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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/of.h>
18#include <linux/proc_fs.h>
19#include <linux/seq_file.h>
20#include <linux/device.h>
21#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
22#include <linux/serial_core.h>
23#include <linux/delay.h>
24#include <linux/mutex.h>
25#include <linux/security.h>
26
27#include <linux/irq.h>
28#include <linux/uaccess.h>
29
30/*
31 * This is used to lock changes in serial line configuration.
32 */
33static DEFINE_MUTEX(port_mutex);
34
35/*
36 * lockdep: port->lock is initialized in two places, but we
37 * want only one lock-class:
38 */
39static struct lock_class_key port_lock_key;
40
41#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
42
43static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
44 struct ktermios *old_termios);
45static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
46static void uart_change_pm(struct uart_state *state,
47 enum uart_pm_state pm_state);
48
49static void uart_port_shutdown(struct tty_port *port);
50
51static int uart_dcd_enabled(struct uart_port *uport)
52{
53 return !!(uport->status & UPSTAT_DCD_ENABLE);
54}
55
56static inline struct uart_port *uart_port_ref(struct uart_state *state)
57{
58 if (atomic_add_unless(&state->refcount, 1, 0))
59 return state->uart_port;
60 return NULL;
61}
62
63static inline void uart_port_deref(struct uart_port *uport)
64{
65 if (atomic_dec_and_test(&uport->state->refcount))
66 wake_up(&uport->state->remove_wait);
67}
68
69#define uart_port_lock(state, flags) \
70 ({ \
71 struct uart_port *__uport = uart_port_ref(state); \
72 if (__uport) \
73 spin_lock_irqsave(&__uport->lock, flags); \
74 __uport; \
75 })
76
77#define uart_port_unlock(uport, flags) \
78 ({ \
79 struct uart_port *__uport = uport; \
80 if (__uport) { \
81 spin_unlock_irqrestore(&__uport->lock, flags); \
82 uart_port_deref(__uport); \
83 } \
84 })
85
86static inline struct uart_port *uart_port_check(struct uart_state *state)
87{
88 lockdep_assert_held(&state->port.mutex);
89 return state->uart_port;
90}
91
92/*
93 * This routine is used by the interrupt handler to schedule processing in
94 * the software interrupt portion of the driver.
95 */
96void uart_write_wakeup(struct uart_port *port)
97{
98 struct uart_state *state = port->state;
99 /*
100 * This means you called this function _after_ the port was
101 * closed. No cookie for you.
102 */
103 BUG_ON(!state);
104 tty_port_tty_wakeup(&state->port);
105}
106
107static void uart_stop(struct tty_struct *tty)
108{
109 struct uart_state *state = tty->driver_data;
110 struct uart_port *port;
111 unsigned long flags;
112
113 port = uart_port_lock(state, flags);
114 if (port)
115 port->ops->stop_tx(port);
116 uart_port_unlock(port, flags);
117}
118
119static void __uart_start(struct tty_struct *tty)
120{
121 struct uart_state *state = tty->driver_data;
122 struct uart_port *port = state->uart_port;
123
124 if (port && !uart_tx_stopped(port))
125 port->ops->start_tx(port);
126}
127
128static void uart_start(struct tty_struct *tty)
129{
130 struct uart_state *state = tty->driver_data;
131 struct uart_port *port;
132 unsigned long flags;
133
134 port = uart_port_lock(state, flags);
135 __uart_start(tty);
136 uart_port_unlock(port, flags);
137}
138
139static void
140uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
141{
142 unsigned long flags;
143 unsigned int old;
144
145 spin_lock_irqsave(&port->lock, flags);
146 old = port->mctrl;
147 port->mctrl = (old & ~clear) | set;
148 if (old != port->mctrl)
149 port->ops->set_mctrl(port, port->mctrl);
150 spin_unlock_irqrestore(&port->lock, flags);
151}
152
153#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
154#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
155
156static void uart_port_dtr_rts(struct uart_port *uport, int raise)
157{
158 int rs485_on = uport->rs485_config &&
159 (uport->rs485.flags & SER_RS485_ENABLED);
160 int RTS_after_send = !!(uport->rs485.flags & SER_RS485_RTS_AFTER_SEND);
161
162 if (raise) {
163 if (rs485_on && !RTS_after_send) {
164 uart_set_mctrl(uport, TIOCM_DTR);
165 uart_clear_mctrl(uport, TIOCM_RTS);
166 } else {
167 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
168 }
169 } else {
170 unsigned int clear = TIOCM_DTR;
171
172 clear |= (!rs485_on || !RTS_after_send) ? TIOCM_RTS : 0;
173 uart_clear_mctrl(uport, clear);
174 }
175}
176
177/*
178 * Startup the port. This will be called once per open. All calls
179 * will be serialised by the per-port mutex.
180 */
181static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
182 int init_hw)
183{
184 struct uart_port *uport = uart_port_check(state);
185 unsigned long page;
186 unsigned long flags = 0;
187 int retval = 0;
188
189 if (uport->type == PORT_UNKNOWN)
190 return 1;
191
192 /*
193 * Make sure the device is in D0 state.
194 */
195 uart_change_pm(state, UART_PM_STATE_ON);
196
197 /*
198 * Initialise and allocate the transmit and temporary
199 * buffer.
200 */
201 page = get_zeroed_page(GFP_KERNEL);
202 if (!page)
203 return -ENOMEM;
204
205 uart_port_lock(state, flags);
206 if (!state->xmit.buf) {
207 state->xmit.buf = (unsigned char *) page;
208 uart_circ_clear(&state->xmit);
209 uart_port_unlock(uport, flags);
210 } else {
211 uart_port_unlock(uport, flags);
212 /*
213 * Do not free() the page under the port lock, see
214 * uart_shutdown().
215 */
216 free_page(page);
217 }
218
219 retval = uport->ops->startup(uport);
220 if (retval == 0) {
221 if (uart_console(uport) && uport->cons->cflag) {
222 tty->termios.c_cflag = uport->cons->cflag;
223 uport->cons->cflag = 0;
224 }
225 /*
226 * Initialise the hardware port settings.
227 */
228 uart_change_speed(tty, state, NULL);
229
230 /*
231 * Setup the RTS and DTR signals once the
232 * port is open and ready to respond.
233 */
234 if (init_hw && C_BAUD(tty))
235 uart_port_dtr_rts(uport, 1);
236 }
237
238 /*
239 * This is to allow setserial on this port. People may want to set
240 * port/irq/type and then reconfigure the port properly if it failed
241 * now.
242 */
243 if (retval && capable(CAP_SYS_ADMIN))
244 return 1;
245
246 return retval;
247}
248
249static int uart_startup(struct tty_struct *tty, struct uart_state *state,
250 int init_hw)
251{
252 struct tty_port *port = &state->port;
253 int retval;
254
255 if (tty_port_initialized(port))
256 return 0;
257
258 retval = uart_port_startup(tty, state, init_hw);
259 if (retval)
260 set_bit(TTY_IO_ERROR, &tty->flags);
261
262 return retval;
263}
264
265/*
266 * This routine will shutdown a serial port; interrupts are disabled, and
267 * DTR is dropped if the hangup on close termio flag is on. Calls to
268 * uart_shutdown are serialised by the per-port semaphore.
269 *
270 * uport == NULL if uart_port has already been removed
271 */
272static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
273{
274 struct uart_port *uport = uart_port_check(state);
275 struct tty_port *port = &state->port;
276 unsigned long flags = 0;
277 char *xmit_buf = NULL;
278
279 /*
280 * Set the TTY IO error marker
281 */
282 if (tty)
283 set_bit(TTY_IO_ERROR, &tty->flags);
284
285 if (tty_port_initialized(port)) {
286 tty_port_set_initialized(port, 0);
287
288 /*
289 * Turn off DTR and RTS early.
290 */
291 if (uport && uart_console(uport) && tty)
292 uport->cons->cflag = tty->termios.c_cflag;
293
294 if (!tty || C_HUPCL(tty))
295 uart_port_dtr_rts(uport, 0);
296
297 uart_port_shutdown(port);
298 }
299
300 /*
301 * It's possible for shutdown to be called after suspend if we get
302 * a DCD drop (hangup) at just the right time. Clear suspended bit so
303 * we don't try to resume a port that has been shutdown.
304 */
305 tty_port_set_suspended(port, 0);
306
307 /*
308 * Do not free() the transmit buffer page under the port lock since
309 * this can create various circular locking scenarios. For instance,
310 * console driver may need to allocate/free a debug object, which
311 * can endup in printk() recursion.
312 */
313 uart_port_lock(state, flags);
314 xmit_buf = state->xmit.buf;
315 state->xmit.buf = NULL;
316 uart_port_unlock(uport, flags);
317
318 if (xmit_buf)
319 free_page((unsigned long)xmit_buf);
320}
321
322/**
323 * uart_update_timeout - update per-port FIFO timeout.
324 * @port: uart_port structure describing the port
325 * @cflag: termios cflag value
326 * @baud: speed of the port
327 *
328 * Set the port FIFO timeout value. The @cflag value should
329 * reflect the actual hardware settings.
330 */
331void
332uart_update_timeout(struct uart_port *port, unsigned int cflag,
333 unsigned int baud)
334{
335 unsigned int bits;
336
337 /* byte size and parity */
338 switch (cflag & CSIZE) {
339 case CS5:
340 bits = 7;
341 break;
342 case CS6:
343 bits = 8;
344 break;
345 case CS7:
346 bits = 9;
347 break;
348 default:
349 bits = 10;
350 break; /* CS8 */
351 }
352
353 if (cflag & CSTOPB)
354 bits++;
355 if (cflag & PARENB)
356 bits++;
357
358 /*
359 * The total number of bits to be transmitted in the fifo.
360 */
361 bits = bits * port->fifosize;
362
363 /*
364 * Figure the timeout to send the above number of bits.
365 * Add .02 seconds of slop
366 */
367 port->timeout = (HZ * bits) / baud + HZ/50;
368}
369
370EXPORT_SYMBOL(uart_update_timeout);
371
372/**
373 * uart_get_baud_rate - return baud rate for a particular port
374 * @port: uart_port structure describing the port in question.
375 * @termios: desired termios settings.
376 * @old: old termios (or NULL)
377 * @min: minimum acceptable baud rate
378 * @max: maximum acceptable baud rate
379 *
380 * Decode the termios structure into a numeric baud rate,
381 * taking account of the magic 38400 baud rate (with spd_*
382 * flags), and mapping the %B0 rate to 9600 baud.
383 *
384 * If the new baud rate is invalid, try the old termios setting.
385 * If it's still invalid, we try 9600 baud.
386 *
387 * Update the @termios structure to reflect the baud rate
388 * we're actually going to be using. Don't do this for the case
389 * where B0 is requested ("hang up").
390 */
391unsigned int
392uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
393 struct ktermios *old, unsigned int min, unsigned int max)
394{
395 unsigned int try;
396 unsigned int baud;
397 unsigned int altbaud;
398 int hung_up = 0;
399 upf_t flags = port->flags & UPF_SPD_MASK;
400
401 switch (flags) {
402 case UPF_SPD_HI:
403 altbaud = 57600;
404 break;
405 case UPF_SPD_VHI:
406 altbaud = 115200;
407 break;
408 case UPF_SPD_SHI:
409 altbaud = 230400;
410 break;
411 case UPF_SPD_WARP:
412 altbaud = 460800;
413 break;
414 default:
415 altbaud = 38400;
416 break;
417 }
418
419 for (try = 0; try < 2; try++) {
420 baud = tty_termios_baud_rate(termios);
421
422 /*
423 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
424 * Die! Die! Die!
425 */
426 if (try == 0 && baud == 38400)
427 baud = altbaud;
428
429 /*
430 * Special case: B0 rate.
431 */
432 if (baud == 0) {
433 hung_up = 1;
434 baud = 9600;
435 }
436
437 if (baud >= min && baud <= max)
438 return baud;
439
440 /*
441 * Oops, the quotient was zero. Try again with
442 * the old baud rate if possible.
443 */
444 termios->c_cflag &= ~CBAUD;
445 if (old) {
446 baud = tty_termios_baud_rate(old);
447 if (!hung_up)
448 tty_termios_encode_baud_rate(termios,
449 baud, baud);
450 old = NULL;
451 continue;
452 }
453
454 /*
455 * As a last resort, if the range cannot be met then clip to
456 * the nearest chip supported rate.
457 */
458 if (!hung_up) {
459 if (baud <= min)
460 tty_termios_encode_baud_rate(termios,
461 min + 1, min + 1);
462 else
463 tty_termios_encode_baud_rate(termios,
464 max - 1, max - 1);
465 }
466 }
467 /* Should never happen */
468 WARN_ON(1);
469 return 0;
470}
471
472EXPORT_SYMBOL(uart_get_baud_rate);
473
474/**
475 * uart_get_divisor - return uart clock divisor
476 * @port: uart_port structure describing the port.
477 * @baud: desired baud rate
478 *
479 * Calculate the uart clock divisor for the port.
480 */
481unsigned int
482uart_get_divisor(struct uart_port *port, unsigned int baud)
483{
484 unsigned int quot;
485
486 /*
487 * Old custom speed handling.
488 */
489 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
490 quot = port->custom_divisor;
491 else
492 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
493
494 return quot;
495}
496
497EXPORT_SYMBOL(uart_get_divisor);
498
499/* Caller holds port mutex */
500static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
501 struct ktermios *old_termios)
502{
503 struct uart_port *uport = uart_port_check(state);
504 struct ktermios *termios;
505 int hw_stopped;
506
507 /*
508 * If we have no tty, termios, or the port does not exist,
509 * then we can't set the parameters for this port.
510 */
511 if (!tty || uport->type == PORT_UNKNOWN)
512 return;
513
514 termios = &tty->termios;
515 uport->ops->set_termios(uport, termios, old_termios);
516
517 /*
518 * Set modem status enables based on termios cflag
519 */
520 spin_lock_irq(&uport->lock);
521 if (termios->c_cflag & CRTSCTS)
522 uport->status |= UPSTAT_CTS_ENABLE;
523 else
524 uport->status &= ~UPSTAT_CTS_ENABLE;
525
526 if (termios->c_cflag & CLOCAL)
527 uport->status &= ~UPSTAT_DCD_ENABLE;
528 else
529 uport->status |= UPSTAT_DCD_ENABLE;
530
531 /* reset sw-assisted CTS flow control based on (possibly) new mode */
532 hw_stopped = uport->hw_stopped;
533 uport->hw_stopped = uart_softcts_mode(uport) &&
534 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
535 if (uport->hw_stopped) {
536 if (!hw_stopped)
537 uport->ops->stop_tx(uport);
538 } else {
539 if (hw_stopped)
540 __uart_start(tty);
541 }
542 spin_unlock_irq(&uport->lock);
543}
544
545static int uart_put_char(struct tty_struct *tty, unsigned char c)
546{
547 struct uart_state *state = tty->driver_data;
548 struct uart_port *port;
549 struct circ_buf *circ;
550 unsigned long flags;
551 int ret = 0;
552
553 circ = &state->xmit;
554 port = uart_port_lock(state, flags);
555 if (!circ->buf) {
556 uart_port_unlock(port, flags);
557 return 0;
558 }
559
560 if (port && uart_circ_chars_free(circ) != 0) {
561 circ->buf[circ->head] = c;
562 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
563 ret = 1;
564 }
565 uart_port_unlock(port, flags);
566 return ret;
567}
568
569static void uart_flush_chars(struct tty_struct *tty)
570{
571 uart_start(tty);
572}
573
574static int uart_write(struct tty_struct *tty,
575 const unsigned char *buf, int count)
576{
577 struct uart_state *state = tty->driver_data;
578 struct uart_port *port;
579 struct circ_buf *circ;
580 unsigned long flags;
581 int c, ret = 0;
582
583 /*
584 * This means you called this function _after_ the port was
585 * closed. No cookie for you.
586 */
587 if (!state) {
588 WARN_ON(1);
589 return -EL3HLT;
590 }
591
592 port = uart_port_lock(state, flags);
593 circ = &state->xmit;
594 if (!circ->buf) {
595 uart_port_unlock(port, flags);
596 return 0;
597 }
598
599 while (port) {
600 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
601 if (count < c)
602 c = count;
603 if (c <= 0)
604 break;
605 memcpy(circ->buf + circ->head, buf, c);
606 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
607 buf += c;
608 count -= c;
609 ret += c;
610 }
611
612 __uart_start(tty);
613 uart_port_unlock(port, flags);
614 return ret;
615}
616
617static int uart_write_room(struct tty_struct *tty)
618{
619 struct uart_state *state = tty->driver_data;
620 struct uart_port *port;
621 unsigned long flags;
622 int ret;
623
624 port = uart_port_lock(state, flags);
625 ret = uart_circ_chars_free(&state->xmit);
626 uart_port_unlock(port, flags);
627 return ret;
628}
629
630static int uart_chars_in_buffer(struct tty_struct *tty)
631{
632 struct uart_state *state = tty->driver_data;
633 struct uart_port *port;
634 unsigned long flags;
635 int ret;
636
637 port = uart_port_lock(state, flags);
638 ret = uart_circ_chars_pending(&state->xmit);
639 uart_port_unlock(port, flags);
640 return ret;
641}
642
643static void uart_flush_buffer(struct tty_struct *tty)
644{
645 struct uart_state *state = tty->driver_data;
646 struct uart_port *port;
647 unsigned long flags;
648
649 /*
650 * This means you called this function _after_ the port was
651 * closed. No cookie for you.
652 */
653 if (!state) {
654 WARN_ON(1);
655 return;
656 }
657
658 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
659
660 port = uart_port_lock(state, flags);
661 if (!port)
662 return;
663 uart_circ_clear(&state->xmit);
664 if (port->ops->flush_buffer)
665 port->ops->flush_buffer(port);
666 uart_port_unlock(port, flags);
667 tty_port_tty_wakeup(&state->port);
668}
669
670/*
671 * This function is used to send a high-priority XON/XOFF character to
672 * the device
673 */
674static void uart_send_xchar(struct tty_struct *tty, char ch)
675{
676 struct uart_state *state = tty->driver_data;
677 struct uart_port *port;
678 unsigned long flags;
679
680 port = uart_port_ref(state);
681 if (!port)
682 return;
683
684 if (port->ops->send_xchar)
685 port->ops->send_xchar(port, ch);
686 else {
687 spin_lock_irqsave(&port->lock, flags);
688 port->x_char = ch;
689 if (ch)
690 port->ops->start_tx(port);
691 spin_unlock_irqrestore(&port->lock, flags);
692 }
693 uart_port_deref(port);
694}
695
696static void uart_throttle(struct tty_struct *tty)
697{
698 struct uart_state *state = tty->driver_data;
699 upstat_t mask = UPSTAT_SYNC_FIFO;
700 struct uart_port *port;
701
702 port = uart_port_ref(state);
703 if (!port)
704 return;
705
706 if (I_IXOFF(tty))
707 mask |= UPSTAT_AUTOXOFF;
708 if (C_CRTSCTS(tty))
709 mask |= UPSTAT_AUTORTS;
710
711 if (port->status & mask) {
712 port->ops->throttle(port);
713 mask &= ~port->status;
714 }
715
716 if (mask & UPSTAT_AUTORTS)
717 uart_clear_mctrl(port, TIOCM_RTS);
718
719 if (mask & UPSTAT_AUTOXOFF)
720 uart_send_xchar(tty, STOP_CHAR(tty));
721
722 uart_port_deref(port);
723}
724
725static void uart_unthrottle(struct tty_struct *tty)
726{
727 struct uart_state *state = tty->driver_data;
728 upstat_t mask = UPSTAT_SYNC_FIFO;
729 struct uart_port *port;
730
731 port = uart_port_ref(state);
732 if (!port)
733 return;
734
735 if (I_IXOFF(tty))
736 mask |= UPSTAT_AUTOXOFF;
737 if (C_CRTSCTS(tty))
738 mask |= UPSTAT_AUTORTS;
739
740 if (port->status & mask) {
741 port->ops->unthrottle(port);
742 mask &= ~port->status;
743 }
744
745 if (mask & UPSTAT_AUTORTS)
746 uart_set_mctrl(port, TIOCM_RTS);
747
748 if (mask & UPSTAT_AUTOXOFF)
749 uart_send_xchar(tty, START_CHAR(tty));
750
751 uart_port_deref(port);
752}
753
754static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
755{
756 struct uart_state *state = container_of(port, struct uart_state, port);
757 struct uart_port *uport;
758 int ret = -ENODEV;
759
760 memset(retinfo, 0, sizeof(*retinfo));
761
762 /*
763 * Ensure the state we copy is consistent and no hardware changes
764 * occur as we go
765 */
766 mutex_lock(&port->mutex);
767 uport = uart_port_check(state);
768 if (!uport)
769 goto out;
770
771 retinfo->type = uport->type;
772 retinfo->line = uport->line;
773 retinfo->port = uport->iobase;
774 if (HIGH_BITS_OFFSET)
775 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
776 retinfo->irq = uport->irq;
777 retinfo->flags = (__force int)uport->flags;
778 retinfo->xmit_fifo_size = uport->fifosize;
779 retinfo->baud_base = uport->uartclk / 16;
780 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
781 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
782 ASYNC_CLOSING_WAIT_NONE :
783 jiffies_to_msecs(port->closing_wait) / 10;
784 retinfo->custom_divisor = uport->custom_divisor;
785 retinfo->hub6 = uport->hub6;
786 retinfo->io_type = uport->iotype;
787 retinfo->iomem_reg_shift = uport->regshift;
788 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
789
790 ret = 0;
791out:
792 mutex_unlock(&port->mutex);
793 return ret;
794}
795
796static int uart_get_info_user(struct tty_struct *tty,
797 struct serial_struct *ss)
798{
799 struct uart_state *state = tty->driver_data;
800 struct tty_port *port = &state->port;
801
802 return uart_get_info(port, ss) < 0 ? -EIO : 0;
803}
804
805static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
806 struct uart_state *state,
807 struct serial_struct *new_info)
808{
809 struct uart_port *uport = uart_port_check(state);
810 unsigned long new_port;
811 unsigned int change_irq, change_port, closing_wait;
812 unsigned int old_custom_divisor, close_delay;
813 upf_t old_flags, new_flags;
814 int retval = 0;
815
816 if (!uport)
817 return -EIO;
818
819 new_port = new_info->port;
820 if (HIGH_BITS_OFFSET)
821 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
822
823 new_info->irq = irq_canonicalize(new_info->irq);
824 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
825 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
826 ASYNC_CLOSING_WAIT_NONE :
827 msecs_to_jiffies(new_info->closing_wait * 10);
828
829
830 change_irq = !(uport->flags & UPF_FIXED_PORT)
831 && new_info->irq != uport->irq;
832
833 /*
834 * Since changing the 'type' of the port changes its resource
835 * allocations, we should treat type changes the same as
836 * IO port changes.
