The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/arm/allwinner/aw_rsb.c

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    1 /*-
    2  * Copyright (c) 2016 Jared McNeill <jmcneill@invisible.ca>
    3  *
    4  * Redistribution and use in source and binary forms, with or without
    5  * modification, are permitted provided that the following conditions
    6  * are met:
    7  * 1. Redistributions of source code must retain the above copyright
    8  *    notice, this list of conditions and the following disclaimer.
    9  * 2. Redistributions in binary form must reproduce the above copyright
   10  *    notice, this list of conditions and the following disclaimer in the
   11  *    documentation and/or other materials provided with the distribution.
   12  *
   13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   15  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   16  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   17  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   18  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   19  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   20  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   21  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   23  * SUCH DAMAGE.
   24  *
   25  * $FreeBSD$
   26  */
   27 
   28 /*
   29  * Allwinner RSB (Reduced Serial Bus) and P2WI (Push-Pull Two Wire Interface)
   30  */
   31 
   32 #include <sys/cdefs.h>
   33 __FBSDID("$FreeBSD$");
   34 
   35 #include <sys/param.h>
   36 #include <sys/systm.h>
   37 #include <sys/bus.h>
   38 #include <sys/rman.h>
   39 #include <sys/kernel.h>
   40 #include <sys/lock.h>
   41 #include <sys/module.h>
   42 #include <sys/mutex.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 #include <dev/extres/hwreset/hwreset.h>
   53 
   54 #include "iicbus_if.h"
   55 
   56 #define RSB_CTRL                0x00
   57 #define  START_TRANS            (1 << 7)
   58 #define  GLOBAL_INT_ENB         (1 << 1)
   59 #define  SOFT_RESET             (1 << 0)
   60 #define RSB_CCR         0x04
   61 #define RSB_INTE                0x08
   62 #define RSB_INTS                0x0c
   63 #define  INT_TRANS_ERR_ID(x)    (((x) >> 8) & 0xf)
   64 #define  INT_LOAD_BSY           (1 << 2)
   65 #define  INT_TRANS_ERR          (1 << 1)
   66 #define  INT_TRANS_OVER         (1 << 0)
   67 #define  INT_MASK               (INT_LOAD_BSY|INT_TRANS_ERR|INT_TRANS_OVER)
   68 #define RSB_DADDR0              0x10
   69 #define RSB_DADDR1              0x14
   70 #define RSB_DLEN                0x18
   71 #define  DLEN_READ              (1 << 4)
   72 #define RSB_DATA0               0x1c
   73 #define RSB_DATA1               0x20
   74 #define RSB_PMCR                0x28
   75 #define  RSB_PMCR_START         (1 << 31)
   76 #define  RSB_PMCR_DATA(x)       (x << 16)
   77 #define  RSB_PMCR_REG(x)        (x << 8)
   78 #define RSB_CMD                 0x2c
   79 #define  CMD_SRTA               0xe8
   80 #define  CMD_RD8                0x8b
   81 #define  CMD_RD16               0x9c
   82 #define  CMD_RD32               0xa6
   83 #define  CMD_WR8                0x4e
   84 #define  CMD_WR16               0x59
   85 #define  CMD_WR32               0x63
   86 #define RSB_DAR                 0x30
   87 #define  DAR_RTA                (0xff << 16)
   88 #define  DAR_RTA_SHIFT          16
   89 #define  DAR_DA                 (0xffff << 0)
   90 #define  DAR_DA_SHIFT           0
   91 
   92 #define RSB_MAXLEN              8
   93 #define RSB_RESET_RETRY         100
   94 #define RSB_I2C_TIMEOUT         hz
   95 
   96 #define RSB_ADDR_PMIC_PRIMARY   0x3a3
   97 #define RSB_ADDR_PMIC_SECONDARY 0x745
   98 #define RSB_ADDR_PERIPH_IC      0xe89
   99 
  100 #define PMIC_MODE_REG   0x3e
  101 #define PMIC_MODE_I2C   0x00
  102 #define PMIC_MODE_RSB   0x7c
  103 
  104 #define A31_P2WI        1
  105 #define A23_RSB         2
  106 
  107 static struct ofw_compat_data compat_data[] = {
  108         { "allwinner,sun6i-a31-p2wi",           A31_P2WI },
  109         { "allwinner,sun8i-a23-rsb",            A23_RSB },
  110         { NULL,                                 0 }
  111 };
  112 
  113 static struct resource_spec rsb_spec[] = {
  114         { SYS_RES_MEMORY,       0,      RF_ACTIVE },
  115         { -1, 0 }
  116 };
  117 
  118 /*
  119  * Device address to Run-time address mappings.
