1 /* $NetBSD: owtemp.c,v 1.13 2008/04/08 20:14:02 cegger Exp $ */ 2 /* $OpenBSD: owtemp.c,v 1.1 2006/03/04 16:27:03 grange Exp $ */ 3 4 /* 5 * Copyright (c) 2006 Alexander Yurchenko <grange@openbsd.org> 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 /* 21 * 1-Wire temperature family type device driver. 22 */ 23 24 #include <sys/cdefs.h> 25 __KERNEL_RCSID(0, "$NetBSD: owtemp.c,v 1.13 2008/04/08 20:14:02 cegger Exp $"); 26 27 #include <sys/param.h> 28 #include <sys/systm.h> 29 #include <sys/device.h> 30 #include <sys/kernel.h> 31 #include <sys/proc.h> 32 33 #include <dev/sysmon/sysmonvar.h> 34 35 #include <dev/onewire/onewiredevs.h> 36 #include <dev/onewire/onewirereg.h> 37 #include <dev/onewire/onewirevar.h> 38 39 #define DS_CMD_CONVERT 0x44 40 #define DS_CMD_READ_SCRATCHPAD 0xbe 41 42 struct owtemp_softc { 43 struct device sc_dev; 44 45 void * sc_onewire; 46 u_int64_t sc_rom; 47 48 envsys_data_t sc_sensor; 49 struct sysmon_envsys *sc_sme; 50 51 uint32_t (*sc_owtemp_decode)(const uint8_t *); 52 53 int sc_dying; 54 }; 55 56 int owtemp_match(struct device *, struct cfdata *, void *); 57 void owtemp_attach(struct device *, struct device *, void *); 58 int owtemp_detach(struct device *, int); 59 int owtemp_activate(struct device *, enum devact); 60 61 void owtemp_update(void *); 62 63 CFATTACH_DECL(owtemp, sizeof(struct owtemp_softc), 64 owtemp_match, owtemp_attach, owtemp_detach, owtemp_activate); 65 66 extern struct cfdriver owtemp_cd; 67 68 static const struct onewire_matchfam owtemp_fams[] = { 69 { ONEWIRE_FAMILY_DS1920 }, 70 { ONEWIRE_FAMILY_DS18B20 }, 71 { ONEWIRE_FAMILY_DS1822 }, 72 }; 73 74 static void owtemp_refresh(struct sysmon_envsys *, envsys_data_t *); 75 76 static uint32_t owtemp_decode_ds18b20(const uint8_t *); 77 static uint32_t owtemp_decode_ds1920(const uint8_t *); 78 79 int 80 owtemp_match(struct device *parent, struct cfdata *cf, void *aux) 81 { 82 return (onewire_matchbyfam(aux, owtemp_fams, 83 __arraycount(owtemp_fams))); 84 } 85 86 void 87 owtemp_attach(struct device *parent, struct device *self, void *aux) 88 { 89 struct owtemp_softc *sc = device_private(self); 90 struct onewire_attach_args *oa = aux; 91 92 sc->sc_onewire = oa->oa_onewire; 93 sc->sc_rom = oa->oa_rom; 94 95 switch(ONEWIRE_ROM_FAMILY_TYPE(sc->sc_rom)) { 96 case ONEWIRE_FAMILY_DS18B20: 97 case ONEWIRE_FAMILY_DS1822: 98 sc->sc_owtemp_decode = owtemp_decode_ds18b20; 99 break; 100 case ONEWIRE_FAMILY_DS1920: 101 sc->sc_owtemp_decode = owtemp_decode_ds1920; 102 break; 103 } 104 105 sc->sc_sme = sysmon_envsys_create(); 106 107 /* Initialize sensor */ 108 sc->sc_sensor.units = ENVSYS_STEMP; 109 (void)strlcpy(sc->sc_sensor.desc, 110 device_xname(&sc->sc_dev), sizeof(sc->sc_sensor.desc)); 111 if (sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor)) { 112 sysmon_envsys_destroy(sc->sc_sme); 113 return; 114 } 115 116 /* Hook into system monitor. */ 117 sc->sc_sme->sme_name = device_xname(&sc->sc_dev); 118 sc->sc_sme->sme_cookie = sc; 119 