drm: Core vsync: Don't clobber target sequence number when scheduling signal.
[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/module.h>
26 #include <linux/tty.h>
27 #include <linux/slab.h>
28 #include <linux/init.h>
29 #include <linux/console.h>
30 #include <linux/serial_core.h>
31 #include <linux/smp_lock.h>
32 #include <linux/device.h>
33 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
34 #include <linux/delay.h>
35 #include <linux/mutex.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 DEFINE_MUTEX(port_mutex);
51
52 /*
53  * lockdep: port->lock is initialized in two places, but we
54  *          want only one lock-class:
55  */
56 static struct lock_class_key port_lock_key;
57
58 #define HIGH_BITS_OFFSET        ((sizeof(long)-sizeof(int))*8)
59
60 #define uart_users(state)       ((state)->count + ((state)->info ? (state)->info->blocked_open : 0))
61
62 #ifdef CONFIG_SERIAL_CORE_CONSOLE
63 #define uart_console(port)      ((port)->cons && (port)->cons->index == (port)->line)
64 #else
65 #define uart_console(port)      (0)
66 #endif
67
68 static void uart_change_speed(struct uart_state *state, struct termios *old_termios);
69 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
70 static void uart_change_pm(struct uart_state *state, int pm_state);
71
72 /*
73  * This routine is used by the interrupt handler to schedule processing in
74  * the software interrupt portion of the driver.
75  */
76 void uart_write_wakeup(struct uart_port *port)
77 {
78         struct uart_info *info = port->info;
79         /*
80          * This means you called this function _after_ the port was
81          * closed.  No cookie for you.
82          */
83         BUG_ON(!info);
84         tasklet_schedule(&info->tlet);
85 }
86
87 static void uart_stop(struct tty_struct *tty)
88 {
89         struct uart_state *state = tty->driver_data;
90         struct uart_port *port = state->port;
91         unsigned long flags;
92
93         spin_lock_irqsave(&port->lock, flags);
94         port->ops->stop_tx(port);
95         spin_unlock_irqrestore(&port->lock, flags);
96 }
97
98 static void __uart_start(struct tty_struct *tty)
99 {
100         struct uart_state *state = tty->driver_data;
101         struct uart_port *port = state->port;
102
103         if (!uart_circ_empty(&state->info->xmit) && state->info->xmit.buf &&
104             !tty->stopped && !tty->hw_stopped)
105                 port->ops->start_tx(port);
106 }
107
108 static void uart_start(struct tty_struct *tty)
109 {
110         struct uart_state *state = tty->driver_data;
111         struct uart_port *port = state->port;
112         unsigned long flags;
113
114         spin_lock_irqsave(&port->lock, flags);
115         __uart_start(tty);
116         spin_unlock_irqrestore(&port->lock, flags);
117 }
118
119 static void uart_tasklet_action(unsigned long data)
120 {
121         struct uart_state *state = (struct uart_state *)data;
122         tty_wakeup(state->info->tty);
123 }
124
125 static inline void
126 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
127 {
128         unsigned long flags;
129         unsigned int old;
130
131         spin_lock_irqsave(&port->lock, flags);
132         old = port->mctrl;
133         port->mctrl = (old & ~clear) | set;
134         if (old != port->mctrl)
135                 port->ops->set_mctrl(port, port->mctrl);
136         spin_unlock_irqrestore(&port->lock, flags);
137 }
138
139 #define uart_set_mctrl(port,set)        uart_update_mctrl(port,set,0)
140 #define uart_clear_mctrl(port,clear)    uart_update_mctrl(port,0,clear)
141
142 /*
143  * Startup the port.  This will be called once per open.  All calls
144  * will be serialised by the per-port semaphore.
145  */
146 static int uart_startup(struct uart_state *state, int init_hw)
147 {
148         struct uart_info *info = state->info;
149         struct uart_port *port = state->port;
150         unsigned long page;
151         int retval = 0;
152
153         if (info->flags & UIF_INITIALIZED)
154                 return 0;
155
156         /*
157          * Set the TTY IO error marker - we will only clear this
158          * once we have successfully opened the port.  Also set
159          * up the tty->alt_speed kludge
160          */
161         set_bit(TTY_IO_ERROR, &info->tty->flags);
162
163         if (port->type == PORT_UNKNOWN)
164                 return 0;
165
166         /*
167          * Initialise and allocate the transmit and temporary
168          * buffer.
169          */
170         if (!info->xmit.buf) {
171                 page = get_zeroed_page(GFP_KERNEL);
172                 if (!page)
173                         return -ENOMEM;
174
175                 info->xmit.buf = (unsigned char *) page;
176                 uart_circ_clear(&info->xmit);
177         }
178
179         retval = port->ops->startup(port);
180         if (retval == 0) {
181                 if (init_hw) {
182                         /*
183                          * Initialise the hardware port settings.
184                          */
185                         uart_change_speed(state, NULL);
186
187                         /*
188                          * Setup the RTS and DTR signals once the
189                          * port is open and ready to respond.
190                          */
191                         if (info->tty->termios->c_cflag & CBAUD)
192                                 uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
193                 }
194
195                 if (info->flags & UIF_CTS_FLOW) {
196                         spin_lock_irq(&port->lock);
197                         if (!(port->ops->get_mctrl(port) & TIOCM_CTS))
198                                 info->tty->hw_stopped = 1;
199                         spin_unlock_irq(&port->lock);
200                 }
201
202                 info->flags |= UIF_INITIALIZED;
203
204                 clear_bit(TTY_IO_ERROR, &info->tty->flags);
205         }
206
207         if (retval && capable(CAP_SYS_ADMIN))
208                 retval = 0;
209
210         return retval;
211 }
212
213 /*
214  * This routine will shutdown a serial port; interrupts are disabled, and
215  * DTR is dropped if the hangup on close termio flag is on.  Calls to
216  * uart_shutdown are serialised by the per-port semaphore.
217  */
218 static void uart_shutdown(struct uart_state *state)
219 {
220         struct uart_info *info = state->info;
221         struct uart_port *port = state->port;
222
223         /*
224          * Set the TTY IO error marker
225          */
226         if (info->tty)
227                 set_bit(TTY_IO_ERROR, &info->tty->flags);
228
229         if (info->flags & UIF_INITIALIZED) {
230                 info->flags &= ~UIF_INITIALIZED;
231
232                 /*
233                  * Turn off DTR and RTS early.
234                  */
235                 if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
236                         uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
237
238                 /*
239                  * clear delta_msr_wait queue to avoid mem leaks: we may free
240                  * the irq here so the queue might never be woken up.  Note
241                  * that we won't end up waiting on delta_msr_wait again since
242                  * any outstanding file descriptors should be pointing at
243                  * hung_up_tty_fops now.
244                  */
245                 wake_up_interruptible(&info->delta_msr_wait);
246
247                 /*
248                  * Free the IRQ and disable the port.
249                  */
250                 port->ops->shutdown(port);
251
252                 /*
253                  * Ensure that the IRQ handler isn't running on another CPU.
254                  */
255                 synchronize_irq(port->irq);
256         }
257
258         /*
259          * kill off our tasklet
260          */
261         tasklet_kill(&info->tlet);
262
263         /*
264          * Free the transmit buffer page.
265          */
266         if (info->xmit.buf) {
267                 free_page((unsigned long)info->xmit.buf);
268                 info->xmit.buf = NULL;
269         }
270 }
271
272 /**
273  *      uart_update_timeout - update per-port FIFO timeout.
274  *      @port:  uart_port structure describing the port
275  *      @cflag: termios cflag value
276  *      @baud:  speed of the port
277  *
278  *      Set the port FIFO timeout value.  The @cflag value should
279  *      reflect the actual hardware settings.
280  */
281 void
282 uart_update_timeout(struct uart_port *port, unsigned int cflag,
283                     unsigned int baud)
284 {
285         unsigned int bits;
286
287         /* byte size and parity */
288         switch (cflag & CSIZE) {
289         case CS5:
290                 bits = 7;
291                 break;
292         case CS6:
293                 bits = 8;
294                 break;
295         case CS7:
296                 bits = 9;
297                 break;
298         default:
299                 bits = 10;
300                 break; // CS8
301         }
302
303         if (cflag & CSTOPB)
304                 bits++;
305         if (cflag & PARENB)
306                 bits++;
307
308         /*
309          * The total number of bits to be transmitted in the fifo.
310          */
311         bits = bits * port->fifosize;
312
313         /*
314          * Figure the timeout to send the above number of bits.
315          * Add .02 seconds of slop
316          */
317         port->timeout = (HZ * bits) / baud + HZ/50;
318 }
319
320 EXPORT_SYMBOL(uart_update_timeout);
321
322 /**
323  *      uart_get_baud_rate - return baud rate for a particular port
324  *      @port: uart_port structure describing the port in question.
325  *      @termios: desired termios settings.
326  *      @old: old termios (or NULL)
327  *      @min: minimum acceptable baud rate
328  *      @max: maximum acceptable baud rate
329  *
330  *      Decode the termios structure into a numeric baud rate,
331  *      taking account of the magic 38400 baud rate (with spd_*
332  *      flags), and mapping the %B0 rate to 9600 baud.
333  *
334  *      If the new baud rate is invalid, try the old termios setting.
335  *      If it's still invalid, we try 9600 baud.
336  *
337  *      Update the @termios structure to reflect the baud rate
338  *      we're actually going to be using.
