xref: /linux/drivers/usb/serial/oti6858.c (revision b889fcf63cb62e7fdb7816565e28f44dbe4a76a5)
1 /*
2  * Ours Technology Inc. OTi-6858 USB to serial adapter driver.
3  *
4  * Copyleft  (C) 2007 Kees Lemmens (adapted for kernel 2.6.20)
5  * Copyright (C) 2006 Tomasz Michal Lukaszewski (FIXME: add e-mail)
6  * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
7  * Copyright (C) 2003 IBM Corp.
8  *
9  * Many thanks to the authors of pl2303 driver: all functions in this file
10  * are heavily based on pl2303 code, buffering code is a 1-to-1 copy.
11  *
12  * Warning! You use this driver on your own risk! The only official
13  * description of this device I have is datasheet from manufacturer,
14  * and it doesn't contain almost any information needed to write a driver.
15  * Almost all knowlegde used while writing this driver was gathered by:
16  *  - analyzing traffic between device and the M$ Windows 2000 driver,
17  *  - trying different bit combinations and checking pin states
18  *    with a voltmeter,
19  *  - receiving malformed frames and producing buffer overflows
20  *    to learn how errors are reported,
21  * So, THIS CODE CAN DESTROY OTi-6858 AND ANY OTHER DEVICES, THAT ARE
22  * CONNECTED TO IT!
23  *
24  * This program is free software; you can redistribute it and/or modify
25  * it under the terms of the GNU General Public License as published by
26  * the Free Software Foundation; either version 2 of the License.
27  *
28  * See Documentation/usb/usb-serial.txt for more information on using this
29  * driver
30  *
31  * TODO:
32  *  - implement correct flushing for ioctls and oti6858_close()
33  *  - check how errors (rx overflow, parity error, framing error) are reported
34  *  - implement oti6858_break_ctl()
35  *  - implement more ioctls
36  *  - test/implement flow control
37  *  - allow setting custom baud rates
38  */
39 
40 #include <linux/kernel.h>
41 #include <linux/errno.h>
42 #include <linux/init.h>
43 #include <linux/slab.h>
44 #include <linux/tty.h>
45 #include <linux/tty_driver.h>
46 #include <linux/tty_flip.h>
47 #include <linux/serial.h>
48 #include <linux/module.h>
49 #include <linux/moduleparam.h>
50 #include <linux/spinlock.h>
51 #include <linux/usb.h>
52 #include <linux/usb/serial.h>
53 #include <linux/uaccess.h>
54 #include <linux/kfifo.h>
55 #include "oti6858.h"
56 
57 #define OTI6858_DESCRIPTION \
58 	"Ours Technology Inc. OTi-6858 USB to serial adapter driver"
59 #define OTI6858_AUTHOR "Tomasz Michal Lukaszewski <FIXME@FIXME>"
60 
61 static const struct usb_device_id id_table[] = {
62 	{ USB_DEVICE(OTI6858_VENDOR_ID, OTI6858_PRODUCT_ID) },
63 	{ }
64 };
65 
66 MODULE_DEVICE_TABLE(usb, id_table);
67 
68 /* requests */
69 #define	OTI6858_REQ_GET_STATUS		(USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
70 #define	OTI6858_REQ_T_GET_STATUS	0x01
71 
72 #define	OTI6858_REQ_SET_LINE		(USB_DIR_OUT | USB_TYPE_VENDOR | 0x00)
73 #define	OTI6858_REQ_T_SET_LINE		0x00
74 
75 #define	OTI6858_REQ_CHECK_TXBUFF	(USB_DIR_IN | USB_TYPE_VENDOR | 0x01)
76 #define	OTI6858_REQ_T_CHECK_TXBUFF	0x00
77 
78 /* format of the control packet */
79 struct oti6858_control_pkt {
80 	__le16	divisor;	/* baud rate = 96000000 / (16 * divisor), LE */
81 #define OTI6858_MAX_BAUD_RATE	3000000
82 	u8	frame_fmt;
83 #define FMT_STOP_BITS_MASK	0xc0
84 #define FMT_STOP_BITS_1		0x00
85 #define FMT_STOP_BITS_2		0x40	/* 1.5 stop bits if FMT_DATA_BITS_5 */
86 #define FMT_PARITY_MASK		0x38
87 #define FMT_PARITY_NONE		0x00
88 #define FMT_PARITY_ODD		0x08
89 #define FMT_PARITY_EVEN		0x18
90 #define FMT_PARITY_MARK		0x28
91 #define FMT_PARITY_SPACE	0x38
92 #define FMT_DATA_BITS_MASK	0x03