837 */
838 change_port = !(uport->flags & UPF_FIXED_PORT)
839 && (new_port != uport->iobase ||
840 (unsigned long)new_info->iomem_base != uport->mapbase ||
841 new_info->hub6 != uport->hub6 ||
842 new_info->io_type != uport->iotype ||
843 new_info->iomem_reg_shift != uport->regshift ||
844 new_info->type != uport->type);
845
846 old_flags = uport->flags;
847 new_flags = (__force upf_t)new_info->flags;
848 old_custom_divisor = uport->custom_divisor;
849
850 if (!capable(CAP_SYS_ADMIN)) {
851 retval = -EPERM;
852 if (change_irq || change_port ||
853 (new_info->baud_base != uport->uartclk / 16) ||
854 (close_delay != port->close_delay) ||
855 (closing_wait != port->closing_wait) ||
856 (new_info->xmit_fifo_size &&
857 new_info->xmit_fifo_size != uport->fifosize) ||
858 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
859 goto exit;
860 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
861 (new_flags & UPF_USR_MASK));
862 uport->custom_divisor = new_info->custom_divisor;
863 goto check_and_exit;
864 }
865
866 retval = security_locked_down(LOCKDOWN_TIOCSSERIAL);
867 if (retval && (change_irq || change_port))
868 goto exit;
869
870 /*
871 * Ask the low level driver to verify the settings.
872 */
873 if (uport->ops->verify_port)
874 retval = uport->ops->verify_port(uport, new_info);
875
876 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
877 (new_info->baud_base < 9600))
878 retval = -EINVAL;
879
880 if (retval)
881 goto exit;
882
883 if (change_port || change_irq) {
884 retval = -EBUSY;
885
886 /*
887 * Make sure that we are the sole user of this port.
888 */
889 if (tty_port_users(port) > 1)
890 goto exit;
891
892 /*
893 * We need to shutdown the serial port at the old
894 * port/type/irq combination.
895 */
896 uart_shutdown(tty, state);
897 }
898
899 if (change_port) {
900 unsigned long old_iobase, old_mapbase;
901 unsigned int old_type, old_iotype, old_hub6, old_shift;
902
903 old_iobase = uport->iobase;
904 old_mapbase = uport->mapbase;
905 old_type = uport->type;
906 old_hub6 = uport->hub6;
907 old_iotype = uport->iotype;
908 old_shift = uport->regshift;
909
910 /*
911 * Free and release old regions
912 */
913 if (old_type != PORT_UNKNOWN && uport->ops->release_port)
914 uport->ops->release_port(uport);
915
916 uport->iobase = new_port;
917 uport->type = new_info->type;
918 uport->hub6 = new_info->hub6;
919 uport->iotype = new_info->io_type;
920 uport->regshift = new_info->iomem_reg_shift;
921 uport->mapbase = (unsigned long)new_info->iomem_base;
922
923 /*
924 * Claim and map the new regions
925 */
926 if (uport->type != PORT_UNKNOWN && uport->ops->request_port) {
927 retval = uport->ops->request_port(uport);
928 } else {
929 /* Always success - Jean II */
930 retval = 0;
931 }
932
933 /*
934 * If we fail to request resources for the
935 * new port, try to restore the old settings.
936 */
937 if (retval) {
938 uport->iobase = old_iobase;
939 uport->type = old_type;
940 uport->hub6 = old_hub6;
941 uport->iotype = old_iotype;
942 uport->regshift = old_shift;
943 uport->mapbase = old_mapbase;
944
945 if (old_type != PORT_UNKNOWN) {
946 retval = uport->ops->request_port(uport);
947 /*
948 * If we failed to restore the old settings,
949 * we fail like this.
950 */
951 if (retval)
952 uport->type = PORT_UNKNOWN;
953
954 /*
955 * We failed anyway.
956 */
957 retval = -EBUSY;
958 }
959
960 /* Added to return the correct error -Ram Gupta */
961 goto exit;
962 }
963 }
964
965 if (change_irq)
966 uport->irq = new_info->irq;
967 if (!(uport->flags & UPF_FIXED_PORT))
968 uport->uartclk = new_info->baud_base * 16;
969 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
970 (new_flags & UPF_CHANGE_MASK);
971 uport->custom_divisor = new_info->custom_divisor;
972 port->close_delay = close_delay;
973 port->closing_wait = closing_wait;
974 if (new_info->xmit_fifo_size)
975 uport->fifosize = new_info->xmit_fifo_size;
976 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
977
978 check_and_exit:
979 retval = 0;
980 if (uport->type == PORT_UNKNOWN)
981 goto exit;
982 if (tty_port_initialized(port)) {
983 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
984 old_custom_divisor != uport->custom_divisor) {
985 /*
986 * If they're setting up a custom divisor or speed,
987 * instead of clearing it, then bitch about it.
988 */
989 if (uport->flags & UPF_SPD_MASK) {
990 dev_notice_ratelimited(uport->dev,
991 "%s sets custom speed on %s. This is deprecated.\n",
992 current->comm,
993 tty_name(port->tty));
994 }
995 uart_change_speed(tty, state, NULL);
996 }
997 } else {
998 retval = uart_startup(tty, state, 1);
999 if (retval == 0)
1000 tty_port_set_initialized(port, true);
1001 if (retval > 0)
1002 retval = 0;
1003 }
1004 exit:
1005 return retval;
1006}
1007
1008static int uart_set_info_user(struct tty_struct *tty, struct serial_struct *ss)
1009{
1010 struct uart_state *state = tty->driver_data;
1011 struct tty_port *port = &state->port;
1012 int retval;
1013
1014 down_write(&tty->termios_rwsem);
1015 /*
1016 * This semaphore protects port->count. It is also
1017 * very useful to prevent opens. Also, take the
1018 * port configuration semaphore to make sure that a
1019 * module insertion/removal doesn't change anything
1020 * under us.
1021 */
1022 mutex_lock(&port->mutex);
1023 retval = uart_set_info(tty, port, state, ss);
1024 mutex_unlock(&port->mutex);
1025 up_write(&tty->termios_rwsem);
1026 return retval;
1027}
1028
1029/**
1030 * uart_get_lsr_info - get line status register info
1031 * @tty: tty associated with the UART
1032 * @state: UART being queried
1033 * @value: returned modem value
1034 */
1035static int uart_get_lsr_info(struct tty_struct *tty,
1036 struct uart_state *state, unsigned int __user *value)
1037{
1038 struct uart_port *uport = uart_port_check(state);
1039 unsigned int result;
1040
1041 result = uport->ops->tx_empty(uport);
1042
1043 /*
1044 * If we're about to load something into the transmit
1045 * register, we'll pretend the transmitter isn't empty to
1046 * avoid a race condition (depending on when the transmit
1047 * interrupt happens).
1048 */
1049 if (uport->x_char ||
1050 ((uart_circ_chars_pending(&state->xmit) > 0) &&
1051 !uart_tx_stopped(uport)))
1052 result &= ~TIOCSER_TEMT;
1053
1054 return put_user(result, value);
1055}
1056
1057static int uart_tiocmget(struct tty_struct *tty)
1058{
1059 struct uart_state *state = tty->driver_data;
1060 struct tty_port *port = &state->port;
1061 struct uart_port *uport;
1062 int result = -EIO;
1063
1064 mutex_lock(&port->mutex);
1065 uport = uart_port_check(state);
1066 if (!uport)
1067 goto out;
1068
1069 if (!tty_io_error(tty)) {
1070 result = uport->mctrl;
1071 spin_lock_irq(&uport->lock);
1072 result |= uport->ops->get_mctrl(uport);
1073 spin_unlock_irq(&uport->lock);
1074 }
1075out:
1076 mutex_unlock(&port->mutex);
1077 return result;
1078}
1079
1080static int
1081uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
1082{
1083 struct uart_state *state = tty->driver_data;
1084 struct tty_port *port = &state->port;
1085 struct uart_port *uport;
1086 int ret = -EIO;
1087
1088 mutex_lock(&port->mutex);
1089 uport = uart_port_check(state);
1090 if (!uport)
1091 goto out;
1092
1093 if (!tty_io_error(tty)) {
1094 uart_update_mctrl(uport, set, clear);
1095 ret = 0;
1096 }
1097out:
1098 mutex_unlock(&port->mutex);
1099 return ret;
1100}
1101
1102static int uart_break_ctl(struct tty_struct *tty, int break_state)
1103{
1104 struct uart_state *state = tty->driver_data;
1105 struct tty_port *port = &state->port;
1106 struct uart_port *uport;
1107 int ret = -EIO;
1108
1109 mutex_lock(&port->mutex);
1110 uport = uart_port_check(state);
1111 if (!uport)
1112 goto out;
1113
1114 if (uport->type != PORT_UNKNOWN)
1115 uport->ops->break_ctl(uport, break_state);
1116 ret = 0;
1117out:
1118 mutex_unlock(&port->mutex);
1119 return ret;
1120}
1121
1122static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1123{
1124 struct tty_port *port = &state->port;
1125 struct uart_port *uport;
1126 int flags, ret;
1127
1128 if (!capable(CAP_SYS_ADMIN))
1129 return -EPERM;
1130
1131 /*
1132 * Take the per-port semaphore. This prevents count from
1133 * changing, and hence any extra opens of the port while
1134 * we're auto-configuring.
1135 */
1136 if (mutex_lock_interruptible(&port->mutex))
1137 return -ERESTARTSYS;
1138
1139 uport = uart_port_check(state);
1140 if (!uport) {
1141 ret = -EIO;
1142 goto out;
1143 }
1144
1145 ret = -EBUSY;
1146 if (tty_port_users(port) == 1) {
1147 uart_shutdown(tty, state);
1148
1149 /*
1150 * If we already have a port type configured,
1151 * we must release its resources.
1152 */
1153 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
1154 uport->ops->release_port(uport);
1155
1156 flags = UART_CONFIG_TYPE;
1157 if (uport->flags & UPF_AUTO_IRQ)
1158 flags |= UART_CONFIG_IRQ;
1159
1160 /*
1161 * This will claim the ports resources if
1162 * a port is found.
1163 */
1164 uport->ops->config_port(uport, flags);
1165
1166 ret = uart_startup(tty, state, 1);
1167 if (ret == 0)
1168 tty_port_set_initialized(port, true);
1169 if (ret > 0)
1170 ret = 0;
1171 }
1172out:
1173 mutex_unlock(&port->mutex);
1174 return ret;
1175}
1176
1177static void uart_enable_ms(struct uart_port *uport)
1178{
1179 /*
1180 * Force modem status interrupts on
1181 */
1182 if (uport->ops->enable_ms)
1183 uport->ops->enable_ms(uport);
1184}
1185
1186/*
1187 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1188 * - mask passed in arg for lines of interest
1189 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1190 * Caller should use TIOCGICOUNT to see which one it was
1191 *
1192 * FIXME: This wants extracting into a common all driver implementation
1193 * of TIOCMWAIT using tty_port.
1194 */
1195static int uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1196{
1197 struct uart_port *uport;
1198 struct tty_port *port = &state->port;
1199 DECLARE_WAITQUEUE(wait, current);
1200 struct uart_icount cprev, cnow;
1201 int ret;
1202
1203 /*
1204 * note the counters on entry
1205 */
1206 uport = uart_port_ref(state);
1207 if (!uport)
1208 return -EIO;
1209 spin_lock_irq(&uport->lock);
1210 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1211 uart_enable_ms(uport);
1212 spin_unlock_irq(&uport->lock);
1213
1214 add_wait_queue(&port->delta_msr_wait, &wait);
1215 for (;;) {
1216 spin_lock_irq(&uport->lock);
1217 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1218 spin_unlock_irq(&uport->lock);
1219
1220 set_current_state(TASK_INTERRUPTIBLE);
1221
1222 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1223 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1224 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1225 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1226 ret = 0;
1227 break;
1228 }
1229
1230 schedule();
1231
1232 /* see if a signal did it */
1233 if (signal_pending(current)) {
1234 ret = -ERESTARTSYS;
1235 break;
1236 }
1237
1238 cprev = cnow;
1239 }
1240 __set_current_state(TASK_RUNNING);
1241 remove_wait_queue(&port->delta_msr_wait, &wait);
1242 uart_port_deref(uport);
1243
1244 return ret;
1245}
1246
1247/*
1248 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1249 * Return: write counters to the user passed counter struct
1250 * NB: both 1->0 and 0->1 transitions are counted except for
1251 * RI where only 0->1 is counted.
1252 */
1253static int uart_get_icount(struct tty_struct *tty,
1254 struct serial_icounter_struct *icount)
1255{
1256 struct uart_state *state = tty->driver_data;
1257 struct uart_icount cnow;
1258 struct uart_port *uport;
1259
1260 uport = uart_port_ref(state);
1261 if (!uport)
1262 return -EIO;
1263 spin_lock_irq(&uport->lock);
1264 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1265 spin_unlock_irq(&uport->lock);
1266 uart_port_deref(uport);
1267
1268 icount->cts = cnow.cts;
1269 icount->dsr = cnow.dsr;
1270 icount->rng = cnow.rng;
1271 icount->dcd = cnow.dcd;
1272 icount->rx = cnow.rx;
1273 icount->tx = cnow.tx;
1274 icount->frame = cnow.frame;
1275 icount->overrun = cnow.overrun;
1276 icount->parity = cnow.parity;
1277 icount->brk = cnow.brk;
1278 icount->buf_overrun = cnow.buf_overrun;
1279
1280 return 0;
1281}
1282
1283static int uart_get_rs485_config(struct uart_port *port,
1284 struct serial_rs485 __user *rs485)
1285{
1286 unsigned long flags;
1287 struct serial_rs485 aux;
1288
1289 spin_lock_irqsave(&port->lock, flags);
1290 aux = port->rs485;
1291 spin_unlock_irqrestore(&port->lock, flags);
1292
1293 if (copy_to_user(rs485, &aux, sizeof(aux)))
1294 return -EFAULT;
1295
1296 return 0;
1297}
1298
1299static int uart_set_rs485_config(struct uart_port *port,
1300 struct serial_rs485 __user *rs485_user)
1301{
1302 struct serial_rs485 rs485;
1303 int ret;
1304 unsigned long flags;
1305
1306 if (!port->rs485_config)
1307 return -ENOIOCTLCMD;
1308
1309 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1310 return -EFAULT;
1311
1312 spin_lock_irqsave(&port->lock, flags);
1313 ret = port->rs485_config(port, &rs485);
1314 spin_unlock_irqrestore(&port->lock, flags);
1315 if (ret)
1316 return ret;
1317
1318 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1319 return -EFAULT;
1320
1321 return 0;
1322}
1323
1324static int uart_get_iso7816_config(struct uart_port *port,
1325 struct serial_iso7816 __user *iso7816)
1326{
1327 unsigned long flags;
1328 struct serial_iso7816 aux;
1329
1330 if (!port->iso7816_config)
1331 return -ENOIOCTLCMD;
1332
1333 spin_lock_irqsave(&port->lock, flags);
1334 aux = port->iso7816;
1335 spin_unlock_irqrestore(&port->lock, flags);
1336
1337 if (copy_to_user(iso7816, &aux, sizeof(aux)))
1338 return -EFAULT;
1339
1340 return 0;
1341}
1342
1343static int uart_set_iso7816_config(struct uart_port *port,
1344 struct serial_iso7816 __user *iso7816_user)
1345{
1346 struct serial_iso7816 iso7816;
1347 int i, ret;
1348 unsigned long flags;
1349
1350 if (!port->iso7816_config)
1351 return -ENOIOCTLCMD;
1352
1353 if (copy_from_user(&iso7816, iso7816_user, sizeof(*iso7816_user)))
1354 return -EFAULT;
1355
1356 /*
1357 * There are 5 words reserved for future use. Check that userspace
1358 * doesn't put stuff in there to prevent breakages in the future.
1359 */
1360 for (i = 0; i < 5; i++)
1361 if (iso7816.reserved[i])
1362 return -EINVAL;
1363
1364 spin_lock_irqsave(&port->lock, flags);
1365 ret = port->iso7816_config(port, &iso7816);
1366 spin_unlock_irqrestore(&port->lock, flags);
1367 if (ret)
1368 return ret;
1369
1370 if (copy_to_user(iso7816_user, &port->iso7816, sizeof(port->iso7816)))
1371 return -EFAULT;
1372
1373 return 0;
1374}
1375
1376/*
1377 * Called via sys_ioctl. We can use spin_lock_irq() here.
1378 */
1379static int
1380uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
1381{
1382 struct uart_state *state = tty->driver_data;
1383 struct tty_port *port = &state->port;
1384 struct uart_port *uport;
1385 void __user *uarg = (void __user *)arg;
1386 int ret = -ENOIOCTLCMD;
1387
1388
1389 /*
1390 * These ioctls don't rely on the hardware to be present.
1391 */
1392 switch (cmd) {
1393 case TIOCSERCONFIG:
1394 down_write(&tty->termios_rwsem);
1395 ret = uart_do_autoconfig(tty, state);
1396 up_write(&tty->termios_rwsem);
1397 break;
1398 }
1399
1400 if (ret != -ENOIOCTLCMD)
1401 goto out;
1402
1403 if (tty_io_error(tty)) {
1404 ret = -EIO;
1405 goto out;
1406 }
1407
1408 /*
1409 * The following should only be used when hardware is present.
1410 */
1411 switch (cmd) {
1412 case TIOCMIWAIT:
1413 ret = uart_wait_modem_status(state, arg);
1414 break;
1415 }
1416
1417 if (ret != -ENOIOCTLCMD)
1418 goto out;
1419
1420 mutex_lock(&port->mutex);
1421 uport = uart_port_check(state);
1422
1423 if (!uport || tty_io_error(tty)) {
1424 ret = -EIO;
1425 goto out_up;
1426 }
1427
1428 /*
1429 * All these rely on hardware being present and need to be
1430 * protected against the tty being hung up.
1431 */
1432
1433 switch (cmd) {
1434 case TIOCSERGETLSR: /* Get line status register */
1435 ret = uart_get_lsr_info(tty, state, uarg);
1436 break;
1437
1438 case TIOCGRS485:
1439 ret = uart_get_rs485_config(uport, uarg);
1440 break;
1441
1442 case TIOCSRS485:
1443 ret = uart_set_rs485_config(uport, uarg);
1444 break;
1445
1446 case TIOCSISO7816:
1447 ret = uart_set_iso7816_config(state->uart_port, uarg);
1448 break;
1449
1450 case TIOCGISO7816:
1451 ret = uart_get_iso7816_config(state->uart_port, uarg);
1452 break;
1453 default:
1454 if (uport->ops->ioctl)
1455 ret = uport->ops->ioctl(uport, cmd, arg);
1456 break;
1457 }
1458out_up:
1459 mutex_unlock(&port->mutex);
1460out:
1461 return ret;
1462}
1463
1464static void uart_set_ldisc(struct tty_struct *tty)
1465{
1466 struct uart_state *state = tty->driver_data;
1467 struct uart_port *uport;
1468
1469 mutex_lock(&state->port.mutex);
1470 uport = uart_port_check(state);
1471 if (uport && uport->ops->set_ldisc)
1472 uport->ops->set_ldisc(uport, &tty->termios);
1473 mutex_unlock(&state->port.mutex);
1474}
1475
1476static void uart_set_termios(struct tty_struct *tty,
1477 struct ktermios *old_termios)
1478{
1479 struct uart_state *state = tty->driver_data;
1480 struct uart_port *uport;
1481 unsigned int cflag = tty->termios.c_cflag;
1482 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1483 bool sw_changed = false;
1484
1485 mutex_lock(&state->port.mutex);
1486 uport = uart_port_check(state);
1487 if (!uport)
1488 goto out;
1489
1490 /*
1491 * Drivers doing software flow control also need to know
1492 * about changes to these input settings.
1493 */
1494 if (uport->flags & UPF_SOFT_FLOW) {
1495 iflag_mask |= IXANY|IXON|IXOFF;
1496 sw_changed =
1497 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1498 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1499 }
1500
1501 /*
1502 * These are the bits that are used to setup various
1503 * flags in the low level driver. We can ignore the Bfoo
1504 * bits in c_cflag; c_[io]speed will always be set
1505 * appropriately by set_termios() in tty_ioctl.c
1506 */
1507 if ((cflag ^ old_termios->c_cflag) == 0 &&
1508 tty->termios.c_ospeed == old_termios->c_ospeed &&
1509 tty->termios.c_ispeed == old_termios->c_ispeed &&
1510 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1511 !sw_changed) {
1512 goto out;
1513 }
1514
1515 uart_change_speed(tty, state, old_termios);
1516 /* reload cflag from termios; port driver may have overridden flags */
1517 cflag = tty->termios.c_cflag;
1518
1519 /* Handle transition to B0 status */
1520 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1521 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1522 /* Handle transition away from B0 status */
1523 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1524 unsigned int mask = TIOCM_DTR;
1525 if (!(cflag & CRTSCTS) || !tty_throttled(tty))
1526 mask |= TIOCM_RTS;
1527 uart_set_mctrl(uport, mask);
1528 }
1529out:
1530 mutex_unlock(&state->port.mutex);
1531}
1532
1533/*
1534 * Calls to uart_close() are serialised via the tty_lock in
1535 * drivers/tty/tty_io.c:tty_release()
1536 * drivers/tty/tty_io.c:do_tty_hangup()
1537 */
1538static void uart_close(struct tty_struct *tty, struct file *filp)
1539{
1540 struct uart_state *state = tty->driver_data;
1541
1542 if (!state) {
1543 struct uart_driver *drv = tty->driver->driver_state;
1544 struct tty_port *port;
1545
1546 state = drv->state + tty->index;
1547 port = &state->port;
1548 spin_lock_irq(&port->lock);
1549 --port->count;
1550 spin_unlock_irq(&port->lock);
1551 return;
1552 }
1553
1554 pr_debug("uart_close(%d) called\n", tty->index);
1555
1556 tty_port_close(tty->port, tty, filp);
1557}
1558
1559static void uart_tty_port_shutdown(struct tty_port *port)
1560{
1561 struct uart_state *state = container_of(port, struct uart_state, port);
1562 struct uart_port *uport = uart_port_check(state);
1563
1564 /*
1565 * At this point, we stop accepting input. To do this, we
1566 * disable the receive line status interrupts.
1567 */
1568 if (WARN(!uport, "detached port still initialized!\n"))
1569 return;
1570
1571 spin_lock_irq(&uport->lock);
1572 uport->ops->stop_rx(uport);
1573 spin_unlock_irq(&uport->lock);
1574
1575 uart_port_shutdown(port);
1576
1577 /*
1578 * It's possible for shutdown to be called after suspend if we get
1579 * a DCD drop (hangup) at just the right time. Clear suspended bit so
1580 * we don't try to resume a port that has been shutdown.
