/* $NetBSD: jh71x0_temp.c,v 1.1 2025/01/03 11:49:04 skrll Exp $ */

/*-
 * Copyright (c) 2025 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Nick Hudson
 *
 * 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: jh71x0_temp.c,v 1.1 2025/01/03 11:49:04 skrll Exp $");

#include <sys/param.h>

#include <dev/fdt/fdtvar.h>

#include <dev/sysmon/sysmonvar.h>

struct jh71x0_temp_softc {
        device_t                sc_dev;
        bus_space_tag_t         sc_bst;
        bus_space_handle_t      sc_bsh;
        int                     sc_phandle;

        struct sysmon_envsys *  sc_sme;
        envsys_data_t           sc_sensor;
};

#define RD4(sc, reg)                                                           \
    bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
#define WR4(sc, reg, val)                                                      \
    bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))

/* Register definitions */
#define JH71X0_TEMP             0x0000
#define JH71X0_TEMP_RSTN        __BIT(0)
#define JH71X0_TEMP_PD          __BIT(1)
#define JH71X0_TEMP_RUN         __BIT(2)
#define JH71X0_TEMP_DOUT_MASK   __BITS(27, 16)

/* DOUT to Celcius conversion constants */
#define JH71X0TEMP_Y1000        237500L
#define JH71X0TEMP_Z            4094L
#define JH71X0TEMP_K1000        81100L

/* Calculate the temperature in milli Celcius */
static int32_t
jh71x0_temp_get(struct jh71x0_temp_softc *sc)
{
        uint32_t temp = RD4(sc, JH71X0_TEMP);
        uint32_t dout = __SHIFTOUT(temp, JH71X0_TEMP_DOUT_MASK);

        return (dout * JH71X0TEMP_Y1000) / JH71X0TEMP_Z - JH71X0TEMP_K1000;
}

static void
jh71x0_temp_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
{
        struct jh71x0_temp_softc * const sc = sme->sme_cookie;

        // Convert milli Celcius to micro Kelvin
        sc->sc_sensor.value_cur = 273150000 + 1000 * jh71x0_temp_get(sc);
        sc->sc_sensor.state = ENVSYS_SVALID;
}

static void
jh71x0_temp_init(struct jh71x0_temp_softc *sc)
{
        /* Power down */
        WR4(sc, JH71X0_TEMP, JH71X0_TEMP_PD);
        delay(1);

        /* Power up with reset asserted */
        WR4(sc, JH71X0_TEMP, 0);
        delay(60);

        /* Deassert reset */
        WR4(sc, JH71X0_TEMP, JH71X0_TEMP_RSTN);
        delay(1);

        /* Start measuring */
        WR4(sc, JH71X0_TEMP, JH71X0_TEMP_RSTN | JH71X0_TEMP_RUN);
}

/* Compat string(s) */
static const struct device_compatible_entry compat_data[] = {
        { .compat = "starfive,jh7100-temp" },
        { .compat = "starfive,jh7110-temp" },
        DEVICE_COMPAT_EOL
};

static int
jh71x0_temp_match(device_t parent, cfdata_t cf, void *aux)
{
        struct fdt_attach_args * const faa = aux;

        return of_compatible_match(faa->faa_phandle, compat_data);
}

static void
jh71x0_temp_attach(device_t parent, device_t self, void *aux)
{
        struct jh71x0_temp_softc * const sc = device_private(self);
        struct fdt_attach_args * const faa = aux;
        const int phandle = faa->faa_phandle;
        bus_addr_t addr;
        bus_size_t size;
        int error;

        if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
                aprint_error(": couldn't get registers\n");
                return;
        }

        sc->sc_dev = self;
        sc->sc_phandle = phandle;
        sc->sc_bst = faa->faa_bst;

        error = bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh);
        if (error) {
                aprint_error(": couldn't map %#" PRIxBUSADDR ": %d", addr,
                    error);
                return;
        }

        const char *crs[] = { "bus", "sense" };
        for (size_t i = 0; i < __arraycount(crs); i++) {
                const char *cr = crs[i];

                error = fdtbus_clock_enable(phandle, cr, true);
                if (error) {
                        aprint_error(": couldn't enable clock '%s'\n", cr);
                        return;
                }
                struct fdtbus_reset * rst = fdtbus_reset_get(phandle, cr);
                if (rst == NULL) {
                        aprint_error(": couldn't get reset '%s'\n", cr);
                        return;
                }
                error = fdtbus_reset_deassert(rst);
                if (error) {
                        aprint_error(": couldn't de-assert reset '%s'\n", cr);
                        return;
                }
        }

        aprint_naive("\n");
        aprint_normal(": JH71x0 temperature sensor\n");

        jh71x0_temp_init(sc);

        sc->sc_sme = sysmon_envsys_create();
        /* Initialize sensor data. */
        sc->sc_sensor.units = ENVSYS_STEMP;
        sc->sc_sensor.state = ENVSYS_SINVALID;
        (void)strlcpy(sc->sc_sensor.desc, device_xname(self),
            sizeof(sc->sc_sensor.desc));
        if (sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor)) {
                sysmon_envsys_destroy(sc->sc_sme);
                return;
        }

        /* Hook into system monitor. */
        sc->sc_sme->sme_name = device_xname(self);
        sc->sc_sme->sme_cookie = sc;
        sc->sc_sme->sme_refresh = jh71x0_temp_refresh;

        if (sysmon_envsys_register(sc->sc_sme)) {
                aprint_error_dev(self, "unable to register with sysmon\n");
                sysmon_envsys_destroy(sc->sc_sme);
        }
}

CFATTACH_DECL_NEW(jh71x0_temp, sizeof(struct jh71x0_temp_softc),
        jh71x0_temp_match, jh71x0_temp_attach, NULL, NULL);