Revert "Merge commit 'main-jb-2012.08.03-B4' into t114-0806"
[linux-2.6.git] / drivers / tty / serial / serial_core.c
1 /*
2  *  Driver core for serial ports
3  *
4  *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
5  *
6  *  Copyright 1999 ARM Limited
7  *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
22  */
23 #include <linux/module.h>
24 #include <linux/tty.h>
25 #include <linux/tty_flip.h>
26 #include <linux/slab.h>
27 #include <linux/init.h>
28 #include <linux/console.h>
29 #include <linux/proc_fs.h>
30 #include <linux/seq_file.h>
31 #include <linux/device.h>
32 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
33 #include <linux/serial_core.h>
34 #include <linux/delay.h>
35 #include <linux/mutex.h>
36
37 #include <asm/irq.h>
38 #include <asm/uaccess.h>
39
40 /*
41  * This is used to lock changes in serial line configuration.
42  */
43 static DEFINE_MUTEX(port_mutex);
44
45 /*
46  * lockdep: port->lock is initialized in two places, but we
47  *          want only one lock-class:
48  */
49 static struct lock_class_key port_lock_key;
50
51 #define HIGH_BITS_OFFSET        ((sizeof(long)-sizeof(int))*8)
52
53 #ifdef CONFIG_SERIAL_CORE_CONSOLE
54 #define uart_console(port)      ((port)->cons && (port)->cons->index == (port)->line)
55 #else
56 #define uart_console(port)      (0)
57 #endif
58
59 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
60                                         struct ktermios *old_termios);
61 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
62 static void uart_change_pm(struct uart_state *state, int pm_state);
63
64 static void uart_port_shutdown(struct tty_port *port);
65
66 /*
67  * This routine is used by the interrupt handler to schedule processing in
68  * the software interrupt portion of the driver.
69  */
70 void uart_write_wakeup(struct uart_port *port)
71 {
72         struct uart_state *state = port->state;
73         /*
74          * This means you called this function _after_ the port was
75          * closed.  No cookie for you.
76          */
77         BUG_ON(!state);
78         tty_wakeup(state->port.tty);
79 }
80
81 static void uart_stop(struct tty_struct *tty)
82 {
83         struct uart_state *state = tty->driver_data;
84         struct uart_port *port = state->uart_port;
85         unsigned long flags;
86
87         spin_lock_irqsave(&port->lock, flags);
88         port->ops->stop_tx(port);
89         spin_unlock_irqrestore(&port->lock, flags);
90 }
91
92 static void __uart_start(struct tty_struct *tty)
93 {
94         struct uart_state *state = tty->driver_data;
95         struct uart_port *port = state->uart_port;
96
97         if (port->ops->wake_peer)
98                 port->ops->wake_peer(port);
99
100         if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
101             !tty->stopped && !tty->hw_stopped)
102                 port->ops->start_tx(port);
103 }
104
105 static void uart_start(struct tty_struct *tty)
106 {
107         struct uart_state *state = tty->driver_data;
108         struct uart_port *port = state->uart_port;
109         unsigned long flags;
110
111         spin_lock_irqsave(&port->lock, flags);
112         __uart_start(tty);
113         spin_unlock_irqrestore(&port->lock, flags);
114 }
115
116 static inline void
117 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
118 {
119         unsigned long flags;
120         unsigned int old;
121
122         spin_lock_irqsave(&port->lock, flags);
123         old = port->mctrl;
124         port->mctrl = (old & ~clear) | set;
125         if (old != port->mctrl)
126                 port->ops->set_mctrl(port, port->mctrl);
127         spin_unlock_irqrestore(&port->lock, flags);
128 }
129
130 #define uart_set_mctrl(port, set)       uart_update_mctrl(port, set, 0)
131 #define uart_clear_mctrl(port, clear)   uart_update_mctrl(port, 0, clear)
132
133 /*
134  * Startup the port.  This will be called once per open.  All calls
135  * will be serialised by the per-port mutex.
136  */
137 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
138                 int init_hw)
139 {
140         struct uart_port *uport = state->uart_port;
141         struct tty_port *port = &state->port;
142         unsigned long page;
143         int retval = 0;
144
145         if (uport->type == PORT_UNKNOWN)
146                 return 1;
147
148         /*
149          * Initialise and allocate the transmit and temporary
150          * buffer.
151          */
152         if (!state->xmit.buf) {
153                 /* This is protected by the per port mutex */
154                 page = get_zeroed_page(GFP_KERNEL);
155                 if (!page)
156                         return -ENOMEM;
157
158                 state->xmit.buf = (unsigned char *) page;
159                 uart_circ_clear(&state->xmit);
160         }
161
162         retval = uport->ops->startup(uport);
163         if (retval == 0) {
164                 if (uart_console(uport) && uport->cons->cflag) {
165                         tty->termios->c_cflag = uport->cons->cflag;
166                         uport->cons->cflag = 0;
167                 }
168                 /*
169                  * Initialise the hardware port settings.
170                  */
171                 uart_change_speed(tty, state, NULL);
172
173                 if (init_hw) {
174                         /*
175                          * Setup the RTS and DTR signals once the
176                          * port is open and ready to respond.
177                          */
178                         if (tty->termios->c_cflag & CBAUD)
179                                 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
180                 }
181
182                 if (port->flags & ASYNC_CTS_FLOW) {
183                         spin_lock_irq(&uport->lock);
184                         if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
185                                 tty->hw_stopped = 1;
186                         spin_unlock_irq(&uport->lock);
187                 }
188         }
189
190         /*
191          * This is to allow setserial on this port. People may want to set
192          * port/irq/type and then reconfigure the port properly if it failed
193          * now.
194          */
195         if (retval && capable(CAP_SYS_ADMIN))
196                 return 1;
197
198         return retval;
199 }
200
201 static int uart_startup(struct tty_struct *tty, struct uart_state *state,
202                 int init_hw)
203 {
204         struct tty_port *port = &state->port;
205         int retval;
206
207         if (port->flags & ASYNC_INITIALIZED)
208                 return 0;
209
210         /*
211          * Set the TTY IO error marker - we will only clear this
212          * once we have successfully opened the port.
213          */
214         set_bit(TTY_IO_ERROR, &tty->flags);
215
216         retval = uart_port_startup(tty, state, init_hw);
217         if (!retval) {
218                 set_bit(ASYNCB_INITIALIZED, &port->flags);
219                 clear_bit(TTY_IO_ERROR, &tty->flags);
220         } else if (retval > 0)
221                 retval = 0;
222
223         return retval;
224 }
225
226 /*
227  * This routine will shutdown a serial port; interrupts are disabled, and
228  * DTR is dropped if the hangup on close termio flag is on.  Calls to
229  * uart_shutdown are serialised by the per-port semaphore.
230  */
231 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
232 {
233         struct uart_port *uport = state->uart_port;
234         struct tty_port *port = &state->port;
235
236         /*
237          * Set the TTY IO error marker
238          */
239         if (tty)
240                 set_bit(TTY_IO_ERROR, &tty->flags);
241
242         if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
243                 /*
244                  * Turn off DTR and RTS early.
245                  */
246                 if (!tty || (tty->termios->c_cflag & HUPCL))
247                         uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
248
249                 uart_port_shutdown(port);
250         }
251
252         /*
253          * It's possible for shutdown to be called after suspend if we get
254          * a DCD drop (hangup) at just the right time.  Clear suspended bit so
255          * we don't try to resume a port that has been shutdown.
256          */
257         clear_bit(ASYNCB_SUSPENDED, &port->flags);
258
259         /*
260          * Free the transmit buffer page.
261          */
262         if (state->xmit.buf) {
263                 free_page((unsigned long)state->xmit.buf);
264                 state->xmit.buf = NULL;
265         }
266 }
267
268 /**
269  *      uart_update_timeout - update per-port FIFO timeout.
270  *      @port:  uart_port structure describing the port
271  *      @cflag: termios cflag value
272  *      @baud:  speed of the port
273  *
274  *      Set the port FIFO timeout value.  The @cflag value should
275  *      reflect the actual hardware settings.
276  */
277 void
278 uart_update_timeout(struct uart_port *port, unsigned int cflag,
279                     unsigned int baud)
280 {
281         unsigned int bits;
282
283         /* byte size and parity */
284         switch (cflag & CSIZE) {
285         case CS5:
286                 bits = 7;
287                 break;
288         case CS6:
289                 bits = 8;
290                 break;
291         case CS7:
292                 bits = 9;
293                 break;
294         default:
295                 bits = 10;
296                 break; /* CS8 */
297         }
298
299         if (cflag & CSTOPB)
300                 bits++;
301         if (cflag & PARENB)
302                 bits++;
303
304         /*
305          * The total number of bits to be transmitted in the fifo.
306          */
307         bits = bits * port->fifosize;
308
309         /*
310          * Figure the timeout to send the above number of bits.
311          * Add .02 seconds of slop
312          */
313         port->timeout = (HZ * bits) / baud + HZ/50;
314 }
315
316 EXPORT_SYMBOL(uart_update_timeout);
317
318 /**
319  *      uart_get_baud_rate - return baud rate for a particular port
320  *      @port: uart_port structure describing the port in question.
321  *      @termios: desired termios settings.
322  *      @old: old termios (or NULL)
323  *      @min: minimum acceptable baud rate
324  *      @max: maximum acceptable baud rate
325  *
326  *      Decode the termios structure into a numeric baud rate,
327  *      taking account of the magic 38400 baud rate (with spd_*
328  *      flags), and mapping the %B0 rate to 9600 baud.
329  *
330  *      If the new baud rate is invalid, try the old termios setting.
331  *      If it's still invalid, we try 9600 baud.
332  *
333  *      Update the @termios structure to reflect the baud rate
334  *      we're actually going to be using. Don't do this for the case
335  *      where B0 is requested ("hang up").
336  */
337 unsigned int
338 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
339                    struct ktermios *old, unsigned int min, unsigned int max)
340 {
341         unsigned int try, baud, altbaud = 38400;
342         int hung_up = 0;
343         upf_t flags = port->flags & UPF_SPD_MASK;
344
345         if (flags == UPF_SPD_HI)
346                 altbaud = 57600;
347         else if (flags == UPF_SPD_VHI)
348                 altbaud = 115200;
349         else if (flags == UPF_SPD_SHI)
350                 altbaud = 230400;
351         else if (flags == UPF_SPD_WARP)
352                 altbaud = 460800;
353
354         for (try = 0; try < 2; try++) {
355                 baud = tty_termios_baud_rate(termios);
356
357                 /*
358                  * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
359                  * Die! Die! Die!
