1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 *  Digi AccelePort USB-4 and USB-2 Serial Converters
4 *
5 *  Copyright 2000 by Digi International
6 *
7 *  Shamelessly based on Brian Warner's keyspan_pda.c and Greg Kroah-Hartman's
8 *  usb-serial driver.
9 *
10 *  Peter Berger (pberger@brimson.com)
11 *  Al Borchers (borchers@steinerpoint.com)
12 */
13 
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17 #include <linux/tty.h>
18 #include <linux/tty_driver.h>
19 #include <linux/tty_flip.h>
20 #include <linux/module.h>
21 #include <linux/spinlock.h>
22 #include <linux/workqueue.h>
23 #include <linux/uaccess.h>
24 #include <linux/usb.h>
25 #include <linux/wait.h>
26 #include <linux/sched/signal.h>
27 #include <linux/usb/serial.h>
28 
29 /* Defines */
30 
31 #define DRIVER_AUTHOR "Peter Berger <pberger@brimson.com>, Al Borchers <borchers@steinerpoint.com>"
32 #define DRIVER_DESC "Digi AccelePort USB-2/USB-4 Serial Converter driver"
33 
34 /* port output buffer length -- must be <= transfer buffer length - 2 */
35 /* so we can be sure to send the full buffer in one urb */
36 #define DIGI_OUT_BUF_SIZE		8
37 
38 /* port input buffer length -- must be >= transfer buffer length - 3 */
39 /* so we can be sure to hold at least one full buffer from one urb */
40 #define DIGI_IN_BUF_SIZE		64
41 
42 /* retry timeout while sleeping */
43 #define DIGI_RETRY_TIMEOUT		(HZ/10)
44 
45 /* timeout while waiting for tty output to drain in close */
46 /* this delay is used twice in close, so the total delay could */
47 /* be twice this value */
48 #define DIGI_CLOSE_TIMEOUT		(5*HZ)
49 
50 
51 /* AccelePort USB Defines */
52 
53 /* ids */
54 #define DIGI_VENDOR_ID			0x05c5
55 #define DIGI_2_ID			0x0002	/* USB-2 */
56 #define DIGI_4_ID			0x0004	/* USB-4 */
57 
58 /* commands
59  * "INB": can be used on the in-band endpoint
60  * "OOB": can be used on the out-of-band endpoint
61  */
62 #define DIGI_CMD_SET_BAUD_RATE			0	/* INB, OOB */
63 #define DIGI_CMD_SET_WORD_SIZE			1	/* INB, OOB */
64 #define DIGI_CMD_SET_PARITY			2	/* INB, OOB */
65 #define DIGI_CMD_SET_STOP_BITS			3	/* INB, OOB */
66 #define DIGI_CMD_SET_INPUT_FLOW_CONTROL		4	/* INB, OOB */
67 #define DIGI_CMD_SET_OUTPUT_FLOW_CONTROL	5	/* INB, OOB */
68 #define DIGI_CMD_SET_DTR_SIGNAL			6	/* INB, OOB */
69 #define DIGI_CMD_SET_RTS_SIGNAL			7	/* INB, OOB */
70 #define DIGI_CMD_READ_INPUT_SIGNALS		8	/*      OOB */
71 #define DIGI_CMD_IFLUSH_FIFO			9	/*      OOB */
72 #define DIGI_CMD_RECEIVE_ENABLE			10	/* INB, OOB */
73 #define DIGI_CMD_BREAK_CONTROL			11	/* INB, OOB */
74 #define DIGI_CMD_LOCAL_LOOPBACK			12	/* INB, OOB */
75 #define DIGI_CMD_TRANSMIT_IDLE			13	/* INB, OOB */
76 #define DIGI_CMD_READ_UART_REGISTER		14	/*      OOB */
77 #define DIGI_CMD_WRITE_UART_REGISTER		15	/* INB, OOB */
78 #define DIGI_CMD_AND_UART_REGISTER		16	/* INB, OOB */
79 #define DIGI_CMD_OR_UART_REGISTER		17	/* INB, OOB */
80 #define DIGI_CMD_SEND_DATA			18	/* INB      */
81 #define DIGI_CMD_RECEIVE_DATA			19	/* INB      */
82 #define DIGI_CMD_RECEIVE_DISABLE		20	/* INB      */
83 #define DIGI_CMD_GET_PORT_TYPE			21	/*      OOB */
84 
85 /* baud rates */
86 #define DIGI_BAUD_50				0
87 #define DIGI_BAUD_75				1
88 #define DIGI_BAUD_110				2
89 #define DIGI_BAUD_150				3
90 #define DIGI_BAUD_200				4
91 #define DIGI_BAUD_300				5
92 #define DIGI_BAUD_600				6
93 #define DIGI_BAUD_1200				7
94 #define DIGI_BAUD_1800				8
95 #define DIGI_BAUD_2400				9
96 #define DIGI_BAUD_4800				10
97 #define DIGI_BAUD_7200				11
98 #define DIGI_BAUD_9600				12
99 #define DIGI_BAUD_14400				13
100 #define DIGI_BAUD_19200				14
101 #define DIGI_BAUD_28800				15
102 #define DIGI_BAUD_38400				16
103 #define DIGI_BAUD_57600				17
104 #define DIGI_BAUD_76800				18
105 #define DIGI_BAUD_115200			19
106 #define DIGI_BAUD_153600			20
107 #define DIGI_BAUD_230400			21
108 #define DIGI_BAUD_460800			22
109 
110 /* arguments */
111 #define DIGI_WORD_SIZE_5			0
112 #define DIGI_WORD_SIZE_6			1
113 #define DIGI_WORD_SIZE_7			2
114 #define DIGI_WORD_SIZE_8			3
115 
116 #define DIGI_PARITY_NONE			0
117 #define DIGI_PARITY_ODD				1
118 #define DIGI_PARITY_EVEN			2
119 #define DIGI_PARITY_MARK			3
120 #define DIGI_PARITY_SPACE			4
121 
122 #define DIGI_STOP_BITS_1			0
123 #define DIGI_STOP_BITS_2			1
124 
125 #define DIGI_INPUT_FLOW_CONTROL_XON_XOFF	1
126 #define DIGI_INPUT_FLOW_CONTROL_RTS		2
127 #define DIGI_INPUT_FLOW_CONTROL_DTR		4
128 
129 #define DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF	1
130 #define DIGI_OUTPUT_FLOW_CONTROL_CTS		2
131 #define DIGI_OUTPUT_FLOW_CONTROL_DSR		4
132 
133 #define DIGI_DTR_INACTIVE			0
134 #define DIGI_DTR_ACTIVE				1
135 #define DIGI_DTR_INPUT_FLOW_CONTROL		2
136 
137 #define DIGI_RTS_INACTIVE			0
138 #define DIGI_RTS_ACTIVE				1
139 #define DIGI_RTS_INPUT_FLOW_CONTROL		2
140 #define DIGI_RTS_TOGGLE				3
141 
142 #define DIGI_FLUSH_TX				1
143 #define DIGI_FLUSH_RX				2
144 #define DIGI_RESUME_TX				4 /* clears xoff condition */
145 
146 #define DIGI_TRANSMIT_NOT_IDLE			0
147 #define DIGI_TRANSMIT_IDLE			1
148 
149 #define DIGI_DISABLE				0
150 #define DIGI_ENABLE				1
151 
152 #define DIGI_DEASSERT				0
153 #define DIGI_ASSERT				1
154 
155 /* in band status codes */
156 #define DIGI_OVERRUN_ERROR			4
157 #define DIGI_PARITY_ERROR			8
158 #define DIGI_FRAMING_ERROR			16
159 #define DIGI_BREAK_ERROR			32
160 
161 /* out of band status */
162 #define DIGI_NO_ERROR				0
163 #define DIGI_BAD_FIRST_PARAMETER		1
164 #define DIGI_BAD_SECOND_PARAMETER		2
165 #define DIGI_INVALID_LINE			3
166 #define DIGI_INVALID_OPCODE			4
167 
168 /* input signals */
169 #define DIGI_READ_INPUT_SIGNALS_SLOT		1
170 #define DIGI_READ_INPUT_SIGNALS_ERR		2
171 #define DIGI_READ_INPUT_SIGNALS_BUSY		4
172 #define DIGI_READ_INPUT_SIGNALS_PE		8
173 #define DIGI_READ_INPUT_SIGNALS_CTS		16
174 #define DIGI_READ_INPUT_SIGNALS_DSR		32
175 #define DIGI_READ_INPUT_SIGNALS_RI		64
176 #define DIGI_READ_INPUT_SIGNALS_DCD		128
177 
178 
179 /* Structures */
180 
181 struct digi_serial {
182 	spinlock_t ds_serial_lock;
183 	struct usb_serial_port *ds_oob_port;	/* out-of-band port */
