2b0e0f90eff033bcc5cea4f799690c72b34650fd
[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 (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
92             !tty->stopped && !tty->hw_stopped)
93                 port->ops->start_tx(port);
94 }
96 static void uart_start(struct tty_struct *tty)
97 {
98         struct uart_state *state = tty->driver_data;
99         struct uart_port *port = state->uart_port;
100         unsigned long flags;
102         spin_lock_irqsave(&port->lock, flags);
103         __uart_start(tty);
104         spin_unlock_irqrestore(&port->lock, flags);
107 static inline void
108 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
110         unsigned long flags;
111         unsigned int old;
113         spin_lock_irqsave(&port->lock, flags);
114         old = port->mctrl;
115         port->mctrl = (old & ~clear) | set;
116         if (old != port->mctrl)
117                 port->ops->set_mctrl(port, port->mctrl);
118         spin_unlock_irqrestore(&port->lock, flags);
121 #define uart_set_mctrl(port, set)       uart_update_mctrl(port, set, 0)
122 #define uart_clear_mctrl(port, clear)   uart_update_mctrl(port, 0, clear)
124 /*
125  * Startup the port.  This will be called once per open.  All calls
126  * will be serialised by the per-port mutex.
127  */
128 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
129                 int init_hw)
131         struct uart_port *uport = state->uart_port;
132         struct tty_port *port = &state->port;
133         unsigned long page;
134         int retval = 0;
136         if (uport->type == PORT_UNKNOWN)
137                 return 1;
139         /*
140          * Initialise and allocate the transmit and temporary
141          * buffer.
142          */
143         if (!state->xmit.buf) {
144                 /* This is protected by the per port mutex */
145                 page = get_zeroed_page(GFP_KERNEL);
146                 if (!page)
147                         return -ENOMEM;
149                 state->xmit.buf = (unsigned char *) page;
150                 uart_circ_clear(&state->xmit);
151         }
153         retval = uport->ops->startup(uport);
154         if (retval == 0) {
155                 if (uart_console(uport) && uport->cons->cflag) {
156                         tty->termios.c_cflag = uport->cons->cflag;
157                         uport->cons->cflag = 0;
158                 }
159                 /*
160                  * Initialise the hardware port settings.
161                  */
162                 uart_change_speed(tty, state, NULL);
164                 if (init_hw) {
165                         /*
166                          * Setup the RTS and DTR signals once the
167                          * port is open and ready to respond.
168                          */
169                         if (tty->termios.c_cflag & CBAUD)
170                                 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
171                 }
173                 if (tty_port_cts_enabled(port)) {
174                         spin_lock_irq(&uport->lock);
175                         if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
176                                 tty->hw_stopped = 1;
177                         spin_unlock_irq(&uport->lock);
178                 }
179         }
181         /*
182          * This is to allow setserial on this port. People may want to set
183          * port/irq/type and then reconfigure the port properly if it failed
184          * now.
185          */
186         if (retval && capable(CAP_SYS_ADMIN))
187                 return 1;
189         return retval;
192 static int uart_startup(struct tty_struct *tty, struct uart_state *state,
193                 int init_hw)
195         struct tty_port *port = &state->port;
196         int retval;
198         if (port->flags & ASYNC_INITIALIZED)
199                 return 0;
201         /*
202          * Set the TTY IO error marker - we will only clear this
203          * once we have successfully opened the port.
204          */
205         set_bit(TTY_IO_ERROR, &tty->flags);
207         retval = uart_port_startup(tty, state, init_hw);
208         if (!retval) {
209                 set_bit(ASYNCB_INITIALIZED, &port->flags);
210                 clear_bit(TTY_IO_ERROR, &tty->flags);
211         } else if (retval > 0)
212                 retval = 0;
214         return retval;
217 /*
218  * This routine will shutdown a serial port; interrupts are disabled, and
219  * DTR is dropped if the hangup on close termio flag is on.  Calls to
220  * uart_shutdown are serialised by the per-port semaphore.
221  */
222 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
224         struct uart_port *uport = state->uart_port;
225         struct tty_port *port = &state->port;
227         /*
228          * Set the TTY IO error marker
229          */
230         if (tty)
231                 set_bit(TTY_IO_ERROR, &tty->flags);
233         if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
234                 /*
235                  * Turn off DTR and RTS early.
236                  */
237                 if (!tty || (tty->termios.c_cflag & HUPCL))
238                         uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
240                 uart_port_shutdown(port);
241         }
243         /*
244          * It's possible for shutdown to be called after suspend if we get
245          * a DCD drop (hangup) at just the right time.  Clear suspended bit so
246          * we don't try to resume a port that has been shutdown.
247          */
248         clear_bit(ASYNCB_SUSPENDED, &port->flags);
250         /*
251          * Free the transmit buffer page.
252          */
253         if (state->xmit.buf) {
254                 free_page((unsigned long)state->xmit.buf);
255                 state->xmit.buf = NULL;
256         }
259 /**
260  *      uart_update_timeout - update per-port FIFO timeout.
261  *      @port:  uart_port structure describing the port
262  *      @cflag: termios cflag value
263  *      @baud:  speed of the port
264  *
265  *      Set the port FIFO timeout value.  The @cflag value should
266  *      reflect the actual hardware settings.
267  */
268 void
269 uart_update_timeout(struct uart_port *port, unsigned int cflag,
270                     unsigned int baud)
272         unsigned int bits;
274         /* byte size and parity */
275         switch (cflag & CSIZE) {
276         case CS5:
277                 bits = 7;
278                 break;
279         case CS6:
280                 bits = 8;
281                 break;
282         case CS7:
283                 bits = 9;
284                 break;
285         default:
286                 bits = 10;
287                 break; /* CS8 */
288         }
290         if (cflag & CSTOPB)
291                 bits++;
292         if (cflag & PARENB)
293                 bits++;
295         /*
296          * The total number of bits to be transmitted in the fifo.
297          */
298         bits = bits * port->fifosize;
300         /*
301          * Figure the timeout to send the above number of bits.
302          * Add .02 seconds of slop
303          */
304         port->timeout = (HZ * bits) / baud + HZ/50;
307 EXPORT_SYMBOL(uart_update_timeout);
309 /**
310  *      uart_get_baud_rate - return baud rate for a particular port
311  *      @port: uart_port structure describing the port in question.
312  *      @termios: desired termios settings.
313  *      @old: old termios (or NULL)
314  *      @min: minimum acceptable baud rate
315  *      @max: maximum acceptable baud rate
316  *
317  *      Decode the termios structure into a numeric baud rate,
318  *      taking account of the magic 38400 baud rate (with spd_*
319  *      flags), and mapping the %B0 rate to 9600 baud.
320  *
321  *      If the new baud rate is invalid, try the old termios setting.
322  *      If it's still invalid, we try 9600 baud.
323  *
324  *      Update the @termios structure to reflect the baud rate
325  *      we're actually going to be using. Don't do this for the case
326  *      where B0 is requested ("hang up").
327  */
328 unsigned int
329 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
330                    struct ktermios *old, unsigned int min, unsigned int max)
332         unsigned int try, baud, altbaud = 38400;
333         int hung_up = 0;
334         upf_t flags = port->flags & UPF_SPD_MASK;
336         if (flags == UPF_SPD_HI)
337                 altbaud = 57600;
338         else if (flags == UPF_SPD_VHI)
339                 altbaud = 115200;
340         else if (flags == UPF_SPD_SHI)
341                 altbaud = 230400;
342         else if (flags == UPF_SPD_WARP)
343                 altbaud = 460800;
345         for (try = 0; try < 2; try++) {
346                 baud = tty_termios_baud_rate(termios);
348                 /*
349                  * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
350                  * Die! Die! Die!
351                  */
352                 if (baud == 38400)
353                         baud = altbaud;
355                 /*
356                  * Special case: B0 rate.
357                  */
358                 if (baud == 0) {
359                         hung_up = 1;
360                         baud = 9600;
361                 }
363                 if (baud >= min && baud <= max)
364                         return baud;
366                 /*
367                  * Oops, the quotient was zero.  Try again with
368                  * the old baud rate if possible.
369                  */
370                 termios->c_cflag &= ~CBAUD;
371                 if (old) {
372                         baud = tty_termios_baud_rate(old);
373                         if (!hung_up)
374                                 tty_termios_encode_baud_rate(termios,
375                                                                 baud, baud);
376                         old = NULL;
377                         continue;
378                 }
380                 /*
381                  * As a last resort, if the range cannot be met then clip to
382                  * the nearest chip supported rate.
383                  */
384                 if (!hung_up) {
385                         if (baud <= min)
386                                 tty_termios_encode_baud_rate(termios,
387                                                         min + 1, min + 1);
388                         else
389                                 tty_termios_encode_baud_rate(termios,
390                                                         max - 1, max - 1);
391                 }
392         }
393         /* Should never happen */
394         WARN_ON(1);
395         return 0;
398 EXPORT_SYMBOL(uart_get_baud_rate);
400 /**
401  *      uart_get_divisor - return uart clock divisor
402  *      @port: uart_port structure describing the port.
403  *      @baud: desired baud rate
404  *
405  *      Calculate the uart clock divisor for the port.
406  */
407 unsigned int
408 uart_get_divisor(struct uart_port *port, unsigned int baud)
410         unsigned int quot;
412         /*
413          * Old custom speed handling.
414          */
415         if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
416                 quot = port->custom_divisor;
417         else
418                 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
420         return quot;
423 EXPORT_SYMBOL(uart_get_divisor);
425 /* FIXME: Consistent locking policy */
426 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
427                                         struct ktermios *old_termios)
429         struct tty_port *port = &state->port;
430         struct uart_port *uport = state->uart_port;
431         struct ktermios *termios;
433         /*
434          * If we have no tty, termios, or the port does not exist,
435          * then we can't set the parameters for this port.
