xref: /openbmc/linux/drivers/usb/serial/oti6858.c (revision f7777dcc)
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 void oti6858_read_int_callback(struct urb *urb);
128 static void oti6858_read_bulk_callback(struct urb *urb);
129 static void oti6858_write_bulk_callback(struct urb *urb);
130 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
131 			const unsigned char *buf, int count);
132 static int oti6858_write_room(struct tty_struct *tty);
133 static int oti6858_chars_in_buffer(struct tty_struct *tty);
134 static int oti6858_tiocmget(struct tty_struct *tty);
135 static int oti6858_tiocmset(struct tty_struct *tty,
136 				unsigned int set, unsigned int clear);
137 static int oti6858_tiocmiwait(struct tty_struct *tty, unsigned long arg);
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 	.open =			oti6858_open,
150 	.close =		oti6858_close,
151 	.write =		oti6858_write,
152 	.set_termios =		oti6858_set_termios,
153 	.init_termios = 	oti6858_init_termios,
154 	.tiocmget =		oti6858_tiocmget,
155 	.tiocmset =		oti6858_tiocmset,
156 	.tiocmiwait =		oti6858_tiocmiwait,
157 	.read_bulk_callback =	oti6858_read_bulk_callback,
158 	.read_int_callback =	oti6858_read_int_callback,
159 	.write_bulk_callback =	oti6858_write_bulk_callback,
160 	.write_room =		oti6858_write_room,
161 	.chars_in_buffer =	oti6858_chars_in_buffer,
162 	.port_probe =		oti6858_port_probe,
163 	.port_remove =		oti6858_port_remove,
164 };
165 
166 static struct usb_serial_driver * const serial_drivers[] = {
167 	&oti6858_device, NULL
168 };
169 
170 struct oti6858_private {
171 	spinlock_t lock;
172 
173 	struct oti6858_control_pkt status;
174 
175 	struct {
176 		u8 read_urb_in_use;
177 		u8 write_urb_in_use;
178 	} flags;
179 	struct delayed_work delayed_write_work;
180 
181 	struct {
182 		__le16 divisor;
183 		u8 frame_fmt;
184 		u8 control;
185 	} pending_setup;
186 	u8 transient;
187 	u8 setup_done;
188 	struct delayed_work delayed_setup_work;
189 
190 	struct usb_serial_port *port;   /* USB port with which associated */
191 };
192 
193 static void setup_line(struct work_struct *work)
194 {
195 	struct oti6858_private *priv = container_of(work,
196 			struct oti6858_private, delayed_setup_work.work);
197 	struct usb_serial_port *port = priv->port;
198 	struct oti6858_control_pkt *new_setup;
199 	unsigned long flags;
200 	int result;
201 
202 	new_setup = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
203 	if (new_setup == NULL) {
204 		dev_err(&port->dev, "%s(): out of memory!\n", __func__);
205 		/* we will try again */
206 		schedule_delayed_work(&priv->delayed_setup_work,
207 						msecs_to_jiffies(2));
208 		return;
209 	}
210 
211 	result = usb_control_msg(port->serial->dev,
212 				usb_rcvctrlpipe(port->serial->dev, 0),
213 				OTI6858_REQ_T_GET_STATUS,
214 				OTI6858_REQ_GET_STATUS,
215 				0, 0,
216 				new_setup, OTI6858_CTRL_PKT_SIZE,
217 				100);
218 
219 	if (result != OTI6858_CTRL_PKT_SIZE) {
220 		dev_err(&port->dev, "%s(): error reading status\n", __func__);
221 		kfree(new_setup);
222 		/* we will try again */
223 		schedule_delayed_work(&priv->delayed_setup_work,
224 							msecs_to_jiffies(2));
225 		return;
226 	}
227 
228 	spin_lock_irqsave(&priv->lock, flags);
229 	if (!OTI6858_CTRL_EQUALS_PENDING(new_setup, priv)) {
230 		new_setup->divisor = priv->pending_setup.divisor;
231 		new_setup->control = priv->pending_setup.control;
232 		new_setup->frame_fmt = priv->pending_setup.frame_fmt;
233 
234 		spin_unlock_irqrestore(&priv->lock, flags);
235 		result = usb_control_msg(port->serial->dev,
236 					usb_sndctrlpipe(port->serial->dev, 0),
237 					OTI6858_REQ_T_SET_LINE,
238 					OTI6858_REQ_SET_LINE,
239 					0, 0,
240 					new_setup, OTI6858_CTRL_PKT_SIZE,
241 					100);
242 	} else {
243 		spin_unlock_irqrestore(&priv->lock, flags);
244 		result = 0;
245 	}
246 	kfree(new_setup);
247 
248 	spin_lock_irqsave(&priv->lock, flags);
249 	if (result != OTI6858_CTRL_PKT_SIZE)
250 		priv->transient = 0;
251 	priv->setup_done = 1;
252 	spin_unlock_irqrestore(&priv->lock, flags);
253 
