Loading...
1/*
2 * Driver core for serial ports
3 *
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
5 *
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 */
23#include <linux/module.h>
24#include <linux/tty.h>
25#include <linux/slab.h>
26#include <linux/init.h>
27#include <linux/console.h>
28#include <linux/proc_fs.h>
29#include <linux/seq_file.h>
30#include <linux/device.h>
31#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
32#include <linux/serial_core.h>
33#include <linux/delay.h>
34#include <linux/mutex.h>
35
36#include <asm/irq.h>
37#include <asm/uaccess.h>
38
39/*
40 * This is used to lock changes in serial line configuration.
41 */
42static DEFINE_MUTEX(port_mutex);
43
44/*
45 * lockdep: port->lock is initialized in two places, but we
46 * want only one lock-class:
47 */
48static struct lock_class_key port_lock_key;
49
50#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
51
52#ifdef CONFIG_SERIAL_CORE_CONSOLE
53#define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
54#else
55#define uart_console(port) (0)
56#endif
57
58static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
59 struct ktermios *old_termios);
60static void __uart_wait_until_sent(struct uart_port *port, int timeout);
61static void uart_change_pm(struct uart_state *state, int pm_state);
62
63/*
64 * This routine is used by the interrupt handler to schedule processing in
65 * the software interrupt portion of the driver.
66 */
67void uart_write_wakeup(struct uart_port *port)
68{
69 struct uart_state *state = port->state;
70 /*
71 * This means you called this function _after_ the port was
72 * closed. No cookie for you.
73 */
74 BUG_ON(!state);
75 tasklet_schedule(&state->tlet);
76}
77
78static void uart_stop(struct tty_struct *tty)
79{
80 struct uart_state *state = tty->driver_data;
81 struct uart_port *port = state->uart_port;
82 unsigned long flags;
83
84 spin_lock_irqsave(&port->lock, flags);
85 port->ops->stop_tx(port);
86 spin_unlock_irqrestore(&port->lock, flags);
87}
88
89static void __uart_start(struct tty_struct *tty)
90{
91 struct uart_state *state = tty->driver_data;
92 struct uart_port *port = state->uart_port;
93
94 if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
95 !tty->stopped && !tty->hw_stopped)
96 port->ops->start_tx(port);
97}
98
99static void uart_start(struct tty_struct *tty)
100{
101 struct uart_state *state = tty->driver_data;
102 struct uart_port *port = state->uart_port;
103 unsigned long flags;
104
105 spin_lock_irqsave(&port->lock, flags);
106 __uart_start(tty);
107 spin_unlock_irqrestore(&port->lock, flags);
108}
109
110static void uart_tasklet_action(unsigned long data)
111{
112 struct uart_state *state = (struct uart_state *)data;
113 tty_wakeup(state->port.tty);
114}
115
116static inline void
117uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
118{
119 unsigned long flags;
120 unsigned int old;
121
122 spin_lock_irqsave(&port->lock, flags);
123 old = port->mctrl;
124 port->mctrl = (old & ~clear) | set;
125 if (old != port->mctrl)
126 port->ops->set_mctrl(port, port->mctrl);
127 spin_unlock_irqrestore(&port->lock, flags);
128}
129
130#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
131#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
132
133/*
134 * Startup the port. This will be called once per open. All calls
135 * will be serialised by the per-port mutex.
136 */
137static int uart_startup(struct tty_struct *tty, struct uart_state *state, int init_hw)
138{
139 struct uart_port *uport = state->uart_port;
140 struct tty_port *port = &state->port;
141 unsigned long page;
142 int retval = 0;
143
144 if (port->flags & ASYNC_INITIALIZED)
145 return 0;
146
147 /*
148 * Set the TTY IO error marker - we will only clear this
149 * once we have successfully opened the port. Also set
150 * up the tty->alt_speed kludge
151 */
152 set_bit(TTY_IO_ERROR, &tty->flags);
153
154 if (uport->type == PORT_UNKNOWN)
155 return 0;
156
157 /*
158 * Initialise and allocate the transmit and temporary
159 * buffer.
160 */
161 if (!state->xmit.buf) {
162 /* This is protected by the per port mutex */
163 page = get_zeroed_page(GFP_KERNEL);
164 if (!page)
165 return -ENOMEM;
166
167 state->xmit.buf = (unsigned char *) page;
168 uart_circ_clear(&state->xmit);
169 }
170
171 retval = uport->ops->startup(uport);
172 if (retval == 0) {
173 if (uart_console(uport) && uport->cons->cflag) {
174 tty->termios->c_cflag = uport->cons->cflag;
175 uport->cons->cflag = 0;
176 }
177 /*
178 * Initialise the hardware port settings.
179 */
180 uart_change_speed(tty, state, NULL);
181
182 if (init_hw) {
183 /*
184 * Setup the RTS and DTR signals once the
185 * port is open and ready to respond.
186 */
187 if (tty->termios->c_cflag & CBAUD)
188 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
189 }
190
191 if (port->flags & ASYNC_CTS_FLOW) {
192 spin_lock_irq(&uport->lock);
193 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
194 tty->hw_stopped = 1;
195 spin_unlock_irq(&uport->lock);
196 }
197
198 set_bit(ASYNCB_INITIALIZED, &port->flags);
199
200 clear_bit(TTY_IO_ERROR, &tty->flags);
201 }
202
203 /*
204 * This is to allow setserial on this port. People may want to set
205 * port/irq/type and then reconfigure the port properly if it failed
206 * now.
207 */
208 if (retval && capable(CAP_SYS_ADMIN))
209 retval = 0;
210
211 return retval;
212}
213
214/*
215 * This routine will shutdown a serial port; interrupts are disabled, and
216 * DTR is dropped if the hangup on close termio flag is on. Calls to
217 * uart_shutdown are serialised by the per-port semaphore.
218 */
219static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
220{
221 struct uart_port *uport = state->uart_port;
222 struct tty_port *port = &state->port;
223
224 /*
225 * Set the TTY IO error marker
226 */
227 if (tty)
228 set_bit(TTY_IO_ERROR, &tty->flags);
229
230 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
231 /*
232 * Turn off DTR and RTS early.
233 */
234 if (!tty || (tty->termios->c_cflag & HUPCL))
235 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
236
237 /*
238 * clear delta_msr_wait queue to avoid mem leaks: we may free
239 * the irq here so the queue might never be woken up. Note
240 * that we won't end up waiting on delta_msr_wait again since
241 * any outstanding file descriptors should be pointing at
242 * hung_up_tty_fops now.
243 */
244 wake_up_interruptible(&port->delta_msr_wait);
245
246 /*
247 * Free the IRQ and disable the port.
248 */
249 uport->ops->shutdown(uport);
250
251 /*
252 * Ensure that the IRQ handler isn't running on another CPU.
253 */
254 synchronize_irq(uport->irq);
255 }
256
257 /*
258 * kill off our tasklet
259 */
260 tasklet_kill(&state->tlet);
261
262 /*
263 * Free the transmit buffer page.
264 */
265 if (state->xmit.buf) {
266 free_page((unsigned long)state->xmit.buf);
267 state->xmit.buf = NULL;
268 }
269}
270
271/**
272 * uart_update_timeout - update per-port FIFO timeout.
273 * @port: uart_port structure describing the port
274 * @cflag: termios cflag value
275 * @baud: speed of the port
276 *
277 * Set the port FIFO timeout value. The @cflag value should
278 * reflect the actual hardware settings.
279 */
280void
281uart_update_timeout(struct uart_port *port, unsigned int cflag,
282 unsigned int baud)
283{
284 unsigned int bits;
285
286 /* byte size and parity */
287 switch (cflag & CSIZE) {
288 case CS5:
289 bits = 7;
290 break;
291 case CS6:
292 bits = 8;
293 break;
294 case CS7:
295 bits = 9;
296 break;
297 default:
298 bits = 10;
299 break; /* CS8 */
300 }
301
302 if (cflag & CSTOPB)
303 bits++;
304 if (cflag & PARENB)
305 bits++;
306
307 /*
308 * The total number of bits to be transmitted in the fifo.
309 */
310 bits = bits * port->fifosize;
311
312 /*
313 * Figure the timeout to send the above number of bits.
314 * Add .02 seconds of slop
315 */
316 port->timeout = (HZ * bits) / baud + HZ/50;
317}
318
319EXPORT_SYMBOL(uart_update_timeout);
320
321/**
322 * uart_get_baud_rate - return baud rate for a particular port
323 * @port: uart_port structure describing the port in question.
324 * @termios: desired termios settings.
325 * @old: old termios (or NULL)
326 * @min: minimum acceptable baud rate
327 * @max: maximum acceptable baud rate
328 *
329 * Decode the termios structure into a numeric baud rate,
330 * taking account of the magic 38400 baud rate (with spd_*
331 * flags), and mapping the %B0 rate to 9600 baud.
332 *
333 * If the new baud rate is invalid, try the old termios setting.
334 * If it's still invalid, we try 9600 baud.
335 *
336 * Update the @termios structure to reflect the baud rate
337 * we're actually going to be using. Don't do this for the case
338 * where B0 is requested ("hang up").
339 */
340unsigned int
341uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
342 struct ktermios *old, unsigned int min, unsigned int max)
343{
344 unsigned int try, baud, altbaud = 38400;
345 int hung_up = 0;
346 upf_t flags = port->flags & UPF_SPD_MASK;
347
348 if (flags == UPF_SPD_HI)
349 altbaud = 57600;
350 else if (flags == UPF_SPD_VHI)
351 altbaud = 115200;
352 else if (flags == UPF_SPD_SHI)
353 altbaud = 230400;
354 else if (flags == UPF_SPD_WARP)
355 altbaud = 460800;
356
357 for (try = 0; try < 2; try++) {
358 baud = tty_termios_baud_rate(termios);
359
360 /*
361 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
362 * Die! Die! Die!
363 */
364 if (baud == 38400)
365 baud = altbaud;
366
367 /*
368 * Special case: B0 rate.
369 */
370 if (baud == 0) {
371 hung_up = 1;
372 baud = 9600;
373 }
374
375 if (baud >= min && baud <= max)
376 return baud;
377
378 /*
379 * Oops, the quotient was zero. Try again with
380 * the old baud rate if possible.
381 */
382 termios->c_cflag &= ~CBAUD;
383 if (old) {
384 baud = tty_termios_baud_rate(old);
385 if (!hung_up)
386 tty_termios_encode_baud_rate(termios,
387 baud, baud);
388 old = NULL;
389 continue;
390 }
391
392 /*
393 * As a last resort, if the range cannot be met then clip to
394 * the nearest chip supported rate.
395 */
396 if (!hung_up) {
397 if (baud <= min)
398 tty_termios_encode_baud_rate(termios,
399 min + 1, min + 1);
400 else
401 tty_termios_encode_baud_rate(termios,
402 max - 1, max - 1);
403 }
404 }
405 /* Should never happen */
406 WARN_ON(1);
407 return 0;
408}
409
410EXPORT_SYMBOL(uart_get_baud_rate);
411
412/**
413 * uart_get_divisor - return uart clock divisor
414 * @port: uart_port structure describing the port.
415 * @baud: desired baud rate
416 *
417 * Calculate the uart clock divisor for the port.
418 */
419unsigned int
420uart_get_divisor(struct uart_port *port, unsigned int baud)
421{
422 unsigned int quot;
423
424 /*
425 * Old custom speed handling.
426 */
427 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
428 quot = port->custom_divisor;
429 else
430 quot = (port->uartclk + (8 * baud)) / (16 * baud);
431
432 return quot;
433}
434
435EXPORT_SYMBOL(uart_get_divisor);
436
437/* FIXME: Consistent locking policy */
438static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
439 struct ktermios *old_termios)
440{
441 struct tty_port *port = &state->port;
442 struct uart_port *uport = state->uart_port;
443 struct ktermios *termios;
444
445 /*
446 * If we have no tty, termios, or the port does not exist,
447 * then we can't set the parameters for this port.
448 */
449 if (!tty || !tty->termios || uport->type == PORT_UNKNOWN)
450 return;
451
452 termios = tty->termios;
453
454 /*
455 * Set flags based on termios cflag
456 */
457 if (termios->c_cflag & CRTSCTS)
458 set_bit(ASYNCB_CTS_FLOW, &port->flags);
459 else
460 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
461
462 if (termios->c_cflag & CLOCAL)
463 clear_bit(ASYNCB_CHECK_CD, &port->flags);
464 else
465 set_bit(ASYNCB_CHECK_CD, &port->flags);
466
467 uport->ops->set_termios(uport, termios, old_termios);
468}
469
470static inline int __uart_put_char(struct uart_port *port,
471 struct circ_buf *circ, unsigned char c)
472{
473 unsigned long flags;
474 int ret = 0;
475
476 if (!circ->buf)
477 return 0;
478
479 spin_lock_irqsave(&port->lock, flags);
480 if (uart_circ_chars_free(circ) != 0) {
481 circ->buf[circ->head] = c;
482 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
483 ret = 1;
484 }
485 spin_unlock_irqrestore(&port->lock, flags);
486 return ret;
487}
488
489static int uart_put_char(struct tty_struct *tty, unsigned char ch)
490{
491 struct uart_state *state = tty->driver_data;
492
493 return __uart_put_char(state->uart_port, &state->xmit, ch);
494}
495
496static void uart_flush_chars(struct tty_struct *tty)
497{
498 uart_start(tty);
499}
500
501static int uart_write(struct tty_struct *tty,
502 const unsigned char *buf, int count)
503{
504 struct uart_state *state = tty->driver_data;
505 struct uart_port *port;
506 struct circ_buf *circ;
507 unsigned long flags;
508 int c, ret = 0;
509
510 /*
511 * This means you called this function _after_ the port was
512 * closed. No cookie for you.
513 */
514 if (!state) {
515 WARN_ON(1);
516 return -EL3HLT;
517 }
518
519 port = state->uart_port;
520 circ = &state->xmit;
521
522 if (!circ->buf)
523 return 0;
524
525 spin_lock_irqsave(&port->lock, flags);
526 while (1) {
527 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
528 if (count < c)
529 c = count;
530 if (c <= 0)
531 break;
532 memcpy(circ->buf + circ->head, buf, c);
533 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
534 buf += c;
535 count -= c;
536 ret += c;
537 }
538 spin_unlock_irqrestore(&port->lock, flags);
539
540 uart_start(tty);
541 return ret;
542}
543
544static int uart_write_room(struct tty_struct *tty)
545{
546 struct uart_state *state = tty->driver_data;
547 unsigned long flags;
548 int ret;
549
550 spin_lock_irqsave(&state->uart_port->lock, flags);
551 ret = uart_circ_chars_free(&state->xmit);
552 spin_unlock_irqrestore(&state->uart_port->lock, flags);
553 return ret;
554}
555
556static int uart_chars_in_buffer(struct tty_struct *tty)
557{
558 struct uart_state *state = tty->driver_data;
559 unsigned long flags;
560 int ret;
561
562 spin_lock_irqsave(&state->uart_port->lock, flags);
563 ret = uart_circ_chars_pending(&state->xmit);
564 spin_unlock_irqrestore(&state->uart_port->lock, flags);
565 return ret;
566}
567
568static void uart_flush_buffer(struct tty_struct *tty)
569{
570 struct uart_state *state = tty->driver_data;
571 struct uart_port *port;
572 unsigned long flags;
573
574 /*
575 * This means you called this function _after_ the port was
576 * closed. No cookie for you.
577 */
578 if (!state) {
579 WARN_ON(1);
580 return;
581 }
582
583 port = state->uart_port;
584 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
585
586 spin_lock_irqsave(&port->lock, flags);
587 uart_circ_clear(&state->xmit);
588 if (port->ops->flush_buffer)
589 port->ops->flush_buffer(port);
590 spin_unlock_irqrestore(&port->lock, flags);
591 tty_wakeup(tty);
592}
593
594/*
595 * This function is used to send a high-priority XON/XOFF character to
596 * the device
597 */
598static void uart_send_xchar(struct tty_struct *tty, char ch)
599{
600 struct uart_state *state = tty->driver_data;
601 struct uart_port *port = state->uart_port;
602 unsigned long flags;
603
604 if (port->ops->send_xchar)
605 port->ops->send_xchar(port, ch);
606 else {
607 port->x_char = ch;
608 if (ch) {
609 spin_lock_irqsave(&port->lock, flags);
610 port->ops->start_tx(port);
611 spin_unlock_irqrestore(&port->lock, flags);
612 }
613 }
614}
615
616static void uart_throttle(struct tty_struct *tty)
617{
618 struct uart_state *state = tty->driver_data;
619
620 if (I_IXOFF(tty))
621 uart_send_xchar(tty, STOP_CHAR(tty));
622
623 if (tty->termios->c_cflag & CRTSCTS)
624 uart_clear_mctrl(state->uart_port, TIOCM_RTS);
625}
626
627static void uart_unthrottle(struct tty_struct *tty)
628{
629 struct uart_state *state = tty->driver_data;
630 struct uart_port *port = state->uart_port;
631
632 if (I_IXOFF(tty)) {
633 if (port->x_char)
634 port->x_char = 0;
635 else
636 uart_send_xchar(tty, START_CHAR(tty));
637 }
638
639 if (tty->termios->c_cflag & CRTSCTS)
640 uart_set_mctrl(port, TIOCM_RTS);
641}
642
643static int uart_get_info(struct uart_state *state,
644 struct serial_struct __user *retinfo)
645{
646 struct uart_port *uport = state->uart_port;
647 struct tty_port *port = &state->port;
648 struct serial_struct tmp;
649
650 memset(&tmp, 0, sizeof(tmp));
651
652 /* Ensure the state we copy is consistent and no hardware changes
653 occur as we go */
654 mutex_lock(&port->mutex);
655
656 tmp.type = uport->type;
657 tmp.line = uport->line;
658 tmp.port = uport->iobase;
659 if (HIGH_BITS_OFFSET)
660 tmp.port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
661 tmp.irq = uport->irq;
662 tmp.flags = uport->flags;
663 tmp.xmit_fifo_size = uport->fifosize;
664 tmp.baud_base = uport->uartclk / 16;
665 tmp.close_delay = port->close_delay / 10;
666 tmp.closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
667 ASYNC_CLOSING_WAIT_NONE :
668 port->closing_wait / 10;
669 tmp.custom_divisor = uport->custom_divisor;
670 tmp.hub6 = uport->hub6;
671 tmp.io_type = uport->iotype;
672 tmp.iomem_reg_shift = uport->regshift;
673 tmp.iomem_base = (void *)(unsigned long)uport->mapbase;
674
675 mutex_unlock(&port->mutex);
676
677 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
678 return -EFAULT;
679 return 0;
680}
681
682static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
683 struct serial_struct __user *newinfo)
684{
685 struct serial_struct new_serial;
686 struct uart_port *uport = state->uart_port;
687 struct tty_port *port = &state->port;
688 unsigned long new_port;
689 unsigned int change_irq, change_port, closing_wait;
690 unsigned int old_custom_divisor, close_delay;
691 upf_t old_flags, new_flags;
692 int retval = 0;
693
694 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
695 return -EFAULT;
696
697 new_port = new_serial.port;
698 if (HIGH_BITS_OFFSET)
699 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
700
701 new_serial.irq = irq_canonicalize(new_serial.irq);
702 close_delay = new_serial.close_delay * 10;
703 closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
704 ASYNC_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
705
706 /*
707 * This semaphore protects port->count. It is also
708 * very useful to prevent opens. Also, take the
709 * port configuration semaphore to make sure that a
710 * module insertion/removal doesn't change anything
711 * under us.
712 */
713 mutex_lock(&port->mutex);
714
715 change_irq = !(uport->flags & UPF_FIXED_PORT)
716 && new_serial.irq != uport->irq;
717
718 /*
719 * Since changing the 'type' of the port changes its resource
720 * allocations, we should treat type changes the same as
721 * IO port changes.