1581 */
1582 tty_port_set_suspended(port, 0);
1583
1584 uart_change_pm(state, UART_PM_STATE_OFF);
1585
1586}
1587
1588static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1589{
1590 struct uart_state *state = tty->driver_data;
1591 struct uart_port *port;
1592 unsigned long char_time, expire;
1593
1594 port = uart_port_ref(state);
1595 if (!port)
1596 return;
1597
1598 if (port->type == PORT_UNKNOWN || port->fifosize == 0) {
1599 uart_port_deref(port);
1600 return;
1601 }
1602
1603 /*
1604 * Set the check interval to be 1/5 of the estimated time to
1605 * send a single character, and make it at least 1. The check
1606 * interval should also be less than the timeout.
1607 *
1608 * Note: we have to use pretty tight timings here to satisfy
1609 * the NIST-PCTS.
1610 */
1611 char_time = (port->timeout - HZ/50) / port->fifosize;
1612 char_time = char_time / 5;
1613 if (char_time == 0)
1614 char_time = 1;
1615 if (timeout && timeout < char_time)
1616 char_time = timeout;
1617
1618 /*
1619 * If the transmitter hasn't cleared in twice the approximate
1620 * amount of time to send the entire FIFO, it probably won't
1621 * ever clear. This assumes the UART isn't doing flow
1622 * control, which is currently the case. Hence, if it ever
1623 * takes longer than port->timeout, this is probably due to a
1624 * UART bug of some kind. So, we clamp the timeout parameter at
1625 * 2*port->timeout.
1626 */
1627 if (timeout == 0 || timeout > 2 * port->timeout)
1628 timeout = 2 * port->timeout;
1629
1630 expire = jiffies + timeout;
1631
1632 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1633 port->line, jiffies, expire);
1634
1635 /*
1636 * Check whether the transmitter is empty every 'char_time'.
1637 * 'timeout' / 'expire' give us the maximum amount of time
1638 * we wait.
1639 */
1640 while (!port->ops->tx_empty(port)) {
1641 msleep_interruptible(jiffies_to_msecs(char_time));
1642 if (signal_pending(current))
1643 break;
1644 if (time_after(jiffies, expire))
1645 break;
1646 }
1647 uart_port_deref(port);
1648}
1649
1650/*
1651 * Calls to uart_hangup() are serialised by the tty_lock in
1652 * drivers/tty/tty_io.c:do_tty_hangup()
1653 * This runs from a workqueue and can sleep for a _short_ time only.
1654 */
1655static void uart_hangup(struct tty_struct *tty)
1656{
1657 struct uart_state *state = tty->driver_data;
1658 struct tty_port *port = &state->port;
1659 struct uart_port *uport;
1660 unsigned long flags;
1661
1662 pr_debug("uart_hangup(%d)\n", tty->index);
1663
1664 mutex_lock(&port->mutex);
1665 uport = uart_port_check(state);
1666 WARN(!uport, "hangup of detached port!\n");
1667
1668 if (tty_port_active(port)) {
1669 uart_flush_buffer(tty);
1670 uart_shutdown(tty, state);
1671 spin_lock_irqsave(&port->lock, flags);
1672 port->count = 0;
1673 spin_unlock_irqrestore(&port->lock, flags);
1674 tty_port_set_active(port, 0);
1675 tty_port_tty_set(port, NULL);
1676 if (uport && !uart_console(uport))
1677 uart_change_pm(state, UART_PM_STATE_OFF);
1678 wake_up_interruptible(&port->open_wait);
1679 wake_up_interruptible(&port->delta_msr_wait);
1680 }
1681 mutex_unlock(&port->mutex);
1682}
1683
1684/* uport == NULL if uart_port has already been removed */
1685static void uart_port_shutdown(struct tty_port *port)
1686{
1687 struct uart_state *state = container_of(port, struct uart_state, port);
1688 struct uart_port *uport = uart_port_check(state);
1689
1690 /*
1691 * clear delta_msr_wait queue to avoid mem leaks: we may free
1692 * the irq here so the queue might never be woken up. Note
1693 * that we won't end up waiting on delta_msr_wait again since
1694 * any outstanding file descriptors should be pointing at
1695 * hung_up_tty_fops now.
1696 */
1697 wake_up_interruptible(&port->delta_msr_wait);
1698
1699 /*
1700 * Free the IRQ and disable the port.
1701 */
1702 if (uport)
1703 uport->ops->shutdown(uport);
1704
1705 /*
1706 * Ensure that the IRQ handler isn't running on another CPU.
1707 */
1708 if (uport)
1709 synchronize_irq(uport->irq);
1710}
1711
1712static int uart_carrier_raised(struct tty_port *port)
1713{
1714 struct uart_state *state = container_of(port, struct uart_state, port);
1715 struct uart_port *uport;
1716 int mctrl;
1717
1718 uport = uart_port_ref(state);
1719 /*
1720 * Should never observe uport == NULL since checks for hangup should
1721 * abort the tty_port_block_til_ready() loop before checking for carrier
1722 * raised -- but report carrier raised if it does anyway so open will
1723 * continue and not sleep
1724 */
1725 if (WARN_ON(!uport))
1726 return 1;
1727 spin_lock_irq(&uport->lock);
1728 uart_enable_ms(uport);
1729 mctrl = uport->ops->get_mctrl(uport);
1730 spin_unlock_irq(&uport->lock);
1731 uart_port_deref(uport);
1732 if (mctrl & TIOCM_CAR)
1733 return 1;
1734 return 0;
1735}
1736
1737static void uart_dtr_rts(struct tty_port *port, int raise)
1738{
1739 struct uart_state *state = container_of(port, struct uart_state, port);
1740 struct uart_port *uport;
1741
1742 uport = uart_port_ref(state);
1743 if (!uport)
1744 return;
1745 uart_port_dtr_rts(uport, raise);
1746 uart_port_deref(uport);
1747}
1748
1749static int uart_install(struct tty_driver *driver, struct tty_struct *tty)
1750{
1751 struct uart_driver *drv = driver->driver_state;
1752 struct uart_state *state = drv->state + tty->index;
1753
1754 tty->driver_data = state;
1755
1756 return tty_standard_install(driver, tty);
1757}
1758
1759/*
1760 * Calls to uart_open are serialised by the tty_lock in
1761 * drivers/tty/tty_io.c:tty_open()
1762 * Note that if this fails, then uart_close() _will_ be called.
1763 *
1764 * In time, we want to scrap the "opening nonpresent ports"
1765 * behaviour and implement an alternative way for setserial
1766 * to set base addresses/ports/types. This will allow us to
1767 * get rid of a certain amount of extra tests.
1768 */
1769static int uart_open(struct tty_struct *tty, struct file *filp)
1770{
1771 struct uart_state *state = tty->driver_data;
1772 int retval;
1773
1774 retval = tty_port_open(&state->port, tty, filp);
1775 if (retval > 0)
1776 retval = 0;
1777
1778 return retval;
1779}
1780
1781static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1782{
1783 struct uart_state *state = container_of(port, struct uart_state, port);
1784 struct uart_port *uport;
1785 int ret;
1786
1787 uport = uart_port_check(state);
1788 if (!uport || uport->flags & UPF_DEAD)
1789 return -ENXIO;
1790
1791 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
1792
1793 /*
1794 * Start up the serial port.
1795 */
1796 ret = uart_startup(tty, state, 0);
1797 if (ret > 0)
1798 tty_port_set_active(port, 1);
1799
1800 return ret;
1801}
1802
1803static const char *uart_type(struct uart_port *port)
1804{
1805 const char *str = NULL;
1806
1807 if (port->ops->type)
1808 str = port->ops->type(port);
1809
1810 if (!str)
1811 str = "unknown";
1812
1813 return str;
1814}
1815
1816#ifdef CONFIG_PROC_FS
1817
1818static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1819{
1820 struct uart_state *state = drv->state + i;
1821 struct tty_port *port = &state->port;
1822 enum uart_pm_state pm_state;
1823 struct uart_port *uport;
1824 char stat_buf[32];
1825 unsigned int status;
1826 int mmio;
1827
1828 mutex_lock(&port->mutex);
1829 uport = uart_port_check(state);
1830 if (!uport)
1831 goto out;
1832
1833 mmio = uport->iotype >= UPIO_MEM;
1834 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1835 uport->line, uart_type(uport),
1836 mmio ? "mmio:0x" : "port:",
1837 mmio ? (unsigned long long)uport->mapbase
1838 : (unsigned long long)uport->iobase,
1839 uport->irq);
1840
1841 if (uport->type == PORT_UNKNOWN) {
1842 seq_putc(m, '\n');
1843 goto out;
1844 }
1845
1846 if (capable(CAP_SYS_ADMIN)) {
1847 pm_state = state->pm_state;
1848 if (pm_state != UART_PM_STATE_ON)
1849 uart_change_pm(state, UART_PM_STATE_ON);
1850 spin_lock_irq(&uport->lock);
1851 status = uport->ops->get_mctrl(uport);
1852 spin_unlock_irq(&uport->lock);
1853 if (pm_state != UART_PM_STATE_ON)
1854 uart_change_pm(state, pm_state);
1855
1856 seq_printf(m, " tx:%d rx:%d",
1857 uport->icount.tx, uport->icount.rx);
1858 if (uport->icount.frame)
1859 seq_printf(m, " fe:%d", uport->icount.frame);
1860 if (uport->icount.parity)
1861 seq_printf(m, " pe:%d", uport->icount.parity);
1862 if (uport->icount.brk)
1863 seq_printf(m, " brk:%d", uport->icount.brk);
1864 if (uport->icount.overrun)
1865 seq_printf(m, " oe:%d", uport->icount.overrun);
1866 if (uport->icount.buf_overrun)
1867 seq_printf(m, " bo:%d", uport->icount.buf_overrun);
1868
1869#define INFOBIT(bit, str) \
1870 if (uport->mctrl & (bit)) \
1871 strncat(stat_buf, (str), sizeof(stat_buf) - \
1872 strlen(stat_buf) - 2)
1873#define STATBIT(bit, str) \
1874 if (status & (bit)) \
1875 strncat(stat_buf, (str), sizeof(stat_buf) - \
1876 strlen(stat_buf) - 2)
1877
1878 stat_buf[0] = '\0';
1879 stat_buf[1] = '\0';
1880 INFOBIT(TIOCM_RTS, "|RTS");
1881 STATBIT(TIOCM_CTS, "|CTS");
1882 INFOBIT(TIOCM_DTR, "|DTR");
1883 STATBIT(TIOCM_DSR, "|DSR");
1884 STATBIT(TIOCM_CAR, "|CD");
1885 STATBIT(TIOCM_RNG, "|RI");
1886 if (stat_buf[0])
1887 stat_buf[0] = ' ';
1888
1889 seq_puts(m, stat_buf);
1890 }
1891 seq_putc(m, '\n');
1892#undef STATBIT
1893#undef INFOBIT
1894out:
1895 mutex_unlock(&port->mutex);
1896}
1897
1898static int uart_proc_show(struct seq_file *m, void *v)
1899{
1900 struct tty_driver *ttydrv = m->private;
1901 struct uart_driver *drv = ttydrv->driver_state;
1902 int i;
1903
1904 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
1905 for (i = 0; i < drv->nr; i++)
1906 uart_line_info(m, drv, i);
1907 return 0;
1908}
1909#endif
1910
1911#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1912/**
1913 * uart_console_write - write a console message to a serial port
1914 * @port: the port to write the message
1915 * @s: array of characters
1916 * @count: number of characters in string to write
1917 * @putchar: function to write character to port
1918 */
1919void uart_console_write(struct uart_port *port, const char *s,
1920 unsigned int count,
1921 void (*putchar)(struct uart_port *, int))
1922{
1923 unsigned int i;
1924
1925 for (i = 0; i < count; i++, s++) {
1926 if (*s == '\n')
1927 putchar(port, '\r');
1928 putchar(port, *s);
1929 }
1930}
1931EXPORT_SYMBOL_GPL(uart_console_write);
1932
1933/*
1934 * Check whether an invalid uart number has been specified, and
1935 * if so, search for the first available port that does have
1936 * console support.
1937 */
1938struct uart_port * __init
1939uart_get_console(struct uart_port *ports, int nr, struct console *co)
1940{
1941 int idx = co->index;
1942
1943 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1944 ports[idx].membase == NULL))
1945 for (idx = 0; idx < nr; idx++)
1946 if (ports[idx].iobase != 0 ||
1947 ports[idx].membase != NULL)
1948 break;
1949
1950 co->index = idx;
1951
1952 return ports + idx;
1953}
1954
1955/**
1956 * uart_parse_earlycon - Parse earlycon options
1957 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1958 * @iotype: ptr for decoded iotype (out)
1959 * @addr: ptr for decoded mapbase/iobase (out)
1960 * @options: ptr for <options> field; NULL if not present (out)
1961 *
1962 * Decodes earlycon kernel command line parameters of the form
1963 * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1964 * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1965 *
1966 * The optional form
1967 *
1968 * earlycon=<name>,0x<addr>,<options>
1969 * console=<name>,0x<addr>,<options>
1970 *
1971 * is also accepted; the returned @iotype will be UPIO_MEM.
1972 *
1973 * Returns 0 on success or -EINVAL on failure
1974 */
1975int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
1976 char **options)
1977{
1978 if (strncmp(p, "mmio,", 5) == 0) {
1979 *iotype = UPIO_MEM;
1980 p += 5;
1981 } else if (strncmp(p, "mmio16,", 7) == 0) {
1982 *iotype = UPIO_MEM16;
1983 p += 7;
1984 } else if (strncmp(p, "mmio32,", 7) == 0) {
1985 *iotype = UPIO_MEM32;
1986 p += 7;
1987 } else if (strncmp(p, "mmio32be,", 9) == 0) {
1988 *iotype = UPIO_MEM32BE;
1989 p += 9;
1990 } else if (strncmp(p, "mmio32native,", 13) == 0) {
1991 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
1992 UPIO_MEM32BE : UPIO_MEM32;
1993 p += 13;
1994 } else if (strncmp(p, "io,", 3) == 0) {
1995 *iotype = UPIO_PORT;
1996 p += 3;
1997 } else if (strncmp(p, "0x", 2) == 0) {
1998 *iotype = UPIO_MEM;
1999 } else {
2000 return -EINVAL;
2001 }
2002
2003 /*
2004 * Before you replace it with kstrtoull(), think about options separator
2005 * (',') it will not tolerate
2006 */
2007 *addr = simple_strtoull(p, NULL, 0);
2008 p = strchr(p, ',');
2009 if (p)
2010 p++;
2011
2012 *options = p;
2013 return 0;
2014}
2015EXPORT_SYMBOL_GPL(uart_parse_earlycon);
2016
2017/**
2018 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
2019 * @options: pointer to option string
2020 * @baud: pointer to an 'int' variable for the baud rate.
2021 * @parity: pointer to an 'int' variable for the parity.
2022 * @bits: pointer to an 'int' variable for the number of data bits.
2023 * @flow: pointer to an 'int' variable for the flow control character.
2024 *
2025 * uart_parse_options decodes a string containing the serial console
2026 * options. The format of the string is <baud><parity><bits><flow>,
2027 * eg: 115200n8r
2028 */
2029void
2030uart_parse_options(const char *options, int *baud, int *parity,
2031 int *bits, int *flow)
2032{
2033 const char *s = options;
2034
2035 *baud = simple_strtoul(s, NULL, 10);
2036 while (*s >= '0' && *s <= '9')
2037 s++;
2038 if (*s)
2039 *parity = *s++;
2040 if (*s)
2041 *bits = *s++ - '0';
2042 if (*s)
2043 *flow = *s;
2044}
2045EXPORT_SYMBOL_GPL(uart_parse_options);
2046
2047/**
2048 * uart_set_options - setup the serial console parameters
2049 * @port: pointer to the serial ports uart_port structure
2050 * @co: console pointer
2051 * @baud: baud rate
2052 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
2053 * @bits: number of data bits
2054 * @flow: flow control character - 'r' (rts)
2055 */
2056int
2057uart_set_options(struct uart_port *port, struct console *co,
2058 int baud, int parity, int bits, int flow)
2059{
2060 struct ktermios termios;
2061 static struct ktermios dummy;
2062
2063 /*
2064 * Ensure that the serial console lock is initialised
2065 * early.
2066 * If this port is a console, then the spinlock is already
2067 * initialised.
2068 */
2069 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
2070 spin_lock_init(&port->lock);
2071 lockdep_set_class(&port->lock, &port_lock_key);
2072 }
2073
2074 memset(&termios, 0, sizeof(struct ktermios));
2075
2076 termios.c_cflag |= CREAD | HUPCL | CLOCAL;
2077 tty_termios_encode_baud_rate(&termios, baud, baud);
2078
2079 if (bits == 7)
2080 termios.c_cflag |= CS7;
2081 else
2082 termios.c_cflag |= CS8;
2083
2084 switch (parity) {
2085 case 'o': case 'O':
2086 termios.c_cflag |= PARODD;
2087 /*fall through*/
2088 case 'e': case 'E':
2089 termios.c_cflag |= PARENB;
2090 break;
2091 }
2092
2093 if (flow == 'r')
2094 termios.c_cflag |= CRTSCTS;
2095
2096 /*
2097 * some uarts on other side don't support no flow control.
2098 * So we set * DTR in host uart to make them happy
2099 */
2100 port->mctrl |= TIOCM_DTR;
2101
2102 port->ops->set_termios(port, &termios, &dummy);
2103 /*
2104 * Allow the setting of the UART parameters with a NULL console
2105 * too:
2106 */
2107 if (co)
2108 co->cflag = termios.c_cflag;
2109
2110 return 0;
2111}
2112EXPORT_SYMBOL_GPL(uart_set_options);
2113#endif /* CONFIG_SERIAL_CORE_CONSOLE */
2114
2115/**
2116 * uart_change_pm - set power state of the port
2117 *
2118 * @state: port descriptor
2119 * @pm_state: new state
2120 *
2121 * Locking: port->mutex has to be held
2122 */
2123static void uart_change_pm(struct uart_state *state,
2124 enum uart_pm_state pm_state)
2125{
2126 struct uart_port *port = uart_port_check(state);
2127
2128 if (state->pm_state != pm_state) {
2129 if (port && port->ops->pm)
2130 port->ops->pm(port, pm_state, state->pm_state);
2131 state->pm_state = pm_state;
2132 }
2133}
2134
2135struct uart_match {
2136 struct uart_port *port;
2137 struct uart_driver *driver;
2138};
2139
2140static int serial_match_port(struct device *dev, void *data)
2141{
2142 struct uart_match *match = data;
2143 struct tty_driver *tty_drv = match->driver->tty_driver;
2144 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
2145 match->port->line;
2146
2147 return dev->devt == devt; /* Actually, only one tty per port */
2148}
2149
2150int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
2151{
2152 struct uart_state *state = drv->state + uport->line;
2153 struct tty_port *port = &state->port;
2154 struct device *tty_dev;
2155 struct uart_match match = {uport, drv};
2156
2157 mutex_lock(&port->mutex);
2158
2159 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2160 if (tty_dev && device_may_wakeup(tty_dev)) {
2161 enable_irq_wake(uport->irq);
2162 put_device(tty_dev);
2163 mutex_unlock(&port->mutex);
2164 return 0;
2165 }
2166 put_device(tty_dev);
2167
2168 /* Nothing to do if the console is not suspending */
2169 if (!console_suspend_enabled && uart_console(uport))
2170 goto unlock;
2171
2172 uport->suspended = 1;
2173
2174 if (tty_port_initialized(port)) {
2175 const struct uart_ops *ops = uport->ops;
2176 int tries;
2177
2178 tty_port_set_suspended(port, 1);
2179 tty_port_set_initialized(port, 0);
2180
2181 spin_lock_irq(&uport->lock);
2182 ops->stop_tx(uport);
2183 ops->set_mctrl(uport, 0);
2184 ops->stop_rx(uport);
2185 spin_unlock_irq(&uport->lock);
2186
2187 /*
2188 * Wait for the transmitter to empty.
2189 */
2190 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2191 msleep(10);
2192 if (!tries)
2193 dev_err(uport->dev, "%s: Unable to drain transmitter\n",
2194 uport->name);
2195
2196 ops->shutdown(uport);
2197 }
2198
2199 /*
2200 * Disable the console device before suspending.
2201 */
2202 if (uart_console(uport))
2203 console_stop(uport->cons);
2204
2205 uart_change_pm(state, UART_PM_STATE_OFF);
2206unlock:
2207 mutex_unlock(&port->mutex);
2208
2209 return 0;
2210}
2211
2212int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2213{
2214 struct uart_state *state = drv->state + uport->line;
2215 struct tty_port *port = &state->port;
2216 struct device *tty_dev;
2217 struct uart_match match = {uport, drv};
2218 struct ktermios termios;
2219
2220 mutex_lock(&port->mutex);
2221
2222 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2223 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2224 if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq))))
2225 disable_irq_wake(uport->irq);
2226 put_device(tty_dev);
2227 mutex_unlock(&port->mutex);
2228 return 0;
2229 }
2230 put_device(tty_dev);
2231 uport->suspended = 0;
2232
2233 /*
2234 * Re-enable the console device after suspending.
2235 */
2236 if (uart_console(uport)) {
2237 /*
2238 * First try to use the console cflag setting.
2239 */
2240 memset(&termios, 0, sizeof(struct ktermios));
2241 termios.c_cflag = uport->cons->cflag;
2242
2243 /*
2244 * If that's unset, use the tty termios setting.
2245 */
2246 if (port->tty && termios.c_cflag == 0)
2247 termios = port->tty->termios;
2248
2249 if (console_suspend_enabled)
2250 uart_change_pm(state, UART_PM_STATE_ON);
2251 uport->ops->set_termios(uport, &termios, NULL);
2252 if (console_suspend_enabled)
2253 console_start(uport->cons);
2254 }
2255
2256 if (tty_port_suspended(port)) {
2257 const struct uart_ops *ops = uport->ops;
2258 int ret;
2259
2260 uart_change_pm(state, UART_PM_STATE_ON);
2261 spin_lock_irq(&uport->lock);
2262 ops->set_mctrl(uport, 0);
2263 spin_unlock_irq(&uport->lock);
2264 if (console_suspend_enabled || !uart_console(uport)) {
2265 /* Protected by port mutex for now */
2266 struct tty_struct *tty = port->tty;
2267 ret = ops->startup(uport);
2268 if (ret == 0) {
2269 if (tty)
2270 uart_change_speed(tty, state, NULL);
2271 spin_lock_irq(&uport->lock);
2272 ops->set_mctrl(uport, uport->mctrl);
2273 ops->start_tx(uport);
2274 spin_unlock_irq(&uport->lock);
2275 tty_port_set_initialized(port, 1);
2276 } else {
2277 /*
2278 * Failed to resume - maybe hardware went away?
2279 * Clear the "initialized" flag so we won't try
2280 * to call the low level drivers shutdown method.
