2 * linux/drivers/char/core.c
4 * Driver core for serial ports
6 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
8 * Copyright 1999 ARM Limited
9 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 #include <linux/module.h>
26 #include <linux/tty.h>
27 #include <linux/slab.h>
28 #include <linux/init.h>
29 #include <linux/console.h>
30 #include <linux/serial_core.h>
31 #include <linux/smp_lock.h>
32 #include <linux/device.h>
33 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
34 #include <linux/delay.h>
35 #include <linux/mutex.h>
38 #include <asm/uaccess.h>
41 * This is used to lock changes in serial line configuration.
43 static DEFINE_MUTEX(port_mutex);
46 * lockdep: port->lock is initialized in two places, but we
47 * want only one lock-class:
49 static struct lock_class_key port_lock_key;
51 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
53 #define uart_users(state) ((state)->count + ((state)->info ? (state)->info->blocked_open : 0))
55 #ifdef CONFIG_SERIAL_CORE_CONSOLE
56 #define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
58 #define uart_console(port) (0)
61 static void uart_change_speed(struct uart_state *state,
62 struct ktermios *old_termios);
63 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
64 static void uart_change_pm(struct uart_state *state, int pm_state);
67 * This routine is used by the interrupt handler to schedule processing in
68 * the software interrupt portion of the driver.
70 void uart_write_wakeup(struct uart_port *port)
72 struct uart_info *info = port->info;
74 * This means you called this function _after_ the port was
75 * closed. No cookie for you.
78 tasklet_schedule(&info->tlet);
81 static void uart_stop(struct tty_struct *tty)
83 struct uart_state *state = tty->driver_data;
84 struct uart_port *port = state->port;
87 spin_lock_irqsave(&port->lock, flags);
88 port->ops->stop_tx(port);
89 spin_unlock_irqrestore(&port->lock, flags);
92 static void __uart_start(struct tty_struct *tty)
94 struct uart_state *state = tty->driver_data;
95 struct uart_port *port = state->port;
97 if (!uart_circ_empty(&state->info->xmit) && state->info->xmit.buf &&
98 !tty->stopped && !tty->hw_stopped)
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->port;
108 spin_lock_irqsave(&port->lock, flags);
110 spin_unlock_irqrestore(&port->lock, flags);
113 static void uart_tasklet_action(unsigned long data)
115 struct uart_state *state = (struct uart_state *)data;
116 tty_wakeup(state->info->tty);
120 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
125 spin_lock_irqsave(&port->lock, flags);
127 port->mctrl = (old & ~clear) | set;
128 if (old != port->mctrl)
129 port->ops->set_mctrl(port, port->mctrl);
130 spin_unlock_irqrestore(&port->lock, flags);
133 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
134 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
137 * Startup the port. This will be called once per open. All calls
138 * will be serialised by the per-port semaphore.
140 static int uart_startup(struct uart_state *state, int init_hw)
142 struct uart_info *info = state->info;
143 struct uart_port *port = state->port;
147 if (info->flags & UIF_INITIALIZED)
151 * Set the TTY IO error marker - we will only clear this
152 * once we have successfully opened the port. Also set
153 * up the tty->alt_speed kludge
155 set_bit(TTY_IO_ERROR, &info->tty->flags);
157 if (port->type == PORT_UNKNOWN)
161 * Initialise and allocate the transmit and temporary
164 if (!info->xmit.buf) {
165 page = get_zeroed_page(GFP_KERNEL);
169 info->xmit.buf = (unsigned char *) page;
170 uart_circ_clear(&info->xmit);
173 retval = port->ops->startup(port);
177 * Initialise the hardware port settings.
179 uart_change_speed(state, NULL);
182 * Setup the RTS and DTR signals once the
183 * port is open and ready to respond.
185 if (info->tty->termios->c_cflag & CBAUD)
186 uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
189 if (info->flags & UIF_CTS_FLOW) {
190 spin_lock_irq(&port->lock);
191 if (!(port->ops->get_mctrl(port) & TIOCM_CTS))
192 info->tty->hw_stopped = 1;
193 spin_unlock_irq(&port->lock);
196 info->flags |= UIF_INITIALIZED;
198 clear_bit(TTY_IO_ERROR, &info->tty->flags);
201 if (retval && capable(CAP_SYS_ADMIN))
208 * This routine will shutdown a serial port; interrupts are disabled, and
209 * DTR is dropped if the hangup on close termio flag is on. Calls to
210 * uart_shutdown are serialised by the per-port semaphore.
212 static void uart_shutdown(struct uart_state *state)
214 struct uart_info *info = state->info;
215 struct uart_port *port = state->port;
218 * Set the TTY IO error marker
221 set_bit(TTY_IO_ERROR, &info->tty->flags);
223 if (info->flags & UIF_INITIALIZED) {
224 info->flags &= ~UIF_INITIALIZED;
227 * Turn off DTR and RTS early.
229 if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
230 uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
233 * clear delta_msr_wait queue to avoid mem leaks: we may free
234 * the irq here so the queue might never be woken up. Note
235 * that we won't end up waiting on delta_msr_wait again since
236 * any outstanding file descriptors should be pointing at
237 * hung_up_tty_fops now.
239 wake_up_interruptible(&info->delta_msr_wait);
242 * Free the IRQ and disable the port.
244 port->ops->shutdown(port);
247 * Ensure that the IRQ handler isn't running on another CPU.
249 synchronize_irq(port->irq);
253 * kill off our tasklet
255 tasklet_kill(&info->tlet);
258 * Free the transmit buffer page.
260 if (info->xmit.buf) {
261 free_page((unsigned long)info->xmit.buf);
262 info->xmit.buf = NULL;
267 * uart_update_timeout - update per-port FIFO timeout.
268 * @port: uart_port structure describing the port
269 * @cflag: termios cflag value
270 * @baud: speed of the port
272 * Set the port FIFO timeout value. The @cflag value should
273 * reflect the actual hardware settings.
276 uart_update_timeout(struct uart_port *port, unsigned int cflag,
281 /* byte size and parity */
282 switch (cflag & CSIZE) {
303 * The total number of bits to be transmitted in the fifo.
305 bits = bits * port->fifosize;
308 * Figure the timeout to send the above number of bits.
309 * Add .02 seconds of slop
311 port->timeout = (HZ * bits) / baud + HZ/50;
314 EXPORT_SYMBOL(uart_update_timeout);
317 * uart_get_baud_rate - return baud rate for a particular port
318 * @port: uart_port structure describing the port in question.
319 * @termios: desired termios settings.
320 * @old: old termios (or NULL)
321 * @min: minimum acceptable baud rate
322 * @max: maximum acceptable baud rate
324 * Decode the termios structure into a numeric baud rate,
325 * taking account of the magic 38400 baud rate (with spd_*
326 * flags), and mapping the %B0 rate to 9600 baud.
328 * If the new baud rate is invalid, try the old termios setting.
329 * If it's still invalid, we try 9600 baud.
331 * Update the @termios structure to reflect the baud rate
332 * we're actually going to be using. Don't do this for the case
333 * where B0 is requested ("hang up").
336 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
337 struct ktermios *old, unsigned int min, unsigned int max)
339 unsigned int try, baud, altbaud = 38400;
341 upf_t flags = port->flags & UPF_SPD_MASK;
343 if (flags == UPF_SPD_HI)
345 if (flags == UPF_SPD_VHI)
347 if (flags == UPF_SPD_SHI)
349 if (flags == UPF_SPD_WARP)
352 for (try = 0; try < 2; try++) {
353 baud = tty_termios_baud_rate(termios);
356 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
363 * Special case: B0 rate.
