Merge branch 'master'
[linux-2.6] / drivers / serial / serial_core.c
1 /*
2  *  linux/drivers/char/core.c
3  *
4  *  Driver core for serial ports
5  *
6  *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
7  *
8  *  Copyright 1999 ARM Limited
9  *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
24  */
25 #include <linux/config.h>
26 #include <linux/module.h>
27 #include <linux/tty.h>
28 #include <linux/slab.h>
29 #include <linux/init.h>
30 #include <linux/console.h>
31 #include <linux/serial_core.h>
32 #include <linux/smp_lock.h>
33 #include <linux/device.h>
34 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
35 #include <linux/delay.h>
36
37 #include <asm/irq.h>
38 #include <asm/uaccess.h>
39
40 #undef  DEBUG
41 #ifdef DEBUG
42 #define DPRINTK(x...)   printk(x)
43 #else
44 #define DPRINTK(x...)   do { } while (0)
45 #endif
46
47 /*
48  * This is used to lock changes in serial line configuration.
49  */
50 static DECLARE_MUTEX(port_sem);
51
52 #define HIGH_BITS_OFFSET        ((sizeof(long)-sizeof(int))*8)
53
54 #define uart_users(state)       ((state)->count + ((state)->info ? (state)->info->blocked_open : 0))
55
56 #ifdef CONFIG_SERIAL_CORE_CONSOLE
57 #define uart_console(port)      ((port)->cons && (port)->cons->index == (port)->line)
58 #else
59 #define uart_console(port)      (0)
60 #endif
61
62 static void uart_change_speed(struct uart_state *state, struct termios *old_termios);
63 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
64 static void uart_change_pm(struct uart_state *state, int pm_state);
65
66 /*
67  * This routine is used by the interrupt handler to schedule processing in
68  * the software interrupt portion of the driver.
69  */
70 void uart_write_wakeup(struct uart_port *port)
71 {
72         struct uart_info *info = port->info;
73         tasklet_schedule(&info->tlet);
74 }
75
76 static void uart_stop(struct tty_struct *tty)
77 {
78         struct uart_state *state = tty->driver_data;
79         struct uart_port *port = state->port;
80         unsigned long flags;
81
82         spin_lock_irqsave(&port->lock, flags);
83         port->ops->stop_tx(port);
84         spin_unlock_irqrestore(&port->lock, flags);
85 }
86
87 static void __uart_start(struct tty_struct *tty)
88 {
89         struct uart_state *state = tty->driver_data;
90         struct uart_port *port = state->port;
91
92         if (!uart_circ_empty(&state->info->xmit) && state->info->xmit.buf &&
93             !tty->stopped && !tty->hw_stopped)
94                 port->ops->start_tx(port);
95 }
96
97 static void uart_start(struct tty_struct *tty)
98 {
99         struct uart_state *state = tty->driver_data;
100         struct uart_port *port = state->port;
101         unsigned long flags;
102
103         spin_lock_irqsave(&port->lock, flags);
104         __uart_start(tty);
105         spin_unlock_irqrestore(&port->lock, flags);
106 }
107
108 static void uart_tasklet_action(unsigned long data)
109 {
110         struct uart_state *state = (struct uart_state *)data;
111         tty_wakeup(state->info->tty);
112 }
113
114 static inline void
115 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
116 {
117         unsigned long flags;
118         unsigned int old;
119
120         spin_lock_irqsave(&port->lock, flags);
121         old = port->mctrl;
122         port->mctrl = (old & ~clear) | set;
123         if (old != port->mctrl)
124                 port->ops->set_mctrl(port, port->mctrl);
125         spin_unlock_irqrestore(&port->lock, flags);
126 }
127
128 #define uart_set_mctrl(port,set)        uart_update_mctrl(port,set,0)
129 #define uart_clear_mctrl(port,clear)    uart_update_mctrl(port,0,clear)
130
131 /*
132  * Startup the port.  This will be called once per open.  All calls
133  * will be serialised by the per-port semaphore.
134  */
135 static int uart_startup(struct uart_state *state, int init_hw)
136 {
137         struct uart_info *info = state->info;
138         struct uart_port *port = state->port;
139         unsigned long page;
140         int retval = 0;
141
142         if (info->flags & UIF_INITIALIZED)
143                 return 0;
144
145         /*
146          * Set the TTY IO error marker - we will only clear this
147          * once we have successfully opened the port.  Also set
148          * up the tty->alt_speed kludge
149          */
150         set_bit(TTY_IO_ERROR, &info->tty->flags);
151
152         if (port->type == PORT_UNKNOWN)
153                 return 0;
154
155         /*
156          * Initialise and allocate the transmit and temporary
157          * buffer.
158          */
159         if (!info->xmit.buf) {
160                 page = get_zeroed_page(GFP_KERNEL);
161                 if (!page)
162                         return -ENOMEM;
163
164                 info->xmit.buf = (unsigned char *) page;
165                 uart_circ_clear(&info->xmit);
166         }
167
168         retval = port->ops->startup(port);
169         if (retval == 0) {
170                 if (init_hw) {
171                         /*
172                          * Initialise the hardware port settings.
173                          */
174                         uart_change_speed(state, NULL);
175
176                         /*
177                          * Setup the RTS and DTR signals once the
178                          * port is open and ready to respond.
179                          */
180                         if (info->tty->termios->c_cflag & CBAUD)
181                                 uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
182                 }
183
184                 if (info->flags & UIF_CTS_FLOW) {
185                         spin_lock_irq(&port->lock);
186                         if (!(port->ops->get_mctrl(port) & TIOCM_CTS))
187                                 info->tty->hw_stopped = 1;
188                         spin_unlock_irq(&port->lock);
189                 }
190
191                 info->flags |= UIF_INITIALIZED;
192
193                 clear_bit(TTY_IO_ERROR, &info->tty->flags);
194         }
195
196         if (retval && capable(CAP_SYS_ADMIN))
197                 retval = 0;
198
199         return retval;
200 }
201
202 /*
203  * This routine will shutdown a serial port; interrupts are disabled, and
204  * DTR is dropped if the hangup on close termio flag is on.  Calls to
205  * uart_shutdown are serialised by the per-port semaphore.
206  */
207 static void uart_shutdown(struct uart_state *state)
208 {
209         struct uart_info *info = state->info;
210         struct uart_port *port = state->port;
211
212         if (!(info->flags & UIF_INITIALIZED))
213                 return;
214
215         /*
216          * Turn off DTR and RTS early.
217          */
218         if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
219                 uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
220
221         /*
222          * clear delta_msr_wait queue to avoid mem leaks: we may free
223          * the irq here so the queue might never be woken up.  Note
224          * that we won't end up waiting on delta_msr_wait again since
225          * any outstanding file descriptors should be pointing at
226          * hung_up_tty_fops now.
227          */
228         wake_up_interruptible(&info->delta_msr_wait);
229
230         /*
231          * Free the IRQ and disable the port.
232          */
233         port->ops->shutdown(port);
234
235         /*
236          * Ensure that the IRQ handler isn't running on another CPU.
237          */
238         synchronize_irq(port->irq);
239
240         /*
241          * Free the transmit buffer page.
242          */
243         if (info->xmit.buf) {
244                 free_page((unsigned long)info->xmit.buf);
245                 info->xmit.buf = NULL;
246         }
247
248         /*
249          * kill off our tasklet
250          */
251         tasklet_kill(&info->tlet);
252         if (info->tty)
253                 set_bit(TTY_IO_ERROR, &info->tty->flags);
254
255         info->flags &= ~UIF_INITIALIZED;
256 }
257
258 /**
259  *      uart_update_timeout - update per-port FIFO timeout.
260  *      @port:  uart_port structure describing the port
261  *      @cflag: termios cflag value
262  *      @baud:  speed of the port
263  *
264  *      Set the port FIFO timeout value.  The @cflag value should
265  *      reflect the actual hardware settings.
266  */
267 void
268 uart_update_timeout(struct uart_port *port, unsigned int cflag,
269                     unsigned int baud)
270 {
271         unsigned int bits;
272
273         /* byte size and parity */
274         switch (cflag & CSIZE) {
275         case CS5:
276                 bits = 7;
277                 break;
278         case CS6:
279                 bits = 8;
280                 break;
281         case CS7:
282                 bits = 9;
283                 break;
284         default:
285                 bits = 10;
286                 break; // CS8
287         }
288
289         if (cflag & CSTOPB)
290                 bits++;
291         if (cflag & PARENB)
292                 bits++;
293
294         /*
295          * The total number of bits to be transmitted in the fifo.
296          */
297         bits = bits * port->fifosize;
298
299         /*
300          * Figure the timeout to send the above number of bits.
301          * Add .02 seconds of slop
302          */
303         port->timeout = (HZ * bits) / baud + HZ/50;
304 }
305
306 EXPORT_SYMBOL(uart_update_timeout);
307
308 /**
309  *      uart_get_baud_rate - return baud rate for a particular port
310  *      @port: uart_port structure describing the port in question.
311  *      @termios: desired termios settings.
