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>
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>
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.
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;
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;
108 spin_lock_irqsave(&port->lock, flags);
110 spin_unlock_irqrestore(&port->lock, flags);
114 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
119 spin_lock_irqsave(&port->lock, flags);
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,
137 struct uart_port *uport = state->uart_port;
141 if (uport->type == PORT_UNKNOWN)
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
153 if (!state->xmit.buf) {
154 /* This is protected by the per port mutex */
155 page = get_zeroed_page(GFP_KERNEL);
159 state->xmit.buf = (unsigned char *) page;
160 uart_circ_clear(&state->xmit);
163 retval = uport->ops->startup(uport);
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);
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
189 if (retval && capable(CAP_SYS_ADMIN))
195 static int uart_startup(struct tty_struct *tty, struct uart_state *state,
198 struct tty_port *port = &state->port;
201 if (port->flags & ASYNC_INITIALIZED)
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);
212 set_bit(ASYNCB_INITIALIZED, &port->flags);
213 clear_bit(TTY_IO_ERROR, &tty->flags);
214 } else if (retval > 0)
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
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.
275 uart_update_timeout(struct uart_port *port, unsigned int cflag,
280 /* byte size and parity */
281 switch (cflag & CSIZE) {
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").
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;
340 upf_t flags = port->flags & UPF_SPD_MASK;
342 if (flags == UPF_SPD_HI)
344 else if (flags == UPF_SPD_VHI)
346 else if (flags == UPF_SPD_SHI)
348 else if (flags == UPF_SPD_WARP)
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...
358 if (try == 0 && baud == 38400)
362 * Special case: B0 rate.
369 if (baud >= min && baud <= max)
373 * Oops, the quotient was zero. Try again with
374 * the old baud rate if possible.
376 termios->c_cflag &= ~CBAUD;
378 baud = tty_termios_baud_rate(old);
380 tty_termios_encode_baud_rate(termios,
387 * As a last resort, if the range cannot be met then clip to
388 * the nearest chip supported rate.
392 tty_termios_encode_baud_rate(termios,
395 tty_termios_encode_baud_rate(termios,
399 /* Should never happen */
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.
414 uart_get_divisor(struct uart_port *port, unsigned int baud)
419 * Old custom speed handling.
421 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
422 quot = port->custom_divisor;
424 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
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;
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)
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;
456 uport->status &= ~UPSTAT_CTS_ENABLE;
458 if (termios->c_cflag & CLOCAL)
459 uport->status &= ~UPSTAT_DCD_ENABLE;
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) {
469 uport->ops->stop_tx(uport);
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)
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);
492 spin_unlock_irqrestore(&port->lock, flags);
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)
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;
518 * This means you called this function _after_ the port was
519 * closed. No cookie for you.
526 port = state->uart_port;
532 spin_lock_irqsave(&port->lock, flags);
534 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
539 memcpy(circ->buf + circ->head, buf, c);
540 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
547 spin_unlock_irqrestore(&port->lock, flags);
552 static int uart_write_room(struct tty_struct *tty)
554 struct uart_state *state = tty->driver_data;
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);
564 static int uart_chars_in_buffer(struct tty_struct *tty)
566 struct uart_state *state = tty->driver_data;
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);
576 static void uart_flush_buffer(struct tty_struct *tty)
578 struct uart_state *state = tty->driver_data;
579 struct uart_port *port;
583 * This means you called this function _after_ the port was
584 * closed. No cookie for you.
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);
603 * This function is used to send a high-priority XON/XOFF character to
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;
612 if (port->ops->send_xchar)
613 port->ops->send_xchar(port, ch);
615 spin_lock_irqsave(&port->lock, flags);
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;
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;
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
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)))
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;
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
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)) {
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))
770 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
771 (new_flags & UPF_USR_MASK));
772 uport->custom_divisor = new_info->custom_divisor;
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))
789 if (change_port || change_irq) {
793 * Make sure that we are the sole user of this port.
795 if (tty_port_users(port) > 1)
799 * We need to shutdown the serial port at the old
800 * port/type/irq combination.
802 uart_shutdown(tty, state);
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);
835 /* Always success - Jean II */
840 * If we fail to request resources for the
841 * new port, try to restore the old settings.
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,
858 uport->type = PORT_UNKNOWN;
866 /* Added to return the correct error -Ram Gupta */
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;
886 if (uport->type == PORT_UNKNOWN)
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) {
899 dev_notice(uport->dev,
900 "%s sets custom speed on %s. This is deprecated.\n",
902 tty_name(port->tty, buf));
904 uart_change_speed(tty, state, NULL);
907 retval = uart_startup(tty, state, 1);
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;
919 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
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
929 mutex_lock(&port->mutex);
930 retval = uart_set_info(tty, port, state, &new_serial);
931 mutex_unlock(&port->mutex);
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;
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).
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;
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);
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;
992 mutex_lock(&port->mutex);
993 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
994 uart_update_mctrl(uport, set, clear);
997 mutex_unlock(&port->mutex);
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);
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;
1022 if (!capable(CAP_SYS_ADMIN))
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;
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
1052 uport->ops->config_port(uport, flags);
1054 ret = uart_startup(tty, state, 1);
1056 mutex_unlock(&port->mutex);
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.
