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/sched/signal.h>
28 #include <linux/init.h>
29 #include <linux/console.h>
31 #include <linux/proc_fs.h>
32 #include <linux/seq_file.h>
33 #include <linux/device.h>
34 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
35 #include <linux/serial_core.h>
36 #include <linux/delay.h>
37 #include <linux/mutex.h>
40 #include <linux/uaccess.h>
43 * This is used to lock changes in serial line configuration.
45 static DEFINE_MUTEX(port_mutex);
48 * lockdep: port->lock is initialized in two places, but we
49 * want only one lock-class:
51 static struct lock_class_key port_lock_key;
53 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
55 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
56 struct ktermios *old_termios);
57 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
58 static void uart_change_pm(struct uart_state *state,
59 enum uart_pm_state pm_state);
61 static void uart_port_shutdown(struct tty_port *port);
63 static int uart_dcd_enabled(struct uart_port *uport)
65 return !!(uport->status & UPSTAT_DCD_ENABLE);
68 static inline struct uart_port *uart_port_ref(struct uart_state *state)
70 if (atomic_add_unless(&state->refcount, 1, 0))
71 return state->uart_port;
75 static inline void uart_port_deref(struct uart_port *uport)
77 if (atomic_dec_and_test(&uport->state->refcount))
78 wake_up(&uport->state->remove_wait);
81 #define uart_port_lock(state, flags) \
83 struct uart_port *__uport = uart_port_ref(state); \
85 spin_lock_irqsave(&__uport->lock, flags); \
89 #define uart_port_unlock(uport, flags) \
91 struct uart_port *__uport = uport; \
93 spin_unlock_irqrestore(&__uport->lock, flags); \
94 uart_port_deref(__uport); \
98 static inline struct uart_port *uart_port_check(struct uart_state *state)
100 lockdep_assert_held(&state->port.mutex);
101 return state->uart_port;
105 * This routine is used by the interrupt handler to schedule processing in
106 * the software interrupt portion of the driver.
108 void uart_write_wakeup(struct uart_port *port)
110 struct uart_state *state = port->state;
112 * This means you called this function _after_ the port was
113 * closed. No cookie for you.
116 tty_port_tty_wakeup(&state->port);
119 static void uart_stop(struct tty_struct *tty)
121 struct uart_state *state = tty->driver_data;
122 struct uart_port *port;
125 port = uart_port_lock(state, flags);
127 port->ops->stop_tx(port);
128 uart_port_unlock(port, flags);
131 static void __uart_start(struct tty_struct *tty)
133 struct uart_state *state = tty->driver_data;
134 struct uart_port *port = state->uart_port;
136 if (port && !uart_tx_stopped(port))
137 port->ops->start_tx(port);
140 static void uart_start(struct tty_struct *tty)
142 struct uart_state *state = tty->driver_data;
143 struct uart_port *port;
146 port = uart_port_lock(state, flags);
148 uart_port_unlock(port, flags);
152 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
157 spin_lock_irqsave(&port->lock, flags);
159 port->mctrl = (old & ~clear) | set;
160 if (old != port->mctrl)
161 port->ops->set_mctrl(port, port->mctrl);
162 spin_unlock_irqrestore(&port->lock, flags);
165 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
166 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
169 * Startup the port. This will be called once per open. All calls
170 * will be serialised by the per-port mutex.
172 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
175 struct uart_port *uport = uart_port_check(state);
179 if (uport->type == PORT_UNKNOWN)
183 * Make sure the device is in D0 state.
185 uart_change_pm(state, UART_PM_STATE_ON);
188 * Initialise and allocate the transmit and temporary
191 if (!state->xmit.buf) {
192 /* This is protected by the per port mutex */
193 page = get_zeroed_page(GFP_KERNEL);
197 state->xmit.buf = (unsigned char *) page;
198 uart_circ_clear(&state->xmit);
201 retval = uport->ops->startup(uport);
203 if (uart_console(uport) && uport->cons->cflag) {
204 tty->termios.c_cflag = uport->cons->cflag;
205 uport->cons->cflag = 0;
208 * Initialise the hardware port settings.
210 uart_change_speed(tty, state, NULL);
213 * Setup the RTS and DTR signals once the
214 * port is open and ready to respond.
216 if (init_hw && C_BAUD(tty))
217 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
221 * This is to allow setserial on this port. People may want to set
222 * port/irq/type and then reconfigure the port properly if it failed
225 if (retval && capable(CAP_SYS_ADMIN))
231 static int uart_startup(struct tty_struct *tty, struct uart_state *state,
234 struct tty_port *port = &state->port;
237 if (tty_port_initialized(port))
240 retval = uart_port_startup(tty, state, init_hw);
242 set_bit(TTY_IO_ERROR, &tty->flags);
248 * This routine will shutdown a serial port; interrupts are disabled, and
249 * DTR is dropped if the hangup on close termio flag is on. Calls to
250 * uart_shutdown are serialised by the per-port semaphore.
252 * uport == NULL if uart_port has already been removed
254 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
256 struct uart_port *uport = uart_port_check(state);
257 struct tty_port *port = &state->port;
260 * Set the TTY IO error marker
263 set_bit(TTY_IO_ERROR, &tty->flags);
265 if (tty_port_initialized(port)) {
266 tty_port_set_initialized(port, 0);
269 * Turn off DTR and RTS early.
271 if (uport && uart_console(uport) && tty)
272 uport->cons->cflag = tty->termios.c_cflag;
274 if (!tty || C_HUPCL(tty))
275 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
277 uart_port_shutdown(port);
281 * It's possible for shutdown to be called after suspend if we get
282 * a DCD drop (hangup) at just the right time. Clear suspended bit so
283 * we don't try to resume a port that has been shutdown.
285 tty_port_set_suspended(port, 0);
288 * Free the transmit buffer page.
290 if (state->xmit.buf) {
291 free_page((unsigned long)state->xmit.buf);
292 state->xmit.buf = NULL;
297 * uart_update_timeout - update per-port FIFO timeout.
298 * @port: uart_port structure describing the port
299 * @cflag: termios cflag value
300 * @baud: speed of the port
302 * Set the port FIFO timeout value. The @cflag value should
303 * reflect the actual hardware settings.
306 uart_update_timeout(struct uart_port *port, unsigned int cflag,
311 /* byte size and parity */
312 switch (cflag & CSIZE) {
333 * The total number of bits to be transmitted in the fifo.
335 bits = bits * port->fifosize;
338 * Figure the timeout to send the above number of bits.
339 * Add .02 seconds of slop
341 port->timeout = (HZ * bits) / baud + HZ/50;
344 EXPORT_SYMBOL(uart_update_timeout);
347 * uart_get_baud_rate - return baud rate for a particular port
348 * @port: uart_port structure describing the port in question.
349 * @termios: desired termios settings.
350 * @old: old termios (or NULL)
351 * @min: minimum acceptable baud rate
352 * @max: maximum acceptable baud rate
354 * Decode the termios structure into a numeric baud rate,
355 * taking account of the magic 38400 baud rate (with spd_*
356 * flags), and mapping the %B0 rate to 9600 baud.
358 * If the new baud rate is invalid, try the old termios setting.
359 * If it's still invalid, we try 9600 baud.
361 * Update the @termios structure to reflect the baud rate
362 * we're actually going to be using. Don't do this for the case
363 * where B0 is requested ("hang up").
366 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
367 struct ktermios *old, unsigned int min, unsigned int max)
371 unsigned int altbaud;
373 upf_t flags = port->flags & UPF_SPD_MASK;
393 for (try = 0; try < 2; try++) {
394 baud = tty_termios_baud_rate(termios);
397 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
400 if (try == 0 && baud == 38400)
404 * Special case: B0 rate.
411 if (baud >= min && baud <= max)
415 * Oops, the quotient was zero. Try again with
416 * the old baud rate if possible.
418 termios->c_cflag &= ~CBAUD;
420 baud = tty_termios_baud_rate(old);
422 tty_termios_encode_baud_rate(termios,
429 * As a last resort, if the range cannot be met then clip to
430 * the nearest chip supported rate.
434 tty_termios_encode_baud_rate(termios,
437 tty_termios_encode_baud_rate(termios,
441 /* Should never happen */
446 EXPORT_SYMBOL(uart_get_baud_rate);
449 * uart_get_divisor - return uart clock divisor
450 * @port: uart_port structure describing the port.
451 * @baud: desired baud rate
453 * Calculate the uart clock divisor for the port.
456 uart_get_divisor(struct uart_port *port, unsigned int baud)
461 * Old custom speed handling.
463 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
464 quot = port->custom_divisor;
466 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
471 EXPORT_SYMBOL(uart_get_divisor);
473 /* Caller holds port mutex */
474 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
475 struct ktermios *old_termios)
477 struct uart_port *uport = uart_port_check(state);
478 struct ktermios *termios;
482 * If we have no tty, termios, or the port does not exist,
483 * then we can't set the parameters for this port.
