The Design and Implementation of the FreeBSD Operating System, Second Edition
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sys/mips/cavium/uart_dev_oct16550.c

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    1 /*-
    2  * Copyright (c) 2003 Marcel Moolenaar
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  *
    9  * 1. Redistributions of source code must retain the above copyright
   10  *    notice, this list of conditions and the following disclaimer.
   11  * 2. Redistributions in binary form must reproduce the above copyright
   12  *    notice, this list of conditions and the following disclaimer in the
   13  *    documentation and/or other materials provided with the distribution.
   14  *
   15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   25  */
   26 
   27 /*
   28  * uart_dev_oct16550.c
   29  *
   30  * Derived from uart_dev_ns8250.c
   31  *
   32  * Redistribution and use in source and binary forms, with or without
   33  * modification, are permitted provided that the following conditions
   34  * are met:
   35  *
   36  * 1. Redistributions of source code must retain the above copyright
   37  *    notice, this list of conditions and the following disclaimer.
   38  * 2. Redistributions in binary form must reproduce the above copyright
   39  *    notice, this list of conditions and the following disclaimer in the
   40  *    documentation and/or other materials provided with the distribution.
   41  *
   42  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   43  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   44  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   45  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   46  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   47  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   48  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   49  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   50  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   51  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   52  *
   53  *
   54  */
   55 
   56 
   57 #include <sys/cdefs.h>
   58 __FBSDID("$FreeBSD: releng/8.2/sys/mips/cavium/uart_dev_oct16550.c 215938 2010-11-27 12:26:40Z jchandra $");
   59 
   60 #include <sys/param.h>
   61 #include <sys/systm.h>
   62 #include <sys/bus.h>
   63 #include <sys/conf.h>
   64 #include <machine/bus.h>
   65 #include <machine/pcpu.h>
   66 
   67 #include <dev/uart/uart.h>
   68 #include <dev/uart/uart_cpu.h>
   69 #include <dev/uart/uart_bus.h>
   70 
   71 #include <dev/ic/ns16550.h>
   72 
   73 #include <mips/cavium/octeon_pcmap_regs.h>
   74 
   75 #include <contrib/octeon-sdk/cvmx.h>
   76 #include <contrib/octeon-sdk/cvmx-interrupt.h>
   77 
   78 #include "uart_if.h"
   79 
   80 /*
   81  * Clear pending interrupts. THRE is cleared by reading IIR. Data
   82  * that may have been received gets lost here.
   83  */
   84 static void
   85 oct16550_clrint (struct uart_bas *bas)
   86 {
   87         uint8_t iir;
   88 
   89         iir = uart_getreg(bas, REG_IIR);
   90         while ((iir & IIR_NOPEND) == 0) {
   91                 iir &= IIR_IMASK;
   92                 if (iir == IIR_RLS)
   93                         (void)uart_getreg(bas, REG_LSR);
   94                 else if (iir == IIR_RXRDY || iir == IIR_RXTOUT)
   95                         (void)uart_getreg(bas, REG_DATA);
   96                 else if (iir == IIR_MLSC)
   97                         (void)uart_getreg(bas, REG_MSR);
   98                 else if (iir == IIR_BUSY)
   99                         (void) uart_getreg(bas, REG_USR);
  100                 uart_barrier(bas);
  101                 iir = uart_getreg(bas, REG_IIR);
  102         }
  103 }
  104 
  105 static int delay_changed = 1;
  106 
  107 static int