436          */
437         if (!tty || uport->type == PORT_UNKNOWN)
438                 return;
440         termios = &tty->termios;
442         /*
443          * Set flags based on termios cflag
444          */
445         if (termios->c_cflag & CRTSCTS)
446                 set_bit(ASYNCB_CTS_FLOW, &port->flags);
447         else
448                 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
450         if (termios->c_cflag & CLOCAL)
451                 clear_bit(ASYNCB_CHECK_CD, &port->flags);
452         else
453                 set_bit(ASYNCB_CHECK_CD, &port->flags);
455         uport->ops->set_termios(uport, termios, old_termios);
458 static inline int __uart_put_char(struct uart_port *port,
459                                 struct circ_buf *circ, unsigned char c)
461         unsigned long flags;
462         int ret = 0;
464         if (!circ->buf)
465                 return 0;
467         spin_lock_irqsave(&port->lock, flags);
468         if (uart_circ_chars_free(circ) != 0) {
469                 circ->buf[circ->head] = c;
470                 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
471                 ret = 1;
472         }
473         spin_unlock_irqrestore(&port->lock, flags);
474         return ret;
477 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
479         struct uart_state *state = tty->driver_data;
481         return __uart_put_char(state->uart_port, &state->xmit, ch);
484 static void uart_flush_chars(struct tty_struct *tty)
486         uart_start(tty);
489 static int uart_write(struct tty_struct *tty,
490                                         const unsigned char *buf, int count)
492         struct uart_state *state = tty->driver_data;
493         struct uart_port *port;
494         struct circ_buf *circ;
495         unsigned long flags;
496         int c, ret = 0;
498         /*
499          * This means you called this function _after_ the port was
500          * closed.  No cookie for you.
501          */
502         if (!state) {
503                 WARN_ON(1);
504                 return -EL3HLT;
505         }
507         port = state->uart_port;
508         circ = &state->xmit;
510         if (!circ->buf)
511                 return 0;
513         spin_lock_irqsave(&port->lock, flags);
514         while (1) {
515                 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
516                 if (count < c)
517                         c = count;
518                 if (c <= 0)
519                         break;
520                 memcpy(circ->buf + circ->head, buf, c);
521                 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
522                 buf += c;
523                 count -= c;
524                 ret += c;
525         }
526         spin_unlock_irqrestore(&port->lock, flags);
528         uart_start(tty);
529         return ret;
532 static int uart_write_room(struct tty_struct *tty)
534         struct uart_state *state = tty->driver_data;
535         unsigned long flags;
536         int ret;
538         spin_lock_irqsave(&state->uart_port->lock, flags);
539         ret = uart_circ_chars_free(&state->xmit);
540         spin_unlock_irqrestore(&state->uart_port->lock, flags);
541         return ret;
544 static int uart_chars_in_buffer(struct tty_struct *tty)
546         struct uart_state *state = tty->driver_data;
547         unsigned long flags;
548         int ret;
550         spin_lock_irqsave(&state->uart_port->lock, flags);
551         ret = uart_circ_chars_pending(&state->xmit);
552         spin_unlock_irqrestore(&state->uart_port->lock, flags);
553         return ret;
556 static void uart_flush_buffer(struct tty_struct *tty)
558         struct uart_state *state = tty->driver_data;
559         struct uart_port *port;
560         unsigned long flags;
562         /*
563          * This means you called this function _after_ the port was
564          * closed.  No cookie for you.
565          */
566         if (!state) {
567                 WARN_ON(1);
568                 return;
569         }
571         port = state->uart_port;
572         pr_debug("uart_flush_buffer(%d) called\n", tty->index);
574         spin_lock_irqsave(&port->lock, flags);
575         uart_circ_clear(&state->xmit);
576         if (port->ops->flush_buffer)
577                 port->ops->flush_buffer(port);
578         spin_unlock_irqrestore(&port->lock, flags);
579         tty_wakeup(tty);
582 /*
583  * This function is used to send a high-priority XON/XOFF character to
584  * the device
585  */
586 static void uart_send_xchar(struct tty_struct *tty, char ch)
588         struct uart_state *state = tty->driver_data;
589         struct uart_port *port = state->uart_port;
590         unsigned long flags;
592         if (port->ops->send_xchar)
593                 port->ops->send_xchar(port, ch);
594         else {
595                 port->x_char = ch;
596                 if (ch) {
597                         spin_lock_irqsave(&port->lock, flags);
598                         port->ops->start_tx(port);
599                         spin_unlock_irqrestore(&port->lock, flags);
600                 }
601         }
604 static void uart_throttle(struct tty_struct *tty)
606         struct uart_state *state = tty->driver_data;
607         struct uart_port *port = state->uart_port;
608         uint32_t mask = 0;
610         if (I_IXOFF(tty))
611                 mask |= UPF_SOFT_FLOW;
612         if (tty->termios.c_cflag & CRTSCTS)
613                 mask |= UPF_HARD_FLOW;
615         if (port->flags & mask) {
616                 port->ops->throttle(port);
617                 mask &= ~port->flags;
618         }
620         if (mask & UPF_SOFT_FLOW)
621                 uart_send_xchar(tty, STOP_CHAR(tty));
623         if (mask & UPF_HARD_FLOW)
624                 uart_clear_mctrl(port, TIOCM_RTS);
627 static void uart_unthrottle(struct tty_struct *tty)
629         struct uart_state *state = tty->driver_data;
630         struct uart_port *port = state->uart_port;
631         uint32_t mask = 0;
633         if (I_IXOFF(tty))
634                 mask |= UPF_SOFT_FLOW;
635         if (tty->termios.c_cflag & CRTSCTS)
636                 mask |= UPF_HARD_FLOW;
638         if (port->flags & mask) {
639                 port->ops->unthrottle(port);
640                 mask &= ~port->flags;
641         }
643         if (mask & UPF_SOFT_FLOW) {
644                 if (port->x_char)
645                         port->x_char = 0;
646                 else
647                         uart_send_xchar(tty, START_CHAR(tty));
648         }
650         if (mask & UPF_HARD_FLOW)
651                 uart_set_mctrl(port, TIOCM_RTS);
654 static void do_uart_get_info(struct tty_port *port,
655                         struct serial_struct *retinfo)
657         struct uart_state *state = container_of(port, struct uart_state, port);
658         struct uart_port *uport = state->uart_port;
660         memset(retinfo, 0, sizeof(*retinfo));
662         retinfo->type       = uport->type;
663         retinfo->line       = uport->line;
664         retinfo->port       = uport->iobase;
665         if (HIGH_BITS_OFFSET)
666                 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
667         retinfo->irq                = uport->irq;
668         retinfo->flags      = uport->flags;
669         retinfo->xmit_fifo_size  = uport->fifosize;
670         retinfo->baud_base          = uport->uartclk / 16;
671         retinfo->close_delay        = jiffies_to_msecs(port->close_delay) / 10;
672         retinfo->closing_wait    = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
673                                 ASYNC_CLOSING_WAIT_NONE :
674                                 jiffies_to_msecs(port->closing_wait) / 10;
675         retinfo->custom_divisor  = uport->custom_divisor;
676         retinfo->hub6       = uport->hub6;
677         retinfo->io_type         = uport->iotype;
678         retinfo->iomem_reg_shift = uport->regshift;
679         retinfo->iomem_base      = (void *)(unsigned long)uport->mapbase;
682 static void uart_get_info(struct tty_port *port,
683                         struct serial_struct *retinfo)
685         /* Ensure the state we copy is consistent and no hardware changes
686            occur as we go */
687         mutex_lock(&port->mutex);
688         do_uart_get_info(port, retinfo);
689         mutex_unlock(&port->mutex);
692 static int uart_get_info_user(struct tty_port *port,
693                          struct serial_struct __user *retinfo)
695         struct serial_struct tmp;
696         uart_get_info(port, &tmp);
698         if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
699                 return -EFAULT;
700         return 0;
703 static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
704                          struct uart_state *state,
705                          struct serial_struct *new_info)
707         struct uart_port *uport = state->uart_port;
708         unsigned long new_port;
709         unsigned int change_irq, change_port, closing_wait;
710         unsigned int old_custom_divisor, close_delay;
711         upf_t old_flags, new_flags;
712         int retval = 0;
714         new_port = new_info->port;
715         if (HIGH_BITS_OFFSET)
716                 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
718         new_info->irq = irq_canonicalize(new_info->irq);
719         close_delay = msecs_to_jiffies(new_info->close_delay * 10);
720         closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
721                         ASYNC_CLOSING_WAIT_NONE :
722                         msecs_to_jiffies(new_info->closing_wait * 10);
725         change_irq  = !(uport->flags & UPF_FIXED_PORT)
726                 && new_info->irq != uport->irq;
728         /*
729          * Since changing the 'type' of the port changes its resource
730          * allocations, we should treat type changes the same as
731          * IO port changes.
732          */
733         change_port = !(uport->flags & UPF_FIXED_PORT)
734                 && (new_port != uport->iobase ||
735                     (unsigned long)new_info->iomem_base != uport->mapbase ||
736                     new_info->hub6 != uport->hub6 ||
737                     new_info->io_type != uport->iotype ||
738                     new_info->iomem_reg_shift != uport->regshift ||
739                     new_info->type != uport->type);
741         old_flags = uport->flags;
742         new_flags = new_info->flags;
743         old_custom_divisor = uport->custom_divisor;
745         if (!capable(CAP_SYS_ADMIN)) {
746                 retval = -EPERM;
747                 if (change_irq || change_port ||
748                     (new_info->baud_base != uport->uartclk / 16) ||
749                     (close_delay != port->close_delay) ||
750                     (closing_wait != port->closing_wait) ||
751                     (new_info->xmit_fifo_size &&
752                      new_info->xmit_fifo_size != uport->fifosize) ||
753                     (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
754                         goto exit;
755                 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
756                                (new_flags & UPF_USR_MASK));
757                 uport->custom_divisor = new_info->custom_divisor;
758                 goto check_and_exit;
759         }
761         /*
762          * Ask the low level driver to verify the settings.
763          */
764         if (uport->ops->verify_port)
765                 retval = uport->ops->verify_port(uport, new_info);
767         if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
768             (new_info->baud_base < 9600))
769                 retval = -EINVAL;
771         if (retval)
772                 goto exit;
774         if (change_port || change_irq) {
775                 retval = -EBUSY;
777                 /*
778                  * Make sure that we are the sole user of this port.
779                  */
780                 if (tty_port_users(port) > 1)
781                         goto exit;
783                 /*
784                  * We need to shutdown the serial port at the old
785                  * port/type/irq combination.
