1 // SPDX-License-Identifier: GPL-2.0+
3 * MCT (Magic Control Technology Corp.) USB RS232 Converter Driver
5 * Copyright (C) 2000 Wolfgang Grandegger (wolfgang@ces.ch)
7 * This program is largely derived from the Belkin USB Serial Adapter Driver
8 * (see belkin_sa.[ch]). All of the information about the device was acquired
9 * by using SniffUSB on Windows98. For technical details see mct_u232.h.
11 * William G. Greathouse and Greg Kroah-Hartman provided great help on how to
12 * do the reverse engineering and how to write a USB serial device driver.
14 * TO BE DONE, TO BE CHECKED:
15 * DTR/RTS signal handling may be incomplete or incorrect. I have mainly
16 * implemented what I have seen with SniffUSB or found in belkin_sa.c.
17 * For further TODOs check also belkin_sa.c.
20 #include <linux/kernel.h>
21 #include <linux/errno.h>
22 #include <linux/slab.h>
23 #include <linux/tty.h>
24 #include <linux/tty_driver.h>
25 #include <linux/tty_flip.h>
26 #include <linux/module.h>
27 #include <linux/spinlock.h>
28 #include <linux/uaccess.h>
29 #include <asm/unaligned.h>
30 #include <linux/usb.h>
31 #include <linux/usb/serial.h>
32 #include <linux/serial.h>
35 #define DRIVER_AUTHOR "Wolfgang Grandegger <wolfgang@ces.ch>"
36 #define DRIVER_DESC "Magic Control Technology USB-RS232 converter driver"
41 static int mct_u232_port_probe(struct usb_serial_port
*port
);
42 static int mct_u232_port_remove(struct usb_serial_port
*remove
);
43 static int mct_u232_open(struct tty_struct
*tty
, struct usb_serial_port
*port
);
44 static void mct_u232_close(struct usb_serial_port
*port
);
45 static void mct_u232_dtr_rts(struct usb_serial_port
*port
, int on
);
46 static void mct_u232_read_int_callback(struct urb
*urb
);
47 static void mct_u232_set_termios(struct tty_struct
*tty
,
48 struct usb_serial_port
*port
, struct ktermios
*old
);
49 static void mct_u232_break_ctl(struct tty_struct
*tty
, int break_state
);
50 static int mct_u232_tiocmget(struct tty_struct
*tty
);
51 static int mct_u232_tiocmset(struct tty_struct
*tty
,
52 unsigned int set
, unsigned int clear
);
53 static void mct_u232_throttle(struct tty_struct
*tty
);
54 static void mct_u232_unthrottle(struct tty_struct
*tty
);
58 * All of the device info needed for the MCT USB-RS232 converter.
60 static const struct usb_device_id id_table
[] = {
61 { USB_DEVICE(MCT_U232_VID
, MCT_U232_PID
) },
62 { USB_DEVICE(MCT_U232_VID
, MCT_U232_SITECOM_PID
) },
63 { USB_DEVICE(MCT_U232_VID
, MCT_U232_DU_H3SP_PID
) },
64 { USB_DEVICE(MCT_U232_BELKIN_F5U109_VID
, MCT_U232_BELKIN_F5U109_PID
) },
65 { } /* Terminating entry */
67 MODULE_DEVICE_TABLE(usb
, id_table
);
69 static struct usb_serial_driver mct_u232_device
= {
74 .description
= "MCT U232",
77 .open
= mct_u232_open
,
78 .close
= mct_u232_close
,
79 .dtr_rts
= mct_u232_dtr_rts
,
80 .throttle
= mct_u232_throttle
,
81 .unthrottle
= mct_u232_unthrottle
,
82 .read_int_callback
= mct_u232_read_int_callback
,
83 .set_termios
= mct_u232_set_termios
,
84 .break_ctl
= mct_u232_break_ctl
,
85 .tiocmget
= mct_u232_tiocmget
,
86 .tiocmset
= mct_u232_tiocmset
,
87 .tiocmiwait
= usb_serial_generic_tiocmiwait
,
88 .port_probe
= mct_u232_port_probe
,
89 .port_remove
= mct_u232_port_remove
,
90 .get_icount
= usb_serial_generic_get_icount
,
93 static struct usb_serial_driver
* const serial_drivers
[] = {
94 &mct_u232_device
, NULL
97 struct mct_u232_private
{
100 unsigned int control_state
; /* Modem Line Setting (TIOCM) */
101 unsigned char last_lcr
; /* Line Control Register */
102 unsigned char last_lsr
; /* Line Status Register */
103 unsigned char last_msr
; /* Modem Status Register */
104 unsigned int rx_flags
; /* Throttling flags */
107 #define THROTTLED 0x01
110 * Handle vendor specific USB requests
113 #define WDR_TIMEOUT 5000 /* default urb timeout */
116 * Later day 2.6.0-test kernels have new baud rates like B230400 which
117 * we do not know how to support. We ignore them for the moment.
