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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/proc_fs.h>
30#include <linux/seq_file.h>
31#include <linux/device.h>
32#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
33#include <linux/serial_core.h>
34#include <linux/delay.h>
35#include <linux/mutex.h>
36
37#include <asm/irq.h>
38#include <asm/uaccess.h>
39
40/*
41 * This is used to lock changes in serial line configuration.
42 */
43static DEFINE_MUTEX(port_mutex);
44
45/*
46 * lockdep: port->lock is initialized in two places, but we
47 * want only one lock-class:
48 */
49static struct lock_class_key port_lock_key;
50
51#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
52
53static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
54 struct ktermios *old_termios);
55static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
56static void uart_change_pm(struct uart_state *state,
57 enum uart_pm_state pm_state);
58
59static void uart_port_shutdown(struct tty_port *port);
60
61/*
62 * This routine is used by the interrupt handler to schedule processing in
63 * the software interrupt portion of the driver.
64 */
65void uart_write_wakeup(struct uart_port *port)
66{
67 struct uart_state *state = port->state;
68 /*
69 * This means you called this function _after_ the port was
70 * closed. No cookie for you.
71 */
72 BUG_ON(!state);
73 tty_wakeup(state->port.tty);
74}
75
76static void uart_stop(struct tty_struct *tty)
77{
78 struct uart_state *state = tty->driver_data;
79 struct uart_port *port = state->uart_port;
80 unsigned long flags;
81
82 spin_lock_irqsave(&port->lock, flags);
83 port->ops->stop_tx(port);
84 spin_unlock_irqrestore(&port->lock, flags);
85}
86
87static void __uart_start(struct tty_struct *tty)
88{
89 struct uart_state *state = tty->driver_data;
90 struct uart_port *port = state->uart_port;
91
92 if (!tty->stopped && !tty->hw_stopped)
93 port->ops->start_tx(port);
94}
95
96static void uart_start(struct tty_struct *tty)
97{
98 struct uart_state *state = tty->driver_data;
99 struct uart_port *port = state->uart_port;
100 unsigned long flags;
101
102 spin_lock_irqsave(&port->lock, flags);
103 __uart_start(tty);
104 spin_unlock_irqrestore(&port->lock, flags);
105}
106
107static inline void
108uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
109{
110 unsigned long flags;
111 unsigned int old;
112
113 spin_lock_irqsave(&port->lock, flags);
114 old = port->mctrl;
115 port->mctrl = (old & ~clear) | set;
116 if (old != port->mctrl)
117 port->ops->set_mctrl(port, port->mctrl);
118 spin_unlock_irqrestore(&port->lock, flags);
119}
120
121#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
122#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
123
124/*
125 * Startup the port. This will be called once per open. All calls
126 * will be serialised by the per-port mutex.
127 */
128static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
129 int init_hw)
130{
131 struct uart_port *uport = state->uart_port;
132 struct tty_port *port = &state->port;
133 unsigned long page;
134 int retval = 0;
135
136 if (uport->type == PORT_UNKNOWN)
137 return 1;
138
139 /*
140 * Make sure the device is in D0 state.
141 */
142 uart_change_pm(state, UART_PM_STATE_ON);
143
144 /*
145 * Initialise and allocate the transmit and temporary
146 * buffer.
147 */
148 if (!state->xmit.buf) {
149 /* This is protected by the per port mutex */
150 page = get_zeroed_page(GFP_KERNEL);
151 if (!page)
152 return -ENOMEM;
153
154 state->xmit.buf = (unsigned char *) page;
155 uart_circ_clear(&state->xmit);
156 }
157
158 retval = uport->ops->startup(uport);
159 if (retval == 0) {
160 if (uart_console(uport) && uport->cons->cflag) {
161 tty->termios.c_cflag = uport->cons->cflag;
162 uport->cons->cflag = 0;
163 }
164 /*
165 * Initialise the hardware port settings.
166 */
167 uart_change_speed(tty, state, NULL);
168
169 if (init_hw) {
170 /*
171 * Setup the RTS and DTR signals once the
172 * port is open and ready to respond.
173 */
174 if (tty->termios.c_cflag & CBAUD)
175 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
176 }
177
178 if (tty_port_cts_enabled(port)) {
179 spin_lock_irq(&uport->lock);
180 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
181 tty->hw_stopped = 1;
182 spin_unlock_irq(&uport->lock);
183 }
184 }
185
186 /*
187 * This is to allow setserial on this port. People may want to set
188 * port/irq/type and then reconfigure the port properly if it failed
189 * now.
190 */
191 if (retval && capable(CAP_SYS_ADMIN))
192 return 1;
193
194 return retval;
195}
196
197static int uart_startup(struct tty_struct *tty, struct uart_state *state,
198 int init_hw)
199{
200 struct tty_port *port = &state->port;
201 int retval;
202
203 if (port->flags & ASYNC_INITIALIZED)
204 return 0;
205
206 /*
207 * Set the TTY IO error marker - we will only clear this
208 * once we have successfully opened the port.
209 */
210 set_bit(TTY_IO_ERROR, &tty->flags);
211
212 retval = uart_port_startup(tty, state, init_hw);
213 if (!retval) {
214 set_bit(ASYNCB_INITIALIZED, &port->flags);
215 clear_bit(TTY_IO_ERROR, &tty->flags);
216 } else if (retval > 0)
217 retval = 0;
218
219 return retval;
220}
221
222/*
223 * This routine will shutdown a serial port; interrupts are disabled, and
224 * DTR is dropped if the hangup on close termio flag is on. Calls to
225 * uart_shutdown are serialised by the per-port semaphore.
226 */
227static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
228{
229 struct uart_port *uport = state->uart_port;
230 struct tty_port *port = &state->port;
231
232 /*
233 * Set the TTY IO error marker
234 */
235 if (tty)
236 set_bit(TTY_IO_ERROR, &tty->flags);
237
238 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
239 /*
240 * Turn off DTR and RTS early.
241 */
242 if (!tty || (tty->termios.c_cflag & HUPCL))
243 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
244
245 uart_port_shutdown(port);
246 }
247
248 /*
249 * It's possible for shutdown to be called after suspend if we get
250 * a DCD drop (hangup) at just the right time. Clear suspended bit so
251 * we don't try to resume a port that has been shutdown.
252 */
253 clear_bit(ASYNCB_SUSPENDED, &port->flags);
254
255 /*
256 * Free the transmit buffer page.
257 */
258 if (state->xmit.buf) {
259 free_page((unsigned long)state->xmit.buf);
260 state->xmit.buf = NULL;
261 }
262}
263
264/**
265 * uart_update_timeout - update per-port FIFO timeout.
266 * @port: uart_port structure describing the port
267 * @cflag: termios cflag value
268 * @baud: speed of the port
269 *
270 * Set the port FIFO timeout value. The @cflag value should
271 * reflect the actual hardware settings.
272 */
273void
274uart_update_timeout(struct uart_port *port, unsigned int cflag,
275 unsigned int baud)
276{
277 unsigned int bits;
278
279 /* byte size and parity */
280 switch (cflag & CSIZE) {
281 case CS5:
282 bits = 7;
283 break;
284 case CS6:
285 bits = 8;
286 break;
287 case CS7:
288 bits = 9;
289 break;
290 default:
291 bits = 10;
292 break; /* CS8 */
293 }
294
295 if (cflag & CSTOPB)
296 bits++;
297 if (cflag & PARENB)
298 bits++;
299
300 /*
301 * The total number of bits to be transmitted in the fifo.
302 */
303 bits = bits * port->fifosize;
304
305 /*
306 * Figure the timeout to send the above number of bits.
307 * Add .02 seconds of slop
308 */
309 port->timeout = (HZ * bits) / baud + HZ/50;
310}
311
312EXPORT_SYMBOL(uart_update_timeout);
313
314/**
315 * uart_get_baud_rate - return baud rate for a particular port
316 * @port: uart_port structure describing the port in question.
317 * @termios: desired termios settings.
318 * @old: old termios (or NULL)
319 * @min: minimum acceptable baud rate
320 * @max: maximum acceptable baud rate
321 *
322 * Decode the termios structure into a numeric baud rate,
323 * taking account of the magic 38400 baud rate (with spd_*
324 * flags), and mapping the %B0 rate to 9600 baud.
325 *
326 * If the new baud rate is invalid, try the old termios setting.
327 * If it's still invalid, we try 9600 baud.
328 *
329 * Update the @termios structure to reflect the baud rate
330 * we're actually going to be using. Don't do this for the case
331 * where B0 is requested ("hang up").
332 */
333unsigned int
334uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
335 struct ktermios *old, unsigned int min, unsigned int max)
336{
337 unsigned int try, baud, altbaud = 38400;
338 int hung_up = 0;
339 upf_t flags = port->flags & UPF_SPD_MASK;
340
341 if (flags == UPF_SPD_HI)
342 altbaud = 57600;
343 else if (flags == UPF_SPD_VHI)
344 altbaud = 115200;
345 else if (flags == UPF_SPD_SHI)
346 altbaud = 230400;
347 else if (flags == UPF_SPD_WARP)
348 altbaud = 460800;
349
350 for (try = 0; try < 2; try++) {
351 baud = tty_termios_baud_rate(termios);
352
353 /*
354 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
355 * Die! Die! Die!
356 */
357 if (baud == 38400)
358 baud = altbaud;
359
360 /*
361 * Special case: B0 rate.
362 */
363 if (baud == 0) {
364 hung_up = 1;
365 baud = 9600;
366 }
367
368 if (baud >= min && baud <= max)
369 return baud;
370
371 /*
372 * Oops, the quotient was zero. Try again with
373 * the old baud rate if possible.
374 */
375 termios->c_cflag &= ~CBAUD;
376 if (old) {
377 baud = tty_termios_baud_rate(old);
378 if (!hung_up)
379 tty_termios_encode_baud_rate(termios,
380 baud, baud);
381 old = NULL;
382 continue;
383 }
384
385 /*
386 * As a last resort, if the range cannot be met then clip to
387 * the nearest chip supported rate.
388 */
389 if (!hung_up) {
390 if (baud <= min)
391 tty_termios_encode_baud_rate(termios,
392 min + 1, min + 1);
393 else
394 tty_termios_encode_baud_rate(termios,
395 max - 1, max - 1);
396 }
397 }
398 /* Should never happen */
399 WARN_ON(1);
400 return 0;
401}
402
403EXPORT_SYMBOL(uart_get_baud_rate);
404
405/**
406 * uart_get_divisor - return uart clock divisor
407 * @port: uart_port structure describing the port.
408 * @baud: desired baud rate
409 *
410 * Calculate the uart clock divisor for the port.
