serial: define FIXED_PORT flag for serial_core
[linux-2.6.git] / 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 ktermios *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 ktermios *termios,
342                    struct ktermios *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 ktermios *old_termios)
425 {
426         struct tty_struct *tty = state->info->tty;
427         struct uart_port *port = state->port;
428         struct ktermios *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  = !(port->flags & UPF_FIXED_PORT)
676                 && new_serial.irq != port->irq;
677
678         /*
679          * Since changing the 'type' of the port changes its resource
680          * allocations, we should treat type changes the same as
681          * IO port changes.
682          */
683         change_port = !(port->flags & UPF_FIXED_PORT)
684                 && (new_port != port->iobase ||
685                     (unsigned long)new_serial.iomem_base != port->mapbase ||
686                     new_serial.hub6 != port->hub6 ||
687                     new_serial.io_type != port->iotype ||
688                     new_serial.iomem_reg_shift != port->regshift ||
689                     new_serial.type != port->type);
690
691         old_flags = port->flags;
692         new_flags = new_serial.flags;
693         old_custom_divisor = port->custom_divisor;
694
695         if (!capable(CAP_SYS_ADMIN)) {
696                 retval = -EPERM;
697                 if (change_irq || change_port ||
698                     (new_serial.baud_base != port->uartclk / 16) ||
699                     (close_delay != state->close_delay) ||
700                     (closing_wait != state->closing_wait) ||
701                     (new_serial.xmit_fifo_size &&
702                      new_serial.xmit_fifo_size != port->fifosize) ||
703                     (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
704                         goto exit;
705                 port->flags = ((port->flags & ~UPF_USR_MASK) |
706                                (new_flags & UPF_USR_MASK));
707                 port->custom_divisor = new_serial.custom_divisor;
708                 goto check_and_exit;
709         }
710
711         /*
712          * Ask the low level driver to verify the settings.
713          */
714         if (port->ops->verify_port)
715                 retval = port->ops->verify_port(port, &new_serial);
716
717         if ((new_serial.irq >= NR_IRQS) || (new_serial.irq < 0) ||
718             (new_serial.baud_base < 9600))
719                 retval = -EINVAL;
720
721         if (retval)
722                 goto exit;
723
724         if (change_port || change_irq) {
725                 retval = -EBUSY;
726
727                 /*
728                  * Make sure that we are the sole user of this port.
729                  */
730                 if (uart_users(state) > 1)
731                         goto exit;
732
733                 /*
734                  * We need to shutdown the serial port at the old
735                  * port/type/irq combination.
736                  */
737                 uart_shutdown(state);
738         }
739
740         if (change_port) {
741                 unsigned long old_iobase, old_mapbase;
742                 unsigned int old_type, old_iotype, old_hub6, old_shift;
743
744                 old_iobase = port->iobase;
745                 old_mapbase = port->mapbase;
746                 old_type = port->type;
747                 old_hub6 = port->hub6;
748                 old_iotype = port->iotype;
749                 old_shift = port->regshift;
750
751                 /*
752                  * Free and release old regions
753                  */
754                 if (old_type != PORT_UNKNOWN)
755                         port->ops->release_port(port);
756
757                 port->iobase = new_port;
758                 port->type = new_serial.type;
759                 port->hub6 = new_serial.hub6;
760                 port->iotype = new_serial.io_type;
761                 port->regshift = new_serial.iomem_reg_shift;
762                 port->mapbase = (unsigned long)new_serial.iomem_base;
763
764                 /*
765                  * Claim and map the new regions
766                  */
767                 if (port->type != PORT_UNKNOWN) {
768                         retval = port->ops->request_port(port);
769                 } else {
770                         /* Always success - Jean II */
771                         retval = 0;
772                 }
773
774                 /*
775                  * If we fail to request resources for the
776                  * new port, try to restore the old settings.
777                  */
778                 if (retval && old_type != PORT_UNKNOWN) {
779                         port->iobase = old_iobase;
780                         port->type = old_type;
781                         port->hub6 = old_hub6;
782                         port->iotype = old_iotype;
783                         port->regshift = old_shift;
784                         port->mapbase = old_mapbase;
785                         retval = port->ops->request_port(port);
786                         /*
787                          * If we failed to restore the old settings,
788                          * we fail like this.
789                          */
790                         if (retval)
791                                 port->type = PORT_UNKNOWN;
792
793                         /*
794                          * We failed anyway.
795                          */
796                         retval = -EBUSY;
797                         goto exit;  // Added to return the correct error -Ram Gupta
798                 }
799         }
800
801         if (change_irq)
802                 port->irq      = new_serial.irq;
803         if (!(port->flags & UPF_FIXED_PORT))
804                 port->uartclk  = new_serial.baud_base * 16;
805         port->flags            = (port->flags & ~UPF_CHANGE_MASK) |
806                                  (new_flags & UPF_CHANGE_MASK);
807         port->custom_divisor   = new_serial.custom_divisor;
808         state->close_delay     = close_delay;
809         state->closing_wait    = closing_wait;
810         if (new_serial.xmit_fifo_size)
811                 port->fifosize = new_serial.xmit_fifo_size;
812         if (state->info->tty)
813                 state->info->tty->low_latency =
814                         (port->flags & UPF_LOW_LATENCY) ? 1 : 0;
815
816  check_and_exit:
817         retval = 0;
818         if (port->type == PORT_UNKNOWN)
819                 goto exit;
820         if (state->info->flags & UIF_INITIALIZED) {
821                 if (((old_flags ^ port->flags) & UPF_SPD_MASK) ||
822                     old_custom_divisor != port->custom_divisor) {
823                         /*
824                          * If they're setting up a custom divisor or speed,
825                          * instead of clearing it, then bitch about it. No
826                          * need to rate-limit; it's CAP_SYS_ADMIN only.
827                          */
828                         if (port->flags & UPF_SPD_MASK) {
829                                 char buf[64];
830                                 printk(KERN_NOTICE
831                                        "%s sets custom speed on %s. This "
832                                        "is deprecated.\n", current->comm,
833                                        tty_name(state->info->tty, buf));
834                         }
835                         uart_change_speed(state, NULL);
836                 }
837         } else
838                 retval = uart_startup(state, 1);
839  exit:
840         mutex_unlock(&state->mutex);
841         return retval;
842 }
843
844
845 /*
846  * uart_get_lsr_info - get line status register info.
847  * Note: uart_ioctl protects us against hangups.
848  */
849 static int uart_get_lsr_info(struct uart_state *state,
850                              unsigned int __user *value)
851 {
852         struct uart_port *port = state->port;
853         unsigned int result;
854
855         result = port->ops->tx_empty(port);
856
857         /*
858          * If we're about to load something into the transmit
859          * register, we'll pretend the transmitter isn't empty to
860          * avoid a race condition (depending on when the transmit
861          * interrupt happens).
