Linux 4.1.16
[linux/fpc-iii.git] / drivers / tty / serial / serial_core.c
blobec540445bb71f4386d4a30a66a6b7531ef919618
1 /*
2 * Driver core for serial ports
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
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.
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.
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
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/of.h>
30 #include <linux/proc_fs.h>
31 #include <linux/seq_file.h>
32 #include <linux/device.h>
33 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
34 #include <linux/serial_core.h>
35 #include <linux/delay.h>
36 #include <linux/mutex.h>
38 #include <asm/irq.h>
39 #include <asm/uaccess.h>
42 * This is used to lock changes in serial line configuration.
44 static DEFINE_MUTEX(port_mutex);
47 * lockdep: port->lock is initialized in two places, but we
48 * want only one lock-class:
50 static struct lock_class_key port_lock_key;
52 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
54 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
55 struct ktermios *old_termios);
56 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
57 static void uart_change_pm(struct uart_state *state,
58 enum uart_pm_state pm_state);
60 static void uart_port_shutdown(struct tty_port *port);
62 static int uart_dcd_enabled(struct uart_port *uport)
64 return !!(uport->status & UPSTAT_DCD_ENABLE);
68 * This routine is used by the interrupt handler to schedule processing in
69 * the software interrupt portion of the driver.
71 void uart_write_wakeup(struct uart_port *port)
73 struct uart_state *state = port->state;
75 * This means you called this function _after_ the port was
76 * closed. No cookie for you.
78 BUG_ON(!state);
79 tty_wakeup(state->port.tty);
82 static void uart_stop(struct tty_struct *tty)
84 struct uart_state *state = tty->driver_data;
85 struct uart_port *port = state->uart_port;
86 unsigned long flags;
88 spin_lock_irqsave(&port->lock, flags);
89 port->ops->stop_tx(port);
90 spin_unlock_irqrestore(&port->lock, flags);
93 static void __uart_start(struct tty_struct *tty)
95 struct uart_state *state = tty->driver_data;
96 struct uart_port *port = state->uart_port;
98 if (!uart_tx_stopped(port))
99 port->ops->start_tx(port);
102 static void uart_start(struct tty_struct *tty)
104 struct uart_state *state = tty->driver_data;
105 struct uart_port *port = state->uart_port;
106 unsigned long flags;
108 spin_lock_irqsave(&port->lock, flags);
109 __uart_start(tty);
110 spin_unlock_irqrestore(&port->lock, flags);
113 static inline void
114 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
116 unsigned long flags;
117 unsigned int old;
119 spin_lock_irqsave(&port->lock, flags);
120 old = port->mctrl;
121 port->mctrl = (old & ~clear) | set;
122 if (old != port->mctrl)
123 port->ops->set_mctrl(port, port->mctrl);
124 spin_unlock_irqrestore(&port->lock, flags);
127 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
128 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
131 * Startup the port. This will be called once per open. All calls
132 * will be serialised by the per-port mutex.
134 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
135 int init_hw)
137 struct uart_port *uport = state->uart_port;
138 unsigned long page;
139 int retval = 0;
141 if (uport->type == PORT_UNKNOWN)
142 return 1;
145 * Make sure the device is in D0 state.
147 uart_change_pm(state, UART_PM_STATE_ON);
150 * Initialise and allocate the transmit and temporary
151 * buffer.
153 if (!state->xmit.buf) {
154 /* This is protected by the per port mutex */
155 page = get_zeroed_page(GFP_KERNEL);
156 if (!page)
157 return -ENOMEM;
159 state->xmit.buf = (unsigned char *) page;
160 uart_circ_clear(&state->xmit);
163 retval = uport->ops->startup(uport);
164 if (retval == 0) {
165 if (uart_console(uport) && uport->cons->cflag) {
166 tty->termios.c_cflag = uport->cons->cflag;
167 uport->cons->cflag = 0;
170 * Initialise the hardware port settings.
172 uart_change_speed(tty, state, NULL);
174 if (init_hw) {
176 * Setup the RTS and DTR signals once the
177 * port is open and ready to respond.
179 if (tty->termios.c_cflag & CBAUD)
180 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
185 * This is to allow setserial on this port. People may want to set
186 * port/irq/type and then reconfigure the port properly if it failed
187 * now.
189 if (retval && capable(CAP_SYS_ADMIN))
190 return 1;
192 return retval;
195 static int uart_startup(struct tty_struct *tty, struct uart_state *state,
196 int init_hw)
198 struct tty_port *port = &state->port;
199 int retval;
201 if (port->flags & ASYNC_INITIALIZED)
202 return 0;
205 * Set the TTY IO error marker - we will only clear this
206 * once we have successfully opened the port.
208 set_bit(TTY_IO_ERROR, &tty->flags);
210 retval = uart_port_startup(tty, state, init_hw);
211 if (!retval) {
212 set_bit(ASYNCB_INITIALIZED, &port->flags);
213 clear_bit(TTY_IO_ERROR, &tty->flags);
214 } else if (retval > 0)
215 retval = 0;
217 return retval;
221 * This routine will shutdown a serial port; interrupts are disabled, and
222 * DTR is dropped if the hangup on close termio flag is on. Calls to
223 * uart_shutdown are serialised by the per-port semaphore.
225 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
227 struct uart_port *uport = state->uart_port;
228 struct tty_port *port = &state->port;
231 * Set the TTY IO error marker
233 if (tty)
234 set_bit(TTY_IO_ERROR, &tty->flags);
236 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
238 * Turn off DTR and RTS early.
240 if (uart_console(uport) && tty)
241 uport->cons->cflag = tty->termios.c_cflag;
243 if (!tty || (tty->termios.c_cflag & HUPCL))
244 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
246 uart_port_shutdown(port);
250 * It's possible for shutdown to be called after suspend if we get
251 * a DCD drop (hangup) at just the right time. Clear suspended bit so
252 * we don't try to resume a port that has been shutdown.
254 clear_bit(ASYNCB_SUSPENDED, &port->flags);
257 * Free the transmit buffer page.
259 if (state->xmit.buf) {
260 free_page((unsigned long)state->xmit.buf);
261 state->xmit.buf = NULL;
266 * uart_update_timeout - update per-port FIFO timeout.
267 * @port: uart_port structure describing the port
268 * @cflag: termios cflag value
269 * @baud: speed of the port
271 * Set the port FIFO timeout value. The @cflag value should
272 * reflect the actual hardware settings.
274 void
275 uart_update_timeout(struct uart_port *port, unsigned int cflag,
276 unsigned int baud)
278 unsigned int bits;
280 /* byte size and parity */
281 switch (cflag & CSIZE) {
282 case CS5:
283 bits = 7;
284 break;
285 case CS6:
286 bits = 8;
287 break;
288 case CS7:
289 bits = 9;
290 break;
291 default:
292 bits = 10;
293 break; /* CS8 */
296 if (cflag & CSTOPB)
297 bits++;
298 if (cflag & PARENB)
299 bits++;
302 * The total number of bits to be transmitted in the fifo.
304 bits = bits * port->fifosize;
307 * Figure the timeout to send the above number of bits.
308 * Add .02 seconds of slop
310 port->timeout = (HZ * bits) / baud + HZ/50;
313 EXPORT_SYMBOL(uart_update_timeout);
316 * uart_get_baud_rate - return baud rate for a particular port
317 * @port: uart_port structure describing the port in question.
318 * @termios: desired termios settings.
319 * @old: old termios (or NULL)
320 * @min: minimum acceptable baud rate
321 * @max: maximum acceptable baud rate
323 * Decode the termios structure into a numeric baud rate,
324 * taking account of the magic 38400 baud rate (with spd_*
325 * flags), and mapping the %B0 rate to 9600 baud.
327 * If the new baud rate is invalid, try the old termios setting.
328 * If it's still invalid, we try 9600 baud.
330 * Update the @termios structure to reflect the baud rate
331 * we're actually going to be using. Don't do this for the case
332 * where B0 is requested ("hang up").
334 unsigned int
335 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
336 struct ktermios *old, unsigned int min, unsigned int max)
338 unsigned int try, baud, altbaud = 38400;
339 int hung_up = 0;
340 upf_t flags = port->flags & UPF_SPD_MASK;
342 if (flags == UPF_SPD_HI)
343 altbaud = 57600;
344 else if (flags == UPF_SPD_VHI)
345 altbaud = 115200;
346 else if (flags == UPF_SPD_SHI)
347 altbaud = 230400;
348 else if (flags == UPF_SPD_WARP)
349 altbaud = 460800;
351 for (try = 0; try < 2; try++) {
352 baud = tty_termios_baud_rate(termios);
355 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
356 * Die! Die! Die!
358 if (try == 0 && baud == 38400)
359 baud = altbaud;
362 * Special case: B0 rate.
364 if (baud == 0) {
365 hung_up = 1;
366 baud = 9600;
369 if (baud >= min && baud <= max)
370 return baud;
373 * Oops, the quotient was zero. Try again with
374 * the old baud rate if possible.
376 termios->c_cflag &= ~CBAUD;
377 if (old) {
378 baud = tty_termios_baud_rate(old);
379 if (!hung_up)
380 tty_termios_encode_baud_rate(termios,
381 baud, baud);
382 old = NULL;
383 continue;
387 * As a last resort, if the range cannot be met then clip to
388 * the nearest chip supported rate.
390 if (!hung_up) {
391 if (baud <= min)
392 tty_termios_encode_baud_rate(termios,
393 min + 1, min + 1);
394 else
395 tty_termios_encode_baud_rate(termios,
396 max - 1, max - 1);
399 /* Should never happen */
400 WARN_ON(1);
401 return 0;
404 EXPORT_SYMBOL(uart_get_baud_rate);
407 * uart_get_divisor - return uart clock divisor
408 * @port: uart_port structure describing the port.
409 * @baud: desired baud rate
411 * Calculate the uart clock divisor for the port.
413 unsigned int
414 uart_get_divisor(struct uart_port *port, unsigned int baud)
416 unsigned int quot;
419 * Old custom speed handling.