254 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
255 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
256 	if (result != 0) {
257 		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
258 			__func__, result);
259 	}
260 }
261 
262 static void send_data(struct work_struct *work)
263 {
264 	struct oti6858_private *priv = container_of(work,
265 			struct oti6858_private, delayed_write_work.work);
266 	struct usb_serial_port *port = priv->port;
267 	int count = 0, result;
268 	unsigned long flags;
269 	u8 *allow;
270 
271 	spin_lock_irqsave(&priv->lock, flags);
272 	if (priv->flags.write_urb_in_use) {
273 		spin_unlock_irqrestore(&priv->lock, flags);
274 		schedule_delayed_work(&priv->delayed_write_work,
275 						msecs_to_jiffies(2));
276 		return;
277 	}
278 	priv->flags.write_urb_in_use = 1;
279 	spin_unlock_irqrestore(&priv->lock, flags);
280 
281 	spin_lock_irqsave(&port->lock, flags);
282 	count = kfifo_len(&port->write_fifo);
283 	spin_unlock_irqrestore(&port->lock, flags);
284 
285 	if (count > port->bulk_out_size)
286 		count = port->bulk_out_size;
287 
288 	if (count != 0) {
289 		allow = kmalloc(1, GFP_KERNEL);
290 		if (!allow) {
291 			dev_err_console(port, "%s(): kmalloc failed\n",
292 					__func__);
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 == NULL) {
521 		dev_err(&port->dev, "%s(): out of memory!\n", __func__);
522 		return -ENOMEM;
523 	}
524 
525 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
526 				OTI6858_REQ_T_GET_STATUS,
527 				OTI6858_REQ_GET_STATUS,
528 				0, 0,
529 				buf, OTI6858_CTRL_PKT_SIZE,
530 				100);
531 	if (result != OTI6858_CTRL_PKT_SIZE) {
532 		/* assume default (after power-on reset) values */
533 		buf->divisor = cpu_to_le16(0x009c);	/* 38400 bps */
534 		buf->frame_fmt = 0x03;	/* 8N1 */
535 		buf->something = 0x43;
536 		buf->control = 0x4c;	/* DTR, RTS */
537 		buf->tx_status = 0x00;
538 		buf->pin_state = 0x5b;	/* RTS, CTS, DSR, DTR, RI, DCD */
539 		buf->rx_bytes_avail = 0x00;
540 	}
541 
542 	spin_lock_irqsave(&priv->lock, flags);
543 	memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
544 	priv->pending_setup.divisor = buf->divisor;
545 	priv->pending_setup.frame_fmt = buf->frame_fmt;
546 	priv->pending_setup.control = buf->control;
547 	spin_unlock_irqrestore(&priv->lock, flags);
548 	kfree(buf);
549 
550 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
551 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
552 	if (result != 0) {
553 		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
554 			__func__, result);
555 		oti6858_close(port);
556 		return result;
557 	}
558 
559 	/* setup termios */
560 	if (tty)
561 		oti6858_set_termios(tty, port, NULL);
562 
563 	return 0;
564 }
565 
566 static void oti6858_close(struct usb_serial_port *port)
567 {
568 	struct oti6858_private *priv = usb_get_serial_port_data(port);
569 	unsigned long flags;
570 
571 	spin_lock_irqsave(&port->lock, flags);
572 	/* clear out any remaining data in the buffer */
573 	kfifo_reset_out(&port->write_fifo);
574 	spin_unlock_irqrestore(&port->lock, flags);
575 
576 	dev_dbg(&port->dev, "%s(): after buf_clear()\n", __func__);
577 
578 	/* cancel scheduled setup */
579 	cancel_delayed_work_sync(&priv->delayed_setup_work);
580 	cancel_delayed_work_sync(&priv->delayed_write_work);
581 
582 	/* shutdown our urbs */
583 	dev_dbg(&port->dev, "%s(): shutting down urbs\n", __func__);
584 	usb_kill_urb(port->write_urb);
585 	usb_kill_urb(port->read_urb);
586 	usb_kill_urb(port->interrupt_in_urb);
587 }
588 
589 static int oti6858_tiocmset(struct tty_struct *tty,
590 				unsigned int set, unsigned int clear)
591 {
592 	struct usb_serial_port *port = tty->driver_data;
593 	struct oti6858_private *priv = usb_get_serial_port_data(port);
594 	unsigned long flags;
595 	u8 control;
596 
597 	dev_dbg(&port->dev, "%s(set = 0x%08x, clear = 0x%08x)\n",
598 		__func__, set, clear);
599 
600 	/* FIXME: check if this is correct (active high/low) */
601 	spin_lock_irqsave(&priv->lock, flags);
602 	control = priv->pending_setup.control;
