Merge with /pub/scm/linux/kernel/git/torvalds/linux-2.6.git
[linux-2.6] / drivers / serial / serial_core.c
1 /*
2  *  linux/drivers/char/core.c
3  *
4  *  Driver core for serial ports
5  *
6  *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
7  *
8  *  Copyright 1999 ARM Limited
9  *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
24  */
25 #include <linux/config.h>
26 #include <linux/module.h>
27 #include <linux/tty.h>
28 #include <linux/slab.h>
29 #include <linux/init.h>
30 #include <linux/console.h>
31 #include <linux/serial_core.h>
32 #include <linux/smp_lock.h>
33 #include <linux/device.h>
34 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
35 #include <linux/delay.h>
36 #include <linux/mutex.h>
37
38 #include <asm/irq.h>
39 #include <asm/uaccess.h>
40
41 #undef  DEBUG
42 #ifdef DEBUG
43 #define DPRINTK(x...)   printk(x)
44 #else
45 #define DPRINTK(x...)   do { } while (0)
46 #endif
47
48 /*
49  * This is used to lock changes in serial line configuration.
50  */
51 static DEFINE_MUTEX(port_mutex);
52
53 #define HIGH_BITS_OFFSET        ((sizeof(long)-sizeof(int))*8)
54
55 #define uart_users(state)       ((state)->count + ((state)->info ? (state)->info->blocked_open : 0))
56
57 #ifdef CONFIG_SERIAL_CORE_CONSOLE
58 #define uart_console(port)      ((port)->cons && (port)->cons->index == (port)->line)
59 #else
60 #define uart_console(port)      (0)
61 #endif
62
63 static void uart_change_speed(struct uart_state *state, struct termios *old_termios);
64 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
65 static void uart_change_pm(struct uart_state *state, int pm_state);
66
67 /*
68  * This routine is used by the interrupt handler to schedule processing in
69  * the software interrupt portion of the driver.
70  */
71 void uart_write_wakeup(struct uart_port *port)
72 {
73         struct uart_info *info = port->info;
74         tasklet_schedule(&info->tlet);
75 }
76
77 static void uart_stop(struct tty_struct *tty)
78 {
79         struct uart_state *state = tty->driver_data;
80         struct uart_port *port = state->port;
81         unsigned long flags;
82
83         spin_lock_irqsave(&port->lock, flags);
84         port->ops->stop_tx(port);
85         spin_unlock_irqrestore(&port->lock, flags);
86 }
87
88 static void __uart_start(struct tty_struct *tty)
89 {
90         struct uart_state *state = tty->driver_data;
91         struct uart_port *port = state->port;
92
93         if (!uart_circ_empty(&state->info->xmit) && state->info->xmit.buf &&
94             !tty->stopped && !tty->hw_stopped)
95                 port->ops->start_tx(port);
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         unsigned long flags;
103
104         spin_lock_irqsave(&port->lock, flags);
105         __uart_start(tty);
106         spin_unlock_irqrestore(&port->lock, flags);
107 }
108
109 static void uart_tasklet_action(unsigned long data)
110 {
111         struct uart_state *state = (struct uart_state *)data;
112         tty_wakeup(state->info->tty);
113 }
114
115 static inline void
116 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
117 {
118         unsigned long flags;
119         unsigned int old;
120
121         spin_lock_irqsave(&port->lock, flags);
122         old = port->mctrl;
123         port->mctrl = (old & ~clear) | set;
124         if (old != port->mctrl)
125                 port->ops->set_mctrl(port, port->mctrl);
126         spin_unlock_irqrestore(&port->lock, flags);
127 }
128
129 #define uart_set_mctrl(port,set)        uart_update_mctrl(port,set,0)
130 #define uart_clear_mctrl(port,clear)    uart_update_mctrl(port,0,clear)
131
132 /*
133  * Startup the port.  This will be called once per open.  All calls
134  * will be serialised by the per-port semaphore.
135  */
136 static int uart_startup(struct uart_state *state, int init_hw)
137 {
138         struct uart_info *info = state->info;
139         struct uart_port *port = state->port;
140         unsigned long page;
141         int retval = 0;
142
143         if (info->flags & UIF_INITIALIZED)
144                 return 0;
145
146         /*
147          * Set the TTY IO error marker - we will only clear this
148          * once we have successfully opened the port.  Also set
149          * up the tty->alt_speed kludge
150          */
151         set_bit(TTY_IO_ERROR, &info->tty->flags);
152
153         if (port->type == PORT_UNKNOWN)
154                 return 0;
155
156         /*
157          * Initialise and allocate the transmit and temporary
158          * buffer.
159          */
160         if (!info->xmit.buf) {
161                 page = get_zeroed_page(GFP_KERNEL);
162                 if (!page)
163                         return -ENOMEM;
164
165                 info->xmit.buf = (unsigned char *) page;
166                 uart_circ_clear(&info->xmit);
167         }
168
169         retval = port->ops->startup(port);
170         if (retval == 0) {
171                 if (init_hw) {
172                         /*
173                          * Initialise the hardware port settings.
174                          */
175                         uart_change_speed(state, NULL);
176
177                         /*
178                          * Setup the RTS and DTR signals once the
179                          * port is open and ready to respond.
180                          */
181                         if (info->tty->termios->c_cflag & CBAUD)
182                                 uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
183                 }
184
185                 if (info->flags & UIF_CTS_FLOW) {
186                         spin_lock_irq(&port->lock);
187                         if (!(port->ops->get_mctrl(port) & TIOCM_CTS))
188                                 info->tty->hw_stopped = 1;
189                         spin_unlock_irq(&port->lock);
190                 }
191
192                 info->flags |= UIF_INITIALIZED;
193
194                 clear_bit(TTY_IO_ERROR, &info->tty->flags);
195         }
196
197         if (retval && capable(CAP_SYS_ADMIN))
198                 retval = 0;
199
200         return retval;
201 }
202
203 /*
204  * This routine will shutdown a serial port; interrupts are disabled, and
205  * DTR is dropped if the hangup on close termio flag is on.  Calls to
206  * uart_shutdown are serialised by the per-port semaphore.
207  */
208 static void uart_shutdown(struct uart_state *state)
209 {
210         struct uart_info *info = state->info;
211         struct uart_port *port = state->port;
212
213         /*
214          * Set the TTY IO error marker
215          */
216         if (info->tty)
217                 set_bit(TTY_IO_ERROR, &info->tty->flags);
218
219         if (info->flags & UIF_INITIALIZED) {
220                 info->flags &= ~UIF_INITIALIZED;
221
222                 /*
223                  * Turn off DTR and RTS early.
224                  */
225                 if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
226                         uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
227
228                 /*
229                  * clear delta_msr_wait queue to avoid mem leaks: we may free
230                  * the irq here so the queue might never be woken up.  Note
231                  * that we won't end up waiting on delta_msr_wait again since
232                  * any outstanding file descriptors should be pointing at
233                  * hung_up_tty_fops now.
234                  */
235                 wake_up_interruptible(&info->delta_msr_wait);
236
237                 /*
238                  * Free the IRQ and disable the port.
239                  */
240                 port->ops->shutdown(port);
241
242                 /*
243                  * Ensure that the IRQ handler isn't running on another CPU.
244                  */
245                 synchronize_irq(port->irq);
246         }
247
248         /*
249          * kill off our tasklet
250          */
251         tasklet_kill(&info->tlet);
252
253         /*
254          * Free the transmit buffer page.
255          */
256         if (info->xmit.buf) {
257                 free_page((unsigned long)info->xmit.buf);
258                 info->xmit.buf = NULL;
259         }
260 }
261
262 /**
263  *      uart_update_timeout - update per-port FIFO timeout.
264  *      @port:  uart_port structure describing the port
265  *      @cflag: termios cflag value
266  *      @baud:  speed of the port
267  *
268  *      Set the port FIFO timeout value.  The @cflag value should
269  *      reflect the actual hardware settings.
270  */
271 void
272 uart_update_timeout(struct uart_port *port, unsigned int cflag,
273                     unsigned int baud)
274 {
275         unsigned int bits;
276
277         /* byte size and parity */
278         switch (cflag & CSIZE) {
279         case CS5:
280                 bits = 7;
281                 break;
282         case CS6:
283                 bits = 8;
284                 break;
285         case CS7:
286                 bits = 9;
287                 break;
288         default:
289                 bits = 10;
290                 break; // CS8
291         }
292
293         if (cflag & CSTOPB)
294                 bits++;
295         if (cflag & PARENB)
296                 bits++;
297
298         /*
299          * The total number of bits to be transmitted in the fifo.
300          */
301         bits = bits * port->fifosize;
302
303         /*
304          * Figure the timeout to send the above number of bits.
305          * Add .02 seconds of slop
306          */
307         port->timeout = (HZ * bits) / baud + HZ/50;
308 }
309
310 EXPORT_SYMBOL(uart_update_timeout);
311
312 /**
313  *      uart_get_baud_rate - return baud rate for a particular port
314  *      @port: uart_port structure describing the port in question.
315  *      @termios: desired termios settings.
316  *      @old: old termios (or NULL)
317  *      @min: minimum acceptable baud rate
318  *      @max: maximum acceptable baud rate
319  *
320  *      Decode the termios structure into a numeric baud rate,
321  *      taking account of the magic 38400 baud rate (with spd_*
322  *      flags), and mapping the %B0 rate to 9600 baud.