93 #define FMT_DATA_BITS_5		0x00
94 #define FMT_DATA_BITS_6		0x01
95 #define FMT_DATA_BITS_7		0x02
96 #define FMT_DATA_BITS_8		0x03
97 	u8	something;	/* always equals 0x43 */
98 	u8	control;	/* settings of flow control lines */
99 #define CONTROL_MASK		0x0c
100 #define CONTROL_DTR_HIGH	0x08
101 #define CONTROL_RTS_HIGH	0x04
102 	u8	tx_status;
103 #define	TX_BUFFER_EMPTIED	0x09
104 	u8	pin_state;
105 #define PIN_MASK		0x3f
106 #define PIN_RTS			0x20	/* output pin */
107 #define PIN_CTS			0x10	/* input pin, active low */
108 #define PIN_DSR			0x08	/* input pin, active low */
109 #define PIN_DTR			0x04	/* output pin */
110 #define PIN_RI			0x02	/* input pin, active low */
111 #define PIN_DCD			0x01	/* input pin, active low */
112 	u8	rx_bytes_avail;		/* number of bytes in rx buffer */;
113 };
114 
115 #define OTI6858_CTRL_PKT_SIZE	sizeof(struct oti6858_control_pkt)
116 #define OTI6858_CTRL_EQUALS_PENDING(a, priv) \
117 	(((a)->divisor == (priv)->pending_setup.divisor) \
118 	  && ((a)->control == (priv)->pending_setup.control) \
119 	  && ((a)->frame_fmt == (priv)->pending_setup.frame_fmt))
120 
121 /* function prototypes */
122 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port);
123 static void oti6858_close(struct usb_serial_port *port);
124 static void oti6858_set_termios(struct tty_struct *tty,
125 			struct usb_serial_port *port, struct ktermios *old);
126 static void oti6858_init_termios(struct tty_struct *tty);
127 static int oti6858_ioctl(struct tty_struct *tty,
128 			unsigned int cmd, unsigned long arg);
129 static void oti6858_read_int_callback(struct urb *urb);
130 static void oti6858_read_bulk_callback(struct urb *urb);
131 static void oti6858_write_bulk_callback(struct urb *urb);
132 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
133 			const unsigned char *buf, int count);
134 static int oti6858_write_room(struct tty_struct *tty);
135 static int oti6858_chars_in_buffer(struct tty_struct *tty);
136 static int oti6858_tiocmget(struct tty_struct *tty);
137 static int oti6858_tiocmset(struct tty_struct *tty,
138 				unsigned int set, unsigned int clear);
139 static int oti6858_port_probe(struct usb_serial_port *port);
140 static int oti6858_port_remove(struct usb_serial_port *port);
141 
142 /* device info */
143 static struct usb_serial_driver oti6858_device = {
144 	.driver = {
145 		.owner =	THIS_MODULE,
146 		.name =		"oti6858",
147 	},
148 	.id_table =		id_table,
149 	.num_ports =		1,
150 	.open =			oti6858_open,
151 	.close =		oti6858_close,
152 	.write =		oti6858_write,
153 	.ioctl =		oti6858_ioctl,
154 	.set_termios =		oti6858_set_termios,
155 	.init_termios = 	oti6858_init_termios,
156 	.tiocmget =		oti6858_tiocmget,
157 	.tiocmset =		oti6858_tiocmset,
158 	.read_bulk_callback =	oti6858_read_bulk_callback,
159 	.read_int_callback =	oti6858_read_int_callback,
160 	.write_bulk_callback =	oti6858_write_bulk_callback,
161 	.write_room =		oti6858_write_room,
162 	.chars_in_buffer =	oti6858_chars_in_buffer,
163 	.port_probe =		oti6858_port_probe,
164 	.port_remove =		oti6858_port_remove,
165 };
166 
167 static struct usb_serial_driver * const serial_drivers[] = {
168 	&oti6858_device, NULL
169 };
170 
171 struct oti6858_private {
172 	spinlock_t lock;
173 
174 	struct oti6858_control_pkt status;
175 
176 	struct {
177 		u8 read_urb_in_use;
178 		u8 write_urb_in_use;
179 	} flags;
180 	struct delayed_work delayed_write_work;
181 
182 	struct {
183 		__le16 divisor;
184 		u8 frame_fmt;
185 		u8 control;
186 	} pending_setup;
187 	u8 transient;
188 	u8 setup_done;
189 	struct delayed_work delayed_setup_work;
190 
191 	wait_queue_head_t intr_wait;