  108 oct16550_delay (struct uart_bas *bas)
  109 {
  110         int divisor;
  111         u_char lcr;
  112         static int delay = 0;
  113 
  114         if (!delay_changed) return delay;
  115         delay_changed = 0;
  116         lcr = uart_getreg(bas, REG_LCR);
  117         uart_setreg(bas, REG_LCR, lcr | LCR_DLAB);
  118         uart_barrier(bas);
  119         divisor = uart_getreg(bas, REG_DLL) | (uart_getreg(bas, REG_DLH) << 8);
  120         uart_barrier(bas);
  121         uart_setreg(bas, REG_LCR, lcr);
  122         uart_barrier(bas);
  123         
  124         if(!bas->rclk)
  125                 return 10; /* return an approx delay value */
  126 
  127         /* 1/10th the time to transmit 1 character (estimate). */
  128         if (divisor <= 134)
  129                 return (16000000 * divisor / bas->rclk);
  130         return (16000 * divisor / (bas->rclk / 1000));
  131 
  132 }
  133 
  134 static int
  135 oct16550_divisor (int rclk, int baudrate)
  136 {
  137         int actual_baud, divisor;
  138         int error;
  139 
  140         if (baudrate == 0)
  141                 return (0);
  142 
  143         divisor = (rclk / (baudrate << 3) + 1) >> 1;
  144         if (divisor == 0 || divisor >= 65536)
  145                 return (0);
  146         actual_baud = rclk / (divisor << 4);
  147 
  148         /* 10 times error in percent: */
  149         error = ((actual_baud - baudrate) * 2000 / baudrate + 1) >> 1;
  150 
  151         /* 3.0% maximum error tolerance: */
  152         if (error < -30 || error > 30)
  153                 return (0);
  154 
  155         return (divisor);
  156 }
  157 
  158 static int
  159 oct16550_drain (struct uart_bas *bas, int what)
  160 {
  161         int delay, limit;
  162 
  163         delay = oct16550_delay(bas);
  164 
  165         if (what & UART_DRAIN_TRANSMITTER) {
  166                 /*
  167                  * Pick an arbitrary high limit to avoid getting stuck in
  168                  * an infinite loop when the hardware is broken. Make the
  169                  * limit high enough to handle large FIFOs.
  170                  */
  171                 limit = 10*10*10*1024;
  172                 while ((uart_getreg(bas, REG_LSR) & LSR_TEMT) == 0 && --limit)
  173                         DELAY(delay);
  174                 if (limit == 0) {
  175                         /* printf("oct16550: transmitter appears stuck... "); */
  176                         return (0);
  177                 }
  178         }
  179 
  180         if (what & UART_DRAIN_RECEIVER) {
  181                 /*
  182                  * Pick an arbitrary high limit to avoid getting stuck in
  183                  * an infinite loop when the hardware is broken. Make the
  184                  * limit high enough to handle large FIFOs and integrated
  185                  * UARTs. The HP rx2600 for example has 3 UARTs on the
  186                  * management board that tend to get a lot of data send
  187                  * to it when the UART is first activated.
  188                  */
  189                 limit=10*4096;
  190                 while ((uart_getreg(bas, REG_LSR) & LSR_RXRDY) && --limit) {
  191                         (void)uart_getreg(bas, REG_DATA);
  192                         uart_barrier(bas);
  193                         DELAY(delay << 2);
  194                 }
  195                 if (limit == 0) {
  196                         /* printf("oct16550: receiver appears broken... "); */
  197                         return (EIO);
  198                 }
  199         }
  200 
  201         return (0);
  202 }
  203 
  204 /*
  205  * We can only flush UARTs with FIFOs. UARTs without FIFOs should be
  206  * drained. WARNING: this function clobbers the FIFO setting!
