xref: /openbmc/linux/drivers/usb/serial/oti6858.c (revision 74ce1896)
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/slab.h>
43 #include <linux/tty.h>
44 #include <linux/tty_driver.h>
45 #include <linux/tty_flip.h>
46 #include <linux/serial.h>
47 #include <linux/module.h>
48 #include <linux/moduleparam.h>
49 #include <linux/spinlock.h>
50 #include <linux/usb.h>
51 #include <linux/usb/serial.h>
52 #include <linux/uaccess.h>
53 #include <linux/kfifo.h>
54 #include "oti6858.h"
55 
56 #define OTI6858_DESCRIPTION \
57 	"Ours Technology Inc. OTi-6858 USB to serial adapter driver"
58 #define OTI6858_AUTHOR "Tomasz Michal Lukaszewski <FIXME@FIXME>"
59 
60 static const struct usb_device_id id_table[] = {
61 	{ USB_DEVICE(OTI6858_VENDOR_ID, OTI6858_PRODUCT_ID) },
62 	{ }
63 };
64 
65 MODULE_DEVICE_TABLE(usb, id_table);
66 
67 /* requests */
68 #define	OTI6858_REQ_GET_STATUS		(USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
69 #define	OTI6858_REQ_T_GET_STATUS	0x01
70 
71 #define	OTI6858_REQ_SET_LINE		(USB_DIR_OUT | USB_TYPE_VENDOR | 0x00)
72 #define	OTI6858_REQ_T_SET_LINE		0x00
73 
74 #define	OTI6858_REQ_CHECK_TXBUFF	(USB_DIR_IN | USB_TYPE_VENDOR | 0x01)
75 #define	OTI6858_REQ_T_CHECK_TXBUFF	0x00
76 
77 /* format of the control packet */
78 struct oti6858_control_pkt {
79 	__le16	divisor;	/* baud rate = 96000000 / (16 * divisor), LE */
80 #define OTI6858_MAX_BAUD_RATE	3000000
81 	u8	frame_fmt;
82 #define FMT_STOP_BITS_MASK	0xc0
83 #define FMT_STOP_BITS_1		0x00
84 #define FMT_STOP_BITS_2		0x40	/* 1.5 stop bits if FMT_DATA_BITS_5 */
85 #define FMT_PARITY_MASK		0x38
86 #define FMT_PARITY_NONE		0x00
87 #define FMT_PARITY_ODD		0x08
88 #define FMT_PARITY_EVEN		0x18
89 #define FMT_PARITY_MARK		0x28
90 #define FMT_PARITY_SPACE	0x38
91 #define FMT_DATA_BITS_MASK	0x03
92 #define FMT_DATA_BITS_5		0x00
93 #define FMT_DATA_BITS_6		0x01
94 #define FMT_DATA_BITS_7		0x02
95 #define FMT_DATA_BITS_8		0x03
96 	u8	something;	/* always equals 0x43 */
97 	u8	control;	/* settings of flow control lines */
98 #define CONTROL_MASK		0x0c
99 #define CONTROL_DTR_HIGH	0x08
100 #define CONTROL_RTS_HIGH	0x04
101 	u8	tx_status;
102 #define	TX_BUFFER_EMPTIED	0x09
103 	u8	pin_state;
104 #define PIN_MASK		0x3f
105 #define PIN_MSR_MASK		0x1b
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_port_probe(struct usb_serial_port *port);
138 static int oti6858_port_remove(struct usb_serial_port *port);
139 
140 /* device info */
141 static struct usb_serial_driver oti6858_device = {
142 	.driver = {
143 		.owner =	THIS_MODULE,
144 		.name =		"oti6858",
145 	},
146 	.id_table =		id_table,
147 	.num_ports =		1,
148 	.num_bulk_in =		1,
149 	.num_bulk_out =		1,
150 	.num_interrupt_in =	1,
151 	.open =			oti6858_open,
152 	.close =		oti6858_close,
153 	.write =		oti6858_write,
154 	.set_termios =		oti6858_set_termios,
155 	.init_termios = 	oti6858_init_termios,
156 	.tiocmget =		oti6858_tiocmget,
157 	.tiocmset =		oti6858_tiocmset,
158 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
159 	.read_bulk_callback =	oti6858_read_bulk_callback,
160 	.read_int_callback =	oti6858_read_int_callback,
161 	.write_bulk_callback =	oti6858_write_bulk_callback,
162 	.write_room =		oti6858_write_room,
163 	.chars_in_buffer =	oti6858_chars_in_buffer,
164 	.port_probe =		oti6858_port_probe,
165 	.port_remove =		oti6858_port_remove,
166 };
167 
