/*      $NetBSD: sdtemp.c,v 1.41 2021/12/01 21:33:19 msaitoh Exp $        */

/*
 * Copyright (c) 2009 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Paul Goyette.
 *
 * 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sdtemp.c,v 1.41 2021/12/01 21:33:19 msaitoh Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kmem.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <sys/endian.h>
#include <sys/module.h>

#include <dev/sysmon/sysmonvar.h>

#include <dev/i2c/i2cvar.h>
#include <dev/i2c/sdtemp_reg.h>

struct sdtemp_softc {
        device_t sc_dev;
        i2c_tag_t sc_tag;
        int sc_address;

        struct sysmon_envsys *sc_sme;
        envsys_data_t *sc_sensor;
        sysmon_envsys_lim_t sc_deflims;
        uint32_t sc_defprops;
        int sc_resolution;
        uint16_t sc_mfgid;
        uint16_t sc_devid;
        uint16_t sc_devid_masked;
        uint16_t sc_capability;
};

static int  sdtemp_match(device_t, cfdata_t, void *);
static void sdtemp_attach(device_t, device_t, void *);
static int  sdtemp_detach(device_t, int);

CFATTACH_DECL_NEW(sdtemp, sizeof(struct sdtemp_softc),
        sdtemp_match, sdtemp_attach, sdtemp_detach, NULL);

static void     sdtemp_refresh(struct sysmon_envsys *, envsys_data_t *);
static void     sdtemp_get_limits(struct sysmon_envsys *, envsys_data_t *,
                                  sysmon_envsys_lim_t *, uint32_t *);
static void     sdtemp_set_limits(struct sysmon_envsys *, envsys_data_t *,
                                  sysmon_envsys_lim_t *, uint32_t *);
#ifdef NOT_YET
static int      sdtemp_read_8(struct sdtemp_softc *, uint8_t, uint8_t *);
static int      sdtemp_write_8(struct sdtemp_softc *, uint8_t, uint8_t);
#endif /* NOT YET */
static int      sdtemp_read_16(struct sdtemp_softc *, uint8_t, uint16_t *);
static int      sdtemp_write_16(struct sdtemp_softc *, uint8_t, uint16_t);
static uint32_t sdtemp_decode_temp(struct sdtemp_softc *, uint16_t);
static bool     sdtemp_pmf_suspend(device_t, const pmf_qual_t *);
static bool     sdtemp_pmf_resume(device_t, const pmf_qual_t *);
/* Device dependent config functions */
static void     sdtemp_config_mcp(struct sdtemp_softc *);
static void     sdtemp_config_idt(struct sdtemp_softc *);

struct sdtemp_dev_entry {
        const uint16_t sdtemp_mfg_id;
        const uint16_t sdtemp_devrev;
        const uint16_t sdtemp_mask;
        void         (*sdtemp_config)(struct sdtemp_softc *);
        const char    *sdtemp_desc;
};

/* Convert sysmon_envsys uKelvin value to simple degC */

#define __UK2C(uk) (((uk) - 273150000) / 1000000)