411 */
412unsigned int
413uart_get_divisor(struct uart_port *port, unsigned int baud)
414{
415 unsigned int quot;
416
417 /*
418 * Old custom speed handling.
419 */
420 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
421 quot = port->custom_divisor;
422 else
423 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
424
425 return quot;
426}
427
428EXPORT_SYMBOL(uart_get_divisor);
429
430/* FIXME: Consistent locking policy */
431static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
432 struct ktermios *old_termios)
433{
434 struct tty_port *port = &state->port;
435 struct uart_port *uport = state->uart_port;
436 struct ktermios *termios;
437
438 /*
439 * If we have no tty, termios, or the port does not exist,
440 * then we can't set the parameters for this port.
441 */
442 if (!tty || uport->type == PORT_UNKNOWN)
443 return;
444
445 termios = &tty->termios;
446
447 /*
448 * Set flags based on termios cflag
449 */
450 if (termios->c_cflag & CRTSCTS)
451 set_bit(ASYNCB_CTS_FLOW, &port->flags);
452 else
453 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
454
455 if (termios->c_cflag & CLOCAL)
456 clear_bit(ASYNCB_CHECK_CD, &port->flags);
457 else
458 set_bit(ASYNCB_CHECK_CD, &port->flags);
459
460 uport->ops->set_termios(uport, termios, old_termios);
461}
462
463static inline int __uart_put_char(struct uart_port *port,
464 struct circ_buf *circ, unsigned char c)
465{
466 unsigned long flags;
467 int ret = 0;
468
469 if (!circ->buf)
470 return 0;
471
472 spin_lock_irqsave(&port->lock, flags);
473 if (uart_circ_chars_free(circ) != 0) {
474 circ->buf[circ->head] = c;
475 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
476 ret = 1;
477 }
478 spin_unlock_irqrestore(&port->lock, flags);
479 return ret;
480}
481
482static int uart_put_char(struct tty_struct *tty, unsigned char ch)
483{
484 struct uart_state *state = tty->driver_data;
485
486 return __uart_put_char(state->uart_port, &state->xmit, ch);
487}
488
489static void uart_flush_chars(struct tty_struct *tty)
490{
491 uart_start(tty);
492}
493
494static int uart_write(struct tty_struct *tty,
495 const unsigned char *buf, int count)
496{
497 struct uart_state *state = tty->driver_data;
498 struct uart_port *port;
499 struct circ_buf *circ;
500 unsigned long flags;
501 int c, ret = 0;
502
503 /*
504 * This means you called this function _after_ the port was
505 * closed. No cookie for you.
506 */
507 if (!state) {
508 WARN_ON(1);
509 return -EL3HLT;
510 }
511
512 port = state->uart_port;
513 circ = &state->xmit;
514
515 if (!circ->buf)
516 return 0;
517
518 spin_lock_irqsave(&port->lock, flags);
519 while (1) {
520 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
521 if (count < c)
522 c = count;
523 if (c <= 0)
524 break;
525 memcpy(circ->buf + circ->head, buf, c);
526 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
527 buf += c;
528 count -= c;
529 ret += c;
530 }
531 spin_unlock_irqrestore(&port->lock, flags);
532
533 uart_start(tty);
534 return ret;
535}
536
537static int uart_write_room(struct tty_struct *tty)
538{
539 struct uart_state *state = tty->driver_data;
540 unsigned long flags;
541 int ret;
542
543 spin_lock_irqsave(&state->uart_port->lock, flags);
544 ret = uart_circ_chars_free(&state->xmit);
545 spin_unlock_irqrestore(&state->uart_port->lock, flags);
546 return ret;
547}
548
549static int uart_chars_in_buffer(struct tty_struct *tty)
550{
551 struct uart_state *state = tty->driver_data;
552 unsigned long flags;
553 int ret;
554
555 spin_lock_irqsave(&state->uart_port->lock, flags);
556 ret = uart_circ_chars_pending(&state->xmit);
557 spin_unlock_irqrestore(&state->uart_port->lock, flags);
558 return ret;
559}
560
561static void uart_flush_buffer(struct tty_struct *tty)
562{
563 struct uart_state *state = tty->driver_data;
564 struct uart_port *port;
565 unsigned long flags;
566
567 /*
568 * This means you called this function _after_ the port was
569 * closed. No cookie for you.
570 */
571 if (!state) {
572 WARN_ON(1);
573 return;
574 }
575
576 port = state->uart_port;
577 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
578
579 spin_lock_irqsave(&port->lock, flags);
580 uart_circ_clear(&state->xmit);
581 if (port->ops->flush_buffer)
582 port->ops->flush_buffer(port);
583 spin_unlock_irqrestore(&port->lock, flags);
584 tty_wakeup(tty);
585}
586
587/*
588 * This function is used to send a high-priority XON/XOFF character to
589 * the device
590 */
591static void uart_send_xchar(struct tty_struct *tty, char ch)
592{
593 struct uart_state *state = tty->driver_data;
594 struct uart_port *port = state->uart_port;
595 unsigned long flags;
596
597 if (port->ops->send_xchar)
598 port->ops->send_xchar(port, ch);
599 else {
600 port->x_char = ch;
601 if (ch) {
602 spin_lock_irqsave(&port->lock, flags);
603 port->ops->start_tx(port);
604 spin_unlock_irqrestore(&port->lock, flags);
605 }
606 }
607}
608
609static void uart_throttle(struct tty_struct *tty)
610{
611 struct uart_state *state = tty->driver_data;
612 struct uart_port *port = state->uart_port;
613 uint32_t mask = 0;
614
615 if (I_IXOFF(tty))
616 mask |= UPF_SOFT_FLOW;
617 if (tty->termios.c_cflag & CRTSCTS)
618 mask |= UPF_HARD_FLOW;
619
620 if (port->flags & mask) {
621 port->ops->throttle(port);
622 mask &= ~port->flags;
623 }
624
625 if (mask & UPF_SOFT_FLOW)
626 uart_send_xchar(tty, STOP_CHAR(tty));
627
628 if (mask & UPF_HARD_FLOW)
629 uart_clear_mctrl(port, TIOCM_RTS);
630}
631
632static void uart_unthrottle(struct tty_struct *tty)
633{
634 struct uart_state *state = tty->driver_data;
635 struct uart_port *port = state->uart_port;
636 uint32_t mask = 0;
637
638 if (I_IXOFF(tty))
639 mask |= UPF_SOFT_FLOW;
640 if (tty->termios.c_cflag & CRTSCTS)
641 mask |= UPF_HARD_FLOW;
642
643 if (port->flags & mask) {
644 port->ops->unthrottle(port);
645 mask &= ~port->flags;
646 }
647
648 if (mask & UPF_SOFT_FLOW) {
649 if (port->x_char)
650 port->x_char = 0;
651 else
652 uart_send_xchar(tty, START_CHAR(tty));
653 }
654
655 if (mask & UPF_HARD_FLOW)
656 uart_set_mctrl(port, TIOCM_RTS);
657}
658
659static void do_uart_get_info(struct tty_port *port,
660 struct serial_struct *retinfo)
661{
662 struct uart_state *state = container_of(port, struct uart_state, port);
663 struct uart_port *uport = state->uart_port;
664
665 memset(retinfo, 0, sizeof(*retinfo));
666
667 retinfo->type = uport->type;
668 retinfo->line = uport->line;
669 retinfo->port = uport->iobase;
670 if (HIGH_BITS_OFFSET)
671 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
672 retinfo->irq = uport->irq;
673 retinfo->flags = uport->flags;
674 retinfo->xmit_fifo_size = uport->fifosize;
675 retinfo->baud_base = uport->uartclk / 16;
676 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
677 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
678 ASYNC_CLOSING_WAIT_NONE :
679 jiffies_to_msecs(port->closing_wait) / 10;
680 retinfo->custom_divisor = uport->custom_divisor;
681 retinfo->hub6 = uport->hub6;
682 retinfo->io_type = uport->iotype;
683 retinfo->iomem_reg_shift = uport->regshift;
684 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
685}
686
687static void uart_get_info(struct tty_port *port,
688 struct serial_struct *retinfo)
689{
690 /* Ensure the state we copy is consistent and no hardware changes
691 occur as we go */
692 mutex_lock(&port->mutex);
693 do_uart_get_info(port, retinfo);
694 mutex_unlock(&port->mutex);
695}
696
697static int uart_get_info_user(struct tty_port *port,
698 struct serial_struct __user *retinfo)
699{
700 struct serial_struct tmp;
701 uart_get_info(port, &tmp);
702
703 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
704 return -EFAULT;
705 return 0;
706}
707
708static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
709 struct uart_state *state,
710 struct serial_struct *new_info)
711{
712 struct uart_port *uport = state->uart_port;
713 unsigned long new_port;
714 unsigned int change_irq, change_port, closing_wait;
715 unsigned int old_custom_divisor, close_delay;
716 upf_t old_flags, new_flags;
717 int retval = 0;
718
719 new_port = new_info->port;
720 if (HIGH_BITS_OFFSET)
721 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
722
723 new_info->irq = irq_canonicalize(new_info->irq);
724 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
725 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
726 ASYNC_CLOSING_WAIT_NONE :
727 msecs_to_jiffies(new_info->closing_wait * 10);
728
729
730 change_irq = !(uport->flags & UPF_FIXED_PORT)
731 && new_info->irq != uport->irq;
732
733 /*
734 * Since changing the 'type' of the port changes its resource
735 * allocations, we should treat type changes the same as
736 * IO port changes.
737 */
738 change_port = !(uport->flags & UPF_FIXED_PORT)
739 && (new_port != uport->iobase ||
740 (unsigned long)new_info->iomem_base != uport->mapbase ||
741 new_info->hub6 != uport->hub6 ||
742 new_info->io_type != uport->iotype ||
743 new_info->iomem_reg_shift != uport->regshift ||
744 new_info->type != uport->type);
745
746 old_flags = uport->flags;
747 new_flags = new_info->flags;
748 old_custom_divisor = uport->custom_divisor;
749
750 if (!capable(CAP_SYS_ADMIN)) {
751 retval = -EPERM;
752 if (change_irq || change_port ||
753 (new_info->baud_base != uport->uartclk / 16) ||
754 (close_delay != port->close_delay) ||
755 (closing_wait != port->closing_wait) ||
756 (new_info->xmit_fifo_size &&
757 new_info->xmit_fifo_size != uport->fifosize) ||
758 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
759 goto exit;
760 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
761 (new_flags & UPF_USR_MASK));
762 uport->custom_divisor = new_info->custom_divisor;
763 goto check_and_exit;
764 }
765
766 /*
767 * Ask the low level driver to verify the settings.