370 if (baud >= min && baud <= max)
374 * Oops, the quotient was zero. Try again with
375 * the old baud rate if possible.
377 termios->c_cflag &= ~CBAUD;
379 baud = tty_termios_baud_rate(old);
381 tty_termios_encode_baud_rate(termios,
388 * As a last resort, if the quotient is zero,
389 * default to 9600 bps
392 tty_termios_encode_baud_rate(termios, 9600, 9600);
398 EXPORT_SYMBOL(uart_get_baud_rate);
401 * uart_get_divisor - return uart clock divisor
402 * @port: uart_port structure describing the port.
403 * @baud: desired baud rate
405 * Calculate the uart clock divisor for the port.
408 uart_get_divisor(struct uart_port *port, unsigned int baud)
413 * Old custom speed handling.
415 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
416 quot = port->custom_divisor;
418 quot = (port->uartclk + (8 * baud)) / (16 * baud);
423 EXPORT_SYMBOL(uart_get_divisor);
426 uart_change_speed(struct uart_state *state, struct ktermios *old_termios)
428 struct tty_struct *tty = state->info->tty;
429 struct uart_port *port = state->port;
430 struct ktermios *termios;
433 * If we have no tty, termios, or the port does not exist,
434 * then we can't set the parameters for this port.
436 if (!tty || !tty->termios || port->type == PORT_UNKNOWN)
439 termios = tty->termios;
442 * Set flags based on termios cflag
444 if (termios->c_cflag & CRTSCTS)
445 state->info->flags |= UIF_CTS_FLOW;
447 state->info->flags &= ~UIF_CTS_FLOW;
449 if (termios->c_cflag & CLOCAL)
450 state->info->flags &= ~UIF_CHECK_CD;
452 state->info->flags |= UIF_CHECK_CD;
454 port->ops->set_termios(port, termios, old_termios);
458 __uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c)
465 spin_lock_irqsave(&port->lock, flags);
466 if (uart_circ_chars_free(circ) != 0) {
467 circ->buf[circ->head] = c;
468 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
470 spin_unlock_irqrestore(&port->lock, flags);
473 static void uart_put_char(struct tty_struct *tty, unsigned char ch)
475 struct uart_state *state = tty->driver_data;
477 __uart_put_char(state->port, &state->info->xmit, ch);
480 static void uart_flush_chars(struct tty_struct *tty)
486 uart_write(struct tty_struct *tty, const unsigned char *buf, int count)
488 struct uart_state *state = tty->driver_data;
489 struct uart_port *port;
490 struct circ_buf *circ;
495 * This means you called this function _after_ the port was
496 * closed. No cookie for you.
498 if (!state || !state->info) {
504 circ = &state->info->xmit;
509 spin_lock_irqsave(&port->lock, flags);
511 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
516 memcpy(circ->buf + circ->head, buf, c);
517 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
522 spin_unlock_irqrestore(&port->lock, flags);
528 static int uart_write_room(struct tty_struct *tty)
530 struct uart_state *state = tty->driver_data;
532 return uart_circ_chars_free(&state->info->xmit);
535 static int uart_chars_in_buffer(struct tty_struct *tty)
537 struct uart_state *state = tty->driver_data;
539 return uart_circ_chars_pending(&state->info->xmit);
542 static void uart_flush_buffer(struct tty_struct *tty)
544 struct uart_state *state = tty->driver_data;
545 struct uart_port *port = state->port;
549 * This means you called this function _after_ the port was
550 * closed. No cookie for you.
552 if (!state || !state->info) {
557 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
559 spin_lock_irqsave(&port->lock, flags);
560 uart_circ_clear(&state->info->xmit);
561 spin_unlock_irqrestore(&port->lock, flags);
566 * This function is used to send a high-priority XON/XOFF character to
569 static void uart_send_xchar(struct tty_struct *tty, char ch)
571 struct uart_state *state = tty->driver_data;
572 struct uart_port *port = state->port;
575 if (port->ops->send_xchar)
576 port->ops->send_xchar(port, ch);
580 spin_lock_irqsave(&port->lock, flags);
581 port->ops->start_tx(port);
582 spin_unlock_irqrestore(&port->lock, flags);
587 static void uart_throttle(struct tty_struct *tty)
589 struct uart_state *state = tty->driver_data;
592 uart_send_xchar(tty, STOP_CHAR(tty));
594 if (tty->termios->c_cflag & CRTSCTS)
595 uart_clear_mctrl(state->port, TIOCM_RTS);
598 static void uart_unthrottle(struct tty_struct *tty)
600 struct uart_state *state = tty->driver_data;
601 struct uart_port *port = state->port;
607 uart_send_xchar(tty, START_CHAR(tty));
610 if (tty->termios->c_cflag & CRTSCTS)
611 uart_set_mctrl(port, TIOCM_RTS);
614 static int uart_get_info(struct uart_state *state,
615 struct serial_struct __user *retinfo)
617 struct uart_port *port = state->port;
618 struct serial_struct tmp;
620 memset(&tmp, 0, sizeof(tmp));
621 tmp.type = port->type;
622 tmp.line = port->line;
623 tmp.port = port->iobase;
624 if (HIGH_BITS_OFFSET)
625 tmp.port_high = (long) port->iobase >> HIGH_BITS_OFFSET;
627 tmp.flags = port->flags;
628 tmp.xmit_fifo_size = port->fifosize;
629 tmp.baud_base = port->uartclk / 16;
630 tmp.close_delay = state->close_delay / 10;
631 tmp.closing_wait = state->closing_wait == USF_CLOSING_WAIT_NONE ?
632 ASYNC_CLOSING_WAIT_NONE :
633 state->closing_wait / 10;
634 tmp.custom_divisor = port->custom_divisor;
635 tmp.hub6 = port->hub6;
636 tmp.io_type = port->iotype;
637 tmp.iomem_reg_shift = port->regshift;
638 tmp.iomem_base = (void *)(unsigned long)port->mapbase;
640 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
645 static int uart_set_info(struct uart_state *state,
646 struct serial_struct __user *newinfo)
648 struct serial_struct new_serial;
649 struct uart_port *port = state->port;
650 unsigned long new_port;
651 unsigned int change_irq, change_port, closing_wait;
652 unsigned int old_custom_divisor, close_delay;
653 upf_t old_flags, new_flags;
656 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
659 new_port = new_serial.port;
660 if (HIGH_BITS_OFFSET)
661 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
663 new_serial.irq = irq_canonicalize(new_serial.irq);
664 close_delay = new_serial.close_delay * 10;
665 closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
666 USF_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
669 * This semaphore protects state->count. It is also
670 * very useful to prevent opens. Also, take the
671 * port configuration semaphore to make sure that a
672 * module insertion/removal doesn't change anything
675 mutex_lock(&state->mutex);
677 change_irq = !(port->flags & UPF_FIXED_PORT)
678 && new_serial.irq != port->irq;
681 * Since changing the 'type' of the port changes its resource
682 * allocations, we should treat type changes the same as
685 change_port = !(port->flags & UPF_FIXED_PORT)
686 && (new_port != port->iobase ||
687 (unsigned long)new_serial.iomem_base != port->mapbase ||
688 new_serial.hub6 != port->hub6 ||
689 new_serial.io_type != port->iotype ||
690 new_serial.iomem_reg_shift != port->regshift ||
691 new_serial.type != port->type);
693 old_flags = port->flags;
694 new_flags = new_serial.flags;
695 old_custom_divisor = port->custom_divisor;
697 if (!capable(CAP_SYS_ADMIN)) {
699 if (change_irq || change_port ||
700 (new_serial.baud_base != port->uartclk / 16) ||
701 (close_delay != state->close_delay) ||
702 (closing_wait != state->closing_wait) ||
703 (new_serial.xmit_fifo_size &&
704 new_serial.xmit_fifo_size != port->fifosize) ||
705 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
707 port->flags = ((port->flags & ~UPF_USR_MASK) |
708 (new_flags & UPF_USR_MASK));
709 port->custom_divisor = new_serial.custom_divisor;
714 * Ask the low level driver to verify the settings.