339  */
340 unsigned int
341 uart_get_baud_rate(struct uart_port *port, struct termios *termios,
342                    struct termios *old, unsigned int min, unsigned int max)
343 {
344         unsigned int try, baud, altbaud = 38400;
345         upf_t flags = port->flags & UPF_SPD_MASK;
346
347         if (flags == UPF_SPD_HI)
348                 altbaud = 57600;
349         if (flags == UPF_SPD_VHI)
350                 altbaud = 115200;
351         if (flags == UPF_SPD_SHI)
352                 altbaud = 230400;
353         if (flags == UPF_SPD_WARP)
354                 altbaud = 460800;
355
356         for (try = 0; try < 2; try++) {
357                 baud = tty_termios_baud_rate(termios);
358
359                 /*
360                  * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
361                  * Die! Die! Die!
362                  */
363                 if (baud == 38400)
364                         baud = altbaud;
365
366                 /*
367                  * Special case: B0 rate.
368                  */
369                 if (baud == 0)
370                         baud = 9600;
371
372                 if (baud >= min && baud <= max)
373                         return baud;
374
375                 /*
376                  * Oops, the quotient was zero.  Try again with
377                  * the old baud rate if possible.
378                  */
379                 termios->c_cflag &= ~CBAUD;
380                 if (old) {
381                         termios->c_cflag |= old->c_cflag & CBAUD;
382                         old = NULL;
383                         continue;
384                 }
385
386                 /*
387                  * As a last resort, if the quotient is zero,
388                  * default to 9600 bps
389                  */
390                 termios->c_cflag |= B9600;
391         }
392
393         return 0;
394 }
395
396 EXPORT_SYMBOL(uart_get_baud_rate);
397
398 /**
399  *      uart_get_divisor - return uart clock divisor
400  *      @port: uart_port structure describing the port.
401  *      @baud: desired baud rate
402  *
403  *      Calculate the uart clock divisor for the port.
404  */
405 unsigned int
406 uart_get_divisor(struct uart_port *port, unsigned int baud)
407 {
408         unsigned int quot;
409
410         /*
411          * Old custom speed handling.
412          */
413         if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
414                 quot = port->custom_divisor;
415         else
416                 quot = (port->uartclk + (8 * baud)) / (16 * baud);
417
418         return quot;
419 }
420
421 EXPORT_SYMBOL(uart_get_divisor);
422
423 static void
424 uart_change_speed(struct uart_state *state, struct termios *old_termios)
425 {
426         struct tty_struct *tty = state->info->tty;
427         struct uart_port *port = state->port;
428         struct termios *termios;
429
430         /*
431          * If we have no tty, termios, or the port does not exist,
432          * then we can't set the parameters for this port.
433          */
434         if (!tty || !tty->termios || port->type == PORT_UNKNOWN)
435                 return;
436
437         termios = tty->termios;
438
439         /*
440          * Set flags based on termios cflag
441          */
442         if (termios->c_cflag & CRTSCTS)
443                 state->info->flags |= UIF_CTS_FLOW;
444         else
445                 state->info->flags &= ~UIF_CTS_FLOW;
446
447         if (termios->c_cflag & CLOCAL)
448                 state->info->flags &= ~UIF_CHECK_CD;
449         else
450                 state->info->flags |= UIF_CHECK_CD;
451
452         port->ops->set_termios(port, termios, old_termios);
453 }
454
455 static inline void
456 __uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c)
457 {
458         unsigned long flags;
459
460         if (!circ->buf)
461                 return;
462
463         spin_lock_irqsave(&port->lock, flags);
464         if (uart_circ_chars_free(circ) != 0) {
465                 circ->buf[circ->head] = c;
466                 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
467         }
468         spin_unlock_irqrestore(&port->lock, flags);
469 }
470
471 static void uart_put_char(struct tty_struct *tty, unsigned char ch)
472 {
473         struct uart_state *state = tty->driver_data;
474
475         __uart_put_char(state->port, &state->info->xmit, ch);
476 }
477
478 static void uart_flush_chars(struct tty_struct *tty)
479 {
480         uart_start(tty);
481 }
482
483 static int
484 uart_write(struct tty_struct *tty, const unsigned char *buf, int count)
485 {
486         struct uart_state *state = tty->driver_data;
487         struct uart_port *port;
488         struct circ_buf *circ;
489         unsigned long flags;
490         int c, ret = 0;
491
492         /*
493          * This means you called this function _after_ the port was
494          * closed.  No cookie for you.
495          */
496         if (!state || !state->info) {
497                 WARN_ON(1);
498                 return -EL3HLT;
499         }
500
501         port = state->port;
502         circ = &state->info->xmit;
503
504         if (!circ->buf)
505                 return 0;
506
507         spin_lock_irqsave(&port->lock, flags);
508         while (1) {
509                 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
510                 if (count < c)
511                         c = count;
512                 if (c <= 0)
513                         break;
514                 memcpy(circ->buf + circ->head, buf, c);
515                 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
516                 buf += c;
517                 count -= c;
518                 ret += c;
519         }
520         spin_unlock_irqrestore(&port->lock, flags);
521
522         uart_start(tty);
523         return ret;
524 }
525
526 static int uart_write_room(struct tty_struct *tty)
527 {
528         struct uart_state *state = tty->driver_data;
529
530         return uart_circ_chars_free(&state->info->xmit);
531 }
532
533 static int uart_chars_in_buffer(struct tty_struct *tty)
534 {
535         struct uart_state *state = tty->driver_data;
536
537         return uart_circ_chars_pending(&state->info->xmit);
538 }
539
540 static void uart_flush_buffer(struct tty_struct *tty)
541 {
542         struct uart_state *state = tty->driver_data;
543         struct uart_port *port = state->port;
544         unsigned long flags;
545
546         /*
547          * This means you called this function _after_ the port was
548          * closed.  No cookie for you.
549          */
550         if (!state || !state->info) {
551                 WARN_ON(1);
552                 return;
553         }
554
555         DPRINTK("uart_flush_buffer(%d) called\n", tty->index);
556
557         spin_lock_irqsave(&port->lock, flags);
558         uart_circ_clear(&state->info->xmit);
559         spin_unlock_irqrestore(&port->lock, flags);
560         tty_wakeup(tty);
561 }
562
563 /*
564  * This function is used to send a high-priority XON/XOFF character to
565  * the device
566  */
567 static void uart_send_xchar(struct tty_struct *tty, char ch)
568 {
569         struct uart_state *state = tty->driver_data;
570         struct uart_port *port = state->port;
571         unsigned long flags;
572
573         if (port->ops->send_xchar)
574                 port->ops->send_xchar(port, ch);
575         else {
576                 port->x_char = ch;
577                 if (ch) {
578                         spin_lock_irqsave(&port->lock, flags);
579                         port->ops->start_tx(port);
580                         spin_unlock_irqrestore(&port->lock, flags);
581                 }
582         }
583 }
584
585 static void uart_throttle(struct tty_struct *tty)
586 {
587         struct uart_state *state = tty->driver_data;
588
589         if (I_IXOFF(tty))
590                 uart_send_xchar(tty, STOP_CHAR(tty));
591
592         if (tty->termios->c_cflag & CRTSCTS)
593                 uart_clear_mctrl(state->port, TIOCM_RTS);
594 }
595
596 static void uart_unthrottle(struct tty_struct *tty)
597 {
598         struct uart_state *state = tty->driver_data;
599         struct uart_port *port = state->port;
600
601         if (I_IXOFF(tty)) {
602                 if (port->x_char)
603                         port->x_char = 0;
604                 else
605                         uart_send_xchar(tty, START_CHAR(tty));
606         }
607
608         if (tty->termios->c_cflag & CRTSCTS)
609                 uart_set_mctrl(port, TIOCM_RTS);
610 }
611
612 static int uart_get_info(struct uart_state *state,
613                          struct serial_struct __user *retinfo)
614 {
615         struct uart_port *port = state->port;
616         struct serial_struct tmp;
617
618         memset(&tmp, 0, sizeof(tmp));
619         tmp.type            = port->type;
620         tmp.line            = port->line;
621         tmp.port            = port->iobase;
622         if (HIGH_BITS_OFFSET)
623                 tmp.port_high = (long) port->iobase >> HIGH_BITS_OFFSET;
624         tmp.irq             = port->irq;
625         tmp.flags           = port->flags;
626         tmp.xmit_fifo_size  = port->fifosize;
627         tmp.baud_base       = port->uartclk / 16;
628         tmp.close_delay     = state->close_delay / 10;
629         tmp.closing_wait    = state->closing_wait == USF_CLOSING_WAIT_NONE ?
630                                 ASYNC_CLOSING_WAIT_NONE :
631                                 state->closing_wait / 10;
632         tmp.custom_divisor  = port->custom_divisor;
633         tmp.hub6            = port->hub6;
634         tmp.io_type         = port->iotype;
635         tmp.iomem_reg_shift = port->regshift;
636         tmp.iomem_base      = (void *)port->mapbase;
637
638         if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
639                 return -EFAULT;
640         return 0;
641 }
642
643 static int uart_set_info(struct uart_state *state,
644                          struct serial_struct __user *newinfo)
645 {
646         struct serial_struct new_serial;
647         struct uart_port *port = state->port;
648         unsigned long new_port;
649         unsigned int change_irq, change_port, closing_wait;
650         unsigned int old_custom_divisor, close_delay;
651         upf_t old_flags, new_flags;
652         int retval = 0;
653
654         if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
655                 return -EFAULT;
656
657         new_port = new_serial.port;
658         if (HIGH_BITS_OFFSET)
659                 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
660
661         new_serial.irq = irq_canonicalize(new_serial.irq);
662         close_delay = new_serial.close_delay * 10;
663         closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
664                         USF_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
665
666         /*
667          * This semaphore protects state->count.  It is also
668          * very useful to prevent opens.  Also, take the
669          * port configuration semaphore to make sure that a
670          * module insertion/removal doesn't change anything
671          * under us.
