drivers/mmc/core/sdio

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This source file includes following definitions.
sdio_uart_add_port
sdio_uart_port_get
sdio_uart_port_put
sdio_uart_port_remove
sdio_uart_claim_func
sdio_uart_release_func
sdio_in
sdio_out
sdio_uart_get_mctrl
sdio_uart_write_mctrl
sdio_uart_update_mctrl
sdio_uart_change_speed
sdio_uart_start_tx
sdio_uart_stop_tx
sdio_uart_stop_rx
sdio_uart_receive_chars
sdio_uart_transmit_chars
sdio_uart_check_modem_status
sdio_uart_irq
uart_carrier_raised
uart_dtr_rts
sdio_uart_activate
sdio_uart_shutdown
sdio_uart_port_destroy
sdio_uart_install
sdio_uart_cleanup
sdio_uart_open
sdio_uart_close
sdio_uart_hangup
sdio_uart_write
sdio_uart_write_room
sdio_uart_chars_in_buffer
sdio_uart_send_xchar
sdio_uart_throttle
sdio_uart_unthrottle
sdio_uart_set_termios
sdio_uart_break_ctl
sdio_uart_tiocmget
sdio_uart_tiocmset
sdio_uart_proc_show
sdio_uart_probe
sdio_uart_remove
sdio_uart_init
sdio_uart_exit
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * SDIO UART/GPS driver
   4  *
   5  * Based on drivers/serial/8250.c and drivers/serial/serial_core.c
   6  * by Russell King.
   7  *
   8  * Author:      Nicolas Pitre
   9  * Created:     June 15, 2007
  10  * Copyright:   MontaVista Software, Inc.
  11  */
  12 
  13 /*
  14  * Note: Although this driver assumes a 16550A-like UART implementation,
  15  * it is not possible to leverage the common 8250/16550 driver, nor the
  16  * core UART infrastructure, as they assumes direct access to the hardware
  17  * registers, often under a spinlock.  This is not possible in the SDIO
  18  * context as SDIO access functions must be able to sleep.
  19  *
  20  * Because we need to lock the SDIO host to ensure an exclusive access to
  21  * the card, we simply rely on that lock to also prevent and serialize
  22  * concurrent access to the same port.
  23  */
  24 
  25 #include <linux/module.h>
  26 #include <linux/init.h>
  27 #include <linux/kernel.h>
  28 #include <linux/sched.h>
  29 #include <linux/mutex.h>
  30 #include <linux/seq_file.h>
  31 #include <linux/serial_reg.h>
  32 #include <linux/circ_buf.h>
  33 #include <linux/tty.h>
  34 #include <linux/tty_flip.h>
  35 #include <linux/kfifo.h>
  36 #include <linux/slab.h>
  37 
  38 #include <linux/mmc/core.h>
  39 #include <linux/mmc/card.h>
  40 #include <linux/mmc/sdio_func.h>
  41 #include <linux/mmc/sdio_ids.h>
  42 
  43 
  44 #define UART_NR         8       /* Number of UARTs this driver can handle */
  45 
  46 
  47 #define FIFO_SIZE       PAGE_SIZE
  48 #define WAKEUP_CHARS    256
  49 
  50 struct uart_icount {
  51         __u32   cts;
  52         __u32   dsr;
  53         __u32   rng;
  54         __u32   dcd;
  55         __u32   rx;
  56         __u32   tx;
  57         __u32   frame;
  58         __u32   overrun;
  59         __u32   parity;
  60         __u32   brk;
  61 };
  62 
  63 struct sdio_uart_port {
  64         struct tty_port         port;
  65         unsigned int            index;
  66         struct sdio_func        *func;
  67         struct mutex            func_lock;
  68         struct task_struct      *in_sdio_uart_irq;
  69         unsigned int            regs_offset;
  70         struct kfifo            xmit_fifo;
  71         spinlock_t              write_lock;
  72         struct uart_icount      icount;
  73         unsigned int            uartclk;
  74         unsigned int            mctrl;
  75         unsigned int            rx_mctrl;
  76         unsigned int            read_status_mask;
  77         unsigned int            ignore_status_mask;
  78         unsigned char           x_char;
  79         unsigned char           ier;
  80         unsigned char           lcr;
  81 };
  82 
  83 static struct sdio_uart_port *sdio_uart_table[UART_NR];
  84 static DEFINE_SPINLOCK(sdio_uart_table_lock);
  85 
  86 static int sdio_uart_add_port(struct sdio_uart_port *port)
  87 {
  88         int index, ret = -EBUSY;
  89 
  90         mutex_init(&port->func_lock);
  91         spin_lock_init(&port->write_lock);
  92         if (kfifo_alloc(&port->xmit_fifo, FIFO_SIZE, GFP_KERNEL))
  93                 return -ENOMEM;
  94 
  95         spin_lock(&sdio_uart_table_lock);
  96         for (index = 0; index < UART_NR; index++) {
  97                 if (!sdio_uart_table[index]) {
  98                         port->index = index;
  99                         sdio_uart_table[index] = port;
 100                         ret = 0;
 101                         break;
 102                 }
 103         }
 104         spin_unlock(&sdio_uart_table_lock);
 105 
 106         return ret;
 107 }
 108 
 109 static struct sdio_uart_port *sdio_uart_port_get(unsigned index)
 110 {
 111         struct sdio_uart_port *port;
 112 
 113         if (index >= UART_NR)
 114                 return NULL;
 115 
 116         spin_lock(&sdio_uart_table_lock);
 117         port = sdio_uart_table[index];
 118         if (port)
 119                 tty_port_get(&port->port);
 120         spin_unlock(&sdio_uart_table_lock);
 121 
 122         return port;
 123 }
 124 
 125 static void sdio_uart_port_put(struct sdio_uart_port *port)
 126 {
 127         tty_port_put(&port->port);
 128 }
 129 
 130 static void sdio_uart_port_remove(struct sdio_uart_port *port)
 131 {
 132         struct sdio_func *func;
 133 
 134         spin_lock(&sdio_uart_table_lock);
 135         sdio_uart_table[port->index] = NULL;
 136         spin_unlock(&sdio_uart_table_lock);
 137 
 138         /*
 139          * We're killing a port that potentially still is in use by
 140          * the tty layer. Be careful to prevent any further access
 141          * to the SDIO function and arrange for the tty layer to
 142          * give up on that port ASAP.