360                  */
361                 if (baud == 38400)
362                         baud = altbaud;
363
364                 /*
365                  * Special case: B0 rate.
366                  */
367                 if (baud == 0) {
368                         hung_up = 1;
369                         baud = 9600;
370                 }
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                         baud = tty_termios_baud_rate(old);
382                         if (!hung_up)
383                                 tty_termios_encode_baud_rate(termios,
384                                                                 baud, baud);
385                         old = NULL;
386                         continue;
387                 }
388
389                 /*
390                  * As a last resort, if the range cannot be met then clip to
391                  * the nearest chip supported rate.
392                  */
393                 if (!hung_up) {
394                         if (baud <= min)
395                                 tty_termios_encode_baud_rate(termios,
396                                                         min + 1, min + 1);
397                         else
398                                 tty_termios_encode_baud_rate(termios,
399                                                         max - 1, max - 1);
400                 }
401         }
402         /* Should never happen */
403         WARN_ON(1);
404         return 0;
405 }
406
407 EXPORT_SYMBOL(uart_get_baud_rate);
408
409 /**
410  *      uart_get_divisor - return uart clock divisor
411  *      @port: uart_port structure describing the port.
412  *      @baud: desired baud rate
413  *
414  *      Calculate the uart clock divisor for the port.
415  */
416 unsigned int
417 uart_get_divisor(struct uart_port *port, unsigned int baud)
418 {
419         unsigned int quot;
420
421         /*
422          * Old custom speed handling.
423          */
424         if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
425                 quot = port->custom_divisor;
426         else
427                 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
428
429         return quot;
430 }
431
432 EXPORT_SYMBOL(uart_get_divisor);
433
434 /* FIXME: Consistent locking policy */
435 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
436                                         struct ktermios *old_termios)
437 {
438         struct tty_port *port = &state->port;
439         struct uart_port *uport = state->uart_port;
440         struct ktermios *termios;
441
442         /*
443          * If we have no tty, termios, or the port does not exist,
444          * then we can't set the parameters for this port.
445          */
446         if (!tty || !tty->termios || uport->type == PORT_UNKNOWN)
447                 return;
448
449         termios = tty->termios;
450
451         /*
452          * Set flags based on termios cflag
453          */
454         if (termios->c_cflag & CRTSCTS)
455                 set_bit(ASYNCB_CTS_FLOW, &port->flags);
456         else
457                 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
458
459         if (termios->c_cflag & CLOCAL)
460                 clear_bit(ASYNCB_CHECK_CD, &port->flags);
461         else
462                 set_bit(ASYNCB_CHECK_CD, &port->flags);
463
464         uport->ops->set_termios(uport, termios, old_termios);
465 }
466
467 static inline int __uart_put_char(struct uart_port *port,
468                                 struct circ_buf *circ, unsigned char c)
469 {
470         unsigned long flags;
471         int ret = 0;
472
473         if (!circ->buf)
474                 return 0;
475
476         spin_lock_irqsave(&port->lock, flags);
477         if (uart_circ_chars_free(circ) != 0) {
478                 circ->buf[circ->head] = c;
479                 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
480                 ret = 1;
481         }
482         spin_unlock_irqrestore(&port->lock, flags);
483         return ret;
484 }
485
486 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
487 {
488         struct uart_state *state = tty->driver_data;
489
490         return __uart_put_char(state->uart_port, &state->xmit, ch);
491 }
492
493 static void uart_flush_chars(struct tty_struct *tty)
494 {
495         uart_start(tty);
496 }
497
498 static int uart_write(struct tty_struct *tty,
499                                         const unsigned char *buf, int count)
500 {
501         struct uart_state *state = tty->driver_data;
502         struct uart_port *port;
503         struct circ_buf *circ;
504         unsigned long flags;
505         int c, ret = 0;
506
507         /*
508          * This means you called this function _after_ the port was
509          * closed.  No cookie for you.
510          */
511         if (!state) {
512                 WARN_ON(1);
513                 return -EL3HLT;
514         }
515
516         port = state->uart_port;
517         circ = &state->xmit;
518
519         if (!circ->buf)
520                 return 0;
521
522         spin_lock_irqsave(&port->lock, flags);
523         while (1) {
524                 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
525                 if (count < c)
526                         c = count;
527                 if (c <= 0)
528                         break;
529                 memcpy(circ->buf + circ->head, buf, c);
530                 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
531                 buf += c;
532                 count -= c;
533                 ret += c;
534         }
535         spin_unlock_irqrestore(&port->lock, flags);
536
537         uart_start(tty);
538         return ret;
539 }
540
541 static int uart_write_room(struct tty_struct *tty)
542 {
543         struct uart_state *state = tty->driver_data;
544         unsigned long flags;
545         int ret;
546
547         spin_lock_irqsave(&state->uart_port->lock, flags);
548         ret = uart_circ_chars_free(&state->xmit);
549         spin_unlock_irqrestore(&state->uart_port->lock, flags);
550         return ret;
551 }
552
553 static int uart_chars_in_buffer(struct tty_struct *tty)
554 {
555         struct uart_state *state = tty->driver_data;
556         unsigned long flags;
557         int ret;
558
559         spin_lock_irqsave(&state->uart_port->lock, flags);
560         ret = uart_circ_chars_pending(&state->xmit);
561         spin_unlock_irqrestore(&state->uart_port->lock, flags);
562         return ret;
563 }
564
565 static void uart_flush_buffer(struct tty_struct *tty)
566 {
567         struct uart_state *state = tty->driver_data;
568         struct uart_port *port;
569         unsigned long flags;
570
571         /*
572          * This means you called this function _after_ the port was
573          * closed.  No cookie for you.
574          */
575         if (!state) {
576                 WARN_ON(1);
577                 return;
578         }
579
580         port = state->uart_port;
581         pr_debug("uart_flush_buffer(%d) called\n", tty->index);
582
583         spin_lock_irqsave(&port->lock, flags);
584         uart_circ_clear(&state->xmit);
585         if (port->ops->flush_buffer)
586                 port->ops->flush_buffer(port);
587         spin_unlock_irqrestore(&port->lock, flags);
588         tty_wakeup(tty);
589 }
590
591 /*
592  * This function is used to send a high-priority XON/XOFF character to
593  * the device
594  */
595 static void uart_send_xchar(struct tty_struct *tty, char ch)
596 {
597         struct uart_state *state = tty->driver_data;
598         struct uart_port *port = state->uart_port;
599         unsigned long flags;
600
601         if (port->ops->send_xchar)
602                 port->ops->send_xchar(port, ch);
603         else {
604                 port->x_char = ch;
605                 if (ch) {
606                         spin_lock_irqsave(&port->lock, flags);
607                         port->ops->start_tx(port);
608                         spin_unlock_irqrestore(&port->lock, flags);
609                 }
610         }
611 }
612
613 static void uart_throttle(struct tty_struct *tty)
614 {
615         struct uart_state *state = tty->driver_data;
616
617         if (I_IXOFF(tty))
618                 uart_send_xchar(tty, STOP_CHAR(tty));
619
620         if (tty->termios->c_cflag & CRTSCTS)
621                 uart_clear_mctrl(state->uart_port, TIOCM_RTS);
622 }
623
624 static void uart_unthrottle(struct tty_struct *tty)
625 {
626         struct uart_state *state = tty->driver_data;
627         struct uart_port *port = state->uart_port;
628
629         if (I_IXOFF(tty)) {
630                 if (port->x_char)
631                         port->x_char = 0;
632                 else
633                         uart_send_xchar(tty, START_CHAR(tty));
634         }
635
636         if (tty->termios->c_cflag & CRTSCTS)
637                 uart_set_mctrl(port, TIOCM_RTS);
638 }
639
640 static int uart_get_info(struct uart_state *state,
641                          struct serial_struct __user *retinfo)
642 {
643         struct uart_port *uport = state->uart_port;
644         struct tty_port *port = &state->port;
645         struct serial_struct tmp;
646
647         memset(&tmp, 0, sizeof(tmp));
648
649         /* Ensure the state we copy is consistent and no hardware changes
650            occur as we go */
651         mutex_lock(&port->mutex);
652
653         tmp.type            = uport->type;
654         tmp.line            = uport->line;
655         tmp.port            = uport->iobase;
656         if (HIGH_BITS_OFFSET)
657                 tmp.port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
658         tmp.irq             = uport->irq;
659         tmp.flags           = uport->flags;
660         tmp.xmit_fifo_size  = uport->fifosize;
661         tmp.baud_base       = uport->uartclk / 16;
662         tmp.close_delay     = jiffies_to_msecs(port->close_delay) / 10;
663         tmp.closing_wait    = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
664                                 ASYNC_CLOSING_WAIT_NONE :
665                                 jiffies_to_msecs(port->closing_wait) / 10;
666         tmp.custom_divisor  = uport->custom_divisor;
667         tmp.hub6            = uport->hub6;
668         tmp.io_type         = uport->iotype;
669         tmp.iomem_reg_shift = uport->regshift;
670         tmp.iomem_base      = (void *)(unsigned long)uport->mapbase;
671
672         mutex_unlock(&port->mutex);
673
674         if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
675                 return -EFAULT;
676         return 0;
677 }
678
679 static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
680                          struct serial_struct __user *newinfo)
681 {
682         struct serial_struct new_serial;
683         struct uart_port *uport = state->uart_port;
684         struct tty_port *port = &state->port;
685         unsigned long new_port;
686         unsigned int change_irq, change_port, closing_wait;
687         unsigned int old_custom_divisor, close_delay;
688         upf_t old_flags, new_flags;
689         int retval = 0;
690
691         if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
692                 return -EFAULT;
693
694         new_port = new_serial.port;
695         if (HIGH_BITS_OFFSET)
696                 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
697
698         new_serial.irq = irq_canonicalize(new_serial.irq);
699         close_delay = msecs_to_jiffies(new_serial.close_delay * 10);
700         closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
701                         ASYNC_CLOSING_WAIT_NONE :
702                         msecs_to_jiffies(new_serial.closing_wait * 10);
703
704         /*
705          * This semaphore protects port->count.  It is also
706          * very useful to prevent opens.  Also, take the
707          * port configuration semaphore to make sure that a
708          * module insertion/removal doesn't change anything
709          * under us.
