cbbd11a0722f8b5793fc1dbefd6b54af9d178273
[android-sdk/kernel-video.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>
37 #include <asm/irq.h>
38 #include <asm/uaccess.h>
40 /*
41  * This is used to lock changes in serial line configuration.
42  */
43 static DEFINE_MUTEX(port_mutex);
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;
51 #define HIGH_BITS_OFFSET        ((sizeof(long)-sizeof(int))*8)
53 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
54                                         struct ktermios *old_termios);
55 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
56 static void uart_change_pm(struct uart_state *state, int pm_state);
58 static void uart_port_shutdown(struct tty_port *port);
60 /*
61  * This routine is used by the interrupt handler to schedule processing in
62  * the software interrupt portion of the driver.
63  */
64 void uart_write_wakeup(struct uart_port *port)
65 {
66         struct uart_state *state = port->state;
67         /*
68          * This means you called this function _after_ the port was
69          * closed.  No cookie for you.
70          */
71         BUG_ON(!state);
72         tty_wakeup(state->port.tty);
73 }
75 static void uart_stop(struct tty_struct *tty)
76 {
77         struct uart_state *state = tty->driver_data;
78         struct uart_port *port = state->uart_port;
79         unsigned long flags;
81         spin_lock_irqsave(&port->lock, flags);
82         port->ops->stop_tx(port);
83         spin_unlock_irqrestore(&port->lock, flags);
84 }
86 static void __uart_start(struct tty_struct *tty)
87 {
88         struct uart_state *state = tty->driver_data;
89         struct uart_port *port = state->uart_port;
91         if (port->ops->wake_peer)
92                 port->ops->wake_peer(port);
94         if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
95             !tty->stopped && !tty->hw_stopped)
96                 port->ops->start_tx(port);
97 }
99 static void uart_start(struct tty_struct *tty)
101         struct uart_state *state = tty->driver_data;
102         struct uart_port *port = state->uart_port;
103         unsigned long flags;
105         spin_lock_irqsave(&port->lock, flags);
106         __uart_start(tty);
107         spin_unlock_irqrestore(&port->lock, flags);
110 static inline void
111 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
113         unsigned long flags;
114         unsigned int old;
116         spin_lock_irqsave(&port->lock, flags);
117         old = port->mctrl;
118         port->mctrl = (old & ~clear) | set;
119         if (old != port->mctrl)
120                 port->ops->set_mctrl(port, port->mctrl);
121         spin_unlock_irqrestore(&port->lock, flags);
124 #define uart_set_mctrl(port, set)       uart_update_mctrl(port, set, 0)
125 #define uart_clear_mctrl(port, clear)   uart_update_mctrl(port, 0, clear)
127 /*
128  * Startup the port.  This will be called once per open.  All calls
129  * will be serialised by the per-port mutex.
130  */
131 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
132                 int init_hw)
134         struct uart_port *uport = state->uart_port;
135         struct tty_port *port = &state->port;
136         unsigned long page;
137         int retval = 0;
139         if (uport->type == PORT_UNKNOWN)
140                 return 1;
142         /*
143          * Initialise and allocate the transmit and temporary
144          * buffer.
145          */
146         if (!state->xmit.buf) {
147                 /* This is protected by the per port mutex */
148                 page = get_zeroed_page(GFP_KERNEL);
149                 if (!page)
150                         return -ENOMEM;
152                 state->xmit.buf = (unsigned char *) page;
153                 uart_circ_clear(&state->xmit);
154         }
156         retval = uport->ops->startup(uport);
157         if (retval == 0) {
158                 if (uart_console(uport) && uport->cons->cflag) {
159                         tty->termios.c_cflag = uport->cons->cflag;
160                         uport->cons->cflag = 0;
161                 }
162                 /*
163                  * Initialise the hardware port settings.
164                  */
165                 uart_change_speed(tty, state, NULL);
167                 if (init_hw) {
168                         /*
169                          * Setup the RTS and DTR signals once the
170                          * port is open and ready to respond.
171                          */
172                         if (tty->termios.c_cflag & CBAUD)
173                                 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
174                 }
176                 if (tty_port_cts_enabled(port)) {
177                         spin_lock_irq(&uport->lock);
178                         if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
179                                 tty->hw_stopped = 1;
180                         spin_unlock_irq(&uport->lock);
181                 }
182         }
184         /*
185          * This is to allow setserial on this port. People may want to set
186          * port/irq/type and then reconfigure the port properly if it failed
187          * now.
188          */
189         if (retval && capable(CAP_SYS_ADMIN))
190                 return 1;
192         return retval;
195 static int uart_startup(struct tty_struct *tty, struct uart_state *state,
196                 int init_hw)
198         struct tty_port *port = &state->port;
199         int retval;
201         if (port->flags & ASYNC_INITIALIZED)
202                 return 0;
204         /*
205          * Set the TTY IO error marker - we will only clear this
206          * once we have successfully opened the port.
207          */
208         set_bit(TTY_IO_ERROR, &tty->flags);
210         retval = uart_port_startup(tty, state, init_hw);
211         if (!retval) {
212                 set_bit(ASYNCB_INITIALIZED, &port->flags);
213                 clear_bit(TTY_IO_ERROR, &tty->flags);
214         } else if (retval > 0)
215                 retval = 0;
217         return retval;
220 /*
221  * This routine will shutdown a serial port; interrupts are disabled, and
222  * DTR is dropped if the hangup on close termio flag is on.  Calls to
223  * uart_shutdown are serialised by the per-port semaphore.
224  */
225 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
227         struct uart_port *uport = state->uart_port;
228         struct tty_port *port = &state->port;
230         /*
231          * Set the TTY IO error marker
232          */
233         if (tty)
234                 set_bit(TTY_IO_ERROR, &tty->flags);
236         if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
237                 /*
238                  * Turn off DTR and RTS early.
239                  */
240                 if (!tty || (tty->termios.c_cflag & HUPCL))
241                         uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
243                 uart_port_shutdown(port);
244         }
246         /*
247          * It's possible for shutdown to be called after suspend if we get
248          * a DCD drop (hangup) at just the right time.  Clear suspended bit so
249          * we don't try to resume a port that has been shutdown.
250          */
251         clear_bit(ASYNCB_SUSPENDED, &port->flags);
253         /*
254          * Free the transmit buffer page.
255          */
256         if (state->xmit.buf) {
257                 free_page((unsigned long)state->xmit.buf);
258                 state->xmit.buf = NULL;
259         }
262 /**
263  *      uart_update_timeout - update per-port FIFO timeout.
264  *      @port:  uart_port structure describing the port
265  *      @cflag: termios cflag value
266  *      @baud:  speed of the port
267  *
268  *      Set the port FIFO timeout value.  The @cflag value should
269  *      reflect the actual hardware settings.
270  */
271 void
272 uart_update_timeout(struct uart_port *port, unsigned int cflag,
273                     unsigned int baud)
275         unsigned int bits;
277         /* byte size and parity */
278         switch (cflag & CSIZE) {
279         case CS5:
280                 bits = 7;
281                 break;
282         case CS6:
283                 bits = 8;
284                 break;
285         case CS7:
286                 bits = 9;
287                 break;
288         default:
289                 bits = 10;
290                 break; /* CS8 */
291         }
293         if (cflag & CSTOPB)
294                 bits++;
295         if (cflag & PARENB)
296                 bits++;
298         /*
299          * The total number of bits to be transmitted in the fifo.
300          */
301         bits = bits * port->fifosize;
303         /*
304          * Figure the timeout to send the above number of bits.
305          * Add .02 seconds of slop
306          */
307         port->timeout = (HZ * bits) / baud + HZ/50;
310 EXPORT_SYMBOL(uart_update_timeout);
312 /**
313  *      uart_get_baud_rate - return baud rate for a particular port
314  *      @port: uart_port structure describing the port in question.
315  *      @termios: desired termios settings.
316  *      @old: old termios (or NULL)
317  *      @min: minimum acceptable baud rate
318  *      @max: maximum acceptable baud rate
319  *
320  *      Decode the termios structure into a numeric baud rate,
321  *      taking account of the magic 38400 baud rate (with spd_*
322  *      flags), and mapping the %B0 rate to 9600 baud.
323  *
324  *      If the new baud rate is invalid, try the old termios setting.
325  *      If it's still invalid, we try 9600 baud.
326  *
327  *      Update the @termios structure to reflect the baud rate
328  *      we're actually going to be using. Don't do this for the case
329  *      where B0 is requested ("hang up").
330  */
331 unsigned int
332 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
333                    struct ktermios *old, unsigned int min, unsigned int max)
335         unsigned int try, baud, altbaud = 38400;
336         int hung_up = 0;
337         upf_t flags = port->flags & UPF_SPD_MASK;
339         if (flags == UPF_SPD_HI)
340                 altbaud = 57600;
341         else if (flags == UPF_SPD_VHI)
342                 altbaud = 115200;
343         else if (flags == UPF_SPD_SHI)
344                 altbaud = 230400;
345         else if (flags == UPF_SPD_WARP)
346                 altbaud = 460800;
348         for (try = 0; try < 2; try++) {
349                 baud = tty_termios_baud_rate(termios);
351                 /*
352                  * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
353                  * Die! Die! Die!
354                  */
355                 if (baud == 38400)
356                         baud = altbaud;
358                 /*
359                  * Special case: B0 rate.
360                  */
361                 if (baud == 0) {
362                         hung_up = 1;
363                         baud = 9600;
364                 }
366                 if (baud >= min && baud <= max)
367                         return baud;
369                 /*
370                  * Oops, the quotient was zero.  Try again with
371                  * the old baud rate if possible.
372                  */
373                 termios->c_cflag &= ~CBAUD;
374                 if (old) {
375                         baud = tty_termios_baud_rate(old);
376                         if (!hung_up)
377                                 tty_termios_encode_baud_rate(termios,
378                                                                 baud, baud);
379                         old = NULL;
380                         continue;
381                 }
383                 /*
384                  * As a last resort, if the range cannot be met then clip to
385                  * the nearest chip supported rate.
386                  */
387                 if (!hung_up) {
388                         if (baud <= min)
389                                 tty_termios_encode_baud_rate(termios,
390                                                         min + 1, min + 1);
391                         else
392                                 tty_termios_encode_baud_rate(termios,
393                                                         max - 1, max - 1);
394                 }
395         }
396         /* Should never happen */
397         WARN_ON(1);
398         return 0;
401 EXPORT_SYMBOL(uart_get_baud_rate);
403 /**
404  *      uart_get_divisor - return uart clock divisor
405  *      @port: uart_port structure describing the port.
