_SIZE, GFP_KERNEL);
713 	if (!serial_priv->read_buffer) {
714 		status = -ENOMEM;
715 		goto err_buf;
716 	}
717 
718 	usb_set_serial_data(serial, serial_priv);
719 
720 	status = qt2_setup_urbs(serial);
721 	if (status != 0)
722 		goto attach_failed;
723 
724 	return 0;
725 
726 attach_failed:
727 	kfree(serial_priv->read_buffer);
728 err_buf:
729 	kfree(serial_priv);
730 	return status;
731 }
732 
733 static int qt2_port_probe(struct usb_serial_port *port)
734 {
735 	struct usb_serial *serial = port->serial;
736 	struct qt2_port_private *port_priv;
737 	u8 bEndpointAddress;
738 
739 	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
740 	if (!port_priv)
741 		return -ENOMEM;
742 
743 	spin_lock_init(&port_priv->lock);
744 	spin_lock_init(&port_priv->urb_lock);
745 	port_priv->port = port;
746 
747 	port_priv->write_buffer = kmalloc(QT2_WRITE_BUFFER_SIZE, GFP_KERNEL);
748 	if (!port_priv->write_buffer)
749 		goto err_buf;
750 
751 	port_priv->write_urb = usb_alloc_urb(0, GFP_KERNEL);
752 	if (!port_priv->write_urb)
753 		goto err_urb;
754 
755 	bEndpointAddress = serial->port[0]->bulk_out_endpointAddress;
756 	usb_fill_bulk_urb(port_priv->write_urb, serial->dev,
757 				usb_sndbulkpipe(serial->dev, bEndpointAddress),
758 				port_priv->write_buffer,
759 				QT2_WRITE_BUFFER_SIZE,
760 				qt2_write_bulk_callback, port);
761 
762 	usb_set_serial_port_data(port, port_priv);
763 
764 	return 0;
765 err_urb:
766 	kfree(port_priv->write_buffer);
767 err_buf:
768 	kfree(port_priv);
769 	return -ENOMEM;
770 }
771 
772 static int qt2_port_remove(struct usb_serial_port *port)
773 {
774 	struct qt2_port_private *port_priv;
775 
776 	port_priv = usb_get_serial_port_data(port);
777 	usb_free_urb(port_priv->write_urb);
778 	kfree(port_priv->write_buffer);
779 	kfree(port_priv);
780 
781 	return 0;
782 }
783 
784 static int qt2_tiocmget(struct tty_struct *tty)
785 {
786 	struct usb_serial_port *port = tty->driver_data;
787 	struct usb_device *dev = port->serial->dev;
788 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
789 	u8 *d;
790 	int r;
791 
792 	d = kzalloc(2, GFP_KERNEL);
793 	if (!d)
794 		return -ENOMEM;
795 
796 	r = qt2_getregister(dev, port_priv->device_port, UART_MCR, d);
797 	if (r < 0)
798 		goto mget_out;
799 
800 	r = qt2_getregister(dev, port_priv->device_port, UART_MSR, d + 1);
801 	if (r < 0)
802 		goto mget_out;
803 
804 	r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) |
805 	    (d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) |
806 	    (d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) |
807 	    (d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) |
808 	    (d[1] & UART_MSR_RI ? TIOCM_RI : 0) |
809 	    (d[1] & UART_MSR_DSR ? TIOCM_DSR : 0);
810 
811 mget_out:
812 	kfree(d);
813 	return r;
814 }
815 
816 static int qt2_tiocmset(struct tty_struct *tty,
817 			unsigned int set, unsigned int clear)
818 {
819 	struct qt2_port_private *port_priv;
820 
821 	port_priv = usb_get_serial_port_data(tty->driver_data);
822 	return update_mctrl(port_priv, set, clear);
823 }
824 
825 static void qt2_break_ctl(struct tty_struct *tty, int break_state)
826 {
827 	struct usb_serial_port *port = tty->driver_data;
828 	struct qt2_port_private *port_priv;
829 	int status;
830 	u16 val;
831 
832 	port_priv = usb_get_serial_port_data(port);
833 
834 	val = (break_state == -1) ? 1 : 0;
835 
836 	status = qt2_control_msg(port->serial->dev, QT2_BREAK_CONTROL,
837 				 val, port_priv->device_port);
838 	if (status < 0)
839 		dev_warn(&port->dev,
840 			 "%s - failed to send control message: %i\n", __func__,
841 			 status);
842 }
843 
844 
845 
846 static void qt2_dtr_rts(struct usb_serial_port *port, int on)
847 {
848 	struct usb_device *dev = port->serial->dev;
849 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
850 
851 	/* Disable flow control */
852 	if (!on) {
853 		if (qt2_setregister(dev, port_priv->device_port,
854 					   UART_MCR, 0) < 0)
855 			dev_warn(&port->dev, "error from flowcontrol urb\n");
856 	}
857 	/* drop RTS and DTR */
858 	if (on)
859 		update_mctrl(port_priv, TIOCM_DTR | TIOCM_RTS, 0);
860 	else
861 		update_mctrl(port_priv, 0, TIOCM_DTR | TIOCM_RTS);
862 }
863 
864 static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch)
865 {
866 	struct qt2_port_private *port_priv;
867 	u8 newMSR = (u8) *ch;
868 	unsigned long flags;
869 
870 	port_priv = usb_get_serial_port_data(port);
871 
872 	spin_lock_irqsave(&port_priv->lock, flags);
