1 /*
2 *  Digi AccelePort USB-4 and USB-2 Serial Converters
3 *
4 *  Copyright 2000 by Digi International
5 *
6 *  This program is free software; you can redistribute it and/or modify
7 *  it under the terms of the GNU General Public License as published by
8 *  the Free Software Foundation; either version 2 of the License, or
9 *  (at your option) any later version.
10 *
11 *  Shamelessly based on Brian Warner's keyspan_pda.c and Greg Kroah-Hartman's
12 *  usb-serial driver.
13 *
14 *  Peter Berger (pberger@brimson.com)
15 *  Al Borchers (borchers@steinerpoint.com)
16 *
17 * (12/03/2001) gkh
18 *	switched to using port->open_count instead of private version.
19 *	Removed port->active
20 *
21 * (04/08/2001) gb
22 *	Identify version on module load.
23 *
24 * (11/01/2000) Adam J. Richter
25 *	usb_device_id table support
26 *
27 * (11/01/2000) pberger and borchers
28 *    -- Turned off the USB_DISABLE_SPD flag for write bulk urbs--it caused
29 *       USB 4 ports to hang on startup.
30 *    -- Serialized access to write urbs by adding the dp_write_urb_in_use
31 *       flag; otherwise, the driver caused SMP system hangs.  Watching the
32 *       urb status is not sufficient.
33 *
34 * (10/05/2000) gkh
35 *    -- Fixed bug with urb->dev not being set properly, now that the usb
36 *	core needs it.
37 *
38 *  (8/8/2000) pberger and borchers
39 *    -- Fixed close so that
40 *       - it can timeout while waiting for transmit idle, if needed;
41 *       - it ignores interrupts when flushing the port, turning
42 *         of modem signalling, and so on;
43 *       - it waits for the flush to really complete before returning.
44 *    -- Read_bulk_callback and write_bulk_callback check for a closed
45 *       port before using the tty struct or writing to the port.
46 *    -- The two changes above fix the oops caused by interrupted closes.
47 *    -- Added interruptible args to write_oob_command and set_modem_signals
48 *       and added a timeout arg to transmit_idle; needed for fixes to
49 *       close.
50 *    -- Added code for rx_throttle and rx_unthrottle so that input flow
51 *       control works.
52 *    -- Added code to set overrun, parity, framing, and break errors
53 *       (untested).
54 *    -- Set USB_DISABLE_SPD flag for write bulk urbs, so no 0 length
55 *       bulk writes are done.  These hung the Digi USB device.  The
56 *       0 length bulk writes were a new feature of usb-uhci added in
57 *       the 2.4.0-test6 kernels.
58 *    -- Fixed mod inc race in open; do mod inc before sleeping to wait
59 *       for a close to finish.
60 *
61 *  (7/31/2000) pberger
62 *    -- Fixed bugs with hardware handshaking:
63 *       - Added code to set/clear tty->hw_stopped in digi_read_oob_callback()
64 *         and digi_set_termios()
65 *    -- Added code in digi_set_termios() to
66 *       - add conditional in code handling transition from B0 to only
67 *         set RTS if RTS/CTS flow control is either not in use or if
68 *         the port is not currently throttled.
69 *       - handle turning off CRTSCTS.
70 *
71 *  (7/30/2000) borchers
72 *    -- Added support for more than one Digi USB device by moving
73 *       globals to a private structure in the pointed to from the
74 *       usb_serial structure.
75 *    -- Moved the modem change and transmit idle wait queues into
76 *       the port private structure, so each port has its own queue
77 *       rather than sharing global queues.
78 *    -- Added support for break signals.
79 *
80 *  (7/25/2000) pberger
81 *    -- Added USB-2 support.  Note: the USB-2 supports 3 devices: two
82 *       serial and a parallel port.  The parallel port is implemented
83 *       as a serial-to-parallel converter.  That is, the driver actually
84 *       presents all three USB-2 interfaces as serial ports, but the third
85 *       one physically connects to a parallel device.  Thus, for example,
86 *       one could plug a parallel printer into the USB-2's third port,
87 *       but from the kernel's (and userland's) point of view what's
88 *       actually out there is a serial device.
89 *
90 *  (7/15/2000) borchers
91 *    -- Fixed race in open when a close is in progress.
92 *    -- Keep count of opens and dec the module use count for each
93 *       outstanding open when shutdown is called (on disconnect).
94 *    -- Fixed sanity checks in read_bulk_callback and write_bulk_callback
95 *       so pointers are checked before use.
96 *    -- Split read bulk callback into in band and out of band
97 *       callbacks, and no longer restart read chains if there is
98 *       a status error or a sanity error.  This fixed the seg
99 *       faults and other errors we used to get on disconnect.
100 *    -- Port->active is once again a flag as usb-serial intended it
101 *       to be, not a count.  Since it was only a char it would
102 *       have been limited to 256 simultaneous opens.  Now the open
103 *       count is kept in the port private structure in dp_open_count.
104 *    -- Added code for modularization of the digi_acceleport driver.
105 *
106 *  (6/27/2000) pberger and borchers
107 *    -- Zeroed out sync field in the wakeup_task before first use;
108 *       otherwise the uninitialized value might prevent the task from
109 *       being scheduled.
110 *    -- Initialized ret value to 0 in write_bulk_callback, otherwise
111 *       the uninitialized value could cause a spurious debugging message.
112 *
113 *  (6/22/2000) pberger and borchers
114 *    -- Made cond_wait_... inline--apparently on SPARC the flags arg
115 *       to spin_lock_irqsave cannot be passed to another function
116 *       to call spin_unlock_irqrestore.  Thanks to Pauline Middelink.
117 *    -- In digi_set_modem_signals the inner nested spin locks use just
118 *       spin_lock() rather than spin_lock_irqsave().  The old code
119 *       mistakenly left interrupts off.  Thanks to Pauline Middelink.
120 *    -- copy_from_user (which can sleep) is no longer called while a
121 *       spinlock is held.  We copy to a local buffer before getting
122 *       the spinlock--don't like the extra copy but the code is simpler.
123 *    -- Printk and dbg are no longer called while a spin lock is held.
124 *
125 *  (6/4/2000) pberger and borchers
126 *    -- Replaced separate calls to spin_unlock_irqrestore and
127 *       interruptible_sleep_on_timeout with a new function
128 *       cond_wait_interruptible_timeout_irqrestore.  This eliminates
129 *       the race condition where the wake up could happen after
130 *       the unlock and before the sleep.
131 *    -- Close now waits for output to drain.
132 *    -- Open waits until any close in progress is finished.
133 *    -- All out of band responses are now processed, not just the
134 *       first in a USB packet.
135 *    -- Fixed a bug that prevented the driver from working when the
136 *       first Digi port was not the first USB serial port--the driver
137 *       was mistakenly using the external USB serial port number to
138 *       try to index into its internal ports.
139 *    -- Fixed an SMP bug -- write_bulk_callback is called directly from
140 *       an interrupt, so spin_lock_irqsave/spin_unlock_irqrestore are
141 *       needed for locks outside write_bulk_callback that are also
142 *       acquired by write_bulk_callback to prevent deadlocks.
143 *    -- Fixed support for select() by making digi_chars_in_buffer()
144 *       return 256 when -EINPROGRESS is set, as the line discipline
145 *       code in n_tty.c expects.
146 *    -- Fixed an include file ordering problem that prevented debugging
147 *       messages from working.
148 *    -- Fixed an intermittent timeout problem that caused writes to
149 *       sometimes get stuck on some machines on some kernels.  It turns
150 *       out in these circumstances write_chan() (in n_tty.c) was
151 *       asleep waiting for our wakeup call.  Even though we call
152 *       wake_up_interruptible() in digi_write_bulk_callback(), there is
153 *       a race condition that could cause the wakeup to fail: if our
154 *       wake_up_interruptible() call occurs between the time that our
155 *       driver write routine finishes and write_chan() sets current->state
156 *       to TASK_INTERRUPTIBLE, the effect of our wakeup setting the state
157 *       to TASK_RUNNING will be lost and write_chan's subsequent call to
158 *       schedule() will never return (unless it catches a signal).
159 *       This race condition occurs because write_bulk_callback() (and thus
160 *       the wakeup) are called asynchronously from an interrupt, rather than
161 *       from the scheduler.  We can avoid the race by calling the wakeup
162 *       from the scheduler queue and that's our fix:  Now, at the end of
163 *       write_bulk_callback() we queue up a wakeup call on the scheduler
164 *       task queue.  We still also invoke the wakeup directly since that
165 *       squeezes a bit more performance out of the driver, and any lost
166 *       race conditions will get cleaned up at the next scheduler run.
167 *
168 *       NOTE:  The problem also goes away if you comment out
169 *       the two code lines in write_chan() where current->state
170 *       is set to TASK_RUNNING just before calling driver.write() and to
171 *       TASK_INTERRUPTIBLE immediately afterwards.  This is why the
172 *       problem did not show up with the 2.2 kernels -- they do not
173 *       include that code.
174 *
175 *  (5/16/2000) pberger and borchers
176 *    -- Added timeouts to sleeps, to defend against lost wake ups.
177 *    -- Handle transition to/from B0 baud rate in digi_set_termios.
178 *
179 *  (5/13/2000) pberger and borchers
180 *    -- All commands now sent on out of band port, using
181 *       digi_write_oob_command.
182 *    -- Get modem control signals whenever they change, support TIOCMGET/
183 *       SET/BIS/BIC ioctls.
184 *    -- digi_set_termios now supports parity, word size, stop bits, and
185 *       receive enable.
186 *    -- Cleaned up open and close, use digi_set_termios and
187 *       digi_write_oob_command to set port parameters.
188 *    -- Added digi_startup_device to start read chains on all ports.
189 *    -- Write buffer is only used when count==1, to be sure put_char can
190 *       write a char (unless the buffer is full).
191 *
192 *  (5/10/2000) pberger and borchers
193 *    -- Added MOD_INC_USE_COUNT/MOD_DEC_USE_COUNT calls on open/close.
194 *    -- Fixed problem where the first incoming character is lost on
195 *       port opens after the first close on that port.  Now we keep
196 *       the read_urb chain open until shutdown.
197 *    -- Added more port conditioning calls in digi_open and digi_close.