406  *      @baud: desired baud rate
407  *
408  *      Calculate the uart clock divisor for the port.
409  */
410 unsigned int
411 uart_get_divisor(struct uart_port *port, unsigned int baud)
413         unsigned int quot;
415         /*
416          * Old custom speed handling.
417          */
418         if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
419                 quot = port->custom_divisor;
420         else
421                 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
423         return quot;
426 EXPORT_SYMBOL(uart_get_divisor);
428 /* FIXME: Consistent locking policy */
429 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
430                                         struct ktermios *old_termios)
432         struct tty_port *port = &state->port;
433         struct uart_port *uport = state->uart_port;
434         struct ktermios *termios;
436         /*
437          * If we have no tty, termios, or the port does not exist,
438          * then we can't set the parameters for this port.
439          */
440         if (!tty || uport->type == PORT_UNKNOWN)
441                 return;
443         termios = &tty->termios;
445         /*
446          * Set flags based on termios cflag
447          */
448         if (termios->c_cflag & CRTSCTS)
449                 set_bit(ASYNCB_CTS_FLOW, &port->flags);
450         else
451                 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
453         if (termios->c_cflag & CLOCAL)
454                 clear_bit(ASYNCB_CHECK_CD, &port->flags);
455         else
456                 set_bit(ASYNCB_CHECK_CD, &port->flags);
458         uport->ops->set_termios(uport, termios, old_termios);
461 static inline int __uart_put_char(struct uart_port *port,
462                                 struct circ_buf *circ, unsigned char c)
464         unsigned long flags;
465         int ret = 0;
467         if (!circ->buf)
468                 return 0;
470         spin_lock_irqsave(&port->lock, flags);
471         if (uart_circ_chars_free(circ) != 0) {
472                 circ->buf[circ->head] = c;
473                 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
474                 ret = 1;
475         }
476         spin_unlock_irqrestore(&port->lock, flags);
477         return ret;
480 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
482         struct uart_state *state = tty->driver_data;
484         return __uart_put_char(state->uart_port, &state->xmit, ch);
487 static void uart_flush_chars(struct tty_struct *tty)
489         uart_start(tty);
492 static int uart_write(struct tty_struct *tty,
493                                         const unsigned char *buf, int count)
495         struct uart_state *state = tty->driver_data;
496         struct uart_port *port;
497         struct circ_buf *circ;
498         unsigned long flags;
499         int c, ret = 0;
501         /*
502          * This means you called this function _after_ the port was
503          * closed.  No cookie for you.
504          */
505         if (!state) {
506                 WARN_ON(1);
507                 return -EL3HLT;
508         }
510         port = state->uart_port;
511         circ = &state->xmit;
513         if (!circ->buf)
514                 return 0;
516         spin_lock_irqsave(&port->lock, flags);
517         while (1) {
518                 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
519                 if (count < c)
520                         c = count;
521                 if (c <= 0)
522                         break;
523                 memcpy(circ->buf + circ->head, buf, c);
524                 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
525                 buf += c;
526                 count -= c;
527                 ret += c;
528         }
529         spin_unlock_irqrestore(&port->lock, flags);
531         uart_start(tty);
532         return ret;
535 static int uart_write_room(struct tty_struct *tty)
537         struct uart_state *state = tty->driver_data;
538         unsigned long flags;
539         int ret;
541         spin_lock_irqsave(&state->uart_port->lock, flags);
542         ret = uart_circ_chars_free(&state->xmit);
543         spin_unlock_irqrestore(&state->uart_port->lock, flags);
544         return ret;
547 static int uart_chars_in_buffer(struct tty_struct *tty)
549         struct uart_state *state = tty->driver_data;
550         unsigned long flags;
551         int ret;
553         spin_lock_irqsave(&state->uart_port->lock, flags);
554         ret = uart_circ_chars_pending(&state->xmit);
555         spin_unlock_irqrestore(&state->uart_port->lock, flags);
556         return ret;
559 static void uart_flush_buffer(struct tty_struct *tty)
561         struct uart_state *state = tty->driver_data;
562         struct uart_port *port;
563         unsigned long flags;
565         /*
566          * This means you called this function _after_ the port was
567          * closed.  No cookie for you.
568          */
569         if (!state) {
570                 WARN_ON(1);
571                 return;
572         }
574         port = state->uart_port;
575         pr_debug("uart_flush_buffer(%d) called\n", tty->index);
577         spin_lock_irqsave(&port->lock, flags);
578         uart_circ_clear(&state->xmit);
579         if (port->ops->flush_buffer)
580                 port->ops->flush_buffer(port);
581         spin_unlock_irqrestore(&port->lock, flags);
582         tty_wakeup(tty);
585 /*
586  * This function is used to send a high-priority XON/XOFF character to
587  * the device
588  */
589 static void uart_send_xchar(struct tty_struct *tty, char ch)
591         struct uart_state *state = tty->driver_data;
592         struct uart_port *port = state->uart_port;
593         unsigned long flags;
595         if (port->ops->send_xchar)
596                 port->ops->send_xchar(port, ch);
597         else {
598                 port->x_char = ch;
599                 if (ch) {
600                         spin_lock_irqsave(&port->lock, flags);
601                         port->ops->start_tx(port);
602                         spin_unlock_irqrestore(&port->lock, flags);
603                 }
604         }
607 static void uart_throttle(struct tty_struct *tty)
609         struct uart_state *state = tty->driver_data;
610         struct uart_port *port = state->uart_port;
611         uint32_t mask = 0;
613         if (I_IXOFF(tty))
614                 mask |= UPF_SOFT_FLOW;
615         if (tty->termios.c_cflag & CRTSCTS)
616                 mask |= UPF_HARD_FLOW;
618         if (port->flags & mask) {
619                 port->ops->throttle(port);
620                 mask &= ~port->flags;
621         }
623         if (mask & UPF_SOFT_FLOW)
624                 uart_send_xchar(tty, STOP_CHAR(tty));
626         if (mask & UPF_HARD_FLOW)
627                 uart_clear_mctrl(port, TIOCM_RTS);
630 static void uart_unthrottle(struct tty_struct *tty)
632         struct uart_state *state = tty->driver_data;
633         struct uart_port *port = state->uart_port;
634         uint32_t mask = 0;
636         if (I_IXOFF(tty))
637                 mask |= UPF_SOFT_FLOW;
638         if (tty->termios.c_cflag & CRTSCTS)
639                 mask |= UPF_HARD_FLOW;
641         if (port->flags & mask) {
642                 port->ops->unthrottle(port);
643                 mask &= ~port->flags;
644         }
646         if (mask & UPF_SOFT_FLOW) {
647                 if (port->x_char)
648                         port->x_char = 0;
649                 else
650                         uart_send_xchar(tty, START_CHAR(tty));
651         }
653         if (mask & UPF_HARD_FLOW)
654                 uart_set_mctrl(port, TIOCM_RTS);
657 static void do_uart_get_info(struct tty_port *port,
658                         struct serial_struct *retinfo)
660         struct uart_state *state = container_of(port, struct uart_state, port);
661         struct uart_port *uport = state->uart_port;
663         memset(retinfo, 0, sizeof(*retinfo));
665         retinfo->type       = uport->type;
666         retinfo->line       = uport->line;
667         retinfo->port       = uport->iobase;
668         if (HIGH_BITS_OFFSET)
669                 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
670         retinfo->irq                = uport->irq;
671         retinfo->flags      = uport->flags;
672         retinfo->xmit_fifo_size  = uport->fifosize;
673         retinfo->baud_base          = uport->uartclk / 16;
674         retinfo->close_delay        = jiffies_to_msecs(port->close_delay) / 10;
675         retinfo->closing_wait    = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
676                                 ASYNC_CLOSING_WAIT_NONE :
677                                 jiffies_to_msecs(port->closing_wait) / 10;
678         retinfo->custom_divisor  = uport->custom_divisor;
679         retinfo->hub6       = uport->hub6;
680         retinfo->io_type         = uport->iotype;
681         retinfo->iomem_reg_shift = uport->regshift;
682         retinfo->iomem_base      = (void *)(unsigned long)uport->mapbase;
685 static void uart_get_info(struct tty_port *port,
686                         struct serial_struct *retinfo)
688         /* Ensure the state we copy is consistent and no hardware changes
689            occur as we go */
690         mutex_lock(&port->mutex);
691         do_uart_get_info(port, retinfo);
692         mutex_unlock(&port->mutex);
695 static int uart_get_info_user(struct tty_port *port,
696                          struct serial_struct __user *retinfo)
698         struct serial_struct tmp;
699         uart_get_info(port, &tmp);
701         if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
702                 return -EFAULT;
703         return 0;
706 static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
707                          struct uart_state *state,
708                          struct serial_struct *new_info)
710         struct uart_port *uport = state->uart_port;
711         unsigned long new_port;
712         unsigned int change_irq, change_port, closing_wait;
713         unsigned int old_custom_divisor, close_delay;
714         upf_t old_flags, new_flags;
715         int retval = 0;
717         new_port = new_info->port;
718         if (HIGH_BITS_OFFSET)
719                 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
721         new_info->irq = irq_canonicalize(new_info->irq);
722         close_delay = msecs_to_jiffies(new_info->close_delay * 10);
723         closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
724                         ASYNC_CLOSING_WAIT_NONE :
725                         msecs_to_jiffies(new_info->closing_wait * 10);
728         change_irq  = !(uport->flags & UPF_FIXED_PORT)
729                 && new_info->irq != uport->irq;
731         /*
732          * Since changing the 'type' of the port changes its resource
733          * allocations, we should treat type changes the same as
734          * IO port changes.
735          */
736         change_port = !(uport->flags & UPF_FIXED_PORT)
737                 && (new_port != uport->iobase ||
738                     (unsigned long)new_info->iomem_base != uport->mapbase ||
739                     new_info->hub6 != uport->hub6 ||
740                     new_info->io_type != uport->iotype ||
741                     new_info->iomem_reg_shift != uport->regshift ||
742                     new_info->type != uport->type);
744         old_flags = uport->flags;
745         new_flags = new_info->flags;
746         old_custom_divisor = uport->custom_divisor;
748         if (!capable(CAP_SYS_ADMIN)) {
749                 retval = -EPERM;
750                 if (change_irq || change_port ||
751                     (new_info->baud_base != uport->uartclk / 16) ||
752                     (close_delay != port->close_delay) ||
753                     (closing_wait != port->closing_wait) ||
754                     (new_info->xmit_fifo_size &&
755                      new_info->xmit_fifo_size != uport->fifosize) ||
756                     (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
757                         goto exit;
758                 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
759                                (new_flags & UPF_USR_MASK));
760                 uport->custom_divisor = new_info->custom_divisor;
761                 goto check_and_exit;
762         }
764         /*
765          * Ask the low level driver to verify the settings.
