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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/kernel.h>
19#include <linux/of.h>
20#include <linux/pm_runtime.h>
21#include <linux/proc_fs.h>
22#include <linux/seq_file.h>
23#include <linux/device.h>
24#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
25#include <linux/serial_core.h>
26#include <linux/sysrq.h>
27#include <linux/delay.h>
28#include <linux/mutex.h>
29#include <linux/math64.h>
30#include <linux/security.h>
31
32#include <linux/irq.h>
33#include <linux/uaccess.h>
34
35#include "serial_base.h"
36
37/*
38 * This is used to lock changes in serial line configuration.
39 */
40static DEFINE_MUTEX(port_mutex);
41
42/*
43 * lockdep: port->lock is initialized in two places, but we
44 * want only one lock-class:
45 */
46static struct lock_class_key port_lock_key;
47
48#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
49
50/*
51 * Max time with active RTS before/after data is sent.
52 */
53#define RS485_MAX_RTS_DELAY 100 /* msecs */
54
55static void uart_change_pm(struct uart_state *state,
56 enum uart_pm_state pm_state);
57
58static void uart_port_shutdown(struct tty_port *port);
59
60static int uart_dcd_enabled(struct uart_port *uport)
61{
62 return !!(uport->status & UPSTAT_DCD_ENABLE);
63}
64
65static inline struct uart_port *uart_port_ref(struct uart_state *state)
66{
67 if (atomic_add_unless(&state->refcount, 1, 0))
68 return state->uart_port;
69 return NULL;
70}
71
72static inline void uart_port_deref(struct uart_port *uport)
73{
74 if (atomic_dec_and_test(&uport->state->refcount))
75 wake_up(&uport->state->remove_wait);
76}
77
78#define uart_port_lock(state, flags) \
79 ({ \
80 struct uart_port *__uport = uart_port_ref(state); \
81 if (__uport) \
82 uart_port_lock_irqsave(__uport, &flags); \
83 __uport; \
84 })
85
86#define uart_port_unlock(uport, flags) \
87 ({ \
88 struct uart_port *__uport = uport; \
89 if (__uport) { \
90 uart_port_unlock_irqrestore(__uport, flags); \
91 uart_port_deref(__uport); \
92 } \
93 })
94
95static inline struct uart_port *uart_port_check(struct uart_state *state)
96{
97 lockdep_assert_held(&state->port.mutex);
98 return state->uart_port;
99}
100
101/**
102 * uart_write_wakeup - schedule write processing
103 * @port: port to be processed
104 *
105 * This routine is used by the interrupt handler to schedule processing in the
106 * software interrupt portion of the driver. A driver is expected to call this
107 * function when the number of characters in the transmit buffer have dropped
108 * below a threshold.
109 *
110 * Locking: @port->lock should be held
111 */
112void uart_write_wakeup(struct uart_port *port)
113{
114 struct uart_state *state = port->state;
115 /*
116 * This means you called this function _after_ the port was
117 * closed. No cookie for you.
118 */
119 BUG_ON(!state);
120 tty_port_tty_wakeup(&state->port);
121}
122EXPORT_SYMBOL(uart_write_wakeup);
123
124static void uart_stop(struct tty_struct *tty)
125{
126 struct uart_state *state = tty->driver_data;
127 struct uart_port *port;
128 unsigned long flags;
129
130 port = uart_port_lock(state, flags);
131 if (port)
132 port->ops->stop_tx(port);
133 uart_port_unlock(port, flags);
134}
135
136static void __uart_start(struct uart_state *state)
137{
138 struct uart_port *port = state->uart_port;
139 struct serial_port_device *port_dev;
140 int err;
141
142 if (!port || port->flags & UPF_DEAD || uart_tx_stopped(port))
143 return;
144
145 port_dev = port->port_dev;
146
147 /* Increment the runtime PM usage count for the active check below */
148 err = pm_runtime_get(&port_dev->dev);
149 if (err < 0 && err != -EINPROGRESS) {
150 pm_runtime_put_noidle(&port_dev->dev);
151 return;
152 }
153
154 /*
155 * Start TX if enabled, and kick runtime PM. If the device is not
156 * enabled, serial_port_runtime_resume() calls start_tx() again
157 * after enabling the device.
158 */
159 if (!pm_runtime_enabled(port->dev) || pm_runtime_active(&port_dev->dev))
160 port->ops->start_tx(port);
161 pm_runtime_mark_last_busy(&port_dev->dev);
162 pm_runtime_put_autosuspend(&port_dev->dev);
163}
164
165static void uart_start(struct tty_struct *tty)
166{
167 struct uart_state *state = tty->driver_data;
168 struct uart_port *port;
169 unsigned long flags;
170
171 port = uart_port_lock(state, flags);
172 __uart_start(state);
173 uart_port_unlock(port, flags);
174}
175
176static void
177uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
178{
179 unsigned long flags;
180 unsigned int old;
181
182 uart_port_lock_irqsave(port, &flags);
183 old = port->mctrl;
184 port->mctrl = (old & ~clear) | set;
185 if (old != port->mctrl && !(port->rs485.flags & SER_RS485_ENABLED))
186 port->ops->set_mctrl(port, port->mctrl);
187 uart_port_unlock_irqrestore(port, flags);
188}
189
190#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
191#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
192
193static void uart_port_dtr_rts(struct uart_port *uport, bool active)
194{
195 if (active)
196 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
197 else
198 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
199}
200
201/* Caller holds port mutex */
202static void uart_change_line_settings(struct tty_struct *tty, struct uart_state *state,
203 const struct ktermios *old_termios)
204{
205 struct uart_port *uport = uart_port_check(state);
206 struct ktermios *termios;
207 bool old_hw_stopped;
208
209 /*
210 * If we have no tty, termios, or the port does not exist,
211 * then we can't set the parameters for this port.
212 */
213 if (!tty || uport->type == PORT_UNKNOWN)
214 return;
215
216 termios = &tty->termios;
217 uport->ops->set_termios(uport, termios, old_termios);
218
219 /*
220 * Set modem status enables based on termios cflag
221 */
222 uart_port_lock_irq(uport);
223 if (termios->c_cflag & CRTSCTS)
224 uport->status |= UPSTAT_CTS_ENABLE;
225 else
226 uport->status &= ~UPSTAT_CTS_ENABLE;
227
228 if (termios->c_cflag & CLOCAL)
229 uport->status &= ~UPSTAT_DCD_ENABLE;
230 else
231 uport->status |= UPSTAT_DCD_ENABLE;
232
233 /* reset sw-assisted CTS flow control based on (possibly) new mode */
234 old_hw_stopped = uport->hw_stopped;
235 uport->hw_stopped = uart_softcts_mode(uport) &&
236 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
237 if (uport->hw_stopped != old_hw_stopped) {
238 if (!old_hw_stopped)
239 uport->ops->stop_tx(uport);
240 else
241 __uart_start(state);
242 }
243 uart_port_unlock_irq(uport);
244}
245
246/*
247 * Startup the port. This will be called once per open. All calls
248 * will be serialised by the per-port mutex.
249 */
250static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
251 bool init_hw)
252{
253 struct uart_port *uport = uart_port_check(state);
254 unsigned long flags;
255 unsigned long page;
256 int retval = 0;
257
258 if (uport->type == PORT_UNKNOWN)
259 return 1;
260
261 /*
262 * Make sure the device is in D0 state.
263 */
264 uart_change_pm(state, UART_PM_STATE_ON);
265
266 /*
267 * Initialise and allocate the transmit and temporary
268 * buffer.
269 */
270 page = get_zeroed_page(GFP_KERNEL);
271 if (!page)
272 return -ENOMEM;
273
274 uart_port_lock(state, flags);
275 if (!state->xmit.buf) {
276 state->xmit.buf = (unsigned char *) page;
277 uart_circ_clear(&state->xmit);
278 uart_port_unlock(uport, flags);
279 } else {
280 uart_port_unlock(uport, flags);
281 /*
282 * Do not free() the page under the port lock, see
283 * uart_shutdown().
284 */
285 free_page(page);
286 }
287
288 retval = uport->ops->startup(uport);
289 if (retval == 0) {
290 if (uart_console(uport) && uport->cons->cflag) {
291 tty->termios.c_cflag = uport->cons->cflag;
292 tty->termios.c_ispeed = uport->cons->ispeed;
293 tty->termios.c_ospeed = uport->cons->ospeed;
294 uport->cons->cflag = 0;
295 uport->cons->ispeed = 0;
296 uport->cons->ospeed = 0;
297 }
298 /*
299 * Initialise the hardware port settings.
300 */
301 uart_change_line_settings(tty, state, NULL);
302
303 /*
304 * Setup the RTS and DTR signals once the
305 * port is open and ready to respond.
306 */
307 if (init_hw && C_BAUD(tty))
308 uart_port_dtr_rts(uport, true);
309 }
310
311 /*
312 * This is to allow setserial on this port. People may want to set
313 * port/irq/type and then reconfigure the port properly if it failed
314 * now.
315 */
316 if (retval && capable(CAP_SYS_ADMIN))
317 return 1;
318
319 return retval;
320}
321
322static int uart_startup(struct tty_struct *tty, struct uart_state *state,
323 bool init_hw)
324{
325 struct tty_port *port = &state->port;
326 struct uart_port *uport;
327 int retval;
328
329 if (tty_port_initialized(port))
330 goto out_base_port_startup;
331
332 retval = uart_port_startup(tty, state, init_hw);
333 if (retval) {
334 set_bit(TTY_IO_ERROR, &tty->flags);
335 return retval;
336 }
337
338out_base_port_startup:
339 uport = uart_port_check(state);
340 if (!uport)
341 return -EIO;
342
343 serial_base_port_startup(uport);
344
345 return 0;
346}
347
348/*
349 * This routine will shutdown a serial port; interrupts are disabled, and
350 * DTR is dropped if the hangup on close termio flag is on. Calls to
351 * uart_shutdown are serialised by the per-port semaphore.
352 *
353 * uport == NULL if uart_port has already been removed
354 */
355static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
356{
357 struct uart_port *uport = uart_port_check(state);
358 struct tty_port *port = &state->port;
359 unsigned long flags;
360 char *xmit_buf = NULL;
361
362 /*
363 * Set the TTY IO error marker
364 */
365 if (tty)
366 set_bit(TTY_IO_ERROR, &tty->flags);
367
368 if (uport)
369 serial_base_port_shutdown(uport);
370
371 if (tty_port_initialized(port)) {
372 tty_port_set_initialized(port, false);
373
374 /*
375 * Turn off DTR and RTS early.
376 */
377 if (uport && uart_console(uport) && tty) {
378 uport->cons->cflag = tty->termios.c_cflag;
379 uport->cons->ispeed = tty->termios.c_ispeed;
380 uport->cons->ospeed = tty->termios.c_ospeed;
381 }
382
383 if (!tty || C_HUPCL(tty))
384 uart_port_dtr_rts(uport, false);
385
386 uart_port_shutdown(port);
387 }
388
389 /*
390 * It's possible for shutdown to be called after suspend if we get
391 * a DCD drop (hangup) at just the right time. Clear suspended bit so
392 * we don't try to resume a port that has been shutdown.
393 */
394 tty_port_set_suspended(port, false);
395
396 /*
397 * Do not free() the transmit buffer page under the port lock since
398 * this can create various circular locking scenarios. For instance,
399 * console driver may need to allocate/free a debug object, which
400 * can endup in printk() recursion.
401 */
402 uart_port_lock(state, flags);
403 xmit_buf = state->xmit.buf;
404 state->xmit.buf = NULL;
405 uart_port_unlock(uport, flags);
406
407 free_page((unsigned long)xmit_buf);
408}
409
410/**
411 * uart_update_timeout - update per-port frame timing information
412 * @port: uart_port structure describing the port
413 * @cflag: termios cflag value
414 * @baud: speed of the port
415 *
416 * Set the @port frame timing information from which the FIFO timeout value is
417 * derived. The @cflag value should reflect the actual hardware settings as
418 * number of bits, parity, stop bits and baud rate is taken into account here.
419 *
420 * Locking: caller is expected to take @port->lock
421 */
422void
423uart_update_timeout(struct uart_port *port, unsigned int cflag,
424 unsigned int baud)
425{
426 u64 temp = tty_get_frame_size(cflag);
427
428 temp *= NSEC_PER_SEC;
429 port->frame_time = (unsigned int)DIV64_U64_ROUND_UP(temp, baud);
430}
431EXPORT_SYMBOL(uart_update_timeout);
432
433/**
434 * uart_get_baud_rate - return baud rate for a particular port
435 * @port: uart_port structure describing the port in question.
436 * @termios: desired termios settings
437 * @old: old termios (or %NULL)
438 * @min: minimum acceptable baud rate
439 * @max: maximum acceptable baud rate
440 *
441 * Decode the termios structure into a numeric baud rate, taking account of the
442 * magic 38400 baud rate (with spd_* flags), and mapping the %B0 rate to 9600
443 * baud.
444 *
445 * If the new baud rate is invalid, try the @old termios setting. If it's still
446 * invalid, we try 9600 baud. If that is also invalid 0 is returned.
447 *
448 * The @termios structure is updated to reflect the baud rate we're actually
449 * going to be using. Don't do this for the case where B0 is requested ("hang
450 * up").
451 *
452 * Locking: caller dependent
453 */
454unsigned int
455uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
456 const struct ktermios *old, unsigned int min, unsigned int max)
457{
458 unsigned int try;
459 unsigned int baud;
460 unsigned int altbaud;
461 int hung_up = 0;
462 upf_t flags = port->flags & UPF_SPD_MASK;
463
464 switch (flags) {
465 case UPF_SPD_HI:
466 altbaud = 57600;
467 break;
468 case UPF_SPD_VHI:
469 altbaud = 115200;
470 break;
471 case UPF_SPD_SHI:
472 altbaud = 230400;
473 break;
474 case UPF_SPD_WARP:
475 altbaud = 460800;
476 break;
477 default:
478 altbaud = 38400;
479 break;
480 }
481
482 for (try = 0; try < 2; try++) {
483 baud = tty_termios_baud_rate(termios);
484
485 /*
486 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
487 * Die! Die! Die!
488 */
489 if (try == 0 && baud == 38400)
490 baud = altbaud;
491
492 /*
493 * Special case: B0 rate.
494 */
495 if (baud == 0) {
496 hung_up = 1;
497 baud = 9600;
498 }
499
500 if (baud >= min && baud <= max)
501 return baud;
502
503 /*
504 * Oops, the quotient was zero. Try again with
505 * the old baud rate if possible.
506 */
507 termios->c_cflag &= ~CBAUD;
508 if (old) {
509 baud = tty_termios_baud_rate(old);
510 if (!hung_up)
511 tty_termios_encode_baud_rate(termios,
512 baud, baud);
513 old = NULL;
514 continue;
515 }
516
517 /*
518 * As a last resort, if the range cannot be met then clip to
519 * the nearest chip supported rate.
520 */
521 if (!hung_up) {
522 if (baud <= min)
523 tty_termios_encode_baud_rate(termios,
524 min + 1, min + 1);
525 else
526 tty_termios_encode_baud_rate(termios,
527 max - 1, max - 1);
528 }
529 }
530 return 0;
531}
532EXPORT_SYMBOL(uart_get_baud_rate);
533
534/**
535 * uart_get_divisor - return uart clock divisor
536 * @port: uart_port structure describing the port
537 * @baud: desired baud rate
538 *
539 * Calculate the divisor (baud_base / baud) for the specified @baud,
540 * appropriately rounded.