  207  */
  208 static void
  209 oct16550_flush (struct uart_bas *bas, int what)
  210 {
  211         uint8_t fcr;
  212 
  213         fcr = FCR_ENABLE;
  214         if (what & UART_FLUSH_TRANSMITTER)
  215                 fcr |= FCR_XMT_RST;
  216         if (what & UART_FLUSH_RECEIVER)
  217                 fcr |= FCR_RCV_RST;
  218         uart_setreg(bas, REG_FCR, fcr);
  219         uart_barrier(bas);
  220 }
  221 
  222 static int
  223 oct16550_param (struct uart_bas *bas, int baudrate, int databits, int stopbits,
  224     int parity)
  225 {
  226         int divisor;
  227         uint8_t lcr;
  228 
  229         lcr = 0;
  230         if (databits >= 8)
  231                 lcr |= LCR_8BITS;
  232         else if (databits == 7)
  233                 lcr |= LCR_7BITS;
  234         else if (databits == 6)
  235                 lcr |= LCR_6BITS;
  236         else
  237                 lcr |= LCR_5BITS;
  238         if (stopbits > 1)
  239                 lcr |= LCR_STOPB;
  240         lcr |= parity << 3;
  241 
  242         /* Set baudrate. */
  243         if (baudrate > 0) {
  244                 divisor = oct16550_divisor(bas->rclk, baudrate);
  245                 if (divisor == 0)
  246                         return (EINVAL);
  247                 uart_setreg(bas, REG_LCR, lcr | LCR_DLAB);
  248                 uart_barrier(bas);
  249                 uart_setreg(bas, REG_DLL, divisor & 0xff);
  250                 uart_setreg(bas, REG_DLH, (divisor >> 8) & 0xff);
  251                 uart_barrier(bas);
  252                 delay_changed = 1;
  253         }
  254 
  255         /* Set LCR and clear DLAB. */
  256         uart_setreg(bas, REG_LCR, lcr);
  257         uart_barrier(bas);
  258         return (0);
  259 }
  260 
  261 /*
  262  * Low-level UART interface.
  263  */
  264 static int oct16550_probe(struct uart_bas *bas);
  265 static void oct16550_init(struct uart_bas *bas, int, int, int, int);
  266 static void oct16550_term(struct uart_bas *bas);
  267 static void oct16550_putc(struct uart_bas *bas, int);
  268 static int oct16550_rxready(struct uart_bas *bas);
  269 static int oct16550_getc(struct uart_bas *bas, struct mtx *);
  270 
  271 struct uart_ops uart_oct16550_ops = {
  272         .probe = oct16550_probe,
  273         .init = oct16550_init,
  274         .term = oct16550_term,
  275         .putc = oct16550_putc,
  276         .rxready = oct16550_rxready,
  277         .getc = oct16550_getc,
  278 };
  279 
  280 static int
  281 oct16550_probe (struct uart_bas *bas)
  282 {
  283         u_char val;
  284 
  285         /* Check known 0 bits that don't depend on DLAB. */
  286         val = uart_getreg(bas, REG_IIR);
  287         if (val & 0x30)
  288                 return (ENXIO);
  289         val = uart_getreg(bas, REG_MCR);
  290         if (val & 0xc0)
  291                 return (ENXIO);
  292         val = uart_getreg(bas, REG_USR);
  293         if (val & 0xe0)
  294                 return (ENXIO);
  295         return (0);
  296 }
  297 
  298 static void
  299 oct16550_init (struct uart_bas *bas, int baudrate, int databits, int stopbits,
  300     int parity)
  301 {
  302         u_char  ier;
  303 
  304         oct16550_param(bas, baudrate, databits, stopbits, parity);
  305 
  306         /* Disable all interrupt sources. */
  307         ier = uart_getreg(bas, REG_IER) & 0x0;
  308         uart_setreg(bas, REG_IER, ier);
  309         uart_barrier(bas);
  310 
  311         /* Disable the FIFO (if present). */
  312 //      uart_setreg(bas, REG_FCR, 0);
  313         uart_barrier(bas);
  314 
  315         /* Set RTS & DTR. */
  316         uart_setreg(bas, REG_MCR, MCR_RTS | MCR_DTR);
