/* $NetBSD: twl4030.c,v 1.9 2025/09/17 13:49:13 thorpej Exp $ */

/*-
 * Copyright (c) 2019 Jared McNeill <jmcneill@invisible.ca>
 * 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 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 "opt_fdt.h"

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: twl4030.c,v 1.9 2025/09/17 13:49:13 thorpej Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/conf.h>
#include <sys/bus.h>
#include <sys/kmem.h>
#include <sys/gpio.h>

#include <dev/i2c/i2cvar.h>

#include <dev/fdt/fdtvar.h>

#define TWL_PIN_COUNT   16

/* TWL4030 is a multi-function IC. Each module is at a separate I2C address */
#define ADDR_USB        0x00
#define ADDR_INT        0x01
#define ADDR_AUX        0x02
#define ADDR_POWER      0x03

/* INTBR registers */
#define IDCODE_7_0      0x85
#define IDCODE_15_8     0x86
#define IDCODE_23_16    0x87
#define IDCODE_31_24    0x88

/* GPIO registers */
#define GPIOBASE                0x98
#define GPIODATAIN(pin)         (GPIOBASE + 0x00 + (pin) / 8)
#define GPIODATADIR(pin)        (GPIOBASE + 0x03 + (pin) / 8)
#define CLEARGPIODATAOUT(pin)   (GPIOBASE + 0x09 + (pin) / 8)
#define SETGPIODATAOUT(pin)     (GPIOBASE + 0x0c + (pin) / 8)
#define  PIN_BIT(pin)           __BIT((pin) % 8)
#define GPIOPUPDCTR(pin)        (GPIOBASE + 0x13 + (n) / 4)
#define  PUPD_BITS(pin)         __BITS((pin) % 4 + 1, (pin) % 4)

/* POWER registers */
#define SECONDS_REG             0x1c
#define MINUTES_REG             0x1d
#define HOURS_REG               0x1e
#define DAYS_REG                0x1f
#define MONTHS_REG              0x20
#define YEARS_REG               0x21
#define WEEKS_REG               0x22
#define RTC_CTRL_REG            0x29
#define  GET_TIME               __BIT(6)
#define  STOP_RTC               __BIT(0)

struct twl_softc {
        device_t        sc_dev;
        i2c_tag_t       sc_i2c;
        i2c_addr_t      sc_addr;
        int             sc_phandle;

        int             sc_npins;

        struct todr_chip_handle sc_todr;
};

struct twl_pin {
        struct twl_softc        *pin_sc;
        int                     pin_num;
        int                     pin_flags;
        bool                    pin_actlo;
};

static const struct device_compatible_entry compat_data[] = {
        { .compat = "ti,twl4030" },
        DEVICE_COMPAT_EOL
};

#ifdef FDT
static const struct device_compatible_entry rtc_compat_data[] = {
        { .compat = "ti,twl4030-rtc" },
        DEVICE_COMPAT_EOL
};

static const struct device_compatible_entry gpio_compat_data[] = {
        { .compat = "ti,twl4030-gpio" },
        DEVICE_COMPAT_EOL
};
#endif

static uint8_t
twl_read(struct twl_softc *sc, uint8_t mod, uint8_t reg, int flags)
{
        uint8_t val = 0;
        int error;

        error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP, sc->sc_addr + mod,
            &reg, 1, &val, 1, flags);
        if (error != 0)
                aprint_error_dev(sc->sc_dev, "error reading reg %#x: %d\n", reg, error);

        return val;
}

static void
twl_write(struct twl_softc *sc, uint8_t mod, uint8_t reg, uint8_t val, int flags)
{
        uint8_t buf[2];
        int error;

        buf[0] = reg;
        buf[1] = val;

        error = iic_exec(sc->sc_i2c, I2C_OP_WRITE_WITH_STOP, sc->sc_addr + mod,
            NULL, 0, buf, 2, flags);
        if (error != 0)
                aprint_error_dev(sc->sc_dev, "error writing reg %#x: %d\n", reg, error);
}

#define I2C_LOCK(sc)            iic_acquire_bus((sc)->sc_i2c, I2C_F_POLL)
#define I2C_UNLOCK(sc)          iic_release_bus((sc)->sc_i2c, I2C_F_POLL)

#define INT_READ(sc, reg)       twl_read((sc), ADDR_INT, (reg), I2C_F_POLL)
#define INT_WRITE(sc, reg, val) twl_write((sc), ADDR_INT, (reg), (val), I2C_F_POLL)

