xref: /linux/drivers/usb/serial/oti6858.c (revision 5fd54ace4721fc5ce2bb5aef6318fcf17f421460)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Ours Technology Inc. OTi-6858 USB to serial adapter driver.
4  *
5  * Copyleft  (C) 2007 Kees Lemmens (adapted for kernel 2.6.20)
6  * Copyright (C) 2006 Tomasz Michal Lukaszewski (FIXME: add e-mail)
7  * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
8  * Copyright (C) 2003 IBM Corp.
9  *
10  * Many thanks to the authors of pl2303 driver: all functions in this file
11  * are heavily based on pl2303 code, buffering code is a 1-to-1 copy.
12  *
13  * Warning! You use this driver on your own risk! The only official
14  * description of this device I have is datasheet from manufacturer,
15  * and it doesn't contain almost any information needed to write a driver.
16  * Almost all knowlegde used while writing this driver was gathered by:
17  *  - analyzing traffic between device and the M$ Windows 2000 driver,
18  *  - trying different bit combinations and checking pin states
19  *    with a voltmeter,
20  *  - receiving malformed frames and producing buffer overflows
21  *    to learn how errors are reported,
22  * So, THIS CODE CAN DESTROY OTi-6858 AND ANY OTHER DEVICES, THAT ARE
23  * CONNECTED TO IT!
24  *
25  * This program is free software; you can redistribute it and/or modify
26  * it under the terms of the GNU General Public License as published by
27  * the Free Software Foundation; either version 2 of the License.
28  *
29  * See Documentation/usb/usb-serial.txt for more information on using this
30  * driver
31  *
32  * TODO:
33  *  - implement correct flushing for ioctls and oti6858_close()
34  *  - check how errors (rx overflow, parity error, framing error) are reported
35  *  - implement oti6858_break_ctl()
36  *  - implement more ioctls
37  *  - test/implement flow control
38  *  - allow setting custom baud rates
39  */
40 
41 #include <linux/kernel.h>
42 #include <linux/errno.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_MSR_MASK		0x1b
107 #define PIN_RTS			0x20	/* output pin */
108 #define PIN_CTS			0x10	/* input pin, active low */
109 #define PIN_DSR			0x08	/* input pin, active low */
110 #define PIN_DTR			0x04	/* output pin */
111 #define PIN_RI			0x02	/* input pin, active low */
112 #define PIN_DCD			0x01	/* input pin, active low */
113 	u8	rx_bytes_avail;		/* number of bytes in rx buffer */;
114 };
115 
116 #define OTI6858_CTRL_PKT_SIZE	sizeof(struct oti6858_control_pkt)
117 #define OTI6858_CTRL_EQUALS_PENDING(a, priv) \
118 	(((a)->divisor == (priv)->pending_setup.divisor) \
119 	  && ((a)->control == (priv)->pending_setup.control) \
120 	  && ((a)->frame_fmt == (priv)->pending_setup.frame_fmt))
121 
122 /* function prototypes */
123 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port);
124 static void oti6858_close(struct usb_serial_port *port);
125 static void oti6858_set_termios(struct tty_struct *tty,
126 			struct usb_serial_port *port, struct ktermios *old);
127 static void oti6858_init_termios(struct tty_struct *tty);
128 static void oti6858_read_int_callback(struct urb *urb);
129 static void oti6858_read_bulk_callback(struct urb *urb);
130 static void oti6858_write_bulk_callback(struct urb *urb);
131 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
132 			const unsigned char *buf, int count);
133 static int oti6858_write_room(struct tty_struct *tty);
134 static int oti6858_chars_in_buffer(struct tty_struct *tty);
135 static int oti6858_tiocmget(struct tty_struct *tty);
136 static int oti6858_tiocmset(struct tty_struct *tty,
137 				unsigned int set, unsigned int clear);
138 static int oti6858_port_probe(struct usb_serial_port *port);
139 static int oti6858_port_remove(struct usb_serial_port *port);
140 
141 /* device info */
