root/dev/onewire/owsbm.c

/* [<][>][^][v][top][bottom][index][help] */

DEFINITIONS

This source file includes following definitions.
  1. owsbm_match
  2. owsbm_attach
  3. owsbm_detach
  4. owsbm_activate
  5. owsbm_update

    1 /*      $OpenBSD: owsbm.c,v 1.4 2007/06/24 05:34:35 dlg Exp $   */
    2 
    3 /*
    4  * Copyright (c) 2007 Aaron Linville <aaron@linville.org>
    5  *
    6  * Permission to use, copy, modify, and distribute this software for any
    7  * purpose with or without fee is hereby granted, provided that the above
    8  * copyright notice and this permission notice appear in all copies.
    9  *
   10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
   13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   17  */
   18 
   19 /*
   20  * 1-Wire Smart Battery Monitor family type device driver.
   21  * Provides on-board temperature, an A/D converter for voltage/current,
   22  * current accumulator, elapsed time metter, and 40 bytes of nonvolatile
   23  * memory.
   24  */
   25 
   26 #include <sys/param.h>
   27 #include <sys/systm.h>
   28 #include <sys/device.h>
   29 #include <sys/kernel.h>
   30 #include <sys/proc.h>
   31 #include <sys/rwlock.h>
   32 #include <sys/sensors.h>
   33 
   34 #include <dev/onewire/onewiredevs.h>
   35 #include <dev/onewire/onewirereg.h>
   36 #include <dev/onewire/onewirevar.h>
   37 
   38 /* Commands */
   39 #define DSSBM_CMD_READ_SCRATCHPAD       0xbe
   40 #define DSSBM_CMD_WRITE_SCRATCHPAD      0x4e
   41 #define DSSBM_CMD_COPY_SCRATCHPAD       0x48
   42 
   43 #define DSSBM_CMD_RECALL_MEMORY         0xb8
   44 
   45 #define DSSBM_CMD_CONVERT_T             0x44
   46 #define DSSBM_CMD_CONVERT_V             0xb4    
   47 
   48 /* Scratchpad layout */
   49 #define DS2438_SP_STATUS                0
   50 #define DS2438_SP_TEMP_LSB              1
   51 #define DS2438_SP_TEMP_MSB              2
   52 #define DS2438_SP_VOLT_LSB              3
   53 #define DS2438_SP_VOLT_MSB              4
   54 #define DS2438_SP_CURRENT_LSB           5
   55 #define DS2438_SP_CURRENT_MSB           6
   56 #define DS2438_SP_THRESHOLD             7
   57 #define DS2438_SP_CRC                   8
   58 
   59 struct owsbm_softc {
   60         struct device           sc_dev;
   61 
   62         void *                  sc_onewire;
   63         u_int64_t               sc_rom;
   64 
   65         struct ksensordev       sc_sensordev;
   66 
   67         struct ksensor          sc_temp;
   68         struct ksensor          sc_voltage_vdd; /* Battery, AD = 1*/
   69         struct ksensor          sc_voltage_vad; /* General purpose, AD = 0 */
   70         struct ksensor          sc_voltage_cr; /* Current Register */
   71 
   72         struct sensor_task      *sc_sensortask;
   73 
   74         struct rwlock           sc_lock;
   75 };
   76 
   77 int     owsbm_match(struct device *, void *, void *);
   78 void    owsbm_attach(struct device *, struct device *, void *);
   79 int     owsbm_detach(struct device *, int);
   80 int     owsbm_activate(struct device *, enum devact);
   81 
   82 void    owsbm_update(void *);
   83 
   84 struct cfattach owsbm_ca = {
   85         sizeof(struct owsbm_softc),
   86         owsbm_match,
   87         owsbm_attach,
   88         owsbm_detach,
   89         owsbm_activate
   90 };
   91 
   92 struct cfdriver owsbm_cd = {
   93         NULL, "owsbm", DV_DULL
   94 };
   95 
   96 static const struct onewire_matchfam owsbm_fams[] = {
