1 /* $NetBSD: owtemp.c,v 1.15 2009/12/06 22:49:48 dyoung 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 1.15 2009/12/06 22:49:48 dyoung 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 void * sc_onewire; 44 u_int64_t sc_rom; 45 46 envsys_data_t sc_sensor; 47 struct sysmon_envsys *sc_sme; 48 49 uint32_t (*sc_owtemp_decode)(const uint8_t *); 50 51 int sc_dying; 52 }; 53 54 static int owtemp_match(device_t, cfdata_t, void *); 55 static void owtemp_attach(device_t, device_t, void *); 56 static int owtemp_detach(device_t, int); 57 static int owtemp_activate(device_t, enum devact); 58 59 static void owtemp_update(void *); 60 61 CFATTACH_DECL_NEW(owtemp, sizeof(struct owtemp_softc), 62 owtemp_match, owtemp_attach, owtemp_detach, owtemp_activate); 63 64 extern struct cfdriver owtemp_cd; 65 66 static const struct onewire_matchfam owtemp_fams[] = { 67 { ONEWIRE_FAMILY_DS1920 }, 68 { ONEWIRE_FAMILY_DS18B20 }, 69 { ONEWIRE_FAMILY_DS1822 }, 70 }; 71 72 static void owtemp_refresh(struct sysmon_envsys *, envsys_data_t *); 73 74 static uint32_t owtemp_decode_ds18b20(const uint8_t *); 75 static uint32_t owtemp_decode_ds1920(const uint8_t *); 76 77 static int 78 owtemp_match(device_t parent, cfdata_t match, void *aux) 79 { 80 return (onewire_matchbyfam(aux, owtemp_fams, 81 __arraycount(owtemp_fams))); 82 } 83 84 static void 85 owtemp_attach(device_t parent, device_t self, void *aux) 86 { 87 struct owtemp_softc *sc = device_private(self); 88 struct onewire_attach_args *oa = aux; 89 90 aprint_naive("\n"); 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(self), 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(self); 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(self, "unable to register with sysmon\n"); 123 sysmon_envsys_destroy(sc->sc_sme); 124 return; 125 } 126 127 aprint_normal("\n"); 128 } 129 130 static int 131 owtemp_detach(device_t 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 static int 141 owtemp_activate(device_t self, enum devact act) 142 { 143 struct owtemp_softc *sc = device_private(self); 144 145 switch (act) { 146 case DVACT_DEACTIVATE: 147 sc->sc_dying = 1; 148 return 0; 149 default: 150 return EOPNOTSUPP; 151 } 152 } 153 154 static void 155 owtemp_update(void *arg) 156 { 157 struct owtemp_softc *sc = arg; 158 u_int8_t data[9]; 159 160 onewire_lock(sc->sc_onewire); 161 if (onewire_reset(sc->sc_onewire) != 0) 162 goto done; 163 onewire_matchrom(sc->sc_onewire, sc->sc_rom); 164 165 /* 166 * Start temperature conversion. The conversion takes up to 750ms. 167 * After sending the command, the data line must be held high for 168 * at least 750ms to provide power during the conversion process. 169 * As such, no other activity may take place on the 1-Wire bus for 170 * at least this period. 171 */ 172 onewire_write_byte(sc->sc_onewire, DS_CMD_CONVERT); 173 tsleep(sc, PRIBIO, "owtemp", hz); 174 175 if (onewire_reset(sc->sc_onewire) != 0) 176 goto done; 177 onewire_matchrom(sc->sc_onewire, sc->sc_rom); 178 179 /* 180 * The result of the temperature measurement is placed in the 181 * first two bytes of the scratchpad. 182 */ 183 onewire_write_byte(sc->sc_onewire, DS_CMD_READ_SCRATCHPAD); 184 onewire_read_block(sc->sc_onewire, data, 9); 185 #if 0 186 if (onewire_crc(data, 8) == data[8]) { 187 sc->sc_sensor.value = 273150000 + 188 (int)((u_int16_t)data[1] << 8 | data[0]) * 500000; 189 } 190 #endif 191 192 sc->sc_sensor.value_cur = sc->sc_owtemp_decode(data); 193 sc->sc_sensor.state = ENVSYS_SVALID; 194 195 done: 196 onewire_unlock(sc->sc_onewire); 197 } 198 199 static void 200 owtemp_refresh(struct sysmon_envsys *sme, envsys_data_t *edata) 201 { 202 struct owtemp_softc *sc = sme->sme_cookie; 203 204 owtemp_update(sc); 205 } 206 207 static uint32_t 208 owtemp_decode_ds18b20(const uint8_t *buf) 209 { 210 int temp; 211 212 /* 213 * Sign-extend the MSB byte, and add in the fractions of a 214 * degree contained in the LSB (precision 1/16th DegC). 215 */ 216 temp = (int8_t)buf[1]; 217 temp = (temp << 8) | buf[0]; 218 219 /* 220 * Conversion to uK is simple. 221 */ 222 return (temp * 62500 + 273150000); 223 } 224 225 static uint32_t 226 owtemp_decode_ds1920(const uint8_t *buf) 227 { 228 int temp; 229 230 /* 231 * Sign-extend the MSB byte, and add in the fractions of a 232 * degree contained in the LSB (precision 1/2 DegC). 233 */ 234 temp = (int8_t)buf[1]; 235 temp = (temp << 8) | buf[0]; 236 237 /* Convert to uK */ 238 return (temp * 500000 + 273150000); 239 } 240