xref: /linux/drivers/usb/serial/oti6858.c (revision 2a6b6c9a226279b4f6668450ddb21ae655558087)
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  * See Documentation/usb/usb-serial.rst for more information on using this
26  * driver
27  *
28  * TODO:
29  *  - implement correct flushing for ioctls and oti6858_close()
30  *  - check how errors (rx overflow, parity error, framing error) are reported
31  *  - implement oti6858_break_ctl()
32  *  - implement more ioctls
33  *  - test/implement flow control
34  *  - allow setting custom baud rates
35  */
36 
37 #include <linux/kernel.h>
38 #include <linux/errno.h>
39 #include <linux/slab.h>
40 #include <linux/tty.h>
41 #include <linux/tty_driver.h>
42 #include <linux/tty_flip.h>
43 #include <linux/serial.h>
44 #include <linux/module.h>
45 #include <linux/moduleparam.h>
46 #include <linux/spinlock.h>
47 #include <linux/usb.h>
48 #include <linux/usb/serial.h>
49 #include <linux/uaccess.h>
50 #include <linux/kfifo.h>
51 #include "oti6858.h"
52 
53 #define OTI6858_DESCRIPTION \
54 	"Ours Technology Inc. OTi-6858 USB to serial adapter driver"
55 #define OTI6858_AUTHOR "Tomasz Michal Lukaszewski <FIXME@FIXME>"
56 
57 static const struct usb_device_id id_table[] = {
58 	{ USB_DEVICE(OTI6858_VENDOR_ID, OTI6858_PRODUCT_ID) },
59 	{ }
60 };
61 
62 MODULE_DEVICE_TABLE(usb, id_table);
63 
64 /* requests */
65 #define	OTI6858_REQ_GET_STATUS		(USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
66 #define	OTI6858_REQ_T_GET_STATUS	0x01
67 
68 #define	OTI6858_REQ_SET_LINE		(USB_DIR_OUT | USB_TYPE_VENDOR | 0x00)
69 #define	OTI6858_REQ_T_SET_LINE		0x00
70 
71 #define	OTI6858_REQ_CHECK_TXBUFF	(USB_DIR_IN | USB_TYPE_VENDOR | 0x01)
72 #define	OTI6858_REQ_T_CHECK_TXBUFF	0x00
73 
74 /* format of the control packet */
75 struct oti6858_control_pkt {
76 	__le16	divisor;	/* baud rate = 96000000 / (16 * divisor), LE */
77 #define OTI6858_MAX_BAUD_RATE	3000000
78 	u8	frame_fmt;
79 #define FMT_STOP_BITS_MASK	0xc0
80 #define FMT_STOP_BITS_1		0x00
81 #define FMT_STOP_BITS_2		0x40	/* 1.5 stop bits if FMT_DATA_BITS_5 */
82 #define FMT_PARITY_MASK		0x38
83 #define FMT_PARITY_NONE		0x00
84 #define FMT_PARITY_ODD		0x08
85 #define FMT_PARITY_EVEN		0x18
86 #define FMT_PARITY_MARK		0x28
87 #define FMT_PARITY_SPACE	0x38
88 #define FMT_DATA_BITS_MASK	0x03
89 #define FMT_DATA_BITS_5		0x00
90 #define FMT_DATA_BITS_6		0x01
91 #define FMT_DATA_BITS_7		0x02
92 #define FMT_DATA_BITS_8		0x03
93 	u8	something;	/* always equals 0x43 */
94 	u8	control;	/* settings of flow control lines */
95 #define CONTROL_MASK		0x0c
96 #define CONTROL_DTR_HIGH	0x08
97 #define CONTROL_RTS_HIGH	0x04
98 	u8	tx_status;
99 #define	TX_BUFFER_EMPTIED	0x09
100 	u8	pin_state;
101 #define PIN_MASK		0x3f
102 #define PIN_MSR_MASK		0x1b
103 #define PIN_RTS			0x20	/* output pin */
104 #define PIN_CTS			0x10	/* input pin, active low */
105 #define PIN_DSR			0x08	/* input pin, active low */
106 #define PIN_DTR			0x04	/* output pin */
107 #define PIN_RI			0x02	/* input pin, active low */
108 #define PIN_DCD			0x01	/* input pin, active low */
109 	u8	rx_bytes_avail;		/* number of bytes in rx buffer */;
110 };
111 
112 #define OTI6858_CTRL_PKT_SIZE	sizeof(struct oti6858_control_pkt)
113 #define OTI6858_CTRL_EQUALS_PENDING(a, priv) \
114 	(((a)->divisor == (priv)->pending_setup.divisor) \
115 	  && ((a)->control == (priv)->pending_setup.control) \
116 	  && ((a)->frame_fmt == (priv)->pending_setup.frame_fmt))
117 
118 /* function prototypes */