722 */
723 change_port = !(uport->flags & UPF_FIXED_PORT)
724 && (new_port != uport->iobase ||
725 (unsigned long)new_serial.iomem_base != uport->mapbase ||
726 new_serial.hub6 != uport->hub6 ||
727 new_serial.io_type != uport->iotype ||
728 new_serial.iomem_reg_shift != uport->regshift ||
729 new_serial.type != uport->type);
730
731 old_flags = uport->flags;
732 new_flags = new_serial.flags;
733 old_custom_divisor = uport->custom_divisor;
734
735 if (!capable(CAP_SYS_ADMIN)) {
736 retval = -EPERM;
737 if (change_irq || change_port ||
738 (new_serial.baud_base != uport->uartclk / 16) ||
739 (close_delay != port->close_delay) ||
740 (closing_wait != port->closing_wait) ||
741 (new_serial.xmit_fifo_size &&
742 new_serial.xmit_fifo_size != uport->fifosize) ||
743 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
744 goto exit;
745 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
746 (new_flags & UPF_USR_MASK));
747 uport->custom_divisor = new_serial.custom_divisor;
748 goto check_and_exit;
749 }
750
751 /*
752 * Ask the low level driver to verify the settings.
753 */
754 if (uport->ops->verify_port)
755 retval = uport->ops->verify_port(uport, &new_serial);
756
757 if ((new_serial.irq >= nr_irqs) || (new_serial.irq < 0) ||
758 (new_serial.baud_base < 9600))
759 retval = -EINVAL;
760
761 if (retval)
762 goto exit;
763
764 if (change_port || change_irq) {
765 retval = -EBUSY;
766
767 /*
768 * Make sure that we are the sole user of this port.
769 */
770 if (tty_port_users(port) > 1)
771 goto exit;
772
773 /*
774 * We need to shutdown the serial port at the old
775 * port/type/irq combination.
776 */
777 uart_shutdown(tty, state);
778 }
779
780 if (change_port) {
781 unsigned long old_iobase, old_mapbase;
782 unsigned int old_type, old_iotype, old_hub6, old_shift;
783
784 old_iobase = uport->iobase;
785 old_mapbase = uport->mapbase;
786 old_type = uport->type;
787 old_hub6 = uport->hub6;
788 old_iotype = uport->iotype;
789 old_shift = uport->regshift;
790
791 /*
792 * Free and release old regions
793 */
794 if (old_type != PORT_UNKNOWN)
795 uport->ops->release_port(uport);
796
797 uport->iobase = new_port;
798 uport->type = new_serial.type;
799 uport->hub6 = new_serial.hub6;
800 uport->iotype = new_serial.io_type;
801 uport->regshift = new_serial.iomem_reg_shift;
802 uport->mapbase = (unsigned long)new_serial.iomem_base;
803
804 /*
805 * Claim and map the new regions
806 */
807 if (uport->type != PORT_UNKNOWN) {
808 retval = uport->ops->request_port(uport);
809 } else {
810 /* Always success - Jean II */
811 retval = 0;
812 }
813
814 /*
815 * If we fail to request resources for the
816 * new port, try to restore the old settings.
817 */
818 if (retval && old_type != PORT_UNKNOWN) {
819 uport->iobase = old_iobase;
820 uport->type = old_type;
821 uport->hub6 = old_hub6;
822 uport->iotype = old_iotype;
823 uport->regshift = old_shift;
824 uport->mapbase = old_mapbase;
825 retval = uport->ops->request_port(uport);
826 /*
827 * If we failed to restore the old settings,
828 * we fail like this.
829 */
830 if (retval)
831 uport->type = PORT_UNKNOWN;
832
833 /*
834 * We failed anyway.
835 */
836 retval = -EBUSY;
837 /* Added to return the correct error -Ram Gupta */
838 goto exit;
839 }
840 }
841
842 if (change_irq)
843 uport->irq = new_serial.irq;
844 if (!(uport->flags & UPF_FIXED_PORT))
845 uport->uartclk = new_serial.baud_base * 16;
846 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
847 (new_flags & UPF_CHANGE_MASK);
848 uport->custom_divisor = new_serial.custom_divisor;
849 port->close_delay = close_delay;
850 port->closing_wait = closing_wait;
851 if (new_serial.xmit_fifo_size)
852 uport->fifosize = new_serial.xmit_fifo_size;
853 if (port->tty)
854 port->tty->low_latency =
855 (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
856
857 check_and_exit:
858 retval = 0;
859 if (uport->type == PORT_UNKNOWN)
860 goto exit;
861 if (port->flags & ASYNC_INITIALIZED) {
862 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
863 old_custom_divisor != uport->custom_divisor) {
864 /*
865 * If they're setting up a custom divisor or speed,
866 * instead of clearing it, then bitch about it. No
867 * need to rate-limit; it's CAP_SYS_ADMIN only.
868 */
869 if (uport->flags & UPF_SPD_MASK) {
870 char buf[64];
871 printk(KERN_NOTICE
872 "%s sets custom speed on %s. This "
873 "is deprecated.\n", current->comm,
874 tty_name(port->tty, buf));
875 }
876 uart_change_speed(tty, state, NULL);
877 }
878 } else
879 retval = uart_startup(tty, state, 1);
880 exit:
881 mutex_unlock(&port->mutex);
882 return retval;
883}
884
885/**
886 * uart_get_lsr_info - get line status register info
887 * @tty: tty associated with the UART
888 * @state: UART being queried
889 * @value: returned modem value
890 *
891 * Note: uart_ioctl protects us against hangups.
892 */
893static int uart_get_lsr_info(struct tty_struct *tty,
894 struct uart_state *state, unsigned int __user *value)
895{
896 struct uart_port *uport = state->uart_port;
897 unsigned int result;
898
899 result = uport->ops->tx_empty(uport);
900
901 /*
902 * If we're about to load something into the transmit
903 * register, we'll pretend the transmitter isn't empty to
904 * avoid a race condition (depending on when the transmit
905 * interrupt happens).
906 */
907 if (uport->x_char ||
908 ((uart_circ_chars_pending(&state->xmit) > 0) &&
909 !tty->stopped && !tty->hw_stopped))
910 result &= ~TIOCSER_TEMT;
911
912 return put_user(result, value);
913}
914
915static int uart_tiocmget(struct tty_struct *tty)
916{
917 struct uart_state *state = tty->driver_data;
918 struct tty_port *port = &state->port;
919 struct uart_port *uport = state->uart_port;
920 int result = -EIO;
921
922 mutex_lock(&port->mutex);
923 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
924 result = uport->mctrl;
925 spin_lock_irq(&uport->lock);
926 result |= uport->ops->get_mctrl(uport);
927 spin_unlock_irq(&uport->lock);
928 }
929 mutex_unlock(&port->mutex);
930
931 return result;
932}
933
934static int
935uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
936{
937 struct uart_state *state = tty->driver_data;
938 struct uart_port *uport = state->uart_port;
939 struct tty_port *port = &state->port;
940 int ret = -EIO;
941
942 mutex_lock(&port->mutex);
943 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
944 uart_update_mctrl(uport, set, clear);
945 ret = 0;
946 }
947 mutex_unlock(&port->mutex);
948 return ret;
949}
950
951static int uart_break_ctl(struct tty_struct *tty, int break_state)
952{
953 struct uart_state *state = tty->driver_data;
954 struct tty_port *port = &state->port;
955 struct uart_port *uport = state->uart_port;
956
957 mutex_lock(&port->mutex);
958
959 if (uport->type != PORT_UNKNOWN)
960 uport->ops->break_ctl(uport, break_state);
961
962 mutex_unlock(&port->mutex);
963 return 0;
964}
965
966static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
967{
968 struct uart_port *uport = state->uart_port;
969 struct tty_port *port = &state->port;
970 int flags, ret;
971
972 if (!capable(CAP_SYS_ADMIN))
973 return -EPERM;
974
975 /*
976 * Take the per-port semaphore. This prevents count from
977 * changing, and hence any extra opens of the port while
978 * we're auto-configuring.
979 */
980 if (mutex_lock_interruptible(&port->mutex))
981 return -ERESTARTSYS;
982
983 ret = -EBUSY;
984 if (tty_port_users(port) == 1) {
985 uart_shutdown(tty, state);
986
987 /*
988 * If we already have a port type configured,
989 * we must release its resources.
990 */
991 if (uport->type != PORT_UNKNOWN)
992 uport->ops->release_port(uport);
993
994 flags = UART_CONFIG_TYPE;
995 if (uport->flags & UPF_AUTO_IRQ)
996 flags |= UART_CONFIG_IRQ;
997
998 /*
999 * This will claim the ports resources if
1000 * a port is found.
1001 */
1002 uport->ops->config_port(uport, flags);
1003
1004 ret = uart_startup(tty, state, 1);
1005 }
1006 mutex_unlock(&port->mutex);
1007 return ret;
1008}
1009
1010/*
1011 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1012 * - mask passed in arg for lines of interest
1013 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1014 * Caller should use TIOCGICOUNT to see which one it was
1015 *
1016 * FIXME: This wants extracting into a common all driver implementation
1017 * of TIOCMWAIT using tty_port.
1018 */
1019static int
1020uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1021{
1022 struct uart_port *uport = state->uart_port;
1023 struct tty_port *port = &state->port;
1024 DECLARE_WAITQUEUE(wait, current);
1025 struct uart_icount cprev, cnow;
1026 int ret;
1027
1028 /*
1029 * note the counters on entry
1030 */
1031 spin_lock_irq(&uport->lock);
1032 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1033
1034 /*
1035 * Force modem status interrupts on
1036 */
1037 uport->ops->enable_ms(uport);
1038 spin_unlock_irq(&uport->lock);
1039
1040 add_wait_queue(&port->delta_msr_wait, &wait);
1041 for (;;) {
1042 spin_lock_irq(&uport->lock);
1043 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1044 spin_unlock_irq(&uport->lock);
1045
1046 set_current_state(TASK_INTERRUPTIBLE);
1047
1048 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1049 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1050 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1051 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1052 ret = 0;
1053 break;
1054 }
1055
1056 schedule();
1057
1058 /* see if a signal did it */
1059 if (signal_pending(current)) {
1060 ret = -ERESTARTSYS;
1061 break;
1062 }
1063
1064 cprev = cnow;
1065 }
1066
1067 current->state = TASK_RUNNING;
1068 remove_wait_queue(&port->delta_msr_wait, &wait);
1069
1070 return ret;
1071}
1072
1073/*
1074 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1075 * Return: write counters to the user passed counter struct
1076 * NB: both 1->0 and 0->1 transitions are counted except for
1077 * RI where only 0->1 is counted.
1078 */
1079static int uart_get_icount(struct tty_struct *tty,
1080 struct serial_icounter_struct *icount)
1081{
1082 struct uart_state *state = tty->driver_data;
1083 struct uart_icount cnow;
1084 struct uart_port *uport = state->uart_port;
1085
1086 spin_lock_irq(&uport->lock);
1087 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1088 spin_unlock_irq(&uport->lock);
1089
1090 icount->cts = cnow.cts;
1091 icount->dsr = cnow.dsr;
1092 icount->rng = cnow.rng;
1093 icount->dcd = cnow.dcd;
1094 icount->rx = cnow.rx;
1095 icount->tx = cnow.tx;
1096 icount->frame = cnow.frame;
1097 icount->overrun = cnow.overrun;
1098 icount->parity = cnow.parity;
1099 icount->brk = cnow.brk;
1100 icount->buf_overrun = cnow.buf_overrun;
1101
1102 return 0;
1103}
1104
1105/*
1106 * Called via sys_ioctl. We can use spin_lock_irq() here.
1107 */
1108static int
1109uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1110 unsigned long arg)
1111{
1112 struct uart_state *state = tty->driver_data;
1113 struct tty_port *port = &state->port;
1114 void __user *uarg = (void __user *)arg;
1115 int ret = -ENOIOCTLCMD;
1116
1117
1118 /*
1119 * These ioctls don't rely on the hardware to be present.
1120 */
1121 switch (cmd) {
1122 case TIOCGSERIAL:
1123 ret = uart_get_info(state, uarg);
1124 break;
1125
1126 case TIOCSSERIAL:
1127 ret = uart_set_info(tty, state, uarg);
1128 break;
1129
1130 case TIOCSERCONFIG:
1131 ret = uart_do_autoconfig(tty, state);
1132 break;
1133
1134 case TIOCSERGWILD: /* obsolete */
1135 case TIOCSERSWILD: /* obsolete */
1136 ret = 0;
1137 break;
1138 }
1139
1140 if (ret != -ENOIOCTLCMD)
1141 goto out;
1142
1143 if (tty->flags & (1 << TTY_IO_ERROR)) {
1144 ret = -EIO;
1145 goto out;
1146 }
1147
1148 /*
1149 * The following should only be used when hardware is present.
1150 */
1151 switch (cmd) {
1152 case TIOCMIWAIT:
1153 ret = uart_wait_modem_status(state, arg);
1154 break;
1155 }
1156
1157 if (ret != -ENOIOCTLCMD)
1158 goto out;
1159
1160 mutex_lock(&port->mutex);
1161
1162 if (tty->flags & (1 << TTY_IO_ERROR)) {
1163 ret = -EIO;
1164 goto out_up;
1165 }
1166
1167 /*
1168 * All these rely on hardware being present and need to be
1169 * protected against the tty being hung up.
1170 */
1171 switch (cmd) {
1172 case TIOCSERGETLSR: /* Get line status register */
1173 ret = uart_get_lsr_info(tty, state, uarg);
1174 break;
1175
1176 default: {
1177 struct uart_port *uport = state->uart_port;
1178 if (uport->ops->ioctl)
1179 ret = uport->ops->ioctl(uport, cmd, arg);
1180 break;
1181 }
1182 }
1183out_up:
1184 mutex_unlock(&port->mutex);
1185out:
1186 return ret;
1187}
1188
1189static void uart_set_ldisc(struct tty_struct *tty)
1190{
1191 struct uart_state *state = tty->driver_data;
1192 struct uart_port *uport = state->uart_port;
1193
1194 if (uport->ops->set_ldisc)
1195 uport->ops->set_ldisc(uport, tty->termios->c_line);
1196}
1197
1198static void uart_set_termios(struct tty_struct *tty,
1199 struct ktermios *old_termios)
1200{
1201 struct uart_state *state = tty->driver_data;
1202 unsigned long flags;
1203 unsigned int cflag = tty->termios->c_cflag;
1204
1205
1206 /*
1207 * These are the bits that are used to setup various
1208 * flags in the low level driver. We can ignore the Bfoo
1209 * bits in c_cflag; c_[io]speed will always be set
1210 * appropriately by set_termios() in tty_ioctl.c
1211 */
1212#define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1213 if ((cflag ^ old_termios->c_cflag) == 0 &&
1214 tty->termios->c_ospeed == old_termios->c_ospeed &&
1215 tty->termios->c_ispeed == old_termios->c_ispeed &&
1216 RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) {
1217 return;
1218 }
1219
1220 uart_change_speed(tty, state, old_termios);
1221
1222 /* Handle transition to B0 status */
1223 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1224 uart_clear_mctrl(state->uart_port, TIOCM_RTS | TIOCM_DTR);
1225 /* Handle transition away from B0 status */
1226 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1227 unsigned int mask = TIOCM_DTR;
1228 if (!(cflag & CRTSCTS) ||
1229 !test_bit(TTY_THROTTLED, &tty->flags))
1230 mask |= TIOCM_RTS;
1231 uart_set_mctrl(state->uart_port, mask);
1232 }
1233
1234 /* Handle turning off CRTSCTS */
1235 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1236 spin_lock_irqsave(&state->uart_port->lock, flags);
1237 tty->hw_stopped = 0;
1238 __uart_start(tty);
1239 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1240 }
1241 /* Handle turning on CRTSCTS */
1242 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1243 spin_lock_irqsave(&state->uart_port->lock, flags);
1244 if (!(state->uart_port->ops->get_mctrl(state->uart_port) & TIOCM_CTS)) {
1245 tty->hw_stopped = 1;
1246 state->uart_port->ops->stop_tx(state->uart_port);
1247 }
1248 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1249 }
1250}
1251
1252/*
1253 * In 2.4.5, calls to this will be serialized via the BKL in
1254 * linux/drivers/char/tty_io.c:tty_release()
1255 * linux/drivers/char/tty_io.c:do_tty_handup()
1256 */
1257static void uart_close(struct tty_struct *tty, struct file *filp)
1258{
1259 struct uart_state *state = tty->driver_data;
1260 struct tty_port *port;
1261 struct uart_port *uport;
1262 unsigned long flags;
1263
1264 BUG_ON(!tty_locked());
1265
1266 if (!state)
1267 return;
1268
1269 uport = state->uart_port;
1270 port = &state->port;
1271
1272 pr_debug("uart_close(%d) called\n", uport->line);
1273
1274 mutex_lock(&port->mutex);
1275 spin_lock_irqsave(&port->lock, flags);
1276
1277 if (tty_hung_up_p(filp)) {
1278 spin_unlock_irqrestore(&port->lock, flags);
1279 goto done;
1280 }
1281
1282 if ((tty->count == 1) && (port->count != 1)) {
1283 /*
1284 * Uh, oh. tty->count is 1, which means that the tty
1285 * structure will be freed. port->count should always
1286 * be one in these conditions. If it's greater than
1287 * one, we've got real problems, since it means the
1288 * serial port won't be shutdown.
1289 */
1290 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1291 "port->count is %d\n", port->count);
1292 port->count = 1;
1293 }
1294 if (--port->count < 0) {
1295 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1296 tty->name, port->count);
1297 port->count = 0;
1298 }
1299 if (port->count) {
1300 spin_unlock_irqrestore(&port->lock, flags);
1301 goto done;
1302 }
1303
1304 /*
1305 * Now we wait for the transmit buffer to clear; and we notify
1306 * the line discipline to only process XON/XOFF characters by
1307 * setting tty->closing.
1308 */
1309 tty->closing = 1;
1310 spin_unlock_irqrestore(&port->lock, flags);
1311
1312 if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) {
1313 /*
1314 * hack: open-coded tty_wait_until_sent to avoid
1315 * recursive tty_lock
1316 */
1317 long timeout = msecs_to_jiffies(port->closing_wait);
1318 if (wait_event_interruptible_timeout(tty->write_wait,
1319 !tty_chars_in_buffer(tty), timeout) >= 0)
1320 __uart_wait_until_sent(uport, timeout);
1321 }
1322
1323 /*
1324 * At this point, we stop accepting input. To do this, we
1325 * disable the receive line status interrupts.
1326 */
1327 if (port->flags & ASYNC_INITIALIZED) {
1328 unsigned long flags;
1329 spin_lock_irqsave(&uport->lock, flags);
1330 uport->ops->stop_rx(uport);
1331 spin_unlock_irqrestore(&uport->lock, flags);
1332 /*
1333 * Before we drop DTR, make sure the UART transmitter
1334 * has completely drained; this is especially
1335 * important if there is a transmit FIFO!
1336 */
1337 __uart_wait_until_sent(uport, uport->timeout);
1338 }
1339
1340 uart_shutdown(tty, state);
1341 uart_flush_buffer(tty);
1342
1343 tty_ldisc_flush(tty);
1344
1345 tty_port_tty_set(port, NULL);
1346 spin_lock_irqsave(&port->lock, flags);
1347 tty->closing = 0;
1348
1349 if (port->blocked_open) {
1350 spin_unlock_irqrestore(&port->lock, flags);
1351 if (port->close_delay)
1352 msleep_interruptible(port->close_delay);
1353 spin_lock_irqsave(&port->lock, flags);
1354 } else if (!uart_console(uport)) {
1355 spin_unlock_irqrestore(&port->lock, flags);
1356 uart_change_pm(state, 3);
1357 spin_lock_irqsave(&port->lock, flags);
1358 }
1359
1360 /*
1361 * Wake up anyone trying to open this port.
1362 */
1363 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1364 spin_unlock_irqrestore(&port->lock, flags);
1365 wake_up_interruptible(&port->open_wait);
1366
1367done:
1368 mutex_unlock(&port->mutex);
1369}
1370
1371static void __uart_wait_until_sent(struct uart_port *port, int timeout)
1372{
1373 unsigned long char_time, expire;
1374
1375 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1376 return;
1377
1378 /*
1379 * Set the check interval to be 1/5 of the estimated time to
1380 * send a single character, and make it at least 1. The check
1381 * interval should also be less than the timeout.
1382 *
1383 * Note: we have to use pretty tight timings here to satisfy
1384 * the NIST-PCTS.
1385 */
1386 char_time = (port->timeout - HZ/50) / port->fifosize;
1387 char_time = char_time / 5;
1388 if (char_time == 0)
1389 char_time = 1;
1390 if (timeout && timeout < char_time)
1391 char_time = timeout;
1392
1393 /*
1394 * If the transmitter hasn't cleared in twice the approximate
1395 * amount of time to send the entire FIFO, it probably won't
1396 * ever clear. This assumes the UART isn't doing flow
1397 * control, which is currently the case. Hence, if it ever
1398 * takes longer than port->timeout, this is probably due to a
1399 * UART bug of some kind. So, we clamp the timeout parameter at
1400 * 2*port->timeout.