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;
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);
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))) {
1113 /* see if a signal did it */
1114 if (signal_pending(current)) {
1121 __set_current_state(TASK_RUNNING);
1122 remove_wait_queue(&port->delta_msr_wait, &wait);
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;
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);
1167 spin_unlock_irqrestore(&port->lock, flags);
1169 if (copy_to_user(rs485, &aux, sizeof(aux)))
1175 static int uart_set_rs485_config(struct uart_port *port,
1176 struct serial_rs485 __user *rs485_user)
1178 struct serial_rs485 rs485;
1180 unsigned long flags;
1182 if (!port->rs485_config)
1183 return -ENOIOCTLCMD;
1185 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1188 spin_lock_irqsave(&port->lock, flags);
1189 ret = port->rs485_config(port, &rs485);
1190 spin_unlock_irqrestore(&port->lock, flags);
1194 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1201 * Called via sys_ioctl. We can use spin_lock_irq() here.
1204 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
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.
1218 ret = uart_get_info_user(port, uarg);
1222 down_write(&tty->termios_rwsem);
1223 ret = uart_set_info_user(tty, state, uarg);
1224 up_write(&tty->termios_rwsem);
1228 down_write(&tty->termios_rwsem);
1229 ret = uart_do_autoconfig(tty, state);
1230 up_write(&tty->termios_rwsem);
1233 case TIOCSERGWILD: /* obsolete */
1234 case TIOCSERSWILD: /* obsolete */
1239 if (ret != -ENOIOCTLCMD)
1242 if (tty->flags & (1 << TTY_IO_ERROR)) {
1248 * The following should only be used when hardware is present.
1252 ret = uart_wait_modem_status(state, arg);
1256 if (ret != -ENOIOCTLCMD)
1259 mutex_lock(&port->mutex);
1261 if (tty->flags & (1 << TTY_IO_ERROR)) {
1267 * All these rely on hardware being present and need to be
1268 * protected against the tty being hung up.
1272 case TIOCSERGETLSR: /* Get line status register */
1273 ret = uart_get_lsr_info(tty, state, uarg);
1277 ret = uart_get_rs485_config(state->uart_port, uarg);
1281 ret = uart_set_rs485_config(state->uart_port, uarg);
1284 struct uart_port *uport = state->uart_port;
1285 if (uport->ops->ioctl)
1286 ret = uport->ops->ioctl(uport, cmd, arg);
1291 mutex_unlock(&port->mutex);
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;
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 &&
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))
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;
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);
1380 spin_unlock_irq(&port->lock);
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)
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);
1440 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1442 struct uart_state *state = tty->driver_data;
1443 struct uart_port *port = state->uart_port;
1444 unsigned long char_time, expire;
1446 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1450 * Set the check interval to be 1/5 of the estimated time to
1451 * send a single character, and make it at least 1. The check
1452 * interval should also be less than the timeout.
1454 * Note: we have to use pretty tight timings here to satisfy
1457 char_time = (port->timeout - HZ/50) / port->fifosize;
1458 char_time = char_time / 5;
1461 if (timeout && timeout < char_time)
1462 char_time = timeout;
1465 * If the transmitter hasn't cleared in twice the approximate
1466 * amount of time to send the entire FIFO, it probably won't
1467 * ever clear. This assumes the UART isn't doing flow
1468 * control, which is currently the case. Hence, if it ever
1469 * takes longer than port->timeout, this is probably due to a
1470 * UART bug of some kind. So, we clamp the timeout parameter at
1473 if (timeout == 0 || timeout > 2 * port->timeout)
1474 timeout = 2 * port->timeout;
1476 expire = jiffies + timeout;
1478 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1479 port->line, jiffies, expire);
1482 * Check whether the transmitter is empty every 'char_time'.
1483 * 'timeout' / 'expire' give us the maximum amount of time
1486 while (!port->ops->tx_empty(port)) {
1487 msleep_interruptible(jiffies_to_msecs(char_time));
1488 if (signal_pending(current))
1490 if (time_after(jiffies, expire))
1496 * Calls to uart_hangup() are serialised by the tty_lock in
1497 * drivers/tty/tty_io.c:do_tty_hangup()
1498 * This runs from a workqueue and can sleep for a _short_ time only.
1500 static void uart_hangup(struct tty_struct *tty)
1502 struct uart_state *state = tty->driver_data;
1503 struct tty_port *port = &state->port;
1504 unsigned long flags;
1506 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1508 mutex_lock(&port->mutex);
1509 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1510 uart_flush_buffer(tty);
1511 uart_shutdown(tty, state);
1512 spin_lock_irqsave(&port->lock, flags);
1514 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1515 spin_unlock_irqrestore(&port->lock, flags);
1516 tty_port_tty_set(port, NULL);
1517 if (!uart_console(state->uart_port))
1518 uart_change_pm(state, UART_PM_STATE_OFF);
1519 wake_up_interruptible(&port->open_wait);
1520 wake_up_interruptible(&port->delta_msr_wait);
1522 mutex_unlock(&port->mutex);
1525 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1530 static void uart_port_shutdown(struct tty_port *port)
1532 struct uart_state *state = container_of(port, struct uart_state, port);
1533 struct uart_port *uport = state->uart_port;
1536 * clear delta_msr_wait queue to avoid mem leaks: we may free
1537 * the irq here so the queue might never be woken up. Note
1538 * that we won't end up waiting on delta_msr_wait again since
1539 * any outstanding file descriptors should be pointing at
1540 * hung_up_tty_fops now.
1542 wake_up_interruptible(&port->delta_msr_wait);
1545 * Free the IRQ and disable the port.
1547 uport->ops->shutdown(uport);
1550 * Ensure that the IRQ handler isn't running on another CPU.
