Loading...
Note: File does not exist in v5.14.15.
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
54struct 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
67struct 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
89static struct sdio_uart_port *sdio_uart_table[UART_NR];
90static DEFINE_SPINLOCK(sdio_uart_table_lock);
91
92static 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
116static 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
132static 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
140static void sdio_uart_port_put(struct sdio_uart_port *port)
141{
142 kref_put(&port->kref, sdio_uart_port_destroy);
143}
144
145static 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
183static 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
196static 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
202static 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
209static 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
214static 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
235static 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
254static 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
268static 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
369static 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
377static 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
385static 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
392static 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
451static 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
490static 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 */
543static 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
573static 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
596static 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
625static 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
691err2:
692 sdio_disable_func(port->func);
693err1:
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
708static 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
749static 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_standard_install(driver, tty);
754
755 if (ret == 0)
756 /* This is the ref sdio_uart_port get provided */
757 tty->driver_data = port;
758 else
759 sdio_uart_port_put(port);
760 return ret;
761}
762
763/**
764 * sdio_uart_cleanup - called on the last tty kref drop
765 * @tty: the tty being destroyed
766 *
767 * Called asynchronously when the last reference to the tty is dropped.
768 * We cannot destroy the tty->driver_data port kref until this point
769 */
770
771static void sdio_uart_cleanup(struct tty_struct *tty)
772{
773 struct sdio_uart_port *port = tty->driver_data;
774 tty->driver_data = NULL; /* Bug trap */
775 sdio_uart_port_put(port);
776}
777
778/*
779 * Open/close/hangup is now entirely boilerplate
780 */
781
782static int sdio_uart_open(struct tty_struct *tty, struct file *filp)
783{
784 struct sdio_uart_port *port = tty->driver_data;
785 return tty_port_open(&port->port, tty, filp);
786}
787
788static void sdio_uart_close(struct tty_struct *tty, struct file * filp)
789{
790 struct sdio_uart_port *port = tty->driver_data;
791 tty_port_close(&port->port, tty, filp);
792}
793
794static void sdio_uart_hangup(struct tty_struct *tty)
795{
796 struct sdio_uart_port *port = tty->driver_data;
797 tty_port_hangup(&port->port);
798}
799
800static int sdio_uart_write(struct tty_struct *tty, const unsigned char *buf,
801 int count)
802{
803 struct sdio_uart_port *port = tty->driver_data;
804 int ret;
805
806 if (!port->func)
807 return -ENODEV;
808
809 ret = kfifo_in_locked(&port->xmit_fifo, buf, count, &port->write_lock);
