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[ARM] pxa: Gumstix Verdex PCMCIA support
[linux-2.6/verdex.git] / drivers / mmc / card / sdio_uart.c
blob36a8d53ad2a2ba90cf7b5d7dd3fffb647545a1d1
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 kref kref;
77 struct tty_struct *tty;
78 unsigned int index;
79 unsigned int opened;
80 struct mutex open_lock;
81 struct sdio_func *func;
82 struct mutex func_lock;
83 struct task_struct *in_sdio_uart_irq;
84 unsigned int regs_offset;
85 struct circ_buf xmit;
86 spinlock_t write_lock;
87 struct uart_icount icount;
88 unsigned int uartclk;
89 unsigned int mctrl;
90 unsigned int read_status_mask;
91 unsigned int ignore_status_mask;
92 unsigned char x_char;
93 unsigned char ier;
94 unsigned char lcr;
95 };
96
97 static struct sdio_uart_port *sdio_uart_table[UART_NR];
98 static DEFINE_SPINLOCK(sdio_uart_table_lock);
99
100 static int sdio_uart_add_port(struct sdio_uart_port *port)
101 {
102 int index, ret = -EBUSY;
103
104 kref_init(&port->kref);
105 mutex_init(&port->open_lock);
106 mutex_init(&port->func_lock);
107 spin_lock_init(&port->write_lock);
108
109 spin_lock(&sdio_uart_table_lock);
110 for (index = 0; index < UART_NR; index++) {
111 if (!sdio_uart_table[index]) {
112 port->index = index;
113 sdio_uart_table[index] = port;
114 ret = 0;
115 break;
116 }
117 }
118 spin_unlock(&sdio_uart_table_lock);
119
120 return ret;
121 }
122
123 static struct sdio_uart_port *sdio_uart_port_get(unsigned index)
124 {
125 struct sdio_uart_port *port;
126
127 if (index >= UART_NR)
128 return NULL;
129
130 spin_lock(&sdio_uart_table_lock);
131 port = sdio_uart_table[index];
132 if (port)
133 kref_get(&port->kref);
134 spin_unlock(&sdio_uart_table_lock);
135
136 return port;
137 }
138
139 static void sdio_uart_port_destroy(struct kref *kref)
140 {
141 struct sdio_uart_port *port =
142 container_of(kref, struct sdio_uart_port, kref);
143 kfree(port);
144 }
145
146 static void sdio_uart_port_put(struct sdio_uart_port *port)
147 {
148 kref_put(&port->kref, sdio_uart_port_destroy);
149 }
150
151 static void sdio_uart_port_remove(struct sdio_uart_port *port)
152 {
153 struct sdio_func *func;
154
155 BUG_ON(sdio_uart_table[port->index] != port);
156
157 spin_lock(&sdio_uart_table_lock);
158 sdio_uart_table[port->index] = NULL;
159 spin_unlock(&sdio_uart_table_lock);
160
161 /*
162 * We're killing a port that potentially still is in use by
163 * the tty layer. Be careful to prevent any further access
164 * to the SDIO function and arrange for the tty layer to
165 * give up on that port ASAP.
166 * Beware: the lock ordering is critical.
167 */
168 mutex_lock(&port->open_lock);
169 mutex_lock(&port->func_lock);
170 func = port->func;
171 sdio_claim_host(func);
172 port->func = NULL;
173 mutex_unlock(&port->func_lock);
174 if (port->opened)
175 tty_hangup(port->tty);
176 mutex_unlock(&port->open_lock);
177 sdio_release_irq(func);
178 sdio_disable_func(func);
179 sdio_release_host(func);
180
181 sdio_uart_port_put(port);
182 }
183
184 static int sdio_uart_claim_func(struct sdio_uart_port *port)
185 {
186 mutex_lock(&port->func_lock);
187 if (unlikely(!port->func)) {
188 mutex_unlock(&port->func_lock);
189 return -ENODEV;
190 }
191 if (likely(port->in_sdio_uart_irq != current))
192 sdio_claim_host(port->func);
193 mutex_unlock(&port->func_lock);
194 return 0;
195 }
196
197 static inline void sdio_uart_release_func(struct sdio_uart_port *port)
198 {
199 if (likely(port->in_sdio_uart_irq != current))
200 sdio_release_host(port->func);
201 }
202
203 static inline unsigned int sdio_in(struct sdio_uart_port *port, int offset)
