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sdio_uart: refcount the tty objects
[mirror_ubuntu-eoan-kernel.git] / drivers / mmc / card / sdio_uart.c
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/mutex.h>
33 #include <linux/seq_file.h>
34 #include <linux/serial_reg.h>
35 #include <linux/circ_buf.h>
36 #include <linux/gfp.h>
37 #include <linux/tty.h>
38 #include <linux/tty_flip.h>
39
40 #include <linux/mmc/core.h>
41 #include <linux/mmc/card.h>
42 #include <linux/mmc/sdio_func.h>
43 #include <linux/mmc/sdio_ids.h>
44
45
46 #define UART_NR 8 /* Number of UARTs this driver can handle */
47
48
49 #define UART_XMIT_SIZE PAGE_SIZE
50 #define WAKEUP_CHARS 256
51
52 #define circ_empty(circ) ((circ)->head == (circ)->tail)
53 #define circ_clear(circ) ((circ)->head = (circ)->tail = 0)
54
55 #define circ_chars_pending(circ) \
56 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
57
58 #define circ_chars_free(circ) \
59 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
60
61
62 struct uart_icount {
63 __u32 cts;
64 __u32 dsr;
65 __u32 rng;
66 __u32 dcd;
67 __u32 rx;
68 __u32 tx;
69 __u32 frame;
70 __u32 overrun;
71 __u32 parity;
72 __u32 brk;
73 };
74
75 struct sdio_uart_port {
76 struct tty_port port;
77 struct kref kref;
78 struct tty_struct *tty;
79 unsigned int index;
80 unsigned int opened;
81 struct mutex open_lock;
82 struct sdio_func *func;
83 struct mutex func_lock;
84 struct task_struct *in_sdio_uart_irq;
85 unsigned int regs_offset;
86 struct circ_buf xmit;
87 spinlock_t write_lock;
88 struct uart_icount icount;
89 unsigned int uartclk;
90 unsigned int mctrl;
91 unsigned int read_status_mask;
92 unsigned int ignore_status_mask;
93 unsigned char x_char;
94 unsigned char ier;
95 unsigned char lcr;
96 };
97
98 static struct sdio_uart_port *sdio_uart_table[UART_NR];
99 static DEFINE_SPINLOCK(sdio_uart_table_lock);
100
101 static int sdio_uart_add_port(struct sdio_uart_port *port)
102 {
103 int index, ret = -EBUSY;
104
105 kref_init(&port->kref);
106 mutex_init(&port->open_lock);
107 mutex_init(&port->func_lock);
108 spin_lock_init(&port->write_lock);
109
110 spin_lock(&sdio_uart_table_lock);
111 for (index = 0; index < UART_NR; index++) {
112 if (!sdio_uart_table[index]) {
113 port->index = index;
114 sdio_uart_table[index] = port;
115 ret = 0;
116 break;
117 }
118 }
119 spin_unlock(&sdio_uart_table_lock);
120
121 return ret;
122 }
123
124 static struct sdio_uart_port *sdio_uart_port_get(unsigned index)
125 {
126 struct sdio_uart_port *port;
127
128 if (index >= UART_NR)
129 return NULL;
130
131 spin_lock(&sdio_uart_table_lock);
132 port = sdio_uart_table[index];
133 if (port)
134 kref_get(&port->kref);
135 spin_unlock(&sdio_uart_table_lock);
136
137 return port;
138 }
139
140 static void sdio_uart_port_destroy(struct kref *kref)
141 {
142 struct sdio_uart_port *port =
143 container_of(kref, struct sdio_uart_port, kref);
144 kfree(port);
145 }
146
147 static void sdio_uart_port_put(struct sdio_uart_port *port)
148 {
149 kref_put(&port->kref, sdio_uart_port_destroy);
150 }
151
152 static void sdio_uart_port_remove(struct sdio_uart_port *port)
153 {
154 struct sdio_func *func;
155
156 BUG_ON(sdio_uart_table[port->index] != port);
157
158 spin_lock(&sdio_uart_table_lock);
159 sdio_uart_table[port->index] = NULL;
160 spin_unlock(&sdio_uart_table_lock);
161
162 /*
163 * We're killing a port that potentially still is in use by
164 * the tty layer. Be careful to prevent any further access
165 * to the SDIO function and arrange for the tty layer to
166 * give up on that port ASAP.
167 * Beware: the lock ordering is critical.
