1 // SPDX-License-Identifier: GPL-2.0+
3 * Driver core for serial ports
5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
7 * Copyright 1999 ARM Limited
8 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
10 #include <linux/module.h>
11 #include <linux/tty.h>
12 #include <linux/tty_flip.h>
13 #include <linux/slab.h>
14 #include <linux/sched/signal.h>
15 #include <linux/init.h>
16 #include <linux/console.h>
18 #include <linux/proc_fs.h>
19 #include <linux/seq_file.h>
20 #include <linux/device.h>
21 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
22 #include <linux/serial_core.h>
23 #include <linux/delay.h>
24 #include <linux/mutex.h>
26 #include <linux/irq.h>
27 #include <linux/uaccess.h>
30 * This is used to lock changes in serial line configuration.
32 static DEFINE_MUTEX(port_mutex
);
35 * lockdep: port->lock is initialized in two places, but we
36 * want only one lock-class:
38 static struct lock_class_key port_lock_key
;
40 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
42 static void uart_change_speed(struct tty_struct
*tty
, struct uart_state
*state
,
43 struct ktermios
*old_termios
);
44 static void uart_wait_until_sent(struct tty_struct
*tty
, int timeout
);
45 static void uart_change_pm(struct uart_state
*state
,
46 enum uart_pm_state pm_state
);
48 static void uart_port_shutdown(struct tty_port
*port
);
50 static int uart_dcd_enabled(struct uart_port
*uport
)
52 return !!(uport
->status
& UPSTAT_DCD_ENABLE
);
55 static inline struct uart_port
*uart_port_ref(struct uart_state
*state
)
57 if (atomic_add_unless(&state
->refcount
, 1, 0))
58 return state
->uart_port
;
62 static inline void uart_port_deref(struct uart_port
*uport
)
64 if (atomic_dec_and_test(&uport
->state
->refcount
))
65 wake_up(&uport
->state
->remove_wait
);
68 #define uart_port_lock(state, flags) \
70 struct uart_port *__uport = uart_port_ref(state); \
72 spin_lock_irqsave(&__uport->lock, flags); \
76 #define uart_port_unlock(uport, flags) \
78 struct uart_port *__uport = uport; \
80 spin_unlock_irqrestore(&__uport->lock, flags); \
81 uart_port_deref(__uport); \
85 static inline struct uart_port
*uart_port_check(struct uart_state
*state
)
87 lockdep_assert_held(&state
->port
.mutex
);
88 return state
->uart_port
;
92 * This routine is used by the interrupt handler to schedule processing in
93 * the software interrupt portion of the driver.
95 void uart_write_wakeup(struct uart_port
*port
)
97 struct uart_state
*state
= port
->state
;
99 * This means you called this function _after_ the port was
100 * closed. No cookie for you.
103 tty_port_tty_wakeup(&state
->port
);
106 static void uart_stop(struct tty_struct
*tty
)
108 struct uart_state
*state
= tty
->driver_data
;
109 struct uart_port
*port
;
112 port
= uart_port_lock(state
, flags
);
114 port
->ops
->stop_tx(port
);
115 uart_port_unlock(port
, flags
);
118 static void __uart_start(struct tty_struct
*tty
)
120 struct uart_state
*state
= tty
->driver_data
;
121 struct uart_port
*port
= state
->uart_port
;
123 if (port
&& !uart_tx_stopped(port
))
124 port
->ops
->start_tx(port
);
127 static void uart_start(struct tty_struct
*tty
)
129 struct uart_state
*state
= tty
->driver_data
;
130 struct uart_port
*port
;
133 port
= uart_port_lock(state
, flags
);
135 uart_port_unlock(port
, flags
);
139 uart_update_mctrl(struct uart_port
*port
, unsigned int set
, unsigned int clear
)
144 spin_lock_irqsave(&port
->lock
, flags
);
146 port
->mctrl
= (old
& ~clear
) | set
;
147 if (old
!= port
->mctrl
)
148 port
->ops
->set_mctrl(port
, port
->mctrl
);
149 spin_unlock_irqrestore(&port
->lock
, flags
);
152 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
153 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
155 static void uart_port_dtr_rts(struct uart_port
*uport
, int raise
)
157 int rs485_on
= uport
->rs485_config
&&
158 (uport
->rs485
.flags
& SER_RS485_ENABLED
);
159 int RTS_after_send
= !!(uport
->rs485
.flags
& SER_RS485_RTS_AFTER_SEND
);
162 if (rs485_on
&& !RTS_after_send
) {
163 uart_set_mctrl(uport
, TIOCM_DTR
);
164 uart_clear_mctrl(uport
, TIOCM_RTS
);
166 uart_set_mctrl(uport
, TIOCM_DTR
| TIOCM_RTS
);
169 unsigned int clear
= TIOCM_DTR
;
171 clear
|= (!rs485_on
|| !RTS_after_send
) ? TIOCM_RTS
: 0;
172 uart_clear_mctrl(uport
, clear
);
177 * Startup the port. This will be called once per open. All calls
178 * will be serialised by the per-port mutex.
180 static int uart_port_startup(struct tty_struct
*tty
, struct uart_state
*state
,
183 struct uart_port
*uport
= uart_port_check(state
);
185 unsigned long flags
= 0;
188 if (uport
->type
== PORT_UNKNOWN
)
192 * Make sure the device is in D0 state.
194 uart_change_pm(state
, UART_PM_STATE_ON
);
197 * Initialise and allocate the transmit and temporary
200 page
= get_zeroed_page(GFP_KERNEL
);
204 uart_port_lock(state
, flags
);
205 if (!state
->xmit
.buf
) {
206 state
->xmit
.buf
= (unsigned char *) page
;
207 uart_circ_clear(&state
->xmit
);
208 uart_port_unlock(uport
, flags
);
210 uart_port_unlock(uport
, flags
);
212 * Do not free() the page under the port lock, see
218 retval
= uport
->ops
->startup(uport
);
220 if (uart_console(uport
) && uport
->cons
->cflag
) {
221 tty
->termios
.c_cflag
= uport
->cons
->cflag
;
222 uport
->cons
->cflag
= 0;
225 * Initialise the hardware port settings.
227 uart_change_speed(tty
, state
, NULL
);
230 * Setup the RTS and DTR signals once the
231 * port is open and ready to respond.
233 if (init_hw
&& C_BAUD(tty
))
234 uart_port_dtr_rts(uport
, 1);
238 * This is to allow setserial on this port. People may want to set
239 * port/irq/type and then reconfigure the port properly if it failed
242 if (retval
&& capable(CAP_SYS_ADMIN
))
248 static int uart_startup(struct tty_struct
*tty
, struct uart_state
*state
,
251 struct tty_port
*port
= &state
->port
;
254 if (tty_port_initialized(port
))
257 retval
= uart_port_startup(tty
, state
, init_hw
);
259 set_bit(TTY_IO_ERROR
, &tty
->flags
);
265 * This routine will shutdown a serial port; interrupts are disabled, and
266 * DTR is dropped if the hangup on close termio flag is on. Calls to
267 * uart_shutdown are serialised by the per-port semaphore.
269 * uport == NULL if uart_port has already been removed
271 static void uart_shutdown(struct tty_struct
*tty
, struct uart_state
*state
)
273 struct uart_port
*uport
= uart_port_check(state
);
274 struct tty_port
*port
= &state
->port
;
275 unsigned long flags
= 0;
276 char *xmit_buf
= NULL
;
279 * Set the TTY IO error marker
282 set_bit(TTY_IO_ERROR
, &tty
->flags
);
284 if (tty_port_initialized(port
)) {
285 tty_port_set_initialized(port
, 0);
288 * Turn off DTR and RTS early.
290 if (uport
&& uart_console(uport
) && tty
)
291 uport
->cons
->cflag
= tty
->termios
.c_cflag
;
293 if (!tty
|| C_HUPCL(tty
))
294 uart_port_dtr_rts(uport
, 0);
296 uart_port_shutdown(port
);
300 * It's possible for shutdown to be called after suspend if we get
301 * a DCD drop (hangup) at just the right time. Clear suspended bit so
302 * we don't try to resume a port that has been shutdown.
304 tty_port_set_suspended(port
, 0);
307 * Do not free() the transmit buffer page under the port lock since
308 * this can create various circular locking scenarios. For instance,
309 * console driver may need to allocate/free a debug object, which
310 * can endup in printk() recursion.
312 uart_port_lock(state
, flags
);
313 xmit_buf
= state
->xmit
.buf
;
314 state
->xmit
.buf
= NULL
;
315 uart_port_unlock(uport
, flags
);
318 free_page((unsigned long)xmit_buf
);
322 * uart_update_timeout - update per-port FIFO timeout.
323 * @port: uart_port structure describing the port
324 * @cflag: termios cflag value
325 * @baud: speed of the port
327 * Set the port FIFO timeout value. The @cflag value should
328 * reflect the actual hardware settings.
331 uart_update_timeout(struct uart_port
*port
, unsigned int cflag
,
336 /* byte size and parity */
337 switch (cflag
& CSIZE
) {
358 * The total number of bits to be transmitted in the fifo.
360 bits
= bits
* port
->fifosize
;
363 * Figure the timeout to send the above number of bits.
364 * Add .02 seconds of slop
366 port
->timeout
= (HZ
* bits
) / baud
+ HZ
/50;
369 EXPORT_SYMBOL(uart_update_timeout
);
372 * uart_get_baud_rate - return baud rate for a particular port
373 * @port: uart_port structure describing the port in question.
374 * @termios: desired termios settings.
375 * @old: old termios (or NULL)
376 * @min: minimum acceptable baud rate
377 * @max: maximum acceptable baud rate
379 * Decode the termios structure into a numeric baud rate,
380 * taking account of the magic 38400 baud rate (with spd_*
381 * flags), and mapping the %B0 rate to 9600 baud.
383 * If the new baud rate is invalid, try the old termios setting.
384 * If it's still invalid, we try 9600 baud.
386 * Update the @termios structure to reflect the baud rate
387 * we're actually going to be using. Don't do this for the case
388 * where B0 is requested ("hang up").
391 uart_get_baud_rate(struct uart_port
*port
, struct ktermios
*termios
,
392 struct ktermios
*old
, unsigned int min
, unsigned int max
)
396 unsigned int altbaud
;
398 upf_t flags
= port
->flags
& UPF_SPD_MASK
;
418 for (try = 0; try < 2; try++) {
419 baud
= tty_termios_baud_rate(termios
);
422 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
425 if (try == 0 && baud
== 38400)
429 * Special case: B0 rate.
436 if (baud
>= min
&& baud
<= max
)
440 * Oops, the quotient was zero. Try again with
441 * the old baud rate if possible.
443 termios
->c_cflag
&= ~CBAUD
;
445 baud
= tty_termios_baud_rate(old
);
447 tty_termios_encode_baud_rate(termios
,
454 * As a last resort, if the range cannot be met then clip to
455 * the nearest chip supported rate.
459 tty_termios_encode_baud_rate(termios
,
462 tty_termios_encode_baud_rate(termios
,
466 /* Should never happen */
471 EXPORT_SYMBOL(uart_get_baud_rate
);
474 * uart_get_divisor - return uart clock divisor
475 * @port: uart_port structure describing the port.
476 * @baud: desired baud rate
478 * Calculate the uart clock divisor for the port.
481 uart_get_divisor(struct uart_port
*port
, unsigned int baud
)
486 * Old custom speed handling.
