sys/dev/ow/ow_temp.c

   1 /*-
   2  * Copyright (c) 2015 M. Warner Losh <imp@freebsd.org>
   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 unmodified, this list of conditions, and the following
  10  *    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 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD$");
  29
  30 #include <sys/param.h>
  31 #include <sys/systm.h>
  32 #include <sys/kernel.h>
  33
  34 #include <sys/bus.h>
  35 #include <sys/errno.h>
  36 #include <sys/libkern.h>
  37 #include <sys/kthread.h>
  38 #include <sys/malloc.h>
  39 #include <sys/module.h>
  40 #include <sys/mutex.h>
  41 #include <sys/proc.h>
  42 #include <sys/sysctl.h>
  43
  44 #include <dev/ow/ow.h>
  45 #include <dev/ow/own.h>
  46
  47 #define OWT_DS1820      0x10            /* Also 18S20 */
  48 #define OWT_DS1822      0x22            /* Very close to 18B20 */
  49 #define OWT_DS18B20     0x28            /* Also MAX31820 */
  50 #define OWT_DS1825      0x3B            /* Just like 18B20 with address bits */
  51
  52 #define CONVERT_T               0x44
  53 #define COPY_SCRATCHPAD         0x48
  54 #define WRITE_SCRATCHPAD        0x4e
  55 #define READ_POWER_SUPPLY       0xb4
  56 #define RECALL_EE               0xb8
  57 #define READ_SCRATCHPAD         0xbe
  58
  59
  60 #define OW_TEMP_DONE            0x01
  61 #define OW_TEMP_RUNNING         0x02
  62
  63 struct ow_temp_softc
  64 {
  65         device_t        dev;
  66         int             type;
  67         int             temp;
  68         int             flags;
  69         int             bad_crc;
  70         int             bad_reads;
  71         int             reading_interval;
  72         int             parasite;
  73         struct mtx      temp_lock;
  74         struct proc     *event_thread;
  75 };
  76
  77 static int
  78 ow_temp_probe(device_t dev)
  79 {
  80
  81         switch (ow_get_family(dev)) {
  82         case OWT_DS1820:
  83                 device_set_desc(dev, "One Wire Temperature");
  84                 return BUS_PROBE_DEFAULT;
  85         case OWT_DS1822:
  86         case OWT_DS1825:
  87         case OWT_DS18B20:
  88                 device_set_desc(dev, "Advanced One Wire Temperature");
  89                 return BUS_PROBE_DEFAULT;
  90         default:
  91                 return ENXIO;
  92         }
  93 }
  94
  95 static int
  96 ow_temp_read_scratchpad(device_t dev, uint8_t *scratch, int len)
  97 {
  98         struct ow_cmd cmd;
  99
 100         own_self_command(dev, &cmd, READ_SCRATCHPAD);
 101         cmd.xpt_read_len = len;
 102         own_command_wait(dev, &cmd);
 103         memcpy(scratch, cmd.xpt_read, len);
 104
 105         return 0;
 106 }
 107
 108 static int
 109 ow_temp_convert_t(device_t dev)
 110 {
 111         struct ow_cmd cmd;
 112
 113         own_self_command(dev, &cmd, CONVERT_T);
 114         own_command_wait(dev, &cmd);
 115
 116         return 0;
 117 }
 118
 119
 120 static int
 121 ow_temp_read_power_supply(device_t dev, int *parasite)
 122 {
 123         struct ow_cmd cmd;
 124
 125         own_self_command(dev, &cmd, READ_POWER_SUPPLY);
 126         cmd.flags |= OW_FLAG_READ_BIT;
 127         cmd.xpt_read_len = 1;
 128         own_command_wait(dev, &cmd);
 129         *parasite = !cmd.xpt_read[0];   /* parasites pull bus low */
 130
 131         return 0;
 132 }
 133
 134 static void
 135 ow_temp_event_thread(void *arg)
 136 {
 137         struct ow_temp_softc *sc;
 138         uint8_t scratch[8 + 1];
 139         uint8_t crc;
 140         int retries, rv, tmp;
 141
 142         sc = arg;
 143         pause("owtstart", device_get_unit(sc->dev) * hz / 100); // 10ms stagger
 144         mtx_lock(&sc->temp_lock);
 145         sc->flags |= OW_TEMP_RUNNING;
 146         mtx_unlock(&sc->temp_lock);
 147         ow_temp_read_power_supply(sc->dev, &sc->parasite);
 148         if (sc->parasite)
 149                 device_printf(sc->dev, "Running in parasitic mode unsupported\n");
 150         mtx_lock(&sc->temp_lock);
 151         while ((sc->flags & OW_TEMP_DONE) == 0) {
 152                 mtx_unlock(&sc->temp_lock);
 153                 ow_temp_convert_t(sc->dev);
 154                 mtx_lock(&sc->temp_lock);
 155                 msleep(sc, &sc->temp_lock, 0, "owtcvt", hz);
 156                 if (sc->flags & OW_TEMP_DONE)
 157                         break;
 158                 mtx_unlock(&sc->temp_lock);
 159                 for (retries = 5; retries > 0; retries--) {
 160                         rv = ow_temp_read_scratchpad(sc->dev, scratch, sizeof(scratch));
 161                         if (rv == 0) {
 162                                 crc = own_crc(sc->dev, scratch, sizeof(scratch) - 1);
 163                                 if (crc == scratch[8]) {
 164                                         if (sc->type == OWT_DS1820) {
 165                                                 if (scratch[7]) {
 166                                                         /*
 167                                                          * Formula from DS18S20 datasheet, page 6
 168                                                          * DS18S20 datasheet says count_per_c is 16, DS1820 does not