  120  *
  121  * Run-time address (RTA) is an 8-bit value used to address the device during
  122  * a read or write transaction. The following are valid RTAs:
  123  *  0x17 0x2d 0x3a 0x4e 0x59 0x63 0x74 0x8b 0x9c 0xa6 0xb1 0xc5 0xd2 0xe8 0xff
  124  *
  125  * Allwinner uses RTA 0x2d for the primary PMIC, 0x3a for the secondary PMIC,
  126  * and 0x4e for the peripheral IC (where applicable).
  127  */
  128 static const struct {
  129         uint16_t        addr;
  130         uint8_t         rta;
  131 } rsb_rtamap[] = {
  132         { .addr = RSB_ADDR_PMIC_PRIMARY,        .rta = 0x2d },
  133         { .addr = RSB_ADDR_PMIC_SECONDARY,      .rta = 0x3a },
  134         { .addr = RSB_ADDR_PERIPH_IC,           .rta = 0x4e },
  135         { .addr = 0,                            .rta = 0 }
  136 };
  137 
  138 struct rsb_softc {
  139         struct resource *res;
  140         struct mtx      mtx;
  141         clk_t           clk;
  142         hwreset_t       rst;
  143         device_t        iicbus;
  144         int             busy;
  145         uint32_t        status;
  146         uint16_t        cur_addr;
  147         int             type;
  148 
  149         struct iic_msg  *msg;
  150 };
  151 
  152 #define RSB_LOCK(sc)                    mtx_lock(&(sc)->mtx)
  153 #define RSB_UNLOCK(sc)                  mtx_unlock(&(sc)->mtx)
  154 #define RSB_ASSERT_LOCKED(sc)           mtx_assert(&(sc)->mtx, MA_OWNED)
  155 #define RSB_READ(sc, reg)               bus_read_4((sc)->res, (reg))
  156 #define RSB_WRITE(sc, reg, val) bus_write_4((sc)->res, (reg), (val))
  157 
  158 static phandle_t
  159 rsb_get_node(device_t bus, device_t dev)
  160 {
  161         return (ofw_bus_get_node(bus));
  162 }
  163 
  164 static int
  165 rsb_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
  166 {
  167         struct rsb_softc *sc;
  168         int retry;
  169 
  170         sc = device_get_softc(dev);
  171 
  172         RSB_LOCK(sc);
  173 
  174         /* Write soft-reset bit and wait for it to self-clear. */
  175         RSB_WRITE(sc, RSB_CTRL, SOFT_RESET);
  176         for (retry = RSB_RESET_RETRY; retry > 0; retry--)
  177                 if ((RSB_READ(sc, RSB_CTRL) & SOFT_RESET) == 0)
  178                         break;
  179 
  180         RSB_UNLOCK(sc);
  181 
  182         if (retry == 0) {
  183                 device_printf(dev, "soft reset timeout\n");
  184                 return (ETIMEDOUT);
  185         }
  186 
  187         return (IIC_ENOADDR);
  188 }
  189 
  190 static uint32_t
  191 rsb_encode(const uint8_t *buf, u_int len, u_int off)
  192 {
  193         uint32_t val;
  194         u_int n;
  195 
  196         val = 0;
  197         for (n = off; n < MIN(len, 4 + off); n++)
  198                 val |= ((uint32_t)buf[n] << ((n - off) * NBBY));
  199 
  200         return val;
  201 }
  202 
  203 static void
  204 rsb_decode(const uint32_t val, uint8_t *buf, u_int len, u_int off)
  205 {
  206         u_int n;
  207 
  208         for (n = off; n < MIN(len, 4 + off); n++)