168 static struct usb_serial_driver * const serial_drivers[] = {
169 	&oti6858_device, NULL
170 };
171 
172 struct oti6858_private {
173 	spinlock_t lock;
174 
175 	struct oti6858_control_pkt status;
176 
177 	struct {
178 		u8 read_urb_in_use;
179 		u8 write_urb_in_use;
180 	} flags;
181 	struct delayed_work delayed_write_work;
182 
183 	struct {
184 		__le16 divisor;
185 		u8 frame_fmt;
186 		u8 control;
187 	} pending_setup;
188 	u8 transient;
189 	u8 setup_done;
190 	struct delayed_work delayed_setup_work;
191 
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) {
206 		/* we will try again */
207 		schedule_delayed_work(&priv->delayed_setup_work,
208 						msecs_to_jiffies(2));
209 		return;
210 	}
211 
212 	result = usb_control_msg(port->serial->dev,
213 				usb_rcvctrlpipe(port->serial->dev, 0),
214 				OTI6858_REQ_T_GET_STATUS,
215 				OTI6858_REQ_GET_STATUS,
216 				0, 0,
217 				new_setup, OTI6858_CTRL_PKT_SIZE,
218 				100);
219 
220 	if (result != OTI6858_CTRL_PKT_SIZE) {
221 		dev_err(&port->dev, "%s(): error reading status\n", __func__);
222 		kfree(new_setup);
223 		/* we will try again */
224 		schedule_delayed_work(&priv->delayed_setup_work,
225 							msecs_to_jiffies(2));
226 		return;
227 	}
228 
229 	spin_lock_irqsave(&priv->lock, flags);
230 	if (!OTI6858_CTRL_EQUALS_PENDING(new_setup, priv)) {
231 		new_setup->divisor = priv->pending_setup.divisor;
232 		new_setup->control = priv->pending_setup.control;
233 		new_setup->frame_fmt = priv->pending_setup.frame_fmt;
234 
235 		spin_unlock_irqrestore(&priv->lock, flags);
236 		result = usb_control_msg(port->serial->dev,
237 					usb_sndctrlpipe(port->serial->dev, 0),
238 					OTI6858_REQ_T_SET_LINE,
239 					OTI6858_REQ_SET_LINE,
240 					0, 0,
241 					new_setup, OTI6858_CTRL_PKT_SIZE,
242 					100);
243 	} else {
244 		spin_unlock_irqrestore(&priv->lock, flags);
245 		result = 0;
246 	}
247 	kfree(new_setup);
248 
249 	spin_lock_irqsave(&priv->lock, flags);
250 	if (result != OTI6858_CTRL_PKT_SIZE)
251 		priv->transient = 0;
252 	priv->setup_done = 1;
253 	spin_unlock_irqrestore(&priv->lock, flags);
254 
255 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
256 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
257 	if (result != 0) {
258 		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
259 			__func__, result);
260 	}
261 }
262 
263 static void send_data(struct work_struct *work)
264 {
265 	struct oti6858_private *priv = container_of(work,
266 			struct oti6858_private, delayed_write_work.work);
267 	struct usb_serial_port *port = priv->port;
268 	int count = 0, result;
269 	unsigned long flags;
270 	u8 *allow;
271 
272 	spin_lock_irqsave(&priv->lock, flags);
273 	if (priv->flags.write_urb_in_use) {
274 		spin_unlock_irqrestore(&priv->lock, flags);
275 		schedule_delayed_work(&priv->delayed_write_work,
276 						msecs_to_jiffies(2));
277 		return;
278 	}
279 	priv->flags.write_urb_in_use = 1;
280 	spin_unlock_irqrestore(&priv->lock, flags);
281 
282 	spin_lock_irqsave(&port->lock, flags);
283 	count = kfifo_len(&port->write_fifo);
284 	spin_unlock_irqrestore(&port->lock, flags);
285 
286 	if (count > port->bulk_out_size)
287 		count = port->bulk_out_size;
288 
289 	if (count != 0) {
290 		allow = kmalloc(1, GFP_KERNEL);
291 		if (!allow)
292 			return;
293 
294 		result = usb_control_msg(port->serial->dev,
295 				usb_rcvctrlpipe(port->serial->dev, 0),
