/*-
 * Copyright (c) 2017 Hiroki Mori.  All rights reserved.
 * Copyright (c) 2017 Ian Lepore.  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 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.
 *
 * This code base on isl12xx.c
 */

#include <sys/cdefs.h>
/*
 * Driver for realtime clock HAOYU HYM8563
 */

#include "opt_platform.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/clock.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>

#if defined(FDT)
#if !defined(__powerpc__)
#include <dev/clk/clk.h>
#endif
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#endif

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

#include "clock_if.h"
#include "iicbus_if.h"

/* Registers */
#define HYM8563_CTRL1           0x00
#define  HYM8563_CTRL1_TEST             (1 << 7)
#define  HYM8563_CTRL1_STOP             (1 << 5)
#define  HYM8563_CTRL1_TESTC            (1 << 3)

#define HYM8563_CTRL2           0x01
#define  HYM8563_CTRL2_TI_TP            (1 << 4)
#define  HYM8563_CTRL2_AF               (1 << 3)
#define  HYM8563_CTRL2_TF               (1 << 2)
#define  HYM8563_CTRL2_AIE              (1 << 1)
#define  HYM8563_CTRL2_TIE              (1 << 0)

#define HYM8563_SEC             0x02    /* plus battery low bit */
#define  HYM8563_SEC_VL                 (1 << 7)

#define HYM8563_MIN             0x03
#define HYM8563_HOUR            0x04
#define HYM8563_DAY             0x05
#define HYM8563_WEEKDAY         0x06
#define HYM8563_MONTH           0x07    /* plus 1 bit for century */
#define  HYM8563_MONTH_CENTURY          (1 << 7)
#define HYM8563_YEAR            0x08

#define HYM8563_CLKOUT          0x0D
#define  HYM8563_CLKOUT_ENABLE  (1 << 7)
#define  HYM8563_CLKOUT_32768   0
#define  HYM8563_CLKOUT_1024    1
#define  HYM8563_CLKOUT_32      2
#define  HYM8563_CLKOUT_1       3
#define  HYM8563_CLKOUT_MASK    3

struct hym8563_softc {
        device_t                        dev;
        struct intr_config_hook         init_hook;
};

#if defined(FDT)
#if !defined(__powerpc__)
/* Clock class and method */
struct hym8563_clk_sc {
        device_t                base_dev;
};
#endif


static struct ofw_compat_data compat_data[] = {
        {"haoyu,hym8563", 1},
        {NULL,           0},
};
#endif


static inline int
hym8563_read_buf(device_t dev, uint8_t reg, uint8_t *buf, uint16_t buflen)
{

        return (iicdev_readfrom(dev, reg, buf, buflen, IIC_WAIT));
}

static inline int
hym8563_write_buf(device_t dev, uint8_t reg, uint8_t *buf,  uint16_t buflen)
{

        return (iicdev_writeto(dev, reg, buf, buflen, IIC_WAIT));
}

static inline int
hym8563_read_1(device_t dev, uint8_t reg, uint8_t *data)
{

        return (iicdev_readfrom(dev, reg, data, 1, IIC_WAIT));
}

static inline int
hym8563_write_1(device_t dev, uint8_t reg, uint8_t val)
{

        return (iicdev_writeto(dev, reg, &val, 1, IIC_WAIT));
}

#if defined(FDT) && !defined(__powerpc__)
static int
hym8563_clk_set_gate(struct clknode *clk, bool enable)
{
        struct hym8563_clk_sc *sc;
        uint8_t val;
        int rv;

        sc = clknode_get_softc(clk);

        rv = hym8563_read_1(sc->base_dev, HYM8563_CLKOUT, &val);
        if (rv != 0) {
                device_printf(sc->base_dev,
                    "Cannot read CLKOUT registers: %d\n", rv);
                return (rv);
        }
        if (enable)
                val |= HYM8563_CLKOUT_ENABLE;
        else
                val &= ~HYM8563_CLKOUT_ENABLE;
        hym8563_write_1(sc->base_dev, HYM8563_CLKOUT, val);
        if (rv != 0) {
                device_printf(sc->base_dev,
                    "Cannot write CLKOUT registers: %d\n", rv);
                return (rv);
        }
        return (0);
}

static int
hym8563_clk_recalc(struct clknode *clk, uint64_t *freq)
{
        struct hym8563_clk_sc *sc;
        uint8_t val;
        int rv;

        sc = clknode_get_softc(clk);

        rv = hym8563_read_1(sc->base_dev, HYM8563_CLKOUT, &val);
        if (rv != 0) {
                device_printf(sc->base_dev,
                    "Cannot read CLKOUT registers: %d\n", rv);
                return (rv);
        }

