ow_temp.c

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    1 /*-
    2  * Copyright (c) 2015 M. Warner Losh <imp@FreeBSD.org>
    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 unmodified, this list of conditions, and the following
    9  *    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, BUT
   19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   24  */
   25 
   26 #include <sys/cdefs.h>
   27 __FBSDID("$FreeBSD$");
   28 
   29 #include <sys/param.h>
   30 #include <sys/systm.h>
   31 #include <sys/kernel.h>
   32 
   33 #include <sys/bus.h>
   34 #include <sys/errno.h>
   35 #include <sys/libkern.h>
   36 #include <sys/kthread.h>
   37 #include <sys/malloc.h>
   38 #include <sys/module.h>
   39 #include <sys/mutex.h>
   40 #include <sys/proc.h>
   41 #include <sys/sysctl.h>
   42 
   43 #include <dev/ow/ow.h>
   44 #include <dev/ow/own.h>
   45 
   46 #define OWT_DS1820      0x10            /* Also 18S20 */
   47 #define OWT_DS1822      0x22            /* Very close to 18B20 */
   48 #define OWT_DS18B20     0x28            /* Also MAX31820 */
   49 #define OWT_DS1825      0x3B            /* Just like 18B20 with address bits */
   50 
   51 #define CONVERT_T               0x44
   52 #define COPY_SCRATCHPAD         0x48
   53 #define WRITE_SCRATCHPAD        0x4e
   54 #define READ_POWER_SUPPLY       0xb4
   55 #define RECALL_EE               0xb8
   56 #define READ_SCRATCHPAD         0xbe
   57 
   58 #define OW_TEMP_DONE            0x01
   59 #define OW_TEMP_RUNNING         0x02
   60 
   61 struct ow_temp_softc
   62 {
   63         device_t        dev;
   64         int             type;
   65         int             temp;
   66         int             flags;
   67         int             bad_crc;
   68         int             bad_reads;
   69         int             reading_interval;
   70         int             parasite;
   71         struct mtx      temp_lock;
   72         struct proc     *event_thread;
   73 };
   74 
   75 static int
   76 ow_temp_probe(device_t dev)
   77 {
   78 
   79         switch (ow_get_family(dev)) {
   80         case OWT_DS1820:
   81                 device_set_desc(dev, "One Wire Temperature");
   82                 return BUS_PROBE_DEFAULT;
   83         case OWT_DS1822:
   84         case OWT_DS1825:
   85         case OWT_DS18B20:
   86                 device_set_desc(dev, "Advanced One Wire Temperature");
   87                 return BUS_PROBE_DEFAULT;
   88         default:
   89                 return ENXIO;
   90         }
   91 }
   92 
   93 static int
   94 ow_temp_read_scratchpad(device_t dev, uint8_t *scratch, int len)
   95 {
   96         struct ow_cmd cmd;
   97 
   98         own_self_command(dev, &cmd, READ_SCRATCHPAD);
   99         cmd.xpt_read_len = len;
  100         own_command_wait(dev, &cmd);
  101         memcpy(scratch, cmd.xpt_read, len);
  102 
  103         return 0;
  104 }
  105 
  106 static int
  107 ow_temp_convert_t(device_t dev)
  108 {
  109         struct ow_cmd cmd;
  110 
  111         own_self_command(dev, &cmd, CONVERT_T);
  112         own_command_wait(dev, &cmd);
  113 
  114         return 0;
  115 }
  116 
  117 static int
  118 ow_temp_read_power_supply(device_t dev, int *parasite)
  119 {
  120         struct ow_cmd cmd;
  121 
  122         own_self_command(dev, &cmd, READ_POWER_SUPPLY);
  123         cmd.flags |= OW_FLAG_READ_BIT;
  124         cmd.xpt_read_len = 1;
  125         own_command_wait(dev, &cmd);
  126         *parasite = !cmd.xpt_read[0];   /* parasites pull bus low */
  127 
  128         return 0;
  129 }
  130 
  131 static void
  132 ow_temp_event_thread(void *arg)
  133 {
  134         struct ow_temp_softc *sc;
  135         uint8_t scratch[8 + 1];
  136         uint8_t crc;
  137         int retries, rv, tmp;
  138 
  139         sc = arg;
  140         pause("owtstart", device_get_unit(sc->dev) * hz / 100); // 10ms stagger
  141         mtx_lock(&sc->temp_lock);
  142         sc->flags |= OW_TEMP_RUNNING;
  143         mtx_unlock(&sc->temp_lock);
  144         ow_temp_read_power_supply(sc->dev, &sc->parasite);
  145         if (sc->parasite)
  146                 device_printf(sc->dev, "Running in parasitic mode unsupported\n");
  147         mtx_lock(&sc->temp_lock);
  148         while ((sc->flags & OW_TEMP_DONE) == 0) {
  149                 mtx_unlock(&sc->temp_lock);
  150                 ow_temp_convert_t(sc->dev);
  151                 mtx_lock(&sc->temp_lock);
  152                 msleep(sc, &sc->temp_lock, 0, "owtcvt", hz);
  153                 if (sc->flags & OW_TEMP_DONE)
  154                         break;
  155                 mtx_unlock(&sc->temp_lock);
  156                 for (retries = 5; retries > 0; retries--) {
  157                         rv = ow_temp_read_scratchpad(sc->dev, scratch, sizeof(scratch));
  158                         if (rv == 0) {
  159                                 crc = own_crc(sc->dev, scratch, sizeof(scratch) - 1);
  160                                 if (crc == scratch[8]) {
  161                                         if (sc->type == OWT_DS1820) {
  162                                                 if (scratch[7]) {
  163                                                         /*
  164                                                          * Formula from DS18S20 datasheet, page 6
  165                                                          * DS18S20 datasheet says count_per_c is 16, DS1820 does not
