/* $NetBSD: act8846.c,v 1.6 2019/07/27 16:02:27 thorpej Exp $ */

/*-
 * Copyright (c) 2015 Jared D. 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.
 */

//#define ACT_DEBUG

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: act8846.c,v 1.6 2019/07/27 16:02:27 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 <dev/i2c/i2cvar.h>
#include <dev/i2c/act8846.h>

#define ACT_BATTVOL_STATUS_REG          0x00
#define ACT_THERMAL_CTRL_REG            0x01
#define ACT_DCDC1_BASE_REG              0x10
#define ACT_DCDC2_BASE_REG              0x20
#define ACT_DCDC3_BASE_REG              0x30
#define ACT_DCDC4_BASE_REG              0x40
#define ACT_LDO1_BASE_REG               0x50
#define ACT_LDO2_BASE_REG               0x58
#define ACT_LDO3_BASE_REG               0x60
#define ACT_LDO4_BASE_REG               0x68
#define ACT_LDO5_BASE_REG               0x70
#define ACT_LDO6_BASE_REG               0x80
#define ACT_LDO7_BASE_REG               0x90
#define ACT_LDO8_BASE_REG               0xa0
#define ACT_LDO9_BASE_REG               0xb0

#define ACT_VSET0_OFFSET                0
#define ACT_VSET1_OFFSET                1
#define ACT_DCDC_CTRL_OFFSET            2
#define ACT_LDO_CTRL_OFFSET             1

#define ACT_VSET_VSET                   __BITS(5,0)

#define ACT_DCDC_CTRL_ON                __BIT(7)

#define ACT_LDO_CTRL_ON                 __BIT(7)

enum act8846_ctrl_type {
        ACT_CTRL_DCDC,
        ACT_CTRL_LDO,
};

#define ACT_VOLTAGE_MIN                 600
#define ACT_VOLTAGE_MAX                 3900

struct act8846_ctrl {
        device_t        c_dev;

        const char *    c_name;
        u_int           c_min;
        u_int           c_max;
        uint8_t         c_base;
        enum act8846_ctrl_type c_type;
};

#define ACT_CTRL(name, base, type)                              \
        { .c_name = (name),                                     \
          .c_min = ACT_VOLTAGE_MIN, .c_max = ACT_VOLTAGE_MAX,   \
          .c_base = ACT_ ## base ## _BASE_REG, .c_type = (type) }

#define ACT_DCDC(name, base)    ACT_CTRL(name, base, ACT_CTRL_DCDC)
#define ACT_LDO(name, base)     ACT_CTRL(name, base, ACT_CTRL_LDO)

static const struct act8846_ctrl act8846_ctrls[] = {
        ACT_DCDC("DCDC1", DCDC1),       /* VCC_DDR */
        ACT_DCDC("DCDC2", DCDC2),       /* VDD_LOG */
        ACT_DCDC("DCDC3", DCDC3),       /* VDD_ARM */
        ACT_DCDC("DCDC4", DCDC4),       /* VCC_IO */
        ACT_LDO("LDO1", LDO1),          /* VDD_10 */
        ACT_LDO("LDO2", LDO2),          /* VCC_25 */
        ACT_LDO("LDO3", LDO3),          /* VCC18_CIF */
        ACT_LDO("LDO4", LDO4),          /* VCCA_33 */
        ACT_LDO("LDO5", LDO5),          /* VCC_TOUCH */
        ACT_LDO("LDO6", LDO6),          /* VCC33 */
        ACT_LDO("LDO7", LDO7),          /* VCC18_IO */
        ACT_LDO("LDO8", LDO8),          /* VCC28_CIF */
#if 0
        ACT_LDO("LDO9", LDO9),          /* VDD_RTC (Always-ON) */
#endif
};

