2 * MCT (Magic Control Technology Corp.) USB RS232 Converter Driver
4 * Copyright (C) 2000 Wolfgang Grandegger (wolfgang@ces.ch)
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.
11 * This program is largely derived from the Belkin USB Serial Adapter Driver
12 * (see belkin_sa.[ch]). All of the information about the device was acquired
13 * by using SniffUSB on Windows98. For technical details see mct_u232.h.
15 * William G. Greathouse and Greg Kroah-Hartman provided great help on how to
16 * do the reverse engineering and how to write a USB serial device driver.
18 * TO BE DONE, TO BE CHECKED:
19 * DTR/RTS signal handling may be incomplete or incorrect. I have mainly
20 * implemented what I have seen with SniffUSB or found in belkin_sa.c.
21 * For further TODOs check also belkin_sa.c.
24 #include <linux/kernel.h>
25 #include <linux/errno.h>
26 #include <linux/slab.h>
27 #include <linux/tty.h>
28 #include <linux/tty_driver.h>
29 #include <linux/tty_flip.h>
30 #include <linux/module.h>
31 #include <linux/spinlock.h>
32 #include <linux/uaccess.h>
33 #include <asm/unaligned.h>
34 #include <linux/usb.h>
35 #include <linux/usb/serial.h>
36 #include <linux/serial.h>
39 #define DRIVER_AUTHOR "Wolfgang Grandegger <wolfgang@ces.ch>"
40 #define DRIVER_DESC "Magic Control Technology USB-RS232 converter driver"
45 static int mct_u232_port_probe(struct usb_serial_port
*port
);
46 static int mct_u232_port_remove(struct usb_serial_port
*remove
);
47 static int mct_u232_open(struct tty_struct
*tty
, struct usb_serial_port
*port
);
48 static void mct_u232_close(struct usb_serial_port
*port
);
49 static void mct_u232_dtr_rts(struct usb_serial_port
*port
, int on
);
50 static void mct_u232_read_int_callback(struct urb
*urb
);
51 static void mct_u232_set_termios(struct tty_struct
*tty
,
52 struct usb_serial_port
*port
, struct ktermios
*old
);
53 static void mct_u232_break_ctl(struct tty_struct
*tty
, int break_state
);
54 static int mct_u232_tiocmget(struct tty_struct
*tty
);
55 static int mct_u232_tiocmset(struct tty_struct
*tty
,
56 unsigned int set
, unsigned int clear
);
57 static void mct_u232_throttle(struct tty_struct
*tty
);
58 static void mct_u232_unthrottle(struct tty_struct
*tty
);
62 * All of the device info needed for the MCT USB-RS232 converter.
64 static const struct usb_device_id id_table
[] = {
65 { USB_DEVICE(MCT_U232_VID
, MCT_U232_PID
) },
66 { USB_DEVICE(MCT_U232_VID
, MCT_U232_SITECOM_PID
) },
67 { USB_DEVICE(MCT_U232_VID
, MCT_U232_DU_H3SP_PID
) },
68 { USB_DEVICE(MCT_U232_BELKIN_F5U109_VID
, MCT_U232_BELKIN_F5U109_PID
) },
69 { } /* Terminating entry */
71 MODULE_DEVICE_TABLE(usb
, id_table
);
73 static struct usb_serial_driver mct_u232_device
= {
78 .description
= "MCT U232",
81 .open
= mct_u232_open
,
82 .close
= mct_u232_close
,
83 .dtr_rts
= mct_u232_dtr_rts
,
84 .throttle
= mct_u232_throttle
,
85 .unthrottle
= mct_u232_unthrottle
,
86 .read_int_callback
= mct_u232_read_int_callback
,
87 .set_termios
= mct_u232_set_termios
,
88 .break_ctl
= mct_u232_break_ctl
,
89 .tiocmget
= mct_u232_tiocmget
,
90 .tiocmset
= mct_u232_tiocmset
,
91 .tiocmiwait
= usb_serial_generic_tiocmiwait
,
92 .port_probe
= mct_u232_port_probe
,
93 .port_remove
= mct_u232_port_remove
,
94 .get_icount
= usb_serial_generic_get_icount
,
97 static struct usb_serial_driver
* const serial_drivers
[] = {
98 &mct_u232_device
, NULL
101 struct mct_u232_private
{
102 struct urb
*read_urb
;
104 unsigned int control_state
; /* Modem Line Setting (TIOCM) */
105 unsigned char last_lcr
; /* Line Control Register */
106 unsigned char last_lsr
; /* Line Status Register */
107 unsigned char last_msr
; /* Modem Status Register */
108 unsigned int rx_flags
; /* Throttling flags */
111 #define THROTTLED 0x01
114 * Handle vendor specific USB requests
117 #define WDR_TIMEOUT 5000 /* default urb timeout */
120 * Later day 2.6.0-test kernels have new baud rates like B230400 which
121 * we do not know how to support. We ignore them for the moment.