184 	int ds_oob_port_num;			/* index of out-of-band port */
185 	int ds_device_started;
186 };
187 
188 struct digi_port {
189 	spinlock_t dp_port_lock;
190 	int dp_port_num;
191 	int dp_out_buf_len;
192 	unsigned char dp_out_buf[DIGI_OUT_BUF_SIZE];
193 	int dp_write_urb_in_use;
194 	unsigned int dp_modem_signals;
195 	int dp_transmit_idle;
196 	wait_queue_head_t dp_transmit_idle_wait;
197 	int dp_throttled;
198 	int dp_throttle_restart;
199 	wait_queue_head_t dp_flush_wait;
200 	wait_queue_head_t dp_close_wait;	/* wait queue for close */
201 	struct work_struct dp_wakeup_work;
202 	struct usb_serial_port *dp_port;
203 };
204 
205 
206 /* Local Function Declarations */
207 
208 static void digi_wakeup_write_lock(struct work_struct *work);
209 static int digi_write_oob_command(struct usb_serial_port *port,
210 	unsigned char *buf, int count, int interruptible);
211 static int digi_write_inb_command(struct usb_serial_port *port,
212 	unsigned char *buf, int count, unsigned long timeout);
213 static int digi_set_modem_signals(struct usb_serial_port *port,
214 	unsigned int modem_signals, int interruptible);
215 static int digi_transmit_idle(struct usb_serial_port *port,
216 	unsigned long timeout);
217 static void digi_rx_throttle(struct tty_struct *tty);
218 static void digi_rx_unthrottle(struct tty_struct *tty);
219 static void digi_set_termios(struct tty_struct *tty,
220 		struct usb_serial_port *port, struct ktermios *old_termios);
221 static void digi_break_ctl(struct tty_struct *tty, int break_state);
222 static int digi_tiocmget(struct tty_struct *tty);
223 static int digi_tiocmset(struct tty_struct *tty, unsigned int set,
224 		unsigned int clear);
225 static int digi_write(struct tty_struct *tty, struct usb_serial_port *port,
226 		const unsigned char *buf, int count);
227 static void digi_write_bulk_callback(struct urb *urb);
228 static int digi_write_room(struct tty_struct *tty);
229 static int digi_chars_in_buffer(struct tty_struct *tty);
230 static int digi_open(struct tty_struct *tty, struct usb_serial_port *port);
231 static void digi_close(struct usb_serial_port *port);
232 static void digi_dtr_rts(struct usb_serial_port *port, int on);
233 static int digi_startup_device(struct usb_serial *serial);
234 static int digi_startup(struct usb_serial *serial);
235 static void digi_disconnect(struct usb_serial *serial);
236 static void digi_release(struct usb_serial *serial);
237 static int digi_port_probe(struct usb_serial_port *port);
238 static int digi_port_remove(struct usb_serial_port *port);
239 static void digi_read_bulk_callback(struct urb *urb);
240 static int digi_read_inb_callback(struct urb *urb);
241 static int digi_read_oob_callback(struct urb *urb);
242 
243 
244 static const struct usb_device_id id_table_combined[] = {
245 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_2_ID) },
246 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_4_ID) },
247 	{ }						/* Terminating entry */
248 };
249 
250 static const struct usb_device_id id_table_2[] = {
251 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_2_ID) },
252 	{ }						/* Terminating entry */
253 };
254 
255 static const struct usb_device_id id_table_4[] = {
256 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_4_ID) },
257 	{ }						/* Terminating entry */
258 };
259 
260 MODULE_DEVICE_TABLE(usb, id_table_combined);
261 
262 /* device info needed for the Digi serial converter */
263 
264 static struct usb_serial_driver digi_acceleport_2_device = {
265 	.driver = {
266 		.owner =		THIS_MODULE,
267 		.name =			"digi_2",
268 	},
269 	.description =			"Digi 2 port USB adapter",
270 	.id_table =			id_table_2,
271 	.num_ports =			3,
272 	.num_bulk_in =			4,
273 	.num_bulk_out =			4,
274 	.open =				digi_open,
275 	.close =			digi_close,
276 	.dtr_rts =			digi_dtr_rts,
277 	.write =			digi_write,
278 	.write_room =			digi_write_room,
279 	.write_bulk_callback = 		digi_write_bulk_callback,
280 	.read_bulk_callback =		digi_read_bulk_callback,
281 	.chars_in_buffer =		digi_chars_in_buffer,
282 	.throttle =			digi_rx_throttle,
283 	.unthrottle =			digi_rx_unthrottle,
284 	.set_termios =			digi_set_termios,
285 	.break_ctl =			digi_break_ctl,
286 	.tiocmget =			digi_tiocmget,
287 	.tiocmset =			digi_tiocmset,
288 	.attach =			digi_startup,
289 	.disconnect =			digi_disconnect,
290 	.release =			digi_release,
291 	.port_probe =			digi_port_probe,
292 	.port_remove =			digi_port_remove,
293 };
294 
295 static struct usb_serial_driver digi_acceleport_4_device = {
296 	.driver = {
297 		.owner =		THIS_MODULE,
298 		.name =			"digi_4",
299 	},
300 	.description =			"Digi 4 port USB adapter",
301 	.id_table =			id_table_4,
302 	.num_ports =			4,
303 	.num_bulk_in =			5,
304 	.num_bulk_out =			5,
305 	.open =				digi_open,
306 	.close =			digi_close,
307 	.write =			digi_write,
308 	.write_room =			digi_write_room,
309 	.write_bulk_callback = 		digi_write_bulk_callback,
310 	.read_bulk_callback =		digi_read_bulk_callback,
311 	.chars_in_buffer =		digi_chars_in_buffer,
312 	.throttle =			digi_rx_throttle,
313 	.unthrottle =			digi_rx_unthrottle,
314 	.set_termios =			digi_set_termios,
315 	.break_ctl =			digi_break_ctl,
316 	.tiocmget =			digi_tiocmget,
317 	.tiocmset =			digi_tiocmset,
318 	.attach =			digi_startup,
319 	.disconnect =			digi_disconnect,
320 	.release =			digi_release,
321 	.port_probe =			digi_port_probe,
322 	.port_remove =			digi_port_remove,
323 };
324 
325 static struct usb_serial_driver * const serial_drivers[] = {
326 	&digi_acceleport_2_device, &digi_acceleport_4_device, NULL
327 };
328 
329 /* Functions */
330 
331 /*
332  *  Cond Wait Interruptible Timeout Irqrestore
333  *
334  *  Do spin_unlock_irqrestore and interruptible_sleep_on_timeout
335  *  so that wake ups are not lost if they occur between the unlock
336  *  and the sleep.  In other words, spin_unlock_irqrestore and
337  *  interruptible_sleep_on_timeout are "atomic" with respect to
338  *  wake ups.  This is used to implement condition variables.
339  *
340  *  interruptible_sleep_on_timeout is deprecated and has been replaced
341  *  with the equivalent code.
