/*-
 * Copyright (c) 2019 Michal Meloun <mmel@FreeBSD.org>
 *
 * 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 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 AUTHOR 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>
/*
 * MAX77620 PMIC driver
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/gpio.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/rman.h>
#include <sys/sx.h>

#include <machine/bus.h>

#include <dev/regulator/regulator.h>
#include <dev/fdt/fdt_pinctrl.h>
#include <dev/gpio/gpiobusvar.h>
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>

#include <dt-bindings/mfd/max77620.h>

#include "clock_if.h"
#include "regdev_if.h"

#include "max77620.h"

static struct ofw_compat_data compat_data[] = {
        {"maxim,max77620",      1},
        {NULL,                  0},
};

#define LOCK(_sc)               sx_xlock(&(_sc)->lock)
#define UNLOCK(_sc)             sx_xunlock(&(_sc)->lock)
#define LOCK_INIT(_sc)          sx_init(&(_sc)->lock, "max77620")
#define LOCK_DESTROY(_sc)       sx_destroy(&(_sc)->lock);
#define ASSERT_LOCKED(_sc)      sx_assert(&(_sc)->lock, SA_XLOCKED);
#define ASSERT_UNLOCKED(_sc)    sx_assert(&(_sc)->lock, SA_UNLOCKED);

#define MAX77620_DEVICE_ID      0x0C

/*
 * Raw register access function.
 */
int
max77620_read(struct max77620_softc *sc, uint8_t reg, uint8_t *val)
{
        uint8_t addr;
        int rv;
        struct iic_msg msgs[2] = {
                {0, IIC_M_WR, 1, &addr},
                {0, IIC_M_RD, 1, val},
        };

        msgs[0].slave = sc->bus_addr;
        msgs[1].slave = sc->bus_addr;
        addr = reg;

        rv = iicbus_transfer(sc->dev, msgs, 2);
        if (rv != 0) {
                device_printf(sc->dev,
                    "Error when reading reg 0x%02X, rv: %d\n", reg,  rv);
                return (EIO);
        }

        return (0);
}

int max77620_read_buf(struct max77620_softc *sc, uint8_t reg, uint8_t *buf,
    size_t size)
{
        uint8_t addr;
        int rv;
        struct iic_msg msgs[2] = {
                {0, IIC_M_WR, 1, &addr},
                {0, IIC_M_RD, size, buf},
        };

        msgs[0].slave = sc->bus_addr;
        msgs[1].slave = sc->bus_addr;
        addr = reg;

        rv = iicbus_transfer(sc->dev, msgs, 2);
        if (rv != 0) {
                device_printf(sc->dev,
                    "Error when reading reg 0x%02X, rv: %d\n", reg,  rv);
                return (EIO);
        }

        return (0);
}

int
max77620_write(struct max77620_softc *sc, uint8_t reg, uint8_t val)
{
        uint8_t data[2];
        int rv;

        struct iic_msg msgs[1] = {
                {0, IIC_M_WR, 2, data},
        };

        msgs[0].slave = sc->bus_addr;
        data[0] = reg;
        data[1] = val;

        rv = iicbus_transfer(sc->dev, msgs, 1);
        if (rv != 0) {
                device_printf(sc->dev,
                    "Error when writing reg 0x%02X, rv: %d\n", reg, rv);
                return (EIO);
        }
        return (0);
}

int
max77620_write_buf(struct max77620_softc *sc, uint8_t reg, uint8_t *buf,
    size_t size)
{
        uint8_t data[1];
        int rv;
        struct iic_msg msgs[2] = {
                {0, IIC_M_WR, 1, data},
                {0, IIC_M_WR | IIC_M_NOSTART, size, buf},
        };

        msgs[0].slave = sc->bus_addr;
        msgs[1].slave = sc->bus_addr;
        data[0] = reg;

        rv = iicbus_transfer(sc->dev, msgs, 2);
        if (rv != 0) {
                device_printf(sc->dev,
                    "Error when writing reg 0x%02X, rv: %d\n", reg, rv);
                return (EIO);
        }
        return (0);
}

int
max77620_modify(struct max77620_softc *sc, uint8_t reg, uint8_t clear,
    uint8_t set)
{
        uint8_t val;
        int rv;