204 {
205 unsigned char c;
206 c = sdio_readb(port->func, port->regs_offset + offset, NULL);
207 return c;
208 }
209
210 static inline void sdio_out(struct sdio_uart_port *port, int offset, int value)
211 {
212 sdio_writeb(port->func, value, port->regs_offset + offset, NULL);
213 }
214
215 static unsigned int sdio_uart_get_mctrl(struct sdio_uart_port *port)
216 {
217 unsigned char status;
218 unsigned int ret;
219
220 status = sdio_in(port, UART_MSR);
221
222 ret = 0;
223 if (status & UART_MSR_DCD)
224 ret |= TIOCM_CAR;
225 if (status & UART_MSR_RI)
226 ret |= TIOCM_RNG;
227 if (status & UART_MSR_DSR)
228 ret |= TIOCM_DSR;
229 if (status & UART_MSR_CTS)
230 ret |= TIOCM_CTS;
231 return ret;
232 }
233
234 static void sdio_uart_write_mctrl(struct sdio_uart_port *port, unsigned int mctrl)
235 {
236 unsigned char mcr = 0;
237
238 if (mctrl & TIOCM_RTS)
239 mcr |= UART_MCR_RTS;
240 if (mctrl & TIOCM_DTR)
241 mcr |= UART_MCR_DTR;
242 if (mctrl & TIOCM_OUT1)
243 mcr |= UART_MCR_OUT1;
244 if (mctrl & TIOCM_OUT2)
245 mcr |= UART_MCR_OUT2;
246 if (mctrl & TIOCM_LOOP)
247 mcr |= UART_MCR_LOOP;
248
249 sdio_out(port, UART_MCR, mcr);
250 }
251
252 static inline void sdio_uart_update_mctrl(struct sdio_uart_port *port,
253 unsigned int set, unsigned int clear)
254 {
255 unsigned int old;
256
257 old = port->mctrl;
258 port->mctrl = (old & ~clear) | set;
259 if (old != port->mctrl)
260 sdio_uart_write_mctrl(port, port->mctrl);
261 }
262
263 #define sdio_uart_set_mctrl(port, x) sdio_uart_update_mctrl(port, x, 0)
264 #define sdio_uart_clear_mctrl(port, x) sdio_uart_update_mctrl(port, 0, x)
265
266 static void sdio_uart_change_speed(struct sdio_uart_port *port,
267 struct ktermios *termios,
268 struct ktermios *old)
269 {
270 unsigned char cval, fcr = 0;
271 unsigned int baud, quot;
272
273 switch (termios->c_cflag & CSIZE) {
274 case CS5:
275 cval = UART_LCR_WLEN5;
276 break;
277 case CS6:
278 cval = UART_LCR_WLEN6;
279 break;
280 case CS7:
281 cval = UART_LCR_WLEN7;
282 break;
283 default:
284 case CS8:
285 cval = UART_LCR_WLEN8;
286 break;
287 }
288
289 if (termios->c_cflag & CSTOPB)
290 cval |= UART_LCR_STOP;
291 if (termios->c_cflag & PARENB)
292 cval |= UART_LCR_PARITY;
293 if (!(termios->c_cflag & PARODD))
294 cval |= UART_LCR_EPAR;
295
296 for (;;) {
297 baud = tty_termios_baud_rate(termios);
298 if (baud == 0)
299 baud = 9600; /* Special case: B0 rate. */
300 if (baud <= port->uartclk)
301 break;
302 /*
303 * Oops, the quotient was zero. Try again with the old
304 * baud rate if possible, otherwise default to 9600.
305 */
306 termios->c_cflag &= ~CBAUD;
307 if (old) {
308 termios->c_cflag |= old->c_cflag & CBAUD;
309 old = NULL;
310 } else
311 termios->c_cflag |= B9600;
312 }
313 quot = (2 * port->uartclk + baud) / (2 * baud);
314
315 if (baud < 2400)
316 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
317 else
318 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10;
319
320 port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
321 if (termios->c_iflag & INPCK)
322 port->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
323 if (termios->c_iflag & (BRKINT | PARMRK))
324 port->read_status_mask |= UART_LSR_BI;
325
326 /*
327 * Characters to ignore
328 */
329 port->ignore_status_mask = 0;
330 if (termios->c_iflag & IGNPAR)
331 port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
332 if (termios->c_iflag & IGNBRK) {
333 port->ignore_status_mask |= UART_LSR_BI;
334 /*
335 * If we're ignoring parity and break indicators,
336 * ignore overruns too (for real raw support).