810 if (!(port->ier & UART_IER_THRI)) {
811 int err = sdio_uart_claim_func(port);
812 if (!err) {
813 sdio_uart_start_tx(port);
814 sdio_uart_irq(port->func);
815 sdio_uart_release_func(port);
816 } else
817 ret = err;
818 }
819
820 return ret;
821}
822
823static int sdio_uart_write_room(struct tty_struct *tty)
824{
825 struct sdio_uart_port *port = tty->driver_data;
826 return FIFO_SIZE - kfifo_len(&port->xmit_fifo);
827}
828
829static int sdio_uart_chars_in_buffer(struct tty_struct *tty)
830{
831 struct sdio_uart_port *port = tty->driver_data;
832 return kfifo_len(&port->xmit_fifo);
833}
834
835static void sdio_uart_send_xchar(struct tty_struct *tty, char ch)
836{
837 struct sdio_uart_port *port = tty->driver_data;
838
839 port->x_char = ch;
840 if (ch && !(port->ier & UART_IER_THRI)) {
841 if (sdio_uart_claim_func(port) != 0)
842 return;
843 sdio_uart_start_tx(port);
844 sdio_uart_irq(port->func);
845 sdio_uart_release_func(port);
846 }
847}
848
849static void sdio_uart_throttle(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 port->x_char = STOP_CHAR(tty);
861 sdio_uart_start_tx(port);
862 }
863
864 if (tty->termios->c_cflag & CRTSCTS)
865 sdio_uart_clear_mctrl(port, TIOCM_RTS);
866
867 sdio_uart_irq(port->func);
868 sdio_uart_release_func(port);
869}
870
871static void sdio_uart_unthrottle(struct tty_struct *tty)
872{
873 struct sdio_uart_port *port = tty->driver_data;
874
875 if (!I_IXOFF(tty) && !(tty->termios->c_cflag & CRTSCTS))
876 return;
877
878 if (sdio_uart_claim_func(port) != 0)
879 return;
880
881 if (I_IXOFF(tty)) {
882 if (port->x_char) {
883 port->x_char = 0;
884 } else {
885 port->x_char = START_CHAR(tty);
886 sdio_uart_start_tx(port);
887 }
888 }
889
890 if (tty->termios->c_cflag & CRTSCTS)
891 sdio_uart_set_mctrl(port, TIOCM_RTS);
892
893 sdio_uart_irq(port->func);
894 sdio_uart_release_func(port);
895}
896
897static void sdio_uart_set_termios(struct tty_struct *tty,
898 struct ktermios *old_termios)
899{
900 struct sdio_uart_port *port = tty->driver_data;
901 unsigned int cflag = tty->termios->c_cflag;
902
903 if (sdio_uart_claim_func(port) != 0)
904 return;
905
906 sdio_uart_change_speed(port, tty->termios, old_termios);
907
908 /* Handle transition to B0 status */
909 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
910 sdio_uart_clear_mctrl(port, TIOCM_RTS | TIOCM_DTR);
911
912 /* Handle transition away from B0 status */
913 if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
914 unsigned int mask = TIOCM_DTR;
915 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
916 mask |= TIOCM_RTS;
917 sdio_uart_set_mctrl(port, mask);
918 }
919
920 /* Handle turning off CRTSCTS */
921 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
922 tty->hw_stopped = 0;
923 sdio_uart_start_tx(port);
924 }
925
926 /* Handle turning on CRTSCTS */
927 if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
928 if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS)) {
929 tty->hw_stopped = 1;
930 sdio_uart_stop_tx(port);
931 }
932 }
933
934 sdio_uart_release_func(port);
935}
936
937static int sdio_uart_break_ctl(struct tty_struct *tty, int break_state)
938{
939 struct sdio_uart_port *port = tty->driver_data;
940 int result;
941
942 result = sdio_uart_claim_func(port);
943 if (result != 0)
944 return result;
945
946 if (break_state == -1)
947 port->lcr |= UART_LCR_SBC;
948 else
949 port->lcr &= ~UART_LCR_SBC;
950 sdio_out(port, UART_LCR, port->lcr);
951
952 sdio_uart_release_func(port);
953 return 0;
954}
955
956static int sdio_uart_tiocmget(struct tty_struct *tty)
957{
958 struct sdio_uart_port *port = tty->driver_data;
