xref: /openbmc/linux/drivers/usb/serial/oti6858.c (revision 9cdb81c7)
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 #define OTI6858_VERSION "0.2"
61 
62 static const struct usb_device_id id_table[] = {
63 	{ USB_DEVICE(OTI6858_VENDOR_ID, OTI6858_PRODUCT_ID) },
64 	{ }
65 };
66 
67 MODULE_DEVICE_TABLE(usb, id_table);
68 
69 static struct usb_driver oti6858_driver = {
70 	.name =		"oti6858",
71 	.probe =	usb_serial_probe,
72 	.disconnect =	usb_serial_disconnect,
73 	.id_table =	id_table,
74 };
75 
76 static bool debug;
77 
78 /* requests */
79 #define	OTI6858_REQ_GET_STATUS		(USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
80 #define	OTI6858_REQ_T_GET_STATUS	0x01
81 
82 #define	OTI6858_REQ_SET_LINE		(USB_DIR_OUT | USB_TYPE_VENDOR | 0x00)
83 #define	OTI6858_REQ_T_SET_LINE		0x00
84 
85 #define	OTI6858_REQ_CHECK_TXBUFF	(USB_DIR_IN | USB_TYPE_VENDOR | 0x01)
86 #define	OTI6858_REQ_T_CHECK_TXBUFF	0x00
87 
88 /* format of the control packet */
89 struct oti6858_control_pkt {
90 	__le16	divisor;	/* baud rate = 96000000 / (16 * divisor), LE */
91 #define OTI6858_MAX_BAUD_RATE	3000000
92 	u8	frame_fmt;
93 #define FMT_STOP_BITS_MASK	0xc0
94 #define FMT_STOP_BITS_1		0x00
95 #define FMT_STOP_BITS_2		0x40	/* 1.5 stop bits if FMT_DATA_BITS_5 */
96 #define FMT_PARITY_MASK		0x38
97 #define FMT_PARITY_NONE		0x00
98 #define FMT_PARITY_ODD		0x08
99 #define FMT_PARITY_EVEN		0x18
100 #define FMT_PARITY_MARK		0x28
101 #define FMT_PARITY_SPACE	0x38
102 #define FMT_DATA_BITS_MASK	0x03
103 #define FMT_DATA_BITS_5		0x00
104 #define FMT_DATA_BITS_6		0x01
105 #define FMT_DATA_BITS_7		0x02
106 #define FMT_DATA_BITS_8		0x03
107 	u8	something;	/* always equals 0x43 */
108 	u8	control;	/* settings of flow control lines */
109 #define CONTROL_MASK		0x0c
110 #define CONTROL_DTR_HIGH	0x08
111 #define CONTROL_RTS_HIGH	0x04
112 	u8	tx_status;
113 #define	TX_BUFFER_EMPTIED	0x09
114 	u8	pin_state;
115 #define PIN_MASK		0x3f
116 #define PIN_RTS			0x20	/* output pin */
117 #define PIN_CTS			0x10	/* input pin, active low */
118 #define PIN_DSR			0x08	/* input pin, active low */
119 #define PIN_DTR			0x04	/* output pin */
120 #define PIN_RI			0x02	/* input pin, active low */
121 #define PIN_DCD			0x01	/* input pin, active low */
122 	u8	rx_bytes_avail;		/* number of bytes in rx buffer */;
123 };
124 
125 #define OTI6858_CTRL_PKT_SIZE	sizeof(struct oti6858_control_pkt)
126 #define OTI6858_CTRL_EQUALS_PENDING(a, priv) \
127 	(((a)->divisor == (priv)->pending_setup.divisor) \
128 	  && ((a)->control == (priv)->pending_setup.control) \
129 	  && ((a)->frame_fmt == (priv)->pending_setup.frame_fmt))
130 
131 /* function prototypes */
132 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port);
133 static void oti6858_close(struct usb_serial_port *port);
134 static void oti6858_set_termios(struct tty_struct *tty,
135 			struct usb_serial_port *port, struct ktermios *old);
136 static void oti6858_init_termios(struct tty_struct *tty);
137 static int oti6858_ioctl(struct tty_struct *tty,
138 			unsigned int cmd, unsigned long arg);
139 static void oti6858_read_int_callback(struct urb *urb);
140 static void oti6858_read_bulk_callback(struct urb *urb);
141 static void oti6858_write_bulk_callback(struct urb *urb);
142 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
143 			const unsigned char *buf, int count);
144 static int oti6858_write_room(struct tty_struct *tty);
145 static int oti6858_chars_in_buffer(struct tty_struct *tty);
146 static int oti6858_tiocmget(struct tty_struct *tty);
147 static int oti6858_tiocmset(struct tty_struct *tty,