768 */
769 if (uport->ops->verify_port)
770 retval = uport->ops->verify_port(uport, new_info);
771
772 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
773 (new_info->baud_base < 9600))
774 retval = -EINVAL;
775
776 if (retval)
777 goto exit;
778
779 if (change_port || change_irq) {
780 retval = -EBUSY;
781
782 /*
783 * Make sure that we are the sole user of this port.
784 */
785 if (tty_port_users(port) > 1)
786 goto exit;
787
788 /*
789 * We need to shutdown the serial port at the old
790 * port/type/irq combination.
791 */
792 uart_shutdown(tty, state);
793 }
794
795 if (change_port) {
796 unsigned long old_iobase, old_mapbase;
797 unsigned int old_type, old_iotype, old_hub6, old_shift;
798
799 old_iobase = uport->iobase;
800 old_mapbase = uport->mapbase;
801 old_type = uport->type;
802 old_hub6 = uport->hub6;
803 old_iotype = uport->iotype;
804 old_shift = uport->regshift;
805
806 /*
807 * Free and release old regions
808 */
809 if (old_type != PORT_UNKNOWN)
810 uport->ops->release_port(uport);
811
812 uport->iobase = new_port;
813 uport->type = new_info->type;
814 uport->hub6 = new_info->hub6;
815 uport->iotype = new_info->io_type;
816 uport->regshift = new_info->iomem_reg_shift;
817 uport->mapbase = (unsigned long)new_info->iomem_base;
818
819 /*
820 * Claim and map the new regions
821 */
822 if (uport->type != PORT_UNKNOWN) {
823 retval = uport->ops->request_port(uport);
824 } else {
825 /* Always success - Jean II */
826 retval = 0;
827 }
828
829 /*
830 * If we fail to request resources for the
831 * new port, try to restore the old settings.
832 */
833 if (retval) {
834 uport->iobase = old_iobase;
835 uport->type = old_type;
836 uport->hub6 = old_hub6;
837 uport->iotype = old_iotype;
838 uport->regshift = old_shift;
839 uport->mapbase = old_mapbase;
840
841 if (old_type != PORT_UNKNOWN) {
842 retval = uport->ops->request_port(uport);
843 /*
844 * If we failed to restore the old settings,
845 * we fail like this.
846 */
847 if (retval)
848 uport->type = PORT_UNKNOWN;
849
850 /*
851 * We failed anyway.
852 */
853 retval = -EBUSY;
854 }
855
856 /* Added to return the correct error -Ram Gupta */
857 goto exit;
858 }
859 }
860
861 if (change_irq)
862 uport->irq = new_info->irq;
863 if (!(uport->flags & UPF_FIXED_PORT))
864 uport->uartclk = new_info->baud_base * 16;
865 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
866 (new_flags & UPF_CHANGE_MASK);
867 uport->custom_divisor = new_info->custom_divisor;
868 port->close_delay = close_delay;
869 port->closing_wait = closing_wait;
870 if (new_info->xmit_fifo_size)
871 uport->fifosize = new_info->xmit_fifo_size;
872 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
873
874 check_and_exit:
875 retval = 0;
876 if (uport->type == PORT_UNKNOWN)
877 goto exit;
878 if (port->flags & ASYNC_INITIALIZED) {
879 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
880 old_custom_divisor != uport->custom_divisor) {
881 /*
882 * If they're setting up a custom divisor or speed,
883 * instead of clearing it, then bitch about it. No
884 * need to rate-limit; it's CAP_SYS_ADMIN only.
885 */
886 if (uport->flags & UPF_SPD_MASK) {
887 char buf[64];
888 printk(KERN_NOTICE
889 "%s sets custom speed on %s. This "
890 "is deprecated.\n", current->comm,
891 tty_name(port->tty, buf));
892 }
893 uart_change_speed(tty, state, NULL);
894 }
895 } else
896 retval = uart_startup(tty, state, 1);
897 exit:
898 return retval;
899}
900
901static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
902 struct serial_struct __user *newinfo)
903{
904 struct serial_struct new_serial;
905 struct tty_port *port = &state->port;
906 int retval;
907
908 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
909 return -EFAULT;
910
911 /*
912 * This semaphore protects port->count. It is also
913 * very useful to prevent opens. Also, take the
914 * port configuration semaphore to make sure that a
915 * module insertion/removal doesn't change anything
916 * under us.
917 */
918 mutex_lock(&port->mutex);
919 retval = uart_set_info(tty, port, state, &new_serial);
920 mutex_unlock(&port->mutex);
921 return retval;
922}
923
924/**
925 * uart_get_lsr_info - get line status register info
926 * @tty: tty associated with the UART
927 * @state: UART being queried
928 * @value: returned modem value
929 *
930 * Note: uart_ioctl protects us against hangups.
931 */
932static int uart_get_lsr_info(struct tty_struct *tty,
933 struct uart_state *state, unsigned int __user *value)
934{
935 struct uart_port *uport = state->uart_port;
936 unsigned int result;
937
938 result = uport->ops->tx_empty(uport);
939
940 /*
941 * If we're about to load something into the transmit
942 * register, we'll pretend the transmitter isn't empty to
943 * avoid a race condition (depending on when the transmit
944 * interrupt happens).
945 */
946 if (uport->x_char ||
947 ((uart_circ_chars_pending(&state->xmit) > 0) &&
948 !tty->stopped && !tty->hw_stopped))
949 result &= ~TIOCSER_TEMT;
950
951 return put_user(result, value);
952}
953
954static int uart_tiocmget(struct tty_struct *tty)
955{
956 struct uart_state *state = tty->driver_data;
957 struct tty_port *port = &state->port;
958 struct uart_port *uport = state->uart_port;
959 int result = -EIO;
960
961 mutex_lock(&port->mutex);
962 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
963 result = uport->mctrl;
964 spin_lock_irq(&uport->lock);
965 result |= uport->ops->get_mctrl(uport);
966 spin_unlock_irq(&uport->lock);
967 }
968 mutex_unlock(&port->mutex);
969
970 return result;
971}
972
973static int
974uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
975{
976 struct uart_state *state = tty->driver_data;
977 struct uart_port *uport = state->uart_port;
978 struct tty_port *port = &state->port;
979 int ret = -EIO;
980
981 mutex_lock(&port->mutex);
982 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
983 uart_update_mctrl(uport, set, clear);
984 ret = 0;
985 }
986 mutex_unlock(&port->mutex);
987 return ret;
988}
989
990static int uart_break_ctl(struct tty_struct *tty, int break_state)
991{
992 struct uart_state *state = tty->driver_data;
993 struct tty_port *port = &state->port;
994 struct uart_port *uport = state->uart_port;
995
996 mutex_lock(&port->mutex);
997
998 if (uport->type != PORT_UNKNOWN)
999 uport->ops->break_ctl(uport, break_state);
1000
1001 mutex_unlock(&port->mutex);
1002 return 0;
1003}
1004
1005static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1006{
1007 struct uart_port *uport = state->uart_port;
1008 struct tty_port *port = &state->port;
1009 int flags, ret;
1010
1011 if (!capable(CAP_SYS_ADMIN))
1012 return -EPERM;
1013
1014 /*
1015 * Take the per-port semaphore. This prevents count from
1016 * changing, and hence any extra opens of the port while
1017 * we're auto-configuring.
1018 */
1019 if (mutex_lock_interruptible(&port->mutex))
1020 return -ERESTARTSYS;
1021
1022 ret = -EBUSY;
1023 if (tty_port_users(port) == 1) {
1024 uart_shutdown(tty, state);
1025
1026 /*
1027 * If we already have a port type configured,
1028 * we must release its resources.
1029 */
1030 if (uport->type != PORT_UNKNOWN)
1031 uport->ops->release_port(uport);
1032
1033 flags = UART_CONFIG_TYPE;
1034 if (uport->flags & UPF_AUTO_IRQ)
1035 flags |= UART_CONFIG_IRQ;
1036
1037 /*
1038 * This will claim the ports resources if
1039 * a port is found.
1040 */
1041 uport->ops->config_port(uport, flags);
1042
1043 ret = uart_startup(tty, state, 1);
1044 }
1045 mutex_unlock(&port->mutex);
1046 return ret;
1047}
1048
1049/*
1050 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1051 * - mask passed in arg for lines of interest
1052 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1053 * Caller should use TIOCGICOUNT to see which one it was
1054 *
1055 * FIXME: This wants extracting into a common all driver implementation
1056 * of TIOCMWAIT using tty_port.
1057 */
1058static int
1059uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1060{
1061 struct uart_port *uport = state->uart_port;
1062 struct tty_port *port = &state->port;
1063 DECLARE_WAITQUEUE(wait, current);
1064 struct uart_icount cprev, cnow;
1065 int ret;
1066
1067 /*
1068 * note the counters on entry
1069 */
1070 spin_lock_irq(&uport->lock);
1071 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1072
1073 /*
1074 * Force modem status interrupts on
1075 */
1076 uport->ops->enable_ms(uport);
1077 spin_unlock_irq(&uport->lock);
1078
1079 add_wait_queue(&port->delta_msr_wait, &wait);
1080 for (;;) {
1081 spin_lock_irq(&uport->lock);
1082 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1083 spin_unlock_irq(&uport->lock);
1084
1085 set_current_state(TASK_INTERRUPTIBLE);
1086
1087 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1088 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1089 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1090 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1091 ret = 0;
1092 break;
1093 }
1094
1095 schedule();
1096
1097 /* see if a signal did it */
1098 if (signal_pending(current)) {
1099 ret = -ERESTARTSYS;
1100 break;
1101 }
1102
1103 cprev = cnow;
1104 }
1105
1106 current->state = TASK_RUNNING;
1107 remove_wait_queue(&port->delta_msr_wait, &wait);
1108
1109 return ret;
1110}
1111
1112/*
1113 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1114 * Return: write counters to the user passed counter struct
1115 * NB: both 1->0 and 0->1 transitions are counted except for
1116 * RI where only 0->1 is counted.
1117 */
1118static int uart_get_icount(struct tty_struct *tty,
1119 struct serial_icounter_struct *icount)
1120{
1121 struct uart_state *state = tty->driver_data;
1122 struct uart_icount cnow;
1123 struct uart_port *uport = state->uart_port;
1124
1125 spin_lock_irq(&uport->lock);
1126 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1127 spin_unlock_irq(&uport->lock);
1128
1129 icount->cts = cnow.cts;
1130 icount->dsr = cnow.dsr;
1131 icount->rng = cnow.rng;
1132 icount->dcd = cnow.dcd;
1133 icount->rx = cnow.rx;
1134 icount->tx = cnow.tx;
1135 icount->frame = cnow.frame;
1136 icount->overrun = cnow.overrun;
1137 icount->parity = cnow.parity;
1138 icount->brk = cnow.brk;
1139 icount->buf_overrun = cnow.buf_overrun;
1140
1141 return 0;
1142}
1143
1144/*
1145 * Called via sys_ioctl. We can use spin_lock_irq() here.
