Version:  2.0.40 2.2.26 2.4.37 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15

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

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us