/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2010 Andreas Tobler
 *
 * 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 AUTHOR ``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 AUTHOR 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/param.h>
#include <sys/bus.h>
#include <sys/systm.h>
#include <sys/module.h>
#include <sys/callout.h>
#include <sys/conf.h>
#include <sys/cpu.h>
#include <sys/ctype.h>
#include <sys/kernel.h>
#include <sys/reboot.h>
#include <sys/rman.h>
#include <sys/sysctl.h>
#include <sys/limits.h>

#include <machine/bus.h>
#include <machine/md_var.h>

#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iiconf.h>

#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <powerpc/powermac/powermac_thermal.h>

/* CPU A/B sensors, temp and adc: AD7417. */

#define AD7417_TEMP         0x00
#define AD7417_CONFIG       0x01
#define AD7417_ADC          0x04
#define AD7417_CONFIG2      0x05
#define AD7417_CONFMASK     0xe0

uint8_t adc741x_config;

struct ad7417_sensor {
        struct  pmac_therm therm;
        device_t dev;
        int     id;
        enum {
                ADC7417_TEMP_SENSOR,
                ADC7417_ADC_SENSOR
        } type;
};

struct write_data {
        uint8_t reg;
        uint8_t val;
};

struct read_data {
        uint8_t reg;
        uint16_t val;
};

/* Regular bus attachment functions */
static int ad7417_probe(device_t);
static int ad7417_attach(device_t);

/* Utility functions */
static int ad7417_sensor_sysctl(SYSCTL_HANDLER_ARGS);
static int ad7417_write(device_t dev, uint32_t addr, uint8_t reg,
                        uint8_t *buf, int len);
static int ad7417_read_1(device_t dev, uint32_t addr, uint8_t reg,
                         uint8_t *data);
static int ad7417_read_2(device_t dev, uint32_t addr, uint8_t reg,
                         uint16_t *data);
static int ad7417_write_read(device_t dev, uint32_t addr,
                             struct write_data out, struct read_data *in);
static int ad7417_diode_read(struct ad7417_sensor *sens);
static int ad7417_adc_read(struct ad7417_sensor *sens);
static int ad7417_sensor_read(struct ad7417_sensor *sens);

struct ad7417_softc {
        device_t                sc_dev;
        uint32_t                sc_addr;
        struct ad7417_sensor    *sc_sensors;
        int                     sc_nsensors;
        int                     init_done;
};
static device_method_t  ad7417_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         ad7417_probe),
        DEVMETHOD(device_attach,        ad7417_attach),
        DEVMETHOD_END
};

static driver_t ad7417_driver = {
        "ad7417",
        ad7417_methods,
        sizeof(struct ad7417_softc)
};

DRIVER_MODULE(ad7417, iicbus, ad7417_driver, 0, 0);
static MALLOC_DEFINE(M_AD7417, "ad7417", "Supply-Monitor AD7417");


static int
ad7417_write(device_t dev, uint32_t addr, uint8_t reg, uint8_t *buff, int len)
{
        unsigned char buf[4];
        int try = 0;

        struct iic_msg msg[] = {
                { addr, IIC_M_WR, 0, buf }
        };

        msg[0].len = len + 1;
        buf[0] = reg;
        memcpy(buf + 1, buff, len);

        for (;;)
        {
                if (iicbus_transfer(dev, msg, nitems(msg)) == 0)
                        return (0);

                if (++try > 5) {
                        device_printf(dev, "iicbus write failed\n");
                        return (-1);
                }
                pause("ad7417_write", hz);
        }
}

static int
ad7417_read_1(device_t dev, uint32_t addr, uint8_t reg, uint8_t *data)
{
        uint8_t buf[4];
        int err, try = 0;

        struct iic_msg msg[2] = {
            { addr, IIC_M_WR | IIC_M_NOSTOP, 1, &reg },
            { addr, IIC_M_RD, 1, buf },
        };

        for (;;)
        {
                err = iicbus_transfer(dev, msg, nitems(msg));
                if (err != 0)
                        goto retry;

                *data = *((uint8_t*)buf);
                return (0);
        retry:
                if (++try > 5) {
                        device_printf(dev, "iicbus read failed\n");
                        return (-1);
                }
                pause("ad7417_read_1", hz);
        }
}

static int
ad7417_read_2(device_t dev, uint32_t addr, uint8_t reg, uint16_t *data)
{
        uint8_t buf[4];
        int err, try = 0;

        struct iic_msg msg[2] = {
            { addr, IIC_M_WR | IIC_M_NOSTOP, 1, &reg },
            { addr, IIC_M_RD, 2, buf },
        };

        for (;;)
        {
                err = iicbus_transfer(dev, msg, nitems(msg));
                if (err != 0)
                        goto retry;

