// SPDX-License-Identifier: GPL-2.0-only
/*
 * Dove thermal sensor driver
 *
 * Copyright (C) 2013 Andrew Lunn <andrew@lunn.ch>
 */
#include <linux/device.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/thermal.h>

#define DOVE_THERMAL_TEMP_OFFSET        1
#define DOVE_THERMAL_TEMP_MASK          0x1FF

/* Dove Thermal Manager Control and Status Register */
#define PMU_TM_DISABLE_OFFS             0
#define PMU_TM_DISABLE_MASK             (0x1 << PMU_TM_DISABLE_OFFS)

/* Dove Theraml Diode Control 0 Register */
#define PMU_TDC0_SW_RST_MASK            (0x1 << 1)
#define PMU_TDC0_SEL_VCAL_OFFS          5
#define PMU_TDC0_SEL_VCAL_MASK          (0x3 << PMU_TDC0_SEL_VCAL_OFFS)
#define PMU_TDC0_REF_CAL_CNT_OFFS       11
#define PMU_TDC0_REF_CAL_CNT_MASK       (0x1FF << PMU_TDC0_REF_CAL_CNT_OFFS)
#define PMU_TDC0_AVG_NUM_OFFS           25
#define PMU_TDC0_AVG_NUM_MASK           (0x7 << PMU_TDC0_AVG_NUM_OFFS)

/* Dove Thermal Diode Control 1 Register */
#define PMU_TEMP_DIOD_CTRL1_REG         0x04
#define PMU_TDC1_TEMP_VALID_MASK        (0x1 << 10)

/* Dove Thermal Sensor Dev Structure */
struct dove_thermal_priv {
        void __iomem *sensor;
        void __iomem *control;
};

static int dove_init_sensor(const struct dove_thermal_priv *priv)
{
        u32 reg;
        u32 i;

        /* Configure the Diode Control Register #0 */
        reg = readl_relaxed(priv->control);

        /* Use average of 2 */
        reg &= ~PMU_TDC0_AVG_NUM_MASK;
        reg |= (0x1 << PMU_TDC0_AVG_NUM_OFFS);

        /* Reference calibration value */
        reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
        reg |= (0x0F1 << PMU_TDC0_REF_CAL_CNT_OFFS);

        /* Set the high level reference for calibration */
        reg &= ~PMU_TDC0_SEL_VCAL_MASK;
        reg |= (0x2 << PMU_TDC0_SEL_VCAL_OFFS);
        writel(reg, priv->control);

        /* Reset the sensor */
        reg = readl_relaxed(priv->control);
        writel((reg | PMU_TDC0_SW_RST_MASK), priv->control);
        writel(reg, priv->control);

        /* Enable the sensor */
        reg = readl_relaxed(priv->sensor);
        reg &= ~PMU_TM_DISABLE_MASK;
        writel(reg, priv->sensor);

        /* Poll the sensor for the first reading */
        for (i = 0; i < 1000000; i++) {
                reg = readl_relaxed(priv->sensor);
                if (reg & DOVE_THERMAL_TEMP_MASK)
                        break;
        }

        if (i == 1000000)
                return -EIO;

        return 0;
}

static int dove_get_temp(struct thermal_zone_device *thermal,
                          int *temp)
{
        unsigned long reg;
        struct dove_thermal_priv *priv = thermal_zone_device_priv(thermal);

        /* Valid check */
        reg = readl_relaxed(priv->control + PMU_TEMP_DIOD_CTRL1_REG);
        if ((reg & PMU_TDC1_TEMP_VALID_MASK) == 0x0)
                return -EIO;

        /*
         * Calculate temperature. According to Marvell internal
         * documentation the formula for this is:
         * Celsius = (322-reg)/1.3625
         */
        reg = readl_relaxed(priv->sensor);
        reg = (reg >> DOVE_THERMAL_TEMP_OFFSET) & DOVE_THERMAL_TEMP_MASK;
        *temp = ((3220000000UL - (10000000UL * reg)) / 13625);

        return 0;
}

static const struct thermal_zone_device_ops ops = {
        .get_temp = dove_get_temp,
};

static const struct of_device_id dove_thermal_id_table[] = {
        { .compatible = "marvell,dove-thermal" },
        {}
};

static int dove_thermal_probe(struct platform_device *pdev)
{
        struct thermal_zone_device *thermal = NULL;
        struct dove_thermal_priv *priv;
        int ret;

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

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

        priv->control = devm_platform_get_and_ioremap_resource(pdev, 1, NULL);
        if (IS_ERR(priv->control))
                return PTR_ERR(priv->control);

        ret = dove_init_sensor(priv);
        if (ret) {
                dev_err(&pdev->dev, "Failed to initialize sensor\n");
                return ret;
        }

        thermal = thermal_tripless_zone_device_register("dove_thermal", priv,
                                                        &ops, NULL);
        if (IS_ERR(thermal)) {
                dev_err(&pdev->dev,
                        "Failed to register thermal zone device\n");
                return PTR_ERR(thermal);
        }

        ret = thermal_zone_device_enable(thermal);
        if (ret) {
                thermal_zone_device_unregister(thermal);
                return ret;
        }

        platform_set_drvdata(pdev, thermal);

        return 0;
}

static void dove_thermal_exit(struct platform_device *pdev)
{
        struct thermal_zone_device *dove_thermal =
                platform_get_drvdata(pdev);

        thermal_zone_device_unregister(dove_thermal);
}

MODULE_DEVICE_TABLE(of, dove_thermal_id_table);

static struct platform_driver dove_thermal_driver = {
        .probe = dove_thermal_probe,
        .remove = dove_thermal_exit,
        .driver = {
                .name = "dove_thermal",
                .of_match_table = dove_thermal_id_table,
        },
};

module_platform_driver(dove_thermal_driver);

MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
MODULE_DESCRIPTION("Dove thermal driver");
MODULE_LICENSE("GPL");