312  *      @old: old termios (or NULL)
313  *      @min: minimum acceptable baud rate
314  *      @max: maximum acceptable baud rate
315  *
316  *      Decode the termios structure into a numeric baud rate,
317  *      taking account of the magic 38400 baud rate (with spd_*
318  *      flags), and mapping the %B0 rate to 9600 baud.
319  *
320  *      If the new baud rate is invalid, try the old termios setting.
321  *      If it's still invalid, we try 9600 baud.
322  *
323  *      Update the @termios structure to reflect the baud rate
324  *      we're actually going to be using.
325  */
326 unsigned int
327 uart_get_baud_rate(struct uart_port *port, struct termios *termios,
328                    struct termios *old, unsigned int min, unsigned int max)
329 {
330         unsigned int try, baud, altbaud = 38400;
331         unsigned int flags = port->flags & UPF_SPD_MASK;
332
333         if (flags == UPF_SPD_HI)
334                 altbaud = 57600;
335         if (flags == UPF_SPD_VHI)
336                 altbaud = 115200;
337         if (flags == UPF_SPD_SHI)
338                 altbaud = 230400;
339         if (flags == UPF_SPD_WARP)
340                 altbaud = 460800;
341
342         for (try = 0; try < 2; try++) {
343                 baud = tty_termios_baud_rate(termios);
344
345                 /*
346                  * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
347                  * Die! Die! Die!
348                  */
349                 if (baud == 38400)
350                         baud = altbaud;
351
352                 /*
353                  * Special case: B0 rate.
354                  */
355                 if (baud == 0)
356                         baud = 9600;
357
358                 if (baud >= min && baud <= max)
359                         return baud;
360
361                 /*
362                  * Oops, the quotient was zero.  Try again with
363                  * the old baud rate if possible.
364                  */
365                 termios->c_cflag &= ~CBAUD;
366                 if (old) {
367                         termios->c_cflag |= old->c_cflag & CBAUD;
368                         old = NULL;
369                         continue;
370                 }
371
372                 /*
373                  * As a last resort, if the quotient is zero,
374                  * default to 9600 bps
375                  */
376                 termios->c_cflag |= B9600;
377         }
378
379         return 0;
380 }
381
382 EXPORT_SYMBOL(uart_get_baud_rate);
383
384 /**
385  *      uart_get_divisor - return uart clock divisor
386  *      @port: uart_port structure describing the port.
387  *      @baud: desired baud rate
388  *
389  *      Calculate the uart clock divisor for the port.
390  */
391 unsigned int
392 uart_get_divisor(struct uart_port *port, unsigned int baud)
393 {
394         unsigned int quot;
395
396         /*
397          * Old custom speed handling.
398          */
399         if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
400                 quot = port->custom_divisor;
401         else
402                 quot = (port->uartclk + (8 * baud)) / (16 * baud);
403
404         return quot;
405 }
406
407 EXPORT_SYMBOL(uart_get_divisor);
408
409 static void
410 uart_change_speed(struct uart_state *state, struct termios *old_termios)
411 {
412         struct tty_struct *tty = state->info->tty;
413         struct uart_port *port = state->port;
414         struct termios *termios;
415
416         /*
417          * If we have no tty, termios, or the port does not exist,
418          * then we can't set the parameters for this port.
419          */
420         if (!tty || !tty->termios || port->type == PORT_UNKNOWN)
421                 return;
422
423         termios = tty->termios;
424
425         /*
426          * Set flags based on termios cflag
427          */
428         if (termios->c_cflag & CRTSCTS)
429                 state->info->flags |= UIF_CTS_FLOW;
430         else
431                 state->info->flags &= ~UIF_CTS_FLOW;
432
433         if (termios->c_cflag & CLOCAL)
434                 state->info->flags &= ~UIF_CHECK_CD;
435         else
436                 state->info->flags |= UIF_CHECK_CD;
437
438         port->ops->set_termios(port, termios, old_termios);
439 }
440
441 static inline void
442 __uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c)
443 {
444         unsigned long flags;
445
446         if (!circ->buf)
447                 return;
448
449         spin_lock_irqsave(&port->lock, flags);
450         if (uart_circ_chars_free(circ) != 0) {
451                 circ->buf[circ->head] = c;
452                 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
453         }
454         spin_unlock_irqrestore(&port->lock, flags);
455 }
456
457 static void uart_put_char(struct tty_struct *tty, unsigned char ch)
458 {
459         struct uart_state *state = tty->driver_data;
460
461         __uart_put_char(state->port, &state->info->xmit, ch);
462 }
463
464 static void uart_flush_chars(struct tty_struct *tty)
465 {
466         uart_start(tty);
467 }
468
469 static int
470 uart_write(struct tty_struct *tty, const unsigned char * buf, int count)
471 {
472         struct uart_state *state = tty->driver_data;
473         struct uart_port *port = state->port;
474         struct circ_buf *circ = &state->info->xmit;
475         unsigned long flags;
476         int c, ret = 0;
477
478         if (!circ->buf)
479                 return 0;
480
481         spin_lock_irqsave(&port->lock, flags);
482         while (1) {
483                 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
484                 if (count < c)
485                         c = count;
486                 if (c <= 0)
487                         break;
488                 memcpy(circ->buf + circ->head, buf, c);
489                 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
490                 buf += c;
491                 count -= c;
492                 ret += c;
493         }
494         spin_unlock_irqrestore(&port->lock, flags);
495
496         uart_start(tty);
497         return ret;
498 }
499
500 static int uart_write_room(struct tty_struct *tty)
501 {
502         struct uart_state *state = tty->driver_data;
503
504         return uart_circ_chars_free(&state->info->xmit);
505 }
506
507 static int uart_chars_in_buffer(struct tty_struct *tty)
508 {
509         struct uart_state *state = tty->driver_data;
510
511         return uart_circ_chars_pending(&state->info->xmit);
512 }
513
514 static void uart_flush_buffer(struct tty_struct *tty)
515 {
516         struct uart_state *state = tty->driver_data;
517         struct uart_port *port = state->port;
518         unsigned long flags;
519
520         DPRINTK("uart_flush_buffer(%d) called\n", tty->index);
521
522         spin_lock_irqsave(&port->lock, flags);
523         uart_circ_clear(&state->info->xmit);
524         spin_unlock_irqrestore(&port->lock, flags);
525         tty_wakeup(tty);
526 }
527
528 /*
529  * This function is used to send a high-priority XON/XOFF character to
530  * the device
531  */
532 static void uart_send_xchar(struct tty_struct *tty, char ch)
533 {
534         struct uart_state *state = tty->driver_data;
535         struct uart_port *port = state->port;
536         unsigned long flags;
537
538         if (port->ops->send_xchar)
539                 port->ops->send_xchar(port, ch);
540         else {
541                 port->x_char = ch;
542                 if (ch) {
543                         spin_lock_irqsave(&port->lock, flags);
544                         port->ops->start_tx(port);
545                         spin_unlock_irqrestore(&port->lock, flags);
546                 }
547         }
548 }
549
550 static void uart_throttle(struct tty_struct *tty)
551 {
552         struct uart_state *state = tty->driver_data;
553
554         if (I_IXOFF(tty))
555                 uart_send_xchar(tty, STOP_CHAR(tty));
556
557         if (tty->termios->c_cflag & CRTSCTS)
558                 uart_clear_mctrl(state->port, TIOCM_RTS);
559 }
560
561 static void uart_unthrottle(struct tty_struct *tty)
562 {
563         struct uart_state *state = tty->driver_data;
564         struct uart_port *port = state->port;
565
566         if (I_IXOFF(tty)) {
567                 if (port->x_char)
568                         port->x_char = 0;
569                 else
570                         uart_send_xchar(tty, START_CHAR(tty));
571         }
572
573         if (tty->termios->c_cflag & CRTSCTS)
574                 uart_set_mctrl(port, TIOCM_RTS);
575 }
576
577 static int uart_get_info(struct uart_state *state,
578                          struct serial_struct __user *retinfo)
579 {
580         struct uart_port *port = state->port;
581         struct serial_struct tmp;
582
583         memset(&tmp, 0, sizeof(tmp));
584         tmp.type            = port->type;
585         tmp.line            = port->line;
586         tmp.port            = port->iobase;
587         if (HIGH_BITS_OFFSET)
588                 tmp.port_high = (long) port->iobase >> HIGH_BITS_OFFSET;
589         tmp.irq             = port->irq;
590         tmp.flags           = port->flags;
591         tmp.xmit_fifo_size  = port->fifosize;
592         tmp.baud_base       = port->uartclk / 16;
593         tmp.close_delay     = state->close_delay / 10;
594         tmp.closing_wait    = state->closing_wait == USF_CLOSING_WAIT_NONE ?
