// SPDX-License-Identifier: GPL-2.0-only
/*
 * Broadcom STB AVS TMON thermal sensor driver
 *
 * Copyright (c) 2015-2017 Broadcom
 */

#define DRV_NAME        "brcmstb_thermal"

#define pr_fmt(fmt)     DRV_NAME ": " fmt

#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/irqreturn.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/thermal.h>

#define AVS_TMON_STATUS                 0x00
 #define AVS_TMON_STATUS_valid_msk      BIT(11)
 #define AVS_TMON_STATUS_data_msk       GENMASK(10, 1)
 #define AVS_TMON_STATUS_data_shift     1

#define AVS_TMON_EN_OVERTEMP_RESET      0x04
 #define AVS_TMON_EN_OVERTEMP_RESET_msk BIT(0)

#define AVS_TMON_RESET_THRESH           0x08
 #define AVS_TMON_RESET_THRESH_msk      GENMASK(10, 1)
 #define AVS_TMON_RESET_THRESH_shift    1

#define AVS_TMON_INT_IDLE_TIME          0x10

#define AVS_TMON_EN_TEMP_INT_SRCS       0x14
 #define AVS_TMON_EN_TEMP_INT_SRCS_high BIT(1)
 #define AVS_TMON_EN_TEMP_INT_SRCS_low  BIT(0)

#define AVS_TMON_INT_THRESH             0x18
 #define AVS_TMON_INT_THRESH_high_msk   GENMASK(26, 17)
 #define AVS_TMON_INT_THRESH_high_shift 17
 #define AVS_TMON_INT_THRESH_low_msk    GENMASK(10, 1)
 #define AVS_TMON_INT_THRESH_low_shift  1

#define AVS_TMON_TEMP_INT_CODE          0x1c
#define AVS_TMON_TP_TEST_ENABLE         0x20

/* Default coefficients */
#define AVS_TMON_TEMP_SLOPE             487
#define AVS_TMON_TEMP_OFFSET            410040

/* HW related temperature constants */
#define AVS_TMON_TEMP_MAX               0x3ff
#define AVS_TMON_TEMP_MIN               -88161
#define AVS_TMON_TEMP_MASK              AVS_TMON_TEMP_MAX

enum avs_tmon_trip_type {
        TMON_TRIP_TYPE_LOW = 0,
        TMON_TRIP_TYPE_HIGH,
        TMON_TRIP_TYPE_RESET,
        TMON_TRIP_TYPE_MAX,
};

struct avs_tmon_trip {
        /* HW bit to enable the trip */
        u32 enable_offs;
        u32 enable_mask;

        /* HW field to read the trip temperature */
        u32 reg_offs;
        u32 reg_msk;
        int reg_shift;
};

static struct avs_tmon_trip avs_tmon_trips[] = {
        /* Trips when temperature is below threshold */
        [TMON_TRIP_TYPE_LOW] = {
                .enable_offs    = AVS_TMON_EN_TEMP_INT_SRCS,
                .enable_mask    = AVS_TMON_EN_TEMP_INT_SRCS_low,
                .reg_offs       = AVS_TMON_INT_THRESH,
                .reg_msk        = AVS_TMON_INT_THRESH_low_msk,
                .reg_shift      = AVS_TMON_INT_THRESH_low_shift,
        },
        /* Trips when temperature is above threshold */
        [TMON_TRIP_TYPE_HIGH] = {
                .enable_offs    = AVS_TMON_EN_TEMP_INT_SRCS,
                .enable_mask    = AVS_TMON_EN_TEMP_INT_SRCS_high,
                .reg_offs       = AVS_TMON_INT_THRESH,
                .reg_msk        = AVS_TMON_INT_THRESH_high_msk,
                .reg_shift      = AVS_TMON_INT_THRESH_high_shift,
        },
        /* Automatically resets chip when above threshold */
        [TMON_TRIP_TYPE_RESET] = {
                .enable_offs    = AVS_TMON_EN_OVERTEMP_RESET,
                .enable_mask    = AVS_TMON_EN_OVERTEMP_RESET_msk,
                .reg_offs       = AVS_TMON_RESET_THRESH,
                .reg_msk        = AVS_TMON_RESET_THRESH_msk,
                .reg_shift      = AVS_TMON_RESET_THRESH_shift,
        },
};

struct brcmstb_thermal_params {
        unsigned int offset;
        unsigned int mult;
        const struct thermal_zone_device_ops *of_ops;
};

struct brcmstb_thermal_priv {
        void __iomem *tmon_base;
        struct device *dev;
        struct thermal_zone_device *thermal;
        /* Process specific thermal parameters used for calculations */
        const struct brcmstb_thermal_params *temp_params;
};