192 	struct usb_serial_port *port;   /* USB port with which associated */
193 };
194 
195 static void setup_line(struct work_struct *work)
196 {
197 	struct oti6858_private *priv = container_of(work,
198 			struct oti6858_private, delayed_setup_work.work);
199 	struct usb_serial_port *port = priv->port;
200 	struct oti6858_control_pkt *new_setup;
201 	unsigned long flags;
202 	int result;
203 
204 	new_setup = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
205 	if (new_setup == NULL) {
206 		dev_err(&port->dev, "%s(): out of memory!\n", __func__);
207 		/* we will try again */
208 		schedule_delayed_work(&priv->delayed_setup_work,
209 						msecs_to_jiffies(2));
210 		return;
211 	}
212 
213 	result = usb_control_msg(port->serial->dev,
214 				usb_rcvctrlpipe(port->serial->dev, 0),
215 				OTI6858_REQ_T_GET_STATUS,
216 				OTI6858_REQ_GET_STATUS,
217 				0, 0,
218 				new_setup, OTI6858_CTRL_PKT_SIZE,
219 				100);
220 
221 	if (result != OTI6858_CTRL_PKT_SIZE) {
222 		dev_err(&port->dev, "%s(): error reading status\n", __func__);
223 		kfree(new_setup);
224 		/* we will try again */
225 		schedule_delayed_work(&priv->delayed_setup_work,
226 							msecs_to_jiffies(2));
227 		return;
228 	}
229 
230 	spin_lock_irqsave(&priv->lock, flags);
231 	if (!OTI6858_CTRL_EQUALS_PENDING(new_setup, priv)) {
232 		new_setup->divisor = priv->pending_setup.divisor;
233 		new_setup->control = priv->pending_setup.control;
234 		new_setup->frame_fmt = priv->pending_setup.frame_fmt;
235 
236 		spin_unlock_irqrestore(&priv->lock, flags);
237 		result = usb_control_msg(port->serial->dev,
238 					usb_sndctrlpipe(port->serial->dev, 0),
239 					OTI6858_REQ_T_SET_LINE,
240 					OTI6858_REQ_SET_LINE,
241 					0, 0,
242 					new_setup, OTI6858_CTRL_PKT_SIZE,
243 					100);
244 	} else {
245 		spin_unlock_irqrestore(&priv->lock, flags);
246 		result = 0;
247 	}
248 	kfree(new_setup);
249 
250 	spin_lock_irqsave(&priv->lock, flags);
251 	if (result != OTI6858_CTRL_PKT_SIZE)
252 		priv->transient = 0;
253 	priv->setup_done = 1;
254 	spin_unlock_irqrestore(&priv->lock, flags);
255 
256 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
257 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
258 	if (result != 0) {
259 		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
260 			__func__, result);
261 	}
262 }
263 
264 static void send_data(struct work_struct *work)
265 {
266 	struct oti6858_private *priv = container_of(work,
267 			struct oti6858_private, delayed_write_work.work);
268 	struct usb_serial_port *port = priv->port;
269 	int count = 0, result;
270 	unsigned long flags;
271 	u8 *allow;
272 
273 	spin_lock_irqsave(&priv->lock, flags);
274 	if (priv->flags.write_urb_in_use) {
275 		spin_unlock_irqrestore(&priv->lock, flags);
276 		schedule_delayed_work(&priv->delayed_write_work,
277 						msecs_to_jiffies(2));
278 		return;
279 	}
280 	priv->flags.write_urb_in_use = 1;
281 	spin_unlock_irqrestore(&priv->lock, flags);
282 
283 	spin_lock_irqsave(&port->lock, flags);
284 	count = kfifo_len(&port->write_fifo);
285 	spin_unlock_irqrestore(&port->lock, flags);
286 
287 	if (count > port->bulk_out_size)
288 		count = port->bulk_out_size;
289 
290 	if (count != 0) {
291 		allow = kmalloc(1, GFP_KERNEL);
292 		if (!allow) {
293 			dev_err_console(port, "%s(): kmalloc failed\n",
294 					__func__);
295 			return;
296 		}
297 		result = usb_control_msg(port->serial->dev,
298 				usb_rcvctrlpipe(port->serial->dev, 0),
299 				OTI6858_REQ_T_CHECK_TXBUFF,
300 				OTI6858_REQ_CHECK_TXBUFF,
301 				count, 0, allow, 1, 100);
302 		if (result != 1 || *allow != 0)
303 			count = 0;
304 		kfree(allow);
305 	}
306 
