// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2011-2015, 2017, 2020, The Linux Foundation. All rights reserved.
 */

#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/iio/consumer.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/thermal.h>

#include "../thermal_core.h"

#define QPNP_TM_REG_DIG_MAJOR           0x01
#define QPNP_TM_REG_TYPE                0x04
#define QPNP_TM_REG_SUBTYPE             0x05
#define QPNP_TM_REG_STATUS              0x08
#define QPNP_TM_REG_SHUTDOWN_CTRL1      0x40
#define QPNP_TM_REG_ALARM_CTRL          0x46

#define QPNP_TM_TYPE                    0x09
#define QPNP_TM_SUBTYPE_GEN1            0x08
#define QPNP_TM_SUBTYPE_GEN2            0x09

#define STATUS_GEN1_STAGE_MASK          GENMASK(1, 0)
#define STATUS_GEN2_STATE_MASK          GENMASK(6, 4)
#define STATUS_GEN2_STATE_SHIFT         4

#define SHUTDOWN_CTRL1_OVERRIDE_S2      BIT(6)
#define SHUTDOWN_CTRL1_THRESHOLD_MASK   GENMASK(1, 0)

#define SHUTDOWN_CTRL1_RATE_25HZ        BIT(3)

#define ALARM_CTRL_FORCE_ENABLE         BIT(7)

#define THRESH_COUNT                    4
#define STAGE_COUNT                     3

/* Over-temperature trip point values in mC */
static const long temp_map_gen1[THRESH_COUNT][STAGE_COUNT] = {
        { 105000, 125000, 145000 },
        { 110000, 130000, 150000 },
        { 115000, 135000, 155000 },
        { 120000, 140000, 160000 },
};

static const long temp_map_gen2_v1[THRESH_COUNT][STAGE_COUNT] = {
        {  90000, 110000, 140000 },
        {  95000, 115000, 145000 },
        { 100000, 120000, 150000 },
        { 105000, 125000, 155000 },
};

#define TEMP_THRESH_STEP                5000 /* Threshold step: 5 C */

#define THRESH_MIN                      0
#define THRESH_MAX                      3

#define TEMP_STAGE_HYSTERESIS           2000

/* Temperature in Milli Celsius reported during stage 0 if no ADC is present */
#define DEFAULT_TEMP                    37000

struct qpnp_tm_chip {
        struct regmap                   *map;
        struct device                   *dev;
        struct thermal_zone_device      *tz_dev;
        unsigned int                    subtype;
        long                            temp;
        unsigned int                    thresh;
        unsigned int                    stage;
        unsigned int                    prev_stage;
        unsigned int                    base;
        /* protects .thresh, .stage and chip registers */
        struct mutex                    lock;
        bool                            initialized;

        struct iio_channel              *adc;
        const long                      (*temp_map)[THRESH_COUNT][STAGE_COUNT];
};

/* This array maps from GEN2 alarm state to GEN1 alarm stage */
static const unsigned int alarm_state_map[8] = {0, 1, 1, 2, 2, 3, 3, 3};

static int qpnp_tm_read(struct qpnp_tm_chip *chip, u16 addr, u8 *data)
{
        unsigned int val;
        int ret;

        ret = regmap_read(chip->map, chip->base + addr, &val);
        if (ret < 0)
                return ret;

        *data = val;
        return 0;
}

static int qpnp_tm_write(struct qpnp_tm_chip *chip, u16 addr, u8 data)
{
        return regmap_write(chip->map, chip->base + addr, data);
}