323  *
324  *      If the new baud rate is invalid, try the old termios setting.
325  *      If it's still invalid, we try 9600 baud.
326  *
327  *      Update the @termios structure to reflect the baud rate
328  *      we're actually going to be using.
329  */
330 unsigned int
331 uart_get_baud_rate(struct uart_port *port, struct termios *termios,
332                    struct termios *old, unsigned int min, unsigned int max)
333 {
334         unsigned int try, baud, altbaud = 38400;
335         unsigned int flags = port->flags & UPF_SPD_MASK;
336
337         if (flags == UPF_SPD_HI)
338                 altbaud = 57600;
339         if (flags == UPF_SPD_VHI)
340                 altbaud = 115200;
341         if (flags == UPF_SPD_SHI)
342                 altbaud = 230400;
343         if (flags == UPF_SPD_WARP)
344                 altbaud = 460800;
345
346         for (try = 0; try < 2; try++) {
347                 baud = tty_termios_baud_rate(termios);
348
349                 /*
350                  * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
351                  * Die! Die! Die!
352                  */
353                 if (baud == 38400)
354                         baud = altbaud;
355
356                 /*
357                  * Special case: B0 rate.
358                  */
359                 if (baud == 0)
360                         baud = 9600;
361
362                 if (baud >= min && baud <= max)
363                         return baud;
364
365                 /*
366                  * Oops, the quotient was zero.  Try again with
367                  * the old baud rate if possible.
368                  */
369                 termios->c_cflag &= ~CBAUD;
370                 if (old) {
371                         termios->c_cflag |= old->c_cflag & CBAUD;
372                         old = NULL;
373                         continue;
374                 }
375
376                 /*
377                  * As a last resort, if the quotient is zero,
378                  * default to 9600 bps
379                  */
380                 termios->c_cflag |= B9600;
381         }
382
383         return 0;
384 }
385
386 EXPORT_SYMBOL(uart_get_baud_rate);
387
388 /**
389  *      uart_get_divisor - return uart clock divisor
390  *      @port: uart_port structure describing the port.
391  *      @baud: desired baud rate
392  *
393  *      Calculate the uart clock divisor for the port.
394  */
395 unsigned int
396 uart_get_divisor(struct uart_port *port, unsigned int baud)
397 {
398         unsigned int quot;
399
400         /*
401          * Old custom speed handling.
402          */
403         if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
404                 quot = port->custom_divisor;
405         else
406                 quot = (port->uartclk + (8 * baud)) / (16 * baud);
407
408         return quot;
409 }
410
411 EXPORT_SYMBOL(uart_get_divisor);
412
413 static void
414 uart_change_speed(struct uart_state *state, struct termios *old_termios)
415 {
416         struct tty_struct *tty = state->info->tty;
417         struct uart_port *port = state->port;
418         struct termios *termios;
419
420         /*
421          * If we have no tty, termios, or the port does not exist,
422          * then we can't set the parameters for this port.
423          */
424         if (!tty || !tty->termios || port->type == PORT_UNKNOWN)
425                 return;
426
427         termios = tty->termios;
428
429         /*
430          * Set flags based on termios cflag
431          */
432         if (termios->c_cflag & CRTSCTS)
433                 state->info->flags |= UIF_CTS_FLOW;
434         else
435                 state->info->flags &= ~UIF_CTS_FLOW;
436
437         if (termios->c_cflag & CLOCAL)
438                 state->info->flags &= ~UIF_CHECK_CD;
439         else
440                 state->info->flags |= UIF_CHECK_CD;
441
442         port->ops->set_termios(port, termios, old_termios);
443 }
444
445 static inline void
446 __uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c)
447 {
448         unsigned long flags;
449
450         if (!circ->buf)
451                 return;
452
453         spin_lock_irqsave(&port->lock, flags);
454         if (uart_circ_chars_free(circ) != 0) {
455                 circ->buf[circ->head] = c;
456                 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
457         }
458         spin_unlock_irqrestore(&port->lock, flags);
459 }
460
461 static void uart_put_char(struct tty_struct *tty, unsigned char ch)
462 {
463         struct uart_state *state = tty->driver_data;
464
465         __uart_put_char(state->port, &state->info->xmit, ch);
466 }
467
468 static void uart_flush_chars(struct tty_struct *tty)
469 {
470         uart_start(tty);
471 }
472
473 static int
474 uart_write(struct tty_struct *tty, const unsigned char * buf, int count)
475 {
476         struct uart_state *state = tty->driver_data;
477         struct uart_port *port = state->port;
478         struct circ_buf *circ = &state->info->xmit;
479         unsigned long flags;
480         int c, ret = 0;
481
482         if (!circ->buf)
483                 return 0;
484
485         spin_lock_irqsave(&port->lock, flags);
486         while (1) {
487                 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
488                 if (count < c)
489                         c = count;
490                 if (c <= 0)
491                         break;
492                 memcpy(circ->buf + circ->head, buf, c);
493                 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
494                 buf += c;
495                 count -= c;
496                 ret += c;
497         }
498         spin_unlock_irqrestore(&port->lock, flags);
499
500         uart_start(tty);
501         return ret;
502 }
503
504 static int uart_write_room(struct tty_struct *tty)
505 {
506         struct uart_state *state = tty->driver_data;
507
508         return uart_circ_chars_free(&state->info->xmit);
509 }
510
511 static int uart_chars_in_buffer(struct tty_struct *tty)
512 {
513         struct uart_state *state = tty->driver_data;
514
515         return uart_circ_chars_pending(&state->info->xmit);
516 }
517
518 static void uart_flush_buffer(struct tty_struct *tty)
519 {
520         struct uart_state *state = tty->driver_data;
521         struct uart_port *port = state->port;
522         unsigned long flags;
523
524         DPRINTK("uart_flush_buffer(%d) called\n", tty->index);
525
526         spin_lock_irqsave(&port->lock, flags);
527         uart_circ_clear(&state->info->xmit);
528         spin_unlock_irqrestore(&port->lock, flags);
529         tty_wakeup(tty);
530 }
531
532 /*
533  * This function is used to send a high-priority XON/XOFF character to
534  * the device
535  */
536 static void uart_send_xchar(struct tty_struct *tty, char ch)
537 {
538         struct uart_state *state = tty->driver_data;
539         struct uart_port *port = state->port;
540         unsigned long flags;
541
542         if (port->ops->send_xchar)
543                 port->ops->send_xchar(port, ch);
544         else {
545                 port->x_char = ch;
546                 if (ch) {
547                         spin_lock_irqsave(&port->lock, flags);
548                         port->ops->start_tx(port);
549                         spin_unlock_irqrestore(&port->lock, flags);
550                 }
551         }
552 }
553
554 static void uart_throttle(struct tty_struct *tty)
555 {
556         struct uart_state *state = tty->driver_data;
557
558         if (I_IXOFF(tty))
559                 uart_send_xchar(tty, STOP_CHAR(tty));
560
561         if (tty->termios->c_cflag & CRTSCTS)
562                 uart_clear_mctrl(state->port, TIOCM_RTS);
563 }
564
565 static void uart_unthrottle(struct tty_struct *tty)
566 {
567         struct uart_state *state = tty->driver_data;
568         struct uart_port *port = state->port;
569
570         if (I_IXOFF(tty)) {
571                 if (port->x_char)
572                         port->x_char = 0;
573                 else
574                         uart_send_xchar(tty, START_CHAR(tty));
575         }
576
577         if (tty->termios->c_cflag & CRTSCTS)
578                 uart_set_mctrl(port, TIOCM_RTS);
579 }
580
581 static int uart_get_info(struct uart_state *state,
582                          struct serial_struct __user *retinfo)
583 {
584         struct uart_port *port = state->port;
585         struct serial_struct tmp;
586
587         memset(&tmp, 0, sizeof(tmp));
588         tmp.type            = port->type;
589         tmp.line            = port->line;
590         tmp.port            = port->iobase;
591         if (HIGH_BITS_OFFSET)
592                 tmp.port_high = (long) port->iobase >> HIGH_BITS_OFFSET;
593         tmp.irq             = port->irq;
594         tmp.flags           = port->flags;
595         tmp.xmit_fifo_size  = port->fifosize;
596         tmp.baud_base       = port->uartclk / 16;
597         tmp.close_delay     = state->close_delay / 10;
598         tmp.closing_wait    = state->closing_wait == USF_CLOSING_WAIT_NONE ?
599                                 ASYNC_CLOSING_WAIT_NONE :
600                                 state->closing_wait / 10;
601         tmp.custom_divisor  = port->custom_divisor;
602         tmp.hub6            = port->hub6;
603         tmp.io_type         = port->iotype;
604         tmp.iomem_reg_shift = port->regshift;
605         tmp.iomem_base      = (void *)port->mapbase;
606
607         if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
608                 return -EFAULT;
609         return 0;
610 }
611
612 static int uart_set_info(struct uart_state *state,
613                          struct serial_struct __user *newinfo)
614 {
615         struct serial_struct new_serial;
616         struct uart_port *port = state->port;
617         unsigned long new_port;
618         unsigned int change_irq, change_port, old_flags, closing_wait;
619         unsigned int old_custom_divisor, close_delay;
620         int retval = 0;
621
622         if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
623                 return -EFAULT;
624
625         new_port = new_serial.port;
626         if (HIGH_BITS_OFFSET)
627                 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
628
629         new_serial.irq = irq_canonicalize(new_serial.irq);
630         close_delay = new_serial.close_delay * 10;
631         closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
632                         USF_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
633
634         /*
635          * This semaphore protects state->count.  It is also
636          * very useful to prevent opens.  Also, take the
637          * port configuration semaphore to make sure that a
638          * module insertion/removal doesn't change anything
639          * under us.
