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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// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Driver core for serial ports
4 *
5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 *
7 * Copyright 1999 ARM Limited
8 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
9 */
10#include <linux/module.h>
11#include <linux/tty.h>
12#include <linux/tty_flip.h>
13#include <linux/slab.h>
14#include <linux/sched/signal.h>
15#include <linux/init.h>
16#include <linux/console.h>
17#include <linux/gpio/consumer.h>
18#include <linux/of.h>
19#include <linux/proc_fs.h>
20#include <linux/seq_file.h>
21#include <linux/device.h>
22#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
23#include <linux/serial_core.h>
24#include <linux/sysrq.h>
25#include <linux/delay.h>
26#include <linux/mutex.h>
27#include <linux/security.h>
28
29#include <linux/irq.h>
30#include <linux/uaccess.h>
31
32/*
33 * This is used to lock changes in serial line configuration.
34 */
35static DEFINE_MUTEX(port_mutex);
36
37/*
38 * lockdep: port->lock is initialized in two places, but we
39 * want only one lock-class:
40 */
41static struct lock_class_key port_lock_key;
42
43#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
44
45static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
46 struct ktermios *old_termios);
47static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
48static void uart_change_pm(struct uart_state *state,
49 enum uart_pm_state pm_state);
50
51static void uart_port_shutdown(struct tty_port *port);
52
53static int uart_dcd_enabled(struct uart_port *uport)
54{
55 return !!(uport->status & UPSTAT_DCD_ENABLE);
56}
57
58static inline struct uart_port *uart_port_ref(struct uart_state *state)
59{
60 if (atomic_add_unless(&state->refcount, 1, 0))
61 return state->uart_port;
62 return NULL;
63}
64
65static inline void uart_port_deref(struct uart_port *uport)
66{
67 if (atomic_dec_and_test(&uport->state->refcount))
68 wake_up(&uport->state->remove_wait);
69}
70
71#define uart_port_lock(state, flags) \
72 ({ \
73 struct uart_port *__uport = uart_port_ref(state); \
74 if (__uport) \
75 spin_lock_irqsave(&__uport->lock, flags); \
76 __uport; \
77 })
78
79#define uart_port_unlock(uport, flags) \
80 ({ \
81 struct uart_port *__uport = uport; \
82 if (__uport) { \
83 spin_unlock_irqrestore(&__uport->lock, flags); \
84 uart_port_deref(__uport); \
85 } \
86 })
87
88static inline struct uart_port *uart_port_check(struct uart_state *state)
89{
90 lockdep_assert_held(&state->port.mutex);
91 return state->uart_port;
92}
93
94/*
95 * This routine is used by the interrupt handler to schedule processing in
96 * the software interrupt portion of the driver.
97 */
98void uart_write_wakeup(struct uart_port *port)
99{
100 struct uart_state *state = port->state;
101 /*
102 * This means you called this function _after_ the port was
103 * closed. No cookie for you.
104 */
105 BUG_ON(!state);
106 tty_port_tty_wakeup(&state->port);
107}
108
109static void uart_stop(struct tty_struct *tty)
110{
111 struct uart_state *state = tty->driver_data;
112 struct uart_port *port;
113 unsigned long flags;
114
115 port = uart_port_lock(state, flags);
116 if (port)
117 port->ops->stop_tx(port);
118 uart_port_unlock(port, flags);
119}
120
121static void __uart_start(struct tty_struct *tty)
122{
123 struct uart_state *state = tty->driver_data;
124 struct uart_port *port = state->uart_port;
125
126 if (port && !uart_tx_stopped(port))
127 port->ops->start_tx(port);
128}
129
130static void uart_start(struct tty_struct *tty)
131{
132 struct uart_state *state = tty->driver_data;
133 struct uart_port *port;
134 unsigned long flags;
135
136 port = uart_port_lock(state, flags);
137 __uart_start(tty);
138 uart_port_unlock(port, flags);
139}
140
141static void
142uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
143{
144 unsigned long flags;
145 unsigned int old;
146
147 spin_lock_irqsave(&port->lock, flags);
148 old = port->mctrl;
149 port->mctrl = (old & ~clear) | set;
150 if (old != port->mctrl)
151 port->ops->set_mctrl(port, port->mctrl);
152 spin_unlock_irqrestore(&port->lock, flags);
153}
154
155#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
156#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
157
158static void uart_port_dtr_rts(struct uart_port *uport, int raise)
159{
160 int rs485_on = uport->rs485_config &&
161 (uport->rs485.flags & SER_RS485_ENABLED);
162 int RTS_after_send = !!(uport->rs485.flags & SER_RS485_RTS_AFTER_SEND);
163
164 if (raise) {
165 if (rs485_on && !RTS_after_send) {
166 uart_set_mctrl(uport, TIOCM_DTR);
167 uart_clear_mctrl(uport, TIOCM_RTS);
168 } else {
169 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
170 }
171 } else {
172 unsigned int clear = TIOCM_DTR;
173
174 clear |= (!rs485_on || !RTS_after_send) ? TIOCM_RTS : 0;
175 uart_clear_mctrl(uport, clear);
176 }
177}
178
179/*
180 * Startup the port. This will be called once per open. All calls
181 * will be serialised by the per-port mutex.
182 */
183static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
184 int init_hw)
185{
186 struct uart_port *uport = uart_port_check(state);
187 unsigned long page;
188 unsigned long flags = 0;
189 int retval = 0;
190
191 if (uport->type == PORT_UNKNOWN)
192 return 1;
193
194 /*
195 * Make sure the device is in D0 state.
196 */
197 uart_change_pm(state, UART_PM_STATE_ON);
198
199 /*
200 * Initialise and allocate the transmit and temporary
201 * buffer.
202 */
203 page = get_zeroed_page(GFP_KERNEL);
204 if (!page)
205 return -ENOMEM;
206
207 uart_port_lock(state, flags);
208 if (!state->xmit.buf) {
209 state->xmit.buf = (unsigned char *) page;
210 uart_circ_clear(&state->xmit);
211 uart_port_unlock(uport, flags);
212 } else {
213 uart_port_unlock(uport, flags);
214 /*
215 * Do not free() the page under the port lock, see
216 * uart_shutdown().
217 */
218 free_page(page);
219 }
220
221 retval = uport->ops->startup(uport);
222 if (retval == 0) {
223 if (uart_console(uport) && uport->cons->cflag) {
224 tty->termios.c_cflag = uport->cons->cflag;
225 uport->cons->cflag = 0;
226 }
227 /*
228 * Initialise the hardware port settings.
229 */
230 uart_change_speed(tty, state, NULL);
231
232 /*
233 * Setup the RTS and DTR signals once the
234 * port is open and ready to respond.
235 */
236 if (init_hw && C_BAUD(tty))
237 uart_port_dtr_rts(uport, 1);
238 }
239
240 /*
241 * This is to allow setserial on this port. People may want to set
242 * port/irq/type and then reconfigure the port properly if it failed
243 * now.
244 */
245 if (retval && capable(CAP_SYS_ADMIN))
246 return 1;
247
248 return retval;
249}
250
251static int uart_startup(struct tty_struct *tty, struct uart_state *state,
252 int init_hw)
253{
254 struct tty_port *port = &state->port;
255 int retval;
256
257 if (tty_port_initialized(port))
258 return 0;
259
260 retval = uart_port_startup(tty, state, init_hw);
261 if (retval)
262 set_bit(TTY_IO_ERROR, &tty->flags);
263
264 return retval;
265}
266
267/*
268 * This routine will shutdown a serial port; interrupts are disabled, and
269 * DTR is dropped if the hangup on close termio flag is on. Calls to
270 * uart_shutdown are serialised by the per-port semaphore.
271 *
272 * uport == NULL if uart_port has already been removed
273 */
274static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
275{
276 struct uart_port *uport = uart_port_check(state);
277 struct tty_port *port = &state->port;
278 unsigned long flags = 0;
279 char *xmit_buf = NULL;
280
281 /*
282 * Set the TTY IO error marker
283 */
284 if (tty)
285 set_bit(TTY_IO_ERROR, &tty->flags);
286
287 if (tty_port_initialized(port)) {
288 tty_port_set_initialized(port, 0);
289
290 /*
291 * Turn off DTR and RTS early.
292 */
293 if (uport && uart_console(uport) && tty)
294 uport->cons->cflag = tty->termios.c_cflag;
295
296 if (!tty || C_HUPCL(tty))
297 uart_port_dtr_rts(uport, 0);
298
299 uart_port_shutdown(port);
300 }
301
302 /*
303 * It's possible for shutdown to be called after suspend if we get
304 * a DCD drop (hangup) at just the right time. Clear suspended bit so
305 * we don't try to resume a port that has been shutdown.
306 */
307 tty_port_set_suspended(port, 0);
308
309 /*
310 * Do not free() the transmit buffer page under the port lock since
311 * this can create various circular locking scenarios. For instance,
312 * console driver may need to allocate/free a debug object, which
313 * can endup in printk() recursion.
314 */
315 uart_port_lock(state, flags);
316 xmit_buf = state->xmit.buf;
317 state->xmit.buf = NULL;
318 uart_port_unlock(uport, flags);
319
320 if (xmit_buf)
321 free_page((unsigned long)xmit_buf);
322}
323
324/**
325 * uart_update_timeout - update per-port FIFO timeout.
326 * @port: uart_port structure describing the port
327 * @cflag: termios cflag value
328 * @baud: speed of the port
329 *
330 * Set the port FIFO timeout value. The @cflag value should
331 * reflect the actual hardware settings.
332 */
333void
334uart_update_timeout(struct uart_port *port, unsigned int cflag,
335 unsigned int baud)
336{
337 unsigned int bits;
338
339 /* byte size and parity */
340 switch (cflag & CSIZE) {
341 case CS5:
342 bits = 7;
343 break;
344 case CS6:
345 bits = 8;
346 break;
347 case CS7:
348 bits = 9;
349 break;
350 default:
351 bits = 10;
352 break; /* CS8 */
353 }
354
355 if (cflag & CSTOPB)
356 bits++;
357 if (cflag & PARENB)
358 bits++;
359
360 /*
361 * The total number of bits to be transmitted in the fifo.
362 */
363 bits = bits * port->fifosize;
364
365 /*
366 * Figure the timeout to send the above number of bits.
367 * Add .02 seconds of slop
368 */
369 port->timeout = (HZ * bits) / baud + HZ/50;
370}
371
372EXPORT_SYMBOL(uart_update_timeout);
373
374/**
375 * uart_get_baud_rate - return baud rate for a particular port
376 * @port: uart_port structure describing the port in question.
377 * @termios: desired termios settings.
378 * @old: old termios (or NULL)
379 * @min: minimum acceptable baud rate
380 * @max: maximum acceptable baud rate
381 *
382 * Decode the termios structure into a numeric baud rate,
383 * taking account of the magic 38400 baud rate (with spd_*
384 * flags), and mapping the %B0 rate to 9600 baud.
385 *
386 * If the new baud rate is invalid, try the old termios setting.
387 * If it's still invalid, we try 9600 baud.
388 *
389 * Update the @termios structure to reflect the baud rate
390 * we're actually going to be using. Don't do this for the case
391 * where B0 is requested ("hang up").
392 */
393unsigned int
394uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
395 struct ktermios *old, unsigned int min, unsigned int max)
396{
397 unsigned int try;
398 unsigned int baud;
399 unsigned int altbaud;
400 int hung_up = 0;
401 upf_t flags = port->flags & UPF_SPD_MASK;
402
403 switch (flags) {
404 case UPF_SPD_HI:
405 altbaud = 57600;
406 break;
407 case UPF_SPD_VHI:
408 altbaud = 115200;
409 break;
410 case UPF_SPD_SHI:
411 altbaud = 230400;
412 break;
413 case UPF_SPD_WARP:
414 altbaud = 460800;
415 break;
416 default:
417 altbaud = 38400;
418 break;
419 }
420
421 for (try = 0; try < 2; try++) {
422 baud = tty_termios_baud_rate(termios);
423
424 /*
425 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
426 * Die! Die! Die!
427 */
428 if (try == 0 && baud == 38400)
429 baud = altbaud;
430
431 /*
432 * Special case: B0 rate.
433 */
434 if (baud == 0) {
435 hung_up = 1;
436 baud = 9600;
437 }
438
439 if (baud >= min && baud <= max)
440 return baud;
441
442 /*
443 * Oops, the quotient was zero. Try again with
444 * the old baud rate if possible.
445 */
446 termios->c_cflag &= ~CBAUD;
447 if (old) {
448 baud = tty_termios_baud_rate(old);
449 if (!hung_up)
450 tty_termios_encode_baud_rate(termios,
451 baud, baud);
452 old = NULL;
453 continue;
454 }
455
456 /*
457 * As a last resort, if the range cannot be met then clip to
458 * the nearest chip supported rate.