485 if (!tty || uport->type == PORT_UNKNOWN)
488 termios = &tty->termios;
489 uport->ops->set_termios(uport, termios, old_termios);
492 * Set modem status enables based on termios cflag
494 spin_lock_irq(&uport->lock);
495 if (termios->c_cflag & CRTSCTS)
496 uport->status |= UPSTAT_CTS_ENABLE;
498 uport->status &= ~UPSTAT_CTS_ENABLE;
500 if (termios->c_cflag & CLOCAL)
501 uport->status &= ~UPSTAT_DCD_ENABLE;
503 uport->status |= UPSTAT_DCD_ENABLE;
505 /* reset sw-assisted CTS flow control based on (possibly) new mode */
506 hw_stopped = uport->hw_stopped;
507 uport->hw_stopped = uart_softcts_mode(uport) &&
508 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
509 if (uport->hw_stopped) {
511 uport->ops->stop_tx(uport);
516 spin_unlock_irq(&uport->lock);
519 static int uart_put_char(struct tty_struct *tty, unsigned char c)
521 struct uart_state *state = tty->driver_data;
522 struct uart_port *port;
523 struct circ_buf *circ;
531 port = uart_port_lock(state, flags);
532 if (port && uart_circ_chars_free(circ) != 0) {
533 circ->buf[circ->head] = c;
534 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
537 uart_port_unlock(port, flags);
541 static void uart_flush_chars(struct tty_struct *tty)
546 static int uart_write(struct tty_struct *tty,
547 const unsigned char *buf, int count)
549 struct uart_state *state = tty->driver_data;
550 struct uart_port *port;
551 struct circ_buf *circ;
556 * This means you called this function _after_ the port was
557 * closed. No cookie for you.
568 port = uart_port_lock(state, flags);
570 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
575 memcpy(circ->buf + circ->head, buf, c);
576 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
583 uart_port_unlock(port, flags);
587 static int uart_write_room(struct tty_struct *tty)
589 struct uart_state *state = tty->driver_data;
590 struct uart_port *port;
594 port = uart_port_lock(state, flags);
595 ret = uart_circ_chars_free(&state->xmit);
596 uart_port_unlock(port, flags);
600 static int uart_chars_in_buffer(struct tty_struct *tty)
602 struct uart_state *state = tty->driver_data;
603 struct uart_port *port;
607 port = uart_port_lock(state, flags);
608 ret = uart_circ_chars_pending(&state->xmit);
609 uart_port_unlock(port, flags);
613 static void uart_flush_buffer(struct tty_struct *tty)
615 struct uart_state *state = tty->driver_data;
616 struct uart_port *port;
620 * This means you called this function _after_ the port was
621 * closed. No cookie for you.
628 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
630 port = uart_port_lock(state, flags);
633 uart_circ_clear(&state->xmit);
634 if (port->ops->flush_buffer)
635 port->ops->flush_buffer(port);
636 uart_port_unlock(port, flags);
637 tty_port_tty_wakeup(&state->port);
641 * This function is used to send a high-priority XON/XOFF character to
644 static void uart_send_xchar(struct tty_struct *tty, char ch)
646 struct uart_state *state = tty->driver_data;
647 struct uart_port *port;
650 port = uart_port_ref(state);
654 if (port->ops->send_xchar)
655 port->ops->send_xchar(port, ch);
657 spin_lock_irqsave(&port->lock, flags);
660 port->ops->start_tx(port);
661 spin_unlock_irqrestore(&port->lock, flags);
663 uart_port_deref(port);
666 static void uart_throttle(struct tty_struct *tty)
668 struct uart_state *state = tty->driver_data;
669 struct uart_port *port;
672 port = uart_port_ref(state);
677 mask |= UPSTAT_AUTOXOFF;
679 mask |= UPSTAT_AUTORTS;
681 if (port->status & mask) {
682 port->ops->throttle(port);
683 mask &= ~port->status;
686 if (mask & UPSTAT_AUTORTS)
687 uart_clear_mctrl(port, TIOCM_RTS);
689 if (mask & UPSTAT_AUTOXOFF)
690 uart_send_xchar(tty, STOP_CHAR(tty));
692 uart_port_deref(port);
695 static void uart_unthrottle(struct tty_struct *tty)
697 struct uart_state *state = tty->driver_data;
698 struct uart_port *port;
701 port = uart_port_ref(state);
706 mask |= UPSTAT_AUTOXOFF;
708 mask |= UPSTAT_AUTORTS;
710 if (port->status & mask) {
711 port->ops->unthrottle(port);
712 mask &= ~port->status;
715 if (mask & UPSTAT_AUTORTS)
716 uart_set_mctrl(port, TIOCM_RTS);
718 if (mask & UPSTAT_AUTOXOFF)
719 uart_send_xchar(tty, START_CHAR(tty));
721 uart_port_deref(port);
724 static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
726 struct uart_state *state = container_of(port, struct uart_state, port);
727 struct uart_port *uport;
730 memset(retinfo, 0, sizeof(*retinfo));
733 * Ensure the state we copy is consistent and no hardware changes
736 mutex_lock(&port->mutex);
737 uport = uart_port_check(state);
741 retinfo->type = uport->type;
742 retinfo->line = uport->line;
743 retinfo->port = uport->iobase;
744 if (HIGH_BITS_OFFSET)
745 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
746 retinfo->irq = uport->irq;
747 retinfo->flags = uport->flags;
748 retinfo->xmit_fifo_size = uport->fifosize;
749 retinfo->baud_base = uport->uartclk / 16;
750 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
751 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
752 ASYNC_CLOSING_WAIT_NONE :
753 jiffies_to_msecs(port->closing_wait) / 10;
754 retinfo->custom_divisor = uport->custom_divisor;
755 retinfo->hub6 = uport->hub6;
756 retinfo->io_type = uport->iotype;
757 retinfo->iomem_reg_shift = uport->regshift;
758 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
762 mutex_unlock(&port->mutex);
766 static int uart_get_info_user(struct tty_port *port,
767 struct serial_struct __user *retinfo)
769 struct serial_struct tmp;
771 if (uart_get_info(port, &tmp) < 0)
774 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
779 static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
780 struct uart_state *state,
781 struct serial_struct *new_info)
783 struct uart_port *uport = uart_port_check(state);
784 unsigned long new_port;
785 unsigned int change_irq, change_port, closing_wait;
786 unsigned int old_custom_divisor, close_delay;
787 upf_t old_flags, new_flags;
793 new_port = new_info->port;
794 if (HIGH_BITS_OFFSET)
795 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
797 new_info->irq = irq_canonicalize(new_info->irq);
798 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
799 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
800 ASYNC_CLOSING_WAIT_NONE :
801 msecs_to_jiffies(new_info->closing_wait * 10);
804 change_irq = !(uport->flags & UPF_FIXED_PORT)
805 && new_info->irq != uport->irq;
808 * Since changing the 'type' of the port changes its resource
809 * allocations, we should treat type changes the same as
812 change_port = !(uport->flags & UPF_FIXED_PORT)
813 && (new_port != uport->iobase ||
814 (unsigned long)new_info->iomem_base != uport->mapbase ||
815 new_info->hub6 != uport->hub6 ||
816 new_info->io_type != uport->iotype ||
817 new_info->iomem_reg_shift != uport->regshift ||
818 new_info->type != uport->type);
820 old_flags = uport->flags;
821 new_flags = new_info->flags;
822 old_custom_divisor = uport->custom_divisor;
824 if (!capable(CAP_SYS_ADMIN)) {
826 if (change_irq || change_port ||
827 (new_info->baud_base != uport->uartclk / 16) ||
828 (close_delay != port->close_delay) ||
829 (closing_wait != port->closing_wait) ||
830 (new_info->xmit_fifo_size &&
831 new_info->xmit_fifo_size != uport->fifosize) ||
832 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
834 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
835 (new_flags & UPF_USR_MASK));
836 uport->custom_divisor = new_info->custom_divisor;
841 * Ask the low level driver to verify the settings.
843 if (uport->ops->verify_port)
844 retval = uport->ops->verify_port(uport, new_info);
846 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
847 (new_info->baud_base < 9600))
853 if (change_port || change_irq) {
857 * Make sure that we are the sole user of this port.
859 if (tty_port_users(port) > 1)
863 * We need to shutdown the serial port at the old
864 * port/type/irq combination.