1401 */
1402 if (timeout == 0 || timeout > 2 * port->timeout)
1403 timeout = 2 * port->timeout;
1404
1405 expire = jiffies + timeout;
1406
1407 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1408 port->line, jiffies, expire);
1409
1410 /*
1411 * Check whether the transmitter is empty every 'char_time'.
1412 * 'timeout' / 'expire' give us the maximum amount of time
1413 * we wait.
1414 */
1415 while (!port->ops->tx_empty(port)) {
1416 msleep_interruptible(jiffies_to_msecs(char_time));
1417 if (signal_pending(current))
1418 break;
1419 if (time_after(jiffies, expire))
1420 break;
1421 }
1422}
1423
1424static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1425{
1426 struct uart_state *state = tty->driver_data;
1427 struct uart_port *port = state->uart_port;
1428
1429 tty_lock();
1430 __uart_wait_until_sent(port, timeout);
1431 tty_unlock();
1432}
1433
1434/*
1435 * This is called with the BKL held in
1436 * linux/drivers/char/tty_io.c:do_tty_hangup()
1437 * We're called from the eventd thread, so we can sleep for
1438 * a _short_ time only.
1439 */
1440static void uart_hangup(struct tty_struct *tty)
1441{
1442 struct uart_state *state = tty->driver_data;
1443 struct tty_port *port = &state->port;
1444 unsigned long flags;
1445
1446 BUG_ON(!tty_locked());
1447 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1448
1449 mutex_lock(&port->mutex);
1450 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1451 uart_flush_buffer(tty);
1452 uart_shutdown(tty, state);
1453 spin_lock_irqsave(&port->lock, flags);
1454 port->count = 0;
1455 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1456 spin_unlock_irqrestore(&port->lock, flags);
1457 tty_port_tty_set(port, NULL);
1458 wake_up_interruptible(&port->open_wait);
1459 wake_up_interruptible(&port->delta_msr_wait);
1460 }
1461 mutex_unlock(&port->mutex);
1462}
1463
1464static int uart_carrier_raised(struct tty_port *port)
1465{
1466 struct uart_state *state = container_of(port, struct uart_state, port);
1467 struct uart_port *uport = state->uart_port;
1468 int mctrl;
1469 spin_lock_irq(&uport->lock);
1470 uport->ops->enable_ms(uport);
1471 mctrl = uport->ops->get_mctrl(uport);
1472 spin_unlock_irq(&uport->lock);
1473 if (mctrl & TIOCM_CAR)
1474 return 1;
1475 return 0;
1476}
1477
1478static void uart_dtr_rts(struct tty_port *port, int onoff)
1479{
1480 struct uart_state *state = container_of(port, struct uart_state, port);
1481 struct uart_port *uport = state->uart_port;
1482
1483 if (onoff)
1484 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1485 else
1486 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1487}
1488
1489static struct uart_state *uart_get(struct uart_driver *drv, int line)
1490{
1491 struct uart_state *state;
1492 struct tty_port *port;
1493 int ret = 0;
1494
1495 state = drv->state + line;
1496 port = &state->port;
1497 if (mutex_lock_interruptible(&port->mutex)) {
1498 ret = -ERESTARTSYS;
1499 goto err;
1500 }
1501
1502 port->count++;
1503 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1504 ret = -ENXIO;
1505 goto err_unlock;
1506 }
1507 return state;
1508
1509 err_unlock:
1510 port->count--;
1511 mutex_unlock(&port->mutex);
1512 err:
1513 return ERR_PTR(ret);
1514}
1515
1516/*
1517 * calls to uart_open are serialised by the BKL in
1518 * fs/char_dev.c:chrdev_open()
1519 * Note that if this fails, then uart_close() _will_ be called.
1520 *
1521 * In time, we want to scrap the "opening nonpresent ports"
1522 * behaviour and implement an alternative way for setserial
1523 * to set base addresses/ports/types. This will allow us to
1524 * get rid of a certain amount of extra tests.
1525 */
1526static int uart_open(struct tty_struct *tty, struct file *filp)
1527{
1528 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1529 struct uart_state *state;
1530 struct tty_port *port;
1531 int retval, line = tty->index;
1532
1533 BUG_ON(!tty_locked());
1534 pr_debug("uart_open(%d) called\n", line);
1535
1536 /*
1537 * We take the semaphore inside uart_get to guarantee that we won't
1538 * be re-entered while allocating the state structure, or while we
1539 * request any IRQs that the driver may need. This also has the nice
1540 * side-effect that it delays the action of uart_hangup, so we can
1541 * guarantee that state->port.tty will always contain something
1542 * reasonable.
1543 */
1544 state = uart_get(drv, line);
1545 if (IS_ERR(state)) {
1546 retval = PTR_ERR(state);
1547 goto fail;
1548 }
1549 port = &state->port;
1550
1551 /*
1552 * Once we set tty->driver_data here, we are guaranteed that
1553 * uart_close() will decrement the driver module use count.
1554 * Any failures from here onwards should not touch the count.
1555 */
1556 tty->driver_data = state;
1557 state->uart_port->state = state;
1558 tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1559 tty->alt_speed = 0;
1560 tty_port_tty_set(port, tty);
1561
1562 /*
1563 * If the port is in the middle of closing, bail out now.
1564 */
1565 if (tty_hung_up_p(filp)) {
1566 retval = -EAGAIN;
1567 port->count--;
1568 mutex_unlock(&port->mutex);
1569 goto fail;
1570 }
1571
1572 /*
1573 * Make sure the device is in D0 state.
1574 */
1575 if (port->count == 1)
1576 uart_change_pm(state, 0);
1577
1578 /*
1579 * Start up the serial port.
1580 */
1581 retval = uart_startup(tty, state, 0);
1582
1583 /*
1584 * If we succeeded, wait until the port is ready.
1585 */
1586 mutex_unlock(&port->mutex);
1587 if (retval == 0)
1588 retval = tty_port_block_til_ready(port, tty, filp);
1589
1590fail:
1591 return retval;
1592}
1593
1594static const char *uart_type(struct uart_port *port)
1595{
1596 const char *str = NULL;
1597
1598 if (port->ops->type)
1599 str = port->ops->type(port);
1600
1601 if (!str)
1602 str = "unknown";
1603
1604 return str;
1605}
1606
1607#ifdef CONFIG_PROC_FS
1608
1609static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1610{
1611 struct uart_state *state = drv->state + i;
1612 struct tty_port *port = &state->port;
1613 int pm_state;
1614 struct uart_port *uport = state->uart_port;
1615 char stat_buf[32];
1616 unsigned int status;
1617 int mmio;
1618
1619 if (!uport)
1620 return;
1621
1622 mmio = uport->iotype >= UPIO_MEM;
1623 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1624 uport->line, uart_type(uport),
1625 mmio ? "mmio:0x" : "port:",
1626 mmio ? (unsigned long long)uport->mapbase
1627 : (unsigned long long)uport->iobase,
1628 uport->irq);
1629
1630 if (uport->type == PORT_UNKNOWN) {
1631 seq_putc(m, '\n');
1632 return;
1633 }
1634
1635 if (capable(CAP_SYS_ADMIN)) {
1636 mutex_lock(&port->mutex);
1637 pm_state = state->pm_state;
1638 if (pm_state)
1639 uart_change_pm(state, 0);
1640 spin_lock_irq(&uport->lock);
1641 status = uport->ops->get_mctrl(uport);
1642 spin_unlock_irq(&uport->lock);
1643 if (pm_state)
1644 uart_change_pm(state, pm_state);
1645 mutex_unlock(&port->mutex);
1646
1647 seq_printf(m, " tx:%d rx:%d",
1648 uport->icount.tx, uport->icount.rx);
1649 if (uport->icount.frame)
1650 seq_printf(m, " fe:%d",
1651 uport->icount.frame);
1652 if (uport->icount.parity)
1653 seq_printf(m, " pe:%d",
1654 uport->icount.parity);
1655 if (uport->icount.brk)
1656 seq_printf(m, " brk:%d",
1657 uport->icount.brk);
1658 if (uport->icount.overrun)
1659 seq_printf(m, " oe:%d",
1660 uport->icount.overrun);
1661
1662#define INFOBIT(bit, str) \
1663 if (uport->mctrl & (bit)) \
1664 strncat(stat_buf, (str), sizeof(stat_buf) - \
1665 strlen(stat_buf) - 2)
1666#define STATBIT(bit, str) \
1667 if (status & (bit)) \
1668 strncat(stat_buf, (str), sizeof(stat_buf) - \
1669 strlen(stat_buf) - 2)
1670
1671 stat_buf[0] = '\0';
1672 stat_buf[1] = '\0';
1673 INFOBIT(TIOCM_RTS, "|RTS");
1674 STATBIT(TIOCM_CTS, "|CTS");
1675 INFOBIT(TIOCM_DTR, "|DTR");
1676 STATBIT(TIOCM_DSR, "|DSR");
1677 STATBIT(TIOCM_CAR, "|CD");
1678 STATBIT(TIOCM_RNG, "|RI");
1679 if (stat_buf[0])
1680 stat_buf[0] = ' ';
1681
1682 seq_puts(m, stat_buf);
1683 }
1684 seq_putc(m, '\n');
1685#undef STATBIT
1686#undef INFOBIT
1687}
1688
1689static int uart_proc_show(struct seq_file *m, void *v)
1690{
1691 struct tty_driver *ttydrv = m->private;
1692 struct uart_driver *drv = ttydrv->driver_state;
1693 int i;
1694
1695 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1696 "", "", "");
1697 for (i = 0; i < drv->nr; i++)
1698 uart_line_info(m, drv, i);
1699 return 0;
1700}
1701
1702static int uart_proc_open(struct inode *inode, struct file *file)
1703{
1704 return single_open(file, uart_proc_show, PDE(inode)->data);
1705}
1706
1707static const struct file_operations uart_proc_fops = {
1708 .owner = THIS_MODULE,
1709 .open = uart_proc_open,
1710 .read = seq_read,
1711 .llseek = seq_lseek,
1712 .release = single_release,
1713};
1714#endif
1715
1716#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1717/*
1718 * uart_console_write - write a console message to a serial port
1719 * @port: the port to write the message
1720 * @s: array of characters
1721 * @count: number of characters in string to write
1722 * @write: function to write character to port
1723 */
1724void uart_console_write(struct uart_port *port, const char *s,
1725 unsigned int count,
1726 void (*putchar)(struct uart_port *, int))
1727{
1728 unsigned int i;
1729
1730 for (i = 0; i < count; i++, s++) {
1731 if (*s == '\n')
1732 putchar(port, '\r');
1733 putchar(port, *s);
1734 }
1735}
1736EXPORT_SYMBOL_GPL(uart_console_write);
1737
1738/*
1739 * Check whether an invalid uart number has been specified, and
1740 * if so, search for the first available port that does have
1741 * console support.
1742 */
1743struct uart_port * __init
1744uart_get_console(struct uart_port *ports, int nr, struct console *co)
1745{
1746 int idx = co->index;
1747
1748 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1749 ports[idx].membase == NULL))
1750 for (idx = 0; idx < nr; idx++)
1751 if (ports[idx].iobase != 0 ||
1752 ports[idx].membase != NULL)
1753 break;
1754
1755 co->index = idx;
1756
1757 return ports + idx;
1758}
1759
1760/**
1761 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1762 * @options: pointer to option string
1763 * @baud: pointer to an 'int' variable for the baud rate.
1764 * @parity: pointer to an 'int' variable for the parity.
1765 * @bits: pointer to an 'int' variable for the number of data bits.
1766 * @flow: pointer to an 'int' variable for the flow control character.
1767 *
1768 * uart_parse_options decodes a string containing the serial console
1769 * options. The format of the string is <baud><parity><bits><flow>,
1770 * eg: 115200n8r
1771 */
1772void
1773uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1774{
1775 char *s = options;
1776
1777 *baud = simple_strtoul(s, NULL, 10);
1778 while (*s >= '0' && *s <= '9')
1779 s++;
1780 if (*s)
1781 *parity = *s++;
1782 if (*s)
1783 *bits = *s++ - '0';
1784 if (*s)
1785 *flow = *s;
1786}
1787EXPORT_SYMBOL_GPL(uart_parse_options);
1788
1789struct baud_rates {
1790 unsigned int rate;
1791 unsigned int cflag;
1792};
1793
1794static const struct baud_rates baud_rates[] = {
1795 { 921600, B921600 },
1796 { 460800, B460800 },
1797 { 230400, B230400 },
1798 { 115200, B115200 },
1799 { 57600, B57600 },
1800 { 38400, B38400 },
1801 { 19200, B19200 },
1802 { 9600, B9600 },
1803 { 4800, B4800 },
1804 { 2400, B2400 },
1805 { 1200, B1200 },
1806 { 0, B38400 }
1807};
1808
1809/**
1810 * uart_set_options - setup the serial console parameters
1811 * @port: pointer to the serial ports uart_port structure
1812 * @co: console pointer
1813 * @baud: baud rate
1814 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1815 * @bits: number of data bits
1816 * @flow: flow control character - 'r' (rts)
1817 */
1818int
1819uart_set_options(struct uart_port *port, struct console *co,
1820 int baud, int parity, int bits, int flow)
1821{
1822 struct ktermios termios;
1823 static struct ktermios dummy;
1824 int i;
1825
1826 /*
1827 * Ensure that the serial console lock is initialised
1828 * early.
1829 */
1830 spin_lock_init(&port->lock);
1831 lockdep_set_class(&port->lock, &port_lock_key);
1832
1833 memset(&termios, 0, sizeof(struct ktermios));
1834
1835 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1836
1837 /*
1838 * Construct a cflag setting.
1839 */
1840 for (i = 0; baud_rates[i].rate; i++)
1841 if (baud_rates[i].rate <= baud)
1842 break;
1843
1844 termios.c_cflag |= baud_rates[i].cflag;
1845
1846 if (bits == 7)
1847 termios.c_cflag |= CS7;
1848 else
1849 termios.c_cflag |= CS8;
1850
1851 switch (parity) {
1852 case 'o': case 'O':
1853 termios.c_cflag |= PARODD;
1854 /*fall through*/
1855 case 'e': case 'E':
1856 termios.c_cflag |= PARENB;
1857 break;
1858 }
1859
1860 if (flow == 'r')
1861 termios.c_cflag |= CRTSCTS;
1862
1863 /*
1864 * some uarts on other side don't support no flow control.
1865 * So we set * DTR in host uart to make them happy
1866 */
1867 port->mctrl |= TIOCM_DTR;
1868
1869 port->ops->set_termios(port, &termios, &dummy);
1870 /*
1871 * Allow the setting of the UART parameters with a NULL console
1872 * too:
1873 */
1874 if (co)
1875 co->cflag = termios.c_cflag;
1876
1877 return 0;
1878}
1879EXPORT_SYMBOL_GPL(uart_set_options);
1880#endif /* CONFIG_SERIAL_CORE_CONSOLE */
1881
1882static void uart_change_pm(struct uart_state *state, int pm_state)
1883{
1884 struct uart_port *port = state->uart_port;
1885
1886 if (state->pm_state != pm_state) {
1887 if (port->ops->pm)
1888 port->ops->pm(port, pm_state, state->pm_state);
1889 state->pm_state = pm_state;
1890 }
1891}
1892
1893struct uart_match {
1894 struct uart_port *port;
1895 struct uart_driver *driver;
1896};
1897
1898static int serial_match_port(struct device *dev, void *data)
1899{
1900 struct uart_match *match = data;
1901 struct tty_driver *tty_drv = match->driver->tty_driver;
1902 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1903 match->port->line;
1904
1905 return dev->devt == devt; /* Actually, only one tty per port */
1906}
1907
1908int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1909{
1910 struct uart_state *state = drv->state + uport->line;
1911 struct tty_port *port = &state->port;
1912 struct device *tty_dev;
1913 struct uart_match match = {uport, drv};
1914
1915 mutex_lock(&port->mutex);
1916
1917 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1918 if (device_may_wakeup(tty_dev)) {
1919 if (!enable_irq_wake(uport->irq))
1920 uport->irq_wake = 1;
1921 put_device(tty_dev);
1922 mutex_unlock(&port->mutex);
1923 return 0;
1924 }
1925 if (console_suspend_enabled || !uart_console(uport))
1926 uport->suspended = 1;
1927
1928 if (port->flags & ASYNC_INITIALIZED) {
1929 const struct uart_ops *ops = uport->ops;
1930 int tries;
1931
1932 if (console_suspend_enabled || !uart_console(uport)) {
1933 set_bit(ASYNCB_SUSPENDED, &port->flags);
1934 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1935
1936 spin_lock_irq(&uport->lock);
1937 ops->stop_tx(uport);
1938 ops->set_mctrl(uport, 0);
1939 ops->stop_rx(uport);
1940 spin_unlock_irq(&uport->lock);
1941 }
1942
1943 /*
1944 * Wait for the transmitter to empty.
1945 */
1946 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1947 msleep(10);
1948 if (!tries)
1949 printk(KERN_ERR "%s%s%s%d: Unable to drain "
1950 "transmitter\n",
1951 uport->dev ? dev_name(uport->dev) : "",
1952 uport->dev ? ": " : "",
1953 drv->dev_name,
1954 drv->tty_driver->name_base + uport->line);
1955
1956 if (console_suspend_enabled || !uart_console(uport))
1957 ops->shutdown(uport);
1958 }
1959
1960 /*
1961 * Disable the console device before suspending.
1962 */
1963 if (console_suspend_enabled && uart_console(uport))
1964 console_stop(uport->cons);
1965
1966 if (console_suspend_enabled || !uart_console(uport))
1967 uart_change_pm(state, 3);
1968
1969 mutex_unlock(&port->mutex);
1970
1971 return 0;
1972}
1973
1974int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1975{
1976 struct uart_state *state = drv->state + uport->line;
1977 struct tty_port *port = &state->port;
1978 struct device *tty_dev;
1979 struct uart_match match = {uport, drv};
1980 struct ktermios termios;
1981
1982 mutex_lock(&port->mutex);
1983
1984 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1985 if (!uport->suspended && device_may_wakeup(tty_dev)) {
1986 if (uport->irq_wake) {
1987 disable_irq_wake(uport->irq);
1988 uport->irq_wake = 0;
1989 }
1990 mutex_unlock(&port->mutex);
1991 return 0;
1992 }
1993 uport->suspended = 0;
1994
1995 /*
1996 * Re-enable the console device after suspending.
1997 */
1998 if (uart_console(uport)) {
1999 /*
2000 * First try to use the console cflag setting.
2001 */
2002 memset(&termios, 0, sizeof(struct ktermios));
2003 termios.c_cflag = uport->cons->cflag;
2004
2005 /*
2006 * If that's unset, use the tty termios setting.
2007 */
2008 if (port->tty && port->tty->termios && termios.c_cflag == 0)
2009 termios = *(port->tty->termios);
2010
2011 uport->ops->set_termios(uport, &termios, NULL);
2012 if (console_suspend_enabled)
2013 console_start(uport->cons);
2014 }
2015
2016 if (port->flags & ASYNC_SUSPENDED) {
2017 const struct uart_ops *ops = uport->ops;
2018 int ret;
2019
2020 uart_change_pm(state, 0);
2021 spin_lock_irq(&uport->lock);
2022 ops->set_mctrl(uport, 0);
2023 spin_unlock_irq(&uport->lock);
2024 if (console_suspend_enabled || !uart_console(uport)) {
2025 /* Protected by port mutex for now */
2026 struct tty_struct *tty = port->tty;
2027 ret = ops->startup(uport);
2028 if (ret == 0) {
2029 if (tty)
2030 uart_change_speed(tty, state, NULL);
2031 spin_lock_irq(&uport->lock);
2032 ops->set_mctrl(uport, uport->mctrl);
2033 ops->start_tx(uport);
2034 spin_unlock_irq(&uport->lock);
2035 set_bit(ASYNCB_INITIALIZED, &port->flags);
2036 } else {
2037 /*
2038 * Failed to resume - maybe hardware went away?
2039 * Clear the "initialized" flag so we won't try
2040 * to call the low level drivers shutdown method.