459 */
460 if (!hung_up) {
461 if (baud <= min)
462 tty_termios_encode_baud_rate(termios,
463 min + 1, min + 1);
464 else
465 tty_termios_encode_baud_rate(termios,
466 max - 1, max - 1);
467 }
468 }
469 /* Should never happen */
470 WARN_ON(1);
471 return 0;
472}
473
474EXPORT_SYMBOL(uart_get_baud_rate);
475
476/**
477 * uart_get_divisor - return uart clock divisor
478 * @port: uart_port structure describing the port.
479 * @baud: desired baud rate
480 *
481 * Calculate the uart clock divisor for the port.
482 */
483unsigned int
484uart_get_divisor(struct uart_port *port, unsigned int baud)
485{
486 unsigned int quot;
487
488 /*
489 * Old custom speed handling.
490 */
491 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
492 quot = port->custom_divisor;
493 else
494 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
495
496 return quot;
497}
498
499EXPORT_SYMBOL(uart_get_divisor);
500
501/* Caller holds port mutex */
502static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
503 struct ktermios *old_termios)
504{
505 struct uart_port *uport = uart_port_check(state);
506 struct ktermios *termios;
507 int hw_stopped;
508
509 /*
510 * If we have no tty, termios, or the port does not exist,
511 * then we can't set the parameters for this port.
512 */
513 if (!tty || uport->type == PORT_UNKNOWN)
514 return;
515
516 termios = &tty->termios;
517 uport->ops->set_termios(uport, termios, old_termios);
518
519 /*
520 * Set modem status enables based on termios cflag
521 */
522 spin_lock_irq(&uport->lock);
523 if (termios->c_cflag & CRTSCTS)
524 uport->status |= UPSTAT_CTS_ENABLE;
525 else
526 uport->status &= ~UPSTAT_CTS_ENABLE;
527
528 if (termios->c_cflag & CLOCAL)
529 uport->status &= ~UPSTAT_DCD_ENABLE;
530 else
531 uport->status |= UPSTAT_DCD_ENABLE;
532
533 /* reset sw-assisted CTS flow control based on (possibly) new mode */
534 hw_stopped = uport->hw_stopped;
535 uport->hw_stopped = uart_softcts_mode(uport) &&
536 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
537 if (uport->hw_stopped) {
538 if (!hw_stopped)
539 uport->ops->stop_tx(uport);
540 } else {
541 if (hw_stopped)
542 __uart_start(tty);
543 }
544 spin_unlock_irq(&uport->lock);
545}
546
547static int uart_put_char(struct tty_struct *tty, unsigned char c)
548{
549 struct uart_state *state = tty->driver_data;
550 struct uart_port *port;
551 struct circ_buf *circ;
552 unsigned long flags;
553 int ret = 0;
554
555 circ = &state->xmit;
556 port = uart_port_lock(state, flags);
557 if (!circ->buf) {
558 uart_port_unlock(port, flags);
559 return 0;
560 }
561
562 if (port && uart_circ_chars_free(circ) != 0) {
563 circ->buf[circ->head] = c;
564 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
565 ret = 1;
566 }
567 uart_port_unlock(port, flags);
568 return ret;
569}
570
571static void uart_flush_chars(struct tty_struct *tty)
572{
573 uart_start(tty);
574}
575
576static int uart_write(struct tty_struct *tty,
577 const unsigned char *buf, int count)
578{
579 struct uart_state *state = tty->driver_data;
580 struct uart_port *port;
581 struct circ_buf *circ;
582 unsigned long flags;
583 int c, ret = 0;
584
585 /*
586 * This means you called this function _after_ the port was
587 * closed. No cookie for you.
588 */
589 if (!state) {
590 WARN_ON(1);
591 return -EL3HLT;
592 }
593
594 port = uart_port_lock(state, flags);
595 circ = &state->xmit;
596 if (!circ->buf) {
597 uart_port_unlock(port, flags);
598 return 0;
599 }
600
601 while (port) {
602 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
603 if (count < c)
604 c = count;
605 if (c <= 0)
606 break;
607 memcpy(circ->buf + circ->head, buf, c);
608 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
609 buf += c;
610 count -= c;
611 ret += c;
612 }
613
614 __uart_start(tty);
615 uart_port_unlock(port, flags);
616 return ret;
617}
618
619static int uart_write_room(struct tty_struct *tty)
620{
621 struct uart_state *state = tty->driver_data;
622 struct uart_port *port;
623 unsigned long flags;
624 int ret;
625
626 port = uart_port_lock(state, flags);
627 ret = uart_circ_chars_free(&state->xmit);
628 uart_port_unlock(port, flags);
629 return ret;
630}
631
632static int uart_chars_in_buffer(struct tty_struct *tty)
633{
634 struct uart_state *state = tty->driver_data;
635 struct uart_port *port;
636 unsigned long flags;
637 int ret;
638
639 port = uart_port_lock(state, flags);
640 ret = uart_circ_chars_pending(&state->xmit);
641 uart_port_unlock(port, flags);
642 return ret;
643}
644
645static void uart_flush_buffer(struct tty_struct *tty)
646{
647 struct uart_state *state = tty->driver_data;
648 struct uart_port *port;
649 unsigned long flags;
650
651 /*
652 * This means you called this function _after_ the port was
653 * closed. No cookie for you.
654 */
655 if (!state) {
656 WARN_ON(1);
657 return;
658 }
659
660 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
661
662 port = uart_port_lock(state, flags);
663 if (!port)
664 return;
665 uart_circ_clear(&state->xmit);
666 if (port->ops->flush_buffer)
667 port->ops->flush_buffer(port);
668 uart_port_unlock(port, flags);
669 tty_port_tty_wakeup(&state->port);
670}
671
672/*
673 * This function is used to send a high-priority XON/XOFF character to
674 * the device
675 */
676static void uart_send_xchar(struct tty_struct *tty, char ch)
677{
678 struct uart_state *state = tty->driver_data;
679 struct uart_port *port;
680 unsigned long flags;
681
682 port = uart_port_ref(state);
683 if (!port)
684 return;
685
686 if (port->ops->send_xchar)
687 port->ops->send_xchar(port, ch);
688 else {
689 spin_lock_irqsave(&port->lock, flags);
690 port->x_char = ch;
691 if (ch)
692 port->ops->start_tx(port);
693 spin_unlock_irqrestore(&port->lock, flags);
694 }
695 uart_port_deref(port);
696}
697
698static void uart_throttle(struct tty_struct *tty)
699{
700 struct uart_state *state = tty->driver_data;
701 upstat_t mask = UPSTAT_SYNC_FIFO;
702 struct uart_port *port;
703
704 port = uart_port_ref(state);
705 if (!port)
706 return;
707
708 if (I_IXOFF(tty))
709 mask |= UPSTAT_AUTOXOFF;
710 if (C_CRTSCTS(tty))
711 mask |= UPSTAT_AUTORTS;
712
713 if (port->status & mask) {
714 port->ops->throttle(port);
715 mask &= ~port->status;
716 }
717
718 if (mask & UPSTAT_AUTORTS)
719 uart_clear_mctrl(port, TIOCM_RTS);
720
721 if (mask & UPSTAT_AUTOXOFF)
722 uart_send_xchar(tty, STOP_CHAR(tty));
723
724 uart_port_deref(port);
725}
726
727static void uart_unthrottle(struct tty_struct *tty)
728{
729 struct uart_state *state = tty->driver_data;
730 upstat_t mask = UPSTAT_SYNC_FIFO;
731 struct uart_port *port;
732
733 port = uart_port_ref(state);
734 if (!port)
735 return;
736
737 if (I_IXOFF(tty))
738 mask |= UPSTAT_AUTOXOFF;
739 if (C_CRTSCTS(tty))
740 mask |= UPSTAT_AUTORTS;
741
742 if (port->status & mask) {
743 port->ops->unthrottle(port);
744 mask &= ~port->status;
745 }
746
747 if (mask & UPSTAT_AUTORTS)
748 uart_set_mctrl(port, TIOCM_RTS);
749
750 if (mask & UPSTAT_AUTOXOFF)
751 uart_send_xchar(tty, START_CHAR(tty));
752
753 uart_port_deref(port);
754}
755
756static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
757{
758 struct uart_state *state = container_of(port, struct uart_state, port);
759 struct uart_port *uport;
760 int ret = -ENODEV;
761
762 memset(retinfo, 0, sizeof(*retinfo));
763
764 /*
765 * Ensure the state we copy is consistent and no hardware changes
766 * occur as we go
767 */
768 mutex_lock(&port->mutex);
769 uport = uart_port_check(state);
770 if (!uport)
771 goto out;
772
773 retinfo->type = uport->type;
774 retinfo->line = uport->line;
775 retinfo->port = uport->iobase;
776 if (HIGH_BITS_OFFSET)
777 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
778 retinfo->irq = uport->irq;
779 retinfo->flags = (__force int)uport->flags;
780 retinfo->xmit_fifo_size = uport->fifosize;
781 retinfo->baud_base = uport->uartclk / 16;
782 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
783 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
784 ASYNC_CLOSING_WAIT_NONE :
785 jiffies_to_msecs(port->closing_wait) / 10;
786 retinfo->custom_divisor = uport->custom_divisor;
787 retinfo->hub6 = uport->hub6;
788 retinfo->io_type = uport->iotype;
789 retinfo->iomem_reg_shift = uport->regshift;
790 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
791
792 ret = 0;
793out:
794 mutex_unlock(&port->mutex);
795 return ret;
796}
797
798static int uart_get_info_user(struct tty_struct *tty,
799 struct serial_struct *ss)
800{
801 struct uart_state *state = tty->driver_data;
802 struct tty_port *port = &state->port;
803
804 return uart_get_info(port, ss) < 0 ? -EIO : 0;
805}
806
807static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
808 struct uart_state *state,
809 struct serial_struct *new_info)
810{
811 struct uart_port *uport = uart_port_check(state);
812 unsigned long new_port;
813 unsigned int change_irq, change_port, closing_wait;
814 unsigned int old_custom_divisor, close_delay;
815 upf_t old_flags, new_flags;
816 int retval = 0;
817
818 if (!uport)
819 return -EIO;
820
821 new_port = new_info->port;
822 if (HIGH_BITS_OFFSET)
823 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
824
825 new_info->irq = irq_canonicalize(new_info->irq);
826 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
827 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
828 ASYNC_CLOSING_WAIT_NONE :
829 msecs_to_jiffies(new_info->closing_wait * 10);
830
831
832 change_irq = !(uport->flags & UPF_FIXED_PORT)
833 && new_info->irq != uport->irq;
834
835 /*
836 * Since changing the 'type' of the port changes its resource
837 * allocations, we should treat type changes the same as
838 * IO port changes.
839 */
840 change_port = !(uport->flags & UPF_FIXED_PORT)
841 && (new_port != uport->iobase ||
842 (unsigned long)new_info->iomem_base != uport->mapbase ||
843 new_info->hub6 != uport->hub6 ||
844 new_info->io_type != uport->iotype ||
845 new_info->iomem_reg_shift != uport->regshift ||
846 new_info->type != uport->type);
847
848 old_flags = uport->flags;
849 new_flags = (__force upf_t)new_info->flags;
850 old_custom_divisor = uport->custom_divisor;
851
852 if (!capable(CAP_SYS_ADMIN)) {
853 retval = -EPERM;
854 if (change_irq || change_port ||
855 (new_info->baud_base != uport->uartclk / 16) ||
856 (close_delay != port->close_delay) ||
857 (closing_wait != port->closing_wait) ||
858 (new_info->xmit_fifo_size &&
859 new_info->xmit_fifo_size != uport->fifosize) ||
860 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
861 goto exit;
862 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
863 (new_flags & UPF_USR_MASK));
864 uport->custom_divisor = new_info->custom_divisor;
865 goto check_and_exit;
866 }
867
868 retval = security_locked_down(LOCKDOWN_TIOCSSERIAL);
869 if (retval && (change_irq || change_port))
870 goto exit;
871
872 /*
873 * Ask the low level driver to verify the settings.
874 */
875 if (uport->ops->verify_port)
876 retval = uport->ops->verify_port(uport, new_info);
877
878 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
879 (new_info->baud_base < 9600))
880 retval = -EINVAL;
881
882 if (retval)
883 goto exit;
884
885 if (change_port || change_irq) {
886 retval = -EBUSY;
887
888 /*
889 * Make sure that we are the sole user of this port.
890 */
891 if (tty_port_users(port) > 1)
892 goto exit;
893
894 /*
895 * We need to shutdown the serial port at the old
896 * port/type/irq combination.