672          */
673         mutex_lock(&state->mutex);
674
675         change_irq  = new_serial.irq != port->irq;
676
677         /*
678          * Since changing the 'type' of the port changes its resource
679          * allocations, we should treat type changes the same as
680          * IO port changes.
681          */
682         change_port = new_port != port->iobase ||
683                       (unsigned long)new_serial.iomem_base != port->mapbase ||
684                       new_serial.hub6 != port->hub6 ||
685                       new_serial.io_type != port->iotype ||
686                       new_serial.iomem_reg_shift != port->regshift ||
687                       new_serial.type != port->type;
688
689         old_flags = port->flags;
690         new_flags = new_serial.flags;
691         old_custom_divisor = port->custom_divisor;
692
693         if (!capable(CAP_SYS_ADMIN)) {
694                 retval = -EPERM;
695                 if (change_irq || change_port ||
696                     (new_serial.baud_base != port->uartclk / 16) ||
697                     (close_delay != state->close_delay) ||
698                     (closing_wait != state->closing_wait) ||
699                     (new_serial.xmit_fifo_size &&
700                      new_serial.xmit_fifo_size != port->fifosize) ||
701                     (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
702                         goto exit;
703                 port->flags = ((port->flags & ~UPF_USR_MASK) |
704                                (new_flags & UPF_USR_MASK));
705                 port->custom_divisor = new_serial.custom_divisor;
706                 goto check_and_exit;
707         }
708
709         /*
710          * Ask the low level driver to verify the settings.
711          */
712         if (port->ops->verify_port)
713                 retval = port->ops->verify_port(port, &new_serial);
714
715         if ((new_serial.irq >= NR_IRQS) || (new_serial.irq < 0) ||
716             (new_serial.baud_base < 9600))
717                 retval = -EINVAL;
718
719         if (retval)
720                 goto exit;
721
722         if (change_port || change_irq) {
723                 retval = -EBUSY;
724
725                 /*
726                  * Make sure that we are the sole user of this port.
727                  */
728                 if (uart_users(state) > 1)
729                         goto exit;
730
731                 /*
732                  * We need to shutdown the serial port at the old
733                  * port/type/irq combination.
734                  */
735                 uart_shutdown(state);
736         }
737
738         if (change_port) {
739                 unsigned long old_iobase, old_mapbase;
740                 unsigned int old_type, old_iotype, old_hub6, old_shift;
741
742                 old_iobase = port->iobase;
743                 old_mapbase = port->mapbase;
744                 old_type = port->type;
745                 old_hub6 = port->hub6;
746                 old_iotype = port->iotype;
747                 old_shift = port->regshift;
748
749                 /*
750                  * Free and release old regions
751                  */
752                 if (old_type != PORT_UNKNOWN)
753                         port->ops->release_port(port);
754
755                 port->iobase = new_port;
756                 port->type = new_serial.type;
757                 port->hub6 = new_serial.hub6;
758                 port->iotype = new_serial.io_type;
759                 port->regshift = new_serial.iomem_reg_shift;
760                 port->mapbase = (unsigned long)new_serial.iomem_base;
761
762                 /*
763                  * Claim and map the new regions
764                  */
765                 if (port->type != PORT_UNKNOWN) {
766                         retval = port->ops->request_port(port);
767                 } else {
768                         /* Always success - Jean II */
769                         retval = 0;
770                 }
771
772                 /*
773                  * If we fail to request resources for the
774                  * new port, try to restore the old settings.
775                  */
776                 if (retval && old_type != PORT_UNKNOWN) {
777                         port->iobase = old_iobase;
778                         port->type = old_type;
779                         port->hub6 = old_hub6;
780                         port->iotype = old_iotype;
781                         port->regshift = old_shift;
782                         port->mapbase = old_mapbase;
783                         retval = port->ops->request_port(port);
784                         /*
785                          * If we failed to restore the old settings,
786                          * we fail like this.
787                          */
788                         if (retval)
789                                 port->type = PORT_UNKNOWN;
790
791                         /*
792                          * We failed anyway.
793                          */
794                         retval = -EBUSY;
795                         goto exit;  // Added to return the correct error -Ram Gupta
796                 }
797         }
798
799         port->irq              = new_serial.irq;
800         port->uartclk          = new_serial.baud_base * 16;
801         port->flags            = (port->flags & ~UPF_CHANGE_MASK) |
802                                  (new_flags & UPF_CHANGE_MASK);
803         port->custom_divisor   = new_serial.custom_divisor;
804         state->close_delay     = close_delay;
805         state->closing_wait    = closing_wait;
806         if (new_serial.xmit_fifo_size)
807                 port->fifosize = new_serial.xmit_fifo_size;
808         if (state->info->tty)
809                 state->info->tty->low_latency =
810                         (port->flags & UPF_LOW_LATENCY) ? 1 : 0;
811
812  check_and_exit:
813         retval = 0;
814         if (port->type == PORT_UNKNOWN)
815                 goto exit;
816         if (state->info->flags & UIF_INITIALIZED) {
817                 if (((old_flags ^ port->flags) & UPF_SPD_MASK) ||
818                     old_custom_divisor != port->custom_divisor) {
819                         /*
820                          * If they're setting up a custom divisor or speed,
821                          * instead of clearing it, then bitch about it. No
822                          * need to rate-limit; it's CAP_SYS_ADMIN only.
823                          */
824                         if (port->flags & UPF_SPD_MASK) {
825                                 char buf[64];
826                                 printk(KERN_NOTICE
827                                        "%s sets custom speed on %s. This "
828                                        "is deprecated.\n", current->comm,
829                                        tty_name(state->info->tty, buf));
830                         }
831                         uart_change_speed(state, NULL);
832                 }
833         } else
834                 retval = uart_startup(state, 1);
835  exit:
836         mutex_unlock(&state->mutex);
837         return retval;
838 }
839
840
841 /*
842  * uart_get_lsr_info - get line status register info.
843  * Note: uart_ioctl protects us against hangups.
844  */
845 static int uart_get_lsr_info(struct uart_state *state,
846                              unsigned int __user *value)
847 {
848         struct uart_port *port = state->port;
849         unsigned int result;
850
851         result = port->ops->tx_empty(port);
852
853         /*
854          * If we're about to load something into the transmit
855          * register, we'll pretend the transmitter isn't empty to
856          * avoid a race condition (depending on when the transmit
857          * interrupt happens).
858          */
859         if (port->x_char ||
860             ((uart_circ_chars_pending(&state->info->xmit) > 0) &&
861              !state->info->tty->stopped && !state->info->tty->hw_stopped))
862                 result &= ~TIOCSER_TEMT;
863         
864         return put_user(result, value);
865 }
866
867 static int uart_tiocmget(struct tty_struct *tty, struct file *file)
868 {
869         struct uart_state *state = tty->driver_data;
870         struct uart_port *port = state->port;
871         int result = -EIO;
872
873         mutex_lock(&state->mutex);
874         if ((!file || !tty_hung_up_p(file)) &&
875             !(tty->flags & (1 << TTY_IO_ERROR))) {
876                 result = port->mctrl;
877
878                 spin_lock_irq(&port->lock);
879                 result |= port->ops->get_mctrl(port);
880                 spin_unlock_irq(&port->lock);
881         }
882         mutex_unlock(&state->mutex);
883
884         return result;
885 }
886
887 static int
888 uart_tiocmset(struct tty_struct *tty, struct file *file,
889               unsigned int set, unsigned int clear)
890 {
891         struct uart_state *state = tty->driver_data;
892         struct uart_port *port = state->port;
893         int ret = -EIO;
894
895         mutex_lock(&state->mutex);
896         if ((!file || !tty_hung_up_p(file)) &&
897             !(tty->flags & (1 << TTY_IO_ERROR))) {
898                 uart_update_mctrl(port, set, clear);
899                 ret = 0;
900         }
901         mutex_unlock(&state->mutex);
902         return ret;
903 }
904
905 static void uart_break_ctl(struct tty_struct *tty, int break_state)
906 {
907         struct uart_state *state = tty->driver_data;
908         struct uart_port *port = state->port;
909
910         BUG_ON(!kernel_locked());
911
912         mutex_lock(&state->mutex);
913
914         if (port->type != PORT_UNKNOWN)
915                 port->ops->break_ctl(port, break_state);
916
917         mutex_unlock(&state->mutex);
918 }
919
920 static int uart_do_autoconfig(struct uart_state *state)
921 {
922         struct uart_port *port = state->port;
923         int flags, ret;
924
925         if (!capable(CAP_SYS_ADMIN))
926                 return -EPERM;
927
928         /*
929          * Take the per-port semaphore.  This prevents count from
930          * changing, and hence any extra opens of the port while
931          * we're auto-configuring.
932          */
933         if (mutex_lock_interruptible(&state->mutex))
934                 return -ERESTARTSYS;
935
936         ret = -EBUSY;
937         if (uart_users(state) == 1) {
938                 uart_shutdown(state);
939
940                 /*
941                  * If we already have a port type configured,
942                  * we must release its resources.
943                  */
944                 if (port->type != PORT_UNKNOWN)
945                         port->ops->release_port(port);
946
947                 flags = UART_CONFIG_TYPE;
948                 if (port->flags & UPF_AUTO_IRQ)
949                         flags |= UART_CONFIG_IRQ;
950
951                 /*
952                  * This will claim the ports resources if
953                  * a port is found.
