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
;
917 BUG_ON(!kernel_locked());
919 mutex_lock(&state
->mutex
);
921 if (port
->type
!= PORT_UNKNOWN
)
922 port
->ops
->break_ctl(port
, break_state
);
924 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 under the BKL. 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
;
1072 BUG_ON(!kernel_locked());
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
);
1149 static void uart_set_termios(struct tty_struct
*tty
,
1150 struct ktermios
*old_termios
)
1152 struct uart_state
*state
= tty
->driver_data
;
1153 unsigned long flags
;
1154 unsigned int cflag
= tty
->termios
->c_cflag
;
1156 BUG_ON(!kernel_locked());
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)
1171 uart_change_speed(state
, old_termios
);
1173 /* Handle transition to B0 status */
1174 if ((old_termios
->c_cflag
& CBAUD
) && !(cflag
& CBAUD
))
1175 uart_clear_mctrl(state
->port
, TIOCM_RTS
| TIOCM_DTR
);
1177 /* Handle transition away from B0 status */
1178 if (!(old_termios
->c_cflag
& CBAUD
) && (cflag
& CBAUD
)) {
1179 unsigned int mask
= TIOCM_DTR
;
1180 if (!(cflag
& CRTSCTS
) ||
1181 !test_bit(TTY_THROTTLED
, &tty
->flags
))
1183 uart_set_mctrl(state
->port
, mask
);
1186 /* Handle turning off CRTSCTS */
1187 if ((old_termios
->c_cflag
& CRTSCTS
) && !(cflag
& CRTSCTS
)) {
1188 spin_lock_irqsave(&state
->port
->lock
, flags
);
1189 tty
->hw_stopped
= 0;
1191 spin_unlock_irqrestore(&state
->port
->lock
, flags
);
1194 /* Handle turning on CRTSCTS */
1195 if (!(old_termios
->c_cflag
& CRTSCTS
) && (cflag
& CRTSCTS
)) {
1196 spin_lock_irqsave(&state
->port
->lock
, flags
);
1197 if (!(state
->port
->ops
->get_mctrl(state
->port
) & TIOCM_CTS
)) {
1198 tty
->hw_stopped
= 1;
1199 state
->port
->ops
->stop_tx(state
->port
);
1201 spin_unlock_irqrestore(&state
->port
->lock
, flags
);
1206 * No need to wake up processes in open wait, since they
1207 * sample the CLOCAL flag once, and don't recheck it.
1208 * XXX It's not clear whether the current behavior is correct
1209 * or not. Hence, this may change.....
1211 if (!(old_termios
->c_cflag
& CLOCAL
) &&
1212 (tty
->termios
->c_cflag
& CLOCAL
))
1213 wake_up_interruptible(&state
->info
->open_wait
);
1218 * In 2.4.5, calls to this will be serialized via the BKL in
1219 * linux/drivers/char/tty_io.c:tty_release()
1220 * linux/drivers/char/tty_io.c:do_tty_handup()
1222 static void uart_close(struct tty_struct
*tty
, struct file
*filp
)
1224 struct uart_state
*state
= tty
->driver_data
;
1225 struct uart_port
*port
;
1227 BUG_ON(!kernel_locked());
1229 if (!state
|| !state
->port
)
1234 pr_debug("uart_close(%d) called\n", port
->line
);
1236 mutex_lock(&state
->mutex
);
1238 if (tty_hung_up_p(filp
))
1241 if ((tty
->count
== 1) && (state
->count
!= 1)) {
1243 * Uh, oh. tty->count is 1, which means that the tty
1244 * structure will be freed. state->count should always
1245 * be one in these conditions. If it's greater than
1246 * one, we've got real problems, since it means the
1247 * serial port won't be shutdown.
1249 printk(KERN_ERR
"uart_close: bad serial port count; tty->count is 1, "
1250 "state->count is %d\n", state
->count
);
1253 if (--state
->count
< 0) {
1254 printk(KERN_ERR
"uart_close: bad serial port count for %s: %d\n",
1255 tty
->name
, state
->count
);
1262 * Now we wait for the transmit buffer to clear; and we notify
1263 * the line discipline to only process XON/XOFF characters by
1264 * setting tty->closing.
1268 if (state
->closing_wait
!= USF_CLOSING_WAIT_NONE
)
1269 tty_wait_until_sent(tty
, msecs_to_jiffies(state
->closing_wait
));
1272 * At this point, we stop accepting input. To do this, we
1273 * disable the receive line status interrupts.
1275 if (state
->info
->flags
& UIF_INITIALIZED
) {
1276 unsigned long flags
;
1277 spin_lock_irqsave(&port
->lock
, flags
);
1278 port
->ops
->stop_rx(port
);
1279 spin_unlock_irqrestore(&port
->lock
, flags
);
1281 * Before we drop DTR, make sure the UART transmitter
1282 * has completely drained; this is especially
1283 * important if there is a transmit FIFO!