119 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port);
120 static void oti6858_close(struct usb_serial_port *port);
121 static void oti6858_set_termios(struct tty_struct *tty,
122 				struct usb_serial_port *port,
123 				const struct ktermios *old_termios);
124 static void oti6858_init_termios(struct tty_struct *tty);
125 static void oti6858_read_int_callback(struct urb *urb);
126 static void oti6858_read_bulk_callback(struct urb *urb);
127 static void oti6858_write_bulk_callback(struct urb *urb);
128 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
129 			const unsigned char *buf, int count);
130 static unsigned int oti6858_write_room(struct tty_struct *tty);
131 static unsigned int oti6858_chars_in_buffer(struct tty_struct *tty);
132 static int oti6858_tiocmget(struct tty_struct *tty);
133 static int oti6858_tiocmset(struct tty_struct *tty,
134 				unsigned int set, unsigned int clear);
135 static int oti6858_port_probe(struct usb_serial_port *port);
136 static void oti6858_port_remove(struct usb_serial_port *port);
137 
138 /* device info */
139 static struct usb_serial_driver oti6858_device = {
140 	.driver = {
141 		.owner =	THIS_MODULE,
142 		.name =		"oti6858",
143 	},
144 	.id_table =		id_table,
145 	.num_ports =		1,
146 	.num_bulk_in =		1,
147 	.num_bulk_out =		1,
148 	.num_interrupt_in =	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 =		usb_serial_generic_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) {
204 		/* we will try again */
205 		schedule_delayed_work(&priv->delayed_setup_work,
206 						msecs_to_jiffies(2));
207 		return;
208 	}
209 
210 	result = usb_control_msg(port->serial->dev,
211 				usb_rcvctrlpipe(port->serial->dev, 0),
212 				OTI6858_REQ_T_GET_STATUS,
213 				OTI6858_REQ_GET_STATUS,
214 				0, 0,
215 				new_setup, OTI6858_CTRL_PKT_SIZE,
216 				100);
217 
218 	if (result != OTI6858_CTRL_PKT_SIZE) {
219 		dev_err(&port->dev, "%s(): error reading status\n", __func__);
220 		kfree(new_setup);
221 		/* we will try again */
222 		schedule_delayed_work(&priv->delayed_setup_work,
223 							msecs_to_jiffies(2));
224 		return;
225 	}
226 
227 	spin_lock_irqsave(&priv->lock, flags);
228 	if (!OTI6858_CTRL_EQUALS_PENDING(new_setup, priv)) {
229 		new_setup->divisor = priv->pending_setup.divisor;
230 		new_setup->control = priv->pending_setup.control;
231 		new_setup->frame_fmt = priv->pending_setup.frame_fmt;
232 
233 		spin_unlock_irqrestore(&priv->lock, flags);
234 		result = usb_control_msg(port->serial->dev,
235 					usb_sndctrlpipe(port->serial->dev, 0),
236 					OTI6858_REQ_T_SET_LINE,
237 					OTI6858_REQ_SET_LINE,
238 					0, 0,
239 					new_setup, OTI6858_CTRL_PKT_SIZE,
240 					100);
241 	} else {
242 		spin_unlock_irqrestore(&priv->lock, flags);
243 		result = 0;
244 	}
245 	kfree(new_setup);
246 
247 	spin_lock_irqsave(&priv->lock, flags);
248 	if (result != OTI6858_CTRL_PKT_SIZE)
249 		priv->transient = 0;
250 	priv->setup_done = 1;
251 	spin_unlock_irqrestore(&priv->lock, flags);
252 
253 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
254 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
255 	if (result != 0) {
256 		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
257 			__func__, result);
258 	}
259 }
260 
261 static void send_data(struct work_struct *work)
262 {
263 	struct oti6858_private *priv = container_of(work,
264 			struct oti6858_private, delayed_write_work.work);
265 	struct usb_serial_port *port = priv->port;
266 	int count = 0, result;
267 	unsigned long flags;