/* List of devices known to conform to JEDEC JC42.4 */

#define CMCP sdtemp_config_mcp
#define CIDT sdtemp_config_idt

static const struct sdtemp_dev_entry
sdtemp_dev_table[] = {
    { AT_MANUFACTURER_ID,   AT_30TS00_DEVICE_ID,     AT_30TS00_MASK,      NULL,
        "Atmel AT30TS00" },
    { AT2_MANUFACTURER_ID,  AT2_30TSE004_DEVICE_ID,  AT2_30TSE004_MASK,   NULL,
        "Atmel AT30TSE004" },
    { GT_MANUFACTURER_ID,   GT_30TS00_DEVICE_ID,     GT_30TS00_MASK,      NULL,
        "Giantec GT30TS00" },
    { GT2_MANUFACTURER_ID,  GT2_34TS02_DEVICE_ID,    GT2_34TS02_MASK,     NULL,
        "Giantec GT34TS02" },
    { MAXIM_MANUFACTURER_ID, MAX_6604_DEVICE_ID,     MAX_6604_MASK,       NULL,
        "Maxim MAX6604" },
    { MAXIM_MANUFACTURER_ID, MAX_6604_2_DEVICE_ID,   MAX_6604_MASK,       NULL,
        "Maxim MAX6604" },
    { MCP_MANUFACTURER_ID,  MCP_9804_DEVICE_ID,      MCP_9804_MASK,       CMCP,
        "Microchip Tech MCP9804" },
    { MCP_MANUFACTURER_ID,  MCP_9805_DEVICE_ID,      MCP_9805_MASK,       NULL,
        "Microchip Tech MCP9805/MCP9843" },
    { MCP_MANUFACTURER_ID,  MCP_98242_DEVICE_ID,     MCP_98242_MASK,      CMCP,
        "Microchip Tech MCP98242" },
    { MCP_MANUFACTURER_ID,  MCP_98243_DEVICE_ID,     MCP_98243_MASK,      CMCP,
        "Microchip Tech MCP98243" },
    { MCP_MANUFACTURER_ID,  MCP_98244_DEVICE_ID,     MCP_98244_MASK,      CMCP,
        "Microchip Tech MCP98244" },
    { MCP2_MANUFACTURER_ID, MCP2_EMC1501_DEVICE_ID,  MCP2_EMC1501_MASK,   NULL,
        "Microchip Tech EMC1501" },
    { ADT_MANUFACTURER_ID,  ADT_7408_DEVICE_ID,      ADT_7408_MASK,       NULL,
        "Analog Devices ADT7408" },
    { NXP_MANUFACTURER_ID,  NXP_SE98_DEVICE_ID,      NXP_SE98_MASK,       NULL,
        "NXP Semiconductors SE97B/SE98" },
    { NXP_MANUFACTURER_ID,  NXP_SE97_DEVICE_ID,      NXP_SE97_MASK,       NULL,
        "NXP Semiconductors SE97" },
    { STTS_MANUFACTURER_ID, STTS_424E_DEVICE_ID,     STTS_424E_MASK,      NULL,
        "STmicroelectronics STTS424E" },
    { STTS_MANUFACTURER_ID, STTS_424_DEVICE_ID,      STTS_424_MASK,       NULL,
        "STmicroelectronics STTS424" },
    { STTS_MANUFACTURER_ID, STTS_2002_DEVICE_ID,     STTS_2002_MASK,      NULL,
        "STmicroelectronics STTS2002" },
    { STTS_MANUFACTURER_ID, STTS_2004_DEVICE_ID,     STTS_2004_MASK,      NULL,
        "STmicroelectronics STTS2004" },
    { STTS_MANUFACTURER_ID, STTS_3000_DEVICE_ID,     STTS_3000_MASK,      NULL,
        "STmicroelectronics STTS3000" },
    { CAT_MANUFACTURER_ID,  CAT_34TS02_DEVICE_ID,    CAT_34TS02_MASK,     NULL,
        "Catalyst CAT34TS02/CAT6095" },
    { CAT_MANUFACTURER_ID,  CAT_34TS02C_DEVICE_ID,   CAT_34TS02C_MASK,    NULL,
        "Catalyst CAT34TS02C" },
    { CAT_MANUFACTURER_ID,  CAT_34TS04_DEVICE_ID,    CAT_34TS04_MASK,     NULL,
        "Catalyst CAT34TS04" },
    { IDT_MANUFACTURER_ID,  IDT_TSE2004GB2_DEVICE_ID,IDT_TSE2004GB2_MASK, NULL,
        "Integrated Device Technology TSE2004GB2" },
    { IDT_MANUFACTURER_ID,  IDT_TS3000B3_DEVICE_ID,  IDT_TS3000B3_MASK,   CIDT,
        "Integrated Device Technology TS3000B3/TSE2002B3" },
    { IDT_MANUFACTURER_ID,  IDT_TS3000GB0_DEVICE_ID, IDT_TS3000GB0_MASK,  CIDT,
        "Integrated Device Technology TS3000GB0" },
    { IDT_MANUFACTURER_ID,  IDT_TS3000GB2_DEVICE_ID, IDT_TS3000GB2_MASK,  CIDT,
        "Integrated Device Technology TS3000GB2" },
    { IDT_MANUFACTURER_ID,  IDT_TS3001GB2_DEVICE_ID, IDT_TS3001GB2_MASK,  CIDT,
        "Integrated Device Technology TS3001GB2" },
    /*
     * Don't change the location of the following two entries. Device specific
     * entry must be located at above.
     */
    { 0,                    TSE2004AV_ID,            TSE2004AV_MASK,      NULL,
        "TSE2004av compliant device (generic driver)" },
    { 0, 0, 0, NULL, "Unknown" }
};