2041 */
2042 uart_shutdown(tty, state);
2043 }
2044 }
2045
2046 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2047 }
2048
2049 mutex_unlock(&port->mutex);
2050
2051 return 0;
2052}
2053
2054static inline void
2055uart_report_port(struct uart_driver *drv, struct uart_port *port)
2056{
2057 char address[64];
2058
2059 switch (port->iotype) {
2060 case UPIO_PORT:
2061 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2062 break;
2063 case UPIO_HUB6:
2064 snprintf(address, sizeof(address),
2065 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2066 break;
2067 case UPIO_MEM:
2068 case UPIO_MEM32:
2069 case UPIO_AU:
2070 case UPIO_TSI:
2071 case UPIO_DWAPB:
2072 case UPIO_DWAPB32:
2073 snprintf(address, sizeof(address),
2074 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2075 break;
2076 default:
2077 strlcpy(address, "*unknown*", sizeof(address));
2078 break;
2079 }
2080
2081 printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2082 port->dev ? dev_name(port->dev) : "",
2083 port->dev ? ": " : "",
2084 drv->dev_name,
2085 drv->tty_driver->name_base + port->line,
2086 address, port->irq, uart_type(port));
2087}
2088
2089static void
2090uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2091 struct uart_port *port)
2092{
2093 unsigned int flags;
2094
2095 /*
2096 * If there isn't a port here, don't do anything further.
2097 */
2098 if (!port->iobase && !port->mapbase && !port->membase)
2099 return;
2100
2101 /*
2102 * Now do the auto configuration stuff. Note that config_port
2103 * is expected to claim the resources and map the port for us.
2104 */
2105 flags = 0;
2106 if (port->flags & UPF_AUTO_IRQ)
2107 flags |= UART_CONFIG_IRQ;
2108 if (port->flags & UPF_BOOT_AUTOCONF) {
2109 if (!(port->flags & UPF_FIXED_TYPE)) {
2110 port->type = PORT_UNKNOWN;
2111 flags |= UART_CONFIG_TYPE;
2112 }
2113 port->ops->config_port(port, flags);
2114 }
2115
2116 if (port->type != PORT_UNKNOWN) {
2117 unsigned long flags;
2118
2119 uart_report_port(drv, port);
2120
2121 /* Power up port for set_mctrl() */
2122 uart_change_pm(state, 0);
2123
2124 /*
2125 * Ensure that the modem control lines are de-activated.
2126 * keep the DTR setting that is set in uart_set_options()
2127 * We probably don't need a spinlock around this, but
2128 */
2129 spin_lock_irqsave(&port->lock, flags);
2130 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2131 spin_unlock_irqrestore(&port->lock, flags);
2132
2133 /*
2134 * If this driver supports console, and it hasn't been
2135 * successfully registered yet, try to re-register it.
2136 * It may be that the port was not available.
2137 */
2138 if (port->cons && !(port->cons->flags & CON_ENABLED))
2139 register_console(port->cons);
2140
2141 /*
2142 * Power down all ports by default, except the
2143 * console if we have one.
2144 */
2145 if (!uart_console(port))
2146 uart_change_pm(state, 3);
2147 }
2148}
2149
2150#ifdef CONFIG_CONSOLE_POLL
2151
2152static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2153{
2154 struct uart_driver *drv = driver->driver_state;
2155 struct uart_state *state = drv->state + line;
2156 struct uart_port *port;
2157 int baud = 9600;
2158 int bits = 8;
2159 int parity = 'n';
2160 int flow = 'n';
2161
2162 if (!state || !state->uart_port)
2163 return -1;
2164
2165 port = state->uart_port;
2166 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2167 return -1;
2168
2169 if (options) {
2170 uart_parse_options(options, &baud, &parity, &bits, &flow);
2171 return uart_set_options(port, NULL, baud, parity, bits, flow);
2172 }
2173
2174 return 0;
2175}
2176
2177static int uart_poll_get_char(struct tty_driver *driver, int line)
2178{
2179 struct uart_driver *drv = driver->driver_state;
2180 struct uart_state *state = drv->state + line;
2181 struct uart_port *port;
2182
2183 if (!state || !state->uart_port)
2184 return -1;
2185
2186 port = state->uart_port;
2187 return port->ops->poll_get_char(port);
2188}
2189
2190static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2191{
2192 struct uart_driver *drv = driver->driver_state;
2193 struct uart_state *state = drv->state + line;
2194 struct uart_port *port;
2195
2196 if (!state || !state->uart_port)
2197 return;
2198
2199 port = state->uart_port;
2200 port->ops->poll_put_char(port, ch);
2201}
2202#endif
2203
2204static const struct tty_operations uart_ops = {
2205 .open = uart_open,
2206 .close = uart_close,
2207 .write = uart_write,
2208 .put_char = uart_put_char,
2209 .flush_chars = uart_flush_chars,
2210 .write_room = uart_write_room,
2211 .chars_in_buffer= uart_chars_in_buffer,
2212 .flush_buffer = uart_flush_buffer,
2213 .ioctl = uart_ioctl,
2214 .throttle = uart_throttle,
2215 .unthrottle = uart_unthrottle,
2216 .send_xchar = uart_send_xchar,
2217 .set_termios = uart_set_termios,
2218 .set_ldisc = uart_set_ldisc,
2219 .stop = uart_stop,
2220 .start = uart_start,
2221 .hangup = uart_hangup,
2222 .break_ctl = uart_break_ctl,
2223 .wait_until_sent= uart_wait_until_sent,
2224#ifdef CONFIG_PROC_FS
2225 .proc_fops = &uart_proc_fops,
2226#endif
2227 .tiocmget = uart_tiocmget,
2228 .tiocmset = uart_tiocmset,
2229 .get_icount = uart_get_icount,
2230#ifdef CONFIG_CONSOLE_POLL
2231 .poll_init = uart_poll_init,
2232 .poll_get_char = uart_poll_get_char,
2233 .poll_put_char = uart_poll_put_char,
2234#endif
2235};
2236
2237static const struct tty_port_operations uart_port_ops = {
2238 .carrier_raised = uart_carrier_raised,
2239 .dtr_rts = uart_dtr_rts,
2240};
2241
2242/**
2243 * uart_register_driver - register a driver with the uart core layer
2244 * @drv: low level driver structure
2245 *
2246 * Register a uart driver with the core driver. We in turn register
2247 * with the tty layer, and initialise the core driver per-port state.
2248 *
2249 * We have a proc file in /proc/tty/driver which is named after the
2250 * normal driver.
2251 *
2252 * drv->port should be NULL, and the per-port structures should be
2253 * registered using uart_add_one_port after this call has succeeded.
2254 */
2255int uart_register_driver(struct uart_driver *drv)
2256{
2257 struct tty_driver *normal;
2258 int i, retval;
2259
2260 BUG_ON(drv->state);
2261
2262 /*
2263 * Maybe we should be using a slab cache for this, especially if
2264 * we have a large number of ports to handle.
2265 */
2266 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2267 if (!drv->state)
2268 goto out;
2269
2270 normal = alloc_tty_driver(drv->nr);
2271 if (!normal)
2272 goto out_kfree;
2273
2274 drv->tty_driver = normal;
2275
2276 normal->owner = drv->owner;
2277 normal->driver_name = drv->driver_name;
2278 normal->name = drv->dev_name;
2279 normal->major = drv->major;
2280 normal->minor_start = drv->minor;
2281 normal->type = TTY_DRIVER_TYPE_SERIAL;
2282 normal->subtype = SERIAL_TYPE_NORMAL;
2283 normal->init_termios = tty_std_termios;
2284 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2285 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2286 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2287 normal->driver_state = drv;
2288 tty_set_operations(normal, &uart_ops);
2289
2290 /*
2291 * Initialise the UART state(s).
2292 */
2293 for (i = 0; i < drv->nr; i++) {
2294 struct uart_state *state = drv->state + i;
2295 struct tty_port *port = &state->port;
2296
2297 tty_port_init(port);
2298 port->ops = &uart_port_ops;
2299 port->close_delay = 500; /* .5 seconds */
2300 port->closing_wait = 30000; /* 30 seconds */
2301 tasklet_init(&state->tlet, uart_tasklet_action,
2302 (unsigned long)state);
2303 }
2304
2305 retval = tty_register_driver(normal);
2306 if (retval >= 0)
2307 return retval;
2308
2309 put_tty_driver(normal);
2310out_kfree:
2311 kfree(drv->state);
2312out:
2313 return -ENOMEM;
2314}
2315
2316/**
2317 * uart_unregister_driver - remove a driver from the uart core layer
2318 * @drv: low level driver structure
2319 *
2320 * Remove all references to a driver from the core driver. The low
2321 * level driver must have removed all its ports via the
2322 * uart_remove_one_port() if it registered them with uart_add_one_port().
2323 * (ie, drv->port == NULL)
2324 */
2325void uart_unregister_driver(struct uart_driver *drv)
2326{
2327 struct tty_driver *p = drv->tty_driver;
2328 tty_unregister_driver(p);
2329 put_tty_driver(p);
2330 kfree(drv->state);
2331 drv->tty_driver = NULL;
2332}
2333
2334struct tty_driver *uart_console_device(struct console *co, int *index)
2335{
2336 struct uart_driver *p = co->data;
2337 *index = co->index;
2338 return p->tty_driver;
2339}
2340
2341/**
2342 * uart_add_one_port - attach a driver-defined port structure
2343 * @drv: pointer to the uart low level driver structure for this port
2344 * @uport: uart port structure to use for this port.
2345 *
2346 * This allows the driver to register its own uart_port structure
2347 * with the core driver. The main purpose is to allow the low
2348 * level uart drivers to expand uart_port, rather than having yet
2349 * more levels of structures.
2350 */
2351int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2352{
2353 struct uart_state *state;
2354 struct tty_port *port;
2355 int ret = 0;
2356 struct device *tty_dev;
2357
2358 BUG_ON(in_interrupt());
2359
2360 if (uport->line >= drv->nr)
2361 return -EINVAL;
2362
2363 state = drv->state + uport->line;
2364 port = &state->port;
2365
2366 mutex_lock(&port_mutex);
2367 mutex_lock(&port->mutex);
2368 if (state->uart_port) {
2369 ret = -EINVAL;
2370 goto out;
2371 }
2372
2373 state->uart_port = uport;
2374 state->pm_state = -1;
2375
2376 uport->cons = drv->cons;
2377 uport->state = state;
2378
2379 /*
2380 * If this port is a console, then the spinlock is already
2381 * initialised.
2382 */
2383 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2384 spin_lock_init(&uport->lock);
2385 lockdep_set_class(&uport->lock, &port_lock_key);
2386 }
2387
2388 uart_configure_port(drv, state, uport);
2389
2390 /*
2391 * Register the port whether it's detected or not. This allows
2392 * setserial to be used to alter this ports parameters.
2393 */
2394 tty_dev = tty_register_device(drv->tty_driver, uport->line, uport->dev);
2395 if (likely(!IS_ERR(tty_dev))) {
2396 device_init_wakeup(tty_dev, 1);
2397 device_set_wakeup_enable(tty_dev, 0);
2398 } else
2399 printk(KERN_ERR "Cannot register tty device on line %d\n",
2400 uport->line);
2401
2402 /*
2403 * Ensure UPF_DEAD is not set.
2404 */
2405 uport->flags &= ~UPF_DEAD;
2406
2407 out:
2408 mutex_unlock(&port->mutex);
2409 mutex_unlock(&port_mutex);
2410
2411 return ret;
2412}
2413
2414/**
2415 * uart_remove_one_port - detach a driver defined port structure
2416 * @drv: pointer to the uart low level driver structure for this port
2417 * @uport: uart port structure for this port
2418 *
2419 * This unhooks (and hangs up) the specified port structure from the
2420 * core driver. No further calls will be made to the low-level code
2421 * for this port.
2422 */
2423int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2424{
2425 struct uart_state *state = drv->state + uport->line;
2426 struct tty_port *port = &state->port;
2427
2428 BUG_ON(in_interrupt());
2429
2430 if (state->uart_port != uport)
2431 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2432 state->uart_port, uport);
2433
2434 mutex_lock(&port_mutex);
2435
2436 /*
2437 * Mark the port "dead" - this prevents any opens from
2438 * succeeding while we shut down the port.
2439 */
2440 mutex_lock(&port->mutex);
2441 uport->flags |= UPF_DEAD;
2442 mutex_unlock(&port->mutex);
2443
2444 /*
2445 * Remove the devices from the tty layer
2446 */
2447 tty_unregister_device(drv->tty_driver, uport->line);
2448
2449 if (port->tty)
2450 tty_vhangup(port->tty);
2451
2452 /*
2453 * Free the port IO and memory resources, if any.
2454 */
2455 if (uport->type != PORT_UNKNOWN)
2456 uport->ops->release_port(uport);
2457
2458 /*
2459 * Indicate that there isn't a port here anymore.
2460 */
2461 uport->type = PORT_UNKNOWN;
2462
2463 /*
2464 * Kill the tasklet, and free resources.
2465 */
2466 tasklet_kill(&state->tlet);
2467
2468 state->uart_port = NULL;
2469 mutex_unlock(&port_mutex);
2470
2471 return 0;
2472}
2473
2474/*
2475 * Are the two ports equivalent?
2476 */
2477int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2478{
2479 if (port1->iotype != port2->iotype)
2480 return 0;
2481
2482 switch (port1->iotype) {
2483 case UPIO_PORT:
2484 return (port1->iobase == port2->iobase);
2485 case UPIO_HUB6:
2486 return (port1->iobase == port2->iobase) &&
2487 (port1->hub6 == port2->hub6);
2488 case UPIO_MEM:
2489 case UPIO_MEM32:
2490 case UPIO_AU:
2491 case UPIO_TSI:
2492 case UPIO_DWAPB:
2493 case UPIO_DWAPB32:
2494 return (port1->mapbase == port2->mapbase);
2495 }
2496 return 0;
2497}
2498EXPORT_SYMBOL(uart_match_port);
2499
2500EXPORT_SYMBOL(uart_write_wakeup);
2501EXPORT_SYMBOL(uart_register_driver);
2502EXPORT_SYMBOL(uart_unregister_driver);
2503EXPORT_SYMBOL(uart_suspend_port);
2504EXPORT_SYMBOL(uart_resume_port);
2505EXPORT_SYMBOL(uart_add_one_port);
2506EXPORT_SYMBOL(uart_remove_one_port);
2507
2508MODULE_DESCRIPTION("Serial driver core");
2509MODULE_LICENSE("GPL");
1/*
2 * Driver core for serial ports
3 *
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
5 *
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 */
23#include <linux/module.h>
24#include <linux/tty.h>
25#include <linux/tty_flip.h>
26#include <linux/slab.h>
27#include <linux/init.h>
28#include <linux/console.h>
29#include <linux/of.h>
30#include <linux/proc_fs.h>
31#include <linux/seq_file.h>
32#include <linux/device.h>
33#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
34#include <linux/serial_core.h>
35#include <linux/delay.h>
36#include <linux/mutex.h>
37
38#include <asm/irq.h>
39#include <asm/uaccess.h>
40
41/*
42 * This is used to lock changes in serial line configuration.
43 */
44static DEFINE_MUTEX(port_mutex);
45
46/*
47 * lockdep: port->lock is initialized in two places, but we
48 * want only one lock-class:
49 */
50static struct lock_class_key port_lock_key;
51
52#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
53
54static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
55 struct ktermios *old_termios);
56static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
57static void uart_change_pm(struct uart_state *state,
58 enum uart_pm_state pm_state);
59
60static void uart_port_shutdown(struct tty_port *port);
61
62static int uart_dcd_enabled(struct uart_port *uport)
63{
64 return !!(uport->status & UPSTAT_DCD_ENABLE);
65}
66
67/*
68 * This routine is used by the interrupt handler to schedule processing in
69 * the software interrupt portion of the driver.
70 */
71void uart_write_wakeup(struct uart_port *port)
72{
73 struct uart_state *state = port->state;
74 /*
75 * This means you called this function _after_ the port was
76 * closed. No cookie for you.
77 */
78 BUG_ON(!state);
79 tty_wakeup(state->port.tty);
80}
81
82static void uart_stop(struct tty_struct *tty)
83{
84 struct uart_state *state = tty->driver_data;
85 struct uart_port *port = state->uart_port;
86 unsigned long flags;
87
88 spin_lock_irqsave(&port->lock, flags);
89 port->ops->stop_tx(port);
90 spin_unlock_irqrestore(&port->lock, flags);
91}
92
93static void __uart_start(struct tty_struct *tty)
94{
95 struct uart_state *state = tty->driver_data;
96 struct uart_port *port = state->uart_port;
97
98 if (!uart_tx_stopped(port))
99 port->ops->start_tx(port);
100}
101
102static void uart_start(struct tty_struct *tty)
103{
104 struct uart_state *state = tty->driver_data;
105 struct uart_port *port = state->uart_port;
106 unsigned long flags;
107
108 spin_lock_irqsave(&port->lock, flags);
109 __uart_start(tty);
110 spin_unlock_irqrestore(&port->lock, flags);
111}
112
113static void
114uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
115{
116 unsigned long flags;
117 unsigned int old;
118
119 spin_lock_irqsave(&port->lock, flags);
120 old = port->mctrl;
121 port->mctrl = (old & ~clear) | set;
122 if (old != port->mctrl)
123 port->ops->set_mctrl(port, port->mctrl);
124 spin_unlock_irqrestore(&port->lock, flags);
125}
126
127#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
128#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
129
130/*
131 * Startup the port. This will be called once per open. All calls
132 * will be serialised by the per-port mutex.
133 */
134static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
135 int init_hw)
136{
137 struct uart_port *uport = state->uart_port;
138 unsigned long page;
139 int retval = 0;
140
141 if (uport->type == PORT_UNKNOWN)
142 return 1;
143
144 /*
145 * Make sure the device is in D0 state.
146 */
147 uart_change_pm(state, UART_PM_STATE_ON);
148
149 /*
150 * Initialise and allocate the transmit and temporary
151 * buffer.
152 */
153 if (!state->xmit.buf) {
154 /* This is protected by the per port mutex */
155 page = get_zeroed_page(GFP_KERNEL);
156 if (!page)
157 return -ENOMEM;
158
159 state->xmit.buf = (unsigned char *) page;
160 uart_circ_clear(&state->xmit);
161 }
162
163 retval = uport->ops->startup(uport);
164 if (retval == 0) {
165 if (uart_console(uport) && uport->cons->cflag) {
166 tty->termios.c_cflag = uport->cons->cflag;
167 uport->cons->cflag = 0;
168 }
169 /*
170 * Initialise the hardware port settings.
171 */
172 uart_change_speed(tty, state, NULL);
173
174 /*
175 * Setup the RTS and DTR signals once the
176 * port is open and ready to respond.
177 */
178 if (init_hw && C_BAUD(tty))
179 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
180 }
181
182 /*
183 * This is to allow setserial on this port. People may want to set
184 * port/irq/type and then reconfigure the port properly if it failed
185 * now.
186 */
187 if (retval && capable(CAP_SYS_ADMIN))
188 return 1;
189
190 return retval;
191}
192
193static int uart_startup(struct tty_struct *tty, struct uart_state *state,
194 int init_hw)
195{
196 struct tty_port *port = &state->port;
197 int retval;
198
199 if (port->flags & ASYNC_INITIALIZED)
200 return 0;
201
202 /*
203 * Set the TTY IO error marker - we will only clear this
204 * once we have successfully opened the port.
205 */
206 set_bit(TTY_IO_ERROR, &tty->flags);
207
208 retval = uart_port_startup(tty, state, init_hw);
209 if (!retval) {
210 set_bit(ASYNCB_INITIALIZED, &port->flags);
211 clear_bit(TTY_IO_ERROR, &tty->flags);
212 } else if (retval > 0)
213 retval = 0;
214
215 return retval;
216}
217
218/*
219 * This routine will shutdown a serial port; interrupts are disabled, and
220 * DTR is dropped if the hangup on close termio flag is on. Calls to
221 * uart_shutdown are serialised by the per-port semaphore.
222 */
223static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
224{
225 struct uart_port *uport = state->uart_port;
226 struct tty_port *port = &state->port;
227
228 /*
229 * Set the TTY IO error marker
230 */
231 if (tty)
232 set_bit(TTY_IO_ERROR, &tty->flags);
233
234 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
235 /*
236 * Turn off DTR and RTS early.
