aa2e85dc1e2251e29e32af6f06ca15bc55f7c902
[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 #ifdef CONFIG_SERIAL_CORE_CONSOLE
54 #define uart_console(port)      ((port)->cons && (port)->cons->index == (port)->line)
55 #else
56 #define uart_console(port)      (0)
57 #endif
59 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
60                                         struct ktermios *old_termios);
61 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
62 static void uart_change_pm(struct uart_state *state, int pm_state);
64 static void uart_port_shutdown(struct tty_port *port);
66 /*
67  * This routine is used by the interrupt handler to schedule processing in
68  * the software interrupt portion of the driver.
69  */
70 void uart_write_wakeup(struct uart_port *port)
71 {
72         struct uart_state *state = port->state;
73         /*
74          * This means you called this function _after_ the port was
75          * closed.  No cookie for you.
76          */
77         BUG_ON(!state);
78         tty_wakeup(state->port.tty);
79 }
81 static void uart_stop(struct tty_struct *tty)
82 {
83         struct uart_state *state = tty->driver_data;
84         struct uart_port *port = state->uart_port;
85         unsigned long flags;
87         spin_lock_irqsave(&port->lock, flags);
88         port->ops->stop_tx(port);
89         spin_unlock_irqrestore(&port->lock, flags);
90 }
92 static void __uart_start(struct tty_struct *tty)
93 {
94         struct uart_state *state = tty->driver_data;
95         struct uart_port *port = state->uart_port;
97         if (port->ops->wake_peer)
98                 port->ops->wake_peer(port);
100         if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
101             !tty->stopped && !tty->hw_stopped)
102                 port->ops->start_tx(port);
105 static void uart_start(struct tty_struct *tty)
107         struct uart_state *state = tty->driver_data;
108         struct uart_port *port = state->uart_port;
109         unsigned long flags;
111         spin_lock_irqsave(&port->lock, flags);
112         __uart_start(tty);
113         spin_unlock_irqrestore(&port->lock, flags);
116 static inline void
117 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
119         unsigned long flags;
120         unsigned int old;
122         spin_lock_irqsave(&port->lock, flags);
123         old = port->mctrl;
124         port->mctrl = (old & ~clear) | set;
125         if (old != port->mctrl)
126                 port->ops->set_mctrl(port, port->mctrl);
127         spin_unlock_irqrestore(&port->lock, flags);
130 #define uart_set_mctrl(port, set)       uart_update_mctrl(port, set, 0)
131 #define uart_clear_mctrl(port, clear)   uart_update_mctrl(port, 0, clear)
133 /*
134  * Startup the port.  This will be called once per open.  All calls
135  * will be serialised by the per-port mutex.
136  */
137 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
138                 int init_hw)
140         struct uart_port *uport = state->uart_port;
141         struct tty_port *port = &state->port;
142         unsigned long page;
143         int retval = 0;
145         if (uport->type == PORT_UNKNOWN)
146                 return 1;
148         /*
149          * Initialise and allocate the transmit and temporary
150          * buffer.
151          */
152         if (!state->xmit.buf) {
153                 /* This is protected by the per port mutex */
154                 page = get_zeroed_page(GFP_KERNEL);
155                 if (!page)
156                         return -ENOMEM;
158                 state->xmit.buf = (unsigned char *) page;
159                 uart_circ_clear(&state->xmit);
160         }
162         retval = uport->ops->startup(uport);
163         if (retval == 0) {
164                 if (uart_console(uport) && uport->cons->cflag) {
165                         tty->termios.c_cflag = uport->cons->cflag;
166                         uport->cons->cflag = 0;
167                 }
168                 /*
169                  * Initialise the hardware port settings.
170                  */
171                 uart_change_speed(tty, state, NULL);
173                 if (init_hw) {
174                         /*
175                          * Setup the RTS and DTR signals once the
176                          * port is open and ready to respond.
177                          */
178                         if (tty->termios.c_cflag & CBAUD)
179                                 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
180                 }
182                 if (tty_port_cts_enabled(port)) {
183                         spin_lock_irq(&uport->lock);
184                         if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
185                                 tty->hw_stopped = 1;
186                         spin_unlock_irq(&uport->lock);
187                 }
188         }
190         /*
191          * This is to allow setserial on this port. People may want to set
192          * port/irq/type and then reconfigure the port properly if it failed
193          * now.
194          */
195         if (retval && capable(CAP_SYS_ADMIN))
196                 return 1;
198         return retval;
201 static int uart_startup(struct tty_struct *tty, struct uart_state *state,
202                 int init_hw)
204         struct tty_port *port = &state->port;
205         int retval;
207         if (port->flags & ASYNC_INITIALIZED)
208                 return 0;
210         /*
211          * Set the TTY IO error marker - we will only clear this
212          * once we have successfully opened the port.
213          */
214         set_bit(TTY_IO_ERROR, &tty->flags);
216         retval = uart_port_startup(tty, state, init_hw);
217         if (!retval) {
218                 set_bit(ASYNCB_INITIALIZED, &port->flags);
219                 clear_bit(TTY_IO_ERROR, &tty->flags);
220         } else if (retval > 0)
221                 retval = 0;
223         return retval;
226 /*
227  * This routine will shutdown a serial port; interrupts are disabled, and
228  * DTR is dropped if the hangup on close termio flag is on.  Calls to
229  * uart_shutdown are serialised by the per-port semaphore.
230  */
231 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
233         struct uart_port *uport = state->uart_port;
234         struct tty_port *port = &state->port;
236         /*
237          * Set the TTY IO error marker
238          */
239         if (tty)
240                 set_bit(TTY_IO_ERROR, &tty->flags);
242         if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
243                 /*
244                  * Turn off DTR and RTS early.
245                  */
246                 if (!tty || (tty->termios.c_cflag & HUPCL))
247                         uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
249                 uart_port_shutdown(port);
250         }
252         /*
253          * It's possible for shutdown to be called after suspend if we get
254          * a DCD drop (hangup) at just the right time.  Clear suspended bit so
255          * we don't try to resume a port that has been shutdown.
256          */
257         clear_bit(ASYNCB_SUSPENDED, &port->flags);
259         /*
260          * Free the transmit buffer page.
261          */
262         if (state->xmit.buf) {
263                 free_page((unsigned long)state->xmit.buf);
264                 state->xmit.buf = NULL;
265         }
268 /**
269  *      uart_update_timeout - update per-port FIFO timeout.
270  *      @port:  uart_port structure describing the port
271  *      @cflag: termios cflag value
272  *      @baud:  speed of the port
273  *
274  *      Set the port FIFO timeout value.  The @cflag value should
275  *      reflect the actual hardware settings.
276  */
277 void
278 uart_update_timeout(struct uart_port *port, unsigned int cflag,
279                     unsigned int baud)
281         unsigned int bits;
283         /* byte size and parity */
284         switch (cflag & CSIZE) {
285         case CS5:
286                 bits = 7;
287                 break;
288         case CS6:
289                 bits = 8;
290                 break;
291         case CS7:
292                 bits = 9;
293                 break;
294         default:
295                 bits = 10;
296                 break; /* CS8 */
297         }
299         if (cflag & CSTOPB)
300                 bits++;
301         if (cflag & PARENB)
302                 bits++;
304         /*
305          * The total number of bits to be transmitted in the fifo.
306          */
307         bits = bits * port->fifosize;
309         /*
310          * Figure the timeout to send the above number of bits.
311          * Add .02 seconds of slop
312          */
313         port->timeout = (HZ * bits) / baud + HZ/50;
316 EXPORT_SYMBOL(uart_update_timeout);
318 /**
319  *      uart_get_baud_rate - return baud rate for a particular port
320  *      @port: uart_port structure describing the port in question.
321  *      @termios: desired termios settings.
322  *      @old: old termios (or NULL)
323  *      @min: minimum acceptable baud rate
324  *      @max: maximum acceptable baud rate
325  *
326  *      Decode the termios structure into a numeric baud rate,
327  *      taking account of the magic 38400 baud rate (with spd_*
328  *      flags), and mapping the %B0 rate to 9600 baud.
329  *
330  *      If the new baud rate is invalid, try the old termios setting.
331  *      If it's still invalid, we try 9600 baud.
332  *
333  *      Update the @termios structure to reflect the baud rate
334  *      we're actually going to be using. Don't do this for the case
335  *      where B0 is requested ("hang up").
336  */
337 unsigned int
338 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
339                    struct ktermios *old, unsigned int min, unsigned int max)
341         unsigned int try, baud, altbaud = 38400;
342         int hung_up = 0;
343         upf_t flags = port->flags & UPF_SPD_MASK;
345         if (flags == UPF_SPD_HI)
346                 altbaud = 57600;
347         else if (flags == UPF_SPD_VHI)
348                 altbaud = 115200;
349         else if (flags == UPF_SPD_SHI)
350                 altbaud = 230400;
351         else if (flags == UPF_SPD_WARP)
352                 altbaud = 460800;
354         for (try = 0; try < 2; try++) {
355                 baud = tty_termios_baud_rate(termios);
357                 /*
358                  * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
359                  * Die! Die! Die!
360                  */
361                 if (baud == 38400)
362                         baud = altbaud;
364                 /*
365                  * Special case: B0 rate.
366                  */
367                 if (baud == 0) {
368                         hung_up = 1;
369                         baud = 9600;
370                 }
372                 if (baud >= min && baud <= max)
373                         return baud;
375                 /*
376                  * Oops, the quotient was zero.  Try again with
377                  * the old baud rate if possible.
378                  */
379                 termios->c_cflag &= ~CBAUD;
380                 if (old) {
381                         baud = tty_termios_baud_rate(old);
382                         if (!hung_up)
383                                 tty_termios_encode_baud_rate(termios,
384                                                                 baud, baud);
385                         old = NULL;
386                         continue;
387                 }
389                 /*
390                  * As a last resort, if the range cannot be met then clip to
391                  * the nearest chip supported rate.
392                  */
393                 if (!hung_up) {
394                         if (baud <= min)
395                                 tty_termios_encode_baud_rate(termios,
396                                                         min + 1, min + 1);
397                         else
398                                 tty_termios_encode_baud_rate(termios,
399                                                         max - 1, max - 1);
400                 }
401         }
402         /* Should never happen */
403         WARN_ON(1);
404         return 0;
407 EXPORT_SYMBOL(uart_get_baud_rate);
409 /**
410  *      uart_get_divisor - return uart clock divisor
411  *      @port: uart_port structure describing the port.
412  *      @baud: desired baud rate
413  *
414  *      Calculate the uart clock divisor for the port.