862          */
863         if (port->x_char ||
864             ((uart_circ_chars_pending(&state->info->xmit) > 0) &&
865              !state->info->tty->stopped && !state->info->tty->hw_stopped))
866                 result &= ~TIOCSER_TEMT;
867         
868         return put_user(result, value);
869 }
870
871 static int uart_tiocmget(struct tty_struct *tty, struct file *file)
872 {
873         struct uart_state *state = tty->driver_data;
874         struct uart_port *port = state->port;
875         int result = -EIO;
876
877         mutex_lock(&state->mutex);
878         if ((!file || !tty_hung_up_p(file)) &&
879             !(tty->flags & (1 << TTY_IO_ERROR))) {
880                 result = port->mctrl;
881
882                 spin_lock_irq(&port->lock);
883                 result |= port->ops->get_mctrl(port);
884                 spin_unlock_irq(&port->lock);
885         }
886         mutex_unlock(&state->mutex);
887
888         return result;
889 }
890
891 static int
892 uart_tiocmset(struct tty_struct *tty, struct file *file,
893               unsigned int set, unsigned int clear)
894 {
895         struct uart_state *state = tty->driver_data;
896         struct uart_port *port = state->port;
897         int ret = -EIO;
898
899         mutex_lock(&state->mutex);
900         if ((!file || !tty_hung_up_p(file)) &&
901             !(tty->flags & (1 << TTY_IO_ERROR))) {
902                 uart_update_mctrl(port, set, clear);
903                 ret = 0;
904         }
905         mutex_unlock(&state->mutex);
906         return ret;
907 }
908
909 static void uart_break_ctl(struct tty_struct *tty, int break_state)
910 {
911         struct uart_state *state = tty->driver_data;
912         struct uart_port *port = state->port;
913
914         BUG_ON(!kernel_locked());
915
916         mutex_lock(&state->mutex);
917
918         if (port->type != PORT_UNKNOWN)
919                 port->ops->break_ctl(port, break_state);
920
921         mutex_unlock(&state->mutex);
922 }
923
924 static int uart_do_autoconfig(struct uart_state *state)
925 {
926         struct uart_port *port = state->port;
927         int flags, ret;
928
929         if (!capable(CAP_SYS_ADMIN))
930                 return -EPERM;
931
932         /*
933          * Take the per-port semaphore.  This prevents count from
934          * changing, and hence any extra opens of the port while
935          * we're auto-configuring.
936          */
937         if (mutex_lock_interruptible(&state->mutex))
938                 return -ERESTARTSYS;
939
940         ret = -EBUSY;
941         if (uart_users(state) == 1) {
942                 uart_shutdown(state);
943
944                 /*
945                  * If we already have a port type configured,
946                  * we must release its resources.
947                  */
948                 if (port->type != PORT_UNKNOWN)
949                         port->ops->release_port(port);
950
951                 flags = UART_CONFIG_TYPE;
952                 if (port->flags & UPF_AUTO_IRQ)
953                         flags |= UART_CONFIG_IRQ;
954
955                 /*
956                  * This will claim the ports resources if
957                  * a port is found.
958                  */
959                 port->ops->config_port(port, flags);
960
961                 ret = uart_startup(state, 1);
962         }
963         mutex_unlock(&state->mutex);
964         return ret;
965 }
966
967 /*
968  * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
969  * - mask passed in arg for lines of interest
970  *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
971  * Caller should use TIOCGICOUNT to see which one it was
972  */
973 static int
974 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
975 {
976         struct uart_port *port = state->port;
977         DECLARE_WAITQUEUE(wait, current);
978         struct uart_icount cprev, cnow;
979         int ret;
980
981         /*
982          * note the counters on entry
983          */
984         spin_lock_irq(&port->lock);
985         memcpy(&cprev, &port->icount, sizeof(struct uart_icount));
986
987         /*
988          * Force modem status interrupts on
989          */
990         port->ops->enable_ms(port);
991         spin_unlock_irq(&port->lock);
992
993         add_wait_queue(&state->info->delta_msr_wait, &wait);
994         for (;;) {
995                 spin_lock_irq(&port->lock);
996                 memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
997                 spin_unlock_irq(&port->lock);
998
999                 set_current_state(TASK_INTERRUPTIBLE);
1000
1001                 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1002                     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1003                     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1004                     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1005                         ret = 0;
1006                         break;
1007                 }
1008
1009                 schedule();
1010
1011                 /* see if a signal did it */
1012                 if (signal_pending(current)) {
1013                         ret = -ERESTARTSYS;
1014                         break;
1015                 }
1016
1017                 cprev = cnow;
1018         }
1019
1020         current->state = TASK_RUNNING;
1021         remove_wait_queue(&state->info->delta_msr_wait, &wait);
1022
1023         return ret;
1024 }
1025
1026 /*
1027  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1028  * Return: write counters to the user passed counter struct
1029  * NB: both 1->0 and 0->1 transitions are counted except for
1030  *     RI where only 0->1 is counted.
1031  */
1032 static int uart_get_count(struct uart_state *state,
1033                           struct serial_icounter_struct __user *icnt)
1034 {
1035         struct serial_icounter_struct icount;
1036         struct uart_icount cnow;
1037         struct uart_port *port = state->port;
1038
1039         spin_lock_irq(&port->lock);
1040         memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
1041         spin_unlock_irq(&port->lock);
1042
1043         icount.cts         = cnow.cts;
1044         icount.dsr         = cnow.dsr;
1045         icount.rng         = cnow.rng;
1046         icount.dcd         = cnow.dcd;
1047         icount.rx          = cnow.rx;
1048         icount.tx          = cnow.tx;
1049         icount.frame       = cnow.frame;
1050         icount.overrun     = cnow.overrun;
1051         icount.parity      = cnow.parity;
1052         icount.brk         = cnow.brk;
1053         icount.buf_overrun = cnow.buf_overrun;
1054
1055         return copy_to_user(icnt, &icount, sizeof(icount)) ? -EFAULT : 0;
1056 }
1057
1058 /*
1059  * Called via sys_ioctl under the BKL.  We can use spin_lock_irq() here.
1060  */
1061 static int
1062 uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
1063            unsigned long arg)
1064 {
1065         struct uart_state *state = tty->driver_data;
1066         void __user *uarg = (void __user *)arg;
1067         int ret = -ENOIOCTLCMD;
1068
1069         BUG_ON(!kernel_locked());
1070
1071         /*
1072          * These ioctls don't rely on the hardware to be present.
1073          */
1074         switch (cmd) {
1075         case TIOCGSERIAL:
1076                 ret = uart_get_info(state, uarg);
1077                 break;
1078
1079         case TIOCSSERIAL:
1080                 ret = uart_set_info(state, uarg);
1081                 break;
1082
1083         case TIOCSERCONFIG:
1084                 ret = uart_do_autoconfig(state);
1085                 break;
1086
1087         case TIOCSERGWILD: /* obsolete */
1088         case TIOCSERSWILD: /* obsolete */
1089                 ret = 0;
1090                 break;
1091         }
1092
1093         if (ret != -ENOIOCTLCMD)
1094                 goto out;
1095
1096         if (tty->flags & (1 << TTY_IO_ERROR)) {
1097                 ret = -EIO;
1098                 goto out;
1099         }
1100
1101         /*
1102          * The following should only be used when hardware is present.
1103          */
1104         switch (cmd) {
1105         case TIOCMIWAIT:
1106                 ret = uart_wait_modem_status(state, arg);
1107                 break;
1108
1109         case TIOCGICOUNT:
1110                 ret = uart_get_count(state, uarg);
1111                 break;
1112         }
1113
1114         if (ret != -ENOIOCTLCMD)
1115                 goto out;
1116
1117         mutex_lock(&state->mutex);
1118
1119         if (tty_hung_up_p(filp)) {
1120                 ret = -EIO;
1121                 goto out_up;
1122         }
1123
1124         /*
1125          * All these rely on hardware being present and need to be
1126          * protected against the tty being hung up.