237 */
238 if (uart_console(uport) && tty)
239 uport->cons->cflag = tty->termios.c_cflag;
240
241 if (!tty || C_HUPCL(tty))
242 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
243
244 uart_port_shutdown(port);
245 }
246
247 /*
248 * It's possible for shutdown to be called after suspend if we get
249 * a DCD drop (hangup) at just the right time. Clear suspended bit so
250 * we don't try to resume a port that has been shutdown.
251 */
252 clear_bit(ASYNCB_SUSPENDED, &port->flags);
253
254 /*
255 * Free the transmit buffer page.
256 */
257 if (state->xmit.buf) {
258 free_page((unsigned long)state->xmit.buf);
259 state->xmit.buf = NULL;
260 }
261}
262
263/**
264 * uart_update_timeout - update per-port FIFO timeout.
265 * @port: uart_port structure describing the port
266 * @cflag: termios cflag value
267 * @baud: speed of the port
268 *
269 * Set the port FIFO timeout value. The @cflag value should
270 * reflect the actual hardware settings.
271 */
272void
273uart_update_timeout(struct uart_port *port, unsigned int cflag,
274 unsigned int baud)
275{
276 unsigned int bits;
277
278 /* byte size and parity */
279 switch (cflag & CSIZE) {
280 case CS5:
281 bits = 7;
282 break;
283 case CS6:
284 bits = 8;
285 break;
286 case CS7:
287 bits = 9;
288 break;
289 default:
290 bits = 10;
291 break; /* CS8 */
292 }
293
294 if (cflag & CSTOPB)
295 bits++;
296 if (cflag & PARENB)
297 bits++;
298
299 /*
300 * The total number of bits to be transmitted in the fifo.
301 */
302 bits = bits * port->fifosize;
303
304 /*
305 * Figure the timeout to send the above number of bits.
306 * Add .02 seconds of slop
307 */
308 port->timeout = (HZ * bits) / baud + HZ/50;
309}
310
311EXPORT_SYMBOL(uart_update_timeout);
312
313/**
314 * uart_get_baud_rate - return baud rate for a particular port
315 * @port: uart_port structure describing the port in question.
316 * @termios: desired termios settings.
317 * @old: old termios (or NULL)
318 * @min: minimum acceptable baud rate
319 * @max: maximum acceptable baud rate
320 *
321 * Decode the termios structure into a numeric baud rate,
322 * taking account of the magic 38400 baud rate (with spd_*
323 * flags), and mapping the %B0 rate to 9600 baud.
324 *
325 * If the new baud rate is invalid, try the old termios setting.
326 * If it's still invalid, we try 9600 baud.
327 *
328 * Update the @termios structure to reflect the baud rate
329 * we're actually going to be using. Don't do this for the case
330 * where B0 is requested ("hang up").
331 */
332unsigned int
333uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
334 struct ktermios *old, unsigned int min, unsigned int max)
335{
336 unsigned int try;
337 unsigned int baud;
338 unsigned int altbaud;
339 int hung_up = 0;
340 upf_t flags = port->flags & UPF_SPD_MASK;
341
342 switch (flags) {
343 case UPF_SPD_HI:
344 altbaud = 57600;
345 break;
346 case UPF_SPD_VHI:
347 altbaud = 115200;
348 break;
349 case UPF_SPD_SHI:
350 altbaud = 230400;
351 break;
352 case UPF_SPD_WARP:
353 altbaud = 460800;
354 break;
355 default:
356 altbaud = 38400;
357 break;
358 }
359
360 for (try = 0; try < 2; try++) {
361 baud = tty_termios_baud_rate(termios);
362
363 /*
364 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
365 * Die! Die! Die!
366 */
367 if (try == 0 && baud == 38400)
368 baud = altbaud;
369
370 /*
371 * Special case: B0 rate.
372 */
373 if (baud == 0) {
374 hung_up = 1;
375 baud = 9600;
376 }
377
378 if (baud >= min && baud <= max)
379 return baud;
380
381 /*
382 * Oops, the quotient was zero. Try again with
383 * the old baud rate if possible.
384 */
385 termios->c_cflag &= ~CBAUD;
386 if (old) {
387 baud = tty_termios_baud_rate(old);
388 if (!hung_up)
389 tty_termios_encode_baud_rate(termios,
390 baud, baud);
391 old = NULL;
392 continue;
393 }
394
395 /*
396 * As a last resort, if the range cannot be met then clip to
397 * the nearest chip supported rate.
398 */
399 if (!hung_up) {
400 if (baud <= min)
401 tty_termios_encode_baud_rate(termios,
402 min + 1, min + 1);
403 else
404 tty_termios_encode_baud_rate(termios,
405 max - 1, max - 1);
406 }
407 }
408 /* Should never happen */
409 WARN_ON(1);
410 return 0;
411}
412
413EXPORT_SYMBOL(uart_get_baud_rate);
414
415/**
416 * uart_get_divisor - return uart clock divisor
417 * @port: uart_port structure describing the port.
418 * @baud: desired baud rate
419 *
420 * Calculate the uart clock divisor for the port.
421 */
422unsigned int
423uart_get_divisor(struct uart_port *port, unsigned int baud)
424{
425 unsigned int quot;
426
427 /*
428 * Old custom speed handling.
429 */
430 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
431 quot = port->custom_divisor;
432 else
433 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
434
435 return quot;
436}
437
438EXPORT_SYMBOL(uart_get_divisor);
439
440/* Caller holds port mutex */
441static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
442 struct ktermios *old_termios)
443{
444 struct uart_port *uport = state->uart_port;
445 struct ktermios *termios;
446 int hw_stopped;
447
448 /*
449 * If we have no tty, termios, or the port does not exist,
450 * then we can't set the parameters for this port.
451 */
452 if (!tty || uport->type == PORT_UNKNOWN)
453 return;
454
455 termios = &tty->termios;
456 uport->ops->set_termios(uport, termios, old_termios);
457
458 /*
459 * Set modem status enables based on termios cflag
460 */
461 spin_lock_irq(&uport->lock);
462 if (termios->c_cflag & CRTSCTS)
463 uport->status |= UPSTAT_CTS_ENABLE;
464 else
465 uport->status &= ~UPSTAT_CTS_ENABLE;
466
467 if (termios->c_cflag & CLOCAL)
468 uport->status &= ~UPSTAT_DCD_ENABLE;
469 else
470 uport->status |= UPSTAT_DCD_ENABLE;
471
472 /* reset sw-assisted CTS flow control based on (possibly) new mode */
473 hw_stopped = uport->hw_stopped;
474 uport->hw_stopped = uart_softcts_mode(uport) &&
475 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
476 if (uport->hw_stopped) {
477 if (!hw_stopped)
478 uport->ops->stop_tx(uport);
479 } else {
480 if (hw_stopped)
481 __uart_start(tty);
482 }
483 spin_unlock_irq(&uport->lock);
484}
485
486static int uart_put_char(struct tty_struct *tty, unsigned char c)
487{
488 struct uart_state *state = tty->driver_data;
489 struct uart_port *port = state->uart_port;
490 struct circ_buf *circ;
491 unsigned long flags;
492 int ret = 0;
493
494 circ = &state->xmit;
495 if (!circ->buf)
496 return 0;
497
498 spin_lock_irqsave(&port->lock, flags);
499 if (uart_circ_chars_free(circ) != 0) {
500 circ->buf[circ->head] = c;
501 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
502 ret = 1;
503 }
504 spin_unlock_irqrestore(&port->lock, flags);
505 return ret;
506}
507
508static void uart_flush_chars(struct tty_struct *tty)
509{
510 uart_start(tty);
511}
512
513static int uart_write(struct tty_struct *tty,
514 const unsigned char *buf, int count)
515{
516 struct uart_state *state = tty->driver_data;
517 struct uart_port *port;
518 struct circ_buf *circ;
519 unsigned long flags;
520 int c, ret = 0;
521
522 /*
523 * This means you called this function _after_ the port was
524 * closed. No cookie for you.
525 */
526 if (!state) {
527 WARN_ON(1);
528 return -EL3HLT;
529 }
530
531 port = state->uart_port;
532 circ = &state->xmit;
533
534 if (!circ->buf)
535 return 0;
536
537 spin_lock_irqsave(&port->lock, flags);
538 while (1) {
539 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
540 if (count < c)
541 c = count;
542 if (c <= 0)
543 break;
544 memcpy(circ->buf + circ->head, buf, c);
545 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
546 buf += c;
547 count -= c;
548 ret += c;
549 }
550
551 __uart_start(tty);
552 spin_unlock_irqrestore(&port->lock, flags);
553
554 return ret;
555}
556
557static int uart_write_room(struct tty_struct *tty)
558{
559 struct uart_state *state = tty->driver_data;
560 unsigned long flags;
561 int ret;
562
563 spin_lock_irqsave(&state->uart_port->lock, flags);
564 ret = uart_circ_chars_free(&state->xmit);
565 spin_unlock_irqrestore(&state->uart_port->lock, flags);
566 return ret;
567}
568
569static int uart_chars_in_buffer(struct tty_struct *tty)
570{
571 struct uart_state *state = tty->driver_data;
572 unsigned long flags;
573 int ret;
574
575 spin_lock_irqsave(&state->uart_port->lock, flags);
576 ret = uart_circ_chars_pending(&state->xmit);
577 spin_unlock_irqrestore(&state->uart_port->lock, flags);
578 return ret;
579}
580
581static void uart_flush_buffer(struct tty_struct *tty)
582{
583 struct uart_state *state = tty->driver_data;
584 struct uart_port *port;
585 unsigned long flags;
586
587 /*
588 * This means you called this function _after_ the port was
589 * closed. No cookie for you.
590 */
591 if (!state) {
592 WARN_ON(1);
593 return;
594 }
595
596 port = state->uart_port;
597 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
598
599 spin_lock_irqsave(&port->lock, flags);
600 uart_circ_clear(&state->xmit);
601 if (port->ops->flush_buffer)
602 port->ops->flush_buffer(port);
603 spin_unlock_irqrestore(&port->lock, flags);
604 tty_wakeup(tty);
605}
606
607/*
608 * This function is used to send a high-priority XON/XOFF character to
609 * the device
610 */
611static void uart_send_xchar(struct tty_struct *tty, char ch)
612{
613 struct uart_state *state = tty->driver_data;
614 struct uart_port *port = state->uart_port;
615 unsigned long flags;
616
617 if (port->ops->send_xchar)
618 port->ops->send_xchar(port, ch);
619 else {
620 spin_lock_irqsave(&port->lock, flags);
621 port->x_char = ch;
622 if (ch)
623 port->ops->start_tx(port);
624 spin_unlock_irqrestore(&port->lock, flags);
625 }
626}
627
628static void uart_throttle(struct tty_struct *tty)
629{
630 struct uart_state *state = tty->driver_data;
631 struct uart_port *port = state->uart_port;
632 upstat_t mask = 0;
633
634 if (I_IXOFF(tty))
635 mask |= UPSTAT_AUTOXOFF;
636 if (C_CRTSCTS(tty))
637 mask |= UPSTAT_AUTORTS;
638
639 if (port->status & mask) {
640 port->ops->throttle(port);
641 mask &= ~port->status;
642 }
643
644 if (mask & UPSTAT_AUTORTS)
645 uart_clear_mctrl(port, TIOCM_RTS);
646
647 if (mask & UPSTAT_AUTOXOFF)
648 uart_send_xchar(tty, STOP_CHAR(tty));
649}
650
651static void uart_unthrottle(struct tty_struct *tty)
652{
653 struct uart_state *state = tty->driver_data;
654 struct uart_port *port = state->uart_port;
655 upstat_t mask = 0;
656
657 if (I_IXOFF(tty))
658 mask |= UPSTAT_AUTOXOFF;
659 if (C_CRTSCTS(tty))
660 mask |= UPSTAT_AUTORTS;
661
662 if (port->status & mask) {
663 port->ops->unthrottle(port);
664 mask &= ~port->status;
665 }
666
667 if (mask & UPSTAT_AUTORTS)
668 uart_set_mctrl(port, TIOCM_RTS);
669
670 if (mask & UPSTAT_AUTOXOFF)
671 uart_send_xchar(tty, START_CHAR(tty));
672}
673
674static void uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
675{
676 struct uart_state *state = container_of(port, struct uart_state, port);
677 struct uart_port *uport = state->uart_port;
678
679 memset(retinfo, 0, sizeof(*retinfo));
680
681 /*
682 * Ensure the state we copy is consistent and no hardware changes
683 * occur as we go
684 */
685 mutex_lock(&port->mutex);
686 retinfo->type = uport->type;
687 retinfo->line = uport->line;
688 retinfo->port = uport->iobase;
689 if (HIGH_BITS_OFFSET)
690 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
691 retinfo->irq = uport->irq;
692 retinfo->flags = uport->flags;
693 retinfo->xmit_fifo_size = uport->fifosize;
694 retinfo->baud_base = uport->uartclk / 16;
695 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
696 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
697 ASYNC_CLOSING_WAIT_NONE :
698 jiffies_to_msecs(port->closing_wait) / 10;
699 retinfo->custom_divisor = uport->custom_divisor;
700 retinfo->hub6 = uport->hub6;
701 retinfo->io_type = uport->iotype;
702 retinfo->iomem_reg_shift = uport->regshift;
703 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
704 mutex_unlock(&port->mutex);
705}
706
707static int uart_get_info_user(struct tty_port *port,
708 struct serial_struct __user *retinfo)
709{
710 struct serial_struct tmp;
711
712 uart_get_info(port, &tmp);
713
714 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
715 return -EFAULT;
716 return 0;
717}
718
719static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
720 struct uart_state *state,
721 struct serial_struct *new_info)
722{
723 struct uart_port *uport = state->uart_port;
724 unsigned long new_port;
725 unsigned int change_irq, change_port, closing_wait;
726 unsigned int old_custom_divisor, close_delay;
727 upf_t old_flags, new_flags;
728 int retval = 0;
729
730 new_port = new_info->port;
731 if (HIGH_BITS_OFFSET)
732 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
733
734 new_info->irq = irq_canonicalize(new_info->irq);
735 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
736 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
737 ASYNC_CLOSING_WAIT_NONE :
738 msecs_to_jiffies(new_info->closing_wait * 10);
739
740
741 change_irq = !(uport->flags & UPF_FIXED_PORT)
742 && new_info->irq != uport->irq;
743
744 /*
745 * Since changing the 'type' of the port changes its resource
746 * allocations, we should treat type changes the same as
747 * IO port changes.
748 */
749 change_port = !(uport->flags & UPF_FIXED_PORT)
750 && (new_port != uport->iobase ||
751 (unsigned long)new_info->iomem_base != uport->mapbase ||
752 new_info->hub6 != uport->hub6 ||
753 new_info->io_type != uport->iotype ||
754 new_info->iomem_reg_shift != uport->regshift ||
755 new_info->type != uport->type);
756
757 old_flags = uport->flags;
758 new_flags = new_info->flags;
759 old_custom_divisor = uport->custom_divisor;
760
761 if (!capable(CAP_SYS_ADMIN)) {
762 retval = -EPERM;
763 if (change_irq || change_port ||
764 (new_info->baud_base != uport->uartclk / 16) ||
765 (close_delay != port->close_delay) ||
766 (closing_wait != port->closing_wait) ||
767 (new_info->xmit_fifo_size &&
768 new_info->xmit_fifo_size != uport->fifosize) ||
769 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
770 goto exit;
771 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
772 (new_flags & UPF_USR_MASK));
773 uport->custom_divisor = new_info->custom_divisor;
774 goto check_and_exit;
775 }
776
777 /*
778 * Ask the low level driver to verify the settings.
779 */
780 if (uport->ops->verify_port)
781 retval = uport->ops->verify_port(uport, new_info);
782
783 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
784 (new_info->baud_base < 9600))
785 retval = -EINVAL;
786
787 if (retval)
788 goto exit;
789
790 if (change_port || change_irq) {
791 retval = -EBUSY;
792
793 /*
794 * Make sure that we are the sole user of this port.
795 */
796 if (tty_port_users(port) > 1)
797 goto exit;
798
799 /*
800 * We need to shutdown the serial port at the old
801 * port/type/irq combination.
802 */
803 uart_shutdown(tty, state);
804 }
805
806 if (change_port) {
807 unsigned long old_iobase, old_mapbase;
808 unsigned int old_type, old_iotype, old_hub6, old_shift;
809
810 old_iobase = uport->iobase;
811 old_mapbase = uport->mapbase;
812 old_type = uport->type;
813 old_hub6 = uport->hub6;
814 old_iotype = uport->iotype;
815 old_shift = uport->regshift;
816
817 /*
818 * Free and release old regions
819 */
820 if (old_type != PORT_UNKNOWN)
821 uport->ops->release_port(uport);
822
823 uport->iobase = new_port;
824 uport->type = new_info->type;
825 uport->hub6 = new_info->hub6;
826 uport->iotype = new_info->io_type;
827 uport->regshift = new_info->iomem_reg_shift;
828 uport->mapbase = (unsigned long)new_info->iomem_base;
829
830 /*
831 * Claim and map the new regions
832 */
833 if (uport->type != PORT_UNKNOWN) {
834 retval = uport->ops->request_port(uport);
835 } else {
836 /* Always success - Jean II */
837 retval = 0;
838 }
839
840 /*
841 * If we fail to request resources for the
842 * new port, try to restore the old settings.
843 */
844 if (retval) {
845 uport->iobase = old_iobase;
846 uport->type = old_type;
847 uport->hub6 = old_hub6;
848 uport->iotype = old_iotype;
849 uport->regshift = old_shift;
850 uport->mapbase = old_mapbase;
851
852 if (old_type != PORT_UNKNOWN) {
853 retval = uport->ops->request_port(uport);
854 /*
855 * If we failed to restore the old settings,
856 * we fail like this.
857 */
858 if (retval)
859 uport->type = PORT_UNKNOWN;
860
861 /*
862 * We failed anyway.
863 */
864 retval = -EBUSY;
865 }
866
867 /* Added to return the correct error -Ram Gupta */
868 goto exit;
869 }
870 }
871
872 if (change_irq)
873 uport->irq = new_info->irq;
874 if (!(uport->flags & UPF_FIXED_PORT))
875 uport->uartclk = new_info->baud_base * 16;
876 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
877 (new_flags & UPF_CHANGE_MASK);
878 uport->custom_divisor = new_info->custom_divisor;
879 port->close_delay = close_delay;
880 port->closing_wait = closing_wait;
881 if (new_info->xmit_fifo_size)
882 uport->fifosize = new_info->xmit_fifo_size;
883 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
884
885 check_and_exit:
886 retval = 0;
887 if (uport->type == PORT_UNKNOWN)
888 goto exit;
889 if (port->flags & ASYNC_INITIALIZED) {
890 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
891 old_custom_divisor != uport->custom_divisor) {
892 /*
893 * If they're setting up a custom divisor or speed,
894 * instead of clearing it, then bitch about it. No
895 * need to rate-limit; it's CAP_SYS_ADMIN only.
896 */
897 if (uport->flags & UPF_SPD_MASK) {
898 dev_notice(uport->dev,
899 "%s sets custom speed on %s. This is deprecated.\n",
900 current->comm,
901 tty_name(port->tty));
902 }
903 uart_change_speed(tty, state, NULL);
904 }
905 } else
906 retval = uart_startup(tty, state, 1);
907 exit:
908 return retval;
909}
910
911static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
912 struct serial_struct __user *newinfo)
913{
914 struct serial_struct new_serial;
915 struct tty_port *port = &state->port;
916 int retval;
917
918 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
919 return -EFAULT;
920
921 /*
922 * This semaphore protects port->count. It is also
923 * very useful to prevent opens. Also, take the
924 * port configuration semaphore to make sure that a
925 * module insertion/removal doesn't change anything
926 * under us.
927 */
928 mutex_lock(&port->mutex);
929 retval = uart_set_info(tty, port, state, &new_serial);
930 mutex_unlock(&port->mutex);
931 return retval;
932}
933
934/**
935 * uart_get_lsr_info - get line status register info
936 * @tty: tty associated with the UART
937 * @state: UART being queried
938 * @value: returned modem value
939 *
940 * Note: uart_ioctl protects us against hangups.