766          */
767         if (uport->ops->verify_port)
768                 retval = uport->ops->verify_port(uport, new_info);
770         if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
771             (new_info->baud_base < 9600))
772                 retval = -EINVAL;
774         if (retval)
775                 goto exit;
777         if (change_port || change_irq) {
778                 retval = -EBUSY;
780                 /*
781                  * Make sure that we are the sole user of this port.
782                  */
783                 if (tty_port_users(port) > 1)
784                         goto exit;
786                 /*
787                  * We need to shutdown the serial port at the old
788                  * port/type/irq combination.
789                  */
790                 uart_shutdown(tty, state);
791         }
793         if (change_port) {
794                 unsigned long old_iobase, old_mapbase;
795                 unsigned int old_type, old_iotype, old_hub6, old_shift;
797                 old_iobase = uport->iobase;
798                 old_mapbase = uport->mapbase;
799                 old_type = uport->type;
800                 old_hub6 = uport->hub6;
801                 old_iotype = uport->iotype;
802                 old_shift = uport->regshift;
804                 /*
805                  * Free and release old regions
806                  */
807                 if (old_type != PORT_UNKNOWN)
808                         uport->ops->release_port(uport);
810                 uport->iobase = new_port;
811                 uport->type = new_info->type;
812                 uport->hub6 = new_info->hub6;
813                 uport->iotype = new_info->io_type;
814                 uport->regshift = new_info->iomem_reg_shift;
815                 uport->mapbase = (unsigned long)new_info->iomem_base;
817                 /*
818                  * Claim and map the new regions
819                  */
820                 if (uport->type != PORT_UNKNOWN) {
821                         retval = uport->ops->request_port(uport);
822                 } else {
823                         /* Always success - Jean II */
824                         retval = 0;
825                 }
827                 /*
828                  * If we fail to request resources for the
829                  * new port, try to restore the old settings.
830                  */
831                 if (retval && old_type != PORT_UNKNOWN) {
832                         uport->iobase = old_iobase;
833                         uport->type = old_type;
834                         uport->hub6 = old_hub6;
835                         uport->iotype = old_iotype;
836                         uport->regshift = old_shift;
837                         uport->mapbase = old_mapbase;
838                         retval = uport->ops->request_port(uport);
839                         /*
840                          * If we failed to restore the old settings,
841                          * we fail like this.
842                          */
843                         if (retval)
844                                 uport->type = PORT_UNKNOWN;
846                         /*
847                          * We failed anyway.
848                          */
849                         retval = -EBUSY;
850                         /* Added to return the correct error -Ram Gupta */
851                         goto exit;
852                 }
853         }
855         if (change_irq)
856                 uport->irq      = new_info->irq;
857         if (!(uport->flags & UPF_FIXED_PORT))
858                 uport->uartclk  = new_info->baud_base * 16;
859         uport->flags            = (uport->flags & ~UPF_CHANGE_MASK) |
860                                  (new_flags & UPF_CHANGE_MASK);
861         uport->custom_divisor   = new_info->custom_divisor;
862         port->close_delay     = close_delay;
863         port->closing_wait    = closing_wait;
864         if (new_info->xmit_fifo_size)
865                 uport->fifosize = new_info->xmit_fifo_size;
866         if (port->tty)
867                 port->tty->low_latency =
868                         (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
870  check_and_exit:
871         retval = 0;
872         if (uport->type == PORT_UNKNOWN)
873                 goto exit;
874         if (port->flags & ASYNC_INITIALIZED) {
875                 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
876                     old_custom_divisor != uport->custom_divisor) {
877                         /*
878                          * If they're setting up a custom divisor or speed,
879                          * instead of clearing it, then bitch about it. No
880                          * need to rate-limit; it's CAP_SYS_ADMIN only.
881                          */
882                         if (uport->flags & UPF_SPD_MASK) {
883                                 char buf[64];
884                                 printk(KERN_NOTICE
885                                        "%s sets custom speed on %s. This "
886                                        "is deprecated.\n", current->comm,
887                                        tty_name(port->tty, buf));
888                         }
889                         uart_change_speed(tty, state, NULL);
890                 }
891         } else
892                 retval = uart_startup(tty, state, 1);
893  exit:
894         return retval;
897 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
898                          struct serial_struct __user *newinfo)
900         struct serial_struct new_serial;
901         struct tty_port *port = &state->port;
902         int retval;
904         if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
905                 return -EFAULT;
907         /*
908          * This semaphore protects port->count.  It is also
909          * very useful to prevent opens.  Also, take the
910          * port configuration semaphore to make sure that a
911          * module insertion/removal doesn't change anything
912          * under us.
913          */
914         mutex_lock(&port->mutex);
915         retval = uart_set_info(tty, port, state, &new_serial);
916         mutex_unlock(&port->mutex);
917         return retval;
920 /**
921  *      uart_get_lsr_info       -       get line status register info
922  *      @tty: tty associated with the UART
923  *      @state: UART being queried
924  *      @value: returned modem value
925  *
926  *      Note: uart_ioctl protects us against hangups.
927  */
928 static int uart_get_lsr_info(struct tty_struct *tty,
929                         struct uart_state *state, unsigned int __user *value)
931         struct uart_port *uport = state->uart_port;
932         unsigned int result;
934         result = uport->ops->tx_empty(uport);
936         /*
937          * If we're about to load something into the transmit
938          * register, we'll pretend the transmitter isn't empty to
939          * avoid a race condition (depending on when the transmit
940          * interrupt happens).
941          */
942         if (uport->x_char ||
943             ((uart_circ_chars_pending(&state->xmit) > 0) &&
944              !tty->stopped && !tty->hw_stopped))
945                 result &= ~TIOCSER_TEMT;
947         return put_user(result, value);
950 static int uart_tiocmget(struct tty_struct *tty)
952         struct uart_state *state = tty->driver_data;
953         struct tty_port *port = &state->port;
954         struct uart_port *uport = state->uart_port;
955         int result = -EIO;
957         mutex_lock(&port->mutex);
958         if (!(tty->flags & (1 << TTY_IO_ERROR))) {
959                 result = uport->mctrl;
960                 spin_lock_irq(&uport->lock);
961                 result |= uport->ops->get_mctrl(uport);
962                 spin_unlock_irq(&uport->lock);
963         }
964         mutex_unlock(&port->mutex);
966         return result;
969 static int
970 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
972         struct uart_state *state = tty->driver_data;
973         struct uart_port *uport = state->uart_port;
974         struct tty_port *port = &state->port;
975         int ret = -EIO;
977         mutex_lock(&port->mutex);
978         if (!(tty->flags & (1 << TTY_IO_ERROR))) {
979                 uart_update_mctrl(uport, set, clear);
980                 ret = 0;
981         }
982         mutex_unlock(&port->mutex);
983         return ret;
986 static int uart_break_ctl(struct tty_struct *tty, int break_state)
988         struct uart_state *state = tty->driver_data;
989         struct tty_port *port = &state->port;
990         struct uart_port *uport = state->uart_port;
992         mutex_lock(&port->mutex);
994         if (uport->type != PORT_UNKNOWN)
995                 uport->ops->break_ctl(uport, break_state);
997         mutex_unlock(&port->mutex);
998         return 0;
1001 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1003         struct uart_port *uport = state->uart_port;
1004         struct tty_port *port = &state->port;
1005         int flags, ret;
1007         if (!capable(CAP_SYS_ADMIN))
1008                 return -EPERM;
1010         /*
1011          * Take the per-port semaphore.  This prevents count from
1012          * changing, and hence any extra opens of the port while
1013          * we're auto-configuring.
1014          */
1015         if (mutex_lock_interruptible(&port->mutex))
1016                 return -ERESTARTSYS;
1018         ret = -EBUSY;
1019         if (tty_port_users(port) == 1) {
1020                 uart_shutdown(tty, state);
1022                 /*
1023                  * If we already have a port type configured,
1024                  * we must release its resources.
1025                  */
1026                 if (uport->type != PORT_UNKNOWN)
1027                         uport->ops->release_port(uport);
1029                 flags = UART_CONFIG_TYPE;
1030                 if (uport->flags & UPF_AUTO_IRQ)
1031                         flags |= UART_CONFIG_IRQ;
1033                 /*
1034                  * This will claim the ports resources if
1035                  * a port is found.
1036                  */
1037                 uport->ops->config_port(uport, flags);
1039                 ret = uart_startup(tty, state, 1);
1040         }
1041         mutex_unlock(&port->mutex);
1042         return ret;
1045 /*
1046  * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1047  * - mask passed in arg for lines of interest
1048  *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1049  * Caller should use TIOCGICOUNT to see which one it was
1050  *
1051  * FIXME: This wants extracting into a common all driver implementation
1052  * of TIOCMWAIT using tty_port.
1053  */
1054 static int
1055 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1057         struct uart_port *uport = state->uart_port;
1058         struct tty_port *port = &state->port;
1059         DECLARE_WAITQUEUE(wait, current);
1060         struct uart_icount cprev, cnow;
1061         int ret;
1063         /*
1064          * note the counters on entry
1065          */
1066         spin_lock_irq(&uport->lock);
1067         memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1069         /*
1070          * Force modem status interrupts on
1071          */
1072         uport->ops->enable_ms(uport);
1073         spin_unlock_irq(&uport->lock);
1075         add_wait_queue(&port->delta_msr_wait, &wait);
1076         for (;;) {
1077                 spin_lock_irq(&uport->lock);
1078                 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1079                 spin_unlock_irq(&uport->lock);
1081                 set_current_state(TASK_INTERRUPTIBLE);
1083                 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1084                     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1085                     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1086                     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1087                         ret = 0;
1088                         break;
1089                 }
1091                 schedule();
1093                 /* see if a signal did it */
1094                 if (signal_pending(current)) {
1095                         ret = -ERESTARTSYS;
1096                         break;
1097                 }
1099                 cprev = cnow;
1100         }
1102         current->state = TASK_RUNNING;
1103         remove_wait_queue(&port->delta_msr_wait, &wait);
1105         return ret;
1108 /*
1109  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1110  * Return: write counters to the user passed counter struct
1111  * NB: both 1->0 and 0->1 transitions are counted except for
1112  *     RI where only 0->1 is counted.
