/*      $OpenBSD: pcf85063.c,v 1.3 2022/10/12 13:39:50 kettenis Exp $   */

/*
 * Copyright (c) 2005 Kimihiro Nonaka
 * Copyright (c) 2016, 2021 Mark Kettenis
 * 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 WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
 * 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/systm.h>
#include <sys/device.h>

#include <dev/clock_subr.h>

#include <dev/i2c/i2cvar.h>

/*
 * PCF85063A/TP Real-Time Clock
 */

#define PCF85063_CONTROL1       0x00
#define PCF85063_SECONDS        0x04
#define PCF85063_MINUTES        0x05
#define PCF85063_HOURS          0x06
#define PCF85063_DAY            0x07
#define PCF85063_WDAY           0x08
#define PCF85063_MONTH          0x09
#define PCF85063_YEAR           0x0a

#define PCF85063_NRTC_REGS      7

/*
 * Bit definitions.
 */
#define PCF85063_CONTROL1_12_24 (1 << 1)
#define PCF85063_CONTROL1_STOP  (1 << 5)
#define PCF85063_SECONDS_MASK   0x7f
#define PCF85063_SECONDS_OS     (1 << 7)
#define PCF85063_MINUTES_MASK   0x7f
#define PCF85063_HOURS_12HRS_PM (1 << 5)        /* If 12 hr mode, set = PM */
#define PCF85063_HOURS_12MASK   0x1f
#define PCF85063_HOURS_24MASK   0x3f
#define PCF85063_DAY_MASK       0x3f
#define PCF85063_WDAY_MASK      0x07
#define PCF85063_MONTH_MASK     0x1f

struct pcyrtc_softc {
        struct device sc_dev;
        i2c_tag_t sc_tag;
        int sc_address;
        struct todr_chip_handle sc_todr;
};

int pcyrtc_match(struct device *, void *, void *);
void pcyrtc_attach(struct device *, struct device *, void *);

const struct cfattach pcyrtc_ca = {
        sizeof(struct pcyrtc_softc), pcyrtc_match, pcyrtc_attach
};

struct cfdriver pcyrtc_cd = {
        NULL, "pcyrtc", DV_DULL
};

uint8_t pcyrtc_reg_read(struct pcyrtc_softc *, int);
void pcyrtc_reg_write(struct pcyrtc_softc *, int, uint8_t);
int pcyrtc_clock_read(struct pcyrtc_softc *, struct clock_ymdhms *);
int pcyrtc_clock_write(struct pcyrtc_softc *, struct clock_ymdhms *);
int pcyrtc_gettime(struct todr_chip_handle *, struct timeval *);
int pcyrtc_settime(struct todr_chip_handle *, struct timeval *);

int
pcyrtc_match(struct device *parent, void *v, void *arg)
{
        struct i2c_attach_args *ia = arg;

        if (strcmp(ia->ia_name, "nxp,pcf85063a") == 0)
                return (1);

        return (0);
}

void
pcyrtc_attach(struct device *parent, struct device *self, void *arg)
{
        struct pcyrtc_softc *sc = (struct pcyrtc_softc *)self;
        struct i2c_attach_args *ia = arg;
        uint8_t reg;

        sc->sc_tag = ia->ia_tag;
        sc->sc_address = ia->ia_addr;

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

        /*
         * Switch to 24 hour mode.
         */
        reg = pcyrtc_reg_read(sc, PCF85063_CONTROL1);
        reg &= ~PCF85063_CONTROL1_12_24;
        reg &= ~PCF85063_CONTROL1_STOP;
        pcyrtc_reg_write(sc, PCF85063_CONTROL1, reg);

        printf("\n");
}

int
pcyrtc_gettime(struct todr_chip_handle *ch, struct timeval *tv)
{
        struct pcyrtc_softc *sc = ch->cookie;
        struct clock_ymdhms dt;

        memset(&dt, 0, sizeof(dt));
        if (pcyrtc_clock_read(sc, &dt) == 0)
                return (-1);

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

int
pcyrtc_settime(struct todr_chip_handle *ch, struct timeval *tv)
{
        struct pcyrtc_softc *sc = ch->cookie;
        struct clock_ymdhms dt;
        uint8_t reg;

        clock_secs_to_ymdhms(tv->tv_sec, &dt);
        if (pcyrtc_clock_write(sc, &dt) == 0)
                return (-1);