541 *
542 * If 38400 baud and custom divisor is selected, return the custom divisor
543 * instead.
544 *
545 * Locking: caller dependent
546 */
547unsigned int
548uart_get_divisor(struct uart_port *port, unsigned int baud)
549{
550 unsigned int quot;
551
552 /*
553 * Old custom speed handling.
554 */
555 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
556 quot = port->custom_divisor;
557 else
558 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
559
560 return quot;
561}
562EXPORT_SYMBOL(uart_get_divisor);
563
564static int uart_put_char(struct tty_struct *tty, u8 c)
565{
566 struct uart_state *state = tty->driver_data;
567 struct uart_port *port;
568 struct circ_buf *circ;
569 unsigned long flags;
570 int ret = 0;
571
572 circ = &state->xmit;
573 port = uart_port_lock(state, flags);
574 if (!circ->buf) {
575 uart_port_unlock(port, flags);
576 return 0;
577 }
578
579 if (port && uart_circ_chars_free(circ) != 0) {
580 circ->buf[circ->head] = c;
581 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
582 ret = 1;
583 }
584 uart_port_unlock(port, flags);
585 return ret;
586}
587
588static void uart_flush_chars(struct tty_struct *tty)
589{
590 uart_start(tty);
591}
592
593static ssize_t uart_write(struct tty_struct *tty, const u8 *buf, size_t count)
594{
595 struct uart_state *state = tty->driver_data;
596 struct uart_port *port;
597 struct circ_buf *circ;
598 unsigned long flags;
599 int c, ret = 0;
600
601 /*
602 * This means you called this function _after_ the port was
603 * closed. No cookie for you.
604 */
605 if (WARN_ON(!state))
606 return -EL3HLT;
607
608 port = uart_port_lock(state, flags);
609 circ = &state->xmit;
610 if (!circ->buf) {
611 uart_port_unlock(port, flags);
612 return 0;
613 }
614
615 while (port) {
616 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
617 if (count < c)
618 c = count;
619 if (c <= 0)
620 break;
621 memcpy(circ->buf + circ->head, buf, c);
622 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
623 buf += c;
624 count -= c;
625 ret += c;
626 }
627
628 __uart_start(state);
629 uart_port_unlock(port, flags);
630 return ret;
631}
632
633static unsigned int uart_write_room(struct tty_struct *tty)
634{
635 struct uart_state *state = tty->driver_data;
636 struct uart_port *port;
637 unsigned long flags;
638 unsigned int ret;
639
640 port = uart_port_lock(state, flags);
641 ret = uart_circ_chars_free(&state->xmit);
642 uart_port_unlock(port, flags);
643 return ret;
644}
645
646static unsigned int uart_chars_in_buffer(struct tty_struct *tty)
647{
648 struct uart_state *state = tty->driver_data;
649 struct uart_port *port;
650 unsigned long flags;
651 unsigned int ret;
652
653 port = uart_port_lock(state, flags);
654 ret = uart_circ_chars_pending(&state->xmit);
655 uart_port_unlock(port, flags);
656 return ret;
657}
658
659static void uart_flush_buffer(struct tty_struct *tty)
660{
661 struct uart_state *state = tty->driver_data;
662 struct uart_port *port;
663 unsigned long flags;
664
665 /*
666 * This means you called this function _after_ the port was
667 * closed. No cookie for you.
668 */
669 if (WARN_ON(!state))
670 return;
671
672 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
673
674 port = uart_port_lock(state, flags);
675 if (!port)
676 return;
677 uart_circ_clear(&state->xmit);
678 if (port->ops->flush_buffer)
679 port->ops->flush_buffer(port);
680 uart_port_unlock(port, flags);
681 tty_port_tty_wakeup(&state->port);
682}
683
684/*
685 * This function performs low-level write of high-priority XON/XOFF
686 * character and accounting for it.
687 *
688 * Requires uart_port to implement .serial_out().
689 */
690void uart_xchar_out(struct uart_port *uport, int offset)
691{
692 serial_port_out(uport, offset, uport->x_char);
693 uport->icount.tx++;
694 uport->x_char = 0;
695}
696EXPORT_SYMBOL_GPL(uart_xchar_out);
697
698/*
699 * This function is used to send a high-priority XON/XOFF character to
700 * the device
701 */
702static void uart_send_xchar(struct tty_struct *tty, u8 ch)
703{
704 struct uart_state *state = tty->driver_data;
705 struct uart_port *port;
706 unsigned long flags;
707
708 port = uart_port_ref(state);
709 if (!port)
710 return;
711
712 if (port->ops->send_xchar)
713 port->ops->send_xchar(port, ch);
714 else {
715 uart_port_lock_irqsave(port, &flags);
716 port->x_char = ch;
717 if (ch)
718 port->ops->start_tx(port);
719 uart_port_unlock_irqrestore(port, flags);
720 }
721 uart_port_deref(port);
722}
723
724static void uart_throttle(struct tty_struct *tty)
725{
726 struct uart_state *state = tty->driver_data;
727 upstat_t mask = UPSTAT_SYNC_FIFO;
728 struct uart_port *port;
729
730 port = uart_port_ref(state);
731 if (!port)
732 return;
733
734 if (I_IXOFF(tty))
735 mask |= UPSTAT_AUTOXOFF;
736 if (C_CRTSCTS(tty))
737 mask |= UPSTAT_AUTORTS;
738
739 if (port->status & mask) {
740 port->ops->throttle(port);
741 mask &= ~port->status;
742 }
743
744 if (mask & UPSTAT_AUTORTS)
745 uart_clear_mctrl(port, TIOCM_RTS);
746
747 if (mask & UPSTAT_AUTOXOFF)
748 uart_send_xchar(tty, STOP_CHAR(tty));
749
750 uart_port_deref(port);
751}
752
753static void uart_unthrottle(struct tty_struct *tty)
754{
755 struct uart_state *state = tty->driver_data;
756 upstat_t mask = UPSTAT_SYNC_FIFO;
757 struct uart_port *port;
758
759 port = uart_port_ref(state);
760 if (!port)
761 return;
762
763 if (I_IXOFF(tty))
764 mask |= UPSTAT_AUTOXOFF;
765 if (C_CRTSCTS(tty))
766 mask |= UPSTAT_AUTORTS;
767
768 if (port->status & mask) {
769 port->ops->unthrottle(port);
770 mask &= ~port->status;
771 }
772
773 if (mask & UPSTAT_AUTORTS)
774 uart_set_mctrl(port, TIOCM_RTS);
775
776 if (mask & UPSTAT_AUTOXOFF)
777 uart_send_xchar(tty, START_CHAR(tty));
778
779 uart_port_deref(port);
780}
781
782static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
783{
784 struct uart_state *state = container_of(port, struct uart_state, port);
785 struct uart_port *uport;
786 int ret = -ENODEV;
787
788 /* Initialize structure in case we error out later to prevent any stack info leakage. */
789 *retinfo = (struct serial_struct){};
790
791 /*
792 * Ensure the state we copy is consistent and no hardware changes
793 * occur as we go
794 */
795 mutex_lock(&port->mutex);
796 uport = uart_port_check(state);
797 if (!uport)
798 goto out;
799
800 retinfo->type = uport->type;
801 retinfo->line = uport->line;
802 retinfo->port = uport->iobase;
803 if (HIGH_BITS_OFFSET)
804 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
805 retinfo->irq = uport->irq;
806 retinfo->flags = (__force int)uport->flags;
807 retinfo->xmit_fifo_size = uport->fifosize;
808 retinfo->baud_base = uport->uartclk / 16;
809 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
810 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
811 ASYNC_CLOSING_WAIT_NONE :
812 jiffies_to_msecs(port->closing_wait) / 10;
813 retinfo->custom_divisor = uport->custom_divisor;
814 retinfo->hub6 = uport->hub6;
815 retinfo->io_type = uport->iotype;
816 retinfo->iomem_reg_shift = uport->regshift;
817 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
818
819 ret = 0;
820out:
821 mutex_unlock(&port->mutex);
822 return ret;
823}
824
825static int uart_get_info_user(struct tty_struct *tty,
826 struct serial_struct *ss)
827{
828 struct uart_state *state = tty->driver_data;
829 struct tty_port *port = &state->port;
830
831 return uart_get_info(port, ss) < 0 ? -EIO : 0;
832}
833
834static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
835 struct uart_state *state,
836 struct serial_struct *new_info)
837{
838 struct uart_port *uport = uart_port_check(state);
839 unsigned long new_port;
840 unsigned int change_irq, change_port, closing_wait;
841 unsigned int old_custom_divisor, close_delay;
842 upf_t old_flags, new_flags;
843 int retval = 0;
844
845 if (!uport)
846 return -EIO;
847
848 new_port = new_info->port;
849 if (HIGH_BITS_OFFSET)
850 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
851
852 new_info->irq = irq_canonicalize(new_info->irq);
853 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
854 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
855 ASYNC_CLOSING_WAIT_NONE :
856 msecs_to_jiffies(new_info->closing_wait * 10);
857
858
859 change_irq = !(uport->flags & UPF_FIXED_PORT)
860 && new_info->irq != uport->irq;
861
862 /*
863 * Since changing the 'type' of the port changes its resource
864 * allocations, we should treat type changes the same as
865 * IO port changes.
866 */
867 change_port = !(uport->flags & UPF_FIXED_PORT)
868 && (new_port != uport->iobase ||
869 (unsigned long)new_info->iomem_base != uport->mapbase ||
870 new_info->hub6 != uport->hub6 ||
871 new_info->io_type != uport->iotype ||
872 new_info->iomem_reg_shift != uport->regshift ||
873 new_info->type != uport->type);
874
875 old_flags = uport->flags;
876 new_flags = (__force upf_t)new_info->flags;
877 old_custom_divisor = uport->custom_divisor;
878
879 if (!capable(CAP_SYS_ADMIN)) {
880 retval = -EPERM;
881 if (change_irq || change_port ||
882 (new_info->baud_base != uport->uartclk / 16) ||
883 (close_delay != port->close_delay) ||
884 (closing_wait != port->closing_wait) ||
885 (new_info->xmit_fifo_size &&
886 new_info->xmit_fifo_size != uport->fifosize) ||
887 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
888 goto exit;
889 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
890 (new_flags & UPF_USR_MASK));
891 uport->custom_divisor = new_info->custom_divisor;
892 goto check_and_exit;
893 }
894
895 if (change_irq || change_port) {
896 retval = security_locked_down(LOCKDOWN_TIOCSSERIAL);
897 if (retval)
898 goto exit;
899 }
900
901 /*
902 * Ask the low level driver to verify the settings.
903 */
904 if (uport->ops->verify_port)
905 retval = uport->ops->verify_port(uport, new_info);
906
907 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
908 (new_info->baud_base < 9600))
909 retval = -EINVAL;
910
911 if (retval)
912 goto exit;
913
914 if (change_port || change_irq) {
915 retval = -EBUSY;
916
917 /*
918 * Make sure that we are the sole user of this port.
919 */
920 if (tty_port_users(port) > 1)
921 goto exit;
922
923 /*
924 * We need to shutdown the serial port at the old
925 * port/type/irq combination.
926 */
927 uart_shutdown(tty, state);
928 }
929
930 if (change_port) {
931 unsigned long old_iobase, old_mapbase;
932 unsigned int old_type, old_iotype, old_hub6, old_shift;
933
934 old_iobase = uport->iobase;
935 old_mapbase = uport->mapbase;
936 old_type = uport->type;
937 old_hub6 = uport->hub6;
938 old_iotype = uport->iotype;
939 old_shift = uport->regshift;
940
941 /*
942 * Free and release old regions
943 */
944 if (old_type != PORT_UNKNOWN && uport->ops->release_port)
945 uport->ops->release_port(uport);
946
947 uport->iobase = new_port;
948 uport->type = new_info->type;
949 uport->hub6 = new_info->hub6;
950 uport->iotype = new_info->io_type;
951 uport->regshift = new_info->iomem_reg_shift;
952 uport->mapbase = (unsigned long)new_info->iomem_base;
953
954 /*
955 * Claim and map the new regions
956 */
957 if (uport->type != PORT_UNKNOWN && uport->ops->request_port) {
958 retval = uport->ops->request_port(uport);
959 } else {
960 /* Always success - Jean II */
961 retval = 0;
962 }
963
964 /*
965 * If we fail to request resources for the
966 * new port, try to restore the old settings.
967 */
968 if (retval) {
969 uport->iobase = old_iobase;
970 uport->type = old_type;
971 uport->hub6 = old_hub6;
972 uport->iotype = old_iotype;
973 uport->regshift = old_shift;
974 uport->mapbase = old_mapbase;
975
976 if (old_type != PORT_UNKNOWN) {
977 retval = uport->ops->request_port(uport);
978 /*
979 * If we failed to restore the old settings,
980 * we fail like this.
981 */
982 if (retval)
983 uport->type = PORT_UNKNOWN;
984
985 /*
986 * We failed anyway.
987 */
988 retval = -EBUSY;
989 }
990
991 /* Added to return the correct error -Ram Gupta */
992 goto exit;
993 }
994 }
995
996 if (change_irq)
997 uport->irq = new_info->irq;
998 if (!(uport->flags & UPF_FIXED_PORT))
999 uport->uartclk = new_info->baud_base * 16;
1000 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
1001 (new_flags & UPF_CHANGE_MASK);
1002 uport->custom_divisor = new_info->custom_divisor;
1003 port->close_delay = close_delay;
1004 port->closing_wait = closing_wait;
1005 if (new_info->xmit_fifo_size)
1006 uport->fifosize = new_info->xmit_fifo_size;
1007
1008 check_and_exit:
1009 retval = 0;
1010 if (uport->type == PORT_UNKNOWN)
1011 goto exit;
1012 if (tty_port_initialized(port)) {
1013 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
1014 old_custom_divisor != uport->custom_divisor) {
1015 /*
1016 * If they're setting up a custom divisor or speed,
1017 * instead of clearing it, then bitch about it.
1018 */
1019 if (uport->flags & UPF_SPD_MASK) {
1020 dev_notice_ratelimited(uport->dev,
1021 "%s sets custom speed on %s. This is deprecated.\n",
1022 current->comm,
1023 tty_name(port->tty));
1024 }
1025 uart_change_line_settings(tty, state, NULL);
1026 }
1027 } else {
1028 retval = uart_startup(tty, state, true);
1029 if (retval == 0)
1030 tty_port_set_initialized(port, true);
1031 if (retval > 0)
1032 retval = 0;
1033 }
1034 exit:
1035 return retval;
1036}
1037
1038static int uart_set_info_user(struct tty_struct *tty, struct serial_struct *ss)
1039{
1040 struct uart_state *state = tty->driver_data;
1041 struct tty_port *port = &state->port;
1042 int retval;
1043
1044 down_write(&tty->termios_rwsem);
1045 /*
1046 * This semaphore protects port->count. It is also
1047 * very useful to prevent opens. Also, take the
1048 * port configuration semaphore to make sure that a
1049 * module insertion/removal doesn't change anything
1050 * under us.