337 */
338 if (termios->c_iflag & IGNPAR)
339 port->ignore_status_mask |= UART_LSR_OE;
340 }
341
342 /*
343 * ignore all characters if CREAD is not set
344 */
345 if ((termios->c_cflag & CREAD) == 0)
346 port->ignore_status_mask |= UART_LSR_DR;
347
348 /*
349 * CTS flow control flag and modem status interrupts
350 */
351 port->ier &= ~UART_IER_MSI;
352 if ((termios->c_cflag & CRTSCTS) || !(termios->c_cflag & CLOCAL))
353 port->ier |= UART_IER_MSI;
354
355 port->lcr = cval;
356
357 sdio_out(port, UART_IER, port->ier);
358 sdio_out(port, UART_LCR, cval | UART_LCR_DLAB);
359 sdio_out(port, UART_DLL, quot & 0xff);
360 sdio_out(port, UART_DLM, quot >> 8);
361 sdio_out(port, UART_LCR, cval);
362 sdio_out(port, UART_FCR, fcr);
363
364 sdio_uart_write_mctrl(port, port->mctrl);
365 }
366
367 static void sdio_uart_start_tx(struct sdio_uart_port *port)
368 {
369 if (!(port->ier & UART_IER_THRI)) {
370 port->ier |= UART_IER_THRI;
371 sdio_out(port, UART_IER, port->ier);
372 }
373 }
374
375 static void sdio_uart_stop_tx(struct sdio_uart_port *port)
376 {
377 if (port->ier & UART_IER_THRI) {
378 port->ier &= ~UART_IER_THRI;
379 sdio_out(port, UART_IER, port->ier);
380 }
381 }
382
383 static void sdio_uart_stop_rx(struct sdio_uart_port *port)
384 {
385 port->ier &= ~UART_IER_RLSI;
386 port->read_status_mask &= ~UART_LSR_DR;
387 sdio_out(port, UART_IER, port->ier);
388 }
389
390 static void sdio_uart_receive_chars(struct sdio_uart_port *port, unsigned int *status)
391 {
392 struct tty_struct *tty = port->tty;
393 unsigned int ch, flag;
394 int max_count = 256;
395
396 do {
397 ch = sdio_in(port, UART_RX);
398 flag = TTY_NORMAL;
399 port->icount.rx++;
400
401 if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
402 UART_LSR_FE | UART_LSR_OE))) {
403 /*
404 * For statistics only
405 */
406 if (*status & UART_LSR_BI) {
407 *status &= ~(UART_LSR_FE | UART_LSR_PE);
408 port->icount.brk++;
409 } else if (*status & UART_LSR_PE)
410 port->icount.parity++;
411 else if (*status & UART_LSR_FE)
412 port->icount.frame++;
413 if (*status & UART_LSR_OE)
414 port->icount.overrun++;
415
416 /*
417 * Mask off conditions which should be ignored.
418 */
419 *status &= port->read_status_mask;
420 if (*status & UART_LSR_BI) {
421 flag = TTY_BREAK;
422 } else if (*status & UART_LSR_PE)
423 flag = TTY_PARITY;
424 else if (*status & UART_LSR_FE)
425 flag = TTY_FRAME;
426 }
427
428 if ((*status & port->ignore_status_mask & ~UART_LSR_OE) == 0)
429 tty_insert_flip_char(tty, ch, flag);
430
431 /*
432 * Overrun is special. Since it's reported immediately,
433 * it doesn't affect the current character.
434 */
435 if (*status & ~port->ignore_status_mask & UART_LSR_OE)
436 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
437
438 *status = sdio_in(port, UART_LSR);
439 } while ((*status & UART_LSR_DR) && (max_count-- > 0));
440 tty_flip_buffer_push(tty);
441 }
442
443 static void sdio_uart_transmit_chars(struct sdio_uart_port *port)
444 {
445 struct circ_buf *xmit = &port->xmit;
446 int count;
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 if (circ_empty(xmit) || port->tty->stopped || port->tty->hw_stopped) {
455 sdio_uart_stop_tx(port);
456 return;
457 }
458
459 count = 16;
460 do {
461 sdio_out(port, UART_TX, xmit->buf[xmit->tail]);
462 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
463 port->icount.tx++;
464 if (circ_empty(xmit))
465 break;
466 } while (--count > 0);
467
468 if (circ_chars_pending(xmit) < WAKEUP_CHARS)
469 tty_wakeup(port->tty);
470
471 if (circ_empty(xmit))
472 sdio_uart_stop_tx(port);
473 }
474
475 static void sdio_uart_check_modem_status(struct sdio_uart_port *port)
476 {
477 int status;
478
479 status = sdio_in(port, UART_MSR);
480
481 if ((status & UART_MSR_ANY_DELTA) == 0)
482 return;
483
484 if (status & UART_MSR_TERI)
485 port->icount.rng++;
486 if (status & UART_MSR_DDSR)
487 port->icount.dsr++;
488 if (status & UART_MSR_DDCD)
489 port->icount.dcd++;
490 if (status & UART_MSR_DCTS) {
491 port->icount.cts++;
492 if (port->tty->termios->c_cflag & CRTSCTS) {
493 int cts = (status & UART_MSR_CTS);
494 if (port->tty->hw_stopped) {
495 if (cts) {
496 port->tty->hw_stopped = 0;
497 sdio_uart_start_tx(port);
498 tty_wakeup(port->tty);
499 }
500 } else {
501 if (!cts) {
502 port->tty->hw_stopped = 1;
503 sdio_uart_stop_tx(port);
504 }
505 }
506 }
507 }
508 }
509
510 /*
511 * This handles the interrupt from one port.