198 *    -- Convert port->active to a use count so that we can deal with multiple
199 *       opens and closes properly.
200 *    -- Fixed some problems with the locking code.
201 *
202 *  (5/3/2000) pberger and borchers
203 *    -- First alpha version of the driver--many known limitations and bugs.
204 *
205 *
206 *  Locking and SMP
207 *
208 *  - Each port, including the out-of-band port, has a lock used to
209 *    serialize all access to the port's private structure.
210 *  - The port lock is also used to serialize all writes and access to
211 *    the port's URB.
212 *  - The port lock is also used for the port write_wait condition
213 *    variable.  Holding the port lock will prevent a wake up on the
214 *    port's write_wait; this can be used with cond_wait_... to be sure
215 *    the wake up is not lost in a race when dropping the lock and
216 *    sleeping waiting for the wakeup.
217 *  - digi_write() does not sleep, since it is sometimes called on
218 *    interrupt time.
219 *  - digi_write_bulk_callback() and digi_read_bulk_callback() are
220 *    called directly from interrupts.  Hence spin_lock_irqsave()
221 *    and spin_unlock_irqrestore() are used in the rest of the code
222 *    for any locks they acquire.
223 *  - digi_write_bulk_callback() gets the port lock before waking up
224 *    processes sleeping on the port write_wait.  It also schedules
225 *    wake ups so they happen from the scheduler, because the tty
226 *    system can miss wake ups from interrupts.
227 *  - All sleeps use a timeout of DIGI_RETRY_TIMEOUT before looping to
228 *    recheck the condition they are sleeping on.  This is defensive,
229 *    in case a wake up is lost.
230 *  - Following Documentation/DocBook/kernel-locking.pdf no spin locks
231 *    are held when calling copy_to/from_user or printk.
232 *
233 *  $Id: digi_acceleport.c,v 1.80.1.2 2000/11/02 05:45:08 root Exp $
234 */
235 
236 #include <linux/kernel.h>
237 #include <linux/errno.h>
238 #include <linux/init.h>
239 #include <linux/slab.h>
240 #include <linux/tty.h>
241 #include <linux/tty_driver.h>
242 #include <linux/tty_flip.h>
243 #include <linux/module.h>
244 #include <linux/spinlock.h>
245 #include <linux/workqueue.h>
246 #include <asm/uaccess.h>
247 #include <linux/usb.h>
248 #include <linux/wait.h>
249 #include <linux/usb/serial.h>
250 
251 /* Defines */
252 
253 /*
254  * Version Information
255  */
256 #define DRIVER_VERSION "v1.80.1.2"
257 #define DRIVER_AUTHOR "Peter Berger <pberger@brimson.com>, Al Borchers <borchers@steinerpoint.com>"
258 #define DRIVER_DESC "Digi AccelePort USB-2/USB-4 Serial Converter driver"
259 
260 /* port output buffer length -- must be <= transfer buffer length - 2 */
261 /* so we can be sure to send the full buffer in one urb */
262 #define DIGI_OUT_BUF_SIZE		8
263 
264 /* port input buffer length -- must be >= transfer buffer length - 3 */
265 /* so we can be sure to hold at least one full buffer from one urb */
266 #define DIGI_IN_BUF_SIZE		64
267 
268 /* retry timeout while sleeping */
269 #define DIGI_RETRY_TIMEOUT		(HZ/10)
270 
271 /* timeout while waiting for tty output to drain in close */
272 /* this delay is used twice in close, so the total delay could */
273 /* be twice this value */
274 #define DIGI_CLOSE_TIMEOUT		(5*HZ)
275 
276 
277 /* AccelePort USB Defines */
278 
279 /* ids */
280 #define DIGI_VENDOR_ID			0x05c5
281 #define DIGI_2_ID			0x0002	/* USB-2 */
282 #define DIGI_4_ID			0x0004	/* USB-4 */
283 
284 /* commands
285  * "INB": can be used on the in-band endpoint
286  * "OOB": can be used on the out-of-band endpoint
287  */
288 #define DIGI_CMD_SET_BAUD_RATE			0	/* INB, OOB */
289 #define DIGI_CMD_SET_WORD_SIZE			1	/* INB, OOB */
290 #define DIGI_CMD_SET_PARITY			2	/* INB, OOB */
291 #define DIGI_CMD_SET_STOP_BITS			3	/* INB, OOB */
292 #define DIGI_CMD_SET_INPUT_FLOW_CONTROL		4	/* INB, OOB */
293 #define DIGI_CMD_SET_OUTPUT_FLOW_CONTROL	5	/* INB, OOB */
294 #define DIGI_CMD_SET_DTR_SIGNAL			6	/* INB, OOB */
295 #define DIGI_CMD_SET_RTS_SIGNAL			7	/* INB, OOB */
296 #define DIGI_CMD_READ_INPUT_SIGNALS		8	/*      OOB */
297 #define DIGI_CMD_IFLUSH_FIFO			9	/*      OOB */
298 #define DIGI_CMD_RECEIVE_ENABLE			10	/* INB, OOB */
299 #define DIGI_CMD_BREAK_CONTROL			11	/* INB, OOB */
300 #define DIGI_CMD_LOCAL_LOOPBACK			12	/* INB, OOB */
301 #define DIGI_CMD_TRANSMIT_IDLE			13	/* INB, OOB */
302 #define DIGI_CMD_READ_UART_REGISTER		14	/*      OOB */
303 #define DIGI_CMD_WRITE_UART_REGISTER		15	/* INB, OOB */
304 #define DIGI_CMD_AND_UART_REGISTER		16	/* INB, OOB */
305 #define DIGI_CMD_OR_UART_REGISTER		17	/* INB, OOB */
306 #define DIGI_CMD_SEND_DATA			18	/* INB      */
307 #define DIGI_CMD_RECEIVE_DATA			19	/* INB      */
308 #define DIGI_CMD_RECEIVE_DISABLE		20	/* INB      */
309 #define DIGI_CMD_GET_PORT_TYPE			21	/*      OOB */
310 
311 /* baud rates */
312 #define DIGI_BAUD_50				0
313 #define DIGI_BAUD_75				1
314 #define DIGI_BAUD_110				2
315 #define DIGI_BAUD_150				3
316 #define DIGI_BAUD_200				4
317 #define DIGI_BAUD_300				5
318 #define DIGI_BAUD_600				6
319 #define DIGI_BAUD_1200				7
320 #define DIGI_BAUD_1800				8
321 #define DIGI_BAUD_2400				9
322 #define DIGI_BAUD_4800				10
323 #define DIGI_BAUD_7200				11
324 #define DIGI_BAUD_9600				12
325 #define DIGI_BAUD_14400				13
326 #define DIGI_BAUD_19200				14
327 #define DIGI_BAUD_28800				15
328 #define DIGI_BAUD_38400				16
329 #define DIGI_BAUD_57600				17
330 #define DIGI_BAUD_76800				18
331 #define DIGI_BAUD_115200			19
332 #define DIGI_BAUD_153600			20
333 #define DIGI_BAUD_230400			21
334 #define DIGI_BAUD_460800			22
335 
336 /* arguments */
337 #define DIGI_WORD_SIZE_5			0
338 #define DIGI_WORD_SIZE_6			1
339 #define DIGI_WORD_SIZE_7			2
340 #define DIGI_WORD_SIZE_8			3
341 
342 #define DIGI_PARITY_NONE			0
343 #define DIGI_PARITY_ODD				1
344 #define DIGI_PARITY_EVEN			2
345 #define DIGI_PARITY_MARK			3
346 #define DIGI_PARITY_SPACE			4
347 
348 #define DIGI_STOP_BITS_1			0
349 #define DIGI_STOP_BITS_2			1
350 
351 #define DIGI_INPUT_FLOW_CONTROL_XON_XOFF	1
352 #define DIGI_INPUT_FLOW_CONTROL_RTS		2
353 #define DIGI_INPUT_FLOW_CONTROL_DTR		4
354 
355 #define DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF	1
356 #define DIGI_OUTPUT_FLOW_CONTROL_CTS		2
357 #define DIGI_OUTPUT_FLOW_CONTROL_DSR		4
358 
359 #define DIGI_DTR_INACTIVE			0
360 #define DIGI_DTR_ACTIVE				1
361 #define DIGI_DTR_INPUT_FLOW_CONTROL		2
362 
363 #define DIGI_RTS_INACTIVE			0
364 #define DIGI_RTS_ACTIVE				1
365 #define DIGI_RTS_INPUT_FLOW_CONTROL		2
366 #define DIGI_RTS_TOGGLE				3
367 
368 #define DIGI_FLUSH_TX				1
369 #define DIGI_FLUSH_RX				2
370 #define DIGI_RESUME_TX				4 /* clears xoff condition */
371 
372 #define DIGI_TRANSMIT_NOT_IDLE			0
373 #define DIGI_TRANSMIT_IDLE			1
374 
375 #define DIGI_DISABLE				0
376 #define DIGI_ENABLE				1
377 
378 #define DIGI_DEASSERT				0
379 #define DIGI_ASSERT				1
380 
381 /* in band status codes */
382 #define DIGI_OVERRUN_ERROR			4
383 #define DIGI_PARITY_ERROR			8
384 #define DIGI_FRAMING_ERROR			16
385 #define DIGI_BREAK_ERROR			32
386 
387 /* out of band status */
388 #define DIGI_NO_ERROR				0
389 #define DIGI_BAD_FIRST_PARAMETER		1
390 #define DIGI_BAD_SECOND_PARAMETER		2
391 #define DIGI_INVALID_LINE			3
392 #define DIGI_INVALID_OPCODE			4
393 
394 /* input signals */
395 #define DIGI_READ_INPUT_SIGNALS_SLOT		1
396 #define DIGI_READ_INPUT_SIGNALS_ERR		2
397 #define DIGI_READ_INPUT_SIGNALS_BUSY		4
398 #define DIGI_READ_INPUT_SIGNALS_PE		8
399 #define DIGI_READ_INPUT_SIGNALS_CTS		16
400 #define DIGI_READ_INPUT_SIGNALS_DSR		32
401 #define DIGI_READ_INPUT_SIGNALS_RI		64
402 #define DIGI_READ_INPUT_SIGNALS_DCD		128
403 
404 
405 /* Structures */
406 
407 struct digi_serial {
408 	spinlock_t ds_serial_lock;
409 	struct usb_serial_port *ds_oob_port;	/* out-of-band port */
410 	int ds_oob_port_num;			/* index of out-of-band port */
411 	int ds_device_started;
412 };
413 
414 struct digi_port {
415 	spinlock_t dp_port_lock;
416 	int dp_port_num;
417 	int dp_out_buf_len;
418 	unsigned char dp_out_buf[DIGI_OUT_BUF_SIZE];
419 	int dp_write_urb_in_use;
420 	unsigned int dp_modem_signals;
421 	wait_queue_head_t dp_modem_change_wait;
422 	int dp_transmit_idle;
423 	wait_queue_head_t dp_transmit_idle_wait;
424 	int dp_throttled;
425 	int dp_throttle_restart;
426 	wait_queue_head_t dp_flush_wait;
427 	int dp_in_close;			/* close in progress */
428 	wait_queue_head_t dp_close_wait;	/* wait queue for close */
429 	struct work_struct dp_wakeup_work;
430 	struct usb_serial_port *dp_port;
431 };
432 
433 
434 /* Local Function Declarations */
435 
436 static void digi_wakeup_write(struct usb_serial_port *port);
437 static void digi_wakeup_write_lock(struct work_struct *work);