119 static int mct_u232_calculate_baud_rate(struct usb_serial
*serial
,
120 speed_t value
, speed_t
*result
)
124 if (le16_to_cpu(serial
->dev
->descriptor
.idProduct
) == MCT_U232_SITECOM_PID
125 || le16_to_cpu(serial
->dev
->descriptor
.idProduct
) == MCT_U232_BELKIN_F5U109_PID
) {
130 return 0x02; /* this one not tested */
152 /* FIXME: Can we use any divider - should we do
153 divider = 115200/value;
154 real baud = 115200/divider */
174 static int mct_u232_set_baud_rate(struct tty_struct
*tty
,
175 struct usb_serial
*serial
, struct usb_serial_port
*port
, speed_t value
)
177 unsigned int divisor
;
180 unsigned char cts_enable_byte
= 0;
183 buf
= kmalloc(MCT_U232_MAX_SIZE
, GFP_KERNEL
);
187 divisor
= mct_u232_calculate_baud_rate(serial
, value
, &speed
);
188 put_unaligned_le32(divisor
, buf
);
189 rc
= usb_control_msg(serial
->dev
, usb_sndctrlpipe(serial
->dev
, 0),
190 MCT_U232_SET_BAUD_RATE_REQUEST
,
191 MCT_U232_SET_REQUEST_TYPE
,
192 0, 0, buf
, MCT_U232_SET_BAUD_RATE_SIZE
,
194 if (rc
< 0) /*FIXME: What value speed results */
195 dev_err(&port
->dev
, "Set BAUD RATE %d failed (error = %d)\n",
198 tty_encode_baud_rate(tty
, speed
, speed
);
199 dev_dbg(&port
->dev
, "set_baud_rate: value: 0x%x, divisor: 0x%x\n", value
, divisor
);
201 /* Mimic the MCT-supplied Windows driver (version 1.21P.0104), which
202 always sends two extra USB 'device request' messages after the
203 'baud rate change' message. The actual functionality of the
204 request codes in these messages is not fully understood but these
205 particular codes are never seen in any operation besides a baud
206 rate change. Both of these messages send a single byte of data.
207 In the first message, the value of this byte is always zero.
209 The second message has been determined experimentally to control
210 whether data will be transmitted to a device which is not asserting
211 the 'CTS' signal. If the second message's data byte is zero, data
212 will be transmitted even if 'CTS' is not asserted (i.e. no hardware
213 flow control). if the second message's data byte is nonzero (a
214 value of 1 is used by this driver), data will not be transmitted to
215 a device which is not asserting 'CTS'.
