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/proc_fs.h>
31 #include <linux/seq_file.h>
32 #include <linux/smp_lock.h>
33 #include <linux/device.h>
34 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
35 #include <linux/serial_core.h>
36 #include <linux/delay.h>
37 #include <linux/mutex.h>
40 #include <asm/uaccess.h>
43 * This is used to lock changes in serial line configuration.
45 static DEFINE_MUTEX(port_mutex
);
48 * lockdep: port->lock is initialized in two places, but we
49 * want only one lock-class:
51 static struct lock_class_key port_lock_key
;
53 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
55 #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 tty_struct
*tty
, 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_state
*state
= port
->state
;
74 * This means you called this function _after_ the port was
75 * closed. No cookie for you.
78 tasklet_schedule(&state
->tlet
);
81 static void uart_stop(struct tty_struct
*tty
)
83 struct uart_state
*state
= tty
->driver_data
;
84 struct uart_port
*port
= state
->uart_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
->uart_port
;
97 if (!uart_circ_empty(&state
->xmit
) && state
->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
->uart_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
->port
.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 mutex.
140 static int uart_startup(struct tty_struct
*tty
, struct uart_state
*state
, int init_hw
)
142 struct uart_port
*uport
= state
->uart_port
;
143 struct tty_port
*port
= &state
->port
;
147 if (port
->flags
& ASYNC_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
, &tty
->flags
);
157 if (uport
->type
== PORT_UNKNOWN
)
161 * Initialise and allocate the transmit and temporary
164 if (!state
->xmit
.buf
) {
165 /* This is protected by the per port mutex */
166 page
= get_zeroed_page(GFP_KERNEL
);
170 state
->xmit
.buf
= (unsigned char *) page
;
171 uart_circ_clear(&state
->xmit
);
174 retval
= uport
->ops
->startup(uport
);
178 * Initialise the hardware port settings.
180 uart_change_speed(tty
, state
, NULL
);
183 * Setup the RTS and DTR signals once the
184 * port is open and ready to respond.
186 if (tty
->termios
->c_cflag
& CBAUD
)
187 uart_set_mctrl(uport
, TIOCM_RTS
| TIOCM_DTR
);
190 if (port
->flags
& ASYNC_CTS_FLOW
) {
191 spin_lock_irq(&uport
->lock
);
192 if (!(uport
->ops
->get_mctrl(uport
) & TIOCM_CTS
))
194 spin_unlock_irq(&uport
->lock
);
197 set_bit(ASYNCB_INITIALIZED
, &port
->flags
);
199 clear_bit(TTY_IO_ERROR
, &tty
->flags
);
202 if (retval
&& capable(CAP_SYS_ADMIN
))
209 * This routine will shutdown a serial port; interrupts are disabled, and
210 * DTR is dropped if the hangup on close termio flag is on. Calls to
211 * uart_shutdown are serialised by the per-port semaphore.
213 static void uart_shutdown(struct tty_struct
*tty
, struct uart_state
*state
)
215 struct uart_port
*uport
= state
->uart_port
;
216 struct tty_port
*port
= &state
->port
;
219 * Set the TTY IO error marker
222 set_bit(TTY_IO_ERROR
, &tty
->flags
);
224 if (test_and_clear_bit(ASYNCB_INITIALIZED
, &port
->flags
)) {
226 * Turn off DTR and RTS early.
228 if (!tty
|| (tty
->termios
->c_cflag
& HUPCL
))
229 uart_clear_mctrl(uport
, TIOCM_DTR
| TIOCM_RTS
);
232 * clear delta_msr_wait queue to avoid mem leaks: we may free
233 * the irq here so the queue might never be woken up. Note
234 * that we won't end up waiting on delta_msr_wait again since
235 * any outstanding file descriptors should be pointing at
236 * hung_up_tty_fops now.
238 wake_up_interruptible(&port
->delta_msr_wait
);
241 * Free the IRQ and disable the port.
243 uport
->ops
->shutdown(uport
);
246 * Ensure that the IRQ handler isn't running on another CPU.
248 synchronize_irq(uport
->irq
);
252 * kill off our tasklet
254 tasklet_kill(&state
->tlet
);
257 * Free the transmit buffer page.
259 if (state
->xmit
.buf
) {
260 free_page((unsigned long)state
->xmit
.buf
);
261 state
->xmit
.buf
= NULL
;
266 * uart_update_timeout - update per-port FIFO timeout.
267 * @port: uart_port structure describing the port
268 * @cflag: termios cflag value
269 * @baud: speed of the port
271 * Set the port FIFO timeout value. The @cflag value should
272 * reflect the actual hardware settings.
275 uart_update_timeout(struct uart_port
*port
, unsigned int cflag
,
280 /* byte size and parity */
281 switch (cflag
& CSIZE
) {
302 * The total number of bits to be transmitted in the fifo.
304 bits
= bits
* port
->fifosize
;
307 * Figure the timeout to send the above number of bits.
308 * Add .02 seconds of slop
310 port
->timeout
= (HZ
* bits
) / baud
+ HZ
/50;
313 EXPORT_SYMBOL(uart_update_timeout
);
316 * uart_get_baud_rate - return baud rate for a particular port
317 * @port: uart_port structure describing the port in question.
318 * @termios: desired termios settings.
319 * @old: old termios (or NULL)
320 * @min: minimum acceptable baud rate
321 * @max: maximum acceptable baud rate
323 * Decode the termios structure into a numeric baud rate,
324 * taking account of the magic 38400 baud rate (with spd_*
325 * flags), and mapping the %B0 rate to 9600 baud.
327 * If the new baud rate is invalid, try the old termios setting.
328 * If it's still invalid, we try 9600 baud.
330 * Update the @termios structure to reflect the baud rate
331 * we're actually going to be using. Don't do this for the case
332 * where B0 is requested ("hang up").
335 uart_get_baud_rate(struct uart_port
*port
, struct ktermios
*termios
,
336 struct ktermios
*old
, unsigned int min
, unsigned int max
)
338 unsigned int try, baud
, altbaud
= 38400;
340 upf_t flags
= port
->flags
& UPF_SPD_MASK
;
342 if (flags
== UPF_SPD_HI
)
344 else if (flags
== UPF_SPD_VHI
)
346 else if (flags
== UPF_SPD_SHI
)
348 else if (flags
== UPF_SPD_WARP
)
351 for (try = 0; try < 2; try++) {
352 baud
= tty_termios_baud_rate(termios
);
355 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
362 * Special case: B0 rate.
369 if (baud
>= min
&& baud
<= max
)
373 * Oops, the quotient was zero. Try again with
374 * the old baud rate if possible.
376 termios
->c_cflag
&= ~CBAUD
;
378 baud
= tty_termios_baud_rate(old
);
380 tty_termios_encode_baud_rate(termios
,
387 * As a last resort, if the range cannot be met then clip to
388 * the nearest chip supported rate.
392 tty_termios_encode_baud_rate(termios
,
395 tty_termios_encode_baud_rate(termios
,
399 /* Should never happen */
404 EXPORT_SYMBOL(uart_get_baud_rate
);
407 * uart_get_divisor - return uart clock divisor
408 * @port: uart_port structure describing the port.
409 * @baud: desired baud rate
411 * Calculate the uart clock divisor for the port.
414 uart_get_divisor(struct uart_port
*port
, unsigned int baud
)
419 * Old custom speed handling.
421 if (baud
== 38400 && (port
->flags
& UPF_SPD_MASK
) == UPF_SPD_CUST
)
422 quot
= port
->custom_divisor
;
424 quot
= (port
->uartclk
+ (8 * baud
)) / (16 * baud
);
429 EXPORT_SYMBOL(uart_get_divisor
);
431 /* FIXME: Consistent locking policy */
432 static void uart_change_speed(struct tty_struct
*tty
, struct uart_state
*state
,
433 struct ktermios
*old_termios
)
435 struct tty_port
*port
= &state
->port
;
436 struct uart_port
*uport
= state
->uart_port
;
437 struct ktermios
*termios
;
440 * If we have no tty, termios, or the port does not exist,
441 * then we can't set the parameters for this port.
443 if (!tty
|| !tty
->termios
|| uport
->type
== PORT_UNKNOWN
)
446 termios
= tty
->termios
;
449 * Set flags based on termios cflag
451 if (termios
->c_cflag
& CRTSCTS
)
452 set_bit(ASYNCB_CTS_FLOW
, &port
->flags
);
454 clear_bit(ASYNCB_CTS_FLOW
, &port
->flags
);
456 if (termios
->c_cflag
& CLOCAL
)
457 clear_bit(ASYNCB_CHECK_CD
, &port
->flags
);
459 set_bit(ASYNCB_CHECK_CD
, &port
->flags
);
461 uport
->ops
->set_termios(uport
, termios
, old_termios
);
464 static inline int __uart_put_char(struct uart_port
*port
,
465 struct circ_buf
*circ
, unsigned char c
)
473 spin_lock_irqsave(&port
->lock
, flags
);
474 if (uart_circ_chars_free(circ
) != 0) {
475 circ
->buf
[circ
->head
] = c
;
476 circ
->head
= (circ
->head
+ 1) & (UART_XMIT_SIZE
- 1);
479 spin_unlock_irqrestore(&port
->lock
, flags
);
483 static int uart_put_char(struct tty_struct
*tty
, unsigned char ch
)
485 struct uart_state
*state
= tty
->driver_data
;
487 return __uart_put_char(state
->uart_port
, &state
->xmit
, ch
);
490 static void uart_flush_chars(struct tty_struct
*tty
)
495 static int uart_write(struct tty_struct
*tty
,
496 const unsigned char *buf
, int count
)
498 struct uart_state
*state
= tty
->driver_data
;
499 struct uart_port
*port
;
500 struct circ_buf
*circ
;
505 * This means you called this function _after_ the port was
506 * closed. No cookie for you.
