/*      $OpenBSD: tsl2560.c,v 1.8 2022/04/06 18:59:28 naddy Exp $       */

/*
 * Copyright (c) 2005 Mark Kettenis
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/sensors.h>

#include <dev/i2c/i2cvar.h>

/* TSL2560/61 registers */
#define TSL2560_REG_CONTROL     0x80
#define  TSL2560_CONTROL_POWER  0x03
#define TSL2560_REG_TIMING      0x81
#define  TSL2560_TIMING_GAIN    0x10 /* high gain (16x) */
#define  TSL2560_TIMING_INTEG0  0x00 /* 13.7ms */
#define  TSL2560_TIMING_INTEG1  0x01 /* 101ms */
#define  TSL2560_TIMING_INTEG2  0x02 /* 402ms */
#define TSL2560_REG_ID          0x8a
#define TSL2560_REG_DATA0       0xac
#define TSL2560_REG_DATA1       0xae

struct tsl_softc {
        struct device sc_dev;
        i2c_tag_t sc_tag;
        i2c_addr_t sc_addr;

        struct ksensor sc_sensor;
        struct ksensordev sc_sensordev;
};

int     tsl_match(struct device *, void *, void *);
void    tsl_attach(struct device *, struct device *, void *);

void    tsl_refresh(void *);
u_int64_t tsl_lux(u_int32_t, u_int32_t);

const struct cfattach tsl_ca = {
        sizeof(struct tsl_softc), tsl_match, tsl_attach
};

struct cfdriver tsl_cd = {
        NULL, "tsl", DV_DULL
};

int
tsl_match(struct device *parent, void *match, void *aux)
{
        struct i2c_attach_args *ia = aux;

        if (strcmp(ia->ia_name, "tsl2560") == 0)
                return (1);
        return (0);
}

void
tsl_attach(struct device *parent, struct device *self, void *aux)
{
        struct tsl_softc *sc = (struct tsl_softc *)self;
        struct i2c_attach_args *ia = aux;
        u_int8_t cmd, data;

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

        iic_acquire_bus(sc->sc_tag, 0);
        cmd = TSL2560_REG_CONTROL; data = TSL2560_CONTROL_POWER;
        if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
            sc->sc_addr, &cmd, sizeof cmd, &data, sizeof data, 0)) {
                iic_release_bus(sc->sc_tag, 0);
                printf(": power up failed\n");
                return;
        }
        cmd = TSL2560_REG_TIMING;
        data = TSL2560_TIMING_GAIN | TSL2560_TIMING_INTEG2;
        if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
            sc->sc_addr, &cmd, sizeof cmd, &data, sizeof data, 0)) {
                iic_release_bus(sc->sc_tag, 0);
                printf(": cannot write timing register\n");
                return;
        }
        cmd = TSL2560_REG_ID;
        if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
            sc->sc_addr, &cmd, sizeof cmd, &data, sizeof data, 0)) {
                iic_release_bus(sc->sc_tag, 0);
                printf(": cannot read ID register\n");
                return;
        }
        iic_release_bus(sc->sc_tag, 0);

        switch (data >> 4) {
        case 0:
                printf(": TSL2560 rev %x", data & 0x0f);
                break;
        case 1:
                printf(": TSL2561 rev %x", data & 0x0f);
                break;
        default:
                printf(": unknown part number %x", data >> 4);
                break;
        }

        /* Initialize sensor data. */
        strlcpy(sc->sc_sensordev.xname, sc->sc_dev.dv_xname,
            sizeof(sc->sc_sensordev.xname));
        sc->sc_sensor.type = SENSOR_LUX;

        if (sensor_task_register(sc, tsl_refresh, 5) == NULL) {
                printf(": unable to register update task\n");
                return;
        }

        sensor_attach(&sc->sc_sensordev, &sc->sc_sensor);
        sensordev_install(&sc->sc_sensordev);

        printf("\n");
}

void
tsl_refresh(void *arg)
{
        struct tsl_softc *sc = arg;
        u_int8_t cmd, data[2];
        u_int16_t chan0, chan1;

        iic_acquire_bus(sc->sc_tag, 0);
        cmd = TSL2560_REG_DATA0;
        if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
            sc->sc_addr, &cmd, sizeof cmd, &data, sizeof data, 0)) {
                iic_release_bus(sc->sc_tag, 0);
                sc->sc_sensor.flags |= SENSOR_FINVALID;
                return;
        }
        chan0 = data[1] << 8 | data[0];
        cmd = TSL2560_REG_DATA1;
        if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
            sc->sc_addr, &cmd, sizeof cmd, &data, sizeof data, 0)) {
                iic_release_bus(sc->sc_tag, 0);
                sc->sc_sensor.flags |= SENSOR_FINVALID;
                return;
        }
        chan1 = data[1] << 8 | data[0];
        iic_release_bus(sc->sc_tag, 0);

        sc->sc_sensor.value = tsl_lux(chan0, chan1);
        sc->sc_sensor.flags &= ~SENSOR_FINVALID;
}