421 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
422 quot = port->custom_divisor;
423 else
424 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
426 return quot;
429 EXPORT_SYMBOL(uart_get_divisor);
431 /* Caller holds port mutex */
432 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
433 struct ktermios *old_termios)
435 struct uart_port *uport = state->uart_port;
436 struct ktermios *termios;
437 int hw_stopped;
440 * If we have no tty, termios, or the port does not exist,
441 * then we can't set the parameters for this port.
443 if (!tty || uport->type == PORT_UNKNOWN)
444 return;
446 termios = &tty->termios;
447 uport->ops->set_termios(uport, termios, old_termios);
450 * Set modem status enables based on termios cflag
452 spin_lock_irq(&uport->lock);
453 if (termios->c_cflag & CRTSCTS)
454 uport->status |= UPSTAT_CTS_ENABLE;
455 else
456 uport->status &= ~UPSTAT_CTS_ENABLE;
458 if (termios->c_cflag & CLOCAL)
459 uport->status &= ~UPSTAT_DCD_ENABLE;
460 else
461 uport->status |= UPSTAT_DCD_ENABLE;
463 /* reset sw-assisted CTS flow control based on (possibly) new mode */
464 hw_stopped = uport->hw_stopped;
465 uport->hw_stopped = uart_softcts_mode(uport) &&
466 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
467 if (uport->hw_stopped) {
468 if (!hw_stopped)
469 uport->ops->stop_tx(uport);
470 } else {
471 if (hw_stopped)
472 __uart_start(tty);
474 spin_unlock_irq(&uport->lock);
477 static inline int __uart_put_char(struct uart_port *port,
478 struct circ_buf *circ, unsigned char c)
480 unsigned long flags;
481 int ret = 0;
483 if (!circ->buf)
484 return 0;
486 spin_lock_irqsave(&port->lock, flags);
487 if (uart_circ_chars_free(circ) != 0) {
488 circ->buf[circ->head] = c;
489 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
490 ret = 1;
492 spin_unlock_irqrestore(&port->lock, flags);
493 return ret;
496 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
498 struct uart_state *state = tty->driver_data;
500 return __uart_put_char(state->uart_port, &state->xmit, ch);
503 static void uart_flush_chars(struct tty_struct *tty)
505 uart_start(tty);
508 static int uart_write(struct tty_struct *tty,
509 const unsigned char *buf, int count)
511 struct uart_state *state = tty->driver_data;
512 struct uart_port *port;
513 struct circ_buf *circ;
514 unsigned long flags;
515 int c, ret = 0;
518 * This means you called this function _after_ the port was
519 * closed. No cookie for you.
521 if (!state) {
522 WARN_ON(1);
523 return -EL3HLT;
526 port = state->uart_port;
527 circ = &state->xmit;
529 if (!circ->buf)
530 return 0;
532 spin_lock_irqsave(&port->lock, flags);
533 while (1) {
534 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
535 if (count < c)
536 c = count;
537 if (c <= 0)
538 break;
539 memcpy(circ->buf + circ->head, buf, c);
540 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
541 buf += c;
542 count -= c;
543 ret += c;
546 __uart_start(tty);
547 spin_unlock_irqrestore(&port->lock, flags);
549 return ret;
552 static int uart_write_room(struct tty_struct *tty)
554 struct uart_state *state = tty->driver_data;
555 unsigned long flags;
556 int ret;
558 spin_lock_irqsave(&state->uart_port->lock, flags);
559 ret = uart_circ_chars_free(&state->xmit);
560 spin_unlock_irqrestore(&state->uart_port->lock, flags);
561 return ret;
564 static int uart_chars_in_buffer(struct tty_struct *tty)
566 struct uart_state *state = tty->driver_data;
567 unsigned long flags;
568 int ret;
570 spin_lock_irqsave(&state->uart_port->lock, flags);
571 ret = uart_circ_chars_pending(&state->xmit);
572 spin_unlock_irqrestore(&state->uart_port->lock, flags);
573 return ret;
576 static void uart_flush_buffer(struct tty_struct *tty)
578 struct uart_state *state = tty->driver_data;
579 struct uart_port *port;
580 unsigned long flags;
583 * This means you called this function _after_ the port was
584 * closed. No cookie for you.
586 if (!state) {
587 WARN_ON(1);
588 return;
591 port = state->uart_port;
592 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
594 spin_lock_irqsave(&port->lock, flags);
595 uart_circ_clear(&state->xmit);
596 if (port->ops->flush_buffer)
597 port->ops->flush_buffer(port);
598 spin_unlock_irqrestore(&port->lock, flags);
599 tty_wakeup(tty);
603 * This function is used to send a high-priority XON/XOFF character to
604 * the device
606 static void uart_send_xchar(struct tty_struct *tty, char ch)
608 struct uart_state *state = tty->driver_data;
609 struct uart_port *port = state->uart_port;
610 unsigned long flags;
612 if (port->ops->send_xchar)
613 port->ops->send_xchar(port, ch);
614 else {
615 spin_lock_irqsave(&port->lock, flags);
616 port->x_char = ch;
617 if (ch)
618 port->ops->start_tx(port);
619 spin_unlock_irqrestore(&port->lock, flags);
623 static void uart_throttle(struct tty_struct *tty)
625 struct uart_state *state = tty->driver_data;
626 struct uart_port *port = state->uart_port;
627 upstat_t mask = 0;
629 if (I_IXOFF(tty))
630 mask |= UPSTAT_AUTOXOFF;
631 if (tty->termios.c_cflag & CRTSCTS)
632 mask |= UPSTAT_AUTORTS;
634 if (port->status & mask) {
635 port->ops->throttle(port);
636 mask &= ~port->status;
639 if (mask & UPSTAT_AUTOXOFF)
640 uart_send_xchar(tty, STOP_CHAR(tty));
642 if (mask & UPSTAT_AUTORTS)
643 uart_clear_mctrl(port, TIOCM_RTS);
646 static void uart_unthrottle(struct tty_struct *tty)
648 struct uart_state *state = tty->driver_data;
649 struct uart_port *port = state->uart_port;
650 upstat_t mask = 0;
652 if (I_IXOFF(tty))
653 mask |= UPSTAT_AUTOXOFF;
654 if (tty->termios.c_cflag & CRTSCTS)
655 mask |= UPSTAT_AUTORTS;
657 if (port->status & mask) {
658 port->ops->unthrottle(port);
659 mask &= ~port->status;
662 if (mask & UPSTAT_AUTOXOFF)
663 uart_send_xchar(tty, START_CHAR(tty));
665 if (mask & UPSTAT_AUTORTS)
666 uart_set_mctrl(port, TIOCM_RTS);
669 static void do_uart_get_info(struct tty_port *port,
670 struct serial_struct *retinfo)
672 struct uart_state *state = container_of(port, struct uart_state, port);
673 struct uart_port *uport = state->uart_port;
675 memset(retinfo, 0, sizeof(*retinfo));
677 retinfo->type = uport->type;
678 retinfo->line = uport->line;
679 retinfo->port = uport->iobase;
680 if (HIGH_BITS_OFFSET)
681 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
682 retinfo->irq = uport->irq;
683 retinfo->flags = uport->flags;
684 retinfo->xmit_fifo_size = uport->fifosize;
685 retinfo->baud_base = uport->uartclk / 16;
686 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
687 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
688 ASYNC_CLOSING_WAIT_NONE :
689 jiffies_to_msecs(port->closing_wait) / 10;
690 retinfo->custom_divisor = uport->custom_divisor;
691 retinfo->hub6 = uport->hub6;
692 retinfo->io_type = uport->iotype;
693 retinfo->iomem_reg_shift = uport->regshift;
694 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
697 static void uart_get_info(struct tty_port *port,
698 struct serial_struct *retinfo)
700 /* Ensure the state we copy is consistent and no hardware changes
701 occur as we go */
702 mutex_lock(&port->mutex);
703 do_uart_get_info(port, retinfo);
704 mutex_unlock(&port->mutex);
707 static int uart_get_info_user(struct tty_port *port,
708 struct serial_struct __user *retinfo)
710 struct serial_struct tmp;
711 uart_get_info(port, &tmp);
713 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
714 return -EFAULT;
715 return 0;
718 static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
719 struct uart_state *state,
720 struct serial_struct *new_info)
722 struct uart_port *uport = state->uart_port;
723 unsigned long new_port;
724 unsigned int change_irq, change_port, closing_wait;
725 unsigned int old_custom_divisor, close_delay;
726 upf_t old_flags, new_flags;
727 int retval = 0;
729 new_port = new_info->port;
730 if (HIGH_BITS_OFFSET)
731 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
733 new_info->irq = irq_canonicalize(new_info->irq);
734 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
735 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
736 ASYNC_CLOSING_WAIT_NONE :
737 msecs_to_jiffies(new_info->closing_wait * 10);
740 change_irq = !(uport->flags & UPF_FIXED_PORT)
741 && new_info->irq != uport->irq;
744 * Since changing the 'type' of the port changes its resource
745 * allocations, we should treat type changes the same as
746 * IO port changes.
748 change_port = !(uport->flags & UPF_FIXED_PORT)
749 && (new_port != uport->iobase ||
750 (unsigned long)new_info->iomem_base != uport->mapbase ||
751 new_info->hub6 != uport->hub6 ||
752 new_info->io_type != uport->iotype ||
753 new_info->iomem_reg_shift != uport->regshift ||
754 new_info->type != uport->type);
756 old_flags = uport->flags;
757 new_flags = new_info->flags;
758 old_custom_divisor = uport->custom_divisor;
760 if (!capable(CAP_SYS_ADMIN)) {
761 retval = -EPERM;
762 if (change_irq || change_port ||
763 (new_info->baud_base != uport->uartclk / 16) ||
764 (close_delay != port->close_delay) ||
765 (closing_wait != port->closing_wait) ||
766 (new_info->xmit_fifo_size &&
767 new_info->xmit_fifo_size != uport->fifosize) ||
768 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
769 goto exit;
770 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
771 (new_flags & UPF_USR_MASK));
772 uport->custom_divisor = new_info->custom_divisor;
773 goto check_and_exit;
777 * Ask the low level driver to verify the settings.