/**
 * qpnp_tm_decode_temp() - return temperature in mC corresponding to the
 *              specified over-temperature stage
 * @chip:               Pointer to the qpnp_tm chip
 * @stage:              Over-temperature stage
 *
 * Return: temperature in mC
 */
static long qpnp_tm_decode_temp(struct qpnp_tm_chip *chip, unsigned int stage)
{
        if (!chip->temp_map || chip->thresh >= THRESH_COUNT || stage == 0 ||
            stage > STAGE_COUNT)
                return 0;

        return (*chip->temp_map)[chip->thresh][stage - 1];
}

/**
 * qpnp_tm_get_temp_stage() - return over-temperature stage
 * @chip:               Pointer to the qpnp_tm chip
 *
 * Return: stage (GEN1) or state (GEN2) on success, or errno on failure.
 */
static int qpnp_tm_get_temp_stage(struct qpnp_tm_chip *chip)
{
        int ret;
        u8 reg = 0;

        ret = qpnp_tm_read(chip, QPNP_TM_REG_STATUS, &reg);
        if (ret < 0)
                return ret;

        if (chip->subtype == QPNP_TM_SUBTYPE_GEN1)
                ret = reg & STATUS_GEN1_STAGE_MASK;
        else
                ret = (reg & STATUS_GEN2_STATE_MASK) >> STATUS_GEN2_STATE_SHIFT;

        return ret;
}

/*
 * This function updates the internal temp value based on the
 * current thermal stage and threshold as well as the previous stage
 */
static int qpnp_tm_update_temp_no_adc(struct qpnp_tm_chip *chip)
{
        unsigned int stage, stage_new, stage_old;
        int ret;

        WARN_ON(!mutex_is_locked(&chip->lock));

        ret = qpnp_tm_get_temp_stage(chip);
        if (ret < 0)
                return ret;
        stage = ret;

        if (chip->subtype == QPNP_TM_SUBTYPE_GEN1) {
                stage_new = stage;
                stage_old = chip->stage;
        } else {
                stage_new = alarm_state_map[stage];
                stage_old = alarm_state_map[chip->stage];
        }

        if (stage_new > stage_old) {
                /* increasing stage, use lower bound */
                chip->temp = qpnp_tm_decode_temp(chip, stage_new)
                                + TEMP_STAGE_HYSTERESIS;
        } else if (stage_new < stage_old) {
                /* decreasing stage, use upper bound */
                chip->temp = qpnp_tm_decode_temp(chip, stage_new + 1)
                                - TEMP_STAGE_HYSTERESIS;
        }

        chip->stage = stage;

        return 0;
}

static int qpnp_tm_get_temp(void *data, int *temp)
{
        struct qpnp_tm_chip *chip = data;
        int ret, mili_celsius;

        if (!temp)
                return -EINVAL;

        if (!chip->initialized) {
                *temp = DEFAULT_TEMP;
                return 0;
        }

        if (!chip->adc) {
                mutex_lock(&chip->lock);
                ret = qpnp_tm_update_temp_no_adc(chip);
                mutex_unlock(&chip->lock);
                if (ret < 0)
                        return ret;
        } else {
                ret = iio_read_channel_processed(chip->adc, &mili_celsius);
                if (ret < 0)
                        return ret;

                chip->temp = mili_celsius;
        }

        *temp = chip->temp;

        return 0;
}

static int qpnp_tm_update_critical_trip_temp(struct qpnp_tm_chip *chip,
                                             int temp)
{
        long stage2_threshold_min = (*chip->temp_map)[THRESH_MIN][1];
        long stage2_threshold_max = (*chip->temp_map)[THRESH_MAX][1];
        bool disable_s2_shutdown = false;
        u8 reg;

        WARN_ON(!mutex_is_locked(&chip->lock));

        /*
         * Default: S2 and S3 shutdown enabled, thresholds at
         * lowest threshold set, monitoring at 25Hz
         */
        reg = SHUTDOWN_CTRL1_RATE_25HZ;

        if (temp == THERMAL_TEMP_INVALID ||
            temp < stage2_threshold_min) {
                chip->thresh = THRESH_MIN;
                goto skip;
        }

        if (temp <= stage2_threshold_max) {
                chip->thresh = THRESH_MAX -
                        ((stage2_threshold_max - temp) /
                         TEMP_THRESH_STEP);
                disable_s2_shutdown = true;
        } else {
                chip->thresh = THRESH_MAX;

