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
);
187 if (uport
->type
== PORT_UNKNOWN
)
191 * Make sure the device is in D0 state.
193 uart_change_pm(state
, UART_PM_STATE_ON
);
196 * Initialise and allocate the transmit and temporary
199 if (!state
->xmit
.buf
) {
200 /* This is protected by the per port mutex */
201 page
= get_zeroed_page(GFP_KERNEL
);
205 state
->xmit
.buf
= (unsigned char *) page
;
206 uart_circ_clear(&state
->xmit
);
209 retval
= uport
->ops
->startup(uport
);
211 if (uart_console(uport
) && uport
->cons
->cflag
) {
212 tty
->termios
.c_cflag
= uport
->cons
->cflag
;
213 uport
->cons
->cflag
= 0;
216 * Initialise the hardware port settings.
218 uart_change_speed(tty
, state
, NULL
);
221 * Setup the RTS and DTR signals once the
222 * port is open and ready to respond.
224 if (init_hw
&& C_BAUD(tty
))
225 uart_port_dtr_rts(uport
, 1);
229 * This is to allow setserial on this port. People may want to set
230 * port/irq/type and then reconfigure the port properly if it failed
233 if (retval
&& capable(CAP_SYS_ADMIN
))
239 static int uart_startup(struct tty_struct
*tty
, struct uart_state
*state
,
242 struct tty_port
*port
= &state
->port
;
245 if (tty_port_initialized(port
))
248 retval
= uart_port_startup(tty
, state
, init_hw
);
250 set_bit(TTY_IO_ERROR
, &tty
->flags
);
256 * This routine will shutdown a serial port; interrupts are disabled, and
257 * DTR is dropped if the hangup on close termio flag is on. Calls to
258 * uart_shutdown are serialised by the per-port semaphore.
260 * uport == NULL if uart_port has already been removed
262 static void uart_shutdown(struct tty_struct
*tty
, struct uart_state
*state
)
264 struct uart_port
*uport
= uart_port_check(state
);
265 struct tty_port
*port
= &state
->port
;
268 * Set the TTY IO error marker
271 set_bit(TTY_IO_ERROR
, &tty
->flags
);
273 if (tty_port_initialized(port
)) {
274 tty_port_set_initialized(port
, 0);
277 * Turn off DTR and RTS early.
279 if (uport
&& uart_console(uport
) && tty
)
280 uport
->cons
->cflag
= tty
->termios
.c_cflag
;
282 if (!tty
|| C_HUPCL(tty
))
283 uart_port_dtr_rts(uport
, 0);
285 uart_port_shutdown(port
);
289 * It's possible for shutdown to be called after suspend if we get
290 * a DCD drop (hangup) at just the right time. Clear suspended bit so
291 * we don't try to resume a port that has been shutdown.
293 tty_port_set_suspended(port
, 0);
296 * Free the transmit buffer page.
298 if (state
->xmit
.buf
) {
299 free_page((unsigned long)state
->xmit
.buf
);
300 state
->xmit
.buf
= NULL
;
305 * uart_update_timeout - update per-port FIFO timeout.
306 * @port: uart_port structure describing the port
307 * @cflag: termios cflag value
308 * @baud: speed of the port
310 * Set the port FIFO timeout value. The @cflag value should
311 * reflect the actual hardware settings.
314 uart_update_timeout(struct uart_port
*port
, unsigned int cflag
,
319 /* byte size and parity */
320 switch (cflag
& CSIZE
) {
341 * The total number of bits to be transmitted in the fifo.
343 bits
= bits
* port
->fifosize
;
346 * Figure the timeout to send the above number of bits.
347 * Add .02 seconds of slop
349 port
->timeout
= (HZ
* bits
) / baud
+ HZ
/50;
352 EXPORT_SYMBOL(uart_update_timeout
);
355 * uart_get_baud_rate - return baud rate for a particular port
356 * @port: uart_port structure describing the port in question.
357 * @termios: desired termios settings.
358 * @old: old termios (or NULL)
359 * @min: minimum acceptable baud rate
360 * @max: maximum acceptable baud rate
362 * Decode the termios structure into a numeric baud rate,
363 * taking account of the magic 38400 baud rate (with spd_*
364 * flags), and mapping the %B0 rate to 9600 baud.
366 * If the new baud rate is invalid, try the old termios setting.
367 * If it's still invalid, we try 9600 baud.
369 * Update the @termios structure to reflect the baud rate
370 * we're actually going to be using. Don't do this for the case
371 * where B0 is requested ("hang up").
374 uart_get_baud_rate(struct uart_port
*port
, struct ktermios
*termios
,
375 struct ktermios
*old
, unsigned int min
, unsigned int max
)
379 unsigned int altbaud
;
381 upf_t flags
= port
->flags
& UPF_SPD_MASK
;
401 for (try = 0; try < 2; try++) {
402 baud
= tty_termios_baud_rate(termios
);
405 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
408 if (try == 0 && baud
== 38400)
412 * Special case: B0 rate.
419 if (baud
>= min
&& baud
<= max
)
423 * Oops, the quotient was zero. Try again with
424 * the old baud rate if possible.
426 termios
->c_cflag
&= ~CBAUD
;
428 baud
= tty_termios_baud_rate(old
);
430 tty_termios_encode_baud_rate(termios
,
437 * As a last resort, if the range cannot be met then clip to
438 * the nearest chip supported rate.
442 tty_termios_encode_baud_rate(termios
,
445 tty_termios_encode_baud_rate(termios
,
449 /* Should never happen */
454 EXPORT_SYMBOL(uart_get_baud_rate
);
457 * uart_get_divisor - return uart clock divisor
458 * @port: uart_port structure describing the port.
459 * @baud: desired baud rate
461 * Calculate the uart clock divisor for the port.
464 uart_get_divisor(struct uart_port
*port
, unsigned int baud
)
469 * Old custom speed handling.
471 if (baud
== 38400 && (port
->flags
& UPF_SPD_MASK
) == UPF_SPD_CUST
)
472 quot
= port
->custom_divisor
;
474 quot
= DIV_ROUND_CLOSEST(port
->uartclk
, 16 * baud
);
479 EXPORT_SYMBOL(uart_get_divisor
);
481 /* Caller holds port mutex */
482 static void uart_change_speed(struct tty_struct
*tty
, struct uart_state
*state
,
483 struct ktermios
*old_termios
)
485 struct uart_port
*uport
= uart_port_check(state
);
486 struct ktermios
*termios
;
490 * If we have no tty, termios, or the port does not exist,
491 * then we can't set the parameters for this port.
493 if (!tty
|| uport
->type
== PORT_UNKNOWN
)
496 termios
= &tty
->termios
;
497 uport
->ops
->set_termios(uport
, termios
, old_termios
);
500 * Set modem status enables based on termios cflag
502 spin_lock_irq(&uport
->lock
);
503 if (termios
->c_cflag
& CRTSCTS
)
504 uport
->status
|= UPSTAT_CTS_ENABLE
;
506 uport
->status
&= ~UPSTAT_CTS_ENABLE
;
508 if (termios
->c_cflag
& CLOCAL
)
509 uport
->status
&= ~UPSTAT_DCD_ENABLE
;
511 uport
->status
|= UPSTAT_DCD_ENABLE
;
513 /* reset sw-assisted CTS flow control based on (possibly) new mode */
514 hw_stopped
= uport
->hw_stopped
;
515 uport
->hw_stopped
= uart_softcts_mode(uport
) &&
516 !(uport
->ops
->get_mctrl(uport
) & TIOCM_CTS
);
517 if (uport
->hw_stopped
) {
519 uport
->ops
->stop_tx(uport
);
524 spin_unlock_irq(&uport
->lock
);
527 static int uart_put_char(struct tty_struct
*tty
, unsigned char c
)
529 struct uart_state
*state
= tty
->driver_data
;
530 struct uart_port
*port
;
531 struct circ_buf
*circ
;
539 port
= uart_port_lock(state
, flags
);
540 if (port
&& uart_circ_chars_free(circ
) != 0) {
541 circ
->buf
[circ
->head
] = c
;
542 circ
->head
= (circ
->head
+ 1) & (UART_XMIT_SIZE
- 1);
545 uart_port_unlock(port
, flags
);
549 static void uart_flush_chars(struct tty_struct
*tty
)
554 static int uart_write(struct tty_struct
*tty
,
555 const unsigned char *buf
, int count
)
557 struct uart_state
*state
= tty
->driver_data
;
558 struct uart_port
*port
;
559 struct circ_buf
*circ
;
564 * This means you called this function _after_ the port was
565 * closed. No cookie for you.
576 port
= uart_port_lock(state
, flags
);
578 c
= CIRC_SPACE_TO_END(circ
->head
, circ
->tail
, UART_XMIT_SIZE
);
583 memcpy(circ
->buf
+ circ
->head
, buf
, c
);
584 circ
->head
= (circ
->head
+ c
) & (UART_XMIT_SIZE
- 1);
591 uart_port_unlock(port
, flags
);
595 static int uart_write_room(struct tty_struct
*tty
)
597 struct uart_state
*state
= tty
->driver_data
;
598 struct uart_port
*port
;
602 port
= uart_port_lock(state
, flags
);
603 ret
= uart_circ_chars_free(&state
->xmit
);
604 uart_port_unlock(port
, flags
);
608 static int uart_chars_in_buffer(struct tty_struct
*tty
)
610 struct uart_state
*state
= tty
->driver_data
;
611 struct uart_port
*port
;
615 port
= uart_port_lock(state
, flags
);
616 ret
= uart_circ_chars_pending(&state
->xmit
);
617 uart_port_unlock(port
, flags
);
621 static void uart_flush_buffer(struct tty_struct
*tty
)
623 struct uart_state
*state
= tty
->driver_data
;
624 struct uart_port
*port
;
628 * This means you called this function _after_ the port was
629 * closed. No cookie for you.