168 */
169 mutex_lock(&port->open_lock);
170 mutex_lock(&port->func_lock);
171 func = port->func;
172 sdio_claim_host(func);
173 port->func = NULL;
174 mutex_unlock(&port->func_lock);
175 if (port->opened) {
176 struct tty_struct *tty = tty_port_tty_get(&port->port);
177 /* tty_hangup is async so is this safe as is ?? */
178 if (tty)
179 tty_hangup(tty);
180 tty_kref_put(tty);
181 }
182 mutex_unlock(&port->open_lock);
183 sdio_release_irq(func);
184 sdio_disable_func(func);
185 sdio_release_host(func);
186
187 sdio_uart_port_put(port);
188 }
189
190 static int sdio_uart_claim_func(struct sdio_uart_port *port)
191 {
192 mutex_lock(&port->func_lock);
193 if (unlikely(!port->func)) {
194 mutex_unlock(&port->func_lock);
195 return -ENODEV;
196 }
197 if (likely(port->in_sdio_uart_irq != current))
198 sdio_claim_host(port->func);
199 mutex_unlock(&port->func_lock);
200 return 0;
201 }
202
203 static inline void sdio_uart_release_func(struct sdio_uart_port *port)
204 {
205 if (likely(port->in_sdio_uart_irq != current))
206 sdio_release_host(port->func);
207 }
208
209 static inline unsigned int sdio_in(struct sdio_uart_port *port, int offset)
210 {
211 unsigned char c;
212 c = sdio_readb(port->func, port->regs_offset + offset, NULL);
213 return c;
214 }
215
216 static inline void sdio_out(struct sdio_uart_port *port, int offset, int value)
217 {
218 sdio_writeb(port->func, value, port->regs_offset + offset, NULL);
219 }
220
221 static unsigned int sdio_uart_get_mctrl(struct sdio_uart_port *port)
222 {
223 unsigned char status;
224 unsigned int ret;
225
226 status = sdio_in(port, UART_MSR);
227
228 ret = 0;
229 if (status & UART_MSR_DCD)
230 ret |= TIOCM_CAR;
231 if (status & UART_MSR_RI)
232 ret |= TIOCM_RNG;
233 if (status & UART_MSR_DSR)
234 ret |= TIOCM_DSR;
235 if (status & UART_MSR_CTS)
236 ret |= TIOCM_CTS;
237 return ret;
238 }
239
240 static void sdio_uart_write_mctrl(struct sdio_uart_port *port,
241 unsigned int mctrl)
242 {
243 unsigned char mcr = 0;
244
245 if (mctrl & TIOCM_RTS)
246 mcr |= UART_MCR_RTS;
247 if (mctrl & TIOCM_DTR)
248 mcr |= UART_MCR_DTR;
249 if (mctrl & TIOCM_OUT1)
250 mcr |= UART_MCR_OUT1;
251 if (mctrl & TIOCM_OUT2)
252 mcr |= UART_MCR_OUT2;
253 if (mctrl & TIOCM_LOOP)
254 mcr |= UART_MCR_LOOP;
255
256 sdio_out(port, UART_MCR, mcr);
257 }
258
259 static inline void sdio_uart_update_mctrl(struct sdio_uart_port *port,
260 unsigned int set, unsigned int clear)
261 {
262 unsigned int old;
263
264 old = port->mctrl;
265 port->mctrl = (old & ~clear) | set;
266 if (old != port->mctrl)
267 sdio_uart_write_mctrl(port, port->mctrl);
268 }
269
270 #define sdio_uart_set_mctrl(port, x) sdio_uart_update_mctrl(port, x, 0)
271 #define sdio_uart_clear_mctrl(port, x) sdio_uart_update_mctrl(port, 0, x)
272
273 static void sdio_uart_change_speed(struct sdio_uart_port *port,
274 struct ktermios *termios,
275 struct ktermios *old)
276 {
277 unsigned char cval, fcr = 0;
278 unsigned int baud, quot;
279
280 switch (termios->c_cflag & CSIZE) {
281 case CS5:
282 cval = UART_LCR_WLEN5;
283 break;
284 case CS6:
285 cval = UART_LCR_WLEN6;
286 break;
287 case CS7:
288 cval = UART_LCR_WLEN7;
289 break;
290 default:
291 case CS8:
292 cval = UART_LCR_WLEN8;
293 break;
294 }
295
296 if (termios->c_cflag & CSTOPB)
297 cval |= UART_LCR_STOP;
298 if (termios->c_cflag & PARENB)
299 cval |= UART_LCR_PARITY;
300 if (!(termios->c_cflag & PARODD))
301 cval |= UART_LCR_EPAR;
302
303 for (;;) {
304 baud = tty_termios_baud_rate(termios);
305 if (baud == 0)
306 baud = 9600; /* Special case: B0 rate. */
307 if (baud <= port->uartclk)
308 break;
309 /*
310 * Oops, the quotient was zero. Try again with the old
311 * baud rate if possible, otherwise default to 9600.