/* From datasheet, Table 5: REGx/VSET[] Output Voltage Setting */
static const u_int act8846_vset[] = {
        600, 625, 650, 675, 700, 725, 750, 775,
        800, 825, 850, 875, 900, 925, 950, 975,
        1000, 1025, 1050, 1075, 1100, 1125, 1150, 1175,
        1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550,
        1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950,
        2000, 2050, 2100, 2150, 2200, 2250, 2300, 2350,
        2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100,
        3200, 3300, 3400, 3500, 3600, 3700, 3800, 3900
};

struct act8846_softc {
        device_t        sc_dev;
        i2c_tag_t       sc_i2c;
        i2c_addr_t      sc_addr;

        u_int           sc_nctrl;
        struct act8846_ctrl *sc_ctrl;
};

static int      act8846_match(device_t, cfdata_t, void *);
static void     act8846_attach(device_t, device_t, void *);

static int      act8846_read(struct act8846_softc *, uint8_t, uint8_t *);
static int      act8846_write(struct act8846_softc *, uint8_t, uint8_t);

static void     act8846_print(struct act8846_ctrl *c);

CFATTACH_DECL_NEW(act8846pm, sizeof(struct act8846_softc),
    act8846_match, act8846_attach, NULL, NULL);

static int
act8846_match(device_t parent, cfdata_t match, void *aux)
{
        struct i2c_attach_args *ia = aux;

        if (ia->ia_addr == 0x5a)
                return I2C_MATCH_ADDRESS_ONLY;

        return 0;
}

static void
act8846_attach(device_t parent, device_t self, void *aux)
{
        struct act8846_softc *sc = device_private(self);
        struct i2c_attach_args *ia = aux;
        u_int n;

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

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

        sc->sc_nctrl = __arraycount(act8846_ctrls);
        sc->sc_ctrl = kmem_alloc(sizeof(act8846_ctrls), KM_SLEEP);
        memcpy(sc->sc_ctrl, act8846_ctrls, sizeof(act8846_ctrls));
        for (n = 0; n < sc->sc_nctrl; n++) {
                sc->sc_ctrl[n].c_dev = self;
        }

        for (n = 0; n < sc->sc_nctrl; n++) {
                act8846_print(&sc->sc_ctrl[n]);
        }
}

static int
act8846_read(struct act8846_softc *sc, uint8_t reg, uint8_t *val)
{
        return iic_smbus_read_byte(sc->sc_i2c, sc->sc_addr, reg, val, 0);
}

static int
act8846_write(struct act8846_softc *sc, uint8_t reg, uint8_t val)
{
        return iic_smbus_write_byte(sc->sc_i2c, sc->sc_addr, reg, val, 0);
}

static void
act8846_print(struct act8846_ctrl *c)
{
        struct act8846_softc *sc = device_private(c->c_dev);
        u_int voltage;
        bool enabled;

        device_printf(sc->sc_dev, "%s:", c->c_name);
        if (act8846_get_voltage(c, &voltage)) {
                printf(" [??? V]");
        } else {
                printf(" [%d.%03dV]", voltage / 1000,
                    voltage % 1000);
        }
        if (act8846_is_enabled(c, &enabled)) {
                printf(" [unknown state]");
        } else {
                printf(" [%s]", enabled ? "ON" : "OFF");
        }
        printf("\n");
}

struct act8846_ctrl *
act8846_lookup(device_t dev, const char *name)
{
        struct act8846_softc *sc = device_private(dev);
        struct act8846_ctrl *c;
        u_int n;

        for (n = 0; n < sc->sc_nctrl; n++) {
                c = &sc->sc_ctrl[n];
                if (strcmp(c->c_name, name) == 0) {
                        return c;
                }
        }

        return NULL;
}

int
act8846_set_voltage(struct act8846_ctrl *c, u_int min, u_int max)
{
        struct act8846_softc *sc = device_private(c->c_dev);
        uint8_t val;
        int error, n;

        if (min < c->c_min || min > c->c_max || (min % 25) != 0)
                return EINVAL;