716 if (port->ops->verify_port)
717 retval = port->ops->verify_port(port, &new_serial);
719 if ((new_serial.irq >= NR_IRQS) || (new_serial.irq < 0) ||
720 (new_serial.baud_base < 9600))
726 if (change_port || change_irq) {
730 * Make sure that we are the sole user of this port.
732 if (uart_users(state) > 1)
736 * We need to shutdown the serial port at the old
737 * port/type/irq combination.
739 uart_shutdown(state);
743 unsigned long old_iobase, old_mapbase;
744 unsigned int old_type, old_iotype, old_hub6, old_shift;
746 old_iobase = port->iobase;
747 old_mapbase = port->mapbase;
748 old_type = port->type;
749 old_hub6 = port->hub6;
750 old_iotype = port->iotype;
751 old_shift = port->regshift;
754 * Free and release old regions
756 if (old_type != PORT_UNKNOWN)
757 port->ops->release_port(port);
759 port->iobase = new_port;
760 port->type = new_serial.type;
761 port->hub6 = new_serial.hub6;
762 port->iotype = new_serial.io_type;
763 port->regshift = new_serial.iomem_reg_shift;
764 port->mapbase = (unsigned long)new_serial.iomem_base;
767 * Claim and map the new regions
769 if (port->type != PORT_UNKNOWN) {
770 retval = port->ops->request_port(port);
772 /* Always success - Jean II */
777 * If we fail to request resources for the
778 * new port, try to restore the old settings.
780 if (retval && old_type != PORT_UNKNOWN) {
781 port->iobase = old_iobase;
782 port->type = old_type;
783 port->hub6 = old_hub6;
784 port->iotype = old_iotype;
785 port->regshift = old_shift;
786 port->mapbase = old_mapbase;
787 retval = port->ops->request_port(port);
789 * If we failed to restore the old settings,
793 port->type = PORT_UNKNOWN;
799 /* Added to return the correct error -Ram Gupta */
805 port->irq = new_serial.irq;
806 if (!(port->flags & UPF_FIXED_PORT))
807 port->uartclk = new_serial.baud_base * 16;
808 port->flags = (port->flags & ~UPF_CHANGE_MASK) |
809 (new_flags & UPF_CHANGE_MASK);
810 port->custom_divisor = new_serial.custom_divisor;
811 state->close_delay = close_delay;
812 state->closing_wait = closing_wait;
813 if (new_serial.xmit_fifo_size)
814 port->fifosize = new_serial.xmit_fifo_size;
815 if (state->info->tty)
816 state->info->tty->low_latency =
817 (port->flags & UPF_LOW_LATENCY) ? 1 : 0;
821 if (port->type == PORT_UNKNOWN)
823 if (state->info->flags & UIF_INITIALIZED) {
824 if (((old_flags ^ port->flags) & UPF_SPD_MASK) ||
825 old_custom_divisor != port->custom_divisor) {
827 * If they're setting up a custom divisor or speed,
828 * instead of clearing it, then bitch about it. No
829 * need to rate-limit; it's CAP_SYS_ADMIN only.
831 if (port->flags & UPF_SPD_MASK) {
834 "%s sets custom speed on %s. This "
835 "is deprecated.\n", current->comm,
836 tty_name(state->info->tty, buf));
838 uart_change_speed(state, NULL);
841 retval = uart_startup(state, 1);
843 mutex_unlock(&state->mutex);
849 * uart_get_lsr_info - get line status register info.
850 * Note: uart_ioctl protects us against hangups.
852 static int uart_get_lsr_info(struct uart_state *state,
853 unsigned int __user *value)
855 struct uart_port *port = state->port;
858 result = port->ops->tx_empty(port);
861 * If we're about to load something into the transmit
862 * register, we'll pretend the transmitter isn't empty to
863 * avoid a race condition (depending on when the transmit
864 * interrupt happens).
867 ((uart_circ_chars_pending(&state->info->xmit) > 0) &&
868 !state->info->tty->stopped && !state->info->tty->hw_stopped))
869 result &= ~TIOCSER_TEMT;
871 return put_user(result, value);
874 static int uart_tiocmget(struct tty_struct *tty, struct file *file)
876 struct uart_state *state = tty->driver_data;
877 struct uart_port *port = state->port;
880 mutex_lock(&state->mutex);
881 if ((!file || !tty_hung_up_p(file)) &&
882 !(tty->flags & (1 << TTY_IO_ERROR))) {
883 result = port->mctrl;
885 spin_lock_irq(&port->lock);
886 result |= port->ops->get_mctrl(port);
887 spin_unlock_irq(&port->lock);
889 mutex_unlock(&state->mutex);
895 uart_tiocmset(struct tty_struct *tty, struct file *file,
896 unsigned int set, unsigned int clear)
898 struct uart_state *state = tty->driver_data;
899 struct uart_port *port = state->port;
902 mutex_lock(&state->mutex);
903 if ((!file || !tty_hung_up_p(file)) &&
904 !(tty->flags & (1 << TTY_IO_ERROR))) {
905 uart_update_mctrl(port, set, clear);
908 mutex_unlock(&state->mutex);
912 static void uart_break_ctl(struct tty_struct *tty, int break_state)
914 struct uart_state *state = tty->driver_data;
915 struct uart_port *port = state->port;
918 mutex_lock(&state->mutex);
920 if (port->type != PORT_UNKNOWN)
921 port->ops->break_ctl(port, break_state);
923 mutex_unlock(&state->mutex);
927 static int uart_do_autoconfig(struct uart_state *state)
929 struct uart_port *port = state->port;
932 if (!capable(CAP_SYS_ADMIN))
936 * Take the per-port semaphore. This prevents count from
937 * changing, and hence any extra opens of the port while
938 * we're auto-configuring.
940 if (mutex_lock_interruptible(&state->mutex))
944 if (uart_users(state) == 1) {
945 uart_shutdown(state);
948 * If we already have a port type configured,
949 * we must release its resources.
951 if (port->type != PORT_UNKNOWN)
952 port->ops->release_port(port);
954 flags = UART_CONFIG_TYPE;
955 if (port->flags & UPF_AUTO_IRQ)
956 flags |= UART_CONFIG_IRQ;
959 * This will claim the ports resources if
962 port->ops->config_port(port, flags);
964 ret = uart_startup(state, 1);
966 mutex_unlock(&state->mutex);
971 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
972 * - mask passed in arg for lines of interest
973 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
974 * Caller should use TIOCGICOUNT to see which one it was
977 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
979 struct uart_port *port = state->port;
980 DECLARE_WAITQUEUE(wait, current);
981 struct uart_icount cprev, cnow;
985 * note the counters on entry
987 spin_lock_irq(&port->lock);
988 memcpy(&cprev, &port->icount, sizeof(struct uart_icount));
991 * Force modem status interrupts on
993 port->ops->enable_ms(port);
994 spin_unlock_irq(&port->lock);
996 add_wait_queue(&state->info->delta_msr_wait, &wait);
998 spin_lock_irq(&port->lock);
999 memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
1000 spin_unlock_irq(&port->lock);
1002 set_current_state(TASK_INTERRUPTIBLE);
1004 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1005 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1006 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1007 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1014 /* see if a signal did it */
1015 if (signal_pending(current)) {
1023 current->state = TASK_RUNNING;
1024 remove_wait_queue(&state->info->delta_msr_wait, &wait);
1030 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1031 * Return: write counters to the user passed counter struct
1032 * NB: both 1->0 and 0->1 transitions are counted except for
1033 * RI where only 0->1 is counted.
