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Avoid beyond bounds copy while caching ACL
[zen-stable.git] / drivers / mmc / card / sdio_uart.c
blob2c151e18c9e847b147798386fd2effdb03b4465e
1 /*
2 * linux/drivers/mmc/card/sdio_uart.c - SDIO UART/GPS driver
3 *
4 * Based on drivers/serial/8250.c and drivers/serial/serial_core.c
5 * by Russell King.
6 *
7 * Author: Nicolas Pitre
8 * Created: June 15, 2007
9 * Copyright: MontaVista Software, Inc.
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or (at
14 * your option) any later version.
15 */
16
17 /*
18 * Note: Although this driver assumes a 16550A-like UART implementation,
19 * it is not possible to leverage the common 8250/16550 driver, nor the
20 * core UART infrastructure, as they assumes direct access to the hardware
21 * registers, often under a spinlock. This is not possible in the SDIO
22 * context as SDIO access functions must be able to sleep.
23 *
24 * Because we need to lock the SDIO host to ensure an exclusive access to
25 * the card, we simply rely on that lock to also prevent and serialize
26 * concurrent access to the same port.
27 */
28
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/kernel.h>
32 #include <linux/sched.h>
33 #include <linux/mutex.h>
34 #include <linux/seq_file.h>
35 #include <linux/serial_reg.h>
36 #include <linux/circ_buf.h>
37 #include <linux/tty.h>
38 #include <linux/tty_flip.h>
39 #include <linux/kfifo.h>
40 #include <linux/slab.h>
41
42 #include <linux/mmc/core.h>
43 #include <linux/mmc/card.h>
44 #include <linux/mmc/sdio_func.h>
45 #include <linux/mmc/sdio_ids.h>
46
47
48 #define UART_NR 8 /* Number of UARTs this driver can handle */
49
50
51 #define FIFO_SIZE PAGE_SIZE
52 #define WAKEUP_CHARS 256
53
54 struct uart_icount {
55 __u32 cts;
56 __u32 dsr;
57 __u32 rng;
58 __u32 dcd;
59 __u32 rx;
60 __u32 tx;
61 __u32 frame;
62 __u32 overrun;
63 __u32 parity;
64 __u32 brk;
65 };
66
67 struct sdio_uart_port {
68 struct tty_port port;
69 struct kref kref;
70 struct tty_struct *tty;
71 unsigned int index;
72 struct sdio_func *func;
73 struct mutex func_lock;
74 struct task_struct *in_sdio_uart_irq;
75 unsigned int regs_offset;
76 struct kfifo xmit_fifo;
77 spinlock_t write_lock;
78 struct uart_icount icount;
79 unsigned int uartclk;
80 unsigned int mctrl;
81 unsigned int rx_mctrl;
82 unsigned int read_status_mask;
83 unsigned int ignore_status_mask;
84 unsigned char x_char;
85 unsigned char ier;
86 unsigned char lcr;
87 };
88
89 static struct sdio_uart_port *sdio_uart_table[UART_NR];
90 static DEFINE_SPINLOCK(sdio_uart_table_lock);
91
92 static int sdio_uart_add_port(struct sdio_uart_port *port)
93 {
94 int index, ret = -EBUSY;
95
96 kref_init(&port->kref);
97 mutex_init(&port->func_lock);
98 spin_lock_init(&port->write_lock);
99 if (kfifo_alloc(&port->xmit_fifo, FIFO_SIZE, GFP_KERNEL))
100 return -ENOMEM;
101
102 spin_lock(&sdio_uart_table_lock);
103 for (index = 0; index < UART_NR; index++) {
104 if (!sdio_uart_table[index]) {
105 port->index = index;
106 sdio_uart_table[index] = port;
107 ret = 0;
108 break;
109 }
110 }
111 spin_unlock(&sdio_uart_table_lock);
112
113 return ret;
114 }
115
116 static struct sdio_uart_port *sdio_uart_port_get(unsigned index)
117 {
118 struct sdio_uart_port *port;
119
120 if (index >= UART_NR)
121 return NULL;
122
123 spin_lock(&sdio_uart_table_lock);
124 port = sdio_uart_table[index];
125 if (port)
126 kref_get(&port->kref);
127 spin_unlock(&sdio_uart_table_lock);
128
129 return port;
130 }
131
132 static void sdio_uart_port_destroy(struct kref *kref)
133 {
134 struct sdio_uart_port *port =
135 container_of(kref, struct sdio_uart_port, kref);
136 kfifo_free(&port->xmit_fifo);
137 kfree(port);
138 }
139
140 static void sdio_uart_port_put(struct sdio_uart_port *port)
141 {
142 kref_put(&port->kref, sdio_uart_port_destroy);
143 }
144
145 static void sdio_uart_port_remove(struct sdio_uart_port *port)
146 {
147 struct sdio_func *func;
148 struct tty_struct *tty;
149
150 BUG_ON(sdio_uart_table[port->index] != port);
151
152 spin_lock(&sdio_uart_table_lock);
153 sdio_uart_table[port->index] = NULL;
154 spin_unlock(&sdio_uart_table_lock);
155
156 /*
157 * We're killing a port that potentially still is in use by
158 * the tty layer. Be careful to prevent any further access
159 * to the SDIO function and arrange for the tty layer to
160 * give up on that port ASAP.