1285 uart_wait_until_sent(tty
, port
->timeout
);
1288 uart_shutdown(state
);
1289 uart_flush_buffer(tty
);
1291 tty_ldisc_flush(tty
);
1294 state
->info
->tty
= NULL
;
1296 if (state
->info
->blocked_open
) {
1297 if (state
->close_delay
)
1298 msleep_interruptible(state
->close_delay
);
1299 } else if (!uart_console(port
)) {
1300 uart_change_pm(state
, 3);
1304 * Wake up anyone trying to open this port.
1306 state
->info
->flags
&= ~UIF_NORMAL_ACTIVE
;
1307 wake_up_interruptible(&state
->info
->open_wait
);
1310 mutex_unlock(&state
->mutex
);
1313 static void uart_wait_until_sent(struct tty_struct
*tty
, int timeout
)
1315 struct uart_state
*state
= tty
->driver_data
;
1316 struct uart_port
*port
= state
->port
;
1317 unsigned long char_time
, expire
;
1319 BUG_ON(!kernel_locked());
1321 if (port
->type
== PORT_UNKNOWN
|| port
->fifosize
== 0)
1325 * Set the check interval to be 1/5 of the estimated time to
1326 * send a single character, and make it at least 1. The check
1327 * interval should also be less than the timeout.
1329 * Note: we have to use pretty tight timings here to satisfy
1332 char_time
= (port
->timeout
- HZ
/50) / port
->fifosize
;
1333 char_time
= char_time
/ 5;
1336 if (timeout
&& timeout
< char_time
)
1337 char_time
= timeout
;
1340 * If the transmitter hasn't cleared in twice the approximate
1341 * amount of time to send the entire FIFO, it probably won't
1342 * ever clear. This assumes the UART isn't doing flow
1343 * control, which is currently the case. Hence, if it ever
1344 * takes longer than port->timeout, this is probably due to a
1345 * UART bug of some kind. So, we clamp the timeout parameter at
1348 if (timeout
== 0 || timeout
> 2 * port
->timeout
)
1349 timeout
= 2 * port
->timeout
;
1351 expire
= jiffies
+ timeout
;
1353 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1354 port
->line
, jiffies
, expire
);
1357 * Check whether the transmitter is empty every 'char_time'.
1358 * 'timeout' / 'expire' give us the maximum amount of time
1361 while (!port
->ops
->tx_empty(port
)) {
1362 msleep_interruptible(jiffies_to_msecs(char_time
));
1363 if (signal_pending(current
))
1365 if (time_after(jiffies
, expire
))
1368 set_current_state(TASK_RUNNING
); /* might not be needed */
1372 * This is called with the BKL held in
1373 * linux/drivers/char/tty_io.c:do_tty_hangup()
1374 * We're called from the eventd thread, so we can sleep for
1375 * a _short_ time only.
1377 static void uart_hangup(struct tty_struct
*tty
)
1379 struct uart_state
*state
= tty
->driver_data
;
1381 BUG_ON(!kernel_locked());
1382 pr_debug("uart_hangup(%d)\n", state
->port
->line
);
1384 mutex_lock(&state
->mutex
);
1385 if (state
->info
&& state
->info
->flags
& UIF_NORMAL_ACTIVE
) {
1386 uart_flush_buffer(tty
);
1387 uart_shutdown(state
);
1389 state
->info
->flags
&= ~UIF_NORMAL_ACTIVE
;
1390 state
->info
->tty
= NULL
;
1391 wake_up_interruptible(&state
->info
->open_wait
);
1392 wake_up_interruptible(&state
->info
->delta_msr_wait
);
1394 mutex_unlock(&state
->mutex
);
1398 * Copy across the serial console cflag setting into the termios settings
1399 * for the initial open of the port. This allows continuity between the
1400 * kernel settings, and the settings init adopts when it opens the port
1401 * for the first time.
1403 static void uart_update_termios(struct uart_state
*state
)
1405 struct tty_struct
*tty
= state
->info
->tty
;
1406 struct uart_port
*port
= state
->port
;
1408 if (uart_console(port
) && port
->cons
->cflag
) {
1409 tty
->termios
->c_cflag
= port
->cons
->cflag
;
1410 port
->cons
->cflag
= 0;
1414 * If the device failed to grab its irq resources,
1415 * or some other error occurred, don't try to talk
1416 * to the port hardware.
1418 if (!(tty
->flags
& (1 << TTY_IO_ERROR
))) {
1420 * Make termios settings take effect.
1422 uart_change_speed(state
, NULL
);
1425 * And finally enable the RTS and DTR signals.
1427 if (tty
->termios
->c_cflag
& CBAUD
)
1428 uart_set_mctrl(port
, TIOCM_DTR
| TIOCM_RTS
);
1433 * Block the open until the port is ready. We must be called with
1434 * the per-port semaphore held.
1437 uart_block_til_ready(struct file
*filp
, struct uart_state
*state
)
1439 DECLARE_WAITQUEUE(wait
, current
);
1440 struct uart_info
*info
= state
->info
;
1441 struct uart_port
*port
= state
->port
;
1444 info
->blocked_open
++;
1447 add_wait_queue(&info
->open_wait
, &wait
);
1449 set_current_state(TASK_INTERRUPTIBLE
);
1452 * If we have been hung up, tell userspace/restart open.
1454 if (tty_hung_up_p(filp
) || info
->tty
== NULL
)
1458 * If the port has been closed, tell userspace/restart open.