148 				unsigned int set, unsigned int clear);
149 static int oti6858_startup(struct usb_serial *serial);
150 static void oti6858_release(struct usb_serial *serial);
151 
152 /* device info */
153 static struct usb_serial_driver oti6858_device = {
154 	.driver = {
155 		.owner =	THIS_MODULE,
156 		.name =		"oti6858",
157 	},
158 	.id_table =		id_table,
159 	.num_ports =		1,
160 	.open =			oti6858_open,
161 	.close =		oti6858_close,
162 	.write =		oti6858_write,
163 	.ioctl =		oti6858_ioctl,
164 	.set_termios =		oti6858_set_termios,
165 	.init_termios = 	oti6858_init_termios,
166 	.tiocmget =		oti6858_tiocmget,
167 	.tiocmset =		oti6858_tiocmset,
168 	.read_bulk_callback =	oti6858_read_bulk_callback,
169 	.read_int_callback =	oti6858_read_int_callback,
170 	.write_bulk_callback =	oti6858_write_bulk_callback,
171 	.write_room =		oti6858_write_room,
172 	.chars_in_buffer =	oti6858_chars_in_buffer,
173 	.attach =		oti6858_startup,
174 	.release =		oti6858_release,
175 };
176 
177 static struct usb_serial_driver * const serial_drivers[] = {
178 	&oti6858_device, NULL
179 };
180 
181 struct oti6858_private {
182 	spinlock_t lock;
183 
184 	struct oti6858_control_pkt status;
185 
186 	struct {
187 		u8 read_urb_in_use;
188 		u8 write_urb_in_use;
189 	} flags;
190 	struct delayed_work delayed_write_work;
191 
192 	struct {
193 		__le16 divisor;
194 		u8 frame_fmt;
195 		u8 control;
196 	} pending_setup;
197 	u8 transient;
198 	u8 setup_done;
199 	struct delayed_work delayed_setup_work;
200 
201 	wait_queue_head_t intr_wait;
202 	struct usb_serial_port *port;   /* USB port with which associated */
203 };
204 
205 static void setup_line(struct work_struct *work)
206 {
207 	struct oti6858_private *priv = container_of(work,
208 			struct oti6858_private, delayed_setup_work.work);
209 	struct usb_serial_port *port = priv->port;
210 	struct oti6858_control_pkt *new_setup;
211 	unsigned long flags;
212 	int result;
213 
214 	dbg("%s(port = %d)", __func__, port->number);
215 
216 	new_setup = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
217 	if (new_setup == NULL) {
218 		dev_err(&port->dev, "%s(): out of memory!\n", __func__);
219 		/* we will try again */
220 		schedule_delayed_work(&priv->delayed_setup_work,
221 						msecs_to_jiffies(2));
222 		return;
223 	}
224 
225 	result = usb_control_msg(port->serial->dev,
226 				usb_rcvctrlpipe(port->serial->dev, 0),
227 				OTI6858_REQ_T_GET_STATUS,
228 				OTI6858_REQ_GET_STATUS,
229 				0, 0,
230 				new_setup, OTI6858_CTRL_PKT_SIZE,
231 				100);
232 
233 	if (result != OTI6858_CTRL_PKT_SIZE) {
234 		dev_err(&port->dev, "%s(): error reading status\n", __func__);
235 		kfree(new_setup);
236 		/* we will try again */
237 		schedule_delayed_work(&priv->delayed_setup_work,
238 							msecs_to_jiffies(2));
239 		return;
240 	}
241 
242 	spin_lock_irqsave(&priv->lock, flags);
243 	if (!OTI6858_CTRL_EQUALS_PENDING(new_setup, priv)) {
244 		new_setup->divisor = priv->pending_setup.divisor;
245 		new_setup->control = priv->pending_setup.control;
246 		new_setup->frame_fmt = priv->pending_setup.frame_fmt;
247 
248 		spin_unlock_irqrestore(&priv->lock, flags);
249 		result = usb_control_msg(port->serial->dev,
250 					usb_sndctrlpipe(port->serial->dev, 0),
251 					OTI6858_REQ_T_SET_LINE,
252 					OTI6858_REQ_SET_LINE,
253 					0, 0,
254 					new_setup, OTI6858_CTRL_PKT_SIZE,
255 					100);
256 	} else {
257 		spin_unlock_irqrestore(&priv->lock, flags);
258 		result = 0;
259 	}
260 	kfree(new_setup);
261 
262 	spin_lock_irqsave(&priv->lock, flags);
263 	if (result != OTI6858_CTRL_PKT_SIZE)