 143          * Beware: the lock ordering is critical.
 144          */
 145         mutex_lock(&port->port.mutex);
 146         mutex_lock(&port->func_lock);
 147         func = port->func;
 148         sdio_claim_host(func);
 149         port->func = NULL;
 150         mutex_unlock(&port->func_lock);
 151         /* tty_hangup is async so is this safe as is ?? */
 152         tty_port_tty_hangup(&port->port, false);
 153         mutex_unlock(&port->port.mutex);
 154         sdio_release_irq(func);
 155         sdio_disable_func(func);
 156         sdio_release_host(func);
 157 
 158         sdio_uart_port_put(port);
 159 }
 160 
 161 static int sdio_uart_claim_func(struct sdio_uart_port *port)
 162 {
 163         mutex_lock(&port->func_lock);
 164         if (unlikely(!port->func)) {
 165                 mutex_unlock(&port->func_lock);
 166                 return -ENODEV;
 167         }
 168         if (likely(port->in_sdio_uart_irq != current))
 169                 sdio_claim_host(port->func);
 170         mutex_unlock(&port->func_lock);
 171         return 0;
 172 }
 173 
 174 static inline void sdio_uart_release_func(struct sdio_uart_port *port)
 175 {
 176         if (likely(port->in_sdio_uart_irq != current))
 177                 sdio_release_host(port->func);
 178 }
 179 
 180 static inline unsigned int sdio_in(struct sdio_uart_port *port, int offset)
 181 {
 182         unsigned char c;
 183         c = sdio_readb(port->func, port->regs_offset + offset, NULL);
 184         return c;
 185 }
 186 
 187 static inline void sdio_out(struct sdio_uart_port *port, int offset, int value)
 188 {
 189         sdio_writeb(port->func, value, port->regs_offset + offset, NULL);
 190 }
 191 
 192 static unsigned int sdio_uart_get_mctrl(struct sdio_uart_port *port)
 193 {
 194         unsigned char status;
 195         unsigned int ret;
 196 
 197         /* FIXME: What stops this losing the delta bits and breaking
 198            sdio_uart_check_modem_status ? */
 199         status = sdio_in(port, UART_MSR);
 200 
 201         ret = 0;
 202         if (status & UART_MSR_DCD)
 203                 ret |= TIOCM_CAR;
 204         if (status & UART_MSR_RI)
 205                 ret |= TIOCM_RNG;
 206         if (status & UART_MSR_DSR)
 207                 ret |= TIOCM_DSR;
 208         if (status & UART_MSR_CTS)
 209                 ret |= TIOCM_CTS;
 210         return ret;
 211 }
 212 
 213 static void sdio_uart_write_mctrl(struct sdio_uart_port *port,
 214                                   unsigned int mctrl)
 215 {
 216         unsigned char mcr = 0;
 217 
 218         if (mctrl & TIOCM_RTS)
 219                 mcr |= UART_MCR_RTS;
 220         if (mctrl & TIOCM_DTR)
 221                 mcr |= UART_MCR_DTR;
 222         if (mctrl & TIOCM_OUT1)
 223                 mcr |= UART_MCR_OUT1;
 224         if (mctrl & TIOCM_OUT2)
 225                 mcr |= UART_MCR_OUT2;
 226         if (mctrl & TIOCM_LOOP)
 227                 mcr |= UART_MCR_LOOP;
 228 
 229         sdio_out(port, UART_MCR, mcr);
 230 }
 231 
 232 static inline void sdio_uart_update_mctrl(struct sdio_uart_port *port,
 233                                           unsigned int set, unsigned int clear)
 234 {
 235         unsigned int old;
 236 
 237         old = port->mctrl;
 238         port->mctrl = (old & ~clear) | set;
 239         if (old != port->mctrl)
 240                 sdio_uart_write_mctrl(port, port->mctrl);
 241 }
 242 
 243 #define sdio_uart_set_mctrl(port, x)    sdio_uart_update_mctrl(port, x, 0)
 244 #define sdio_uart_clear_mctrl(port, x)  sdio_uart_update_mctrl(port, 0, x)
 245 
 246 static void sdio_uart_change_speed(struct sdio_uart_port *port,
 247                                    struct ktermios *termios,
 248                                    struct ktermios *old)
 249 {
 250         unsigned char cval, fcr = 0;
 251         unsigned int baud, quot;
 252 
 253         switch (termios->c_cflag & CSIZE) {
 254         case CS5:
 255                 cval = UART_LCR_WLEN5;
 256                 break;
 257         case CS6:
 258                 cval = UART_LCR_WLEN6;
 259                 break;
 260         case CS7:
 261                 cval = UART_LCR_WLEN7;
 262                 break;
 263         default:
 264         case CS8:
 265                 cval = UART_LCR_WLEN8;
 266                 break;
 267         }
 268 
 269         if (termios->c_cflag & CSTOPB)
 270                 cval |= UART_LCR_STOP;
 271         if (termios->c_cflag & PARENB)
 272                 cval |= UART_LCR_PARITY;
 273         if (!(termios->c_cflag & PARODD))
 274                 cval |= UART_LCR_EPAR;
 275 
 276         for (;;) {
 277                 baud = tty_termios_baud_rate(termios);
 278                 if (baud == 0)
 279                         baud = 9600;  /* Special case: B0 rate. */
 280                 if (baud <= port->uartclk)
 281                         break;
 282                 /*
 283                  * Oops, the quotient was zero.  Try again with the old
 284                  * baud rate if possible, otherwise default to 9600.