1552 synchronize_irq(uport->irq);
1555 static int uart_carrier_raised(struct tty_port *port)
1557 struct uart_state *state = container_of(port, struct uart_state, port);
1558 struct uart_port *uport = state->uart_port;
1560 spin_lock_irq(&uport->lock);
1561 uart_enable_ms(uport);
1562 mctrl = uport->ops->get_mctrl(uport);
1563 spin_unlock_irq(&uport->lock);
1564 if (mctrl & TIOCM_CAR)
1569 static void uart_dtr_rts(struct tty_port *port, int onoff)
1571 struct uart_state *state = container_of(port, struct uart_state, port);
1572 struct uart_port *uport = state->uart_port;
1575 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1577 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1581 * Calls to uart_open are serialised by the tty_lock in
1582 * drivers/tty/tty_io.c:tty_open()
1583 * Note that if this fails, then uart_close() _will_ be called.
1585 * In time, we want to scrap the "opening nonpresent ports"
1586 * behaviour and implement an alternative way for setserial
1587 * to set base addresses/ports/types. This will allow us to
1588 * get rid of a certain amount of extra tests.
1590 static int uart_open(struct tty_struct *tty, struct file *filp)
1592 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1593 int retval, line = tty->index;
1594 struct uart_state *state = drv->state + line;
1595 struct tty_port *port = &state->port;
1597 pr_debug("uart_open(%d) called\n", line);
1599 spin_lock_irq(&port->lock);
1601 spin_unlock_irq(&port->lock);
1604 * We take the semaphore here to guarantee that we won't be re-entered
1605 * while allocating the state structure, or while we request any IRQs
1606 * that the driver may need. This also has the nice side-effect that
1607 * it delays the action of uart_hangup, so we can guarantee that
1608 * state->port.tty will always contain something reasonable.
1610 if (mutex_lock_interruptible(&port->mutex)) {
1611 retval = -ERESTARTSYS;
1615 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1620 tty->driver_data = state;
1621 state->uart_port->state = state;
1622 state->port.low_latency =
1623 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1624 tty_port_tty_set(port, tty);
1627 * Start up the serial port.
1629 retval = uart_startup(tty, state, 0);
1632 * If we succeeded, wait until the port is ready.
1634 mutex_unlock(&port->mutex);
1636 retval = tty_port_block_til_ready(port, tty, filp);
1641 mutex_unlock(&port->mutex);
1645 static const char *uart_type(struct uart_port *port)
1647 const char *str = NULL;
1649 if (port->ops->type)
1650 str = port->ops->type(port);
1658 #ifdef CONFIG_PROC_FS
1660 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1662 struct uart_state *state = drv->state + i;
1663 struct tty_port *port = &state->port;
1664 enum uart_pm_state pm_state;
1665 struct uart_port *uport = state->uart_port;
1667 unsigned int status;
1673 mmio = uport->iotype >= UPIO_MEM;
1674 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1675 uport->line, uart_type(uport),
1676 mmio ? "mmio:0x" : "port:",
1677 mmio ? (unsigned long long)uport->mapbase
1678 : (unsigned long long)uport->iobase,
1681 if (uport->type == PORT_UNKNOWN) {
1686 if (capable(CAP_SYS_ADMIN)) {
1687 mutex_lock(&port->mutex);
1688 pm_state = state->pm_state;
1689 if (pm_state != UART_PM_STATE_ON)
1690 uart_change_pm(state, UART_PM_STATE_ON);
1691 spin_lock_irq(&uport->lock);
1692 status = uport->ops->get_mctrl(uport);
1693 spin_unlock_irq(&uport->lock);
1694 if (pm_state != UART_PM_STATE_ON)
1695 uart_change_pm(state, pm_state);
1696 mutex_unlock(&port->mutex);
1698 seq_printf(m, " tx:%d rx:%d",
1699 uport->icount.tx, uport->icount.rx);
1700 if (uport->icount.frame)
1701 seq_printf(m, " fe:%d",
1702 uport->icount.frame);
1703 if (uport->icount.parity)
1704 seq_printf(m, " pe:%d",
1705 uport->icount.parity);
1706 if (uport->icount.brk)
1707 seq_printf(m, " brk:%d",
1709 if (uport->icount.overrun)
1710 seq_printf(m, " oe:%d",
1711 uport->icount.overrun);
1713 #define INFOBIT(bit, str) \
1714 if (uport->mctrl & (bit)) \
1715 strncat(stat_buf, (str), sizeof(stat_buf) - \
1716 strlen(stat_buf) - 2)
1717 #define STATBIT(bit, str) \
1718 if (status & (bit)) \
1719 strncat(stat_buf, (str), sizeof(stat_buf) - \
1720 strlen(stat_buf) - 2)
1724 INFOBIT(TIOCM_RTS, "|RTS");
1725 STATBIT(TIOCM_CTS, "|CTS");
1726 INFOBIT(TIOCM_DTR, "|DTR");
1727 STATBIT(TIOCM_DSR, "|DSR");
1728 STATBIT(TIOCM_CAR, "|CD");
1729 STATBIT(TIOCM_RNG, "|RI");
1733 seq_puts(m, stat_buf);
1740 static int uart_proc_show(struct seq_file *m, void *v)
1742 struct tty_driver *ttydrv = m->private;
1743 struct uart_driver *drv = ttydrv->driver_state;
1746 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1748 for (i = 0; i < drv->nr; i++)
1749 uart_line_info(m, drv, i);
1753 static int uart_proc_open(struct inode *inode, struct file *file)
1755 return single_open(file, uart_proc_show, PDE_DATA(inode));
1758 static const struct file_operations uart_proc_fops = {
1759 .owner = THIS_MODULE,
1760 .open = uart_proc_open,
1762 .llseek = seq_lseek,
1763 .release = single_release,
1767 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1769 * uart_console_write - write a console message to a serial port
1770 * @port: the port to write the message
1771 * @s: array of characters
1772 * @count: number of characters in string to write
1773 * @putchar: function to write character to port
1775 void uart_console_write(struct uart_port *port, const char *s,
1777 void (*putchar)(struct uart_port *, int))
1781 for (i = 0; i < count; i++, s++) {
1783 putchar(port, '\r');
1787 EXPORT_SYMBOL_GPL(uart_console_write);
1790 * Check whether an invalid uart number has been specified, and
1791 * if so, search for the first available port that does have
1794 struct uart_port * __init
1795 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1797 int idx = co->index;
1799 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1800 ports[idx].membase == NULL))
1801 for (idx = 0; idx < nr; idx++)
1802 if (ports[idx].iobase != 0 ||
1803 ports[idx].membase != NULL)
1812 * uart_parse_earlycon - Parse earlycon options
1813 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1814 * @iotype: ptr for decoded iotype (out)
1815 * @addr: ptr for decoded mapbase/iobase (out)
1816 * @options: ptr for <options> field; NULL if not present (out)
1818 * Decodes earlycon kernel command line parameters of the form
1819 * earlycon=<name>,io|mmio|mmio32,<addr>,<options>
1820 * console=<name>,io|mmio|mmio32,<addr>,<options>
1823 * earlycon=<name>,0x<addr>,<options>
1824 * console=<name>,0x<addr>,<options>
1825 * is also accepted; the returned @iotype will be UPIO_MEM.