1127          */
1128         switch (cmd) {
1129         case TIOCSERGETLSR: /* Get line status register */
1130                 ret = uart_get_lsr_info(state, uarg);
1131                 break;
1132
1133         default: {
1134                 struct uart_port *port = state->port;
1135                 if (port->ops->ioctl)
1136                         ret = port->ops->ioctl(port, cmd, arg);
1137                 break;
1138         }
1139         }
1140  out_up:
1141         mutex_unlock(&state->mutex);
1142  out:
1143         return ret;
1144 }
1145
1146 static void uart_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
1147 {
1148         struct uart_state *state = tty->driver_data;
1149         unsigned long flags;
1150         unsigned int cflag = tty->termios->c_cflag;
1151
1152         BUG_ON(!kernel_locked());
1153
1154         /*
1155          * These are the bits that are used to setup various
1156          * flags in the low level driver.
1157          */
1158 #define RELEVANT_IFLAG(iflag)   ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1159
1160         if ((cflag ^ old_termios->c_cflag) == 0 &&
1161             RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0)
1162                 return;
1163
1164         uart_change_speed(state, old_termios);
1165
1166         /* Handle transition to B0 status */
1167         if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1168                 uart_clear_mctrl(state->port, TIOCM_RTS | TIOCM_DTR);
1169
1170         /* Handle transition away from B0 status */
1171         if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1172                 unsigned int mask = TIOCM_DTR;
1173                 if (!(cflag & CRTSCTS) ||
1174                     !test_bit(TTY_THROTTLED, &tty->flags))
1175                         mask |= TIOCM_RTS;
1176                 uart_set_mctrl(state->port, mask);
1177         }
1178
1179         /* Handle turning off CRTSCTS */
1180         if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1181                 spin_lock_irqsave(&state->port->lock, flags);
1182                 tty->hw_stopped = 0;
1183                 __uart_start(tty);
1184                 spin_unlock_irqrestore(&state->port->lock, flags);
1185         }
1186
1187         /* Handle turning on CRTSCTS */
1188         if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1189                 spin_lock_irqsave(&state->port->lock, flags);
1190                 if (!(state->port->ops->get_mctrl(state->port) & TIOCM_CTS)) {
1191                         tty->hw_stopped = 1;
1192                         state->port->ops->stop_tx(state->port);
1193                 }
1194                 spin_unlock_irqrestore(&state->port->lock, flags);
1195         }
1196
1197 #if 0
1198         /*
1199          * No need to wake up processes in open wait, since they
1200          * sample the CLOCAL flag once, and don't recheck it.
1201          * XXX  It's not clear whether the current behavior is correct
1202          * or not.  Hence, this may change.....
1203          */
1204         if (!(old_termios->c_cflag & CLOCAL) &&
1205             (tty->termios->c_cflag & CLOCAL))
1206                 wake_up_interruptible(&state->info->open_wait);
1207 #endif
1208 }
1209
1210 /*
1211  * In 2.4.5, calls to this will be serialized via the BKL in
1212  *  linux/drivers/char/tty_io.c:tty_release()
1213  *  linux/drivers/char/tty_io.c:do_tty_handup()
1214  */
1215 static void uart_close(struct tty_struct *tty, struct file *filp)
1216 {
1217         struct uart_state *state = tty->driver_data;
1218         struct uart_port *port;
1219         
1220         BUG_ON(!kernel_locked());
1221
1222         if (!state || !state->port)
1223                 return;
1224
1225         port = state->port;
1226
1227         DPRINTK("uart_close(%d) called\n", port->line);
1228
1229         mutex_lock(&state->mutex);
1230
1231         if (tty_hung_up_p(filp))
1232                 goto done;
1233
1234         if ((tty->count == 1) && (state->count != 1)) {
1235                 /*
1236                  * Uh, oh.  tty->count is 1, which means that the tty
1237                  * structure will be freed.  state->count should always
1238                  * be one in these conditions.  If it's greater than
1239                  * one, we've got real problems, since it means the
1240                  * serial port won't be shutdown.
1241                  */
1242                 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1243                        "state->count is %d\n", state->count);
1244                 state->count = 1;
1245         }
1246         if (--state->count < 0) {
1247                 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1248                        tty->name, state->count);
1249                 state->count = 0;
1250         }
1251         if (state->count)
1252                 goto done;
1253
1254         /*
1255          * Now we wait for the transmit buffer to clear; and we notify
1256          * the line discipline to only process XON/XOFF characters by
1257          * setting tty->closing.
1258          */
1259         tty->closing = 1;
1260
1261         if (state->closing_wait != USF_CLOSING_WAIT_NONE)
1262                 tty_wait_until_sent(tty, msecs_to_jiffies(state->closing_wait));
1263
1264         /*
1265          * At this point, we stop accepting input.  To do this, we
1266          * disable the receive line status interrupts.
1267          */
1268         if (state->info->flags & UIF_INITIALIZED) {
1269                 unsigned long flags;
1270                 spin_lock_irqsave(&port->lock, flags);
1271                 port->ops->stop_rx(port);
1272                 spin_unlock_irqrestore(&port->lock, flags);
1273                 /*
1274                  * Before we drop DTR, make sure the UART transmitter
1275                  * has completely drained; this is especially
1276                  * important if there is a transmit FIFO!
1277                  */
1278                 uart_wait_until_sent(tty, port->timeout);
1279         }
1280
1281         uart_shutdown(state);
1282         uart_flush_buffer(tty);
1283
1284         tty_ldisc_flush(tty);   
1285         
1286         tty->closing = 0;
1287         state->info->tty = NULL;
1288
1289         if (state->info->blocked_open) {
1290                 if (state->close_delay)
1291                         msleep_interruptible(state->close_delay);
1292         } else if (!uart_console(port)) {
1293                 uart_change_pm(state, 3);
1294         }
1295
1296         /*
1297          * Wake up anyone trying to open this port.
1298          */
1299         state->info->flags &= ~UIF_NORMAL_ACTIVE;
1300         wake_up_interruptible(&state->info->open_wait);
1301
1302  done:
1303         mutex_unlock(&state->mutex);
1304 }
1305
1306 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1307 {
1308         struct uart_state *state = tty->driver_data;
1309         struct uart_port *port = state->port;
1310         unsigned long char_time, expire;
1311
1312         BUG_ON(!kernel_locked());
1313
1314         if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1315                 return;
1316
1317         /*
1318          * Set the check interval to be 1/5 of the estimated time to
1319          * send a single character, and make it at least 1.  The check
1320          * interval should also be less than the timeout.
1321          *
1322          * Note: we have to use pretty tight timings here to satisfy
1323          * the NIST-PCTS.
1324          */
1325         char_time = (port->timeout - HZ/50) / port->fifosize;
1326         char_time = char_time / 5;
1327         if (char_time == 0)
1328                 char_time = 1;
1329         if (timeout && timeout < char_time)
1330                 char_time = timeout;
1331
1332         /*
1333          * If the transmitter hasn't cleared in twice the approximate
1334          * amount of time to send the entire FIFO, it probably won't
1335          * ever clear.  This assumes the UART isn't doing flow
1336          * control, which is currently the case.  Hence, if it ever
1337          * takes longer than port->timeout, this is probably due to a
1338          * UART bug of some kind.  So, we clamp the timeout parameter at
1339          * 2*port->timeout.