1051 */
1052 mutex_lock(&port->mutex);
1053 retval = uart_set_info(tty, port, state, ss);
1054 mutex_unlock(&port->mutex);
1055 up_write(&tty->termios_rwsem);
1056 return retval;
1057}
1058
1059/**
1060 * uart_get_lsr_info - get line status register info
1061 * @tty: tty associated with the UART
1062 * @state: UART being queried
1063 * @value: returned modem value
1064 */
1065static int uart_get_lsr_info(struct tty_struct *tty,
1066 struct uart_state *state, unsigned int __user *value)
1067{
1068 struct uart_port *uport = uart_port_check(state);
1069 unsigned int result;
1070
1071 result = uport->ops->tx_empty(uport);
1072
1073 /*
1074 * If we're about to load something into the transmit
1075 * register, we'll pretend the transmitter isn't empty to
1076 * avoid a race condition (depending on when the transmit
1077 * interrupt happens).
1078 */
1079 if (uport->x_char ||
1080 ((uart_circ_chars_pending(&state->xmit) > 0) &&
1081 !uart_tx_stopped(uport)))
1082 result &= ~TIOCSER_TEMT;
1083
1084 return put_user(result, value);
1085}
1086
1087static int uart_tiocmget(struct tty_struct *tty)
1088{
1089 struct uart_state *state = tty->driver_data;
1090 struct tty_port *port = &state->port;
1091 struct uart_port *uport;
1092 int result = -EIO;
1093
1094 mutex_lock(&port->mutex);
1095 uport = uart_port_check(state);
1096 if (!uport)
1097 goto out;
1098
1099 if (!tty_io_error(tty)) {
1100 uart_port_lock_irq(uport);
1101 result = uport->mctrl;
1102 result |= uport->ops->get_mctrl(uport);
1103 uart_port_unlock_irq(uport);
1104 }
1105out:
1106 mutex_unlock(&port->mutex);
1107 return result;
1108}
1109
1110static int
1111uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
1112{
1113 struct uart_state *state = tty->driver_data;
1114 struct tty_port *port = &state->port;
1115 struct uart_port *uport;
1116 int ret = -EIO;
1117
1118 mutex_lock(&port->mutex);
1119 uport = uart_port_check(state);
1120 if (!uport)
1121 goto out;
1122
1123 if (!tty_io_error(tty)) {
1124 uart_update_mctrl(uport, set, clear);
1125 ret = 0;
1126 }
1127out:
1128 mutex_unlock(&port->mutex);
1129 return ret;
1130}
1131
1132static int uart_break_ctl(struct tty_struct *tty, int break_state)
1133{
1134 struct uart_state *state = tty->driver_data;
1135 struct tty_port *port = &state->port;
1136 struct uart_port *uport;
1137 int ret = -EIO;
1138
1139 mutex_lock(&port->mutex);
1140 uport = uart_port_check(state);
1141 if (!uport)
1142 goto out;
1143
1144 if (uport->type != PORT_UNKNOWN && uport->ops->break_ctl)
1145 uport->ops->break_ctl(uport, break_state);
1146 ret = 0;
1147out:
1148 mutex_unlock(&port->mutex);
1149 return ret;
1150}
1151
1152static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state)
1153{
1154 struct tty_port *port = &state->port;
1155 struct uart_port *uport;
1156 int flags, ret;
1157
1158 if (!capable(CAP_SYS_ADMIN))
1159 return -EPERM;
1160
1161 /*
1162 * Take the per-port semaphore. This prevents count from
1163 * changing, and hence any extra opens of the port while
1164 * we're auto-configuring.
1165 */
1166 if (mutex_lock_interruptible(&port->mutex))
1167 return -ERESTARTSYS;
1168
1169 uport = uart_port_check(state);
1170 if (!uport) {
1171 ret = -EIO;
1172 goto out;
1173 }
1174
1175 ret = -EBUSY;
1176 if (tty_port_users(port) == 1) {
1177 uart_shutdown(tty, state);
1178
1179 /*
1180 * If we already have a port type configured,
1181 * we must release its resources.
1182 */
1183 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
1184 uport->ops->release_port(uport);
1185
1186 flags = UART_CONFIG_TYPE;
1187 if (uport->flags & UPF_AUTO_IRQ)
1188 flags |= UART_CONFIG_IRQ;
1189
1190 /*
1191 * This will claim the ports resources if
1192 * a port is found.
1193 */
1194 uport->ops->config_port(uport, flags);
1195
1196 ret = uart_startup(tty, state, true);
1197 if (ret == 0)
1198 tty_port_set_initialized(port, true);
1199 if (ret > 0)
1200 ret = 0;
1201 }
1202out:
1203 mutex_unlock(&port->mutex);
1204 return ret;
1205}
1206
1207static void uart_enable_ms(struct uart_port *uport)
1208{
1209 /*
1210 * Force modem status interrupts on
1211 */
1212 if (uport->ops->enable_ms)
1213 uport->ops->enable_ms(uport);
1214}
1215
1216/*
1217 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1218 * - mask passed in arg for lines of interest
1219 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1220 * Caller should use TIOCGICOUNT to see which one it was
1221 *
1222 * FIXME: This wants extracting into a common all driver implementation
1223 * of TIOCMWAIT using tty_port.
1224 */
1225static int uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1226{
1227 struct uart_port *uport;
1228 struct tty_port *port = &state->port;
1229 DECLARE_WAITQUEUE(wait, current);
1230 struct uart_icount cprev, cnow;
1231 int ret;
1232
1233 /*
1234 * note the counters on entry
1235 */
1236 uport = uart_port_ref(state);
1237 if (!uport)
1238 return -EIO;
1239 uart_port_lock_irq(uport);
1240 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1241 uart_enable_ms(uport);
1242 uart_port_unlock_irq(uport);
1243
1244 add_wait_queue(&port->delta_msr_wait, &wait);
1245 for (;;) {
1246 uart_port_lock_irq(uport);
1247 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1248 uart_port_unlock_irq(uport);
1249
1250 set_current_state(TASK_INTERRUPTIBLE);
1251
1252 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1253 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1254 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1255 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1256 ret = 0;
1257 break;
1258 }
1259
1260 schedule();
1261
1262 /* see if a signal did it */
1263 if (signal_pending(current)) {
1264 ret = -ERESTARTSYS;
1265 break;
1266 }
1267
1268 cprev = cnow;
1269 }
1270 __set_current_state(TASK_RUNNING);
1271 remove_wait_queue(&port->delta_msr_wait, &wait);
1272 uart_port_deref(uport);
1273
1274 return ret;
1275}
1276
1277/*
1278 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1279 * Return: write counters to the user passed counter struct
1280 * NB: both 1->0 and 0->1 transitions are counted except for
1281 * RI where only 0->1 is counted.
1282 */
1283static int uart_get_icount(struct tty_struct *tty,
1284 struct serial_icounter_struct *icount)
1285{
1286 struct uart_state *state = tty->driver_data;
1287 struct uart_icount cnow;
1288 struct uart_port *uport;
1289
1290 uport = uart_port_ref(state);
1291 if (!uport)
1292 return -EIO;
1293 uart_port_lock_irq(uport);
1294 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1295 uart_port_unlock_irq(uport);
1296 uart_port_deref(uport);
1297
1298 icount->cts = cnow.cts;
1299 icount->dsr = cnow.dsr;
1300 icount->rng = cnow.rng;
1301 icount->dcd = cnow.dcd;
1302 icount->rx = cnow.rx;
1303 icount->tx = cnow.tx;
1304 icount->frame = cnow.frame;
1305 icount->overrun = cnow.overrun;
1306 icount->parity = cnow.parity;
1307 icount->brk = cnow.brk;
1308 icount->buf_overrun = cnow.buf_overrun;
1309
1310 return 0;
1311}
1312
1313#define SER_RS485_LEGACY_FLAGS (SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | \
1314 SER_RS485_RTS_AFTER_SEND | SER_RS485_RX_DURING_TX | \
1315 SER_RS485_TERMINATE_BUS)
1316
1317static int uart_check_rs485_flags(struct uart_port *port, struct serial_rs485 *rs485)
1318{
1319 u32 flags = rs485->flags;
1320
1321 /* Don't return -EINVAL for unsupported legacy flags */
1322 flags &= ~SER_RS485_LEGACY_FLAGS;
1323
1324 /*
1325 * For any bit outside of the legacy ones that is not supported by
1326 * the driver, return -EINVAL.
1327 */
1328 if (flags & ~port->rs485_supported.flags)
1329 return -EINVAL;
1330
1331 /* Asking for address w/o addressing mode? */
1332 if (!(rs485->flags & SER_RS485_ADDRB) &&
1333 (rs485->flags & (SER_RS485_ADDR_RECV|SER_RS485_ADDR_DEST)))
1334 return -EINVAL;
1335
1336 /* Address given but not enabled? */
1337 if (!(rs485->flags & SER_RS485_ADDR_RECV) && rs485->addr_recv)
1338 return -EINVAL;
1339 if (!(rs485->flags & SER_RS485_ADDR_DEST) && rs485->addr_dest)
1340 return -EINVAL;
1341
1342 return 0;
1343}
1344
1345static void uart_sanitize_serial_rs485_delays(struct uart_port *port,
1346 struct serial_rs485 *rs485)
1347{
1348 if (!port->rs485_supported.delay_rts_before_send) {
1349 if (rs485->delay_rts_before_send) {
1350 dev_warn_ratelimited(port->dev,
1351 "%s (%d): RTS delay before sending not supported\n",
1352 port->name, port->line);
1353 }
1354 rs485->delay_rts_before_send = 0;
1355 } else if (rs485->delay_rts_before_send > RS485_MAX_RTS_DELAY) {
1356 rs485->delay_rts_before_send = RS485_MAX_RTS_DELAY;
1357 dev_warn_ratelimited(port->dev,
1358 "%s (%d): RTS delay before sending clamped to %u ms\n",
1359 port->name, port->line, rs485->delay_rts_before_send);
1360 }
1361
1362 if (!port->rs485_supported.delay_rts_after_send) {
1363 if (rs485->delay_rts_after_send) {
1364 dev_warn_ratelimited(port->dev,
1365 "%s (%d): RTS delay after sending not supported\n",
1366 port->name, port->line);
1367 }
1368 rs485->delay_rts_after_send = 0;
1369 } else if (rs485->delay_rts_after_send > RS485_MAX_RTS_DELAY) {
1370 rs485->delay_rts_after_send = RS485_MAX_RTS_DELAY;
1371 dev_warn_ratelimited(port->dev,
1372 "%s (%d): RTS delay after sending clamped to %u ms\n",
1373 port->name, port->line, rs485->delay_rts_after_send);
1374 }
1375}
1376
1377static void uart_sanitize_serial_rs485(struct uart_port *port, struct serial_rs485 *rs485)
1378{
1379 u32 supported_flags = port->rs485_supported.flags;
1380
1381 if (!(rs485->flags & SER_RS485_ENABLED)) {
1382 memset(rs485, 0, sizeof(*rs485));
1383 return;
1384 }
1385
1386 /* Clear other RS485 flags but SER_RS485_TERMINATE_BUS and return if enabling RS422 */
1387 if (rs485->flags & SER_RS485_MODE_RS422) {
1388 rs485->flags &= (SER_RS485_ENABLED | SER_RS485_MODE_RS422 | SER_RS485_TERMINATE_BUS);
1389 return;
1390 }
1391
1392 rs485->flags &= supported_flags;
1393
1394 /* Pick sane settings if the user hasn't */
1395 if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
1396 !(rs485->flags & SER_RS485_RTS_AFTER_SEND)) {
1397 if (supported_flags & SER_RS485_RTS_ON_SEND) {
1398 rs485->flags |= SER_RS485_RTS_ON_SEND;
1399 rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
1400
1401 dev_warn_ratelimited(port->dev,
1402 "%s (%d): invalid RTS setting, using RTS_ON_SEND instead\n",
1403 port->name, port->line);
1404 } else {
1405 rs485->flags |= SER_RS485_RTS_AFTER_SEND;
1406 rs485->flags &= ~SER_RS485_RTS_ON_SEND;
1407
1408 dev_warn_ratelimited(port->dev,
1409 "%s (%d): invalid RTS setting, using RTS_AFTER_SEND instead\n",
1410 port->name, port->line);
1411 }
1412 }
1413
1414 uart_sanitize_serial_rs485_delays(port, rs485);
1415
1416 /* Return clean padding area to userspace */
1417 memset(rs485->padding0, 0, sizeof(rs485->padding0));
1418 memset(rs485->padding1, 0, sizeof(rs485->padding1));
1419}
1420
1421static void uart_set_rs485_termination(struct uart_port *port,
1422 const struct serial_rs485 *rs485)
1423{
1424 if (!(rs485->flags & SER_RS485_ENABLED))
1425 return;
1426
1427 gpiod_set_value_cansleep(port->rs485_term_gpio,
1428 !!(rs485->flags & SER_RS485_TERMINATE_BUS));
1429}
1430
1431static void uart_set_rs485_rx_during_tx(struct uart_port *port,
1432 const struct serial_rs485 *rs485)
1433{
1434 if (!(rs485->flags & SER_RS485_ENABLED))
1435 return;
1436
1437 gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio,
1438 !!(rs485->flags & SER_RS485_RX_DURING_TX));
1439}
1440
1441static int uart_rs485_config(struct uart_port *port)
1442{
1443 struct serial_rs485 *rs485 = &port->rs485;
1444 unsigned long flags;
1445 int ret;
1446
1447 if (!(rs485->flags & SER_RS485_ENABLED))
1448 return 0;
1449
1450 uart_sanitize_serial_rs485(port, rs485);
1451 uart_set_rs485_termination(port, rs485);
1452 uart_set_rs485_rx_during_tx(port, rs485);
1453
1454 uart_port_lock_irqsave(port, &flags);
1455 ret = port->rs485_config(port, NULL, rs485);
1456 uart_port_unlock_irqrestore(port, flags);
1457 if (ret) {
1458 memset(rs485, 0, sizeof(*rs485));
1459 /* unset GPIOs */
1460 gpiod_set_value_cansleep(port->rs485_term_gpio, 0);
1461 gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, 0);
1462 }
1463
1464 return ret;
1465}
1466
1467static int uart_get_rs485_config(struct uart_port *port,
1468 struct serial_rs485 __user *rs485)
1469{
1470 unsigned long flags;
1471 struct serial_rs485 aux;
1472
1473 uart_port_lock_irqsave(port, &flags);
1474 aux = port->rs485;
1475 uart_port_unlock_irqrestore(port, flags);
1476
1477 if (copy_to_user(rs485, &aux, sizeof(aux)))
1478 return -EFAULT;
1479
1480 return 0;
1481}
1482
1483static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port,
1484 struct serial_rs485 __user *rs485_user)
1485{
1486 struct serial_rs485 rs485;
1487 int ret;
1488 unsigned long flags;
1489
1490 if (!(port->rs485_supported.flags & SER_RS485_ENABLED))
1491 return -ENOTTY;
1492
1493 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1494 return -EFAULT;
1495
1496 ret = uart_check_rs485_flags(port, &rs485);
1497 if (ret)
1498 return ret;
1499 uart_sanitize_serial_rs485(port, &rs485);
1500 uart_set_rs485_termination(port, &rs485);
1501 uart_set_rs485_rx_during_tx(port, &rs485);
1502
1503 uart_port_lock_irqsave(port, &flags);
1504 ret = port->rs485_config(port, &tty->termios, &rs485);
1505 if (!ret) {
1506 port->rs485 = rs485;
1507
1508 /* Reset RTS and other mctrl lines when disabling RS485 */
1509 if (!(rs485.flags & SER_RS485_ENABLED))
1510 port->ops->set_mctrl(port, port->mctrl);
1511 }
1512 uart_port_unlock_irqrestore(port, flags);
1513 if (ret) {
1514 /* restore old GPIO settings */
1515 gpiod_set_value_cansleep(port->rs485_term_gpio,
1516 !!(port->rs485.flags & SER_RS485_TERMINATE_BUS));
1517 gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio,
1518 !!(port->rs485.flags & SER_RS485_RX_DURING_TX));
1519 return ret;
1520 }
1521
1522 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1523 return -EFAULT;
1524
1525 return 0;
1526}
1527
1528static int uart_get_iso7816_config(struct uart_port *port,
1529 struct serial_iso7816 __user *iso7816)
1530{
1531 unsigned long flags;
1532 struct serial_iso7816 aux;
1533
1534 if (!port->iso7816_config)
1535 return -ENOTTY;
1536
1537 uart_port_lock_irqsave(port, &flags);
1538 aux = port->iso7816;
1539 uart_port_unlock_irqrestore(port, flags);
1540
1541 if (copy_to_user(iso7816, &aux, sizeof(aux)))
1542 return -EFAULT;
1543
1544 return 0;
1545}
1546
1547static int uart_set_iso7816_config(struct uart_port *port,
1548 struct serial_iso7816 __user *iso7816_user)
1549{
1550 struct serial_iso7816 iso7816;
1551 int i, ret;
1552 unsigned long flags;
1553
1554 if (!port->iso7816_config)
1555 return -ENOTTY;
1556
1557 if (copy_from_user(&iso7816, iso7816_user, sizeof(*iso7816_user)))
1558 return -EFAULT;
1559
1560 /*
1561 * There are 5 words reserved for future use. Check that userspace
1562 * doesn't put stuff in there to prevent breakages in the future.