1827 * Returns 0 on success or -EINVAL on failure
1829 int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
1832 if (strncmp(p, "mmio,", 5) == 0) {
1835 } else if (strncmp(p, "mmio32,", 7) == 0) {
1836 *iotype = UPIO_MEM32;
1838 } else if (strncmp(p, "io,", 3) == 0) {
1839 *iotype = UPIO_PORT;
1841 } else if (strncmp(p, "0x", 2) == 0) {
1847 *addr = simple_strtoul(p, NULL, 0);
1855 EXPORT_SYMBOL_GPL(uart_parse_earlycon);
1858 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1859 * @options: pointer to option string
1860 * @baud: pointer to an 'int' variable for the baud rate.
1861 * @parity: pointer to an 'int' variable for the parity.
1862 * @bits: pointer to an 'int' variable for the number of data bits.
1863 * @flow: pointer to an 'int' variable for the flow control character.
1865 * uart_parse_options decodes a string containing the serial console
1866 * options. The format of the string is <baud><parity><bits><flow>,
1870 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1874 *baud = simple_strtoul(s, NULL, 10);
1875 while (*s >= '0' && *s <= '9')
1884 EXPORT_SYMBOL_GPL(uart_parse_options);
1891 static const struct baud_rates baud_rates[] = {
1892 { 921600, B921600 },
1893 { 460800, B460800 },
1894 { 230400, B230400 },
1895 { 115200, B115200 },
1907 * uart_set_options - setup the serial console parameters
1908 * @port: pointer to the serial ports uart_port structure
1909 * @co: console pointer
1911 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1912 * @bits: number of data bits
1913 * @flow: flow control character - 'r' (rts)
1916 uart_set_options(struct uart_port *port, struct console *co,
1917 int baud, int parity, int bits, int flow)
1919 struct ktermios termios;
1920 static struct ktermios dummy;
1924 * Ensure that the serial console lock is initialised
1926 * If this port is a console, then the spinlock is already
1929 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1930 spin_lock_init(&port->lock);
1931 lockdep_set_class(&port->lock, &port_lock_key);
1934 memset(&termios, 0, sizeof(struct ktermios));
1936 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1939 * Construct a cflag setting.
1941 for (i = 0; baud_rates[i].rate; i++)
1942 if (baud_rates[i].rate <= baud)
1945 termios.c_cflag |= baud_rates[i].cflag;
1948 termios.c_cflag |= CS7;
1950 termios.c_cflag |= CS8;
1954 termios.c_cflag |= PARODD;
1957 termios.c_cflag |= PARENB;
1962 termios.c_cflag |= CRTSCTS;
1965 * some uarts on other side don't support no flow control.
1966 * So we set * DTR in host uart to make them happy
1968 port->mctrl |= TIOCM_DTR;
1970 port->ops->set_termios(port, &termios, &dummy);
1972 * Allow the setting of the UART parameters with a NULL console
1976 co->cflag = termios.c_cflag;
1980 EXPORT_SYMBOL_GPL(uart_set_options);
1981 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1984 * uart_change_pm - set power state of the port
1986 * @state: port descriptor
1987 * @pm_state: new state
1989 * Locking: port->mutex has to be held
1991 static void uart_change_pm(struct uart_state *state,
1992 enum uart_pm_state pm_state)
1994 struct uart_port *port = state->uart_port;
1996 if (state->pm_state != pm_state) {
1998 port->ops->pm(port, pm_state, state->pm_state);
1999 state->pm_state = pm_state;
2004 struct uart_port *port;
2005 struct uart_driver *driver;
2008 static int serial_match_port(struct device *dev, void *data)
2010 struct uart_match *match = data;
2011 struct tty_driver *tty_drv = match->driver->tty_driver;
2012 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
2015 return dev->devt == devt; /* Actually, only one tty per port */
2018 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
2020 struct uart_state *state = drv->state + uport->line;
2021 struct tty_port *port = &state->port;
2022 struct device *tty_dev;
2023 struct uart_match match = {uport, drv};
2025 mutex_lock(&port->mutex);
2027 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2028 if (device_may_wakeup(tty_dev)) {
2029 if (!enable_irq_wake(uport->irq))
2030 uport->irq_wake = 1;
2031 put_device(tty_dev);
2032 mutex_unlock(&port->mutex);
2035 put_device(tty_dev);
2037 /* Nothing to do if the console is not suspending */
2038 if (!console_suspend_enabled && uart_console(uport))
2041 uport->suspended = 1;
2043 if (port->flags & ASYNC_INITIALIZED) {
2044 const struct uart_ops *ops = uport->ops;
2047 set_bit(ASYNCB_SUSPENDED, &port->flags);
2048 clear_bit(ASYNCB_INITIALIZED, &port->flags);
2050 spin_lock_irq(&uport->lock);
2051 ops->stop_tx(uport);
2052 ops->set_mctrl(uport, 0);
2053 ops->stop_rx(uport);
2054 spin_unlock_irq(&uport->lock);
2057 * Wait for the transmitter to empty.