415  */
416 unsigned int
417 uart_get_divisor(struct uart_port *port, unsigned int baud)
419         unsigned int quot;
421         /*
422          * Old custom speed handling.
423          */
424         if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
425                 quot = port->custom_divisor;
426         else
427                 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
429         return quot;
432 EXPORT_SYMBOL(uart_get_divisor);
434 /* FIXME: Consistent locking policy */
435 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
436                                         struct ktermios *old_termios)
438         struct tty_port *port = &state->port;
439         struct uart_port *uport = state->uart_port;
440         struct ktermios *termios;
442         /*
443          * If we have no tty, termios, or the port does not exist,
444          * then we can't set the parameters for this port.
445          */
446         if (!tty || uport->type == PORT_UNKNOWN)
447                 return;
449         termios = &tty->termios;
451         /*
452          * Set flags based on termios cflag
453          */
454         if (termios->c_cflag & CRTSCTS)
455                 set_bit(ASYNCB_CTS_FLOW, &port->flags);
456         else
457                 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
459         if (termios->c_cflag & CLOCAL)
460                 clear_bit(ASYNCB_CHECK_CD, &port->flags);
461         else
462                 set_bit(ASYNCB_CHECK_CD, &port->flags);
464         uport->ops->set_termios(uport, termios, old_termios);
467 static inline int __uart_put_char(struct uart_port *port,
468                                 struct circ_buf *circ, unsigned char c)
470         unsigned long flags;
471         int ret = 0;
473         if (!circ->buf)
474                 return 0;
476         spin_lock_irqsave(&port->lock, flags);
477         if (uart_circ_chars_free(circ) != 0) {
478                 circ->buf[circ->head] = c;
479                 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
480                 ret = 1;
481         }
482         spin_unlock_irqrestore(&port->lock, flags);
483         return ret;
486 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
488         struct uart_state *state = tty->driver_data;
490         return __uart_put_char(state->uart_port, &state->xmit, ch);
493 static void uart_flush_chars(struct tty_struct *tty)
495         uart_start(tty);
498 static int uart_write(struct tty_struct *tty,
499                                         const unsigned char *buf, int count)
501         struct uart_state *state = tty->driver_data;
502         struct uart_port *port;
503         struct circ_buf *circ;
504         unsigned long flags;
505         int c, ret = 0;
507         /*
508          * This means you called this function _after_ the port was
509          * closed.  No cookie for you.
510          */
511         if (!state) {
512                 WARN_ON(1);
513                 return -EL3HLT;
514         }
516         port = state->uart_port;
517         circ = &state->xmit;
519         if (!circ->buf)
520                 return 0;
522         spin_lock_irqsave(&port->lock, flags);
523         while (1) {
524                 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
525                 if (count < c)
526                         c = count;
527                 if (c <= 0)
528                         break;
529                 memcpy(circ->buf + circ->head, buf, c);
530                 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
531                 buf += c;
532                 count -= c;
533                 ret += c;
534         }
535         spin_unlock_irqrestore(&port->lock, flags);
537         uart_start(tty);
538         return ret;
541 static int uart_write_room(struct tty_struct *tty)
543         struct uart_state *state = tty->driver_data;
544         unsigned long flags;
545         int ret;
547         spin_lock_irqsave(&state->uart_port->lock, flags);
548         ret = uart_circ_chars_free(&state->xmit);
549         spin_unlock_irqrestore(&state->uart_port->lock, flags);
550         return ret;
553 static int uart_chars_in_buffer(struct tty_struct *tty)
555         struct uart_state *state = tty->driver_data;
556         unsigned long flags;
557         int ret;
559         spin_lock_irqsave(&state->uart_port->lock, flags);
560         ret = uart_circ_chars_pending(&state->xmit);
561         spin_unlock_irqrestore(&state->uart_port->lock, flags);
562         return ret;
565 static void uart_flush_buffer(struct tty_struct *tty)
567         struct uart_state *state = tty->driver_data;
568         struct uart_port *port;
569         unsigned long flags;
571         /*
572          * This means you called this function _after_ the port was
573          * closed.  No cookie for you.
574          */
575         if (!state) {
576                 WARN_ON(1);
577                 return;
578         }
580         port = state->uart_port;
581         pr_debug("uart_flush_buffer(%d) called\n", tty->index);
583         spin_lock_irqsave(&port->lock, flags);
584         uart_circ_clear(&state->xmit);
585         if (port->ops->flush_buffer)
586                 port->ops->flush_buffer(port);
587         spin_unlock_irqrestore(&port->lock, flags);
588         tty_wakeup(tty);
591 /*
592  * This function is used to send a high-priority XON/XOFF character to
593  * the device
594  */
595 static void uart_send_xchar(struct tty_struct *tty, char ch)
597         struct uart_state *state = tty->driver_data;
598         struct uart_port *port = state->uart_port;
599         unsigned long flags;
601         if (port->ops->send_xchar)
602                 port->ops->send_xchar(port, ch);
603         else {
604                 port->x_char = ch;
605                 if (ch) {
606                         spin_lock_irqsave(&port->lock, flags);
607                         port->ops->start_tx(port);
608                         spin_unlock_irqrestore(&port->lock, flags);
609                 }
610         }
613 static void uart_throttle(struct tty_struct *tty)
615         struct uart_state *state = tty->driver_data;
616         struct uart_port *port = state->uart_port;
617         uint32_t mask = 0;
619         if (I_IXOFF(tty))
620                 mask |= UPF_SOFT_FLOW;
621         if (tty->termios.c_cflag & CRTSCTS)
622                 mask |= UPF_HARD_FLOW;
624         if (port->flags & mask) {
625                 port->ops->throttle(port);
626                 mask &= ~port->flags;
627         }
629         if (mask & UPF_SOFT_FLOW)
630                 uart_send_xchar(tty, STOP_CHAR(tty));
632         if (mask & UPF_HARD_FLOW)
633                 uart_clear_mctrl(port, TIOCM_RTS);
636 static void uart_unthrottle(struct tty_struct *tty)
638         struct uart_state *state = tty->driver_data;
639         struct uart_port *port = state->uart_port;
640         uint32_t mask = 0;
642         if (I_IXOFF(tty))
643                 mask |= UPF_SOFT_FLOW;
644         if (tty->termios.c_cflag & CRTSCTS)
645                 mask |= UPF_HARD_FLOW;
647         if (port->flags & mask) {
648                 port->ops->unthrottle(port);
649                 mask &= ~port->flags;
650         }
652         if (mask & UPF_SOFT_FLOW) {
653                 if (port->x_char)
654                         port->x_char = 0;
655                 else
656                         uart_send_xchar(tty, START_CHAR(tty));
657         }
659         if (mask & UPF_HARD_FLOW)
660                 uart_set_mctrl(port, TIOCM_RTS);
663 static void do_uart_get_info(struct tty_port *port,
664                         struct serial_struct *retinfo)
666         struct uart_state *state = container_of(port, struct uart_state, port);
667         struct uart_port *uport = state->uart_port;
669         memset(retinfo, 0, sizeof(*retinfo));
671         retinfo->type       = uport->type;
672         retinfo->line       = uport->line;
673         retinfo->port       = uport->iobase;
674         if (HIGH_BITS_OFFSET)
675                 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
676         retinfo->irq                = uport->irq;
677         retinfo->flags      = uport->flags;
678         retinfo->xmit_fifo_size  = uport->fifosize;
679         retinfo->baud_base          = uport->uartclk / 16;
680         retinfo->close_delay        = jiffies_to_msecs(port->close_delay) / 10;
681         retinfo->closing_wait    = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
682                                 ASYNC_CLOSING_WAIT_NONE :
683                                 jiffies_to_msecs(port->closing_wait) / 10;
684         retinfo->custom_divisor  = uport->custom_divisor;
685         retinfo->hub6       = uport->hub6;
686         retinfo->io_type         = uport->iotype;
687         retinfo->iomem_reg_shift = uport->regshift;
688         retinfo->iomem_base      = (void *)(unsigned long)uport->mapbase;
691 static void uart_get_info(struct tty_port *port,
692                         struct serial_struct *retinfo)
694         /* Ensure the state we copy is consistent and no hardware changes
695            occur as we go */
696         mutex_lock(&port->mutex);
697         do_uart_get_info(port, retinfo);
698         mutex_unlock(&port->mutex);
701 static int uart_get_info_user(struct tty_port *port,
702                          struct serial_struct __user *retinfo)
704         struct serial_struct tmp;
705         uart_get_info(port, &tmp);
707         if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
708                 return -EFAULT;
709         return 0;
712 static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
713                          struct uart_state *state,
714                          struct serial_struct *new_info)
716         struct uart_port *uport = state->uart_port;
717         unsigned long new_port;
718         unsigned int change_irq, change_port, closing_wait;
719         unsigned int old_custom_divisor, close_delay;
720         upf_t old_flags, new_flags;
721         int retval = 0;
723         new_port = new_info->port;
724         if (HIGH_BITS_OFFSET)
725                 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
727         new_info->irq = irq_canonicalize(new_info->irq);
728         close_delay = msecs_to_jiffies(new_info->close_delay * 10);
729         closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
730                         ASYNC_CLOSING_WAIT_NONE :
731                         msecs_to_jiffies(new_info->closing_wait * 10);
734         change_irq  = !(uport->flags & UPF_FIXED_PORT)
735                 && new_info->irq != uport->irq;
737         /*
738          * Since changing the 'type' of the port changes its resource
739          * allocations, we should treat type changes the same as
740          * IO port changes.
741          */
742         change_port = !(uport->flags & UPF_FIXED_PORT)
743                 && (new_port != uport->iobase ||
744                     (unsigned long)new_info->iomem_base != uport->mapbase ||
745                     new_info->hub6 != uport->hub6 ||
746                     new_info->io_type != uport->iotype ||
747                     new_info->iomem_reg_shift != uport->regshift ||
748                     new_info->type != uport->type);
750         old_flags = uport->flags;
751         new_flags = new_info->flags;
752         old_custom_divisor = uport->custom_divisor;
754         if (!capable(CAP_SYS_ADMIN)) {
755                 retval = -EPERM;
756                 if (change_irq || change_port ||
757                     (new_info->baud_base != uport->uartclk / 16) ||
758                     (close_delay != port->close_delay) ||
759                     (closing_wait != port->closing_wait) ||
760                     (new_info->xmit_fifo_size &&
761                      new_info->xmit_fifo_size != uport->fifosize) ||
762                     (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
763                         goto exit;
764                 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
765                                (new_flags & UPF_USR_MASK));
766                 uport->custom_divisor = new_info->custom_divisor;
767                 goto check_and_exit;
768         }
770         /*
771          * Ask the low level driver to verify the settings.
