/*      $OpenBSD: acrtc.c,v 1.6 2022/10/17 19:09:46 kettenis Exp $      */
/*
 * Copyright (c) 2017 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/malloc.h>

#include <dev/fdt/rsbvar.h>

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

#include <dev/clock_subr.h>

#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)

#define CK32K_OUT_CTRL1                 0xc1
#define  CK32K_OUT_CTRL_PRE_DIV_MASK    (0x7 << 5)
#define  CK32K_OUT_CTRL_PRE_DIV_32K     (0x7 << 5)
#define  CK32K_OUT_CTRL_MUX_SEL_MASK    (1 << 4)
#define  CK32K_OUT_CTRL_MUX_SEL_32K     (0 << 4)
#define  CK32K_OUT_CTRL_POST_DIV_MASK   (0x7 << 1)
#define  CK32K_OUT_CTRL_POST_DIV_32K    (0x0 << 1)
#define  CK32K_OUT_CTRL_ENA             (1 << 0)
#define RTC_CTRL                        0xc7
#define  RTC_CTRL_12H_24H_MODE          (1 << 0)
#define RTC_SEC                         0xc8
#define  RTC_SEC_MASK                   (0x7f << 0)
#define RTC_MIN                         0xc9
#define  RTC_MIN_MASK                   (0x7f << 0)
#define RTC_HOU                         0xca
#define  RTC_HOU_MASK                   (0x3f << 0)
#define RTC_WEE                         0xcb
#define  RTC_WEE_MASK                   (0x07 << 0)
#define RTC_DAY                         0xcc
#define  RTC_DAY_MASK                   (0x3f << 0)
#define RTC_MON                         0xcd
#define  RTC_MON_MASK                   (0x1f << 0)
#define RTC_YEA                         0xce
#define  RTC_YEA_LEAP_YEAR              (1 << 15)
#define  RTC_YEA_MASK                   (0xff << 0)
#define RTC_UPD_TRIG                    0xcf
#define  RTC_UPD_TRIG_UPDATE            (1 << 15)

struct acrtc_softc {
        struct device           sc_dev;
        void                    *sc_cookie;
        uint16_t                sc_rta;

        struct todr_chip_handle sc_todr;
        struct clock_device     sc_cd;
};

int     acrtc_match(struct device *, void *, void *);
void    acrtc_attach(struct device *, struct device *, void *);

const struct cfattach acrtc_ca = {
        sizeof(struct acrtc_softc), acrtc_match, acrtc_attach
};

struct cfdriver acrtc_cd = {
        NULL, "acrtc", DV_DULL
};

int     acrtc_clock_read(struct acrtc_softc *, struct clock_ymdhms *);
int     acrtc_clock_write(struct acrtc_softc *, struct clock_ymdhms *);
int     acrtc_gettime(struct todr_chip_handle *, struct timeval *);
int     acrtc_settime(struct todr_chip_handle *, struct timeval *);

void    acrtc_ck32k_enable(void *, uint32_t *, int);

int
acrtc_match(struct device *parent, void *match, void *aux)
{
        struct rsb_attach_args *ra = aux;

        if (strcmp(ra->ra_name, "x-powers,ac100") == 0)
                return 1;
        return 0;
}

void
acrtc_attach(struct device *parent, struct device *self, void *aux)
{
        struct acrtc_softc *sc = (struct acrtc_softc *)self;
        struct rsb_attach_args *ra = aux;
        int node;

        sc->sc_cookie = ra->ra_cookie;
        sc->sc_rta = ra->ra_rta;

        printf("\n");

        sc->sc_todr.cookie = sc;
        sc->sc_todr.todr_gettime = acrtc_gettime;
        sc->sc_todr.todr_settime = acrtc_settime;
        sc->sc_todr.todr_quality = 1000;
        todr_attach(&sc->sc_todr);

        node = OF_getnodebyname(ra->ra_node, "rtc");
        if (node == 0)
                return;

        sc->sc_cd.cd_node = node;
        sc->sc_cd.cd_cookie = sc;
        sc->sc_cd.cd_enable = acrtc_ck32k_enable;
        clock_register(&sc->sc_cd);
}

static inline uint16_t
acrtc_read_reg(struct acrtc_softc *sc, uint8_t reg)
{
        return rsb_read_2(sc->sc_cookie, sc->sc_rta, reg);
}

static inline void
acrtc_write_reg(struct acrtc_softc *sc, uint8_t reg, uint16_t value)
{
        rsb_write_2(sc->sc_cookie, sc->sc_rta, reg, value);
}

