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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/*
2 * Driver core for serial ports
3 *
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
5 *
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 */
23#include <linux/module.h>
24#include <linux/tty.h>
25#include <linux/tty_flip.h>
26#include <linux/slab.h>
27#include <linux/init.h>
28#include <linux/console.h>
29#include <linux/of.h>
30#include <linux/proc_fs.h>
31#include <linux/seq_file.h>
32#include <linux/device.h>
33#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
34#include <linux/serial_core.h>
35#include <linux/delay.h>
36#include <linux/mutex.h>
37
38#include <asm/irq.h>
39#include <linux/uaccess.h>
40
41/*
42 * This is used to lock changes in serial line configuration.
43 */
44static DEFINE_MUTEX(port_mutex);
45
46/*
47 * lockdep: port->lock is initialized in two places, but we
48 * want only one lock-class:
49 */
50static struct lock_class_key port_lock_key;
51
52#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
53
54static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
55 struct ktermios *old_termios);
56static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
57static void uart_change_pm(struct uart_state *state,
58 enum uart_pm_state pm_state);
59
60static void uart_port_shutdown(struct tty_port *port);
61
62static int uart_dcd_enabled(struct uart_port *uport)
63{
64 return !!(uport->status & UPSTAT_DCD_ENABLE);
65}
66
67static inline struct uart_port *uart_port_ref(struct uart_state *state)
68{
69 if (atomic_add_unless(&state->refcount, 1, 0))
70 return state->uart_port;
71 return NULL;
72}
73
74static inline void uart_port_deref(struct uart_port *uport)
75{
76 if (atomic_dec_and_test(&uport->state->refcount))
77 wake_up(&uport->state->remove_wait);
78}
79
80#define uart_port_lock(state, flags) \
81 ({ \
82 struct uart_port *__uport = uart_port_ref(state); \
83 if (__uport) \
84 spin_lock_irqsave(&__uport->lock, flags); \
85 __uport; \
86 })
87
88#define uart_port_unlock(uport, flags) \
89 ({ \
90 struct uart_port *__uport = uport; \
91 if (__uport) { \
92 spin_unlock_irqrestore(&__uport->lock, flags); \
93 uart_port_deref(__uport); \
94 } \
95 })
96
97static inline struct uart_port *uart_port_check(struct uart_state *state)
98{
99 lockdep_assert_held(&state->port.mutex);
100 return state->uart_port;
101}
102
103/*
104 * This routine is used by the interrupt handler to schedule processing in
105 * the software interrupt portion of the driver.
106 */
107void uart_write_wakeup(struct uart_port *port)
108{
109 struct uart_state *state = port->state;
110 /*
111 * This means you called this function _after_ the port was
112 * closed. No cookie for you.
113 */
114 BUG_ON(!state);
115 tty_port_tty_wakeup(&state->port);
116}
117
118static void uart_stop(struct tty_struct *tty)
119{
120 struct uart_state *state = tty->driver_data;
121 struct uart_port *port;
122 unsigned long flags;
123
124 port = uart_port_lock(state, flags);
125 if (port)
126 port->ops->stop_tx(port);
127 uart_port_unlock(port, flags);
128}
129
130static void __uart_start(struct tty_struct *tty)
131{
132 struct uart_state *state = tty->driver_data;
133 struct uart_port *port = state->uart_port;
134
135 if (port && !uart_tx_stopped(port))
136 port->ops->start_tx(port);
137}
138
139static void uart_start(struct tty_struct *tty)
140{
141 struct uart_state *state = tty->driver_data;
142 struct uart_port *port;
143 unsigned long flags;
144
145 port = uart_port_lock(state, flags);
146 __uart_start(tty);
147 uart_port_unlock(port, flags);
148}
149
150static void
151uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
152{
153 unsigned long flags;
154 unsigned int old;
155
156 spin_lock_irqsave(&port->lock, flags);
157 old = port->mctrl;
158 port->mctrl = (old & ~clear) | set;
159 if (old != port->mctrl)
160 port->ops->set_mctrl(port, port->mctrl);
161 spin_unlock_irqrestore(&port->lock, flags);
162}
163
164#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
165#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
166
167/*
168 * Startup the port. This will be called once per open. All calls
169 * will be serialised by the per-port mutex.
170 */
171static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
172 int init_hw)
173{
174 struct uart_port *uport = uart_port_check(state);
175 unsigned long page;
176 int retval = 0;
177
178 if (uport->type == PORT_UNKNOWN)
179 return 1;
180
181 /*
182 * Make sure the device is in D0 state.
183 */
184 uart_change_pm(state, UART_PM_STATE_ON);
185
186 /*
187 * Initialise and allocate the transmit and temporary
188 * buffer.
189 */
190 if (!state->xmit.buf) {
191 /* This is protected by the per port mutex */
192 page = get_zeroed_page(GFP_KERNEL);
193 if (!page)
194 return -ENOMEM;
195
196 state->xmit.buf = (unsigned char *) page;
197 uart_circ_clear(&state->xmit);
198 }
199
200 retval = uport->ops->startup(uport);
201 if (retval == 0) {
202 if (uart_console(uport) && uport->cons->cflag) {
203 tty->termios.c_cflag = uport->cons->cflag;
204 uport->cons->cflag = 0;
205 }
206 /*
207 * Initialise the hardware port settings.
208 */
209 uart_change_speed(tty, state, NULL);
210
211 /*
212 * Setup the RTS and DTR signals once the
213 * port is open and ready to respond.
214 */
215 if (init_hw && C_BAUD(tty))
216 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
217 }
218
219 /*
220 * This is to allow setserial on this port. People may want to set
221 * port/irq/type and then reconfigure the port properly if it failed
222 * now.
223 */
224 if (retval && capable(CAP_SYS_ADMIN))
225 return 1;
226
227 return retval;
228}
229
230static int uart_startup(struct tty_struct *tty, struct uart_state *state,
231 int init_hw)
232{
233 struct tty_port *port = &state->port;
234 int retval;
235
236 if (tty_port_initialized(port))
237 return 0;
238
239 retval = uart_port_startup(tty, state, init_hw);
240 if (retval)
241 set_bit(TTY_IO_ERROR, &tty->flags);
242
243 return retval;
244}
245
246/*
247 * This routine will shutdown a serial port; interrupts are disabled, and
248 * DTR is dropped if the hangup on close termio flag is on. Calls to
249 * uart_shutdown are serialised by the per-port semaphore.
250 *
251 * uport == NULL if uart_port has already been removed
252 */
253static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
254{
255 struct uart_port *uport = uart_port_check(state);
256 struct tty_port *port = &state->port;
257
258 /*
259 * Set the TTY IO error marker
260 */
261 if (tty)
262 set_bit(TTY_IO_ERROR, &tty->flags);
263
264 if (tty_port_initialized(port)) {
265 tty_port_set_initialized(port, 0);
266
267 /*
268 * Turn off DTR and RTS early.
269 */
270 if (uport && uart_console(uport) && tty)
271 uport->cons->cflag = tty->termios.c_cflag;
272
273 if (!tty || C_HUPCL(tty))
274 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
275
276 uart_port_shutdown(port);
277 }
278
279 /*
280 * It's possible for shutdown to be called after suspend if we get
281 * a DCD drop (hangup) at just the right time. Clear suspended bit so
282 * we don't try to resume a port that has been shutdown.
283 */
284 tty_port_set_suspended(port, 0);
285
286 /*
287 * Free the transmit buffer page.
288 */
289 if (state->xmit.buf) {
290 free_page((unsigned long)state->xmit.buf);
291 state->xmit.buf = NULL;
292 }
293}
294
295/**
296 * uart_update_timeout - update per-port FIFO timeout.
297 * @port: uart_port structure describing the port
298 * @cflag: termios cflag value
299 * @baud: speed of the port
300 *
301 * Set the port FIFO timeout value. The @cflag value should
302 * reflect the actual hardware settings.
303 */
304void
305uart_update_timeout(struct uart_port *port, unsigned int cflag,
306 unsigned int baud)
307{
308 unsigned int bits;
309
310 /* byte size and parity */
311 switch (cflag & CSIZE) {
312 case CS5:
313 bits = 7;
314 break;
315 case CS6:
316 bits = 8;
317 break;
318 case CS7:
319 bits = 9;
320 break;
321 default:
322 bits = 10;
323 break; /* CS8 */
324 }
325
326 if (cflag & CSTOPB)
327 bits++;
328 if (cflag & PARENB)
329 bits++;
330
331 /*
332 * The total number of bits to be transmitted in the fifo.
333 */
334 bits = bits * port->fifosize;
335
336 /*
337 * Figure the timeout to send the above number of bits.
338 * Add .02 seconds of slop
339 */
340 port->timeout = (HZ * bits) / baud + HZ/50;
341}
342
343EXPORT_SYMBOL(uart_update_timeout);
344
345/**
346 * uart_get_baud_rate - return baud rate for a particular port
347 * @port: uart_port structure describing the port in question.
348 * @termios: desired termios settings.
349 * @old: old termios (or NULL)
350 * @min: minimum acceptable baud rate
351 * @max: maximum acceptable baud rate
352 *
353 * Decode the termios structure into a numeric baud rate,
354 * taking account of the magic 38400 baud rate (with spd_*
355 * flags), and mapping the %B0 rate to 9600 baud.
356 *
357 * If the new baud rate is invalid, try the old termios setting.
358 * If it's still invalid, we try 9600 baud.
359 *
360 * Update the @termios structure to reflect the baud rate
361 * we're actually going to be using. Don't do this for the case
362 * where B0 is requested ("hang up").
363 */
364unsigned int
365uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
366 struct ktermios *old, unsigned int min, unsigned int max)
367{
368 unsigned int try;
369 unsigned int baud;
370 unsigned int altbaud;
371 int hung_up = 0;
372 upf_t flags = port->flags & UPF_SPD_MASK;
373
374 switch (flags) {
375 case UPF_SPD_HI:
376 altbaud = 57600;
377 break;
378 case UPF_SPD_VHI:
379 altbaud = 115200;
380 break;
381 case UPF_SPD_SHI:
382 altbaud = 230400;
383 break;
384 case UPF_SPD_WARP:
385 altbaud = 460800;
386 break;
387 default:
388 altbaud = 38400;
389 break;
390 }
391
392 for (try = 0; try < 2; try++) {
393 baud = tty_termios_baud_rate(termios);
394
395 /*
396 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
397 * Die! Die! Die!
398 */
399 if (try == 0 && baud == 38400)
400 baud = altbaud;
401
402 /*
403 * Special case: B0 rate.
404 */
405 if (baud == 0) {
406 hung_up = 1;
407 baud = 9600;
408 }
409
410 if (baud >= min && baud <= max)
411 return baud;
412
413 /*
414 * Oops, the quotient was zero. Try again with
415 * the old baud rate if possible.
416 */
417 termios->c_cflag &= ~CBAUD;
418 if (old) {
419 baud = tty_termios_baud_rate(old);
420 if (!hung_up)
421 tty_termios_encode_baud_rate(termios,
422 baud, baud);
423 old = NULL;
424 continue;
425 }
426
427 /*
428 * As a last resort, if the range cannot be met then clip to
429 * the nearest chip supported rate.