1460 if (!(info
->flags
& UIF_INITIALIZED
))
1464 * If non-blocking mode is set, or CLOCAL mode is set,
1465 * we don't want to wait for the modem status lines to
1466 * indicate that the port is ready.
1468 * Also, if the port is not enabled/configured, we want
1469 * to allow the open to succeed here. Note that we will
1470 * have set TTY_IO_ERROR for a non-existant port.
1472 if ((filp
->f_flags
& O_NONBLOCK
) ||
1473 (info
->tty
->termios
->c_cflag
& CLOCAL
) ||
1474 (info
->tty
->flags
& (1 << TTY_IO_ERROR
)))
1478 * Set DTR to allow modem to know we're waiting. Do
1479 * not set RTS here - we want to make sure we catch
1480 * the data from the modem.
1482 if (info
->tty
->termios
->c_cflag
& CBAUD
)
1483 uart_set_mctrl(port
, TIOCM_DTR
);
1486 * and wait for the carrier to indicate that the
1487 * modem is ready for us.
1489 spin_lock_irq(&port
->lock
);
1490 port
->ops
->enable_ms(port
);
1491 mctrl
= port
->ops
->get_mctrl(port
);
1492 spin_unlock_irq(&port
->lock
);
1493 if (mctrl
& TIOCM_CAR
)
1496 mutex_unlock(&state
->mutex
);
1498 mutex_lock(&state
->mutex
);
1500 if (signal_pending(current
))
1503 set_current_state(TASK_RUNNING
);
1504 remove_wait_queue(&info
->open_wait
, &wait
);
1507 info
->blocked_open
--;
1509 if (signal_pending(current
))
1510 return -ERESTARTSYS
;
1512 if (!info
->tty
|| tty_hung_up_p(filp
))
1518 static struct uart_state
*uart_get(struct uart_driver
*drv
, int line
)
1520 struct uart_state
*state
;
1523 state
= drv
->state
+ line
;
1524 if (mutex_lock_interruptible(&state
->mutex
)) {
1530 if (!state
->port
|| state
->port
->flags
& UPF_DEAD
) {
1536 state
->info
= kzalloc(sizeof(struct uart_info
), GFP_KERNEL
);
1538 init_waitqueue_head(&state
->info
->open_wait
);
1539 init_waitqueue_head(&state
->info
->delta_msr_wait
);
1542 * Link the info into the other structures.
1544 state
->port
->info
= state
->info
;
1546 tasklet_init(&state
->info
->tlet
, uart_tasklet_action
,
1547 (unsigned long)state
);
1557 mutex_unlock(&state
->mutex
);
1559 return ERR_PTR(ret
);
1563 * calls to uart_open are serialised by the BKL in
1564 * fs/char_dev.c:chrdev_open()
1565 * Note that if this fails, then uart_close() _will_ be called.
1567 * In time, we want to scrap the "opening nonpresent ports"
1568 * behaviour and implement an alternative way for setserial
1569 * to set base addresses/ports/types. This will allow us to
1570 * get rid of a certain amount of extra tests.
1572 static int uart_open(struct tty_struct
*tty
, struct file
*filp
)
1574 struct uart_driver
*drv
= (struct uart_driver
*)tty
->driver
->driver_state
;
1575 struct uart_state
*state
;
1576 int retval
, line
= tty
->index
;
1578 BUG_ON(!kernel_locked());
1579 pr_debug("uart_open(%d) called\n", line
);
1582 * tty->driver->num won't change, so we won't fail here with
1583 * tty->driver_data set to something non-NULL (and therefore
1584 * we won't get caught by uart_close()).
1587 if (line
>= tty
->driver
->num
)
1591 * We take the semaphore inside uart_get to guarantee that we won't
1592 * be re-entered while allocating the info structure, or while we
1593 * request any IRQs that the driver may need. This also has the nice
1594 * side-effect that it delays the action of uart_hangup, so we can
1595 * guarantee that info->tty will always contain something reasonable.
1597 state
= uart_get(drv
, line
);
1598 if (IS_ERR(state
)) {
1599 retval
= PTR_ERR(state
);
1604 * Once we set tty->driver_data here, we are guaranteed that
1605 * uart_close() will decrement the driver module use count.
1606 * Any failures from here onwards should not touch the count.
1608 tty
->driver_data
= state
;
1609 tty
->low_latency
= (state
->port
->flags
& UPF_LOW_LATENCY
) ? 1 : 0;
1611 state
->info
->tty
= tty
;
1614 * If the port is in the middle of closing, bail out now.
1616 if (tty_hung_up_p(filp
)) {
1619 mutex_unlock(&state
->mutex
);
1624 * Make sure the device is in D0 state.
1626 if (state
->count
== 1)
1627 uart_change_pm(state
, 0);
1630 * Start up the serial port.
1632 retval
= uart_startup(state
, 0);
1635 * If we succeeded, wait until the port is ready.
1638 retval
= uart_block_til_ready(filp
, state
);
1639 mutex_unlock(&state
->mutex
);
1642 * If this is the first open to succeed, adjust things to suit.