897 */
898 uart_shutdown(tty, state);
899 }
900
901 if (change_port) {
902 unsigned long old_iobase, old_mapbase;
903 unsigned int old_type, old_iotype, old_hub6, old_shift;
904
905 old_iobase = uport->iobase;
906 old_mapbase = uport->mapbase;
907 old_type = uport->type;
908 old_hub6 = uport->hub6;
909 old_iotype = uport->iotype;
910 old_shift = uport->regshift;
911
912 /*
913 * Free and release old regions
914 */
915 if (old_type != PORT_UNKNOWN && uport->ops->release_port)
916 uport->ops->release_port(uport);
917
918 uport->iobase = new_port;
919 uport->type = new_info->type;
920 uport->hub6 = new_info->hub6;
921 uport->iotype = new_info->io_type;
922 uport->regshift = new_info->iomem_reg_shift;
923 uport->mapbase = (unsigned long)new_info->iomem_base;
924
925 /*
926 * Claim and map the new regions
927 */
928 if (uport->type != PORT_UNKNOWN && uport->ops->request_port) {
929 retval = uport->ops->request_port(uport);
930 } else {
931 /* Always success - Jean II */
932 retval = 0;
933 }
934
935 /*
936 * If we fail to request resources for the
937 * new port, try to restore the old settings.
938 */
939 if (retval) {
940 uport->iobase = old_iobase;
941 uport->type = old_type;
942 uport->hub6 = old_hub6;
943 uport->iotype = old_iotype;
944 uport->regshift = old_shift;
945 uport->mapbase = old_mapbase;
946
947 if (old_type != PORT_UNKNOWN) {
948 retval = uport->ops->request_port(uport);
949 /*
950 * If we failed to restore the old settings,
951 * we fail like this.
952 */
953 if (retval)
954 uport->type = PORT_UNKNOWN;
955
956 /*
957 * We failed anyway.
958 */
959 retval = -EBUSY;
960 }
961
962 /* Added to return the correct error -Ram Gupta */
963 goto exit;
964 }
965 }
966
967 if (change_irq)
968 uport->irq = new_info->irq;
969 if (!(uport->flags & UPF_FIXED_PORT))
970 uport->uartclk = new_info->baud_base * 16;
971 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
972 (new_flags & UPF_CHANGE_MASK);
973 uport->custom_divisor = new_info->custom_divisor;
974 port->close_delay = close_delay;
975 port->closing_wait = closing_wait;
976 if (new_info->xmit_fifo_size)
977 uport->fifosize = new_info->xmit_fifo_size;
978 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
979
980 check_and_exit:
981 retval = 0;
982 if (uport->type == PORT_UNKNOWN)
983 goto exit;
984 if (tty_port_initialized(port)) {
985 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
986 old_custom_divisor != uport->custom_divisor) {
987 /*
988 * If they're setting up a custom divisor or speed,
989 * instead of clearing it, then bitch about it.
990 */
991 if (uport->flags & UPF_SPD_MASK) {
992 dev_notice_ratelimited(uport->dev,
993 "%s sets custom speed on %s. This is deprecated.\n",
994 current->comm,
995 tty_name(port->tty));
996 }
997 uart_change_speed(tty, state, NULL);
998 }
999 } else {
1000 retval = uart_startup(tty, state, 1);
1001 if (retval == 0)
1002 tty_port_set_initialized(port, true);
1003 if (retval > 0)
1004 retval = 0;
1005 }
1006 exit:
1007 return retval;
1008}
1009
1010static int uart_set_info_user(struct tty_struct *tty, struct serial_struct *ss)
1011{
1012 struct uart_state *state = tty->driver_data;
1013 struct tty_port *port = &state->port;
1014 int retval;
1015
1016 down_write(&tty->termios_rwsem);
1017 /*
1018 * This semaphore protects port->count. It is also
1019 * very useful to prevent opens. Also, take the
1020 * port configuration semaphore to make sure that a
1021 * module insertion/removal doesn't change anything
1022 * under us.
1023 */
1024 mutex_lock(&port->mutex);
1025 retval = uart_set_info(tty, port, state, ss);
1026 mutex_unlock(&port->mutex);
1027 up_write(&tty->termios_rwsem);
1028 return retval;
1029}
1030
1031/**
1032 * uart_get_lsr_info - get line status register info
1033 * @tty: tty associated with the UART
1034 * @state: UART being queried
1035 * @value: returned modem value
1036 */
1037static int uart_get_lsr_info(struct tty_struct *tty,
1038 struct uart_state *state, unsigned int __user *value)
1039{
1040 struct uart_port *uport = uart_port_check(state);
1041 unsigned int result;
1042
1043 result = uport->ops->tx_empty(uport);
1044
1045 /*
1046 * If we're about to load something into the transmit
1047 * register, we'll pretend the transmitter isn't empty to
1048 * avoid a race condition (depending on when the transmit
1049 * interrupt happens).
1050 */
1051 if (uport->x_char ||
1052 ((uart_circ_chars_pending(&state->xmit) > 0) &&
1053 !uart_tx_stopped(uport)))
1054 result &= ~TIOCSER_TEMT;
1055
1056 return put_user(result, value);
1057}
1058
1059static int uart_tiocmget(struct tty_struct *tty)
1060{
1061 struct uart_state *state = tty->driver_data;
1062 struct tty_port *port = &state->port;
1063 struct uart_port *uport;
1064 int result = -EIO;
1065
1066 mutex_lock(&port->mutex);
1067 uport = uart_port_check(state);
1068 if (!uport)
1069 goto out;
1070
1071 if (!tty_io_error(tty)) {
1072 result = uport->mctrl;
1073 spin_lock_irq(&uport->lock);
1074 result |= uport->ops->get_mctrl(uport);
1075 spin_unlock_irq(&uport->lock);
1076 }
1077out:
1078 mutex_unlock(&port->mutex);
1079 return result;
1080}
1081
1082static int
1083uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
1084{
1085 struct uart_state *state = tty->driver_data;
1086 struct tty_port *port = &state->port;
1087 struct uart_port *uport;
1088 int ret = -EIO;
1089
1090 mutex_lock(&port->mutex);
1091 uport = uart_port_check(state);
1092 if (!uport)
1093 goto out;
1094
1095 if (!tty_io_error(tty)) {
1096 uart_update_mctrl(uport, set, clear);
1097 ret = 0;
1098 }
1099out:
1100 mutex_unlock(&port->mutex);
1101 return ret;
1102}
1103
1104static int uart_break_ctl(struct tty_struct *tty, int break_state)
1105{
1106 struct uart_state *state = tty->driver_data;
1107 struct tty_port *port = &state->port;
1108 struct uart_port *uport;
1109 int ret = -EIO;
1110
1111 mutex_lock(&port->mutex);
1112 uport = uart_port_check(state);
1113 if (!uport)
1114 goto out;
1115
1116 if (uport->type != PORT_UNKNOWN && uport->ops->break_ctl)
1117 uport->ops->break_ctl(uport, break_state);
1118 ret = 0;
1119out:
1120 mutex_unlock(&port->mutex);
1121 return ret;
1122}
1123
1124static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state)
1125{
1126 struct tty_port *port = &state->port;
1127 struct uart_port *uport;
1128 int flags, ret;
1129
1130 if (!capable(CAP_SYS_ADMIN))
1131 return -EPERM;
1132
1133 /*
1134 * Take the per-port semaphore. This prevents count from
1135 * changing, and hence any extra opens of the port while
1136 * we're auto-configuring.
1137 */
1138 if (mutex_lock_interruptible(&port->mutex))
1139 return -ERESTARTSYS;
1140
1141 uport = uart_port_check(state);
1142 if (!uport) {
1143 ret = -EIO;
1144 goto out;
1145 }
1146
1147 ret = -EBUSY;
1148 if (tty_port_users(port) == 1) {
1149 uart_shutdown(tty, state);
1150
1151 /*
1152 * If we already have a port type configured,
1153 * we must release its resources.
1154 */
1155 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
1156 uport->ops->release_port(uport);
1157
1158 flags = UART_CONFIG_TYPE;
1159 if (uport->flags & UPF_AUTO_IRQ)
1160 flags |= UART_CONFIG_IRQ;
1161
1162 /*
1163 * This will claim the ports resources if
1164 * a port is found.
1165 */
1166 uport->ops->config_port(uport, flags);
1167
1168 ret = uart_startup(tty, state, 1);
1169 if (ret == 0)
1170 tty_port_set_initialized(port, true);
1171 if (ret > 0)
1172 ret = 0;
1173 }
1174out:
1175 mutex_unlock(&port->mutex);
1176 return ret;
1177}
1178
1179static void uart_enable_ms(struct uart_port *uport)
1180{
1181 /*
1182 * Force modem status interrupts on
1183 */
1184 if (uport->ops->enable_ms)
1185 uport->ops->enable_ms(uport);
1186}
1187
1188/*
1189 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1190 * - mask passed in arg for lines of interest
1191 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1192 * Caller should use TIOCGICOUNT to see which one it was
1193 *
1194 * FIXME: This wants extracting into a common all driver implementation
1195 * of TIOCMWAIT using tty_port.
1196 */
1197static int uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1198{
1199 struct uart_port *uport;
1200 struct tty_port *port = &state->port;
1201 DECLARE_WAITQUEUE(wait, current);
1202 struct uart_icount cprev, cnow;
1203 int ret;
1204
1205 /*
1206 * note the counters on entry
1207 */
1208 uport = uart_port_ref(state);
1209 if (!uport)
1210 return -EIO;
1211 spin_lock_irq(&uport->lock);
1212 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1213 uart_enable_ms(uport);
1214 spin_unlock_irq(&uport->lock);
1215
1216 add_wait_queue(&port->delta_msr_wait, &wait);
1217 for (;;) {
1218 spin_lock_irq(&uport->lock);
1219 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1220 spin_unlock_irq(&uport->lock);
1221
1222 set_current_state(TASK_INTERRUPTIBLE);
1223
1224 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1225 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1226 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1227 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1228 ret = 0;
1229 break;
1230 }
1231
1232 schedule();
1233
1234 /* see if a signal did it */
1235 if (signal_pending(current)) {
1236 ret = -ERESTARTSYS;
1237 break;
1238 }
1239
1240 cprev = cnow;
1241 }
1242 __set_current_state(TASK_RUNNING);
1243 remove_wait_queue(&port->delta_msr_wait, &wait);
1244 uart_port_deref(uport);
1245
1246 return ret;
1247}
1248
1249/*
1250 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1251 * Return: write counters to the user passed counter struct
1252 * NB: both 1->0 and 0->1 transitions are counted except for
1253 * RI where only 0->1 is counted.
1254 */
1255static int uart_get_icount(struct tty_struct *tty,
1256 struct serial_icounter_struct *icount)
1257{
1258 struct uart_state *state = tty->driver_data;
1259 struct uart_icount cnow;
1260 struct uart_port *uport;
1261
1262 uport = uart_port_ref(state);
1263 if (!uport)
1264 return -EIO;
1265 spin_lock_irq(&uport->lock);
1266 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1267 spin_unlock_irq(&uport->lock);
1268 uart_port_deref(uport);
1269
1270 icount->cts = cnow.cts;
1271 icount->dsr = cnow.dsr;
1272 icount->rng = cnow.rng;
1273 icount->dcd = cnow.dcd;
1274 icount->rx = cnow.rx;
1275 icount->tx = cnow.tx;
1276 icount->frame = cnow.frame;
1277 icount->overrun = cnow.overrun;
1278 icount->parity = cnow.parity;
1279 icount->brk = cnow.brk;
1280 icount->buf_overrun = cnow.buf_overrun;
1281
1282 return 0;
1283}
1284
1285static int uart_get_rs485_config(struct uart_port *port,
1286 struct serial_rs485 __user *rs485)
1287{
1288 unsigned long flags;
1289 struct serial_rs485 aux;
1290
1291 spin_lock_irqsave(&port->lock, flags);
1292 aux = port->rs485;
1293 spin_unlock_irqrestore(&port->lock, flags);
1294
1295 if (copy_to_user(rs485, &aux, sizeof(aux)))
1296 return -EFAULT;
1297
1298 return 0;
1299}
1300
1301static int uart_set_rs485_config(struct uart_port *port,
1302 struct serial_rs485 __user *rs485_user)
1303{
1304 struct serial_rs485 rs485;
1305 int ret;
1306 unsigned long flags;
1307
1308 if (!port->rs485_config)
1309 return -ENOIOCTLCMD;
1310
1311 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1312 return -EFAULT;
1313
1314 spin_lock_irqsave(&port->lock, flags);
1315 ret = port->rs485_config(port, &rs485);
1316 spin_unlock_irqrestore(&port->lock, flags);
1317 if (ret)
1318 return ret;
1319
1320 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1321 return -EFAULT;
1322
1323 return 0;
1324}
1325
1326static int uart_get_iso7816_config(struct uart_port *port,
1327 struct serial_iso7816 __user *iso7816)
1328{
1329 unsigned long flags;
1330 struct serial_iso7816 aux;
1331
1332 if (!port->iso7816_config)
1333 return -ENOIOCTLCMD;
1334
1335 spin_lock_irqsave(&port->lock, flags);
1336 aux = port->iso7816;
1337 spin_unlock_irqrestore(&port->lock, flags);
1338
1339 if (copy_to_user(iso7816, &aux, sizeof(aux)))
1340 return -EFAULT;
1341
1342 return 0;
1343}
1344
1345static int uart_set_iso7816_config(struct uart_port *port,
1346 struct serial_iso7816 __user *iso7816_user)
1347{
1348 struct serial_iso7816 iso7816;
1349 int i, ret;
1350 unsigned long flags;
1351
1352 if (!port->iso7816_config)
1353 return -ENOIOCTLCMD;
1354
1355 if (copy_from_user(&iso7816, iso7816_user, sizeof(*iso7816_user)))
1356 return -EFAULT;
1357
1358 /*
1359 * There are 5 words reserved for future use. Check that userspace
1360 * doesn't put stuff in there to prevent breakages in the future.