1563 */
1564 for (i = 0; i < ARRAY_SIZE(iso7816.reserved); i++)
1565 if (iso7816.reserved[i])
1566 return -EINVAL;
1567
1568 uart_port_lock_irqsave(port, &flags);
1569 ret = port->iso7816_config(port, &iso7816);
1570 uart_port_unlock_irqrestore(port, flags);
1571 if (ret)
1572 return ret;
1573
1574 if (copy_to_user(iso7816_user, &port->iso7816, sizeof(port->iso7816)))
1575 return -EFAULT;
1576
1577 return 0;
1578}
1579
1580/*
1581 * Called via sys_ioctl. We can use spin_lock_irq() here.
1582 */
1583static int
1584uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
1585{
1586 struct uart_state *state = tty->driver_data;
1587 struct tty_port *port = &state->port;
1588 struct uart_port *uport;
1589 void __user *uarg = (void __user *)arg;
1590 int ret = -ENOIOCTLCMD;
1591
1592
1593 /*
1594 * These ioctls don't rely on the hardware to be present.
1595 */
1596 switch (cmd) {
1597 case TIOCSERCONFIG:
1598 down_write(&tty->termios_rwsem);
1599 ret = uart_do_autoconfig(tty, state);
1600 up_write(&tty->termios_rwsem);
1601 break;
1602 }
1603
1604 if (ret != -ENOIOCTLCMD)
1605 goto out;
1606
1607 if (tty_io_error(tty)) {
1608 ret = -EIO;
1609 goto out;
1610 }
1611
1612 /*
1613 * The following should only be used when hardware is present.
1614 */
1615 switch (cmd) {
1616 case TIOCMIWAIT:
1617 ret = uart_wait_modem_status(state, arg);
1618 break;
1619 }
1620
1621 if (ret != -ENOIOCTLCMD)
1622 goto out;
1623
1624 /* rs485_config requires more locking than others */
1625 if (cmd == TIOCSRS485)
1626 down_write(&tty->termios_rwsem);
1627
1628 mutex_lock(&port->mutex);
1629 uport = uart_port_check(state);
1630
1631 if (!uport || tty_io_error(tty)) {
1632 ret = -EIO;
1633 goto out_up;
1634 }
1635
1636 /*
1637 * All these rely on hardware being present and need to be
1638 * protected against the tty being hung up.
1639 */
1640
1641 switch (cmd) {
1642 case TIOCSERGETLSR: /* Get line status register */
1643 ret = uart_get_lsr_info(tty, state, uarg);
1644 break;
1645
1646 case TIOCGRS485:
1647 ret = uart_get_rs485_config(uport, uarg);
1648 break;
1649
1650 case TIOCSRS485:
1651 ret = uart_set_rs485_config(tty, uport, uarg);
1652 break;
1653
1654 case TIOCSISO7816:
1655 ret = uart_set_iso7816_config(state->uart_port, uarg);
1656 break;
1657
1658 case TIOCGISO7816:
1659 ret = uart_get_iso7816_config(state->uart_port, uarg);
1660 break;
1661 default:
1662 if (uport->ops->ioctl)
1663 ret = uport->ops->ioctl(uport, cmd, arg);
1664 break;
1665 }
1666out_up:
1667 mutex_unlock(&port->mutex);
1668 if (cmd == TIOCSRS485)
1669 up_write(&tty->termios_rwsem);
1670out:
1671 return ret;
1672}
1673
1674static void uart_set_ldisc(struct tty_struct *tty)
1675{
1676 struct uart_state *state = tty->driver_data;
1677 struct uart_port *uport;
1678 struct tty_port *port = &state->port;
1679
1680 if (!tty_port_initialized(port))
1681 return;
1682
1683 mutex_lock(&state->port.mutex);
1684 uport = uart_port_check(state);
1685 if (uport && uport->ops->set_ldisc)
1686 uport->ops->set_ldisc(uport, &tty->termios);
1687 mutex_unlock(&state->port.mutex);
1688}
1689
1690static void uart_set_termios(struct tty_struct *tty,
1691 const struct ktermios *old_termios)
1692{
1693 struct uart_state *state = tty->driver_data;
1694 struct uart_port *uport;
1695 unsigned int cflag = tty->termios.c_cflag;
1696 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1697 bool sw_changed = false;
1698
1699 mutex_lock(&state->port.mutex);
1700 uport = uart_port_check(state);
1701 if (!uport)
1702 goto out;
1703
1704 /*
1705 * Drivers doing software flow control also need to know
1706 * about changes to these input settings.
1707 */
1708 if (uport->flags & UPF_SOFT_FLOW) {
1709 iflag_mask |= IXANY|IXON|IXOFF;
1710 sw_changed =
1711 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1712 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1713 }
1714
1715 /*
1716 * These are the bits that are used to setup various
1717 * flags in the low level driver. We can ignore the Bfoo
1718 * bits in c_cflag; c_[io]speed will always be set
1719 * appropriately by set_termios() in tty_ioctl.c
1720 */
1721 if ((cflag ^ old_termios->c_cflag) == 0 &&
1722 tty->termios.c_ospeed == old_termios->c_ospeed &&
1723 tty->termios.c_ispeed == old_termios->c_ispeed &&
1724 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1725 !sw_changed) {
1726 goto out;
1727 }
1728
1729 uart_change_line_settings(tty, state, old_termios);
1730 /* reload cflag from termios; port driver may have overridden flags */
1731 cflag = tty->termios.c_cflag;
1732
1733 /* Handle transition to B0 status */
1734 if (((old_termios->c_cflag & CBAUD) != B0) && ((cflag & CBAUD) == B0))
1735 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1736 /* Handle transition away from B0 status */
1737 else if (((old_termios->c_cflag & CBAUD) == B0) && ((cflag & CBAUD) != B0)) {
1738 unsigned int mask = TIOCM_DTR;
1739
1740 if (!(cflag & CRTSCTS) || !tty_throttled(tty))
1741 mask |= TIOCM_RTS;
1742 uart_set_mctrl(uport, mask);
1743 }
1744out:
1745 mutex_unlock(&state->port.mutex);
1746}
1747
1748/*
1749 * Calls to uart_close() are serialised via the tty_lock in
1750 * drivers/tty/tty_io.c:tty_release()
1751 * drivers/tty/tty_io.c:do_tty_hangup()
1752 */
1753static void uart_close(struct tty_struct *tty, struct file *filp)
1754{
1755 struct uart_state *state = tty->driver_data;
1756
1757 if (!state) {
1758 struct uart_driver *drv = tty->driver->driver_state;
1759 struct tty_port *port;
1760
1761 state = drv->state + tty->index;
1762 port = &state->port;
1763 spin_lock_irq(&port->lock);
1764 --port->count;
1765 spin_unlock_irq(&port->lock);
1766 return;
1767 }
1768
1769 pr_debug("uart_close(%d) called\n", tty->index);
1770
1771 tty_port_close(tty->port, tty, filp);
1772}
1773
1774static void uart_tty_port_shutdown(struct tty_port *port)
1775{
1776 struct uart_state *state = container_of(port, struct uart_state, port);
1777 struct uart_port *uport = uart_port_check(state);
1778 char *buf;
1779
1780 /*
1781 * At this point, we stop accepting input. To do this, we
1782 * disable the receive line status interrupts.
1783 */
1784 if (WARN(!uport, "detached port still initialized!\n"))
1785 return;
1786
1787 uart_port_lock_irq(uport);
1788 uport->ops->stop_rx(uport);
1789 uart_port_unlock_irq(uport);
1790
1791 serial_base_port_shutdown(uport);
1792 uart_port_shutdown(port);
1793
1794 /*
1795 * It's possible for shutdown to be called after suspend if we get
1796 * a DCD drop (hangup) at just the right time. Clear suspended bit so
1797 * we don't try to resume a port that has been shutdown.
1798 */
1799 tty_port_set_suspended(port, false);
1800
1801 /*
1802 * Free the transmit buffer.
1803 */
1804 uart_port_lock_irq(uport);
1805 uart_circ_clear(&state->xmit);
1806 buf = state->xmit.buf;
1807 state->xmit.buf = NULL;
1808 uart_port_unlock_irq(uport);
1809
1810 free_page((unsigned long)buf);
1811
1812 uart_change_pm(state, UART_PM_STATE_OFF);
1813}
1814
1815static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1816{
1817 struct uart_state *state = tty->driver_data;
1818 struct uart_port *port;
1819 unsigned long char_time, expire, fifo_timeout;
1820
1821 port = uart_port_ref(state);
1822 if (!port)
1823 return;
1824
1825 if (port->type == PORT_UNKNOWN || port->fifosize == 0) {
1826 uart_port_deref(port);
1827 return;
1828 }
1829
1830 /*
1831 * Set the check interval to be 1/5 of the estimated time to
1832 * send a single character, and make it at least 1. The check
1833 * interval should also be less than the timeout.
1834 *
1835 * Note: we have to use pretty tight timings here to satisfy
1836 * the NIST-PCTS.
1837 */
1838 char_time = max(nsecs_to_jiffies(port->frame_time / 5), 1UL);
1839
1840 if (timeout && timeout < char_time)
1841 char_time = timeout;
1842
1843 if (!uart_cts_enabled(port)) {
1844 /*
1845 * If the transmitter hasn't cleared in twice the approximate
1846 * amount of time to send the entire FIFO, it probably won't
1847 * ever clear. This assumes the UART isn't doing flow
1848 * control, which is currently the case. Hence, if it ever
1849 * takes longer than FIFO timeout, this is probably due to a
1850 * UART bug of some kind. So, we clamp the timeout parameter at
1851 * 2 * FIFO timeout.
1852 */
1853 fifo_timeout = uart_fifo_timeout(port);
1854 if (timeout == 0 || timeout > 2 * fifo_timeout)
1855 timeout = 2 * fifo_timeout;
1856 }
1857
1858 expire = jiffies + timeout;
1859
1860 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1861 port->line, jiffies, expire);
1862
1863 /*
1864 * Check whether the transmitter is empty every 'char_time'.
1865 * 'timeout' / 'expire' give us the maximum amount of time
1866 * we wait.
1867 */
1868 while (!port->ops->tx_empty(port)) {
1869 msleep_interruptible(jiffies_to_msecs(char_time));
1870 if (signal_pending(current))
1871 break;
1872 if (timeout && time_after(jiffies, expire))
1873 break;
1874 }
1875 uart_port_deref(port);
1876}
1877
1878/*
1879 * Calls to uart_hangup() are serialised by the tty_lock in
1880 * drivers/tty/tty_io.c:do_tty_hangup()
1881 * This runs from a workqueue and can sleep for a _short_ time only.
1882 */
1883static void uart_hangup(struct tty_struct *tty)
1884{
1885 struct uart_state *state = tty->driver_data;
1886 struct tty_port *port = &state->port;
1887 struct uart_port *uport;
1888 unsigned long flags;
1889
1890 pr_debug("uart_hangup(%d)\n", tty->index);
1891
1892 mutex_lock(&port->mutex);
1893 uport = uart_port_check(state);
1894 WARN(!uport, "hangup of detached port!\n");
1895
1896 if (tty_port_active(port)) {
1897 uart_flush_buffer(tty);
1898 uart_shutdown(tty, state);
1899 spin_lock_irqsave(&port->lock, flags);
1900 port->count = 0;
1901 spin_unlock_irqrestore(&port->lock, flags);
1902 tty_port_set_active(port, false);
1903 tty_port_tty_set(port, NULL);
1904 if (uport && !uart_console(uport))
1905 uart_change_pm(state, UART_PM_STATE_OFF);
1906 wake_up_interruptible(&port->open_wait);
1907 wake_up_interruptible(&port->delta_msr_wait);
1908 }
1909 mutex_unlock(&port->mutex);
1910}
1911
1912/* uport == NULL if uart_port has already been removed */
1913static void uart_port_shutdown(struct tty_port *port)
1914{
1915 struct uart_state *state = container_of(port, struct uart_state, port);
1916 struct uart_port *uport = uart_port_check(state);
1917
1918 /*
1919 * clear delta_msr_wait queue to avoid mem leaks: we may free
1920 * the irq here so the queue might never be woken up. Note
1921 * that we won't end up waiting on delta_msr_wait again since
1922 * any outstanding file descriptors should be pointing at
1923 * hung_up_tty_fops now.