 285                  */
 286                 termios->c_cflag &= ~CBAUD;
 287                 if (old) {
 288                         termios->c_cflag |= old->c_cflag & CBAUD;
 289                         old = NULL;
 290                 } else
 291                         termios->c_cflag |= B9600;
 292         }
 293         quot = (2 * port->uartclk + baud) / (2 * baud);
 294 
 295         if (baud < 2400)
 296                 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
 297         else
 298                 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10;
 299 
 300         port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
 301         if (termios->c_iflag & INPCK)
 302                 port->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
 303         if (termios->c_iflag & (BRKINT | PARMRK))
 304                 port->read_status_mask |= UART_LSR_BI;
 305 
 306         /*
 307          * Characters to ignore
 308          */
 309         port->ignore_status_mask = 0;
 310         if (termios->c_iflag & IGNPAR)
 311                 port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
 312         if (termios->c_iflag & IGNBRK) {
 313                 port->ignore_status_mask |= UART_LSR_BI;
 314                 /*
 315                  * If we're ignoring parity and break indicators,
 316                  * ignore overruns too (for real raw support).
 317                  */
 318                 if (termios->c_iflag & IGNPAR)
 319                         port->ignore_status_mask |= UART_LSR_OE;
 320         }
 321 
 322         /*
 323          * ignore all characters if CREAD is not set
 324          */
 325         if ((termios->c_cflag & CREAD) == 0)
 326                 port->ignore_status_mask |= UART_LSR_DR;
 327 
 328         /*
 329          * CTS flow control flag and modem status interrupts
 330          */
 331         port->ier &= ~UART_IER_MSI;
 332         if ((termios->c_cflag & CRTSCTS) || !(termios->c_cflag & CLOCAL))
 333                 port->ier |= UART_IER_MSI;
 334 
 335         port->lcr = cval;
 336 
 337         sdio_out(port, UART_IER, port->ier);
 338         sdio_out(port, UART_LCR, cval | UART_LCR_DLAB);
 339         sdio_out(port, UART_DLL, quot & 0xff);
 340         sdio_out(port, UART_DLM, quot >> 8);
 341         sdio_out(port, UART_LCR, cval);
 342         sdio_out(port, UART_FCR, fcr);
 343 
 344         sdio_uart_write_mctrl(port, port->mctrl);
 345 }
 346 
 347 static void sdio_uart_start_tx(struct sdio_uart_port *port)
 348 {
 349         if (!(port->ier & UART_IER_THRI)) {
 350                 port->ier |= UART_IER_THRI;
 351                 sdio_out(port, UART_IER, port->ier);
 352         }
 353 }
 354 
 355 static void sdio_uart_stop_tx(struct sdio_uart_port *port)
 356 {
 357         if (port->ier & UART_IER_THRI) {
 358                 port->ier &= ~UART_IER_THRI;
 359                 sdio_out(port, UART_IER, port->ier);
 360         }
 361 }
 362 
 363 static void sdio_uart_stop_rx(struct sdio_uart_port *port)
 364 {
 365         port->ier &= ~UART_IER_RLSI;
 366         port->read_status_mask &= ~UART_LSR_DR;
 367         sdio_out(port, UART_IER, port->ier);
 368 }
 369 
 370 static void sdio_uart_receive_chars(struct sdio_uart_port *port,
 371                                     unsigned int *status)
 372 {
 373         unsigned int ch, flag;
 374         int max_count = 256;
 375 
 376         do {
 377                 ch = sdio_in(port, UART_RX);
 378                 flag = TTY_NORMAL;
 379                 port->icount.rx++;
 380 
 381                 if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
 382                                         UART_LSR_FE | UART_LSR_OE))) {
 383                         /*
 384                          * For statistics only
 385                          */
 386                         if (*status & UART_LSR_BI) {
 387                                 *status &= ~(UART_LSR_FE | UART_LSR_PE);
 388                                 port->icount.brk++;
 389                         } else if (*status & UART_LSR_PE)
 390                                 port->icount.parity++;
 391                         else if (*status & UART_LSR_FE)
 392                                 port->icount.frame++;
 393                         if (*status & UART_LSR_OE)
 394                                 port->icount.overrun++;
 395 
 396                         /*
 397                          * Mask off conditions which should be ignored.
 398                          */
 399                         *status &= port->read_status_mask;
 400                         if (*status & UART_LSR_BI)
 401                                 flag = TTY_BREAK;
 402                         else if (*status & UART_LSR_PE)
 403                                 flag = TTY_PARITY;
 404                         else if (*status & UART_LSR_FE)
 405                                 flag = TTY_FRAME;
 406                 }
 407 
 408                 if ((*status & port->ignore_status_mask & ~UART_LSR_OE) == 0)
 409                         tty_insert_flip_char(&port->port, ch, flag);
 410 
 411                 /*
 412                  * Overrun is special.  Since it's reported immediately,
 413                  * it doesn't affect the current character.
