jz4780_smb.c

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    1 /*-
    2  * Copyright (c) 2016 Jared McNeill <jmcneill@invisible.ca>
    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  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  *
   14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   19  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   20  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   21  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   22  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   24  * SUCH DAMAGE.
   25  *
   26  * $FreeBSD$
   27  */
   28 
   29 /*
   30  * Ingenic JZ4780 SMB Controller
   31  */
   32 
   33 #include <sys/cdefs.h>
   34 __FBSDID("$FreeBSD$");
   35 
   36 #include <sys/param.h>
   37 #include <sys/systm.h>
   38 #include <sys/bus.h>
   39 #include <sys/rman.h>
   40 #include <sys/kernel.h>
   41 #include <sys/module.h>
   42 #include <sys/time.h>
   43 #include <machine/bus.h>
   44 
   45 #include <dev/ofw/ofw_bus.h>
   46 #include <dev/ofw/ofw_bus_subr.h>
   47 
   48 #include <dev/iicbus/iiconf.h>
   49 #include <dev/iicbus/iicbus.h>
   50 
   51 #include <dev/extres/clk/clk.h>
   52 
   53 #include <mips/ingenic/jz4780_smb.h>
   54 
   55 #include "iicbus_if.h"
   56 
   57 #define JZSMB_TIMEOUT                   ((300UL * hz) / 1000)
   58 
   59 #define JZSMB_SPEED_STANDARD            100000
   60 #define JZSMB_SETUP_TIME_STANDARD       300
   61 #define JZSMB_HOLD_TIME_STANDARD        400
   62 #define JZSMB_PERIOD_MIN_STANDARD       4000
   63 #define JZSMB_PERIOD_MAX_STANDARD       4700
   64 
   65 #define JZSMB_SPEED_FAST                400000
   66 #define JZSMB_SETUP_TIME_FAST           450
   67 #define JZSMB_HOLD_TIME_FAST            450
   68 #define JZSMB_PERIOD_MIN_FAST           600
   69 #define JZSMB_PERIOD_MAX_FAST           1300
   70 
   71 #define JZSMB_HCNT_BASE                 8
   72 #define JZSMB_HCNT_MIN                  6
   73 #define JZSMB_LCNT_BASE                 1
   74 #define JZSMB_LCNT_MIN                  8
   75 
   76 static inline int
   77 tstohz(const struct timespec *tsp)
   78 {
   79         struct timeval tv;
   80 
   81         TIMESPEC_TO_TIMEVAL(&tv, tsp);
   82         return (tvtohz(&tv));
   83 }
   84 
   85 static struct ofw_compat_data compat_data[] = {
   86         { "ingenic,jz4780-i2c",         1 },
   87         { NULL,                         0 }
   88 };
   89 
   90 static struct resource_spec jzsmb_spec[] = {
   91         { SYS_RES_MEMORY,       0,      RF_ACTIVE },
   92         { -1, 0 }
   93 };
   94 
   95 struct jzsmb_softc {
   96         struct resource *res;
   97         struct mtx      mtx;
   98         clk_t           clk;
   99         device_t        iicbus;
  100         int             busy;
  101         uint32_t        i2c_freq;
  102         uint64_t        bus_freq;
  103         uint32_t        status;
  104 
  105         struct iic_msg  *msg;
  106 };
  107 
  108 #define SMB_LOCK(sc)                    mtx_lock(&(sc)->mtx)
  109 #define SMB_UNLOCK(sc)                  mtx_unlock(&(sc)->mtx)
  110 #define SMB_ASSERT_LOCKED(sc)           mtx_assert(&(sc)->mtx, MA_OWNED)
  111 #define SMB_READ(sc, reg)               bus_read_2((sc)->res, (reg))
  112 #define SMB_WRITE(sc, reg, val)         bus_write_2((sc)->res, (reg), (val))
  113 
  114 static phandle_t
  115 jzsmb_get_node(device_t bus, device_t dev)
  116 {
  117         return (ofw_bus_get_node(bus));
  118 }
  119 
  120 static int
  121 jzsmb_enable(struct jzsmb_softc *sc, int enable)
  122 {
  123         SMB_ASSERT_LOCKED(sc);
  124 
  125         if (enable) {
  126                 SMB_WRITE(sc, SMBENB, SMBENB_SMBENB);
  127                 while ((SMB_READ(sc, SMBENBST) & SMBENBST_SMBEN) == 0)
  128                         ;
  129         } else {
  130                 SMB_WRITE(sc, SMBENB, 0);
  131                 while ((SMB_READ(sc, SMBENBST) & SMBENBST_SMBEN) != 0)
  132                         ;
  133         }
  134 
  135         return (0);
  136 }
  137 
  138 static int
  139 jzsmb_reset_locked(device_t dev, u_char addr)
  140 {
  141         struct jzsmb_softc *sc;
  142         uint16_t con;
  143         uint32_t period;