866 uart_shutdown(tty, state);
870 unsigned long old_iobase, old_mapbase;
871 unsigned int old_type, old_iotype, old_hub6, old_shift;
873 old_iobase = uport->iobase;
874 old_mapbase = uport->mapbase;
875 old_type = uport->type;
876 old_hub6 = uport->hub6;
877 old_iotype = uport->iotype;
878 old_shift = uport->regshift;
881 * Free and release old regions
883 if (old_type != PORT_UNKNOWN && uport->ops->release_port)
884 uport->ops->release_port(uport);
886 uport->iobase = new_port;
887 uport->type = new_info->type;
888 uport->hub6 = new_info->hub6;
889 uport->iotype = new_info->io_type;
890 uport->regshift = new_info->iomem_reg_shift;
891 uport->mapbase = (unsigned long)new_info->iomem_base;
894 * Claim and map the new regions
896 if (uport->type != PORT_UNKNOWN && uport->ops->request_port) {
897 retval = uport->ops->request_port(uport);
899 /* Always success - Jean II */
904 * If we fail to request resources for the
905 * new port, try to restore the old settings.
908 uport->iobase = old_iobase;
909 uport->type = old_type;
910 uport->hub6 = old_hub6;
911 uport->iotype = old_iotype;
912 uport->regshift = old_shift;
913 uport->mapbase = old_mapbase;
915 if (old_type != PORT_UNKNOWN) {
916 retval = uport->ops->request_port(uport);
918 * If we failed to restore the old settings,
922 uport->type = PORT_UNKNOWN;
930 /* Added to return the correct error -Ram Gupta */
936 uport->irq = new_info->irq;
937 if (!(uport->flags & UPF_FIXED_PORT))
938 uport->uartclk = new_info->baud_base * 16;
939 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
940 (new_flags & UPF_CHANGE_MASK);
941 uport->custom_divisor = new_info->custom_divisor;
942 port->close_delay = close_delay;
943 port->closing_wait = closing_wait;
944 if (new_info->xmit_fifo_size)
945 uport->fifosize = new_info->xmit_fifo_size;
946 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
950 if (uport->type == PORT_UNKNOWN)
952 if (tty_port_initialized(port)) {
953 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
954 old_custom_divisor != uport->custom_divisor) {
956 * If they're setting up a custom divisor or speed,
957 * instead of clearing it, then bitch about it. No
958 * need to rate-limit; it's CAP_SYS_ADMIN only.
960 if (uport->flags & UPF_SPD_MASK) {
961 dev_notice(uport->dev,
962 "%s sets custom speed on %s. This is deprecated.\n",
964 tty_name(port->tty));
966 uart_change_speed(tty, state, NULL);
969 retval = uart_startup(tty, state, 1);
977 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
978 struct serial_struct __user *newinfo)
980 struct serial_struct new_serial;
981 struct tty_port *port = &state->port;
984 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
988 * This semaphore protects port->count. It is also
989 * very useful to prevent opens. Also, take the
990 * port configuration semaphore to make sure that a
991 * module insertion/removal doesn't change anything
994 mutex_lock(&port->mutex);
995 retval = uart_set_info(tty, port, state, &new_serial);
996 mutex_unlock(&port->mutex);
1001 * uart_get_lsr_info - get line status register info
1002 * @tty: tty associated with the UART
1003 * @state: UART being queried
1004 * @value: returned modem value
1006 static int uart_get_lsr_info(struct tty_struct *tty,
1007 struct uart_state *state, unsigned int __user *value)
1009 struct uart_port *uport = uart_port_check(state);
1010 unsigned int result;
1012 result = uport->ops->tx_empty(uport);
1015 * If we're about to load something into the transmit
1016 * register, we'll pretend the transmitter isn't empty to
1017 * avoid a race condition (depending on when the transmit
1018 * interrupt happens).
1020 if (uport->x_char ||
1021 ((uart_circ_chars_pending(&state->xmit) > 0) &&
1022 !uart_tx_stopped(uport)))
1023 result &= ~TIOCSER_TEMT;
1025 return put_user(result, value);
1028 static int uart_tiocmget(struct tty_struct *tty)
1030 struct uart_state *state = tty->driver_data;
1031 struct tty_port *port = &state->port;
1032 struct uart_port *uport;
1035 mutex_lock(&port->mutex);
1036 uport = uart_port_check(state);
1040 if (!tty_io_error(tty)) {
1041 result = uport->mctrl;
1042 spin_lock_irq(&uport->lock);
1043 result |= uport->ops->get_mctrl(uport);
1044 spin_unlock_irq(&uport->lock);
1047 mutex_unlock(&port->mutex);
1052 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
1054 struct uart_state *state = tty->driver_data;
1055 struct tty_port *port = &state->port;
1056 struct uart_port *uport;
1059 mutex_lock(&port->mutex);
1060 uport = uart_port_check(state);
1064 if (!tty_io_error(tty)) {
1065 uart_update_mctrl(uport, set, clear);
1069 mutex_unlock(&port->mutex);
1073 static int uart_break_ctl(struct tty_struct *tty, int break_state)
1075 struct uart_state *state = tty->driver_data;
1076 struct tty_port *port = &state->port;
1077 struct uart_port *uport;
1080 mutex_lock(&port->mutex);
1081 uport = uart_port_check(state);
1085 if (uport->type != PORT_UNKNOWN)
1086 uport->ops->break_ctl(uport, break_state);
1089 mutex_unlock(&port->mutex);
1093 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1095 struct tty_port *port = &state->port;
1096 struct uart_port *uport;
1099 if (!capable(CAP_SYS_ADMIN))
1103 * Take the per-port semaphore. This prevents count from
1104 * changing, and hence any extra opens of the port while
1105 * we're auto-configuring.
1107 if (mutex_lock_interruptible(&port->mutex))
1108 return -ERESTARTSYS;
1110 uport = uart_port_check(state);
1117 if (tty_port_users(port) == 1) {
1118 uart_shutdown(tty, state);
1121 * If we already have a port type configured,
1122 * we must release its resources.
1124 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
1125 uport->ops->release_port(uport);
1127 flags = UART_CONFIG_TYPE;
1128 if (uport->flags & UPF_AUTO_IRQ)
1129 flags |= UART_CONFIG_IRQ;
1132 * This will claim the ports resources if
1135 uport->ops->config_port(uport, flags);
1137 ret = uart_startup(tty, state, 1);
1142 mutex_unlock(&port->mutex);
1146 static void uart_enable_ms(struct uart_port *uport)
1149 * Force modem status interrupts on
1151 if (uport->ops->enable_ms)
1152 uport->ops->enable_ms(uport);
1156 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1157 * - mask passed in arg for lines of interest
1158 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1159 * Caller should use TIOCGICOUNT to see which one it was
1161 * FIXME: This wants extracting into a common all driver implementation
1162 * of TIOCMWAIT using tty_port.
1164 static int uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1166 struct uart_port *uport;
1167 struct tty_port *port = &state->port;
1168 DECLARE_WAITQUEUE(wait, current);
1169 struct uart_icount cprev, cnow;
1173 * note the counters on entry
1175 uport = uart_port_ref(state);
1178 spin_lock_irq(&uport->lock);
1179 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1180 uart_enable_ms(uport);
1181 spin_unlock_irq(&uport->lock);
1183 add_wait_queue(&port->delta_msr_wait, &wait);
1185 spin_lock_irq(&uport->lock);
1186 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1187 spin_unlock_irq(&uport->lock);
1189 set_current_state(TASK_INTERRUPTIBLE);
1191 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1192 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1193 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1194 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1201 /* see if a signal did it */
1202 if (signal_pending(current)) {
1209 __set_current_state(TASK_RUNNING);
1210 remove_wait_queue(&port->delta_msr_wait, &wait);
1211 uart_port_deref(uport);
1217 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1218 * Return: write counters to the user passed counter struct
1219 * NB: both 1->0 and 0->1 transitions are counted except for
1220 * RI where only 0->1 is counted.
1222 static int uart_get_icount(struct tty_struct *tty,
1223 struct serial_icounter_struct *icount)
1225 struct uart_state *state = tty->driver_data;
1226 struct uart_icount cnow;
1227 struct uart_port *uport;
1229 uport = uart_port_ref(state);
1232 spin_lock_irq(&uport->lock);
1233 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1234 spin_unlock_irq(&uport->lock);
1235 uart_port_deref(uport);
1237 icount->cts = cnow.cts;
1238 icount->dsr = cnow.dsr;
1239 icount->rng = cnow.rng;
1240 icount->dcd = cnow.dcd;
1241 icount->rx = cnow.rx;
1242 icount->tx = cnow.tx;
1243 icount->frame = cnow.frame;
1244 icount->overrun = cnow.overrun;
1245 icount->parity = cnow.parity;
1246 icount->brk = cnow.brk;
1247 icount->buf_overrun = cnow.buf_overrun;
1252 static int uart_get_rs485_config(struct uart_port *port,
1253 struct serial_rs485 __user *rs485)
1255 unsigned long flags;
1256 struct serial_rs485 aux;
1258 spin_lock_irqsave(&port->lock, flags);
1260 spin_unlock_irqrestore(&port->lock, flags);
1262 if (copy_to_user(rs485, &aux, sizeof(aux)))
1268 static int uart_set_rs485_config(struct uart_port *port,
1269 struct serial_rs485 __user *rs485_user)
1271 struct serial_rs485 rs485;
1273 unsigned long flags;
1275 if (!port->rs485_config)
1276 return -ENOIOCTLCMD;
1278 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1281 spin_lock_irqsave(&port->lock, flags);
1282 ret = port->rs485_config(port, &rs485);
1283 spin_unlock_irqrestore(&port->lock, flags);
1287 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1294 * Called via sys_ioctl. We can use spin_lock_irq() here.