161 * Beware: the lock ordering is critical.
162 */
163 mutex_lock(&port->port.mutex);
164 mutex_lock(&port->func_lock);
165 func = port->func;
166 sdio_claim_host(func);
167 port->func = NULL;
168 mutex_unlock(&port->func_lock);
169 tty = tty_port_tty_get(&port->port);
170 /* tty_hangup is async so is this safe as is ?? */
171 if (tty) {
172 tty_hangup(tty);
173 tty_kref_put(tty);
174 }
175 mutex_unlock(&port->port.mutex);
176 sdio_release_irq(func);
177 sdio_disable_func(func);
178 sdio_release_host(func);
179
180 sdio_uart_port_put(port);
181 }
182
183 static int sdio_uart_claim_func(struct sdio_uart_port *port)
184 {
185 mutex_lock(&port->func_lock);
186 if (unlikely(!port->func)) {
187 mutex_unlock(&port->func_lock);
188 return -ENODEV;
189 }
190 if (likely(port->in_sdio_uart_irq != current))
191 sdio_claim_host(port->func);
192 mutex_unlock(&port->func_lock);
193 return 0;
194 }
195
196 static inline void sdio_uart_release_func(struct sdio_uart_port *port)
197 {
198 if (likely(port->in_sdio_uart_irq != current))
199 sdio_release_host(port->func);
200 }
201
202 static inline unsigned int sdio_in(struct sdio_uart_port *port, int offset)
203 {
204 unsigned char c;
205 c = sdio_readb(port->func, port->regs_offset + offset, NULL);
206 return c;
207 }
208
209 static inline void sdio_out(struct sdio_uart_port *port, int offset, int value)
210 {
211 sdio_writeb(port->func, value, port->regs_offset + offset, NULL);
212 }
213
214 static unsigned int sdio_uart_get_mctrl(struct sdio_uart_port *port)
215 {
216 unsigned char status;
217 unsigned int ret;
218
219 /* FIXME: What stops this losing the delta bits and breaking
220 sdio_uart_check_modem_status ? */
221 status = sdio_in(port, UART_MSR);
222
223 ret = 0;
224 if (status & UART_MSR_DCD)
225 ret |= TIOCM_CAR;
226 if (status & UART_MSR_RI)
227 ret |= TIOCM_RNG;
228 if (status & UART_MSR_DSR)
229 ret |= TIOCM_DSR;
230 if (status & UART_MSR_CTS)
231 ret |= TIOCM_CTS;
232 return ret;
233 }
234
235 static void sdio_uart_write_mctrl(struct sdio_uart_port *port,
236 unsigned int mctrl)
237 {
238 unsigned char mcr = 0;
239
240 if (mctrl & TIOCM_RTS)
241 mcr |= UART_MCR_RTS;
242 if (mctrl & TIOCM_DTR)
243 mcr |= UART_MCR_DTR;
244 if (mctrl & TIOCM_OUT1)
245 mcr |= UART_MCR_OUT1;
246 if (mctrl & TIOCM_OUT2)
247 mcr |= UART_MCR_OUT2;
248 if (mctrl & TIOCM_LOOP)
249 mcr |= UART_MCR_LOOP;
250
251 sdio_out(port, UART_MCR, mcr);
252 }
253
254 static inline void sdio_uart_update_mctrl(struct sdio_uart_port *port,
255 unsigned int set, unsigned int clear)
256 {
257 unsigned int old;
258
259 old = port->mctrl;
260 port->mctrl = (old & ~clear) | set;
261 if (old != port->mctrl)
262 sdio_uart_write_mctrl(port, port->mctrl);
263 }
264
265 #define sdio_uart_set_mctrl(port, x) sdio_uart_update_mctrl(port, x, 0)
266 #define sdio_uart_clear_mctrl(port, x) sdio_uart_update_mctrl(port, 0, x)
267
268 static void sdio_uart_change_speed(struct sdio_uart_port *port,
269 struct ktermios *termios,
270 struct ktermios *old)
271 {
272 unsigned char cval, fcr = 0;
273 unsigned int baud, quot;
274
275 switch (termios->c_cflag & CSIZE) {
276 case CS5:
277 cval = UART_LCR_WLEN5;
278 break;
279 case CS6:
280 cval = UART_LCR_WLEN6;
281 break;
282 case CS7:
283 cval = UART_LCR_WLEN7;
284 break;
285 default:
286 case CS8:
287 cval = UART_LCR_WLEN8;
288 break;
289 }
290
291 if (termios->c_cflag & CSTOPB)
292 cval |= UART_LCR_STOP;
293 if (termios->c_cflag & PARENB)
294 cval |= UART_LCR_PARITY;
295 if (!(termios->c_cflag & PARODD))
296 cval |= UART_LCR_EPAR;
297
298 for (;;) {
299 baud = tty_termios_baud_rate(termios);
300 if (baud == 0)
301 baud = 9600; /* Special case: B0 rate. */
302 if (baud <= port->uartclk)
303 break;
304 /*
305 * Oops, the quotient was zero. Try again with the old
306 * baud rate if possible, otherwise default to 9600.