779 if (uport->ops->verify_port)
780 retval = uport->ops->verify_port(uport, new_info);
782 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
783 (new_info->baud_base < 9600))
784 retval = -EINVAL;
786 if (retval)
787 goto exit;
789 if (change_port || change_irq) {
790 retval = -EBUSY;
793 * Make sure that we are the sole user of this port.
795 if (tty_port_users(port) > 1)
796 goto exit;
799 * We need to shutdown the serial port at the old
800 * port/type/irq combination.
802 uart_shutdown(tty, state);
805 if (change_port) {
806 unsigned long old_iobase, old_mapbase;
807 unsigned int old_type, old_iotype, old_hub6, old_shift;
809 old_iobase = uport->iobase;
810 old_mapbase = uport->mapbase;
811 old_type = uport->type;
812 old_hub6 = uport->hub6;
813 old_iotype = uport->iotype;
814 old_shift = uport->regshift;
817 * Free and release old regions
819 if (old_type != PORT_UNKNOWN)
820 uport->ops->release_port(uport);
822 uport->iobase = new_port;
823 uport->type = new_info->type;
824 uport->hub6 = new_info->hub6;
825 uport->iotype = new_info->io_type;
826 uport->regshift = new_info->iomem_reg_shift;
827 uport->mapbase = (unsigned long)new_info->iomem_base;
830 * Claim and map the new regions
832 if (uport->type != PORT_UNKNOWN) {
833 retval = uport->ops->request_port(uport);
834 } else {
835 /* Always success - Jean II */
836 retval = 0;
840 * If we fail to request resources for the
841 * new port, try to restore the old settings.
843 if (retval) {
844 uport->iobase = old_iobase;
845 uport->type = old_type;
846 uport->hub6 = old_hub6;
847 uport->iotype = old_iotype;
848 uport->regshift = old_shift;
849 uport->mapbase = old_mapbase;
851 if (old_type != PORT_UNKNOWN) {
852 retval = uport->ops->request_port(uport);
854 * If we failed to restore the old settings,
855 * we fail like this.
857 if (retval)
858 uport->type = PORT_UNKNOWN;
861 * We failed anyway.
863 retval = -EBUSY;
866 /* Added to return the correct error -Ram Gupta */
867 goto exit;
871 if (change_irq)
872 uport->irq = new_info->irq;
873 if (!(uport->flags & UPF_FIXED_PORT))
874 uport->uartclk = new_info->baud_base * 16;
875 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
876 (new_flags & UPF_CHANGE_MASK);
877 uport->custom_divisor = new_info->custom_divisor;
878 port->close_delay = close_delay;
879 port->closing_wait = closing_wait;
880 if (new_info->xmit_fifo_size)
881 uport->fifosize = new_info->xmit_fifo_size;
882 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
884 check_and_exit:
885 retval = 0;
886 if (uport->type == PORT_UNKNOWN)
887 goto exit;
888 if (port->flags & ASYNC_INITIALIZED) {
889 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
890 old_custom_divisor != uport->custom_divisor) {
892 * If they're setting up a custom divisor or speed,
893 * instead of clearing it, then bitch about it. No
894 * need to rate-limit; it's CAP_SYS_ADMIN only.
896 if (uport->flags & UPF_SPD_MASK) {
897 char buf[64];
899 dev_notice(uport->dev,
900 "%s sets custom speed on %s. This is deprecated.\n",
901 current->comm,
902 tty_name(port->tty, buf));
904 uart_change_speed(tty, state, NULL);
906 } else
907 retval = uart_startup(tty, state, 1);
908 exit:
909 return retval;
912 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
913 struct serial_struct __user *newinfo)
915 struct serial_struct new_serial;
916 struct tty_port *port = &state->port;
917 int retval;
919 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
920 return -EFAULT;
923 * This semaphore protects port->count. It is also
924 * very useful to prevent opens. Also, take the
925 * port configuration semaphore to make sure that a
926 * module insertion/removal doesn't change anything
927 * under us.
929 mutex_lock(&port->mutex);
930 retval = uart_set_info(tty, port, state, &new_serial);
931 mutex_unlock(&port->mutex);
932 return retval;
936 * uart_get_lsr_info - get line status register info
937 * @tty: tty associated with the UART
938 * @state: UART being queried
939 * @value: returned modem value
941 * Note: uart_ioctl protects us against hangups.
943 static int uart_get_lsr_info(struct tty_struct *tty,
944 struct uart_state *state, unsigned int __user *value)
946 struct uart_port *uport = state->uart_port;
947 unsigned int result;
949 result = uport->ops->tx_empty(uport);
952 * If we're about to load something into the transmit
953 * register, we'll pretend the transmitter isn't empty to
954 * avoid a race condition (depending on when the transmit
955 * interrupt happens).
957 if (uport->x_char ||
958 ((uart_circ_chars_pending(&state->xmit) > 0) &&
959 !uart_tx_stopped(uport)))
960 result &= ~TIOCSER_TEMT;
962 return put_user(result, value);
965 static int uart_tiocmget(struct tty_struct *tty)
967 struct uart_state *state = tty->driver_data;
968 struct tty_port *port = &state->port;
969 struct uart_port *uport = state->uart_port;
970 int result = -EIO;
972 mutex_lock(&port->mutex);
973 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
974 result = uport->mctrl;
975 spin_lock_irq(&uport->lock);
976 result |= uport->ops->get_mctrl(uport);
977 spin_unlock_irq(&uport->lock);
979 mutex_unlock(&port->mutex);
981 return result;
984 static int
985 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
987 struct uart_state *state = tty->driver_data;
988 struct uart_port *uport = state->uart_port;
989 struct tty_port *port = &state->port;
990 int ret = -EIO;
992 mutex_lock(&port->mutex);
993 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
994 uart_update_mctrl(uport, set, clear);
995 ret = 0;
997 mutex_unlock(&port->mutex);
998 return ret;
1001 static int uart_break_ctl(struct tty_struct *tty, int break_state)
1003 struct uart_state *state = tty->driver_data;
1004 struct tty_port *port = &state->port;
1005 struct uart_port *uport = state->uart_port;
1007 mutex_lock(&port->mutex);
1009 if (uport->type != PORT_UNKNOWN)
1010 uport->ops->break_ctl(uport, break_state);
1012 mutex_unlock(&port->mutex);
1013 return 0;
1016 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1018 struct uart_port *uport = state->uart_port;
1019 struct tty_port *port = &state->port;
1020 int flags, ret;
1022 if (!capable(CAP_SYS_ADMIN))
1023 return -EPERM;
1026 * Take the per-port semaphore. This prevents count from
1027 * changing, and hence any extra opens of the port while
1028 * we're auto-configuring.
1030 if (mutex_lock_interruptible(&port->mutex))
1031 return -ERESTARTSYS;
1033 ret = -EBUSY;
1034 if (tty_port_users(port) == 1) {
1035 uart_shutdown(tty, state);
1038 * If we already have a port type configured,
1039 * we must release its resources.
1041 if (uport->type != PORT_UNKNOWN)
1042 uport->ops->release_port(uport);
1044 flags = UART_CONFIG_TYPE;
1045 if (uport->flags & UPF_AUTO_IRQ)
1046 flags |= UART_CONFIG_IRQ;
1049 * This will claim the ports resources if
1050 * a port is found.
1052 uport->ops->config_port(uport, flags);
1054 ret = uart_startup(tty, state, 1);
1056 mutex_unlock(&port->mutex);
1057 return ret;
1060 static void uart_enable_ms(struct uart_port *uport)
1063 * Force modem status interrupts on
1065 if (uport->ops->enable_ms)
1066 uport->ops->enable_ms(uport);
1070 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1071 * - mask passed in arg for lines of interest
1072 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1073 * Caller should use TIOCGICOUNT to see which one it was
1075 * FIXME: This wants extracting into a common all driver implementation
1076 * of TIOCMWAIT using tty_port.
1078 static int
1079 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1081 struct uart_port *uport = state->uart_port;
1082 struct tty_port *port = &state->port;
1083 DECLARE_WAITQUEUE(wait, current);
1084 struct uart_icount cprev, cnow;
1085 int ret;
1088 * note the counters on entry
1090 spin_lock_irq(&uport->lock);
1091 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1092 uart_enable_ms(uport);
1093 spin_unlock_irq(&uport->lock);
1095 add_wait_queue(&port->delta_msr_wait, &wait);
1096 for (;;) {
1097 spin_lock_irq(&uport->lock);
1098 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1099 spin_unlock_irq(&uport->lock);
1101 set_current_state(TASK_INTERRUPTIBLE);
1103 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1104 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1105 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1106 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1107 ret = 0;
1108 break;
1111 schedule();
1113 /* see if a signal did it */
1114 if (signal_pending(current)) {
1115 ret = -ERESTARTSYS;
1116 break;
1119 cprev = cnow;
1121 __set_current_state(TASK_RUNNING);
1122 remove_wait_queue(&port->delta_msr_wait, &wait);
1124 return ret;
1128 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1129 * Return: write counters to the user passed counter struct
1130 * NB: both 1->0 and 0->1 transitions are counted except for
1131 * RI where only 0->1 is counted.
1133 static int uart_get_icount(struct tty_struct *tty,
1134 struct serial_icounter_struct *icount)
1136 struct uart_state *state = tty->driver_data;
1137 struct uart_icount cnow;
1138 struct uart_port *uport = state->uart_port;
1140 spin_lock_irq(&uport->lock);
1141 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1142 spin_unlock_irq(&uport->lock);
1144 icount->cts = cnow.cts;
1145 icount->dsr = cnow.dsr;
1146 icount->rng = cnow.rng;
1147 icount->dcd = cnow.dcd;
1148 icount->rx = cnow.rx;
1149 icount->tx = cnow.tx;
1150 icount->frame = cnow.frame;
1151 icount->overrun = cnow.overrun;
1152 icount->parity = cnow.parity;
1153 icount->brk = cnow.brk;
1154 icount->buf_overrun = cnow.buf_overrun;
1156 return 0;
1159 static int uart_get_rs485_config(struct uart_port *port,
1160 struct serial_rs485 __user *rs485)
1162 unsigned long flags;
1163 struct serial_rs485 aux;
1165 spin_lock_irqsave(&port->lock, flags);
1166 aux = port->rs485;
1167 spin_unlock_irqrestore(&port->lock, flags);
1169 if (copy_to_user(rs485, &aux, sizeof(aux)))
1170 return -EFAULT;
1172 return 0;
1175 static int uart_set_rs485_config(struct uart_port *port,
1176 struct serial_rs485 __user *rs485_user)
1178 struct serial_rs485 rs485;
1179 int ret;
1180 unsigned long flags;
1182 if (!port->rs485_config)
1183 return -ENOIOCTLCMD;
1185 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1186 return -EFAULT;
1188 spin_lock_irqsave(&port->lock, flags);
1189 ret = port->rs485_config(port, &rs485);
1190 spin_unlock_irqrestore(&port->lock, flags);
1191 if (ret)
1192 return ret;
1194 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1195 return -EFAULT;
1197 return 0;
1201 * Called via sys_ioctl. We can use spin_lock_irq() here.