264 		priv->transient = 0;
265 	priv->setup_done = 1;
266 	spin_unlock_irqrestore(&priv->lock, flags);
267 
268 	dbg("%s(): submitting interrupt urb", __func__);
269 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
270 	if (result != 0) {
271 		dev_err(&port->dev, "%s(): usb_submit_urb() failed"
272 				" with error %d\n", __func__, result);
273 	}
274 }
275 
276 static void send_data(struct work_struct *work)
277 {
278 	struct oti6858_private *priv = container_of(work,
279 			struct oti6858_private, delayed_write_work.work);
280 	struct usb_serial_port *port = priv->port;
281 	int count = 0, result;
282 	unsigned long flags;
283 	u8 *allow;
284 
285 	dbg("%s(port = %d)", __func__, port->number);
286 
287 	spin_lock_irqsave(&priv->lock, flags);
288 	if (priv->flags.write_urb_in_use) {
289 		spin_unlock_irqrestore(&priv->lock, flags);
290 		schedule_delayed_work(&priv->delayed_write_work,
291 						msecs_to_jiffies(2));
292 		return;
293 	}
294 	priv->flags.write_urb_in_use = 1;
295 	spin_unlock_irqrestore(&priv->lock, flags);
296 
297 	spin_lock_irqsave(&port->lock, flags);
298 	count = kfifo_len(&port->write_fifo);
299 	spin_unlock_irqrestore(&port->lock, flags);
300 
301 	if (count > port->bulk_out_size)
302 		count = port->bulk_out_size;
303 
304 	if (count != 0) {
305 		allow = kmalloc(1, GFP_KERNEL);
306 		if (!allow) {
307 			dev_err_console(port, "%s(): kmalloc failed\n",
308 					__func__);
309 			return;
310 		}
311 		result = usb_control_msg(port->serial->dev,
312 				usb_rcvctrlpipe(port->serial->dev, 0),
313 				OTI6858_REQ_T_CHECK_TXBUFF,
314 				OTI6858_REQ_CHECK_TXBUFF,
315 				count, 0, allow, 1, 100);
316 		if (result != 1 || *allow != 0)
317 			count = 0;
318 		kfree(allow);
319 	}
320 
321 	if (count == 0) {
322 		priv->flags.write_urb_in_use = 0;
323 
324 		dbg("%s(): submitting interrupt urb", __func__);
325 		result = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
326 		if (result != 0) {
327 			dev_err(&port->dev, "%s(): usb_submit_urb() failed"
328 				" with error %d\n", __func__, result);
329 		}
330 		return;
331 	}
332 
333 	count = kfifo_out_locked(&port->write_fifo,
334 					port->write_urb->transfer_buffer,
335 					count, &port->lock);
336 	port->write_urb->transfer_buffer_length = count;
337 	result = usb_submit_urb(port->write_urb, GFP_NOIO);
338 	if (result != 0) {
339 		dev_err_console(port, "%s(): usb_submit_urb() failed"
340 			       " with error %d\n", __func__, result);
341 		priv->flags.write_urb_in_use = 0;
342 	}
343 
344 	usb_serial_port_softint(port);
345 }
346 
347 static int oti6858_startup(struct usb_serial *serial)
348 {
349 	struct usb_serial_port *port = serial->port[0];
350 	struct oti6858_private *priv;
351 	int i;
352 
353 	for (i = 0; i < serial->num_ports; ++i) {
354 		priv = kzalloc(sizeof(struct oti6858_private), GFP_KERNEL);
355 		if (!priv)
356 			break;
357 
358 		spin_lock_init(&priv->lock);
359 		init_waitqueue_head(&priv->intr_wait);
360 /*		INIT_WORK(&priv->setup_work, setup_line, serial->port[i]); */
361 /*		INIT_WORK(&priv->write_work, send_data, serial->port[i]); */
362 		priv->port = port;
363 		INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
364 		INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);
365 
366 		usb_set_serial_port_data(serial->port[i], priv);
367 	}
368 	if (i == serial->num_ports)
369 		return 0;
370 
371 	for (--i; i >= 0; --i) {
372 		priv = usb_get_serial_port_data(serial->port[i]);
373 		kfree(priv);
374 		usb_set_serial_port_data(serial->port[i], NULL);
375 	}
376 	return -ENOMEM;
377 }
378 