#undef CMCP
#undef CIDT

static const char *temp_resl[] = {
        "0.5C",
        "0.25C",
        "0.125C",
        "0.0625C"
};

static int
sdtemp_lookup(uint16_t mfg, uint16_t devrev)
{
        int i;

        for (i = 0; sdtemp_dev_table[i].sdtemp_mfg_id; i++) {
                if (mfg != sdtemp_dev_table[i].sdtemp_mfg_id)
                        continue;
                if ((devrev & sdtemp_dev_table[i].sdtemp_mask) ==
                    sdtemp_dev_table[i].sdtemp_devrev)
                        break;
        }
        /* Check TSE2004av */
        if ((sdtemp_dev_table[i].sdtemp_mfg_id == 0)
            && (SDTEMP_IS_TSE2004AV(devrev) == 0))
                        i++; /* Unknown */

        return i;
}

static int
sdtemp_match(device_t parent, cfdata_t cf, void *aux)
{
        struct i2c_attach_args *ia = aux;
        uint16_t mfgid, devid, cap;
        struct sdtemp_softc sc;
        int i, error;

        sc.sc_tag = ia->ia_tag;
        sc.sc_address = ia->ia_addr;

        if ((ia->ia_addr & SDTEMP_ADDRMASK) != SDTEMP_ADDR)
                return 0;

        /*
         * Verify that we can read the manufacturer ID, Device ID and the
         * capability
         */
        error = iic_acquire_bus(sc.sc_tag, 0);
        if (error)
                return 0;
        error = sdtemp_read_16(&sc, SDTEMP_REG_MFG_ID,  &mfgid) |
                sdtemp_read_16(&sc, SDTEMP_REG_DEV_REV, &devid) |
                sdtemp_read_16(&sc, SDTEMP_REG_CAPABILITY, &cap);
        iic_release_bus(sc.sc_tag, 0);

        if (error)
                return 0;

        i = sdtemp_lookup(mfgid, devid);
        if ((sdtemp_dev_table[i].sdtemp_mfg_id == 0) &&
            (sdtemp_dev_table[i].sdtemp_devrev == 0)) {
                aprint_debug("sdtemp: No match for mfg 0x%04x dev 0x%02x "
                    "rev 0x%02x at address 0x%02x\n", mfgid, devid >> 8,
                    devid & 0xff, sc.sc_address);
                return 0;
        }

        /*
         * Check by SDTEMP_IS_TSE2004AV() might not be enough, so check the
         * alarm capability, too.
         */
        if ((cap & SDTEMP_CAP_HAS_ALARM) == 0)
                return 0;

        return I2C_MATCH_ADDRESS_AND_PROBE;
}

static void
sdtemp_attach(device_t parent, device_t self, void *aux)
{
        struct sdtemp_softc *sc = device_private(self);
        struct i2c_attach_args *ia = aux;
        uint16_t mfgid, devid;
        int i, error;

        sc->sc_tag = ia->ia_tag;
        sc->sc_address = ia->ia_addr;
        sc->sc_dev = self;

        error = iic_acquire_bus(sc->sc_tag, 0);
        if (error)
                return;

        if ((error = sdtemp_read_16(sc, SDTEMP_REG_MFG_ID,  &mfgid)) != 0 ||
            (error = sdtemp_read_16(sc, SDTEMP_REG_DEV_REV, &devid)) != 0) {
                iic_release_bus(sc->sc_tag, 0);
                aprint_error(": attach error %d\n", error);
                return;
        }
        sc->sc_mfgid = mfgid;
        sc->sc_devid = devid;
        i = sdtemp_lookup(mfgid, devid);
        sc->sc_devid_masked = devid & sdtemp_dev_table[i].sdtemp_mask;

        aprint_naive(": Temp Sensor\n");
        aprint_normal(": %s Temp Sensor\n", sdtemp_dev_table[i].sdtemp_desc);