710          */
711         mutex_lock(&port->mutex);
712
713         change_irq  = !(uport->flags & UPF_FIXED_PORT)
714                 && new_serial.irq != uport->irq;
715
716         /*
717          * Since changing the 'type' of the port changes its resource
718          * allocations, we should treat type changes the same as
719          * IO port changes.
720          */
721         change_port = !(uport->flags & UPF_FIXED_PORT)
722                 && (new_port != uport->iobase ||
723                     (unsigned long)new_serial.iomem_base != uport->mapbase ||
724                     new_serial.hub6 != uport->hub6 ||
725                     new_serial.io_type != uport->iotype ||
726                     new_serial.iomem_reg_shift != uport->regshift ||
727                     new_serial.type != uport->type);
728
729         old_flags = uport->flags;
730         new_flags = new_serial.flags;
731         old_custom_divisor = uport->custom_divisor;
732
733         if (!capable(CAP_SYS_ADMIN)) {
734                 retval = -EPERM;
735                 if (change_irq || change_port ||
736                     (new_serial.baud_base != uport->uartclk / 16) ||
737                     (close_delay != port->close_delay) ||
738                     (closing_wait != port->closing_wait) ||
739                     (new_serial.xmit_fifo_size &&
740                      new_serial.xmit_fifo_size != uport->fifosize) ||
741                     (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
742                         goto exit;
743                 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
744                                (new_flags & UPF_USR_MASK));
745                 uport->custom_divisor = new_serial.custom_divisor;
746                 goto check_and_exit;
747         }
748
749         /*
750          * Ask the low level driver to verify the settings.
751          */
752         if (uport->ops->verify_port)
753                 retval = uport->ops->verify_port(uport, &new_serial);
754
755         if ((new_serial.irq >= nr_irqs) || (new_serial.irq < 0) ||
756             (new_serial.baud_base < 9600))
757                 retval = -EINVAL;
758
759         if (retval)
760                 goto exit;
761
762         if (change_port || change_irq) {
763                 retval = -EBUSY;
764
765                 /*
766                  * Make sure that we are the sole user of this port.
767                  */
768                 if (tty_port_users(port) > 1)
769                         goto exit;
770
771                 /*
772                  * We need to shutdown the serial port at the old
773                  * port/type/irq combination.
774                  */
775                 uart_shutdown(tty, state);
776         }
777
778         if (change_port) {
779                 unsigned long old_iobase, old_mapbase;
780                 unsigned int old_type, old_iotype, old_hub6, old_shift;
781
782                 old_iobase = uport->iobase;
783                 old_mapbase = uport->mapbase;
784                 old_type = uport->type;
785                 old_hub6 = uport->hub6;
786                 old_iotype = uport->iotype;
787                 old_shift = uport->regshift;
788
789                 /*
790                  * Free and release old regions
791                  */
792                 if (old_type != PORT_UNKNOWN)
793                         uport->ops->release_port(uport);
794
795                 uport->iobase = new_port;
796                 uport->type = new_serial.type;
797                 uport->hub6 = new_serial.hub6;
798                 uport->iotype = new_serial.io_type;
799                 uport->regshift = new_serial.iomem_reg_shift;
800                 uport->mapbase = (unsigned long)new_serial.iomem_base;
801
802                 /*
803                  * Claim and map the new regions
804                  */
805                 if (uport->type != PORT_UNKNOWN) {
806                         retval = uport->ops->request_port(uport);
807                 } else {
808                         /* Always success - Jean II */
809                         retval = 0;
810                 }
811
812                 /*
813                  * If we fail to request resources for the
814                  * new port, try to restore the old settings.
815                  */
816                 if (retval && old_type != PORT_UNKNOWN) {
817                         uport->iobase = old_iobase;
818                         uport->type = old_type;
819                         uport->hub6 = old_hub6;
820                         uport->iotype = old_iotype;
821                         uport->regshift = old_shift;
822                         uport->mapbase = old_mapbase;
823                         retval = uport->ops->request_port(uport);
824                         /*
825                          * If we failed to restore the old settings,
826                          * we fail like this.
827                          */
828                         if (retval)
829                                 uport->type = PORT_UNKNOWN;
830
831                         /*
832                          * We failed anyway.
833                          */
834                         retval = -EBUSY;
835                         /* Added to return the correct error -Ram Gupta */
836                         goto exit;
837                 }
838         }
839
840         if (change_irq)
841                 uport->irq      = new_serial.irq;
842         if (!(uport->flags & UPF_FIXED_PORT))
843                 uport->uartclk  = new_serial.baud_base * 16;
844         uport->flags            = (uport->flags & ~UPF_CHANGE_MASK) |
845                                  (new_flags & UPF_CHANGE_MASK);
846         uport->custom_divisor   = new_serial.custom_divisor;
847         port->close_delay     = close_delay;
848         port->closing_wait    = closing_wait;
849         if (new_serial.xmit_fifo_size)
850                 uport->fifosize = new_serial.xmit_fifo_size;
851         if (port->tty)
852                 port->tty->low_latency =
853                         (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
854
855  check_and_exit:
856         retval = 0;
857         if (uport->type == PORT_UNKNOWN)
858                 goto exit;
859         if (port->flags & ASYNC_INITIALIZED) {
860                 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
861                     old_custom_divisor != uport->custom_divisor) {
862                         /*
863                          * If they're setting up a custom divisor or speed,
864                          * instead of clearing it, then bitch about it. No
865                          * need to rate-limit; it's CAP_SYS_ADMIN only.
866                          */
867                         if (uport->flags & UPF_SPD_MASK) {
868                                 char buf[64];
869                                 printk(KERN_NOTICE
870                                        "%s sets custom speed on %s. This "
871                                        "is deprecated.\n", current->comm,
872                                        tty_name(port->tty, buf));
873                         }
874                         uart_change_speed(tty, state, NULL);
875                 }
876         } else
877                 retval = uart_startup(tty, state, 1);
878  exit:
879         mutex_unlock(&port->mutex);
880         return retval;
881 }
882
883 /**
884  *      uart_get_lsr_info       -       get line status register info
885  *      @tty: tty associated with the UART
886  *      @state: UART being queried
887  *      @value: returned modem value
888  *
889  *      Note: uart_ioctl protects us against hangups.
890  */
891 static int uart_get_lsr_info(struct tty_struct *tty,
892                         struct uart_state *state, unsigned int __user *value)
893 {
894         struct uart_port *uport = state->uart_port;
895         unsigned int result;
896
897         result = uport->ops->tx_empty(uport);
898
899         /*
900          * If we're about to load something into the transmit
901          * register, we'll pretend the transmitter isn't empty to
902          * avoid a race condition (depending on when the transmit
903          * interrupt happens).
904          */
905         if (uport->x_char ||
906             ((uart_circ_chars_pending(&state->xmit) > 0) &&
907              !tty->stopped && !tty->hw_stopped))
908                 result &= ~TIOCSER_TEMT;
909
910         return put_user(result, value);
911 }
912
913 static int uart_tiocmget(struct tty_struct *tty)
914 {
915         struct uart_state *state = tty->driver_data;
916         struct tty_port *port = &state->port;
917         struct uart_port *uport = state->uart_port;
918         int result = -EIO;
919
920         mutex_lock(&port->mutex);
921         if (!(tty->flags & (1 << TTY_IO_ERROR))) {
922                 result = uport->mctrl;
923                 spin_lock_irq(&uport->lock);
924                 result |= uport->ops->get_mctrl(uport);
925                 spin_unlock_irq(&uport->lock);
926         }
927         mutex_unlock(&port->mutex);
928
929         return result;
930 }
931
932 static int
933 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
934 {
935         struct uart_state *state = tty->driver_data;
936         struct uart_port *uport = state->uart_port;
937         struct tty_port *port = &state->port;
938         int ret = -EIO;
939
940         mutex_lock(&port->mutex);
941         if (!(tty->flags & (1 << TTY_IO_ERROR))) {
942                 uart_update_mctrl(uport, set, clear);
943                 ret = 0;
944         }
945         mutex_unlock(&port->mutex);
946         return ret;
947 }
948
949 static int uart_break_ctl(struct tty_struct *tty, int break_state)
950 {
951         struct uart_state *state = tty->driver_data;
952         struct tty_port *port = &state->port;
953         struct uart_port *uport = state->uart_port;
954
955         mutex_lock(&port->mutex);
956
957         if (uport->type != PORT_UNKNOWN)
958                 uport->ops->break_ctl(uport, break_state);
959
960         mutex_unlock(&port->mutex);
961         return 0;
962 }
963
964 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
965 {
966         struct uart_port *uport = state->uart_port;
967         struct tty_port *port = &state->port;
968         int flags, ret;
969
970         if (!capable(CAP_SYS_ADMIN))
971                 return -EPERM;
972
973         /*
974          * Take the per-port semaphore.  This prevents count from
975          * changing, and hence any extra opens of the port while
976          * we're auto-configuring.
977          */
978         if (mutex_lock_interruptible(&port->mutex))
979                 return -ERESTARTSYS;
980
981         ret = -EBUSY;
982         if (tty_port_users(port) == 1) {
983                 uart_shutdown(tty, state);
984
985                 /*
986                  * If we already have a port type configured,
987                  * we must release its resources.
988                  */
989                 if (uport->type != PORT_UNKNOWN)
990                         uport->ops->release_port(uport);
991
992                 flags = UART_CONFIG_TYPE;
993                 if (uport->flags & UPF_AUTO_IRQ)
994                         flags |= UART_CONFIG_IRQ;
995
996                 /*
997                  * This will claim the ports resources if
998                  * a port is found.