595                                 ASYNC_CLOSING_WAIT_NONE :
596                                 state->closing_wait / 10;
597         tmp.custom_divisor  = port->custom_divisor;
598         tmp.hub6            = port->hub6;
599         tmp.io_type         = port->iotype;
600         tmp.iomem_reg_shift = port->regshift;
601         tmp.iomem_base      = (void *)port->mapbase;
602
603         if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
604                 return -EFAULT;
605         return 0;
606 }
607
608 static int uart_set_info(struct uart_state *state,
609                          struct serial_struct __user *newinfo)
610 {
611         struct serial_struct new_serial;
612         struct uart_port *port = state->port;
613         unsigned long new_port;
614         unsigned int change_irq, change_port, old_flags, closing_wait;
615         unsigned int old_custom_divisor, close_delay;
616         int retval = 0;
617
618         if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
619                 return -EFAULT;
620
621         new_port = new_serial.port;
622         if (HIGH_BITS_OFFSET)
623                 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
624
625         new_serial.irq = irq_canonicalize(new_serial.irq);
626         close_delay = new_serial.close_delay * 10;
627         closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
628                         USF_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
629
630         /*
631          * This semaphore protects state->count.  It is also
632          * very useful to prevent opens.  Also, take the
633          * port configuration semaphore to make sure that a
634          * module insertion/removal doesn't change anything
635          * under us.
636          */
637         down(&state->sem);
638
639         change_irq  = new_serial.irq != port->irq;
640
641         /*
642          * Since changing the 'type' of the port changes its resource
643          * allocations, we should treat type changes the same as
644          * IO port changes.
645          */
646         change_port = new_port != port->iobase ||
647                       (unsigned long)new_serial.iomem_base != port->mapbase ||
648                       new_serial.hub6 != port->hub6 ||
649                       new_serial.io_type != port->iotype ||
650                       new_serial.iomem_reg_shift != port->regshift ||
651                       new_serial.type != port->type;
652
653         old_flags = port->flags;
654         old_custom_divisor = port->custom_divisor;
655
656         if (!capable(CAP_SYS_ADMIN)) {
657                 retval = -EPERM;
658                 if (change_irq || change_port ||
659                     (new_serial.baud_base != port->uartclk / 16) ||
660                     (close_delay != state->close_delay) ||
661                     (closing_wait != state->closing_wait) ||
662                     (new_serial.xmit_fifo_size != port->fifosize) ||
663                     (((new_serial.flags ^ old_flags) & ~UPF_USR_MASK) != 0))
664                         goto exit;
665                 port->flags = ((port->flags & ~UPF_USR_MASK) |
666                                (new_serial.flags & UPF_USR_MASK));
667                 port->custom_divisor = new_serial.custom_divisor;
668                 goto check_and_exit;
669         }
670
671         /*
672          * Ask the low level driver to verify the settings.
673          */
674         if (port->ops->verify_port)
675                 retval = port->ops->verify_port(port, &new_serial);
676
677         if ((new_serial.irq >= NR_IRQS) || (new_serial.irq < 0) ||
678             (new_serial.baud_base < 9600))
679                 retval = -EINVAL;
680
681         if (retval)
682                 goto exit;
683
684         if (change_port || change_irq) {
685                 retval = -EBUSY;
686
687                 /*
688                  * Make sure that we are the sole user of this port.
689                  */
690                 if (uart_users(state) > 1)
691                         goto exit;
692
693                 /*
694                  * We need to shutdown the serial port at the old
695                  * port/type/irq combination.
696                  */
697                 uart_shutdown(state);
698         }
699
700         if (change_port) {
701                 unsigned long old_iobase, old_mapbase;
702                 unsigned int old_type, old_iotype, old_hub6, old_shift;
703
704                 old_iobase = port->iobase;
705                 old_mapbase = port->mapbase;
706                 old_type = port->type;
707                 old_hub6 = port->hub6;
708                 old_iotype = port->iotype;
709                 old_shift = port->regshift;
710
711                 /*
712                  * Free and release old regions
713                  */
714                 if (old_type != PORT_UNKNOWN)
715                         port->ops->release_port(port);
716
717                 port->iobase = new_port;
718                 port->type = new_serial.type;
719                 port->hub6 = new_serial.hub6;
720                 port->iotype = new_serial.io_type;
721                 port->regshift = new_serial.iomem_reg_shift;
722                 port->mapbase = (unsigned long)new_serial.iomem_base;
723
724                 /*
725                  * Claim and map the new regions
726                  */
727                 if (port->type != PORT_UNKNOWN) {
728                         retval = port->ops->request_port(port);
729                 } else {
730                         /* Always success - Jean II */
731                         retval = 0;
732                 }
733
734                 /*
735                  * If we fail to request resources for the
736                  * new port, try to restore the old settings.
737                  */
738                 if (retval && old_type != PORT_UNKNOWN) {
739                         port->iobase = old_iobase;
740                         port->type = old_type;
741                         port->hub6 = old_hub6;
742                         port->iotype = old_iotype;
743                         port->regshift = old_shift;
744                         port->mapbase = old_mapbase;
745                         retval = port->ops->request_port(port);
746                         /*
747                          * If we failed to restore the old settings,
748                          * we fail like this.
749                          */
750                         if (retval)
751                                 port->type = PORT_UNKNOWN;
752
753                         /*
754                          * We failed anyway.
755                          */
756                         retval = -EBUSY;
757                 }
758         }
759
760         port->irq              = new_serial.irq;
761         port->uartclk          = new_serial.baud_base * 16;
762         port->flags            = (port->flags & ~UPF_CHANGE_MASK) |
763                                  (new_serial.flags & UPF_CHANGE_MASK);
764         port->custom_divisor   = new_serial.custom_divisor;
765         state->close_delay     = close_delay;
766         state->closing_wait    = closing_wait;
767         port->fifosize         = new_serial.xmit_fifo_size;
768         if (state->info->tty)
769                 state->info->tty->low_latency =
770                         (port->flags & UPF_LOW_LATENCY) ? 1 : 0;
771
772  check_and_exit:
773         retval = 0;
774         if (port->type == PORT_UNKNOWN)
775                 goto exit;
776         if (state->info->flags & UIF_INITIALIZED) {
777                 if (((old_flags ^ port->flags) & UPF_SPD_MASK) ||
778                     old_custom_divisor != port->custom_divisor) {
779                         /*
780                          * If they're setting up a custom divisor or speed,
781                          * instead of clearing it, then bitch about it. No
782                          * need to rate-limit; it's CAP_SYS_ADMIN only.
783                          */
784                         if (port->flags & UPF_SPD_MASK) {
785                                 char buf[64];
786                                 printk(KERN_NOTICE
787                                        "%s sets custom speed on %s. This "
788                                        "is deprecated.\n", current->comm,
789                                        tty_name(state->info->tty, buf));
790                         }
791                         uart_change_speed(state, NULL);
792                 }
793         } else
794                 retval = uart_startup(state, 1);
795  exit:
796         up(&state->sem);
797         return retval;
798 }
799
800
801 /*
802  * uart_get_lsr_info - get line status register info.
803  * Note: uart_ioctl protects us against hangups.
804  */
805 static int uart_get_lsr_info(struct uart_state *state,
806                              unsigned int __user *value)
807 {
808         struct uart_port *port = state->port;
809         unsigned int result;
810
811         result = port->ops->tx_empty(port);
812
813         /*
814          * If we're about to load something into the transmit
815          * register, we'll pretend the transmitter isn't empty to
816          * avoid a race condition (depending on when the transmit
817          * interrupt happens).
818          */
819         if (port->x_char ||
820             ((uart_circ_chars_pending(&state->info->xmit) > 0) &&
821              !state->info->tty->stopped && !state->info->tty->hw_stopped))
822                 result &= ~TIOCSER_TEMT;
823         
824         return put_user(result, value);
825 }
826
827 static int uart_tiocmget(struct tty_struct *tty, struct file *file)
828 {
829         struct uart_state *state = tty->driver_data;
830         struct uart_port *port = state->port;
831         int result = -EIO;
832
833         down(&state->sem);
834         if ((!file || !tty_hung_up_p(file)) &&
835             !(tty->flags & (1 << TTY_IO_ERROR))) {
836                 result = port->mctrl;
837
838                 spin_lock_irq(&port->lock);
839                 result |= port->ops->get_mctrl(port);
840                 spin_unlock_irq(&port->lock);
841         }
842         up(&state->sem);
843
844         return result;
845 }
846
847 static int
848 uart_tiocmset(struct tty_struct *tty, struct file *file,
849               unsigned int set, unsigned int clear)
850 {
851         struct uart_state *state = tty->driver_data;
852         struct uart_port *port = state->port;
853         int ret = -EIO;
854
855         down(&state->sem);
856         if ((!file || !tty_hung_up_p(file)) &&
857             !(tty->flags & (1 << TTY_IO_ERROR))) {
858                 uart_update_mctrl(port, set, clear);
859                 ret = 0;
860         }
861         up(&state->sem);
862         return ret;
863 }
864
865 static void uart_break_ctl(struct tty_struct *tty, int break_state)
866 {
867         struct uart_state *state = tty->driver_data;
868         struct uart_port *port = state->port;
869
870         BUG_ON(!kernel_locked());
871
872         down(&state->sem);
873
874         if (port->type != PORT_UNKNOWN)
875                 port->ops->break_ctl(port, break_state);
876
877         up(&state->sem);
878 }
879
880 static int uart_do_autoconfig(struct uart_state *state)
881 {
882         struct uart_port *port = state->port;
883         int flags, ret;
884
885         if (!capable(CAP_SYS_ADMIN))
886                 return -EPERM;
887
888         /*
889          * Take the per-port semaphore.  This prevents count from
890          * changing, and hence any extra opens of the port while
891          * we're auto-configuring.
