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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Driver core for serial ports
4 *
5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 *
7 * Copyright 1999 ARM Limited
8 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
9 */
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>
17#include <linux/gpio/consumer.h>
18#include <linux/of.h>
19#include <linux/proc_fs.h>
20#include <linux/seq_file.h>
21#include <linux/device.h>
22#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
23#include <linux/serial_core.h>
24#include <linux/sysrq.h>
25#include <linux/delay.h>
26#include <linux/mutex.h>
27#include <linux/math64.h>
28#include <linux/security.h>
29
30#include <linux/irq.h>
31#include <linux/uaccess.h>
32
33/*
34 * This is used to lock changes in serial line configuration.
35 */
36static DEFINE_MUTEX(port_mutex);
37
38/*
39 * lockdep: port->lock is initialized in two places, but we
40 * want only one lock-class:
41 */
42static struct lock_class_key port_lock_key;
43
44#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
45
46/*
47 * Max time with active RTS before/after data is sent.
48 */
49#define RS485_MAX_RTS_DELAY 100 /* msecs */
50
51static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
52 const struct ktermios *old_termios);
53static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
54static void uart_change_pm(struct uart_state *state,
55 enum uart_pm_state pm_state);
56
57static void uart_port_shutdown(struct tty_port *port);
58
59static int uart_dcd_enabled(struct uart_port *uport)
60{
61 return !!(uport->status & UPSTAT_DCD_ENABLE);
62}
63
64static inline struct uart_port *uart_port_ref(struct uart_state *state)
65{
66 if (atomic_add_unless(&state->refcount, 1, 0))
67 return state->uart_port;
68 return NULL;
69}
70
71static inline void uart_port_deref(struct uart_port *uport)
72{
73 if (atomic_dec_and_test(&uport->state->refcount))
74 wake_up(&uport->state->remove_wait);
75}
76
77#define uart_port_lock(state, flags) \
78 ({ \
79 struct uart_port *__uport = uart_port_ref(state); \
80 if (__uport) \
81 spin_lock_irqsave(&__uport->lock, flags); \
82 __uport; \
83 })
84
85#define uart_port_unlock(uport, flags) \
86 ({ \
87 struct uart_port *__uport = uport; \
88 if (__uport) { \
89 spin_unlock_irqrestore(&__uport->lock, flags); \
90 uart_port_deref(__uport); \
91 } \
92 })
93
94static inline struct uart_port *uart_port_check(struct uart_state *state)
95{
96 lockdep_assert_held(&state->port.mutex);
97 return state->uart_port;
98}
99
100/**
101 * uart_write_wakeup - schedule write processing
102 * @port: port to be processed
103 *
104 * This routine is used by the interrupt handler to schedule processing in the
105 * software interrupt portion of the driver. A driver is expected to call this
106 * function when the number of characters in the transmit buffer have dropped
107 * below a threshold.
108 *
109 * Locking: @port->lock should be held
110 */
111void uart_write_wakeup(struct uart_port *port)
112{
113 struct uart_state *state = port->state;
114 /*
115 * This means you called this function _after_ the port was
116 * closed. No cookie for you.
117 */
118 BUG_ON(!state);
119 tty_port_tty_wakeup(&state->port);
120}
121EXPORT_SYMBOL(uart_write_wakeup);
122
123static void uart_stop(struct tty_struct *tty)
124{
125 struct uart_state *state = tty->driver_data;
126 struct uart_port *port;
127 unsigned long flags;
128
129 port = uart_port_lock(state, flags);
130 if (port)
131 port->ops->stop_tx(port);
132 uart_port_unlock(port, flags);
133}
134
135static void __uart_start(struct tty_struct *tty)
136{
137 struct uart_state *state = tty->driver_data;
138 struct uart_port *port = state->uart_port;
139
140 if (port && !uart_tx_stopped(port))
141 port->ops->start_tx(port);
142}
143
144static void uart_start(struct tty_struct *tty)
145{
146 struct uart_state *state = tty->driver_data;
147 struct uart_port *port;
148 unsigned long flags;
149
150 port = uart_port_lock(state, flags);
151 __uart_start(tty);
152 uart_port_unlock(port, flags);
153}
154
155static void
156uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
157{
158 unsigned long flags;
159 unsigned int old;
160
161 spin_lock_irqsave(&port->lock, flags);
162 old = port->mctrl;
163 port->mctrl = (old & ~clear) | set;
164 if (old != port->mctrl && !(port->rs485.flags & SER_RS485_ENABLED))
165 port->ops->set_mctrl(port, port->mctrl);
166 spin_unlock_irqrestore(&port->lock, flags);
167}
168
169#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
170#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
171
172static void uart_port_dtr_rts(struct uart_port *uport, int raise)
173{
174 if (raise)
175 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
176 else
177 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
178}
179
180/*
181 * Startup the port. This will be called once per open. All calls
182 * will be serialised by the per-port mutex.
183 */
184static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
185 int init_hw)
186{
187 struct uart_port *uport = uart_port_check(state);
188 unsigned long flags;
189 unsigned long page;
190 int retval = 0;
191
192 if (uport->type == PORT_UNKNOWN)
193 return 1;
194
195 /*
196 * Make sure the device is in D0 state.
197 */
198 uart_change_pm(state, UART_PM_STATE_ON);
199
200 /*
201 * Initialise and allocate the transmit and temporary
202 * buffer.
203 */
204 page = get_zeroed_page(GFP_KERNEL);
205 if (!page)
206 return -ENOMEM;
207
208 uart_port_lock(state, flags);
209 if (!state->xmit.buf) {
210 state->xmit.buf = (unsigned char *) page;
211 uart_circ_clear(&state->xmit);
212 uart_port_unlock(uport, flags);
213 } else {
214 uart_port_unlock(uport, flags);
215 /*
216 * Do not free() the page under the port lock, see
217 * uart_shutdown().
218 */
219 free_page(page);
220 }
221
222 retval = uport->ops->startup(uport);
223 if (retval == 0) {
224 if (uart_console(uport) && uport->cons->cflag) {
225 tty->termios.c_cflag = uport->cons->cflag;
226 tty->termios.c_ispeed = uport->cons->ispeed;
227 tty->termios.c_ospeed = uport->cons->ospeed;
228 uport->cons->cflag = 0;
229 uport->cons->ispeed = 0;
230 uport->cons->ospeed = 0;
231 }
232 /*
233 * Initialise the hardware port settings.
234 */
235 uart_change_speed(tty, state, NULL);
236
237 /*
238 * Setup the RTS and DTR signals once the
239 * port is open and ready to respond.
240 */
241 if (init_hw && C_BAUD(tty))
242 uart_port_dtr_rts(uport, 1);
243 }
244
245 /*
246 * This is to allow setserial on this port. People may want to set
247 * port/irq/type and then reconfigure the port properly if it failed
248 * now.
249 */
250 if (retval && capable(CAP_SYS_ADMIN))
251 return 1;
252
253 return retval;
254}
255
256static int uart_startup(struct tty_struct *tty, struct uart_state *state,
257 int init_hw)
258{
259 struct tty_port *port = &state->port;
260 int retval;
261
262 if (tty_port_initialized(port))
263 return 0;
264
265 retval = uart_port_startup(tty, state, init_hw);
266 if (retval)
267 set_bit(TTY_IO_ERROR, &tty->flags);
268
269 return retval;
270}
271
272/*
273 * This routine will shutdown a serial port; interrupts are disabled, and
274 * DTR is dropped if the hangup on close termio flag is on. Calls to
275 * uart_shutdown are serialised by the per-port semaphore.
276 *
277 * uport == NULL if uart_port has already been removed
278 */
279static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
280{
281 struct uart_port *uport = uart_port_check(state);
282 struct tty_port *port = &state->port;
283 unsigned long flags;
284 char *xmit_buf = NULL;
285
286 /*
287 * Set the TTY IO error marker
288 */
289 if (tty)
290 set_bit(TTY_IO_ERROR, &tty->flags);
291
292 if (tty_port_initialized(port)) {
293 tty_port_set_initialized(port, 0);
294
295 /*
296 * Turn off DTR and RTS early.
297 */
298 if (uport && uart_console(uport) && tty) {
299 uport->cons->cflag = tty->termios.c_cflag;
300 uport->cons->ispeed = tty->termios.c_ispeed;
301 uport->cons->ospeed = tty->termios.c_ospeed;
302 }
303
304 if (!tty || C_HUPCL(tty))
305 uart_port_dtr_rts(uport, 0);
306
307 uart_port_shutdown(port);
308 }
309
310 /*
311 * It's possible for shutdown to be called after suspend if we get
312 * a DCD drop (hangup) at just the right time. Clear suspended bit so
313 * we don't try to resume a port that has been shutdown.
314 */
315 tty_port_set_suspended(port, 0);
316
317 /*
318 * Do not free() the transmit buffer page under the port lock since
319 * this can create various circular locking scenarios. For instance,
320 * console driver may need to allocate/free a debug object, which
321 * can endup in printk() recursion.
322 */
323 uart_port_lock(state, flags);
324 xmit_buf = state->xmit.buf;
325 state->xmit.buf = NULL;
326 uart_port_unlock(uport, flags);
327
328 free_page((unsigned long)xmit_buf);
329}
330
331/**
332 * uart_update_timeout - update per-port frame timing information
333 * @port: uart_port structure describing the port
334 * @cflag: termios cflag value
335 * @baud: speed of the port
336 *
337 * Set the @port frame timing information from which the FIFO timeout value is
338 * derived. The @cflag value should reflect the actual hardware settings as
339 * number of bits, parity, stop bits and baud rate is taken into account here.
340 *
341 * Locking: caller is expected to take @port->lock
342 */
343void
344uart_update_timeout(struct uart_port *port, unsigned int cflag,
345 unsigned int baud)
346{
347 unsigned int size = tty_get_frame_size(cflag);
348 u64 frame_time;
349
350 frame_time = (u64)size * NSEC_PER_SEC;
351 port->frame_time = DIV64_U64_ROUND_UP(frame_time, baud);
352}
353EXPORT_SYMBOL(uart_update_timeout);
354
355/**
356 * uart_get_baud_rate - return baud rate for a particular port
357 * @port: uart_port structure describing the port in question.
358 * @termios: desired termios settings
359 * @old: old termios (or %NULL)
360 * @min: minimum acceptable baud rate
361 * @max: maximum acceptable baud rate
362 *
363 * Decode the termios structure into a numeric baud rate, taking account of the
364 * magic 38400 baud rate (with spd_* flags), and mapping the %B0 rate to 9600
365 * baud.
366 *
367 * If the new baud rate is invalid, try the @old termios setting. If it's still
368 * invalid, we try 9600 baud.
369 *
370 * The @termios structure is updated to reflect the baud rate we're actually
371 * going to be using. Don't do this for the case where B0 is requested ("hang
372 * up").
373 *
374 * Locking: caller dependent
375 */
376unsigned int
377uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
378 const struct ktermios *old, unsigned int min, unsigned int max)
379{
380 unsigned int try;
381 unsigned int baud;
382 unsigned int altbaud;
383 int hung_up = 0;
384 upf_t flags = port->flags & UPF_SPD_MASK;
385
386 switch (flags) {
387 case UPF_SPD_HI:
388 altbaud = 57600;
389 break;
390 case UPF_SPD_VHI:
391 altbaud = 115200;
392 break;
393 case UPF_SPD_SHI:
394 altbaud = 230400;
395 break;
396 case UPF_SPD_WARP:
397 altbaud = 460800;
398 break;
399 default:
400 altbaud = 38400;
401 break;
402 }
403
404 for (try = 0; try < 2; try++) {
405 baud = tty_termios_baud_rate(termios);
406
407 /*
408 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
409 * Die! Die! Die!
410 */
411 if (try == 0 && baud == 38400)
412 baud = altbaud;
413
414 /*
415 * Special case: B0 rate.
416 */
417 if (baud == 0) {
418 hung_up = 1;
419 baud = 9600;
420 }
421
422 if (baud >= min && baud <= max)
423 return baud;
424
425 /*
426 * Oops, the quotient was zero. Try again with
427 * the old baud rate if possible.
428 */
429 termios->c_cflag &= ~CBAUD;
430 if (old) {
431 baud = tty_termios_baud_rate(old);
432 if (!hung_up)
433 tty_termios_encode_baud_rate(termios,
434 baud, baud);
435 old = NULL;
436 continue;
437 }
438
439 /*
440 * As a last resort, if the range cannot be met then clip to
441 * the nearest chip supported rate.
442 */
443 if (!hung_up) {
444 if (baud <= min)
445 tty_termios_encode_baud_rate(termios,
446 min + 1, min + 1);
447 else
448 tty_termios_encode_baud_rate(termios,
449 max - 1, max - 1);
450 }
451 }
452 /* Should never happen */
453 WARN_ON(1);
454 return 0;
455}
456EXPORT_SYMBOL(uart_get_baud_rate);
457
458/**
459 * uart_get_divisor - return uart clock divisor
460 * @port: uart_port structure describing the port
461 * @baud: desired baud rate
462 *
463 * Calculate the divisor (baud_base / baud) for the specified @baud,
464 * appropriately rounded.
465 *
466 * If 38400 baud and custom divisor is selected, return the custom divisor
467 * instead.
468 *
469 * Locking: caller dependent
470 */
471unsigned int
472uart_get_divisor(struct uart_port *port, unsigned int baud)
473{
474 unsigned int quot;
475
476 /*
477 * Old custom speed handling.
478 */
479 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
480 quot = port->custom_divisor;
481 else
482 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
483
484 return quot;
485}
486EXPORT_SYMBOL(uart_get_divisor);
487
488/* Caller holds port mutex */
489static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
490 const struct ktermios *old_termios)
491{
492 struct uart_port *uport = uart_port_check(state);
493 struct ktermios *termios;
494 int hw_stopped;
495
496 /*
497 * If we have no tty, termios, or the port does not exist,
498 * then we can't set the parameters for this port.
499 */
500 if (!tty || uport->type == PORT_UNKNOWN)
501 return;
502
503 termios = &tty->termios;
504 uport->ops->set_termios(uport, termios, old_termios);
505
506 /*
507 * Set modem status enables based on termios cflag
508 */
509 spin_lock_irq(&uport->lock);
510 if (termios->c_cflag & CRTSCTS)
511 uport->status |= UPSTAT_CTS_ENABLE;
512 else
513 uport->status &= ~UPSTAT_CTS_ENABLE;
514
515 if (termios->c_cflag & CLOCAL)
516 uport->status &= ~UPSTAT_DCD_ENABLE;
517 else
518 uport->status |= UPSTAT_DCD_ENABLE;
519
520 /* reset sw-assisted CTS flow control based on (possibly) new mode */
521 hw_stopped = uport->hw_stopped;
522 uport->hw_stopped = uart_softcts_mode(uport) &&
523 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
524 if (uport->hw_stopped) {
525 if (!hw_stopped)
526 uport->ops->stop_tx(uport);
527 } else {
528 if (hw_stopped)
529 __uart_start(tty);
530 }
531 spin_unlock_irq(&uport->lock);
532}
533
534static int uart_put_char(struct tty_struct *tty, unsigned char c)
535{
536 struct uart_state *state = tty->driver_data;
537 struct uart_port *port;
538 struct circ_buf *circ;
539 unsigned long flags;
540 int ret = 0;
541
542 circ = &state->xmit;
543 port = uart_port_lock(state, flags);
544 if (!circ->buf) {
545 uart_port_unlock(port, flags);
546 return 0;
547 }
548
549 if (port && uart_circ_chars_free(circ) != 0) {
550 circ->buf[circ->head] = c;
551 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
552 ret = 1;
553 }
554 uart_port_unlock(port, flags);
555 return ret;
556}
557
558static void uart_flush_chars(struct tty_struct *tty)
559{
560 uart_start(tty);
561}
562
563static int uart_write(struct tty_struct *tty,
564 const unsigned char *buf, int count)
565{
566 struct uart_state *state = tty->driver_data;
567 struct uart_port *port;
568 struct circ_buf *circ;
569 unsigned long flags;
570 int c, ret = 0;
571
572 /*
573 * This means you called this function _after_ the port was
574 * closed. No cookie for you.
575 */
576 if (!state) {
577 WARN_ON(1);
578 return -EL3HLT;
579 }
580
581 port = uart_port_lock(state, flags);
582 circ = &state->xmit;
583 if (!circ->buf) {
584 uart_port_unlock(port, flags);
585 return 0;
586 }
587
588 while (port) {
589 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
590 if (count < c)
591 c = count;
592 if (c <= 0)
593 break;
594 memcpy(circ->buf + circ->head, buf, c);
595 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
596 buf += c;
597 count -= c;
598 ret += c;
599 }
600
601 __uart_start(tty);
602 uart_port_unlock(port, flags);
603 return ret;
604}
605
606static unsigned int uart_write_room(struct tty_struct *tty)
607{
608 struct uart_state *state = tty->driver_data;
609 struct uart_port *port;
610 unsigned long flags;
611 unsigned int ret;
612
613 port = uart_port_lock(state, flags);
614 ret = uart_circ_chars_free(&state->xmit);
615 uart_port_unlock(port, flags);
616 return ret;
617}
618
619static unsigned int uart_chars_in_buffer(struct tty_struct *tty)
620{
621 struct uart_state *state = tty->driver_data;
622 struct uart_port *port;
623 unsigned long flags;
624 unsigned int ret;
625
626 port = uart_port_lock(state, flags);
627 ret = uart_circ_chars_pending(&state->xmit);
628 uart_port_unlock(port, flags);
629 return ret;
630}
631
632static void uart_flush_buffer(struct tty_struct *tty)
633{
634 struct uart_state *state = tty->driver_data;
635 struct uart_port *port;
636 unsigned long flags;
637
638 /*
639 * This means you called this function _after_ the port was
640 * closed. No cookie for you.
641 */
642 if (!state) {
643 WARN_ON(1);
644 return;
645 }
646
647 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
648
649 port = uart_port_lock(state, flags);
650 if (!port)
651 return;
652 uart_circ_clear(&state->xmit);
653 if (port->ops->flush_buffer)
654 port->ops->flush_buffer(port);
655 uart_port_unlock(port, flags);
656 tty_port_tty_wakeup(&state->port);
657}
658
659/*
660 * This function performs low-level write of high-priority XON/XOFF
661 * character and accounting for it.
662 *
663 * Requires uart_port to implement .serial_out().
664 */
665void uart_xchar_out(struct uart_port *uport, int offset)
666{
667 serial_port_out(uport, offset, uport->x_char);
668 uport->icount.tx++;
669 uport->x_char = 0;
670}
671EXPORT_SYMBOL_GPL(uart_xchar_out);
672
673/*
674 * This function is used to send a high-priority XON/XOFF character to
675 * the device
676 */
677static void uart_send_xchar(struct tty_struct *tty, char ch)
678{
679 struct uart_state *state = tty->driver_data;
680 struct uart_port *port;
681 unsigned long flags;
682
683 port = uart_port_ref(state);
684 if (!port)
685 return;
686
687 if (port->ops->send_xchar)
688 port->ops->send_xchar(port, ch);
689 else {
690 spin_lock_irqsave(&port->lock, flags);
691 port->x_char = ch;
692 if (ch)
693 port->ops->start_tx(port);
694 spin_unlock_irqrestore(&port->lock, flags);
695 }
696 uart_port_deref(port);
697}
698
699static void uart_throttle(struct tty_struct *tty)
700{
701 struct uart_state *state = tty->driver_data;
702 upstat_t mask = UPSTAT_SYNC_FIFO;
703 struct uart_port *port;
704
705 port = uart_port_ref(state);
706 if (!port)
707 return;
708
709 if (I_IXOFF(tty))
710 mask |= UPSTAT_AUTOXOFF;
711 if (C_CRTSCTS(tty))
712 mask |= UPSTAT_AUTORTS;
713
714 if (port->status & mask) {
715 port->ops->throttle(port);
716 mask &= ~port->status;
717 }
718
719 if (mask & UPSTAT_AUTORTS)
720 uart_clear_mctrl(port, TIOCM_RTS);
721
722 if (mask & UPSTAT_AUTOXOFF)
723 uart_send_xchar(tty, STOP_CHAR(tty));
724
725 uart_port_deref(port);
726}
727
728static void uart_unthrottle(struct tty_struct *tty)
729{
730 struct uart_state *state = tty->driver_data;
731 upstat_t mask = UPSTAT_SYNC_FIFO;
732 struct uart_port *port;
733
734 port = uart_port_ref(state);
735 if (!port)
736 return;
737
738 if (I_IXOFF(tty))
739 mask |= UPSTAT_AUTOXOFF;
740 if (C_CRTSCTS(tty))
741 mask |= UPSTAT_AUTORTS;
742
743 if (port->status & mask) {
744 port->ops->unthrottle(port);
745 mask &= ~port->status;
746 }
747
748 if (mask & UPSTAT_AUTORTS)
749 uart_set_mctrl(port, TIOCM_RTS);
750
751 if (mask & UPSTAT_AUTOXOFF)
752 uart_send_xchar(tty, START_CHAR(tty));
753
754 uart_port_deref(port);
755}
756
757static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
758{
759 struct uart_state *state = container_of(port, struct uart_state, port);
760 struct uart_port *uport;
761 int ret = -ENODEV;
762
763 /*
764 * Ensure the state we copy is consistent and no hardware changes
765 * occur as we go
766 */
767 mutex_lock(&port->mutex);
768 uport = uart_port_check(state);
769 if (!uport)
770 goto out;
771
772 retinfo->type = uport->type;
773 retinfo->line = uport->line;
774 retinfo->port = uport->iobase;
775 if (HIGH_BITS_OFFSET)
776 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
777 retinfo->irq = uport->irq;
778 retinfo->flags = (__force int)uport->flags;
779 retinfo->xmit_fifo_size = uport->fifosize;
780 retinfo->baud_base = uport->uartclk / 16;
781 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
782 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
783 ASYNC_CLOSING_WAIT_NONE :
784 jiffies_to_msecs(port->closing_wait) / 10;
785 retinfo->custom_divisor = uport->custom_divisor;
786 retinfo->hub6 = uport->hub6;
787 retinfo->io_type = uport->iotype;
788 retinfo->iomem_reg_shift = uport->regshift;
789 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
790
791 ret = 0;
792out:
793 mutex_unlock(&port->mutex);
794 return ret;
795}
796
797static int uart_get_info_user(struct tty_struct *tty,
798 struct serial_struct *ss)
799{
800 struct uart_state *state = tty->driver_data;
801 struct tty_port *port = &state->port;
802
803 return uart_get_info(port, ss) < 0 ? -EIO : 0;
804}
805
806static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
807 struct uart_state *state,
808 struct serial_struct *new_info)
809{
810 struct uart_port *uport = uart_port_check(state);
811 unsigned long new_port;
812 unsigned int change_irq, change_port, closing_wait;
813 unsigned int old_custom_divisor, close_delay;
814 upf_t old_flags, new_flags;
815 int retval = 0;
816
817 if (!uport)
818 return -EIO;
819
820 new_port = new_info->port;
821 if (HIGH_BITS_OFFSET)
822 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
823
824 new_info->irq = irq_canonicalize(new_info->irq);
825 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
826 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
827 ASYNC_CLOSING_WAIT_NONE :
828 msecs_to_jiffies(new_info->closing_wait * 10);
829
830
831 change_irq = !(uport->flags & UPF_FIXED_PORT)
832 && new_info->irq != uport->irq;
833
834 /*
835 * Since changing the 'type' of the port changes its resource
836 * allocations, we should treat type changes the same as
837 * IO port changes.
838 */
839 change_port = !(uport->flags & UPF_FIXED_PORT)
840 && (new_port != uport->iobase ||
841 (unsigned long)new_info->iomem_base != uport->mapbase ||
842 new_info->hub6 != uport->hub6 ||
843 new_info->io_type != uport->iotype ||
844 new_info->iomem_reg_shift != uport->regshift ||
845 new_info->type != uport->type);
846
847 old_flags = uport->flags;
848 new_flags = (__force upf_t)new_info->flags;
849 old_custom_divisor = uport->custom_divisor;
850
851 if (!capable(CAP_SYS_ADMIN)) {
852 retval = -EPERM;
853 if (change_irq || change_port ||
854 (new_info->baud_base != uport->uartclk / 16) ||
855 (close_delay != port->close_delay) ||
856 (closing_wait != port->closing_wait) ||
857 (new_info->xmit_fifo_size &&
858 new_info->xmit_fifo_size != uport->fifosize) ||
859 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
860 goto exit;
861 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
862 (new_flags & UPF_USR_MASK));
863 uport->custom_divisor = new_info->custom_divisor;
864 goto check_and_exit;
865 }
866
867 if (change_irq || change_port) {
868 retval = security_locked_down(LOCKDOWN_TIOCSSERIAL);
869 if (retval)
870 goto exit;
871 }
872
873 /*
874 * Ask the low level driver to verify the settings.
875 */
876 if (uport->ops->verify_port)
877 retval = uport->ops->verify_port(uport, new_info);
878
879 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
880 (new_info->baud_base < 9600))
881 retval = -EINVAL;
882
883 if (retval)
884 goto exit;
885
886 if (change_port || change_irq) {
887 retval = -EBUSY;
888
889 /*
890 * Make sure that we are the sole user of this port.
891 */
892 if (tty_port_users(port) > 1)
893 goto exit;
894
895 /*
896 * We need to shutdown the serial port at the old
897 * port/type/irq combination.
898 */
899 uart_shutdown(tty, state);
900 }
901
902 if (change_port) {
903 unsigned long old_iobase, old_mapbase;
904 unsigned int old_type, old_iotype, old_hub6, old_shift;
905
906 old_iobase = uport->iobase;
907 old_mapbase = uport->mapbase;
908 old_type = uport->type;
909 old_hub6 = uport->hub6;
910 old_iotype = uport->iotype;
911 old_shift = uport->regshift;
912
913 /*
914 * Free and release old regions
915 */
916 if (old_type != PORT_UNKNOWN && uport->ops->release_port)
917 uport->ops->release_port(uport);
918
919 uport->iobase = new_port;
920 uport->type = new_info->type;
921 uport->hub6 = new_info->hub6;
922 uport->iotype = new_info->io_type;
923 uport->regshift = new_info->iomem_reg_shift;
924 uport->mapbase = (unsigned long)new_info->iomem_base;
925
926 /*
927 * Claim and map the new regions
928 */
929 if (uport->type != PORT_UNKNOWN && uport->ops->request_port) {
930 retval = uport->ops->request_port(uport);
931 } else {
932 /* Always success - Jean II */
933 retval = 0;
934 }
935
936 /*
937 * If we fail to request resources for the
938 * new port, try to restore the old settings.