342  */
343 
344 static long cond_wait_interruptible_timeout_irqrestore(
345 	wait_queue_head_t *q, long timeout,
346 	spinlock_t *lock, unsigned long flags)
347 __releases(lock)
348 {
349 	DEFINE_WAIT(wait);
350 
351 	prepare_to_wait(q, &wait, TASK_INTERRUPTIBLE);
352 	spin_unlock_irqrestore(lock, flags);
353 	timeout = schedule_timeout(timeout);
354 	finish_wait(q, &wait);
355 
356 	return timeout;
357 }
358 
359 
360 /*
361  *  Digi Wakeup Write
362  *
363  *  Wake up port, line discipline, and tty processes sleeping
364  *  on writes.
365  */
366 
367 static void digi_wakeup_write_lock(struct work_struct *work)
368 {
369 	struct digi_port *priv =
370 			container_of(work, struct digi_port, dp_wakeup_work);
371 	struct usb_serial_port *port = priv->dp_port;
372 	unsigned long flags;
373 
374 	spin_lock_irqsave(&priv->dp_port_lock, flags);
375 	tty_port_tty_wakeup(&port->port);
376 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
377 }
378 
379 /*
380  *  Digi Write OOB Command
381  *
382  *  Write commands on the out of band port.  Commands are 4
383  *  bytes each, multiple commands can be sent at once, and
384  *  no command will be split across USB packets.  Returns 0
385  *  if successful, -EINTR if interrupted while sleeping and
386  *  the interruptible flag is true, or a negative error
387  *  returned by usb_submit_urb.
388  */
389 
390 static int digi_write_oob_command(struct usb_serial_port *port,
391 	unsigned char *buf, int count, int interruptible)
392 {
393 	int ret = 0;
394 	int len;
395 	struct usb_serial_port *oob_port = (struct usb_serial_port *)((struct digi_serial *)(usb_get_serial_data(port->serial)))->ds_oob_port;
396 	struct digi_port *oob_priv = usb_get_serial_port_data(oob_port);
397 	unsigned long flags = 0;
398 
399 	dev_dbg(&port->dev,
400 		"digi_write_oob_command: TOP: port=%d, count=%d\n",
401 		oob_priv->dp_port_num, count);
402 
403 	spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
404 	while (count > 0) {
405 		while (oob_priv->dp_write_urb_in_use) {
406 			cond_wait_interruptible_timeout_irqrestore(
407 				&oob_port->write_wait, DIGI_RETRY_TIMEOUT,
408 				&oob_priv->dp_port_lock, flags);
409 			if (interruptible && signal_pending(current))
410 				return -EINTR;
411 			spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
412 		}
413 
414 		/* len must be a multiple of 4, so commands are not split */
415 		len = min(count, oob_port->bulk_out_size);
416 		if (len > 4)
417 			len &= ~3;
418 		memcpy(oob_port->write_urb->transfer_buffer, buf, len);
419 		oob_port->write_urb->transfer_buffer_length = len;
420 		ret = usb_submit_urb(oob_port->write_urb, GFP_ATOMIC);
421 		if (ret == 0) {
422 			oob_priv->dp_write_urb_in_use = 1;
423 			count -= len;
424 			buf += len;
425 		}
426 	}
427 	spin_unlock_irqrestore(&oob_priv->dp_port_lock, flags);
428 	if (ret)
429 		dev_err(&port->dev, "%s: usb_submit_urb failed, ret=%d\n",
430 			__func__, ret);
431 	return ret;
432 
433 }
434 
435 
436 /*
437  *  Digi Write In Band Command
438  *
439  *  Write commands on the given port.  Commands are 4
440  *  bytes each, multiple commands can be sent at once, and
441  *  no command will be split across USB packets.  If timeout
442  *  is non-zero, write in band command will return after
443  *  waiting unsuccessfully for the URB status to clear for
444  *  timeout ticks.  Returns 0 if successful, or a negative
445  *  error returned by digi_write.
446  */
447 
448 static int digi_write_inb_command(struct usb_serial_port *port,
449 	unsigned char *buf, int count, unsigned long timeout)
450 {
451 	int ret = 0;
452 	int len;
453 	struct digi_port *priv = usb_get_serial_port_data(port);
454 	unsigned char *data = port->write_urb->transfer_buffer;
455 	unsigned long flags = 0;
456 
457 	dev_dbg(&port->dev, "digi_write_inb_command: TOP: port=%d, count=%d\n",
458 		priv->dp_port_num, count);
459 
460 	if (timeout)
461 		timeout += jiffies;
462 	else
463 		timeout = ULONG_MAX;
464 
465 	spin_lock_irqsave(&priv->dp_port_lock, flags);
466 	while (count > 0 && ret == 0) {
467 		while (priv->dp_write_urb_in_use &&
468 		       time_before(jiffies, timeout)) {
469 			cond_wait_interruptible_timeout_irqrestore(
470 				&port->write_wait, DIGI_RETRY_TIMEOUT,
471 				&priv->dp_port_lock, flags);
472 			if (signal_pending(current))
473 				return -EINTR;
474 			spin_lock_irqsave(&priv->dp_port_lock, flags);
475 		}
476 
477 		/* len must be a multiple of 4 and small enough to */
478 		/* guarantee the write will send buffered data first, */
479 		/* so commands are in order with data and not split */
480 		len = min(count, port->bulk_out_size-2-priv->dp_out_buf_len);
481 		if (len > 4)
482 			len &= ~3;
483 
484 		/* write any buffered data first */
485 		if (priv->dp_out_buf_len > 0) {
486 			data[0] = DIGI_CMD_SEND_DATA;
487 			data[1] = priv->dp_out_buf_len;
488 			memcpy(data + 2, priv->dp_out_buf,
489 				priv->dp_out_buf_len);
490 			memcpy(data + 2 + priv->dp_out_buf_len, buf, len);
491 			port->write_urb->transfer_buffer_length
492 				= priv->dp_out_buf_len + 2 + len;
493 		} else {
494 			memcpy(data, buf, len);
495 			port->write_urb->transfer_buffer_length = len;
496 		}
497 
498 		ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
499 		if (ret == 0) {
500 			priv->dp_write_urb_in_use = 1;
501 			priv->dp_out_buf_len = 0;
502 			count -= len;
503 			buf += len;
504 		}
505 
506 	}
507 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
508 
509 	if (ret)
510 		dev_err(&port->dev,
511 			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
512 			__func__, ret, priv->dp_port_num);
513 	return ret;
514 }
515 
516 
517 /*
518  *  Digi Set Modem Signals
519  *
520  *  Sets or clears DTR and RTS on the port, according to the
521  *  modem_signals argument.  Use TIOCM_DTR and TIOCM_RTS flags
522  *  for the modem_signals argument.  Returns 0 if successful,
523  *  -EINTR if interrupted while sleeping, or a non-zero error
524  *  returned by usb_submit_urb.
525  */
526 
527 static int digi_set_modem_signals(struct usb_serial_port *port,
528 	unsigned int modem_signals, int interruptible)
529 {
530 
531 	int ret;
532 	struct digi_port *port_priv = usb_get_serial_port_data(port);
533 	struct usb_serial_port *oob_port = (struct usb_serial_port *) ((struct digi_serial *)(usb_get_serial_data(port->serial)))->ds_oob_port;
534 	struct digi_port *oob_priv = usb_get_serial_port_data(oob_port);
535 	unsigned char *data = oob_port->write_urb->transfer_buffer;
536 	unsigned long flags = 0;
537 
538 
539 	dev_dbg(&port->dev,
540 		"digi_set_modem_signals: TOP: port=%d, modem_signals=0x%x\n",
541 		port_priv->dp_port_num, modem_signals);
542 
543 	spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
544 	spin_lock(&port_priv->dp_port_lock);
545 
546 	while (oob_priv->dp_write_urb_in_use) {
547 		spin_unlock(&port_priv->dp_port_lock);
548 		cond_wait_interruptible_timeout_irqrestore(
549 			&oob_port->write_wait, DIGI_RETRY_TIMEOUT,
550 			&oob_priv->dp_port_lock, flags);
551 		if (interruptible && signal_pending(current))
552 			return -EINTR;
553 		spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
554 		spin_lock(&port_priv->dp_port_lock);
555 	}
556 	data[0] = DIGI_CMD_SET_DTR_SIGNAL;
557 	data[1] = port_priv->dp_port_num;
558 	data[2] = (modem_signals & TIOCM_DTR) ?