                *data = *((uint16_t*)buf);
                return (0);
        retry:
                if (++try > 5) {
                        device_printf(dev, "iicbus read failed\n");
                        return (-1);
                }
                pause("ad7417_read_2", hz);
        }
}

static int
ad7417_write_read(device_t dev, uint32_t addr, struct write_data out,
                  struct read_data *in)
{
        uint8_t buf[4];
        int err, try = 0;

        /* Do a combined write/read. */
        struct iic_msg msg[3] = {
            { addr, IIC_M_WR, 2, buf },
            { addr, IIC_M_WR | IIC_M_NOSTOP, 1, &in->reg },
            { addr, IIC_M_RD, 2, buf },
        };

        /* Prepare the write msg. */
        buf[0] = out.reg;
        buf[1] = out.val & 0xff;

        for (;;)
        {
                err = iicbus_transfer(dev, msg, nitems(msg));
                if (err != 0)
                        goto retry;

                in->val = *((uint16_t*)buf);
                return (0);
        retry:
                if (++try > 5) {
                        device_printf(dev, "iicbus write/read failed\n");
                        return (-1);
                }
                pause("ad7417_write_read", hz);
        }
}

static int
ad7417_init_adc(device_t dev, uint32_t addr)
{
        uint8_t buf;
        int err;
        struct ad7417_softc *sc;

        sc = device_get_softc(dev);

        adc741x_config = 0;
        /* Clear Config2 */
        buf = 0;

        err = ad7417_write(dev, addr, AD7417_CONFIG2, &buf, sizeof(buf));

         /* Read & cache Config1 */
        buf = 0;
        err = ad7417_write(dev, addr, AD7417_CONFIG, &buf, sizeof(buf));
        err = ad7417_read_1(dev, addr, AD7417_CONFIG, &buf);
        adc741x_config = (uint8_t)buf;

        /* Disable shutdown mode */
        adc741x_config &= 0xfe;
        buf = adc741x_config;
        err = ad7417_write(dev, addr, AD7417_CONFIG, &buf, sizeof(buf));
        if (err < 0)
                return (-1);

        sc->init_done = 1;

        return (0);

}
static int
ad7417_probe(device_t dev)
{
        const char  *name, *compatible;
        struct ad7417_softc *sc;

        name = ofw_bus_get_name(dev);
        compatible = ofw_bus_get_compat(dev);

        if (!name)
                return (ENXIO);

        if (strcmp(name, "supply-monitor") != 0 ||
            strcmp(compatible, "ad7417") != 0)
                return (ENXIO);

        sc = device_get_softc(dev);
        sc->sc_dev = dev;
        sc->sc_addr = iicbus_get_addr(dev);

        device_set_desc(dev, "Supply-Monitor AD7417");

        return (0);
}

/*
 * This function returns the number of sensors. If we call it the second time
 * and we have allocated memory for sc->sc_sensors, we fill in the properties.
 */
static int
ad7417_fill_sensor_prop(device_t dev)
{
        phandle_t child, node;
        struct ad7417_softc *sc;
        u_int id[10];
        char location[96];
        char type[32];
        int i = 0, j, len = 0, prop_len, prev_len = 0;

        sc = device_get_softc(dev);

        child = ofw_bus_get_node(dev);

        /* Fill the sensor location property. */
        prop_len = OF_getprop(child, "hwsensor-location", location,
                              sizeof(location));
        while (len < prop_len) {
                if (sc->sc_sensors != NULL)
                        strcpy(sc->sc_sensors[i].therm.name, location + len);
                prev_len = strlen(location + len) + 1;
                len += prev_len;
                i++;
        }
        if (sc->sc_sensors == NULL)
                return (i);

        /* Fill the sensor type property. */
        len = 0;
        i = 0;
        prev_len = 0;
        prop_len = OF_getprop(child, "hwsensor-type", type, sizeof(type));
        while (len < prop_len) {
                if (strcmp(type + len, "temperature") == 0)
                        sc->sc_sensors[i].type = ADC7417_TEMP_SENSOR;
                else
                        sc->sc_sensors[i].type = ADC7417_ADC_SENSOR;
                prev_len = strlen(type + len) + 1;
                len += prev_len;
                i++;
        }

        /* Fill the sensor id property. Taken from OF. */
        prop_len = OF_getprop(child, "hwsensor-id", id, sizeof(id));
        for (j = 0; j < i; j++)
                sc->sc_sensors[j].id = id[j];