1340          */
1341         if (timeout == 0 || timeout > 2 * port->timeout)
1342                 timeout = 2 * port->timeout;
1343
1344         expire = jiffies + timeout;
1345
1346         DPRINTK("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1347                 port->line, jiffies, expire);
1348
1349         /*
1350          * Check whether the transmitter is empty every 'char_time'.
1351          * 'timeout' / 'expire' give us the maximum amount of time
1352          * we wait.
1353          */
1354         while (!port->ops->tx_empty(port)) {
1355                 msleep_interruptible(jiffies_to_msecs(char_time));
1356                 if (signal_pending(current))
1357                         break;
1358                 if (time_after(jiffies, expire))
1359                         break;
1360         }
1361         set_current_state(TASK_RUNNING); /* might not be needed */
1362 }
1363
1364 /*
1365  * This is called with the BKL held in
1366  *  linux/drivers/char/tty_io.c:do_tty_hangup()
1367  * We're called from the eventd thread, so we can sleep for
1368  * a _short_ time only.
1369  */
1370 static void uart_hangup(struct tty_struct *tty)
1371 {
1372         struct uart_state *state = tty->driver_data;
1373
1374         BUG_ON(!kernel_locked());
1375         DPRINTK("uart_hangup(%d)\n", state->port->line);
1376
1377         mutex_lock(&state->mutex);
1378         if (state->info && state->info->flags & UIF_NORMAL_ACTIVE) {
1379                 uart_flush_buffer(tty);
1380                 uart_shutdown(state);
1381                 state->count = 0;
1382                 state->info->flags &= ~UIF_NORMAL_ACTIVE;
1383                 state->info->tty = NULL;
1384                 wake_up_interruptible(&state->info->open_wait);
1385                 wake_up_interruptible(&state->info->delta_msr_wait);
1386         }
1387         mutex_unlock(&state->mutex);
1388 }
1389
1390 /*
1391  * Copy across the serial console cflag setting into the termios settings
1392  * for the initial open of the port.  This allows continuity between the
1393  * kernel settings, and the settings init adopts when it opens the port
1394  * for the first time.
1395  */
1396 static void uart_update_termios(struct uart_state *state)
1397 {
1398         struct tty_struct *tty = state->info->tty;
1399         struct uart_port *port = state->port;
1400
1401         if (uart_console(port) && port->cons->cflag) {
1402                 tty->termios->c_cflag = port->cons->cflag;
1403                 port->cons->cflag = 0;
1404         }
1405
1406         /*
1407          * If the device failed to grab its irq resources,
1408          * or some other error occurred, don't try to talk
1409          * to the port hardware.
1410          */
1411         if (!(tty->flags & (1 << TTY_IO_ERROR))) {
1412                 /*
1413                  * Make termios settings take effect.
1414                  */
1415                 uart_change_speed(state, NULL);
1416
1417                 /*
1418                  * And finally enable the RTS and DTR signals.
1419                  */
1420                 if (tty->termios->c_cflag & CBAUD)
1421                         uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
1422         }
1423 }
1424
1425 /*
1426  * Block the open until the port is ready.  We must be called with
1427  * the per-port semaphore held.
1428  */
1429 static int
1430 uart_block_til_ready(struct file *filp, struct uart_state *state)
1431 {
1432         DECLARE_WAITQUEUE(wait, current);
1433         struct uart_info *info = state->info;
1434         struct uart_port *port = state->port;
1435         unsigned int mctrl;
1436
1437         info->blocked_open++;
1438         state->count--;
1439
1440         add_wait_queue(&info->open_wait, &wait);
1441         while (1) {
1442                 set_current_state(TASK_INTERRUPTIBLE);
1443
1444                 /*
1445                  * If we have been hung up, tell userspace/restart open.
1446                  */
1447                 if (tty_hung_up_p(filp) || info->tty == NULL)
1448                         break;
1449
1450                 /*
1451                  * If the port has been closed, tell userspace/restart open.
1452                  */
1453                 if (!(info->flags & UIF_INITIALIZED))
1454                         break;
1455
1456                 /*
1457                  * If non-blocking mode is set, or CLOCAL mode is set,
1458                  * we don't want to wait for the modem status lines to
1459                  * indicate that the port is ready.
1460                  *
1461                  * Also, if the port is not enabled/configured, we want
1462                  * to allow the open to succeed here.  Note that we will
1463                  * have set TTY_IO_ERROR for a non-existant port.
1464                  */
1465                 if ((filp->f_flags & O_NONBLOCK) ||
1466                     (info->tty->termios->c_cflag & CLOCAL) ||
1467                     (info->tty->flags & (1 << TTY_IO_ERROR))) {
1468                         break;
1469                 }
1470
1471                 /*
1472                  * Set DTR to allow modem to know we're waiting.  Do
1473                  * not set RTS here - we want to make sure we catch
1474                  * the data from the modem.
1475                  */
1476                 if (info->tty->termios->c_cflag & CBAUD)
1477                         uart_set_mctrl(port, TIOCM_DTR);
1478
1479                 /*
1480                  * and wait for the carrier to indicate that the
1481                  * modem is ready for us.
1482                  */
1483                 spin_lock_irq(&port->lock);
1484                 port->ops->enable_ms(port);
1485                 mctrl = port->ops->get_mctrl(port);
1486                 spin_unlock_irq(&port->lock);
1487                 if (mctrl & TIOCM_CAR)
1488                         break;
1489
1490                 mutex_unlock(&state->mutex);
1491                 schedule();
1492                 mutex_lock(&state->mutex);
1493
1494                 if (signal_pending(current))
1495                         break;
1496         }
1497         set_current_state(TASK_RUNNING);
1498         remove_wait_queue(&info->open_wait, &wait);
1499
1500         state->count++;
1501         info->blocked_open--;
1502
1503         if (signal_pending(current))
1504                 return -ERESTARTSYS;
1505
1506         if (!info->tty || tty_hung_up_p(filp))
1507                 return -EAGAIN;
1508
1509         return 0;
1510 }
1511
1512 static struct uart_state *uart_get(struct uart_driver *drv, int line)
1513 {
1514         struct uart_state *state;
1515         int ret = 0;
1516
1517         state = drv->state + line;
1518         if (mutex_lock_interruptible(&state->mutex)) {
1519                 ret = -ERESTARTSYS;
1520                 goto err;
1521         }
1522
1523         state->count++;
1524         if (!state->port || state->port->flags & UPF_DEAD) {
1525                 ret = -ENXIO;
1526                 goto err_unlock;
1527         }
1528
1529         if (!state->info) {
1530                 state->info = kzalloc(sizeof(struct uart_info), GFP_KERNEL);
1531                 if (state->info) {
1532                         init_waitqueue_head(&state->info->open_wait);
1533                         init_waitqueue_head(&state->info->delta_msr_wait);
1534
1535                         /*
1536                          * Link the info into the other structures.