939 */
940 if (retval) {
941 uport->iobase = old_iobase;
942 uport->type = old_type;
943 uport->hub6 = old_hub6;
944 uport->iotype = old_iotype;
945 uport->regshift = old_shift;
946 uport->mapbase = old_mapbase;
947
948 if (old_type != PORT_UNKNOWN) {
949 retval = uport->ops->request_port(uport);
950 /*
951 * If we failed to restore the old settings,
952 * we fail like this.
953 */
954 if (retval)
955 uport->type = PORT_UNKNOWN;
956
957 /*
958 * We failed anyway.
959 */
960 retval = -EBUSY;
961 }
962
963 /* Added to return the correct error -Ram Gupta */
964 goto exit;
965 }
966 }
967
968 if (change_irq)
969 uport->irq = new_info->irq;
970 if (!(uport->flags & UPF_FIXED_PORT))
971 uport->uartclk = new_info->baud_base * 16;
972 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
973 (new_flags & UPF_CHANGE_MASK);
974 uport->custom_divisor = new_info->custom_divisor;
975 port->close_delay = close_delay;
976 port->closing_wait = closing_wait;
977 if (new_info->xmit_fifo_size)
978 uport->fifosize = new_info->xmit_fifo_size;
979
980 check_and_exit:
981 retval = 0;
982 if (uport->type == PORT_UNKNOWN)
983 goto exit;
984 if (tty_port_initialized(port)) {
985 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
986 old_custom_divisor != uport->custom_divisor) {
987 /*
988 * If they're setting up a custom divisor or speed,
989 * instead of clearing it, then bitch about it.
990 */
991 if (uport->flags & UPF_SPD_MASK) {
992 dev_notice_ratelimited(uport->dev,
993 "%s sets custom speed on %s. This is deprecated.\n",
994 current->comm,
995 tty_name(port->tty));
996 }
997 uart_change_speed(tty, state, NULL);
998 }
999 } else {
1000 retval = uart_startup(tty, state, 1);
1001 if (retval == 0)
1002 tty_port_set_initialized(port, true);
1003 if (retval > 0)
1004 retval = 0;
1005 }
1006 exit:
1007 return retval;
1008}
1009
1010static int uart_set_info_user(struct tty_struct *tty, struct serial_struct *ss)
1011{
1012 struct uart_state *state = tty->driver_data;
1013 struct tty_port *port = &state->port;
1014 int retval;
1015
1016 down_write(&tty->termios_rwsem);
1017 /*
1018 * This semaphore protects port->count. It is also
1019 * very useful to prevent opens. Also, take the
1020 * port configuration semaphore to make sure that a
1021 * module insertion/removal doesn't change anything
1022 * under us.
1023 */
1024 mutex_lock(&port->mutex);
1025 retval = uart_set_info(tty, port, state, ss);
1026 mutex_unlock(&port->mutex);
1027 up_write(&tty->termios_rwsem);
1028 return retval;
1029}
1030
1031/**
1032 * uart_get_lsr_info - get line status register info
1033 * @tty: tty associated with the UART
1034 * @state: UART being queried
1035 * @value: returned modem value
1036 */
1037static int uart_get_lsr_info(struct tty_struct *tty,
1038 struct uart_state *state, unsigned int __user *value)
1039{
1040 struct uart_port *uport = uart_port_check(state);
1041 unsigned int result;
1042
1043 result = uport->ops->tx_empty(uport);
1044
1045 /*
1046 * If we're about to load something into the transmit
1047 * register, we'll pretend the transmitter isn't empty to
1048 * avoid a race condition (depending on when the transmit
1049 * interrupt happens).
1050 */
1051 if (uport->x_char ||
1052 ((uart_circ_chars_pending(&state->xmit) > 0) &&
1053 !uart_tx_stopped(uport)))
1054 result &= ~TIOCSER_TEMT;
1055
1056 return put_user(result, value);
1057}
1058
1059static int uart_tiocmget(struct tty_struct *tty)
1060{
1061 struct uart_state *state = tty->driver_data;
1062 struct tty_port *port = &state->port;
1063 struct uart_port *uport;
1064 int result = -EIO;
1065
1066 mutex_lock(&port->mutex);
1067 uport = uart_port_check(state);
1068 if (!uport)
1069 goto out;
1070
1071 if (!tty_io_error(tty)) {
1072 result = uport->mctrl;
1073 spin_lock_irq(&uport->lock);
1074 result |= uport->ops->get_mctrl(uport);
1075 spin_unlock_irq(&uport->lock);
1076 }
1077out:
1078 mutex_unlock(&port->mutex);
1079 return result;
1080}
1081
1082static int
1083uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
1084{
1085 struct uart_state *state = tty->driver_data;
1086 struct tty_port *port = &state->port;
1087 struct uart_port *uport;
1088 int ret = -EIO;
1089
1090 mutex_lock(&port->mutex);
1091 uport = uart_port_check(state);
1092 if (!uport)
1093 goto out;
1094
1095 if (!tty_io_error(tty)) {
1096 uart_update_mctrl(uport, set, clear);
1097 ret = 0;
1098 }
1099out:
1100 mutex_unlock(&port->mutex);
1101 return ret;
1102}
1103
1104static int uart_break_ctl(struct tty_struct *tty, int break_state)
1105{
1106 struct uart_state *state = tty->driver_data;
1107 struct tty_port *port = &state->port;
1108 struct uart_port *uport;
1109 int ret = -EIO;
1110
1111 mutex_lock(&port->mutex);
1112 uport = uart_port_check(state);
1113 if (!uport)
1114 goto out;
1115
1116 if (uport->type != PORT_UNKNOWN && uport->ops->break_ctl)
1117 uport->ops->break_ctl(uport, break_state);
1118 ret = 0;
1119out:
1120 mutex_unlock(&port->mutex);
1121 return ret;
1122}
1123
1124static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state)
1125{
1126 struct tty_port *port = &state->port;
1127 struct uart_port *uport;
1128 int flags, ret;
1129
1130 if (!capable(CAP_SYS_ADMIN))
1131 return -EPERM;
1132
1133 /*
1134 * Take the per-port semaphore. This prevents count from
1135 * changing, and hence any extra opens of the port while
1136 * we're auto-configuring.
1137 */
1138 if (mutex_lock_interruptible(&port->mutex))
1139 return -ERESTARTSYS;
1140
1141 uport = uart_port_check(state);
1142 if (!uport) {
1143 ret = -EIO;
1144 goto out;
1145 }
1146
1147 ret = -EBUSY;
1148 if (tty_port_users(port) == 1) {
1149 uart_shutdown(tty, state);
1150
1151 /*
1152 * If we already have a port type configured,
1153 * we must release its resources.
1154 */
1155 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
1156 uport->ops->release_port(uport);
1157
1158 flags = UART_CONFIG_TYPE;
1159 if (uport->flags & UPF_AUTO_IRQ)
1160 flags |= UART_CONFIG_IRQ;
1161
1162 /*
1163 * This will claim the ports resources if
1164 * a port is found.
1165 */
1166 uport->ops->config_port(uport, flags);
1167
1168 ret = uart_startup(tty, state, 1);
1169 if (ret == 0)
1170 tty_port_set_initialized(port, true);
1171 if (ret > 0)
1172 ret = 0;
1173 }
1174out:
1175 mutex_unlock(&port->mutex);
1176 return ret;
1177}
1178
1179static void uart_enable_ms(struct uart_port *uport)
1180{
1181 /*
1182 * Force modem status interrupts on
1183 */
1184 if (uport->ops->enable_ms)
1185 uport->ops->enable_ms(uport);
1186}
1187
1188/*
1189 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1190 * - mask passed in arg for lines of interest
1191 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1192 * Caller should use TIOCGICOUNT to see which one it was
1193 *
1194 * FIXME: This wants extracting into a common all driver implementation
1195 * of TIOCMWAIT using tty_port.
1196 */
1197static int uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1198{
1199 struct uart_port *uport;
1200 struct tty_port *port = &state->port;
1201 DECLARE_WAITQUEUE(wait, current);
1202 struct uart_icount cprev, cnow;
1203 int ret;
1204
1205 /*
1206 * note the counters on entry
1207 */
1208 uport = uart_port_ref(state);
1209 if (!uport)
1210 return -EIO;
1211 spin_lock_irq(&uport->lock);
1212 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1213 uart_enable_ms(uport);
1214 spin_unlock_irq(&uport->lock);
1215
1216 add_wait_queue(&port->delta_msr_wait, &wait);
1217 for (;;) {
1218 spin_lock_irq(&uport->lock);
1219 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1220 spin_unlock_irq(&uport->lock);
1221
1222 set_current_state(TASK_INTERRUPTIBLE);
1223
1224 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1225 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1226 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1227 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1228 ret = 0;
1229 break;
1230 }
1231
1232 schedule();
1233
1234 /* see if a signal did it */
1235 if (signal_pending(current)) {
1236 ret = -ERESTARTSYS;
1237 break;
1238 }
1239
1240 cprev = cnow;
1241 }
1242 __set_current_state(TASK_RUNNING);
1243 remove_wait_queue(&port->delta_msr_wait, &wait);
1244 uart_port_deref(uport);
1245
1246 return ret;
1247}
1248
1249/*
1250 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1251 * Return: write counters to the user passed counter struct
1252 * NB: both 1->0 and 0->1 transitions are counted except for
1253 * RI where only 0->1 is counted.
1254 */
1255static int uart_get_icount(struct tty_struct *tty,
1256 struct serial_icounter_struct *icount)
1257{
1258 struct uart_state *state = tty->driver_data;
1259 struct uart_icount cnow;
1260 struct uart_port *uport;
1261
1262 uport = uart_port_ref(state);
1263 if (!uport)
1264 return -EIO;
1265 spin_lock_irq(&uport->lock);
1266 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1267 spin_unlock_irq(&uport->lock);
1268 uart_port_deref(uport);
1269
1270 icount->cts = cnow.cts;
1271 icount->dsr = cnow.dsr;
1272 icount->rng = cnow.rng;
1273 icount->dcd = cnow.dcd;
1274 icount->rx = cnow.rx;
1275 icount->tx = cnow.tx;
1276 icount->frame = cnow.frame;
1277 icount->overrun = cnow.overrun;
1278 icount->parity = cnow.parity;
1279 icount->brk = cnow.brk;
1280 icount->buf_overrun = cnow.buf_overrun;
1281
1282 return 0;
1283}
1284
1285#define SER_RS485_LEGACY_FLAGS (SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | \
1286 SER_RS485_RTS_AFTER_SEND | SER_RS485_RX_DURING_TX | \
1287 SER_RS485_TERMINATE_BUS)
1288
1289static int uart_check_rs485_flags(struct uart_port *port, struct serial_rs485 *rs485)
1290{
1291 u32 flags = rs485->flags;
1292
1293 /* Don't return -EINVAL for unsupported legacy flags */
1294 flags &= ~SER_RS485_LEGACY_FLAGS;
1295
1296 /*
1297 * For any bit outside of the legacy ones that is not supported by
1298 * the driver, return -EINVAL.
1299 */
1300 if (flags & ~port->rs485_supported.flags)
1301 return -EINVAL;
1302
1303 /* Asking for address w/o addressing mode? */
1304 if (!(rs485->flags & SER_RS485_ADDRB) &&
1305 (rs485->flags & (SER_RS485_ADDR_RECV|SER_RS485_ADDR_DEST)))
1306 return -EINVAL;
1307
1308 /* Address given but not enabled? */
1309 if (!(rs485->flags & SER_RS485_ADDR_RECV) && rs485->addr_recv)
1310 return -EINVAL;
1311 if (!(rs485->flags & SER_RS485_ADDR_DEST) && rs485->addr_dest)
1312 return -EINVAL;
1313
1314 return 0;
1315}
1316
1317static void uart_sanitize_serial_rs485_delays(struct uart_port *port,
1318 struct serial_rs485 *rs485)
1319{
1320 if (!port->rs485_supported.delay_rts_before_send) {
1321 if (rs485->delay_rts_before_send) {
1322 dev_warn_ratelimited(port->dev,
1323 "%s (%d): RTS delay before sending not supported\n",
1324 port->name, port->line);
1325 }
1326 rs485->delay_rts_before_send = 0;
1327 } else if (rs485->delay_rts_before_send > RS485_MAX_RTS_DELAY) {
1328 rs485->delay_rts_before_send = RS485_MAX_RTS_DELAY;
1329 dev_warn_ratelimited(port->dev,
1330 "%s (%d): RTS delay before sending clamped to %u ms\n",
1331 port->name, port->line, rs485->delay_rts_before_send);
1332 }
1333
1334 if (!port->rs485_supported.delay_rts_after_send) {
1335 if (rs485->delay_rts_after_send) {
1336 dev_warn_ratelimited(port->dev,
1337 "%s (%d): RTS delay after sending not supported\n",
1338 port->name, port->line);
1339 }
1340 rs485->delay_rts_after_send = 0;
1341 } else if (rs485->delay_rts_after_send > RS485_MAX_RTS_DELAY) {
1342 rs485->delay_rts_after_send = RS485_MAX_RTS_DELAY;
1343 dev_warn_ratelimited(port->dev,
1344 "%s (%d): RTS delay after sending clamped to %u ms\n",
1345 port->name, port->line, rs485->delay_rts_after_send);
1346 }
1347}
1348
1349static void uart_sanitize_serial_rs485(struct uart_port *port, struct serial_rs485 *rs485)
1350{
1351 u32 supported_flags = port->rs485_supported.flags;
1352
1353 if (!(rs485->flags & SER_RS485_ENABLED)) {
1354 memset(rs485, 0, sizeof(*rs485));
1355 return;
1356 }
1357
1358 /* Pick sane settings if the user hasn't */
1359 if ((supported_flags & (SER_RS485_RTS_ON_SEND|SER_RS485_RTS_AFTER_SEND)) &&
1360 !(rs485->flags & SER_RS485_RTS_ON_SEND) ==
1361 !(rs485->flags & SER_RS485_RTS_AFTER_SEND)) {
1362 dev_warn_ratelimited(port->dev,
1363 "%s (%d): invalid RTS setting, using RTS_ON_SEND instead\n",
1364 port->name, port->line);
1365 rs485->flags |= SER_RS485_RTS_ON_SEND;
1366 rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
1367 supported_flags |= SER_RS485_RTS_ON_SEND|SER_RS485_RTS_AFTER_SEND;
1368 }
1369
1370 rs485->flags &= supported_flags;
1371
1372 uart_sanitize_serial_rs485_delays(port, rs485);
1373
1374 /* Return clean padding area to userspace */
1375 memset(rs485->padding0, 0, sizeof(rs485->padding0));
1376 memset(rs485->padding1, 0, sizeof(rs485->padding1));
1377}
1378
1379static void uart_set_rs485_termination(struct uart_port *port,
1380 const struct serial_rs485 *rs485)
1381{
1382 if (!(rs485->flags & SER_RS485_ENABLED))
1383 return;
1384
1385 gpiod_set_value_cansleep(port->rs485_term_gpio,
1386 !!(rs485->flags & SER_RS485_TERMINATE_BUS));
1387}
1388
1389static int uart_rs485_config(struct uart_port *port)
1390{
1391 struct serial_rs485 *rs485 = &port->rs485;
1392 int ret;
1393
1394 uart_sanitize_serial_rs485(port, rs485);
1395 uart_set_rs485_termination(port, rs485);
1396
1397 ret = port->rs485_config(port, NULL, rs485);
1398 if (ret)
1399 memset(rs485, 0, sizeof(*rs485));
1400
1401 return ret;
1402}
1403
1404static int uart_get_rs485_config(struct uart_port *port,
1405 struct serial_rs485 __user *rs485)
1406{
1407 unsigned long flags;
1408 struct serial_rs485 aux;
1409
1410 spin_lock_irqsave(&port->lock, flags);
1411 aux = port->rs485;
1412 spin_unlock_irqrestore(&port->lock, flags);
1413
1414 if (copy_to_user(rs485, &aux, sizeof(aux)))
1415 return -EFAULT;
1416
1417 return 0;
1418}
1419
1420static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port,
1421 struct serial_rs485 __user *rs485_user)
1422{
1423 struct serial_rs485 rs485;
1424 int ret;
1425 unsigned long flags;
1426
1427 if (!port->rs485_config)
1428 return -ENOTTY;
1429
1430 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1431 return -EFAULT;
1432
1433 ret = uart_check_rs485_flags(port, &rs485);
1434 if (ret)
1435 return ret;
1436 uart_sanitize_serial_rs485(port, &rs485);
1437 uart_set_rs485_termination(port, &rs485);
1438
1439 spin_lock_irqsave(&port->lock, flags);
1440 ret = port->rs485_config(port, &tty->termios, &rs485);
1441 if (!ret) {
1442 port->rs485 = rs485;
1443
1444 /* Reset RTS and other mctrl lines when disabling RS485 */
1445 if (!(rs485.flags & SER_RS485_ENABLED))
1446 port->ops->set_mctrl(port, port->mctrl);
1447 }
1448 spin_unlock_irqrestore(&port->lock, flags);
1449 if (ret)
1450 return ret;
1451
1452 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1453 return -EFAULT;
1454
1455 return 0;
1456}
1457
1458static int uart_get_iso7816_config(struct uart_port *port,
1459 struct serial_iso7816 __user *iso7816)
1460{
1461 unsigned long flags;
1462 struct serial_iso7816 aux;
1463
1464 if (!port->iso7816_config)
1465 return -ENOTTY;
1466
1467 spin_lock_irqsave(&port->lock, flags);
1468 aux = port->iso7816;
1469 spin_unlock_irqrestore(&port->lock, flags);
1470
1471 if (copy_to_user(iso7816, &aux, sizeof(aux)))
1472 return -EFAULT;
1473
1474 return 0;
1475}
1476
1477static int uart_set_iso7816_config(struct uart_port *port,
1478 struct serial_iso7816 __user *iso7816_user)
1479{
1480 struct serial_iso7816 iso7816;
1481 int i, ret;
1482 unsigned long flags;
1483
1484 if (!port->iso7816_config)
1485 return -ENOTTY;
1486
1487 if (copy_from_user(&iso7816, iso7816_user, sizeof(*iso7816_user)))
1488 return -EFAULT;
1489
1490 /*
1491 * There are 5 words reserved for future use. Check that userspace
1492 * doesn't put stuff in there to prevent breakages in the future.
1493 */
1494 for (i = 0; i < 5; i++)
1495 if (iso7816.reserved[i])
1496 return -EINVAL;
1497
1498 spin_lock_irqsave(&port->lock, flags);
1499 ret = port->iso7816_config(port, &iso7816);
1500 spin_unlock_irqrestore(&port->lock, flags);
1501 if (ret)
1502 return ret;
1503
1504 if (copy_to_user(iso7816_user, &port->iso7816, sizeof(port->iso7816)))
1505 return -EFAULT;
1506
1507 return 0;
1508}
1509
1510/*
1511 * Called via sys_ioctl. We can use spin_lock_irq() here.
1512 */
1513static int
1514uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
1515{
1516 struct uart_state *state = tty->driver_data;
1517 struct tty_port *port = &state->port;
1518 struct uart_port *uport;
1519 void __user *uarg = (void __user *)arg;
1520 int ret = -ENOIOCTLCMD;
1521
1522
1523 /*
1524 * These ioctls don't rely on the hardware to be present.
1525 */
1526 switch (cmd) {
1527 case TIOCSERCONFIG:
1528 down_write(&tty->termios_rwsem);
1529 ret = uart_do_autoconfig(tty, state);
1530 up_write(&tty->termios_rwsem);
1531 break;
1532 }
1533
1534 if (ret != -ENOIOCTLCMD)
1535 goto out;
1536
1537 if (tty_io_error(tty)) {
1538 ret = -EIO;
1539 goto out;
1540 }
1541
1542 /*
1543 * The following should only be used when hardware is present.
1544 */
1545 switch (cmd) {
1546 case TIOCMIWAIT:
1547 ret = uart_wait_modem_status(state, arg);
1548 break;
1549 }
1550
1551 if (ret != -ENOIOCTLCMD)
1552 goto out;
1553
1554 /* rs485_config requires more locking than others */
1555 if (cmd == TIOCGRS485)
1556 down_write(&tty->termios_rwsem);
1557
1558 mutex_lock(&port->mutex);
1559 uport = uart_port_check(state);
1560
1561 if (!uport || tty_io_error(tty)) {
1562 ret = -EIO;
1563 goto out_up;
1564 }
1565
1566 /*
1567 * All these rely on hardware being present and need to be
1568 * protected against the tty being hung up.
1569 */
1570
1571 switch (cmd) {
1572 case TIOCSERGETLSR: /* Get line status register */
1573 ret = uart_get_lsr_info(tty, state, uarg);
1574 break;
1575
1576 case TIOCGRS485:
1577 ret = uart_get_rs485_config(uport, uarg);
1578 break;
1579
1580 case TIOCSRS485:
1581 ret = uart_set_rs485_config(tty, uport, uarg);
1582 break;
1583
1584 case TIOCSISO7816:
1585 ret = uart_set_iso7816_config(state->uart_port, uarg);
1586 break;
1587
1588 case TIOCGISO7816:
1589 ret = uart_get_iso7816_config(state->uart_port, uarg);
1590 break;
1591 default:
1592 if (uport->ops->ioctl)
1593 ret = uport->ops->ioctl(uport, cmd, arg);
1594 break;
1595 }
1596out_up:
1597 mutex_unlock(&port->mutex);
1598 if (cmd == TIOCGRS485)
1599 up_write(&tty->termios_rwsem);
1600out:
1601 return ret;
1602}
1603
1604static void uart_set_ldisc(struct tty_struct *tty)
1605{
1606 struct uart_state *state = tty->driver_data;
1607 struct uart_port *uport;
1608 struct tty_port *port = &state->port;
1609
1610 if (!tty_port_initialized(port))
1611 return;
1612
1613 mutex_lock(&state->port.mutex);
1614 uport = uart_port_check(state);
1615 if (uport && uport->ops->set_ldisc)
1616 uport->ops->set_ldisc(uport, &tty->termios);
1617 mutex_unlock(&state->port.mutex);
1618}
1619
1620static void uart_set_termios(struct tty_struct *tty,
1621 const struct ktermios *old_termios)
1622{
1623 struct uart_state *state = tty->driver_data;
1624 struct uart_port *uport;
1625 unsigned int cflag = tty->termios.c_cflag;
1626 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1627 bool sw_changed = false;
1628
1629 mutex_lock(&state->port.mutex);
1630 uport = uart_port_check(state);
1631 if (!uport)
1632 goto out;
1633
1634 /*
1635 * Drivers doing software flow control also need to know
1636 * about changes to these input settings.
1637 */
1638 if (uport->flags & UPF_SOFT_FLOW) {
1639 iflag_mask |= IXANY|IXON|IXOFF;
1640 sw_changed =
1641 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1642 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1643 }
1644
1645 /*
1646 * These are the bits that are used to setup various
1647 * flags in the low level driver. We can ignore the Bfoo
1648 * bits in c_cflag; c_[io]speed will always be set
1649 * appropriately by set_termios() in tty_ioctl.c
1650 */
1651 if ((cflag ^ old_termios->c_cflag) == 0 &&
1652 tty->termios.c_ospeed == old_termios->c_ospeed &&
1653 tty->termios.c_ispeed == old_termios->c_ispeed &&
1654 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1655 !sw_changed) {
1656 goto out;
1657 }
1658
1659 uart_change_speed(tty, state, old_termios);
1660 /* reload cflag from termios; port driver may have overridden flags */
1661 cflag = tty->termios.c_cflag;
1662
1663 /* Handle transition to B0 status */
1664 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1665 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1666 /* Handle transition away from B0 status */
1667 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1668 unsigned int mask = TIOCM_DTR;
1669
1670 if (!(cflag & CRTSCTS) || !tty_throttled(tty))
1671 mask |= TIOCM_RTS;
1672 uart_set_mctrl(uport, mask);
1673 }
1674out:
1675 mutex_unlock(&state->port.mutex);
1676}
1677
1678/*
1679 * Calls to uart_close() are serialised via the tty_lock in
1680 * drivers/tty/tty_io.c:tty_release()
1681 * drivers/tty/tty_io.c:do_tty_hangup()
1682 */
1683static void uart_close(struct tty_struct *tty, struct file *filp)
1684{
1685 struct uart_state *state = tty->driver_data;
1686
1687 if (!state) {
1688 struct uart_driver *drv = tty->driver->driver_state;
1689 struct tty_port *port;
1690
1691 state = drv->state + tty->index;
1692 port = &state->port;
1693 spin_lock_irq(&port->lock);
1694 --port->count;
1695 spin_unlock_irq(&port->lock);
1696 return;
1697 }
1698
1699 pr_debug("uart_close(%d) called\n", tty->index);
1700
1701 tty_port_close(tty->port, tty, filp);
1702}
1703
1704static void uart_tty_port_shutdown(struct tty_port *port)
1705{
1706 struct uart_state *state = container_of(port, struct uart_state, port);
1707 struct uart_port *uport = uart_port_check(state);
1708 char *buf;
1709
1710 /*
1711 * At this point, we stop accepting input. To do this, we
1712 * disable the receive line status interrupts.
1713 */
1714 if (WARN(!uport, "detached port still initialized!\n"))
1715 return;
1716
1717 spin_lock_irq(&uport->lock);
1718 uport->ops->stop_rx(uport);
1719 spin_unlock_irq(&uport->lock);
1720
1721 uart_port_shutdown(port);
1722
1723 /*
1724 * It's possible for shutdown to be called after suspend if we get
1725 * a DCD drop (hangup) at just the right time. Clear suspended bit so
1726 * we don't try to resume a port that has been shutdown.
1727 */
1728 tty_port_set_suspended(port, 0);
1729
1730 /*
1731 * Free the transmit buffer.
1732 */
1733 spin_lock_irq(&uport->lock);
1734 buf = state->xmit.buf;
1735 state->xmit.buf = NULL;
1736 spin_unlock_irq(&uport->lock);
1737
1738 free_page((unsigned long)buf);
1739
1740 uart_change_pm(state, UART_PM_STATE_OFF);
1741}
1742
1743static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1744{
1745 struct uart_state *state = tty->driver_data;
1746 struct uart_port *port;
1747 unsigned long char_time, expire, fifo_timeout;
1748
1749 port = uart_port_ref(state);
1750 if (!port)
1751 return;
1752
1753 if (port->type == PORT_UNKNOWN || port->fifosize == 0) {
1754 uart_port_deref(port);
1755 return;
1756 }
1757
1758 /*
1759 * Set the check interval to be 1/5 of the estimated time to
1760 * send a single character, and make it at least 1. The check
1761 * interval should also be less than the timeout.