219 rc
= usb_control_msg(serial
->dev
, usb_sndctrlpipe(serial
->dev
, 0),
220 MCT_U232_SET_UNKNOWN1_REQUEST
,
221 MCT_U232_SET_REQUEST_TYPE
,
222 0, 0, buf
, MCT_U232_SET_UNKNOWN1_SIZE
,
225 dev_err(&port
->dev
, "Sending USB device request code %d "
226 "failed (error = %d)\n", MCT_U232_SET_UNKNOWN1_REQUEST
,
229 if (port
&& C_CRTSCTS(tty
))
232 dev_dbg(&port
->dev
, "set_baud_rate: send second control message, data = %02X\n",
234 buf
[0] = cts_enable_byte
;
235 rc
= usb_control_msg(serial
->dev
, usb_sndctrlpipe(serial
->dev
, 0),
236 MCT_U232_SET_CTS_REQUEST
,
237 MCT_U232_SET_REQUEST_TYPE
,
238 0, 0, buf
, MCT_U232_SET_CTS_SIZE
,
241 dev_err(&port
->dev
, "Sending USB device request code %d "
242 "failed (error = %d)\n", MCT_U232_SET_CTS_REQUEST
, rc
);
246 } /* mct_u232_set_baud_rate */
248 static int mct_u232_set_line_ctrl(struct usb_serial_port
*port
,
254 buf
= kmalloc(MCT_U232_MAX_SIZE
, GFP_KERNEL
);
259 rc
= usb_control_msg(port
->serial
->dev
, usb_sndctrlpipe(port
->serial
->dev
, 0),
260 MCT_U232_SET_LINE_CTRL_REQUEST
,
261 MCT_U232_SET_REQUEST_TYPE
,
262 0, 0, buf
, MCT_U232_SET_LINE_CTRL_SIZE
,
265 dev_err(&port
->dev
, "Set LINE CTRL 0x%x failed (error = %d)\n", lcr
, rc
);
266 dev_dbg(&port
->dev
, "set_line_ctrl: 0x%x\n", lcr
);
269 } /* mct_u232_set_line_ctrl */
271 static int mct_u232_set_modem_ctrl(struct usb_serial_port
*port
,
272 unsigned int control_state
)
278 buf
= kmalloc(MCT_U232_MAX_SIZE
, GFP_KERNEL
);
282 mcr
= MCT_U232_MCR_NONE
;
283 if (control_state
& TIOCM_DTR
)
284 mcr
|= MCT_U232_MCR_DTR
;
285 if (control_state
& TIOCM_RTS
)
286 mcr
|= MCT_U232_MCR_RTS
;
289 rc
= usb_control_msg(port
->serial
->dev
, usb_sndctrlpipe(port
->serial
->dev
, 0),
290 MCT_U232_SET_MODEM_CTRL_REQUEST
,
291 MCT_U232_SET_REQUEST_TYPE
,
292 0, 0, buf
, MCT_U232_SET_MODEM_CTRL_SIZE
,
296 dev_dbg(&port
->dev
, "set_modem_ctrl: state=0x%x ==> mcr=0x%x\n", control_state
, mcr
);
299 dev_err(&port
->dev
, "Set MODEM CTRL 0x%x failed (error = %d)\n", mcr
, rc
);
303 } /* mct_u232_set_modem_ctrl */
305 static int mct_u232_get_modem_stat(struct usb_serial_port
*port
,
311 buf
= kmalloc(MCT_U232_MAX_SIZE
, GFP_KERNEL
);
316 rc
= usb_control_msg(port
->serial
->dev
, usb_rcvctrlpipe(port
->serial
->dev
, 0),
317 MCT_U232_GET_MODEM_STAT_REQUEST
,
318 MCT_U232_GET_REQUEST_TYPE
,
319 0, 0, buf
, MCT_U232_GET_MODEM_STAT_SIZE
,
321 if (rc
< MCT_U232_GET_MODEM_STAT_SIZE
) {
322 dev_err(&port
->dev
, "Get MODEM STATus failed (error = %d)\n", rc
);
331 dev_dbg(&port
->dev
, "get_modem_stat: 0x%x\n", *msr
);
334 } /* mct_u232_get_modem_stat */
336 static void mct_u232_msr_to_icount(struct async_icount
*icount
,
339 /* Translate Control Line states */
340 if (msr
& MCT_U232_MSR_DDSR
)
342 if (msr
& MCT_U232_MSR_DCTS
)
344 if (msr
& MCT_U232_MSR_DRI
)
346 if (msr
& MCT_U232_MSR_DCD
)
348 } /* mct_u232_msr_to_icount */
350 static void mct_u232_msr_to_state(struct usb_serial_port
*port
,
351 unsigned int *control_state
, unsigned char msr
)
353 /* Translate Control Line states */
354 if (msr
& MCT_U232_MSR_DSR
)
355 *control_state
|= TIOCM_DSR
;
357 *control_state
&= ~TIOCM_DSR
;
358 if (msr
& MCT_U232_MSR_CTS
)
359 *control_state
|= TIOCM_CTS
;
361 *control_state
&= ~TIOCM_CTS
;
362 if (msr
& MCT_U232_MSR_RI
)
363 *control_state
|= TIOCM_RI
;
365 *control_state
&= ~TIOCM_RI
;
366 if (msr
& MCT_U232_MSR_CD
)
367 *control_state
|= TIOCM_CD
;
369 *control_state
&= ~TIOCM_CD
;
370 dev_dbg(&port
->dev
, "msr_to_state: msr=0x%x ==> state=0x%x\n", msr
, *control_state
);
371 } /* mct_u232_msr_to_state */
374 * Driver's tty interface functions
377 static int mct_u232_port_probe(struct usb_serial_port
*port
)
379 struct usb_serial
*serial
= port
->serial
;
380 struct mct_u232_private
*priv
;
382 /* check first to simplify error handling */
383 if (!serial
->port
[1] || !serial
->port
[1]->interrupt_in_urb
) {
384 dev_err(&port
->dev
, "expected endpoint missing\n");
388 priv
= kzalloc(sizeof(*priv
), GFP_KERNEL