2059 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2062 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
2064 drv->tty_driver->name_base + uport->line);
2066 ops->shutdown(uport);
2070 * Disable the console device before suspending.
2072 if (uart_console(uport))
2073 console_stop(uport->cons);
2075 uart_change_pm(state, UART_PM_STATE_OFF);
2077 mutex_unlock(&port->mutex);
2082 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2084 struct uart_state *state = drv->state + uport->line;
2085 struct tty_port *port = &state->port;
2086 struct device *tty_dev;
2087 struct uart_match match = {uport, drv};
2088 struct ktermios termios;
2090 mutex_lock(&port->mutex);
2092 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2093 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2094 if (uport->irq_wake) {
2095 disable_irq_wake(uport->irq);
2096 uport->irq_wake = 0;
2098 put_device(tty_dev);
2099 mutex_unlock(&port->mutex);
2102 put_device(tty_dev);
2103 uport->suspended = 0;
2106 * Re-enable the console device after suspending.
2108 if (uart_console(uport)) {
2110 * First try to use the console cflag setting.
2112 memset(&termios, 0, sizeof(struct ktermios));
2113 termios.c_cflag = uport->cons->cflag;
2116 * If that's unset, use the tty termios setting.
2118 if (port->tty && termios.c_cflag == 0)
2119 termios = port->tty->termios;
2121 if (console_suspend_enabled)
2122 uart_change_pm(state, UART_PM_STATE_ON);
2123 uport->ops->set_termios(uport, &termios, NULL);
2124 if (console_suspend_enabled)
2125 console_start(uport->cons);
2128 if (port->flags & ASYNC_SUSPENDED) {
2129 const struct uart_ops *ops = uport->ops;
2132 uart_change_pm(state, UART_PM_STATE_ON);
2133 spin_lock_irq(&uport->lock);
2134 ops->set_mctrl(uport, 0);
2135 spin_unlock_irq(&uport->lock);
2136 if (console_suspend_enabled || !uart_console(uport)) {
2137 /* Protected by port mutex for now */
2138 struct tty_struct *tty = port->tty;
2139 ret = ops->startup(uport);
2142 uart_change_speed(tty, state, NULL);
2143 spin_lock_irq(&uport->lock);
2144 ops->set_mctrl(uport, uport->mctrl);
2145 ops->start_tx(uport);
2146 spin_unlock_irq(&uport->lock);
2147 set_bit(ASYNCB_INITIALIZED, &port->flags);
2150 * Failed to resume - maybe hardware went away?
2151 * Clear the "initialized" flag so we won't try
2152 * to call the low level drivers shutdown method.
2154 uart_shutdown(tty, state);
2158 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2161 mutex_unlock(&port->mutex);
2167 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2171 switch (port->iotype) {
2173 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2176 snprintf(address, sizeof(address),
2177 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2184 snprintf(address, sizeof(address),
2185 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2188 strlcpy(address, "*unknown*", sizeof(address));
2192 printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2193 port->dev ? dev_name(port->dev) : "",
2194 port->dev ? ": " : "",
2196 drv->tty_driver->name_base + port->line,
2197 address, port->irq, port->uartclk / 16, uart_type(port));
2201 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2202 struct uart_port *port)
2207 * If there isn't a port here, don't do anything further.
2209 if (!port->iobase && !port->mapbase && !port->membase)
2213 * Now do the auto configuration stuff. Note that config_port
2214 * is expected to claim the resources and map the port for us.
2217 if (port->flags & UPF_AUTO_IRQ)
2218 flags |= UART_CONFIG_IRQ;
2219 if (port->flags & UPF_BOOT_AUTOCONF) {
2220 if (!(port->flags & UPF_FIXED_TYPE)) {
2221 port->type = PORT_UNKNOWN;
2222 flags |= UART_CONFIG_TYPE;
2224 port->ops->config_port(port, flags);
2227 if (port->type != PORT_UNKNOWN) {
2228 unsigned long flags;
2230 uart_report_port(drv, port);
2232 /* Power up port for set_mctrl() */
2233 uart_change_pm(state, UART_PM_STATE_ON);
2236 * Ensure that the modem control lines are de-activated.
2237 * keep the DTR setting that is set in uart_set_options()
2238 * We probably don't need a spinlock around this, but
2240 spin_lock_irqsave(&port->lock, flags);
2241 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2242 spin_unlock_irqrestore(&port->lock, flags);
2245 * If this driver supports console, and it hasn't been
2246 * successfully registered yet, try to re-register it.
2247 * It may be that the port was not available.
2249 if (port->cons && !(port->cons->flags & CON_ENABLED))
2250 register_console(port->cons);
2253 * Power down all ports by default, except the
2254 * console if we have one.