  144         int hcnt, lcnt, setup_time, hold_time;
  145 
  146         sc = device_get_softc(dev);
  147 
  148         SMB_ASSERT_LOCKED(sc);
  149 
  150         /* Setup master mode operation */
  151 
  152         /* Disable SMB */
  153         jzsmb_enable(sc, 0);
  154 
  155         /* Disable interrupts */
  156         SMB_WRITE(sc, SMBINTM, 0);
  157 
  158         /* Set supported speed mode and expected SCL frequency */
  159         period = sc->bus_freq / sc->i2c_freq;
  160         con = SMBCON_REST | SMBCON_SLVDIS | SMBCON_MD;
  161         switch (sc->i2c_freq) {
  162         case JZSMB_SPEED_STANDARD:
  163                 con |= SMBCON_SPD_STANDARD;
  164                 setup_time = JZSMB_SETUP_TIME_STANDARD;
  165                 hold_time = JZSMB_HOLD_TIME_STANDARD;
  166                 hcnt = (period * JZSMB_PERIOD_MIN_STANDARD) /
  167                     (JZSMB_PERIOD_MAX_STANDARD + JZSMB_PERIOD_MIN_STANDARD);
  168                 lcnt = period - hcnt;
  169                 hcnt = MAX(hcnt - JZSMB_HCNT_BASE, JZSMB_HCNT_MIN);
  170                 lcnt = MAX(lcnt - JZSMB_LCNT_BASE, JZSMB_LCNT_MIN);
  171                 SMB_WRITE(sc, SMBCON, con);
  172                 SMB_WRITE(sc, SMBSHCNT, hcnt);
  173                 SMB_WRITE(sc, SMBSLCNT, lcnt);
  174                 break;
  175         case JZSMB_SPEED_FAST:
  176                 con |= SMBCON_SPD_FAST;
  177                 setup_time = JZSMB_SETUP_TIME_FAST;
  178                 hold_time = JZSMB_HOLD_TIME_FAST;
  179                 hcnt = (period * JZSMB_PERIOD_MIN_FAST) /
  180                     (JZSMB_PERIOD_MAX_FAST + JZSMB_PERIOD_MIN_FAST);
  181                 lcnt = period - hcnt;
  182                 hcnt = MAX(hcnt - JZSMB_HCNT_BASE, JZSMB_HCNT_MIN);
  183                 lcnt = MAX(lcnt - JZSMB_LCNT_BASE, JZSMB_LCNT_MIN);
  184                 SMB_WRITE(sc, SMBCON, con);
  185                 SMB_WRITE(sc, SMBFHCNT, hcnt);
  186                 SMB_WRITE(sc, SMBFLCNT, lcnt);
  187                 break;
  188         default:
  189                 return (EINVAL);
  190         }
  191 
  192         setup_time = ((setup_time * sc->bus_freq / 1000) / 1000000) + 1;
  193         setup_time = MIN(1, MAX(255, setup_time));
  194         SMB_WRITE(sc, SMBSDASU, setup_time);
  195 
  196         hold_time = ((hold_time * sc->bus_freq / 1000) / 1000000) - 1;
  197         hold_time = MAX(255, hold_time);
  198         if (hold_time >= 0)
  199                 SMB_WRITE(sc, SMBSDAHD, hold_time | SMBSDAHD_HDENB);
  200         else
  201                 SMB_WRITE(sc, SMBSDAHD, 0);
  202 
  203         SMB_WRITE(sc, SMBTAR, addr >> 1);
  204 
  205         if (addr != 0) {
  206                 /* Enable SMB */
  207                 jzsmb_enable(sc, 1);
  208         }
  209 
  210         return (0);
  211 }
  212 
  213 static int
  214 jzsmb_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
  215 {
  216         struct jzsmb_softc *sc;
  217         int error;
  218 
  219         sc = device_get_softc(dev);
  220 
  221         SMB_LOCK(sc);
  222         error = jzsmb_reset_locked(dev, addr);
  223         SMB_UNLOCK(sc);
  224 
  225         return (error);
  226 }
  227 
  228 static int
  229 jzsmb_transfer_read(device_t dev, struct iic_msg *msg)
  230 {
  231         struct jzsmb_softc *sc;
  232         struct timespec start, diff;
  233         uint16_t con, resid;
  234         int timeo;
  235 
  236         sc = device_get_softc(dev);
  237         timeo = JZSMB_TIMEOUT * msg->len;
  238 
  239         SMB_ASSERT_LOCKED(sc);
  240 
  241         con = SMB_READ(sc, SMBCON);
  242         con |= SMBCON_STPHLD;
  243         SMB_WRITE(sc, SMBCON, con);
  244 
  245         getnanouptime(&start);
  246         for (resid = msg->len; resid > 0; resid--) {
  247                 for (int i = 0; i < min(resid, 8); i++)
  248                         SMB_WRITE(sc, SMBDC, SMBDC_CMD);
  249                 for (;;) {
  250                         getnanouptime(&diff);
  251                         timespecsub(&diff, &start, &diff);
  252                         if ((SMB_READ(sc, SMBST) & SMBST_RFNE) != 0) {
  253                                 msg->buf[msg->len - resid] =