379 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
380 			const unsigned char *buf, int count)
381 {
382 	dbg("%s(port = %d, count = %d)", __func__, port->number, count);
383 
384 	if (!count)
385 		return count;
386 
387 	count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
388 
389 	return count;
390 }
391 
392 static int oti6858_write_room(struct tty_struct *tty)
393 {
394 	struct usb_serial_port *port = tty->driver_data;
395 	int room = 0;
396 	unsigned long flags;
397 
398 	dbg("%s(port = %d)", __func__, port->number);
399 
400 	spin_lock_irqsave(&port->lock, flags);
401 	room = kfifo_avail(&port->write_fifo);
402 	spin_unlock_irqrestore(&port->lock, flags);
403 
404 	return room;
405 }
406 
407 static int oti6858_chars_in_buffer(struct tty_struct *tty)
408 {
409 	struct usb_serial_port *port = tty->driver_data;
410 	int chars = 0;
411 	unsigned long flags;
412 
413 	dbg("%s(port = %d)", __func__, port->number);
414 
415 	spin_lock_irqsave(&port->lock, flags);
416 	chars = kfifo_len(&port->write_fifo);
417 	spin_unlock_irqrestore(&port->lock, flags);
418 
419 	return chars;
420 }
421 
422 static void oti6858_init_termios(struct tty_struct *tty)
423 {
424 	*(tty->termios) = tty_std_termios;
425 	tty->termios->c_cflag = B38400 | CS8 | CREAD | HUPCL | CLOCAL;
426 	tty->termios->c_ispeed = 38400;
427 	tty->termios->c_ospeed = 38400;
428 }
429 
430 static void oti6858_set_termios(struct tty_struct *tty,
431 		struct usb_serial_port *port, struct ktermios *old_termios)
432 {
433 	struct oti6858_private *priv = usb_get_serial_port_data(port);
434 	unsigned long flags;
435 	unsigned int cflag;
436 	u8 frame_fmt, control;
437 	__le16 divisor;
438 	int br;
439 
440 	dbg("%s(port = %d)", __func__, port->number);
441 
442 	if (!tty) {
443 		dbg("%s(): no tty structures", __func__);
444 		return;
445 	}
446 
447 	cflag = tty->termios->c_cflag;
448 
449 	spin_lock_irqsave(&priv->lock, flags);
450 	divisor = priv->pending_setup.divisor;
451 	frame_fmt = priv->pending_setup.frame_fmt;
452 	control = priv->pending_setup.control;
453 	spin_unlock_irqrestore(&priv->lock, flags);
454 
455 	frame_fmt &= ~FMT_DATA_BITS_MASK;
456 	switch (cflag & CSIZE) {
457 	case CS5:
458 		frame_fmt |= FMT_DATA_BITS_5;
459 		break;
460 	case CS6:
461 		frame_fmt |= FMT_DATA_BITS_6;
462 		break;
463 	case CS7:
464 		frame_fmt |= FMT_DATA_BITS_7;
465 		break;
466 	default:
467 	case CS8:
468 		frame_fmt |= FMT_DATA_BITS_8;
469 		break;
470 	}
471 
472 	/* manufacturer claims that this device can work with baud rates
473 	 * up to 3 Mbps; I've tested it only on 115200 bps, so I can't
474 	 * guarantee that any other baud rate will work (especially
475 	 * the higher ones)
476 	 */
477 	br = tty_get_baud_rate(tty);
478 	if (br == 0) {
479 		divisor = 0;
480 	} else {
481 		int real_br;
482 		int new_divisor;
483 		br = min(br, OTI6858_MAX_BAUD_RATE);
484 
485 		new_divisor = (96000000 + 8 * br) / (16 * br);
486 		real_br = 96000000 / (16 * new_divisor);
487 		divisor = cpu_to_le16(new_divisor);
488 		tty_encode_baud_rate(tty, real_br, real_br);
489 	}
490 
491 	frame_fmt &= ~FMT_STOP_BITS_MASK;
492 	if ((cflag & CSTOPB) != 0)
493 		frame_fmt |= FMT_STOP_BITS_2;
494 	else
495 		frame_fmt |= FMT_STOP_BITS_1;
496 
497 	frame_fmt &= ~FMT_PARITY_MASK;
498 	if ((cflag & PARENB) != 0) {
499 		if ((cflag & PARODD) != 0)
500 			frame_fmt |= FMT_PARITY_ODD;
501 		else
502 			frame_fmt |= FMT_PARITY_EVEN;
503 	} else {
504 		frame_fmt |= FMT_PARITY_NONE;
505 	}
506 
507 	control &= ~CONTROL_MASK;
508 	if ((cflag & CRTSCTS) != 0)