268 	u8 *allow;
269 
270 	spin_lock_irqsave(&priv->lock, flags);
271 	if (priv->flags.write_urb_in_use) {
272 		spin_unlock_irqrestore(&priv->lock, flags);
273 		schedule_delayed_work(&priv->delayed_write_work,
274 						msecs_to_jiffies(2));
275 		return;
276 	}
277 	priv->flags.write_urb_in_use = 1;
278 	spin_unlock_irqrestore(&priv->lock, flags);
279 
280 	spin_lock_irqsave(&port->lock, flags);
281 	count = kfifo_len(&port->write_fifo);
282 	spin_unlock_irqrestore(&port->lock, flags);
283 
284 	if (count > port->bulk_out_size)
285 		count = port->bulk_out_size;
286 
287 	if (count != 0) {
288 		allow = kmalloc(1, GFP_KERNEL);
289 		if (!allow)
290 			return;
291 
292 		result = usb_control_msg(port->serial->dev,
293 				usb_rcvctrlpipe(port->serial->dev, 0),
294 				OTI6858_REQ_T_CHECK_TXBUFF,
295 				OTI6858_REQ_CHECK_TXBUFF,
296 				count, 0, allow, 1, 100);
297 		if (result != 1 || *allow != 0)
298 			count = 0;
299 		kfree(allow);
300 	}
301 
302 	if (count == 0) {
303 		priv->flags.write_urb_in_use = 0;
304 
305 		dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
306 		result = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
307 		if (result != 0) {
308 			dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
309 				__func__, result);
310 		}
311 		return;
312 	}
313 
314 	count = kfifo_out_locked(&port->write_fifo,
315 					port->write_urb->transfer_buffer,
316 					count, &port->lock);
317 	port->write_urb->transfer_buffer_length = count;
318 	result = usb_submit_urb(port->write_urb, GFP_NOIO);
319 	if (result != 0) {
320 		dev_err_console(port, "%s(): usb_submit_urb() failed with error %d\n",
321 				__func__, result);
322 		priv->flags.write_urb_in_use = 0;
323 	}
324 
325 	usb_serial_port_softint(port);
326 }
327 
328 static int oti6858_port_probe(struct usb_serial_port *port)
329 {
330 	struct oti6858_private *priv;
331 
332 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
333 	if (!priv)
334 		return -ENOMEM;
335 
336 	spin_lock_init(&priv->lock);
337 	priv->port = port;
338 	INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
339 	INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);
340 
341 	usb_set_serial_port_data(port, priv);
342 
343 	port->port.drain_delay = 256;	/* FIXME: check the FIFO length */
344 
345 	return 0;
346 }
347 
348 static void oti6858_port_remove(struct usb_serial_port *port)
349 {
350 	struct oti6858_private *priv;
351 
352 	priv = usb_get_serial_port_data(port);
353 	kfree(priv);
354 }
355 
356 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
357 			const unsigned char *buf, int count)
358 {
359 	if (!count)
360 		return count;
361 
362 	count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
363 
364 	return count;
365 }
366 
367 static unsigned int oti6858_write_room(struct tty_struct *tty)
368 {
369 	struct usb_serial_port *port = tty->driver_data;
370 	unsigned int room;
371 	unsigned long flags;
372 
373 	spin_lock_irqsave(&port->lock, flags);
374 	room = kfifo_avail(&port->write_fifo);
375 	spin_unlock_irqrestore(&port->lock, flags);
376 
377 	return room;
378 }
379 
380 static unsigned int oti6858_chars_in_buffer(struct tty_struct *tty)
381 {
382 	struct usb_serial_port *port = tty->driver_data;
383 	unsigned int chars;
384 	unsigned long flags;
385 
386 	spin_lock_irqsave(&port->lock, flags);
387 	chars = kfifo_len(&port->write_fifo);
388 	spin_unlock_irqrestore(&port->lock, flags);
389 
390 	return chars;
391 }
392 