959 int result;
960
961 result = sdio_uart_claim_func(port);
962 if (!result) {
963 result = port->mctrl | sdio_uart_get_mctrl(port);
964 sdio_uart_release_func(port);
965 }
966
967 return result;
968}
969
970static int sdio_uart_tiocmset(struct tty_struct *tty,
971 unsigned int set, unsigned int clear)
972{
973 struct sdio_uart_port *port = tty->driver_data;
974 int result;
975
976 result = sdio_uart_claim_func(port);
977 if (!result) {
978 sdio_uart_update_mctrl(port, set, clear);
979 sdio_uart_release_func(port);
980 }
981
982 return result;
983}
984
985static int sdio_uart_proc_show(struct seq_file *m, void *v)
986{
987 int i;
988
989 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
990 "", "", "");
991 for (i = 0; i < UART_NR; i++) {
992 struct sdio_uart_port *port = sdio_uart_port_get(i);
993 if (port) {
994 seq_printf(m, "%d: uart:SDIO", i);
995 if (capable(CAP_SYS_ADMIN)) {
996 seq_printf(m, " tx:%d rx:%d",
997 port->icount.tx, port->icount.rx);
998 if (port->icount.frame)
999 seq_printf(m, " fe:%d",
1000 port->icount.frame);
1001 if (port->icount.parity)
1002 seq_printf(m, " pe:%d",
1003 port->icount.parity);
1004 if (port->icount.brk)
1005 seq_printf(m, " brk:%d",
1006 port->icount.brk);
1007 if (port->icount.overrun)
1008 seq_printf(m, " oe:%d",
1009 port->icount.overrun);
1010 if (port->icount.cts)
1011 seq_printf(m, " cts:%d",
1012 port->icount.cts);
1013 if (port->icount.dsr)
1014 seq_printf(m, " dsr:%d",
1015 port->icount.dsr);
1016 if (port->icount.rng)
1017 seq_printf(m, " rng:%d",
1018 port->icount.rng);
1019 if (port->icount.dcd)
1020 seq_printf(m, " dcd:%d",
1021 port->icount.dcd);
1022 }
1023 sdio_uart_port_put(port);
1024 seq_putc(m, '\n');
1025 }
1026 }
1027 return 0;
1028}
1029
1030static int sdio_uart_proc_open(struct inode *inode, struct file *file)
1031{
1032 return single_open(file, sdio_uart_proc_show, NULL);
1033}
1034
1035static const struct file_operations sdio_uart_proc_fops = {
1036 .owner = THIS_MODULE,
1037 .open = sdio_uart_proc_open,
1038 .read = seq_read,
1039 .llseek = seq_lseek,
1040 .release = single_release,
1041};
1042
1043static const struct tty_port_operations sdio_uart_port_ops = {
1044 .dtr_rts = uart_dtr_rts,
1045 .carrier_raised = uart_carrier_raised,
1046 .shutdown = sdio_uart_shutdown,
1047 .activate = sdio_uart_activate,
1048};
1049
1050static const struct tty_operations sdio_uart_ops = {
1051 .open = sdio_uart_open,
1052 .close = sdio_uart_close,
1053 .write = sdio_uart_write,
1054 .write_room = sdio_uart_write_room,
1055 .chars_in_buffer = sdio_uart_chars_in_buffer,
1056 .send_xchar = sdio_uart_send_xchar,
1057 .throttle = sdio_uart_throttle,
1058 .unthrottle = sdio_uart_unthrottle,
1059 .set_termios = sdio_uart_set_termios,
1060 .hangup = sdio_uart_hangup,
1061 .break_ctl = sdio_uart_break_ctl,
1062 .tiocmget = sdio_uart_tiocmget,
1063 .tiocmset = sdio_uart_tiocmset,
1064 .install = sdio_uart_install,
1065 .cleanup = sdio_uart_cleanup,
1066 .proc_fops = &sdio_uart_proc_fops,
1067};
1068
1069static struct tty_driver *sdio_uart_tty_driver;
1070
1071static int sdio_uart_probe(struct sdio_func *func,
1072 const struct sdio_device_id *id)
1073{
1074 struct sdio_uart_port *port;
1075 int ret;
1076
1077 port = kzalloc(sizeof(struct sdio_uart_port), GFP_KERNEL);
1078 if (!port)
1079 return -ENOMEM;
1080
1081 if (func->class == SDIO_CLASS_UART) {
1082 pr_warning("%s: need info on UART class basic setup\n",
1083 sdio_func_id(func));
1084 kfree(port);
1085 return -ENOSYS;
1086 } else if (func->class == SDIO_CLASS_GPS) {
1087 /*
1088 * We need tuple 0x91. It contains SUBTPL_SIOREG
1089 * and SUBTPL_RCVCAPS.