1297 uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
1299 struct uart_state *state = tty->driver_data;
1300 struct tty_port *port = &state->port;
1301 struct uart_port *uport;
1302 void __user *uarg = (void __user *)arg;
1303 int ret = -ENOIOCTLCMD;
1307 * These ioctls don't rely on the hardware to be present.
1311 ret = uart_get_info_user(port, uarg);
1315 down_write(&tty->termios_rwsem);
1316 ret = uart_set_info_user(tty, state, uarg);
1317 up_write(&tty->termios_rwsem);
1321 down_write(&tty->termios_rwsem);
1322 ret = uart_do_autoconfig(tty, state);
1323 up_write(&tty->termios_rwsem);
1326 case TIOCSERGWILD: /* obsolete */
1327 case TIOCSERSWILD: /* obsolete */
1332 if (ret != -ENOIOCTLCMD)
1335 if (tty_io_error(tty)) {
1341 * The following should only be used when hardware is present.
1345 ret = uart_wait_modem_status(state, arg);
1349 if (ret != -ENOIOCTLCMD)
1352 mutex_lock(&port->mutex);
1353 uport = uart_port_check(state);
1355 if (!uport || tty_io_error(tty)) {
1361 * All these rely on hardware being present and need to be
1362 * protected against the tty being hung up.
1366 case TIOCSERGETLSR: /* Get line status register */
1367 ret = uart_get_lsr_info(tty, state, uarg);
1371 ret = uart_get_rs485_config(uport, uarg);
1375 ret = uart_set_rs485_config(uport, uarg);
1378 if (uport->ops->ioctl)
1379 ret = uport->ops->ioctl(uport, cmd, arg);
1383 mutex_unlock(&port->mutex);
1388 static void uart_set_ldisc(struct tty_struct *tty)
1390 struct uart_state *state = tty->driver_data;
1391 struct uart_port *uport;
1393 mutex_lock(&state->port.mutex);
1394 uport = uart_port_check(state);
1395 if (uport && uport->ops->set_ldisc)
1396 uport->ops->set_ldisc(uport, &tty->termios);
1397 mutex_unlock(&state->port.mutex);
1400 static void uart_set_termios(struct tty_struct *tty,
1401 struct ktermios *old_termios)
1403 struct uart_state *state = tty->driver_data;
1404 struct uart_port *uport;
1405 unsigned int cflag = tty->termios.c_cflag;
1406 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1407 bool sw_changed = false;
1409 mutex_lock(&state->port.mutex);
1410 uport = uart_port_check(state);
1415 * Drivers doing software flow control also need to know
1416 * about changes to these input settings.
1418 if (uport->flags & UPF_SOFT_FLOW) {
1419 iflag_mask |= IXANY|IXON|IXOFF;
1421 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1422 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1426 * These are the bits that are used to setup various
1427 * flags in the low level driver. We can ignore the Bfoo
1428 * bits in c_cflag; c_[io]speed will always be set
1429 * appropriately by set_termios() in tty_ioctl.c
1431 if ((cflag ^ old_termios->c_cflag) == 0 &&
1432 tty->termios.c_ospeed == old_termios->c_ospeed &&
1433 tty->termios.c_ispeed == old_termios->c_ispeed &&
1434 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1439 uart_change_speed(tty, state, old_termios);
1440 /* reload cflag from termios; port driver may have overriden flags */
1441 cflag = tty->termios.c_cflag;
1443 /* Handle transition to B0 status */
1444 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1445 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1446 /* Handle transition away from B0 status */
1447 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1448 unsigned int mask = TIOCM_DTR;
1449 if (!(cflag & CRTSCTS) || !tty_throttled(tty))
1451 uart_set_mctrl(uport, mask);
1454 mutex_unlock(&state->port.mutex);
1458 * Calls to uart_close() are serialised via the tty_lock in
1459 * drivers/tty/tty_io.c:tty_release()
1460 * drivers/tty/tty_io.c:do_tty_hangup()
1462 static void uart_close(struct tty_struct *tty, struct file *filp)
1464 struct uart_state *state = tty->driver_data;
1465 struct tty_port *port;
1468 struct uart_driver *drv = tty->driver->driver_state;
1470 state = drv->state + tty->index;
1471 port = &state->port;
1472 spin_lock_irq(&port->lock);
1474 spin_unlock_irq(&port->lock);
1478 port = &state->port;
1479 pr_debug("uart_close(%d) called\n", tty->index);
1481 tty_port_close(tty->port, tty, filp);
1484 static void uart_tty_port_shutdown(struct tty_port *port)
1486 struct uart_state *state = container_of(port, struct uart_state, port);
1487 struct uart_port *uport = uart_port_check(state);
1490 * At this point, we stop accepting input. To do this, we
1491 * disable the receive line status interrupts.
1493 if (WARN(!uport, "detached port still initialized!\n"))
1496 spin_lock_irq(&uport->lock);
1497 uport->ops->stop_rx(uport);
1498 spin_unlock_irq(&uport->lock);
1500 uart_port_shutdown(port);
1503 * It's possible for shutdown to be called after suspend if we get
1504 * a DCD drop (hangup) at just the right time. Clear suspended bit so
1505 * we don't try to resume a port that has been shutdown.
1507 tty_port_set_suspended(port, 0);
1509 uart_change_pm(state, UART_PM_STATE_OFF);
1513 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1515 struct uart_state *state = tty->driver_data;
1516 struct uart_port *port;
1517 unsigned long char_time, expire;
1519 port = uart_port_ref(state);
1523 if (port->type == PORT_UNKNOWN || port->fifosize == 0) {
1524 uart_port_deref(port);
1529 * Set the check interval to be 1/5 of the estimated time to
1530 * send a single character, and make it at least 1. The check
1531 * interval should also be less than the timeout.
1533 * Note: we have to use pretty tight timings here to satisfy
1536 char_time = (port->timeout - HZ/50) / port->fifosize;
1537 char_time = char_time / 5;
1540 if (timeout && timeout < char_time)
1541 char_time = timeout;
1544 * If the transmitter hasn't cleared in twice the approximate
1545 * amount of time to send the entire FIFO, it probably won't
1546 * ever clear. This assumes the UART isn't doing flow
1547 * control, which is currently the case. Hence, if it ever
1548 * takes longer than port->timeout, this is probably due to a
1549 * UART bug of some kind. So, we clamp the timeout parameter at
1552 if (timeout == 0 || timeout > 2 * port->timeout)
1553 timeout = 2 * port->timeout;
1555 expire = jiffies + timeout;
1557 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1558 port->line, jiffies, expire);
1561 * Check whether the transmitter is empty every 'char_time'.
1562 * 'timeout' / 'expire' give us the maximum amount of time
1565 while (!port->ops->tx_empty(port)) {
1566 msleep_interruptible(jiffies_to_msecs(char_time));
1567 if (signal_pending(current))
1569 if (time_after(jiffies, expire))
1572 uart_port_deref(port);
1576 * Calls to uart_hangup() are serialised by the tty_lock in
1577 * drivers/tty/tty_io.c:do_tty_hangup()
1578 * This runs from a workqueue and can sleep for a _short_ time only.
1580 static void uart_hangup(struct tty_struct *tty)
1582 struct uart_state *state = tty->driver_data;
1583 struct tty_port *port = &state->port;
1584 struct uart_port *uport;
1585 unsigned long flags;
1587 pr_debug("uart_hangup(%d)\n", tty->index);
1589 mutex_lock(&port->mutex);
1590 uport = uart_port_check(state);
1591 WARN(!uport, "hangup of detached port!\n");
1593 if (tty_port_active(port)) {
1594 uart_flush_buffer(tty);
1595 uart_shutdown(tty, state);
1596 spin_lock_irqsave(&port->lock, flags);
1598 spin_unlock_irqrestore(&port->lock, flags);
1599 tty_port_set_active(port, 0);
1600 tty_port_tty_set(port, NULL);
1601 if (uport && !uart_console(uport))
1602 uart_change_pm(state, UART_PM_STATE_OFF);
1603 wake_up_interruptible(&port->open_wait);
1604 wake_up_interruptible(&port->delta_msr_wait);
1606 mutex_unlock(&port->mutex);
1609 /* uport == NULL if uart_port has already been removed */
1610 static void uart_port_shutdown(struct tty_port *port)
1612 struct uart_state *state = container_of(port, struct uart_state, port);
1613 struct uart_port *uport = uart_port_check(state);
1616 * clear delta_msr_wait queue to avoid mem leaks: we may free
1617 * the irq here so the queue might never be woken up. Note
1618 * that we won't end up waiting on delta_msr_wait again since
1619 * any outstanding file descriptors should be pointing at
1620 * hung_up_tty_fops now.