#define POWER_READ(sc, reg)     twl_read((sc), ADDR_POWER, (reg), I2C_F_POLL)
#define POWER_WRITE(sc, reg, val) twl_write((sc), ADDR_POWER, (reg), (val), I2C_F_POLL)

static void
twl_rtc_enable(struct twl_softc *sc, bool onoff)
{
        uint8_t rtc_ctrl;

        rtc_ctrl = POWER_READ(sc, RTC_CTRL_REG);
        if (onoff)
                rtc_ctrl |= STOP_RTC;   /* 1: RTC is running */
        else
                rtc_ctrl &= ~STOP_RTC;  /* 0: RTC is frozen */
        POWER_WRITE(sc, RTC_CTRL_REG, rtc_ctrl);
}

static int
twl_rtc_gettime(todr_chip_handle_t tch, struct clock_ymdhms *dt)
{
        struct twl_softc *sc = device_private(tch->todr_dev);
        uint8_t seconds_reg, minutes_reg, hours_reg,
            days_reg, months_reg, years_reg, weeks_reg;

        iic_acquire_bus(sc->sc_i2c, I2C_F_POLL);
        seconds_reg = POWER_READ(sc, SECONDS_REG);
        minutes_reg = POWER_READ(sc, MINUTES_REG);
        hours_reg = POWER_READ(sc, HOURS_REG);
        days_reg = POWER_READ(sc, DAYS_REG);
        months_reg = POWER_READ(sc, MONTHS_REG);
        years_reg = POWER_READ(sc, YEARS_REG);
        weeks_reg = POWER_READ(sc, WEEKS_REG);
        iic_release_bus(sc->sc_i2c, I2C_F_POLL);

        dt->dt_sec = bcdtobin(seconds_reg);
        dt->dt_min = bcdtobin(minutes_reg);
        dt->dt_hour = bcdtobin(hours_reg);
        dt->dt_day = bcdtobin(days_reg);
        dt->dt_mon = bcdtobin(months_reg);
        dt->dt_year = bcdtobin(years_reg) + 2000;
        dt->dt_wday = bcdtobin(weeks_reg);

        return 0;
}

static int
twl_rtc_settime(todr_chip_handle_t tch, struct clock_ymdhms *dt)
{
        struct twl_softc *sc = device_private(tch->todr_dev);

        iic_acquire_bus(sc->sc_i2c, I2C_F_POLL);
        twl_rtc_enable(sc, false);
        POWER_WRITE(sc, SECONDS_REG, bintobcd(dt->dt_sec));
        POWER_WRITE(sc, MINUTES_REG, bintobcd(dt->dt_min));
        POWER_WRITE(sc, HOURS_REG, bintobcd(dt->dt_hour));
        POWER_WRITE(sc, DAYS_REG, bintobcd(dt->dt_day));
        POWER_WRITE(sc, MONTHS_REG, bintobcd(dt->dt_mon));
        POWER_WRITE(sc, YEARS_REG, bintobcd(dt->dt_year % 100));
        POWER_WRITE(sc, WEEKS_REG, bintobcd(dt->dt_wday));
        twl_rtc_enable(sc, true);
        iic_release_bus(sc->sc_i2c, I2C_F_POLL);

        return 0;
}

#ifdef FDT
static int
twl_gpio_config(struct twl_softc *sc, int pin, int flags)
{
        uint8_t dir;

        KASSERT(pin >= 0 && pin < sc->sc_npins);

        dir = INT_READ(sc, GPIODATADIR(pin));

        switch (flags & (GPIO_PIN_INPUT|GPIO_PIN_OUTPUT)) {
        case GPIO_PIN_INPUT:
                dir &= ~PIN_BIT(pin);
                break;
        case GPIO_PIN_OUTPUT:
                dir |= PIN_BIT(pin);
                break;
        default:
                return EINVAL;
        }

        INT_WRITE(sc, GPIODATADIR(pin), dir);

        return 0;
}

static void *
twl_gpio_acquire(device_t dev, const void *data, size_t len, int flags)
{
        struct twl_softc * const sc = device_private(dev);
        struct twl_pin *gpin;
        const u_int *gpio = data;
        int error;

        if (len != 12)
                return NULL;

        const uint8_t pin = be32toh(gpio[1]) & 0xff;
        const bool actlo = (be32toh(gpio[2]) & __BIT(0)) != 0;
        
        if (pin >= sc->sc_npins)
                return NULL;

        I2C_LOCK(sc);
        error = twl_gpio_config(sc, pin, flags);
        I2C_UNLOCK(sc);

        if (error != 0) {
                device_printf(dev, "bad pin %d config %#x\n", pin, flags);
                return NULL;
        }

        gpin = kmem_zalloc(sizeof(*gpin), KM_SLEEP);
        gpin->pin_sc = sc;
        gpin->pin_num = pin;
        gpin->pin_flags = flags;
        gpin->pin_actlo = actlo;

        return gpin;
}

static void
twl_gpio_release(device_t dev, void *priv)
{
        struct twl_softc * const sc = device_private(dev);
        struct twl_pin *gpin = priv;