  317         uart_barrier(bas);
  318 
  319         oct16550_clrint(bas);
  320 }
  321 
  322 static void
  323 oct16550_term (struct uart_bas *bas)
  324 {
  325 
  326         /* Clear RTS & DTR. */
  327         uart_setreg(bas, REG_MCR, 0);
  328         uart_barrier(bas);
  329 }
  330 
  331 static inline void oct16550_wait_txhr_empty (struct uart_bas *bas, int limit, int delay)
  332 {
  333     while (((uart_getreg(bas, REG_LSR) & LSR_THRE) == 0) &&
  334            ((uart_getreg(bas, REG_USR) & USR_TXFIFO_NOTFULL) == 0))
  335         DELAY(delay);
  336 }
  337 
  338 static void
  339 oct16550_putc (struct uart_bas *bas, int c)
  340 {
  341         int delay;
  342 
  343         /* 1/10th the time to transmit 1 character (estimate). */
  344         delay = oct16550_delay(bas);
  345         oct16550_wait_txhr_empty(bas, 100, delay);
  346         uart_setreg(bas, REG_DATA, c);
  347         uart_barrier(bas);
  348         oct16550_wait_txhr_empty(bas, 100, delay);
  349 }
  350 
  351 static int
  352 oct16550_rxready (struct uart_bas *bas)
  353 {
  354 
  355         return ((uart_getreg(bas, REG_LSR) & LSR_RXRDY) != 0 ? 1 : 0);
  356 }
  357 
  358 static int
  359 oct16550_getc (struct uart_bas *bas, struct mtx *hwmtx)
  360 {
  361         int c, delay;
  362 
  363         uart_lock(hwmtx);
  364 
  365         /* 1/10th the time to transmit 1 character (estimate). */
  366         delay = oct16550_delay(bas);
  367 
  368         while ((uart_getreg(bas, REG_LSR) & LSR_RXRDY) == 0) {
  369                 uart_unlock(hwmtx);
  370                 DELAY(delay);
  371                 uart_lock(hwmtx);
  372         }
  373 
  374         c = uart_getreg(bas, REG_DATA);
  375 
  376         uart_unlock(hwmtx);
  377 
  378         return (c);
  379 }
  380 
  381 /*
  382  * High-level UART interface.
  383  */
  384 struct oct16550_softc {
  385         struct uart_softc base;
  386         uint8_t         fcr;
  387         uint8_t         ier;
  388         uint8_t         mcr;
  389 };
  390 
  391 static int oct16550_bus_attach(struct uart_softc *);
  392 static int oct16550_bus_detach(struct uart_softc *);
  393 static int oct16550_bus_flush(struct uart_softc *, int);
  394 static int oct16550_bus_getsig(struct uart_softc *);
  395 static int oct16550_bus_ioctl(struct uart_softc *, int, intptr_t);
  396 static int oct16550_bus_ipend(struct uart_softc *);
  397 static int oct16550_bus_param(struct uart_softc *, int, int, int, int);
  398 static int oct16550_bus_probe(struct uart_softc *);
  399 static int oct16550_bus_receive(struct uart_softc *);
  400 static int oct16550_bus_setsig(struct uart_softc *, int);
  401 static int oct16550_bus_transmit(struct uart_softc *);
  402 
  403 static kobj_method_t oct16550_methods[] = {
  404         KOBJMETHOD(uart_attach,         oct16550_bus_attach),
  405         KOBJMETHOD(uart_detach,         oct16550_bus_detach),
  406         KOBJMETHOD(uart_flush,          oct16550_bus_flush),
  407         KOBJMETHOD(uart_getsig,         oct16550_bus_getsig),
  408         KOBJMETHOD(uart_ioctl,          oct16550_bus_ioctl),
  409         KOBJMETHOD(uart_ipend,          oct16550_bus_ipend),
  410         KOBJMETHOD(uart_param,          oct16550_bus_param),
  411         KOBJMETHOD(uart_probe,          oct16550_bus_probe),
  412         KOBJMETHOD(uart_receive,        oct16550_bus_receive),
  413         KOBJMETHOD(uart_setsig,         oct16550_bus_setsig),
  414         KOBJMETHOD(uart_transmit,       oct16550_bus_transmit),
  415         { 0, 0 }
  416 };
  417 
  418 struct uart_class uart_oct16550_class = {
  419         "oct16550 class",
  420         oct16550_methods,