307 */
308 termios->c_cflag &= ~CBAUD;
309 if (old) {
310 termios->c_cflag |= old->c_cflag & CBAUD;
311 old = NULL;
312 } else
313 termios->c_cflag |= B9600;
314 }
315 quot = (2 * port->uartclk + baud) / (2 * baud);
316
317 if (baud < 2400)
318 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
319 else
320 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10;
321
322 port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
323 if (termios->c_iflag & INPCK)
324 port->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
325 if (termios->c_iflag & (BRKINT | PARMRK))
326 port->read_status_mask |= UART_LSR_BI;
327
328 /*
329 * Characters to ignore
330 */
331 port->ignore_status_mask = 0;
332 if (termios->c_iflag & IGNPAR)
333 port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
334 if (termios->c_iflag & IGNBRK) {
335 port->ignore_status_mask |= UART_LSR_BI;
336 /*
337 * If we're ignoring parity and break indicators,
338 * ignore overruns too (for real raw support).
339 */
340 if (termios->c_iflag & IGNPAR)
341 port->ignore_status_mask |= UART_LSR_OE;
342 }
343
344 /*
345 * ignore all characters if CREAD is not set
346 */
347 if ((termios->c_cflag & CREAD) == 0)
348 port->ignore_status_mask |= UART_LSR_DR;
349
350 /*
351 * CTS flow control flag and modem status interrupts
352 */
353 port->ier &= ~UART_IER_MSI;
354 if ((termios->c_cflag & CRTSCTS) || !(termios->c_cflag & CLOCAL))
355 port->ier |= UART_IER_MSI;
356
357 port->lcr = cval;
358
359 sdio_out(port, UART_IER, port->ier);
360 sdio_out(port, UART_LCR, cval | UART_LCR_DLAB);
361 sdio_out(port, UART_DLL, quot & 0xff);
362 sdio_out(port, UART_DLM, quot >> 8);
363 sdio_out(port, UART_LCR, cval);
364 sdio_out(port, UART_FCR, fcr);
365
366 sdio_uart_write_mctrl(port, port->mctrl);
367 }
368
369 static void sdio_uart_start_tx(struct sdio_uart_port *port)
370 {
371 if (!(port->ier & UART_IER_THRI)) {
372 port->ier |= UART_IER_THRI;
373 sdio_out(port, UART_IER, port->ier);
374 }
375 }
376
377 static void sdio_uart_stop_tx(struct sdio_uart_port *port)
378 {
379 if (port->ier & UART_IER_THRI) {
380 port->ier &= ~UART_IER_THRI;
381 sdio_out(port, UART_IER, port->ier);
382 }
383 }
384
385 static void sdio_uart_stop_rx(struct sdio_uart_port *port)
386 {
387 port->ier &= ~UART_IER_RLSI;
388 port->read_status_mask &= ~UART_LSR_DR;
389 sdio_out(port, UART_IER, port->ier);
390 }
391
392 static void sdio_uart_receive_chars(struct sdio_uart_port *port,
393 unsigned int *status)
394 {
395 struct tty_struct *tty = tty_port_tty_get(&port->port);
396 unsigned int ch, flag;
397 int max_count = 256;
398
399 do {
400 ch = sdio_in(port, UART_RX);
401 flag = TTY_NORMAL;
402 port->icount.rx++;
403
404 if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
405 UART_LSR_FE | UART_LSR_OE))) {
406 /*
407 * For statistics only
408 */
409 if (*status & UART_LSR_BI) {
410 *status &= ~(UART_LSR_FE | UART_LSR_PE);
411 port->icount.brk++;
412 } else if (*status & UART_LSR_PE)
413 port->icount.parity++;
414 else if (*status & UART_LSR_FE)
415 port->icount.frame++;
416 if (*status & UART_LSR_OE)
417 port->icount.overrun++;
418
419 /*
420 * Mask off conditions which should be ignored.
421 */
422 *status &= port->read_status_mask;
423 if (*status & UART_LSR_BI)
424 flag = TTY_BREAK;
425 else if (*status & UART_LSR_PE)
426 flag = TTY_PARITY;
427 else if (*status & UART_LSR_FE)
428 flag = TTY_FRAME;
429 }
430
431 if ((*status & port->ignore_status_mask & ~UART_LSR_OE) == 0)
432 if (tty)
433 tty_insert_flip_char(tty, ch, flag);
434
435 /*
436 * Overrun is special. Since it's reported immediately,
437 * it doesn't affect the current character.