636 pr_debug("uart_flush_buffer(%d) called\n", tty
->index
);
638 port
= uart_port_lock(state
, flags
);
641 uart_circ_clear(&state
->xmit
);
642 if (port
->ops
->flush_buffer
)
643 port
->ops
->flush_buffer(port
);
644 uart_port_unlock(port
, flags
);
645 tty_port_tty_wakeup(&state
->port
);
649 * This function is used to send a high-priority XON/XOFF character to
652 static void uart_send_xchar(struct tty_struct
*tty
, char ch
)
654 struct uart_state
*state
= tty
->driver_data
;
655 struct uart_port
*port
;
658 port
= uart_port_ref(state
);
662 if (port
->ops
->send_xchar
)
663 port
->ops
->send_xchar(port
, ch
);
665 spin_lock_irqsave(&port
->lock
, flags
);
668 port
->ops
->start_tx(port
);
669 spin_unlock_irqrestore(&port
->lock
, flags
);
671 uart_port_deref(port
);
674 static void uart_throttle(struct tty_struct
*tty
)
676 struct uart_state
*state
= tty
->driver_data
;
677 struct uart_port
*port
;
680 port
= uart_port_ref(state
);
685 mask
|= UPSTAT_AUTOXOFF
;
687 mask
|= UPSTAT_AUTORTS
;
689 if (port
->status
& mask
) {
690 port
->ops
->throttle(port
);
691 mask
&= ~port
->status
;
694 if (mask
& UPSTAT_AUTORTS
)
695 uart_clear_mctrl(port
, TIOCM_RTS
);
697 if (mask
& UPSTAT_AUTOXOFF
)
698 uart_send_xchar(tty
, STOP_CHAR(tty
));
700 uart_port_deref(port
);
703 static void uart_unthrottle(struct tty_struct
*tty
)
705 struct uart_state
*state
= tty
->driver_data
;
706 struct uart_port
*port
;
709 port
= uart_port_ref(state
);
714 mask
|= UPSTAT_AUTOXOFF
;
716 mask
|= UPSTAT_AUTORTS
;
718 if (port
->status
& mask
) {
719 port
->ops
->unthrottle(port
);
720 mask
&= ~port
->status
;
723 if (mask
& UPSTAT_AUTORTS
)
724 uart_set_mctrl(port
, TIOCM_RTS
);
726 if (mask
& UPSTAT_AUTOXOFF
)
727 uart_send_xchar(tty
, START_CHAR(tty
));
729 uart_port_deref(port
);
732 static int uart_get_info(struct tty_port
*port
, struct serial_struct
*retinfo
)
734 struct uart_state
*state
= container_of(port
, struct uart_state
, port
);
735 struct uart_port
*uport
;
738 memset(retinfo
, 0, sizeof(*retinfo
));
741 * Ensure the state we copy is consistent and no hardware changes
744 mutex_lock(&port
->mutex
);
745 uport
= uart_port_check(state
);
749 retinfo
->type
= uport
->type
;
750 retinfo
->line
= uport
->line
;
751 retinfo
->port
= uport
->iobase
;
752 if (HIGH_BITS_OFFSET
)
753 retinfo
->port_high
= (long) uport
->iobase
>> HIGH_BITS_OFFSET
;
754 retinfo
->irq
= uport
->irq
;
755 retinfo
->flags
= (__force
int)uport
->flags
;
756 retinfo
->xmit_fifo_size
= uport
->fifosize
;
757 retinfo
->baud_base
= uport
->uartclk
/ 16;
758 retinfo
->close_delay
= jiffies_to_msecs(port
->close_delay
) / 10;
759 retinfo
->closing_wait
= port
->closing_wait
== ASYNC_CLOSING_WAIT_NONE
?
760 ASYNC_CLOSING_WAIT_NONE
:
761 jiffies_to_msecs(port
->closing_wait
) / 10;
762 retinfo
->custom_divisor
= uport
->custom_divisor
;
763 retinfo
->hub6
= uport
->hub6
;
764 retinfo
->io_type
= uport
->iotype
;
765 retinfo
->iomem_reg_shift
= uport
->regshift
;
766 retinfo
->iomem_base
= (void *)(unsigned long)uport
->mapbase
;
770 mutex_unlock(&port
->mutex
);
774 static int uart_get_info_user(struct tty_port
*port
,
775 struct serial_struct __user
*retinfo
)
777 struct serial_struct tmp
;
779 if (uart_get_info(port
, &tmp
) < 0)
782 if (copy_to_user(retinfo
, &tmp
, sizeof(*retinfo
)))
787 static int uart_set_info(struct tty_struct
*tty
, struct tty_port
*port
,
788 struct uart_state
*state
,
789 struct serial_struct
*new_info
)
791 struct uart_port
*uport
= uart_port_check(state
);
792 unsigned long new_port
;
793 unsigned int change_irq
, change_port
, closing_wait
;
794 unsigned int old_custom_divisor
, close_delay
;
795 upf_t old_flags
, new_flags
;
801 new_port
= new_info
->port
;
802 if (HIGH_BITS_OFFSET
)
803 new_port
+= (unsigned long) new_info
->port_high
<< HIGH_BITS_OFFSET
;
805 new_info
->irq
= irq_canonicalize(new_info
->irq
);
806 close_delay
= msecs_to_jiffies(new_info
->close_delay
* 10);
807 closing_wait
= new_info
->closing_wait
== ASYNC_CLOSING_WAIT_NONE
?
808 ASYNC_CLOSING_WAIT_NONE
:
809 msecs_to_jiffies(new_info
->closing_wait
* 10);
812 change_irq
= !(uport
->flags
& UPF_FIXED_PORT
)
813 && new_info
->irq
!= uport
->irq
;
816 * Since changing the 'type' of the port changes its resource
817 * allocations, we should treat type changes the same as
820 change_port
= !(uport
->flags
& UPF_FIXED_PORT
)
821 && (new_port
!= uport
->iobase
||
822 (unsigned long)new_info
->iomem_base
!= uport
->mapbase
||
823 new_info
->hub6
!= uport
->hub6
||
824 new_info
->io_type
!= uport
->iotype
||
825 new_info
->iomem_reg_shift
!= uport
->regshift
||
826 new_info
->type
!= uport
->type
);
828 old_flags
= uport
->flags
;
829 new_flags
= (__force upf_t
)new_info
->flags
;
830 old_custom_divisor
= uport
->custom_divisor
;
832 if (!capable(CAP_SYS_ADMIN
)) {
834 if (change_irq
|| change_port
||
835 (new_info
->baud_base
!= uport
->uartclk
/ 16) ||
836 (close_delay
!= port
->close_delay
) ||
837 (closing_wait
!= port
->closing_wait
) ||
838 (new_info
->xmit_fifo_size
&&
839 new_info
->xmit_fifo_size
!= uport
->fifosize
) ||
840 (((new_flags
^ old_flags
) & ~UPF_USR_MASK
) != 0))
842 uport
->flags
= ((uport
->flags
& ~UPF_USR_MASK
) |
843 (new_flags
& UPF_USR_MASK
));
844 uport
->custom_divisor
= new_info
->custom_divisor
;
849 * Ask the low level driver to verify the settings.
851 if (uport
->ops
->verify_port
)
852 retval
= uport
->ops
->verify_port(uport
, new_info
);
854 if ((new_info
->irq
>= nr_irqs
) || (new_info
->irq
< 0) ||
855 (new_info
->baud_base
< 9600))
861 if (change_port
|| change_irq
) {
865 * Make sure that we are the sole user of this port.
867 if (tty_port_users(port
) > 1)
871 * We need to shutdown the serial port at the old
872 * port/type/irq combination.
874 uart_shutdown(tty
, state
);
878 unsigned long old_iobase
, old_mapbase
;
879 unsigned int old_type
, old_iotype
, old_hub6
, old_shift
;
881 old_iobase
= uport
->iobase
;
882 old_mapbase
= uport
->mapbase
;
883 old_type
= uport
->type
;
884 old_hub6
= uport
->hub6
;
885 old_iotype
= uport
->iotype
;
886 old_shift
= uport
->regshift
;
889 * Free and release old regions
891 if (old_type
!= PORT_UNKNOWN
&& uport
->ops
->release_port
)
892 uport
->ops
->release_port(uport
);
894 uport
->iobase
= new_port
;
895 uport
->type
= new_info
->type
;
896 uport
->hub6
= new_info
->hub6
;
897 uport
->iotype
= new_info
->io_type
;
898 uport
->regshift
= new_info
->iomem_reg_shift
;
899 uport
->mapbase
= (unsigned long)new_info
->iomem_base
;
902 * Claim and map the new regions
904 if (uport
->type
!= PORT_UNKNOWN
&& uport
->ops
->request_port
) {
905 retval
= uport
->ops
->request_port(uport
);
907 /* Always success - Jean II */
912 * If we fail to request resources for the
913 * new port, try to restore the old settings.
916 uport
->iobase
= old_iobase
;
917 uport
->type
= old_type
;
918 uport
->hub6
= old_hub6
;
919 uport
->iotype
= old_iotype
;
920 uport
->regshift
= old_shift
;
921 uport
->mapbase
= old_mapbase
;
923 if (old_type
!= PORT_UNKNOWN
) {
924 retval
= uport
->ops
->request_port(uport
);
926 * If we failed to restore the old settings,
930 uport
->type
= PORT_UNKNOWN
;
938 /* Added to return the correct error -Ram Gupta */
944 uport
->irq
= new_info
->irq
;
945 if (!(uport
->flags
& UPF_FIXED_PORT
))
946 uport
->uartclk
= new_info
->baud_base
* 16;
947 uport
->flags
= (uport
->flags
& ~UPF_CHANGE_MASK
) |
948 (new_flags
& UPF_CHANGE_MASK
);
949 uport
->custom_divisor
= new_info
->custom_divisor
;
950 port
->close_delay
= close_delay
;
951 port
->closing_wait
= closing_wait
;
952 if (new_info
->xmit_fifo_size
)
953 uport
->fifosize
= new_info
->xmit_fifo_size
;
954 port
->low_latency
= (uport
->flags
& UPF_LOW_LATENCY
) ? 1 : 0;
958 if (uport
->type
== PORT_UNKNOWN
)
960 if (tty_port_initialized(port
)) {
961 if (((old_flags
^ uport
->flags
) & UPF_SPD_MASK
) ||
962 old_custom_divisor
!= uport
->custom_divisor
) {
964 * If they're setting up a custom divisor or speed,
965 * instead of clearing it, then bitch about it.
967 if (uport
->flags
& UPF_SPD_MASK
) {
968 dev_notice_ratelimited(uport
->dev
,
969 "%s sets custom speed on %s. This is deprecated.\n",
971 tty_name(port
->tty
));
973 uart_change_speed(tty
, state
, NULL
);
976 retval
= uart_startup(tty
, state
, 1);
984 static int uart_set_info_user(struct tty_struct
*tty
, struct uart_state
*state
,
985 struct serial_struct __user
*newinfo
)
987 struct serial_struct new_serial
;
988 struct tty_port
*port
= &state
->port
;
991 if (copy_from_user(&new_serial
, newinfo
, sizeof(new_serial
)))
995 * This semaphore protects port->count. It is also
996 * very useful to prevent opens. Also, take the
997 * port configuration semaphore to make sure that a
998 * module insertion/removal doesn't change anything
1001 mutex_lock(&port
->mutex
);
1002 retval
= uart_set_info(tty
, port
, state
, &new_serial
);
1003 mutex_unlock(&port
->mutex
);
1008 * uart_get_lsr_info - get line status register info
1009 * @tty: tty associated with the UART
1010 * @state: UART being queried
1011 * @value: returned modem value
1013 static int uart_get_lsr_info(struct tty_struct
*tty
,
1014 struct uart_state
*state
, unsigned int __user
*value
)
1016 struct uart_port
*uport
= uart_port_check(state
);
1017 unsigned int result
;
1019 result
= uport
->ops
->tx_empty(uport
);
1022 * If we're about to load something into the transmit
1023 * register, we'll pretend the transmitter isn't empty to
1024 * avoid a race condition (depending on when the transmit
1025 * interrupt happens).
