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/config.h>
26 #include <linux/module.h>
27 #include <linux/tty.h>
28 #include <linux/slab.h>
29 #include <linux/init.h>
30 #include <linux/console.h>
31 #include <linux/serial_core.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/delay.h>
38 #include <asm/uaccess.h>
42 #define DPRINTK(x...) printk(x)
44 #define DPRINTK(x...) do { } while (0)
48 * This is used to lock changes in serial line configuration.
50 static DECLARE_MUTEX(port_sem
);
52 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
54 #define uart_users(state) ((state)->count + ((state)->info ? (state)->info->blocked_open : 0))
56 #ifdef CONFIG_SERIAL_CORE_CONSOLE
57 #define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
59 #define uart_console(port) (0)
62 static void uart_change_speed(struct uart_state
*state
, struct termios
*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
;
73 tasklet_schedule(&info
->tlet
);
76 static void uart_stop(struct tty_struct
*tty
)
78 struct uart_state
*state
= tty
->driver_data
;
79 struct uart_port
*port
= state
->port
;
82 spin_lock_irqsave(&port
->lock
, flags
);
83 port
->ops
->stop_tx(port
);
84 spin_unlock_irqrestore(&port
->lock
, flags
);
87 static void __uart_start(struct tty_struct
*tty
)
89 struct uart_state
*state
= tty
->driver_data
;
90 struct uart_port
*port
= state
->port
;
92 if (!uart_circ_empty(&state
->info
->xmit
) && state
->info
->xmit
.buf
&&
93 !tty
->stopped
&& !tty
->hw_stopped
)
94 port
->ops
->start_tx(port
);
97 static void uart_start(struct tty_struct
*tty
)
99 struct uart_state
*state
= tty
->driver_data
;
100 struct uart_port
*port
= state
->port
;
103 spin_lock_irqsave(&port
->lock
, flags
);
105 spin_unlock_irqrestore(&port
->lock
, flags
);
108 static void uart_tasklet_action(unsigned long data
)
110 struct uart_state
*state
= (struct uart_state
*)data
;
111 tty_wakeup(state
->info
->tty
);
115 uart_update_mctrl(struct uart_port
*port
, unsigned int set
, unsigned int clear
)
120 spin_lock_irqsave(&port
->lock
, flags
);
122 port
->mctrl
= (old
& ~clear
) | set
;
123 if (old
!= port
->mctrl
)
124 port
->ops
->set_mctrl(port
, port
->mctrl
);
125 spin_unlock_irqrestore(&port
->lock
, flags
);
128 #define uart_set_mctrl(port,set) uart_update_mctrl(port,set,0)
129 #define uart_clear_mctrl(port,clear) uart_update_mctrl(port,0,clear)
132 * Startup the port. This will be called once per open. All calls
133 * will be serialised by the per-port semaphore.
135 static int uart_startup(struct uart_state
*state
, int init_hw
)
137 struct uart_info
*info
= state
->info
;
138 struct uart_port
*port
= state
->port
;
142 if (info
->flags
& UIF_INITIALIZED
)
146 * Set the TTY IO error marker - we will only clear this
147 * once we have successfully opened the port. Also set
148 * up the tty->alt_speed kludge
150 set_bit(TTY_IO_ERROR
, &info
->tty
->flags
);
152 if (port
->type
== PORT_UNKNOWN
)
156 * Initialise and allocate the transmit and temporary
159 if (!info
->xmit
.buf
) {
160 page
= get_zeroed_page(GFP_KERNEL
);
164 info
->xmit
.buf
= (unsigned char *) page
;
165 uart_circ_clear(&info
->xmit
);
168 retval
= port
->ops
->startup(port
);
172 * Initialise the hardware port settings.
174 uart_change_speed(state
, NULL
);
177 * Setup the RTS and DTR signals once the
178 * port is open and ready to respond.
180 if (info
->tty
->termios
->c_cflag
& CBAUD
)
181 uart_set_mctrl(port
, TIOCM_RTS
| TIOCM_DTR
);
184 if (info
->flags
& UIF_CTS_FLOW
) {
185 spin_lock_irq(&port
->lock
);
186 if (!(port
->ops
->get_mctrl(port
) & TIOCM_CTS
))
187 info
->tty
->hw_stopped
= 1;
188 spin_unlock_irq(&port
->lock
);
191 info
->flags
|= UIF_INITIALIZED
;
193 clear_bit(TTY_IO_ERROR
, &info
->tty
->flags
);
196 if (retval
&& capable(CAP_SYS_ADMIN
))
203 * This routine will shutdown a serial port; interrupts are disabled, and
204 * DTR is dropped if the hangup on close termio flag is on. Calls to
205 * uart_shutdown are serialised by the per-port semaphore.
207 static void uart_shutdown(struct uart_state
*state
)
209 struct uart_info
*info
= state
->info
;
210 struct uart_port
*port
= state
->port
;
212 if (!(info
->flags
& UIF_INITIALIZED
))
216 * Turn off DTR and RTS early.
218 if (!info
->tty
|| (info
->tty
->termios
->c_cflag
& HUPCL
))
219 uart_clear_mctrl(port
, TIOCM_DTR
| TIOCM_RTS
);
222 * clear delta_msr_wait queue to avoid mem leaks: we may free
223 * the irq here so the queue might never be woken up. Note
224 * that we won't end up waiting on delta_msr_wait again since
225 * any outstanding file descriptors should be pointing at
226 * hung_up_tty_fops now.
228 wake_up_interruptible(&info
->delta_msr_wait
);
231 * Free the IRQ and disable the port.
233 port
->ops
->shutdown(port
);
236 * Ensure that the IRQ handler isn't running on another CPU.
238 synchronize_irq(port
->irq
);
241 * Free the transmit buffer page.
243 if (info
->xmit
.buf
) {
244 free_page((unsigned long)info
->xmit
.buf
);
245 info
->xmit
.buf
= NULL
;
249 * kill off our tasklet
251 tasklet_kill(&info
->tlet
);
253 set_bit(TTY_IO_ERROR
, &info
->tty
->flags
);
255 info
->flags
&= ~UIF_INITIALIZED
;
259 * uart_update_timeout - update per-port FIFO timeout.
260 * @port: uart_port structure describing the port
261 * @cflag: termios cflag value
262 * @baud: speed of the port
264 * Set the port FIFO timeout value. The @cflag value should
265 * reflect the actual hardware settings.
268 uart_update_timeout(struct uart_port
*port
, unsigned int cflag
,
273 /* byte size and parity */
274 switch (cflag
& CSIZE
) {
295 * The total number of bits to be transmitted in the fifo.
297 bits
= bits
* port
->fifosize
;
300 * Figure the timeout to send the above number of bits.
301 * Add .02 seconds of slop
303 port
->timeout
= (HZ
* bits
) / baud
+ HZ
/50;
306 EXPORT_SYMBOL(uart_update_timeout
);
309 * uart_get_baud_rate - return baud rate for a particular port
310 * @port: uart_port structure describing the port in question.
311 * @termios: desired termios settings.
312 * @old: old termios (or NULL)
313 * @min: minimum acceptable baud rate
314 * @max: maximum acceptable baud rate
316 * Decode the termios structure into a numeric baud rate,
317 * taking account of the magic 38400 baud rate (with spd_*
318 * flags), and mapping the %B0 rate to 9600 baud.
320 * If the new baud rate is invalid, try the old termios setting.
321 * If it's still invalid, we try 9600 baud.
323 * Update the @termios structure to reflect the baud rate
324 * we're actually going to be using.
327 uart_get_baud_rate(struct uart_port
*port
, struct termios
*termios
,
328 struct termios
*old
, unsigned int min
, unsigned int max
)
330 unsigned int try, baud
, altbaud
= 38400;
331 unsigned int flags
= port
->flags
& UPF_SPD_MASK
;
333 if (flags
== UPF_SPD_HI
)
335 if (flags
== UPF_SPD_VHI
)
337 if (flags
== UPF_SPD_SHI
)
339 if (flags
== UPF_SPD_WARP
)
342 for (try = 0; try < 2; try++) {
343 baud
= tty_termios_baud_rate(termios
);
346 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
353 * Special case: B0 rate.
