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MMC: sdio, use kref from tty_port
[linux/fpc-iii.git] / drivers / mmc / card / sdio_uart.c
blobbd57a11acc7949e7237be40a442c865c418c61a1
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 unsigned int index;
70 struct sdio_func *func;
71 struct mutex func_lock;
72 struct task_struct *in_sdio_uart_irq;
73 unsigned int regs_offset;
74 struct kfifo xmit_fifo;
75 spinlock_t write_lock;
76 struct uart_icount icount;
77 unsigned int uartclk;
78 unsigned int mctrl;
79 unsigned int rx_mctrl;
80 unsigned int read_status_mask;
81 unsigned int ignore_status_mask;
82 unsigned char x_char;
83 unsigned char ier;
84 unsigned char lcr;
85 };
86
87 static struct sdio_uart_port *sdio_uart_table[UART_NR];
88 static DEFINE_SPINLOCK(sdio_uart_table_lock);
89
90 static int sdio_uart_add_port(struct sdio_uart_port *port)
91 {
92 int index, ret = -EBUSY;
93
94 mutex_init(&port->func_lock);
95 spin_lock_init(&port->write_lock);
96 if (kfifo_alloc(&port->xmit_fifo, FIFO_SIZE, GFP_KERNEL))
97 return -ENOMEM;
98
99 spin_lock(&sdio_uart_table_lock);
100 for (index = 0; index < UART_NR; index++) {
101 if (!sdio_uart_table[index]) {
102 port->index = index;
103 sdio_uart_table[index] = port;
104 ret = 0;
105 break;
106 }
107 }
108 spin_unlock(&sdio_uart_table_lock);
109
110 return ret;
111 }
112
113 static struct sdio_uart_port *sdio_uart_port_get(unsigned index)
114 {
115 struct sdio_uart_port *port;
116
117 if (index >= UART_NR)
118 return NULL;
119
120 spin_lock(&sdio_uart_table_lock);
121 port = sdio_uart_table[index];
122 if (port)
123 tty_port_get(&port->port);
124 spin_unlock(&sdio_uart_table_lock);
125
126 return port;
127 }
128
129 static void sdio_uart_port_put(struct sdio_uart_port *port)
130 {
131 tty_port_put(&port->port);
132 }
133
134 static void sdio_uart_port_remove(struct sdio_uart_port *port)
135 {
136 struct sdio_func *func;
137 struct tty_struct *tty;
138
139 BUG_ON(sdio_uart_table[port->index] != port);
140
141 spin_lock(&sdio_uart_table_lock);
142 sdio_uart_table[port->index] = NULL;
143 spin_unlock(&sdio_uart_table_lock);
144
145 /*
146 * We're killing a port that potentially still is in use by
147 * the tty layer. Be careful to prevent any further access
148 * to the SDIO function and arrange for the tty layer to
149 * give up on that port ASAP.
150 * Beware: the lock ordering is critical.
151 */
152 mutex_lock(&port->port.mutex);
153 mutex_lock(&port->func_lock);
154 func = port->func;
155 sdio_claim_host(func);
156 port->func = NULL;
157 mutex_unlock(&port->func_lock);
158 tty = tty_port_tty_get(&port->port);
159 /* tty_hangup is async so is this safe as is ?? */
160 if (tty) {
161 tty_hangup(tty);
162 tty_kref_put(tty);
163 }
164 mutex_unlock(&port->port.mutex);
165 sdio_release_irq(func);
166 sdio_disable_func(func);
167 sdio_release_host(func);
168
169 sdio_uart_port_put(port);
170 }
171
172 static int sdio_uart_claim_func(struct sdio_uart_port *port)
173 {
174 mutex_lock(&port->func_lock);
175 if (unlikely(!port->func)) {
176 mutex_unlock(&port->func_lock);
177 return -ENODEV;
178 }
179 if (likely(port->in_sdio_uart_irq != current))
180 sdio_claim_host(port->func);
181 mutex_unlock(&port->func_lock);
182 return 0;
183 }
184
185 static inline void sdio_uart_release_func(struct sdio_uart_port *port)
186 {
187 if (likely(port->in_sdio_uart_irq != current))
188 sdio_release_host(port->func);
189 }
190
191 static inline unsigned int sdio_in(struct sdio_uart_port *port, int offset)
192 {
193 unsigned char c;
194 c = sdio_readb(port->func, port->regs_offset + offset, NULL);