892          */
893         if (down_interruptible(&state->sem))
894                 return -ERESTARTSYS;
895
896         ret = -EBUSY;
897         if (uart_users(state) == 1) {
898                 uart_shutdown(state);
899
900                 /*
901                  * If we already have a port type configured,
902                  * we must release its resources.
903                  */
904                 if (port->type != PORT_UNKNOWN)
905                         port->ops->release_port(port);
906
907                 flags = UART_CONFIG_TYPE;
908                 if (port->flags & UPF_AUTO_IRQ)
909                         flags |= UART_CONFIG_IRQ;
910
911                 /*
912                  * This will claim the ports resources if
913                  * a port is found.
914                  */
915                 port->ops->config_port(port, flags);
916
917                 ret = uart_startup(state, 1);
918         }
919         up(&state->sem);
920         return ret;
921 }
922
923 /*
924  * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
925  * - mask passed in arg for lines of interest
926  *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
927  * Caller should use TIOCGICOUNT to see which one it was
928  */
929 static int
930 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
931 {
932         struct uart_port *port = state->port;
933         DECLARE_WAITQUEUE(wait, current);
934         struct uart_icount cprev, cnow;
935         int ret;
936
937         /*
938          * note the counters on entry
939          */
940         spin_lock_irq(&port->lock);
941         memcpy(&cprev, &port->icount, sizeof(struct uart_icount));
942
943         /*
944          * Force modem status interrupts on
945          */
946         port->ops->enable_ms(port);
947         spin_unlock_irq(&port->lock);
948
949         add_wait_queue(&state->info->delta_msr_wait, &wait);
950         for (;;) {
951                 spin_lock_irq(&port->lock);
952                 memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
953                 spin_unlock_irq(&port->lock);
954
955                 set_current_state(TASK_INTERRUPTIBLE);
956
957                 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
958                     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
959                     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
960                     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
961                         ret = 0;
962                         break;
963                 }
964
965                 schedule();
966
967                 /* see if a signal did it */
968                 if (signal_pending(current)) {
969                         ret = -ERESTARTSYS;
970                         break;
971                 }
972
973                 cprev = cnow;
974         }
975
976         current->state = TASK_RUNNING;
977         remove_wait_queue(&state->info->delta_msr_wait, &wait);
978
979         return ret;
980 }
981
982 /*
983  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
984  * Return: write counters to the user passed counter struct
985  * NB: both 1->0 and 0->1 transitions are counted except for
986  *     RI where only 0->1 is counted.
987  */
988 static int uart_get_count(struct uart_state *state,
989                           struct serial_icounter_struct __user *icnt)
990 {
991         struct serial_icounter_struct icount;
992         struct uart_icount cnow;
993         struct uart_port *port = state->port;
994
995         spin_lock_irq(&port->lock);
996         memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
997         spin_unlock_irq(&port->lock);
998
999         icount.cts         = cnow.cts;
1000         icount.dsr         = cnow.dsr;
1001         icount.rng         = cnow.rng;
1002         icount.dcd         = cnow.dcd;
1003         icount.rx          = cnow.rx;
1004         icount.tx          = cnow.tx;
1005         icount.frame       = cnow.frame;
1006         icount.overrun     = cnow.overrun;
1007         icount.parity      = cnow.parity;
1008         icount.brk         = cnow.brk;
1009         icount.buf_overrun = cnow.buf_overrun;
1010
1011         return copy_to_user(icnt, &icount, sizeof(icount)) ? -EFAULT : 0;
1012 }
1013
1014 /*
1015  * Called via sys_ioctl under the BKL.  We can use spin_lock_irq() here.
1016  */
1017 static int
1018 uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
1019            unsigned long arg)
1020 {
1021         struct uart_state *state = tty->driver_data;
1022         void __user *uarg = (void __user *)arg;
1023         int ret = -ENOIOCTLCMD;
1024
1025         BUG_ON(!kernel_locked());
1026
1027         /*
1028          * These ioctls don't rely on the hardware to be present.
1029          */
1030         switch (cmd) {
1031         case TIOCGSERIAL:
1032                 ret = uart_get_info(state, uarg);
1033                 break;
1034
1035         case TIOCSSERIAL:
1036                 ret = uart_set_info(state, uarg);
1037                 break;
1038
1039         case TIOCSERCONFIG:
1040                 ret = uart_do_autoconfig(state);
1041                 break;
1042
1043         case TIOCSERGWILD: /* obsolete */
1044         case TIOCSERSWILD: /* obsolete */
1045                 ret = 0;
1046                 break;
1047         }
1048
1049         if (ret != -ENOIOCTLCMD)
1050                 goto out;
1051
1052         if (tty->flags & (1 << TTY_IO_ERROR)) {
1053                 ret = -EIO;
1054                 goto out;
1055         }
1056
1057         /*
1058          * The following should only be used when hardware is present.
1059          */
1060         switch (cmd) {
1061         case TIOCMIWAIT:
1062                 ret = uart_wait_modem_status(state, arg);
1063                 break;
1064
1065         case TIOCGICOUNT:
1066                 ret = uart_get_count(state, uarg);
1067                 break;
1068         }
1069
1070         if (ret != -ENOIOCTLCMD)
1071                 goto out;
1072
1073         down(&state->sem);
1074
1075         if (tty_hung_up_p(filp)) {
1076                 ret = -EIO;
1077                 goto out_up;
1078         }
1079
1080         /*
1081          * All these rely on hardware being present and need to be
1082          * protected against the tty being hung up.
1083          */
1084         switch (cmd) {
1085         case TIOCSERGETLSR: /* Get line status register */
1086                 ret = uart_get_lsr_info(state, uarg);
1087                 break;
1088
1089         default: {
1090                 struct uart_port *port = state->port;
1091                 if (port->ops->ioctl)
1092                         ret = port->ops->ioctl(port, cmd, arg);
1093                 break;
1094         }
1095         }
1096  out_up:
1097         up(&state->sem);
1098  out:
1099         return ret;
1100 }
1101
1102 static void uart_set_termios(struct tty_struct *tty, struct termios *old_termios)
1103 {
1104         struct uart_state *state = tty->driver_data;
1105         unsigned long flags;
1106         unsigned int cflag = tty->termios->c_cflag;
1107
1108         BUG_ON(!kernel_locked());
1109
1110         /*
1111          * These are the bits that are used to setup various
1112          * flags in the low level driver.
1113          */
1114 #define RELEVANT_IFLAG(iflag)   ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1115
1116         if ((cflag ^ old_termios->c_cflag) == 0 &&
1117             RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0)
1118                 return;
1119
1120         uart_change_speed(state, old_termios);
1121
1122         /* Handle transition to B0 status */
1123         if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1124                 uart_clear_mctrl(state->port, TIOCM_RTS | TIOCM_DTR);
1125
1126         /* Handle transition away from B0 status */
1127         if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1128                 unsigned int mask = TIOCM_DTR;
1129                 if (!(cflag & CRTSCTS) ||
1130                     !test_bit(TTY_THROTTLED, &tty->flags))
1131                         mask |= TIOCM_RTS;
1132                 uart_set_mctrl(state->port, mask);
1133         }
1134
1135         /* Handle turning off CRTSCTS */
1136         if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1137                 spin_lock_irqsave(&state->port->lock, flags);
1138                 tty->hw_stopped = 0;
1139                 __uart_start(tty);
1140                 spin_unlock_irqrestore(&state->port->lock, flags);
1141         }
1142
1143         /* Handle turning on CRTSCTS */
1144         if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1145                 spin_lock_irqsave(&state->port->lock, flags);
1146                 if (!(state->port->ops->get_mctrl(state->port) & TIOCM_CTS)) {
1147                         tty->hw_stopped = 1;
1148                         state->port->ops->stop_tx(state->port);
1149                 }
1150                 spin_unlock_irqrestore(&state->port->lock, flags);
1151         }
1152
1153 #if 0
1154         /*
1155          * No need to wake up processes in open wait, since they
1156          * sample the CLOCAL flag once, and don't recheck it.
1157          * XXX  It's not clear whether the current behavior is correct
1158          * or not.  Hence, this may change.....
1159          */
1160         if (!(old_termios->c_cflag & CLOCAL) &&
1161             (tty->termios->c_cflag & CLOCAL))
1162                 wake_up_interruptible(&state->info->open_wait);
1163 #endif
1164 }
1165
1166 /*
1167  * In 2.4.5, calls to this will be serialized via the BKL in
1168  *  linux/drivers/char/tty_io.c:tty_release()
1169  *  linux/drivers/char/tty_io.c:do_tty_handup()
1170  */
1171 static void uart_close(struct tty_struct *tty, struct file *filp)
1172 {
1173         struct uart_state *state = tty->driver_data;
1174         struct uart_port *port;
1175         
1176         BUG_ON(!kernel_locked());
1177
1178         if (!state || !state->port)
1179                 return;
1180
1181         port = state->port;
1182
1183         DPRINTK("uart_close(%d) called\n", port->line);
1184
1185         down(&state->sem);
1186
1187         if (tty_hung_up_p(filp))
1188                 goto done;
1189
1190         if ((tty->count == 1) && (state->count != 1)) {
1191                 /*
1192                  * Uh, oh.  tty->count is 1, which means that the tty
1193                  * structure will be freed.  state->count should always
1194                  * be one in these conditions.  If it's greater than
1195                  * one, we've got real problems, since it means the
1196                  * serial port won't be shutdown.