2281 */
2282 uart_shutdown(tty, state);
2283 }
2284 }
2285
2286 tty_port_set_suspended(port, 0);
2287 }
2288
2289 mutex_unlock(&port->mutex);
2290
2291 return 0;
2292}
2293
2294static inline void
2295uart_report_port(struct uart_driver *drv, struct uart_port *port)
2296{
2297 char address[64];
2298
2299 switch (port->iotype) {
2300 case UPIO_PORT:
2301 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2302 break;
2303 case UPIO_HUB6:
2304 snprintf(address, sizeof(address),
2305 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2306 break;
2307 case UPIO_MEM:
2308 case UPIO_MEM16:
2309 case UPIO_MEM32:
2310 case UPIO_MEM32BE:
2311 case UPIO_AU:
2312 case UPIO_TSI:
2313 snprintf(address, sizeof(address),
2314 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2315 break;
2316 default:
2317 strlcpy(address, "*unknown*", sizeof(address));
2318 break;
2319 }
2320
2321 pr_info("%s%s%s at %s (irq = %d, base_baud = %d) is a %s\n",
2322 port->dev ? dev_name(port->dev) : "",
2323 port->dev ? ": " : "",
2324 port->name,
2325 address, port->irq, port->uartclk / 16, uart_type(port));
2326}
2327
2328static void
2329uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2330 struct uart_port *port)
2331{
2332 unsigned int flags;
2333
2334 /*
2335 * If there isn't a port here, don't do anything further.
2336 */
2337 if (!port->iobase && !port->mapbase && !port->membase)
2338 return;
2339
2340 /*
2341 * Now do the auto configuration stuff. Note that config_port
2342 * is expected to claim the resources and map the port for us.
2343 */
2344 flags = 0;
2345 if (port->flags & UPF_AUTO_IRQ)
2346 flags |= UART_CONFIG_IRQ;
2347 if (port->flags & UPF_BOOT_AUTOCONF) {
2348 if (!(port->flags & UPF_FIXED_TYPE)) {
2349 port->type = PORT_UNKNOWN;
2350 flags |= UART_CONFIG_TYPE;
2351 }
2352 port->ops->config_port(port, flags);
2353 }
2354
2355 if (port->type != PORT_UNKNOWN) {
2356 unsigned long flags;
2357
2358 uart_report_port(drv, port);
2359
2360 /* Power up port for set_mctrl() */
2361 uart_change_pm(state, UART_PM_STATE_ON);
2362
2363 /*
2364 * Ensure that the modem control lines are de-activated.
2365 * keep the DTR setting that is set in uart_set_options()
2366 * We probably don't need a spinlock around this, but
2367 */
2368 spin_lock_irqsave(&port->lock, flags);
2369 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2370 spin_unlock_irqrestore(&port->lock, flags);
2371
2372 /*
2373 * If this driver supports console, and it hasn't been
2374 * successfully registered yet, try to re-register it.
2375 * It may be that the port was not available.
2376 */
2377 if (port->cons && !(port->cons->flags & CON_ENABLED))
2378 register_console(port->cons);
2379
2380 /*
2381 * Power down all ports by default, except the
2382 * console if we have one.
2383 */
2384 if (!uart_console(port))
2385 uart_change_pm(state, UART_PM_STATE_OFF);
2386 }
2387}
2388
2389#ifdef CONFIG_CONSOLE_POLL
2390
2391static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2392{
2393 struct uart_driver *drv = driver->driver_state;
2394 struct uart_state *state = drv->state + line;
2395 struct tty_port *tport;
2396 struct uart_port *port;
2397 int baud = 9600;
2398 int bits = 8;
2399 int parity = 'n';
2400 int flow = 'n';
2401 int ret = 0;
2402
2403 tport = &state->port;
2404 mutex_lock(&tport->mutex);
2405
2406 port = uart_port_check(state);
2407 if (!port || !(port->ops->poll_get_char && port->ops->poll_put_char)) {
2408 ret = -1;
2409 goto out;
2410 }
2411
2412 if (port->ops->poll_init) {
2413 /*
2414 * We don't set initialized as we only initialized the hw,
2415 * e.g. state->xmit is still uninitialized.
2416 */
2417 if (!tty_port_initialized(tport))
2418 ret = port->ops->poll_init(port);
2419 }
2420
2421 if (!ret && options) {
2422 uart_parse_options(options, &baud, &parity, &bits, &flow);
2423 ret = uart_set_options(port, NULL, baud, parity, bits, flow);
2424 }
2425out:
2426 mutex_unlock(&tport->mutex);
2427 return ret;
2428}
2429
2430static int uart_poll_get_char(struct tty_driver *driver, int line)
2431{
2432 struct uart_driver *drv = driver->driver_state;
2433 struct uart_state *state = drv->state + line;
2434 struct uart_port *port;
2435 int ret = -1;
2436
2437 port = uart_port_ref(state);
2438 if (port) {
2439 ret = port->ops->poll_get_char(port);
2440 uart_port_deref(port);
2441 }
2442
2443 return ret;
2444}
2445
2446static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2447{
2448 struct uart_driver *drv = driver->driver_state;
2449 struct uart_state *state = drv->state + line;
2450 struct uart_port *port;
2451
2452 port = uart_port_ref(state);
2453 if (!port)
2454 return;
2455
2456 if (ch == '\n')
2457 port->ops->poll_put_char(port, '\r');
2458 port->ops->poll_put_char(port, ch);
2459 uart_port_deref(port);
2460}
2461#endif
2462
2463static const struct tty_operations uart_ops = {
2464 .install = uart_install,
2465 .open = uart_open,
2466 .close = uart_close,
2467 .write = uart_write,
2468 .put_char = uart_put_char,
2469 .flush_chars = uart_flush_chars,
2470 .write_room = uart_write_room,
2471 .chars_in_buffer= uart_chars_in_buffer,
2472 .flush_buffer = uart_flush_buffer,
2473 .ioctl = uart_ioctl,
2474 .throttle = uart_throttle,
2475 .unthrottle = uart_unthrottle,
2476 .send_xchar = uart_send_xchar,
2477 .set_termios = uart_set_termios,
2478 .set_ldisc = uart_set_ldisc,
2479 .stop = uart_stop,
2480 .start = uart_start,
2481 .hangup = uart_hangup,
2482 .break_ctl = uart_break_ctl,
2483 .wait_until_sent= uart_wait_until_sent,
2484#ifdef CONFIG_PROC_FS
2485 .proc_show = uart_proc_show,
2486#endif
2487 .tiocmget = uart_tiocmget,
2488 .tiocmset = uart_tiocmset,
2489 .set_serial = uart_set_info_user,
2490 .get_serial = uart_get_info_user,
2491 .get_icount = uart_get_icount,
2492#ifdef CONFIG_CONSOLE_POLL
2493 .poll_init = uart_poll_init,
2494 .poll_get_char = uart_poll_get_char,
2495 .poll_put_char = uart_poll_put_char,
2496#endif
2497};
2498
2499static const struct tty_port_operations uart_port_ops = {
2500 .carrier_raised = uart_carrier_raised,
2501 .dtr_rts = uart_dtr_rts,
2502 .activate = uart_port_activate,
2503 .shutdown = uart_tty_port_shutdown,
2504};
2505
2506/**
2507 * uart_register_driver - register a driver with the uart core layer
2508 * @drv: low level driver structure
2509 *
2510 * Register a uart driver with the core driver. We in turn register
2511 * with the tty layer, and initialise the core driver per-port state.
2512 *
2513 * We have a proc file in /proc/tty/driver which is named after the
2514 * normal driver.
2515 *
2516 * drv->port should be NULL, and the per-port structures should be
2517 * registered using uart_add_one_port after this call has succeeded.
2518 */
2519int uart_register_driver(struct uart_driver *drv)
2520{
2521 struct tty_driver *normal;
2522 int i, retval = -ENOMEM;
2523
2524 BUG_ON(drv->state);
2525
2526 /*
2527 * Maybe we should be using a slab cache for this, especially if
2528 * we have a large number of ports to handle.
2529 */
2530 drv->state = kcalloc(drv->nr, sizeof(struct uart_state), GFP_KERNEL);
2531 if (!drv->state)
2532 goto out;
2533
2534 normal = alloc_tty_driver(drv->nr);
2535 if (!normal)
2536 goto out_kfree;
2537
2538 drv->tty_driver = normal;
2539
2540 normal->driver_name = drv->driver_name;
2541 normal->name = drv->dev_name;
2542 normal->major = drv->major;
2543 normal->minor_start = drv->minor;
2544 normal->type = TTY_DRIVER_TYPE_SERIAL;
2545 normal->subtype = SERIAL_TYPE_NORMAL;
2546 normal->init_termios = tty_std_termios;
2547 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2548 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2549 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2550 normal->driver_state = drv;
2551 tty_set_operations(normal, &uart_ops);
2552
2553 /*
2554 * Initialise the UART state(s).
2555 */
2556 for (i = 0; i < drv->nr; i++) {
2557 struct uart_state *state = drv->state + i;
2558 struct tty_port *port = &state->port;
2559
2560 tty_port_init(port);
2561 port->ops = &uart_port_ops;
2562 }
2563
2564 retval = tty_register_driver(normal);
2565 if (retval >= 0)
2566 return retval;
2567
2568 for (i = 0; i < drv->nr; i++)
2569 tty_port_destroy(&drv->state[i].port);
2570 put_tty_driver(normal);
2571out_kfree:
2572 kfree(drv->state);
2573out:
2574 return retval;
2575}
2576
2577/**
2578 * uart_unregister_driver - remove a driver from the uart core layer
2579 * @drv: low level driver structure
2580 *
2581 * Remove all references to a driver from the core driver. The low
2582 * level driver must have removed all its ports via the
2583 * uart_remove_one_port() if it registered them with uart_add_one_port().
2584 * (ie, drv->port == NULL)
2585 */
2586void uart_unregister_driver(struct uart_driver *drv)
2587{
2588 struct tty_driver *p = drv->tty_driver;
2589 unsigned int i;
2590
2591 tty_unregister_driver(p);
2592 put_tty_driver(p);
2593 for (i = 0; i < drv->nr; i++)
2594 tty_port_destroy(&drv->state[i].port);
2595 kfree(drv->state);
2596 drv->state = NULL;
2597 drv->tty_driver = NULL;
2598}
2599
2600struct tty_driver *uart_console_device(struct console *co, int *index)
2601{
2602 struct uart_driver *p = co->data;
2603 *index = co->index;
2604 return p->tty_driver;
2605}
2606
2607static ssize_t uart_get_attr_uartclk(struct device *dev,
2608 struct device_attribute *attr, char *buf)
2609{
2610 struct serial_struct tmp;
2611 struct tty_port *port = dev_get_drvdata(dev);
2612
2613 uart_get_info(port, &tmp);
2614 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2615}
2616
2617static ssize_t uart_get_attr_type(struct device *dev,
2618 struct device_attribute *attr, char *buf)
2619{
2620 struct serial_struct tmp;
2621 struct tty_port *port = dev_get_drvdata(dev);
2622
2623 uart_get_info(port, &tmp);
2624 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2625}
2626static ssize_t uart_get_attr_line(struct device *dev,
2627 struct device_attribute *attr, char *buf)
2628{
2629 struct serial_struct tmp;
2630 struct tty_port *port = dev_get_drvdata(dev);
2631
2632 uart_get_info(port, &tmp);
2633 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2634}
2635
2636static ssize_t uart_get_attr_port(struct device *dev,
2637 struct device_attribute *attr, char *buf)
2638{
2639 struct serial_struct tmp;
2640 struct tty_port *port = dev_get_drvdata(dev);
2641 unsigned long ioaddr;
2642
2643 uart_get_info(port, &tmp);
2644 ioaddr = tmp.port;
2645 if (HIGH_BITS_OFFSET)
2646 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2647 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2648}
2649
2650static ssize_t uart_get_attr_irq(struct device *dev,
2651 struct device_attribute *attr, char *buf)
2652{
2653 struct serial_struct tmp;
2654 struct tty_port *port = dev_get_drvdata(dev);
2655
2656 uart_get_info(port, &tmp);
2657 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2658}
2659
2660static ssize_t uart_get_attr_flags(struct device *dev,
2661 struct device_attribute *attr, char *buf)
2662{
2663 struct serial_struct tmp;
2664 struct tty_port *port = dev_get_drvdata(dev);
2665
2666 uart_get_info(port, &tmp);
2667 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2668}
2669
2670static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2671 struct device_attribute *attr, char *buf)
2672{
2673 struct serial_struct tmp;
2674 struct tty_port *port = dev_get_drvdata(dev);
2675
2676 uart_get_info(port, &tmp);
2677 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2678}
2679
2680
2681static ssize_t uart_get_attr_close_delay(struct device *dev,
2682 struct device_attribute *attr, char *buf)
2683{
2684 struct serial_struct tmp;
2685 struct tty_port *port = dev_get_drvdata(dev);
2686
2687 uart_get_info(port, &tmp);
2688 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2689}
2690
2691
2692static ssize_t uart_get_attr_closing_wait(struct device *dev,
2693 struct device_attribute *attr, char *buf)
2694{
2695 struct serial_struct tmp;
2696 struct tty_port *port = dev_get_drvdata(dev);
2697
2698 uart_get_info(port, &tmp);
2699 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2700}
2701
2702static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2703 struct device_attribute *attr, char *buf)
2704{
2705 struct serial_struct tmp;
2706 struct tty_port *port = dev_get_drvdata(dev);
2707
2708 uart_get_info(port, &tmp);
2709 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2710}
2711
2712static ssize_t uart_get_attr_io_type(struct device *dev,
2713 struct device_attribute *attr, char *buf)
2714{
2715 struct serial_struct tmp;
2716 struct tty_port *port = dev_get_drvdata(dev);
2717
2718 uart_get_info(port, &tmp);
2719 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2720}
2721
2722static ssize_t uart_get_attr_iomem_base(struct device *dev,
2723 struct device_attribute *attr, char *buf)
2724{
2725 struct serial_struct tmp;
2726 struct tty_port *port = dev_get_drvdata(dev);
2727
2728 uart_get_info(port, &tmp);
2729 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2730}
2731
2732static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2733 struct device_attribute *attr, char *buf)
2734{
2735 struct serial_struct tmp;
2736 struct tty_port *port = dev_get_drvdata(dev);
2737
2738 uart_get_info(port, &tmp);
2739 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2740}
2741
2742static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2743static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2744static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2745static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2746static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2747static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2748static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2749static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2750static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2751static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2752static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2753static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2754static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2755
2756static struct attribute *tty_dev_attrs[] = {
2757 &dev_attr_type.attr,
2758 &dev_attr_line.attr,
2759 &dev_attr_port.attr,
2760 &dev_attr_irq.attr,
2761 &dev_attr_flags.attr,
2762 &dev_attr_xmit_fifo_size.attr,
2763 &dev_attr_uartclk.attr,
2764 &dev_attr_close_delay.attr,
2765 &dev_attr_closing_wait.attr,
2766 &dev_attr_custom_divisor.attr,
2767 &dev_attr_io_type.attr,
2768 &dev_attr_iomem_base.attr,
2769 &dev_attr_iomem_reg_shift.attr,
2770 NULL,
2771 };
2772
2773static const struct attribute_group tty_dev_attr_group = {
2774 .attrs = tty_dev_attrs,
2775 };
2776
2777/**
2778 * uart_add_one_port - attach a driver-defined port structure
2779 * @drv: pointer to the uart low level driver structure for this port
2780 * @uport: uart port structure to use for this port.
2781 *
2782 * This allows the driver to register its own uart_port structure
2783 * with the core driver. The main purpose is to allow the low
2784 * level uart drivers to expand uart_port, rather than having yet
2785 * more levels of structures.
2786 */
2787int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2788{
2789 struct uart_state *state;
2790 struct tty_port *port;
2791 int ret = 0;
2792 struct device *tty_dev;
2793 int num_groups;
2794
2795 BUG_ON(in_interrupt());
2796
2797 if (uport->line >= drv->nr)
2798 return -EINVAL;
2799
2800 state = drv->state + uport->line;
2801 port = &state->port;
2802
2803 mutex_lock(&port_mutex);
2804 mutex_lock(&port->mutex);
2805 if (state->uart_port) {
2806 ret = -EINVAL;
2807 goto out;
2808 }
2809
2810 /* Link the port to the driver state table and vice versa */
2811 atomic_set(&state->refcount, 1);
2812 init_waitqueue_head(&state->remove_wait);
2813 state->uart_port = uport;
2814 uport->state = state;
2815
2816 state->pm_state = UART_PM_STATE_UNDEFINED;
2817 uport->cons = drv->cons;
2818 uport->minor = drv->tty_driver->minor_start + uport->line;
2819 uport->name = kasprintf(GFP_KERNEL, "%s%d", drv->dev_name,
2820 drv->tty_driver->name_base + uport->line);
2821 if (!uport->name) {
2822 ret = -ENOMEM;
2823 goto out;
2824 }
2825
2826 /*
2827 * If this port is a console, then the spinlock is already
2828 * initialised.
2829 */
2830 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2831 spin_lock_init(&uport->lock);
2832 lockdep_set_class(&uport->lock, &port_lock_key);
2833 }
2834 if (uport->cons && uport->dev)
2835 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2836
2837 uart_configure_port(drv, state, uport);
2838
2839 port->console = uart_console(uport);
2840
2841 num_groups = 2;
2842 if (uport->attr_group)
2843 num_groups++;
2844
2845 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2846 GFP_KERNEL);
2847 if (!uport->tty_groups) {
2848 ret = -ENOMEM;
2849 goto out;
2850 }
2851 uport->tty_groups[0] = &tty_dev_attr_group;
2852 if (uport->attr_group)
2853 uport->tty_groups[1] = uport->attr_group;
2854
2855 /*
2856 * Register the port whether it's detected or not. This allows
2857 * setserial to be used to alter this port's parameters.
2858 */
2859 tty_dev = tty_port_register_device_attr_serdev(port, drv->tty_driver,
2860 uport->line, uport->dev, port, uport->tty_groups);
2861 if (!IS_ERR(tty_dev)) {
2862 device_set_wakeup_capable(tty_dev, 1);
2863 } else {
2864 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2865 uport->line);
2866 }
2867
2868 /*
2869 * Ensure UPF_DEAD is not set.
2870 */
2871 uport->flags &= ~UPF_DEAD;
2872
2873 out:
2874 mutex_unlock(&port->mutex);
2875 mutex_unlock(&port_mutex);
2876
2877 return ret;
2878}
2879
2880/**
2881 * uart_remove_one_port - detach a driver defined port structure
2882 * @drv: pointer to the uart low level driver structure for this port
2883 * @uport: uart port structure for this port
2884 *
2885 * This unhooks (and hangs up) the specified port structure from the
2886 * core driver. No further calls will be made to the low-level code
2887 * for this port.
2888 */
2889int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2890{
2891 struct uart_state *state = drv->state + uport->line;
2892 struct tty_port *port = &state->port;
2893 struct uart_port *uart_port;
2894 struct tty_struct *tty;
2895 int ret = 0;
2896
2897 BUG_ON(in_interrupt());
2898
2899 mutex_lock(&port_mutex);
2900
2901 /*
2902 * Mark the port "dead" - this prevents any opens from
2903 * succeeding while we shut down the port.
2904 */
2905 mutex_lock(&port->mutex);
2906 uart_port = uart_port_check(state);
2907 if (uart_port != uport)
2908 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2909 uart_port, uport);
2910
2911 if (!uart_port) {
2912 mutex_unlock(&port->mutex);
2913 ret = -EINVAL;
2914 goto out;
2915 }
2916 uport->flags |= UPF_DEAD;
2917 mutex_unlock(&port->mutex);
2918
2919 /*
2920 * Remove the devices from the tty layer
2921 */
2922 tty_port_unregister_device(port, drv->tty_driver, uport->line);
2923
2924 tty = tty_port_tty_get(port);
2925 if (tty) {
2926 tty_vhangup(port->tty);
2927 tty_kref_put(tty);
2928 }
2929
2930 /*
2931 * If the port is used as a console, unregister it
2932 */
2933 if (uart_console(uport))
2934 unregister_console(uport->cons);
2935
2936 /*
2937 * Free the port IO and memory resources, if any.
2938 */
2939 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
2940 uport->ops->release_port(uport);
2941 kfree(uport->tty_groups);
2942 kfree(uport->name);
2943
2944 /*
2945 * Indicate that there isn't a port here anymore.
2946 */
2947 uport->type = PORT_UNKNOWN;
2948
2949 mutex_lock(&port->mutex);
2950 WARN_ON(atomic_dec_return(&state->refcount) < 0);
2951 wait_event(state->remove_wait, !atomic_read(&state->refcount));
2952 state->uart_port = NULL;
2953 mutex_unlock(&port->mutex);
2954out:
2955 mutex_unlock(&port_mutex);
2956
2957 return ret;
2958}
2959
2960/*
2961 * Are the two ports equivalent?
2962 */
2963int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2964{
2965 if (port1->iotype != port2->iotype)
2966 return 0;
2967
2968 switch (port1->iotype) {
2969 case UPIO_PORT:
2970 return (port1->iobase == port2->iobase);
2971 case UPIO_HUB6:
2972 return (port1->iobase == port2->iobase) &&
2973 (port1->hub6 == port2->hub6);
2974 case UPIO_MEM:
2975 case UPIO_MEM16:
2976 case UPIO_MEM32:
2977 case UPIO_MEM32BE:
2978 case UPIO_AU:
2979 case UPIO_TSI:
2980 return (port1->mapbase == port2->mapbase);
2981 }
2982 return 0;
2983}
2984EXPORT_SYMBOL(uart_match_port);
2985
2986/**
2987 * uart_handle_dcd_change - handle a change of carrier detect state
2988 * @uport: uart_port structure for the open port
2989 * @status: new carrier detect status, nonzero if active
2990 *
2991 * Caller must hold uport->lock
2992 */
2993void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2994{
2995 struct tty_port *port = &uport->state->port;
2996 struct tty_struct *tty = port->tty;
2997 struct tty_ldisc *ld;
2998
2999 lockdep_assert_held_once(&uport->lock);
3000
3001 if (tty) {
3002 ld = tty_ldisc_ref(tty);
3003 if (ld) {
3004 if (ld->ops->dcd_change)
3005 ld->ops->dcd_change(tty, status);
3006 tty_ldisc_deref(ld);
3007 }
3008 }
3009
3010 uport->icount.dcd++;
3011
3012 if (uart_dcd_enabled(uport)) {
3013 if (status)
3014 wake_up_interruptible(&port->open_wait);
3015 else if (tty)
3016 tty_hangup(tty);
3017 }
3018}
3019EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
3020
3021/**
3022 * uart_handle_cts_change - handle a change of clear-to-send state
3023 * @uport: uart_port structure for the open port
3024 * @status: new clear to send status, nonzero if active
3025 *
3026 * Caller must hold uport->lock
3027 */
3028void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
3029{
3030 lockdep_assert_held_once(&uport->lock);
3031
3032 uport->icount.cts++;
3033
3034 if (uart_softcts_mode(uport)) {
3035 if (uport->hw_stopped) {
3036 if (status) {
3037 uport->hw_stopped = 0;
3038 uport->ops->start_tx(uport);
3039 uart_write_wakeup(uport);
3040 }
3041 } else {
3042 if (!status) {
3043 uport->hw_stopped = 1;
3044 uport->ops->stop_tx(uport);
3045 }
3046 }
3047
3048 }
3049}
3050EXPORT_SYMBOL_GPL(uart_handle_cts_change);
3051
3052/**
3053 * uart_insert_char - push a char to the uart layer
3054 *
3055 * User is responsible to call tty_flip_buffer_push when they are done with
3056 * insertion.