1537                          */
1538                         state->port->info = state->info;
1539
1540                         tasklet_init(&state->info->tlet, uart_tasklet_action,
1541                                      (unsigned long)state);
1542                 } else {
1543                         ret = -ENOMEM;
1544                         goto err_unlock;
1545                 }
1546         }
1547         return state;
1548
1549  err_unlock:
1550         state->count--;
1551         mutex_unlock(&state->mutex);
1552  err:
1553         return ERR_PTR(ret);
1554 }
1555
1556 /*
1557  * In 2.4.5, calls to uart_open are serialised by the BKL in
1558  *   linux/fs/devices.c:chrdev_open()
1559  * Note that if this fails, then uart_close() _will_ be called.
1560  *
1561  * In time, we want to scrap the "opening nonpresent ports"
1562  * behaviour and implement an alternative way for setserial
1563  * to set base addresses/ports/types.  This will allow us to
1564  * get rid of a certain amount of extra tests.
1565  */
1566 static int uart_open(struct tty_struct *tty, struct file *filp)
1567 {
1568         struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1569         struct uart_state *state;
1570         int retval, line = tty->index;
1571
1572         BUG_ON(!kernel_locked());
1573         DPRINTK("uart_open(%d) called\n", line);
1574
1575         /*
1576          * tty->driver->num won't change, so we won't fail here with
1577          * tty->driver_data set to something non-NULL (and therefore
1578          * we won't get caught by uart_close()).
1579          */
1580         retval = -ENODEV;
1581         if (line >= tty->driver->num)
1582                 goto fail;
1583
1584         /*
1585          * We take the semaphore inside uart_get to guarantee that we won't
1586          * be re-entered while allocating the info structure, or while we
1587          * request any IRQs that the driver may need.  This also has the nice
1588          * side-effect that it delays the action of uart_hangup, so we can
1589          * guarantee that info->tty will always contain something reasonable.
1590          */
1591         state = uart_get(drv, line);
1592         if (IS_ERR(state)) {
1593                 retval = PTR_ERR(state);
1594                 goto fail;
1595         }
1596
1597         /*
1598          * Once we set tty->driver_data here, we are guaranteed that
1599          * uart_close() will decrement the driver module use count.
1600          * Any failures from here onwards should not touch the count.
1601          */
1602         tty->driver_data = state;
1603         tty->low_latency = (state->port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1604         tty->alt_speed = 0;
1605         state->info->tty = tty;
1606
1607         /*
1608          * If the port is in the middle of closing, bail out now.
1609          */
1610         if (tty_hung_up_p(filp)) {
1611                 retval = -EAGAIN;
1612                 state->count--;
1613                 mutex_unlock(&state->mutex);
1614                 goto fail;
1615         }
1616
1617         /*
1618          * Make sure the device is in D0 state.
1619          */
1620         if (state->count == 1)
1621                 uart_change_pm(state, 0);
1622
1623         /*
1624          * Start up the serial port.
1625          */
1626         retval = uart_startup(state, 0);
1627
1628         /*
1629          * If we succeeded, wait until the port is ready.
1630          */
1631         if (retval == 0)
1632                 retval = uart_block_til_ready(filp, state);
1633         mutex_unlock(&state->mutex);
1634
1635         /*
1636          * If this is the first open to succeed, adjust things to suit.
1637          */
1638         if (retval == 0 && !(state->info->flags & UIF_NORMAL_ACTIVE)) {
1639                 state->info->flags |= UIF_NORMAL_ACTIVE;
1640
1641                 uart_update_termios(state);
1642         }
1643
1644  fail:
1645         return retval;
1646 }
1647
1648 static const char *uart_type(struct uart_port *port)
1649 {
1650         const char *str = NULL;
1651
1652         if (port->ops->type)
1653                 str = port->ops->type(port);
1654
1655         if (!str)
1656                 str = "unknown";
1657
1658         return str;
1659 }
1660
1661 #ifdef CONFIG_PROC_FS
1662
1663 static int uart_line_info(char *buf, struct uart_driver *drv, int i)
1664 {
1665         struct uart_state *state = drv->state + i;
1666         int pm_state;
1667         struct uart_port *port = state->port;
1668         char stat_buf[32];
1669         unsigned int status;
1670         int mmio, ret;
1671
1672         if (!port)
1673                 return 0;
1674
1675         mmio = port->iotype >= UPIO_MEM;
1676         ret = sprintf(buf, "%d: uart:%s %s%08lX irq:%d",
1677                         port->line, uart_type(port),
1678                         mmio ? "mmio:0x" : "port:",
1679                         mmio ? port->mapbase : (unsigned long) port->iobase,
1680                         port->irq);
1681
1682         if (port->type == PORT_UNKNOWN) {
1683                 strcat(buf, "\n");
1684                 return ret + 1;
1685         }
1686
1687         if(capable(CAP_SYS_ADMIN))
1688         {
1689                 mutex_lock(&state->mutex);
1690                 pm_state = state->pm_state;
1691                 if (pm_state)
1692                         uart_change_pm(state, 0);
1693                 spin_lock_irq(&port->lock);
1694                 status = port->ops->get_mctrl(port);
1695                 spin_unlock_irq(&port->lock);
1696                 if (pm_state)
1697                         uart_change_pm(state, pm_state);
1698                 mutex_unlock(&state->mutex);
1699
1700                 ret += sprintf(buf + ret, " tx:%d rx:%d",
1701                                 port->icount.tx, port->icount.rx);
1702                 if (port->icount.frame)
1703                         ret += sprintf(buf + ret, " fe:%d",
1704                                 port->icount.frame);
1705                 if (port->icount.parity)
1706                         ret += sprintf(buf + ret, " pe:%d",
1707                                 port->icount.parity);
1708                 if (port->icount.brk)
1709                         ret += sprintf(buf + ret, " brk:%d",
1710                                 port->icount.brk);
1711                 if (port->icount.overrun)
1712                         ret += sprintf(buf + ret, " oe:%d",
1713                                 port->icount.overrun);
1714         
1715 #define INFOBIT(bit,str) \
1716         if (port->mctrl & (bit)) \
1717                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1718                         strlen(stat_buf) - 2)
1719 #define STATBIT(bit,str) \
1720         if (status & (bit)) \
1721                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1722                        strlen(stat_buf) - 2)
1723
1724                 stat_buf[0] = '\0';
1725                 stat_buf[1] = '\0';
1726                 INFOBIT(TIOCM_RTS, "|RTS");
1727                 STATBIT(TIOCM_CTS, "|CTS");
1728                 INFOBIT(TIOCM_DTR, "|DTR");
1729                 STATBIT(TIOCM_DSR, "|DSR");
1730                 STATBIT(TIOCM_CAR, "|CD");
1731                 STATBIT(TIOCM_RNG, "|RI");
1732                 if (stat_buf[0])
1733                         stat_buf[0] = ' ';
1734                 strcat(stat_buf, "\n");
1735         
1736                 ret += sprintf(buf + ret, stat_buf);
1737         } else {
1738                 strcat(buf, "\n");
1739                 ret++;
1740         }
1741 #undef STATBIT
1742 #undef INFOBIT
1743         return ret;
1744 }
1745
1746 static int uart_read_proc(char *page, char **start, off_t off,
1747                           int count, int *eof, void *data)
1748 {
1749         struct tty_driver *ttydrv = data;
1750         struct uart_driver *drv = ttydrv->driver_state;
1751         int i, len = 0, l;
1752         off_t begin = 0;
1753
1754         len += sprintf(page, "serinfo:1.0 driver%s%s revision:%s\n",
1755                         "", "", "");
1756         for (i = 0; i < drv->nr && len < PAGE_SIZE - 96; i++) {
1757                 l = uart_line_info(page + len, drv, i);
1758                 len += l;
1759                 if (len + begin > off + count)
1760                         goto done;
1761                 if (len + begin < off) {
1762                         begin += len;
1763                         len = 0;
1764                 }
1765         }
1766         *eof = 1;
1767  done:
1768         if (off >= len + begin)
1769                 return 0;
1770         *start = page + (off - begin);
1771         return (count < begin + len - off) ? count : (begin + len - off);
1772 }
1773 #endif
1774
1775 #ifdef CONFIG_SERIAL_CORE_CONSOLE
1776 /*
1777  *      uart_console_write - write a console message to a serial port
1778  *      @port: the port to write the message
1779  *      @s: array of characters
1780  *      @count: number of characters in string to write
1781  *      @write: function to write character to port
1782  */
1783 void uart_console_write(struct uart_port *port, const char *s,
1784                         unsigned int count,
1785                         void (*putchar)(struct uart_port *, int))
1786 {
1787         unsigned int i;
1788
1789         for (i = 0; i < count; i++, s++) {
1790                 if (*s == '\n')
1791                         putchar(port, '\r');
1792                 putchar(port, *s);
1793         }
1794 }
1795 EXPORT_SYMBOL_GPL(uart_console_write);
1796
1797 /*
1798  *      Check whether an invalid uart number has been specified, and
1799  *      if so, search for the first available port that does have
1800  *      console support.