509 		control |= (CONTROL_DTR_HIGH | CONTROL_RTS_HIGH);
510 
511 	/* change control lines if we are switching to or from B0 */
512 	/* FIXME:
513 	spin_lock_irqsave(&priv->lock, flags);
514 	control = priv->line_control;
515 	if ((cflag & CBAUD) == B0)
516 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
517 	else
518 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
519 	if (control != priv->line_control) {
520 		control = priv->line_control;
521 		spin_unlock_irqrestore(&priv->lock, flags);
522 		set_control_lines(serial->dev, control);
523 	} else {
524 		spin_unlock_irqrestore(&priv->lock, flags);
525 	}
526 	*/
527 
528 	spin_lock_irqsave(&priv->lock, flags);
529 	if (divisor != priv->pending_setup.divisor
530 			|| control != priv->pending_setup.control
531 			|| frame_fmt != priv->pending_setup.frame_fmt) {
532 		priv->pending_setup.divisor = divisor;
533 		priv->pending_setup.control = control;
534 		priv->pending_setup.frame_fmt = frame_fmt;
535 	}
536 	spin_unlock_irqrestore(&priv->lock, flags);
537 }
538 
539 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port)
540 {
541 	struct oti6858_private *priv = usb_get_serial_port_data(port);
542 	struct ktermios tmp_termios;
543 	struct usb_serial *serial = port->serial;
544 	struct oti6858_control_pkt *buf;
545 	unsigned long flags;
546 	int result;
547 
548 	dbg("%s(port = %d)", __func__, port->number);
549 
550 	usb_clear_halt(serial->dev, port->write_urb->pipe);
551 	usb_clear_halt(serial->dev, port->read_urb->pipe);
552 
553 	buf = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
554 	if (buf == NULL) {
555 		dev_err(&port->dev, "%s(): out of memory!\n", __func__);
556 		return -ENOMEM;
557 	}
558 
559 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
560 				OTI6858_REQ_T_GET_STATUS,
561 				OTI6858_REQ_GET_STATUS,
562 				0, 0,
563 				buf, OTI6858_CTRL_PKT_SIZE,
564 				100);
565 	if (result != OTI6858_CTRL_PKT_SIZE) {
566 		/* assume default (after power-on reset) values */
567 		buf->divisor = cpu_to_le16(0x009c);	/* 38400 bps */
568 		buf->frame_fmt = 0x03;	/* 8N1 */
569 		buf->something = 0x43;
570 		buf->control = 0x4c;	/* DTR, RTS */
571 		buf->tx_status = 0x00;
572 		buf->pin_state = 0x5b;	/* RTS, CTS, DSR, DTR, RI, DCD */
573 		buf->rx_bytes_avail = 0x00;
574 	}
575 
576 	spin_lock_irqsave(&priv->lock, flags);
577 	memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
578 	priv->pending_setup.divisor = buf->divisor;
579 	priv->pending_setup.frame_fmt = buf->frame_fmt;
580 	priv->pending_setup.control = buf->control;
581 	spin_unlock_irqrestore(&priv->lock, flags);
582 	kfree(buf);
583 
584 	dbg("%s(): submitting interrupt urb", __func__);
585 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
586 	if (result != 0) {
587 		dev_err(&port->dev, "%s(): usb_submit_urb() failed"
588 			       " with error %d\n", __func__, result);
589 		oti6858_close(port);
590 		return result;
591 	}
592 
593 	/* setup termios */
594 	if (tty)
595 		oti6858_set_termios(tty, port, &tmp_termios);
596 	port->port.drain_delay = 256;	/* FIXME: check the FIFO length */
597 	return 0;
598 }
599 
600 static void oti6858_close(struct usb_serial_port *port)
601 {
602 	struct oti6858_private *priv = usb_get_serial_port_data(port);
603 	unsigned long flags;
604 
605 	dbg("%s(port = %d)", __func__, port->number);
606 
607 	spin_lock_irqsave(&port->lock, flags);
608 	/* clear out any remaining data in the buffer */
609 	kfifo_reset_out(&port->write_fifo);
610 	spin_unlock_irqrestore(&port->lock, flags);
611 
612 	dbg("%s(): after buf_clear()", __func__);
613 