1027 if (uport
->x_char
||
1028 ((uart_circ_chars_pending(&state
->xmit
) > 0) &&
1029 !uart_tx_stopped(uport
)))
1030 result
&= ~TIOCSER_TEMT
;
1032 return put_user(result
, value
);
1035 static int uart_tiocmget(struct tty_struct
*tty
)
1037 struct uart_state
*state
= tty
->driver_data
;
1038 struct tty_port
*port
= &state
->port
;
1039 struct uart_port
*uport
;
1042 mutex_lock(&port
->mutex
);
1043 uport
= uart_port_check(state
);
1047 if (!tty_io_error(tty
)) {
1048 result
= uport
->mctrl
;
1049 spin_lock_irq(&uport
->lock
);
1050 result
|= uport
->ops
->get_mctrl(uport
);
1051 spin_unlock_irq(&uport
->lock
);
1054 mutex_unlock(&port
->mutex
);
1059 uart_tiocmset(struct tty_struct
*tty
, unsigned int set
, unsigned int clear
)
1061 struct uart_state
*state
= tty
->driver_data
;
1062 struct tty_port
*port
= &state
->port
;
1063 struct uart_port
*uport
;
1066 mutex_lock(&port
->mutex
);
1067 uport
= uart_port_check(state
);
1071 if (!tty_io_error(tty
)) {
1072 uart_update_mctrl(uport
, set
, clear
);
1076 mutex_unlock(&port
->mutex
);
1080 static int uart_break_ctl(struct tty_struct
*tty
, int break_state
)
1082 struct uart_state
*state
= tty
->driver_data
;
1083 struct tty_port
*port
= &state
->port
;
1084 struct uart_port
*uport
;
1087 mutex_lock(&port
->mutex
);
1088 uport
= uart_port_check(state
);
1092 if (uport
->type
!= PORT_UNKNOWN
)
1093 uport
->ops
->break_ctl(uport
, break_state
);
1096 mutex_unlock(&port
->mutex
);
1100 static int uart_do_autoconfig(struct tty_struct
*tty
,struct uart_state
*state
)
1102 struct tty_port
*port
= &state
->port
;
1103 struct uart_port
*uport
;
1106 if (!capable(CAP_SYS_ADMIN
))
1110 * Take the per-port semaphore. This prevents count from
1111 * changing, and hence any extra opens of the port while
1112 * we're auto-configuring.
1114 if (mutex_lock_interruptible(&port
->mutex
))
1115 return -ERESTARTSYS
;
1117 uport
= uart_port_check(state
);
1124 if (tty_port_users(port
) == 1) {
1125 uart_shutdown(tty
, state
);
1128 * If we already have a port type configured,
1129 * we must release its resources.
1131 if (uport
->type
!= PORT_UNKNOWN
&& uport
->ops
->release_port
)
1132 uport
->ops
->release_port(uport
);
1134 flags
= UART_CONFIG_TYPE
;
1135 if (uport
->flags
& UPF_AUTO_IRQ
)
1136 flags
|= UART_CONFIG_IRQ
;
1139 * This will claim the ports resources if
1142 uport
->ops
->config_port(uport
, flags
);
1144 ret
= uart_startup(tty
, state
, 1);
1149 mutex_unlock(&port
->mutex
);
1153 static void uart_enable_ms(struct uart_port
*uport
)
1156 * Force modem status interrupts on
1158 if (uport
->ops
->enable_ms
)
1159 uport
->ops
->enable_ms(uport
);
1163 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1164 * - mask passed in arg for lines of interest
1165 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1166 * Caller should use TIOCGICOUNT to see which one it was
1168 * FIXME: This wants extracting into a common all driver implementation
1169 * of TIOCMWAIT using tty_port.
1171 static int uart_wait_modem_status(struct uart_state
*state
, unsigned long arg
)
1173 struct uart_port
*uport
;
1174 struct tty_port
*port
= &state
->port
;
1175 DECLARE_WAITQUEUE(wait
, current
);
1176 struct uart_icount cprev
, cnow
;
1180 * note the counters on entry
1182 uport
= uart_port_ref(state
);
1185 spin_lock_irq(&uport
->lock
);
1186 memcpy(&cprev
, &uport
->icount
, sizeof(struct uart_icount
));
1187 uart_enable_ms(uport
);
1188 spin_unlock_irq(&uport
->lock
);
1190 add_wait_queue(&port
->delta_msr_wait
, &wait
);
1192 spin_lock_irq(&uport
->lock
);
1193 memcpy(&cnow
, &uport
->icount
, sizeof(struct uart_icount
));
1194 spin_unlock_irq(&uport
->lock
);
1196 set_current_state(TASK_INTERRUPTIBLE
);
1198 if (((arg
& TIOCM_RNG
) && (cnow
.rng
!= cprev
.rng
)) ||
1199 ((arg
& TIOCM_DSR
) && (cnow
.dsr
!= cprev
.dsr
)) ||
1200 ((arg
& TIOCM_CD
) && (cnow
.dcd
!= cprev
.dcd
)) ||
1201 ((arg
& TIOCM_CTS
) && (cnow
.cts
!= cprev
.cts
))) {
1208 /* see if a signal did it */
1209 if (signal_pending(current
)) {
1216 __set_current_state(TASK_RUNNING
);
1217 remove_wait_queue(&port
->delta_msr_wait
, &wait
);
1218 uart_port_deref(uport
);
1224 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1225 * Return: write counters to the user passed counter struct
1226 * NB: both 1->0 and 0->1 transitions are counted except for
1227 * RI where only 0->1 is counted.
1229 static int uart_get_icount(struct tty_struct
*tty
,
1230 struct serial_icounter_struct
*icount
)
1232 struct uart_state
*state
= tty
->driver_data
;
1233 struct uart_icount cnow
;
1234 struct uart_port
*uport
;
1236 uport
= uart_port_ref(state
);
1239 spin_lock_irq(&uport
->lock
);
1240 memcpy(&cnow
, &uport
->icount
, sizeof(struct uart_icount
));
1241 spin_unlock_irq(&uport
->lock
);
1242 uart_port_deref(uport
);
1244 icount
->cts
= cnow
.cts
;
1245 icount
->dsr
= cnow
.dsr
;
1246 icount
->rng
= cnow
.rng
;
1247 icount
->dcd
= cnow
.dcd
;
1248 icount
->rx
= cnow
.rx
;
1249 icount
->tx
= cnow
.tx
;
1250 icount
->frame
= cnow
.frame
;
1251 icount
->overrun
= cnow
.overrun
;
1252 icount
->parity
= cnow
.parity
;
1253 icount
->brk
= cnow
.brk
;
1254 icount
->buf_overrun
= cnow
.buf_overrun
;
1259 static int uart_get_rs485_config(struct uart_port
*port
,
1260 struct serial_rs485 __user
*rs485
)
1262 unsigned long flags
;
1263 struct serial_rs485 aux
;
1265 spin_lock_irqsave(&port
->lock
, flags
);
1267 spin_unlock_irqrestore(&port
->lock
, flags
);
1269 if (copy_to_user(rs485
, &aux
, sizeof(aux
)))
1275 static int uart_set_rs485_config(struct uart_port
*port
,
1276 struct serial_rs485 __user
*rs485_user
)
1278 struct serial_rs485 rs485
;
1280 unsigned long flags
;
1282 if (!port
->rs485_config
)
1283 return -ENOIOCTLCMD
;
1285 if (copy_from_user(&rs485
, rs485_user
, sizeof(*rs485_user
)))
1288 spin_lock_irqsave(&port
->lock
, flags
);
1289 ret
= port
->rs485_config(port
, &rs485
);
1290 spin_unlock_irqrestore(&port
->lock
, flags
);
1294 if (copy_to_user(rs485_user
, &port
->rs485
, sizeof(port
->rs485
)))
1301 * Called via sys_ioctl. We can use spin_lock_irq() here.
1304 uart_ioctl(struct tty_struct
*tty
, unsigned int cmd
, unsigned long arg
)
1306 struct uart_state
*state
= tty
->driver_data
;
1307 struct tty_port
*port
= &state
->port
;
1308 struct uart_port
*uport
;
1309 void __user
*uarg
= (void __user
*)arg
;
1310 int ret
= -ENOIOCTLCMD
;
1314 * These ioctls don't rely on the hardware to be present.
1318 ret
= uart_get_info_user(port
, uarg
);
1322 down_write(&tty
->termios_rwsem
);
1323 ret
= uart_set_info_user(tty
, state
, uarg
);
1324 up_write(&tty
->termios_rwsem
);
1328 down_write(&tty
->termios_rwsem
);
1329 ret
= uart_do_autoconfig(tty
, state
);
1330 up_write(&tty
->termios_rwsem
);
1333 case TIOCSERGWILD
: /* obsolete */
1334 case TIOCSERSWILD
: /* obsolete */
1339 if (ret
!= -ENOIOCTLCMD
)
1342 if (tty_io_error(tty
)) {
1348 * The following should only be used when hardware is present.
1352 ret
= uart_wait_modem_status(state
, arg
);
1356 if (ret
!= -ENOIOCTLCMD
)
1359 mutex_lock(&port
->mutex
);
1360 uport
= uart_port_check(state
);
1362 if (!uport
|| tty_io_error(tty
)) {
1368 * All these rely on hardware being present and need to be
1369 * protected against the tty being hung up.