1203 static int
1204 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1205 unsigned long arg)
1207 struct uart_state *state = tty->driver_data;
1208 struct tty_port *port = &state->port;
1209 void __user *uarg = (void __user *)arg;
1210 int ret = -ENOIOCTLCMD;
1214 * These ioctls don't rely on the hardware to be present.
1216 switch (cmd) {
1217 case TIOCGSERIAL:
1218 ret = uart_get_info_user(port, uarg);
1219 break;
1221 case TIOCSSERIAL:
1222 down_write(&tty->termios_rwsem);
1223 ret = uart_set_info_user(tty, state, uarg);
1224 up_write(&tty->termios_rwsem);
1225 break;
1227 case TIOCSERCONFIG:
1228 down_write(&tty->termios_rwsem);
1229 ret = uart_do_autoconfig(tty, state);
1230 up_write(&tty->termios_rwsem);
1231 break;
1233 case TIOCSERGWILD: /* obsolete */
1234 case TIOCSERSWILD: /* obsolete */
1235 ret = 0;
1236 break;
1239 if (ret != -ENOIOCTLCMD)
1240 goto out;
1242 if (tty->flags & (1 << TTY_IO_ERROR)) {
1243 ret = -EIO;
1244 goto out;
1248 * The following should only be used when hardware is present.
1250 switch (cmd) {
1251 case TIOCMIWAIT:
1252 ret = uart_wait_modem_status(state, arg);
1253 break;
1256 if (ret != -ENOIOCTLCMD)
1257 goto out;
1259 mutex_lock(&port->mutex);
1261 if (tty->flags & (1 << TTY_IO_ERROR)) {
1262 ret = -EIO;
1263 goto out_up;
1267 * All these rely on hardware being present and need to be
1268 * protected against the tty being hung up.
1271 switch (cmd) {
1272 case TIOCSERGETLSR: /* Get line status register */
1273 ret = uart_get_lsr_info(tty, state, uarg);
1274 break;
1276 case TIOCGRS485:
1277 ret = uart_get_rs485_config(state->uart_port, uarg);
1278 break;
1280 case TIOCSRS485:
1281 ret = uart_set_rs485_config(state->uart_port, uarg);
1282 break;
1283 default: {
1284 struct uart_port *uport = state->uart_port;
1285 if (uport->ops->ioctl)
1286 ret = uport->ops->ioctl(uport, cmd, arg);
1287 break;
1290 out_up:
1291 mutex_unlock(&port->mutex);
1292 out:
1293 return ret;
1296 static void uart_set_ldisc(struct tty_struct *tty)
1298 struct uart_state *state = tty->driver_data;
1299 struct uart_port *uport = state->uart_port;
1301 if (uport->ops->set_ldisc) {
1302 mutex_lock(&state->port.mutex);
1303 uport->ops->set_ldisc(uport, &tty->termios);
1304 mutex_unlock(&state->port.mutex);
1308 static void uart_set_termios(struct tty_struct *tty,
1309 struct ktermios *old_termios)
1311 struct uart_state *state = tty->driver_data;
1312 struct uart_port *uport = state->uart_port;
1313 unsigned int cflag = tty->termios.c_cflag;
1314 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1315 bool sw_changed = false;
1318 * Drivers doing software flow control also need to know
1319 * about changes to these input settings.
1321 if (uport->flags & UPF_SOFT_FLOW) {
1322 iflag_mask |= IXANY|IXON|IXOFF;
1323 sw_changed =
1324 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1325 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1329 * These are the bits that are used to setup various
1330 * flags in the low level driver. We can ignore the Bfoo
1331 * bits in c_cflag; c_[io]speed will always be set
1332 * appropriately by set_termios() in tty_ioctl.c
1334 if ((cflag ^ old_termios->c_cflag) == 0 &&
1335 tty->termios.c_ospeed == old_termios->c_ospeed &&
1336 tty->termios.c_ispeed == old_termios->c_ispeed &&
1337 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1338 !sw_changed) {
1339 return;
1342 mutex_lock(&state->port.mutex);
1343 uart_change_speed(tty, state, old_termios);
1344 mutex_unlock(&state->port.mutex);
1345 /* reload cflag from termios; port driver may have overriden flags */
1346 cflag = tty->termios.c_cflag;
1348 /* Handle transition to B0 status */
1349 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1350 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1351 /* Handle transition away from B0 status */
1352 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1353 unsigned int mask = TIOCM_DTR;
1354 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
1355 mask |= TIOCM_RTS;
1356 uart_set_mctrl(uport, mask);
1361 * Calls to uart_close() are serialised via the tty_lock in
1362 * drivers/tty/tty_io.c:tty_release()
1363 * drivers/tty/tty_io.c:do_tty_hangup()
1364 * This runs from a workqueue and can sleep for a _short_ time only.
1366 static void uart_close(struct tty_struct *tty, struct file *filp)
1368 struct uart_state *state = tty->driver_data;
1369 struct tty_port *port;
1370 struct uart_port *uport;
1371 unsigned long flags;
1373 if (!state) {
1374 struct uart_driver *drv = tty->driver->driver_state;
1376 state = drv->state + tty->index;
1377 port = &state->port;
1378 spin_lock_irq(&port->lock);
1379 --port->count;
1380 spin_unlock_irq(&port->lock);
1381 return;
1384 uport = state->uart_port;
1385 port = &state->port;
1387 pr_debug("uart_close(%d) called\n", uport ? uport->line : -1);
1389 if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1390 return;
1393 * At this point, we stop accepting input. To do this, we
1394 * disable the receive line status interrupts.
1396 if (port->flags & ASYNC_INITIALIZED) {
1397 unsigned long flags;
1398 spin_lock_irqsave(&uport->lock, flags);
1399 uport->ops->stop_rx(uport);
1400 spin_unlock_irqrestore(&uport->lock, flags);
1402 * Before we drop DTR, make sure the UART transmitter
1403 * has completely drained; this is especially
1404 * important if there is a transmit FIFO!
1406 uart_wait_until_sent(tty, uport->timeout);
1409 mutex_lock(&port->mutex);
1410 uart_shutdown(tty, state);
1411 tty_port_tty_set(port, NULL);
1413 spin_lock_irqsave(&port->lock, flags);
1415 if (port->blocked_open) {
1416 spin_unlock_irqrestore(&port->lock, flags);
1417 if (port->close_delay)
1418 msleep_interruptible(jiffies_to_msecs(port->close_delay));
1419 spin_lock_irqsave(&port->lock, flags);
1420 } else if (!uart_console(uport)) {
1421 spin_unlock_irqrestore(&port->lock, flags);
1422 uart_change_pm(state, UART_PM_STATE_OFF);
1423 spin_lock_irqsave(&port->lock, flags);
1427 * Wake up anyone trying to open this port.
1429 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1430 clear_bit(ASYNCB_CLOSING, &port->flags);
1431 spin_unlock_irqrestore(&port->lock, flags);
1432 wake_up_interruptible(&port->open_wait);
1433 wake_up_interruptible(&port->close_wait);
1435 mutex_unlock(&port->mutex);
1437 tty_ldisc_flush(tty);
1438 tty->closing = 0;
1441 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1443 struct uart_state *state = tty->driver_data;
1444 struct uart_port *port = state->uart_port;
1445 unsigned long char_time, expire;
1447 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1448 return;
1451 * Set the check interval to be 1/5 of the estimated time to
1452 * send a single character, and make it at least 1. The check
1453 * interval should also be less than the timeout.
1455 * Note: we have to use pretty tight timings here to satisfy
1456 * the NIST-PCTS.
1458 char_time = (port->timeout - HZ/50) / port->fifosize;
1459 char_time = char_time / 5;
1460 if (char_time == 0)
1461 char_time = 1;
1462 if (timeout && timeout < char_time)
1463 char_time = timeout;
1466 * If the transmitter hasn't cleared in twice the approximate
1467 * amount of time to send the entire FIFO, it probably won't
1468 * ever clear. This assumes the UART isn't doing flow
1469 * control, which is currently the case. Hence, if it ever
1470 * takes longer than port->timeout, this is probably due to a
1471 * UART bug of some kind. So, we clamp the timeout parameter at
1472 * 2*port->timeout.
1474 if (timeout == 0 || timeout > 2 * port->timeout)
1475 timeout = 2 * port->timeout;
1477 expire = jiffies + timeout;
1479 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1480 port->line, jiffies, expire);
1483 * Check whether the transmitter is empty every 'char_time'.
1484 * 'timeout' / 'expire' give us the maximum amount of time
1485 * we wait.
1487 while (!port->ops->tx_empty(port)) {
1488 msleep_interruptible(jiffies_to_msecs(char_time));
1489 if (signal_pending(current))
1490 break;
1491 if (time_after(jiffies, expire))
1492 break;
1497 * Calls to uart_hangup() are serialised by the tty_lock in
1498 * drivers/tty/tty_io.c:do_tty_hangup()
1499 * This runs from a workqueue and can sleep for a _short_ time only.