312 */
313 termios->c_cflag &= ~CBAUD;
314 if (old) {
315 termios->c_cflag |= old->c_cflag & CBAUD;
316 old = NULL;
317 } else
318 termios->c_cflag |= B9600;
319 }
320 quot = (2 * port->uartclk + baud) / (2 * baud);
321
322 if (baud < 2400)
323 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
324 else
325 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10;
326
327 port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
328 if (termios->c_iflag & INPCK)
329 port->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
330 if (termios->c_iflag & (BRKINT | PARMRK))
331 port->read_status_mask |= UART_LSR_BI;
332
333 /*
334 * Characters to ignore
335 */
336 port->ignore_status_mask = 0;
337 if (termios->c_iflag & IGNPAR)
338 port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
339 if (termios->c_iflag & IGNBRK) {
340 port->ignore_status_mask |= UART_LSR_BI;
341 /*
342 * If we're ignoring parity and break indicators,
343 * ignore overruns too (for real raw support).
344 */
345 if (termios->c_iflag & IGNPAR)
346 port->ignore_status_mask |= UART_LSR_OE;
347 }
348
349 /*
350 * ignore all characters if CREAD is not set
351 */
352 if ((termios->c_cflag & CREAD) == 0)
353 port->ignore_status_mask |= UART_LSR_DR;
354
355 /*
356 * CTS flow control flag and modem status interrupts
357 */
358 port->ier &= ~UART_IER_MSI;
359 if ((termios->c_cflag & CRTSCTS) || !(termios->c_cflag & CLOCAL))
360 port->ier |= UART_IER_MSI;
361
362 port->lcr = cval;
363
364 sdio_out(port, UART_IER, port->ier);
365 sdio_out(port, UART_LCR, cval | UART_LCR_DLAB);
366 sdio_out(port, UART_DLL, quot & 0xff);
367 sdio_out(port, UART_DLM, quot >> 8);
368 sdio_out(port, UART_LCR, cval);
369 sdio_out(port, UART_FCR, fcr);
370
371 sdio_uart_write_mctrl(port, port->mctrl);
372 }
373
374 static void sdio_uart_start_tx(struct sdio_uart_port *port)
375 {
376 if (!(port->ier & UART_IER_THRI)) {
377 port->ier |= UART_IER_THRI;
378 sdio_out(port, UART_IER, port->ier);
379 }
380 }
381
382 static void sdio_uart_stop_tx(struct sdio_uart_port *port)
383 {
384 if (port->ier & UART_IER_THRI) {
385 port->ier &= ~UART_IER_THRI;
386 sdio_out(port, UART_IER, port->ier);
387 }
388 }
389
390 static void sdio_uart_stop_rx(struct sdio_uart_port *port)
391 {
392 port->ier &= ~UART_IER_RLSI;
393 port->read_status_mask &= ~UART_LSR_DR;
394 sdio_out(port, UART_IER, port->ier);
395 }
396
397 static void sdio_uart_receive_chars(struct sdio_uart_port *port,
398 unsigned int *status)
399 {
400 struct tty_struct *tty = tty_port_tty_get(&port->port);
401 unsigned int ch, flag;
402 int max_count = 256;
403
404 do {
405 ch = sdio_in(port, UART_RX);
406 flag = TTY_NORMAL;
407 port->icount.rx++;
408
409 if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
410 UART_LSR_FE | UART_LSR_OE))) {
411 /*
412 * For statistics only
413 */
414 if (*status & UART_LSR_BI) {
415 *status &= ~(UART_LSR_FE | UART_LSR_PE);
416 port->icount.brk++;
417 } else if (*status & UART_LSR_PE)
418 port->icount.parity++;
419 else if (*status & UART_LSR_FE)
420 port->icount.frame++;
421 if (*status & UART_LSR_OE)
422 port->icount.overrun++;
423
424 /*
425 * Mask off conditions which should be ignored.
426 */
427 *status &= port->read_status_mask;
428 if (*status & UART_LSR_BI)
429 flag = TTY_BREAK;
430 else if (*status & UART_LSR_PE)
431 flag = TTY_PARITY;
432 else if (*status & UART_LSR_FE)
433 flag = TTY_FRAME;
434 }
435
436 if ((*status & port->ignore_status_mask & ~UART_LSR_OE) == 0)
437 if (tty)
438 tty_insert_flip_char(tty, ch, flag);
439
440 /*
441 * Overrun is special. Since it's reported immediately,
442 * it doesn't affect the current character.