438 */
439 if (*status & ~port->ignore_status_mask & UART_LSR_OE)
440 if (tty)
441 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
442
443 *status = sdio_in(port, UART_LSR);
444 } while ((*status & UART_LSR_DR) && (max_count-- > 0));
445 if (tty) {
446 tty_flip_buffer_push(tty);
447 tty_kref_put(tty);
448 }
449 }
450
451 static void sdio_uart_transmit_chars(struct sdio_uart_port *port)
452 {
453 struct kfifo *xmit = &port->xmit_fifo;
454 int count;
455 struct tty_struct *tty;
456 u8 iobuf[16];
457 int len;
458
459 if (port->x_char) {
460 sdio_out(port, UART_TX, port->x_char);
461 port->icount.tx++;
462 port->x_char = 0;
463 return;
464 }
465
466 tty = tty_port_tty_get(&port->port);
467
468 if (tty == NULL || !kfifo_len(xmit) ||
469 tty->stopped || tty->hw_stopped) {
470 sdio_uart_stop_tx(port);
471 tty_kref_put(tty);
472 return;
473 }
474
475 len = kfifo_out_locked(xmit, iobuf, 16, &port->write_lock);
476 for (count = 0; count < len; count++) {
477 sdio_out(port, UART_TX, iobuf[count]);
478 port->icount.tx++;
479 }
480
481 len = kfifo_len(xmit);
482 if (len < WAKEUP_CHARS) {
483 tty_wakeup(tty);
484 if (len == 0)
485 sdio_uart_stop_tx(port);
486 }
487 tty_kref_put(tty);
488 }
489
490 static void sdio_uart_check_modem_status(struct sdio_uart_port *port)
491 {
492 int status;
493 struct tty_struct *tty;
494
495 status = sdio_in(port, UART_MSR);
496
497 if ((status & UART_MSR_ANY_DELTA) == 0)
498 return;
499
500 if (status & UART_MSR_TERI)
501 port->icount.rng++;
502 if (status & UART_MSR_DDSR)
503 port->icount.dsr++;
504 if (status & UART_MSR_DDCD) {
505 port->icount.dcd++;
506 /* DCD raise - wake for open */
507 if (status & UART_MSR_DCD)
508 wake_up_interruptible(&port->port.open_wait);
509 else {
510 /* DCD drop - hang up if tty attached */
511 tty = tty_port_tty_get(&port->port);
512 if (tty) {
513 tty_hangup(tty);
514 tty_kref_put(tty);
515 }
516 }
517 }
518 if (status & UART_MSR_DCTS) {
519 port->icount.cts++;
520 tty = tty_port_tty_get(&port->port);
521 if (tty && (tty->termios->c_cflag & CRTSCTS)) {
522 int cts = (status & UART_MSR_CTS);
523 if (tty->hw_stopped) {
524 if (cts) {
525 tty->hw_stopped = 0;
526 sdio_uart_start_tx(port);
527 tty_wakeup(tty);
528 }
529 } else {
530 if (!cts) {
531 tty->hw_stopped = 1;
532 sdio_uart_stop_tx(port);
533 }
534 }
535 }
536 tty_kref_put(tty);
537 }
538 }
539
540 /*
541 * This handles the interrupt from one port.
542 */
543 static void sdio_uart_irq(struct sdio_func *func)
544 {
545 struct sdio_uart_port *port = sdio_get_drvdata(func);
546 unsigned int iir, lsr;
547
548 /*
549 * In a few places sdio_uart_irq() is called directly instead of
550 * waiting for the actual interrupt to be raised and the SDIO IRQ
551 * thread scheduled in order to reduce latency. However, some
552 * interaction with the tty core may end up calling us back
553 * (serial echo, flow control, etc.) through those same places
554 * causing undesirable effects. Let's stop the recursion here.
555 */
556 if (unlikely(port->in_sdio_uart_irq == current))
557 return;
558
559 iir = sdio_in(port, UART_IIR);
560 if (iir & UART_IIR_NO_INT)
561 return;
562
563 port->in_sdio_uart_irq = current;
564 lsr = sdio_in(port, UART_LSR);
565 if (lsr & UART_LSR_DR)
566 sdio_uart_receive_chars(port, &lsr);
567 sdio_uart_check_modem_status(port);
568 if (lsr & UART_LSR_THRE)
569 sdio_uart_transmit_chars(port);
570 port->in_sdio_uart_irq = NULL;
571 }
572
573 static int uart_carrier_raised(struct tty_port *tport)
574 {
575 struct sdio_uart_port *port =
576 container_of(tport, struct sdio_uart_port, port);
577 unsigned int ret = sdio_uart_claim_func(port);
578 if (ret) /* Missing hardware shouldn't block for carrier */
579 return 1;
580 ret = sdio_uart_get_mctrl(port);
581 sdio_uart_release_func(port);
582 if (ret & TIOCM_CAR)
583 return 1;
584 return 0;
585 }
586
587 /**
588 * uart_dtr_rts - port helper to set uart signals
589 * @tport: tty port to be updated
590 * @onoff: set to turn on DTR/RTS
591 *
592 * Called by the tty port helpers when the modem signals need to be
593 * adjusted during an open, close and hangup.
594 */
595
596 static void uart_dtr_rts(struct tty_port *tport, int onoff)
597 {
598 struct sdio_uart_port *port =
599 container_of(tport, struct sdio_uart_port, port);
600 int ret = sdio_uart_claim_func(port);
601 if (ret)
602 return;
603 if (onoff == 0)
604 sdio_uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
605 else
606 sdio_uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
607 sdio_uart_release_func(port);
608 }
609
610 /**
611 * sdio_uart_activate - start up hardware
612 * @tport: tty port to activate
613 * @tty: tty bound to this port
614 *
615 * Activate a tty port. The port locking guarantees us this will be
616 * run exactly once per set of opens, and if successful will see the
617 * shutdown method run exactly once to match. Start up and shutdown are
618 * protected from each other by the internal locking and will not run
619 * at the same time even during a hangup event.