430 */
431 if (!hung_up) {
432 if (baud <= min)
433 tty_termios_encode_baud_rate(termios,
434 min + 1, min + 1);
435 else
436 tty_termios_encode_baud_rate(termios,
437 max - 1, max - 1);
438 }
439 }
440 /* Should never happen */
441 WARN_ON(1);
442 return 0;
443}
444
445EXPORT_SYMBOL(uart_get_baud_rate);
446
447/**
448 * uart_get_divisor - return uart clock divisor
449 * @port: uart_port structure describing the port.
450 * @baud: desired baud rate
451 *
452 * Calculate the uart clock divisor for the port.
453 */
454unsigned int
455uart_get_divisor(struct uart_port *port, unsigned int baud)
456{
457 unsigned int quot;
458
459 /*
460 * Old custom speed handling.
461 */
462 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
463 quot = port->custom_divisor;
464 else
465 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
466
467 return quot;
468}
469
470EXPORT_SYMBOL(uart_get_divisor);
471
472/* Caller holds port mutex */
473static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
474 struct ktermios *old_termios)
475{
476 struct uart_port *uport = uart_port_check(state);
477 struct ktermios *termios;
478 int hw_stopped;
479
480 /*
481 * If we have no tty, termios, or the port does not exist,
482 * then we can't set the parameters for this port.
483 */
484 if (!tty || uport->type == PORT_UNKNOWN)
485 return;
486
487 termios = &tty->termios;
488 uport->ops->set_termios(uport, termios, old_termios);
489
490 /*
491 * Set modem status enables based on termios cflag
492 */
493 spin_lock_irq(&uport->lock);
494 if (termios->c_cflag & CRTSCTS)
495 uport->status |= UPSTAT_CTS_ENABLE;
496 else
497 uport->status &= ~UPSTAT_CTS_ENABLE;
498
499 if (termios->c_cflag & CLOCAL)
500 uport->status &= ~UPSTAT_DCD_ENABLE;
501 else
502 uport->status |= UPSTAT_DCD_ENABLE;
503
504 /* reset sw-assisted CTS flow control based on (possibly) new mode */
505 hw_stopped = uport->hw_stopped;
506 uport->hw_stopped = uart_softcts_mode(uport) &&
507 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
508 if (uport->hw_stopped) {
509 if (!hw_stopped)
510 uport->ops->stop_tx(uport);
511 } else {
512 if (hw_stopped)
513 __uart_start(tty);
514 }
515 spin_unlock_irq(&uport->lock);
516}
517
518static int uart_put_char(struct tty_struct *tty, unsigned char c)
519{
520 struct uart_state *state = tty->driver_data;
521 struct uart_port *port;
522 struct circ_buf *circ;
523 unsigned long flags;
524 int ret = 0;
525
526 circ = &state->xmit;
527 if (!circ->buf)
528 return 0;
529
530 port = uart_port_lock(state, flags);
531 if (port && uart_circ_chars_free(circ) != 0) {
532 circ->buf[circ->head] = c;
533 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
534 ret = 1;
535 }
536 uart_port_unlock(port, flags);
537 return ret;
538}
539
540static void uart_flush_chars(struct tty_struct *tty)
541{
542 uart_start(tty);
543}
544
545static int uart_write(struct tty_struct *tty,
546 const unsigned char *buf, int count)
547{
548 struct uart_state *state = tty->driver_data;
549 struct uart_port *port;
550 struct circ_buf *circ;
551 unsigned long flags;
552 int c, ret = 0;
553
554 /*
555 * This means you called this function _after_ the port was
556 * closed. No cookie for you.
557 */
558 if (!state) {
559 WARN_ON(1);
560 return -EL3HLT;
561 }
562
563 circ = &state->xmit;
564 if (!circ->buf)
565 return 0;
566
567 port = uart_port_lock(state, flags);
568 while (port) {
569 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
570 if (count < c)
571 c = count;
572 if (c <= 0)
573 break;
574 memcpy(circ->buf + circ->head, buf, c);
575 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
576 buf += c;
577 count -= c;
578 ret += c;
579 }
580
581 __uart_start(tty);
582 uart_port_unlock(port, flags);
583 return ret;
584}
585
586static int uart_write_room(struct tty_struct *tty)
587{
588 struct uart_state *state = tty->driver_data;
589 struct uart_port *port;
590 unsigned long flags;
591 int ret;
592
593 port = uart_port_lock(state, flags);
594 ret = uart_circ_chars_free(&state->xmit);
595 uart_port_unlock(port, flags);
596 return ret;
597}
598
599static int uart_chars_in_buffer(struct tty_struct *tty)
600{
601 struct uart_state *state = tty->driver_data;
602 struct uart_port *port;
603 unsigned long flags;
604 int ret;
605
606 port = uart_port_lock(state, flags);
607 ret = uart_circ_chars_pending(&state->xmit);
608 uart_port_unlock(port, flags);
609 return ret;
610}
611
612static void uart_flush_buffer(struct tty_struct *tty)
613{
614 struct uart_state *state = tty->driver_data;
615 struct uart_port *port;
616 unsigned long flags;
617
618 /*
619 * This means you called this function _after_ the port was
620 * closed. No cookie for you.
621 */
622 if (!state) {
623 WARN_ON(1);
624 return;
625 }
626
627 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
628
629 port = uart_port_lock(state, flags);
630 if (!port)
631 return;
632 uart_circ_clear(&state->xmit);
633 if (port->ops->flush_buffer)
634 port->ops->flush_buffer(port);
635 uart_port_unlock(port, flags);
636 tty_port_tty_wakeup(&state->port);
637}
638
639/*
640 * This function is used to send a high-priority XON/XOFF character to
641 * the device
642 */
643static void uart_send_xchar(struct tty_struct *tty, char ch)
644{
645 struct uart_state *state = tty->driver_data;
646 struct uart_port *port;
647 unsigned long flags;
648
649 port = uart_port_ref(state);
650 if (!port)
651 return;
652
653 if (port->ops->send_xchar)
654 port->ops->send_xchar(port, ch);
655 else {
656 spin_lock_irqsave(&port->lock, flags);
657 port->x_char = ch;
658 if (ch)
659 port->ops->start_tx(port);
660 spin_unlock_irqrestore(&port->lock, flags);
661 }
662 uart_port_deref(port);
663}
664
665static void uart_throttle(struct tty_struct *tty)
666{
667 struct uart_state *state = tty->driver_data;
668 struct uart_port *port;
669 upstat_t mask = 0;
670
671 port = uart_port_ref(state);
672 if (!port)
673 return;
674
675 if (I_IXOFF(tty))
676 mask |= UPSTAT_AUTOXOFF;
677 if (C_CRTSCTS(tty))
678 mask |= UPSTAT_AUTORTS;
679
680 if (port->status & mask) {
681 port->ops->throttle(port);
682 mask &= ~port->status;
683 }
684
685 if (mask & UPSTAT_AUTORTS)
686 uart_clear_mctrl(port, TIOCM_RTS);
687
688 if (mask & UPSTAT_AUTOXOFF)
689 uart_send_xchar(tty, STOP_CHAR(tty));
690
691 uart_port_deref(port);
692}
693
694static void uart_unthrottle(struct tty_struct *tty)
695{
696 struct uart_state *state = tty->driver_data;
697 struct uart_port *port;
698 upstat_t mask = 0;
699
700 port = uart_port_ref(state);
701 if (!port)
702 return;
703
704 if (I_IXOFF(tty))
705 mask |= UPSTAT_AUTOXOFF;
706 if (C_CRTSCTS(tty))
707 mask |= UPSTAT_AUTORTS;
708
709 if (port->status & mask) {
710 port->ops->unthrottle(port);
711 mask &= ~port->status;
712 }
713
714 if (mask & UPSTAT_AUTORTS)
715 uart_set_mctrl(port, TIOCM_RTS);
716
717 if (mask & UPSTAT_AUTOXOFF)
718 uart_send_xchar(tty, START_CHAR(tty));
719
720 uart_port_deref(port);
721}
722
723static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
724{
725 struct uart_state *state = container_of(port, struct uart_state, port);
726 struct uart_port *uport;
727 int ret = -ENODEV;
728
729 memset(retinfo, 0, sizeof(*retinfo));
730
731 /*
732 * Ensure the state we copy is consistent and no hardware changes
733 * occur as we go
734 */
735 mutex_lock(&port->mutex);
736 uport = uart_port_check(state);
737 if (!uport)
738 goto out;
739
740 retinfo->type = uport->type;
741 retinfo->line = uport->line;
742 retinfo->port = uport->iobase;
743 if (HIGH_BITS_OFFSET)
744 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
745 retinfo->irq = uport->irq;
746 retinfo->flags = uport->flags;
747 retinfo->xmit_fifo_size = uport->fifosize;
748 retinfo->baud_base = uport->uartclk / 16;
749 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
750 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
751 ASYNC_CLOSING_WAIT_NONE :
752 jiffies_to_msecs(port->closing_wait) / 10;
753 retinfo->custom_divisor = uport->custom_divisor;
754 retinfo->hub6 = uport->hub6;
755 retinfo->io_type = uport->iotype;
756 retinfo->iomem_reg_shift = uport->regshift;
757 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
758
759 ret = 0;
760out:
761 mutex_unlock(&port->mutex);
762 return ret;
763}
764
765static int uart_get_info_user(struct tty_port *port,
766 struct serial_struct __user *retinfo)
767{
768 struct serial_struct tmp;
769
770 if (uart_get_info(port, &tmp) < 0)
771 return -EIO;
772
773 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
774 return -EFAULT;
775 return 0;
776}
777
778static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
779 struct uart_state *state,
780 struct serial_struct *new_info)
781{
782 struct uart_port *uport = uart_port_check(state);
783 unsigned long new_port;
784 unsigned int change_irq, change_port, closing_wait;
785 unsigned int old_custom_divisor, close_delay;
786 upf_t old_flags, new_flags;
787 int retval = 0;
788
789 if (!uport)
790 return -EIO;
791
792 new_port = new_info->port;
793 if (HIGH_BITS_OFFSET)
794 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
795
796 new_info->irq = irq_canonicalize(new_info->irq);
797 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
798 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
799 ASYNC_CLOSING_WAIT_NONE :
800 msecs_to_jiffies(new_info->closing_wait * 10);
801
802
803 change_irq = !(uport->flags & UPF_FIXED_PORT)
804 && new_info->irq != uport->irq;
805
806 /*
807 * Since changing the 'type' of the port changes its resource
808 * allocations, we should treat type changes the same as
809 * IO port changes.
810 */
811 change_port = !(uport->flags & UPF_FIXED_PORT)
812 && (new_port != uport->iobase ||
813 (unsigned long)new_info->iomem_base != uport->mapbase ||
814 new_info->hub6 != uport->hub6 ||
815 new_info->io_type != uport->iotype ||
816 new_info->iomem_reg_shift != uport->regshift ||
817 new_info->type != uport->type);
818
819 old_flags = uport->flags;
820 new_flags = new_info->flags;
821 old_custom_divisor = uport->custom_divisor;
822
823 if (!capable(CAP_SYS_ADMIN)) {
824 retval = -EPERM;
825 if (change_irq || change_port ||
826 (new_info->baud_base != uport->uartclk / 16) ||
827 (close_delay != port->close_delay) ||
828 (closing_wait != port->closing_wait) ||
829 (new_info->xmit_fifo_size &&
830 new_info->xmit_fifo_size != uport->fifosize) ||
831 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
832 goto exit;
833 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
834 (new_flags & UPF_USR_MASK));
835 uport->custom_divisor = new_info->custom_divisor;
836 goto check_and_exit;
837 }
838
839 /*
840 * Ask the low level driver to verify the settings.