999                  */
1000                 uport->ops->config_port(uport, flags);
1001
1002                 ret = uart_startup(tty, state, 1);
1003         }
1004         mutex_unlock(&port->mutex);
1005         return ret;
1006 }
1007
1008 /*
1009  * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1010  * - mask passed in arg for lines of interest
1011  *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1012  * Caller should use TIOCGICOUNT to see which one it was
1013  *
1014  * FIXME: This wants extracting into a common all driver implementation
1015  * of TIOCMWAIT using tty_port.
1016  */
1017 static int
1018 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1019 {
1020         struct uart_port *uport = state->uart_port;
1021         struct tty_port *port = &state->port;
1022         DECLARE_WAITQUEUE(wait, current);
1023         struct uart_icount cprev, cnow;
1024         int ret;
1025
1026         /*
1027          * note the counters on entry
1028          */
1029         spin_lock_irq(&uport->lock);
1030         memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1031
1032         /*
1033          * Force modem status interrupts on
1034          */
1035         uport->ops->enable_ms(uport);
1036         spin_unlock_irq(&uport->lock);
1037
1038         add_wait_queue(&port->delta_msr_wait, &wait);
1039         for (;;) {
1040                 spin_lock_irq(&uport->lock);
1041                 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1042                 spin_unlock_irq(&uport->lock);
1043
1044                 set_current_state(TASK_INTERRUPTIBLE);
1045
1046                 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1047                     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1048                     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1049                     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1050                         ret = 0;
1051                         break;
1052                 }
1053
1054                 schedule();
1055
1056                 /* see if a signal did it */
1057                 if (signal_pending(current)) {
1058                         ret = -ERESTARTSYS;
1059                         break;
1060                 }
1061
1062                 cprev = cnow;
1063         }
1064
1065         current->state = TASK_RUNNING;
1066         remove_wait_queue(&port->delta_msr_wait, &wait);
1067
1068         return ret;
1069 }
1070
1071 /*
1072  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1073  * Return: write counters to the user passed counter struct
1074  * NB: both 1->0 and 0->1 transitions are counted except for
1075  *     RI where only 0->1 is counted.
1076  */
1077 static int uart_get_icount(struct tty_struct *tty,
1078                           struct serial_icounter_struct *icount)
1079 {
1080         struct uart_state *state = tty->driver_data;
1081         struct uart_icount cnow;
1082         struct uart_port *uport = state->uart_port;
1083
1084         spin_lock_irq(&uport->lock);
1085         memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1086         spin_unlock_irq(&uport->lock);
1087
1088         icount->cts         = cnow.cts;
1089         icount->dsr         = cnow.dsr;
1090         icount->rng         = cnow.rng;
1091         icount->dcd         = cnow.dcd;
1092         icount->rx          = cnow.rx;
1093         icount->tx          = cnow.tx;
1094         icount->frame       = cnow.frame;
1095         icount->overrun     = cnow.overrun;
1096         icount->parity      = cnow.parity;
1097         icount->brk         = cnow.brk;
1098         icount->buf_overrun = cnow.buf_overrun;
1099
1100         return 0;
1101 }
1102
1103 /*
1104  * Called via sys_ioctl.  We can use spin_lock_irq() here.
1105  */
1106 static int
1107 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1108            unsigned long arg)
1109 {
1110         struct uart_state *state = tty->driver_data;
1111         struct tty_port *port = &state->port;
1112         void __user *uarg = (void __user *)arg;
1113         int ret = -ENOIOCTLCMD;
1114
1115
1116         /*
1117          * These ioctls don't rely on the hardware to be present.
1118          */
1119         switch (cmd) {
1120         case TIOCGSERIAL:
1121                 ret = uart_get_info(state, uarg);
1122                 break;
1123
1124         case TIOCSSERIAL:
1125                 ret = uart_set_info(tty, state, uarg);
1126                 break;
1127
1128         case TIOCSERCONFIG:
1129                 ret = uart_do_autoconfig(tty, state);
1130                 break;
1131
1132         case TIOCSERGWILD: /* obsolete */
1133         case TIOCSERSWILD: /* obsolete */
1134                 ret = 0;
1135                 break;
1136         }
1137
1138         if (ret != -ENOIOCTLCMD)
1139                 goto out;
1140
1141         if (tty->flags & (1 << TTY_IO_ERROR)) {
1142                 ret = -EIO;
1143                 goto out;
1144         }
1145
1146         /*
1147          * The following should only be used when hardware is present.
1148          */
1149         switch (cmd) {
1150         case TIOCMIWAIT:
1151                 ret = uart_wait_modem_status(state, arg);
1152                 break;
1153         }
1154
1155         if (ret != -ENOIOCTLCMD)
1156                 goto out;
1157
1158         mutex_lock(&port->mutex);
1159
1160         if (tty->flags & (1 << TTY_IO_ERROR)) {
1161                 ret = -EIO;
1162                 goto out_up;
1163         }
1164
1165         /*
1166          * All these rely on hardware being present and need to be
1167          * protected against the tty being hung up.
1168          */
1169         switch (cmd) {
1170         case TIOCSERGETLSR: /* Get line status register */
1171                 ret = uart_get_lsr_info(tty, state, uarg);
1172                 break;
1173
1174         default: {
1175                 struct uart_port *uport = state->uart_port;
1176                 if (uport->ops->ioctl)
1177                         ret = uport->ops->ioctl(uport, cmd, arg);
1178                 break;
1179         }
1180         }
1181 out_up:
1182         mutex_unlock(&port->mutex);
1183 out:
1184         return ret;
1185 }
1186
1187 static void uart_set_ldisc(struct tty_struct *tty)
1188 {
1189         struct uart_state *state = tty->driver_data;
1190         struct uart_port *uport = state->uart_port;
1191
1192         if (uport->ops->set_ldisc)
1193                 uport->ops->set_ldisc(uport, tty->termios->c_line);
1194 }
1195
1196 static void uart_set_termios(struct tty_struct *tty,
1197                                                 struct ktermios *old_termios)
1198 {
1199         struct uart_state *state = tty->driver_data;
1200         unsigned long flags;
1201         unsigned int cflag = tty->termios->c_cflag;
1202
1203
1204         /*
1205          * These are the bits that are used to setup various
1206          * flags in the low level driver. We can ignore the Bfoo
1207          * bits in c_cflag; c_[io]speed will always be set
1208          * appropriately by set_termios() in tty_ioctl.c
1209          */
1210 #define RELEVANT_IFLAG(iflag)   ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1211         if ((cflag ^ old_termios->c_cflag) == 0 &&
1212             tty->termios->c_ospeed == old_termios->c_ospeed &&
1213             tty->termios->c_ispeed == old_termios->c_ispeed &&
1214             RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) {
1215                 return;
1216         }
1217
1218         uart_change_speed(tty, state, old_termios);
1219
1220         /* Handle transition to B0 status */
1221         if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1222                 uart_clear_mctrl(state->uart_port, TIOCM_RTS | TIOCM_DTR);
1223         /* Handle transition away from B0 status */
1224         else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1225                 unsigned int mask = TIOCM_DTR;
1226                 if (!(cflag & CRTSCTS) ||
1227                     !test_bit(TTY_THROTTLED, &tty->flags))
1228                         mask |= TIOCM_RTS;
1229                 uart_set_mctrl(state->uart_port, mask);
1230         }
1231
1232         /* Handle turning off CRTSCTS */
1233         if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1234                 spin_lock_irqsave(&state->uart_port->lock, flags);
1235                 tty->hw_stopped = 0;
1236                 __uart_start(tty);
1237                 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1238         }
1239         /* Handle turning on CRTSCTS */
1240         else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1241                 spin_lock_irqsave(&state->uart_port->lock, flags);
1242                 if (!(state->uart_port->ops->get_mctrl(state->uart_port) & TIOCM_CTS)) {
1243                         tty->hw_stopped = 1;
1244                         state->uart_port->ops->stop_tx(state->uart_port);
1245                 }
1246                 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1247         }
1248 }
1249
1250 /*
1251  * In 2.4.5, calls to this will be serialized via the BKL in
1252  *  linux/drivers/char/tty_io.c:tty_release()
1253  *  linux/drivers/char/tty_io.c:do_tty_handup()
1254  */
1255 static void uart_close(struct tty_struct *tty, struct file *filp)
1256 {
1257         struct uart_state *state = tty->driver_data;
1258         struct tty_port *port;
1259         struct uart_port *uport;
1260         unsigned long flags;
1261
1262         if (!state)
1263                 return;
1264
1265         uport = state->uart_port;
1266         port = &state->port;
1267
1268         pr_debug("uart_close(%d) called\n", uport->line);
1269
1270         if (tty_port_close_start(port, tty, filp) == 0)
1271                 return;
1272
1273         /*
1274          * At this point, we stop accepting input.  To do this, we
1275          * disable the receive line status interrupts.
1276          */
1277         if (port->flags & ASYNC_INITIALIZED) {
1278                 unsigned long flags;
1279                 spin_lock_irqsave(&uport->lock, flags);
1280                 uport->ops->stop_rx(uport);
1281                 spin_unlock_irqrestore(&uport->lock, flags);
1282                 /*
1283                  * Before we drop DTR, make sure the UART transmitter
1284                  * has completely drained; this is especially
1285                  * important if there is a transmit FIFO!
1286                  */
1287                 uart_wait_until_sent(tty, uport->timeout);
1288         }
1289
1290         mutex_lock(&port->mutex);
1291         uart_shutdown(tty, state);
1292         uart_flush_buffer(tty);
1293
1294         tty_ldisc_flush(tty);
1295
1296         tty_port_tty_set(port, NULL);
1297         spin_lock_irqsave(&port->lock, flags);
1298         tty->closing = 0;
1299
1300         if (port->blocked_open) {
1301                 spin_unlock_irqrestore(&port->lock, flags);
1302                 if (port->close_delay)
1303                         msleep_interruptible(
1304                                         jiffies_to_msecs(port->close_delay));
1305                 spin_lock_irqsave(&port->lock, flags);
1306         } else if (!uart_console(uport)) {
1307                 spin_unlock_irqrestore(&port->lock, flags);
1308                 uart_change_pm(state, 3);
1309                 spin_lock_irqsave(&port->lock, flags);
1310         }
1311
1312         /*
1313          * Wake up anyone trying to open this port.