1361 */
1362 for (i = 0; i < 5; i++)
1363 if (iso7816.reserved[i])
1364 return -EINVAL;
1365
1366 spin_lock_irqsave(&port->lock, flags);
1367 ret = port->iso7816_config(port, &iso7816);
1368 spin_unlock_irqrestore(&port->lock, flags);
1369 if (ret)
1370 return ret;
1371
1372 if (copy_to_user(iso7816_user, &port->iso7816, sizeof(port->iso7816)))
1373 return -EFAULT;
1374
1375 return 0;
1376}
1377
1378/*
1379 * Called via sys_ioctl. We can use spin_lock_irq() here.
1380 */
1381static int
1382uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
1383{
1384 struct uart_state *state = tty->driver_data;
1385 struct tty_port *port = &state->port;
1386 struct uart_port *uport;
1387 void __user *uarg = (void __user *)arg;
1388 int ret = -ENOIOCTLCMD;
1389
1390
1391 /*
1392 * These ioctls don't rely on the hardware to be present.
1393 */
1394 switch (cmd) {
1395 case TIOCSERCONFIG:
1396 down_write(&tty->termios_rwsem);
1397 ret = uart_do_autoconfig(tty, state);
1398 up_write(&tty->termios_rwsem);
1399 break;
1400 }
1401
1402 if (ret != -ENOIOCTLCMD)
1403 goto out;
1404
1405 if (tty_io_error(tty)) {
1406 ret = -EIO;
1407 goto out;
1408 }
1409
1410 /*
1411 * The following should only be used when hardware is present.
1412 */
1413 switch (cmd) {
1414 case TIOCMIWAIT:
1415 ret = uart_wait_modem_status(state, arg);
1416 break;
1417 }
1418
1419 if (ret != -ENOIOCTLCMD)
1420 goto out;
1421
1422 mutex_lock(&port->mutex);
1423 uport = uart_port_check(state);
1424
1425 if (!uport || tty_io_error(tty)) {
1426 ret = -EIO;
1427 goto out_up;
1428 }
1429
1430 /*
1431 * All these rely on hardware being present and need to be
1432 * protected against the tty being hung up.
1433 */
1434
1435 switch (cmd) {
1436 case TIOCSERGETLSR: /* Get line status register */
1437 ret = uart_get_lsr_info(tty, state, uarg);
1438 break;
1439
1440 case TIOCGRS485:
1441 ret = uart_get_rs485_config(uport, uarg);
1442 break;
1443
1444 case TIOCSRS485:
1445 ret = uart_set_rs485_config(uport, uarg);
1446 break;
1447
1448 case TIOCSISO7816:
1449 ret = uart_set_iso7816_config(state->uart_port, uarg);
1450 break;
1451
1452 case TIOCGISO7816:
1453 ret = uart_get_iso7816_config(state->uart_port, uarg);
1454 break;
1455 default:
1456 if (uport->ops->ioctl)
1457 ret = uport->ops->ioctl(uport, cmd, arg);
1458 break;
1459 }
1460out_up:
1461 mutex_unlock(&port->mutex);
1462out:
1463 return ret;
1464}
1465
1466static void uart_set_ldisc(struct tty_struct *tty)
1467{
1468 struct uart_state *state = tty->driver_data;
1469 struct uart_port *uport;
1470
1471 mutex_lock(&state->port.mutex);
1472 uport = uart_port_check(state);
1473 if (uport && uport->ops->set_ldisc)
1474 uport->ops->set_ldisc(uport, &tty->termios);
1475 mutex_unlock(&state->port.mutex);
1476}
1477
1478static void uart_set_termios(struct tty_struct *tty,
1479 struct ktermios *old_termios)
1480{
1481 struct uart_state *state = tty->driver_data;
1482 struct uart_port *uport;
1483 unsigned int cflag = tty->termios.c_cflag;
1484 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1485 bool sw_changed = false;
1486
1487 mutex_lock(&state->port.mutex);
1488 uport = uart_port_check(state);
1489 if (!uport)
1490 goto out;
1491
1492 /*
1493 * Drivers doing software flow control also need to know
1494 * about changes to these input settings.
1495 */
1496 if (uport->flags & UPF_SOFT_FLOW) {
1497 iflag_mask |= IXANY|IXON|IXOFF;
1498 sw_changed =
1499 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1500 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1501 }
1502
1503 /*
1504 * These are the bits that are used to setup various
1505 * flags in the low level driver. We can ignore the Bfoo
1506 * bits in c_cflag; c_[io]speed will always be set
1507 * appropriately by set_termios() in tty_ioctl.c
1508 */
1509 if ((cflag ^ old_termios->c_cflag) == 0 &&
1510 tty->termios.c_ospeed == old_termios->c_ospeed &&
1511 tty->termios.c_ispeed == old_termios->c_ispeed &&
1512 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1513 !sw_changed) {
1514 goto out;
1515 }
1516
1517 uart_change_speed(tty, state, old_termios);
1518 /* reload cflag from termios; port driver may have overridden flags */
1519 cflag = tty->termios.c_cflag;
1520
1521 /* Handle transition to B0 status */
1522 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1523 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1524 /* Handle transition away from B0 status */
1525 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1526 unsigned int mask = TIOCM_DTR;
1527
1528 if (!(cflag & CRTSCTS) || !tty_throttled(tty))
1529 mask |= TIOCM_RTS;
1530 uart_set_mctrl(uport, mask);
1531 }
1532out:
1533 mutex_unlock(&state->port.mutex);
1534}
1535
1536/*
1537 * Calls to uart_close() are serialised via the tty_lock in
1538 * drivers/tty/tty_io.c:tty_release()
1539 * drivers/tty/tty_io.c:do_tty_hangup()
1540 */
1541static void uart_close(struct tty_struct *tty, struct file *filp)
1542{
1543 struct uart_state *state = tty->driver_data;
1544
1545 if (!state) {
1546 struct uart_driver *drv = tty->driver->driver_state;
1547 struct tty_port *port;
1548
1549 state = drv->state + tty->index;
1550 port = &state->port;
1551 spin_lock_irq(&port->lock);
1552 --port->count;
1553 spin_unlock_irq(&port->lock);
1554 return;
1555 }
1556
1557 pr_debug("uart_close(%d) called\n", tty->index);
1558
1559 tty_port_close(tty->port, tty, filp);
1560}
1561
1562static void uart_tty_port_shutdown(struct tty_port *port)
1563{
1564 struct uart_state *state = container_of(port, struct uart_state, port);
1565 struct uart_port *uport = uart_port_check(state);
1566
1567 /*
1568 * At this point, we stop accepting input. To do this, we
1569 * disable the receive line status interrupts.
1570 */
1571 if (WARN(!uport, "detached port still initialized!\n"))
1572 return;
1573
1574 spin_lock_irq(&uport->lock);
1575 uport->ops->stop_rx(uport);
1576 spin_unlock_irq(&uport->lock);
1577
1578 uart_port_shutdown(port);
1579
1580 /*
1581 * It's possible for shutdown to be called after suspend if we get
1582 * a DCD drop (hangup) at just the right time. Clear suspended bit so
1583 * we don't try to resume a port that has been shutdown.
1584 */
1585 tty_port_set_suspended(port, 0);
1586
1587 uart_change_pm(state, UART_PM_STATE_OFF);
1588
1589}
1590
1591static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1592{
1593 struct uart_state *state = tty->driver_data;
1594 struct uart_port *port;
1595 unsigned long char_time, expire;
1596
1597 port = uart_port_ref(state);
1598 if (!port)
1599 return;
1600
1601 if (port->type == PORT_UNKNOWN || port->fifosize == 0) {
1602 uart_port_deref(port);
1603 return;
1604 }
1605
1606 /*
1607 * Set the check interval to be 1/5 of the estimated time to
1608 * send a single character, and make it at least 1. The check
1609 * interval should also be less than the timeout.
1610 *
1611 * Note: we have to use pretty tight timings here to satisfy
1612 * the NIST-PCTS.
1613 */
1614 char_time = (port->timeout - HZ/50) / port->fifosize;
1615 char_time = char_time / 5;
1616 if (char_time == 0)
1617 char_time = 1;
1618 if (timeout && timeout < char_time)
1619 char_time = timeout;
1620
1621 /*
1622 * If the transmitter hasn't cleared in twice the approximate
1623 * amount of time to send the entire FIFO, it probably won't
1624 * ever clear. This assumes the UART isn't doing flow
1625 * control, which is currently the case. Hence, if it ever
1626 * takes longer than port->timeout, this is probably due to a
1627 * UART bug of some kind. So, we clamp the timeout parameter at
1628 * 2*port->timeout.
1629 */
1630 if (timeout == 0 || timeout > 2 * port->timeout)
1631 timeout = 2 * port->timeout;
1632
1633 expire = jiffies + timeout;
1634
1635 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1636 port->line, jiffies, expire);
1637
1638 /*
1639 * Check whether the transmitter is empty every 'char_time'.
1640 * 'timeout' / 'expire' give us the maximum amount of time
1641 * we wait.
1642 */
1643 while (!port->ops->tx_empty(port)) {
1644 msleep_interruptible(jiffies_to_msecs(char_time));
1645 if (signal_pending(current))
1646 break;
1647 if (time_after(jiffies, expire))
1648 break;
1649 }
1650 uart_port_deref(port);
1651}
1652
1653/*
1654 * Calls to uart_hangup() are serialised by the tty_lock in
1655 * drivers/tty/tty_io.c:do_tty_hangup()
1656 * This runs from a workqueue and can sleep for a _short_ time only.
1657 */
1658static void uart_hangup(struct tty_struct *tty)
1659{
1660 struct uart_state *state = tty->driver_data;
1661 struct tty_port *port = &state->port;
1662 struct uart_port *uport;
1663 unsigned long flags;
1664
1665 pr_debug("uart_hangup(%d)\n", tty->index);
1666
1667 mutex_lock(&port->mutex);
1668 uport = uart_port_check(state);
1669 WARN(!uport, "hangup of detached port!\n");
1670
1671 if (tty_port_active(port)) {
1672 uart_flush_buffer(tty);
1673 uart_shutdown(tty, state);
1674 spin_lock_irqsave(&port->lock, flags);
1675 port->count = 0;
1676 spin_unlock_irqrestore(&port->lock, flags);
1677 tty_port_set_active(port, 0);
1678 tty_port_tty_set(port, NULL);
1679 if (uport && !uart_console(uport))
1680 uart_change_pm(state, UART_PM_STATE_OFF);
1681 wake_up_interruptible(&port->open_wait);
1682 wake_up_interruptible(&port->delta_msr_wait);
1683 }
1684 mutex_unlock(&port->mutex);
1685}
1686
1687/* uport == NULL if uart_port has already been removed */
1688static void uart_port_shutdown(struct tty_port *port)
1689{
1690 struct uart_state *state = container_of(port, struct uart_state, port);
1691 struct uart_port *uport = uart_port_check(state);
1692
1693 /*
1694 * clear delta_msr_wait queue to avoid mem leaks: we may free
1695 * the irq here so the queue might never be woken up. Note
1696 * that we won't end up waiting on delta_msr_wait again since
1697 * any outstanding file descriptors should be pointing at
1698 * hung_up_tty_fops now.
1699 */
1700 wake_up_interruptible(&port->delta_msr_wait);
1701
1702 /*
1703 * Free the IRQ and disable the port.
1704 */
1705 if (uport)
1706 uport->ops->shutdown(uport);
1707
1708 /*
1709 * Ensure that the IRQ handler isn't running on another CPU.