772          */
773         if (uport->ops->verify_port)
774                 retval = uport->ops->verify_port(uport, new_info);
776         if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
777             (new_info->baud_base < 9600))
778                 retval = -EINVAL;
780         if (retval)
781                 goto exit;
783         if (change_port || change_irq) {
784                 retval = -EBUSY;
786                 /*
787                  * Make sure that we are the sole user of this port.
788                  */
789                 if (tty_port_users(port) > 1)
790                         goto exit;
792                 /*
793                  * We need to shutdown the serial port at the old
794                  * port/type/irq combination.
795                  */
796                 uart_shutdown(tty, state);
797         }
799         if (change_port) {
800                 unsigned long old_iobase, old_mapbase;
801                 unsigned int old_type, old_iotype, old_hub6, old_shift;
803                 old_iobase = uport->iobase;
804                 old_mapbase = uport->mapbase;
805                 old_type = uport->type;
806                 old_hub6 = uport->hub6;
807                 old_iotype = uport->iotype;
808                 old_shift = uport->regshift;
810                 /*
811                  * Free and release old regions
812                  */
813                 if (old_type != PORT_UNKNOWN)
814                         uport->ops->release_port(uport);
816                 uport->iobase = new_port;
817                 uport->type = new_info->type;
818                 uport->hub6 = new_info->hub6;
819                 uport->iotype = new_info->io_type;
820                 uport->regshift = new_info->iomem_reg_shift;
821                 uport->mapbase = (unsigned long)new_info->iomem_base;
823                 /*
824                  * Claim and map the new regions
825                  */
826                 if (uport->type != PORT_UNKNOWN) {
827                         retval = uport->ops->request_port(uport);
828                 } else {
829                         /* Always success - Jean II */
830                         retval = 0;
831                 }
833                 /*
834                  * If we fail to request resources for the
835                  * new port, try to restore the old settings.
836                  */
837                 if (retval && old_type != PORT_UNKNOWN) {
838                         uport->iobase = old_iobase;
839                         uport->type = old_type;
840                         uport->hub6 = old_hub6;
841                         uport->iotype = old_iotype;
842                         uport->regshift = old_shift;
843                         uport->mapbase = old_mapbase;
844                         retval = uport->ops->request_port(uport);
845                         /*
846                          * If we failed to restore the old settings,
847                          * we fail like this.
848                          */
849                         if (retval)
850                                 uport->type = PORT_UNKNOWN;
852                         /*
853                          * We failed anyway.
854                          */
855                         retval = -EBUSY;
856                         /* Added to return the correct error -Ram Gupta */
857                         goto exit;
858                 }
859         }
861         if (change_irq)
862                 uport->irq      = new_info->irq;
863         if (!(uport->flags & UPF_FIXED_PORT))
864                 uport->uartclk  = new_info->baud_base * 16;
865         uport->flags            = (uport->flags & ~UPF_CHANGE_MASK) |
866                                  (new_flags & UPF_CHANGE_MASK);
867         uport->custom_divisor   = new_info->custom_divisor;
868         port->close_delay     = close_delay;
869         port->closing_wait    = closing_wait;
870         if (new_info->xmit_fifo_size)
871                 uport->fifosize = new_info->xmit_fifo_size;
872         if (port->tty)
873                 port->tty->low_latency =
874                         (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
876  check_and_exit:
877         retval = 0;
878         if (uport->type == PORT_UNKNOWN)
879                 goto exit;
880         if (port->flags & ASYNC_INITIALIZED) {
881                 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
882                     old_custom_divisor != uport->custom_divisor) {
883                         /*
884                          * If they're setting up a custom divisor or speed,
885                          * instead of clearing it, then bitch about it. No
886                          * need to rate-limit; it's CAP_SYS_ADMIN only.
887                          */
888                         if (uport->flags & UPF_SPD_MASK) {
889                                 char buf[64];
890                                 printk(KERN_NOTICE
891                                        "%s sets custom speed on %s. This "
892                                        "is deprecated.\n", current->comm,
893                                        tty_name(port->tty, buf));
894                         }
895                         uart_change_speed(tty, state, NULL);
896                 }
897         } else
898                 retval = uart_startup(tty, state, 1);
899  exit:
900         return retval;
903 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
904                          struct serial_struct __user *newinfo)
906         struct serial_struct new_serial;
907         struct tty_port *port = &state->port;
908         int retval;
910         if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
911                 return -EFAULT;
913         /*
914          * This semaphore protects port->count.  It is also
915          * very useful to prevent opens.  Also, take the
916          * port configuration semaphore to make sure that a
917          * module insertion/removal doesn't change anything
918          * under us.
919          */
920         mutex_lock(&port->mutex);
921         retval = uart_set_info(tty, port, state, &new_serial);
922         mutex_unlock(&port->mutex);
923         return retval;
926 /**
927  *      uart_get_lsr_info       -       get line status register info
928  *      @tty: tty associated with the UART
929  *      @state: UART being queried
930  *      @value: returned modem value
931  *
932  *      Note: uart_ioctl protects us against hangups.
933  */
934 static int uart_get_lsr_info(struct tty_struct *tty,
935                         struct uart_state *state, unsigned int __user *value)
937         struct uart_port *uport = state->uart_port;
938         unsigned int result;
940         result = uport->ops->tx_empty(uport);
942         /*
943          * If we're about to load something into the transmit
944          * register, we'll pretend the transmitter isn't empty to
945          * avoid a race condition (depending on when the transmit
946          * interrupt happens).
947          */
948         if (uport->x_char ||
949             ((uart_circ_chars_pending(&state->xmit) > 0) &&
950              !tty->stopped && !tty->hw_stopped))
951                 result &= ~TIOCSER_TEMT;
953         return put_user(result, value);
956 static int uart_tiocmget(struct tty_struct *tty)
958         struct uart_state *state = tty->driver_data;
959         struct tty_port *port = &state->port;
960         struct uart_port *uport = state->uart_port;
961         int result = -EIO;
963         mutex_lock(&port->mutex);
964         if (!(tty->flags & (1 << TTY_IO_ERROR))) {
965                 result = uport->mctrl;
966                 spin_lock_irq(&uport->lock);
967                 result |= uport->ops->get_mctrl(uport);
968                 spin_unlock_irq(&uport->lock);
969         }
970         mutex_unlock(&port->mutex);
972         return result;
975 static int
976 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
978         struct uart_state *state = tty->driver_data;
979         struct uart_port *uport = state->uart_port;
980         struct tty_port *port = &state->port;
981         int ret = -EIO;
983         mutex_lock(&port->mutex);
984         if (!(tty->flags & (1 << TTY_IO_ERROR))) {
985                 uart_update_mctrl(uport, set, clear);
986                 ret = 0;
987         }
988         mutex_unlock(&port->mutex);
989         return ret;
992 static int uart_break_ctl(struct tty_struct *tty, int break_state)
994         struct uart_state *state = tty->driver_data;
995         struct tty_port *port = &state->port;
996         struct uart_port *uport = state->uart_port;
998         mutex_lock(&port->mutex);
1000         if (uport->type != PORT_UNKNOWN)
1001                 uport->ops->break_ctl(uport, break_state);
1003         mutex_unlock(&port->mutex);
1004         return 0;
1007 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1009         struct uart_port *uport = state->uart_port;
1010         struct tty_port *port = &state->port;
1011         int flags, ret;
1013         if (!capable(CAP_SYS_ADMIN))
1014                 return -EPERM;
1016         /*
1017          * Take the per-port semaphore.  This prevents count from
1018          * changing, and hence any extra opens of the port while
1019          * we're auto-configuring.
1020          */
1021         if (mutex_lock_interruptible(&port->mutex))
1022                 return -ERESTARTSYS;
1024         ret = -EBUSY;
1025         if (tty_port_users(port) == 1) {
1026                 uart_shutdown(tty, state);
1028                 /*
1029                  * If we already have a port type configured,
1030                  * we must release its resources.
1031                  */
1032                 if (uport->type != PORT_UNKNOWN)
1033                         uport->ops->release_port(uport);
1035                 flags = UART_CONFIG_TYPE;
1036                 if (uport->flags & UPF_AUTO_IRQ)
1037                         flags |= UART_CONFIG_IRQ;
1039                 /*
1040                  * This will claim the ports resources if
1041                  * a port is found.
1042                  */
1043                 uport->ops->config_port(uport, flags);
1045                 ret = uart_startup(tty, state, 1);
1046         }
1047         mutex_unlock(&port->mutex);
1048         return ret;
1051 /*
1052  * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1053  * - mask passed in arg for lines of interest
1054  *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1055  * Caller should use TIOCGICOUNT to see which one it was
1056  *
1057  * FIXME: This wants extracting into a common all driver implementation
1058  * of TIOCMWAIT using tty_port.
1059  */
1060 static int
1061 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1063         struct uart_port *uport = state->uart_port;
1064         struct tty_port *port = &state->port;
1065         DECLARE_WAITQUEUE(wait, current);
1066         struct uart_icount cprev, cnow;
1067         int ret;
1069         /*
1070          * note the counters on entry
1071          */
1072         spin_lock_irq(&uport->lock);
1073         memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1075         /*
1076          * Force modem status interrupts on
1077          */
1078         uport->ops->enable_ms(uport);
1079         spin_unlock_irq(&uport->lock);
1081         add_wait_queue(&port->delta_msr_wait, &wait);
1082         for (;;) {
1083                 spin_lock_irq(&uport->lock);
1084                 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1085                 spin_unlock_irq(&uport->lock);
1087                 set_current_state(TASK_INTERRUPTIBLE);
1089                 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1090                     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1091                     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1092                     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1093                         ret = 0;
1094                         break;
1095                 }
1097                 schedule();
1099                 /* see if a signal did it */
1100                 if (signal_pending(current)) {
1101                         ret = -ERESTARTSYS;
1102                         break;
1103                 }
1105                 cprev = cnow;
1106         }
1108         current->state = TASK_RUNNING;
1109         remove_wait_queue(&port->delta_msr_wait, &wait);
1111         return ret;
1114 /*
1115  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1116  * Return: write counters to the user passed counter struct
1117  * NB: both 1->0 and 0->1 transitions are counted except for
1118  *     RI where only 0->1 is counted.