1197                  */
1198                 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1199                        "state->count is %d\n", state->count);
1200                 state->count = 1;
1201         }
1202         if (--state->count < 0) {
1203                 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1204                        tty->name, state->count);
1205                 state->count = 0;
1206         }
1207         if (state->count)
1208                 goto done;
1209
1210         /*
1211          * Now we wait for the transmit buffer to clear; and we notify
1212          * the line discipline to only process XON/XOFF characters by
1213          * setting tty->closing.
1214          */
1215         tty->closing = 1;
1216
1217         if (state->closing_wait != USF_CLOSING_WAIT_NONE)
1218                 tty_wait_until_sent(tty, msecs_to_jiffies(state->closing_wait));
1219
1220         /*
1221          * At this point, we stop accepting input.  To do this, we
1222          * disable the receive line status interrupts.
1223          */
1224         if (state->info->flags & UIF_INITIALIZED) {
1225                 unsigned long flags;
1226                 spin_lock_irqsave(&port->lock, flags);
1227                 port->ops->stop_rx(port);
1228                 spin_unlock_irqrestore(&port->lock, flags);
1229                 /*
1230                  * Before we drop DTR, make sure the UART transmitter
1231                  * has completely drained; this is especially
1232                  * important if there is a transmit FIFO!
1233                  */
1234                 uart_wait_until_sent(tty, port->timeout);
1235         }
1236
1237         uart_shutdown(state);
1238         uart_flush_buffer(tty);
1239
1240         tty_ldisc_flush(tty);   
1241         
1242         tty->closing = 0;
1243         state->info->tty = NULL;
1244
1245         if (state->info->blocked_open) {
1246                 if (state->close_delay)
1247                         msleep_interruptible(state->close_delay);
1248         } else if (!uart_console(port)) {
1249                 uart_change_pm(state, 3);
1250         }
1251
1252         /*
1253          * Wake up anyone trying to open this port.
1254          */
1255         state->info->flags &= ~UIF_NORMAL_ACTIVE;
1256         wake_up_interruptible(&state->info->open_wait);
1257
1258  done:
1259         up(&state->sem);
1260 }
1261
1262 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1263 {
1264         struct uart_state *state = tty->driver_data;
1265         struct uart_port *port = state->port;
1266         unsigned long char_time, expire;
1267
1268         BUG_ON(!kernel_locked());
1269
1270         if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1271                 return;
1272
1273         /*
1274          * Set the check interval to be 1/5 of the estimated time to
1275          * send a single character, and make it at least 1.  The check
1276          * interval should also be less than the timeout.
1277          *
1278          * Note: we have to use pretty tight timings here to satisfy
1279          * the NIST-PCTS.
1280          */
1281         char_time = (port->timeout - HZ/50) / port->fifosize;
1282         char_time = char_time / 5;
1283         if (char_time == 0)
1284                 char_time = 1;
1285         if (timeout && timeout < char_time)
1286                 char_time = timeout;
1287
1288         /*
1289          * If the transmitter hasn't cleared in twice the approximate
1290          * amount of time to send the entire FIFO, it probably won't
1291          * ever clear.  This assumes the UART isn't doing flow
1292          * control, which is currently the case.  Hence, if it ever
1293          * takes longer than port->timeout, this is probably due to a
1294          * UART bug of some kind.  So, we clamp the timeout parameter at
1295          * 2*port->timeout.
1296          */
1297         if (timeout == 0 || timeout > 2 * port->timeout)
1298                 timeout = 2 * port->timeout;
1299
1300         expire = jiffies + timeout;
1301
1302         DPRINTK("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1303                 port->line, jiffies, expire);
1304
1305         /*
1306          * Check whether the transmitter is empty every 'char_time'.
1307          * 'timeout' / 'expire' give us the maximum amount of time
1308          * we wait.
1309          */
1310         while (!port->ops->tx_empty(port)) {
1311                 msleep_interruptible(jiffies_to_msecs(char_time));
1312                 if (signal_pending(current))
1313                         break;
1314                 if (time_after(jiffies, expire))
1315                         break;
1316         }
1317         set_current_state(TASK_RUNNING); /* might not be needed */
1318 }
1319
1320 /*
1321  * This is called with the BKL held in
1322  *  linux/drivers/char/tty_io.c:do_tty_hangup()
1323  * We're called from the eventd thread, so we can sleep for
1324  * a _short_ time only.
1325  */
1326 static void uart_hangup(struct tty_struct *tty)
1327 {
1328         struct uart_state *state = tty->driver_data;
1329
1330         BUG_ON(!kernel_locked());
1331         DPRINTK("uart_hangup(%d)\n", state->port->line);
1332
1333         down(&state->sem);
1334         if (state->info && state->info->flags & UIF_NORMAL_ACTIVE) {
1335                 uart_flush_buffer(tty);
1336                 uart_shutdown(state);
1337                 state->count = 0;
1338                 state->info->flags &= ~UIF_NORMAL_ACTIVE;
1339                 state->info->tty = NULL;
1340                 wake_up_interruptible(&state->info->open_wait);
1341                 wake_up_interruptible(&state->info->delta_msr_wait);
1342         }
1343         up(&state->sem);
1344 }
1345
1346 /*
1347  * Copy across the serial console cflag setting into the termios settings
1348  * for the initial open of the port.  This allows continuity between the
1349  * kernel settings, and the settings init adopts when it opens the port
1350  * for the first time.
1351  */
1352 static void uart_update_termios(struct uart_state *state)
1353 {
1354         struct tty_struct *tty = state->info->tty;
1355         struct uart_port *port = state->port;
1356
1357         if (uart_console(port) && port->cons->cflag) {
1358                 tty->termios->c_cflag = port->cons->cflag;
1359                 port->cons->cflag = 0;
1360         }
1361
1362         /*
1363          * If the device failed to grab its irq resources,
1364          * or some other error occurred, don't try to talk
1365          * to the port hardware.
1366          */
1367         if (!(tty->flags & (1 << TTY_IO_ERROR))) {
1368                 /*
1369                  * Make termios settings take effect.
1370                  */
1371                 uart_change_speed(state, NULL);
1372
1373                 /*
1374                  * And finally enable the RTS and DTR signals.
1375                  */
1376                 if (tty->termios->c_cflag & CBAUD)
1377                         uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
1378         }
1379 }
1380
1381 /*
1382  * Block the open until the port is ready.  We must be called with
1383  * the per-port semaphore held.
1384  */
1385 static int
1386 uart_block_til_ready(struct file *filp, struct uart_state *state)
1387 {
1388         DECLARE_WAITQUEUE(wait, current);
1389         struct uart_info *info = state->info;
1390         struct uart_port *port = state->port;
1391         unsigned int mctrl;
1392
1393         info->blocked_open++;
1394         state->count--;
1395
1396         add_wait_queue(&info->open_wait, &wait);
1397         while (1) {
1398                 set_current_state(TASK_INTERRUPTIBLE);
1399
1400                 /*
1401                  * If we have been hung up, tell userspace/restart open.
1402                  */
1403                 if (tty_hung_up_p(filp) || info->tty == NULL)
1404                         break;
1405
1406                 /*
1407                  * If the port has been closed, tell userspace/restart open.
1408                  */
1409                 if (!(info->flags & UIF_INITIALIZED))
1410                         break;
1411
1412                 /*
1413                  * If non-blocking mode is set, or CLOCAL mode is set,
1414                  * we don't want to wait for the modem status lines to
1415                  * indicate that the port is ready.
1416                  *
1417                  * Also, if the port is not enabled/configured, we want
1418                  * to allow the open to succeed here.  Note that we will
1419                  * have set TTY_IO_ERROR for a non-existant port.
1420                  */
1421                 if ((filp->f_flags & O_NONBLOCK) ||
1422                     (info->tty->termios->c_cflag & CLOCAL) ||
1423                     (info->tty->flags & (1 << TTY_IO_ERROR))) {
1424                         break;
1425                 }
1426
1427                 /*
1428                  * Set DTR to allow modem to know we're waiting.  Do
1429                  * not set RTS here - we want to make sure we catch
1430                  * the data from the modem.
1431                  */
1432                 if (info->tty->termios->c_cflag & CBAUD)
1433                         uart_set_mctrl(port, TIOCM_DTR);
1434
1435                 /*
1436                  * and wait for the carrier to indicate that the
1437                  * modem is ready for us.