1924 */
1925 wake_up_interruptible(&port->delta_msr_wait);
1926
1927 if (uport) {
1928 /* Free the IRQ and disable the port. */
1929 uport->ops->shutdown(uport);
1930
1931 /* Ensure that the IRQ handler isn't running on another CPU. */
1932 synchronize_irq(uport->irq);
1933 }
1934}
1935
1936static bool uart_carrier_raised(struct tty_port *port)
1937{
1938 struct uart_state *state = container_of(port, struct uart_state, port);
1939 struct uart_port *uport;
1940 int mctrl;
1941
1942 uport = uart_port_ref(state);
1943 /*
1944 * Should never observe uport == NULL since checks for hangup should
1945 * abort the tty_port_block_til_ready() loop before checking for carrier
1946 * raised -- but report carrier raised if it does anyway so open will
1947 * continue and not sleep
1948 */
1949 if (WARN_ON(!uport))
1950 return true;
1951 uart_port_lock_irq(uport);
1952 uart_enable_ms(uport);
1953 mctrl = uport->ops->get_mctrl(uport);
1954 uart_port_unlock_irq(uport);
1955 uart_port_deref(uport);
1956
1957 return mctrl & TIOCM_CAR;
1958}
1959
1960static void uart_dtr_rts(struct tty_port *port, bool active)
1961{
1962 struct uart_state *state = container_of(port, struct uart_state, port);
1963 struct uart_port *uport;
1964
1965 uport = uart_port_ref(state);
1966 if (!uport)
1967 return;
1968 uart_port_dtr_rts(uport, active);
1969 uart_port_deref(uport);
1970}
1971
1972static int uart_install(struct tty_driver *driver, struct tty_struct *tty)
1973{
1974 struct uart_driver *drv = driver->driver_state;
1975 struct uart_state *state = drv->state + tty->index;
1976
1977 tty->driver_data = state;
1978
1979 return tty_standard_install(driver, tty);
1980}
1981
1982/*
1983 * Calls to uart_open are serialised by the tty_lock in
1984 * drivers/tty/tty_io.c:tty_open()
1985 * Note that if this fails, then uart_close() _will_ be called.
1986 *
1987 * In time, we want to scrap the "opening nonpresent ports"
1988 * behaviour and implement an alternative way for setserial
1989 * to set base addresses/ports/types. This will allow us to
1990 * get rid of a certain amount of extra tests.
1991 */
1992static int uart_open(struct tty_struct *tty, struct file *filp)
1993{
1994 struct uart_state *state = tty->driver_data;
1995 int retval;
1996
1997 retval = tty_port_open(&state->port, tty, filp);
1998 if (retval > 0)
1999 retval = 0;
2000
2001 return retval;
2002}
2003
2004static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
2005{
2006 struct uart_state *state = container_of(port, struct uart_state, port);
2007 struct uart_port *uport;
2008 int ret;
2009
2010 uport = uart_port_check(state);
2011 if (!uport || uport->flags & UPF_DEAD)
2012 return -ENXIO;
2013
2014 /*
2015 * Start up the serial port.
2016 */
2017 ret = uart_startup(tty, state, false);
2018 if (ret > 0)
2019 tty_port_set_active(port, true);
2020
2021 return ret;
2022}
2023
2024static const char *uart_type(struct uart_port *port)
2025{
2026 const char *str = NULL;
2027
2028 if (port->ops->type)
2029 str = port->ops->type(port);
2030
2031 if (!str)
2032 str = "unknown";
2033
2034 return str;
2035}
2036
2037#ifdef CONFIG_PROC_FS
2038
2039static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
2040{
2041 struct uart_state *state = drv->state + i;
2042 struct tty_port *port = &state->port;
2043 enum uart_pm_state pm_state;
2044 struct uart_port *uport;
2045 char stat_buf[32];
2046 unsigned int status;
2047 int mmio;
2048
2049 mutex_lock(&port->mutex);
2050 uport = uart_port_check(state);
2051 if (!uport)
2052 goto out;
2053
2054 mmio = uport->iotype >= UPIO_MEM;
2055 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
2056 uport->line, uart_type(uport),
2057 mmio ? "mmio:0x" : "port:",
2058 mmio ? (unsigned long long)uport->mapbase
2059 : (unsigned long long)uport->iobase,
2060 uport->irq);
2061
2062 if (uport->type == PORT_UNKNOWN) {
2063 seq_putc(m, '\n');
2064 goto out;
2065 }
2066
2067 if (capable(CAP_SYS_ADMIN)) {
2068 pm_state = state->pm_state;
2069 if (pm_state != UART_PM_STATE_ON)
2070 uart_change_pm(state, UART_PM_STATE_ON);
2071 uart_port_lock_irq(uport);
2072 status = uport->ops->get_mctrl(uport);
2073 uart_port_unlock_irq(uport);
2074 if (pm_state != UART_PM_STATE_ON)
2075 uart_change_pm(state, pm_state);
2076
2077 seq_printf(m, " tx:%d rx:%d",
2078 uport->icount.tx, uport->icount.rx);
2079 if (uport->icount.frame)
2080 seq_printf(m, " fe:%d", uport->icount.frame);
2081 if (uport->icount.parity)
2082 seq_printf(m, " pe:%d", uport->icount.parity);
2083 if (uport->icount.brk)
2084 seq_printf(m, " brk:%d", uport->icount.brk);
2085 if (uport->icount.overrun)
2086 seq_printf(m, " oe:%d", uport->icount.overrun);
2087 if (uport->icount.buf_overrun)
2088 seq_printf(m, " bo:%d", uport->icount.buf_overrun);
2089
2090#define INFOBIT(bit, str) \
2091 if (uport->mctrl & (bit)) \
2092 strncat(stat_buf, (str), sizeof(stat_buf) - \
2093 strlen(stat_buf) - 2)
2094#define STATBIT(bit, str) \
2095 if (status & (bit)) \
2096 strncat(stat_buf, (str), sizeof(stat_buf) - \
2097 strlen(stat_buf) - 2)
2098
2099 stat_buf[0] = '\0';
2100 stat_buf[1] = '\0';
2101 INFOBIT(TIOCM_RTS, "|RTS");
2102 STATBIT(TIOCM_CTS, "|CTS");
2103 INFOBIT(TIOCM_DTR, "|DTR");
2104 STATBIT(TIOCM_DSR, "|DSR");
2105 STATBIT(TIOCM_CAR, "|CD");
2106 STATBIT(TIOCM_RNG, "|RI");
2107 if (stat_buf[0])
2108 stat_buf[0] = ' ';
2109
2110 seq_puts(m, stat_buf);
2111 }
2112 seq_putc(m, '\n');
2113#undef STATBIT
2114#undef INFOBIT
2115out:
2116 mutex_unlock(&port->mutex);
2117}
2118
2119static int uart_proc_show(struct seq_file *m, void *v)
2120{
2121 struct tty_driver *ttydrv = m->private;
2122 struct uart_driver *drv = ttydrv->driver_state;
2123 int i;
2124
2125 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
2126 for (i = 0; i < drv->nr; i++)
2127 uart_line_info(m, drv, i);
2128 return 0;
2129}
2130#endif
2131
2132static void uart_port_spin_lock_init(struct uart_port *port)
2133{
2134 spin_lock_init(&port->lock);
2135 lockdep_set_class(&port->lock, &port_lock_key);
2136}
2137
2138#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
2139/**
2140 * uart_console_write - write a console message to a serial port
2141 * @port: the port to write the message
2142 * @s: array of characters
2143 * @count: number of characters in string to write
2144 * @putchar: function to write character to port
2145 */
2146void uart_console_write(struct uart_port *port, const char *s,
2147 unsigned int count,
2148 void (*putchar)(struct uart_port *, unsigned char))
2149{
2150 unsigned int i;
2151
2152 for (i = 0; i < count; i++, s++) {
2153 if (*s == '\n')
2154 putchar(port, '\r');
2155 putchar(port, *s);
2156 }
2157}
2158EXPORT_SYMBOL_GPL(uart_console_write);
2159
2160/**
2161 * uart_get_console - get uart port for console
2162 * @ports: ports to search in
2163 * @nr: number of @ports
2164 * @co: console to search for
2165 * Returns: uart_port for the console @co
2166 *
2167 * Check whether an invalid uart number has been specified (as @co->index), and
2168 * if so, search for the first available port that does have console support.
2169 */
2170struct uart_port * __init
2171uart_get_console(struct uart_port *ports, int nr, struct console *co)
2172{
2173 int idx = co->index;
2174
2175 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
2176 ports[idx].membase == NULL))
2177 for (idx = 0; idx < nr; idx++)
2178 if (ports[idx].iobase != 0 ||
2179 ports[idx].membase != NULL)
2180 break;
2181
2182 co->index = idx;
2183
2184 return ports + idx;
2185}
2186
2187/**
2188 * uart_parse_earlycon - Parse earlycon options
2189 * @p: ptr to 2nd field (ie., just beyond '<name>,')
2190 * @iotype: ptr for decoded iotype (out)
2191 * @addr: ptr for decoded mapbase/iobase (out)
2192 * @options: ptr for <options> field; %NULL if not present (out)
2193 *
2194 * Decodes earlycon kernel command line parameters of the form:
2195 * * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
2196 * * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
2197 *
2198 * The optional form:
2199 * * earlycon=<name>,0x<addr>,<options>
2200 * * console=<name>,0x<addr>,<options>
2201 *
2202 * is also accepted; the returned @iotype will be %UPIO_MEM.
2203 *
2204 * Returns: 0 on success or -%EINVAL on failure
2205 */
2206int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
2207 char **options)
2208{
2209 if (strncmp(p, "mmio,", 5) == 0) {
2210 *iotype = UPIO_MEM;
2211 p += 5;
2212 } else if (strncmp(p, "mmio16,", 7) == 0) {
2213 *iotype = UPIO_MEM16;
2214 p += 7;
2215 } else if (strncmp(p, "mmio32,", 7) == 0) {
2216 *iotype = UPIO_MEM32;
2217 p += 7;
2218 } else if (strncmp(p, "mmio32be,", 9) == 0) {
2219 *iotype = UPIO_MEM32BE;
2220 p += 9;
2221 } else if (strncmp(p, "mmio32native,", 13) == 0) {
2222 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
2223 UPIO_MEM32BE : UPIO_MEM32;
2224 p += 13;
2225 } else if (strncmp(p, "io,", 3) == 0) {
2226 *iotype = UPIO_PORT;
2227 p += 3;
2228 } else if (strncmp(p, "0x", 2) == 0) {
2229 *iotype = UPIO_MEM;
2230 } else {
2231 return -EINVAL;
2232 }
2233
2234 /*
2235 * Before you replace it with kstrtoull(), think about options separator
2236 * (',') it will not tolerate
2237 */
2238 *addr = simple_strtoull(p, NULL, 0);
2239 p = strchr(p, ',');
2240 if (p)
2241 p++;
2242
2243 *options = p;
2244 return 0;
2245}
2246EXPORT_SYMBOL_GPL(uart_parse_earlycon);
2247
2248/**
2249 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
2250 * @options: pointer to option string
2251 * @baud: pointer to an 'int' variable for the baud rate.
2252 * @parity: pointer to an 'int' variable for the parity.
2253 * @bits: pointer to an 'int' variable for the number of data bits.
2254 * @flow: pointer to an 'int' variable for the flow control character.
2255 *
2256 * uart_parse_options() decodes a string containing the serial console
2257 * options. The format of the string is <baud><parity><bits><flow>,
2258 * eg: 115200n8r
2259 */
2260void
2261uart_parse_options(const char *options, int *baud, int *parity,
2262 int *bits, int *flow)
2263{
2264 const char *s = options;
2265
2266 *baud = simple_strtoul(s, NULL, 10);
2267 while (*s >= '0' && *s <= '9')
2268 s++;
2269 if (*s)
2270 *parity = *s++;
2271 if (*s)
2272 *bits = *s++ - '0';
2273 if (*s)
2274 *flow = *s;
2275}
2276EXPORT_SYMBOL_GPL(uart_parse_options);
2277
2278/**
2279 * uart_set_options - setup the serial console parameters
2280 * @port: pointer to the serial ports uart_port structure
2281 * @co: console pointer
2282 * @baud: baud rate
2283 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
2284 * @bits: number of data bits
2285 * @flow: flow control character - 'r' (rts)
2286 *
2287 * Locking: Caller must hold console_list_lock in order to serialize
2288 * early initialization of the serial-console lock.
2289 */
2290int
2291uart_set_options(struct uart_port *port, struct console *co,
2292 int baud, int parity, int bits, int flow)
2293{
2294 struct ktermios termios;
2295 static struct ktermios dummy;
2296
2297 /*
2298 * Ensure that the serial-console lock is initialised early.
2299 *
2300 * Note that the console-registered check is needed because
2301 * kgdboc can call uart_set_options() for an already registered
2302 * console via tty_find_polling_driver() and uart_poll_init().
2303 */
2304 if (!uart_console_registered_locked(port) && !port->console_reinit)
2305 uart_port_spin_lock_init(port);
2306
2307 memset(&termios, 0, sizeof(struct ktermios));
2308
2309 termios.c_cflag |= CREAD | HUPCL | CLOCAL;
2310 tty_termios_encode_baud_rate(&termios, baud, baud);
2311
2312 if (bits == 7)
2313 termios.c_cflag |= CS7;
2314 else
2315 termios.c_cflag |= CS8;
2316
2317 switch (parity) {
2318 case 'o': case 'O':
2319 termios.c_cflag |= PARODD;
2320 fallthrough;
2321 case 'e': case 'E':
2322 termios.c_cflag |= PARENB;
2323 break;
2324 }
2325
2326 if (flow == 'r')
2327 termios.c_cflag |= CRTSCTS;
2328
2329 /*
2330 * some uarts on other side don't support no flow control.
2331 * So we set * DTR in host uart to make them happy
2332 */
2333 port->mctrl |= TIOCM_DTR;
2334
2335 port->ops->set_termios(port, &termios, &dummy);
2336 /*
2337 * Allow the setting of the UART parameters with a NULL console
2338 * too:
2339 */
2340 if (co) {
2341 co->cflag = termios.c_cflag;
2342 co->ispeed = termios.c_ispeed;
2343 co->ospeed = termios.c_ospeed;
2344 }
2345
2346 return 0;
2347}
2348EXPORT_SYMBOL_GPL(uart_set_options);
2349#endif /* CONFIG_SERIAL_CORE_CONSOLE */
2350
2351/**
2352 * uart_change_pm - set power state of the port
2353 *
2354 * @state: port descriptor
2355 * @pm_state: new state
2356 *
2357 * Locking: port->mutex has to be held
2358 */
2359static void uart_change_pm(struct uart_state *state,
2360 enum uart_pm_state pm_state)
2361{
2362 struct uart_port *port = uart_port_check(state);
2363
2364 if (state->pm_state != pm_state) {
2365 if (port && port->ops->pm)
2366 port->ops->pm(port, pm_state, state->pm_state);
2367 state->pm_state = pm_state;
2368 }
2369}
2370
2371struct uart_match {
2372 struct uart_port *port;
2373 struct uart_driver *driver;
2374};
2375
2376static int serial_match_port(struct device *dev, void *data)
2377{
2378 struct uart_match *match = data;
2379 struct tty_driver *tty_drv = match->driver->tty_driver;
2380 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
2381 match->port->line;
2382
2383 return dev->devt == devt; /* Actually, only one tty per port */
2384}
2385
2386int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
2387{
2388 struct uart_state *state = drv->state + uport->line;
2389 struct tty_port *port = &state->port;
2390 struct device *tty_dev;
2391 struct uart_match match = {uport, drv};
2392
2393 mutex_lock(&port->mutex);
2394
2395 tty_dev = device_find_child(&uport->port_dev->dev, &match, serial_match_port);
2396 if (tty_dev && device_may_wakeup(tty_dev)) {
2397 enable_irq_wake(uport->irq);
2398 put_device(tty_dev);
2399 mutex_unlock(&port->mutex);
2400 return 0;
2401 }
2402 put_device(tty_dev);
2403
2404 /*
2405 * Nothing to do if the console is not suspending
2406 * except stop_rx to prevent any asynchronous data
2407 * over RX line. However ensure that we will be
2408 * able to Re-start_rx later.
