/* $NetBSD: adadc.c,v 1.12 2025/09/17 13:42:42 thorpej Exp $ */

/*-
 * Copyright (c) 2018 Michael Lorenz
 * All rights reserved.
 *
 * 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.
 */

/*
 * a driver for Analog Devices AD7417 temperature sensors / ADCs
 * very much macppc only for now since we need calibaration data to make sense
 * of the ADC inputs
 * info on how to get these from FreeBSD and Linux
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: adadc.c,v 1.12 2025/09/17 13:42:42 thorpej Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/conf.h>
#include <sys/bus.h>

#include <dev/i2c/i2cvar.h>

#include <dev/sysmon/sysmonvar.h>

#include <dev/ofw/openfirm.h>

/* commands */
#define ADADC_TEMP      0x00    /* temperature, 16bit */
#define ADADC_CONFIG    0x01    /* 8bit */
#define ADADC_THYST     0x02    /* 16bit */
#define ADADC_TOTI      0x03    /* 16bit, temperature threshold */
#define ADADC_ADC       0x04    /* 16bit, ADC value */
#define ADADC_CONFIG2   0x05    /* 8bit */

/* 
 * registers
 * ADADC_TEMP has signed temperature in C in first byte, left aligned fraction
 * in 2nd byte.
 */

#define ADADC_CFG_CHANNEL_0     0x00
#define ADADC_CFG_CHANNEL_1     0x20
#define ADADC_CFG_CHANNEL_2     0x40
#define ADADC_CFG_CHANNEL_3     0x60
#define ADADC_CFG_CHANNEL_4     0x80
#define ADADC_CFG_CHANNEL_MASK  0xe0
#define ADADC_CFG_FAULT_MASK    0x18
#define ADADC_CFG_OTI_POL       0x04    /* overtemp output polarity */
#define ADADC_CFG_INTMODE       0x02    /* interrupt mode */
#define ADADC_CFG_SHUTDOWN      0x01    /* shutdown mode */


struct adadc_softc {
        device_t        sc_dev;
        i2c_tag_t       sc_i2c;
        i2c_addr_t      sc_addr;

        struct sysmon_envsys *sc_sme;
        envsys_data_t   sc_sensors[5];
        int             sc_nsensors;
        int             sc_diode_offset, sc_diode_slope;
};

static int      adadc_match(device_t, cfdata_t, void *);
static void     adadc_attach(device_t, device_t, void *);

static void     adadc_sensors_refresh(struct sysmon_envsys *, envsys_data_t *);

CFATTACH_DECL_NEW(adadc, sizeof(struct adadc_softc),
    adadc_match, adadc_attach, NULL, NULL);

static const struct device_compatible_entry compat_data[] = {
        { .compat = "ad7417" },
        DEVICE_COMPAT_EOL
};

/* calibaration table from Darwin via Linux */
static int slope[5] = {0, 0, 0x0320, 0x00a0, 0x1f40};

static int
adadc_match(device_t parent, cfdata_t match, void *aux)
{
        struct i2c_attach_args *ia = aux;
        int match_result;

        if (iic_use_direct_match(ia, match, compat_data, &match_result))
                return match_result;

        /*
         * XXX
         * this driver is pretty much useless without OF, should
         * probably remove this
         */
        if ((ia->ia_addr & 0x2b) == 0x2b)
                return I2C_MATCH_ADDRESS_ONLY;

        return 0;
}

static void
adadc_attach(device_t parent, device_t self, void *aux)
{
        struct adadc_softc *sc = device_private(self);
        struct i2c_attach_args *ia = aux;
        envsys_data_t *s;
        int error, ch;
        uint32_t eeprom[40];
        char loc[256];
        int which_cpu;
        int phandle = devhandle_to_of(device_handle(self));

        sc->sc_dev = self;
        sc->sc_i2c = ia->ia_tag;
        sc->sc_addr = ia->ia_addr;

        aprint_naive("\n");
        aprint_normal(": AD7417\n");

        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 = adadc_sensors_refresh;
        sc->sc_nsensors = 0;