307 	if (count == 0) {
308 		priv->flags.write_urb_in_use = 0;
309 
310 		dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
311 		result = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
312 		if (result != 0) {
313 			dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
314 				__func__, result);
315 		}
316 		return;
317 	}
318 
319 	count = kfifo_out_locked(&port->write_fifo,
320 					port->write_urb->transfer_buffer,
321 					count, &port->lock);
322 	port->write_urb->transfer_buffer_length = count;
323 	result = usb_submit_urb(port->write_urb, GFP_NOIO);
324 	if (result != 0) {
325 		dev_err_console(port, "%s(): usb_submit_urb() failed with error %d\n",
326 				__func__, result);
327 		priv->flags.write_urb_in_use = 0;
328 	}
329 
330 	usb_serial_port_softint(port);
331 }
332 
333 static int oti6858_port_probe(struct usb_serial_port *port)
334 {
335 	struct oti6858_private *priv;
336 
337 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
338 	if (!priv)
339 		return -ENOMEM;
340 
341 	spin_lock_init(&priv->lock);
342 	init_waitqueue_head(&priv->intr_wait);
343 	priv->port = port;
344 	INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
345 	INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);
346 
347 	usb_set_serial_port_data(port, priv);
348 
349 	return 0;
350 }
351 
352 static int oti6858_port_remove(struct usb_serial_port *port)
353 {
354 	struct oti6858_private *priv;
355 
356 	priv = usb_get_serial_port_data(port);
357 	kfree(priv);
358 
359 	return 0;
360 }
361 
362 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
363 			const unsigned char *buf, int count)
364 {
365 	if (!count)
366 		return count;
367 
368 	count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
369 
370 	return count;
371 }
372 
373 static int oti6858_write_room(struct tty_struct *tty)
374 {
375 	struct usb_serial_port *port = tty->driver_data;
376 	int room = 0;
377 	unsigned long flags;
378 
379 	spin_lock_irqsave(&port->lock, flags);
380 	room = kfifo_avail(&port->write_fifo);
381 	spin_unlock_irqrestore(&port->lock, flags);
382 
383 	return room;
384 }
385 
386 static int oti6858_chars_in_buffer(struct tty_struct *tty)
387 {
388 	struct usb_serial_port *port = tty->driver_data;
389 	int chars = 0;
390 	unsigned long flags;
391 
392 	spin_lock_irqsave(&port->lock, flags);
393 	chars = kfifo_len(&port->write_fifo);
394 	spin_unlock_irqrestore(&port->lock, flags);
395 
396 	return chars;
397 }
398 
399 static void oti6858_init_termios(struct tty_struct *tty)
400 {
401 	tty->termios = tty_std_termios;
402 	tty->termios.c_cflag = B38400 | CS8 | CREAD | HUPCL | CLOCAL;
403 	tty->termios.c_ispeed = 38400;
404 	tty->termios.c_ospeed = 38400;
405 }
406 
407 static void oti6858_set_termios(struct tty_struct *tty,
408 		struct usb_serial_port *port, struct ktermios *old_termios)
409 {
410 	struct oti6858_private *priv = usb_get_serial_port_data(port);
411 	unsigned long flags;
412 	unsigned int cflag;
413 	u8 frame_fmt, control;
414 	__le16 divisor;
415 	int br;
416 
417 	if (!tty)
418 		return;
419 
420 	cflag = tty->termios.c_cflag;
421 
422 	spin_lock_irqsave(&priv->lock, flags);
423 	divisor = priv->pending_setup.divisor;
424 	frame_fmt = priv->pending_setup.frame_fmt;
425 	control = priv->pending_setup.control;
426 	spin_unlock_irqrestore(&priv->lock, flags);
427 
428 	frame_fmt &= ~FMT_DATA_BITS_MASK;
429 	switch (cflag & CSIZE) {
430 	case CS5:
431 		frame_fmt |= FMT_DATA_BITS_5;
432 		break;
433 	case CS6:
434 		frame_fmt |= FMT_DATA_BITS_6;
435 		break;
436 	case CS7:
437 		frame_fmt |= FMT_DATA_BITS_7;
438 		break;
439 	default:
440 	case CS8:
441 		frame_fmt |= FMT_DATA_BITS_8;