358 if (baud
>= min
&& baud
<= max
)
362 * Oops, the quotient was zero. Try again with
363 * the old baud rate if possible.
365 termios
->c_cflag
&= ~CBAUD
;
367 termios
->c_cflag
|= old
->c_cflag
& CBAUD
;
373 * As a last resort, if the quotient is zero,
374 * default to 9600 bps
376 termios
->c_cflag
|= B9600
;
382 EXPORT_SYMBOL(uart_get_baud_rate
);
385 * uart_get_divisor - return uart clock divisor
386 * @port: uart_port structure describing the port.
387 * @baud: desired baud rate
389 * Calculate the uart clock divisor for the port.
392 uart_get_divisor(struct uart_port
*port
, unsigned int baud
)
397 * Old custom speed handling.
399 if (baud
== 38400 && (port
->flags
& UPF_SPD_MASK
) == UPF_SPD_CUST
)
400 quot
= port
->custom_divisor
;
402 quot
= (port
->uartclk
+ (8 * baud
)) / (16 * baud
);
407 EXPORT_SYMBOL(uart_get_divisor
);
410 uart_change_speed(struct uart_state
*state
, struct termios
*old_termios
)
412 struct tty_struct
*tty
= state
->info
->tty
;
413 struct uart_port
*port
= state
->port
;
414 struct termios
*termios
;
417 * If we have no tty, termios, or the port does not exist,
418 * then we can't set the parameters for this port.
420 if (!tty
|| !tty
->termios
|| port
->type
== PORT_UNKNOWN
)
423 termios
= tty
->termios
;
426 * Set flags based on termios cflag
428 if (termios
->c_cflag
& CRTSCTS
)
429 state
->info
->flags
|= UIF_CTS_FLOW
;
431 state
->info
->flags
&= ~UIF_CTS_FLOW
;
433 if (termios
->c_cflag
& CLOCAL
)
434 state
->info
->flags
&= ~UIF_CHECK_CD
;
436 state
->info
->flags
|= UIF_CHECK_CD
;
438 port
->ops
->set_termios(port
, termios
, old_termios
);
442 __uart_put_char(struct uart_port
*port
, struct circ_buf
*circ
, unsigned char c
)
449 spin_lock_irqsave(&port
->lock
, flags
);
450 if (uart_circ_chars_free(circ
) != 0) {
451 circ
->buf
[circ
->head
] = c
;
452 circ
->head
= (circ
->head
+ 1) & (UART_XMIT_SIZE
- 1);
454 spin_unlock_irqrestore(&port
->lock
, flags
);
457 static void uart_put_char(struct tty_struct
*tty
, unsigned char ch
)
459 struct uart_state
*state
= tty
->driver_data
;
461 __uart_put_char(state
->port
, &state
->info
->xmit
, ch
);
464 static void uart_flush_chars(struct tty_struct
*tty
)
470 uart_write(struct tty_struct
*tty
, const unsigned char * buf
, int count
)
472 struct uart_state
*state
= tty
->driver_data
;
473 struct uart_port
*port
= state
->port
;
474 struct circ_buf
*circ
= &state
->info
->xmit
;
481 spin_lock_irqsave(&port
->lock
, flags
);
483 c
= CIRC_SPACE_TO_END(circ
->head
, circ
->tail
, UART_XMIT_SIZE
);
488 memcpy(circ
->buf
+ circ
->head
, buf
, c
);
489 circ
->head
= (circ
->head
+ c
) & (UART_XMIT_SIZE
- 1);
494 spin_unlock_irqrestore(&port
->lock
, flags
);
500 static int uart_write_room(struct tty_struct
*tty
)
502 struct uart_state
*state
= tty
->driver_data
;
504 return uart_circ_chars_free(&state
->info
->xmit
);
507 static int uart_chars_in_buffer(struct tty_struct
*tty
)
509 struct uart_state
*state
= tty
->driver_data
;
511 return uart_circ_chars_pending(&state
->info
->xmit
);
514 static void uart_flush_buffer(struct tty_struct
*tty
)
516 struct uart_state
*state
= tty
->driver_data
;
517 struct uart_port
*port
= state
->port
;
520 DPRINTK("uart_flush_buffer(%d) called\n", tty
->index
);
522 spin_lock_irqsave(&port
->lock
, flags
);
523 uart_circ_clear(&state
->info
->xmit
);
524 spin_unlock_irqrestore(&port
->lock
, flags
);
529 * This function is used to send a high-priority XON/XOFF character to
532 static void uart_send_xchar(struct tty_struct
*tty
, char ch
)
534 struct uart_state
*state
= tty
->driver_data
;
535 struct uart_port
*port
= state
->port
;
538 if (port
->ops
->send_xchar
)
539 port
->ops
->send_xchar(port
, ch
);
543 spin_lock_irqsave(&port
->lock
, flags
);
544 port
->ops
->start_tx(port
);
545 spin_unlock_irqrestore(&port
->lock
, flags
);
550 static void uart_throttle(struct tty_struct
*tty
)
552 struct uart_state
*state
= tty
->driver_data
;
555 uart_send_xchar(tty
, STOP_CHAR(tty
));
557 if (tty
->termios
->c_cflag
& CRTSCTS
)
558 uart_clear_mctrl(state
->port
, TIOCM_RTS
);
561 static void uart_unthrottle(struct tty_struct
*tty
)
563 struct uart_state
*state
= tty
->driver_data
;
564 struct uart_port
*port
= state
->port
;
570 uart_send_xchar(tty
, START_CHAR(tty
));
573 if (tty
->termios
->c_cflag
& CRTSCTS
)
574 uart_set_mctrl(port
, TIOCM_RTS
);
577 static int uart_get_info(struct uart_state
*state
,
578 struct serial_struct __user
*retinfo
)
580 struct uart_port
*port
= state
->port
;
581 struct serial_struct tmp
;
583 memset(&tmp
, 0, sizeof(tmp
));
584 tmp
.type
= port
->type
;
585 tmp
.line
= port
->line
;
586 tmp
.port
= port
->iobase
;
587 if (HIGH_BITS_OFFSET
)
588 tmp
.port_high
= (long) port
->iobase
>> HIGH_BITS_OFFSET
;
590 tmp
.flags
= port
->flags
;
591 tmp
.xmit_fifo_size
= port
->fifosize
;
592 tmp
.baud_base
= port
->uartclk
/ 16;
593 tmp
.close_delay
= state
->close_delay
/ 10;
594 tmp
.closing_wait
= state
->closing_wait
== USF_CLOSING_WAIT_NONE
?
595 ASYNC_CLOSING_WAIT_NONE
:
596 state
->closing_wait
/ 10;
597 tmp
.custom_divisor
= port
->custom_divisor
;
598 tmp
.hub6
= port
->hub6
;
599 tmp
.io_type
= port
->iotype
;
600 tmp
.iomem_reg_shift
= port
->regshift
;
601 tmp
.iomem_base
= (void *)port
->mapbase
;
603 if (copy_to_user(retinfo
, &tmp
, sizeof(*retinfo
)))
608 static int uart_set_info(struct uart_state
*state
,
609 struct serial_struct __user
*newinfo
)
611 struct serial_struct new_serial
;
612 struct uart_port
*port
= state
->port
;
613 unsigned long new_port
;
614 unsigned int change_irq
, change_port
, old_flags
, closing_wait
;
615 unsigned int old_custom_divisor
, close_delay
;
618 if (copy_from_user(&new_serial
, newinfo
, sizeof(new_serial
)))
621 new_port
= new_serial
.port
;
622 if (HIGH_BITS_OFFSET
)
623 new_port
+= (unsigned long) new_serial
.port_high
<< HIGH_BITS_OFFSET
;
625 new_serial
.irq
= irq_canonicalize(new_serial
.irq
);
626 close_delay
= new_serial
.close_delay
* 10;
627 closing_wait
= new_serial
.closing_wait
== ASYNC_CLOSING_WAIT_NONE
?