sc->sc_sme->sme_refresh = owtemp_refresh; 120 121 if (sysmon_envsys_register(sc->sc_sme)) { 122 aprint_error_dev(&sc->sc_dev, "unable to register with sysmon\n"); 123 sysmon_envsys_destroy(sc->sc_sme); 124 return; 125 } 126 127 printf("\n"); 128 } 129 130 int 131 owtemp_detach(struct device *self, int flags) 132 { 133 struct owtemp_softc *sc = device_private(self); 134 135 sysmon_envsys_unregister(sc->sc_sme); 136 137 return 0; 138 } 139 140 int 141 owtemp_activate(struct device *self, enum devact act) 142 { 143 struct owtemp_softc *sc = device_private(self); 144 145 switch (act) { 146 case DVACT_ACTIVATE: 147 return (EOPNOTSUPP); 148 case DVACT_DEACTIVATE: 149 sc->sc_dying = 1; 150 break; 151 } 152 153 return (0); 154 } 155 156 void 157 owtemp_update(void *arg) 158 { 159 struct owtemp_softc *sc = arg; 160 u_int8_t data[9]; 161 162 onewire_lock(sc->sc_onewire); 163 if (onewire_reset(sc->sc_onewire) != 0) 164 goto done; 165 onewire_matchrom(sc->sc_onewire, sc->sc_rom); 166 167 /* 168 * Start temperature conversion. The conversion takes up to 750ms. 169 * After sending the command, the data line must be held high for 170 * at least 750ms to provide power during the conversion process. 171 * As such, no other activity may take place on the 1-Wire bus for 172 * at least this period. 173 */ 174 onewire_write_byte(sc->sc_onewire, DS_CMD_CONVERT); 175 tsleep(sc, PRIBIO, "owtemp", hz); 176 177 if (onewire_reset(sc->sc_onewire) != 0) 178 goto done; 179 onewire_matchrom(sc->sc_onewire, sc->sc_rom); 180 181 /* 182 * The result of the temperature measurement is placed in the 183 * first two bytes of the scratchpad. 184 */ 185 onewire_write_byte(sc->sc_onewire, DS_CMD_READ_SCRATCHPAD); 186 onewire_read_block(sc->sc_onewire, data, 9); 187 #if 0 188 if (onewire_crc(data, 8) == data[8]) { 189 sc->sc_sensor.value = 273150000 + 190 (int)((u_int16_t)data[1] << 8 | data[0]) * 500000; 191 } 192 #endif 193 194 sc->sc_sensor.value_cur = sc->sc_owtemp_decode(data); 195 sc->sc_sensor.state = ENVSYS_SVALID; 196 197 done: 198 onewire_unlock(sc->sc_onewire); 199 } 200 201 static void 202 owtemp_refresh(struct sysmon_envsys *sme, envsys_data_t *edata) 203 { 204 struct owtemp_softc *sc = sme->sme_cookie; 205 206 owtemp_update(sc); 207 } 208 209 static uint32_t 210 owtemp_decode_ds18b20(const uint8_t *buf) 211 { 212 int temp; 213 214 /* 215 * Sign-extend the MSB byte, and add in the fractions of a 216 * degree contained in the LSB (precision 1/16th DegC). 217 */ 218 temp = (int8_t)buf[1]; 219 temp = (temp << 8) | buf[0]; 220 221 /* 222 * Conversion to uK is simple. 223 */ 224 return (temp * 62500 + 273150000); 225 } 226 227 static uint32_t 228 owtemp_decode_ds1920(const uint8_t *buf) 229 { 230 int temp; 231 232 /* 233 * Sign-extend the MSB byte, and add in the fractions of a 234 * degree contained in the LSB (precision 1/2 DegC). 235 */ 236 temp = (int8_t)buf[1]; 237 temp = (temp << 8) | buf[0]; 238 239 /* Convert to uK */ 240 return (temp * 500000 + 273150000); 241 } 242