195 return c;
196 }
197
198 static inline void sdio_out(struct sdio_uart_port *port, int offset, int value)
199 {
200 sdio_writeb(port->func, value, port->regs_offset + offset, NULL);
201 }
202
203 static unsigned int sdio_uart_get_mctrl(struct sdio_uart_port *port)
204 {
205 unsigned char status;
206 unsigned int ret;
207
208 /* FIXME: What stops this losing the delta bits and breaking
209 sdio_uart_check_modem_status ? */
210 status = sdio_in(port, UART_MSR);
211
212 ret = 0;
213 if (status & UART_MSR_DCD)
214 ret |= TIOCM_CAR;
215 if (status & UART_MSR_RI)
216 ret |= TIOCM_RNG;
217 if (status & UART_MSR_DSR)
218 ret |= TIOCM_DSR;
219 if (status & UART_MSR_CTS)
220 ret |= TIOCM_CTS;
221 return ret;
222 }
223
224 static void sdio_uart_write_mctrl(struct sdio_uart_port *port,
225 unsigned int mctrl)
226 {
227 unsigned char mcr = 0;
228
229 if (mctrl & TIOCM_RTS)
230 mcr |= UART_MCR_RTS;
231 if (mctrl & TIOCM_DTR)
232 mcr |= UART_MCR_DTR;
233 if (mctrl & TIOCM_OUT1)
234 mcr |= UART_MCR_OUT1;
235 if (mctrl & TIOCM_OUT2)
236 mcr |= UART_MCR_OUT2;
237 if (mctrl & TIOCM_LOOP)
238 mcr |= UART_MCR_LOOP;
239
240 sdio_out(port, UART_MCR, mcr);
241 }
242
243 static inline void sdio_uart_update_mctrl(struct sdio_uart_port *port,
244 unsigned int set, unsigned int clear)
245 {
246 unsigned int old;
247
248 old = port->mctrl;
249 port->mctrl = (old & ~clear) | set;
250 if (old != port->mctrl)
251 sdio_uart_write_mctrl(port, port->mctrl);
252 }
253
254 #define sdio_uart_set_mctrl(port, x) sdio_uart_update_mctrl(port, x, 0)
255 #define sdio_uart_clear_mctrl(port, x) sdio_uart_update_mctrl(port, 0, x)
256
257 static void sdio_uart_change_speed(struct sdio_uart_port *port,
258 struct ktermios *termios,
259 struct ktermios *old)
260 {
261 unsigned char cval, fcr = 0;
262 unsigned int baud, quot;
263
264 switch (termios->c_cflag & CSIZE) {
265 case CS5:
266 cval = UART_LCR_WLEN5;
267 break;
268 case CS6:
269 cval = UART_LCR_WLEN6;
270 break;
271 case CS7:
272 cval = UART_LCR_WLEN7;
273 break;
274 default:
275 case CS8:
276 cval = UART_LCR_WLEN8;
277 break;
278 }
279
280 if (termios->c_cflag & CSTOPB)
281 cval |= UART_LCR_STOP;
282 if (termios->c_cflag & PARENB)
283 cval |= UART_LCR_PARITY;
284 if (!(termios->c_cflag & PARODD))
285 cval |= UART_LCR_EPAR;
286
287 for (;;) {
288 baud = tty_termios_baud_rate(termios);
289 if (baud == 0)
290 baud = 9600; /* Special case: B0 rate. */
291 if (baud <= port->uartclk)
292 break;
293 /*
294 * Oops, the quotient was zero. Try again with the old
295 * baud rate if possible, otherwise default to 9600.
296 */
297 termios->c_cflag &= ~CBAUD;
298 if (old) {
299 termios->c_cflag |= old->c_cflag & CBAUD;
300 old = NULL;
301 } else
302 termios->c_cflag |= B9600;
303 }
304 quot = (2 * port->uartclk + baud) / (2 * baud);
305
306 if (baud < 2400)
307 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
308 else
309 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10;
310
311 port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
312 if (termios->c_iflag & INPCK)
313 port->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
314 if (termios->c_iflag & (BRKINT | PARMRK))
315 port->read_status_mask |= UART_LSR_BI;
316
317 /*
318 * Characters to ignore
319 */
320 port->ignore_status_mask = 0;
321 if (termios->c_iflag & IGNPAR)
322 port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
323 if (termios->c_iflag & IGNBRK) {
324 port->ignore_status_mask |= UART_LSR_BI;
325 /*
326 * If we're ignoring parity and break indicators,
327 * ignore overruns too (for real raw support).