614 	/* cancel scheduled setup */
615 	cancel_delayed_work_sync(&priv->delayed_setup_work);
616 	cancel_delayed_work_sync(&priv->delayed_write_work);
617 
618 	/* shutdown our urbs */
619 	dbg("%s(): shutting down urbs", __func__);
620 	usb_kill_urb(port->write_urb);
621 	usb_kill_urb(port->read_urb);
622 	usb_kill_urb(port->interrupt_in_urb);
623 }
624 
625 static int oti6858_tiocmset(struct tty_struct *tty,
626 				unsigned int set, unsigned int clear)
627 {
628 	struct usb_serial_port *port = tty->driver_data;
629 	struct oti6858_private *priv = usb_get_serial_port_data(port);
630 	unsigned long flags;
631 	u8 control;
632 
633 	dbg("%s(port = %d, set = 0x%08x, clear = 0x%08x)",
634 				__func__, port->number, set, clear);
635 
636 	if (!usb_get_intfdata(port->serial->interface))
637 		return -ENODEV;
638 
639 	/* FIXME: check if this is correct (active high/low) */
640 	spin_lock_irqsave(&priv->lock, flags);
641 	control = priv->pending_setup.control;
642 	if ((set & TIOCM_RTS) != 0)
643 		control |= CONTROL_RTS_HIGH;
644 	if ((set & TIOCM_DTR) != 0)
645 		control |= CONTROL_DTR_HIGH;
646 	if ((clear & TIOCM_RTS) != 0)
647 		control &= ~CONTROL_RTS_HIGH;
648 	if ((clear & TIOCM_DTR) != 0)
649 		control &= ~CONTROL_DTR_HIGH;
650 
651 	if (control != priv->pending_setup.control)
652 		priv->pending_setup.control = control;
653 
654 	spin_unlock_irqrestore(&priv->lock, flags);
655 	return 0;
656 }
657 
658 static int oti6858_tiocmget(struct tty_struct *tty)
659 {
660 	struct usb_serial_port *port = tty->driver_data;
661 	struct oti6858_private *priv = usb_get_serial_port_data(port);
662 	unsigned long flags;
663 	unsigned pin_state;
664 	unsigned result = 0;
665 
666 	dbg("%s(port = %d)", __func__, port->number);
667 
668 	if (!usb_get_intfdata(port->serial->interface))
669 		return -ENODEV;
670 
671 	spin_lock_irqsave(&priv->lock, flags);
672 	pin_state = priv->status.pin_state & PIN_MASK;
673 	spin_unlock_irqrestore(&priv->lock, flags);
674 
675 	/* FIXME: check if this is correct (active high/low) */
676 	if ((pin_state & PIN_RTS) != 0)
677 		result |= TIOCM_RTS;
678 	if ((pin_state & PIN_CTS) != 0)
679 		result |= TIOCM_CTS;
680 	if ((pin_state & PIN_DSR) != 0)
681 		result |= TIOCM_DSR;
682 	if ((pin_state & PIN_DTR) != 0)
683 		result |= TIOCM_DTR;
684 	if ((pin_state & PIN_RI) != 0)
685 		result |= TIOCM_RI;
686 	if ((pin_state & PIN_DCD) != 0)
687 		result |= TIOCM_CD;
688 
689 	dbg("%s() = 0x%08x", __func__, result);
690 
691 	return result;
692 }
693 
694 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
695 {
696 	struct oti6858_private *priv = usb_get_serial_port_data(port);
697 	unsigned long flags;
698 	unsigned int prev, status;
699 	unsigned int changed;
700 
701 	spin_lock_irqsave(&priv->lock, flags);
702 	prev = priv->status.pin_state;
703 	spin_unlock_irqrestore(&priv->lock, flags);
704 
705 	while (1) {
706 		wait_event_interruptible(priv->intr_wait,
707 					priv->status.pin_state != prev);
708 		if (signal_pending(current))
709 			return -ERESTARTSYS;
710 
711 		spin_lock_irqsave(&priv->lock, flags);
712 		status = priv->status.pin_state & PIN_MASK;
713 		spin_unlock_irqrestore(&priv->lock, flags);
714 
715 		changed = prev ^ status;
716 		/* FIXME: check if this is correct (active high/low) */
717 		if (((arg & TIOCM_RNG) && (changed & PIN_RI)) ||
718 		    ((arg & TIOCM_DSR) && (changed & PIN_DSR)) ||
719 		    ((arg & TIOCM_CD)  && (changed & PIN_DCD)) ||
720 		    ((arg & TIOCM_CTS) && (changed & PIN_CTS)))
721 			return 0;
722 		prev = status;
723 	}
724 
725 	/* NOTREACHED */