620 *
621 * If we successfully start up the port we take an extra kref as we
622 * will keep it around until shutdown when the kref is dropped.
623 */
624
625 static int sdio_uart_activate(struct tty_port *tport, struct tty_struct *tty)
626 {
627 struct sdio_uart_port *port =
628 container_of(tport, struct sdio_uart_port, port);
629 int ret;
630
631 /*
632 * Set the TTY IO error marker - we will only clear this
633 * once we have successfully opened the port.
634 */
635 set_bit(TTY_IO_ERROR, &tty->flags);
636
637 kfifo_reset(&port->xmit_fifo);
638
639 ret = sdio_uart_claim_func(port);
640 if (ret)
641 return ret;
642 ret = sdio_enable_func(port->func);
643 if (ret)
644 goto err1;
645 ret = sdio_claim_irq(port->func, sdio_uart_irq);
646 if (ret)
647 goto err2;
648
649 /*
650 * Clear the FIFO buffers and disable them.
651 * (they will be reenabled in sdio_change_speed())
652 */
653 sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO);
654 sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO |
655 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
656 sdio_out(port, UART_FCR, 0);
657
658 /*
659 * Clear the interrupt registers.
660 */
661 (void) sdio_in(port, UART_LSR);
662 (void) sdio_in(port, UART_RX);
663 (void) sdio_in(port, UART_IIR);
664 (void) sdio_in(port, UART_MSR);
665
666 /*
667 * Now, initialize the UART
668 */
669 sdio_out(port, UART_LCR, UART_LCR_WLEN8);
670
671 port->ier = UART_IER_RLSI|UART_IER_RDI|UART_IER_RTOIE|UART_IER_UUE;
672 port->mctrl = TIOCM_OUT2;
673
674 sdio_uart_change_speed(port, tty->termios, NULL);
675
676 if (tty->termios->c_cflag & CBAUD)
677 sdio_uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
678
679 if (tty->termios->c_cflag & CRTSCTS)
680 if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS))
681 tty->hw_stopped = 1;
682
683 clear_bit(TTY_IO_ERROR, &tty->flags);
684
685 /* Kick the IRQ handler once while we're still holding the host lock */
686 sdio_uart_irq(port->func);
687
688 sdio_uart_release_func(port);
689 return 0;
690
691 err2:
692 sdio_disable_func(port->func);
693 err1:
694 sdio_uart_release_func(port);
695 return ret;
696 }
697
698 /**
699 * sdio_uart_shutdown - stop hardware
700 * @tport: tty port to shut down
701 *
702 * Deactivate a tty port. The port locking guarantees us this will be
703 * run only if a successful matching activate already ran. The two are
704 * protected from each other by the internal locking and will not run
705 * at the same time even during a hangup event.
706 */
707
708 static void sdio_uart_shutdown(struct tty_port *tport)
709 {
710 struct sdio_uart_port *port =
711 container_of(tport, struct sdio_uart_port, port);
712 int ret;
713
714 ret = sdio_uart_claim_func(port);
715 if (ret)
716 return;
717
718 sdio_uart_stop_rx(port);
719
720 /* Disable interrupts from this port */
721 sdio_release_irq(port->func);
722 port->ier = 0;
723 sdio_out(port, UART_IER, 0);
724
725 sdio_uart_clear_mctrl(port, TIOCM_OUT2);
726
727 /* Disable break condition and FIFOs. */
728 port->lcr &= ~UART_LCR_SBC;
729 sdio_out(port, UART_LCR, port->lcr);
730 sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO |
731 UART_FCR_CLEAR_RCVR |
732 UART_FCR_CLEAR_XMIT);
733 sdio_out(port, UART_FCR, 0);
734
735 sdio_disable_func(port->func);
736
737 sdio_uart_release_func(port);
738 }
739
740 /**
741 * sdio_uart_install - install method
742 * @driver: the driver in use (sdio_uart in our case)
743 * @tty: the tty being bound
744 *
745 * Look up and bind the tty and the driver together. Initialize
746 * any needed private data (in our case the termios)
747 */
748
749 static int sdio_uart_install(struct tty_driver *driver, struct tty_struct *tty)
750 {
751 int idx = tty->index;
752 struct sdio_uart_port *port = sdio_uart_port_get(idx);
753 int ret = tty_init_termios(tty);
754
755 if (ret == 0) {
756 tty_driver_kref_get(driver);
757 tty->count++;
758 /* This is the ref sdio_uart_port get provided */
759 tty->driver_data = port;
760 driver->ttys[idx] = tty;
761 } else
762 sdio_uart_port_put(port);
763 return ret;
764 }
765
766 /**
767 * sdio_uart_cleanup - called on the last tty kref drop
768 * @tty: the tty being destroyed
769 *
770 * Called asynchronously when the last reference to the tty is dropped.
