Annotation of sys/dev/onewire/owsbm.c, Revision 1.1
1.1 ! nbrk 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: }
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