559 					DIGI_DTR_ACTIVE : DIGI_DTR_INACTIVE;
560 	data[3] = 0;
561 	data[4] = DIGI_CMD_SET_RTS_SIGNAL;
562 	data[5] = port_priv->dp_port_num;
563 	data[6] = (modem_signals & TIOCM_RTS) ?
564 					DIGI_RTS_ACTIVE : DIGI_RTS_INACTIVE;
565 	data[7] = 0;
566 
567 	oob_port->write_urb->transfer_buffer_length = 8;
568 
569 	ret = usb_submit_urb(oob_port->write_urb, GFP_ATOMIC);
570 	if (ret == 0) {
571 		oob_priv->dp_write_urb_in_use = 1;
572 		port_priv->dp_modem_signals =
573 			(port_priv->dp_modem_signals&~(TIOCM_DTR|TIOCM_RTS))
574 			| (modem_signals&(TIOCM_DTR|TIOCM_RTS));
575 	}
576 	spin_unlock(&port_priv->dp_port_lock);
577 	spin_unlock_irqrestore(&oob_priv->dp_port_lock, flags);
578 	if (ret)
579 		dev_err(&port->dev, "%s: usb_submit_urb failed, ret=%d\n",
580 			__func__, ret);
581 	return ret;
582 }
583 
584 /*
585  *  Digi Transmit Idle
586  *
587  *  Digi transmit idle waits, up to timeout ticks, for the transmitter
588  *  to go idle.  It returns 0 if successful or a negative error.
589  *
590  *  There are race conditions here if more than one process is calling
591  *  digi_transmit_idle on the same port at the same time.  However, this
592  *  is only called from close, and only one process can be in close on a
593  *  port at a time, so its ok.
594  */
595 
596 static int digi_transmit_idle(struct usb_serial_port *port,
597 	unsigned long timeout)
598 {
599 	int ret;
600 	unsigned char buf[2];
601 	struct digi_port *priv = usb_get_serial_port_data(port);
602 	unsigned long flags = 0;
603 
604 	spin_lock_irqsave(&priv->dp_port_lock, flags);
605 	priv->dp_transmit_idle = 0;
606 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
607 
608 	buf[0] = DIGI_CMD_TRANSMIT_IDLE;
609 	buf[1] = 0;
610 
611 	timeout += jiffies;
612 
613 	ret = digi_write_inb_command(port, buf, 2, timeout - jiffies);
614 	if (ret != 0)
615 		return ret;
616 
617 	spin_lock_irqsave(&priv->dp_port_lock, flags);
618 
619 	while (time_before(jiffies, timeout) && !priv->dp_transmit_idle) {
620 		cond_wait_interruptible_timeout_irqrestore(
621 			&priv->dp_transmit_idle_wait, DIGI_RETRY_TIMEOUT,
622 			&priv->dp_port_lock, flags);
623 		if (signal_pending(current))
624 			return -EINTR;
625 		spin_lock_irqsave(&priv->dp_port_lock, flags);
626 	}
627 	priv->dp_transmit_idle = 0;
628 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
629 	return 0;
630 
631 }
632 
633 
634 static void digi_rx_throttle(struct tty_struct *tty)
635 {
636 	unsigned long flags;
637 	struct usb_serial_port *port = tty->driver_data;
638 	struct digi_port *priv = usb_get_serial_port_data(port);
639 
640 	/* stop receiving characters by not resubmitting the read urb */
641 	spin_lock_irqsave(&priv->dp_port_lock, flags);
642 	priv->dp_throttled = 1;
643 	priv->dp_throttle_restart = 0;
644 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
645 }
646 
647 
648 static void digi_rx_unthrottle(struct tty_struct *tty)
649 {
650 	int ret = 0;
651 	unsigned long flags;
652 	struct usb_serial_port *port = tty->driver_data;
653 	struct digi_port *priv = usb_get_serial_port_data(port);
654 
655 	spin_lock_irqsave(&priv->dp_port_lock, flags);
656 
657 	/* restart read chain */
658 	if (priv->dp_throttle_restart)
659 		ret = usb_submit_urb(port->read_urb, GFP_ATOMIC);
660 
661 	/* turn throttle off */
662 	priv->dp_throttled = 0;
663 	priv->dp_throttle_restart = 0;
664 
665 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
666 
667 	if (ret)
668 		dev_err(&port->dev,
669 			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
670 			__func__, ret, priv->dp_port_num);
671 }
672 
673 
674 static void digi_set_termios(struct tty_struct *tty,
675 		struct usb_serial_port *port, struct ktermios *old_termios)
676 {
677 	struct digi_port *priv = usb_get_serial_port_data(port);
678 	struct device *dev = &port->dev;
679 	unsigned int iflag = tty->termios.c_iflag;
680 	unsigned int cflag = tty->termios.c_cflag;
681 	unsigned int old_iflag = old_termios->c_iflag;
682 	unsigned int old_cflag = old_termios->c_cflag;
683 	unsigned char buf[32];
684 	unsigned int modem_signals;
685 	int arg, ret;
686 	int i = 0;
687 	speed_t baud;
688 
689 	dev_dbg(dev,
690 		"digi_set_termios: TOP: port=%d, iflag=0x%x, old_iflag=0x%x, cflag=0x%x, old_cflag=0x%x\n",
691 		priv->dp_port_num, iflag, old_iflag, cflag, old_cflag);
692 
693 	/* set baud rate */
694 	baud = tty_get_baud_rate(tty);
695 	if (baud != tty_termios_baud_rate(old_termios)) {
696 		arg = -1;
697 
698 		/* reassert DTR and (maybe) RTS on transition from B0 */
699 		if ((old_cflag & CBAUD) == B0) {
700 			/* don't set RTS if using hardware flow control */
701 			/* and throttling input */
702 			modem_signals = TIOCM_DTR;
703 			if (!C_CRTSCTS(tty) || !tty_throttled(tty))
704 				modem_signals |= TIOCM_RTS;
705 			digi_set_modem_signals(port, modem_signals, 1);
706 		}
707 		switch (baud) {
708 		/* drop DTR and RTS on transition to B0 */
709 		case 0: digi_set_modem_signals(port, 0, 1); break;
710 		case 50: arg = DIGI_BAUD_50; break;
711 		case 75: arg = DIGI_BAUD_75; break;
712 		case 110: arg = DIGI_BAUD_110; break;
713 		case 150: arg = DIGI_BAUD_150; break;
714 		case 200: arg = DIGI_BAUD_200; break;
715 		case 300: arg = DIGI_BAUD_300; break;
716 		case 600: arg = DIGI_BAUD_600; break;
717 		case 1200: arg = DIGI_BAUD_1200; break;
718 		case 1800: arg = DIGI_BAUD_1800; break;
719 		case 2400: arg = DIGI_BAUD_2400; break;
720 		case 4800: arg = DIGI_BAUD_4800; break;
721 		case 9600: arg = DIGI_BAUD_9600; break;
722 		case 19200: arg = DIGI_BAUD_19200; break;
723 		case 38400: arg = DIGI_BAUD_38400; break;
724 		case 57600: arg = DIGI_BAUD_57600; break;
725 		case 115200: arg = DIGI_BAUD_115200; break;
726 		case 230400: arg = DIGI_BAUD_230400; break;
727 		case 460800: arg = DIGI_BAUD_460800; break;
728 		default:
729 			arg = DIGI_BAUD_9600;
730 			baud = 9600;
731 			break;
732 		}
733 		if (arg != -1) {
734 			buf[i++] = DIGI_CMD_SET_BAUD_RATE;
735 			buf[i++] = priv->dp_port_num;
736 			buf[i++] = arg;
737 			buf[i++] = 0;
738 		}
739 	}
740 	/* set parity */
741 	tty->termios.c_cflag &= ~CMSPAR;
742 
743 	if ((cflag&(PARENB|PARODD)) != (old_cflag&(PARENB|PARODD))) {
744 		if (cflag&PARENB) {
745 			if (cflag&PARODD)
746 				arg = DIGI_PARITY_ODD;
747 			else
748 				arg = DIGI_PARITY_EVEN;
749 		} else {
750 			arg = DIGI_PARITY_NONE;
751 		}
752 		buf[i++] = DIGI_CMD_SET_PARITY;
753 		buf[i++] = priv->dp_port_num;
754 		buf[i++] = arg;
755 		buf[i++] = 0;
756 	}
757 	/* set word size */
758 	if ((cflag&CSIZE) != (old_cflag&CSIZE)) {
759 		arg = -1;
760 		switch (cflag&CSIZE) {
761 		case CS5: arg = DIGI_WORD_SIZE_5; break;
762 		case CS6: arg = DIGI_WORD_SIZE_6; break;
763 		case CS7: arg = DIGI_WORD_SIZE_7; break;
764 		case CS8: arg = DIGI_WORD_SIZE_8; break;
765 		default:
766 			dev_dbg(dev,