                if (chip->adc)
                        disable_s2_shutdown = true;
                else
                        dev_warn(chip->dev,
                                 "No ADC is configured and critical temperature is above the maximum stage 2 threshold of 140 C! Configuring stage 2 shutdown at 140 C.\n");
        }

skip:
        reg |= chip->thresh;
        if (disable_s2_shutdown)
                reg |= SHUTDOWN_CTRL1_OVERRIDE_S2;

        return qpnp_tm_write(chip, QPNP_TM_REG_SHUTDOWN_CTRL1, reg);
}

static int qpnp_tm_set_trip_temp(void *data, int trip, int temp)
{
        struct qpnp_tm_chip *chip = data;
        const struct thermal_trip *trip_points;
        int ret;

        trip_points = of_thermal_get_trip_points(chip->tz_dev);
        if (!trip_points)
                return -EINVAL;

        if (trip_points[trip].type != THERMAL_TRIP_CRITICAL)
                return 0;

        mutex_lock(&chip->lock);
        ret = qpnp_tm_update_critical_trip_temp(chip, temp);
        mutex_unlock(&chip->lock);

        return ret;
}

static const struct thermal_zone_of_device_ops qpnp_tm_sensor_ops = {
        .get_temp = qpnp_tm_get_temp,
        .set_trip_temp = qpnp_tm_set_trip_temp,
};

static irqreturn_t qpnp_tm_isr(int irq, void *data)
{
        struct qpnp_tm_chip *chip = data;

        thermal_zone_device_update(chip->tz_dev, THERMAL_EVENT_UNSPECIFIED);

        return IRQ_HANDLED;
}

static int qpnp_tm_get_critical_trip_temp(struct qpnp_tm_chip *chip)
{
        int ntrips;
        const struct thermal_trip *trips;
        int i;

        ntrips = of_thermal_get_ntrips(chip->tz_dev);
        if (ntrips <= 0)
                return THERMAL_TEMP_INVALID;

        trips = of_thermal_get_trip_points(chip->tz_dev);
        if (!trips)
                return THERMAL_TEMP_INVALID;

        for (i = 0; i < ntrips; i++) {
                if (of_thermal_is_trip_valid(chip->tz_dev, i) &&
                    trips[i].type == THERMAL_TRIP_CRITICAL)
                        return trips[i].temperature;
        }

        return THERMAL_TEMP_INVALID;
}

/*
 * This function initializes the internal temp value based on only the
 * current thermal stage and threshold. Setup threshold control and
 * disable shutdown override.
 */
static int qpnp_tm_init(struct qpnp_tm_chip *chip)
{
        unsigned int stage;
        int ret;
        u8 reg = 0;
        int crit_temp;

        mutex_lock(&chip->lock);

        ret = qpnp_tm_read(chip, QPNP_TM_REG_SHUTDOWN_CTRL1, &reg);
        if (ret < 0)
                goto out;

        chip->thresh = reg & SHUTDOWN_CTRL1_THRESHOLD_MASK;
        chip->temp = DEFAULT_TEMP;

        ret = qpnp_tm_get_temp_stage(chip);
        if (ret < 0)
                goto out;
        chip->stage = ret;

        stage = chip->subtype == QPNP_TM_SUBTYPE_GEN1
                ? chip->stage : alarm_state_map[chip->stage];

        if (stage)
                chip->temp = qpnp_tm_decode_temp(chip, stage);

        crit_temp = qpnp_tm_get_critical_trip_temp(chip);
        ret = qpnp_tm_update_critical_trip_temp(chip, crit_temp);
        if (ret < 0)
                goto out;