512 */
513 static void sdio_uart_irq(struct sdio_func *func)
514 {
515 struct sdio_uart_port *port = sdio_get_drvdata(func);
516 unsigned int iir, lsr;
517
518 /*
519 * In a few places sdio_uart_irq() is called directly instead of
520 * waiting for the actual interrupt to be raised and the SDIO IRQ
521 * thread scheduled in order to reduce latency. However, some
522 * interaction with the tty core may end up calling us back
523 * (serial echo, flow control, etc.) through those same places
524 * causing undesirable effects. Let's stop the recursion here.
525 */
526 if (unlikely(port->in_sdio_uart_irq == current))
527 return;
528
529 iir = sdio_in(port, UART_IIR);
530 if (iir & UART_IIR_NO_INT)
531 return;
532
533 port->in_sdio_uart_irq = current;
534 lsr = sdio_in(port, UART_LSR);
535 if (lsr & UART_LSR_DR)
536 sdio_uart_receive_chars(port, &lsr);
537 sdio_uart_check_modem_status(port);
538 if (lsr & UART_LSR_THRE)
539 sdio_uart_transmit_chars(port);
540 port->in_sdio_uart_irq = NULL;
541 }
542
543 static int sdio_uart_startup(struct sdio_uart_port *port)
544 {
545 unsigned long page;
546 int ret;
547
548 /*
549 * Set the TTY IO error marker - we will only clear this
550 * once we have successfully opened the port.
551 */
552 set_bit(TTY_IO_ERROR, &port->tty->flags);
553
554 /* Initialise and allocate the transmit buffer. */
555 page = __get_free_page(GFP_KERNEL);
556 if (!page)
557 return -ENOMEM;
558 port->xmit.buf = (unsigned char *)page;
559 circ_clear(&port->xmit);
560
561 ret = sdio_uart_claim_func(port);
562 if (ret)
563 goto err1;
564 ret = sdio_enable_func(port->func);
565 if (ret)
566 goto err2;
567 ret = sdio_claim_irq(port->func, sdio_uart_irq);
568 if (ret)
569 goto err3;
570
571 /*
572 * Clear the FIFO buffers and disable them.
573 * (they will be reenabled in sdio_change_speed())
574 */
575 sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO);
576 sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO |
577 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
578 sdio_out(port, UART_FCR, 0);
579
580 /*
581 * Clear the interrupt registers.