/* Convert a HW code to a temperature reading (millidegree celsius) */
static inline int avs_tmon_code_to_temp(struct brcmstb_thermal_priv *priv,
                                        u32 code)
{
        int offset = priv->temp_params->offset;
        int mult = priv->temp_params->mult;

        return (offset - (int)((code & AVS_TMON_TEMP_MASK) * mult));
}

/*
 * Convert a temperature value (millidegree celsius) to a HW code
 *
 * @temp: temperature to convert
 * @low: if true, round toward the low side
 */
static inline u32 avs_tmon_temp_to_code(struct brcmstb_thermal_priv *priv,
                                        int temp, bool low)
{
        int offset = priv->temp_params->offset;
        int mult = priv->temp_params->mult;

        if (temp < AVS_TMON_TEMP_MIN)
                return AVS_TMON_TEMP_MAX;       /* Maximum code value */

        if (temp >= offset)
                return 0;       /* Minimum code value */

        if (low)
                return (u32)(DIV_ROUND_UP(offset - temp, mult));
        else
                return (u32)((offset - temp) / mult);
}

static int brcmstb_get_temp(struct thermal_zone_device *tz, int *temp)
{
        struct brcmstb_thermal_priv *priv = thermal_zone_device_priv(tz);
        u32 val;
        long t;

        val = __raw_readl(priv->tmon_base + AVS_TMON_STATUS);

        if (!(val & AVS_TMON_STATUS_valid_msk))
                return -EIO;

        val = (val & AVS_TMON_STATUS_data_msk) >> AVS_TMON_STATUS_data_shift;

        t = avs_tmon_code_to_temp(priv, val);
        if (t < 0)
                *temp = 0;
        else
                *temp = t;

        return 0;
}

static void avs_tmon_trip_enable(struct brcmstb_thermal_priv *priv,
                                 enum avs_tmon_trip_type type, int en)
{
        struct avs_tmon_trip *trip = &avs_tmon_trips[type];
        u32 val = __raw_readl(priv->tmon_base + trip->enable_offs);

        dev_dbg(priv->dev, "%sable trip, type %d\n", en ? "en" : "dis", type);

        if (en)
                val |= trip->enable_mask;
        else
                val &= ~trip->enable_mask;

        __raw_writel(val, priv->tmon_base + trip->enable_offs);
}

static int avs_tmon_get_trip_temp(struct brcmstb_thermal_priv *priv,
                                  enum avs_tmon_trip_type type)
{
        struct avs_tmon_trip *trip = &avs_tmon_trips[type];
        u32 val = __raw_readl(priv->tmon_base + trip->reg_offs);

        val &= trip->reg_msk;
        val >>= trip->reg_shift;

        return avs_tmon_code_to_temp(priv, val);
}

static void avs_tmon_set_trip_temp(struct brcmstb_thermal_priv *priv,
                                   enum avs_tmon_trip_type type,
                                   int temp)
{
        struct avs_tmon_trip *trip = &avs_tmon_trips[type];
        u32 val, orig;

        dev_dbg(priv->dev, "set temp %d to %d\n", type, temp);

        /* round toward low temp for the low interrupt */
        val = avs_tmon_temp_to_code(priv, temp,
                                    type == TMON_TRIP_TYPE_LOW);

        val <<= trip->reg_shift;
        val &= trip->reg_msk;

        orig = __raw_readl(priv->tmon_base + trip->reg_offs);
        orig &= ~trip->reg_msk;
        orig |= val;
        __raw_writel(orig, priv->tmon_base + trip->reg_offs);
}

static int avs_tmon_get_intr_temp(struct brcmstb_thermal_priv *priv)
{
        u32 val;

        val = __raw_readl(priv->tmon_base + AVS_TMON_TEMP_INT_CODE);
        return avs_tmon_code_to_temp(priv, val);
}

static irqreturn_t brcmstb_tmon_irq_thread(int irq, void *data)
{
        struct brcmstb_thermal_priv *priv = data;
        int low, high, intr;

        low = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_LOW);
        high = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_HIGH);
        intr = avs_tmon_get_intr_temp(priv);

        dev_dbg(priv->dev, "low/intr/high: %d/%d/%d\n",
                        low, intr, high);