767 				"digi_set_termios: can't handle word size %d\n",
768 				(cflag&CSIZE));
769 			break;
770 		}
771 
772 		if (arg != -1) {
773 			buf[i++] = DIGI_CMD_SET_WORD_SIZE;
774 			buf[i++] = priv->dp_port_num;
775 			buf[i++] = arg;
776 			buf[i++] = 0;
777 		}
778 
779 	}
780 
781 	/* set stop bits */
782 	if ((cflag&CSTOPB) != (old_cflag&CSTOPB)) {
783 
784 		if ((cflag&CSTOPB))
785 			arg = DIGI_STOP_BITS_2;
786 		else
787 			arg = DIGI_STOP_BITS_1;
788 
789 		buf[i++] = DIGI_CMD_SET_STOP_BITS;
790 		buf[i++] = priv->dp_port_num;
791 		buf[i++] = arg;
792 		buf[i++] = 0;
793 
794 	}
795 
796 	/* set input flow control */
797 	if ((iflag&IXOFF) != (old_iflag&IXOFF)
798 	    || (cflag&CRTSCTS) != (old_cflag&CRTSCTS)) {
799 		arg = 0;
800 		if (iflag&IXOFF)
801 			arg |= DIGI_INPUT_FLOW_CONTROL_XON_XOFF;
802 		else
803 			arg &= ~DIGI_INPUT_FLOW_CONTROL_XON_XOFF;
804 
805 		if (cflag&CRTSCTS) {
806 			arg |= DIGI_INPUT_FLOW_CONTROL_RTS;
807 
808 			/* On USB-4 it is necessary to assert RTS prior */
809 			/* to selecting RTS input flow control.  */
810 			buf[i++] = DIGI_CMD_SET_RTS_SIGNAL;
811 			buf[i++] = priv->dp_port_num;
812 			buf[i++] = DIGI_RTS_ACTIVE;
813 			buf[i++] = 0;
814 
815 		} else {
816 			arg &= ~DIGI_INPUT_FLOW_CONTROL_RTS;
817 		}
818 		buf[i++] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
819 		buf[i++] = priv->dp_port_num;
820 		buf[i++] = arg;
821 		buf[i++] = 0;
822 	}
823 
824 	/* set output flow control */
825 	if ((iflag & IXON) != (old_iflag & IXON)
826 	    || (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
827 		arg = 0;
828 		if (iflag & IXON)
829 			arg |= DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF;
830 		else
831 			arg &= ~DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF;
832 
833 		if (cflag & CRTSCTS) {
834 			arg |= DIGI_OUTPUT_FLOW_CONTROL_CTS;
835 		} else {
836 			arg &= ~DIGI_OUTPUT_FLOW_CONTROL_CTS;
837 		}
838 
839 		buf[i++] = DIGI_CMD_SET_OUTPUT_FLOW_CONTROL;
840 		buf[i++] = priv->dp_port_num;
841 		buf[i++] = arg;
842 		buf[i++] = 0;
843 	}
844 
845 	/* set receive enable/disable */
846 	if ((cflag & CREAD) != (old_cflag & CREAD)) {
847 		if (cflag & CREAD)
848 			arg = DIGI_ENABLE;
849 		else
850 			arg = DIGI_DISABLE;
851 
852 		buf[i++] = DIGI_CMD_RECEIVE_ENABLE;
853 		buf[i++] = priv->dp_port_num;
854 		buf[i++] = arg;
855 		buf[i++] = 0;
856 	}
857 	ret = digi_write_oob_command(port, buf, i, 1);
858 	if (ret != 0)
859 		dev_dbg(dev, "digi_set_termios: write oob failed, ret=%d\n", ret);
860 	tty_encode_baud_rate(tty, baud, baud);
861 }
862 
863 
864 static void digi_break_ctl(struct tty_struct *tty, int break_state)
865 {
866 	struct usb_serial_port *port = tty->driver_data;
867 	unsigned char buf[4];
868 
869 	buf[0] = DIGI_CMD_BREAK_CONTROL;
870 	buf[1] = 2;				/* length */
871 	buf[2] = break_state ? 1 : 0;
872 	buf[3] = 0;				/* pad */
873 	digi_write_inb_command(port, buf, 4, 0);
874 }
875 
876 
877 static int digi_tiocmget(struct tty_struct *tty)
878 {
879 	struct usb_serial_port *port = tty->driver_data;
880 	struct digi_port *priv = usb_get_serial_port_data(port);
881 	unsigned int val;
882 	unsigned long flags;
883 
884 	spin_lock_irqsave(&priv->dp_port_lock, flags);
885 	val = priv->dp_modem_signals;
886 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
887 	return val;
888 }
889 
890 
891 static int digi_tiocmset(struct tty_struct *tty,
892 					unsigned int set, unsigned int clear)
893 {
894 	struct usb_serial_port *port = tty->driver_data;
895 	struct digi_port *priv = usb_get_serial_port_data(port);
896 	unsigned int val;
897 	unsigned long flags;
898 
899 	spin_lock_irqsave(&priv->dp_port_lock, flags);
900 	val = (priv->dp_modem_signals & ~clear) | set;
901 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
902 	return digi_set_modem_signals(port, val, 1);
903 }
904 
905 
906 static int digi_write(struct tty_struct *tty, struct usb_serial_port *port,
907 					const unsigned char *buf, int count)
908 {
909 
910 	int ret, data_len, new_len;
911 	struct digi_port *priv = usb_get_serial_port_data(port);
912 	unsigned char *data = port->write_urb->transfer_buffer;
913 	unsigned long flags = 0;
914 
915 	dev_dbg(&port->dev,
916 		"digi_write: TOP: port=%d, count=%d, in_interrupt=%ld\n",
917 		priv->dp_port_num, count, in_interrupt());
918 
919 	/* copy user data (which can sleep) before getting spin lock */
920 	count = min(count, port->bulk_out_size-2);
921 	count = min(64, count);
922 
923 	/* be sure only one write proceeds at a time */
924 	/* there are races on the port private buffer */
925 	spin_lock_irqsave(&priv->dp_port_lock, flags);
926 
927 	/* wait for urb status clear to submit another urb */
928 	if (priv->dp_write_urb_in_use) {
929 		/* buffer data if count is 1 (probably put_char) if possible */
930 		if (count == 1 && priv->dp_out_buf_len < DIGI_OUT_BUF_SIZE) {
931 			priv->dp_out_buf[priv->dp_out_buf_len++] = *buf;
932 			new_len = 1;
933 		} else {
934 			new_len = 0;
935 		}
936 		spin_unlock_irqrestore(&priv->dp_port_lock, flags);
937 		return new_len;
938 	}
939 
940 	/* allow space for any buffered data and for new data, up to */
941 	/* transfer buffer size - 2 (for command and length bytes) */
942 	new_len = min(count, port->bulk_out_size-2-priv->dp_out_buf_len);
943 	data_len = new_len + priv->dp_out_buf_len;
944 
945 	if (data_len == 0) {
946 		spin_unlock_irqrestore(&priv->dp_port_lock, flags);
947 		return 0;
948 	}
949 
950 	port->write_urb->transfer_buffer_length = data_len+2;
951 
952 	*data++ = DIGI_CMD_SEND_DATA;
953 	*data++ = data_len;
954 
955 	/* copy in buffered data first */
956 	memcpy(data, priv->dp_out_buf, priv->dp_out_buf_len);
957 	data += priv->dp_out_buf_len;
958 
959 	/* copy in new data */
960 	memcpy(data, buf, new_len);
961 
962 	ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
963 	if (ret == 0) {
964 		priv->dp_write_urb_in_use = 1;
965 		ret = new_len;
966 		priv->dp_out_buf_len = 0;
967 	}
968 
969 	/* return length of new data written, or error */
970 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
971 	if (ret < 0)
972 		dev_err_console(port,
973 			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
974 			__func__, ret, priv->dp_port_num);
975 	dev_dbg(&port->dev, "digi_write: returning %d\n", ret);
976 	return ret;
977 
978 }
979 
980 static void digi_write_bulk_callback(struct urb *urb)
981 {
982 
983 	struct usb_serial_port *port = urb->context;
984 	struct usb_serial *serial;
985 	struct digi_port *priv;
986 	struct digi_serial *serial_priv;
987 	unsigned long flags;
988 	int ret = 0;
989 	int status = urb->status;
990 
991 	/* port and serial sanity check */
992 	if (port == NULL || (priv = usb_get_serial_port_data(port)) == NULL) {
993 		pr_err("%s: port or port->private is NULL, status=%d\n",
994 			__func__, status);