628 USF_CLOSING_WAIT_NONE
: new_serial
.closing_wait
* 10;
631 * This semaphore protects state->count. It is also
632 * very useful to prevent opens. Also, take the
633 * port configuration semaphore to make sure that a
634 * module insertion/removal doesn't change anything
639 change_irq
= new_serial
.irq
!= port
->irq
;
642 * Since changing the 'type' of the port changes its resource
643 * allocations, we should treat type changes the same as
646 change_port
= new_port
!= port
->iobase
||
647 (unsigned long)new_serial
.iomem_base
!= port
->mapbase
||
648 new_serial
.hub6
!= port
->hub6
||
649 new_serial
.io_type
!= port
->iotype
||
650 new_serial
.iomem_reg_shift
!= port
->regshift
||
651 new_serial
.type
!= port
->type
;
653 old_flags
= port
->flags
;
654 old_custom_divisor
= port
->custom_divisor
;
656 if (!capable(CAP_SYS_ADMIN
)) {
658 if (change_irq
|| change_port
||
659 (new_serial
.baud_base
!= port
->uartclk
/ 16) ||
660 (close_delay
!= state
->close_delay
) ||
661 (closing_wait
!= state
->closing_wait
) ||
662 (new_serial
.xmit_fifo_size
!= port
->fifosize
) ||
663 (((new_serial
.flags
^ old_flags
) & ~UPF_USR_MASK
) != 0))
665 port
->flags
= ((port
->flags
& ~UPF_USR_MASK
) |
666 (new_serial
.flags
& UPF_USR_MASK
));
667 port
->custom_divisor
= new_serial
.custom_divisor
;
672 * Ask the low level driver to verify the settings.
674 if (port
->ops
->verify_port
)
675 retval
= port
->ops
->verify_port(port
, &new_serial
);
677 if ((new_serial
.irq
>= NR_IRQS
) || (new_serial
.irq
< 0) ||
678 (new_serial
.baud_base
< 9600))
684 if (change_port
|| change_irq
) {
688 * Make sure that we are the sole user of this port.
690 if (uart_users(state
) > 1)
694 * We need to shutdown the serial port at the old
695 * port/type/irq combination.
697 uart_shutdown(state
);
701 unsigned long old_iobase
, old_mapbase
;
702 unsigned int old_type
, old_iotype
, old_hub6
, old_shift
;
704 old_iobase
= port
->iobase
;
705 old_mapbase
= port
->mapbase
;
706 old_type
= port
->type
;
707 old_hub6
= port
->hub6
;
708 old_iotype
= port
->iotype
;
709 old_shift
= port
->regshift
;
712 * Free and release old regions
714 if (old_type
!= PORT_UNKNOWN
)
715 port
->ops
->release_port(port
);
717 port
->iobase
= new_port
;
718 port
->type
= new_serial
.type
;
719 port
->hub6
= new_serial
.hub6
;
720 port
->iotype
= new_serial
.io_type
;
721 port
->regshift
= new_serial
.iomem_reg_shift
;
722 port
->mapbase
= (unsigned long)new_serial
.iomem_base
;
725 * Claim and map the new regions
727 if (port
->type
!= PORT_UNKNOWN
) {
728 retval
= port
->ops
->request_port(port
);
730 /* Always success - Jean II */
735 * If we fail to request resources for the
736 * new port, try to restore the old settings.
738 if (retval
&& old_type
!= PORT_UNKNOWN
) {
739 port
->iobase
= old_iobase
;
740 port
->type
= old_type
;
741 port
->hub6
= old_hub6
;
742 port
->iotype
= old_iotype
;
743 port
->regshift
= old_shift
;
744 port
->mapbase
= old_mapbase
;
745 retval
= port
->ops
->request_port(port
);
747 * If we failed to restore the old settings,
751 port
->type
= PORT_UNKNOWN
;
760 port
->irq
= new_serial
.irq
;
761 port
->uartclk
= new_serial
.baud_base
* 16;
762 port
->flags
= (port
->flags
& ~UPF_CHANGE_MASK
) |
763 (new_serial
.flags
& UPF_CHANGE_MASK
);
764 port
->custom_divisor
= new_serial
.custom_divisor
;
765 state
->close_delay
= close_delay
;
766 state
->closing_wait
= closing_wait
;
767 port
->fifosize
= new_serial
.xmit_fifo_size
;
768 if (state
->info
->tty
)
769 state
->info
->tty
->low_latency
=
770 (port
->flags
& UPF_LOW_LATENCY
) ? 1 : 0;
774 if (port
->type
== PORT_UNKNOWN
)
776 if (state
->info
->flags
& UIF_INITIALIZED
) {
777 if (((old_flags
^ port
->flags
) & UPF_SPD_MASK
) ||
778 old_custom_divisor
!= port
->custom_divisor
) {
780 * If they're setting up a custom divisor or speed,
781 * instead of clearing it, then bitch about it. No
782 * need to rate-limit; it's CAP_SYS_ADMIN only.
784 if (port
->flags
& UPF_SPD_MASK
) {
787 "%s sets custom speed on %s. This "
788 "is deprecated.\n", current
->comm
,
789 tty_name(state
->info
->tty
, buf
));
791 uart_change_speed(state
, NULL
);
794 retval
= uart_startup(state
, 1);
802 * uart_get_lsr_info - get line status register info.
803 * Note: uart_ioctl protects us against hangups.
805 static int uart_get_lsr_info(struct uart_state
*state
,
806 unsigned int __user
*value
)
808 struct uart_port
*port
= state
->port
;
811 result
= port
->ops
->tx_empty(port
);
814 * If we're about to load something into the transmit
815 * register, we'll pretend the transmitter isn't empty to
816 * avoid a race condition (depending on when the transmit
817 * interrupt happens).
820 ((uart_circ_chars_pending(&state
->info
->xmit
) > 0) &&
821 !state
->info
->tty
->stopped
&& !state
->info
->tty
->hw_stopped
))
822 result
&= ~TIOCSER_TEMT
;
824 return put_user(result
, value
);
827 static int uart_tiocmget(struct tty_struct
*tty
, struct file
*file
)
829 struct uart_state
*state
= tty
->driver_data
;
830 struct uart_port
*port
= state
->port
;
834 if ((!file
|| !tty_hung_up_p(file
)) &&
835 !(tty
->flags
& (1 << TTY_IO_ERROR
))) {
836 result
= port
->mctrl
;
838 spin_lock_irq(&port
->lock
);
839 result
|= port
->ops
->get_mctrl(port
);
840 spin_unlock_irq(&port
->lock
);
848 uart_tiocmset(struct tty_struct
*tty
, struct file
*file
,
849 unsigned int set
, unsigned int clear
)
851 struct uart_state
*state
= tty
->driver_data
;
852 struct uart_port
*port
= state
->port
;
856 if ((!file
|| !tty_hung_up_p(file
)) &&
857 !(tty
->flags
& (1 << TTY_IO_ERROR
))) {
858 uart_update_mctrl(port
, set
, clear
);
865 static void uart_break_ctl(struct tty_struct
*tty
, int break_state
)
867 struct uart_state
*state
= tty
->driver_data
;
868 struct uart_port
*port
= state
->port
;
870 BUG_ON(!kernel_locked());
874 if (port
->type
!= PORT_UNKNOWN
)
875 port
->ops
->break_ctl(port
, break_state
);
880 static int uart_do_autoconfig(struct uart_state
*state
)
882 struct uart_port
*port
= state
->port
;
885 if (!capable(CAP_SYS_ADMIN
))
889 * Take the per-port semaphore. This prevents count from
890 * changing, and hence any extra opens of the port while
891 * we're auto-configuring.