1113  */
1114 static int uart_get_icount(struct tty_struct *tty,
1115                           struct serial_icounter_struct *icount)
1117         struct uart_state *state = tty->driver_data;
1118         struct uart_icount cnow;
1119         struct uart_port *uport = state->uart_port;
1121         spin_lock_irq(&uport->lock);
1122         memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1123         spin_unlock_irq(&uport->lock);
1125         icount->cts         = cnow.cts;
1126         icount->dsr         = cnow.dsr;
1127         icount->rng         = cnow.rng;
1128         icount->dcd         = cnow.dcd;
1129         icount->rx          = cnow.rx;
1130         icount->tx          = cnow.tx;
1131         icount->frame       = cnow.frame;
1132         icount->overrun     = cnow.overrun;
1133         icount->parity      = cnow.parity;
1134         icount->brk         = cnow.brk;
1135         icount->buf_overrun = cnow.buf_overrun;
1137         return 0;
1140 /*
1141  * Called via sys_ioctl.  We can use spin_lock_irq() here.
1142  */
1143 static int
1144 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1145            unsigned long arg)
1147         struct uart_state *state = tty->driver_data;
1148         struct tty_port *port = &state->port;
1149         void __user *uarg = (void __user *)arg;
1150         int ret = -ENOIOCTLCMD;
1153         /*
1154          * These ioctls don't rely on the hardware to be present.
1155          */
1156         switch (cmd) {
1157         case TIOCGSERIAL:
1158                 ret = uart_get_info_user(port, uarg);
1159                 break;
1161         case TIOCSSERIAL:
1162                 ret = uart_set_info_user(tty, state, uarg);
1163                 break;
1165         case TIOCSERCONFIG:
1166                 ret = uart_do_autoconfig(tty, state);
1167                 break;
1169         case TIOCSERGWILD: /* obsolete */
1170         case TIOCSERSWILD: /* obsolete */
1171                 ret = 0;
1172                 break;
1173         }
1175         if (ret != -ENOIOCTLCMD)
1176                 goto out;
1178         if (tty->flags & (1 << TTY_IO_ERROR)) {
1179                 ret = -EIO;
1180                 goto out;
1181         }
1183         /*
1184          * The following should only be used when hardware is present.
1185          */
1186         switch (cmd) {
1187         case TIOCMIWAIT:
1188                 ret = uart_wait_modem_status(state, arg);
1189                 break;
1190         }
1192         if (ret != -ENOIOCTLCMD)
1193                 goto out;
1195         mutex_lock(&port->mutex);
1197         if (tty->flags & (1 << TTY_IO_ERROR)) {
1198                 ret = -EIO;
1199                 goto out_up;
1200         }
1202         /*
1203          * All these rely on hardware being present and need to be
1204          * protected against the tty being hung up.
1205          */
1206         switch (cmd) {
1207         case TIOCSERGETLSR: /* Get line status register */
1208                 ret = uart_get_lsr_info(tty, state, uarg);
1209                 break;
1211         default: {
1212                 struct uart_port *uport = state->uart_port;
1213                 if (uport->ops->ioctl)
1214                         ret = uport->ops->ioctl(uport, cmd, arg);
1215                 break;
1216         }
1217         }
1218 out_up:
1219         mutex_unlock(&port->mutex);
1220 out:
1221         return ret;
1224 static void uart_set_ldisc(struct tty_struct *tty)
1226         struct uart_state *state = tty->driver_data;
1227         struct uart_port *uport = state->uart_port;
1229         if (uport->ops->set_ldisc)
1230                 uport->ops->set_ldisc(uport, tty->termios.c_line);
1233 static void uart_set_termios(struct tty_struct *tty,
1234                                                 struct ktermios *old_termios)
1236         struct uart_state *state = tty->driver_data;
1237         struct uart_port *uport = state->uart_port;
1238         unsigned long flags;
1239         unsigned int cflag = tty->termios.c_cflag;
1240         unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1241         bool sw_changed = false;
1243         /*
1244          * Drivers doing software flow control also need to know
1245          * about changes to these input settings.
1246          */
1247         if (uport->flags & UPF_SOFT_FLOW) {
1248                 iflag_mask |= IXANY|IXON|IXOFF;
1249                 sw_changed =
1250                    tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1251                    tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1252         }
1254         /*
1255          * These are the bits that are used to setup various
1256          * flags in the low level driver. We can ignore the Bfoo
1257          * bits in c_cflag; c_[io]speed will always be set
1258          * appropriately by set_termios() in tty_ioctl.c
1259          */
1260         if ((cflag ^ old_termios->c_cflag) == 0 &&
1261             tty->termios.c_ospeed == old_termios->c_ospeed &&
1262             tty->termios.c_ispeed == old_termios->c_ispeed &&
1263             ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1264             !sw_changed) {
1265                 return;
1266         }
1268         uart_change_speed(tty, state, old_termios);
1270         /* Handle transition to B0 status */
1271         if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1272                 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1273         /* Handle transition away from B0 status */
1274         else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1275                 unsigned int mask = TIOCM_DTR;
1276                 if (!(cflag & CRTSCTS) ||
1277                     !test_bit(TTY_THROTTLED, &tty->flags))
1278                         mask |= TIOCM_RTS;
1279                 uart_set_mctrl(uport, mask);
1280         }
1282         /*
1283          * If the port is doing h/w assisted flow control, do nothing.
1284          * We assume that tty->hw_stopped has never been set.
1285          */
1286         if (uport->flags & UPF_HARD_FLOW)
1287                 return;
1289         /* Handle turning off CRTSCTS */
1290         if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1291                 spin_lock_irqsave(&uport->lock, flags);
1292                 tty->hw_stopped = 0;
1293                 __uart_start(tty);
1294                 spin_unlock_irqrestore(&uport->lock, flags);
1295         }
1296         /* Handle turning on CRTSCTS */
1297         else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1298                 spin_lock_irqsave(&uport->lock, flags);
1299                 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
1300                         tty->hw_stopped = 1;
1301                         uport->ops->stop_tx(uport);
1302                 }
1303                 spin_unlock_irqrestore(&uport->lock, flags);
1304         }
1307 /*
1308  * In 2.4.5, calls to this will be serialized via the BKL in
1309  *  linux/drivers/char/tty_io.c:tty_release()
1310  *  linux/drivers/char/tty_io.c:do_tty_handup()
1311  */
1312 static void uart_close(struct tty_struct *tty, struct file *filp)
1314         struct uart_state *state = tty->driver_data;
1315         struct tty_port *port;
1316         struct uart_port *uport;
1317         unsigned long flags;
1319         if (!state)
1320                 return;
1322         uport = state->uart_port;
1323         port = &state->port;
1325         pr_debug("uart_close(%d) called\n", uport->line);
1327         if (tty_port_close_start(port, tty, filp) == 0)
1328                 return;
1330         /*
1331          * At this point, we stop accepting input.  To do this, we
1332          * disable the receive line status interrupts.
1333          */
1334         if (port->flags & ASYNC_INITIALIZED) {
1335                 unsigned long flags;
1336                 spin_lock_irqsave(&uport->lock, flags);
1337                 uport->ops->stop_rx(uport);
1338                 spin_unlock_irqrestore(&uport->lock, flags);
1339                 /*
1340                  * Before we drop DTR, make sure the UART transmitter
1341                  * has completely drained; this is especially
1342                  * important if there is a transmit FIFO!
1343                  */
1344                 uart_wait_until_sent(tty, uport->timeout);
1345         }
1347         mutex_lock(&port->mutex);
1348         uart_shutdown(tty, state);
1349         uart_flush_buffer(tty);
1351         tty_ldisc_flush(tty);
1353         tty_port_tty_set(port, NULL);
1354         spin_lock_irqsave(&port->lock, flags);
1355         tty->closing = 0;
1357         if (port->blocked_open) {
1358                 spin_unlock_irqrestore(&port->lock, flags);
1359                 if (port->close_delay)
1360                         msleep_interruptible(
1361                                         jiffies_to_msecs(port->close_delay));
1362                 spin_lock_irqsave(&port->lock, flags);
1363         } else if (!uart_console(uport)) {
1364                 spin_unlock_irqrestore(&port->lock, flags);
1365                 uart_change_pm(state, 3);
1366                 spin_lock_irqsave(&port->lock, flags);
1367         }
1369         /*
1370          * Wake up anyone trying to open this port.
1371          */
1372         clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1373         clear_bit(ASYNCB_CLOSING, &port->flags);
1374         spin_unlock_irqrestore(&port->lock, flags);
1375         wake_up_interruptible(&port->open_wait);
1376         wake_up_interruptible(&port->close_wait);
1378         mutex_unlock(&port->mutex);
1381 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1383         struct uart_state *state = tty->driver_data;
1384         struct uart_port *port = state->uart_port;
1385         unsigned long char_time, expire;
1387         if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1388                 return;
1390         /*
1391          * Set the check interval to be 1/5 of the estimated time to
1392          * send a single character, and make it at least 1.  The check
1393          * interval should also be less than the timeout.
1394          *
1395          * Note: we have to use pretty tight timings here to satisfy
1396          * the NIST-PCTS.
1397          */
1398         char_time = (port->timeout - HZ/50) / port->fifosize;
1399         char_time = char_time / 5;
1400         if (char_time == 0)
1401                 char_time = 1;
1402         if (timeout && timeout < char_time)
1403                 char_time = timeout;
1405         /*
1406          * If the transmitter hasn't cleared in twice the approximate
1407          * amount of time to send the entire FIFO, it probably won't
1408          * ever clear.  This assumes the UART isn't doing flow
1409          * control, which is currently the case.  Hence, if it ever
1410          * takes longer than port->timeout, this is probably due to a
1411          * UART bug of some kind.  So, we clamp the timeout parameter at
1412          * 2*port->timeout.
1413          */
1414         if (timeout == 0 || timeout > 2 * port->timeout)
1415                 timeout = 2 * port->timeout;
1417         expire = jiffies + timeout;
1419         pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1420                 port->line, jiffies, expire);
1422         /*
1423          * Check whether the transmitter is empty every 'char_time'.
1424          * 'timeout' / 'expire' give us the maximum amount of time
1425          * we wait.
1426          */
1427         while (!port->ops->tx_empty(port)) {
1428                 msleep_interruptible(jiffies_to_msecs(char_time));
1429                 if (signal_pending(current))
1430                         break;
1431                 if (time_after(jiffies, expire))
1432                         break;
1433         }
1436 /*
1437  * This is called with the BKL held in
1438  *  linux/drivers/char/tty_io.c:do_tty_hangup()
1439  * We're called from the eventd thread, so we can sleep for
1440  * a _short_ time only.