1119  */
1120 static int uart_get_icount(struct tty_struct *tty,
1121                           struct serial_icounter_struct *icount)
1123         struct uart_state *state = tty->driver_data;
1124         struct uart_icount cnow;
1125         struct uart_port *uport = state->uart_port;
1127         spin_lock_irq(&uport->lock);
1128         memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1129         spin_unlock_irq(&uport->lock);
1131         icount->cts         = cnow.cts;
1132         icount->dsr         = cnow.dsr;
1133         icount->rng         = cnow.rng;
1134         icount->dcd         = cnow.dcd;
1135         icount->rx          = cnow.rx;
1136         icount->tx          = cnow.tx;
1137         icount->frame       = cnow.frame;
1138         icount->overrun     = cnow.overrun;
1139         icount->parity      = cnow.parity;
1140         icount->brk         = cnow.brk;
1141         icount->buf_overrun = cnow.buf_overrun;
1143         return 0;
1146 /*
1147  * Called via sys_ioctl.  We can use spin_lock_irq() here.
1148  */
1149 static int
1150 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1151            unsigned long arg)
1153         struct uart_state *state = tty->driver_data;
1154         struct tty_port *port = &state->port;
1155         void __user *uarg = (void __user *)arg;
1156         int ret = -ENOIOCTLCMD;
1159         /*
1160          * These ioctls don't rely on the hardware to be present.
1161          */
1162         switch (cmd) {
1163         case TIOCGSERIAL:
1164                 ret = uart_get_info_user(port, uarg);
1165                 break;
1167         case TIOCSSERIAL:
1168                 ret = uart_set_info_user(tty, state, uarg);
1169                 break;
1171         case TIOCSERCONFIG:
1172                 ret = uart_do_autoconfig(tty, state);
1173                 break;
1175         case TIOCSERGWILD: /* obsolete */
1176         case TIOCSERSWILD: /* obsolete */
1177                 ret = 0;
1178                 break;
1179         }
1181         if (ret != -ENOIOCTLCMD)
1182                 goto out;
1184         if (tty->flags & (1 << TTY_IO_ERROR)) {
1185                 ret = -EIO;
1186                 goto out;
1187         }
1189         /*
1190          * The following should only be used when hardware is present.
1191          */
1192         switch (cmd) {
1193         case TIOCMIWAIT:
1194                 ret = uart_wait_modem_status(state, arg);
1195                 break;
1196         }
1198         if (ret != -ENOIOCTLCMD)
1199                 goto out;
1201         mutex_lock(&port->mutex);
1203         if (tty->flags & (1 << TTY_IO_ERROR)) {
1204                 ret = -EIO;
1205                 goto out_up;
1206         }
1208         /*
1209          * All these rely on hardware being present and need to be
1210          * protected against the tty being hung up.
1211          */
1212         switch (cmd) {
1213         case TIOCSERGETLSR: /* Get line status register */
1214                 ret = uart_get_lsr_info(tty, state, uarg);
1215                 break;
1217         default: {
1218                 struct uart_port *uport = state->uart_port;
1219                 if (uport->ops->ioctl)
1220                         ret = uport->ops->ioctl(uport, cmd, arg);
1221                 break;
1222         }
1223         }
1224 out_up:
1225         mutex_unlock(&port->mutex);
1226 out:
1227         return ret;
1230 static void uart_set_ldisc(struct tty_struct *tty)
1232         struct uart_state *state = tty->driver_data;
1233         struct uart_port *uport = state->uart_port;
1235         if (uport->ops->set_ldisc)
1236                 uport->ops->set_ldisc(uport, tty->termios.c_line);
1239 static void uart_set_termios(struct tty_struct *tty,
1240                                                 struct ktermios *old_termios)
1242         struct uart_state *state = tty->driver_data;
1243         struct uart_port *uport = state->uart_port;
1244         unsigned long flags;
1245         unsigned int cflag = tty->termios.c_cflag;
1246         unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1247         bool sw_changed = false;
1249         /*
1250          * Drivers doing software flow control also need to know
1251          * about changes to these input settings.
1252          */
1253         if (uport->flags & UPF_SOFT_FLOW) {
1254                 iflag_mask |= IXANY|IXON|IXOFF;
1255                 sw_changed =
1256                    tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1257                    tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1258         }
1260         /*
1261          * These are the bits that are used to setup various
1262          * flags in the low level driver. We can ignore the Bfoo
1263          * bits in c_cflag; c_[io]speed will always be set
1264          * appropriately by set_termios() in tty_ioctl.c
1265          */
1266         if ((cflag ^ old_termios->c_cflag) == 0 &&
1267             tty->termios.c_ospeed == old_termios->c_ospeed &&
1268             tty->termios.c_ispeed == old_termios->c_ispeed &&
1269             ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1270             !sw_changed) {
1271                 return;
1272         }
1274         uart_change_speed(tty, state, old_termios);
1276         /* Handle transition to B0 status */
1277         if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1278                 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1279         /* Handle transition away from B0 status */
1280         else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1281                 unsigned int mask = TIOCM_DTR;
1282                 if (!(cflag & CRTSCTS) ||
1283                     !test_bit(TTY_THROTTLED, &tty->flags))
1284                         mask |= TIOCM_RTS;
1285                 uart_set_mctrl(uport, mask);
1286         }
1288         /*
1289          * If the port is doing h/w assisted flow control, do nothing.
1290          * We assume that tty->hw_stopped has never been set.
1291          */
1292         if (uport->flags & UPF_HARD_FLOW)
1293                 return;
1295         /* Handle turning off CRTSCTS */
1296         if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1297                 spin_lock_irqsave(&uport->lock, flags);
1298                 tty->hw_stopped = 0;
1299                 __uart_start(tty);
1300                 spin_unlock_irqrestore(&uport->lock, flags);
1301         }
1302         /* Handle turning on CRTSCTS */
1303         else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1304                 spin_lock_irqsave(&uport->lock, flags);
1305                 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
1306                         tty->hw_stopped = 1;
1307                         uport->ops->stop_tx(uport);
1308                 }
1309                 spin_unlock_irqrestore(&uport->lock, flags);
1310         }
1313 /*
1314  * In 2.4.5, calls to this will be serialized via the BKL in
1315  *  linux/drivers/char/tty_io.c:tty_release()
1316  *  linux/drivers/char/tty_io.c:do_tty_handup()
1317  */
1318 static void uart_close(struct tty_struct *tty, struct file *filp)
1320         struct uart_state *state = tty->driver_data;
1321         struct tty_port *port;
1322         struct uart_port *uport;
1323         unsigned long flags;
1325         if (!state)
1326                 return;
1328         uport = state->uart_port;
1329         port = &state->port;
1331         pr_debug("uart_close(%d) called\n", uport->line);
1333         if (tty_port_close_start(port, tty, filp) == 0)
1334                 return;
1336         /*
1337          * At this point, we stop accepting input.  To do this, we
1338          * disable the receive line status interrupts.
1339          */
1340         if (port->flags & ASYNC_INITIALIZED) {
1341                 unsigned long flags;
1342                 spin_lock_irqsave(&uport->lock, flags);
1343                 uport->ops->stop_rx(uport);
1344                 spin_unlock_irqrestore(&uport->lock, flags);
1345                 /*
1346                  * Before we drop DTR, make sure the UART transmitter
1347                  * has completely drained; this is especially
1348                  * important if there is a transmit FIFO!
1349                  */
1350                 uart_wait_until_sent(tty, uport->timeout);
1351         }
1353         mutex_lock(&port->mutex);
1354         uart_shutdown(tty, state);
1355         uart_flush_buffer(tty);
1357         tty_ldisc_flush(tty);
1359         tty_port_tty_set(port, NULL);
1360         spin_lock_irqsave(&port->lock, flags);
1361         tty->closing = 0;
1363         if (port->blocked_open) {
1364                 spin_unlock_irqrestore(&port->lock, flags);
1365                 if (port->close_delay)
1366                         msleep_interruptible(
1367                                         jiffies_to_msecs(port->close_delay));
1368                 spin_lock_irqsave(&port->lock, flags);
1369         } else if (!uart_console(uport)) {
1370                 spin_unlock_irqrestore(&port->lock, flags);
1371                 uart_change_pm(state, 3);
1372                 spin_lock_irqsave(&port->lock, flags);
1373         }
1375         /*
1376          * Wake up anyone trying to open this port.
1377          */
1378         clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1379         clear_bit(ASYNCB_CLOSING, &port->flags);
1380         spin_unlock_irqrestore(&port->lock, flags);
1381         wake_up_interruptible(&port->open_wait);
1382         wake_up_interruptible(&port->close_wait);
1384         mutex_unlock(&port->mutex);
1387 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1389         struct uart_state *state = tty->driver_data;
1390         struct uart_port *port = state->uart_port;
1391         unsigned long char_time, expire;
1393         if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1394                 return;
1396         /*
1397          * Set the check interval to be 1/5 of the estimated time to
1398          * send a single character, and make it at least 1.  The check
1399          * interval should also be less than the timeout.
1400          *
1401          * Note: we have to use pretty tight timings here to satisfy
1402          * the NIST-PCTS.
1403          */
1404         char_time = (port->timeout - HZ/50) / port->fifosize;
1405         char_time = char_time / 5;
1406         if (char_time == 0)
1407                 char_time = 1;
1408         if (timeout && timeout < char_time)
1409                 char_time = timeout;
1411         /*
1412          * If the transmitter hasn't cleared in twice the approximate
1413          * amount of time to send the entire FIFO, it probably won't
1414          * ever clear.  This assumes the UART isn't doing flow
1415          * control, which is currently the case.  Hence, if it ever
1416          * takes longer than port->timeout, this is probably due to a
1417          * UART bug of some kind.  So, we clamp the timeout parameter at
1418          * 2*port->timeout.
1419          */
1420         if (timeout == 0 || timeout > 2 * port->timeout)
1421                 timeout = 2 * port->timeout;
1423         expire = jiffies + timeout;
1425         pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1426                 port->line, jiffies, expire);
1428         /*
1429          * Check whether the transmitter is empty every 'char_time'.
1430          * 'timeout' / 'expire' give us the maximum amount of time
1431          * we wait.
1432          */
1433         while (!port->ops->tx_empty(port)) {
1434                 msleep_interruptible(jiffies_to_msecs(char_time));
1435                 if (signal_pending(current))
1436                         break;
1437                 if (time_after(jiffies, expire))
1438                         break;
1439         }
1442 /*
1443  * This is called with the BKL held in
1444  *  linux/drivers/char/tty_io.c:do_tty_hangup()
1445  * We're called from the eventd thread, so we can sleep for
1446  * a _short_ time only.