3057 *
3058 * @port: corresponding port
3059 * @status: state of the serial port RX buffer (LSR for 8250)
3060 * @overrun: mask of overrun bits in @status
3061 * @ch: character to push
3062 * @flag: flag for the character (see TTY_NORMAL and friends)
3063 */
3064void uart_insert_char(struct uart_port *port, unsigned int status,
3065 unsigned int overrun, unsigned int ch, unsigned int flag)
3066{
3067 struct tty_port *tport = &port->state->port;
3068
3069 if ((status & port->ignore_status_mask & ~overrun) == 0)
3070 if (tty_insert_flip_char(tport, ch, flag) == 0)
3071 ++port->icount.buf_overrun;
3072
3073 /*
3074 * Overrun is special. Since it's reported immediately,
3075 * it doesn't affect the current character.
3076 */
3077 if (status & ~port->ignore_status_mask & overrun)
3078 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
3079 ++port->icount.buf_overrun;
3080}
3081EXPORT_SYMBOL_GPL(uart_insert_char);
3082
3083EXPORT_SYMBOL(uart_write_wakeup);
3084EXPORT_SYMBOL(uart_register_driver);
3085EXPORT_SYMBOL(uart_unregister_driver);
3086EXPORT_SYMBOL(uart_suspend_port);
3087EXPORT_SYMBOL(uart_resume_port);
3088EXPORT_SYMBOL(uart_add_one_port);
3089EXPORT_SYMBOL(uart_remove_one_port);
3090
3091/**
3092 * uart_get_rs485_mode() - retrieve rs485 properties for given uart
3093 * @dev: uart device
3094 * @rs485conf: output parameter
3095 *
3096 * This function implements the device tree binding described in
3097 * Documentation/devicetree/bindings/serial/rs485.txt.
3098 */
3099void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf)
3100{
3101 u32 rs485_delay[2];
3102 int ret;
3103
3104 ret = device_property_read_u32_array(dev, "rs485-rts-delay",
3105 rs485_delay, 2);
3106 if (!ret) {
3107 rs485conf->delay_rts_before_send = rs485_delay[0];
3108 rs485conf->delay_rts_after_send = rs485_delay[1];
3109 } else {
3110 rs485conf->delay_rts_before_send = 0;
3111 rs485conf->delay_rts_after_send = 0;
3112 }
3113
3114 /*
3115 * Clear full-duplex and enabled flags, set RTS polarity to active high
3116 * to get to a defined state with the following properties:
3117 */
3118 rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED |
3119 SER_RS485_RTS_AFTER_SEND);
3120 rs485conf->flags |= SER_RS485_RTS_ON_SEND;
3121
3122 if (device_property_read_bool(dev, "rs485-rx-during-tx"))
3123 rs485conf->flags |= SER_RS485_RX_DURING_TX;
3124
3125 if (device_property_read_bool(dev, "linux,rs485-enabled-at-boot-time"))
3126 rs485conf->flags |= SER_RS485_ENABLED;
3127
3128 if (device_property_read_bool(dev, "rs485-rts-active-low")) {
3129 rs485conf->flags &= ~SER_RS485_RTS_ON_SEND;
3130 rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
3131 }
3132}
3133EXPORT_SYMBOL_GPL(uart_get_rs485_mode);
3134
3135MODULE_DESCRIPTION("Serial driver core");
3136MODULE_LICENSE("GPL");
1/*
2 * Driver core for serial ports
3 *
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
5 *
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 */
23#include <linux/module.h>
24#include <linux/tty.h>
25#include <linux/tty_flip.h>
26#include <linux/slab.h>
27#include <linux/init.h>
28#include <linux/console.h>
29#include <linux/of.h>
30#include <linux/proc_fs.h>
31#include <linux/seq_file.h>
32#include <linux/device.h>
33#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
34#include <linux/serial_core.h>
35#include <linux/delay.h>
36#include <linux/mutex.h>
37
38#include <asm/irq.h>
39#include <asm/uaccess.h>
40
41/*
42 * This is used to lock changes in serial line configuration.
43 */
44static DEFINE_MUTEX(port_mutex);
45
46/*
47 * lockdep: port->lock is initialized in two places, but we
48 * want only one lock-class:
49 */
50static struct lock_class_key port_lock_key;
51
52#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
53
54static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
55 struct ktermios *old_termios);
56static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
57static void uart_change_pm(struct uart_state *state,
58 enum uart_pm_state pm_state);
59
60static void uart_port_shutdown(struct tty_port *port);
61
62static int uart_dcd_enabled(struct uart_port *uport)
63{
64 return !!(uport->status & UPSTAT_DCD_ENABLE);
65}
66
67/*
68 * This routine is used by the interrupt handler to schedule processing in
69 * the software interrupt portion of the driver.
70 */
71void uart_write_wakeup(struct uart_port *port)
72{
73 struct uart_state *state = port->state;
74 /*
75 * This means you called this function _after_ the port was
76 * closed. No cookie for you.
77 */
78 BUG_ON(!state);
79 tty_wakeup(state->port.tty);
80}
81
82static void uart_stop(struct tty_struct *tty)
83{
84 struct uart_state *state = tty->driver_data;
85 struct uart_port *port = state->uart_port;
86 unsigned long flags;
87
88 spin_lock_irqsave(&port->lock, flags);
89 port->ops->stop_tx(port);
90 spin_unlock_irqrestore(&port->lock, flags);
91}
92
93static void __uart_start(struct tty_struct *tty)
94{
95 struct uart_state *state = tty->driver_data;
96 struct uart_port *port = state->uart_port;
97
98 if (!uart_tx_stopped(port))
99 port->ops->start_tx(port);
100}
101
102static void uart_start(struct tty_struct *tty)
103{
104 struct uart_state *state = tty->driver_data;
105 struct uart_port *port = state->uart_port;
106 unsigned long flags;
107
108 spin_lock_irqsave(&port->lock, flags);
109 __uart_start(tty);
110 spin_unlock_irqrestore(&port->lock, flags);
111}
112
113static void
114uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
115{
116 unsigned long flags;
117 unsigned int old;
118
119 spin_lock_irqsave(&port->lock, flags);
120 old = port->mctrl;
121 port->mctrl = (old & ~clear) | set;
122 if (old != port->mctrl)
123 port->ops->set_mctrl(port, port->mctrl);
124 spin_unlock_irqrestore(&port->lock, flags);
125}
126
127#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
128#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
129
130/*
131 * Startup the port. This will be called once per open. All calls
132 * will be serialised by the per-port mutex.
133 */
134static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
135 int init_hw)
136{
137 struct uart_port *uport = state->uart_port;
138 unsigned long page;
139 int retval = 0;
140
141 if (uport->type == PORT_UNKNOWN)
142 return 1;
143
144 /*
145 * Make sure the device is in D0 state.
146 */
147 uart_change_pm(state, UART_PM_STATE_ON);
148
149 /*
150 * Initialise and allocate the transmit and temporary
151 * buffer.
152 */
153 if (!state->xmit.buf) {
154 /* This is protected by the per port mutex */
155 page = get_zeroed_page(GFP_KERNEL);
156 if (!page)
157 return -ENOMEM;
158
159 state->xmit.buf = (unsigned char *) page;
160 uart_circ_clear(&state->xmit);
161 }
162
163 retval = uport->ops->startup(uport);
164 if (retval == 0) {
165 if (uart_console(uport) && uport->cons->cflag) {
166 tty->termios.c_cflag = uport->cons->cflag;
167 uport->cons->cflag = 0;
168 }
169 /*
170 * Initialise the hardware port settings.
171 */
172 uart_change_speed(tty, state, NULL);
173
174 /*
175 * Setup the RTS and DTR signals once the
176 * port is open and ready to respond.
177 */
178 if (init_hw && C_BAUD(tty))
179 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
180 }
181
182 /*
183 * This is to allow setserial on this port. People may want to set
184 * port/irq/type and then reconfigure the port properly if it failed
185 * now.
186 */
187 if (retval && capable(CAP_SYS_ADMIN))
188 return 1;
189
190 return retval;
191}
192
193static int uart_startup(struct tty_struct *tty, struct uart_state *state,
194 int init_hw)
195{
196 struct tty_port *port = &state->port;
197 int retval;
198
199 if (port->flags & ASYNC_INITIALIZED)
200 return 0;
201
202 /*
203 * Set the TTY IO error marker - we will only clear this
204 * once we have successfully opened the port.
205 */
206 set_bit(TTY_IO_ERROR, &tty->flags);
207
208 retval = uart_port_startup(tty, state, init_hw);
209 if (!retval) {
210 set_bit(ASYNCB_INITIALIZED, &port->flags);
211 clear_bit(TTY_IO_ERROR, &tty->flags);
212 } else if (retval > 0)
213 retval = 0;
214
215 return retval;
216}
217
218/*
219 * This routine will shutdown a serial port; interrupts are disabled, and
220 * DTR is dropped if the hangup on close termio flag is on. Calls to
221 * uart_shutdown are serialised by the per-port semaphore.
222 */
223static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
224{
225 struct uart_port *uport = state->uart_port;
226 struct tty_port *port = &state->port;
227
228 /*
229 * Set the TTY IO error marker
230 */
231 if (tty)
232 set_bit(TTY_IO_ERROR, &tty->flags);
233
234 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
235 /*
236 * Turn off DTR and RTS early.
237 */
238 if (uart_console(uport) && tty)
239 uport->cons->cflag = tty->termios.c_cflag;
240
241 if (!tty || C_HUPCL(tty))
242 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
243
244 uart_port_shutdown(port);
245 }
246
247 /*
248 * It's possible for shutdown to be called after suspend if we get
249 * a DCD drop (hangup) at just the right time. Clear suspended bit so
250 * we don't try to resume a port that has been shutdown.
251 */
252 clear_bit(ASYNCB_SUSPENDED, &port->flags);
253
254 /*
255 * Free the transmit buffer page.
256 */
257 if (state->xmit.buf) {
258 free_page((unsigned long)state->xmit.buf);
259 state->xmit.buf = NULL;
260 }
261}
262
263/**
264 * uart_update_timeout - update per-port FIFO timeout.
265 * @port: uart_port structure describing the port
266 * @cflag: termios cflag value
267 * @baud: speed of the port
268 *
269 * Set the port FIFO timeout value. The @cflag value should
270 * reflect the actual hardware settings.
271 */
272void
273uart_update_timeout(struct uart_port *port, unsigned int cflag,
274 unsigned int baud)
275{
276 unsigned int bits;
277
278 /* byte size and parity */
279 switch (cflag & CSIZE) {
280 case CS5:
281 bits = 7;
282 break;
283 case CS6:
284 bits = 8;
285 break;
286 case CS7:
287 bits = 9;
288 break;
289 default:
290 bits = 10;
291 break; /* CS8 */
292 }
293
294 if (cflag & CSTOPB)
295 bits++;
296 if (cflag & PARENB)
297 bits++;
298
299 /*
300 * The total number of bits to be transmitted in the fifo.
301 */
302 bits = bits * port->fifosize;
303
304 /*
305 * Figure the timeout to send the above number of bits.
306 * Add .02 seconds of slop
307 */
308 port->timeout = (HZ * bits) / baud + HZ/50;
309}
310
311EXPORT_SYMBOL(uart_update_timeout);
312
313/**
314 * uart_get_baud_rate - return baud rate for a particular port
315 * @port: uart_port structure describing the port in question.
316 * @termios: desired termios settings.
317 * @old: old termios (or NULL)
318 * @min: minimum acceptable baud rate
319 * @max: maximum acceptable baud rate
320 *
321 * Decode the termios structure into a numeric baud rate,
322 * taking account of the magic 38400 baud rate (with spd_*
323 * flags), and mapping the %B0 rate to 9600 baud.
324 *
325 * If the new baud rate is invalid, try the old termios setting.
326 * If it's still invalid, we try 9600 baud.
327 *
328 * Update the @termios structure to reflect the baud rate
329 * we're actually going to be using. Don't do this for the case
330 * where B0 is requested ("hang up").
331 */
332unsigned int
333uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
334 struct ktermios *old, unsigned int min, unsigned int max)
335{
336 unsigned int try;
337 unsigned int baud;
338 unsigned int altbaud;
339 int hung_up = 0;
340 upf_t flags = port->flags & UPF_SPD_MASK;
341
342 switch (flags) {
343 case UPF_SPD_HI:
344 altbaud = 57600;
345 break;
346 case UPF_SPD_VHI:
347 altbaud = 115200;
348 break;
349 case UPF_SPD_SHI:
350 altbaud = 230400;
351 break;
352 case UPF_SPD_WARP:
353 altbaud = 460800;
354 break;
355 default:
356 altbaud = 38400;
357 break;
358 }
359
360 for (try = 0; try < 2; try++) {
361 baud = tty_termios_baud_rate(termios);
362
363 /*
364 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
365 * Die! Die! Die!
366 */
367 if (try == 0 && baud == 38400)
368 baud = altbaud;
369
370 /*
371 * Special case: B0 rate.
372 */
373 if (baud == 0) {
374 hung_up = 1;
375 baud = 9600;
376 }
377
378 if (baud >= min && baud <= max)
379 return baud;
380
381 /*
382 * Oops, the quotient was zero. Try again with
383 * the old baud rate if possible.
384 */
385 termios->c_cflag &= ~CBAUD;
386 if (old) {
387 baud = tty_termios_baud_rate(old);
388 if (!hung_up)
389 tty_termios_encode_baud_rate(termios,
390 baud, baud);
391 old = NULL;
392 continue;
393 }
394
395 /*
396 * As a last resort, if the range cannot be met then clip to
397 * the nearest chip supported rate.
398 */
399 if (!hung_up) {
400 if (baud <= min)
401 tty_termios_encode_baud_rate(termios,
402 min + 1, min + 1);
403 else
404 tty_termios_encode_baud_rate(termios,
405 max - 1, max - 1);
406 }
407 }
408 /* Should never happen */
409 WARN_ON(1);
410 return 0;
411}
412
413EXPORT_SYMBOL(uart_get_baud_rate);
414
415/**
416 * uart_get_divisor - return uart clock divisor
417 * @port: uart_port structure describing the port.
418 * @baud: desired baud rate
419 *
420 * Calculate the uart clock divisor for the port.
421 */
422unsigned int
423uart_get_divisor(struct uart_port *port, unsigned int baud)
424{
425 unsigned int quot;
426
427 /*
428 * Old custom speed handling.
429 */
430 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
431 quot = port->custom_divisor;
432 else
433 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
434
435 return quot;
436}
437
438EXPORT_SYMBOL(uart_get_divisor);
439
440/* Caller holds port mutex */
441static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
442 struct ktermios *old_termios)
443{
444 struct uart_port *uport = state->uart_port;
445 struct ktermios *termios;
446 int hw_stopped;
447
448 /*
449 * If we have no tty, termios, or the port does not exist,
450 * then we can't set the parameters for this port.
451 */
452 if (!tty || uport->type == PORT_UNKNOWN)
453 return;
454
455 termios = &tty->termios;
456 uport->ops->set_termios(uport, termios, old_termios);
457
458 /*
459 * Set modem status enables based on termios cflag
460 */
461 spin_lock_irq(&uport->lock);
462 if (termios->c_cflag & CRTSCTS)
463 uport->status |= UPSTAT_CTS_ENABLE;
464 else
465 uport->status &= ~UPSTAT_CTS_ENABLE;
466
467 if (termios->c_cflag & CLOCAL)
468 uport->status &= ~UPSTAT_DCD_ENABLE;
469 else
470 uport->status |= UPSTAT_DCD_ENABLE;
471
472 /* reset sw-assisted CTS flow control based on (possibly) new mode */
473 hw_stopped = uport->hw_stopped;
474 uport->hw_stopped = uart_softcts_mode(uport) &&
475 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
476 if (uport->hw_stopped) {
477 if (!hw_stopped)
478 uport->ops->stop_tx(uport);
479 } else {
480 if (hw_stopped)
481 __uart_start(tty);
482 }
483 spin_unlock_irq(&uport->lock);
484}
485
486static int uart_put_char(struct tty_struct *tty, unsigned char c)
487{
488 struct uart_state *state = tty->driver_data;
489 struct uart_port *port = state->uart_port;
490 struct circ_buf *circ;
491 unsigned long flags;
492 int ret = 0;
493
494 circ = &state->xmit;
495 if (!circ->buf)
496 return 0;
497
498 spin_lock_irqsave(&port->lock, flags);
499 if (uart_circ_chars_free(circ) != 0) {
500 circ->buf[circ->head] = c;
501 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
502 ret = 1;
503 }
504 spin_unlock_irqrestore(&port->lock, flags);
505 return ret;
506}
507
508static void uart_flush_chars(struct tty_struct *tty)
509{
510 uart_start(tty);
511}
512
513static int uart_write(struct tty_struct *tty,
514 const unsigned char *buf, int count)
515{
516 struct uart_state *state = tty->driver_data;
517 struct uart_port *port;
518 struct circ_buf *circ;
519 unsigned long flags;
520 int c, ret = 0;
521
522 /*
523 * This means you called this function _after_ the port was
524 * closed. No cookie for you.
525 */
526 if (!state) {
527 WARN_ON(1);
528 return -EL3HLT;
529 }
530
531 port = state->uart_port;
532 circ = &state->xmit;
533
534 if (!circ->buf)
535 return 0;
536
537 spin_lock_irqsave(&port->lock, flags);
538 while (1) {
539 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
540 if (count < c)
541 c = count;
542 if (c <= 0)
543 break;
544 memcpy(circ->buf + circ->head, buf, c);
545 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
546 buf += c;
547 count -= c;
548 ret += c;
549 }
550
551 __uart_start(tty);
552 spin_unlock_irqrestore(&port->lock, flags);
553
554 return ret;
555}
556
557static int uart_write_room(struct tty_struct *tty)
558{
559 struct uart_state *state = tty->driver_data;
560 unsigned long flags;
561 int ret;
562
563 spin_lock_irqsave(&state->uart_port->lock, flags);
564 ret = uart_circ_chars_free(&state->xmit);
565 spin_unlock_irqrestore(&state->uart_port->lock, flags);
566 return ret;
567}
568
569static int uart_chars_in_buffer(struct tty_struct *tty)
570{
571 struct uart_state *state = tty->driver_data;
572 unsigned long flags;
573 int ret;
574
575 spin_lock_irqsave(&state->uart_port->lock, flags);
576 ret = uart_circ_chars_pending(&state->xmit);
577 spin_unlock_irqrestore(&state->uart_port->lock, flags);
578 return ret;
579}
580
581static void uart_flush_buffer(struct tty_struct *tty)
582{
583 struct uart_state *state = tty->driver_data;
584 struct uart_port *port;
585 unsigned long flags;
586
587 /*
588 * This means you called this function _after_ the port was
589 * closed. No cookie for you.
590 */
591 if (!state) {
592 WARN_ON(1);
593 return;
594 }
595
596 port = state->uart_port;
597 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
598
599 spin_lock_irqsave(&port->lock, flags);
600 uart_circ_clear(&state->xmit);
601 if (port->ops->flush_buffer)
602 port->ops->flush_buffer(port);
603 spin_unlock_irqrestore(&port->lock, flags);
604 tty_wakeup(tty);
605}
606
607/*
608 * This function is used to send a high-priority XON/XOFF character to
609 * the device
610 */
611static void uart_send_xchar(struct tty_struct *tty, char ch)
612{
613 struct uart_state *state = tty->driver_data;
614 struct uart_port *port = state->uart_port;
615 unsigned long flags;
616
617 if (port->ops->send_xchar)
618 port->ops->send_xchar(port, ch);
619 else {
620 spin_lock_irqsave(&port->lock, flags);
621 port->x_char = ch;
622 if (ch)
623 port->ops->start_tx(port);
624 spin_unlock_irqrestore(&port->lock, flags);
625 }
626}
627
628static void uart_throttle(struct tty_struct *tty)
629{
630 struct uart_state *state = tty->driver_data;
631 struct uart_port *port = state->uart_port;
632 upstat_t mask = 0;
633
634 if (I_IXOFF(tty))
635 mask |= UPSTAT_AUTOXOFF;
636 if (C_CRTSCTS(tty))
637 mask |= UPSTAT_AUTORTS;
638
639 if (port->status & mask) {
640 port->ops->throttle(port);
641 mask &= ~port->status;
642 }
643
644 if (mask & UPSTAT_AUTORTS)
645 uart_clear_mctrl(port, TIOCM_RTS);
646
647 if (mask & UPSTAT_AUTOXOFF)
648 uart_send_xchar(tty, STOP_CHAR(tty));
649}
650
651static void uart_unthrottle(struct tty_struct *tty)
652{
653 struct uart_state *state = tty->driver_data;
654 struct uart_port *port = state->uart_port;
655 upstat_t mask = 0;
656
657 if (I_IXOFF(tty))
658 mask |= UPSTAT_AUTOXOFF;
659 if (C_CRTSCTS(tty))
660 mask |= UPSTAT_AUTORTS;
661
662 if (port->status & mask) {
663 port->ops->unthrottle(port);
664 mask &= ~port->status;
665 }
666
667 if (mask & UPSTAT_AUTORTS)
668 uart_set_mctrl(port, TIOCM_RTS);
669
670 if (mask & UPSTAT_AUTOXOFF)
671 uart_send_xchar(tty, START_CHAR(tty));
672}
673
674static void uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
675{
676 struct uart_state *state = container_of(port, struct uart_state, port);
677 struct uart_port *uport = state->uart_port;
678
679 memset(retinfo, 0, sizeof(*retinfo));
680
681 /*
682 * Ensure the state we copy is consistent and no hardware changes
683 * occur as we go
684 */
685 mutex_lock(&port->mutex);
686 retinfo->type = uport->type;
687 retinfo->line = uport->line;
688 retinfo->port = uport->iobase;
689 if (HIGH_BITS_OFFSET)
690 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
691 retinfo->irq = uport->irq;
692 retinfo->flags = uport->flags;
693 retinfo->xmit_fifo_size = uport->fifosize;
694 retinfo->baud_base = uport->uartclk / 16;
695 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
696 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
697 ASYNC_CLOSING_WAIT_NONE :
698 jiffies_to_msecs(port->closing_wait) / 10;
699 retinfo->custom_divisor = uport->custom_divisor;
700 retinfo->hub6 = uport->hub6;
701 retinfo->io_type = uport->iotype;
702 retinfo->iomem_reg_shift = uport->regshift;
703 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
704 mutex_unlock(&port->mutex);
705}
706
707static int uart_get_info_user(struct tty_port *port,
708 struct serial_struct __user *retinfo)
709{
710 struct serial_struct tmp;
711
712 uart_get_info(port, &tmp);
713
714 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
715 return -EFAULT;
716 return 0;
717}
718
719static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
720 struct uart_state *state,
721 struct serial_struct *new_info)
722{
723 struct uart_port *uport = state->uart_port;
724 unsigned long new_port;
725 unsigned int change_irq, change_port, closing_wait;
726 unsigned int old_custom_divisor, close_delay;
727 upf_t old_flags, new_flags;
728 int retval = 0;
729
730 new_port = new_info->port;
731 if (HIGH_BITS_OFFSET)
732 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
733
734 new_info->irq = irq_canonicalize(new_info->irq);
735 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
736 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
737 ASYNC_CLOSING_WAIT_NONE :
738 msecs_to_jiffies(new_info->closing_wait * 10);
739
740
741 change_irq = !(uport->flags & UPF_FIXED_PORT)
742 && new_info->irq != uport->irq;
743
744 /*
745 * Since changing the 'type' of the port changes its resource
746 * allocations, we should treat type changes the same as
747 * IO port changes.