1622 wake_up_interruptible(&port->delta_msr_wait);
1625 * Free the IRQ and disable the port.
1628 uport->ops->shutdown(uport);
1631 * Ensure that the IRQ handler isn't running on another CPU.
1634 synchronize_irq(uport->irq);
1637 static int uart_carrier_raised(struct tty_port *port)
1639 struct uart_state *state = container_of(port, struct uart_state, port);
1640 struct uart_port *uport;
1643 uport = uart_port_ref(state);
1645 * Should never observe uport == NULL since checks for hangup should
1646 * abort the tty_port_block_til_ready() loop before checking for carrier
1647 * raised -- but report carrier raised if it does anyway so open will
1648 * continue and not sleep
1650 if (WARN_ON(!uport))
1652 spin_lock_irq(&uport->lock);
1653 uart_enable_ms(uport);
1654 mctrl = uport->ops->get_mctrl(uport);
1655 spin_unlock_irq(&uport->lock);
1656 uart_port_deref(uport);
1657 if (mctrl & TIOCM_CAR)
1662 static void uart_dtr_rts(struct tty_port *port, int onoff)
1664 struct uart_state *state = container_of(port, struct uart_state, port);
1665 struct uart_port *uport;
1667 uport = uart_port_ref(state);
1672 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1674 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1676 uart_port_deref(uport);
1680 * Calls to uart_open are serialised by the tty_lock in
1681 * drivers/tty/tty_io.c:tty_open()
1682 * Note that if this fails, then uart_close() _will_ be called.
1684 * In time, we want to scrap the "opening nonpresent ports"
1685 * behaviour and implement an alternative way for setserial
1686 * to set base addresses/ports/types. This will allow us to
1687 * get rid of a certain amount of extra tests.
1689 static int uart_open(struct tty_struct *tty, struct file *filp)
1691 struct uart_driver *drv = tty->driver->driver_state;
1692 int retval, line = tty->index;
1693 struct uart_state *state = drv->state + line;
1695 tty->driver_data = state;
1697 retval = tty_port_open(&state->port, tty, filp);
1704 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1706 struct uart_state *state = container_of(port, struct uart_state, port);
1707 struct uart_port *uport;
1709 uport = uart_port_check(state);
1710 if (!uport || uport->flags & UPF_DEAD)
1713 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
1716 * Start up the serial port.
1718 return uart_startup(tty, state, 0);
1721 static const char *uart_type(struct uart_port *port)
1723 const char *str = NULL;
1725 if (port->ops->type)
1726 str = port->ops->type(port);
1734 #ifdef CONFIG_PROC_FS
1736 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1738 struct uart_state *state = drv->state + i;
1739 struct tty_port *port = &state->port;
1740 enum uart_pm_state pm_state;
1741 struct uart_port *uport;
1743 unsigned int status;
1746 mutex_lock(&port->mutex);
1747 uport = uart_port_check(state);
1751 mmio = uport->iotype >= UPIO_MEM;
1752 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1753 uport->line, uart_type(uport),
1754 mmio ? "mmio:0x" : "port:",
1755 mmio ? (unsigned long long)uport->mapbase
1756 : (unsigned long long)uport->iobase,
1759 if (uport->type == PORT_UNKNOWN) {
1764 if (capable(CAP_SYS_ADMIN)) {
1765 pm_state = state->pm_state;
1766 if (pm_state != UART_PM_STATE_ON)
1767 uart_change_pm(state, UART_PM_STATE_ON);
1768 spin_lock_irq(&uport->lock);
1769 status = uport->ops->get_mctrl(uport);
1770 spin_unlock_irq(&uport->lock);
1771 if (pm_state != UART_PM_STATE_ON)
1772 uart_change_pm(state, pm_state);
1774 seq_printf(m, " tx:%d rx:%d",
1775 uport->icount.tx, uport->icount.rx);
1776 if (uport->icount.frame)
1777 seq_printf(m, " fe:%d", uport->icount.frame);
1778 if (uport->icount.parity)
1779 seq_printf(m, " pe:%d", uport->icount.parity);
1780 if (uport->icount.brk)
1781 seq_printf(m, " brk:%d", uport->icount.brk);
1782 if (uport->icount.overrun)
1783 seq_printf(m, " oe:%d", uport->icount.overrun);
1785 #define INFOBIT(bit, str) \
1786 if (uport->mctrl & (bit)) \
1787 strncat(stat_buf, (str), sizeof(stat_buf) - \
1788 strlen(stat_buf) - 2)
1789 #define STATBIT(bit, str) \
1790 if (status & (bit)) \
1791 strncat(stat_buf, (str), sizeof(stat_buf) - \
1792 strlen(stat_buf) - 2)
1796 INFOBIT(TIOCM_RTS, "|RTS");
1797 STATBIT(TIOCM_CTS, "|CTS");
1798 INFOBIT(TIOCM_DTR, "|DTR");
1799 STATBIT(TIOCM_DSR, "|DSR");
1800 STATBIT(TIOCM_CAR, "|CD");
1801 STATBIT(TIOCM_RNG, "|RI");
1805 seq_puts(m, stat_buf);
1811 mutex_unlock(&port->mutex);
1814 static int uart_proc_show(struct seq_file *m, void *v)
1816 struct tty_driver *ttydrv = m->private;
1817 struct uart_driver *drv = ttydrv->driver_state;
1820 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
1821 for (i = 0; i < drv->nr; i++)
1822 uart_line_info(m, drv, i);
1826 static int uart_proc_open(struct inode *inode, struct file *file)
1828 return single_open(file, uart_proc_show, PDE_DATA(inode));
1831 static const struct file_operations uart_proc_fops = {
1832 .owner = THIS_MODULE,
1833 .open = uart_proc_open,
1835 .llseek = seq_lseek,
1836 .release = single_release,
1840 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1842 * uart_console_write - write a console message to a serial port
1843 * @port: the port to write the message
1844 * @s: array of characters
1845 * @count: number of characters in string to write
1846 * @putchar: function to write character to port
1848 void uart_console_write(struct uart_port *port, const char *s,
1850 void (*putchar)(struct uart_port *, int))
1854 for (i = 0; i < count; i++, s++) {
1856 putchar(port, '\r');
1860 EXPORT_SYMBOL_GPL(uart_console_write);
1863 * Check whether an invalid uart number has been specified, and
1864 * if so, search for the first available port that does have
1867 struct uart_port * __init
1868 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1870 int idx = co->index;
1872 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1873 ports[idx].membase == NULL))
1874 for (idx = 0; idx < nr; idx++)
1875 if (ports[idx].iobase != 0 ||
1876 ports[idx].membase != NULL)
1885 * uart_parse_earlycon - Parse earlycon options
1886 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1887 * @iotype: ptr for decoded iotype (out)
1888 * @addr: ptr for decoded mapbase/iobase (out)
1889 * @options: ptr for <options> field; NULL if not present (out)
1891 * Decodes earlycon kernel command line parameters of the form
1892 * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1893 * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1896 * earlycon=<name>,0x<addr>,<options>
1897 * console=<name>,0x<addr>,<options>
1898 * is also accepted; the returned @iotype will be UPIO_MEM.
1900 * Returns 0 on success or -EINVAL on failure
1902 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
1905 if (strncmp(p, "mmio,", 5) == 0) {
1908 } else if (strncmp(p, "mmio16,", 7) == 0) {
1909 *iotype = UPIO_MEM16;
1911 } else if (strncmp(p, "mmio32,", 7) == 0) {
1912 *iotype = UPIO_MEM32;
1914 } else if (strncmp(p, "mmio32be,", 9) == 0) {
1915 *iotype = UPIO_MEM32BE;
1917 } else if (strncmp(p, "mmio32native,", 13) == 0) {
1918 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
1919 UPIO_MEM32BE : UPIO_MEM32;
1921 } else if (strncmp(p, "io,", 3) == 0) {
1922 *iotype = UPIO_PORT;
1924 } else if (strncmp(p, "0x", 2) == 0) {
1931 * Before you replace it with kstrtoull(), think about options separator
1932 * (',') it will not tolerate
1934 *addr = simple_strtoull(p, NULL, 0);
1942 EXPORT_SYMBOL_GPL(uart_parse_earlycon);
1945 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1946 * @options: pointer to option string
1947 * @baud: pointer to an 'int' variable for the baud rate.