  421         sizeof(struct oct16550_softc),
  422         .uc_ops = &uart_oct16550_ops,
  423         .uc_range = 8 << 3,
  424         .uc_rclk = 0
  425 };
  426 
  427 #define SIGCHG(c, i, s, d)                              \
  428         if (c) {                                        \
  429                 i |= (i & s) ? s : s | d;               \
  430         } else {                                        \
  431                 i = (i & s) ? (i & ~s) | d : i;         \
  432         }
  433 
  434 static int
  435 oct16550_bus_attach (struct uart_softc *sc)
  436 {
  437         struct oct16550_softc *oct16550 = (struct oct16550_softc*)sc;
  438         struct uart_bas *bas;
  439         int unit;
  440 
  441         unit = device_get_unit(sc->sc_dev);
  442         bas = &sc->sc_bas;
  443 
  444         oct16550_drain(bas, UART_DRAIN_TRANSMITTER);
  445         oct16550->mcr = uart_getreg(bas, REG_MCR);
  446         oct16550->fcr = FCR_ENABLE | FCR_RX_HIGH;
  447         uart_setreg(bas, REG_FCR, oct16550->fcr);
  448         uart_barrier(bas);
  449         oct16550_bus_flush(sc, UART_FLUSH_RECEIVER|UART_FLUSH_TRANSMITTER);
  450 
  451         if (oct16550->mcr & MCR_DTR)
  452                 sc->sc_hwsig |= SER_DTR;
  453         if (oct16550->mcr & MCR_RTS)
  454                 sc->sc_hwsig |= SER_RTS;
  455         oct16550_bus_getsig(sc);
  456 
  457         oct16550_clrint(bas);
  458         oct16550->ier = uart_getreg(bas, REG_IER) & 0xf0;
  459         oct16550->ier |= IER_EMSC | IER_ERLS | IER_ERXRDY;
  460         uart_setreg(bas, REG_IER, oct16550->ier);
  461         uart_barrier(bas);
  462 
  463         /*
  464          * Enable the interrupt in CIU.     // UART-x2 @ IP2
  465          */
  466         switch (unit) {
  467         case 0:
  468                 cvmx_interrupt_unmask_irq(CVMX_IRQ_UART0);
  469                 break;
  470         case 1:
  471                 cvmx_interrupt_unmask_irq(CVMX_IRQ_UART1);
  472                 break;
  473         default:
  474                 panic("%s: invalid UART %d", __func__, unit);
  475         }
  476         return (0);
  477 }
  478 
  479 static int
  480 oct16550_bus_detach (struct uart_softc *sc)
  481 {
  482         struct uart_bas *bas;
  483         u_char ier;
  484 
  485         bas = &sc->sc_bas;
  486         ier = uart_getreg(bas, REG_IER) & 0xf0;
  487         uart_setreg(bas, REG_IER, ier);
  488         uart_barrier(bas);
  489         oct16550_clrint(bas);
  490         return (0);
  491 }
  492 
  493 static int
  494 oct16550_bus_flush (struct uart_softc *sc, int what)
  495 {
  496         struct oct16550_softc *oct16550 = (struct oct16550_softc*)sc;
  497         struct uart_bas *bas;
  498         int error;
  499 
  500         bas = &sc->sc_bas;
  501         uart_lock(sc->sc_hwmtx);
  502         if (sc->sc_rxfifosz > 1) {
  503                 oct16550_flush(bas, what);
  504                 uart_setreg(bas, REG_FCR, oct16550->fcr);
  505                 uart_barrier(bas);
  506                 error = 0;
  507         } else
  508                 error = oct16550_drain(bas, what);
  509         uart_unlock(sc->sc_hwmtx);
  510         return (error);
  511 }
  512 
  513 static int
  514 oct16550_bus_getsig (struct uart_softc *sc)
  515 {
  516         uint32_t new, old, sig;
  517         uint8_t msr;
  518 
  519         do {
  520                 old = sc->sc_hwsig;
  521                 sig = old;
  522                 uart_lock(sc->sc_hwmtx);
  523                 msr = uart_getreg(&sc->sc_bas, REG_MSR);
  524                 uart_unlock(sc->sc_hwmtx);
  525                 SIGCHG(msr & MSR_DSR, sig, SER_DSR, SER_DDSR);