442 		break;
443 	}
444 
445 	/* manufacturer claims that this device can work with baud rates
446 	 * up to 3 Mbps; I've tested it only on 115200 bps, so I can't
447 	 * guarantee that any other baud rate will work (especially
448 	 * the higher ones)
449 	 */
450 	br = tty_get_baud_rate(tty);
451 	if (br == 0) {
452 		divisor = 0;
453 	} else {
454 		int real_br;
455 		int new_divisor;
456 		br = min(br, OTI6858_MAX_BAUD_RATE);
457 
458 		new_divisor = (96000000 + 8 * br) / (16 * br);
459 		real_br = 96000000 / (16 * new_divisor);
460 		divisor = cpu_to_le16(new_divisor);
461 		tty_encode_baud_rate(tty, real_br, real_br);
462 	}
463 
464 	frame_fmt &= ~FMT_STOP_BITS_MASK;
465 	if ((cflag & CSTOPB) != 0)
466 		frame_fmt |= FMT_STOP_BITS_2;
467 	else
468 		frame_fmt |= FMT_STOP_BITS_1;
469 
470 	frame_fmt &= ~FMT_PARITY_MASK;
471 	if ((cflag & PARENB) != 0) {
472 		if ((cflag & PARODD) != 0)
473 			frame_fmt |= FMT_PARITY_ODD;
474 		else
475 			frame_fmt |= FMT_PARITY_EVEN;
476 	} else {
477 		frame_fmt |= FMT_PARITY_NONE;
478 	}
479 
480 	control &= ~CONTROL_MASK;
481 	if ((cflag & CRTSCTS) != 0)
482 		control |= (CONTROL_DTR_HIGH | CONTROL_RTS_HIGH);
483 
484 	/* change control lines if we are switching to or from B0 */
485 	/* FIXME:
486 	spin_lock_irqsave(&priv->lock, flags);
487 	control = priv->line_control;
488 	if ((cflag & CBAUD) == B0)
489 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
490 	else
491 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
492 	if (control != priv->line_control) {
493 		control = priv->line_control;
494 		spin_unlock_irqrestore(&priv->lock, flags);
495 		set_control_lines(serial->dev, control);
496 	} else {
497 		spin_unlock_irqrestore(&priv->lock, flags);
498 	}
499 	*/
500 
501 	spin_lock_irqsave(&priv->lock, flags);
502 	if (divisor != priv->pending_setup.divisor
503 			|| control != priv->pending_setup.control
504 			|| frame_fmt != priv->pending_setup.frame_fmt) {
505 		priv->pending_setup.divisor = divisor;
506 		priv->pending_setup.control = control;
507 		priv->pending_setup.frame_fmt = frame_fmt;
508 	}
509 	spin_unlock_irqrestore(&priv->lock, flags);
510 }
511 
512 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port)
513 {
514 	struct oti6858_private *priv = usb_get_serial_port_data(port);
515 	struct ktermios tmp_termios;
516 	struct usb_serial *serial = port->serial;
517 	struct oti6858_control_pkt *buf;
518 	unsigned long flags;
519 	int result;
520 
521 	usb_clear_halt(serial->dev, port->write_urb->pipe);
522 	usb_clear_halt(serial->dev, port->read_urb->pipe);
523 
524 	buf = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
525 	if (buf == NULL) {
526 		dev_err(&port->dev, "%s(): out of memory!\n", __func__);
527 		return -ENOMEM;
528 	}
529 
530 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
531 				OTI6858_REQ_T_GET_STATUS,
532 				OTI6858_REQ_GET_STATUS,
533 				0, 0,
534 				buf, OTI6858_CTRL_PKT_SIZE,
535 				100);
536 	if (result != OTI6858_CTRL_PKT_SIZE) {
537 		/* assume default (after power-on reset) values */
538 		buf->divisor = cpu_to_le16(0x009c);	/* 38400 bps */
539 		buf->frame_fmt = 0x03;	/* 8N1 */
540 		buf->something = 0x43;
541 		buf->control = 0x4c;	/* DTR, RTS */
542 		buf->tx_status = 0x00;
543 		buf->pin_state = 0x5b;	/* RTS, CTS, DSR, DTR, RI, DCD */
544 		buf->rx_bytes_avail = 0x00;
545 	}
546 
547 	spin_lock_irqsave(&priv->lock, flags);
548 	memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
549 	priv->pending_setup.divisor = buf->divisor;
550 	priv->pending_setup.frame_fmt = buf->frame_fmt;
551 	priv->pending_setup.control = buf->control;
552 	spin_unlock_irqrestore(&priv->lock, flags);