1948 * @parity: pointer to an 'int' variable for the parity.
1949 * @bits: pointer to an 'int' variable for the number of data bits.
1950 * @flow: pointer to an 'int' variable for the flow control character.
1952 * uart_parse_options decodes a string containing the serial console
1953 * options. The format of the string is <baud><parity><bits><flow>,
1957 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1961 *baud = simple_strtoul(s, NULL, 10);
1962 while (*s >= '0' && *s <= '9')
1971 EXPORT_SYMBOL_GPL(uart_parse_options);
1974 * uart_set_options - setup the serial console parameters
1975 * @port: pointer to the serial ports uart_port structure
1976 * @co: console pointer
1978 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1979 * @bits: number of data bits
1980 * @flow: flow control character - 'r' (rts)
1983 uart_set_options(struct uart_port *port, struct console *co,
1984 int baud, int parity, int bits, int flow)
1986 struct ktermios termios;
1987 static struct ktermios dummy;
1990 * Ensure that the serial console lock is initialised
1992 * If this port is a console, then the spinlock is already
1995 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1996 spin_lock_init(&port->lock);
1997 lockdep_set_class(&port->lock, &port_lock_key);
2000 memset(&termios, 0, sizeof(struct ktermios));
2002 termios.c_cflag |= CREAD | HUPCL | CLOCAL;
2003 tty_termios_encode_baud_rate(&termios, baud, baud);
2006 termios.c_cflag |= CS7;
2008 termios.c_cflag |= CS8;
2012 termios.c_cflag |= PARODD;
2015 termios.c_cflag |= PARENB;
2020 termios.c_cflag |= CRTSCTS;
2023 * some uarts on other side don't support no flow control.
2024 * So we set * DTR in host uart to make them happy
2026 port->mctrl |= TIOCM_DTR;
2028 port->ops->set_termios(port, &termios, &dummy);
2030 * Allow the setting of the UART parameters with a NULL console
2034 co->cflag = termios.c_cflag;
2038 EXPORT_SYMBOL_GPL(uart_set_options);
2039 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
2042 * uart_change_pm - set power state of the port
2044 * @state: port descriptor
2045 * @pm_state: new state
2047 * Locking: port->mutex has to be held
2049 static void uart_change_pm(struct uart_state *state,
2050 enum uart_pm_state pm_state)
2052 struct uart_port *port = uart_port_check(state);
2054 if (state->pm_state != pm_state) {
2055 if (port && port->ops->pm)
2056 port->ops->pm(port, pm_state, state->pm_state);
2057 state->pm_state = pm_state;
2062 struct uart_port *port;
2063 struct uart_driver *driver;
2066 static int serial_match_port(struct device *dev, void *data)
2068 struct uart_match *match = data;
2069 struct tty_driver *tty_drv = match->driver->tty_driver;
2070 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
2073 return dev->devt == devt; /* Actually, only one tty per port */
2076 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
2078 struct uart_state *state = drv->state + uport->line;
2079 struct tty_port *port = &state->port;
2080 struct device *tty_dev;
2081 struct uart_match match = {uport, drv};
2083 mutex_lock(&port->mutex);
2085 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2086 if (tty_dev && device_may_wakeup(tty_dev)) {
2087 if (!enable_irq_wake(uport->irq))
2088 uport->irq_wake = 1;
2089 put_device(tty_dev);
2090 mutex_unlock(&port->mutex);
2093 put_device(tty_dev);
2095 /* Nothing to do if the console is not suspending */
2096 if (!console_suspend_enabled && uart_console(uport))
2099 uport->suspended = 1;
2101 if (tty_port_initialized(port)) {
2102 const struct uart_ops *ops = uport->ops;
2105 tty_port_set_suspended(port, 1);
2106 tty_port_set_initialized(port, 0);
2108 spin_lock_irq(&uport->lock);
2109 ops->stop_tx(uport);
2110 ops->set_mctrl(uport, 0);
2111 ops->stop_rx(uport);
2112 spin_unlock_irq(&uport->lock);
2115 * Wait for the transmitter to empty.
2117 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2120 dev_err(uport->dev, "%s: Unable to drain transmitter\n",
2123 ops->shutdown(uport);
2127 * Disable the console device before suspending.
2129 if (uart_console(uport))
2130 console_stop(uport->cons);
2132 uart_change_pm(state, UART_PM_STATE_OFF);
2134 mutex_unlock(&port->mutex);
2139 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2141 struct uart_state *state = drv->state + uport->line;
2142 struct tty_port *port = &state->port;
2143 struct device *tty_dev;
2144 struct uart_match match = {uport, drv};
2145 struct ktermios termios;
2147 mutex_lock(&port->mutex);
2149 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2150 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2151 if (uport->irq_wake) {
2152 disable_irq_wake(uport->irq);
2153 uport->irq_wake = 0;
2155 put_device(tty_dev);
2156 mutex_unlock(&port->mutex);
2159 put_device(tty_dev);
2160 uport->suspended = 0;
2163 * Re-enable the console device after suspending.
2165 if (uart_console(uport)) {
2167 * First try to use the console cflag setting.
2169 memset(&termios, 0, sizeof(struct ktermios));
2170 termios.c_cflag = uport->cons->cflag;
2173 * If that's unset, use the tty termios setting.
2175 if (port->tty && termios.c_cflag == 0)
2176 termios = port->tty->termios;
2178 if (console_suspend_enabled)
2179 uart_change_pm(state, UART_PM_STATE_ON);
2180 uport->ops->set_termios(uport, &termios, NULL);
2181 if (console_suspend_enabled)
2182 console_start(uport->cons);
2185 if (tty_port_suspended(port)) {
2186 const struct uart_ops *ops = uport->ops;
2189 uart_change_pm(state, UART_PM_STATE_ON);
2190 spin_lock_irq(&uport->lock);
2191 ops->set_mctrl(uport, 0);
2192 spin_unlock_irq(&uport->lock);
2193 if (console_suspend_enabled || !uart_console(uport)) {
2194 /* Protected by port mutex for now */
2195 struct tty_struct *tty = port->tty;
2196 ret = ops->startup(uport);
2199 uart_change_speed(tty, state, NULL);
2200 spin_lock_irq(&uport->lock);
2201 ops->set_mctrl(uport, uport->mctrl);
2202 ops->start_tx(uport);
2203 spin_unlock_irq(&uport->lock);
2204 tty_port_set_initialized(port, 1);
2207 * Failed to resume - maybe hardware went away?
2208 * Clear the "initialized" flag so we won't try
2209 * to call the low level drivers shutdown method.
2211 uart_shutdown(tty, state);
2215 tty_port_set_suspended(port, 0);
2218 mutex_unlock(&port->mutex);
2224 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2228 switch (port->iotype) {
2230 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2233 snprintf(address, sizeof(address),
2234 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2242 snprintf(address, sizeof(address),
2243 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2246 strlcpy(address, "*unknown*", sizeof(address));
2250 pr_info("%s%s%s at %s (irq = %d, base_baud = %d) is a %s\n",
2251 port->dev ? dev_name(port->dev) : "",
2252 port->dev ? ": " : "",
2254 address, port->irq, port->uartclk / 16, uart_type(port));
2258 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2259 struct uart_port *port)
2264 * If there isn't a port here, don't do anything further.
2266 if (!port->iobase && !port->mapbase && !port->membase)
2270 * Now do the auto configuration stuff. Note that config_port
2271 * is expected to claim the resources and map the port for us.
2274 if (port->flags & UPF_AUTO_IRQ)
2275 flags |= UART_CONFIG_IRQ;
2276 if (port->flags & UPF_BOOT_AUTOCONF) {
2277 if (!(port->flags & UPF_FIXED_TYPE)) {
2278 port->type = PORT_UNKNOWN;
2279 flags |= UART_CONFIG_TYPE;
2281 port->ops->config_port(port, flags);
2284 if (port->type != PORT_UNKNOWN) {
2285 unsigned long flags;
2287 uart_report_port(drv, port);
2289 /* Power up port for set_mctrl() */
2290 uart_change_pm(state, UART_PM_STATE_ON);
2293 * Ensure that the modem control lines are de-activated.
2294 * keep the DTR setting that is set in uart_set_options()
2295 * We probably don't need a spinlock around this, but
2297 spin_lock_irqsave(&port->lock, flags);
2298 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2299 spin_unlock_irqrestore(&port->lock, flags);
2302 * If this driver supports console, and it hasn't been
2303 * successfully registered yet, try to re-register it.
2304 * It may be that the port was not available.
2306 if (port->cons && !(port->cons->flags & CON_ENABLED))
2307 register_console(port->cons);
2310 * Power down all ports by default, except the
2311 * console if we have one.