1035 static int uart_get_count(struct uart_state *state,
1036 struct serial_icounter_struct __user *icnt)
1038 struct serial_icounter_struct icount;
1039 struct uart_icount cnow;
1040 struct uart_port *port = state->port;
1042 spin_lock_irq(&port->lock);
1043 memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
1044 spin_unlock_irq(&port->lock);
1046 icount.cts = cnow.cts;
1047 icount.dsr = cnow.dsr;
1048 icount.rng = cnow.rng;
1049 icount.dcd = cnow.dcd;
1050 icount.rx = cnow.rx;
1051 icount.tx = cnow.tx;
1052 icount.frame = cnow.frame;
1053 icount.overrun = cnow.overrun;
1054 icount.parity = cnow.parity;
1055 icount.brk = cnow.brk;
1056 icount.buf_overrun = cnow.buf_overrun;
1058 return copy_to_user(icnt, &icount, sizeof(icount)) ? -EFAULT : 0;
1062 * Called via sys_ioctl. We can use spin_lock_irq() here.
1065 uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
1068 struct uart_state *state = tty->driver_data;
1069 void __user *uarg = (void __user *)arg;
1070 int ret = -ENOIOCTLCMD;
1075 * These ioctls don't rely on the hardware to be present.
1079 ret = uart_get_info(state, uarg);
1083 ret = uart_set_info(state, uarg);
1087 ret = uart_do_autoconfig(state);
1090 case TIOCSERGWILD: /* obsolete */
1091 case TIOCSERSWILD: /* obsolete */
1096 if (ret != -ENOIOCTLCMD)
1099 if (tty->flags & (1 << TTY_IO_ERROR)) {
1105 * The following should only be used when hardware is present.
1109 ret = uart_wait_modem_status(state, arg);
1113 ret = uart_get_count(state, uarg);
1117 if (ret != -ENOIOCTLCMD)
1120 mutex_lock(&state->mutex);
1122 if (tty_hung_up_p(filp)) {
1128 * All these rely on hardware being present and need to be
1129 * protected against the tty being hung up.
1132 case TIOCSERGETLSR: /* Get line status register */
1133 ret = uart_get_lsr_info(state, uarg);
1137 struct uart_port *port = state->port;
1138 if (port->ops->ioctl)
1139 ret = port->ops->ioctl(port, cmd, arg);
1144 mutex_unlock(&state->mutex);
1150 static void uart_set_termios(struct tty_struct *tty,
1151 struct ktermios *old_termios)
1153 struct uart_state *state = tty->driver_data;
1154 unsigned long flags;
1155 unsigned int cflag = tty->termios->c_cflag;
1159 * These are the bits that are used to setup various
1160 * flags in the low level driver. We can ignore the Bfoo
1161 * bits in c_cflag; c_[io]speed will always be set
1162 * appropriately by set_termios() in tty_ioctl.c
1164 #define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1165 if ((cflag ^ old_termios->c_cflag) == 0 &&
1166 tty->termios->c_ospeed == old_termios->c_ospeed &&
1167 tty->termios->c_ispeed == old_termios->c_ispeed &&
1168 RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) {
1173 uart_change_speed(state, old_termios);
1175 /* Handle transition to B0 status */
1176 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1177 uart_clear_mctrl(state->port, TIOCM_RTS | TIOCM_DTR);
1179 /* Handle transition away from B0 status */
1180 if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1181 unsigned int mask = TIOCM_DTR;
1182 if (!(cflag & CRTSCTS) ||
1183 !test_bit(TTY_THROTTLED, &tty->flags))
1185 uart_set_mctrl(state->port, mask);
1188 /* Handle turning off CRTSCTS */
1189 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1190 spin_lock_irqsave(&state->port->lock, flags);
1191 tty->hw_stopped = 0;
1193 spin_unlock_irqrestore(&state->port->lock, flags);
1196 /* Handle turning on CRTSCTS */
1197 if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1198 spin_lock_irqsave(&state->port->lock, flags);
1199 if (!(state->port->ops->get_mctrl(state->port) & TIOCM_CTS)) {
1200 tty->hw_stopped = 1;
1201 state->port->ops->stop_tx(state->port);
1203 spin_unlock_irqrestore(&state->port->lock, flags);
1208 * No need to wake up processes in open wait, since they
1209 * sample the CLOCAL flag once, and don't recheck it.
1210 * XXX It's not clear whether the current behavior is correct
1211 * or not. Hence, this may change.....
1213 if (!(old_termios->c_cflag & CLOCAL) &&
1214 (tty->termios->c_cflag & CLOCAL))
1215 wake_up_interruptible(&state->info->open_wait);
1220 * In 2.4.5, calls to this will be serialized via the BKL in
1221 * linux/drivers/char/tty_io.c:tty_release()
1222 * linux/drivers/char/tty_io.c:do_tty_handup()
1224 static void uart_close(struct tty_struct *tty, struct file *filp)
1226 struct uart_state *state = tty->driver_data;
1227 struct uart_port *port;
1229 BUG_ON(!kernel_locked());
1231 if (!state || !state->port)
1236 pr_debug("uart_close(%d) called\n", port->line);
1238 mutex_lock(&state->mutex);
1240 if (tty_hung_up_p(filp))
1243 if ((tty->count == 1) && (state->count != 1)) {
1245 * Uh, oh. tty->count is 1, which means that the tty
1246 * structure will be freed. state->count should always
1247 * be one in these conditions. If it's greater than
1248 * one, we've got real problems, since it means the
1249 * serial port won't be shutdown.
1251 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1252 "state->count is %d\n", state->count);
1255 if (--state->count < 0) {
1256 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1257 tty->name, state->count);
1264 * Now we wait for the transmit buffer to clear; and we notify
1265 * the line discipline to only process XON/XOFF characters by
1266 * setting tty->closing.
1270 if (state->closing_wait != USF_CLOSING_WAIT_NONE)
1271 tty_wait_until_sent(tty, msecs_to_jiffies(state->closing_wait));
1274 * At this point, we stop accepting input. To do this, we
1275 * disable the receive line status interrupts.
1277 if (state->info->flags & UIF_INITIALIZED) {
1278 unsigned long flags;
1279 spin_lock_irqsave(&port->lock, flags);
1280 port->ops->stop_rx(port);
1281 spin_unlock_irqrestore(&port->lock, flags);
1283 * Before we drop DTR, make sure the UART transmitter
1284 * has completely drained; this is especially
1285 * important if there is a transmit FIFO!
1287 uart_wait_until_sent(tty, port->timeout);
1290 uart_shutdown(state);
1291 uart_flush_buffer(tty);
1293 tty_ldisc_flush(tty);
1296 state->info->tty = NULL;
1298 if (state->info->blocked_open) {
1299 if (state->close_delay)
1300 msleep_interruptible(state->close_delay);
1301 } else if (!uart_console(port)) {
1302 uart_change_pm(state, 3);
1306 * Wake up anyone trying to open this port.