   97         { ONEWIRE_FAMILY_DS2438 }
   98 };
   99 
  100 int
  101 owsbm_match(struct device *parent, void *match, void *aux)
  102 {
  103         return (onewire_matchbyfam(aux, owsbm_fams,
  104             sizeof(owsbm_fams) /sizeof(owsbm_fams[0])));
  105 }
  106 
  107 void
  108 owsbm_attach(struct device *parent, struct device *self, void *aux)
  109 {
  110         struct owsbm_softc *sc = (struct owsbm_softc *)self;
  111         struct onewire_attach_args *oa = aux;
  112 
  113         sc->sc_onewire = oa->oa_onewire;
  114         sc->sc_rom = oa->oa_rom;
  115 
  116         /* Initialize temp sensor */
  117         strlcpy(sc->sc_sensordev.xname, sc->sc_dev.dv_xname,
  118             sizeof(sc->sc_sensordev.xname));
  119         sc->sc_temp.type = SENSOR_TEMP;
  120         sensor_attach(&sc->sc_sensordev, &sc->sc_temp);
  121 
  122         /* Initialize voltage sensor */
  123         sc->sc_voltage_vdd.type = SENSOR_VOLTS_DC;
  124         strlcpy(sc->sc_voltage_vdd.desc, "VDD", sizeof(sc->sc_voltage_vdd.desc));
  125         sensor_attach(&sc->sc_sensordev, &sc->sc_voltage_vdd);
  126 
  127         /* Initialize voltage sensor */
  128         sc->sc_voltage_vad.type = SENSOR_VOLTS_DC;
  129         strlcpy(sc->sc_voltage_vad.desc, "VAD", sizeof(sc->sc_voltage_vad.desc));
  130         sensor_attach(&sc->sc_sensordev, &sc->sc_voltage_vad);
  131 
  132         /* Initialize the current sensor */
  133         sc->sc_voltage_cr.type = SENSOR_VOLTS_DC;
  134         strlcpy(sc->sc_voltage_cr.desc, "CR", sizeof(sc->sc_voltage_cr.desc));
  135         sensor_attach(&sc->sc_sensordev, &sc->sc_voltage_cr);
  136 
  137         sc->sc_sensortask = sensor_task_register(sc, owsbm_update, 10);
  138         if (sc->sc_sensortask == NULL) {
  139                 printf(": unable to register owsbm update task\n");
  140                 return;
  141         }
  142 
  143         sensordev_install(&sc->sc_sensordev);
  144 
  145         rw_init(&sc->sc_lock, sc->sc_dev.dv_xname);
  146         printf("\n");
  147 }
  148 
  149 int
  150 owsbm_detach(struct device *self, int flags)
  151 {
  152         struct owsbm_softc *sc = (struct owsbm_softc *)self;
  153 
  154         rw_enter_write(&sc->sc_lock);
  155         sensordev_deinstall(&sc->sc_sensordev);
  156         if (sc->sc_sensortask != NULL)
  157                 sensor_task_unregister(sc->sc_sensortask);
  158         rw_exit_write(&sc->sc_lock);
  159 
  160         return (0);
  161 }
  162 
  163 int
  164 owsbm_activate(struct device *self, enum devact act)
  165 {
  166         return (0);
  167 }
  168 
  169 void
  170 owsbm_update(void *arg)
  171 {
  172         struct owsbm_softc *sc = arg;
  173         u_int8_t data[9];
  174 
  175         rw_enter_write(&sc->sc_lock);
  176         onewire_lock(sc->sc_onewire, 0);
  177         if (onewire_reset(sc->sc_onewire) != 0)
  178                 goto done;
  179 
  180         onewire_matchrom(sc->sc_onewire, sc->sc_rom);
  181         onewire_write_byte(sc->sc_onewire, DSSBM_CMD_CONVERT_T);
  182         if (onewire_reset(sc->sc_onewire) != 0)
  183                 goto done;
  184         
  185         onewire_matchrom(sc->sc_onewire, sc->sc_rom);
  186         onewire_write_byte(sc->sc_onewire, DSSBM_CMD_CONVERT_V);
  187         if (onewire_reset(sc->sc_onewire) != 0)
  188                 goto done;
  189 
  190         onewire_matchrom(sc->sc_onewire, sc->sc_rom);