1447  */
1448 static void uart_hangup(struct tty_struct *tty)
1450         struct uart_state *state = tty->driver_data;
1451         struct tty_port *port = &state->port;
1452         unsigned long flags;
1454         pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1456         mutex_lock(&port->mutex);
1457         if (port->flags & ASYNC_NORMAL_ACTIVE) {
1458                 uart_flush_buffer(tty);
1459                 uart_shutdown(tty, state);
1460                 spin_lock_irqsave(&port->lock, flags);
1461                 port->count = 0;
1462                 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1463                 spin_unlock_irqrestore(&port->lock, flags);
1464                 tty_port_tty_set(port, NULL);
1465                 wake_up_interruptible(&port->open_wait);
1466                 wake_up_interruptible(&port->delta_msr_wait);
1467         }
1468         mutex_unlock(&port->mutex);
1471 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1473         return 0;
1476 static void uart_port_shutdown(struct tty_port *port)
1478         struct uart_state *state = container_of(port, struct uart_state, port);
1479         struct uart_port *uport = state->uart_port;
1481         /*
1482          * clear delta_msr_wait queue to avoid mem leaks: we may free
1483          * the irq here so the queue might never be woken up.  Note
1484          * that we won't end up waiting on delta_msr_wait again since
1485          * any outstanding file descriptors should be pointing at
1486          * hung_up_tty_fops now.
1487          */
1488         wake_up_interruptible(&port->delta_msr_wait);
1490         /*
1491          * Free the IRQ and disable the port.
1492          */
1493         uport->ops->shutdown(uport);
1495         /*
1496          * Ensure that the IRQ handler isn't running on another CPU.
1497          */
1498         synchronize_irq(uport->irq);
1501 static int uart_carrier_raised(struct tty_port *port)
1503         struct uart_state *state = container_of(port, struct uart_state, port);
1504         struct uart_port *uport = state->uart_port;
1505         int mctrl;
1506         spin_lock_irq(&uport->lock);
1507         uport->ops->enable_ms(uport);
1508         mctrl = uport->ops->get_mctrl(uport);
1509         spin_unlock_irq(&uport->lock);
1510         if (mctrl & TIOCM_CAR)
1511                 return 1;
1512         return 0;
1515 static void uart_dtr_rts(struct tty_port *port, int onoff)
1517         struct uart_state *state = container_of(port, struct uart_state, port);
1518         struct uart_port *uport = state->uart_port;
1520         if (onoff)
1521                 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1522         else
1523                 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1526 /*
1527  * calls to uart_open are serialised by the BKL in
1528  *   fs/char_dev.c:chrdev_open()
1529  * Note that if this fails, then uart_close() _will_ be called.
1530  *
1531  * In time, we want to scrap the "opening nonpresent ports"
1532  * behaviour and implement an alternative way for setserial
1533  * to set base addresses/ports/types.  This will allow us to
1534  * get rid of a certain amount of extra tests.
1535  */
1536 static int uart_open(struct tty_struct *tty, struct file *filp)
1538         struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1539         int retval, line = tty->index;
1540         struct uart_state *state = drv->state + line;
1541         struct tty_port *port = &state->port;
1543         pr_debug("uart_open(%d) called\n", line);
1545         /*
1546          * We take the semaphore here to guarantee that we won't be re-entered
1547          * while allocating the state structure, or while we request any IRQs
1548          * that the driver may need.  This also has the nice side-effect that
1549          * it delays the action of uart_hangup, so we can guarantee that
1550          * state->port.tty will always contain something reasonable.
1551          */
1552         if (mutex_lock_interruptible(&port->mutex)) {
1553                 retval = -ERESTARTSYS;
1554                 goto end;
1555         }
1557         port->count++;
1558         if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1559                 retval = -ENXIO;
1560                 goto err_dec_count;
1561         }
1563         /*
1564          * Once we set tty->driver_data here, we are guaranteed that
1565          * uart_close() will decrement the driver module use count.
1566          * Any failures from here onwards should not touch the count.
1567          */
1568         tty->driver_data = state;
1569         state->uart_port->state = state;
1570         tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1571         tty_port_tty_set(port, tty);
1573         /*
1574          * If the port is in the middle of closing, bail out now.
1575          */
1576         if (tty_hung_up_p(filp)) {
1577                 retval = -EAGAIN;
1578                 goto err_dec_count;
1579         }
1581         /*
1582          * Make sure the device is in D0 state.
1583          */
1584         if (port->count == 1)
1585                 uart_change_pm(state, 0);
1587         /*
1588          * Start up the serial port.
1589          */
1590         retval = uart_startup(tty, state, 0);
1592         /*
1593          * If we succeeded, wait until the port is ready.
1594          */
1595         mutex_unlock(&port->mutex);
1596         if (retval == 0)
1597                 retval = tty_port_block_til_ready(port, tty, filp);
1599 end:
1600         return retval;
1601 err_dec_count:
1602         port->count--;
1603         mutex_unlock(&port->mutex);
1604         goto end;
1607 static const char *uart_type(struct uart_port *port)
1609         const char *str = NULL;
1611         if (port->ops->type)
1612                 str = port->ops->type(port);
1614         if (!str)
1615                 str = "unknown";
1617         return str;
1620 #ifdef CONFIG_PROC_FS
1622 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1624         struct uart_state *state = drv->state + i;
1625         struct tty_port *port = &state->port;
1626         int pm_state;
1627         struct uart_port *uport = state->uart_port;
1628         char stat_buf[32];
1629         unsigned int status;
1630         int mmio;
1632         if (!uport)
1633                 return;
1635         mmio = uport->iotype >= UPIO_MEM;
1636         seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1637                         uport->line, uart_type(uport),
1638                         mmio ? "mmio:0x" : "port:",
1639                         mmio ? (unsigned long long)uport->mapbase
1640                              : (unsigned long long)uport->iobase,
1641                         uport->irq);
1643         if (uport->type == PORT_UNKNOWN) {
1644                 seq_putc(m, '\n');
1645                 return;
1646         }
1648         if (capable(CAP_SYS_ADMIN)) {
1649                 mutex_lock(&port->mutex);
1650                 pm_state = state->pm_state;
1651                 if (pm_state)
1652                         uart_change_pm(state, 0);
1653                 spin_lock_irq(&uport->lock);
1654                 status = uport->ops->get_mctrl(uport);
1655                 spin_unlock_irq(&uport->lock);
1656                 if (pm_state)
1657                         uart_change_pm(state, pm_state);
1658                 mutex_unlock(&port->mutex);
1660                 seq_printf(m, " tx:%d rx:%d",
1661                                 uport->icount.tx, uport->icount.rx);
1662                 if (uport->icount.frame)
1663                         seq_printf(m, " fe:%d",
1664                                 uport->icount.frame);
1665                 if (uport->icount.parity)
1666                         seq_printf(m, " pe:%d",
1667                                 uport->icount.parity);
1668                 if (uport->icount.brk)
1669                         seq_printf(m, " brk:%d",
1670                                 uport->icount.brk);
1671                 if (uport->icount.overrun)
1672                         seq_printf(m, " oe:%d",
1673                                 uport->icount.overrun);
1675 #define INFOBIT(bit, str) \
1676         if (uport->mctrl & (bit)) \
1677                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1678                         strlen(stat_buf) - 2)
1679 #define STATBIT(bit, str) \
1680         if (status & (bit)) \
1681                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1682                        strlen(stat_buf) - 2)
1684                 stat_buf[0] = '\0';
1685                 stat_buf[1] = '\0';
1686                 INFOBIT(TIOCM_RTS, "|RTS");
1687                 STATBIT(TIOCM_CTS, "|CTS");
1688                 INFOBIT(TIOCM_DTR, "|DTR");
1689                 STATBIT(TIOCM_DSR, "|DSR");
1690                 STATBIT(TIOCM_CAR, "|CD");
1691                 STATBIT(TIOCM_RNG, "|RI");
1692                 if (stat_buf[0])
1693                         stat_buf[0] = ' ';
1695                 seq_puts(m, stat_buf);
1696         }
1697         seq_putc(m, '\n');
1698 #undef STATBIT
1699 #undef INFOBIT
1702 static int uart_proc_show(struct seq_file *m, void *v)
1704         struct tty_driver *ttydrv = m->private;
1705         struct uart_driver *drv = ttydrv->driver_state;
1706         int i;
1708         seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1709                         "", "", "");
1710         for (i = 0; i < drv->nr; i++)
1711                 uart_line_info(m, drv, i);
1712         return 0;
1715 static int uart_proc_open(struct inode *inode, struct file *file)
1717         return single_open(file, uart_proc_show, PDE(inode)->data);
1720 static const struct file_operations uart_proc_fops = {
1721         .owner          = THIS_MODULE,
1722         .open           = uart_proc_open,
1723         .read           = seq_read,
1724         .llseek         = seq_lseek,
1725         .release        = single_release,
1726 };
1727 #endif
1729 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1730 /*
1731  *      uart_console_write - write a console message to a serial port
1732  *      @port: the port to write the message
1733  *      @s: array of characters
1734  *      @count: number of characters in string to write
1735  *      @write: function to write character to port
1736  */
1737 void uart_console_write(struct uart_port *port, const char *s,
1738                         unsigned int count,
1739                         void (*putchar)(struct uart_port *, int))
1741         unsigned int i;
1743         for (i = 0; i < count; i++, s++) {
1744                 if (*s == '\n')
1745                         putchar(port, '\r');
1746                 putchar(port, *s);
1747         }
1749 EXPORT_SYMBOL_GPL(uart_console_write);
1751 /*
1752  *      Check whether an invalid uart number has been specified, and
1753  *      if so, search for the first available port that does have
1754  *      console support.
1755  */
1756 struct uart_port * __init
1757 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1759         int idx = co->index;
1761         if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1762                                      ports[idx].membase == NULL))
1763                 for (idx = 0; idx < nr; idx++)
1764                         if (ports[idx].iobase != 0 ||
1765                             ports[idx].membase != NULL)
1766                                 break;
1768         co->index = idx;
1770         return ports + idx;
1773 /**
1774  *      uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1775  *      @options: pointer to option string
1776  *      @baud: pointer to an 'int' variable for the baud rate.
1777  *      @parity: pointer to an 'int' variable for the parity.
1778  *      @bits: pointer to an 'int' variable for the number of data bits.
1779  *      @flow: pointer to an 'int' variable for the flow control character.