954                  */
955                 port->ops->config_port(port, flags);
956
957                 ret = uart_startup(state, 1);
958         }
959         mutex_unlock(&state->mutex);
960         return ret;
961 }
962
963 /*
964  * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
965  * - mask passed in arg for lines of interest
966  *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
967  * Caller should use TIOCGICOUNT to see which one it was
968  */
969 static int
970 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
971 {
972         struct uart_port *port = state->port;
973         DECLARE_WAITQUEUE(wait, current);
974         struct uart_icount cprev, cnow;
975         int ret;
976
977         /*
978          * note the counters on entry
979          */
980         spin_lock_irq(&port->lock);
981         memcpy(&cprev, &port->icount, sizeof(struct uart_icount));
982
983         /*
984          * Force modem status interrupts on
985          */
986         port->ops->enable_ms(port);
987         spin_unlock_irq(&port->lock);
988
989         add_wait_queue(&state->info->delta_msr_wait, &wait);
990         for (;;) {
991                 spin_lock_irq(&port->lock);
992                 memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
993                 spin_unlock_irq(&port->lock);
994
995                 set_current_state(TASK_INTERRUPTIBLE);
996
997                 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
998                     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
999                     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1000                     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1001                         ret = 0;
1002                         break;
1003                 }
1004
1005                 schedule();
1006
1007                 /* see if a signal did it */
1008                 if (signal_pending(current)) {
1009                         ret = -ERESTARTSYS;
1010                         break;
1011                 }
1012
1013                 cprev = cnow;
1014         }
1015
1016         current->state = TASK_RUNNING;
1017         remove_wait_queue(&state->info->delta_msr_wait, &wait);
1018
1019         return ret;
1020 }
1021
1022 /*
1023  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1024  * Return: write counters to the user passed counter struct
1025  * NB: both 1->0 and 0->1 transitions are counted except for
1026  *     RI where only 0->1 is counted.
1027  */
1028 static int uart_get_count(struct uart_state *state,
1029                           struct serial_icounter_struct __user *icnt)
1030 {
1031         struct serial_icounter_struct icount;
1032         struct uart_icount cnow;
1033         struct uart_port *port = state->port;
1034
1035         spin_lock_irq(&port->lock);
1036         memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
1037         spin_unlock_irq(&port->lock);
1038
1039         icount.cts         = cnow.cts;
1040         icount.dsr         = cnow.dsr;
1041         icount.rng         = cnow.rng;
1042         icount.dcd         = cnow.dcd;
1043         icount.rx          = cnow.rx;
1044         icount.tx          = cnow.tx;
1045         icount.frame       = cnow.frame;
1046         icount.overrun     = cnow.overrun;
1047         icount.parity      = cnow.parity;
1048         icount.brk         = cnow.brk;
1049         icount.buf_overrun = cnow.buf_overrun;
1050
1051         return copy_to_user(icnt, &icount, sizeof(icount)) ? -EFAULT : 0;
1052 }
1053
1054 /*
1055  * Called via sys_ioctl under the BKL.  We can use spin_lock_irq() here.
1056  */
1057 static int
1058 uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
1059            unsigned long arg)
1060 {
1061         struct uart_state *state = tty->driver_data;
1062         void __user *uarg = (void __user *)arg;
1063         int ret = -ENOIOCTLCMD;
1064
1065         BUG_ON(!kernel_locked());
1066
1067         /*
1068          * These ioctls don't rely on the hardware to be present.
1069          */
1070         switch (cmd) {
1071         case TIOCGSERIAL:
1072                 ret = uart_get_info(state, uarg);
1073                 break;
1074
1075         case TIOCSSERIAL:
1076                 ret = uart_set_info(state, uarg);
1077                 break;
1078
1079         case TIOCSERCONFIG:
1080                 ret = uart_do_autoconfig(state);
1081                 break;
1082
1083         case TIOCSERGWILD: /* obsolete */
1084         case TIOCSERSWILD: /* obsolete */
1085                 ret = 0;
1086                 break;
1087         }
1088
1089         if (ret != -ENOIOCTLCMD)
1090                 goto out;
1091
1092         if (tty->flags & (1 << TTY_IO_ERROR)) {
1093                 ret = -EIO;
1094                 goto out;
1095         }
1096
1097         /*
1098          * The following should only be used when hardware is present.
1099          */
1100         switch (cmd) {
1101         case TIOCMIWAIT:
1102                 ret = uart_wait_modem_status(state, arg);
1103                 break;
1104
1105         case TIOCGICOUNT:
1106                 ret = uart_get_count(state, uarg);
1107                 break;
1108         }
1109
1110         if (ret != -ENOIOCTLCMD)
1111                 goto out;
1112
1113         mutex_lock(&state->mutex);
1114
1115         if (tty_hung_up_p(filp)) {
1116                 ret = -EIO;
1117                 goto out_up;
1118         }
1119
1120         /*
1121          * All these rely on hardware being present and need to be
1122          * protected against the tty being hung up.
1123          */
1124         switch (cmd) {
1125         case TIOCSERGETLSR: /* Get line status register */
1126                 ret = uart_get_lsr_info(state, uarg);
1127                 break;
1128
1129         default: {
1130                 struct uart_port *port = state->port;
1131                 if (port->ops->ioctl)
1132                         ret = port->ops->ioctl(port, cmd, arg);
1133                 break;
1134         }
1135         }
1136  out_up:
1137         mutex_unlock(&state->mutex);
1138  out:
1139         return ret;
1140 }
1141
1142 static void uart_set_termios(struct tty_struct *tty, struct termios *old_termios)
1143 {
1144         struct uart_state *state = tty->driver_data;
1145         unsigned long flags;
1146         unsigned int cflag = tty->termios->c_cflag;
1147
1148         BUG_ON(!kernel_locked());
1149
1150         /*
1151          * These are the bits that are used to setup various
1152          * flags in the low level driver.
1153          */
1154 #define RELEVANT_IFLAG(iflag)   ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1155
1156         if ((cflag ^ old_termios->c_cflag) == 0 &&
1157             RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0)
1158                 return;
1159
1160         uart_change_speed(state, old_termios);
1161
1162         /* Handle transition to B0 status */
1163         if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1164                 uart_clear_mctrl(state->port, TIOCM_RTS | TIOCM_DTR);
1165
1166         /* Handle transition away from B0 status */
1167         if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1168                 unsigned int mask = TIOCM_DTR;
1169                 if (!(cflag & CRTSCTS) ||
1170                     !test_bit(TTY_THROTTLED, &tty->flags))
1171                         mask |= TIOCM_RTS;
1172                 uart_set_mctrl(state->port, mask);
1173         }
1174
1175         /* Handle turning off CRTSCTS */
1176         if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1177                 spin_lock_irqsave(&state->port->lock, flags);
1178                 tty->hw_stopped = 0;
1179                 __uart_start(tty);
1180                 spin_unlock_irqrestore(&state->port->lock, flags);
1181         }
1182
1183         /* Handle turning on CRTSCTS */
1184         if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1185                 spin_lock_irqsave(&state->port->lock, flags);
1186                 if (!(state->port->ops->get_mctrl(state->port) & TIOCM_CTS)) {
1187                         tty->hw_stopped = 1;
1188                         state->port->ops->stop_tx(state->port);
1189                 }
1190                 spin_unlock_irqrestore(&state->port->lock, flags);
1191         }
1192
1193 #if 0
1194         /*
1195          * No need to wake up processes in open wait, since they
1196          * sample the CLOCAL flag once, and don't recheck it.
1197          * XXX  It's not clear whether the current behavior is correct
1198          * or not.  Hence, this may change.....
1199          */
1200         if (!(old_termios->c_cflag & CLOCAL) &&
1201             (tty->termios->c_cflag & CLOCAL))
1202                 wake_up_interruptible(&state->info->open_wait);
1203 #endif
1204 }
1205
1206 /*
1207  * In 2.4.5, calls to this will be serialized via the BKL in
1208  *  linux/drivers/char/tty_io.c:tty_release()
1209  *  linux/drivers/char/tty_io.c:do_tty_handup()
1210  */
1211 static void uart_close(struct tty_struct *tty, struct file *filp)
1212 {
1213         struct uart_state *state = tty->driver_data;
1214         struct uart_port *port;
1215         
1216         BUG_ON(!kernel_locked());
1217
1218         if (!state || !state->port)
1219                 return;
1220
1221         port = state->port;
1222
1223         DPRINTK("uart_close(%d) called\n", port->line);
1224
1225         mutex_lock(&state->mutex);
1226
1227         if (tty_hung_up_p(filp))
1228                 goto done;
1229
1230         if ((tty->count == 1) && (state->count != 1)) {
1231                 /*
1232                  * Uh, oh.  tty->count is 1, which means that the tty
1233                  * structure will be freed.  state->count should always
1234                  * be one in these conditions.  If it's greater than
1235                  * one, we've got real problems, since it means the
1236                  * serial port won't be shutdown.
1237                  */
1238                 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1239                        "state->count is %d\n", state->count);
1240                 state->count = 1;
1241         }
1242         if (--state->count < 0) {
1243                 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1244                        tty->name, state->count);
1245                 state->count = 0;
1246         }
1247         if (state->count)
1248                 goto done;
1249
1250         /*
1251          * Now we wait for the transmit buffer to clear; and we notify
1252          * the line discipline to only process XON/XOFF characters by
1253          * setting tty->closing.
1254          */
1255         tty->closing = 1;
1256
1257         if (state->closing_wait != USF_CLOSING_WAIT_NONE)
1258                 tty_wait_until_sent(tty, msecs_to_jiffies(state->closing_wait));
1259
1260         /*
1261          * At this point, we stop accepting input.  To do this, we
1262          * disable the receive line status interrupts.