  254                                     SMB_READ(sc, SMBDC) & SMBDC_DAT;
  255                                 break;
  256                         } else
  257                                 DELAY(1000);
  258 
  259                         if (tstohz(&diff) >= timeo) {
  260                                 device_printf(dev,
  261                                     "read timeout (status=0x%02x)\n",
  262                                     SMB_READ(sc, SMBST));
  263                                 return (EIO);
  264                         }
  265                 }
  266         }
  267 
  268         con = SMB_READ(sc, SMBCON);
  269         con &= ~SMBCON_STPHLD;
  270         SMB_WRITE(sc, SMBCON, con);
  271 
  272         return (0);
  273 }
  274 
  275 static int
  276 jzsmb_transfer_write(device_t dev, struct iic_msg *msg, int stop_hold)
  277 {
  278         struct jzsmb_softc *sc;
  279         struct timespec start, diff;
  280         uint16_t con, resid;
  281         int timeo;
  282 
  283         sc = device_get_softc(dev);
  284         timeo = JZSMB_TIMEOUT * msg->len;
  285 
  286         SMB_ASSERT_LOCKED(sc);
  287 
  288         con = SMB_READ(sc, SMBCON);
  289         con |= SMBCON_STPHLD;
  290         SMB_WRITE(sc, SMBCON, con);
  291 
  292         getnanouptime(&start);
  293         for (resid = msg->len; resid > 0; resid--) {
  294                 for (;;) {
  295                         getnanouptime(&diff);
  296                         timespecsub(&diff, &start, &diff);
  297                         if ((SMB_READ(sc, SMBST) & SMBST_TFNF) != 0) {
  298                                 SMB_WRITE(sc, SMBDC,
  299                                     msg->buf[msg->len - resid]);
  300                                 break;
  301                         } else
  302                                 DELAY((1000 * hz) / JZSMB_TIMEOUT);
  303 
  304                         if (tstohz(&diff) >= timeo) {
  305                                 device_printf(dev,
  306                                     "write timeout (status=0x%02x)\n",
  307                                     SMB_READ(sc, SMBST));
  308                                 return (EIO);
  309                         }
  310                 }
  311         }
  312 
  313         if (!stop_hold) {
  314                 con = SMB_READ(sc, SMBCON);
  315                 con &= ~SMBCON_STPHLD;
  316                 SMB_WRITE(sc, SMBCON, con);
  317         }
  318 
  319         return (0);
  320 }
  321 
  322 static int
  323 jzsmb_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
  324 {
  325         struct jzsmb_softc *sc;
  326         uint32_t n;
  327         uint16_t con;
  328         int error;
  329 
  330         sc = device_get_softc(dev);
  331 
  332         SMB_LOCK(sc);
  333         while (sc->busy)
  334                 mtx_sleep(sc, &sc->mtx, 0, "i2cbuswait", 0);
  335         sc->busy = 1;
  336         sc->status = 0;
  337 
  338         for (n = 0; n < nmsgs; n++) {
  339                 /* Set target address */
  340                 if (n == 0 || msgs[n].slave != msgs[n - 1].slave)
  341                         jzsmb_reset_locked(dev, msgs[n].slave);
  342 
  343                 /* Set read or write */
  344                 if ((msgs[n].flags & IIC_M_RD) != 0)
  345                         error = jzsmb_transfer_read(dev, &msgs[n]);
  346                 else
  347                         error = jzsmb_transfer_write(dev, &msgs[n],
  348                             n < nmsgs - 1);
  349 
  350                 if (error != 0)
  351                         goto done;
  352         }
  353 
  354 done:
  355         /* Send stop if necessary */
  356         con = SMB_READ(sc, SMBCON);
  357         con &= ~SMBCON_STPHLD;
  358         SMB_WRITE(sc, SMBCON, con);
  359 
  360         /* Disable SMB */
  361         jzsmb_enable(sc, 0);
  362 
  363         sc->msg = NULL;
  364         sc->busy = 0;
  365         wakeup(sc);
  366         SMB_UNLOCK(sc);
  367 
  368         return (error);
  369 }
  370 
  371 static int
  372 jzsmb_probe(device_t dev)
  373 {
  374         if (!ofw_bus_status_okay(dev))
  375                 return (ENXIO);
  376 
  377         if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