941 */
942static int uart_get_lsr_info(struct tty_struct *tty,
943 struct uart_state *state, unsigned int __user *value)
944{
945 struct uart_port *uport = state->uart_port;
946 unsigned int result;
947
948 result = uport->ops->tx_empty(uport);
949
950 /*
951 * If we're about to load something into the transmit
952 * register, we'll pretend the transmitter isn't empty to
953 * avoid a race condition (depending on when the transmit
954 * interrupt happens).
955 */
956 if (uport->x_char ||
957 ((uart_circ_chars_pending(&state->xmit) > 0) &&
958 !uart_tx_stopped(uport)))
959 result &= ~TIOCSER_TEMT;
960
961 return put_user(result, value);
962}
963
964static int uart_tiocmget(struct tty_struct *tty)
965{
966 struct uart_state *state = tty->driver_data;
967 struct tty_port *port = &state->port;
968 struct uart_port *uport = state->uart_port;
969 int result = -EIO;
970
971 mutex_lock(&port->mutex);
972 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
973 result = uport->mctrl;
974 spin_lock_irq(&uport->lock);
975 result |= uport->ops->get_mctrl(uport);
976 spin_unlock_irq(&uport->lock);
977 }
978 mutex_unlock(&port->mutex);
979
980 return result;
981}
982
983static int
984uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
985{
986 struct uart_state *state = tty->driver_data;
987 struct uart_port *uport = state->uart_port;
988 struct tty_port *port = &state->port;
989 int ret = -EIO;
990
991 mutex_lock(&port->mutex);
992 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
993 uart_update_mctrl(uport, set, clear);
994 ret = 0;
995 }
996 mutex_unlock(&port->mutex);
997 return ret;
998}
999
1000static int uart_break_ctl(struct tty_struct *tty, int break_state)
1001{
1002 struct uart_state *state = tty->driver_data;
1003 struct tty_port *port = &state->port;
1004 struct uart_port *uport = state->uart_port;
1005
1006 mutex_lock(&port->mutex);
1007
1008 if (uport->type != PORT_UNKNOWN)
1009 uport->ops->break_ctl(uport, break_state);
1010
1011 mutex_unlock(&port->mutex);
1012 return 0;
1013}
1014
1015static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1016{
1017 struct uart_port *uport = state->uart_port;
1018 struct tty_port *port = &state->port;
1019 int flags, ret;
1020
1021 if (!capable(CAP_SYS_ADMIN))
1022 return -EPERM;
1023
1024 /*
1025 * Take the per-port semaphore. This prevents count from
1026 * changing, and hence any extra opens of the port while
1027 * we're auto-configuring.
1028 */
1029 if (mutex_lock_interruptible(&port->mutex))
1030 return -ERESTARTSYS;
1031
1032 ret = -EBUSY;
1033 if (tty_port_users(port) == 1) {
1034 uart_shutdown(tty, state);
1035
1036 /*
1037 * If we already have a port type configured,
1038 * we must release its resources.
1039 */
1040 if (uport->type != PORT_UNKNOWN)
1041 uport->ops->release_port(uport);
1042
1043 flags = UART_CONFIG_TYPE;
1044 if (uport->flags & UPF_AUTO_IRQ)
1045 flags |= UART_CONFIG_IRQ;
1046
1047 /*
1048 * This will claim the ports resources if
1049 * a port is found.
1050 */
1051 uport->ops->config_port(uport, flags);
1052
1053 ret = uart_startup(tty, state, 1);
1054 }
1055 mutex_unlock(&port->mutex);
1056 return ret;
1057}
1058
1059static void uart_enable_ms(struct uart_port *uport)
1060{
1061 /*
1062 * Force modem status interrupts on
1063 */
1064 if (uport->ops->enable_ms)
1065 uport->ops->enable_ms(uport);
1066}
1067
1068/*
1069 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1070 * - mask passed in arg for lines of interest
1071 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1072 * Caller should use TIOCGICOUNT to see which one it was
1073 *
1074 * FIXME: This wants extracting into a common all driver implementation
1075 * of TIOCMWAIT using tty_port.
1076 */
1077static int
1078uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1079{
1080 struct uart_port *uport = state->uart_port;
1081 struct tty_port *port = &state->port;
1082 DECLARE_WAITQUEUE(wait, current);
1083 struct uart_icount cprev, cnow;
1084 int ret;
1085
1086 /*
1087 * note the counters on entry
1088 */
1089 spin_lock_irq(&uport->lock);
1090 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1091 uart_enable_ms(uport);
1092 spin_unlock_irq(&uport->lock);
1093
1094 add_wait_queue(&port->delta_msr_wait, &wait);
1095 for (;;) {
1096 spin_lock_irq(&uport->lock);
1097 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1098 spin_unlock_irq(&uport->lock);
1099
1100 set_current_state(TASK_INTERRUPTIBLE);
1101
1102 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1103 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1104 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1105 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1106 ret = 0;
1107 break;
1108 }
1109
1110 schedule();
1111
1112 /* see if a signal did it */
1113 if (signal_pending(current)) {
1114 ret = -ERESTARTSYS;
1115 break;
1116 }
1117
1118 cprev = cnow;
1119 }
1120 __set_current_state(TASK_RUNNING);
1121 remove_wait_queue(&port->delta_msr_wait, &wait);
1122
1123 return ret;
1124}
1125
1126/*
1127 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1128 * Return: write counters to the user passed counter struct
1129 * NB: both 1->0 and 0->1 transitions are counted except for
1130 * RI where only 0->1 is counted.
1131 */
1132static int uart_get_icount(struct tty_struct *tty,
1133 struct serial_icounter_struct *icount)
1134{
1135 struct uart_state *state = tty->driver_data;
1136 struct uart_icount cnow;
1137 struct uart_port *uport = state->uart_port;
1138
1139 spin_lock_irq(&uport->lock);
1140 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1141 spin_unlock_irq(&uport->lock);
1142
1143 icount->cts = cnow.cts;
1144 icount->dsr = cnow.dsr;
1145 icount->rng = cnow.rng;
1146 icount->dcd = cnow.dcd;
1147 icount->rx = cnow.rx;
1148 icount->tx = cnow.tx;
1149 icount->frame = cnow.frame;
1150 icount->overrun = cnow.overrun;
1151 icount->parity = cnow.parity;
1152 icount->brk = cnow.brk;
1153 icount->buf_overrun = cnow.buf_overrun;
1154
1155 return 0;
1156}
1157
1158static int uart_get_rs485_config(struct uart_port *port,
1159 struct serial_rs485 __user *rs485)
1160{
1161 unsigned long flags;
1162 struct serial_rs485 aux;
1163
1164 spin_lock_irqsave(&port->lock, flags);
1165 aux = port->rs485;
1166 spin_unlock_irqrestore(&port->lock, flags);
1167
1168 if (copy_to_user(rs485, &aux, sizeof(aux)))
1169 return -EFAULT;
1170
1171 return 0;
1172}
1173
1174static int uart_set_rs485_config(struct uart_port *port,
1175 struct serial_rs485 __user *rs485_user)
1176{
1177 struct serial_rs485 rs485;
1178 int ret;
1179 unsigned long flags;
1180
1181 if (!port->rs485_config)
1182 return -ENOIOCTLCMD;
1183
1184 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1185 return -EFAULT;
1186
1187 spin_lock_irqsave(&port->lock, flags);
1188 ret = port->rs485_config(port, &rs485);
1189 spin_unlock_irqrestore(&port->lock, flags);
1190 if (ret)
1191 return ret;
1192
1193 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1194 return -EFAULT;
1195
1196 return 0;
1197}
1198
1199/*
1200 * Called via sys_ioctl. We can use spin_lock_irq() here.
1201 */
1202static int
1203uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1204 unsigned long arg)
1205{
1206 struct uart_state *state = tty->driver_data;
1207 struct tty_port *port = &state->port;
1208 void __user *uarg = (void __user *)arg;
1209 int ret = -ENOIOCTLCMD;
1210
1211
1212 /*
1213 * These ioctls don't rely on the hardware to be present.
1214 */
1215 switch (cmd) {
1216 case TIOCGSERIAL:
1217 ret = uart_get_info_user(port, uarg);
1218 break;
1219
1220 case TIOCSSERIAL:
1221 down_write(&tty->termios_rwsem);
1222 ret = uart_set_info_user(tty, state, uarg);
1223 up_write(&tty->termios_rwsem);
1224 break;
1225
1226 case TIOCSERCONFIG:
1227 down_write(&tty->termios_rwsem);
1228 ret = uart_do_autoconfig(tty, state);
1229 up_write(&tty->termios_rwsem);
1230 break;
1231
1232 case TIOCSERGWILD: /* obsolete */
1233 case TIOCSERSWILD: /* obsolete */
1234 ret = 0;
1235 break;
1236 }
1237
1238 if (ret != -ENOIOCTLCMD)
1239 goto out;
1240
1241 if (tty->flags & (1 << TTY_IO_ERROR)) {
1242 ret = -EIO;
1243 goto out;
1244 }
1245
1246 /*
1247 * The following should only be used when hardware is present.
1248 */
1249 switch (cmd) {
1250 case TIOCMIWAIT:
1251 ret = uart_wait_modem_status(state, arg);
1252 break;
1253 }
1254
1255 if (ret != -ENOIOCTLCMD)
1256 goto out;
1257
1258 mutex_lock(&port->mutex);
1259
1260 if (tty->flags & (1 << TTY_IO_ERROR)) {
1261 ret = -EIO;
1262 goto out_up;
1263 }
1264
1265 /*
1266 * All these rely on hardware being present and need to be
1267 * protected against the tty being hung up.
1268 */
1269
1270 switch (cmd) {
1271 case TIOCSERGETLSR: /* Get line status register */
1272 ret = uart_get_lsr_info(tty, state, uarg);
1273 break;
1274
1275 case TIOCGRS485:
1276 ret = uart_get_rs485_config(state->uart_port, uarg);
1277 break;
1278
1279 case TIOCSRS485:
1280 ret = uart_set_rs485_config(state->uart_port, uarg);
1281 break;
1282 default: {
1283 struct uart_port *uport = state->uart_port;
1284 if (uport->ops->ioctl)
1285 ret = uport->ops->ioctl(uport, cmd, arg);
1286 break;
1287 }
1288 }
1289out_up:
1290 mutex_unlock(&port->mutex);
1291out:
1292 return ret;
1293}
1294
1295static void uart_set_ldisc(struct tty_struct *tty)
1296{
1297 struct uart_state *state = tty->driver_data;
1298 struct uart_port *uport = state->uart_port;
1299
1300 if (uport->ops->set_ldisc) {
1301 mutex_lock(&state->port.mutex);
1302 uport->ops->set_ldisc(uport, &tty->termios);
1303 mutex_unlock(&state->port.mutex);
1304 }
1305}
1306
1307static void uart_set_termios(struct tty_struct *tty,
1308 struct ktermios *old_termios)
1309{
1310 struct uart_state *state = tty->driver_data;
1311 struct uart_port *uport = state->uart_port;
1312 unsigned int cflag = tty->termios.c_cflag;
1313 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1314 bool sw_changed = false;
1315
1316 /*
1317 * Drivers doing software flow control also need to know
1318 * about changes to these input settings.
1319 */
1320 if (uport->flags & UPF_SOFT_FLOW) {
1321 iflag_mask |= IXANY|IXON|IXOFF;
1322 sw_changed =
1323 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1324 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1325 }
1326
1327 /*
1328 * These are the bits that are used to setup various
1329 * flags in the low level driver. We can ignore the Bfoo
1330 * bits in c_cflag; c_[io]speed will always be set
1331 * appropriately by set_termios() in tty_ioctl.c
1332 */
1333 if ((cflag ^ old_termios->c_cflag) == 0 &&
1334 tty->termios.c_ospeed == old_termios->c_ospeed &&
1335 tty->termios.c_ispeed == old_termios->c_ispeed &&
1336 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1337 !sw_changed) {
1338 return;
1339 }
1340
1341 mutex_lock(&state->port.mutex);
1342 uart_change_speed(tty, state, old_termios);
1343 mutex_unlock(&state->port.mutex);
1344 /* reload cflag from termios; port driver may have overriden flags */
1345 cflag = tty->termios.c_cflag;
1346
1347 /* Handle transition to B0 status */
1348 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1349 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1350 /* Handle transition away from B0 status */
1351 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1352 unsigned int mask = TIOCM_DTR;
1353 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
1354 mask |= TIOCM_RTS;
1355 uart_set_mctrl(uport, mask);
1356 }
1357}
1358
1359/*
1360 * Calls to uart_close() are serialised via the tty_lock in
1361 * drivers/tty/tty_io.c:tty_release()
1362 * drivers/tty/tty_io.c:do_tty_hangup()
1363 * This runs from a workqueue and can sleep for a _short_ time only.
1364 */
1365static void uart_close(struct tty_struct *tty, struct file *filp)
1366{
1367 struct uart_state *state = tty->driver_data;
1368 struct tty_port *port;
1369 struct uart_port *uport;
1370
1371 if (!state) {
1372 struct uart_driver *drv = tty->driver->driver_state;
1373
1374 state = drv->state + tty->index;
1375 port = &state->port;
1376 spin_lock_irq(&port->lock);
1377 --port->count;
1378 spin_unlock_irq(&port->lock);
1379 return;
1380 }
1381
1382 uport = state->uart_port;
1383 port = &state->port;
1384 pr_debug("uart_close(%d) called\n", tty->index);
1385
1386 if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1387 return;
1388
1389 /*
1390 * At this point, we stop accepting input. To do this, we
1391 * disable the receive line status interrupts.
1392 */
1393 if (port->flags & ASYNC_INITIALIZED) {
1394 spin_lock_irq(&uport->lock);
1395 uport->ops->stop_rx(uport);
1396 spin_unlock_irq(&uport->lock);
1397 /*
1398 * Before we drop DTR, make sure the UART transmitter
1399 * has completely drained; this is especially
1400 * important if there is a transmit FIFO!
1401 */
1402 uart_wait_until_sent(tty, uport->timeout);
1403 }
1404
1405 mutex_lock(&port->mutex);
1406 uart_shutdown(tty, state);
1407 tty_port_tty_set(port, NULL);
1408
1409 spin_lock_irq(&port->lock);
1410
1411 if (port->blocked_open) {
1412 spin_unlock_irq(&port->lock);
1413 if (port->close_delay)
1414 msleep_interruptible(jiffies_to_msecs(port->close_delay));
1415 spin_lock_irq(&port->lock);
1416 } else if (!uart_console(uport)) {
1417 spin_unlock_irq(&port->lock);
1418 uart_change_pm(state, UART_PM_STATE_OFF);
1419 spin_lock_irq(&port->lock);
1420 }
1421
1422 /*
1423 * Wake up anyone trying to open this port.
1424 */
1425 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1426 spin_unlock_irq(&port->lock);
1427 wake_up_interruptible(&port->open_wait);
1428
1429 mutex_unlock(&port->mutex);
1430
1431 tty_ldisc_flush(tty);
1432 tty->closing = 0;
1433}
1434
1435static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1436{
1437 struct uart_state *state = tty->driver_data;
1438 struct uart_port *port = state->uart_port;
1439 unsigned long char_time, expire;
1440
1441 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1442 return;
1443
1444 /*
1445 * Set the check interval to be 1/5 of the estimated time to
1446 * send a single character, and make it at least 1. The check
1447 * interval should also be less than the timeout.
1448 *
1449 * Note: we have to use pretty tight timings here to satisfy
1450 * the NIST-PCTS.
1451 */
1452 char_time = (port->timeout - HZ/50) / port->fifosize;
1453 char_time = char_time / 5;
1454 if (char_time == 0)
1455 char_time = 1;
1456 if (timeout && timeout < char_time)
1457 char_time = timeout;
1458
1459 /*
1460 * If the transmitter hasn't cleared in twice the approximate
1461 * amount of time to send the entire FIFO, it probably won't
1462 * ever clear. This assumes the UART isn't doing flow
1463 * control, which is currently the case. Hence, if it ever
1464 * takes longer than port->timeout, this is probably due to a
1465 * UART bug of some kind. So, we clamp the timeout parameter at
1466 * 2*port->timeout.
1467 */
1468 if (timeout == 0 || timeout > 2 * port->timeout)
1469 timeout = 2 * port->timeout;
1470
1471 expire = jiffies + timeout;
1472
1473 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1474 port->line, jiffies, expire);
1475
1476 /*
1477 * Check whether the transmitter is empty every 'char_time'.
1478 * 'timeout' / 'expire' give us the maximum amount of time
1479 * we wait.
1480 */
1481 while (!port->ops->tx_empty(port)) {
1482 msleep_interruptible(jiffies_to_msecs(char_time));
1483 if (signal_pending(current))
1484 break;
1485 if (time_after(jiffies, expire))
1486 break;
1487 }
1488}
1489
1490/*
1491 * Calls to uart_hangup() are serialised by the tty_lock in
1492 * drivers/tty/tty_io.c:do_tty_hangup()
1493 * This runs from a workqueue and can sleep for a _short_ time only.
1494 */
1495static void uart_hangup(struct tty_struct *tty)
1496{
1497 struct uart_state *state = tty->driver_data;
1498 struct tty_port *port = &state->port;
1499 unsigned long flags;
1500
1501 pr_debug("uart_hangup(%d)\n", tty->index);
1502
1503 mutex_lock(&port->mutex);
1504 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1505 uart_flush_buffer(tty);
1506 uart_shutdown(tty, state);
1507 spin_lock_irqsave(&port->lock, flags);
1508 port->count = 0;
1509 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1510 spin_unlock_irqrestore(&port->lock, flags);
1511 tty_port_tty_set(port, NULL);
1512 if (!uart_console(state->uart_port))
1513 uart_change_pm(state, UART_PM_STATE_OFF);
1514 wake_up_interruptible(&port->open_wait);
1515 wake_up_interruptible(&port->delta_msr_wait);
1516 }
1517 mutex_unlock(&port->mutex);
1518}
1519
1520static void uart_port_shutdown(struct tty_port *port)
1521{
1522 struct uart_state *state = container_of(port, struct uart_state, port);
1523 struct uart_port *uport = state->uart_port;
1524
1525 /*
1526 * clear delta_msr_wait queue to avoid mem leaks: we may free
1527 * the irq here so the queue might never be woken up. Note
1528 * that we won't end up waiting on delta_msr_wait again since
1529 * any outstanding file descriptors should be pointing at
1530 * hung_up_tty_fops now.
1531 */
1532 wake_up_interruptible(&port->delta_msr_wait);
1533
1534 /*
1535 * Free the IRQ and disable the port.
1536 */
1537 uport->ops->shutdown(uport);
1538
1539 /*
1540 * Ensure that the IRQ handler isn't running on another CPU.
1541 */
1542 synchronize_irq(uport->irq);
1543}
1544
1545static int uart_carrier_raised(struct tty_port *port)
1546{
1547 struct uart_state *state = container_of(port, struct uart_state, port);
1548 struct uart_port *uport = state->uart_port;
1549 int mctrl;
1550 spin_lock_irq(&uport->lock);
1551 uart_enable_ms(uport);
1552 mctrl = uport->ops->get_mctrl(uport);
1553 spin_unlock_irq(&uport->lock);
1554 if (mctrl & TIOCM_CAR)
1555 return 1;
1556 return 0;
1557}
1558
1559static void uart_dtr_rts(struct tty_port *port, int onoff)
1560{
1561 struct uart_state *state = container_of(port, struct uart_state, port);
1562 struct uart_port *uport = state->uart_port;
1563
1564 if (onoff)
1565 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1566 else
1567 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1568}
1569
1570/*
1571 * Calls to uart_open are serialised by the tty_lock in
1572 * drivers/tty/tty_io.c:tty_open()
1573 * Note that if this fails, then uart_close() _will_ be called.
1574 *
1575 * In time, we want to scrap the "opening nonpresent ports"
1576 * behaviour and implement an alternative way for setserial
1577 * to set base addresses/ports/types. This will allow us to
1578 * get rid of a certain amount of extra tests.
1579 */
1580static int uart_open(struct tty_struct *tty, struct file *filp)
1581{
1582 struct uart_driver *drv = tty->driver->driver_state;
1583 int retval, line = tty->index;
1584 struct uart_state *state = drv->state + line;
1585 struct tty_port *port = &state->port;
1586
1587 pr_debug("uart_open(%d) called\n", line);
1588
1589 spin_lock_irq(&port->lock);
1590 ++port->count;
1591 spin_unlock_irq(&port->lock);
1592
1593 /*
1594 * We take the semaphore here to guarantee that we won't be re-entered
1595 * while allocating the state structure, or while we request any IRQs
1596 * that the driver may need. This also has the nice side-effect that
1597 * it delays the action of uart_hangup, so we can guarantee that
1598 * state->port.tty will always contain something reasonable.