2409 */
2410 if (!console_suspend_enabled && uart_console(uport)) {
2411 if (uport->ops->start_rx) {
2412 uart_port_lock_irq(uport);
2413 uport->ops->stop_rx(uport);
2414 uart_port_unlock_irq(uport);
2415 }
2416 goto unlock;
2417 }
2418
2419 uport->suspended = 1;
2420
2421 if (tty_port_initialized(port)) {
2422 const struct uart_ops *ops = uport->ops;
2423 int tries;
2424 unsigned int mctrl;
2425
2426 tty_port_set_suspended(port, true);
2427 tty_port_set_initialized(port, false);
2428
2429 uart_port_lock_irq(uport);
2430 ops->stop_tx(uport);
2431 if (!(uport->rs485.flags & SER_RS485_ENABLED))
2432 ops->set_mctrl(uport, 0);
2433 /* save mctrl so it can be restored on resume */
2434 mctrl = uport->mctrl;
2435 uport->mctrl = 0;
2436 ops->stop_rx(uport);
2437 uart_port_unlock_irq(uport);
2438
2439 /*
2440 * Wait for the transmitter to empty.
2441 */
2442 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2443 msleep(10);
2444 if (!tries)
2445 dev_err(uport->dev, "%s: Unable to drain transmitter\n",
2446 uport->name);
2447
2448 ops->shutdown(uport);
2449 uport->mctrl = mctrl;
2450 }
2451
2452 /*
2453 * Disable the console device before suspending.
2454 */
2455 if (uart_console(uport))
2456 console_stop(uport->cons);
2457
2458 uart_change_pm(state, UART_PM_STATE_OFF);
2459unlock:
2460 mutex_unlock(&port->mutex);
2461
2462 return 0;
2463}
2464EXPORT_SYMBOL(uart_suspend_port);
2465
2466int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2467{
2468 struct uart_state *state = drv->state + uport->line;
2469 struct tty_port *port = &state->port;
2470 struct device *tty_dev;
2471 struct uart_match match = {uport, drv};
2472 struct ktermios termios;
2473
2474 mutex_lock(&port->mutex);
2475
2476 tty_dev = device_find_child(&uport->port_dev->dev, &match, serial_match_port);
2477 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2478 if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq))))
2479 disable_irq_wake(uport->irq);
2480 put_device(tty_dev);
2481 mutex_unlock(&port->mutex);
2482 return 0;
2483 }
2484 put_device(tty_dev);
2485 uport->suspended = 0;
2486
2487 /*
2488 * Re-enable the console device after suspending.
2489 */
2490 if (uart_console(uport)) {
2491 /*
2492 * First try to use the console cflag setting.
2493 */
2494 memset(&termios, 0, sizeof(struct ktermios));
2495 termios.c_cflag = uport->cons->cflag;
2496 termios.c_ispeed = uport->cons->ispeed;
2497 termios.c_ospeed = uport->cons->ospeed;
2498
2499 /*
2500 * If that's unset, use the tty termios setting.
2501 */
2502 if (port->tty && termios.c_cflag == 0)
2503 termios = port->tty->termios;
2504
2505 if (console_suspend_enabled)
2506 uart_change_pm(state, UART_PM_STATE_ON);
2507 uport->ops->set_termios(uport, &termios, NULL);
2508 if (!console_suspend_enabled && uport->ops->start_rx) {
2509 uart_port_lock_irq(uport);
2510 uport->ops->start_rx(uport);
2511 uart_port_unlock_irq(uport);
2512 }
2513 if (console_suspend_enabled)
2514 console_start(uport->cons);
2515 }
2516
2517 if (tty_port_suspended(port)) {
2518 const struct uart_ops *ops = uport->ops;
2519 int ret;
2520
2521 uart_change_pm(state, UART_PM_STATE_ON);
2522 uart_port_lock_irq(uport);
2523 if (!(uport->rs485.flags & SER_RS485_ENABLED))
2524 ops->set_mctrl(uport, 0);
2525 uart_port_unlock_irq(uport);
2526 if (console_suspend_enabled || !uart_console(uport)) {
2527 /* Protected by port mutex for now */
2528 struct tty_struct *tty = port->tty;
2529
2530 ret = ops->startup(uport);
2531 if (ret == 0) {
2532 if (tty)
2533 uart_change_line_settings(tty, state, NULL);
2534 uart_rs485_config(uport);
2535 uart_port_lock_irq(uport);
2536 if (!(uport->rs485.flags & SER_RS485_ENABLED))
2537 ops->set_mctrl(uport, uport->mctrl);
2538 ops->start_tx(uport);
2539 uart_port_unlock_irq(uport);
2540 tty_port_set_initialized(port, true);
2541 } else {
2542 /*
2543 * Failed to resume - maybe hardware went away?
2544 * Clear the "initialized" flag so we won't try
2545 * to call the low level drivers shutdown method.
2546 */
2547 uart_shutdown(tty, state);
2548 }
2549 }
2550
2551 tty_port_set_suspended(port, false);
2552 }
2553
2554 mutex_unlock(&port->mutex);
2555
2556 return 0;
2557}
2558EXPORT_SYMBOL(uart_resume_port);
2559
2560static inline void
2561uart_report_port(struct uart_driver *drv, struct uart_port *port)
2562{
2563 char address[64];
2564
2565 switch (port->iotype) {
2566 case UPIO_PORT:
2567 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2568 break;
2569 case UPIO_HUB6:
2570 snprintf(address, sizeof(address),
2571 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2572 break;
2573 case UPIO_MEM:
2574 case UPIO_MEM16:
2575 case UPIO_MEM32:
2576 case UPIO_MEM32BE:
2577 case UPIO_AU:
2578 case UPIO_TSI:
2579 snprintf(address, sizeof(address),
2580 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2581 break;
2582 default:
2583 strscpy(address, "*unknown*", sizeof(address));
2584 break;
2585 }
2586
2587 pr_info("%s%s%s at %s (irq = %d, base_baud = %d) is a %s\n",
2588 port->dev ? dev_name(port->dev) : "",
2589 port->dev ? ": " : "",
2590 port->name,
2591 address, port->irq, port->uartclk / 16, uart_type(port));
2592
2593 /* The magic multiplier feature is a bit obscure, so report it too. */
2594 if (port->flags & UPF_MAGIC_MULTIPLIER)
2595 pr_info("%s%s%s extra baud rates supported: %d, %d",
2596 port->dev ? dev_name(port->dev) : "",
2597 port->dev ? ": " : "",
2598 port->name,
2599 port->uartclk / 8, port->uartclk / 4);
2600}
2601
2602static void
2603uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2604 struct uart_port *port)
2605{
2606 unsigned int flags;
2607
2608 /*
2609 * If there isn't a port here, don't do anything further.
2610 */
2611 if (!port->iobase && !port->mapbase && !port->membase)
2612 return;
2613
2614 /*
2615 * Now do the auto configuration stuff. Note that config_port
2616 * is expected to claim the resources and map the port for us.
2617 */
2618 flags = 0;
2619 if (port->flags & UPF_AUTO_IRQ)
2620 flags |= UART_CONFIG_IRQ;
2621 if (port->flags & UPF_BOOT_AUTOCONF) {
2622 if (!(port->flags & UPF_FIXED_TYPE)) {
2623 port->type = PORT_UNKNOWN;
2624 flags |= UART_CONFIG_TYPE;
2625 }
2626 /* Synchronize with possible boot console. */
2627 if (uart_console(port))
2628 console_lock();
2629 port->ops->config_port(port, flags);
2630 if (uart_console(port))
2631 console_unlock();
2632 }
2633
2634 if (port->type != PORT_UNKNOWN) {
2635 unsigned long flags;
2636
2637 uart_report_port(drv, port);
2638
2639 /* Synchronize with possible boot console. */
2640 if (uart_console(port))
2641 console_lock();
2642
2643 /* Power up port for set_mctrl() */
2644 uart_change_pm(state, UART_PM_STATE_ON);
2645
2646 /*
2647 * Ensure that the modem control lines are de-activated.
2648 * keep the DTR setting that is set in uart_set_options()
2649 * We probably don't need a spinlock around this, but
2650 */
2651 uart_port_lock_irqsave(port, &flags);
2652 port->mctrl &= TIOCM_DTR;
2653 if (!(port->rs485.flags & SER_RS485_ENABLED))
2654 port->ops->set_mctrl(port, port->mctrl);
2655 uart_port_unlock_irqrestore(port, flags);
2656
2657 uart_rs485_config(port);
2658
2659 if (uart_console(port))
2660 console_unlock();
2661
2662 /*
2663 * If this driver supports console, and it hasn't been
2664 * successfully registered yet, try to re-register it.
2665 * It may be that the port was not available.
2666 */
2667 if (port->cons && !console_is_registered(port->cons))
2668 register_console(port->cons);
2669
2670 /*
2671 * Power down all ports by default, except the
2672 * console if we have one.
2673 */
2674 if (!uart_console(port))
2675 uart_change_pm(state, UART_PM_STATE_OFF);
2676 }
2677}
2678
2679#ifdef CONFIG_CONSOLE_POLL
2680
2681static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2682{
2683 struct uart_driver *drv = driver->driver_state;
2684 struct uart_state *state = drv->state + line;
2685 enum uart_pm_state pm_state;
2686 struct tty_port *tport;
2687 struct uart_port *port;
2688 int baud = 9600;
2689 int bits = 8;
2690 int parity = 'n';
2691 int flow = 'n';
2692 int ret = 0;
2693
2694 tport = &state->port;
2695 mutex_lock(&tport->mutex);
2696
2697 port = uart_port_check(state);
2698 if (!port || port->type == PORT_UNKNOWN ||
2699 !(port->ops->poll_get_char && port->ops->poll_put_char)) {
2700 ret = -1;
2701 goto out;
2702 }
2703
2704 pm_state = state->pm_state;
2705 uart_change_pm(state, UART_PM_STATE_ON);
2706
2707 if (port->ops->poll_init) {
2708 /*
2709 * We don't set initialized as we only initialized the hw,
2710 * e.g. state->xmit is still uninitialized.
2711 */
2712 if (!tty_port_initialized(tport))
2713 ret = port->ops->poll_init(port);
2714 }
2715
2716 if (!ret && options) {
2717 uart_parse_options(options, &baud, &parity, &bits, &flow);
2718 console_list_lock();
2719 ret = uart_set_options(port, NULL, baud, parity, bits, flow);
2720 console_list_unlock();
2721 }
2722out:
2723 if (ret)
2724 uart_change_pm(state, pm_state);
2725 mutex_unlock(&tport->mutex);
2726 return ret;
2727}
2728
2729static int uart_poll_get_char(struct tty_driver *driver, int line)
2730{
2731 struct uart_driver *drv = driver->driver_state;
2732 struct uart_state *state = drv->state + line;
2733 struct uart_port *port;
2734 int ret = -1;
2735
2736 port = uart_port_ref(state);
2737 if (port) {
2738 ret = port->ops->poll_get_char(port);
2739 uart_port_deref(port);
2740 }
2741
2742 return ret;
2743}
2744
2745static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2746{
2747 struct uart_driver *drv = driver->driver_state;
2748 struct uart_state *state = drv->state + line;
2749 struct uart_port *port;
2750
2751 port = uart_port_ref(state);
2752 if (!port)
2753 return;
2754
2755 if (ch == '\n')
2756 port->ops->poll_put_char(port, '\r');
2757 port->ops->poll_put_char(port, ch);
2758 uart_port_deref(port);
2759}
2760#endif
2761
2762static const struct tty_operations uart_ops = {
2763 .install = uart_install,
2764 .open = uart_open,
2765 .close = uart_close,
2766 .write = uart_write,
2767 .put_char = uart_put_char,
2768 .flush_chars = uart_flush_chars,
2769 .write_room = uart_write_room,
2770 .chars_in_buffer= uart_chars_in_buffer,
2771 .flush_buffer = uart_flush_buffer,
2772 .ioctl = uart_ioctl,
2773 .throttle = uart_throttle,
2774 .unthrottle = uart_unthrottle,
2775 .send_xchar = uart_send_xchar,
2776 .set_termios = uart_set_termios,
2777 .set_ldisc = uart_set_ldisc,
2778 .stop = uart_stop,
2779 .start = uart_start,
2780 .hangup = uart_hangup,
2781 .break_ctl = uart_break_ctl,
2782 .wait_until_sent= uart_wait_until_sent,
2783#ifdef CONFIG_PROC_FS
2784 .proc_show = uart_proc_show,
2785#endif
2786 .tiocmget = uart_tiocmget,
2787 .tiocmset = uart_tiocmset,
2788 .set_serial = uart_set_info_user,
2789 .get_serial = uart_get_info_user,
2790 .get_icount = uart_get_icount,
2791#ifdef CONFIG_CONSOLE_POLL
2792 .poll_init = uart_poll_init,
2793 .poll_get_char = uart_poll_get_char,
2794 .poll_put_char = uart_poll_put_char,
2795#endif
2796};
2797
2798static const struct tty_port_operations uart_port_ops = {
2799 .carrier_raised = uart_carrier_raised,
2800 .dtr_rts = uart_dtr_rts,
2801 .activate = uart_port_activate,
2802 .shutdown = uart_tty_port_shutdown,
2803};
2804
2805/**
2806 * uart_register_driver - register a driver with the uart core layer
2807 * @drv: low level driver structure
2808 *
2809 * Register a uart driver with the core driver. We in turn register with the
2810 * tty layer, and initialise the core driver per-port state.
2811 *
2812 * We have a proc file in /proc/tty/driver which is named after the normal
2813 * driver.
2814 *
2815 * @drv->port should be %NULL, and the per-port structures should be registered
2816 * using uart_add_one_port() after this call has succeeded.
2817 *
2818 * Locking: none, Interrupts: enabled
2819 */
2820int uart_register_driver(struct uart_driver *drv)
2821{
2822 struct tty_driver *normal;
2823 int i, retval = -ENOMEM;
2824
2825 BUG_ON(drv->state);
2826
2827 /*
2828 * Maybe we should be using a slab cache for this, especially if
2829 * we have a large number of ports to handle.
2830 */
2831 drv->state = kcalloc(drv->nr, sizeof(struct uart_state), GFP_KERNEL);
2832 if (!drv->state)
2833 goto out;
2834
2835 normal = tty_alloc_driver(drv->nr, TTY_DRIVER_REAL_RAW |
2836 TTY_DRIVER_DYNAMIC_DEV);
2837 if (IS_ERR(normal)) {
2838 retval = PTR_ERR(normal);
2839 goto out_kfree;
2840 }
2841
2842 drv->tty_driver = normal;
2843
2844 normal->driver_name = drv->driver_name;
2845 normal->name = drv->dev_name;
2846 normal->major = drv->major;
2847 normal->minor_start = drv->minor;
2848 normal->type = TTY_DRIVER_TYPE_SERIAL;
2849 normal->subtype = SERIAL_TYPE_NORMAL;
2850 normal->init_termios = tty_std_termios;
2851 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2852 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2853 normal->driver_state = drv;
2854 tty_set_operations(normal, &uart_ops);
2855
2856 /*
2857 * Initialise the UART state(s).