748 */
749 change_port = !(uport->flags & UPF_FIXED_PORT)
750 && (new_port != uport->iobase ||
751 (unsigned long)new_info->iomem_base != uport->mapbase ||
752 new_info->hub6 != uport->hub6 ||
753 new_info->io_type != uport->iotype ||
754 new_info->iomem_reg_shift != uport->regshift ||
755 new_info->type != uport->type);
756
757 old_flags = uport->flags;
758 new_flags = new_info->flags;
759 old_custom_divisor = uport->custom_divisor;
760
761 if (!capable(CAP_SYS_ADMIN)) {
762 retval = -EPERM;
763 if (change_irq || change_port ||
764 (new_info->baud_base != uport->uartclk / 16) ||
765 (close_delay != port->close_delay) ||
766 (closing_wait != port->closing_wait) ||
767 (new_info->xmit_fifo_size &&
768 new_info->xmit_fifo_size != uport->fifosize) ||
769 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
770 goto exit;
771 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
772 (new_flags & UPF_USR_MASK));
773 uport->custom_divisor = new_info->custom_divisor;
774 goto check_and_exit;
775 }
776
777 /*
778 * Ask the low level driver to verify the settings.
779 */
780 if (uport->ops->verify_port)
781 retval = uport->ops->verify_port(uport, new_info);
782
783 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
784 (new_info->baud_base < 9600))
785 retval = -EINVAL;
786
787 if (retval)
788 goto exit;
789
790 if (change_port || change_irq) {
791 retval = -EBUSY;
792
793 /*
794 * Make sure that we are the sole user of this port.
795 */
796 if (tty_port_users(port) > 1)
797 goto exit;
798
799 /*
800 * We need to shutdown the serial port at the old
801 * port/type/irq combination.
802 */
803 uart_shutdown(tty, state);
804 }
805
806 if (change_port) {
807 unsigned long old_iobase, old_mapbase;
808 unsigned int old_type, old_iotype, old_hub6, old_shift;
809
810 old_iobase = uport->iobase;
811 old_mapbase = uport->mapbase;
812 old_type = uport->type;
813 old_hub6 = uport->hub6;
814 old_iotype = uport->iotype;
815 old_shift = uport->regshift;
816
817 /*
818 * Free and release old regions
819 */
820 if (old_type != PORT_UNKNOWN)
821 uport->ops->release_port(uport);
822
823 uport->iobase = new_port;
824 uport->type = new_info->type;
825 uport->hub6 = new_info->hub6;
826 uport->iotype = new_info->io_type;
827 uport->regshift = new_info->iomem_reg_shift;
828 uport->mapbase = (unsigned long)new_info->iomem_base;
829
830 /*
831 * Claim and map the new regions
832 */
833 if (uport->type != PORT_UNKNOWN) {
834 retval = uport->ops->request_port(uport);
835 } else {
836 /* Always success - Jean II */
837 retval = 0;
838 }
839
840 /*
841 * If we fail to request resources for the
842 * new port, try to restore the old settings.
843 */
844 if (retval) {
845 uport->iobase = old_iobase;
846 uport->type = old_type;
847 uport->hub6 = old_hub6;
848 uport->iotype = old_iotype;
849 uport->regshift = old_shift;
850 uport->mapbase = old_mapbase;
851
852 if (old_type != PORT_UNKNOWN) {
853 retval = uport->ops->request_port(uport);
854 /*
855 * If we failed to restore the old settings,
856 * we fail like this.
857 */
858 if (retval)
859 uport->type = PORT_UNKNOWN;
860
861 /*
862 * We failed anyway.
863 */
864 retval = -EBUSY;
865 }
866
867 /* Added to return the correct error -Ram Gupta */
868 goto exit;
869 }
870 }
871
872 if (change_irq)
873 uport->irq = new_info->irq;
874 if (!(uport->flags & UPF_FIXED_PORT))
875 uport->uartclk = new_info->baud_base * 16;
876 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
877 (new_flags & UPF_CHANGE_MASK);
878 uport->custom_divisor = new_info->custom_divisor;
879 port->close_delay = close_delay;
880 port->closing_wait = closing_wait;
881 if (new_info->xmit_fifo_size)
882 uport->fifosize = new_info->xmit_fifo_size;
883 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
884
885 check_and_exit:
886 retval = 0;
887 if (uport->type == PORT_UNKNOWN)
888 goto exit;
889 if (port->flags & ASYNC_INITIALIZED) {
890 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
891 old_custom_divisor != uport->custom_divisor) {
892 /*
893 * If they're setting up a custom divisor or speed,
894 * instead of clearing it, then bitch about it. No
895 * need to rate-limit; it's CAP_SYS_ADMIN only.
896 */
897 if (uport->flags & UPF_SPD_MASK) {
898 dev_notice(uport->dev,
899 "%s sets custom speed on %s. This is deprecated.\n",
900 current->comm,
901 tty_name(port->tty));
902 }
903 uart_change_speed(tty, state, NULL);
904 }
905 } else
906 retval = uart_startup(tty, state, 1);
907 exit:
908 return retval;
909}
910
911static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
912 struct serial_struct __user *newinfo)
913{
914 struct serial_struct new_serial;
915 struct tty_port *port = &state->port;
916 int retval;
917
918 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
919 return -EFAULT;
920
921 /*
922 * This semaphore protects port->count. It is also
923 * very useful to prevent opens. Also, take the
924 * port configuration semaphore to make sure that a
925 * module insertion/removal doesn't change anything
926 * under us.
927 */
928 mutex_lock(&port->mutex);
929 retval = uart_set_info(tty, port, state, &new_serial);
930 mutex_unlock(&port->mutex);
931 return retval;
932}
933
934/**
935 * uart_get_lsr_info - get line status register info
936 * @tty: tty associated with the UART
937 * @state: UART being queried
938 * @value: returned modem value
939 *
940 * Note: uart_ioctl protects us against hangups.
941 */
942static int uart_get_lsr_info(struct tty_struct *tty,
943 struct uart_state *state, unsigned int __user *value)
944{
945 struct uart_port *uport = state->uart_port;
946 unsigned int result;
947
948 result = uport->ops->tx_empty(uport);
949
950 /*
951 * If we're about to load something into the transmit
952 * register, we'll pretend the transmitter isn't empty to
953 * avoid a race condition (depending on when the transmit
954 * interrupt happens).
955 */
956 if (uport->x_char ||
957 ((uart_circ_chars_pending(&state->xmit) > 0) &&
958 !uart_tx_stopped(uport)))
959 result &= ~TIOCSER_TEMT;
960
961 return put_user(result, value);
962}
963
964static int uart_tiocmget(struct tty_struct *tty)
965{
966 struct uart_state *state = tty->driver_data;
967 struct tty_port *port = &state->port;
968 struct uart_port *uport = state->uart_port;
969 int result = -EIO;
970
971 mutex_lock(&port->mutex);
972 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
973 result = uport->mctrl;
974 spin_lock_irq(&uport->lock);
975 result |= uport->ops->get_mctrl(uport);
976 spin_unlock_irq(&uport->lock);
977 }
978 mutex_unlock(&port->mutex);
979
980 return result;
981}
982
983static int
984uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
985{
986 struct uart_state *state = tty->driver_data;
987 struct uart_port *uport = state->uart_port;
988 struct tty_port *port = &state->port;
989 int ret = -EIO;
990
991 mutex_lock(&port->mutex);
992 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
993 uart_update_mctrl(uport, set, clear);
994 ret = 0;
995 }
996 mutex_unlock(&port->mutex);
997 return ret;
998}
999
1000static int uart_break_ctl(struct tty_struct *tty, int break_state)
1001{
1002 struct uart_state *state = tty->driver_data;
1003 struct tty_port *port = &state->port;
1004 struct uart_port *uport = state->uart_port;
1005
1006 mutex_lock(&port->mutex);
1007
1008 if (uport->type != PORT_UNKNOWN)
1009 uport->ops->break_ctl(uport, break_state);
1010
1011 mutex_unlock(&port->mutex);
1012 return 0;
1013}
1014
1015static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1016{
1017 struct uart_port *uport = state->uart_port;
1018 struct tty_port *port = &state->port;
1019 int flags, ret;
1020
1021 if (!capable(CAP_SYS_ADMIN))
1022 return -EPERM;
1023
1024 /*
1025 * Take the per-port semaphore. This prevents count from
1026 * changing, and hence any extra opens of the port while
1027 * we're auto-configuring.
1028 */
1029 if (mutex_lock_interruptible(&port->mutex))
1030 return -ERESTARTSYS;
1031
1032 ret = -EBUSY;
1033 if (tty_port_users(port) == 1) {
1034 uart_shutdown(tty, state);
1035
1036 /*
1037 * If we already have a port type configured,
1038 * we must release its resources.
1039 */
1040 if (uport->type != PORT_UNKNOWN)
1041 uport->ops->release_port(uport);
1042
1043 flags = UART_CONFIG_TYPE;
1044 if (uport->flags & UPF_AUTO_IRQ)
1045 flags |= UART_CONFIG_IRQ;
1046
1047 /*
1048 * This will claim the ports resources if
1049 * a port is found.
1050 */
1051 uport->ops->config_port(uport, flags);
1052
1053 ret = uart_startup(tty, state, 1);
1054 }
1055 mutex_unlock(&port->mutex);
1056 return ret;
1057}
1058
1059static void uart_enable_ms(struct uart_port *uport)
1060{
1061 /*
1062 * Force modem status interrupts on
1063 */
1064 if (uport->ops->enable_ms)
1065 uport->ops->enable_ms(uport);
1066}
1067
1068/*
1069 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1070 * - mask passed in arg for lines of interest
1071 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1072 * Caller should use TIOCGICOUNT to see which one it was
1073 *
1074 * FIXME: This wants extracting into a common all driver implementation
1075 * of TIOCMWAIT using tty_port.
1076 */
1077static int
1078uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1079{
1080 struct uart_port *uport = state->uart_port;
1081 struct tty_port *port = &state->port;
1082 DECLARE_WAITQUEUE(wait, current);
1083 struct uart_icount cprev, cnow;
1084 int ret;
1085
1086 /*
1087 * note the counters on entry
1088 */
1089 spin_lock_irq(&uport->lock);
1090 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1091 uart_enable_ms(uport);
1092 spin_unlock_irq(&uport->lock);
1093
1094 add_wait_queue(&port->delta_msr_wait, &wait);
1095 for (;;) {
1096 spin_lock_irq(&uport->lock);
1097 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1098 spin_unlock_irq(&uport->lock);
1099
1100 set_current_state(TASK_INTERRUPTIBLE);
1101
1102 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1103 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1104 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1105 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1106 ret = 0;
1107 break;
1108 }
1109
1110 schedule();
1111
1112 /* see if a signal did it */
1113 if (signal_pending(current)) {
1114 ret = -ERESTARTSYS;
1115 break;
1116 }
1117
1118 cprev = cnow;
1119 }
1120 __set_current_state(TASK_RUNNING);
1121 remove_wait_queue(&port->delta_msr_wait, &wait);
1122
1123 return ret;
1124}
1125
1126/*
1127 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1128 * Return: write counters to the user passed counter struct
1129 * NB: both 1->0 and 0->1 transitions are counted except for
1130 * RI where only 0->1 is counted.
1131 */
1132static int uart_get_icount(struct tty_struct *tty,
1133 struct serial_icounter_struct *icount)
1134{
1135 struct uart_state *state = tty->driver_data;
1136 struct uart_icount cnow;
1137 struct uart_port *uport = state->uart_port;
1138
1139 spin_lock_irq(&uport->lock);
1140 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1141 spin_unlock_irq(&uport->lock);
1142
1143 icount->cts = cnow.cts;
1144 icount->dsr = cnow.dsr;
1145 icount->rng = cnow.rng;
1146 icount->dcd = cnow.dcd;
1147 icount->rx = cnow.rx;
1148 icount->tx = cnow.tx;
1149 icount->frame = cnow.frame;
1150 icount->overrun = cnow.overrun;
1151 icount->parity = cnow.parity;
1152 icount->brk = cnow.brk;
1153 icount->buf_overrun = cnow.buf_overrun;
1154
1155 return 0;
1156}
1157
1158static int uart_get_rs485_config(struct uart_port *port,
1159 struct serial_rs485 __user *rs485)
1160{
1161 unsigned long flags;
1162 struct serial_rs485 aux;
1163
1164 spin_lock_irqsave(&port->lock, flags);
1165 aux = port->rs485;
1166 spin_unlock_irqrestore(&port->lock, flags);
1167
1168 if (copy_to_user(rs485, &aux, sizeof(aux)))
1169 return -EFAULT;
1170
1171 return 0;
1172}
1173
1174static int uart_set_rs485_config(struct uart_port *port,
1175 struct serial_rs485 __user *rs485_user)
1176{
1177 struct serial_rs485 rs485;
1178 int ret;
1179 unsigned long flags;
1180
1181 if (!port->rs485_config)
1182 return -ENOIOCTLCMD;
1183
1184 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1185 return -EFAULT;
1186
1187 spin_lock_irqsave(&port->lock, flags);
1188 ret = port->rs485_config(port, &rs485);
1189 spin_unlock_irqrestore(&port->lock, flags);
1190 if (ret)
1191 return ret;
1192
1193 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1194 return -EFAULT;
1195
1196 return 0;
1197}
1198
1199/*
1200 * Called via sys_ioctl. We can use spin_lock_irq() here.
1201 */
1202static int
1203uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1204 unsigned long arg)
1205{
1206 struct uart_state *state = tty->driver_data;
1207 struct tty_port *port = &state->port;
1208 void __user *uarg = (void __user *)arg;
1209 int ret = -ENOIOCTLCMD;
1210
1211
1212 /*
1213 * These ioctls don't rely on the hardware to be present.
1214 */
1215 switch (cmd) {
1216 case TIOCGSERIAL:
1217 ret = uart_get_info_user(port, uarg);
1218 break;
1219
1220 case TIOCSSERIAL:
1221 down_write(&tty->termios_rwsem);
1222 ret = uart_set_info_user(tty, state, uarg);
1223 up_write(&tty->termios_rwsem);
1224 break;
1225
1226 case TIOCSERCONFIG:
1227 down_write(&tty->termios_rwsem);
1228 ret = uart_do_autoconfig(tty, state);
1229 up_write(&tty->termios_rwsem);
1230 break;
1231
1232 case TIOCSERGWILD: /* obsolete */
1233 case TIOCSERSWILD: /* obsolete */
1234 ret = 0;
1235 break;
1236 }
1237
1238 if (ret != -ENOIOCTLCMD)
1239 goto out;
1240
1241 if (tty->flags & (1 << TTY_IO_ERROR)) {
1242 ret = -EIO;
1243 goto out;
1244 }
1245
1246 /*
1247 * The following should only be used when hardware is present.
1248 */
1249 switch (cmd) {
1250 case TIOCMIWAIT:
1251 ret = uart_wait_modem_status(state, arg);
1252 break;
1253 }
1254
1255 if (ret != -ENOIOCTLCMD)
1256 goto out;
1257
1258 mutex_lock(&port->mutex);
1259
1260 if (tty->flags & (1 << TTY_IO_ERROR)) {
1261 ret = -EIO;
1262 goto out_up;
1263 }
1264
1265 /*
1266 * All these rely on hardware being present and need to be
1267 * protected against the tty being hung up.
1268 */
1269
1270 switch (cmd) {
1271 case TIOCSERGETLSR: /* Get line status register */
1272 ret = uart_get_lsr_info(tty, state, uarg);
1273 break;
1274
1275 case TIOCGRS485:
1276 ret = uart_get_rs485_config(state->uart_port, uarg);
1277 break;
1278
1279 case TIOCSRS485:
1280 ret = uart_set_rs485_config(state->uart_port, uarg);
1281 break;
1282 default: {
1283 struct uart_port *uport = state->uart_port;
1284 if (uport->ops->ioctl)
1285 ret = uport->ops->ioctl(uport, cmd, arg);
1286 break;
1287 }
1288 }
1289out_up:
1290 mutex_unlock(&port->mutex);
1291out:
1292 return ret;
1293}
1294
1295static void uart_set_ldisc(struct tty_struct *tty)
1296{
1297 struct uart_state *state = tty->driver_data;
1298 struct uart_port *uport = state->uart_port;
1299
1300 if (uport->ops->set_ldisc) {
1301 mutex_lock(&state->port.mutex);
1302 uport->ops->set_ldisc(uport, &tty->termios);
1303 mutex_unlock(&state->port.mutex);
1304 }
1305}
1306
1307static void uart_set_termios(struct tty_struct *tty,
1308 struct ktermios *old_termios)
1309{
1310 struct uart_state *state = tty->driver_data;
1311 struct uart_port *uport = state->uart_port;
1312 unsigned int cflag = tty->termios.c_cflag;
1313 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1314 bool sw_changed = false;
1315
1316 /*
1317 * Drivers doing software flow control also need to know
1318 * about changes to these input settings.
1319 */
1320 if (uport->flags & UPF_SOFT_FLOW) {
1321 iflag_mask |= IXANY|IXON|IXOFF;
1322 sw_changed =
1323 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1324 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1325 }
1326
1327 /*
1328 * These are the bits that are used to setup various
1329 * flags in the low level driver. We can ignore the Bfoo
1330 * bits in c_cflag; c_[io]speed will always be set
1331 * appropriately by set_termios() in tty_ioctl.c
1332 */
1333 if ((cflag ^ old_termios->c_cflag) == 0 &&
1334 tty->termios.c_ospeed == old_termios->c_ospeed &&
1335 tty->termios.c_ispeed == old_termios->c_ispeed &&
1336 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1337 !sw_changed) {
1338 return;
1339 }
1340
1341 mutex_lock(&state->port.mutex);
1342 uart_change_speed(tty, state, old_termios);
1343 mutex_unlock(&state->port.mutex);
1344 /* reload cflag from termios; port driver may have overriden flags */
1345 cflag = tty->termios.c_cflag;
1346
1347 /* Handle transition to B0 status */
1348 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1349 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1350 /* Handle transition away from B0 status */
1351 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1352 unsigned int mask = TIOCM_DTR;
1353 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
1354 mask |= TIOCM_RTS;
1355 uart_set_mctrl(uport, mask);
1356 }
1357}
1358
1359/*
1360 * Calls to uart_close() are serialised via the tty_lock in
1361 * drivers/tty/tty_io.c:tty_release()
1362 * drivers/tty/tty_io.c:do_tty_hangup()
1363 * This runs from a workqueue and can sleep for a _short_ time only.
1364 */
1365static void uart_close(struct tty_struct *tty, struct file *filp)
1366{
1367 struct uart_state *state = tty->driver_data;
1368 struct tty_port *port;
1369 struct uart_port *uport;
1370
1371 if (!state) {
1372 struct uart_driver *drv = tty->driver->driver_state;
1373
1374 state = drv->state + tty->index;
1375 port = &state->port;
1376 spin_lock_irq(&port->lock);
1377 --port->count;
1378 spin_unlock_irq(&port->lock);
1379 return;
1380 }
1381
1382 uport = state->uart_port;
1383 port = &state->port;
1384 pr_debug("uart_close(%d) called\n", tty->index);
1385
1386 if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1387 return;
1388
1389 /*
1390 * At this point, we stop accepting input. To do this, we
1391 * disable the receive line status interrupts.
1392 */
1393 if (port->flags & ASYNC_INITIALIZED) {
1394 spin_lock_irq(&uport->lock);
1395 uport->ops->stop_rx(uport);
1396 spin_unlock_irq(&uport->lock);
1397 /*
1398 * Before we drop DTR, make sure the UART transmitter
1399 * has completely drained; this is especially
1400 * important if there is a transmit FIFO!
1401 */
1402 uart_wait_until_sent(tty, uport->timeout);
1403 }
1404
1405 mutex_lock(&port->mutex);
1406 uart_shutdown(tty, state);
1407 tty_port_tty_set(port, NULL);
1408
1409 spin_lock_irq(&port->lock);
1410
1411 if (port->blocked_open) {
1412 spin_unlock_irq(&port->lock);
1413 if (port->close_delay)
1414 msleep_interruptible(jiffies_to_msecs(port->close_delay));
1415 spin_lock_irq(&port->lock);
1416 } else if (!uart_console(uport)) {
1417 spin_unlock_irq(&port->lock);
1418 uart_change_pm(state, UART_PM_STATE_OFF);
1419 spin_lock_irq(&port->lock);
1420 }
1421
1422 /*
1423 * Wake up anyone trying to open this port.
1424 */
1425 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1426 spin_unlock_irq(&port->lock);
1427 wake_up_interruptible(&port->open_wait);
1428
1429 mutex_unlock(&port->mutex);
1430
1431 tty_ldisc_flush(tty);
1432 tty->closing = 0;
1433}
1434
1435static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1436{
1437 struct uart_state *state = tty->driver_data;
1438 struct uart_port *port = state->uart_port;
1439 unsigned long char_time, expire;
1440
1441 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1442 return;
1443
1444 /*
1445 * Set the check interval to be 1/5 of the estimated time to
1446 * send a single character, and make it at least 1. The check
1447 * interval should also be less than the timeout.
1448 *
1449 * Note: we have to use pretty tight timings here to satisfy
1450 * the NIST-PCTS.