1501 static void uart_hangup(struct tty_struct *tty)
1503 struct uart_state *state = tty->driver_data;
1504 struct tty_port *port = &state->port;
1505 unsigned long flags;
1507 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1509 mutex_lock(&port->mutex);
1510 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1511 uart_flush_buffer(tty);
1512 uart_shutdown(tty, state);
1513 spin_lock_irqsave(&port->lock, flags);
1514 port->count = 0;
1515 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1516 spin_unlock_irqrestore(&port->lock, flags);
1517 tty_port_tty_set(port, NULL);
1518 if (!uart_console(state->uart_port))
1519 uart_change_pm(state, UART_PM_STATE_OFF);
1520 wake_up_interruptible(&port->open_wait);
1521 wake_up_interruptible(&port->delta_msr_wait);
1523 mutex_unlock(&port->mutex);
1526 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1528 return 0;
1531 static void uart_port_shutdown(struct tty_port *port)
1533 struct uart_state *state = container_of(port, struct uart_state, port);
1534 struct uart_port *uport = state->uart_port;
1537 * clear delta_msr_wait queue to avoid mem leaks: we may free
1538 * the irq here so the queue might never be woken up. Note
1539 * that we won't end up waiting on delta_msr_wait again since
1540 * any outstanding file descriptors should be pointing at
1541 * hung_up_tty_fops now.
1543 wake_up_interruptible(&port->delta_msr_wait);
1546 * Free the IRQ and disable the port.
1548 uport->ops->shutdown(uport);
1551 * Ensure that the IRQ handler isn't running on another CPU.
1553 synchronize_irq(uport->irq);
1556 static int uart_carrier_raised(struct tty_port *port)
1558 struct uart_state *state = container_of(port, struct uart_state, port);
1559 struct uart_port *uport = state->uart_port;
1560 int mctrl;
1561 spin_lock_irq(&uport->lock);
1562 uart_enable_ms(uport);
1563 mctrl = uport->ops->get_mctrl(uport);
1564 spin_unlock_irq(&uport->lock);
1565 if (mctrl & TIOCM_CAR)
1566 return 1;
1567 return 0;
1570 static void uart_dtr_rts(struct tty_port *port, int onoff)
1572 struct uart_state *state = container_of(port, struct uart_state, port);
1573 struct uart_port *uport = state->uart_port;
1575 if (onoff)
1576 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1577 else
1578 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1582 * Calls to uart_open are serialised by the tty_lock in
1583 * drivers/tty/tty_io.c:tty_open()
1584 * Note that if this fails, then uart_close() _will_ be called.
1586 * In time, we want to scrap the "opening nonpresent ports"
1587 * behaviour and implement an alternative way for setserial
1588 * to set base addresses/ports/types. This will allow us to
1589 * get rid of a certain amount of extra tests.
1591 static int uart_open(struct tty_struct *tty, struct file *filp)
1593 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1594 int retval, line = tty->index;
1595 struct uart_state *state = drv->state + line;
1596 struct tty_port *port = &state->port;
1598 pr_debug("uart_open(%d) called\n", line);
1600 spin_lock_irq(&port->lock);
1601 ++port->count;
1602 spin_unlock_irq(&port->lock);
1605 * We take the semaphore here to guarantee that we won't be re-entered
1606 * while allocating the state structure, or while we request any IRQs
1607 * that the driver may need. This also has the nice side-effect that
1608 * it delays the action of uart_hangup, so we can guarantee that
1609 * state->port.tty will always contain something reasonable.
1611 if (mutex_lock_interruptible(&port->mutex)) {
1612 retval = -ERESTARTSYS;
1613 goto end;
1616 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1617 retval = -ENXIO;
1618 goto err_unlock;
1621 tty->driver_data = state;
1622 state->uart_port->state = state;
1623 state->port.low_latency =
1624 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1625 tty_port_tty_set(port, tty);
1628 * Start up the serial port.
1630 retval = uart_startup(tty, state, 0);
1633 * If we succeeded, wait until the port is ready.
1635 mutex_unlock(&port->mutex);
1636 if (retval == 0)
1637 retval = tty_port_block_til_ready(port, tty, filp);
1639 end:
1640 return retval;
1641 err_unlock:
1642 mutex_unlock(&port->mutex);
1643 goto end;
1646 static const char *uart_type(struct uart_port *port)
1648 const char *str = NULL;
1650 if (port->ops->type)
1651 str = port->ops->type(port);
1653 if (!str)
1654 str = "unknown";
1656 return str;
1659 #ifdef CONFIG_PROC_FS
1661 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1663 struct uart_state *state = drv->state + i;
1664 struct tty_port *port = &state->port;
1665 enum uart_pm_state pm_state;
1666 struct uart_port *uport = state->uart_port;
1667 char stat_buf[32];
1668 unsigned int status;
1669 int mmio;
1671 if (!uport)
1672 return;
1674 mmio = uport->iotype >= UPIO_MEM;
1675 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1676 uport->line, uart_type(uport),
1677 mmio ? "mmio:0x" : "port:",
1678 mmio ? (unsigned long long)uport->mapbase
1679 : (unsigned long long)uport->iobase,
1680 uport->irq);
1682 if (uport->type == PORT_UNKNOWN) {
1683 seq_putc(m, '\n');
1684 return;
1687 if (capable(CAP_SYS_ADMIN)) {
1688 mutex_lock(&port->mutex);
1689 pm_state = state->pm_state;
1690 if (pm_state != UART_PM_STATE_ON)
1691 uart_change_pm(state, UART_PM_STATE_ON);
1692 spin_lock_irq(&uport->lock);
1693 status = uport->ops->get_mctrl(uport);
1694 spin_unlock_irq(&uport->lock);
1695 if (pm_state != UART_PM_STATE_ON)
1696 uart_change_pm(state, pm_state);
1697 mutex_unlock(&port->mutex);
1699 seq_printf(m, " tx:%d rx:%d",
1700 uport->icount.tx, uport->icount.rx);
1701 if (uport->icount.frame)
1702 seq_printf(m, " fe:%d",
1703 uport->icount.frame);
1704 if (uport->icount.parity)
1705 seq_printf(m, " pe:%d",
1706 uport->icount.parity);
1707 if (uport->icount.brk)
1708 seq_printf(m, " brk:%d",
1709 uport->icount.brk);
1710 if (uport->icount.overrun)
1711 seq_printf(m, " oe:%d",
1712 uport->icount.overrun);
1714 #define INFOBIT(bit, str) \
1715 if (uport->mctrl & (bit)) \
1716 strncat(stat_buf, (str), sizeof(stat_buf) - \
1717 strlen(stat_buf) - 2)
1718 #define STATBIT(bit, str) \
1719 if (status & (bit)) \
1720 strncat(stat_buf, (str), sizeof(stat_buf) - \
1721 strlen(stat_buf) - 2)
1723 stat_buf[0] = '\0';
1724 stat_buf[1] = '\0';
1725 INFOBIT(TIOCM_RTS, "|RTS");
1726 STATBIT(TIOCM_CTS, "|CTS");
1727 INFOBIT(TIOCM_DTR, "|DTR");
1728 STATBIT(TIOCM_DSR, "|DSR");
1729 STATBIT(TIOCM_CAR, "|CD");
1730 STATBIT(TIOCM_RNG, "|RI");
1731 if (stat_buf[0])
1732 stat_buf[0] = ' ';
1734 seq_puts(m, stat_buf);
1736 seq_putc(m, '\n');
1737 #undef STATBIT
1738 #undef INFOBIT
1741 static int uart_proc_show(struct seq_file *m, void *v)
1743 struct tty_driver *ttydrv = m->private;
1744 struct uart_driver *drv = ttydrv->driver_state;
1745 int i;
1747 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1748 "", "", "");
1749 for (i = 0; i < drv->nr; i++)
1750 uart_line_info(m, drv, i);
1751 return 0;
1754 static int uart_proc_open(struct inode *inode, struct file *file)
1756 return single_open(file, uart_proc_show, PDE_DATA(inode));
1759 static const struct file_operations uart_proc_fops = {
1760 .owner = THIS_MODULE,
1761 .open = uart_proc_open,
1762 .read = seq_read,
1763 .llseek = seq_lseek,
1764 .release = single_release,
1766 #endif
1768 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1770 * uart_console_write - write a console message to a serial port
1771 * @port: the port to write the message
1772 * @s: array of characters
1773 * @count: number of characters in string to write
1774 * @putchar: function to write character to port
1776 void uart_console_write(struct uart_port *port, const char *s,
1777 unsigned int count,
1778 void (*putchar)(struct uart_port *, int))
1780 unsigned int i;
1782 for (i = 0; i < count; i++, s++) {
1783 if (*s == '\n')
1784 putchar(port, '\r');
1785 putchar(port, *s);
1788 EXPORT_SYMBOL_GPL(uart_console_write);
1791 * Check whether an invalid uart number has been specified, and
1792 * if so, search for the first available port that does have
1793 * console support.
1795 struct uart_port * __init
1796 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1798 int idx = co->index;
1800 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1801 ports[idx].membase == NULL))
1802 for (idx = 0; idx < nr; idx++)
1803 if (ports[idx].iobase != 0 ||
1804 ports[idx].membase != NULL)
1805 break;
1807 co->index = idx;
1809 return ports + idx;
1813 * uart_parse_earlycon - Parse earlycon options
1814 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1815 * @iotype: ptr for decoded iotype (out)
1816 * @addr: ptr for decoded mapbase/iobase (out)
1817 * @options: ptr for <options> field; NULL if not present (out)
1819 * Decodes earlycon kernel command line parameters of the form
1820 * earlycon=<name>,io|mmio|mmio32,<addr>,<options>
1821 * console=<name>,io|mmio|mmio32,<addr>,<options>
1823 * The optional form
1824 * earlycon=<name>,0x<addr>,<options>
1825 * console=<name>,0x<addr>,<options>
1826 * is also accepted; the returned @iotype will be UPIO_MEM.