1438                  */
1439                 spin_lock_irq(&port->lock);
1440                 mctrl = port->ops->get_mctrl(port);
1441                 spin_unlock_irq(&port->lock);
1442                 if (mctrl & TIOCM_CAR)
1443                         break;
1444
1445                 up(&state->sem);
1446                 schedule();
1447                 down(&state->sem);
1448
1449                 if (signal_pending(current))
1450                         break;
1451         }
1452         set_current_state(TASK_RUNNING);
1453         remove_wait_queue(&info->open_wait, &wait);
1454
1455         state->count++;
1456         info->blocked_open--;
1457
1458         if (signal_pending(current))
1459                 return -ERESTARTSYS;
1460
1461         if (!info->tty || tty_hung_up_p(filp))
1462                 return -EAGAIN;
1463
1464         return 0;
1465 }
1466
1467 static struct uart_state *uart_get(struct uart_driver *drv, int line)
1468 {
1469         struct uart_state *state;
1470
1471         down(&port_sem);
1472         state = drv->state + line;
1473         if (down_interruptible(&state->sem)) {
1474                 state = ERR_PTR(-ERESTARTSYS);
1475                 goto out;
1476         }
1477
1478         state->count++;
1479         if (!state->port) {
1480                 state->count--;
1481                 up(&state->sem);
1482                 state = ERR_PTR(-ENXIO);
1483                 goto out;
1484         }
1485
1486         if (!state->info) {
1487                 state->info = kmalloc(sizeof(struct uart_info), GFP_KERNEL);
1488                 if (state->info) {
1489                         memset(state->info, 0, sizeof(struct uart_info));
1490                         init_waitqueue_head(&state->info->open_wait);
1491                         init_waitqueue_head(&state->info->delta_msr_wait);
1492
1493                         /*
1494                          * Link the info into the other structures.
1495                          */
1496                         state->port->info = state->info;
1497
1498                         tasklet_init(&state->info->tlet, uart_tasklet_action,
1499                                      (unsigned long)state);
1500                 } else {
1501                         state->count--;
1502                         up(&state->sem);
1503                         state = ERR_PTR(-ENOMEM);
1504                 }
1505         }
1506
1507  out:
1508         up(&port_sem);
1509         return state;
1510 }
1511
1512 /*
1513  * In 2.4.5, calls to uart_open are serialised by the BKL in
1514  *   linux/fs/devices.c:chrdev_open()
1515  * Note that if this fails, then uart_close() _will_ be called.
1516  *
1517  * In time, we want to scrap the "opening nonpresent ports"
1518  * behaviour and implement an alternative way for setserial
1519  * to set base addresses/ports/types.  This will allow us to
1520  * get rid of a certain amount of extra tests.
1521  */
1522 static int uart_open(struct tty_struct *tty, struct file *filp)
1523 {
1524         struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1525         struct uart_state *state;
1526         int retval, line = tty->index;
1527
1528         BUG_ON(!kernel_locked());
1529         DPRINTK("uart_open(%d) called\n", line);
1530
1531         /*
1532          * tty->driver->num won't change, so we won't fail here with
1533          * tty->driver_data set to something non-NULL (and therefore
1534          * we won't get caught by uart_close()).
1535          */
1536         retval = -ENODEV;
1537         if (line >= tty->driver->num)
1538                 goto fail;
1539
1540         /*
1541          * We take the semaphore inside uart_get to guarantee that we won't
1542          * be re-entered while allocating the info structure, or while we
1543          * request any IRQs that the driver may need.  This also has the nice
1544          * side-effect that it delays the action of uart_hangup, so we can
1545          * guarantee that info->tty will always contain something reasonable.
1546          */
1547         state = uart_get(drv, line);
1548         if (IS_ERR(state)) {
1549                 retval = PTR_ERR(state);
1550                 goto fail;
1551         }
1552
1553         /*
1554          * Once we set tty->driver_data here, we are guaranteed that
1555          * uart_close() will decrement the driver module use count.
1556          * Any failures from here onwards should not touch the count.
1557          */
1558         tty->driver_data = state;
1559         tty->low_latency = (state->port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1560         tty->alt_speed = 0;
1561         state->info->tty = tty;
1562
1563         /*
1564          * If the port is in the middle of closing, bail out now.
1565          */
1566         if (tty_hung_up_p(filp)) {
1567                 retval = -EAGAIN;
1568                 state->count--;
1569                 up(&state->sem);
1570                 goto fail;
1571         }
1572
1573         /*
1574          * Make sure the device is in D0 state.
1575          */
1576         if (state->count == 1)
1577                 uart_change_pm(state, 0);
1578
1579         /*
1580          * Start up the serial port.
1581          */
1582         retval = uart_startup(state, 0);
1583
1584         /*
1585          * If we succeeded, wait until the port is ready.
1586          */
1587         if (retval == 0)
1588                 retval = uart_block_til_ready(filp, state);
1589         up(&state->sem);
1590
1591         /*
1592          * If this is the first open to succeed, adjust things to suit.
1593          */
1594         if (retval == 0 && !(state->info->flags & UIF_NORMAL_ACTIVE)) {
1595                 state->info->flags |= UIF_NORMAL_ACTIVE;
1596
1597                 uart_update_termios(state);
1598         }
1599
1600  fail:
1601         return retval;
1602 }
1603
1604 static const char *uart_type(struct uart_port *port)
1605 {
1606         const char *str = NULL;
1607
1608         if (port->ops->type)
1609                 str = port->ops->type(port);
1610
1611         if (!str)
1612                 str = "unknown";
1613
1614         return str;
1615 }
1616
1617 #ifdef CONFIG_PROC_FS
1618
1619 static int uart_line_info(char *buf, struct uart_driver *drv, int i)
1620 {
1621         struct uart_state *state = drv->state + i;
1622         struct uart_port *port = state->port;
1623         char stat_buf[32];
1624         unsigned int status;
1625         int ret;
1626
1627         if (!port)
1628                 return 0;
1629
1630         ret = sprintf(buf, "%d: uart:%s %s%08lX irq:%d",
1631                         port->line, uart_type(port),
1632                         port->iotype == UPIO_MEM ? "mmio:0x" : "port:",
1633                         port->iotype == UPIO_MEM ? port->mapbase :
1634                                                 (unsigned long) port->iobase,
1635                         port->irq);
1636
1637         if (port->type == PORT_UNKNOWN) {
1638                 strcat(buf, "\n");
1639                 return ret + 1;
1640         }
1641
1642         if(capable(CAP_SYS_ADMIN))
1643         {
1644                 spin_lock_irq(&port->lock);
1645                 status = port->ops->get_mctrl(port);
1646                 spin_unlock_irq(&port->lock);
1647
1648                 ret += sprintf(buf + ret, " tx:%d rx:%d",
1649                                 port->icount.tx, port->icount.rx);
1650                 if (port->icount.frame)
1651                         ret += sprintf(buf + ret, " fe:%d",
1652                                 port->icount.frame);
1653                 if (port->icount.parity)
1654                         ret += sprintf(buf + ret, " pe:%d",
1655                                 port->icount.parity);
1656                 if (port->icount.brk)
1657                         ret += sprintf(buf + ret, " brk:%d",
1658                                 port->icount.brk);
1659                 if (port->icount.overrun)
1660                         ret += sprintf(buf + ret, " oe:%d",
1661                                 port->icount.overrun);
1662         
1663 #define INFOBIT(bit,str) \
1664         if (port->mctrl & (bit)) \
1665                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1666                         strlen(stat_buf) - 2)
1667 #define STATBIT(bit,str) \
1668         if (status & (bit)) \
1669                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1670                        strlen(stat_buf) - 2)
1671
1672                 stat_buf[0] = '\0';
1673                 stat_buf[1] = '\0';
1674                 INFOBIT(TIOCM_RTS, "|RTS");
1675                 STATBIT(TIOCM_CTS, "|CTS");
1676                 INFOBIT(TIOCM_DTR, "|DTR");
1677                 STATBIT(TIOCM_DSR, "|DSR");
1678                 STATBIT(TIOCM_CAR, "|CD");
1679                 STATBIT(TIOCM_RNG, "|RI");
1680                 if (stat_buf[0])
1681                         stat_buf[0] = ' ';
1682                 strcat(stat_buf, "\n");
1683         
1684                 ret += sprintf(buf + ret, stat_buf);
1685         } else {
1686                 strcat(buf, "\n");
1687                 ret++;
1688         }
1689 #undef STATBIT
1690 #undef INFOBIT
1691         return ret;
1692 }
1693
1694 static int uart_read_proc(char *page, char **start, off_t off,
1695                           int count, int *eof, void *data)
1696 {
1697         struct tty_driver *ttydrv = data;
1698         struct uart_driver *drv = ttydrv->driver_state;
1699         int i, len = 0, l;
1700         off_t begin = 0;
1701
1702         len += sprintf(page, "serinfo:1.0 driver%s%s revision:%s\n",
1703                         "", "", "");
1704         for (i = 0; i < drv->nr && len < PAGE_SIZE - 96; i++) {
1705                 l = uart_line_info(page + len, drv, i);
1706                 len += l;
1707                 if (len + begin > off + count)
1708                         goto done;
1709                 if (len + begin < off) {
1710                         begin += len;
1711                         len = 0;
1712                 }
1713         }
1714         *eof = 1;
1715  done:
1716         if (off >= len + begin)
1717                 return 0;
1718         *start = page + (off - begin);
1719         return (count < begin + len - off) ? count : (begin + len - off);
1720 }
1721 #endif
1722
1723 #ifdef CONFIG_SERIAL_CORE_CONSOLE
1724 /*
1725  *      Check whether an invalid uart number has been specified, and
1726  *      if so, search for the first available port that does have
1727  *      console support.
