/* $OpenBSD: lm75.c,v 1.12 2006/04/10 00:57:23 deraadt Exp $ */ /* $NetBSD: lm75.c,v 1.1 2003/09/30 00:35:31 thorpej Exp $ */ /* * Copyright (c) 2006 Theo de Raadt * Copyright (c) 2004 Alexander Yurchenko * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* * National Semiconductor LM75/LM77 temperature sensor. */ #include #include #include #include #include #include #define LM_MODEL_LM75 1 #define LM_MODEL_LM77 2 #define LM_MODEL_DS1775 3 #define LM_POLLTIME 3 /* 3s */ #define LM75_REG_TEMP 0x00 #define LM75_REG_CONFIG 0x01 #define LM75_CONFIG_SHUTDOWN 0x01 #define LM75_CONFIG_CMPINT 0x02 #define LM75_CONFIG_OSPOLARITY 0x04 #define LM75_CONFIG_FAULT_QUEUE_MASK 0x18 #define LM75_CONFIG_FAULT_QUEUE_1 (0 << 3) #define LM75_CONFIG_FAULT_QUEUE_2 (1 << 3) #define LM75_CONFIG_FAULT_QUEUE_4 (2 << 3) #define LM75_CONFIG_FAULT_QUEUE_6 (3 << 3) #define LM77_CONFIG_INTPOLARITY 0x08 #define LM77_CONFIG_FAULT_QUEUE_4 0x10 #define DS1755_CONFIG_RESOLUTION(i) (9 + (((i) >> 5) & 3)) #define LM75_REG_THYST_SET_POINT 0x02 #define LM75_REG_TOS_SET_POINT 0x03 #define LM77_REG_TLOW 0x04 #define LM77_REG_THIGH 0x05 struct lmtemp_softc { struct device sc_dev; i2c_tag_t sc_tag; int sc_addr; int sc_model; int sc_bits; struct sensor sc_sensor; }; int lmtemp_match(struct device *, void *, void *); void lmtemp_attach(struct device *, struct device *, void *); struct cfattach lmtemp_ca = { sizeof(struct lmtemp_softc), lmtemp_match, lmtemp_attach }; struct cfdriver lmtemp_cd = { NULL, "lmtemp", DV_DULL }; /* * Temperature on the LM75 is represented by a 9-bit two's complement * integer in steps of 0.5C. The following examples are taken from * the LM75 data sheet: * * +125C 0 1111 1010 0x0fa * +25C 0 0011 0010 0x032 * +0.5C 0 0000 0001 0x001 * 0C 0 0000 0000 0x000 * -0.5C 1 1111 1111 0x1ff * -25C 1 1100 1110 0x1ce * -55C 1 1001 0010 0x192 * * Temperature on the LM77 is represented by a 10-bit two's complement * integer in steps of 0.5C: * * +130C 01 0000 0100 0x104 * +125C 00 1111 1010 0x0fa * +25C 00 0011 0010 0x032 * +0.5C 00 0000 0001 0x001 * 0C 00 0000 0000 0x000 * -0.5C 11 1111 1111 0x3ff * -25C 11 1100 1110 0x3ce * -55C 11 1001 0010 0x392 * * LM75 temperature word: * * MSB Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 X X X X X X X * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 * * * LM77 temperature word: * * Sign Sign Sign Sign MSB Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 Status bits * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 */ int lmtemp_temp_read(struct lmtemp_softc *, uint8_t, int *); void lmtemp_refresh_sensor_data(void *); int lmtemp_match(struct device *parent, void *match, void *aux) { struct i2c_attach_args *ia = aux; if (strcmp(ia->ia_name, "lm75") == 0 || strcmp(ia->ia_name, "lm77") == 0 || strcmp(ia->ia_name, "ds1775") == 0) return (1); return (0); } void lmtemp_attach(struct device *parent, struct device *self, void *aux) { struct lmtemp_softc *sc = (struct lmtemp_softc *)self; struct i2c_attach_args *ia = aux; u_int8_t cmd, data; sc->sc_tag = ia->ia_tag; sc->sc_addr = ia->ia_addr; printf(": %s", ia->ia_name); /* If in SHUTDOWN mode, wake it up */ iic_acquire_bus(sc->sc_tag, 0); cmd = LM75_REG_CONFIG; if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr, &cmd, 1, &data, 1, 0)) { iic_release_bus(sc->sc_tag, 0); return; } if (data & LM75_CONFIG_SHUTDOWN) { data &= ~LM75_CONFIG_SHUTDOWN; if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_addr, &cmd, 1, &data, 1, 0)) { printf(", cannot wake up\n"); iic_release_bus(sc->sc_tag, 0); return; } printf(", woken up"); } iic_release_bus(sc->sc_tag, 0); sc->sc_model = LM_MODEL_LM75; sc->sc_bits = 9; if (strcmp(ia->ia_name, "lm77") == 0) { sc->sc_model = LM_MODEL_LM77; sc->sc_bits = 13; } else if (strcmp(ia->ia_name, "ds1775") == 0) { sc->sc_model = LM_MODEL_DS1775; sc->sc_bits = 9; //sc->sc_bits = DS1755_CONFIG_RESOLUTION(data); } printf("\n"); /* Initialize sensor data */ strlcpy(sc->sc_sensor.device, sc->sc_dev.dv_xname, sizeof(sc->sc_sensor.device)); sc->sc_sensor.type = SENSOR_TEMP; strlcpy(sc->sc_sensor.desc, "Temp", sizeof(sc->sc_sensor.desc)); /* Hook into the hw.sensors sysctl */ sensor_add(&sc->sc_sensor); sensor_task_register(sc, lmtemp_refresh_sensor_data, LM_POLLTIME); } int lmtemp_temp_read(struct lmtemp_softc *sc, uint8_t which, int *valp) { u_int8_t cmd, buf[2]; int error; cmd = which; error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr, &cmd, 1, buf, 2, 0); if (error) return (error); /* Some chips return transient 0's.. we try next time */ if (buf[0] == 0x00 && buf[1] == 0x00) return (1); /* convert to half-degrees C */ *valp = ((buf[0] << 8) | buf[1]) / (1 << (16 - sc->sc_bits)); return (0); } void lmtemp_refresh_sensor_data(void *aux) { struct lmtemp_softc *sc = aux; int val; int error; error = lmtemp_temp_read(sc, LM75_REG_TEMP, &val); if (error) { #if 0 printf("%s: unable to read temperature, error = %d\n", sc->sc_dev.dv_xname, error); #endif sc->sc_sensor.flags |= SENSOR_FINVALID; return; } sc->sc_sensor.value = val * 500000 + 273150000; sc->sc_sensor.flags &= ~SENSOR_FINVALID; }