553 	kfree(buf);
554 
555 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
556 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
557 	if (result != 0) {
558 		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
559 			__func__, result);
560 		oti6858_close(port);
561 		return result;
562 	}
563 
564 	/* setup termios */
565 	if (tty)
566 		oti6858_set_termios(tty, port, &tmp_termios);
567 	port->port.drain_delay = 256;	/* FIXME: check the FIFO length */
568 	return 0;
569 }
570 
571 static void oti6858_close(struct usb_serial_port *port)
572 {
573 	struct oti6858_private *priv = usb_get_serial_port_data(port);
574 	unsigned long flags;
575 
576 	spin_lock_irqsave(&port->lock, flags);
577 	/* clear out any remaining data in the buffer */
578 	kfifo_reset_out(&port->write_fifo);
579 	spin_unlock_irqrestore(&port->lock, flags);
580 
581 	dev_dbg(&port->dev, "%s(): after buf_clear()\n", __func__);
582 
583 	/* cancel scheduled setup */
584 	cancel_delayed_work_sync(&priv->delayed_setup_work);
585 	cancel_delayed_work_sync(&priv->delayed_write_work);
586 
587 	/* shutdown our urbs */
588 	dev_dbg(&port->dev, "%s(): shutting down urbs\n", __func__);
589 	usb_kill_urb(port->write_urb);
590 	usb_kill_urb(port->read_urb);
591 	usb_kill_urb(port->interrupt_in_urb);
592 }
593 
594 static int oti6858_tiocmset(struct tty_struct *tty,
595 				unsigned int set, unsigned int clear)
596 {
597 	struct usb_serial_port *port = tty->driver_data;
598 	struct oti6858_private *priv = usb_get_serial_port_data(port);
599 	unsigned long flags;
600 	u8 control;
601 
602 	dev_dbg(&port->dev, "%s(set = 0x%08x, clear = 0x%08x)\n",
603 		__func__, set, clear);
604 
605 	/* FIXME: check if this is correct (active high/low) */
606 	spin_lock_irqsave(&priv->lock, flags);
607 	control = priv->pending_setup.control;
608 	if ((set & TIOCM_RTS) != 0)
609 		control |= CONTROL_RTS_HIGH;
610 	if ((set & TIOCM_DTR) != 0)
611 		control |= CONTROL_DTR_HIGH;
612 	if ((clear & TIOCM_RTS) != 0)
613 		control &= ~CONTROL_RTS_HIGH;
614 	if ((clear & TIOCM_DTR) != 0)
615 		control &= ~CONTROL_DTR_HIGH;
616 
617 	if (control != priv->pending_setup.control)
618 		priv->pending_setup.control = control;
619 
620 	spin_unlock_irqrestore(&priv->lock, flags);
621 	return 0;
622 }
623 
624 static int oti6858_tiocmget(struct tty_struct *tty)
625 {
626 	struct usb_serial_port *port = tty->driver_data;
627 	struct oti6858_private *priv = usb_get_serial_port_data(port);
628 	unsigned long flags;
629 	unsigned pin_state;
630 	unsigned result = 0;
631 
632 	spin_lock_irqsave(&priv->lock, flags);
633 	pin_state = priv->status.pin_state & PIN_MASK;
634 	spin_unlock_irqrestore(&priv->lock, flags);
635 
636 	/* FIXME: check if this is correct (active high/low) */
637 	if ((pin_state & PIN_RTS) != 0)
638 		result |= TIOCM_RTS;
639 	if ((pin_state & PIN_CTS) != 0)
640 		result |= TIOCM_CTS;
641 	if ((pin_state & PIN_DSR) != 0)
642 		result |= TIOCM_DSR;
643 	if ((pin_state & PIN_DTR) != 0)
644 		result |= TIOCM_DTR;
645 	if ((pin_state & PIN_RI) != 0)
646 		result |= TIOCM_RI;
647 	if ((pin_state & PIN_DCD) != 0)
648 		result |= TIOCM_CD;
649 
650 	dev_dbg(&port->dev, "%s() = 0x%08x\n", __func__, result);
651 
652 	return result;
653 }
654 
655 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
656 {
657 	struct oti6858_private *priv = usb_get_serial_port_data(port);
658 	unsigned long flags;
659 	unsigned int prev, status;
660 	unsigned int changed;
661 
662 	spin_lock_irqsave(&priv->lock, flags);
663 	prev = priv->status.pin_state;
664 	spin_unlock_irqrestore(&priv->lock, flags);
665 
666 	while (1) {