786                  */
787                 uart_shutdown(tty, state);
788         }
790         if (change_port) {
791                 unsigned long old_iobase, old_mapbase;
792                 unsigned int old_type, old_iotype, old_hub6, old_shift;
794                 old_iobase = uport->iobase;
795                 old_mapbase = uport->mapbase;
796                 old_type = uport->type;
797                 old_hub6 = uport->hub6;
798                 old_iotype = uport->iotype;
799                 old_shift = uport->regshift;
801                 /*
802                  * Free and release old regions
803                  */
804                 if (old_type != PORT_UNKNOWN)
805                         uport->ops->release_port(uport);
807                 uport->iobase = new_port;
808                 uport->type = new_info->type;
809                 uport->hub6 = new_info->hub6;
810                 uport->iotype = new_info->io_type;
811                 uport->regshift = new_info->iomem_reg_shift;
812                 uport->mapbase = (unsigned long)new_info->iomem_base;
814                 /*
815                  * Claim and map the new regions
816                  */
817                 if (uport->type != PORT_UNKNOWN) {
818                         retval = uport->ops->request_port(uport);
819                 } else {
820                         /* Always success - Jean II */
821                         retval = 0;
822                 }
824                 /*
825                  * If we fail to request resources for the
826                  * new port, try to restore the old settings.
827                  */
828                 if (retval && old_type != PORT_UNKNOWN) {
829                         uport->iobase = old_iobase;
830                         uport->type = old_type;
831                         uport->hub6 = old_hub6;
832                         uport->iotype = old_iotype;
833                         uport->regshift = old_shift;
834                         uport->mapbase = old_mapbase;
835                         retval = uport->ops->request_port(uport);
836                         /*
837                          * If we failed to restore the old settings,
838                          * we fail like this.
839                          */
840                         if (retval)
841                                 uport->type = PORT_UNKNOWN;
843                         /*
844                          * We failed anyway.
845                          */
846                         retval = -EBUSY;
847                         /* Added to return the correct error -Ram Gupta */
848                         goto exit;
849                 }
850         }
852         if (change_irq)
853                 uport->irq      = new_info->irq;
854         if (!(uport->flags & UPF_FIXED_PORT))
855                 uport->uartclk  = new_info->baud_base * 16;
856         uport->flags            = (uport->flags & ~UPF_CHANGE_MASK) |
857                                  (new_flags & UPF_CHANGE_MASK);
858         uport->custom_divisor   = new_info->custom_divisor;
859         port->close_delay     = close_delay;
860         port->closing_wait    = closing_wait;
861         if (new_info->xmit_fifo_size)
862                 uport->fifosize = new_info->xmit_fifo_size;
863         if (port->tty)
864                 port->tty->low_latency =
865                         (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
867  check_and_exit:
868         retval = 0;
869         if (uport->type == PORT_UNKNOWN)
870                 goto exit;
871         if (port->flags & ASYNC_INITIALIZED) {
872                 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
873                     old_custom_divisor != uport->custom_divisor) {
874                         /*
875                          * If they're setting up a custom divisor or speed,
876                          * instead of clearing it, then bitch about it. No
877                          * need to rate-limit; it's CAP_SYS_ADMIN only.
878                          */
879                         if (uport->flags & UPF_SPD_MASK) {
880                                 char buf[64];
881                                 printk(KERN_NOTICE
882                                        "%s sets custom speed on %s. This "
883                                        "is deprecated.\n", current->comm,
884                                        tty_name(port->tty, buf));
885                         }
886                         uart_change_speed(tty, state, NULL);
887                 }
888         } else
889                 retval = uart_startup(tty, state, 1);
890  exit:
891         return retval;
894 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
895                          struct serial_struct __user *newinfo)
897         struct serial_struct new_serial;
898         struct tty_port *port = &state->port;
899         int retval;
901         if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
902                 return -EFAULT;
904         /*
905          * This semaphore protects port->count.  It is also
906          * very useful to prevent opens.  Also, take the
907          * port configuration semaphore to make sure that a
908          * module insertion/removal doesn't change anything
909          * under us.
910          */
911         mutex_lock(&port->mutex);
912         retval = uart_set_info(tty, port, state, &new_serial);
913         mutex_unlock(&port->mutex);
914         return retval;
917 /**
918  *      uart_get_lsr_info       -       get line status register info
919  *      @tty: tty associated with the UART
920  *      @state: UART being queried
921  *      @value: returned modem value
922  *
923  *      Note: uart_ioctl protects us against hangups.
924  */
925 static int uart_get_lsr_info(struct tty_struct *tty,
926                         struct uart_state *state, unsigned int __user *value)
928         struct uart_port *uport = state->uart_port;
929         unsigned int result;
931         result = uport->ops->tx_empty(uport);
933         /*
934          * If we're about to load something into the transmit
935          * register, we'll pretend the transmitter isn't empty to
936          * avoid a race condition (depending on when the transmit
937          * interrupt happens).
938          */
939         if (uport->x_char ||
940             ((uart_circ_chars_pending(&state->xmit) > 0) &&
941              !tty->stopped && !tty->hw_stopped))
942                 result &= ~TIOCSER_TEMT;
944         return put_user(result, value);
947 static int uart_tiocmget(struct tty_struct *tty)
949         struct uart_state *state = tty->driver_data;
950         struct tty_port *port = &state->port;
951         struct uart_port *uport = state->uart_port;
952         int result = -EIO;
954         mutex_lock(&port->mutex);
955         if (!(tty->flags & (1 << TTY_IO_ERROR))) {
956                 result = uport->mctrl;
957                 spin_lock_irq(&uport->lock);
958                 result |= uport->ops->get_mctrl(uport);
959                 spin_unlock_irq(&uport->lock);
960         }
961         mutex_unlock(&port->mutex);
963         return result;
966 static int
967 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
969         struct uart_state *state = tty->driver_data;
970         struct uart_port *uport = state->uart_port;
971         struct tty_port *port = &state->port;
972         int ret = -EIO;
974         mutex_lock(&port->mutex);
975         if (!(tty->flags & (1 << TTY_IO_ERROR))) {
976                 uart_update_mctrl(uport, set, clear);
977                 ret = 0;
978         }
979         mutex_unlock(&port->mutex);
980         return ret;
983 static int uart_break_ctl(struct tty_struct *tty, int break_state)
985         struct uart_state *state = tty->driver_data;
986         struct tty_port *port = &state->port;
987         struct uart_port *uport = state->uart_port;
989         mutex_lock(&port->mutex);
991         if (uport->type != PORT_UNKNOWN)
992                 uport->ops->break_ctl(uport, break_state);
994         mutex_unlock(&port->mutex);
995         return 0;
998 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1000         struct uart_port *uport = state->uart_port;
1001         struct tty_port *port = &state->port;
1002         int flags, ret;
1004         if (!capable(CAP_SYS_ADMIN))
1005                 return -EPERM;
1007         /*
1008          * Take the per-port semaphore.  This prevents count from
1009          * changing, and hence any extra opens of the port while
1010          * we're auto-configuring.
1011          */
1012         if (mutex_lock_interruptible(&port->mutex))
1013                 return -ERESTARTSYS;
1015         ret = -EBUSY;
1016         if (tty_port_users(port) == 1) {
1017                 uart_shutdown(tty, state);
1019                 /*
1020                  * If we already have a port type configured,
1021                  * we must release its resources.
1022                  */
1023                 if (uport->type != PORT_UNKNOWN)
1024                         uport->ops->release_port(uport);
1026                 flags = UART_CONFIG_TYPE;
1027                 if (uport->flags & UPF_AUTO_IRQ)
1028                         flags |= UART_CONFIG_IRQ;
1030                 /*
1031                  * This will claim the ports resources if
1032                  * a port is found.
1033                  */
1034                 uport->ops->config_port(uport, flags);
1036                 ret = uart_startup(tty, state, 1);
1037         }
1038         mutex_unlock(&port->mutex);
1039         return ret;
1042 /*
1043  * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1044  * - mask passed in arg for lines of interest
1045  *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1046  * Caller should use TIOCGICOUNT to see which one it was
1047  *
1048  * FIXME: This wants extracting into a common all driver implementation
1049  * of TIOCMWAIT using tty_port.
1050  */
1051 static int
1052 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1054         struct uart_port *uport = state->uart_port;
1055         struct tty_port *port = &state->port;
1056         DECLARE_WAITQUEUE(wait, current);
1057         struct uart_icount cprev, cnow;
1058         int ret;
1060         /*
1061          * note the counters on entry
1062          */
1063         spin_lock_irq(&uport->lock);
1064         memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1066         /*
1067          * Force modem status interrupts on
1068          */
1069         uport->ops->enable_ms(uport);
1070         spin_unlock_irq(&uport->lock);
1072         add_wait_queue(&port->delta_msr_wait, &wait);
1073         for (;;) {
1074                 spin_lock_irq(&uport->lock);
1075                 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1076                 spin_unlock_irq(&uport->lock);
1078                 set_current_state(TASK_INTERRUPTIBLE);
1080                 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1081                     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1082                     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1083                     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1084                         ret = 0;
1085                         break;
1086                 }
1088                 schedule();
1090                 /* see if a signal did it */
1091                 if (signal_pending(current)) {
1092                         ret = -ERESTARTSYS;
1093                         break;
1094                 }
1096                 cprev = cnow;
1097         }
1099         current->state = TASK_RUNNING;
1100         remove_wait_queue(&port->delta_msr_wait, &wait);
1102         return ret;
1105 /*
1106  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1107  * Return: write counters to the user passed counter struct
1108  * NB: both 1->0 and 0->1 transitions are counted except for
1109  *     RI where only 0->1 is counted.
1110  */
1111 static int uart_get_icount(struct tty_struct *tty,
1112                           struct serial_icounter_struct *icount)
1114         struct uart_state *state = tty->driver_data;
1115         struct uart_icount cnow;
1116         struct uart_port *uport = state->uart_port;
1118         spin_lock_irq(&uport->lock);
1119         memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1120         spin_unlock_irq(&uport->lock);
1122         icount->cts         = cnow.cts;
1123         icount->dsr         = cnow.dsr;
1124         icount->rng         = cnow.rng;
1125         icount->dcd         = cnow.dcd;
1126         icount->rx          = cnow.rx;
1127         icount->tx          = cnow.tx;
1128         icount->frame       = cnow.frame;
1129         icount->overrun     = cnow.overrun;
1130         icount->parity      = cnow.parity;
1131         icount->brk         = cnow.brk;
1132         icount->buf_overrun = cnow.buf_overrun;
1134         return 0;
1137 /*
1138  * Called via sys_ioctl.  We can use spin_lock_irq() here.