393 static void oti6858_init_termios(struct tty_struct *tty)
394 {
395 	tty_encode_baud_rate(tty, 38400, 38400);
396 }
397 
398 static void oti6858_set_termios(struct tty_struct *tty,
399 				struct usb_serial_port *port,
400 				const struct ktermios *old_termios)
401 {
402 	struct oti6858_private *priv = usb_get_serial_port_data(port);
403 	unsigned long flags;
404 	unsigned int cflag;
405 	u8 frame_fmt, control;
406 	__le16 divisor;
407 	int br;
408 
409 	cflag = tty->termios.c_cflag;
410 
411 	spin_lock_irqsave(&priv->lock, flags);
412 	frame_fmt = priv->pending_setup.frame_fmt;
413 	control = priv->pending_setup.control;
414 	spin_unlock_irqrestore(&priv->lock, flags);
415 
416 	frame_fmt &= ~FMT_DATA_BITS_MASK;
417 	switch (cflag & CSIZE) {
418 	case CS5:
419 		frame_fmt |= FMT_DATA_BITS_5;
420 		break;
421 	case CS6:
422 		frame_fmt |= FMT_DATA_BITS_6;
423 		break;
424 	case CS7:
425 		frame_fmt |= FMT_DATA_BITS_7;
426 		break;
427 	default:
428 	case CS8:
429 		frame_fmt |= FMT_DATA_BITS_8;
430 		break;
431 	}
432 
433 	/* manufacturer claims that this device can work with baud rates
434 	 * up to 3 Mbps; I've tested it only on 115200 bps, so I can't
435 	 * guarantee that any other baud rate will work (especially
436 	 * the higher ones)
437 	 */
438 	br = tty_get_baud_rate(tty);
439 	if (br == 0) {
440 		divisor = 0;
441 	} else {
442 		int real_br;
443 		int new_divisor;
444 		br = min(br, OTI6858_MAX_BAUD_RATE);
445 
446 		new_divisor = (96000000 + 8 * br) / (16 * br);
447 		real_br = 96000000 / (16 * new_divisor);
448 		divisor = cpu_to_le16(new_divisor);
449 		tty_encode_baud_rate(tty, real_br, real_br);
450 	}
451 
452 	frame_fmt &= ~FMT_STOP_BITS_MASK;
453 	if ((cflag & CSTOPB) != 0)
454 		frame_fmt |= FMT_STOP_BITS_2;
455 	else
456 		frame_fmt |= FMT_STOP_BITS_1;
457 
458 	frame_fmt &= ~FMT_PARITY_MASK;
459 	if ((cflag & PARENB) != 0) {
460 		if ((cflag & PARODD) != 0)
461 			frame_fmt |= FMT_PARITY_ODD;
462 		else
463 			frame_fmt |= FMT_PARITY_EVEN;
464 	} else {
465 		frame_fmt |= FMT_PARITY_NONE;
466 	}
467 
468 	control &= ~CONTROL_MASK;
469 	if ((cflag & CRTSCTS) != 0)
470 		control |= (CONTROL_DTR_HIGH | CONTROL_RTS_HIGH);
471 
472 	/* change control lines if we are switching to or from B0 */
473 	/* FIXME:
474 	spin_lock_irqsave(&priv->lock, flags);
475 	control = priv->line_control;
476 	if ((cflag & CBAUD) == B0)
477 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
478 	else
479 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
480 	if (control != priv->line_control) {
481 		control = priv->line_control;
482 		spin_unlock_irqrestore(&priv->lock, flags);
483 		set_control_lines(serial->dev, control);
484 	} else {
485 		spin_unlock_irqrestore(&priv->lock, flags);
486 	}
487 	*/
488 
489 	spin_lock_irqsave(&priv->lock, flags);
490 	if (divisor != priv->pending_setup.divisor
491 			|| control != priv->pending_setup.control
492 			|| frame_fmt != priv->pending_setup.frame_fmt) {
493 		priv->pending_setup.divisor = divisor;
494 		priv->pending_setup.control = control;
495 		priv->pending_setup.frame_fmt = frame_fmt;
496 	}
497 	spin_unlock_irqrestore(&priv->lock, flags);
498 }
499 
500 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port)
501 {
502 	struct oti6858_private *priv = usb_get_serial_port_data(port);
503 	struct usb_serial *serial = port->serial;
504 	struct oti6858_control_pkt *buf;
505 	unsigned long flags;
506 	int result;
507 
508 	usb_clear_halt(serial->dev, port->write_urb->pipe);