893 if (down_interruptible(&state
->sem
))
897 if (uart_users(state
) == 1) {
898 uart_shutdown(state
);
901 * If we already have a port type configured,
902 * we must release its resources.
904 if (port
->type
!= PORT_UNKNOWN
)
905 port
->ops
->release_port(port
);
907 flags
= UART_CONFIG_TYPE
;
908 if (port
->flags
& UPF_AUTO_IRQ
)
909 flags
|= UART_CONFIG_IRQ
;
912 * This will claim the ports resources if
915 port
->ops
->config_port(port
, flags
);
917 ret
= uart_startup(state
, 1);
924 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
925 * - mask passed in arg for lines of interest
926 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
927 * Caller should use TIOCGICOUNT to see which one it was
930 uart_wait_modem_status(struct uart_state
*state
, unsigned long arg
)
932 struct uart_port
*port
= state
->port
;
933 DECLARE_WAITQUEUE(wait
, current
);
934 struct uart_icount cprev
, cnow
;
938 * note the counters on entry
940 spin_lock_irq(&port
->lock
);
941 memcpy(&cprev
, &port
->icount
, sizeof(struct uart_icount
));
944 * Force modem status interrupts on
946 port
->ops
->enable_ms(port
);
947 spin_unlock_irq(&port
->lock
);
949 add_wait_queue(&state
->info
->delta_msr_wait
, &wait
);
951 spin_lock_irq(&port
->lock
);
952 memcpy(&cnow
, &port
->icount
, sizeof(struct uart_icount
));
953 spin_unlock_irq(&port
->lock
);
955 set_current_state(TASK_INTERRUPTIBLE
);
957 if (((arg
& TIOCM_RNG
) && (cnow
.rng
!= cprev
.rng
)) ||
958 ((arg
& TIOCM_DSR
) && (cnow
.dsr
!= cprev
.dsr
)) ||
959 ((arg
& TIOCM_CD
) && (cnow
.dcd
!= cprev
.dcd
)) ||
960 ((arg
& TIOCM_CTS
) && (cnow
.cts
!= cprev
.cts
))) {
967 /* see if a signal did it */
968 if (signal_pending(current
)) {
976 current
->state
= TASK_RUNNING
;
977 remove_wait_queue(&state
->info
->delta_msr_wait
, &wait
);
983 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
984 * Return: write counters to the user passed counter struct
985 * NB: both 1->0 and 0->1 transitions are counted except for
986 * RI where only 0->1 is counted.
988 static int uart_get_count(struct uart_state
*state
,
989 struct serial_icounter_struct __user
*icnt
)
991 struct serial_icounter_struct icount
;
992 struct uart_icount cnow
;
993 struct uart_port
*port
= state
->port
;
995 spin_lock_irq(&port
->lock
);
996 memcpy(&cnow
, &port
->icount
, sizeof(struct uart_icount
));
997 spin_unlock_irq(&port
->lock
);
999 icount
.cts
= cnow
.cts
;
1000 icount
.dsr
= cnow
.dsr
;
1001 icount
.rng
= cnow
.rng
;
1002 icount
.dcd
= cnow
.dcd
;
1003 icount
.rx
= cnow
.rx
;
1004 icount
.tx
= cnow
.tx
;
1005 icount
.frame
= cnow
.frame
;
1006 icount
.overrun
= cnow
.overrun
;
1007 icount
.parity
= cnow
.parity
;
1008 icount
.brk
= cnow
.brk
;
1009 icount
.buf_overrun
= cnow
.buf_overrun
;
1011 return copy_to_user(icnt
, &icount
, sizeof(icount
)) ? -EFAULT
: 0;
1015 * Called via sys_ioctl under the BKL. We can use spin_lock_irq() here.
1018 uart_ioctl(struct tty_struct
*tty
, struct file
*filp
, unsigned int cmd
,
1021 struct uart_state
*state
= tty
->driver_data
;
1022 void __user
*uarg
= (void __user
*)arg
;
1023 int ret
= -ENOIOCTLCMD
;
1025 BUG_ON(!kernel_locked());
1028 * These ioctls don't rely on the hardware to be present.
1032 ret
= uart_get_info(state
, uarg
);
1036 ret
= uart_set_info(state
, uarg
);
1040 ret
= uart_do_autoconfig(state
);
1043 case TIOCSERGWILD
: /* obsolete */
1044 case TIOCSERSWILD
: /* obsolete */
1049 if (ret
!= -ENOIOCTLCMD
)
1052 if (tty
->flags
& (1 << TTY_IO_ERROR
)) {
1058 * The following should only be used when hardware is present.
1062 ret
= uart_wait_modem_status(state
, arg
);
1066 ret
= uart_get_count(state
, uarg
);
1070 if (ret
!= -ENOIOCTLCMD
)
1075 if (tty_hung_up_p(filp
)) {
1081 * All these rely on hardware being present and need to be
1082 * protected against the tty being hung up.
1085 case TIOCSERGETLSR
: /* Get line status register */
1086 ret
= uart_get_lsr_info(state
, uarg
);
1090 struct uart_port
*port
= state
->port
;
1091 if (port
->ops
->ioctl
)
1092 ret
= port
->ops
->ioctl(port
, cmd
, arg
);
1102 static void uart_set_termios(struct tty_struct
*tty
, struct termios
*old_termios
)
1104 struct uart_state
*state
= tty
->driver_data
;
1105 unsigned long flags
;
1106 unsigned int cflag
= tty
->termios
->c_cflag
;
1108 BUG_ON(!kernel_locked());
1111 * These are the bits that are used to setup various
1112 * flags in the low level driver.
1114 #define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1116 if ((cflag
^ old_termios
->c_cflag
) == 0 &&
1117 RELEVANT_IFLAG(tty
->termios
->c_iflag
^ old_termios
->c_iflag
) == 0)
1120 uart_change_speed(state
, old_termios
);
1122 /* Handle transition to B0 status */
1123 if ((old_termios
->c_cflag
& CBAUD
) && !(cflag
& CBAUD
))
1124 uart_clear_mctrl(state
->port
, TIOCM_RTS
| TIOCM_DTR
);
1126 /* Handle transition away from B0 status */
1127 if (!(old_termios
->c_cflag
& CBAUD
) && (cflag
& CBAUD
)) {
1128 unsigned int mask
= TIOCM_DTR
;
1129 if (!(cflag
& CRTSCTS
) ||
1130 !test_bit(TTY_THROTTLED
, &tty
->flags
))
1132 uart_set_mctrl(state
->port
, mask
);
1135 /* Handle turning off CRTSCTS */
1136 if ((old_termios
->c_cflag
& CRTSCTS
) && !(cflag
& CRTSCTS
)) {
1137 spin_lock_irqsave(&state
->port
->lock
, flags
);
1138 tty
->hw_stopped
= 0;
1140 spin_unlock_irqrestore(&state
->port
->lock
, flags
);
1143 /* Handle turning on CRTSCTS */
1144 if (!(old_termios
->c_cflag
& CRTSCTS
) && (cflag
& CRTSCTS
)) {
1145 spin_lock_irqsave(&state
->port
->lock
, flags
);
1146 if (!(state
->port
->ops
->get_mctrl(state
->port
) & TIOCM_CTS
)) {
1147 tty
->hw_stopped
= 1;
1148 state
->port
->ops
->stop_tx(state
->port
);
1150 spin_unlock_irqrestore(&state
->port
->lock
, flags
);
1155 * No need to wake up processes in open wait, since they
1156 * sample the CLOCAL flag once, and don't recheck it.
1157 * XXX It's not clear whether the current behavior is correct
1158 * or not. Hence, this may change.....