        /* Fill the sensor zone property. Taken from OF. */
        prop_len = OF_getprop(child, "hwsensor-zone", id, sizeof(id));
        for (j = 0; j < i; j++)
                sc->sc_sensors[j].therm.zone = id[j];

        /* Some PowerMac's have the real location of the sensors on
           child nodes of the hwsensor-location node. Check for and
           fix the name if needed.
           This is needed to apply the below HACK with the diode.
        */
        j = 0;
        for (node = OF_child(child); node != 0; node = OF_peer(node)) {
            
            OF_getprop(node, "location", location, sizeof(location));
            strcpy(sc->sc_sensors[i].therm.name, location);
            j++; 
        }

        /* Finish setting up sensor properties */
        for (j = 0; j < i; j++) {
                sc->sc_sensors[j].dev = dev;
        
                /* HACK: Apple wired a random diode to the ADC line */
                if ((strstr(sc->sc_sensors[j].therm.name, "DIODE TEMP")
                    != NULL)
                    || (strstr(sc->sc_sensors[j].therm.name, "AD1") != NULL)) {
                        sc->sc_sensors[j].type = ADC7417_TEMP_SENSOR;
                        sc->sc_sensors[j].therm.read =
                            (int (*)(struct pmac_therm *))(ad7417_diode_read);
                } else {
                        sc->sc_sensors[j].therm.read =
                            (int (*)(struct pmac_therm *))(ad7417_sensor_read);
                }
                        
                if (sc->sc_sensors[j].type != ADC7417_TEMP_SENSOR)
                        continue;

                /* Make up some ranges */
                sc->sc_sensors[j].therm.target_temp = 500 + ZERO_C_TO_K;
                sc->sc_sensors[j].therm.max_temp = 900 + ZERO_C_TO_K;
                
                pmac_thermal_sensor_register(&sc->sc_sensors[j].therm);
        }

        return (i);
}

static int
ad7417_attach(device_t dev)
{
        struct ad7417_softc *sc;
        struct sysctl_oid *oid, *sensroot_oid;
        struct sysctl_ctx_list *ctx;
        char sysctl_name[32];
        int i, j;
        const char *unit;

        sc = device_get_softc(dev);

        sc->sc_nsensors = 0;

        /* Count the actual number of sensors. */
        sc->sc_nsensors = ad7417_fill_sensor_prop(dev);

        device_printf(dev, "%d sensors detected.\n", sc->sc_nsensors);

        if (sc->sc_nsensors == 0)
                device_printf(dev, "WARNING: No AD7417 sensors detected!\n");

        sc->sc_sensors = malloc (sc->sc_nsensors * sizeof(struct ad7417_sensor),
                                 M_AD7417, M_WAITOK | M_ZERO);

        ctx = device_get_sysctl_ctx(dev);
        sensroot_oid = SYSCTL_ADD_NODE(ctx,
            SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO, "sensor",
            CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "AD7417 Sensor Information");

        /* Now we can fill the properties into the allocated struct. */
        sc->sc_nsensors = ad7417_fill_sensor_prop(dev);

        /* Add sysctls for the sensors. */
        for (i = 0; i < sc->sc_nsensors; i++) {
                for (j = 0; j < strlen(sc->sc_sensors[i].therm.name); j++) {
                        sysctl_name[j] =
                            tolower(sc->sc_sensors[i].therm.name[j]);
                        if (isspace(sysctl_name[j]))
                                sysctl_name[j] = '_';
                }
                sysctl_name[j] = 0;

                oid = SYSCTL_ADD_NODE(ctx, SYSCTL_CHILDREN(sensroot_oid),
                    OID_AUTO, sysctl_name, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
                    "Sensor Information");

                if (sc->sc_sensors[i].type == ADC7417_TEMP_SENSOR) {
                        unit = "temp";
                } else {
                        unit = "volt";
                }
                /* I use i to pass the sensor id. */
                SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(oid), OID_AUTO,
                                unit, CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
                                dev, i, ad7417_sensor_sysctl,
                                sc->sc_sensors[i].type == ADC7417_TEMP_SENSOR ?
                                "IK" : "I",
                                sc->sc_sensors[i].type == ADC7417_TEMP_SENSOR ?
                                "sensor unit (C)" : "sensor unit (mV)");
        }
        /* Dump sensor location, ID & type. */
        if (bootverbose) {
                device_printf(dev, "Sensors\n");
                for (i = 0; i < sc->sc_nsensors; i++) {
                        device_printf(dev, "Location: %s ID: %d type: %d\n",
                                      sc->sc_sensors[i].therm.name,
                                      sc->sc_sensors[i].id,
                                      sc->sc_sensors[i].type);
                }
        }

        return (0);
}

static int
ad7417_get_temp(device_t dev, uint32_t addr, int *temp)
{
        uint16_t buf[2];
        uint16_t read;
        int err;

        err = ad7417_read_2(dev, addr, AD7417_TEMP, buf);

        if (err < 0)
                return (-1);

        read = *((int16_t*)buf);