1263          */
1264         if (state->info->flags & UIF_INITIALIZED) {
1265                 unsigned long flags;
1266                 spin_lock_irqsave(&port->lock, flags);
1267                 port->ops->stop_rx(port);
1268                 spin_unlock_irqrestore(&port->lock, flags);
1269                 /*
1270                  * Before we drop DTR, make sure the UART transmitter
1271                  * has completely drained; this is especially
1272                  * important if there is a transmit FIFO!
1273                  */
1274                 uart_wait_until_sent(tty, port->timeout);
1275         }
1276
1277         uart_shutdown(state);
1278         uart_flush_buffer(tty);
1279
1280         tty_ldisc_flush(tty);   
1281         
1282         tty->closing = 0;
1283         state->info->tty = NULL;
1284
1285         if (state->info->blocked_open) {
1286                 if (state->close_delay)
1287                         msleep_interruptible(state->close_delay);
1288         } else if (!uart_console(port)) {
1289                 uart_change_pm(state, 3);
1290         }
1291
1292         /*
1293          * Wake up anyone trying to open this port.
1294          */
1295         state->info->flags &= ~UIF_NORMAL_ACTIVE;
1296         wake_up_interruptible(&state->info->open_wait);
1297
1298  done:
1299         mutex_unlock(&state->mutex);
1300 }
1301
1302 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1303 {
1304         struct uart_state *state = tty->driver_data;
1305         struct uart_port *port = state->port;
1306         unsigned long char_time, expire;
1307
1308         BUG_ON(!kernel_locked());
1309
1310         if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1311                 return;
1312
1313         /*
1314          * Set the check interval to be 1/5 of the estimated time to
1315          * send a single character, and make it at least 1.  The check
1316          * interval should also be less than the timeout.
1317          *
1318          * Note: we have to use pretty tight timings here to satisfy
1319          * the NIST-PCTS.
1320          */
1321         char_time = (port->timeout - HZ/50) / port->fifosize;
1322         char_time = char_time / 5;
1323         if (char_time == 0)
1324                 char_time = 1;
1325         if (timeout && timeout < char_time)
1326                 char_time = timeout;
1327
1328         /*
1329          * If the transmitter hasn't cleared in twice the approximate
1330          * amount of time to send the entire FIFO, it probably won't
1331          * ever clear.  This assumes the UART isn't doing flow
1332          * control, which is currently the case.  Hence, if it ever
1333          * takes longer than port->timeout, this is probably due to a
1334          * UART bug of some kind.  So, we clamp the timeout parameter at
1335          * 2*port->timeout.
1336          */
1337         if (timeout == 0 || timeout > 2 * port->timeout)
1338                 timeout = 2 * port->timeout;
1339
1340         expire = jiffies + timeout;
1341
1342         DPRINTK("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1343                 port->line, jiffies, expire);
1344
1345         /*
1346          * Check whether the transmitter is empty every 'char_time'.
1347          * 'timeout' / 'expire' give us the maximum amount of time
1348          * we wait.
1349          */
1350         while (!port->ops->tx_empty(port)) {
1351                 msleep_interruptible(jiffies_to_msecs(char_time));
1352                 if (signal_pending(current))
1353                         break;
1354                 if (time_after(jiffies, expire))
1355                         break;
1356         }
1357         set_current_state(TASK_RUNNING); /* might not be needed */
1358 }
1359
1360 /*
1361  * This is called with the BKL held in
1362  *  linux/drivers/char/tty_io.c:do_tty_hangup()
1363  * We're called from the eventd thread, so we can sleep for
1364  * a _short_ time only.
1365  */
1366 static void uart_hangup(struct tty_struct *tty)
1367 {
1368         struct uart_state *state = tty->driver_data;
1369
1370         BUG_ON(!kernel_locked());
1371         DPRINTK("uart_hangup(%d)\n", state->port->line);
1372
1373         mutex_lock(&state->mutex);
1374         if (state->info && state->info->flags & UIF_NORMAL_ACTIVE) {
1375                 uart_flush_buffer(tty);
1376                 uart_shutdown(state);
1377                 state->count = 0;
1378                 state->info->flags &= ~UIF_NORMAL_ACTIVE;
1379                 state->info->tty = NULL;
1380                 wake_up_interruptible(&state->info->open_wait);
1381                 wake_up_interruptible(&state->info->delta_msr_wait);
1382         }
1383         mutex_unlock(&state->mutex);
1384 }
1385
1386 /*
1387  * Copy across the serial console cflag setting into the termios settings
1388  * for the initial open of the port.  This allows continuity between the
1389  * kernel settings, and the settings init adopts when it opens the port
1390  * for the first time.
1391  */
1392 static void uart_update_termios(struct uart_state *state)
1393 {
1394         struct tty_struct *tty = state->info->tty;
1395         struct uart_port *port = state->port;
1396
1397         if (uart_console(port) && port->cons->cflag) {
1398                 tty->termios->c_cflag = port->cons->cflag;
1399                 port->cons->cflag = 0;
1400         }
1401
1402         /*
1403          * If the device failed to grab its irq resources,
1404          * or some other error occurred, don't try to talk
1405          * to the port hardware.
1406          */
1407         if (!(tty->flags & (1 << TTY_IO_ERROR))) {
1408                 /*
1409                  * Make termios settings take effect.
1410                  */
1411                 uart_change_speed(state, NULL);
1412
1413                 /*
1414                  * And finally enable the RTS and DTR signals.
1415                  */
1416                 if (tty->termios->c_cflag & CBAUD)
1417                         uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
1418         }
1419 }
1420
1421 /*
1422  * Block the open until the port is ready.  We must be called with
1423  * the per-port semaphore held.
1424  */
1425 static int
1426 uart_block_til_ready(struct file *filp, struct uart_state *state)
1427 {
1428         DECLARE_WAITQUEUE(wait, current);
1429         struct uart_info *info = state->info;
1430         struct uart_port *port = state->port;
1431         unsigned int mctrl;
1432
1433         info->blocked_open++;
1434         state->count--;
1435
1436         add_wait_queue(&info->open_wait, &wait);
1437         while (1) {
1438                 set_current_state(TASK_INTERRUPTIBLE);
1439
1440                 /*
1441                  * If we have been hung up, tell userspace/restart open.
1442                  */
1443                 if (tty_hung_up_p(filp) || info->tty == NULL)
1444                         break;
1445
1446                 /*
1447                  * If the port has been closed, tell userspace/restart open.
1448                  */
1449                 if (!(info->flags & UIF_INITIALIZED))
1450                         break;
1451
1452                 /*
1453                  * If non-blocking mode is set, or CLOCAL mode is set,
1454                  * we don't want to wait for the modem status lines to
1455                  * indicate that the port is ready.
1456                  *
1457                  * Also, if the port is not enabled/configured, we want
1458                  * to allow the open to succeed here.  Note that we will
1459                  * have set TTY_IO_ERROR for a non-existant port.
1460                  */
1461                 if ((filp->f_flags & O_NONBLOCK) ||
1462                     (info->tty->termios->c_cflag & CLOCAL) ||
1463                     (info->tty->flags & (1 << TTY_IO_ERROR))) {
1464                         break;
1465                 }
1466
1467                 /*
1468                  * Set DTR to allow modem to know we're waiting.  Do
1469                  * not set RTS here - we want to make sure we catch
1470                  * the data from the modem.
1471                  */
1472                 if (info->tty->termios->c_cflag & CBAUD)
1473                         uart_set_mctrl(port, TIOCM_DTR);
1474
1475                 /*
1476                  * and wait for the carrier to indicate that the
1477                  * modem is ready for us.
1478                  */
1479                 spin_lock_irq(&port->lock);
1480                 port->ops->enable_ms(port);
1481                 mctrl = port->ops->get_mctrl(port);
1482                 spin_unlock_irq(&port->lock);
1483                 if (mctrl & TIOCM_CAR)
1484                         break;
1485
1486                 mutex_unlock(&state->mutex);
1487                 schedule();
1488                 mutex_lock(&state->mutex);
1489
1490                 if (signal_pending(current))
1491                         break;
1492         }
1493         set_current_state(TASK_RUNNING);
1494         remove_wait_queue(&info->open_wait, &wait);
1495
1496         state->count++;
1497         info->blocked_open--;
1498
1499         if (signal_pending(current))
1500                 return -ERESTARTSYS;
1501
1502         if (!info->tty || tty_hung_up_p(filp))
1503                 return -EAGAIN;
1504
1505         return 0;
1506 }
1507
1508 static struct uart_state *uart_get(struct uart_driver *drv, int line)
1509 {
1510         struct uart_state *state;
1511         int ret = 0;
1512
1513         state = drv->state + line;
1514         if (mutex_lock_interruptible(&state->mutex)) {
1515                 ret = -ERESTARTSYS;
1516                 goto err;
1517         }
1518
1519         state->count++;
1520         if (!state->port || state->port->flags & UPF_DEAD) {
1521                 ret = -ENXIO;
1522                 goto err_unlock;
1523         }
1524
1525         if (!state->info) {
1526                 state->info = kmalloc(sizeof(struct uart_info), GFP_KERNEL);
1527                 if (state->info) {
1528                         memset(state->info, 0, sizeof(struct uart_info));
1529                         init_waitqueue_head(&state->info->open_wait);
1530                         init_waitqueue_head(&state->info->delta_msr_wait);
1531
1532                         /*
1533                          * Link the info into the other structures.