1373 case TIOCSERGETLSR
: /* Get line status register */
1374 ret
= uart_get_lsr_info(tty
, state
, uarg
);
1378 ret
= uart_get_rs485_config(uport
, uarg
);
1382 ret
= uart_set_rs485_config(uport
, uarg
);
1385 if (uport
->ops
->ioctl
)
1386 ret
= uport
->ops
->ioctl(uport
, cmd
, arg
);
1390 mutex_unlock(&port
->mutex
);
1395 static void uart_set_ldisc(struct tty_struct
*tty
)
1397 struct uart_state
*state
= tty
->driver_data
;
1398 struct uart_port
*uport
;
1400 mutex_lock(&state
->port
.mutex
);
1401 uport
= uart_port_check(state
);
1402 if (uport
&& uport
->ops
->set_ldisc
)
1403 uport
->ops
->set_ldisc(uport
, &tty
->termios
);
1404 mutex_unlock(&state
->port
.mutex
);
1407 static void uart_set_termios(struct tty_struct
*tty
,
1408 struct ktermios
*old_termios
)
1410 struct uart_state
*state
= tty
->driver_data
;
1411 struct uart_port
*uport
;
1412 unsigned int cflag
= tty
->termios
.c_cflag
;
1413 unsigned int iflag_mask
= IGNBRK
|BRKINT
|IGNPAR
|PARMRK
|INPCK
;
1414 bool sw_changed
= false;
1416 mutex_lock(&state
->port
.mutex
);
1417 uport
= uart_port_check(state
);
1422 * Drivers doing software flow control also need to know
1423 * about changes to these input settings.
1425 if (uport
->flags
& UPF_SOFT_FLOW
) {
1426 iflag_mask
|= IXANY
|IXON
|IXOFF
;
1428 tty
->termios
.c_cc
[VSTART
] != old_termios
->c_cc
[VSTART
] ||
1429 tty
->termios
.c_cc
[VSTOP
] != old_termios
->c_cc
[VSTOP
];
1433 * These are the bits that are used to setup various
1434 * flags in the low level driver. We can ignore the Bfoo
1435 * bits in c_cflag; c_[io]speed will always be set
1436 * appropriately by set_termios() in tty_ioctl.c
1438 if ((cflag
^ old_termios
->c_cflag
) == 0 &&
1439 tty
->termios
.c_ospeed
== old_termios
->c_ospeed
&&
1440 tty
->termios
.c_ispeed
== old_termios
->c_ispeed
&&
1441 ((tty
->termios
.c_iflag
^ old_termios
->c_iflag
) & iflag_mask
) == 0 &&
1446 uart_change_speed(tty
, state
, old_termios
);
1447 /* reload cflag from termios; port driver may have overriden flags */
1448 cflag
= tty
->termios
.c_cflag
;
1450 /* Handle transition to B0 status */
1451 if ((old_termios
->c_cflag
& CBAUD
) && !(cflag
& CBAUD
))
1452 uart_clear_mctrl(uport
, TIOCM_RTS
| TIOCM_DTR
);
1453 /* Handle transition away from B0 status */
1454 else if (!(old_termios
->c_cflag
& CBAUD
) && (cflag
& CBAUD
)) {
1455 unsigned int mask
= TIOCM_DTR
;
1456 if (!(cflag
& CRTSCTS
) || !tty_throttled(tty
))
1458 uart_set_mctrl(uport
, mask
);
1461 mutex_unlock(&state
->port
.mutex
);
1465 * Calls to uart_close() are serialised via the tty_lock in
1466 * drivers/tty/tty_io.c:tty_release()
1467 * drivers/tty/tty_io.c:do_tty_hangup()
1469 static void uart_close(struct tty_struct
*tty
, struct file
*filp
)
1471 struct uart_state
*state
= tty
->driver_data
;
1474 struct uart_driver
*drv
= tty
->driver
->driver_state
;
1475 struct tty_port
*port
;
1477 state
= drv
->state
+ tty
->index
;
1478 port
= &state
->port
;
1479 spin_lock_irq(&port
->lock
);
1481 spin_unlock_irq(&port
->lock
);
1485 pr_debug("uart_close(%d) called\n", tty
->index
);
1487 tty_port_close(tty
->port
, tty
, filp
);
1490 static void uart_tty_port_shutdown(struct tty_port
*port
)
1492 struct uart_state
*state
= container_of(port
, struct uart_state
, port
);
1493 struct uart_port
*uport
= uart_port_check(state
);
1496 * At this point, we stop accepting input. To do this, we
1497 * disable the receive line status interrupts.
1499 if (WARN(!uport
, "detached port still initialized!\n"))
1502 spin_lock_irq(&uport
->lock
);
1503 uport
->ops
->stop_rx(uport
);
1504 spin_unlock_irq(&uport
->lock
);
1506 uart_port_shutdown(port
);
1509 * It's possible for shutdown to be called after suspend if we get
1510 * a DCD drop (hangup) at just the right time. Clear suspended bit so
1511 * we don't try to resume a port that has been shutdown.
1513 tty_port_set_suspended(port
, 0);
1515 uart_change_pm(state
, UART_PM_STATE_OFF
);
1519 static void uart_wait_until_sent(struct tty_struct
*tty
, int timeout
)
1521 struct uart_state
*state
= tty
->driver_data
;
1522 struct uart_port
*port
;
1523 unsigned long char_time
, expire
;
1525 port
= uart_port_ref(state
);
1529 if (port
->type
== PORT_UNKNOWN
|| port
->fifosize
== 0) {
1530 uart_port_deref(port
);
1535 * Set the check interval to be 1/5 of the estimated time to
1536 * send a single character, and make it at least 1. The check
1537 * interval should also be less than the timeout.
1539 * Note: we have to use pretty tight timings here to satisfy
1542 char_time
= (port
->timeout
- HZ
/50) / port
->fifosize
;
1543 char_time
= char_time
/ 5;
1546 if (timeout
&& timeout
< char_time
)
1547 char_time
= timeout
;
1550 * If the transmitter hasn't cleared in twice the approximate
1551 * amount of time to send the entire FIFO, it probably won't
1552 * ever clear. This assumes the UART isn't doing flow
1553 * control, which is currently the case. Hence, if it ever
1554 * takes longer than port->timeout, this is probably due to a
1555 * UART bug of some kind. So, we clamp the timeout parameter at
1558 if (timeout
== 0 || timeout
> 2 * port
->timeout
)
1559 timeout
= 2 * port
->timeout
;
1561 expire
= jiffies
+ timeout
;
1563 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1564 port
->line
, jiffies
, expire
);
1567 * Check whether the transmitter is empty every 'char_time'.
1568 * 'timeout' / 'expire' give us the maximum amount of time
1571 while (!port
->ops
->tx_empty(port
)) {
1572 msleep_interruptible(jiffies_to_msecs(char_time
));
1573 if (signal_pending(current
))
1575 if (time_after(jiffies
, expire
))
1578 uart_port_deref(port
);
1582 * Calls to uart_hangup() are serialised by the tty_lock in
1583 * drivers/tty/tty_io.c:do_tty_hangup()
1584 * This runs from a workqueue and can sleep for a _short_ time only.
1586 static void uart_hangup(struct tty_struct
*tty
)
1588 struct uart_state
*state
= tty
->driver_data
;
1589 struct tty_port
*port
= &state
->port
;
1590 struct uart_port
*uport
;
1591 unsigned long flags
;
1593 pr_debug("uart_hangup(%d)\n", tty
->index
);
1595 mutex_lock(&port
->mutex
);
1596 uport
= uart_port_check(state
);
1597 WARN(!uport
, "hangup of detached port!\n");
1599 if (tty_port_active(port
)) {
1600 uart_flush_buffer(tty
);
1601 uart_shutdown(tty
, state
);
1602 spin_lock_irqsave(&port
->lock
, flags
);
1604 spin_unlock_irqrestore(&port
->lock
, flags
);
1605 tty_port_set_active(port
, 0);
1606 tty_port_tty_set(port
, NULL
);
1607 if (uport
&& !uart_console(uport
))
1608 uart_change_pm(state
, UART_PM_STATE_OFF
);
1609 wake_up_interruptible(&port
->open_wait
);
1610 wake_up_interruptible(&port
->delta_msr_wait
);
1612 mutex_unlock(&port
->mutex
);
1615 /* uport == NULL if uart_port has already been removed */
1616 static void uart_port_shutdown(struct tty_port
*port
)
1618 struct uart_state
*state
= container_of(port
, struct uart_state
, port
);
1619 struct uart_port
*uport
= uart_port_check(state
);
1622 * clear delta_msr_wait queue to avoid mem leaks: we may free
1623 * the irq here so the queue might never be woken up. Note
1624 * that we won't end up waiting on delta_msr_wait again since
1625 * any outstanding file descriptors should be pointing at
1626 * hung_up_tty_fops now.
1628 wake_up_interruptible(&port
->delta_msr_wait
);
1631 * Free the IRQ and disable the port.
1634 uport
->ops
->shutdown(uport
);
1637 * Ensure that the IRQ handler isn't running on another CPU.
1640 synchronize_irq(uport
->irq
);
1643 static int uart_carrier_raised(struct tty_port
*port
)
1645 struct uart_state
*state
= container_of(port
, struct uart_state
, port
);
1646 struct uart_port
*uport
;
1649 uport
= uart_port_ref(state
);
1651 * Should never observe uport == NULL since checks for hangup should
1652 * abort the tty_port_block_til_ready() loop before checking for carrier
1653 * raised -- but report carrier raised if it does anyway so open will
1654 * continue and not sleep
1656 if (WARN_ON(!uport
))
1658 spin_lock_irq(&uport
->lock
);
1659 uart_enable_ms(uport
);
1660 mctrl
= uport
->ops
->get_mctrl(uport
);
1661 spin_unlock_irq(&uport
->lock
);
1662 uart_port_deref(uport
);
1663 if (mctrl
& TIOCM_CAR
)
1668 static void uart_dtr_rts(struct tty_port
*port
, int raise
)
1670 struct uart_state
*state
= container_of(port
, struct uart_state
, port
);
1671 struct uart_port
*uport
;
1673 uport
= uart_port_ref(state
);
1676 uart_port_dtr_rts(uport
, raise
);
1677 uart_port_deref(uport
);
1681 * Calls to uart_open are serialised by the tty_lock in
1682 * drivers/tty/tty_io.c:tty_open()
1683 * Note that if this fails, then uart_close() _will_ be called.
1685 * In time, we want to scrap the "opening nonpresent ports"
1686 * behaviour and implement an alternative way for setserial
1687 * to set base addresses/ports/types. This will allow us to
1688 * get rid of a certain amount of extra tests.
1690 static int uart_open(struct tty_struct
*tty
, struct file
*filp
)
1692 struct uart_driver
*drv
= tty
->driver
->driver_state
;
1693 int retval
, line
= tty
->index
;
1694 struct uart_state
*state
= drv
->state
+ line
;
1696 tty
->driver_data
= state
;
1698 retval
= tty_port_open(&state
->port
, tty
, filp
);
1705 static int uart_port_activate(struct tty_port
*port
, struct tty_struct
*tty
)
1707 struct uart_state
*state
= container_of(port
, struct uart_state
, port
);
1708 struct uart_port
*uport
;
1710 uport
= uart_port_check(state
);
1711 if (!uport
|| uport
->flags
& UPF_DEAD
)
1714 port
->low_latency
= (uport
->flags
& UPF_LOW_LATENCY
) ? 1 : 0;
1717 * Start up the serial port.