1710 */
1711 if (uport)
1712 synchronize_irq(uport->irq);
1713}
1714
1715static int uart_carrier_raised(struct tty_port *port)
1716{
1717 struct uart_state *state = container_of(port, struct uart_state, port);
1718 struct uart_port *uport;
1719 int mctrl;
1720
1721 uport = uart_port_ref(state);
1722 /*
1723 * Should never observe uport == NULL since checks for hangup should
1724 * abort the tty_port_block_til_ready() loop before checking for carrier
1725 * raised -- but report carrier raised if it does anyway so open will
1726 * continue and not sleep
1727 */
1728 if (WARN_ON(!uport))
1729 return 1;
1730 spin_lock_irq(&uport->lock);
1731 uart_enable_ms(uport);
1732 mctrl = uport->ops->get_mctrl(uport);
1733 spin_unlock_irq(&uport->lock);
1734 uart_port_deref(uport);
1735 if (mctrl & TIOCM_CAR)
1736 return 1;
1737 return 0;
1738}
1739
1740static void uart_dtr_rts(struct tty_port *port, int raise)
1741{
1742 struct uart_state *state = container_of(port, struct uart_state, port);
1743 struct uart_port *uport;
1744
1745 uport = uart_port_ref(state);
1746 if (!uport)
1747 return;
1748 uart_port_dtr_rts(uport, raise);
1749 uart_port_deref(uport);
1750}
1751
1752static int uart_install(struct tty_driver *driver, struct tty_struct *tty)
1753{
1754 struct uart_driver *drv = driver->driver_state;
1755 struct uart_state *state = drv->state + tty->index;
1756
1757 tty->driver_data = state;
1758
1759 return tty_standard_install(driver, tty);
1760}
1761
1762/*
1763 * Calls to uart_open are serialised by the tty_lock in
1764 * drivers/tty/tty_io.c:tty_open()
1765 * Note that if this fails, then uart_close() _will_ be called.
1766 *
1767 * In time, we want to scrap the "opening nonpresent ports"
1768 * behaviour and implement an alternative way for setserial
1769 * to set base addresses/ports/types. This will allow us to
1770 * get rid of a certain amount of extra tests.
1771 */
1772static int uart_open(struct tty_struct *tty, struct file *filp)
1773{
1774 struct uart_state *state = tty->driver_data;
1775 int retval;
1776
1777 retval = tty_port_open(&state->port, tty, filp);
1778 if (retval > 0)
1779 retval = 0;
1780
1781 return retval;
1782}
1783
1784static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1785{
1786 struct uart_state *state = container_of(port, struct uart_state, port);
1787 struct uart_port *uport;
1788 int ret;
1789
1790 uport = uart_port_check(state);
1791 if (!uport || uport->flags & UPF_DEAD)
1792 return -ENXIO;
1793
1794 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
1795
1796 /*
1797 * Start up the serial port.
1798 */
1799 ret = uart_startup(tty, state, 0);
1800 if (ret > 0)
1801 tty_port_set_active(port, 1);
1802
1803 return ret;
1804}
1805
1806static const char *uart_type(struct uart_port *port)
1807{
1808 const char *str = NULL;
1809
1810 if (port->ops->type)
1811 str = port->ops->type(port);
1812
1813 if (!str)
1814 str = "unknown";
1815
1816 return str;
1817}
1818
1819#ifdef CONFIG_PROC_FS
1820
1821static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1822{
1823 struct uart_state *state = drv->state + i;
1824 struct tty_port *port = &state->port;
1825 enum uart_pm_state pm_state;
1826 struct uart_port *uport;
1827 char stat_buf[32];
1828 unsigned int status;
1829 int mmio;
1830
1831 mutex_lock(&port->mutex);
1832 uport = uart_port_check(state);
1833 if (!uport)
1834 goto out;
1835
1836 mmio = uport->iotype >= UPIO_MEM;
1837 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1838 uport->line, uart_type(uport),
1839 mmio ? "mmio:0x" : "port:",
1840 mmio ? (unsigned long long)uport->mapbase
1841 : (unsigned long long)uport->iobase,
1842 uport->irq);
1843
1844 if (uport->type == PORT_UNKNOWN) {
1845 seq_putc(m, '\n');
1846 goto out;
1847 }
1848
1849 if (capable(CAP_SYS_ADMIN)) {
1850 pm_state = state->pm_state;
1851 if (pm_state != UART_PM_STATE_ON)
1852 uart_change_pm(state, UART_PM_STATE_ON);
1853 spin_lock_irq(&uport->lock);
1854 status = uport->ops->get_mctrl(uport);
1855 spin_unlock_irq(&uport->lock);
1856 if (pm_state != UART_PM_STATE_ON)
1857 uart_change_pm(state, pm_state);
1858
1859 seq_printf(m, " tx:%d rx:%d",
1860 uport->icount.tx, uport->icount.rx);
1861 if (uport->icount.frame)
1862 seq_printf(m, " fe:%d", uport->icount.frame);
1863 if (uport->icount.parity)
1864 seq_printf(m, " pe:%d", uport->icount.parity);
1865 if (uport->icount.brk)
1866 seq_printf(m, " brk:%d", uport->icount.brk);
1867 if (uport->icount.overrun)
1868 seq_printf(m, " oe:%d", uport->icount.overrun);
1869 if (uport->icount.buf_overrun)
1870 seq_printf(m, " bo:%d", uport->icount.buf_overrun);
1871
1872#define INFOBIT(bit, str) \
1873 if (uport->mctrl & (bit)) \
1874 strncat(stat_buf, (str), sizeof(stat_buf) - \
1875 strlen(stat_buf) - 2)
1876#define STATBIT(bit, str) \
1877 if (status & (bit)) \
1878 strncat(stat_buf, (str), sizeof(stat_buf) - \
1879 strlen(stat_buf) - 2)
1880
1881 stat_buf[0] = '\0';
1882 stat_buf[1] = '\0';
1883 INFOBIT(TIOCM_RTS, "|RTS");
1884 STATBIT(TIOCM_CTS, "|CTS");
1885 INFOBIT(TIOCM_DTR, "|DTR");
1886 STATBIT(TIOCM_DSR, "|DSR");
1887 STATBIT(TIOCM_CAR, "|CD");
1888 STATBIT(TIOCM_RNG, "|RI");
1889 if (stat_buf[0])
1890 stat_buf[0] = ' ';
1891
1892 seq_puts(m, stat_buf);
1893 }
1894 seq_putc(m, '\n');
1895#undef STATBIT
1896#undef INFOBIT
1897out:
1898 mutex_unlock(&port->mutex);
1899}
1900
1901static int uart_proc_show(struct seq_file *m, void *v)
1902{
1903 struct tty_driver *ttydrv = m->private;
1904 struct uart_driver *drv = ttydrv->driver_state;
1905 int i;
1906
1907 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
1908 for (i = 0; i < drv->nr; i++)
1909 uart_line_info(m, drv, i);
1910 return 0;
1911}
1912#endif
1913
1914static inline bool uart_console_enabled(struct uart_port *port)
1915{
1916 return uart_console(port) && (port->cons->flags & CON_ENABLED);
1917}
1918
1919static void uart_port_spin_lock_init(struct uart_port *port)
1920{
1921 spin_lock_init(&port->lock);
1922 lockdep_set_class(&port->lock, &port_lock_key);
1923}
1924
1925#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1926/**
1927 * uart_console_write - write a console message to a serial port
1928 * @port: the port to write the message
1929 * @s: array of characters
1930 * @count: number of characters in string to write
1931 * @putchar: function to write character to port
1932 */
1933void uart_console_write(struct uart_port *port, const char *s,
1934 unsigned int count,
1935 void (*putchar)(struct uart_port *, int))
1936{
1937 unsigned int i;
1938
1939 for (i = 0; i < count; i++, s++) {
1940 if (*s == '\n')
1941 putchar(port, '\r');
1942 putchar(port, *s);
1943 }
1944}
1945EXPORT_SYMBOL_GPL(uart_console_write);
1946
1947/*
1948 * Check whether an invalid uart number has been specified, and
1949 * if so, search for the first available port that does have
1950 * console support.
1951 */
1952struct uart_port * __init
1953uart_get_console(struct uart_port *ports, int nr, struct console *co)
1954{
1955 int idx = co->index;
1956
1957 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1958 ports[idx].membase == NULL))
1959 for (idx = 0; idx < nr; idx++)
1960 if (ports[idx].iobase != 0 ||
1961 ports[idx].membase != NULL)
1962 break;
1963
1964 co->index = idx;
1965
1966 return ports + idx;
1967}
1968
1969/**
1970 * uart_parse_earlycon - Parse earlycon options
1971 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1972 * @iotype: ptr for decoded iotype (out)
1973 * @addr: ptr for decoded mapbase/iobase (out)
1974 * @options: ptr for <options> field; NULL if not present (out)
1975 *
1976 * Decodes earlycon kernel command line parameters of the form
1977 * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1978 * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1979 *
1980 * The optional form
1981 *
1982 * earlycon=<name>,0x<addr>,<options>
1983 * console=<name>,0x<addr>,<options>
1984 *
1985 * is also accepted; the returned @iotype will be UPIO_MEM.
1986 *
1987 * Returns 0 on success or -EINVAL on failure
1988 */
1989int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
1990 char **options)
1991{
1992 if (strncmp(p, "mmio,", 5) == 0) {
1993 *iotype = UPIO_MEM;
1994 p += 5;
1995 } else if (strncmp(p, "mmio16,", 7) == 0) {
1996 *iotype = UPIO_MEM16;
1997 p += 7;
1998 } else if (strncmp(p, "mmio32,", 7) == 0) {
1999 *iotype = UPIO_MEM32;
2000 p += 7;
2001 } else if (strncmp(p, "mmio32be,", 9) == 0) {
2002 *iotype = UPIO_MEM32BE;
2003 p += 9;
2004 } else if (strncmp(p, "mmio32native,", 13) == 0) {
2005 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
2006 UPIO_MEM32BE : UPIO_MEM32;
2007 p += 13;
2008 } else if (strncmp(p, "io,", 3) == 0) {
2009 *iotype = UPIO_PORT;
2010 p += 3;
2011 } else if (strncmp(p, "0x", 2) == 0) {
2012 *iotype = UPIO_MEM;
2013 } else {
2014 return -EINVAL;
2015 }
2016
2017 /*
2018 * Before you replace it with kstrtoull(), think about options separator
2019 * (',') it will not tolerate
2020 */
2021 *addr = simple_strtoull(p, NULL, 0);
2022 p = strchr(p, ',');
2023 if (p)
2024 p++;
2025
2026 *options = p;
2027 return 0;
2028}
2029EXPORT_SYMBOL_GPL(uart_parse_earlycon);
2030
2031/**
2032 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
2033 * @options: pointer to option string
2034 * @baud: pointer to an 'int' variable for the baud rate.
2035 * @parity: pointer to an 'int' variable for the parity.
2036 * @bits: pointer to an 'int' variable for the number of data bits.
2037 * @flow: pointer to an 'int' variable for the flow control character.
2038 *
2039 * uart_parse_options decodes a string containing the serial console
2040 * options. The format of the string is <baud><parity><bits><flow>,
2041 * eg: 115200n8r
2042 */
2043void
2044uart_parse_options(const char *options, int *baud, int *parity,
2045 int *bits, int *flow)
2046{
2047 const char *s = options;
2048
2049 *baud = simple_strtoul(s, NULL, 10);
2050 while (*s >= '0' && *s <= '9')
2051 s++;
2052 if (*s)
2053 *parity = *s++;
2054 if (*s)
2055 *bits = *s++ - '0';
2056 if (*s)
2057 *flow = *s;
2058}
2059EXPORT_SYMBOL_GPL(uart_parse_options);
2060
2061/**
2062 * uart_set_options - setup the serial console parameters
2063 * @port: pointer to the serial ports uart_port structure
2064 * @co: console pointer
2065 * @baud: baud rate
2066 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
2067 * @bits: number of data bits
2068 * @flow: flow control character - 'r' (rts)
2069 */
2070int
2071uart_set_options(struct uart_port *port, struct console *co,
2072 int baud, int parity, int bits, int flow)
2073{
2074 struct ktermios termios;
2075 static struct ktermios dummy;
2076
2077 /*
2078 * Ensure that the serial-console lock is initialised early.
2079 *
2080 * Note that the console-enabled check is needed because of kgdboc,
2081 * which can end up calling uart_set_options() for an already enabled
2082 * console via tty_find_polling_driver() and uart_poll_init().
2083 */
2084 if (!uart_console_enabled(port) && !port->console_reinit)
2085 uart_port_spin_lock_init(port);
2086
2087 memset(&termios, 0, sizeof(struct ktermios));
2088
2089 termios.c_cflag |= CREAD | HUPCL | CLOCAL;
2090 tty_termios_encode_baud_rate(&termios, baud, baud);
2091
2092 if (bits == 7)
2093 termios.c_cflag |= CS7;
2094 else
2095 termios.c_cflag |= CS8;
2096
2097 switch (parity) {
2098 case 'o': case 'O':
2099 termios.c_cflag |= PARODD;
2100 fallthrough;
2101 case 'e': case 'E':
2102 termios.c_cflag |= PARENB;
2103 break;
2104 }
2105
2106 if (flow == 'r')
2107 termios.c_cflag |= CRTSCTS;
2108
2109 /*
2110 * some uarts on other side don't support no flow control.