1139  */
1140 static int
1141 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1142            unsigned long arg)
1144         struct uart_state *state = tty->driver_data;
1145         struct tty_port *port = &state->port;
1146         void __user *uarg = (void __user *)arg;
1147         int ret = -ENOIOCTLCMD;
1150         /*
1151          * These ioctls don't rely on the hardware to be present.
1152          */
1153         switch (cmd) {
1154         case TIOCGSERIAL:
1155                 ret = uart_get_info_user(port, uarg);
1156                 break;
1158         case TIOCSSERIAL:
1159                 ret = uart_set_info_user(tty, state, uarg);
1160                 break;
1162         case TIOCSERCONFIG:
1163                 ret = uart_do_autoconfig(tty, state);
1164                 break;
1166         case TIOCSERGWILD: /* obsolete */
1167         case TIOCSERSWILD: /* obsolete */
1168                 ret = 0;
1169                 break;
1170         }
1172         if (ret != -ENOIOCTLCMD)
1173                 goto out;
1175         if (tty->flags & (1 << TTY_IO_ERROR)) {
1176                 ret = -EIO;
1177                 goto out;
1178         }
1180         /*
1181          * The following should only be used when hardware is present.
1182          */
1183         switch (cmd) {
1184         case TIOCMIWAIT:
1185                 ret = uart_wait_modem_status(state, arg);
1186                 break;
1187         }
1189         if (ret != -ENOIOCTLCMD)
1190                 goto out;
1192         mutex_lock(&port->mutex);
1194         if (tty->flags & (1 << TTY_IO_ERROR)) {
1195                 ret = -EIO;
1196                 goto out_up;
1197         }
1199         /*
1200          * All these rely on hardware being present and need to be
1201          * protected against the tty being hung up.
1202          */
1203         switch (cmd) {
1204         case TIOCSERGETLSR: /* Get line status register */
1205                 ret = uart_get_lsr_info(tty, state, uarg);
1206                 break;
1208         default: {
1209                 struct uart_port *uport = state->uart_port;
1210                 if (uport->ops->ioctl)
1211                         ret = uport->ops->ioctl(uport, cmd, arg);
1212                 break;
1213         }
1214         }
1215 out_up:
1216         mutex_unlock(&port->mutex);
1217 out:
1218         return ret;
1221 static void uart_set_ldisc(struct tty_struct *tty)
1223         struct uart_state *state = tty->driver_data;
1224         struct uart_port *uport = state->uart_port;
1226         if (uport->ops->set_ldisc)
1227                 uport->ops->set_ldisc(uport, tty->termios.c_line);
1230 static void uart_set_termios(struct tty_struct *tty,
1231                                                 struct ktermios *old_termios)
1233         struct uart_state *state = tty->driver_data;
1234         struct uart_port *uport = state->uart_port;
1235         unsigned long flags;
1236         unsigned int cflag = tty->termios.c_cflag;
1237         unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1238         bool sw_changed = false;
1240         /*
1241          * Drivers doing software flow control also need to know
1242          * about changes to these input settings.
1243          */
1244         if (uport->flags & UPF_SOFT_FLOW) {
1245                 iflag_mask |= IXANY|IXON|IXOFF;
1246                 sw_changed =
1247                    tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1248                    tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1249         }
1251         /*
1252          * These are the bits that are used to setup various
1253          * flags in the low level driver. We can ignore the Bfoo
1254          * bits in c_cflag; c_[io]speed will always be set
1255          * appropriately by set_termios() in tty_ioctl.c
1256          */
1257         if ((cflag ^ old_termios->c_cflag) == 0 &&
1258             tty->termios.c_ospeed == old_termios->c_ospeed &&
1259             tty->termios.c_ispeed == old_termios->c_ispeed &&
1260             ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1261             !sw_changed) {
1262                 return;
1263         }
1265         uart_change_speed(tty, state, old_termios);
1267         /* Handle transition to B0 status */
1268         if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1269                 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1270         /* Handle transition away from B0 status */
1271         else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1272                 unsigned int mask = TIOCM_DTR;
1273                 if (!(cflag & CRTSCTS) ||
1274                     !test_bit(TTY_THROTTLED, &tty->flags))
1275                         mask |= TIOCM_RTS;
1276                 uart_set_mctrl(uport, mask);
1277         }
1279         /*
1280          * If the port is doing h/w assisted flow control, do nothing.
1281          * We assume that tty->hw_stopped has never been set.
1282          */
1283         if (uport->flags & UPF_HARD_FLOW)
1284                 return;
1286         /* Handle turning off CRTSCTS */
1287         if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1288                 spin_lock_irqsave(&uport->lock, flags);
1289                 tty->hw_stopped = 0;
1290                 __uart_start(tty);
1291                 spin_unlock_irqrestore(&uport->lock, flags);
1292         }
1293         /* Handle turning on CRTSCTS */
1294         else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1295                 spin_lock_irqsave(&uport->lock, flags);
1296                 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
1297                         tty->hw_stopped = 1;
1298                         uport->ops->stop_tx(uport);
1299                 }
1300                 spin_unlock_irqrestore(&uport->lock, flags);
1301         }
1304 /*
1305  * In 2.4.5, calls to this will be serialized via the BKL in
1306  *  linux/drivers/char/tty_io.c:tty_release()
1307  *  linux/drivers/char/tty_io.c:do_tty_handup()
1308  */
1309 static void uart_close(struct tty_struct *tty, struct file *filp)
1311         struct uart_state *state = tty->driver_data;
1312         struct tty_port *port;
1313         struct uart_port *uport;
1314         unsigned long flags;
1316         if (!state)
1317                 return;
1319         uport = state->uart_port;
1320         port = &state->port;
1322         pr_debug("uart_close(%d) called\n", uport->line);
1324         if (tty_port_close_start(port, tty, filp) == 0)
1325                 return;
1327         /*
1328          * At this point, we stop accepting input.  To do this, we
1329          * disable the receive line status interrupts.
1330          */
1331         if (port->flags & ASYNC_INITIALIZED) {
1332                 unsigned long flags;
1333                 spin_lock_irqsave(&uport->lock, flags);
1334                 uport->ops->stop_rx(uport);
1335                 spin_unlock_irqrestore(&uport->lock, flags);
1336                 /*
1337                  * Before we drop DTR, make sure the UART transmitter
1338                  * has completely drained; this is especially
1339                  * important if there is a transmit FIFO!
1340                  */
1341                 uart_wait_until_sent(tty, uport->timeout);
1342         }
1344         mutex_lock(&port->mutex);
1345         uart_shutdown(tty, state);
1346         uart_flush_buffer(tty);
1348         tty_ldisc_flush(tty);
1350         tty_port_tty_set(port, NULL);
1351         spin_lock_irqsave(&port->lock, flags);
1352         tty->closing = 0;
1354         if (port->blocked_open) {
1355                 spin_unlock_irqrestore(&port->lock, flags);
1356                 if (port->close_delay)
1357                         msleep_interruptible(
1358                                         jiffies_to_msecs(port->close_delay));
1359                 spin_lock_irqsave(&port->lock, flags);
1360         } else if (!uart_console(uport)) {
1361                 spin_unlock_irqrestore(&port->lock, flags);
1362                 uart_change_pm(state, 3);
1363                 spin_lock_irqsave(&port->lock, flags);
1364         }
1366         /*
1367          * Wake up anyone trying to open this port.
1368          */
1369         clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1370         clear_bit(ASYNCB_CLOSING, &port->flags);
1371         spin_unlock_irqrestore(&port->lock, flags);
1372         wake_up_interruptible(&port->open_wait);
1373         wake_up_interruptible(&port->close_wait);
1375         mutex_unlock(&port->mutex);
1378 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1380         struct uart_state *state = tty->driver_data;
1381         struct uart_port *port = state->uart_port;
1382         unsigned long char_time, expire;
1384         if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1385                 return;
1387         /*
1388          * Set the check interval to be 1/5 of the estimated time to
1389          * send a single character, and make it at least 1.  The check
1390          * interval should also be less than the timeout.
1391          *
1392          * Note: we have to use pretty tight timings here to satisfy
1393          * the NIST-PCTS.
1394          */
1395         char_time = (port->timeout - HZ/50) / port->fifosize;
1396         char_time = char_time / 5;
1397         if (char_time == 0)
1398                 char_time = 1;
1399         if (timeout && timeout < char_time)
1400                 char_time = timeout;
1402         /*
1403          * If the transmitter hasn't cleared in twice the approximate
1404          * amount of time to send the entire FIFO, it probably won't
1405          * ever clear.  This assumes the UART isn't doing flow
1406          * control, which is currently the case.  Hence, if it ever
1407          * takes longer than port->timeout, this is probably due to a
1408          * UART bug of some kind.  So, we clamp the timeout parameter at
1409          * 2*port->timeout.
1410          */
1411         if (timeout == 0 || timeout > 2 * port->timeout)
1412                 timeout = 2 * port->timeout;
1414         expire = jiffies + timeout;
1416         pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1417                 port->line, jiffies, expire);
1419         /*
1420          * Check whether the transmitter is empty every 'char_time'.
1421          * 'timeout' / 'expire' give us the maximum amount of time
1422          * we wait.
1423          */
1424         while (!port->ops->tx_empty(port)) {
1425                 msleep_interruptible(jiffies_to_msecs(char_time));
1426                 if (signal_pending(current))
1427                         break;
1428                 if (time_after(jiffies, expire))
1429                         break;
1430         }
1433 /*
1434  * This is called with the BKL held in
1435  *  linux/drivers/char/tty_io.c:do_tty_hangup()
1436  * We're called from the eventd thread, so we can sleep for
1437  * a _short_ time only.
1438  */
1439 static void uart_hangup(struct tty_struct *tty)
1441         struct uart_state *state = tty->driver_data;
1442         struct tty_port *port = &state->port;
1443         unsigned long flags;
1445         pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1447         mutex_lock(&port->mutex);
1448         if (port->flags & ASYNC_NORMAL_ACTIVE) {
1449                 uart_flush_buffer(tty);
1450                 uart_shutdown(tty, state);
1451                 spin_lock_irqsave(&port->lock, flags);
1452                 port->count = 0;
1453                 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1454                 spin_unlock_irqrestore(&port->lock, flags);
1455                 tty_port_tty_set(port, NULL);
1456                 wake_up_interruptible(&port->open_wait);
1457                 wake_up_interruptible(&port->delta_msr_wait);
1458         }
1459         mutex_unlock(&port->mutex);
1462 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1464         return 0;
1467 static void uart_port_shutdown(struct tty_port *port)
1469         struct uart_state *state = container_of(port, struct uart_state, port);
1470         struct uart_port *uport = state->uart_port;
1472         /*
1473          * clear delta_msr_wait queue to avoid mem leaks: we may free
1474          * the irq here so the queue might never be woken up.  Note
1475          * that we won't end up waiting on delta_msr_wait again since
1476          * any outstanding file descriptors should be pointing at
1477          * hung_up_tty_fops now.