296 				OTI6858_REQ_T_CHECK_TXBUFF,
297 				OTI6858_REQ_CHECK_TXBUFF,
298 				count, 0, allow, 1, 100);
299 		if (result != 1 || *allow != 0)
300 			count = 0;
301 		kfree(allow);
302 	}
303 
304 	if (count == 0) {
305 		priv->flags.write_urb_in_use = 0;
306 
307 		dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
308 		result = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
309 		if (result != 0) {
310 			dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
311 				__func__, result);
312 		}
313 		return;
314 	}
315 
316 	count = kfifo_out_locked(&port->write_fifo,
317 					port->write_urb->transfer_buffer,
318 					count, &port->lock);
319 	port->write_urb->transfer_buffer_length = count;
320 	result = usb_submit_urb(port->write_urb, GFP_NOIO);
321 	if (result != 0) {
322 		dev_err_console(port, "%s(): usb_submit_urb() failed with error %d\n",
323 				__func__, result);
324 		priv->flags.write_urb_in_use = 0;
325 	}
326 
327 	usb_serial_port_softint(port);
328 }
329 
330 static int oti6858_port_probe(struct usb_serial_port *port)
331 {
332 	struct oti6858_private *priv;
333 
334 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
335 	if (!priv)
336 		return -ENOMEM;
337 
338 	spin_lock_init(&priv->lock);
339 	priv->port = port;
340 	INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
341 	INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);
342 
343 	usb_set_serial_port_data(port, priv);
344 
345 	port->port.drain_delay = 256;	/* FIXME: check the FIFO length */
346 
347 	return 0;
348 }
349 
350 static int oti6858_port_remove(struct usb_serial_port *port)
351 {
352 	struct oti6858_private *priv;
353 
354 	priv = usb_get_serial_port_data(port);
355 	kfree(priv);
356 
357 	return 0;
358 }
359 
360 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
361 			const unsigned char *buf, int count)
362 {
363 	if (!count)
364 		return count;
365 
366 	count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
367 
368 	return count;
369 }
370 
371 static int oti6858_write_room(struct tty_struct *tty)
372 {
373 	struct usb_serial_port *port = tty->driver_data;
374 	int room = 0;
375 	unsigned long flags;
376 
377 	spin_lock_irqsave(&port->lock, flags);
378 	room = kfifo_avail(&port->write_fifo);
379 	spin_unlock_irqrestore(&port->lock, flags);
380 
381 	return room;
382 }
383 
384 static int oti6858_chars_in_buffer(struct tty_struct *tty)
385 {
386 	struct usb_serial_port *port = tty->driver_data;
387 	int chars = 0;
388 	unsigned long flags;
389 
390 	spin_lock_irqsave(&port->lock, flags);
391 	chars = kfifo_len(&port->write_fifo);
392 	spin_unlock_irqrestore(&port->lock, flags);
393 
394 	return chars;
395 }
396 
397 static void oti6858_init_termios(struct tty_struct *tty)
398 {
399 	tty->termios = tty_std_termios;
400 	tty->termios.c_cflag = B38400 | CS8 | CREAD | HUPCL | CLOCAL;
401 	tty->termios.c_ispeed = 38400;
402 	tty->termios.c_ospeed = 38400;
403 }
404 
405 static void oti6858_set_termios(struct tty_struct *tty,
406 		struct usb_serial_port *port, struct ktermios *old_termios)
407 {
408 	struct oti6858_private *priv = usb_get_serial_port_data(port);
409 	unsigned long flags;
410 	unsigned int cflag;
411 	u8 frame_fmt, control;
412 	__le16 divisor;
413 	int br;
414 
415 	cflag = tty->termios.c_cflag;
416 
417 	spin_lock_irqsave(&priv->lock, flags);
418 	divisor = priv->pending_setup.divisor;
