/*      $OpenBSD: amltemp.c,v 1.2 2021/10/24 17:52:26 mpi Exp $ */
/*
 * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/sensors.h>

#include <machine/intr.h>
#include <machine/bus.h>
#include <machine/fdt.h>

#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_clock.h>
#include <dev/ofw/ofw_misc.h>
#include <dev/ofw/ofw_thermal.h>
#include <dev/ofw/fdt.h>

/* Calibration */
#define TS_CALIB_VALID_MASK     0x8c000000
#define TS_CALIB_SIGN_MASK      0x00008000
#define TS_CALIB_VALUE_MASK     0x000003ff

/* Registers */
#define TS_CFG_REG1     0x01
#define  TS_CFG_REG1_ANA_EN_VCM (1 << 10)
#define  TS_CFG_REG1_ANA_EN_VBG (1 << 9)
#define  TS_CFG_REG1_FILTER_EN  (1 << 5)
#define  TS_CFG_REG1_DEM_EN     (1 << 3)
#define  TS_CFG_REG1_ANA_CH_SEL 3
#define TS_STAT0        0x10
#define  TS_STAT0_CODE_MASK     0xffff

#define HREAD4(sc, reg)                                                 \
        (bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg) << 2))
#define HWRITE4(sc, reg, val)                                           \
        bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, (reg) << 2, (val))
#define HSET4(sc, reg, bits)                                            \
        HWRITE4((sc), (reg), HREAD4((sc), (reg)) | (bits))
#define HCLR4(sc, reg, bits)                                            \
        HWRITE4((sc), (reg), HREAD4((sc), (reg)) & ~(bits))

struct amltemp_softc {
        struct device           sc_dev;
        bus_space_tag_t         sc_iot;
        bus_space_handle_t      sc_ioh;

        int                     sc_node;
        int32_t                 sc_calib;

        struct ksensor          sc_sensor;
        struct ksensordev       sc_sensordev;

        struct thermal_sensor   sc_ts;
};

int     amltemp_match(struct device *, void *, void *);
void    amltemp_attach(struct device *, struct device *, void *);

const struct cfattach   amltemp_ca = {
        sizeof (struct amltemp_softc), amltemp_match, amltemp_attach
};

struct cfdriver amltemp_cd = {
        NULL, "amltemp", DV_DULL
};

void    amltemp_attachhook(struct device *);
int32_t amltemp_calc_temp(struct amltemp_softc *, int32_t);
void    amltemp_refresh_sensors(void *);
int32_t amltemp_get_temperature(void *, uint32_t *);

int
amltemp_match(struct device *parent, void *match, void *aux)
{
        struct fdt_attach_args *faa = aux;

        return OF_is_compatible(faa->fa_node, "amlogic,g12a-thermal");
}

void
amltemp_attach(struct device *parent, struct device *self, void *aux)
{
        struct amltemp_softc *sc = (struct amltemp_softc *)self;
        struct fdt_attach_args *faa = aux;

        if (faa->fa_nreg < 1) {
                printf(": no registers\n");
                return;
        }

        sc->sc_iot = faa->fa_iot;
        if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
            faa->fa_reg[0].size, 0, &sc->sc_ioh)) {
                printf(": can't map registers\n");
                return;
        }

        sc->sc_node = faa->fa_node;
        printf("\n");

        config_mountroot(self, amltemp_attachhook);
}

void
amltemp_attachhook(struct device *self)
{
        struct amltemp_softc *sc = (struct amltemp_softc *)self;
        struct regmap *rm;
        bus_addr_t offset;
        const char *name;
        uint32_t ao_secure;

        if (OF_is_compatible(sc->sc_node, "amlogic,g12a-cpu-thermal")) {
                offset = 0x128;
                name = "CPU";
        } else if (OF_is_compatible(sc->sc_node, "amlogic,g12a-ddr-thermal")) {
                offset = 0x0f0;
                name = "DDR";
        } else {
                printf("%s: unknown sensor\n", sc->sc_dev.dv_xname);
                return;
        }

        /* Extract calibration value. */
        ao_secure = OF_getpropint(sc->sc_node, "amlogic,ao-secure", 0);
        rm = regmap_byphandle(ao_secure);
        if (rm == NULL) {
                printf("%s: no calibration info\n", sc->sc_dev.dv_xname);
                return;
        }
        sc->sc_calib = regmap_read_4(rm, offset);
        if ((sc->sc_calib & TS_CALIB_VALID_MASK) == 0) {
                printf("%s: invalid calibration\n", sc->sc_dev.dv_xname);
                return;
        }
        if (sc->sc_calib & TS_CALIB_SIGN_MASK)
                sc->sc_calib = ~(sc->sc_calib & TS_CALIB_VALUE_MASK) + 1;
        else
                sc->sc_calib = (sc->sc_calib & TS_CALIB_VALUE_MASK);

        /* Enable hardware. */
        clock_enable_all(sc->sc_node);
        HSET4(sc, TS_CFG_REG1, TS_CFG_REG1_ANA_EN_VCM |
            TS_CFG_REG1_ANA_EN_VBG | TS_CFG_REG1_FILTER_EN |
            TS_CFG_REG1_DEM_EN | TS_CFG_REG1_ANA_CH_SEL);

        /* Register sensor. */
        strlcpy(sc->sc_sensordev.xname, sc->sc_dev.dv_xname,
            sizeof(sc->sc_sensordev.xname));
        strlcpy(sc->sc_sensor.desc, name, sizeof(sc->sc_sensor.desc));
        sc->sc_sensor.type = SENSOR_TEMP;
        sc->sc_sensor.flags = SENSOR_FINVALID;
        sensor_attach(&sc->sc_sensordev, &sc->sc_sensor);
        sensordev_install(&sc->sc_sensordev);
        sensor_task_register(sc, amltemp_refresh_sensors, 5);

        sc->sc_ts.ts_node = sc->sc_node;
        sc->sc_ts.ts_cookie = sc;
        sc->sc_ts.ts_get_temperature = amltemp_get_temperature;
        thermal_sensor_register(&sc->sc_ts);
}

int32_t
amltemp_calc_temp(struct amltemp_softc *sc, int32_t code)
{
        const uint32_t A = 9411;
        const uint32_t B = 3159;
        const uint32_t m = 424;
        const uint32_t n = 324;
        int64_t tmp1, tmp2;
        
        tmp1 = (code * m) / 100;
        tmp2 = (code * n) / 100;
        tmp1 = (tmp1 * (1 << 16)) / ((1 << 16) + tmp2);
        tmp1 = ((tmp1 + sc->sc_calib) * A) / (1 << 16);
        return (tmp1 - B) * 100;
}

void
amltemp_refresh_sensors(void *arg)
{
        struct amltemp_softc *sc = arg;
        int32_t code, temp;

        code = HREAD4(sc, TS_STAT0);
        temp = amltemp_calc_temp(sc, code & TS_STAT0_CODE_MASK);

        sc->sc_sensor.value = 273150000 + 1000 * temp;
        sc->sc_sensor.flags &= ~SENSOR_FINVALID;
}

int32_t
amltemp_get_temperature(void *cookie, uint32_t *cells)
{
        struct amltemp_softc *sc = cookie;
        int32_t code;

        code = HREAD4(sc, TS_STAT0);
        return amltemp_calc_temp(sc, code & TS_STAT0_CODE_MASK);
}