1644 if (retval
== 0 && !(state
->info
->flags
& UIF_NORMAL_ACTIVE
)) {
1645 state
->info
->flags
|= UIF_NORMAL_ACTIVE
;
1647 uart_update_termios(state
);
1654 static const char *uart_type(struct uart_port
*port
)
1656 const char *str
= NULL
;
1658 if (port
->ops
->type
)
1659 str
= port
->ops
->type(port
);
1667 #ifdef CONFIG_PROC_FS
1669 static int uart_line_info(char *buf
, struct uart_driver
*drv
, int i
)
1671 struct uart_state
*state
= drv
->state
+ i
;
1673 struct uart_port
*port
= state
->port
;
1675 unsigned int status
;
1681 mmio
= port
->iotype
>= UPIO_MEM
;
1682 ret
= sprintf(buf
, "%d: uart:%s %s%08llX irq:%d",
1683 port
->line
, uart_type(port
),
1684 mmio
? "mmio:0x" : "port:",
1685 mmio
? (unsigned long long)port
->mapbase
1686 : (unsigned long long) port
->iobase
,
1689 if (port
->type
== PORT_UNKNOWN
) {
1694 if (capable(CAP_SYS_ADMIN
)) {
1695 mutex_lock(&state
->mutex
);
1696 pm_state
= state
->pm_state
;
1698 uart_change_pm(state
, 0);
1699 spin_lock_irq(&port
->lock
);
1700 status
= port
->ops
->get_mctrl(port
);
1701 spin_unlock_irq(&port
->lock
);
1703 uart_change_pm(state
, pm_state
);
1704 mutex_unlock(&state
->mutex
);
1706 ret
+= sprintf(buf
+ ret
, " tx:%d rx:%d",
1707 port
->icount
.tx
, port
->icount
.rx
);
1708 if (port
->icount
.frame
)
1709 ret
+= sprintf(buf
+ ret
, " fe:%d",
1710 port
->icount
.frame
);
1711 if (port
->icount
.parity
)
1712 ret
+= sprintf(buf
+ ret
, " pe:%d",
1713 port
->icount
.parity
);
1714 if (port
->icount
.brk
)
1715 ret
+= sprintf(buf
+ ret
, " brk:%d",
1717 if (port
->icount
.overrun
)
1718 ret
+= sprintf(buf
+ ret
, " oe:%d",
1719 port
->icount
.overrun
);
1721 #define INFOBIT(bit, str) \
1722 if (port->mctrl & (bit)) \
1723 strncat(stat_buf, (str), sizeof(stat_buf) - \
1724 strlen(stat_buf) - 2)
1725 #define STATBIT(bit, str) \
1726 if (status & (bit)) \
1727 strncat(stat_buf, (str), sizeof(stat_buf) - \
1728 strlen(stat_buf) - 2)
1732 INFOBIT(TIOCM_RTS
, "|RTS");
1733 STATBIT(TIOCM_CTS
, "|CTS");
1734 INFOBIT(TIOCM_DTR
, "|DTR");
1735 STATBIT(TIOCM_DSR
, "|DSR");
1736 STATBIT(TIOCM_CAR
, "|CD");
1737 STATBIT(TIOCM_RNG
, "|RI");
1740 strcat(stat_buf
, "\n");
1742 ret
+= sprintf(buf
+ ret
, stat_buf
);
1752 static int uart_read_proc(char *page
, char **start
, off_t off
,
1753 int count
, int *eof
, void *data
)
1755 struct tty_driver
*ttydrv
= data
;
1756 struct uart_driver
*drv
= ttydrv
->driver_state
;
1760 len
+= sprintf(page
, "serinfo:1.0 driver%s%s revision:%s\n",
1762 for (i
= 0; i
< drv
->nr
&& len
< PAGE_SIZE
- 96; i
++) {
1763 l
= uart_line_info(page
+ len
, drv
, i
);
1765 if (len
+ begin
> off
+ count
)
1767 if (len
+ begin
< off
) {
1774 if (off
>= len
+ begin
)
1776 *start
= page
+ (off
- begin
);
1777 return (count
< begin
+ len
- off
) ? count
: (begin
+ len
- off
);
1781 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1783 * uart_console_write - write a console message to a serial port
1784 * @port: the port to write the message
1785 * @s: array of characters
1786 * @count: number of characters in string to write
1787 * @write: function to write character to port
1789 void uart_console_write(struct uart_port
*port
, const char *s
,
1791 void (*putchar
)(struct uart_port
*, int))
1795 for (i
= 0; i
< count
; i
++, s
++) {
1797 putchar(port
, '\r');
1801 EXPORT_SYMBOL_GPL(uart_console_write
);
1804 * Check whether an invalid uart number has been specified, and
1805 * if so, search for the first available port that does have
1808 struct uart_port
* __init
1809 uart_get_console(struct uart_port
*ports
, int nr
, struct console
*co
)
1811 int idx
= co
->index
;
1813 if (idx
< 0 || idx
>= nr
|| (ports
[idx
].iobase
== 0 &&
1814 ports
[idx
].membase
== NULL
))
1815 for (idx
= 0; idx
< nr
; idx
++)
1816 if (ports
[idx
].iobase
!= 0 ||
1817 ports
[idx
].membase
!= NULL
)
1826 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1827 * @options: pointer to option string
1828 * @baud: pointer to an 'int' variable for the baud rate.