2858 */
2859 for (i = 0; i < drv->nr; i++) {
2860 struct uart_state *state = drv->state + i;
2861 struct tty_port *port = &state->port;
2862
2863 tty_port_init(port);
2864 port->ops = &uart_port_ops;
2865 }
2866
2867 retval = tty_register_driver(normal);
2868 if (retval >= 0)
2869 return retval;
2870
2871 for (i = 0; i < drv->nr; i++)
2872 tty_port_destroy(&drv->state[i].port);
2873 tty_driver_kref_put(normal);
2874out_kfree:
2875 kfree(drv->state);
2876out:
2877 return retval;
2878}
2879EXPORT_SYMBOL(uart_register_driver);
2880
2881/**
2882 * uart_unregister_driver - remove a driver from the uart core layer
2883 * @drv: low level driver structure
2884 *
2885 * Remove all references to a driver from the core driver. The low level
2886 * driver must have removed all its ports via the uart_remove_one_port() if it
2887 * registered them with uart_add_one_port(). (I.e. @drv->port is %NULL.)
2888 *
2889 * Locking: none, Interrupts: enabled
2890 */
2891void uart_unregister_driver(struct uart_driver *drv)
2892{
2893 struct tty_driver *p = drv->tty_driver;
2894 unsigned int i;
2895
2896 tty_unregister_driver(p);
2897 tty_driver_kref_put(p);
2898 for (i = 0; i < drv->nr; i++)
2899 tty_port_destroy(&drv->state[i].port);
2900 kfree(drv->state);
2901 drv->state = NULL;
2902 drv->tty_driver = NULL;
2903}
2904EXPORT_SYMBOL(uart_unregister_driver);
2905
2906struct tty_driver *uart_console_device(struct console *co, int *index)
2907{
2908 struct uart_driver *p = co->data;
2909 *index = co->index;
2910 return p->tty_driver;
2911}
2912EXPORT_SYMBOL_GPL(uart_console_device);
2913
2914static ssize_t uartclk_show(struct device *dev,
2915 struct device_attribute *attr, char *buf)
2916{
2917 struct serial_struct tmp;
2918 struct tty_port *port = dev_get_drvdata(dev);
2919
2920 uart_get_info(port, &tmp);
2921 return sprintf(buf, "%d\n", tmp.baud_base * 16);
2922}
2923
2924static ssize_t type_show(struct device *dev,
2925 struct device_attribute *attr, char *buf)
2926{
2927 struct serial_struct tmp;
2928 struct tty_port *port = dev_get_drvdata(dev);
2929
2930 uart_get_info(port, &tmp);
2931 return sprintf(buf, "%d\n", tmp.type);
2932}
2933
2934static ssize_t line_show(struct device *dev,
2935 struct device_attribute *attr, char *buf)
2936{
2937 struct serial_struct tmp;
2938 struct tty_port *port = dev_get_drvdata(dev);
2939
2940 uart_get_info(port, &tmp);
2941 return sprintf(buf, "%d\n", tmp.line);
2942}
2943
2944static ssize_t port_show(struct device *dev,
2945 struct device_attribute *attr, char *buf)
2946{
2947 struct serial_struct tmp;
2948 struct tty_port *port = dev_get_drvdata(dev);
2949 unsigned long ioaddr;
2950
2951 uart_get_info(port, &tmp);
2952 ioaddr = tmp.port;
2953 if (HIGH_BITS_OFFSET)
2954 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2955 return sprintf(buf, "0x%lX\n", ioaddr);
2956}
2957
2958static ssize_t irq_show(struct device *dev,
2959 struct device_attribute *attr, char *buf)
2960{
2961 struct serial_struct tmp;
2962 struct tty_port *port = dev_get_drvdata(dev);
2963
2964 uart_get_info(port, &tmp);
2965 return sprintf(buf, "%d\n", tmp.irq);
2966}
2967
2968static ssize_t flags_show(struct device *dev,
2969 struct device_attribute *attr, char *buf)
2970{
2971 struct serial_struct tmp;
2972 struct tty_port *port = dev_get_drvdata(dev);
2973
2974 uart_get_info(port, &tmp);
2975 return sprintf(buf, "0x%X\n", tmp.flags);
2976}
2977
2978static ssize_t xmit_fifo_size_show(struct device *dev,
2979 struct device_attribute *attr, char *buf)
2980{
2981 struct serial_struct tmp;
2982 struct tty_port *port = dev_get_drvdata(dev);
2983
2984 uart_get_info(port, &tmp);
2985 return sprintf(buf, "%d\n", tmp.xmit_fifo_size);
2986}
2987
2988static ssize_t close_delay_show(struct device *dev,
2989 struct device_attribute *attr, char *buf)
2990{
2991 struct serial_struct tmp;
2992 struct tty_port *port = dev_get_drvdata(dev);
2993
2994 uart_get_info(port, &tmp);
2995 return sprintf(buf, "%d\n", tmp.close_delay);
2996}
2997
2998static ssize_t closing_wait_show(struct device *dev,
2999 struct device_attribute *attr, char *buf)
3000{
3001 struct serial_struct tmp;
3002 struct tty_port *port = dev_get_drvdata(dev);
3003
3004 uart_get_info(port, &tmp);
3005 return sprintf(buf, "%d\n", tmp.closing_wait);
3006}
3007
3008static ssize_t custom_divisor_show(struct device *dev,
3009 struct device_attribute *attr, char *buf)
3010{
3011 struct serial_struct tmp;
3012 struct tty_port *port = dev_get_drvdata(dev);
3013
3014 uart_get_info(port, &tmp);
3015 return sprintf(buf, "%d\n", tmp.custom_divisor);
3016}
3017
3018static ssize_t io_type_show(struct device *dev,
3019 struct device_attribute *attr, char *buf)
3020{
3021 struct serial_struct tmp;
3022 struct tty_port *port = dev_get_drvdata(dev);
3023
3024 uart_get_info(port, &tmp);
3025 return sprintf(buf, "%d\n", tmp.io_type);
3026}
3027
3028static ssize_t iomem_base_show(struct device *dev,
3029 struct device_attribute *attr, char *buf)
3030{
3031 struct serial_struct tmp;
3032 struct tty_port *port = dev_get_drvdata(dev);
3033
3034 uart_get_info(port, &tmp);
3035 return sprintf(buf, "0x%lX\n", (unsigned long)tmp.iomem_base);
3036}
3037
3038static ssize_t iomem_reg_shift_show(struct device *dev,
3039 struct device_attribute *attr, char *buf)
3040{
3041 struct serial_struct tmp;
3042 struct tty_port *port = dev_get_drvdata(dev);
3043
3044 uart_get_info(port, &tmp);
3045 return sprintf(buf, "%d\n", tmp.iomem_reg_shift);
3046}
3047
3048static ssize_t console_show(struct device *dev,
3049 struct device_attribute *attr, char *buf)
3050{
3051 struct tty_port *port = dev_get_drvdata(dev);
3052 struct uart_state *state = container_of(port, struct uart_state, port);
3053 struct uart_port *uport;
3054 bool console = false;
3055
3056 mutex_lock(&port->mutex);
3057 uport = uart_port_check(state);
3058 if (uport)
3059 console = uart_console_registered(uport);
3060 mutex_unlock(&port->mutex);
3061
3062 return sprintf(buf, "%c\n", console ? 'Y' : 'N');
3063}
3064
3065static ssize_t console_store(struct device *dev,
3066 struct device_attribute *attr, const char *buf, size_t count)
3067{
3068 struct tty_port *port = dev_get_drvdata(dev);
3069 struct uart_state *state = container_of(port, struct uart_state, port);
3070 struct uart_port *uport;
3071 bool oldconsole, newconsole;
3072 int ret;
3073
3074 ret = kstrtobool(buf, &newconsole);
3075 if (ret)
3076 return ret;
3077
3078 mutex_lock(&port->mutex);
3079 uport = uart_port_check(state);
3080 if (uport) {
3081 oldconsole = uart_console_registered(uport);
3082 if (oldconsole && !newconsole) {
3083 ret = unregister_console(uport->cons);
3084 } else if (!oldconsole && newconsole) {
3085 if (uart_console(uport)) {
3086 uport->console_reinit = 1;
3087 register_console(uport->cons);
3088 } else {
3089 ret = -ENOENT;
3090 }
3091 }
3092 } else {
3093 ret = -ENXIO;
3094 }
3095 mutex_unlock(&port->mutex);
3096
3097 return ret < 0 ? ret : count;
3098}
3099
3100static DEVICE_ATTR_RO(uartclk);
3101static DEVICE_ATTR_RO(type);
3102static DEVICE_ATTR_RO(line);
3103static DEVICE_ATTR_RO(port);
3104static DEVICE_ATTR_RO(irq);
3105static DEVICE_ATTR_RO(flags);
3106static DEVICE_ATTR_RO(xmit_fifo_size);
3107static DEVICE_ATTR_RO(close_delay);
3108static DEVICE_ATTR_RO(closing_wait);
3109static DEVICE_ATTR_RO(custom_divisor);
3110static DEVICE_ATTR_RO(io_type);
3111static DEVICE_ATTR_RO(iomem_base);
3112static DEVICE_ATTR_RO(iomem_reg_shift);
3113static DEVICE_ATTR_RW(console);
3114
3115static struct attribute *tty_dev_attrs[] = {
3116 &dev_attr_uartclk.attr,
3117 &dev_attr_type.attr,
3118 &dev_attr_line.attr,
3119 &dev_attr_port.attr,
3120 &dev_attr_irq.attr,
3121 &dev_attr_flags.attr,
3122 &dev_attr_xmit_fifo_size.attr,
3123 &dev_attr_close_delay.attr,
3124 &dev_attr_closing_wait.attr,
3125 &dev_attr_custom_divisor.attr,
3126 &dev_attr_io_type.attr,
3127 &dev_attr_iomem_base.attr,
3128 &dev_attr_iomem_reg_shift.attr,
3129 &dev_attr_console.attr,
3130 NULL
3131};
3132
3133static const struct attribute_group tty_dev_attr_group = {
3134 .attrs = tty_dev_attrs,
3135};
3136
3137/**
3138 * serial_core_add_one_port - attach a driver-defined port structure
3139 * @drv: pointer to the uart low level driver structure for this port
3140 * @uport: uart port structure to use for this port.
3141 *
3142 * Context: task context, might sleep
3143 *
3144 * This allows the driver @drv to register its own uart_port structure with the
3145 * core driver. The main purpose is to allow the low level uart drivers to
3146 * expand uart_port, rather than having yet more levels of structures.
3147 * Caller must hold port_mutex.
3148 */
3149static int serial_core_add_one_port(struct uart_driver *drv, struct uart_port *uport)
3150{
3151 struct uart_state *state;
3152 struct tty_port *port;
3153 int ret = 0;
3154 struct device *tty_dev;
3155 int num_groups;
3156
3157 if (uport->line >= drv->nr)
3158 return -EINVAL;
3159
3160 state = drv->state + uport->line;
3161 port = &state->port;
3162
3163 mutex_lock(&port->mutex);
3164 if (state->uart_port) {
3165 ret = -EINVAL;
3166 goto out;
3167 }
3168
3169 /* Link the port to the driver state table and vice versa */
3170 atomic_set(&state->refcount, 1);
3171 init_waitqueue_head(&state->remove_wait);
3172 state->uart_port = uport;
3173 uport->state = state;
3174
3175 state->pm_state = UART_PM_STATE_UNDEFINED;
3176 uport->cons = drv->cons;
3177 uport->minor = drv->tty_driver->minor_start + uport->line;
3178 uport->name = kasprintf(GFP_KERNEL, "%s%d", drv->dev_name,
3179 drv->tty_driver->name_base + uport->line);
3180 if (!uport->name) {
3181 ret = -ENOMEM;
3182 goto out;
3183 }
3184
3185 /*
3186 * If this port is in use as a console then the spinlock is already
3187 * initialised.
3188 */
3189 if (!uart_console_registered(uport))
3190 uart_port_spin_lock_init(uport);
3191
3192 if (uport->cons && uport->dev)
3193 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
3194
3195 tty_port_link_device(port, drv->tty_driver, uport->line);
3196 uart_configure_port(drv, state, uport);
3197
3198 port->console = uart_console(uport);
3199
3200 num_groups = 2;
3201 if (uport->attr_group)
3202 num_groups++;
3203
3204 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
3205 GFP_KERNEL);
3206 if (!uport->tty_groups) {
3207 ret = -ENOMEM;
3208 goto out;
3209 }
3210 uport->tty_groups[0] = &tty_dev_attr_group;
3211 if (uport->attr_group)
3212 uport->tty_groups[1] = uport->attr_group;
3213
3214 /*
3215 * Register the port whether it's detected or not. This allows
3216 * setserial to be used to alter this port's parameters.
3217 */
3218 tty_dev = tty_port_register_device_attr_serdev(port, drv->tty_driver,
3219 uport->line, uport->dev, &uport->port_dev->dev, port,
3220 uport->tty_groups);
3221 if (!IS_ERR(tty_dev)) {
3222 device_set_wakeup_capable(tty_dev, 1);
3223 } else {
3224 dev_err(uport->dev, "Cannot register tty device on line %d\n",
3225 uport->line);
3226 }
3227
3228 out:
3229 mutex_unlock(&port->mutex);
3230
3231 return ret;
3232}
3233
3234/**
3235 * serial_core_remove_one_port - detach a driver defined port structure
3236 * @drv: pointer to the uart low level driver structure for this port
3237 * @uport: uart port structure for this port
3238 *
3239 * Context: task context, might sleep
3240 *
3241 * This unhooks (and hangs up) the specified port structure from the core
3242 * driver. No further calls will be made to the low-level code for this port.
3243 * Caller must hold port_mutex.
3244 */
3245static void serial_core_remove_one_port(struct uart_driver *drv,
3246 struct uart_port *uport)
3247{
3248 struct uart_state *state = drv->state + uport->line;
3249 struct tty_port *port = &state->port;
3250 struct uart_port *uart_port;
3251 struct tty_struct *tty;
3252
3253 mutex_lock(&port->mutex);
3254 uart_port = uart_port_check(state);
3255 if (uart_port != uport)
3256 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
3257 uart_port, uport);
3258
3259 if (!uart_port) {
3260 mutex_unlock(&port->mutex);
3261 return;
3262 }
3263 mutex_unlock(&port->mutex);
3264
3265 /*
3266 * Remove the devices from the tty layer
3267 */
3268 tty_port_unregister_device(port, drv->tty_driver, uport->line);
3269
3270 tty = tty_port_tty_get(port);
3271 if (tty) {
3272 tty_vhangup(port->tty);
3273 tty_kref_put(tty);
3274 }
3275
3276 /*
3277 * If the port is used as a console, unregister it
3278 */
3279 if (uart_console(uport))
3280 unregister_console(uport->cons);
3281
3282 /*
3283 * Free the port IO and memory resources, if any.
3284 */
3285 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
3286 uport->ops->release_port(uport);
3287 kfree(uport->tty_groups);
3288 kfree(uport->name);
3289
3290 /*
3291 * Indicate that there isn't a port here anymore.