1314          */
1315         clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1316         clear_bit(ASYNCB_CLOSING, &port->flags);
1317         spin_unlock_irqrestore(&port->lock, flags);
1318         wake_up_interruptible(&port->open_wait);
1319         wake_up_interruptible(&port->close_wait);
1320
1321         mutex_unlock(&port->mutex);
1322 }
1323
1324 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1325 {
1326         struct uart_state *state = tty->driver_data;
1327         struct uart_port *port = state->uart_port;
1328         unsigned long char_time, expire;
1329
1330         if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1331                 return;
1332
1333         /*
1334          * Set the check interval to be 1/5 of the estimated time to
1335          * send a single character, and make it at least 1.  The check
1336          * interval should also be less than the timeout.
1337          *
1338          * Note: we have to use pretty tight timings here to satisfy
1339          * the NIST-PCTS.
1340          */
1341         char_time = (port->timeout - HZ/50) / port->fifosize;
1342         char_time = char_time / 5;
1343         if (char_time == 0)
1344                 char_time = 1;
1345         if (timeout && timeout < char_time)
1346                 char_time = timeout;
1347
1348         /*
1349          * If the transmitter hasn't cleared in twice the approximate
1350          * amount of time to send the entire FIFO, it probably won't
1351          * ever clear.  This assumes the UART isn't doing flow
1352          * control, which is currently the case.  Hence, if it ever
1353          * takes longer than port->timeout, this is probably due to a
1354          * UART bug of some kind.  So, we clamp the timeout parameter at
1355          * 2*port->timeout.
1356          */
1357         if (timeout == 0 || timeout > 2 * port->timeout)
1358                 timeout = 2 * port->timeout;
1359
1360         expire = jiffies + timeout;
1361
1362         pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1363                 port->line, jiffies, expire);
1364
1365         /*
1366          * Check whether the transmitter is empty every 'char_time'.
1367          * 'timeout' / 'expire' give us the maximum amount of time
1368          * we wait.
1369          */
1370         while (!port->ops->tx_empty(port)) {
1371                 msleep_interruptible(jiffies_to_msecs(char_time));
1372                 if (signal_pending(current))
1373                         break;
1374                 if (time_after(jiffies, expire))
1375                         break;
1376         }
1377 }
1378
1379 /*
1380  * This is called with the BKL held in
1381  *  linux/drivers/char/tty_io.c:do_tty_hangup()
1382  * We're called from the eventd thread, so we can sleep for
1383  * a _short_ time only.
1384  */
1385 static void uart_hangup(struct tty_struct *tty)
1386 {
1387         struct uart_state *state = tty->driver_data;
1388         struct tty_port *port = &state->port;
1389         unsigned long flags;
1390
1391         pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1392
1393         mutex_lock(&port->mutex);
1394         if (port->flags & ASYNC_NORMAL_ACTIVE) {
1395                 uart_flush_buffer(tty);
1396                 uart_shutdown(tty, state);
1397                 spin_lock_irqsave(&port->lock, flags);
1398                 port->count = 0;
1399                 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1400                 spin_unlock_irqrestore(&port->lock, flags);
1401                 tty_port_tty_set(port, NULL);
1402                 wake_up_interruptible(&port->open_wait);
1403                 wake_up_interruptible(&port->delta_msr_wait);
1404         }
1405         mutex_unlock(&port->mutex);
1406 }
1407
1408 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1409 {
1410         return 0;
1411 }
1412
1413 static void uart_port_shutdown(struct tty_port *port)
1414 {
1415         struct uart_state *state = container_of(port, struct uart_state, port);
1416         struct uart_port *uport = state->uart_port;
1417
1418         /*
1419          * clear delta_msr_wait queue to avoid mem leaks: we may free
1420          * the irq here so the queue might never be woken up.  Note
1421          * that we won't end up waiting on delta_msr_wait again since
1422          * any outstanding file descriptors should be pointing at
1423          * hung_up_tty_fops now.
1424          */
1425         wake_up_interruptible(&port->delta_msr_wait);
1426
1427         /*
1428          * Free the IRQ and disable the port.
1429          */
1430         uport->ops->shutdown(uport);
1431
1432         /*
1433          * Ensure that the IRQ handler isn't running on another CPU.
1434          */
1435         synchronize_irq(uport->irq);
1436 }
1437
1438 static int uart_carrier_raised(struct tty_port *port)
1439 {
1440         struct uart_state *state = container_of(port, struct uart_state, port);
1441         struct uart_port *uport = state->uart_port;
1442         int mctrl;
1443         spin_lock_irq(&uport->lock);
1444         uport->ops->enable_ms(uport);
1445         mctrl = uport->ops->get_mctrl(uport);
1446         spin_unlock_irq(&uport->lock);
1447         if (mctrl & TIOCM_CAR)
1448                 return 1;
1449         return 0;
1450 }
1451
1452 static void uart_dtr_rts(struct tty_port *port, int onoff)
1453 {
1454         struct uart_state *state = container_of(port, struct uart_state, port);
1455         struct uart_port *uport = state->uart_port;
1456
1457         if (onoff)
1458                 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1459         else
1460                 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1461 }
1462
1463 /*
1464  * calls to uart_open are serialised by the BKL in
1465  *   fs/char_dev.c:chrdev_open()
1466  * Note that if this fails, then uart_close() _will_ be called.
1467  *
1468  * In time, we want to scrap the "opening nonpresent ports"
1469  * behaviour and implement an alternative way for setserial
1470  * to set base addresses/ports/types.  This will allow us to
1471  * get rid of a certain amount of extra tests.
1472  */
1473 static int uart_open(struct tty_struct *tty, struct file *filp)
1474 {
1475         struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1476         int retval, line = tty->index;
1477         struct uart_state *state = drv->state + line;
1478         struct tty_port *port = &state->port;
1479
1480         pr_debug("uart_open(%d) called\n", line);
1481
1482         /*
1483          * We take the semaphore here to guarantee that we won't be re-entered
1484          * while allocating the state structure, or while we request any IRQs
1485          * that the driver may need.  This also has the nice side-effect that
1486          * it delays the action of uart_hangup, so we can guarantee that
1487          * state->port.tty will always contain something reasonable.
1488          */
1489         if (mutex_lock_interruptible(&port->mutex)) {
1490                 retval = -ERESTARTSYS;
1491                 goto end;
1492         }
1493
1494         port->count++;
1495         if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1496                 retval = -ENXIO;
1497                 goto err_dec_count;
1498         }
1499
1500         /*
1501          * Once we set tty->driver_data here, we are guaranteed that
1502          * uart_close() will decrement the driver module use count.
1503          * Any failures from here onwards should not touch the count.
1504          */
1505         tty->driver_data = state;
1506         state->uart_port->state = state;
1507         tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1508         tty_port_tty_set(port, tty);
1509
1510         /*
1511          * If the port is in the middle of closing, bail out now.
1512          */
1513         if (tty_hung_up_p(filp)) {
1514                 retval = -EAGAIN;
1515                 goto err_dec_count;
1516         }
1517
1518         /*
1519          * Make sure the device is in D0 state.
1520          */
1521         if (port->count == 1)
1522                 uart_change_pm(state, 0);
1523
1524         /*
1525          * Start up the serial port.
1526          */
1527         retval = uart_startup(tty, state, 0);
1528
1529         /*
1530          * If we succeeded, wait until the port is ready.
1531          */
1532         mutex_unlock(&port->mutex);
1533         if (retval == 0)
1534                 retval = tty_port_block_til_ready(port, tty, filp);
1535
1536 end:
1537         return retval;
1538 err_dec_count:
1539         port->count--;
1540         mutex_unlock(&port->mutex);
1541         goto end;
1542 }
1543
1544 static const char *uart_type(struct uart_port *port)
1545 {
1546         const char *str = NULL;
1547
1548         if (port->ops->type)
1549                 str = port->ops->type(port);
1550
1551         if (!str)
1552                 str = "unknown";
1553
1554         return str;
1555 }
1556
1557 #ifdef CONFIG_PROC_FS
1558
1559 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1560 {
1561         struct uart_state *state = drv->state + i;
1562         struct tty_port *port = &state->port;
1563         int pm_state;
1564         struct uart_port *uport = state->uart_port;
1565         char stat_buf[32];
1566         unsigned int status;
1567         int mmio;
1568
1569         if (!uport)
1570                 return;
1571
1572         mmio = uport->iotype >= UPIO_MEM;
1573         seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1574                         uport->line, uart_type(uport),
1575                         mmio ? "mmio:0x" : "port:",
1576                         mmio ? (unsigned long long)uport->mapbase
1577                              : (unsigned long long)uport->iobase,
1578                         uport->irq);
1579
1580         if (uport->type == PORT_UNKNOWN) {
1581                 seq_putc(m, '\n');
1582                 return;
1583         }
1584
1585         if (capable(CAP_SYS_ADMIN)) {
1586                 mutex_lock(&port->mutex);
1587                 pm_state = state->pm_state;
1588                 if (pm_state)
1589                         uart_change_pm(state, 0);
1590                 spin_lock_irq(&uport->lock);
1591                 status = uport->ops->get_mctrl(uport);
1592                 spin_unlock_irq(&uport->lock);
1593                 if (pm_state)
1594                         uart_change_pm(state, pm_state);
1595                 mutex_unlock(&port->mutex);
1596
1597                 seq_printf(m, " tx:%d rx:%d",
1598                                 uport->icount.tx, uport->icount.rx);
1599                 if (uport->icount.frame)
1600                         seq_printf(m, " fe:%d",
1601                                 uport->icount.frame);
1602                 if (uport->icount.parity)
1603                         seq_printf(m, " pe:%d",
1604                                 uport->icount.parity);
1605                 if (uport->icount.brk)
1606                         seq_printf(m, " brk:%d",
1607                                 uport->icount.brk);
1608                 if (uport->icount.overrun)
1609                         seq_printf(m, " oe:%d",
1610                                 uport->icount.overrun);
1611
1612 #define INFOBIT(bit, str) \
1613         if (uport->mctrl & (bit)) \
1614                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1615                         strlen(stat_buf) - 2)
1616 #define STATBIT(bit, str) \
1617         if (status & (bit)) \
1618                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1619                        strlen(stat_buf) - 2)
1620
1621                 stat_buf[0] = '\0';
1622                 stat_buf[1] = '\0';
1623                 INFOBIT(TIOCM_RTS, "|RTS");
1624                 STATBIT(TIOCM_CTS, "|CTS");
1625                 INFOBIT(TIOCM_DTR, "|DTR");
1626                 STATBIT(TIOCM_DSR, "|DSR");
1627                 STATBIT(TIOCM_CAR, "|CD");
1628                 STATBIT(TIOCM_RNG, "|RI");
1629                 if (stat_buf[0])
1630                         stat_buf[0] = ' ';
1631
1632                 seq_puts(m, stat_buf);
1633         }
1634         seq_putc(m, '\n');
1635 #undef STATBIT
1636 #undef INFOBIT
1637 }
1638
1639 static int uart_proc_show(struct seq_file *m, void *v)
1640 {
1641         struct tty_driver *ttydrv = m->private;
1642         struct uart_driver *drv = ttydrv->driver_state;
1643         int i;
1644
1645         seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1646                         "", "", "");
1647         for (i = 0; i < drv->nr; i++)
1648                 uart_line_info(m, drv, i);
1649         return 0;
1650 }
1651
1652 static int uart_proc_open(struct inode *inode, struct file *file)
1653 {
1654         return single_open(file, uart_proc_show, PDE(inode)->data);
1655 }
1656
1657 static const struct file_operations uart_proc_fops = {
1658         .owner          = THIS_MODULE,
1659         .open           = uart_proc_open,
1660         .read           = seq_read,
1661         .llseek         = seq_lseek,
1662         .release        = single_release,
1663 };
1664 #endif
1665
1666 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1667 /*
1668  *      uart_console_write - write a console message to a serial port
1669  *      @port: the port to write the message
1670  *      @s: array of characters
1671  *      @count: number of characters in string to write
1672  *      @write: function to write character to port
1673  */
1674 void uart_console_write(struct uart_port *port, const char *s,
1675                         unsigned int count,
1676                         void (*putchar)(struct uart_port *, int))
1677 {
1678         unsigned int i;
1679
1680         for (i = 0; i < count; i++, s++) {
1681                 if (*s == '\n')
1682                         putchar(port, '\r');
1683                 putchar(port, *s);
1684         }
1685 }
1686 EXPORT_SYMBOL_GPL(uart_console_write);
1687
1688 /*
1689  *      Check whether an invalid uart number has been specified, and
1690  *      if so, search for the first available port that does have
1691  *      console support.