1801  */
1802 struct uart_port * __init
1803 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1804 {
1805         int idx = co->index;
1806
1807         if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1808                                      ports[idx].membase == NULL))
1809                 for (idx = 0; idx < nr; idx++)
1810                         if (ports[idx].iobase != 0 ||
1811                             ports[idx].membase != NULL)
1812                                 break;
1813
1814         co->index = idx;
1815
1816         return ports + idx;
1817 }
1818
1819 /**
1820  *      uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1821  *      @options: pointer to option string
1822  *      @baud: pointer to an 'int' variable for the baud rate.
1823  *      @parity: pointer to an 'int' variable for the parity.
1824  *      @bits: pointer to an 'int' variable for the number of data bits.
1825  *      @flow: pointer to an 'int' variable for the flow control character.
1826  *
1827  *      uart_parse_options decodes a string containing the serial console
1828  *      options.  The format of the string is <baud><parity><bits><flow>,
1829  *      eg: 115200n8r
1830  */
1831 void __init
1832 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1833 {
1834         char *s = options;
1835
1836         *baud = simple_strtoul(s, NULL, 10);
1837         while (*s >= '0' && *s <= '9')
1838                 s++;
1839         if (*s)
1840                 *parity = *s++;
1841         if (*s)
1842                 *bits = *s++ - '0';
1843         if (*s)
1844                 *flow = *s;
1845 }
1846
1847 struct baud_rates {
1848         unsigned int rate;
1849         unsigned int cflag;
1850 };
1851
1852 static const struct baud_rates baud_rates[] = {
1853         { 921600, B921600 },
1854         { 460800, B460800 },
1855         { 230400, B230400 },
1856         { 115200, B115200 },
1857         {  57600, B57600  },
1858         {  38400, B38400  },
1859         {  19200, B19200  },
1860         {   9600, B9600   },
1861         {   4800, B4800   },
1862         {   2400, B2400   },
1863         {   1200, B1200   },
1864         {      0, B38400  }
1865 };
1866
1867 /**
1868  *      uart_set_options - setup the serial console parameters
1869  *      @port: pointer to the serial ports uart_port structure
1870  *      @co: console pointer
1871  *      @baud: baud rate
1872  *      @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1873  *      @bits: number of data bits
1874  *      @flow: flow control character - 'r' (rts)
1875  */
1876 int __init
1877 uart_set_options(struct uart_port *port, struct console *co,
1878                  int baud, int parity, int bits, int flow)
1879 {
1880         struct ktermios termios;
1881         int i;
1882
1883         /*
1884          * Ensure that the serial console lock is initialised
1885          * early.
1886          */
1887         spin_lock_init(&port->lock);
1888         lockdep_set_class(&port->lock, &port_lock_key);
1889
1890         memset(&termios, 0, sizeof(struct ktermios));
1891
1892         termios.c_cflag = CREAD | HUPCL | CLOCAL;
1893
1894         /*
1895          * Construct a cflag setting.
1896          */
1897         for (i = 0; baud_rates[i].rate; i++)
1898                 if (baud_rates[i].rate <= baud)
1899                         break;
1900
1901         termios.c_cflag |= baud_rates[i].cflag;
1902
1903         if (bits == 7)
1904                 termios.c_cflag |= CS7;
1905         else
1906                 termios.c_cflag |= CS8;
1907
1908         switch (parity) {
1909         case 'o': case 'O':
1910                 termios.c_cflag |= PARODD;
1911                 /*fall through*/
1912         case 'e': case 'E':
1913                 termios.c_cflag |= PARENB;
1914                 break;
1915         }
1916
1917         if (flow == 'r')
1918                 termios.c_cflag |= CRTSCTS;
1919
1920         port->ops->set_termios(port, &termios, NULL);
1921         co->cflag = termios.c_cflag;
1922
1923         return 0;
1924 }
1925 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1926
1927 static void uart_change_pm(struct uart_state *state, int pm_state)
1928 {
1929         struct uart_port *port = state->port;
1930
1931         if (state->pm_state != pm_state) {
1932                 if (port->ops->pm)
1933                         port->ops->pm(port, pm_state, state->pm_state);
1934                 state->pm_state = pm_state;
1935         }
1936 }
1937
1938 int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
1939 {
1940         struct uart_state *state = drv->state + port->line;
1941
1942         mutex_lock(&state->mutex);
1943
1944 #ifdef CONFIG_DISABLE_CONSOLE_SUSPEND
1945         if (uart_console(port)) {
1946                 mutex_unlock(&state->mutex);
1947                 return 0;
1948         }
1949 #endif
1950
1951         if (state->info && state->info->flags & UIF_INITIALIZED) {
1952                 const struct uart_ops *ops = port->ops;
1953
1954                 state->info->flags = (state->info->flags & ~UIF_INITIALIZED)
1955                                      | UIF_SUSPENDED;
1956
1957                 spin_lock_irq(&port->lock);
1958                 ops->stop_tx(port);
1959                 ops->set_mctrl(port, 0);
1960                 ops->stop_rx(port);
1961                 spin_unlock_irq(&port->lock);
1962
1963                 /*
1964                  * Wait for the transmitter to empty.
1965                  */
1966                 while (!ops->tx_empty(port)) {
1967                         msleep(10);
1968                 }
1969
1970                 ops->shutdown(port);
1971         }
1972
1973         /*
1974          * Disable the console device before suspending.