1160 if (!(old_termios
->c_cflag
& CLOCAL
) &&
1161 (tty
->termios
->c_cflag
& CLOCAL
))
1162 wake_up_interruptible(&state
->info
->open_wait
);
1167 * In 2.4.5, calls to this will be serialized via the BKL in
1168 * linux/drivers/char/tty_io.c:tty_release()
1169 * linux/drivers/char/tty_io.c:do_tty_handup()
1171 static void uart_close(struct tty_struct
*tty
, struct file
*filp
)
1173 struct uart_state
*state
= tty
->driver_data
;
1174 struct uart_port
*port
;
1176 BUG_ON(!kernel_locked());
1178 if (!state
|| !state
->port
)
1183 DPRINTK("uart_close(%d) called\n", port
->line
);
1187 if (tty_hung_up_p(filp
))
1190 if ((tty
->count
== 1) && (state
->count
!= 1)) {
1192 * Uh, oh. tty->count is 1, which means that the tty
1193 * structure will be freed. state->count should always
1194 * be one in these conditions. If it's greater than
1195 * one, we've got real problems, since it means the
1196 * serial port won't be shutdown.
1198 printk(KERN_ERR
"uart_close: bad serial port count; tty->count is 1, "
1199 "state->count is %d\n", state
->count
);
1202 if (--state
->count
< 0) {
1203 printk(KERN_ERR
"uart_close: bad serial port count for %s: %d\n",
1204 tty
->name
, state
->count
);
1211 * Now we wait for the transmit buffer to clear; and we notify
1212 * the line discipline to only process XON/XOFF characters by
1213 * setting tty->closing.
1217 if (state
->closing_wait
!= USF_CLOSING_WAIT_NONE
)
1218 tty_wait_until_sent(tty
, msecs_to_jiffies(state
->closing_wait
));
1221 * At this point, we stop accepting input. To do this, we
1222 * disable the receive line status interrupts.
1224 if (state
->info
->flags
& UIF_INITIALIZED
) {
1225 unsigned long flags
;
1226 spin_lock_irqsave(&port
->lock
, flags
);
1227 port
->ops
->stop_rx(port
);
1228 spin_unlock_irqrestore(&port
->lock
, flags
);
1230 * Before we drop DTR, make sure the UART transmitter
1231 * has completely drained; this is especially
1232 * important if there is a transmit FIFO!
1234 uart_wait_until_sent(tty
, port
->timeout
);
1237 uart_shutdown(state
);
1238 uart_flush_buffer(tty
);
1240 tty_ldisc_flush(tty
);
1243 state
->info
->tty
= NULL
;
1245 if (state
->info
->blocked_open
) {
1246 if (state
->close_delay
)
1247 msleep_interruptible(state
->close_delay
);
1248 } else if (!uart_console(port
)) {
1249 uart_change_pm(state
, 3);
1253 * Wake up anyone trying to open this port.
1255 state
->info
->flags
&= ~UIF_NORMAL_ACTIVE
;
1256 wake_up_interruptible(&state
->info
->open_wait
);
1262 static void uart_wait_until_sent(struct tty_struct
*tty
, int timeout
)
1264 struct uart_state
*state
= tty
->driver_data
;
1265 struct uart_port
*port
= state
->port
;
1266 unsigned long char_time
, expire
;
1268 BUG_ON(!kernel_locked());
1270 if (port
->type
== PORT_UNKNOWN
|| port
->fifosize
== 0)
1274 * Set the check interval to be 1/5 of the estimated time to
1275 * send a single character, and make it at least 1. The check
1276 * interval should also be less than the timeout.
1278 * Note: we have to use pretty tight timings here to satisfy
1281 char_time
= (port
->timeout
- HZ
/50) / port
->fifosize
;
1282 char_time
= char_time
/ 5;
1285 if (timeout
&& timeout
< char_time
)
1286 char_time
= timeout
;
1289 * If the transmitter hasn't cleared in twice the approximate
1290 * amount of time to send the entire FIFO, it probably won't
1291 * ever clear. This assumes the UART isn't doing flow
1292 * control, which is currently the case. Hence, if it ever
1293 * takes longer than port->timeout, this is probably due to a
1294 * UART bug of some kind. So, we clamp the timeout parameter at
1297 if (timeout
== 0 || timeout
> 2 * port
->timeout
)
1298 timeout
= 2 * port
->timeout
;
1300 expire
= jiffies
+ timeout
;
1302 DPRINTK("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1303 port
->line
, jiffies
, expire
);
1306 * Check whether the transmitter is empty every 'char_time'.
1307 * 'timeout' / 'expire' give us the maximum amount of time
1310 while (!port
->ops
->tx_empty(port
)) {
1311 msleep_interruptible(jiffies_to_msecs(char_time
));
1312 if (signal_pending(current
))
1314 if (time_after(jiffies
, expire
))
1317 set_current_state(TASK_RUNNING
); /* might not be needed */
1321 * This is called with the BKL held in
1322 * linux/drivers/char/tty_io.c:do_tty_hangup()
1323 * We're called from the eventd thread, so we can sleep for
1324 * a _short_ time only.
1326 static void uart_hangup(struct tty_struct
*tty
)
1328 struct uart_state
*state
= tty
->driver_data
;
1330 BUG_ON(!kernel_locked());
1331 DPRINTK("uart_hangup(%d)\n", state
->port
->line
);
1334 if (state
->info
&& state
->info
->flags
& UIF_NORMAL_ACTIVE
) {
1335 uart_flush_buffer(tty
);
1336 uart_shutdown(state
);
1338 state
->info
->flags
&= ~UIF_NORMAL_ACTIVE
;
1339 state
->info
->tty
= NULL
;
1340 wake_up_interruptible(&state
->info
->open_wait
);
1341 wake_up_interruptible(&state
->info
->delta_msr_wait
);
1347 * Copy across the serial console cflag setting into the termios settings
1348 * for the initial open of the port. This allows continuity between the
1349 * kernel settings, and the settings init adopts when it opens the port
1350 * for the first time.
1352 static void uart_update_termios(struct uart_state
*state
)
1354 struct tty_struct
*tty
= state
->info
->tty
;
1355 struct uart_port
*port
= state
->port
;
1357 if (uart_console(port
) && port
->cons
->cflag
) {
1358 tty
->termios
->c_cflag
= port
->cons
->cflag
;
1359 port
->cons
->cflag
= 0;
1363 * If the device failed to grab its irq resources,
1364 * or some other error occurred, don't try to talk
1365 * to the port hardware.
1367 if (!(tty
->flags
& (1 << TTY_IO_ERROR
))) {
1369 * Make termios settings take effect.
1371 uart_change_speed(state
, NULL
);
1374 * And finally enable the RTS and DTR signals.
1376 if (tty
->termios
->c_cflag
& CBAUD
)
1377 uart_set_mctrl(port
, TIOCM_DTR
| TIOCM_RTS
);
1382 * Block the open until the port is ready. We must be called with
1383 * the per-port semaphore held.
1386 uart_block_til_ready(struct file
*filp
, struct uart_state
*state
)
1388 DECLARE_WAITQUEUE(wait
, current
);
1389 struct uart_info
*info
= state
->info
;
1390 struct uart_port
*port
= state
->port
;
1393 info
->blocked_open
++;
1396 add_wait_queue(&info
->open_wait
, &wait
);
1398 set_current_state(TASK_INTERRUPTIBLE
);
1401 * If we have been hung up, tell userspace/restart open.
1403 if (tty_hung_up_p(filp
) || info
->tty
== NULL
)
1407 * If the port has been closed, tell userspace/restart open.
1409 if (!(info
->flags
& UIF_INITIALIZED
))
1413 * If non-blocking mode is set, or CLOCAL mode is set,
1414 * we don't want to wait for the modem status lines to
1415 * indicate that the port is ready.
1417 * Also, if the port is not enabled/configured, we want
1418 * to allow the open to succeed here. Note that we will
1419 * have set TTY_IO_ERROR for a non-existant port.