1728  */
1729 struct uart_port * __init
1730 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1731 {
1732         int idx = co->index;
1733
1734         if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1735                                      ports[idx].membase == NULL))
1736                 for (idx = 0; idx < nr; idx++)
1737                         if (ports[idx].iobase != 0 ||
1738                             ports[idx].membase != NULL)
1739                                 break;
1740
1741         co->index = idx;
1742
1743         return ports + idx;
1744 }
1745
1746 /**
1747  *      uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1748  *      @options: pointer to option string
1749  *      @baud: pointer to an 'int' variable for the baud rate.
1750  *      @parity: pointer to an 'int' variable for the parity.
1751  *      @bits: pointer to an 'int' variable for the number of data bits.
1752  *      @flow: pointer to an 'int' variable for the flow control character.
1753  *
1754  *      uart_parse_options decodes a string containing the serial console
1755  *      options.  The format of the string is <baud><parity><bits><flow>,
1756  *      eg: 115200n8r
1757  */
1758 void __init
1759 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1760 {
1761         char *s = options;
1762
1763         *baud = simple_strtoul(s, NULL, 10);
1764         while (*s >= '0' && *s <= '9')
1765                 s++;
1766         if (*s)
1767                 *parity = *s++;
1768         if (*s)
1769                 *bits = *s++ - '0';
1770         if (*s)
1771                 *flow = *s;
1772 }
1773
1774 struct baud_rates {
1775         unsigned int rate;
1776         unsigned int cflag;
1777 };
1778
1779 static struct baud_rates baud_rates[] = {
1780         { 921600, B921600 },
1781         { 460800, B460800 },
1782         { 230400, B230400 },
1783         { 115200, B115200 },
1784         {  57600, B57600  },
1785         {  38400, B38400  },
1786         {  19200, B19200  },
1787         {   9600, B9600   },
1788         {   4800, B4800   },
1789         {   2400, B2400   },
1790         {   1200, B1200   },
1791         {      0, B38400  }
1792 };
1793
1794 /**
1795  *      uart_set_options - setup the serial console parameters
1796  *      @port: pointer to the serial ports uart_port structure
1797  *      @co: console pointer
1798  *      @baud: baud rate
1799  *      @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1800  *      @bits: number of data bits
1801  *      @flow: flow control character - 'r' (rts)
1802  */
1803 int __init
1804 uart_set_options(struct uart_port *port, struct console *co,
1805                  int baud, int parity, int bits, int flow)
1806 {
1807         struct termios termios;
1808         int i;
1809
1810         /*
1811          * Ensure that the serial console lock is initialised
1812          * early.
1813          */
1814         spin_lock_init(&port->lock);
1815
1816         memset(&termios, 0, sizeof(struct termios));
1817
1818         termios.c_cflag = CREAD | HUPCL | CLOCAL;
1819
1820         /*
1821          * Construct a cflag setting.
1822          */
1823         for (i = 0; baud_rates[i].rate; i++)
1824                 if (baud_rates[i].rate <= baud)
1825                         break;
1826
1827         termios.c_cflag |= baud_rates[i].cflag;
1828
1829         if (bits == 7)
1830                 termios.c_cflag |= CS7;
1831         else
1832                 termios.c_cflag |= CS8;
1833
1834         switch (parity) {
1835         case 'o': case 'O':
1836                 termios.c_cflag |= PARODD;
1837                 /*fall through*/
1838         case 'e': case 'E':
1839                 termios.c_cflag |= PARENB;
1840                 break;
1841         }
1842
1843         if (flow == 'r')
1844                 termios.c_cflag |= CRTSCTS;
1845
1846         port->ops->set_termios(port, &termios, NULL);
1847         co->cflag = termios.c_cflag;
1848
1849         return 0;
1850 }
1851 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1852
1853 static void uart_change_pm(struct uart_state *state, int pm_state)
1854 {
1855         struct uart_port *port = state->port;
1856         if (port->ops->pm)
1857                 port->ops->pm(port, pm_state, state->pm_state);
1858         state->pm_state = pm_state;
1859 }
1860
1861 int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
1862 {
1863         struct uart_state *state = drv->state + port->line;
1864
1865         down(&state->sem);
1866
1867         if (state->info && state->info->flags & UIF_INITIALIZED) {
1868                 struct uart_ops *ops = port->ops;
1869
1870                 spin_lock_irq(&port->lock);
1871                 ops->stop_tx(port);
1872                 ops->set_mctrl(port, 0);
1873                 ops->stop_rx(port);
1874                 spin_unlock_irq(&port->lock);
1875
1876                 /*
1877                  * Wait for the transmitter to empty.
1878                  */
1879                 while (!ops->tx_empty(port)) {
1880                         msleep(10);
1881                 }
1882
1883                 ops->shutdown(port);
1884         }
1885
1886         /*
1887          * Disable the console device before suspending.
1888          */
1889         if (uart_console(port))
1890                 console_stop(port->cons);
1891
1892         uart_change_pm(state, 3);
1893
1894         up(&state->sem);
1895
1896         return 0;
1897 }
1898
1899 int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
1900 {
1901         struct uart_state *state = drv->state + port->line;
1902
1903         down(&state->sem);
1904
1905         uart_change_pm(state, 0);
1906
1907         /*
1908          * Re-enable the console device after suspending.
1909          */
1910         if (uart_console(port)) {
1911                 struct termios termios;
1912
1913                 /*
1914                  * First try to use the console cflag setting.
1915                  */
1916                 memset(&termios, 0, sizeof(struct termios));
1917                 termios.c_cflag = port->cons->cflag;
1918
1919                 /*
1920                  * If that's unset, use the tty termios setting.
1921                  */
1922                 if (state->info && state->info->tty && termios.c_cflag == 0)
1923                         termios = *state->info->tty->termios;
1924
1925                 port->ops->set_termios(port, &termios, NULL);
1926                 console_start(port->cons);
1927         }
1928
1929         if (state->info && state->info->flags & UIF_INITIALIZED) {
1930                 struct uart_ops *ops = port->ops;
1931
1932                 ops->set_mctrl(port, 0);
1933                 ops->startup(port);
1934                 uart_change_speed(state, NULL);
1935                 spin_lock_irq(&port->lock);
1936                 ops->set_mctrl(port, port->mctrl);
1937                 ops->start_tx(port);
1938                 spin_unlock_irq(&port->lock);
1939         }
1940
1941         up(&state->sem);
1942
1943         return 0;
1944 }
1945
1946 static inline void
1947 uart_report_port(struct uart_driver *drv, struct uart_port *port)
1948 {
1949         char address[64];
1950
1951         switch (port->iotype) {
1952         case UPIO_PORT:
1953                 snprintf(address, sizeof(address),
1954                          "I/O 0x%x", port->iobase);
1955                 break;
1956         case UPIO_HUB6:
1957                 snprintf(address, sizeof(address),
1958                          "I/O 0x%x offset 0x%x", port->iobase, port->hub6);
1959                 break;
1960         case UPIO_MEM:
1961         case UPIO_MEM32:
1962         case UPIO_AU:
1963                 snprintf(address, sizeof(address),
1964                          "MMIO 0x%lx", port->mapbase);
1965                 break;
1966         default:
1967                 strlcpy(address, "*unknown*", sizeof(address));
1968                 break;
1969         }
1970
1971         printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
1972                port->dev ? port->dev->bus_id : "",
1973                port->dev ? ": " : "",
1974                drv->dev_name, port->line, address, port->irq, uart_type(port));
1975 }
1976
1977 static void
1978 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
1979                     struct uart_port *port)
1980 {
1981         unsigned int flags;
1982
1983         /*
1984          * If there isn't a port here, don't do anything further.
1985          */
1986         if (!port->iobase && !port->mapbase && !port->membase)
1987                 return;
1988
1989         /*
1990          * Now do the auto configuration stuff.  Note that config_port
1991          * is expected to claim the resources and map the port for us.
1992          */
1993         flags = UART_CONFIG_TYPE;
1994         if (port->flags & UPF_AUTO_IRQ)
1995                 flags |= UART_CONFIG_IRQ;
1996         if (port->flags & UPF_BOOT_AUTOCONF) {
1997                 port->type = PORT_UNKNOWN;
1998                 port->ops->config_port(port, flags);
1999         }
2000
2001         if (port->type != PORT_UNKNOWN) {
2002                 unsigned long flags;
2003
2004                 uart_report_port(drv, port);
2005
2006                 /*
2007                  * Ensure that the modem control lines are de-activated.
2008                  * We probably don't need a spinlock around this, but
2009                  */
2010                 spin_lock_irqsave(&port->lock, flags);
2011                 port->ops->set_mctrl(port, 0);
2012                 spin_unlock_irqrestore(&port->lock, flags);
2013
2014                 /*
2015                  * Power down all ports by default, except the
2016                  * console if we have one.
2017                  */
2018                 if (!uart_console(port))
2019                         uart_change_pm(state, 3);
2020         }
2021 }
2022
2023 /*
2024  * This reverses the effects of uart_configure_port, hanging up the
2025  * port before removal.