1829 * @parity: pointer to an 'int' variable for the parity.
1830 * @bits: pointer to an 'int' variable for the number of data bits.
1831 * @flow: pointer to an 'int' variable for the flow control character.
1833 * uart_parse_options decodes a string containing the serial console
1834 * options. The format of the string is <baud><parity><bits><flow>,
1838 uart_parse_options(char *options
, int *baud
, int *parity
, int *bits
, int *flow
)
1842 *baud
= simple_strtoul(s
, NULL
, 10);
1843 while (*s
>= '0' && *s
<= '9')
1852 EXPORT_SYMBOL_GPL(uart_parse_options
);
1859 static const struct baud_rates baud_rates
[] = {
1860 { 921600, B921600
},
1861 { 460800, B460800
},
1862 { 230400, B230400
},
1863 { 115200, B115200
},
1875 * uart_set_options - setup the serial console parameters
1876 * @port: pointer to the serial ports uart_port structure
1877 * @co: console pointer
1879 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1880 * @bits: number of data bits
1881 * @flow: flow control character - 'r' (rts)
1884 uart_set_options(struct uart_port
*port
, struct console
*co
,
1885 int baud
, int parity
, int bits
, int flow
)
1887 struct ktermios termios
;
1888 static struct ktermios dummy
;
1892 * Ensure that the serial console lock is initialised
1895 spin_lock_init(&port
->lock
);
1896 lockdep_set_class(&port
->lock
, &port_lock_key
);
1898 memset(&termios
, 0, sizeof(struct ktermios
));
1900 termios
.c_cflag
= CREAD
| HUPCL
| CLOCAL
;
1903 * Construct a cflag setting.
1905 for (i
= 0; baud_rates
[i
].rate
; i
++)
1906 if (baud_rates
[i
].rate
<= baud
)
1909 termios
.c_cflag
|= baud_rates
[i
].cflag
;
1912 termios
.c_cflag
|= CS7
;
1914 termios
.c_cflag
|= CS8
;
1918 termios
.c_cflag
|= PARODD
;
1921 termios
.c_cflag
|= PARENB
;
1926 termios
.c_cflag
|= CRTSCTS
;
1929 * some uarts on other side don't support no flow control.
1930 * So we set * DTR in host uart to make them happy
1932 port
->mctrl
|= TIOCM_DTR
;
1934 port
->ops
->set_termios(port
, &termios
, &dummy
);
1936 * Allow the setting of the UART parameters with a NULL console
1940 co
->cflag
= termios
.c_cflag
;
1944 EXPORT_SYMBOL_GPL(uart_set_options
);
1945 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1947 static void uart_change_pm(struct uart_state
*state
, int pm_state
)
1949 struct uart_port
*port
= state
->port
;
1951 if (state
->pm_state
!= pm_state
) {
1953 port
->ops
->pm(port
, pm_state
, state
->pm_state
);
1954 state
->pm_state
= pm_state
;
1959 struct uart_port
*port
;
1960 struct uart_driver
*driver
;
1963 static int serial_match_port(struct device
*dev
, void *data
)
1965 struct uart_match
*match
= data
;
1966 dev_t devt
= MKDEV(match
->driver
->major
, match
->driver
->minor
) + match
->port
->line
;
1968 return dev
->devt
== devt
; /* Actually, only one tty per port */
1971 int uart_suspend_port(struct uart_driver
*drv
, struct uart_port
*port
)
1973 struct uart_state
*state
= drv
->state
+ port
->line
;
1974 struct device
*tty_dev
;
1975 struct uart_match match
= {port
, drv
};
1977 mutex_lock(&state
->mutex
);
1979 if (!console_suspend_enabled
&& uart_console(port
)) {
1980 /* we're going to avoid suspending serial console */
1981 mutex_unlock(&state
->mutex
);
1985 tty_dev
= device_find_child(port
->dev
, &match
, serial_match_port
);
1986 if (device_may_wakeup(tty_dev
)) {
1987 enable_irq_wake(port
->irq
);
1988 put_device(tty_dev
);
1989 mutex_unlock(&state
->mutex
);
1992 port
->suspended
= 1;
1994 if (state
->info
&& state
->info
->flags
& UIF_INITIALIZED
) {
1995 const struct uart_ops
*ops
= port
->ops
;
1998 state
->info
->flags
= (state
->info
->flags
& ~UIF_INITIALIZED
)
2001 spin_lock_irq(&port
->lock
);
2003 ops
->set_mctrl(port
, 0);
2005 spin_unlock_irq(&port
->lock
);
2008 * Wait for the transmitter to empty.
2010 for (tries
= 3; !ops
->tx_empty(port
) && tries
; tries
--)
2013 printk(KERN_ERR
"%s%s%s%d: Unable to drain "
2015 port
->dev
? port
->dev
->bus_id
: "",
2016 port
->dev
? ": " : "",
2017 drv
->dev_name
, port
->line
);
2019 ops
->shutdown(port
);
2023 * Disable the console device before suspending.