        /*
         * XXX
         * without OpenFirmware telling us how to interpret the ADC inputs we
         * should probably just expose the temperature and four ENVSYS_INTEGERs
         */
        which_cpu = 0;
        ch = OF_child(phandle);
        if (ch == 0) {
                /* old style info */
                int len, idx = 0, reg = 0;
                uint32_t ids[16];
                char buffer[256];
                len = OF_getprop(phandle, "hwsensor-id", ids, 64);
                OF_getprop(phandle, "hwsensor-location", buffer, 256);
                while (len > 0) {
                        strcpy(loc, &buffer[idx]);
                        s = &sc->sc_sensors[sc->sc_nsensors];
                        s->state = ENVSYS_SINVALID;
                        /*
                         * this setup matches my 1.8GHz PCI-X G5, Linux and
                         * FreeBSD hardcode these as well so we should be safe
                         */
                        switch (reg) {
                                case 0:
                                        if (strstr(loc, "CPU B") != NULL)
                                                which_cpu = 1;
                                        /* FALLTHROUGH */               
                                case 1:
                                        s->units = ENVSYS_STEMP;
                                        break;
                                case 2:
                                case 4:
                                        s->units = ENVSYS_SAMPS;
                                        break;
                                case 3:
                                        s->units = ENVSYS_SVOLTS_DC;
                                        break;
                                default:
                                        s->units = ENVSYS_INTEGER;
                        }
                        strncpy(s->desc, loc, sizeof(s->desc));
                        s->private = reg;
                        sysmon_envsys_sensor_attach(sc->sc_sme, s);
                        sc->sc_nsensors++;
                        len -= 4;
                        idx += strlen(loc) + 1;
                        reg++;
                }
        } else {
                while (ch != 0) {
                        if (OF_getprop(ch, "location", loc, 32) > 0) {
                                int reg = 0;
                                OF_getprop(ch, "reg", &reg, sizeof(reg));
                                s = &sc->sc_sensors[sc->sc_nsensors];
                                s->state = ENVSYS_SINVALID;
                                /*
                                 * this setup matches my 2x 2.5GHz PCI-X G5, Linux and
                                 * FreeBSD hardcode these as well so we should be safe
                                 */
                                switch (reg) {
                                case 0:
                                        if (strstr(loc, "CPU B") != NULL)
                                                which_cpu = 1;
                                        /* FALLTHROUGH */               
                                case 1:
                                        s->units = ENVSYS_STEMP;
                                        break;
                                case 2:
                                case 4:
                                        s->units = ENVSYS_SAMPS;
                                        break;
                                case 3:
                                        s->units = ENVSYS_SVOLTS_DC;
                                        break;
                                default:
                                        s->units = ENVSYS_INTEGER;
                                }
                                strncpy(s->desc, loc, sizeof(s->desc));
                                s->private = reg;
                                sysmon_envsys_sensor_attach(sc->sc_sme, s);
                                sc->sc_nsensors++;
                        }
                        ch = OF_peer(ch);
                }
        }
        aprint_debug_dev(self, "monitoring CPU %d\n", which_cpu);
        error = get_cpuid(which_cpu, (uint8_t *)eeprom);
        if (error >= 0) {
                sc->sc_diode_slope = eeprom[0x11] >> 16;
                sc->sc_diode_offset = (int16_t)(eeprom[0x11] & 0xffff) << 12;
        }
        sysmon_envsys_register(sc->sc_sme);
}

static void
adadc_sensors_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
{
        struct adadc_softc *sc = sme->sme_cookie;
        uint8_t cmd = ADADC_CONFIG;
        int16_t data = 0;
        uint16_t rdata;
        uint8_t cfg;
        int error, ch;

                
        iic_acquire_bus(sc->sc_i2c, 0);
        if (edata->private > 0) {
                error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP,
                    sc->sc_addr, &cmd, 1, &cfg, 1, 0);
                ch = cfg >> 5;
                /* are we on the right channel already? */
                if (ch != edata->private) {
                        /* nope */
                        cfg &= 0x1f;
                        cfg |= (edata->private & 7) << 5;
                        iic_exec(sc->sc_i2c, I2C_OP_WRITE_WITH_STOP,
                            sc->sc_addr, &cmd, 1, &cfg, 1, 0);
                }
                cmd = ADADC_ADC;
                /* now read the ADC register */
                error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP,
                    sc->sc_addr, &cmd, 1, &rdata, 2, 0);
                rdata = be16toh(rdata) >> 6;
                if (edata->private == 1) {
                        int temp;
                        temp = (rdata * sc->sc_diode_slope + 
                                sc->sc_diode_offset) >> 2;
                        /* 16.16 fixed point */
                        edata->value_cur = (temp >> 12) * 62500 + 273150000;
                } else {
                        /*
                         * the input is 10bit, so converting to 8.4 fixed point
                         * is more than enough
                         */
                        int temp = rdata * slope[edata->private];
                        edata->value_cur = (temp >> 12) * 62500;
                }
        } else {
                cmd = ADADC_TEMP;
                /* just read the temperature register */
                error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP,
                    sc->sc_addr, &cmd, 1, &data, 2, 0);
                /* 8.2 bit fixed point Celsius -> microkelvin */
                edata->value_cur = ((data >> 6) * 250000) + 273150000;
        }
        iic_release_bus(sc->sc_i2c, 0);

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