1599 */
1600 if (mutex_lock_interruptible(&port->mutex)) {
1601 retval = -ERESTARTSYS;
1602 goto end;
1603 }
1604
1605 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1606 retval = -ENXIO;
1607 goto err_unlock;
1608 }
1609
1610 tty->driver_data = state;
1611 state->uart_port->state = state;
1612 state->port.low_latency =
1613 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1614 tty_port_tty_set(port, tty);
1615
1616 /*
1617 * Start up the serial port.
1618 */
1619 retval = uart_startup(tty, state, 0);
1620
1621 /*
1622 * If we succeeded, wait until the port is ready.
1623 */
1624err_unlock:
1625 mutex_unlock(&port->mutex);
1626 if (retval == 0)
1627 retval = tty_port_block_til_ready(port, tty, filp);
1628end:
1629 return retval;
1630}
1631
1632static const char *uart_type(struct uart_port *port)
1633{
1634 const char *str = NULL;
1635
1636 if (port->ops->type)
1637 str = port->ops->type(port);
1638
1639 if (!str)
1640 str = "unknown";
1641
1642 return str;
1643}
1644
1645#ifdef CONFIG_PROC_FS
1646
1647static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1648{
1649 struct uart_state *state = drv->state + i;
1650 struct tty_port *port = &state->port;
1651 enum uart_pm_state pm_state;
1652 struct uart_port *uport = state->uart_port;
1653 char stat_buf[32];
1654 unsigned int status;
1655 int mmio;
1656
1657 if (!uport)
1658 return;
1659
1660 mmio = uport->iotype >= UPIO_MEM;
1661 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1662 uport->line, uart_type(uport),
1663 mmio ? "mmio:0x" : "port:",
1664 mmio ? (unsigned long long)uport->mapbase
1665 : (unsigned long long)uport->iobase,
1666 uport->irq);
1667
1668 if (uport->type == PORT_UNKNOWN) {
1669 seq_putc(m, '\n');
1670 return;
1671 }
1672
1673 if (capable(CAP_SYS_ADMIN)) {
1674 mutex_lock(&port->mutex);
1675 pm_state = state->pm_state;
1676 if (pm_state != UART_PM_STATE_ON)
1677 uart_change_pm(state, UART_PM_STATE_ON);
1678 spin_lock_irq(&uport->lock);
1679 status = uport->ops->get_mctrl(uport);
1680 spin_unlock_irq(&uport->lock);
1681 if (pm_state != UART_PM_STATE_ON)
1682 uart_change_pm(state, pm_state);
1683 mutex_unlock(&port->mutex);
1684
1685 seq_printf(m, " tx:%d rx:%d",
1686 uport->icount.tx, uport->icount.rx);
1687 if (uport->icount.frame)
1688 seq_printf(m, " fe:%d", uport->icount.frame);
1689 if (uport->icount.parity)
1690 seq_printf(m, " pe:%d", uport->icount.parity);
1691 if (uport->icount.brk)
1692 seq_printf(m, " brk:%d", uport->icount.brk);
1693 if (uport->icount.overrun)
1694 seq_printf(m, " oe:%d", uport->icount.overrun);
1695
1696#define INFOBIT(bit, str) \
1697 if (uport->mctrl & (bit)) \
1698 strncat(stat_buf, (str), sizeof(stat_buf) - \
1699 strlen(stat_buf) - 2)
1700#define STATBIT(bit, str) \
1701 if (status & (bit)) \
1702 strncat(stat_buf, (str), sizeof(stat_buf) - \
1703 strlen(stat_buf) - 2)
1704
1705 stat_buf[0] = '\0';
1706 stat_buf[1] = '\0';
1707 INFOBIT(TIOCM_RTS, "|RTS");
1708 STATBIT(TIOCM_CTS, "|CTS");
1709 INFOBIT(TIOCM_DTR, "|DTR");
1710 STATBIT(TIOCM_DSR, "|DSR");
1711 STATBIT(TIOCM_CAR, "|CD");
1712 STATBIT(TIOCM_RNG, "|RI");
1713 if (stat_buf[0])
1714 stat_buf[0] = ' ';
1715
1716 seq_puts(m, stat_buf);
1717 }
1718 seq_putc(m, '\n');
1719#undef STATBIT
1720#undef INFOBIT
1721}
1722
1723static int uart_proc_show(struct seq_file *m, void *v)
1724{
1725 struct tty_driver *ttydrv = m->private;
1726 struct uart_driver *drv = ttydrv->driver_state;
1727 int i;
1728
1729 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
1730 for (i = 0; i < drv->nr; i++)
1731 uart_line_info(m, drv, i);
1732 return 0;
1733}
1734
1735static int uart_proc_open(struct inode *inode, struct file *file)
1736{
1737 return single_open(file, uart_proc_show, PDE_DATA(inode));
1738}
1739
1740static const struct file_operations uart_proc_fops = {
1741 .owner = THIS_MODULE,
1742 .open = uart_proc_open,
1743 .read = seq_read,
1744 .llseek = seq_lseek,
1745 .release = single_release,
1746};
1747#endif
1748
1749#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1750/**
1751 * uart_console_write - write a console message to a serial port
1752 * @port: the port to write the message
1753 * @s: array of characters
1754 * @count: number of characters in string to write
1755 * @putchar: function to write character to port
1756 */
1757void uart_console_write(struct uart_port *port, const char *s,
1758 unsigned int count,
1759 void (*putchar)(struct uart_port *, int))
1760{
1761 unsigned int i;
1762
1763 for (i = 0; i < count; i++, s++) {
1764 if (*s == '\n')
1765 putchar(port, '\r');
1766 putchar(port, *s);
1767 }
1768}
1769EXPORT_SYMBOL_GPL(uart_console_write);
1770
1771/*
1772 * Check whether an invalid uart number has been specified, and
1773 * if so, search for the first available port that does have
1774 * console support.
1775 */
1776struct uart_port * __init
1777uart_get_console(struct uart_port *ports, int nr, struct console *co)
1778{
1779 int idx = co->index;
1780
1781 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1782 ports[idx].membase == NULL))
1783 for (idx = 0; idx < nr; idx++)
1784 if (ports[idx].iobase != 0 ||
1785 ports[idx].membase != NULL)
1786 break;
1787
1788 co->index = idx;
1789
1790 return ports + idx;
1791}
1792
1793/**
1794 * uart_parse_earlycon - Parse earlycon options
1795 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1796 * @iotype: ptr for decoded iotype (out)
1797 * @addr: ptr for decoded mapbase/iobase (out)
1798 * @options: ptr for <options> field; NULL if not present (out)
1799 *
1800 * Decodes earlycon kernel command line parameters of the form
1801 * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1802 * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1803 *
1804 * The optional form
1805 * earlycon=<name>,0x<addr>,<options>
1806 * console=<name>,0x<addr>,<options>
1807 * is also accepted; the returned @iotype will be UPIO_MEM.
1808 *
1809 * Returns 0 on success or -EINVAL on failure
1810 */
1811int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
1812 char **options)
1813{
1814 if (strncmp(p, "mmio,", 5) == 0) {
1815 *iotype = UPIO_MEM;
1816 p += 5;
1817 } else if (strncmp(p, "mmio16,", 7) == 0) {
1818 *iotype = UPIO_MEM16;
1819 p += 7;
1820 } else if (strncmp(p, "mmio32,", 7) == 0) {
1821 *iotype = UPIO_MEM32;
1822 p += 7;
1823 } else if (strncmp(p, "mmio32be,", 9) == 0) {
1824 *iotype = UPIO_MEM32BE;
1825 p += 9;
1826 } else if (strncmp(p, "mmio32native,", 13) == 0) {
1827 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
1828 UPIO_MEM32BE : UPIO_MEM32;
1829 p += 13;
1830 } else if (strncmp(p, "io,", 3) == 0) {
1831 *iotype = UPIO_PORT;
1832 p += 3;
1833 } else if (strncmp(p, "0x", 2) == 0) {
1834 *iotype = UPIO_MEM;
1835 } else {
1836 return -EINVAL;
1837 }
1838
1839 *addr = simple_strtoul(p, NULL, 0);
1840 p = strchr(p, ',');
1841 if (p)
1842 p++;
1843
1844 *options = p;
1845 return 0;
1846}
1847EXPORT_SYMBOL_GPL(uart_parse_earlycon);
1848
1849/**
1850 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1851 * @options: pointer to option string
1852 * @baud: pointer to an 'int' variable for the baud rate.
1853 * @parity: pointer to an 'int' variable for the parity.
1854 * @bits: pointer to an 'int' variable for the number of data bits.
1855 * @flow: pointer to an 'int' variable for the flow control character.
1856 *
1857 * uart_parse_options decodes a string containing the serial console
1858 * options. The format of the string is <baud><parity><bits><flow>,
1859 * eg: 115200n8r
1860 */
1861void
1862uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1863{
1864 char *s = options;
1865
1866 *baud = simple_strtoul(s, NULL, 10);
1867 while (*s >= '0' && *s <= '9')
1868 s++;
1869 if (*s)
1870 *parity = *s++;
1871 if (*s)
1872 *bits = *s++ - '0';
1873 if (*s)
1874 *flow = *s;
1875}
1876EXPORT_SYMBOL_GPL(uart_parse_options);
1877
1878/**
1879 * uart_set_options - setup the serial console parameters
1880 * @port: pointer to the serial ports uart_port structure
1881 * @co: console pointer
1882 * @baud: baud rate
1883 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1884 * @bits: number of data bits
1885 * @flow: flow control character - 'r' (rts)
1886 */
1887int
1888uart_set_options(struct uart_port *port, struct console *co,
1889 int baud, int parity, int bits, int flow)
1890{
1891 struct ktermios termios;
1892 static struct ktermios dummy;
1893
1894 /*
1895 * Ensure that the serial console lock is initialised
1896 * early.
1897 * If this port is a console, then the spinlock is already
1898 * initialised.
1899 */
1900 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1901 spin_lock_init(&port->lock);
1902 lockdep_set_class(&port->lock, &port_lock_key);
1903 }
1904
1905 memset(&termios, 0, sizeof(struct ktermios));
1906
1907 termios.c_cflag |= CREAD | HUPCL | CLOCAL;
1908 tty_termios_encode_baud_rate(&termios, baud, baud);
1909
1910 if (bits == 7)
1911 termios.c_cflag |= CS7;
1912 else
1913 termios.c_cflag |= CS8;
1914
1915 switch (parity) {
1916 case 'o': case 'O':
1917 termios.c_cflag |= PARODD;
1918 /*fall through*/
1919 case 'e': case 'E':
1920 termios.c_cflag |= PARENB;
1921 break;
1922 }
1923
1924 if (flow == 'r')
1925 termios.c_cflag |= CRTSCTS;
1926
1927 /*
1928 * some uarts on other side don't support no flow control.
1929 * So we set * DTR in host uart to make them happy
1930 */
1931 port->mctrl |= TIOCM_DTR;
1932
1933 port->ops->set_termios(port, &termios, &dummy);
1934 /*
1935 * Allow the setting of the UART parameters with a NULL console
1936 * too:
1937 */
1938 if (co)
1939 co->cflag = termios.c_cflag;
1940
1941 return 0;
1942}
1943EXPORT_SYMBOL_GPL(uart_set_options);
1944#endif /* CONFIG_SERIAL_CORE_CONSOLE */
1945
1946/**
1947 * uart_change_pm - set power state of the port
1948 *
1949 * @state: port descriptor
1950 * @pm_state: new state
1951 *
1952 * Locking: port->mutex has to be held
1953 */
1954static void uart_change_pm(struct uart_state *state,
1955 enum uart_pm_state pm_state)
1956{
1957 struct uart_port *port = state->uart_port;
1958
1959 if (state->pm_state != pm_state) {
1960 if (port->ops->pm)
1961 port->ops->pm(port, pm_state, state->pm_state);
1962 state->pm_state = pm_state;
1963 }
1964}
1965
1966struct uart_match {
1967 struct uart_port *port;
1968 struct uart_driver *driver;
1969};
1970
1971static int serial_match_port(struct device *dev, void *data)
1972{
1973 struct uart_match *match = data;
1974 struct tty_driver *tty_drv = match->driver->tty_driver;
1975 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1976 match->port->line;
1977
1978 return dev->devt == devt; /* Actually, only one tty per port */
1979}
1980
1981int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1982{
1983 struct uart_state *state = drv->state + uport->line;
1984 struct tty_port *port = &state->port;
1985 struct device *tty_dev;
1986 struct uart_match match = {uport, drv};
1987
1988 mutex_lock(&port->mutex);
1989
1990 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1991 if (device_may_wakeup(tty_dev)) {
1992 if (!enable_irq_wake(uport->irq))
1993 uport->irq_wake = 1;
1994 put_device(tty_dev);
1995 mutex_unlock(&port->mutex);
1996 return 0;
1997 }
1998 put_device(tty_dev);
1999
2000 /* Nothing to do if the console is not suspending */
2001 if (!console_suspend_enabled && uart_console(uport))
2002 goto unlock;
2003
2004 uport->suspended = 1;
2005
2006 if (port->flags & ASYNC_INITIALIZED) {
2007 const struct uart_ops *ops = uport->ops;
2008 int tries;
2009
2010 set_bit(ASYNCB_SUSPENDED, &port->flags);
2011 clear_bit(ASYNCB_INITIALIZED, &port->flags);
2012
2013 spin_lock_irq(&uport->lock);
2014 ops->stop_tx(uport);
2015 ops->set_mctrl(uport, 0);
2016 ops->stop_rx(uport);
2017 spin_unlock_irq(&uport->lock);
2018
2019 /*
2020 * Wait for the transmitter to empty.
2021 */
2022 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2023 msleep(10);
2024 if (!tries)
2025 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
2026 drv->dev_name,
2027 drv->tty_driver->name_base + uport->line);
2028
2029 ops->shutdown(uport);
2030 }
2031
2032 /*
2033 * Disable the console device before suspending.
2034 */
2035 if (uart_console(uport))
2036 console_stop(uport->cons);
2037
2038 uart_change_pm(state, UART_PM_STATE_OFF);
2039unlock:
2040 mutex_unlock(&port->mutex);
2041
2042 return 0;
2043}
2044
2045int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2046{
2047 struct uart_state *state = drv->state + uport->line;
2048 struct tty_port *port = &state->port;
2049 struct device *tty_dev;
2050 struct uart_match match = {uport, drv};
2051 struct ktermios termios;
2052
2053 mutex_lock(&port->mutex);
2054
2055 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2056 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2057 if (uport->irq_wake) {
2058 disable_irq_wake(uport->irq);
2059 uport->irq_wake = 0;
2060 }
2061 put_device(tty_dev);
2062 mutex_unlock(&port->mutex);
2063 return 0;
2064 }
2065 put_device(tty_dev);
2066 uport->suspended = 0;
2067
2068 /*
2069 * Re-enable the console device after suspending.
2070 */
2071 if (uart_console(uport)) {
2072 /*
2073 * First try to use the console cflag setting.
2074 */
2075 memset(&termios, 0, sizeof(struct ktermios));
2076 termios.c_cflag = uport->cons->cflag;
2077
2078 /*
2079 * If that's unset, use the tty termios setting.
2080 */
2081 if (port->tty && termios.c_cflag == 0)
2082 termios = port->tty->termios;
2083
2084 if (console_suspend_enabled)
2085 uart_change_pm(state, UART_PM_STATE_ON);
2086 uport->ops->set_termios(uport, &termios, NULL);
2087 if (console_suspend_enabled)
2088 console_start(uport->cons);
2089 }
2090
2091 if (port->flags & ASYNC_SUSPENDED) {
2092 const struct uart_ops *ops = uport->ops;
2093 int ret;
2094
2095 uart_change_pm(state, UART_PM_STATE_ON);
2096 spin_lock_irq(&uport->lock);
2097 ops->set_mctrl(uport, 0);
2098 spin_unlock_irq(&uport->lock);
2099 if (console_suspend_enabled || !uart_console(uport)) {
2100 /* Protected by port mutex for now */
2101 struct tty_struct *tty = port->tty;
2102 ret = ops->startup(uport);
2103 if (ret == 0) {
2104 if (tty)
2105 uart_change_speed(tty, state, NULL);
2106 spin_lock_irq(&uport->lock);
2107 ops->set_mctrl(uport, uport->mctrl);
2108 ops->start_tx(uport);
2109 spin_unlock_irq(&uport->lock);
2110 set_bit(ASYNCB_INITIALIZED, &port->flags);
2111 } else {
2112 /*
2113 * Failed to resume - maybe hardware went away?
2114 * Clear the "initialized" flag so we won't try
2115 * to call the low level drivers shutdown method.
2116 */
2117 uart_shutdown(tty, state);
2118 }
2119 }
2120
2121 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2122 }
2123
2124 mutex_unlock(&port->mutex);
2125
2126 return 0;
2127}
2128
2129static inline void
2130uart_report_port(struct uart_driver *drv, struct uart_port *port)
2131{
2132 char address[64];
2133
2134 switch (port->iotype) {
2135 case UPIO_PORT:
2136 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2137 break;
2138 case UPIO_HUB6:
2139 snprintf(address, sizeof(address),
2140 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2141 break;
2142 case UPIO_MEM:
2143 case UPIO_MEM16:
2144 case UPIO_MEM32:
2145 case UPIO_MEM32BE:
2146 case UPIO_AU:
2147 case UPIO_TSI:
2148 snprintf(address, sizeof(address),
2149 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2150 break;
2151 default:
2152 strlcpy(address, "*unknown*", sizeof(address));
2153 break;
2154 }
2155
2156 printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2157 port->dev ? dev_name(port->dev) : "",
2158 port->dev ? ": " : "",
2159 drv->dev_name,
2160 drv->tty_driver->name_base + port->line,
2161 address, port->irq, port->uartclk / 16, uart_type(port));
2162}
2163
2164static void
2165uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2166 struct uart_port *port)
2167{
2168 unsigned int flags;
2169
2170 /*
2171 * If there isn't a port here, don't do anything further.
2172 */
2173 if (!port->iobase && !port->mapbase && !port->membase)
2174 return;
2175
2176 /*
2177 * Now do the auto configuration stuff. Note that config_port
2178 * is expected to claim the resources and map the port for us.
2179 */
2180 flags = 0;
2181 if (port->flags & UPF_AUTO_IRQ)
2182 flags |= UART_CONFIG_IRQ;
2183 if (port->flags & UPF_BOOT_AUTOCONF) {
2184 if (!(port->flags & UPF_FIXED_TYPE)) {
2185 port->type = PORT_UNKNOWN;
2186 flags |= UART_CONFIG_TYPE;
2187 }
2188 port->ops->config_port(port, flags);
2189 }
2190
2191 if (port->type != PORT_UNKNOWN) {
2192 unsigned long flags;
2193
2194 uart_report_port(drv, port);
2195
2196 /* Power up port for set_mctrl() */
2197 uart_change_pm(state, UART_PM_STATE_ON);
2198
2199 /*
2200 * Ensure that the modem control lines are de-activated.
2201 * keep the DTR setting that is set in uart_set_options()
2202 * We probably don't need a spinlock around this, but
2203 */
2204 spin_lock_irqsave(&port->lock, flags);
2205 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2206 spin_unlock_irqrestore(&port->lock, flags);
2207
2208 /*
2209 * If this driver supports console, and it hasn't been
2210 * successfully registered yet, try to re-register it.
2211 * It may be that the port was not available.
2212 */
2213 if (port->cons && !(port->cons->flags & CON_ENABLED))
2214 register_console(port->cons);
2215
2216 /*
2217 * Power down all ports by default, except the
2218 * console if we have one.
2219 */
2220 if (!uart_console(port))
2221 uart_change_pm(state, UART_PM_STATE_OFF);
2222 }
2223}
2224
2225#ifdef CONFIG_CONSOLE_POLL
2226
2227static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2228{
2229 struct uart_driver *drv = driver->driver_state;
2230 struct uart_state *state = drv->state + line;
2231 struct uart_port *port;
2232 int baud = 9600;
2233 int bits = 8;
2234 int parity = 'n';
2235 int flow = 'n';
2236 int ret;
2237
2238 if (!state || !state->uart_port)
2239 return -1;
2240
2241 port = state->uart_port;
2242 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2243 return -1;
2244
2245 if (port->ops->poll_init) {
2246 struct tty_port *tport = &state->port;
2247
2248 ret = 0;
2249 mutex_lock(&tport->mutex);
2250 /*
2251 * We don't set ASYNCB_INITIALIZED as we only initialized the
2252 * hw, e.g. state->xmit is still uninitialized.