 169                                                          */
 170                                                         tmp = (int16_t)((scratch[0] & 0xfe) |
 171                                                             (scratch[1] << 8)) << 3;
 172                                                         tmp += 16 - scratch[6] - 4; /* count_per_c == 16 */
 173                                                 } else
 174                                                         tmp = (int16_t)(scratch[0] | (scratch[1] << 8)) << 3;
 175                                         } else
 176                                                 tmp = (int16_t)(scratch[0] | (scratch[1] << 8));
 177                                         sc->temp = tmp * 1000 / 16 + 273150;
 178                                         break;
 179                                 }
 180                                 sc->bad_crc++;
 181                         } else
 182                                 sc->bad_reads++;
 183                 }
 184                 mtx_lock(&sc->temp_lock);
 185                 msleep(sc, &sc->temp_lock, 0, "owtcvt", sc->reading_interval);
 186         }
 187         sc->flags &= ~OW_TEMP_RUNNING;
 188         mtx_unlock(&sc->temp_lock);
 189         kproc_exit(0);
 190 }
 191
 192 static int
 193 ow_temp_attach(device_t dev)
 194 {
 195         struct ow_temp_softc *sc;
 196
 197         sc = device_get_softc(dev);
 198         sc->dev = dev;
 199         sc->type = ow_get_family(dev);
 200         SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
 201             SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
 202             OID_AUTO, "temperature", CTLFLAG_RD | CTLTYPE_INT,
 203             &sc->temp, 0, sysctl_handle_int,
 204             "IK3", "Current Temperature");
 205         SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
 206             SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
 207             OID_AUTO, "badcrc", CTLFLAG_RD,
 208             &sc->bad_crc, 0,
 209             "Number of Bad CRC on reading scratchpad");
 210         SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
 211             SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
 212             OID_AUTO, "badread", CTLFLAG_RD,
 213             &sc->bad_reads, 0,
 214             "Number of errors on reading scratchpad");
 215         SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
 216             SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
 217             OID_AUTO, "reading_interval", CTLFLAG_RW,
 218             &sc->reading_interval, 0,
 219             "ticks between reads");
 220         SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
 221             SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
 222             OID_AUTO, "parasite", CTLFLAG_RW,
 223             &sc->parasite, 0,
 224             "In Parasite mode");
 225         /*
 226          * Just do this for unit 0 to avoid locking
 227          * the ow bus until that code can be put
 228          * into place.
 229          */
 230         sc->temp = -1;
 231         sc->reading_interval = 10 * hz;
 232         mtx_init(&sc->temp_lock, "lock for doing temperature", NULL, MTX_DEF);
 233         /* Start the thread */
 234         if (kproc_create(ow_temp_event_thread, sc, &sc->event_thread, 0, 0,
 235             "%s event thread", device_get_nameunit(dev))) {
 236                 device_printf(dev, "unable to create event thread.\n");
 237                 panic("ow_temp_attach, can't create thread");
 238         }
 239
 240         return 0;
 241 }
 242
 243 static int
 244 ow_temp_detach(device_t dev)
 245 {
 246         struct ow_temp_softc *sc;
 247
 248         sc = device_get_softc(dev);
 249
 250         /*
 251          * Wait for the thread to die.  kproc_exit will do a wakeup
 252          * on the event thread's struct thread * so that we know it is
 253          * safe to proceed.  IF the thread is running, set the please
 254          * die flag and wait for it to comply.  Since the wakeup on
 255          * the event thread happens only in kproc_exit, we don't
 256          * need to loop here.
 257          */
 258         mtx_lock(&sc->temp_lock);
 259         sc->flags |= OW_TEMP_DONE;
 260         while (sc->flags & OW_TEMP_RUNNING) {
 261                 wakeup(sc);
 262                 msleep(sc->event_thread, &sc->temp_lock, PWAIT, "owtun", 0);
 263         }
 264         mtx_destroy(&sc->temp_lock);
 265
 266         return 0;
 267 }
 268
 269 devclass_t ow_temp_devclass;
 270
 271 static device_method_t ow_temp_methods[] = {
 272         /* Device interface */
 273         DEVMETHOD(device_probe,         ow_temp_probe),
 274         DEVMETHOD(device_attach,        ow_temp_attach),
 275         DEVMETHOD(device_detach,        ow_temp_detach),
 276
 277         { 0, 0 }
 278 };
 279
 280 static driver_t ow_temp_driver = {
 281         "ow_temp",
 282         ow_temp_methods,
 283         sizeof(struct ow_temp_softc),
 284 };
 285
 286 DRIVER_MODULE(ow_temp, ow, ow_temp_driver, ow_temp_devclass, 0, 0);
 287 MODULE_DEPEND(ow_temp, ow, 1, 1, 1);