1451 */
1452 char_time = (port->timeout - HZ/50) / port->fifosize;
1453 char_time = char_time / 5;
1454 if (char_time == 0)
1455 char_time = 1;
1456 if (timeout && timeout < char_time)
1457 char_time = timeout;
1458
1459 /*
1460 * If the transmitter hasn't cleared in twice the approximate
1461 * amount of time to send the entire FIFO, it probably won't
1462 * ever clear. This assumes the UART isn't doing flow
1463 * control, which is currently the case. Hence, if it ever
1464 * takes longer than port->timeout, this is probably due to a
1465 * UART bug of some kind. So, we clamp the timeout parameter at
1466 * 2*port->timeout.
1467 */
1468 if (timeout == 0 || timeout > 2 * port->timeout)
1469 timeout = 2 * port->timeout;
1470
1471 expire = jiffies + timeout;
1472
1473 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1474 port->line, jiffies, expire);
1475
1476 /*
1477 * Check whether the transmitter is empty every 'char_time'.
1478 * 'timeout' / 'expire' give us the maximum amount of time
1479 * we wait.
1480 */
1481 while (!port->ops->tx_empty(port)) {
1482 msleep_interruptible(jiffies_to_msecs(char_time));
1483 if (signal_pending(current))
1484 break;
1485 if (time_after(jiffies, expire))
1486 break;
1487 }
1488}
1489
1490/*
1491 * Calls to uart_hangup() are serialised by the tty_lock in
1492 * drivers/tty/tty_io.c:do_tty_hangup()
1493 * This runs from a workqueue and can sleep for a _short_ time only.
1494 */
1495static void uart_hangup(struct tty_struct *tty)
1496{
1497 struct uart_state *state = tty->driver_data;
1498 struct tty_port *port = &state->port;
1499 unsigned long flags;
1500
1501 pr_debug("uart_hangup(%d)\n", tty->index);
1502
1503 mutex_lock(&port->mutex);
1504 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1505 uart_flush_buffer(tty);
1506 uart_shutdown(tty, state);
1507 spin_lock_irqsave(&port->lock, flags);
1508 port->count = 0;
1509 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1510 spin_unlock_irqrestore(&port->lock, flags);
1511 tty_port_tty_set(port, NULL);
1512 if (!uart_console(state->uart_port))
1513 uart_change_pm(state, UART_PM_STATE_OFF);
1514 wake_up_interruptible(&port->open_wait);
1515 wake_up_interruptible(&port->delta_msr_wait);
1516 }
1517 mutex_unlock(&port->mutex);
1518}
1519
1520static void uart_port_shutdown(struct tty_port *port)
1521{
1522 struct uart_state *state = container_of(port, struct uart_state, port);
1523 struct uart_port *uport = state->uart_port;
1524
1525 /*
1526 * clear delta_msr_wait queue to avoid mem leaks: we may free
1527 * the irq here so the queue might never be woken up. Note
1528 * that we won't end up waiting on delta_msr_wait again since
1529 * any outstanding file descriptors should be pointing at
1530 * hung_up_tty_fops now.
1531 */
1532 wake_up_interruptible(&port->delta_msr_wait);
1533
1534 /*
1535 * Free the IRQ and disable the port.
1536 */
1537 uport->ops->shutdown(uport);
1538
1539 /*
1540 * Ensure that the IRQ handler isn't running on another CPU.
1541 */
1542 synchronize_irq(uport->irq);
1543}
1544
1545static int uart_carrier_raised(struct tty_port *port)
1546{
1547 struct uart_state *state = container_of(port, struct uart_state, port);
1548 struct uart_port *uport = state->uart_port;
1549 int mctrl;
1550 spin_lock_irq(&uport->lock);
1551 uart_enable_ms(uport);
1552 mctrl = uport->ops->get_mctrl(uport);
1553 spin_unlock_irq(&uport->lock);
1554 if (mctrl & TIOCM_CAR)
1555 return 1;
1556 return 0;
1557}
1558
1559static void uart_dtr_rts(struct tty_port *port, int onoff)
1560{
1561 struct uart_state *state = container_of(port, struct uart_state, port);
1562 struct uart_port *uport = state->uart_port;
1563
1564 if (onoff)
1565 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1566 else
1567 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1568}
1569
1570/*
1571 * Calls to uart_open are serialised by the tty_lock in
1572 * drivers/tty/tty_io.c:tty_open()
1573 * Note that if this fails, then uart_close() _will_ be called.
1574 *
1575 * In time, we want to scrap the "opening nonpresent ports"
1576 * behaviour and implement an alternative way for setserial
1577 * to set base addresses/ports/types. This will allow us to
1578 * get rid of a certain amount of extra tests.
1579 */
1580static int uart_open(struct tty_struct *tty, struct file *filp)
1581{
1582 struct uart_driver *drv = tty->driver->driver_state;
1583 int retval, line = tty->index;
1584 struct uart_state *state = drv->state + line;
1585 struct tty_port *port = &state->port;
1586
1587 pr_debug("uart_open(%d) called\n", line);
1588
1589 spin_lock_irq(&port->lock);
1590 ++port->count;
1591 spin_unlock_irq(&port->lock);
1592
1593 /*
1594 * We take the semaphore here to guarantee that we won't be re-entered
1595 * while allocating the state structure, or while we request any IRQs
1596 * that the driver may need. This also has the nice side-effect that
1597 * it delays the action of uart_hangup, so we can guarantee that
1598 * state->port.tty will always contain something reasonable.
1599 */
1600 if (mutex_lock_interruptible(&port->mutex)) {
1601 retval = -ERESTARTSYS;
1602 goto end;
1603 }
1604
1605 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1606 retval = -ENXIO;
1607 goto err_unlock;
1608 }
1609
1610 tty->driver_data = state;
1611 state->uart_port->state = state;
1612 state->port.low_latency =
1613 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1614 tty_port_tty_set(port, tty);
1615
1616 /*
1617 * Start up the serial port.
1618 */
1619 retval = uart_startup(tty, state, 0);
1620
1621 /*
1622 * If we succeeded, wait until the port is ready.
1623 */
1624err_unlock:
1625 mutex_unlock(&port->mutex);
1626 if (retval == 0)
1627 retval = tty_port_block_til_ready(port, tty, filp);
1628end:
1629 return retval;
1630}
1631
1632static const char *uart_type(struct uart_port *port)
1633{
1634 const char *str = NULL;
1635
1636 if (port->ops->type)
1637 str = port->ops->type(port);
1638
1639 if (!str)
1640 str = "unknown";
1641
1642 return str;
1643}
1644
1645#ifdef CONFIG_PROC_FS
1646
1647static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1648{
1649 struct uart_state *state = drv->state + i;
1650 struct tty_port *port = &state->port;
1651 enum uart_pm_state pm_state;
1652 struct uart_port *uport = state->uart_port;
1653 char stat_buf[32];
1654 unsigned int status;
1655 int mmio;
1656
1657 if (!uport)
1658 return;
1659
1660 mmio = uport->iotype >= UPIO_MEM;
1661 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1662 uport->line, uart_type(uport),
1663 mmio ? "mmio:0x" : "port:",
1664 mmio ? (unsigned long long)uport->mapbase
1665 : (unsigned long long)uport->iobase,
1666 uport->irq);
1667
1668 if (uport->type == PORT_UNKNOWN) {
1669 seq_putc(m, '\n');
1670 return;
1671 }
1672
1673 if (capable(CAP_SYS_ADMIN)) {
1674 mutex_lock(&port->mutex);
1675 pm_state = state->pm_state;
1676 if (pm_state != UART_PM_STATE_ON)
1677 uart_change_pm(state, UART_PM_STATE_ON);
1678 spin_lock_irq(&uport->lock);
1679 status = uport->ops->get_mctrl(uport);
1680 spin_unlock_irq(&uport->lock);
1681 if (pm_state != UART_PM_STATE_ON)
1682 uart_change_pm(state, pm_state);
1683 mutex_unlock(&port->mutex);
1684
1685 seq_printf(m, " tx:%d rx:%d",
1686 uport->icount.tx, uport->icount.rx);
1687 if (uport->icount.frame)
1688 seq_printf(m, " fe:%d", uport->icount.frame);
1689 if (uport->icount.parity)
1690 seq_printf(m, " pe:%d", uport->icount.parity);
1691 if (uport->icount.brk)
1692 seq_printf(m, " brk:%d", uport->icount.brk);
1693 if (uport->icount.overrun)
1694 seq_printf(m, " oe:%d", uport->icount.overrun);
1695
1696#define INFOBIT(bit, str) \
1697 if (uport->mctrl & (bit)) \
1698 strncat(stat_buf, (str), sizeof(stat_buf) - \
1699 strlen(stat_buf) - 2)
1700#define STATBIT(bit, str) \
1701 if (status & (bit)) \
1702 strncat(stat_buf, (str), sizeof(stat_buf) - \
1703 strlen(stat_buf) - 2)
1704
1705 stat_buf[0] = '\0';
1706 stat_buf[1] = '\0';
1707 INFOBIT(TIOCM_RTS, "|RTS");
1708 STATBIT(TIOCM_CTS, "|CTS");
1709 INFOBIT(TIOCM_DTR, "|DTR");
1710 STATBIT(TIOCM_DSR, "|DSR");
1711 STATBIT(TIOCM_CAR, "|CD");
1712 STATBIT(TIOCM_RNG, "|RI");
1713 if (stat_buf[0])
1714 stat_buf[0] = ' ';
1715
1716 seq_puts(m, stat_buf);
1717 }
1718 seq_putc(m, '\n');
1719#undef STATBIT
1720#undef INFOBIT
1721}
1722
1723static int uart_proc_show(struct seq_file *m, void *v)
1724{
1725 struct tty_driver *ttydrv = m->private;
1726 struct uart_driver *drv = ttydrv->driver_state;
1727 int i;
1728
1729 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
1730 for (i = 0; i < drv->nr; i++)
1731 uart_line_info(m, drv, i);
1732 return 0;
1733}
1734
1735static int uart_proc_open(struct inode *inode, struct file *file)
1736{
1737 return single_open(file, uart_proc_show, PDE_DATA(inode));
1738}
1739
1740static const struct file_operations uart_proc_fops = {
1741 .owner = THIS_MODULE,
1742 .open = uart_proc_open,
1743 .read = seq_read,
1744 .llseek = seq_lseek,
1745 .release = single_release,
1746};
1747#endif
1748
1749#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1750/**
1751 * uart_console_write - write a console message to a serial port
1752 * @port: the port to write the message
1753 * @s: array of characters
1754 * @count: number of characters in string to write
1755 * @putchar: function to write character to port
1756 */
1757void uart_console_write(struct uart_port *port, const char *s,
1758 unsigned int count,
1759 void (*putchar)(struct uart_port *, int))
1760{
1761 unsigned int i;
1762
1763 for (i = 0; i < count; i++, s++) {
1764 if (*s == '\n')
1765 putchar(port, '\r');
1766 putchar(port, *s);
1767 }
1768}
1769EXPORT_SYMBOL_GPL(uart_console_write);
1770
1771/*
1772 * Check whether an invalid uart number has been specified, and
1773 * if so, search for the first available port that does have
1774 * console support.
1775 */
1776struct uart_port * __init
1777uart_get_console(struct uart_port *ports, int nr, struct console *co)
1778{
1779 int idx = co->index;
1780
1781 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1782 ports[idx].membase == NULL))
1783 for (idx = 0; idx < nr; idx++)
1784 if (ports[idx].iobase != 0 ||
1785 ports[idx].membase != NULL)
1786 break;
1787
1788 co->index = idx;
1789
1790 return ports + idx;
1791}
1792
1793/**
1794 * uart_parse_earlycon - Parse earlycon options
1795 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1796 * @iotype: ptr for decoded iotype (out)
1797 * @addr: ptr for decoded mapbase/iobase (out)
1798 * @options: ptr for <options> field; NULL if not present (out)
1799 *
1800 * Decodes earlycon kernel command line parameters of the form
1801 * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1802 * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1803 *
1804 * The optional form
1805 * earlycon=<name>,0x<addr>,<options>
1806 * console=<name>,0x<addr>,<options>
1807 * is also accepted; the returned @iotype will be UPIO_MEM.
1808 *
1809 * Returns 0 on success or -EINVAL on failure
1810 */
1811int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
1812 char **options)
1813{
1814 if (strncmp(p, "mmio,", 5) == 0) {
1815 *iotype = UPIO_MEM;
1816 p += 5;
1817 } else if (strncmp(p, "mmio16,", 7) == 0) {
1818 *iotype = UPIO_MEM16;
1819 p += 7;
1820 } else if (strncmp(p, "mmio32,", 7) == 0) {
1821 *iotype = UPIO_MEM32;
1822 p += 7;
1823 } else if (strncmp(p, "mmio32be,", 9) == 0) {
1824 *iotype = UPIO_MEM32BE;
1825 p += 9;
1826 } else if (strncmp(p, "mmio32native,", 13) == 0) {
1827 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
1828 UPIO_MEM32BE : UPIO_MEM32;
1829 p += 13;
1830 } else if (strncmp(p, "io,", 3) == 0) {
1831 *iotype = UPIO_PORT;
1832 p += 3;
1833 } else if (strncmp(p, "0x", 2) == 0) {
1834 *iotype = UPIO_MEM;
1835 } else {
1836 return -EINVAL;
1837 }
1838
1839 *addr = simple_strtoul(p, NULL, 0);
1840 p = strchr(p, ',');
1841 if (p)
1842 p++;
1843
1844 *options = p;
1845 return 0;
1846}
1847EXPORT_SYMBOL_GPL(uart_parse_earlycon);
1848
1849/**
1850 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1851 * @options: pointer to option string
1852 * @baud: pointer to an 'int' variable for the baud rate.
1853 * @parity: pointer to an 'int' variable for the parity.
1854 * @bits: pointer to an 'int' variable for the number of data bits.
1855 * @flow: pointer to an 'int' variable for the flow control character.
1856 *
1857 * uart_parse_options decodes a string containing the serial console
1858 * options. The format of the string is <baud><parity><bits><flow>,
1859 * eg: 115200n8r
1860 */
1861void
1862uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1863{
1864 char *s = options;
1865
1866 *baud = simple_strtoul(s, NULL, 10);
1867 while (*s >= '0' && *s <= '9')
1868 s++;
1869 if (*s)
1870 *parity = *s++;
1871 if (*s)
1872 *bits = *s++ - '0';
1873 if (*s)
1874 *flow = *s;
1875}
1876EXPORT_SYMBOL_GPL(uart_parse_options);
1877
1878/**
1879 * uart_set_options - setup the serial console parameters
1880 * @port: pointer to the serial ports uart_port structure
1881 * @co: console pointer
1882 * @baud: baud rate
1883 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1884 * @bits: number of data bits
1885 * @flow: flow control character - 'r' (rts)
1886 */
1887int
1888uart_set_options(struct uart_port *port, struct console *co,
1889 int baud, int parity, int bits, int flow)
1890{
1891 struct ktermios termios;
1892 static struct ktermios dummy;
1893
1894 /*
1895 * Ensure that the serial console lock is initialised
1896 * early.
1897 * If this port is a console, then the spinlock is already
1898 * initialised.
1899 */
1900 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1901 spin_lock_init(&port->lock);
1902 lockdep_set_class(&port->lock, &port_lock_key);
1903 }
1904
1905 memset(&termios, 0, sizeof(struct ktermios));
1906
1907 termios.c_cflag |= CREAD | HUPCL | CLOCAL;
1908 tty_termios_encode_baud_rate(&termios, baud, baud);
1909
1910 if (bits == 7)
1911 termios.c_cflag |= CS7;
1912 else
1913 termios.c_cflag |= CS8;
1914
1915 switch (parity) {
1916 case 'o': case 'O':
1917 termios.c_cflag |= PARODD;
1918 /*fall through*/
1919 case 'e': case 'E':
1920 termios.c_cflag |= PARENB;
1921 break;
1922 }
1923
1924 if (flow == 'r')
1925 termios.c_cflag |= CRTSCTS;
1926
1927 /*
1928 * some uarts on other side don't support no flow control.
1929 * So we set * DTR in host uart to make them happy
1930 */
1931 port->mctrl |= TIOCM_DTR;
1932
1933 port->ops->set_termios(port, &termios, &dummy);
1934 /*
1935 * Allow the setting of the UART parameters with a NULL console
1936 * too:
1937 */
1938 if (co)
1939 co->cflag = termios.c_cflag;
1940
1941 return 0;
1942}
1943EXPORT_SYMBOL_GPL(uart_set_options);
1944#endif /* CONFIG_SERIAL_CORE_CONSOLE */
1945
1946/**
1947 * uart_change_pm - set power state of the port
1948 *
1949 * @state: port descriptor
1950 * @pm_state: new state
1951 *
1952 * Locking: port->mutex has to be held
1953 */
1954static void uart_change_pm(struct uart_state *state,
1955 enum uart_pm_state pm_state)
1956{
1957 struct uart_port *port = state->uart_port;
1958
1959 if (state->pm_state != pm_state) {
1960 if (port->ops->pm)
1961 port->ops->pm(port, pm_state, state->pm_state);
1962 state->pm_state = pm_state;
1963 }
1964}
1965
1966struct uart_match {
1967 struct uart_port *port;
1968 struct uart_driver *driver;
1969};
1970
1971static int serial_match_port(struct device *dev, void *data)
1972{
1973 struct uart_match *match = data;
1974 struct tty_driver *tty_drv = match->driver->tty_driver;
1975 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1976 match->port->line;
1977
1978 return dev->devt == devt; /* Actually, only one tty per port */
1979}
1980
1981int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1982{
1983 struct uart_state *state = drv->state + uport->line;
1984 struct tty_port *port = &state->port;
1985 struct device *tty_dev;
1986 struct uart_match match = {uport, drv};
1987
1988 mutex_lock(&port->mutex);
1989
1990 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1991 if (device_may_wakeup(tty_dev)) {
1992 if (!enable_irq_wake(uport->irq))
1993 uport->irq_wake = 1;
1994 put_device(tty_dev);
1995 mutex_unlock(&port->mutex);
1996 return 0;
1997 }
1998 put_device(tty_dev);
1999
2000 /* Nothing to do if the console is not suspending */
2001 if (!console_suspend_enabled && uart_console(uport))
2002 goto unlock;
2003
2004 uport->suspended = 1;
2005
2006 if (port->flags & ASYNC_INITIALIZED) {
2007 const struct uart_ops *ops = uport->ops;
2008 int tries;
2009
2010 set_bit(ASYNCB_SUSPENDED, &port->flags);
2011 clear_bit(ASYNCB_INITIALIZED, &port->flags);
2012
2013 spin_lock_irq(&uport->lock);
2014 ops->stop_tx(uport);
2015 ops->set_mctrl(uport, 0);
2016 ops->stop_rx(uport);
2017 spin_unlock_irq(&uport->lock);
2018
2019 /*
2020 * Wait for the transmitter to empty.
2021 */
2022 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2023 msleep(10);
2024 if (!tries)
2025 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
2026 drv->dev_name,
2027 drv->tty_driver->name_base + uport->line);
2028
2029 ops->shutdown(uport);
2030 }
2031
2032 /*
2033 * Disable the console device before suspending.
2034 */
2035 if (uart_console(uport))
2036 console_stop(uport->cons);
2037
2038 uart_change_pm(state, UART_PM_STATE_OFF);
2039unlock:
2040 mutex_unlock(&port->mutex);
2041
2042 return 0;
2043}
2044
2045int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2046{
2047 struct uart_state *state = drv->state + uport->line;
2048 struct tty_port *port = &state->port;
2049 struct device *tty_dev;
2050 struct uart_match match = {uport, drv};
2051 struct ktermios termios;
2052
2053 mutex_lock(&port->mutex);
2054
2055 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2056 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2057 if (uport->irq_wake) {
2058 disable_irq_wake(uport->irq);
2059 uport->irq_wake = 0;
2060 }
2061 put_device(tty_dev);
2062 mutex_unlock(&port->mutex);
2063 return 0;
2064 }
2065 put_device(tty_dev);
2066 uport->suspended = 0;
2067
2068 /*
2069 * Re-enable the console device after suspending.
2070 */
2071 if (uart_console(uport)) {
2072 /*
2073 * First try to use the console cflag setting.
2074 */
2075 memset(&termios, 0, sizeof(struct ktermios));
2076 termios.c_cflag = uport->cons->cflag;
2077
2078 /*
2079 * If that's unset, use the tty termios setting.
2080 */
2081 if (port->tty && termios.c_cflag == 0)
2082 termios = port->tty->termios;
2083
2084 if (console_suspend_enabled)
2085 uart_change_pm(state, UART_PM_STATE_ON);
2086 uport->ops->set_termios(uport, &termios, NULL);
2087 if (console_suspend_enabled)
2088 console_start(uport->cons);
2089 }
2090
2091 if (port->flags & ASYNC_SUSPENDED) {
2092 const struct uart_ops *ops = uport->ops;
2093 int ret;
2094
2095 uart_change_pm(state, UART_PM_STATE_ON);
2096 spin_lock_irq(&uport->lock);
2097 ops->set_mctrl(uport, 0);
2098 spin_unlock_irq(&uport->lock);
2099 if (console_suspend_enabled || !uart_console(uport)) {
2100 /* Protected by port mutex for now */
2101 struct tty_struct *tty = port->tty;
2102 ret = ops->startup(uport);
2103 if (ret == 0) {
2104 if (tty)
2105 uart_change_speed(tty, state, NULL);
2106 spin_lock_irq(&uport->lock);
2107 ops->set_mctrl(uport, uport->mctrl);
2108 ops->start_tx(uport);
2109 spin_unlock_irq(&uport->lock);
2110 set_bit(ASYNCB_INITIALIZED, &port->flags);
2111 } else {
2112 /*
2113 * Failed to resume - maybe hardware went away?
2114 * Clear the "initialized" flag so we won't try
2115 * to call the low level drivers shutdown method.
2116 */
2117 uart_shutdown(tty, state);
2118 }
2119 }
2120
2121 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2122 }
2123
2124 mutex_unlock(&port->mutex);
2125
2126 return 0;
2127}
2128
2129static inline void
2130uart_report_port(struct uart_driver *drv, struct uart_port *port)
2131{
2132 char address[64];
2133
2134 switch (port->iotype) {
2135 case UPIO_PORT:
2136 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2137 break;
2138 case UPIO_HUB6:
2139 snprintf(address, sizeof(address),
2140 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2141 break;
2142 case UPIO_MEM:
2143 case UPIO_MEM16:
2144 case UPIO_MEM32:
2145 case UPIO_MEM32BE:
2146 case UPIO_AU:
2147 case UPIO_TSI:
2148 snprintf(address, sizeof(address),
2149 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2150 break;
2151 default:
2152 strlcpy(address, "*unknown*", sizeof(address));
2153 break;
2154 }
2155
2156 printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2157 port->dev ? dev_name(port->dev) : "",
2158 port->dev ? ": " : "",
2159 drv->dev_name,
2160 drv->tty_driver->name_base + port->line,
2161 address, port->irq, port->uartclk / 16, uart_type(port));
2162}
2163
2164static void
2165uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2166 struct uart_port *port)
2167{
2168 unsigned int flags;
2169
2170 /*
2171 * If there isn't a port here, don't do anything further.