2256 if (!uart_console(port))
2257 uart_change_pm(state, UART_PM_STATE_OFF);
2261 #ifdef CONFIG_CONSOLE_POLL
2263 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2265 struct uart_driver *drv = driver->driver_state;
2266 struct uart_state *state = drv->state + line;
2267 struct uart_port *port;
2274 if (!state || !state->uart_port)
2277 port = state->uart_port;
2278 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2281 if (port->ops->poll_init) {
2282 struct tty_port *tport = &state->port;
2285 mutex_lock(&tport->mutex);
2287 * We don't set ASYNCB_INITIALIZED as we only initialized the
2288 * hw, e.g. state->xmit is still uninitialized.
2290 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2291 ret = port->ops->poll_init(port);
2292 mutex_unlock(&tport->mutex);
2298 uart_parse_options(options, &baud, &parity, &bits, &flow);
2299 return uart_set_options(port, NULL, baud, parity, bits, flow);
2305 static int uart_poll_get_char(struct tty_driver *driver, int line)
2307 struct uart_driver *drv = driver->driver_state;
2308 struct uart_state *state = drv->state + line;
2309 struct uart_port *port;
2311 if (!state || !state->uart_port)
2314 port = state->uart_port;
2315 return port->ops->poll_get_char(port);
2318 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2320 struct uart_driver *drv = driver->driver_state;
2321 struct uart_state *state = drv->state + line;
2322 struct uart_port *port;
2324 if (!state || !state->uart_port)
2327 port = state->uart_port;
2330 port->ops->poll_put_char(port, '\r');
2331 port->ops->poll_put_char(port, ch);
2335 static const struct tty_operations uart_ops = {
2337 .close = uart_close,
2338 .write = uart_write,
2339 .put_char = uart_put_char,
2340 .flush_chars = uart_flush_chars,
2341 .write_room = uart_write_room,
2342 .chars_in_buffer= uart_chars_in_buffer,
2343 .flush_buffer = uart_flush_buffer,
2344 .ioctl = uart_ioctl,
2345 .throttle = uart_throttle,
2346 .unthrottle = uart_unthrottle,
2347 .send_xchar = uart_send_xchar,
2348 .set_termios = uart_set_termios,
2349 .set_ldisc = uart_set_ldisc,
2351 .start = uart_start,
2352 .hangup = uart_hangup,
2353 .break_ctl = uart_break_ctl,
2354 .wait_until_sent= uart_wait_until_sent,
2355 #ifdef CONFIG_PROC_FS
2356 .proc_fops = &uart_proc_fops,
2358 .tiocmget = uart_tiocmget,
2359 .tiocmset = uart_tiocmset,
2360 .get_icount = uart_get_icount,
2361 #ifdef CONFIG_CONSOLE_POLL
2362 .poll_init = uart_poll_init,
2363 .poll_get_char = uart_poll_get_char,
2364 .poll_put_char = uart_poll_put_char,
2368 static const struct tty_port_operations uart_port_ops = {
2369 .activate = uart_port_activate,
2370 .shutdown = uart_port_shutdown,
2371 .carrier_raised = uart_carrier_raised,
2372 .dtr_rts = uart_dtr_rts,
2376 * uart_register_driver - register a driver with the uart core layer
2377 * @drv: low level driver structure
2379 * Register a uart driver with the core driver. We in turn register
2380 * with the tty layer, and initialise the core driver per-port state.
2382 * We have a proc file in /proc/tty/driver which is named after the
2385 * drv->port should be NULL, and the per-port structures should be
2386 * registered using uart_add_one_port after this call has succeeded.
2388 int uart_register_driver(struct uart_driver *drv)
2390 struct tty_driver *normal;
2396 * Maybe we should be using a slab cache for this, especially if
2397 * we have a large number of ports to handle.
2399 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2403 normal = alloc_tty_driver(drv->nr);
2407 drv->tty_driver = normal;
2409 normal->driver_name = drv->driver_name;
2410 normal->name = drv->dev_name;
2411 normal->major = drv->major;
2412 normal->minor_start = drv->minor;
2413 normal->type = TTY_DRIVER_TYPE_SERIAL;
2414 normal->subtype = SERIAL_TYPE_NORMAL;
2415 normal->init_termios = tty_std_termios;
2416 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2417 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2418 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2419 normal->driver_state = drv;
2420 tty_set_operations(normal, &uart_ops);
2423 * Initialise the UART state(s).
2425 for (i = 0; i < drv->nr; i++) {
2426 struct uart_state *state = drv->state + i;
2427 struct tty_port *port = &state->port;
2429 tty_port_init(port);
2430 port->ops = &uart_port_ops;
2433 retval = tty_register_driver(normal);
2437 for (i = 0; i < drv->nr; i++)
2438 tty_port_destroy(&drv->state[i].port);
2439 put_tty_driver(normal);
2447 * uart_unregister_driver - remove a driver from the uart core layer
2448 * @drv: low level driver structure
2450 * Remove all references to a driver from the core driver. The low
2451 * level driver must have removed all its ports via the
2452 * uart_remove_one_port() if it registered them with uart_add_one_port().