513 port
= state
->uart_port
;
519 spin_lock_irqsave(&port
->lock
, flags
);
521 c
= CIRC_SPACE_TO_END(circ
->head
, circ
->tail
, UART_XMIT_SIZE
);
526 memcpy(circ
->buf
+ circ
->head
, buf
, c
);
527 circ
->head
= (circ
->head
+ c
) & (UART_XMIT_SIZE
- 1);
532 spin_unlock_irqrestore(&port
->lock
, flags
);
538 static int uart_write_room(struct tty_struct
*tty
)
540 struct uart_state
*state
= tty
->driver_data
;
544 spin_lock_irqsave(&state
->uart_port
->lock
, flags
);
545 ret
= uart_circ_chars_free(&state
->xmit
);
546 spin_unlock_irqrestore(&state
->uart_port
->lock
, flags
);
550 static int uart_chars_in_buffer(struct tty_struct
*tty
)
552 struct uart_state
*state
= tty
->driver_data
;
556 spin_lock_irqsave(&state
->uart_port
->lock
, flags
);
557 ret
= uart_circ_chars_pending(&state
->xmit
);
558 spin_unlock_irqrestore(&state
->uart_port
->lock
, flags
);
562 static void uart_flush_buffer(struct tty_struct
*tty
)
564 struct uart_state
*state
= tty
->driver_data
;
565 struct uart_port
*port
;
569 * This means you called this function _after_ the port was
570 * closed. No cookie for you.
577 port
= state
->uart_port
;
578 pr_debug("uart_flush_buffer(%d) called\n", tty
->index
);
580 spin_lock_irqsave(&port
->lock
, flags
);
581 uart_circ_clear(&state
->xmit
);
582 if (port
->ops
->flush_buffer
)
583 port
->ops
->flush_buffer(port
);
584 spin_unlock_irqrestore(&port
->lock
, flags
);
589 * This function is used to send a high-priority XON/XOFF character to
592 static void uart_send_xchar(struct tty_struct
*tty
, char ch
)
594 struct uart_state
*state
= tty
->driver_data
;
595 struct uart_port
*port
= state
->uart_port
;
598 if (port
->ops
->send_xchar
)
599 port
->ops
->send_xchar(port
, ch
);
603 spin_lock_irqsave(&port
->lock
, flags
);
604 port
->ops
->start_tx(port
);
605 spin_unlock_irqrestore(&port
->lock
, flags
);
610 static void uart_throttle(struct tty_struct
*tty
)
612 struct uart_state
*state
= tty
->driver_data
;
615 uart_send_xchar(tty
, STOP_CHAR(tty
));
617 if (tty
->termios
->c_cflag
& CRTSCTS
)
618 uart_clear_mctrl(state
->uart_port
, TIOCM_RTS
);
621 static void uart_unthrottle(struct tty_struct
*tty
)
623 struct uart_state
*state
= tty
->driver_data
;
624 struct uart_port
*port
= state
->uart_port
;
630 uart_send_xchar(tty
, START_CHAR(tty
));
633 if (tty
->termios
->c_cflag
& CRTSCTS
)
634 uart_set_mctrl(port
, TIOCM_RTS
);
637 static int uart_get_info(struct uart_state
*state
,
638 struct serial_struct __user
*retinfo
)
640 struct uart_port
*uport
= state
->uart_port
;
641 struct tty_port
*port
= &state
->port
;
642 struct serial_struct tmp
;
644 memset(&tmp
, 0, sizeof(tmp
));
646 /* Ensure the state we copy is consistent and no hardware changes
648 mutex_lock(&port
->mutex
);
650 tmp
.type
= uport
->type
;
651 tmp
.line
= uport
->line
;
652 tmp
.port
= uport
->iobase
;
653 if (HIGH_BITS_OFFSET
)
654 tmp
.port_high
= (long) uport
->iobase
>> HIGH_BITS_OFFSET
;
655 tmp
.irq
= uport
->irq
;
656 tmp
.flags
= uport
->flags
;
657 tmp
.xmit_fifo_size
= uport
->fifosize
;
658 tmp
.baud_base
= uport
->uartclk
/ 16;
659 tmp
.close_delay
= port
->close_delay
/ 10;
660 tmp
.closing_wait
= port
->closing_wait
== ASYNC_CLOSING_WAIT_NONE
?
661 ASYNC_CLOSING_WAIT_NONE
:
662 port
->closing_wait
/ 10;
663 tmp
.custom_divisor
= uport
->custom_divisor
;
664 tmp
.hub6
= uport
->hub6
;
665 tmp
.io_type
= uport
->iotype
;
666 tmp
.iomem_reg_shift
= uport
->regshift
;
667 tmp
.iomem_base
= (void *)(unsigned long)uport
->mapbase
;
669 mutex_unlock(&port
->mutex
);
671 if (copy_to_user(retinfo
, &tmp
, sizeof(*retinfo
)))
676 static int uart_set_info(struct tty_struct
*tty
, struct uart_state
*state
,
677 struct serial_struct __user
*newinfo
)
679 struct serial_struct new_serial
;
680 struct uart_port
*uport
= state
->uart_port
;
681 struct tty_port
*port
= &state
->port
;
682 unsigned long new_port
;
683 unsigned int change_irq
, change_port
, closing_wait
;
684 unsigned int old_custom_divisor
, close_delay
;
685 upf_t old_flags
, new_flags
;
688 if (copy_from_user(&new_serial
, newinfo
, sizeof(new_serial
)))
691 new_port
= new_serial
.port
;
692 if (HIGH_BITS_OFFSET
)
693 new_port
+= (unsigned long) new_serial
.port_high
<< HIGH_BITS_OFFSET
;
695 new_serial
.irq
= irq_canonicalize(new_serial
.irq
);
696 close_delay
= new_serial
.close_delay
* 10;
697 closing_wait
= new_serial
.closing_wait
== ASYNC_CLOSING_WAIT_NONE
?
698 ASYNC_CLOSING_WAIT_NONE
: new_serial
.closing_wait
* 10;
701 * This semaphore protects port->count. It is also
702 * very useful to prevent opens. Also, take the
703 * port configuration semaphore to make sure that a
704 * module insertion/removal doesn't change anything
707 mutex_lock(&port
->mutex
);
709 change_irq
= !(uport
->flags
& UPF_FIXED_PORT
)
710 && new_serial
.irq
!= uport
->irq
;
713 * Since changing the 'type' of the port changes its resource
714 * allocations, we should treat type changes the same as
717 change_port
= !(uport
->flags
& UPF_FIXED_PORT
)
718 && (new_port
!= uport
->iobase
||
719 (unsigned long)new_serial
.iomem_base
!= uport
->mapbase
||
720 new_serial
.hub6
!= uport
->hub6
||
721 new_serial
.io_type
!= uport
->iotype
||
722 new_serial
.iomem_reg_shift
!= uport
->regshift
||
723 new_serial
.type
!= uport
->type
);
725 old_flags
= uport
->flags
;
726 new_flags
= new_serial
.flags
;
727 old_custom_divisor
= uport
->custom_divisor
;
729 if (!capable(CAP_SYS_ADMIN
)) {
731 if (change_irq
|| change_port
||
732 (new_serial
.baud_base
!= uport
->uartclk
/ 16) ||
733 (close_delay
!= port
->close_delay
) ||
734 (closing_wait
!= port
->closing_wait
) ||
735 (new_serial
.xmit_fifo_size
&&
736 new_serial
.xmit_fifo_size
!= uport
->fifosize
) ||
737 (((new_flags
^ old_flags
) & ~UPF_USR_MASK
) != 0))
739 uport
->flags
= ((uport
->flags
& ~UPF_USR_MASK
) |
740 (new_flags
& UPF_USR_MASK
));
741 uport
->custom_divisor
= new_serial
.custom_divisor
;
746 * Ask the low level driver to verify the settings.
748 if (uport
->ops
->verify_port
)
749 retval
= uport
->ops
->verify_port(uport
, &new_serial
);
751 if ((new_serial
.irq
>= nr_irqs
) || (new_serial
.irq
< 0) ||
752 (new_serial
.baud_base
< 9600))
758 if (change_port
|| change_irq
) {
762 * Make sure that we are the sole user of this port.
764 if (tty_port_users(port
) > 1)
768 * We need to shutdown the serial port at the old
769 * port/type/irq combination.