1780  *
1781  *      uart_parse_options decodes a string containing the serial console
1782  *      options.  The format of the string is <baud><parity><bits><flow>,
1783  *      eg: 115200n8r
1784  */
1785 void
1786 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1788         char *s = options;
1790         *baud = simple_strtoul(s, NULL, 10);
1791         while (*s >= '0' && *s <= '9')
1792                 s++;
1793         if (*s)
1794                 *parity = *s++;
1795         if (*s)
1796                 *bits = *s++ - '0';
1797         if (*s)
1798                 *flow = *s;
1800 EXPORT_SYMBOL_GPL(uart_parse_options);
1802 struct baud_rates {
1803         unsigned int rate;
1804         unsigned int cflag;
1805 };
1807 static const struct baud_rates baud_rates[] = {
1808         { 921600, B921600 },
1809         { 460800, B460800 },
1810         { 230400, B230400 },
1811         { 115200, B115200 },
1812         {  57600, B57600  },
1813         {  38400, B38400  },
1814         {  19200, B19200  },
1815         {   9600, B9600   },
1816         {   4800, B4800   },
1817         {   2400, B2400   },
1818         {   1200, B1200   },
1819         {      0, B38400  }
1820 };
1822 /**
1823  *      uart_set_options - setup the serial console parameters
1824  *      @port: pointer to the serial ports uart_port structure
1825  *      @co: console pointer
1826  *      @baud: baud rate
1827  *      @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1828  *      @bits: number of data bits
1829  *      @flow: flow control character - 'r' (rts)
1830  */
1831 int
1832 uart_set_options(struct uart_port *port, struct console *co,
1833                  int baud, int parity, int bits, int flow)
1835         struct ktermios termios;
1836         static struct ktermios dummy;
1837         int i;
1839         /*
1840          * Ensure that the serial console lock is initialised
1841          * early.
1842          */
1843         spin_lock_init(&port->lock);
1844         lockdep_set_class(&port->lock, &port_lock_key);
1846         memset(&termios, 0, sizeof(struct ktermios));
1848         termios.c_cflag = CREAD | HUPCL | CLOCAL;
1850         /*
1851          * Construct a cflag setting.
1852          */
1853         for (i = 0; baud_rates[i].rate; i++)
1854                 if (baud_rates[i].rate <= baud)
1855                         break;
1857         termios.c_cflag |= baud_rates[i].cflag;
1859         if (bits == 7)
1860                 termios.c_cflag |= CS7;
1861         else
1862                 termios.c_cflag |= CS8;
1864         switch (parity) {
1865         case 'o': case 'O':
1866                 termios.c_cflag |= PARODD;
1867                 /*fall through*/
1868         case 'e': case 'E':
1869                 termios.c_cflag |= PARENB;
1870                 break;
1871         }
1873         if (flow == 'r')
1874                 termios.c_cflag |= CRTSCTS;
1876         /*
1877          * some uarts on other side don't support no flow control.
1878          * So we set * DTR in host uart to make them happy
1879          */
1880         port->mctrl |= TIOCM_DTR;
1882         port->ops->set_termios(port, &termios, &dummy);
1883         /*
1884          * Allow the setting of the UART parameters with a NULL console
1885          * too:
1886          */
1887         if (co)
1888                 co->cflag = termios.c_cflag;
1890         return 0;
1892 EXPORT_SYMBOL_GPL(uart_set_options);
1893 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1895 /**
1896  * uart_change_pm - set power state of the port
1897  *
1898  * @state: port descriptor
1899  * @pm_state: new state
1900  *
1901  * Locking: port->mutex has to be held
1902  */
1903 static void uart_change_pm(struct uart_state *state, int pm_state)
1905         struct uart_port *port = state->uart_port;
1907         if (state->pm_state != pm_state) {
1908                 if (port->ops->pm)
1909                         port->ops->pm(port, pm_state, state->pm_state);
1910                 state->pm_state = pm_state;
1911         }
1914 struct uart_match {
1915         struct uart_port *port;
1916         struct uart_driver *driver;
1917 };
1919 static int serial_match_port(struct device *dev, void *data)
1921         struct uart_match *match = data;
1922         struct tty_driver *tty_drv = match->driver->tty_driver;
1923         dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1924                 match->port->line;
1926         return dev->devt == devt; /* Actually, only one tty per port */
1929 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1931         struct uart_state *state = drv->state + uport->line;
1932         struct tty_port *port = &state->port;
1933         struct device *tty_dev;
1934         struct uart_match match = {uport, drv};
1936         mutex_lock(&port->mutex);
1938         tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1939         if (device_may_wakeup(tty_dev)) {
1940                 if (!enable_irq_wake(uport->irq))
1941                         uport->irq_wake = 1;
1942                 put_device(tty_dev);
1943                 mutex_unlock(&port->mutex);
1944                 return 0;
1945         }
1946         if (console_suspend_enabled || !uart_console(uport))
1947                 uport->suspended = 1;
1949         if (port->flags & ASYNC_INITIALIZED) {
1950                 const struct uart_ops *ops = uport->ops;
1951                 int tries;
1953                 if (console_suspend_enabled || !uart_console(uport)) {
1954                         set_bit(ASYNCB_SUSPENDED, &port->flags);
1955                         clear_bit(ASYNCB_INITIALIZED, &port->flags);
1957                         spin_lock_irq(&uport->lock);
1958                         ops->stop_tx(uport);
1959                         ops->set_mctrl(uport, 0);
1960                         ops->stop_rx(uport);
1961                         spin_unlock_irq(&uport->lock);
1962                 }
1964                 /*
1965                  * Wait for the transmitter to empty.
1966                  */
1967                 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1968                         msleep(10);
1969                 if (!tries)
1970                         printk(KERN_ERR "%s%s%s%d: Unable to drain "
1971                                         "transmitter\n",
1972                                uport->dev ? dev_name(uport->dev) : "",
1973                                uport->dev ? ": " : "",
1974                                drv->dev_name,
1975                                drv->tty_driver->name_base + uport->line);
1977                 if (console_suspend_enabled || !uart_console(uport))
1978                         ops->shutdown(uport);
1979         }
1981         /*
1982          * Disable the console device before suspending.
1983          */
1984         if (console_suspend_enabled && uart_console(uport))
1985                 console_stop(uport->cons);
1987         if (console_suspend_enabled || !uart_console(uport))
1988                 uart_change_pm(state, 3);
1990         mutex_unlock(&port->mutex);
1992         return 0;
1995 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1997         struct uart_state *state = drv->state + uport->line;
1998         struct tty_port *port = &state->port;
1999         struct device *tty_dev;
2000         struct uart_match match = {uport, drv};
2001         struct ktermios termios;
2003         mutex_lock(&port->mutex);
2005         tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2006         if (!uport->suspended && device_may_wakeup(tty_dev)) {
2007                 if (uport->irq_wake) {
2008                         disable_irq_wake(uport->irq);
2009                         uport->irq_wake = 0;
2010                 }
2011                 mutex_unlock(&port->mutex);
2012                 return 0;
2013         }
2014         uport->suspended = 0;
2016         /*
2017          * Re-enable the console device after suspending.
2018          */
2019         if (uart_console(uport)) {
2020                 /*
2021                  * First try to use the console cflag setting.
2022                  */
2023                 memset(&termios, 0, sizeof(struct ktermios));
2024                 termios.c_cflag = uport->cons->cflag;
2026                 /*
2027                  * If that's unset, use the tty termios setting.
2028                  */
2029                 if (port->tty && termios.c_cflag == 0)
2030                         termios = port->tty->termios;
2032                 if (console_suspend_enabled)
2033                         uart_change_pm(state, 0);
2034                 uport->ops->set_termios(uport, &termios, NULL);
2035                 if (console_suspend_enabled)
2036                         console_start(uport->cons);
2037         }
2039         if (port->flags & ASYNC_SUSPENDED) {
2040                 const struct uart_ops *ops = uport->ops;
2041                 int ret;
2043                 uart_change_pm(state, 0);
2044                 spin_lock_irq(&uport->lock);
2045                 ops->set_mctrl(uport, 0);
2046                 spin_unlock_irq(&uport->lock);
2047                 if (console_suspend_enabled || !uart_console(uport)) {
2048                         /* Protected by port mutex for now */
2049                         struct tty_struct *tty = port->tty;
2050                         ret = ops->startup(uport);
2051                         if (ret == 0) {
2052                                 if (tty)
2053                                         uart_change_speed(tty, state, NULL);
2054                                 spin_lock_irq(&uport->lock);
2055                                 ops->set_mctrl(uport, uport->mctrl);
2056                                 ops->start_tx(uport);
2057                                 spin_unlock_irq(&uport->lock);
2058                                 set_bit(ASYNCB_INITIALIZED, &port->flags);
2059                         } else {
2060                                 /*
2061                                  * Failed to resume - maybe hardware went away?
2062                                  * Clear the "initialized" flag so we won't try
2063                                  * to call the low level drivers shutdown method.
2064                                  */
2065                                 uart_shutdown(tty, state);
2066                         }
2067                 }
2069                 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2070         }
2072         mutex_unlock(&port->mutex);
2074         return 0;
2077 static inline void
2078 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2080         char address[64];
2082         switch (port->iotype) {
2083         case UPIO_PORT:
2084                 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2085                 break;
2086         case UPIO_HUB6:
2087                 snprintf(address, sizeof(address),
2088                          "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2089                 break;
2090         case UPIO_MEM:
2091         case UPIO_MEM32:
2092         case UPIO_AU:
2093         case UPIO_TSI:
2094                 snprintf(address, sizeof(address),
2095                          "MMIO 0x%llx", (unsigned long long)port->mapbase);
2096                 break;
2097         default:
2098                 strlcpy(address, "*unknown*", sizeof(address));
2099                 break;
2100         }
2102         printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2103                port->dev ? dev_name(port->dev) : "",
2104                port->dev ? ": " : "",
2105                drv->dev_name,
2106                drv->tty_driver->name_base + port->line,
2107                address, port->irq, uart_type(port));
2110 static void
2111 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2112                     struct uart_port *port)
2114         unsigned int flags;
2116         /*
2117          * If there isn't a port here, don't do anything further.
2118          */
2119         if (!port->iobase && !port->mapbase && !port->membase)
2120                 return;
2122         /*
2123          * Now do the auto configuration stuff.  Note that config_port
2124          * is expected to claim the resources and map the port for us.