1308 state->info->flags &= ~UIF_NORMAL_ACTIVE;
1309 wake_up_interruptible(&state->info->open_wait);
1312 mutex_unlock(&state->mutex);
1315 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1317 struct uart_state *state = tty->driver_data;
1318 struct uart_port *port = state->port;
1319 unsigned long char_time, expire;
1321 BUG_ON(!kernel_locked());
1323 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1327 * Set the check interval to be 1/5 of the estimated time to
1328 * send a single character, and make it at least 1. The check
1329 * interval should also be less than the timeout.
1331 * Note: we have to use pretty tight timings here to satisfy
1334 char_time = (port->timeout - HZ/50) / port->fifosize;
1335 char_time = char_time / 5;
1338 if (timeout && timeout < char_time)
1339 char_time = timeout;
1342 * If the transmitter hasn't cleared in twice the approximate
1343 * amount of time to send the entire FIFO, it probably won't
1344 * ever clear. This assumes the UART isn't doing flow
1345 * control, which is currently the case. Hence, if it ever
1346 * takes longer than port->timeout, this is probably due to a
1347 * UART bug of some kind. So, we clamp the timeout parameter at
1350 if (timeout == 0 || timeout > 2 * port->timeout)
1351 timeout = 2 * port->timeout;
1353 expire = jiffies + timeout;
1355 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1356 port->line, jiffies, expire);
1359 * Check whether the transmitter is empty every 'char_time'.
1360 * 'timeout' / 'expire' give us the maximum amount of time
1363 while (!port->ops->tx_empty(port)) {
1364 msleep_interruptible(jiffies_to_msecs(char_time));
1365 if (signal_pending(current))
1367 if (time_after(jiffies, expire))
1370 set_current_state(TASK_RUNNING); /* might not be needed */
1374 * This is called with the BKL held in
1375 * linux/drivers/char/tty_io.c:do_tty_hangup()
1376 * We're called from the eventd thread, so we can sleep for
1377 * a _short_ time only.
1379 static void uart_hangup(struct tty_struct *tty)
1381 struct uart_state *state = tty->driver_data;
1383 BUG_ON(!kernel_locked());
1384 pr_debug("uart_hangup(%d)\n", state->port->line);
1386 mutex_lock(&state->mutex);
1387 if (state->info && state->info->flags & UIF_NORMAL_ACTIVE) {
1388 uart_flush_buffer(tty);
1389 uart_shutdown(state);
1391 state->info->flags &= ~UIF_NORMAL_ACTIVE;
1392 state->info->tty = NULL;
1393 wake_up_interruptible(&state->info->open_wait);
1394 wake_up_interruptible(&state->info->delta_msr_wait);
1396 mutex_unlock(&state->mutex);
1400 * Copy across the serial console cflag setting into the termios settings
1401 * for the initial open of the port. This allows continuity between the
1402 * kernel settings, and the settings init adopts when it opens the port
1403 * for the first time.
1405 static void uart_update_termios(struct uart_state *state)
1407 struct tty_struct *tty = state->info->tty;
1408 struct uart_port *port = state->port;
1410 if (uart_console(port) && port->cons->cflag) {
1411 tty->termios->c_cflag = port->cons->cflag;
1412 port->cons->cflag = 0;
1416 * If the device failed to grab its irq resources,
1417 * or some other error occurred, don't try to talk
1418 * to the port hardware.
1420 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
1422 * Make termios settings take effect.
1424 uart_change_speed(state, NULL);
1427 * And finally enable the RTS and DTR signals.
1429 if (tty->termios->c_cflag & CBAUD)
1430 uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
1435 * Block the open until the port is ready. We must be called with
1436 * the per-port semaphore held.
1439 uart_block_til_ready(struct file *filp, struct uart_state *state)
1441 DECLARE_WAITQUEUE(wait, current);
1442 struct uart_info *info = state->info;
1443 struct uart_port *port = state->port;
1446 info->blocked_open++;
1449 add_wait_queue(&info->open_wait, &wait);
1451 set_current_state(TASK_INTERRUPTIBLE);
1454 * If we have been hung up, tell userspace/restart open.
1456 if (tty_hung_up_p(filp) || info->tty == NULL)
1460 * If the port has been closed, tell userspace/restart open.
1462 if (!(info->flags & UIF_INITIALIZED))
1466 * If non-blocking mode is set, or CLOCAL mode is set,
1467 * we don't want to wait for the modem status lines to
1468 * indicate that the port is ready.
1470 * Also, if the port is not enabled/configured, we want
1471 * to allow the open to succeed here. Note that we will
1472 * have set TTY_IO_ERROR for a non-existant port.
1474 if ((filp->f_flags & O_NONBLOCK) ||
1475 (info->tty->termios->c_cflag & CLOCAL) ||
1476 (info->tty->flags & (1 << TTY_IO_ERROR)))
1480 * Set DTR to allow modem to know we're waiting. Do
1481 * not set RTS here - we want to make sure we catch
1482 * the data from the modem.
1484 if (info->tty->termios->c_cflag & CBAUD)
1485 uart_set_mctrl(port, TIOCM_DTR);
1488 * and wait for the carrier to indicate that the
1489 * modem is ready for us.
1491 spin_lock_irq(&port->lock);
1492 port->ops->enable_ms(port);
1493 mctrl = port->ops->get_mctrl(port);
1494 spin_unlock_irq(&port->lock);
1495 if (mctrl & TIOCM_CAR)
1498 mutex_unlock(&state->mutex);
1500 mutex_lock(&state->mutex);
1502 if (signal_pending(current))
1505 set_current_state(TASK_RUNNING);
1506 remove_wait_queue(&info->open_wait, &wait);
1509 info->blocked_open--;
1511 if (signal_pending(current))
1512 return -ERESTARTSYS;
1514 if (!info->tty || tty_hung_up_p(filp))
1520 static struct uart_state *uart_get(struct uart_driver *drv, int line)
1522 struct uart_state *state;
1525 state = drv->state + line;
1526 if (mutex_lock_interruptible(&state->mutex)) {
1532 if (!state->port || state->port->flags & UPF_DEAD) {
1538 state->info = kzalloc(sizeof(struct uart_info), GFP_KERNEL);
1540 init_waitqueue_head(&state->info->open_wait);
1541 init_waitqueue_head(&state->info->delta_msr_wait);
1544 * Link the info into the other structures.
1546 state->port->info = state->info;
1548 tasklet_init(&state->info->tlet, uart_tasklet_action,
1549 (unsigned long)state);
1559 mutex_unlock(&state->mutex);
1561 return ERR_PTR(ret);
1565 * calls to uart_open are serialised by the BKL in
1566 * fs/char_dev.c:chrdev_open()
1567 * Note that if this fails, then uart_close() _will_ be called.
1569 * In time, we want to scrap the "opening nonpresent ports"
1570 * behaviour and implement an alternative way for setserial
1571 * to set base addresses/ports/types. This will allow us to
1572 * get rid of a certain amount of extra tests.
1574 static int uart_open(struct tty_struct *tty, struct file *filp)
1576 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1577 struct uart_state *state;
1578 int retval, line = tty->index;
1580 BUG_ON(!kernel_locked());
1581 pr_debug("uart_open(%d) called\n", line);
1584 * tty->driver->num won't change, so we won't fail here with
1585 * tty->driver_data set to something non-NULL (and therefore
1586 * we won't get caught by uart_close()).