1421 if ((filp
->f_flags
& O_NONBLOCK
) ||
1422 (info
->tty
->termios
->c_cflag
& CLOCAL
) ||
1423 (info
->tty
->flags
& (1 << TTY_IO_ERROR
))) {
1428 * Set DTR to allow modem to know we're waiting. Do
1429 * not set RTS here - we want to make sure we catch
1430 * the data from the modem.
1432 if (info
->tty
->termios
->c_cflag
& CBAUD
)
1433 uart_set_mctrl(port
, TIOCM_DTR
);
1436 * and wait for the carrier to indicate that the
1437 * modem is ready for us.
1439 spin_lock_irq(&port
->lock
);
1440 mctrl
= port
->ops
->get_mctrl(port
);
1441 spin_unlock_irq(&port
->lock
);
1442 if (mctrl
& TIOCM_CAR
)
1449 if (signal_pending(current
))
1452 set_current_state(TASK_RUNNING
);
1453 remove_wait_queue(&info
->open_wait
, &wait
);
1456 info
->blocked_open
--;
1458 if (signal_pending(current
))
1459 return -ERESTARTSYS
;
1461 if (!info
->tty
|| tty_hung_up_p(filp
))
1467 static struct uart_state
*uart_get(struct uart_driver
*drv
, int line
)
1469 struct uart_state
*state
;
1472 state
= drv
->state
+ line
;
1473 if (down_interruptible(&state
->sem
)) {
1474 state
= ERR_PTR(-ERESTARTSYS
);
1482 state
= ERR_PTR(-ENXIO
);
1487 state
->info
= kmalloc(sizeof(struct uart_info
), GFP_KERNEL
);
1489 memset(state
->info
, 0, sizeof(struct uart_info
));
1490 init_waitqueue_head(&state
->info
->open_wait
);
1491 init_waitqueue_head(&state
->info
->delta_msr_wait
);
1494 * Link the info into the other structures.
1496 state
->port
->info
= state
->info
;
1498 tasklet_init(&state
->info
->tlet
, uart_tasklet_action
,
1499 (unsigned long)state
);
1503 state
= ERR_PTR(-ENOMEM
);
1513 * In 2.4.5, calls to uart_open are serialised by the BKL in
1514 * linux/fs/devices.c:chrdev_open()
1515 * Note that if this fails, then uart_close() _will_ be called.
1517 * In time, we want to scrap the "opening nonpresent ports"
1518 * behaviour and implement an alternative way for setserial
1519 * to set base addresses/ports/types. This will allow us to
1520 * get rid of a certain amount of extra tests.
1522 static int uart_open(struct tty_struct
*tty
, struct file
*filp
)
1524 struct uart_driver
*drv
= (struct uart_driver
*)tty
->driver
->driver_state
;
1525 struct uart_state
*state
;
1526 int retval
, line
= tty
->index
;
1528 BUG_ON(!kernel_locked());
1529 DPRINTK("uart_open(%d) called\n", line
);
1532 * tty->driver->num won't change, so we won't fail here with
1533 * tty->driver_data set to something non-NULL (and therefore
1534 * we won't get caught by uart_close()).
1537 if (line
>= tty
->driver
->num
)
1541 * We take the semaphore inside uart_get to guarantee that we won't
1542 * be re-entered while allocating the info structure, or while we
1543 * request any IRQs that the driver may need. This also has the nice
1544 * side-effect that it delays the action of uart_hangup, so we can
1545 * guarantee that info->tty will always contain something reasonable.
1547 state
= uart_get(drv
, line
);
1548 if (IS_ERR(state
)) {
1549 retval
= PTR_ERR(state
);
1554 * Once we set tty->driver_data here, we are guaranteed that
1555 * uart_close() will decrement the driver module use count.
1556 * Any failures from here onwards should not touch the count.
1558 tty
->driver_data
= state
;
1559 tty
->low_latency
= (state
->port
->flags
& UPF_LOW_LATENCY
) ? 1 : 0;
1561 state
->info
->tty
= tty
;
1564 * If the port is in the middle of closing, bail out now.
1566 if (tty_hung_up_p(filp
)) {
1574 * Make sure the device is in D0 state.
1576 if (state
->count
== 1)
1577 uart_change_pm(state
, 0);
1580 * Start up the serial port.
1582 retval
= uart_startup(state
, 0);
1585 * If we succeeded, wait until the port is ready.
1588 retval
= uart_block_til_ready(filp
, state
);
1592 * If this is the first open to succeed, adjust things to suit.
1594 if (retval
== 0 && !(state
->info
->flags
& UIF_NORMAL_ACTIVE
)) {
1595 state
->info
->flags
|= UIF_NORMAL_ACTIVE
;
1597 uart_update_termios(state
);
1604 static const char *uart_type(struct uart_port
*port
)
1606 const char *str
= NULL
;
1608 if (port
->ops
->type
)
1609 str
= port
->ops
->type(port
);
1617 #ifdef CONFIG_PROC_FS
1619 static int uart_line_info(char *buf
, struct uart_driver
*drv
, int i
)
1621 struct uart_state
*state
= drv
->state
+ i
;
1622 struct uart_port
*port
= state
->port
;
1624 unsigned int status
;
1630 ret
= sprintf(buf
, "%d: uart:%s %s%08lX irq:%d",
1631 port
->line
, uart_type(port
),
1632 port
->iotype
== UPIO_MEM
? "mmio:0x" : "port:",
1633 port
->iotype
== UPIO_MEM
? port
->mapbase
:
1634 (unsigned long) port
->iobase
,
1637 if (port
->type
== PORT_UNKNOWN
) {
1642 if(capable(CAP_SYS_ADMIN
))
1644 spin_lock_irq(&port
->lock
);
1645 status
= port
->ops
->get_mctrl(port
);
1646 spin_unlock_irq(&port
->lock
);
1648 ret
+= sprintf(buf
+ ret
, " tx:%d rx:%d",
1649 port
->icount
.tx
, port
->icount
.rx
);
1650 if (port
->icount
.frame
)
1651 ret
+= sprintf(buf
+ ret
, " fe:%d",
1652 port
->icount
.frame
);
1653 if (port
->icount
.parity
)
1654 ret
+= sprintf(buf
+ ret
, " pe:%d",
1655 port
->icount
.parity
);
1656 if (port
->icount
.brk
)
1657 ret
+= sprintf(buf
+ ret
, " brk:%d",
1659 if (port
->icount
.overrun
)
1660 ret
+= sprintf(buf
+ ret
, " oe:%d",
1661 port
->icount
.overrun
);
1663 #define INFOBIT(bit,str) \
1664 if (port->mctrl & (bit)) \
1665 strncat(stat_buf, (str), sizeof(stat_buf) - \
1666 strlen(stat_buf) - 2)
1667 #define STATBIT(bit,str) \
1668 if (status & (bit)) \
1669 strncat(stat_buf, (str), sizeof(stat_buf) - \
1670 strlen(stat_buf) - 2)
1674 INFOBIT(TIOCM_RTS
, "|RTS");
1675 STATBIT(TIOCM_CTS
, "|CTS");
1676 INFOBIT(TIOCM_DTR
, "|DTR");
1677 STATBIT(TIOCM_DSR
, "|DSR");
1678 STATBIT(TIOCM_CAR
, "|CD");
1679 STATBIT(TIOCM_RNG
, "|RI");
1682 strcat(stat_buf
, "\n");
1684 ret
+= sprintf(buf
+ ret
, stat_buf
);
1694 static int uart_read_proc(char *page
, char **start
, off_t off
,
1695 int count
, int *eof
, void *data
)
1697 struct tty_driver
*ttydrv
= data
;
1698 struct uart_driver
*drv
= ttydrv
->driver_state
;
1702 len
+= sprintf(page
, "serinfo:1.0 driver%s%s revision:%s\n",
1704 for (i
= 0; i
< drv
->nr
&& len
< PAGE_SIZE
- 96; i
++) {
1705 l
= uart_line_info(page
+ len
, drv
, i
);
1707 if (len
+ begin
> off
+ count
)
1709 if (len
+ begin
< off
) {
1716 if (off
>= len
+ begin
)
1718 *start
= page
+ (off
- begin
);
1719 return (count
< begin
+ len
- off
) ? count
: (begin
+ len
- off
);
1723 #ifdef CONFIG_SERIAL_CORE_CONSOLE
1725 * Check whether an invalid uart number has been specified, and
1726 * if so, search for the first available port that does have
1729 struct uart_port
* __init
1730 uart_get_console(struct uart_port
*ports
, int nr
, struct console
*co
)
1732 int idx
= co
->index
;
1734 if (idx
< 0 || idx
>= nr
|| (ports
[idx
].iobase
== 0 &&
1735 ports
[idx
].membase
== NULL
))
1736 for (idx
= 0; idx
< nr
; idx
++)
1737 if (ports
[idx
].iobase
!= 0 ||
1738 ports
[idx
].membase
!= NULL
)
1747 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1748 * @options: pointer to option string
1749 * @baud: pointer to an 'int' variable for the baud rate.