1090 */
1091 struct sdio_func_tuple *tpl;
1092 for (tpl = func->tuples; tpl; tpl = tpl->next) {
1093 if (tpl->code != 0x91)
1094 continue;
1095 if (tpl->size < 10)
1096 continue;
1097 if (tpl->data[1] == 0) /* SUBTPL_SIOREG */
1098 break;
1099 }
1100 if (!tpl) {
1101 pr_warning(
1102 "%s: can't find tuple 0x91 subtuple 0 (SUBTPL_SIOREG) for GPS class\n",
1103 sdio_func_id(func));
1104 kfree(port);
1105 return -EINVAL;
1106 }
1107 pr_debug("%s: Register ID = 0x%02x, Exp ID = 0x%02x\n",
1108 sdio_func_id(func), tpl->data[2], tpl->data[3]);
1109 port->regs_offset = (tpl->data[4] << 0) |
1110 (tpl->data[5] << 8) |
1111 (tpl->data[6] << 16);
1112 pr_debug("%s: regs offset = 0x%x\n",
1113 sdio_func_id(func), port->regs_offset);
1114 port->uartclk = tpl->data[7] * 115200;
1115 if (port->uartclk == 0)
1116 port->uartclk = 115200;
1117 pr_debug("%s: clk %d baudcode %u 4800-div %u\n",
1118 sdio_func_id(func), port->uartclk,
1119 tpl->data[7], tpl->data[8] | (tpl->data[9] << 8));
1120 } else {
1121 kfree(port);
1122 return -EINVAL;
1123 }
1124
1125 port->func = func;
1126 sdio_set_drvdata(func, port);
1127 tty_port_init(&port->port);
1128 port->port.ops = &sdio_uart_port_ops;
1129
1130 ret = sdio_uart_add_port(port);
1131 if (ret) {
1132 kfree(port);
1133 } else {
1134 struct device *dev;
1135 dev = tty_register_device(sdio_uart_tty_driver,
1136 port->index, &func->dev);
1137 if (IS_ERR(dev)) {
1138 sdio_uart_port_remove(port);
1139 ret = PTR_ERR(dev);
1140 }
1141 }
1142
1143 return ret;
1144}
1145
1146static void sdio_uart_remove(struct sdio_func *func)
1147{
1148 struct sdio_uart_port *port = sdio_get_drvdata(func);
1149
1150 tty_unregister_device(sdio_uart_tty_driver, port->index);
1151 sdio_uart_port_remove(port);
1152}
1153
1154static const struct sdio_device_id sdio_uart_ids[] = {
1155 { SDIO_DEVICE_CLASS(SDIO_CLASS_UART) },
1156 { SDIO_DEVICE_CLASS(SDIO_CLASS_GPS) },
1157 { /* end: all zeroes */ },
1158};
1159
1160MODULE_DEVICE_TABLE(sdio, sdio_uart_ids);
1161
1162static struct sdio_driver sdio_uart_driver = {
1163 .probe = sdio_uart_probe,
1164 .remove = sdio_uart_remove,
1165 .name = "sdio_uart",
1166 .id_table = sdio_uart_ids,
1167};
1168
1169static int __init sdio_uart_init(void)
1170{
1171 int ret;
1172 struct tty_driver *tty_drv;
1173
1174 sdio_uart_tty_driver = tty_drv = alloc_tty_driver(UART_NR);
1175 if (!tty_drv)
1176 return -ENOMEM;
1177
1178 tty_drv->driver_name = "sdio_uart";
1179 tty_drv->name = "ttySDIO";
1180 tty_drv->major = 0; /* dynamically allocated */
1181 tty_drv->minor_start = 0;
1182 tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
1183 tty_drv->subtype = SERIAL_TYPE_NORMAL;
1184 tty_drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1185 tty_drv->init_termios = tty_std_termios;
1186 tty_drv->init_termios.c_cflag = B4800 | CS8 | CREAD | HUPCL | CLOCAL;
1187 tty_drv->init_termios.c_ispeed = 4800;
1188 tty_drv->init_termios.c_ospeed = 4800;
1189 tty_set_operations(tty_drv, &sdio_uart_ops);
1190
1191 ret = tty_register_driver(tty_drv);
1192 if (ret)
1193 goto err1;
1194
1195 ret = sdio_register_driver(&sdio_uart_driver);
1196 if (ret)
1197 goto err2;
1198
1199 return 0;
1200
1201err2:
1202 tty_unregister_driver(tty_drv);
1203err1:
1204 put_tty_driver(tty_drv);
1205 return ret;
1206}
1207
1208static void __exit sdio_uart_exit(void)
1209{
1210 sdio_unregister_driver(&sdio_uart_driver);
1211 tty_unregister_driver(sdio_uart_tty_driver);
1212 put_tty_driver(sdio_uart_tty_driver);
1213}
1214
1215module_init(sdio_uart_init);
1216module_exit(sdio_uart_exit);
1217
1218MODULE_AUTHOR("Nicolas Pitre");
1219MODULE_LICENSE("GPL");