1589 if (line >= tty->driver->num)
1593 * We take the semaphore inside uart_get to guarantee that we won't
1594 * be re-entered while allocating the info structure, or while we
1595 * request any IRQs that the driver may need. This also has the nice
1596 * side-effect that it delays the action of uart_hangup, so we can
1597 * guarantee that info->tty will always contain something reasonable.
1599 state = uart_get(drv, line);
1600 if (IS_ERR(state)) {
1601 retval = PTR_ERR(state);
1606 * Once we set tty->driver_data here, we are guaranteed that
1607 * uart_close() will decrement the driver module use count.
1608 * Any failures from here onwards should not touch the count.
1610 tty->driver_data = state;
1611 tty->low_latency = (state->port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1613 state->info->tty = tty;
1616 * If the port is in the middle of closing, bail out now.
1618 if (tty_hung_up_p(filp)) {
1621 mutex_unlock(&state->mutex);
1626 * Make sure the device is in D0 state.
1628 if (state->count == 1)
1629 uart_change_pm(state, 0);
1632 * Start up the serial port.
1634 retval = uart_startup(state, 0);
1637 * If we succeeded, wait until the port is ready.
1640 retval = uart_block_til_ready(filp, state);
1641 mutex_unlock(&state->mutex);
1644 * If this is the first open to succeed, adjust things to suit.
1646 if (retval == 0 && !(state->info->flags & UIF_NORMAL_ACTIVE)) {
1647 state->info->flags |= UIF_NORMAL_ACTIVE;
1649 uart_update_termios(state);
1656 static const char *uart_type(struct uart_port *port)
1658 const char *str = NULL;
1660 if (port->ops->type)
1661 str = port->ops->type(port);
1669 #ifdef CONFIG_PROC_FS
1671 static int uart_line_info(char *buf, struct uart_driver *drv, int i)
1673 struct uart_state *state = drv->state + i;
1675 struct uart_port *port = state->port;
1677 unsigned int status;
1683 mmio = port->iotype >= UPIO_MEM;
1684 ret = sprintf(buf, "%d: uart:%s %s%08llX irq:%d",
1685 port->line, uart_type(port),
1686 mmio ? "mmio:0x" : "port:",
1687 mmio ? (unsigned long long)port->mapbase
1688 : (unsigned long long) port->iobase,
1691 if (port->type == PORT_UNKNOWN) {
1696 if (capable(CAP_SYS_ADMIN)) {
1697 mutex_lock(&state->mutex);
1698 pm_state = state->pm_state;
1700 uart_change_pm(state, 0);
1701 spin_lock_irq(&port->lock);
1702 status = port->ops->get_mctrl(port);
1703 spin_unlock_irq(&port->lock);
1705 uart_change_pm(state, pm_state);
1706 mutex_unlock(&state->mutex);
1708 ret += sprintf(buf + ret, " tx:%d rx:%d",
1709 port->icount.tx, port->icount.rx);
1710 if (port->icount.frame)
1711 ret += sprintf(buf + ret, " fe:%d",
1712 port->icount.frame);
1713 if (port->icount.parity)
1714 ret += sprintf(buf + ret, " pe:%d",
1715 port->icount.parity);
1716 if (port->icount.brk)
1717 ret += sprintf(buf + ret, " brk:%d",
1719 if (port->icount.overrun)
1720 ret += sprintf(buf + ret, " oe:%d",
1721 port->icount.overrun);
1723 #define INFOBIT(bit, str) \
1724 if (port->mctrl & (bit)) \
1725 strncat(stat_buf, (str), sizeof(stat_buf) - \
1726 strlen(stat_buf) - 2)
1727 #define STATBIT(bit, str) \
1728 if (status & (bit)) \
1729 strncat(stat_buf, (str), sizeof(stat_buf) - \
1730 strlen(stat_buf) - 2)
1734 INFOBIT(TIOCM_RTS, "|RTS");
1735 STATBIT(TIOCM_CTS, "|CTS");
1736 INFOBIT(TIOCM_DTR, "|DTR");
1737 STATBIT(TIOCM_DSR, "|DSR");
1738 STATBIT(TIOCM_CAR, "|CD");
1739 STATBIT(TIOCM_RNG, "|RI");
1742 strcat(stat_buf, "\n");
1744 ret += sprintf(buf + ret, stat_buf);
1754 static int uart_read_proc(char *page, char **start, off_t off,
1755 int count, int *eof, void *data)
1757 struct tty_driver *ttydrv = data;
1758 struct uart_driver *drv = ttydrv->driver_state;
1762 len += sprintf(page, "serinfo:1.0 driver%s%s revision:%s\n",
1764 for (i = 0; i < drv->nr && len < PAGE_SIZE - 96; i++) {
1765 l = uart_line_info(page + len, drv, i);
1767 if (len + begin > off + count)
1769 if (len + begin < off) {
1776 if (off >= len + begin)
1778 *start = page + (off - begin);
1779 return (count < begin + len - off) ? count : (begin + len - off);
1783 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1785 * uart_console_write - write a console message to a serial port
1786 * @port: the port to write the message
1787 * @s: array of characters
1788 * @count: number of characters in string to write
1789 * @write: function to write character to port
1791 void uart_console_write(struct uart_port *port, const char *s,
1793 void (*putchar)(struct uart_port *, int))
1797 for (i = 0; i < count; i++, s++) {
1799 putchar(port, '\r');
1803 EXPORT_SYMBOL_GPL(uart_console_write);
1806 * Check whether an invalid uart number has been specified, and
1807 * if so, search for the first available port that does have
1810 struct uart_port * __init
1811 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1813 int idx = co->index;
1815 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1816 ports[idx].membase == NULL))
1817 for (idx = 0; idx < nr; idx++)
1818 if (ports[idx].iobase != 0 ||
1819 ports[idx].membase != NULL)
1828 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1829 * @options: pointer to option string
1830 * @baud: pointer to an 'int' variable for the baud rate.
1831 * @parity: pointer to an 'int' variable for the parity.
1832 * @bits: pointer to an 'int' variable for the number of data bits.
1833 * @flow: pointer to an 'int' variable for the flow control character.
1835 * uart_parse_options decodes a string containing the serial console
1836 * options. The format of the string is <baud><parity><bits><flow>,
1840 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1844 *baud = simple_strtoul(s, NULL, 10);
1845 while (*s >= '0' && *s <= '9')
1854 EXPORT_SYMBOL_GPL(uart_parse_options);
1861 static const struct baud_rates baud_rates[] = {
1862 { 921600, B921600 },
1863 { 460800, B460800 },
1864 { 230400, B230400 },
1865 { 115200, B115200 },
1877 * uart_set_options - setup the serial console parameters
1878 * @port: pointer to the serial ports uart_port structure
1879 * @co: console pointer
1881 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1882 * @bits: number of data bits
1883 * @flow: flow control character - 'r' (rts)
1886 uart_set_options(struct uart_port *port, struct console *co,
1887 int baud, int parity, int bits, int flow)
1889 struct ktermios termios;
1890 static struct ktermios dummy;
1894 * Ensure that the serial console lock is initialised
1897 spin_lock_init(&port->lock);
1898 lockdep_set_class(&port->lock, &port_lock_key);
1900 memset(&termios, 0, sizeof(struct ktermios));
1902 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1905 * Construct a cflag setting.
1907 for (i = 0; baud_rates[i].rate; i++)
1908 if (baud_rates[i].rate <= baud)
1911 termios.c_cflag |= baud_rates[i].cflag;
1914 termios.c_cflag |= CS7;
1916 termios.c_cflag |= CS8;
1920 termios.c_cflag |= PARODD;
1923 termios.c_cflag |= PARENB;
1928 termios.c_cflag |= CRTSCTS;
1931 * some uarts on other side don't support no flow control.