841 */
842 if (uport->ops->verify_port)
843 retval = uport->ops->verify_port(uport, new_info);
844
845 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
846 (new_info->baud_base < 9600))
847 retval = -EINVAL;
848
849 if (retval)
850 goto exit;
851
852 if (change_port || change_irq) {
853 retval = -EBUSY;
854
855 /*
856 * Make sure that we are the sole user of this port.
857 */
858 if (tty_port_users(port) > 1)
859 goto exit;
860
861 /*
862 * We need to shutdown the serial port at the old
863 * port/type/irq combination.
864 */
865 uart_shutdown(tty, state);
866 }
867
868 if (change_port) {
869 unsigned long old_iobase, old_mapbase;
870 unsigned int old_type, old_iotype, old_hub6, old_shift;
871
872 old_iobase = uport->iobase;
873 old_mapbase = uport->mapbase;
874 old_type = uport->type;
875 old_hub6 = uport->hub6;
876 old_iotype = uport->iotype;
877 old_shift = uport->regshift;
878
879 /*
880 * Free and release old regions
881 */
882 if (old_type != PORT_UNKNOWN && uport->ops->release_port)
883 uport->ops->release_port(uport);
884
885 uport->iobase = new_port;
886 uport->type = new_info->type;
887 uport->hub6 = new_info->hub6;
888 uport->iotype = new_info->io_type;
889 uport->regshift = new_info->iomem_reg_shift;
890 uport->mapbase = (unsigned long)new_info->iomem_base;
891
892 /*
893 * Claim and map the new regions
894 */
895 if (uport->type != PORT_UNKNOWN && uport->ops->request_port) {
896 retval = uport->ops->request_port(uport);
897 } else {
898 /* Always success - Jean II */
899 retval = 0;
900 }
901
902 /*
903 * If we fail to request resources for the
904 * new port, try to restore the old settings.
905 */
906 if (retval) {
907 uport->iobase = old_iobase;
908 uport->type = old_type;
909 uport->hub6 = old_hub6;
910 uport->iotype = old_iotype;
911 uport->regshift = old_shift;
912 uport->mapbase = old_mapbase;
913
914 if (old_type != PORT_UNKNOWN) {
915 retval = uport->ops->request_port(uport);
916 /*
917 * If we failed to restore the old settings,
918 * we fail like this.
919 */
920 if (retval)
921 uport->type = PORT_UNKNOWN;
922
923 /*
924 * We failed anyway.
925 */
926 retval = -EBUSY;
927 }
928
929 /* Added to return the correct error -Ram Gupta */
930 goto exit;
931 }
932 }
933
934 if (change_irq)
935 uport->irq = new_info->irq;
936 if (!(uport->flags & UPF_FIXED_PORT))
937 uport->uartclk = new_info->baud_base * 16;
938 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
939 (new_flags & UPF_CHANGE_MASK);
940 uport->custom_divisor = new_info->custom_divisor;
941 port->close_delay = close_delay;
942 port->closing_wait = closing_wait;
943 if (new_info->xmit_fifo_size)
944 uport->fifosize = new_info->xmit_fifo_size;
945 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
946
947 check_and_exit:
948 retval = 0;
949 if (uport->type == PORT_UNKNOWN)
950 goto exit;
951 if (tty_port_initialized(port)) {
952 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
953 old_custom_divisor != uport->custom_divisor) {
954 /*
955 * If they're setting up a custom divisor or speed,
956 * instead of clearing it, then bitch about it. No
957 * need to rate-limit; it's CAP_SYS_ADMIN only.
958 */
959 if (uport->flags & UPF_SPD_MASK) {
960 dev_notice(uport->dev,
961 "%s sets custom speed on %s. This is deprecated.\n",
962 current->comm,
963 tty_name(port->tty));
964 }
965 uart_change_speed(tty, state, NULL);
966 }
967 } else {
968 retval = uart_startup(tty, state, 1);
969 if (retval > 0)
970 retval = 0;
971 }
972 exit:
973 return retval;
974}
975
976static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
977 struct serial_struct __user *newinfo)
978{
979 struct serial_struct new_serial;
980 struct tty_port *port = &state->port;
981 int retval;
982
983 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
984 return -EFAULT;
985
986 /*
987 * This semaphore protects port->count. It is also
988 * very useful to prevent opens. Also, take the
989 * port configuration semaphore to make sure that a
990 * module insertion/removal doesn't change anything
991 * under us.
992 */
993 mutex_lock(&port->mutex);
994 retval = uart_set_info(tty, port, state, &new_serial);
995 mutex_unlock(&port->mutex);
996 return retval;
997}
998
999/**
1000 * uart_get_lsr_info - get line status register info
1001 * @tty: tty associated with the UART
1002 * @state: UART being queried
1003 * @value: returned modem value
1004 */
1005static int uart_get_lsr_info(struct tty_struct *tty,
1006 struct uart_state *state, unsigned int __user *value)
1007{
1008 struct uart_port *uport = uart_port_check(state);
1009 unsigned int result;
1010
1011 result = uport->ops->tx_empty(uport);
1012
1013 /*
1014 * If we're about to load something into the transmit
1015 * register, we'll pretend the transmitter isn't empty to
1016 * avoid a race condition (depending on when the transmit
1017 * interrupt happens).
1018 */
1019 if (uport->x_char ||
1020 ((uart_circ_chars_pending(&state->xmit) > 0) &&
1021 !uart_tx_stopped(uport)))
1022 result &= ~TIOCSER_TEMT;
1023
1024 return put_user(result, value);
1025}
1026
1027static int uart_tiocmget(struct tty_struct *tty)
1028{
1029 struct uart_state *state = tty->driver_data;
1030 struct tty_port *port = &state->port;
1031 struct uart_port *uport;
1032 int result = -EIO;
1033
1034 mutex_lock(&port->mutex);
1035 uport = uart_port_check(state);
1036 if (!uport)
1037 goto out;
1038
1039 if (!tty_io_error(tty)) {
1040 result = uport->mctrl;
1041 spin_lock_irq(&uport->lock);
1042 result |= uport->ops->get_mctrl(uport);
1043 spin_unlock_irq(&uport->lock);
1044 }
1045out:
1046 mutex_unlock(&port->mutex);
1047 return result;
1048}
1049
1050static int
1051uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
1052{
1053 struct uart_state *state = tty->driver_data;
1054 struct tty_port *port = &state->port;
1055 struct uart_port *uport;
1056 int ret = -EIO;
1057
1058 mutex_lock(&port->mutex);
1059 uport = uart_port_check(state);
1060 if (!uport)
1061 goto out;
1062
1063 if (!tty_io_error(tty)) {
1064 uart_update_mctrl(uport, set, clear);
1065 ret = 0;
1066 }
1067out:
1068 mutex_unlock(&port->mutex);
1069 return ret;
1070}
1071
1072static int uart_break_ctl(struct tty_struct *tty, int break_state)
1073{
1074 struct uart_state *state = tty->driver_data;
1075 struct tty_port *port = &state->port;
1076 struct uart_port *uport;
1077 int ret = -EIO;
1078
1079 mutex_lock(&port->mutex);
1080 uport = uart_port_check(state);
1081 if (!uport)
1082 goto out;
1083
1084 if (uport->type != PORT_UNKNOWN)
1085 uport->ops->break_ctl(uport, break_state);
1086 ret = 0;
1087out:
1088 mutex_unlock(&port->mutex);
1089 return ret;
1090}
1091
1092static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1093{
1094 struct tty_port *port = &state->port;
1095 struct uart_port *uport;
1096 int flags, ret;
1097
1098 if (!capable(CAP_SYS_ADMIN))
1099 return -EPERM;
1100
1101 /*
1102 * Take the per-port semaphore. This prevents count from
1103 * changing, and hence any extra opens of the port while
1104 * we're auto-configuring.
1105 */
1106 if (mutex_lock_interruptible(&port->mutex))
1107 return -ERESTARTSYS;
1108
1109 uport = uart_port_check(state);
1110 if (!uport) {
1111 ret = -EIO;
1112 goto out;
1113 }
1114
1115 ret = -EBUSY;
1116 if (tty_port_users(port) == 1) {
1117 uart_shutdown(tty, state);
1118
1119 /*
1120 * If we already have a port type configured,
1121 * we must release its resources.
1122 */
1123 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
1124 uport->ops->release_port(uport);
1125
1126 flags = UART_CONFIG_TYPE;
1127 if (uport->flags & UPF_AUTO_IRQ)
1128 flags |= UART_CONFIG_IRQ;
1129
1130 /*
1131 * This will claim the ports resources if
1132 * a port is found.
1133 */
1134 uport->ops->config_port(uport, flags);
1135
1136 ret = uart_startup(tty, state, 1);
1137 if (ret > 0)
1138 ret = 0;
1139 }
1140out:
1141 mutex_unlock(&port->mutex);
1142 return ret;
1143}
1144
1145static void uart_enable_ms(struct uart_port *uport)
1146{
1147 /*
1148 * Force modem status interrupts on
1149 */
1150 if (uport->ops->enable_ms)
1151 uport->ops->enable_ms(uport);
1152}
1153
1154/*
1155 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1156 * - mask passed in arg for lines of interest
1157 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1158 * Caller should use TIOCGICOUNT to see which one it was
1159 *
1160 * FIXME: This wants extracting into a common all driver implementation
1161 * of TIOCMWAIT using tty_port.
1162 */
1163static int uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1164{
1165 struct uart_port *uport;
1166 struct tty_port *port = &state->port;
1167 DECLARE_WAITQUEUE(wait, current);
1168 struct uart_icount cprev, cnow;
1169 int ret;
1170
1171 /*
1172 * note the counters on entry
1173 */
1174 uport = uart_port_ref(state);
1175 if (!uport)
1176 return -EIO;
1177 spin_lock_irq(&uport->lock);
1178 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1179 uart_enable_ms(uport);
1180 spin_unlock_irq(&uport->lock);
1181
1182 add_wait_queue(&port->delta_msr_wait, &wait);
1183 for (;;) {
1184 spin_lock_irq(&uport->lock);
1185 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1186 spin_unlock_irq(&uport->lock);
1187
1188 set_current_state(TASK_INTERRUPTIBLE);
1189
1190 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1191 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1192 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1193 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1194 ret = 0;
1195 break;
1196 }
1197
1198 schedule();
1199
1200 /* see if a signal did it */
1201 if (signal_pending(current)) {
1202 ret = -ERESTARTSYS;
1203 break;
1204 }
1205
1206 cprev = cnow;
1207 }
1208 __set_current_state(TASK_RUNNING);
1209 remove_wait_queue(&port->delta_msr_wait, &wait);
1210 uart_port_deref(uport);
1211
1212 return ret;
1213}
1214
1215/*
1216 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1217 * Return: write counters to the user passed counter struct
1218 * NB: both 1->0 and 0->1 transitions are counted except for
1219 * RI where only 0->1 is counted.