667 		wait_event_interruptible(priv->intr_wait,
668 					priv->status.pin_state != prev);
669 		if (signal_pending(current))
670 			return -ERESTARTSYS;
671 
672 		spin_lock_irqsave(&priv->lock, flags);
673 		status = priv->status.pin_state & PIN_MASK;
674 		spin_unlock_irqrestore(&priv->lock, flags);
675 
676 		changed = prev ^ status;
677 		/* FIXME: check if this is correct (active high/low) */
678 		if (((arg & TIOCM_RNG) && (changed & PIN_RI)) ||
679 		    ((arg & TIOCM_DSR) && (changed & PIN_DSR)) ||
680 		    ((arg & TIOCM_CD)  && (changed & PIN_DCD)) ||
681 		    ((arg & TIOCM_CTS) && (changed & PIN_CTS)))
682 			return 0;
683 		prev = status;
684 	}
685 
686 	/* NOTREACHED */
687 	return 0;
688 }
689 
690 static int oti6858_ioctl(struct tty_struct *tty,
691 			unsigned int cmd, unsigned long arg)
692 {
693 	struct usb_serial_port *port = tty->driver_data;
694 
695 	dev_dbg(&port->dev, "%s(cmd = 0x%04x, arg = 0x%08lx)\n", __func__, cmd, arg);
696 
697 	switch (cmd) {
698 	case TIOCMIWAIT:
699 		dev_dbg(&port->dev, "%s(): TIOCMIWAIT\n", __func__);
700 		return wait_modem_info(port, arg);
701 	default:
702 		dev_dbg(&port->dev, "%s(): 0x%04x not supported\n", __func__, cmd);
703 		break;
704 	}
705 	return -ENOIOCTLCMD;
706 }
707 
708 static void oti6858_read_int_callback(struct urb *urb)
709 {
710 	struct usb_serial_port *port =  urb->context;
711 	struct oti6858_private *priv = usb_get_serial_port_data(port);
712 	int transient = 0, can_recv = 0, resubmit = 1;
713 	int status = urb->status;
714 
715 	switch (status) {
716 	case 0:
717 		/* success */
718 		break;
719 	case -ECONNRESET:
720 	case -ENOENT:
721 	case -ESHUTDOWN:
722 		/* this urb is terminated, clean up */
723 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n",
724 			__func__, status);
725 		return;
726 	default:
727 		dev_dbg(&urb->dev->dev, "%s(): nonzero urb status received: %d\n",
728 			__func__, status);
729 		break;
730 	}
731 
732 	if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
733 		struct oti6858_control_pkt *xs = urb->transfer_buffer;
734 		unsigned long flags;
735 
736 		spin_lock_irqsave(&priv->lock, flags);
737 
738 		if (!priv->transient) {
739 			if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
740 				if (xs->rx_bytes_avail == 0) {
741 					priv->transient = 4;
742 					priv->setup_done = 0;
743 					resubmit = 0;
744 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
745 					schedule_delayed_work(&priv->delayed_setup_work, 0);
746 				}
747 			}
748 		} else {
749 			if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
750 				priv->transient = 0;
751 			} else if (!priv->setup_done) {
752 				resubmit = 0;
753 			} else if (--priv->transient == 0) {
754 				if (xs->rx_bytes_avail == 0) {
755 					priv->transient = 4;
756 					priv->setup_done = 0;
757 					resubmit = 0;
758 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
759 					schedule_delayed_work(&priv->delayed_setup_work, 0);
760 				}
761 			}
762 		}
763 
764 		if (!priv->transient) {
765 			if (xs->pin_state != priv->status.pin_state)
766 				wake_up_interruptible(&priv->intr_wait);
767 			memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
768 		}
769 
770 		if (!priv->transient && xs->rx_bytes_avail != 0) {
771 			can_recv = xs->rx_bytes_avail;
772 			priv->flags.read_urb_in_use = 1;
773 		}
774 
775 		transient = priv->transient;
776 		spin_unlock_irqrestore(&priv->lock, flags);
777 	}
778 
779 	if (can_recv) {
780 		int result;
781 
782 		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
783 		if (result != 0) {
784 			priv->flags.read_urb_in_use = 0;
785 			dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