142 static struct usb_serial_driver oti6858_device = {
143 	.driver = {
144 		.owner =	THIS_MODULE,
145 		.name =		"oti6858",
146 	},
147 	.id_table =		id_table,
148 	.num_ports =		1,
149 	.num_bulk_in =		1,
150 	.num_bulk_out =		1,
151 	.num_interrupt_in =	1,
152 	.open =			oti6858_open,
153 	.close =		oti6858_close,
154 	.write =		oti6858_write,
155 	.set_termios =		oti6858_set_termios,
156 	.init_termios = 	oti6858_init_termios,
157 	.tiocmget =		oti6858_tiocmget,
158 	.tiocmset =		oti6858_tiocmset,
159 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
160 	.read_bulk_callback =	oti6858_read_bulk_callback,
161 	.read_int_callback =	oti6858_read_int_callback,
162 	.write_bulk_callback =	oti6858_write_bulk_callback,
163 	.write_room =		oti6858_write_room,
164 	.chars_in_buffer =	oti6858_chars_in_buffer,
165 	.port_probe =		oti6858_port_probe,
166 	.port_remove =		oti6858_port_remove,
167 };
168 
169 static struct usb_serial_driver * const serial_drivers[] = {
170 	&oti6858_device, NULL
171 };
172 
173 struct oti6858_private {
174 	spinlock_t lock;
175 
176 	struct oti6858_control_pkt status;
177 
178 	struct {
179 		u8 read_urb_in_use;
180 		u8 write_urb_in_use;
181 	} flags;
182 	struct delayed_work delayed_write_work;
183 
184 	struct {
185 		__le16 divisor;
186 		u8 frame_fmt;
187 		u8 control;
188 	} pending_setup;
189 	u8 transient;
190 	u8 setup_done;
191 	struct delayed_work delayed_setup_work;
192 
193 	struct usb_serial_port *port;   /* USB port with which associated */
194 };
195 
196 static void setup_line(struct work_struct *work)
197 {
198 	struct oti6858_private *priv = container_of(work,
199 			struct oti6858_private, delayed_setup_work.work);
200 	struct usb_serial_port *port = priv->port;
201 	struct oti6858_control_pkt *new_setup;
202 	unsigned long flags;
203 	int result;
204 
205 	new_setup = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
206 	if (!new_setup) {
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 			return;
294 
295 		result = usb_control_msg(port->serial->dev,
296 				usb_rcvctrlpipe(port->serial->dev, 0),
297 				OTI6858_REQ_T_CHECK_TXBUFF,
298 				OTI6858_REQ_CHECK_TXBUFF,
299 				count, 0, allow, 1, 100);
300 		if (result != 1 || *allow != 0)
301 			count = 0;
302 		kfree(allow);
303 	}
304 
305 	if (count == 0) {
306 		priv->flags.write_urb_in_use = 0;
307 
308 		dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
309 		result = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
310 		if (result != 0) {
311 			dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
312 				__func__, result);
313 		}
314 		return;
315 	}
316 
317 	count = kfifo_out_locked(&port->write_fifo,
318 					port->write_urb->transfer_buffer,
319 					count, &port->lock);
320 	port->write_urb->transfer_buffer_length = count;
321 	result = usb_submit_urb(port->write_urb, GFP_NOIO);
322 	if (result != 0) {
323 		dev_err_console(port, "%s(): usb_submit_urb() failed with error %d\n",
324 				__func__, result);
325 		priv->flags.write_urb_in_use = 0;
326 	}
327 
328 	usb_serial_port_softint(port);
329 }
330 
331 static int oti6858_port_probe(struct usb_serial_port *port)
332 {
333 	struct oti6858_private *priv;
334 
335 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
336 	if (!priv)
337 		return -ENOMEM;
338 
339 	spin_lock_init(&priv->lock);
340 	priv->port = port;
341 	INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
342 	INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);
343 
344 	usb_set_serial_port_data(port, priv);
345 
346 	port->port.drain_delay = 256;	/* FIXME: check the FIFO length */
347 
348 	return 0;
349 }
350 
351 static int oti6858_port_remove(struct usb_serial_port *port)
352 {
353 	struct oti6858_private *priv;
354 
355 	priv = usb_get_serial_port_data(port);