1220 */
1221static int uart_get_icount(struct tty_struct *tty,
1222 struct serial_icounter_struct *icount)
1223{
1224 struct uart_state *state = tty->driver_data;
1225 struct uart_icount cnow;
1226 struct uart_port *uport;
1227
1228 uport = uart_port_ref(state);
1229 if (!uport)
1230 return -EIO;
1231 spin_lock_irq(&uport->lock);
1232 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1233 spin_unlock_irq(&uport->lock);
1234 uart_port_deref(uport);
1235
1236 icount->cts = cnow.cts;
1237 icount->dsr = cnow.dsr;
1238 icount->rng = cnow.rng;
1239 icount->dcd = cnow.dcd;
1240 icount->rx = cnow.rx;
1241 icount->tx = cnow.tx;
1242 icount->frame = cnow.frame;
1243 icount->overrun = cnow.overrun;
1244 icount->parity = cnow.parity;
1245 icount->brk = cnow.brk;
1246 icount->buf_overrun = cnow.buf_overrun;
1247
1248 return 0;
1249}
1250
1251static int uart_get_rs485_config(struct uart_port *port,
1252 struct serial_rs485 __user *rs485)
1253{
1254 unsigned long flags;
1255 struct serial_rs485 aux;
1256
1257 spin_lock_irqsave(&port->lock, flags);
1258 aux = port->rs485;
1259 spin_unlock_irqrestore(&port->lock, flags);
1260
1261 if (copy_to_user(rs485, &aux, sizeof(aux)))
1262 return -EFAULT;
1263
1264 return 0;
1265}
1266
1267static int uart_set_rs485_config(struct uart_port *port,
1268 struct serial_rs485 __user *rs485_user)
1269{
1270 struct serial_rs485 rs485;
1271 int ret;
1272 unsigned long flags;
1273
1274 if (!port->rs485_config)
1275 return -ENOIOCTLCMD;
1276
1277 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1278 return -EFAULT;
1279
1280 spin_lock_irqsave(&port->lock, flags);
1281 ret = port->rs485_config(port, &rs485);
1282 spin_unlock_irqrestore(&port->lock, flags);
1283 if (ret)
1284 return ret;
1285
1286 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1287 return -EFAULT;
1288
1289 return 0;
1290}
1291
1292/*
1293 * Called via sys_ioctl. We can use spin_lock_irq() here.
1294 */
1295static int
1296uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
1297{
1298 struct uart_state *state = tty->driver_data;
1299 struct tty_port *port = &state->port;
1300 struct uart_port *uport;
1301 void __user *uarg = (void __user *)arg;
1302 int ret = -ENOIOCTLCMD;
1303
1304
1305 /*
1306 * These ioctls don't rely on the hardware to be present.
1307 */
1308 switch (cmd) {
1309 case TIOCGSERIAL:
1310 ret = uart_get_info_user(port, uarg);
1311 break;
1312
1313 case TIOCSSERIAL:
1314 down_write(&tty->termios_rwsem);
1315 ret = uart_set_info_user(tty, state, uarg);
1316 up_write(&tty->termios_rwsem);
1317 break;
1318
1319 case TIOCSERCONFIG:
1320 down_write(&tty->termios_rwsem);
1321 ret = uart_do_autoconfig(tty, state);
1322 up_write(&tty->termios_rwsem);
1323 break;
1324
1325 case TIOCSERGWILD: /* obsolete */
1326 case TIOCSERSWILD: /* obsolete */
1327 ret = 0;
1328 break;
1329 }
1330
1331 if (ret != -ENOIOCTLCMD)
1332 goto out;
1333
1334 if (tty_io_error(tty)) {
1335 ret = -EIO;
1336 goto out;
1337 }
1338
1339 /*
1340 * The following should only be used when hardware is present.
1341 */
1342 switch (cmd) {
1343 case TIOCMIWAIT:
1344 ret = uart_wait_modem_status(state, arg);
1345 break;
1346 }
1347
1348 if (ret != -ENOIOCTLCMD)
1349 goto out;
1350
1351 mutex_lock(&port->mutex);
1352 uport = uart_port_check(state);
1353
1354 if (!uport || tty_io_error(tty)) {
1355 ret = -EIO;
1356 goto out_up;
1357 }
1358
1359 /*
1360 * All these rely on hardware being present and need to be
1361 * protected against the tty being hung up.
1362 */
1363
1364 switch (cmd) {
1365 case TIOCSERGETLSR: /* Get line status register */
1366 ret = uart_get_lsr_info(tty, state, uarg);
1367 break;
1368
1369 case TIOCGRS485:
1370 ret = uart_get_rs485_config(uport, uarg);
1371 break;
1372
1373 case TIOCSRS485:
1374 ret = uart_set_rs485_config(uport, uarg);
1375 break;
1376 default:
1377 if (uport->ops->ioctl)
1378 ret = uport->ops->ioctl(uport, cmd, arg);
1379 break;
1380 }
1381out_up:
1382 mutex_unlock(&port->mutex);
1383out:
1384 return ret;
1385}
1386
1387static void uart_set_ldisc(struct tty_struct *tty)
1388{
1389 struct uart_state *state = tty->driver_data;
1390 struct uart_port *uport;
1391
1392 mutex_lock(&state->port.mutex);
1393 uport = uart_port_check(state);
1394 if (uport && uport->ops->set_ldisc)
1395 uport->ops->set_ldisc(uport, &tty->termios);
1396 mutex_unlock(&state->port.mutex);
1397}
1398
1399static void uart_set_termios(struct tty_struct *tty,
1400 struct ktermios *old_termios)
1401{
1402 struct uart_state *state = tty->driver_data;
1403 struct uart_port *uport;
1404 unsigned int cflag = tty->termios.c_cflag;
1405 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1406 bool sw_changed = false;
1407
1408 mutex_lock(&state->port.mutex);
1409 uport = uart_port_check(state);
1410 if (!uport)
1411 goto out;
1412
1413 /*
1414 * Drivers doing software flow control also need to know
1415 * about changes to these input settings.
1416 */
1417 if (uport->flags & UPF_SOFT_FLOW) {
1418 iflag_mask |= IXANY|IXON|IXOFF;
1419 sw_changed =
1420 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1421 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1422 }
1423
1424 /*
1425 * These are the bits that are used to setup various
1426 * flags in the low level driver. We can ignore the Bfoo
1427 * bits in c_cflag; c_[io]speed will always be set
1428 * appropriately by set_termios() in tty_ioctl.c
1429 */
1430 if ((cflag ^ old_termios->c_cflag) == 0 &&
1431 tty->termios.c_ospeed == old_termios->c_ospeed &&
1432 tty->termios.c_ispeed == old_termios->c_ispeed &&
1433 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1434 !sw_changed) {
1435 goto out;
1436 }
1437
1438 uart_change_speed(tty, state, old_termios);
1439 /* reload cflag from termios; port driver may have overriden flags */
1440 cflag = tty->termios.c_cflag;
1441
1442 /* Handle transition to B0 status */
1443 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1444 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1445 /* Handle transition away from B0 status */
1446 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1447 unsigned int mask = TIOCM_DTR;
1448 if (!(cflag & CRTSCTS) || !tty_throttled(tty))
1449 mask |= TIOCM_RTS;
1450 uart_set_mctrl(uport, mask);
1451 }
1452out:
1453 mutex_unlock(&state->port.mutex);
1454}
1455
1456/*
1457 * Calls to uart_close() are serialised via the tty_lock in
1458 * drivers/tty/tty_io.c:tty_release()
1459 * drivers/tty/tty_io.c:do_tty_hangup()
1460 */
1461static void uart_close(struct tty_struct *tty, struct file *filp)
1462{
1463 struct uart_state *state = tty->driver_data;
1464 struct tty_port *port;
1465
1466 if (!state) {
1467 struct uart_driver *drv = tty->driver->driver_state;
1468
1469 state = drv->state + tty->index;
1470 port = &state->port;
1471 spin_lock_irq(&port->lock);
1472 --port->count;
1473 spin_unlock_irq(&port->lock);
1474 return;
1475 }
1476
1477 port = &state->port;
1478 pr_debug("uart_close(%d) called\n", tty->index);
1479
1480 tty_port_close(tty->port, tty, filp);
1481}
1482
1483static void uart_tty_port_shutdown(struct tty_port *port)
1484{
1485 struct uart_state *state = container_of(port, struct uart_state, port);
1486 struct uart_port *uport = uart_port_check(state);
1487
1488 /*
1489 * At this point, we stop accepting input. To do this, we
1490 * disable the receive line status interrupts.
1491 */
1492 if (WARN(!uport, "detached port still initialized!\n"))
1493 return;
1494
1495 spin_lock_irq(&uport->lock);
1496 uport->ops->stop_rx(uport);
1497 spin_unlock_irq(&uport->lock);
1498
1499 uart_port_shutdown(port);
1500
1501 /*
1502 * It's possible for shutdown to be called after suspend if we get
1503 * a DCD drop (hangup) at just the right time. Clear suspended bit so
1504 * we don't try to resume a port that has been shutdown.
1505 */
1506 tty_port_set_suspended(port, 0);
1507
1508 uart_change_pm(state, UART_PM_STATE_OFF);
1509
1510}
1511
1512static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1513{
1514 struct uart_state *state = tty->driver_data;
1515 struct uart_port *port;
1516 unsigned long char_time, expire;
1517
1518 port = uart_port_ref(state);
1519 if (!port)
1520 return;
1521
1522 if (port->type == PORT_UNKNOWN || port->fifosize == 0) {
1523 uart_port_deref(port);
1524 return;
1525 }
1526
1527 /*
1528 * Set the check interval to be 1/5 of the estimated time to
1529 * send a single character, and make it at least 1. The check
1530 * interval should also be less than the timeout.
1531 *
1532 * Note: we have to use pretty tight timings here to satisfy
1533 * the NIST-PCTS.
1534 */
1535 char_time = (port->timeout - HZ/50) / port->fifosize;
1536 char_time = char_time / 5;
1537 if (char_time == 0)
1538 char_time = 1;
1539 if (timeout && timeout < char_time)
1540 char_time = timeout;
1541
1542 /*
1543 * If the transmitter hasn't cleared in twice the approximate
1544 * amount of time to send the entire FIFO, it probably won't
1545 * ever clear. This assumes the UART isn't doing flow
1546 * control, which is currently the case. Hence, if it ever
1547 * takes longer than port->timeout, this is probably due to a
1548 * UART bug of some kind. So, we clamp the timeout parameter at
1549 * 2*port->timeout.
1550 */
1551 if (timeout == 0 || timeout > 2 * port->timeout)
1552 timeout = 2 * port->timeout;
1553
1554 expire = jiffies + timeout;
1555
1556 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1557 port->line, jiffies, expire);
1558
1559 /*
1560 * Check whether the transmitter is empty every 'char_time'.
1561 * 'timeout' / 'expire' give us the maximum amount of time
1562 * we wait.
1563 */
1564 while (!port->ops->tx_empty(port)) {
1565 msleep_interruptible(jiffies_to_msecs(char_time));
1566 if (signal_pending(current))
1567 break;
1568 if (time_after(jiffies, expire))
1569 break;
1570 }
1571 uart_port_deref(port);
1572}
1573
1574/*
1575 * Calls to uart_hangup() are serialised by the tty_lock in
1576 * drivers/tty/tty_io.c:do_tty_hangup()
1577 * This runs from a workqueue and can sleep for a _short_ time only.