        rv = max77620_read(sc, reg, &val);
        if (rv != 0)
                return (rv);

        val &= ~clear;
        val |= set;

        rv = max77620_write(sc, reg, val);
        if (rv != 0)
                return (rv);

        return (0);
}

static int
max77620_parse_fps(struct max77620_softc *sc, int id, phandle_t node)
{
        int val;

        if (OF_getencprop(node, "maxim,shutdown-fps-time-period-us", &val,
            sizeof(val)) >= 0) {
                val = min(val, MAX77620_FPS_PERIOD_MAX_US);
                val = max(val, MAX77620_FPS_PERIOD_MIN_US);
                sc->shutdown_fps[id] = val;
        }
        if (OF_getencprop(node, "maxim,suspend-fps-time-period-us", &val,
            sizeof(val)) >= 0) {
                val = min(val, MAX77620_FPS_PERIOD_MAX_US);
                val = max(val, MAX77620_FPS_PERIOD_MIN_US);
                sc->suspend_fps[id] = val;
        }
        if (OF_getencprop(node, "maxim,fps-event-source", &val,
            sizeof(val)) >= 0) {
                if (val > 2) {
                        device_printf(sc->dev, "Invalid 'fps-event-source' "
                            "value: %d\n", val);
                        return (EINVAL);
                }
                sc->event_source[id] = val;
        }
        return (0);
}

static int
max77620_parse_fdt(struct max77620_softc *sc, phandle_t node)
{
         phandle_t fpsnode;
         char fps_name[6];
         int i, rv;

        for (i = 0; i < MAX77620_FPS_COUNT; i++) {
                sc->shutdown_fps[i] = -1;
                sc->suspend_fps[i] = -1;
                sc->event_source[i] = -1;
        }

        fpsnode = ofw_bus_find_child(node, "fps");
        if (fpsnode > 0) {
                for (i = 0; i < MAX77620_FPS_COUNT; i++) {
                        sprintf(fps_name, "fps%d", i);
                        node = ofw_bus_find_child(node, fps_name);
                        if (node <= 0)
                                continue;
                        rv = max77620_parse_fps(sc, i, node);
                        if (rv != 0)
                                return (rv);
                }
        }
        return (0);
}

static int
max77620_get_version(struct max77620_softc *sc)
{
        uint8_t buf[6];
        int i;
        int rv;

        /* Verify ID string (5 bytes ). */
        for (i = 0; i <= 6; i++) {
                rv = RD1(sc, MAX77620_REG_CID0 + i , buf + i);
                if (rv != 0) {
                        device_printf(sc->dev, "Cannot read chip ID: %d\n", rv);
                        return (ENXIO);
                }
        }
        if (bootverbose) {
                device_printf(sc->dev,
                    " ID: [0x%02X, 0x%02X, 0x%02X, 0x%02X]\n",
                    buf[0], buf[1], buf[2], buf[3]);
        }
        device_printf(sc->dev, " MAX77620 version - OTP: 0x%02X, ES: 0x%02X\n",
            buf[4], buf[5]);

        return (0);
}

static uint8_t
max77620_encode_fps_period(struct max77620_softc *sc, int val)
{
        uint8_t i;
        int period;

        period = MAX77620_FPS_PERIOD_MIN_US;
        for (i = 0; i < 7; i++) {
                if (period >= val)
                        return (i);
                period *= 2;
        }
        return (i);
}

static int
max77620_init(struct max77620_softc *sc)
{
        uint8_t mask, val, tmp;
        int i, rv;

        mask = 0;
        val = 0;
        for (i = 0; i < MAX77620_FPS_COUNT; i++) {
                if (sc->shutdown_fps[i] != -1) {
                        mask |= MAX77620_FPS_TIME_PERIOD_MASK;
                        tmp  = max77620_encode_fps_period(sc,
                            sc->shutdown_fps[i]);
                        val |= (tmp << MAX77620_FPS_TIME_PERIOD_SHIFT) &
                            MAX77620_FPS_TIME_PERIOD_MASK;
                }

                if (sc->event_source[i] != -1) {
                        mask |= MAX77620_FPS_EN_SRC_MASK;
                        tmp = sc->event_source[i];
                        val |= (tmp << MAX77620_FPS_EN_SRC_SHIFT) &
                            MAX77620_FPS_EN_SRC_MASK;
                        if (sc->event_source[i] == 2) {
                                mask |= MAX77620_FPS_ENFPS_SW_MASK;
                                val |= MAX77620_FPS_ENFPS_SW;
                        }