771 * We cannot destroy the tty->driver_data port kref until this point
772 */
773
774 static void sdio_uart_cleanup(struct tty_struct *tty)
775 {
776 struct sdio_uart_port *port = tty->driver_data;
777 tty->driver_data = NULL; /* Bug trap */
778 sdio_uart_port_put(port);
779 }
780
781 /*
782 * Open/close/hangup is now entirely boilerplate
783 */
784
785 static int sdio_uart_open(struct tty_struct *tty, struct file *filp)
786 {
787 struct sdio_uart_port *port = tty->driver_data;
788 return tty_port_open(&port->port, tty, filp);
789 }
790
791 static void sdio_uart_close(struct tty_struct *tty, struct file * filp)
792 {
793 struct sdio_uart_port *port = tty->driver_data;
794 tty_port_close(&port->port, tty, filp);
795 }
796
797 static void sdio_uart_hangup(struct tty_struct *tty)
798 {
799 struct sdio_uart_port *port = tty->driver_data;
800 tty_port_hangup(&port->port);
801 }
802
803 static int sdio_uart_write(struct tty_struct *tty, const unsigned char *buf,
804 int count)
805 {
806 struct sdio_uart_port *port = tty->driver_data;
807 int ret;
808
809 if (!port->func)
810 return -ENODEV;
811
812 ret = kfifo_in_locked(&port->xmit_fifo, buf, count, &port->write_lock);
813 if (!(port->ier & UART_IER_THRI)) {
814 int err = sdio_uart_claim_func(port);
815 if (!err) {
816 sdio_uart_start_tx(port);
817 sdio_uart_irq(port->func);
818 sdio_uart_release_func(port);
819 } else
820 ret = err;
821 }
822
823 return ret;
824 }
825
826 static int sdio_uart_write_room(struct tty_struct *tty)
827 {
828 struct sdio_uart_port *port = tty->driver_data;
829 return FIFO_SIZE - kfifo_len(&port->xmit_fifo);
830 }
831
832 static int sdio_uart_chars_in_buffer(struct tty_struct *tty)
833 {
834 struct sdio_uart_port *port = tty->driver_data;
835 return kfifo_len(&port->xmit_fifo);
836 }
837
838 static void sdio_uart_send_xchar(struct tty_struct *tty, char ch)
839 {
840 struct sdio_uart_port *port = tty->driver_data;
841
842 port->x_char = ch;
843 if (ch && !(port->ier & UART_IER_THRI)) {
844 if (sdio_uart_claim_func(port) != 0)
845 return;
846 sdio_uart_start_tx(port);
847 sdio_uart_irq(port->func);
848 sdio_uart_release_func(port);
849 }
850 }
851
852 static void sdio_uart_throttle(struct tty_struct *tty)
853 {
854 struct sdio_uart_port *port = tty->driver_data;
855
856 if (!I_IXOFF(tty) && !(tty->termios->c_cflag & CRTSCTS))
857 return;
858
859 if (sdio_uart_claim_func(port) != 0)
860 return;
861
862 if (I_IXOFF(tty)) {
863 port->x_char = STOP_CHAR(tty);
864 sdio_uart_start_tx(port);
865 }
866
867 if (tty->termios->c_cflag & CRTSCTS)
868 sdio_uart_clear_mctrl(port, TIOCM_RTS);
869
870 sdio_uart_irq(port->func);
871 sdio_uart_release_func(port);
872 }
873
874 static void sdio_uart_unthrottle(struct tty_struct *tty)
875 {
876 struct sdio_uart_port *port = tty->driver_data;
877
878 if (!I_IXOFF(tty) && !(tty->termios->c_cflag & CRTSCTS))
879 return;
880
881 if (sdio_uart_claim_func(port) != 0)
882 return;
883
884 if (I_IXOFF(tty)) {
885 if (port->x_char) {
886 port->x_char = 0;
887 } else {
888 port->x_char = START_CHAR(tty);
889 sdio_uart_start_tx(port);
890 }
891 }
892
893 if (tty->termios->c_cflag & CRTSCTS)
894 sdio_uart_set_mctrl(port, TIOCM_RTS);
895
896 sdio_uart_irq(port->func);
897 sdio_uart_release_func(port);
898 }
899
900 static void sdio_uart_set_termios(struct tty_struct *tty,
901 struct ktermios *old_termios)
902 {
903 struct sdio_uart_port *port = tty->driver_data;
904 unsigned int cflag = tty->termios->c_cflag;
905
906 if (sdio_uart_claim_func(port) != 0)
907 return;
908
909 sdio_uart_change_speed(port, tty->termios, old_termios);
910
911 /* Handle transition to B0 status */
912 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
913 sdio_uart_clear_mctrl(port, TIOCM_RTS | TIOCM_DTR);
914
915 /* Handle transition away from B0 status */
916 if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
917 unsigned int mask = TIOCM_DTR;
918 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
919 mask |= TIOCM_RTS;
920 sdio_uart_set_mctrl(port, mask);
921 }
922
923 /* Handle turning off CRTSCTS */
924 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
925 tty->hw_stopped = 0;
926 sdio_uart_start_tx(port);
927 }
928
929 /* Handle turning on CRTSCTS */
930 if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
931 if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS)) {