1146 */
1147static int
1148uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1149 unsigned long arg)
1150{
1151 struct uart_state *state = tty->driver_data;
1152 struct tty_port *port = &state->port;
1153 void __user *uarg = (void __user *)arg;
1154 int ret = -ENOIOCTLCMD;
1155
1156
1157 /*
1158 * These ioctls don't rely on the hardware to be present.
1159 */
1160 switch (cmd) {
1161 case TIOCGSERIAL:
1162 ret = uart_get_info_user(port, uarg);
1163 break;
1164
1165 case TIOCSSERIAL:
1166 ret = uart_set_info_user(tty, state, uarg);
1167 break;
1168
1169 case TIOCSERCONFIG:
1170 ret = uart_do_autoconfig(tty, state);
1171 break;
1172
1173 case TIOCSERGWILD: /* obsolete */
1174 case TIOCSERSWILD: /* obsolete */
1175 ret = 0;
1176 break;
1177 }
1178
1179 if (ret != -ENOIOCTLCMD)
1180 goto out;
1181
1182 if (tty->flags & (1 << TTY_IO_ERROR)) {
1183 ret = -EIO;
1184 goto out;
1185 }
1186
1187 /*
1188 * The following should only be used when hardware is present.
1189 */
1190 switch (cmd) {
1191 case TIOCMIWAIT:
1192 ret = uart_wait_modem_status(state, arg);
1193 break;
1194 }
1195
1196 if (ret != -ENOIOCTLCMD)
1197 goto out;
1198
1199 mutex_lock(&port->mutex);
1200
1201 if (tty->flags & (1 << TTY_IO_ERROR)) {
1202 ret = -EIO;
1203 goto out_up;
1204 }
1205
1206 /*
1207 * All these rely on hardware being present and need to be
1208 * protected against the tty being hung up.
1209 */
1210 switch (cmd) {
1211 case TIOCSERGETLSR: /* Get line status register */
1212 ret = uart_get_lsr_info(tty, state, uarg);
1213 break;
1214
1215 default: {
1216 struct uart_port *uport = state->uart_port;
1217 if (uport->ops->ioctl)
1218 ret = uport->ops->ioctl(uport, cmd, arg);
1219 break;
1220 }
1221 }
1222out_up:
1223 mutex_unlock(&port->mutex);
1224out:
1225 return ret;
1226}
1227
1228static void uart_set_ldisc(struct tty_struct *tty)
1229{
1230 struct uart_state *state = tty->driver_data;
1231 struct uart_port *uport = state->uart_port;
1232
1233 if (uport->ops->set_ldisc)
1234 uport->ops->set_ldisc(uport, tty->termios.c_line);
1235}
1236
1237static void uart_set_termios(struct tty_struct *tty,
1238 struct ktermios *old_termios)
1239{
1240 struct uart_state *state = tty->driver_data;
1241 struct uart_port *uport = state->uart_port;
1242 unsigned long flags;
1243 unsigned int cflag = tty->termios.c_cflag;
1244 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1245 bool sw_changed = false;
1246
1247 /*
1248 * Drivers doing software flow control also need to know
1249 * about changes to these input settings.
1250 */
1251 if (uport->flags & UPF_SOFT_FLOW) {
1252 iflag_mask |= IXANY|IXON|IXOFF;
1253 sw_changed =
1254 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1255 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1256 }
1257
1258 /*
1259 * These are the bits that are used to setup various
1260 * flags in the low level driver. We can ignore the Bfoo
1261 * bits in c_cflag; c_[io]speed will always be set
1262 * appropriately by set_termios() in tty_ioctl.c
1263 */
1264 if ((cflag ^ old_termios->c_cflag) == 0 &&
1265 tty->termios.c_ospeed == old_termios->c_ospeed &&
1266 tty->termios.c_ispeed == old_termios->c_ispeed &&
1267 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1268 !sw_changed) {
1269 return;
1270 }
1271
1272 uart_change_speed(tty, state, old_termios);
1273
1274 /* Handle transition to B0 status */
1275 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1276 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1277 /* Handle transition away from B0 status */
1278 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1279 unsigned int mask = TIOCM_DTR;
1280 if (!(cflag & CRTSCTS) ||
1281 !test_bit(TTY_THROTTLED, &tty->flags))
1282 mask |= TIOCM_RTS;
1283 uart_set_mctrl(uport, mask);
1284 }
1285
1286 /*
1287 * If the port is doing h/w assisted flow control, do nothing.
1288 * We assume that tty->hw_stopped has never been set.
1289 */
1290 if (uport->flags & UPF_HARD_FLOW)
1291 return;
1292
1293 /* Handle turning off CRTSCTS */
1294 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1295 spin_lock_irqsave(&uport->lock, flags);
1296 tty->hw_stopped = 0;
1297 __uart_start(tty);
1298 spin_unlock_irqrestore(&uport->lock, flags);
1299 }
1300 /* Handle turning on CRTSCTS */
1301 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1302 spin_lock_irqsave(&uport->lock, flags);
1303 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
1304 tty->hw_stopped = 1;
1305 uport->ops->stop_tx(uport);
1306 }
1307 spin_unlock_irqrestore(&uport->lock, flags);
1308 }
1309}
1310
1311/*
1312 * Calls to uart_close() are serialised via the tty_lock in
1313 * drivers/tty/tty_io.c:tty_release()
1314 * drivers/tty/tty_io.c:do_tty_hangup()
1315 * This runs from a workqueue and can sleep for a _short_ time only.
1316 */
1317static void uart_close(struct tty_struct *tty, struct file *filp)
1318{
1319 struct uart_state *state = tty->driver_data;
1320 struct tty_port *port;
1321 struct uart_port *uport;
1322 unsigned long flags;
1323
1324 if (!state)
1325 return;
1326
1327 uport = state->uart_port;
1328 port = &state->port;
1329
1330 pr_debug("uart_close(%d) called\n", uport ? uport->line : -1);
1331
1332 if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1333 return;
1334
1335 /*
1336 * At this point, we stop accepting input. To do this, we
1337 * disable the receive line status interrupts.
1338 */
1339 if (port->flags & ASYNC_INITIALIZED) {
1340 unsigned long flags;
1341 spin_lock_irqsave(&uport->lock, flags);
1342 uport->ops->stop_rx(uport);
1343 spin_unlock_irqrestore(&uport->lock, flags);
1344 /*
1345 * Before we drop DTR, make sure the UART transmitter
1346 * has completely drained; this is especially
1347 * important if there is a transmit FIFO!
1348 */
1349 uart_wait_until_sent(tty, uport->timeout);
1350 }
1351
1352 mutex_lock(&port->mutex);
1353 uart_shutdown(tty, state);
1354 uart_flush_buffer(tty);
1355
1356 tty_ldisc_flush(tty);
1357
1358 tty_port_tty_set(port, NULL);
1359 spin_lock_irqsave(&port->lock, flags);
1360 tty->closing = 0;
1361
1362 if (port->blocked_open) {
1363 spin_unlock_irqrestore(&port->lock, flags);
1364 if (port->close_delay)
1365 msleep_interruptible(
1366 jiffies_to_msecs(port->close_delay));
1367 spin_lock_irqsave(&port->lock, flags);
1368 } else if (!uart_console(uport)) {
1369 spin_unlock_irqrestore(&port->lock, flags);
1370 uart_change_pm(state, UART_PM_STATE_OFF);
1371 spin_lock_irqsave(&port->lock, flags);
1372 }
1373
1374 /*
1375 * Wake up anyone trying to open this port.
1376 */
1377 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1378 clear_bit(ASYNCB_CLOSING, &port->flags);
1379 spin_unlock_irqrestore(&port->lock, flags);
1380 wake_up_interruptible(&port->open_wait);
1381 wake_up_interruptible(&port->close_wait);
1382
1383 mutex_unlock(&port->mutex);
1384}
1385
1386static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1387{
1388 struct uart_state *state = tty->driver_data;
1389 struct uart_port *port = state->uart_port;
1390 unsigned long char_time, expire;
1391
1392 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1393 return;
1394
1395 /*
1396 * Set the check interval to be 1/5 of the estimated time to
1397 * send a single character, and make it at least 1. The check
1398 * interval should also be less than the timeout.
1399 *
1400 * Note: we have to use pretty tight timings here to satisfy
1401 * the NIST-PCTS.
1402 */
1403 char_time = (port->timeout - HZ/50) / port->fifosize;
1404 char_time = char_time / 5;
1405 if (char_time == 0)
1406 char_time = 1;
1407 if (timeout && timeout < char_time)
1408 char_time = timeout;
1409
1410 /*
1411 * If the transmitter hasn't cleared in twice the approximate
1412 * amount of time to send the entire FIFO, it probably won't
1413 * ever clear. This assumes the UART isn't doing flow
1414 * control, which is currently the case. Hence, if it ever
1415 * takes longer than port->timeout, this is probably due to a
1416 * UART bug of some kind. So, we clamp the timeout parameter at
1417 * 2*port->timeout.
1418 */
1419 if (timeout == 0 || timeout > 2 * port->timeout)
1420 timeout = 2 * port->timeout;
1421
1422 expire = jiffies + timeout;
1423
1424 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1425 port->line, jiffies, expire);
1426
1427 /*
1428 * Check whether the transmitter is empty every 'char_time'.
1429 * 'timeout' / 'expire' give us the maximum amount of time
1430 * we wait.
1431 */
1432 while (!port->ops->tx_empty(port)) {
1433 msleep_interruptible(jiffies_to_msecs(char_time));
1434 if (signal_pending(current))
1435 break;
1436 if (time_after(jiffies, expire))
1437 break;
1438 }
1439}
1440
1441/*
1442 * Calls to uart_hangup() are serialised by the tty_lock in
1443 * drivers/tty/tty_io.c:do_tty_hangup()
1444 * This runs from a workqueue and can sleep for a _short_ time only.
1445 */
1446static void uart_hangup(struct tty_struct *tty)
1447{
1448 struct uart_state *state = tty->driver_data;
1449 struct tty_port *port = &state->port;
1450 unsigned long flags;
1451
1452 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1453
1454 mutex_lock(&port->mutex);
1455 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1456 uart_flush_buffer(tty);
1457 uart_shutdown(tty, state);
1458 spin_lock_irqsave(&port->lock, flags);
1459 port->count = 0;
1460 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1461 spin_unlock_irqrestore(&port->lock, flags);
1462 tty_port_tty_set(port, NULL);
1463 if (!uart_console(state->uart_port))
1464 uart_change_pm(state, UART_PM_STATE_OFF);
1465 wake_up_interruptible(&port->open_wait);
1466 wake_up_interruptible(&port->delta_msr_wait);
1467 }
1468 mutex_unlock(&port->mutex);
1469}
1470
1471static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1472{
1473 return 0;
1474}
1475
1476static void uart_port_shutdown(struct tty_port *port)
1477{
1478 struct uart_state *state = container_of(port, struct uart_state, port);
1479 struct uart_port *uport = state->uart_port;
1480
1481 /*
1482 * clear delta_msr_wait queue to avoid mem leaks: we may free
1483 * the irq here so the queue might never be woken up. Note
1484 * that we won't end up waiting on delta_msr_wait again since
1485 * any outstanding file descriptors should be pointing at
1486 * hung_up_tty_fops now.