1932 * So we set * DTR in host uart to make them happy
1934 port->mctrl |= TIOCM_DTR;
1936 port->ops->set_termios(port, &termios, &dummy);
1938 * Allow the setting of the UART parameters with a NULL console
1942 co->cflag = termios.c_cflag;
1946 EXPORT_SYMBOL_GPL(uart_set_options);
1947 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1949 static void uart_change_pm(struct uart_state *state, int pm_state)
1951 struct uart_port *port = state->port;
1953 if (state->pm_state != pm_state) {
1955 port->ops->pm(port, pm_state, state->pm_state);
1956 state->pm_state = pm_state;
1961 struct uart_port *port;
1962 struct uart_driver *driver;
1965 static int serial_match_port(struct device *dev, void *data)
1967 struct uart_match *match = data;
1968 dev_t devt = MKDEV(match->driver->major, match->driver->minor) + match->port->line;
1970 return dev->devt == devt; /* Actually, only one tty per port */
1973 int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
1975 struct uart_state *state = drv->state + port->line;
1976 struct device *tty_dev;
1977 struct uart_match match = {port, drv};
1979 mutex_lock(&state->mutex);
1981 if (!console_suspend_enabled && uart_console(port)) {
1982 /* we're going to avoid suspending serial console */
1983 mutex_unlock(&state->mutex);
1987 tty_dev = device_find_child(port->dev, &match, serial_match_port);
1988 if (device_may_wakeup(tty_dev)) {
1989 enable_irq_wake(port->irq);
1990 put_device(tty_dev);
1991 mutex_unlock(&state->mutex);
1994 port->suspended = 1;
1996 if (state->info && state->info->flags & UIF_INITIALIZED) {
1997 const struct uart_ops *ops = port->ops;
2000 state->info->flags = (state->info->flags & ~UIF_INITIALIZED)
2003 spin_lock_irq(&port->lock);
2005 ops->set_mctrl(port, 0);
2007 spin_unlock_irq(&port->lock);
2010 * Wait for the transmitter to empty.
2012 for (tries = 3; !ops->tx_empty(port) && tries; tries--)
2015 printk(KERN_ERR "%s%s%s%d: Unable to drain "
2017 port->dev ? port->dev->bus_id : "",
2018 port->dev ? ": " : "",
2019 drv->dev_name, port->line);
2021 ops->shutdown(port);
2025 * Disable the console device before suspending.
2027 if (uart_console(port))
2028 console_stop(port->cons);
2030 uart_change_pm(state, 3);
2032 mutex_unlock(&state->mutex);
2037 int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
2039 struct uart_state *state = drv->state + port->line;
2041 mutex_lock(&state->mutex);
2043 if (!console_suspend_enabled && uart_console(port)) {
2044 /* no need to resume serial console, it wasn't suspended */
2045 mutex_unlock(&state->mutex);
2049 if (!port->suspended) {
2050 disable_irq_wake(port->irq);
2051 mutex_unlock(&state->mutex);
2054 port->suspended = 0;
2057 * Re-enable the console device after suspending.
2059 if (uart_console(port)) {
2060 struct ktermios termios;
2063 * First try to use the console cflag setting.
2065 memset(&termios, 0, sizeof(struct ktermios));
2066 termios.c_cflag = port->cons->cflag;
2069 * If that's unset, use the tty termios setting.
2071 if (state->info && state->info->tty && termios.c_cflag == 0)
2072 termios = *state->info->tty->termios;
2074 uart_change_pm(state, 0);
2075 port->ops->set_termios(port, &termios, NULL);
2076 console_start(port->cons);
2079 if (state->info && state->info->flags & UIF_SUSPENDED) {
2080 const struct uart_ops *ops = port->ops;
2083 uart_change_pm(state, 0);
2084 ops->set_mctrl(port, 0);
2085 ret = ops->startup(port);
2087 uart_change_speed(state, NULL);
2088 spin_lock_irq(&port->lock);
2089 ops->set_mctrl(port, port->mctrl);
2090 ops->start_tx(port);
2091 spin_unlock_irq(&port->lock);
2092 state->info->flags |= UIF_INITIALIZED;
2095 * Failed to resume - maybe hardware went away?
2096 * Clear the "initialized" flag so we won't try
2097 * to call the low level drivers shutdown method.
2099 uart_shutdown(state);
2102 state->info->flags &= ~UIF_SUSPENDED;
2105 mutex_unlock(&state->mutex);
2111 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2115 switch (port->iotype) {
2117 snprintf(address, sizeof(address),
2118 "I/O 0x%x", port->iobase);
2121 snprintf(address, sizeof(address),
2122 "I/O 0x%x offset 0x%x", port->iobase, port->hub6);
2129 snprintf(address, sizeof(address),
2130 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2133 strlcpy(address, "*unknown*", sizeof(address));
2137 printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2138 port->dev ? port->dev->bus_id : "",
2139 port->dev ? ": " : "",
2140 drv->dev_name, port->line, address, port->irq, uart_type(port));
2144 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2145 struct uart_port *port)
2150 * If there isn't a port here, don't do anything further.
2152 if (!port->iobase && !port->mapbase && !port->membase)
2156 * Now do the auto configuration stuff. Note that config_port
2157 * is expected to claim the resources and map the port for us.
2159 flags = UART_CONFIG_TYPE;
2160 if (port->flags & UPF_AUTO_IRQ)
2161 flags |= UART_CONFIG_IRQ;
2162 if (port->flags & UPF_BOOT_AUTOCONF) {
2163 port->type = PORT_UNKNOWN;
2164 port->ops->config_port(port, flags);
2167 if (port->type != PORT_UNKNOWN) {
2168 unsigned long flags;
2170 uart_report_port(drv, port);
2172 /* Power up port for set_mctrl() */
2173 uart_change_pm(state, 0);
2176 * Ensure that the modem control lines are de-activated.
2177 * keep the DTR setting that is set in uart_set_options()
2178 * We probably don't need a spinlock around this, but
2180 spin_lock_irqsave(&port->lock, flags);
2181 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2182 spin_unlock_irqrestore(&port->lock, flags);
2185 * If this driver supports console, and it hasn't been
2186 * successfully registered yet, try to re-register it.
2187 * It may be that the port was not available.
2189 if (port->cons && !(port->cons->flags & CON_ENABLED))
2190 register_console(port->cons);
2193 * Power down all ports by default, except the
2194 * console if we have one.