771 uart_shutdown(tty
, state
);
775 unsigned long old_iobase
, old_mapbase
;
776 unsigned int old_type
, old_iotype
, old_hub6
, old_shift
;
778 old_iobase
= uport
->iobase
;
779 old_mapbase
= uport
->mapbase
;
780 old_type
= uport
->type
;
781 old_hub6
= uport
->hub6
;
782 old_iotype
= uport
->iotype
;
783 old_shift
= uport
->regshift
;
786 * Free and release old regions
788 if (old_type
!= PORT_UNKNOWN
)
789 uport
->ops
->release_port(uport
);
791 uport
->iobase
= new_port
;
792 uport
->type
= new_serial
.type
;
793 uport
->hub6
= new_serial
.hub6
;
794 uport
->iotype
= new_serial
.io_type
;
795 uport
->regshift
= new_serial
.iomem_reg_shift
;
796 uport
->mapbase
= (unsigned long)new_serial
.iomem_base
;
799 * Claim and map the new regions
801 if (uport
->type
!= PORT_UNKNOWN
) {
802 retval
= uport
->ops
->request_port(uport
);
804 /* Always success - Jean II */
809 * If we fail to request resources for the
810 * new port, try to restore the old settings.
812 if (retval
&& old_type
!= PORT_UNKNOWN
) {
813 uport
->iobase
= old_iobase
;
814 uport
->type
= old_type
;
815 uport
->hub6
= old_hub6
;
816 uport
->iotype
= old_iotype
;
817 uport
->regshift
= old_shift
;
818 uport
->mapbase
= old_mapbase
;
819 retval
= uport
->ops
->request_port(uport
);
821 * If we failed to restore the old settings,
825 uport
->type
= PORT_UNKNOWN
;
831 /* Added to return the correct error -Ram Gupta */
837 uport
->irq
= new_serial
.irq
;
838 if (!(uport
->flags
& UPF_FIXED_PORT
))
839 uport
->uartclk
= new_serial
.baud_base
* 16;
840 uport
->flags
= (uport
->flags
& ~UPF_CHANGE_MASK
) |
841 (new_flags
& UPF_CHANGE_MASK
);
842 uport
->custom_divisor
= new_serial
.custom_divisor
;
843 port
->close_delay
= close_delay
;
844 port
->closing_wait
= closing_wait
;
845 if (new_serial
.xmit_fifo_size
)
846 uport
->fifosize
= new_serial
.xmit_fifo_size
;
848 port
->tty
->low_latency
=
849 (uport
->flags
& UPF_LOW_LATENCY
) ? 1 : 0;
853 if (uport
->type
== PORT_UNKNOWN
)
855 if (port
->flags
& ASYNC_INITIALIZED
) {
856 if (((old_flags
^ uport
->flags
) & UPF_SPD_MASK
) ||
857 old_custom_divisor
!= uport
->custom_divisor
) {
859 * If they're setting up a custom divisor or speed,
860 * instead of clearing it, then bitch about it. No
861 * need to rate-limit; it's CAP_SYS_ADMIN only.
863 if (uport
->flags
& UPF_SPD_MASK
) {
866 "%s sets custom speed on %s. This "
867 "is deprecated.\n", current
->comm
,
868 tty_name(port
->tty
, buf
));
870 uart_change_speed(tty
, state
, NULL
);
873 retval
= uart_startup(tty
, state
, 1);
875 mutex_unlock(&port
->mutex
);
880 * uart_get_lsr_info - get line status register info
881 * @tty: tty associated with the UART
882 * @state: UART being queried
883 * @value: returned modem value
885 * Note: uart_ioctl protects us against hangups.
887 static int uart_get_lsr_info(struct tty_struct
*tty
,
888 struct uart_state
*state
, unsigned int __user
*value
)
890 struct uart_port
*uport
= state
->uart_port
;
893 result
= uport
->ops
->tx_empty(uport
);
896 * If we're about to load something into the transmit
897 * register, we'll pretend the transmitter isn't empty to
898 * avoid a race condition (depending on when the transmit
899 * interrupt happens).
902 ((uart_circ_chars_pending(&state
->xmit
) > 0) &&
903 !tty
->stopped
&& !tty
->hw_stopped
))
904 result
&= ~TIOCSER_TEMT
;
906 return put_user(result
, value
);
909 static int uart_tiocmget(struct tty_struct
*tty
, struct file
*file
)
911 struct uart_state
*state
= tty
->driver_data
;
912 struct tty_port
*port
= &state
->port
;
913 struct uart_port
*uport
= state
->uart_port
;
916 mutex_lock(&port
->mutex
);
917 if ((!file
|| !tty_hung_up_p(file
)) &&
918 !(tty
->flags
& (1 << TTY_IO_ERROR
))) {
919 result
= uport
->mctrl
;
921 spin_lock_irq(&uport
->lock
);
922 result
|= uport
->ops
->get_mctrl(uport
);
923 spin_unlock_irq(&uport
->lock
);
925 mutex_unlock(&port
->mutex
);
931 uart_tiocmset(struct tty_struct
*tty
, struct file
*file
,
932 unsigned int set
, unsigned int clear
)
934 struct uart_state
*state
= tty
->driver_data
;
935 struct uart_port
*uport
= state
->uart_port
;
936 struct tty_port
*port
= &state
->port
;
939 mutex_lock(&port
->mutex
);
940 if ((!file
|| !tty_hung_up_p(file
)) &&
941 !(tty
->flags
& (1 << TTY_IO_ERROR
))) {
942 uart_update_mctrl(uport
, set
, clear
);
945 mutex_unlock(&port
->mutex
);
949 static int uart_break_ctl(struct tty_struct
*tty
, int break_state
)
951 struct uart_state
*state
= tty
->driver_data
;
952 struct tty_port
*port
= &state
->port
;
953 struct uart_port
*uport
= state
->uart_port
;
955 mutex_lock(&port
->mutex
);
957 if (uport
->type
!= PORT_UNKNOWN
)
958 uport
->ops
->break_ctl(uport
, break_state
);
960 mutex_unlock(&port
->mutex
);
964 static int uart_do_autoconfig(struct tty_struct
*tty
,struct uart_state
*state
)
966 struct uart_port
*uport
= state
->uart_port
;
967 struct tty_port
*port
= &state
->port
;
970 if (!capable(CAP_SYS_ADMIN
))
974 * Take the per-port semaphore. This prevents count from
975 * changing, and hence any extra opens of the port while
976 * we're auto-configuring.
978 if (mutex_lock_interruptible(&port
->mutex
))
982 if (tty_port_users(port
) == 1) {
983 uart_shutdown(tty
, state
);
986 * If we already have a port type configured,
987 * we must release its resources.
989 if (uport
->type
!= PORT_UNKNOWN
)
990 uport
->ops
->release_port(uport
);
992 flags
= UART_CONFIG_TYPE
;
993 if (uport
->flags
& UPF_AUTO_IRQ
)
994 flags
|= UART_CONFIG_IRQ
;
997 * This will claim the ports resources if
1000 uport
->ops
->config_port(uport
, flags
);
1002 ret
= uart_startup(tty
, state
, 1);
1004 mutex_unlock(&port
->mutex
);
1009 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1010 * - mask passed in arg for lines of interest
1011 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1012 * Caller should use TIOCGICOUNT to see which one it was
1014 * FIXME: This wants extracting into a common all driver implementation
1015 * of TIOCMWAIT using tty_port.
1018 uart_wait_modem_status(struct uart_state
*state
, unsigned long arg
)
1020 struct uart_port
*uport
= state
->uart_port
;
1021 struct tty_port
*port
= &state
->port
;
1022 DECLARE_WAITQUEUE(wait
, current
);
1023 struct uart_icount cprev
, cnow
;
1027 * note the counters on entry
1029 spin_lock_irq(&uport
->lock
);
1030 memcpy(&cprev
, &uport
->icount
, sizeof(struct uart_icount
));
1033 * Force modem status interrupts on
1035 uport
->ops
->enable_ms(uport
);
1036 spin_unlock_irq(&uport
->lock
);
1038 add_wait_queue(&port
->delta_msr_wait
, &wait
);
1040 spin_lock_irq(&uport
->lock
);
1041 memcpy(&cnow
, &uport
->icount
, sizeof(struct uart_icount
));
1042 spin_unlock_irq(&uport
->lock
);
1044 set_current_state(TASK_INTERRUPTIBLE
);
1046 if (((arg
& TIOCM_RNG
) && (cnow
.rng
!= cprev
.rng
)) ||
1047 ((arg
& TIOCM_DSR
) && (cnow
.dsr
!= cprev
.dsr
)) ||
1048 ((arg
& TIOCM_CD
) && (cnow
.dcd
!= cprev
.dcd
)) ||
1049 ((arg
& TIOCM_CTS
) && (cnow
.cts
!= cprev
.cts
))) {
1056 /* see if a signal did it */
1057 if (signal_pending(current
)) {
1065 current
->state
= TASK_RUNNING
;
1066 remove_wait_queue(&port
->delta_msr_wait
, &wait
);
1072 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1073 * Return: write counters to the user passed counter struct
1074 * NB: both 1->0 and 0->1 transitions are counted except for
1075 * RI where only 0->1 is counted.