/* Precision for fixed-point math. */
#define TSL2560_RATIO_SCALE     9
#define TSL2560_LUX_SCALE       14

/*
 * The TSL2560/2561 comes in a ChipScale or TMB-6 package and the
 * calibration is slightly different for each package.  The constants
 * below are for the TMB-6 package.
 */

#define TSL2560_K1T     0x0040  /* 0.125 * (1 << TSL2560_RATIO_SCALE) */
#define TSL2560_B1T     0x01f2  /* 0.0304 * (1 << TSL2560_LUX_SCALE) */
#define TSL2560_M1T     0x01be  /* 0.0272 * (1 << TSL2560_LUX_SCALE) */

#define TSL2560_K2T     0x0080  /* 0.250 * (1 << TSL2560_RATIO_SCALE) */
#define TSL2560_B2T     0x0214  /* 0.0324 * (1 << TSL2560_LUX_SCALE) */
#define TSL2560_M2T     0x02d1  /* 0.0440 * (1 << TSL2560_LUX_SCALE) */

#define TSL2560_K3T     0x00c0  /* 0.375 * (1 << TSL2560_RATIO_SCALE) */
#define TSL2560_B3T     0x023f  /* 0.0351 * (1 << TSL2560_LUX_SCALE) */
#define TSL2560_M3T     0x037b  /* 0.0544 * (1 << TSL2560_LUX_SCALE) */

#define TSL2560_K4T     0x0080  /* 0.50 * (1 << TSL2560_RATIO_SCALE) */
#define TSL2560_B4T     0x0214  /* 0.0381 * (1 << TSL2560_LUX_SCALE) */
#define TSL2560_M4T     0x02d1  /* 0.0624 * (1 << TSL2560_LUX_SCALE) */

#define TSL2560_K5T     0x0138  /* 0.61 * (1 << TSL2560_RATIO_SCALE) */
#define TSL2560_B5T     0x016f  /* 0.0224 * (1 << TSL2560_LUX_SCALE) */
#define TSL2560_M5T     0x01fc  /* 0.0310 * (1 << TSL2560_LUX_SCALE) */

#define TSL2560_K6T     0x0100  /* 0.80 * (1 << TSL2560_RATIO_SCALE) */
#define TSL2560_B6T     0x0270  /* 0.0128 * (1 << TSL2560_LUX_SCALE) */
#define TSL2560_M6T     0x03fe  /* 0.0153 * (1 << TSL2560_LUX_SCALE) */

#define TSL2560_K7T     0x019a  /* 1.3 * (1 << TSL2560_RATIO_SCALE) */
#define TSL2560_B7T     0x0018  /* 0.00146 * (1 << TSL2560_LUX_SCALE) */
#define TSL2560_M7T     0x0012  /* 0.00112 * (1 << TSL2560_LUX_SCALE) */

u_int64_t
tsl_lux(u_int32_t chan0, u_int32_t chan1)
{
        u_int32_t ratio, ratio1;
        u_int32_t b, m;
        int64_t lux;

        ratio1 = 0;
        if (chan0 != 0)
                ratio1 = (chan1 << (TSL2560_RATIO_SCALE + 1)) / chan0;
        ratio = (ratio1 + 1) >> 1;

        b = 0, m = 0;
        if (ratio <= TSL2560_K1T)
                b = TSL2560_B1T, m = TSL2560_M1T;
        else if (ratio <= TSL2560_K2T)
                b = TSL2560_B2T, m = TSL2560_M2T;
        else if (ratio <= TSL2560_K3T)
                b = TSL2560_B3T, m = TSL2560_M3T;
        else if (ratio <= TSL2560_K4T)
                b = TSL2560_B4T, m = TSL2560_M4T;
        else if (ratio <= TSL2560_K5T)
                b = TSL2560_B5T, m = TSL2560_M5T;
        else if (ratio <= TSL2560_K6T)
                b = TSL2560_B6T, m = TSL2560_M6T;
        else if (ratio <= TSL2560_K7T)
                b = TSL2560_B7T, m = TSL2560_M7T;

        lux = b * chan0 - m * chan1;
        if (lux < 0)
                lux = 0;
        return ((lux * 1000000) >> TSL2560_LUX_SCALE);
}