995 		return;
996 	}
997 	serial = port->serial;
998 	if (serial == NULL || (serial_priv = usb_get_serial_data(serial)) == NULL) {
999 		dev_err(&port->dev,
1000 			"%s: serial or serial->private is NULL, status=%d\n",
1001 			__func__, status);
1002 		return;
1003 	}
1004 
1005 	/* handle oob callback */
1006 	if (priv->dp_port_num == serial_priv->ds_oob_port_num) {
1007 		dev_dbg(&port->dev, "digi_write_bulk_callback: oob callback\n");
1008 		spin_lock_irqsave(&priv->dp_port_lock, flags);
1009 		priv->dp_write_urb_in_use = 0;
1010 		wake_up_interruptible(&port->write_wait);
1011 		spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1012 		return;
1013 	}
1014 
1015 	/* try to send any buffered data on this port */
1016 	spin_lock_irqsave(&priv->dp_port_lock, flags);
1017 	priv->dp_write_urb_in_use = 0;
1018 	if (priv->dp_out_buf_len > 0) {
1019 		*((unsigned char *)(port->write_urb->transfer_buffer))
1020 			= (unsigned char)DIGI_CMD_SEND_DATA;
1021 		*((unsigned char *)(port->write_urb->transfer_buffer) + 1)
1022 			= (unsigned char)priv->dp_out_buf_len;
1023 		port->write_urb->transfer_buffer_length =
1024 						priv->dp_out_buf_len + 2;
1025 		memcpy(port->write_urb->transfer_buffer + 2, priv->dp_out_buf,
1026 			priv->dp_out_buf_len);
1027 		ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1028 		if (ret == 0) {
1029 			priv->dp_write_urb_in_use = 1;
1030 			priv->dp_out_buf_len = 0;
1031 		}
1032 	}
1033 	/* wake up processes sleeping on writes immediately */
1034 	tty_port_tty_wakeup(&port->port);
1035 	/* also queue up a wakeup at scheduler time, in case we */
1036 	/* lost the race in write_chan(). */
1037 	schedule_work(&priv->dp_wakeup_work);
1038 
1039 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1040 	if (ret && ret != -EPERM)
1041 		dev_err_console(port,
1042 			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
1043 			__func__, ret, priv->dp_port_num);
1044 }
1045 
1046 static int digi_write_room(struct tty_struct *tty)
1047 {
1048 	struct usb_serial_port *port = tty->driver_data;
1049 	struct digi_port *priv = usb_get_serial_port_data(port);
1050 	int room;
1051 	unsigned long flags = 0;
1052 
1053 	spin_lock_irqsave(&priv->dp_port_lock, flags);
1054 
1055 	if (priv->dp_write_urb_in_use)
1056 		room = 0;
1057 	else
1058 		room = port->bulk_out_size - 2 - priv->dp_out_buf_len;
1059 
1060 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1061 	dev_dbg(&port->dev, "digi_write_room: port=%d, room=%d\n", priv->dp_port_num, room);
1062 	return room;
1063 
1064 }
1065 
1066 static int digi_chars_in_buffer(struct tty_struct *tty)
1067 {
1068 	struct usb_serial_port *port = tty->driver_data;
1069 	struct digi_port *priv = usb_get_serial_port_data(port);
1070 
1071 	if (priv->dp_write_urb_in_use) {
1072 		dev_dbg(&port->dev, "digi_chars_in_buffer: port=%d, chars=%d\n",
1073 			priv->dp_port_num, port->bulk_out_size - 2);
1074 		/* return(port->bulk_out_size - 2); */
1075 		return 256;
1076 	} else {
1077 		dev_dbg(&port->dev, "digi_chars_in_buffer: port=%d, chars=%d\n",
1078 			priv->dp_port_num, priv->dp_out_buf_len);
1079 		return priv->dp_out_buf_len;
1080 	}
1081 
1082 }
1083 
1084 static void digi_dtr_rts(struct usb_serial_port *port, int on)
1085 {
1086 	/* Adjust DTR and RTS */
1087 	digi_set_modem_signals(port, on * (TIOCM_DTR|TIOCM_RTS), 1);
1088 }
1089 
1090 static int digi_open(struct tty_struct *tty, struct usb_serial_port *port)
1091 {
1092 	int ret;
1093 	unsigned char buf[32];
1094 	struct digi_port *priv = usb_get_serial_port_data(port);
1095 	struct ktermios not_termios;
1096 
1097 	/* be sure the device is started up */
1098 	if (digi_startup_device(port->serial) != 0)
1099 		return -ENXIO;
1100 
1101 	/* read modem signals automatically whenever they change */
1102 	buf[0] = DIGI_CMD_READ_INPUT_SIGNALS;
1103 	buf[1] = priv->dp_port_num;
1104 	buf[2] = DIGI_ENABLE;
1105 	buf[3] = 0;
1106 
1107 	/* flush fifos */
1108 	buf[4] = DIGI_CMD_IFLUSH_FIFO;
1109 	buf[5] = priv->dp_port_num;
1110 	buf[6] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
1111 	buf[7] = 0;
1112 
1113 	ret = digi_write_oob_command(port, buf, 8, 1);
1114 	if (ret != 0)
1115 		dev_dbg(&port->dev, "digi_open: write oob failed, ret=%d\n", ret);
1116 
1117 	/* set termios settings */
1118 	if (tty) {
1119 		not_termios.c_cflag = ~tty->termios.c_cflag;
1120 		not_termios.c_iflag = ~tty->termios.c_iflag;
1121 		digi_set_termios(tty, port, &not_termios);
1122 	}
1123 	return 0;
1124 }
1125 
1126 
1127 static void digi_close(struct usb_serial_port *port)
1128 {
1129 	DEFINE_WAIT(wait);
1130 	int ret;
1131 	unsigned char buf[32];
1132 	struct digi_port *priv = usb_get_serial_port_data(port);
1133 
1134 	mutex_lock(&port->serial->disc_mutex);
1135 	/* if disconnected, just clear flags */
1136 	if (port->serial->disconnected)
1137 		goto exit;
1138 
1139 	/* FIXME: Transmit idle belongs in the wait_unti_sent path */
1140 	digi_transmit_idle(port, DIGI_CLOSE_TIMEOUT);
1141 
1142 	/* disable input flow control */
1143 	buf[0] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
1144 	buf[1] = priv->dp_port_num;
1145 	buf[2] = DIGI_DISABLE;
1146 	buf[3] = 0;
1147 
1148 	/* disable output flow control */
1149 	buf[4] = DIGI_CMD_SET_OUTPUT_FLOW_CONTROL;
1150 	buf[5] = priv->dp_port_num;
1151 	buf[6] = DIGI_DISABLE;
1152 	buf[7] = 0;
1153 
1154 	/* disable reading modem signals automatically */
1155 	buf[8] = DIGI_CMD_READ_INPUT_SIGNALS;
1156 	buf[9] = priv->dp_port_num;
1157 	buf[10] = DIGI_DISABLE;
1158 	buf[11] = 0;
1159 
1160 	/* disable receive */
1161 	buf[12] = DIGI_CMD_RECEIVE_ENABLE;
1162 	buf[13] = priv->dp_port_num;
1163 	buf[14] = DIGI_DISABLE;
1164 	buf[15] = 0;
1165 
1166 	/* flush fifos */
1167 	buf[16] = DIGI_CMD_IFLUSH_FIFO;
1168 	buf[17] = priv->dp_port_num;
1169 	buf[18] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
1170 	buf[19] = 0;
1171 
1172 	ret = digi_write_oob_command(port, buf, 20, 0);
1173 	if (ret != 0)
1174 		dev_dbg(&port->dev, "digi_close: write oob failed, ret=%d\n",
1175 									ret);
1176 	/* wait for final commands on oob port to complete */
1177 	prepare_to_wait(&priv->dp_flush_wait, &wait,
1178 			TASK_INTERRUPTIBLE);
1179 	schedule_timeout(DIGI_CLOSE_TIMEOUT);
1180 	finish_wait(&priv->dp_flush_wait, &wait);
1181 
1182 	/* shutdown any outstanding bulk writes */
1183 	usb_kill_urb(port->write_urb);
1184 exit:
1185 	spin_lock_irq(&priv->dp_port_lock);
1186 	priv->dp_write_urb_in_use = 0;
1187 	wake_up_interruptible(&priv->dp_close_wait);
1188 	spin_unlock_irq(&priv->dp_port_lock);
1189 	mutex_unlock(&port->serial->disc_mutex);
1190 }
1191 
1192 
1193 /*
1194  *  Digi Startup Device
1195  *
1196  *  Starts reads on all ports.  Must be called AFTER startup, with
1197  *  urbs initialized.  Returns 0 if successful, non-zero error otherwise.