582 */
583 (void) sdio_in(port, UART_LSR);
584 (void) sdio_in(port, UART_RX);
585 (void) sdio_in(port, UART_IIR);
586 (void) sdio_in(port, UART_MSR);
587
588 /*
589 * Now, initialize the UART
590 */
591 sdio_out(port, UART_LCR, UART_LCR_WLEN8);
592
593 port->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
594 port->mctrl = TIOCM_OUT2;
595
596 sdio_uart_change_speed(port, port->tty->termios, NULL);
597
598 if (port->tty->termios->c_cflag & CBAUD)
599 sdio_uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
600
601 if (port->tty->termios->c_cflag & CRTSCTS)
602 if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS))
603 port->tty->hw_stopped = 1;
604
605 clear_bit(TTY_IO_ERROR, &port->tty->flags);
606
607 /* Kick the IRQ handler once while we're still holding the host lock */
608 sdio_uart_irq(port->func);
609
610 sdio_uart_release_func(port);
611 return 0;
612
613 err3:
614 sdio_disable_func(port->func);
615 err2:
616 sdio_uart_release_func(port);
617 err1:
618 free_page((unsigned long)port->xmit.buf);
619 return ret;
620 }
621
622 static void sdio_uart_shutdown(struct sdio_uart_port *port)
623 {
624 int ret;
625
626 ret = sdio_uart_claim_func(port);
627 if (ret)
628 goto skip;
629
630 sdio_uart_stop_rx(port);
631
632 /* TODO: wait here for TX FIFO to drain */
633
634 /* Turn off DTR and RTS early. */
635 if (port->tty->termios->c_cflag & HUPCL)
636 sdio_uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
637
638 /* Disable interrupts from this port */
639 sdio_release_irq(port->func);
640 port->ier = 0;
641 sdio_out(port, UART_IER, 0);
642
643 sdio_uart_clear_mctrl(port, TIOCM_OUT2);
644
645 /* Disable break condition and FIFOs. */
646 port->lcr &= ~UART_LCR_SBC;
647 sdio_out(port, UART_LCR, port->lcr);
648 sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO |
649 UART_FCR_CLEAR_RCVR |
650 UART_FCR_CLEAR_XMIT);
651 sdio_out(port, UART_FCR, 0);
652
653 sdio_disable_func(port->func);
654
655 sdio_uart_release_func(port);
656
657 skip:
658 /* Free the transmit buffer page. */
659 free_page((unsigned long)port->xmit.buf);
660 }
661
662 static int sdio_uart_open (struct tty_struct *tty, struct file * filp)
663 {
664 struct sdio_uart_port *port;
665 int ret;
666
667 port = sdio_uart_port_get(tty->index);
668 if (!port)
669 return -ENODEV;
670
671 mutex_lock(&port->open_lock);
672
673 /*
674 * Make sure not to mess up with a dead port
675 * which has not been closed yet.
676 */
677 if (tty->driver_data && tty->driver_data != port) {
678 mutex_unlock(&port->open_lock);
679 sdio_uart_port_put(port);
680 return -EBUSY;
681 }
682
683 if (!port->opened) {
684 tty->driver_data = port;
685 port->tty = tty;
686 ret = sdio_uart_startup(port);
687 if (ret) {
688 tty->driver_data = NULL;
689 port->tty = NULL;
690 mutex_unlock(&port->open_lock);
691 sdio_uart_port_put(port);
692 return ret;
693 }
694 }
695 port->opened++;
696 mutex_unlock(&port->open_lock);
697 return 0;
698 }
699
700 static void sdio_uart_close(struct tty_struct *tty, struct file * filp)
701 {
702 struct sdio_uart_port *port = tty->driver_data;
703
704 if (!port)
705 return;
706
707 mutex_lock(&port->open_lock);
708 BUG_ON(!port->opened);
709
710 /*
711 * This is messy. The tty layer calls us even when open()
712 * returned an error. Ignore this close request if tty->count
713 * is larger than port->count.
714 */
715 if (tty->count > port->opened) {
716 mutex_unlock(&port->open_lock);
717 return;
718 }
719
720 if (--port->opened == 0) {
721 tty->closing = 1;
722 sdio_uart_shutdown(port);
723 tty_ldisc_flush(tty);
724 port->tty = NULL;
725 tty->driver_data = NULL;
726 tty->closing = 0;
727 }
728 mutex_unlock(&port->open_lock);
729 sdio_uart_port_put(port);
730 }
731
732 static int sdio_uart_write(struct tty_struct * tty, const unsigned char *buf,
733 int count)
734 {
735 struct sdio_uart_port *port = tty->driver_data;
736 struct circ_buf *circ = &port->xmit;