  526                 SIGCHG(msr & MSR_CTS, sig, SER_CTS, SER_DCTS);
  527                 SIGCHG(msr & MSR_DCD, sig, SER_DCD, SER_DDCD);
  528                 SIGCHG(msr & MSR_RI,  sig, SER_RI,  SER_DRI);
  529                 new = sig & ~SER_MASK_DELTA;
  530         } while (!atomic_cmpset_32(&sc->sc_hwsig, old, new));
  531         return (sig);
  532 }
  533 
  534 static int
  535 oct16550_bus_ioctl (struct uart_softc *sc, int request, intptr_t data)
  536 {
  537         struct uart_bas *bas;
  538         int baudrate, divisor, error;
  539         uint8_t efr, lcr;
  540 
  541         bas = &sc->sc_bas;
  542         error = 0;
  543         uart_lock(sc->sc_hwmtx);
  544         switch (request) {
  545         case UART_IOCTL_BREAK:
  546                 lcr = uart_getreg(bas, REG_LCR);
  547                 if (data)
  548                         lcr |= LCR_SBREAK;
  549                 else
  550                         lcr &= ~LCR_SBREAK;
  551                 uart_setreg(bas, REG_LCR, lcr);
  552                 uart_barrier(bas);
  553                 break;
  554         case UART_IOCTL_IFLOW:
  555                 lcr = uart_getreg(bas, REG_LCR);
  556                 uart_barrier(bas);
  557                 uart_setreg(bas, REG_LCR, 0xbf);
  558                 uart_barrier(bas);
  559                 efr = uart_getreg(bas, REG_EFR);
  560                 if (data)
  561                         efr |= EFR_RTS;
  562                 else
  563                         efr &= ~EFR_RTS;
  564                 uart_setreg(bas, REG_EFR, efr);
  565                 uart_barrier(bas);
  566                 uart_setreg(bas, REG_LCR, lcr);
  567                 uart_barrier(bas);
  568                 break;
  569         case UART_IOCTL_OFLOW:
  570                 lcr = uart_getreg(bas, REG_LCR);
  571                 uart_barrier(bas);
  572                 uart_setreg(bas, REG_LCR, 0xbf);
  573                 uart_barrier(bas);
  574                 efr = uart_getreg(bas, REG_EFR);
  575                 if (data)
  576                         efr |= EFR_CTS;
  577                 else
  578                         efr &= ~EFR_CTS;
  579                 uart_setreg(bas, REG_EFR, efr);
  580                 uart_barrier(bas);
  581                 uart_setreg(bas, REG_LCR, lcr);
  582                 uart_barrier(bas);
  583                 break;
  584         case UART_IOCTL_BAUD:
  585                 lcr = uart_getreg(bas, REG_LCR);
  586                 uart_setreg(bas, REG_LCR, lcr | LCR_DLAB);
  587                 uart_barrier(bas);
  588                 divisor = uart_getreg(bas, REG_DLL) |
  589                     (uart_getreg(bas, REG_DLH) << 8);
  590                 uart_barrier(bas);
  591                 uart_setreg(bas, REG_LCR, lcr);
  592                 uart_barrier(bas);
  593                 baudrate = (divisor > 0) ? bas->rclk / divisor / 16 : 0;
  594                 delay_changed = 1;
  595                 if (baudrate > 0)
  596                         *(int*)data = baudrate;
  597                 else
  598                         error = ENXIO;
  599                 break;
  600         default:
  601                 error = EINVAL;
  602                 break;
  603         }
  604         uart_unlock(sc->sc_hwmtx);
  605         return (error);
  606 }
  607 
  608 
  609 static int
  610 oct16550_bus_ipend(struct uart_softc *sc)
  611 {
  612         struct uart_bas *bas;
  613         int ipend = 0;
  614         uint8_t iir, lsr;
  615 
  616         bas = &sc->sc_bas;
  617         uart_lock(sc->sc_hwmtx);
  618 
  619         iir = uart_getreg(bas, REG_IIR) & IIR_IMASK;