        I2C_LOCK(sc);
        twl_gpio_config(sc, gpin->pin_num, GPIO_PIN_INPUT);
        I2C_UNLOCK(sc);

        kmem_free(gpin, sizeof(*gpin));
}

static int
twl_gpio_read(device_t dev, void *priv, bool raw)
{
        struct twl_softc * const sc = device_private(dev);
        struct twl_pin *gpin = priv;
        uint8_t gpio;
        int val;

        I2C_LOCK(sc);
        gpio = INT_READ(sc, GPIODATAIN(gpin->pin_num));
        I2C_UNLOCK(sc);

        val = __SHIFTOUT(gpio, PIN_BIT(gpin->pin_num));
        if (!raw && gpin->pin_actlo)
                val = !val;

        return val;
}

static void
twl_gpio_write(device_t dev, void *priv, int val, bool raw)
{
        struct twl_softc * const sc = device_private(dev);
        struct twl_pin *gpin = priv;

        if (!raw && gpin->pin_actlo)
                val = !val;

        I2C_LOCK(sc);
        if (val)
                INT_WRITE(sc, SETGPIODATAOUT(gpin->pin_num), PIN_BIT(gpin->pin_num));
        else
                INT_WRITE(sc, CLEARGPIODATAOUT(gpin->pin_num), PIN_BIT(gpin->pin_num));
        I2C_UNLOCK(sc);
}

static struct fdtbus_gpio_controller_func twl_gpio_funcs = {
        .acquire = twl_gpio_acquire,
        .release = twl_gpio_release,
        .read = twl_gpio_read,
        .write = twl_gpio_write,
};
#endif /* !FDT */

static void
twl_rtc_attach(struct twl_softc *sc, const int phandle)
{
        iic_acquire_bus(sc->sc_i2c, I2C_F_POLL);
        twl_rtc_enable(sc, true);
        iic_release_bus(sc->sc_i2c, I2C_F_POLL);

        sc->sc_todr.todr_gettime_ymdhms = twl_rtc_gettime;
        sc->sc_todr.todr_settime_ymdhms = twl_rtc_settime;
        sc->sc_todr.todr_dev = sc->sc_dev;
        todr_attach(&sc->sc_todr);
}

static void
twl_gpio_attach(struct twl_softc *sc, const int phandle)
{
#ifdef FDT
        fdtbus_register_gpio_controller(sc->sc_dev, phandle, &twl_gpio_funcs);
#endif
}

static int
twl_match(device_t parent, cfdata_t match, void *aux)
{
        struct i2c_attach_args *ia = aux;
        int match_result;

        if (iic_use_direct_match(ia, match, compat_data, &match_result))
                return match_result;

        if (ia->ia_addr == 0x48)
                return I2C_MATCH_ADDRESS_ONLY;

        return 0;
}

static void
twl_attach(device_t parent, device_t self, void *aux)
{
        struct twl_softc * const sc = device_private(self);
        struct i2c_attach_args *ia = aux;
        uint32_t idcode;

        sc->sc_dev = self;
        sc->sc_i2c = ia->ia_tag;
        sc->sc_addr = ia->ia_addr;
        sc->sc_npins = TWL_PIN_COUNT;

        aprint_naive("\n");
        aprint_normal(": TWL4030");

#ifdef FDT
        if (devhandle_type(device_handle(self)) == DEVHANDLE_TYPE_OF) {
                sc->sc_phandle = devhandle_to_of(device_handle(self));
                for (int child = OF_child(sc->sc_phandle); child;
                     child = OF_peer(child)) {
                        if (of_compatible_match(child, gpio_compat_data)) {
                                aprint_normal(", GPIO");
                                twl_gpio_attach(sc, child);
                        } else if (of_compatible_match(child,
                                                       rtc_compat_data)) {
                                aprint_normal(", RTC");
                                twl_rtc_attach(sc, child);
                        }
                }
        } else
#endif
        {
                aprint_normal("\n");
                twl_gpio_attach(sc, -1);
                twl_rtc_attach(sc, -1);
        }

        I2C_LOCK(sc);
        idcode = INT_READ(sc, IDCODE_7_0);
        idcode |= (uint32_t)INT_READ(sc, IDCODE_15_8) << 8;
        idcode |= (uint32_t)INT_READ(sc, IDCODE_23_16) << 16;
        idcode |= (uint32_t)INT_READ(sc, IDCODE_31_24) << 24;
        I2C_UNLOCK(sc);

        aprint_normal(", IDCODE 0x%08x\n", idcode);
}

CFATTACH_DECL_NEW(twl, sizeof(struct twl_softc),
    twl_match, twl_attach, NULL, NULL);