488 if (baud
== 38400 && (port
->flags
& UPF_SPD_MASK
) == UPF_SPD_CUST
)
489 quot
= port
->custom_divisor
;
491 quot
= DIV_ROUND_CLOSEST(port
->uartclk
, 16 * baud
);
496 EXPORT_SYMBOL(uart_get_divisor
);
498 /* Caller holds port mutex */
499 static void uart_change_speed(struct tty_struct
*tty
, struct uart_state
*state
,
500 struct ktermios
*old_termios
)
502 struct uart_port
*uport
= uart_port_check(state
);
503 struct ktermios
*termios
;
507 * If we have no tty, termios, or the port does not exist,
508 * then we can't set the parameters for this port.
510 if (!tty
|| uport
->type
== PORT_UNKNOWN
)
513 termios
= &tty
->termios
;
514 uport
->ops
->set_termios(uport
, termios
, old_termios
);
517 * Set modem status enables based on termios cflag
519 spin_lock_irq(&uport
->lock
);
520 if (termios
->c_cflag
& CRTSCTS
)
521 uport
->status
|= UPSTAT_CTS_ENABLE
;
523 uport
->status
&= ~UPSTAT_CTS_ENABLE
;
525 if (termios
->c_cflag
& CLOCAL
)
526 uport
->status
&= ~UPSTAT_DCD_ENABLE
;
528 uport
->status
|= UPSTAT_DCD_ENABLE
;
530 /* reset sw-assisted CTS flow control based on (possibly) new mode */
531 hw_stopped
= uport
->hw_stopped
;
532 uport
->hw_stopped
= uart_softcts_mode(uport
) &&
533 !(uport
->ops
->get_mctrl(uport
) & TIOCM_CTS
);
534 if (uport
->hw_stopped
) {
536 uport
->ops
->stop_tx(uport
);
541 spin_unlock_irq(&uport
->lock
);
544 static int uart_put_char(struct tty_struct
*tty
, unsigned char c
)
546 struct uart_state
*state
= tty
->driver_data
;
547 struct uart_port
*port
;
548 struct circ_buf
*circ
;
556 port
= uart_port_lock(state
, flags
);
557 if (port
&& uart_circ_chars_free(circ
) != 0) {
558 circ
->buf
[circ
->head
] = c
;
559 circ
->head
= (circ
->head
+ 1) & (UART_XMIT_SIZE
- 1);
562 uart_port_unlock(port
, flags
);
566 static void uart_flush_chars(struct tty_struct
*tty
)
571 static int uart_write(struct tty_struct
*tty
,
572 const unsigned char *buf
, int count
)
574 struct uart_state
*state
= tty
->driver_data
;
575 struct uart_port
*port
;
576 struct circ_buf
*circ
;
581 * This means you called this function _after_ the port was
582 * closed. No cookie for you.
593 port
= uart_port_lock(state
, flags
);
595 c
= CIRC_SPACE_TO_END(circ
->head
, circ
->tail
, UART_XMIT_SIZE
);
600 memcpy(circ
->buf
+ circ
->head
, buf
, c
);
601 circ
->head
= (circ
->head
+ c
) & (UART_XMIT_SIZE
- 1);
608 uart_port_unlock(port
, flags
);
612 static int uart_write_room(struct tty_struct
*tty
)
614 struct uart_state
*state
= tty
->driver_data
;
615 struct uart_port
*port
;
619 port
= uart_port_lock(state
, flags
);
620 ret
= uart_circ_chars_free(&state
->xmit
);
621 uart_port_unlock(port
, flags
);
625 static int uart_chars_in_buffer(struct tty_struct
*tty
)
627 struct uart_state
*state
= tty
->driver_data
;
628 struct uart_port
*port
;
632 port
= uart_port_lock(state
, flags
);
633 ret
= uart_circ_chars_pending(&state
->xmit
);
634 uart_port_unlock(port
, flags
);
638 static void uart_flush_buffer(struct tty_struct
*tty
)
640 struct uart_state
*state
= tty
->driver_data
;
641 struct uart_port
*port
;
645 * This means you called this function _after_ the port was
646 * closed. No cookie for you.
653 pr_debug("uart_flush_buffer(%d) called\n", tty
->index
);
655 port
= uart_port_lock(state
, flags
);
658 uart_circ_clear(&state
->xmit
);
659 if (port
->ops
->flush_buffer
)
660 port
->ops
->flush_buffer(port
);
661 uart_port_unlock(port
, flags
);
662 tty_port_tty_wakeup(&state
->port
);
666 * This function is used to send a high-priority XON/XOFF character to
669 static void uart_send_xchar(struct tty_struct
*tty
, char ch
)
671 struct uart_state
*state
= tty
->driver_data
;
672 struct uart_port
*port
;
675 port
= uart_port_ref(state
);
679 if (port
->ops
->send_xchar
)
680 port
->ops
->send_xchar(port
, ch
);
682 spin_lock_irqsave(&port
->lock
, flags
);
685 port
->ops
->start_tx(port
);
686 spin_unlock_irqrestore(&port
->lock
, flags
);
688 uart_port_deref(port
);
691 static void uart_throttle(struct tty_struct
*tty
)
693 struct uart_state
*state
= tty
->driver_data
;
694 upstat_t mask
= UPSTAT_SYNC_FIFO
;
695 struct uart_port
*port
;
697 port
= uart_port_ref(state
);
702 mask
|= UPSTAT_AUTOXOFF
;
704 mask
|= UPSTAT_AUTORTS
;
706 if (port
->status
& mask
) {
707 port
->ops
->throttle(port
);
708 mask
&= ~port
->status
;
711 if (mask
& UPSTAT_AUTORTS
)
712 uart_clear_mctrl(port
, TIOCM_RTS
);
714 if (mask
& UPSTAT_AUTOXOFF
)
715 uart_send_xchar(tty
, STOP_CHAR(tty
));
717 uart_port_deref(port
);
720 static void uart_unthrottle(struct tty_struct
*tty
)
722 struct uart_state
*state
= tty
->driver_data
;
723 upstat_t mask
= UPSTAT_SYNC_FIFO
;
724 struct uart_port
*port
;
726 port
= uart_port_ref(state
);
731 mask
|= UPSTAT_AUTOXOFF
;
733 mask
|= UPSTAT_AUTORTS
;
735 if (port
->status
& mask
) {
736 port
->ops
->unthrottle(port
);
737 mask
&= ~port
->status
;
740 if (mask
& UPSTAT_AUTORTS
)
741 uart_set_mctrl(port
, TIOCM_RTS
);
743 if (mask
& UPSTAT_AUTOXOFF
)
744 uart_send_xchar(tty
, START_CHAR(tty
));
746 uart_port_deref(port
);
749 static int uart_get_info(struct tty_port
*port
, struct serial_struct
*retinfo
)
751 struct uart_state
*state
= container_of(port
, struct uart_state
, port
);
752 struct uart_port
*uport
;
755 memset(retinfo
, 0, sizeof(*retinfo
));
758 * Ensure the state we copy is consistent and no hardware changes
761 mutex_lock(&port
->mutex
);
762 uport
= uart_port_check(state
);
766 retinfo
->type
= uport
->type
;
767 retinfo
->line
= uport
->line
;
768 retinfo
->port
= uport
->iobase
;
769 if (HIGH_BITS_OFFSET
)
770 retinfo
->port_high
= (long) uport
->iobase
>> HIGH_BITS_OFFSET
;
771 retinfo
->irq
= uport
->irq
;
772 retinfo
->flags
= (__force
int)uport
->flags
;
773 retinfo
->xmit_fifo_size
= uport
->fifosize
;
774 retinfo
->baud_base
= uport
->uartclk
/ 16;
775 retinfo
->close_delay
= jiffies_to_msecs(port
->close_delay
) / 10;
776 retinfo
->closing_wait
= port
->closing_wait
== ASYNC_CLOSING_WAIT_NONE
?
777 ASYNC_CLOSING_WAIT_NONE
:
778 jiffies_to_msecs(port
->closing_wait
) / 10;
779 retinfo
->custom_divisor
= uport
->custom_divisor
;
780 retinfo
->hub6
= uport
->hub6
;
781 retinfo
->io_type
= uport
->iotype
;
782 retinfo
->iomem_reg_shift
= uport
->regshift
;
783 retinfo
->iomem_base
= (void *)(unsigned long)uport
->mapbase
;
787 mutex_unlock(&port
->mutex
);
791 static int uart_get_info_user(struct tty_struct
*tty
,
792 struct serial_struct
*ss
)
794 struct uart_state
*state
= tty
->driver_data
;
795 struct tty_port
*port
= &state
->port
;
797 return uart_get_info(port
, ss
) < 0 ? -EIO
: 0;
800 static int uart_set_info(struct tty_struct
*tty
, struct tty_port
*port
,
801 struct uart_state
*state
,
802 struct serial_struct
*new_info
)
804 struct uart_port
*uport
= uart_port_check(state
);
805 unsigned long new_port
;
806 unsigned int change_irq
, change_port
, closing_wait
;
807 unsigned int old_custom_divisor
, close_delay
;
808 upf_t old_flags
, new_flags
;
814 new_port
= new_info
->port
;
815 if (HIGH_BITS_OFFSET
)
816 new_port
+= (unsigned long) new_info
->port_high
<< HIGH_BITS_OFFSET
;
818 new_info
->irq
= irq_canonicalize(new_info
->irq
);
819 close_delay
= msecs_to_jiffies(new_info
->close_delay
* 10);
820 closing_wait
= new_info
->closing_wait
== ASYNC_CLOSING_WAIT_NONE
?
821 ASYNC_CLOSING_WAIT_NONE
:
822 msecs_to_jiffies(new_info
->closing_wait
* 10);
825 change_irq
= !(uport
->flags
& UPF_FIXED_PORT
)
826 && new_info
->irq
!= uport
->irq
;
829 * Since changing the 'type' of the port changes its resource
830 * allocations, we should treat type changes the same as
833 change_port
= !(uport
->flags
& UPF_FIXED_PORT
)
834 && (new_port
!= uport
->iobase
||
835 (unsigned long)new_info
->iomem_base
!= uport
->mapbase
||
836 new_info
->hub6
!= uport
->hub6
||
837 new_info
->io_type
!= uport
->iotype
||
838 new_info
->iomem_reg_shift
!= uport
->regshift
||
839 new_info
->type
!= uport
->type
);
841 old_flags
= uport
->flags
;
842 new_flags
= (__force upf_t
)new_info
->flags
;
843 old_custom_divisor
= uport
->custom_divisor
;
845 if (!capable(CAP_SYS_ADMIN
)) {
847 if (change_irq
|| change_port
||
848 (new_info
->baud_base
!= uport
->uartclk
/ 16) ||
849 (close_delay
!= port
->close_delay
) ||
850 (closing_wait
!= port
->closing_wait
) ||
851 (new_info
->xmit_fifo_size
&&
852 new_info
->xmit_fifo_size
!= uport
->fifosize
) ||
853 (((new_flags
^ old_flags
) & ~UPF_USR_MASK
) != 0))
855 uport
->flags
= ((uport
->flags
& ~UPF_USR_MASK
) |
856 (new_flags
& UPF_USR_MASK
));
857 uport
->custom_divisor
= new_info
->custom_divisor
;
862 * Ask the low level driver to verify the settings.
864 if (uport
->ops
->verify_port
)
865 retval
= uport
->ops
->verify_port(uport
, new_info
);
867 if ((new_info
->irq
>= nr_irqs
) || (new_info
->irq
< 0) ||
868 (new_info
->baud_base
< 9600))
874 if (change_port
|| change_irq
) {
878 * Make sure that we are the sole user of this port.
880 if (tty_port_users(port
) > 1)
884 * We need to shutdown the serial port at the old
885 * port/type/irq combination.