  191         /* Issue Recall Memory page 00h cmd */
  192         onewire_write_byte(sc->sc_onewire, DSSBM_CMD_RECALL_MEMORY);
  193         onewire_write_byte(sc->sc_onewire, 0);
  194 
  195         if (onewire_reset(sc->sc_onewire) != 0)
  196                 goto done;
  197 
  198         onewire_matchrom(sc->sc_onewire, sc->sc_rom);
  199         /* Read page 0 of Memory Map from Scratchpad */
  200         onewire_write_byte(sc->sc_onewire, DSSBM_CMD_READ_SCRATCHPAD);
  201         onewire_write_byte(sc->sc_onewire, 0);
  202         onewire_read_block(sc->sc_onewire, data, 9);
  203         if (onewire_crc(data, 8) == data[DS2438_SP_CRC]) {
  204                 sc->sc_temp.value = 273150000 +
  205                      (int)(((u_int16_t)data[DS2438_SP_TEMP_MSB] << 5) |
  206                      ((u_int16_t)data[DS2438_SP_TEMP_LSB] >> 3)) * 31250;
  207                 sc->sc_voltage_vdd.value =
  208                      (int)(((u_int16_t)data[DS2438_SP_VOLT_MSB] << 8) |
  209                      data[DS2438_SP_VOLT_LSB]) * 10000;
  210 
  211                 sc->sc_voltage_cr.value =
  212                     (int)(((u_int16_t)data[DS2438_SP_CURRENT_MSB] << 8) |
  213                     data[DS2438_SP_CURRENT_LSB]) * 244;
  214         }
  215 
  216         /* Reconfigure DS2438 to measure VAD */
  217 
  218         if (onewire_reset(sc->sc_onewire) != 0)
  219                 goto done;
  220 
  221         onewire_matchrom(sc->sc_onewire, sc->sc_rom);
  222         onewire_write_byte(sc->sc_onewire, DSSBM_CMD_WRITE_SCRATCHPAD);
  223         onewire_write_byte(sc->sc_onewire, 0);
  224         onewire_write_byte(sc->sc_onewire, 0x7); /* AD = 0 */
  225 
  226         if (onewire_reset(sc->sc_onewire) != 0)
  227                 goto done;
  228 
  229         onewire_matchrom(sc->sc_onewire, sc->sc_rom);
  230         onewire_write_byte(sc->sc_onewire, DSSBM_CMD_CONVERT_V);
  231         if (onewire_reset(sc->sc_onewire) != 0)
  232                 goto done;
  233 
  234         onewire_matchrom(sc->sc_onewire, sc->sc_rom);
  235         /* Issue Recall Memory page 00h cmd */
  236         onewire_write_byte(sc->sc_onewire, DSSBM_CMD_RECALL_MEMORY);
  237         onewire_write_byte(sc->sc_onewire, 0);
  238 
  239         if (onewire_reset(sc->sc_onewire) != 0)
  240                 goto done;
  241 
  242         onewire_matchrom(sc->sc_onewire, sc->sc_rom);
  243         onewire_write_byte(sc->sc_onewire, DSSBM_CMD_READ_SCRATCHPAD);
  244         onewire_write_byte(sc->sc_onewire, 0);
  245         onewire_read_block(sc->sc_onewire, data, 9);
  246         if (onewire_crc(data, 8) == data[8]) {
  247                 sc->sc_voltage_vad.value =
  248                     (int)(((u_int16_t)data[DS2438_SP_VOLT_MSB] << 8) |
  249                     data[DS2438_SP_VOLT_LSB]) * 10000;
  250         }
  251 
  252         /* Reconfigure back DS2438 to measure VDD (default) */
  253 
  254         if (onewire_reset(sc->sc_onewire) != 0)
  255                 goto done;
  256 
  257         onewire_matchrom(sc->sc_onewire, sc->sc_rom);
  258         onewire_write_byte(sc->sc_onewire, DSSBM_CMD_WRITE_SCRATCHPAD);
  259         onewire_write_byte(sc->sc_onewire, 0);
  260         onewire_write_byte(sc->sc_onewire, 0xf); /* AD = 1 */
  261         onewire_reset(sc->sc_onewire);
  262 
  263 done:
  264         onewire_unlock(sc->sc_onewire);
  265         rw_exit_write(&sc->sc_lock);
  266 }

/* [<][>][^][v][top][bottom][index][help] */