  209                 buf[n] = (val >> ((n - off) * NBBY)) & 0xff;
  210 }
  211 
  212 static int
  213 rsb_start(device_t dev)
  214 {
  215         struct rsb_softc *sc;
  216         int error, retry;
  217 
  218         sc = device_get_softc(dev);
  219 
  220         RSB_ASSERT_LOCKED(sc);
  221 
  222         /* Start the transfer */
  223         RSB_WRITE(sc, RSB_CTRL, GLOBAL_INT_ENB | START_TRANS);
  224 
  225         /* Wait for transfer to complete */
  226         error = ETIMEDOUT;
  227         for (retry = RSB_I2C_TIMEOUT; retry > 0; retry--) {
  228                 sc->status |= RSB_READ(sc, RSB_INTS);
  229                 if ((sc->status & INT_TRANS_OVER) != 0) {
  230                         error = 0;
  231                         break;
  232                 }
  233                 DELAY((1000 * hz) / RSB_I2C_TIMEOUT);
  234         }
  235         if (error == 0 && (sc->status & INT_TRANS_OVER) == 0) {
  236                 device_printf(dev, "transfer error, status 0x%08x\n",
  237                     sc->status);
  238                 error = EIO;
  239         }
  240 
  241         return (error);
  242 
  243 }
  244 
  245 static int
  246 rsb_set_rta(device_t dev, uint16_t addr)
  247 {
  248         struct rsb_softc *sc;
  249         uint8_t rta;
  250         int i;
  251 
  252         sc = device_get_softc(dev);
  253 
  254         RSB_ASSERT_LOCKED(sc);
  255 
  256         /* Lookup run-time address for given device address */
  257         for (rta = 0, i = 0; rsb_rtamap[i].rta != 0; i++)
  258                 if (rsb_rtamap[i].addr == addr) {
  259                         rta = rsb_rtamap[i].rta;
  260                         break;
  261                 }
  262         if (rta == 0) {
  263                 device_printf(dev, "RTA not known for address %#x\n", addr);
  264                 return (ENXIO);
  265         }
  266 
  267         /* Set run-time address */
  268         RSB_WRITE(sc, RSB_INTS, RSB_READ(sc, RSB_INTS));
  269         RSB_WRITE(sc, RSB_DAR, (addr << DAR_DA_SHIFT) | (rta << DAR_RTA_SHIFT));
  270         RSB_WRITE(sc, RSB_CMD, CMD_SRTA);
  271 
  272         return (rsb_start(dev));
  273 }
  274 
  275 static int
  276 rsb_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
  277 {
  278         struct rsb_softc *sc;
  279         uint32_t daddr[2], data[2], dlen;
  280         uint16_t device_addr;
  281         uint8_t cmd;
  282         int error;
  283 
  284         sc = device_get_softc(dev);
  285 
  286         /*
  287          * P2WI and RSB are not really I2C or SMBus controllers, so there are
  288          * some restrictions imposed by the driver.
  289          *
  290          * Transfers must contain exactly two messages. The first is always
  291          * a write, containing a single data byte offset. Data will either
  292          * be read from or written to the corresponding data byte in the
  293          * second message. The slave address in both messages must be the
  294          * same.