        switch (val & HYM8563_CLKOUT_MASK) {
        case HYM8563_CLKOUT_32768:
                *freq = 32768;
                break;
        case HYM8563_CLKOUT_1024:
                *freq = 1024;
                break;
        case HYM8563_CLKOUT_32:
                *freq = 32;
                break;
        case HYM8563_CLKOUT_1:
                *freq = 1;
                break;
        default:
                return (EINVAL);
        }
        return (0);
}
static int
hym8563_clk_set(struct clknode *clk, uint64_t fparent, uint64_t *fout,
    int flags, int *stop)
{
        struct hym8563_clk_sc *sc;
        uint8_t val, tmp;
        int rv;

        sc = clknode_get_softc(clk);

        switch (*fout) {
        case 32768:
                tmp = HYM8563_CLKOUT_32768;
                break;
        case 1024:
                tmp = HYM8563_CLKOUT_1024;
                break;
        case 32:
                tmp = HYM8563_CLKOUT_32;
                break;
        case 1:
                tmp = HYM8563_CLKOUT_1;
                break;
        default:
                *stop = 1;
                return (EINVAL);
        }

        rv = hym8563_read_1(sc->base_dev, HYM8563_CLKOUT, &val);
        if (rv != 0) {
                device_printf(sc->base_dev,
                    "Cannot read CLKOUT registers: %d\n", rv);
                return (rv);
        }

        val &= ~HYM8563_CLKOUT_MASK;
        val |= tmp;
        rv = hym8563_write_1(sc->base_dev, HYM8563_CLKOUT, val);
        if (rv != 0) {
                device_printf(sc->base_dev,
                    "Cannot write CLKOUT registers: %d\n", rv);
                return (rv);
        }

        return (0);
}

static clknode_method_t hym8563_clk_clknode_methods[] = {
        CLKNODEMETHOD(clknode_recalc_freq,      hym8563_clk_recalc),
        CLKNODEMETHOD(clknode_set_freq,         hym8563_clk_set),
        CLKNODEMETHOD(clknode_set_gate,         hym8563_clk_set_gate),
        CLKNODEMETHOD_END
};

DEFINE_CLASS_1(hym8563_clk_clknode, hym8563_clk_clknode_class,
    hym8563_clk_clknode_methods, sizeof(struct hym8563_clk_sc),
    clknode_class);


static int
hym8563_attach_clocks(struct hym8563_softc *sc)
{
        struct clkdom *clkdom;
        struct clknode_init_def clkidef;
        struct clknode *clk;
        struct hym8563_clk_sc *clksc;
        const char **clknames;
        phandle_t node;
        int nclks, rv;

        node = ofw_bus_get_node(sc->dev);

        /* clock-output-names are optional. Could use them for clkidef.name. */
        nclks = ofw_bus_string_list_to_array(node, "clock-output-names",
            &clknames);

        clkdom = clkdom_create(sc->dev);

        memset(&clkidef, 0, sizeof(clkidef));
        clkidef.id = 1;
        clkidef.name = (nclks == 1) ? clknames[0] : "hym8563-clkout";
        clk = clknode_create(clkdom, &hym8563_clk_clknode_class, &clkidef);
        if (clk == NULL) {
                device_printf(sc->dev, "Cannot create '%s'.\n", clkidef.name);
                return (ENXIO);
        }
        clksc = clknode_get_softc(clk);
        clksc->base_dev = sc->dev;
        clknode_register(clkdom, clk);

        rv = clkdom_finit(clkdom);
        if (rv != 0) {
                device_printf(sc->dev, "Cannot finalize clkdom initialization: "
                    "%d\n", rv);
                return (ENXIO);
        }

        if (bootverbose)
                clkdom_dump(clkdom);

        return (0);
}
#endif

static int
hym8563_gettime(device_t dev, struct timespec *ts)
{
        struct hym8563_softc    *sc;
        struct bcd_clocktime     bct;
        uint8_t                  buf[7];
        int                      rv;

        sc = device_get_softc(dev);

        /* Read all RTC data */
        rv = hym8563_read_buf(sc->dev, HYM8563_SEC, buf, sizeof(buf));
        if (rv != 0) {
                device_printf(sc->dev, "Cannot read time registers: %d\n", rv);
                return (rv);
        }

        /* Check for low voltage flag */
        if (buf[0] & HYM8563_SEC_VL)
        {
                device_printf(sc->dev,
                    "WARNING: RTC battery failed; time is invalid\n");
                return (EINVAL);
        }

        bzero(&bct, sizeof(bct));
        bct.sec  = buf[0] & 0x7F;
        bct.min  = buf[1] & 0x7F;
        bct.hour = buf[2] & 0x3f;
        bct.day  = buf[3] & 0x3f;
        /* buf[4] is  weekday */
        bct.mon  = buf[5] & 0x1f;
        bct.year = buf[6] & 0xff;
        if (buf[5] & HYM8563_MONTH_CENTURY)
                bct.year += 0x100;

        clock_dbgprint_bcd(sc->dev, CLOCK_DBG_READ, &bct);
        return (clock_bcd_to_ts(&bct, ts, false));
}

static int
hym8563_settime(device_t dev, struct timespec *ts)
{
        struct hym8563_softc    *sc;
        struct bcd_clocktime     bct;
        uint8_t                  buf[7];
        int                      rv;

        sc = device_get_softc(dev);
        ts->tv_sec -= utc_offset();
        clock_ts_to_bcd(ts, &bct, false);
        clock_dbgprint_bcd(sc->dev, CLOCK_DBG_WRITE, &bct);

        buf[0] = bct.sec;       /* Also clear VL flag */
        buf[1] = bct.min;
        buf[2] = bct.hour;
        buf[3] = bct.day;
        buf[4] = bct.dow;
        buf[5] = bct.mon;
        buf[6] = bct.year & 0xFF;
        if (bct.year > 0x99)
                buf[5] |= HYM8563_MONTH_CENTURY;