 414                  */
 415                 if (*status & ~port->ignore_status_mask & UART_LSR_OE)
 416                         tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
 417 
 418                 *status = sdio_in(port, UART_LSR);
 419         } while ((*status & UART_LSR_DR) && (max_count-- > 0));
 420 
 421         tty_flip_buffer_push(&port->port);
 422 }
 423 
 424 static void sdio_uart_transmit_chars(struct sdio_uart_port *port)
 425 {
 426         struct kfifo *xmit = &port->xmit_fifo;
 427         int count;
 428         struct tty_struct *tty;
 429         u8 iobuf[16];
 430         int len;
 431 
 432         if (port->x_char) {
 433                 sdio_out(port, UART_TX, port->x_char);
 434                 port->icount.tx++;
 435                 port->x_char = 0;
 436                 return;
 437         }
 438 
 439         tty = tty_port_tty_get(&port->port);
 440 
 441         if (tty == NULL || !kfifo_len(xmit) ||
 442                                 tty->stopped || tty->hw_stopped) {
 443                 sdio_uart_stop_tx(port);
 444                 tty_kref_put(tty);
 445                 return;
 446         }
 447 
 448         len = kfifo_out_locked(xmit, iobuf, 16, &port->write_lock);
 449         for (count = 0; count < len; count++) {
 450                 sdio_out(port, UART_TX, iobuf[count]);
 451                 port->icount.tx++;
 452         }
 453 
 454         len = kfifo_len(xmit);
 455         if (len < WAKEUP_CHARS) {
 456                 tty_wakeup(tty);
 457                 if (len == 0)
 458                         sdio_uart_stop_tx(port);
 459         }
 460         tty_kref_put(tty);
 461 }
 462 
 463 static void sdio_uart_check_modem_status(struct sdio_uart_port *port)
 464 {
 465         int status;
 466         struct tty_struct *tty;
 467 
 468         status = sdio_in(port, UART_MSR);
 469 
 470         if ((status & UART_MSR_ANY_DELTA) == 0)
 471                 return;
 472 
 473         if (status & UART_MSR_TERI)
 474                 port->icount.rng++;
 475         if (status & UART_MSR_DDSR)
 476                 port->icount.dsr++;
 477         if (status & UART_MSR_DDCD) {
 478                 port->icount.dcd++;
 479                 /* DCD raise - wake for open */
 480                 if (status & UART_MSR_DCD)
 481                         wake_up_interruptible(&port->port.open_wait);
 482                 else {
 483                         /* DCD drop - hang up if tty attached */
 484                         tty_port_tty_hangup(&port->port, false);
 485                 }
 486         }
 487         if (status & UART_MSR_DCTS) {
 488                 port->icount.cts++;
 489                 tty = tty_port_tty_get(&port->port);
 490                 if (tty && C_CRTSCTS(tty)) {
 491                         int cts = (status & UART_MSR_CTS);
 492                         if (tty->hw_stopped) {
 493                                 if (cts) {
 494                                         tty->hw_stopped = 0;
 495                                         sdio_uart_start_tx(port);
 496                                         tty_wakeup(tty);
 497                                 }
 498                         } else {
 499                                 if (!cts) {
 500                                         tty->hw_stopped = 1;
 501                                         sdio_uart_stop_tx(port);
 502                                 }
 503                         }
 504                 }
 505                 tty_kref_put(tty);
 506         }
 507 }
 508 
 509 /*
 510  * This handles the interrupt from one port.
 511  */
 512 static void sdio_uart_irq(struct sdio_func *func)
 513 {
 514         struct sdio_uart_port *port = sdio_get_drvdata(func);
 515         unsigned int iir, lsr;
 516 
 517         /*
 518          * In a few places sdio_uart_irq() is called directly instead of
 519          * waiting for the actual interrupt to be raised and the SDIO IRQ
 520          * thread scheduled in order to reduce latency.  However, some
 521          * interaction with the tty core may end up calling us back
 522          * (serial echo, flow control, etc.) through those same places
 523          * causing undesirable effects.  Let's stop the recursion here.
 524          */
 525         if (unlikely(port->in_sdio_uart_irq == current))
 526                 return;
 527 
 528         iir = sdio_in(port, UART_IIR);
 529         if (iir & UART_IIR_NO_INT)
 530                 return;
 531 
 532         port->in_sdio_uart_irq = current;
 533         lsr = sdio_in(port, UART_LSR);
 534         if (lsr & UART_LSR_DR)
 535                 sdio_uart_receive_chars(port, &lsr);
 536         sdio_uart_check_modem_status(port);
 537         if (lsr & UART_LSR_THRE)
 538                 sdio_uart_transmit_chars(port);
 539         port->in_sdio_uart_irq = NULL;
 540 }
 541 
 542 static int uart_carrier_raised(struct tty_port *tport)
 543 {
 544         struct sdio_uart_port *port =
 545                         container_of(tport, struct sdio_uart_port, port);
 546         unsigned int ret = sdio_uart_claim_func(port);
 547         if (ret)        /* Missing hardware shouldn't block for carrier */
 548                 return 1;
 549         ret = sdio_uart_get_mctrl(port);
 550         sdio_uart_release_func(port);
 551         if (ret & TIOCM_CAR)
 552                 return 1;
 553         return 0;
 554 }
 555 
 556 /**
 557  *      uart_dtr_rts            -        port helper to set uart signals
 558  *      @tport: tty port to be updated
 559  *      @onoff: set to turn on DTR/RTS
 560  *
 561  *      Called by the tty port helpers when the modem signals need to be
 562  *      adjusted during an open, close and hangup.