        /* Enable the thermal alarm PMIC module in always-on mode. */
        reg = ALARM_CTRL_FORCE_ENABLE;
        ret = qpnp_tm_write(chip, QPNP_TM_REG_ALARM_CTRL, reg);

        chip->initialized = true;

out:
        mutex_unlock(&chip->lock);
        return ret;
}

static int qpnp_tm_probe(struct platform_device *pdev)
{
        struct qpnp_tm_chip *chip;
        struct device_node *node;
        u8 type, subtype, dig_major;
        u32 res;
        int ret, irq;

        node = pdev->dev.of_node;

        chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
        if (!chip)
                return -ENOMEM;

        dev_set_drvdata(&pdev->dev, chip);
        chip->dev = &pdev->dev;

        mutex_init(&chip->lock);

        chip->map = dev_get_regmap(pdev->dev.parent, NULL);
        if (!chip->map)
                return -ENXIO;

        ret = of_property_read_u32(node, "reg", &res);
        if (ret < 0)
                return ret;

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return irq;

        /* ADC based measurements are optional */
        chip->adc = devm_iio_channel_get(&pdev->dev, "thermal");
        if (IS_ERR(chip->adc)) {
                ret = PTR_ERR(chip->adc);
                chip->adc = NULL;
                if (ret == -EPROBE_DEFER)
                        return ret;
        }

        chip->base = res;

        ret = qpnp_tm_read(chip, QPNP_TM_REG_TYPE, &type);
        if (ret < 0) {
                dev_err(&pdev->dev, "could not read type\n");
                return ret;
        }

        ret = qpnp_tm_read(chip, QPNP_TM_REG_SUBTYPE, &subtype);
        if (ret < 0) {
                dev_err(&pdev->dev, "could not read subtype\n");
                return ret;
        }

        ret = qpnp_tm_read(chip, QPNP_TM_REG_DIG_MAJOR, &dig_major);
        if (ret < 0) {
                dev_err(&pdev->dev, "could not read dig_major\n");
                return ret;
        }

        if (type != QPNP_TM_TYPE || (subtype != QPNP_TM_SUBTYPE_GEN1
                                     && subtype != QPNP_TM_SUBTYPE_GEN2)) {
                dev_err(&pdev->dev, "invalid type 0x%02x or subtype 0x%02x\n",
                        type, subtype);
                return -ENODEV;
        }

        chip->subtype = subtype;
        if (subtype == QPNP_TM_SUBTYPE_GEN2 && dig_major >= 1)
                chip->temp_map = &temp_map_gen2_v1;
        else
                chip->temp_map = &temp_map_gen1;

        /*
         * Register the sensor before initializing the hardware to be able to
         * read the trip points. get_temp() returns the default temperature
         * before the hardware initialization is completed.
         */
        chip->tz_dev = devm_thermal_zone_of_sensor_register(
                &pdev->dev, 0, chip, &qpnp_tm_sensor_ops);
        if (IS_ERR(chip->tz_dev)) {
                dev_err(&pdev->dev, "failed to register sensor\n");
                return PTR_ERR(chip->tz_dev);
        }

        ret = qpnp_tm_init(chip);
        if (ret < 0) {
                dev_err(&pdev->dev, "init failed\n");
                return ret;
        }

        ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, qpnp_tm_isr,
                                        IRQF_ONESHOT, node->name, chip);
        if (ret < 0)
                return ret;

        thermal_zone_device_update(chip->tz_dev, THERMAL_EVENT_UNSPECIFIED);

        return 0;
}

static const struct of_device_id qpnp_tm_match_table[] = {
        { .compatible = "qcom,spmi-temp-alarm" },
        { }
};
MODULE_DEVICE_TABLE(of, qpnp_tm_match_table);

static struct platform_driver qpnp_tm_driver = {
        .driver = {
                .name = "spmi-temp-alarm",
                .of_match_table = qpnp_tm_match_table,
        },
        .probe  = qpnp_tm_probe,
};
module_platform_driver(qpnp_tm_driver);

MODULE_ALIAS("platform:spmi-temp-alarm");
MODULE_DESCRIPTION("QPNP PMIC Temperature Alarm driver");
MODULE_LICENSE("GPL v2");