        if (sdtemp_dev_table[i].sdtemp_mfg_id == 0) {
                if (SDTEMP_IS_TSE2004AV(devid))
                        aprint_normal_dev(self, "TSE2004av compliant. "
                            "Manufacturer ID 0x%04hx, Device revision 0x%02x\n",
                            mfgid, devid & TSE2004AV_REV);
                else {
                        aprint_error_dev(self,
                            "mfg 0x%04x dev 0x%02x rev 0x%02x at addr 0x%02x\n",
                            mfgid, devid >> 8, devid & 0xff, ia->ia_addr);
                        iic_release_bus(sc->sc_tag, 0);
                        aprint_error_dev(self, "It should no happen. "
                            "Why attach() found me?\n");
                        return;
                }
        }

        error = sdtemp_read_16(sc, SDTEMP_REG_CAPABILITY, &sc->sc_capability);
        aprint_debug_dev(self, "capability reg = %04x\n", sc->sc_capability);
        sc->sc_resolution
            = __SHIFTOUT(sc->sc_capability, SDTEMP_CAP_RESOLUTION);
        /*
         * Call device dependent function here. Currently, it's used for
         * the resolution.
         *
         * IDT's devices and some Microchip's devices have the resolution
         * register in the vendor specific registers area. The devices'
         * resolution bits in the capability register are not the maximum
         * resolution but the current value of the setting.
         */
        if (sdtemp_dev_table[i].sdtemp_config != NULL)
                sdtemp_dev_table[i].sdtemp_config(sc);

        aprint_normal_dev(self, "%s accuracy",
            (sc->sc_capability & SDTEMP_CAP_ACCURACY_1C) ? "high" : "default");
        if ((sc->sc_capability & SDTEMP_CAP_WIDER_RANGE) != 0)
                aprint_normal(", wider range");
        aprint_normal(", %s resolution", temp_resl[sc->sc_resolution]);
        if ((sc->sc_capability & SDTEMP_CAP_VHV) != 0)
                aprint_debug(", high voltage standoff");
        aprint_debug(", %s timeout",
            (sc->sc_capability & SDTEMP_CAP_TMOUT) ? "25-35ms" : "10-60ms");
        if ((sc->sc_capability & SDTEMP_CAP_EVSD) != 0)
                aprint_normal(", event with shutdown");
        aprint_normal("\n");
        /*
         * Alarm capability is required;  if not present, this is likely
         * not a real sdtemp device.
         */
        if (error != 0 || (sc->sc_capability & SDTEMP_CAP_HAS_ALARM) == 0) {
                iic_release_bus(sc->sc_tag, 0);
                aprint_error_dev(self,
                    "required alarm capability not present!\n");
                return;
        }
        /* Set the configuration to defaults. */
        error = sdtemp_write_16(sc, SDTEMP_REG_CONFIG, 0);
        if (error != 0) {
                iic_release_bus(sc->sc_tag, 0);
                aprint_error_dev(self, "error %d writing config register\n",
                    error);
                return;
        }
        iic_release_bus(sc->sc_tag, 0);

        /* Hook us into the sysmon_envsys subsystem */
        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 = sdtemp_refresh;
        sc->sc_sme->sme_get_limits = sdtemp_get_limits;
        sc->sc_sme->sme_set_limits = sdtemp_set_limits;

        sc->sc_sensor = kmem_zalloc(sizeof(envsys_data_t), KM_SLEEP);

        /* Initialize sensor data. */
        sc->sc_sensor->units =  ENVSYS_STEMP;
        sc->sc_sensor->state = ENVSYS_SINVALID;
        sc->sc_sensor->flags |= ENVSYS_FMONLIMITS;
        (void)strlcpy(sc->sc_sensor->desc, device_xname(self),
            sizeof(sc->sc_sensor->desc));
        snprintf(sc->sc_sensor->desc, sizeof(sc->sc_sensor->desc),
            "DIMM %d temperature", sc->sc_address - SDTEMP_ADDR);

        /* Now attach the sensor */
        if (sysmon_envsys_sensor_attach(sc->sc_sme, sc->sc_sensor)) {
                aprint_error_dev(self, "unable to attach sensor\n");
                goto bad;
        }