726 	return 0;
727 }
728 
729 static int oti6858_ioctl(struct tty_struct *tty,
730 			unsigned int cmd, unsigned long arg)
731 {
732 	struct usb_serial_port *port = tty->driver_data;
733 
734 	dbg("%s(port = %d, cmd = 0x%04x, arg = 0x%08lx)",
735 				__func__, port->number, cmd, arg);
736 
737 	switch (cmd) {
738 	case TIOCMIWAIT:
739 		dbg("%s(): TIOCMIWAIT", __func__);
740 		return wait_modem_info(port, arg);
741 	default:
742 		dbg("%s(): 0x%04x not supported", __func__, cmd);
743 		break;
744 	}
745 	return -ENOIOCTLCMD;
746 }
747 
748 
749 static void oti6858_release(struct usb_serial *serial)
750 {
751 	int i;
752 
753 	dbg("%s()", __func__);
754 
755 	for (i = 0; i < serial->num_ports; ++i)
756 		kfree(usb_get_serial_port_data(serial->port[i]));
757 }
758 
759 static void oti6858_read_int_callback(struct urb *urb)
760 {
761 	struct usb_serial_port *port =  urb->context;
762 	struct oti6858_private *priv = usb_get_serial_port_data(port);
763 	int transient = 0, can_recv = 0, resubmit = 1;
764 	int status = urb->status;
765 
766 	dbg("%s(port = %d, status = %d)",
767 				__func__, port->number, status);
768 
769 	switch (status) {
770 	case 0:
771 		/* success */
772 		break;
773 	case -ECONNRESET:
774 	case -ENOENT:
775 	case -ESHUTDOWN:
776 		/* this urb is terminated, clean up */
777 		dbg("%s(): urb shutting down with status: %d",
778 					__func__, status);
779 		return;
780 	default:
781 		dbg("%s(): nonzero urb status received: %d",
782 					__func__, status);
783 		break;
784 	}
785 
786 	if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
787 		struct oti6858_control_pkt *xs = urb->transfer_buffer;
788 		unsigned long flags;
789 
790 		spin_lock_irqsave(&priv->lock, flags);
791 
792 		if (!priv->transient) {
793 			if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
794 				if (xs->rx_bytes_avail == 0) {
795 					priv->transient = 4;
796 					priv->setup_done = 0;
797 					resubmit = 0;
798 					dbg("%s(): scheduling setup_line()",
799 					    __func__);
800 					schedule_delayed_work(&priv->delayed_setup_work, 0);
801 				}
802 			}
803 		} else {
804 			if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
805 				priv->transient = 0;
806 			} else if (!priv->setup_done) {
807 				resubmit = 0;
808 			} else if (--priv->transient == 0) {
809 				if (xs->rx_bytes_avail == 0) {
810 					priv->transient = 4;
811 					priv->setup_done = 0;
812 					resubmit = 0;
813 					dbg("%s(): scheduling setup_line()",
814 					    __func__);
815 					schedule_delayed_work(&priv->delayed_setup_work, 0);
816 				}
817 			}
818 		}
819 
820 		if (!priv->transient) {
821 			if (xs->pin_state != priv->status.pin_state)
822 				wake_up_interruptible(&priv->intr_wait);
823 			memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
824 		}
825 
826 		if (!priv->transient && xs->rx_bytes_avail != 0) {
827 			can_recv = xs->rx_bytes_avail;
828 			priv->flags.read_urb_in_use = 1;
829 		}
830 
831 		transient = priv->transient;
832 		spin_unlock_irqrestore(&priv->lock, flags);
833 	}
834 
835 	if (can_recv) {
836 		int result;
837 
838 		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
839 		if (result != 0) {
840 			priv->flags.read_urb_in_use = 0;
841 			dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
842 					" error %d\n", __func__, result);
843 		} else {
844 			resubmit = 0;
845 		}
846 	} else if (!transient) {
847 		unsigned long flags;
848 		int count;
849 
850 		spin_lock_irqsave(&port->lock, flags);
851 		count = kfifo_len(&port->write_fifo);
852 		spin_unlock_irqrestore(&port->lock, flags);
853 