 563  */
 564 
 565 static void uart_dtr_rts(struct tty_port *tport, int onoff)
 566 {
 567         struct sdio_uart_port *port =
 568                         container_of(tport, struct sdio_uart_port, port);
 569         int ret = sdio_uart_claim_func(port);
 570         if (ret)
 571                 return;
 572         if (onoff == 0)
 573                 sdio_uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
 574         else
 575                 sdio_uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
 576         sdio_uart_release_func(port);
 577 }
 578 
 579 /**
 580  *      sdio_uart_activate      -       start up hardware
 581  *      @tport: tty port to activate
 582  *      @tty: tty bound to this port
 583  *
 584  *      Activate a tty port. The port locking guarantees us this will be
 585  *      run exactly once per set of opens, and if successful will see the
 586  *      shutdown method run exactly once to match. Start up and shutdown are
 587  *      protected from each other by the internal locking and will not run
 588  *      at the same time even during a hangup event.
 589  *
 590  *      If we successfully start up the port we take an extra kref as we
 591  *      will keep it around until shutdown when the kref is dropped.
 592  */
 593 
 594 static int sdio_uart_activate(struct tty_port *tport, struct tty_struct *tty)
 595 {
 596         struct sdio_uart_port *port =
 597                         container_of(tport, struct sdio_uart_port, port);
 598         int ret;
 599 
 600         /*
 601          * Set the TTY IO error marker - we will only clear this
 602          * once we have successfully opened the port.
 603          */
 604         set_bit(TTY_IO_ERROR, &tty->flags);
 605 
 606         kfifo_reset(&port->xmit_fifo);
 607 
 608         ret = sdio_uart_claim_func(port);
 609         if (ret)
 610                 return ret;
 611         ret = sdio_enable_func(port->func);
 612         if (ret)
 613                 goto err1;
 614         ret = sdio_claim_irq(port->func, sdio_uart_irq);
 615         if (ret)
 616                 goto err2;
 617 
 618         /*
 619          * Clear the FIFO buffers and disable them.
 620          * (they will be reenabled in sdio_change_speed())
 621          */
 622         sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO);
 623         sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO |
 624                        UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
 625         sdio_out(port, UART_FCR, 0);
 626 
 627         /*
 628          * Clear the interrupt registers.
 629          */
 630         (void) sdio_in(port, UART_LSR);
 631         (void) sdio_in(port, UART_RX);
 632         (void) sdio_in(port, UART_IIR);
 633         (void) sdio_in(port, UART_MSR);
 634 
 635         /*
 636          * Now, initialize the UART
 637          */
 638         sdio_out(port, UART_LCR, UART_LCR_WLEN8);
 639 
 640         port->ier = UART_IER_RLSI|UART_IER_RDI|UART_IER_RTOIE|UART_IER_UUE;
 641         port->mctrl = TIOCM_OUT2;
 642 
 643         sdio_uart_change_speed(port, &tty->termios, NULL);
 644 
 645         if (C_BAUD(tty))
 646                 sdio_uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
 647 
 648         if (C_CRTSCTS(tty))
 649                 if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS))
 650                         tty->hw_stopped = 1;
 651 
 652         clear_bit(TTY_IO_ERROR, &tty->flags);
 653 
 654         /* Kick the IRQ handler once while we're still holding the host lock */
 655         sdio_uart_irq(port->func);
 656 
 657         sdio_uart_release_func(port);
 658         return 0;
 659 
 660 err2:
 661         sdio_disable_func(port->func);
 662 err1:
 663         sdio_uart_release_func(port);
 664         return ret;
 665 }
 666 
 667 /**
 668  *      sdio_uart_shutdown      -       stop hardware
 669  *      @tport: tty port to shut down
 670  *
 671  *      Deactivate a tty port. The port locking guarantees us this will be
 672  *      run only if a successful matching activate already ran. The two are
 673  *      protected from each other by the internal locking and will not run
 674  *      at the same time even during a hangup event.
 675  */
 676 
 677 static void sdio_uart_shutdown(struct tty_port *tport)
 678 {
 679         struct sdio_uart_port *port =
 680                         container_of(tport, struct sdio_uart_port, port);
 681         int ret;
 682 
 683         ret = sdio_uart_claim_func(port);
 684         if (ret)
 685                 return;
 686 
 687         sdio_uart_stop_rx(port);
 688 
 689         /* Disable interrupts from this port */
 690         sdio_release_irq(port->func);
 691         port->ier = 0;
 692         sdio_out(port, UART_IER, 0);
 693 
 694         sdio_uart_clear_mctrl(port, TIOCM_OUT2);
 695 
 696         /* Disable break condition and FIFOs. */
 697         port->lcr &= ~UART_LCR_SBC;
 698         sdio_out(port, UART_LCR, port->lcr);
 699         sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO |
 700                                  UART_FCR_CLEAR_RCVR |
 701                                  UART_FCR_CLEAR_XMIT);
 702         sdio_out(port, UART_FCR, 0);
 703 
 704         sdio_disable_func(port->func);
 705 
 706         sdio_uart_release_func(port);
 707 }
 708 
 709 static void sdio_uart_port_destroy(struct tty_port *tport)
 710 {
 711         struct sdio_uart_port *port =
 712                 container_of(tport, struct sdio_uart_port, port);
 713         kfifo_free(&port->xmit_fifo);
 714         kfree(port);
 715 }
 716 
 717 /**
 718  *      sdio_uart_install       -       install method
 719  *      @driver: the driver in use (sdio_uart in our case)
 720  *      @tty: the tty being bound
 721  *
 722  *      Look up and bind the tty and the driver together. Initialize
 723  *      any needed private data (in our case the termios)
 724  */
 725 
 726 static int sdio_uart_install(struct tty_driver *driver, struct tty_struct *tty)
 727 {
 728         int idx = tty->index;
 729         struct sdio_uart_port *port = sdio_uart_port_get(idx);
 730         int ret = tty_standard_install(driver, tty);
 731 
 732         if (ret == 0)
 733                 /* This is the ref sdio_uart_port get provided */
 734                 tty->driver_data = port;
 735         else
 736                 sdio_uart_port_put(port);
 737         return ret;
 738 }
 739 
 740 /**
 741  *      sdio_uart_cleanup       -       called on the last tty kref drop
 742  *      @tty: the tty being destroyed
 743  *
 744  *      Called asynchronously when the last reference to the tty is dropped.