1750 * @parity: pointer to an 'int' variable for the parity.
1751 * @bits: pointer to an 'int' variable for the number of data bits.
1752 * @flow: pointer to an 'int' variable for the flow control character.
1754 * uart_parse_options decodes a string containing the serial console
1755 * options. The format of the string is <baud><parity><bits><flow>,
1759 uart_parse_options(char *options
, int *baud
, int *parity
, int *bits
, int *flow
)
1763 *baud
= simple_strtoul(s
, NULL
, 10);
1764 while (*s
>= '0' && *s
<= '9')
1779 static struct baud_rates baud_rates
[] = {
1780 { 921600, B921600
},
1781 { 460800, B460800
},
1782 { 230400, B230400
},
1783 { 115200, B115200
},
1795 * uart_set_options - setup the serial console parameters
1796 * @port: pointer to the serial ports uart_port structure
1797 * @co: console pointer
1799 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1800 * @bits: number of data bits
1801 * @flow: flow control character - 'r' (rts)
1804 uart_set_options(struct uart_port
*port
, struct console
*co
,
1805 int baud
, int parity
, int bits
, int flow
)
1807 struct termios termios
;
1811 * Ensure that the serial console lock is initialised
1814 spin_lock_init(&port
->lock
);
1816 memset(&termios
, 0, sizeof(struct termios
));
1818 termios
.c_cflag
= CREAD
| HUPCL
| CLOCAL
;
1821 * Construct a cflag setting.
1823 for (i
= 0; baud_rates
[i
].rate
; i
++)
1824 if (baud_rates
[i
].rate
<= baud
)
1827 termios
.c_cflag
|= baud_rates
[i
].cflag
;
1830 termios
.c_cflag
|= CS7
;
1832 termios
.c_cflag
|= CS8
;
1836 termios
.c_cflag
|= PARODD
;
1839 termios
.c_cflag
|= PARENB
;
1844 termios
.c_cflag
|= CRTSCTS
;
1846 port
->ops
->set_termios(port
, &termios
, NULL
);
1847 co
->cflag
= termios
.c_cflag
;
1851 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1853 static void uart_change_pm(struct uart_state
*state
, int pm_state
)
1855 struct uart_port
*port
= state
->port
;
1857 port
->ops
->pm(port
, pm_state
, state
->pm_state
);
1858 state
->pm_state
= pm_state
;
1861 int uart_suspend_port(struct uart_driver
*drv
, struct uart_port
*port
)
1863 struct uart_state
*state
= drv
->state
+ port
->line
;
1867 if (state
->info
&& state
->info
->flags
& UIF_INITIALIZED
) {
1868 struct uart_ops
*ops
= port
->ops
;
1870 spin_lock_irq(&port
->lock
);
1872 ops
->set_mctrl(port
, 0);
1874 spin_unlock_irq(&port
->lock
);
1877 * Wait for the transmitter to empty.
1879 while (!ops
->tx_empty(port
)) {
1883 ops
->shutdown(port
);
1887 * Disable the console device before suspending.
1889 if (uart_console(port
))
1890 console_stop(port
->cons
);
1892 uart_change_pm(state
, 3);
1899 int uart_resume_port(struct uart_driver
*drv
, struct uart_port
*port
)
1901 struct uart_state
*state
= drv
->state
+ port
->line
;
1905 uart_change_pm(state
, 0);
1908 * Re-enable the console device after suspending.
1910 if (uart_console(port
)) {
1911 struct termios termios
;
1914 * First try to use the console cflag setting.
1916 memset(&termios
, 0, sizeof(struct termios
));
1917 termios
.c_cflag
= port
->cons
->cflag
;
1920 * If that's unset, use the tty termios setting.
1922 if (state
->info
&& state
->info
->tty
&& termios
.c_cflag
== 0)
1923 termios
= *state
->info
->tty
->termios
;
1925 port
->ops
->set_termios(port
, &termios
, NULL
);
1926 console_start(port
->cons
);
1929 if (state
->info
&& state
->info
->flags
& UIF_INITIALIZED
) {
1930 struct uart_ops
*ops
= port
->ops
;
1932 ops
->set_mctrl(port
, 0);
1934 uart_change_speed(state
, NULL
);
1935 spin_lock_irq(&port
->lock
);
1936 ops
->set_mctrl(port
, port
->mctrl
);
1937 ops
->start_tx(port
);
1938 spin_unlock_irq(&port
->lock
);
1947 uart_report_port(struct uart_driver
*drv
, struct uart_port
*port
)
1951 switch (port
->iotype
) {
1953 snprintf(address
, sizeof(address
),
1954 "I/O 0x%x", port
->iobase
);
1957 snprintf(address
, sizeof(address
),
1958 "I/O 0x%x offset 0x%x", port
->iobase
, port
->hub6
);
1963 snprintf(address
, sizeof(address
),
1964 "MMIO 0x%lx", port
->mapbase
);
1967 strlcpy(address
, "*unknown*", sizeof(address
));
1971 printk(KERN_INFO
"%s%s%s%d at %s (irq = %d) is a %s\n",
1972 port
->dev
? port
->dev
->bus_id
: "",
1973 port
->dev
? ": " : "",
1974 drv
->dev_name
, port
->line
, address
, port
->irq
, uart_type(port
));
1978 uart_configure_port(struct uart_driver
*drv
, struct uart_state
*state
,
1979 struct uart_port
*port
)
1984 * If there isn't a port here, don't do anything further.
1986 if (!port
->iobase
&& !port
->mapbase
&& !port
->membase
)
1990 * Now do the auto configuration stuff. Note that config_port
1991 * is expected to claim the resources and map the port for us.
1993 flags
= UART_CONFIG_TYPE
;
1994 if (port
->flags
& UPF_AUTO_IRQ
)
1995 flags
|= UART_CONFIG_IRQ
;
1996 if (port
->flags
& UPF_BOOT_AUTOCONF
) {
1997 port
->type
= PORT_UNKNOWN
;
1998 port
->ops
->config_port(port
, flags
);
2001 if (port
->type
!= PORT_UNKNOWN
) {
2002 unsigned long flags
;
2004 uart_report_port(drv
, port
);
2007 * Ensure that the modem control lines are de-activated.
2008 * We probably don't need a spinlock around this, but
2010 spin_lock_irqsave(&port
->lock
, flags
);
2011 port
->ops
->set_mctrl(port
, 0);
2012 spin_unlock_irqrestore(&port
->lock
, flags
);
2015 * Power down all ports by default, except the
2016 * console if we have one.
2018 if (!uart_console(port
))
2019 uart_change_pm(state
, 3);
2024 * This reverses the effects of uart_configure_port, hanging up the
2025 * port before removal.
2028 uart_unconfigure_port(struct uart_driver
*drv
, struct uart_state
*state
)
2030 struct uart_port
*port
= state
->port
;
2031 struct uart_info
*info
= state
->info
;
2033 if (info
&& info
->tty
)
2034 tty_vhangup(info
->tty
);
2041 * Free the port IO and memory resources, if any.