2025 if (uart_console(port
))
2026 console_stop(port
->cons
);
2028 uart_change_pm(state
, 3);
2030 mutex_unlock(&state
->mutex
);
2035 int uart_resume_port(struct uart_driver
*drv
, struct uart_port
*port
)
2037 struct uart_state
*state
= drv
->state
+ port
->line
;
2039 mutex_lock(&state
->mutex
);
2041 if (!console_suspend_enabled
&& uart_console(port
)) {
2042 /* no need to resume serial console, it wasn't suspended */
2043 mutex_unlock(&state
->mutex
);
2047 if (!port
->suspended
) {
2048 disable_irq_wake(port
->irq
);
2049 mutex_unlock(&state
->mutex
);
2052 port
->suspended
= 0;
2055 * Re-enable the console device after suspending.
2057 if (uart_console(port
)) {
2058 struct ktermios termios
;
2061 * First try to use the console cflag setting.
2063 memset(&termios
, 0, sizeof(struct ktermios
));
2064 termios
.c_cflag
= port
->cons
->cflag
;
2067 * If that's unset, use the tty termios setting.
2069 if (state
->info
&& state
->info
->tty
&& termios
.c_cflag
== 0)
2070 termios
= *state
->info
->tty
->termios
;
2072 uart_change_pm(state
, 0);
2073 port
->ops
->set_termios(port
, &termios
, NULL
);
2074 console_start(port
->cons
);
2077 if (state
->info
&& state
->info
->flags
& UIF_SUSPENDED
) {
2078 const struct uart_ops
*ops
= port
->ops
;
2081 uart_change_pm(state
, 0);
2082 ops
->set_mctrl(port
, 0);
2083 ret
= ops
->startup(port
);
2085 uart_change_speed(state
, NULL
);
2086 spin_lock_irq(&port
->lock
);
2087 ops
->set_mctrl(port
, port
->mctrl
);
2088 ops
->start_tx(port
);
2089 spin_unlock_irq(&port
->lock
);
2090 state
->info
->flags
|= UIF_INITIALIZED
;
2093 * Failed to resume - maybe hardware went away?
2094 * Clear the "initialized" flag so we won't try
2095 * to call the low level drivers shutdown method.
2097 uart_shutdown(state
);
2100 state
->info
->flags
&= ~UIF_SUSPENDED
;
2103 mutex_unlock(&state
->mutex
);
2109 uart_report_port(struct uart_driver
*drv
, struct uart_port
*port
)
2113 switch (port
->iotype
) {
2115 snprintf(address
, sizeof(address
),
2116 "I/O 0x%x", port
->iobase
);
2119 snprintf(address
, sizeof(address
),
2120 "I/O 0x%x offset 0x%x", port
->iobase
, port
->hub6
);
2127 snprintf(address
, sizeof(address
),
2128 "MMIO 0x%llx", (unsigned long long)port
->mapbase
);
2131 strlcpy(address
, "*unknown*", sizeof(address
));
2135 printk(KERN_INFO
"%s%s%s%d at %s (irq = %d) is a %s\n",
2136 port
->dev
? port
->dev
->bus_id
: "",
2137 port
->dev
? ": " : "",
2138 drv
->dev_name
, port
->line
, address
, port
->irq
, uart_type(port
));
2142 uart_configure_port(struct uart_driver
*drv
, struct uart_state
*state
,
2143 struct uart_port
*port
)
2148 * If there isn't a port here, don't do anything further.
2150 if (!port
->iobase
&& !port
->mapbase
&& !port
->membase
)
2154 * Now do the auto configuration stuff. Note that config_port
2155 * is expected to claim the resources and map the port for us.
2157 flags
= UART_CONFIG_TYPE
;
2158 if (port
->flags
& UPF_AUTO_IRQ
)
2159 flags
|= UART_CONFIG_IRQ
;
2160 if (port
->flags
& UPF_BOOT_AUTOCONF
) {
2161 port
->type
= PORT_UNKNOWN
;
2162 port
->ops
->config_port(port
, flags
);
2165 if (port
->type
!= PORT_UNKNOWN
) {
2166 unsigned long flags
;
2168 uart_report_port(drv
, port
);
2170 /* Power up port for set_mctrl() */
2171 uart_change_pm(state
, 0);
2174 * Ensure that the modem control lines are de-activated.
2175 * keep the DTR setting that is set in uart_set_options()
2176 * We probably don't need a spinlock around this, but
2178 spin_lock_irqsave(&port
->lock
, flags
);
2179 port
->ops
->set_mctrl(port
, port
->mctrl
& TIOCM_DTR
);
2180 spin_unlock_irqrestore(&port
->lock
, flags
);
2183 * If this driver supports console, and it hasn't been
2184 * successfully registered yet, try to re-register it.
2185 * It may be that the port was not available.
2187 if (port
->cons
&& !(port
->cons
->flags
& CON_ENABLED
))
2188 register_console(port
->cons
);
2191 * Power down all ports by default, except the
2192 * console if we have one.