123 static int mct_u232_calculate_baud_rate(struct usb_serial
*serial
,
124 speed_t value
, speed_t
*result
)
128 if (le16_to_cpu(serial
->dev
->descriptor
.idProduct
) == MCT_U232_SITECOM_PID
129 || le16_to_cpu(serial
->dev
->descriptor
.idProduct
) == MCT_U232_BELKIN_F5U109_PID
) {
134 return 0x02; /* this one not tested */
156 /* FIXME: Can we use any divider - should we do
157 divider = 115200/value;
158 real baud = 115200/divider */
178 static int mct_u232_set_baud_rate(struct tty_struct
*tty
,
179 struct usb_serial
*serial
, struct usb_serial_port
*port
, speed_t value
)
181 unsigned int divisor
;
184 unsigned char cts_enable_byte
= 0;
187 buf
= kmalloc(MCT_U232_MAX_SIZE
, GFP_KERNEL
);
191 divisor
= mct_u232_calculate_baud_rate(serial
, value
, &speed
);
192 put_unaligned_le32(cpu_to_le32(divisor
), buf
);
193 rc
= usb_control_msg(serial
->dev
, usb_sndctrlpipe(serial
->dev
, 0),
194 MCT_U232_SET_BAUD_RATE_REQUEST
,
195 MCT_U232_SET_REQUEST_TYPE
,
196 0, 0, buf
, MCT_U232_SET_BAUD_RATE_SIZE
,
198 if (rc
< 0) /*FIXME: What value speed results */
199 dev_err(&port
->dev
, "Set BAUD RATE %d failed (error = %d)\n",
202 tty_encode_baud_rate(tty
, speed
, speed
);
203 dev_dbg(&port
->dev
, "set_baud_rate: value: 0x%x, divisor: 0x%x\n", value
, divisor
);
205 /* Mimic the MCT-supplied Windows driver (version 1.21P.0104), which
206 always sends two extra USB 'device request' messages after the
207 'baud rate change' message. The actual functionality of the
208 request codes in these messages is not fully understood but these
209 particular codes are never seen in any operation besides a baud
210 rate change. Both of these messages send a single byte of data.
211 In the first message, the value of this byte is always zero.
213 The second message has been determined experimentally to control
214 whether data will be transmitted to a device which is not asserting
215 the 'CTS' signal. If the second message's data byte is zero, data
216 will be transmitted even if 'CTS' is not asserted (i.e. no hardware
217 flow control). if the second message's data byte is nonzero (a
218 value of 1 is used by this driver), data will not be transmitted to
219 a device which is not asserting 'CTS'.