438 static int digi_write_oob_command(struct usb_serial_port *port,
439 	unsigned char *buf, int count, int interruptible);
440 static int digi_write_inb_command(struct usb_serial_port *port,
441 	unsigned char *buf, int count, unsigned long timeout);
442 static int digi_set_modem_signals(struct usb_serial_port *port,
443 	unsigned int modem_signals, int interruptible);
444 static int digi_transmit_idle(struct usb_serial_port *port,
445 	unsigned long timeout);
446 static void digi_rx_throttle (struct usb_serial_port *port);
447 static void digi_rx_unthrottle (struct usb_serial_port *port);
448 static void digi_set_termios(struct usb_serial_port *port,
449 	struct ktermios *old_termios);
450 static void digi_break_ctl(struct usb_serial_port *port, int break_state);
451 static int digi_ioctl(struct usb_serial_port *port, struct file *file,
452 	unsigned int cmd, unsigned long arg);
453 static int digi_tiocmget(struct usb_serial_port *port, struct file *file);
454 static int digi_tiocmset(struct usb_serial_port *port, struct file *file,
455 	unsigned int set, unsigned int clear);
456 static int digi_write(struct usb_serial_port *port, const unsigned char *buf, int count);
457 static void digi_write_bulk_callback(struct urb *urb);
458 static int digi_write_room(struct usb_serial_port *port);
459 static int digi_chars_in_buffer(struct usb_serial_port *port);
460 static int digi_open(struct usb_serial_port *port, struct file *filp);
461 static void digi_close(struct usb_serial_port *port, struct file *filp);
462 static int digi_startup_device(struct usb_serial *serial);
463 static int digi_startup(struct usb_serial *serial);
464 static void digi_shutdown(struct usb_serial *serial);
465 static void digi_read_bulk_callback(struct urb *urb);
466 static int digi_read_inb_callback(struct urb *urb);
467 static int digi_read_oob_callback(struct urb *urb);
468 
469 
470 /* Statics */
471 
472 static int debug;
473 
474 static struct usb_device_id id_table_combined [] = {
475 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_2_ID) },
476 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_4_ID) },
477 	{ }						/* Terminating entry */
478 };
479 
480 static struct usb_device_id id_table_2 [] = {
481 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_2_ID) },
482 	{ }						/* Terminating entry */
483 };
484 
485 static struct usb_device_id id_table_4 [] = {
486 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_4_ID) },
487 	{ }						/* Terminating entry */
488 };
489 
490 MODULE_DEVICE_TABLE (usb, id_table_combined);
491 
492 static struct usb_driver digi_driver = {
493 	.name =		"digi_acceleport",
494 	.probe =	usb_serial_probe,
495 	.disconnect =	usb_serial_disconnect,
496 	.id_table =	id_table_combined,
497 	.no_dynamic_id = 	1,
498 };
499 
500 
501 /* device info needed for the Digi serial converter */
502 
503 static struct usb_serial_driver digi_acceleport_2_device = {
504 	.driver = {
505 		.owner =		THIS_MODULE,
506 		.name =			"digi_2",
507 	},
508 	.description =			"Digi 2 port USB adapter",
509 	.usb_driver = 			&digi_driver,
510 	.id_table =			id_table_2,
511 	.num_ports =			3,
512 	.open =				digi_open,
513 	.close =			digi_close,
514 	.write =			digi_write,
515 	.write_room =			digi_write_room,
516 	.write_bulk_callback = 		digi_write_bulk_callback,
517 	.read_bulk_callback =		digi_read_bulk_callback,
518 	.chars_in_buffer =		digi_chars_in_buffer,
519 	.throttle =			digi_rx_throttle,
520 	.unthrottle =			digi_rx_unthrottle,
521 	.ioctl =			digi_ioctl,
522 	.set_termios =			digi_set_termios,
523 	.break_ctl =			digi_break_ctl,
524 	.tiocmget =			digi_tiocmget,
525 	.tiocmset =			digi_tiocmset,
526 	.attach =			digi_startup,
527 	.shutdown =			digi_shutdown,
528 };
529 
530 static struct usb_serial_driver digi_acceleport_4_device = {
531 	.driver = {
532 		.owner =		THIS_MODULE,
533 		.name =			"digi_4",
534 	},
535 	.description =			"Digi 4 port USB adapter",
536 	.usb_driver = 			&digi_driver,
537 	.id_table =			id_table_4,
538 	.num_ports =			4,
539 	.open =				digi_open,
540 	.close =			digi_close,
541 	.write =			digi_write,
542 	.write_room =			digi_write_room,
543 	.write_bulk_callback = 		digi_write_bulk_callback,
544 	.read_bulk_callback =		digi_read_bulk_callback,
545 	.chars_in_buffer =		digi_chars_in_buffer,
546 	.throttle =			digi_rx_throttle,
547 	.unthrottle =			digi_rx_unthrottle,
548 	.ioctl =			digi_ioctl,
549 	.set_termios =			digi_set_termios,
550 	.break_ctl =			digi_break_ctl,
551 	.tiocmget =			digi_tiocmget,
552 	.tiocmset =			digi_tiocmset,
553 	.attach =			digi_startup,
554 	.shutdown =			digi_shutdown,
555 };
556 
557 
558 /* Functions */
559 
560 /*
561 *  Cond Wait Interruptible Timeout Irqrestore
562 *
563 *  Do spin_unlock_irqrestore and interruptible_sleep_on_timeout
564 *  so that wake ups are not lost if they occur between the unlock
565 *  and the sleep.  In other words, spin_unlock_irqrestore and
566 *  interruptible_sleep_on_timeout are "atomic" with respect to
567 *  wake ups.  This is used to implement condition variables.
568 *
569 *  interruptible_sleep_on_timeout is deprecated and has been replaced
570 *  with the equivalent code.
571 */
572 
573 static long cond_wait_interruptible_timeout_irqrestore(
574 	wait_queue_head_t *q, long timeout,
575 	spinlock_t *lock, unsigned long flags)
576 {
577 	DEFINE_WAIT(wait);
578 
579 	prepare_to_wait(q, &wait, TASK_INTERRUPTIBLE);
580 	spin_unlock_irqrestore(lock, flags);
581 	timeout = schedule_timeout(timeout);
582 	finish_wait(q, &wait);
583 
584 	return timeout;
585 }
586 
587 
588 /*
589 *  Digi Wakeup Write
590 *
591 *  Wake up port, line discipline, and tty processes sleeping
592 *  on writes.
593 */
594 
595 static void digi_wakeup_write_lock(struct work_struct *work)
596 {
597 	struct digi_port *priv = container_of(work, struct digi_port, dp_wakeup_work);
598 	struct usb_serial_port *port = priv->dp_port;
599 	unsigned long flags;
600 
601 	spin_lock_irqsave(&priv->dp_port_lock, flags);
602 	digi_wakeup_write(port);
603 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
604 }
605 
606 static void digi_wakeup_write(struct usb_serial_port *port)
607 {
608 	tty_wakeup(port->tty);
609 }
610 
611 
612 /*
613 *  Digi Write OOB Command
614 *
615 *  Write commands on the out of band port.  Commands are 4
616 *  bytes each, multiple commands can be sent at once, and
617 *  no command will be split across USB packets.  Returns 0
618 *  if successful, -EINTR if interrupted while sleeping and
619 *  the interruptible flag is true, or a negative error
620 *  returned by usb_submit_urb.
621 */
622 
623 static int digi_write_oob_command(struct usb_serial_port *port,
624 	unsigned char *buf, int count, int interruptible)
625 {
626 
627 	int ret = 0;
628 	int len;
629 	struct usb_serial_port *oob_port = (struct usb_serial_port *)((struct digi_serial *)(usb_get_serial_data(port->serial)))->ds_oob_port;
630 	struct digi_port *oob_priv = usb_get_serial_port_data(oob_port);
631 	unsigned long flags = 0;
632 
633 	dbg("digi_write_oob_command: TOP: port=%d, count=%d", oob_priv->dp_port_num, count);
634 
635 	spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
636 	while(count > 0) {
637 		while(oob_port->write_urb->status == -EINPROGRESS
638 			|| oob_priv->dp_write_urb_in_use) {
639 			cond_wait_interruptible_timeout_irqrestore(
640 				&oob_port->write_wait, DIGI_RETRY_TIMEOUT,
641 				&oob_priv->dp_port_lock, flags);
642 			if (interruptible && signal_pending(current))
643 				return -EINTR;
644 			spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
645 		}
646 
647 		/* len must be a multiple of 4, so commands are not split */
648 		len = min(count, oob_port->bulk_out_size);
649 		if (len > 4)
650 			len &= ~3;
651 		memcpy(oob_port->write_urb->transfer_buffer, buf, len);
652 		oob_port->write_urb->transfer_buffer_length = len;
653 		oob_port->write_urb->dev = port->serial->dev;
654 		if ((ret = usb_submit_urb(oob_port->write_urb, GFP_ATOMIC)) == 0) {
655 			oob_priv->dp_write_urb_in_use = 1;
656 			count -= len;
657 			buf += len;
658 		}
659 	}
660 	spin_unlock_irqrestore(&oob_priv->dp_port_lock, flags);
661 	if (ret)
662 		err("%s: usb_submit_urb failed, ret=%d", __func__, ret);
663 	return ret;
664 
665 }
666 
667 
668 /*
669 *  Digi Write In Band Command
670 *
671 *  Write commands on the given port.  Commands are 4
672 *  bytes each, multiple commands can be sent at once, and
673 *  no command will be split across USB packets.  If timeout
674 *  is non-zero, write in band command will return after
675 *  waiting unsuccessfully for the URB status to clear for
676 *  timeout ticks.  Returns 0 if successful, or a negative
677 *  error returned by digi_write.