887 uart_shutdown(tty
, state
);
891 unsigned long old_iobase
, old_mapbase
;
892 unsigned int old_type
, old_iotype
, old_hub6
, old_shift
;
894 old_iobase
= uport
->iobase
;
895 old_mapbase
= uport
->mapbase
;
896 old_type
= uport
->type
;
897 old_hub6
= uport
->hub6
;
898 old_iotype
= uport
->iotype
;
899 old_shift
= uport
->regshift
;
902 * Free and release old regions
904 if (old_type
!= PORT_UNKNOWN
&& uport
->ops
->release_port
)
905 uport
->ops
->release_port(uport
);
907 uport
->iobase
= new_port
;
908 uport
->type
= new_info
->type
;
909 uport
->hub6
= new_info
->hub6
;
910 uport
->iotype
= new_info
->io_type
;
911 uport
->regshift
= new_info
->iomem_reg_shift
;
912 uport
->mapbase
= (unsigned long)new_info
->iomem_base
;
915 * Claim and map the new regions
917 if (uport
->type
!= PORT_UNKNOWN
&& uport
->ops
->request_port
) {
918 retval
= uport
->ops
->request_port(uport
);
920 /* Always success - Jean II */
925 * If we fail to request resources for the
926 * new port, try to restore the old settings.
929 uport
->iobase
= old_iobase
;
930 uport
->type
= old_type
;
931 uport
->hub6
= old_hub6
;
932 uport
->iotype
= old_iotype
;
933 uport
->regshift
= old_shift
;
934 uport
->mapbase
= old_mapbase
;
936 if (old_type
!= PORT_UNKNOWN
) {
937 retval
= uport
->ops
->request_port(uport
);
939 * If we failed to restore the old settings,
943 uport
->type
= PORT_UNKNOWN
;
951 /* Added to return the correct error -Ram Gupta */
957 uport
->irq
= new_info
->irq
;
958 if (!(uport
->flags
& UPF_FIXED_PORT
))
959 uport
->uartclk
= new_info
->baud_base
* 16;
960 uport
->flags
= (uport
->flags
& ~UPF_CHANGE_MASK
) |
961 (new_flags
& UPF_CHANGE_MASK
);
962 uport
->custom_divisor
= new_info
->custom_divisor
;
963 port
->close_delay
= close_delay
;
964 port
->closing_wait
= closing_wait
;
965 if (new_info
->xmit_fifo_size
)
966 uport
->fifosize
= new_info
->xmit_fifo_size
;
967 port
->low_latency
= (uport
->flags
& UPF_LOW_LATENCY
) ? 1 : 0;
971 if (uport
->type
== PORT_UNKNOWN
)
973 if (tty_port_initialized(port
)) {
974 if (((old_flags
^ uport
->flags
) & UPF_SPD_MASK
) ||
975 old_custom_divisor
!= uport
->custom_divisor
) {
977 * If they're setting up a custom divisor or speed,
978 * instead of clearing it, then bitch about it.
980 if (uport
->flags
& UPF_SPD_MASK
) {
981 dev_notice_ratelimited(uport
->dev
,
982 "%s sets custom speed on %s. This is deprecated.\n",
984 tty_name(port
->tty
));
986 uart_change_speed(tty
, state
, NULL
);
989 retval
= uart_startup(tty
, state
, 1);
991 tty_port_set_initialized(port
, true);
999 static int uart_set_info_user(struct tty_struct
*tty
, struct serial_struct
*ss
)
1001 struct uart_state
*state
= tty
->driver_data
;
1002 struct tty_port
*port
= &state
->port
;
1005 down_write(&tty
->termios_rwsem
);
1007 * This semaphore protects port->count. It is also
1008 * very useful to prevent opens. Also, take the
1009 * port configuration semaphore to make sure that a
1010 * module insertion/removal doesn't change anything
1013 mutex_lock(&port
->mutex
);
1014 retval
= uart_set_info(tty
, port
, state
, ss
);
1015 mutex_unlock(&port
->mutex
);
1016 up_write(&tty
->termios_rwsem
);
1021 * uart_get_lsr_info - get line status register info
1022 * @tty: tty associated with the UART
1023 * @state: UART being queried
1024 * @value: returned modem value
1026 static int uart_get_lsr_info(struct tty_struct
*tty
,
1027 struct uart_state
*state
, unsigned int __user
*value
)
1029 struct uart_port
*uport
= uart_port_check(state
);
1030 unsigned int result
;
1032 result
= uport
->ops
->tx_empty(uport
);
1035 * If we're about to load something into the transmit
1036 * register, we'll pretend the transmitter isn't empty to
1037 * avoid a race condition (depending on when the transmit
1038 * interrupt happens).
1040 if (uport
->x_char
||
1041 ((uart_circ_chars_pending(&state
->xmit
) > 0) &&
1042 !uart_tx_stopped(uport
)))
1043 result
&= ~TIOCSER_TEMT
;
1045 return put_user(result
, value
);
1048 static int uart_tiocmget(struct tty_struct
*tty
)
1050 struct uart_state
*state
= tty
->driver_data
;
1051 struct tty_port
*port
= &state
->port
;
1052 struct uart_port
*uport
;
1055 mutex_lock(&port
->mutex
);
1056 uport
= uart_port_check(state
);
1060 if (!tty_io_error(tty
)) {
1061 result
= uport
->mctrl
;
1062 spin_lock_irq(&uport
->lock
);
1063 result
|= uport
->ops
->get_mctrl(uport
);
1064 spin_unlock_irq(&uport
->lock
);
1067 mutex_unlock(&port
->mutex
);
1072 uart_tiocmset(struct tty_struct
*tty
, unsigned int set
, unsigned int clear
)
1074 struct uart_state
*state
= tty
->driver_data
;
1075 struct tty_port
*port
= &state
->port
;
1076 struct uart_port
*uport
;
1079 mutex_lock(&port
->mutex
);
1080 uport
= uart_port_check(state
);
1084 if (!tty_io_error(tty
)) {
1085 uart_update_mctrl(uport
, set
, clear
);
1089 mutex_unlock(&port
->mutex
);
1093 static int uart_break_ctl(struct tty_struct
*tty
, int break_state
)
1095 struct uart_state
*state
= tty
->driver_data
;
1096 struct tty_port
*port
= &state
->port
;
1097 struct uart_port
*uport
;
1100 mutex_lock(&port
->mutex
);
1101 uport
= uart_port_check(state
);
1105 if (uport
->type
!= PORT_UNKNOWN
)
1106 uport
->ops
->break_ctl(uport
, break_state
);
1109 mutex_unlock(&port
->mutex
);
1113 static int uart_do_autoconfig(struct tty_struct
*tty
,struct uart_state
*state
)
1115 struct tty_port
*port
= &state
->port
;
1116 struct uart_port
*uport
;
1119 if (!capable(CAP_SYS_ADMIN
))
1123 * Take the per-port semaphore. This prevents count from
1124 * changing, and hence any extra opens of the port while
1125 * we're auto-configuring.
1127 if (mutex_lock_interruptible(&port
->mutex
))
1128 return -ERESTARTSYS
;
1130 uport
= uart_port_check(state
);
1137 if (tty_port_users(port
) == 1) {
1138 uart_shutdown(tty
, state
);
1141 * If we already have a port type configured,
1142 * we must release its resources.
1144 if (uport
->type
!= PORT_UNKNOWN
&& uport
->ops
->release_port
)
1145 uport
->ops
->release_port(uport
);
1147 flags
= UART_CONFIG_TYPE
;
1148 if (uport
->flags
& UPF_AUTO_IRQ
)
1149 flags
|= UART_CONFIG_IRQ
;
1152 * This will claim the ports resources if
1155 uport
->ops
->config_port(uport
, flags
);
1157 ret
= uart_startup(tty
, state
, 1);
1159 tty_port_set_initialized(port
, true);
1164 mutex_unlock(&port
->mutex
);
1168 static void uart_enable_ms(struct uart_port
*uport
)
1171 * Force modem status interrupts on
1173 if (uport
->ops
->enable_ms
)
1174 uport
->ops
->enable_ms(uport
);
1178 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1179 * - mask passed in arg for lines of interest
1180 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1181 * Caller should use TIOCGICOUNT to see which one it was
1183 * FIXME: This wants extracting into a common all driver implementation
1184 * of TIOCMWAIT using tty_port.
1186 static int uart_wait_modem_status(struct uart_state
*state
, unsigned long arg
)
1188 struct uart_port
*uport
;
1189 struct tty_port
*port
= &state
->port
;
1190 DECLARE_WAITQUEUE(wait
, current
);
1191 struct uart_icount cprev
, cnow
;
1195 * note the counters on entry
1197 uport
= uart_port_ref(state
);
1200 spin_lock_irq(&uport
->lock
);
1201 memcpy(&cprev
, &uport
->icount
, sizeof(struct uart_icount
));
1202 uart_enable_ms(uport
);
1203 spin_unlock_irq(&uport
->lock
);
1205 add_wait_queue(&port
->delta_msr_wait
, &wait
);
1207 spin_lock_irq(&uport
->lock
);
1208 memcpy(&cnow
, &uport
->icount
, sizeof(struct uart_icount
));
1209 spin_unlock_irq(&uport
->lock
);
1211 set_current_state(TASK_INTERRUPTIBLE
);
1213 if (((arg
& TIOCM_RNG
) && (cnow
.rng
!= cprev
.rng
)) ||
1214 ((arg
& TIOCM_DSR
) && (cnow
.dsr
!= cprev
.dsr
)) ||
1215 ((arg
& TIOCM_CD
) && (cnow
.dcd
!= cprev
.dcd
)) ||
1216 ((arg
& TIOCM_CTS
) && (cnow
.cts
!= cprev
.cts
))) {
1223 /* see if a signal did it */
1224 if (signal_pending(current
)) {
1231 __set_current_state(TASK_RUNNING
);
1232 remove_wait_queue(&port
->delta_msr_wait
, &wait
);
1233 uart_port_deref(uport
);
1239 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1240 * Return: write counters to the user passed counter struct
1241 * NB: both 1->0 and 0->1 transitions are counted except for
1242 * RI where only 0->1 is counted.
