sys/dev/ow/ow_temp.c

   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 devclass_t ow_temp_devclass;
 268
 269 static device_method_t ow_temp_methods[] = {
 270         /* Device interface */
 271         DEVMETHOD(device_probe,         ow_temp_probe),
 272         DEVMETHOD(device_attach,        ow_temp_attach),
 273         DEVMETHOD(device_detach,        ow_temp_detach),
 274         { 0, 0 }
 275 };
 276
 277 static driver_t ow_temp_driver = {
 278         "ow_temp",
 279         ow_temp_methods,
 280         sizeof(struct ow_temp_softc),
 281 };
 282
 283 DRIVER_MODULE(ow_temp, ow, ow_temp_driver, ow_temp_devclass, 0, 0);
 284 MODULE_DEPEND(ow_temp, ow, 1, 1, 1);