/* $NetBSD: mcp980x.c,v 1.1 2013/05/06 22:04:12 rkujawa Exp $ */ /*- * Copyright (c) 2013 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Radoslaw Kujawa. * * 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. */ /* * Microchip MCP9800/1/2/3 2-Wire High-Accuracy Temperature Sensor driver. * TODO: everything besides simple temperature read with default configuration. * * Note: MCP9805 is different and is supported by the sdtemp(4) driver. */ #include __KERNEL_RCSID(0, "$NetBSD: mcp980x.c,v 1.1 2013/05/06 22:04:12 rkujawa Exp $"); #include #include #include #include #include #include #include #include #include #include struct mcp980x_softc { device_t sc_dev; i2c_tag_t sc_tag; i2c_addr_t sc_addr; /* envsys(4) stuff */ struct sysmon_envsys *sc_sme; envsys_data_t sc_sensor; kmutex_t sc_lock; }; static int mcp980x_match(device_t, cfdata_t, void *); static void mcp980x_attach(device_t, device_t, void *); /*static uint8_t mcp980x_reg_read_1(struct mcp980x_softc *sc, uint8_t);*/ static uint16_t mcp980x_reg_read_2(struct mcp980x_softc *sc, uint8_t reg); static uint32_t mcp980x_temperature(struct mcp980x_softc *sc); static void mcp980x_envsys_register(struct mcp980x_softc *); static void mcp980x_envsys_refresh(struct sysmon_envsys *, envsys_data_t *); CFATTACH_DECL_NEW(mcp980x, sizeof (struct mcp980x_softc), mcp980x_match, mcp980x_attach, NULL, NULL); static int mcp980x_match(device_t parent, cfdata_t cf, void *aux) { /* * No sane way to probe? Perhaps at least try to match constant part * of the I2Caddress. */ return 1; } static void mcp980x_attach(device_t parent, device_t self, void *aux) { struct mcp980x_softc *sc = device_private(self); struct i2c_attach_args *ia = aux; sc->sc_dev = self; sc->sc_addr = ia->ia_addr; sc->sc_tag = ia->ia_tag; aprint_normal(": Microchip MCP980x Temperature Sensor\n"); mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE); mcp980x_envsys_register(sc); } static uint16_t mcp980x_reg_read_2(struct mcp980x_softc *sc, uint8_t reg) { uint8_t wbuf[2]; uint16_t rv; if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL) != 0) { aprint_error_dev(sc->sc_dev, "cannot acquire bus for read\n"); return 0; } wbuf[0] = reg; if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr, wbuf, 1, &rv, 2, I2C_F_POLL)) { aprint_error_dev(sc->sc_dev, "cannot execute operation\n"); iic_release_bus(sc->sc_tag, I2C_F_POLL); return 0; } iic_release_bus(sc->sc_tag, I2C_F_POLL); return be16toh(rv); } /* Will need that later for reading config register. */ /* static uint8_t mcp980x_reg_read_1(struct mcp980x_softc *sc, uint8_t reg) { uint8_t rv, wbuf[2]; if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL) != 0) { aprint_error_dev(sc->sc_dev, "cannot acquire bus for read\n"); return 0; } wbuf[0] = reg; if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr, wbuf, 1, &rv, 1, I2C_F_POLL)) { aprint_error_dev(sc->sc_dev, "cannot execute operation\n"); iic_release_bus(sc->sc_tag, I2C_F_POLL); return 0; } iic_release_bus(sc->sc_tag, I2C_F_POLL); return rv; }*/ /* Get temperature in microKelvins. */ static uint32_t mcp980x_temperature(struct mcp980x_softc *sc) { uint16_t raw; uint32_t rv, uk, basedegc; raw = mcp980x_reg_read_2(sc, MCP980X_AMBIENT_TEMP); basedegc = (raw & MCP980X_AMBIENT_TEMP_DEGREES) >> MCP980X_AMBIENT_TEMP_DEGREES_SHIFT; uk = 1000000 * basedegc; if (raw & MCP980X_AMBIENT_TEMP_05DEGREE) uk += 500000; if (raw & MCP980X_AMBIENT_TEMP_025DEGREE) uk += 250000; if (raw & MCP980X_AMBIENT_TEMP_0125DEGREE) uk += 125000; if (raw & MCP980X_AMBIENT_TEMP_00625DEGREE) uk += 62500; if (raw & MCP980X_AMBIENT_TEMP_SIGN) rv = 273150000U - uk; else rv = 273150000U + uk; return rv; } static void mcp980x_envsys_register(struct mcp980x_softc *sc) { sc->sc_sme = sysmon_envsys_create(); strlcpy(sc->sc_sensor.desc, "Ambient temp", sizeof(sc->sc_sensor.desc)); sc->sc_sensor.units = ENVSYS_STEMP; sc->sc_sensor.state = ENVSYS_SINVALID; if (sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor)) { aprint_error_dev(sc->sc_dev, "error attaching sensor\n"); return; } sc->sc_sme->sme_name = device_xname(sc->sc_dev); sc->sc_sme->sme_cookie = sc; sc->sc_sme->sme_refresh = mcp980x_envsys_refresh; if (sysmon_envsys_register(sc->sc_sme)) { aprint_error_dev(sc->sc_dev, "unable to register in sysmon\n"); sysmon_envsys_destroy(sc->sc_sme); } } static void mcp980x_envsys_refresh(struct sysmon_envsys *sme, envsys_data_t *edata) { struct mcp980x_softc *sc = sme->sme_cookie; mutex_enter(&sc->sc_lock); edata->value_cur = mcp980x_temperature(sc); edata->state = ENVSYS_SVALID; mutex_exit(&sc->sc_lock); }