 745  *      We cannot destroy the tty->driver_data port kref until this point
 746  */
 747 
 748 static void sdio_uart_cleanup(struct tty_struct *tty)
 749 {
 750         struct sdio_uart_port *port = tty->driver_data;
 751         tty->driver_data = NULL;        /* Bug trap */
 752         sdio_uart_port_put(port);
 753 }
 754 
 755 /*
 756  *      Open/close/hangup is now entirely boilerplate
 757  */
 758 
 759 static int sdio_uart_open(struct tty_struct *tty, struct file *filp)
 760 {
 761         struct sdio_uart_port *port = tty->driver_data;
 762         return tty_port_open(&port->port, tty, filp);
 763 }
 764 
 765 static void sdio_uart_close(struct tty_struct *tty, struct file * filp)
 766 {
 767         struct sdio_uart_port *port = tty->driver_data;
 768         tty_port_close(&port->port, tty, filp);
 769 }
 770 
 771 static void sdio_uart_hangup(struct tty_struct *tty)
 772 {
 773         struct sdio_uart_port *port = tty->driver_data;
 774         tty_port_hangup(&port->port);
 775 }
 776 
 777 static int sdio_uart_write(struct tty_struct *tty, const unsigned char *buf,
 778                            int count)
 779 {
 780         struct sdio_uart_port *port = tty->driver_data;
 781         int ret;
 782 
 783         if (!port->func)
 784                 return -ENODEV;
 785 
 786         ret = kfifo_in_locked(&port->xmit_fifo, buf, count, &port->write_lock);
 787         if (!(port->ier & UART_IER_THRI)) {
 788                 int err = sdio_uart_claim_func(port);
 789                 if (!err) {
 790                         sdio_uart_start_tx(port);
 791                         sdio_uart_irq(port->func);
 792                         sdio_uart_release_func(port);
 793                 } else
 794                         ret = err;
 795         }
 796 
 797         return ret;
 798 }
 799 
 800 static int sdio_uart_write_room(struct tty_struct *tty)
 801 {
 802         struct sdio_uart_port *port = tty->driver_data;
 803         return FIFO_SIZE - kfifo_len(&port->xmit_fifo);
 804 }
 805 
 806 static int sdio_uart_chars_in_buffer(struct tty_struct *tty)
 807 {
 808         struct sdio_uart_port *port = tty->driver_data;
 809         return kfifo_len(&port->xmit_fifo);
 810 }
 811 
 812 static void sdio_uart_send_xchar(struct tty_struct *tty, char ch)
 813 {
 814         struct sdio_uart_port *port = tty->driver_data;
 815 
 816         port->x_char = ch;
 817         if (ch && !(port->ier & UART_IER_THRI)) {
 818                 if (sdio_uart_claim_func(port) != 0)
 819                         return;
 820                 sdio_uart_start_tx(port);
 821                 sdio_uart_irq(port->func);
 822                 sdio_uart_release_func(port);
 823         }
 824 }
 825 
 826 static void sdio_uart_throttle(struct tty_struct *tty)
 827 {
 828         struct sdio_uart_port *port = tty->driver_data;
 829 
 830         if (!I_IXOFF(tty) && !C_CRTSCTS(tty))
 831                 return;
 832 
 833         if (sdio_uart_claim_func(port) != 0)
 834                 return;
 835 
 836         if (I_IXOFF(tty)) {
 837                 port->x_char = STOP_CHAR(tty);
 838                 sdio_uart_start_tx(port);
 839         }
 840 
 841         if (C_CRTSCTS(tty))
 842                 sdio_uart_clear_mctrl(port, TIOCM_RTS);
 843 
 844         sdio_uart_irq(port->func);
 845         sdio_uart_release_func(port);
 846 }
 847 
 848 static void sdio_uart_unthrottle(struct tty_struct *tty)
 849 {
 850         struct sdio_uart_port *port = tty->driver_data;
 851 
 852         if (!I_IXOFF(tty) && !C_CRTSCTS(tty))
 853                 return;
 854 
 855         if (sdio_uart_claim_func(port) != 0)
 856                 return;
 857 
 858         if (I_IXOFF(tty)) {
 859                 if (port->x_char) {
 860                         port->x_char = 0;
 861                 } else {
 862                         port->x_char = START_CHAR(tty);
 863                         sdio_uart_start_tx(port);
 864                 }
 865         }
 866 
 867         if (C_CRTSCTS(tty))
 868                 sdio_uart_set_mctrl(port, TIOCM_RTS);
 869 
 870         sdio_uart_irq(port->func);
 871         sdio_uart_release_func(port);
 872 }
 873 
 874 static void sdio_uart_set_termios(struct tty_struct *tty,
 875                                                 struct ktermios *old_termios)
 876 {
 877         struct sdio_uart_port *port = tty->driver_data;
 878         unsigned int cflag = tty->termios.c_cflag;
 879 
 880         if (sdio_uart_claim_func(port) != 0)
 881                 return;
 882 
 883         sdio_uart_change_speed(port, &tty->termios, old_termios);
 884 
 885         /* Handle transition to B0 status */
 886         if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
 887                 sdio_uart_clear_mctrl(port, TIOCM_RTS | TIOCM_DTR);
 888 
 889         /* Handle transition away from B0 status */
 890         if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
 891                 unsigned int mask = TIOCM_DTR;
 892                 if (!(cflag & CRTSCTS) || !tty_throttled(tty))
 893                         mask |= TIOCM_RTS;
 894                 sdio_uart_set_mctrl(port, mask);
 895         }
 896 
 897         /* Handle turning off CRTSCTS */
 898         if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
 899                 tty->hw_stopped = 0;
 900                 sdio_uart_start_tx(port);
 901         }
 902 
 903         /* Handle turning on CRTSCTS */
 904         if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
 905                 if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS)) {
 906                         tty->hw_stopped = 1;
 907                         sdio_uart_stop_tx(port);
 908                 }
 909         }
 910 
 911         sdio_uart_release_func(port);
 912 }
 913 
 914 static int sdio_uart_break_ctl(struct tty_struct *tty, int break_state)
 915 {
 916         struct sdio_uart_port *port = tty->driver_data;
 917         int result;