2313 if (!uart_console(port))
2314 uart_change_pm(state, UART_PM_STATE_OFF);
2318 #ifdef CONFIG_CONSOLE_POLL
2320 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2322 struct uart_driver *drv = driver->driver_state;
2323 struct uart_state *state = drv->state + line;
2324 struct tty_port *tport;
2325 struct uart_port *port;
2332 tport = &state->port;
2333 mutex_lock(&tport->mutex);
2335 port = uart_port_check(state);
2336 if (!port || !(port->ops->poll_get_char && port->ops->poll_put_char)) {
2341 if (port->ops->poll_init) {
2343 * We don't set initialized as we only initialized the hw,
2344 * e.g. state->xmit is still uninitialized.
2346 if (!tty_port_initialized(tport))
2347 ret = port->ops->poll_init(port);
2350 if (!ret && options) {
2351 uart_parse_options(options, &baud, &parity, &bits, &flow);
2352 ret = uart_set_options(port, NULL, baud, parity, bits, flow);
2355 mutex_unlock(&tport->mutex);
2359 static int uart_poll_get_char(struct tty_driver *driver, int line)
2361 struct uart_driver *drv = driver->driver_state;
2362 struct uart_state *state = drv->state + line;
2363 struct uart_port *port;
2366 port = uart_port_ref(state);
2368 ret = port->ops->poll_get_char(port);
2369 uart_port_deref(port);
2375 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2377 struct uart_driver *drv = driver->driver_state;
2378 struct uart_state *state = drv->state + line;
2379 struct uart_port *port;
2381 port = uart_port_ref(state);
2386 port->ops->poll_put_char(port, '\r');
2387 port->ops->poll_put_char(port, ch);
2388 uart_port_deref(port);
2392 static const struct tty_operations uart_ops = {
2394 .close = uart_close,
2395 .write = uart_write,
2396 .put_char = uart_put_char,
2397 .flush_chars = uart_flush_chars,
2398 .write_room = uart_write_room,
2399 .chars_in_buffer= uart_chars_in_buffer,
2400 .flush_buffer = uart_flush_buffer,
2401 .ioctl = uart_ioctl,
2402 .throttle = uart_throttle,
2403 .unthrottle = uart_unthrottle,
2404 .send_xchar = uart_send_xchar,
2405 .set_termios = uart_set_termios,
2406 .set_ldisc = uart_set_ldisc,
2408 .start = uart_start,
2409 .hangup = uart_hangup,
2410 .break_ctl = uart_break_ctl,
2411 .wait_until_sent= uart_wait_until_sent,
2412 #ifdef CONFIG_PROC_FS
2413 .proc_fops = &uart_proc_fops,
2415 .tiocmget = uart_tiocmget,
2416 .tiocmset = uart_tiocmset,
2417 .get_icount = uart_get_icount,
2418 #ifdef CONFIG_CONSOLE_POLL
2419 .poll_init = uart_poll_init,
2420 .poll_get_char = uart_poll_get_char,
2421 .poll_put_char = uart_poll_put_char,
2425 static const struct tty_port_operations uart_port_ops = {
2426 .carrier_raised = uart_carrier_raised,
2427 .dtr_rts = uart_dtr_rts,
2428 .activate = uart_port_activate,
2429 .shutdown = uart_tty_port_shutdown,
2433 * uart_register_driver - register a driver with the uart core layer
2434 * @drv: low level driver structure
2436 * Register a uart driver with the core driver. We in turn register
2437 * with the tty layer, and initialise the core driver per-port state.
2439 * We have a proc file in /proc/tty/driver which is named after the
2442 * drv->port should be NULL, and the per-port structures should be
2443 * registered using uart_add_one_port after this call has succeeded.
2445 int uart_register_driver(struct uart_driver *drv)
2447 struct tty_driver *normal;
2453 * Maybe we should be using a slab cache for this, especially if
2454 * we have a large number of ports to handle.
2456 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2460 normal = alloc_tty_driver(drv->nr);
2464 drv->tty_driver = normal;
2466 normal->driver_name = drv->driver_name;
2467 normal->name = drv->dev_name;
2468 normal->major = drv->major;
2469 normal->minor_start = drv->minor;
2470 normal->type = TTY_DRIVER_TYPE_SERIAL;
2471 normal->subtype = SERIAL_TYPE_NORMAL;
2472 normal->init_termios = tty_std_termios;
2473 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2474 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2475 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2476 normal->driver_state = drv;
2477 tty_set_operations(normal, &uart_ops);
2480 * Initialise the UART state(s).
2482 for (i = 0; i < drv->nr; i++) {
2483 struct uart_state *state = drv->state + i;
2484 struct tty_port *port = &state->port;
2486 tty_port_init(port);
2487 port->ops = &uart_port_ops;
2490 retval = tty_register_driver(normal);
2494 for (i = 0; i < drv->nr; i++)
2495 tty_port_destroy(&drv->state[i].port);
2496 put_tty_driver(normal);
2504 * uart_unregister_driver - remove a driver from the uart core layer
2505 * @drv: low level driver structure
2507 * Remove all references to a driver from the core driver. The low
2508 * level driver must have removed all its ports via the
2509 * uart_remove_one_port() if it registered them with uart_add_one_port().
2510 * (ie, drv->port == NULL)
2512 void uart_unregister_driver(struct uart_driver *drv)
2514 struct tty_driver *p = drv->tty_driver;
2517 tty_unregister_driver(p);
2519 for (i = 0; i < drv->nr; i++)
2520 tty_port_destroy(&drv->state[i].port);
2523 drv->tty_driver = NULL;
2526 struct tty_driver *uart_console_device(struct console *co, int *index)
2528 struct uart_driver *p = co->data;
2530 return p->tty_driver;
2533 static ssize_t uart_get_attr_uartclk(struct device *dev,
2534 struct device_attribute *attr, char *buf)
2536 struct serial_struct tmp;
2537 struct tty_port *port = dev_get_drvdata(dev);
2539 uart_get_info(port, &tmp);
2540 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2543 static ssize_t uart_get_attr_type(struct device *dev,
2544 struct device_attribute *attr, char *buf)
2546 struct serial_struct tmp;
2547 struct tty_port *port = dev_get_drvdata(dev);
2549 uart_get_info(port, &tmp);
2550 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2552 static ssize_t uart_get_attr_line(struct device *dev,
2553 struct device_attribute *attr, char *buf)
2555 struct serial_struct tmp;
2556 struct tty_port *port = dev_get_drvdata(dev);
2558 uart_get_info(port, &tmp);
2559 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2562 static ssize_t uart_get_attr_port(struct device *dev,
2563 struct device_attribute *attr, char *buf)
2565 struct serial_struct tmp;
2566 struct tty_port *port = dev_get_drvdata(dev);
2567 unsigned long ioaddr;
2569 uart_get_info(port, &tmp);
2571 if (HIGH_BITS_OFFSET)
2572 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2573 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2576 static ssize_t uart_get_attr_irq(struct device *dev,
2577 struct device_attribute *attr, char *buf)
2579 struct serial_struct tmp;
2580 struct tty_port *port = dev_get_drvdata(dev);
2582 uart_get_info(port, &tmp);
2583 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2586 static ssize_t uart_get_attr_flags(struct device *dev,
2587 struct device_attribute *attr, char *buf)
2589 struct serial_struct tmp;
2590 struct tty_port *port = dev_get_drvdata(dev);
2592 uart_get_info(port, &tmp);
2593 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2596 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2597 struct device_attribute *attr, char *buf)
2599 struct serial_struct tmp;
2600 struct tty_port *port = dev_get_drvdata(dev);
2602 uart_get_info(port, &tmp);
2603 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2607 static ssize_t uart_get_attr_close_delay(struct device *dev,
2608 struct device_attribute *attr, char *buf)
2610 struct serial_struct tmp;
2611 struct tty_port *port = dev_get_drvdata(dev);
2613 uart_get_info(port, &tmp);
2614 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2618 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2619 struct device_attribute *attr, char *buf)
2621 struct serial_struct tmp;
2622 struct tty_port *port = dev_get_drvdata(dev);
2624 uart_get_info(port, &tmp);
2625 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2628 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2629 struct device_attribute *attr, char *buf)
2631 struct serial_struct tmp;
2632 struct tty_port *port = dev_get_drvdata(dev);
2634 uart_get_info(port, &tmp);
2635 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2638 static ssize_t uart_get_attr_io_type(struct device *dev,
2639 struct device_attribute *attr, char *buf)
2641 struct serial_struct tmp;
2642 struct tty_port *port = dev_get_drvdata(dev);
2644 uart_get_info(port, &tmp);
2645 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2648 static ssize_t uart_get_attr_iomem_base(struct device *dev,
2649 struct device_attribute *attr, char *buf)
2651 struct serial_struct tmp;
2652 struct tty_port *port = dev_get_drvdata(dev);
2654 uart_get_info(port, &tmp);
2655 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2658 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2659 struct device_attribute *attr, char *buf)
2661 struct serial_struct tmp;
2662 struct tty_port *port = dev_get_drvdata(dev);
2664 uart_get_info(port, &tmp);
2665 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2668 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2669 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2670 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2671 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2672 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2673 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2674 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2675 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2676 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2677 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2678 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2679 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2680 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2682 static struct attribute *tty_dev_attrs[] = {
2683 &dev_attr_type.attr,
2684 &dev_attr_line.attr,
2685 &dev_attr_port.attr,
2687 &dev_attr_flags.attr,
2688 &dev_attr_xmit_fifo_size.attr,
2689 &dev_attr_uartclk.attr,
2690 &dev_attr_close_delay.attr,
2691 &dev_attr_closing_wait.attr,
2692 &dev_attr_custom_divisor.attr,
2693 &dev_attr_io_type.attr,
2694 &dev_attr_iomem_base.attr,
2695 &dev_attr_iomem_reg_shift.attr,
2699 static const struct attribute_group tty_dev_attr_group = {
2700 .attrs = tty_dev_attrs,
2704 * uart_add_one_port - attach a driver-defined port structure
2705 * @drv: pointer to the uart low level driver structure for this port
2706 * @uport: uart port structure to use for this port.