854 		spin_lock_irqsave(&priv->lock, flags);
855 		if (priv->flags.write_urb_in_use == 0 && count != 0) {
856 			schedule_delayed_work(&priv->delayed_write_work, 0);
857 			resubmit = 0;
858 		}
859 		spin_unlock_irqrestore(&priv->lock, flags);
860 	}
861 
862 	if (resubmit) {
863 		int result;
864 
865 /*		dbg("%s(): submitting interrupt urb", __func__); */
866 		result = usb_submit_urb(urb, GFP_ATOMIC);
867 		if (result != 0) {
868 			dev_err(&urb->dev->dev,
869 					"%s(): usb_submit_urb() failed with"
870 					" error %d\n", __func__, result);
871 		}
872 	}
873 }
874 
875 static void oti6858_read_bulk_callback(struct urb *urb)
876 {
877 	struct usb_serial_port *port =  urb->context;
878 	struct oti6858_private *priv = usb_get_serial_port_data(port);
879 	struct tty_struct *tty;
880 	unsigned char *data = urb->transfer_buffer;
881 	unsigned long flags;
882 	int status = urb->status;
883 	int result;
884 
885 	dbg("%s(port = %d, status = %d)",
886 				__func__, port->number, status);
887 
888 	spin_lock_irqsave(&priv->lock, flags);
889 	priv->flags.read_urb_in_use = 0;
890 	spin_unlock_irqrestore(&priv->lock, flags);
891 
892 	if (status != 0) {
893 		dbg("%s(): unable to handle the error, exiting", __func__);
894 		return;
895 	}
896 
897 	tty = tty_port_tty_get(&port->port);
898 	if (tty != NULL && urb->actual_length > 0) {
899 		tty_insert_flip_string(tty, data, urb->actual_length);
900 		tty_flip_buffer_push(tty);
901 	}
902 	tty_kref_put(tty);
903 
904 	/* schedule the interrupt urb */
905 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
906 	if (result != 0 && result != -EPERM) {
907 		dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
908 				" error %d\n", __func__, result);
909 	}
910 }
911 
912 static void oti6858_write_bulk_callback(struct urb *urb)
913 {
914 	struct usb_serial_port *port =  urb->context;
915 	struct oti6858_private *priv = usb_get_serial_port_data(port);
916 	int status = urb->status;
917 	int result;
918 
919 	dbg("%s(port = %d, status = %d)",
920 				__func__, port->number, status);
921 
922 	switch (status) {
923 	case 0:
924 		/* success */
925 		break;
926 	case -ECONNRESET:
927 	case -ENOENT:
928 	case -ESHUTDOWN:
929 		/* this urb is terminated, clean up */
930 		dbg("%s(): urb shutting down with status: %d",
931 					__func__, status);
932 		priv->flags.write_urb_in_use = 0;
933 		return;
934 	default:
935 		/* error in the urb, so we have to resubmit it */
936 		dbg("%s(): nonzero write bulk status received: %d",
937 					__func__, status);
938 		dbg("%s(): overflow in write", __func__);
939 
940 		port->write_urb->transfer_buffer_length = 1;
941 		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
942 		if (result) {
943 			dev_err_console(port, "%s(): usb_submit_urb() failed,"
944 					" error %d\n", __func__, result);
945 		} else {
946 			return;
947 		}
948 	}
949 
950 	priv->flags.write_urb_in_use = 0;
951 
952 	/* schedule the interrupt urb if we are still open */
953 	dbg("%s(): submitting interrupt urb", __func__);
954 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
955 	if (result != 0) {
956 		dev_err(&port->dev, "%s(): failed submitting int urb,"
957 					" error %d\n", __func__, result);
958 	}
959 }
960 
961 module_usb_serial_driver(oti6858_driver, serial_drivers);
962 
963 MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
964 MODULE_AUTHOR(OTI6858_AUTHOR);
965 MODULE_VERSION(OTI6858_VERSION);
966 MODULE_LICENSE("GPL");
967 
968 module_param(debug, bool, S_IRUGO | S_IWUSR);
969 MODULE_PARM_DESC(debug, "enable debug output");
970 
971