1534                          */
1535                         state->port->info = state->info;
1536
1537                         tasklet_init(&state->info->tlet, uart_tasklet_action,
1538                                      (unsigned long)state);
1539                 } else {
1540                         ret = -ENOMEM;
1541                         goto err_unlock;
1542                 }
1543         }
1544         return state;
1545
1546  err_unlock:
1547         state->count--;
1548         mutex_unlock(&state->mutex);
1549  err:
1550         return ERR_PTR(ret);
1551 }
1552
1553 /*
1554  * In 2.4.5, calls to uart_open are serialised by the BKL in
1555  *   linux/fs/devices.c:chrdev_open()
1556  * Note that if this fails, then uart_close() _will_ be called.
1557  *
1558  * In time, we want to scrap the "opening nonpresent ports"
1559  * behaviour and implement an alternative way for setserial
1560  * to set base addresses/ports/types.  This will allow us to
1561  * get rid of a certain amount of extra tests.
1562  */
1563 static int uart_open(struct tty_struct *tty, struct file *filp)
1564 {
1565         struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1566         struct uart_state *state;
1567         int retval, line = tty->index;
1568
1569         BUG_ON(!kernel_locked());
1570         DPRINTK("uart_open(%d) called\n", line);
1571
1572         /*
1573          * tty->driver->num won't change, so we won't fail here with
1574          * tty->driver_data set to something non-NULL (and therefore
1575          * we won't get caught by uart_close()).
1576          */
1577         retval = -ENODEV;
1578         if (line >= tty->driver->num)
1579                 goto fail;
1580
1581         /*
1582          * We take the semaphore inside uart_get to guarantee that we won't
1583          * be re-entered while allocating the info structure, or while we
1584          * request any IRQs that the driver may need.  This also has the nice
1585          * side-effect that it delays the action of uart_hangup, so we can
1586          * guarantee that info->tty will always contain something reasonable.
1587          */
1588         state = uart_get(drv, line);
1589         if (IS_ERR(state)) {
1590                 retval = PTR_ERR(state);
1591                 goto fail;
1592         }
1593
1594         /*
1595          * Once we set tty->driver_data here, we are guaranteed that
1596          * uart_close() will decrement the driver module use count.
1597          * Any failures from here onwards should not touch the count.
1598          */
1599         tty->driver_data = state;
1600         tty->low_latency = (state->port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1601         tty->alt_speed = 0;
1602         state->info->tty = tty;
1603
1604         /*
1605          * If the port is in the middle of closing, bail out now.
1606          */
1607         if (tty_hung_up_p(filp)) {
1608                 retval = -EAGAIN;
1609                 state->count--;
1610                 mutex_unlock(&state->mutex);
1611                 goto fail;
1612         }
1613
1614         /*
1615          * Make sure the device is in D0 state.
1616          */
1617         if (state->count == 1)
1618                 uart_change_pm(state, 0);
1619
1620         /*
1621          * Start up the serial port.
1622          */
1623         retval = uart_startup(state, 0);
1624
1625         /*
1626          * If we succeeded, wait until the port is ready.
1627          */
1628         if (retval == 0)
1629                 retval = uart_block_til_ready(filp, state);
1630         mutex_unlock(&state->mutex);
1631
1632         /*
1633          * If this is the first open to succeed, adjust things to suit.
1634          */
1635         if (retval == 0 && !(state->info->flags & UIF_NORMAL_ACTIVE)) {
1636                 state->info->flags |= UIF_NORMAL_ACTIVE;
1637
1638                 uart_update_termios(state);
1639         }
1640
1641  fail:
1642         return retval;
1643 }
1644
1645 static const char *uart_type(struct uart_port *port)
1646 {
1647         const char *str = NULL;
1648
1649         if (port->ops->type)
1650                 str = port->ops->type(port);
1651
1652         if (!str)
1653                 str = "unknown";
1654
1655         return str;
1656 }
1657
1658 #ifdef CONFIG_PROC_FS
1659
1660 static int uart_line_info(char *buf, struct uart_driver *drv, int i)
1661 {
1662         struct uart_state *state = drv->state + i;
1663         struct uart_port *port = state->port;
1664         char stat_buf[32];
1665         unsigned int status;
1666         int mmio, ret;
1667
1668         if (!port)
1669                 return 0;
1670
1671         mmio = port->iotype >= UPIO_MEM;
1672         ret = sprintf(buf, "%d: uart:%s %s%08lX irq:%d",
1673                         port->line, uart_type(port),
1674                         mmio ? "mmio:0x" : "port:",
1675                         mmio ? port->mapbase : (unsigned long) port->iobase,
1676                         port->irq);
1677
1678         if (port->type == PORT_UNKNOWN) {
1679                 strcat(buf, "\n");
1680                 return ret + 1;
1681         }
1682
1683         if(capable(CAP_SYS_ADMIN))
1684         {
1685                 spin_lock_irq(&port->lock);
1686                 status = port->ops->get_mctrl(port);
1687                 spin_unlock_irq(&port->lock);
1688
1689                 ret += sprintf(buf + ret, " tx:%d rx:%d",
1690                                 port->icount.tx, port->icount.rx);
1691                 if (port->icount.frame)
1692                         ret += sprintf(buf + ret, " fe:%d",
1693                                 port->icount.frame);
1694                 if (port->icount.parity)
1695                         ret += sprintf(buf + ret, " pe:%d",
1696                                 port->icount.parity);
1697                 if (port->icount.brk)
1698                         ret += sprintf(buf + ret, " brk:%d",
1699                                 port->icount.brk);
1700                 if (port->icount.overrun)
1701                         ret += sprintf(buf + ret, " oe:%d",
1702                                 port->icount.overrun);
1703         
1704 #define INFOBIT(bit,str) \
1705         if (port->mctrl & (bit)) \
1706                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1707                         strlen(stat_buf) - 2)
1708 #define STATBIT(bit,str) \
1709         if (status & (bit)) \
1710                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1711                        strlen(stat_buf) - 2)
1712
1713                 stat_buf[0] = '\0';
1714                 stat_buf[1] = '\0';
1715                 INFOBIT(TIOCM_RTS, "|RTS");
1716                 STATBIT(TIOCM_CTS, "|CTS");
1717                 INFOBIT(TIOCM_DTR, "|DTR");
1718                 STATBIT(TIOCM_DSR, "|DSR");
1719                 STATBIT(TIOCM_CAR, "|CD");
1720                 STATBIT(TIOCM_RNG, "|RI");
1721                 if (stat_buf[0])
1722                         stat_buf[0] = ' ';
1723                 strcat(stat_buf, "\n");
1724         
1725                 ret += sprintf(buf + ret, stat_buf);
1726         } else {
1727                 strcat(buf, "\n");
1728                 ret++;
1729         }
1730 #undef STATBIT
1731 #undef INFOBIT
1732         return ret;
1733 }
1734
1735 static int uart_read_proc(char *page, char **start, off_t off,
1736                           int count, int *eof, void *data)
1737 {
1738         struct tty_driver *ttydrv = data;
1739         struct uart_driver *drv = ttydrv->driver_state;
1740         int i, len = 0, l;
1741         off_t begin = 0;
1742
1743         len += sprintf(page, "serinfo:1.0 driver%s%s revision:%s\n",
1744                         "", "", "");
1745         for (i = 0; i < drv->nr && len < PAGE_SIZE - 96; i++) {
1746                 l = uart_line_info(page + len, drv, i);
1747                 len += l;
1748                 if (len + begin > off + count)
1749                         goto done;
1750                 if (len + begin < off) {
1751                         begin += len;
1752                         len = 0;
1753                 }
1754         }
1755         *eof = 1;
1756  done:
1757         if (off >= len + begin)
1758                 return 0;
1759         *start = page + (off - begin);
1760         return (count < begin + len - off) ? count : (begin + len - off);
1761 }
1762 #endif
1763
1764 #ifdef CONFIG_SERIAL_CORE_CONSOLE
1765 /*
1766  *      uart_console_write - write a console message to a serial port
1767  *      @port: the port to write the message
1768  *      @s: array of characters
1769  *      @count: number of characters in string to write
1770  *      @write: function to write character to port
1771  */
1772 void uart_console_write(struct uart_port *port, const char *s,
1773                         unsigned int count,
1774                         void (*putchar)(struct uart_port *, int))
1775 {
1776         unsigned int i;
1777
1778         for (i = 0; i < count; i++, s++) {
1779                 if (*s == '\n')
1780                         putchar(port, '\r');
1781                 putchar(port, *s);
1782         }
1783 }
1784 EXPORT_SYMBOL_GPL(uart_console_write);
1785
1786 /*
1787  *      Check whether an invalid uart number has been specified, and
1788  *      if so, search for the first available port that does have
1789  *      console support.
1790  */
1791 struct uart_port * __init
1792 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1793 {
1794         int idx = co->index;
1795
1796         if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1797                                      ports[idx].membase == NULL))
1798                 for (idx = 0; idx < nr; idx++)
1799                         if (ports[idx].iobase != 0 ||
1800                             ports[idx].membase != NULL)
1801                                 break;
1802
1803         co->index = idx;
1804
1805         return ports + idx;
1806 }
1807
1808 /**
1809  *      uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1810  *      @options: pointer to option string
1811  *      @baud: pointer to an 'int' variable for the baud rate.
1812  *      @parity: pointer to an 'int' variable for the parity.
1813  *      @bits: pointer to an 'int' variable for the number of data bits.
1814  *      @flow: pointer to an 'int' variable for the flow control character.