2253 */
2254 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2255 ret = port->ops->poll_init(port);
2256 mutex_unlock(&tport->mutex);
2257 if (ret)
2258 return ret;
2259 }
2260
2261 if (options) {
2262 uart_parse_options(options, &baud, &parity, &bits, &flow);
2263 return uart_set_options(port, NULL, baud, parity, bits, flow);
2264 }
2265
2266 return 0;
2267}
2268
2269static int uart_poll_get_char(struct tty_driver *driver, int line)
2270{
2271 struct uart_driver *drv = driver->driver_state;
2272 struct uart_state *state = drv->state + line;
2273 struct uart_port *port;
2274
2275 if (!state || !state->uart_port)
2276 return -1;
2277
2278 port = state->uart_port;
2279 return port->ops->poll_get_char(port);
2280}
2281
2282static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2283{
2284 struct uart_driver *drv = driver->driver_state;
2285 struct uart_state *state = drv->state + line;
2286 struct uart_port *port;
2287
2288 if (!state || !state->uart_port)
2289 return;
2290
2291 port = state->uart_port;
2292
2293 if (ch == '\n')
2294 port->ops->poll_put_char(port, '\r');
2295 port->ops->poll_put_char(port, ch);
2296}
2297#endif
2298
2299static const struct tty_operations uart_ops = {
2300 .open = uart_open,
2301 .close = uart_close,
2302 .write = uart_write,
2303 .put_char = uart_put_char,
2304 .flush_chars = uart_flush_chars,
2305 .write_room = uart_write_room,
2306 .chars_in_buffer= uart_chars_in_buffer,
2307 .flush_buffer = uart_flush_buffer,
2308 .ioctl = uart_ioctl,
2309 .throttle = uart_throttle,
2310 .unthrottle = uart_unthrottle,
2311 .send_xchar = uart_send_xchar,
2312 .set_termios = uart_set_termios,
2313 .set_ldisc = uart_set_ldisc,
2314 .stop = uart_stop,
2315 .start = uart_start,
2316 .hangup = uart_hangup,
2317 .break_ctl = uart_break_ctl,
2318 .wait_until_sent= uart_wait_until_sent,
2319#ifdef CONFIG_PROC_FS
2320 .proc_fops = &uart_proc_fops,
2321#endif
2322 .tiocmget = uart_tiocmget,
2323 .tiocmset = uart_tiocmset,
2324 .get_icount = uart_get_icount,
2325#ifdef CONFIG_CONSOLE_POLL
2326 .poll_init = uart_poll_init,
2327 .poll_get_char = uart_poll_get_char,
2328 .poll_put_char = uart_poll_put_char,
2329#endif
2330};
2331
2332static const struct tty_port_operations uart_port_ops = {
2333 .carrier_raised = uart_carrier_raised,
2334 .dtr_rts = uart_dtr_rts,
2335};
2336
2337/**
2338 * uart_register_driver - register a driver with the uart core layer
2339 * @drv: low level driver structure
2340 *
2341 * Register a uart driver with the core driver. We in turn register
2342 * with the tty layer, and initialise the core driver per-port state.
2343 *
2344 * We have a proc file in /proc/tty/driver which is named after the
2345 * normal driver.
2346 *
2347 * drv->port should be NULL, and the per-port structures should be
2348 * registered using uart_add_one_port after this call has succeeded.
2349 */
2350int uart_register_driver(struct uart_driver *drv)
2351{
2352 struct tty_driver *normal;
2353 int i, retval;
2354
2355 BUG_ON(drv->state);
2356
2357 /*
2358 * Maybe we should be using a slab cache for this, especially if
2359 * we have a large number of ports to handle.
2360 */
2361 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2362 if (!drv->state)
2363 goto out;
2364
2365 normal = alloc_tty_driver(drv->nr);
2366 if (!normal)
2367 goto out_kfree;
2368
2369 drv->tty_driver = normal;
2370
2371 normal->driver_name = drv->driver_name;
2372 normal->name = drv->dev_name;
2373 normal->major = drv->major;
2374 normal->minor_start = drv->minor;
2375 normal->type = TTY_DRIVER_TYPE_SERIAL;
2376 normal->subtype = SERIAL_TYPE_NORMAL;
2377 normal->init_termios = tty_std_termios;
2378 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2379 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2380 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2381 normal->driver_state = drv;
2382 tty_set_operations(normal, &uart_ops);
2383
2384 /*
2385 * Initialise the UART state(s).
2386 */
2387 for (i = 0; i < drv->nr; i++) {
2388 struct uart_state *state = drv->state + i;
2389 struct tty_port *port = &state->port;
2390
2391 tty_port_init(port);
2392 port->ops = &uart_port_ops;
2393 }
2394
2395 retval = tty_register_driver(normal);
2396 if (retval >= 0)
2397 return retval;
2398
2399 for (i = 0; i < drv->nr; i++)
2400 tty_port_destroy(&drv->state[i].port);
2401 put_tty_driver(normal);
2402out_kfree:
2403 kfree(drv->state);
2404out:
2405 return -ENOMEM;
2406}
2407
2408/**
2409 * uart_unregister_driver - remove a driver from the uart core layer
2410 * @drv: low level driver structure
2411 *
2412 * Remove all references to a driver from the core driver. The low
2413 * level driver must have removed all its ports via the
2414 * uart_remove_one_port() if it registered them with uart_add_one_port().
2415 * (ie, drv->port == NULL)
2416 */
2417void uart_unregister_driver(struct uart_driver *drv)
2418{
2419 struct tty_driver *p = drv->tty_driver;
2420 unsigned int i;
2421
2422 tty_unregister_driver(p);
2423 put_tty_driver(p);
2424 for (i = 0; i < drv->nr; i++)
2425 tty_port_destroy(&drv->state[i].port);
2426 kfree(drv->state);
2427 drv->state = NULL;
2428 drv->tty_driver = NULL;
2429}
2430
2431struct tty_driver *uart_console_device(struct console *co, int *index)
2432{
2433 struct uart_driver *p = co->data;
2434 *index = co->index;
2435 return p->tty_driver;
2436}
2437
2438static ssize_t uart_get_attr_uartclk(struct device *dev,
2439 struct device_attribute *attr, char *buf)
2440{
2441 struct serial_struct tmp;
2442 struct tty_port *port = dev_get_drvdata(dev);
2443
2444 uart_get_info(port, &tmp);
2445 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2446}
2447
2448static ssize_t uart_get_attr_type(struct device *dev,
2449 struct device_attribute *attr, char *buf)
2450{
2451 struct serial_struct tmp;
2452 struct tty_port *port = dev_get_drvdata(dev);
2453
2454 uart_get_info(port, &tmp);
2455 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2456}
2457static ssize_t uart_get_attr_line(struct device *dev,
2458 struct device_attribute *attr, char *buf)
2459{
2460 struct serial_struct tmp;
2461 struct tty_port *port = dev_get_drvdata(dev);
2462
2463 uart_get_info(port, &tmp);
2464 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2465}
2466
2467static ssize_t uart_get_attr_port(struct device *dev,
2468 struct device_attribute *attr, char *buf)
2469{
2470 struct serial_struct tmp;
2471 struct tty_port *port = dev_get_drvdata(dev);
2472 unsigned long ioaddr;
2473
2474 uart_get_info(port, &tmp);
2475 ioaddr = tmp.port;
2476 if (HIGH_BITS_OFFSET)
2477 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2478 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2479}
2480
2481static ssize_t uart_get_attr_irq(struct device *dev,
2482 struct device_attribute *attr, char *buf)
2483{
2484 struct serial_struct tmp;
2485 struct tty_port *port = dev_get_drvdata(dev);
2486
2487 uart_get_info(port, &tmp);
2488 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2489}
2490
2491static ssize_t uart_get_attr_flags(struct device *dev,
2492 struct device_attribute *attr, char *buf)
2493{
2494 struct serial_struct tmp;
2495 struct tty_port *port = dev_get_drvdata(dev);
2496
2497 uart_get_info(port, &tmp);
2498 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2499}
2500
2501static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2502 struct device_attribute *attr, char *buf)
2503{
2504 struct serial_struct tmp;
2505 struct tty_port *port = dev_get_drvdata(dev);
2506
2507 uart_get_info(port, &tmp);
2508 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2509}
2510
2511
2512static ssize_t uart_get_attr_close_delay(struct device *dev,
2513 struct device_attribute *attr, char *buf)
2514{
2515 struct serial_struct tmp;
2516 struct tty_port *port = dev_get_drvdata(dev);
2517
2518 uart_get_info(port, &tmp);
2519 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2520}
2521
2522
2523static ssize_t uart_get_attr_closing_wait(struct device *dev,
2524 struct device_attribute *attr, char *buf)
2525{
2526 struct serial_struct tmp;
2527 struct tty_port *port = dev_get_drvdata(dev);
2528
2529 uart_get_info(port, &tmp);
2530 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2531}
2532
2533static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2534 struct device_attribute *attr, char *buf)
2535{
2536 struct serial_struct tmp;
2537 struct tty_port *port = dev_get_drvdata(dev);
2538
2539 uart_get_info(port, &tmp);
2540 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2541}
2542
2543static ssize_t uart_get_attr_io_type(struct device *dev,
2544 struct device_attribute *attr, char *buf)
2545{
2546 struct serial_struct tmp;
2547 struct tty_port *port = dev_get_drvdata(dev);
2548
2549 uart_get_info(port, &tmp);
2550 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2551}
2552
2553static ssize_t uart_get_attr_iomem_base(struct device *dev,
2554 struct device_attribute *attr, char *buf)
2555{
2556 struct serial_struct tmp;
2557 struct tty_port *port = dev_get_drvdata(dev);
2558
2559 uart_get_info(port, &tmp);
2560 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2561}
2562
2563static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2564 struct device_attribute *attr, char *buf)
2565{
2566 struct serial_struct tmp;
2567 struct tty_port *port = dev_get_drvdata(dev);
2568
2569 uart_get_info(port, &tmp);
2570 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2571}
2572
2573static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2574static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2575static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2576static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2577static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2578static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2579static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2580static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2581static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2582static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2583static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2584static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2585static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2586
2587static struct attribute *tty_dev_attrs[] = {
2588 &dev_attr_type.attr,
2589 &dev_attr_line.attr,
2590 &dev_attr_port.attr,
2591 &dev_attr_irq.attr,
2592 &dev_attr_flags.attr,
2593 &dev_attr_xmit_fifo_size.attr,
2594 &dev_attr_uartclk.attr,
2595 &dev_attr_close_delay.attr,
2596 &dev_attr_closing_wait.attr,
2597 &dev_attr_custom_divisor.attr,
2598 &dev_attr_io_type.attr,
2599 &dev_attr_iomem_base.attr,
2600 &dev_attr_iomem_reg_shift.attr,
2601 NULL,
2602 };
2603
2604static const struct attribute_group tty_dev_attr_group = {
2605 .attrs = tty_dev_attrs,
2606 };
2607
2608/**
2609 * uart_add_one_port - attach a driver-defined port structure
2610 * @drv: pointer to the uart low level driver structure for this port
2611 * @uport: uart port structure to use for this port.
2612 *
2613 * This allows the driver to register its own uart_port structure
2614 * with the core driver. The main purpose is to allow the low
2615 * level uart drivers to expand uart_port, rather than having yet
2616 * more levels of structures.
2617 */
2618int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2619{
2620 struct uart_state *state;
2621 struct tty_port *port;
2622 int ret = 0;
2623 struct device *tty_dev;
2624 int num_groups;
2625
2626 BUG_ON(in_interrupt());
2627
2628 if (uport->line >= drv->nr)
2629 return -EINVAL;
2630
2631 state = drv->state + uport->line;
2632 port = &state->port;
2633
2634 mutex_lock(&port_mutex);
2635 mutex_lock(&port->mutex);
2636 if (state->uart_port) {
2637 ret = -EINVAL;
2638 goto out;
2639 }
2640
2641 /* Link the port to the driver state table and vice versa */
2642 state->uart_port = uport;
2643 uport->state = state;
2644
2645 state->pm_state = UART_PM_STATE_UNDEFINED;
2646 uport->cons = drv->cons;
2647 uport->minor = drv->tty_driver->minor_start + uport->line;
2648
2649 /*
2650 * If this port is a console, then the spinlock is already
2651 * initialised.
2652 */
2653 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2654 spin_lock_init(&uport->lock);
2655 lockdep_set_class(&uport->lock, &port_lock_key);
2656 }
2657 if (uport->cons && uport->dev)
2658 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2659
2660 uart_configure_port(drv, state, uport);
2661
2662 num_groups = 2;
2663 if (uport->attr_group)
2664 num_groups++;
2665
2666 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2667 GFP_KERNEL);
2668 if (!uport->tty_groups) {
2669 ret = -ENOMEM;
2670 goto out;
2671 }
2672 uport->tty_groups[0] = &tty_dev_attr_group;
2673 if (uport->attr_group)
2674 uport->tty_groups[1] = uport->attr_group;
2675
2676 /*
2677 * Register the port whether it's detected or not. This allows
2678 * setserial to be used to alter this port's parameters.
2679 */
2680 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2681 uport->line, uport->dev, port, uport->tty_groups);
2682 if (likely(!IS_ERR(tty_dev))) {
2683 device_set_wakeup_capable(tty_dev, 1);
2684 } else {
2685 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2686 uport->line);
2687 }
2688
2689 /*
2690 * Ensure UPF_DEAD is not set.
2691 */
2692 uport->flags &= ~UPF_DEAD;
2693
2694 out:
2695 mutex_unlock(&port->mutex);
2696 mutex_unlock(&port_mutex);
2697
2698 return ret;
2699}
2700
2701/**
2702 * uart_remove_one_port - detach a driver defined port structure
2703 * @drv: pointer to the uart low level driver structure for this port
2704 * @uport: uart port structure for this port
2705 *
2706 * This unhooks (and hangs up) the specified port structure from the
2707 * core driver. No further calls will be made to the low-level code
2708 * for this port.
2709 */
2710int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2711{
2712 struct uart_state *state = drv->state + uport->line;
2713 struct tty_port *port = &state->port;
2714 struct tty_struct *tty;
2715 int ret = 0;
2716
2717 BUG_ON(in_interrupt());
2718
2719 if (state->uart_port != uport)
2720 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2721 state->uart_port, uport);
2722
2723 mutex_lock(&port_mutex);
2724
2725 /*
2726 * Mark the port "dead" - this prevents any opens from
2727 * succeeding while we shut down the port.
2728 */
2729 mutex_lock(&port->mutex);
2730 if (!state->uart_port) {
2731 mutex_unlock(&port->mutex);
2732 ret = -EINVAL;
2733 goto out;
2734 }
2735 uport->flags |= UPF_DEAD;
2736 mutex_unlock(&port->mutex);
2737
2738 /*
2739 * Remove the devices from the tty layer
2740 */
2741 tty_unregister_device(drv->tty_driver, uport->line);
2742
2743 tty = tty_port_tty_get(port);
2744 if (tty) {
2745 tty_vhangup(port->tty);
2746 tty_kref_put(tty);
2747 }
2748
2749 /*
2750 * If the port is used as a console, unregister it
2751 */
2752 if (uart_console(uport))
2753 unregister_console(uport->cons);
2754
2755 /*
2756 * Free the port IO and memory resources, if any.
2757 */
2758 if (uport->type != PORT_UNKNOWN)
2759 uport->ops->release_port(uport);
2760 kfree(uport->tty_groups);
2761
2762 /*
2763 * Indicate that there isn't a port here anymore.
2764 */
2765 uport->type = PORT_UNKNOWN;
2766
2767 state->uart_port = NULL;
2768out:
2769 mutex_unlock(&port_mutex);
2770
2771 return ret;
2772}
2773
2774/*
2775 * Are the two ports equivalent?
2776 */
2777int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2778{
2779 if (port1->iotype != port2->iotype)
2780 return 0;
2781
2782 switch (port1->iotype) {
2783 case UPIO_PORT:
2784 return (port1->iobase == port2->iobase);
2785 case UPIO_HUB6:
2786 return (port1->iobase == port2->iobase) &&
2787 (port1->hub6 == port2->hub6);
2788 case UPIO_MEM:
2789 case UPIO_MEM16:
2790 case UPIO_MEM32:
2791 case UPIO_MEM32BE:
2792 case UPIO_AU:
2793 case UPIO_TSI:
2794 return (port1->mapbase == port2->mapbase);
2795 }
2796 return 0;
2797}
2798EXPORT_SYMBOL(uart_match_port);
2799
2800/**
2801 * uart_handle_dcd_change - handle a change of carrier detect state
2802 * @uport: uart_port structure for the open port
2803 * @status: new carrier detect status, nonzero if active
2804 *
2805 * Caller must hold uport->lock
2806 */
2807void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2808{
2809 struct tty_port *port = &uport->state->port;
2810 struct tty_struct *tty = port->tty;
2811 struct tty_ldisc *ld;
2812
2813 lockdep_assert_held_once(&uport->lock);
2814
2815 if (tty) {
2816 ld = tty_ldisc_ref(tty);
2817 if (ld) {
2818 if (ld->ops->dcd_change)
2819 ld->ops->dcd_change(tty, status);
2820 tty_ldisc_deref(ld);
2821 }
2822 }
2823
2824 uport->icount.dcd++;
2825
2826 if (uart_dcd_enabled(uport)) {
2827 if (status)
2828 wake_up_interruptible(&port->open_wait);
2829 else if (tty)
2830 tty_hangup(tty);
2831 }
2832}
2833EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2834
2835/**
2836 * uart_handle_cts_change - handle a change of clear-to-send state
2837 * @uport: uart_port structure for the open port
2838 * @status: new clear to send status, nonzero if active
2839 *
2840 * Caller must hold uport->lock
2841 */
2842void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2843{
2844 lockdep_assert_held_once(&uport->lock);
2845
2846 uport->icount.cts++;
2847
2848 if (uart_softcts_mode(uport)) {
2849 if (uport->hw_stopped) {
2850 if (status) {
2851 uport->hw_stopped = 0;
2852 uport->ops->start_tx(uport);
2853 uart_write_wakeup(uport);
2854 }
2855 } else {
2856 if (!status) {
2857 uport->hw_stopped = 1;
2858 uport->ops->stop_tx(uport);
2859 }
2860 }
2861
2862 }
2863}
2864EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2865
2866/**
2867 * uart_insert_char - push a char to the uart layer
2868 *
2869 * User is responsible to call tty_flip_buffer_push when they are done with
2870 * insertion.
2871 *
2872 * @port: corresponding port
2873 * @status: state of the serial port RX buffer (LSR for 8250)
2874 * @overrun: mask of overrun bits in @status
2875 * @ch: character to push
2876 * @flag: flag for the character (see TTY_NORMAL and friends)
2877 */
2878void uart_insert_char(struct uart_port *port, unsigned int status,
2879 unsigned int overrun, unsigned int ch, unsigned int flag)
2880{
2881 struct tty_port *tport = &port->state->port;
2882
2883 if ((status & port->ignore_status_mask & ~overrun) == 0)
2884 if (tty_insert_flip_char(tport, ch, flag) == 0)
2885 ++port->icount.buf_overrun;
2886
2887 /*
2888 * Overrun is special. Since it's reported immediately,
2889 * it doesn't affect the current character.
2890 */
2891 if (status & ~port->ignore_status_mask & overrun)
2892 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2893 ++port->icount.buf_overrun;
2894}
2895EXPORT_SYMBOL_GPL(uart_insert_char);
2896
2897EXPORT_SYMBOL(uart_write_wakeup);
2898EXPORT_SYMBOL(uart_register_driver);
2899EXPORT_SYMBOL(uart_unregister_driver);
2900EXPORT_SYMBOL(uart_suspend_port);
2901EXPORT_SYMBOL(uart_resume_port);
2902EXPORT_SYMBOL(uart_add_one_port);
2903EXPORT_SYMBOL(uart_remove_one_port);
2904
2905MODULE_DESCRIPTION("Serial driver core");
2906MODULE_LICENSE("GPL");