932 tty->hw_stopped = 1;
933 sdio_uart_stop_tx(port);
934 }
935 }
936
937 sdio_uart_release_func(port);
938 }
939
940 static int sdio_uart_break_ctl(struct tty_struct *tty, int break_state)
941 {
942 struct sdio_uart_port *port = tty->driver_data;
943 int result;
944
945 result = sdio_uart_claim_func(port);
946 if (result != 0)
947 return result;
948
949 if (break_state == -1)
950 port->lcr |= UART_LCR_SBC;
951 else
952 port->lcr &= ~UART_LCR_SBC;
953 sdio_out(port, UART_LCR, port->lcr);
954
955 sdio_uart_release_func(port);
956 return 0;
957 }
958
959 static int sdio_uart_tiocmget(struct tty_struct *tty)
960 {
961 struct sdio_uart_port *port = tty->driver_data;
962 int result;
963
964 result = sdio_uart_claim_func(port);
965 if (!result) {
966 result = port->mctrl | sdio_uart_get_mctrl(port);
967 sdio_uart_release_func(port);
968 }
969
970 return result;
971 }
972
973 static int sdio_uart_tiocmset(struct tty_struct *tty,
974 unsigned int set, unsigned int clear)
975 {
976 struct sdio_uart_port *port = tty->driver_data;
977 int result;
978
979 result = sdio_uart_claim_func(port);
980 if (!result) {
981 sdio_uart_update_mctrl(port, set, clear);
982 sdio_uart_release_func(port);
983 }
984
985 return result;
986 }
987
988 static int sdio_uart_proc_show(struct seq_file *m, void *v)
989 {
990 int i;
991
992 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
993 "", "", "");
994 for (i = 0; i < UART_NR; i++) {
995 struct sdio_uart_port *port = sdio_uart_port_get(i);
996 if (port) {
997 seq_printf(m, "%d: uart:SDIO", i);
998 if (capable(CAP_SYS_ADMIN)) {
999 seq_printf(m, " tx:%d rx:%d",
1000 port->icount.tx, port->icount.rx);
1001 if (port->icount.frame)
1002 seq_printf(m, " fe:%d",
1003 port->icount.frame);
1004 if (port->icount.parity)
1005 seq_printf(m, " pe:%d",
1006 port->icount.parity);
1007 if (port->icount.brk)
1008 seq_printf(m, " brk:%d",
1009 port->icount.brk);
1010 if (port->icount.overrun)
1011 seq_printf(m, " oe:%d",
1012 port->icount.overrun);
1013 if (port->icount.cts)
1014 seq_printf(m, " cts:%d",
1015 port->icount.cts);
1016 if (port->icount.dsr)
1017 seq_printf(m, " dsr:%d",
1018 port->icount.dsr);
1019 if (port->icount.rng)
1020 seq_printf(m, " rng:%d",
1021 port->icount.rng);
1022 if (port->icount.dcd)
1023 seq_printf(m, " dcd:%d",
1024 port->icount.dcd);
1025 }
1026 sdio_uart_port_put(port);
1027 seq_putc(m, '\n');
1028 }
1029 }
1030 return 0;
1031 }
1032
1033 static int sdio_uart_proc_open(struct inode *inode, struct file *file)
1034 {
1035 return single_open(file, sdio_uart_proc_show, NULL);
1036 }
1037
1038 static const struct file_operations sdio_uart_proc_fops = {
1039 .owner = THIS_MODULE,
1040 .open = sdio_uart_proc_open,
1041 .read = seq_read,
1042 .llseek = seq_lseek,
1043 .release = single_release,
1044 };
1045
1046 static const struct tty_port_operations sdio_uart_port_ops = {
1047 .dtr_rts = uart_dtr_rts,
1048 .carrier_raised = uart_carrier_raised,
1049 .shutdown = sdio_uart_shutdown,
1050 .activate = sdio_uart_activate,
1051 };
1052
1053 static const struct tty_operations sdio_uart_ops = {
1054 .open = sdio_uart_open,
1055 .close = sdio_uart_close,
1056 .write = sdio_uart_write,
1057 .write_room = sdio_uart_write_room,
1058 .chars_in_buffer = sdio_uart_chars_in_buffer,
1059 .send_xchar = sdio_uart_send_xchar,
1060 .throttle = sdio_uart_throttle,
1061 .unthrottle = sdio_uart_unthrottle,
1062 .set_termios = sdio_uart_set_termios,
1063 .hangup = sdio_uart_hangup,
1064 .break_ctl = sdio_uart_break_ctl,
1065 .tiocmget = sdio_uart_tiocmget,
1066 .tiocmset = sdio_uart_tiocmset,
1067 .install = sdio_uart_install,
1068 .cleanup = sdio_uart_cleanup,
1069 .proc_fops = &sdio_uart_proc_fops,
1070 };
1071
1072 static struct tty_driver *sdio_uart_tty_driver;
1073
1074 static int sdio_uart_probe(struct sdio_func *func,
1075 const struct sdio_device_id *id)
1076 {
1077 struct sdio_uart_port *port;
1078 int ret;
1079
1080 port = kzalloc(sizeof(struct sdio_uart_port), GFP_KERNEL);
1081 if (!port)
1082 return -ENOMEM;
1083
1084 if (func->class == SDIO_CLASS_UART) {
1085 pr_warning("%s: need info on UART class basic setup\n",
1086 sdio_func_id(func));
1087 kfree(port);
1088 return -ENOSYS;
1089 } else if (func->class == SDIO_CLASS_GPS) {
1090 /*
1091 * We need tuple 0x91. It contains SUBTPL_SIOREG
1092 * and SUBTPL_RCVCAPS.