1719 return uart_startup(tty
, state
, 0);
1722 static const char *uart_type(struct uart_port
*port
)
1724 const char *str
= NULL
;
1726 if (port
->ops
->type
)
1727 str
= port
->ops
->type(port
);
1735 #ifdef CONFIG_PROC_FS
1737 static void uart_line_info(struct seq_file
*m
, struct uart_driver
*drv
, int i
)
1739 struct uart_state
*state
= drv
->state
+ i
;
1740 struct tty_port
*port
= &state
->port
;
1741 enum uart_pm_state pm_state
;
1742 struct uart_port
*uport
;
1744 unsigned int status
;
1747 mutex_lock(&port
->mutex
);
1748 uport
= uart_port_check(state
);
1752 mmio
= uport
->iotype
>= UPIO_MEM
;
1753 seq_printf(m
, "%d: uart:%s %s%08llX irq:%d",
1754 uport
->line
, uart_type(uport
),
1755 mmio
? "mmio:0x" : "port:",
1756 mmio
? (unsigned long long)uport
->mapbase
1757 : (unsigned long long)uport
->iobase
,
1760 if (uport
->type
== PORT_UNKNOWN
) {
1765 if (capable(CAP_SYS_ADMIN
)) {
1766 pm_state
= state
->pm_state
;
1767 if (pm_state
!= UART_PM_STATE_ON
)
1768 uart_change_pm(state
, UART_PM_STATE_ON
);
1769 spin_lock_irq(&uport
->lock
);
1770 status
= uport
->ops
->get_mctrl(uport
);
1771 spin_unlock_irq(&uport
->lock
);
1772 if (pm_state
!= UART_PM_STATE_ON
)
1773 uart_change_pm(state
, pm_state
);
1775 seq_printf(m
, " tx:%d rx:%d",
1776 uport
->icount
.tx
, uport
->icount
.rx
);
1777 if (uport
->icount
.frame
)
1778 seq_printf(m
, " fe:%d", uport
->icount
.frame
);
1779 if (uport
->icount
.parity
)
1780 seq_printf(m
, " pe:%d", uport
->icount
.parity
);
1781 if (uport
->icount
.brk
)
1782 seq_printf(m
, " brk:%d", uport
->icount
.brk
);
1783 if (uport
->icount
.overrun
)
1784 seq_printf(m
, " oe:%d", uport
->icount
.overrun
);
1786 #define INFOBIT(bit, str) \
1787 if (uport->mctrl & (bit)) \
1788 strncat(stat_buf, (str), sizeof(stat_buf) - \
1789 strlen(stat_buf) - 2)
1790 #define STATBIT(bit, str) \
1791 if (status & (bit)) \
1792 strncat(stat_buf, (str), sizeof(stat_buf) - \
1793 strlen(stat_buf) - 2)
1797 INFOBIT(TIOCM_RTS
, "|RTS");
1798 STATBIT(TIOCM_CTS
, "|CTS");
1799 INFOBIT(TIOCM_DTR
, "|DTR");
1800 STATBIT(TIOCM_DSR
, "|DSR");
1801 STATBIT(TIOCM_CAR
, "|CD");
1802 STATBIT(TIOCM_RNG
, "|RI");
1806 seq_puts(m
, stat_buf
);
1812 mutex_unlock(&port
->mutex
);
1815 static int uart_proc_show(struct seq_file
*m
, void *v
)
1817 struct tty_driver
*ttydrv
= m
->private;
1818 struct uart_driver
*drv
= ttydrv
->driver_state
;
1821 seq_printf(m
, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
1822 for (i
= 0; i
< drv
->nr
; i
++)
1823 uart_line_info(m
, drv
, i
);
1827 static int uart_proc_open(struct inode
*inode
, struct file
*file
)
1829 return single_open(file
, uart_proc_show
, PDE_DATA(inode
));
1832 static const struct file_operations uart_proc_fops
= {
1833 .owner
= THIS_MODULE
,
1834 .open
= uart_proc_open
,
1836 .llseek
= seq_lseek
,
1837 .release
= single_release
,
1841 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1843 * uart_console_write - write a console message to a serial port
1844 * @port: the port to write the message
1845 * @s: array of characters
1846 * @count: number of characters in string to write
1847 * @putchar: function to write character to port
1849 void uart_console_write(struct uart_port
*port
, const char *s
,
1851 void (*putchar
)(struct uart_port
*, int))
1855 for (i
= 0; i
< count
; i
++, s
++) {
1857 putchar(port
, '\r');
1861 EXPORT_SYMBOL_GPL(uart_console_write
);
1864 * Check whether an invalid uart number has been specified, and
1865 * if so, search for the first available port that does have
1868 struct uart_port
* __init
1869 uart_get_console(struct uart_port
*ports
, int nr
, struct console
*co
)
1871 int idx
= co
->index
;
1873 if (idx
< 0 || idx
>= nr
|| (ports
[idx
].iobase
== 0 &&
1874 ports
[idx
].membase
== NULL
))
1875 for (idx
= 0; idx
< nr
; idx
++)
1876 if (ports
[idx
].iobase
!= 0 ||
1877 ports
[idx
].membase
!= NULL
)
1886 * uart_parse_earlycon - Parse earlycon options
1887 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1888 * @iotype: ptr for decoded iotype (out)
1889 * @addr: ptr for decoded mapbase/iobase (out)
1890 * @options: ptr for <options> field; NULL if not present (out)
1892 * Decodes earlycon kernel command line parameters of the form
1893 * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1894 * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1897 * earlycon=<name>,0x<addr>,<options>
1898 * console=<name>,0x<addr>,<options>
1899 * is also accepted; the returned @iotype will be UPIO_MEM.
1901 * Returns 0 on success or -EINVAL on failure
1903 int uart_parse_earlycon(char *p
, unsigned char *iotype
, resource_size_t
*addr
,
1906 if (strncmp(p
, "mmio,", 5) == 0) {
1909 } else if (strncmp(p
, "mmio16,", 7) == 0) {
1910 *iotype
= UPIO_MEM16
;
1912 } else if (strncmp(p
, "mmio32,", 7) == 0) {
1913 *iotype
= UPIO_MEM32
;
1915 } else if (strncmp(p
, "mmio32be,", 9) == 0) {
1916 *iotype
= UPIO_MEM32BE
;
1918 } else if (strncmp(p
, "mmio32native,", 13) == 0) {
1919 *iotype
= IS_ENABLED(CONFIG_CPU_BIG_ENDIAN
) ?
1920 UPIO_MEM32BE
: UPIO_MEM32
;
1922 } else if (strncmp(p
, "io,", 3) == 0) {
1923 *iotype
= UPIO_PORT
;
1925 } else if (strncmp(p
, "0x", 2) == 0) {
1932 * Before you replace it with kstrtoull(), think about options separator
1933 * (',') it will not tolerate
1935 *addr
= simple_strtoull(p
, NULL
, 0);
1943 EXPORT_SYMBOL_GPL(uart_parse_earlycon
);
1946 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1947 * @options: pointer to option string
1948 * @baud: pointer to an 'int' variable for the baud rate.
1949 * @parity: pointer to an 'int' variable for the parity.
1950 * @bits: pointer to an 'int' variable for the number of data bits.
1951 * @flow: pointer to an 'int' variable for the flow control character.
1953 * uart_parse_options decodes a string containing the serial console
1954 * options. The format of the string is <baud><parity><bits><flow>,
1958 uart_parse_options(char *options
, int *baud
, int *parity
, int *bits
, int *flow
)
1962 *baud
= simple_strtoul(s
, NULL
, 10);
1963 while (*s
>= '0' && *s
<= '9')
1972 EXPORT_SYMBOL_GPL(uart_parse_options
);
1975 * uart_set_options - setup the serial console parameters
1976 * @port: pointer to the serial ports uart_port structure
1977 * @co: console pointer
1979 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1980 * @bits: number of data bits
1981 * @flow: flow control character - 'r' (rts)
1984 uart_set_options(struct uart_port
*port
, struct console
*co
,
1985 int baud
, int parity
, int bits
, int flow
)
1987 struct ktermios termios
;
1988 static struct ktermios dummy
;
1991 * Ensure that the serial console lock is initialised
1993 * If this port is a console, then the spinlock is already
1996 if (!(uart_console(port
) && (port
->cons
->flags
& CON_ENABLED
))) {
1997 spin_lock_init(&port
->lock
);
1998 lockdep_set_class(&port
->lock
, &port_lock_key
);
2001 memset(&termios
, 0, sizeof(struct ktermios
));
2003 termios
.c_cflag
|= CREAD
| HUPCL
| CLOCAL
;
2004 tty_termios_encode_baud_rate(&termios
, baud
, baud
);
2007 termios
.c_cflag
|= CS7
;
2009 termios
.c_cflag
|= CS8
;
2013 termios
.c_cflag
|= PARODD
;
2016 termios
.c_cflag
|= PARENB
;
2021 termios
.c_cflag
|= CRTSCTS
;
2024 * some uarts on other side don't support no flow control.