1692  */
1693 struct uart_port * __init
1694 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1695 {
1696         int idx = co->index;
1697
1698         if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1699                                      ports[idx].membase == NULL))
1700                 for (idx = 0; idx < nr; idx++)
1701                         if (ports[idx].iobase != 0 ||
1702                             ports[idx].membase != NULL)
1703                                 break;
1704
1705         co->index = idx;
1706
1707         return ports + idx;
1708 }
1709
1710 /**
1711  *      uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1712  *      @options: pointer to option string
1713  *      @baud: pointer to an 'int' variable for the baud rate.
1714  *      @parity: pointer to an 'int' variable for the parity.
1715  *      @bits: pointer to an 'int' variable for the number of data bits.
1716  *      @flow: pointer to an 'int' variable for the flow control character.
1717  *
1718  *      uart_parse_options decodes a string containing the serial console
1719  *      options.  The format of the string is <baud><parity><bits><flow>,
1720  *      eg: 115200n8r
1721  */
1722 void
1723 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1724 {
1725         char *s = options;
1726
1727         *baud = simple_strtoul(s, NULL, 10);
1728         while (*s >= '0' && *s <= '9')
1729                 s++;
1730         if (*s)
1731                 *parity = *s++;
1732         if (*s)
1733                 *bits = *s++ - '0';
1734         if (*s)
1735                 *flow = *s;
1736 }
1737 EXPORT_SYMBOL_GPL(uart_parse_options);
1738
1739 struct baud_rates {
1740         unsigned int rate;
1741         unsigned int cflag;
1742 };
1743
1744 static const struct baud_rates baud_rates[] = {
1745         { 921600, B921600 },
1746         { 460800, B460800 },
1747         { 230400, B230400 },
1748         { 115200, B115200 },
1749         {  57600, B57600  },
1750         {  38400, B38400  },
1751         {  19200, B19200  },
1752         {   9600, B9600   },
1753         {   4800, B4800   },
1754         {   2400, B2400   },
1755         {   1200, B1200   },
1756         {      0, B38400  }
1757 };
1758
1759 /**
1760  *      uart_set_options - setup the serial console parameters
1761  *      @port: pointer to the serial ports uart_port structure
1762  *      @co: console pointer
1763  *      @baud: baud rate
1764  *      @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1765  *      @bits: number of data bits
1766  *      @flow: flow control character - 'r' (rts)
1767  */
1768 int
1769 uart_set_options(struct uart_port *port, struct console *co,
1770                  int baud, int parity, int bits, int flow)
1771 {
1772         struct ktermios termios;
1773         static struct ktermios dummy;
1774         int i;
1775
1776         /*
1777          * Ensure that the serial console lock is initialised
1778          * early.
1779          */
1780         spin_lock_init(&port->lock);
1781         lockdep_set_class(&port->lock, &port_lock_key);
1782
1783         memset(&termios, 0, sizeof(struct ktermios));
1784
1785         termios.c_cflag = CREAD | HUPCL | CLOCAL;
1786
1787         /*
1788          * Construct a cflag setting.
1789          */
1790         for (i = 0; baud_rates[i].rate; i++)
1791                 if (baud_rates[i].rate <= baud)
1792                         break;
1793
1794         termios.c_cflag |= baud_rates[i].cflag;
1795
1796         if (bits == 7)
1797                 termios.c_cflag |= CS7;
1798         else
1799                 termios.c_cflag |= CS8;
1800
1801         switch (parity) {
1802         case 'o': case 'O':
1803                 termios.c_cflag |= PARODD;
1804                 /*fall through*/
1805         case 'e': case 'E':
1806                 termios.c_cflag |= PARENB;
1807                 break;
1808         }
1809
1810         if (flow == 'r')
1811                 termios.c_cflag |= CRTSCTS;
1812
1813         /*
1814          * some uarts on other side don't support no flow control.
1815          * So we set * DTR in host uart to make them happy
1816          */
1817         port->mctrl |= TIOCM_DTR;
1818
1819         port->ops->set_termios(port, &termios, &dummy);
1820         /*
1821          * Allow the setting of the UART parameters with a NULL console
1822          * too:
1823          */
1824         if (co)
1825                 co->cflag = termios.c_cflag;
1826
1827         return 0;
1828 }
1829 EXPORT_SYMBOL_GPL(uart_set_options);
1830 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1831
1832 /**
1833  * uart_change_pm - set power state of the port
1834  *
1835  * @state: port descriptor
1836  * @pm_state: new state
1837  *
1838  * Locking: port->mutex has to be held
1839  */
1840 static void uart_change_pm(struct uart_state *state, int pm_state)
1841 {
1842         struct uart_port *port = state->uart_port;
1843
1844         if (state->pm_state != pm_state) {
1845                 if (port->ops->pm)
1846                         port->ops->pm(port, pm_state, state->pm_state);
1847                 state->pm_state = pm_state;
1848         }
1849 }
1850
1851 struct uart_match {
1852         struct uart_port *port;
1853         struct uart_driver *driver;
1854 };
1855
1856 static int serial_match_port(struct device *dev, void *data)
1857 {
1858         struct uart_match *match = data;
1859         struct tty_driver *tty_drv = match->driver->tty_driver;
1860         dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1861                 match->port->line;
1862
1863         return dev->devt == devt; /* Actually, only one tty per port */
1864 }
1865
1866 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1867 {
1868         struct uart_state *state = drv->state + uport->line;
1869         struct tty_port *port = &state->port;
1870         struct device *tty_dev;
1871         struct uart_match match = {uport, drv};
1872
1873         mutex_lock(&port->mutex);
1874
1875         tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1876         if (device_may_wakeup(tty_dev)) {
1877                 if (!enable_irq_wake(uport->irq))
1878                         uport->irq_wake = 1;
1879                 put_device(tty_dev);
1880                 mutex_unlock(&port->mutex);
1881                 return 0;
1882         }
1883         if (console_suspend_enabled || !uart_console(uport))
1884                 uport->suspended = 1;
1885
1886         if (port->flags & ASYNC_INITIALIZED) {
1887                 const struct uart_ops *ops = uport->ops;
1888                 int tries;
1889
1890                 if (console_suspend_enabled || !uart_console(uport)) {
1891                         set_bit(ASYNCB_SUSPENDED, &port->flags);
1892                         clear_bit(ASYNCB_INITIALIZED, &port->flags);
1893
1894                         spin_lock_irq(&uport->lock);
1895                         ops->stop_tx(uport);
1896                         ops->set_mctrl(uport, 0);
1897                         ops->stop_rx(uport);
1898                         spin_unlock_irq(&uport->lock);
1899                 }
1900
1901                 /*
1902                  * Wait for the transmitter to empty.
1903                  */
1904                 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1905                         msleep(10);
1906                 if (!tries)
1907                         printk(KERN_ERR "%s%s%s%d: Unable to drain "
1908                                         "transmitter\n",
1909                                uport->dev ? dev_name(uport->dev) : "",
1910                                uport->dev ? ": " : "",
1911                                drv->dev_name,
1912                                drv->tty_driver->name_base + uport->line);
1913
1914                 if (console_suspend_enabled || !uart_console(uport))
1915                         ops->shutdown(uport);
1916         }
1917
1918         /*
1919          * Disable the console device before suspending.
1920          */
1921         if (console_suspend_enabled && uart_console(uport))
1922                 console_stop(uport->cons);
1923
1924         if (console_suspend_enabled || !uart_console(uport))
1925                 uart_change_pm(state, 3);
1926
1927         mutex_unlock(&port->mutex);
1928
1929         return 0;
1930 }
1931
1932 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1933 {
1934         struct uart_state *state = drv->state + uport->line;
1935         struct tty_port *port = &state->port;
1936         struct device *tty_dev;
1937         struct uart_match match = {uport, drv};
1938         struct ktermios termios;
1939
1940         mutex_lock(&port->mutex);
1941
1942         tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1943         if (!uport->suspended && device_may_wakeup(tty_dev)) {
1944                 if (uport->irq_wake) {
1945                         disable_irq_wake(uport->irq);
1946                         uport->irq_wake = 0;
1947                 }
1948                 mutex_unlock(&port->mutex);
1949                 return 0;
1950         }
1951         uport->suspended = 0;
1952
1953         /*
1954          * Re-enable the console device after suspending.