1762 *
1763 * Note: we have to use pretty tight timings here to satisfy
1764 * the NIST-PCTS.
1765 */
1766 char_time = max(nsecs_to_jiffies(port->frame_time / 5), 1UL);
1767
1768 if (timeout && timeout < char_time)
1769 char_time = timeout;
1770
1771 if (!uart_cts_enabled(port)) {
1772 /*
1773 * If the transmitter hasn't cleared in twice the approximate
1774 * amount of time to send the entire FIFO, it probably won't
1775 * ever clear. This assumes the UART isn't doing flow
1776 * control, which is currently the case. Hence, if it ever
1777 * takes longer than FIFO timeout, this is probably due to a
1778 * UART bug of some kind. So, we clamp the timeout parameter at
1779 * 2 * FIFO timeout.
1780 */
1781 fifo_timeout = uart_fifo_timeout(port);
1782 if (timeout == 0 || timeout > 2 * fifo_timeout)
1783 timeout = 2 * fifo_timeout;
1784 }
1785
1786 expire = jiffies + timeout;
1787
1788 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1789 port->line, jiffies, expire);
1790
1791 /*
1792 * Check whether the transmitter is empty every 'char_time'.
1793 * 'timeout' / 'expire' give us the maximum amount of time
1794 * we wait.
1795 */
1796 while (!port->ops->tx_empty(port)) {
1797 msleep_interruptible(jiffies_to_msecs(char_time));
1798 if (signal_pending(current))
1799 break;
1800 if (timeout && time_after(jiffies, expire))
1801 break;
1802 }
1803 uart_port_deref(port);
1804}
1805
1806/*
1807 * Calls to uart_hangup() are serialised by the tty_lock in
1808 * drivers/tty/tty_io.c:do_tty_hangup()
1809 * This runs from a workqueue and can sleep for a _short_ time only.
1810 */
1811static void uart_hangup(struct tty_struct *tty)
1812{
1813 struct uart_state *state = tty->driver_data;
1814 struct tty_port *port = &state->port;
1815 struct uart_port *uport;
1816 unsigned long flags;
1817
1818 pr_debug("uart_hangup(%d)\n", tty->index);
1819
1820 mutex_lock(&port->mutex);
1821 uport = uart_port_check(state);
1822 WARN(!uport, "hangup of detached port!\n");
1823
1824 if (tty_port_active(port)) {
1825 uart_flush_buffer(tty);
1826 uart_shutdown(tty, state);
1827 spin_lock_irqsave(&port->lock, flags);
1828 port->count = 0;
1829 spin_unlock_irqrestore(&port->lock, flags);
1830 tty_port_set_active(port, 0);
1831 tty_port_tty_set(port, NULL);
1832 if (uport && !uart_console(uport))
1833 uart_change_pm(state, UART_PM_STATE_OFF);
1834 wake_up_interruptible(&port->open_wait);
1835 wake_up_interruptible(&port->delta_msr_wait);
1836 }
1837 mutex_unlock(&port->mutex);
1838}
1839
1840/* uport == NULL if uart_port has already been removed */
1841static void uart_port_shutdown(struct tty_port *port)
1842{
1843 struct uart_state *state = container_of(port, struct uart_state, port);
1844 struct uart_port *uport = uart_port_check(state);
1845
1846 /*
1847 * clear delta_msr_wait queue to avoid mem leaks: we may free
1848 * the irq here so the queue might never be woken up. Note
1849 * that we won't end up waiting on delta_msr_wait again since
1850 * any outstanding file descriptors should be pointing at
1851 * hung_up_tty_fops now.
1852 */
1853 wake_up_interruptible(&port->delta_msr_wait);
1854
1855 if (uport) {
1856 /* Free the IRQ and disable the port. */
1857 uport->ops->shutdown(uport);
1858
1859 /* Ensure that the IRQ handler isn't running on another CPU. */
1860 synchronize_irq(uport->irq);
1861 }
1862}
1863
1864static int uart_carrier_raised(struct tty_port *port)
1865{
1866 struct uart_state *state = container_of(port, struct uart_state, port);
1867 struct uart_port *uport;
1868 int mctrl;
1869
1870 uport = uart_port_ref(state);
1871 /*
1872 * Should never observe uport == NULL since checks for hangup should
1873 * abort the tty_port_block_til_ready() loop before checking for carrier
1874 * raised -- but report carrier raised if it does anyway so open will
1875 * continue and not sleep
1876 */
1877 if (WARN_ON(!uport))
1878 return 1;
1879 spin_lock_irq(&uport->lock);
1880 uart_enable_ms(uport);
1881 mctrl = uport->ops->get_mctrl(uport);
1882 spin_unlock_irq(&uport->lock);
1883 uart_port_deref(uport);
1884 if (mctrl & TIOCM_CAR)
1885 return 1;
1886 return 0;
1887}
1888
1889static void uart_dtr_rts(struct tty_port *port, int raise)
1890{
1891 struct uart_state *state = container_of(port, struct uart_state, port);
1892 struct uart_port *uport;
1893
1894 uport = uart_port_ref(state);
1895 if (!uport)
1896 return;
1897 uart_port_dtr_rts(uport, raise);
1898 uart_port_deref(uport);
1899}
1900
1901static int uart_install(struct tty_driver *driver, struct tty_struct *tty)
1902{
1903 struct uart_driver *drv = driver->driver_state;
1904 struct uart_state *state = drv->state + tty->index;
1905
1906 tty->driver_data = state;
1907
1908 return tty_standard_install(driver, tty);
1909}
1910
1911/*
1912 * Calls to uart_open are serialised by the tty_lock in
1913 * drivers/tty/tty_io.c:tty_open()
1914 * Note that if this fails, then uart_close() _will_ be called.
1915 *
1916 * In time, we want to scrap the "opening nonpresent ports"
1917 * behaviour and implement an alternative way for setserial
1918 * to set base addresses/ports/types. This will allow us to
1919 * get rid of a certain amount of extra tests.
1920 */
1921static int uart_open(struct tty_struct *tty, struct file *filp)
1922{
1923 struct uart_state *state = tty->driver_data;
1924 int retval;
1925
1926 retval = tty_port_open(&state->port, tty, filp);
1927 if (retval > 0)
1928 retval = 0;
1929
1930 return retval;
1931}
1932
1933static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1934{
1935 struct uart_state *state = container_of(port, struct uart_state, port);
1936 struct uart_port *uport;
1937 int ret;
1938
1939 uport = uart_port_check(state);
1940 if (!uport || uport->flags & UPF_DEAD)
1941 return -ENXIO;
1942
1943 /*
1944 * Start up the serial port.
1945 */
1946 ret = uart_startup(tty, state, 0);
1947 if (ret > 0)
1948 tty_port_set_active(port, 1);
1949
1950 return ret;
1951}
1952
1953static const char *uart_type(struct uart_port *port)
1954{
1955 const char *str = NULL;
1956
1957 if (port->ops->type)
1958 str = port->ops->type(port);
1959
1960 if (!str)
1961 str = "unknown";
1962
1963 return str;
1964}
1965
1966#ifdef CONFIG_PROC_FS
1967
1968static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1969{
1970 struct uart_state *state = drv->state + i;
1971 struct tty_port *port = &state->port;
1972 enum uart_pm_state pm_state;
1973 struct uart_port *uport;
1974 char stat_buf[32];
1975 unsigned int status;
1976 int mmio;
1977
1978 mutex_lock(&port->mutex);
1979 uport = uart_port_check(state);
1980 if (!uport)
1981 goto out;
1982
1983 mmio = uport->iotype >= UPIO_MEM;
1984 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1985 uport->line, uart_type(uport),
1986 mmio ? "mmio:0x" : "port:",
1987 mmio ? (unsigned long long)uport->mapbase
1988 : (unsigned long long)uport->iobase,
1989 uport->irq);
1990
1991 if (uport->type == PORT_UNKNOWN) {
1992 seq_putc(m, '\n');
1993 goto out;
1994 }
1995
1996 if (capable(CAP_SYS_ADMIN)) {
1997 pm_state = state->pm_state;
1998 if (pm_state != UART_PM_STATE_ON)
1999 uart_change_pm(state, UART_PM_STATE_ON);
2000 spin_lock_irq(&uport->lock);
2001 status = uport->ops->get_mctrl(uport);
2002 spin_unlock_irq(&uport->lock);
2003 if (pm_state != UART_PM_STATE_ON)
2004 uart_change_pm(state, pm_state);
2005
2006 seq_printf(m, " tx:%d rx:%d",
2007 uport->icount.tx, uport->icount.rx);
2008 if (uport->icount.frame)
2009 seq_printf(m, " fe:%d", uport->icount.frame);
2010 if (uport->icount.parity)
2011 seq_printf(m, " pe:%d", uport->icount.parity);
2012 if (uport->icount.brk)
2013 seq_printf(m, " brk:%d", uport->icount.brk);
2014 if (uport->icount.overrun)
2015 seq_printf(m, " oe:%d", uport->icount.overrun);
2016 if (uport->icount.buf_overrun)
2017 seq_printf(m, " bo:%d", uport->icount.buf_overrun);
2018
2019#define INFOBIT(bit, str) \
2020 if (uport->mctrl & (bit)) \
2021 strncat(stat_buf, (str), sizeof(stat_buf) - \
2022 strlen(stat_buf) - 2)
2023#define STATBIT(bit, str) \
2024 if (status & (bit)) \
2025 strncat(stat_buf, (str), sizeof(stat_buf) - \
2026 strlen(stat_buf) - 2)
2027
2028 stat_buf[0] = '\0';
2029 stat_buf[1] = '\0';
2030 INFOBIT(TIOCM_RTS, "|RTS");
2031 STATBIT(TIOCM_CTS, "|CTS");
2032 INFOBIT(TIOCM_DTR, "|DTR");
2033 STATBIT(TIOCM_DSR, "|DSR");
2034 STATBIT(TIOCM_CAR, "|CD");
2035 STATBIT(TIOCM_RNG, "|RI");
2036 if (stat_buf[0])
2037 stat_buf[0] = ' ';
2038
2039 seq_puts(m, stat_buf);
2040 }
2041 seq_putc(m, '\n');
2042#undef STATBIT
2043#undef INFOBIT
2044out:
2045 mutex_unlock(&port->mutex);
2046}
2047
2048static int uart_proc_show(struct seq_file *m, void *v)
2049{
2050 struct tty_driver *ttydrv = m->private;
2051 struct uart_driver *drv = ttydrv->driver_state;
2052 int i;
2053
2054 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
2055 for (i = 0; i < drv->nr; i++)
2056 uart_line_info(m, drv, i);
2057 return 0;
2058}
2059#endif
2060
2061static void uart_port_spin_lock_init(struct uart_port *port)
2062{
2063 spin_lock_init(&port->lock);
2064 lockdep_set_class(&port->lock, &port_lock_key);
2065}
2066
2067#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
2068/**
2069 * uart_console_write - write a console message to a serial port
2070 * @port: the port to write the message
2071 * @s: array of characters
2072 * @count: number of characters in string to write
2073 * @putchar: function to write character to port
2074 */
2075void uart_console_write(struct uart_port *port, const char *s,
2076 unsigned int count,
2077 void (*putchar)(struct uart_port *, unsigned char))
2078{
2079 unsigned int i;
2080
2081 for (i = 0; i < count; i++, s++) {
2082 if (*s == '\n')
2083 putchar(port, '\r');
2084 putchar(port, *s);
2085 }
2086}
2087EXPORT_SYMBOL_GPL(uart_console_write);
2088
2089/**
2090 * uart_get_console - get uart port for console
2091 * @ports: ports to search in
2092 * @nr: number of @ports
2093 * @co: console to search for
2094 * Returns: uart_port for the console @co
2095 *
2096 * Check whether an invalid uart number has been specified (as @co->index), and
2097 * if so, search for the first available port that does have console support.
2098 */
2099struct uart_port * __init
2100uart_get_console(struct uart_port *ports, int nr, struct console *co)
2101{
2102 int idx = co->index;
2103
2104 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
2105 ports[idx].membase == NULL))
2106 for (idx = 0; idx < nr; idx++)
2107 if (ports[idx].iobase != 0 ||
2108 ports[idx].membase != NULL)
2109 break;
2110
2111 co->index = idx;
2112
2113 return ports + idx;
2114}
2115
2116/**
2117 * uart_parse_earlycon - Parse earlycon options
2118 * @p: ptr to 2nd field (ie., just beyond '<name>,')
2119 * @iotype: ptr for decoded iotype (out)
2120 * @addr: ptr for decoded mapbase/iobase (out)
2121 * @options: ptr for <options> field; %NULL if not present (out)
2122 *
2123 * Decodes earlycon kernel command line parameters of the form:
2124 * * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
2125 * * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
2126 *
2127 * The optional form:
2128 * * earlycon=<name>,0x<addr>,<options>
2129 * * console=<name>,0x<addr>,<options>
2130 *
2131 * is also accepted; the returned @iotype will be %UPIO_MEM.
2132 *
2133 * Returns: 0 on success or -%EINVAL on failure
2134 */
2135int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
2136 char **options)
2137{
2138 if (strncmp(p, "mmio,", 5) == 0) {
2139 *iotype = UPIO_MEM;
2140 p += 5;
2141 } else if (strncmp(p, "mmio16,", 7) == 0) {
2142 *iotype = UPIO_MEM16;
2143 p += 7;
2144 } else if (strncmp(p, "mmio32,", 7) == 0) {
2145 *iotype = UPIO_MEM32;
2146 p += 7;
2147 } else if (strncmp(p, "mmio32be,", 9) == 0) {
2148 *iotype = UPIO_MEM32BE;
2149 p += 9;
2150 } else if (strncmp(p, "mmio32native,", 13) == 0) {
2151 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
2152 UPIO_MEM32BE : UPIO_MEM32;
2153 p += 13;
2154 } else if (strncmp(p, "io,", 3) == 0) {
2155 *iotype = UPIO_PORT;
2156 p += 3;
2157 } else if (strncmp(p, "0x", 2) == 0) {
2158 *iotype = UPIO_MEM;
2159 } else {
2160 return -EINVAL;
2161 }
2162
2163 /*
2164 * Before you replace it with kstrtoull(), think about options separator
2165 * (',') it will not tolerate
2166 */
2167 *addr = simple_strtoull(p, NULL, 0);
2168 p = strchr(p, ',');
2169 if (p)
2170 p++;
2171
2172 *options = p;
2173 return 0;
2174}
2175EXPORT_SYMBOL_GPL(uart_parse_earlycon);
2176
2177/**
2178 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
2179 * @options: pointer to option string
2180 * @baud: pointer to an 'int' variable for the baud rate.
2181 * @parity: pointer to an 'int' variable for the parity.
2182 * @bits: pointer to an 'int' variable for the number of data bits.
2183 * @flow: pointer to an 'int' variable for the flow control character.
2184 *
2185 * uart_parse_options() decodes a string containing the serial console
2186 * options. The format of the string is <baud><parity><bits><flow>,
2187 * eg: 115200n8r
2188 */
2189void
2190uart_parse_options(const char *options, int *baud, int *parity,
2191 int *bits, int *flow)
2192{
2193 const char *s = options;
2194
2195 *baud = simple_strtoul(s, NULL, 10);
2196 while (*s >= '0' && *s <= '9')
2197 s++;
2198 if (*s)
2199 *parity = *s++;
2200 if (*s)
2201 *bits = *s++ - '0';
2202 if (*s)
2203 *flow = *s;
2204}
2205EXPORT_SYMBOL_GPL(uart_parse_options);
2206
2207/**
2208 * uart_set_options - setup the serial console parameters
2209 * @port: pointer to the serial ports uart_port structure
2210 * @co: console pointer
2211 * @baud: baud rate
2212 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
2213 * @bits: number of data bits
2214 * @flow: flow control character - 'r' (rts)
2215 *
2216 * Locking: Caller must hold console_list_lock in order to serialize
2217 * early initialization of the serial-console lock.
2218 */
2219int
2220uart_set_options(struct uart_port *port, struct console *co,
2221 int baud, int parity, int bits, int flow)
2222{
2223 struct ktermios termios;
2224 static struct ktermios dummy;
2225
2226 /*
2227 * Ensure that the serial-console lock is initialised early.
2228 *
2229 * Note that the console-registered check is needed because
2230 * kgdboc can call uart_set_options() for an already registered
2231 * console via tty_find_polling_driver() and uart_poll_init().
2232 */
2233 if (!uart_console_registered_locked(port) && !port->console_reinit)
2234 uart_port_spin_lock_init(port);
2235
2236 memset(&termios, 0, sizeof(struct ktermios));
2237
2238 termios.c_cflag |= CREAD | HUPCL | CLOCAL;
2239 tty_termios_encode_baud_rate(&termios, baud, baud);
2240
2241 if (bits == 7)
2242 termios.c_cflag |= CS7;
2243 else
2244 termios.c_cflag |= CS8;
2245
2246 switch (parity) {
2247 case 'o': case 'O':
2248 termios.c_cflag |= PARODD;
2249 fallthrough;
2250 case 'e': case 'E':
2251 termios.c_cflag |= PARENB;
2252 break;
2253 }
2254
2255 if (flow == 'r')
2256 termios.c_cflag |= CRTSCTS;
2257
2258 /*
2259 * some uarts on other side don't support no flow control.
2260 * So we set * DTR in host uart to make them happy
2261 */
2262 port->mctrl |= TIOCM_DTR;
2263
2264 port->ops->set_termios(port, &termios, &dummy);
2265 /*
2266 * Allow the setting of the UART parameters with a NULL console
2267 * too:
2268 */
2269 if (co) {
2270 co->cflag = termios.c_cflag;
2271 co->ispeed = termios.c_ispeed;
2272 co->ospeed = termios.c_ospeed;
2273 }
2274
2275 return 0;
2276}
2277EXPORT_SYMBOL_GPL(uart_set_options);
2278#endif /* CONFIG_SERIAL_CORE_CONSOLE */
2279
2280/**
2281 * uart_change_pm - set power state of the port
2282 *
2283 * @state: port descriptor
2284 * @pm_state: new state
2285 *
2286 * Locking: port->mutex has to be held
2287 */
2288static void uart_change_pm(struct uart_state *state,
2289 enum uart_pm_state pm_state)
2290{
2291 struct uart_port *port = uart_port_check(state);
2292
2293 if (state->pm_state != pm_state) {
2294 if (port && port->ops->pm)
2295 port->ops->pm(port, pm_state, state->pm_state);
2296 state->pm_state = pm_state;
2297 }
2298}
2299
2300struct uart_match {
2301 struct uart_port *port;
2302 struct uart_driver *driver;
2303};
2304
2305static int serial_match_port(struct device *dev, void *data)
2306{
2307 struct uart_match *match = data;
2308 struct tty_driver *tty_drv = match->driver->tty_driver;
2309 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
2310 match->port->line;
2311
2312 return dev->devt == devt; /* Actually, only one tty per port */
2313}
2314
2315int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
2316{
2317 struct uart_state *state = drv->state + uport->line;
2318 struct tty_port *port = &state->port;
2319 struct device *tty_dev;
2320 struct uart_match match = {uport, drv};
2321
2322 mutex_lock(&port->mutex);
2323
2324 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2325 if (tty_dev && device_may_wakeup(tty_dev)) {
2326 enable_irq_wake(uport->irq);
2327 put_device(tty_dev);
2328 mutex_unlock(&port->mutex);
2329 return 0;
2330 }
2331 put_device(tty_dev);
2332
2333 /*
2334 * Nothing to do if the console is not suspending
2335 * except stop_rx to prevent any asynchronous data
2336 * over RX line. However ensure that we will be
2337 * able to Re-start_rx later.
2338 */
2339 if (!console_suspend_enabled && uart_console(uport)) {
2340 if (uport->ops->start_rx)
2341 uport->ops->stop_rx(uport);
2342 goto unlock;
2343 }
2344
2345 uport->suspended = 1;
2346
2347 if (tty_port_initialized(port)) {
2348 const struct uart_ops *ops = uport->ops;
2349 int tries;
2350 unsigned int mctrl;
2351
2352 tty_port_set_suspended(port, 1);
2353 tty_port_set_initialized(port, 0);
2354
2355 spin_lock_irq(&uport->lock);
2356 ops->stop_tx(uport);
2357 if (!(uport->rs485.flags & SER_RS485_ENABLED))
2358 ops->set_mctrl(uport, 0);
2359 /* save mctrl so it can be restored on resume */
2360 mctrl = uport->mctrl;
2361 uport->mctrl = 0;
2362 ops->stop_rx(uport);
2363 spin_unlock_irq(&uport->lock);
2364
2365 /*
2366 * Wait for the transmitter to empty.
2367 */
2368 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2369 msleep(10);
2370 if (!tries)
2371 dev_err(uport->dev, "%s: Unable to drain transmitter\n",
2372 uport->name);
2373
2374 ops->shutdown(uport);
2375 uport->mctrl = mctrl;
2376 }
2377
2378 /*
2379 * Disable the console device before suspending.
2380 */
2381 if (uart_console(uport))
2382 console_stop(uport->cons);
2383
2384 uart_change_pm(state, UART_PM_STATE_OFF);
2385unlock:
2386 mutex_unlock(&port->mutex);
2387
2388 return 0;
2389}
2390EXPORT_SYMBOL(uart_suspend_port);
2391
2392int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2393{
2394 struct uart_state *state = drv->state + uport->line;
2395 struct tty_port *port = &state->port;
2396 struct device *tty_dev;
2397 struct uart_match match = {uport, drv};
2398 struct ktermios termios;
2399
2400 mutex_lock(&port->mutex);
2401
2402 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2403 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2404 if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq))))
2405 disable_irq_wake(uport->irq);
2406 put_device(tty_dev);
2407 mutex_unlock(&port->mutex);
2408 return 0;
2409 }
2410 put_device(tty_dev);
2411 uport->suspended = 0;
2412
2413 /*
2414 * Re-enable the console device after suspending.
2415 */
2416 if (uart_console(uport)) {
2417 /*
2418 * First try to use the console cflag setting.
2419 */
2420 memset(&termios, 0, sizeof(struct ktermios));
2421 termios.c_cflag = uport->cons->cflag;
2422 termios.c_ispeed = uport->cons->ispeed;
2423 termios.c_ospeed = uport->cons->ospeed;
2424
2425 /*
2426 * If that's unset, use the tty termios setting.
2427 */
2428 if (port->tty && termios.c_cflag == 0)
2429 termios = port->tty->termios;
2430
2431 if (console_suspend_enabled)
2432 uart_change_pm(state, UART_PM_STATE_ON);
2433 uport->ops->set_termios(uport, &termios, NULL);
2434 if (!console_suspend_enabled && uport->ops->start_rx)
2435 uport->ops->start_rx(uport);
2436 if (console_suspend_enabled)
2437 console_start(uport->cons);
2438 }
2439
2440 if (tty_port_suspended(port)) {
2441 const struct uart_ops *ops = uport->ops;
2442 int ret;
2443
2444 uart_change_pm(state, UART_PM_STATE_ON);
2445 spin_lock_irq(&uport->lock);
2446 if (!(uport->rs485.flags & SER_RS485_ENABLED))
2447 ops->set_mctrl(uport, 0);
2448 spin_unlock_irq(&uport->lock);
2449 if (console_suspend_enabled || !uart_console(uport)) {
2450 /* Protected by port mutex for now */
2451 struct tty_struct *tty = port->tty;
2452
2453 ret = ops->startup(uport);
2454 if (ret == 0) {
2455 if (tty)
2456 uart_change_speed(tty, state, NULL);
2457 spin_lock_irq(&uport->lock);
2458 if (!(uport->rs485.flags & SER_RS485_ENABLED))
2459 ops->set_mctrl(uport, uport->mctrl);
2460 else
2461 uart_rs485_config(uport);
2462 ops->start_tx(uport);
2463 spin_unlock_irq(&uport->lock);
2464 tty_port_set_initialized(port, 1);
2465 } else {
2466 /*
2467 * Failed to resume - maybe hardware went away?
2468 * Clear the "initialized" flag so we won't try
2469 * to call the low level drivers shutdown method.
2470 */
2471 uart_shutdown(tty, state);
2472 }
2473 }
2474
2475 tty_port_set_suspended(port, 0);
2476 }
2477
2478 mutex_unlock(&port->mutex);
2479
2480 return 0;
2481}
2482EXPORT_SYMBOL(uart_resume_port);
2483
2484static inline void
2485uart_report_port(struct uart_driver *drv, struct uart_port *port)
2486{
2487 char address[64];
2488
2489 switch (port->iotype) {
2490 case UPIO_PORT:
2491 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2492 break;
2493 case UPIO_HUB6:
2494 snprintf(address, sizeof(address),
2495 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2496 break;
2497 case UPIO_MEM:
2498 case UPIO_MEM16:
2499 case UPIO_MEM32:
2500 case UPIO_MEM32BE:
2501 case UPIO_AU:
2502 case UPIO_TSI:
2503 snprintf(address, sizeof(address),
2504 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2505 break;
2506 default:
2507 strscpy(address, "*unknown*", sizeof(address));
2508 break;
2509 }
2510
2511 pr_info("%s%s%s at %s (irq = %d, base_baud = %d) is a %s\n",
2512 port->dev ? dev_name(port->dev) : "",
2513 port->dev ? ": " : "",
2514 port->name,
2515 address, port->irq, port->uartclk / 16, uart_type(port));
2516
2517 /* The magic multiplier feature is a bit obscure, so report it too. */
2518 if (port->flags & UPF_MAGIC_MULTIPLIER)
2519 pr_info("%s%s%s extra baud rates supported: %d, %d",
2520 port->dev ? dev_name(port->dev) : "",
2521 port->dev ? ": " : "",
2522 port->name,
2523 port->uartclk / 8, port->uartclk / 4);
2524}
2525
2526static void
2527uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2528 struct uart_port *port)
2529{
2530 unsigned int flags;
2531
2532 /*
2533 * If there isn't a port here, don't do anything further.
2534 */
2535 if (!port->iobase && !port->mapbase && !port->membase)
2536 return;
2537
2538 /*
2539 * Now do the auto configuration stuff. Note that config_port
2540 * is expected to claim the resources and map the port for us.