1975          */
1976         if (uart_console(port))
1977                 console_stop(port->cons);
1978
1979         uart_change_pm(state, 3);
1980
1981         mutex_unlock(&state->mutex);
1982
1983         return 0;
1984 }
1985
1986 int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
1987 {
1988         struct uart_state *state = drv->state + port->line;
1989
1990         mutex_lock(&state->mutex);
1991
1992 #ifdef CONFIG_DISABLE_CONSOLE_SUSPEND
1993         if (uart_console(port)) {
1994                 mutex_unlock(&state->mutex);
1995                 return 0;
1996         }
1997 #endif
1998
1999         uart_change_pm(state, 0);
2000
2001         /*
2002          * Re-enable the console device after suspending.
2003          */
2004         if (uart_console(port)) {
2005                 struct ktermios termios;
2006
2007                 /*
2008                  * First try to use the console cflag setting.
2009                  */
2010                 memset(&termios, 0, sizeof(struct ktermios));
2011                 termios.c_cflag = port->cons->cflag;
2012
2013                 /*
2014                  * If that's unset, use the tty termios setting.
2015                  */
2016                 if (state->info && state->info->tty && termios.c_cflag == 0)
2017                         termios = *state->info->tty->termios;
2018
2019                 port->ops->set_termios(port, &termios, NULL);
2020                 console_start(port->cons);
2021         }
2022
2023         if (state->info && state->info->flags & UIF_SUSPENDED) {
2024                 const struct uart_ops *ops = port->ops;
2025                 int ret;
2026
2027                 ops->set_mctrl(port, 0);
2028                 ret = ops->startup(port);
2029                 if (ret == 0) {
2030                         uart_change_speed(state, NULL);
2031                         spin_lock_irq(&port->lock);
2032                         ops->set_mctrl(port, port->mctrl);
2033                         ops->start_tx(port);
2034                         spin_unlock_irq(&port->lock);
2035                         state->info->flags |= UIF_INITIALIZED;
2036                 } else {
2037                         /*
2038                          * Failed to resume - maybe hardware went away?
2039                          * Clear the "initialized" flag so we won't try
2040                          * to call the low level drivers shutdown method.
2041                          */
2042                         uart_shutdown(state);
2043                 }
2044
2045                 state->info->flags &= ~UIF_SUSPENDED;
2046         }
2047
2048         mutex_unlock(&state->mutex);
2049
2050         return 0;
2051 }
2052
2053 static inline void
2054 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2055 {
2056         char address[64];
2057
2058         switch (port->iotype) {
2059         case UPIO_PORT:
2060                 snprintf(address, sizeof(address),
2061                          "I/O 0x%x", port->iobase);
2062                 break;
2063         case UPIO_HUB6:
2064                 snprintf(address, sizeof(address),
2065                          "I/O 0x%x offset 0x%x", port->iobase, port->hub6);
2066                 break;
2067         case UPIO_MEM:
2068         case UPIO_MEM32:
2069         case UPIO_AU:
2070         case UPIO_TSI:
2071         case UPIO_DWAPB:
2072                 snprintf(address, sizeof(address),
2073                          "MMIO 0x%lx", port->mapbase);
2074                 break;
2075         default:
2076                 strlcpy(address, "*unknown*", sizeof(address));
2077                 break;
2078         }
2079
2080         printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2081                port->dev ? port->dev->bus_id : "",
2082                port->dev ? ": " : "",
2083                drv->dev_name, port->line, address, port->irq, uart_type(port));
2084 }
2085
2086 static void
2087 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2088                     struct uart_port *port)
2089 {
2090         unsigned int flags;
2091
2092         /*
2093          * If there isn't a port here, don't do anything further.
2094          */
2095         if (!port->iobase && !port->mapbase && !port->membase)
2096                 return;
2097
2098         /*
2099          * Now do the auto configuration stuff.  Note that config_port
2100          * is expected to claim the resources and map the port for us.
2101          */
2102         flags = UART_CONFIG_TYPE;
2103         if (port->flags & UPF_AUTO_IRQ)
2104                 flags |= UART_CONFIG_IRQ;
2105         if (port->flags & UPF_BOOT_AUTOCONF) {
2106                 port->type = PORT_UNKNOWN;
2107                 port->ops->config_port(port, flags);
2108         }
2109
2110         if (port->type != PORT_UNKNOWN) {
2111                 unsigned long flags;
2112
2113                 uart_report_port(drv, port);
2114
2115                 /* Power up port for set_mctrl() */
2116                 uart_change_pm(state, 0);
2117
2118                 /*
2119                  * Ensure that the modem control lines are de-activated.
2120                  * We probably don't need a spinlock around this, but
2121                  */
2122                 spin_lock_irqsave(&port->lock, flags);
2123                 port->ops->set_mctrl(port, 0);
2124                 spin_unlock_irqrestore(&port->lock, flags);
2125
2126                 /*
2127                  * Power down all ports by default, except the
2128                  * console if we have one.
2129                  */
2130                 if (!uart_console(port))
2131                         uart_change_pm(state, 3);
2132         }
2133 }
2134
2135 static const struct tty_operations uart_ops = {
2136         .open           = uart_open,
2137         .close          = uart_close,
2138         .write          = uart_write,
2139         .put_char       = uart_put_char,
2140         .flush_chars    = uart_flush_chars,
2141         .write_room     = uart_write_room,
2142         .chars_in_buffer= uart_chars_in_buffer,
2143         .flush_buffer   = uart_flush_buffer,
2144         .ioctl          = uart_ioctl,
2145         .throttle       = uart_throttle,
2146         .unthrottle     = uart_unthrottle,
2147         .send_xchar     = uart_send_xchar,
2148         .set_termios    = uart_set_termios,
2149         .stop           = uart_stop,
2150         .start          = uart_start,
2151         .hangup         = uart_hangup,
2152         .break_ctl      = uart_break_ctl,
2153         .wait_until_sent= uart_wait_until_sent,
2154 #ifdef CONFIG_PROC_FS
2155         .read_proc      = uart_read_proc,
2156 #endif
2157         .tiocmget       = uart_tiocmget,
2158         .tiocmset       = uart_tiocmset,
2159 };
2160
2161 /**
2162  *      uart_register_driver - register a driver with the uart core layer
2163  *      @drv: low level driver structure
2164  *
2165  *      Register a uart driver with the core driver.  We in turn register
2166  *      with the tty layer, and initialise the core driver per-port state.
2167  *
2168  *      We have a proc file in /proc/tty/driver which is named after the
2169  *      normal driver.
2170  *
2171  *      drv->port should be NULL, and the per-port structures should be
2172  *      registered using uart_add_one_port after this call has succeeded.
2173  */
2174 int uart_register_driver(struct uart_driver *drv)
2175 {
2176         struct tty_driver *normal = NULL;
2177         int i, retval;
2178
2179         BUG_ON(drv->state);
2180
2181         /*
2182          * Maybe we should be using a slab cache for this, especially if
2183          * we have a large number of ports to handle.
2184          */
2185         drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2186         retval = -ENOMEM;
2187         if (!drv->state)
2188                 goto out;
2189
2190         normal  = alloc_tty_driver(drv->nr);
2191         if (!normal)
2192                 goto out;
2193
2194         drv->tty_driver = normal;
2195
2196         normal->owner           = drv->owner;
2197         normal->driver_name     = drv->driver_name;
2198         normal->name            = drv->dev_name;
2199         normal->major           = drv->major;
2200         normal->minor_start     = drv->minor;
2201         normal->type            = TTY_DRIVER_TYPE_SERIAL;
2202         normal->subtype         = SERIAL_TYPE_NORMAL;
2203         normal->init_termios    = tty_std_termios;
2204         normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2205         normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2206         normal->flags           = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2207         normal->driver_state    = drv;
2208         tty_set_operations(normal, &uart_ops);
2209
2210         /*
2211          * Initialise the UART state(s).