int
acrtc_gettime(struct todr_chip_handle *handle, struct timeval *tv)
{
        struct acrtc_softc *sc = handle->cookie;
        struct clock_ymdhms dt;
        int error;

        error = acrtc_clock_read(sc, &dt);
        if (error)
                return error;

        if (dt.dt_sec > 59 || dt.dt_min > 59 || dt.dt_hour > 23 ||
            dt.dt_day > 31 || dt.dt_day == 0 ||
            dt.dt_mon > 12 || dt.dt_mon == 0 ||
            dt.dt_year < POSIX_BASE_YEAR)
                return EINVAL;

        tv->tv_sec = clock_ymdhms_to_secs(&dt);
        tv->tv_usec = 0;
        return 0;
}

int
acrtc_settime(struct todr_chip_handle *handle, struct timeval *tv)
{
        struct acrtc_softc *sc = handle->cookie;
        struct clock_ymdhms dt;

        clock_secs_to_ymdhms(tv->tv_sec, &dt);

        return acrtc_clock_write(sc, &dt);
}

int
acrtc_clock_read(struct acrtc_softc *sc, struct clock_ymdhms *dt)
{
        uint16_t ctrl;

        dt->dt_sec = FROMBCD(acrtc_read_reg(sc, RTC_SEC) & RTC_SEC_MASK);
        dt->dt_min = FROMBCD(acrtc_read_reg(sc, RTC_MIN) & RTC_MIN_MASK);
        dt->dt_hour = FROMBCD(acrtc_read_reg(sc, RTC_HOU) & RTC_HOU_MASK);
        dt->dt_day = FROMBCD(acrtc_read_reg(sc, RTC_DAY) & RTC_DAY_MASK);
        dt->dt_mon = FROMBCD(acrtc_read_reg(sc, RTC_MON) & RTC_MON_MASK);
        dt->dt_year = FROMBCD(acrtc_read_reg(sc, RTC_YEA) & RTC_YEA_MASK);
        dt->dt_year += 2000;

#ifdef DEBUG
        printf("%02d/%02d/%04d %02d:%02d:%0d\n", dt->dt_day, dt->dt_mon,
            dt->dt_year, dt->dt_hour, dt->dt_min, dt->dt_sec);
#endif

        /* Consider the time to be invalid if the clock is in 12H mode. */
        ctrl = acrtc_read_reg(sc, RTC_CTRL);
        if ((ctrl & RTC_CTRL_12H_24H_MODE) == 0)
                return EINVAL;

        return 0;
}

int
acrtc_clock_write(struct acrtc_softc *sc, struct clock_ymdhms *dt)
{
        uint16_t leap = isleap(dt->dt_year) ? RTC_YEA_LEAP_YEAR : 0;

        acrtc_write_reg(sc, RTC_SEC, TOBCD(dt->dt_sec));
        acrtc_write_reg(sc, RTC_MIN, TOBCD(dt->dt_min));
        acrtc_write_reg(sc, RTC_HOU, TOBCD(dt->dt_hour));
        acrtc_write_reg(sc, RTC_WEE, TOBCD(dt->dt_wday));
        acrtc_write_reg(sc, RTC_DAY, TOBCD(dt->dt_day));
        acrtc_write_reg(sc, RTC_MON, TOBCD(dt->dt_mon));
        acrtc_write_reg(sc, RTC_YEA, TOBCD(dt->dt_year - 2000) | leap);
        acrtc_write_reg(sc, RTC_UPD_TRIG, RTC_UPD_TRIG_UPDATE);

        /* Switch to 24H mode to indicate the time is now valid. */
        acrtc_write_reg(sc, RTC_CTRL, RTC_CTRL_12H_24H_MODE);

        return 0;
}

void
acrtc_ck32k_enable(void *cookie, uint32_t *cells, int on)
{
        struct acrtc_softc *sc = cookie;
        uint32_t idx = cells[0];
        uint16_t reg;

        reg = acrtc_read_reg(sc, CK32K_OUT_CTRL1 + idx);
        reg &= ~CK32K_OUT_CTRL_PRE_DIV_MASK;
        reg &= ~CK32K_OUT_CTRL_MUX_SEL_MASK;
        reg &= ~CK32K_OUT_CTRL_POST_DIV_MASK;
        reg |= CK32K_OUT_CTRL_PRE_DIV_32K;
        reg |= CK32K_OUT_CTRL_MUX_SEL_32K;
        reg |= CK32K_OUT_CTRL_POST_DIV_32K;
        if (on)
                reg |= CK32K_OUT_CTRL_ENA;
        else
                reg &= ~CK32K_OUT_CTRL_ENA;
        acrtc_write_reg(sc, CK32K_OUT_CTRL1 + idx, reg);
}