786 					" error %d\n", __func__, result);
787 		} else {
788 			resubmit = 0;
789 		}
790 	} else if (!transient) {
791 		unsigned long flags;
792 		int count;
793 
794 		spin_lock_irqsave(&port->lock, flags);
795 		count = kfifo_len(&port->write_fifo);
796 		spin_unlock_irqrestore(&port->lock, flags);
797 
798 		spin_lock_irqsave(&priv->lock, flags);
799 		if (priv->flags.write_urb_in_use == 0 && count != 0) {
800 			schedule_delayed_work(&priv->delayed_write_work, 0);
801 			resubmit = 0;
802 		}
803 		spin_unlock_irqrestore(&priv->lock, flags);
804 	}
805 
806 	if (resubmit) {
807 		int result;
808 
809 /*		dev_dbg(&urb->dev->dev, "%s(): submitting interrupt urb\n", __func__); */
810 		result = usb_submit_urb(urb, GFP_ATOMIC);
811 		if (result != 0) {
812 			dev_err(&urb->dev->dev,
813 					"%s(): usb_submit_urb() failed with"
814 					" error %d\n", __func__, result);
815 		}
816 	}
817 }
818 
819 static void oti6858_read_bulk_callback(struct urb *urb)
820 {
821 	struct usb_serial_port *port =  urb->context;
822 	struct oti6858_private *priv = usb_get_serial_port_data(port);
823 	struct tty_struct *tty;
824 	unsigned char *data = urb->transfer_buffer;
825 	unsigned long flags;
826 	int status = urb->status;
827 	int result;
828 
829 	spin_lock_irqsave(&priv->lock, flags);
830 	priv->flags.read_urb_in_use = 0;
831 	spin_unlock_irqrestore(&priv->lock, flags);
832 
833 	if (status != 0) {
834 		dev_dbg(&urb->dev->dev, "%s(): unable to handle the error, exiting\n", __func__);
835 		return;
836 	}
837 
838 	tty = tty_port_tty_get(&port->port);
839 	if (tty != NULL && urb->actual_length > 0) {
840 		tty_insert_flip_string(tty, data, urb->actual_length);
841 		tty_flip_buffer_push(tty);
842 	}
843 	tty_kref_put(tty);
844 
845 	/* schedule the interrupt urb */
846 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
847 	if (result != 0 && result != -EPERM) {
848 		dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
849 				" error %d\n", __func__, result);
850 	}
851 }
852 
853 static void oti6858_write_bulk_callback(struct urb *urb)
854 {
855 	struct usb_serial_port *port =  urb->context;
856 	struct oti6858_private *priv = usb_get_serial_port_data(port);
857 	int status = urb->status;
858 	int result;
859 
860 	switch (status) {
861 	case 0:
862 		/* success */
863 		break;
864 	case -ECONNRESET:
865 	case -ENOENT:
866 	case -ESHUTDOWN:
867 		/* this urb is terminated, clean up */
868 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n", __func__, status);
869 		priv->flags.write_urb_in_use = 0;
870 		return;
871 	default:
872 		/* error in the urb, so we have to resubmit it */
873 		dev_dbg(&urb->dev->dev, "%s(): nonzero write bulk status received: %d\n", __func__, status);
874 		dev_dbg(&urb->dev->dev, "%s(): overflow in write\n", __func__);
875 
876 		port->write_urb->transfer_buffer_length = 1;
877 		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
878 		if (result) {
879 			dev_err_console(port, "%s(): usb_submit_urb() failed,"
880 					" error %d\n", __func__, result);
881 		} else {
882 			return;
883 		}
884 	}
885 
886 	priv->flags.write_urb_in_use = 0;
887 
888 	/* schedule the interrupt urb if we are still open */
889 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
890 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
891 	if (result != 0) {
892 		dev_err(&port->dev, "%s(): failed submitting int urb,"
893 					" error %d\n", __func__, result);
894 	}
895 }
896 
897 module_usb_serial_driver(serial_drivers, id_table);
898 
899 MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
900 MODULE_AUTHOR(OTI6858_AUTHOR);
901 MODULE_LICENSE("GPL");
902