2025 * So we set * DTR in host uart to make them happy
2027 port
->mctrl
|= TIOCM_DTR
;
2029 port
->ops
->set_termios(port
, &termios
, &dummy
);
2031 * Allow the setting of the UART parameters with a NULL console
2035 co
->cflag
= termios
.c_cflag
;
2039 EXPORT_SYMBOL_GPL(uart_set_options
);
2040 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
2043 * uart_change_pm - set power state of the port
2045 * @state: port descriptor
2046 * @pm_state: new state
2048 * Locking: port->mutex has to be held
2050 static void uart_change_pm(struct uart_state
*state
,
2051 enum uart_pm_state pm_state
)
2053 struct uart_port
*port
= uart_port_check(state
);
2055 if (state
->pm_state
!= pm_state
) {
2056 if (port
&& port
->ops
->pm
)
2057 port
->ops
->pm(port
, pm_state
, state
->pm_state
);
2058 state
->pm_state
= pm_state
;
2063 struct uart_port
*port
;
2064 struct uart_driver
*driver
;
2067 static int serial_match_port(struct device
*dev
, void *data
)
2069 struct uart_match
*match
= data
;
2070 struct tty_driver
*tty_drv
= match
->driver
->tty_driver
;
2071 dev_t devt
= MKDEV(tty_drv
->major
, tty_drv
->minor_start
) +
2074 return dev
->devt
== devt
; /* Actually, only one tty per port */
2077 int uart_suspend_port(struct uart_driver
*drv
, struct uart_port
*uport
)
2079 struct uart_state
*state
= drv
->state
+ uport
->line
;
2080 struct tty_port
*port
= &state
->port
;
2081 struct device
*tty_dev
;
2082 struct uart_match match
= {uport
, drv
};
2084 mutex_lock(&port
->mutex
);
2086 tty_dev
= device_find_child(uport
->dev
, &match
, serial_match_port
);
2087 if (tty_dev
&& device_may_wakeup(tty_dev
)) {
2088 enable_irq_wake(uport
->irq
);
2089 put_device(tty_dev
);
2090 mutex_unlock(&port
->mutex
);
2093 put_device(tty_dev
);
2095 /* Nothing to do if the console is not suspending */
2096 if (!console_suspend_enabled
&& uart_console(uport
))
2099 uport
->suspended
= 1;
2101 if (tty_port_initialized(port
)) {
2102 const struct uart_ops
*ops
= uport
->ops
;
2105 tty_port_set_suspended(port
, 1);
2106 tty_port_set_initialized(port
, 0);
2108 spin_lock_irq(&uport
->lock
);
2109 ops
->stop_tx(uport
);
2110 ops
->set_mctrl(uport
, 0);
2111 ops
->stop_rx(uport
);
2112 spin_unlock_irq(&uport
->lock
);
2115 * Wait for the transmitter to empty.
2117 for (tries
= 3; !ops
->tx_empty(uport
) && tries
; tries
--)
2120 dev_err(uport
->dev
, "%s: Unable to drain transmitter\n",
2123 ops
->shutdown(uport
);
2127 * Disable the console device before suspending.
2129 if (uart_console(uport
))
2130 console_stop(uport
->cons
);
2132 uart_change_pm(state
, UART_PM_STATE_OFF
);
2134 mutex_unlock(&port
->mutex
);
2139 int uart_resume_port(struct uart_driver
*drv
, struct uart_port
*uport
)
2141 struct uart_state
*state
= drv
->state
+ uport
->line
;
2142 struct tty_port
*port
= &state
->port
;
2143 struct device
*tty_dev
;
2144 struct uart_match match
= {uport
, drv
};
2145 struct ktermios termios
;
2147 mutex_lock(&port
->mutex
);
2149 tty_dev
= device_find_child(uport
->dev
, &match
, serial_match_port
);
2150 if (!uport
->suspended
&& device_may_wakeup(tty_dev
)) {
2151 if (irqd_is_wakeup_set(irq_get_irq_data((uport
->irq
))))
2152 disable_irq_wake(uport
->irq
);
2153 put_device(tty_dev
);
2154 mutex_unlock(&port
->mutex
);
2157 put_device(tty_dev
);
2158 uport
->suspended
= 0;
2161 * Re-enable the console device after suspending.
2163 if (uart_console(uport
)) {
2165 * First try to use the console cflag setting.
2167 memset(&termios
, 0, sizeof(struct ktermios
));
2168 termios
.c_cflag
= uport
->cons
->cflag
;
2171 * If that's unset, use the tty termios setting.
2173 if (port
->tty
&& termios
.c_cflag
== 0)
2174 termios
= port
->tty
->termios
;
2176 if (console_suspend_enabled
)
2177 uart_change_pm(state
, UART_PM_STATE_ON
);
2178 uport
->ops
->set_termios(uport
, &termios
, NULL
);
2179 if (console_suspend_enabled
)
2180 console_start(uport
->cons
);
2183 if (tty_port_suspended(port
)) {
2184 const struct uart_ops
*ops
= uport
->ops
;
2187 uart_change_pm(state
, UART_PM_STATE_ON
);
2188 spin_lock_irq(&uport
->lock
);
2189 ops
->set_mctrl(uport
, 0);
2190 spin_unlock_irq(&uport
->lock
);
2191 if (console_suspend_enabled
|| !uart_console(uport
)) {
2192 /* Protected by port mutex for now */
2193 struct tty_struct
*tty
= port
->tty
;
2194 ret
= ops
->startup(uport
);
2197 uart_change_speed(tty
, state
, NULL
);
2198 spin_lock_irq(&uport
->lock
);
2199 ops
->set_mctrl(uport
, uport
->mctrl
);
2200 ops
->start_tx(uport
);
2201 spin_unlock_irq(&uport
->lock
);
2202 tty_port_set_initialized(port
, 1);
2205 * Failed to resume - maybe hardware went away?
2206 * Clear the "initialized" flag so we won't try
2207 * to call the low level drivers shutdown method.
2209 uart_shutdown(tty
, state
);
2213 tty_port_set_suspended(port
, 0);
2216 mutex_unlock(&port
->mutex
);
2222 uart_report_port(struct uart_driver
*drv
, struct uart_port
*port
)
2226 switch (port
->iotype
) {
2228 snprintf(address
, sizeof(address
), "I/O 0x%lx", port
->iobase
);
2231 snprintf(address
, sizeof(address
),
2232 "I/O 0x%lx offset 0x%x", port
->iobase
, port
->hub6
);
2240 snprintf(address
, sizeof(address
),
2241 "MMIO 0x%llx", (unsigned long long)port
->mapbase
);
2244 strlcpy(address
, "*unknown*", sizeof(address
));
2248 pr_info("%s%s%s at %s (irq = %d, base_baud = %d) is a %s\n",
2249 port
->dev
? dev_name(port
->dev
) : "",
2250 port
->dev
? ": " : "",
2252 address
, port
->irq
, port
->uartclk
/ 16, uart_type(port
));
2256 uart_configure_port(struct uart_driver
*drv
, struct uart_state
*state
,
2257 struct uart_port
*port
)
2262 * If there isn't a port here, don't do anything further.
2264 if (!port
->iobase
&& !port
->mapbase
&& !port
->membase
)
2268 * Now do the auto configuration stuff. Note that config_port
2269 * is expected to claim the resources and map the port for us.
2272 if (port
->flags
& UPF_AUTO_IRQ
)
2273 flags
|= UART_CONFIG_IRQ
;
2274 if (port
->flags
& UPF_BOOT_AUTOCONF
) {
2275 if (!(port
->flags
& UPF_FIXED_TYPE
)) {
2276 port
->type
= PORT_UNKNOWN
;
2277 flags
|= UART_CONFIG_TYPE
;
2279 port
->ops
->config_port(port
, flags
);
2282 if (port
->type
!= PORT_UNKNOWN
) {
2283 unsigned long flags
;
2285 uart_report_port(drv
, port
);
2287 /* Power up port for set_mctrl() */
2288 uart_change_pm(state
, UART_PM_STATE_ON
);
2291 * Ensure that the modem control lines are de-activated.
2292 * keep the DTR setting that is set in uart_set_options()
2293 * We probably don't need a spinlock around this, but
2295 spin_lock_irqsave(&port
->lock
, flags
);
2296 port
->ops
->set_mctrl(port
, port
->mctrl
& TIOCM_DTR
);
2297 spin_unlock_irqrestore(&port
->lock
, flags
);
2300 * If this driver supports console, and it hasn't been
2301 * successfully registered yet, try to re-register it.
2302 * It may be that the port was not available.
2304 if (port
->cons
&& !(port
->cons
->flags
& CON_ENABLED
))
2305 register_console(port
->cons
);
2308 * Power down all ports by default, except the
2309 * console if we have one.
2311 if (!uart_console(port
))
2312 uart_change_pm(state
, UART_PM_STATE_OFF
);
2316 #ifdef CONFIG_CONSOLE_POLL
2318 static int uart_poll_init(struct tty_driver
*driver
, int line
, char *options
)
2320 struct uart_driver
*drv
= driver
->driver_state
;
2321 struct uart_state
*state
= drv
->state
+ line
;
2322 struct tty_port
*tport
;
2323 struct uart_port
*port
;
2330 tport
= &state
->port
;
2331 mutex_lock(&tport
->mutex
);
2333 port
= uart_port_check(state
);
2334 if (!port
|| !(port
->ops
->poll_get_char
&& port
->ops
->poll_put_char
)) {
2339 if (port
->ops
->poll_init
) {
2341 * We don't set initialized as we only initialized the hw,
2342 * e.g. state->xmit is still uninitialized.
2344 if (!tty_port_initialized(tport
))
2345 ret
= port
->ops
->poll_init(port
);
2348 if (!ret
&& options
) {
2349 uart_parse_options(options
, &baud
, &parity
, &bits
, &flow
);
2350 ret
= uart_set_options(port
, NULL
, baud
, parity
, bits
, flow
);
2353 mutex_unlock(&tport
->mutex
);
2357 static int uart_poll_get_char(struct tty_driver
*driver
, int line
)
2359 struct uart_driver
*drv
= driver
->driver_state
;
2360 struct uart_state
*state
= drv
->state
+ line
;
2361 struct uart_port
*port
;
2364 port
= uart_port_ref(state
);
2366 ret
= port
->ops
->poll_get_char(port
);
2367 uart_port_deref(port
);
2373 static void uart_poll_put_char(struct tty_driver
*driver
, int line
, char ch
)
2375 struct uart_driver
*drv
= driver
->driver_state
;
2376 struct uart_state
*state
= drv
->state
+ line
;
2377 struct uart_port
*port
;
2379 port
= uart_port_ref(state
);
2384 port
->ops
->poll_put_char(port
, '\r');
2385 port
->ops
->poll_put_char(port
, ch
);
2386 uart_port_deref(port
);
2390 static const struct tty_operations uart_ops
= {
2392 .close
= uart_close
,
2393 .write
= uart_write
,
2394 .put_char
= uart_put_char
,
2395 .flush_chars
= uart_flush_chars
,
2396 .write_room
= uart_write_room
,
2397 .chars_in_buffer
= uart_chars_in_buffer
,
2398 .flush_buffer
= uart_flush_buffer
,
2399 .ioctl
= uart_ioctl
,
2400 .throttle
= uart_throttle
,
2401 .unthrottle
= uart_unthrottle
,
2402 .send_xchar
= uart_send_xchar
,
2403 .set_termios
= uart_set_termios
,
2404 .set_ldisc
= uart_set_ldisc
,
2406 .start
= uart_start
,
2407 .hangup
= uart_hangup
,
2408 .break_ctl
= uart_break_ctl
,
2409 .wait_until_sent
= uart_wait_until_sent
,
2410 #ifdef CONFIG_PROC_FS
2411 .proc_fops
= &uart_proc_fops
,
2413 .tiocmget
= uart_tiocmget
,
2414 .tiocmset
= uart_tiocmset
,
2415 .get_icount
= uart_get_icount
,
2416 #ifdef CONFIG_CONSOLE_POLL
2417 .poll_init
= uart_poll_init
,
2418 .poll_get_char
= uart_poll_get_char
,
2419 .poll_put_char
= uart_poll_put_char
,
2423 static const struct tty_port_operations uart_port_ops
= {
2424 .carrier_raised
= uart_carrier_raised
,
2425 .dtr_rts
= uart_dtr_rts
,
2426 .activate
= uart_port_activate
,
2427 .shutdown
= uart_tty_port_shutdown
,
2431 * uart_register_driver - register a driver with the uart core layer
2432 * @drv: low level driver structure
2434 * Register a uart driver with the core driver. We in turn register
2435 * with the tty layer, and initialise the core driver per-port state.