1077 static int uart_get_count(struct uart_state
*state
,
1078 struct serial_icounter_struct __user
*icnt
)
1080 struct serial_icounter_struct icount
;
1081 struct uart_icount cnow
;
1082 struct uart_port
*uport
= state
->uart_port
;
1084 spin_lock_irq(&uport
->lock
);
1085 memcpy(&cnow
, &uport
->icount
, sizeof(struct uart_icount
));
1086 spin_unlock_irq(&uport
->lock
);
1088 icount
.cts
= cnow
.cts
;
1089 icount
.dsr
= cnow
.dsr
;
1090 icount
.rng
= cnow
.rng
;
1091 icount
.dcd
= cnow
.dcd
;
1092 icount
.rx
= cnow
.rx
;
1093 icount
.tx
= cnow
.tx
;
1094 icount
.frame
= cnow
.frame
;
1095 icount
.overrun
= cnow
.overrun
;
1096 icount
.parity
= cnow
.parity
;
1097 icount
.brk
= cnow
.brk
;
1098 icount
.buf_overrun
= cnow
.buf_overrun
;
1100 return copy_to_user(icnt
, &icount
, sizeof(icount
)) ? -EFAULT
: 0;
1104 * Called via sys_ioctl. We can use spin_lock_irq() here.
1107 uart_ioctl(struct tty_struct
*tty
, struct file
*filp
, unsigned int cmd
,
1110 struct uart_state
*state
= tty
->driver_data
;
1111 struct tty_port
*port
= &state
->port
;
1112 void __user
*uarg
= (void __user
*)arg
;
1113 int ret
= -ENOIOCTLCMD
;
1117 * These ioctls don't rely on the hardware to be present.
1121 ret
= uart_get_info(state
, uarg
);
1125 ret
= uart_set_info(tty
, state
, uarg
);
1129 ret
= uart_do_autoconfig(tty
, state
);
1132 case TIOCSERGWILD
: /* obsolete */
1133 case TIOCSERSWILD
: /* obsolete */
1138 if (ret
!= -ENOIOCTLCMD
)
1141 if (tty
->flags
& (1 << TTY_IO_ERROR
)) {
1147 * The following should only be used when hardware is present.
1151 ret
= uart_wait_modem_status(state
, arg
);
1155 ret
= uart_get_count(state
, uarg
);
1159 if (ret
!= -ENOIOCTLCMD
)
1162 mutex_lock(&port
->mutex
);
1164 if (tty_hung_up_p(filp
)) {
1170 * All these rely on hardware being present and need to be
1171 * protected against the tty being hung up.
1174 case TIOCSERGETLSR
: /* Get line status register */
1175 ret
= uart_get_lsr_info(tty
, state
, uarg
);
1179 struct uart_port
*uport
= state
->uart_port
;
1180 if (uport
->ops
->ioctl
)
1181 ret
= uport
->ops
->ioctl(uport
, cmd
, arg
);
1186 mutex_unlock(&port
->mutex
);
1191 static void uart_set_ldisc(struct tty_struct
*tty
)
1193 struct uart_state
*state
= tty
->driver_data
;
1194 struct uart_port
*uport
= state
->uart_port
;
1196 if (uport
->ops
->set_ldisc
)
1197 uport
->ops
->set_ldisc(uport
, tty
->termios
->c_line
);
1200 static void uart_set_termios(struct tty_struct
*tty
,
1201 struct ktermios
*old_termios
)
1203 struct uart_state
*state
= tty
->driver_data
;
1204 unsigned long flags
;
1205 unsigned int cflag
= tty
->termios
->c_cflag
;
1209 * These are the bits that are used to setup various
1210 * flags in the low level driver. We can ignore the Bfoo
1211 * bits in c_cflag; c_[io]speed will always be set
1212 * appropriately by set_termios() in tty_ioctl.c
1214 #define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1215 if ((cflag
^ old_termios
->c_cflag
) == 0 &&
1216 tty
->termios
->c_ospeed
== old_termios
->c_ospeed
&&
1217 tty
->termios
->c_ispeed
== old_termios
->c_ispeed
&&
1218 RELEVANT_IFLAG(tty
->termios
->c_iflag
^ old_termios
->c_iflag
) == 0) {
1222 uart_change_speed(tty
, state
, old_termios
);
1224 /* Handle transition to B0 status */
1225 if ((old_termios
->c_cflag
& CBAUD
) && !(cflag
& CBAUD
))
1226 uart_clear_mctrl(state
->uart_port
, TIOCM_RTS
| TIOCM_DTR
);
1227 /* Handle transition away from B0 status */
1228 else if (!(old_termios
->c_cflag
& CBAUD
) && (cflag
& CBAUD
)) {
1229 unsigned int mask
= TIOCM_DTR
;
1230 if (!(cflag
& CRTSCTS
) ||
1231 !test_bit(TTY_THROTTLED
, &tty
->flags
))
1233 uart_set_mctrl(state
->uart_port
, mask
);
1236 /* Handle turning off CRTSCTS */
1237 if ((old_termios
->c_cflag
& CRTSCTS
) && !(cflag
& CRTSCTS
)) {
1238 spin_lock_irqsave(&state
->uart_port
->lock
, flags
);
1239 tty
->hw_stopped
= 0;
1241 spin_unlock_irqrestore(&state
->uart_port
->lock
, flags
);
1243 /* Handle turning on CRTSCTS */
1244 else if (!(old_termios
->c_cflag
& CRTSCTS
) && (cflag
& CRTSCTS
)) {
1245 spin_lock_irqsave(&state
->uart_port
->lock
, flags
);
1246 if (!(state
->uart_port
->ops
->get_mctrl(state
->uart_port
) & TIOCM_CTS
)) {
1247 tty
->hw_stopped
= 1;
1248 state
->uart_port
->ops
->stop_tx(state
->uart_port
);
1250 spin_unlock_irqrestore(&state
->uart_port
->lock
, flags
);
1254 * No need to wake up processes in open wait, since they
1255 * sample the CLOCAL flag once, and don't recheck it.
1256 * XXX It's not clear whether the current behavior is correct
1257 * or not. Hence, this may change.....
1259 if (!(old_termios
->c_cflag
& CLOCAL
) &&
1260 (tty
->termios
->c_cflag
& CLOCAL
))
1261 wake_up_interruptible(&state
->uart_port
.open_wait
);
1266 * In 2.4.5, calls to this will be serialized via the BKL in
1267 * linux/drivers/char/tty_io.c:tty_release()
1268 * linux/drivers/char/tty_io.c:do_tty_handup()
1270 static void uart_close(struct tty_struct
*tty
, struct file
*filp
)
1272 struct uart_state
*state
= tty
->driver_data
;
1273 struct tty_port
*port
;
1274 struct uart_port
*uport
;
1275 unsigned long flags
;
1277 BUG_ON(!kernel_locked());
1282 uport
= state
->uart_port
;
1283 port
= &state
->port
;
1285 pr_debug("uart_close(%d) called\n", uport
->line
);
1287 mutex_lock(&port
->mutex
);
1288 spin_lock_irqsave(&port
->lock
, flags
);
1290 if (tty_hung_up_p(filp
)) {
1291 spin_unlock_irqrestore(&port
->lock
, flags
);
1295 if ((tty
->count
== 1) && (port
->count
!= 1)) {
1297 * Uh, oh. tty->count is 1, which means that the tty
1298 * structure will be freed. port->count should always
1299 * be one in these conditions. If it's greater than
1300 * one, we've got real problems, since it means the
1301 * serial port won't be shutdown.
1303 printk(KERN_ERR
"uart_close: bad serial port count; tty->count is 1, "
1304 "port->count is %d\n", port
->count
);
1307 if (--port
->count
< 0) {
1308 printk(KERN_ERR
"uart_close: bad serial port count for %s: %d\n",
1309 tty
->name
, port
->count
);
1313 spin_unlock_irqrestore(&port
->lock
, flags
);
1318 * Now we wait for the transmit buffer to clear; and we notify
1319 * the line discipline to only process XON/XOFF characters by
1320 * setting tty->closing.
1323 spin_unlock_irqrestore(&port
->lock
, flags
);
1325 if (port
->closing_wait
!= ASYNC_CLOSING_WAIT_NONE
)
1326 tty_wait_until_sent(tty
, msecs_to_jiffies(port
->closing_wait
));
1329 * At this point, we stop accepting input. To do this, we
1330 * disable the receive line status interrupts.
1332 if (port
->flags
& ASYNC_INITIALIZED
) {
1333 unsigned long flags
;
1334 spin_lock_irqsave(&uport
->lock
, flags
);
1335 uport
->ops
->stop_rx(uport
);
1336 spin_unlock_irqrestore(&uport
->lock
, flags
);
1338 * Before we drop DTR, make sure the UART transmitter
1339 * has completely drained; this is especially
1340 * important if there is a transmit FIFO!
1342 uart_wait_until_sent(tty
, uport
->timeout
);
1345 uart_shutdown(tty
, state
);
1346 uart_flush_buffer(tty
);
1348 tty_ldisc_flush(tty
);
1350 tty_port_tty_set(port
, NULL
);
1351 spin_lock_irqsave(&port
->lock
, flags
);
1354 if (port
->blocked_open
) {
1355 spin_unlock_irqrestore(&port
->lock
, flags
);
1356 if (port
->close_delay
)
1357 msleep_interruptible(port
->close_delay
);
1358 spin_lock_irqsave(&port
->lock
, flags
);
1359 } else if (!uart_console(uport
)) {
1360 spin_unlock_irqrestore(&port
->lock
, flags
);
1361 uart_change_pm(state
, 3);
1362 spin_lock_irqsave(&port
->lock
, flags
);
1366 * Wake up anyone trying to open this port.