1244 static int uart_get_icount(struct tty_struct
*tty
,
1245 struct serial_icounter_struct
*icount
)
1247 struct uart_state
*state
= tty
->driver_data
;
1248 struct uart_icount cnow
;
1249 struct uart_port
*uport
;
1251 uport
= uart_port_ref(state
);
1254 spin_lock_irq(&uport
->lock
);
1255 memcpy(&cnow
, &uport
->icount
, sizeof(struct uart_icount
));
1256 spin_unlock_irq(&uport
->lock
);
1257 uart_port_deref(uport
);
1259 icount
->cts
= cnow
.cts
;
1260 icount
->dsr
= cnow
.dsr
;
1261 icount
->rng
= cnow
.rng
;
1262 icount
->dcd
= cnow
.dcd
;
1263 icount
->rx
= cnow
.rx
;
1264 icount
->tx
= cnow
.tx
;
1265 icount
->frame
= cnow
.frame
;
1266 icount
->overrun
= cnow
.overrun
;
1267 icount
->parity
= cnow
.parity
;
1268 icount
->brk
= cnow
.brk
;
1269 icount
->buf_overrun
= cnow
.buf_overrun
;
1274 static int uart_get_rs485_config(struct uart_port
*port
,
1275 struct serial_rs485 __user
*rs485
)
1277 unsigned long flags
;
1278 struct serial_rs485 aux
;
1280 spin_lock_irqsave(&port
->lock
, flags
);
1282 spin_unlock_irqrestore(&port
->lock
, flags
);
1284 if (copy_to_user(rs485
, &aux
, sizeof(aux
)))
1290 static int uart_set_rs485_config(struct uart_port
*port
,
1291 struct serial_rs485 __user
*rs485_user
)
1293 struct serial_rs485 rs485
;
1295 unsigned long flags
;
1297 if (!port
->rs485_config
)
1298 return -ENOIOCTLCMD
;
1300 if (copy_from_user(&rs485
, rs485_user
, sizeof(*rs485_user
)))
1303 spin_lock_irqsave(&port
->lock
, flags
);
1304 ret
= port
->rs485_config(port
, &rs485
);
1305 spin_unlock_irqrestore(&port
->lock
, flags
);
1309 if (copy_to_user(rs485_user
, &port
->rs485
, sizeof(port
->rs485
)))
1315 static int uart_get_iso7816_config(struct uart_port
*port
,
1316 struct serial_iso7816 __user
*iso7816
)
1318 unsigned long flags
;
1319 struct serial_iso7816 aux
;
1321 if (!port
->iso7816_config
)
1322 return -ENOIOCTLCMD
;
1324 spin_lock_irqsave(&port
->lock
, flags
);
1325 aux
= port
->iso7816
;
1326 spin_unlock_irqrestore(&port
->lock
, flags
);
1328 if (copy_to_user(iso7816
, &aux
, sizeof(aux
)))
1334 static int uart_set_iso7816_config(struct uart_port
*port
,
1335 struct serial_iso7816 __user
*iso7816_user
)
1337 struct serial_iso7816 iso7816
;
1339 unsigned long flags
;
1341 if (!port
->iso7816_config
)
1342 return -ENOIOCTLCMD
;
1344 if (copy_from_user(&iso7816
, iso7816_user
, sizeof(*iso7816_user
)))
1348 * There are 5 words reserved for future use. Check that userspace
1349 * doesn't put stuff in there to prevent breakages in the future.
1351 for (i
= 0; i
< 5; i
++)
1352 if (iso7816
.reserved
[i
])
1355 spin_lock_irqsave(&port
->lock
, flags
);
1356 ret
= port
->iso7816_config(port
, &iso7816
);
1357 spin_unlock_irqrestore(&port
->lock
, flags
);
1361 if (copy_to_user(iso7816_user
, &port
->iso7816
, sizeof(port
->iso7816
)))
1368 * Called via sys_ioctl. We can use spin_lock_irq() here.
1371 uart_ioctl(struct tty_struct
*tty
, unsigned int cmd
, unsigned long arg
)
1373 struct uart_state
*state
= tty
->driver_data
;
1374 struct tty_port
*port
= &state
->port
;
1375 struct uart_port
*uport
;
1376 void __user
*uarg
= (void __user
*)arg
;
1377 int ret
= -ENOIOCTLCMD
;
1381 * These ioctls don't rely on the hardware to be present.
1385 down_write(&tty
->termios_rwsem
);
1386 ret
= uart_do_autoconfig(tty
, state
);
1387 up_write(&tty
->termios_rwsem
);
1391 if (ret
!= -ENOIOCTLCMD
)
1394 if (tty_io_error(tty
)) {
1400 * The following should only be used when hardware is present.
1404 ret
= uart_wait_modem_status(state
, arg
);
1408 if (ret
!= -ENOIOCTLCMD
)
1411 mutex_lock(&port
->mutex
);
1412 uport
= uart_port_check(state
);
1414 if (!uport
|| tty_io_error(tty
)) {
1420 * All these rely on hardware being present and need to be
1421 * protected against the tty being hung up.
1425 case TIOCSERGETLSR
: /* Get line status register */
1426 ret
= uart_get_lsr_info(tty
, state
, uarg
);
1430 ret
= uart_get_rs485_config(uport
, uarg
);
1434 ret
= uart_set_rs485_config(uport
, uarg
);
1438 ret
= uart_set_iso7816_config(state
->uart_port
, uarg
);
1442 ret
= uart_get_iso7816_config(state
->uart_port
, uarg
);
1445 if (uport
->ops
->ioctl
)
1446 ret
= uport
->ops
->ioctl(uport
, cmd
, arg
);
1450 mutex_unlock(&port
->mutex
);
1455 static void uart_set_ldisc(struct tty_struct
*tty
)
1457 struct uart_state
*state
= tty
->driver_data
;
1458 struct uart_port
*uport
;
1460 mutex_lock(&state
->port
.mutex
);
1461 uport
= uart_port_check(state
);
1462 if (uport
&& uport
->ops
->set_ldisc
)
1463 uport
->ops
->set_ldisc(uport
, &tty
->termios
);
1464 mutex_unlock(&state
->port
.mutex
);
1467 static void uart_set_termios(struct tty_struct
*tty
,
1468 struct ktermios
*old_termios
)
1470 struct uart_state
*state
= tty
->driver_data
;
1471 struct uart_port
*uport
;
1472 unsigned int cflag
= tty
->termios
.c_cflag
;
1473 unsigned int iflag_mask
= IGNBRK
|BRKINT
|IGNPAR
|PARMRK
|INPCK
;
1474 bool sw_changed
= false;
1476 mutex_lock(&state
->port
.mutex
);
1477 uport
= uart_port_check(state
);
1482 * Drivers doing software flow control also need to know
1483 * about changes to these input settings.
1485 if (uport
->flags
& UPF_SOFT_FLOW
) {
1486 iflag_mask
|= IXANY
|IXON
|IXOFF
;
1488 tty
->termios
.c_cc
[VSTART
] != old_termios
->c_cc
[VSTART
] ||
1489 tty
->termios
.c_cc
[VSTOP
] != old_termios
->c_cc
[VSTOP
];
1493 * These are the bits that are used to setup various
1494 * flags in the low level driver. We can ignore the Bfoo
1495 * bits in c_cflag; c_[io]speed will always be set
1496 * appropriately by set_termios() in tty_ioctl.c
1498 if ((cflag
^ old_termios
->c_cflag
) == 0 &&
1499 tty
->termios
.c_ospeed
== old_termios
->c_ospeed
&&
1500 tty
->termios
.c_ispeed
== old_termios
->c_ispeed
&&
1501 ((tty
->termios
.c_iflag
^ old_termios
->c_iflag
) & iflag_mask
) == 0 &&
1506 uart_change_speed(tty
, state
, old_termios
);
1507 /* reload cflag from termios; port driver may have overriden flags */
1508 cflag
= tty
->termios
.c_cflag
;
1510 /* Handle transition to B0 status */
1511 if ((old_termios
->c_cflag
& CBAUD
) && !(cflag
& CBAUD
))
1512 uart_clear_mctrl(uport
, TIOCM_RTS
| TIOCM_DTR
);
1513 /* Handle transition away from B0 status */
1514 else if (!(old_termios
->c_cflag
& CBAUD
) && (cflag
& CBAUD
)) {
1515 unsigned int mask
= TIOCM_DTR
;
1516 if (!(cflag
& CRTSCTS
) || !tty_throttled(tty
))
1518 uart_set_mctrl(uport
, mask
);
1521 mutex_unlock(&state
->port
.mutex
);
1525 * Calls to uart_close() are serialised via the tty_lock in
1526 * drivers/tty/tty_io.c:tty_release()
1527 * drivers/tty/tty_io.c:do_tty_hangup()
1529 static void uart_close(struct tty_struct
*tty
, struct file
*filp
)
1531 struct uart_state
*state
= tty
->driver_data
;
1534 struct uart_driver
*drv
= tty
->driver
->driver_state
;
1535 struct tty_port
*port
;
1537 state
= drv
->state
+ tty
->index
;
1538 port
= &state
->port
;
1539 spin_lock_irq(&port
->lock
);
1541 spin_unlock_irq(&port
->lock
);
1545 pr_debug("uart_close(%d) called\n", tty
->index
);
1547 tty_port_close(tty
->port
, tty
, filp
);
1550 static void uart_tty_port_shutdown(struct tty_port
*port
)
1552 struct uart_state
*state
= container_of(port
, struct uart_state
, port
);
1553 struct uart_port
*uport
= uart_port_check(state
);
1556 * At this point, we stop accepting input. To do this, we
1557 * disable the receive line status interrupts.
1559 if (WARN(!uport
, "detached port still initialized!\n"))
1562 spin_lock_irq(&uport
->lock
);
1563 uport
->ops
->stop_rx(uport
);
1564 spin_unlock_irq(&uport
->lock
);
1566 uart_port_shutdown(port
);
1569 * It's possible for shutdown to be called after suspend if we get
1570 * a DCD drop (hangup) at just the right time. Clear suspended bit so
1571 * we don't try to resume a port that has been shutdown.
1573 tty_port_set_suspended(port
, 0);
1575 uart_change_pm(state
, UART_PM_STATE_OFF
);
1579 static void uart_wait_until_sent(struct tty_struct
*tty
, int timeout
)
1581 struct uart_state
*state
= tty
->driver_data
;
1582 struct uart_port
*port
;
1583 unsigned long char_time
, expire
;
1585 port
= uart_port_ref(state
);
1589 if (port
->type
== PORT_UNKNOWN
|| port
->fifosize
== 0) {
1590 uart_port_deref(port
);
1595 * Set the check interval to be 1/5 of the estimated time to
1596 * send a single character, and make it at least 1. The check
1597 * interval should also be less than the timeout.
1599 * Note: we have to use pretty tight timings here to satisfy
1602 char_time
= (port
->timeout
- HZ
/50) / port
->fifosize
;
1603 char_time
= char_time
/ 5;
1606 if (timeout
&& timeout
< char_time
)
1607 char_time
= timeout
;
1610 * If the transmitter hasn't cleared in twice the approximate
1611 * amount of time to send the entire FIFO, it probably won't
1612 * ever clear. This assumes the UART isn't doing flow
1613 * control, which is currently the case. Hence, if it ever
1614 * takes longer than port->timeout, this is probably due to a
1615 * UART bug of some kind. So, we clamp the timeout parameter at
1618 if (timeout
== 0 || timeout
> 2 * port
->timeout
)
1619 timeout
= 2 * port
->timeout
;
1621 expire
= jiffies
+ timeout
;
1623 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1624 port
->line
, jiffies
, expire
);
1627 * Check whether the transmitter is empty every 'char_time'.
1628 * 'timeout' / 'expire' give us the maximum amount of time
1631 while (!port
->ops
->tx_empty(port
)) {
1632 msleep_interruptible(jiffies_to_msecs(char_time
));
1633 if (signal_pending(current
))
1635 if (time_after(jiffies
, expire
))
1638 uart_port_deref(port
);
1642 * Calls to uart_hangup() are serialised by the tty_lock in
1643 * drivers/tty/tty_io.c:do_tty_hangup()
1644 * This runs from a workqueue and can sleep for a _short_ time only.
1646 static void uart_hangup(struct tty_struct
*tty
)
1648 struct uart_state
*state
= tty
->driver_data
;
1649 struct tty_port
*port
= &state
->port
;
1650 struct uart_port
*uport
;
1651 unsigned long flags
;
1653 pr_debug("uart_hangup(%d)\n", tty
->index
);
1655 mutex_lock(&port
->mutex
);
1656 uport
= uart_port_check(state
);
1657 WARN(!uport
, "hangup of detached port!\n");
1659 if (tty_port_active(port
)) {
1660 uart_flush_buffer(tty
);
1661 uart_shutdown(tty
, state
);
1662 spin_lock_irqsave(&port
->lock
, flags
);
1664 spin_unlock_irqrestore(&port
->lock
, flags
);
1665 tty_port_set_active(port
, 0);
1666 tty_port_tty_set(port
, NULL
);
1667 if (uport
&& !uart_console(uport
))
1668 uart_change_pm(state
, UART_PM_STATE_OFF
);
1669 wake_up_interruptible(&port
->open_wait
);
1670 wake_up_interruptible(&port
->delta_msr_wait
);
1672 mutex_unlock(&port
->mutex
);
1675 /* uport == NULL if uart_port has already been removed */
1676 static void uart_port_shutdown(struct tty_port
*port
)
1678 struct uart_state
*state
= container_of(port
, struct uart_state
, port
);
1679 struct uart_port
*uport
= uart_port_check(state
);
1682 * clear delta_msr_wait queue to avoid mem leaks: we may free
1683 * the irq here so the queue might never be woken up. Note
1684 * that we won't end up waiting on delta_msr_wait again since
1685 * any outstanding file descriptors should be pointing at
1686 * hung_up_tty_fops now.