1487 */
1488 wake_up_interruptible(&port->delta_msr_wait);
1489
1490 /*
1491 * Free the IRQ and disable the port.
1492 */
1493 uport->ops->shutdown(uport);
1494
1495 /*
1496 * Ensure that the IRQ handler isn't running on another CPU.
1497 */
1498 synchronize_irq(uport->irq);
1499}
1500
1501static int uart_carrier_raised(struct tty_port *port)
1502{
1503 struct uart_state *state = container_of(port, struct uart_state, port);
1504 struct uart_port *uport = state->uart_port;
1505 int mctrl;
1506 spin_lock_irq(&uport->lock);
1507 uport->ops->enable_ms(uport);
1508 mctrl = uport->ops->get_mctrl(uport);
1509 spin_unlock_irq(&uport->lock);
1510 if (mctrl & TIOCM_CAR)
1511 return 1;
1512 return 0;
1513}
1514
1515static void uart_dtr_rts(struct tty_port *port, int onoff)
1516{
1517 struct uart_state *state = container_of(port, struct uart_state, port);
1518 struct uart_port *uport = state->uart_port;
1519
1520 if (onoff)
1521 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1522 else
1523 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1524}
1525
1526/*
1527 * Calls to uart_open are serialised by the tty_lock in
1528 * drivers/tty/tty_io.c:tty_open()
1529 * Note that if this fails, then uart_close() _will_ be called.
1530 *
1531 * In time, we want to scrap the "opening nonpresent ports"
1532 * behaviour and implement an alternative way for setserial
1533 * to set base addresses/ports/types. This will allow us to
1534 * get rid of a certain amount of extra tests.
1535 */
1536static int uart_open(struct tty_struct *tty, struct file *filp)
1537{
1538 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1539 int retval, line = tty->index;
1540 struct uart_state *state = drv->state + line;
1541 struct tty_port *port = &state->port;
1542
1543 pr_debug("uart_open(%d) called\n", line);
1544
1545 /*
1546 * We take the semaphore here to guarantee that we won't be re-entered
1547 * while allocating the state structure, or while we request any IRQs
1548 * that the driver may need. This also has the nice side-effect that
1549 * it delays the action of uart_hangup, so we can guarantee that
1550 * state->port.tty will always contain something reasonable.
1551 */
1552 if (mutex_lock_interruptible(&port->mutex)) {
1553 retval = -ERESTARTSYS;
1554 goto end;
1555 }
1556
1557 port->count++;
1558 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1559 retval = -ENXIO;
1560 goto err_dec_count;
1561 }
1562
1563 /*
1564 * Once we set tty->driver_data here, we are guaranteed that
1565 * uart_close() will decrement the driver module use count.
1566 * Any failures from here onwards should not touch the count.
1567 */
1568 tty->driver_data = state;
1569 state->uart_port->state = state;
1570 state->port.low_latency =
1571 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1572 tty_port_tty_set(port, tty);
1573
1574 /*
1575 * If the port is in the middle of closing, bail out now.
1576 */
1577 if (tty_hung_up_p(filp)) {
1578 retval = -EAGAIN;
1579 goto err_dec_count;
1580 }
1581
1582 /*
1583 * Start up the serial port.
1584 */
1585 retval = uart_startup(tty, state, 0);
1586
1587 /*
1588 * If we succeeded, wait until the port is ready.
1589 */
1590 mutex_unlock(&port->mutex);
1591 if (retval == 0)
1592 retval = tty_port_block_til_ready(port, tty, filp);
1593
1594end:
1595 return retval;
1596err_dec_count:
1597 port->count--;
1598 mutex_unlock(&port->mutex);
1599 goto end;
1600}
1601
1602static const char *uart_type(struct uart_port *port)
1603{
1604 const char *str = NULL;
1605
1606 if (port->ops->type)
1607 str = port->ops->type(port);
1608
1609 if (!str)
1610 str = "unknown";
1611
1612 return str;
1613}
1614
1615#ifdef CONFIG_PROC_FS
1616
1617static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1618{
1619 struct uart_state *state = drv->state + i;
1620 struct tty_port *port = &state->port;
1621 enum uart_pm_state pm_state;
1622 struct uart_port *uport = state->uart_port;
1623 char stat_buf[32];
1624 unsigned int status;
1625 int mmio;
1626
1627 if (!uport)
1628 return;
1629
1630 mmio = uport->iotype >= UPIO_MEM;
1631 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1632 uport->line, uart_type(uport),
1633 mmio ? "mmio:0x" : "port:",
1634 mmio ? (unsigned long long)uport->mapbase
1635 : (unsigned long long)uport->iobase,
1636 uport->irq);
1637
1638 if (uport->type == PORT_UNKNOWN) {
1639 seq_putc(m, '\n');
1640 return;
1641 }
1642
1643 if (capable(CAP_SYS_ADMIN)) {
1644 mutex_lock(&port->mutex);
1645 pm_state = state->pm_state;
1646 if (pm_state != UART_PM_STATE_ON)
1647 uart_change_pm(state, UART_PM_STATE_ON);
1648 spin_lock_irq(&uport->lock);
1649 status = uport->ops->get_mctrl(uport);
1650 spin_unlock_irq(&uport->lock);
1651 if (pm_state != UART_PM_STATE_ON)
1652 uart_change_pm(state, pm_state);
1653 mutex_unlock(&port->mutex);
1654
1655 seq_printf(m, " tx:%d rx:%d",
1656 uport->icount.tx, uport->icount.rx);
1657 if (uport->icount.frame)
1658 seq_printf(m, " fe:%d",
1659 uport->icount.frame);
1660 if (uport->icount.parity)
1661 seq_printf(m, " pe:%d",
1662 uport->icount.parity);
1663 if (uport->icount.brk)
1664 seq_printf(m, " brk:%d",
1665 uport->icount.brk);
1666 if (uport->icount.overrun)
1667 seq_printf(m, " oe:%d",
1668 uport->icount.overrun);
1669
1670#define INFOBIT(bit, str) \
1671 if (uport->mctrl & (bit)) \
1672 strncat(stat_buf, (str), sizeof(stat_buf) - \
1673 strlen(stat_buf) - 2)
1674#define STATBIT(bit, str) \
1675 if (status & (bit)) \
1676 strncat(stat_buf, (str), sizeof(stat_buf) - \
1677 strlen(stat_buf) - 2)
1678
1679 stat_buf[0] = '\0';
1680 stat_buf[1] = '\0';
1681 INFOBIT(TIOCM_RTS, "|RTS");
1682 STATBIT(TIOCM_CTS, "|CTS");
1683 INFOBIT(TIOCM_DTR, "|DTR");
1684 STATBIT(TIOCM_DSR, "|DSR");
1685 STATBIT(TIOCM_CAR, "|CD");
1686 STATBIT(TIOCM_RNG, "|RI");
1687 if (stat_buf[0])
1688 stat_buf[0] = ' ';
1689
1690 seq_puts(m, stat_buf);
1691 }
1692 seq_putc(m, '\n');
1693#undef STATBIT
1694#undef INFOBIT
1695}
1696
1697static int uart_proc_show(struct seq_file *m, void *v)
1698{
1699 struct tty_driver *ttydrv = m->private;
1700 struct uart_driver *drv = ttydrv->driver_state;
1701 int i;
1702
1703 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1704 "", "", "");
1705 for (i = 0; i < drv->nr; i++)
1706 uart_line_info(m, drv, i);
1707 return 0;
1708}
1709
1710static int uart_proc_open(struct inode *inode, struct file *file)
1711{
1712 return single_open(file, uart_proc_show, PDE_DATA(inode));
1713}
1714
1715static const struct file_operations uart_proc_fops = {
1716 .owner = THIS_MODULE,
1717 .open = uart_proc_open,
1718 .read = seq_read,
1719 .llseek = seq_lseek,
1720 .release = single_release,
1721};
1722#endif
1723
1724#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1725/*
1726 * uart_console_write - write a console message to a serial port
1727 * @port: the port to write the message
1728 * @s: array of characters
1729 * @count: number of characters in string to write
1730 * @write: function to write character to port
1731 */
1732void uart_console_write(struct uart_port *port, const char *s,
1733 unsigned int count,
1734 void (*putchar)(struct uart_port *, int))
1735{
1736 unsigned int i;
1737
1738 for (i = 0; i < count; i++, s++) {
1739 if (*s == '\n')
1740 putchar(port, '\r');
1741 putchar(port, *s);
1742 }
1743}
1744EXPORT_SYMBOL_GPL(uart_console_write);
1745
1746/*
1747 * Check whether an invalid uart number has been specified, and
1748 * if so, search for the first available port that does have
1749 * console support.
1750 */
1751struct uart_port * __init
1752uart_get_console(struct uart_port *ports, int nr, struct console *co)
1753{
1754 int idx = co->index;
1755
1756 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1757 ports[idx].membase == NULL))
1758 for (idx = 0; idx < nr; idx++)
1759 if (ports[idx].iobase != 0 ||
1760 ports[idx].membase != NULL)
1761 break;
1762
1763 co->index = idx;
1764
1765 return ports + idx;
1766}
1767
1768/**
1769 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1770 * @options: pointer to option string
1771 * @baud: pointer to an 'int' variable for the baud rate.
1772 * @parity: pointer to an 'int' variable for the parity.
1773 * @bits: pointer to an 'int' variable for the number of data bits.
1774 * @flow: pointer to an 'int' variable for the flow control character.