223 rc
= usb_control_msg(serial
->dev
, usb_sndctrlpipe(serial
->dev
, 0),
224 MCT_U232_SET_UNKNOWN1_REQUEST
,
225 MCT_U232_SET_REQUEST_TYPE
,
226 0, 0, buf
, MCT_U232_SET_UNKNOWN1_SIZE
,
229 dev_err(&port
->dev
, "Sending USB device request code %d "
230 "failed (error = %d)\n", MCT_U232_SET_UNKNOWN1_REQUEST
,
233 if (port
&& C_CRTSCTS(tty
))
236 dev_dbg(&port
->dev
, "set_baud_rate: send second control message, data = %02X\n",
238 buf
[0] = cts_enable_byte
;
239 rc
= usb_control_msg(serial
->dev
, usb_sndctrlpipe(serial
->dev
, 0),
240 MCT_U232_SET_CTS_REQUEST
,
241 MCT_U232_SET_REQUEST_TYPE
,
242 0, 0, buf
, MCT_U232_SET_CTS_SIZE
,
245 dev_err(&port
->dev
, "Sending USB device request code %d "
246 "failed (error = %d)\n", MCT_U232_SET_CTS_REQUEST
, rc
);
250 } /* mct_u232_set_baud_rate */
252 static int mct_u232_set_line_ctrl(struct usb_serial_port
*port
,
258 buf
= kmalloc(MCT_U232_MAX_SIZE
, GFP_KERNEL
);
263 rc
= usb_control_msg(port
->serial
->dev
, usb_sndctrlpipe(port
->serial
->dev
, 0),
264 MCT_U232_SET_LINE_CTRL_REQUEST
,
265 MCT_U232_SET_REQUEST_TYPE
,
266 0, 0, buf
, MCT_U232_SET_LINE_CTRL_SIZE
,
269 dev_err(&port
->dev
, "Set LINE CTRL 0x%x failed (error = %d)\n", lcr
, rc
);
270 dev_dbg(&port
->dev
, "set_line_ctrl: 0x%x\n", lcr
);
273 } /* mct_u232_set_line_ctrl */
275 static int mct_u232_set_modem_ctrl(struct usb_serial_port
*port
,
276 unsigned int control_state
)
282 buf
= kmalloc(MCT_U232_MAX_SIZE
, GFP_KERNEL
);
286 mcr
= MCT_U232_MCR_NONE
;
287 if (control_state
& TIOCM_DTR
)
288 mcr
|= MCT_U232_MCR_DTR
;
289 if (control_state
& TIOCM_RTS
)
290 mcr
|= MCT_U232_MCR_RTS
;
293 rc
= usb_control_msg(port
->serial
->dev
, usb_sndctrlpipe(port
->serial
->dev
, 0),
294 MCT_U232_SET_MODEM_CTRL_REQUEST
,
295 MCT_U232_SET_REQUEST_TYPE
,
296 0, 0, buf
, MCT_U232_SET_MODEM_CTRL_SIZE
,
300 dev_dbg(&port
->dev
, "set_modem_ctrl: state=0x%x ==> mcr=0x%x\n", control_state
, mcr
);
303 dev_err(&port
->dev
, "Set MODEM CTRL 0x%x failed (error = %d)\n", mcr
, rc
);
307 } /* mct_u232_set_modem_ctrl */
309 static int mct_u232_get_modem_stat(struct usb_serial_port
*port
,
315 buf
= kmalloc(MCT_U232_MAX_SIZE
, GFP_KERNEL
);
320 rc
= usb_control_msg(port
->serial
->dev
, usb_rcvctrlpipe(port
->serial
->dev
, 0),
321 MCT_U232_GET_MODEM_STAT_REQUEST
,
322 MCT_U232_GET_REQUEST_TYPE
,
323 0, 0, buf
, MCT_U232_GET_MODEM_STAT_SIZE
,
326 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 mct_u232_private
*priv
;
381 priv
= kzalloc(sizeof(*priv
), GFP_KERNEL
);
385 /* Use second interrupt-in endpoint for reading. */
386 priv
->read_urb
= port
->serial
->port
[1]->interrupt_in_urb
;
387 priv
->read_urb
->context
= port
;
389 spin_lock_init(&priv
->lock
);
391 usb_set_serial_port_data(port
, priv
);
396 static int mct_u232_port_remove(struct usb_serial_port
*port
)
398 struct mct_u232_private
*priv
;
400 priv
= usb_get_serial_port_data(port
);
406 static int mct_u232_open(struct tty_struct
*tty
, struct usb_serial_port
*port
)
408 struct usb_serial
*serial
= port
->serial
;
409 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
411 unsigned int control_state
;
413 unsigned char last_lcr
;
414 unsigned char last_msr
;
416 /* Compensate for a hardware bug: although the Sitecom U232-P25
417 * device reports a maximum output packet size of 32 bytes,
418 * it seems to be able to accept only 16 bytes (and that's what
419 * SniffUSB says too...)