1955          */
1956         if (uart_console(uport)) {
1957                 /*
1958                  * First try to use the console cflag setting.
1959                  */
1960                 memset(&termios, 0, sizeof(struct ktermios));
1961                 termios.c_cflag = uport->cons->cflag;
1962
1963                 /*
1964                  * If that's unset, use the tty termios setting.
1965                  */
1966                 if (port->tty && port->tty->termios && termios.c_cflag == 0)
1967                         termios = *(port->tty->termios);
1968
1969                 if (console_suspend_enabled)
1970                         uart_change_pm(state, 0);
1971                 if (uport->type != PORT_TEGRA)
1972                         uport->ops->set_termios(uport, &termios, NULL);
1973                 if (console_suspend_enabled)
1974                         console_start(uport->cons);
1975         }
1976
1977         if (port->flags & ASYNC_SUSPENDED) {
1978                 const struct uart_ops *ops = uport->ops;
1979                 int ret;
1980
1981                 uart_change_pm(state, 0);
1982                 spin_lock_irq(&uport->lock);
1983                 ops->set_mctrl(uport, 0);
1984                 spin_unlock_irq(&uport->lock);
1985                 if (console_suspend_enabled || !uart_console(uport)) {
1986                         /* Protected by port mutex for now */
1987                         struct tty_struct *tty = port->tty;
1988                         ret = ops->startup(uport);
1989                         if (ret == 0) {
1990                                 if (tty)
1991                                         uart_change_speed(tty, state, NULL);
1992                                 spin_lock_irq(&uport->lock);
1993                                 ops->set_mctrl(uport, uport->mctrl);
1994                                 ops->start_tx(uport);
1995                                 spin_unlock_irq(&uport->lock);
1996                                 set_bit(ASYNCB_INITIALIZED, &port->flags);
1997                         } else {
1998                                 /*
1999                                  * Failed to resume - maybe hardware went away?
2000                                  * Clear the "initialized" flag so we won't try
2001                                  * to call the low level drivers shutdown method.
2002                                  */
2003                                 uart_shutdown(tty, state);
2004                         }
2005                 }
2006
2007                 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2008         }
2009
2010         mutex_unlock(&port->mutex);
2011
2012         return 0;
2013 }
2014
2015 static inline void
2016 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2017 {
2018         char address[64];
2019
2020         switch (port->iotype) {
2021         case UPIO_PORT:
2022                 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2023                 break;
2024         case UPIO_HUB6:
2025                 snprintf(address, sizeof(address),
2026                          "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2027                 break;
2028         case UPIO_MEM:
2029         case UPIO_MEM32:
2030         case UPIO_AU:
2031         case UPIO_TSI:
2032                 snprintf(address, sizeof(address),
2033                          "MMIO 0x%llx", (unsigned long long)port->mapbase);
2034                 break;
2035         default:
2036                 strlcpy(address, "*unknown*", sizeof(address));
2037                 break;
2038         }
2039
2040         printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2041                port->dev ? dev_name(port->dev) : "",
2042                port->dev ? ": " : "",
2043                drv->dev_name,
2044                drv->tty_driver->name_base + port->line,
2045                address, port->irq, uart_type(port));
2046 }
2047
2048 static void
2049 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2050                     struct uart_port *port)
2051 {
2052         unsigned int flags;
2053
2054         /*
2055          * If there isn't a port here, don't do anything further.
2056          */
2057         if (!port->iobase && !port->mapbase && !port->membase)
2058                 return;
2059
2060         /*
2061          * Now do the auto configuration stuff.  Note that config_port
2062          * is expected to claim the resources and map the port for us.
2063          */
2064         flags = 0;
2065         if (port->flags & UPF_AUTO_IRQ)
2066                 flags |= UART_CONFIG_IRQ;
2067         if (port->flags & UPF_BOOT_AUTOCONF) {
2068                 if (!(port->flags & UPF_FIXED_TYPE)) {
2069                         port->type = PORT_UNKNOWN;
2070                         flags |= UART_CONFIG_TYPE;
2071                 }
2072                 port->ops->config_port(port, flags);
2073         }
2074
2075         if (port->type != PORT_UNKNOWN) {
2076                 unsigned long flags;
2077
2078                 uart_report_port(drv, port);
2079
2080                 /* Power up port for set_mctrl() */
2081                 uart_change_pm(state, 0);
2082
2083                 /*
2084                  * Ensure that the modem control lines are de-activated.
2085                  * keep the DTR setting that is set in uart_set_options()
2086                  * We probably don't need a spinlock around this, but
2087                  */
2088                 spin_lock_irqsave(&port->lock, flags);
2089                 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2090                 spin_unlock_irqrestore(&port->lock, flags);
2091
2092                 /*
2093                  * If this driver supports console, and it hasn't been
2094                  * successfully registered yet, try to re-register it.
2095                  * It may be that the port was not available.
2096                  */
2097                 if (port->cons && !(port->cons->flags & CON_ENABLED))
2098                         register_console(port->cons);
2099
2100                 /*
2101                  * Power down all ports by default, except the
2102                  * console if we have one.
2103                  */
2104                 if (!uart_console(port))
2105                         uart_change_pm(state, 3);
2106         }
2107 }
2108
2109 #ifdef CONFIG_CONSOLE_POLL
2110
2111 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2112 {
2113         struct uart_driver *drv = driver->driver_state;
2114         struct uart_state *state = drv->state + line;
2115         struct uart_port *port;
2116         int baud = 9600;
2117         int bits = 8;
2118         int parity = 'n';
2119         int flow = 'n';
2120
2121         if (!state || !state->uart_port)
2122                 return -1;
2123
2124         port = state->uart_port;
2125         if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2126                 return -1;
2127
2128         if (options) {
2129                 uart_parse_options(options, &baud, &parity, &bits, &flow);
2130                 return uart_set_options(port, NULL, baud, parity, bits, flow);
2131         }
2132
2133         return 0;
2134 }
2135
2136 static int uart_poll_get_char(struct tty_driver *driver, int line)
2137 {
2138         struct uart_driver *drv = driver->driver_state;
2139         struct uart_state *state = drv->state + line;
2140         struct uart_port *port;
2141
2142         if (!state || !state->uart_port)
2143                 return -1;
2144
2145         port = state->uart_port;
2146         return port->ops->poll_get_char(port);
2147 }
2148
2149 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2150 {
2151         struct uart_driver *drv = driver->driver_state;
2152         struct uart_state *state = drv->state + line;
2153         struct uart_port *port;
2154
2155         if (!state || !state->uart_port)
2156                 return;
2157
2158         port = state->uart_port;
2159         port->ops->poll_put_char(port, ch);
2160 }
2161 #endif
2162
2163 static const struct tty_operations uart_ops = {
2164         .open           = uart_open,
2165         .close          = uart_close,
2166         .write          = uart_write,
2167         .put_char       = uart_put_char,
2168         .flush_chars    = uart_flush_chars,
2169         .write_room     = uart_write_room,
2170         .chars_in_buffer= uart_chars_in_buffer,
2171         .flush_buffer   = uart_flush_buffer,
2172         .ioctl          = uart_ioctl,
2173         .throttle       = uart_throttle,
2174         .unthrottle     = uart_unthrottle,
2175         .send_xchar     = uart_send_xchar,
2176         .set_termios    = uart_set_termios,
2177         .set_ldisc      = uart_set_ldisc,
2178         .stop           = uart_stop,
2179         .start          = uart_start,
2180         .hangup         = uart_hangup,
2181         .break_ctl      = uart_break_ctl,
2182         .wait_until_sent= uart_wait_until_sent,
2183 #ifdef CONFIG_PROC_FS
2184         .proc_fops      = &uart_proc_fops,
2185 #endif
2186         .tiocmget       = uart_tiocmget,
2187         .tiocmset       = uart_tiocmset,
2188         .get_icount     = uart_get_icount,
2189 #ifdef CONFIG_CONSOLE_POLL
2190         .poll_init      = uart_poll_init,
2191         .poll_get_char  = uart_poll_get_char,
2192         .poll_put_char  = uart_poll_put_char,
2193 #endif
2194 };
2195
2196 static const struct tty_port_operations uart_port_ops = {
2197         .activate       = uart_port_activate,
2198         .shutdown       = uart_port_shutdown,
2199         .carrier_raised = uart_carrier_raised,
2200         .dtr_rts        = uart_dtr_rts,
2201 };
2202
2203 /**
2204  *      uart_register_driver - register a driver with the uart core layer
2205  *      @drv: low level driver structure
2206  *
2207  *      Register a uart driver with the core driver.  We in turn register
2208  *      with the tty layer, and initialise the core driver per-port state.
2209  *
2210  *      We have a proc file in /proc/tty/driver which is named after the
2211  *      normal driver.
2212  *
2213  *      drv->port should be NULL, and the per-port structures should be
2214  *      registered using uart_add_one_port after this call has succeeded.
2215  */
2216 int uart_register_driver(struct uart_driver *drv)
2217 {
2218         struct tty_driver *normal;
2219         int i, retval;
2220
2221         BUG_ON(drv->state);
2222
2223         /*
2224          * Maybe we should be using a slab cache for this, especially if
2225          * we have a large number of ports to handle.
2226          */
2227         drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2228         if (!drv->state)
2229                 goto out;
2230
2231         normal = alloc_tty_driver(drv->nr);
2232         if (!normal)
2233                 goto out_kfree;
2234
2235         drv->tty_driver = normal;
2236
2237         normal->driver_name     = drv->driver_name;
2238         normal->name            = drv->dev_name;
2239         normal->major           = drv->major;
2240         normal->minor_start     = drv->minor;
2241         normal->type            = TTY_DRIVER_TYPE_SERIAL;
2242         normal->subtype         = SERIAL_TYPE_NORMAL;
2243         normal->init_termios    = tty_std_termios;
2244         normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2245         normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2246         normal->flags           = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2247         normal->driver_state    = drv;
2248         tty_set_operations(normal, &uart_ops);
2249
2250         /*
2251          * Initialise the UART state(s).