678 */
679 
680 static int digi_write_inb_command(struct usb_serial_port *port,
681 	unsigned char *buf, int count, unsigned long timeout)
682 {
683 	int ret = 0;
684 	int len;
685 	struct digi_port *priv = usb_get_serial_port_data(port);
686 	unsigned char *data = port->write_urb->transfer_buffer;
687 	unsigned long flags = 0;
688 
689 	dbg("digi_write_inb_command: TOP: port=%d, count=%d",
690 		priv->dp_port_num, count);
691 
692 	if (timeout)
693 		timeout += jiffies;
694 	else
695 		timeout = ULONG_MAX;
696 
697 	spin_lock_irqsave(&priv->dp_port_lock, flags);
698 	while(count > 0 && ret == 0) {
699 		while((port->write_urb->status == -EINPROGRESS
700 			|| priv->dp_write_urb_in_use) && time_before(jiffies, timeout)) {
701 			cond_wait_interruptible_timeout_irqrestore(
702 				&port->write_wait, DIGI_RETRY_TIMEOUT,
703 				&priv->dp_port_lock, flags);
704 			if (signal_pending(current))
705 				return -EINTR;
706 			spin_lock_irqsave(&priv->dp_port_lock, flags);
707 		}
708 
709 		/* len must be a multiple of 4 and small enough to */
710 		/* guarantee the write will send buffered data first, */
711 		/* so commands are in order with data and not split */
712 		len = min(count, port->bulk_out_size-2-priv->dp_out_buf_len);
713 		if (len > 4)
714 			len &= ~3;
715 
716 		/* write any buffered data first */
717 		if (priv->dp_out_buf_len > 0) {
718 			data[0] = DIGI_CMD_SEND_DATA;
719 			data[1] = priv->dp_out_buf_len;
720 			memcpy(data + 2, priv->dp_out_buf,
721 				priv->dp_out_buf_len);
722 			memcpy(data + 2 + priv->dp_out_buf_len, buf, len);
723 			port->write_urb->transfer_buffer_length
724 				= priv->dp_out_buf_len + 2 + len;
725 		} else {
726 			memcpy(data, buf, len);
727 			port->write_urb->transfer_buffer_length = len;
728 		}
729 		port->write_urb->dev = port->serial->dev;
730 
731 		if ((ret = usb_submit_urb(port->write_urb, GFP_ATOMIC)) == 0) {
732 			priv->dp_write_urb_in_use = 1;
733 			priv->dp_out_buf_len = 0;
734 			count -= len;
735 			buf += len;
736 		}
737 
738 	}
739 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
740 
741 	if (ret)
742 		err("%s: usb_submit_urb failed, ret=%d, port=%d",
743 			__func__, ret, priv->dp_port_num);
744 	return ret;
745 }
746 
747 
748 /*
749 *  Digi Set Modem Signals
750 *
751 *  Sets or clears DTR and RTS on the port, according to the
752 *  modem_signals argument.  Use TIOCM_DTR and TIOCM_RTS flags
753 *  for the modem_signals argument.  Returns 0 if successful,
754 *  -EINTR if interrupted while sleeping, or a non-zero error
755 *  returned by usb_submit_urb.
756 */
757 
758 static int digi_set_modem_signals(struct usb_serial_port *port,
759 	unsigned int modem_signals, int interruptible)
760 {
761 
762 	int ret;
763 	struct digi_port *port_priv = usb_get_serial_port_data(port);
764 	struct usb_serial_port *oob_port = (struct usb_serial_port *)((struct digi_serial *)(usb_get_serial_data(port->serial)))->ds_oob_port;
765 	struct digi_port *oob_priv = usb_get_serial_port_data(oob_port);
766 	unsigned char *data = oob_port->write_urb->transfer_buffer;
767 	unsigned long flags = 0;
768 
769 
770 	dbg("digi_set_modem_signals: TOP: port=%d, modem_signals=0x%x",
771 		port_priv->dp_port_num, modem_signals);
772 
773 	spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
774 	spin_lock(&port_priv->dp_port_lock);
775 
776 	while(oob_port->write_urb->status == -EINPROGRESS || oob_priv->dp_write_urb_in_use) {
777 		spin_unlock(&port_priv->dp_port_lock);
778 		cond_wait_interruptible_timeout_irqrestore(
779 			&oob_port->write_wait, DIGI_RETRY_TIMEOUT,
780 			&oob_priv->dp_port_lock, flags);
781 		if (interruptible && signal_pending(current))
782 			return -EINTR;
783 		spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
784 		spin_lock(&port_priv->dp_port_lock);
785 	}
786 	data[0] = DIGI_CMD_SET_DTR_SIGNAL;
787 	data[1] = port_priv->dp_port_num;
788 	data[2] = (modem_signals&TIOCM_DTR) ? DIGI_DTR_ACTIVE : DIGI_DTR_INACTIVE;
789 	data[3] = 0;
790 	data[4] = DIGI_CMD_SET_RTS_SIGNAL;
791 	data[5] = port_priv->dp_port_num;
792 	data[6] = (modem_signals&TIOCM_RTS) ? DIGI_RTS_ACTIVE : DIGI_RTS_INACTIVE;
793 	data[7] = 0;
794 
795 	oob_port->write_urb->transfer_buffer_length = 8;
796 	oob_port->write_urb->dev = port->serial->dev;
797 
798 	if ((ret = usb_submit_urb(oob_port->write_urb, GFP_ATOMIC)) == 0) {
799 		oob_priv->dp_write_urb_in_use = 1;
800 		port_priv->dp_modem_signals =
801 			(port_priv->dp_modem_signals&~(TIOCM_DTR|TIOCM_RTS))
802 			| (modem_signals&(TIOCM_DTR|TIOCM_RTS));
803 	}
804 	spin_unlock(&port_priv->dp_port_lock);
805 	spin_unlock_irqrestore(&oob_priv->dp_port_lock, flags);
806 	if (ret)
807 		err("%s: usb_submit_urb failed, ret=%d", __func__, ret);
808 	return ret;
809 }
810 
811 /*
812 *  Digi Transmit Idle
813 *
814 *  Digi transmit idle waits, up to timeout ticks, for the transmitter
815 *  to go idle.  It returns 0 if successful or a negative error.
816 *
817 *  There are race conditions here if more than one process is calling
818 *  digi_transmit_idle on the same port at the same time.  However, this
819 *  is only called from close, and only one process can be in close on a
820 *  port at a time, so its ok.
821 */
822 
823 static int digi_transmit_idle(struct usb_serial_port *port,
824 	unsigned long timeout)
825 {
826 	int ret;
827 	unsigned char buf[2];
828 	struct digi_port *priv = usb_get_serial_port_data(port);
829 	unsigned long flags = 0;
830 
831 	spin_lock_irqsave(&priv->dp_port_lock, flags);
832 	priv->dp_transmit_idle = 0;
833 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
834 
835 	buf[0] = DIGI_CMD_TRANSMIT_IDLE;
836 	buf[1] = 0;
837 
838 	timeout += jiffies;
839 
840 	if ((ret = digi_write_inb_command(port, buf, 2, timeout - jiffies)) != 0)
841 		return ret;
842 
843 	spin_lock_irqsave(&priv->dp_port_lock, flags);
844 
845 	while(time_before(jiffies, timeout) && !priv->dp_transmit_idle) {
846 		cond_wait_interruptible_timeout_irqrestore(
847 			&priv->dp_transmit_idle_wait, DIGI_RETRY_TIMEOUT,
848 			&priv->dp_port_lock, flags);
849 		if (signal_pending(current))
850 			return -EINTR;
851 		spin_lock_irqsave(&priv->dp_port_lock, flags);
852 	}
853 	priv->dp_transmit_idle = 0;
854 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
855 	return 0;
856 
857 }
858 
859 
860 static void digi_rx_throttle(struct usb_serial_port *port)
861 {
862 	unsigned long flags;
863 	struct digi_port *priv = usb_get_serial_port_data(port);
864 
865 
866 	dbg("digi_rx_throttle: TOP: port=%d", priv->dp_port_num);
867 
868 	/* stop receiving characters by not resubmitting the read urb */
869 	spin_lock_irqsave(&priv->dp_port_lock, flags);
870 	priv->dp_throttled = 1;
871 	priv->dp_throttle_restart = 0;
872 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
873 }
874 
875 
876 static void digi_rx_unthrottle(struct usb_serial_port *port)
877 {
878 	int ret = 0;
879 	unsigned long flags;
880 	struct digi_port *priv = usb_get_serial_port_data(port);
881 
882 	dbg("digi_rx_unthrottle: TOP: port=%d", priv->dp_port_num);
883 
884 	spin_lock_irqsave(&priv->dp_port_lock, flags);
885 
886 	/* turn throttle off */
887 	priv->dp_throttled = 0;
888 	priv->dp_throttle_restart = 0;
889 
890 	/* restart read chain */
891 	if (priv->dp_throttle_restart) {
892 		port->read_urb->dev = port->serial->dev;
893 		ret = usb_submit_urb(port->read_urb, GFP_ATOMIC);
894 	}
895 
896 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
897 
898 	if (ret)
899 		err("%s: usb_submit_urb failed, ret=%d, port=%d",
900 			__func__, ret, priv->dp_port_num);
901 }
902 
903 
904 static void digi_set_termios(struct usb_serial_port *port,
905 					struct ktermios *old_termios)
906 {
907 
908 	struct digi_port *priv = usb_get_serial_port_data(port);
909 	struct tty_struct *tty = port->tty;
910 	unsigned int iflag = tty->termios->c_iflag;
911 	unsigned int cflag = tty->termios->c_cflag;
912 	unsigned int old_iflag = old_termios->c_iflag;
913 	unsigned int old_cflag = old_termios->c_cflag;
914 	unsigned char buf[32];
915 	unsigned int modem_signals;
916 	int arg,ret;
917 	int i = 0;
918 	speed_t baud;
919 