1441  */
1442 static void uart_hangup(struct tty_struct *tty)
1444         struct uart_state *state = tty->driver_data;
1445         struct tty_port *port = &state->port;
1446         unsigned long flags;
1448         pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1450         mutex_lock(&port->mutex);
1451         if (port->flags & ASYNC_NORMAL_ACTIVE) {
1452                 uart_flush_buffer(tty);
1453                 uart_shutdown(tty, state);
1454                 spin_lock_irqsave(&port->lock, flags);
1455                 port->count = 0;
1456                 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1457                 spin_unlock_irqrestore(&port->lock, flags);
1458                 tty_port_tty_set(port, NULL);
1459                 wake_up_interruptible(&port->open_wait);
1460                 wake_up_interruptible(&port->delta_msr_wait);
1461         }
1462         mutex_unlock(&port->mutex);
1465 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1467         return 0;
1470 static void uart_port_shutdown(struct tty_port *port)
1472         struct uart_state *state = container_of(port, struct uart_state, port);
1473         struct uart_port *uport = state->uart_port;
1475         /*
1476          * clear delta_msr_wait queue to avoid mem leaks: we may free
1477          * the irq here so the queue might never be woken up.  Note
1478          * that we won't end up waiting on delta_msr_wait again since
1479          * any outstanding file descriptors should be pointing at
1480          * hung_up_tty_fops now.
1481          */
1482         wake_up_interruptible(&port->delta_msr_wait);
1484         /*
1485          * Free the IRQ and disable the port.
1486          */
1487         uport->ops->shutdown(uport);
1489         /*
1490          * Ensure that the IRQ handler isn't running on another CPU.
1491          */
1492         synchronize_irq(uport->irq);
1495 static int uart_carrier_raised(struct tty_port *port)
1497         struct uart_state *state = container_of(port, struct uart_state, port);
1498         struct uart_port *uport = state->uart_port;
1499         int mctrl;
1500         spin_lock_irq(&uport->lock);
1501         uport->ops->enable_ms(uport);
1502         mctrl = uport->ops->get_mctrl(uport);
1503         spin_unlock_irq(&uport->lock);
1504         if (mctrl & TIOCM_CAR)
1505                 return 1;
1506         return 0;
1509 static void uart_dtr_rts(struct tty_port *port, int onoff)
1511         struct uart_state *state = container_of(port, struct uart_state, port);
1512         struct uart_port *uport = state->uart_port;
1514         if (onoff)
1515                 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1516         else
1517                 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1520 /*
1521  * calls to uart_open are serialised by the BKL in
1522  *   fs/char_dev.c:chrdev_open()
1523  * Note that if this fails, then uart_close() _will_ be called.
1524  *
1525  * In time, we want to scrap the "opening nonpresent ports"
1526  * behaviour and implement an alternative way for setserial
1527  * to set base addresses/ports/types.  This will allow us to
1528  * get rid of a certain amount of extra tests.
1529  */
1530 static int uart_open(struct tty_struct *tty, struct file *filp)
1532         struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1533         int retval, line = tty->index;
1534         struct uart_state *state = drv->state + line;
1535         struct tty_port *port = &state->port;
1537         pr_debug("uart_open(%d) called\n", line);
1539         /*
1540          * We take the semaphore here to guarantee that we won't be re-entered
1541          * while allocating the state structure, or while we request any IRQs
1542          * that the driver may need.  This also has the nice side-effect that
1543          * it delays the action of uart_hangup, so we can guarantee that
1544          * state->port.tty will always contain something reasonable.
1545          */
1546         if (mutex_lock_interruptible(&port->mutex)) {
1547                 retval = -ERESTARTSYS;
1548                 goto end;
1549         }
1551         port->count++;
1552         if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1553                 retval = -ENXIO;
1554                 goto err_dec_count;
1555         }
1557         /*
1558          * Once we set tty->driver_data here, we are guaranteed that
1559          * uart_close() will decrement the driver module use count.
1560          * Any failures from here onwards should not touch the count.
1561          */
1562         tty->driver_data = state;
1563         state->uart_port->state = state;
1564         tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1565         tty_port_tty_set(port, tty);
1567         /*
1568          * If the port is in the middle of closing, bail out now.
1569          */
1570         if (tty_hung_up_p(filp)) {
1571                 retval = -EAGAIN;
1572                 goto err_dec_count;
1573         }
1575         /*
1576          * Make sure the device is in D0 state.
1577          */
1578         if (port->count == 1)
1579                 uart_change_pm(state, 0);
1581         /*
1582          * Start up the serial port.
1583          */
1584         retval = uart_startup(tty, state, 0);
1586         /*
1587          * If we succeeded, wait until the port is ready.
1588          */
1589         mutex_unlock(&port->mutex);
1590         if (retval == 0)
1591                 retval = tty_port_block_til_ready(port, tty, filp);
1593 end:
1594         return retval;
1595 err_dec_count:
1596         port->count--;
1597         mutex_unlock(&port->mutex);
1598         goto end;
1601 static const char *uart_type(struct uart_port *port)
1603         const char *str = NULL;
1605         if (port->ops->type)
1606                 str = port->ops->type(port);
1608         if (!str)
1609                 str = "unknown";
1611         return str;
1614 #ifdef CONFIG_PROC_FS
1616 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1618         struct uart_state *state = drv->state + i;
1619         struct tty_port *port = &state->port;
1620         int pm_state;
1621         struct uart_port *uport = state->uart_port;
1622         char stat_buf[32];
1623         unsigned int status;
1624         int mmio;
1626         if (!uport)
1627                 return;
1629         mmio = uport->iotype >= UPIO_MEM;
1630         seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1631                         uport->line, uart_type(uport),
1632                         mmio ? "mmio:0x" : "port:",
1633                         mmio ? (unsigned long long)uport->mapbase
1634                              : (unsigned long long)uport->iobase,
1635                         uport->irq);
1637         if (uport->type == PORT_UNKNOWN) {
1638                 seq_putc(m, '\n');
1639                 return;
1640         }
1642         if (capable(CAP_SYS_ADMIN)) {
1643                 mutex_lock(&port->mutex);
1644                 pm_state = state->pm_state;
1645                 if (pm_state)
1646                         uart_change_pm(state, 0);
1647                 spin_lock_irq(&uport->lock);
1648                 status = uport->ops->get_mctrl(uport);
1649                 spin_unlock_irq(&uport->lock);
1650                 if (pm_state)
1651                         uart_change_pm(state, pm_state);
1652                 mutex_unlock(&port->mutex);
1654                 seq_printf(m, " tx:%d rx:%d",
1655                                 uport->icount.tx, uport->icount.rx);
1656                 if (uport->icount.frame)
1657                         seq_printf(m, " fe:%d",
1658                                 uport->icount.frame);
1659                 if (uport->icount.parity)
1660                         seq_printf(m, " pe:%d",
1661                                 uport->icount.parity);
1662                 if (uport->icount.brk)
1663                         seq_printf(m, " brk:%d",
1664                                 uport->icount.brk);
1665                 if (uport->icount.overrun)
1666                         seq_printf(m, " oe:%d",
1667                                 uport->icount.overrun);
1669 #define INFOBIT(bit, str) \
1670         if (uport->mctrl & (bit)) \
1671                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1672                         strlen(stat_buf) - 2)
1673 #define STATBIT(bit, str) \
1674         if (status & (bit)) \
1675                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1676                        strlen(stat_buf) - 2)
1678                 stat_buf[0] = '\0';
1679                 stat_buf[1] = '\0';
1680                 INFOBIT(TIOCM_RTS, "|RTS");
1681                 STATBIT(TIOCM_CTS, "|CTS");
1682                 INFOBIT(TIOCM_DTR, "|DTR");
1683                 STATBIT(TIOCM_DSR, "|DSR");
1684                 STATBIT(TIOCM_CAR, "|CD");
1685                 STATBIT(TIOCM_RNG, "|RI");
1686                 if (stat_buf[0])
1687                         stat_buf[0] = ' ';
1689                 seq_puts(m, stat_buf);
1690         }
1691         seq_putc(m, '\n');
1692 #undef STATBIT
1693 #undef INFOBIT
1696 static int uart_proc_show(struct seq_file *m, void *v)
1698         struct tty_driver *ttydrv = m->private;
1699         struct uart_driver *drv = ttydrv->driver_state;
1700         int i;
1702         seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1703                         "", "", "");
1704         for (i = 0; i < drv->nr; i++)
1705                 uart_line_info(m, drv, i);
1706         return 0;
1709 static int uart_proc_open(struct inode *inode, struct file *file)
1711         return single_open(file, uart_proc_show, PDE(inode)->data);
1714 static const struct file_operations uart_proc_fops = {
1715         .owner          = THIS_MODULE,
1716         .open           = uart_proc_open,
1717         .read           = seq_read,
1718         .llseek         = seq_lseek,
1719         .release        = single_release,
1720 };
1721 #endif
1723 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1724 /*
1725  *      uart_console_write - write a console message to a serial port
1726  *      @port: the port to write the message
1727  *      @s: array of characters
1728  *      @count: number of characters in string to write
1729  *      @write: function to write character to port
1730  */
1731 void uart_console_write(struct uart_port *port, const char *s,
1732                         unsigned int count,
1733                         void (*putchar)(struct uart_port *, int))
1735         unsigned int i;
1737         for (i = 0; i < count; i++, s++) {
1738                 if (*s == '\n')
1739                         putchar(port, '\r');
1740                 putchar(port, *s);
1741         }
1743 EXPORT_SYMBOL_GPL(uart_console_write);
1745 /*
1746  *      Check whether an invalid uart number has been specified, and
1747  *      if so, search for the first available port that does have
1748  *      console support.
1749  */
1750 struct uart_port * __init
1751 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1753         int idx = co->index;
1755         if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1756                                      ports[idx].membase == NULL))
1757                 for (idx = 0; idx < nr; idx++)
1758                         if (ports[idx].iobase != 0 ||
1759                             ports[idx].membase != NULL)
1760                                 break;
1762         co->index = idx;
1764         return ports + idx;
1767 /**
1768  *      uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1769  *      @options: pointer to option string
1770  *      @baud: pointer to an 'int' variable for the baud rate.
1771  *      @parity: pointer to an 'int' variable for the parity.
1772  *      @bits: pointer to an 'int' variable for the number of data bits.
1773  *      @flow: pointer to an 'int' variable for the flow control character.