2125          */
2126         flags = 0;
2127         if (port->flags & UPF_AUTO_IRQ)
2128                 flags |= UART_CONFIG_IRQ;
2129         if (port->flags & UPF_BOOT_AUTOCONF) {
2130                 if (!(port->flags & UPF_FIXED_TYPE)) {
2131                         port->type = PORT_UNKNOWN;
2132                         flags |= UART_CONFIG_TYPE;
2133                 }
2134                 port->ops->config_port(port, flags);
2135         }
2137         if (port->type != PORT_UNKNOWN) {
2138                 unsigned long flags;
2140                 uart_report_port(drv, port);
2142                 /* Power up port for set_mctrl() */
2143                 uart_change_pm(state, 0);
2145                 /*
2146                  * Ensure that the modem control lines are de-activated.
2147                  * keep the DTR setting that is set in uart_set_options()
2148                  * We probably don't need a spinlock around this, but
2149                  */
2150                 spin_lock_irqsave(&port->lock, flags);
2151                 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2152                 spin_unlock_irqrestore(&port->lock, flags);
2154                 /*
2155                  * If this driver supports console, and it hasn't been
2156                  * successfully registered yet, try to re-register it.
2157                  * It may be that the port was not available.
2158                  */
2159                 if (port->cons && !(port->cons->flags & CON_ENABLED))
2160                         register_console(port->cons);
2162                 /*
2163                  * Power down all ports by default, except the
2164                  * console if we have one.
2165                  */
2166                 if (!uart_console(port))
2167                         uart_change_pm(state, 3);
2168         }
2171 #ifdef CONFIG_CONSOLE_POLL
2173 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2175         struct uart_driver *drv = driver->driver_state;
2176         struct uart_state *state = drv->state + line;
2177         struct uart_port *port;
2178         int baud = 9600;
2179         int bits = 8;
2180         int parity = 'n';
2181         int flow = 'n';
2182         int ret;
2184         if (!state || !state->uart_port)
2185                 return -1;
2187         port = state->uart_port;
2188         if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2189                 return -1;
2191         if (port->ops->poll_init) {
2192                 struct tty_port *tport = &state->port;
2194                 ret = 0;
2195                 mutex_lock(&tport->mutex);
2196                 /*
2197                  * We don't set ASYNCB_INITIALIZED as we only initialized the
2198                  * hw, e.g. state->xmit is still uninitialized.
2199                  */
2200                 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2201                         ret = port->ops->poll_init(port);
2202                 mutex_unlock(&tport->mutex);
2203                 if (ret)
2204                         return ret;
2205         }
2207         if (options) {
2208                 uart_parse_options(options, &baud, &parity, &bits, &flow);
2209                 return uart_set_options(port, NULL, baud, parity, bits, flow);
2210         }
2212         return 0;
2215 static int uart_poll_get_char(struct tty_driver *driver, int line)
2217         struct uart_driver *drv = driver->driver_state;
2218         struct uart_state *state = drv->state + line;
2219         struct uart_port *port;
2221         if (!state || !state->uart_port)
2222                 return -1;
2224         port = state->uart_port;
2225         return port->ops->poll_get_char(port);
2228 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2230         struct uart_driver *drv = driver->driver_state;
2231         struct uart_state *state = drv->state + line;
2232         struct uart_port *port;
2234         if (!state || !state->uart_port)
2235                 return;
2237         port = state->uart_port;
2238         port->ops->poll_put_char(port, ch);
2240 #endif
2242 static const struct tty_operations uart_ops = {
2243         .open           = uart_open,
2244         .close          = uart_close,
2245         .write          = uart_write,
2246         .put_char       = uart_put_char,
2247         .flush_chars    = uart_flush_chars,
2248         .write_room     = uart_write_room,
2249         .chars_in_buffer= uart_chars_in_buffer,
2250         .flush_buffer   = uart_flush_buffer,
2251         .ioctl          = uart_ioctl,
2252         .throttle       = uart_throttle,
2253         .unthrottle     = uart_unthrottle,
2254         .send_xchar     = uart_send_xchar,
2255         .set_termios    = uart_set_termios,
2256         .set_ldisc      = uart_set_ldisc,
2257         .stop           = uart_stop,
2258         .start          = uart_start,
2259         .hangup         = uart_hangup,
2260         .break_ctl      = uart_break_ctl,
2261         .wait_until_sent= uart_wait_until_sent,
2262 #ifdef CONFIG_PROC_FS
2263         .proc_fops      = &uart_proc_fops,
2264 #endif
2265         .tiocmget       = uart_tiocmget,
2266         .tiocmset       = uart_tiocmset,
2267         .get_icount     = uart_get_icount,
2268 #ifdef CONFIG_CONSOLE_POLL
2269         .poll_init      = uart_poll_init,
2270         .poll_get_char  = uart_poll_get_char,
2271         .poll_put_char  = uart_poll_put_char,
2272 #endif
2273 };
2275 static const struct tty_port_operations uart_port_ops = {
2276         .activate       = uart_port_activate,
2277         .shutdown       = uart_port_shutdown,
2278         .carrier_raised = uart_carrier_raised,
2279         .dtr_rts        = uart_dtr_rts,
2280 };
2282 /**
2283  *      uart_register_driver - register a driver with the uart core layer
2284  *      @drv: low level driver structure
2285  *
2286  *      Register a uart driver with the core driver.  We in turn register
2287  *      with the tty layer, and initialise the core driver per-port state.
2288  *
2289  *      We have a proc file in /proc/tty/driver which is named after the
2290  *      normal driver.
2291  *
2292  *      drv->port should be NULL, and the per-port structures should be
2293  *      registered using uart_add_one_port after this call has succeeded.
2294  */
2295 int uart_register_driver(struct uart_driver *drv)
2297         struct tty_driver *normal;
2298         int i, retval;
2300         BUG_ON(drv->state);
2302         /*
2303          * Maybe we should be using a slab cache for this, especially if
2304          * we have a large number of ports to handle.
2305          */
2306         drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2307         if (!drv->state)
2308                 goto out;
2310         normal = alloc_tty_driver(drv->nr);
2311         if (!normal)
2312                 goto out_kfree;
2314         drv->tty_driver = normal;
2316         normal->driver_name     = drv->driver_name;
2317         normal->name            = drv->dev_name;
2318         normal->major           = drv->major;
2319         normal->minor_start     = drv->minor;
2320         normal->type            = TTY_DRIVER_TYPE_SERIAL;
2321         normal->subtype         = SERIAL_TYPE_NORMAL;
2322         normal->init_termios    = tty_std_termios;
2323         normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2324         normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2325         normal->flags           = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2326         normal->driver_state    = drv;
2327         tty_set_operations(normal, &uart_ops);
2329         /*
2330          * Initialise the UART state(s).
2331          */
2332         for (i = 0; i < drv->nr; i++) {
2333                 struct uart_state *state = drv->state + i;
2334                 struct tty_port *port = &state->port;
2336                 tty_port_init(port);
2337                 port->ops = &uart_port_ops;
2338                 port->close_delay     = HZ / 2; /* .5 seconds */
2339                 port->closing_wait    = 30 * HZ;/* 30 seconds */
2340         }
2342         retval = tty_register_driver(normal);
2343         if (retval >= 0)
2344                 return retval;
2346         for (i = 0; i < drv->nr; i++)
2347                 tty_port_destroy(&drv->state[i].port);
2348         put_tty_driver(normal);
2349 out_kfree:
2350         kfree(drv->state);
2351 out:
2352         return -ENOMEM;
2355 /**
2356  *      uart_unregister_driver - remove a driver from the uart core layer
2357  *      @drv: low level driver structure
2358  *
2359  *      Remove all references to a driver from the core driver.  The low
2360  *      level driver must have removed all its ports via the
2361  *      uart_remove_one_port() if it registered them with uart_add_one_port().
2362  *      (ie, drv->port == NULL)
2363  */
2364 void uart_unregister_driver(struct uart_driver *drv)
2366         struct tty_driver *p = drv->tty_driver;
2367         unsigned int i;
2369         tty_unregister_driver(p);
2370         put_tty_driver(p);
2371         for (i = 0; i < drv->nr; i++)
2372                 tty_port_destroy(&drv->state[i].port);
2373         kfree(drv->state);
2374         drv->state = NULL;
2375         drv->tty_driver = NULL;
2378 struct tty_driver *uart_console_device(struct console *co, int *index)
2380         struct uart_driver *p = co->data;
2381         *index = co->index;
2382         return p->tty_driver;
2385 static ssize_t uart_get_attr_uartclk(struct device *dev,
2386         struct device_attribute *attr, char *buf)
2388         struct serial_struct tmp;
2389         struct tty_port *port = dev_get_drvdata(dev);
2391         uart_get_info(port, &tmp);
2392         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2395 static ssize_t uart_get_attr_type(struct device *dev,
2396         struct device_attribute *attr, char *buf)
2398         struct serial_struct tmp;
2399         struct tty_port *port = dev_get_drvdata(dev);
2401         uart_get_info(port, &tmp);
2402         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2404 static ssize_t uart_get_attr_line(struct device *dev,
2405         struct device_attribute *attr, char *buf)
2407         struct serial_struct tmp;
2408         struct tty_port *port = dev_get_drvdata(dev);
2410         uart_get_info(port, &tmp);
2411         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2414 static ssize_t uart_get_attr_port(struct device *dev,
2415         struct device_attribute *attr, char *buf)
2417         struct serial_struct tmp;
2418         struct tty_port *port = dev_get_drvdata(dev);
2419         unsigned long ioaddr;
2421         uart_get_info(port, &tmp);
2422         ioaddr = tmp.port;
2423         if (HIGH_BITS_OFFSET)
2424                 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2425         return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2428 static ssize_t uart_get_attr_irq(struct device *dev,
2429         struct device_attribute *attr, char *buf)
2431         struct serial_struct tmp;
2432         struct tty_port *port = dev_get_drvdata(dev);
2434         uart_get_info(port, &tmp);
2435         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2438 static ssize_t uart_get_attr_flags(struct device *dev,
2439         struct device_attribute *attr, char *buf)
2441         struct serial_struct tmp;
2442         struct tty_port *port = dev_get_drvdata(dev);
2444         uart_get_info(port, &tmp);
2445         return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2448 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2449         struct device_attribute *attr, char *buf)
2451         struct serial_struct tmp;
2452         struct tty_port *port = dev_get_drvdata(dev);
2454         uart_get_info(port, &tmp);
2455         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2459 static ssize_t uart_get_attr_close_delay(struct device *dev,
2460         struct device_attribute *attr, char *buf)
2462         struct serial_struct tmp;
2463         struct tty_port *port = dev_get_drvdata(dev);
2465         uart_get_info(port, &tmp);
2466         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2470 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2471         struct device_attribute *attr, char *buf)
2473         struct serial_struct tmp;
2474         struct tty_port *port = dev_get_drvdata(dev);
2476         uart_get_info(port, &tmp);
2477         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2480 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2481         struct device_attribute *attr, char *buf)
2483         struct serial_struct tmp;
2484         struct tty_port *port = dev_get_drvdata(dev);
2486         uart_get_info(port, &tmp);
2487         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2490 static ssize_t uart_get_attr_io_type(struct device *dev,
2491         struct device_attribute *attr, char *buf)
2493         struct serial_struct tmp;
2494         struct tty_port *port = dev_get_drvdata(dev);
2496         uart_get_info(port, &tmp);
2497         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2500 static ssize_t uart_get_attr_iomem_base(struct device *dev,
2501         struct device_attribute *attr, char *buf)
2503         struct serial_struct tmp;
2504         struct tty_port *port = dev_get_drvdata(dev);
2506         uart_get_info(port, &tmp);
2507         return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2510 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2511         struct device_attribute *attr, char *buf)
2513         struct serial_struct tmp;
2514         struct tty_port *port = dev_get_drvdata(dev);
2516         uart_get_info(port, &tmp);
2517         return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2520 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2521 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2522 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2523 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2524 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2525 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2526 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2527 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2528 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2529 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2530 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2531 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2532 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2534 static struct attribute *tty_dev_attrs[] = {
2535         &dev_attr_type.attr,
2536         &dev_attr_line.attr,
2537         &dev_attr_port.attr,
2538         &dev_attr_irq.attr,
2539         &dev_attr_flags.attr,
2540         &dev_attr_xmit_fifo_size.attr,
2541         &dev_attr_uartclk.attr,
2542         &dev_attr_close_delay.attr,
2543         &dev_attr_closing_wait.attr,
2544         &dev_attr_custom_divisor.attr,
2545         &dev_attr_io_type.attr,
2546         &dev_attr_iomem_base.attr,
2547         &dev_attr_iomem_reg_shift.attr,
2548         NULL,
2549         };
2551 static const struct attribute_group tty_dev_attr_group = {
2552         .attrs = tty_dev_attrs,
2553         };
2555 static const struct attribute_group *tty_dev_attr_groups[] = {
2556         &tty_dev_attr_group,
2557         NULL
2558         };
2561 /**
2562  *      uart_add_one_port - attach a driver-defined port structure
2563  *      @drv: pointer to the uart low level driver structure for this port
2564  *      @uport: uart port structure to use for this port.