);
392 /* Use second interrupt-in endpoint for reading. */
393 priv
->read_urb
= serial
->port
[1]->interrupt_in_urb
;
394 priv
->read_urb
->context
= port
;
396 spin_lock_init(&priv
->lock
);
398 usb_set_serial_port_data(port
, priv
);
403 static int mct_u232_port_remove(struct usb_serial_port
*port
)
405 struct mct_u232_private
*priv
;
407 priv
= usb_get_serial_port_data(port
);
413 static int mct_u232_open(struct tty_struct
*tty
, struct usb_serial_port
*port
)
415 struct usb_serial
*serial
= port
->serial
;
416 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
418 unsigned int control_state
;
420 unsigned char last_lcr
;
421 unsigned char last_msr
;
423 /* Compensate for a hardware bug: although the Sitecom U232-P25
424 * device reports a maximum output packet size of 32 bytes,
425 * it seems to be able to accept only 16 bytes (and that's what
426 * SniffUSB says too...)
428 if (le16_to_cpu(serial
->dev
->descriptor
.idProduct
)
429 == MCT_U232_SITECOM_PID
)
430 port
->bulk_out_size
= 16;
432 /* Do a defined restart: the normal serial device seems to
433 * always turn on DTR and RTS here, so do the same. I'm not
434 * sure if this is really necessary. But it should not harm
437 spin_lock_irqsave(&priv
->lock
, flags
);
438 if (tty
&& C_BAUD(tty
))
439 priv
->control_state
= TIOCM_DTR
| TIOCM_RTS
;
441 priv
->control_state
= 0;
443 priv
->last_lcr
= (MCT_U232_DATA_BITS_8
|
444 MCT_U232_PARITY_NONE
|
445 MCT_U232_STOP_BITS_1
);
446 control_state
= priv
->control_state
;
447 last_lcr
= priv
->last_lcr
;
448 spin_unlock_irqrestore(&priv
->lock
, flags
);
449 mct_u232_set_modem_ctrl(port
, control_state
);
450 mct_u232_set_line_ctrl(port
, last_lcr
);
452 /* Read modem status and update control state */
453 mct_u232_get_modem_stat(port
, &last_msr
);
454 spin_lock_irqsave(&priv
->lock
, flags
);
455 priv
->last_msr
= last_msr
;
456 mct_u232_msr_to_state(port
, &priv
->control_state
, priv
->last_msr
);
457 spin_unlock_irqrestore(&priv
->lock
, flags
);
459 retval
= usb_submit_urb(priv
->read_urb
, GFP_KERNEL
);
462 "usb_submit_urb(read) failed pipe 0x%x err %d\n",
463 port
->read_urb
->pipe
, retval
);
467 retval
= usb_submit_urb(port
->interrupt_in_urb
, GFP_KERNEL
);
469 usb_kill_urb(priv
->read_urb
);
471 "usb_submit_urb(read int) failed pipe 0x%x err %d",
472 port
->interrupt_in_urb
->pipe
, retval
);
479 } /* mct_u232_open */
481 static void mct_u232_dtr_rts(struct usb_serial_port
*port
, int on
)
483 unsigned int control_state
;
484 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
486 spin_lock_irq(&priv
->lock
);
488 priv
->control_state
|= TIOCM_DTR
| TIOCM_RTS
;
490 priv
->control_state
&= ~(TIOCM_DTR
| TIOCM_RTS
);
491 control_state
= priv
->control_state
;
492 spin_unlock_irq(&priv
->lock
);
494 mct_u232_set_modem_ctrl(port
, control_state
);
497 static void mct_u232_close(struct usb_serial_port
*port
)
499 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
501 usb_kill_urb(priv
->read_urb
);
502 usb_kill_urb(port
->interrupt_in_urb
);
504 usb_serial_generic_close(port
);
505 } /* mct_u232_close */
508 static void mct_u232_read_int_callback(struct urb
*urb
)
510 struct usb_serial_port
*port
= urb
->context
;
511 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
512 unsigned char *data
= urb
->transfer_buffer
;
514 int status
= urb
->status
;
524 /* this urb is terminated, clean up */
525 dev_dbg(&port
->dev
, "%s - urb shutting down with status: %d\n",
529 dev_dbg(&port
->dev
, "%s - nonzero urb status received: %d\n",
534 usb_serial_debug_data(&port
->dev
, __func__
, urb
->actual_length
, data
);
537 * Work-a-round: handle the 'usual' bulk-in pipe here
539 if (urb
->transfer_buffer_length
> 2) {
540 if (urb
->actual_length
) {
541 tty_insert_flip_string(&port
->port
, data
,
543 tty_flip_buffer_push(&port
->port
);
549 * The interrupt-in pipe signals exceptional conditions (modem line
550 * signal changes and errors). data[0] holds MSR, data[1] holds LSR.