2252          */
2253         for (i = 0; i < drv->nr; i++) {
2254                 struct uart_state *state = drv->state + i;
2255                 struct tty_port *port = &state->port;
2256
2257                 tty_port_init(port);
2258                 port->ops = &uart_port_ops;
2259                 port->close_delay     = HZ / 2; /* .5 seconds */
2260                 port->closing_wait    = 30 * HZ;/* 30 seconds */
2261         }
2262
2263         retval = tty_register_driver(normal);
2264         if (retval >= 0)
2265                 return retval;
2266
2267         put_tty_driver(normal);
2268 out_kfree:
2269         kfree(drv->state);
2270 out:
2271         return -ENOMEM;
2272 }
2273
2274 /**
2275  *      uart_unregister_driver - remove a driver from the uart core layer
2276  *      @drv: low level driver structure
2277  *
2278  *      Remove all references to a driver from the core driver.  The low
2279  *      level driver must have removed all its ports via the
2280  *      uart_remove_one_port() if it registered them with uart_add_one_port().
2281  *      (ie, drv->port == NULL)
2282  */
2283 void uart_unregister_driver(struct uart_driver *drv)
2284 {
2285         struct tty_driver *p = drv->tty_driver;
2286         tty_unregister_driver(p);
2287         put_tty_driver(p);
2288         kfree(drv->state);
2289         drv->state = NULL;
2290         drv->tty_driver = NULL;
2291 }
2292
2293 struct tty_driver *uart_console_device(struct console *co, int *index)
2294 {
2295         struct uart_driver *p = co->data;
2296         *index = co->index;
2297         return p->tty_driver;
2298 }
2299
2300 /**
2301  *      uart_add_one_port - attach a driver-defined port structure
2302  *      @drv: pointer to the uart low level driver structure for this port
2303  *      @uport: uart port structure to use for this port.
2304  *
2305  *      This allows the driver to register its own uart_port structure
2306  *      with the core driver.  The main purpose is to allow the low
2307  *      level uart drivers to expand uart_port, rather than having yet
2308  *      more levels of structures.
2309  */
2310 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2311 {
2312         struct uart_state *state;
2313         struct tty_port *port;
2314         int ret = 0;
2315         struct device *tty_dev;
2316
2317         BUG_ON(in_interrupt());
2318
2319         if (uport->line >= drv->nr)
2320                 return -EINVAL;
2321
2322         state = drv->state + uport->line;
2323         port = &state->port;
2324
2325         mutex_lock(&port_mutex);
2326         mutex_lock(&port->mutex);
2327         if (state->uart_port) {
2328                 ret = -EINVAL;
2329                 goto out;
2330         }
2331
2332         state->uart_port = uport;
2333         state->pm_state = -1;
2334
2335         uport->cons = drv->cons;
2336         uport->state = state;
2337
2338         /*
2339          * If this port is a console, then the spinlock is already
2340          * initialised.
2341          */
2342         if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2343                 spin_lock_init(&uport->lock);
2344                 lockdep_set_class(&uport->lock, &port_lock_key);
2345         }
2346
2347         uart_configure_port(drv, state, uport);
2348
2349         /*
2350          * Register the port whether it's detected or not.  This allows
2351          * setserial to be used to alter this ports parameters.
2352          */
2353         tty_dev = tty_register_device(drv->tty_driver, uport->line, uport->dev);
2354         if (likely(!IS_ERR(tty_dev))) {
2355                 device_set_wakeup_capable(tty_dev, 1);
2356         } else {
2357                 printk(KERN_ERR "Cannot register tty device on line %d\n",
2358                        uport->line);
2359         }
2360
2361         /*
2362          * Ensure UPF_DEAD is not set.
2363          */
2364         uport->flags &= ~UPF_DEAD;
2365
2366  out:
2367         mutex_unlock(&port->mutex);
2368         mutex_unlock(&port_mutex);
2369
2370         return ret;
2371 }
2372
2373 /**
2374  *      uart_remove_one_port - detach a driver defined port structure
2375  *      @drv: pointer to the uart low level driver structure for this port
2376  *      @uport: uart port structure for this port
2377  *
2378  *      This unhooks (and hangs up) the specified port structure from the
2379  *      core driver.  No further calls will be made to the low-level code
2380  *      for this port.
2381  */
2382 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2383 {
2384         struct uart_state *state = drv->state + uport->line;
2385         struct tty_port *port = &state->port;
2386
2387         BUG_ON(in_interrupt());
2388
2389         if (state->uart_port != uport)
2390                 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2391                         state->uart_port, uport);
2392
2393         mutex_lock(&port_mutex);
2394
2395         /*
2396          * Mark the port "dead" - this prevents any opens from
2397          * succeeding while we shut down the port.
2398          */
2399         mutex_lock(&port->mutex);
2400         uport->flags |= UPF_DEAD;
2401         mutex_unlock(&port->mutex);
2402
2403         /*
2404          * Remove the devices from the tty layer
2405          */
2406         tty_unregister_device(drv->tty_driver, uport->line);
2407
2408         if (port->tty)
2409                 tty_vhangup(port->tty);
2410
2411         /*
2412          * Free the port IO and memory resources, if any.
2413          */
2414         if (uport->type != PORT_UNKNOWN)
2415                 uport->ops->release_port(uport);
2416
2417         /*
2418          * Indicate that there isn't a port here anymore.
2419          */
2420         uport->type = PORT_UNKNOWN;
2421
2422         state->uart_port = NULL;
2423         mutex_unlock(&port_mutex);
2424
2425         return 0;
2426 }
2427
2428 /*
2429  *      Are the two ports equivalent?
2430  */
2431 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2432 {
2433         if (port1->iotype != port2->iotype)
2434                 return 0;
2435
2436         switch (port1->iotype) {
2437         case UPIO_PORT:
2438                 return (port1->iobase == port2->iobase);
2439         case UPIO_HUB6:
2440                 return (port1->iobase == port2->iobase) &&
2441                        (port1->hub6   == port2->hub6);
2442         case UPIO_MEM:
2443         case UPIO_MEM32:
2444         case UPIO_AU:
2445         case UPIO_TSI:
2446                 return (port1->mapbase == port2->mapbase);
2447         }
2448         return 0;
2449 }
2450 EXPORT_SYMBOL(uart_match_port);
2451
2452 /**
2453  *      uart_handle_dcd_change - handle a change of carrier detect state
2454  *      @uport: uart_port structure for the open port
2455  *      @status: new carrier detect status, nonzero if active
2456  */
2457 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2458 {
2459         struct uart_state *state = uport->state;
2460         struct tty_port *port = &state->port;
2461         struct tty_ldisc *ld = tty_ldisc_ref(port->tty);
2462         struct pps_event_time ts;
2463
2464         if (ld && ld->ops->dcd_change)
2465                 pps_get_ts(&ts);
2466
2467         uport->icount.dcd++;
2468 #ifdef CONFIG_HARD_PPS
2469         if ((uport->flags & UPF_HARDPPS_CD) && status)
2470                 hardpps();
2471 #endif
2472
2473         if (port->flags & ASYNC_CHECK_CD) {
2474                 if (status)
2475                         wake_up_interruptible(&port->open_wait);
2476                 else if (port->tty)
2477                         tty_hangup(port->tty);
2478         }
2479
2480         if (ld && ld->ops->dcd_change)
2481                 ld->ops->dcd_change(port->tty, status, &ts);
2482         if (ld)
2483                 tty_ldisc_deref(ld);
2484 }
2485 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2486
2487 /**
2488  *      uart_handle_cts_change - handle a change of clear-to-send state
2489  *      @uport: uart_port structure for the open port
2490  *      @status: new clear to send status, nonzero if active
2491  */
2492 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2493 {
2494         struct tty_port *port = &uport->state->port;
2495         struct tty_struct *tty = port->tty;
2496
2497         uport->icount.cts++;
2498
2499         if (port->flags & ASYNC_CTS_FLOW) {
2500                 if (tty->hw_stopped) {
2501                         if (status) {
2502                                 tty->hw_stopped = 0;
2503                                 uport->ops->start_tx(uport);
2504                                 uart_write_wakeup(uport);
2505                         }
2506                 } else {
2507                         if (!status) {
2508                                 tty->hw_stopped = 1;
2509                                 uport->ops->stop_tx(uport);
2510                         }
2511                 }
2512         }
2513 }
2514 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2515
2516 /**
2517  * uart_insert_char - push a char to the uart layer
2518  *
2519  * User is responsible to call tty_flip_buffer_push when they are done with
2520  * insertion.
2521  *
2522  * @port: corresponding port
2523  * @status: state of the serial port RX buffer (LSR for 8250)
2524  * @overrun: mask of overrun bits in @status
2525  * @ch: character to push
2526  * @flag: flag for the character (see TTY_NORMAL and friends)
2527  */
2528 void uart_insert_char(struct uart_port *port, unsigned int status,
2529                  unsigned int overrun, unsigned int ch, unsigned int flag)
2530 {
2531         struct tty_struct *tty = port->state->port.tty;
2532
2533         if ((status & port->ignore_status_mask & ~overrun) == 0)
2534                 tty_insert_flip_char(tty, ch, flag);
2535
2536         /*
2537          * Overrun is special.  Since it's reported immediately,
2538          * it doesn't affect the current character.
2539          */
2540         if (status & ~port->ignore_status_mask & overrun)
2541                 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
2542 }
2543 EXPORT_SYMBOL_GPL(uart_insert_char);
2544
2545 EXPORT_SYMBOL(uart_write_wakeup);
2546 EXPORT_SYMBOL(uart_register_driver);
2547 EXPORT_SYMBOL(uart_unregister_driver);
2548 EXPORT_SYMBOL(uart_suspend_port);
2549 EXPORT_SYMBOL(uart_resume_port);
2550 EXPORT_SYMBOL(uart_add_one_port);
2551 EXPORT_SYMBOL(uart_remove_one_port);
2552
2553 MODULE_DESCRIPTION("Serial driver core");
2554 MODULE_LICENSE("GPL");