421 if (le16_to_cpu(serial
->dev
->descriptor
.idProduct
)
422 == MCT_U232_SITECOM_PID
)
423 port
->bulk_out_size
= 16;
425 /* Do a defined restart: the normal serial device seems to
426 * always turn on DTR and RTS here, so do the same. I'm not
427 * sure if this is really necessary. But it should not harm
430 spin_lock_irqsave(&priv
->lock
, flags
);
431 if (tty
&& (tty
->termios
.c_cflag
& CBAUD
))
432 priv
->control_state
= TIOCM_DTR
| TIOCM_RTS
;
434 priv
->control_state
= 0;
436 priv
->last_lcr
= (MCT_U232_DATA_BITS_8
|
437 MCT_U232_PARITY_NONE
|
438 MCT_U232_STOP_BITS_1
);
439 control_state
= priv
->control_state
;
440 last_lcr
= priv
->last_lcr
;
441 spin_unlock_irqrestore(&priv
->lock
, flags
);
442 mct_u232_set_modem_ctrl(port
, control_state
);
443 mct_u232_set_line_ctrl(port
, last_lcr
);
445 /* Read modem status and update control state */
446 mct_u232_get_modem_stat(port
, &last_msr
);
447 spin_lock_irqsave(&priv
->lock
, flags
);
448 priv
->last_msr
= last_msr
;
449 mct_u232_msr_to_state(port
, &priv
->control_state
, priv
->last_msr
);
450 spin_unlock_irqrestore(&priv
->lock
, flags
);
452 retval
= usb_submit_urb(priv
->read_urb
, GFP_KERNEL
);
455 "usb_submit_urb(read) failed pipe 0x%x err %d\n",
456 port
->read_urb
->pipe
, retval
);
460 retval
= usb_submit_urb(port
->interrupt_in_urb
, GFP_KERNEL
);
462 usb_kill_urb(priv
->read_urb
);
464 "usb_submit_urb(read int) failed pipe 0x%x err %d",
465 port
->interrupt_in_urb
->pipe
, retval
);
472 } /* mct_u232_open */
474 static void mct_u232_dtr_rts(struct usb_serial_port
*port
, int on
)
476 unsigned int control_state
;
477 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
479 spin_lock_irq(&priv
->lock
);
481 priv
->control_state
|= TIOCM_DTR
| TIOCM_RTS
;
483 priv
->control_state
&= ~(TIOCM_DTR
| TIOCM_RTS
);
484 control_state
= priv
->control_state
;
485 spin_unlock_irq(&priv
->lock
);
487 mct_u232_set_modem_ctrl(port
, control_state
);
490 static void mct_u232_close(struct usb_serial_port
*port
)
492 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
494 usb_kill_urb(priv
->read_urb
);
495 usb_kill_urb(port
->interrupt_in_urb
);
497 usb_serial_generic_close(port
);
498 } /* mct_u232_close */
501 static void mct_u232_read_int_callback(struct urb
*urb
)
503 struct usb_serial_port
*port
= urb
->context
;
504 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
505 unsigned char *data
= urb
->transfer_buffer
;
507 int status
= urb
->status
;
517 /* this urb is terminated, clean up */
518 dev_dbg(&port
->dev
, "%s - urb shutting down with status: %d\n",
522 dev_dbg(&port
->dev
, "%s - nonzero urb status received: %d\n",
527 usb_serial_debug_data(&port
->dev
, __func__
, urb
->actual_length
, data
);
530 * Work-a-round: handle the 'usual' bulk-in pipe here
532 if (urb
->transfer_buffer_length
> 2) {
533 if (urb
->actual_length
) {
534 tty_insert_flip_string(&port
->port
, data
,
536 tty_flip_buffer_push(&port
->port
);
542 * The interrupt-in pipe signals exceptional conditions (modem line
543 * signal changes and errors). data[0] holds MSR, data[1] holds LSR.