552 spin_lock_irqsave(&priv
->lock
, flags
);
553 priv
->last_msr
= data
[MCT_U232_MSR_INDEX
];
555 /* Record Control Line states */
556 mct_u232_msr_to_state(port
, &priv
->control_state
, priv
->last_msr
);
558 mct_u232_msr_to_icount(&port
->icount
, priv
->last_msr
);
561 /* Not yet handled. See belkin_sa.c for further information */
562 /* Now to report any errors */
563 priv
->last_lsr
= data
[MCT_U232_LSR_INDEX
];
565 * fill in the flip buffer here, but I do not know the relation
566 * to the current/next receive buffer or characters. I need
567 * to look in to this before committing any code.
569 if (priv
->last_lsr
& MCT_U232_LSR_ERR
) {
570 tty
= tty_port_tty_get(&port
->port
);
572 if (priv
->last_lsr
& MCT_U232_LSR_OE
) {
575 if (priv
->last_lsr
& MCT_U232_LSR_PE
) {
578 if (priv
->last_lsr
& MCT_U232_LSR_FE
) {
580 /* Break Indicator */
581 if (priv
->last_lsr
& MCT_U232_LSR_BI
) {
586 wake_up_interruptible(&port
->port
.delta_msr_wait
);
587 spin_unlock_irqrestore(&priv
->lock
, flags
);
589 retval
= usb_submit_urb(urb
, GFP_ATOMIC
);
592 "%s - usb_submit_urb failed with result %d\n",
594 } /* mct_u232_read_int_callback */
596 static void mct_u232_set_termios(struct tty_struct
*tty
,
597 struct usb_serial_port
*port
,
598 struct ktermios
*old_termios
)
600 struct usb_serial
*serial
= port
->serial
;
601 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
602 struct ktermios
*termios
= &tty
->termios
;
603 unsigned int cflag
= termios
->c_cflag
;
604 unsigned int old_cflag
= old_termios
->c_cflag
;
606 unsigned int control_state
;
607 unsigned char last_lcr
;
609 /* get a local copy of the current port settings */
610 spin_lock_irqsave(&priv
->lock
, flags
);
611 control_state
= priv
->control_state
;
612 spin_unlock_irqrestore(&priv
->lock
, flags
);
617 * Do not attempt to cache old rates and skip settings,
618 * disconnects screw such tricks up completely.
619 * Premature optimization is the root of all evil.
622 /* reassert DTR and RTS on transition from B0 */
623 if ((old_cflag
& CBAUD
) == B0
) {
624 dev_dbg(&port
->dev
, "%s: baud was B0\n", __func__
);
625 control_state
|= TIOCM_DTR
| TIOCM_RTS
;
626 mct_u232_set_modem_ctrl(port
, control_state
);
629 mct_u232_set_baud_rate(tty
, serial
, port
, tty_get_baud_rate(tty
));
631 if ((cflag
& CBAUD
) == B0
) {
632 dev_dbg(&port
->dev
, "%s: baud is B0\n", __func__
);
633 /* Drop RTS and DTR */
634 control_state
&= ~(TIOCM_DTR
| TIOCM_RTS
);
635 mct_u232_set_modem_ctrl(port
, control_state
);
639 * Update line control register (LCR)
644 last_lcr
|= (cflag
& PARODD
) ?