737 int c, ret = 0;
738
739 if (!port->func)
740 return -ENODEV;
741
742 spin_lock(&port->write_lock);
743 while (1) {
744 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
745 if (count < c)
746 c = count;
747 if (c <= 0)
748 break;
749 memcpy(circ->buf + circ->head, buf, c);
750 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
751 buf += c;
752 count -= c;
753 ret += c;
754 }
755 spin_unlock(&port->write_lock);
756
757 if ( !(port->ier & UART_IER_THRI)) {
758 int err = sdio_uart_claim_func(port);
759 if (!err) {
760 sdio_uart_start_tx(port);
761 sdio_uart_irq(port->func);
762 sdio_uart_release_func(port);
763 } else
764 ret = err;
765 }
766
767 return ret;
768 }
769
770 static int sdio_uart_write_room(struct tty_struct *tty)
771 {
772 struct sdio_uart_port *port = tty->driver_data;
773 return port ? circ_chars_free(&port->xmit) : 0;
774 }
775
776 static int sdio_uart_chars_in_buffer(struct tty_struct *tty)
777 {
778 struct sdio_uart_port *port = tty->driver_data;
779 return port ? circ_chars_pending(&port->xmit) : 0;
780 }
781
782 static void sdio_uart_send_xchar(struct tty_struct *tty, char ch)
783 {
784 struct sdio_uart_port *port = tty->driver_data;
785
786 port->x_char = ch;
787 if (ch && !(port->ier & UART_IER_THRI)) {
788 if (sdio_uart_claim_func(port) != 0)
789 return;
790 sdio_uart_start_tx(port);
791 sdio_uart_irq(port->func);
792 sdio_uart_release_func(port);
793 }
794 }
795
796 static void sdio_uart_throttle(struct tty_struct *tty)
797 {
798 struct sdio_uart_port *port = tty->driver_data;
799
800 if (!I_IXOFF(tty) && !(tty->termios->c_cflag & CRTSCTS))
801 return;
802
803 if (sdio_uart_claim_func(port) != 0)
804 return;
805
806 if (I_IXOFF(tty)) {
807 port->x_char = STOP_CHAR(tty);
808 sdio_uart_start_tx(port);
809 }
810
811 if (tty->termios->c_cflag & CRTSCTS)
812 sdio_uart_clear_mctrl(port, TIOCM_RTS);
813
814 sdio_uart_irq(port->func);
815 sdio_uart_release_func(port);
816 }
817
818 static void sdio_uart_unthrottle(struct tty_struct *tty)
819 {
820 struct sdio_uart_port *port = tty->driver_data;
821
822 if (!I_IXOFF(tty) && !(tty->termios->c_cflag & CRTSCTS))
823 return;
824
825 if (sdio_uart_claim_func(port) != 0)
826 return;
827
828 if (I_IXOFF(tty)) {
829 if (port->x_char) {
830 port->x_char = 0;
831 } else {
832 port->x_char = START_CHAR(tty);
833 sdio_uart_start_tx(port);
834 }
835 }
836
837 if (tty->termios->c_cflag & CRTSCTS)
838 sdio_uart_set_mctrl(port, TIOCM_RTS);
839
840 sdio_uart_irq(port->func);
841 sdio_uart_release_func(port);
842 }
843
844 static void sdio_uart_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
845 {
846 struct sdio_uart_port *port = tty->driver_data;
847 unsigned int cflag = tty->termios->c_cflag;
848
849 #define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
850
851 if ((cflag ^ old_termios->c_cflag) == 0 &&
852 RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0)
853 return;
854
855 if (sdio_uart_claim_func(port) != 0)
856 return;
857
858 sdio_uart_change_speed(port, tty->termios, old_termios);
859
860 /* Handle transition to B0 status */
861 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
862 sdio_uart_clear_mctrl(port, TIOCM_RTS | TIOCM_DTR);
863
864 /* Handle transition away from B0 status */
865 if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
866 unsigned int mask = TIOCM_DTR;
867 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
868 mask |= TIOCM_RTS;
869 sdio_uart_set_mctrl(port, mask);
870 }
871
872 /* Handle turning off CRTSCTS */
873 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
874 tty->hw_stopped = 0;
875 sdio_uart_start_tx(port);
876 }
877
878 /* Handle turning on CRTSCTS */
879 if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
880 if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS)) {
881 tty->hw_stopped = 1;
882 sdio_uart_stop_tx(port);
883 }
884 }
885
886 sdio_uart_release_func(port);