  620         if (iir != IIR_NOPEND) {
  621 
  622                 if (iir == IIR_RLS) {
  623                         lsr = uart_getreg(bas, REG_LSR);
  624                         if (lsr & LSR_OE)
  625                                 ipend |= SER_INT_OVERRUN;
  626                         if (lsr & LSR_BI)
  627                                 ipend |= SER_INT_BREAK;
  628                         if (lsr & LSR_RXRDY)
  629                                 ipend |= SER_INT_RXREADY;
  630 
  631                 } else if (iir == IIR_RXRDY) {
  632                         ipend |= SER_INT_RXREADY;
  633 
  634                 } else if (iir == IIR_RXTOUT) {
  635                         ipend |= SER_INT_RXREADY;
  636 
  637                 } else if (iir == IIR_TXRDY) {
  638                         ipend |= SER_INT_TXIDLE;
  639 
  640                 } else if (iir == IIR_MLSC) {
  641                         ipend |= SER_INT_SIGCHG;
  642 
  643                 } else if (iir == IIR_BUSY) {
  644                         (void) uart_getreg(bas, REG_USR);
  645                 }
  646         }
  647         uart_unlock(sc->sc_hwmtx);
  648 
  649 //#define OCTEON_VISUAL_UART 1
  650 #ifdef OCTEON_VISUAL_UART
  651         static int where1 = 0;
  652 
  653         if (ipend)      octeon_led_run_wheel(&where1, 6 + device_get_unit(sc->sc_dev));
  654 #endif
  655 
  656         return ((sc->sc_leaving) ? 0 : ipend);
  657 }
  658 
  659 
  660 
  661 
  662 static int
  663 oct16550_bus_param (struct uart_softc *sc, int baudrate, int databits,
  664     int stopbits, int parity)
  665 {
  666         struct uart_bas *bas;
  667         int error;
  668 
  669         bas = &sc->sc_bas;
  670         uart_lock(sc->sc_hwmtx);
  671         error = oct16550_param(bas, baudrate, databits, stopbits, parity);
  672         uart_unlock(sc->sc_hwmtx);
  673         return (error);
  674 }
  675 
  676 static int
  677 oct16550_bus_probe (struct uart_softc *sc)
  678 {
  679         struct uart_bas *bas;
  680         int error;
  681 
  682         bas = &sc->sc_bas;
  683         bas->rclk = uart_oct16550_class.uc_rclk = cvmx_sysinfo_get()->cpu_clock_hz;
  684 
  685         error = oct16550_probe(bas);
  686         if (error) {
  687                 return (error);
  688         }
  689 
  690         uart_setreg(bas, REG_MCR, (MCR_DTR | MCR_RTS));
  691 
  692         /*
  693          * Enable FIFOs. And check that the UART has them. If not, we're
  694          * done. Since this is the first time we enable the FIFOs, we reset
  695          * them.
  696          */
  697         oct16550_drain(bas, UART_DRAIN_TRANSMITTER);
  698 #define ENABLE_OCTEON_FIFO 1
  699 #ifdef ENABLE_OCTEON_FIFO
  700         uart_setreg(bas, REG_FCR, FCR_ENABLE | FCR_XMT_RST | FCR_RCV_RST);
  701 #endif
  702         uart_barrier(bas);
  703 
  704         oct16550_flush(bas, UART_FLUSH_RECEIVER|UART_FLUSH_TRANSMITTER);
  705 
  706         if (device_get_unit(sc->sc_dev)) {
  707                 device_set_desc(sc->sc_dev, "Octeon-16550 channel 1");
  708         } else {
  709                 device_set_desc(sc->sc_dev, "Octeon-16550 channel 0");
  710         }
  711 #ifdef ENABLE_OCTEON_FIFO
  712         sc->sc_rxfifosz = 64;
  713         sc->sc_txfifosz = 64;
  714 #else
  715         sc->sc_rxfifosz = 1;
  716         sc->sc_txfifosz = 1;
  717 #endif
  718 
  719 
  720 #if 0
  721         /*
  722          * XXX there are some issues related to hardware flow control and
  723          * it's likely that uart(4) is the cause. This basicly needs more
  724          * investigation, but we avoid using for hardware flow control
  725          * until then.