1368 clear_bit(ASYNCB_NORMAL_ACTIVE
, &port
->flags
);
1369 spin_unlock_irqrestore(&port
->lock
, flags
);
1370 wake_up_interruptible(&port
->open_wait
);
1373 mutex_unlock(&port
->mutex
);
1376 static void uart_wait_until_sent(struct tty_struct
*tty
, int timeout
)
1378 struct uart_state
*state
= tty
->driver_data
;
1379 struct uart_port
*port
= state
->uart_port
;
1380 unsigned long char_time
, expire
;
1382 if (port
->type
== PORT_UNKNOWN
|| port
->fifosize
== 0)
1388 * Set the check interval to be 1/5 of the estimated time to
1389 * send a single character, and make it at least 1. The check
1390 * interval should also be less than the timeout.
1392 * Note: we have to use pretty tight timings here to satisfy
1395 char_time
= (port
->timeout
- HZ
/50) / port
->fifosize
;
1396 char_time
= char_time
/ 5;
1399 if (timeout
&& timeout
< char_time
)
1400 char_time
= timeout
;
1403 * If the transmitter hasn't cleared in twice the approximate
1404 * amount of time to send the entire FIFO, it probably won't
1405 * ever clear. This assumes the UART isn't doing flow
1406 * control, which is currently the case. Hence, if it ever
1407 * takes longer than port->timeout, this is probably due to a
1408 * UART bug of some kind. So, we clamp the timeout parameter at
1411 if (timeout
== 0 || timeout
> 2 * port
->timeout
)
1412 timeout
= 2 * port
->timeout
;
1414 expire
= jiffies
+ timeout
;
1416 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1417 port
->line
, jiffies
, expire
);
1420 * Check whether the transmitter is empty every 'char_time'.
1421 * 'timeout' / 'expire' give us the maximum amount of time
1424 while (!port
->ops
->tx_empty(port
)) {
1425 msleep_interruptible(jiffies_to_msecs(char_time
));
1426 if (signal_pending(current
))
1428 if (time_after(jiffies
, expire
))
1431 set_current_state(TASK_RUNNING
); /* might not be needed */
1436 * This is called with the BKL held in
1437 * linux/drivers/char/tty_io.c:do_tty_hangup()
1438 * We're called from the eventd thread, so we can sleep for
1439 * a _short_ time only.
1441 static void uart_hangup(struct tty_struct
*tty
)
1443 struct uart_state
*state
= tty
->driver_data
;
1444 struct tty_port
*port
= &state
->port
;
1445 unsigned long flags
;
1447 BUG_ON(!kernel_locked());
1448 pr_debug("uart_hangup(%d)\n", state
->uart_port
->line
);
1450 mutex_lock(&port
->mutex
);
1451 if (port
->flags
& ASYNC_NORMAL_ACTIVE
) {
1452 uart_flush_buffer(tty
);
1453 uart_shutdown(tty
, state
);
1454 spin_lock_irqsave(&port
->lock
, flags
);
1456 clear_bit(ASYNCB_NORMAL_ACTIVE
, &port
->flags
);
1457 spin_unlock_irqrestore(&port
->lock
, flags
);
1458 tty_port_tty_set(port
, NULL
);
1459 wake_up_interruptible(&port
->open_wait
);
1460 wake_up_interruptible(&port
->delta_msr_wait
);
1462 mutex_unlock(&port
->mutex
);
1466 * uart_update_termios - update the terminal hw settings
1467 * @tty: tty associated with UART
1468 * @state: UART to update
1470 * Copy across the serial console cflag setting into the termios settings
1471 * for the initial open of the port. This allows continuity between the
1472 * kernel settings, and the settings init adopts when it opens the port
1473 * for the first time.
1475 static void uart_update_termios(struct tty_struct
*tty
,
1476 struct uart_state
*state
)
1478 struct uart_port
*port
= state
->uart_port
;
1480 if (uart_console(port
) && port
->cons
->cflag
) {
1481 tty
->termios
->c_cflag
= port
->cons
->cflag
;
1482 port
->cons
->cflag
= 0;
1486 * If the device failed to grab its irq resources,
1487 * or some other error occurred, don't try to talk
1488 * to the port hardware.
1490 if (!(tty
->flags
& (1 << TTY_IO_ERROR
))) {
1492 * Make termios settings take effect.
1494 uart_change_speed(tty
, state
, NULL
);
1497 * And finally enable the RTS and DTR signals.
1499 if (tty
->termios
->c_cflag
& CBAUD
)
1500 uart_set_mctrl(port
, TIOCM_DTR
| TIOCM_RTS
);
1505 * Block the open until the port is ready. We must be called with
1506 * the per-port semaphore held.
1509 uart_block_til_ready(struct file
*filp
, struct uart_state
*state
)
1511 DECLARE_WAITQUEUE(wait
, current
);
1512 struct uart_port
*uport
= state
->uart_port
;
1513 struct tty_port
*port
= &state
->port
;
1515 unsigned long flags
;
1517 spin_lock_irqsave(&port
->lock
, flags
);
1518 if (!tty_hung_up_p(filp
))
1520 port
->blocked_open
++;
1521 spin_unlock_irqrestore(&port
->lock
, flags
);
1523 add_wait_queue(&port
->open_wait
, &wait
);
1525 set_current_state(TASK_INTERRUPTIBLE
);
1528 * If we have been hung up, tell userspace/restart open.
1530 if (tty_hung_up_p(filp
) || port
->tty
== NULL
)
1534 * If the port has been closed, tell userspace/restart open.
1536 if (!(port
->flags
& ASYNC_INITIALIZED
))
1540 * If non-blocking mode is set, or CLOCAL mode is set,
1541 * we don't want to wait for the modem status lines to
1542 * indicate that the port is ready.
1544 * Also, if the port is not enabled/configured, we want
1545 * to allow the open to succeed here. Note that we will
1546 * have set TTY_IO_ERROR for a non-existant port.
1548 if ((filp
->f_flags
& O_NONBLOCK
) ||
1549 (port
->tty
->termios
->c_cflag
& CLOCAL
) ||
1550 (port
->tty
->flags
& (1 << TTY_IO_ERROR
)))
1554 * Set DTR to allow modem to know we're waiting. Do
1555 * not set RTS here - we want to make sure we catch
1556 * the data from the modem.
1558 if (port
->tty
->termios
->c_cflag
& CBAUD
) {
1559 mutex_lock(&port
->mutex
);
1560 uart_set_mctrl(uport
, TIOCM_DTR
);
1561 mutex_unlock(&port
->mutex
);
1565 * and wait for the carrier to indicate that the
1566 * modem is ready for us.
1568 mutex_lock(&port
->mutex
);
1569 spin_lock_irq(&uport
->lock
);
1570 uport
->ops
->enable_ms(uport
);
1571 mctrl
= uport
->ops
->get_mctrl(uport
);
1572 spin_unlock_irq(&uport
->lock
);
1573 mutex_unlock(&port
->mutex
);
1574 if (mctrl
& TIOCM_CAR
)
1579 if (signal_pending(current
))
1582 set_current_state(TASK_RUNNING
);
1583 remove_wait_queue(&port
->open_wait
, &wait
);
1585 spin_lock_irqsave(&port
->lock
, flags
);
1586 if (!tty_hung_up_p(filp
))
1588 port
->blocked_open
--;
1589 spin_unlock_irqrestore(&port
->lock
, flags
);
1591 if (signal_pending(current
))
1592 return -ERESTARTSYS
;
1594 if (!port
->tty
|| tty_hung_up_p(filp
))
1600 static struct uart_state
*uart_get(struct uart_driver
*drv
, int line
)
1602 struct uart_state
*state
;
1603 struct tty_port
*port
;
1606 state
= drv
->state
+ line
;
1607 port
= &state
->port
;
1608 if (mutex_lock_interruptible(&port
->mutex
)) {
1614 if (!state
->uart_port
|| state
->uart_port
->flags
& UPF_DEAD
) {
1622 mutex_unlock(&port
->mutex
);
1624 return ERR_PTR(ret
);
1628 * calls to uart_open are serialised by the BKL in
1629 * fs/char_dev.c:chrdev_open()
1630 * Note that if this fails, then uart_close() _will_ be called.
1632 * In time, we want to scrap the "opening nonpresent ports"
1633 * behaviour and implement an alternative way for setserial
1634 * to set base addresses/ports/types. This will allow us to
1635 * get rid of a certain amount of extra tests.
1637 static int uart_open(struct tty_struct
*tty
, struct file
*filp
)
1639 struct uart_driver
*drv
= (struct uart_driver
*)tty
->driver
->driver_state
;
1640 struct uart_state
*state
;
1641 struct tty_port
*port
;
1642 int retval
, line
= tty
->index
;
1644 BUG_ON(!kernel_locked());
1645 pr_debug("uart_open(%d) called\n", line
);
1648 * tty->driver->num won't change, so we won't fail here with
1649 * tty->driver_data set to something non-NULL (and therefore
1650 * we won't get caught by uart_close()).
1653 if (line
>= tty
->driver
->num
)
1657 * We take the semaphore inside uart_get to guarantee that we won't
1658 * be re-entered while allocating the state structure, or while we
1659 * request any IRQs that the driver may need. This also has the nice
1660 * side-effect that it delays the action of uart_hangup, so we can
1661 * guarantee that state->port.tty will always contain something
1664 state
= uart_get(drv
, line
);
1665 if (IS_ERR(state
)) {
1666 retval
= PTR_ERR(state
);
1669 port
= &state
->port
;
1672 * Once we set tty->driver_data here, we are guaranteed that
1673 * uart_close() will decrement the driver module use count.