1478          */
1479         wake_up_interruptible(&port->delta_msr_wait);
1481         /*
1482          * Free the IRQ and disable the port.
1483          */
1484         uport->ops->shutdown(uport);
1486         /*
1487          * Ensure that the IRQ handler isn't running on another CPU.
1488          */
1489         synchronize_irq(uport->irq);
1492 static int uart_carrier_raised(struct tty_port *port)
1494         struct uart_state *state = container_of(port, struct uart_state, port);
1495         struct uart_port *uport = state->uart_port;
1496         int mctrl;
1497         spin_lock_irq(&uport->lock);
1498         uport->ops->enable_ms(uport);
1499         mctrl = uport->ops->get_mctrl(uport);
1500         spin_unlock_irq(&uport->lock);
1501         if (mctrl & TIOCM_CAR)
1502                 return 1;
1503         return 0;
1506 static void uart_dtr_rts(struct tty_port *port, int onoff)
1508         struct uart_state *state = container_of(port, struct uart_state, port);
1509         struct uart_port *uport = state->uart_port;
1511         if (onoff)
1512                 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1513         else
1514                 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1517 /*
1518  * calls to uart_open are serialised by the BKL in
1519  *   fs/char_dev.c:chrdev_open()
1520  * Note that if this fails, then uart_close() _will_ be called.
1521  *
1522  * In time, we want to scrap the "opening nonpresent ports"
1523  * behaviour and implement an alternative way for setserial
1524  * to set base addresses/ports/types.  This will allow us to
1525  * get rid of a certain amount of extra tests.
1526  */
1527 static int uart_open(struct tty_struct *tty, struct file *filp)
1529         struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1530         int retval, line = tty->index;
1531         struct uart_state *state = drv->state + line;
1532         struct tty_port *port = &state->port;
1534         pr_debug("uart_open(%d) called\n", line);
1536         /*
1537          * We take the semaphore here to guarantee that we won't be re-entered
1538          * while allocating the state structure, or while we request any IRQs
1539          * that the driver may need.  This also has the nice side-effect that
1540          * it delays the action of uart_hangup, so we can guarantee that
1541          * state->port.tty will always contain something reasonable.
1542          */
1543         if (mutex_lock_interruptible(&port->mutex)) {
1544                 retval = -ERESTARTSYS;
1545                 goto end;
1546         }
1548         port->count++;
1549         if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1550                 retval = -ENXIO;
1551                 goto err_dec_count;
1552         }
1554         /*
1555          * Once we set tty->driver_data here, we are guaranteed that
1556          * uart_close() will decrement the driver module use count.
1557          * Any failures from here onwards should not touch the count.
1558          */
1559         tty->driver_data = state;
1560         state->uart_port->state = state;
1561         tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1562         tty_port_tty_set(port, tty);
1564         /*
1565          * If the port is in the middle of closing, bail out now.
1566          */
1567         if (tty_hung_up_p(filp)) {
1568                 retval = -EAGAIN;
1569                 goto err_dec_count;
1570         }
1572         /*
1573          * Make sure the device is in D0 state.
1574          */
1575         if (port->count == 1)
1576                 uart_change_pm(state, 0);
1578         /*
1579          * Start up the serial port.
1580          */
1581         retval = uart_startup(tty, state, 0);
1583         /*
1584          * If we succeeded, wait until the port is ready.
1585          */
1586         mutex_unlock(&port->mutex);
1587         if (retval == 0)
1588                 retval = tty_port_block_til_ready(port, tty, filp);
1590 end:
1591         return retval;
1592 err_dec_count:
1593         port->count--;
1594         mutex_unlock(&port->mutex);
1595         goto end;
1598 static const char *uart_type(struct uart_port *port)
1600         const char *str = NULL;
1602         if (port->ops->type)
1603                 str = port->ops->type(port);
1605         if (!str)
1606                 str = "unknown";
1608         return str;
1611 #ifdef CONFIG_PROC_FS
1613 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1615         struct uart_state *state = drv->state + i;
1616         struct tty_port *port = &state->port;
1617         int pm_state;
1618         struct uart_port *uport = state->uart_port;
1619         char stat_buf[32];
1620         unsigned int status;
1621         int mmio;
1623         if (!uport)
1624                 return;
1626         mmio = uport->iotype >= UPIO_MEM;
1627         seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1628                         uport->line, uart_type(uport),
1629                         mmio ? "mmio:0x" : "port:",
1630                         mmio ? (unsigned long long)uport->mapbase
1631                              : (unsigned long long)uport->iobase,
1632                         uport->irq);
1634         if (uport->type == PORT_UNKNOWN) {
1635                 seq_putc(m, '\n');
1636                 return;
1637         }
1639         if (capable(CAP_SYS_ADMIN)) {
1640                 mutex_lock(&port->mutex);
1641                 pm_state = state->pm_state;
1642                 if (pm_state)
1643                         uart_change_pm(state, 0);
1644                 spin_lock_irq(&uport->lock);
1645                 status = uport->ops->get_mctrl(uport);
1646                 spin_unlock_irq(&uport->lock);
1647                 if (pm_state)
1648                         uart_change_pm(state, pm_state);
1649                 mutex_unlock(&port->mutex);
1651                 seq_printf(m, " tx:%d rx:%d",
1652                                 uport->icount.tx, uport->icount.rx);
1653                 if (uport->icount.frame)
1654                         seq_printf(m, " fe:%d",
1655                                 uport->icount.frame);
1656                 if (uport->icount.parity)
1657                         seq_printf(m, " pe:%d",
1658                                 uport->icount.parity);
1659                 if (uport->icount.brk)
1660                         seq_printf(m, " brk:%d",
1661                                 uport->icount.brk);
1662                 if (uport->icount.overrun)
1663                         seq_printf(m, " oe:%d",
1664                                 uport->icount.overrun);
1666 #define INFOBIT(bit, str) \
1667         if (uport->mctrl & (bit)) \
1668                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1669                         strlen(stat_buf) - 2)
1670 #define STATBIT(bit, str) \
1671         if (status & (bit)) \
1672                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1673                        strlen(stat_buf) - 2)
1675                 stat_buf[0] = '\0';
1676                 stat_buf[1] = '\0';
1677                 INFOBIT(TIOCM_RTS, "|RTS");
1678                 STATBIT(TIOCM_CTS, "|CTS");
1679                 INFOBIT(TIOCM_DTR, "|DTR");
1680                 STATBIT(TIOCM_DSR, "|DSR");
1681                 STATBIT(TIOCM_CAR, "|CD");
1682                 STATBIT(TIOCM_RNG, "|RI");
1683                 if (stat_buf[0])
1684                         stat_buf[0] = ' ';
1686                 seq_puts(m, stat_buf);
1687         }
1688         seq_putc(m, '\n');
1689 #undef STATBIT
1690 #undef INFOBIT
1693 static int uart_proc_show(struct seq_file *m, void *v)
1695         struct tty_driver *ttydrv = m->private;
1696         struct uart_driver *drv = ttydrv->driver_state;
1697         int i;
1699         seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1700                         "", "", "");
1701         for (i = 0; i < drv->nr; i++)
1702                 uart_line_info(m, drv, i);
1703         return 0;
1706 static int uart_proc_open(struct inode *inode, struct file *file)
1708         return single_open(file, uart_proc_show, PDE(inode)->data);
1711 static const struct file_operations uart_proc_fops = {
1712         .owner          = THIS_MODULE,
1713         .open           = uart_proc_open,
1714         .read           = seq_read,
1715         .llseek         = seq_lseek,
1716         .release        = single_release,
1717 };
1718 #endif
1720 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1721 /*
1722  *      uart_console_write - write a console message to a serial port
1723  *      @port: the port to write the message
1724  *      @s: array of characters
1725  *      @count: number of characters in string to write
1726  *      @write: function to write character to port
1727  */
1728 void uart_console_write(struct uart_port *port, const char *s,
1729                         unsigned int count,
1730                         void (*putchar)(struct uart_port *, int))
1732         unsigned int i;
1734         for (i = 0; i < count; i++, s++) {
1735                 if (*s == '\n')
1736                         putchar(port, '\r');
1737                 putchar(port, *s);
1738         }
1740 EXPORT_SYMBOL_GPL(uart_console_write);
1742 /*
1743  *      Check whether an invalid uart number has been specified, and
1744  *      if so, search for the first available port that does have
1745  *      console support.
1746  */
1747 struct uart_port * __init
1748 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1750         int idx = co->index;
1752         if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1753                                      ports[idx].membase == NULL))
1754                 for (idx = 0; idx < nr; idx++)
1755                         if (ports[idx].iobase != 0 ||
1756                             ports[idx].membase != NULL)
1757                                 break;
1759         co->index = idx;
1761         return ports + idx;
1764 /**
1765  *      uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1766  *      @options: pointer to option string
1767  *      @baud: pointer to an 'int' variable for the baud rate.
1768  *      @parity: pointer to an 'int' variable for the parity.
1769  *      @bits: pointer to an 'int' variable for the number of data bits.
1770  *      @flow: pointer to an 'int' variable for the flow control character.