2453 * (ie, drv->port == NULL)
2455 void uart_unregister_driver(struct uart_driver *drv)
2457 struct tty_driver *p = drv->tty_driver;
2460 tty_unregister_driver(p);
2462 for (i = 0; i < drv->nr; i++)
2463 tty_port_destroy(&drv->state[i].port);
2466 drv->tty_driver = NULL;
2469 struct tty_driver *uart_console_device(struct console *co, int *index)
2471 struct uart_driver *p = co->data;
2473 return p->tty_driver;
2476 static ssize_t uart_get_attr_uartclk(struct device *dev,
2477 struct device_attribute *attr, char *buf)
2479 struct serial_struct tmp;
2480 struct tty_port *port = dev_get_drvdata(dev);
2482 uart_get_info(port, &tmp);
2483 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2486 static ssize_t uart_get_attr_type(struct device *dev,
2487 struct device_attribute *attr, char *buf)
2489 struct serial_struct tmp;
2490 struct tty_port *port = dev_get_drvdata(dev);
2492 uart_get_info(port, &tmp);
2493 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2495 static ssize_t uart_get_attr_line(struct device *dev,
2496 struct device_attribute *attr, char *buf)
2498 struct serial_struct tmp;
2499 struct tty_port *port = dev_get_drvdata(dev);
2501 uart_get_info(port, &tmp);
2502 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2505 static ssize_t uart_get_attr_port(struct device *dev,
2506 struct device_attribute *attr, char *buf)
2508 struct serial_struct tmp;
2509 struct tty_port *port = dev_get_drvdata(dev);
2510 unsigned long ioaddr;
2512 uart_get_info(port, &tmp);
2514 if (HIGH_BITS_OFFSET)
2515 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2516 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2519 static ssize_t uart_get_attr_irq(struct device *dev,
2520 struct device_attribute *attr, char *buf)
2522 struct serial_struct tmp;
2523 struct tty_port *port = dev_get_drvdata(dev);
2525 uart_get_info(port, &tmp);
2526 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2529 static ssize_t uart_get_attr_flags(struct device *dev,
2530 struct device_attribute *attr, char *buf)
2532 struct serial_struct tmp;
2533 struct tty_port *port = dev_get_drvdata(dev);
2535 uart_get_info(port, &tmp);
2536 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2539 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2540 struct device_attribute *attr, char *buf)
2542 struct serial_struct tmp;
2543 struct tty_port *port = dev_get_drvdata(dev);
2545 uart_get_info(port, &tmp);
2546 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2550 static ssize_t uart_get_attr_close_delay(struct device *dev,
2551 struct device_attribute *attr, char *buf)
2553 struct serial_struct tmp;
2554 struct tty_port *port = dev_get_drvdata(dev);
2556 uart_get_info(port, &tmp);
2557 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2561 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2562 struct device_attribute *attr, char *buf)
2564 struct serial_struct tmp;
2565 struct tty_port *port = dev_get_drvdata(dev);
2567 uart_get_info(port, &tmp);
2568 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2571 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2572 struct device_attribute *attr, char *buf)
2574 struct serial_struct tmp;
2575 struct tty_port *port = dev_get_drvdata(dev);
2577 uart_get_info(port, &tmp);
2578 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2581 static ssize_t uart_get_attr_io_type(struct device *dev,
2582 struct device_attribute *attr, char *buf)
2584 struct serial_struct tmp;
2585 struct tty_port *port = dev_get_drvdata(dev);
2587 uart_get_info(port, &tmp);
2588 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2591 static ssize_t uart_get_attr_iomem_base(struct device *dev,
2592 struct device_attribute *attr, char *buf)
2594 struct serial_struct tmp;
2595 struct tty_port *port = dev_get_drvdata(dev);
2597 uart_get_info(port, &tmp);
2598 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2601 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2602 struct device_attribute *attr, char *buf)
2604 struct serial_struct tmp;
2605 struct tty_port *port = dev_get_drvdata(dev);
2607 uart_get_info(port, &tmp);
2608 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2611 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2612 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2613 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2614 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2615 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2616 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2617 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2618 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2619 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2620 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2621 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2622 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2623 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2625 static struct attribute *tty_dev_attrs[] = {
2626 &dev_attr_type.attr,
2627 &dev_attr_line.attr,
2628 &dev_attr_port.attr,
2630 &dev_attr_flags.attr,
2631 &dev_attr_xmit_fifo_size.attr,
2632 &dev_attr_uartclk.attr,
2633 &dev_attr_close_delay.attr,
2634 &dev_attr_closing_wait.attr,
2635 &dev_attr_custom_divisor.attr,
2636 &dev_attr_io_type.attr,
2637 &dev_attr_iomem_base.attr,
2638 &dev_attr_iomem_reg_shift.attr,
2642 static const struct attribute_group tty_dev_attr_group = {
2643 .attrs = tty_dev_attrs,
2647 * uart_add_one_port - attach a driver-defined port structure
2648 * @drv: pointer to the uart low level driver structure for this port
2649 * @uport: uart port structure to use for this port.
2651 * This allows the driver to register its own uart_port structure
2652 * with the core driver. The main purpose is to allow the low
2653 * level uart drivers to expand uart_port, rather than having yet
2654 * more levels of structures.
2656 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2658 struct uart_state *state;
2659 struct tty_port *port;
2661 struct device *tty_dev;
2664 BUG_ON(in_interrupt());
2666 if (uport->line >= drv->nr)
2669 state = drv->state + uport->line;
2670 port = &state->port;
2672 mutex_lock(&port_mutex);
2673 mutex_lock(&port->mutex);
2674 if (state->uart_port) {
2679 /* Link the port to the driver state table and vice versa */
2680 state->uart_port = uport;
2681 uport->state = state;
2683 state->pm_state = UART_PM_STATE_UNDEFINED;
2684 uport->cons = drv->cons;
2685 uport->minor = drv->tty_driver->minor_start + uport->line;
2688 * If this port is a console, then the spinlock is already
2691 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2692 spin_lock_init(&uport->lock);
2693 lockdep_set_class(&uport->lock, &port_lock_key);
2695 if (uport->cons && uport->dev)
2696 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2698 uart_configure_port(drv, state, uport);
2701 if (uport->attr_group)
2704 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2706 if (!uport->tty_groups) {
2710 uport->tty_groups[0] = &tty_dev_attr_group;
2711 if (uport->attr_group)
2712 uport->tty_groups[1] = uport->attr_group;
2715 * Register the port whether it's detected or not. This allows
2716 * setserial to be used to alter this port's parameters.