1688 wake_up_interruptible(&port
->delta_msr_wait
);
1691 * Free the IRQ and disable the port.
1694 uport
->ops
->shutdown(uport
);
1697 * Ensure that the IRQ handler isn't running on another CPU.
1700 synchronize_irq(uport
->irq
);
1703 static int uart_carrier_raised(struct tty_port
*port
)
1705 struct uart_state
*state
= container_of(port
, struct uart_state
, port
);
1706 struct uart_port
*uport
;
1709 uport
= uart_port_ref(state
);
1711 * Should never observe uport == NULL since checks for hangup should
1712 * abort the tty_port_block_til_ready() loop before checking for carrier
1713 * raised -- but report carrier raised if it does anyway so open will
1714 * continue and not sleep
1716 if (WARN_ON(!uport
))
1718 spin_lock_irq(&uport
->lock
);
1719 uart_enable_ms(uport
);
1720 mctrl
= uport
->ops
->get_mctrl(uport
);
1721 spin_unlock_irq(&uport
->lock
);
1722 uart_port_deref(uport
);
1723 if (mctrl
& TIOCM_CAR
)
1728 static void uart_dtr_rts(struct tty_port
*port
, int raise
)
1730 struct uart_state
*state
= container_of(port
, struct uart_state
, port
);
1731 struct uart_port
*uport
;
1733 uport
= uart_port_ref(state
);
1736 uart_port_dtr_rts(uport
, raise
);
1737 uart_port_deref(uport
);
1741 * Calls to uart_open are serialised by the tty_lock in
1742 * drivers/tty/tty_io.c:tty_open()
1743 * Note that if this fails, then uart_close() _will_ be called.
1745 * In time, we want to scrap the "opening nonpresent ports"
1746 * behaviour and implement an alternative way for setserial
1747 * to set base addresses/ports/types. This will allow us to
1748 * get rid of a certain amount of extra tests.
1750 static int uart_open(struct tty_struct
*tty
, struct file
*filp
)
1752 struct uart_driver
*drv
= tty
->driver
->driver_state
;
1753 int retval
, line
= tty
->index
;
1754 struct uart_state
*state
= drv
->state
+ line
;
1756 tty
->driver_data
= state
;
1758 retval
= tty_port_open(&state
->port
, tty
, filp
);
1765 static int uart_port_activate(struct tty_port
*port
, struct tty_struct
*tty
)
1767 struct uart_state
*state
= container_of(port
, struct uart_state
, port
);
1768 struct uart_port
*uport
;
1770 uport
= uart_port_check(state
);
1771 if (!uport
|| uport
->flags
& UPF_DEAD
)
1774 port
->low_latency
= (uport
->flags
& UPF_LOW_LATENCY
) ? 1 : 0;
1777 * Start up the serial port.
1779 return uart_startup(tty
, state
, 0);
1782 static const char *uart_type(struct uart_port
*port
)
1784 const char *str
= NULL
;
1786 if (port
->ops
->type
)
1787 str
= port
->ops
->type(port
);
1795 #ifdef CONFIG_PROC_FS
1797 static void uart_line_info(struct seq_file
*m
, struct uart_driver
*drv
, int i
)
1799 struct uart_state
*state
= drv
->state
+ i
;
1800 struct tty_port
*port
= &state
->port
;
1801 enum uart_pm_state pm_state
;
1802 struct uart_port
*uport
;
1804 unsigned int status
;
1807 mutex_lock(&port
->mutex
);
1808 uport
= uart_port_check(state
);
1812 mmio
= uport
->iotype
>= UPIO_MEM
;
1813 seq_printf(m
, "%d: uart:%s %s%08llX irq:%d",
1814 uport
->line
, uart_type(uport
),
1815 mmio
? "mmio:0x" : "port:",
1816 mmio
? (unsigned long long)uport
->mapbase
1817 : (unsigned long long)uport
->iobase
,
1820 if (uport
->type
== PORT_UNKNOWN
) {
1825 if (capable(CAP_SYS_ADMIN
)) {
1826 pm_state
= state
->pm_state
;
1827 if (pm_state
!= UART_PM_STATE_ON
)
1828 uart_change_pm(state
, UART_PM_STATE_ON
);
1829 spin_lock_irq(&uport
->lock
);
1830 status
= uport
->ops
->get_mctrl(uport
);
1831 spin_unlock_irq(&uport
->lock
);
1832 if (pm_state
!= UART_PM_STATE_ON
)
1833 uart_change_pm(state
, pm_state
);
1835 seq_printf(m
, " tx:%d rx:%d",
1836 uport
->icount
.tx
, uport
->icount
.rx
);
1837 if (uport
->icount
.frame
)
1838 seq_printf(m
, " fe:%d", uport
->icount
.frame
);
1839 if (uport
->icount
.parity
)
1840 seq_printf(m
, " pe:%d", uport
->icount
.parity
);
1841 if (uport
->icount
.brk
)
1842 seq_printf(m
, " brk:%d", uport
->icount
.brk
);
1843 if (uport
->icount
.overrun
)
1844 seq_printf(m
, " oe:%d", uport
->icount
.overrun
);
1845 if (uport
->icount
.buf_overrun
)
1846 seq_printf(m
, " bo:%d", uport
->icount
.buf_overrun
);
1848 #define INFOBIT(bit, str) \
1849 if (uport->mctrl & (bit)) \
1850 strncat(stat_buf, (str), sizeof(stat_buf) - \
1851 strlen(stat_buf) - 2)
1852 #define STATBIT(bit, str) \
1853 if (status & (bit)) \
1854 strncat(stat_buf, (str), sizeof(stat_buf) - \
1855 strlen(stat_buf) - 2)
1859 INFOBIT(TIOCM_RTS
, "|RTS");
1860 STATBIT(TIOCM_CTS
, "|CTS");
1861 INFOBIT(TIOCM_DTR
, "|DTR");
1862 STATBIT(TIOCM_DSR
, "|DSR");
1863 STATBIT(TIOCM_CAR
, "|CD");
1864 STATBIT(TIOCM_RNG
, "|RI");
1868 seq_puts(m
, stat_buf
);
1874 mutex_unlock(&port
->mutex
);
1877 static int uart_proc_show(struct seq_file
*m
, void *v
)
1879 struct tty_driver
*ttydrv
= m
->private;
1880 struct uart_driver
*drv
= ttydrv
->driver_state
;
1883 seq_printf(m
, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
1884 for (i
= 0; i
< drv
->nr
; i
++)
1885 uart_line_info(m
, drv
, i
);
1890 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1892 * uart_console_write - write a console message to a serial port
1893 * @port: the port to write the message
1894 * @s: array of characters
1895 * @count: number of characters in string to write
1896 * @putchar: function to write character to port
1898 void uart_console_write(struct uart_port
*port
, const char *s
,
1900 void (*putchar
)(struct uart_port
*, int))
1904 for (i
= 0; i
< count
; i
++, s
++) {
1906 putchar(port
, '\r');
1910 EXPORT_SYMBOL_GPL(uart_console_write
);
1913 * Check whether an invalid uart number has been specified, and
1914 * if so, search for the first available port that does have
1917 struct uart_port
* __init
1918 uart_get_console(struct uart_port
*ports
, int nr
, struct console
*co
)
1920 int idx
= co
->index
;
1922 if (idx
< 0 || idx
>= nr
|| (ports
[idx
].iobase
== 0 &&
1923 ports
[idx
].membase
== NULL
))
1924 for (idx
= 0; idx
< nr
; idx
++)
1925 if (ports
[idx
].iobase
!= 0 ||
1926 ports
[idx
].membase
!= NULL
)
1935 * uart_parse_earlycon - Parse earlycon options
1936 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1937 * @iotype: ptr for decoded iotype (out)
1938 * @addr: ptr for decoded mapbase/iobase (out)
1939 * @options: ptr for <options> field; NULL if not present (out)
1941 * Decodes earlycon kernel command line parameters of the form
1942 * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1943 * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1946 * earlycon=<name>,0x<addr>,<options>
1947 * console=<name>,0x<addr>,<options>
1948 * is also accepted; the returned @iotype will be UPIO_MEM.
1950 * Returns 0 on success or -EINVAL on failure
1952 int uart_parse_earlycon(char *p
, unsigned char *iotype
, resource_size_t
*addr
,
1955 if (strncmp(p
, "mmio,", 5) == 0) {
1958 } else if (strncmp(p
, "mmio16,", 7) == 0) {
1959 *iotype
= UPIO_MEM16
;
1961 } else if (strncmp(p
, "mmio32,", 7) == 0) {
1962 *iotype
= UPIO_MEM32
;
1964 } else if (strncmp(p
, "mmio32be,", 9) == 0) {
1965 *iotype
= UPIO_MEM32BE
;
1967 } else if (strncmp(p
, "mmio32native,", 13) == 0) {
1968 *iotype
= IS_ENABLED(CONFIG_CPU_BIG_ENDIAN
) ?
1969 UPIO_MEM32BE
: UPIO_MEM32
;
1971 } else if (strncmp(p
, "io,", 3) == 0) {
1972 *iotype
= UPIO_PORT
;
1974 } else if (strncmp(p
, "0x", 2) == 0) {
1981 * Before you replace it with kstrtoull(), think about options separator
1982 * (',') it will not tolerate
1984 *addr
= simple_strtoull(p
, NULL
, 0);
1992 EXPORT_SYMBOL_GPL(uart_parse_earlycon
);
1995 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1996 * @options: pointer to option string
1997 * @baud: pointer to an 'int' variable for the baud rate.
1998 * @parity: pointer to an 'int' variable for the parity.
1999 * @bits: pointer to an 'int' variable for the number of data bits.
2000 * @flow: pointer to an 'int' variable for the flow control character.
2002 * uart_parse_options decodes a string containing the serial console
2003 * options. The format of the string is <baud><parity><bits><flow>,
2007 uart_parse_options(const char *options
, int *baud
, int *parity
,
2008 int *bits
, int *flow
)
2010 const char *s
= options
;
2012 *baud
= simple_strtoul(s
, NULL
, 10);
2013 while (*s
>= '0' && *s
<= '9')
2022 EXPORT_SYMBOL_GPL(uart_parse_options
);
2025 * uart_set_options - setup the serial console parameters
2026 * @port: pointer to the serial ports uart_port structure
2027 * @co: console pointer
2029 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
2030 * @bits: number of data bits
2031 * @flow: flow control character - 'r' (rts)
2034 uart_set_options(struct uart_port
*port
, struct console
*co
,
2035 int baud
, int parity
, int bits
, int flow
)
2037 struct ktermios termios
;
2038 static struct ktermios dummy
;
2041 * Ensure that the serial console lock is initialised
2043 * If this port is a console, then the spinlock is already
2046 if (!(uart_console(port
) && (port
->cons
->flags
& CON_ENABLED
))) {
2047 spin_lock_init(&port
->lock
);
2048 lockdep_set_class(&port
->lock
, &port_lock_key
);
2051 memset(&termios
, 0, sizeof(struct ktermios
));
2053 termios
.c_cflag
|= CREAD
| HUPCL
| CLOCAL
;
2054 tty_termios_encode_baud_rate(&termios
, baud
, baud
);
2057 termios
.c_cflag
|= CS7
;
2059 termios
.c_cflag
|= CS8
;
2063 termios
.c_cflag
|= PARODD
;
2066 termios
.c_cflag
|= PARENB
;
2071 termios
.c_cflag
|= CRTSCTS
;
2074 * some uarts on other side don't support no flow control.