1771  *
1772  *      uart_parse_options decodes a string containing the serial console
1773  *      options.  The format of the string is <baud><parity><bits><flow>,
1774  *      eg: 115200n8r
1775  */
1776 void
1777 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1779         char *s = options;
1781         *baud = simple_strtoul(s, NULL, 10);
1782         while (*s >= '0' && *s <= '9')
1783                 s++;
1784         if (*s)
1785                 *parity = *s++;
1786         if (*s)
1787                 *bits = *s++ - '0';
1788         if (*s)
1789                 *flow = *s;
1791 EXPORT_SYMBOL_GPL(uart_parse_options);
1793 struct baud_rates {
1794         unsigned int rate;
1795         unsigned int cflag;
1796 };
1798 static const struct baud_rates baud_rates[] = {
1799         { 921600, B921600 },
1800         { 460800, B460800 },
1801         { 230400, B230400 },
1802         { 115200, B115200 },
1803         {  57600, B57600  },
1804         {  38400, B38400  },
1805         {  19200, B19200  },
1806         {   9600, B9600   },
1807         {   4800, B4800   },
1808         {   2400, B2400   },
1809         {   1200, B1200   },
1810         {      0, B38400  }
1811 };
1813 /**
1814  *      uart_set_options - setup the serial console parameters
1815  *      @port: pointer to the serial ports uart_port structure
1816  *      @co: console pointer
1817  *      @baud: baud rate
1818  *      @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1819  *      @bits: number of data bits
1820  *      @flow: flow control character - 'r' (rts)
1821  */
1822 int
1823 uart_set_options(struct uart_port *port, struct console *co,
1824                  int baud, int parity, int bits, int flow)
1826         struct ktermios termios;
1827         static struct ktermios dummy;
1828         int i;
1830         /*
1831          * Ensure that the serial console lock is initialised
1832          * early.
1833          */
1834         spin_lock_init(&port->lock);
1835         lockdep_set_class(&port->lock, &port_lock_key);
1837         memset(&termios, 0, sizeof(struct ktermios));
1839         termios.c_cflag = CREAD | HUPCL | CLOCAL;
1841         /*
1842          * Construct a cflag setting.
1843          */
1844         for (i = 0; baud_rates[i].rate; i++)
1845                 if (baud_rates[i].rate <= baud)
1846                         break;
1848         termios.c_cflag |= baud_rates[i].cflag;
1850         if (bits == 7)
1851                 termios.c_cflag |= CS7;
1852         else
1853                 termios.c_cflag |= CS8;
1855         switch (parity) {
1856         case 'o': case 'O':
1857                 termios.c_cflag |= PARODD;
1858                 /*fall through*/
1859         case 'e': case 'E':
1860                 termios.c_cflag |= PARENB;
1861                 break;
1862         }
1864         if (flow == 'r')
1865                 termios.c_cflag |= CRTSCTS;
1867         /*
1868          * some uarts on other side don't support no flow control.
1869          * So we set * DTR in host uart to make them happy
1870          */
1871         port->mctrl |= TIOCM_DTR;
1873         port->ops->set_termios(port, &termios, &dummy);
1874         /*
1875          * Allow the setting of the UART parameters with a NULL console
1876          * too:
1877          */
1878         if (co)
1879                 co->cflag = termios.c_cflag;
1881         return 0;
1883 EXPORT_SYMBOL_GPL(uart_set_options);
1884 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1886 /**
1887  * uart_change_pm - set power state of the port
1888  *
1889  * @state: port descriptor
1890  * @pm_state: new state
1891  *
1892  * Locking: port->mutex has to be held
1893  */
1894 static void uart_change_pm(struct uart_state *state, int pm_state)
1896         struct uart_port *port = state->uart_port;
1898         if (state->pm_state != pm_state) {
1899                 if (port->ops->pm)
1900                         port->ops->pm(port, pm_state, state->pm_state);
1901                 state->pm_state = pm_state;
1902         }
1905 struct uart_match {
1906         struct uart_port *port;
1907         struct uart_driver *driver;
1908 };
1910 static int serial_match_port(struct device *dev, void *data)
1912         struct uart_match *match = data;
1913         struct tty_driver *tty_drv = match->driver->tty_driver;
1914         dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1915                 match->port->line;
1917         return dev->devt == devt; /* Actually, only one tty per port */
1920 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1922         struct uart_state *state = drv->state + uport->line;
1923         struct tty_port *port = &state->port;
1924         struct device *tty_dev;
1925         struct uart_match match = {uport, drv};
1927         mutex_lock(&port->mutex);
1929         tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1930         if (device_may_wakeup(tty_dev)) {
1931                 if (!enable_irq_wake(uport->irq))
1932                         uport->irq_wake = 1;
1933                 put_device(tty_dev);
1934                 mutex_unlock(&port->mutex);
1935                 return 0;
1936         }
1937         put_device(tty_dev);
1939         if (console_suspend_enabled || !uart_console(uport))
1940                 uport->suspended = 1;
1942         if (port->flags & ASYNC_INITIALIZED) {
1943                 const struct uart_ops *ops = uport->ops;
1944                 int tries;
1946                 if (console_suspend_enabled || !uart_console(uport)) {
1947                         set_bit(ASYNCB_SUSPENDED, &port->flags);
1948                         clear_bit(ASYNCB_INITIALIZED, &port->flags);
1950                         spin_lock_irq(&uport->lock);
1951                         ops->stop_tx(uport);
1952                         ops->set_mctrl(uport, 0);
1953                         ops->stop_rx(uport);
1954                         spin_unlock_irq(&uport->lock);
1955                 }
1957                 /*
1958                  * Wait for the transmitter to empty.
1959                  */
1960                 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1961                         msleep(10);
1962                 if (!tries)
1963                         printk(KERN_ERR "%s%s%s%d: Unable to drain "
1964                                         "transmitter\n",
1965                                uport->dev ? dev_name(uport->dev) : "",
1966                                uport->dev ? ": " : "",
1967                                drv->dev_name,
1968                                drv->tty_driver->name_base + uport->line);
1970                 if (console_suspend_enabled || !uart_console(uport))
1971                         ops->shutdown(uport);
1972         }
1974         /*
1975          * Disable the console device before suspending.
1976          */
1977         if (console_suspend_enabled && uart_console(uport))
1978                 console_stop(uport->cons);
1980         if (console_suspend_enabled || !uart_console(uport))
1981                 uart_change_pm(state, 3);
1983         mutex_unlock(&port->mutex);
1985         return 0;
1988 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1990         struct uart_state *state = drv->state + uport->line;
1991         struct tty_port *port = &state->port;
1992         struct device *tty_dev;
1993         struct uart_match match = {uport, drv};
1994         struct ktermios termios;
1996         mutex_lock(&port->mutex);
1998         tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1999         if (!uport->suspended && device_may_wakeup(tty_dev)) {
2000                 if (uport->irq_wake) {
2001                         disable_irq_wake(uport->irq);
2002                         uport->irq_wake = 0;
2003                 }
2004                 put_device(tty_dev);
2005                 mutex_unlock(&port->mutex);
2006                 return 0;
2007         }
2008         put_device(tty_dev);
2009         uport->suspended = 0;
2011         /*
2012          * Re-enable the console device after suspending.
2013          */
2014         if (uart_console(uport)) {
2015                 /*
2016                  * First try to use the console cflag setting.
2017                  */
2018                 memset(&termios, 0, sizeof(struct ktermios));
2019                 termios.c_cflag = uport->cons->cflag;
2021                 /*
2022                  * If that's unset, use the tty termios setting.
2023                  */
2024                 if (port->tty && termios.c_cflag == 0)
2025                         termios = port->tty->termios;
2027                 if (console_suspend_enabled)
2028                         uart_change_pm(state, 0);
2029                 uport->ops->set_termios(uport, &termios, NULL);
2030                 if (console_suspend_enabled)
2031                         console_start(uport->cons);
2032         }
2034         if (port->flags & ASYNC_SUSPENDED) {
2035                 const struct uart_ops *ops = uport->ops;
2036                 int ret;
2038                 uart_change_pm(state, 0);
2039                 spin_lock_irq(&uport->lock);
2040                 ops->set_mctrl(uport, 0);
2041                 spin_unlock_irq(&uport->lock);
2042                 if (console_suspend_enabled || !uart_console(uport)) {
2043                         /* Protected by port mutex for now */
2044                         struct tty_struct *tty = port->tty;
2045                         ret = ops->startup(uport);
2046                         if (ret == 0) {
2047                                 if (tty)
2048                                         uart_change_speed(tty, state, NULL);
2049                                 spin_lock_irq(&uport->lock);
2050                                 ops->set_mctrl(uport, uport->mctrl);
2051                                 ops->start_tx(uport);
2052                                 spin_unlock_irq(&uport->lock);
2053                                 set_bit(ASYNCB_INITIALIZED, &port->flags);
2054                         } else {
2055                                 /*
2056                                  * Failed to resume - maybe hardware went away?
2057                                  * Clear the "initialized" flag so we won't try
2058                                  * to call the low level drivers shutdown method.
2059                                  */
2060                                 uart_shutdown(tty, state);
2061                         }
2062                 }
2064                 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2065         }
2067         mutex_unlock(&port->mutex);
2069         return 0;
2072 static inline void
2073 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2075         char address[64];
2077         switch (port->iotype) {
2078         case UPIO_PORT:
2079                 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2080                 break;
2081         case UPIO_HUB6:
2082                 snprintf(address, sizeof(address),
2083                          "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2084                 break;
2085         case UPIO_MEM:
2086         case UPIO_MEM32:
2087         case UPIO_AU:
2088         case UPIO_TSI:
2089                 snprintf(address, sizeof(address),
2090                          "MMIO 0x%llx", (unsigned long long)port->mapbase);
2091                 break;
2092         default:
2093                 strlcpy(address, "*unknown*", sizeof(address));
2094                 break;
2095         }
2097         printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2098                port->dev ? dev_name(port->dev) : "",
2099                port->dev ? ": " : "",
2100                drv->dev_name,
2101                drv->tty_driver->name_base + port->line,
2102                address, port->irq, uart_type(port));
2105 static void
2106 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2107                     struct uart_port *port)
2109         unsigned int flags;
2111         /*
2112          * If there isn't a port here, don't do anything further.
2113          */
2114         if (!port->iobase && !port->mapbase && !port->membase)
2115                 return;
2117         /*
2118          * Now do the auto configuration stuff.  Note that config_port
2119          * is expected to claim the resources and map the port for us.
2120          */
2121         flags = 0;
2122         if (port->flags & UPF_AUTO_IRQ)
2123                 flags |= UART_CONFIG_IRQ;
2124         if (port->flags & UPF_BOOT_AUTOCONF) {
2125                 if (!(port->flags & UPF_FIXED_TYPE)) {
2126                         port->type = PORT_UNKNOWN;
2127                         flags |= UART_CONFIG_TYPE;
2128                 }
2129                 port->ops->config_port(port, flags);
2130         }
2132         if (port->type != PORT_UNKNOWN) {
2133                 unsigned long flags;
2135                 uart_report_port(drv, port);
2137                 /* Power up port for set_mctrl() */
2138                 uart_change_pm(state, 0);
2140                 /*
2141                  * Ensure that the modem control lines are de-activated.