        /* Register the device */
        error = sysmon_envsys_register(sc->sc_sme);
        if (error) {
                aprint_error_dev(self, "error %d registering with sysmon\n",
                    error);
                goto bad;
        }

        if (!pmf_device_register(self, sdtemp_pmf_suspend, sdtemp_pmf_resume))
                aprint_error_dev(self, "couldn't establish power handler\n");

        /* Retrieve and display hardware monitor limits */
        sdtemp_get_limits(sc->sc_sme, sc->sc_sensor, &sc->sc_deflims,
            &sc->sc_defprops);
        aprint_normal_dev(self, "Hardware limits: ");
        i = 0;
        if (sc->sc_defprops & PROP_WARNMIN) {
                aprint_normal("low %dC",
                              __UK2C(sc->sc_deflims.sel_warnmin));
                i++;
        }
        if (sc->sc_defprops & PROP_WARNMAX) {
                aprint_normal("%shigh %dC ", (i)?", ":"",
                              __UK2C(sc->sc_deflims.sel_warnmax));
                i++;
        }
        if (sc->sc_defprops & PROP_CRITMAX) {
                aprint_normal("%scritical %dC ", (i)?", ":"",
                              __UK2C(sc->sc_deflims.sel_critmax));
                i++;
        }
        aprint_normal("%s\n", (i)?"":"none set");

        return;

bad:
        kmem_free(sc->sc_sensor, sizeof(envsys_data_t));
        sysmon_envsys_destroy(sc->sc_sme);
        sc->sc_sme = NULL;
}

static int
sdtemp_detach(device_t self, int flags)
{
        struct sdtemp_softc *sc = device_private(self);

        pmf_device_deregister(self);

        if (sc->sc_sme)
                sysmon_envsys_unregister(sc->sc_sme);
        if (sc->sc_sensor)
                kmem_free(sc->sc_sensor, sizeof(envsys_data_t));

        return 0;
}

/* Retrieve current limits from device, and encode in uKelvins */
static void
sdtemp_get_limits(struct sysmon_envsys *sme, envsys_data_t *edata,
                  sysmon_envsys_lim_t *limits, uint32_t *props)
{
        struct sdtemp_softc *sc = sme->sme_cookie;
        uint16_t lim;

        *props = 0;
        if (iic_acquire_bus(sc->sc_tag, 0) != 0)
                return;

        if (sdtemp_read_16(sc, SDTEMP_REG_LOWER_LIM, &lim) == 0 && lim != 0) {
                limits->sel_warnmin = sdtemp_decode_temp(sc, lim);
                *props |= PROP_WARNMIN;
        }
        if (sdtemp_read_16(sc, SDTEMP_REG_UPPER_LIM, &lim) == 0 && lim != 0) {
                limits->sel_warnmax = sdtemp_decode_temp(sc, lim);
                *props |= PROP_WARNMAX;
        }
        if (sdtemp_read_16(sc, SDTEMP_REG_CRIT_LIM, &lim) == 0 && lim != 0) {
                limits->sel_critmax = sdtemp_decode_temp(sc, lim);
                *props |= PROP_CRITMAX;
        }
        iic_release_bus(sc->sc_tag, 0);
        if (*props != 0)
                *props |= PROP_DRIVER_LIMITS;
}

/* Send current limit values to the device */
static void
sdtemp_set_limits(struct sysmon_envsys *sme, envsys_data_t *edata,
                  sysmon_envsys_lim_t *limits, uint32_t *props)
{
        uint16_t val;
        struct sdtemp_softc *sc = sme->sme_cookie;

        if (limits == NULL) {
                limits = &sc->sc_deflims;
                props  = &sc->sc_defprops;
        }
        if (iic_acquire_bus(sc->sc_tag, 0) != 0)
                return;

        if (*props & PROP_WARNMIN) {
                val = __UK2C(limits->sel_warnmin);
                (void)sdtemp_write_16(sc, SDTEMP_REG_LOWER_LIM,
                                        (val << 4) & SDTEMP_TEMP_MASK);
        }
        if (*props & PROP_WARNMAX) {
                val = __UK2C(limits->sel_warnmax);
                (void)sdtemp_write_16(sc, SDTEMP_REG_UPPER_LIM,
                                        (val << 4) & SDTEMP_TEMP_MASK);
        }
        if (*props & PROP_CRITMAX) {
                val = __UK2C(limits->sel_critmax);
                (void)sdtemp_write_16(sc, SDTEMP_REG_CRIT_LIM,
                                        (val << 4) & SDTEMP_TEMP_MASK);
        }
        iic_release_bus(sc->sc_tag, 0);