2172 */
2173 if (!port->iobase && !port->mapbase && !port->membase)
2174 return;
2175
2176 /*
2177 * Now do the auto configuration stuff. Note that config_port
2178 * is expected to claim the resources and map the port for us.
2179 */
2180 flags = 0;
2181 if (port->flags & UPF_AUTO_IRQ)
2182 flags |= UART_CONFIG_IRQ;
2183 if (port->flags & UPF_BOOT_AUTOCONF) {
2184 if (!(port->flags & UPF_FIXED_TYPE)) {
2185 port->type = PORT_UNKNOWN;
2186 flags |= UART_CONFIG_TYPE;
2187 }
2188 port->ops->config_port(port, flags);
2189 }
2190
2191 if (port->type != PORT_UNKNOWN) {
2192 unsigned long flags;
2193
2194 uart_report_port(drv, port);
2195
2196 /* Power up port for set_mctrl() */
2197 uart_change_pm(state, UART_PM_STATE_ON);
2198
2199 /*
2200 * Ensure that the modem control lines are de-activated.
2201 * keep the DTR setting that is set in uart_set_options()
2202 * We probably don't need a spinlock around this, but
2203 */
2204 spin_lock_irqsave(&port->lock, flags);
2205 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2206 spin_unlock_irqrestore(&port->lock, flags);
2207
2208 /*
2209 * If this driver supports console, and it hasn't been
2210 * successfully registered yet, try to re-register it.
2211 * It may be that the port was not available.
2212 */
2213 if (port->cons && !(port->cons->flags & CON_ENABLED))
2214 register_console(port->cons);
2215
2216 /*
2217 * Power down all ports by default, except the
2218 * console if we have one.
2219 */
2220 if (!uart_console(port))
2221 uart_change_pm(state, UART_PM_STATE_OFF);
2222 }
2223}
2224
2225#ifdef CONFIG_CONSOLE_POLL
2226
2227static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2228{
2229 struct uart_driver *drv = driver->driver_state;
2230 struct uart_state *state = drv->state + line;
2231 struct uart_port *port;
2232 int baud = 9600;
2233 int bits = 8;
2234 int parity = 'n';
2235 int flow = 'n';
2236 int ret;
2237
2238 if (!state || !state->uart_port)
2239 return -1;
2240
2241 port = state->uart_port;
2242 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2243 return -1;
2244
2245 if (port->ops->poll_init) {
2246 struct tty_port *tport = &state->port;
2247
2248 ret = 0;
2249 mutex_lock(&tport->mutex);
2250 /*
2251 * We don't set ASYNCB_INITIALIZED as we only initialized the
2252 * hw, e.g. state->xmit is still uninitialized.
2253 */
2254 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2255 ret = port->ops->poll_init(port);
2256 mutex_unlock(&tport->mutex);
2257 if (ret)
2258 return ret;
2259 }
2260
2261 if (options) {
2262 uart_parse_options(options, &baud, &parity, &bits, &flow);
2263 return uart_set_options(port, NULL, baud, parity, bits, flow);
2264 }
2265
2266 return 0;
2267}
2268
2269static int uart_poll_get_char(struct tty_driver *driver, int line)
2270{
2271 struct uart_driver *drv = driver->driver_state;
2272 struct uart_state *state = drv->state + line;
2273 struct uart_port *port;
2274
2275 if (!state || !state->uart_port)
2276 return -1;
2277
2278 port = state->uart_port;
2279 return port->ops->poll_get_char(port);
2280}
2281
2282static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2283{
2284 struct uart_driver *drv = driver->driver_state;
2285 struct uart_state *state = drv->state + line;
2286 struct uart_port *port;
2287
2288 if (!state || !state->uart_port)
2289 return;
2290
2291 port = state->uart_port;
2292
2293 if (ch == '\n')
2294 port->ops->poll_put_char(port, '\r');
2295 port->ops->poll_put_char(port, ch);
2296}
2297#endif
2298
2299static const struct tty_operations uart_ops = {
2300 .open = uart_open,
2301 .close = uart_close,
2302 .write = uart_write,
2303 .put_char = uart_put_char,
2304 .flush_chars = uart_flush_chars,
2305 .write_room = uart_write_room,
2306 .chars_in_buffer= uart_chars_in_buffer,
2307 .flush_buffer = uart_flush_buffer,
2308 .ioctl = uart_ioctl,
2309 .throttle = uart_throttle,
2310 .unthrottle = uart_unthrottle,
2311 .send_xchar = uart_send_xchar,
2312 .set_termios = uart_set_termios,
2313 .set_ldisc = uart_set_ldisc,
2314 .stop = uart_stop,
2315 .start = uart_start,
2316 .hangup = uart_hangup,
2317 .break_ctl = uart_break_ctl,
2318 .wait_until_sent= uart_wait_until_sent,
2319#ifdef CONFIG_PROC_FS
2320 .proc_fops = &uart_proc_fops,
2321#endif
2322 .tiocmget = uart_tiocmget,
2323 .tiocmset = uart_tiocmset,
2324 .get_icount = uart_get_icount,
2325#ifdef CONFIG_CONSOLE_POLL
2326 .poll_init = uart_poll_init,
2327 .poll_get_char = uart_poll_get_char,
2328 .poll_put_char = uart_poll_put_char,
2329#endif
2330};
2331
2332static const struct tty_port_operations uart_port_ops = {
2333 .carrier_raised = uart_carrier_raised,
2334 .dtr_rts = uart_dtr_rts,
2335};
2336
2337/**
2338 * uart_register_driver - register a driver with the uart core layer
2339 * @drv: low level driver structure
2340 *
2341 * Register a uart driver with the core driver. We in turn register
2342 * with the tty layer, and initialise the core driver per-port state.
2343 *
2344 * We have a proc file in /proc/tty/driver which is named after the
2345 * normal driver.
2346 *
2347 * drv->port should be NULL, and the per-port structures should be
2348 * registered using uart_add_one_port after this call has succeeded.
2349 */
2350int uart_register_driver(struct uart_driver *drv)
2351{
2352 struct tty_driver *normal;
2353 int i, retval;
2354
2355 BUG_ON(drv->state);
2356
2357 /*
2358 * Maybe we should be using a slab cache for this, especially if
2359 * we have a large number of ports to handle.
2360 */
2361 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2362 if (!drv->state)
2363 goto out;
2364
2365 normal = alloc_tty_driver(drv->nr);
2366 if (!normal)
2367 goto out_kfree;
2368
2369 drv->tty_driver = normal;
2370
2371 normal->driver_name = drv->driver_name;
2372 normal->name = drv->dev_name;
2373 normal->major = drv->major;
2374 normal->minor_start = drv->minor;
2375 normal->type = TTY_DRIVER_TYPE_SERIAL;
2376 normal->subtype = SERIAL_TYPE_NORMAL;
2377 normal->init_termios = tty_std_termios;
2378 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2379 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2380 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2381 normal->driver_state = drv;
2382 tty_set_operations(normal, &uart_ops);
2383
2384 /*
2385 * Initialise the UART state(s).
2386 */
2387 for (i = 0; i < drv->nr; i++) {
2388 struct uart_state *state = drv->state + i;
2389 struct tty_port *port = &state->port;
2390
2391 tty_port_init(port);
2392 port->ops = &uart_port_ops;
2393 }
2394
2395 retval = tty_register_driver(normal);
2396 if (retval >= 0)
2397 return retval;
2398
2399 for (i = 0; i < drv->nr; i++)
2400 tty_port_destroy(&drv->state[i].port);
2401 put_tty_driver(normal);
2402out_kfree:
2403 kfree(drv->state);
2404out:
2405 return -ENOMEM;
2406}
2407
2408/**
2409 * uart_unregister_driver - remove a driver from the uart core layer
2410 * @drv: low level driver structure
2411 *
2412 * Remove all references to a driver from the core driver. The low
2413 * level driver must have removed all its ports via the
2414 * uart_remove_one_port() if it registered them with uart_add_one_port().
2415 * (ie, drv->port == NULL)
2416 */
2417void uart_unregister_driver(struct uart_driver *drv)
2418{
2419 struct tty_driver *p = drv->tty_driver;
2420 unsigned int i;
2421
2422 tty_unregister_driver(p);
2423 put_tty_driver(p);
2424 for (i = 0; i < drv->nr; i++)
2425 tty_port_destroy(&drv->state[i].port);
2426 kfree(drv->state);
2427 drv->state = NULL;
2428 drv->tty_driver = NULL;
2429}
2430
2431struct tty_driver *uart_console_device(struct console *co, int *index)
2432{
2433 struct uart_driver *p = co->data;
2434 *index = co->index;
2435 return p->tty_driver;
2436}
2437
2438static ssize_t uart_get_attr_uartclk(struct device *dev,
2439 struct device_attribute *attr, char *buf)
2440{
2441 struct serial_struct tmp;
2442 struct tty_port *port = dev_get_drvdata(dev);
2443
2444 uart_get_info(port, &tmp);
2445 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2446}
2447
2448static ssize_t uart_get_attr_type(struct device *dev,
2449 struct device_attribute *attr, char *buf)
2450{
2451 struct serial_struct tmp;
2452 struct tty_port *port = dev_get_drvdata(dev);
2453
2454 uart_get_info(port, &tmp);
2455 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2456}
2457static ssize_t uart_get_attr_line(struct device *dev,
2458 struct device_attribute *attr, char *buf)
2459{
2460 struct serial_struct tmp;
2461 struct tty_port *port = dev_get_drvdata(dev);
2462
2463 uart_get_info(port, &tmp);
2464 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2465}
2466
2467static ssize_t uart_get_attr_port(struct device *dev,
2468 struct device_attribute *attr, char *buf)
2469{
2470 struct serial_struct tmp;
2471 struct tty_port *port = dev_get_drvdata(dev);
2472 unsigned long ioaddr;
2473
2474 uart_get_info(port, &tmp);
2475 ioaddr = tmp.port;
2476 if (HIGH_BITS_OFFSET)
2477 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2478 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2479}
2480
2481static ssize_t uart_get_attr_irq(struct device *dev,
2482 struct device_attribute *attr, char *buf)
2483{
2484 struct serial_struct tmp;
2485 struct tty_port *port = dev_get_drvdata(dev);
2486
2487 uart_get_info(port, &tmp);
2488 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2489}
2490
2491static ssize_t uart_get_attr_flags(struct device *dev,
2492 struct device_attribute *attr, char *buf)
2493{
2494 struct serial_struct tmp;
2495 struct tty_port *port = dev_get_drvdata(dev);
2496
2497 uart_get_info(port, &tmp);
2498 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2499}
2500
2501static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2502 struct device_attribute *attr, char *buf)
2503{
2504 struct serial_struct tmp;
2505 struct tty_port *port = dev_get_drvdata(dev);
2506
2507 uart_get_info(port, &tmp);
2508 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2509}
2510
2511
2512static ssize_t uart_get_attr_close_delay(struct device *dev,
2513 struct device_attribute *attr, char *buf)
2514{
2515 struct serial_struct tmp;
2516 struct tty_port *port = dev_get_drvdata(dev);
2517
2518 uart_get_info(port, &tmp);
2519 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2520}
2521
2522
2523static ssize_t uart_get_attr_closing_wait(struct device *dev,
2524 struct device_attribute *attr, char *buf)
2525{
2526 struct serial_struct tmp;
2527 struct tty_port *port = dev_get_drvdata(dev);
2528
2529 uart_get_info(port, &tmp);
2530 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2531}
2532
2533static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2534 struct device_attribute *attr, char *buf)
2535{
2536 struct serial_struct tmp;
2537 struct tty_port *port = dev_get_drvdata(dev);
2538
2539 uart_get_info(port, &tmp);
2540 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2541}
2542
2543static ssize_t uart_get_attr_io_type(struct device *dev,
2544 struct device_attribute *attr, char *buf)
2545{
2546 struct serial_struct tmp;
2547 struct tty_port *port = dev_get_drvdata(dev);
2548
2549 uart_get_info(port, &tmp);
2550 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2551}
2552
2553static ssize_t uart_get_attr_iomem_base(struct device *dev,
2554 struct device_attribute *attr, char *buf)
2555{
2556 struct serial_struct tmp;
2557 struct tty_port *port = dev_get_drvdata(dev);
2558
2559 uart_get_info(port, &tmp);
2560 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2561}
2562
2563static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2564 struct device_attribute *attr, char *buf)
2565{
2566 struct serial_struct tmp;
2567 struct tty_port *port = dev_get_drvdata(dev);
2568
2569 uart_get_info(port, &tmp);
2570 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2571}
2572
2573static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2574static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2575static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2576static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2577static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2578static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2579static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2580static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2581static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2582static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2583static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2584static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2585static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2586
2587static struct attribute *tty_dev_attrs[] = {
2588 &dev_attr_type.attr,
2589 &dev_attr_line.attr,
2590 &dev_attr_port.attr,
2591 &dev_attr_irq.attr,
2592 &dev_attr_flags.attr,
2593 &dev_attr_xmit_fifo_size.attr,
2594 &dev_attr_uartclk.attr,
2595 &dev_attr_close_delay.attr,
2596 &dev_attr_closing_wait.attr,
2597 &dev_attr_custom_divisor.attr,
2598 &dev_attr_io_type.attr,
2599 &dev_attr_iomem_base.attr,
2600 &dev_attr_iomem_reg_shift.attr,
2601 NULL,
2602 };
2603
2604static const struct attribute_group tty_dev_attr_group = {
2605 .attrs = tty_dev_attrs,
2606 };
2607
2608/**
2609 * uart_add_one_port - attach a driver-defined port structure
2610 * @drv: pointer to the uart low level driver structure for this port
2611 * @uport: uart port structure to use for this port.
2612 *
2613 * This allows the driver to register its own uart_port structure
2614 * with the core driver. The main purpose is to allow the low
2615 * level uart drivers to expand uart_port, rather than having yet
2616 * more levels of structures.
2617 */
2618int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2619{
2620 struct uart_state *state;
2621 struct tty_port *port;
2622 int ret = 0;
2623 struct device *tty_dev;
2624 int num_groups;
2625
2626 BUG_ON(in_interrupt());
2627
2628 if (uport->line >= drv->nr)
2629 return -EINVAL;
2630
2631 state = drv->state + uport->line;
2632 port = &state->port;
2633
2634 mutex_lock(&port_mutex);
2635 mutex_lock(&port->mutex);
2636 if (state->uart_port) {
2637 ret = -EINVAL;
2638 goto out;
2639 }
2640
2641 /* Link the port to the driver state table and vice versa */
2642 state->uart_port = uport;
2643 uport->state = state;
2644
2645 state->pm_state = UART_PM_STATE_UNDEFINED;
2646 uport->cons = drv->cons;
2647 uport->minor = drv->tty_driver->minor_start + uport->line;
2648
2649 /*
2650 * If this port is a console, then the spinlock is already
2651 * initialised.
2652 */
2653 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2654 spin_lock_init(&uport->lock);
2655 lockdep_set_class(&uport->lock, &port_lock_key);
2656 }
2657 if (uport->cons && uport->dev)
2658 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2659
2660 uart_configure_port(drv, state, uport);
2661
2662 num_groups = 2;
2663 if (uport->attr_group)
2664 num_groups++;
2665
2666 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2667 GFP_KERNEL);
2668 if (!uport->tty_groups) {
2669 ret = -ENOMEM;
2670 goto out;
2671 }
2672 uport->tty_groups[0] = &tty_dev_attr_group;
2673 if (uport->attr_group)
2674 uport->tty_groups[1] = uport->attr_group;
2675
2676 /*
2677 * Register the port whether it's detected or not. This allows
2678 * setserial to be used to alter this port's parameters.
2679 */
2680 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2681 uport->line, uport->dev, port, uport->tty_groups);
2682 if (likely(!IS_ERR(tty_dev))) {
2683 device_set_wakeup_capable(tty_dev, 1);
2684 } else {
2685 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2686 uport->line);
2687 }
2688
2689 /*
2690 * Ensure UPF_DEAD is not set.
2691 */
2692 uport->flags &= ~UPF_DEAD;
2693
2694 out:
2695 mutex_unlock(&port->mutex);
2696 mutex_unlock(&port_mutex);
2697
2698 return ret;
2699}
2700
2701/**
2702 * uart_remove_one_port - detach a driver defined port structure
2703 * @drv: pointer to the uart low level driver structure for this port
2704 * @uport: uart port structure for this port
2705 *
2706 * This unhooks (and hangs up) the specified port structure from the
2707 * core driver. No further calls will be made to the low-level code
2708 * for this port.
2709 */
2710int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2711{
2712 struct uart_state *state = drv->state + uport->line;
2713 struct tty_port *port = &state->port;
2714 struct tty_struct *tty;
2715 int ret = 0;
2716
2717 BUG_ON(in_interrupt());
2718
2719 if (state->uart_port != uport)
2720 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2721 state->uart_port, uport);
2722
2723 mutex_lock(&port_mutex);
2724
2725 /*
2726 * Mark the port "dead" - this prevents any opens from
2727 * succeeding while we shut down the port.
2728 */
2729 mutex_lock(&port->mutex);
2730 if (!state->uart_port) {
2731 mutex_unlock(&port->mutex);
2732 ret = -EINVAL;
2733 goto out;
2734 }
2735 uport->flags |= UPF_DEAD;
2736 mutex_unlock(&port->mutex);
2737
2738 /*
2739 * Remove the devices from the tty layer
2740 */
2741 tty_unregister_device(drv->tty_driver, uport->line);
2742
2743 tty = tty_port_tty_get(port);
2744 if (tty) {
2745 tty_vhangup(port->tty);
2746 tty_kref_put(tty);
2747 }
2748
2749 /*
2750 * If the port is used as a console, unregister it
2751 */
2752 if (uart_console(uport))
2753 unregister_console(uport->cons);
2754
2755 /*
2756 * Free the port IO and memory resources, if any.
2757 */
2758 if (uport->type != PORT_UNKNOWN)
2759 uport->ops->release_port(uport);
2760 kfree(uport->tty_groups);
2761
2762 /*
2763 * Indicate that there isn't a port here anymore.
2764 */
2765 uport->type = PORT_UNKNOWN;
2766
2767 state->uart_port = NULL;
2768out:
2769 mutex_unlock(&port_mutex);
2770
2771 return ret;
2772}
2773
2774/*
2775 * Are the two ports equivalent?
2776 */
2777int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2778{
2779 if (port1->iotype != port2->iotype)
2780 return 0;
2781
2782 switch (port1->iotype) {
2783 case UPIO_PORT:
2784 return (port1->iobase == port2->iobase);
2785 case UPIO_HUB6:
2786 return (port1->iobase == port2->iobase) &&
2787 (port1->hub6 == port2->hub6);
2788 case UPIO_MEM:
2789 case UPIO_MEM16:
2790 case UPIO_MEM32:
2791 case UPIO_MEM32BE:
2792 case UPIO_AU:
2793 case UPIO_TSI:
2794 return (port1->mapbase == port2->mapbase);
2795 }
2796 return 0;
2797}
2798EXPORT_SYMBOL(uart_match_port);
2799
2800/**
2801 * uart_handle_dcd_change - handle a change of carrier detect state
2802 * @uport: uart_port structure for the open port
2803 * @status: new carrier detect status, nonzero if active
2804 *
2805 * Caller must hold uport->lock
2806 */
2807void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2808{
2809 struct tty_port *port = &uport->state->port;
2810 struct tty_struct *tty = port->tty;
2811 struct tty_ldisc *ld;
2812
2813 lockdep_assert_held_once(&uport->lock);
2814
2815 if (tty) {
2816 ld = tty_ldisc_ref(tty);
2817 if (ld) {
2818 if (ld->ops->dcd_change)
2819 ld->ops->dcd_change(tty, status);
2820 tty_ldisc_deref(ld);
2821 }
2822 }
2823
2824 uport->icount.dcd++;
2825
2826 if (uart_dcd_enabled(uport)) {
2827 if (status)
2828 wake_up_interruptible(&port->open_wait);
2829 else if (tty)
2830 tty_hangup(tty);
2831 }
2832}
2833EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2834
2835/**
2836 * uart_handle_cts_change - handle a change of clear-to-send state
2837 * @uport: uart_port structure for the open port
2838 * @status: new clear to send status, nonzero if active
2839 *
2840 * Caller must hold uport->lock
2841 */
2842void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2843{
2844 lockdep_assert_held_once(&uport->lock);
2845
2846 uport->icount.cts++;
2847
2848 if (uart_softcts_mode(uport)) {
2849 if (uport->hw_stopped) {
2850 if (status) {
2851 uport->hw_stopped = 0;
2852 uport->ops->start_tx(uport);
2853 uart_write_wakeup(uport);
2854 }
2855 } else {
2856 if (!status) {
2857 uport->hw_stopped = 1;
2858 uport->ops->stop_tx(uport);
2859 }
2860 }
2861
2862 }
2863}
2864EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2865
2866/**
2867 * uart_insert_char - push a char to the uart layer
2868 *
2869 * User is responsible to call tty_flip_buffer_push when they are done with
2870 * insertion.
2871 *
2872 * @port: corresponding port
2873 * @status: state of the serial port RX buffer (LSR for 8250)
2874 * @overrun: mask of overrun bits in @status
2875 * @ch: character to push
2876 * @flag: flag for the character (see TTY_NORMAL and friends)
2877 */
2878void uart_insert_char(struct uart_port *port, unsigned int status,
2879 unsigned int overrun, unsigned int ch, unsigned int flag)
2880{
2881 struct tty_port *tport = &port->state->port;
2882
2883 if ((status & port->ignore_status_mask & ~overrun) == 0)
2884 if (tty_insert_flip_char(tport, ch, flag) == 0)
2885 ++port->icount.buf_overrun;
2886
2887 /*
2888 * Overrun is special. Since it's reported immediately,
2889 * it doesn't affect the current character.
2890 */
2891 if (status & ~port->ignore_status_mask & overrun)
2892 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2893 ++port->icount.buf_overrun;
2894}
2895EXPORT_SYMBOL_GPL(uart_insert_char);
2896
2897EXPORT_SYMBOL(uart_write_wakeup);
2898EXPORT_SYMBOL(uart_register_driver);
2899EXPORT_SYMBOL(uart_unregister_driver);
2900EXPORT_SYMBOL(uart_suspend_port);
2901EXPORT_SYMBOL(uart_resume_port);
2902EXPORT_SYMBOL(uart_add_one_port);
2903EXPORT_SYMBOL(uart_remove_one_port);
2904
2905MODULE_DESCRIPTION("Serial driver core");
2906MODULE_LICENSE("GPL");