2541 */
2542 flags = 0;
2543 if (port->flags & UPF_AUTO_IRQ)
2544 flags |= UART_CONFIG_IRQ;
2545 if (port->flags & UPF_BOOT_AUTOCONF) {
2546 if (!(port->flags & UPF_FIXED_TYPE)) {
2547 port->type = PORT_UNKNOWN;
2548 flags |= UART_CONFIG_TYPE;
2549 }
2550 port->ops->config_port(port, flags);
2551 }
2552
2553 if (port->type != PORT_UNKNOWN) {
2554 unsigned long flags;
2555
2556 uart_report_port(drv, port);
2557
2558 /* Power up port for set_mctrl() */
2559 uart_change_pm(state, UART_PM_STATE_ON);
2560
2561 /*
2562 * Ensure that the modem control lines are de-activated.
2563 * keep the DTR setting that is set in uart_set_options()
2564 * We probably don't need a spinlock around this, but
2565 */
2566 spin_lock_irqsave(&port->lock, flags);
2567 port->mctrl &= TIOCM_DTR;
2568 if (!(port->rs485.flags & SER_RS485_ENABLED))
2569 port->ops->set_mctrl(port, port->mctrl);
2570 else
2571 uart_rs485_config(port);
2572 spin_unlock_irqrestore(&port->lock, flags);
2573
2574 /*
2575 * If this driver supports console, and it hasn't been
2576 * successfully registered yet, try to re-register it.
2577 * It may be that the port was not available.
2578 */
2579 if (port->cons && !console_is_registered(port->cons))
2580 register_console(port->cons);
2581
2582 /*
2583 * Power down all ports by default, except the
2584 * console if we have one.
2585 */
2586 if (!uart_console(port))
2587 uart_change_pm(state, UART_PM_STATE_OFF);
2588 }
2589}
2590
2591#ifdef CONFIG_CONSOLE_POLL
2592
2593static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2594{
2595 struct uart_driver *drv = driver->driver_state;
2596 struct uart_state *state = drv->state + line;
2597 struct tty_port *tport;
2598 struct uart_port *port;
2599 int baud = 9600;
2600 int bits = 8;
2601 int parity = 'n';
2602 int flow = 'n';
2603 int ret = 0;
2604
2605 tport = &state->port;
2606 mutex_lock(&tport->mutex);
2607
2608 port = uart_port_check(state);
2609 if (!port || !(port->ops->poll_get_char && port->ops->poll_put_char)) {
2610 ret = -1;
2611 goto out;
2612 }
2613
2614 if (port->ops->poll_init) {
2615 /*
2616 * We don't set initialized as we only initialized the hw,
2617 * e.g. state->xmit is still uninitialized.
2618 */
2619 if (!tty_port_initialized(tport))
2620 ret = port->ops->poll_init(port);
2621 }
2622
2623 if (!ret && options) {
2624 uart_parse_options(options, &baud, &parity, &bits, &flow);
2625 console_list_lock();
2626 ret = uart_set_options(port, NULL, baud, parity, bits, flow);
2627 console_list_unlock();
2628 }
2629out:
2630 mutex_unlock(&tport->mutex);
2631 return ret;
2632}
2633
2634static int uart_poll_get_char(struct tty_driver *driver, int line)
2635{
2636 struct uart_driver *drv = driver->driver_state;
2637 struct uart_state *state = drv->state + line;
2638 struct uart_port *port;
2639 int ret = -1;
2640
2641 port = uart_port_ref(state);
2642 if (port) {
2643 ret = port->ops->poll_get_char(port);
2644 uart_port_deref(port);
2645 }
2646
2647 return ret;
2648}
2649
2650static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2651{
2652 struct uart_driver *drv = driver->driver_state;
2653 struct uart_state *state = drv->state + line;
2654 struct uart_port *port;
2655
2656 port = uart_port_ref(state);
2657 if (!port)
2658 return;
2659
2660 if (ch == '\n')
2661 port->ops->poll_put_char(port, '\r');
2662 port->ops->poll_put_char(port, ch);
2663 uart_port_deref(port);
2664}
2665#endif
2666
2667static const struct tty_operations uart_ops = {
2668 .install = uart_install,
2669 .open = uart_open,
2670 .close = uart_close,
2671 .write = uart_write,
2672 .put_char = uart_put_char,
2673 .flush_chars = uart_flush_chars,
2674 .write_room = uart_write_room,
2675 .chars_in_buffer= uart_chars_in_buffer,
2676 .flush_buffer = uart_flush_buffer,
2677 .ioctl = uart_ioctl,
2678 .throttle = uart_throttle,
2679 .unthrottle = uart_unthrottle,
2680 .send_xchar = uart_send_xchar,
2681 .set_termios = uart_set_termios,
2682 .set_ldisc = uart_set_ldisc,
2683 .stop = uart_stop,
2684 .start = uart_start,
2685 .hangup = uart_hangup,
2686 .break_ctl = uart_break_ctl,
2687 .wait_until_sent= uart_wait_until_sent,
2688#ifdef CONFIG_PROC_FS
2689 .proc_show = uart_proc_show,
2690#endif
2691 .tiocmget = uart_tiocmget,
2692 .tiocmset = uart_tiocmset,
2693 .set_serial = uart_set_info_user,
2694 .get_serial = uart_get_info_user,
2695 .get_icount = uart_get_icount,
2696#ifdef CONFIG_CONSOLE_POLL
2697 .poll_init = uart_poll_init,
2698 .poll_get_char = uart_poll_get_char,
2699 .poll_put_char = uart_poll_put_char,
2700#endif
2701};
2702
2703static const struct tty_port_operations uart_port_ops = {
2704 .carrier_raised = uart_carrier_raised,
2705 .dtr_rts = uart_dtr_rts,
2706 .activate = uart_port_activate,
2707 .shutdown = uart_tty_port_shutdown,
2708};
2709
2710/**
2711 * uart_register_driver - register a driver with the uart core layer
2712 * @drv: low level driver structure
2713 *
2714 * Register a uart driver with the core driver. We in turn register with the
2715 * tty layer, and initialise the core driver per-port state.
2716 *
2717 * We have a proc file in /proc/tty/driver which is named after the normal
2718 * driver.
2719 *
2720 * @drv->port should be %NULL, and the per-port structures should be registered
2721 * using uart_add_one_port() after this call has succeeded.
2722 *
2723 * Locking: none, Interrupts: enabled
2724 */
2725int uart_register_driver(struct uart_driver *drv)
2726{
2727 struct tty_driver *normal;
2728 int i, retval = -ENOMEM;
2729
2730 BUG_ON(drv->state);
2731
2732 /*
2733 * Maybe we should be using a slab cache for this, especially if
2734 * we have a large number of ports to handle.
2735 */
2736 drv->state = kcalloc(drv->nr, sizeof(struct uart_state), GFP_KERNEL);
2737 if (!drv->state)
2738 goto out;
2739
2740 normal = tty_alloc_driver(drv->nr, TTY_DRIVER_REAL_RAW |
2741 TTY_DRIVER_DYNAMIC_DEV);
2742 if (IS_ERR(normal)) {
2743 retval = PTR_ERR(normal);
2744 goto out_kfree;
2745 }
2746
2747 drv->tty_driver = normal;
2748
2749 normal->driver_name = drv->driver_name;
2750 normal->name = drv->dev_name;
2751 normal->major = drv->major;
2752 normal->minor_start = drv->minor;
2753 normal->type = TTY_DRIVER_TYPE_SERIAL;
2754 normal->subtype = SERIAL_TYPE_NORMAL;
2755 normal->init_termios = tty_std_termios;
2756 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2757 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2758 normal->driver_state = drv;
2759 tty_set_operations(normal, &uart_ops);
2760
2761 /*
2762 * Initialise the UART state(s).
2763 */
2764 for (i = 0; i < drv->nr; i++) {
2765 struct uart_state *state = drv->state + i;
2766 struct tty_port *port = &state->port;
2767
2768 tty_port_init(port);
2769 port->ops = &uart_port_ops;
2770 }
2771
2772 retval = tty_register_driver(normal);
2773 if (retval >= 0)
2774 return retval;
2775
2776 for (i = 0; i < drv->nr; i++)
2777 tty_port_destroy(&drv->state[i].port);
2778 tty_driver_kref_put(normal);
2779out_kfree:
2780 kfree(drv->state);
2781out:
2782 return retval;
2783}
2784EXPORT_SYMBOL(uart_register_driver);
2785
2786/**
2787 * uart_unregister_driver - remove a driver from the uart core layer
2788 * @drv: low level driver structure
2789 *
2790 * Remove all references to a driver from the core driver. The low level
2791 * driver must have removed all its ports via the uart_remove_one_port() if it
2792 * registered them with uart_add_one_port(). (I.e. @drv->port is %NULL.)
2793 *
2794 * Locking: none, Interrupts: enabled
2795 */
2796void uart_unregister_driver(struct uart_driver *drv)
2797{
2798 struct tty_driver *p = drv->tty_driver;
2799 unsigned int i;
2800
2801 tty_unregister_driver(p);
2802 tty_driver_kref_put(p);
2803 for (i = 0; i < drv->nr; i++)
2804 tty_port_destroy(&drv->state[i].port);
2805 kfree(drv->state);
2806 drv->state = NULL;
2807 drv->tty_driver = NULL;
2808}
2809EXPORT_SYMBOL(uart_unregister_driver);
2810
2811struct tty_driver *uart_console_device(struct console *co, int *index)
2812{
2813 struct uart_driver *p = co->data;
2814 *index = co->index;
2815 return p->tty_driver;
2816}
2817EXPORT_SYMBOL_GPL(uart_console_device);
2818
2819static ssize_t uartclk_show(struct device *dev,
2820 struct device_attribute *attr, char *buf)
2821{
2822 struct serial_struct tmp;
2823 struct tty_port *port = dev_get_drvdata(dev);
2824
2825 uart_get_info(port, &tmp);
2826 return sprintf(buf, "%d\n", tmp.baud_base * 16);
2827}
2828
2829static ssize_t type_show(struct device *dev,
2830 struct device_attribute *attr, char *buf)
2831{
2832 struct serial_struct tmp;
2833 struct tty_port *port = dev_get_drvdata(dev);
2834
2835 uart_get_info(port, &tmp);
2836 return sprintf(buf, "%d\n", tmp.type);
2837}
2838
2839static ssize_t line_show(struct device *dev,
2840 struct device_attribute *attr, char *buf)
2841{
2842 struct serial_struct tmp;
2843 struct tty_port *port = dev_get_drvdata(dev);
2844
2845 uart_get_info(port, &tmp);
2846 return sprintf(buf, "%d\n", tmp.line);
2847}
2848
2849static ssize_t port_show(struct device *dev,
2850 struct device_attribute *attr, char *buf)
2851{
2852 struct serial_struct tmp;
2853 struct tty_port *port = dev_get_drvdata(dev);
2854 unsigned long ioaddr;
2855
2856 uart_get_info(port, &tmp);
2857 ioaddr = tmp.port;
2858 if (HIGH_BITS_OFFSET)
2859 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2860 return sprintf(buf, "0x%lX\n", ioaddr);
2861}
2862
2863static ssize_t irq_show(struct device *dev,
2864 struct device_attribute *attr, char *buf)
2865{
2866 struct serial_struct tmp;
2867 struct tty_port *port = dev_get_drvdata(dev);
2868
2869 uart_get_info(port, &tmp);
2870 return sprintf(buf, "%d\n", tmp.irq);
2871}
2872
2873static ssize_t flags_show(struct device *dev,
2874 struct device_attribute *attr, char *buf)
2875{
2876 struct serial_struct tmp;
2877 struct tty_port *port = dev_get_drvdata(dev);
2878
2879 uart_get_info(port, &tmp);
2880 return sprintf(buf, "0x%X\n", tmp.flags);
2881}
2882
2883static ssize_t xmit_fifo_size_show(struct device *dev,
2884 struct device_attribute *attr, char *buf)
2885{
2886 struct serial_struct tmp;
2887 struct tty_port *port = dev_get_drvdata(dev);
2888
2889 uart_get_info(port, &tmp);
2890 return sprintf(buf, "%d\n", tmp.xmit_fifo_size);
2891}
2892
2893static ssize_t close_delay_show(struct device *dev,
2894 struct device_attribute *attr, char *buf)
2895{
2896 struct serial_struct tmp;
2897 struct tty_port *port = dev_get_drvdata(dev);
2898
2899 uart_get_info(port, &tmp);
2900 return sprintf(buf, "%d\n", tmp.close_delay);
2901}
2902
2903static ssize_t closing_wait_show(struct device *dev,
2904 struct device_attribute *attr, char *buf)
2905{
2906 struct serial_struct tmp;
2907 struct tty_port *port = dev_get_drvdata(dev);
2908
2909 uart_get_info(port, &tmp);
2910 return sprintf(buf, "%d\n", tmp.closing_wait);
2911}
2912
2913static ssize_t custom_divisor_show(struct device *dev,
2914 struct device_attribute *attr, char *buf)
2915{
2916 struct serial_struct tmp;
2917 struct tty_port *port = dev_get_drvdata(dev);
2918
2919 uart_get_info(port, &tmp);
2920 return sprintf(buf, "%d\n", tmp.custom_divisor);
2921}
2922
2923static ssize_t io_type_show(struct device *dev,
2924 struct device_attribute *attr, char *buf)
2925{
2926 struct serial_struct tmp;
2927 struct tty_port *port = dev_get_drvdata(dev);
2928
2929 uart_get_info(port, &tmp);
2930 return sprintf(buf, "%d\n", tmp.io_type);
2931}
2932
2933static ssize_t iomem_base_show(struct device *dev,
2934 struct device_attribute *attr, char *buf)
2935{
2936 struct serial_struct tmp;
2937 struct tty_port *port = dev_get_drvdata(dev);
2938
2939 uart_get_info(port, &tmp);
2940 return sprintf(buf, "0x%lX\n", (unsigned long)tmp.iomem_base);
2941}
2942
2943static ssize_t iomem_reg_shift_show(struct device *dev,
2944 struct device_attribute *attr, char *buf)
2945{
2946 struct serial_struct tmp;
2947 struct tty_port *port = dev_get_drvdata(dev);
2948
2949 uart_get_info(port, &tmp);
2950 return sprintf(buf, "%d\n", tmp.iomem_reg_shift);
2951}
2952
2953static ssize_t console_show(struct device *dev,
2954 struct device_attribute *attr, char *buf)
2955{
2956 struct tty_port *port = dev_get_drvdata(dev);
2957 struct uart_state *state = container_of(port, struct uart_state, port);
2958 struct uart_port *uport;
2959 bool console = false;
2960
2961 mutex_lock(&port->mutex);
2962 uport = uart_port_check(state);
2963 if (uport)
2964 console = uart_console_registered(uport);
2965 mutex_unlock(&port->mutex);
2966
2967 return sprintf(buf, "%c\n", console ? 'Y' : 'N');
2968}
2969
2970static ssize_t console_store(struct device *dev,
2971 struct device_attribute *attr, const char *buf, size_t count)
2972{
2973 struct tty_port *port = dev_get_drvdata(dev);
2974 struct uart_state *state = container_of(port, struct uart_state, port);
2975 struct uart_port *uport;
2976 bool oldconsole, newconsole;
2977 int ret;
2978
2979 ret = kstrtobool(buf, &newconsole);
2980 if (ret)
2981 return ret;
2982
2983 mutex_lock(&port->mutex);
2984 uport = uart_port_check(state);
2985 if (uport) {
2986 oldconsole = uart_console_registered(uport);
2987 if (oldconsole && !newconsole) {
2988 ret = unregister_console(uport->cons);
2989 } else if (!oldconsole && newconsole) {
2990 if (uart_console(uport)) {
2991 uport->console_reinit = 1;
2992 register_console(uport->cons);
2993 } else {
2994 ret = -ENOENT;
2995 }
2996 }
2997 } else {
2998 ret = -ENXIO;
2999 }
3000 mutex_unlock(&port->mutex);
3001
3002 return ret < 0 ? ret : count;
3003}
3004
3005static DEVICE_ATTR_RO(uartclk);
3006static DEVICE_ATTR_RO(type);
3007static DEVICE_ATTR_RO(line);
3008static DEVICE_ATTR_RO(port);
3009static DEVICE_ATTR_RO(irq);
3010static DEVICE_ATTR_RO(flags);
3011static DEVICE_ATTR_RO(xmit_fifo_size);
3012static DEVICE_ATTR_RO(close_delay);
3013static DEVICE_ATTR_RO(closing_wait);
3014static DEVICE_ATTR_RO(custom_divisor);
3015static DEVICE_ATTR_RO(io_type);
3016static DEVICE_ATTR_RO(iomem_base);
3017static DEVICE_ATTR_RO(iomem_reg_shift);
3018static DEVICE_ATTR_RW(console);
3019
3020static struct attribute *tty_dev_attrs[] = {
3021 &dev_attr_uartclk.attr,
3022 &dev_attr_type.attr,
3023 &dev_attr_line.attr,
3024 &dev_attr_port.attr,
3025 &dev_attr_irq.attr,
3026 &dev_attr_flags.attr,
3027 &dev_attr_xmit_fifo_size.attr,
3028 &dev_attr_close_delay.attr,
3029 &dev_attr_closing_wait.attr,
3030 &dev_attr_custom_divisor.attr,
3031 &dev_attr_io_type.attr,
3032 &dev_attr_iomem_base.attr,
3033 &dev_attr_iomem_reg_shift.attr,
3034 &dev_attr_console.attr,
3035 NULL
3036};
3037
3038static const struct attribute_group tty_dev_attr_group = {
3039 .attrs = tty_dev_attrs,
3040};
3041
3042/**
3043 * uart_add_one_port - attach a driver-defined port structure
3044 * @drv: pointer to the uart low level driver structure for this port
3045 * @uport: uart port structure to use for this port.
3046 *
3047 * Context: task context, might sleep
3048 *
3049 * This allows the driver @drv to register its own uart_port structure with the
3050 * core driver. The main purpose is to allow the low level uart drivers to
3051 * expand uart_port, rather than having yet more levels of structures.
3052 */
3053int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
3054{
3055 struct uart_state *state;
3056 struct tty_port *port;
3057 int ret = 0;
3058 struct device *tty_dev;
3059 int num_groups;
3060
3061 if (uport->line >= drv->nr)
3062 return -EINVAL;
3063
3064 state = drv->state + uport->line;
3065 port = &state->port;
3066
3067 mutex_lock(&port_mutex);
3068 mutex_lock(&port->mutex);
3069 if (state->uart_port) {
3070 ret = -EINVAL;
3071 goto out;
3072 }
3073
3074 /* Link the port to the driver state table and vice versa */
3075 atomic_set(&state->refcount, 1);
3076 init_waitqueue_head(&state->remove_wait);
3077 state->uart_port = uport;
3078 uport->state = state;
3079
3080 state->pm_state = UART_PM_STATE_UNDEFINED;
3081 uport->cons = drv->cons;
3082 uport->minor = drv->tty_driver->minor_start + uport->line;
3083 uport->name = kasprintf(GFP_KERNEL, "%s%d", drv->dev_name,
3084 drv->tty_driver->name_base + uport->line);
3085 if (!uport->name) {
3086 ret = -ENOMEM;
3087 goto out;
3088 }
3089
3090 /*
3091 * If this port is in use as a console then the spinlock is already
3092 * initialised.
3093 */
3094 if (!uart_console_registered(uport))
3095 uart_port_spin_lock_init(uport);
3096
3097 if (uport->cons && uport->dev)
3098 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
3099
3100 tty_port_link_device(port, drv->tty_driver, uport->line);
3101 uart_configure_port(drv, state, uport);
3102
3103 port->console = uart_console(uport);
3104
3105 num_groups = 2;
3106 if (uport->attr_group)
3107 num_groups++;
3108
3109 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
3110 GFP_KERNEL);
3111 if (!uport->tty_groups) {
3112 ret = -ENOMEM;
3113 goto out;
3114 }
3115 uport->tty_groups[0] = &tty_dev_attr_group;
3116 if (uport->attr_group)
3117 uport->tty_groups[1] = uport->attr_group;
3118
3119 /*
3120 * Register the port whether it's detected or not. This allows
3121 * setserial to be used to alter this port's parameters.
3122 */
3123 tty_dev = tty_port_register_device_attr_serdev(port, drv->tty_driver,
3124 uport->line, uport->dev, port, uport->tty_groups);
3125 if (!IS_ERR(tty_dev)) {
3126 device_set_wakeup_capable(tty_dev, 1);
3127 } else {
3128 dev_err(uport->dev, "Cannot register tty device on line %d\n",
3129 uport->line);
3130 }
3131
3132 /*
3133 * Ensure UPF_DEAD is not set.
3134 */
3135 uport->flags &= ~UPF_DEAD;
3136
3137 out:
3138 mutex_unlock(&port->mutex);
3139 mutex_unlock(&port_mutex);
3140
3141 return ret;
3142}
3143EXPORT_SYMBOL(uart_add_one_port);
3144
3145/**
3146 * uart_remove_one_port - detach a driver defined port structure
3147 * @drv: pointer to the uart low level driver structure for this port
3148 * @uport: uart port structure for this port
3149 *
3150 * Context: task context, might sleep
3151 *
3152 * This unhooks (and hangs up) the specified port structure from the core
3153 * driver. No further calls will be made to the low-level code for this port.
3154 */
3155int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
3156{
3157 struct uart_state *state = drv->state + uport->line;
3158 struct tty_port *port = &state->port;
3159 struct uart_port *uart_port;
3160 struct tty_struct *tty;
3161 int ret = 0;
3162
3163 mutex_lock(&port_mutex);
3164
3165 /*
3166 * Mark the port "dead" - this prevents any opens from
3167 * succeeding while we shut down the port.
3168 */
3169 mutex_lock(&port->mutex);
3170 uart_port = uart_port_check(state);
3171 if (uart_port != uport)
3172 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
3173 uart_port, uport);
3174
3175 if (!uart_port) {
3176 mutex_unlock(&port->mutex);
3177 ret = -EINVAL;
3178 goto out;
3179 }
3180 uport->flags |= UPF_DEAD;
3181 mutex_unlock(&port->mutex);
3182
3183 /*
3184 * Remove the devices from the tty layer
3185 */
3186 tty_port_unregister_device(port, drv->tty_driver, uport->line);
3187
3188 tty = tty_port_tty_get(port);
3189 if (tty) {
3190 tty_vhangup(port->tty);
3191 tty_kref_put(tty);
3192 }
3193
3194 /*
3195 * If the port is used as a console, unregister it
3196 */
3197 if (uart_console(uport))
3198 unregister_console(uport->cons);
3199
3200 /*
3201 * Free the port IO and memory resources, if any.
3202 */
3203 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
3204 uport->ops->release_port(uport);
3205 kfree(uport->tty_groups);
3206 kfree(uport->name);
3207
3208 /*
3209 * Indicate that there isn't a port here anymore.
3210 */
3211 uport->type = PORT_UNKNOWN;
3212
3213 mutex_lock(&port->mutex);
3214 WARN_ON(atomic_dec_return(&state->refcount) < 0);
3215 wait_event(state->remove_wait, !atomic_read(&state->refcount));
3216 state->uart_port = NULL;
3217 mutex_unlock(&port->mutex);
3218out:
3219 mutex_unlock(&port_mutex);
3220
3221 return ret;
3222}
3223EXPORT_SYMBOL(uart_remove_one_port);
3224
3225/**
3226 * uart_match_port - are the two ports equivalent?
3227 * @port1: first port
3228 * @port2: second port
3229 *
3230 * This utility function can be used to determine whether two uart_port
3231 * structures describe the same port.
3232 */
3233bool uart_match_port(const struct uart_port *port1,
3234 const struct uart_port *port2)
3235{
3236 if (port1->iotype != port2->iotype)
3237 return false;
3238
3239 switch (port1->iotype) {
3240 case UPIO_PORT:
3241 return port1->iobase == port2->iobase;
3242 case UPIO_HUB6:
3243 return port1->iobase == port2->iobase &&
3244 port1->hub6 == port2->hub6;
3245 case UPIO_MEM:
3246 case UPIO_MEM16:
3247 case UPIO_MEM32:
3248 case UPIO_MEM32BE:
3249 case UPIO_AU:
3250 case UPIO_TSI:
3251 return port1->mapbase == port2->mapbase;
3252 }
3253
3254 return false;
3255}
3256EXPORT_SYMBOL(uart_match_port);
3257
3258/**
3259 * uart_handle_dcd_change - handle a change of carrier detect state
3260 * @uport: uart_port structure for the open port
3261 * @status: new carrier detect status, nonzero if active
3262 *
3263 * Caller must hold uport->lock.
3264 */
3265void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
3266{
3267 struct tty_port *port = &uport->state->port;
3268 struct tty_struct *tty = port->tty;
3269 struct tty_ldisc *ld;
3270
3271 lockdep_assert_held_once(&uport->lock);
3272
3273 if (tty) {
3274 ld = tty_ldisc_ref(tty);
3275 if (ld) {
3276 if (ld->ops->dcd_change)
3277 ld->ops->dcd_change(tty, status);
3278 tty_ldisc_deref(ld);
3279 }
3280 }
3281
3282 uport->icount.dcd++;
3283
3284 if (uart_dcd_enabled(uport)) {
3285 if (status)
3286 wake_up_interruptible(&port->open_wait);
3287 else if (tty)
3288 tty_hangup(tty);
3289 }
3290}
3291EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
3292
3293/**
3294 * uart_handle_cts_change - handle a change of clear-to-send state
3295 * @uport: uart_port structure for the open port
3296 * @status: new clear to send status, nonzero if active
3297 *
3298 * Caller must hold uport->lock.
3299 */
3300void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
3301{
3302 lockdep_assert_held_once(&uport->lock);
3303
3304 uport->icount.cts++;
3305
3306 if (uart_softcts_mode(uport)) {
3307 if (uport->hw_stopped) {
3308 if (status) {
3309 uport->hw_stopped = 0;
3310 uport->ops->start_tx(uport);
3311 uart_write_wakeup(uport);
3312 }
3313 } else {
3314 if (!status) {
3315 uport->hw_stopped = 1;
3316 uport->ops->stop_tx(uport);
3317 }
3318 }
3319
3320 }
3321}
3322EXPORT_SYMBOL_GPL(uart_handle_cts_change);
3323
3324/**
3325 * uart_insert_char - push a char to the uart layer
3326 *
3327 * User is responsible to call tty_flip_buffer_push when they are done with
3328 * insertion.