1093 */
1094 struct sdio_func_tuple *tpl;
1095 for (tpl = func->tuples; tpl; tpl = tpl->next) {
1096 if (tpl->code != 0x91)
1097 continue;
1098 if (tpl->size < 10)
1099 continue;
1100 if (tpl->data[1] == 0) /* SUBTPL_SIOREG */
1101 break;
1102 }
1103 if (!tpl) {
1104 pr_warning(
1105 "%s: can't find tuple 0x91 subtuple 0 (SUBTPL_SIOREG) for GPS class\n",
1106 sdio_func_id(func));
1107 kfree(port);
1108 return -EINVAL;
1109 }
1110 pr_debug("%s: Register ID = 0x%02x, Exp ID = 0x%02x\n",
1111 sdio_func_id(func), tpl->data[2], tpl->data[3]);
1112 port->regs_offset = (tpl->data[4] << 0) |
1113 (tpl->data[5] << 8) |
1114 (tpl->data[6] << 16);
1115 pr_debug("%s: regs offset = 0x%x\n",
1116 sdio_func_id(func), port->regs_offset);
1117 port->uartclk = tpl->data[7] * 115200;
1118 if (port->uartclk == 0)
1119 port->uartclk = 115200;
1120 pr_debug("%s: clk %d baudcode %u 4800-div %u\n",
1121 sdio_func_id(func), port->uartclk,
1122 tpl->data[7], tpl->data[8] | (tpl->data[9] << 8));
1123 } else {
1124 kfree(port);
1125 return -EINVAL;
1126 }
1127
1128 port->func = func;
1129 sdio_set_drvdata(func, port);
1130 tty_port_init(&port->port);
1131 port->port.ops = &sdio_uart_port_ops;
1132
1133 ret = sdio_uart_add_port(port);
1134 if (ret) {
1135 kfree(port);
1136 } else {
1137 struct device *dev;
1138 dev = tty_register_device(sdio_uart_tty_driver,
1139 port->index, &func->dev);
1140 if (IS_ERR(dev)) {
1141 sdio_uart_port_remove(port);
1142 ret = PTR_ERR(dev);
1143 }
1144 }
1145
1146 return ret;
1147 }
1148
1149 static void sdio_uart_remove(struct sdio_func *func)
1150 {
1151 struct sdio_uart_port *port = sdio_get_drvdata(func);
1152
1153 tty_unregister_device(sdio_uart_tty_driver, port->index);
1154 sdio_uart_port_remove(port);
1155 }
1156
1157 static const struct sdio_device_id sdio_uart_ids[] = {
1158 { SDIO_DEVICE_CLASS(SDIO_CLASS_UART) },
1159 { SDIO_DEVICE_CLASS(SDIO_CLASS_GPS) },
1160 { /* end: all zeroes */ },
1161 };
1162
1163 MODULE_DEVICE_TABLE(sdio, sdio_uart_ids);
1164
1165 static struct sdio_driver sdio_uart_driver = {
1166 .probe = sdio_uart_probe,
1167 .remove = sdio_uart_remove,
1168 .name = "sdio_uart",
1169 .id_table = sdio_uart_ids,
1170 };
1171
1172 static int __init sdio_uart_init(void)
1173 {
1174 int ret;
1175 struct tty_driver *tty_drv;
1176
1177 sdio_uart_tty_driver = tty_drv = alloc_tty_driver(UART_NR);
1178 if (!tty_drv)
1179 return -ENOMEM;
1180
1181 tty_drv->owner = THIS_MODULE;
1182 tty_drv->driver_name = "sdio_uart";
1183 tty_drv->name = "ttySDIO";
1184 tty_drv->major = 0; /* dynamically allocated */
1185 tty_drv->minor_start = 0;
1186 tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
1187 tty_drv->subtype = SERIAL_TYPE_NORMAL;
1188 tty_drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1189 tty_drv->init_termios = tty_std_termios;
1190 tty_drv->init_termios.c_cflag = B4800 | CS8 | CREAD | HUPCL | CLOCAL;
1191 tty_drv->init_termios.c_ispeed = 4800;
1192 tty_drv->init_termios.c_ospeed = 4800;
1193 tty_set_operations(tty_drv, &sdio_uart_ops);
1194
1195 ret = tty_register_driver(tty_drv);
1196 if (ret)
1197 goto err1;
1198
1199 ret = sdio_register_driver(&sdio_uart_driver);
1200 if (ret)
1201 goto err2;
1202
1203 return 0;
1204
1205 err2:
1206 tty_unregister_driver(tty_drv);
1207 err1:
1208 put_tty_driver(tty_drv);
1209 return ret;
1210 }
1211
1212 static void __exit sdio_uart_exit(void)
1213 {
1214 sdio_unregister_driver(&sdio_uart_driver);
1215 tty_unregister_driver(sdio_uart_tty_driver);
1216 put_tty_driver(sdio_uart_tty_driver);
1217 }
1218
1219 module_init(sdio_uart_init);
1220 module_exit(sdio_uart_exit);
1221
1222 MODULE_AUTHOR("Nicolas Pitre");
1223 MODULE_LICENSE("GPL");