        /* Stop RTC */
        rv = hym8563_write_1(sc->dev, HYM8563_CTRL1, HYM8563_CTRL1_STOP);
        if (rv != 0) {
                device_printf(sc->dev, "Cannot write CTRL1 register: %d\n", rv);
                return (rv);
        }

        /* Write all RTC data */
        rv = hym8563_write_buf(sc->dev, HYM8563_SEC, buf, sizeof(buf));
        if (rv != 0) {
                device_printf(sc->dev, "Cannot write time registers: %d\n", rv);
                return (rv);
        }
        return (rv);

        /* Start RTC again */
        rv = hym8563_write_1(sc->dev, HYM8563_CTRL1, 0);
        if (rv != 0) {
                device_printf(sc->dev, "Cannot write CTRL1 register: %d\n", rv);
                return (rv);
        }

        return (0);
}

static void
hym8563_init(void *arg)
{
        struct hym8563_softc *sc;
        uint8_t reg;
        int rv;

        sc = (struct hym8563_softc*)arg;
        config_intrhook_disestablish(&sc->init_hook);

        /* Clear CTL1 register (stop and test bits) */
        rv = hym8563_write_1(sc->dev, HYM8563_CTRL1, 0);
        if (rv != 0) {
                device_printf(sc->dev, "Cannot init CTRL1 register: %d\n", rv);
                return;
        }

        /* Disable interrupts and alarms */
        rv = hym8563_read_1(sc->dev, HYM8563_CTRL2, &reg);
        if (rv != 0) {
                device_printf(sc->dev, "Cannot read CTRL2 register: %d\n", rv);
                return;
        }
        rv &= ~HYM8563_CTRL2_TI_TP;
        rv &= ~HYM8563_CTRL2_AF;
        rv &= ~HYM8563_CTRL2_TF;
        rv = hym8563_write_1(sc->dev, HYM8563_CTRL2, 0);
        if (rv != 0) {
                device_printf(sc->dev, "Cannot write CTRL2 register: %d\n", rv);
                return;
        }

        /*
         * Register as a system realtime clock.
         */
        clock_register_flags(sc->dev, 1000000, 0);
        clock_schedule(sc->dev, 1);
        return;
}

static int
hym8563_probe(device_t dev)
{

#if defined(FDT)
        if (!ofw_bus_status_okay(dev))
                return (ENXIO);

        if (ofw_bus_search_compatible(dev, compat_data)->ocd_data != 0) {
                device_set_desc(dev, "HYM8694 RTC");
                return (BUS_PROBE_DEFAULT);
        }
#endif
        return (ENXIO);
}

static int
hym8563_attach(device_t dev)
{
        struct hym8563_softc *sc;

        sc = device_get_softc(dev);
        sc->dev = dev;

#if defined(FDT) && !defined(__powerpc__)
        if (hym8563_attach_clocks(sc) != 0)
                return(ENXIO);
#endif

        /*
         * Chip init must wait until interrupts are enabled.  Often i2c access
         * works only when the interrupts are available.
         */
        sc->init_hook.ich_func = hym8563_init;
        sc->init_hook.ich_arg = sc;
        if (config_intrhook_establish(&sc->init_hook) != 0)
                return (ENOMEM);

        return (0);
}

static int
hym8563_detach(device_t dev)
{

        clock_unregister(dev);
        return (0);
}

static device_method_t hym8563_methods[] = {
        /* device_if methods */
        DEVMETHOD(device_probe,         hym8563_probe),
        DEVMETHOD(device_attach,        hym8563_attach),
        DEVMETHOD(device_detach,        hym8563_detach),

        /* clock_if methods */
        DEVMETHOD(clock_gettime,        hym8563_gettime),
        DEVMETHOD(clock_settime,        hym8563_settime),

        DEVMETHOD_END,
};

static DEFINE_CLASS_0(hym8563_rtc, hym8563_driver, hym8563_methods,
    sizeof(struct hym8563_softc));
EARLY_DRIVER_MODULE(hym8563, iicbus, hym8563_driver, NULL, NULL,
    BUS_PASS_SUPPORTDEV + BUS_PASS_ORDER_FIRST);
MODULE_VERSION(hym8563, 1);
MODULE_DEPEND(hym8563, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
#if defined(FDT)
IICBUS_FDT_PNP_INFO(compat_data);
#endif