328 */
329 if (termios->c_iflag & IGNPAR)
330 port->ignore_status_mask |= UART_LSR_OE;
331 }
332
333 /*
334 * ignore all characters if CREAD is not set
335 */
336 if ((termios->c_cflag & CREAD) == 0)
337 port->ignore_status_mask |= UART_LSR_DR;
338
339 /*
340 * CTS flow control flag and modem status interrupts
341 */
342 port->ier &= ~UART_IER_MSI;
343 if ((termios->c_cflag & CRTSCTS) || !(termios->c_cflag & CLOCAL))
344 port->ier |= UART_IER_MSI;
345
346 port->lcr = cval;
347
348 sdio_out(port, UART_IER, port->ier);
349 sdio_out(port, UART_LCR, cval | UART_LCR_DLAB);
350 sdio_out(port, UART_DLL, quot & 0xff);
351 sdio_out(port, UART_DLM, quot >> 8);
352 sdio_out(port, UART_LCR, cval);
353 sdio_out(port, UART_FCR, fcr);
354
355 sdio_uart_write_mctrl(port, port->mctrl);
356 }
357
358 static void sdio_uart_start_tx(struct sdio_uart_port *port)
359 {
360 if (!(port->ier & UART_IER_THRI)) {
361 port->ier |= UART_IER_THRI;
362 sdio_out(port, UART_IER, port->ier);
363 }
364 }
365
366 static void sdio_uart_stop_tx(struct sdio_uart_port *port)
367 {
368 if (port->ier & UART_IER_THRI) {
369 port->ier &= ~UART_IER_THRI;
370 sdio_out(port, UART_IER, port->ier);
371 }
372 }
373
374 static void sdio_uart_stop_rx(struct sdio_uart_port *port)
375 {
376 port->ier &= ~UART_IER_RLSI;
377 port->read_status_mask &= ~UART_LSR_DR;
378 sdio_out(port, UART_IER, port->ier);
379 }
380
381 static void sdio_uart_receive_chars(struct sdio_uart_port *port,
382 unsigned int *status)
383 {
384 struct tty_struct *tty = tty_port_tty_get(&port->port);
385 unsigned int ch, flag;
386 int max_count = 256;
387
388 do {
389 ch = sdio_in(port, UART_RX);
390 flag = TTY_NORMAL;
391 port->icount.rx++;
392
393 if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
394 UART_LSR_FE | UART_LSR_OE))) {
395 /*
396 * For statistics only
397 */
398 if (*status & UART_LSR_BI) {
399 *status &= ~(UART_LSR_FE | UART_LSR_PE);
400 port->icount.brk++;
401 } else if (*status & UART_LSR_PE)
402 port->icount.parity++;
403 else if (*status & UART_LSR_FE)
404 port->icount.frame++;
405 if (*status & UART_LSR_OE)
406 port->icount.overrun++;
407
408 /*
409 * Mask off conditions which should be ignored.
410 */
411 *status &= port->read_status_mask;
412 if (*status & UART_LSR_BI)
413 flag = TTY_BREAK;
414 else if (*status & UART_LSR_PE)
415 flag = TTY_PARITY;
416 else if (*status & UART_LSR_FE)
417 flag = TTY_FRAME;
418 }
419
420 if ((*status & port->ignore_status_mask & ~UART_LSR_OE) == 0)
421 if (tty)
422 tty_insert_flip_char(tty, ch, flag);
423
424 /*
425 * Overrun is special. Since it's reported immediately,
426 * it doesn't affect the current character.
427 */
428 if (*status & ~port->ignore_status_mask & UART_LSR_OE)
429 if (tty)
430 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
431
432 *status = sdio_in(port, UART_LSR);
433 } while ((*status & UART_LSR_DR) && (max_count-- > 0));
434 if (tty) {
435 tty_flip_buffer_push(tty);
436 tty_kref_put(tty);
437 }
438 }
439
440 static void sdio_uart_transmit_chars(struct sdio_uart_port *port)
441 {
442 struct kfifo *xmit = &port->xmit_fifo;
443 int count;
444 struct tty_struct *tty;
445 u8 iobuf[16];
446 int len;
447
448 if (port->x_char) {
449 sdio_out(port, UART_TX, port->x_char);
450 port->icount.tx++;
451 port->x_char = 0;
452 return;
453 }
454
455 tty = tty_port_tty_get(&port->port);
456
457 if (tty == NULL || !kfifo_len(xmit) ||
458 tty->stopped || tty->hw_stopped) {
459 sdio_uart_stop_tx(port);
460 tty_kref_put(tty);
461 return;
462 }
463
464 len = kfifo_out_locked(xmit, iobuf, 16, &port->write_lock);
465 for (count = 0; count < len; count++) {
466 sdio_out(port, UART_TX, iobuf[count]);
467 port->icount.tx++;
468 }
469
470 len = kfifo_len(xmit);
471 if (len < WAKEUP_CHARS) {
472 tty_wakeup(tty);
473 if (len == 0)
474 sdio_uart_stop_tx(port);
475 }
476 tty_kref_put(tty);
477 }
478
479 static void sdio_uart_check_modem_status(struct sdio_uart_port *port)
480 {
481 int status;
482 struct tty_struct *tty;
483
484 status = sdio_in(port, UART_MSR);
485
486 if ((status & UART_MSR_ANY_DELTA) == 0)
487 return;
488
489 if (status & UART_MSR_TERI)
490 port->icount.rng++;
491 if (status & UART_MSR_DDSR)
492 port->icount.dsr++;
493 if (status & UART_MSR_DDCD) {
494 port->icount.dcd++;
495 /* DCD raise - wake for open */
496 if (status & UART_MSR_DCD)
497 wake_up_interruptible(&port->port.open_wait);
498 else {
499 /* DCD drop - hang up if tty attached */
500 tty = tty_port_tty_get(&port->port);
501 if (tty) {
502 tty_hangup(tty);
503 tty_kref_put(tty);
504 }
505 }
506 }
507 if (status & UART_MSR_DCTS) {
508 port->icount.cts++;
509 tty = tty_port_tty_get(&port->port);
510 if (tty && (tty->termios.c_cflag & CRTSCTS)) {
511 int cts = (status & UART_MSR_CTS);
512 if (tty->hw_stopped) {
513 if (cts) {
514 tty->hw_stopped = 0;
515 sdio_uart_start_tx(port);
516 tty_wakeup(tty);
517 }
518 } else {
519 if (!cts) {
520 tty->hw_stopped = 1;
521 sdio_uart_stop_tx(port);
522 }
523 }
524 }
525 tty_kref_put(tty);
526 }
527 }
528
529 /*
530 * This handles the interrupt from one port.