1578 */
1579static void uart_hangup(struct tty_struct *tty)
1580{
1581 struct uart_state *state = tty->driver_data;
1582 struct tty_port *port = &state->port;
1583 struct uart_port *uport;
1584 unsigned long flags;
1585
1586 pr_debug("uart_hangup(%d)\n", tty->index);
1587
1588 mutex_lock(&port->mutex);
1589 uport = uart_port_check(state);
1590 WARN(!uport, "hangup of detached port!\n");
1591
1592 if (tty_port_active(port)) {
1593 uart_flush_buffer(tty);
1594 uart_shutdown(tty, state);
1595 spin_lock_irqsave(&port->lock, flags);
1596 port->count = 0;
1597 spin_unlock_irqrestore(&port->lock, flags);
1598 tty_port_set_active(port, 0);
1599 tty_port_tty_set(port, NULL);
1600 if (uport && !uart_console(uport))
1601 uart_change_pm(state, UART_PM_STATE_OFF);
1602 wake_up_interruptible(&port->open_wait);
1603 wake_up_interruptible(&port->delta_msr_wait);
1604 }
1605 mutex_unlock(&port->mutex);
1606}
1607
1608/* uport == NULL if uart_port has already been removed */
1609static void uart_port_shutdown(struct tty_port *port)
1610{
1611 struct uart_state *state = container_of(port, struct uart_state, port);
1612 struct uart_port *uport = uart_port_check(state);
1613
1614 /*
1615 * clear delta_msr_wait queue to avoid mem leaks: we may free
1616 * the irq here so the queue might never be woken up. Note
1617 * that we won't end up waiting on delta_msr_wait again since
1618 * any outstanding file descriptors should be pointing at
1619 * hung_up_tty_fops now.
1620 */
1621 wake_up_interruptible(&port->delta_msr_wait);
1622
1623 /*
1624 * Free the IRQ and disable the port.
1625 */
1626 if (uport)
1627 uport->ops->shutdown(uport);
1628
1629 /*
1630 * Ensure that the IRQ handler isn't running on another CPU.
1631 */
1632 if (uport)
1633 synchronize_irq(uport->irq);
1634}
1635
1636static int uart_carrier_raised(struct tty_port *port)
1637{
1638 struct uart_state *state = container_of(port, struct uart_state, port);
1639 struct uart_port *uport;
1640 int mctrl;
1641
1642 uport = uart_port_ref(state);
1643 /*
1644 * Should never observe uport == NULL since checks for hangup should
1645 * abort the tty_port_block_til_ready() loop before checking for carrier
1646 * raised -- but report carrier raised if it does anyway so open will
1647 * continue and not sleep
1648 */
1649 if (WARN_ON(!uport))
1650 return 1;
1651 spin_lock_irq(&uport->lock);
1652 uart_enable_ms(uport);
1653 mctrl = uport->ops->get_mctrl(uport);
1654 spin_unlock_irq(&uport->lock);
1655 uart_port_deref(uport);
1656 if (mctrl & TIOCM_CAR)
1657 return 1;
1658 return 0;
1659}
1660
1661static void uart_dtr_rts(struct tty_port *port, int onoff)
1662{
1663 struct uart_state *state = container_of(port, struct uart_state, port);
1664 struct uart_port *uport;
1665
1666 uport = uart_port_ref(state);
1667 if (!uport)
1668 return;
1669
1670 if (onoff)
1671 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1672 else
1673 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1674
1675 uart_port_deref(uport);
1676}
1677
1678/*
1679 * Calls to uart_open are serialised by the tty_lock in
1680 * drivers/tty/tty_io.c:tty_open()
1681 * Note that if this fails, then uart_close() _will_ be called.
1682 *
1683 * In time, we want to scrap the "opening nonpresent ports"
1684 * behaviour and implement an alternative way for setserial
1685 * to set base addresses/ports/types. This will allow us to
1686 * get rid of a certain amount of extra tests.
1687 */
1688static int uart_open(struct tty_struct *tty, struct file *filp)
1689{
1690 struct uart_driver *drv = tty->driver->driver_state;
1691 int retval, line = tty->index;
1692 struct uart_state *state = drv->state + line;
1693
1694 tty->driver_data = state;
1695
1696 retval = tty_port_open(&state->port, tty, filp);
1697 if (retval > 0)
1698 retval = 0;
1699
1700 return retval;
1701}
1702
1703static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1704{
1705 struct uart_state *state = container_of(port, struct uart_state, port);
1706 struct uart_port *uport;
1707
1708 uport = uart_port_check(state);
1709 if (!uport || uport->flags & UPF_DEAD)
1710 return -ENXIO;
1711
1712 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
1713
1714 /*
1715 * Start up the serial port.
1716 */
1717 return uart_startup(tty, state, 0);
1718}
1719
1720static const char *uart_type(struct uart_port *port)
1721{
1722 const char *str = NULL;
1723
1724 if (port->ops->type)
1725 str = port->ops->type(port);
1726
1727 if (!str)
1728 str = "unknown";
1729
1730 return str;
1731}
1732
1733#ifdef CONFIG_PROC_FS
1734
1735static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1736{
1737 struct uart_state *state = drv->state + i;
1738 struct tty_port *port = &state->port;
1739 enum uart_pm_state pm_state;
1740 struct uart_port *uport;
1741 char stat_buf[32];
1742 unsigned int status;
1743 int mmio;
1744
1745 mutex_lock(&port->mutex);
1746 uport = uart_port_check(state);
1747 if (!uport)
1748 goto out;
1749
1750 mmio = uport->iotype >= UPIO_MEM;
1751 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1752 uport->line, uart_type(uport),
1753 mmio ? "mmio:0x" : "port:",
1754 mmio ? (unsigned long long)uport->mapbase
1755 : (unsigned long long)uport->iobase,
1756 uport->irq);
1757
1758 if (uport->type == PORT_UNKNOWN) {
1759 seq_putc(m, '\n');
1760 goto out;
1761 }
1762
1763 if (capable(CAP_SYS_ADMIN)) {
1764 pm_state = state->pm_state;
1765 if (pm_state != UART_PM_STATE_ON)
1766 uart_change_pm(state, UART_PM_STATE_ON);
1767 spin_lock_irq(&uport->lock);
1768 status = uport->ops->get_mctrl(uport);
1769 spin_unlock_irq(&uport->lock);
1770 if (pm_state != UART_PM_STATE_ON)
1771 uart_change_pm(state, pm_state);
1772
1773 seq_printf(m, " tx:%d rx:%d",
1774 uport->icount.tx, uport->icount.rx);
1775 if (uport->icount.frame)
1776 seq_printf(m, " fe:%d", uport->icount.frame);
1777 if (uport->icount.parity)
1778 seq_printf(m, " pe:%d", uport->icount.parity);
1779 if (uport->icount.brk)
1780 seq_printf(m, " brk:%d", uport->icount.brk);
1781 if (uport->icount.overrun)
1782 seq_printf(m, " oe:%d", uport->icount.overrun);
1783
1784#define INFOBIT(bit, str) \
1785 if (uport->mctrl & (bit)) \
1786 strncat(stat_buf, (str), sizeof(stat_buf) - \
1787 strlen(stat_buf) - 2)
1788#define STATBIT(bit, str) \
1789 if (status & (bit)) \
1790 strncat(stat_buf, (str), sizeof(stat_buf) - \
1791 strlen(stat_buf) - 2)
1792
1793 stat_buf[0] = '\0';
1794 stat_buf[1] = '\0';
1795 INFOBIT(TIOCM_RTS, "|RTS");
1796 STATBIT(TIOCM_CTS, "|CTS");
1797 INFOBIT(TIOCM_DTR, "|DTR");
1798 STATBIT(TIOCM_DSR, "|DSR");
1799 STATBIT(TIOCM_CAR, "|CD");
1800 STATBIT(TIOCM_RNG, "|RI");
1801 if (stat_buf[0])
1802 stat_buf[0] = ' ';
1803
1804 seq_puts(m, stat_buf);
1805 }
1806 seq_putc(m, '\n');
1807#undef STATBIT
1808#undef INFOBIT
1809out:
1810 mutex_unlock(&port->mutex);
1811}
1812
1813static int uart_proc_show(struct seq_file *m, void *v)
1814{
1815 struct tty_driver *ttydrv = m->private;
1816 struct uart_driver *drv = ttydrv->driver_state;
1817 int i;
1818
1819 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
1820 for (i = 0; i < drv->nr; i++)
1821 uart_line_info(m, drv, i);
1822 return 0;
1823}
1824
1825static int uart_proc_open(struct inode *inode, struct file *file)
1826{
1827 return single_open(file, uart_proc_show, PDE_DATA(inode));
1828}
1829
1830static const struct file_operations uart_proc_fops = {
1831 .owner = THIS_MODULE,
1832 .open = uart_proc_open,
1833 .read = seq_read,
1834 .llseek = seq_lseek,
1835 .release = single_release,
1836};
1837#endif
1838
1839#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1840/**
1841 * uart_console_write - write a console message to a serial port
1842 * @port: the port to write the message
1843 * @s: array of characters
1844 * @count: number of characters in string to write
1845 * @putchar: function to write character to port
1846 */
1847void uart_console_write(struct uart_port *port, const char *s,
1848 unsigned int count,
1849 void (*putchar)(struct uart_port *, int))
1850{
1851 unsigned int i;
1852
1853 for (i = 0; i < count; i++, s++) {
1854 if (*s == '\n')
1855 putchar(port, '\r');
1856 putchar(port, *s);
1857 }
1858}
1859EXPORT_SYMBOL_GPL(uart_console_write);
1860
1861/*
1862 * Check whether an invalid uart number has been specified, and
1863 * if so, search for the first available port that does have
1864 * console support.
1865 */
1866struct uart_port * __init
1867uart_get_console(struct uart_port *ports, int nr, struct console *co)
1868{
1869 int idx = co->index;
1870
1871 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1872 ports[idx].membase == NULL))
1873 for (idx = 0; idx < nr; idx++)
1874 if (ports[idx].iobase != 0 ||
1875 ports[idx].membase != NULL)
1876 break;
1877
1878 co->index = idx;
1879
1880 return ports + idx;
1881}
1882
1883/**
1884 * uart_parse_earlycon - Parse earlycon options
1885 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1886 * @iotype: ptr for decoded iotype (out)
1887 * @addr: ptr for decoded mapbase/iobase (out)
1888 * @options: ptr for <options> field; NULL if not present (out)
1889 *
1890 * Decodes earlycon kernel command line parameters of the form
1891 * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1892 * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1893 *
1894 * The optional form
1895 * earlycon=<name>,0x<addr>,<options>
1896 * console=<name>,0x<addr>,<options>
1897 * is also accepted; the returned @iotype will be UPIO_MEM.
1898 *
1899 * Returns 0 on success or -EINVAL on failure
1900 */
1901int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
1902 char **options)
1903{
1904 if (strncmp(p, "mmio,", 5) == 0) {
1905 *iotype = UPIO_MEM;
1906 p += 5;
1907 } else if (strncmp(p, "mmio16,", 7) == 0) {
1908 *iotype = UPIO_MEM16;
1909 p += 7;
1910 } else if (strncmp(p, "mmio32,", 7) == 0) {
1911 *iotype = UPIO_MEM32;
1912 p += 7;
1913 } else if (strncmp(p, "mmio32be,", 9) == 0) {
1914 *iotype = UPIO_MEM32BE;
1915 p += 9;
1916 } else if (strncmp(p, "mmio32native,", 13) == 0) {
1917 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
1918 UPIO_MEM32BE : UPIO_MEM32;
1919 p += 13;
1920 } else if (strncmp(p, "io,", 3) == 0) {
1921 *iotype = UPIO_PORT;
1922 p += 3;
1923 } else if (strncmp(p, "0x", 2) == 0) {
1924 *iotype = UPIO_MEM;
1925 } else {
1926 return -EINVAL;
1927 }
1928
1929 /*
1930 * Before you replace it with kstrtoull(), think about options separator
1931 * (',') it will not tolerate
1932 */
1933 *addr = simple_strtoull(p, NULL, 0);
1934 p = strchr(p, ',');
1935 if (p)
1936 p++;
1937
1938 *options = p;
1939 return 0;
1940}
1941EXPORT_SYMBOL_GPL(uart_parse_earlycon);
1942
1943/**
1944 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1945 * @options: pointer to option string
1946 * @baud: pointer to an 'int' variable for the baud rate.