1815  *
1816  *      uart_parse_options decodes a string containing the serial console
1817  *      options.  The format of the string is <baud><parity><bits><flow>,
1818  *      eg: 115200n8r
1819  */
1820 void __init
1821 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1822 {
1823         char *s = options;
1824
1825         *baud = simple_strtoul(s, NULL, 10);
1826         while (*s >= '0' && *s <= '9')
1827                 s++;
1828         if (*s)
1829                 *parity = *s++;
1830         if (*s)
1831                 *bits = *s++ - '0';
1832         if (*s)
1833                 *flow = *s;
1834 }
1835
1836 struct baud_rates {
1837         unsigned int rate;
1838         unsigned int cflag;
1839 };
1840
1841 static const struct baud_rates baud_rates[] = {
1842         { 921600, B921600 },
1843         { 460800, B460800 },
1844         { 230400, B230400 },
1845         { 115200, B115200 },
1846         {  57600, B57600  },
1847         {  38400, B38400  },
1848         {  19200, B19200  },
1849         {   9600, B9600   },
1850         {   4800, B4800   },
1851         {   2400, B2400   },
1852         {   1200, B1200   },
1853         {      0, B38400  }
1854 };
1855
1856 /**
1857  *      uart_set_options - setup the serial console parameters
1858  *      @port: pointer to the serial ports uart_port structure
1859  *      @co: console pointer
1860  *      @baud: baud rate
1861  *      @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1862  *      @bits: number of data bits
1863  *      @flow: flow control character - 'r' (rts)
1864  */
1865 int __init
1866 uart_set_options(struct uart_port *port, struct console *co,
1867                  int baud, int parity, int bits, int flow)
1868 {
1869         struct termios termios;
1870         int i;
1871
1872         /*
1873          * Ensure that the serial console lock is initialised
1874          * early.
1875          */
1876         spin_lock_init(&port->lock);
1877         lockdep_set_class(&port->lock, &port_lock_key);
1878
1879         memset(&termios, 0, sizeof(struct termios));
1880
1881         termios.c_cflag = CREAD | HUPCL | CLOCAL;
1882
1883         /*
1884          * Construct a cflag setting.
1885          */
1886         for (i = 0; baud_rates[i].rate; i++)
1887                 if (baud_rates[i].rate <= baud)
1888                         break;
1889
1890         termios.c_cflag |= baud_rates[i].cflag;
1891
1892         if (bits == 7)
1893                 termios.c_cflag |= CS7;
1894         else
1895                 termios.c_cflag |= CS8;
1896
1897         switch (parity) {
1898         case 'o': case 'O':
1899                 termios.c_cflag |= PARODD;
1900                 /*fall through*/
1901         case 'e': case 'E':
1902                 termios.c_cflag |= PARENB;
1903                 break;
1904         }
1905
1906         if (flow == 'r')
1907                 termios.c_cflag |= CRTSCTS;
1908
1909         port->ops->set_termios(port, &termios, NULL);
1910         co->cflag = termios.c_cflag;
1911
1912         return 0;
1913 }
1914 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1915
1916 static void uart_change_pm(struct uart_state *state, int pm_state)
1917 {
1918         struct uart_port *port = state->port;
1919
1920         if (state->pm_state != pm_state) {
1921                 if (port->ops->pm)
1922                         port->ops->pm(port, pm_state, state->pm_state);
1923                 state->pm_state = pm_state;
1924         }
1925 }
1926
1927 int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
1928 {
1929         struct uart_state *state = drv->state + port->line;
1930
1931         mutex_lock(&state->mutex);
1932
1933 #ifdef CONFIG_DISABLE_CONSOLE_SUSPEND
1934         if (uart_console(port)) {
1935                 mutex_unlock(&state->mutex);
1936                 return 0;
1937         }
1938 #endif
1939
1940         if (state->info && state->info->flags & UIF_INITIALIZED) {
1941                 const struct uart_ops *ops = port->ops;
1942
1943                 state->info->flags = (state->info->flags & ~UIF_INITIALIZED)
1944                                      | UIF_SUSPENDED;
1945
1946                 spin_lock_irq(&port->lock);
1947                 ops->stop_tx(port);
1948                 ops->set_mctrl(port, 0);
1949                 ops->stop_rx(port);
1950                 spin_unlock_irq(&port->lock);
1951
1952                 /*
1953                  * Wait for the transmitter to empty.
1954                  */
1955                 while (!ops->tx_empty(port)) {
1956                         msleep(10);
1957                 }
1958
1959                 ops->shutdown(port);
1960         }
1961
1962         /*
1963          * Disable the console device before suspending.
1964          */
1965         if (uart_console(port))
1966                 console_stop(port->cons);
1967
1968         uart_change_pm(state, 3);
1969
1970         mutex_unlock(&state->mutex);
1971
1972         return 0;
1973 }
1974
1975 int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
1976 {
1977         struct uart_state *state = drv->state + port->line;
1978
1979         mutex_lock(&state->mutex);
1980
1981 #ifdef CONFIG_DISABLE_CONSOLE_SUSPEND
1982         if (uart_console(port)) {
1983                 mutex_unlock(&state->mutex);
1984                 return 0;
1985         }
1986 #endif
1987
1988         uart_change_pm(state, 0);
1989
1990         /*
1991          * Re-enable the console device after suspending.
1992          */
1993         if (uart_console(port)) {
1994                 struct termios termios;
1995
1996                 /*
1997                  * First try to use the console cflag setting.
1998                  */
1999                 memset(&termios, 0, sizeof(struct termios));
2000                 termios.c_cflag = port->cons->cflag;
2001
2002                 /*
2003                  * If that's unset, use the tty termios setting.
2004                  */
2005                 if (state->info && state->info->tty && termios.c_cflag == 0)
2006                         termios = *state->info->tty->termios;
2007
2008                 port->ops->set_termios(port, &termios, NULL);
2009                 console_start(port->cons);
2010         }
2011
2012         if (state->info && state->info->flags & UIF_SUSPENDED) {
2013                 const struct uart_ops *ops = port->ops;
2014                 int ret;
2015
2016                 ops->set_mctrl(port, 0);
2017                 ret = ops->startup(port);
2018                 if (ret == 0) {
2019                         uart_change_speed(state, NULL);
2020                         spin_lock_irq(&port->lock);
2021                         ops->set_mctrl(port, port->mctrl);
2022                         ops->start_tx(port);
2023                         spin_unlock_irq(&port->lock);
2024                         state->info->flags |= UIF_INITIALIZED;
2025                 } else {
2026                         /*
2027                          * Failed to resume - maybe hardware went away?
2028                          * Clear the "initialized" flag so we won't try
2029                          * to call the low level drivers shutdown method.
2030                          */
2031                         uart_shutdown(state);
2032                 }
2033
2034                 state->info->flags &= ~UIF_SUSPENDED;
2035         }
2036
2037         mutex_unlock(&state->mutex);
2038
2039         return 0;
2040 }
2041
2042 static inline void
2043 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2044 {
2045         char address[64];
2046
2047         switch (port->iotype) {
2048         case UPIO_PORT:
2049                 snprintf(address, sizeof(address),
2050                          "I/O 0x%x", port->iobase);
2051                 break;
2052         case UPIO_HUB6:
2053                 snprintf(address, sizeof(address),
2054                          "I/O 0x%x offset 0x%x", port->iobase, port->hub6);
2055                 break;
2056         case UPIO_MEM:
2057         case UPIO_MEM32:
2058         case UPIO_AU:
2059         case UPIO_TSI:
2060                 snprintf(address, sizeof(address),
2061                          "MMIO 0x%lx", port->mapbase);
2062                 break;
2063         default:
2064                 strlcpy(address, "*unknown*", sizeof(address));
2065                 break;
2066         }
2067
2068         printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2069                port->dev ? port->dev->bus_id : "",
2070                port->dev ? ": " : "",
2071                drv->dev_name, port->line, address, port->irq, uart_type(port));
2072 }
2073
2074 static void
2075 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2076                     struct uart_port *port)
2077 {
2078         unsigned int flags;
2079
2080         /*
2081          * If there isn't a port here, don't do anything further.
2082          */
2083         if (!port->iobase && !port->mapbase && !port->membase)
2084                 return;
2085
2086         /*
2087          * Now do the auto configuration stuff.  Note that config_port
2088          * is expected to claim the resources and map the port for us.
2089          */
2090         flags = UART_CONFIG_TYPE;
2091         if (port->flags & UPF_AUTO_IRQ)
2092                 flags |= UART_CONFIG_IRQ;
2093         if (port->flags & UPF_BOOT_AUTOCONF) {
2094                 port->type = PORT_UNKNOWN;
2095                 port->ops->config_port(port, flags);
2096         }
2097
2098         if (port->type != PORT_UNKNOWN) {
2099                 unsigned long flags;
2100
2101                 uart_report_port(drv, port);
2102
2103                 /*
2104                  * Ensure that the modem control lines are de-activated.
2105                  * We probably don't need a spinlock around this, but
2106                  */
2107                 spin_lock_irqsave(&port->lock, flags);
2108                 port->ops->set_mctrl(port, 0);
2109                 spin_unlock_irqrestore(&port->lock, flags);
2110
2111                 /*
2112                  * Power down all ports by default, except the
2113                  * console if we have one.