2043 if (port
->type
!= PORT_UNKNOWN
)
2044 port
->ops
->release_port(port
);
2047 * Indicate that there isn't a port here anymore.
2049 port
->type
= PORT_UNKNOWN
;
2052 * Kill the tasklet, and free resources.
2055 tasklet_kill(&info
->tlet
);
2062 static struct tty_operations uart_ops
= {
2064 .close
= uart_close
,
2065 .write
= uart_write
,
2066 .put_char
= uart_put_char
,
2067 .flush_chars
= uart_flush_chars
,
2068 .write_room
= uart_write_room
,
2069 .chars_in_buffer
= uart_chars_in_buffer
,
2070 .flush_buffer
= uart_flush_buffer
,
2071 .ioctl
= uart_ioctl
,
2072 .throttle
= uart_throttle
,
2073 .unthrottle
= uart_unthrottle
,
2074 .send_xchar
= uart_send_xchar
,
2075 .set_termios
= uart_set_termios
,
2077 .start
= uart_start
,
2078 .hangup
= uart_hangup
,
2079 .break_ctl
= uart_break_ctl
,
2080 .wait_until_sent
= uart_wait_until_sent
,
2081 #ifdef CONFIG_PROC_FS
2082 .read_proc
= uart_read_proc
,
2084 .tiocmget
= uart_tiocmget
,
2085 .tiocmset
= uart_tiocmset
,
2089 * uart_register_driver - register a driver with the uart core layer
2090 * @drv: low level driver structure
2092 * Register a uart driver with the core driver. We in turn register
2093 * with the tty layer, and initialise the core driver per-port state.
2095 * We have a proc file in /proc/tty/driver which is named after the
2098 * drv->port should be NULL, and the per-port structures should be
2099 * registered using uart_add_one_port after this call has succeeded.
2101 int uart_register_driver(struct uart_driver
*drv
)
2103 struct tty_driver
*normal
= NULL
;
2109 * Maybe we should be using a slab cache for this, especially if
2110 * we have a large number of ports to handle.
2112 drv
->state
= kmalloc(sizeof(struct uart_state
) * drv
->nr
, GFP_KERNEL
);
2117 memset(drv
->state
, 0, sizeof(struct uart_state
) * drv
->nr
);
2119 normal
= alloc_tty_driver(drv
->nr
);
2123 drv
->tty_driver
= normal
;
2125 normal
->owner
= drv
->owner
;
2126 normal
->driver_name
= drv
->driver_name
;
2127 normal
->devfs_name
= drv
->devfs_name
;
2128 normal
->name
= drv
->dev_name
;
2129 normal
->major
= drv
->major
;
2130 normal
->minor_start
= drv
->minor
;
2131 normal
->type
= TTY_DRIVER_TYPE_SERIAL
;
2132 normal
->subtype
= SERIAL_TYPE_NORMAL
;
2133 normal
->init_termios
= tty_std_termios
;
2134 normal
->init_termios
.c_cflag
= B9600
| CS8
| CREAD
| HUPCL
| CLOCAL
;
2135 normal
->flags
= TTY_DRIVER_REAL_RAW
| TTY_DRIVER_NO_DEVFS
;
2136 normal
->driver_state
= drv
;
2137 tty_set_operations(normal
, &uart_ops
);
2140 * Initialise the UART state(s).
2142 for (i
= 0; i
< drv
->nr
; i
++) {
2143 struct uart_state
*state
= drv
->state
+ i
;
2145 state
->close_delay
= 500; /* .5 seconds */
2146 state
->closing_wait
= 30000; /* 30 seconds */
2148 init_MUTEX(&state
->sem
);
2151 retval
= tty_register_driver(normal
);
2154 put_tty_driver(normal
);
2161 * uart_unregister_driver - remove a driver from the uart core layer
2162 * @drv: low level driver structure
2164 * Remove all references to a driver from the core driver. The low
2165 * level driver must have removed all its ports via the
2166 * uart_remove_one_port() if it registered them with uart_add_one_port().
2167 * (ie, drv->port == NULL)
2169 void uart_unregister_driver(struct uart_driver
*drv
)
2171 struct tty_driver
*p
= drv
->tty_driver
;
2172 tty_unregister_driver(p
);
2175 drv
->tty_driver
= NULL
;
2178 struct tty_driver
*uart_console_device(struct console
*co
, int *index
)
2180 struct uart_driver
*p
= co
->data
;
2182 return p
->tty_driver
;
2186 * uart_add_one_port - attach a driver-defined port structure
2187 * @drv: pointer to the uart low level driver structure for this port
2188 * @port: uart port structure to use for this port.
2190 * This allows the driver to register its own uart_port structure
2191 * with the core driver. The main purpose is to allow the low
2192 * level uart drivers to expand uart_port, rather than having yet
2193 * more levels of structures.
2195 int uart_add_one_port(struct uart_driver
*drv
, struct uart_port
*port
)
2197 struct uart_state
*state
;
2200 BUG_ON(in_interrupt());
2202 if (port
->line
>= drv
->nr
)
2205 state
= drv
->state
+ port
->line
;
2215 port
->cons
= drv
->cons
;
2216 port
->info
= state
->info
;
2219 * If this port is a console, then the spinlock is already
2222 if (!uart_console(port
))
2223 spin_lock_init(&port
->lock
);
2225 uart_configure_port(drv
, state
, port
);
2228 * Register the port whether it's detected or not. This allows
2229 * setserial to be used to alter this ports parameters.
2231 tty_register_device(drv
->tty_driver
, port
->line
, port
->dev
);
2234 * If this driver supports console, and it hasn't been
2235 * successfully registered yet, try to re-register it.
2236 * It may be that the port was not available.
2238 if (port
->type
!= PORT_UNKNOWN
&&
2239 port
->cons
&& !(port
->cons
->flags
& CON_ENABLED
))
2240 register_console(port
->cons
);
2249 * uart_remove_one_port - detach a driver defined port structure
2250 * @drv: pointer to the uart low level driver structure for this port
2251 * @port: uart port structure for this port
2253 * This unhooks (and hangs up) the specified port structure from the
2254 * core driver. No further calls will be made to the low-level code
2257 int uart_remove_one_port(struct uart_driver
*drv
, struct uart_port
*port
)
2259 struct uart_state
*state
= drv
->state
+ port
->line
;
2261 BUG_ON(in_interrupt());
2263 if (state
->port
!= port
)
2264 printk(KERN_ALERT
"Removing wrong port: %p != %p\n",
2270 * Remove the devices from devfs
2272 tty_unregister_device(drv
->tty_driver
, port
->line
);
2274 uart_unconfigure_port(drv
, state
);
2282 * Are the two ports equivalent?
2284 int uart_match_port(struct uart_port
*port1
, struct uart_port
*port2
)
2286 if (port1
->iotype
!= port2
->iotype
)
2289 switch (port1
->iotype
) {
2291 return (port1
->iobase
== port2
->iobase
);
2293 return (port1
->iobase
== port2
->iobase
) &&
2294 (port1
->hub6
== port2
->hub6
);
2296 return (port1
->membase
== port2
->membase
);
2300 EXPORT_SYMBOL(uart_match_port
);
2302 EXPORT_SYMBOL(uart_write_wakeup
);
2303 EXPORT_SYMBOL(uart_register_driver
);
2304 EXPORT_SYMBOL(uart_unregister_driver
);
2305 EXPORT_SYMBOL(uart_suspend_port
);
2306 EXPORT_SYMBOL(uart_resume_port
);
2307 EXPORT_SYMBOL(uart_add_one_port
);
2308 EXPORT_SYMBOL(uart_remove_one_port
);
2310 MODULE_DESCRIPTION("Serial driver core");
2311 MODULE_LICENSE("GPL");