509 	usb_clear_halt(serial->dev, port->read_urb->pipe);
510 
511 	buf = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
512 	if (!buf)
513 		return -ENOMEM;
514 
515 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
516 				OTI6858_REQ_T_GET_STATUS,
517 				OTI6858_REQ_GET_STATUS,
518 				0, 0,
519 				buf, OTI6858_CTRL_PKT_SIZE,
520 				100);
521 	if (result != OTI6858_CTRL_PKT_SIZE) {
522 		/* assume default (after power-on reset) values */
523 		buf->divisor = cpu_to_le16(0x009c);	/* 38400 bps */
524 		buf->frame_fmt = 0x03;	/* 8N1 */
525 		buf->something = 0x43;
526 		buf->control = 0x4c;	/* DTR, RTS */
527 		buf->tx_status = 0x00;
528 		buf->pin_state = 0x5b;	/* RTS, CTS, DSR, DTR, RI, DCD */
529 		buf->rx_bytes_avail = 0x00;
530 	}
531 
532 	spin_lock_irqsave(&priv->lock, flags);
533 	memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
534 	priv->pending_setup.divisor = buf->divisor;
535 	priv->pending_setup.frame_fmt = buf->frame_fmt;
536 	priv->pending_setup.control = buf->control;
537 	spin_unlock_irqrestore(&priv->lock, flags);
538 	kfree(buf);
539 
540 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
541 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
542 	if (result != 0) {
543 		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
544 			__func__, result);
545 		oti6858_close(port);
546 		return result;
547 	}
548 
549 	/* setup termios */
550 	if (tty)
551 		oti6858_set_termios(tty, port, NULL);
552 
553 	return 0;
554 }
555 
556 static void oti6858_close(struct usb_serial_port *port)
557 {
558 	struct oti6858_private *priv = usb_get_serial_port_data(port);
559 	unsigned long flags;
560 
561 	spin_lock_irqsave(&port->lock, flags);
562 	/* clear out any remaining data in the buffer */
563 	kfifo_reset_out(&port->write_fifo);
564 	spin_unlock_irqrestore(&port->lock, flags);
565 
566 	dev_dbg(&port->dev, "%s(): after buf_clear()\n", __func__);
567 
568 	/* cancel scheduled setup */
569 	cancel_delayed_work_sync(&priv->delayed_setup_work);
570 	cancel_delayed_work_sync(&priv->delayed_write_work);
571 
572 	/* shutdown our urbs */
573 	dev_dbg(&port->dev, "%s(): shutting down urbs\n", __func__);
574 	usb_kill_urb(port->write_urb);
575 	usb_kill_urb(port->read_urb);
576 	usb_kill_urb(port->interrupt_in_urb);
577 }
578 
579 static int oti6858_tiocmset(struct tty_struct *tty,
580 				unsigned int set, unsigned int clear)
581 {
582 	struct usb_serial_port *port = tty->driver_data;
583 	struct oti6858_private *priv = usb_get_serial_port_data(port);
584 	unsigned long flags;
585 	u8 control;
586 
587 	dev_dbg(&port->dev, "%s(set = 0x%08x, clear = 0x%08x)\n",
588 		__func__, set, clear);
589 
590 	/* FIXME: check if this is correct (active high/low) */
591 	spin_lock_irqsave(&priv->lock, flags);
592 	control = priv->pending_setup.control;
593 	if ((set & TIOCM_RTS) != 0)
594 		control |= CONTROL_RTS_HIGH;
595 	if ((set & TIOCM_DTR) != 0)
596 		control |= CONTROL_DTR_HIGH;
597 	if ((clear & TIOCM_RTS) != 0)
598 		control &= ~CONTROL_RTS_HIGH;
599 	if ((clear & TIOCM_DTR) != 0)
600 		control &= ~CONTROL_DTR_HIGH;
601 
602 	if (control != priv->pending_setup.control)
603 		priv->pending_setup.control = control;
604 
605 	spin_unlock_irqrestore(&priv->lock, flags);
606 	return 0;
607 }
608 
609 static int oti6858_tiocmget(struct tty_struct *tty)
610 {
611 	struct usb_serial_port *port = tty->driver_data;
612 	struct oti6858_private *priv = usb_get_serial_port_data(port);
613 	unsigned long flags;
614 	unsigned pin_state;
615 	unsigned result = 0;