2026  */
2027 static void
2028 uart_unconfigure_port(struct uart_driver *drv, struct uart_state *state)
2029 {
2030         struct uart_port *port = state->port;
2031         struct uart_info *info = state->info;
2032
2033         if (info && info->tty)
2034                 tty_vhangup(info->tty);
2035
2036         down(&state->sem);
2037
2038         state->info = NULL;
2039
2040         /*
2041          * Free the port IO and memory resources, if any.
2042          */
2043         if (port->type != PORT_UNKNOWN)
2044                 port->ops->release_port(port);
2045
2046         /*
2047          * Indicate that there isn't a port here anymore.
2048          */
2049         port->type = PORT_UNKNOWN;
2050
2051         /*
2052          * Kill the tasklet, and free resources.
2053          */
2054         if (info) {
2055                 tasklet_kill(&info->tlet);
2056                 kfree(info);
2057         }
2058
2059         up(&state->sem);
2060 }
2061
2062 static struct tty_operations uart_ops = {
2063         .open           = uart_open,
2064         .close          = uart_close,
2065         .write          = uart_write,
2066         .put_char       = uart_put_char,
2067         .flush_chars    = uart_flush_chars,
2068         .write_room     = uart_write_room,
2069         .chars_in_buffer= uart_chars_in_buffer,
2070         .flush_buffer   = uart_flush_buffer,
2071         .ioctl          = uart_ioctl,
2072         .throttle       = uart_throttle,
2073         .unthrottle     = uart_unthrottle,
2074         .send_xchar     = uart_send_xchar,
2075         .set_termios    = uart_set_termios,
2076         .stop           = uart_stop,
2077         .start          = uart_start,
2078         .hangup         = uart_hangup,
2079         .break_ctl      = uart_break_ctl,
2080         .wait_until_sent= uart_wait_until_sent,
2081 #ifdef CONFIG_PROC_FS
2082         .read_proc      = uart_read_proc,
2083 #endif
2084         .tiocmget       = uart_tiocmget,
2085         .tiocmset       = uart_tiocmset,
2086 };
2087
2088 /**
2089  *      uart_register_driver - register a driver with the uart core layer
2090  *      @drv: low level driver structure
2091  *
2092  *      Register a uart driver with the core driver.  We in turn register
2093  *      with the tty layer, and initialise the core driver per-port state.
2094  *
2095  *      We have a proc file in /proc/tty/driver which is named after the
2096  *      normal driver.
2097  *
2098  *      drv->port should be NULL, and the per-port structures should be
2099  *      registered using uart_add_one_port after this call has succeeded.
2100  */
2101 int uart_register_driver(struct uart_driver *drv)
2102 {
2103         struct tty_driver *normal = NULL;
2104         int i, retval;
2105
2106         BUG_ON(drv->state);
2107
2108         /*
2109          * Maybe we should be using a slab cache for this, especially if
2110          * we have a large number of ports to handle.
2111          */
2112         drv->state = kmalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2113         retval = -ENOMEM;
2114         if (!drv->state)
2115                 goto out;
2116
2117         memset(drv->state, 0, sizeof(struct uart_state) * drv->nr);
2118
2119         normal  = alloc_tty_driver(drv->nr);
2120         if (!normal)
2121                 goto out;
2122
2123         drv->tty_driver = normal;
2124
2125         normal->owner           = drv->owner;
2126         normal->driver_name     = drv->driver_name;
2127         normal->devfs_name      = drv->devfs_name;
2128         normal->name            = drv->dev_name;
2129         normal->major           = drv->major;
2130         normal->minor_start     = drv->minor;
2131         normal->type            = TTY_DRIVER_TYPE_SERIAL;
2132         normal->subtype         = SERIAL_TYPE_NORMAL;
2133         normal->init_termios    = tty_std_termios;
2134         normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2135         normal->flags           = TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS;
2136         normal->driver_state    = drv;
2137         tty_set_operations(normal, &uart_ops);
2138
2139         /*
2140          * Initialise the UART state(s).
2141          */
2142         for (i = 0; i < drv->nr; i++) {
2143                 struct uart_state *state = drv->state + i;
2144
2145                 state->close_delay     = 500;   /* .5 seconds */
2146                 state->closing_wait    = 30000; /* 30 seconds */
2147
2148                 init_MUTEX(&state->sem);
2149         }
2150
2151         retval = tty_register_driver(normal);
2152  out:
2153         if (retval < 0) {
2154                 put_tty_driver(normal);
2155                 kfree(drv->state);
2156         }
2157         return retval;
2158 }
2159
2160 /**
2161  *      uart_unregister_driver - remove a driver from the uart core layer
2162  *      @drv: low level driver structure
2163  *
2164  *      Remove all references to a driver from the core driver.  The low
2165  *      level driver must have removed all its ports via the
2166  *      uart_remove_one_port() if it registered them with uart_add_one_port().
2167  *      (ie, drv->port == NULL)
2168  */
2169 void uart_unregister_driver(struct uart_driver *drv)
2170 {
2171         struct tty_driver *p = drv->tty_driver;
2172         tty_unregister_driver(p);
2173         put_tty_driver(p);
2174         kfree(drv->state);
2175         drv->tty_driver = NULL;
2176 }
2177
2178 struct tty_driver *uart_console_device(struct console *co, int *index)
2179 {
2180         struct uart_driver *p = co->data;
2181         *index = co->index;
2182         return p->tty_driver;
2183 }
2184
2185 /**
2186  *      uart_add_one_port - attach a driver-defined port structure
2187  *      @drv: pointer to the uart low level driver structure for this port
2188  *      @port: uart port structure to use for this port.
2189  *
2190  *      This allows the driver to register its own uart_port structure
2191  *      with the core driver.  The main purpose is to allow the low
2192  *      level uart drivers to expand uart_port, rather than having yet
2193  *      more levels of structures.
2194  */
2195 int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
2196 {
2197         struct uart_state *state;
2198         int ret = 0;
2199
2200         BUG_ON(in_interrupt());
2201
2202         if (port->line >= drv->nr)
2203                 return -EINVAL;
2204
2205         state = drv->state + port->line;
2206
2207         down(&port_sem);
2208         if (state->port) {
2209                 ret = -EINVAL;
2210                 goto out;
2211         }
2212
2213         state->port = port;
2214
2215         port->cons = drv->cons;
2216         port->info = state->info;
2217
2218         /*
2219          * If this port is a console, then the spinlock is already
2220          * initialised.
2221          */
2222         if (!uart_console(port))
2223                 spin_lock_init(&port->lock);
2224
2225         uart_configure_port(drv, state, port);
2226
2227         /*
2228          * Register the port whether it's detected or not.  This allows
2229          * setserial to be used to alter this ports parameters.
2230          */
2231         tty_register_device(drv->tty_driver, port->line, port->dev);
2232
2233         /*
2234          * If this driver supports console, and it hasn't been
2235          * successfully registered yet, try to re-register it.
2236          * It may be that the port was not available.
2237          */
2238         if (port->type != PORT_UNKNOWN &&
2239             port->cons && !(port->cons->flags & CON_ENABLED))
2240                 register_console(port->cons);
2241
2242  out:
2243         up(&port_sem);
2244
2245         return ret;
2246 }
2247
2248 /**
2249  *      uart_remove_one_port - detach a driver defined port structure
2250  *      @drv: pointer to the uart low level driver structure for this port
2251  *      @port: uart port structure for this port
2252  *
2253  *      This unhooks (and hangs up) the specified port structure from the
2254  *      core driver.  No further calls will be made to the low-level code
2255  *      for this port.
2256  */
2257 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
2258 {
2259         struct uart_state *state = drv->state + port->line;
2260
2261         BUG_ON(in_interrupt());
2262
2263         if (state->port != port)
2264                 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2265                         state->port, port);
2266
2267         down(&port_sem);
2268
2269         /*
2270          * Remove the devices from devfs
2271          */
2272         tty_unregister_device(drv->tty_driver, port->line);
2273
2274         uart_unconfigure_port(drv, state);
2275         state->port = NULL;
2276         up(&port_sem);
2277
2278         return 0;
2279 }
2280
2281 /*
2282  *      Are the two ports equivalent?
2283  */
2284 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2285 {
2286         if (port1->iotype != port2->iotype)
2287                 return 0;
2288
2289         switch (port1->iotype) {
2290         case UPIO_PORT:
2291                 return (port1->iobase == port2->iobase);
2292         case UPIO_HUB6:
2293                 return (port1->iobase == port2->iobase) &&
2294                        (port1->hub6   == port2->hub6);
2295         case UPIO_MEM:
2296                 return (port1->membase == port2->membase);
2297         }
2298         return 0;
2299 }
2300 EXPORT_SYMBOL(uart_match_port);
2301
2302 EXPORT_SYMBOL(uart_write_wakeup);
2303 EXPORT_SYMBOL(uart_register_driver);
2304 EXPORT_SYMBOL(uart_unregister_driver);
2305 EXPORT_SYMBOL(uart_suspend_port);
2306 EXPORT_SYMBOL(uart_resume_port);
2307 EXPORT_SYMBOL(uart_add_one_port);
2308 EXPORT_SYMBOL(uart_remove_one_port);
2309
2310 MODULE_DESCRIPTION("Serial driver core");
2311 MODULE_LICENSE("GPL");