1947 * @parity: pointer to an 'int' variable for the parity.
1948 * @bits: pointer to an 'int' variable for the number of data bits.
1949 * @flow: pointer to an 'int' variable for the flow control character.
1950 *
1951 * uart_parse_options decodes a string containing the serial console
1952 * options. The format of the string is <baud><parity><bits><flow>,
1953 * eg: 115200n8r
1954 */
1955void
1956uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1957{
1958 char *s = options;
1959
1960 *baud = simple_strtoul(s, NULL, 10);
1961 while (*s >= '0' && *s <= '9')
1962 s++;
1963 if (*s)
1964 *parity = *s++;
1965 if (*s)
1966 *bits = *s++ - '0';
1967 if (*s)
1968 *flow = *s;
1969}
1970EXPORT_SYMBOL_GPL(uart_parse_options);
1971
1972/**
1973 * uart_set_options - setup the serial console parameters
1974 * @port: pointer to the serial ports uart_port structure
1975 * @co: console pointer
1976 * @baud: baud rate
1977 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1978 * @bits: number of data bits
1979 * @flow: flow control character - 'r' (rts)
1980 */
1981int
1982uart_set_options(struct uart_port *port, struct console *co,
1983 int baud, int parity, int bits, int flow)
1984{
1985 struct ktermios termios;
1986 static struct ktermios dummy;
1987
1988 /*
1989 * Ensure that the serial console lock is initialised
1990 * early.
1991 * If this port is a console, then the spinlock is already
1992 * initialised.
1993 */
1994 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1995 spin_lock_init(&port->lock);
1996 lockdep_set_class(&port->lock, &port_lock_key);
1997 }
1998
1999 memset(&termios, 0, sizeof(struct ktermios));
2000
2001 termios.c_cflag |= CREAD | HUPCL | CLOCAL;
2002 tty_termios_encode_baud_rate(&termios, baud, baud);
2003
2004 if (bits == 7)
2005 termios.c_cflag |= CS7;
2006 else
2007 termios.c_cflag |= CS8;
2008
2009 switch (parity) {
2010 case 'o': case 'O':
2011 termios.c_cflag |= PARODD;
2012 /*fall through*/
2013 case 'e': case 'E':
2014 termios.c_cflag |= PARENB;
2015 break;
2016 }
2017
2018 if (flow == 'r')
2019 termios.c_cflag |= CRTSCTS;
2020
2021 /*
2022 * some uarts on other side don't support no flow control.
2023 * So we set * DTR in host uart to make them happy
2024 */
2025 port->mctrl |= TIOCM_DTR;
2026
2027 port->ops->set_termios(port, &termios, &dummy);
2028 /*
2029 * Allow the setting of the UART parameters with a NULL console
2030 * too:
2031 */
2032 if (co)
2033 co->cflag = termios.c_cflag;
2034
2035 return 0;
2036}
2037EXPORT_SYMBOL_GPL(uart_set_options);
2038#endif /* CONFIG_SERIAL_CORE_CONSOLE */
2039
2040/**
2041 * uart_change_pm - set power state of the port
2042 *
2043 * @state: port descriptor
2044 * @pm_state: new state
2045 *
2046 * Locking: port->mutex has to be held
2047 */
2048static void uart_change_pm(struct uart_state *state,
2049 enum uart_pm_state pm_state)
2050{
2051 struct uart_port *port = uart_port_check(state);
2052
2053 if (state->pm_state != pm_state) {
2054 if (port && port->ops->pm)
2055 port->ops->pm(port, pm_state, state->pm_state);
2056 state->pm_state = pm_state;
2057 }
2058}
2059
2060struct uart_match {
2061 struct uart_port *port;
2062 struct uart_driver *driver;
2063};
2064
2065static int serial_match_port(struct device *dev, void *data)
2066{
2067 struct uart_match *match = data;
2068 struct tty_driver *tty_drv = match->driver->tty_driver;
2069 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
2070 match->port->line;
2071
2072 return dev->devt == devt; /* Actually, only one tty per port */
2073}
2074
2075int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
2076{
2077 struct uart_state *state = drv->state + uport->line;
2078 struct tty_port *port = &state->port;
2079 struct device *tty_dev;
2080 struct uart_match match = {uport, drv};
2081
2082 mutex_lock(&port->mutex);
2083
2084 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2085 if (device_may_wakeup(tty_dev)) {
2086 if (!enable_irq_wake(uport->irq))
2087 uport->irq_wake = 1;
2088 put_device(tty_dev);
2089 mutex_unlock(&port->mutex);
2090 return 0;
2091 }
2092 put_device(tty_dev);
2093
2094 /* Nothing to do if the console is not suspending */
2095 if (!console_suspend_enabled && uart_console(uport))
2096 goto unlock;
2097
2098 uport->suspended = 1;
2099
2100 if (tty_port_initialized(port)) {
2101 const struct uart_ops *ops = uport->ops;
2102 int tries;
2103
2104 tty_port_set_suspended(port, 1);
2105 tty_port_set_initialized(port, 0);
2106
2107 spin_lock_irq(&uport->lock);
2108 ops->stop_tx(uport);
2109 ops->set_mctrl(uport, 0);
2110 ops->stop_rx(uport);
2111 spin_unlock_irq(&uport->lock);
2112
2113 /*
2114 * Wait for the transmitter to empty.
2115 */
2116 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2117 msleep(10);
2118 if (!tries)
2119 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
2120 drv->dev_name,
2121 drv->tty_driver->name_base + uport->line);
2122
2123 ops->shutdown(uport);
2124 }
2125
2126 /*
2127 * Disable the console device before suspending.
2128 */
2129 if (uart_console(uport))
2130 console_stop(uport->cons);
2131
2132 uart_change_pm(state, UART_PM_STATE_OFF);
2133unlock:
2134 mutex_unlock(&port->mutex);
2135
2136 return 0;
2137}
2138
2139int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2140{
2141 struct uart_state *state = drv->state + uport->line;
2142 struct tty_port *port = &state->port;
2143 struct device *tty_dev;
2144 struct uart_match match = {uport, drv};
2145 struct ktermios termios;
2146
2147 mutex_lock(&port->mutex);
2148
2149 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2150 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2151 if (uport->irq_wake) {
2152 disable_irq_wake(uport->irq);
2153 uport->irq_wake = 0;
2154 }
2155 put_device(tty_dev);
2156 mutex_unlock(&port->mutex);
2157 return 0;
2158 }
2159 put_device(tty_dev);
2160 uport->suspended = 0;
2161
2162 /*
2163 * Re-enable the console device after suspending.
2164 */
2165 if (uart_console(uport)) {
2166 /*
2167 * First try to use the console cflag setting.
2168 */
2169 memset(&termios, 0, sizeof(struct ktermios));
2170 termios.c_cflag = uport->cons->cflag;
2171
2172 /*
2173 * If that's unset, use the tty termios setting.
2174 */
2175 if (port->tty && termios.c_cflag == 0)
2176 termios = port->tty->termios;
2177
2178 if (console_suspend_enabled)
2179 uart_change_pm(state, UART_PM_STATE_ON);
2180 uport->ops->set_termios(uport, &termios, NULL);
2181 if (console_suspend_enabled)
2182 console_start(uport->cons);
2183 }
2184
2185 if (tty_port_suspended(port)) {
2186 const struct uart_ops *ops = uport->ops;
2187 int ret;
2188
2189 uart_change_pm(state, UART_PM_STATE_ON);
2190 spin_lock_irq(&uport->lock);
2191 ops->set_mctrl(uport, 0);
2192 spin_unlock_irq(&uport->lock);
2193 if (console_suspend_enabled || !uart_console(uport)) {
2194 /* Protected by port mutex for now */
2195 struct tty_struct *tty = port->tty;
2196 ret = ops->startup(uport);
2197 if (ret == 0) {
2198 if (tty)
2199 uart_change_speed(tty, state, NULL);
2200 spin_lock_irq(&uport->lock);
2201 ops->set_mctrl(uport, uport->mctrl);
2202 ops->start_tx(uport);
2203 spin_unlock_irq(&uport->lock);
2204 tty_port_set_initialized(port, 1);
2205 } else {
2206 /*
2207 * Failed to resume - maybe hardware went away?
2208 * Clear the "initialized" flag so we won't try
2209 * to call the low level drivers shutdown method.
2210 */
2211 uart_shutdown(tty, state);
2212 }
2213 }
2214
2215 tty_port_set_suspended(port, 0);
2216 }
2217
2218 mutex_unlock(&port->mutex);
2219
2220 return 0;
2221}
2222
2223static inline void
2224uart_report_port(struct uart_driver *drv, struct uart_port *port)
2225{
2226 char address[64];
2227
2228 switch (port->iotype) {
2229 case UPIO_PORT:
2230 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2231 break;
2232 case UPIO_HUB6:
2233 snprintf(address, sizeof(address),
2234 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2235 break;
2236 case UPIO_MEM:
2237 case UPIO_MEM16:
2238 case UPIO_MEM32:
2239 case UPIO_MEM32BE:
2240 case UPIO_AU:
2241 case UPIO_TSI:
2242 snprintf(address, sizeof(address),
2243 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2244 break;
2245 default:
2246 strlcpy(address, "*unknown*", sizeof(address));
2247 break;
2248 }
2249
2250 printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2251 port->dev ? dev_name(port->dev) : "",
2252 port->dev ? ": " : "",
2253 drv->dev_name,
2254 drv->tty_driver->name_base + port->line,
2255 address, port->irq, port->uartclk / 16, uart_type(port));
2256}
2257
2258static void
2259uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2260 struct uart_port *port)
2261{
2262 unsigned int flags;
2263
2264 /*
2265 * If there isn't a port here, don't do anything further.
2266 */
2267 if (!port->iobase && !port->mapbase && !port->membase)
2268 return;
2269
2270 /*
2271 * Now do the auto configuration stuff. Note that config_port
2272 * is expected to claim the resources and map the port for us.
2273 */
2274 flags = 0;
2275 if (port->flags & UPF_AUTO_IRQ)
2276 flags |= UART_CONFIG_IRQ;
2277 if (port->flags & UPF_BOOT_AUTOCONF) {
2278 if (!(port->flags & UPF_FIXED_TYPE)) {
2279 port->type = PORT_UNKNOWN;
2280 flags |= UART_CONFIG_TYPE;
2281 }
2282 port->ops->config_port(port, flags);
2283 }
2284
2285 if (port->type != PORT_UNKNOWN) {
2286 unsigned long flags;
2287
2288 uart_report_port(drv, port);
2289
2290 /* Power up port for set_mctrl() */
2291 uart_change_pm(state, UART_PM_STATE_ON);
2292
2293 /*
2294 * Ensure that the modem control lines are de-activated.