2194 if (!uart_console(port
))
2195 uart_change_pm(state
, 3);
2199 #ifdef CONFIG_CONSOLE_POLL
2201 static int uart_poll_init(struct tty_driver
*driver
, int line
, char *options
)
2203 struct uart_driver
*drv
= driver
->driver_state
;
2204 struct uart_state
*state
= drv
->state
+ line
;
2205 struct uart_port
*port
;
2211 if (!state
|| !state
->port
)
2215 if (!(port
->ops
->poll_get_char
&& port
->ops
->poll_put_char
))
2219 uart_parse_options(options
, &baud
, &parity
, &bits
, &flow
);
2220 return uart_set_options(port
, NULL
, baud
, parity
, bits
, flow
);
2226 static int uart_poll_get_char(struct tty_driver
*driver
, int line
)
2228 struct uart_driver
*drv
= driver
->driver_state
;
2229 struct uart_state
*state
= drv
->state
+ line
;
2230 struct uart_port
*port
;
2232 if (!state
|| !state
->port
)
2236 return port
->ops
->poll_get_char(port
);
2239 static void uart_poll_put_char(struct tty_driver
*driver
, int line
, char ch
)
2241 struct uart_driver
*drv
= driver
->driver_state
;
2242 struct uart_state
*state
= drv
->state
+ line
;
2243 struct uart_port
*port
;
2245 if (!state
|| !state
->port
)
2249 port
->ops
->poll_put_char(port
, ch
);
2253 static const struct tty_operations uart_ops
= {
2255 .close
= uart_close
,
2256 .write
= uart_write
,
2257 .put_char
= uart_put_char
,
2258 .flush_chars
= uart_flush_chars
,
2259 .write_room
= uart_write_room
,
2260 .chars_in_buffer
= uart_chars_in_buffer
,
2261 .flush_buffer
= uart_flush_buffer
,
2262 .ioctl
= uart_ioctl
,
2263 .throttle
= uart_throttle
,
2264 .unthrottle
= uart_unthrottle
,
2265 .send_xchar
= uart_send_xchar
,
2266 .set_termios
= uart_set_termios
,
2268 .start
= uart_start
,
2269 .hangup
= uart_hangup
,
2270 .break_ctl
= uart_break_ctl
,
2271 .wait_until_sent
= uart_wait_until_sent
,
2272 #ifdef CONFIG_PROC_FS
2273 .read_proc
= uart_read_proc
,
2275 .tiocmget
= uart_tiocmget
,
2276 .tiocmset
= uart_tiocmset
,
2277 #ifdef CONFIG_CONSOLE_POLL
2278 .poll_init
= uart_poll_init
,
2279 .poll_get_char
= uart_poll_get_char
,
2280 .poll_put_char
= uart_poll_put_char
,
2285 * uart_register_driver - register a driver with the uart core layer
2286 * @drv: low level driver structure
2288 * Register a uart driver with the core driver. We in turn register
2289 * with the tty layer, and initialise the core driver per-port state.
2291 * We have a proc file in /proc/tty/driver which is named after the
2294 * drv->port should be NULL, and the per-port structures should be
2295 * registered using uart_add_one_port after this call has succeeded.
2297 int uart_register_driver(struct uart_driver
*drv
)
2299 struct tty_driver
*normal
= NULL
;
2305 * Maybe we should be using a slab cache for this, especially if
2306 * we have a large number of ports to handle.
2308 drv
->state
= kzalloc(sizeof(struct uart_state
) * drv
->nr
, GFP_KERNEL
);
2313 normal
= alloc_tty_driver(drv
->nr
);
2317 drv
->tty_driver
= normal
;
2319 normal
->owner
= drv
->owner
;
2320 normal
->driver_name
= drv
->driver_name
;
2321 normal
->name
= drv
->dev_name
;
2322 normal
->major
= drv
->major
;
2323 normal
->minor_start
= drv
->minor
;
2324 normal
->type
= TTY_DRIVER_TYPE_SERIAL
;
2325 normal
->subtype
= SERIAL_TYPE_NORMAL
;
2326 normal
->init_termios
= tty_std_termios
;
2327 normal
->init_termios
.c_cflag
= B9600
| CS8
| CREAD
| HUPCL
| CLOCAL
;
2328 normal
->init_termios
.c_ispeed
= normal
->init_termios
.c_ospeed
= 9600;
2329 normal
->flags
= TTY_DRIVER_REAL_RAW
| TTY_DRIVER_DYNAMIC_DEV
;
2330 normal
->driver_state
= drv
;
2331 tty_set_operations(normal
, &uart_ops
);
2334 * Initialise the UART state(s).
2336 for (i
= 0; i
< drv
->nr
; i
++) {
2337 struct uart_state
*state
= drv
->state
+ i
;
2339 state
->close_delay
= 500; /* .5 seconds */
2340 state
->closing_wait
= 30000; /* 30 seconds */
2342 mutex_init(&state
->mutex
);
2345 retval
= tty_register_driver(normal
);
2348 put_tty_driver(normal
);
2355 * uart_unregister_driver - remove a driver from the uart core layer
2356 * @drv: low level driver structure
2358 * Remove all references to a driver from the core driver. The low
2359 * level driver must have removed all its ports via the
2360 * uart_remove_one_port() if it registered them with uart_add_one_port().