531 */
532 static void sdio_uart_irq(struct sdio_func *func)
533 {
534 struct sdio_uart_port *port = sdio_get_drvdata(func);
535 unsigned int iir, lsr;
536
537 /*
538 * In a few places sdio_uart_irq() is called directly instead of
539 * waiting for the actual interrupt to be raised and the SDIO IRQ
540 * thread scheduled in order to reduce latency. However, some
541 * interaction with the tty core may end up calling us back
542 * (serial echo, flow control, etc.) through those same places
543 * causing undesirable effects. Let's stop the recursion here.
544 */
545 if (unlikely(port->in_sdio_uart_irq == current))
546 return;
547
548 iir = sdio_in(port, UART_IIR);
549 if (iir & UART_IIR_NO_INT)
550 return;
551
552 port->in_sdio_uart_irq = current;
553 lsr = sdio_in(port, UART_LSR);
554 if (lsr & UART_LSR_DR)
555 sdio_uart_receive_chars(port, &lsr);
556 sdio_uart_check_modem_status(port);
557 if (lsr & UART_LSR_THRE)
558 sdio_uart_transmit_chars(port);
559 port->in_sdio_uart_irq = NULL;
560 }
561
562 static int uart_carrier_raised(struct tty_port *tport)
563 {
564 struct sdio_uart_port *port =
565 container_of(tport, struct sdio_uart_port, port);
566 unsigned int ret = sdio_uart_claim_func(port);
567 if (ret) /* Missing hardware shouldn't block for carrier */
568 return 1;
569 ret = sdio_uart_get_mctrl(port);
570 sdio_uart_release_func(port);
571 if (ret & TIOCM_CAR)
572 return 1;
573 return 0;
574 }
575
576 /**
577 * uart_dtr_rts - port helper to set uart signals
578 * @tport: tty port to be updated
579 * @onoff: set to turn on DTR/RTS
580 *
581 * Called by the tty port helpers when the modem signals need to be
582 * adjusted during an open, close and hangup.
583 */
584
585 static void uart_dtr_rts(struct tty_port *tport, int onoff)
586 {
587 struct sdio_uart_port *port =
588 container_of(tport, struct sdio_uart_port, port);
589 int ret = sdio_uart_claim_func(port);
590 if (ret)
591 return;
592 if (onoff == 0)
593 sdio_uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
594 else
595 sdio_uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
596 sdio_uart_release_func(port);
597 }
598
599 /**
600 * sdio_uart_activate - start up hardware
601 * @tport: tty port to activate
602 * @tty: tty bound to this port
603 *
604 * Activate a tty port. The port locking guarantees us this will be
605 * run exactly once per set of opens, and if successful will see the
606 * shutdown method run exactly once to match. Start up and shutdown are
607 * protected from each other by the internal locking and will not run
608 * at the same time even during a hangup event.
609 *
610 * If we successfully start up the port we take an extra kref as we
611 * will keep it around until shutdown when the kref is dropped.
612 */
613
614 static int sdio_uart_activate(struct tty_port *tport, struct tty_struct *tty)
615 {
616 struct sdio_uart_port *port =
617 container_of(tport, struct sdio_uart_port, port);
618 int ret;
619
620 /*
621 * Set the TTY IO error marker - we will only clear this
622 * once we have successfully opened the port.
623 */
624 set_bit(TTY_IO_ERROR, &tty->flags);
625
626 kfifo_reset(&port->xmit_fifo);
627
628 ret = sdio_uart_claim_func(port);
629 if (ret)
630 return ret;
631 ret = sdio_enable_func(port->func);
632 if (ret)
633 goto err1;
634 ret = sdio_claim_irq(port->func, sdio_uart_irq);
635 if (ret)
636 goto err2;
637
638 /*
639 * Clear the FIFO buffers and disable them.
640 * (they will be reenabled in sdio_change_speed())
641 */
642 sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO);
643 sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO |
644 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
645 sdio_out(port, UART_FCR, 0);
646
647 /*
648 * Clear the interrupt registers.