356 	kfree(priv);
357 
358 	return 0;
359 }
360 
361 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
362 			const unsigned char *buf, int count)
363 {
364 	if (!count)
365 		return count;
366 
367 	count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
368 
369 	return count;
370 }
371 
372 static int oti6858_write_room(struct tty_struct *tty)
373 {
374 	struct usb_serial_port *port = tty->driver_data;
375 	int room = 0;
376 	unsigned long flags;
377 
378 	spin_lock_irqsave(&port->lock, flags);
379 	room = kfifo_avail(&port->write_fifo);
380 	spin_unlock_irqrestore(&port->lock, flags);
381 
382 	return room;
383 }
384 
385 static int oti6858_chars_in_buffer(struct tty_struct *tty)
386 {
387 	struct usb_serial_port *port = tty->driver_data;
388 	int chars = 0;
389 	unsigned long flags;
390 
391 	spin_lock_irqsave(&port->lock, flags);
392 	chars = kfifo_len(&port->write_fifo);
393 	spin_unlock_irqrestore(&port->lock, flags);
394 
395 	return chars;
396 }
397 
398 static void oti6858_init_termios(struct tty_struct *tty)
399 {
400 	tty->termios = tty_std_termios;
401 	tty->termios.c_cflag = B38400 | CS8 | CREAD | HUPCL | CLOCAL;
402 	tty->termios.c_ispeed = 38400;
403 	tty->termios.c_ospeed = 38400;
404 }
405 
406 static void oti6858_set_termios(struct tty_struct *tty,
407 		struct usb_serial_port *port, struct ktermios *old_termios)
408 {
409 	struct oti6858_private *priv = usb_get_serial_port_data(port);
410 	unsigned long flags;
411 	unsigned int cflag;
412 	u8 frame_fmt, control;
413 	__le16 divisor;
414 	int br;
415 
416 	cflag = tty->termios.c_cflag;
417 
418 	spin_lock_irqsave(&priv->lock, flags);
419 	divisor = priv->pending_setup.divisor;
420 	frame_fmt = priv->pending_setup.frame_fmt;
421 	control = priv->pending_setup.control;
422 	spin_unlock_irqrestore(&priv->lock, flags);
423 
424 	frame_fmt &= ~FMT_DATA_BITS_MASK;
425 	switch (cflag & CSIZE) {
426 	case CS5:
427 		frame_fmt |= FMT_DATA_BITS_5;
428 		break;
429 	case CS6:
430 		frame_fmt |= FMT_DATA_BITS_6;
431 		break;
432 	case CS7:
433 		frame_fmt |= FMT_DATA_BITS_7;
434 		break;
435 	default:
436 	case CS8:
437 		frame_fmt |= FMT_DATA_BITS_8;
438 		break;
439 	}
440 
441 	/* manufacturer claims that this device can work with baud rates
442 	 * up to 3 Mbps; I've tested it only on 115200 bps, so I can't
443 	 * guarantee that any other baud rate will work (especially
444 	 * the higher ones)
445 	 */
446 	br = tty_get_baud_rate(tty);
447 	if (br == 0) {
448 		divisor = 0;
449 	} else {
450 		int real_br;
451 		int new_divisor;
452 		br = min(br, OTI6858_MAX_BAUD_RATE);
453 
454 		new_divisor = (96000000 + 8 * br) / (16 * br);
455 		real_br = 96000000 / (16 * new_divisor);
456 		divisor = cpu_to_le16(new_divisor);
457 		tty_encode_baud_rate(tty, real_br, real_br);
458 	}
459 
460 	frame_fmt &= ~FMT_STOP_BITS_MASK;
461 	if ((cflag & CSTOPB) != 0)
462 		frame_fmt |= FMT_STOP_BITS_2;
463 	else
464 		frame_fmt |= FMT_STOP_BITS_1;
465 
466 	frame_fmt &= ~FMT_PARITY_MASK;
467 	if ((cflag & PARENB) != 0) {
468 		if ((cflag & PARODD) != 0)
469 			frame_fmt |= FMT_PARITY_ODD;
470 		else
471 			frame_fmt |= FMT_PARITY_EVEN;
472 	} else {
473 		frame_fmt |= FMT_PARITY_NONE;
474 	}
475 
476 	control &= ~CONTROL_MASK;
477 	if ((cflag & CRTSCTS) != 0)
478 		control |= (CONTROL_DTR_HIGH | CONTROL_RTS_HIGH);
479 
480 	/* change control lines if we are switching to or from B0 */
481 	/* FIXME:
482 	spin_lock_irqsave(&priv->lock, flags);
483 	control = priv->line_control;
484 	if ((cflag & CBAUD) == B0)
485 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
486 	else
487 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
488 	if (control != priv->line_control) {
489 		control = priv->line_control;
490 		spin_unlock_irqrestore(&priv->lock, flags);