2565  *
2566  *      This allows the driver to register its own uart_port structure
2567  *      with the core driver.  The main purpose is to allow the low
2568  *      level uart drivers to expand uart_port, rather than having yet
2569  *      more levels of structures.
2570  */
2571 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2573         struct uart_state *state;
2574         struct tty_port *port;
2575         int ret = 0;
2576         struct device *tty_dev;
2578         BUG_ON(in_interrupt());
2580         if (uport->line >= drv->nr)
2581                 return -EINVAL;
2583         state = drv->state + uport->line;
2584         port = &state->port;
2586         mutex_lock(&port_mutex);
2587         mutex_lock(&port->mutex);
2588         if (state->uart_port) {
2589                 ret = -EINVAL;
2590                 goto out;
2591         }
2593         state->uart_port = uport;
2594         state->pm_state = -1;
2596         uport->cons = drv->cons;
2597         uport->state = state;
2599         /*
2600          * If this port is a console, then the spinlock is already
2601          * initialised.
2602          */
2603         if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2604                 spin_lock_init(&uport->lock);
2605                 lockdep_set_class(&uport->lock, &port_lock_key);
2606         }
2608         uart_configure_port(drv, state, uport);
2610         /*
2611          * Register the port whether it's detected or not.  This allows
2612          * setserial to be used to alter this ports parameters.
2613          */
2614         tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2615                         uport->line, uport->dev, port, tty_dev_attr_groups);
2616         if (likely(!IS_ERR(tty_dev))) {
2617                 device_set_wakeup_capable(tty_dev, 1);
2618         } else {
2619                 printk(KERN_ERR "Cannot register tty device on line %d\n",
2620                        uport->line);
2621         }
2623         /*
2624          * Ensure UPF_DEAD is not set.
2625          */
2626         uport->flags &= ~UPF_DEAD;
2628  out:
2629         mutex_unlock(&port->mutex);
2630         mutex_unlock(&port_mutex);
2632         return ret;
2635 /**
2636  *      uart_remove_one_port - detach a driver defined port structure
2637  *      @drv: pointer to the uart low level driver structure for this port
2638  *      @uport: uart port structure for this port
2639  *
2640  *      This unhooks (and hangs up) the specified port structure from the
2641  *      core driver.  No further calls will be made to the low-level code
2642  *      for this port.
2643  */
2644 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2646         struct uart_state *state = drv->state + uport->line;
2647         struct tty_port *port = &state->port;
2649         BUG_ON(in_interrupt());
2651         if (state->uart_port != uport)
2652                 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2653                         state->uart_port, uport);
2655         mutex_lock(&port_mutex);
2657         /*
2658          * Mark the port "dead" - this prevents any opens from
2659          * succeeding while we shut down the port.
2660          */
2661         mutex_lock(&port->mutex);
2662         uport->flags |= UPF_DEAD;
2663         mutex_unlock(&port->mutex);
2665         /*
2666          * Remove the devices from the tty layer
2667          */
2668         tty_unregister_device(drv->tty_driver, uport->line);
2670         if (port->tty)
2671                 tty_vhangup(port->tty);
2673         /*
2674          * Free the port IO and memory resources, if any.
2675          */
2676         if (uport->type != PORT_UNKNOWN)
2677                 uport->ops->release_port(uport);
2679         /*
2680          * Indicate that there isn't a port here anymore.
2681          */
2682         uport->type = PORT_UNKNOWN;
2684         state->uart_port = NULL;
2685         mutex_unlock(&port_mutex);
2687         return 0;
2690 /*
2691  *      Are the two ports equivalent?
2692  */
2693 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2695         if (port1->iotype != port2->iotype)
2696                 return 0;
2698         switch (port1->iotype) {
2699         case UPIO_PORT:
2700                 return (port1->iobase == port2->iobase);
2701         case UPIO_HUB6:
2702                 return (port1->iobase == port2->iobase) &&
2703                        (port1->hub6   == port2->hub6);
2704         case UPIO_MEM:
2705         case UPIO_MEM32:
2706         case UPIO_AU:
2707         case UPIO_TSI:
2708                 return (port1->mapbase == port2->mapbase);
2709         }
2710         return 0;
2712 EXPORT_SYMBOL(uart_match_port);
2714 /**
2715  *      uart_handle_dcd_change - handle a change of carrier detect state
2716  *      @uport: uart_port structure for the open port
2717  *      @status: new carrier detect status, nonzero if active
2718  */
2719 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2721         struct uart_state *state = uport->state;
2722         struct tty_port *port = &state->port;
2723         struct tty_ldisc *ld = NULL;
2724         struct pps_event_time ts;
2725         struct tty_struct *tty = port->tty;
2727         if (tty)
2728                 ld = tty_ldisc_ref(tty);
2729         if (ld && ld->ops->dcd_change)
2730                 pps_get_ts(&ts);
2732         uport->icount.dcd++;
2733 #ifdef CONFIG_HARD_PPS
2734         if ((uport->flags & UPF_HARDPPS_CD) && status)
2735                 hardpps();
2736 #endif
2738         if (port->flags & ASYNC_CHECK_CD) {
2739                 if (status)
2740                         wake_up_interruptible(&port->open_wait);
2741                 else if (tty)
2742                         tty_hangup(tty);
2743         }
2745         if (ld && ld->ops->dcd_change)
2746                 ld->ops->dcd_change(tty, status, &ts);
2747         if (ld)
2748                 tty_ldisc_deref(ld);
2750 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2752 /**
2753  *      uart_handle_cts_change - handle a change of clear-to-send state
2754  *      @uport: uart_port structure for the open port
2755  *      @status: new clear to send status, nonzero if active
2756  */
2757 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2759         struct tty_port *port = &uport->state->port;
2760         struct tty_struct *tty = port->tty;
2762         uport->icount.cts++;
2764         if (tty_port_cts_enabled(port)) {
2765                 if (tty->hw_stopped) {
2766                         if (status) {
2767                                 tty->hw_stopped = 0;
2768                                 uport->ops->start_tx(uport);
2769                                 uart_write_wakeup(uport);
2770                         }
2771                 } else {
2772                         if (!status) {
2773                                 tty->hw_stopped = 1;
2774                                 uport->ops->stop_tx(uport);
2775                         }
2776                 }
2777         }
2779 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2781 /**
2782  * uart_insert_char - push a char to the uart layer
2783  *
2784  * User is responsible to call tty_flip_buffer_push when they are done with
2785  * insertion.
2786  *
2787  * @port: corresponding port
2788  * @status: state of the serial port RX buffer (LSR for 8250)
2789  * @overrun: mask of overrun bits in @status
2790  * @ch: character to push
2791  * @flag: flag for the character (see TTY_NORMAL and friends)
2792  */
2793 void uart_insert_char(struct uart_port *port, unsigned int status,
2794                  unsigned int overrun, unsigned int ch, unsigned int flag)
2796         struct tty_struct *tty = port->state->port.tty;
2798         if ((status & port->ignore_status_mask & ~overrun) == 0)
2799                 if (tty_insert_flip_char(tty, ch, flag) == 0)
2800                         ++port->icount.buf_overrun;
2802         /*
2803          * Overrun is special.  Since it's reported immediately,
2804          * it doesn't affect the current character.
2805          */
2806         if (status & ~port->ignore_status_mask & overrun)
2807                 if (tty_insert_flip_char(tty, 0, TTY_OVERRUN) == 0)
2808                         ++port->icount.buf_overrun;
2810 EXPORT_SYMBOL_GPL(uart_insert_char);
2812 EXPORT_SYMBOL(uart_write_wakeup);
2813 EXPORT_SYMBOL(uart_register_driver);
2814 EXPORT_SYMBOL(uart_unregister_driver);
2815 EXPORT_SYMBOL(uart_suspend_port);
2816 EXPORT_SYMBOL(uart_resume_port);
2817 EXPORT_SYMBOL(uart_add_one_port);
2818 EXPORT_SYMBOL(uart_remove_one_port);
2820 MODULE_DESCRIPTION("Serial driver core");
2821 MODULE_LICENSE("GPL");