 918 
 919         result = sdio_uart_claim_func(port);
 920         if (result != 0)
 921                 return result;
 922 
 923         if (break_state == -1)
 924                 port->lcr |= UART_LCR_SBC;
 925         else
 926                 port->lcr &= ~UART_LCR_SBC;
 927         sdio_out(port, UART_LCR, port->lcr);
 928 
 929         sdio_uart_release_func(port);
 930         return 0;
 931 }
 932 
 933 static int sdio_uart_tiocmget(struct tty_struct *tty)
 934 {
 935         struct sdio_uart_port *port = tty->driver_data;
 936         int result;
 937 
 938         result = sdio_uart_claim_func(port);
 939         if (!result) {
 940                 result = port->mctrl | sdio_uart_get_mctrl(port);
 941                 sdio_uart_release_func(port);
 942         }
 943 
 944         return result;
 945 }
 946 
 947 static int sdio_uart_tiocmset(struct tty_struct *tty,
 948                               unsigned int set, unsigned int clear)
 949 {
 950         struct sdio_uart_port *port = tty->driver_data;
 951         int result;
 952 
 953         result = sdio_uart_claim_func(port);
 954         if (!result) {
 955                 sdio_uart_update_mctrl(port, set, clear);
 956                 sdio_uart_release_func(port);
 957         }
 958 
 959         return result;
 960 }
 961 
 962 static int sdio_uart_proc_show(struct seq_file *m, void *v)
 963 {
 964         int i;
 965 
 966         seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
 967                        "", "", "");
 968         for (i = 0; i < UART_NR; i++) {
 969                 struct sdio_uart_port *port = sdio_uart_port_get(i);
 970                 if (port) {
 971                         seq_printf(m, "%d: uart:SDIO", i);
 972                         if (capable(CAP_SYS_ADMIN)) {
 973                                 seq_printf(m, " tx:%d rx:%d",
 974                                               port->icount.tx, port->icount.rx);
 975                                 if (port->icount.frame)
 976                                         seq_printf(m, " fe:%d",
 977                                                       port->icount.frame);
 978                                 if (port->icount.parity)
 979                                         seq_printf(m, " pe:%d",
 980                                                       port->icount.parity);
 981                                 if (port->icount.brk)
 982                                         seq_printf(m, " brk:%d",
 983                                                       port->icount.brk);
 984                                 if (port->icount.overrun)
 985                                         seq_printf(m, " oe:%d",
 986                                                       port->icount.overrun);
 987                                 if (port->icount.cts)
 988                                         seq_printf(m, " cts:%d",
 989                                                       port->icount.cts);
 990                                 if (port->icount.dsr)
 991                                         seq_printf(m, " dsr:%d",
 992                                                       port->icount.dsr);
 993                                 if (port->icount.rng)
 994                                         seq_printf(m, " rng:%d",
 995                                                       port->icount.rng);
 996                                 if (port->icount.dcd)
 997                                         seq_printf(m, " dcd:%d",
 998                                                       port->icount.dcd);
 999                         }
1000                         sdio_uart_port_put(port);
1001                         seq_putc(m, '\n');
1002                 }
1003         }
1004         return 0;
1005 }
1006 
1007 static const struct tty_port_operations sdio_uart_port_ops = {
1008         .dtr_rts = uart_dtr_rts,
1009         .carrier_raised = uart_carrier_raised,
1010         .shutdown = sdio_uart_shutdown,
1011         .activate = sdio_uart_activate,
1012         .destruct = sdio_uart_port_destroy,
1013 };
1014 
1015 static const struct tty_operations sdio_uart_ops = {
1016         .open                   = sdio_uart_open,
1017         .close                  = sdio_uart_close,
1018         .write                  = sdio_uart_write,
1019         .write_room             = sdio_uart_write_room,
1020         .chars_in_buffer        = sdio_uart_chars_in_buffer,
1021         .send_xchar             = sdio_uart_send_xchar,
1022         .throttle               = sdio_uart_throttle,
1023         .unthrottle             = sdio_uart_unthrottle,
1024         .set_termios            = sdio_uart_set_termios,
1025         .hangup                 = sdio_uart_hangup,
1026         .break_ctl              = sdio_uart_break_ctl,
1027         .tiocmget               = sdio_uart_tiocmget,
1028         .tiocmset               = sdio_uart_tiocmset,
1029         .install                = sdio_uart_install,
1030         .cleanup                = sdio_uart_cleanup,
1031         .proc_show              = sdio_uart_proc_show,
1032 };
1033 
1034 static struct tty_driver *sdio_uart_tty_driver;
1035 
1036 static int sdio_uart_probe(struct sdio_func *func,
1037                            const struct sdio_device_id *id)
1038 {
1039         struct sdio_uart_port *port;
1040         int ret;
1041 
1042         port = kzalloc(sizeof(struct sdio_uart_port), GFP_KERNEL);
1043         if (!port)
1044                 return -ENOMEM;
1045 
1046         if (func->class == SDIO_CLASS_UART) {
1047                 pr_warn("%s: need info on UART class basic setup\n",
1048                         sdio_func_id(func));
1049                 kfree(port);
1050                 return -ENOSYS;
1051         } else if (func->class == SDIO_CLASS_GPS) {
1052                 /*
1053                  * We need tuple 0x91.  It contains SUBTPL_SIOREG
1054                  * and SUBTPL_RCVCAPS.