603 	if ((set & TIOCM_RTS) != 0)
604 		control |= CONTROL_RTS_HIGH;
605 	if ((set & TIOCM_DTR) != 0)
606 		control |= CONTROL_DTR_HIGH;
607 	if ((clear & TIOCM_RTS) != 0)
608 		control &= ~CONTROL_RTS_HIGH;
609 	if ((clear & TIOCM_DTR) != 0)
610 		control &= ~CONTROL_DTR_HIGH;
611 
612 	if (control != priv->pending_setup.control)
613 		priv->pending_setup.control = control;
614 
615 	spin_unlock_irqrestore(&priv->lock, flags);
616 	return 0;
617 }
618 
619 static int oti6858_tiocmget(struct tty_struct *tty)
620 {
621 	struct usb_serial_port *port = tty->driver_data;
622 	struct oti6858_private *priv = usb_get_serial_port_data(port);
623 	unsigned long flags;
624 	unsigned pin_state;
625 	unsigned result = 0;
626 
627 	spin_lock_irqsave(&priv->lock, flags);
628 	pin_state = priv->status.pin_state & PIN_MASK;
629 	spin_unlock_irqrestore(&priv->lock, flags);
630 
631 	/* FIXME: check if this is correct (active high/low) */
632 	if ((pin_state & PIN_RTS) != 0)
633 		result |= TIOCM_RTS;
634 	if ((pin_state & PIN_CTS) != 0)
635 		result |= TIOCM_CTS;
636 	if ((pin_state & PIN_DSR) != 0)
637 		result |= TIOCM_DSR;
638 	if ((pin_state & PIN_DTR) != 0)
639 		result |= TIOCM_DTR;
640 	if ((pin_state & PIN_RI) != 0)
641 		result |= TIOCM_RI;
642 	if ((pin_state & PIN_DCD) != 0)
643 		result |= TIOCM_CD;
644 
645 	dev_dbg(&port->dev, "%s() = 0x%08x\n", __func__, result);
646 
647 	return result;
648 }
649 
650 static int oti6858_tiocmiwait(struct tty_struct *tty, unsigned long arg)
651 {
652 	struct usb_serial_port *port = tty->driver_data;
653 	struct oti6858_private *priv = usb_get_serial_port_data(port);
654 	unsigned long flags;
655 	unsigned int prev, status;
656 	unsigned int changed;
657 
658 	spin_lock_irqsave(&priv->lock, flags);
659 	prev = priv->status.pin_state;
660 	spin_unlock_irqrestore(&priv->lock, flags);
661 
662 	while (1) {
663 		wait_event_interruptible(port->port.delta_msr_wait,
664 					port->serial->disconnected ||
665 					priv->status.pin_state != prev);
666 		if (signal_pending(current))
667 			return -ERESTARTSYS;
668 
669 		if (port->serial->disconnected)
670 			return -EIO;
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 void oti6858_read_int_callback(struct urb *urb)
691 {
692 	struct usb_serial_port *port =  urb->context;
693 	struct oti6858_private *priv = usb_get_serial_port_data(port);
694 	int transient = 0, can_recv = 0, resubmit = 1;
695 	int status = urb->status;
696 
697 	switch (status) {
698 	case 0:
699 		/* success */
700 		break;
701 	case -ECONNRESET:
702 	case -ENOENT:
703 	case -ESHUTDOWN:
704 		/* this urb is terminated, clean up */
705 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n",
706 			__func__, status);
707 		return;
708 	default:
709 		dev_dbg(&urb->dev->dev, "%s(): nonzero urb status received: %d\n",
710 			__func__, status);
711 		break;
712 	}
713 
714 	if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
715 		struct oti6858_control_pkt *xs = urb->transfer_buffer;
716 		unsigned long flags;
717 
718 		spin_lock_irqsave(&priv->lock, flags);
719 
720 		if (!priv->transient) {
721 			if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
722 				if (xs->rx_bytes_avail == 0) {
723 					priv->transient = 4;
724 					priv->setup_done = 0;
725 					resubmit = 0;
726 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
727 					schedule_delayed_work(&priv->delayed_setup_work, 0);
728 				}
729 			}
730 		} else {
731 			if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
732 				priv->transient = 0;
733 			} else if (!priv->setup_done) {
734 				resubmit = 0;
735 			} else if (--priv->transient == 0) {
736 				if (xs->rx_bytes_avail == 0) {
737 					priv->transient = 4;
738 					priv->setup_done = 0;
739 					resubmit = 0;
740 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
741 					schedule_delayed_work(&priv->delayed_setup_work, 0);
742 				}
743 			}
744 		}
745 
746 		if (!priv->transient) {
747 			if (xs->pin_state != priv->status.pin_state)
748 				wake_up_interruptible(&port->port.delta_msr_wait);
749 			memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