649 */
650 (void) sdio_in(port, UART_LSR);
651 (void) sdio_in(port, UART_RX);
652 (void) sdio_in(port, UART_IIR);
653 (void) sdio_in(port, UART_MSR);
654
655 /*
656 * Now, initialize the UART
657 */
658 sdio_out(port, UART_LCR, UART_LCR_WLEN8);
659
660 port->ier = UART_IER_RLSI|UART_IER_RDI|UART_IER_RTOIE|UART_IER_UUE;
661 port->mctrl = TIOCM_OUT2;
662
663 sdio_uart_change_speed(port, &tty->termios, NULL);
664
665 if (tty->termios.c_cflag & CBAUD)
666 sdio_uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
667
668 if (tty->termios.c_cflag & CRTSCTS)
669 if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS))
670 tty->hw_stopped = 1;
671
672 clear_bit(TTY_IO_ERROR, &tty->flags);
673
674 /* Kick the IRQ handler once while we're still holding the host lock */
675 sdio_uart_irq(port->func);
676
677 sdio_uart_release_func(port);
678 return 0;
679
680 err2:
681 sdio_disable_func(port->func);
682 err1:
683 sdio_uart_release_func(port);
684 return ret;
685 }
686
687 /**
688 * sdio_uart_shutdown - stop hardware
689 * @tport: tty port to shut down
690 *
691 * Deactivate a tty port. The port locking guarantees us this will be
692 * run only if a successful matching activate already ran. The two are
693 * protected from each other by the internal locking and will not run
694 * at the same time even during a hangup event.
695 */
696
697 static void sdio_uart_shutdown(struct tty_port *tport)
698 {
699 struct sdio_uart_port *port =
700 container_of(tport, struct sdio_uart_port, port);
701 int ret;
702
703 ret = sdio_uart_claim_func(port);
704 if (ret)
705 return;
706
707 sdio_uart_stop_rx(port);
708
709 /* Disable interrupts from this port */
710 sdio_release_irq(port->func);
711 port->ier = 0;
712 sdio_out(port, UART_IER, 0);
713
714 sdio_uart_clear_mctrl(port, TIOCM_OUT2);
715
716 /* Disable break condition and FIFOs. */
717 port->lcr &= ~UART_LCR_SBC;
718 sdio_out(port, UART_LCR, port->lcr);
719 sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO |
720 UART_FCR_CLEAR_RCVR |
721 UART_FCR_CLEAR_XMIT);
722 sdio_out(port, UART_FCR, 0);
723
724 sdio_disable_func(port->func);
725
726 sdio_uart_release_func(port);
727 }
728
729 static void sdio_uart_port_destroy(struct tty_port *tport)
730 {
731 struct sdio_uart_port *port =
732 container_of(tport, struct sdio_uart_port, port);
733 kfifo_free(&port->xmit_fifo);
734 kfree(port);
735 }
736
737 /**
738 * sdio_uart_install - install method
739 * @driver: the driver in use (sdio_uart in our case)
740 * @tty: the tty being bound
741 *
742 * Look up and bind the tty and the driver together. Initialize
743 * any needed private data (in our case the termios)
744 */
745
746 static int sdio_uart_install(struct tty_driver *driver, struct tty_struct *tty)
747 {
748 int idx = tty->index;
749 struct sdio_uart_port *port = sdio_uart_port_get(idx);
750 int ret = tty_standard_install(driver, tty);
751
752 if (ret == 0)
753 /* This is the ref sdio_uart_port get provided */
754 tty->driver_data = port;
755 else
756 sdio_uart_port_put(port);
757 return ret;
758 }
759
760 /**
761 * sdio_uart_cleanup - called on the last tty kref drop
762 * @tty: the tty being destroyed
763 *
764 * Called asynchronously when the last reference to the tty is dropped.