2708 * This allows the driver to register its own uart_port structure
2709 * with the core driver. The main purpose is to allow the low
2710 * level uart drivers to expand uart_port, rather than having yet
2711 * more levels of structures.
2713 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2715 struct uart_state *state;
2716 struct tty_port *port;
2718 struct device *tty_dev;
2721 BUG_ON(in_interrupt());
2723 if (uport->line >= drv->nr)
2726 state = drv->state + uport->line;
2727 port = &state->port;
2729 mutex_lock(&port_mutex);
2730 mutex_lock(&port->mutex);
2731 if (state->uart_port) {
2736 /* Link the port to the driver state table and vice versa */
2737 atomic_set(&state->refcount, 1);
2738 init_waitqueue_head(&state->remove_wait);
2739 state->uart_port = uport;
2740 uport->state = state;
2742 state->pm_state = UART_PM_STATE_UNDEFINED;
2743 uport->cons = drv->cons;
2744 uport->minor = drv->tty_driver->minor_start + uport->line;
2745 uport->name = kasprintf(GFP_KERNEL, "%s%d", drv->dev_name,
2746 drv->tty_driver->name_base + uport->line);
2753 * If this port is a console, then the spinlock is already
2756 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2757 spin_lock_init(&uport->lock);
2758 lockdep_set_class(&uport->lock, &port_lock_key);
2760 if (uport->cons && uport->dev)
2761 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2763 uart_configure_port(drv, state, uport);
2765 port->console = uart_console(uport);
2768 if (uport->attr_group)
2771 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2773 if (!uport->tty_groups) {
2777 uport->tty_groups[0] = &tty_dev_attr_group;
2778 if (uport->attr_group)
2779 uport->tty_groups[1] = uport->attr_group;
2782 * Register the port whether it's detected or not. This allows
2783 * setserial to be used to alter this port's parameters.
2785 tty_dev = tty_port_register_device_attr_serdev(port, drv->tty_driver,
2786 uport->line, uport->dev, port, uport->tty_groups);
2787 if (likely(!IS_ERR(tty_dev))) {
2788 device_set_wakeup_capable(tty_dev, 1);
2790 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2795 * Ensure UPF_DEAD is not set.
2797 uport->flags &= ~UPF_DEAD;
2800 mutex_unlock(&port->mutex);
2801 mutex_unlock(&port_mutex);
2807 * uart_remove_one_port - detach a driver defined port structure
2808 * @drv: pointer to the uart low level driver structure for this port
2809 * @uport: uart port structure for this port
2811 * This unhooks (and hangs up) the specified port structure from the
2812 * core driver. No further calls will be made to the low-level code
2815 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2817 struct uart_state *state = drv->state + uport->line;
2818 struct tty_port *port = &state->port;
2819 struct uart_port *uart_port;
2820 struct tty_struct *tty;
2823 BUG_ON(in_interrupt());
2825 mutex_lock(&port_mutex);
2828 * Mark the port "dead" - this prevents any opens from
2829 * succeeding while we shut down the port.
2831 mutex_lock(&port->mutex);
2832 uart_port = uart_port_check(state);
2833 if (uart_port != uport)
2834 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2838 mutex_unlock(&port->mutex);
2842 uport->flags |= UPF_DEAD;
2843 mutex_unlock(&port->mutex);
2846 * Remove the devices from the tty layer
2848 tty_port_unregister_device(port, drv->tty_driver, uport->line);
2850 tty = tty_port_tty_get(port);
2852 tty_vhangup(port->tty);
2857 * If the port is used as a console, unregister it
2859 if (uart_console(uport))
2860 unregister_console(uport->cons);
2863 * Free the port IO and memory resources, if any.
2865 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
2866 uport->ops->release_port(uport);
2867 kfree(uport->tty_groups);
2871 * Indicate that there isn't a port here anymore.
2873 uport->type = PORT_UNKNOWN;
2875 mutex_lock(&port->mutex);
2876 WARN_ON(atomic_dec_return(&state->refcount) < 0);
2877 wait_event(state->remove_wait, !atomic_read(&state->refcount));
2878 state->uart_port = NULL;
2879 mutex_unlock(&port->mutex);
2881 mutex_unlock(&port_mutex);
2887 * Are the two ports equivalent?
2889 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2891 if (port1->iotype != port2->iotype)
2894 switch (port1->iotype) {
2896 return (port1->iobase == port2->iobase);
2898 return (port1->iobase == port2->iobase) &&
2899 (port1->hub6 == port2->hub6);
2906 return (port1->mapbase == port2->mapbase);
2910 EXPORT_SYMBOL(uart_match_port);
2913 * uart_handle_dcd_change - handle a change of carrier detect state
2914 * @uport: uart_port structure for the open port
2915 * @status: new carrier detect status, nonzero if active
2917 * Caller must hold uport->lock
2919 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2921 struct tty_port *port = &uport->state->port;
2922 struct tty_struct *tty = port->tty;
2923 struct tty_ldisc *ld;
2925 lockdep_assert_held_once(&uport->lock);
2928 ld = tty_ldisc_ref(tty);
2930 if (ld->ops->dcd_change)
2931 ld->ops->dcd_change(tty, status);
2932 tty_ldisc_deref(ld);
2936 uport->icount.dcd++;
2938 if (uart_dcd_enabled(uport)) {
2940 wake_up_interruptible(&port->open_wait);
2945 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2948 * uart_handle_cts_change - handle a change of clear-to-send state
2949 * @uport: uart_port structure for the open port
2950 * @status: new clear to send status, nonzero if active
2952 * Caller must hold uport->lock
2954 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2956 lockdep_assert_held_once(&uport->lock);
2958 uport->icount.cts++;
2960 if (uart_softcts_mode(uport)) {
2961 if (uport->hw_stopped) {
2963 uport->hw_stopped = 0;
2964 uport->ops->start_tx(uport);
2965 uart_write_wakeup(uport);
2969 uport->hw_stopped = 1;
2970 uport->ops->stop_tx(uport);
2976 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2979 * uart_insert_char - push a char to the uart layer
2981 * User is responsible to call tty_flip_buffer_push when they are done with
2984 * @port: corresponding port
2985 * @status: state of the serial port RX buffer (LSR for 8250)
2986 * @overrun: mask of overrun bits in @status
2987 * @ch: character to push
2988 * @flag: flag for the character (see TTY_NORMAL and friends)
2990 void uart_insert_char(struct uart_port *port, unsigned int status,
2991 unsigned int overrun, unsigned int ch, unsigned int flag)
2993 struct tty_port *tport = &port->state->port;
2995 if ((status & port->ignore_status_mask & ~overrun) == 0)
2996 if (tty_insert_flip_char(tport, ch, flag) == 0)
2997 ++port->icount.buf_overrun;
3000 * Overrun is special. Since it's reported immediately,
3001 * it doesn't affect the current character.
3003 if (status & ~port->ignore_status_mask & overrun)
3004 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
3005 ++port->icount.buf_overrun;
3007 EXPORT_SYMBOL_GPL(uart_insert_char);
3009 EXPORT_SYMBOL(uart_write_wakeup);
3010 EXPORT_SYMBOL(uart_register_driver);
3011 EXPORT_SYMBOL(uart_unregister_driver);
3012 EXPORT_SYMBOL(uart_suspend_port);
3013 EXPORT_SYMBOL(uart_resume_port);
3014 EXPORT_SYMBOL(uart_add_one_port);
3015 EXPORT_SYMBOL(uart_remove_one_port);
3017 MODULE_DESCRIPTION("Serial driver core");
3018 MODULE_LICENSE("GPL");