2295 * keep the DTR setting that is set in uart_set_options()
2296 * We probably don't need a spinlock around this, but
2297 */
2298 spin_lock_irqsave(&port->lock, flags);
2299 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2300 spin_unlock_irqrestore(&port->lock, flags);
2301
2302 /*
2303 * If this driver supports console, and it hasn't been
2304 * successfully registered yet, try to re-register it.
2305 * It may be that the port was not available.
2306 */
2307 if (port->cons && !(port->cons->flags & CON_ENABLED))
2308 register_console(port->cons);
2309
2310 /*
2311 * Power down all ports by default, except the
2312 * console if we have one.
2313 */
2314 if (!uart_console(port))
2315 uart_change_pm(state, UART_PM_STATE_OFF);
2316 }
2317}
2318
2319#ifdef CONFIG_CONSOLE_POLL
2320
2321static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2322{
2323 struct uart_driver *drv = driver->driver_state;
2324 struct uart_state *state = drv->state + line;
2325 struct tty_port *tport;
2326 struct uart_port *port;
2327 int baud = 9600;
2328 int bits = 8;
2329 int parity = 'n';
2330 int flow = 'n';
2331 int ret = 0;
2332
2333 if (!state)
2334 return -1;
2335
2336 tport = &state->port;
2337 mutex_lock(&tport->mutex);
2338
2339 port = uart_port_check(state);
2340 if (!port || !(port->ops->poll_get_char && port->ops->poll_put_char)) {
2341 ret = -1;
2342 goto out;
2343 }
2344
2345 if (port->ops->poll_init) {
2346 /*
2347 * We don't set initialized as we only initialized the hw,
2348 * e.g. state->xmit is still uninitialized.
2349 */
2350 if (!tty_port_initialized(tport))
2351 ret = port->ops->poll_init(port);
2352 }
2353
2354 if (!ret && options) {
2355 uart_parse_options(options, &baud, &parity, &bits, &flow);
2356 ret = uart_set_options(port, NULL, baud, parity, bits, flow);
2357 }
2358out:
2359 mutex_unlock(&tport->mutex);
2360 return ret;
2361}
2362
2363static int uart_poll_get_char(struct tty_driver *driver, int line)
2364{
2365 struct uart_driver *drv = driver->driver_state;
2366 struct uart_state *state = drv->state + line;
2367 struct uart_port *port;
2368 int ret = -1;
2369
2370 if (state) {
2371 port = uart_port_ref(state);
2372 if (port) {
2373 ret = port->ops->poll_get_char(port);
2374 uart_port_deref(port);
2375 }
2376 }
2377 return ret;
2378}
2379
2380static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2381{
2382 struct uart_driver *drv = driver->driver_state;
2383 struct uart_state *state = drv->state + line;
2384 struct uart_port *port;
2385
2386 if (!state)
2387 return;
2388
2389 port = uart_port_ref(state);
2390 if (!port)
2391 return;
2392
2393 if (ch == '\n')
2394 port->ops->poll_put_char(port, '\r');
2395 port->ops->poll_put_char(port, ch);
2396 uart_port_deref(port);
2397}
2398#endif
2399
2400static const struct tty_operations uart_ops = {
2401 .open = uart_open,
2402 .close = uart_close,
2403 .write = uart_write,
2404 .put_char = uart_put_char,
2405 .flush_chars = uart_flush_chars,
2406 .write_room = uart_write_room,
2407 .chars_in_buffer= uart_chars_in_buffer,
2408 .flush_buffer = uart_flush_buffer,
2409 .ioctl = uart_ioctl,
2410 .throttle = uart_throttle,
2411 .unthrottle = uart_unthrottle,
2412 .send_xchar = uart_send_xchar,
2413 .set_termios = uart_set_termios,
2414 .set_ldisc = uart_set_ldisc,
2415 .stop = uart_stop,
2416 .start = uart_start,
2417 .hangup = uart_hangup,
2418 .break_ctl = uart_break_ctl,
2419 .wait_until_sent= uart_wait_until_sent,
2420#ifdef CONFIG_PROC_FS
2421 .proc_fops = &uart_proc_fops,
2422#endif
2423 .tiocmget = uart_tiocmget,
2424 .tiocmset = uart_tiocmset,
2425 .get_icount = uart_get_icount,
2426#ifdef CONFIG_CONSOLE_POLL
2427 .poll_init = uart_poll_init,
2428 .poll_get_char = uart_poll_get_char,
2429 .poll_put_char = uart_poll_put_char,
2430#endif
2431};
2432
2433static const struct tty_port_operations uart_port_ops = {
2434 .carrier_raised = uart_carrier_raised,
2435 .dtr_rts = uart_dtr_rts,
2436 .activate = uart_port_activate,
2437 .shutdown = uart_tty_port_shutdown,
2438};
2439
2440/**
2441 * uart_register_driver - register a driver with the uart core layer
2442 * @drv: low level driver structure
2443 *
2444 * Register a uart driver with the core driver. We in turn register
2445 * with the tty layer, and initialise the core driver per-port state.
2446 *
2447 * We have a proc file in /proc/tty/driver which is named after the
2448 * normal driver.
2449 *
2450 * drv->port should be NULL, and the per-port structures should be
2451 * registered using uart_add_one_port after this call has succeeded.
2452 */
2453int uart_register_driver(struct uart_driver *drv)
2454{
2455 struct tty_driver *normal;
2456 int i, retval;
2457
2458 BUG_ON(drv->state);
2459
2460 /*
2461 * Maybe we should be using a slab cache for this, especially if
2462 * we have a large number of ports to handle.
2463 */
2464 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2465 if (!drv->state)
2466 goto out;
2467
2468 normal = alloc_tty_driver(drv->nr);
2469 if (!normal)
2470 goto out_kfree;
2471
2472 drv->tty_driver = normal;
2473
2474 normal->driver_name = drv->driver_name;
2475 normal->name = drv->dev_name;
2476 normal->major = drv->major;
2477 normal->minor_start = drv->minor;
2478 normal->type = TTY_DRIVER_TYPE_SERIAL;
2479 normal->subtype = SERIAL_TYPE_NORMAL;
2480 normal->init_termios = tty_std_termios;
2481 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2482 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2483 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2484 normal->driver_state = drv;
2485 tty_set_operations(normal, &uart_ops);
2486
2487 /*
2488 * Initialise the UART state(s).
2489 */
2490 for (i = 0; i < drv->nr; i++) {
2491 struct uart_state *state = drv->state + i;
2492 struct tty_port *port = &state->port;
2493
2494 tty_port_init(port);
2495 port->ops = &uart_port_ops;
2496 }
2497
2498 retval = tty_register_driver(normal);
2499 if (retval >= 0)
2500 return retval;
2501
2502 for (i = 0; i < drv->nr; i++)
2503 tty_port_destroy(&drv->state[i].port);
2504 put_tty_driver(normal);
2505out_kfree:
2506 kfree(drv->state);
2507out:
2508 return -ENOMEM;
2509}
2510
2511/**
2512 * uart_unregister_driver - remove a driver from the uart core layer
2513 * @drv: low level driver structure
2514 *
2515 * Remove all references to a driver from the core driver. The low
2516 * level driver must have removed all its ports via the
2517 * uart_remove_one_port() if it registered them with uart_add_one_port().
2518 * (ie, drv->port == NULL)
2519 */
2520void uart_unregister_driver(struct uart_driver *drv)
2521{
2522 struct tty_driver *p = drv->tty_driver;
2523 unsigned int i;
2524
2525 tty_unregister_driver(p);
2526 put_tty_driver(p);
2527 for (i = 0; i < drv->nr; i++)
2528 tty_port_destroy(&drv->state[i].port);
2529 kfree(drv->state);
2530 drv->state = NULL;
2531 drv->tty_driver = NULL;
2532}
2533
2534struct tty_driver *uart_console_device(struct console *co, int *index)
2535{
2536 struct uart_driver *p = co->data;
2537 *index = co->index;
2538 return p->tty_driver;
2539}
2540
2541static ssize_t uart_get_attr_uartclk(struct device *dev,
2542 struct device_attribute *attr, char *buf)
2543{
2544 struct serial_struct tmp;
2545 struct tty_port *port = dev_get_drvdata(dev);
2546
2547 uart_get_info(port, &tmp);
2548 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2549}
2550
2551static ssize_t uart_get_attr_type(struct device *dev,
2552 struct device_attribute *attr, char *buf)
2553{
2554 struct serial_struct tmp;
2555 struct tty_port *port = dev_get_drvdata(dev);
2556
2557 uart_get_info(port, &tmp);
2558 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2559}
2560static ssize_t uart_get_attr_line(struct device *dev,
2561 struct device_attribute *attr, char *buf)
2562{
2563 struct serial_struct tmp;
2564 struct tty_port *port = dev_get_drvdata(dev);
2565
2566 uart_get_info(port, &tmp);
2567 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2568}
2569
2570static ssize_t uart_get_attr_port(struct device *dev,
2571 struct device_attribute *attr, char *buf)
2572{
2573 struct serial_struct tmp;
2574 struct tty_port *port = dev_get_drvdata(dev);
2575 unsigned long ioaddr;
2576
2577 uart_get_info(port, &tmp);
2578 ioaddr = tmp.port;
2579 if (HIGH_BITS_OFFSET)
2580 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2581 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2582}
2583
2584static ssize_t uart_get_attr_irq(struct device *dev,
2585 struct device_attribute *attr, char *buf)
2586{
2587 struct serial_struct tmp;
2588 struct tty_port *port = dev_get_drvdata(dev);
2589
2590 uart_get_info(port, &tmp);
2591 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2592}
2593
2594static ssize_t uart_get_attr_flags(struct device *dev,
2595 struct device_attribute *attr, char *buf)
2596{
2597 struct serial_struct tmp;
2598 struct tty_port *port = dev_get_drvdata(dev);
2599
2600 uart_get_info(port, &tmp);
2601 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2602}
2603
2604static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2605 struct device_attribute *attr, char *buf)
2606{
2607 struct serial_struct tmp;
2608 struct tty_port *port = dev_get_drvdata(dev);
2609
2610 uart_get_info(port, &tmp);
2611 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2612}
2613
2614
2615static ssize_t uart_get_attr_close_delay(struct device *dev,
2616 struct device_attribute *attr, char *buf)
2617{
2618 struct serial_struct tmp;
2619 struct tty_port *port = dev_get_drvdata(dev);
2620
2621 uart_get_info(port, &tmp);
2622 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2623}
2624
2625
2626static ssize_t uart_get_attr_closing_wait(struct device *dev,
2627 struct device_attribute *attr, char *buf)
2628{
2629 struct serial_struct tmp;
2630 struct tty_port *port = dev_get_drvdata(dev);
2631
2632 uart_get_info(port, &tmp);
2633 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2634}
2635
2636static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2637 struct device_attribute *attr, char *buf)
2638{
2639 struct serial_struct tmp;
2640 struct tty_port *port = dev_get_drvdata(dev);
2641
2642 uart_get_info(port, &tmp);
2643 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2644}
2645
2646static ssize_t uart_get_attr_io_type(struct device *dev,
2647 struct device_attribute *attr, char *buf)
2648{
2649 struct serial_struct tmp;
2650 struct tty_port *port = dev_get_drvdata(dev);
2651
2652 uart_get_info(port, &tmp);
2653 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2654}
2655
2656static ssize_t uart_get_attr_iomem_base(struct device *dev,
2657 struct device_attribute *attr, char *buf)
2658{
2659 struct serial_struct tmp;
2660 struct tty_port *port = dev_get_drvdata(dev);
2661
2662 uart_get_info(port, &tmp);
2663 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2664}
2665
2666static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2667 struct device_attribute *attr, char *buf)
2668{
2669 struct serial_struct tmp;
2670 struct tty_port *port = dev_get_drvdata(dev);
2671
2672 uart_get_info(port, &tmp);
2673 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2674}
2675
2676static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2677static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2678static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2679static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2680static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2681static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2682static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2683static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2684static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2685static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2686static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2687static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2688static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2689
2690static struct attribute *tty_dev_attrs[] = {
2691 &dev_attr_type.attr,
2692 &dev_attr_line.attr,
2693 &dev_attr_port.attr,
2694 &dev_attr_irq.attr,
2695 &dev_attr_flags.attr,
2696 &dev_attr_xmit_fifo_size.attr,
2697 &dev_attr_uartclk.attr,
2698 &dev_attr_close_delay.attr,
2699 &dev_attr_closing_wait.attr,
2700 &dev_attr_custom_divisor.attr,
2701 &dev_attr_io_type.attr,
2702 &dev_attr_iomem_base.attr,
2703 &dev_attr_iomem_reg_shift.attr,
2704 NULL,
2705 };
2706
2707static const struct attribute_group tty_dev_attr_group = {
2708 .attrs = tty_dev_attrs,
2709 };
2710
2711/**
2712 * uart_add_one_port - attach a driver-defined port structure
2713 * @drv: pointer to the uart low level driver structure for this port
2714 * @uport: uart port structure to use for this port.