765 * We cannot destroy the tty->driver_data port kref until this point
766 */
767
768 static void sdio_uart_cleanup(struct tty_struct *tty)
769 {
770 struct sdio_uart_port *port = tty->driver_data;
771 tty->driver_data = NULL; /* Bug trap */
772 sdio_uart_port_put(port);
773 }
774
775 /*
776 * Open/close/hangup is now entirely boilerplate
777 */
778
779 static int sdio_uart_open(struct tty_struct *tty, struct file *filp)
780 {
781 struct sdio_uart_port *port = tty->driver_data;
782 return tty_port_open(&port->port, tty, filp);
783 }
784
785 static void sdio_uart_close(struct tty_struct *tty, struct file * filp)
786 {
787 struct sdio_uart_port *port = tty->driver_data;
788 tty_port_close(&port->port, tty, filp);
789 }
790
791 static void sdio_uart_hangup(struct tty_struct *tty)
792 {
793 struct sdio_uart_port *port = tty->driver_data;
794 tty_port_hangup(&port->port);
795 }
796
797 static int sdio_uart_write(struct tty_struct *tty, const unsigned char *buf,
798 int count)
799 {
800 struct sdio_uart_port *port = tty->driver_data;
801 int ret;
802
803 if (!port->func)
804 return -ENODEV;
805
806 ret = kfifo_in_locked(&port->xmit_fifo, buf, count, &port->write_lock);
807 if (!(port->ier & UART_IER_THRI)) {
808 int err = sdio_uart_claim_func(port);
809 if (!err) {
810 sdio_uart_start_tx(port);
811 sdio_uart_irq(port->func);
812 sdio_uart_release_func(port);
813 } else
814 ret = err;
815 }
816
817 return ret;
818 }
819
820 static int sdio_uart_write_room(struct tty_struct *tty)
821 {
822 struct sdio_uart_port *port = tty->driver_data;
823 return FIFO_SIZE - kfifo_len(&port->xmit_fifo);
824 }
825
826 static int sdio_uart_chars_in_buffer(struct tty_struct *tty)
827 {
828 struct sdio_uart_port *port = tty->driver_data;
829 return kfifo_len(&port->xmit_fifo);
830 }
831
832 static void sdio_uart_send_xchar(struct tty_struct *tty, char ch)
833 {
834 struct sdio_uart_port *port = tty->driver_data;
835
836 port->x_char = ch;
837 if (ch && !(port->ier & UART_IER_THRI)) {
838 if (sdio_uart_claim_func(port) != 0)
839 return;
840 sdio_uart_start_tx(port);
841 sdio_uart_irq(port->func);
842 sdio_uart_release_func(port);
843 }
844 }
845
846 static void sdio_uart_throttle(struct tty_struct *tty)
847 {
848 struct sdio_uart_port *port = tty->driver_data;
849
850 if (!I_IXOFF(tty) && !(tty->termios.c_cflag & CRTSCTS))
851 return;
852
853 if (sdio_uart_claim_func(port) != 0)
854 return;
855
856 if (I_IXOFF(tty)) {
857 port->x_char = STOP_CHAR(tty);
858 sdio_uart_start_tx(port);
859 }
860
861 if (tty->termios.c_cflag & CRTSCTS)
862 sdio_uart_clear_mctrl(port, TIOCM_RTS);
863
864 sdio_uart_irq(port->func);
865 sdio_uart_release_func(port);
866 }
867
868 static void sdio_uart_unthrottle(struct tty_struct *tty)
869 {
870 struct sdio_uart_port *port = tty->driver_data;
871
872 if (!I_IXOFF(tty) && !(tty->termios.c_cflag & CRTSCTS))
873 return;
874
875 if (sdio_uart_claim_func(port) != 0)
876 return;
877
878 if (I_IXOFF(tty)) {
879 if (port->x_char) {
880 port->x_char = 0;
881 } else {
882 port->x_char = START_CHAR(tty);
883 sdio_uart_start_tx(port);
884 }
885 }
886
887 if (tty->termios.c_cflag & CRTSCTS)
888 sdio_uart_set_mctrl(port, TIOCM_RTS);
889
890 sdio_uart_irq(port->func);
891 sdio_uart_release_func(port);
892 }
893
894 static void sdio_uart_set_termios(struct tty_struct *tty,
895 struct ktermios *old_termios)
896 {
897 struct sdio_uart_port *port = tty->driver_data;
898 unsigned int cflag = tty->termios.c_cflag;
899
900 if (sdio_uart_claim_func(port) != 0)
901 return;
902
903 sdio_uart_change_speed(port, &tty->termios, old_termios);
904
905 /* Handle transition to B0 status */
906 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
907 sdio_uart_clear_mctrl(port, TIOCM_RTS | TIOCM_DTR);
908
909 /* Handle transition away from B0 status */
910 if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
911 unsigned int mask = TIOCM_DTR;
912 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
913 mask |= TIOCM_RTS;
914 sdio_uart_set_mctrl(port, mask);
915 }
916
917 /* Handle turning off CRTSCTS */
918 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
919 tty->hw_stopped = 0;
920 sdio_uart_start_tx(port);
921 }
922
923 /* Handle turning on CRTSCTS */
924 if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
925 if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS)) {