1828 * Returns 0 on success or -EINVAL on failure
1830 int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
1831 char **options)
1833 if (strncmp(p, "mmio,", 5) == 0) {
1834 *iotype = UPIO_MEM;
1835 p += 5;
1836 } else if (strncmp(p, "mmio32,", 7) == 0) {
1837 *iotype = UPIO_MEM32;
1838 p += 7;
1839 } else if (strncmp(p, "io,", 3) == 0) {
1840 *iotype = UPIO_PORT;
1841 p += 3;
1842 } else if (strncmp(p, "0x", 2) == 0) {
1843 *iotype = UPIO_MEM;
1844 } else {
1845 return -EINVAL;
1848 *addr = simple_strtoul(p, NULL, 0);
1849 p = strchr(p, ',');
1850 if (p)
1851 p++;
1853 *options = p;
1854 return 0;
1856 EXPORT_SYMBOL_GPL(uart_parse_earlycon);
1859 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1860 * @options: pointer to option string
1861 * @baud: pointer to an 'int' variable for the baud rate.
1862 * @parity: pointer to an 'int' variable for the parity.
1863 * @bits: pointer to an 'int' variable for the number of data bits.
1864 * @flow: pointer to an 'int' variable for the flow control character.
1866 * uart_parse_options decodes a string containing the serial console
1867 * options. The format of the string is <baud><parity><bits><flow>,
1868 * eg: 115200n8r
1870 void
1871 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1873 char *s = options;
1875 *baud = simple_strtoul(s, NULL, 10);
1876 while (*s >= '0' && *s <= '9')
1877 s++;
1878 if (*s)
1879 *parity = *s++;
1880 if (*s)
1881 *bits = *s++ - '0';
1882 if (*s)
1883 *flow = *s;
1885 EXPORT_SYMBOL_GPL(uart_parse_options);
1887 struct baud_rates {
1888 unsigned int rate;
1889 unsigned int cflag;
1892 static const struct baud_rates baud_rates[] = {
1893 { 921600, B921600 },
1894 { 460800, B460800 },
1895 { 230400, B230400 },
1896 { 115200, B115200 },
1897 { 57600, B57600 },
1898 { 38400, B38400 },
1899 { 19200, B19200 },
1900 { 9600, B9600 },
1901 { 4800, B4800 },
1902 { 2400, B2400 },
1903 { 1200, B1200 },
1904 { 0, B38400 }
1908 * uart_set_options - setup the serial console parameters
1909 * @port: pointer to the serial ports uart_port structure
1910 * @co: console pointer
1911 * @baud: baud rate
1912 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1913 * @bits: number of data bits
1914 * @flow: flow control character - 'r' (rts)
1917 uart_set_options(struct uart_port *port, struct console *co,
1918 int baud, int parity, int bits, int flow)
1920 struct ktermios termios;
1921 static struct ktermios dummy;
1922 int i;
1925 * Ensure that the serial console lock is initialised
1926 * early.
1927 * If this port is a console, then the spinlock is already
1928 * initialised.
1930 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1931 spin_lock_init(&port->lock);
1932 lockdep_set_class(&port->lock, &port_lock_key);
1935 memset(&termios, 0, sizeof(struct ktermios));
1937 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1940 * Construct a cflag setting.
1942 for (i = 0; baud_rates[i].rate; i++)
1943 if (baud_rates[i].rate <= baud)
1944 break;
1946 termios.c_cflag |= baud_rates[i].cflag;
1948 if (bits == 7)
1949 termios.c_cflag |= CS7;
1950 else
1951 termios.c_cflag |= CS8;
1953 switch (parity) {
1954 case 'o': case 'O':
1955 termios.c_cflag |= PARODD;
1956 /*fall through*/
1957 case 'e': case 'E':
1958 termios.c_cflag |= PARENB;
1959 break;
1962 if (flow == 'r')
1963 termios.c_cflag |= CRTSCTS;
1966 * some uarts on other side don't support no flow control.
1967 * So we set * DTR in host uart to make them happy
1969 port->mctrl |= TIOCM_DTR;
1971 port->ops->set_termios(port, &termios, &dummy);
1973 * Allow the setting of the UART parameters with a NULL console
1974 * too:
1976 if (co)
1977 co->cflag = termios.c_cflag;
1979 return 0;
1981 EXPORT_SYMBOL_GPL(uart_set_options);
1982 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1985 * uart_change_pm - set power state of the port
1987 * @state: port descriptor
1988 * @pm_state: new state
1990 * Locking: port->mutex has to be held
1992 static void uart_change_pm(struct uart_state *state,
1993 enum uart_pm_state pm_state)
1995 struct uart_port *port = state->uart_port;
1997 if (state->pm_state != pm_state) {
1998 if (port->ops->pm)
1999 port->ops->pm(port, pm_state, state->pm_state);
2000 state->pm_state = pm_state;
2004 struct uart_match {
2005 struct uart_port *port;
2006 struct uart_driver *driver;
2009 static int serial_match_port(struct device *dev, void *data)
2011 struct uart_match *match = data;
2012 struct tty_driver *tty_drv = match->driver->tty_driver;
2013 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
2014 match->port->line;
2016 return dev->devt == devt; /* Actually, only one tty per port */
2019 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
2021 struct uart_state *state = drv->state + uport->line;
2022 struct tty_port *port = &state->port;
2023 struct device *tty_dev;
2024 struct uart_match match = {uport, drv};
2026 mutex_lock(&port->mutex);
2028 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2029 if (device_may_wakeup(tty_dev)) {
2030 if (!enable_irq_wake(uport->irq))
2031 uport->irq_wake = 1;
2032 put_device(tty_dev);
2033 mutex_unlock(&port->mutex);
2034 return 0;
2036 put_device(tty_dev);
2038 /* Nothing to do if the console is not suspending */
2039 if (!console_suspend_enabled && uart_console(uport))
2040 goto unlock;
2042 uport->suspended = 1;
2044 if (port->flags & ASYNC_INITIALIZED) {
2045 const struct uart_ops *ops = uport->ops;
2046 int tries;
2048 set_bit(ASYNCB_SUSPENDED, &port->flags);
2049 clear_bit(ASYNCB_INITIALIZED, &port->flags);
2051 spin_lock_irq(&uport->lock);
2052 ops->stop_tx(uport);
2053 ops->set_mctrl(uport, 0);
2054 ops->stop_rx(uport);
2055 spin_unlock_irq(&uport->lock);
2058 * Wait for the transmitter to empty.
2060 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2061 msleep(10);
2062 if (!tries)
2063 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
2064 drv->dev_name,
2065 drv->tty_driver->name_base + uport->line);
2067 ops->shutdown(uport);
2071 * Disable the console device before suspending.
2073 if (uart_console(uport))
2074 console_stop(uport->cons);
2076 uart_change_pm(state, UART_PM_STATE_OFF);
2077 unlock:
2078 mutex_unlock(&port->mutex);
2080 return 0;
2083 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2085 struct uart_state *state = drv->state + uport->line;
2086 struct tty_port *port = &state->port;
2087 struct device *tty_dev;
2088 struct uart_match match = {uport, drv};
2089 struct ktermios termios;
2091 mutex_lock(&port->mutex);
2093 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2094 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2095 if (uport->irq_wake) {
2096 disable_irq_wake(uport->irq);
2097 uport->irq_wake = 0;
2099 put_device(tty_dev);
2100 mutex_unlock(&port->mutex);
2101 return 0;
2103 put_device(tty_dev);
2104 uport->suspended = 0;
2107 * Re-enable the console device after suspending.
2109 if (uart_console(uport)) {
2111 * First try to use the console cflag setting.
2113 memset(&termios, 0, sizeof(struct ktermios));
2114 termios.c_cflag = uport->cons->cflag;
2117 * If that's unset, use the tty termios setting.
2119 if (port->tty && termios.c_cflag == 0)
2120 termios = port->tty->termios;
2122 if (console_suspend_enabled)
2123 uart_change_pm(state, UART_PM_STATE_ON);
2124 uport->ops->set_termios(uport, &termios, NULL);
2125 if (console_suspend_enabled)
2126 console_start(uport->cons);
2129 if (port->flags & ASYNC_SUSPENDED) {
2130 const struct uart_ops *ops = uport->ops;
2131 int ret;
2133 uart_change_pm(state, UART_PM_STATE_ON);
2134 spin_lock_irq(&uport->lock);
2135 ops->set_mctrl(uport, 0);
2136 spin_unlock_irq(&uport->lock);
2137 if (console_suspend_enabled || !uart_console(uport)) {
2138 /* Protected by port mutex for now */
2139 struct tty_struct *tty = port->tty;
2140 ret = ops->startup(uport);
2141 if (ret == 0) {
2142 if (tty)
2143 uart_change_speed(tty, state, NULL);
2144 spin_lock_irq(&uport->lock);
2145 ops->set_mctrl(uport, uport->mctrl);
2146 ops->start_tx(uport);
2147 spin_unlock_irq(&uport->lock);
2148 set_bit(ASYNCB_INITIALIZED, &port->flags);
2149 } else {
2151 * Failed to resume - maybe hardware went away?
2152 * Clear the "initialized" flag so we won't try
2153 * to call the low level drivers shutdown method.
2155 uart_shutdown(tty, state);
2159 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2162 mutex_unlock(&port->mutex);
2164 return 0;
2167 static inline void
2168 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2170 char address[64];
2172 switch (port->iotype) {
2173 case UPIO_PORT:
2174 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2175 break;
2176 case UPIO_HUB6:
2177 snprintf(address, sizeof(address),
2178 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2179 break;
2180 case UPIO_MEM:
2181 case UPIO_MEM32:
2182 case UPIO_MEM32BE:
2183 case UPIO_AU:
2184 case UPIO_TSI:
2185 snprintf(address, sizeof(address),
2186 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2187 break;
2188 default:
2189 strlcpy(address, "*unknown*", sizeof(address));
2190 break;
2193 printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2194 port->dev ? dev_name(port->dev) : "",
2195 port->dev ? ": " : "",
2196 drv->dev_name,
2197 drv->tty_driver->name_base + port->line,
2198 address, port->irq, port->uartclk / 16, uart_type(port));
2201 static void
2202 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2203 struct uart_port *port)
2205 unsigned int flags;
2208 * If there isn't a port here, don't do anything further.
2210 if (!port->iobase && !port->mapbase && !port->membase)
2211 return;
2214 * Now do the auto configuration stuff. Note that config_port
2215 * is expected to claim the resources and map the port for us.