545 spin_lock_irqsave(&priv
->lock
, flags
);
546 priv
->last_msr
= data
[MCT_U232_MSR_INDEX
];
548 /* Record Control Line states */
549 mct_u232_msr_to_state(port
, &priv
->control_state
, priv
->last_msr
);
551 mct_u232_msr_to_icount(&port
->icount
, priv
->last_msr
);
554 /* Not yet handled. See belkin_sa.c for further information */
555 /* Now to report any errors */
556 priv
->last_lsr
= data
[MCT_U232_LSR_INDEX
];
558 * fill in the flip buffer here, but I do not know the relation
559 * to the current/next receive buffer or characters. I need
560 * to look in to this before committing any code.
562 if (priv
->last_lsr
& MCT_U232_LSR_ERR
) {
563 tty
= tty_port_tty_get(&port
->port
);
565 if (priv
->last_lsr
& MCT_U232_LSR_OE
) {
568 if (priv
->last_lsr
& MCT_U232_LSR_PE
) {
571 if (priv
->last_lsr
& MCT_U232_LSR_FE
) {
573 /* Break Indicator */
574 if (priv
->last_lsr
& MCT_U232_LSR_BI
) {
579 wake_up_interruptible(&port
->port
.delta_msr_wait
);
580 spin_unlock_irqrestore(&priv
->lock
, flags
);
582 retval
= usb_submit_urb(urb
, GFP_ATOMIC
);
585 "%s - usb_submit_urb failed with result %d\n",
587 } /* mct_u232_read_int_callback */
589 static void mct_u232_set_termios(struct tty_struct
*tty
,
590 struct usb_serial_port
*port
,
591 struct ktermios
*old_termios
)
593 struct usb_serial
*serial
= port
->serial
;
594 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
595 struct ktermios
*termios
= &tty
->termios
;
596 unsigned int cflag
= termios
->c_cflag
;
597 unsigned int old_cflag
= old_termios
->c_cflag
;
599 unsigned int control_state
;
600 unsigned char last_lcr
;
602 /* get a local copy of the current port settings */
603 spin_lock_irqsave(&priv
->lock
, flags
);
604 control_state
= priv
->control_state
;
605 spin_unlock_irqrestore(&priv
->lock
, flags
);
610 * Do not attempt to cache old rates and skip settings,
611 * disconnects screw such tricks up completely.
612 * Premature optimization is the root of all evil.
615 /* reassert DTR and RTS on transition from B0 */
616 if ((old_cflag
& CBAUD
) == B0
) {
617 dev_dbg(&port
->dev
, "%s: baud was B0\n", __func__
);
618 control_state
|= TIOCM_DTR
| TIOCM_RTS
;
619 mct_u232_set_modem_ctrl(port
, control_state
);
622 mct_u232_set_baud_rate(tty
, serial
, port
, tty_get_baud_rate(tty
));
624 if ((cflag
& CBAUD
) == B0
) {
625 dev_dbg(&port
->dev
, "%s: baud is B0\n", __func__
);
626 /* Drop RTS and DTR */
627 control_state
&= ~(TIOCM_DTR
| TIOCM_RTS
);
628 mct_u232_set_modem_ctrl(port
, control_state
);
632 * Update line control register (LCR)
637 last_lcr
|= (cflag
& PARODD
) ?
638 MCT_U232_PARITY_ODD
: MCT_U232_PARITY_EVEN
;
640 last_lcr
|= MCT_U232_PARITY_NONE
;
642 /* set the number of data bits */
643 switch (cflag
& CSIZE
) {
645 last_lcr
|= MCT_U232_DATA_BITS_5
; break;
647 last_lcr
|= MCT_U232_DATA_BITS_6
; break;
649 last_lcr
|= MCT_U232_DATA_BITS_7
; break;
651 last_lcr
|= MCT_U232_DATA_BITS_8
; break;
654 "CSIZE was not CS5-CS8, using default of 8\n");
655 last_lcr
|= MCT_U232_DATA_BITS_8
;
659 termios
->c_cflag
&= ~CMSPAR
;
661 /* set the number of stop bits */
662 last_lcr
|= (cflag
& CSTOPB
) ?