920 	dbg("digi_set_termios: TOP: port=%d, iflag=0x%x, old_iflag=0x%x, cflag=0x%x, old_cflag=0x%x", priv->dp_port_num, iflag, old_iflag, cflag, old_cflag);
921 
922 	/* set baud rate */
923 	if ((baud = tty_get_baud_rate(tty)) != tty_termios_baud_rate(old_termios)) {
924 		arg = -1;
925 
926 		/* reassert DTR and (maybe) RTS on transition from B0 */
927 		if ((old_cflag&CBAUD) == B0) {
928 			/* don't set RTS if using hardware flow control */
929 			/* and throttling input */
930 			modem_signals = TIOCM_DTR;
931 			if (!(tty->termios->c_cflag & CRTSCTS) ||
932 			    !test_bit(TTY_THROTTLED, &tty->flags))
933 				modem_signals |= TIOCM_RTS;
934 			digi_set_modem_signals(port, modem_signals, 1);
935 		}
936 		switch (baud) {
937 			/* drop DTR and RTS on transition to B0 */
938 			case 0: digi_set_modem_signals(port, 0, 1); break;
939 			case 50: arg = DIGI_BAUD_50; break;
940 			case 75: arg = DIGI_BAUD_75; break;
941 			case 110: arg = DIGI_BAUD_110; break;
942 			case 150: arg = DIGI_BAUD_150; break;
943 			case 200: arg = DIGI_BAUD_200; break;
944 			case 300: arg = DIGI_BAUD_300; break;
945 			case 600: arg = DIGI_BAUD_600; break;
946 			case 1200: arg = DIGI_BAUD_1200; break;
947 			case 1800: arg = DIGI_BAUD_1800; break;
948 			case 2400: arg = DIGI_BAUD_2400; break;
949 			case 4800: arg = DIGI_BAUD_4800; break;
950 			case 9600: arg = DIGI_BAUD_9600; break;
951 			case 19200: arg = DIGI_BAUD_19200; break;
952 			case 38400: arg = DIGI_BAUD_38400; break;
953 			case 57600: arg = DIGI_BAUD_57600; break;
954 			case 115200: arg = DIGI_BAUD_115200; break;
955 			case 230400: arg = DIGI_BAUD_230400; break;
956 			case 460800: arg = DIGI_BAUD_460800; break;
957 			default:
958 				arg = DIGI_BAUD_9600;
959 				baud = 9600;
960 				break;
961 		}
962 		if (arg != -1) {
963 			buf[i++] = DIGI_CMD_SET_BAUD_RATE;
964 			buf[i++] = priv->dp_port_num;
965 			buf[i++] = arg;
966 			buf[i++] = 0;
967 		}
968 	}
969 	/* set parity */
970 	tty->termios->c_cflag &= ~CMSPAR;
971 
972 	if ((cflag&(PARENB|PARODD)) != (old_cflag&(PARENB|PARODD))) {
973 		if (cflag&PARENB) {
974 			if (cflag&PARODD)
975 				arg = DIGI_PARITY_ODD;
976 			else
977 				arg = DIGI_PARITY_EVEN;
978 		} else {
979 			arg = DIGI_PARITY_NONE;
980 		}
981 		buf[i++] = DIGI_CMD_SET_PARITY;
982 		buf[i++] = priv->dp_port_num;
983 		buf[i++] = arg;
984 		buf[i++] = 0;
985 	}
986 	/* set word size */
987 	if ((cflag&CSIZE) != (old_cflag&CSIZE)) {
988 		arg = -1;
989 		switch (cflag&CSIZE) {
990 		case CS5: arg = DIGI_WORD_SIZE_5; break;
991 		case CS6: arg = DIGI_WORD_SIZE_6; break;
992 		case CS7: arg = DIGI_WORD_SIZE_7; break;
993 		case CS8: arg = DIGI_WORD_SIZE_8; break;
994 		default:
995 			dbg("digi_set_termios: can't handle word size %d",
996 				(cflag&CSIZE));
997 			break;
998 		}
999 
1000 		if (arg != -1) {
1001 			buf[i++] = DIGI_CMD_SET_WORD_SIZE;
1002 			buf[i++] = priv->dp_port_num;
1003 			buf[i++] = arg;
1004 			buf[i++] = 0;
1005 		}
1006 
1007 	}
1008 
1009 	/* set stop bits */
1010 	if ((cflag&CSTOPB) != (old_cflag&CSTOPB)) {
1011 
1012 		if ((cflag&CSTOPB))
1013 			arg = DIGI_STOP_BITS_2;
1014 		else
1015 			arg = DIGI_STOP_BITS_1;
1016 
1017 		buf[i++] = DIGI_CMD_SET_STOP_BITS;
1018 		buf[i++] = priv->dp_port_num;
1019 		buf[i++] = arg;
1020 		buf[i++] = 0;
1021 
1022 	}
1023 
1024 	/* set input flow control */
1025 	if ((iflag&IXOFF) != (old_iflag&IXOFF)
1026 	    || (cflag&CRTSCTS) != (old_cflag&CRTSCTS)) {
1027 		arg = 0;
1028 		if (iflag&IXOFF)
1029 			arg |= DIGI_INPUT_FLOW_CONTROL_XON_XOFF;
1030 		else
1031 			arg &= ~DIGI_INPUT_FLOW_CONTROL_XON_XOFF;
1032 
1033 		if (cflag&CRTSCTS) {
1034 			arg |= DIGI_INPUT_FLOW_CONTROL_RTS;
1035 
1036 			/* On USB-4 it is necessary to assert RTS prior */
1037 			/* to selecting RTS input flow control.  */
1038 			buf[i++] = DIGI_CMD_SET_RTS_SIGNAL;
1039 			buf[i++] = priv->dp_port_num;
1040 			buf[i++] = DIGI_RTS_ACTIVE;
1041 			buf[i++] = 0;
1042 
1043 		} else {
1044 			arg &= ~DIGI_INPUT_FLOW_CONTROL_RTS;
1045 		}
1046 		buf[i++] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
1047 		buf[i++] = priv->dp_port_num;
1048 		buf[i++] = arg;
1049 		buf[i++] = 0;
1050 	}
1051 
1052 	/* set output flow control */
1053 	if ((iflag & IXON) != (old_iflag & IXON)
1054 	    || (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
1055 		arg = 0;
1056 		if (iflag & IXON)
1057 			arg |= DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF;
1058 		else
1059 			arg &= ~DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF;
1060 
1061 		if (cflag & CRTSCTS) {
1062 			arg |= DIGI_OUTPUT_FLOW_CONTROL_CTS;
1063 		} else {
1064 			arg &= ~DIGI_OUTPUT_FLOW_CONTROL_CTS;
1065 			tty->hw_stopped = 0;
1066 		}
1067 
1068 		buf[i++] = DIGI_CMD_SET_OUTPUT_FLOW_CONTROL;
1069 		buf[i++] = priv->dp_port_num;
1070 		buf[i++] = arg;
1071 		buf[i++] = 0;
1072 	}
1073 
1074 	/* set receive enable/disable */
1075 	if ((cflag & CREAD) != (old_cflag & CREAD)) {
1076 		if (cflag & CREAD)
1077 			arg = DIGI_ENABLE;
1078 		else
1079 			arg = DIGI_DISABLE;
1080 
1081 		buf[i++] = DIGI_CMD_RECEIVE_ENABLE;
1082 		buf[i++] = priv->dp_port_num;
1083 		buf[i++] = arg;
1084 		buf[i++] = 0;
1085 	}
1086 	if ((ret = digi_write_oob_command(port, buf, i, 1)) != 0)
1087 		dbg("digi_set_termios: write oob failed, ret=%d", ret);
1088 	tty_encode_baud_rate(tty, baud, baud);
1089 }
1090 
1091 
1092 static void digi_break_ctl(struct usb_serial_port *port, int break_state)
1093 {
1094 	unsigned char buf[4];
1095 
1096 	buf[0] = DIGI_CMD_BREAK_CONTROL;
1097 	buf[1] = 2;				/* length */
1098 	buf[2] = break_state ? 1 : 0;
1099 	buf[3] = 0;				/* pad */
1100 	digi_write_inb_command(port, buf, 4, 0);
1101 }
1102 
1103 
1104 static int digi_tiocmget(struct usb_serial_port *port, struct file *file)
1105 {
1106 	struct digi_port *priv = usb_get_serial_port_data(port);
1107 	unsigned int val;
1108 	unsigned long flags;
1109 
1110 	dbg("%s: TOP: port=%d", __func__, priv->dp_port_num);
1111 
1112 	spin_lock_irqsave(&priv->dp_port_lock, flags);
1113 	val = priv->dp_modem_signals;
1114 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1115 	return val;
1116 }
1117 
1118 
1119 static int digi_tiocmset(struct usb_serial_port *port, struct file *file,
1120 	unsigned int set, unsigned int clear)
1121 {
1122 	struct digi_port *priv = usb_get_serial_port_data(port);
1123 	unsigned int val;
1124 	unsigned long flags;
1125 
1126 	dbg("%s: TOP: port=%d", __func__, priv->dp_port_num);
1127 
1128 	spin_lock_irqsave(&priv->dp_port_lock, flags);
1129 	val = (priv->dp_modem_signals & ~clear) | set;
1130 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1131 	return digi_set_modem_signals(port, val, 1);
1132 }
1133 
1134 
1135 static int digi_ioctl(struct usb_serial_port *port, struct file *file,
1136 	unsigned int cmd, unsigned long arg)
1137 {
1138 	struct digi_port *priv = usb_get_serial_port_data(port);
1139 	dbg("digi_ioctl: TOP: port=%d, cmd=0x%x", priv->dp_port_num, cmd);
1140 
1141 	switch (cmd) {
1142 	case TIOCMIWAIT:
1143 		/* wait for any of the 4 modem inputs (DCD,RI,DSR,CTS)*/
1144 		/* TODO */
1145 		return 0;
1146 	case TIOCGICOUNT:
1147 		/* return count of modemline transitions */
1148 		/* TODO */
1149 		return 0;
1150 	}
1151 	return -ENOIOCTLCMD;
1152 
1153 }
1154 
1155 static int digi_write(struct usb_serial_port *port, const unsigned char *buf, int count)
1156 {
1157 
1158 	int ret,data_len,new_len;
1159 	struct digi_port *priv = usb_get_serial_port_data(port);
1160 	unsigned char *data = port->write_urb->transfer_buffer;
1161 	unsigned long flags = 0;
1162 
1163 	dbg("digi_write: TOP: port=%d, count=%d, in_interrupt=%ld",
1164 		priv->dp_port_num, count, in_interrupt());
1165 
1166 	/* copy user data (which can sleep) before getting spin lock */
1167 	count = min(count, port->bulk_out_size-2);
1168 	count = min(64, count);
1169 
1170 	/* be sure only one write proceeds at a time */
1171 	/* there are races on the port private buffer */
1172 	/* and races to check write_urb->status */
1173 	spin_lock_irqsave(&priv->dp_port_lock, flags);
1174 
1175 	/* wait for urb status clear to submit another urb */