  726          */
  727         /* 16650s or higher have automatic flow control. */
  728         if (sc->sc_rxfifosz > 16) {
  729                 sc->sc_hwiflow = 1;
  730                 sc->sc_hwoflow = 1;
  731         }
  732 #endif
  733 
  734         return (0);
  735 }
  736 
  737 static int
  738 oct16550_bus_receive (struct uart_softc *sc)
  739 {
  740         struct uart_bas *bas;
  741         int xc;
  742         uint8_t lsr;
  743 
  744         bas = &sc->sc_bas;
  745         uart_lock(sc->sc_hwmtx);
  746         lsr = uart_getreg(bas, REG_LSR);
  747 
  748         while (lsr & LSR_RXRDY) {
  749                 if (uart_rx_full(sc)) {
  750                         sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
  751                         break;
  752                 }
  753                 xc = uart_getreg(bas, REG_DATA);
  754                 if (lsr & LSR_FE)
  755                         xc |= UART_STAT_FRAMERR;
  756                 if (lsr & LSR_PE)
  757                         xc |= UART_STAT_PARERR;
  758                 uart_rx_put(sc, xc);
  759                 lsr = uart_getreg(bas, REG_LSR);
  760         }
  761         /* Discard everything left in the Rx FIFO. */
  762         /*
  763          * First do a dummy read/discard anyway, in case the UART was lying to us.
  764          * This problem was seen on board, when IIR said RBR, but LSR said no RXRDY
  765          * Results in a stuck ipend loop.
  766          */
  767         (void)uart_getreg(bas, REG_DATA);
  768         while (lsr & LSR_RXRDY) {
  769                 (void)uart_getreg(bas, REG_DATA);
  770                 uart_barrier(bas);
  771                 lsr = uart_getreg(bas, REG_LSR);
  772         }
  773         uart_unlock(sc->sc_hwmtx);
  774         return (0);
  775 }
  776 
  777 static int
  778 oct16550_bus_setsig (struct uart_softc *sc, int sig)
  779 {
  780         struct oct16550_softc *oct16550 = (struct oct16550_softc*)sc;
  781         struct uart_bas *bas;
  782         uint32_t new, old;
  783 
  784         bas = &sc->sc_bas;
  785         do {
  786                 old = sc->sc_hwsig;
  787                 new = old;
  788                 if (sig & SER_DDTR) {
  789                         SIGCHG(sig & SER_DTR, new, SER_DTR,
  790                             SER_DDTR);
  791                 }
  792                 if (sig & SER_DRTS) {
  793                         SIGCHG(sig & SER_RTS, new, SER_RTS,
  794                             SER_DRTS);
  795                 }
  796         } while (!atomic_cmpset_32(&sc->sc_hwsig, old, new));
  797         uart_lock(sc->sc_hwmtx);
  798         oct16550->mcr &= ~(MCR_DTR|MCR_RTS);
  799         if (new & SER_DTR)
  800                 oct16550->mcr |= MCR_DTR;
  801         if (new & SER_RTS)
  802                 oct16550->mcr |= MCR_RTS;
  803         uart_setreg(bas, REG_MCR, oct16550->mcr);
  804         uart_barrier(bas);
  805         uart_unlock(sc->sc_hwmtx);
  806         return (0);
  807 }
  808 
  809 static int
  810 oct16550_bus_transmit (struct uart_softc *sc)
  811 {
  812         struct oct16550_softc *oct16550 = (struct oct16550_softc*)sc;
  813         struct uart_bas *bas;
  814         int i;
  815 
  816         bas = &sc->sc_bas;
  817         uart_lock(sc->sc_hwmtx);
  818 #ifdef NO_UART_INTERRUPTS
  819         for (i = 0; i < sc->sc_txdatasz; i++) {
  820             oct16550_putc(bas, sc->sc_txbuf[i]);
  821         }
  822 #else
  823 
  824         oct16550_wait_txhr_empty(bas, 100, oct16550_delay(bas));
  825         uart_setreg(bas, REG_IER, oct16550->ier | IER_ETXRDY);
  826         uart_barrier(bas);
  827 
  828         for (i = 0; i < sc->sc_txdatasz; i++) {
  829                 uart_setreg(bas, REG_DATA, sc->sc_txbuf[i]);
  830                 uart_barrier(bas);
  831         }
  832         sc->sc_txbusy = 1;
  833 #endif
  834         uart_unlock(sc->sc_hwmtx);
  835         return (0);
  836 }

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