2361 * (ie, drv->port == NULL)
2363 void uart_unregister_driver(struct uart_driver
*drv
)
2365 struct tty_driver
*p
= drv
->tty_driver
;
2366 tty_unregister_driver(p
);
2369 drv
->tty_driver
= NULL
;
2372 struct tty_driver
*uart_console_device(struct console
*co
, int *index
)
2374 struct uart_driver
*p
= co
->data
;
2376 return p
->tty_driver
;
2380 * uart_add_one_port - attach a driver-defined port structure
2381 * @drv: pointer to the uart low level driver structure for this port
2382 * @port: uart port structure to use for this port.
2384 * This allows the driver to register its own uart_port structure
2385 * with the core driver. The main purpose is to allow the low
2386 * level uart drivers to expand uart_port, rather than having yet
2387 * more levels of structures.
2389 int uart_add_one_port(struct uart_driver
*drv
, struct uart_port
*port
)
2391 struct uart_state
*state
;
2393 struct device
*tty_dev
;
2395 BUG_ON(in_interrupt());
2397 if (port
->line
>= drv
->nr
)
2400 state
= drv
->state
+ port
->line
;
2402 mutex_lock(&port_mutex
);
2403 mutex_lock(&state
->mutex
);
2410 state
->pm_state
= -1;
2412 port
->cons
= drv
->cons
;
2413 port
->info
= state
->info
;
2416 * If this port is a console, then the spinlock is already
2419 if (!(uart_console(port
) && (port
->cons
->flags
& CON_ENABLED
))) {
2420 spin_lock_init(&port
->lock
);
2421 lockdep_set_class(&port
->lock
, &port_lock_key
);
2424 uart_configure_port(drv
, state
, port
);
2427 * Register the port whether it's detected or not. This allows
2428 * setserial to be used to alter this ports parameters.
2430 tty_dev
= tty_register_device(drv
->tty_driver
, port
->line
, port
->dev
);
2431 if (likely(!IS_ERR(tty_dev
))) {
2432 device_init_wakeup(tty_dev
, 1);
2433 device_set_wakeup_enable(tty_dev
, 0);
2435 printk(KERN_ERR
"Cannot register tty device on line %d\n",
2439 * Ensure UPF_DEAD is not set.
2441 port
->flags
&= ~UPF_DEAD
;
2444 mutex_unlock(&state
->mutex
);
2445 mutex_unlock(&port_mutex
);
2451 * uart_remove_one_port - detach a driver defined port structure
2452 * @drv: pointer to the uart low level driver structure for this port
2453 * @port: uart port structure for this port
2455 * This unhooks (and hangs up) the specified port structure from the
2456 * core driver. No further calls will be made to the low-level code
2459 int uart_remove_one_port(struct uart_driver
*drv
, struct uart_port
*port
)
2461 struct uart_state
*state
= drv
->state
+ port
->line
;
2462 struct uart_info
*info
;
2464 BUG_ON(in_interrupt());
2466 if (state
->port
!= port
)
2467 printk(KERN_ALERT
"Removing wrong port: %p != %p\n",
2470 mutex_lock(&port_mutex
);
2473 * Mark the port "dead" - this prevents any opens from
2474 * succeeding while we shut down the port.
2476 mutex_lock(&state
->mutex
);
2477 port
->flags
|= UPF_DEAD
;
2478 mutex_unlock(&state
->mutex
);
2481 * Remove the devices from the tty layer
2483 tty_unregister_device(drv
->tty_driver
, port
->line
);
2486 if (info
&& info
->tty
)
2487 tty_vhangup(info
->tty
);
2490 * All users of this port should now be disconnected from
2491 * this driver, and the port shut down. We should be the
2492 * only thread fiddling with this port from now on.
2497 * Free the port IO and memory resources, if any.
2499 if (port
->type
!= PORT_UNKNOWN
)
2500 port
->ops
->release_port(port
);
2503 * Indicate that there isn't a port here anymore.
2505 port
->type
= PORT_UNKNOWN
;
2508 * Kill the tasklet, and free resources.
2511 tasklet_kill(&info
->tlet
);
2516 mutex_unlock(&port_mutex
);
2522 * Are the two ports equivalent?
2524 int uart_match_port(struct uart_port
*port1
, struct uart_port
*port2
)
2526 if (port1
->iotype
!= port2
->iotype
)
2529 switch (port1
->iotype
) {
2531 return (port1
->iobase
== port2
->iobase
);
2533 return (port1
->iobase
== port2
->iobase
) &&
2534 (port1
->hub6
== port2
->hub6
);
2540 return (port1
->mapbase
== port2
->mapbase
);
2544 EXPORT_SYMBOL(uart_match_port
);
2546 EXPORT_SYMBOL(uart_write_wakeup
);
2547 EXPORT_SYMBOL(uart_register_driver
);
2548 EXPORT_SYMBOL(uart_unregister_driver
);
2549 EXPORT_SYMBOL(uart_suspend_port
);
2550 EXPORT_SYMBOL(uart_resume_port
);
2551 EXPORT_SYMBOL(uart_add_one_port
);
2552 EXPORT_SYMBOL(uart_remove_one_port
);
2554 MODULE_DESCRIPTION("Serial driver core");
2555 MODULE_LICENSE("GPL");