419 	frame_fmt = priv->pending_setup.frame_fmt;
420 	control = priv->pending_setup.control;
421 	spin_unlock_irqrestore(&priv->lock, flags);
422 
423 	frame_fmt &= ~FMT_DATA_BITS_MASK;
424 	switch (cflag & CSIZE) {
425 	case CS5:
426 		frame_fmt |= FMT_DATA_BITS_5;
427 		break;
428 	case CS6:
429 		frame_fmt |= FMT_DATA_BITS_6;
430 		break;
431 	case CS7:
432 		frame_fmt |= FMT_DATA_BITS_7;
433 		break;
434 	default:
435 	case CS8:
436 		frame_fmt |= FMT_DATA_BITS_8;
437 		break;
438 	}
439 
440 	/* manufacturer claims that this device can work with baud rates
441 	 * up to 3 Mbps; I've tested it only on 115200 bps, so I can't
442 	 * guarantee that any other baud rate will work (especially
443 	 * the higher ones)
444 	 */
445 	br = tty_get_baud_rate(tty);
446 	if (br == 0) {
447 		divisor = 0;
448 	} else {
449 		int real_br;
450 		int new_divisor;
451 		br = min(br, OTI6858_MAX_BAUD_RATE);
452 
453 		new_divisor = (96000000 + 8 * br) / (16 * br);
454 		real_br = 96000000 / (16 * new_divisor);
455 		divisor = cpu_to_le16(new_divisor);
456 		tty_encode_baud_rate(tty, real_br, real_br);
457 	}
458 
459 	frame_fmt &= ~FMT_STOP_BITS_MASK;
460 	if ((cflag & CSTOPB) != 0)
461 		frame_fmt |= FMT_STOP_BITS_2;
462 	else
463 		frame_fmt |= FMT_STOP_BITS_1;
464 
465 	frame_fmt &= ~FMT_PARITY_MASK;
466 	if ((cflag & PARENB) != 0) {
467 		if ((cflag & PARODD) != 0)
468 			frame_fmt |= FMT_PARITY_ODD;
469 		else
470 			frame_fmt |= FMT_PARITY_EVEN;
471 	} else {
472 		frame_fmt |= FMT_PARITY_NONE;
473 	}
474 
475 	control &= ~CONTROL_MASK;
476 	if ((cflag & CRTSCTS) != 0)
477 		control |= (CONTROL_DTR_HIGH | CONTROL_RTS_HIGH);
478 
479 	/* change control lines if we are switching to or from B0 */
480 	/* FIXME:
481 	spin_lock_irqsave(&priv->lock, flags);
482 	control = priv->line_control;
483 	if ((cflag & CBAUD) == B0)
484 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
485 	else
486 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
487 	if (control != priv->line_control) {
488 		control = priv->line_control;
489 		spin_unlock_irqrestore(&priv->lock, flags);
490 		set_control_lines(serial->dev, control);
491 	} else {
492 		spin_unlock_irqrestore(&priv->lock, flags);
493 	}
494 	*/
495 
496 	spin_lock_irqsave(&priv->lock, flags);
497 	if (divisor != priv->pending_setup.divisor
498 			|| control != priv->pending_setup.control
499 			|| frame_fmt != priv->pending_setup.frame_fmt) {
500 		priv->pending_setup.divisor = divisor;
501 		priv->pending_setup.control = control;
502 		priv->pending_setup.frame_fmt = frame_fmt;
503 	}
504 	spin_unlock_irqrestore(&priv->lock, flags);
505 }
506 
507 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port)
508 {
509 	struct oti6858_private *priv = usb_get_serial_port_data(port);
510 	struct usb_serial *serial = port->serial;
511 	struct oti6858_control_pkt *buf;
512 	unsigned long flags;
513 	int result;
514 
515 	usb_clear_halt(serial->dev, port->write_urb->pipe);
516 	usb_clear_halt(serial->dev, port->read_urb->pipe);
517 
518 	buf = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
519 	if (!buf)
520 		return -ENOMEM;
521 
522 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
523 				OTI6858_REQ_T_GET_STATUS,
524 				OTI6858_REQ_GET_STATUS,
525 				0, 0,
526 				buf, OTI6858_CTRL_PKT_SIZE,
527 				100);
528 	if (result != OTI6858_CTRL_PKT_SIZE) {