  295          */
  296         if (nmsgs != 2 || (msgs[0].flags & IIC_M_RD) == IIC_M_RD ||
  297             (msgs[0].slave >> 1) != (msgs[1].slave >> 1) ||
  298             msgs[0].len != 1 || msgs[1].len > RSB_MAXLEN)
  299                 return (EINVAL);
  300 
  301         /* The RSB controller can read or write 1, 2, or 4 bytes at a time. */
  302         if (sc->type == A23_RSB) {
  303                 if ((msgs[1].flags & IIC_M_RD) != 0) {
  304                         switch (msgs[1].len) {
  305                         case 1:
  306                                 cmd = CMD_RD8;
  307                                 break;
  308                         case 2:
  309                                 cmd = CMD_RD16;
  310                                 break;
  311                         case 4:
  312                                 cmd = CMD_RD32;
  313                                 break;
  314                         default:
  315                                 return (EINVAL);
  316                         }
  317                 } else {
  318                         switch (msgs[1].len) {
  319                         case 1:
  320                                 cmd = CMD_WR8;
  321                                 break;
  322                         case 2:
  323                                 cmd = CMD_WR16;
  324                                 break;
  325                         case 4:
  326                                 cmd = CMD_WR32;
  327                                 break;
  328                         default:
  329                                 return (EINVAL);
  330                         }
  331                 }
  332         }
  333 
  334         RSB_LOCK(sc);
  335         while (sc->busy)
  336                 mtx_sleep(sc, &sc->mtx, 0, "i2cbuswait", 0);
  337         sc->busy = 1;
  338         sc->status = 0;
  339 
  340         /* Select current run-time address if necessary */
  341         if (sc->type == A23_RSB) {
  342                 device_addr = msgs[0].slave >> 1;
  343                 if (sc->cur_addr != device_addr) {
  344                         error = rsb_set_rta(dev, device_addr);
  345                         if (error != 0)
  346                                 goto done;
  347                         sc->cur_addr = device_addr;
  348                         sc->status = 0;
  349                 }
  350         }
  351 
  352         /* Clear interrupt status */
  353         RSB_WRITE(sc, RSB_INTS, RSB_READ(sc, RSB_INTS));
  354 
  355         /* Program data access address registers */
  356         daddr[0] = rsb_encode(msgs[0].buf, msgs[0].len, 0);
  357         RSB_WRITE(sc, RSB_DADDR0, daddr[0]);
  358 
  359         /* Write data */
  360         if ((msgs[1].flags & IIC_M_RD) == 0) {
  361                 data[0] = rsb_encode(msgs[1].buf, msgs[1].len, 0);
  362                 RSB_WRITE(sc, RSB_DATA0, data[0]);
  363         }
  364 
  365         /* Set command type for RSB */
  366         if (sc->type == A23_RSB)
  367                 RSB_WRITE(sc, RSB_CMD, cmd);
  368 
  369         /* Program data length register and transfer direction */
  370         dlen = msgs[0].len - 1;
  371         if ((msgs[1].flags & IIC_M_RD) == IIC_M_RD)
  372                 dlen |= DLEN_READ;
  373         RSB_WRITE(sc, RSB_DLEN, dlen);
  374 
  375         /* Start transfer */
  376         error = rsb_start(dev);
  377         if (error != 0)
  378                 goto done;
  379 
  380         /* Read data */
  381         if ((msgs[1].flags & IIC_M_RD) == IIC_M_RD) {
  382                 data[0] = RSB_READ(sc, RSB_DATA0);
  383                 rsb_decode(data[0], msgs[1].buf, msgs[1].len, 0);
  384         }
  385 
  386 done:
  387         sc->msg = NULL;
  388         sc->busy = 0;
  389         wakeup(sc);
  390         RSB_UNLOCK(sc);
  391 
  392         return (error);
  393 }
  394 
  395 static int
  396 rsb_probe(device_t dev)
  397 {
  398         if (!ofw_bus_status_okay(dev))
  399                 return (ENXIO);
  400 
  401         switch (ofw_bus_search_compatible(dev, compat_data)->ocd_data) {
  402         case A23_RSB:
  403                 device_set_desc(dev, "Allwinner RSB");
  404                 break;