1176 	if (port->write_urb->status == -EINPROGRESS || priv->dp_write_urb_in_use) {
1177 		/* buffer data if count is 1 (probably put_char) if possible */
1178 		if (count == 1 && priv->dp_out_buf_len < DIGI_OUT_BUF_SIZE) {
1179 			priv->dp_out_buf[priv->dp_out_buf_len++] = *buf;
1180 			new_len = 1;
1181 		} else {
1182 			new_len = 0;
1183 		}
1184 		spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1185 		return new_len;
1186 	}
1187 
1188 	/* allow space for any buffered data and for new data, up to */
1189 	/* transfer buffer size - 2 (for command and length bytes) */
1190 	new_len = min(count, port->bulk_out_size-2-priv->dp_out_buf_len);
1191 	data_len = new_len + priv->dp_out_buf_len;
1192 
1193 	if (data_len == 0) {
1194 		spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1195 		return 0;
1196 	}
1197 
1198 	port->write_urb->transfer_buffer_length = data_len+2;
1199 	port->write_urb->dev = port->serial->dev;
1200 
1201 	*data++ = DIGI_CMD_SEND_DATA;
1202 	*data++ = data_len;
1203 
1204 	/* copy in buffered data first */
1205 	memcpy(data, priv->dp_out_buf, priv->dp_out_buf_len);
1206 	data += priv->dp_out_buf_len;
1207 
1208 	/* copy in new data */
1209 	memcpy(data, buf, new_len);
1210 
1211 	if ((ret = usb_submit_urb(port->write_urb, GFP_ATOMIC)) == 0) {
1212 		priv->dp_write_urb_in_use = 1;
1213 		ret = new_len;
1214 		priv->dp_out_buf_len = 0;
1215 	}
1216 
1217 	/* return length of new data written, or error */
1218 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1219 	if (ret < 0)
1220 		err("%s: usb_submit_urb failed, ret=%d, port=%d",
1221 			__func__, ret, priv->dp_port_num);
1222 	dbg("digi_write: returning %d", ret);
1223 	return ret;
1224 
1225 }
1226 
1227 static void digi_write_bulk_callback(struct urb *urb)
1228 {
1229 
1230 	struct usb_serial_port *port = urb->context;
1231 	struct usb_serial *serial;
1232 	struct digi_port *priv;
1233 	struct digi_serial *serial_priv;
1234 	int ret = 0;
1235 	int status = urb->status;
1236 
1237 	dbg("digi_write_bulk_callback: TOP, urb->status=%d", status);
1238 
1239 	/* port and serial sanity check */
1240 	if (port == NULL || (priv=usb_get_serial_port_data(port)) == NULL) {
1241 		err("%s: port or port->private is NULL, status=%d",
1242 		    __func__, status);
1243 		return;
1244 	}
1245 	serial = port->serial;
1246 	if (serial == NULL || (serial_priv=usb_get_serial_data(serial)) == NULL) {
1247 		err("%s: serial or serial->private is NULL, status=%d",
1248 		    __func__, status);
1249 		return;
1250 	}
1251 
1252 	/* handle oob callback */
1253 	if (priv->dp_port_num == serial_priv->ds_oob_port_num) {
1254 		dbg("digi_write_bulk_callback: oob callback");
1255 		spin_lock(&priv->dp_port_lock);
1256 		priv->dp_write_urb_in_use = 0;
1257 		wake_up_interruptible(&port->write_wait);
1258 		spin_unlock(&priv->dp_port_lock);
1259 		return;
1260 	}
1261 
1262 	/* try to send any buffered data on this port, if it is open */
1263 	spin_lock(&priv->dp_port_lock);
1264 	priv->dp_write_urb_in_use = 0;
1265 	if (port->open_count && port->write_urb->status != -EINPROGRESS
1266 	    && priv->dp_out_buf_len > 0) {
1267 		*((unsigned char *)(port->write_urb->transfer_buffer))
1268 			= (unsigned char)DIGI_CMD_SEND_DATA;
1269 		*((unsigned char *)(port->write_urb->transfer_buffer)+1)
1270 			= (unsigned char)priv->dp_out_buf_len;
1271 		port->write_urb->transfer_buffer_length = priv->dp_out_buf_len+2;
1272 		port->write_urb->dev = serial->dev;
1273 		memcpy(port->write_urb->transfer_buffer+2, priv->dp_out_buf,
1274 			priv->dp_out_buf_len);
1275 		if ((ret = usb_submit_urb(port->write_urb, GFP_ATOMIC)) == 0) {
1276 			priv->dp_write_urb_in_use = 1;
1277 			priv->dp_out_buf_len = 0;
1278 		}
1279 	}
1280 	/* wake up processes sleeping on writes immediately */
1281 	digi_wakeup_write(port);
1282 	/* also queue up a wakeup at scheduler time, in case we */
1283 	/* lost the race in write_chan(). */
1284 	schedule_work(&priv->dp_wakeup_work);
1285 
1286 	spin_unlock(&priv->dp_port_lock);
1287 	if (ret)
1288 		err("%s: usb_submit_urb failed, ret=%d, port=%d",
1289 			__func__, ret, priv->dp_port_num);
1290 }
1291 
1292 static int digi_write_room(struct usb_serial_port *port)
1293 {
1294 
1295 	int room;
1296 	struct digi_port *priv = usb_get_serial_port_data(port);
1297 	unsigned long flags = 0;
1298 
1299 	spin_lock_irqsave(&priv->dp_port_lock, flags);
1300 
1301 	if (port->write_urb->status == -EINPROGRESS || priv->dp_write_urb_in_use)
1302 		room = 0;
1303 	else
1304 		room = port->bulk_out_size - 2 - priv->dp_out_buf_len;
1305 
1306 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1307 	dbg("digi_write_room: port=%d, room=%d", priv->dp_port_num, room);
1308 	return room;
1309 
1310 }
1311 
1312 static int digi_chars_in_buffer(struct usb_serial_port *port)
1313 {
1314 
1315 	struct digi_port *priv = usb_get_serial_port_data(port);
1316 
1317 
1318 	if (port->write_urb->status == -EINPROGRESS
1319 	    || priv->dp_write_urb_in_use) {
1320 		dbg("digi_chars_in_buffer: port=%d, chars=%d",
1321 			priv->dp_port_num, port->bulk_out_size - 2);
1322 		/* return(port->bulk_out_size - 2); */
1323 		return 256;
1324 	} else {
1325 		dbg("digi_chars_in_buffer: port=%d, chars=%d",
1326 			priv->dp_port_num, priv->dp_out_buf_len);
1327 		return priv->dp_out_buf_len;
1328 	}
1329 
1330 }
1331 
1332 
1333 static int digi_open(struct usb_serial_port *port, struct file *filp)
1334 {
1335 	int ret;
1336 	unsigned char buf[32];
1337 	struct digi_port *priv = usb_get_serial_port_data(port);
1338 	struct ktermios not_termios;
1339 	unsigned long flags = 0;
1340 
1341 	dbg("digi_open: TOP: port=%d, open_count=%d",
1342 		priv->dp_port_num, port->open_count);
1343 
1344 	/* be sure the device is started up */
1345 	if (digi_startup_device(port->serial) != 0)
1346 		return -ENXIO;
1347 
1348 	spin_lock_irqsave(&priv->dp_port_lock, flags);
1349 
1350 	/* don't wait on a close in progress for non-blocking opens */
1351 	if (priv->dp_in_close && (filp->f_flags&(O_NDELAY|O_NONBLOCK)) == 0) {
1352 		spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1353 		return -EAGAIN;
1354 	}
1355 
1356 	/* wait for a close in progress to finish */
1357 	while(priv->dp_in_close) {
1358 		cond_wait_interruptible_timeout_irqrestore(
1359 			&priv->dp_close_wait, DIGI_RETRY_TIMEOUT,
1360 			&priv->dp_port_lock, flags);
1361 		if (signal_pending(current))
1362 			return -EINTR;
1363 		spin_lock_irqsave(&priv->dp_port_lock, flags);
1364 	}
1365 
1366 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1367 
1368 	/* read modem signals automatically whenever they change */
1369 	buf[0] = DIGI_CMD_READ_INPUT_SIGNALS;
1370 	buf[1] = priv->dp_port_num;
1371 	buf[2] = DIGI_ENABLE;
1372 	buf[3] = 0;
1373 
1374 	/* flush fifos */
1375 	buf[4] = DIGI_CMD_IFLUSH_FIFO;
1376 	buf[5] = priv->dp_port_num;
1377 	buf[6] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
1378 	buf[7] = 0;
1379 
1380 	if ((ret = digi_write_oob_command(port, buf, 8, 1)) != 0)
1381 		dbg("digi_open: write oob failed, ret=%d", ret);
1382 
1383 	/* set termios settings */
1384 	not_termios.c_cflag = ~port->tty->termios->c_cflag;
1385 	not_termios.c_iflag = ~port->tty->termios->c_iflag;
1386 	digi_set_termios(port, &not_termios);
1387 
1388 	/* set DTR and RTS */
1389 	digi_set_modem_signals(port, TIOCM_DTR|TIOCM_RTS, 1);
1390 
1391 	return 0;
1392 }
1393 
1394 
1395 static void digi_close(struct usb_serial_port *port, struct file *filp)
1396 {
1397 	DEFINE_WAIT(wait);
1398 	int ret;
1399 	unsigned char buf[32];
1400 	struct tty_struct *tty = port->tty;
1401 	struct digi_port *priv = usb_get_serial_port_data(port);
1402 
1403 	dbg("digi_close: TOP: port=%d, open_count=%d",
1404 		priv->dp_port_num, port->open_count);
1405 
1406 	mutex_lock(&port->serial->disc_mutex);
1407 	/* if disconnected, just clear flags */
1408 	if (port->serial->disconnected)
1409 		goto exit;
1410 
1411 	/* do cleanup only after final close on this port */
1412 	spin_lock_irq(&priv->dp_port_lock);
1413 	priv->dp_in_close = 1;
1414 	spin_unlock_irq(&priv->dp_port_lock);
1415 
1416 	/* tell line discipline to process only XON/XOFF */
1417 	tty->closing = 1;