1775 *
1776 * uart_parse_options decodes a string containing the serial console
1777 * options. The format of the string is <baud><parity><bits><flow>,
1778 * eg: 115200n8r
1779 */
1780void
1781uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1782{
1783 char *s = options;
1784
1785 *baud = simple_strtoul(s, NULL, 10);
1786 while (*s >= '0' && *s <= '9')
1787 s++;
1788 if (*s)
1789 *parity = *s++;
1790 if (*s)
1791 *bits = *s++ - '0';
1792 if (*s)
1793 *flow = *s;
1794}
1795EXPORT_SYMBOL_GPL(uart_parse_options);
1796
1797struct baud_rates {
1798 unsigned int rate;
1799 unsigned int cflag;
1800};
1801
1802static const struct baud_rates baud_rates[] = {
1803 { 921600, B921600 },
1804 { 460800, B460800 },
1805 { 230400, B230400 },
1806 { 115200, B115200 },
1807 { 57600, B57600 },
1808 { 38400, B38400 },
1809 { 19200, B19200 },
1810 { 9600, B9600 },
1811 { 4800, B4800 },
1812 { 2400, B2400 },
1813 { 1200, B1200 },
1814 { 0, B38400 }
1815};
1816
1817/**
1818 * uart_set_options - setup the serial console parameters
1819 * @port: pointer to the serial ports uart_port structure
1820 * @co: console pointer
1821 * @baud: baud rate
1822 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1823 * @bits: number of data bits
1824 * @flow: flow control character - 'r' (rts)
1825 */
1826int
1827uart_set_options(struct uart_port *port, struct console *co,
1828 int baud, int parity, int bits, int flow)
1829{
1830 struct ktermios termios;
1831 static struct ktermios dummy;
1832 int i;
1833
1834 /*
1835 * Ensure that the serial console lock is initialised
1836 * early.
1837 * If this port is a console, then the spinlock is already
1838 * initialised.
1839 */
1840 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1841 spin_lock_init(&port->lock);
1842 lockdep_set_class(&port->lock, &port_lock_key);
1843 }
1844
1845 memset(&termios, 0, sizeof(struct ktermios));
1846
1847 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1848
1849 /*
1850 * Construct a cflag setting.
1851 */
1852 for (i = 0; baud_rates[i].rate; i++)
1853 if (baud_rates[i].rate <= baud)
1854 break;
1855
1856 termios.c_cflag |= baud_rates[i].cflag;
1857
1858 if (bits == 7)
1859 termios.c_cflag |= CS7;
1860 else
1861 termios.c_cflag |= CS8;
1862
1863 switch (parity) {
1864 case 'o': case 'O':
1865 termios.c_cflag |= PARODD;
1866 /*fall through*/
1867 case 'e': case 'E':
1868 termios.c_cflag |= PARENB;
1869 break;
1870 }
1871
1872 if (flow == 'r')
1873 termios.c_cflag |= CRTSCTS;
1874
1875 /*
1876 * some uarts on other side don't support no flow control.
1877 * So we set * DTR in host uart to make them happy
1878 */
1879 port->mctrl |= TIOCM_DTR;
1880
1881 port->ops->set_termios(port, &termios, &dummy);
1882 /*
1883 * Allow the setting of the UART parameters with a NULL console
1884 * too:
1885 */
1886 if (co)
1887 co->cflag = termios.c_cflag;
1888
1889 return 0;
1890}
1891EXPORT_SYMBOL_GPL(uart_set_options);
1892#endif /* CONFIG_SERIAL_CORE_CONSOLE */
1893
1894/**
1895 * uart_change_pm - set power state of the port
1896 *
1897 * @state: port descriptor
1898 * @pm_state: new state
1899 *
1900 * Locking: port->mutex has to be held
1901 */
1902static void uart_change_pm(struct uart_state *state,
1903 enum uart_pm_state pm_state)
1904{
1905 struct uart_port *port = state->uart_port;
1906
1907 if (state->pm_state != pm_state) {
1908 if (port->ops->pm)
1909 port->ops->pm(port, pm_state, state->pm_state);
1910 state->pm_state = pm_state;
1911 }
1912}
1913
1914struct uart_match {
1915 struct uart_port *port;
1916 struct uart_driver *driver;
1917};
1918
1919static int serial_match_port(struct device *dev, void *data)
1920{
1921 struct uart_match *match = data;
1922 struct tty_driver *tty_drv = match->driver->tty_driver;
1923 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1924 match->port->line;
1925
1926 return dev->devt == devt; /* Actually, only one tty per port */
1927}
1928
1929int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1930{
1931 struct uart_state *state = drv->state + uport->line;
1932 struct tty_port *port = &state->port;
1933 struct device *tty_dev;
1934 struct uart_match match = {uport, drv};
1935
1936 mutex_lock(&port->mutex);
1937
1938 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1939 if (device_may_wakeup(tty_dev)) {
1940 if (!enable_irq_wake(uport->irq))
1941 uport->irq_wake = 1;
1942 put_device(tty_dev);
1943 mutex_unlock(&port->mutex);
1944 return 0;
1945 }
1946 put_device(tty_dev);
1947
1948 if (console_suspend_enabled || !uart_console(uport))
1949 uport->suspended = 1;
1950
1951 if (port->flags & ASYNC_INITIALIZED) {
1952 const struct uart_ops *ops = uport->ops;
1953 int tries;
1954
1955 if (console_suspend_enabled || !uart_console(uport)) {
1956 set_bit(ASYNCB_SUSPENDED, &port->flags);
1957 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1958
1959 spin_lock_irq(&uport->lock);
1960 ops->stop_tx(uport);
1961 ops->set_mctrl(uport, 0);
1962 ops->stop_rx(uport);
1963 spin_unlock_irq(&uport->lock);
1964 }
1965
1966 /*
1967 * Wait for the transmitter to empty.
1968 */
1969 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1970 msleep(10);
1971 if (!tries)
1972 printk(KERN_ERR "%s%s%s%d: Unable to drain "
1973 "transmitter\n",
1974 uport->dev ? dev_name(uport->dev) : "",
1975 uport->dev ? ": " : "",
1976 drv->dev_name,
1977 drv->tty_driver->name_base + uport->line);
1978
1979 if (console_suspend_enabled || !uart_console(uport))
1980 ops->shutdown(uport);
1981 }
1982
1983 /*
1984 * Disable the console device before suspending.
1985 */
1986 if (console_suspend_enabled && uart_console(uport))
1987 console_stop(uport->cons);
1988
1989 if (console_suspend_enabled || !uart_console(uport))
1990 uart_change_pm(state, UART_PM_STATE_OFF);
1991
1992 mutex_unlock(&port->mutex);
1993
1994 return 0;
1995}
1996
1997int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1998{
1999 struct uart_state *state = drv->state + uport->line;
2000 struct tty_port *port = &state->port;
2001 struct device *tty_dev;
2002 struct uart_match match = {uport, drv};
2003 struct ktermios termios;
2004
2005 mutex_lock(&port->mutex);
2006
2007 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2008 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2009 if (uport->irq_wake) {
2010 disable_irq_wake(uport->irq);
2011 uport->irq_wake = 0;
2012 }
2013 put_device(tty_dev);
2014 mutex_unlock(&port->mutex);
2015 return 0;
2016 }
2017 put_device(tty_dev);
2018 uport->suspended = 0;
2019
2020 /*
2021 * Re-enable the console device after suspending.
2022 */
2023 if (uart_console(uport)) {
2024 /*
2025 * First try to use the console cflag setting.
2026 */
2027 memset(&termios, 0, sizeof(struct ktermios));
2028 termios.c_cflag = uport->cons->cflag;
2029
2030 /*
2031 * If that's unset, use the tty termios setting.
2032 */
2033 if (port->tty && termios.c_cflag == 0)
2034 termios = port->tty->termios;
2035
2036 if (console_suspend_enabled)
2037 uart_change_pm(state, UART_PM_STATE_ON);
2038 uport->ops->set_termios(uport, &termios, NULL);
2039 if (console_suspend_enabled)
2040 console_start(uport->cons);
2041 }
2042
2043 if (port->flags & ASYNC_SUSPENDED) {
2044 const struct uart_ops *ops = uport->ops;
2045 int ret;
2046
2047 uart_change_pm(state, UART_PM_STATE_ON);
2048 spin_lock_irq(&uport->lock);
2049 ops->set_mctrl(uport, 0);
2050 spin_unlock_irq(&uport->lock);
2051 if (console_suspend_enabled || !uart_console(uport)) {
2052 /* Protected by port mutex for now */
2053 struct tty_struct *tty = port->tty;
2054 ret = ops->startup(uport);
2055 if (ret == 0) {
2056 if (tty)
2057 uart_change_speed(tty, state, NULL);
2058 spin_lock_irq(&uport->lock);
2059 ops->set_mctrl(uport, uport->mctrl);
2060 ops->start_tx(uport);
2061 spin_unlock_irq(&uport->lock);
2062 set_bit(ASYNCB_INITIALIZED, &port->flags);
2063 } else {
2064 /*
2065 * Failed to resume - maybe hardware went away?
2066 * Clear the "initialized" flag so we won't try
2067 * to call the low level drivers shutdown method.
2068 */
2069 uart_shutdown(tty, state);
2070 }
2071 }
2072
2073 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2074 }
2075
2076 mutex_unlock(&port->mutex);
2077
2078 return 0;
2079}
2080
2081static inline void
2082uart_report_port(struct uart_driver *drv, struct uart_port *port)
2083{
2084 char address[64];
2085
2086 switch (port->iotype) {
2087 case UPIO_PORT:
2088 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2089 break;
2090 case UPIO_HUB6:
2091 snprintf(address, sizeof(address),
2092 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2093 break;
2094 case UPIO_MEM:
2095 case UPIO_MEM32:
2096 case UPIO_AU:
2097 case UPIO_TSI:
2098 snprintf(address, sizeof(address),
2099 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2100 break;
2101 default:
2102 strlcpy(address, "*unknown*", sizeof(address));
2103 break;
2104 }
2105
2106 printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2107 port->dev ? dev_name(port->dev) : "",
2108 port->dev ? ": " : "",
2109 drv->dev_name,
2110 drv->tty_driver->name_base + port->line,
2111 address, port->irq, port->uartclk / 16, uart_type(port));
2112}
2113
2114static void
2115uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2116 struct uart_port *port)
2117{
2118 unsigned int flags;
2119
2120 /*
2121 * If there isn't a port here, don't do anything further.
2122 */
2123 if (!port->iobase && !port->mapbase && !port->membase)
2124 return;
2125
2126 /*
2127 * Now do the auto configuration stuff. Note that config_port
2128 * is expected to claim the resources and map the port for us.
2129 */
2130 flags = 0;
2131 if (port->flags & UPF_AUTO_IRQ)
2132 flags |= UART_CONFIG_IRQ;
2133 if (port->flags & UPF_BOOT_AUTOCONF) {
2134 if (!(port->flags & UPF_FIXED_TYPE)) {
2135 port->type = PORT_UNKNOWN;
2136 flags |= UART_CONFIG_TYPE;
2137 }
2138 port->ops->config_port(port, flags);
2139 }
2140
2141 if (port->type != PORT_UNKNOWN) {
2142 unsigned long flags;
2143
2144 uart_report_port(drv, port);
2145
2146 /* Power up port for set_mctrl() */
2147 uart_change_pm(state, UART_PM_STATE_ON);
2148
2149 /*
2150 * Ensure that the modem control lines are de-activated.