2437 * We have a proc file in /proc/tty/driver which is named after the
2440 * drv->port should be NULL, and the per-port structures should be
2441 * registered using uart_add_one_port after this call has succeeded.
2443 int uart_register_driver(struct uart_driver
*drv
)
2445 struct tty_driver
*normal
;
2451 * Maybe we should be using a slab cache for this, especially if
2452 * we have a large number of ports to handle.
2454 drv
->state
= kzalloc(sizeof(struct uart_state
) * drv
->nr
, GFP_KERNEL
);
2458 normal
= alloc_tty_driver(drv
->nr
);
2462 drv
->tty_driver
= normal
;
2464 normal
->driver_name
= drv
->driver_name
;
2465 normal
->name
= drv
->dev_name
;
2466 normal
->major
= drv
->major
;
2467 normal
->minor_start
= drv
->minor
;
2468 normal
->type
= TTY_DRIVER_TYPE_SERIAL
;
2469 normal
->subtype
= SERIAL_TYPE_NORMAL
;
2470 normal
->init_termios
= tty_std_termios
;
2471 normal
->init_termios
.c_cflag
= B9600
| CS8
| CREAD
| HUPCL
| CLOCAL
;
2472 normal
->init_termios
.c_ispeed
= normal
->init_termios
.c_ospeed
= 9600;
2473 normal
->flags
= TTY_DRIVER_REAL_RAW
| TTY_DRIVER_DYNAMIC_DEV
;
2474 normal
->driver_state
= drv
;
2475 tty_set_operations(normal
, &uart_ops
);
2478 * Initialise the UART state(s).
2480 for (i
= 0; i
< drv
->nr
; i
++) {
2481 struct uart_state
*state
= drv
->state
+ i
;
2482 struct tty_port
*port
= &state
->port
;
2484 tty_port_init(port
);
2485 port
->ops
= &uart_port_ops
;
2488 retval
= tty_register_driver(normal
);
2492 for (i
= 0; i
< drv
->nr
; i
++)
2493 tty_port_destroy(&drv
->state
[i
].port
);
2494 put_tty_driver(normal
);
2502 * uart_unregister_driver - remove a driver from the uart core layer
2503 * @drv: low level driver structure
2505 * Remove all references to a driver from the core driver. The low
2506 * level driver must have removed all its ports via the
2507 * uart_remove_one_port() if it registered them with uart_add_one_port().
2508 * (ie, drv->port == NULL)
2510 void uart_unregister_driver(struct uart_driver
*drv
)
2512 struct tty_driver
*p
= drv
->tty_driver
;
2515 tty_unregister_driver(p
);
2517 for (i
= 0; i
< drv
->nr
; i
++)
2518 tty_port_destroy(&drv
->state
[i
].port
);
2521 drv
->tty_driver
= NULL
;
2524 struct tty_driver
*uart_console_device(struct console
*co
, int *index
)
2526 struct uart_driver
*p
= co
->data
;
2528 return p
->tty_driver
;
2531 static ssize_t
uart_get_attr_uartclk(struct device
*dev
,
2532 struct device_attribute
*attr
, char *buf
)
2534 struct serial_struct tmp
;
2535 struct tty_port
*port
= dev_get_drvdata(dev
);
2537 uart_get_info(port
, &tmp
);
2538 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.baud_base
* 16);
2541 static ssize_t
uart_get_attr_type(struct device
*dev
,
2542 struct device_attribute
*attr
, char *buf
)
2544 struct serial_struct tmp
;
2545 struct tty_port
*port
= dev_get_drvdata(dev
);
2547 uart_get_info(port
, &tmp
);
2548 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.type
);
2550 static ssize_t
uart_get_attr_line(struct device
*dev
,
2551 struct device_attribute
*attr
, char *buf
)
2553 struct serial_struct tmp
;
2554 struct tty_port
*port
= dev_get_drvdata(dev
);
2556 uart_get_info(port
, &tmp
);
2557 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.line
);
2560 static ssize_t
uart_get_attr_port(struct device
*dev
,
2561 struct device_attribute
*attr
, char *buf
)
2563 struct serial_struct tmp
;
2564 struct tty_port
*port
= dev_get_drvdata(dev
);
2565 unsigned long ioaddr
;
2567 uart_get_info(port
, &tmp
);
2569 if (HIGH_BITS_OFFSET
)
2570 ioaddr
|= (unsigned long)tmp
.port_high
<< HIGH_BITS_OFFSET
;
2571 return snprintf(buf
, PAGE_SIZE
, "0x%lX\n", ioaddr
);
2574 static ssize_t
uart_get_attr_irq(struct device
*dev
,
2575 struct device_attribute
*attr
, char *buf
)
2577 struct serial_struct tmp
;
2578 struct tty_port
*port
= dev_get_drvdata(dev
);
2580 uart_get_info(port
, &tmp
);
2581 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.irq
);
2584 static ssize_t
uart_get_attr_flags(struct device
*dev
,
2585 struct device_attribute
*attr
, char *buf
)
2587 struct serial_struct tmp
;
2588 struct tty_port
*port
= dev_get_drvdata(dev
);
2590 uart_get_info(port
, &tmp
);
2591 return snprintf(buf
, PAGE_SIZE
, "0x%X\n", tmp
.flags
);
2594 static ssize_t
uart_get_attr_xmit_fifo_size(struct device
*dev
,
2595 struct device_attribute
*attr
, char *buf
)
2597 struct serial_struct tmp
;
2598 struct tty_port
*port
= dev_get_drvdata(dev
);
2600 uart_get_info(port
, &tmp
);
2601 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.xmit_fifo_size
);
2605 static ssize_t
uart_get_attr_close_delay(struct device
*dev
,
2606 struct device_attribute
*attr
, char *buf
)
2608 struct serial_struct tmp
;
2609 struct tty_port
*port
= dev_get_drvdata(dev
);
2611 uart_get_info(port
, &tmp
);
2612 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.close_delay
);
2616 static ssize_t
uart_get_attr_closing_wait(struct device
*dev
,
2617 struct device_attribute
*attr
, char *buf
)
2619 struct serial_struct tmp
;
2620 struct tty_port
*port
= dev_get_drvdata(dev
);
2622 uart_get_info(port
, &tmp
);
2623 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.closing_wait
);
2626 static ssize_t
uart_get_attr_custom_divisor(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
.custom_divisor
);
2636 static ssize_t
uart_get_attr_io_type(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
, "%d\n", tmp
.io_type
);
2646 static ssize_t
uart_get_attr_iomem_base(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
, "0x%lX\n", (unsigned long)tmp
.iomem_base
);
2656 static ssize_t
uart_get_attr_iomem_reg_shift(struct device
*dev
,
2657 struct device_attribute
*attr
, char *buf
)
2659 struct serial_struct tmp
;
2660 struct tty_port
*port
= dev_get_drvdata(dev
);
2662 uart_get_info(port
, &tmp
);
2663 return snprintf(buf
, PAGE_SIZE
, "%d\n", tmp
.iomem_reg_shift
);
2666 static DEVICE_ATTR(type
, S_IRUSR
| S_IRGRP
, uart_get_attr_type
, NULL
);
2667 static DEVICE_ATTR(line
, S_IRUSR
| S_IRGRP
, uart_get_attr_line
, NULL
);
2668 static DEVICE_ATTR(port
, S_IRUSR
| S_IRGRP
, uart_get_attr_port
, NULL
);
2669 static DEVICE_ATTR(irq
, S_IRUSR
| S_IRGRP
, uart_get_attr_irq
, NULL
);
2670 static DEVICE_ATTR(flags
, S_IRUSR
| S_IRGRP
, uart_get_attr_flags
, NULL
);
2671 static DEVICE_ATTR(xmit_fifo_size
, S_IRUSR
| S_IRGRP
, uart_get_attr_xmit_fifo_size
, NULL
);
2672 static DEVICE_ATTR(uartclk
, S_IRUSR
| S_IRGRP
, uart_get_attr_uartclk
, NULL
);
2673 static DEVICE_ATTR(close_delay
, S_IRUSR
| S_IRGRP
, uart_get_attr_close_delay
, NULL
);
2674 static DEVICE_ATTR(closing_wait
, S_IRUSR
| S_IRGRP
, uart_get_attr_closing_wait
, NULL
);
2675 static DEVICE_ATTR(custom_divisor
, S_IRUSR
| S_IRGRP
, uart_get_attr_custom_divisor
, NULL
);
2676 static DEVICE_ATTR(io_type
, S_IRUSR
| S_IRGRP
, uart_get_attr_io_type
, NULL
);
2677 static DEVICE_ATTR(iomem_base
, S_IRUSR
| S_IRGRP
, uart_get_attr_iomem_base
, NULL
);
2678 static DEVICE_ATTR(iomem_reg_shift
, S_IRUSR
| S_IRGRP
, uart_get_attr_iomem_reg_shift
, NULL
);
2680 static struct attribute
*tty_dev_attrs
[] = {
2681 &dev_attr_type
.attr
,
2682 &dev_attr_line
.attr
,
2683 &dev_attr_port
.attr
,
2685 &dev_attr_flags
.attr
,
2686 &dev_attr_xmit_fifo_size
.attr
,
2687 &dev_attr_uartclk
.attr
,
2688 &dev_attr_close_delay
.attr
,
2689 &dev_attr_closing_wait
.attr
,
2690 &dev_attr_custom_divisor
.attr
,
2691 &dev_attr_io_type
.attr
,
2692 &dev_attr_iomem_base
.attr
,
2693 &dev_attr_iomem_reg_shift
.attr
,
2697 static const struct attribute_group tty_dev_attr_group
= {
2698 .attrs
= tty_dev_attrs
,
2702 * uart_add_one_port - attach a driver-defined port structure
2703 * @drv: pointer to the uart low level driver structure for this port
2704 * @uport: uart port structure to use for this port.