529 		/* assume default (after power-on reset) values */
530 		buf->divisor = cpu_to_le16(0x009c);	/* 38400 bps */
531 		buf->frame_fmt = 0x03;	/* 8N1 */
532 		buf->something = 0x43;
533 		buf->control = 0x4c;	/* DTR, RTS */
534 		buf->tx_status = 0x00;
535 		buf->pin_state = 0x5b;	/* RTS, CTS, DSR, DTR, RI, DCD */
536 		buf->rx_bytes_avail = 0x00;
537 	}
538 
539 	spin_lock_irqsave(&priv->lock, flags);
540 	memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
541 	priv->pending_setup.divisor = buf->divisor;
542 	priv->pending_setup.frame_fmt = buf->frame_fmt;
543 	priv->pending_setup.control = buf->control;
544 	spin_unlock_irqrestore(&priv->lock, flags);
545 	kfree(buf);
546 
547 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
548 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
549 	if (result != 0) {
550 		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
551 			__func__, result);
552 		oti6858_close(port);
553 		return result;
554 	}
555 
556 	/* setup termios */
557 	if (tty)
558 		oti6858_set_termios(tty, port, NULL);
559 
560 	return 0;
561 }
562 
563 static void oti6858_close(struct usb_serial_port *port)
564 {
565 	struct oti6858_private *priv = usb_get_serial_port_data(port);
566 	unsigned long flags;
567 
568 	spin_lock_irqsave(&port->lock, flags);
569 	/* clear out any remaining data in the buffer */
570 	kfifo_reset_out(&port->write_fifo);
571 	spin_unlock_irqrestore(&port->lock, flags);
572 
573 	dev_dbg(&port->dev, "%s(): after buf_clear()\n", __func__);
574 
575 	/* cancel scheduled setup */
576 	cancel_delayed_work_sync(&priv->delayed_setup_work);
577 	cancel_delayed_work_sync(&priv->delayed_write_work);
578 
579 	/* shutdown our urbs */
580 	dev_dbg(&port->dev, "%s(): shutting down urbs\n", __func__);
581 	usb_kill_urb(port->write_urb);
582 	usb_kill_urb(port->read_urb);
583 	usb_kill_urb(port->interrupt_in_urb);
584 }
585 
586 static int oti6858_tiocmset(struct tty_struct *tty,
587 				unsigned int set, unsigned int clear)
588 {
589 	struct usb_serial_port *port = tty->driver_data;
590 	struct oti6858_private *priv = usb_get_serial_port_data(port);
591 	unsigned long flags;
592 	u8 control;
593 
594 	dev_dbg(&port->dev, "%s(set = 0x%08x, clear = 0x%08x)\n",
595 		__func__, set, clear);
596 
597 	/* FIXME: check if this is correct (active high/low) */
598 	spin_lock_irqsave(&priv->lock, flags);
599 	control = priv->pending_setup.control;
600 	if ((set & TIOCM_RTS) != 0)
601 		control |= CONTROL_RTS_HIGH;
602 	if ((set & TIOCM_DTR) != 0)
603 		control |= CONTROL_DTR_HIGH;
604 	if ((clear & TIOCM_RTS) != 0)
605 		control &= ~CONTROL_RTS_HIGH;
606 	if ((clear & TIOCM_DTR) != 0)
607 		control &= ~CONTROL_DTR_HIGH;
608 
609 	if (control != priv->pending_setup.control)
610 		priv->pending_setup.control = control;
611 
612 	spin_unlock_irqrestore(&priv->lock, flags);
613 	return 0;
614 }
615 
616 static int oti6858_tiocmget(struct tty_struct *tty)
617 {
618 	struct usb_serial_port *port = tty->driver_data;
619 	struct oti6858_private *priv = usb_get_serial_port_data(port);
620 	unsigned long flags;
621 	unsigned pin_state;
622 	unsigned result = 0;
623 
624 	spin_lock_irqsave(&priv->lock, flags);
625 	pin_state = priv->status.pin_state & PIN_MASK;
626 	spin_unlock_irqrestore(&priv->lock, flags);
627 
628 	/* FIXME: check if this is correct (active high/low) */