2715 *
2716 * This allows the driver to register its own uart_port structure
2717 * with the core driver. The main purpose is to allow the low
2718 * level uart drivers to expand uart_port, rather than having yet
2719 * more levels of structures.
2720 */
2721int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2722{
2723 struct uart_state *state;
2724 struct tty_port *port;
2725 int ret = 0;
2726 struct device *tty_dev;
2727 int num_groups;
2728
2729 BUG_ON(in_interrupt());
2730
2731 if (uport->line >= drv->nr)
2732 return -EINVAL;
2733
2734 state = drv->state + uport->line;
2735 port = &state->port;
2736
2737 mutex_lock(&port_mutex);
2738 mutex_lock(&port->mutex);
2739 if (state->uart_port) {
2740 ret = -EINVAL;
2741 goto out;
2742 }
2743
2744 /* Link the port to the driver state table and vice versa */
2745 atomic_set(&state->refcount, 1);
2746 init_waitqueue_head(&state->remove_wait);
2747 state->uart_port = uport;
2748 uport->state = state;
2749
2750 state->pm_state = UART_PM_STATE_UNDEFINED;
2751 uport->cons = drv->cons;
2752 uport->minor = drv->tty_driver->minor_start + uport->line;
2753
2754 /*
2755 * If this port is a console, then the spinlock is already
2756 * initialised.
2757 */
2758 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2759 spin_lock_init(&uport->lock);
2760 lockdep_set_class(&uport->lock, &port_lock_key);
2761 }
2762 if (uport->cons && uport->dev)
2763 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2764
2765 uart_configure_port(drv, state, uport);
2766
2767 port->console = uart_console(uport);
2768
2769 num_groups = 2;
2770 if (uport->attr_group)
2771 num_groups++;
2772
2773 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2774 GFP_KERNEL);
2775 if (!uport->tty_groups) {
2776 ret = -ENOMEM;
2777 goto out;
2778 }
2779 uport->tty_groups[0] = &tty_dev_attr_group;
2780 if (uport->attr_group)
2781 uport->tty_groups[1] = uport->attr_group;
2782
2783 /*
2784 * Register the port whether it's detected or not. This allows
2785 * setserial to be used to alter this port's parameters.
2786 */
2787 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2788 uport->line, uport->dev, port, uport->tty_groups);
2789 if (likely(!IS_ERR(tty_dev))) {
2790 device_set_wakeup_capable(tty_dev, 1);
2791 } else {
2792 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2793 uport->line);
2794 }
2795
2796 /*
2797 * Ensure UPF_DEAD is not set.
2798 */
2799 uport->flags &= ~UPF_DEAD;
2800
2801 out:
2802 mutex_unlock(&port->mutex);
2803 mutex_unlock(&port_mutex);
2804
2805 return ret;
2806}
2807
2808/**
2809 * uart_remove_one_port - detach a driver defined port structure
2810 * @drv: pointer to the uart low level driver structure for this port
2811 * @uport: uart port structure for this port
2812 *
2813 * This unhooks (and hangs up) the specified port structure from the
2814 * core driver. No further calls will be made to the low-level code
2815 * for this port.
2816 */
2817int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2818{
2819 struct uart_state *state = drv->state + uport->line;
2820 struct tty_port *port = &state->port;
2821 struct uart_port *uart_port;
2822 struct tty_struct *tty;
2823 int ret = 0;
2824
2825 BUG_ON(in_interrupt());
2826
2827 mutex_lock(&port_mutex);
2828
2829 /*
2830 * Mark the port "dead" - this prevents any opens from
2831 * succeeding while we shut down the port.
2832 */
2833 mutex_lock(&port->mutex);
2834 uart_port = uart_port_check(state);
2835 if (uart_port != uport)
2836 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2837 uart_port, uport);
2838
2839 if (!uart_port) {
2840 mutex_unlock(&port->mutex);
2841 ret = -EINVAL;
2842 goto out;
2843 }
2844 uport->flags |= UPF_DEAD;
2845 mutex_unlock(&port->mutex);
2846
2847 /*
2848 * Remove the devices from the tty layer
2849 */
2850 tty_unregister_device(drv->tty_driver, uport->line);
2851
2852 tty = tty_port_tty_get(port);
2853 if (tty) {
2854 tty_vhangup(port->tty);
2855 tty_kref_put(tty);
2856 }
2857
2858 /*
2859 * If the port is used as a console, unregister it
2860 */
2861 if (uart_console(uport))
2862 unregister_console(uport->cons);
2863
2864 /*
2865 * Free the port IO and memory resources, if any.
2866 */
2867 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
2868 uport->ops->release_port(uport);
2869 kfree(uport->tty_groups);
2870
2871 /*
2872 * Indicate that there isn't a port here anymore.
2873 */
2874 uport->type = PORT_UNKNOWN;
2875
2876 mutex_lock(&port->mutex);
2877 WARN_ON(atomic_dec_return(&state->refcount) < 0);
2878 wait_event(state->remove_wait, !atomic_read(&state->refcount));
2879 state->uart_port = NULL;
2880 mutex_unlock(&port->mutex);
2881out:
2882 mutex_unlock(&port_mutex);
2883
2884 return ret;
2885}
2886
2887/*
2888 * Are the two ports equivalent?
2889 */
2890int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2891{
2892 if (port1->iotype != port2->iotype)
2893 return 0;
2894
2895 switch (port1->iotype) {
2896 case UPIO_PORT:
2897 return (port1->iobase == port2->iobase);
2898 case UPIO_HUB6:
2899 return (port1->iobase == port2->iobase) &&
2900 (port1->hub6 == port2->hub6);
2901 case UPIO_MEM:
2902 case UPIO_MEM16:
2903 case UPIO_MEM32:
2904 case UPIO_MEM32BE:
2905 case UPIO_AU:
2906 case UPIO_TSI:
2907 return (port1->mapbase == port2->mapbase);
2908 }
2909 return 0;
2910}
2911EXPORT_SYMBOL(uart_match_port);
2912
2913/**
2914 * uart_handle_dcd_change - handle a change of carrier detect state
2915 * @uport: uart_port structure for the open port
2916 * @status: new carrier detect status, nonzero if active
2917 *
2918 * Caller must hold uport->lock
2919 */
2920void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2921{
2922 struct tty_port *port = &uport->state->port;
2923 struct tty_struct *tty = port->tty;
2924 struct tty_ldisc *ld;
2925
2926 lockdep_assert_held_once(&uport->lock);
2927
2928 if (tty) {
2929 ld = tty_ldisc_ref(tty);
2930 if (ld) {
2931 if (ld->ops->dcd_change)
2932 ld->ops->dcd_change(tty, status);
2933 tty_ldisc_deref(ld);
2934 }
2935 }
2936
2937 uport->icount.dcd++;
2938
2939 if (uart_dcd_enabled(uport)) {
2940 if (status)
2941 wake_up_interruptible(&port->open_wait);
2942 else if (tty)
2943 tty_hangup(tty);
2944 }
2945}
2946EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2947
2948/**
2949 * uart_handle_cts_change - handle a change of clear-to-send state
2950 * @uport: uart_port structure for the open port
2951 * @status: new clear to send status, nonzero if active
2952 *
2953 * Caller must hold uport->lock
2954 */
2955void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2956{
2957 lockdep_assert_held_once(&uport->lock);
2958
2959 uport->icount.cts++;
2960
2961 if (uart_softcts_mode(uport)) {
2962 if (uport->hw_stopped) {
2963 if (status) {
2964 uport->hw_stopped = 0;
2965 uport->ops->start_tx(uport);
2966 uart_write_wakeup(uport);
2967 }
2968 } else {
2969 if (!status) {
2970 uport->hw_stopped = 1;
2971 uport->ops->stop_tx(uport);
2972 }
2973 }
2974
2975 }
2976}
2977EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2978
2979/**
2980 * uart_insert_char - push a char to the uart layer
2981 *
2982 * User is responsible to call tty_flip_buffer_push when they are done with
2983 * insertion.
2984 *
2985 * @port: corresponding port
2986 * @status: state of the serial port RX buffer (LSR for 8250)
2987 * @overrun: mask of overrun bits in @status
2988 * @ch: character to push
2989 * @flag: flag for the character (see TTY_NORMAL and friends)
2990 */
2991void uart_insert_char(struct uart_port *port, unsigned int status,
2992 unsigned int overrun, unsigned int ch, unsigned int flag)
2993{
2994 struct tty_port *tport = &port->state->port;
2995
2996 if ((status & port->ignore_status_mask & ~overrun) == 0)
2997 if (tty_insert_flip_char(tport, ch, flag) == 0)
2998 ++port->icount.buf_overrun;
2999
3000 /*
3001 * Overrun is special. Since it's reported immediately,
3002 * it doesn't affect the current character.
3003 */
3004 if (status & ~port->ignore_status_mask & overrun)
3005 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
3006 ++port->icount.buf_overrun;
3007}
3008EXPORT_SYMBOL_GPL(uart_insert_char);
3009
3010EXPORT_SYMBOL(uart_write_wakeup);
3011EXPORT_SYMBOL(uart_register_driver);
3012EXPORT_SYMBOL(uart_unregister_driver);
3013EXPORT_SYMBOL(uart_suspend_port);
3014EXPORT_SYMBOL(uart_resume_port);
3015EXPORT_SYMBOL(uart_add_one_port);
3016EXPORT_SYMBOL(uart_remove_one_port);
3017
3018MODULE_DESCRIPTION("Serial driver core");
3019MODULE_LICENSE("GPL");