1198  */
1199 
1200 static int digi_startup_device(struct usb_serial *serial)
1201 {
1202 	int i, ret = 0;
1203 	struct digi_serial *serial_priv = usb_get_serial_data(serial);
1204 	struct usb_serial_port *port;
1205 
1206 	/* be sure this happens exactly once */
1207 	spin_lock(&serial_priv->ds_serial_lock);
1208 	if (serial_priv->ds_device_started) {
1209 		spin_unlock(&serial_priv->ds_serial_lock);
1210 		return 0;
1211 	}
1212 	serial_priv->ds_device_started = 1;
1213 	spin_unlock(&serial_priv->ds_serial_lock);
1214 
1215 	/* start reading from each bulk in endpoint for the device */
1216 	/* set USB_DISABLE_SPD flag for write bulk urbs */
1217 	for (i = 0; i < serial->type->num_ports + 1; i++) {
1218 		port = serial->port[i];
1219 		ret = usb_submit_urb(port->read_urb, GFP_KERNEL);
1220 		if (ret != 0) {
1221 			dev_err(&port->dev,
1222 				"%s: usb_submit_urb failed, ret=%d, port=%d\n",
1223 				__func__, ret, i);
1224 			break;
1225 		}
1226 	}
1227 	return ret;
1228 }
1229 
1230 static int digi_port_init(struct usb_serial_port *port, unsigned port_num)
1231 {
1232 	struct digi_port *priv;
1233 
1234 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1235 	if (!priv)
1236 		return -ENOMEM;
1237 
1238 	spin_lock_init(&priv->dp_port_lock);
1239 	priv->dp_port_num = port_num;
1240 	init_waitqueue_head(&priv->dp_transmit_idle_wait);
1241 	init_waitqueue_head(&priv->dp_flush_wait);
1242 	init_waitqueue_head(&priv->dp_close_wait);
1243 	INIT_WORK(&priv->dp_wakeup_work, digi_wakeup_write_lock);
1244 	priv->dp_port = port;
1245 
1246 	init_waitqueue_head(&port->write_wait);
1247 
1248 	usb_set_serial_port_data(port, priv);
1249 
1250 	return 0;
1251 }
1252 
1253 static int digi_startup(struct usb_serial *serial)
1254 {
1255 	struct digi_serial *serial_priv;
1256 	int ret;
1257 
1258 	serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL);
1259 	if (!serial_priv)
1260 		return -ENOMEM;
1261 
1262 	spin_lock_init(&serial_priv->ds_serial_lock);
1263 	serial_priv->ds_oob_port_num = serial->type->num_ports;
1264 	serial_priv->ds_oob_port = serial->port[serial_priv->ds_oob_port_num];
1265 
1266 	ret = digi_port_init(serial_priv->ds_oob_port,
1267 						serial_priv->ds_oob_port_num);
1268 	if (ret) {
1269 		kfree(serial_priv);
1270 		return ret;
1271 	}
1272 
1273 	usb_set_serial_data(serial, serial_priv);
1274 
1275 	return 0;
1276 }
1277 
1278 
1279 static void digi_disconnect(struct usb_serial *serial)
1280 {
1281 	int i;
1282 
1283 	/* stop reads and writes on all ports */
1284 	for (i = 0; i < serial->type->num_ports + 1; i++) {
1285 		usb_kill_urb(serial->port[i]->read_urb);
1286 		usb_kill_urb(serial->port[i]->write_urb);
1287 	}
1288 }
1289 
1290 
1291 static void digi_release(struct usb_serial *serial)
1292 {
1293 	struct digi_serial *serial_priv;
1294 	struct digi_port *priv;
1295 
1296 	serial_priv = usb_get_serial_data(serial);
1297 
1298 	priv = usb_get_serial_port_data(serial_priv->ds_oob_port);
1299 	kfree(priv);
1300 
1301 	kfree(serial_priv);
1302 }
1303 
1304 static int digi_port_probe(struct usb_serial_port *port)
1305 {
1306 	return digi_port_init(port, port->port_number);
1307 }
1308 
1309 static int digi_port_remove(struct usb_serial_port *port)
1310 {
1311 	struct digi_port *priv;
1312 
1313 	priv = usb_get_serial_port_data(port);
1314 	kfree(priv);
1315 
1316 	return 0;
1317 }
1318 
1319 static void digi_read_bulk_callback(struct urb *urb)
1320 {
1321 	struct usb_serial_port *port = urb->context;
1322 	struct digi_port *priv;
1323 	struct digi_serial *serial_priv;
1324 	int ret;
1325 	int status = urb->status;
1326 
1327 	/* port sanity check, do not resubmit if port is not valid */
1328 	if (port == NULL)
1329 		return;
1330 	priv = usb_get_serial_port_data(port);
1331 	if (priv == NULL) {
1332 		dev_err(&port->dev, "%s: port->private is NULL, status=%d\n",
1333 			__func__, status);
1334 		return;
1335 	}
1336 	if (port->serial == NULL ||
1337 		(serial_priv = usb_get_serial_data(port->serial)) == NULL) {
1338 		dev_err(&port->dev, "%s: serial is bad or serial->private "
1339 			"is NULL, status=%d\n", __func__, status);
1340 		return;
1341 	}
1342 
1343 	/* do not resubmit urb if it has any status error */
1344 	if (status) {
1345 		dev_err(&port->dev,
1346 			"%s: nonzero read bulk status: status=%d, port=%d\n",
1347 			__func__, status, priv->dp_port_num);
1348 		return;
1349 	}
1350 
1351 	/* handle oob or inb callback, do not resubmit if error */
1352 	if (priv->dp_port_num == serial_priv->ds_oob_port_num) {
1353 		if (digi_read_oob_callback(urb) != 0)
1354 			return;
1355 	} else {
1356 		if (digi_read_inb_callback(urb) != 0)
1357 			return;
1358 	}
1359 
1360 	/* continue read */
1361 	ret = usb_submit_urb(urb, GFP_ATOMIC);
1362 	if (ret != 0 && ret != -EPERM) {
1363 		dev_err(&port->dev,
1364 			"%s: failed resubmitting urb, ret=%d, port=%d\n",
1365 			__func__, ret, priv->dp_port_num);
1366 	}
1367 
1368 }
1369 
1370 /*
1371  *  Digi Read INB Callback
1372  *
1373  *  Digi Read INB Callback handles reads on the in band ports, sending
1374  *  the data on to the tty subsystem.  When called we know port and
1375  *  port->private are not NULL and port->serial has been validated.