640          */
641         mutex_lock(&state->mutex);
642
643         change_irq  = new_serial.irq != port->irq;
644
645         /*
646          * Since changing the 'type' of the port changes its resource
647          * allocations, we should treat type changes the same as
648          * IO port changes.
649          */
650         change_port = new_port != port->iobase ||
651                       (unsigned long)new_serial.iomem_base != port->mapbase ||
652                       new_serial.hub6 != port->hub6 ||
653                       new_serial.io_type != port->iotype ||
654                       new_serial.iomem_reg_shift != port->regshift ||
655                       new_serial.type != port->type;
656
657         old_flags = port->flags;
658         old_custom_divisor = port->custom_divisor;
659
660         if (!capable(CAP_SYS_ADMIN)) {
661                 retval = -EPERM;
662                 if (change_irq || change_port ||
663                     (new_serial.baud_base != port->uartclk / 16) ||
664                     (close_delay != state->close_delay) ||
665                     (closing_wait != state->closing_wait) ||
666                     (new_serial.xmit_fifo_size != port->fifosize) ||
667                     (((new_serial.flags ^ old_flags) & ~UPF_USR_MASK) != 0))
668                         goto exit;
669                 port->flags = ((port->flags & ~UPF_USR_MASK) |
670                                (new_serial.flags & UPF_USR_MASK));
671                 port->custom_divisor = new_serial.custom_divisor;
672                 goto check_and_exit;
673         }
674
675         /*
676          * Ask the low level driver to verify the settings.
677          */
678         if (port->ops->verify_port)
679                 retval = port->ops->verify_port(port, &new_serial);
680
681         if ((new_serial.irq >= NR_IRQS) || (new_serial.irq < 0) ||
682             (new_serial.baud_base < 9600))
683                 retval = -EINVAL;
684
685         if (retval)
686                 goto exit;
687
688         if (change_port || change_irq) {
689                 retval = -EBUSY;
690
691                 /*
692                  * Make sure that we are the sole user of this port.
693                  */
694                 if (uart_users(state) > 1)
695                         goto exit;
696
697                 /*
698                  * We need to shutdown the serial port at the old
699                  * port/type/irq combination.
700                  */
701                 uart_shutdown(state);
702         }
703
704         if (change_port) {
705                 unsigned long old_iobase, old_mapbase;
706                 unsigned int old_type, old_iotype, old_hub6, old_shift;
707
708                 old_iobase = port->iobase;
709                 old_mapbase = port->mapbase;
710                 old_type = port->type;
711                 old_hub6 = port->hub6;
712                 old_iotype = port->iotype;
713                 old_shift = port->regshift;
714
715                 /*
716                  * Free and release old regions
717                  */
718                 if (old_type != PORT_UNKNOWN)
719                         port->ops->release_port(port);
720
721                 port->iobase = new_port;
722                 port->type = new_serial.type;
723                 port->hub6 = new_serial.hub6;
724                 port->iotype = new_serial.io_type;
725                 port->regshift = new_serial.iomem_reg_shift;
726                 port->mapbase = (unsigned long)new_serial.iomem_base;
727
728                 /*
729                  * Claim and map the new regions
730                  */
731                 if (port->type != PORT_UNKNOWN) {
732                         retval = port->ops->request_port(port);
733                 } else {
734                         /* Always success - Jean II */
735                         retval = 0;
736                 }
737
738                 /*
739                  * If we fail to request resources for the
740                  * new port, try to restore the old settings.
741                  */
742                 if (retval && old_type != PORT_UNKNOWN) {
743                         port->iobase = old_iobase;
744                         port->type = old_type;
745                         port->hub6 = old_hub6;
746                         port->iotype = old_iotype;
747                         port->regshift = old_shift;
748                         port->mapbase = old_mapbase;
749                         retval = port->ops->request_port(port);
750                         /*
751                          * If we failed to restore the old settings,
752                          * we fail like this.
753                          */
754                         if (retval)
755                                 port->type = PORT_UNKNOWN;
756
757                         /*
758                          * We failed anyway.
759                          */
760                         retval = -EBUSY;
761                 }
762         }
763
764         port->irq              = new_serial.irq;
765         port->uartclk          = new_serial.baud_base * 16;
766         port->flags            = (port->flags & ~UPF_CHANGE_MASK) |
767                                  (new_serial.flags & UPF_CHANGE_MASK);
768         port->custom_divisor   = new_serial.custom_divisor;
769         state->close_delay     = close_delay;
770         state->closing_wait    = closing_wait;
771         port->fifosize         = new_serial.xmit_fifo_size;
772         if (state->info->tty)
773                 state->info->tty->low_latency =
774                         (port->flags & UPF_LOW_LATENCY) ? 1 : 0;
775
776  check_and_exit:
777         retval = 0;
778         if (port->type == PORT_UNKNOWN)
779                 goto exit;
780         if (state->info->flags & UIF_INITIALIZED) {
781                 if (((old_flags ^ port->flags) & UPF_SPD_MASK) ||
782                     old_custom_divisor != port->custom_divisor) {
783                         /*
784                          * If they're setting up a custom divisor or speed,
785                          * instead of clearing it, then bitch about it. No
786                          * need to rate-limit; it's CAP_SYS_ADMIN only.
787                          */
788                         if (port->flags & UPF_SPD_MASK) {
789                                 char buf[64];
790                                 printk(KERN_NOTICE
791                                        "%s sets custom speed on %s. This "
792                                        "is deprecated.\n", current->comm,
793                                        tty_name(state->info->tty, buf));
794                         }
795                         uart_change_speed(state, NULL);
796                 }
797         } else
798                 retval = uart_startup(state, 1);
799  exit:
800         mutex_unlock(&state->mutex);
801         return retval;
802 }
803
804
805 /*
806  * uart_get_lsr_info - get line status register info.
807  * Note: uart_ioctl protects us against hangups.
808  */
809 static int uart_get_lsr_info(struct uart_state *state,
810                              unsigned int __user *value)
811 {
812         struct uart_port *port = state->port;
813         unsigned int result;
814
815         result = port->ops->tx_empty(port);
816
817         /*
818          * If we're about to load something into the transmit
819          * register, we'll pretend the transmitter isn't empty to
820          * avoid a race condition (depending on when the transmit
821          * interrupt happens).
822          */
823         if (port->x_char ||
824             ((uart_circ_chars_pending(&state->info->xmit) > 0) &&
825              !state->info->tty->stopped && !state->info->tty->hw_stopped))
826                 result &= ~TIOCSER_TEMT;
827         
828         return put_user(result, value);
829 }
830
831 static int uart_tiocmget(struct tty_struct *tty, struct file *file)
832 {
833         struct uart_state *state = tty->driver_data;
834         struct uart_port *port = state->port;
835         int result = -EIO;
836
837         mutex_lock(&state->mutex);
838         if ((!file || !tty_hung_up_p(file)) &&
839             !(tty->flags & (1 << TTY_IO_ERROR))) {
840                 result = port->mctrl;
841
842                 spin_lock_irq(&port->lock);
843                 result |= port->ops->get_mctrl(port);
844                 spin_unlock_irq(&port->lock);
845         }
846         mutex_unlock(&state->mutex);
847
848         return result;
849 }
850
851 static int
852 uart_tiocmset(struct tty_struct *tty, struct file *file,
853               unsigned int set, unsigned int clear)
854 {
855         struct uart_state *state = tty->driver_data;
856         struct uart_port *port = state->port;
857         int ret = -EIO;
858
859         mutex_lock(&state->mutex);
860         if ((!file || !tty_hung_up_p(file)) &&
861             !(tty->flags & (1 << TTY_IO_ERROR))) {
862                 uart_update_mctrl(port, set, clear);
863                 ret = 0;
864         }
865         mutex_unlock(&state->mutex);
866         return ret;
867 }
868
869 static void uart_break_ctl(struct tty_struct *tty, int break_state)
870 {
871         struct uart_state *state = tty->driver_data;
872         struct uart_port *port = state->port;
873
874         BUG_ON(!kernel_locked());
875
876         mutex_lock(&state->mutex);
877
878         if (port->type != PORT_UNKNOWN)
879                 port->ops->break_ctl(port, break_state);
880
881         mutex_unlock(&state->mutex);
882 }
883
884 static int uart_do_autoconfig(struct uart_state *state)
885 {
886         struct uart_port *port = state->port;
887         int flags, ret;
888
889         if (!capable(CAP_SYS_ADMIN))
890                 return -EPERM;
891
892         /*
893          * Take the per-port semaphore.  This prevents count from
894          * changing, and hence any extra opens of the port while
895          * we're auto-configuring.
896          */
897         if (mutex_lock_interruptible(&state->mutex))
898                 return -ERESTARTSYS;
899
900         ret = -EBUSY;
901         if (uart_users(state) == 1) {
902                 uart_shutdown(state);
903
904                 /*
905                  * If we already have a port type configured,
906                  * we must release its resources.