2718 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2719 uport->line, uport->dev, port, uport->tty_groups);
2720 if (likely(!IS_ERR(tty_dev))) {
2721 device_set_wakeup_capable(tty_dev, 1);
2723 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2728 * Ensure UPF_DEAD is not set.
2730 uport->flags &= ~UPF_DEAD;
2733 mutex_unlock(&port->mutex);
2734 mutex_unlock(&port_mutex);
2740 * uart_remove_one_port - detach a driver defined port structure
2741 * @drv: pointer to the uart low level driver structure for this port
2742 * @uport: uart port structure for this port
2744 * This unhooks (and hangs up) the specified port structure from the
2745 * core driver. No further calls will be made to the low-level code
2748 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2750 struct uart_state *state = drv->state + uport->line;
2751 struct tty_port *port = &state->port;
2752 struct tty_struct *tty;
2755 BUG_ON(in_interrupt());
2757 if (state->uart_port != uport)
2758 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2759 state->uart_port, uport);
2761 mutex_lock(&port_mutex);
2764 * Mark the port "dead" - this prevents any opens from
2765 * succeeding while we shut down the port.
2767 mutex_lock(&port->mutex);
2768 if (!state->uart_port) {
2769 mutex_unlock(&port->mutex);
2773 uport->flags |= UPF_DEAD;
2774 mutex_unlock(&port->mutex);
2777 * Remove the devices from the tty layer
2779 tty_unregister_device(drv->tty_driver, uport->line);
2781 tty = tty_port_tty_get(port);
2783 tty_vhangup(port->tty);
2788 * If the port is used as a console, unregister it
2790 if (uart_console(uport))
2791 unregister_console(uport->cons);
2794 * Free the port IO and memory resources, if any.
2796 if (uport->type != PORT_UNKNOWN)
2797 uport->ops->release_port(uport);
2798 kfree(uport->tty_groups);
2801 * Indicate that there isn't a port here anymore.
2803 uport->type = PORT_UNKNOWN;
2805 state->uart_port = NULL;
2807 mutex_unlock(&port_mutex);
2813 * Are the two ports equivalent?
2815 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2817 if (port1->iotype != port2->iotype)
2820 switch (port1->iotype) {
2822 return (port1->iobase == port2->iobase);
2824 return (port1->iobase == port2->iobase) &&
2825 (port1->hub6 == port2->hub6);
2831 return (port1->mapbase == port2->mapbase);
2835 EXPORT_SYMBOL(uart_match_port);
2838 * uart_handle_dcd_change - handle a change of carrier detect state
2839 * @uport: uart_port structure for the open port
2840 * @status: new carrier detect status, nonzero if active
2842 * Caller must hold uport->lock
2844 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2846 struct tty_port *port = &uport->state->port;
2847 struct tty_struct *tty = port->tty;
2848 struct tty_ldisc *ld;
2850 lockdep_assert_held_once(&uport->lock);
2853 ld = tty_ldisc_ref(tty);
2855 if (ld->ops->dcd_change)
2856 ld->ops->dcd_change(tty, status);
2857 tty_ldisc_deref(ld);
2861 uport->icount.dcd++;
2863 if (uart_dcd_enabled(uport)) {
2865 wake_up_interruptible(&port->open_wait);
2870 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2873 * uart_handle_cts_change - handle a change of clear-to-send state
2874 * @uport: uart_port structure for the open port
2875 * @status: new clear to send status, nonzero if active
2877 * Caller must hold uport->lock
2879 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2881 lockdep_assert_held_once(&uport->lock);
2883 uport->icount.cts++;
2885 if (uart_softcts_mode(uport)) {
2886 if (uport->hw_stopped) {
2888 uport->hw_stopped = 0;
2889 uport->ops->start_tx(uport);
2890 uart_write_wakeup(uport);
2894 uport->hw_stopped = 1;
2895 uport->ops->stop_tx(uport);
2901 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2904 * uart_insert_char - push a char to the uart layer
2906 * User is responsible to call tty_flip_buffer_push when they are done with
2909 * @port: corresponding port
2910 * @status: state of the serial port RX buffer (LSR for 8250)
2911 * @overrun: mask of overrun bits in @status
2912 * @ch: character to push
2913 * @flag: flag for the character (see TTY_NORMAL and friends)
2915 void uart_insert_char(struct uart_port *port, unsigned int status,
2916 unsigned int overrun, unsigned int ch, unsigned int flag)
2918 struct tty_port *tport = &port->state->port;
2920 if ((status & port->ignore_status_mask & ~overrun) == 0)
2921 if (tty_insert_flip_char(tport, ch, flag) == 0)
2922 ++port->icount.buf_overrun;
2925 * Overrun is special. Since it's reported immediately,
2926 * it doesn't affect the current character.
2928 if (status & ~port->ignore_status_mask & overrun)
2929 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2930 ++port->icount.buf_overrun;
2932 EXPORT_SYMBOL_GPL(uart_insert_char);
2934 EXPORT_SYMBOL(uart_write_wakeup);
2935 EXPORT_SYMBOL(uart_register_driver);
2936 EXPORT_SYMBOL(uart_unregister_driver);
2937 EXPORT_SYMBOL(uart_suspend_port);
2938 EXPORT_SYMBOL(uart_resume_port);
2939 EXPORT_SYMBOL(uart_add_one_port);
2940 EXPORT_SYMBOL(uart_remove_one_port);
2942 MODULE_DESCRIPTION("Serial driver core");
2943 MODULE_LICENSE("GPL");