        /* Clear OS flag. */
        reg = pcyrtc_reg_read(sc, PCF85063_SECONDS);
        if (reg & PCF85063_SECONDS_OS) {
                reg &= ~PCF85063_SECONDS_OS;
                pcyrtc_reg_write(sc, PCF85063_SECONDS, reg);
        }

        return (0);
}

uint8_t
pcyrtc_reg_read(struct pcyrtc_softc *sc, int reg)
{
        uint8_t cmd = reg;
        uint8_t val;

        iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
        if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_address,
            NULL, 0, &cmd, sizeof cmd, I2C_F_POLL) ||
            iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_address,
            NULL, 0, &val, sizeof val, I2C_F_POLL)) {
                iic_release_bus(sc->sc_tag, I2C_F_POLL);
                printf("%s: pcyrtc_reg_read: failed to read reg%d\n",
                    sc->sc_dev.dv_xname, reg);
                return 0;
        }
        iic_release_bus(sc->sc_tag, I2C_F_POLL);
        return val;
}

void
pcyrtc_reg_write(struct pcyrtc_softc *sc, int reg, uint8_t val)
{
        uint8_t cmd = reg;

        iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
        if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_address,
            &cmd, sizeof cmd, &val, sizeof val, I2C_F_POLL)) {
                iic_release_bus(sc->sc_tag, I2C_F_POLL);
                printf("%s: pcyrtc_reg_write: failed to write reg%d\n",
                    sc->sc_dev.dv_xname, reg);
                return;
        }
        iic_release_bus(sc->sc_tag, I2C_F_POLL);
}

int
pcyrtc_clock_read(struct pcyrtc_softc *sc, struct clock_ymdhms *dt)
{
        uint8_t regs[PCF85063_NRTC_REGS];
        uint8_t cmd = PCF85063_SECONDS;

        iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
        if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_address,
            &cmd, sizeof cmd, regs, PCF85063_NRTC_REGS, I2C_F_POLL)) {
                iic_release_bus(sc->sc_tag, I2C_F_POLL);
                printf("%s: pcyrtc_clock_read: failed to read rtc\n",
                    sc->sc_dev.dv_xname);
                return (0);
        }
        iic_release_bus(sc->sc_tag, I2C_F_POLL);

        /*
         * Convert the PCF85063's register values into something useable
         */
        dt->dt_sec = FROMBCD(regs[0] & PCF85063_SECONDS_MASK);
        dt->dt_min = FROMBCD(regs[1] & PCF85063_MINUTES_MASK);
        dt->dt_hour = FROMBCD(regs[2] & PCF85063_HOURS_24MASK);
        dt->dt_day = FROMBCD(regs[3] & PCF85063_DAY_MASK);
        dt->dt_mon = FROMBCD(regs[5] & PCF85063_MONTH_MASK);
        dt->dt_year = FROMBCD(regs[6]) + 2000;

        if (regs[0] & PCF85063_SECONDS_OS)
                return (0);

        return (1);
}

int
pcyrtc_clock_write(struct pcyrtc_softc *sc, struct clock_ymdhms *dt)
{
        uint8_t regs[PCF85063_NRTC_REGS];
        uint8_t cmd = PCF85063_SECONDS;

        /*
         * Convert our time representation into something the PCF85063
         * can understand.
         */
        regs[0] = TOBCD(dt->dt_sec);
        regs[1] = TOBCD(dt->dt_min);
        regs[2] = TOBCD(dt->dt_hour);
        regs[3] = TOBCD(dt->dt_day);
        regs[4] = TOBCD(dt->dt_wday);
        regs[5] = TOBCD(dt->dt_mon);
        regs[6] = TOBCD(dt->dt_year - 2000);

        iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
        if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_address,
            &cmd, sizeof cmd, regs, PCF85063_NRTC_REGS, I2C_F_POLL)) {
                iic_release_bus(sc->sc_tag, I2C_F_POLL);
                printf("%s: pcyrtc_clock_write: failed to write rtc\n",
                    sc->sc_dev.dv_xname);
                return (0);
        }
        iic_release_bus(sc->sc_tag, I2C_F_POLL);
        return (1);
}