3329 *
3330 * @port: corresponding port
3331 * @status: state of the serial port RX buffer (LSR for 8250)
3332 * @overrun: mask of overrun bits in @status
3333 * @ch: character to push
3334 * @flag: flag for the character (see TTY_NORMAL and friends)
3335 */
3336void uart_insert_char(struct uart_port *port, unsigned int status,
3337 unsigned int overrun, unsigned int ch, unsigned int flag)
3338{
3339 struct tty_port *tport = &port->state->port;
3340
3341 if ((status & port->ignore_status_mask & ~overrun) == 0)
3342 if (tty_insert_flip_char(tport, ch, flag) == 0)
3343 ++port->icount.buf_overrun;
3344
3345 /*
3346 * Overrun is special. Since it's reported immediately,
3347 * it doesn't affect the current character.
3348 */
3349 if (status & ~port->ignore_status_mask & overrun)
3350 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
3351 ++port->icount.buf_overrun;
3352}
3353EXPORT_SYMBOL_GPL(uart_insert_char);
3354
3355#ifdef CONFIG_MAGIC_SYSRQ_SERIAL
3356static const char sysrq_toggle_seq[] = CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE;
3357
3358static void uart_sysrq_on(struct work_struct *w)
3359{
3360 int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq);
3361
3362 sysrq_toggle_support(1);
3363 pr_info("SysRq is enabled by magic sequence '%*pE' on serial\n",
3364 sysrq_toggle_seq_len, sysrq_toggle_seq);
3365}
3366static DECLARE_WORK(sysrq_enable_work, uart_sysrq_on);
3367
3368/**
3369 * uart_try_toggle_sysrq - Enables SysRq from serial line
3370 * @port: uart_port structure where char(s) after BREAK met
3371 * @ch: new character in the sequence after received BREAK
3372 *
3373 * Enables magic SysRq when the required sequence is met on port
3374 * (see CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE).
3375 *
3376 * Returns: %false if @ch is out of enabling sequence and should be
3377 * handled some other way, %true if @ch was consumed.
3378 */
3379bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch)
3380{
3381 int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq);
3382
3383 if (!sysrq_toggle_seq_len)
3384 return false;
3385
3386 BUILD_BUG_ON(ARRAY_SIZE(sysrq_toggle_seq) >= U8_MAX);
3387 if (sysrq_toggle_seq[port->sysrq_seq] != ch) {
3388 port->sysrq_seq = 0;
3389 return false;
3390 }
3391
3392 if (++port->sysrq_seq < sysrq_toggle_seq_len) {
3393 port->sysrq = jiffies + SYSRQ_TIMEOUT;
3394 return true;
3395 }
3396
3397 schedule_work(&sysrq_enable_work);
3398
3399 port->sysrq = 0;
3400 return true;
3401}
3402EXPORT_SYMBOL_GPL(uart_try_toggle_sysrq);
3403#endif
3404
3405/**
3406 * uart_get_rs485_mode() - retrieve rs485 properties for given uart
3407 * @port: uart device's target port
3408 *
3409 * This function implements the device tree binding described in
3410 * Documentation/devicetree/bindings/serial/rs485.txt.
3411 */
3412int uart_get_rs485_mode(struct uart_port *port)
3413{
3414 struct serial_rs485 *rs485conf = &port->rs485;
3415 struct device *dev = port->dev;
3416 u32 rs485_delay[2];
3417 int ret;
3418
3419 ret = device_property_read_u32_array(dev, "rs485-rts-delay",
3420 rs485_delay, 2);
3421 if (!ret) {
3422 rs485conf->delay_rts_before_send = rs485_delay[0];
3423 rs485conf->delay_rts_after_send = rs485_delay[1];
3424 } else {
3425 rs485conf->delay_rts_before_send = 0;
3426 rs485conf->delay_rts_after_send = 0;
3427 }
3428
3429 uart_sanitize_serial_rs485_delays(port, rs485conf);
3430
3431 /*
3432 * Clear full-duplex and enabled flags, set RTS polarity to active high
3433 * to get to a defined state with the following properties:
3434 */
3435 rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED |
3436 SER_RS485_TERMINATE_BUS |
3437 SER_RS485_RTS_AFTER_SEND);
3438 rs485conf->flags |= SER_RS485_RTS_ON_SEND;
3439
3440 if (device_property_read_bool(dev, "rs485-rx-during-tx"))
3441 rs485conf->flags |= SER_RS485_RX_DURING_TX;
3442
3443 if (device_property_read_bool(dev, "linux,rs485-enabled-at-boot-time"))
3444 rs485conf->flags |= SER_RS485_ENABLED;
3445
3446 if (device_property_read_bool(dev, "rs485-rts-active-low")) {
3447 rs485conf->flags &= ~SER_RS485_RTS_ON_SEND;
3448 rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
3449 }
3450
3451 /*
3452 * Disabling termination by default is the safe choice: Else if many
3453 * bus participants enable it, no communication is possible at all.
3454 * Works fine for short cables and users may enable for longer cables.
3455 */
3456 port->rs485_term_gpio = devm_gpiod_get_optional(dev, "rs485-term",
3457 GPIOD_OUT_LOW);
3458 if (IS_ERR(port->rs485_term_gpio)) {
3459 ret = PTR_ERR(port->rs485_term_gpio);
3460 port->rs485_term_gpio = NULL;
3461 return dev_err_probe(dev, ret, "Cannot get rs485-term-gpios\n");
3462 }
3463 if (port->rs485_term_gpio)
3464 port->rs485_supported.flags |= SER_RS485_TERMINATE_BUS;
3465
3466 return 0;
3467}
3468EXPORT_SYMBOL_GPL(uart_get_rs485_mode);
3469
3470/* Compile-time assertions for serial_rs485 layout */
3471static_assert(offsetof(struct serial_rs485, padding) ==
3472 (offsetof(struct serial_rs485, delay_rts_after_send) + sizeof(__u32)));
3473static_assert(offsetof(struct serial_rs485, padding1) ==
3474 offsetof(struct serial_rs485, padding[1]));
3475static_assert((offsetof(struct serial_rs485, padding[4]) + sizeof(__u32)) ==
3476 sizeof(struct serial_rs485));
3477
3478MODULE_DESCRIPTION("Serial driver core");
3479MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Driver core for serial ports
4 *
5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 *
7 * Copyright 1999 ARM Limited
8 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
9 */
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>
17#include <linux/gpio/consumer.h>
18#include <linux/of.h>
19#include <linux/proc_fs.h>
20#include <linux/seq_file.h>
21#include <linux/device.h>
22#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
23#include <linux/serial_core.h>
24#include <linux/sysrq.h>
25#include <linux/delay.h>
26#include <linux/mutex.h>
27#include <linux/security.h>
28
29#include <linux/irq.h>
30#include <linux/uaccess.h>
31
32/*
33 * This is used to lock changes in serial line configuration.
34 */
35static DEFINE_MUTEX(port_mutex);
36
37/*
38 * lockdep: port->lock is initialized in two places, but we
39 * want only one lock-class:
40 */
41static struct lock_class_key port_lock_key;
42
43#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
44
45static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
46 struct ktermios *old_termios);
47static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
48static void uart_change_pm(struct uart_state *state,
49 enum uart_pm_state pm_state);
50
51static void uart_port_shutdown(struct tty_port *port);
52
53static int uart_dcd_enabled(struct uart_port *uport)
54{
55 return !!(uport->status & UPSTAT_DCD_ENABLE);
56}
57
58static inline struct uart_port *uart_port_ref(struct uart_state *state)
59{
60 if (atomic_add_unless(&state->refcount, 1, 0))
61 return state->uart_port;
62 return NULL;
63}
64
65static inline void uart_port_deref(struct uart_port *uport)
66{
67 if (atomic_dec_and_test(&uport->state->refcount))
68 wake_up(&uport->state->remove_wait);
69}
70
71#define uart_port_lock(state, flags) \
72 ({ \
73 struct uart_port *__uport = uart_port_ref(state); \
74 if (__uport) \
75 spin_lock_irqsave(&__uport->lock, flags); \
76 __uport; \
77 })
78
79#define uart_port_unlock(uport, flags) \
80 ({ \
81 struct uart_port *__uport = uport; \
82 if (__uport) { \
83 spin_unlock_irqrestore(&__uport->lock, flags); \
84 uart_port_deref(__uport); \
85 } \
86 })
87
88static inline struct uart_port *uart_port_check(struct uart_state *state)
89{
90 lockdep_assert_held(&state->port.mutex);
91 return state->uart_port;
92}
93
94/*
95 * This routine is used by the interrupt handler to schedule processing in
96 * the software interrupt portion of the driver.
97 */
98void uart_write_wakeup(struct uart_port *port)
99{
100 struct uart_state *state = port->state;
101 /*
102 * This means you called this function _after_ the port was
103 * closed. No cookie for you.
104 */
105 BUG_ON(!state);
106 tty_port_tty_wakeup(&state->port);
107}
108
109static void uart_stop(struct tty_struct *tty)
110{
111 struct uart_state *state = tty->driver_data;
112 struct uart_port *port;
113 unsigned long flags;
114
115 port = uart_port_lock(state, flags);
116 if (port)
117 port->ops->stop_tx(port);
118 uart_port_unlock(port, flags);
119}
120
121static void __uart_start(struct tty_struct *tty)
122{
123 struct uart_state *state = tty->driver_data;
124 struct uart_port *port = state->uart_port;
125
126 if (port && !uart_tx_stopped(port))
127 port->ops->start_tx(port);
128}
129
130static void uart_start(struct tty_struct *tty)
131{
132 struct uart_state *state = tty->driver_data;
133 struct uart_port *port;
134 unsigned long flags;
135
136 port = uart_port_lock(state, flags);
137 __uart_start(tty);
138 uart_port_unlock(port, flags);
139}
140
141static void
142uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
143{
144 unsigned long flags;
145 unsigned int old;
146
147 spin_lock_irqsave(&port->lock, flags);
148 old = port->mctrl;
149 port->mctrl = (old & ~clear) | set;
150 if (old != port->mctrl)
151 port->ops->set_mctrl(port, port->mctrl);
152 spin_unlock_irqrestore(&port->lock, flags);
153}
154
155#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
156#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
157
158static void uart_port_dtr_rts(struct uart_port *uport, int raise)
159{
160 int rs485_on = uport->rs485_config &&
161 (uport->rs485.flags & SER_RS485_ENABLED);
162 int RTS_after_send = !!(uport->rs485.flags & SER_RS485_RTS_AFTER_SEND);
163
164 if (raise) {
165 if (rs485_on && !RTS_after_send) {
166 uart_set_mctrl(uport, TIOCM_DTR);
167 uart_clear_mctrl(uport, TIOCM_RTS);
168 } else {
169 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
170 }
171 } else {
172 unsigned int clear = TIOCM_DTR;
173
174 clear |= (!rs485_on || !RTS_after_send) ? TIOCM_RTS : 0;
175 uart_clear_mctrl(uport, clear);
176 }
177}
178
179/*
180 * Startup the port. This will be called once per open. All calls
181 * will be serialised by the per-port mutex.
182 */
183static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
184 int init_hw)
185{
186 struct uart_port *uport = uart_port_check(state);
187 unsigned long flags;
188 unsigned long page;
189 int retval = 0;
190
191 if (uport->type == PORT_UNKNOWN)
192 return 1;
193
194 /*
195 * Make sure the device is in D0 state.
196 */
197 uart_change_pm(state, UART_PM_STATE_ON);
198
199 /*
200 * Initialise and allocate the transmit and temporary
201 * buffer.
202 */
203 page = get_zeroed_page(GFP_KERNEL);
204 if (!page)
205 return -ENOMEM;
206
207 uart_port_lock(state, flags);
208 if (!state->xmit.buf) {
209 state->xmit.buf = (unsigned char *) page;
210 uart_circ_clear(&state->xmit);
211 uart_port_unlock(uport, flags);
212 } else {
213 uart_port_unlock(uport, flags);
214 /*
215 * Do not free() the page under the port lock, see
216 * uart_shutdown().
217 */
218 free_page(page);
219 }
220
221 retval = uport->ops->startup(uport);
222 if (retval == 0) {
223 if (uart_console(uport) && uport->cons->cflag) {
224 tty->termios.c_cflag = uport->cons->cflag;
225 uport->cons->cflag = 0;
226 }
227 /*
228 * Initialise the hardware port settings.
229 */
230 uart_change_speed(tty, state, NULL);
231
232 /*
233 * Setup the RTS and DTR signals once the
234 * port is open and ready to respond.
235 */
236 if (init_hw && C_BAUD(tty))
237 uart_port_dtr_rts(uport, 1);
238 }
239
240 /*
241 * This is to allow setserial on this port. People may want to set
242 * port/irq/type and then reconfigure the port properly if it failed
243 * now.
244 */
245 if (retval && capable(CAP_SYS_ADMIN))
246 return 1;
247
248 return retval;
249}
250
251static int uart_startup(struct tty_struct *tty, struct uart_state *state,
252 int init_hw)
253{
254 struct tty_port *port = &state->port;
255 int retval;
256
257 if (tty_port_initialized(port))
258 return 0;
259
260 retval = uart_port_startup(tty, state, init_hw);
261 if (retval)
262 set_bit(TTY_IO_ERROR, &tty->flags);
263
264 return retval;
265}
266
267/*
268 * This routine will shutdown a serial port; interrupts are disabled, and
269 * DTR is dropped if the hangup on close termio flag is on. Calls to
270 * uart_shutdown are serialised by the per-port semaphore.
271 *
272 * uport == NULL if uart_port has already been removed
273 */
274static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
275{
276 struct uart_port *uport = uart_port_check(state);
277 struct tty_port *port = &state->port;
278 unsigned long flags;
279 char *xmit_buf = NULL;
280
281 /*
282 * Set the TTY IO error marker
283 */
284 if (tty)
285 set_bit(TTY_IO_ERROR, &tty->flags);
286
287 if (tty_port_initialized(port)) {
288 tty_port_set_initialized(port, 0);
289
290 /*
291 * Turn off DTR and RTS early.
292 */
293 if (uport && uart_console(uport) && tty)
294 uport->cons->cflag = tty->termios.c_cflag;
295
296 if (!tty || C_HUPCL(tty))
297 uart_port_dtr_rts(uport, 0);
298
299 uart_port_shutdown(port);
300 }
301
302 /*
303 * It's possible for shutdown to be called after suspend if we get
304 * a DCD drop (hangup) at just the right time. Clear suspended bit so
305 * we don't try to resume a port that has been shutdown.
306 */
307 tty_port_set_suspended(port, 0);
308
309 /*
310 * Do not free() the transmit buffer page under the port lock since
311 * this can create various circular locking scenarios. For instance,
312 * console driver may need to allocate/free a debug object, which
313 * can endup in printk() recursion.
314 */
315 uart_port_lock(state, flags);
316 xmit_buf = state->xmit.buf;
317 state->xmit.buf = NULL;
318 uart_port_unlock(uport, flags);
319
320 if (xmit_buf)
321 free_page((unsigned long)xmit_buf);
322}
323
324/**
325 * uart_update_timeout - update per-port FIFO timeout.
326 * @port: uart_port structure describing the port
327 * @cflag: termios cflag value
328 * @baud: speed of the port
329 *
330 * Set the port FIFO timeout value. The @cflag value should
331 * reflect the actual hardware settings.
332 */
333void
334uart_update_timeout(struct uart_port *port, unsigned int cflag,
335 unsigned int baud)
336{
337 unsigned int size;
338
339 size = tty_get_frame_size(cflag) * port->fifosize;
340
341 /*
342 * Figure the timeout to send the above number of bits.
343 * Add .02 seconds of slop
344 */
345 port->timeout = (HZ * size) / baud + HZ/50;
346}
347
348EXPORT_SYMBOL(uart_update_timeout);
349
350/**
351 * uart_get_baud_rate - return baud rate for a particular port
352 * @port: uart_port structure describing the port in question.
353 * @termios: desired termios settings.
354 * @old: old termios (or NULL)
355 * @min: minimum acceptable baud rate
356 * @max: maximum acceptable baud rate
357 *
358 * Decode the termios structure into a numeric baud rate,
359 * taking account of the magic 38400 baud rate (with spd_*
360 * flags), and mapping the %B0 rate to 9600 baud.
361 *
362 * If the new baud rate is invalid, try the old termios setting.
363 * If it's still invalid, we try 9600 baud.
364 *
365 * Update the @termios structure to reflect the baud rate
366 * we're actually going to be using. Don't do this for the case
367 * where B0 is requested ("hang up").
368 */
369unsigned int
370uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
371 struct ktermios *old, unsigned int min, unsigned int max)
372{
373 unsigned int try;
374 unsigned int baud;
375 unsigned int altbaud;
376 int hung_up = 0;
377 upf_t flags = port->flags & UPF_SPD_MASK;
378
379 switch (flags) {
380 case UPF_SPD_HI:
381 altbaud = 57600;
382 break;
383 case UPF_SPD_VHI:
384 altbaud = 115200;
385 break;
386 case UPF_SPD_SHI:
387 altbaud = 230400;
388 break;
389 case UPF_SPD_WARP:
390 altbaud = 460800;
391 break;
392 default:
393 altbaud = 38400;
394 break;
395 }
396
397 for (try = 0; try < 2; try++) {
398 baud = tty_termios_baud_rate(termios);
399
400 /*
401 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
402 * Die! Die! Die!
403 */
404 if (try == 0 && baud == 38400)
405 baud = altbaud;
406
407 /*
408 * Special case: B0 rate.
409 */
410 if (baud == 0) {
411 hung_up = 1;
412 baud = 9600;
413 }
414
415 if (baud >= min && baud <= max)
416 return baud;
417
418 /*
419 * Oops, the quotient was zero. Try again with
420 * the old baud rate if possible.
421 */
422 termios->c_cflag &= ~CBAUD;
423 if (old) {
424 baud = tty_termios_baud_rate(old);
425 if (!hung_up)
426 tty_termios_encode_baud_rate(termios,
427 baud, baud);
428 old = NULL;
429 continue;
430 }
431
432 /*
433 * As a last resort, if the range cannot be met then clip to
434 * the nearest chip supported rate.
435 */
436 if (!hung_up) {
437 if (baud <= min)
438 tty_termios_encode_baud_rate(termios,
439 min + 1, min + 1);
440 else
441 tty_termios_encode_baud_rate(termios,
442 max - 1, max - 1);
443 }
444 }
445 /* Should never happen */
446 WARN_ON(1);
447 return 0;
448}
449
450EXPORT_SYMBOL(uart_get_baud_rate);
451
452/**
453 * uart_get_divisor - return uart clock divisor
454 * @port: uart_port structure describing the port.
455 * @baud: desired baud rate
456 *
457 * Calculate the uart clock divisor for the port.
458 */
459unsigned int
460uart_get_divisor(struct uart_port *port, unsigned int baud)
461{
462 unsigned int quot;
463
464 /*
465 * Old custom speed handling.
466 */
467 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
468 quot = port->custom_divisor;
469 else
470 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
471
472 return quot;
473}
474
475EXPORT_SYMBOL(uart_get_divisor);
476
477/* Caller holds port mutex */
478static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
479 struct ktermios *old_termios)
480{
481 struct uart_port *uport = uart_port_check(state);
482 struct ktermios *termios;
483 int hw_stopped;
484
485 /*
486 * If we have no tty, termios, or the port does not exist,
487 * then we can't set the parameters for this port.
488 */
489 if (!tty || uport->type == PORT_UNKNOWN)
490 return;
491
492 termios = &tty->termios;
493 uport->ops->set_termios(uport, termios, old_termios);
494
495 /*
496 * Set modem status enables based on termios cflag
497 */
498 spin_lock_irq(&uport->lock);
499 if (termios->c_cflag & CRTSCTS)
500 uport->status |= UPSTAT_CTS_ENABLE;
501 else
502 uport->status &= ~UPSTAT_CTS_ENABLE;
503
504 if (termios->c_cflag & CLOCAL)
505 uport->status &= ~UPSTAT_DCD_ENABLE;
506 else
507 uport->status |= UPSTAT_DCD_ENABLE;
508
509 /* reset sw-assisted CTS flow control based on (possibly) new mode */
510 hw_stopped = uport->hw_stopped;
511 uport->hw_stopped = uart_softcts_mode(uport) &&
512 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
513 if (uport->hw_stopped) {
514 if (!hw_stopped)
515 uport->ops->stop_tx(uport);
516 } else {
517 if (hw_stopped)
518 __uart_start(tty);
519 }
520 spin_unlock_irq(&uport->lock);
521}
522
523static int uart_put_char(struct tty_struct *tty, unsigned char c)
524{
525 struct uart_state *state = tty->driver_data;
526 struct uart_port *port;
527 struct circ_buf *circ;
528 unsigned long flags;
529 int ret = 0;
530
531 circ = &state->xmit;
532 port = uart_port_lock(state, flags);
533 if (!circ->buf) {
534 uart_port_unlock(port, flags);
535 return 0;
536 }
537
538 if (port && uart_circ_chars_free(circ) != 0) {
539 circ->buf[circ->head] = c;
540 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
541 ret = 1;
542 }
543 uart_port_unlock(port, flags);
544 return ret;
545}
546
547static void uart_flush_chars(struct tty_struct *tty)
548{
549 uart_start(tty);
550}
551
552static int uart_write(struct tty_struct *tty,
553 const unsigned char *buf, int count)
554{
555 struct uart_state *state = tty->driver_data;
556 struct uart_port *port;
557 struct circ_buf *circ;
558 unsigned long flags;
559 int c, ret = 0;
560
561 /*
562 * This means you called this function _after_ the port was
563 * closed. No cookie for you.
564 */
565 if (!state) {
566 WARN_ON(1);
567 return -EL3HLT;
568 }
569
570 port = uart_port_lock(state, flags);
571 circ = &state->xmit;
572 if (!circ->buf) {
573 uart_port_unlock(port, flags);
574 return 0;
575 }
576
577 while (port) {
578 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
579 if (count < c)
580 c = count;
581 if (c <= 0)
582 break;
583 memcpy(circ->buf + circ->head, buf, c);
584 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
585 buf += c;
586 count -= c;
587 ret += c;
588 }
589
590 __uart_start(tty);
591 uart_port_unlock(port, flags);
592 return ret;
593}
594
595static unsigned int uart_write_room(struct tty_struct *tty)
596{
597 struct uart_state *state = tty->driver_data;
598 struct uart_port *port;
599 unsigned long flags;
600 unsigned int ret;
601
602 port = uart_port_lock(state, flags);
603 ret = uart_circ_chars_free(&state->xmit);
604 uart_port_unlock(port, flags);
605 return ret;
606}
607
608static unsigned int uart_chars_in_buffer(struct tty_struct *tty)
609{
610 struct uart_state *state = tty->driver_data;
611 struct uart_port *port;
612 unsigned long flags;
613 unsigned int ret;
614
615 port = uart_port_lock(state, flags);
616 ret = uart_circ_chars_pending(&state->xmit);
617 uart_port_unlock(port, flags);
618 return ret;
619}
620
621static void uart_flush_buffer(struct tty_struct *tty)
622{
623 struct uart_state *state = tty->driver_data;
624 struct uart_port *port;
625 unsigned long flags;
626
627 /*
628 * This means you called this function _after_ the port was
629 * closed. No cookie for you.
630 */
631 if (!state) {
632 WARN_ON(1);
633 return;
634 }
635
636 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
637
638 port = uart_port_lock(state, flags);
639 if (!port)
640 return;
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);
646}
647
648/*
649 * This function is used to send a high-priority XON/XOFF character to
650 * the device
651 */
652static void uart_send_xchar(struct tty_struct *tty, char ch)
653{
654 struct uart_state *state = tty->driver_data;
655 struct uart_port *port;
656 unsigned long flags;
657
658 port = uart_port_ref(state);
659 if (!port)
660 return;
661
662 if (port->ops->send_xchar)
663 port->ops->send_xchar(port, ch);
664 else {
665 spin_lock_irqsave(&port->lock, flags);
666 port->x_char = ch;
667 if (ch)
668 port->ops->start_tx(port);
669 spin_unlock_irqrestore(&port->lock, flags);
670 }
671 uart_port_deref(port);
672}
673
674static void uart_throttle(struct tty_struct *tty)
675{
676 struct uart_state *state = tty->driver_data;
677 upstat_t mask = UPSTAT_SYNC_FIFO;
678 struct uart_port *port;
679
680 port = uart_port_ref(state);
681 if (!port)
682 return;
683
684 if (I_IXOFF(tty))
685 mask |= UPSTAT_AUTOXOFF;
686 if (C_CRTSCTS(tty))
687 mask |= UPSTAT_AUTORTS;
688
689 if (port->status & mask) {
690 port->ops->throttle(port);
691 mask &= ~port->status;
692 }
693
694 if (mask & UPSTAT_AUTORTS)
695 uart_clear_mctrl(port, TIOCM_RTS);
696
697 if (mask & UPSTAT_AUTOXOFF)
698 uart_send_xchar(tty, STOP_CHAR(tty));
699
700 uart_port_deref(port);
701}
702
703static void uart_unthrottle(struct tty_struct *tty)
704{
705 struct uart_state *state = tty->driver_data;
706 upstat_t mask = UPSTAT_SYNC_FIFO;
707 struct uart_port *port;
708
709 port = uart_port_ref(state);
710 if (!port)
711 return;
712
713 if (I_IXOFF(tty))
714 mask |= UPSTAT_AUTOXOFF;
715 if (C_CRTSCTS(tty))
716 mask |= UPSTAT_AUTORTS;
717
718 if (port->status & mask) {
719 port->ops->unthrottle(port);
720 mask &= ~port->status;
721 }
722
723 if (mask & UPSTAT_AUTORTS)
724 uart_set_mctrl(port, TIOCM_RTS);
725
726 if (mask & UPSTAT_AUTOXOFF)
727 uart_send_xchar(tty, START_CHAR(tty));
728
729 uart_port_deref(port);
730}
731
732static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
733{
734 struct uart_state *state = container_of(port, struct uart_state, port);
735 struct uart_port *uport;
736 int ret = -ENODEV;
737
738 /*
739 * Ensure the state we copy is consistent and no hardware changes
740 * occur as we go
741 */
742 mutex_lock(&port->mutex);
743 uport = uart_port_check(state);
744 if (!uport)
745 goto out;
746
747 retinfo->type = uport->type;
748 retinfo->line = uport->line;
749 retinfo->port = uport->iobase;
750 if (HIGH_BITS_OFFSET)
751 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
752 retinfo->irq = uport->irq;
753 retinfo->flags = (__force int)uport->flags;
754 retinfo->xmit_fifo_size = uport->fifosize;
755 retinfo->baud_base = uport->uartclk / 16;
756 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
757 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
758 ASYNC_CLOSING_WAIT_NONE :
759 jiffies_to_msecs(port->closing_wait) / 10;
760 retinfo->custom_divisor = uport->custom_divisor;
761 retinfo->hub6 = uport->hub6;
762 retinfo->io_type = uport->iotype;
763 retinfo->iomem_reg_shift = uport->regshift;
764 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
765
766 ret = 0;
767out:
768 mutex_unlock(&port->mutex);
769 return ret;
770}
771
772static int uart_get_info_user(struct tty_struct *tty,
773 struct serial_struct *ss)
774{
775 struct uart_state *state = tty->driver_data;
776 struct tty_port *port = &state->port;
777
778 return uart_get_info(port, ss) < 0 ? -EIO : 0;
779}
780
781static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
782 struct uart_state *state,
783 struct serial_struct *new_info)
784{
785 struct uart_port *uport = uart_port_check(state);
786 unsigned long new_port;
787 unsigned int change_irq, change_port, closing_wait;
788 unsigned int old_custom_divisor, close_delay;
789 upf_t old_flags, new_flags;
790 int retval = 0;
791
792 if (!uport)
793 return -EIO;
794
795 new_port = new_info->port;
796 if (HIGH_BITS_OFFSET)
797 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
798
799 new_info->irq = irq_canonicalize(new_info->irq);
800 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
801 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
802 ASYNC_CLOSING_WAIT_NONE :
803 msecs_to_jiffies(new_info->closing_wait * 10);
804
805
806 change_irq = !(uport->flags & UPF_FIXED_PORT)
807 && new_info->irq != uport->irq;
808
809 /*
810 * Since changing the 'type' of the port changes its resource
811 * allocations, we should treat type changes the same as
812 * IO port changes.