750 		}
751 
752 		if (!priv->transient && xs->rx_bytes_avail != 0) {
753 			can_recv = xs->rx_bytes_avail;
754 			priv->flags.read_urb_in_use = 1;
755 		}
756 
757 		transient = priv->transient;
758 		spin_unlock_irqrestore(&priv->lock, flags);
759 	}
760 
761 	if (can_recv) {
762 		int result;
763 
764 		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
765 		if (result != 0) {
766 			priv->flags.read_urb_in_use = 0;
767 			dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
768 					" error %d\n", __func__, result);
769 		} else {
770 			resubmit = 0;
771 		}
772 	} else if (!transient) {
773 		unsigned long flags;
774 		int count;
775 
776 		spin_lock_irqsave(&port->lock, flags);
777 		count = kfifo_len(&port->write_fifo);
778 		spin_unlock_irqrestore(&port->lock, flags);
779 
780 		spin_lock_irqsave(&priv->lock, flags);
781 		if (priv->flags.write_urb_in_use == 0 && count != 0) {
782 			schedule_delayed_work(&priv->delayed_write_work, 0);
783 			resubmit = 0;
784 		}
785 		spin_unlock_irqrestore(&priv->lock, flags);
786 	}
787 
788 	if (resubmit) {
789 		int result;
790 
791 /*		dev_dbg(&urb->dev->dev, "%s(): submitting interrupt urb\n", __func__); */
792 		result = usb_submit_urb(urb, GFP_ATOMIC);
793 		if (result != 0) {
794 			dev_err(&urb->dev->dev,
795 					"%s(): usb_submit_urb() failed with"
796 					" error %d\n", __func__, result);
797 		}
798 	}
799 }
800 
801 static void oti6858_read_bulk_callback(struct urb *urb)
802 {
803 	struct usb_serial_port *port =  urb->context;
804 	struct oti6858_private *priv = usb_get_serial_port_data(port);
805 	unsigned char *data = urb->transfer_buffer;
806 	unsigned long flags;
807 	int status = urb->status;
808 	int result;
809 
810 	spin_lock_irqsave(&priv->lock, flags);
811 	priv->flags.read_urb_in_use = 0;
812 	spin_unlock_irqrestore(&priv->lock, flags);
813 
814 	if (status != 0) {
815 		dev_dbg(&urb->dev->dev, "%s(): unable to handle the error, exiting\n", __func__);
816 		return;
817 	}
818 
819 	if (urb->actual_length > 0) {
820 		tty_insert_flip_string(&port->port, data, urb->actual_length);
821 		tty_flip_buffer_push(&port->port);
822 	}
823 
824 	/* schedule the interrupt urb */
825 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
826 	if (result != 0 && result != -EPERM) {
827 		dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
828 				" error %d\n", __func__, result);
829 	}
830 }
831 
832 static void oti6858_write_bulk_callback(struct urb *urb)
833 {
834 	struct usb_serial_port *port =  urb->context;
835 	struct oti6858_private *priv = usb_get_serial_port_data(port);
836 	int status = urb->status;
837 	int result;
838 
839 	switch (status) {
840 	case 0:
841 		/* success */
842 		break;
843 	case -ECONNRESET:
844 	case -ENOENT:
845 	case -ESHUTDOWN:
846 		/* this urb is terminated, clean up */
847 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n", __func__, status);
848 		priv->flags.write_urb_in_use = 0;
849 		return;
850 	default:
851 		/* error in the urb, so we have to resubmit it */
852 		dev_dbg(&urb->dev->dev, "%s(): nonzero write bulk status received: %d\n", __func__, status);
853 		dev_dbg(&urb->dev->dev, "%s(): overflow in write\n", __func__);
854 
855 		port->write_urb->transfer_buffer_length = 1;
856 		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
857 		if (result) {
858 			dev_err_console(port, "%s(): usb_submit_urb() failed,"
859 					" error %d\n", __func__, result);
860 		} else {
861 			return;
862 		}
863 	}
864 
865 	priv->flags.write_urb_in_use = 0;
866 
867 	/* schedule the interrupt urb if we are still open */
868 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
869 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
870 	if (result != 0) {
871 		dev_err(&port->dev, "%s(): failed submitting int urb,"
872 					" error %d\n", __func__, result);
873 	}
874 }
875 
876 module_usb_serial_driver(serial_drivers, id_table);
877 
878 MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
879 MODULE_AUTHOR(OTI6858_AUTHOR);
880 MODULE_LICENSE("GPL");
881