2706 * This allows the driver to register its own uart_port structure
2707 * with the core driver. The main purpose is to allow the low
2708 * level uart drivers to expand uart_port, rather than having yet
2709 * more levels of structures.
2711 int uart_add_one_port(struct uart_driver
*drv
, struct uart_port
*uport
)
2713 struct uart_state
*state
;
2714 struct tty_port
*port
;
2716 struct device
*tty_dev
;
2719 BUG_ON(in_interrupt());
2721 if (uport
->line
>= drv
->nr
)
2724 state
= drv
->state
+ uport
->line
;
2725 port
= &state
->port
;
2727 mutex_lock(&port_mutex
);
2728 mutex_lock(&port
->mutex
);
2729 if (state
->uart_port
) {
2734 /* Link the port to the driver state table and vice versa */
2735 atomic_set(&state
->refcount
, 1);
2736 init_waitqueue_head(&state
->remove_wait
);
2737 state
->uart_port
= uport
;
2738 uport
->state
= state
;
2740 state
->pm_state
= UART_PM_STATE_UNDEFINED
;
2741 uport
->cons
= drv
->cons
;
2742 uport
->minor
= drv
->tty_driver
->minor_start
+ uport
->line
;
2743 uport
->name
= kasprintf(GFP_KERNEL
, "%s%d", drv
->dev_name
,
2744 drv
->tty_driver
->name_base
+ uport
->line
);
2751 * If this port is a console, then the spinlock is already
2754 if (!(uart_console(uport
) && (uport
->cons
->flags
& CON_ENABLED
))) {
2755 spin_lock_init(&uport
->lock
);
2756 lockdep_set_class(&uport
->lock
, &port_lock_key
);
2758 if (uport
->cons
&& uport
->dev
)
2759 of_console_check(uport
->dev
->of_node
, uport
->cons
->name
, uport
->line
);
2761 uart_configure_port(drv
, state
, uport
);
2763 port
->console
= uart_console(uport
);
2766 if (uport
->attr_group
)
2769 uport
->tty_groups
= kcalloc(num_groups
, sizeof(*uport
->tty_groups
),
2771 if (!uport
->tty_groups
) {
2775 uport
->tty_groups
[0] = &tty_dev_attr_group
;
2776 if (uport
->attr_group
)
2777 uport
->tty_groups
[1] = uport
->attr_group
;
2780 * Register the port whether it's detected or not. This allows
2781 * setserial to be used to alter this port's parameters.
2783 tty_dev
= tty_port_register_device_attr_serdev(port
, drv
->tty_driver
,
2784 uport
->line
, uport
->dev
, port
, uport
->tty_groups
);
2785 if (likely(!IS_ERR(tty_dev
))) {
2786 device_set_wakeup_capable(tty_dev
, 1);
2788 dev_err(uport
->dev
, "Cannot register tty device on line %d\n",
2793 * Ensure UPF_DEAD is not set.
2795 uport
->flags
&= ~UPF_DEAD
;
2798 mutex_unlock(&port
->mutex
);
2799 mutex_unlock(&port_mutex
);
2805 * uart_remove_one_port - detach a driver defined port structure
2806 * @drv: pointer to the uart low level driver structure for this port
2807 * @uport: uart port structure for this port
2809 * This unhooks (and hangs up) the specified port structure from the
2810 * core driver. No further calls will be made to the low-level code
2813 int uart_remove_one_port(struct uart_driver
*drv
, struct uart_port
*uport
)
2815 struct uart_state
*state
= drv
->state
+ uport
->line
;
2816 struct tty_port
*port
= &state
->port
;
2817 struct uart_port
*uart_port
;
2818 struct tty_struct
*tty
;
2821 BUG_ON(in_interrupt());
2823 mutex_lock(&port_mutex
);
2826 * Mark the port "dead" - this prevents any opens from
2827 * succeeding while we shut down the port.
2829 mutex_lock(&port
->mutex
);
2830 uart_port
= uart_port_check(state
);
2831 if (uart_port
!= uport
)
2832 dev_alert(uport
->dev
, "Removing wrong port: %p != %p\n",
2836 mutex_unlock(&port
->mutex
);
2840 uport
->flags
|= UPF_DEAD
;
2841 mutex_unlock(&port
->mutex
);
2844 * Remove the devices from the tty layer
2846 tty_port_unregister_device(port
, drv
->tty_driver
, uport
->line
);
2848 tty
= tty_port_tty_get(port
);
2850 tty_vhangup(port
->tty
);
2855 * If the port is used as a console, unregister it
2857 if (uart_console(uport
))
2858 unregister_console(uport
->cons
);
2861 * Free the port IO and memory resources, if any.
2863 if (uport
->type
!= PORT_UNKNOWN
&& uport
->ops
->release_port
)
2864 uport
->ops
->release_port(uport
);
2865 kfree(uport
->tty_groups
);
2869 * Indicate that there isn't a port here anymore.
2871 uport
->type
= PORT_UNKNOWN
;
2873 mutex_lock(&port
->mutex
);
2874 WARN_ON(atomic_dec_return(&state
->refcount
) < 0);
2875 wait_event(state
->remove_wait
, !atomic_read(&state
->refcount
));
2876 state
->uart_port
= NULL
;
2877 mutex_unlock(&port
->mutex
);
2879 mutex_unlock(&port_mutex
);
2885 * Are the two ports equivalent?
2887 int uart_match_port(struct uart_port
*port1
, struct uart_port
*port2
)
2889 if (port1
->iotype
!= port2
->iotype
)
2892 switch (port1
->iotype
) {
2894 return (port1
->iobase
== port2
->iobase
);
2896 return (port1
->iobase
== port2
->iobase
) &&
2897 (port1
->hub6
== port2
->hub6
);
2904 return (port1
->mapbase
== port2
->mapbase
);
2908 EXPORT_SYMBOL(uart_match_port
);
2911 * uart_handle_dcd_change - handle a change of carrier detect state
2912 * @uport: uart_port structure for the open port
2913 * @status: new carrier detect status, nonzero if active
2915 * Caller must hold uport->lock
2917 void uart_handle_dcd_change(struct uart_port
*uport
, unsigned int status
)
2919 struct tty_port
*port
= &uport
->state
->port
;
2920 struct tty_struct
*tty
= port
->tty
;
2921 struct tty_ldisc
*ld
;
2923 lockdep_assert_held_once(&uport
->lock
);
2926 ld
= tty_ldisc_ref(tty
);
2928 if (ld
->ops
->dcd_change
)
2929 ld
->ops
->dcd_change(tty
, status
);
2930 tty_ldisc_deref(ld
);
2934 uport
->icount
.dcd
++;
2936 if (uart_dcd_enabled(uport
)) {
2938 wake_up_interruptible(&port
->open_wait
);
2943 EXPORT_SYMBOL_GPL(uart_handle_dcd_change
);
2946 * uart_handle_cts_change - handle a change of clear-to-send state
2947 * @uport: uart_port structure for the open port
2948 * @status: new clear to send status, nonzero if active
2950 * Caller must hold uport->lock
2952 void uart_handle_cts_change(struct uart_port
*uport
, unsigned int status
)
2954 lockdep_assert_held_once(&uport
->lock
);
2956 uport
->icount
.cts
++;
2958 if (uart_softcts_mode(uport
)) {
2959 if (uport
->hw_stopped
) {
2961 uport
->hw_stopped
= 0;
2962 uport
->ops
->start_tx(uport
);
2963 uart_write_wakeup(uport
);
2967 uport
->hw_stopped
= 1;
2968 uport
->ops
->stop_tx(uport
);
2974 EXPORT_SYMBOL_GPL(uart_handle_cts_change
);
2977 * uart_insert_char - push a char to the uart layer
2979 * User is responsible to call tty_flip_buffer_push when they are done with
2982 * @port: corresponding port
2983 * @status: state of the serial port RX buffer (LSR for 8250)
2984 * @overrun: mask of overrun bits in @status
2985 * @ch: character to push
2986 * @flag: flag for the character (see TTY_NORMAL and friends)
2988 void uart_insert_char(struct uart_port
*port
, unsigned int status
,
2989 unsigned int overrun
, unsigned int ch
, unsigned int flag
)
2991 struct tty_port
*tport
= &port
->state
->port
;
2993 if ((status
& port
->ignore_status_mask
& ~overrun
) == 0)
2994 if (tty_insert_flip_char(tport
, ch
, flag
) == 0)
2995 ++port
->icount
.buf_overrun
;
2998 * Overrun is special. Since it's reported immediately,
2999 * it doesn't affect the current character.
3001 if (status
& ~port
->ignore_status_mask
& overrun
)
3002 if (tty_insert_flip_char(tport
, 0, TTY_OVERRUN
) == 0)
3003 ++port
->icount
.buf_overrun
;
3005 EXPORT_SYMBOL_GPL(uart_insert_char
);
3007 EXPORT_SYMBOL(uart_write_wakeup
);
3008 EXPORT_SYMBOL(uart_register_driver
);
3009 EXPORT_SYMBOL(uart_unregister_driver
);
3010 EXPORT_SYMBOL(uart_suspend_port
);
3011 EXPORT_SYMBOL(uart_resume_port
);
3012 EXPORT_SYMBOL(uart_add_one_port
);
3013 EXPORT_SYMBOL(uart_remove_one_port
);
3016 * of_get_rs485_mode() - Implement parsing rs485 properties
3018 * @rs485conf: output parameter
3020 * This function implements the device tree binding described in
3021 * Documentation/devicetree/bindings/serial/rs485.txt.
3023 void of_get_rs485_mode(struct device_node
*np
, struct serial_rs485
*rs485conf
)
3028 ret
= of_property_read_u32_array(np
, "rs485-rts-delay", rs485_delay
, 2);
3030 rs485conf
->delay_rts_before_send
= rs485_delay
[0];
3031 rs485conf
->delay_rts_after_send
= rs485_delay
[1];
3033 rs485conf
->delay_rts_before_send
= 0;
3034 rs485conf
->delay_rts_after_send
= 0;
3038 * clear full-duplex and enabled flags to get to a defined state with
3039 * the two following properties.
3041 rs485conf
->flags
&= ~(SER_RS485_RX_DURING_TX
| SER_RS485_ENABLED
);
3043 if (of_property_read_bool(np
, "rs485-rx-during-tx"))
3044 rs485conf
->flags
|= SER_RS485_RX_DURING_TX
;
3046 if (of_property_read_bool(np
, "linux,rs485-enabled-at-boot-time"))
3047 rs485conf
->flags
|= SER_RS485_ENABLED
;
3049 EXPORT_SYMBOL_GPL(of_get_rs485_mode
);
3051 MODULE_DESCRIPTION("Serial driver core");
3052 MODULE_LICENSE("GPL");