813 */
814 change_port = !(uport->flags & UPF_FIXED_PORT)
815 && (new_port != uport->iobase ||
816 (unsigned long)new_info->iomem_base != uport->mapbase ||
817 new_info->hub6 != uport->hub6 ||
818 new_info->io_type != uport->iotype ||
819 new_info->iomem_reg_shift != uport->regshift ||
820 new_info->type != uport->type);
821
822 old_flags = uport->flags;
823 new_flags = (__force upf_t)new_info->flags;
824 old_custom_divisor = uport->custom_divisor;
825
826 if (!capable(CAP_SYS_ADMIN)) {
827 retval = -EPERM;
828 if (change_irq || change_port ||
829 (new_info->baud_base != uport->uartclk / 16) ||
830 (close_delay != port->close_delay) ||
831 (closing_wait != port->closing_wait) ||
832 (new_info->xmit_fifo_size &&
833 new_info->xmit_fifo_size != uport->fifosize) ||
834 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
835 goto exit;
836 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
837 (new_flags & UPF_USR_MASK));
838 uport->custom_divisor = new_info->custom_divisor;
839 goto check_and_exit;
840 }
841
842 if (change_irq || change_port) {
843 retval = security_locked_down(LOCKDOWN_TIOCSSERIAL);
844 if (retval)
845 goto exit;
846 }
847
848 /*
849 * Ask the low level driver to verify the settings.
850 */
851 if (uport->ops->verify_port)
852 retval = uport->ops->verify_port(uport, new_info);
853
854 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
855 (new_info->baud_base < 9600))
856 retval = -EINVAL;
857
858 if (retval)
859 goto exit;
860
861 if (change_port || change_irq) {
862 retval = -EBUSY;
863
864 /*
865 * Make sure that we are the sole user of this port.
866 */
867 if (tty_port_users(port) > 1)
868 goto exit;
869
870 /*
871 * We need to shutdown the serial port at the old
872 * port/type/irq combination.
873 */
874 uart_shutdown(tty, state);
875 }
876
877 if (change_port) {
878 unsigned long old_iobase, old_mapbase;
879 unsigned int old_type, old_iotype, old_hub6, old_shift;
880
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;
887
888 /*
889 * Free and release old regions
890 */
891 if (old_type != PORT_UNKNOWN && uport->ops->release_port)
892 uport->ops->release_port(uport);
893
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;
900
901 /*
902 * Claim and map the new regions
903 */
904 if (uport->type != PORT_UNKNOWN && uport->ops->request_port) {
905 retval = uport->ops->request_port(uport);
906 } else {
907 /* Always success - Jean II */
908 retval = 0;
909 }
910
911 /*
912 * If we fail to request resources for the
913 * new port, try to restore the old settings.
914 */
915 if (retval) {
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;
922
923 if (old_type != PORT_UNKNOWN) {
924 retval = uport->ops->request_port(uport);
925 /*
926 * If we failed to restore the old settings,
927 * we fail like this.
928 */
929 if (retval)
930 uport->type = PORT_UNKNOWN;
931
932 /*
933 * We failed anyway.
934 */
935 retval = -EBUSY;
936 }
937
938 /* Added to return the correct error -Ram Gupta */
939 goto exit;
940 }
941 }
942
943 if (change_irq)
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
955 check_and_exit:
956 retval = 0;
957 if (uport->type == PORT_UNKNOWN)
958 goto exit;
959 if (tty_port_initialized(port)) {
960 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
961 old_custom_divisor != uport->custom_divisor) {
962 /*
963 * If they're setting up a custom divisor or speed,
964 * instead of clearing it, then bitch about it.
965 */
966 if (uport->flags & UPF_SPD_MASK) {
967 dev_notice_ratelimited(uport->dev,
968 "%s sets custom speed on %s. This is deprecated.\n",
969 current->comm,
970 tty_name(port->tty));
971 }
972 uart_change_speed(tty, state, NULL);
973 }
974 } else {
975 retval = uart_startup(tty, state, 1);
976 if (retval == 0)
977 tty_port_set_initialized(port, true);
978 if (retval > 0)
979 retval = 0;
980 }
981 exit:
982 return retval;
983}
984
985static int uart_set_info_user(struct tty_struct *tty, struct serial_struct *ss)
986{
987 struct uart_state *state = tty->driver_data;
988 struct tty_port *port = &state->port;
989 int retval;
990
991 down_write(&tty->termios_rwsem);
992 /*
993 * This semaphore protects port->count. It is also
994 * very useful to prevent opens. Also, take the
995 * port configuration semaphore to make sure that a
996 * module insertion/removal doesn't change anything
997 * under us.
998 */
999 mutex_lock(&port->mutex);
1000 retval = uart_set_info(tty, port, state, ss);
1001 mutex_unlock(&port->mutex);
1002 up_write(&tty->termios_rwsem);
1003 return retval;
1004}
1005
1006/**
1007 * uart_get_lsr_info - get line status register info
1008 * @tty: tty associated with the UART
1009 * @state: UART being queried
1010 * @value: returned modem value
1011 */
1012static int uart_get_lsr_info(struct tty_struct *tty,
1013 struct uart_state *state, unsigned int __user *value)
1014{
1015 struct uart_port *uport = uart_port_check(state);
1016 unsigned int result;
1017
1018 result = uport->ops->tx_empty(uport);
1019
1020 /*
1021 * If we're about to load something into the transmit
1022 * register, we'll pretend the transmitter isn't empty to
1023 * avoid a race condition (depending on when the transmit
1024 * interrupt happens).
1025 */
1026 if (uport->x_char ||
1027 ((uart_circ_chars_pending(&state->xmit) > 0) &&
1028 !uart_tx_stopped(uport)))
1029 result &= ~TIOCSER_TEMT;
1030
1031 return put_user(result, value);
1032}
1033
1034static int uart_tiocmget(struct tty_struct *tty)
1035{
1036 struct uart_state *state = tty->driver_data;
1037 struct tty_port *port = &state->port;
1038 struct uart_port *uport;
1039 int result = -EIO;
1040
1041 mutex_lock(&port->mutex);
1042 uport = uart_port_check(state);
1043 if (!uport)
1044 goto out;
1045
1046 if (!tty_io_error(tty)) {
1047 result = uport->mctrl;
1048 spin_lock_irq(&uport->lock);
1049 result |= uport->ops->get_mctrl(uport);
1050 spin_unlock_irq(&uport->lock);
1051 }
1052out:
1053 mutex_unlock(&port->mutex);
1054 return result;
1055}
1056
1057static int
1058uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
1059{
1060 struct uart_state *state = tty->driver_data;
1061 struct tty_port *port = &state->port;
1062 struct uart_port *uport;
1063 int ret = -EIO;
1064
1065 mutex_lock(&port->mutex);
1066 uport = uart_port_check(state);
1067 if (!uport)
1068 goto out;
1069
1070 if (!tty_io_error(tty)) {
1071 uart_update_mctrl(uport, set, clear);
1072 ret = 0;
1073 }
1074out:
1075 mutex_unlock(&port->mutex);
1076 return ret;
1077}
1078
1079static int uart_break_ctl(struct tty_struct *tty, int break_state)
1080{
1081 struct uart_state *state = tty->driver_data;
1082 struct tty_port *port = &state->port;
1083 struct uart_port *uport;
1084 int ret = -EIO;
1085
1086 mutex_lock(&port->mutex);
1087 uport = uart_port_check(state);
1088 if (!uport)
1089 goto out;
1090
1091 if (uport->type != PORT_UNKNOWN && uport->ops->break_ctl)
1092 uport->ops->break_ctl(uport, break_state);
1093 ret = 0;
1094out:
1095 mutex_unlock(&port->mutex);
1096 return ret;
1097}
1098
1099static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state)
1100{
1101 struct tty_port *port = &state->port;
1102 struct uart_port *uport;
1103 int flags, ret;
1104
1105 if (!capable(CAP_SYS_ADMIN))
1106 return -EPERM;
1107
1108 /*
1109 * Take the per-port semaphore. This prevents count from
1110 * changing, and hence any extra opens of the port while
1111 * we're auto-configuring.
1112 */
1113 if (mutex_lock_interruptible(&port->mutex))
1114 return -ERESTARTSYS;
1115
1116 uport = uart_port_check(state);
1117 if (!uport) {
1118 ret = -EIO;
1119 goto out;
1120 }
1121
1122 ret = -EBUSY;
1123 if (tty_port_users(port) == 1) {
1124 uart_shutdown(tty, state);
1125
1126 /*
1127 * If we already have a port type configured,
1128 * we must release its resources.
1129 */
1130 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
1131 uport->ops->release_port(uport);
1132
1133 flags = UART_CONFIG_TYPE;
1134 if (uport->flags & UPF_AUTO_IRQ)
1135 flags |= UART_CONFIG_IRQ;
1136
1137 /*
1138 * This will claim the ports resources if
1139 * a port is found.
1140 */
1141 uport->ops->config_port(uport, flags);
1142
1143 ret = uart_startup(tty, state, 1);
1144 if (ret == 0)
1145 tty_port_set_initialized(port, true);
1146 if (ret > 0)
1147 ret = 0;
1148 }
1149out:
1150 mutex_unlock(&port->mutex);
1151 return ret;
1152}
1153
1154static void uart_enable_ms(struct uart_port *uport)
1155{
1156 /*
1157 * Force modem status interrupts on
1158 */
1159 if (uport->ops->enable_ms)
1160 uport->ops->enable_ms(uport);
1161}
1162
1163/*
1164 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1165 * - mask passed in arg for lines of interest
1166 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1167 * Caller should use TIOCGICOUNT to see which one it was
1168 *
1169 * FIXME: This wants extracting into a common all driver implementation
1170 * of TIOCMWAIT using tty_port.
1171 */
1172static int uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1173{
1174 struct uart_port *uport;
1175 struct tty_port *port = &state->port;
1176 DECLARE_WAITQUEUE(wait, current);
1177 struct uart_icount cprev, cnow;
1178 int ret;
1179
1180 /*
1181 * note the counters on entry
1182 */
1183 uport = uart_port_ref(state);
1184 if (!uport)
1185 return -EIO;
1186 spin_lock_irq(&uport->lock);
1187 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1188 uart_enable_ms(uport);
1189 spin_unlock_irq(&uport->lock);
1190
1191 add_wait_queue(&port->delta_msr_wait, &wait);
1192 for (;;) {
1193 spin_lock_irq(&uport->lock);
1194 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1195 spin_unlock_irq(&uport->lock);
1196
1197 set_current_state(TASK_INTERRUPTIBLE);
1198
1199 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1200 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1201 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1202 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1203 ret = 0;
1204 break;
1205 }
1206
1207 schedule();
1208
1209 /* see if a signal did it */
1210 if (signal_pending(current)) {
1211 ret = -ERESTARTSYS;
1212 break;
1213 }
1214
1215 cprev = cnow;
1216 }
1217 __set_current_state(TASK_RUNNING);
1218 remove_wait_queue(&port->delta_msr_wait, &wait);
1219 uart_port_deref(uport);
1220
1221 return ret;
1222}
1223
1224/*
1225 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1226 * Return: write counters to the user passed counter struct
1227 * NB: both 1->0 and 0->1 transitions are counted except for
1228 * RI where only 0->1 is counted.
1229 */
1230static int uart_get_icount(struct tty_struct *tty,
1231 struct serial_icounter_struct *icount)
1232{
1233 struct uart_state *state = tty->driver_data;
1234 struct uart_icount cnow;
1235 struct uart_port *uport;
1236
1237 uport = uart_port_ref(state);
1238 if (!uport)
1239 return -EIO;
1240 spin_lock_irq(&uport->lock);
1241 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1242 spin_unlock_irq(&uport->lock);
1243 uart_port_deref(uport);
1244
1245 icount->cts = cnow.cts;
1246 icount->dsr = cnow.dsr;
1247 icount->rng = cnow.rng;
1248 icount->dcd = cnow.dcd;
1249 icount->rx = cnow.rx;
1250 icount->tx = cnow.tx;
1251 icount->frame = cnow.frame;
1252 icount->overrun = cnow.overrun;
1253 icount->parity = cnow.parity;
1254 icount->brk = cnow.brk;
1255 icount->buf_overrun = cnow.buf_overrun;
1256
1257 return 0;
1258}
1259
1260static int uart_get_rs485_config(struct uart_port *port,
1261 struct serial_rs485 __user *rs485)
1262{
1263 unsigned long flags;
1264 struct serial_rs485 aux;
1265
1266 spin_lock_irqsave(&port->lock, flags);
1267 aux = port->rs485;
1268 spin_unlock_irqrestore(&port->lock, flags);
1269
1270 if (copy_to_user(rs485, &aux, sizeof(aux)))
1271 return -EFAULT;
1272
1273 return 0;
1274}
1275
1276static int uart_set_rs485_config(struct uart_port *port,
1277 struct serial_rs485 __user *rs485_user)
1278{
1279 struct serial_rs485 rs485;
1280 int ret;
1281 unsigned long flags;
1282
1283 if (!port->rs485_config)
1284 return -ENOTTY;
1285
1286 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1287 return -EFAULT;
1288
1289 spin_lock_irqsave(&port->lock, flags);
1290 ret = port->rs485_config(port, &rs485);
1291 spin_unlock_irqrestore(&port->lock, flags);
1292 if (ret)
1293 return ret;
1294
1295 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1296 return -EFAULT;
1297
1298 return 0;
1299}
1300
1301static int uart_get_iso7816_config(struct uart_port *port,
1302 struct serial_iso7816 __user *iso7816)
1303{
1304 unsigned long flags;
1305 struct serial_iso7816 aux;
1306
1307 if (!port->iso7816_config)
1308 return -ENOTTY;
1309
1310 spin_lock_irqsave(&port->lock, flags);
1311 aux = port->iso7816;
1312 spin_unlock_irqrestore(&port->lock, flags);
1313
1314 if (copy_to_user(iso7816, &aux, sizeof(aux)))
1315 return -EFAULT;
1316
1317 return 0;
1318}
1319
1320static int uart_set_iso7816_config(struct uart_port *port,
1321 struct serial_iso7816 __user *iso7816_user)
1322{
1323 struct serial_iso7816 iso7816;
1324 int i, ret;
1325 unsigned long flags;
1326
1327 if (!port->iso7816_config)
1328 return -ENOTTY;
1329
1330 if (copy_from_user(&iso7816, iso7816_user, sizeof(*iso7816_user)))
1331 return -EFAULT;
1332
1333 /*
1334 * There are 5 words reserved for future use. Check that userspace
1335 * doesn't put stuff in there to prevent breakages in the future.
1336 */
1337 for (i = 0; i < 5; i++)
1338 if (iso7816.reserved[i])
1339 return -EINVAL;
1340
1341 spin_lock_irqsave(&port->lock, flags);
1342 ret = port->iso7816_config(port, &iso7816);
1343 spin_unlock_irqrestore(&port->lock, flags);
1344 if (ret)
1345 return ret;
1346
1347 if (copy_to_user(iso7816_user, &port->iso7816, sizeof(port->iso7816)))
1348 return -EFAULT;
1349
1350 return 0;
1351}
1352
1353/*
1354 * Called via sys_ioctl. We can use spin_lock_irq() here.
1355 */
1356static int
1357uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
1358{
1359 struct uart_state *state = tty->driver_data;
1360 struct tty_port *port = &state->port;
1361 struct uart_port *uport;
1362 void __user *uarg = (void __user *)arg;
1363 int ret = -ENOIOCTLCMD;
1364
1365
1366 /*
1367 * These ioctls don't rely on the hardware to be present.
1368 */
1369 switch (cmd) {
1370 case TIOCSERCONFIG:
1371 down_write(&tty->termios_rwsem);
1372 ret = uart_do_autoconfig(tty, state);
1373 up_write(&tty->termios_rwsem);
1374 break;
1375 }
1376
1377 if (ret != -ENOIOCTLCMD)
1378 goto out;
1379
1380 if (tty_io_error(tty)) {
1381 ret = -EIO;
1382 goto out;
1383 }
1384
1385 /*
1386 * The following should only be used when hardware is present.
1387 */
1388 switch (cmd) {
1389 case TIOCMIWAIT:
1390 ret = uart_wait_modem_status(state, arg);
1391 break;
1392 }
1393
1394 if (ret != -ENOIOCTLCMD)
1395 goto out;
1396
1397 mutex_lock(&port->mutex);
1398 uport = uart_port_check(state);
1399
1400 if (!uport || tty_io_error(tty)) {
1401 ret = -EIO;
1402 goto out_up;
1403 }
1404
1405 /*
1406 * All these rely on hardware being present and need to be
1407 * protected against the tty being hung up.
1408 */
1409
1410 switch (cmd) {
1411 case TIOCSERGETLSR: /* Get line status register */
1412 ret = uart_get_lsr_info(tty, state, uarg);
1413 break;
1414
1415 case TIOCGRS485:
1416 ret = uart_get_rs485_config(uport, uarg);
1417 break;
1418
1419 case TIOCSRS485:
1420 ret = uart_set_rs485_config(uport, uarg);
1421 break;
1422
1423 case TIOCSISO7816:
1424 ret = uart_set_iso7816_config(state->uart_port, uarg);
1425 break;
1426
1427 case TIOCGISO7816:
1428 ret = uart_get_iso7816_config(state->uart_port, uarg);
1429 break;
1430 default:
1431 if (uport->ops->ioctl)
1432 ret = uport->ops->ioctl(uport, cmd, arg);
1433 break;
1434 }
1435out_up:
1436 mutex_unlock(&port->mutex);
1437out:
1438 return ret;
1439}
1440
1441static void uart_set_ldisc(struct tty_struct *tty)
1442{
1443 struct uart_state *state = tty->driver_data;
1444 struct uart_port *uport;
1445 struct tty_port *port = &state->port;
1446
1447 if (!tty_port_initialized(port))
1448 return;
1449
1450 mutex_lock(&state->port.mutex);
1451 uport = uart_port_check(state);
1452 if (uport && uport->ops->set_ldisc)
1453 uport->ops->set_ldisc(uport, &tty->termios);
1454 mutex_unlock(&state->port.mutex);
1455}
1456
1457static void uart_set_termios(struct tty_struct *tty,
1458 struct ktermios *old_termios)
1459{
1460 struct uart_state *state = tty->driver_data;
1461 struct uart_port *uport;
1462 unsigned int cflag = tty->termios.c_cflag;
1463 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1464 bool sw_changed = false;
1465
1466 mutex_lock(&state->port.mutex);
1467 uport = uart_port_check(state);
1468 if (!uport)
1469 goto out;
1470
1471 /*
1472 * Drivers doing software flow control also need to know
1473 * about changes to these input settings.
1474 */
1475 if (uport->flags & UPF_SOFT_FLOW) {
1476 iflag_mask |= IXANY|IXON|IXOFF;
1477 sw_changed =
1478 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1479 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1480 }
1481
1482 /*
1483 * These are the bits that are used to setup various
1484 * flags in the low level driver. We can ignore the Bfoo
1485 * bits in c_cflag; c_[io]speed will always be set
1486 * appropriately by set_termios() in tty_ioctl.c
1487 */
1488 if ((cflag ^ old_termios->c_cflag) == 0 &&
1489 tty->termios.c_ospeed == old_termios->c_ospeed &&
1490 tty->termios.c_ispeed == old_termios->c_ispeed &&
1491 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1492 !sw_changed) {
1493 goto out;
1494 }
1495
1496 uart_change_speed(tty, state, old_termios);
1497 /* reload cflag from termios; port driver may have overridden flags */
1498 cflag = tty->termios.c_cflag;
1499
1500 /* Handle transition to B0 status */
1501 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1502 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1503 /* Handle transition away from B0 status */
1504 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1505 unsigned int mask = TIOCM_DTR;
1506
1507 if (!(cflag & CRTSCTS) || !tty_throttled(tty))
1508 mask |= TIOCM_RTS;
1509 uart_set_mctrl(uport, mask);
1510 }
1511out:
1512 mutex_unlock(&state->port.mutex);
1513}
1514
1515/*
1516 * Calls to uart_close() are serialised via the tty_lock in
1517 * drivers/tty/tty_io.c:tty_release()
1518 * drivers/tty/tty_io.c:do_tty_hangup()
1519 */
1520static void uart_close(struct tty_struct *tty, struct file *filp)
1521{
1522 struct uart_state *state = tty->driver_data;
1523
1524 if (!state) {
1525 struct uart_driver *drv = tty->driver->driver_state;
1526 struct tty_port *port;
1527
1528 state = drv->state + tty->index;
1529 port = &state->port;
1530 spin_lock_irq(&port->lock);
1531 --port->count;
1532 spin_unlock_irq(&port->lock);
1533 return;
1534 }
1535
1536 pr_debug("uart_close(%d) called\n", tty->index);
1537
1538 tty_port_close(tty->port, tty, filp);
1539}
1540
1541static void uart_tty_port_shutdown(struct tty_port *port)
1542{
1543 struct uart_state *state = container_of(port, struct uart_state, port);
1544 struct uart_port *uport = uart_port_check(state);
1545
1546 /*
1547 * At this point, we stop accepting input. To do this, we
1548 * disable the receive line status interrupts.
1549 */
1550 if (WARN(!uport, "detached port still initialized!\n"))
1551 return;
1552
1553 spin_lock_irq(&uport->lock);
1554 uport->ops->stop_rx(uport);
1555 spin_unlock_irq(&uport->lock);
1556
1557 uart_port_shutdown(port);
1558
1559 /*
1560 * It's possible for shutdown to be called after suspend if we get
1561 * a DCD drop (hangup) at just the right time. Clear suspended bit so
1562 * we don't try to resume a port that has been shutdown.
1563 */
1564 tty_port_set_suspended(port, 0);
1565
1566 uart_change_pm(state, UART_PM_STATE_OFF);
1567
1568}
1569
1570static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1571{
1572 struct uart_state *state = tty->driver_data;
1573 struct uart_port *port;
1574 unsigned long char_time, expire;
1575
1576 port = uart_port_ref(state);
1577 if (!port)
1578 return;
1579
1580 if (port->type == PORT_UNKNOWN || port->fifosize == 0) {
1581 uart_port_deref(port);
1582 return;
1583 }
1584
1585 /*
1586 * Set the check interval to be 1/5 of the estimated time to
1587 * send a single character, and make it at least 1. The check
1588 * interval should also be less than the timeout.
1589 *
1590 * Note: we have to use pretty tight timings here to satisfy
1591 * the NIST-PCTS.
1592 */
1593 char_time = (port->timeout - HZ/50) / port->fifosize;
1594 char_time = char_time / 5;
1595 if (char_time == 0)
1596 char_time = 1;
1597 if (timeout && timeout < char_time)
1598 char_time = timeout;
1599
1600 /*
1601 * If the transmitter hasn't cleared in twice the approximate
1602 * amount of time to send the entire FIFO, it probably won't
1603 * ever clear. This assumes the UART isn't doing flow
1604 * control, which is currently the case. Hence, if it ever
1605 * takes longer than port->timeout, this is probably due to a
1606 * UART bug of some kind. So, we clamp the timeout parameter at
1607 * 2*port->timeout.
1608 */
1609 if (timeout == 0 || timeout > 2 * port->timeout)
1610 timeout = 2 * port->timeout;
1611
1612 expire = jiffies + timeout;
1613
1614 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1615 port->line, jiffies, expire);
1616
1617 /*
1618 * Check whether the transmitter is empty every 'char_time'.
1619 * 'timeout' / 'expire' give us the maximum amount of time
1620 * we wait.
1621 */
1622 while (!port->ops->tx_empty(port)) {
1623 msleep_interruptible(jiffies_to_msecs(char_time));
1624 if (signal_pending(current))
1625 break;
1626 if (time_after(jiffies, expire))
1627 break;
1628 }
1629 uart_port_deref(port);
1630}
1631
1632/*
1633 * Calls to uart_hangup() are serialised by the tty_lock in
1634 * drivers/tty/tty_io.c:do_tty_hangup()
1635 * This runs from a workqueue and can sleep for a _short_ time only.