443 */
444 if (*status & ~port->ignore_status_mask & UART_LSR_OE)
445 if (tty)
446 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
447
448 *status = sdio_in(port, UART_LSR);
449 } while ((*status & UART_LSR_DR) && (max_count-- > 0));
450 if (tty) {
451 tty_flip_buffer_push(tty);
452 tty_kref_put(tty);
453 }
454 }
455
456 static void sdio_uart_transmit_chars(struct sdio_uart_port *port)
457 {
458 struct circ_buf *xmit = &port->xmit;
459 int count;
460 struct tty_struct *tty;
461
462 if (port->x_char) {
463 sdio_out(port, UART_TX, port->x_char);
464 port->icount.tx++;
465 port->x_char = 0;
466 return;
467 }
468
469 tty = tty_port_tty_get(&port->port);
470
471 if (tty == NULL || circ_empty(xmit) || tty->stopped || tty->hw_stopped) {
472 sdio_uart_stop_tx(port);
473 tty_kref_put(tty);
474 return;
475 }
476
477 count = 16;
478 do {
479 sdio_out(port, UART_TX, xmit->buf[xmit->tail]);
480 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
481 port->icount.tx++;
482 if (circ_empty(xmit))
483 break;
484 } while (--count > 0);
485
486 if (circ_chars_pending(xmit) < WAKEUP_CHARS)
487 tty_wakeup(tty);
488
489 if (circ_empty(xmit))
490 sdio_uart_stop_tx(port);
491 tty_kref_put(tty);
492 }
493
494 static void sdio_uart_check_modem_status(struct sdio_uart_port *port)
495 {
496 int status;
497 struct tty_struct *tty;
498
499 status = sdio_in(port, UART_MSR);
500
501 if ((status & UART_MSR_ANY_DELTA) == 0)
502 return;
503
504 if (status & UART_MSR_TERI)
505 port->icount.rng++;
506 if (status & UART_MSR_DDSR)
507 port->icount.dsr++;
508 if (status & UART_MSR_DDCD)
509 port->icount.dcd++;
510 if (status & UART_MSR_DCTS) {
511 port->icount.cts++;
512 tty = tty_port_tty_get(&port->port);
513 if (tty && (tty->termios->c_cflag & CRTSCTS)) {
514 int cts = (status & UART_MSR_CTS);
515 if (tty->hw_stopped) {
516 if (cts) {
517 tty->hw_stopped = 0;
518 sdio_uart_start_tx(port);
519 tty_wakeup(tty);
520 }
521 } else {
522 if (!cts) {
523 tty->hw_stopped = 1;
524 sdio_uart_stop_tx(port);
525 }
526 }
527 }
528 tty_kref_put(tty);
529 }
530 }
531
532 /*
533 * This handles the interrupt from one port.
534 */
535 static void sdio_uart_irq(struct sdio_func *func)
536 {
537 struct sdio_uart_port *port = sdio_get_drvdata(func);
538 unsigned int iir, lsr;
539
540 /*
541 * In a few places sdio_uart_irq() is called directly instead of
542 * waiting for the actual interrupt to be raised and the SDIO IRQ
543 * thread scheduled in order to reduce latency. However, some
544 * interaction with the tty core may end up calling us back
545 * (serial echo, flow control, etc.) through those same places
546 * causing undesirable effects. Let's stop the recursion here.
547 */
548 if (unlikely(port->in_sdio_uart_irq == current))
549 return;
550
551 iir = sdio_in(port, UART_IIR);
552 if (iir & UART_IIR_NO_INT)
553 return;
554
555 port->in_sdio_uart_irq = current;
556 lsr = sdio_in(port, UART_LSR);
557 if (lsr & UART_LSR_DR)
558 sdio_uart_receive_chars(port, &lsr);
559 sdio_uart_check_modem_status(port);
560 if (lsr & UART_LSR_THRE)
561 sdio_uart_transmit_chars(port);
562 port->in_sdio_uart_irq = NULL;
563 }
564
565 static int sdio_uart_startup(struct sdio_uart_port *port)
566 {
567 unsigned long page;
568 int ret = -ENOMEM;
569 struct tty_struct *tty = tty_port_tty_get(&port->port);
570
571 /* FIXME: What if it is NULL ?? */
572
573 /*
574 * Set the TTY IO error marker - we will only clear this
575 * once we have successfully opened the port.
576 */
577 set_bit(TTY_IO_ERROR, &tty->flags);
578
579 /* Initialise and allocate the transmit buffer. */
580 page = __get_free_page(GFP_KERNEL);
581 if (!page)
582 goto err0;
583 port->xmit.buf = (unsigned char *)page;
584 circ_clear(&port->xmit);
585
586 ret = sdio_uart_claim_func(port);
587 if (ret)
588 goto err1;
589 ret = sdio_enable_func(port->func);
590 if (ret)
591 goto err2;
592 ret = sdio_claim_irq(port->func, sdio_uart_irq);
593 if (ret)
594 goto err3;
595
596 /*
597 * Clear the FIFO buffers and disable them.
598 * (they will be reenabled in sdio_change_speed())
599 */
600 sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO);
601 sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO |
602 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
603 sdio_out(port, UART_FCR, 0);
604
605 /*
606 * Clear the interrupt registers.