645 MCT_U232_PARITY_ODD
: MCT_U232_PARITY_EVEN
;
647 last_lcr
|= MCT_U232_PARITY_NONE
;
649 /* set the number of data bits */
650 switch (cflag
& CSIZE
) {
652 last_lcr
|= MCT_U232_DATA_BITS_5
; break;
654 last_lcr
|= MCT_U232_DATA_BITS_6
; break;
656 last_lcr
|= MCT_U232_DATA_BITS_7
; break;
658 last_lcr
|= MCT_U232_DATA_BITS_8
; break;
661 "CSIZE was not CS5-CS8, using default of 8\n");
662 last_lcr
|= MCT_U232_DATA_BITS_8
;
666 termios
->c_cflag
&= ~CMSPAR
;
668 /* set the number of stop bits */
669 last_lcr
|= (cflag
& CSTOPB
) ?
670 MCT_U232_STOP_BITS_2
: MCT_U232_STOP_BITS_1
;
672 mct_u232_set_line_ctrl(port
, last_lcr
);
674 /* save off the modified port settings */
675 spin_lock_irqsave(&priv
->lock
, flags
);
676 priv
->control_state
= control_state
;
677 priv
->last_lcr
= last_lcr
;
678 spin_unlock_irqrestore(&priv
->lock
, flags
);
679 } /* mct_u232_set_termios */
681 static void mct_u232_break_ctl(struct tty_struct
*tty
, int break_state
)
683 struct usb_serial_port
*port
= tty
->driver_data
;
684 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
688 spin_lock_irqsave(&priv
->lock
, flags
);
689 lcr
= priv
->last_lcr
;
692 lcr
|= MCT_U232_SET_BREAK
;
693 spin_unlock_irqrestore(&priv
->lock
, flags
);
695 mct_u232_set_line_ctrl(port
, lcr
);
696 } /* mct_u232_break_ctl */
699 static int mct_u232_tiocmget(struct tty_struct
*tty
)
701 struct usb_serial_port
*port
= tty
->driver_data
;
702 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
703 unsigned int control_state
;
706 spin_lock_irqsave(&priv
->lock
, flags
);
707 control_state
= priv
->control_state
;
708 spin_unlock_irqrestore(&priv
->lock
, flags
);
710 return control_state
;
713 static int mct_u232_tiocmset(struct tty_struct
*tty
,
714 unsigned int set
, unsigned int clear
)
716 struct usb_serial_port
*port
= tty
->driver_data
;
717 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
718 unsigned int control_state
;
721 spin_lock_irqsave(&priv
->lock
, flags
);
722 control_state
= priv
->control_state
;
725 control_state
|= TIOCM_RTS
;
727 control_state
|= TIOCM_DTR
;
728 if (clear
& TIOCM_RTS
)
729 control_state
&= ~TIOCM_RTS
;
730 if (clear
& TIOCM_DTR
)
731 control_state
&= ~TIOCM_DTR
;
733 priv
->control_state
= control_state
;
734 spin_unlock_irqrestore(&priv
->lock
, flags
);
735 return mct_u232_set_modem_ctrl(port
, control_state
);
738 static void mct_u232_throttle(struct tty_struct
*tty
)
740 struct usb_serial_port
*port
= tty
->driver_data
;
741 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
742 unsigned int control_state
;
744 spin_lock_irq(&priv
->lock
);
745 priv
->rx_flags
|= THROTTLED
;
746 if (C_CRTSCTS(tty
)) {
747 priv
->control_state
&= ~TIOCM_RTS
;
748 control_state
= priv
->control_state
;
749 spin_unlock_irq(&priv
->lock
);
750 mct_u232_set_modem_ctrl(port
, control_state
);
752 spin_unlock_irq(&priv
->lock
);
756 static void mct_u232_unthrottle(struct tty_struct
*tty
)
758 struct usb_serial_port
*port
= tty
->driver_data
;
759 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
760 unsigned int control_state
;
762 spin_lock_irq(&priv
->lock
);
763 if ((priv
->rx_flags
& THROTTLED
) && C_CRTSCTS(tty
)) {
764 priv
->rx_flags
&= ~THROTTLED
;
765 priv
->control_state
|= TIOCM_RTS
;
766 control_state
= priv
->control_state
;
767 spin_unlock_irq(&priv
->lock
);
768 mct_u232_set_modem_ctrl(port
, control_state
);
770 spin_unlock_irq(&priv
->lock
);
774 module_usb_serial_driver(serial_drivers
, id_table
);
776 MODULE_AUTHOR(DRIVER_AUTHOR
);
777 MODULE_DESCRIPTION(DRIVER_DESC
);
778 MODULE_LICENSE("GPL");