1376  *  It returns 0 if successful, 1 if successful but the port is
1377  *  throttled, and -1 if the sanity checks failed.
1378  */
1379 
1380 static int digi_read_inb_callback(struct urb *urb)
1381 {
1382 	struct usb_serial_port *port = urb->context;
1383 	struct digi_port *priv = usb_get_serial_port_data(port);
1384 	unsigned char *buf = urb->transfer_buffer;
1385 	unsigned long flags;
1386 	int opcode;
1387 	int len;
1388 	int port_status;
1389 	unsigned char *data;
1390 	int tty_flag, throttled;
1391 
1392 	/* short/multiple packet check */
1393 	if (urb->actual_length < 2) {
1394 		dev_warn(&port->dev, "short packet received\n");
1395 		return -1;
1396 	}
1397 
1398 	opcode = buf[0];
1399 	len = buf[1];
1400 
1401 	if (urb->actual_length != len + 2) {
1402 		dev_err(&port->dev, "malformed packet received: port=%d, opcode=%d, len=%d, actual_length=%u\n",
1403 			priv->dp_port_num, opcode, len, urb->actual_length);
1404 		return -1;
1405 	}
1406 
1407 	if (opcode == DIGI_CMD_RECEIVE_DATA && len < 1) {
1408 		dev_err(&port->dev, "malformed data packet received\n");
1409 		return -1;
1410 	}
1411 
1412 	spin_lock_irqsave(&priv->dp_port_lock, flags);
1413 
1414 	/* check for throttle; if set, do not resubmit read urb */
1415 	/* indicate the read chain needs to be restarted on unthrottle */
1416 	throttled = priv->dp_throttled;
1417 	if (throttled)
1418 		priv->dp_throttle_restart = 1;
1419 
1420 	/* receive data */
1421 	if (opcode == DIGI_CMD_RECEIVE_DATA) {
1422 		port_status = buf[2];
1423 		data = &buf[3];
1424 
1425 		/* get flag from port_status */
1426 		tty_flag = 0;
1427 
1428 		/* overrun is special, not associated with a char */
1429 		if (port_status & DIGI_OVERRUN_ERROR)
1430 			tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
1431 
1432 		/* break takes precedence over parity, */
1433 		/* which takes precedence over framing errors */
1434 		if (port_status & DIGI_BREAK_ERROR)
1435 			tty_flag = TTY_BREAK;
1436 		else if (port_status & DIGI_PARITY_ERROR)
1437 			tty_flag = TTY_PARITY;
1438 		else if (port_status & DIGI_FRAMING_ERROR)
1439 			tty_flag = TTY_FRAME;
1440 
1441 		/* data length is len-1 (one byte of len is port_status) */
1442 		--len;
1443 		if (len > 0) {
1444 			tty_insert_flip_string_fixed_flag(&port->port, data,
1445 					tty_flag, len);
1446 			tty_flip_buffer_push(&port->port);
1447 		}
1448 	}
1449 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1450 
1451 	if (opcode == DIGI_CMD_RECEIVE_DISABLE)
1452 		dev_dbg(&port->dev, "%s: got RECEIVE_DISABLE\n", __func__);
1453 	else if (opcode != DIGI_CMD_RECEIVE_DATA)
1454 		dev_dbg(&port->dev, "%s: unknown opcode: %d\n", __func__, opcode);
1455 
1456 	return throttled ? 1 : 0;
1457 
1458 }
1459 
1460 
1461 /*
1462  *  Digi Read OOB Callback
1463  *
1464  *  Digi Read OOB Callback handles reads on the out of band port.
1465  *  When called we know port and port->private are not NULL and
1466  *  the port->serial is valid.  It returns 0 if successful, and
1467  *  -1 if the sanity checks failed.
1468  */
1469 
1470 static int digi_read_oob_callback(struct urb *urb)
1471 {
1472 
1473 	struct usb_serial_port *port = urb->context;
1474 	struct usb_serial *serial = port->serial;
1475 	struct tty_struct *tty;
1476 	struct digi_port *priv = usb_get_serial_port_data(port);
1477 	unsigned char *buf = urb->transfer_buffer;
1478 	int opcode, line, status, val;
1479 	unsigned long flags;
1480 	int i;
1481 	unsigned int rts;
1482 
1483 	if (urb->actual_length < 4)
1484 		return -1;
1485 
1486 	/* handle each oob command */
1487 	for (i = 0; i < urb->actual_length - 3; i += 4) {
1488 		opcode = buf[i];
1489 		line = buf[i + 1];
1490 		status = buf[i + 2];
1491 		val = buf[i + 3];
1492 
1493 		dev_dbg(&port->dev, "digi_read_oob_callback: opcode=%d, line=%d, status=%d, val=%d\n",
1494 			opcode, line, status, val);
1495 
1496 		if (status != 0 || line >= serial->type->num_ports)
1497 			continue;
1498 
1499 		port = serial->port[line];
1500 
1501 		priv = usb_get_serial_port_data(port);
1502 		if (priv == NULL)
1503 			return -1;
1504 
1505 		tty = tty_port_tty_get(&port->port);
1506 
1507 		rts = 0;
1508 		if (tty)
1509 			rts = C_CRTSCTS(tty);
1510 
1511 		if (tty && opcode == DIGI_CMD_READ_INPUT_SIGNALS) {
1512 			spin_lock_irqsave(&priv->dp_port_lock, flags);
1513 			/* convert from digi flags to termiox flags */
1514 			if (val & DIGI_READ_INPUT_SIGNALS_CTS) {
1515 				priv->dp_modem_signals |= TIOCM_CTS;
1516 				/* port must be open to use tty struct */
1517 				if (rts)
1518 					tty_port_tty_wakeup(&port->port);
1519 			} else {
1520 				priv->dp_modem_signals &= ~TIOCM_CTS;
1521 				/* port must be open to use tty struct */
1522 			}
1523 			if (val & DIGI_READ_INPUT_SIGNALS_DSR)
1524 				priv->dp_modem_signals |= TIOCM_DSR;
1525 			else
1526 				priv->dp_modem_signals &= ~TIOCM_DSR;
1527 			if (val & DIGI_READ_INPUT_SIGNALS_RI)
1528 				priv->dp_modem_signals |= TIOCM_RI;
1529 			else
1530 				priv->dp_modem_signals &= ~TIOCM_RI;
1531 			if (val & DIGI_READ_INPUT_SIGNALS_DCD)
1532 				priv->dp_modem_signals |= TIOCM_CD;
1533 			else
1534 				priv->dp_modem_signals &= ~TIOCM_CD;
1535 
1536 			spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1537 		} else if (opcode == DIGI_CMD_TRANSMIT_IDLE) {
1538 			spin_lock_irqsave(&priv->dp_port_lock, flags);
1539 			priv->dp_transmit_idle = 1;
1540 			wake_up_interruptible(&priv->dp_transmit_idle_wait);
1541 			spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1542 		} else if (opcode == DIGI_CMD_IFLUSH_FIFO) {
1543 			wake_up_interruptible(&priv->dp_flush_wait);
1544 		}
1545 		tty_kref_put(tty);
1546 	}
1547 	return 0;
1548 
1549 }
1550 
1551 module_usb_serial_driver(serial_drivers, id_table_combined);
1552 
1553 MODULE_AUTHOR(DRIVER_AUTHOR);
1554 MODULE_DESCRIPTION(DRIVER_DESC);
1555 MODULE_LICENSE("GPL");
1556