2114                  */
2115                 if (!uart_console(port))
2116                         uart_change_pm(state, 3);
2117         }
2118 }
2119
2120 static const struct tty_operations uart_ops = {
2121         .open           = uart_open,
2122         .close          = uart_close,
2123         .write          = uart_write,
2124         .put_char       = uart_put_char,
2125         .flush_chars    = uart_flush_chars,
2126         .write_room     = uart_write_room,
2127         .chars_in_buffer= uart_chars_in_buffer,
2128         .flush_buffer   = uart_flush_buffer,
2129         .ioctl          = uart_ioctl,
2130         .throttle       = uart_throttle,
2131         .unthrottle     = uart_unthrottle,
2132         .send_xchar     = uart_send_xchar,
2133         .set_termios    = uart_set_termios,
2134         .stop           = uart_stop,
2135         .start          = uart_start,
2136         .hangup         = uart_hangup,
2137         .break_ctl      = uart_break_ctl,
2138         .wait_until_sent= uart_wait_until_sent,
2139 #ifdef CONFIG_PROC_FS
2140         .read_proc      = uart_read_proc,
2141 #endif
2142         .tiocmget       = uart_tiocmget,
2143         .tiocmset       = uart_tiocmset,
2144 };
2145
2146 /**
2147  *      uart_register_driver - register a driver with the uart core layer
2148  *      @drv: low level driver structure
2149  *
2150  *      Register a uart driver with the core driver.  We in turn register
2151  *      with the tty layer, and initialise the core driver per-port state.
2152  *
2153  *      We have a proc file in /proc/tty/driver which is named after the
2154  *      normal driver.
2155  *
2156  *      drv->port should be NULL, and the per-port structures should be
2157  *      registered using uart_add_one_port after this call has succeeded.
2158  */
2159 int uart_register_driver(struct uart_driver *drv)
2160 {
2161         struct tty_driver *normal = NULL;
2162         int i, retval;
2163
2164         BUG_ON(drv->state);
2165
2166         /*
2167          * Maybe we should be using a slab cache for this, especially if
2168          * we have a large number of ports to handle.
2169          */
2170         drv->state = kmalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2171         retval = -ENOMEM;
2172         if (!drv->state)
2173                 goto out;
2174
2175         memset(drv->state, 0, sizeof(struct uart_state) * drv->nr);
2176
2177         normal  = alloc_tty_driver(drv->nr);
2178         if (!normal)
2179                 goto out;
2180
2181         drv->tty_driver = normal;
2182
2183         normal->owner           = drv->owner;
2184         normal->driver_name     = drv->driver_name;
2185         normal->name            = drv->dev_name;
2186         normal->major           = drv->major;
2187         normal->minor_start     = drv->minor;
2188         normal->type            = TTY_DRIVER_TYPE_SERIAL;
2189         normal->subtype         = SERIAL_TYPE_NORMAL;
2190         normal->init_termios    = tty_std_termios;
2191         normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2192         normal->flags           = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2193         normal->driver_state    = drv;
2194         tty_set_operations(normal, &uart_ops);
2195
2196         /*
2197          * Initialise the UART state(s).
2198          */
2199         for (i = 0; i < drv->nr; i++) {
2200                 struct uart_state *state = drv->state + i;
2201
2202                 state->close_delay     = 500;   /* .5 seconds */
2203                 state->closing_wait    = 30000; /* 30 seconds */
2204
2205                 mutex_init(&state->mutex);
2206         }
2207
2208         retval = tty_register_driver(normal);
2209  out:
2210         if (retval < 0) {
2211                 put_tty_driver(normal);
2212                 kfree(drv->state);
2213         }
2214         return retval;
2215 }
2216
2217 /**
2218  *      uart_unregister_driver - remove a driver from the uart core layer
2219  *      @drv: low level driver structure
2220  *
2221  *      Remove all references to a driver from the core driver.  The low
2222  *      level driver must have removed all its ports via the
2223  *      uart_remove_one_port() if it registered them with uart_add_one_port().
2224  *      (ie, drv->port == NULL)
2225  */
2226 void uart_unregister_driver(struct uart_driver *drv)
2227 {
2228         struct tty_driver *p = drv->tty_driver;
2229         tty_unregister_driver(p);
2230         put_tty_driver(p);
2231         kfree(drv->state);
2232         drv->tty_driver = NULL;
2233 }
2234
2235 struct tty_driver *uart_console_device(struct console *co, int *index)
2236 {
2237         struct uart_driver *p = co->data;
2238         *index = co->index;
2239         return p->tty_driver;
2240 }
2241
2242 /**
2243  *      uart_add_one_port - attach a driver-defined port structure
2244  *      @drv: pointer to the uart low level driver structure for this port
2245  *      @port: uart port structure to use for this port.
2246  *
2247  *      This allows the driver to register its own uart_port structure
2248  *      with the core driver.  The main purpose is to allow the low
2249  *      level uart drivers to expand uart_port, rather than having yet
2250  *      more levels of structures.
2251  */
2252 int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
2253 {
2254         struct uart_state *state;
2255         int ret = 0;
2256
2257         BUG_ON(in_interrupt());
2258
2259         if (port->line >= drv->nr)
2260                 return -EINVAL;
2261
2262         state = drv->state + port->line;
2263
2264         mutex_lock(&port_mutex);
2265         mutex_lock(&state->mutex);
2266         if (state->port) {
2267                 ret = -EINVAL;
2268                 goto out;
2269         }
2270
2271         state->port = port;
2272
2273         port->cons = drv->cons;
2274         port->info = state->info;
2275
2276         /*
2277          * If this port is a console, then the spinlock is already
2278          * initialised.
2279          */
2280         if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
2281                 spin_lock_init(&port->lock);
2282                 lockdep_set_class(&port->lock, &port_lock_key);
2283         }
2284
2285         uart_configure_port(drv, state, port);
2286
2287         /*
2288          * Register the port whether it's detected or not.  This allows
2289          * setserial to be used to alter this ports parameters.
2290          */
2291         tty_register_device(drv->tty_driver, port->line, port->dev);
2292
2293         /*
2294          * If this driver supports console, and it hasn't been
2295          * successfully registered yet, try to re-register it.
2296          * It may be that the port was not available.
2297          */
2298         if (port->type != PORT_UNKNOWN &&
2299             port->cons && !(port->cons->flags & CON_ENABLED))
2300                 register_console(port->cons);
2301
2302         /*
2303          * Ensure UPF_DEAD is not set.
2304          */
2305         port->flags &= ~UPF_DEAD;
2306
2307  out:
2308         mutex_unlock(&state->mutex);
2309         mutex_unlock(&port_mutex);
2310
2311         return ret;
2312 }
2313
2314 /**
2315  *      uart_remove_one_port - detach a driver defined port structure
2316  *      @drv: pointer to the uart low level driver structure for this port
2317  *      @port: uart port structure for this port
2318  *
2319  *      This unhooks (and hangs up) the specified port structure from the
2320  *      core driver.  No further calls will be made to the low-level code
2321  *      for this port.
2322  */
2323 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
2324 {
2325         struct uart_state *state = drv->state + port->line;
2326         struct uart_info *info;
2327
2328         BUG_ON(in_interrupt());
2329
2330         if (state->port != port)
2331                 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2332                         state->port, port);
2333
2334         mutex_lock(&port_mutex);
2335
2336         /*
2337          * Mark the port "dead" - this prevents any opens from
2338          * succeeding while we shut down the port.
2339          */
2340         mutex_lock(&state->mutex);
2341         port->flags |= UPF_DEAD;
2342         mutex_unlock(&state->mutex);
2343
2344         /*
2345          * Remove the devices from the tty layer
2346          */
2347         tty_unregister_device(drv->tty_driver, port->line);
2348
2349         info = state->info;
2350         if (info && info->tty)
2351                 tty_vhangup(info->tty);
2352
2353         /*
2354          * All users of this port should now be disconnected from
2355          * this driver, and the port shut down.  We should be the
2356          * only thread fiddling with this port from now on.
2357          */
2358         state->info = NULL;
2359
2360         /*
2361          * Free the port IO and memory resources, if any.
2362          */
2363         if (port->type != PORT_UNKNOWN)
2364                 port->ops->release_port(port);
2365
2366         /*
2367          * Indicate that there isn't a port here anymore.
2368          */
2369         port->type = PORT_UNKNOWN;
2370
2371         /*
2372          * Kill the tasklet, and free resources.
2373          */
2374         if (info) {
2375                 tasklet_kill(&info->tlet);
2376                 kfree(info);
2377         }
2378
2379         state->port = NULL;
2380         mutex_unlock(&port_mutex);
2381
2382         return 0;
2383 }
2384
2385 /*
2386  *      Are the two ports equivalent?
2387  */
2388 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2389 {
2390         if (port1->iotype != port2->iotype)
2391                 return 0;
2392
2393         switch (port1->iotype) {
2394         case UPIO_PORT:
2395                 return (port1->iobase == port2->iobase);
2396         case UPIO_HUB6:
2397                 return (port1->iobase == port2->iobase) &&
2398                        (port1->hub6   == port2->hub6);
2399         case UPIO_MEM:
2400         case UPIO_MEM32:
2401         case UPIO_AU:
2402         case UPIO_TSI:
2403                 return (port1->mapbase == port2->mapbase);
2404         }
2405         return 0;
2406 }
2407 EXPORT_SYMBOL(uart_match_port);
2408
2409 EXPORT_SYMBOL(uart_write_wakeup);
2410 EXPORT_SYMBOL(uart_register_driver);
2411 EXPORT_SYMBOL(uart_unregister_driver);
2412 EXPORT_SYMBOL(uart_suspend_port);
2413 EXPORT_SYMBOL(uart_resume_port);
2414 EXPORT_SYMBOL(uart_add_one_port);
2415 EXPORT_SYMBOL(uart_remove_one_port);
2416
2417 MODULE_DESCRIPTION("Serial driver core");
2418 MODULE_LICENSE("GPL");