616 
617 	spin_lock_irqsave(&priv->lock, flags);
618 	pin_state = priv->status.pin_state & PIN_MASK;
619 	spin_unlock_irqrestore(&priv->lock, flags);
620 
621 	/* FIXME: check if this is correct (active high/low) */
622 	if ((pin_state & PIN_RTS) != 0)
623 		result |= TIOCM_RTS;
624 	if ((pin_state & PIN_CTS) != 0)
625 		result |= TIOCM_CTS;
626 	if ((pin_state & PIN_DSR) != 0)
627 		result |= TIOCM_DSR;
628 	if ((pin_state & PIN_DTR) != 0)
629 		result |= TIOCM_DTR;
630 	if ((pin_state & PIN_RI) != 0)
631 		result |= TIOCM_RI;
632 	if ((pin_state & PIN_DCD) != 0)
633 		result |= TIOCM_CD;
634 
635 	dev_dbg(&port->dev, "%s() = 0x%08x\n", __func__, result);
636 
637 	return result;
638 }
639 
640 static void oti6858_read_int_callback(struct urb *urb)
641 {
642 	struct usb_serial_port *port =  urb->context;
643 	struct oti6858_private *priv = usb_get_serial_port_data(port);
644 	int transient = 0, can_recv = 0, resubmit = 1;
645 	int status = urb->status;
646 
647 	switch (status) {
648 	case 0:
649 		/* success */
650 		break;
651 	case -ECONNRESET:
652 	case -ENOENT:
653 	case -ESHUTDOWN:
654 		/* this urb is terminated, clean up */
655 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n",
656 			__func__, status);
657 		return;
658 	default:
659 		dev_dbg(&urb->dev->dev, "%s(): nonzero urb status received: %d\n",
660 			__func__, status);
661 		break;
662 	}
663 
664 	if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
665 		struct oti6858_control_pkt *xs = urb->transfer_buffer;
666 		unsigned long flags;
667 
668 		spin_lock_irqsave(&priv->lock, flags);
669 
670 		if (!priv->transient) {
671 			if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
672 				if (xs->rx_bytes_avail == 0) {
673 					priv->transient = 4;
674 					priv->setup_done = 0;
675 					resubmit = 0;
676 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
677 					schedule_delayed_work(&priv->delayed_setup_work, 0);
678 				}
679 			}
680 		} else {
681 			if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
682 				priv->transient = 0;
683 			} else if (!priv->setup_done) {
684 				resubmit = 0;
685 			} else if (--priv->transient == 0) {
686 				if (xs->rx_bytes_avail == 0) {
687 					priv->transient = 4;
688 					priv->setup_done = 0;
689 					resubmit = 0;
690 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
691 					schedule_delayed_work(&priv->delayed_setup_work, 0);
692 				}
693 			}
694 		}
695 
696 		if (!priv->transient) {
697 			u8 delta = xs->pin_state ^ priv->status.pin_state;
698 
699 			if (delta & PIN_MSR_MASK) {
700 				if (delta & PIN_CTS)
701 					port->icount.cts++;
702 				if (delta & PIN_DSR)
703 					port->icount.dsr++;
704 				if (delta & PIN_RI)
705 					port->icount.rng++;
706 				if (delta & PIN_DCD)
707 					port->icount.dcd++;
708 
709 				wake_up_interruptible(&port->port.delta_msr_wait);
710 			}
711 
712 			memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
713 		}
714 
715 		if (!priv->transient && xs->rx_bytes_avail != 0) {
716 			can_recv = xs->rx_bytes_avail;
717 			priv->flags.read_urb_in_use = 1;
718 		}
719 
720 		transient = priv->transient;
721 		spin_unlock_irqrestore(&priv->lock, flags);
722 	}
723 
724 	if (can_recv) {
725 		int result;
726 
727 		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
728 		if (result != 0) {
729 			priv->flags.read_urb_in_use = 0;
730 			dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
731 					" error %d\n", __func__, result);
732 		} else {