2217 flags = 0;
2218 if (port->flags & UPF_AUTO_IRQ)
2219 flags |= UART_CONFIG_IRQ;
2220 if (port->flags & UPF_BOOT_AUTOCONF) {
2221 if (!(port->flags & UPF_FIXED_TYPE)) {
2222 port->type = PORT_UNKNOWN;
2223 flags |= UART_CONFIG_TYPE;
2225 port->ops->config_port(port, flags);
2228 if (port->type != PORT_UNKNOWN) {
2229 unsigned long flags;
2231 uart_report_port(drv, port);
2233 /* Power up port for set_mctrl() */
2234 uart_change_pm(state, UART_PM_STATE_ON);
2237 * Ensure that the modem control lines are de-activated.
2238 * keep the DTR setting that is set in uart_set_options()
2239 * We probably don't need a spinlock around this, but
2241 spin_lock_irqsave(&port->lock, flags);
2242 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2243 spin_unlock_irqrestore(&port->lock, flags);
2246 * If this driver supports console, and it hasn't been
2247 * successfully registered yet, try to re-register it.
2248 * It may be that the port was not available.
2250 if (port->cons && !(port->cons->flags & CON_ENABLED))
2251 register_console(port->cons);
2254 * Power down all ports by default, except the
2255 * console if we have one.
2257 if (!uart_console(port))
2258 uart_change_pm(state, UART_PM_STATE_OFF);
2262 #ifdef CONFIG_CONSOLE_POLL
2264 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2266 struct uart_driver *drv = driver->driver_state;
2267 struct uart_state *state = drv->state + line;
2268 struct uart_port *port;
2269 int baud = 9600;
2270 int bits = 8;
2271 int parity = 'n';
2272 int flow = 'n';
2273 int ret;
2275 if (!state || !state->uart_port)
2276 return -1;
2278 port = state->uart_port;
2279 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2280 return -1;
2282 if (port->ops->poll_init) {
2283 struct tty_port *tport = &state->port;
2285 ret = 0;
2286 mutex_lock(&tport->mutex);
2288 * We don't set ASYNCB_INITIALIZED as we only initialized the
2289 * hw, e.g. state->xmit is still uninitialized.
2291 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2292 ret = port->ops->poll_init(port);
2293 mutex_unlock(&tport->mutex);
2294 if (ret)
2295 return ret;
2298 if (options) {
2299 uart_parse_options(options, &baud, &parity, &bits, &flow);
2300 return uart_set_options(port, NULL, baud, parity, bits, flow);
2303 return 0;
2306 static int uart_poll_get_char(struct tty_driver *driver, int line)
2308 struct uart_driver *drv = driver->driver_state;
2309 struct uart_state *state = drv->state + line;
2310 struct uart_port *port;
2312 if (!state || !state->uart_port)
2313 return -1;
2315 port = state->uart_port;
2316 return port->ops->poll_get_char(port);
2319 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2321 struct uart_driver *drv = driver->driver_state;
2322 struct uart_state *state = drv->state + line;
2323 struct uart_port *port;
2325 if (!state || !state->uart_port)
2326 return;
2328 port = state->uart_port;
2330 if (ch == '\n')
2331 port->ops->poll_put_char(port, '\r');
2332 port->ops->poll_put_char(port, ch);
2334 #endif
2336 static const struct tty_operations uart_ops = {
2337 .open = uart_open,
2338 .close = uart_close,
2339 .write = uart_write,
2340 .put_char = uart_put_char,
2341 .flush_chars = uart_flush_chars,
2342 .write_room = uart_write_room,
2343 .chars_in_buffer= uart_chars_in_buffer,
2344 .flush_buffer = uart_flush_buffer,
2345 .ioctl = uart_ioctl,
2346 .throttle = uart_throttle,
2347 .unthrottle = uart_unthrottle,
2348 .send_xchar = uart_send_xchar,
2349 .set_termios = uart_set_termios,
2350 .set_ldisc = uart_set_ldisc,
2351 .stop = uart_stop,
2352 .start = uart_start,
2353 .hangup = uart_hangup,
2354 .break_ctl = uart_break_ctl,
2355 .wait_until_sent= uart_wait_until_sent,
2356 #ifdef CONFIG_PROC_FS
2357 .proc_fops = &uart_proc_fops,
2358 #endif
2359 .tiocmget = uart_tiocmget,
2360 .tiocmset = uart_tiocmset,
2361 .get_icount = uart_get_icount,
2362 #ifdef CONFIG_CONSOLE_POLL
2363 .poll_init = uart_poll_init,
2364 .poll_get_char = uart_poll_get_char,
2365 .poll_put_char = uart_poll_put_char,
2366 #endif
2369 static const struct tty_port_operations uart_port_ops = {
2370 .activate = uart_port_activate,
2371 .shutdown = uart_port_shutdown,
2372 .carrier_raised = uart_carrier_raised,
2373 .dtr_rts = uart_dtr_rts,
2377 * uart_register_driver - register a driver with the uart core layer
2378 * @drv: low level driver structure
2380 * Register a uart driver with the core driver. We in turn register
2381 * with the tty layer, and initialise the core driver per-port state.
2383 * We have a proc file in /proc/tty/driver which is named after the
2384 * normal driver.
2386 * drv->port should be NULL, and the per-port structures should be
2387 * registered using uart_add_one_port after this call has succeeded.
2389 int uart_register_driver(struct uart_driver *drv)
2391 struct tty_driver *normal;
2392 int i, retval;
2394 BUG_ON(drv->state);
2397 * Maybe we should be using a slab cache for this, especially if
2398 * we have a large number of ports to handle.
2400 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2401 if (!drv->state)
2402 goto out;
2404 normal = alloc_tty_driver(drv->nr);
2405 if (!normal)
2406 goto out_kfree;
2408 drv->tty_driver = normal;
2410 normal->driver_name = drv->driver_name;
2411 normal->name = drv->dev_name;
2412 normal->major = drv->major;
2413 normal->minor_start = drv->minor;
2414 normal->type = TTY_DRIVER_TYPE_SERIAL;
2415 normal->subtype = SERIAL_TYPE_NORMAL;
2416 normal->init_termios = tty_std_termios;
2417 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2418 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2419 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2420 normal->driver_state = drv;
2421 tty_set_operations(normal, &uart_ops);
2424 * Initialise the UART state(s).
2426 for (i = 0; i < drv->nr; i++) {
2427 struct uart_state *state = drv->state + i;
2428 struct tty_port *port = &state->port;
2430 tty_port_init(port);
2431 port->ops = &uart_port_ops;
2434 retval = tty_register_driver(normal);
2435 if (retval >= 0)
2436 return retval;
2438 for (i = 0; i < drv->nr; i++)
2439 tty_port_destroy(&drv->state[i].port);
2440 put_tty_driver(normal);
2441 out_kfree:
2442 kfree(drv->state);
2443 out:
2444 return -ENOMEM;
2448 * uart_unregister_driver - remove a driver from the uart core layer
2449 * @drv: low level driver structure
2451 * Remove all references to a driver from the core driver. The low
2452 * level driver must have removed all its ports via the
2453 * uart_remove_one_port() if it registered them with uart_add_one_port().
2454 * (ie, drv->port == NULL)
2456 void uart_unregister_driver(struct uart_driver *drv)
2458 struct tty_driver *p = drv->tty_driver;
2459 unsigned int i;
2461 tty_unregister_driver(p);
2462 put_tty_driver(p);
2463 for (i = 0; i < drv->nr; i++)
2464 tty_port_destroy(&drv->state[i].port);
2465 kfree(drv->state);
2466 drv->state = NULL;
2467 drv->tty_driver = NULL;
2470 struct tty_driver *uart_console_device(struct console *co, int *index)
2472 struct uart_driver *p = co->data;
2473 *index = co->index;
2474 return p->tty_driver;
2477 static ssize_t uart_get_attr_uartclk(struct device *dev,
2478 struct device_attribute *attr, char *buf)
2480 struct serial_struct tmp;
2481 struct tty_port *port = dev_get_drvdata(dev);
2483 uart_get_info(port, &tmp);
2484 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2487 static ssize_t uart_get_attr_type(struct device *dev,
2488 struct device_attribute *attr, char *buf)
2490 struct serial_struct tmp;
2491 struct tty_port *port = dev_get_drvdata(dev);
2493 uart_get_info(port, &tmp);
2494 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2496 static ssize_t uart_get_attr_line(struct device *dev,
2497 struct device_attribute *attr, char *buf)
2499 struct serial_struct tmp;
2500 struct tty_port *port = dev_get_drvdata(dev);
2502 uart_get_info(port, &tmp);
2503 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2506 static ssize_t uart_get_attr_port(struct device *dev,
2507 struct device_attribute *attr, char *buf)
2509 struct serial_struct tmp;
2510 struct tty_port *port = dev_get_drvdata(dev);
2511 unsigned long ioaddr;
2513 uart_get_info(port, &tmp);
2514 ioaddr = tmp.port;
2515 if (HIGH_BITS_OFFSET)
2516 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2517 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2520 static ssize_t uart_get_attr_irq(struct device *dev,
2521 struct device_attribute *attr, char *buf)
2523 struct serial_struct tmp;
2524 struct tty_port *port = dev_get_drvdata(dev);
2526 uart_get_info(port, &tmp);
2527 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2530 static ssize_t uart_get_attr_flags(struct device *dev,
2531 struct device_attribute *attr, char *buf)
2533 struct serial_struct tmp;
2534 struct tty_port *port = dev_get_drvdata(dev);
2536 uart_get_info(port, &tmp);
2537 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2540 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2541 struct device_attribute *attr, char *buf)
2543 struct serial_struct tmp;
2544 struct tty_port *port = dev_get_drvdata(dev);
2546 uart_get_info(port, &tmp);
2547 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2551 static ssize_t uart_get_attr_close_delay(struct device *dev,
2552 struct device_attribute *attr, char *buf)
2554 struct serial_struct tmp;
2555 struct tty_port *port = dev_get_drvdata(dev);
2557 uart_get_info(port, &tmp);
2558 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2562 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2563 struct device_attribute *attr, char *buf)
2565 struct serial_struct tmp;
2566 struct tty_port *port = dev_get_drvdata(dev);
2568 uart_get_info(port, &tmp);
2569 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2572 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2573 struct device_attribute *attr, char *buf)
2575 struct serial_struct tmp;
2576 struct tty_port *port = dev_get_drvdata(dev);
2578 uart_get_info(port, &tmp);
2579 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2582 static ssize_t uart_get_attr_io_type(struct device *dev,
2583 struct device_attribute *attr, char *buf)
2585 struct serial_struct tmp;
2586 struct tty_port *port = dev_get_drvdata(dev);
2588 uart_get_info(port, &tmp);
2589 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2592 static ssize_t uart_get_attr_iomem_base(struct device *dev,
2593 struct device_attribute *attr, char *buf)
2595 struct serial_struct tmp;
2596 struct tty_port *port = dev_get_drvdata(dev);
2598 uart_get_info(port, &tmp);
2599 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2602 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2603 struct device_attribute *attr, char *buf)
2605 struct serial_struct tmp;
2606 struct tty_port *port = dev_get_drvdata(dev);
2608 uart_get_info(port, &tmp);
2609 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2612 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2613 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2614 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2615 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2616 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2617 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2618 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2619 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2620 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2621 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2622 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2623 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2624 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2626 static struct attribute *tty_dev_attrs[] = {
2627 &dev_attr_type.attr,
2628 &dev_attr_line.attr,
2629 &dev_attr_port.attr,
2630 &dev_attr_irq.attr,
2631 &dev_attr_flags.attr,
2632 &dev_attr_xmit_fifo_size.attr,
2633 &dev_attr_uartclk.attr,
2634 &dev_attr_close_delay.attr,
2635 &dev_attr_closing_wait.attr,
2636 &dev_attr_custom_divisor.attr,
2637 &dev_attr_io_type.attr,
2638 &dev_attr_iomem_base.attr,
2639 &dev_attr_iomem_reg_shift.attr,
2640 NULL,
2643 static const struct attribute_group tty_dev_attr_group = {
2644 .attrs = tty_dev_attrs,
2648 * uart_add_one_port - attach a driver-defined port structure
2649 * @drv: pointer to the uart low level driver structure for this port
2650 * @uport: uart port structure to use for this port.