887 }
888
889 static int sdio_uart_break_ctl(struct tty_struct *tty, int break_state)
890 {
891 struct sdio_uart_port *port = tty->driver_data;
892 int result;
893
894 result = sdio_uart_claim_func(port);
895 if (result != 0)
896 return result;
897
898 if (break_state == -1)
899 port->lcr |= UART_LCR_SBC;
900 else
901 port->lcr &= ~UART_LCR_SBC;
902 sdio_out(port, UART_LCR, port->lcr);
903
904 sdio_uart_release_func(port);
905 return 0;
906 }
907
908 static int sdio_uart_tiocmget(struct tty_struct *tty, struct file *file)
909 {
910 struct sdio_uart_port *port = tty->driver_data;
911 int result;
912
913 result = sdio_uart_claim_func(port);
914 if (!result) {
915 result = port->mctrl | sdio_uart_get_mctrl(port);
916 sdio_uart_release_func(port);
917 }
918
919 return result;
920 }
921
922 static int sdio_uart_tiocmset(struct tty_struct *tty, struct file *file,
923 unsigned int set, unsigned int clear)
924 {
925 struct sdio_uart_port *port = tty->driver_data;
926 int result;
927
928 result =sdio_uart_claim_func(port);
929 if(!result) {
930 sdio_uart_update_mctrl(port, set, clear);
931 sdio_uart_release_func(port);
932 }
933
934 return result;
935 }
936
937 static int sdio_uart_proc_show(struct seq_file *m, void *v)
938 {
939 int i;
940
941 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
942 "", "", "");
943 for (i = 0; i < UART_NR; i++) {
944 struct sdio_uart_port *port = sdio_uart_port_get(i);
945 if (port) {
946 seq_printf(m, "%d: uart:SDIO", i);
947 if(capable(CAP_SYS_ADMIN)) {
948 seq_printf(m, " tx:%d rx:%d",
949 port->icount.tx, port->icount.rx);
950 if (port->icount.frame)
951 seq_printf(m, " fe:%d",
952 port->icount.frame);
953 if (port->icount.parity)
954 seq_printf(m, " pe:%d",
955 port->icount.parity);
956 if (port->icount.brk)
957 seq_printf(m, " brk:%d",
958 port->icount.brk);
959 if (port->icount.overrun)
960 seq_printf(m, " oe:%d",
961 port->icount.overrun);
962 if (port->icount.cts)
963 seq_printf(m, " cts:%d",
964 port->icount.cts);
965 if (port->icount.dsr)
966 seq_printf(m, " dsr:%d",
967 port->icount.dsr);
968 if (port->icount.rng)
969 seq_printf(m, " rng:%d",
970 port->icount.rng);
971 if (port->icount.dcd)
972 seq_printf(m, " dcd:%d",
973 port->icount.dcd);
974 }
975 sdio_uart_port_put(port);
976 seq_putc(m, '\n');
977 }
978 }
979 return 0;
980 }
981
982 static int sdio_uart_proc_open(struct inode *inode, struct file *file)
983 {
984 return single_open(file, sdio_uart_proc_show, NULL);
985 }
986
987 static const struct file_operations sdio_uart_proc_fops = {
988 .owner = THIS_MODULE,
989 .open = sdio_uart_proc_open,
990 .read = seq_read,
991 .llseek = seq_lseek,
992 .release = single_release,
993 };
994
995 static const struct tty_operations sdio_uart_ops = {
996 .open = sdio_uart_open,
997 .close = sdio_uart_close,
998 .write = sdio_uart_write,
999 .write_room = sdio_uart_write_room,
1000 .chars_in_buffer = sdio_uart_chars_in_buffer,
1001 .send_xchar = sdio_uart_send_xchar,
1002 .throttle = sdio_uart_throttle,
1003 .unthrottle = sdio_uart_unthrottle,
1004 .set_termios = sdio_uart_set_termios,
1005 .break_ctl = sdio_uart_break_ctl,
1006 .tiocmget = sdio_uart_tiocmget,
1007 .tiocmset = sdio_uart_tiocmset,
1008 .proc_fops = &sdio_uart_proc_fops,
1009 };
1010
1011 static struct tty_driver *sdio_uart_tty_driver;
1012
1013 static int sdio_uart_probe(struct sdio_func *func,
1014 const struct sdio_device_id *id)
1015 {
1016 struct sdio_uart_port *port;
1017 int ret;
1018
1019 port = kzalloc(sizeof(struct sdio_uart_port), GFP_KERNEL);
1020 if (!port)
1021 return -ENOMEM;
1022
1023 if (func->class == SDIO_CLASS_UART) {
1024 printk(KERN_WARNING "%s: need info on UART class basic setup\n",
1025 sdio_func_id(func));
1026 kfree(port);
1027 return -ENOSYS;
1028 } else if (func->class == SDIO_CLASS_GPS) {
1029 /*
1030 * We need tuple 0x91. It contains SUBTPL_SIOREG
1031 * and SUBTPL_RCVCAPS.