2111 * So we set * DTR in host uart to make them happy
2112 */
2113 port->mctrl |= TIOCM_DTR;
2114
2115 port->ops->set_termios(port, &termios, &dummy);
2116 /*
2117 * Allow the setting of the UART parameters with a NULL console
2118 * too:
2119 */
2120 if (co)
2121 co->cflag = termios.c_cflag;
2122
2123 return 0;
2124}
2125EXPORT_SYMBOL_GPL(uart_set_options);
2126#endif /* CONFIG_SERIAL_CORE_CONSOLE */
2127
2128/**
2129 * uart_change_pm - set power state of the port
2130 *
2131 * @state: port descriptor
2132 * @pm_state: new state
2133 *
2134 * Locking: port->mutex has to be held
2135 */
2136static void uart_change_pm(struct uart_state *state,
2137 enum uart_pm_state pm_state)
2138{
2139 struct uart_port *port = uart_port_check(state);
2140
2141 if (state->pm_state != pm_state) {
2142 if (port && port->ops->pm)
2143 port->ops->pm(port, pm_state, state->pm_state);
2144 state->pm_state = pm_state;
2145 }
2146}
2147
2148struct uart_match {
2149 struct uart_port *port;
2150 struct uart_driver *driver;
2151};
2152
2153static int serial_match_port(struct device *dev, void *data)
2154{
2155 struct uart_match *match = data;
2156 struct tty_driver *tty_drv = match->driver->tty_driver;
2157 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
2158 match->port->line;
2159
2160 return dev->devt == devt; /* Actually, only one tty per port */
2161}
2162
2163int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
2164{
2165 struct uart_state *state = drv->state + uport->line;
2166 struct tty_port *port = &state->port;
2167 struct device *tty_dev;
2168 struct uart_match match = {uport, drv};
2169
2170 mutex_lock(&port->mutex);
2171
2172 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2173 if (tty_dev && device_may_wakeup(tty_dev)) {
2174 enable_irq_wake(uport->irq);
2175 put_device(tty_dev);
2176 mutex_unlock(&port->mutex);
2177 return 0;
2178 }
2179 put_device(tty_dev);
2180
2181 /* Nothing to do if the console is not suspending */
2182 if (!console_suspend_enabled && uart_console(uport))
2183 goto unlock;
2184
2185 uport->suspended = 1;
2186
2187 if (tty_port_initialized(port)) {
2188 const struct uart_ops *ops = uport->ops;
2189 int tries;
2190
2191 tty_port_set_suspended(port, 1);
2192 tty_port_set_initialized(port, 0);
2193
2194 spin_lock_irq(&uport->lock);
2195 ops->stop_tx(uport);
2196 ops->set_mctrl(uport, 0);
2197 ops->stop_rx(uport);
2198 spin_unlock_irq(&uport->lock);
2199
2200 /*
2201 * Wait for the transmitter to empty.
2202 */
2203 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2204 msleep(10);
2205 if (!tries)
2206 dev_err(uport->dev, "%s: Unable to drain transmitter\n",
2207 uport->name);
2208
2209 ops->shutdown(uport);
2210 }
2211
2212 /*
2213 * Disable the console device before suspending.
2214 */
2215 if (uart_console(uport))
2216 console_stop(uport->cons);
2217
2218 uart_change_pm(state, UART_PM_STATE_OFF);
2219unlock:
2220 mutex_unlock(&port->mutex);
2221
2222 return 0;
2223}
2224
2225int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2226{
2227 struct uart_state *state = drv->state + uport->line;
2228 struct tty_port *port = &state->port;
2229 struct device *tty_dev;
2230 struct uart_match match = {uport, drv};
2231 struct ktermios termios;
2232
2233 mutex_lock(&port->mutex);
2234
2235 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2236 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2237 if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq))))
2238 disable_irq_wake(uport->irq);
2239 put_device(tty_dev);
2240 mutex_unlock(&port->mutex);
2241 return 0;
2242 }
2243 put_device(tty_dev);
2244 uport->suspended = 0;
2245
2246 /*
2247 * Re-enable the console device after suspending.
2248 */
2249 if (uart_console(uport)) {
2250 /*
2251 * First try to use the console cflag setting.
2252 */
2253 memset(&termios, 0, sizeof(struct ktermios));
2254 termios.c_cflag = uport->cons->cflag;
2255
2256 /*
2257 * If that's unset, use the tty termios setting.
2258 */
2259 if (port->tty && termios.c_cflag == 0)
2260 termios = port->tty->termios;
2261
2262 if (console_suspend_enabled)
2263 uart_change_pm(state, UART_PM_STATE_ON);
2264 uport->ops->set_termios(uport, &termios, NULL);
2265 if (console_suspend_enabled)
2266 console_start(uport->cons);
2267 }
2268
2269 if (tty_port_suspended(port)) {
2270 const struct uart_ops *ops = uport->ops;
2271 int ret;
2272
2273 uart_change_pm(state, UART_PM_STATE_ON);
2274 spin_lock_irq(&uport->lock);
2275 ops->set_mctrl(uport, 0);
2276 spin_unlock_irq(&uport->lock);
2277 if (console_suspend_enabled || !uart_console(uport)) {
2278 /* Protected by port mutex for now */
2279 struct tty_struct *tty = port->tty;
2280
2281 ret = ops->startup(uport);
2282 if (ret == 0) {
2283 if (tty)
2284 uart_change_speed(tty, state, NULL);
2285 spin_lock_irq(&uport->lock);
2286 ops->set_mctrl(uport, uport->mctrl);
2287 ops->start_tx(uport);
2288 spin_unlock_irq(&uport->lock);
2289 tty_port_set_initialized(port, 1);
2290 } else {
2291 /*
2292 * Failed to resume - maybe hardware went away?
2293 * Clear the "initialized" flag so we won't try
2294 * to call the low level drivers shutdown method.
2295 */
2296 uart_shutdown(tty, state);
2297 }
2298 }
2299
2300 tty_port_set_suspended(port, 0);
2301 }
2302
2303 mutex_unlock(&port->mutex);
2304
2305 return 0;
2306}
2307
2308static inline void
2309uart_report_port(struct uart_driver *drv, struct uart_port *port)
2310{
2311 char address[64];
2312
2313 switch (port->iotype) {
2314 case UPIO_PORT:
2315 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2316 break;
2317 case UPIO_HUB6:
2318 snprintf(address, sizeof(address),
2319 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2320 break;
2321 case UPIO_MEM:
2322 case UPIO_MEM16:
2323 case UPIO_MEM32:
2324 case UPIO_MEM32BE:
2325 case UPIO_AU:
2326 case UPIO_TSI:
2327 snprintf(address, sizeof(address),
2328 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2329 break;
2330 default:
2331 strlcpy(address, "*unknown*", sizeof(address));
2332 break;
2333 }
2334
2335 pr_info("%s%s%s at %s (irq = %d, base_baud = %d) is a %s\n",
2336 port->dev ? dev_name(port->dev) : "",
2337 port->dev ? ": " : "",
2338 port->name,
2339 address, port->irq, port->uartclk / 16, uart_type(port));
2340}
2341
2342static void
2343uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2344 struct uart_port *port)
2345{
2346 unsigned int flags;
2347
2348 /*
2349 * If there isn't a port here, don't do anything further.
2350 */
2351 if (!port->iobase && !port->mapbase && !port->membase)
2352 return;
2353
2354 /*
2355 * Now do the auto configuration stuff. Note that config_port
2356 * is expected to claim the resources and map the port for us.
2357 */
2358 flags = 0;
2359 if (port->flags & UPF_AUTO_IRQ)
2360 flags |= UART_CONFIG_IRQ;
2361 if (port->flags & UPF_BOOT_AUTOCONF) {
2362 if (!(port->flags & UPF_FIXED_TYPE)) {
2363 port->type = PORT_UNKNOWN;
2364 flags |= UART_CONFIG_TYPE;
2365 }
2366 port->ops->config_port(port, flags);
2367 }
2368
2369 if (port->type != PORT_UNKNOWN) {
2370 unsigned long flags;
2371
2372 uart_report_port(drv, port);
2373
2374 /* Power up port for set_mctrl() */
2375 uart_change_pm(state, UART_PM_STATE_ON);
2376
2377 /*
2378 * Ensure that the modem control lines are de-activated.
2379 * keep the DTR setting that is set in uart_set_options()
2380 * We probably don't need a spinlock around this, but
2381 */
2382 spin_lock_irqsave(&port->lock, flags);
2383 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2384 spin_unlock_irqrestore(&port->lock, flags);
2385
2386 /*
2387 * If this driver supports console, and it hasn't been
2388 * successfully registered yet, try to re-register it.
2389 * It may be that the port was not available.
2390 */
2391 if (port->cons && !(port->cons->flags & CON_ENABLED))
2392 register_console(port->cons);
2393
2394 /*
2395 * Power down all ports by default, except the
2396 * console if we have one.
2397 */
2398 if (!uart_console(port))
2399 uart_change_pm(state, UART_PM_STATE_OFF);
2400 }
2401}
2402
2403#ifdef CONFIG_CONSOLE_POLL
2404
2405static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2406{
2407 struct uart_driver *drv = driver->driver_state;
2408 struct uart_state *state = drv->state + line;
2409 struct tty_port *tport;
2410 struct uart_port *port;
2411 int baud = 9600;
2412 int bits = 8;
2413 int parity = 'n';
2414 int flow = 'n';
2415 int ret = 0;
2416
2417 tport = &state->port;
2418 mutex_lock(&tport->mutex);
2419
2420 port = uart_port_check(state);
2421 if (!port || !(port->ops->poll_get_char && port->ops->poll_put_char)) {
2422 ret = -1;
2423 goto out;
2424 }
2425
2426 if (port->ops->poll_init) {
2427 /*
2428 * We don't set initialized as we only initialized the hw,
2429 * e.g. state->xmit is still uninitialized.
2430 */
2431 if (!tty_port_initialized(tport))
2432 ret = port->ops->poll_init(port);
2433 }
2434
2435 if (!ret && options) {
2436 uart_parse_options(options, &baud, &parity, &bits, &flow);
2437 ret = uart_set_options(port, NULL, baud, parity, bits, flow);
2438 }
2439out:
2440 mutex_unlock(&tport->mutex);
2441 return ret;
2442}
2443
2444static int uart_poll_get_char(struct tty_driver *driver, int line)
2445{
2446 struct uart_driver *drv = driver->driver_state;
2447 struct uart_state *state = drv->state + line;
2448 struct uart_port *port;
2449 int ret = -1;
2450
2451 port = uart_port_ref(state);
2452 if (port) {
2453 ret = port->ops->poll_get_char(port);
2454 uart_port_deref(port);
2455 }
2456
2457 return ret;
2458}
2459
2460static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2461{
2462 struct uart_driver *drv = driver->driver_state;
2463 struct uart_state *state = drv->state + line;
2464 struct uart_port *port;
2465
2466 port = uart_port_ref(state);
2467 if (!port)
2468 return;
2469
2470 if (ch == '\n')
2471 port->ops->poll_put_char(port, '\r');
2472 port->ops->poll_put_char(port, ch);
2473 uart_port_deref(port);
2474}
2475#endif
2476
2477static const struct tty_operations uart_ops = {
2478 .install = uart_install,
2479 .open = uart_open,
2480 .close = uart_close,
2481 .write = uart_write,
2482 .put_char = uart_put_char,
2483 .flush_chars = uart_flush_chars,
2484 .write_room = uart_write_room,
2485 .chars_in_buffer= uart_chars_in_buffer,
2486 .flush_buffer = uart_flush_buffer,
2487 .ioctl = uart_ioctl,
2488 .throttle = uart_throttle,
2489 .unthrottle = uart_unthrottle,
2490 .send_xchar = uart_send_xchar,
2491 .set_termios = uart_set_termios,
2492 .set_ldisc = uart_set_ldisc,
2493 .stop = uart_stop,
2494 .start = uart_start,
2495 .hangup = uart_hangup,
2496 .break_ctl = uart_break_ctl,
2497 .wait_until_sent= uart_wait_until_sent,
2498#ifdef CONFIG_PROC_FS
2499 .proc_show = uart_proc_show,
2500#endif
2501 .tiocmget = uart_tiocmget,
2502 .tiocmset = uart_tiocmset,
2503 .set_serial = uart_set_info_user,
2504 .get_serial = uart_get_info_user,
2505 .get_icount = uart_get_icount,
2506#ifdef CONFIG_CONSOLE_POLL
2507 .poll_init = uart_poll_init,
2508 .poll_get_char = uart_poll_get_char,
2509 .poll_put_char = uart_poll_put_char,
2510#endif
2511};
2512
2513static const struct tty_port_operations uart_port_ops = {
2514 .carrier_raised = uart_carrier_raised,
2515 .dtr_rts = uart_dtr_rts,
2516 .activate = uart_port_activate,
2517 .shutdown = uart_tty_port_shutdown,
2518};
2519
2520/**
2521 * uart_register_driver - register a driver with the uart core layer
2522 * @drv: low level driver structure
2523 *
2524 * Register a uart driver with the core driver. We in turn register
2525 * with the tty layer, and initialise the core driver per-port state.