2652 * This allows the driver to register its own uart_port structure
2653 * with the core driver. The main purpose is to allow the low
2654 * level uart drivers to expand uart_port, rather than having yet
2655 * more levels of structures.
2657 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2659 struct uart_state *state;
2660 struct tty_port *port;
2661 int ret = 0;
2662 struct device *tty_dev;
2663 int num_groups;
2665 BUG_ON(in_interrupt());
2667 if (uport->line >= drv->nr)
2668 return -EINVAL;
2670 state = drv->state + uport->line;
2671 port = &state->port;
2673 mutex_lock(&port_mutex);
2674 mutex_lock(&port->mutex);
2675 if (state->uart_port) {
2676 ret = -EINVAL;
2677 goto out;
2680 /* Link the port to the driver state table and vice versa */
2681 state->uart_port = uport;
2682 uport->state = state;
2684 state->pm_state = UART_PM_STATE_UNDEFINED;
2685 uport->cons = drv->cons;
2686 uport->minor = drv->tty_driver->minor_start + uport->line;
2689 * If this port is a console, then the spinlock is already
2690 * initialised.
2692 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2693 spin_lock_init(&uport->lock);
2694 lockdep_set_class(&uport->lock, &port_lock_key);
2696 if (uport->cons && uport->dev)
2697 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2699 uart_configure_port(drv, state, uport);
2701 num_groups = 2;
2702 if (uport->attr_group)
2703 num_groups++;
2705 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2706 GFP_KERNEL);
2707 if (!uport->tty_groups) {
2708 ret = -ENOMEM;
2709 goto out;
2711 uport->tty_groups[0] = &tty_dev_attr_group;
2712 if (uport->attr_group)
2713 uport->tty_groups[1] = uport->attr_group;
2716 * Register the port whether it's detected or not. This allows
2717 * setserial to be used to alter this port's parameters.
2719 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2720 uport->line, uport->dev, port, uport->tty_groups);
2721 if (likely(!IS_ERR(tty_dev))) {
2722 device_set_wakeup_capable(tty_dev, 1);
2723 } else {
2724 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2725 uport->line);
2729 * Ensure UPF_DEAD is not set.
2731 uport->flags &= ~UPF_DEAD;
2733 out:
2734 mutex_unlock(&port->mutex);
2735 mutex_unlock(&port_mutex);
2737 return ret;
2741 * uart_remove_one_port - detach a driver defined port structure
2742 * @drv: pointer to the uart low level driver structure for this port
2743 * @uport: uart port structure for this port
2745 * This unhooks (and hangs up) the specified port structure from the
2746 * core driver. No further calls will be made to the low-level code
2747 * for this port.
2749 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2751 struct uart_state *state = drv->state + uport->line;
2752 struct tty_port *port = &state->port;
2753 struct tty_struct *tty;
2754 int ret = 0;
2756 BUG_ON(in_interrupt());
2758 if (state->uart_port != uport)
2759 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2760 state->uart_port, uport);
2762 mutex_lock(&port_mutex);
2765 * Mark the port "dead" - this prevents any opens from
2766 * succeeding while we shut down the port.
2768 mutex_lock(&port->mutex);
2769 if (!state->uart_port) {
2770 mutex_unlock(&port->mutex);
2771 ret = -EINVAL;
2772 goto out;
2774 uport->flags |= UPF_DEAD;
2775 mutex_unlock(&port->mutex);
2778 * Remove the devices from the tty layer
2780 tty_unregister_device(drv->tty_driver, uport->line);
2782 tty = tty_port_tty_get(port);
2783 if (tty) {
2784 tty_vhangup(port->tty);
2785 tty_kref_put(tty);
2789 * If the port is used as a console, unregister it
2791 if (uart_console(uport))
2792 unregister_console(uport->cons);
2795 * Free the port IO and memory resources, if any.
2797 if (uport->type != PORT_UNKNOWN)
2798 uport->ops->release_port(uport);
2799 kfree(uport->tty_groups);
2802 * Indicate that there isn't a port here anymore.
2804 uport->type = PORT_UNKNOWN;
2806 state->uart_port = NULL;
2807 out:
2808 mutex_unlock(&port_mutex);
2810 return ret;
2814 * Are the two ports equivalent?
2816 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2818 if (port1->iotype != port2->iotype)
2819 return 0;
2821 switch (port1->iotype) {
2822 case UPIO_PORT:
2823 return (port1->iobase == port2->iobase);
2824 case UPIO_HUB6:
2825 return (port1->iobase == port2->iobase) &&
2826 (port1->hub6 == port2->hub6);
2827 case UPIO_MEM:
2828 case UPIO_MEM32:
2829 case UPIO_MEM32BE:
2830 case UPIO_AU:
2831 case UPIO_TSI:
2832 return (port1->mapbase == port2->mapbase);
2834 return 0;
2836 EXPORT_SYMBOL(uart_match_port);
2839 * uart_handle_dcd_change - handle a change of carrier detect state
2840 * @uport: uart_port structure for the open port
2841 * @status: new carrier detect status, nonzero if active
2843 * Caller must hold uport->lock
2845 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2847 struct tty_port *port = &uport->state->port;
2848 struct tty_struct *tty = port->tty;
2849 struct tty_ldisc *ld;
2851 lockdep_assert_held_once(&uport->lock);
2853 if (tty) {
2854 ld = tty_ldisc_ref(tty);
2855 if (ld) {
2856 if (ld->ops->dcd_change)
2857 ld->ops->dcd_change(tty, status);
2858 tty_ldisc_deref(ld);
2862 uport->icount.dcd++;
2864 if (uart_dcd_enabled(uport)) {
2865 if (status)
2866 wake_up_interruptible(&port->open_wait);
2867 else if (tty)
2868 tty_hangup(tty);
2871 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2874 * uart_handle_cts_change - handle a change of clear-to-send state
2875 * @uport: uart_port structure for the open port
2876 * @status: new clear to send status, nonzero if active
2878 * Caller must hold uport->lock
2880 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2882 lockdep_assert_held_once(&uport->lock);
2884 uport->icount.cts++;
2886 if (uart_softcts_mode(uport)) {
2887 if (uport->hw_stopped) {
2888 if (status) {
2889 uport->hw_stopped = 0;
2890 uport->ops->start_tx(uport);
2891 uart_write_wakeup(uport);
2893 } else {
2894 if (!status) {
2895 uport->hw_stopped = 1;
2896 uport->ops->stop_tx(uport);
2902 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2905 * uart_insert_char - push a char to the uart layer
2907 * User is responsible to call tty_flip_buffer_push when they are done with
2908 * insertion.
2910 * @port: corresponding port
2911 * @status: state of the serial port RX buffer (LSR for 8250)
2912 * @overrun: mask of overrun bits in @status
2913 * @ch: character to push
2914 * @flag: flag for the character (see TTY_NORMAL and friends)
2916 void uart_insert_char(struct uart_port *port, unsigned int status,
2917 unsigned int overrun, unsigned int ch, unsigned int flag)
2919 struct tty_port *tport = &port->state->port;
2921 if ((status & port->ignore_status_mask & ~overrun) == 0)
2922 if (tty_insert_flip_char(tport, ch, flag) == 0)
2923 ++port->icount.buf_overrun;
2926 * Overrun is special. Since it's reported immediately,
2927 * it doesn't affect the current character.
2929 if (status & ~port->ignore_status_mask & overrun)
2930 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2931 ++port->icount.buf_overrun;
2933 EXPORT_SYMBOL_GPL(uart_insert_char);
2935 EXPORT_SYMBOL(uart_write_wakeup);
2936 EXPORT_SYMBOL(uart_register_driver);
2937 EXPORT_SYMBOL(uart_unregister_driver);
2938 EXPORT_SYMBOL(uart_suspend_port);
2939 EXPORT_SYMBOL(uart_resume_port);
2940 EXPORT_SYMBOL(uart_add_one_port);
2941 EXPORT_SYMBOL(uart_remove_one_port);
2943 MODULE_DESCRIPTION("Serial driver core");
2944 MODULE_LICENSE("GPL");