2196 if (!uart_console(port))
2197 uart_change_pm(state, 3);
2201 #ifdef CONFIG_CONSOLE_POLL
2203 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2205 struct uart_driver *drv = driver->driver_state;
2206 struct uart_state *state = drv->state + line;
2207 struct uart_port *port;
2213 if (!state || !state->port)
2217 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2221 uart_parse_options(options, &baud, &parity, &bits, &flow);
2222 return uart_set_options(port, NULL, baud, parity, bits, flow);
2228 static int uart_poll_get_char(struct tty_driver *driver, int line)
2230 struct uart_driver *drv = driver->driver_state;
2231 struct uart_state *state = drv->state + line;
2232 struct uart_port *port;
2234 if (!state || !state->port)
2238 return port->ops->poll_get_char(port);
2241 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2243 struct uart_driver *drv = driver->driver_state;
2244 struct uart_state *state = drv->state + line;
2245 struct uart_port *port;
2247 if (!state || !state->port)
2251 port->ops->poll_put_char(port, ch);
2255 static const struct tty_operations uart_ops = {
2257 .close = uart_close,
2258 .write = uart_write,
2259 .put_char = uart_put_char,
2260 .flush_chars = uart_flush_chars,
2261 .write_room = uart_write_room,
2262 .chars_in_buffer= uart_chars_in_buffer,
2263 .flush_buffer = uart_flush_buffer,
2264 .ioctl = uart_ioctl,
2265 .throttle = uart_throttle,
2266 .unthrottle = uart_unthrottle,
2267 .send_xchar = uart_send_xchar,
2268 .set_termios = uart_set_termios,
2270 .start = uart_start,
2271 .hangup = uart_hangup,
2272 .break_ctl = uart_break_ctl,
2273 .wait_until_sent= uart_wait_until_sent,
2274 #ifdef CONFIG_PROC_FS
2275 .read_proc = uart_read_proc,
2277 .tiocmget = uart_tiocmget,
2278 .tiocmset = uart_tiocmset,
2279 #ifdef CONFIG_CONSOLE_POLL
2280 .poll_init = uart_poll_init,
2281 .poll_get_char = uart_poll_get_char,
2282 .poll_put_char = uart_poll_put_char,
2287 * uart_register_driver - register a driver with the uart core layer
2288 * @drv: low level driver structure
2290 * Register a uart driver with the core driver. We in turn register
2291 * with the tty layer, and initialise the core driver per-port state.
2293 * We have a proc file in /proc/tty/driver which is named after the
2296 * drv->port should be NULL, and the per-port structures should be
2297 * registered using uart_add_one_port after this call has succeeded.
2299 int uart_register_driver(struct uart_driver *drv)
2301 struct tty_driver *normal = NULL;
2307 * Maybe we should be using a slab cache for this, especially if
2308 * we have a large number of ports to handle.
2310 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2315 normal = alloc_tty_driver(drv->nr);
2319 drv->tty_driver = normal;
2321 normal->owner = drv->owner;
2322 normal->driver_name = drv->driver_name;
2323 normal->name = drv->dev_name;
2324 normal->major = drv->major;
2325 normal->minor_start = drv->minor;
2326 normal->type = TTY_DRIVER_TYPE_SERIAL;
2327 normal->subtype = SERIAL_TYPE_NORMAL;
2328 normal->init_termios = tty_std_termios;
2329 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2330 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2331 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2332 normal->driver_state = drv;
2333 tty_set_operations(normal, &uart_ops);
2336 * Initialise the UART state(s).
2338 for (i = 0; i < drv->nr; i++) {
2339 struct uart_state *state = drv->state + i;
2341 state->close_delay = 500; /* .5 seconds */
2342 state->closing_wait = 30000; /* 30 seconds */
2344 mutex_init(&state->mutex);
2347 retval = tty_register_driver(normal);
2350 put_tty_driver(normal);
2357 * uart_unregister_driver - remove a driver from the uart core layer
2358 * @drv: low level driver structure
2360 * Remove all references to a driver from the core driver. The low
2361 * level driver must have removed all its ports via the
2362 * uart_remove_one_port() if it registered them with uart_add_one_port().
2363 * (ie, drv->port == NULL)
2365 void uart_unregister_driver(struct uart_driver *drv)
2367 struct tty_driver *p = drv->tty_driver;
2368 tty_unregister_driver(p);
2371 drv->tty_driver = NULL;
2374 struct tty_driver *uart_console_device(struct console *co, int *index)
2376 struct uart_driver *p = co->data;
2378 return p->tty_driver;
2382 * uart_add_one_port - attach a driver-defined port structure
2383 * @drv: pointer to the uart low level driver structure for this port
2384 * @port: uart port structure to use for this port.
2386 * This allows the driver to register its own uart_port structure
2387 * with the core driver. The main purpose is to allow the low
2388 * level uart drivers to expand uart_port, rather than having yet
2389 * more levels of structures.
2391 int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
2393 struct uart_state *state;
2395 struct device *tty_dev;
2397 BUG_ON(in_interrupt());
2399 if (port->line >= drv->nr)
2402 state = drv->state + port->line;
2404 mutex_lock(&port_mutex);
2405 mutex_lock(&state->mutex);
2412 state->pm_state = -1;
2414 port->cons = drv->cons;
2415 port->info = state->info;
2418 * If this port is a console, then the spinlock is already
2421 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
2422 spin_lock_init(&port->lock);
2423 lockdep_set_class(&port->lock, &port_lock_key);
2426 uart_configure_port(drv, state, port);
2429 * Register the port whether it's detected or not. This allows
2430 * setserial to be used to alter this ports parameters.
2432 tty_dev = tty_register_device(drv->tty_driver, port->line, port->dev);
2433 if (likely(!IS_ERR(tty_dev))) {
2434 device_init_wakeup(tty_dev, 1);
2435 device_set_wakeup_enable(tty_dev, 0);
2437 printk(KERN_ERR "Cannot register tty device on line %d\n",
2441 * Ensure UPF_DEAD is not set.
2443 port->flags &= ~UPF_DEAD;
2446 mutex_unlock(&state->mutex);
2447 mutex_unlock(&port_mutex);
2453 * uart_remove_one_port - detach a driver defined port structure
2454 * @drv: pointer to the uart low level driver structure for this port
2455 * @port: uart port structure for this port
2457 * This unhooks (and hangs up) the specified port structure from the
2458 * core driver. No further calls will be made to the low-level code
2461 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
2463 struct uart_state *state = drv->state + port->line;
2464 struct uart_info *info;
2466 BUG_ON(in_interrupt());
2468 if (state->port != port)
2469 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2472 mutex_lock(&port_mutex);
2475 * Mark the port "dead" - this prevents any opens from
2476 * succeeding while we shut down the port.
2478 mutex_lock(&state->mutex);
2479 port->flags |= UPF_DEAD;
2480 mutex_unlock(&state->mutex);
2483 * Remove the devices from the tty layer
2485 tty_unregister_device(drv->tty_driver, port->line);
2488 if (info && info->tty)
2489 tty_vhangup(info->tty);
2492 * All users of this port should now be disconnected from
2493 * this driver, and the port shut down. We should be the
2494 * only thread fiddling with this port from now on.
2499 * Free the port IO and memory resources, if any.
2501 if (port->type != PORT_UNKNOWN)
2502 port->ops->release_port(port);
2505 * Indicate that there isn't a port here anymore.
2507 port->type = PORT_UNKNOWN;
2510 * Kill the tasklet, and free resources.
2513 tasklet_kill(&info->tlet);
2518 mutex_unlock(&port_mutex);
2524 * Are the two ports equivalent?
2526 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2528 if (port1->iotype != port2->iotype)
2531 switch (port1->iotype) {
2533 return (port1->iobase == port2->iobase);
2535 return (port1->iobase == port2->iobase) &&
2536 (port1->hub6 == port2->hub6);
2542 return (port1->mapbase == port2->mapbase);
2546 EXPORT_SYMBOL(uart_match_port);
2548 EXPORT_SYMBOL(uart_write_wakeup);
2549 EXPORT_SYMBOL(uart_register_driver);
2550 EXPORT_SYMBOL(uart_unregister_driver);
2551 EXPORT_SYMBOL(uart_suspend_port);
2552 EXPORT_SYMBOL(uart_resume_port);
2553 EXPORT_SYMBOL(uart_add_one_port);
2554 EXPORT_SYMBOL(uart_remove_one_port);
2556 MODULE_DESCRIPTION("Serial driver core");
2557 MODULE_LICENSE("GPL");