  166                                                          */
  167                                                         tmp = (int16_t)((scratch[0] & 0xfe) |
  168                                                             (scratch[1] << 8)) << 3;
  169                                                         tmp += 16 - scratch[6] - 4; /* count_per_c == 16 */
  170                                                 } else
  171                                                         tmp = (int16_t)(scratch[0] | (scratch[1] << 8)) << 3;
  172                                         } else
  173                                                 tmp = (int16_t)(scratch[0] | (scratch[1] << 8));
  174                                         sc->temp = tmp * 1000 / 16 + 273150;
  175                                         break;
  176                                 }
  177                                 sc->bad_crc++;
  178                         } else
  179                                 sc->bad_reads++;
  180                 }
  181                 mtx_lock(&sc->temp_lock);
  182                 msleep(sc, &sc->temp_lock, 0, "owtcvt", sc->reading_interval);
  183         }
  184         sc->flags &= ~OW_TEMP_RUNNING;
  185         mtx_unlock(&sc->temp_lock);
  186         kproc_exit(0);
  187 }
  188 
  189 static int
  190 ow_temp_attach(device_t dev)
  191 {
  192         struct ow_temp_softc *sc;
  193 
  194         sc = device_get_softc(dev);
  195         sc->dev = dev;
  196         sc->type = ow_get_family(dev);
  197         SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
  198             SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
  199             OID_AUTO, "temperature",
  200             CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_NEEDGIANT,
  201             &sc->temp, 0, sysctl_handle_int,
  202             "IK3", "Current Temperature");
  203         SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
  204             SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
  205             OID_AUTO, "badcrc", CTLFLAG_RD,
  206             &sc->bad_crc, 0,
  207             "Number of Bad CRC on reading scratchpad");
  208         SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
  209             SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
  210             OID_AUTO, "badread", CTLFLAG_RD,
  211             &sc->bad_reads, 0,
  212             "Number of errors on reading scratchpad");
  213         SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
  214             SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
  215             OID_AUTO, "reading_interval", CTLFLAG_RW,
  216             &sc->reading_interval, 0,
  217             "ticks between reads");
  218         SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
  219             SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
  220             OID_AUTO, "parasite", CTLFLAG_RW,
  221             &sc->parasite, 0,
  222             "In Parasite mode");
  223         /*
  224          * Just do this for unit 0 to avoid locking
  225          * the ow bus until that code can be put
  226          * into place.
  227          */
  228         sc->temp = -1;
  229         sc->reading_interval = 10 * hz;
  230         mtx_init(&sc->temp_lock, "lock for doing temperature", NULL, MTX_DEF);
  231         /* Start the thread */
  232         if (kproc_create(ow_temp_event_thread, sc, &sc->event_thread, 0, 0,
  233             "%s event thread", device_get_nameunit(dev))) {
  234                 device_printf(dev, "unable to create event thread.\n");
  235                 panic("ow_temp_attach, can't create thread");
  236         }
  237 
  238         return 0;
  239 }
  240 
  241 static int
  242 ow_temp_detach(device_t dev)
  243 {
  244         struct ow_temp_softc *sc;
  245 
  246         sc = device_get_softc(dev);
  247 
  248         /*
  249          * Wait for the thread to die.  kproc_exit will do a wakeup
  250          * on the event thread's struct thread * so that we know it is
  251          * safe to proceed.  IF the thread is running, set the please
  252          * die flag and wait for it to comply.  Since the wakeup on
  253          * the event thread happens only in kproc_exit, we don't
  254          * need to loop here.
  255          */
  256         mtx_lock(&sc->temp_lock);
  257         sc->flags |= OW_TEMP_DONE;
  258         while (sc->flags & OW_TEMP_RUNNING) {
  259                 wakeup(sc);
  260                 msleep(sc->event_thread, &sc->temp_lock, PWAIT, "owtun", 0);
  261         }
  262         mtx_destroy(&sc->temp_lock);
  263 
  264         return 0;
  265 }
  266 
  267 static device_method_t ow_temp_methods[] = {
  268         /* Device interface */
  269         DEVMETHOD(device_probe,         ow_temp_probe),
  270         DEVMETHOD(device_attach,        ow_temp_attach),
  271         DEVMETHOD(device_detach,        ow_temp_detach),
  272         { 0, 0 }
  273 };
  274 
  275 static driver_t ow_temp_driver = {
  276         "ow_temp",
  277         ow_temp_methods,
  278         sizeof(struct ow_temp_softc),
  279 };
  280 
  281 DRIVER_MODULE(ow_temp, ow, ow_temp_driver, 0, 0);
  282 MODULE_DEPEND(ow_temp, ow, 1, 1, 1);
Cache object: 437b2e6d4105291d3fdf168cd5a46e26
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FreeBSD/Linux Kernel Cross Reference sys/dev/ow/ow_temp.c

FreeBSD/Linux Kernel Cross Reference
sys/dev/ow/ow_temp.c