        /*
         * If at least one limit is set that we can handle, and no
         * limits are set that we cannot handle, tell sysmon that
         * the driver will take care of monitoring the limits!
         */
        if (*props & (PROP_CRITMIN | PROP_BATTCAP | PROP_BATTWARN))
                *props &= ~PROP_DRIVER_LIMITS;
        else if (*props & PROP_LIMITS)
                *props |= PROP_DRIVER_LIMITS;
        else
                *props &= ~PROP_DRIVER_LIMITS;
}

#ifdef NOT_YET  /* All registers on these sensors are 16-bits */

/* Read a 8-bit value from a register */
static int
sdtemp_read_8(struct sdtemp_softc *sc, uint8_t reg, uint8_t *valp)
{
        int error;

        error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
            sc->sc_address, &reg, 1, valp, sizeof(*valp), 0);

        return error;
}

static int
sdtemp_write_8(struct sdtemp_softc *sc, uint8_t reg, uint8_t val)
{
        return iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
            sc->sc_address, &reg, 1, &val, sizeof(val), 0);
}
#endif /* NOT_YET */

/* Read a 16-bit value from a register */
static int
sdtemp_read_16(struct sdtemp_softc *sc, uint8_t reg, uint16_t *valp)
{
        int error;

        error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
            sc->sc_address, &reg, 1, valp, sizeof(*valp), 0);
        if (error)
                return error;

        *valp = be16toh(*valp);

        return 0;
}

static int
sdtemp_write_16(struct sdtemp_softc *sc, uint8_t reg, uint16_t val)
{
        uint16_t temp;

        temp = htobe16(val);
        return iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
            sc->sc_address, &reg, 1, &temp, sizeof(temp), 0);
}

static uint32_t
sdtemp_decode_temp(struct sdtemp_softc *sc, uint16_t temp)
{
        uint32_t val;
        int32_t stemp;

        /* Get only the temperature bits */
        temp &= SDTEMP_TEMP_MASK;

        /* If necessary, extend the sign bit */
        if ((sc->sc_capability & SDTEMP_CAP_WIDER_RANGE) &&
            (temp & SDTEMP_TEMP_NEGATIVE))
                temp |= SDTEMP_TEMP_SIGN_EXT;

        /* Mask off only bits valid within current resolution */
        temp &= ~(0x7 >> sc->sc_resolution);

        /* Treat as signed and extend to 32-bits */
        stemp = (int16_t)temp;

        /* Now convert from 0.0625 (1/16) deg C increments to microKelvins */
        val = (stemp * 62500) + 273150000;

        return val;
}

static void
sdtemp_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
{
        struct sdtemp_softc *sc = sme->sme_cookie;
        uint16_t val;
        int error;

        error = iic_acquire_bus(sc->sc_tag, 0);
        if (error) {
                edata->state = ENVSYS_SINVALID;
                return;
        }

        error = sdtemp_read_16(sc, SDTEMP_REG_AMBIENT_TEMP, &val);
        iic_release_bus(sc->sc_tag, 0);

        if (error) {
                edata->state = ENVSYS_SINVALID;
                return;
        }

        edata->value_cur = sdtemp_decode_temp(sc, val);

        /* Now check for limits */
        if ((edata->upropset & PROP_DRIVER_LIMITS) == 0)
                edata->state = ENVSYS_SVALID;
        else if ((val & SDTEMP_ABOVE_CRIT) &&
                    (edata->upropset & PROP_CRITMAX))
                edata->state = ENVSYS_SCRITOVER;
        else if ((val & SDTEMP_ABOVE_UPPER) &&
                    (edata->upropset & PROP_WARNMAX))
                edata->state = ENVSYS_SWARNOVER;
        else if ((val & SDTEMP_BELOW_LOWER) &&
                    (edata->upropset & PROP_WARNMIN))
                edata->state = ENVSYS_SWARNUNDER;
        else
                edata->state = ENVSYS_SVALID;
}