1774  *
1775  *      uart_parse_options decodes a string containing the serial console
1776  *      options.  The format of the string is <baud><parity><bits><flow>,
1777  *      eg: 115200n8r
1778  */
1779 void
1780 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1782         char *s = options;
1784         *baud = simple_strtoul(s, NULL, 10);
1785         while (*s >= '0' && *s <= '9')
1786                 s++;
1787         if (*s)
1788                 *parity = *s++;
1789         if (*s)
1790                 *bits = *s++ - '0';
1791         if (*s)
1792                 *flow = *s;
1794 EXPORT_SYMBOL_GPL(uart_parse_options);
1796 struct baud_rates {
1797         unsigned int rate;
1798         unsigned int cflag;
1799 };
1801 static const struct baud_rates baud_rates[] = {
1802         { 921600, B921600 },
1803         { 460800, B460800 },
1804         { 230400, B230400 },
1805         { 115200, B115200 },
1806         {  57600, B57600  },
1807         {  38400, B38400  },
1808         {  19200, B19200  },
1809         {   9600, B9600   },
1810         {   4800, B4800   },
1811         {   2400, B2400   },
1812         {   1200, B1200   },
1813         {      0, B38400  }
1814 };
1816 /**
1817  *      uart_set_options - setup the serial console parameters
1818  *      @port: pointer to the serial ports uart_port structure
1819  *      @co: console pointer
1820  *      @baud: baud rate
1821  *      @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1822  *      @bits: number of data bits
1823  *      @flow: flow control character - 'r' (rts)
1824  */
1825 int
1826 uart_set_options(struct uart_port *port, struct console *co,
1827                  int baud, int parity, int bits, int flow)
1829         struct ktermios termios;
1830         static struct ktermios dummy;
1831         int i;
1833         /*
1834          * Ensure that the serial console lock is initialised
1835          * early.
1836          */
1837         spin_lock_init(&port->lock);
1838         lockdep_set_class(&port->lock, &port_lock_key);
1840         memset(&termios, 0, sizeof(struct ktermios));
1842         termios.c_cflag = CREAD | HUPCL | CLOCAL;
1844         /*
1845          * Construct a cflag setting.
1846          */
1847         for (i = 0; baud_rates[i].rate; i++)
1848                 if (baud_rates[i].rate <= baud)
1849                         break;
1851         termios.c_cflag |= baud_rates[i].cflag;
1853         if (bits == 7)
1854                 termios.c_cflag |= CS7;
1855         else
1856                 termios.c_cflag |= CS8;
1858         switch (parity) {
1859         case 'o': case 'O':
1860                 termios.c_cflag |= PARODD;
1861                 /*fall through*/
1862         case 'e': case 'E':
1863                 termios.c_cflag |= PARENB;
1864                 break;
1865         }
1867         if (flow == 'r')
1868                 termios.c_cflag |= CRTSCTS;
1870         /*
1871          * some uarts on other side don't support no flow control.
1872          * So we set * DTR in host uart to make them happy
1873          */
1874         port->mctrl |= TIOCM_DTR;
1876         port->ops->set_termios(port, &termios, &dummy);
1877         /*
1878          * Allow the setting of the UART parameters with a NULL console
1879          * too:
1880          */
1881         if (co)
1882                 co->cflag = termios.c_cflag;
1884         return 0;
1886 EXPORT_SYMBOL_GPL(uart_set_options);
1887 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1889 /**
1890  * uart_change_pm - set power state of the port
1891  *
1892  * @state: port descriptor
1893  * @pm_state: new state
1894  *
1895  * Locking: port->mutex has to be held
1896  */
1897 static void uart_change_pm(struct uart_state *state, int pm_state)
1899         struct uart_port *port = state->uart_port;
1901         if (state->pm_state != pm_state) {
1902                 if (port->ops->pm)
1903                         port->ops->pm(port, pm_state, state->pm_state);
1904                 state->pm_state = pm_state;
1905         }
1908 struct uart_match {
1909         struct uart_port *port;
1910         struct uart_driver *driver;
1911 };
1913 static int serial_match_port(struct device *dev, void *data)
1915         struct uart_match *match = data;
1916         struct tty_driver *tty_drv = match->driver->tty_driver;
1917         dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1918                 match->port->line;
1920         return dev->devt == devt; /* Actually, only one tty per port */
1923 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1925         struct uart_state *state = drv->state + uport->line;
1926         struct tty_port *port = &state->port;
1927         struct device *tty_dev;
1928         struct uart_match match = {uport, drv};
1930         mutex_lock(&port->mutex);
1932         tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1933         if (device_may_wakeup(tty_dev)) {
1934                 if (!enable_irq_wake(uport->irq))
1935                         uport->irq_wake = 1;
1936                 put_device(tty_dev);
1937                 mutex_unlock(&port->mutex);
1938                 return 0;
1939         }
1940         put_device(tty_dev);
1942         if (console_suspend_enabled || !uart_console(uport))
1943                 uport->suspended = 1;
1945         if (port->flags & ASYNC_INITIALIZED) {
1946                 const struct uart_ops *ops = uport->ops;
1947                 int tries;
1949                 if (console_suspend_enabled || !uart_console(uport)) {
1950                         set_bit(ASYNCB_SUSPENDED, &port->flags);
1951                         clear_bit(ASYNCB_INITIALIZED, &port->flags);
1953                         spin_lock_irq(&uport->lock);
1954                         ops->stop_tx(uport);
1955                         ops->set_mctrl(uport, 0);
1956                         ops->stop_rx(uport);
1957                         spin_unlock_irq(&uport->lock);
1958                 }
1960                 /*
1961                  * Wait for the transmitter to empty.
1962                  */
1963                 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1964                         msleep(10);
1965                 if (!tries)
1966                         printk(KERN_ERR "%s%s%s%d: Unable to drain "
1967                                         "transmitter\n",
1968                                uport->dev ? dev_name(uport->dev) : "",
1969                                uport->dev ? ": " : "",
1970                                drv->dev_name,
1971                                drv->tty_driver->name_base + uport->line);
1973                 if (console_suspend_enabled || !uart_console(uport))
1974                         ops->shutdown(uport);
1975         }
1977         /*
1978          * Disable the console device before suspending.
1979          */
1980         if (console_suspend_enabled && uart_console(uport))
1981                 console_stop(uport->cons);
1983         if (console_suspend_enabled || !uart_console(uport))
1984                 uart_change_pm(state, 3);
1986         mutex_unlock(&port->mutex);
1988         return 0;
1991 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1993         struct uart_state *state = drv->state + uport->line;
1994         struct tty_port *port = &state->port;
1995         struct device *tty_dev;
1996         struct uart_match match = {uport, drv};
1997         struct ktermios termios;
1999         mutex_lock(&port->mutex);
2001         tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2002         if (!uport->suspended && device_may_wakeup(tty_dev)) {
2003                 if (uport->irq_wake) {
2004                         disable_irq_wake(uport->irq);
2005                         uport->irq_wake = 0;
2006                 }
2007                 put_device(tty_dev);
2008                 mutex_unlock(&port->mutex);
2009                 return 0;
2010         }
2011         put_device(tty_dev);
2012         uport->suspended = 0;
2014         /*
2015          * Re-enable the console device after suspending.
2016          */
2017         if (uart_console(uport)) {
2018                 /*
2019                  * First try to use the console cflag setting.
2020                  */
2021                 memset(&termios, 0, sizeof(struct ktermios));
2022                 termios.c_cflag = uport->cons->cflag;
2024                 /*
2025                  * If that's unset, use the tty termios setting.
2026                  */
2027                 if (port->tty && termios.c_cflag == 0)
2028                         termios = port->tty->termios;
2030                 if (console_suspend_enabled)
2031                         uart_change_pm(state, 0);
2032                 uport->ops->set_termios(uport, &termios, NULL);
2033                 if (console_suspend_enabled)
2034                         console_start(uport->cons);
2035         }
2037         if (port->flags & ASYNC_SUSPENDED) {
2038                 const struct uart_ops *ops = uport->ops;
2039                 int ret;
2041                 uart_change_pm(state, 0);
2042                 spin_lock_irq(&uport->lock);
2043                 ops->set_mctrl(uport, 0);
2044                 spin_unlock_irq(&uport->lock);
2045                 if (console_suspend_enabled || !uart_console(uport)) {
2046                         /* Protected by port mutex for now */
2047                         struct tty_struct *tty = port->tty;
2048                         ret = ops->startup(uport);
2049                         if (ret == 0) {
2050                                 if (tty)
2051                                         uart_change_speed(tty, state, NULL);
2052                                 spin_lock_irq(&uport->lock);
2053                                 ops->set_mctrl(uport, uport->mctrl);
2054                                 ops->start_tx(uport);
2055                                 spin_unlock_irq(&uport->lock);
2056                                 set_bit(ASYNCB_INITIALIZED, &port->flags);
2057                         } else {
2058                                 /*
2059                                  * Failed to resume - maybe hardware went away?
2060                                  * Clear the "initialized" flag so we won't try
2061                                  * to call the low level drivers shutdown method.
2062                                  */
2063                                 uart_shutdown(tty, state);
2064                         }
2065                 }
2067                 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2068         }
2070         mutex_unlock(&port->mutex);
2072         return 0;
2075 static inline void
2076 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2078         char address[64];
2080         switch (port->iotype) {
2081         case UPIO_PORT:
2082                 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2083                 break;
2084         case UPIO_HUB6:
2085                 snprintf(address, sizeof(address),
2086                          "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2087                 break;
2088         case UPIO_MEM:
2089         case UPIO_MEM32:
2090         case UPIO_AU:
2091         case UPIO_TSI:
2092                 snprintf(address, sizeof(address),
2093                          "MMIO 0x%llx", (unsigned long long)port->mapbase);
2094                 break;
2095         default:
2096                 strlcpy(address, "*unknown*", sizeof(address));
2097                 break;
2098         }
2100         printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2101                port->dev ? dev_name(port->dev) : "",
2102                port->dev ? ": " : "",
2103                drv->dev_name,
2104                drv->tty_driver->name_base + port->line,
2105                address, port->irq, uart_type(port));
2108 static void
2109 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2110                     struct uart_port *port)
2112         unsigned int flags;
2114         /*
2115          * If there isn't a port here, don't do anything further.
2116          */
2117         if (!port->iobase && !port->mapbase && !port->membase)
2118                 return;
2120         /*
2121          * Now do the auto configuration stuff.  Note that config_port
2122          * is expected to claim the resources and map the port for us.