607 */
608 (void) sdio_in(port, UART_LSR);
609 (void) sdio_in(port, UART_RX);
610 (void) sdio_in(port, UART_IIR);
611 (void) sdio_in(port, UART_MSR);
612
613 /*
614 * Now, initialize the UART
615 */
616 sdio_out(port, UART_LCR, UART_LCR_WLEN8);
617
618 port->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
619 port->mctrl = TIOCM_OUT2;
620
621 sdio_uart_change_speed(port, tty->termios, NULL);
622
623 if (tty->termios->c_cflag & CBAUD)
624 sdio_uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
625
626 if (tty->termios->c_cflag & CRTSCTS)
627 if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS))
628 tty->hw_stopped = 1;
629
630 clear_bit(TTY_IO_ERROR, &tty->flags);
631
632 /* Kick the IRQ handler once while we're still holding the host lock */
633 sdio_uart_irq(port->func);
634
635 sdio_uart_release_func(port);
636 tty_kref_put(tty);
637 return 0;
638
639 err3:
640 sdio_disable_func(port->func);
641 err2:
642 sdio_uart_release_func(port);
643 err1:
644 free_page((unsigned long)port->xmit.buf);
645 err0:
646 tty_kref_put(tty);
647 return ret;
648 }
649
650 static void sdio_uart_shutdown(struct sdio_uart_port *port)
651 {
652 int ret;
653 struct tty_struct *tty;
654
655 ret = sdio_uart_claim_func(port);
656 if (ret)
657 goto skip;
658
659 sdio_uart_stop_rx(port);
660
661 /* TODO: wait here for TX FIFO to drain */
662
663 tty = tty_port_tty_get(&port->port);
664 /* Turn off DTR and RTS early. */
665 if (tty && (tty->termios->c_cflag & HUPCL))
666 sdio_uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
667 tty_kref_put(tty);
668
669 /* Disable interrupts from this port */
670 sdio_release_irq(port->func);
671 port->ier = 0;
672 sdio_out(port, UART_IER, 0);
673
674 sdio_uart_clear_mctrl(port, TIOCM_OUT2);
675
676 /* Disable break condition and FIFOs. */
677 port->lcr &= ~UART_LCR_SBC;
678 sdio_out(port, UART_LCR, port->lcr);
679 sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO |
680 UART_FCR_CLEAR_RCVR |
681 UART_FCR_CLEAR_XMIT);
682 sdio_out(port, UART_FCR, 0);
683
684 sdio_disable_func(port->func);
685
686 sdio_uart_release_func(port);
687
688 skip:
689 /* Free the transmit buffer page. */
690 free_page((unsigned long)port->xmit.buf);
691 }
692
693 static int sdio_uart_open(struct tty_struct *tty, struct file *filp)
694 {
695 struct sdio_uart_port *port;
696 int ret;
697
698 port = sdio_uart_port_get(tty->index);
699 if (!port)
700 return -ENODEV;
701
702 mutex_lock(&port->open_lock);
703
704 /*
705 * Make sure not to mess up with a dead port
706 * which has not been closed yet.
707 */
708 if (tty->driver_data && tty->driver_data != port) {
709 mutex_unlock(&port->open_lock);
710 sdio_uart_port_put(port);
711 return -EBUSY;
712 }
713
714 if (!port->opened) {
715 tty->driver_data = port;
716 tty_port_tty_set(&port->port, tty);
717 ret = sdio_uart_startup(port);
718 if (ret) {
719 tty->driver_data = NULL;
720 tty_port_tty_set(&port->port, NULL);
721 mutex_unlock(&port->open_lock);
722 sdio_uart_port_put(port);
723 return ret;
724 }
725 }
726 port->opened++;
727 mutex_unlock(&port->open_lock);
728 return 0;
729 }
730
731 static void sdio_uart_close(struct tty_struct *tty, struct file * filp)
732 {
733 struct sdio_uart_port *port = tty->driver_data;
734
735 if (!port)
736 return;
737
738 mutex_lock(&port->open_lock);
739 BUG_ON(!port->opened);
740
741 /*
742 * This is messy. The tty layer calls us even when open()
743 * returned an error. Ignore this close request if tty->count
744 * is larger than port->count.