907                  */
908                 if (port->type != PORT_UNKNOWN)
909                         port->ops->release_port(port);
910
911                 flags = UART_CONFIG_TYPE;
912                 if (port->flags & UPF_AUTO_IRQ)
913                         flags |= UART_CONFIG_IRQ;
914
915                 /*
916                  * This will claim the ports resources if
917                  * a port is found.
918                  */
919                 port->ops->config_port(port, flags);
920
921                 ret = uart_startup(state, 1);
922         }
923         mutex_unlock(&state->mutex);
924         return ret;
925 }
926
927 /*
928  * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
929  * - mask passed in arg for lines of interest
930  *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
931  * Caller should use TIOCGICOUNT to see which one it was
932  */
933 static int
934 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
935 {
936         struct uart_port *port = state->port;
937         DECLARE_WAITQUEUE(wait, current);
938         struct uart_icount cprev, cnow;
939         int ret;
940
941         /*
942          * note the counters on entry
943          */
944         spin_lock_irq(&port->lock);
945         memcpy(&cprev, &port->icount, sizeof(struct uart_icount));
946
947         /*
948          * Force modem status interrupts on
949          */
950         port->ops->enable_ms(port);
951         spin_unlock_irq(&port->lock);
952
953         add_wait_queue(&state->info->delta_msr_wait, &wait);
954         for (;;) {
955                 spin_lock_irq(&port->lock);
956                 memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
957                 spin_unlock_irq(&port->lock);
958
959                 set_current_state(TASK_INTERRUPTIBLE);
960
961                 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
962                     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
963                     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
964                     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
965                         ret = 0;
966                         break;
967                 }
968
969                 schedule();
970
971                 /* see if a signal did it */
972                 if (signal_pending(current)) {
973                         ret = -ERESTARTSYS;
974                         break;
975                 }
976
977                 cprev = cnow;
978         }
979
980         current->state = TASK_RUNNING;
981         remove_wait_queue(&state->info->delta_msr_wait, &wait);
982
983         return ret;
984 }
985
986 /*
987  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
988  * Return: write counters to the user passed counter struct
989  * NB: both 1->0 and 0->1 transitions are counted except for
990  *     RI where only 0->1 is counted.
991  */
992 static int uart_get_count(struct uart_state *state,
993                           struct serial_icounter_struct __user *icnt)
994 {
995         struct serial_icounter_struct icount;
996         struct uart_icount cnow;
997         struct uart_port *port = state->port;
998
999         spin_lock_irq(&port->lock);
1000         memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
1001         spin_unlock_irq(&port->lock);
1002
1003         icount.cts         = cnow.cts;
1004         icount.dsr         = cnow.dsr;
1005         icount.rng         = cnow.rng;
1006         icount.dcd         = cnow.dcd;
1007         icount.rx          = cnow.rx;
1008         icount.tx          = cnow.tx;
1009         icount.frame       = cnow.frame;
1010         icount.overrun     = cnow.overrun;
1011         icount.parity      = cnow.parity;
1012         icount.brk         = cnow.brk;
1013         icount.buf_overrun = cnow.buf_overrun;
1014
1015         return copy_to_user(icnt, &icount, sizeof(icount)) ? -EFAULT : 0;
1016 }
1017
1018 /*
1019  * Called via sys_ioctl under the BKL.  We can use spin_lock_irq() here.
1020  */
1021 static int
1022 uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
1023            unsigned long arg)
1024 {
1025         struct uart_state *state = tty->driver_data;
1026         void __user *uarg = (void __user *)arg;
1027         int ret = -ENOIOCTLCMD;
1028
1029         BUG_ON(!kernel_locked());
1030
1031         /*
1032          * These ioctls don't rely on the hardware to be present.
1033          */
1034         switch (cmd) {
1035         case TIOCGSERIAL:
1036                 ret = uart_get_info(state, uarg);
1037                 break;
1038
1039         case TIOCSSERIAL:
1040                 ret = uart_set_info(state, uarg);
1041                 break;
1042
1043         case TIOCSERCONFIG:
1044                 ret = uart_do_autoconfig(state);
1045                 break;
1046
1047         case TIOCSERGWILD: /* obsolete */
1048         case TIOCSERSWILD: /* obsolete */
1049                 ret = 0;
1050                 break;
1051         }
1052
1053         if (ret != -ENOIOCTLCMD)
1054                 goto out;
1055
1056         if (tty->flags & (1 << TTY_IO_ERROR)) {
1057                 ret = -EIO;
1058                 goto out;
1059         }
1060
1061         /*
1062          * The following should only be used when hardware is present.
1063          */
1064         switch (cmd) {
1065         case TIOCMIWAIT:
1066                 ret = uart_wait_modem_status(state, arg);
1067                 break;
1068
1069         case TIOCGICOUNT:
1070                 ret = uart_get_count(state, uarg);
1071                 break;
1072         }
1073
1074         if (ret != -ENOIOCTLCMD)
1075                 goto out;
1076
1077         mutex_lock(&state->mutex);
1078
1079         if (tty_hung_up_p(filp)) {
1080                 ret = -EIO;
1081                 goto out_up;
1082         }
1083
1084         /*
1085          * All these rely on hardware being present and need to be
1086          * protected against the tty being hung up.
1087          */
1088         switch (cmd) {
1089         case TIOCSERGETLSR: /* Get line status register */
1090                 ret = uart_get_lsr_info(state, uarg);
1091                 break;
1092
1093         default: {
1094                 struct uart_port *port = state->port;
1095                 if (port->ops->ioctl)
1096                         ret = port->ops->ioctl(port, cmd, arg);
1097                 break;
1098         }
1099         }
1100  out_up:
1101         mutex_unlock(&state->mutex);
1102  out:
1103         return ret;
1104 }
1105
1106 static void uart_set_termios(struct tty_struct *tty, struct termios *old_termios)
1107 {
1108         struct uart_state *state = tty->driver_data;
1109         unsigned long flags;
1110         unsigned int cflag = tty->termios->c_cflag;
1111
1112         BUG_ON(!kernel_locked());
1113
1114         /*
1115          * These are the bits that are used to setup various
1116          * flags in the low level driver.
1117          */
1118 #define RELEVANT_IFLAG(iflag)   ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1119
1120         if ((cflag ^ old_termios->c_cflag) == 0 &&
1121             RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0)
1122                 return;
1123
1124         uart_change_speed(state, old_termios);
1125
1126         /* Handle transition to B0 status */
1127         if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1128                 uart_clear_mctrl(state->port, TIOCM_RTS | TIOCM_DTR);
1129
1130         /* Handle transition away from B0 status */
1131         if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1132                 unsigned int mask = TIOCM_DTR;
1133                 if (!(cflag & CRTSCTS) ||
1134                     !test_bit(TTY_THROTTLED, &tty->flags))
1135                         mask |= TIOCM_RTS;
1136                 uart_set_mctrl(state->port, mask);
1137         }
1138
1139         /* Handle turning off CRTSCTS */
1140         if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1141                 spin_lock_irqsave(&state->port->lock, flags);
1142                 tty->hw_stopped = 0;
1143                 __uart_start(tty);
1144                 spin_unlock_irqrestore(&state->port->lock, flags);
1145         }
1146
1147         /* Handle turning on CRTSCTS */
1148         if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1149                 spin_lock_irqsave(&state->port->lock, flags);
1150                 if (!(state->port->ops->get_mctrl(state->port) & TIOCM_CTS)) {
1151                         tty->hw_stopped = 1;
1152                         state->port->ops->stop_tx(state->port);
1153                 }
1154                 spin_unlock_irqrestore(&state->port->lock, flags);
1155         }
1156
1157 #if 0
1158         /*
1159          * No need to wake up processes in open wait, since they
1160          * sample the CLOCAL flag once, and don't recheck it.
1161          * XXX  It's not clear whether the current behavior is correct
1162          * or not.  Hence, this may change.....
1163          */
1164         if (!(old_termios->c_cflag & CLOCAL) &&
1165             (tty->termios->c_cflag & CLOCAL))
1166                 wake_up_interruptible(&state->info->open_wait);
1167 #endif
1168 }
1169
1170 /*
1171  * In 2.4.5, calls to this will be serialized via the BKL in
1172  *  linux/drivers/char/tty_io.c:tty_release()
1173  *  linux/drivers/char/tty_io.c:do_tty_handup()
1174  */
1175 static void uart_close(struct tty_struct *tty, struct file *filp)
1176 {
1177         struct uart_state *state = tty->driver_data;
1178         struct uart_port *port;
1179         
1180         BUG_ON(!kernel_locked());
1181
1182         if (!state || !state->port)
1183                 return;
1184
1185         port = state->port;
1186
1187         DPRINTK("uart_close(%d) called\n", port->line);
1188
1189         mutex_lock(&state->mutex);
1190
1191         if (tty_hung_up_p(filp))
1192                 goto done;
1193
1194         if ((tty->count == 1) && (state->count != 1)) {
1195                 /*
1196                  * Uh, oh.  tty->count is 1, which means that the tty
1197                  * structure will be freed.  state->count should always
1198                  * be one in these conditions.  If it's greater than
1199                  * one, we've got real problems, since it means the
1200                  * serial port won't be shutdown.