2075 * So we set * DTR in host uart to make them happy
2077 port
->mctrl
|= TIOCM_DTR
;
2079 port
->ops
->set_termios(port
, &termios
, &dummy
);
2081 * Allow the setting of the UART parameters with a NULL console
2085 co
->cflag
= termios
.c_cflag
;
2089 EXPORT_SYMBOL_GPL(uart_set_options
);
2090 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
2093 * uart_change_pm - set power state of the port
2095 * @state: port descriptor
2096 * @pm_state: new state
2098 * Locking: port->mutex has to be held
2100 static void uart_change_pm(struct uart_state
*state
,
2101 enum uart_pm_state pm_state
)
2103 struct uart_port
*port
= uart_port_check(state
);
2105 if (state
->pm_state
!= pm_state
) {
2106 if (port
&& port
->ops
->pm
)
2107 port
->ops
->pm(port
, pm_state
, state
->pm_state
);
2108 state
->pm_state
= pm_state
;
2113 struct uart_port
*port
;
2114 struct uart_driver
*driver
;
2117 static int serial_match_port(struct device
*dev
, void *data
)
2119 struct uart_match
*match
= data
;
2120 struct tty_driver
*tty_drv
= match
->driver
->tty_driver
;
2121 dev_t devt
= MKDEV(tty_drv
->major
, tty_drv
->minor_start
) +
2124 return dev
->devt
== devt
; /* Actually, only one tty per port */
2127 int uart_suspend_port(struct uart_driver
*drv
, struct uart_port
*uport
)
2129 struct uart_state
*state
= drv
->state
+ uport
->line
;
2130 struct tty_port
*port
= &state
->port
;
2131 struct device
*tty_dev
;
2132 struct uart_match match
= {uport
, drv
};
2134 mutex_lock(&port
->mutex
);
2136 tty_dev
= device_find_child(uport
->dev
, &match
, serial_match_port
);
2137 if (tty_dev
&& device_may_wakeup(tty_dev
)) {
2138 enable_irq_wake(uport
->irq
);
2139 put_device(tty_dev
);
2140 mutex_unlock(&port
->mutex
);
2143 put_device(tty_dev
);
2145 /* Nothing to do if the console is not suspending */
2146 if (!console_suspend_enabled
&& uart_console(uport
))
2149 uport
->suspended
= 1;
2151 if (tty_port_initialized(port
)) {
2152 const struct uart_ops
*ops
= uport
->ops
;
2155 tty_port_set_suspended(port
, 1);
2156 tty_port_set_initialized(port
, 0);
2158 spin_lock_irq(&uport
->lock
);
2159 ops
->stop_tx(uport
);
2160 ops
->set_mctrl(uport
, 0);
2161 ops
->stop_rx(uport
);
2162 spin_unlock_irq(&uport
->lock
);
2165 * Wait for the transmitter to empty.
2167 for (tries
= 3; !ops
->tx_empty(uport
) && tries
; tries
--)
2170 dev_err(uport
->dev
, "%s: Unable to drain transmitter\n",
2173 ops
->shutdown(uport
);
2177 * Disable the console device before suspending.
2179 if (uart_console(uport
))
2180 console_stop(uport
->cons
);
2182 uart_change_pm(state
, UART_PM_STATE_OFF
);
2184 mutex_unlock(&port
->mutex
);
2189 int uart_resume_port(struct uart_driver
*drv
, struct uart_port
*uport
)
2191 struct uart_state
*state
= drv
->state
+ uport
->line
;
2192 struct tty_port
*port
= &state
->port
;
2193 struct device
*tty_dev
;
2194 struct uart_match match
= {uport
, drv
};
2195 struct ktermios termios
;
2197 mutex_lock(&port
->mutex
);
2199 tty_dev
= device_find_child(uport
->dev
, &match
, serial_match_port
);
2200 if (!uport
->suspended
&& device_may_wakeup(tty_dev
)) {
2201 if (irqd_is_wakeup_set(irq_get_irq_data((uport
->irq
))))
2202 disable_irq_wake(uport
->irq
);
2203 put_device(tty_dev
);
2204 mutex_unlock(&port
->mutex
);
2207 put_device(tty_dev
);
2208 uport
->suspended
= 0;
2211 * Re-enable the console device after suspending.
2213 if (uart_console(uport
)) {
2215 * First try to use the console cflag setting.
2217 memset(&termios
, 0, sizeof(struct ktermios
));
2218 termios
.c_cflag
= uport
->cons
->cflag
;
2221 * If that's unset, use the tty termios setting.
2223 if (port
->tty
&& termios
.c_cflag
== 0)
2224 termios
= port
->tty
->termios
;
2226 if (console_suspend_enabled
)
2227 uart_change_pm(state
, UART_PM_STATE_ON
);
2228 uport
->ops
->set_termios(uport
, &termios
, NULL
);
2229 if (console_suspend_enabled
)
2230 console_start(uport
->cons
);
2233 if (tty_port_suspended(port
)) {
2234 const struct uart_ops
*ops
= uport
->ops
;
2237 uart_change_pm(state
, UART_PM_STATE_ON
);
2238 spin_lock_irq(&uport
->lock
);
2239 ops
->set_mctrl(uport
, 0);
2240 spin_unlock_irq(&uport
->lock
);
2241 if (console_suspend_enabled
|| !uart_console(uport
)) {
2242 /* Protected by port mutex for now */
2243 struct tty_struct
*tty
= port
->tty
;
2244 ret
= ops
->startup(uport
);
2247 uart_change_speed(tty
, state
, NULL
);
2248 spin_lock_irq(&uport
->lock
);
2249 ops
->set_mctrl(uport
, uport
->mctrl
);
2250 ops
->start_tx(uport
);
2251 spin_unlock_irq(&uport
->lock
);
2252 tty_port_set_initialized(port
, 1);
2255 * Failed to resume - maybe hardware went away?
2256 * Clear the "initialized" flag so we won't try
2257 * to call the low level drivers shutdown method.
2259 uart_shutdown(tty
, state
);
2263 tty_port_set_suspended(port
, 0);
2266 mutex_unlock(&port
->mutex
);
2272 uart_report_port(struct uart_driver
*drv
, struct uart_port
*port
)
2276 switch (port
->iotype
) {
2278 snprintf(address
, sizeof(address
), "I/O 0x%lx", port
->iobase
);
2281 snprintf(address
, sizeof(address
),
2282 "I/O 0x%lx offset 0x%x", port
->iobase
, port
->hub6
);
2290 snprintf(address
, sizeof(address
),
2291 "MMIO 0x%llx", (unsigned long long)port
->mapbase
);
2294 strlcpy(address
, "*unknown*", sizeof(address
));
2298 pr_info("%s%s%s at %s (irq = %d, base_baud = %d) is a %s\n",
2299 port
->dev
? dev_name(port
->dev
) : "",
2300 port
->dev
? ": " : "",
2302 address
, port
->irq
, port
->uartclk
/ 16, uart_type(port
));
2306 uart_configure_port(struct uart_driver
*drv
, struct uart_state
*state
,
2307 struct uart_port
*port
)
2312 * If there isn't a port here, don't do anything further.
2314 if (!port
->iobase
&& !port
->mapbase
&& !port
->membase
)
2318 * Now do the auto configuration stuff. Note that config_port
2319 * is expected to claim the resources and map the port for us.
2322 if (port
->flags
& UPF_AUTO_IRQ
)
2323 flags
|= UART_CONFIG_IRQ
;
2324 if (port
->flags
& UPF_BOOT_AUTOCONF
) {
2325 if (!(port
->flags
& UPF_FIXED_TYPE
)) {
2326 port
->type
= PORT_UNKNOWN
;
2327 flags
|= UART_CONFIG_TYPE
;
2329 port
->ops
->config_port(port
, flags
);
2332 if (port
->type
!= PORT_UNKNOWN
) {
2333 unsigned long flags
;
2335 uart_report_port(drv
, port
);
2337 /* Power up port for set_mctrl() */
2338 uart_change_pm(state
, UART_PM_STATE_ON
);
2341 * Ensure that the modem control lines are de-activated.
2342 * keep the DTR setting that is set in uart_set_options()
2343 * We probably don't need a spinlock around this, but
2345 spin_lock_irqsave(&port
->lock
, flags
);
2346 port
->ops
->set_mctrl(port
, port
->mctrl
& TIOCM_DTR
);
2347 spin_unlock_irqrestore(&port
->lock
, flags
);
2350 * If this driver supports console, and it hasn't been
2351 * successfully registered yet, try to re-register it.
2352 * It may be that the port was not available.
2354 if (port
->cons
&& !(port
->cons
->flags
& CON_ENABLED
))
2355 register_console(port
->cons
);
2358 * Power down all ports by default, except the
2359 * console if we have one.
2361 if (!uart_console(port
))
2362 uart_change_pm(state
, UART_PM_STATE_OFF
);
2366 #ifdef CONFIG_CONSOLE_POLL
2368 static int uart_poll_init(struct tty_driver
*driver
, int line
, char *options
)
2370 struct uart_driver
*drv
= driver
->driver_state
;
2371 struct uart_state
*state
= drv
->state
+ line
;
2372 struct tty_port
*tport
;
2373 struct uart_port
*port
;
2380 tport
= &state
->port
;
2381 mutex_lock(&tport
->mutex
);
2383 port
= uart_port_check(state
);
2384 if (!port
|| !(port
->ops
->poll_get_char
&& port
->ops
->poll_put_char
)) {
2389 if (port
->ops
->poll_init
) {
2391 * We don't set initialized as we only initialized the hw,
2392 * e.g. state->xmit is still uninitialized.