2526 *
2527 * We have a proc file in /proc/tty/driver which is named after the
2528 * normal driver.
2529 *
2530 * drv->port should be NULL, and the per-port structures should be
2531 * registered using uart_add_one_port after this call has succeeded.
2532 */
2533int uart_register_driver(struct uart_driver *drv)
2534{
2535 struct tty_driver *normal;
2536 int i, retval = -ENOMEM;
2537
2538 BUG_ON(drv->state);
2539
2540 /*
2541 * Maybe we should be using a slab cache for this, especially if
2542 * we have a large number of ports to handle.
2543 */
2544 drv->state = kcalloc(drv->nr, sizeof(struct uart_state), GFP_KERNEL);
2545 if (!drv->state)
2546 goto out;
2547
2548 normal = alloc_tty_driver(drv->nr);
2549 if (!normal)
2550 goto out_kfree;
2551
2552 drv->tty_driver = normal;
2553
2554 normal->driver_name = drv->driver_name;
2555 normal->name = drv->dev_name;
2556 normal->major = drv->major;
2557 normal->minor_start = drv->minor;
2558 normal->type = TTY_DRIVER_TYPE_SERIAL;
2559 normal->subtype = SERIAL_TYPE_NORMAL;
2560 normal->init_termios = tty_std_termios;
2561 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2562 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2563 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2564 normal->driver_state = drv;
2565 tty_set_operations(normal, &uart_ops);
2566
2567 /*
2568 * Initialise the UART state(s).
2569 */
2570 for (i = 0; i < drv->nr; i++) {
2571 struct uart_state *state = drv->state + i;
2572 struct tty_port *port = &state->port;
2573
2574 tty_port_init(port);
2575 port->ops = &uart_port_ops;
2576 }
2577
2578 retval = tty_register_driver(normal);
2579 if (retval >= 0)
2580 return retval;
2581
2582 for (i = 0; i < drv->nr; i++)
2583 tty_port_destroy(&drv->state[i].port);
2584 put_tty_driver(normal);
2585out_kfree:
2586 kfree(drv->state);
2587out:
2588 return retval;
2589}
2590
2591/**
2592 * uart_unregister_driver - remove a driver from the uart core layer
2593 * @drv: low level driver structure
2594 *
2595 * Remove all references to a driver from the core driver. The low
2596 * level driver must have removed all its ports via the
2597 * uart_remove_one_port() if it registered them with uart_add_one_port().
2598 * (ie, drv->port == NULL)
2599 */
2600void uart_unregister_driver(struct uart_driver *drv)
2601{
2602 struct tty_driver *p = drv->tty_driver;
2603 unsigned int i;
2604
2605 tty_unregister_driver(p);
2606 put_tty_driver(p);
2607 for (i = 0; i < drv->nr; i++)
2608 tty_port_destroy(&drv->state[i].port);
2609 kfree(drv->state);
2610 drv->state = NULL;
2611 drv->tty_driver = NULL;
2612}
2613
2614struct tty_driver *uart_console_device(struct console *co, int *index)
2615{
2616 struct uart_driver *p = co->data;
2617 *index = co->index;
2618 return p->tty_driver;
2619}
2620EXPORT_SYMBOL_GPL(uart_console_device);
2621
2622static ssize_t uartclk_show(struct device *dev,
2623 struct device_attribute *attr, char *buf)
2624{
2625 struct serial_struct tmp;
2626 struct tty_port *port = dev_get_drvdata(dev);
2627
2628 uart_get_info(port, &tmp);
2629 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2630}
2631
2632static ssize_t type_show(struct device *dev,
2633 struct device_attribute *attr, char *buf)
2634{
2635 struct serial_struct tmp;
2636 struct tty_port *port = dev_get_drvdata(dev);
2637
2638 uart_get_info(port, &tmp);
2639 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2640}
2641
2642static ssize_t line_show(struct device *dev,
2643 struct device_attribute *attr, char *buf)
2644{
2645 struct serial_struct tmp;
2646 struct tty_port *port = dev_get_drvdata(dev);
2647
2648 uart_get_info(port, &tmp);
2649 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2650}
2651
2652static ssize_t port_show(struct device *dev,
2653 struct device_attribute *attr, char *buf)
2654{
2655 struct serial_struct tmp;
2656 struct tty_port *port = dev_get_drvdata(dev);
2657 unsigned long ioaddr;
2658
2659 uart_get_info(port, &tmp);
2660 ioaddr = tmp.port;
2661 if (HIGH_BITS_OFFSET)
2662 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2663 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2664}
2665
2666static ssize_t irq_show(struct device *dev,
2667 struct device_attribute *attr, char *buf)
2668{
2669 struct serial_struct tmp;
2670 struct tty_port *port = dev_get_drvdata(dev);
2671
2672 uart_get_info(port, &tmp);
2673 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2674}
2675
2676static ssize_t flags_show(struct device *dev,
2677 struct device_attribute *attr, char *buf)
2678{
2679 struct serial_struct tmp;
2680 struct tty_port *port = dev_get_drvdata(dev);
2681
2682 uart_get_info(port, &tmp);
2683 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2684}
2685
2686static ssize_t xmit_fifo_size_show(struct device *dev,
2687 struct device_attribute *attr, char *buf)
2688{
2689 struct serial_struct tmp;
2690 struct tty_port *port = dev_get_drvdata(dev);
2691
2692 uart_get_info(port, &tmp);
2693 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2694}
2695
2696static ssize_t close_delay_show(struct device *dev,
2697 struct device_attribute *attr, char *buf)
2698{
2699 struct serial_struct tmp;
2700 struct tty_port *port = dev_get_drvdata(dev);
2701
2702 uart_get_info(port, &tmp);
2703 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2704}
2705
2706static ssize_t closing_wait_show(struct device *dev,
2707 struct device_attribute *attr, char *buf)
2708{
2709 struct serial_struct tmp;
2710 struct tty_port *port = dev_get_drvdata(dev);
2711
2712 uart_get_info(port, &tmp);
2713 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2714}
2715
2716static ssize_t custom_divisor_show(struct device *dev,
2717 struct device_attribute *attr, char *buf)
2718{
2719 struct serial_struct tmp;
2720 struct tty_port *port = dev_get_drvdata(dev);
2721
2722 uart_get_info(port, &tmp);
2723 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2724}
2725
2726static ssize_t io_type_show(struct device *dev,
2727 struct device_attribute *attr, char *buf)
2728{
2729 struct serial_struct tmp;
2730 struct tty_port *port = dev_get_drvdata(dev);
2731
2732 uart_get_info(port, &tmp);
2733 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2734}
2735
2736static ssize_t iomem_base_show(struct device *dev,
2737 struct device_attribute *attr, char *buf)
2738{
2739 struct serial_struct tmp;
2740 struct tty_port *port = dev_get_drvdata(dev);
2741
2742 uart_get_info(port, &tmp);
2743 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2744}
2745
2746static ssize_t iomem_reg_shift_show(struct device *dev,
2747 struct device_attribute *attr, char *buf)
2748{
2749 struct serial_struct tmp;
2750 struct tty_port *port = dev_get_drvdata(dev);
2751
2752 uart_get_info(port, &tmp);
2753 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2754}
2755
2756static ssize_t console_show(struct device *dev,
2757 struct device_attribute *attr, char *buf)
2758{
2759 struct tty_port *port = dev_get_drvdata(dev);
2760 struct uart_state *state = container_of(port, struct uart_state, port);
2761 struct uart_port *uport;
2762 bool console = false;
2763
2764 mutex_lock(&port->mutex);
2765 uport = uart_port_check(state);
2766 if (uport)
2767 console = uart_console_enabled(uport);
2768 mutex_unlock(&port->mutex);
2769
2770 return sprintf(buf, "%c\n", console ? 'Y' : 'N');
2771}
2772
2773static ssize_t console_store(struct device *dev,
2774 struct device_attribute *attr, const char *buf, size_t count)
2775{
2776 struct tty_port *port = dev_get_drvdata(dev);
2777 struct uart_state *state = container_of(port, struct uart_state, port);
2778 struct uart_port *uport;
2779 bool oldconsole, newconsole;
2780 int ret;
2781
2782 ret = kstrtobool(buf, &newconsole);
2783 if (ret)
2784 return ret;
2785
2786 mutex_lock(&port->mutex);
2787 uport = uart_port_check(state);
2788 if (uport) {
2789 oldconsole = uart_console_enabled(uport);
2790 if (oldconsole && !newconsole) {
2791 ret = unregister_console(uport->cons);
2792 } else if (!oldconsole && newconsole) {
2793 if (uart_console(uport)) {
2794 uport->console_reinit = 1;
2795 register_console(uport->cons);
2796 } else {
2797 ret = -ENOENT;
2798 }
2799 }
2800 } else {
2801 ret = -ENXIO;
2802 }
2803 mutex_unlock(&port->mutex);
2804
2805 return ret < 0 ? ret : count;
2806}
2807
2808static DEVICE_ATTR_RO(uartclk);
2809static DEVICE_ATTR_RO(type);
2810static DEVICE_ATTR_RO(line);
2811static DEVICE_ATTR_RO(port);
2812static DEVICE_ATTR_RO(irq);
2813static DEVICE_ATTR_RO(flags);
2814static DEVICE_ATTR_RO(xmit_fifo_size);
2815static DEVICE_ATTR_RO(close_delay);
2816static DEVICE_ATTR_RO(closing_wait);
2817static DEVICE_ATTR_RO(custom_divisor);
2818static DEVICE_ATTR_RO(io_type);
2819static DEVICE_ATTR_RO(iomem_base);
2820static DEVICE_ATTR_RO(iomem_reg_shift);
2821static DEVICE_ATTR_RW(console);
2822
2823static struct attribute *tty_dev_attrs[] = {
2824 &dev_attr_uartclk.attr,
2825 &dev_attr_type.attr,
2826 &dev_attr_line.attr,
2827 &dev_attr_port.attr,
2828 &dev_attr_irq.attr,
2829 &dev_attr_flags.attr,
2830 &dev_attr_xmit_fifo_size.attr,
2831 &dev_attr_close_delay.attr,
2832 &dev_attr_closing_wait.attr,
2833 &dev_attr_custom_divisor.attr,
2834 &dev_attr_io_type.attr,
2835 &dev_attr_iomem_base.attr,
2836 &dev_attr_iomem_reg_shift.attr,
2837 &dev_attr_console.attr,
2838 NULL
2839};
2840
2841static const struct attribute_group tty_dev_attr_group = {
2842 .attrs = tty_dev_attrs,
2843};
2844
2845/**
2846 * uart_add_one_port - attach a driver-defined port structure
2847 * @drv: pointer to the uart low level driver structure for this port
2848 * @uport: uart port structure to use for this port.
2849 *
2850 * This allows the driver to register its own uart_port structure
2851 * with the core driver. The main purpose is to allow the low
2852 * level uart drivers to expand uart_port, rather than having yet
2853 * more levels of structures.
2854 */
2855int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2856{
2857 struct uart_state *state;
2858 struct tty_port *port;
2859 int ret = 0;
2860 struct device *tty_dev;
2861 int num_groups;
2862
2863 BUG_ON(in_interrupt());
2864
2865 if (uport->line >= drv->nr)
2866 return -EINVAL;
2867
2868 state = drv->state + uport->line;
2869 port = &state->port;
2870
2871 mutex_lock(&port_mutex);
2872 mutex_lock(&port->mutex);
2873 if (state->uart_port) {
2874 ret = -EINVAL;
2875 goto out;
2876 }
2877
2878 /* Link the port to the driver state table and vice versa */
2879 atomic_set(&state->refcount, 1);
2880 init_waitqueue_head(&state->remove_wait);
2881 state->uart_port = uport;
2882 uport->state = state;
2883
2884 state->pm_state = UART_PM_STATE_UNDEFINED;
2885 uport->cons = drv->cons;
2886 uport->minor = drv->tty_driver->minor_start + uport->line;
2887 uport->name = kasprintf(GFP_KERNEL, "%s%d", drv->dev_name,
2888 drv->tty_driver->name_base + uport->line);
2889 if (!uport->name) {
2890 ret = -ENOMEM;
2891 goto out;
2892 }
2893
2894 /*
2895 * If this port is in use as a console then the spinlock is already
2896 * initialised.