926 tty->hw_stopped = 1;
927 sdio_uart_stop_tx(port);
928 }
929 }
930
931 sdio_uart_release_func(port);
932 }
933
934 static int sdio_uart_break_ctl(struct tty_struct *tty, int break_state)
935 {
936 struct sdio_uart_port *port = tty->driver_data;
937 int result;
938
939 result = sdio_uart_claim_func(port);
940 if (result != 0)
941 return result;
942
943 if (break_state == -1)
944 port->lcr |= UART_LCR_SBC;
945 else
946 port->lcr &= ~UART_LCR_SBC;
947 sdio_out(port, UART_LCR, port->lcr);
948
949 sdio_uart_release_func(port);
950 return 0;
951 }
952
953 static int sdio_uart_tiocmget(struct tty_struct *tty)
954 {
955 struct sdio_uart_port *port = tty->driver_data;
956 int result;
957
958 result = sdio_uart_claim_func(port);
959 if (!result) {
960 result = port->mctrl | sdio_uart_get_mctrl(port);
961 sdio_uart_release_func(port);
962 }
963
964 return result;
965 }
966
967 static int sdio_uart_tiocmset(struct tty_struct *tty,
968 unsigned int set, unsigned int clear)
969 {
970 struct sdio_uart_port *port = tty->driver_data;
971 int result;
972
973 result = sdio_uart_claim_func(port);
974 if (!result) {
975 sdio_uart_update_mctrl(port, set, clear);
976 sdio_uart_release_func(port);
977 }
978
979 return result;
980 }
981
982 static int sdio_uart_proc_show(struct seq_file *m, void *v)
983 {
984 int i;
985
986 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
987 "", "", "");
988 for (i = 0; i < UART_NR; i++) {
989 struct sdio_uart_port *port = sdio_uart_port_get(i);
990 if (port) {
991 seq_printf(m, "%d: uart:SDIO", i);
992 if (capable(CAP_SYS_ADMIN)) {
993 seq_printf(m, " tx:%d rx:%d",
994 port->icount.tx, port->icount.rx);
995 if (port->icount.frame)
996 seq_printf(m, " fe:%d",
997 port->icount.frame);
998 if (port->icount.parity)
999 seq_printf(m, " pe:%d",
1000 port->icount.parity);
1001 if (port->icount.brk)
1002 seq_printf(m, " brk:%d",
1003 port->icount.brk);
1004 if (port->icount.overrun)
1005 seq_printf(m, " oe:%d",
1006 port->icount.overrun);
1007 if (port->icount.cts)
1008 seq_printf(m, " cts:%d",
1009 port->icount.cts);
1010 if (port->icount.dsr)
1011 seq_printf(m, " dsr:%d",
1012 port->icount.dsr);
1013 if (port->icount.rng)
1014 seq_printf(m, " rng:%d",
1015 port->icount.rng);
1016 if (port->icount.dcd)
1017 seq_printf(m, " dcd:%d",
1018 port->icount.dcd);
1019 }
1020 sdio_uart_port_put(port);
1021 seq_putc(m, '\n');
1022 }
1023 }
1024 return 0;
1025 }
1026
1027 static int sdio_uart_proc_open(struct inode *inode, struct file *file)
1028 {
1029 return single_open(file, sdio_uart_proc_show, NULL);
1030 }
1031
1032 static const struct file_operations sdio_uart_proc_fops = {
1033 .owner = THIS_MODULE,
1034 .open = sdio_uart_proc_open,
1035 .read = seq_read,
1036 .llseek = seq_lseek,
1037 .release = single_release,
1038 };
1039
1040 static const struct tty_port_operations sdio_uart_port_ops = {
1041 .dtr_rts = uart_dtr_rts,
1042 .carrier_raised = uart_carrier_raised,
1043 .shutdown = sdio_uart_shutdown,
1044 .activate = sdio_uart_activate,
1045 .destruct = sdio_uart_port_destroy,
1046 };
1047
1048 static const struct tty_operations sdio_uart_ops = {
1049 .open = sdio_uart_open,
1050 .close = sdio_uart_close,
1051 .write = sdio_uart_write,
1052 .write_room = sdio_uart_write_room,
1053 .chars_in_buffer = sdio_uart_chars_in_buffer,
1054 .send_xchar = sdio_uart_send_xchar,
1055 .throttle = sdio_uart_throttle,
1056 .unthrottle = sdio_uart_unthrottle,
1057 .set_termios = sdio_uart_set_termios,
1058 .hangup = sdio_uart_hangup,
1059 .break_ctl = sdio_uart_break_ctl,
1060 .tiocmget = sdio_uart_tiocmget,
1061 .tiocmset = sdio_uart_tiocmset,
1062 .install = sdio_uart_install,
1063 .cleanup = sdio_uart_cleanup,
1064 .proc_fops = &sdio_uart_proc_fops,
1065 };
1066
1067 static struct tty_driver *sdio_uart_tty_driver;
1068
1069 static int sdio_uart_probe(struct sdio_func *func,
1070 const struct sdio_device_id *id)
1071 {
1072 struct sdio_uart_port *port;
1073 int ret;
1074
1075 port = kzalloc(sizeof(struct sdio_uart_port), GFP_KERNEL);
1076 if (!port)
1077 return -ENOMEM;
1078
1079 if (func->class == SDIO_CLASS_UART) {
1080 pr_warning("%s: need info on UART class basic setup\n",
1081 sdio_func_id(func));
1082 kfree(port);
1083 return -ENOSYS;
1084 } else if (func->class == SDIO_CLASS_GPS) {
1085 /*
1086 * We need tuple 0x91. It contains SUBTPL_SIOREG
1087 * and SUBTPL_RCVCAPS.