2394 if (!tty_port_initialized(tport
))
2395 ret
= port
->ops
->poll_init(port
);
2398 if (!ret
&& options
) {
2399 uart_parse_options(options
, &baud
, &parity
, &bits
, &flow
);
2400 ret
= uart_set_options(port
, NULL
, baud
, parity
, bits
, flow
);
2403 mutex_unlock(&tport
->mutex
);
2407 static int uart_poll_get_char(struct tty_driver
*driver
, int line
)
2409 struct uart_driver
*drv
= driver
->driver_state
;
2410 struct uart_state
*state
= drv
->state
+ line
;
2411 struct uart_port
*port
;
2414 port
= uart_port_ref(state
);
2416 ret
= port
->ops
->poll_get_char(port
);
2417 uart_port_deref(port
);
2423 static void uart_poll_put_char(struct tty_driver
*driver
, int line
, char ch
)
2425 struct uart_driver
*drv
= driver
->driver_state
;
2426 struct uart_state
*state
= drv
->state
+ line
;
2427 struct uart_port
*port
;
2429 port
= uart_port_ref(state
);
2434 port
->ops
->poll_put_char(port
, '\r');
2435 port
->ops
->poll_put_char(port
, ch
);
2436 uart_port_deref(port
);
2440 static const struct tty_operations uart_ops
= {
2442 .close
= uart_close
,
2443 .write
= uart_write
,
2444 .put_char
= uart_put_char
,
2445 .flush_chars
= uart_flush_chars
,
2446 .write_room
= uart_write_room
,
2447 .chars_in_buffer
= uart_chars_in_buffer
,
2448 .flush_buffer
= uart_flush_buffer
,
2449 .ioctl
= uart_ioctl
,
2450 .throttle
= uart_throttle
,
2451 .unthrottle
= uart_unthrottle
,
2452 .send_xchar
= uart_send_xchar
,
2453 .set_termios
= uart_set_termios
,
2454 .set_ldisc
= uart_set_ldisc
,
2456 .start
= uart_start
,
2457 .hangup
= uart_hangup
,
2458 .break_ctl
= uart_break_ctl
,
2459 .wait_until_sent
= uart_wait_until_sent
,
2460 #ifdef CONFIG_PROC_FS
2461 .proc_show
= uart_proc_show
,
2463 .tiocmget
= uart_tiocmget
,
2464 .tiocmset
= uart_tiocmset
,
2465 .set_serial
= uart_set_info_user
,
2466 .get_serial
= uart_get_info_user
,
2467 .get_icount
= uart_get_icount
,
2468 #ifdef CONFIG_CONSOLE_POLL
2469 .poll_init
= uart_poll_init
,
2470 .poll_get_char
= uart_poll_get_char
,
2471 .poll_put_char
= uart_poll_put_char
,
2475 static const struct tty_port_operations uart_port_ops
= {
2476 .carrier_raised
= uart_carrier_raised
,
2477 .dtr_rts
= uart_dtr_rts
,
2478 .activate
= uart_port_activate
,
2479 .shutdown
= uart_tty_port_shutdown
,
2483 * uart_register_driver - register a driver with the uart core layer
2484 * @drv: low level driver structure
2486 * Register a uart driver with the core driver. We in turn register
2487 * with the tty layer, and initialise the core driver per-port state.
2489 * We have a proc file in /proc/tty/driver which is named after the
2492 * drv->port should be NULL, and the per-port structures should be
2493 * registered using uart_add_one_port after this call has succeeded.
2495 int uart_register_driver(struct uart_driver
*drv
)
2497 struct tty_driver
*normal
;
2503 * Maybe we should be using a slab cache for this, especially if
2504 * we have a large number of ports to handle.
2506 drv
->state
= kcalloc(drv
->nr
, sizeof(struct uart_state
), GFP_KERNEL
);
2510 normal
= alloc_tty_driver(drv
->nr
);
2514 drv
->tty_driver
= normal
;
2516 normal
->driver_name
= drv
->driver_name
;
2517 normal
->name
= drv
->dev_name
;
2518 normal
->major
= drv
->major
;
2519 normal
->minor_start
= drv
->minor
;
2520 normal
->type
= TTY_DRIVER_TYPE_SERIAL
;
2521 normal
->subtype
= SERIAL_TYPE_NORMAL
;
2522 normal
->init_termios
= tty_std_termios
;
2523 normal
->init_termios
.c_cflag
= B9600
| CS8
| CREAD
| HUPCL
| CLOCAL
;
2524 normal
->init_termios
.c_ispeed
= normal
->init_termios
.c_ospeed
= 9600;
2525 normal
->flags
= TTY_DRIVER_REAL_RAW
| TTY_DRIVER_DYNAMIC_DEV
;
2526 normal
->driver_state
= drv
;
2527 tty_set_operations(normal
, &uart_ops
);
2530 * Initialise the UART state(s).
2532 for (i
= 0; i
< drv
->nr
; i
++) {
2533 struct uart_state
*state
= drv
->state
+ i
;
2534 struct tty_port
*port
= &state
->port
;
2536 tty_port_init(port
);
2537 port
->ops
= &uart_port_ops
;
2540 retval
= tty_register_driver(normal
);
2544 for (i
= 0; i
< drv
->nr
; i
++)
2545 tty_port_destroy(&drv
->state
[i
].port
);
2546 put_tty_driver(normal
);
2554 * uart_unregister_driver - remove a driver from the uart core layer
2555 * @drv: low level driver structure
2557 * Remove all references to a driver from the core driver. The low
2558 * level driver must have removed all its ports via the
2559 * uart_remove_one_port() if it registered them with uart_add_one_port().
2560 * (ie, drv->port == NULL)
2562 void uart_unregister_driver(struct uart_driver
*drv
)
2564 struct tty_driver
*p
= drv
->tty_driver
;
2567 tty_unregister_driver(p
);
2569 for (i
= 0; i
< drv
->nr
; i
++)
2570 tty_port_destroy(&drv
->state
[i
].port
);
2573 drv
->tty_driver
= NULL
;
2576 struct tty_driver
*uart_console_device(struct console
*co
, int *index
)
2578 struct uart_driver
*p
= co
->data
;
2580 return p
->tty_driver
;
2583 static ssize_t
uart_get_attr_uartclk(struct device
*dev
,
2584 struct device_attribute
*attr
, char *buf
)
2586 struct serial_struct tmp
;
2587 struct tty_port
*port
= dev_get_drvdata(dev
);
2589 uart_get_info(port
, &tmp
);
2590 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.baud_base
* 16);
2593 static ssize_t
uart_get_attr_type(struct device
*dev
,
2594 struct device_attribute
*attr
, char *buf
)
2596 struct serial_struct tmp
;
2597 struct tty_port
*port
= dev_get_drvdata(dev
);
2599 uart_get_info(port
, &tmp
);
2600 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.type
);
2602 static ssize_t
uart_get_attr_line(struct device
*dev
,
2603 struct device_attribute
*attr
, char *buf
)
2605 struct serial_struct tmp
;
2606 struct tty_port
*port
= dev_get_drvdata(dev
);
2608 uart_get_info(port
, &tmp
);
2609 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.line
);
2612 static ssize_t
uart_get_attr_port(struct device
*dev
,
2613 struct device_attribute
*attr
, char *buf
)
2615 struct serial_struct tmp
;
2616 struct tty_port
*port
= dev_get_drvdata(dev
);
2617 unsigned long ioaddr
;
2619 uart_get_info(port
, &tmp
);
2621 if (HIGH_BITS_OFFSET
)
2622 ioaddr
|= (unsigned long)tmp
.port_high
<< HIGH_BITS_OFFSET
;
2623 return snprintf(buf
, PAGE_SIZE
, "0x%lX\n", ioaddr
);
2626 static ssize_t
uart_get_attr_irq(struct device
*dev
,
2627 struct device_attribute
*attr
, char *buf
)
2629 struct serial_struct tmp
;
2630 struct tty_port
*port
= dev_get_drvdata(dev
);
2632 uart_get_info(port
, &tmp
);
2633 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.irq
);
2636 static ssize_t
uart_get_attr_flags(struct device
*dev
,
2637 struct device_attribute
*attr
, char *buf
)
2639 struct serial_struct tmp
;
2640 struct tty_port
*port
= dev_get_drvdata(dev
);
2642 uart_get_info(port
, &tmp
);
2643 return snprintf(buf
, PAGE_SIZE
, "0x%X\n", tmp
.flags
);
2646 static ssize_t
uart_get_attr_xmit_fifo_size(struct device
*dev
,
2647 struct device_attribute
*attr
, char *buf
)
2649 struct serial_struct tmp
;
2650 struct tty_port
*port
= dev_get_drvdata(dev
);
2652 uart_get_info(port
, &tmp
);
2653 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.xmit_fifo_size
);
2657 static ssize_t
uart_get_attr_close_delay(struct device
*dev
,
2658 struct device_attribute
*attr
, char *buf
)
2660 struct serial_struct tmp
;
2661 struct tty_port
*port
= dev_get_drvdata(dev
);
2663 uart_get_info(port
, &tmp
);
2664 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.close_delay
);
2668 static ssize_t
uart_get_attr_closing_wait(struct device
*dev
,
2669 struct device_attribute
*attr
, char *buf
)
2671 struct serial_struct tmp
;
2672 struct tty_port
*port
= dev_get_drvdata(dev
);
2674 uart_get_info(port
, &tmp
);
2675 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.closing_wait
);
2678 static ssize_t
uart_get_attr_custom_divisor(struct device
*dev
,
2679 struct device_attribute
*attr
, char *buf
)
2681 struct serial_struct tmp
;
2682 struct tty_port
*port
= dev_get_drvdata(dev
);
2684 uart_get_info(port
, &tmp
);
2685 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.custom_divisor
);
2688 static ssize_t
uart_get_attr_io_type(struct device
*dev
,
2689 struct device_attribute
*attr
, char *buf
)
2691 struct serial_struct tmp
;
2692 struct tty_port
*port
= dev_get_drvdata(dev
);
2694 uart_get_info(port
, &tmp
);
2695 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.io_type
);
2698 static ssize_t
uart_get_attr_iomem_base(struct device
*dev
,
2699 struct device_attribute
*attr
, char *buf
)
2701 struct serial_struct tmp
;
2702 struct tty_port
*port
= dev_get_drvdata(dev
);
2704 uart_get_info(port
, &tmp
);
2705 return snprintf(buf
, PAGE_SIZE
, "0x%lX\n", (unsigned long)tmp
.iomem_base
);
2708 static ssize_t
uart_get_attr_iomem_reg_shift(struct device
*dev
,
2709 struct device_attribute
*attr
, char *buf
)
2711 struct serial_struct tmp
;
2712 struct tty_port
*port
= dev_get_drvdata(dev
);
2714 uart_get_info(port
, &tmp
);
2715 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.iomem_reg_shift
);
2718 static DEVICE_ATTR(type
, S_IRUSR
| S_IRGRP
, uart_get_attr_type
, NULL
);
2719 static DEVICE_ATTR(line
, S_IRUSR
| S_IRGRP
, uart_get_attr_line
, NULL
);
2720 static DEVICE_ATTR(port
, S_IRUSR
| S_IRGRP
, uart_get_attr_port
, NULL
);
2721 static DEVICE_ATTR(irq
, S_IRUSR
| S_IRGRP
, uart_get_attr_irq
, NULL
);
2722 static DEVICE_ATTR(flags
, S_IRUSR
| S_IRGRP
, uart_get_attr_flags
, NULL
);
2723 static DEVICE_ATTR(xmit_fifo_size
, S_IRUSR
| S_IRGRP
, uart_get_attr_xmit_fifo_size
, NULL
);
2724 static DEVICE_ATTR(uartclk
, S_IRUSR
| S_IRGRP
, uart_get_attr_uartclk
, NULL
);
2725 static DEVICE_ATTR(close_delay
, S_IRUSR
| S_IRGRP
, uart_get_attr_close_delay
, NULL
);
2726 static DEVICE_ATTR(closing_wait
, S_IRUSR
| S_IRGRP
, uart_get_attr_closing_wait
, NULL
);
2727 static DEVICE_ATTR(custom_divisor
, S_IRUSR
| S_IRGRP
, uart_get_attr_custom_divisor
, NULL
);
2728 static DEVICE_ATTR(io_type
, S_IRUSR
| S_IRGRP
, uart_get_attr_io_type
, NULL
);
2729 static DEVICE_ATTR(iomem_base
, S_IRUSR
| S_IRGRP
, uart_get_attr_iomem_base
, NULL
);
2730 static DEVICE_ATTR(iomem_reg_shift
, S_IRUSR
| S_IRGRP
, uart_get_attr_iomem_reg_shift
, NULL
);
2732 static struct attribute
*tty_dev_attrs
[] = {
2733 &dev_attr_type
.attr
,
2734 &dev_attr_line
.attr
,
2735 &dev_attr_port
.attr
,
2737 &dev_attr_flags
.attr
,
2738 &dev_attr_xmit_fifo_size
.attr
,
2739 &dev_attr_uartclk
.attr
,
2740 &dev_attr_close_delay
.attr
,
2741 &dev_attr_closing_wait
.attr
,
2742 &dev_attr_custom_divisor
.attr
,
2743 &dev_attr_io_type
.attr
,
2744 &dev_attr_iomem_base
.attr
,
2745 &dev_attr_iomem_reg_shift
.attr
,
2749 static const struct attribute_group tty_dev_attr_group
= {
2750 .attrs
= tty_dev_attrs
,
2754 * uart_add_one_port - attach a driver-defined port structure
2755 * @drv: pointer to the uart low level driver structure for this port
2756 * @uport: uart port structure to use for this port.