  405         case A31_P2WI:
  406                 device_set_desc(dev, "Allwinner P2WI");
  407                 break;
  408         default:
  409                 return (ENXIO);
  410         }
  411 
  412         return (BUS_PROBE_DEFAULT);
  413 }
  414 
  415 static int
  416 rsb_attach(device_t dev)
  417 {
  418         struct rsb_softc *sc;
  419         int error;
  420 
  421         sc = device_get_softc(dev);
  422         mtx_init(&sc->mtx, device_get_nameunit(dev), "rsb", MTX_DEF);
  423 
  424         sc->type = ofw_bus_search_compatible(dev, compat_data)->ocd_data;
  425 
  426         if (clk_get_by_ofw_index(dev, 0, 0, &sc->clk) == 0) {
  427                 error = clk_enable(sc->clk);
  428                 if (error != 0) {
  429                         device_printf(dev, "cannot enable clock\n");
  430                         goto fail;
  431                 }
  432         }
  433         if (hwreset_get_by_ofw_idx(dev, 0, 0, &sc->rst) == 0) {
  434                 error = hwreset_deassert(sc->rst);
  435                 if (error != 0) {
  436                         device_printf(dev, "cannot de-assert reset\n");
  437                         goto fail;
  438                 }
  439         }
  440 
  441         if (bus_alloc_resources(dev, rsb_spec, &sc->res) != 0) {
  442                 device_printf(dev, "cannot allocate resources for device\n");
  443                 error = ENXIO;
  444                 goto fail;
  445         }
  446 
  447         /* Set the PMIC into RSB mode as ATF might have leave it in I2C mode */
  448         RSB_WRITE(sc, RSB_PMCR, RSB_PMCR_REG(PMIC_MODE_REG) | RSB_PMCR_DATA(PMIC_MODE_RSB) | RSB_PMCR_START);
  449 
  450         sc->iicbus = device_add_child(dev, "iicbus", -1);
  451         if (sc->iicbus == NULL) {
  452                 device_printf(dev, "cannot add iicbus child device\n");
  453                 error = ENXIO;
  454                 goto fail;
  455         }
  456 
  457         bus_generic_attach(dev);
  458 
  459         return (0);
  460 
  461 fail:
  462         bus_release_resources(dev, rsb_spec, &sc->res);
  463         if (sc->rst != NULL)
  464                 hwreset_release(sc->rst);
  465         if (sc->clk != NULL)
  466                 clk_release(sc->clk);
  467         mtx_destroy(&sc->mtx);
  468         return (error);
  469 }
  470 
  471 static device_method_t rsb_methods[] = {
  472         /* Device interface */
  473         DEVMETHOD(device_probe,         rsb_probe),
  474         DEVMETHOD(device_attach,        rsb_attach),
  475 
  476         /* Bus interface */
  477         DEVMETHOD(bus_setup_intr,       bus_generic_setup_intr),
  478         DEVMETHOD(bus_teardown_intr,    bus_generic_teardown_intr),
  479         DEVMETHOD(bus_alloc_resource,   bus_generic_alloc_resource),
  480         DEVMETHOD(bus_release_resource, bus_generic_release_resource),
  481         DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
  482         DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
  483         DEVMETHOD(bus_adjust_resource,  bus_generic_adjust_resource),
  484         DEVMETHOD(bus_set_resource,     bus_generic_rl_set_resource),
  485         DEVMETHOD(bus_get_resource,     bus_generic_rl_get_resource),
  486 
  487         /* OFW methods */
  488         DEVMETHOD(ofw_bus_get_node,     rsb_get_node),
  489 
  490         /* iicbus interface */
  491         DEVMETHOD(iicbus_callback,      iicbus_null_callback),
  492         DEVMETHOD(iicbus_reset,         rsb_reset),
  493         DEVMETHOD(iicbus_transfer,      rsb_transfer),
  494 
  495         DEVMETHOD_END
  496 };
  497 
  498 static driver_t rsb_driver = {
  499         "iichb",
  500         rsb_methods,
  501         sizeof(struct rsb_softc),
  502 };
  503 
  504 EARLY_DRIVER_MODULE(iicbus, rsb, iicbus_driver, 0, 0,
  505     BUS_PASS_SUPPORTDEV + BUS_PASS_ORDER_MIDDLE);
  506 EARLY_DRIVER_MODULE(rsb, simplebus, rsb_driver, 0, 0,
  507     BUS_PASS_SUPPORTDEV + BUS_PASS_ORDER_MIDDLE);
  508 MODULE_VERSION(rsb, 1);
  509 MODULE_DEPEND(rsb, iicbus, 1, 1, 1);
  510 SIMPLEBUS_PNP_INFO(compat_data);

Cache object: c33fe96ac425a219e2d773e34b8fb95e


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