1674 * Any failures from here onwards should not touch the count.
1676 tty
->driver_data
= state
;
1677 state
->uart_port
->state
= state
;
1678 tty
->low_latency
= (state
->uart_port
->flags
& UPF_LOW_LATENCY
) ? 1 : 0;
1680 tty_port_tty_set(port
, tty
);
1683 * If the port is in the middle of closing, bail out now.
1685 if (tty_hung_up_p(filp
)) {
1688 mutex_unlock(&port
->mutex
);
1693 * Make sure the device is in D0 state.
1695 if (port
->count
== 1)
1696 uart_change_pm(state
, 0);
1699 * Start up the serial port.
1701 retval
= uart_startup(tty
, state
, 0);
1704 * If we succeeded, wait until the port is ready.
1706 mutex_unlock(&port
->mutex
);
1708 retval
= uart_block_til_ready(filp
, state
);
1711 * If this is the first open to succeed, adjust things to suit.
1713 if (retval
== 0 && !(port
->flags
& ASYNC_NORMAL_ACTIVE
)) {
1714 set_bit(ASYNCB_NORMAL_ACTIVE
, &port
->flags
);
1716 uart_update_termios(tty
, state
);
1723 static const char *uart_type(struct uart_port
*port
)
1725 const char *str
= NULL
;
1727 if (port
->ops
->type
)
1728 str
= port
->ops
->type(port
);
1736 #ifdef CONFIG_PROC_FS
1738 static void uart_line_info(struct seq_file
*m
, struct uart_driver
*drv
, int i
)
1740 struct uart_state
*state
= drv
->state
+ i
;
1741 struct tty_port
*port
= &state
->port
;
1743 struct uart_port
*uport
= state
->uart_port
;
1745 unsigned int status
;
1751 mmio
= uport
->iotype
>= UPIO_MEM
;
1752 seq_printf(m
, "%d: uart:%s %s%08llX irq:%d",
1753 uport
->line
, uart_type(uport
),
1754 mmio
? "mmio:0x" : "port:",
1755 mmio
? (unsigned long long)uport
->mapbase
1756 : (unsigned long long)uport
->iobase
,
1759 if (uport
->type
== PORT_UNKNOWN
) {
1764 if (capable(CAP_SYS_ADMIN
)) {
1765 mutex_lock(&port
->mutex
);
1766 pm_state
= state
->pm_state
;
1768 uart_change_pm(state
, 0);
1769 spin_lock_irq(&uport
->lock
);
1770 status
= uport
->ops
->get_mctrl(uport
);
1771 spin_unlock_irq(&uport
->lock
);
1773 uart_change_pm(state
, pm_state
);
1774 mutex_unlock(&port
->mutex
);
1776 seq_printf(m
, " tx:%d rx:%d",
1777 uport
->icount
.tx
, uport
->icount
.rx
);
1778 if (uport
->icount
.frame
)
1779 seq_printf(m
, " fe:%d",
1780 uport
->icount
.frame
);
1781 if (uport
->icount
.parity
)
1782 seq_printf(m
, " pe:%d",
1783 uport
->icount
.parity
);
1784 if (uport
->icount
.brk
)
1785 seq_printf(m
, " brk:%d",
1787 if (uport
->icount
.overrun
)
1788 seq_printf(m
, " oe:%d",
1789 uport
->icount
.overrun
);
1791 #define INFOBIT(bit, str) \
1792 if (uport->mctrl & (bit)) \
1793 strncat(stat_buf, (str), sizeof(stat_buf) - \
1794 strlen(stat_buf) - 2)
1795 #define STATBIT(bit, str) \
1796 if (status & (bit)) \
1797 strncat(stat_buf, (str), sizeof(stat_buf) - \
1798 strlen(stat_buf) - 2)
1802 INFOBIT(TIOCM_RTS
, "|RTS");
1803 STATBIT(TIOCM_CTS
, "|CTS");
1804 INFOBIT(TIOCM_DTR
, "|DTR");
1805 STATBIT(TIOCM_DSR
, "|DSR");
1806 STATBIT(TIOCM_CAR
, "|CD");
1807 STATBIT(TIOCM_RNG
, "|RI");
1811 seq_puts(m
, stat_buf
);
1818 static int uart_proc_show(struct seq_file
*m
, void *v
)
1820 struct tty_driver
*ttydrv
= m
->private;
1821 struct uart_driver
*drv
= ttydrv
->driver_state
;
1824 seq_printf(m
, "serinfo:1.0 driver%s%s revision:%s\n",
1826 for (i
= 0; i
< drv
->nr
; i
++)
1827 uart_line_info(m
, drv
, i
);
1831 static int uart_proc_open(struct inode
*inode
, struct file
*file
)
1833 return single_open(file
, uart_proc_show
, PDE(inode
)->data
);
1836 static const struct file_operations uart_proc_fops
= {
1837 .owner
= THIS_MODULE
,
1838 .open
= uart_proc_open
,
1840 .llseek
= seq_lseek
,
1841 .release
= single_release
,
1845 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1847 * uart_console_write - write a console message to a serial port
1848 * @port: the port to write the message
1849 * @s: array of characters
1850 * @count: number of characters in string to write
1851 * @write: function to write character to port
1853 void uart_console_write(struct uart_port
*port
, const char *s
,
1855 void (*putchar
)(struct uart_port
*, int))
1859 for (i
= 0; i
< count
; i
++, s
++) {
1861 putchar(port
, '\r');
1865 EXPORT_SYMBOL_GPL(uart_console_write
);
1868 * Check whether an invalid uart number has been specified, and
1869 * if so, search for the first available port that does have
1872 struct uart_port
* __init
1873 uart_get_console(struct uart_port
*ports
, int nr
, struct console
*co
)
1875 int idx
= co
->index
;
1877 if (idx
< 0 || idx
>= nr
|| (ports
[idx
].iobase
== 0 &&
1878 ports
[idx
].membase
== NULL
))
1879 for (idx
= 0; idx
< nr
; idx
++)
1880 if (ports
[idx
].iobase
!= 0 ||
1881 ports
[idx
].membase
!= NULL
)
1890 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1891 * @options: pointer to option string
1892 * @baud: pointer to an 'int' variable for the baud rate.
1893 * @parity: pointer to an 'int' variable for the parity.
1894 * @bits: pointer to an 'int' variable for the number of data bits.
1895 * @flow: pointer to an 'int' variable for the flow control character.
1897 * uart_parse_options decodes a string containing the serial console
1898 * options. The format of the string is <baud><parity><bits><flow>,
1902 uart_parse_options(char *options
, int *baud
, int *parity
, int *bits
, int *flow
)
1906 *baud
= simple_strtoul(s
, NULL
, 10);
1907 while (*s
>= '0' && *s
<= '9')
1916 EXPORT_SYMBOL_GPL(uart_parse_options
);
1923 static const struct baud_rates baud_rates
[] = {
1924 { 921600, B921600
},
1925 { 460800, B460800
},
1926 { 230400, B230400
},
1927 { 115200, B115200
},
1939 * uart_set_options - setup the serial console parameters
1940 * @port: pointer to the serial ports uart_port structure
1941 * @co: console pointer
1943 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1944 * @bits: number of data bits
1945 * @flow: flow control character - 'r' (rts)
1948 uart_set_options(struct uart_port
*port
, struct console
*co
,
1949 int baud
, int parity
, int bits
, int flow
)
1951 struct ktermios termios
;
1952 static struct ktermios dummy
;
1956 * Ensure that the serial console lock is initialised
1959 spin_lock_init(&port
->lock
);
1960 lockdep_set_class(&port
->lock
, &port_lock_key
);
1962 memset(&termios
, 0, sizeof(struct ktermios
));
1964 termios
.c_cflag
= CREAD
| HUPCL
| CLOCAL
;
1967 * Construct a cflag setting.
1969 for (i
= 0; baud_rates
[i
].rate
; i
++)
1970 if (baud_rates
[i
].rate
<= baud
)
1973 termios
.c_cflag
|= baud_rates
[i
].cflag
;
1976 termios
.c_cflag
|= CS7
;
1978 termios
.c_cflag
|= CS8
;
1982 termios
.c_cflag
|= PARODD
;
1985 termios
.c_cflag
|= PARENB
;
1990 termios
.c_cflag
|= CRTSCTS
;
1993 * some uarts on other side don't support no flow control.