2151 * keep the DTR setting that is set in uart_set_options()
2152 * We probably don't need a spinlock around this, but
2153 */
2154 spin_lock_irqsave(&port->lock, flags);
2155 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2156 spin_unlock_irqrestore(&port->lock, flags);
2157
2158 /*
2159 * If this driver supports console, and it hasn't been
2160 * successfully registered yet, try to re-register it.
2161 * It may be that the port was not available.
2162 */
2163 if (port->cons && !(port->cons->flags & CON_ENABLED))
2164 register_console(port->cons);
2165
2166 /*
2167 * Power down all ports by default, except the
2168 * console if we have one.
2169 */
2170 if (!uart_console(port))
2171 uart_change_pm(state, UART_PM_STATE_OFF);
2172 }
2173}
2174
2175#ifdef CONFIG_CONSOLE_POLL
2176
2177static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2178{
2179 struct uart_driver *drv = driver->driver_state;
2180 struct uart_state *state = drv->state + line;
2181 struct uart_port *port;
2182 int baud = 9600;
2183 int bits = 8;
2184 int parity = 'n';
2185 int flow = 'n';
2186 int ret;
2187
2188 if (!state || !state->uart_port)
2189 return -1;
2190
2191 port = state->uart_port;
2192 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2193 return -1;
2194
2195 if (port->ops->poll_init) {
2196 struct tty_port *tport = &state->port;
2197
2198 ret = 0;
2199 mutex_lock(&tport->mutex);
2200 /*
2201 * We don't set ASYNCB_INITIALIZED as we only initialized the
2202 * hw, e.g. state->xmit is still uninitialized.
2203 */
2204 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2205 ret = port->ops->poll_init(port);
2206 mutex_unlock(&tport->mutex);
2207 if (ret)
2208 return ret;
2209 }
2210
2211 if (options) {
2212 uart_parse_options(options, &baud, &parity, &bits, &flow);
2213 return uart_set_options(port, NULL, baud, parity, bits, flow);
2214 }
2215
2216 return 0;
2217}
2218
2219static int uart_poll_get_char(struct tty_driver *driver, int line)
2220{
2221 struct uart_driver *drv = driver->driver_state;
2222 struct uart_state *state = drv->state + line;
2223 struct uart_port *port;
2224
2225 if (!state || !state->uart_port)
2226 return -1;
2227
2228 port = state->uart_port;
2229 return port->ops->poll_get_char(port);
2230}
2231
2232static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2233{
2234 struct uart_driver *drv = driver->driver_state;
2235 struct uart_state *state = drv->state + line;
2236 struct uart_port *port;
2237
2238 if (!state || !state->uart_port)
2239 return;
2240
2241 port = state->uart_port;
2242 port->ops->poll_put_char(port, ch);
2243}
2244#endif
2245
2246static const struct tty_operations uart_ops = {
2247 .open = uart_open,
2248 .close = uart_close,
2249 .write = uart_write,
2250 .put_char = uart_put_char,
2251 .flush_chars = uart_flush_chars,
2252 .write_room = uart_write_room,
2253 .chars_in_buffer= uart_chars_in_buffer,
2254 .flush_buffer = uart_flush_buffer,
2255 .ioctl = uart_ioctl,
2256 .throttle = uart_throttle,
2257 .unthrottle = uart_unthrottle,
2258 .send_xchar = uart_send_xchar,
2259 .set_termios = uart_set_termios,
2260 .set_ldisc = uart_set_ldisc,
2261 .stop = uart_stop,
2262 .start = uart_start,
2263 .hangup = uart_hangup,
2264 .break_ctl = uart_break_ctl,
2265 .wait_until_sent= uart_wait_until_sent,
2266#ifdef CONFIG_PROC_FS
2267 .proc_fops = &uart_proc_fops,
2268#endif
2269 .tiocmget = uart_tiocmget,
2270 .tiocmset = uart_tiocmset,
2271 .get_icount = uart_get_icount,
2272#ifdef CONFIG_CONSOLE_POLL
2273 .poll_init = uart_poll_init,
2274 .poll_get_char = uart_poll_get_char,
2275 .poll_put_char = uart_poll_put_char,
2276#endif
2277};
2278
2279static const struct tty_port_operations uart_port_ops = {
2280 .activate = uart_port_activate,
2281 .shutdown = uart_port_shutdown,
2282 .carrier_raised = uart_carrier_raised,
2283 .dtr_rts = uart_dtr_rts,
2284};
2285
2286/**
2287 * uart_register_driver - register a driver with the uart core layer
2288 * @drv: low level driver structure
2289 *
2290 * Register a uart driver with the core driver. We in turn register
2291 * with the tty layer, and initialise the core driver per-port state.
2292 *
2293 * We have a proc file in /proc/tty/driver which is named after the
2294 * normal driver.
2295 *
2296 * drv->port should be NULL, and the per-port structures should be
2297 * registered using uart_add_one_port after this call has succeeded.
2298 */
2299int uart_register_driver(struct uart_driver *drv)
2300{
2301 struct tty_driver *normal;
2302 int i, retval;
2303
2304 BUG_ON(drv->state);
2305
2306 /*
2307 * Maybe we should be using a slab cache for this, especially if
2308 * we have a large number of ports to handle.
2309 */
2310 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2311 if (!drv->state)
2312 goto out;
2313
2314 normal = alloc_tty_driver(drv->nr);
2315 if (!normal)
2316 goto out_kfree;
2317
2318 drv->tty_driver = normal;
2319
2320 normal->driver_name = drv->driver_name;
2321 normal->name = drv->dev_name;
2322 normal->major = drv->major;
2323 normal->minor_start = drv->minor;
2324 normal->type = TTY_DRIVER_TYPE_SERIAL;
2325 normal->subtype = SERIAL_TYPE_NORMAL;
2326 normal->init_termios = tty_std_termios;
2327 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2328 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2329 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2330 normal->driver_state = drv;
2331 tty_set_operations(normal, &uart_ops);
2332
2333 /*
2334 * Initialise the UART state(s).
2335 */
2336 for (i = 0; i < drv->nr; i++) {
2337 struct uart_state *state = drv->state + i;
2338 struct tty_port *port = &state->port;
2339
2340 tty_port_init(port);
2341 port->ops = &uart_port_ops;
2342 port->close_delay = HZ / 2; /* .5 seconds */
2343 port->closing_wait = 30 * HZ;/* 30 seconds */
2344 }
2345
2346 retval = tty_register_driver(normal);
2347 if (retval >= 0)
2348 return retval;
2349
2350 for (i = 0; i < drv->nr; i++)
2351 tty_port_destroy(&drv->state[i].port);
2352 put_tty_driver(normal);
2353out_kfree:
2354 kfree(drv->state);
2355out:
2356 return -ENOMEM;
2357}
2358
2359/**
2360 * uart_unregister_driver - remove a driver from the uart core layer
2361 * @drv: low level driver structure
2362 *
2363 * Remove all references to a driver from the core driver. The low
2364 * level driver must have removed all its ports via the
2365 * uart_remove_one_port() if it registered them with uart_add_one_port().
2366 * (ie, drv->port == NULL)
2367 */
2368void uart_unregister_driver(struct uart_driver *drv)
2369{
2370 struct tty_driver *p = drv->tty_driver;
2371 unsigned int i;
2372
2373 tty_unregister_driver(p);
2374 put_tty_driver(p);
2375 for (i = 0; i < drv->nr; i++)
2376 tty_port_destroy(&drv->state[i].port);
2377 kfree(drv->state);
2378 drv->state = NULL;
2379 drv->tty_driver = NULL;
2380}
2381
2382struct tty_driver *uart_console_device(struct console *co, int *index)
2383{
2384 struct uart_driver *p = co->data;
2385 *index = co->index;
2386 return p->tty_driver;
2387}
2388
2389static ssize_t uart_get_attr_uartclk(struct device *dev,
2390 struct device_attribute *attr, char *buf)
2391{
2392 struct serial_struct tmp;
2393 struct tty_port *port = dev_get_drvdata(dev);
2394
2395 uart_get_info(port, &tmp);
2396 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2397}
2398
2399static ssize_t uart_get_attr_type(struct device *dev,
2400 struct device_attribute *attr, char *buf)
2401{
2402 struct serial_struct tmp;
2403 struct tty_port *port = dev_get_drvdata(dev);
2404
2405 uart_get_info(port, &tmp);
2406 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2407}
2408static ssize_t uart_get_attr_line(struct device *dev,
2409 struct device_attribute *attr, char *buf)
2410{
2411 struct serial_struct tmp;
2412 struct tty_port *port = dev_get_drvdata(dev);
2413
2414 uart_get_info(port, &tmp);
2415 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2416}
2417
2418static ssize_t uart_get_attr_port(struct device *dev,
2419 struct device_attribute *attr, char *buf)
2420{
2421 struct serial_struct tmp;
2422 struct tty_port *port = dev_get_drvdata(dev);
2423 unsigned long ioaddr;
2424
2425 uart_get_info(port, &tmp);
2426 ioaddr = tmp.port;
2427 if (HIGH_BITS_OFFSET)
2428 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2429 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2430}
2431
2432static ssize_t uart_get_attr_irq(struct device *dev,
2433 struct device_attribute *attr, char *buf)
2434{
2435 struct serial_struct tmp;
2436 struct tty_port *port = dev_get_drvdata(dev);
2437
2438 uart_get_info(port, &tmp);
2439 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2440}
2441
2442static ssize_t uart_get_attr_flags(struct device *dev,
2443 struct device_attribute *attr, char *buf)
2444{
2445 struct serial_struct tmp;
2446 struct tty_port *port = dev_get_drvdata(dev);
2447
2448 uart_get_info(port, &tmp);
2449 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2450}
2451
2452static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2453 struct device_attribute *attr, char *buf)
2454{
2455 struct serial_struct tmp;
2456 struct tty_port *port = dev_get_drvdata(dev);
2457
2458 uart_get_info(port, &tmp);
2459 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2460}
2461
2462
2463static ssize_t uart_get_attr_close_delay(struct device *dev,
2464 struct device_attribute *attr, char *buf)
2465{
2466 struct serial_struct tmp;
2467 struct tty_port *port = dev_get_drvdata(dev);
2468
2469 uart_get_info(port, &tmp);
2470 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2471}
2472
2473
2474static ssize_t uart_get_attr_closing_wait(struct device *dev,
2475 struct device_attribute *attr, char *buf)
2476{
2477 struct serial_struct tmp;
2478 struct tty_port *port = dev_get_drvdata(dev);
2479
2480 uart_get_info(port, &tmp);
2481 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2482}
2483
2484static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2485 struct device_attribute *attr, char *buf)
2486{
2487 struct serial_struct tmp;
2488 struct tty_port *port = dev_get_drvdata(dev);
2489
2490 uart_get_info(port, &tmp);
2491 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2492}
2493
2494static ssize_t uart_get_attr_io_type(struct device *dev,
2495 struct device_attribute *attr, char *buf)
2496{
2497 struct serial_struct tmp;
2498 struct tty_port *port = dev_get_drvdata(dev);
2499
2500 uart_get_info(port, &tmp);
2501 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2502}
2503
2504static ssize_t uart_get_attr_iomem_base(struct device *dev,
2505 struct device_attribute *attr, char *buf)
2506{
2507 struct serial_struct tmp;
2508 struct tty_port *port = dev_get_drvdata(dev);
2509
2510 uart_get_info(port, &tmp);
2511 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2512}
2513
2514static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2515 struct device_attribute *attr, char *buf)
2516{
2517 struct serial_struct tmp;
2518 struct tty_port *port = dev_get_drvdata(dev);
2519
2520 uart_get_info(port, &tmp);
2521 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2522}
2523
2524static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2525static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2526static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2527static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2528static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2529static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2530static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2531static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2532static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2533static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2534static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2535static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2536static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2537
2538static struct attribute *tty_dev_attrs[] = {
2539 &dev_attr_type.attr,
2540 &dev_attr_line.attr,
2541 &dev_attr_port.attr,
2542 &dev_attr_irq.attr,
2543 &dev_attr_flags.attr,
2544 &dev_attr_xmit_fifo_size.attr,
2545 &dev_attr_uartclk.attr,
2546 &dev_attr_close_delay.attr,
2547 &dev_attr_closing_wait.attr,
2548 &dev_attr_custom_divisor.attr,
2549 &dev_attr_io_type.attr,
2550 &dev_attr_iomem_base.attr,
2551 &dev_attr_iomem_reg_shift.attr,
2552 NULL,
2553 };
2554
2555static const struct attribute_group tty_dev_attr_group = {
2556 .attrs = tty_dev_attrs,
2557 };
2558
2559static const struct attribute_group *tty_dev_attr_groups[] = {
2560 &tty_dev_attr_group,
2561 NULL
2562 };
2563
2564
2565/**
2566 * uart_add_one_port - attach a driver-defined port structure
2567 * @drv: pointer to the uart low level driver structure for this port
2568 * @uport: uart port structure to use for this port.