2897 */
2898 if (!uart_console_enabled(uport))
2899 uart_port_spin_lock_init(uport);
2900
2901 if (uport->cons && uport->dev)
2902 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2903
2904 tty_port_link_device(port, drv->tty_driver, uport->line);
2905 uart_configure_port(drv, state, uport);
2906
2907 port->console = uart_console(uport);
2908
2909 num_groups = 2;
2910 if (uport->attr_group)
2911 num_groups++;
2912
2913 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2914 GFP_KERNEL);
2915 if (!uport->tty_groups) {
2916 ret = -ENOMEM;
2917 goto out;
2918 }
2919 uport->tty_groups[0] = &tty_dev_attr_group;
2920 if (uport->attr_group)
2921 uport->tty_groups[1] = uport->attr_group;
2922
2923 /*
2924 * Register the port whether it's detected or not. This allows
2925 * setserial to be used to alter this port's parameters.
2926 */
2927 tty_dev = tty_port_register_device_attr_serdev(port, drv->tty_driver,
2928 uport->line, uport->dev, port, uport->tty_groups);
2929 if (!IS_ERR(tty_dev)) {
2930 device_set_wakeup_capable(tty_dev, 1);
2931 } else {
2932 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2933 uport->line);
2934 }
2935
2936 /*
2937 * Ensure UPF_DEAD is not set.
2938 */
2939 uport->flags &= ~UPF_DEAD;
2940
2941 out:
2942 mutex_unlock(&port->mutex);
2943 mutex_unlock(&port_mutex);
2944
2945 return ret;
2946}
2947
2948/**
2949 * uart_remove_one_port - detach a driver defined port structure
2950 * @drv: pointer to the uart low level driver structure for this port
2951 * @uport: uart port structure for this port
2952 *
2953 * This unhooks (and hangs up) the specified port structure from the
2954 * core driver. No further calls will be made to the low-level code
2955 * for this port.
2956 */
2957int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2958{
2959 struct uart_state *state = drv->state + uport->line;
2960 struct tty_port *port = &state->port;
2961 struct uart_port *uart_port;
2962 struct tty_struct *tty;
2963 int ret = 0;
2964
2965 BUG_ON(in_interrupt());
2966
2967 mutex_lock(&port_mutex);
2968
2969 /*
2970 * Mark the port "dead" - this prevents any opens from
2971 * succeeding while we shut down the port.
2972 */
2973 mutex_lock(&port->mutex);
2974 uart_port = uart_port_check(state);
2975 if (uart_port != uport)
2976 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2977 uart_port, uport);
2978
2979 if (!uart_port) {
2980 mutex_unlock(&port->mutex);
2981 ret = -EINVAL;
2982 goto out;
2983 }
2984 uport->flags |= UPF_DEAD;
2985 mutex_unlock(&port->mutex);
2986
2987 /*
2988 * Remove the devices from the tty layer
2989 */
2990 tty_port_unregister_device(port, drv->tty_driver, uport->line);
2991
2992 tty = tty_port_tty_get(port);
2993 if (tty) {
2994 tty_vhangup(port->tty);
2995 tty_kref_put(tty);
2996 }
2997
2998 /*
2999 * If the port is used as a console, unregister it
3000 */
3001 if (uart_console(uport))
3002 unregister_console(uport->cons);
3003
3004 /*
3005 * Free the port IO and memory resources, if any.
3006 */
3007 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
3008 uport->ops->release_port(uport);
3009 kfree(uport->tty_groups);
3010 kfree(uport->name);
3011
3012 /*
3013 * Indicate that there isn't a port here anymore.
3014 */
3015 uport->type = PORT_UNKNOWN;
3016
3017 mutex_lock(&port->mutex);
3018 WARN_ON(atomic_dec_return(&state->refcount) < 0);
3019 wait_event(state->remove_wait, !atomic_read(&state->refcount));
3020 state->uart_port = NULL;
3021 mutex_unlock(&port->mutex);
3022out:
3023 mutex_unlock(&port_mutex);
3024
3025 return ret;
3026}
3027
3028/*
3029 * Are the two ports equivalent?
3030 */
3031int uart_match_port(struct uart_port *port1, struct uart_port *port2)
3032{
3033 if (port1->iotype != port2->iotype)
3034 return 0;
3035
3036 switch (port1->iotype) {
3037 case UPIO_PORT:
3038 return (port1->iobase == port2->iobase);
3039 case UPIO_HUB6:
3040 return (port1->iobase == port2->iobase) &&
3041 (port1->hub6 == port2->hub6);
3042 case UPIO_MEM:
3043 case UPIO_MEM16:
3044 case UPIO_MEM32:
3045 case UPIO_MEM32BE:
3046 case UPIO_AU:
3047 case UPIO_TSI:
3048 return (port1->mapbase == port2->mapbase);
3049 }
3050 return 0;
3051}
3052EXPORT_SYMBOL(uart_match_port);
3053
3054/**
3055 * uart_handle_dcd_change - handle a change of carrier detect state
3056 * @uport: uart_port structure for the open port
3057 * @status: new carrier detect status, nonzero if active
3058 *
3059 * Caller must hold uport->lock
3060 */
3061void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
3062{
3063 struct tty_port *port = &uport->state->port;
3064 struct tty_struct *tty = port->tty;
3065 struct tty_ldisc *ld;
3066
3067 lockdep_assert_held_once(&uport->lock);
3068
3069 if (tty) {
3070 ld = tty_ldisc_ref(tty);
3071 if (ld) {
3072 if (ld->ops->dcd_change)
3073 ld->ops->dcd_change(tty, status);
3074 tty_ldisc_deref(ld);
3075 }
3076 }
3077
3078 uport->icount.dcd++;
3079
3080 if (uart_dcd_enabled(uport)) {
3081 if (status)
3082 wake_up_interruptible(&port->open_wait);
3083 else if (tty)
3084 tty_hangup(tty);
3085 }
3086}
3087EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
3088
3089/**
3090 * uart_handle_cts_change - handle a change of clear-to-send state
3091 * @uport: uart_port structure for the open port
3092 * @status: new clear to send status, nonzero if active
3093 *
3094 * Caller must hold uport->lock
3095 */
3096void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
3097{
3098 lockdep_assert_held_once(&uport->lock);
3099
3100 uport->icount.cts++;
3101
3102 if (uart_softcts_mode(uport)) {
3103 if (uport->hw_stopped) {
3104 if (status) {
3105 uport->hw_stopped = 0;
3106 uport->ops->start_tx(uport);
3107 uart_write_wakeup(uport);
3108 }
3109 } else {
3110 if (!status) {
3111 uport->hw_stopped = 1;
3112 uport->ops->stop_tx(uport);
3113 }
3114 }
3115
3116 }
3117}
3118EXPORT_SYMBOL_GPL(uart_handle_cts_change);
3119
3120/**
3121 * uart_insert_char - push a char to the uart layer
3122 *
3123 * User is responsible to call tty_flip_buffer_push when they are done with
3124 * insertion.
3125 *
3126 * @port: corresponding port
3127 * @status: state of the serial port RX buffer (LSR for 8250)
3128 * @overrun: mask of overrun bits in @status
3129 * @ch: character to push
3130 * @flag: flag for the character (see TTY_NORMAL and friends)
3131 */
3132void uart_insert_char(struct uart_port *port, unsigned int status,
3133 unsigned int overrun, unsigned int ch, unsigned int flag)
3134{
3135 struct tty_port *tport = &port->state->port;
3136
3137 if ((status & port->ignore_status_mask & ~overrun) == 0)
3138 if (tty_insert_flip_char(tport, ch, flag) == 0)
3139 ++port->icount.buf_overrun;
3140
3141 /*
3142 * Overrun is special. Since it's reported immediately,
3143 * it doesn't affect the current character.
3144 */
3145 if (status & ~port->ignore_status_mask & overrun)
3146 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
3147 ++port->icount.buf_overrun;
3148}
3149EXPORT_SYMBOL_GPL(uart_insert_char);
3150
3151#ifdef CONFIG_MAGIC_SYSRQ_SERIAL
3152static const char sysrq_toggle_seq[] = CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE;
3153
3154static void uart_sysrq_on(struct work_struct *w)
3155{
3156 int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq);
3157
3158 sysrq_toggle_support(1);
3159 pr_info("SysRq is enabled by magic sequence '%*pE' on serial\n",
3160 sysrq_toggle_seq_len, sysrq_toggle_seq);
3161}
3162static DECLARE_WORK(sysrq_enable_work, uart_sysrq_on);
3163
3164/**
3165 * uart_try_toggle_sysrq - Enables SysRq from serial line
3166 * @port: uart_port structure where char(s) after BREAK met
3167 * @ch: new character in the sequence after received BREAK
3168 *
3169 * Enables magic SysRq when the required sequence is met on port
3170 * (see CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE).
3171 *
3172 * Returns false if @ch is out of enabling sequence and should be
3173 * handled some other way, true if @ch was consumed.
3174 */
3175bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch)
3176{
3177 int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq);
3178
3179 if (!sysrq_toggle_seq_len)
3180 return false;
3181
3182 BUILD_BUG_ON(ARRAY_SIZE(sysrq_toggle_seq) >= U8_MAX);
3183 if (sysrq_toggle_seq[port->sysrq_seq] != ch) {
3184 port->sysrq_seq = 0;
3185 return false;
3186 }
3187
3188 if (++port->sysrq_seq < sysrq_toggle_seq_len) {
3189 port->sysrq = jiffies + SYSRQ_TIMEOUT;
3190 return true;
3191 }
3192
3193 schedule_work(&sysrq_enable_work);
3194
3195 port->sysrq = 0;
3196 return true;
3197}
3198EXPORT_SYMBOL_GPL(uart_try_toggle_sysrq);
3199#endif
3200
3201EXPORT_SYMBOL(uart_write_wakeup);
3202EXPORT_SYMBOL(uart_register_driver);
3203EXPORT_SYMBOL(uart_unregister_driver);
3204EXPORT_SYMBOL(uart_suspend_port);
3205EXPORT_SYMBOL(uart_resume_port);
3206EXPORT_SYMBOL(uart_add_one_port);
3207EXPORT_SYMBOL(uart_remove_one_port);
3208
3209/**
3210 * uart_get_rs485_mode() - retrieve rs485 properties for given uart
3211 * @port: uart device's target port
3212 *
3213 * This function implements the device tree binding described in
3214 * Documentation/devicetree/bindings/serial/rs485.txt.
3215 */
3216int uart_get_rs485_mode(struct uart_port *port)
3217{
3218 struct serial_rs485 *rs485conf = &port->rs485;
3219 struct device *dev = port->dev;
3220 u32 rs485_delay[2];
3221 int ret;
3222
3223 ret = device_property_read_u32_array(dev, "rs485-rts-delay",
3224 rs485_delay, 2);
3225 if (!ret) {
3226 rs485conf->delay_rts_before_send = rs485_delay[0];
3227 rs485conf->delay_rts_after_send = rs485_delay[1];
3228 } else {
3229 rs485conf->delay_rts_before_send = 0;
3230 rs485conf->delay_rts_after_send = 0;
3231 }
3232
3233 /*
3234 * Clear full-duplex and enabled flags, set RTS polarity to active high
3235 * to get to a defined state with the following properties:
3236 */
3237 rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED |
3238 SER_RS485_TERMINATE_BUS |
3239 SER_RS485_RTS_AFTER_SEND);
3240 rs485conf->flags |= SER_RS485_RTS_ON_SEND;
3241
3242 if (device_property_read_bool(dev, "rs485-rx-during-tx"))
3243 rs485conf->flags |= SER_RS485_RX_DURING_TX;
3244
3245 if (device_property_read_bool(dev, "linux,rs485-enabled-at-boot-time"))
3246 rs485conf->flags |= SER_RS485_ENABLED;
3247
3248 if (device_property_read_bool(dev, "rs485-rts-active-low")) {
3249 rs485conf->flags &= ~SER_RS485_RTS_ON_SEND;
3250 rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
3251 }
3252
3253 /*
3254 * Disabling termination by default is the safe choice: Else if many
3255 * bus participants enable it, no communication is possible at all.
3256 * Works fine for short cables and users may enable for longer cables.
3257 */
3258 port->rs485_term_gpio = devm_gpiod_get_optional(dev, "rs485-term",
3259 GPIOD_OUT_LOW);
3260 if (IS_ERR(port->rs485_term_gpio)) {
3261 ret = PTR_ERR(port->rs485_term_gpio);
3262 port->rs485_term_gpio = NULL;
3263 if (ret != -EPROBE_DEFER)
3264 dev_err(dev, "Cannot get rs485-term-gpios\n");
3265 return ret;
3266 }
3267
3268 return 0;
3269}
3270EXPORT_SYMBOL_GPL(uart_get_rs485_mode);
3271
3272MODULE_DESCRIPTION("Serial driver core");
3273MODULE_LICENSE("GPL");