663 MCT_U232_STOP_BITS_2
: MCT_U232_STOP_BITS_1
;
665 mct_u232_set_line_ctrl(port
, last_lcr
);
667 /* save off the modified port settings */
668 spin_lock_irqsave(&priv
->lock
, flags
);
669 priv
->control_state
= control_state
;
670 priv
->last_lcr
= last_lcr
;
671 spin_unlock_irqrestore(&priv
->lock
, flags
);
672 } /* mct_u232_set_termios */
674 static void mct_u232_break_ctl(struct tty_struct
*tty
, int break_state
)
676 struct usb_serial_port
*port
= tty
->driver_data
;
677 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
681 spin_lock_irqsave(&priv
->lock
, flags
);
682 lcr
= priv
->last_lcr
;
685 lcr
|= MCT_U232_SET_BREAK
;
686 spin_unlock_irqrestore(&priv
->lock
, flags
);
688 mct_u232_set_line_ctrl(port
, lcr
);
689 } /* mct_u232_break_ctl */
692 static int mct_u232_tiocmget(struct tty_struct
*tty
)
694 struct usb_serial_port
*port
= tty
->driver_data
;
695 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
696 unsigned int control_state
;
699 spin_lock_irqsave(&priv
->lock
, flags
);
700 control_state
= priv
->control_state
;
701 spin_unlock_irqrestore(&priv
->lock
, flags
);
703 return control_state
;
706 static int mct_u232_tiocmset(struct tty_struct
*tty
,
707 unsigned int set
, unsigned int clear
)
709 struct usb_serial_port
*port
= tty
->driver_data
;
710 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
711 unsigned int control_state
;
714 spin_lock_irqsave(&priv
->lock
, flags
);
715 control_state
= priv
->control_state
;
718 control_state
|= TIOCM_RTS
;
720 control_state
|= TIOCM_DTR
;
721 if (clear
& TIOCM_RTS
)
722 control_state
&= ~TIOCM_RTS
;
723 if (clear
& TIOCM_DTR
)
724 control_state
&= ~TIOCM_DTR
;
726 priv
->control_state
= control_state
;
727 spin_unlock_irqrestore(&priv
->lock
, flags
);
728 return mct_u232_set_modem_ctrl(port
, control_state
);
731 static void mct_u232_throttle(struct tty_struct
*tty
)
733 struct usb_serial_port
*port
= tty
->driver_data
;
734 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
735 unsigned int control_state
;
737 spin_lock_irq(&priv
->lock
);
738 priv
->rx_flags
|= THROTTLED
;
739 if (C_CRTSCTS(tty
)) {
740 priv
->control_state
&= ~TIOCM_RTS
;
741 control_state
= priv
->control_state
;
742 spin_unlock_irq(&priv
->lock
);
743 mct_u232_set_modem_ctrl(port
, control_state
);
745 spin_unlock_irq(&priv
->lock
);
749 static void mct_u232_unthrottle(struct tty_struct
*tty
)
751 struct usb_serial_port
*port
= tty
->driver_data
;
752 struct mct_u232_private
*priv
= usb_get_serial_port_data(port
);
753 unsigned int control_state
;
755 spin_lock_irq(&priv
->lock
);
756 if ((priv
->rx_flags
& THROTTLED
) && C_CRTSCTS(tty
)) {
757 priv
->rx_flags
&= ~THROTTLED
;
758 priv
->control_state
|= TIOCM_RTS
;
759 control_state
= priv
->control_state
;
760 spin_unlock_irq(&priv
->lock
);
761 mct_u232_set_modem_ctrl(port
, control_state
);
763 spin_unlock_irq(&priv
->lock
);
767 module_usb_serial_driver(serial_drivers
, id_table
);
769 MODULE_AUTHOR(DRIVER_AUTHOR
);
770 MODULE_DESCRIPTION(DRIVER_DESC
);
771 MODULE_LICENSE("GPL");