                }
                rv = RM1(sc, MAX77620_REG_FPS_CFG0 + i, mask, val);
                if (rv != 0) {
                        device_printf(sc->dev, "I/O error: %d\n", rv);
                        return (ENXIO);
                }
        }

        /* Global mask interrupts */
        rv = RM1(sc, MAX77620_REG_INTENLBT, 0x81, 0x81);
        rv = RM1(sc, MAX77620_REG_IRQTOPM, 0x81, 0x81);
        if (rv != 0)
                return (ENXIO);
        return (0);
}
#ifdef notyet
static void
max77620_intr(void *arg)
{
        struct max77620_softc *sc;
        uint8_t intenlbt, intlbt, irqtop, irqtopm, irqsd, irqmasksd;
        uint8_t irq_lvl2_l0_7, irq_lvl2_l8, irq_lvl2_gpio, irq_msk_l0_7, irq_msk_l8;
        uint8_t onoffirq, onoffirqm;

        sc = (struct max77620_softc *)arg;
        /* XXX Finish temperature alarms. */
        RD1(sc, MAX77620_REG_INTENLBT, &intenlbt);
        RD1(sc, MAX77620_REG_INTLBT, &intlbt);

        RD1(sc, MAX77620_REG_IRQTOP, &irqtop);
        RD1(sc, MAX77620_REG_IRQTOPM, &irqtopm);
        RD1(sc, MAX77620_REG_IRQSD, &irqsd);
        RD1(sc, MAX77620_REG_IRQMASKSD, &irqmasksd);
        RD1(sc, MAX77620_REG_IRQ_LVL2_L0_7, &irq_lvl2_l0_7);
        RD1(sc, MAX77620_REG_IRQ_MSK_L0_7, &irq_msk_l0_7);
        RD1(sc, MAX77620_REG_IRQ_LVL2_L8, &irq_lvl2_l8);
        RD1(sc, MAX77620_REG_IRQ_MSK_L8, &irq_msk_l8);
        RD1(sc, MAX77620_REG_IRQ_LVL2_GPIO, &irq_lvl2_gpio);
        RD1(sc, MAX77620_REG_ONOFFIRQ, &onoffirq);
        RD1(sc, MAX77620_REG_ONOFFIRQM, &onoffirqm);
        printf("%s: intlbt: 0x%02X, intenlbt: 0x%02X\n", __func__, intlbt, intenlbt);
        printf("%s: irqtop: 0x%02X, irqtopm: 0x%02X\n", __func__, irqtop, irqtopm);
        printf("%s: irqsd: 0x%02X, irqmasksd: 0x%02X\n", __func__, irqsd, irqmasksd);
        printf("%s: onoffirq: 0x%02X, onoffirqm: 0x%02X\n", __func__, onoffirq, onoffirqm);
        printf("%s: irq_lvl2_l0_7: 0x%02X, irq_msk_l0_7: 0x%02X\n", __func__, irq_lvl2_l0_7, irq_msk_l0_7);
        printf("%s: irq_lvl2_l8: 0x%02X, irq_msk_l8: 0x%02X\n", __func__, irq_lvl2_l8, irq_msk_l8);
        printf("%s: irq_lvl2_gpio: 0x%02X\n", __func__, irq_lvl2_gpio);
}
#endif

static int
max77620_probe(device_t dev)
{

        if (!ofw_bus_status_okay(dev))
                return (ENXIO);

        if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
                return (ENXIO);

        device_set_desc(dev, "MAX77620 PMIC");
        return (BUS_PROBE_DEFAULT);
}

static int
max77620_attach(device_t dev)
{
        struct max77620_softc *sc;
        int rv, rid;
        phandle_t node;