491 		set_control_lines(serial->dev, control);
492 	} else {
493 		spin_unlock_irqrestore(&priv->lock, flags);
494 	}
495 	*/
496 
497 	spin_lock_irqsave(&priv->lock, flags);
498 	if (divisor != priv->pending_setup.divisor
499 			|| control != priv->pending_setup.control
500 			|| frame_fmt != priv->pending_setup.frame_fmt) {
501 		priv->pending_setup.divisor = divisor;
502 		priv->pending_setup.control = control;
503 		priv->pending_setup.frame_fmt = frame_fmt;
504 	}
505 	spin_unlock_irqrestore(&priv->lock, flags);
506 }
507 
508 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port)
509 {
510 	struct oti6858_private *priv = usb_get_serial_port_data(port);
511 	struct usb_serial *serial = port->serial;
512 	struct oti6858_control_pkt *buf;
513 	unsigned long flags;
514 	int result;
515 
516 	usb_clear_halt(serial->dev, port->write_urb->pipe);
517 	usb_clear_halt(serial->dev, port->read_urb->pipe);
518 
519 	buf = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
520 	if (!buf)
521 		return -ENOMEM;
522 
523 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
524 				OTI6858_REQ_T_GET_STATUS,
525 				OTI6858_REQ_GET_STATUS,
526 				0, 0,
527 				buf, OTI6858_CTRL_PKT_SIZE,
528 				100);
529 	if (result != OTI6858_CTRL_PKT_SIZE) {
530 		/* assume default (after power-on reset) values */
531 		buf->divisor = cpu_to_le16(0x009c);	/* 38400 bps */
532 		buf->frame_fmt = 0x03;	/* 8N1 */
533 		buf->something = 0x43;
534 		buf->control = 0x4c;	/* DTR, RTS */
535 		buf->tx_status = 0x00;
536 		buf->pin_state = 0x5b;	/* RTS, CTS, DSR, DTR, RI, DCD */
537 		buf->rx_bytes_avail = 0x00;
538 	}
539 
540 	spin_lock_irqsave(&priv->lock, flags);
541 	memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
542 	priv->pending_setup.divisor = buf->divisor;
543 	priv->pending_setup.frame_fmt = buf->frame_fmt;
544 	priv->pending_setup.control = buf->control;
545 	spin_unlock_irqrestore(&priv->lock, flags);
546 	kfree(buf);
547 
548 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
549 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
550 	if (result != 0) {
551 		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
552 			__func__, result);
553 		oti6858_close(port);
554 		return result;
555 	}
556 
557 	/* setup termios */
558 	if (tty)
559 		oti6858_set_termios(tty, port, NULL);
560 
561 	return 0;
562 }
563 
564 static void oti6858_close(struct usb_serial_port *port)
565 {
566 	struct oti6858_private *priv = usb_get_serial_port_data(port);
567 	unsigned long flags;
568 
569 	spin_lock_irqsave(&port->lock, flags);
570 	/* clear out any remaining data in the buffer */
571 	kfifo_reset_out(&port->write_fifo);
572 	spin_unlock_irqrestore(&port->lock, flags);
573 
574 	dev_dbg(&port->dev, "%s(): after buf_clear()\n", __func__);
575 
576 	/* cancel scheduled setup */
577 	cancel_delayed_work_sync(&priv->delayed_setup_work);
578 	cancel_delayed_work_sync(&priv->delayed_write_work);
579 
580 	/* shutdown our urbs */
581 	dev_dbg(&port->dev, "%s(): shutting down urbs\n", __func__);
582 	usb_kill_urb(port->write_urb);
583 	usb_kill_urb(port->read_urb);
584 	usb_kill_urb(port->interrupt_in_urb);
585 }
586 
587 static int oti6858_tiocmset(struct tty_struct *tty,
588 				unsigned int set, unsigned int clear)
589 {
590 	struct usb_serial_port *port = tty->driver_data;
591 	struct oti6858_private *priv = usb_get_serial_port_data(port);
592 	unsigned long flags;
593 	u8 control;
594 
595 	dev_dbg(&port->dev, "%s(set = 0x%08x, clear = 0x%08x)\n",
596 		__func__, set, clear);
597 
598 	/* FIXME: check if this is correct (active high/low) */
599 	spin_lock_irqsave(&priv->lock, flags);
600 	control = priv->pending_setup.control;
601 	if ((set & TIOCM_RTS) != 0)
602 		control |= CONTROL_RTS_HIGH;
603 	if ((set & TIOCM_DTR) != 0)