1636 */
1637static void uart_hangup(struct tty_struct *tty)
1638{
1639 struct uart_state *state = tty->driver_data;
1640 struct tty_port *port = &state->port;
1641 struct uart_port *uport;
1642 unsigned long flags;
1643
1644 pr_debug("uart_hangup(%d)\n", tty->index);
1645
1646 mutex_lock(&port->mutex);
1647 uport = uart_port_check(state);
1648 WARN(!uport, "hangup of detached port!\n");
1649
1650 if (tty_port_active(port)) {
1651 uart_flush_buffer(tty);
1652 uart_shutdown(tty, state);
1653 spin_lock_irqsave(&port->lock, flags);
1654 port->count = 0;
1655 spin_unlock_irqrestore(&port->lock, flags);
1656 tty_port_set_active(port, 0);
1657 tty_port_tty_set(port, NULL);
1658 if (uport && !uart_console(uport))
1659 uart_change_pm(state, UART_PM_STATE_OFF);
1660 wake_up_interruptible(&port->open_wait);
1661 wake_up_interruptible(&port->delta_msr_wait);
1662 }
1663 mutex_unlock(&port->mutex);
1664}
1665
1666/* uport == NULL if uart_port has already been removed */
1667static void uart_port_shutdown(struct tty_port *port)
1668{
1669 struct uart_state *state = container_of(port, struct uart_state, port);
1670 struct uart_port *uport = uart_port_check(state);
1671
1672 /*
1673 * clear delta_msr_wait queue to avoid mem leaks: we may free
1674 * the irq here so the queue might never be woken up. Note
1675 * that we won't end up waiting on delta_msr_wait again since
1676 * any outstanding file descriptors should be pointing at
1677 * hung_up_tty_fops now.
1678 */
1679 wake_up_interruptible(&port->delta_msr_wait);
1680
1681 /*
1682 * Free the IRQ and disable the port.
1683 */
1684 if (uport)
1685 uport->ops->shutdown(uport);
1686
1687 /*
1688 * Ensure that the IRQ handler isn't running on another CPU.
1689 */
1690 if (uport)
1691 synchronize_irq(uport->irq);
1692}
1693
1694static int uart_carrier_raised(struct tty_port *port)
1695{
1696 struct uart_state *state = container_of(port, struct uart_state, port);
1697 struct uart_port *uport;
1698 int mctrl;
1699
1700 uport = uart_port_ref(state);
1701 /*
1702 * Should never observe uport == NULL since checks for hangup should
1703 * abort the tty_port_block_til_ready() loop before checking for carrier
1704 * raised -- but report carrier raised if it does anyway so open will
1705 * continue and not sleep
1706 */
1707 if (WARN_ON(!uport))
1708 return 1;
1709 spin_lock_irq(&uport->lock);
1710 uart_enable_ms(uport);
1711 mctrl = uport->ops->get_mctrl(uport);
1712 spin_unlock_irq(&uport->lock);
1713 uart_port_deref(uport);
1714 if (mctrl & TIOCM_CAR)
1715 return 1;
1716 return 0;
1717}
1718
1719static void uart_dtr_rts(struct tty_port *port, int raise)
1720{
1721 struct uart_state *state = container_of(port, struct uart_state, port);
1722 struct uart_port *uport;
1723
1724 uport = uart_port_ref(state);
1725 if (!uport)
1726 return;
1727 uart_port_dtr_rts(uport, raise);
1728 uart_port_deref(uport);
1729}
1730
1731static int uart_install(struct tty_driver *driver, struct tty_struct *tty)
1732{
1733 struct uart_driver *drv = driver->driver_state;
1734 struct uart_state *state = drv->state + tty->index;
1735
1736 tty->driver_data = state;
1737
1738 return tty_standard_install(driver, tty);
1739}
1740
1741/*
1742 * Calls to uart_open are serialised by the tty_lock in
1743 * drivers/tty/tty_io.c:tty_open()
1744 * Note that if this fails, then uart_close() _will_ be called.
1745 *
1746 * In time, we want to scrap the "opening nonpresent ports"
1747 * behaviour and implement an alternative way for setserial
1748 * to set base addresses/ports/types. This will allow us to
1749 * get rid of a certain amount of extra tests.
1750 */
1751static int uart_open(struct tty_struct *tty, struct file *filp)
1752{
1753 struct uart_state *state = tty->driver_data;
1754 int retval;
1755
1756 retval = tty_port_open(&state->port, tty, filp);
1757 if (retval > 0)
1758 retval = 0;
1759
1760 return retval;
1761}
1762
1763static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1764{
1765 struct uart_state *state = container_of(port, struct uart_state, port);
1766 struct uart_port *uport;
1767 int ret;
1768
1769 uport = uart_port_check(state);
1770 if (!uport || uport->flags & UPF_DEAD)
1771 return -ENXIO;
1772
1773 /*
1774 * Start up the serial port.
1775 */
1776 ret = uart_startup(tty, state, 0);
1777 if (ret > 0)
1778 tty_port_set_active(port, 1);
1779
1780 return ret;
1781}
1782
1783static const char *uart_type(struct uart_port *port)
1784{
1785 const char *str = NULL;
1786
1787 if (port->ops->type)
1788 str = port->ops->type(port);
1789
1790 if (!str)
1791 str = "unknown";
1792
1793 return str;
1794}
1795
1796#ifdef CONFIG_PROC_FS
1797
1798static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1799{
1800 struct uart_state *state = drv->state + i;
1801 struct tty_port *port = &state->port;
1802 enum uart_pm_state pm_state;
1803 struct uart_port *uport;
1804 char stat_buf[32];
1805 unsigned int status;
1806 int mmio;
1807
1808 mutex_lock(&port->mutex);
1809 uport = uart_port_check(state);
1810 if (!uport)
1811 goto out;
1812
1813 mmio = uport->iotype >= UPIO_MEM;
1814 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1815 uport->line, uart_type(uport),
1816 mmio ? "mmio:0x" : "port:",
1817 mmio ? (unsigned long long)uport->mapbase
1818 : (unsigned long long)uport->iobase,
1819 uport->irq);
1820
1821 if (uport->type == PORT_UNKNOWN) {
1822 seq_putc(m, '\n');
1823 goto out;
1824 }
1825
1826 if (capable(CAP_SYS_ADMIN)) {
1827 pm_state = state->pm_state;
1828 if (pm_state != UART_PM_STATE_ON)
1829 uart_change_pm(state, UART_PM_STATE_ON);
1830 spin_lock_irq(&uport->lock);
1831 status = uport->ops->get_mctrl(uport);
1832 spin_unlock_irq(&uport->lock);
1833 if (pm_state != UART_PM_STATE_ON)
1834 uart_change_pm(state, pm_state);
1835
1836 seq_printf(m, " tx:%d rx:%d",
1837 uport->icount.tx, uport->icount.rx);
1838 if (uport->icount.frame)
1839 seq_printf(m, " fe:%d", uport->icount.frame);
1840 if (uport->icount.parity)
1841 seq_printf(m, " pe:%d", uport->icount.parity);
1842 if (uport->icount.brk)
1843 seq_printf(m, " brk:%d", uport->icount.brk);
1844 if (uport->icount.overrun)
1845 seq_printf(m, " oe:%d", uport->icount.overrun);
1846 if (uport->icount.buf_overrun)
1847 seq_printf(m, " bo:%d", uport->icount.buf_overrun);
1848
1849#define INFOBIT(bit, str) \
1850 if (uport->mctrl & (bit)) \
1851 strncat(stat_buf, (str), sizeof(stat_buf) - \
1852 strlen(stat_buf) - 2)
1853#define STATBIT(bit, str) \
1854 if (status & (bit)) \
1855 strncat(stat_buf, (str), sizeof(stat_buf) - \
1856 strlen(stat_buf) - 2)
1857
1858 stat_buf[0] = '\0';
1859 stat_buf[1] = '\0';
1860 INFOBIT(TIOCM_RTS, "|RTS");
1861 STATBIT(TIOCM_CTS, "|CTS");
1862 INFOBIT(TIOCM_DTR, "|DTR");
1863 STATBIT(TIOCM_DSR, "|DSR");
1864 STATBIT(TIOCM_CAR, "|CD");
1865 STATBIT(TIOCM_RNG, "|RI");
1866 if (stat_buf[0])
1867 stat_buf[0] = ' ';
1868
1869 seq_puts(m, stat_buf);
1870 }
1871 seq_putc(m, '\n');
1872#undef STATBIT
1873#undef INFOBIT
1874out:
1875 mutex_unlock(&port->mutex);
1876}
1877
1878static int uart_proc_show(struct seq_file *m, void *v)
1879{
1880 struct tty_driver *ttydrv = m->private;
1881 struct uart_driver *drv = ttydrv->driver_state;
1882 int i;
1883
1884 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
1885 for (i = 0; i < drv->nr; i++)
1886 uart_line_info(m, drv, i);
1887 return 0;
1888}
1889#endif
1890
1891static inline bool uart_console_enabled(struct uart_port *port)
1892{
1893 return uart_console(port) && (port->cons->flags & CON_ENABLED);
1894}
1895
1896static void uart_port_spin_lock_init(struct uart_port *port)
1897{
1898 spin_lock_init(&port->lock);
1899 lockdep_set_class(&port->lock, &port_lock_key);
1900}
1901
1902#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1903/**
1904 * uart_console_write - write a console message to a serial port
1905 * @port: the port to write the message
1906 * @s: array of characters
1907 * @count: number of characters in string to write
1908 * @putchar: function to write character to port
1909 */
1910void uart_console_write(struct uart_port *port, const char *s,
1911 unsigned int count,
1912 void (*putchar)(struct uart_port *, int))
1913{
1914 unsigned int i;
1915
1916 for (i = 0; i < count; i++, s++) {
1917 if (*s == '\n')
1918 putchar(port, '\r');
1919 putchar(port, *s);
1920 }
1921}
1922EXPORT_SYMBOL_GPL(uart_console_write);
1923
1924/*
1925 * Check whether an invalid uart number has been specified, and
1926 * if so, search for the first available port that does have
1927 * console support.
1928 */
1929struct uart_port * __init
1930uart_get_console(struct uart_port *ports, int nr, struct console *co)
1931{
1932 int idx = co->index;
1933
1934 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1935 ports[idx].membase == NULL))
1936 for (idx = 0; idx < nr; idx++)
1937 if (ports[idx].iobase != 0 ||
1938 ports[idx].membase != NULL)
1939 break;
1940
1941 co->index = idx;
1942
1943 return ports + idx;
1944}
1945
1946/**
1947 * uart_parse_earlycon - Parse earlycon options
1948 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1949 * @iotype: ptr for decoded iotype (out)
1950 * @addr: ptr for decoded mapbase/iobase (out)
1951 * @options: ptr for <options> field; NULL if not present (out)
1952 *
1953 * Decodes earlycon kernel command line parameters of the form
1954 * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1955 * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1956 *
1957 * The optional form
1958 *
1959 * earlycon=<name>,0x<addr>,<options>
1960 * console=<name>,0x<addr>,<options>
1961 *
1962 * is also accepted; the returned @iotype will be UPIO_MEM.
1963 *
1964 * Returns 0 on success or -EINVAL on failure
1965 */
1966int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
1967 char **options)
1968{
1969 if (strncmp(p, "mmio,", 5) == 0) {
1970 *iotype = UPIO_MEM;
1971 p += 5;
1972 } else if (strncmp(p, "mmio16,", 7) == 0) {
1973 *iotype = UPIO_MEM16;
1974 p += 7;
1975 } else if (strncmp(p, "mmio32,", 7) == 0) {
1976 *iotype = UPIO_MEM32;
1977 p += 7;
1978 } else if (strncmp(p, "mmio32be,", 9) == 0) {
1979 *iotype = UPIO_MEM32BE;
1980 p += 9;
1981 } else if (strncmp(p, "mmio32native,", 13) == 0) {
1982 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
1983 UPIO_MEM32BE : UPIO_MEM32;
1984 p += 13;
1985 } else if (strncmp(p, "io,", 3) == 0) {
1986 *iotype = UPIO_PORT;
1987 p += 3;
1988 } else if (strncmp(p, "0x", 2) == 0) {
1989 *iotype = UPIO_MEM;
1990 } else {
1991 return -EINVAL;
1992 }
1993
1994 /*
1995 * Before you replace it with kstrtoull(), think about options separator
1996 * (',') it will not tolerate
1997 */
1998 *addr = simple_strtoull(p, NULL, 0);
1999 p = strchr(p, ',');
2000 if (p)
2001 p++;
2002
2003 *options = p;
2004 return 0;
2005}
2006EXPORT_SYMBOL_GPL(uart_parse_earlycon);
2007
2008/**
2009 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
2010 * @options: pointer to option string
2011 * @baud: pointer to an 'int' variable for the baud rate.
2012 * @parity: pointer to an 'int' variable for the parity.
2013 * @bits: pointer to an 'int' variable for the number of data bits.
2014 * @flow: pointer to an 'int' variable for the flow control character.
2015 *
2016 * uart_parse_options decodes a string containing the serial console
2017 * options. The format of the string is <baud><parity><bits><flow>,
2018 * eg: 115200n8r
2019 */
2020void
2021uart_parse_options(const char *options, int *baud, int *parity,
2022 int *bits, int *flow)
2023{
2024 const char *s = options;
2025
2026 *baud = simple_strtoul(s, NULL, 10);
2027 while (*s >= '0' && *s <= '9')
2028 s++;
2029 if (*s)
2030 *parity = *s++;
2031 if (*s)
2032 *bits = *s++ - '0';
2033 if (*s)
2034 *flow = *s;
2035}
2036EXPORT_SYMBOL_GPL(uart_parse_options);
2037
2038/**
2039 * uart_set_options - setup the serial console parameters
2040 * @port: pointer to the serial ports uart_port structure
2041 * @co: console pointer
2042 * @baud: baud rate
2043 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
2044 * @bits: number of data bits
2045 * @flow: flow control character - 'r' (rts)
2046 */
2047int
2048uart_set_options(struct uart_port *port, struct console *co,
2049 int baud, int parity, int bits, int flow)
2050{
2051 struct ktermios termios;
2052 static struct ktermios dummy;
2053
2054 /*
2055 * Ensure that the serial-console lock is initialised early.
2056 *
2057 * Note that the console-enabled check is needed because of kgdboc,
2058 * which can end up calling uart_set_options() for an already enabled
2059 * console via tty_find_polling_driver() and uart_poll_init().
2060 */
2061 if (!uart_console_enabled(port) && !port->console_reinit)
2062 uart_port_spin_lock_init(port);
2063
2064 memset(&termios, 0, sizeof(struct ktermios));
2065
2066 termios.c_cflag |= CREAD | HUPCL | CLOCAL;
2067 tty_termios_encode_baud_rate(&termios, baud, baud);
2068
2069 if (bits == 7)
2070 termios.c_cflag |= CS7;
2071 else
2072 termios.c_cflag |= CS8;
2073
2074 switch (parity) {
2075 case 'o': case 'O':
2076 termios.c_cflag |= PARODD;
2077 fallthrough;
2078 case 'e': case 'E':
2079 termios.c_cflag |= PARENB;
2080 break;
2081 }
2082
2083 if (flow == 'r')
2084 termios.c_cflag |= CRTSCTS;
2085
2086 /*
2087 * some uarts on other side don't support no flow control.
2088 * So we set * DTR in host uart to make them happy
2089 */
2090 port->mctrl |= TIOCM_DTR;
2091
2092 port->ops->set_termios(port, &termios, &dummy);
2093 /*
2094 * Allow the setting of the UART parameters with a NULL console
2095 * too:
2096 */
2097 if (co)
2098 co->cflag = termios.c_cflag;
2099
2100 return 0;
2101}
2102EXPORT_SYMBOL_GPL(uart_set_options);
2103#endif /* CONFIG_SERIAL_CORE_CONSOLE */
2104
2105/**
2106 * uart_change_pm - set power state of the port
2107 *
2108 * @state: port descriptor
2109 * @pm_state: new state
2110 *
2111 * Locking: port->mutex has to be held
2112 */
2113static void uart_change_pm(struct uart_state *state,
2114 enum uart_pm_state pm_state)
2115{
2116 struct uart_port *port = uart_port_check(state);
2117
2118 if (state->pm_state != pm_state) {
2119 if (port && port->ops->pm)
2120 port->ops->pm(port, pm_state, state->pm_state);
2121 state->pm_state = pm_state;
2122 }
2123}
2124
2125struct uart_match {
2126 struct uart_port *port;
2127 struct uart_driver *driver;
2128};
2129
2130static int serial_match_port(struct device *dev, void *data)
2131{
2132 struct uart_match *match = data;
2133 struct tty_driver *tty_drv = match->driver->tty_driver;
2134 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
2135 match->port->line;
2136
2137 return dev->devt == devt; /* Actually, only one tty per port */
2138}
2139
2140int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
2141{
2142 struct uart_state *state = drv->state + uport->line;
2143 struct tty_port *port = &state->port;
2144 struct device *tty_dev;
2145 struct uart_match match = {uport, drv};
2146
2147 mutex_lock(&port->mutex);
2148
2149 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2150 if (tty_dev && device_may_wakeup(tty_dev)) {
2151 enable_irq_wake(uport->irq);
2152 put_device(tty_dev);
2153 mutex_unlock(&port->mutex);
2154 return 0;
2155 }
2156 put_device(tty_dev);
2157
2158 /* Nothing to do if the console is not suspending */
2159 if (!console_suspend_enabled && uart_console(uport))
2160 goto unlock;
2161
2162 uport->suspended = 1;
2163
2164 if (tty_port_initialized(port)) {
2165 const struct uart_ops *ops = uport->ops;
2166 int tries;
2167
2168 tty_port_set_suspended(port, 1);
2169 tty_port_set_initialized(port, 0);
2170
2171 spin_lock_irq(&uport->lock);
2172 ops->stop_tx(uport);
2173 ops->set_mctrl(uport, 0);
2174 ops->stop_rx(uport);
2175 spin_unlock_irq(&uport->lock);
2176
2177 /*
2178 * Wait for the transmitter to empty.
2179 */
2180 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2181 msleep(10);
2182 if (!tries)
2183 dev_err(uport->dev, "%s: Unable to drain transmitter\n",
2184 uport->name);
2185
2186 ops->shutdown(uport);
2187 }
2188
2189 /*
2190 * Disable the console device before suspending.
2191 */
2192 if (uart_console(uport))
2193 console_stop(uport->cons);
2194
2195 uart_change_pm(state, UART_PM_STATE_OFF);
2196unlock:
2197 mutex_unlock(&port->mutex);
2198
2199 return 0;
2200}
2201
2202int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2203{
2204 struct uart_state *state = drv->state + uport->line;
2205 struct tty_port *port = &state->port;
2206 struct device *tty_dev;
2207 struct uart_match match = {uport, drv};
2208 struct ktermios termios;
2209
2210 mutex_lock(&port->mutex);
2211
2212 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2213 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2214 if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq))))
2215 disable_irq_wake(uport->irq);
2216 put_device(tty_dev);
2217 mutex_unlock(&port->mutex);
2218 return 0;
2219 }
2220 put_device(tty_dev);
2221 uport->suspended = 0;
2222
2223 /*
2224 * Re-enable the console device after suspending.
2225 */
2226 if (uart_console(uport)) {
2227 /*
2228 * First try to use the console cflag setting.
2229 */
2230 memset(&termios, 0, sizeof(struct ktermios));
2231 termios.c_cflag = uport->cons->cflag;
2232
2233 /*
2234 * If that's unset, use the tty termios setting.
2235 */
2236 if (port->tty && termios.c_cflag == 0)
2237 termios = port->tty->termios;
2238
2239 if (console_suspend_enabled)
2240 uart_change_pm(state, UART_PM_STATE_ON);
2241 uport->ops->set_termios(uport, &termios, NULL);
2242 if (console_suspend_enabled)
2243 console_start(uport->cons);
2244 }
2245
2246 if (tty_port_suspended(port)) {
2247 const struct uart_ops *ops = uport->ops;
2248 int ret;
2249
2250 uart_change_pm(state, UART_PM_STATE_ON);
2251 spin_lock_irq(&uport->lock);
2252 ops->set_mctrl(uport, 0);
2253 spin_unlock_irq(&uport->lock);
2254 if (console_suspend_enabled || !uart_console(uport)) {
2255 /* Protected by port mutex for now */
2256 struct tty_struct *tty = port->tty;
2257
2258 ret = ops->startup(uport);
2259 if (ret == 0) {
2260 if (tty)
2261 uart_change_speed(tty, state, NULL);
2262 spin_lock_irq(&uport->lock);
2263 ops->set_mctrl(uport, uport->mctrl);
2264 ops->start_tx(uport);
2265 spin_unlock_irq(&uport->lock);
2266 tty_port_set_initialized(port, 1);
2267 } else {
2268 /*
2269 * Failed to resume - maybe hardware went away?
2270 * Clear the "initialized" flag so we won't try
2271 * to call the low level drivers shutdown method.
2272 */
2273 uart_shutdown(tty, state);
2274 }
2275 }
2276
2277 tty_port_set_suspended(port, 0);
2278 }
2279
2280 mutex_unlock(&port->mutex);
2281
2282 return 0;
2283}
2284
2285static inline void
2286uart_report_port(struct uart_driver *drv, struct uart_port *port)
2287{
2288 char address[64];
2289
2290 switch (port->iotype) {
2291 case UPIO_PORT:
2292 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2293 break;
2294 case UPIO_HUB6:
2295 snprintf(address, sizeof(address),
2296 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2297 break;
2298 case UPIO_MEM:
2299 case UPIO_MEM16:
2300 case UPIO_MEM32:
2301 case UPIO_MEM32BE:
2302 case UPIO_AU:
2303 case UPIO_TSI:
2304 snprintf(address, sizeof(address),
2305 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2306 break;
2307 default:
2308 strlcpy(address, "*unknown*", sizeof(address));
2309 break;
2310 }
2311
2312 pr_info("%s%s%s at %s (irq = %d, base_baud = %d) is a %s\n",
2313 port->dev ? dev_name(port->dev) : "",
2314 port->dev ? ": " : "",
2315 port->name,
2316 address, port->irq, port->uartclk / 16, uart_type(port));
2317}
2318
2319static void
2320uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2321 struct uart_port *port)
2322{
2323 unsigned int flags;
2324
2325 /*
2326 * If there isn't a port here, don't do anything further.
2327 */
2328 if (!port->iobase && !port->mapbase && !port->membase)
2329 return;
2330
2331 /*
2332 * Now do the auto configuration stuff. Note that config_port
2333 * is expected to claim the resources and map the port for us.
2334 */
2335 flags = 0;
2336 if (port->flags & UPF_AUTO_IRQ)
2337 flags |= UART_CONFIG_IRQ;
2338 if (port->flags & UPF_BOOT_AUTOCONF) {
2339 if (!(port->flags & UPF_FIXED_TYPE)) {
2340 port->type = PORT_UNKNOWN;
2341 flags |= UART_CONFIG_TYPE;
2342 }
2343 port->ops->config_port(port, flags);
2344 }
2345
2346 if (port->type != PORT_UNKNOWN) {
2347 unsigned long flags;
2348
2349 uart_report_port(drv, port);
2350
2351 /* Power up port for set_mctrl() */
2352 uart_change_pm(state, UART_PM_STATE_ON);
2353
2354 /*
2355 * Ensure that the modem control lines are de-activated.
2356 * keep the DTR setting that is set in uart_set_options()
2357 * We probably don't need a spinlock around this, but
2358 */
2359 spin_lock_irqsave(&port->lock, flags);
2360 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2361 spin_unlock_irqrestore(&port->lock, flags);
2362
2363 /*
2364 * If this driver supports console, and it hasn't been
2365 * successfully registered yet, try to re-register it.
2366 * It may be that the port was not available.
2367 */
2368 if (port->cons && !(port->cons->flags & CON_ENABLED))
2369 register_console(port->cons);
2370
2371 /*
2372 * Power down all ports by default, except the
2373 * console if we have one.
2374 */
2375 if (!uart_console(port))
2376 uart_change_pm(state, UART_PM_STATE_OFF);
2377 }
2378}
2379
2380#ifdef CONFIG_CONSOLE_POLL
2381
2382static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2383{
2384 struct uart_driver *drv = driver->driver_state;
2385 struct uart_state *state = drv->state + line;
2386 struct tty_port *tport;
2387 struct uart_port *port;
2388 int baud = 9600;
2389 int bits = 8;
2390 int parity = 'n';
2391 int flow = 'n';
2392 int ret = 0;
2393
2394 tport = &state->port;
2395 mutex_lock(&tport->mutex);
2396
2397 port = uart_port_check(state);
2398 if (!port || !(port->ops->poll_get_char && port->ops->poll_put_char)) {
2399 ret = -1;
2400 goto out;
2401 }
2402
2403 if (port->ops->poll_init) {
2404 /*
2405 * We don't set initialized as we only initialized the hw,
2406 * e.g. state->xmit is still uninitialized.
2407 */
2408 if (!tty_port_initialized(tport))
2409 ret = port->ops->poll_init(port);
2410 }
2411
2412 if (!ret && options) {
2413 uart_parse_options(options, &baud, &parity, &bits, &flow);
2414 ret = uart_set_options(port, NULL, baud, parity, bits, flow);
2415 }
2416out:
2417 mutex_unlock(&tport->mutex);
2418 return ret;
2419}
2420
2421static int uart_poll_get_char(struct tty_driver *driver, int line)
2422{
2423 struct uart_driver *drv = driver->driver_state;
2424 struct uart_state *state = drv->state + line;
2425 struct uart_port *port;
2426 int ret = -1;
2427
2428 port = uart_port_ref(state);
2429 if (port) {
2430 ret = port->ops->poll_get_char(port);
2431 uart_port_deref(port);
2432 }
2433
2434 return ret;
2435}
2436
2437static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2438{
2439 struct uart_driver *drv = driver->driver_state;
2440 struct uart_state *state = drv->state + line;
2441 struct uart_port *port;
2442
2443 port = uart_port_ref(state);
2444 if (!port)
2445 return;
2446
2447 if (ch == '\n')
2448 port->ops->poll_put_char(port, '\r');
2449 port->ops->poll_put_char(port, ch);
2450 uart_port_deref(port);
2451}
2452#endif
2453
2454static const struct tty_operations uart_ops = {
2455 .install = uart_install,
2456 .open = uart_open,
2457 .close = uart_close,
2458 .write = uart_write,
2459 .put_char = uart_put_char,
2460 .flush_chars = uart_flush_chars,
2461 .write_room = uart_write_room,
2462 .chars_in_buffer= uart_chars_in_buffer,
2463 .flush_buffer = uart_flush_buffer,
2464 .ioctl = uart_ioctl,
2465 .throttle = uart_throttle,
2466 .unthrottle = uart_unthrottle,
2467 .send_xchar = uart_send_xchar,
2468 .set_termios = uart_set_termios,
2469 .set_ldisc = uart_set_ldisc,
2470 .stop = uart_stop,
2471 .start = uart_start,
2472 .hangup = uart_hangup,
2473 .break_ctl = uart_break_ctl,
2474 .wait_until_sent= uart_wait_until_sent,
2475#ifdef CONFIG_PROC_FS
2476 .proc_show = uart_proc_show,
2477#endif
2478 .tiocmget = uart_tiocmget,
2479 .tiocmset = uart_tiocmset,
2480 .set_serial = uart_set_info_user,
2481 .get_serial = uart_get_info_user,
2482 .get_icount = uart_get_icount,
2483#ifdef CONFIG_CONSOLE_POLL
2484 .poll_init = uart_poll_init,
2485 .poll_get_char = uart_poll_get_char,
2486 .poll_put_char = uart_poll_put_char,
2487#endif
2488};
2489
2490static const struct tty_port_operations uart_port_ops = {
2491 .carrier_raised = uart_carrier_raised,
2492 .dtr_rts = uart_dtr_rts,
2493 .activate = uart_port_activate,
2494 .shutdown = uart_tty_port_shutdown,
2495};
2496
2497/**
2498 * uart_register_driver - register a driver with the uart core layer
2499 * @drv: low level driver structure
2500 *
2501 * Register a uart driver with the core driver. We in turn register
2502 * with the tty layer, and initialise the core driver per-port state.