        for (n = 0; n < __arraycount(act8846_vset); n++) {
                if (min >= act8846_vset[n] && max <= act8846_vset[n]) {
                        break;
                }
        }
        if (n == __arraycount(act8846_vset))
                return EINVAL;

        val = __SHIFTIN(n, ACT_VSET_VSET);

        iic_acquire_bus(sc->sc_i2c, 0);
        error = act8846_write(sc, c->c_base + ACT_VSET0_OFFSET, val);
        iic_release_bus(sc->sc_i2c, 0);
#ifdef ACT_DEBUG
        if (error == 0)
                act8846_print(c);
#endif
        return error;
}

int
act8846_get_voltage(struct act8846_ctrl *c, u_int *pvol)
{
        struct act8846_softc *sc = device_private(c->c_dev);
        uint8_t val;
        int error;

        iic_acquire_bus(sc->sc_i2c, 0);
        error = act8846_read(sc, c->c_base + ACT_VSET0_OFFSET, &val);
        iic_release_bus(sc->sc_i2c, 0);
        if (error)
                return error;

        *pvol = act8846_vset[__SHIFTOUT(val, ACT_VSET_VSET)];

        return 0;
}

int
act8846_is_enabled(struct act8846_ctrl *c, bool *penabled)
{
        struct act8846_softc *sc = device_private(c->c_dev);
        uint8_t val, regoff, regmask;
        int error;

        if (c->c_type == ACT_CTRL_DCDC) {
                regoff = ACT_DCDC_CTRL_OFFSET;
                regmask = ACT_DCDC_CTRL_ON;
        } else {
                regoff = ACT_LDO_CTRL_OFFSET;
                regmask = ACT_LDO_CTRL_ON;
        }

        iic_acquire_bus(sc->sc_i2c, 0);
        error = act8846_read(sc, c->c_base + regoff, &val);
        iic_release_bus(sc->sc_i2c, 0);
        if (error)
                return error;

        *penabled = !!(val & regmask);
        return 0;
}

int
act8846_enable(struct act8846_ctrl *c)
{
        struct act8846_softc *sc = device_private(c->c_dev);
        uint8_t val, regoff, regmask;
        int error;

        if (c->c_type == ACT_CTRL_DCDC) {
                regoff = ACT_DCDC_CTRL_OFFSET;
                regmask = ACT_DCDC_CTRL_ON;
        } else {
                regoff = ACT_LDO_CTRL_OFFSET;
                regmask = ACT_LDO_CTRL_ON;
        }

        iic_acquire_bus(sc->sc_i2c, 0);
        if ((error = act8846_read(sc, c->c_base + regoff, &val)) != 0)
                goto done;
        val |= regmask;
        error = act8846_write(sc, c->c_base + regoff, val);
done:
        iic_release_bus(sc->sc_i2c, 0);
#ifdef ACT_DEBUG
        if (error == 0)
                act8846_print(c);
#endif

        return error;
}

int
act8846_disable(struct act8846_ctrl *c)
{
        struct act8846_softc *sc = device_private(c->c_dev);
        uint8_t val, regoff, regmask;
        int error;

        if (c->c_type == ACT_CTRL_DCDC) {
                regoff = ACT_DCDC_CTRL_OFFSET;
                regmask = ACT_DCDC_CTRL_ON;
        } else {
                regoff = ACT_LDO_CTRL_OFFSET;
                regmask = ACT_LDO_CTRL_ON;
        }

        iic_acquire_bus(sc->sc_i2c, 0);
        if ((error = act8846_read(sc, c->c_base + regoff, &val)) != 0)
                goto done;
        val &= ~regmask;
        error = act8846_write(sc, c->c_base + regoff, val);
done:
        iic_release_bus(sc->sc_i2c, 0);
#ifdef ACT_DEBUG
        if (error == 0)
                act8846_print(c);
#endif

        return error;
}