1994 * So we set * DTR in host uart to make them happy
1996 port
->mctrl
|= TIOCM_DTR
;
1998 port
->ops
->set_termios(port
, &termios
, &dummy
);
2000 * Allow the setting of the UART parameters with a NULL console
2004 co
->cflag
= termios
.c_cflag
;
2008 EXPORT_SYMBOL_GPL(uart_set_options
);
2009 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
2011 static void uart_change_pm(struct uart_state
*state
, int pm_state
)
2013 struct uart_port
*port
= state
->uart_port
;
2015 if (state
->pm_state
!= pm_state
) {
2017 port
->ops
->pm(port
, pm_state
, state
->pm_state
);
2018 state
->pm_state
= pm_state
;
2023 struct uart_port
*port
;
2024 struct uart_driver
*driver
;
2027 static int serial_match_port(struct device
*dev
, void *data
)
2029 struct uart_match
*match
= data
;
2030 struct tty_driver
*tty_drv
= match
->driver
->tty_driver
;
2031 dev_t devt
= MKDEV(tty_drv
->major
, tty_drv
->minor_start
) +
2034 return dev
->devt
== devt
; /* Actually, only one tty per port */
2037 int uart_suspend_port(struct uart_driver
*drv
, struct uart_port
*uport
)
2039 struct uart_state
*state
= drv
->state
+ uport
->line
;
2040 struct tty_port
*port
= &state
->port
;
2041 struct device
*tty_dev
;
2042 struct uart_match match
= {uport
, drv
};
2043 struct tty_struct
*tty
;
2045 mutex_lock(&port
->mutex
);
2047 /* Must be inside the mutex lock until we convert to tty_port */
2050 tty_dev
= device_find_child(uport
->dev
, &match
, serial_match_port
);
2051 if (device_may_wakeup(tty_dev
)) {
2052 enable_irq_wake(uport
->irq
);
2053 put_device(tty_dev
);
2054 mutex_unlock(&port
->mutex
);
2057 if (console_suspend_enabled
|| !uart_console(uport
))
2058 uport
->suspended
= 1;
2060 if (port
->flags
& ASYNC_INITIALIZED
) {
2061 const struct uart_ops
*ops
= uport
->ops
;
2064 if (console_suspend_enabled
|| !uart_console(uport
)) {
2065 set_bit(ASYNCB_SUSPENDED
, &port
->flags
);
2066 clear_bit(ASYNCB_INITIALIZED
, &port
->flags
);
2068 spin_lock_irq(&uport
->lock
);
2069 ops
->stop_tx(uport
);
2070 ops
->set_mctrl(uport
, 0);
2071 ops
->stop_rx(uport
);
2072 spin_unlock_irq(&uport
->lock
);
2076 * Wait for the transmitter to empty.
2078 for (tries
= 3; !ops
->tx_empty(uport
) && tries
; tries
--)
2081 printk(KERN_ERR
"%s%s%s%d: Unable to drain "
2083 uport
->dev
? dev_name(uport
->dev
) : "",
2084 uport
->dev
? ": " : "",
2086 drv
->tty_driver
->name_base
+ uport
->line
);
2088 if (console_suspend_enabled
|| !uart_console(uport
))
2089 ops
->shutdown(uport
);
2093 * Disable the console device before suspending.
2095 if (console_suspend_enabled
&& uart_console(uport
))
2096 console_stop(uport
->cons
);
2098 if (console_suspend_enabled
|| !uart_console(uport
))
2099 uart_change_pm(state
, 3);
2101 mutex_unlock(&port
->mutex
);
2106 int uart_resume_port(struct uart_driver
*drv
, struct uart_port
*uport
)
2108 struct uart_state
*state
= drv
->state
+ uport
->line
;
2109 struct tty_port
*port
= &state
->port
;
2110 struct device
*tty_dev
;
2111 struct uart_match match
= {uport
, drv
};
2112 struct ktermios termios
;
2114 mutex_lock(&port
->mutex
);
2116 tty_dev
= device_find_child(uport
->dev
, &match
, serial_match_port
);
2117 if (!uport
->suspended
&& device_may_wakeup(tty_dev
)) {
2118 disable_irq_wake(uport
->irq
);
2119 mutex_unlock(&port
->mutex
);
2122 uport
->suspended
= 0;
2125 * Re-enable the console device after suspending.
2127 if (uart_console(uport
)) {
2128 uart_change_pm(state
, 0);
2129 uport
->ops
->set_termios(uport
, &termios
, NULL
);
2130 console_start(uport
->cons
);
2133 if (port
->flags
& ASYNC_SUSPENDED
) {
2134 const struct uart_ops
*ops
= uport
->ops
;
2137 uart_change_pm(state
, 0);
2138 spin_lock_irq(&uport
->lock
);
2139 ops
->set_mctrl(uport
, 0);
2140 spin_unlock_irq(&uport
->lock
);
2141 if (console_suspend_enabled
|| !uart_console(uport
)) {
2142 /* Protected by port mutex for now */
2143 struct tty_struct
*tty
= port
->tty
;
2144 ret
= ops
->startup(uport
);
2147 uart_change_speed(tty
, state
, NULL
);
2148 spin_lock_irq(&uport
->lock
);
2149 ops
->set_mctrl(uport
, uport
->mctrl
);
2150 ops
->start_tx(uport
);
2151 spin_unlock_irq(&uport
->lock
);
2152 set_bit(ASYNCB_INITIALIZED
, &port
->flags
);
2155 * Failed to resume - maybe hardware went away?
2156 * Clear the "initialized" flag so we won't try
2157 * to call the low level drivers shutdown method.
2159 uart_shutdown(tty
, state
);
2163 clear_bit(ASYNCB_SUSPENDED
, &port
->flags
);
2166 mutex_unlock(&port
->mutex
);
2172 uart_report_port(struct uart_driver
*drv
, struct uart_port
*port
)
2176 switch (port
->iotype
) {
2178 snprintf(address
, sizeof(address
), "I/O 0x%lx", port
->iobase
);
2181 snprintf(address
, sizeof(address
),
2182 "I/O 0x%lx offset 0x%x", port
->iobase
, port
->hub6
);
2189 snprintf(address
, sizeof(address
),
2190 "MMIO 0x%llx", (unsigned long long)port
->mapbase
);
2193 strlcpy(address
, "*unknown*", sizeof(address
));
2197 printk(KERN_INFO
"%s%s%s%d at %s (irq = %d) is a %s\n",
2198 port
->dev
? dev_name(port
->dev
) : "",
2199 port
->dev
? ": " : "",
2201 drv
->tty_driver
->name_base
+ port
->line
,
2202 address
, port
->irq
, uart_type(port
));
2206 uart_configure_port(struct uart_driver
*drv
, struct uart_state
*state
,
2207 struct uart_port
*port
)
2212 * If there isn't a port here, don't do anything further.
2214 if (!port
->iobase
&& !port
->mapbase
&& !port
->membase
)
2218 * Now do the auto configuration stuff. Note that config_port
2219 * is expected to claim the resources and map the port for us.
2222 if (port
->flags
& UPF_AUTO_IRQ
)
2223 flags
|= UART_CONFIG_IRQ
;
2224 if (port
->flags
& UPF_BOOT_AUTOCONF
) {
2225 if (!(port
->flags
& UPF_FIXED_TYPE
)) {
2226 port
->type
= PORT_UNKNOWN
;
2227 flags
|= UART_CONFIG_TYPE
;
2229 port
->ops
->config_port(port
, flags
);
2232 if (port
->type
!= PORT_UNKNOWN
) {
2233 unsigned long flags
;
2235 uart_report_port(drv
, port
);
2237 /* Power up port for set_mctrl() */
2238 uart_change_pm(state
, 0);
2241 * Ensure that the modem control lines are de-activated.
2242 * keep the DTR setting that is set in uart_set_options()
2243 * We probably don't need a spinlock around this, but
2245 spin_lock_irqsave(&port
->lock
, flags
);
2246 port
->ops
->set_mctrl(port
, port
->mctrl
& TIOCM_DTR
);
2247 spin_unlock_irqrestore(&port
->lock
, flags
);
2250 * If this driver supports console, and it hasn't been
2251 * successfully registered yet, try to re-register it.
2252 * It may be that the port was not available.
2254 if (port
->cons
&& !(port
->cons
->flags
& CON_ENABLED
))
2255 register_console(port
->cons
);
2258 * Power down all ports by default, except the
2259 * console if we have one.
2261 if (!uart_console(port
))
2262 uart_change_pm(state
, 3);
2266 #ifdef CONFIG_CONSOLE_POLL
2268 static int uart_poll_init(struct tty_driver
*driver
, int line
, char *options
)
2270 struct uart_driver
*drv
= driver
->driver_state
;
2271 struct uart_state
*state
= drv
->state
+ line
;
2272 struct uart_port
*port
;
2278 if (!state
|| !state
->uart_port
)
2281 port
= state
->uart_port
;
2282 if (!(port
->ops
->poll_get_char
&& port
->ops
->poll_put_char
))
2286 uart_parse_options(options
, &baud
, &parity
, &bits
, &flow
);
2287 return uart_set_options(port
, NULL
, baud
, parity
, bits
, flow
);
2293 static int uart_poll_get_char(struct tty_driver
*driver
, int line
)
2295 struct uart_driver
*drv
= driver
->driver_state
;
2296 struct uart_state
*state
= drv
->state
+ line
;
2297 struct uart_port
*port
;
2299 if (!state
|| !state
->uart_port
)
2302 port
= state
->uart_port
;
2303 return port
->ops
->poll_get_char(port
);
2306 static void uart_poll_put_char(struct tty_driver
*driver
, int line
, char ch
)
2308 struct uart_driver
*drv
= driver
->driver_state
;
2309 struct uart_state
*state
= drv
->state
+ line
;
2310 struct uart_port
*port
;
2312 if (!state
|| !state
->uart_port
)
2315 port
= state
->uart_port
;
2316 port
->ops
->poll_put_char(port
, ch
);
2320 static const struct tty_operations uart_ops
= {
2322 .close
= uart_close
,
2323 .write
= uart_write
,
2324 .put_char
= uart_put_char
,
2325 .flush_chars
= uart_flush_chars
,
2326 .write_room
= uart_write_room
,
2327 .chars_in_buffer
= uart_chars_in_buffer
,
2328 .flush_buffer
= uart_flush_buffer
,
2329 .ioctl
= uart_ioctl
,
2330 .throttle
= uart_throttle
,
2331 .unthrottle
= uart_unthrottle
,
2332 .send_xchar
= uart_send_xchar
,
2333 .set_termios
= uart_set_termios
,
2334 .set_ldisc
= uart_set_ldisc
,
2336 .start
= uart_start
,
2337 .hangup
= uart_hangup
,
2338 .break_ctl
= uart_break_ctl
,
2339 .wait_until_sent
= uart_wait_until_sent
,
2340 #ifdef CONFIG_PROC_FS
2341 .proc_fops
= &uart_proc_fops
,
2343 .tiocmget
= uart_tiocmget
,
2344 .tiocmset
= uart_tiocmset
,
2345 #ifdef CONFIG_CONSOLE_POLL
2346 .poll_init
= uart_poll_init
,
2347 .poll_get_char
= uart_poll_get_char
,
2348 .poll_put_char
= uart_poll_put_char
,
2353 * uart_register_driver - register a driver with the uart core layer
2354 * @drv: low level driver structure
2356 * Register a uart driver with the core driver. We in turn register
2357 * with the tty layer, and initialise the core driver per-port state.