745 */
746 if (tty->count > port->opened) {
747 mutex_unlock(&port->open_lock);
748 return;
749 }
750
751 if (--port->opened == 0) {
752 tty->closing = 1;
753 sdio_uart_shutdown(port);
754 tty_ldisc_flush(tty);
755 tty_port_tty_set(&port->port, NULL);
756 tty->driver_data = NULL;
757 tty->closing = 0;
758 }
759 mutex_unlock(&port->open_lock);
760 sdio_uart_port_put(port);
761 }
762
763 static int sdio_uart_write(struct tty_struct * tty, const unsigned char *buf,
764 int count)
765 {
766 struct sdio_uart_port *port = tty->driver_data;
767 struct circ_buf *circ = &port->xmit;
768 int c, ret = 0;
769
770 if (!port->func)
771 return -ENODEV;
772
773 spin_lock(&port->write_lock);
774 while (1) {
775 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
776 if (count < c)
777 c = count;
778 if (c <= 0)
779 break;
780 memcpy(circ->buf + circ->head, buf, c);
781 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
782 buf += c;
783 count -= c;
784 ret += c;
785 }
786 spin_unlock(&port->write_lock);
787
788 if ( !(port->ier & UART_IER_THRI)) {
789 int err = sdio_uart_claim_func(port);
790 if (!err) {
791 sdio_uart_start_tx(port);
792 sdio_uart_irq(port->func);
793 sdio_uart_release_func(port);
794 } else
795 ret = err;
796 }
797
798 return ret;
799 }
800
801 static int sdio_uart_write_room(struct tty_struct *tty)
802 {
803 struct sdio_uart_port *port = tty->driver_data;
804 return port ? circ_chars_free(&port->xmit) : 0;
805 }
806
807 static int sdio_uart_chars_in_buffer(struct tty_struct *tty)
808 {
809 struct sdio_uart_port *port = tty->driver_data;
810 return port ? circ_chars_pending(&port->xmit) : 0;
811 }
812
813 static void sdio_uart_send_xchar(struct tty_struct *tty, char ch)
814 {
815 struct sdio_uart_port *port = tty->driver_data;
816
817 port->x_char = ch;
818 if (ch && !(port->ier & UART_IER_THRI)) {
819 if (sdio_uart_claim_func(port) != 0)
820 return;
821 sdio_uart_start_tx(port);
822 sdio_uart_irq(port->func);
823 sdio_uart_release_func(port);
824 }
825 }
826
827 static void sdio_uart_throttle(struct tty_struct *tty)
828 {
829 struct sdio_uart_port *port = tty->driver_data;
830
831 if (!I_IXOFF(tty) && !(tty->termios->c_cflag & CRTSCTS))
832 return;
833
834 if (sdio_uart_claim_func(port) != 0)
835 return;
836
837 if (I_IXOFF(tty)) {
838 port->x_char = STOP_CHAR(tty);
839 sdio_uart_start_tx(port);
840 }
841
842 if (tty->termios->c_cflag & CRTSCTS)
843 sdio_uart_clear_mctrl(port, TIOCM_RTS);
844
845 sdio_uart_irq(port->func);
846 sdio_uart_release_func(port);
847 }
848
849 static void sdio_uart_unthrottle(struct tty_struct *tty)
850 {
851 struct sdio_uart_port *port = tty->driver_data;
852
853 if (!I_IXOFF(tty) && !(tty->termios->c_cflag & CRTSCTS))
854 return;
855
856 if (sdio_uart_claim_func(port) != 0)
857 return;
858
859 if (I_IXOFF(tty)) {
860 if (port->x_char) {
861 port->x_char = 0;
862 } else {
863 port->x_char = START_CHAR(tty);
864 sdio_uart_start_tx(port);
865 }
866 }
867
868 if (tty->termios->c_cflag & CRTSCTS)
869 sdio_uart_set_mctrl(port, TIOCM_RTS);
870
871 sdio_uart_irq(port->func);
872 sdio_uart_release_func(port);
873 }
874
875 static void sdio_uart_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
876 {
877 struct sdio_uart_port *port = tty->driver_data;
878 unsigned int cflag = tty->termios->c_cflag;
879
880 #define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
881
882 if ((cflag ^ old_termios->c_cflag) == 0 &&
883 RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0)
884 return;
885
886 if (sdio_uart_claim_func(port) != 0)
887 return;
888
889 sdio_uart_change_speed(port, tty->termios, old_termios);
890
891 /* Handle transition to B0 status */
892 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
893 sdio_uart_clear_mctrl(port, TIOCM_RTS | TIOCM_DTR);
894
895 /* Handle transition away from B0 status */
896 if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
897 unsigned int mask = TIOCM_DTR;
898 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
899 mask |= TIOCM_RTS;
900 sdio_uart_set_mctrl(port, mask);
901 }
902
903 /* Handle turning off CRTSCTS */
904 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
905 tty->hw_stopped = 0;
906 sdio_uart_start_tx(port);