1201                  */
1202                 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1203                        "state->count is %d\n", state->count);
1204                 state->count = 1;
1205         }
1206         if (--state->count < 0) {
1207                 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1208                        tty->name, state->count);
1209                 state->count = 0;
1210         }
1211         if (state->count)
1212                 goto done;
1213
1214         /*
1215          * Now we wait for the transmit buffer to clear; and we notify
1216          * the line discipline to only process XON/XOFF characters by
1217          * setting tty->closing.
1218          */
1219         tty->closing = 1;
1220
1221         if (state->closing_wait != USF_CLOSING_WAIT_NONE)
1222                 tty_wait_until_sent(tty, msecs_to_jiffies(state->closing_wait));
1223
1224         /*
1225          * At this point, we stop accepting input.  To do this, we
1226          * disable the receive line status interrupts.
1227          */
1228         if (state->info->flags & UIF_INITIALIZED) {
1229                 unsigned long flags;
1230                 spin_lock_irqsave(&port->lock, flags);
1231                 port->ops->stop_rx(port);
1232                 spin_unlock_irqrestore(&port->lock, flags);
1233                 /*
1234                  * Before we drop DTR, make sure the UART transmitter
1235                  * has completely drained; this is especially
1236                  * important if there is a transmit FIFO!
1237                  */
1238                 uart_wait_until_sent(tty, port->timeout);
1239         }
1240
1241         uart_shutdown(state);
1242         uart_flush_buffer(tty);
1243
1244         tty_ldisc_flush(tty);   
1245         
1246         tty->closing = 0;
1247         state->info->tty = NULL;
1248
1249         if (state->info->blocked_open) {
1250                 if (state->close_delay)
1251                         msleep_interruptible(state->close_delay);
1252         } else if (!uart_console(port)) {
1253                 uart_change_pm(state, 3);
1254         }
1255
1256         /*
1257          * Wake up anyone trying to open this port.
1258          */
1259         state->info->flags &= ~UIF_NORMAL_ACTIVE;
1260         wake_up_interruptible(&state->info->open_wait);
1261
1262  done:
1263         mutex_unlock(&state->mutex);
1264 }
1265
1266 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1267 {
1268         struct uart_state *state = tty->driver_data;
1269         struct uart_port *port = state->port;
1270         unsigned long char_time, expire;
1271
1272         BUG_ON(!kernel_locked());
1273
1274         if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1275                 return;
1276
1277         /*
1278          * Set the check interval to be 1/5 of the estimated time to
1279          * send a single character, and make it at least 1.  The check
1280          * interval should also be less than the timeout.
1281          *
1282          * Note: we have to use pretty tight timings here to satisfy
1283          * the NIST-PCTS.
1284          */
1285         char_time = (port->timeout - HZ/50) / port->fifosize;
1286         char_time = char_time / 5;
1287         if (char_time == 0)
1288                 char_time = 1;
1289         if (timeout && timeout < char_time)
1290                 char_time = timeout;
1291
1292         /*
1293          * If the transmitter hasn't cleared in twice the approximate
1294          * amount of time to send the entire FIFO, it probably won't
1295          * ever clear.  This assumes the UART isn't doing flow
1296          * control, which is currently the case.  Hence, if it ever
1297          * takes longer than port->timeout, this is probably due to a
1298          * UART bug of some kind.  So, we clamp the timeout parameter at
1299          * 2*port->timeout.
1300          */
1301         if (timeout == 0 || timeout > 2 * port->timeout)
1302                 timeout = 2 * port->timeout;
1303
1304         expire = jiffies + timeout;
1305
1306         DPRINTK("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1307                 port->line, jiffies, expire);
1308
1309         /*
1310          * Check whether the transmitter is empty every 'char_time'.
1311          * 'timeout' / 'expire' give us the maximum amount of time
1312          * we wait.
1313          */
1314         while (!port->ops->tx_empty(port)) {
1315                 msleep_interruptible(jiffies_to_msecs(char_time));
1316                 if (signal_pending(current))
1317                         break;
1318                 if (time_after(jiffies, expire))
1319                         break;
1320         }
1321         set_current_state(TASK_RUNNING); /* might not be needed */
1322 }
1323
1324 /*
1325  * This is called with the BKL held in
1326  *  linux/drivers/char/tty_io.c:do_tty_hangup()
1327  * We're called from the eventd thread, so we can sleep for
1328  * a _short_ time only.
1329  */
1330 static void uart_hangup(struct tty_struct *tty)
1331 {
1332         struct uart_state *state = tty->driver_data;
1333
1334         BUG_ON(!kernel_locked());
1335         DPRINTK("uart_hangup(%d)\n", state->port->line);
1336
1337         mutex_lock(&state->mutex);
1338         if (state->info && state->info->flags & UIF_NORMAL_ACTIVE) {
1339                 uart_flush_buffer(tty);
1340                 uart_shutdown(state);
1341                 state->count = 0;
1342                 state->info->flags &= ~UIF_NORMAL_ACTIVE;
1343                 state->info->tty = NULL;
1344                 wake_up_interruptible(&state->info->open_wait);
1345                 wake_up_interruptible(&state->info->delta_msr_wait);
1346         }
1347         mutex_unlock(&state->mutex);
1348 }
1349
1350 /*
1351  * Copy across the serial console cflag setting into the termios settings
1352  * for the initial open of the port.  This allows continuity between the
1353  * kernel settings, and the settings init adopts when it opens the port
1354  * for the first time.
1355  */
1356 static void uart_update_termios(struct uart_state *state)
1357 {
1358         struct tty_struct *tty = state->info->tty;
1359         struct uart_port *port = state->port;
1360
1361         if (uart_console(port) && port->cons->cflag) {
1362                 tty->termios->c_cflag = port->cons->cflag;
1363                 port->cons->cflag = 0;
1364         }
1365
1366         /*
1367          * If the device failed to grab its irq resources,
1368          * or some other error occurred, don't try to talk
1369          * to the port hardware.
1370          */
1371         if (!(tty->flags & (1 << TTY_IO_ERROR))) {
1372                 /*
1373                  * Make termios settings take effect.
1374                  */
1375                 uart_change_speed(state, NULL);
1376
1377                 /*
1378                  * And finally enable the RTS and DTR signals.
1379                  */
1380                 if (tty->termios->c_cflag & CBAUD)
1381                         uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
1382         }
1383 }
1384
1385 /*
1386  * Block the open until the port is ready.  We must be called with
1387  * the per-port semaphore held.
1388  */
1389 static int
1390 uart_block_til_ready(struct file *filp, struct uart_state *state)
1391 {
1392         DECLARE_WAITQUEUE(wait, current);
1393         struct uart_info *info = state->info;
1394         struct uart_port *port = state->port;
1395         unsigned int mctrl;
1396
1397         info->blocked_open++;
1398         state->count--;
1399
1400         add_wait_queue(&info->open_wait, &wait);
1401         while (1) {
1402                 set_current_state(TASK_INTERRUPTIBLE);
1403
1404                 /*
1405                  * If we have been hung up, tell userspace/restart open.
1406                  */
1407                 if (tty_hung_up_p(filp) || info->tty == NULL)
1408                         break;
1409
1410                 /*
1411                  * If the port has been closed, tell userspace/restart open.
1412                  */
1413                 if (!(info->flags & UIF_INITIALIZED))
1414                         break;
1415
1416                 /*
1417                  * If non-blocking mode is set, or CLOCAL mode is set,
1418                  * we don't want to wait for the modem status lines to
1419                  * indicate that the port is ready.
1420                  *
1421                  * Also, if the port is not enabled/configured, we want
1422                  * to allow the open to succeed here.  Note that we will
1423                  * have set TTY_IO_ERROR for a non-existant port.
1424                  */
1425                 if ((filp->f_flags & O_NONBLOCK) ||
1426                     (info->tty->termios->c_cflag & CLOCAL) ||
1427                     (info->tty->flags & (1 << TTY_IO_ERROR))) {
1428                         break;
1429                 }
1430
1431                 /*
1432                  * Set DTR to allow modem to know we're waiting.  Do
1433                  * not set RTS here - we want to make sure we catch
1434                  * the data from the modem.
1435                  */
1436                 if (info->tty->termios->c_cflag & CBAUD)
1437                         uart_set_mctrl(port, TIOCM_DTR);
1438
1439                 /*
1440                  * and wait for the carrier to indicate that the
1441                  * modem is ready for us.