2142                  * keep the DTR setting that is set in uart_set_options()
2143                  * We probably don't need a spinlock around this, but
2144                  */
2145                 spin_lock_irqsave(&port->lock, flags);
2146                 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2147                 spin_unlock_irqrestore(&port->lock, flags);
2149                 /*
2150                  * If this driver supports console, and it hasn't been
2151                  * successfully registered yet, try to re-register it.
2152                  * It may be that the port was not available.
2153                  */
2154                 if (port->cons && !(port->cons->flags & CON_ENABLED))
2155                         register_console(port->cons);
2157                 /*
2158                  * Power down all ports by default, except the
2159                  * console if we have one.
2160                  */
2161                 if (!uart_console(port))
2162                         uart_change_pm(state, 3);
2163         }
2166 #ifdef CONFIG_CONSOLE_POLL
2168 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2170         struct uart_driver *drv = driver->driver_state;
2171         struct uart_state *state = drv->state + line;
2172         struct uart_port *port;
2173         int baud = 9600;
2174         int bits = 8;
2175         int parity = 'n';
2176         int flow = 'n';
2177         int ret;
2179         if (!state || !state->uart_port)
2180                 return -1;
2182         port = state->uart_port;
2183         if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2184                 return -1;
2186         if (port->ops->poll_init) {
2187                 struct tty_port *tport = &state->port;
2189                 ret = 0;
2190                 mutex_lock(&tport->mutex);
2191                 /*
2192                  * We don't set ASYNCB_INITIALIZED as we only initialized the
2193                  * hw, e.g. state->xmit is still uninitialized.
2194                  */
2195                 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2196                         ret = port->ops->poll_init(port);
2197                 mutex_unlock(&tport->mutex);
2198                 if (ret)
2199                         return ret;
2200         }
2202         if (options) {
2203                 uart_parse_options(options, &baud, &parity, &bits, &flow);
2204                 return uart_set_options(port, NULL, baud, parity, bits, flow);
2205         }
2207         return 0;
2210 static int uart_poll_get_char(struct tty_driver *driver, int line)
2212         struct uart_driver *drv = driver->driver_state;
2213         struct uart_state *state = drv->state + line;
2214         struct uart_port *port;
2216         if (!state || !state->uart_port)
2217                 return -1;
2219         port = state->uart_port;
2220         return port->ops->poll_get_char(port);
2223 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2225         struct uart_driver *drv = driver->driver_state;
2226         struct uart_state *state = drv->state + line;
2227         struct uart_port *port;
2229         if (!state || !state->uart_port)
2230                 return;
2232         port = state->uart_port;
2233         port->ops->poll_put_char(port, ch);
2235 #endif
2237 static const struct tty_operations uart_ops = {
2238         .open           = uart_open,
2239         .close          = uart_close,
2240         .write          = uart_write,
2241         .put_char       = uart_put_char,
2242         .flush_chars    = uart_flush_chars,
2243         .write_room     = uart_write_room,
2244         .chars_in_buffer= uart_chars_in_buffer,
2245         .flush_buffer   = uart_flush_buffer,
2246         .ioctl          = uart_ioctl,
2247         .throttle       = uart_throttle,
2248         .unthrottle     = uart_unthrottle,
2249         .send_xchar     = uart_send_xchar,
2250         .set_termios    = uart_set_termios,
2251         .set_ldisc      = uart_set_ldisc,
2252         .stop           = uart_stop,
2253         .start          = uart_start,
2254         .hangup         = uart_hangup,
2255         .break_ctl      = uart_break_ctl,
2256         .wait_until_sent= uart_wait_until_sent,
2257 #ifdef CONFIG_PROC_FS
2258         .proc_fops      = &uart_proc_fops,
2259 #endif
2260         .tiocmget       = uart_tiocmget,
2261         .tiocmset       = uart_tiocmset,
2262         .get_icount     = uart_get_icount,
2263 #ifdef CONFIG_CONSOLE_POLL
2264         .poll_init      = uart_poll_init,
2265         .poll_get_char  = uart_poll_get_char,
2266         .poll_put_char  = uart_poll_put_char,
2267 #endif
2268 };
2270 static const struct tty_port_operations uart_port_ops = {
2271         .activate       = uart_port_activate,
2272         .shutdown       = uart_port_shutdown,
2273         .carrier_raised = uart_carrier_raised,
2274         .dtr_rts        = uart_dtr_rts,
2275 };
2277 /**
2278  *      uart_register_driver - register a driver with the uart core layer
2279  *      @drv: low level driver structure
2280  *
2281  *      Register a uart driver with the core driver.  We in turn register
2282  *      with the tty layer, and initialise the core driver per-port state.
2283  *
2284  *      We have a proc file in /proc/tty/driver which is named after the
2285  *      normal driver.
2286  *
2287  *      drv->port should be NULL, and the per-port structures should be
2288  *      registered using uart_add_one_port after this call has succeeded.
2289  */
2290 int uart_register_driver(struct uart_driver *drv)
2292         struct tty_driver *normal;
2293         int i, retval;
2295         BUG_ON(drv->state);
2297         /*
2298          * Maybe we should be using a slab cache for this, especially if
2299          * we have a large number of ports to handle.
2300          */
2301         drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2302         if (!drv->state)
2303                 goto out;
2305         normal = alloc_tty_driver(drv->nr);
2306         if (!normal)
2307                 goto out_kfree;
2309         drv->tty_driver = normal;
2311         normal->driver_name     = drv->driver_name;
2312         normal->name            = drv->dev_name;
2313         normal->major           = drv->major;
2314         normal->minor_start     = drv->minor;
2315         normal->type            = TTY_DRIVER_TYPE_SERIAL;
2316         normal->subtype         = SERIAL_TYPE_NORMAL;
2317         normal->init_termios    = tty_std_termios;
2318         normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2319         normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2320         normal->flags           = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2321         normal->driver_state    = drv;
2322         tty_set_operations(normal, &uart_ops);
2324         /*
2325          * Initialise the UART state(s).
2326          */
2327         for (i = 0; i < drv->nr; i++) {
2328                 struct uart_state *state = drv->state + i;
2329                 struct tty_port *port = &state->port;
2331                 tty_port_init(port);
2332                 port->ops = &uart_port_ops;
2333                 port->close_delay     = HZ / 2; /* .5 seconds */
2334                 port->closing_wait    = 30 * HZ;/* 30 seconds */
2335         }
2337         retval = tty_register_driver(normal);
2338         if (retval >= 0)
2339                 return retval;
2341         for (i = 0; i < drv->nr; i++)
2342                 tty_port_destroy(&drv->state[i].port);
2343         put_tty_driver(normal);
2344 out_kfree:
2345         kfree(drv->state);
2346 out:
2347         return -ENOMEM;
2350 /**
2351  *      uart_unregister_driver - remove a driver from the uart core layer
2352  *      @drv: low level driver structure
2353  *
2354  *      Remove all references to a driver from the core driver.  The low
2355  *      level driver must have removed all its ports via the
2356  *      uart_remove_one_port() if it registered them with uart_add_one_port().
2357  *      (ie, drv->port == NULL)
2358  */
2359 void uart_unregister_driver(struct uart_driver *drv)
2361         struct tty_driver *p = drv->tty_driver;
2362         unsigned int i;
2364         tty_unregister_driver(p);
2365         put_tty_driver(p);
2366         for (i = 0; i < drv->nr; i++)
2367                 tty_port_destroy(&drv->state[i].port);
2368         kfree(drv->state);
2369         drv->state = NULL;
2370         drv->tty_driver = NULL;
2373 struct tty_driver *uart_console_device(struct console *co, int *index)
2375         struct uart_driver *p = co->data;
2376         *index = co->index;
2377         return p->tty_driver;
2380 static ssize_t uart_get_attr_uartclk(struct device *dev,
2381         struct device_attribute *attr, char *buf)
2383         struct serial_struct tmp;
2384         struct tty_port *port = dev_get_drvdata(dev);
2386         uart_get_info(port, &tmp);
2387         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2390 static ssize_t uart_get_attr_type(struct device *dev,
2391         struct device_attribute *attr, char *buf)
2393         struct serial_struct tmp;
2394         struct tty_port *port = dev_get_drvdata(dev);
2396         uart_get_info(port, &tmp);
2397         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2399 static ssize_t uart_get_attr_line(struct device *dev,
2400         struct device_attribute *attr, char *buf)
2402         struct serial_struct tmp;
2403         struct tty_port *port = dev_get_drvdata(dev);
2405         uart_get_info(port, &tmp);
2406         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2409 static ssize_t uart_get_attr_port(struct device *dev,
2410         struct device_attribute *attr, char *buf)
2412         struct serial_struct tmp;
2413         struct tty_port *port = dev_get_drvdata(dev);
2414         unsigned long ioaddr;
2416         uart_get_info(port, &tmp);
2417         ioaddr = tmp.port;
2418         if (HIGH_BITS_OFFSET)
2419                 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2420         return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2423 static ssize_t uart_get_attr_irq(struct device *dev,
2424         struct device_attribute *attr, char *buf)
2426         struct serial_struct tmp;
2427         struct tty_port *port = dev_get_drvdata(dev);
2429         uart_get_info(port, &tmp);
2430         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2433 static ssize_t uart_get_attr_flags(struct device *dev,
2434         struct device_attribute *attr, char *buf)
2436         struct serial_struct tmp;
2437         struct tty_port *port = dev_get_drvdata(dev);
2439         uart_get_info(port, &tmp);
2440         return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2443 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2444         struct device_attribute *attr, char *buf)
2446         struct serial_struct tmp;
2447         struct tty_port *port = dev_get_drvdata(dev);
2449         uart_get_info(port, &tmp);
2450         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2454 static ssize_t uart_get_attr_close_delay(struct device *dev,
2455         struct device_attribute *attr, char *buf)
2457         struct serial_struct tmp;
2458         struct tty_port *port = dev_get_drvdata(dev);
2460         uart_get_info(port, &tmp);
2461         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2465 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2466         struct device_attribute *attr, char *buf)
2468         struct serial_struct tmp;
2469         struct tty_port *port = dev_get_drvdata(dev);
2471         uart_get_info(port, &tmp);
2472         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2475 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2476         struct device_attribute *attr, char *buf)
2478         struct serial_struct tmp;
2479         struct tty_port *port = dev_get_drvdata(dev);
2481         uart_get_info(port, &tmp);
2482         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2485 static ssize_t uart_get_attr_io_type(struct device *dev,
2486         struct device_attribute *attr, char *buf)
2488         struct serial_struct tmp;
2489         struct tty_port *port = dev_get_drvdata(dev);
2491         uart_get_info(port, &tmp);
2492         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2495 static ssize_t uart_get_attr_iomem_base(struct device *dev,
2496         struct device_attribute *attr, char *buf)
2498         struct serial_struct tmp;
2499         struct tty_port *port = dev_get_drvdata(dev);
2501         uart_get_info(port, &tmp);
2502         return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2505 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2506         struct device_attribute *attr, char *buf)
2508         struct serial_struct tmp;
2509         struct tty_port *port = dev_get_drvdata(dev);
2511         uart_get_info(port, &tmp);
2512         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2515 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2516 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2517 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2518 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2519 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2520 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2521 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2522 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2523 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2524 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2525 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2526 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2527 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2529 static struct attribute *tty_dev_attrs[] = {
2530         &dev_attr_type.attr,
2531         &dev_attr_line.attr,
2532         &dev_attr_port.attr,
2533         &dev_attr_irq.attr,
2534         &dev_attr_flags.attr,
2535         &dev_attr_xmit_fifo_size.attr,
2536         &dev_attr_uartclk.attr,
2537         &dev_attr_close_delay.attr,
2538         &dev_attr_closing_wait.attr,
2539         &dev_attr_custom_divisor.attr,
2540         &dev_attr_io_type.attr,
2541         &dev_attr_iomem_base.attr,
2542         &dev_attr_iomem_reg_shift.attr,
2543         NULL,
2544         };
2546 static const struct attribute_group tty_dev_attr_group = {
2547         .attrs = tty_dev_attrs,
2548         };
2550 static const struct attribute_group *tty_dev_attr_groups[] = {
2551         &tty_dev_attr_group,
2552         NULL
2553         };
2556 /**
2557  *      uart_add_one_port - attach a driver-defined port structure
2558  *      @drv: pointer to the uart low level driver structure for this port
2559  *      @uport: uart port structure to use for this port.