1418 
1419 	/* wait for output to drain */
1420 	if ((filp->f_flags&(O_NDELAY|O_NONBLOCK)) == 0)
1421 		tty_wait_until_sent(tty, DIGI_CLOSE_TIMEOUT);
1422 
1423 	/* flush driver and line discipline buffers */
1424 	tty_driver_flush_buffer(tty);
1425 	tty_ldisc_flush(tty);
1426 
1427 	if (port->serial->dev) {
1428 		/* wait for transmit idle */
1429 		if ((filp->f_flags&(O_NDELAY|O_NONBLOCK)) == 0) {
1430 			digi_transmit_idle(port, DIGI_CLOSE_TIMEOUT);
1431 		}
1432 		/* drop DTR and RTS */
1433 		digi_set_modem_signals(port, 0, 0);
1434 
1435 		/* disable input flow control */
1436 		buf[0] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
1437 		buf[1] = priv->dp_port_num;
1438 		buf[2] = DIGI_DISABLE;
1439 		buf[3] = 0;
1440 
1441 		/* disable output flow control */
1442 		buf[4] = DIGI_CMD_SET_OUTPUT_FLOW_CONTROL;
1443 		buf[5] = priv->dp_port_num;
1444 		buf[6] = DIGI_DISABLE;
1445 		buf[7] = 0;
1446 
1447 		/* disable reading modem signals automatically */
1448 		buf[8] = DIGI_CMD_READ_INPUT_SIGNALS;
1449 		buf[9] = priv->dp_port_num;
1450 		buf[10] = DIGI_DISABLE;
1451 		buf[11] = 0;
1452 
1453 		/* disable receive */
1454 		buf[12] = DIGI_CMD_RECEIVE_ENABLE;
1455 		buf[13] = priv->dp_port_num;
1456 		buf[14] = DIGI_DISABLE;
1457 		buf[15] = 0;
1458 
1459 		/* flush fifos */
1460 		buf[16] = DIGI_CMD_IFLUSH_FIFO;
1461 		buf[17] = priv->dp_port_num;
1462 		buf[18] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
1463 		buf[19] = 0;
1464 
1465 		if ((ret = digi_write_oob_command(port, buf, 20, 0)) != 0)
1466 			dbg("digi_close: write oob failed, ret=%d", ret);
1467 
1468 		/* wait for final commands on oob port to complete */
1469 		prepare_to_wait(&priv->dp_flush_wait, &wait, TASK_INTERRUPTIBLE);
1470 		schedule_timeout(DIGI_CLOSE_TIMEOUT);
1471 		finish_wait(&priv->dp_flush_wait, &wait);
1472 
1473 		/* shutdown any outstanding bulk writes */
1474 		usb_kill_urb(port->write_urb);
1475 	}
1476 	tty->closing = 0;
1477 exit:
1478 	spin_lock_irq(&priv->dp_port_lock);
1479 	priv->dp_write_urb_in_use = 0;
1480 	priv->dp_in_close = 0;
1481 	wake_up_interruptible(&priv->dp_close_wait);
1482 	spin_unlock_irq(&priv->dp_port_lock);
1483 	mutex_unlock(&port->serial->disc_mutex);
1484 	dbg("digi_close: done");
1485 }
1486 
1487 
1488 /*
1489 *  Digi Startup Device
1490 *
1491 *  Starts reads on all ports.  Must be called AFTER startup, with
1492 *  urbs initialized.  Returns 0 if successful, non-zero error otherwise.
1493 */
1494 
1495 static int digi_startup_device(struct usb_serial *serial)
1496 {
1497 	int i,ret = 0;
1498 	struct digi_serial *serial_priv = usb_get_serial_data(serial);
1499 	struct usb_serial_port *port;
1500 
1501 	/* be sure this happens exactly once */
1502 	spin_lock(&serial_priv->ds_serial_lock);
1503 	if (serial_priv->ds_device_started) {
1504 		spin_unlock(&serial_priv->ds_serial_lock);
1505 		return 0;
1506 	}
1507 	serial_priv->ds_device_started = 1;
1508 	spin_unlock(&serial_priv->ds_serial_lock);
1509 
1510 	/* start reading from each bulk in endpoint for the device */
1511 	/* set USB_DISABLE_SPD flag for write bulk urbs */
1512 	for (i = 0; i < serial->type->num_ports + 1; i++) {
1513 		port = serial->port[i];
1514 		port->write_urb->dev = port->serial->dev;
1515 		if ((ret = usb_submit_urb(port->read_urb, GFP_KERNEL)) != 0) {
1516 			err("%s: usb_submit_urb failed, ret=%d, port=%d",
1517 					__func__, ret, i);
1518 			break;
1519 		}
1520 	}
1521 	return ret;
1522 }
1523 
1524 
1525 static int digi_startup(struct usb_serial *serial)
1526 {
1527 
1528 	int i;
1529 	struct digi_port *priv;
1530 	struct digi_serial *serial_priv;
1531 
1532 	dbg("digi_startup: TOP");
1533 
1534 	/* allocate the private data structures for all ports */
1535 	/* number of regular ports + 1 for the out-of-band port */
1536 	for(i = 0; i < serial->type->num_ports + 1; i++) {
1537 		/* allocate port private structure */
1538 		priv = kmalloc(sizeof(struct digi_port), GFP_KERNEL);
1539 		if (priv == NULL) {
1540 			while (--i >= 0)
1541 				kfree(usb_get_serial_port_data(serial->port[i]));
1542 			return 1;			/* error */
1543 		}
1544 
1545 		/* initialize port private structure */
1546 		spin_lock_init(&priv->dp_port_lock);
1547 		priv->dp_port_num = i;
1548 		priv->dp_out_buf_len = 0;
1549 		priv->dp_write_urb_in_use = 0;
1550 		priv->dp_modem_signals = 0;
1551 		init_waitqueue_head(&priv->dp_modem_change_wait);
1552 		priv->dp_transmit_idle = 0;
1553 		init_waitqueue_head(&priv->dp_transmit_idle_wait);
1554 		priv->dp_throttled = 0;
1555 		priv->dp_throttle_restart = 0;
1556 		init_waitqueue_head(&priv->dp_flush_wait);
1557 		priv->dp_in_close = 0;
1558 		init_waitqueue_head(&priv->dp_close_wait);
1559 		INIT_WORK(&priv->dp_wakeup_work, digi_wakeup_write_lock);
1560 		priv->dp_port = serial->port[i];
1561 		/* initialize write wait queue for this port */
1562 		init_waitqueue_head(&serial->port[i]->write_wait);
1563 
1564 		usb_set_serial_port_data(serial->port[i], priv);
1565 	}
1566 
1567 	/* allocate serial private structure */
1568 	serial_priv = kmalloc(sizeof(struct digi_serial), GFP_KERNEL);
1569 	if (serial_priv == NULL) {
1570 		for (i = 0; i < serial->type->num_ports + 1; i++)
1571 			kfree(usb_get_serial_port_data(serial->port[i]));
1572 		return 1;			/* error */
1573 	}
1574 
1575 	/* initialize serial private structure */
1576 	spin_lock_init(&serial_priv->ds_serial_lock);
1577 	serial_priv->ds_oob_port_num = serial->type->num_ports;
1578 	serial_priv->ds_oob_port = serial->port[serial_priv->ds_oob_port_num];
1579 	serial_priv->ds_device_started = 0;
1580 	usb_set_serial_data(serial, serial_priv);
1581 
1582 	return 0;
1583 }
1584 
1585 
1586 static void digi_shutdown(struct usb_serial *serial)
1587 {
1588 	int i;
1589 	dbg("digi_shutdown: TOP, in_interrupt()=%ld", in_interrupt());
1590 
1591 	/* stop reads and writes on all ports */
1592 	for (i = 0; i < serial->type->num_ports + 1; i++) {
1593 		usb_kill_urb(serial->port[i]->read_urb);
1594 		usb_kill_urb(serial->port[i]->write_urb);
1595 	}
1596 
1597 	/* free the private data structures for all ports */
1598 	/* number of regular ports + 1 for the out-of-band port */
1599 	for(i = 0; i < serial->type->num_ports + 1; i++)
1600 		kfree(usb_get_serial_port_data(serial->port[i]));
1601 	kfree(usb_get_serial_data(serial));
1602 }
1603 
1604 
1605 static void digi_read_bulk_callback(struct urb *urb)
1606 {
1607 	struct usb_serial_port *port = urb->context;
1608 	struct digi_port *priv;
1609 	struct digi_serial *serial_priv;
1610 	int ret;
1611 	int status = urb->status;
1612 
1613 	dbg("digi_read_bulk_callback: TOP");
1614 
1615 	/* port sanity check, do not resubmit if port is not valid */
1616 	if (port == NULL || (priv = usb_get_serial_port_data(port)) == NULL) {
1617 		err("%s: port or port->private is NULL, status=%d",
1618 		    __func__, status);
1619 		return;
1620 	}
1621 	if (port->serial == NULL ||
1622 		(serial_priv=usb_get_serial_data(port->serial)) == NULL) {
1623 		err("%s: serial is bad or serial->private is NULL, status=%d",
1624 			__func__, status);
1625 		return;
1626 	}
1627 
1628 	/* do not resubmit urb if it has any status error */
1629 	if (status) {
1630 		err("%s: nonzero read bulk status: status=%d, port=%d",
1631 		    __func__, status, priv->dp_port_num);
1632 		return;
1633 	}
1634 
1635 	/* handle oob or inb callback, do not resubmit if error */
1636 	if (priv->dp_port_num == serial_priv->ds_oob_port_num) {
1637 		if (digi_read_oob_callback(urb) != 0)
1638 			return;
1639 	} else {
1640 		if (digi_read_inb_callback(urb) != 0)
1641 			return;
1642 	}
1643 
1644 	/* continue read */
1645 	urb->dev = port->serial->dev;
1646 	if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) != 0) {
1647 		err("%s: failed resubmitting urb, ret=%d, port=%d",
1648 		    __func__, ret, priv->dp_port_num);
1649 	}
1650 
1651 }
1652 
1653 /*
1654 *  Digi Read INB Callback
1655 *
1656 *  Digi Read INB Callback handles reads on the in band ports, sending
1657 *  the data on to the tty subsystem.  When called we know port and
1658 *  port->private are not NULL and port->serial has been validated.