2758 * This allows the driver to register its own uart_port structure
2759 * with the core driver. The main purpose is to allow the low
2760 * level uart drivers to expand uart_port, rather than having yet
2761 * more levels of structures.
2763 int uart_add_one_port(struct uart_driver
*drv
, struct uart_port
*uport
)
2765 struct uart_state
*state
;
2766 struct tty_port
*port
;
2768 struct device
*tty_dev
;
2771 BUG_ON(in_interrupt());
2773 if (uport
->line
>= drv
->nr
)
2776 state
= drv
->state
+ uport
->line
;
2777 port
= &state
->port
;
2779 mutex_lock(&port_mutex
);
2780 mutex_lock(&port
->mutex
);
2781 if (state
->uart_port
) {
2786 /* Link the port to the driver state table and vice versa */
2787 atomic_set(&state
->refcount
, 1);
2788 init_waitqueue_head(&state
->remove_wait
);
2789 state
->uart_port
= uport
;
2790 uport
->state
= state
;
2792 state
->pm_state
= UART_PM_STATE_UNDEFINED
;
2793 uport
->cons
= drv
->cons
;
2794 uport
->minor
= drv
->tty_driver
->minor_start
+ uport
->line
;
2795 uport
->name
= kasprintf(GFP_KERNEL
, "%s%d", drv
->dev_name
,
2796 drv
->tty_driver
->name_base
+ uport
->line
);
2803 * If this port is a console, then the spinlock is already
2806 if (!(uart_console(uport
) && (uport
->cons
->flags
& CON_ENABLED
))) {
2807 spin_lock_init(&uport
->lock
);
2808 lockdep_set_class(&uport
->lock
, &port_lock_key
);
2810 if (uport
->cons
&& uport
->dev
)
2811 of_console_check(uport
->dev
->of_node
, uport
->cons
->name
, uport
->line
);
2813 uart_configure_port(drv
, state
, uport
);
2815 port
->console
= uart_console(uport
);
2818 if (uport
->attr_group
)
2821 uport
->tty_groups
= kcalloc(num_groups
, sizeof(*uport
->tty_groups
),
2823 if (!uport
->tty_groups
) {
2827 uport
->tty_groups
[0] = &tty_dev_attr_group
;
2828 if (uport
->attr_group
)
2829 uport
->tty_groups
[1] = uport
->attr_group
;
2832 * Register the port whether it's detected or not. This allows
2833 * setserial to be used to alter this port's parameters.
2835 tty_dev
= tty_port_register_device_attr_serdev(port
, drv
->tty_driver
,
2836 uport
->line
, uport
->dev
, port
, uport
->tty_groups
);
2837 if (likely(!IS_ERR(tty_dev
))) {
2838 device_set_wakeup_capable(tty_dev
, 1);
2840 dev_err(uport
->dev
, "Cannot register tty device on line %d\n",
2845 * Ensure UPF_DEAD is not set.
2847 uport
->flags
&= ~UPF_DEAD
;
2850 mutex_unlock(&port
->mutex
);
2851 mutex_unlock(&port_mutex
);
2857 * uart_remove_one_port - detach a driver defined port structure
2858 * @drv: pointer to the uart low level driver structure for this port
2859 * @uport: uart port structure for this port
2861 * This unhooks (and hangs up) the specified port structure from the
2862 * core driver. No further calls will be made to the low-level code
2865 int uart_remove_one_port(struct uart_driver
*drv
, struct uart_port
*uport
)
2867 struct uart_state
*state
= drv
->state
+ uport
->line
;
2868 struct tty_port
*port
= &state
->port
;
2869 struct uart_port
*uart_port
;
2870 struct tty_struct
*tty
;
2873 BUG_ON(in_interrupt());
2875 mutex_lock(&port_mutex
);
2878 * Mark the port "dead" - this prevents any opens from
2879 * succeeding while we shut down the port.
2881 mutex_lock(&port
->mutex
);
2882 uart_port
= uart_port_check(state
);
2883 if (uart_port
!= uport
)
2884 dev_alert(uport
->dev
, "Removing wrong port: %p != %p\n",
2888 mutex_unlock(&port
->mutex
);
2892 uport
->flags
|= UPF_DEAD
;
2893 mutex_unlock(&port
->mutex
);
2896 * Remove the devices from the tty layer
2898 tty_port_unregister_device(port
, drv
->tty_driver
, uport
->line
);
2900 tty
= tty_port_tty_get(port
);
2902 tty_vhangup(port
->tty
);
2907 * If the port is used as a console, unregister it
2909 if (uart_console(uport
))
2910 unregister_console(uport
->cons
);
2913 * Free the port IO and memory resources, if any.
2915 if (uport
->type
!= PORT_UNKNOWN
&& uport
->ops
->release_port
)
2916 uport
->ops
->release_port(uport
);
2917 kfree(uport
->tty_groups
);
2921 * Indicate that there isn't a port here anymore.
2923 uport
->type
= PORT_UNKNOWN
;
2925 mutex_lock(&port
->mutex
);
2926 WARN_ON(atomic_dec_return(&state
->refcount
) < 0);
2927 wait_event(state
->remove_wait
, !atomic_read(&state
->refcount
));
2928 state
->uart_port
= NULL
;
2929 mutex_unlock(&port
->mutex
);
2931 mutex_unlock(&port_mutex
);
2937 * Are the two ports equivalent?
2939 int uart_match_port(struct uart_port
*port1
, struct uart_port
*port2
)
2941 if (port1
->iotype
!= port2
->iotype
)
2944 switch (port1
->iotype
) {
2946 return (port1
->iobase
== port2
->iobase
);
2948 return (port1
->iobase
== port2
->iobase
) &&
2949 (port1
->hub6
== port2
->hub6
);
2956 return (port1
->mapbase
== port2
->mapbase
);
2960 EXPORT_SYMBOL(uart_match_port
);
2963 * uart_handle_dcd_change - handle a change of carrier detect state
2964 * @uport: uart_port structure for the open port
2965 * @status: new carrier detect status, nonzero if active
2967 * Caller must hold uport->lock
2969 void uart_handle_dcd_change(struct uart_port
*uport
, unsigned int status
)
2971 struct tty_port
*port
= &uport
->state
->port
;
2972 struct tty_struct
*tty
= port
->tty
;
2973 struct tty_ldisc
*ld
;
2975 lockdep_assert_held_once(&uport
->lock
);
2978 ld
= tty_ldisc_ref(tty
);
2980 if (ld
->ops
->dcd_change
)
2981 ld
->ops
->dcd_change(tty
, status
);
2982 tty_ldisc_deref(ld
);
2986 uport
->icount
.dcd
++;
2988 if (uart_dcd_enabled(uport
)) {
2990 wake_up_interruptible(&port
->open_wait
);
2995 EXPORT_SYMBOL_GPL(uart_handle_dcd_change
);
2998 * uart_handle_cts_change - handle a change of clear-to-send state
2999 * @uport: uart_port structure for the open port
3000 * @status: new clear to send status, nonzero if active
3002 * Caller must hold uport->lock
3004 void uart_handle_cts_change(struct uart_port
*uport
, unsigned int status
)
3006 lockdep_assert_held_once(&uport
->lock
);
3008 uport
->icount
.cts
++;
3010 if (uart_softcts_mode(uport
)) {
3011 if (uport
->hw_stopped
) {
3013 uport
->hw_stopped
= 0;
3014 uport
->ops
->start_tx(uport
);
3015 uart_write_wakeup(uport
);
3019 uport
->hw_stopped
= 1;
3020 uport
->ops
->stop_tx(uport
);
3026 EXPORT_SYMBOL_GPL(uart_handle_cts_change
);
3029 * uart_insert_char - push a char to the uart layer
3031 * User is responsible to call tty_flip_buffer_push when they are done with
3034 * @port: corresponding port
3035 * @status: state of the serial port RX buffer (LSR for 8250)
3036 * @overrun: mask of overrun bits in @status
3037 * @ch: character to push
3038 * @flag: flag for the character (see TTY_NORMAL and friends)
3040 void uart_insert_char(struct uart_port
*port
, unsigned int status
,
3041 unsigned int overrun
, unsigned int ch
, unsigned int flag
)
3043 struct tty_port
*tport
= &port
->state
->port
;
3045 if ((status
& port
->ignore_status_mask
& ~overrun
) == 0)
3046 if (tty_insert_flip_char(tport
, ch
, flag
) == 0)
3047 ++port
->icount
.buf_overrun
;
3050 * Overrun is special. Since it's reported immediately,
3051 * it doesn't affect the current character.
3053 if (status
& ~port
->ignore_status_mask
& overrun
)
3054 if (tty_insert_flip_char(tport
, 0, TTY_OVERRUN
) == 0)
3055 ++port
->icount
.buf_overrun
;
3057 EXPORT_SYMBOL_GPL(uart_insert_char
);
3059 EXPORT_SYMBOL(uart_write_wakeup
);
3060 EXPORT_SYMBOL(uart_register_driver
);
3061 EXPORT_SYMBOL(uart_unregister_driver
);
3062 EXPORT_SYMBOL(uart_suspend_port
);
3063 EXPORT_SYMBOL(uart_resume_port
);
3064 EXPORT_SYMBOL(uart_add_one_port
);
3065 EXPORT_SYMBOL(uart_remove_one_port
);
3068 * uart_get_rs485_mode() - retrieve rs485 properties for given uart
3070 * @rs485conf: output parameter
3072 * This function implements the device tree binding described in
3073 * Documentation/devicetree/bindings/serial/rs485.txt.
3075 void uart_get_rs485_mode(struct device
*dev
, struct serial_rs485
*rs485conf
)
3080 ret
= device_property_read_u32_array(dev
, "rs485-rts-delay",
3083 rs485conf
->delay_rts_before_send
= rs485_delay
[0];
3084 rs485conf
->delay_rts_after_send
= rs485_delay
[1];
3086 rs485conf
->delay_rts_before_send
= 0;
3087 rs485conf
->delay_rts_after_send
= 0;
3091 * Clear full-duplex and enabled flags, set RTS polarity to active high
3092 * to get to a defined state with the following properties:
3094 rs485conf
->flags
&= ~(SER_RS485_RX_DURING_TX
| SER_RS485_ENABLED
|
3095 SER_RS485_RTS_AFTER_SEND
);
3096 rs485conf
->flags
|= SER_RS485_RTS_ON_SEND
;
3098 if (device_property_read_bool(dev
, "rs485-rx-during-tx"))
3099 rs485conf
->flags
|= SER_RS485_RX_DURING_TX
;
3101 if (device_property_read_bool(dev
, "linux,rs485-enabled-at-boot-time"))
3102 rs485conf
->flags
|= SER_RS485_ENABLED
;
3104 if (device_property_read_bool(dev
, "rs485-rts-active-low")) {
3105 rs485conf
->flags
&= ~SER_RS485_RTS_ON_SEND
;
3106 rs485conf
->flags
|= SER_RS485_RTS_AFTER_SEND
;
3109 EXPORT_SYMBOL_GPL(uart_get_rs485_mode
);
3111 MODULE_DESCRIPTION("Serial driver core");
3112 MODULE_LICENSE("GPL");