733 			resubmit = 0;
734 		}
735 	} else if (!transient) {
736 		unsigned long flags;
737 		int count;
738 
739 		spin_lock_irqsave(&port->lock, flags);
740 		count = kfifo_len(&port->write_fifo);
741 		spin_unlock_irqrestore(&port->lock, flags);
742 
743 		spin_lock_irqsave(&priv->lock, flags);
744 		if (priv->flags.write_urb_in_use == 0 && count != 0) {
745 			schedule_delayed_work(&priv->delayed_write_work, 0);
746 			resubmit = 0;
747 		}
748 		spin_unlock_irqrestore(&priv->lock, flags);
749 	}
750 
751 	if (resubmit) {
752 		int result;
753 
754 /*		dev_dbg(&urb->dev->dev, "%s(): submitting interrupt urb\n", __func__); */
755 		result = usb_submit_urb(urb, GFP_ATOMIC);
756 		if (result != 0) {
757 			dev_err(&urb->dev->dev,
758 					"%s(): usb_submit_urb() failed with"
759 					" error %d\n", __func__, result);
760 		}
761 	}
762 }
763 
764 static void oti6858_read_bulk_callback(struct urb *urb)
765 {
766 	struct usb_serial_port *port =  urb->context;
767 	struct oti6858_private *priv = usb_get_serial_port_data(port);
768 	unsigned char *data = urb->transfer_buffer;
769 	unsigned long flags;
770 	int status = urb->status;
771 	int result;
772 
773 	spin_lock_irqsave(&priv->lock, flags);
774 	priv->flags.read_urb_in_use = 0;
775 	spin_unlock_irqrestore(&priv->lock, flags);
776 
777 	if (status != 0) {
778 		dev_dbg(&urb->dev->dev, "%s(): unable to handle the error, exiting\n", __func__);
779 		return;
780 	}
781 
782 	if (urb->actual_length > 0) {
783 		tty_insert_flip_string(&port->port, data, urb->actual_length);
784 		tty_flip_buffer_push(&port->port);
785 	}
786 
787 	/* schedule the interrupt urb */
788 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
789 	if (result != 0 && result != -EPERM) {
790 		dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
791 				" error %d\n", __func__, result);
792 	}
793 }
794 
795 static void oti6858_write_bulk_callback(struct urb *urb)
796 {
797 	struct usb_serial_port *port =  urb->context;
798 	struct oti6858_private *priv = usb_get_serial_port_data(port);
799 	int status = urb->status;
800 	int result;
801 
802 	switch (status) {
803 	case 0:
804 		/* success */
805 		break;
806 	case -ECONNRESET:
807 	case -ENOENT:
808 	case -ESHUTDOWN:
809 		/* this urb is terminated, clean up */
810 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n", __func__, status);
811 		priv->flags.write_urb_in_use = 0;
812 		return;
813 	default:
814 		/* error in the urb, so we have to resubmit it */
815 		dev_dbg(&urb->dev->dev, "%s(): nonzero write bulk status received: %d\n", __func__, status);
816 		dev_dbg(&urb->dev->dev, "%s(): overflow in write\n", __func__);
817 
818 		port->write_urb->transfer_buffer_length = 1;
819 		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
820 		if (result) {
821 			dev_err_console(port, "%s(): usb_submit_urb() failed,"
822 					" error %d\n", __func__, result);
823 		} else {
824 			return;
825 		}
826 	}
827 
828 	priv->flags.write_urb_in_use = 0;
829 
830 	/* schedule the interrupt urb if we are still open */
831 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
832 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
833 	if (result != 0) {
834 		dev_err(&port->dev, "%s(): failed submitting int urb,"
835 					" error %d\n", __func__, result);
836 	}
837 }
838 
839 module_usb_serial_driver(serial_drivers, id_table);
840 
841 MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
842 MODULE_AUTHOR(OTI6858_AUTHOR);
843 MODULE_LICENSE("GPL v2");
844