1055                  */
1056                 struct sdio_func_tuple *tpl;
1057                 for (tpl = func->tuples; tpl; tpl = tpl->next) {
1058                         if (tpl->code != 0x91)
1059                                 continue;
1060                         if (tpl->size < 10)
1061                                 continue;
1062                         if (tpl->data[1] == 0)  /* SUBTPL_SIOREG */
1063                                 break;
1064                 }
1065                 if (!tpl) {
1066                         pr_warn("%s: can't find tuple 0x91 subtuple 0 (SUBTPL_SIOREG) for GPS class\n",
1067                                 sdio_func_id(func));
1068                         kfree(port);
1069                         return -EINVAL;
1070                 }
1071                 pr_debug("%s: Register ID = 0x%02x, Exp ID = 0x%02x\n",
1072                        sdio_func_id(func), tpl->data[2], tpl->data[3]);
1073                 port->regs_offset = (tpl->data[4] << 0) |
1074                                     (tpl->data[5] << 8) |
1075                                     (tpl->data[6] << 16);
1076                 pr_debug("%s: regs offset = 0x%x\n",
1077                        sdio_func_id(func), port->regs_offset);
1078                 port->uartclk = tpl->data[7] * 115200;
1079                 if (port->uartclk == 0)
1080                         port->uartclk = 115200;
1081                 pr_debug("%s: clk %d baudcode %u 4800-div %u\n",
1082                        sdio_func_id(func), port->uartclk,
1083                        tpl->data[7], tpl->data[8] | (tpl->data[9] << 8));
1084         } else {
1085                 kfree(port);
1086                 return -EINVAL;
1087         }
1088 
1089         port->func = func;
1090         sdio_set_drvdata(func, port);
1091         tty_port_init(&port->port);
1092         port->port.ops = &sdio_uart_port_ops;
1093 
1094         ret = sdio_uart_add_port(port);
1095         if (ret) {
1096                 kfree(port);
1097         } else {
1098                 struct device *dev;
1099                 dev = tty_port_register_device(&port->port,
1100                                 sdio_uart_tty_driver, port->index, &func->dev);
1101                 if (IS_ERR(dev)) {
1102                         sdio_uart_port_remove(port);
1103                         ret = PTR_ERR(dev);
1104                 }
1105         }
1106 
1107         return ret;
1108 }
1109 
1110 static void sdio_uart_remove(struct sdio_func *func)
1111 {
1112         struct sdio_uart_port *port = sdio_get_drvdata(func);
1113 
1114         tty_unregister_device(sdio_uart_tty_driver, port->index);
1115         sdio_uart_port_remove(port);
1116 }
1117 
1118 static const struct sdio_device_id sdio_uart_ids[] = {
1119         { SDIO_DEVICE_CLASS(SDIO_CLASS_UART)            },
1120         { SDIO_DEVICE_CLASS(SDIO_CLASS_GPS)             },
1121         { /* end: all zeroes */                         },
1122 };
1123 
1124 MODULE_DEVICE_TABLE(sdio, sdio_uart_ids);
1125 
1126 static struct sdio_driver sdio_uart_driver = {
1127         .probe          = sdio_uart_probe,
1128         .remove         = sdio_uart_remove,
1129         .name           = "sdio_uart",
1130         .id_table       = sdio_uart_ids,
1131 };
1132 
1133 static int __init sdio_uart_init(void)
1134 {
1135         int ret;
1136         struct tty_driver *tty_drv;
1137 
1138         sdio_uart_tty_driver = tty_drv = alloc_tty_driver(UART_NR);
1139         if (!tty_drv)
1140                 return -ENOMEM;
1141 
1142         tty_drv->driver_name = "sdio_uart";
1143         tty_drv->name =   "ttySDIO";
1144         tty_drv->major = 0;  /* dynamically allocated */
1145         tty_drv->minor_start = 0;
1146         tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
1147         tty_drv->subtype = SERIAL_TYPE_NORMAL;
1148         tty_drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1149         tty_drv->init_termios = tty_std_termios;
1150         tty_drv->init_termios.c_cflag = B4800 | CS8 | CREAD | HUPCL | CLOCAL;
1151         tty_drv->init_termios.c_ispeed = 4800;
1152         tty_drv->init_termios.c_ospeed = 4800;
1153         tty_set_operations(tty_drv, &sdio_uart_ops);
1154 
1155         ret = tty_register_driver(tty_drv);
1156         if (ret)
1157                 goto err1;
1158 
1159         ret = sdio_register_driver(&sdio_uart_driver);
1160         if (ret)
1161                 goto err2;
1162 
1163         return 0;
1164 
1165 err2:
1166         tty_unregister_driver(tty_drv);
1167 err1:
1168         put_tty_driver(tty_drv);
1169         return ret;
1170 }
1171 
1172 static void __exit sdio_uart_exit(void)
1173 {
1174         sdio_unregister_driver(&sdio_uart_driver);
1175         tty_unregister_driver(sdio_uart_tty_driver);
1176         put_tty_driver(sdio_uart_tty_driver);
1177 }
1178 
1179 module_init(sdio_uart_init);
1180 module_exit(sdio_uart_exit);
1181 
1182 MODULE_AUTHOR("Nicolas Pitre");
1183 MODULE_LICENSE("GPL");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/mmc/core/sdio_uart.c

DEFINITIONS