2503 *
2504 * We have a proc file in /proc/tty/driver which is named after the
2505 * normal driver.
2506 *
2507 * drv->port should be NULL, and the per-port structures should be
2508 * registered using uart_add_one_port after this call has succeeded.
2509 */
2510int uart_register_driver(struct uart_driver *drv)
2511{
2512 struct tty_driver *normal;
2513 int i, retval = -ENOMEM;
2514
2515 BUG_ON(drv->state);
2516
2517 /*
2518 * Maybe we should be using a slab cache for this, especially if
2519 * we have a large number of ports to handle.
2520 */
2521 drv->state = kcalloc(drv->nr, sizeof(struct uart_state), GFP_KERNEL);
2522 if (!drv->state)
2523 goto out;
2524
2525 normal = alloc_tty_driver(drv->nr);
2526 if (!normal)
2527 goto out_kfree;
2528
2529 drv->tty_driver = normal;
2530
2531 normal->driver_name = drv->driver_name;
2532 normal->name = drv->dev_name;
2533 normal->major = drv->major;
2534 normal->minor_start = drv->minor;
2535 normal->type = TTY_DRIVER_TYPE_SERIAL;
2536 normal->subtype = SERIAL_TYPE_NORMAL;
2537 normal->init_termios = tty_std_termios;
2538 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2539 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2540 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2541 normal->driver_state = drv;
2542 tty_set_operations(normal, &uart_ops);
2543
2544 /*
2545 * Initialise the UART state(s).
2546 */
2547 for (i = 0; i < drv->nr; i++) {
2548 struct uart_state *state = drv->state + i;
2549 struct tty_port *port = &state->port;
2550
2551 tty_port_init(port);
2552 port->ops = &uart_port_ops;
2553 }
2554
2555 retval = tty_register_driver(normal);
2556 if (retval >= 0)
2557 return retval;
2558
2559 for (i = 0; i < drv->nr; i++)
2560 tty_port_destroy(&drv->state[i].port);
2561 put_tty_driver(normal);
2562out_kfree:
2563 kfree(drv->state);
2564out:
2565 return retval;
2566}
2567
2568/**
2569 * uart_unregister_driver - remove a driver from the uart core layer
2570 * @drv: low level driver structure
2571 *
2572 * Remove all references to a driver from the core driver. The low
2573 * level driver must have removed all its ports via the
2574 * uart_remove_one_port() if it registered them with uart_add_one_port().
2575 * (ie, drv->port == NULL)
2576 */
2577void uart_unregister_driver(struct uart_driver *drv)
2578{
2579 struct tty_driver *p = drv->tty_driver;
2580 unsigned int i;
2581
2582 tty_unregister_driver(p);
2583 put_tty_driver(p);
2584 for (i = 0; i < drv->nr; i++)
2585 tty_port_destroy(&drv->state[i].port);
2586 kfree(drv->state);
2587 drv->state = NULL;
2588 drv->tty_driver = NULL;
2589}
2590
2591struct tty_driver *uart_console_device(struct console *co, int *index)
2592{
2593 struct uart_driver *p = co->data;
2594 *index = co->index;
2595 return p->tty_driver;
2596}
2597EXPORT_SYMBOL_GPL(uart_console_device);
2598
2599static ssize_t uartclk_show(struct device *dev,
2600 struct device_attribute *attr, char *buf)
2601{
2602 struct serial_struct tmp;
2603 struct tty_port *port = dev_get_drvdata(dev);
2604
2605 uart_get_info(port, &tmp);
2606 return sprintf(buf, "%d\n", tmp.baud_base * 16);
2607}
2608
2609static ssize_t type_show(struct device *dev,
2610 struct device_attribute *attr, char *buf)
2611{
2612 struct serial_struct tmp;
2613 struct tty_port *port = dev_get_drvdata(dev);
2614
2615 uart_get_info(port, &tmp);
2616 return sprintf(buf, "%d\n", tmp.type);
2617}
2618
2619static ssize_t line_show(struct device *dev,
2620 struct device_attribute *attr, char *buf)
2621{
2622 struct serial_struct tmp;
2623 struct tty_port *port = dev_get_drvdata(dev);
2624
2625 uart_get_info(port, &tmp);
2626 return sprintf(buf, "%d\n", tmp.line);
2627}
2628
2629static ssize_t port_show(struct device *dev,
2630 struct device_attribute *attr, char *buf)
2631{
2632 struct serial_struct tmp;
2633 struct tty_port *port = dev_get_drvdata(dev);
2634 unsigned long ioaddr;
2635
2636 uart_get_info(port, &tmp);
2637 ioaddr = tmp.port;
2638 if (HIGH_BITS_OFFSET)
2639 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2640 return sprintf(buf, "0x%lX\n", ioaddr);
2641}
2642
2643static ssize_t irq_show(struct device *dev,
2644 struct device_attribute *attr, char *buf)
2645{
2646 struct serial_struct tmp;
2647 struct tty_port *port = dev_get_drvdata(dev);
2648
2649 uart_get_info(port, &tmp);
2650 return sprintf(buf, "%d\n", tmp.irq);
2651}
2652
2653static ssize_t flags_show(struct device *dev,
2654 struct device_attribute *attr, char *buf)
2655{
2656 struct serial_struct tmp;
2657 struct tty_port *port = dev_get_drvdata(dev);
2658
2659 uart_get_info(port, &tmp);
2660 return sprintf(buf, "0x%X\n", tmp.flags);
2661}
2662
2663static ssize_t xmit_fifo_size_show(struct device *dev,
2664 struct device_attribute *attr, char *buf)
2665{
2666 struct serial_struct tmp;
2667 struct tty_port *port = dev_get_drvdata(dev);
2668
2669 uart_get_info(port, &tmp);
2670 return sprintf(buf, "%d\n", tmp.xmit_fifo_size);
2671}
2672
2673static ssize_t close_delay_show(struct device *dev,
2674 struct device_attribute *attr, char *buf)
2675{
2676 struct serial_struct tmp;
2677 struct tty_port *port = dev_get_drvdata(dev);
2678
2679 uart_get_info(port, &tmp);
2680 return sprintf(buf, "%d\n", tmp.close_delay);
2681}
2682
2683static ssize_t closing_wait_show(struct device *dev,
2684 struct device_attribute *attr, char *buf)
2685{
2686 struct serial_struct tmp;
2687 struct tty_port *port = dev_get_drvdata(dev);
2688
2689 uart_get_info(port, &tmp);
2690 return sprintf(buf, "%d\n", tmp.closing_wait);
2691}
2692
2693static ssize_t custom_divisor_show(struct device *dev,
2694 struct device_attribute *attr, char *buf)
2695{
2696 struct serial_struct tmp;
2697 struct tty_port *port = dev_get_drvdata(dev);
2698
2699 uart_get_info(port, &tmp);
2700 return sprintf(buf, "%d\n", tmp.custom_divisor);
2701}
2702
2703static ssize_t io_type_show(struct device *dev,
2704 struct device_attribute *attr, char *buf)
2705{
2706 struct serial_struct tmp;
2707 struct tty_port *port = dev_get_drvdata(dev);
2708
2709 uart_get_info(port, &tmp);
2710 return sprintf(buf, "%d\n", tmp.io_type);
2711}
2712
2713static ssize_t iomem_base_show(struct device *dev,
2714 struct device_attribute *attr, char *buf)
2715{
2716 struct serial_struct tmp;
2717 struct tty_port *port = dev_get_drvdata(dev);
2718
2719 uart_get_info(port, &tmp);
2720 return sprintf(buf, "0x%lX\n", (unsigned long)tmp.iomem_base);
2721}
2722
2723static ssize_t iomem_reg_shift_show(struct device *dev,
2724 struct device_attribute *attr, char *buf)
2725{
2726 struct serial_struct tmp;
2727 struct tty_port *port = dev_get_drvdata(dev);
2728
2729 uart_get_info(port, &tmp);
2730 return sprintf(buf, "%d\n", tmp.iomem_reg_shift);
2731}
2732
2733static ssize_t console_show(struct device *dev,
2734 struct device_attribute *attr, char *buf)
2735{
2736 struct tty_port *port = dev_get_drvdata(dev);
2737 struct uart_state *state = container_of(port, struct uart_state, port);
2738 struct uart_port *uport;
2739 bool console = false;
2740
2741 mutex_lock(&port->mutex);
2742 uport = uart_port_check(state);
2743 if (uport)
2744 console = uart_console_enabled(uport);
2745 mutex_unlock(&port->mutex);
2746
2747 return sprintf(buf, "%c\n", console ? 'Y' : 'N');
2748}
2749
2750static ssize_t console_store(struct device *dev,
2751 struct device_attribute *attr, const char *buf, size_t count)
2752{
2753 struct tty_port *port = dev_get_drvdata(dev);
2754 struct uart_state *state = container_of(port, struct uart_state, port);
2755 struct uart_port *uport;
2756 bool oldconsole, newconsole;
2757 int ret;
2758
2759 ret = kstrtobool(buf, &newconsole);
2760 if (ret)
2761 return ret;
2762
2763 mutex_lock(&port->mutex);
2764 uport = uart_port_check(state);
2765 if (uport) {
2766 oldconsole = uart_console_enabled(uport);
2767 if (oldconsole && !newconsole) {
2768 ret = unregister_console(uport->cons);
2769 } else if (!oldconsole && newconsole) {
2770 if (uart_console(uport)) {
2771 uport->console_reinit = 1;
2772 register_console(uport->cons);
2773 } else {
2774 ret = -ENOENT;
2775 }
2776 }
2777 } else {
2778 ret = -ENXIO;
2779 }
2780 mutex_unlock(&port->mutex);
2781
2782 return ret < 0 ? ret : count;
2783}
2784
2785static DEVICE_ATTR_RO(uartclk);
2786static DEVICE_ATTR_RO(type);
2787static DEVICE_ATTR_RO(line);
2788static DEVICE_ATTR_RO(port);
2789static DEVICE_ATTR_RO(irq);
2790static DEVICE_ATTR_RO(flags);
2791static DEVICE_ATTR_RO(xmit_fifo_size);
2792static DEVICE_ATTR_RO(close_delay);
2793static DEVICE_ATTR_RO(closing_wait);
2794static DEVICE_ATTR_RO(custom_divisor);
2795static DEVICE_ATTR_RO(io_type);
2796static DEVICE_ATTR_RO(iomem_base);
2797static DEVICE_ATTR_RO(iomem_reg_shift);
2798static DEVICE_ATTR_RW(console);
2799
2800static struct attribute *tty_dev_attrs[] = {
2801 &dev_attr_uartclk.attr,
2802 &dev_attr_type.attr,
2803 &dev_attr_line.attr,
2804 &dev_attr_port.attr,
2805 &dev_attr_irq.attr,
2806 &dev_attr_flags.attr,
2807 &dev_attr_xmit_fifo_size.attr,
2808 &dev_attr_close_delay.attr,
2809 &dev_attr_closing_wait.attr,
2810 &dev_attr_custom_divisor.attr,
2811 &dev_attr_io_type.attr,
2812 &dev_attr_iomem_base.attr,
2813 &dev_attr_iomem_reg_shift.attr,
2814 &dev_attr_console.attr,
2815 NULL
2816};
2817
2818static const struct attribute_group tty_dev_attr_group = {
2819 .attrs = tty_dev_attrs,
2820};
2821
2822/**
2823 * uart_add_one_port - attach a driver-defined port structure
2824 * @drv: pointer to the uart low level driver structure for this port
2825 * @uport: uart port structure to use for this port.
2826 *
2827 * Context: task context, might sleep
2828 *
2829 * This allows the driver to register its own uart_port structure
2830 * with the core driver. The main purpose is to allow the low
2831 * level uart drivers to expand uart_port, rather than having yet
2832 * more levels of structures.
2833 */
2834int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2835{
2836 struct uart_state *state;
2837 struct tty_port *port;
2838 int ret = 0;
2839 struct device *tty_dev;
2840 int num_groups;
2841
2842 if (uport->line >= drv->nr)
2843 return -EINVAL;
2844
2845 state = drv->state + uport->line;
2846 port = &state->port;
2847
2848 mutex_lock(&port_mutex);
2849 mutex_lock(&port->mutex);
2850 if (state->uart_port) {
2851 ret = -EINVAL;
2852 goto out;
2853 }
2854
2855 /* Link the port to the driver state table and vice versa */
2856 atomic_set(&state->refcount, 1);
2857 init_waitqueue_head(&state->remove_wait);
2858 state->uart_port = uport;
2859 uport->state = state;
2860
2861 state->pm_state = UART_PM_STATE_UNDEFINED;
2862 uport->cons = drv->cons;
2863 uport->minor = drv->tty_driver->minor_start + uport->line;
2864 uport->name = kasprintf(GFP_KERNEL, "%s%d", drv->dev_name,
2865 drv->tty_driver->name_base + uport->line);
2866 if (!uport->name) {
2867 ret = -ENOMEM;
2868 goto out;
2869 }
2870
2871 /*
2872 * If this port is in use as a console then the spinlock is already
2873 * initialised.
2874 */
2875 if (!uart_console_enabled(uport))
2876 uart_port_spin_lock_init(uport);
2877
2878 if (uport->cons && uport->dev)
2879 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2880
2881 tty_port_link_device(port, drv->tty_driver, uport->line);
2882 uart_configure_port(drv, state, uport);
2883
2884 port->console = uart_console(uport);
2885
2886 num_groups = 2;
2887 if (uport->attr_group)
2888 num_groups++;
2889
2890 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2891 GFP_KERNEL);
2892 if (!uport->tty_groups) {
2893 ret = -ENOMEM;
2894 goto out;
2895 }
2896 uport->tty_groups[0] = &tty_dev_attr_group;
2897 if (uport->attr_group)
2898 uport->tty_groups[1] = uport->attr_group;
2899
2900 /*
2901 * Register the port whether it's detected or not. This allows
2902 * setserial to be used to alter this port's parameters.
2903 */
2904 tty_dev = tty_port_register_device_attr_serdev(port, drv->tty_driver,
2905 uport->line, uport->dev, port, uport->tty_groups);
2906 if (!IS_ERR(tty_dev)) {
2907 device_set_wakeup_capable(tty_dev, 1);
2908 } else {
2909 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2910 uport->line);
2911 }
2912
2913 /*
2914 * Ensure UPF_DEAD is not set.
2915 */
2916 uport->flags &= ~UPF_DEAD;
2917
2918 out:
2919 mutex_unlock(&port->mutex);
2920 mutex_unlock(&port_mutex);
2921
2922 return ret;
2923}
2924
2925/**
2926 * uart_remove_one_port - detach a driver defined port structure
2927 * @drv: pointer to the uart low level driver structure for this port
2928 * @uport: uart port structure for this port
2929 *
2930 * Context: task context, might sleep
2931 *
2932 * This unhooks (and hangs up) the specified port structure from the
2933 * core driver. No further calls will be made to the low-level code
2934 * for this port.
2935 */
2936int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2937{
2938 struct uart_state *state = drv->state + uport->line;
2939 struct tty_port *port = &state->port;
2940 struct uart_port *uart_port;
2941 struct tty_struct *tty;
2942 int ret = 0;
2943
2944 mutex_lock(&port_mutex);
2945
2946 /*
2947 * Mark the port "dead" - this prevents any opens from
2948 * succeeding while we shut down the port.
2949 */
2950 mutex_lock(&port->mutex);
2951 uart_port = uart_port_check(state);
2952 if (uart_port != uport)
2953 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2954 uart_port, uport);
2955
2956 if (!uart_port) {
2957 mutex_unlock(&port->mutex);
2958 ret = -EINVAL;
2959 goto out;
2960 }
2961 uport->flags |= UPF_DEAD;
2962 mutex_unlock(&port->mutex);
2963
2964 /*
2965 * Remove the devices from the tty layer
2966 */
2967 tty_port_unregister_device(port, drv->tty_driver, uport->line);
2968
2969 tty = tty_port_tty_get(port);
2970 if (tty) {
2971 tty_vhangup(port->tty);
2972 tty_kref_put(tty);
2973 }
2974
2975 /*
2976 * If the port is used as a console, unregister it
2977 */
2978 if (uart_console(uport))
2979 unregister_console(uport->cons);
2980
2981 /*
2982 * Free the port IO and memory resources, if any.
2983 */
2984 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
2985 uport->ops->release_port(uport);
2986 kfree(uport->tty_groups);
2987 kfree(uport->name);
2988
2989 /*
2990 * Indicate that there isn't a port here anymore.
2991 */
2992 uport->type = PORT_UNKNOWN;
2993
2994 mutex_lock(&port->mutex);
2995 WARN_ON(atomic_dec_return(&state->refcount) < 0);
2996 wait_event(state->remove_wait, !atomic_read(&state->refcount));
2997 state->uart_port = NULL;
2998 mutex_unlock(&port->mutex);
2999out:
3000 mutex_unlock(&port_mutex);
3001
3002 return ret;
3003}
3004
3005/*
3006 * Are the two ports equivalent?
3007 */
3008bool uart_match_port(const struct uart_port *port1,
3009 const struct uart_port *port2)
3010{
3011 if (port1->iotype != port2->iotype)
3012 return false;
3013
3014 switch (port1->iotype) {
3015 case UPIO_PORT:
3016 return port1->iobase == port2->iobase;
3017 case UPIO_HUB6:
3018 return port1->iobase == port2->iobase &&
3019 port1->hub6 == port2->hub6;
3020 case UPIO_MEM:
3021 case UPIO_MEM16:
3022 case UPIO_MEM32:
3023 case UPIO_MEM32BE:
3024 case UPIO_AU:
3025 case UPIO_TSI:
3026 return port1->mapbase == port2->mapbase;
3027 }
3028
3029 return false;
3030}
3031EXPORT_SYMBOL(uart_match_port);
3032
3033/**
3034 * uart_handle_dcd_change - handle a change of carrier detect state
3035 * @uport: uart_port structure for the open port
3036 * @status: new carrier detect status, nonzero if active
3037 *
3038 * Caller must hold uport->lock
3039 */
3040void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
3041{
3042 struct tty_port *port = &uport->state->port;
3043 struct tty_struct *tty = port->tty;
3044 struct tty_ldisc *ld;
3045
3046 lockdep_assert_held_once(&uport->lock);
3047
3048 if (tty) {
3049 ld = tty_ldisc_ref(tty);
3050 if (ld) {
3051 if (ld->ops->dcd_change)
3052 ld->ops->dcd_change(tty, status);
3053 tty_ldisc_deref(ld);
3054 }
3055 }
3056
3057 uport->icount.dcd++;
3058
3059 if (uart_dcd_enabled(uport)) {
3060 if (status)
3061 wake_up_interruptible(&port->open_wait);
3062 else if (tty)
3063 tty_hangup(tty);
3064 }
3065}
3066EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
3067
3068/**
3069 * uart_handle_cts_change - handle a change of clear-to-send state
3070 * @uport: uart_port structure for the open port
3071 * @status: new clear to send status, nonzero if active
3072 *
3073 * Caller must hold uport->lock
3074 */
3075void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
3076{
3077 lockdep_assert_held_once(&uport->lock);
3078
3079 uport->icount.cts++;
3080
3081 if (uart_softcts_mode(uport)) {
3082 if (uport->hw_stopped) {
3083 if (status) {
3084 uport->hw_stopped = 0;
3085 uport->ops->start_tx(uport);
3086 uart_write_wakeup(uport);
3087 }
3088 } else {
3089 if (!status) {
3090 uport->hw_stopped = 1;
3091 uport->ops->stop_tx(uport);
3092 }
3093 }
3094
3095 }
3096}
3097EXPORT_SYMBOL_GPL(uart_handle_cts_change);
3098
3099/**
3100 * uart_insert_char - push a char to the uart layer
3101 *
3102 * User is responsible to call tty_flip_buffer_push when they are done with
3103 * insertion.
3104 *
3105 * @port: corresponding port
3106 * @status: state of the serial port RX buffer (LSR for 8250)
3107 * @overrun: mask of overrun bits in @status
3108 * @ch: character to push
3109 * @flag: flag for the character (see TTY_NORMAL and friends)
3110 */
3111void uart_insert_char(struct uart_port *port, unsigned int status,
3112 unsigned int overrun, unsigned int ch, unsigned int flag)
3113{
3114 struct tty_port *tport = &port->state->port;
3115
3116 if ((status & port->ignore_status_mask & ~overrun) == 0)
3117 if (tty_insert_flip_char(tport, ch, flag) == 0)
3118 ++port->icount.buf_overrun;
3119
3120 /*
3121 * Overrun is special. Since it's reported immediately,
3122 * it doesn't affect the current character.
3123 */
3124 if (status & ~port->ignore_status_mask & overrun)
3125 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
3126 ++port->icount.buf_overrun;
3127}
3128EXPORT_SYMBOL_GPL(uart_insert_char);
3129
3130#ifdef CONFIG_MAGIC_SYSRQ_SERIAL
3131static const char sysrq_toggle_seq[] = CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE;
3132
3133static void uart_sysrq_on(struct work_struct *w)
3134{
3135 int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq);
3136
3137 sysrq_toggle_support(1);
3138 pr_info("SysRq is enabled by magic sequence '%*pE' on serial\n",
3139 sysrq_toggle_seq_len, sysrq_toggle_seq);
3140}
3141static DECLARE_WORK(sysrq_enable_work, uart_sysrq_on);
3142
3143/**
3144 * uart_try_toggle_sysrq - Enables SysRq from serial line
3145 * @port: uart_port structure where char(s) after BREAK met
3146 * @ch: new character in the sequence after received BREAK
3147 *
3148 * Enables magic SysRq when the required sequence is met on port
3149 * (see CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE).
3150 *
3151 * Returns false if @ch is out of enabling sequence and should be
3152 * handled some other way, true if @ch was consumed.
3153 */
3154bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch)
3155{
3156 int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq);
3157
3158 if (!sysrq_toggle_seq_len)
3159 return false;
3160
3161 BUILD_BUG_ON(ARRAY_SIZE(sysrq_toggle_seq) >= U8_MAX);
3162 if (sysrq_toggle_seq[port->sysrq_seq] != ch) {
3163 port->sysrq_seq = 0;
3164 return false;
3165 }
3166
3167 if (++port->sysrq_seq < sysrq_toggle_seq_len) {
3168 port->sysrq = jiffies + SYSRQ_TIMEOUT;
3169 return true;
3170 }
3171
3172 schedule_work(&sysrq_enable_work);
3173
3174 port->sysrq = 0;
3175 return true;
3176}
3177EXPORT_SYMBOL_GPL(uart_try_toggle_sysrq);
3178#endif
3179
3180EXPORT_SYMBOL(uart_write_wakeup);
3181EXPORT_SYMBOL(uart_register_driver);
3182EXPORT_SYMBOL(uart_unregister_driver);
3183EXPORT_SYMBOL(uart_suspend_port);
3184EXPORT_SYMBOL(uart_resume_port);
3185EXPORT_SYMBOL(uart_add_one_port);
3186EXPORT_SYMBOL(uart_remove_one_port);
3187
3188/**
3189 * uart_get_rs485_mode() - retrieve rs485 properties for given uart
3190 * @port: uart device's target port
3191 *
3192 * This function implements the device tree binding described in
3193 * Documentation/devicetree/bindings/serial/rs485.txt.
3194 */
3195int uart_get_rs485_mode(struct uart_port *port)
3196{
3197 struct serial_rs485 *rs485conf = &port->rs485;
3198 struct device *dev = port->dev;
3199 u32 rs485_delay[2];
3200 int ret;
3201
3202 ret = device_property_read_u32_array(dev, "rs485-rts-delay",
3203 rs485_delay, 2);
3204 if (!ret) {
3205 rs485conf->delay_rts_before_send = rs485_delay[0];
3206 rs485conf->delay_rts_after_send = rs485_delay[1];
3207 } else {
3208 rs485conf->delay_rts_before_send = 0;
3209 rs485conf->delay_rts_after_send = 0;
3210 }
3211
3212 /*
3213 * Clear full-duplex and enabled flags, set RTS polarity to active high
3214 * to get to a defined state with the following properties:
3215 */
3216 rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED |
3217 SER_RS485_TERMINATE_BUS |
3218 SER_RS485_RTS_AFTER_SEND);
3219 rs485conf->flags |= SER_RS485_RTS_ON_SEND;
3220
3221 if (device_property_read_bool(dev, "rs485-rx-during-tx"))
3222 rs485conf->flags |= SER_RS485_RX_DURING_TX;
3223
3224 if (device_property_read_bool(dev, "linux,rs485-enabled-at-boot-time"))
3225 rs485conf->flags |= SER_RS485_ENABLED;
3226
3227 if (device_property_read_bool(dev, "rs485-rts-active-low")) {
3228 rs485conf->flags &= ~SER_RS485_RTS_ON_SEND;
3229 rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
3230 }
3231
3232 /*
3233 * Disabling termination by default is the safe choice: Else if many
3234 * bus participants enable it, no communication is possible at all.
3235 * Works fine for short cables and users may enable for longer cables.
3236 */
3237 port->rs485_term_gpio = devm_gpiod_get_optional(dev, "rs485-term",
3238 GPIOD_OUT_LOW);
3239 if (IS_ERR(port->rs485_term_gpio)) {
3240 ret = PTR_ERR(port->rs485_term_gpio);
3241 port->rs485_term_gpio = NULL;
3242 return dev_err_probe(dev, ret, "Cannot get rs485-term-gpios\n");
3243 }
3244
3245 return 0;
3246}
3247EXPORT_SYMBOL_GPL(uart_get_rs485_mode);
3248
3249MODULE_DESCRIPTION("Serial driver core");
3250MODULE_LICENSE("GPL");