2212          */
2213         for (i = 0; i < drv->nr; i++) {
2214                 struct uart_state *state = drv->state + i;
2215
2216                 state->close_delay     = 500;   /* .5 seconds */
2217                 state->closing_wait    = 30000; /* 30 seconds */
2218
2219                 mutex_init(&state->mutex);
2220         }
2221
2222         retval = tty_register_driver(normal);
2223  out:
2224         if (retval < 0) {
2225                 put_tty_driver(normal);
2226                 kfree(drv->state);
2227         }
2228         return retval;
2229 }
2230
2231 /**
2232  *      uart_unregister_driver - remove a driver from the uart core layer
2233  *      @drv: low level driver structure
2234  *
2235  *      Remove all references to a driver from the core driver.  The low
2236  *      level driver must have removed all its ports via the
2237  *      uart_remove_one_port() if it registered them with uart_add_one_port().
2238  *      (ie, drv->port == NULL)
2239  */
2240 void uart_unregister_driver(struct uart_driver *drv)
2241 {
2242         struct tty_driver *p = drv->tty_driver;
2243         tty_unregister_driver(p);
2244         put_tty_driver(p);
2245         kfree(drv->state);
2246         drv->tty_driver = NULL;
2247 }
2248
2249 struct tty_driver *uart_console_device(struct console *co, int *index)
2250 {
2251         struct uart_driver *p = co->data;
2252         *index = co->index;
2253         return p->tty_driver;
2254 }
2255
2256 /**
2257  *      uart_add_one_port - attach a driver-defined port structure
2258  *      @drv: pointer to the uart low level driver structure for this port
2259  *      @port: uart port structure to use for this port.
2260  *
2261  *      This allows the driver to register its own uart_port structure
2262  *      with the core driver.  The main purpose is to allow the low
2263  *      level uart drivers to expand uart_port, rather than having yet
2264  *      more levels of structures.
2265  */
2266 int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
2267 {
2268         struct uart_state *state;
2269         int ret = 0;
2270
2271         BUG_ON(in_interrupt());
2272
2273         if (port->line >= drv->nr)
2274                 return -EINVAL;
2275
2276         state = drv->state + port->line;
2277
2278         mutex_lock(&port_mutex);
2279         mutex_lock(&state->mutex);
2280         if (state->port) {
2281                 ret = -EINVAL;
2282                 goto out;
2283         }
2284
2285         state->port = port;
2286
2287         port->cons = drv->cons;
2288         port->info = state->info;
2289
2290         /*
2291          * If this port is a console, then the spinlock is already
2292          * initialised.
2293          */
2294         if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
2295                 spin_lock_init(&port->lock);
2296                 lockdep_set_class(&port->lock, &port_lock_key);
2297         }
2298
2299         uart_configure_port(drv, state, port);
2300
2301         /*
2302          * Register the port whether it's detected or not.  This allows
2303          * setserial to be used to alter this ports parameters.
2304          */
2305         tty_register_device(drv->tty_driver, port->line, port->dev);
2306
2307         /*
2308          * If this driver supports console, and it hasn't been
2309          * successfully registered yet, try to re-register it.
2310          * It may be that the port was not available.
2311          */
2312         if (port->type != PORT_UNKNOWN &&
2313             port->cons && !(port->cons->flags & CON_ENABLED))
2314                 register_console(port->cons);
2315
2316         /*
2317          * Ensure UPF_DEAD is not set.
2318          */
2319         port->flags &= ~UPF_DEAD;
2320
2321  out:
2322         mutex_unlock(&state->mutex);
2323         mutex_unlock(&port_mutex);
2324
2325         return ret;
2326 }
2327
2328 /**
2329  *      uart_remove_one_port - detach a driver defined port structure
2330  *      @drv: pointer to the uart low level driver structure for this port
2331  *      @port: uart port structure for this port
2332  *
2333  *      This unhooks (and hangs up) the specified port structure from the
2334  *      core driver.  No further calls will be made to the low-level code
2335  *      for this port.
2336  */
2337 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
2338 {
2339         struct uart_state *state = drv->state + port->line;
2340         struct uart_info *info;
2341
2342         BUG_ON(in_interrupt());
2343
2344         if (state->port != port)
2345                 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2346                         state->port, port);
2347
2348         mutex_lock(&port_mutex);
2349
2350         /*
2351          * Mark the port "dead" - this prevents any opens from
2352          * succeeding while we shut down the port.
2353          */
2354         mutex_lock(&state->mutex);
2355         port->flags |= UPF_DEAD;
2356         mutex_unlock(&state->mutex);
2357
2358         /*
2359          * Remove the devices from the tty layer
2360          */
2361         tty_unregister_device(drv->tty_driver, port->line);
2362
2363         info = state->info;
2364         if (info && info->tty)
2365                 tty_vhangup(info->tty);
2366
2367         /*
2368          * All users of this port should now be disconnected from
2369          * this driver, and the port shut down.  We should be the
2370          * only thread fiddling with this port from now on.
2371          */
2372         state->info = NULL;
2373
2374         /*
2375          * Free the port IO and memory resources, if any.
2376          */
2377         if (port->type != PORT_UNKNOWN)
2378                 port->ops->release_port(port);
2379
2380         /*
2381          * Indicate that there isn't a port here anymore.
2382          */
2383         port->type = PORT_UNKNOWN;
2384
2385         /*
2386          * Kill the tasklet, and free resources.
2387          */
2388         if (info) {
2389                 tasklet_kill(&info->tlet);
2390                 kfree(info);
2391         }
2392
2393         state->port = NULL;
2394         mutex_unlock(&port_mutex);
2395
2396         return 0;
2397 }
2398
2399 /*
2400  *      Are the two ports equivalent?
2401  */
2402 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2403 {
2404         if (port1->iotype != port2->iotype)
2405                 return 0;
2406
2407         switch (port1->iotype) {
2408         case UPIO_PORT:
2409                 return (port1->iobase == port2->iobase);
2410         case UPIO_HUB6:
2411                 return (port1->iobase == port2->iobase) &&
2412                        (port1->hub6   == port2->hub6);
2413         case UPIO_MEM:
2414         case UPIO_MEM32:
2415         case UPIO_AU:
2416         case UPIO_TSI:
2417         case UPIO_DWAPB:
2418                 return (port1->mapbase == port2->mapbase);
2419         }
2420         return 0;
2421 }
2422 EXPORT_SYMBOL(uart_match_port);
2423
2424 EXPORT_SYMBOL(uart_write_wakeup);
2425 EXPORT_SYMBOL(uart_register_driver);
2426 EXPORT_SYMBOL(uart_unregister_driver);
2427 EXPORT_SYMBOL(uart_suspend_port);
2428 EXPORT_SYMBOL(uart_resume_port);
2429 EXPORT_SYMBOL(uart_add_one_port);
2430 EXPORT_SYMBOL(uart_remove_one_port);
2431
2432 MODULE_DESCRIPTION("Serial driver core");
2433 MODULE_LICENSE("GPL");