907 }
908
909 /* Handle turning on CRTSCTS */
910 if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
911 if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS)) {
912 tty->hw_stopped = 1;
913 sdio_uart_stop_tx(port);
914 }
915 }
916
917 sdio_uart_release_func(port);
918 }
919
920 static int sdio_uart_break_ctl(struct tty_struct *tty, int break_state)
921 {
922 struct sdio_uart_port *port = tty->driver_data;
923 int result;
924
925 result = sdio_uart_claim_func(port);
926 if (result != 0)
927 return result;
928
929 if (break_state == -1)
930 port->lcr |= UART_LCR_SBC;
931 else
932 port->lcr &= ~UART_LCR_SBC;
933 sdio_out(port, UART_LCR, port->lcr);
934
935 sdio_uart_release_func(port);
936 return 0;
937 }
938
939 static int sdio_uart_tiocmget(struct tty_struct *tty, struct file *file)
940 {
941 struct sdio_uart_port *port = tty->driver_data;
942 int result;
943
944 result = sdio_uart_claim_func(port);
945 if (!result) {
946 result = port->mctrl | sdio_uart_get_mctrl(port);
947 sdio_uart_release_func(port);
948 }
949
950 return result;
951 }
952
953 static int sdio_uart_tiocmset(struct tty_struct *tty, struct file *file,
954 unsigned int set, unsigned int clear)
955 {
956 struct sdio_uart_port *port = tty->driver_data;
957 int result;
958
959 result = sdio_uart_claim_func(port);
960 if(!result) {
961 sdio_uart_update_mctrl(port, set, clear);
962 sdio_uart_release_func(port);
963 }
964
965 return result;
966 }
967
968 static int sdio_uart_proc_show(struct seq_file *m, void *v)
969 {
970 int i;
971
972 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
973 "", "", "");
974 for (i = 0; i < UART_NR; i++) {
975 struct sdio_uart_port *port = sdio_uart_port_get(i);
976 if (port) {
977 seq_printf(m, "%d: uart:SDIO", i);
978 if(capable(CAP_SYS_ADMIN)) {
979 seq_printf(m, " tx:%d rx:%d",
980 port->icount.tx, port->icount.rx);
981 if (port->icount.frame)
982 seq_printf(m, " fe:%d",
983 port->icount.frame);
984 if (port->icount.parity)
985 seq_printf(m, " pe:%d",
986 port->icount.parity);
987 if (port->icount.brk)
988 seq_printf(m, " brk:%d",
989 port->icount.brk);
990 if (port->icount.overrun)
991 seq_printf(m, " oe:%d",
992 port->icount.overrun);
993 if (port->icount.cts)
994 seq_printf(m, " cts:%d",
995 port->icount.cts);
996 if (port->icount.dsr)
997 seq_printf(m, " dsr:%d",
998 port->icount.dsr);
999 if (port->icount.rng)
1000 seq_printf(m, " rng:%d",
1001 port->icount.rng);
1002 if (port->icount.dcd)
1003 seq_printf(m, " dcd:%d",
1004 port->icount.dcd);
1005 }
1006 sdio_uart_port_put(port);
1007 seq_putc(m, '\n');
1008 }
1009 }
1010 return 0;
1011 }
1012
1013 static int sdio_uart_proc_open(struct inode *inode, struct file *file)
1014 {
1015 return single_open(file, sdio_uart_proc_show, NULL);
1016 }
1017
1018 static const struct file_operations sdio_uart_proc_fops = {
1019 .owner = THIS_MODULE,
1020 .open = sdio_uart_proc_open,
1021 .read = seq_read,
1022 .llseek = seq_lseek,
1023 .release = single_release,
1024 };
1025
1026 static const struct tty_operations sdio_uart_ops = {
1027 .open = sdio_uart_open,
1028 .close = sdio_uart_close,
1029 .write = sdio_uart_write,
1030 .write_room = sdio_uart_write_room,
1031 .chars_in_buffer = sdio_uart_chars_in_buffer,
1032 .send_xchar = sdio_uart_send_xchar,
1033 .throttle = sdio_uart_throttle,
1034 .unthrottle = sdio_uart_unthrottle,
1035 .set_termios = sdio_uart_set_termios,
1036 .break_ctl = sdio_uart_break_ctl,
1037 .tiocmget = sdio_uart_tiocmget,
1038 .tiocmset = sdio_uart_tiocmset,
1039 .proc_fops = &sdio_uart_proc_fops,
1040 };
1041
1042 static struct tty_driver *sdio_uart_tty_driver;
1043
1044 static int sdio_uart_probe(struct sdio_func *func,
1045 const struct sdio_device_id *id)
1046 {
1047 struct sdio_uart_port *port;
1048 int ret;
1049
1050 port = kzalloc(sizeof(struct sdio_uart_port), GFP_KERNEL);
1051 if (!port)
1052 return -ENOMEM;
1053
1054 if (func->class == SDIO_CLASS_UART) {
1055 printk(KERN_WARNING "%s: need info on UART class basic setup\n",
1056 sdio_func_id(func));
1057 kfree(port);
1058 return -ENOSYS;
1059 } else if (func->class == SDIO_CLASS_GPS) {
1060 /*
1061 * We need tuple 0x91. It contains SUBTPL_SIOREG
1062 * and SUBTPL_RCVCAPS.