        sc = device_get_softc(dev);
        sc->dev = dev;
        sc->bus_addr = iicbus_get_addr(dev);
        node = ofw_bus_get_node(sc->dev);
        rv = 0;
        LOCK_INIT(sc);

        rid = 0;
        sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
            RF_ACTIVE);
#ifdef notyet /* Interrupt parent is not implemented */
        if (sc->irq_res == NULL) {
                device_printf(dev, "Cannot allocate interrupt.\n");
                rv = ENXIO;
                goto fail;
        }
#endif
        rv = max77620_parse_fdt(sc, node);
        if (rv != 0)
                goto fail;

        rv = max77620_get_version(sc);
        if (rv != 0)
                goto fail;

        rv = max77620_init(sc);
        if (rv != 0)
                goto fail;
        rv = max77620_regulator_attach(sc, node);
        if (rv != 0)
                goto fail;
        rv = max77620_gpio_attach(sc, node);
        if (rv != 0)
                goto fail;

        rv = max77620_rtc_create(sc, node);
        if (rv != 0)
                goto fail;

        fdt_pinctrl_register(dev, NULL);
        fdt_pinctrl_configure_by_name(dev, "default");

        /* Setup interrupt. */
#ifdef notyet
        rv = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
            NULL, max77620_intr, sc, &sc->irq_h);
        if (rv) {
                device_printf(dev, "Cannot setup interrupt.\n");
                goto fail;
        }
#endif
        bus_attach_children(dev);
        return (0);

fail:
        if (sc->irq_h != NULL)
                bus_teardown_intr(dev, sc->irq_res, sc->irq_h);
        if (sc->irq_res != NULL)
                bus_release_resource(dev, SYS_RES_IRQ, 0, sc->irq_res);
        LOCK_DESTROY(sc);
        return (rv);
}

static int
max77620_detach(device_t dev)
{
        struct max77620_softc *sc;
        int error;

        error = bus_generic_detach(dev);
        if (error != 0)
                return (error);

        sc = device_get_softc(dev);
        if (sc->irq_h != NULL)
                bus_teardown_intr(dev, sc->irq_res, sc->irq_h);
        if (sc->irq_res != NULL)
                bus_release_resource(dev, SYS_RES_IRQ, 0, sc->irq_res);
        LOCK_DESTROY(sc);

        return (0);
}

static phandle_t
max77620_gpio_get_node(device_t bus, device_t dev)
{

        /* We only have one child, the GPIO bus, which needs our own node. */
        return (ofw_bus_get_node(bus));
}

static device_method_t max77620_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         max77620_probe),
        DEVMETHOD(device_attach,        max77620_attach),
        DEVMETHOD(device_detach,        max77620_detach),

        /* Regdev interface */
        DEVMETHOD(regdev_map,           max77620_regulator_map),

        /* GPIO protocol interface */
        DEVMETHOD(gpio_get_bus,         max77620_gpio_get_bus),
        DEVMETHOD(gpio_pin_max,         max77620_gpio_pin_max),
        DEVMETHOD(gpio_pin_getname,     max77620_gpio_pin_getname),
        DEVMETHOD(gpio_pin_getflags,    max77620_gpio_pin_getflags),
        DEVMETHOD(gpio_pin_getcaps,     max77620_gpio_pin_getcaps),
        DEVMETHOD(gpio_pin_setflags,    max77620_gpio_pin_setflags),
        DEVMETHOD(gpio_pin_get,         max77620_gpio_pin_get),
        DEVMETHOD(gpio_pin_set,         max77620_gpio_pin_set),
        DEVMETHOD(gpio_pin_toggle,      max77620_gpio_pin_toggle),
        DEVMETHOD(gpio_map_gpios,       max77620_gpio_map_gpios),

        /* fdt_pinctrl interface */
        DEVMETHOD(fdt_pinctrl_configure, max77620_pinmux_configure),

        /* ofw_bus interface */
        DEVMETHOD(ofw_bus_get_node,     max77620_gpio_get_node),

        DEVMETHOD_END
};

static DEFINE_CLASS_0(gpio, max77620_driver, max77620_methods,
    sizeof(struct max77620_softc));
EARLY_DRIVER_MODULE(max77620, iicbus, max77620_driver, NULL, NULL, 74);