1659 *  It returns 0 if successful, 1 if successful but the port is
1660 *  throttled, and -1 if the sanity checks failed.
1661 */
1662 
1663 static int digi_read_inb_callback(struct urb *urb)
1664 {
1665 
1666 	struct usb_serial_port *port = urb->context;
1667 	struct tty_struct *tty = port->tty;
1668 	struct digi_port *priv = usb_get_serial_port_data(port);
1669 	int opcode = ((unsigned char *)urb->transfer_buffer)[0];
1670 	int len = ((unsigned char *)urb->transfer_buffer)[1];
1671 	int port_status = ((unsigned char *)urb->transfer_buffer)[2];
1672 	unsigned char *data = ((unsigned char *)urb->transfer_buffer)+3;
1673 	int flag,throttled;
1674 	int i;
1675 	int status = urb->status;
1676 
1677 	/* do not process callbacks on closed ports */
1678 	/* but do continue the read chain */
1679 	if (port->open_count == 0)
1680 		return 0;
1681 
1682 	/* short/multiple packet check */
1683 	if (urb->actual_length != len + 2) {
1684      		err("%s: INCOMPLETE OR MULTIPLE PACKET, urb->status=%d, "
1685 		    "port=%d, opcode=%d, len=%d, actual_length=%d, "
1686 		    "status=%d", __func__, status, priv->dp_port_num,
1687 		    opcode, len, urb->actual_length, port_status);
1688 		return -1;
1689 	}
1690 
1691 	spin_lock(&priv->dp_port_lock);
1692 
1693 	/* check for throttle; if set, do not resubmit read urb */
1694 	/* indicate the read chain needs to be restarted on unthrottle */
1695 	throttled = priv->dp_throttled;
1696 	if (throttled)
1697 		priv->dp_throttle_restart = 1;
1698 
1699 	/* receive data */
1700 	if (opcode == DIGI_CMD_RECEIVE_DATA) {
1701 		/* get flag from port_status */
1702 		flag = 0;
1703 
1704 		/* overrun is special, not associated with a char */
1705 		if (port_status & DIGI_OVERRUN_ERROR)
1706 			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
1707 
1708 		/* break takes precedence over parity, */
1709 		/* which takes precedence over framing errors */
1710 		if (port_status & DIGI_BREAK_ERROR)
1711 			flag = TTY_BREAK;
1712 		else if (port_status & DIGI_PARITY_ERROR)
1713 			flag = TTY_PARITY;
1714 		else if (port_status & DIGI_FRAMING_ERROR)
1715 			flag = TTY_FRAME;
1716 
1717 		/* data length is len-1 (one byte of len is port_status) */
1718 		--len;
1719 
1720 		len = tty_buffer_request_room(tty, len);
1721 		if (len > 0) {
1722 			/* Hot path */
1723 			if (flag == TTY_NORMAL)
1724 				tty_insert_flip_string(tty, data, len);
1725 			else {
1726 				for(i = 0; i < len; i++)
1727 					tty_insert_flip_char(tty, data[i], flag);
1728 			}
1729 			tty_flip_buffer_push(tty);
1730 		}
1731 	}
1732 	spin_unlock(&priv->dp_port_lock);
1733 
1734 	if (opcode == DIGI_CMD_RECEIVE_DISABLE)
1735 		dbg("%s: got RECEIVE_DISABLE", __func__);
1736 	else if (opcode != DIGI_CMD_RECEIVE_DATA)
1737 		dbg("%s: unknown opcode: %d", __func__, opcode);
1738 
1739 	return(throttled ? 1 : 0);
1740 
1741 }
1742 
1743 
1744 /*
1745 *  Digi Read OOB Callback
1746 *
1747 *  Digi Read OOB Callback handles reads on the out of band port.
1748 *  When called we know port and port->private are not NULL and
1749 *  the port->serial is valid.  It returns 0 if successful, and
1750 *  -1 if the sanity checks failed.
1751 */
1752 
1753 static int digi_read_oob_callback(struct urb *urb)
1754 {
1755 
1756 	struct usb_serial_port *port = urb->context;
1757 	struct usb_serial *serial = port->serial;
1758 	struct digi_port *priv = usb_get_serial_port_data(port);
1759 	int opcode, line, status, val;
1760 	int i;
1761 
1762 	dbg("digi_read_oob_callback: port=%d, len=%d",
1763 			priv->dp_port_num, urb->actual_length);
1764 
1765 	/* handle each oob command */
1766 	for(i = 0; i < urb->actual_length - 3;) {
1767 		opcode = ((unsigned char *)urb->transfer_buffer)[i++];
1768 		line = ((unsigned char *)urb->transfer_buffer)[i++];
1769 		status = ((unsigned char *)urb->transfer_buffer)[i++];
1770 		val = ((unsigned char *)urb->transfer_buffer)[i++];
1771 
1772 		dbg("digi_read_oob_callback: opcode=%d, line=%d, status=%d, val=%d",
1773 			opcode, line, status, val);
1774 
1775 		if (status != 0 || line >= serial->type->num_ports)
1776 			continue;
1777 
1778 		port = serial->port[line];
1779 
1780 		if ((priv=usb_get_serial_port_data(port)) == NULL)
1781 			return -1;
1782 
1783 		if (opcode == DIGI_CMD_READ_INPUT_SIGNALS) {
1784 			spin_lock(&priv->dp_port_lock);
1785 			/* convert from digi flags to termiox flags */
1786 			if (val & DIGI_READ_INPUT_SIGNALS_CTS) {
1787 				priv->dp_modem_signals |= TIOCM_CTS;
1788 				/* port must be open to use tty struct */
1789 				if (port->open_count
1790 					&& port->tty->termios->c_cflag & CRTSCTS) {
1791 					port->tty->hw_stopped = 0;
1792 					digi_wakeup_write(port);
1793 				}
1794 			} else {
1795 				priv->dp_modem_signals &= ~TIOCM_CTS;
1796 				/* port must be open to use tty struct */
1797 				if (port->open_count
1798 					&& port->tty->termios->c_cflag & CRTSCTS) {
1799 					port->tty->hw_stopped = 1;
1800 				}
1801 			}
1802 			if (val & DIGI_READ_INPUT_SIGNALS_DSR)
1803 				priv->dp_modem_signals |= TIOCM_DSR;
1804 			else
1805 				priv->dp_modem_signals &= ~TIOCM_DSR;
1806 			if (val & DIGI_READ_INPUT_SIGNALS_RI)
1807 				priv->dp_modem_signals |= TIOCM_RI;
1808 			else
1809 				priv->dp_modem_signals &= ~TIOCM_RI;
1810 			if (val & DIGI_READ_INPUT_SIGNALS_DCD)
1811 				priv->dp_modem_signals |= TIOCM_CD;
1812 			else
1813 				priv->dp_modem_signals &= ~TIOCM_CD;
1814 
1815 			wake_up_interruptible(&priv->dp_modem_change_wait);
1816 			spin_unlock(&priv->dp_port_lock);
1817 		} else if (opcode == DIGI_CMD_TRANSMIT_IDLE) {
1818 			spin_lock(&priv->dp_port_lock);
1819 			priv->dp_transmit_idle = 1;
1820 			wake_up_interruptible(&priv->dp_transmit_idle_wait);
1821 			spin_unlock(&priv->dp_port_lock);
1822 		} else if (opcode == DIGI_CMD_IFLUSH_FIFO) {
1823 			wake_up_interruptible(&priv->dp_flush_wait);
1824 		}
1825 	}
1826 	return 0;
1827 
1828 }
1829 
1830 static int __init digi_init(void)
1831 {
1832 	int retval;
1833 	retval = usb_serial_register(&digi_acceleport_2_device);
1834 	if (retval)
1835 		goto failed_acceleport_2_device;
1836 	retval = usb_serial_register(&digi_acceleport_4_device);
1837 	if (retval)
1838 		goto failed_acceleport_4_device;
1839 	retval = usb_register(&digi_driver);
1840 	if (retval)
1841 		goto failed_usb_register;
1842 	info(DRIVER_VERSION ":" DRIVER_DESC);
1843 	return 0;
1844 failed_usb_register:
1845 	usb_serial_deregister(&digi_acceleport_4_device);
1846 failed_acceleport_4_device:
1847 	usb_serial_deregister(&digi_acceleport_2_device);
1848 failed_acceleport_2_device:
1849 	return retval;
1850 }
1851 
1852 static void __exit digi_exit (void)
1853 {
1854 	usb_deregister(&digi_driver);
1855 	usb_serial_deregister(&digi_acceleport_2_device);
1856 	usb_serial_deregister(&digi_acceleport_4_device);
1857 }
1858 
1859 
1860 module_init(digi_init);
1861 module_exit(digi_exit);
1862 
1863 
1864 MODULE_AUTHOR(DRIVER_AUTHOR);
1865 MODULE_DESCRIPTION(DRIVER_DESC);
1866 MODULE_LICENSE("GPL");
1867 
1868 module_param(debug, bool, S_IRUGO | S_IWUSR);
1869 MODULE_PARM_DESC(debug, "Debug enabled or not");
1870