2569 *
2570 * This allows the driver to register its own uart_port structure
2571 * with the core driver. The main purpose is to allow the low
2572 * level uart drivers to expand uart_port, rather than having yet
2573 * more levels of structures.
2574 */
2575int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2576{
2577 struct uart_state *state;
2578 struct tty_port *port;
2579 int ret = 0;
2580 struct device *tty_dev;
2581
2582 BUG_ON(in_interrupt());
2583
2584 if (uport->line >= drv->nr)
2585 return -EINVAL;
2586
2587 state = drv->state + uport->line;
2588 port = &state->port;
2589
2590 mutex_lock(&port_mutex);
2591 mutex_lock(&port->mutex);
2592 if (state->uart_port) {
2593 ret = -EINVAL;
2594 goto out;
2595 }
2596
2597 state->uart_port = uport;
2598 state->pm_state = UART_PM_STATE_UNDEFINED;
2599
2600 uport->cons = drv->cons;
2601 uport->state = state;
2602
2603 /*
2604 * If this port is a console, then the spinlock is already
2605 * initialised.
2606 */
2607 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2608 spin_lock_init(&uport->lock);
2609 lockdep_set_class(&uport->lock, &port_lock_key);
2610 }
2611
2612 uart_configure_port(drv, state, uport);
2613
2614 /*
2615 * Register the port whether it's detected or not. This allows
2616 * setserial to be used to alter this port's parameters.
2617 */
2618 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2619 uport->line, uport->dev, port, tty_dev_attr_groups);
2620 if (likely(!IS_ERR(tty_dev))) {
2621 device_set_wakeup_capable(tty_dev, 1);
2622 } else {
2623 printk(KERN_ERR "Cannot register tty device on line %d\n",
2624 uport->line);
2625 }
2626
2627 /*
2628 * Ensure UPF_DEAD is not set.
2629 */
2630 uport->flags &= ~UPF_DEAD;
2631
2632 out:
2633 mutex_unlock(&port->mutex);
2634 mutex_unlock(&port_mutex);
2635
2636 return ret;
2637}
2638
2639/**
2640 * uart_remove_one_port - detach a driver defined port structure
2641 * @drv: pointer to the uart low level driver structure for this port
2642 * @uport: uart port structure for this port
2643 *
2644 * This unhooks (and hangs up) the specified port structure from the
2645 * core driver. No further calls will be made to the low-level code
2646 * for this port.
2647 */
2648int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2649{
2650 struct uart_state *state = drv->state + uport->line;
2651 struct tty_port *port = &state->port;
2652 struct tty_struct *tty;
2653 int ret = 0;
2654
2655 BUG_ON(in_interrupt());
2656
2657 if (state->uart_port != uport)
2658 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2659 state->uart_port, uport);
2660
2661 mutex_lock(&port_mutex);
2662
2663 /*
2664 * Mark the port "dead" - this prevents any opens from
2665 * succeeding while we shut down the port.
2666 */
2667 mutex_lock(&port->mutex);
2668 if (!state->uart_port) {
2669 mutex_unlock(&port->mutex);
2670 ret = -EINVAL;
2671 goto out;
2672 }
2673 uport->flags |= UPF_DEAD;
2674 mutex_unlock(&port->mutex);
2675
2676 /*
2677 * Remove the devices from the tty layer
2678 */
2679 tty_unregister_device(drv->tty_driver, uport->line);
2680
2681 tty = tty_port_tty_get(port);
2682 if (tty) {
2683 tty_vhangup(port->tty);
2684 tty_kref_put(tty);
2685 }
2686
2687 /*
2688 * If the port is used as a console, unregister it
2689 */
2690 if (uart_console(uport))
2691 unregister_console(uport->cons);
2692
2693 /*
2694 * Free the port IO and memory resources, if any.
2695 */
2696 if (uport->type != PORT_UNKNOWN)
2697 uport->ops->release_port(uport);
2698
2699 /*
2700 * Indicate that there isn't a port here anymore.
2701 */
2702 uport->type = PORT_UNKNOWN;
2703
2704 state->uart_port = NULL;
2705out:
2706 mutex_unlock(&port_mutex);
2707
2708 return ret;
2709}
2710
2711/*
2712 * Are the two ports equivalent?
2713 */
2714int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2715{
2716 if (port1->iotype != port2->iotype)
2717 return 0;
2718
2719 switch (port1->iotype) {
2720 case UPIO_PORT:
2721 return (port1->iobase == port2->iobase);
2722 case UPIO_HUB6:
2723 return (port1->iobase == port2->iobase) &&
2724 (port1->hub6 == port2->hub6);
2725 case UPIO_MEM:
2726 case UPIO_MEM32:
2727 case UPIO_AU:
2728 case UPIO_TSI:
2729 return (port1->mapbase == port2->mapbase);
2730 }
2731 return 0;
2732}
2733EXPORT_SYMBOL(uart_match_port);
2734
2735/**
2736 * uart_handle_dcd_change - handle a change of carrier detect state
2737 * @uport: uart_port structure for the open port
2738 * @status: new carrier detect status, nonzero if active
2739 */
2740void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2741{
2742 struct tty_port *port = &uport->state->port;
2743 struct tty_struct *tty = port->tty;
2744 struct tty_ldisc *ld = tty ? tty_ldisc_ref(tty) : NULL;
2745
2746 if (ld) {
2747 if (ld->ops->dcd_change)
2748 ld->ops->dcd_change(tty, status);
2749 tty_ldisc_deref(ld);
2750 }
2751
2752 uport->icount.dcd++;
2753
2754 if (port->flags & ASYNC_CHECK_CD) {
2755 if (status)
2756 wake_up_interruptible(&port->open_wait);
2757 else if (tty)
2758 tty_hangup(tty);
2759 }
2760}
2761EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2762
2763/**
2764 * uart_handle_cts_change - handle a change of clear-to-send state
2765 * @uport: uart_port structure for the open port
2766 * @status: new clear to send status, nonzero if active
2767 */
2768void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2769{
2770 struct tty_port *port = &uport->state->port;
2771 struct tty_struct *tty = port->tty;
2772
2773 uport->icount.cts++;
2774
2775 if (tty_port_cts_enabled(port)) {
2776 if (tty->hw_stopped) {
2777 if (status) {
2778 tty->hw_stopped = 0;
2779 uport->ops->start_tx(uport);
2780 uart_write_wakeup(uport);
2781 }
2782 } else {
2783 if (!status) {
2784 tty->hw_stopped = 1;
2785 uport->ops->stop_tx(uport);
2786 }
2787 }
2788 }
2789}
2790EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2791
2792/**
2793 * uart_insert_char - push a char to the uart layer
2794 *
2795 * User is responsible to call tty_flip_buffer_push when they are done with
2796 * insertion.
2797 *
2798 * @port: corresponding port
2799 * @status: state of the serial port RX buffer (LSR for 8250)
2800 * @overrun: mask of overrun bits in @status
2801 * @ch: character to push
2802 * @flag: flag for the character (see TTY_NORMAL and friends)
2803 */
2804void uart_insert_char(struct uart_port *port, unsigned int status,
2805 unsigned int overrun, unsigned int ch, unsigned int flag)
2806{
2807 struct tty_port *tport = &port->state->port;
2808
2809 if ((status & port->ignore_status_mask & ~overrun) == 0)
2810 if (tty_insert_flip_char(tport, ch, flag) == 0)
2811 ++port->icount.buf_overrun;
2812
2813 /*
2814 * Overrun is special. Since it's reported immediately,
2815 * it doesn't affect the current character.
2816 */
2817 if (status & ~port->ignore_status_mask & overrun)
2818 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2819 ++port->icount.buf_overrun;
2820}
2821EXPORT_SYMBOL_GPL(uart_insert_char);
2822
2823EXPORT_SYMBOL(uart_write_wakeup);
2824EXPORT_SYMBOL(uart_register_driver);
2825EXPORT_SYMBOL(uart_unregister_driver);
2826EXPORT_SYMBOL(uart_suspend_port);
2827EXPORT_SYMBOL(uart_resume_port);
2828EXPORT_SYMBOL(uart_add_one_port);
2829EXPORT_SYMBOL(uart_remove_one_port);
2830
2831MODULE_DESCRIPTION("Serial driver core");
2832MODULE_LICENSE("GPL");