2123          */
2124         flags = 0;
2125         if (port->flags & UPF_AUTO_IRQ)
2126                 flags |= UART_CONFIG_IRQ;
2127         if (port->flags & UPF_BOOT_AUTOCONF) {
2128                 if (!(port->flags & UPF_FIXED_TYPE)) {
2129                         port->type = PORT_UNKNOWN;
2130                         flags |= UART_CONFIG_TYPE;
2131                 }
2132                 port->ops->config_port(port, flags);
2133         }
2135         if (port->type != PORT_UNKNOWN) {
2136                 unsigned long flags;
2138                 uart_report_port(drv, port);
2140                 /* Power up port for set_mctrl() */
2141                 uart_change_pm(state, 0);
2143                 /*
2144                  * Ensure that the modem control lines are de-activated.
2145                  * keep the DTR setting that is set in uart_set_options()
2146                  * We probably don't need a spinlock around this, but
2147                  */
2148                 spin_lock_irqsave(&port->lock, flags);
2149                 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2150                 spin_unlock_irqrestore(&port->lock, flags);
2152                 /*
2153                  * If this driver supports console, and it hasn't been
2154                  * successfully registered yet, try to re-register it.
2155                  * It may be that the port was not available.
2156                  */
2157                 if (port->cons && !(port->cons->flags & CON_ENABLED))
2158                         register_console(port->cons);
2160                 /*
2161                  * Power down all ports by default, except the
2162                  * console if we have one.
2163                  */
2164                 if (!uart_console(port))
2165                         uart_change_pm(state, 3);
2166         }
2169 #ifdef CONFIG_CONSOLE_POLL
2171 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2173         struct uart_driver *drv = driver->driver_state;
2174         struct uart_state *state = drv->state + line;
2175         struct uart_port *port;
2176         int baud = 9600;
2177         int bits = 8;
2178         int parity = 'n';
2179         int flow = 'n';
2180         int ret;
2182         if (!state || !state->uart_port)
2183                 return -1;
2185         port = state->uart_port;
2186         if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2187                 return -1;
2189         if (port->ops->poll_init) {
2190                 struct tty_port *tport = &state->port;
2192                 ret = 0;
2193                 mutex_lock(&tport->mutex);
2194                 /*
2195                  * We don't set ASYNCB_INITIALIZED as we only initialized the
2196                  * hw, e.g. state->xmit is still uninitialized.
2197                  */
2198                 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2199                         ret = port->ops->poll_init(port);
2200                 mutex_unlock(&tport->mutex);
2201                 if (ret)
2202                         return ret;
2203         }
2205         if (options) {
2206                 uart_parse_options(options, &baud, &parity, &bits, &flow);
2207                 return uart_set_options(port, NULL, baud, parity, bits, flow);
2208         }
2210         return 0;
2213 static int uart_poll_get_char(struct tty_driver *driver, int line)
2215         struct uart_driver *drv = driver->driver_state;
2216         struct uart_state *state = drv->state + line;
2217         struct uart_port *port;
2219         if (!state || !state->uart_port)
2220                 return -1;
2222         port = state->uart_port;
2223         return port->ops->poll_get_char(port);
2226 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2228         struct uart_driver *drv = driver->driver_state;
2229         struct uart_state *state = drv->state + line;
2230         struct uart_port *port;
2232         if (!state || !state->uart_port)
2233                 return;
2235         port = state->uart_port;
2236         port->ops->poll_put_char(port, ch);
2238 #endif
2240 static const struct tty_operations uart_ops = {
2241         .open           = uart_open,
2242         .close          = uart_close,
2243         .write          = uart_write,
2244         .put_char       = uart_put_char,
2245         .flush_chars    = uart_flush_chars,
2246         .write_room     = uart_write_room,
2247         .chars_in_buffer= uart_chars_in_buffer,
2248         .flush_buffer   = uart_flush_buffer,
2249         .ioctl          = uart_ioctl,
2250         .throttle       = uart_throttle,
2251         .unthrottle     = uart_unthrottle,
2252         .send_xchar     = uart_send_xchar,
2253         .set_termios    = uart_set_termios,
2254         .set_ldisc      = uart_set_ldisc,
2255         .stop           = uart_stop,
2256         .start          = uart_start,
2257         .hangup         = uart_hangup,
2258         .break_ctl      = uart_break_ctl,
2259         .wait_until_sent= uart_wait_until_sent,
2260 #ifdef CONFIG_PROC_FS
2261         .proc_fops      = &uart_proc_fops,
2262 #endif
2263         .tiocmget       = uart_tiocmget,
2264         .tiocmset       = uart_tiocmset,
2265         .get_icount     = uart_get_icount,
2266 #ifdef CONFIG_CONSOLE_POLL
2267         .poll_init      = uart_poll_init,
2268         .poll_get_char  = uart_poll_get_char,
2269         .poll_put_char  = uart_poll_put_char,
2270 #endif
2271 };
2273 static const struct tty_port_operations uart_port_ops = {
2274         .activate       = uart_port_activate,
2275         .shutdown       = uart_port_shutdown,
2276         .carrier_raised = uart_carrier_raised,
2277         .dtr_rts        = uart_dtr_rts,
2278 };
2280 /**
2281  *      uart_register_driver - register a driver with the uart core layer
2282  *      @drv: low level driver structure
2283  *
2284  *      Register a uart driver with the core driver.  We in turn register
2285  *      with the tty layer, and initialise the core driver per-port state.
2286  *
2287  *      We have a proc file in /proc/tty/driver which is named after the
2288  *      normal driver.
2289  *
2290  *      drv->port should be NULL, and the per-port structures should be
2291  *      registered using uart_add_one_port after this call has succeeded.
2292  */
2293 int uart_register_driver(struct uart_driver *drv)
2295         struct tty_driver *normal;
2296         int i, retval;
2298         BUG_ON(drv->state);
2300         /*
2301          * Maybe we should be using a slab cache for this, especially if
2302          * we have a large number of ports to handle.
2303          */
2304         drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2305         if (!drv->state)
2306                 goto out;
2308         normal = alloc_tty_driver(drv->nr);
2309         if (!normal)
2310                 goto out_kfree;
2312         drv->tty_driver = normal;
2314         normal->driver_name     = drv->driver_name;
2315         normal->name            = drv->dev_name;
2316         normal->major           = drv->major;
2317         normal->minor_start     = drv->minor;
2318         normal->type            = TTY_DRIVER_TYPE_SERIAL;
2319         normal->subtype         = SERIAL_TYPE_NORMAL;
2320         normal->init_termios    = tty_std_termios;
2321         normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2322         normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2323         normal->flags           = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2324         normal->driver_state    = drv;
2325         tty_set_operations(normal, &uart_ops);
2327         /*
2328          * Initialise the UART state(s).
2329          */
2330         for (i = 0; i < drv->nr; i++) {
2331                 struct uart_state *state = drv->state + i;
2332                 struct tty_port *port = &state->port;
2334                 tty_port_init(port);
2335                 port->ops = &uart_port_ops;
2336                 port->close_delay     = HZ / 2; /* .5 seconds */
2337                 port->closing_wait    = 30 * HZ;/* 30 seconds */
2338         }
2340         retval = tty_register_driver(normal);
2341         if (retval >= 0)
2342                 return retval;
2344         for (i = 0; i < drv->nr; i++)
2345                 tty_port_destroy(&drv->state[i].port);
2346         put_tty_driver(normal);
2347 out_kfree:
2348         kfree(drv->state);
2349 out:
2350         return -ENOMEM;
2353 /**
2354  *      uart_unregister_driver - remove a driver from the uart core layer
2355  *      @drv: low level driver structure
2356  *
2357  *      Remove all references to a driver from the core driver.  The low
2358  *      level driver must have removed all its ports via the
2359  *      uart_remove_one_port() if it registered them with uart_add_one_port().
2360  *      (ie, drv->port == NULL)
2361  */
2362 void uart_unregister_driver(struct uart_driver *drv)
2364         struct tty_driver *p = drv->tty_driver;
2365         unsigned int i;
2367         tty_unregister_driver(p);
2368         put_tty_driver(p);
2369         for (i = 0; i < drv->nr; i++)
2370                 tty_port_destroy(&drv->state[i].port);
2371         kfree(drv->state);
2372         drv->state = NULL;
2373         drv->tty_driver = NULL;
2376 struct tty_driver *uart_console_device(struct console *co, int *index)
2378         struct uart_driver *p = co->data;
2379         *index = co->index;
2380         return p->tty_driver;
2383 static ssize_t uart_get_attr_uartclk(struct device *dev,
2384         struct device_attribute *attr, char *buf)
2386         struct serial_struct tmp;
2387         struct tty_port *port = dev_get_drvdata(dev);
2389         uart_get_info(port, &tmp);
2390         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2393 static ssize_t uart_get_attr_type(struct device *dev,
2394         struct device_attribute *attr, char *buf)
2396         struct serial_struct tmp;
2397         struct tty_port *port = dev_get_drvdata(dev);
2399         uart_get_info(port, &tmp);
2400         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2402 static ssize_t uart_get_attr_line(struct device *dev,
2403         struct device_attribute *attr, char *buf)
2405         struct serial_struct tmp;
2406         struct tty_port *port = dev_get_drvdata(dev);
2408         uart_get_info(port, &tmp);
2409         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2412 static ssize_t uart_get_attr_port(struct device *dev,
2413         struct device_attribute *attr, char *buf)
2415         struct serial_struct tmp;
2416         struct tty_port *port = dev_get_drvdata(dev);
2417         unsigned long ioaddr;
2419         uart_get_info(port, &tmp);
2420         ioaddr = tmp.port;
2421         if (HIGH_BITS_OFFSET)
2422                 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2423         return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2426 static ssize_t uart_get_attr_irq(struct device *dev,
2427         struct device_attribute *attr, char *buf)
2429         struct serial_struct tmp;
2430         struct tty_port *port = dev_get_drvdata(dev);
2432         uart_get_info(port, &tmp);
2433         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2436 static ssize_t uart_get_attr_flags(struct device *dev,
2437         struct device_attribute *attr, char *buf)
2439         struct serial_struct tmp;
2440         struct tty_port *port = dev_get_drvdata(dev);
2442         uart_get_info(port, &tmp);
2443         return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2446 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2447         struct device_attribute *attr, char *buf)
2449         struct serial_struct tmp;
2450         struct tty_port *port = dev_get_drvdata(dev);
2452         uart_get_info(port, &tmp);
2453         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2457 static ssize_t uart_get_attr_close_delay(struct device *dev,
2458         struct device_attribute *attr, char *buf)
2460         struct serial_struct tmp;
2461         struct tty_port *port = dev_get_drvdata(dev);
2463         uart_get_info(port, &tmp);
2464         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2468 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2469         struct device_attribute *attr, char *buf)
2471         struct serial_struct tmp;
2472         struct tty_port *port = dev_get_drvdata(dev);
2474         uart_get_info(port, &tmp);
2475         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2478 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2479         struct device_attribute *attr, char *buf)
2481         struct serial_struct tmp;
2482         struct tty_port *port = dev_get_drvdata(dev);
2484         uart_get_info(port, &tmp);
2485         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2488 static ssize_t uart_get_attr_io_type(struct device *dev,
2489         struct device_attribute *attr, char *buf)
2491         struct serial_struct tmp;
2492         struct tty_port *port = dev_get_drvdata(dev);
2494         uart_get_info(port, &tmp);
2495         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2498 static ssize_t uart_get_attr_iomem_base(struct device *dev,
2499         struct device_attribute *attr, char *buf)
2501         struct serial_struct tmp;
2502         struct tty_port *port = dev_get_drvdata(dev);
2504         uart_get_info(port, &tmp);
2505         return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2508 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2509         struct device_attribute *attr, char *buf)
2511         struct serial_struct tmp;
2512         struct tty_port *port = dev_get_drvdata(dev);
2514         uart_get_info(port, &tmp);
2515         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2518 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2519 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2520 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2521 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2522 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2523 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2524 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2525 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2526 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2527 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2528 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2529 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2530 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2532 static struct attribute *tty_dev_attrs[] = {
2533         &dev_attr_type.attr,
2534         &dev_attr_line.attr,
2535         &dev_attr_port.attr,
2536         &dev_attr_irq.attr,
2537         &dev_attr_flags.attr,
2538         &dev_attr_xmit_fifo_size.attr,
2539         &dev_attr_uartclk.attr,
2540         &dev_attr_close_delay.attr,
2541         &dev_attr_closing_wait.attr,
2542         &dev_attr_custom_divisor.attr,
2543         &dev_attr_io_type.attr,
2544         &dev_attr_iomem_base.attr,
2545         &dev_attr_iomem_reg_shift.attr,
2546         NULL,
2547         };
2549 static const struct attribute_group tty_dev_attr_group = {
2550         .attrs = tty_dev_attrs,
2551         };
2553 static const struct attribute_group *tty_dev_attr_groups[] = {
2554         &tty_dev_attr_group,
2555         NULL
2556         };
2559 /**
2560  *      uart_add_one_port - attach a driver-defined port structure
2561  *      @drv: pointer to the uart low level driver structure for this port
2562  *      @uport: uart port structure to use for this port.