629 	if ((pin_state & PIN_RTS) != 0)
630 		result |= TIOCM_RTS;
631 	if ((pin_state & PIN_CTS) != 0)
632 		result |= TIOCM_CTS;
633 	if ((pin_state & PIN_DSR) != 0)
634 		result |= TIOCM_DSR;
635 	if ((pin_state & PIN_DTR) != 0)
636 		result |= TIOCM_DTR;
637 	if ((pin_state & PIN_RI) != 0)
638 		result |= TIOCM_RI;
639 	if ((pin_state & PIN_DCD) != 0)
640 		result |= TIOCM_CD;
641 
642 	dev_dbg(&port->dev, "%s() = 0x%08x\n", __func__, result);
643 
644 	return result;
645 }
646 
647 static void oti6858_read_int_callback(struct urb *urb)
648 {
649 	struct usb_serial_port *port =  urb->context;
650 	struct oti6858_private *priv = usb_get_serial_port_data(port);
651 	int transient = 0, can_recv = 0, resubmit = 1;
652 	int status = urb->status;
653 
654 	switch (status) {
655 	case 0:
656 		/* success */
657 		break;
658 	case -ECONNRESET:
659 	case -ENOENT:
660 	case -ESHUTDOWN:
661 		/* this urb is terminated, clean up */
662 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n",
663 			__func__, status);
664 		return;
665 	default:
666 		dev_dbg(&urb->dev->dev, "%s(): nonzero urb status received: %d\n",
667 			__func__, status);
668 		break;
669 	}
670 
671 	if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
672 		struct oti6858_control_pkt *xs = urb->transfer_buffer;
673 		unsigned long flags;
674 
675 		spin_lock_irqsave(&priv->lock, flags);
676 
677 		if (!priv->transient) {
678 			if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
679 				if (xs->rx_bytes_avail == 0) {
680 					priv->transient = 4;
681 					priv->setup_done = 0;
682 					resubmit = 0;
683 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
684 					schedule_delayed_work(&priv->delayed_setup_work, 0);
685 				}
686 			}
687 		} else {
688 			if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
689 				priv->transient = 0;
690 			} else if (!priv->setup_done) {
691 				resubmit = 0;
692 			} else if (--priv->transient == 0) {
693 				if (xs->rx_bytes_avail == 0) {
694 					priv->transient = 4;
695 					priv->setup_done = 0;
696 					resubmit = 0;
697 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
698 					schedule_delayed_work(&priv->delayed_setup_work, 0);
699 				}
700 			}
701 		}
702 
703 		if (!priv->transient) {
704 			u8 delta = xs->pin_state ^ priv->status.pin_state;
705 
706 			if (delta & PIN_MSR_MASK) {
707 				if (delta & PIN_CTS)
708 					port->icount.cts++;
709 				if (delta & PIN_DSR)
710 					port->icount.dsr++;
711 				if (delta & PIN_RI)
712 					port->icount.rng++;
713 				if (delta & PIN_DCD)
714 					port->icount.dcd++;
715 
716 				wake_up_interruptible(&port->port.delta_msr_wait);
717 			}
718 
719 			memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
720 		}
721 
722 		if (!priv->transient && xs->rx_bytes_avail != 0) {
723 			can_recv = xs->rx_bytes_avail;
724 			priv->flags.read_urb_in_use = 1;
725 		}
726 
727 		transient = priv->transient;
728 		spin_unlock_irqrestore(&priv->lock, flags);
729 	}
730 
731 	if (can_recv) {
732 		int result;
733 
734 		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
735 		if (result != 0) {
736 			priv->flags.read_urb_in_use = 0;
737 			dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
738 					" error %d\n", __func__, result);
739 		} else {
740 			resubmit = 0;
741 		}
742 	} else if (!transient) {
743 		unsigned long flags;
744 		int count;
745 