2359 * We have a proc file in /proc/tty/driver which is named after the
2362 * drv->port should be NULL, and the per-port structures should be
2363 * registered using uart_add_one_port after this call has succeeded.
2365 int uart_register_driver(struct uart_driver
*drv
)
2367 struct tty_driver
*normal
;
2373 * Maybe we should be using a slab cache for this, especially if
2374 * we have a large number of ports to handle.
2376 drv
->state
= kzalloc(sizeof(struct uart_state
) * drv
->nr
, GFP_KERNEL
);
2380 normal
= alloc_tty_driver(drv
->nr
);
2384 drv
->tty_driver
= normal
;
2386 normal
->owner
= drv
->owner
;
2387 normal
->driver_name
= drv
->driver_name
;
2388 normal
->name
= drv
->dev_name
;
2389 normal
->major
= drv
->major
;
2390 normal
->minor_start
= drv
->minor
;
2391 normal
->type
= TTY_DRIVER_TYPE_SERIAL
;
2392 normal
->subtype
= SERIAL_TYPE_NORMAL
;
2393 normal
->init_termios
= tty_std_termios
;
2394 normal
->init_termios
.c_cflag
= B9600
| CS8
| CREAD
| HUPCL
| CLOCAL
;
2395 normal
->init_termios
.c_ispeed
= normal
->init_termios
.c_ospeed
= 9600;
2396 normal
->flags
= TTY_DRIVER_REAL_RAW
| TTY_DRIVER_DYNAMIC_DEV
;
2397 normal
->driver_state
= drv
;
2398 tty_set_operations(normal
, &uart_ops
);
2401 * Initialise the UART state(s).
2403 for (i
= 0; i
< drv
->nr
; i
++) {
2404 struct uart_state
*state
= drv
->state
+ i
;
2405 struct tty_port
*port
= &state
->port
;
2407 tty_port_init(port
);
2408 port
->close_delay
= 500; /* .5 seconds */
2409 port
->closing_wait
= 30000; /* 30 seconds */
2410 tasklet_init(&state
->tlet
, uart_tasklet_action
,
2411 (unsigned long)state
);
2414 retval
= tty_register_driver(normal
);
2418 put_tty_driver(normal
);
2426 * uart_unregister_driver - remove a driver from the uart core layer
2427 * @drv: low level driver structure
2429 * Remove all references to a driver from the core driver. The low
2430 * level driver must have removed all its ports via the
2431 * uart_remove_one_port() if it registered them with uart_add_one_port().
2432 * (ie, drv->port == NULL)
2434 void uart_unregister_driver(struct uart_driver
*drv
)
2436 struct tty_driver
*p
= drv
->tty_driver
;
2437 tty_unregister_driver(p
);
2440 drv
->tty_driver
= NULL
;
2443 struct tty_driver
*uart_console_device(struct console
*co
, int *index
)
2445 struct uart_driver
*p
= co
->data
;
2447 return p
->tty_driver
;
2451 * uart_add_one_port - attach a driver-defined port structure
2452 * @drv: pointer to the uart low level driver structure for this port
2453 * @uport: uart port structure to use for this port.
2455 * This allows the driver to register its own uart_port structure
2456 * with the core driver. The main purpose is to allow the low
2457 * level uart drivers to expand uart_port, rather than having yet
2458 * more levels of structures.
2460 int uart_add_one_port(struct uart_driver
*drv
, struct uart_port
*uport
)
2462 struct uart_state
*state
;
2463 struct tty_port
*port
;
2465 struct device
*tty_dev
;
2467 BUG_ON(in_interrupt());
2469 if (uport
->line
>= drv
->nr
)
2472 state
= drv
->state
+ uport
->line
;
2473 port
= &state
->port
;
2475 mutex_lock(&port_mutex
);
2476 mutex_lock(&port
->mutex
);
2477 if (state
->uart_port
) {
2482 state
->uart_port
= uport
;
2483 state
->pm_state
= -1;
2485 uport
->cons
= drv
->cons
;
2486 uport
->state
= state
;
2489 * If this port is a console, then the spinlock is already
2492 if (!(uart_console(uport
) && (uport
->cons
->flags
& CON_ENABLED
))) {
2493 spin_lock_init(&uport
->lock
);
2494 lockdep_set_class(&uport
->lock
, &port_lock_key
);
2497 uart_configure_port(drv
, state
, uport
);
2500 * Register the port whether it's detected or not. This allows
2501 * setserial to be used to alter this ports parameters.
2503 tty_dev
= tty_register_device(drv
->tty_driver
, uport
->line
, uport
->dev
);
2504 if (likely(!IS_ERR(tty_dev
))) {
2505 device_init_wakeup(tty_dev
, 1);
2506 device_set_wakeup_enable(tty_dev
, 0);
2508 printk(KERN_ERR
"Cannot register tty device on line %d\n",
2512 * Ensure UPF_DEAD is not set.
2514 uport
->flags
&= ~UPF_DEAD
;
2517 mutex_unlock(&port
->mutex
);
2518 mutex_unlock(&port_mutex
);
2524 * uart_remove_one_port - detach a driver defined port structure
2525 * @drv: pointer to the uart low level driver structure for this port
2526 * @uport: uart port structure for this port
2528 * This unhooks (and hangs up) the specified port structure from the
2529 * core driver. No further calls will be made to the low-level code
2532 int uart_remove_one_port(struct uart_driver
*drv
, struct uart_port
*uport
)
2534 struct uart_state
*state
= drv
->state
+ uport
->line
;
2535 struct tty_port
*port
= &state
->port
;
2537 BUG_ON(in_interrupt());
2539 if (state
->uart_port
!= uport
)
2540 printk(KERN_ALERT
"Removing wrong port: %p != %p\n",
2541 state
->uart_port
, uport
);
2543 mutex_lock(&port_mutex
);
2546 * Mark the port "dead" - this prevents any opens from
2547 * succeeding while we shut down the port.
2549 mutex_lock(&port
->mutex
);
2550 uport
->flags
|= UPF_DEAD
;
2551 mutex_unlock(&port
->mutex
);
2554 * Remove the devices from the tty layer
2556 tty_unregister_device(drv
->tty_driver
, uport
->line
);
2559 tty_vhangup(port
->tty
);
2562 * Free the port IO and memory resources, if any.
2564 if (uport
->type
!= PORT_UNKNOWN
)
2565 uport
->ops
->release_port(uport
);
2568 * Indicate that there isn't a port here anymore.
2570 uport
->type
= PORT_UNKNOWN
;
2573 * Kill the tasklet, and free resources.
2575 tasklet_kill(&state
->tlet
);
2577 state
->uart_port
= NULL
;
2578 mutex_unlock(&port_mutex
);
2584 * Are the two ports equivalent?
2586 int uart_match_port(struct uart_port
*port1
, struct uart_port
*port2
)
2588 if (port1
->iotype
!= port2
->iotype
)
2591 switch (port1
->iotype
) {
2593 return (port1
->iobase
== port2
->iobase
);
2595 return (port1
->iobase
== port2
->iobase
) &&
2596 (port1
->hub6
== port2
->hub6
);
2602 return (port1
->mapbase
== port2
->mapbase
);
2606 EXPORT_SYMBOL(uart_match_port
);
2608 EXPORT_SYMBOL(uart_write_wakeup
);
2609 EXPORT_SYMBOL(uart_register_driver
);
2610 EXPORT_SYMBOL(uart_unregister_driver
);
2611 EXPORT_SYMBOL(uart_suspend_port
);
2612 EXPORT_SYMBOL(uart_resume_port
);
2613 EXPORT_SYMBOL(uart_add_one_port
);
2614 EXPORT_SYMBOL(uart_remove_one_port
);
2616 MODULE_DESCRIPTION("Serial driver core");
2617 MODULE_LICENSE("GPL");