1442                  */
1443                 spin_lock_irq(&port->lock);
1444                 port->ops->enable_ms(port);
1445                 mctrl = port->ops->get_mctrl(port);
1446                 spin_unlock_irq(&port->lock);
1447                 if (mctrl & TIOCM_CAR)
1448                         break;
1449
1450                 mutex_unlock(&state->mutex);
1451                 schedule();
1452                 mutex_lock(&state->mutex);
1453
1454                 if (signal_pending(current))
1455                         break;
1456         }
1457         set_current_state(TASK_RUNNING);
1458         remove_wait_queue(&info->open_wait, &wait);
1459
1460         state->count++;
1461         info->blocked_open--;
1462
1463         if (signal_pending(current))
1464                 return -ERESTARTSYS;
1465
1466         if (!info->tty || tty_hung_up_p(filp))
1467                 return -EAGAIN;
1468
1469         return 0;
1470 }
1471
1472 static struct uart_state *uart_get(struct uart_driver *drv, int line)
1473 {
1474         struct uart_state *state;
1475
1476         mutex_lock(&port_mutex);
1477         state = drv->state + line;
1478         if (mutex_lock_interruptible(&state->mutex)) {
1479                 state = ERR_PTR(-ERESTARTSYS);
1480                 goto out;
1481         }
1482
1483         state->count++;
1484         if (!state->port) {
1485                 state->count--;
1486                 mutex_unlock(&state->mutex);
1487                 state = ERR_PTR(-ENXIO);
1488                 goto out;
1489         }
1490
1491         if (!state->info) {
1492                 state->info = kmalloc(sizeof(struct uart_info), GFP_KERNEL);
1493                 if (state->info) {
1494                         memset(state->info, 0, sizeof(struct uart_info));
1495                         init_waitqueue_head(&state->info->open_wait);
1496                         init_waitqueue_head(&state->info->delta_msr_wait);
1497
1498                         /*
1499                          * Link the info into the other structures.
1500                          */
1501                         state->port->info = state->info;
1502
1503                         tasklet_init(&state->info->tlet, uart_tasklet_action,
1504                                      (unsigned long)state);
1505                 } else {
1506                         state->count--;
1507                         mutex_unlock(&state->mutex);
1508                         state = ERR_PTR(-ENOMEM);
1509                 }
1510         }
1511
1512  out:
1513         mutex_unlock(&port_mutex);
1514         return state;
1515 }
1516
1517 /*
1518  * In 2.4.5, calls to uart_open are serialised by the BKL in
1519  *   linux/fs/devices.c:chrdev_open()
1520  * Note that if this fails, then uart_close() _will_ be called.
1521  *
1522  * In time, we want to scrap the "opening nonpresent ports"
1523  * behaviour and implement an alternative way for setserial
1524  * to set base addresses/ports/types.  This will allow us to
1525  * get rid of a certain amount of extra tests.
1526  */
1527 static int uart_open(struct tty_struct *tty, struct file *filp)
1528 {
1529         struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1530         struct uart_state *state;
1531         int retval, line = tty->index;
1532
1533         BUG_ON(!kernel_locked());
1534         DPRINTK("uart_open(%d) called\n", line);
1535
1536         /*
1537          * tty->driver->num won't change, so we won't fail here with
1538          * tty->driver_data set to something non-NULL (and therefore
1539          * we won't get caught by uart_close()).
1540          */
1541         retval = -ENODEV;
1542         if (line >= tty->driver->num)
1543                 goto fail;
1544
1545         /*
1546          * We take the semaphore inside uart_get to guarantee that we won't
1547          * be re-entered while allocating the info structure, or while we
1548          * request any IRQs that the driver may need.  This also has the nice
1549          * side-effect that it delays the action of uart_hangup, so we can
1550          * guarantee that info->tty will always contain something reasonable.
1551          */
1552         state = uart_get(drv, line);
1553         if (IS_ERR(state)) {
1554                 retval = PTR_ERR(state);
1555                 goto fail;
1556         }
1557
1558         /*
1559          * Once we set tty->driver_data here, we are guaranteed that
1560          * uart_close() will decrement the driver module use count.
1561          * Any failures from here onwards should not touch the count.
1562          */
1563         tty->driver_data = state;
1564         tty->low_latency = (state->port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1565         tty->alt_speed = 0;
1566         state->info->tty = tty;
1567
1568         /*
1569          * If the port is in the middle of closing, bail out now.
1570          */
1571         if (tty_hung_up_p(filp)) {
1572                 retval = -EAGAIN;
1573                 state->count--;
1574                 mutex_unlock(&state->mutex);
1575                 goto fail;
1576         }
1577
1578         /*
1579          * Make sure the device is in D0 state.
1580          */
1581         if (state->count == 1)
1582                 uart_change_pm(state, 0);
1583
1584         /*
1585          * Start up the serial port.
1586          */
1587         retval = uart_startup(state, 0);
1588
1589         /*
1590          * If we succeeded, wait until the port is ready.
1591          */
1592         if (retval == 0)
1593                 retval = uart_block_til_ready(filp, state);
1594         mutex_unlock(&state->mutex);
1595
1596         /*
1597          * If this is the first open to succeed, adjust things to suit.
1598          */
1599         if (retval == 0 && !(state->info->flags & UIF_NORMAL_ACTIVE)) {
1600                 state->info->flags |= UIF_NORMAL_ACTIVE;
1601
1602                 uart_update_termios(state);
1603         }
1604
1605  fail:
1606         return retval;
1607 }
1608
1609 static const char *uart_type(struct uart_port *port)
1610 {
1611         const char *str = NULL;
1612
1613         if (port->ops->type)
1614                 str = port->ops->type(port);
1615
1616         if (!str)
1617                 str = "unknown";
1618
1619         return str;
1620 }
1621
1622 #ifdef CONFIG_PROC_FS
1623
1624 static int uart_line_info(char *buf, struct uart_driver *drv, int i)
1625 {
1626         struct uart_state *state = drv->state + i;
1627         struct uart_port *port = state->port;
1628         char stat_buf[32];
1629         unsigned int status;
1630         int ret;
1631
1632         if (!port)
1633                 return 0;
1634
1635         ret = sprintf(buf, "%d: uart:%s %s%08lX irq:%d",
1636                         port->line, uart_type(port),
1637                         port->iotype == UPIO_MEM ? "mmio:0x" : "port:",
1638                         port->iotype == UPIO_MEM ? port->mapbase :
1639                                                 (unsigned long) port->iobase,
1640                         port->irq);
1641
1642         if (port->type == PORT_UNKNOWN) {
1643                 strcat(buf, "\n");
1644                 return ret + 1;
1645         }
1646
1647         if(capable(CAP_SYS_ADMIN))
1648         {
1649                 spin_lock_irq(&port->lock);
1650                 status = port->ops->get_mctrl(port);
1651                 spin_unlock_irq(&port->lock);
1652
1653                 ret += sprintf(buf + ret, " tx:%d rx:%d",
1654                                 port->icount.tx, port->icount.rx);
1655                 if (port->icount.frame)
1656                         ret += sprintf(buf + ret, " fe:%d",
1657                                 port->icount.frame);
1658                 if (port->icount.parity)
1659                         ret += sprintf(buf + ret, " pe:%d",
1660                                 port->icount.parity);
1661                 if (port->icount.brk)
1662                         ret += sprintf(buf + ret, " brk:%d",
1663                                 port->icount.brk);
1664                 if (port->icount.overrun)
1665                         ret += sprintf(buf + ret, " oe:%d",
1666                                 port->icount.overrun);
1667         
1668 #define INFOBIT(bit,str) \
1669         if (port->mctrl & (bit)) \
1670                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1671                         strlen(stat_buf) - 2)
1672 #define STATBIT(bit,str) \
1673         if (status & (bit)) \
1674                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1675                        strlen(stat_buf) - 2)
1676
1677                 stat_buf[0] = '\0';
1678                 stat_buf[1] = '\0';
1679                 INFOBIT(TIOCM_RTS, "|RTS");
1680                 STATBIT(TIOCM_CTS, "|CTS");
1681                 INFOBIT(TIOCM_DTR, "|DTR");
1682                 STATBIT(TIOCM_DSR, "|DSR");
1683                 STATBIT(TIOCM_CAR, "|CD");
1684                 STATBIT(TIOCM_RNG, "|RI");
1685                 if (stat_buf[0])
1686                         stat_buf[0] = ' ';
1687                 strcat(stat_buf, "\n");
1688         
1689                 ret += sprintf(buf + ret, stat_buf);
1690         } else {
1691                 strcat(buf, "\n");
1692                 ret++;
1693         }
1694 #undef STATBIT
1695 #undef INFOBIT
1696         return ret;
1697 }
1698
1699 static int uart_read_proc(char *page, char **start, off_t off,
1700                           int count, int *eof, void *data)
1701 {
1702         struct tty_driver *ttydrv = data;
1703         struct uart_driver *drv = ttydrv->driver_state;
1704         int i, len = 0, l;
1705         off_t begin = 0;
1706
1707         len += sprintf(page, "serinfo:1.0 driver%s%s revision:%s\n",
1708                         "", "", "");
1709         for (i = 0; i < drv->nr && len < PAGE_SIZE - 96; i++) {
1710                 l = uart_line_info(page + len, drv, i);
1711                 len += l;
1712                 if (len + begin > off + count)
1713                         goto done;
1714                 if (len + begin < off) {
1715                         begin += len;
1716                         len = 0;
1717                 }
1718         }
1719         *eof = 1;
1720  done:
1721         if (off >= len + begin)
1722                 return 0;
1723         *start = page + (off - begin);
1724         return (count < begin + len - off) ? count : (begin + len - off);
1725 }
1726 #endif
1727
1728 #ifdef CONFIG_SERIAL_CORE_CONSOLE
1729 /*
1730  *      Check whether an invalid uart number has been specified, and
1731  *      if so, search for the first available port that does have
1732  *      console support.
1733  */
1734 struct uart_port * __init
1735 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1736 {
1737         int idx = co->index;
1738
1739         if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1740                                      ports[idx].membase == NULL))
1741                 for (idx = 0; idx < nr; idx++)
1742                         if (ports[idx].iobase != 0 ||
1743                             ports[idx].membase != NULL)
1744                                 break;
1745
1746         co->index = idx;
1747
1748         return ports + idx;
1749 }
1750
1751 /**
1752  *      uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1753  *      @options: pointer to option string
1754  *      @baud: pointer to an 'int' variable for the baud rate.