746 		spin_lock_irqsave(&port->lock, flags);
747 		count = kfifo_len(&port->write_fifo);
748 		spin_unlock_irqrestore(&port->lock, flags);
749 
750 		spin_lock_irqsave(&priv->lock, flags);
751 		if (priv->flags.write_urb_in_use == 0 && count != 0) {
752 			schedule_delayed_work(&priv->delayed_write_work, 0);
753 			resubmit = 0;
754 		}
755 		spin_unlock_irqrestore(&priv->lock, flags);
756 	}
757 
758 	if (resubmit) {
759 		int result;
760 
761 /*		dev_dbg(&urb->dev->dev, "%s(): submitting interrupt urb\n", __func__); */
762 		result = usb_submit_urb(urb, GFP_ATOMIC);
763 		if (result != 0) {
764 			dev_err(&urb->dev->dev,
765 					"%s(): usb_submit_urb() failed with"
766 					" error %d\n", __func__, result);
767 		}
768 	}
769 }
770 
771 static void oti6858_read_bulk_callback(struct urb *urb)
772 {
773 	struct usb_serial_port *port =  urb->context;
774 	struct oti6858_private *priv = usb_get_serial_port_data(port);
775 	unsigned char *data = urb->transfer_buffer;
776 	unsigned long flags;
777 	int status = urb->status;
778 	int result;
779 
780 	spin_lock_irqsave(&priv->lock, flags);
781 	priv->flags.read_urb_in_use = 0;
782 	spin_unlock_irqrestore(&priv->lock, flags);
783 
784 	if (status != 0) {
785 		dev_dbg(&urb->dev->dev, "%s(): unable to handle the error, exiting\n", __func__);
786 		return;
787 	}
788 
789 	if (urb->actual_length > 0) {
790 		tty_insert_flip_string(&port->port, data, urb->actual_length);
791 		tty_flip_buffer_push(&port->port);
792 	}
793 
794 	/* schedule the interrupt urb */
795 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
796 	if (result != 0 && result != -EPERM) {
797 		dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
798 				" error %d\n", __func__, result);
799 	}
800 }
801 
802 static void oti6858_write_bulk_callback(struct urb *urb)
803 {
804 	struct usb_serial_port *port =  urb->context;
805 	struct oti6858_private *priv = usb_get_serial_port_data(port);
806 	int status = urb->status;
807 	int result;
808 
809 	switch (status) {
810 	case 0:
811 		/* success */
812 		break;
813 	case -ECONNRESET:
814 	case -ENOENT:
815 	case -ESHUTDOWN:
816 		/* this urb is terminated, clean up */
817 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n", __func__, status);
818 		priv->flags.write_urb_in_use = 0;
819 		return;
820 	default:
821 		/* error in the urb, so we have to resubmit it */
822 		dev_dbg(&urb->dev->dev, "%s(): nonzero write bulk status received: %d\n", __func__, status);
823 		dev_dbg(&urb->dev->dev, "%s(): overflow in write\n", __func__);
824 
825 		port->write_urb->transfer_buffer_length = 1;
826 		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
827 		if (result) {
828 			dev_err_console(port, "%s(): usb_submit_urb() failed,"
829 					" error %d\n", __func__, result);
830 		} else {
831 			return;
832 		}
833 	}
834 
835 	priv->flags.write_urb_in_use = 0;
836 
837 	/* schedule the interrupt urb if we are still open */
838 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
839 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
840 	if (result != 0) {
841 		dev_err(&port->dev, "%s(): failed submitting int urb,"
842 					" error %d\n", __func__, result);
843 	}
844 }
845 
846 module_usb_serial_driver(serial_drivers, id_table);
847 
848 MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
849 MODULE_AUTHOR(OTI6858_AUTHOR);
850 MODULE_LICENSE("GPL");
851