1063 */
1064 struct sdio_func_tuple *tpl;
1065 for (tpl = func->tuples; tpl; tpl = tpl->next) {
1066 if (tpl->code != 0x91)
1067 continue;
1068 if (tpl->size < 10)
1069 continue;
1070 if (tpl->data[1] == 0) /* SUBTPL_SIOREG */
1071 break;
1072 }
1073 if (!tpl) {
1074 printk(KERN_WARNING
1075 "%s: can't find tuple 0x91 subtuple 0 (SUBTPL_SIOREG) for GPS class\n",
1076 sdio_func_id(func));
1077 kfree(port);
1078 return -EINVAL;
1079 }
1080 printk(KERN_DEBUG "%s: Register ID = 0x%02x, Exp ID = 0x%02x\n",
1081 sdio_func_id(func), tpl->data[2], tpl->data[3]);
1082 port->regs_offset = (tpl->data[4] << 0) |
1083 (tpl->data[5] << 8) |
1084 (tpl->data[6] << 16);
1085 printk(KERN_DEBUG "%s: regs offset = 0x%x\n",
1086 sdio_func_id(func), port->regs_offset);
1087 port->uartclk = tpl->data[7] * 115200;
1088 if (port->uartclk == 0)
1089 port->uartclk = 115200;
1090 printk(KERN_DEBUG "%s: clk %d baudcode %u 4800-div %u\n",
1091 sdio_func_id(func), port->uartclk,
1092 tpl->data[7], tpl->data[8] | (tpl->data[9] << 8));
1093 } else {
1094 kfree(port);
1095 return -EINVAL;
1096 }
1097
1098 port->func = func;
1099 sdio_set_drvdata(func, port);
1100 tty_port_init(&port->port);
1101
1102 ret = sdio_uart_add_port(port);
1103 if (ret) {
1104 kfree(port);
1105 } else {
1106 struct device *dev;
1107 dev = tty_register_device(sdio_uart_tty_driver, port->index, &func->dev);
1108 if (IS_ERR(dev)) {
1109 sdio_uart_port_remove(port);
1110 ret = PTR_ERR(dev);
1111 }
1112 }
1113
1114 return ret;
1115 }
1116
1117 static void sdio_uart_remove(struct sdio_func *func)
1118 {
1119 struct sdio_uart_port *port = sdio_get_drvdata(func);
1120
1121 tty_unregister_device(sdio_uart_tty_driver, port->index);
1122 sdio_uart_port_remove(port);
1123 }
1124
1125 static const struct sdio_device_id sdio_uart_ids[] = {
1126 { SDIO_DEVICE_CLASS(SDIO_CLASS_UART) },
1127 { SDIO_DEVICE_CLASS(SDIO_CLASS_GPS) },
1128 { /* end: all zeroes */ },
1129 };
1130
1131 MODULE_DEVICE_TABLE(sdio, sdio_uart_ids);
1132
1133 static struct sdio_driver sdio_uart_driver = {
1134 .probe = sdio_uart_probe,
1135 .remove = sdio_uart_remove,
1136 .name = "sdio_uart",
1137 .id_table = sdio_uart_ids,
1138 };
1139
1140 static int __init sdio_uart_init(void)
1141 {
1142 int ret;
1143 struct tty_driver *tty_drv;
1144
1145 sdio_uart_tty_driver = tty_drv = alloc_tty_driver(UART_NR);
1146 if (!tty_drv)
1147 return -ENOMEM;
1148
1149 tty_drv->owner = THIS_MODULE;
1150 tty_drv->driver_name = "sdio_uart";
1151 tty_drv->name = "ttySDIO";
1152 tty_drv->major = 0; /* dynamically allocated */
1153 tty_drv->minor_start = 0;
1154 tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
1155 tty_drv->subtype = SERIAL_TYPE_NORMAL;
1156 tty_drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1157 tty_drv->init_termios = tty_std_termios;
1158 tty_drv->init_termios.c_cflag = B4800 | CS8 | CREAD | HUPCL | CLOCAL;
1159 tty_drv->init_termios.c_ispeed = 4800;
1160 tty_drv->init_termios.c_ospeed = 4800;
1161 tty_set_operations(tty_drv, &sdio_uart_ops);
1162
1163 ret = tty_register_driver(tty_drv);
1164 if (ret)
1165 goto err1;
1166
1167 ret = sdio_register_driver(&sdio_uart_driver);
1168 if (ret)
1169 goto err2;
1170
1171 return 0;
1172
1173 err2:
1174 tty_unregister_driver(tty_drv);
1175 err1:
1176 put_tty_driver(tty_drv);
1177 return ret;
1178 }
1179
1180 static void __exit sdio_uart_exit(void)
1181 {
1182 sdio_unregister_driver(&sdio_uart_driver);
1183 tty_unregister_driver(sdio_uart_tty_driver);
1184 put_tty_driver(sdio_uart_tty_driver);
1185 }
1186
1187 module_init(sdio_uart_init);
1188 module_exit(sdio_uart_exit);
1189
1190 MODULE_AUTHOR("Nicolas Pitre");
1191 MODULE_LICENSE("GPL");
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