1032 */
1033 struct sdio_func_tuple *tpl;
1034 for (tpl = func->tuples; tpl; tpl = tpl->next) {
1035 if (tpl->code != 0x91)
1036 continue;
1037 if (tpl->size < 10)
1038 continue;
1039 if (tpl->data[1] == 0) /* SUBTPL_SIOREG */
1040 break;
1041 }
1042 if (!tpl) {
1043 printk(KERN_WARNING
1044 "%s: can't find tuple 0x91 subtuple 0 (SUBTPL_SIOREG) for GPS class\n",
1045 sdio_func_id(func));
1046 kfree(port);
1047 return -EINVAL;
1048 }
1049 printk(KERN_DEBUG "%s: Register ID = 0x%02x, Exp ID = 0x%02x\n",
1050 sdio_func_id(func), tpl->data[2], tpl->data[3]);
1051 port->regs_offset = (tpl->data[4] << 0) |
1052 (tpl->data[5] << 8) |
1053 (tpl->data[6] << 16);
1054 printk(KERN_DEBUG "%s: regs offset = 0x%x\n",
1055 sdio_func_id(func), port->regs_offset);
1056 port->uartclk = tpl->data[7] * 115200;
1057 if (port->uartclk == 0)
1058 port->uartclk = 115200;
1059 printk(KERN_DEBUG "%s: clk %d baudcode %u 4800-div %u\n",
1060 sdio_func_id(func), port->uartclk,
1061 tpl->data[7], tpl->data[8] | (tpl->data[9] << 8));
1062 } else {
1063 kfree(port);
1064 return -EINVAL;
1065 }
1066
1067 port->func = func;
1068 sdio_set_drvdata(func, port);
1069
1070 ret = sdio_uart_add_port(port);
1071 if (ret) {
1072 kfree(port);
1073 } else {
1074 struct device *dev;
1075 dev = tty_register_device(sdio_uart_tty_driver, port->index, &func->dev);
1076 if (IS_ERR(dev)) {
1077 sdio_uart_port_remove(port);
1078 ret = PTR_ERR(dev);
1079 }
1080 }
1081
1082 return ret;
1083 }
1084
1085 static void sdio_uart_remove(struct sdio_func *func)
1086 {
1087 struct sdio_uart_port *port = sdio_get_drvdata(func);
1088
1089 tty_unregister_device(sdio_uart_tty_driver, port->index);
1090 sdio_uart_port_remove(port);
1091 }
1092
1093 static const struct sdio_device_id sdio_uart_ids[] = {
1094 { SDIO_DEVICE_CLASS(SDIO_CLASS_UART) },
1095 { SDIO_DEVICE_CLASS(SDIO_CLASS_GPS) },
1096 { /* end: all zeroes */ },
1097 };
1098
1099 MODULE_DEVICE_TABLE(sdio, sdio_uart_ids);
1100
1101 static struct sdio_driver sdio_uart_driver = {
1102 .probe = sdio_uart_probe,
1103 .remove = sdio_uart_remove,
1104 .name = "sdio_uart",
1105 .id_table = sdio_uart_ids,
1106 };
1107
1108 static int __init sdio_uart_init(void)
1109 {
1110 int ret;
1111 struct tty_driver *tty_drv;
1112
1113 sdio_uart_tty_driver = tty_drv = alloc_tty_driver(UART_NR);
1114 if (!tty_drv)
1115 return -ENOMEM;
1116
1117 tty_drv->owner = THIS_MODULE;
1118 tty_drv->driver_name = "sdio_uart";
1119 tty_drv->name = "ttySDIO";
1120 tty_drv->major = 0; /* dynamically allocated */
1121 tty_drv->minor_start = 0;
1122 tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
1123 tty_drv->subtype = SERIAL_TYPE_NORMAL;
1124 tty_drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1125 tty_drv->init_termios = tty_std_termios;
1126 tty_drv->init_termios.c_cflag = B4800 | CS8 | CREAD | HUPCL | CLOCAL;
1127 tty_drv->init_termios.c_ispeed = 4800;
1128 tty_drv->init_termios.c_ospeed = 4800;
1129 tty_set_operations(tty_drv, &sdio_uart_ops);
1130
1131 ret = tty_register_driver(tty_drv);
1132 if (ret)
1133 goto err1;
1134
1135 ret = sdio_register_driver(&sdio_uart_driver);
1136 if (ret)
1137 goto err2;
1138
1139 return 0;
1140
1141 err2:
1142 tty_unregister_driver(tty_drv);
1143 err1:
1144 put_tty_driver(tty_drv);
1145 return ret;
1146 }
1147
1148 static void __exit sdio_uart_exit(void)
1149 {
1150 sdio_unregister_driver(&sdio_uart_driver);
1151 tty_unregister_driver(sdio_uart_tty_driver);
1152 put_tty_driver(sdio_uart_tty_driver);
1153 }
1154
1155 module_init(sdio_uart_init);
1156 module_exit(sdio_uart_exit);
1157
1158 MODULE_AUTHOR("Nicolas Pitre");
1159 MODULE_LICENSE("GPL");
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