604 		control |= CONTROL_DTR_HIGH;
605 	if ((clear & TIOCM_RTS) != 0)
606 		control &= ~CONTROL_RTS_HIGH;
607 	if ((clear & TIOCM_DTR) != 0)
608 		control &= ~CONTROL_DTR_HIGH;
609 
610 	if (control != priv->pending_setup.control)
611 		priv->pending_setup.control = control;
612 
613 	spin_unlock_irqrestore(&priv->lock, flags);
614 	return 0;
615 }
616 
617 static int oti6858_tiocmget(struct tty_struct *tty)
618 {
619 	struct usb_serial_port *port = tty->driver_data;
620 	struct oti6858_private *priv = usb_get_serial_port_data(port);
621 	unsigned long flags;
622 	unsigned pin_state;
623 	unsigned result = 0;
624 
625 	spin_lock_irqsave(&priv->lock, flags);
626 	pin_state = priv->status.pin_state & PIN_MASK;
627 	spin_unlock_irqrestore(&priv->lock, flags);
628 
629 	/* FIXME: check if this is correct (active high/low) */
630 	if ((pin_state & PIN_RTS) != 0)
631 		result |= TIOCM_RTS;
632 	if ((pin_state & PIN_CTS) != 0)
633 		result |= TIOCM_CTS;
634 	if ((pin_state & PIN_DSR) != 0)
635 		result |= TIOCM_DSR;
636 	if ((pin_state & PIN_DTR) != 0)
637 		result |= TIOCM_DTR;
638 	if ((pin_state & PIN_RI) != 0)
639 		result |= TIOCM_RI;
640 	if ((pin_state & PIN_DCD) != 0)
641 		result |= TIOCM_CD;
642 
643 	dev_dbg(&port->dev, "%s() = 0x%08x\n", __func__, result);
644 
645 	return result;
646 }
647 
648 static void oti6858_read_int_callback(struct urb *urb)
649 {
650 	struct usb_serial_port *port =  urb->context;
651 	struct oti6858_private *priv = usb_get_serial_port_data(port);
652 	int transient = 0, can_recv = 0, resubmit = 1;
653 	int status = urb->status;
654 
655 	switch (status) {
656 	case 0:
657 		/* success */
658 		break;
659 	case -ECONNRESET:
660 	case -ENOENT:
661 	case -ESHUTDOWN:
662 		/* this urb is terminated, clean up */
663 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n",
664 			__func__, status);
665 		return;
666 	default:
667 		dev_dbg(&urb->dev->dev, "%s(): nonzero urb status received: %d\n",
668 			__func__, status);
669 		break;
670 	}
671 
672 	if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
673 		struct oti6858_control_pkt *xs = urb->transfer_buffer;
674 		unsigned long flags;
675 
676 		spin_lock_irqsave(&priv->lock, flags);
677 
678 		if (!priv->transient) {
679 			if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
680 				if (xs->rx_bytes_avail == 0) {
681 					priv->transient = 4;
682 					priv->setup_done = 0;
683 					resubmit = 0;
684 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
685 					schedule_delayed_work(&priv->delayed_setup_work, 0);
686 				}
687 			}
688 		} else {
689 			if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
690 				priv->transient = 0;
691 			} else if (!priv->setup_done) {
692 				resubmit = 0;
693 			} else if (--priv->transient == 0) {
694 				if (xs->rx_bytes_avail == 0) {
695 					priv->transient = 4;
696 					priv->setup_done = 0;
697 					resubmit = 0;
698 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
699 					schedule_delayed_work(&priv->delayed_setup_work, 0);
700 				}
701 			}
702 		}
703 
704 		if (!priv->transient) {
705 			u8 delta = xs->pin_state ^ priv->status.pin_state;
706 
707 			if (delta & PIN_MSR_MASK) {
708 				if (delta & PIN_CTS)
709 					port->icount.cts++;
710 				if (delta & PIN_DSR)
711 					port->icount.dsr++;
712 				if (delta & PIN_RI)
713 					port->icount.rng++;
714 				if (delta & PIN_DCD)
715 					port->icount.dcd++;
716 
717 				wake_up_interruptible(&port->port.delta_msr_wait);
718 			}
719 
720 			memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
721 		}
722 
723 		if (!priv->transient && xs->rx_bytes_avail != 0) {
724 			can_recv = xs->rx_bytes_avail;
725 			priv->flags.read_urb_in_use = 1;
726 		}
727 
728 		transient = priv->transient;
729 		spin_unlock_irqrestore(&priv->lock, flags);