1755  *      @parity: pointer to an 'int' variable for the parity.
1756  *      @bits: pointer to an 'int' variable for the number of data bits.
1757  *      @flow: pointer to an 'int' variable for the flow control character.
1758  *
1759  *      uart_parse_options decodes a string containing the serial console
1760  *      options.  The format of the string is <baud><parity><bits><flow>,
1761  *      eg: 115200n8r
1762  */
1763 void __init
1764 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1765 {
1766         char *s = options;
1767
1768         *baud = simple_strtoul(s, NULL, 10);
1769         while (*s >= '0' && *s <= '9')
1770                 s++;
1771         if (*s)
1772                 *parity = *s++;
1773         if (*s)
1774                 *bits = *s++ - '0';
1775         if (*s)
1776                 *flow = *s;
1777 }
1778
1779 struct baud_rates {
1780         unsigned int rate;
1781         unsigned int cflag;
1782 };
1783
1784 static const struct baud_rates baud_rates[] = {
1785         { 921600, B921600 },
1786         { 460800, B460800 },
1787         { 230400, B230400 },
1788         { 115200, B115200 },
1789         {  57600, B57600  },
1790         {  38400, B38400  },
1791         {  19200, B19200  },
1792         {   9600, B9600   },
1793         {   4800, B4800   },
1794         {   2400, B2400   },
1795         {   1200, B1200   },
1796         {      0, B38400  }
1797 };
1798
1799 /**
1800  *      uart_set_options - setup the serial console parameters
1801  *      @port: pointer to the serial ports uart_port structure
1802  *      @co: console pointer
1803  *      @baud: baud rate
1804  *      @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1805  *      @bits: number of data bits
1806  *      @flow: flow control character - 'r' (rts)
1807  */
1808 int __init
1809 uart_set_options(struct uart_port *port, struct console *co,
1810                  int baud, int parity, int bits, int flow)
1811 {
1812         struct termios termios;
1813         int i;
1814
1815         /*
1816          * Ensure that the serial console lock is initialised
1817          * early.
1818          */
1819         spin_lock_init(&port->lock);
1820
1821         memset(&termios, 0, sizeof(struct termios));
1822
1823         termios.c_cflag = CREAD | HUPCL | CLOCAL;
1824
1825         /*
1826          * Construct a cflag setting.
1827          */
1828         for (i = 0; baud_rates[i].rate; i++)
1829                 if (baud_rates[i].rate <= baud)
1830                         break;
1831
1832         termios.c_cflag |= baud_rates[i].cflag;
1833
1834         if (bits == 7)
1835                 termios.c_cflag |= CS7;
1836         else
1837                 termios.c_cflag |= CS8;
1838
1839         switch (parity) {
1840         case 'o': case 'O':
1841                 termios.c_cflag |= PARODD;
1842                 /*fall through*/
1843         case 'e': case 'E':
1844                 termios.c_cflag |= PARENB;
1845                 break;
1846         }
1847
1848         if (flow == 'r')
1849                 termios.c_cflag |= CRTSCTS;
1850
1851         port->ops->set_termios(port, &termios, NULL);
1852         co->cflag = termios.c_cflag;
1853
1854         return 0;
1855 }
1856 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1857
1858 static void uart_change_pm(struct uart_state *state, int pm_state)
1859 {
1860         struct uart_port *port = state->port;
1861         if (port->ops->pm)
1862                 port->ops->pm(port, pm_state, state->pm_state);
1863         state->pm_state = pm_state;
1864 }
1865
1866 int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
1867 {
1868         struct uart_state *state = drv->state + port->line;
1869
1870         mutex_lock(&state->mutex);
1871
1872         if (state->info && state->info->flags & UIF_INITIALIZED) {
1873                 struct uart_ops *ops = port->ops;
1874
1875                 spin_lock_irq(&port->lock);
1876                 ops->stop_tx(port);
1877                 ops->set_mctrl(port, 0);
1878                 ops->stop_rx(port);
1879                 spin_unlock_irq(&port->lock);
1880
1881                 /*
1882                  * Wait for the transmitter to empty.
1883                  */
1884                 while (!ops->tx_empty(port)) {
1885                         msleep(10);
1886                 }
1887
1888                 ops->shutdown(port);
1889         }
1890
1891         /*
1892          * Disable the console device before suspending.
1893          */
1894         if (uart_console(port))
1895                 console_stop(port->cons);
1896
1897         uart_change_pm(state, 3);
1898
1899         mutex_unlock(&state->mutex);
1900
1901         return 0;
1902 }
1903
1904 int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
1905 {
1906         struct uart_state *state = drv->state + port->line;
1907
1908         mutex_lock(&state->mutex);
1909
1910         uart_change_pm(state, 0);
1911
1912         /*
1913          * Re-enable the console device after suspending.
1914          */
1915         if (uart_console(port)) {
1916                 struct termios termios;
1917
1918                 /*
1919                  * First try to use the console cflag setting.
1920                  */
1921                 memset(&termios, 0, sizeof(struct termios));
1922                 termios.c_cflag = port->cons->cflag;
1923
1924                 /*
1925                  * If that's unset, use the tty termios setting.
1926                  */
1927                 if (state->info && state->info->tty && termios.c_cflag == 0)
1928                         termios = *state->info->tty->termios;
1929
1930                 port->ops->set_termios(port, &termios, NULL);
1931                 console_start(port->cons);
1932         }
1933
1934         if (state->info && state->info->flags & UIF_INITIALIZED) {
1935                 struct uart_ops *ops = port->ops;
1936                 int ret;
1937
1938                 ops->set_mctrl(port, 0);
1939                 ret = ops->startup(port);
1940                 if (ret == 0) {
1941                         uart_change_speed(state, NULL);
1942                         spin_lock_irq(&port->lock);
1943                         ops->set_mctrl(port, port->mctrl);
1944                         ops->start_tx(port);
1945                         spin_unlock_irq(&port->lock);
1946                 } else {
1947                         /*
1948                          * Failed to resume - maybe hardware went away?
1949                          * Clear the "initialized" flag so we won't try
1950                          * to call the low level drivers shutdown method.
1951                          */
1952                         state->info->flags &= ~UIF_INITIALIZED;
1953                         uart_shutdown(state);
1954                 }
1955         }
1956
1957         mutex_unlock(&state->mutex);
1958
1959         return 0;
1960 }
1961
1962 static inline void
1963 uart_report_port(struct uart_driver *drv, struct uart_port *port)
1964 {
1965         char address[64];
1966
1967         switch (port->iotype) {
1968         case UPIO_PORT:
1969                 snprintf(address, sizeof(address),
1970                          "I/O 0x%x", port->iobase);
1971                 break;
1972         case UPIO_HUB6:
1973                 snprintf(address, sizeof(address),
1974                          "I/O 0x%x offset 0x%x", port->iobase, port->hub6);
1975                 break;
1976         case UPIO_MEM:
1977         case UPIO_MEM32:
1978         case UPIO_AU:
1979                 snprintf(address, sizeof(address),
1980                          "MMIO 0x%lx", port->mapbase);
1981                 break;
1982         default:
1983                 strlcpy(address, "*unknown*", sizeof(address));
1984                 break;
1985         }
1986
1987         printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
1988                port->dev ? port->dev->bus_id : "",
1989                port->dev ? ": " : "",
1990                drv->dev_name, port->line, address, port->irq, uart_type(port));
1991 }
1992
1993 static void
1994 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
1995                     struct uart_port *port)
1996 {
1997         unsigned int flags;
1998
1999         /*
2000          * If there isn't a port here, don't do anything further.
2001          */
2002         if (!port->iobase && !port->mapbase && !port->membase)
2003                 return;
2004
2005         /*
2006          * Now do the auto configuration stuff.  Note that config_port
2007          * is expected to claim the resources and map the port for us.
2008          */
2009         flags = UART_CONFIG_TYPE;
2010         if (port->flags & UPF_AUTO_IRQ)
2011                 flags |= UART_CONFIG_IRQ;
2012         if (port->flags & UPF_BOOT_AUTOCONF) {
2013                 port->type = PORT_UNKNOWN;
2014                 port->ops->config_port(port, flags);
2015         }
2016
2017         if (port->type != PORT_UNKNOWN) {
2018                 unsigned long flags;
2019
2020                 uart_report_port(drv, port);
2021
2022                 /*
2023                  * Ensure that the modem control lines are de-activated.
2024                  * We probably don't need a spinlock around this, but
2025                  */
2026                 spin_lock_irqsave(&port->lock, flags);
2027                 port->ops->set_mctrl(port, 0);
2028                 spin_unlock_irqrestore(&port->lock, flags);
2029
2030                 /*
2031                  * Power down all ports by default, except the
2032                  * console if we have one.
2033                  */
2034                 if (!uart_console(port))
2035                         uart_change_pm(state, 3);
2036         }
2037 }
2038
2039 /*
2040  * This reverses the effects of uart_configure_port, hanging up the
2041  * port before removal.