2563  *
2564  *      This allows the driver to register its own uart_port structure
2565  *      with the core driver.  The main purpose is to allow the low
2566  *      level uart drivers to expand uart_port, rather than having yet
2567  *      more levels of structures.
2568  */
2569 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2571         struct uart_state *state;
2572         struct tty_port *port;
2573         int ret = 0;
2574         struct device *tty_dev;
2576         BUG_ON(in_interrupt());
2578         if (uport->line >= drv->nr)
2579                 return -EINVAL;
2581         state = drv->state + uport->line;
2582         port = &state->port;
2584         mutex_lock(&port_mutex);
2585         mutex_lock(&port->mutex);
2586         if (state->uart_port) {
2587                 ret = -EINVAL;
2588                 goto out;
2589         }
2591         state->uart_port = uport;
2592         state->pm_state = -1;
2594         uport->cons = drv->cons;
2595         uport->state = state;
2597         /*
2598          * If this port is a console, then the spinlock is already
2599          * initialised.
2600          */
2601         if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2602                 spin_lock_init(&uport->lock);
2603                 lockdep_set_class(&uport->lock, &port_lock_key);
2604         }
2606         uart_configure_port(drv, state, uport);
2608         /*
2609          * Register the port whether it's detected or not.  This allows
2610          * setserial to be used to alter this ports parameters.
2611          */
2612         tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2613                         uport->line, uport->dev, port, tty_dev_attr_groups);
2614         if (likely(!IS_ERR(tty_dev))) {
2615                 device_set_wakeup_capable(tty_dev, 1);
2616         } else {
2617                 printk(KERN_ERR "Cannot register tty device on line %d\n",
2618                        uport->line);
2619         }
2621         /*
2622          * Ensure UPF_DEAD is not set.
2623          */
2624         uport->flags &= ~UPF_DEAD;
2626  out:
2627         mutex_unlock(&port->mutex);
2628         mutex_unlock(&port_mutex);
2630         return ret;
2633 /**
2634  *      uart_remove_one_port - detach a driver defined port structure
2635  *      @drv: pointer to the uart low level driver structure for this port
2636  *      @uport: uart port structure for this port
2637  *
2638  *      This unhooks (and hangs up) the specified port structure from the
2639  *      core driver.  No further calls will be made to the low-level code
2640  *      for this port.
2641  */
2642 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2644         struct uart_state *state = drv->state + uport->line;
2645         struct tty_port *port = &state->port;
2647         BUG_ON(in_interrupt());
2649         if (state->uart_port != uport)
2650                 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2651                         state->uart_port, uport);
2653         mutex_lock(&port_mutex);
2655         /*
2656          * Mark the port "dead" - this prevents any opens from
2657          * succeeding while we shut down the port.
2658          */
2659         mutex_lock(&port->mutex);
2660         uport->flags |= UPF_DEAD;
2661         mutex_unlock(&port->mutex);
2663         /*
2664          * Remove the devices from the tty layer
2665          */
2666         tty_unregister_device(drv->tty_driver, uport->line);
2668         if (port->tty)
2669                 tty_vhangup(port->tty);
2671         /*
2672          * Free the port IO and memory resources, if any.
2673          */
2674         if (uport->type != PORT_UNKNOWN)
2675                 uport->ops->release_port(uport);
2677         /*
2678          * Indicate that there isn't a port here anymore.
2679          */
2680         uport->type = PORT_UNKNOWN;
2682         state->uart_port = NULL;
2683         mutex_unlock(&port_mutex);
2685         return 0;
2688 /*
2689  *      Are the two ports equivalent?
2690  */
2691 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2693         if (port1->iotype != port2->iotype)
2694                 return 0;
2696         switch (port1->iotype) {
2697         case UPIO_PORT:
2698                 return (port1->iobase == port2->iobase);
2699         case UPIO_HUB6:
2700                 return (port1->iobase == port2->iobase) &&
2701                        (port1->hub6   == port2->hub6);
2702         case UPIO_MEM:
2703         case UPIO_MEM32:
2704         case UPIO_AU:
2705         case UPIO_TSI:
2706                 return (port1->mapbase == port2->mapbase);
2707         }
2708         return 0;
2710 EXPORT_SYMBOL(uart_match_port);
2712 /**
2713  *      uart_handle_dcd_change - handle a change of carrier detect state
2714  *      @uport: uart_port structure for the open port
2715  *      @status: new carrier detect status, nonzero if active
2716  */
2717 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2719         struct uart_state *state = uport->state;
2720         struct tty_port *port = &state->port;
2721         struct tty_ldisc *ld = NULL;
2722         struct pps_event_time ts;
2723         struct tty_struct *tty = port->tty;
2725         if (tty)
2726                 ld = tty_ldisc_ref(tty);
2727         if (ld && ld->ops->dcd_change)
2728                 pps_get_ts(&ts);
2730         uport->icount.dcd++;
2731 #ifdef CONFIG_HARD_PPS
2732         if ((uport->flags & UPF_HARDPPS_CD) && status)
2733                 hardpps();
2734 #endif
2736         if (port->flags & ASYNC_CHECK_CD) {
2737                 if (status)
2738                         wake_up_interruptible(&port->open_wait);
2739                 else if (tty)
2740                         tty_hangup(tty);
2741         }
2743         if (ld && ld->ops->dcd_change)
2744                 ld->ops->dcd_change(tty, status, &ts);
2745         if (ld)
2746                 tty_ldisc_deref(ld);
2748 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2750 /**
2751  *      uart_handle_cts_change - handle a change of clear-to-send state
2752  *      @uport: uart_port structure for the open port
2753  *      @status: new clear to send status, nonzero if active
2754  */
2755 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2757         struct tty_port *port = &uport->state->port;
2758         struct tty_struct *tty = port->tty;
2760         uport->icount.cts++;
2762         if (tty_port_cts_enabled(port)) {
2763                 if (tty->hw_stopped) {
2764                         if (status) {
2765                                 tty->hw_stopped = 0;
2766                                 uport->ops->start_tx(uport);
2767                                 uart_write_wakeup(uport);
2768                         }
2769                 } else {
2770                         if (!status) {
2771                                 tty->hw_stopped = 1;
2772                                 uport->ops->stop_tx(uport);
2773                         }
2774                 }
2775         }
2777 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2779 /**
2780  * uart_insert_char - push a char to the uart layer
2781  *
2782  * User is responsible to call tty_flip_buffer_push when they are done with
2783  * insertion.
2784  *
2785  * @port: corresponding port
2786  * @status: state of the serial port RX buffer (LSR for 8250)
2787  * @overrun: mask of overrun bits in @status
2788  * @ch: character to push
2789  * @flag: flag for the character (see TTY_NORMAL and friends)
2790  */
2791 void uart_insert_char(struct uart_port *port, unsigned int status,
2792                  unsigned int overrun, unsigned int ch, unsigned int flag)
2794         struct tty_struct *tty = port->state->port.tty;
2796         if ((status & port->ignore_status_mask & ~overrun) == 0)
2797                 if (tty_insert_flip_char(tty, ch, flag) == 0)
2798                         ++port->icount.buf_overrun;
2800         /*
2801          * Overrun is special.  Since it's reported immediately,
2802          * it doesn't affect the current character.
2803          */
2804         if (status & ~port->ignore_status_mask & overrun)
2805                 if (tty_insert_flip_char(tty, 0, TTY_OVERRUN) == 0)
2806                         ++port->icount.buf_overrun;
2808 EXPORT_SYMBOL_GPL(uart_insert_char);
2810 EXPORT_SYMBOL(uart_write_wakeup);
2811 EXPORT_SYMBOL(uart_register_driver);
2812 EXPORT_SYMBOL(uart_unregister_driver);
2813 EXPORT_SYMBOL(uart_suspend_port);
2814 EXPORT_SYMBOL(uart_resume_port);
2815 EXPORT_SYMBOL(uart_add_one_port);
2816 EXPORT_SYMBOL(uart_remove_one_port);
2818 MODULE_DESCRIPTION("Serial driver core");
2819 MODULE_LICENSE("GPL");