/*
 * Power management functions
 *
 * We go into "shutdown" mode at suspend time, and return to normal
 * mode upon resume.  This reduces power consumption by disabling
 * the A/D converter.
 */

static bool
sdtemp_pmf_suspend(device_t dev, const pmf_qual_t *qual)
{
        struct sdtemp_softc *sc = device_private(dev);
        int error;
        uint16_t config;

        error = iic_acquire_bus(sc->sc_tag, 0);
        if (error != 0)
                return false;

        error = sdtemp_read_16(sc, SDTEMP_REG_CONFIG, &config);
        if (error == 0) {
                config |= SDTEMP_CONFIG_SHUTDOWN_MODE;
                error = sdtemp_write_16(sc, SDTEMP_REG_CONFIG, config);
        }
        iic_release_bus(sc->sc_tag, 0);
        return (error == 0);
}

static bool
sdtemp_pmf_resume(device_t dev, const pmf_qual_t *qual)
{
        struct sdtemp_softc *sc = device_private(dev);
        int error;
        uint16_t config;

        error = iic_acquire_bus(sc->sc_tag, 0);
        if (error != 0)
                return false;

        error = sdtemp_read_16(sc, SDTEMP_REG_CONFIG, &config);
        if (error == 0) {
                config &= ~SDTEMP_CONFIG_SHUTDOWN_MODE;
                error = sdtemp_write_16(sc, SDTEMP_REG_CONFIG, config);
        }
        iic_release_bus(sc->sc_tag, 0);
        return (error == 0);
}

/* Device dependent config functions */

static void
sdtemp_config_mcp(struct sdtemp_softc *sc)
{
        int rv;
        uint8_t resolreg;

        /* Note that MCP9805 has no resolution register */
        switch (sc->sc_devid_masked) {
        case MCP_9804_DEVICE_ID:
        case MCP_98242_DEVICE_ID:
        case MCP_98243_DEVICE_ID:
                resolreg = SDTEMP_REG_MCP_RESOLUTION_9804;
                break;
        case MCP_98244_DEVICE_ID:
                resolreg = SDTEMP_REG_MCP_RESOLUTION_98244;
                break;
        default:
                aprint_error("%s: %s: unknown device ID (%04hx)\n",
                    device_xname(sc->sc_dev), __func__, sc->sc_devid_masked);
                return;
        }

        /*
         * Set resolution to the max.
         *
         * Even if it fails, the resolution will be the default. It's not a
         * fatal error.
         */
        rv = sdtemp_write_16(sc, resolreg, SDTEMP_CAP_RESOLUTION_MAX);
        if (rv == 0)
                sc->sc_resolution = SDTEMP_CAP_RESOLUTION_MAX;
        else
                aprint_debug_dev(sc->sc_dev,
                    "error %d writing resolution register\n", rv);
}

static void
sdtemp_config_idt(struct sdtemp_softc *sc)
{
        int rv;

        /*
         * Set resolution to the max.
         *
         * Even if it fails, the resolution will be the default. It's not a
         * fatal error.
         */
        rv = sdtemp_write_16(sc, SDTEMP_REG_IDT_RESOLUTION,
            __SHIFTIN(SDTEMP_CAP_RESOLUTION_MAX, SDTEMP_CAP_RESOLUTION));
        if (rv == 0)
                sc->sc_resolution = SDTEMP_CAP_RESOLUTION_MAX;
        else
                aprint_debug_dev(sc->sc_dev,
                    "error %d writing resolution register\n", rv);
}

MODULE(MODULE_CLASS_DRIVER, sdtemp, "i2cexec,sysmon_envsys");

#ifdef _MODULE
#include "ioconf.c"
#endif

static int
sdtemp_modcmd(modcmd_t cmd, void *opaque)
{
        int error = 0;

        switch (cmd) {
        case MODULE_CMD_INIT:
#ifdef _MODULE
                error = config_init_component(cfdriver_ioconf_sdtemp,
                    cfattach_ioconf_sdtemp, cfdata_ioconf_sdtemp);
#endif
                return error;
        case MODULE_CMD_FINI:
#ifdef _MODULE
                error = config_fini_component(cfdriver_ioconf_sdtemp,
                    cfattach_ioconf_sdtemp, cfdata_ioconf_sdtemp);
#endif
                return error;
        default:
                return ENOTTY;
        }
}