        /* Disable high-temp until next threshold shift */
        if (intr >= high)
                avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
        /* Disable low-temp until next threshold shift */
        if (intr <= low)
                avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);

        /*
         * Notify using the interrupt temperature, in case the temperature
         * changes before it can next be read out
         */
        thermal_zone_device_update(priv->thermal, intr);

        return IRQ_HANDLED;
}

static int brcmstb_set_trips(struct thermal_zone_device *tz, int low, int high)
{
        struct brcmstb_thermal_priv *priv = thermal_zone_device_priv(tz);

        dev_dbg(priv->dev, "set trips %d <--> %d\n", low, high);

        /*
         * Disable low-temp if "low" is too small. As per thermal framework
         * API, we use -INT_MAX rather than INT_MIN.
         */
        if (low <= -INT_MAX) {
                avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
        } else {
                avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_LOW, low);
                avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 1);
        }

        /* Disable high-temp if "high" is too big. */
        if (high == INT_MAX) {
                avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
        } else {
                avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_HIGH, high);
                avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 1);
        }

        return 0;
}

static const struct thermal_zone_device_ops brcmstb_of_ops = {
        .get_temp       = brcmstb_get_temp,
};

static const struct brcmstb_thermal_params brcmstb_8nm_params = {
        .offset = 418670,
        .mult   = 509,
        .of_ops = &brcmstb_of_ops,
};

static const struct brcmstb_thermal_params brcmstb_16nm_params = {
        .offset = 457829,
        .mult   = 557,
        .of_ops = &brcmstb_of_ops,
};

static const struct thermal_zone_device_ops brcmstb_28nm_of_ops = {
        .get_temp       = brcmstb_get_temp,
        .set_trips      = brcmstb_set_trips,
};

static const struct brcmstb_thermal_params brcmstb_28nm_params = {
        .offset = 410040,
        .mult   = 487,
        .of_ops = &brcmstb_28nm_of_ops,
};

static const struct of_device_id brcmstb_thermal_id_table[] = {
        { .compatible = "brcm,avs-tmon-bcm74110", .data = &brcmstb_8nm_params },
        { .compatible = "brcm,avs-tmon-bcm7216", .data = &brcmstb_16nm_params },
        { .compatible = "brcm,avs-tmon", .data = &brcmstb_28nm_params },
        {},
};
MODULE_DEVICE_TABLE(of, brcmstb_thermal_id_table);

static int brcmstb_thermal_probe(struct platform_device *pdev)
{
        const struct thermal_zone_device_ops *of_ops;
        struct thermal_zone_device *thermal;
        struct brcmstb_thermal_priv *priv;
        int irq, ret;

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

        priv->temp_params = of_device_get_match_data(&pdev->dev);
        if (!priv->temp_params)
                return -EINVAL;

        priv->tmon_base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
        if (IS_ERR(priv->tmon_base))
                return PTR_ERR(priv->tmon_base);

        priv->dev = &pdev->dev;
        of_ops = priv->temp_params->of_ops;

        thermal = devm_thermal_of_zone_register(&pdev->dev, 0, priv,
                                                of_ops);
        if (IS_ERR(thermal))
                return dev_err_probe(&pdev->dev, PTR_ERR(thermal),
                                        "could not register sensor\n");

        priv->thermal = thermal;

        irq = platform_get_irq_optional(pdev, 0);
        if (irq >= 0) {
                ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
                                                brcmstb_tmon_irq_thread,
                                                IRQF_ONESHOT,
                                                DRV_NAME, priv);
                if (ret < 0)
                        return dev_err_probe(&pdev->dev, ret,
                                                "could not request IRQ\n");
        }

        dev_info(&pdev->dev, "registered AVS TMON of-sensor driver\n");

        return 0;
}

static struct platform_driver brcmstb_thermal_driver = {
        .probe = brcmstb_thermal_probe,
        .driver = {
                .name = DRV_NAME,
                .of_match_table = brcmstb_thermal_id_table,
        },
};
module_platform_driver(brcmstb_thermal_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Brian Norris");
MODULE_DESCRIPTION("Broadcom STB AVS TMON thermal driver");