        /* The ADC is 10 bit, the resolution is 0.25 C.
           The temperature is in tenth kelvin.
        */
        *temp = (((int16_t)(read & 0xffc0)) >> 6) * 25 / 10;
        return (0);
}

static int
ad7417_get_adc(device_t dev, uint32_t addr, unsigned int *value,
               uint8_t chan)
{
        uint8_t tmp;
        int err;
        struct write_data config;
        struct read_data data;

        tmp = chan << 5;
        config.reg = AD7417_CONFIG;
        data.reg = AD7417_ADC;
        data.val = 0;

        err = ad7417_read_1(dev, addr, AD7417_CONFIG, &config.val);

        config.val = (config.val & ~AD7417_CONFMASK) | (tmp & AD7417_CONFMASK);

        err = ad7417_write_read(dev, addr, config, &data);
        if (err < 0)
                return (-1);

        *value = ((uint32_t)data.val) >> 6;

        return (0);
}

static int
ad7417_diode_read(struct ad7417_sensor *sens)
{
        static int eeprom_read = 0;
        static cell_t eeprom[2][40];
        phandle_t eeprom_node;
        int rawval, diode_slope, diode_offset;
        int temp;

        if (!eeprom_read) {
                eeprom_node = OF_finddevice("/u3/i2c/cpuid@a0");
                OF_getprop(eeprom_node, "cpuid", eeprom[0], sizeof(eeprom[0]));
                eeprom_node = OF_finddevice("/u3/i2c/cpuid@a2");
                OF_getprop(eeprom_node, "cpuid", eeprom[1], sizeof(eeprom[1]));
                eeprom_read = 1;
        }

        rawval = ad7417_adc_read(sens);
        if (rawval < 0)
                return (-1);

        if (strstr(sens->therm.name, "CPU B") != NULL) {
                diode_slope = eeprom[1][0x11] >> 16;
                diode_offset = (int16_t)(eeprom[1][0x11] & 0xffff) << 12;
        } else {
                diode_slope = eeprom[0][0x11] >> 16;
                diode_offset = (int16_t)(eeprom[0][0x11] & 0xffff) << 12;
        }

        temp = (rawval*diode_slope + diode_offset) >> 2;
        temp = (10*(temp >> 16)) + ((10*(temp & 0xffff)) >> 16);
        
        return (temp + ZERO_C_TO_K);
}

static int
ad7417_adc_read(struct ad7417_sensor *sens)
{
        struct ad7417_softc *sc;
        uint8_t chan;
        int temp;

        sc = device_get_softc(sens->dev);

        switch (sens->id) {
        case 11:
        case 16:
                chan = 1;
                break;
        case 12:
        case 17:
                chan = 2;
                break;
        case 13:
        case 18:
                chan = 3;
                break;
        case 14:
        case 19:
                chan = 4;
                break;
        default:
                chan = 1;
        }

        if (ad7417_get_adc(sc->sc_dev, sc->sc_addr, &temp, chan) < 0)
                return (-1);

        return (temp);
}


static int
ad7417_sensor_read(struct ad7417_sensor *sens)
{
        struct ad7417_softc *sc;
        int temp;

        sc = device_get_softc(sens->dev);

        /* Init the ADC if not already done.*/
        if (!sc->init_done)
                if (ad7417_init_adc(sc->sc_dev, sc->sc_addr) < 0)
                        return (-1);

        if (sens->type == ADC7417_TEMP_SENSOR) {
                if (ad7417_get_temp(sc->sc_dev, sc->sc_addr, &temp) < 0)
                        return (-1);
                temp += ZERO_C_TO_K;
        } else {
                temp = ad7417_adc_read(sens);
        }
        return (temp);
}

static int
ad7417_sensor_sysctl(SYSCTL_HANDLER_ARGS)
{
        device_t dev;
        struct ad7417_softc *sc;
        struct ad7417_sensor *sens;
        int value = 0;
        int error;

        dev = arg1;
        sc = device_get_softc(dev);
        sens = &sc->sc_sensors[arg2];

        value = sens->therm.read(&sens->therm);
        if (value < 0)
                return (ENXIO);

        error = sysctl_handle_int(oidp, &value, 0, req);

        return (error);
}