730 	}
731 
732 	if (can_recv) {
733 		int result;
734 
735 		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
736 		if (result != 0) {
737 			priv->flags.read_urb_in_use = 0;
738 			dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
739 					" error %d\n", __func__, result);
740 		} else {
741 			resubmit = 0;
742 		}
743 	} else if (!transient) {
744 		unsigned long flags;
745 		int count;
746 
747 		spin_lock_irqsave(&port->lock, flags);
748 		count = kfifo_len(&port->write_fifo);
749 		spin_unlock_irqrestore(&port->lock, flags);
750 
751 		spin_lock_irqsave(&priv->lock, flags);
752 		if (priv->flags.write_urb_in_use == 0 && count != 0) {
753 			schedule_delayed_work(&priv->delayed_write_work, 0);
754 			resubmit = 0;
755 		}
756 		spin_unlock_irqrestore(&priv->lock, flags);
757 	}
758 
759 	if (resubmit) {
760 		int result;
761 
762 /*		dev_dbg(&urb->dev->dev, "%s(): submitting interrupt urb\n", __func__); */
763 		result = usb_submit_urb(urb, GFP_ATOMIC);
764 		if (result != 0) {
765 			dev_err(&urb->dev->dev,
766 					"%s(): usb_submit_urb() failed with"
767 					" error %d\n", __func__, result);
768 		}
769 	}
770 }
771 
772 static void oti6858_read_bulk_callback(struct urb *urb)
773 {
774 	struct usb_serial_port *port =  urb->context;
775 	struct oti6858_private *priv = usb_get_serial_port_data(port);
776 	unsigned char *data = urb->transfer_buffer;
777 	unsigned long flags;
778 	int status = urb->status;
779 	int result;
780 
781 	spin_lock_irqsave(&priv->lock, flags);
782 	priv->flags.read_urb_in_use = 0;
783 	spin_unlock_irqrestore(&priv->lock, flags);
784 
785 	if (status != 0) {
786 		dev_dbg(&urb->dev->dev, "%s(): unable to handle the error, exiting\n", __func__);
787 		return;
788 	}
789 
790 	if (urb->actual_length > 0) {
791 		tty_insert_flip_string(&port->port, data, urb->actual_length);
792 		tty_flip_buffer_push(&port->port);
793 	}
794 
795 	/* schedule the interrupt urb */
796 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
797 	if (result != 0 && result != -EPERM) {
798 		dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
799 				" error %d\n", __func__, result);
800 	}
801 }
802 
803 static void oti6858_write_bulk_callback(struct urb *urb)
804 {
805 	struct usb_serial_port *port =  urb->context;
806 	struct oti6858_private *priv = usb_get_serial_port_data(port);
807 	int status = urb->status;
808 	int result;
809 
810 	switch (status) {
811 	case 0:
812 		/* success */
813 		break;
814 	case -ECONNRESET:
815 	case -ENOENT:
816 	case -ESHUTDOWN:
817 		/* this urb is terminated, clean up */
818 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n", __func__, status);
819 		priv->flags.write_urb_in_use = 0;
820 		return;
821 	default:
822 		/* error in the urb, so we have to resubmit it */
823 		dev_dbg(&urb->dev->dev, "%s(): nonzero write bulk status received: %d\n", __func__, status);
824 		dev_dbg(&urb->dev->dev, "%s(): overflow in write\n", __func__);
825 
826 		port->write_urb->transfer_buffer_length = 1;
827 		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
828 		if (result) {
829 			dev_err_console(port, "%s(): usb_submit_urb() failed,"
830 					" error %d\n", __func__, result);
831 		} else {
832 			return;
833 		}
834 	}
835 
836 	priv->flags.write_urb_in_use = 0;
837 
838 	/* schedule the interrupt urb if we are still open */
839 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
840 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
841 	if (result != 0) {
842 		dev_err(&port->dev, "%s(): failed submitting int urb,"
843 					" error %d\n", __func__, result);
844 	}
845 }
846 
847 module_usb_serial_driver(serial_drivers, id_table);
848 
849 MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
850 MODULE_AUTHOR(OTI6858_AUTHOR);
851 MODULE_LICENSE("GPL");
852