  378                 return (ENXIO);
  379 
  380         device_set_desc(dev, "Ingenic JZ4780 SMB Controller");
  381 
  382         return (BUS_PROBE_DEFAULT);
  383 }
  384 
  385 static int
  386 jzsmb_attach(device_t dev)
  387 {
  388         struct jzsmb_softc *sc;
  389         phandle_t node;
  390         int error;
  391 
  392         sc = device_get_softc(dev);
  393         node = ofw_bus_get_node(dev);
  394         mtx_init(&sc->mtx, device_get_nameunit(dev), "jzsmb", MTX_DEF);
  395 
  396         error = clk_get_by_ofw_index(dev, 0, 0, &sc->clk);
  397         if (error != 0) {
  398                 device_printf(dev, "cannot get clock\n");
  399                 goto fail;
  400         }
  401         error = clk_enable(sc->clk);
  402         if (error != 0) {
  403                 device_printf(dev, "cannot enable clock\n");
  404                 goto fail;
  405         }
  406         error = clk_get_freq(sc->clk, &sc->bus_freq);
  407         if (error != 0 || sc->bus_freq == 0) {
  408                 device_printf(dev, "cannot get bus frequency\n");
  409                 return (error);
  410         }
  411 
  412         if (bus_alloc_resources(dev, jzsmb_spec, &sc->res) != 0) {
  413                 device_printf(dev, "cannot allocate resources for device\n");
  414                 error = ENXIO;
  415                 goto fail;
  416         }
  417 
  418         if (OF_getencprop(node, "clock-frequency", &sc->i2c_freq,
  419             sizeof(sc->i2c_freq)) != 0 || sc->i2c_freq == 0)
  420                 sc->i2c_freq = 100000;  /* Default to standard mode */
  421 
  422         sc->iicbus = device_add_child(dev, "iicbus", -1);
  423         if (sc->iicbus == NULL) {
  424                 device_printf(dev, "cannot add iicbus child device\n");
  425                 error = ENXIO;
  426                 goto fail;
  427         }
  428 
  429         bus_generic_attach(dev);
  430 
  431         return (0);
  432 
  433 fail:
  434         bus_release_resources(dev, jzsmb_spec, &sc->res);
  435         if (sc->clk != NULL)
  436                 clk_release(sc->clk);
  437         mtx_destroy(&sc->mtx);
  438         return (error);
  439 }
  440 
  441 static device_method_t jzsmb_methods[] = {
  442         /* Device interface */
  443         DEVMETHOD(device_probe,         jzsmb_probe),
  444         DEVMETHOD(device_attach,        jzsmb_attach),
  445 
  446         /* Bus interface */
  447         DEVMETHOD(bus_setup_intr,       bus_generic_setup_intr),
  448         DEVMETHOD(bus_teardown_intr,    bus_generic_teardown_intr),
  449         DEVMETHOD(bus_alloc_resource,   bus_generic_alloc_resource),
  450         DEVMETHOD(bus_release_resource, bus_generic_release_resource),
  451         DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
  452         DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
  453         DEVMETHOD(bus_adjust_resource,  bus_generic_adjust_resource),
  454         DEVMETHOD(bus_set_resource,     bus_generic_rl_set_resource),
  455         DEVMETHOD(bus_get_resource,     bus_generic_rl_get_resource),
  456 
  457         /* OFW methods */
  458         DEVMETHOD(ofw_bus_get_node,     jzsmb_get_node),
  459 
  460         /* iicbus interface */
  461         DEVMETHOD(iicbus_callback,      iicbus_null_callback),
  462         DEVMETHOD(iicbus_reset,         jzsmb_reset),
  463         DEVMETHOD(iicbus_transfer,      jzsmb_transfer),
  464 
  465         DEVMETHOD_END
  466 };
  467 
  468 static driver_t jzsmb_driver = {
  469         "iichb",
  470         jzsmb_methods,
  471         sizeof(struct jzsmb_softc),
  472 };
  473 
  474 static devclass_t jzsmb_devclass;
  475 
  476 EARLY_DRIVER_MODULE(iicbus, jzsmb, iicbus_driver, iicbus_devclass, 0, 0,
  477     BUS_PASS_RESOURCE + BUS_PASS_ORDER_MIDDLE);
  478 EARLY_DRIVER_MODULE(jzsmb, simplebus, jzsmb_driver, jzsmb_devclass, 0, 0,
  479     BUS_PASS_RESOURCE + BUS_PASS_ORDER_MIDDLE);
  480 MODULE_VERSION(jzsmb, 1);
Cache object: 596f4a5bb4b53adf1c526ad8a0b848fb
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FreeBSD/Linux Kernel Cross Reference sys/mips/ingenic/jz4780_smb.c

FreeBSD/Linux Kernel Cross Reference
sys/mips/ingenic/jz4780_smb.c