3292 */
3293 uport->type = PORT_UNKNOWN;
3294 uport->port_dev = NULL;
3295
3296 mutex_lock(&port->mutex);
3297 WARN_ON(atomic_dec_return(&state->refcount) < 0);
3298 wait_event(state->remove_wait, !atomic_read(&state->refcount));
3299 state->uart_port = NULL;
3300 mutex_unlock(&port->mutex);
3301}
3302
3303/**
3304 * uart_match_port - are the two ports equivalent?
3305 * @port1: first port
3306 * @port2: second port
3307 *
3308 * This utility function can be used to determine whether two uart_port
3309 * structures describe the same port.
3310 */
3311bool uart_match_port(const struct uart_port *port1,
3312 const struct uart_port *port2)
3313{
3314 if (port1->iotype != port2->iotype)
3315 return false;
3316
3317 switch (port1->iotype) {
3318 case UPIO_PORT:
3319 return port1->iobase == port2->iobase;
3320 case UPIO_HUB6:
3321 return port1->iobase == port2->iobase &&
3322 port1->hub6 == port2->hub6;
3323 case UPIO_MEM:
3324 case UPIO_MEM16:
3325 case UPIO_MEM32:
3326 case UPIO_MEM32BE:
3327 case UPIO_AU:
3328 case UPIO_TSI:
3329 return port1->mapbase == port2->mapbase;
3330 }
3331
3332 return false;
3333}
3334EXPORT_SYMBOL(uart_match_port);
3335
3336static struct serial_ctrl_device *
3337serial_core_get_ctrl_dev(struct serial_port_device *port_dev)
3338{
3339 struct device *dev = &port_dev->dev;
3340
3341 return to_serial_base_ctrl_device(dev->parent);
3342}
3343
3344/*
3345 * Find a registered serial core controller device if one exists. Returns
3346 * the first device matching the ctrl_id. Caller must hold port_mutex.
3347 */
3348static struct serial_ctrl_device *serial_core_ctrl_find(struct uart_driver *drv,
3349 struct device *phys_dev,
3350 int ctrl_id)
3351{
3352 struct uart_state *state;
3353 int i;
3354
3355 lockdep_assert_held(&port_mutex);
3356
3357 for (i = 0; i < drv->nr; i++) {
3358 state = drv->state + i;
3359 if (!state->uart_port || !state->uart_port->port_dev)
3360 continue;
3361
3362 if (state->uart_port->dev == phys_dev &&
3363 state->uart_port->ctrl_id == ctrl_id)
3364 return serial_core_get_ctrl_dev(state->uart_port->port_dev);
3365 }
3366
3367 return NULL;
3368}
3369
3370static struct serial_ctrl_device *serial_core_ctrl_device_add(struct uart_port *port)
3371{
3372 return serial_base_ctrl_add(port, port->dev);
3373}
3374
3375static int serial_core_port_device_add(struct serial_ctrl_device *ctrl_dev,
3376 struct uart_port *port)
3377{
3378 struct serial_port_device *port_dev;
3379
3380 port_dev = serial_base_port_add(port, ctrl_dev);
3381 if (IS_ERR(port_dev))
3382 return PTR_ERR(port_dev);
3383
3384 port->port_dev = port_dev;
3385
3386 return 0;
3387}
3388
3389/*
3390 * Initialize a serial core port device, and a controller device if needed.
3391 */
3392int serial_core_register_port(struct uart_driver *drv, struct uart_port *port)
3393{
3394 struct serial_ctrl_device *ctrl_dev, *new_ctrl_dev = NULL;
3395 int ret;
3396
3397 mutex_lock(&port_mutex);
3398
3399 /*
3400 * Prevent serial_port_runtime_resume() from trying to use the port
3401 * until serial_core_add_one_port() has completed
3402 */
3403 port->flags |= UPF_DEAD;
3404
3405 /* Inititalize a serial core controller device if needed */
3406 ctrl_dev = serial_core_ctrl_find(drv, port->dev, port->ctrl_id);
3407 if (!ctrl_dev) {
3408 new_ctrl_dev = serial_core_ctrl_device_add(port);
3409 if (IS_ERR(new_ctrl_dev)) {
3410 ret = PTR_ERR(new_ctrl_dev);
3411 goto err_unlock;
3412 }
3413 ctrl_dev = new_ctrl_dev;
3414 }
3415
3416 /*
3417 * Initialize a serial core port device. Tag the port dead to prevent
3418 * serial_port_runtime_resume() trying to do anything until port has
3419 * been registered. It gets cleared by serial_core_add_one_port().
3420 */
3421 ret = serial_core_port_device_add(ctrl_dev, port);
3422 if (ret)
3423 goto err_unregister_ctrl_dev;
3424
3425 ret = serial_core_add_one_port(drv, port);
3426 if (ret)
3427 goto err_unregister_port_dev;
3428
3429 port->flags &= ~UPF_DEAD;
3430
3431 mutex_unlock(&port_mutex);
3432
3433 return 0;
3434
3435err_unregister_port_dev:
3436 serial_base_port_device_remove(port->port_dev);
3437
3438err_unregister_ctrl_dev:
3439 serial_base_ctrl_device_remove(new_ctrl_dev);
3440
3441err_unlock:
3442 mutex_unlock(&port_mutex);
3443
3444 return ret;
3445}
3446
3447/*
3448 * Removes a serial core port device, and the related serial core controller
3449 * device if the last instance.
3450 */
3451void serial_core_unregister_port(struct uart_driver *drv, struct uart_port *port)
3452{
3453 struct device *phys_dev = port->dev;
3454 struct serial_port_device *port_dev = port->port_dev;
3455 struct serial_ctrl_device *ctrl_dev = serial_core_get_ctrl_dev(port_dev);
3456 int ctrl_id = port->ctrl_id;
3457
3458 mutex_lock(&port_mutex);
3459
3460 port->flags |= UPF_DEAD;
3461
3462 serial_core_remove_one_port(drv, port);
3463
3464 /* Note that struct uart_port *port is no longer valid at this point */
3465 serial_base_port_device_remove(port_dev);
3466
3467 /* Drop the serial core controller device if no ports are using it */
3468 if (!serial_core_ctrl_find(drv, phys_dev, ctrl_id))
3469 serial_base_ctrl_device_remove(ctrl_dev);
3470
3471 mutex_unlock(&port_mutex);
3472}
3473
3474/**
3475 * uart_handle_dcd_change - handle a change of carrier detect state
3476 * @uport: uart_port structure for the open port
3477 * @active: new carrier detect status
3478 *
3479 * Caller must hold uport->lock.
3480 */
3481void uart_handle_dcd_change(struct uart_port *uport, bool active)
3482{
3483 struct tty_port *port = &uport->state->port;
3484 struct tty_struct *tty = port->tty;
3485 struct tty_ldisc *ld;
3486
3487 lockdep_assert_held_once(&uport->lock);
3488
3489 if (tty) {
3490 ld = tty_ldisc_ref(tty);
3491 if (ld) {
3492 if (ld->ops->dcd_change)
3493 ld->ops->dcd_change(tty, active);
3494 tty_ldisc_deref(ld);
3495 }
3496 }
3497
3498 uport->icount.dcd++;
3499
3500 if (uart_dcd_enabled(uport)) {
3501 if (active)
3502 wake_up_interruptible(&port->open_wait);
3503 else if (tty)
3504 tty_hangup(tty);
3505 }
3506}
3507EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
3508
3509/**
3510 * uart_handle_cts_change - handle a change of clear-to-send state
3511 * @uport: uart_port structure for the open port
3512 * @active: new clear-to-send status
3513 *
3514 * Caller must hold uport->lock.
3515 */
3516void uart_handle_cts_change(struct uart_port *uport, bool active)
3517{
3518 lockdep_assert_held_once(&uport->lock);
3519
3520 uport->icount.cts++;
3521
3522 if (uart_softcts_mode(uport)) {
3523 if (uport->hw_stopped) {
3524 if (active) {
3525 uport->hw_stopped = false;
3526 uport->ops->start_tx(uport);
3527 uart_write_wakeup(uport);
3528 }
3529 } else {
3530 if (!active) {
3531 uport->hw_stopped = true;
3532 uport->ops->stop_tx(uport);
3533 }
3534 }
3535
3536 }
3537}
3538EXPORT_SYMBOL_GPL(uart_handle_cts_change);
3539
3540/**
3541 * uart_insert_char - push a char to the uart layer
3542 *
3543 * User is responsible to call tty_flip_buffer_push when they are done with
3544 * insertion.
3545 *
3546 * @port: corresponding port
3547 * @status: state of the serial port RX buffer (LSR for 8250)
3548 * @overrun: mask of overrun bits in @status
3549 * @ch: character to push
3550 * @flag: flag for the character (see TTY_NORMAL and friends)
3551 */
3552void uart_insert_char(struct uart_port *port, unsigned int status,
3553 unsigned int overrun, u8 ch, u8 flag)
3554{
3555 struct tty_port *tport = &port->state->port;
3556
3557 if ((status & port->ignore_status_mask & ~overrun) == 0)
3558 if (tty_insert_flip_char(tport, ch, flag) == 0)
3559 ++port->icount.buf_overrun;
3560
3561 /*
3562 * Overrun is special. Since it's reported immediately,
3563 * it doesn't affect the current character.
3564 */
3565 if (status & ~port->ignore_status_mask & overrun)
3566 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
3567 ++port->icount.buf_overrun;
3568}
3569EXPORT_SYMBOL_GPL(uart_insert_char);
3570
3571#ifdef CONFIG_MAGIC_SYSRQ_SERIAL
3572static const u8 sysrq_toggle_seq[] = CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE;
3573
3574static void uart_sysrq_on(struct work_struct *w)
3575{
3576 int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq);
3577
3578 sysrq_toggle_support(1);
3579 pr_info("SysRq is enabled by magic sequence '%*pE' on serial\n",
3580 sysrq_toggle_seq_len, sysrq_toggle_seq);
3581}
3582static DECLARE_WORK(sysrq_enable_work, uart_sysrq_on);
3583
3584/**
3585 * uart_try_toggle_sysrq - Enables SysRq from serial line
3586 * @port: uart_port structure where char(s) after BREAK met
3587 * @ch: new character in the sequence after received BREAK
3588 *
3589 * Enables magic SysRq when the required sequence is met on port
3590 * (see CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE).
3591 *
3592 * Returns: %false if @ch is out of enabling sequence and should be
3593 * handled some other way, %true if @ch was consumed.
3594 */
3595bool uart_try_toggle_sysrq(struct uart_port *port, u8 ch)
3596{
3597 int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq);
3598
3599 if (!sysrq_toggle_seq_len)
3600 return false;
3601
3602 BUILD_BUG_ON(ARRAY_SIZE(sysrq_toggle_seq) >= U8_MAX);
3603 if (sysrq_toggle_seq[port->sysrq_seq] != ch) {
3604 port->sysrq_seq = 0;
3605 return false;
3606 }
3607
3608 if (++port->sysrq_seq < sysrq_toggle_seq_len) {
3609 port->sysrq = jiffies + SYSRQ_TIMEOUT;
3610 return true;
3611 }
3612
3613 schedule_work(&sysrq_enable_work);
3614
3615 port->sysrq = 0;
3616 return true;
3617}
3618EXPORT_SYMBOL_GPL(uart_try_toggle_sysrq);
3619#endif
3620
3621/**
3622 * uart_get_rs485_mode() - retrieve rs485 properties for given uart
3623 * @port: uart device's target port
3624 *
3625 * This function implements the device tree binding described in
3626 * Documentation/devicetree/bindings/serial/rs485.txt.
3627 */
3628int uart_get_rs485_mode(struct uart_port *port)
3629{
3630 struct serial_rs485 *rs485conf = &port->rs485;
3631 struct device *dev = port->dev;
3632 enum gpiod_flags dflags;
3633 struct gpio_desc *desc;
3634 u32 rs485_delay[2];
3635 int ret;
3636
3637 if (!(port->rs485_supported.flags & SER_RS485_ENABLED))
3638 return 0;
3639
3640 ret = device_property_read_u32_array(dev, "rs485-rts-delay",
3641 rs485_delay, 2);
3642 if (!ret) {
3643 rs485conf->delay_rts_before_send = rs485_delay[0];
3644 rs485conf->delay_rts_after_send = rs485_delay[1];
3645 } else {
3646 rs485conf->delay_rts_before_send = 0;
3647 rs485conf->delay_rts_after_send = 0;
3648 }
3649
3650 uart_sanitize_serial_rs485_delays(port, rs485conf);
3651
3652 /*
3653 * Clear full-duplex and enabled flags, set RTS polarity to active high
3654 * to get to a defined state with the following properties:
3655 */
3656 rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED |
3657 SER_RS485_TERMINATE_BUS |
3658 SER_RS485_RTS_AFTER_SEND);
3659 rs485conf->flags |= SER_RS485_RTS_ON_SEND;
3660
3661 if (device_property_read_bool(dev, "rs485-rx-during-tx"))
3662 rs485conf->flags |= SER_RS485_RX_DURING_TX;
3663
3664 if (device_property_read_bool(dev, "linux,rs485-enabled-at-boot-time"))
3665 rs485conf->flags |= SER_RS485_ENABLED;
3666
3667 if (device_property_read_bool(dev, "rs485-rts-active-low")) {
3668 rs485conf->flags &= ~SER_RS485_RTS_ON_SEND;
3669 rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
3670 }
3671
3672 /*
3673 * Disabling termination by default is the safe choice: Else if many
3674 * bus participants enable it, no communication is possible at all.
3675 * Works fine for short cables and users may enable for longer cables.
3676 */
3677 desc = devm_gpiod_get_optional(dev, "rs485-term", GPIOD_OUT_LOW);
3678 if (IS_ERR(desc))
3679 return dev_err_probe(dev, PTR_ERR(desc), "Cannot get rs485-term-gpios\n");
3680 port->rs485_term_gpio = desc;
3681 if (port->rs485_term_gpio)
3682 port->rs485_supported.flags |= SER_RS485_TERMINATE_BUS;
3683
3684 dflags = (rs485conf->flags & SER_RS485_RX_DURING_TX) ?
3685 GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
3686 desc = devm_gpiod_get_optional(dev, "rs485-rx-during-tx", dflags);
3687 if (IS_ERR(desc))
3688 return dev_err_probe(dev, PTR_ERR(desc), "Cannot get rs485-rx-during-tx-gpios\n");
3689 port->rs485_rx_during_tx_gpio = desc;
3690 if (port->rs485_rx_during_tx_gpio)
3691 port->rs485_supported.flags |= SER_RS485_RX_DURING_TX;
3692
3693 return 0;
3694}
3695EXPORT_SYMBOL_GPL(uart_get_rs485_mode);
3696
3697/* Compile-time assertions for serial_rs485 layout */
3698static_assert(offsetof(struct serial_rs485, padding) ==
3699 (offsetof(struct serial_rs485, delay_rts_after_send) + sizeof(__u32)));
3700static_assert(offsetof(struct serial_rs485, padding1) ==
3701 offsetof(struct serial_rs485, padding[1]));
3702static_assert((offsetof(struct serial_rs485, padding[4]) + sizeof(__u32)) ==
3703 sizeof(struct serial_rs485));
3704
3705MODULE_DESCRIPTION("Serial driver core");
3706MODULE_LICENSE("GPL");