/* $NetBSD: nxp75a.c,v 1.1 2026/06/03 11:08:41 jdc Exp $ */ /*- * Copyright (c) 2026 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Julian Coleman. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include __KERNEL_RCSID(0, "$NetBSD: nxp75a.c,v 1.1 2026/06/03 11:08:41 jdc Exp $"); #include #include #include #include #include #include #include struct nxp75a_softc { device_t sc_dev; i2c_tag_t sc_tag; int sc_address; struct sysmon_envsys *sc_sme; envsys_data_t sc_sensor; uint32_t sc_otemp, sc_hyst; }; static int nxp75a_match(device_t, cfdata_t, void *); static void nxp75a_attach(device_t, device_t, void *); static int nxp75a_detach(device_t, int); void nxp75a_refresh(struct sysmon_envsys *, envsys_data_t *); void nxp75a_get_limits(struct sysmon_envsys *, envsys_data_t *, sysmon_envsys_lim_t *, uint32_t *); void nxp75a_set_limits(struct sysmon_envsys *, envsys_data_t *, sysmon_envsys_lim_t *, uint32_t *); static int nxp75a_read_temp(struct nxp75a_softc *, uint8_t, uint32_t *); static int nxp75a_write_temp(struct nxp75a_softc *, uint8_t, uint32_t); CFATTACH_DECL_NEW(nxp75a, sizeof(struct nxp75a_softc), nxp75a_match, nxp75a_attach, nxp75a_detach, NULL); static const struct device_compatible_entry compat_data[] = { { .compat = "i2c-lm75a" }, DEVICE_COMPAT_EOL }; static int nxp75a_match(device_t parent, cfdata_t cf, void *aux) { struct i2c_attach_args *ia = aux; int match_result; if (iic_use_direct_match(ia, cf, compat_data, &match_result)) return match_result; /* * Indirect config - assume config is correct! */ if ((ia->ia_addr & NXP75A_ADDRMASK) == NXP75A_ADDR) return I2C_MATCH_ADDRESS_ONLY; return 0; } static void nxp75a_attach(device_t parent, device_t self, void *aux) { struct nxp75a_softc *sc = device_private(self); struct i2c_attach_args *ia = aux; uint8_t reg, val; uint32_t tval; sc->sc_tag = ia->ia_tag; sc->sc_address = ia->ia_addr; sc->sc_dev = self; aprint_normal(": NXP LM75A temperature sensor\n"); if (iic_acquire_bus(sc->sc_tag, 0)) { aprint_error_dev(self, "unable to acquire I2C bus\n"); return; } /* Read and save overtemp (critical limit) and hysteresis */ reg = NXP75A_OVERTEMP; if (nxp75a_read_temp(sc, reg, &tval)) { iic_release_bus(sc->sc_tag, 0); aprint_error_dev(sc->sc_dev, "unable to read overtemp register\n"); return; } sc->sc_otemp = tval; reg = NXP75A_THYST; if (nxp75a_read_temp(sc, reg, &tval)) { iic_release_bus(sc->sc_tag, 0); aprint_error_dev(sc->sc_dev, "unable to read hysteresis register\n"); return; } sc->sc_hyst = tval; /* Read config, start conversion */ reg = NXP75A_CONFIG; if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_address, ®, 1, &val, 1, 0)) { iic_release_bus(sc->sc_tag, 0); aprint_error_dev(sc->sc_dev, "unable to read config register\n"); return; } if (val & NXP75A_CONF_SHUTDOWN) { val &= ~(NXP75A_CONF_SHUTDOWN); if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_address, ®, 1, &val, 1, 0)) { iic_release_bus(sc->sc_tag, 0); aprint_error_dev(sc->sc_dev, "unable to write config register\n"); return; } } iic_release_bus(sc->sc_tag, 0); sc->sc_sme = sysmon_envsys_create(); sc->sc_sme->sme_name = device_xname(self); sc->sc_sme->sme_cookie = sc; sc->sc_sme->sme_refresh = nxp75a_refresh; sc->sc_sme->sme_get_limits = nxp75a_get_limits; sc->sc_sme->sme_set_limits = nxp75a_set_limits; strlcpy(sc->sc_sensor.desc, "temperature", sizeof(sc->sc_sensor.desc)); sc->sc_sensor.units = ENVSYS_STEMP; sc->sc_sensor.state = ENVSYS_SINVALID; sc->sc_sensor.flags = ENVSYS_FMONLIMITS | ENVSYS_FHAS_ENTROPY; if (sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor)) { sysmon_envsys_destroy(sc->sc_sme); sc->sc_sme = NULL; aprint_error_dev(sc->sc_dev, "unable to attach sensor to sysmon\n"); return; } if (sysmon_envsys_register(sc->sc_sme)) { aprint_error_dev(self, "unable to register with sysmon\n"); sysmon_envsys_destroy(sc->sc_sme); sc->sc_sme = NULL; return; } } static int nxp75a_detach(device_t self, int flags) { struct nxp75a_softc *sc = device_private(self); if (sc->sc_sme != NULL) { sysmon_envsys_unregister(sc->sc_sme); sc->sc_sme = NULL; } return 0; } void nxp75a_refresh(struct sysmon_envsys *sme, envsys_data_t *edata) { struct nxp75a_softc *sc = sme->sme_cookie; uint8_t reg; uint32_t val; if (iic_acquire_bus(sc->sc_tag, 0)) return; reg = NXP75A_TEMP; if (nxp75a_read_temp(sc, reg, &val) == 0) { edata->value_cur = val; edata->state = ENVSYS_SVALID; } else { edata->state = ENVSYS_SINVALID; } iic_release_bus(sc->sc_tag, 0); } void nxp75a_get_limits(struct sysmon_envsys *sme, envsys_data_t *edata, sysmon_envsys_lim_t *limits, uint32_t *props) { struct nxp75a_softc *sc = sme->sme_cookie; uint8_t reg; uint32_t val; *props &= ~(PROP_CRITMAX | PROP_WARNMAX | PROP_WARNMIN); if (iic_acquire_bus(sc->sc_tag, 0)) return; reg = NXP75A_OVERTEMP; if (nxp75a_read_temp(sc, reg, &val) == 0) { limits->sel_critmax = val; *props |= PROP_CRITMAX; } iic_release_bus(sc->sc_tag, 0); } void nxp75a_set_limits(struct sysmon_envsys *sme, envsys_data_t *edata, sysmon_envsys_lim_t *limits, uint32_t *props) { struct nxp75a_softc *sc = sme->sme_cookie; uint8_t reg; uint32_t otemp, hyst; if (iic_acquire_bus(sc->sc_tag, 0)) return; if (limits == NULL || *props & PROP_CRITMAX) { if (limits == NULL) { /* Restore defaults */ otemp = sc->sc_otemp; hyst = sc->sc_hyst; } else { otemp = limits->sel_critmax; /* Make sure that hyst is less than overtemp */ hyst = otemp - (sc->sc_otemp - sc->sc_hyst); } reg = NXP75A_OVERTEMP; if (nxp75a_write_temp(sc, reg, otemp) == 0) { reg = NXP75A_THYST; nxp75a_write_temp(sc, reg, hyst); } } iic_release_bus(sc->sc_tag, 0); } static int nxp75a_read_temp(struct nxp75a_softc *sc, uint8_t reg, uint32_t *valp) { uint8_t buf[NXP75A_TEMP_LEN]; int err; err = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_address, ®, 1, buf, NXP75A_TEMP_LEN, 0); if (err) return err; /* * Convert the 11 high bits from the 2 bytes to a temperature in uK. * Sign-extend the MSB and add in the LSB */ *valp = (int8_t) buf[0]; *valp = (*valp << 3) + ((buf[1] >> 5) & 0x07); *valp = *valp * 125000 + 273150000; return 0; } static int nxp75a_write_temp(struct nxp75a_softc *sc, uint8_t reg, uint32_t val) { uint8_t buf[NXP75A_TEMP_LEN]; uint32_t temp; /* Convert the temperature in uK to 11 high bits in 2 bytes.*/ temp = (int) (val - 273150000) / 125000 ; buf[0] = (temp >> 3) & 0xff; buf[1] = (temp << 5) & 0xe0; return iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_address, ®, 1, buf, NXP75A_TEMP_LEN, 0); }