1088 */
1089 struct sdio_func_tuple *tpl;
1090 for (tpl = func->tuples; tpl; tpl = tpl->next) {
1091 if (tpl->code != 0x91)
1092 continue;
1093 if (tpl->size < 10)
1094 continue;
1095 if (tpl->data[1] == 0) /* SUBTPL_SIOREG */
1096 break;
1097 }
1098 if (!tpl) {
1099 pr_warning(
1100 "%s: can't find tuple 0x91 subtuple 0 (SUBTPL_SIOREG) for GPS class\n",
1101 sdio_func_id(func));
1102 kfree(port);
1103 return -EINVAL;
1104 }
1105 pr_debug("%s: Register ID = 0x%02x, Exp ID = 0x%02x\n",
1106 sdio_func_id(func), tpl->data[2], tpl->data[3]);
1107 port->regs_offset = (tpl->data[4] << 0) |
1108 (tpl->data[5] << 8) |
1109 (tpl->data[6] << 16);
1110 pr_debug("%s: regs offset = 0x%x\n",
1111 sdio_func_id(func), port->regs_offset);
1112 port->uartclk = tpl->data[7] * 115200;
1113 if (port->uartclk == 0)
1114 port->uartclk = 115200;
1115 pr_debug("%s: clk %d baudcode %u 4800-div %u\n",
1116 sdio_func_id(func), port->uartclk,
1117 tpl->data[7], tpl->data[8] | (tpl->data[9] << 8));
1118 } else {
1119 kfree(port);
1120 return -EINVAL;
1121 }
1122
1123 port->func = func;
1124 sdio_set_drvdata(func, port);
1125 tty_port_init(&port->port);
1126 port->port.ops = &sdio_uart_port_ops;
1127
1128 ret = sdio_uart_add_port(port);
1129 if (ret) {
1130 kfree(port);
1131 } else {
1132 struct device *dev;
1133 dev = tty_port_register_device(&port->port,
1134 sdio_uart_tty_driver, port->index, &func->dev);
1135 if (IS_ERR(dev)) {
1136 sdio_uart_port_remove(port);
1137 ret = PTR_ERR(dev);
1138 }
1139 }
1140
1141 return ret;
1142 }
1143
1144 static void sdio_uart_remove(struct sdio_func *func)
1145 {
1146 struct sdio_uart_port *port = sdio_get_drvdata(func);
1147
1148 tty_unregister_device(sdio_uart_tty_driver, port->index);
1149 sdio_uart_port_remove(port);
1150 }
1151
1152 static const struct sdio_device_id sdio_uart_ids[] = {
1153 { SDIO_DEVICE_CLASS(SDIO_CLASS_UART) },
1154 { SDIO_DEVICE_CLASS(SDIO_CLASS_GPS) },
1155 { /* end: all zeroes */ },
1156 };
1157
1158 MODULE_DEVICE_TABLE(sdio, sdio_uart_ids);
1159
1160 static struct sdio_driver sdio_uart_driver = {
1161 .probe = sdio_uart_probe,
1162 .remove = sdio_uart_remove,
1163 .name = "sdio_uart",
1164 .id_table = sdio_uart_ids,
1165 };
1166
1167 static int __init sdio_uart_init(void)
1168 {
1169 int ret;
1170 struct tty_driver *tty_drv;
1171
1172 sdio_uart_tty_driver = tty_drv = alloc_tty_driver(UART_NR);
1173 if (!tty_drv)
1174 return -ENOMEM;
1175
1176 tty_drv->driver_name = "sdio_uart";
1177 tty_drv->name = "ttySDIO";
1178 tty_drv->major = 0; /* dynamically allocated */
1179 tty_drv->minor_start = 0;
1180 tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
1181 tty_drv->subtype = SERIAL_TYPE_NORMAL;
1182 tty_drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1183 tty_drv->init_termios = tty_std_termios;
1184 tty_drv->init_termios.c_cflag = B4800 | CS8 | CREAD | HUPCL | CLOCAL;
1185 tty_drv->init_termios.c_ispeed = 4800;
1186 tty_drv->init_termios.c_ospeed = 4800;
1187 tty_set_operations(tty_drv, &sdio_uart_ops);
1188
1189 ret = tty_register_driver(tty_drv);
1190 if (ret)
1191 goto err1;
1192
1193 ret = sdio_register_driver(&sdio_uart_driver);
1194 if (ret)
1195 goto err2;
1196
1197 return 0;
1198
1199 err2:
1200 tty_unregister_driver(tty_drv);
1201 err1:
1202 put_tty_driver(tty_drv);
1203 return ret;
1204 }
1205
1206 static void __exit sdio_uart_exit(void)
1207 {
1208 sdio_unregister_driver(&sdio_uart_driver);
1209 tty_unregister_driver(sdio_uart_tty_driver);
1210 put_tty_driver(sdio_uart_tty_driver);
1211 }
1212
1213 module_init(sdio_uart_init);
1214 module_exit(sdio_uart_exit);
1215
1216 MODULE_AUTHOR("Nicolas Pitre");
1217 MODULE_LICENSE("GPL");
Linux with added FPC-III support