2042  */
2043 static void
2044 uart_unconfigure_port(struct uart_driver *drv, struct uart_state *state)
2045 {
2046         struct uart_port *port = state->port;
2047         struct uart_info *info = state->info;
2048
2049         if (info && info->tty)
2050                 tty_vhangup(info->tty);
2051
2052         mutex_lock(&state->mutex);
2053
2054         state->info = NULL;
2055
2056         /*
2057          * Free the port IO and memory resources, if any.
2058          */
2059         if (port->type != PORT_UNKNOWN)
2060                 port->ops->release_port(port);
2061
2062         /*
2063          * Indicate that there isn't a port here anymore.
2064          */
2065         port->type = PORT_UNKNOWN;
2066
2067         /*
2068          * Kill the tasklet, and free resources.
2069          */
2070         if (info) {
2071                 tasklet_kill(&info->tlet);
2072                 kfree(info);
2073         }
2074
2075         mutex_unlock(&state->mutex);
2076 }
2077
2078 static struct tty_operations uart_ops = {
2079         .open           = uart_open,
2080         .close          = uart_close,
2081         .write          = uart_write,
2082         .put_char       = uart_put_char,
2083         .flush_chars    = uart_flush_chars,
2084         .write_room     = uart_write_room,
2085         .chars_in_buffer= uart_chars_in_buffer,
2086         .flush_buffer   = uart_flush_buffer,
2087         .ioctl          = uart_ioctl,
2088         .throttle       = uart_throttle,
2089         .unthrottle     = uart_unthrottle,
2090         .send_xchar     = uart_send_xchar,
2091         .set_termios    = uart_set_termios,
2092         .stop           = uart_stop,
2093         .start          = uart_start,
2094         .hangup         = uart_hangup,
2095         .break_ctl      = uart_break_ctl,
2096         .wait_until_sent= uart_wait_until_sent,
2097 #ifdef CONFIG_PROC_FS
2098         .read_proc      = uart_read_proc,
2099 #endif
2100         .tiocmget       = uart_tiocmget,
2101         .tiocmset       = uart_tiocmset,
2102 };
2103
2104 /**
2105  *      uart_register_driver - register a driver with the uart core layer
2106  *      @drv: low level driver structure
2107  *
2108  *      Register a uart driver with the core driver.  We in turn register
2109  *      with the tty layer, and initialise the core driver per-port state.
2110  *
2111  *      We have a proc file in /proc/tty/driver which is named after the
2112  *      normal driver.
2113  *
2114  *      drv->port should be NULL, and the per-port structures should be
2115  *      registered using uart_add_one_port after this call has succeeded.
2116  */
2117 int uart_register_driver(struct uart_driver *drv)
2118 {
2119         struct tty_driver *normal = NULL;
2120         int i, retval;
2121
2122         BUG_ON(drv->state);
2123
2124         /*
2125          * Maybe we should be using a slab cache for this, especially if
2126          * we have a large number of ports to handle.
2127          */
2128         drv->state = kmalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2129         retval = -ENOMEM;
2130         if (!drv->state)
2131                 goto out;
2132
2133         memset(drv->state, 0, sizeof(struct uart_state) * drv->nr);
2134
2135         normal  = alloc_tty_driver(drv->nr);
2136         if (!normal)
2137                 goto out;
2138
2139         drv->tty_driver = normal;
2140
2141         normal->owner           = drv->owner;
2142         normal->driver_name     = drv->driver_name;
2143         normal->devfs_name      = drv->devfs_name;
2144         normal->name            = drv->dev_name;
2145         normal->major           = drv->major;
2146         normal->minor_start     = drv->minor;
2147         normal->type            = TTY_DRIVER_TYPE_SERIAL;
2148         normal->subtype         = SERIAL_TYPE_NORMAL;
2149         normal->init_termios    = tty_std_termios;
2150         normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2151         normal->flags           = TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS;
2152         normal->driver_state    = drv;
2153         tty_set_operations(normal, &uart_ops);
2154
2155         /*
2156          * Initialise the UART state(s).
2157          */
2158         for (i = 0; i < drv->nr; i++) {
2159                 struct uart_state *state = drv->state + i;
2160
2161                 state->close_delay     = 500;   /* .5 seconds */
2162                 state->closing_wait    = 30000; /* 30 seconds */
2163
2164                 mutex_init(&state->mutex);
2165         }
2166
2167         retval = tty_register_driver(normal);
2168  out:
2169         if (retval < 0) {
2170                 put_tty_driver(normal);
2171                 kfree(drv->state);
2172         }
2173         return retval;
2174 }
2175
2176 /**
2177  *      uart_unregister_driver - remove a driver from the uart core layer
2178  *      @drv: low level driver structure
2179  *
2180  *      Remove all references to a driver from the core driver.  The low
2181  *      level driver must have removed all its ports via the
2182  *      uart_remove_one_port() if it registered them with uart_add_one_port().
2183  *      (ie, drv->port == NULL)
2184  */
2185 void uart_unregister_driver(struct uart_driver *drv)
2186 {
2187         struct tty_driver *p = drv->tty_driver;
2188         tty_unregister_driver(p);
2189         put_tty_driver(p);
2190         kfree(drv->state);
2191         drv->tty_driver = NULL;
2192 }
2193
2194 struct tty_driver *uart_console_device(struct console *co, int *index)
2195 {
2196         struct uart_driver *p = co->data;
2197         *index = co->index;
2198         return p->tty_driver;
2199 }
2200
2201 /**
2202  *      uart_add_one_port - attach a driver-defined port structure
2203  *      @drv: pointer to the uart low level driver structure for this port
2204  *      @port: uart port structure to use for this port.
2205  *
2206  *      This allows the driver to register its own uart_port structure
2207  *      with the core driver.  The main purpose is to allow the low
2208  *      level uart drivers to expand uart_port, rather than having yet
2209  *      more levels of structures.
2210  */
2211 int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
2212 {
2213         struct uart_state *state;
2214         int ret = 0;
2215
2216         BUG_ON(in_interrupt());
2217
2218         if (port->line >= drv->nr)
2219                 return -EINVAL;
2220
2221         state = drv->state + port->line;
2222
2223         mutex_lock(&port_mutex);
2224         if (state->port) {
2225                 ret = -EINVAL;
2226                 goto out;
2227         }
2228
2229         state->port = port;
2230
2231         port->cons = drv->cons;
2232         port->info = state->info;
2233
2234         /*
2235          * If this port is a console, then the spinlock is already
2236          * initialised.
2237          */
2238         if (!uart_console(port))
2239                 spin_lock_init(&port->lock);
2240
2241         uart_configure_port(drv, state, port);
2242
2243         /*
2244          * Register the port whether it's detected or not.  This allows
2245          * setserial to be used to alter this ports parameters.
2246          */
2247         tty_register_device(drv->tty_driver, port->line, port->dev);
2248
2249         /*
2250          * If this driver supports console, and it hasn't been
2251          * successfully registered yet, try to re-register it.
2252          * It may be that the port was not available.
2253          */
2254         if (port->type != PORT_UNKNOWN &&
2255             port->cons && !(port->cons->flags & CON_ENABLED))
2256                 register_console(port->cons);
2257
2258  out:
2259         mutex_unlock(&port_mutex);
2260
2261         return ret;
2262 }
2263
2264 /**
2265  *      uart_remove_one_port - detach a driver defined port structure
2266  *      @drv: pointer to the uart low level driver structure for this port
2267  *      @port: uart port structure for this port
2268  *
2269  *      This unhooks (and hangs up) the specified port structure from the
2270  *      core driver.  No further calls will be made to the low-level code
2271  *      for this port.
2272  */
2273 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
2274 {
2275         struct uart_state *state = drv->state + port->line;
2276
2277         BUG_ON(in_interrupt());
2278
2279         if (state->port != port)
2280                 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2281                         state->port, port);
2282
2283         mutex_lock(&port_mutex);
2284
2285         /*
2286          * Remove the devices from devfs
2287          */
2288         tty_unregister_device(drv->tty_driver, port->line);
2289
2290         uart_unconfigure_port(drv, state);
2291         state->port = NULL;
2292         mutex_unlock(&port_mutex);
2293
2294         return 0;
2295 }
2296
2297 /*
2298  *      Are the two ports equivalent?
2299  */
2300 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2301 {
2302         if (port1->iotype != port2->iotype)
2303                 return 0;
2304
2305         switch (port1->iotype) {
2306         case UPIO_PORT:
2307                 return (port1->iobase == port2->iobase);
2308         case UPIO_HUB6:
2309                 return (port1->iobase == port2->iobase) &&
2310                        (port1->hub6   == port2->hub6);
2311         case UPIO_MEM:
2312                 return (port1->mapbase == port2->mapbase);
2313         }
2314         return 0;
2315 }
2316 EXPORT_SYMBOL(uart_match_port);
2317
2318 EXPORT_SYMBOL(uart_write_wakeup);
2319 EXPORT_SYMBOL(uart_register_driver);
2320 EXPORT_SYMBOL(uart_unregister_driver);
2321 EXPORT_SYMBOL(uart_suspend_port);
2322 EXPORT_SYMBOL(uart_resume_port);
2323 EXPORT_SYMBOL(uart_add_one_port);
2324 EXPORT_SYMBOL(uart_remove_one_port);
2325
2326 MODULE_DESCRIPTION("Serial driver core");
2327 MODULE_LICENSE("GPL");