873 	port_priv->shadowMSR = newMSR;
874 	spin_unlock_irqrestore(&port_priv->lock, flags);
875 
876 	if (newMSR & UART_MSR_ANY_DELTA) {
877 		/* update input line counters */
878 		if (newMSR & UART_MSR_DCTS)
879 			port->icount.cts++;
880 		if (newMSR & UART_MSR_DDSR)
881 			port->icount.dsr++;
882 		if (newMSR & UART_MSR_DDCD)
883 			port->icount.dcd++;
884 		if (newMSR & UART_MSR_TERI)
885 			port->icount.rng++;
886 
887 		wake_up_interruptible(&port->port.delta_msr_wait);
888 	}
889 }
890 
891 static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch)
892 {
893 	struct qt2_port_private *port_priv;
894 	struct async_icount *icount;
895 	unsigned long flags;
896 	u8 newLSR = (u8) *ch;
897 
898 	port_priv = usb_get_serial_port_data(port);
899 
900 	if (newLSR & UART_LSR_BI)
901 		newLSR &= (u8) (UART_LSR_OE | UART_LSR_BI);
902 
903 	spin_lock_irqsave(&port_priv->lock, flags);
904 	port_priv->shadowLSR = newLSR;
905 	spin_unlock_irqrestore(&port_priv->lock, flags);
906 
907 	icount = &port->icount;
908 
909 	if (newLSR & UART_LSR_BRK_ERROR_BITS) {
910 
911 		if (newLSR & UART_LSR_BI)
912 			icount->brk++;
913 
914 		if (newLSR & UART_LSR_OE)
915 			icount->overrun++;
916 
917 		if (newLSR & UART_LSR_PE)
918 			icount->parity++;
919 
920 		if (newLSR & UART_LSR_FE)
921 			icount->frame++;
922 	}
923 
924 }
925 
926 static int qt2_write_room(struct tty_struct *tty)
927 {
928 	struct usb_serial_port *port = tty->driver_data;
929 	struct qt2_port_private *port_priv;
930 	unsigned long flags = 0;
931 	int r;
932 
933 	port_priv = usb_get_serial_port_data(port);
934 
935 	spin_lock_irqsave(&port_priv->urb_lock, flags);
936 
937 	if (port_priv->urb_in_use)
938 		r = 0;
939 	else
940 		r = QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE;
941 
942 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
943 
944 	return r;
945 }
946 
947 static int qt2_write(struct tty_struct *tty,
948 		     struct usb_serial_port *port,
949 		     const unsigned char *buf, int count)
950 {
951 	struct qt2_port_private *port_priv;
952 	struct urb *write_urb;
953 	unsigned char *data;
954 	unsigned long flags;
955 	int status;
956 	int bytes_out = 0;
957 
958 	port_priv = usb_get_serial_port_data(port);
959 
960 	if (port_priv->write_urb == NULL) {
961 		dev_err(&port->dev, "%s - no output urb\n", __func__);
962 		return 0;
963 	}
964 	write_urb = port_priv->write_urb;
965 
966 	count = min(count, QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE);
967 
968 	data = write_urb->transfer_buffer;
969 	spin_lock_irqsave(&port_priv->urb_lock, flags);
970 	if (port_priv->urb_in_use) {
971 		dev_err(&port->dev, "qt2_write - urb is in use\n");
972 		goto write_out;
973 	}
974 
975 	*data++ = QT2_CONTROL_BYTE;
976 	*data++ = QT2_CONTROL_BYTE;
977 	*data++ = port_priv->device_port;
978 	put_unaligned_le16(count, data);
979 	data += 2;
980 	memcpy(data, buf, count);
981 
982 	write_urb->transfer_buffer_length = count + QT2_WRITE_CONTROL_SIZE;
983 
984 	status = usb_submit_urb(write_urb, GFP_ATOMIC);
985 	if (status == 0) {
986 		port_priv->urb_in_use = true;
987 		bytes_out += count;
988 	}
989 
990 write_out:
991 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
992 	return bytes_out;
993 }
994 
995 
996 static struct usb_serial_driver qt2_device = {
997 	.driver = {
998 		.owner = THIS_MODULE,
999 		.name = "quatech-serial",
1000 	},
1001 	.description	     = DRIVER_DESC,
1002 	.id_table	     = id_table,
1003 	.open		     = qt2_open,
1004 	.close		     = qt2_close,
1005 	.write               = qt2_write,
1006 	.write_room          = qt2_write_room,
1007 	.calc_num_ports      = qt2_calc_num_ports,
1008 	.attach              = qt2_attach,
1009 	.release             = qt2_release,
1010 	.disconnect          = qt2_disconnect,
1011 	.port_probe          = qt2_port_probe,
1012 	.port_remove         = qt2_port_remove,
1013 	.dtr_rts             = qt2_dtr_rts,
1014 	.break_ctl           = qt2_break_ctl,
1015 	.tiocmget            = qt2_tiocmget,
1016 	.tiocmset            = qt2_tiocmset,
1017 	.tiocmiwait          = usb_serial_generic_tiocmiwait,
1018 	.get_icount	     = usb_serial_generic_get_icount,
1019 	.ioctl               = qt2_ioctl,
1020 	.set_termios         = qt2_set_termios,
1021 };
1022 
1023 static struct usb_serial_driver *const serial_drivers[] = {
1024 	&qt2_device, NULL
1025 };
1026 
1027 module_usb_serial_driver(serial_drivers, id_table);
1028 
1029 MODULE_DESCRIPTION(DRIVER_DESC);
1030 MODULE_LICENSE("GPL");
1031