2560  *
2561  *      This allows the driver to register its own uart_port structure
2562  *      with the core driver.  The main purpose is to allow the low
2563  *      level uart drivers to expand uart_port, rather than having yet
2564  *      more levels of structures.
2565  */
2566 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2568         struct uart_state *state;
2569         struct tty_port *port;
2570         int ret = 0;
2571         struct device *tty_dev;
2573         BUG_ON(in_interrupt());
2575         if (uport->line >= drv->nr)
2576                 return -EINVAL;
2578         state = drv->state + uport->line;
2579         port = &state->port;
2581         mutex_lock(&port_mutex);
2582         mutex_lock(&port->mutex);
2583         if (state->uart_port) {
2584                 ret = -EINVAL;
2585                 goto out;
2586         }
2588         state->uart_port = uport;
2589         state->pm_state = -1;
2591         uport->cons = drv->cons;
2592         uport->state = state;
2594         /*
2595          * If this port is a console, then the spinlock is already
2596          * initialised.
2597          */
2598         if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2599                 spin_lock_init(&uport->lock);
2600                 lockdep_set_class(&uport->lock, &port_lock_key);
2601         }
2603         uart_configure_port(drv, state, uport);
2605         /*
2606          * Register the port whether it's detected or not.  This allows
2607          * setserial to be used to alter this ports parameters.
2608          */
2609         tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2610                         uport->line, uport->dev, port, tty_dev_attr_groups);
2611         if (likely(!IS_ERR(tty_dev))) {
2612                 device_set_wakeup_capable(tty_dev, 1);
2613         } else {
2614                 printk(KERN_ERR "Cannot register tty device on line %d\n",
2615                        uport->line);
2616         }
2618         /*
2619          * Ensure UPF_DEAD is not set.
2620          */
2621         uport->flags &= ~UPF_DEAD;
2623  out:
2624         mutex_unlock(&port->mutex);
2625         mutex_unlock(&port_mutex);
2627         return ret;
2630 /**
2631  *      uart_remove_one_port - detach a driver defined port structure
2632  *      @drv: pointer to the uart low level driver structure for this port
2633  *      @uport: uart port structure for this port
2634  *
2635  *      This unhooks (and hangs up) the specified port structure from the
2636  *      core driver.  No further calls will be made to the low-level code
2637  *      for this port.
2638  */
2639 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2641         struct uart_state *state = drv->state + uport->line;
2642         struct tty_port *port = &state->port;
2644         BUG_ON(in_interrupt());
2646         if (state->uart_port != uport)
2647                 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2648                         state->uart_port, uport);
2650         mutex_lock(&port_mutex);
2652         /*
2653          * Mark the port "dead" - this prevents any opens from
2654          * succeeding while we shut down the port.
2655          */
2656         mutex_lock(&port->mutex);
2657         uport->flags |= UPF_DEAD;
2658         mutex_unlock(&port->mutex);
2660         /*
2661          * Remove the devices from the tty layer
2662          */
2663         tty_unregister_device(drv->tty_driver, uport->line);
2665         if (port->tty)
2666                 tty_vhangup(port->tty);
2668         /*
2669          * Free the port IO and memory resources, if any.
2670          */
2671         if (uport->type != PORT_UNKNOWN)
2672                 uport->ops->release_port(uport);
2674         /*
2675          * Indicate that there isn't a port here anymore.
2676          */
2677         uport->type = PORT_UNKNOWN;
2679         state->uart_port = NULL;
2680         mutex_unlock(&port_mutex);
2682         return 0;
2685 /*
2686  *      Are the two ports equivalent?
2687  */
2688 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2690         if (port1->iotype != port2->iotype)
2691                 return 0;
2693         switch (port1->iotype) {
2694         case UPIO_PORT:
2695                 return (port1->iobase == port2->iobase);
2696         case UPIO_HUB6:
2697                 return (port1->iobase == port2->iobase) &&
2698                        (port1->hub6   == port2->hub6);
2699         case UPIO_MEM:
2700         case UPIO_MEM32:
2701         case UPIO_AU:
2702         case UPIO_TSI:
2703                 return (port1->mapbase == port2->mapbase);
2704         }
2705         return 0;
2707 EXPORT_SYMBOL(uart_match_port);
2709 /**
2710  *      uart_handle_dcd_change - handle a change of carrier detect state
2711  *      @uport: uart_port structure for the open port
2712  *      @status: new carrier detect status, nonzero if active
2713  */
2714 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2716         struct uart_state *state = uport->state;
2717         struct tty_port *port = &state->port;
2718         struct tty_ldisc *ld = NULL;
2719         struct pps_event_time ts;
2720         struct tty_struct *tty = port->tty;
2722         if (tty)
2723                 ld = tty_ldisc_ref(tty);
2724         if (ld && ld->ops->dcd_change)
2725                 pps_get_ts(&ts);
2727         uport->icount.dcd++;
2728 #ifdef CONFIG_HARD_PPS
2729         if ((uport->flags & UPF_HARDPPS_CD) && status)
2730                 hardpps();
2731 #endif
2733         if (port->flags & ASYNC_CHECK_CD) {
2734                 if (status)
2735                         wake_up_interruptible(&port->open_wait);
2736                 else if (tty)
2737                         tty_hangup(tty);
2738         }
2740         if (ld && ld->ops->dcd_change)
2741                 ld->ops->dcd_change(tty, status, &ts);
2742         if (ld)
2743                 tty_ldisc_deref(ld);
2745 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2747 /**
2748  *      uart_handle_cts_change - handle a change of clear-to-send state
2749  *      @uport: uart_port structure for the open port
2750  *      @status: new clear to send status, nonzero if active
2751  */
2752 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2754         struct tty_port *port = &uport->state->port;
2755         struct tty_struct *tty = port->tty;
2757         uport->icount.cts++;
2759         if (tty_port_cts_enabled(port)) {
2760                 if (tty->hw_stopped) {
2761                         if (status) {
2762                                 tty->hw_stopped = 0;
2763                                 uport->ops->start_tx(uport);
2764                                 uart_write_wakeup(uport);
2765                         }
2766                 } else {
2767                         if (!status) {
2768                                 tty->hw_stopped = 1;
2769                                 uport->ops->stop_tx(uport);
2770                         }
2771                 }
2772         }
2774 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2776 /**
2777  * uart_insert_char - push a char to the uart layer
2778  *
2779  * User is responsible to call tty_flip_buffer_push when they are done with
2780  * insertion.
2781  *
2782  * @port: corresponding port
2783  * @status: state of the serial port RX buffer (LSR for 8250)
2784  * @overrun: mask of overrun bits in @status
2785  * @ch: character to push
2786  * @flag: flag for the character (see TTY_NORMAL and friends)
2787  */
2788 void uart_insert_char(struct uart_port *port, unsigned int status,
2789                  unsigned int overrun, unsigned int ch, unsigned int flag)
2791         struct tty_struct *tty = port->state->port.tty;
2793         if ((status & port->ignore_status_mask & ~overrun) == 0)
2794                 if (tty_insert_flip_char(tty, ch, flag) == 0)
2795                         ++port->icount.buf_overrun;
2797         /*
2798          * Overrun is special.  Since it's reported immediately,
2799          * it doesn't affect the current character.
2800          */
2801         if (status & ~port->ignore_status_mask & overrun)
2802                 if (tty_insert_flip_char(tty, 0, TTY_OVERRUN) == 0)
2803                         ++port->icount.buf_overrun;
2805 EXPORT_SYMBOL_GPL(uart_insert_char);
2807 EXPORT_SYMBOL(uart_write_wakeup);
2808 EXPORT_SYMBOL(uart_register_driver);
2809 EXPORT_SYMBOL(uart_unregister_driver);
2810 EXPORT_SYMBOL(uart_suspend_port);
2811 EXPORT_SYMBOL(uart_resume_port);
2812 EXPORT_SYMBOL(uart_add_one_port);
2813 EXPORT_SYMBOL(uart_remove_one_port);
2815 MODULE_DESCRIPTION("Serial driver core");
2816 MODULE_LICENSE("GPL");