// SPDX-License-Identifier: GPL-2.0+
/*
 * Author: zhanghongchen <zhanghongchen@loongson.cn>
 *         Yinbo Zhu <zhuyinbo@loongson.cn>
 * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
 */

#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/minmax.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/thermal.h>
#include <linux/units.h>

#include "thermal_hwmon.h"

#define LOONGSON2_MAX_SENSOR_SEL_NUM    3

#define LOONGSON2_THSENS_CTRL_HI_REG    0x0
#define LOONGSON2_THSENS_CTRL_LOW_REG   0x8
#define LOONGSON2_THSENS_STATUS_REG     0x10
#define LOONGSON2_THSENS_OUT_REG        0x14

#define LOONGSON2_THSENS_INT_LO         BIT(0)
#define LOONGSON2_THSENS_INT_HIGH       BIT(1)
#define LOONGSON2_THSENS_INT_EN         (LOONGSON2_THSENS_INT_LO | \
                                         LOONGSON2_THSENS_INT_HIGH)
#define LOONGSON2_THSENS_OUT_MASK       0xFF

/*
 * This flag is used to indicate the temperature reading
 * method of the Loongson-2K2000
 */
#define LS2K2000_THSENS_OUT_FLAG        BIT(0)

struct loongson2_thermal_chip_data {
        unsigned int thermal_sensor_sel;
        unsigned int flags;
};

struct loongson2_thermal_data {
        void __iomem *ctrl_reg;
        void __iomem *temp_reg;
        const struct loongson2_thermal_chip_data *chip_data;
};

static void loongson2_set_ctrl_regs(struct loongson2_thermal_data *data,
                                    int ctrl_data, bool low, bool enable)
{
        int reg_ctrl = 0;
        int reg_off  = data->chip_data->thermal_sensor_sel * 2;
        int ctrl_reg = low ? LOONGSON2_THSENS_CTRL_LOW_REG : LOONGSON2_THSENS_CTRL_HI_REG;

        reg_ctrl = ctrl_data + HECTO;
        reg_ctrl |= enable ? 0x100 : 0;
        writew(reg_ctrl, data->ctrl_reg + ctrl_reg + reg_off);
}

static int loongson2_thermal_set(struct loongson2_thermal_data *data,
                                 int low, int high, bool enable)
{
        /* Set low temperature threshold */
        loongson2_set_ctrl_regs(data, clamp(-40, low, high), true, enable);

        /* Set high temperature threshold */
        loongson2_set_ctrl_regs(data, clamp(125, low, high), false, enable);

        return 0;
}

static int loongson2_2k1000_get_temp(struct thermal_zone_device *tz, int *temp)
{
        int val;
        struct loongson2_thermal_data *data = thermal_zone_device_priv(tz);

        val = readl(data->ctrl_reg + LOONGSON2_THSENS_OUT_REG);
        *temp = ((val & LOONGSON2_THSENS_OUT_MASK) - HECTO) * KILO;

        return 0;
}

static int loongson2_2k2000_get_temp(struct thermal_zone_device *tz, int *temp)
{
        int val;
        struct loongson2_thermal_data *data = thermal_zone_device_priv(tz);

        val = readl(data->temp_reg);
        *temp = ((val & 0xffff) * 820 / 0x4000 - 311) * KILO;

        return 0;
}

static irqreturn_t loongson2_thermal_irq_thread(int irq, void *dev)
{
        struct thermal_zone_device *tzd = dev;
        struct loongson2_thermal_data *data = thermal_zone_device_priv(tzd);

        writeb(LOONGSON2_THSENS_INT_EN, data->ctrl_reg + LOONGSON2_THSENS_STATUS_REG);

        thermal_zone_device_update(tzd, THERMAL_EVENT_UNSPECIFIED);

        return IRQ_HANDLED;
}

static int loongson2_thermal_set_trips(struct thermal_zone_device *tz, int low, int high)
{
        struct loongson2_thermal_data *data = thermal_zone_device_priv(tz);

        return loongson2_thermal_set(data, low/MILLI, high/MILLI, true);
}

static const struct thermal_zone_device_ops loongson2_2k1000_of_thermal_ops = {
        .get_temp = loongson2_2k1000_get_temp,
        .set_trips = loongson2_thermal_set_trips,
};

static const struct thermal_zone_device_ops loongson2_2k2000_of_thermal_ops = {
        .get_temp = loongson2_2k2000_get_temp,
        .set_trips = loongson2_thermal_set_trips,
};

static int loongson2_thermal_probe(struct platform_device *pdev)
{
        const struct thermal_zone_device_ops *thermal_ops;
        struct device *dev = &pdev->dev;
        struct loongson2_thermal_data *data;
        struct thermal_zone_device *tzd;
        int ret, irq, i;

        data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        data->chip_data = device_get_match_data(dev);

        data->ctrl_reg = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(data->ctrl_reg))
                return PTR_ERR(data->ctrl_reg);

        /* The temperature output register is separate for Loongson-2K2000 */
        if (data->chip_data->flags & LS2K2000_THSENS_OUT_FLAG) {
                data->temp_reg = devm_platform_ioremap_resource(pdev, 1);
                if (IS_ERR(data->temp_reg))
                        return PTR_ERR(data->temp_reg);

                thermal_ops = &loongson2_2k2000_of_thermal_ops;
        } else {
                thermal_ops = &loongson2_2k1000_of_thermal_ops;
        }

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

        writeb(LOONGSON2_THSENS_INT_EN, data->ctrl_reg + LOONGSON2_THSENS_STATUS_REG);

        loongson2_thermal_set(data, 0, 0, false);

        for (i = 0; i <= LOONGSON2_MAX_SENSOR_SEL_NUM; i++) {
                tzd = devm_thermal_of_zone_register(dev, i, data, thermal_ops);

                if (!IS_ERR(tzd))
                        break;

                if (PTR_ERR(tzd) != -ENODEV)
                        continue;

                return dev_err_probe(dev, PTR_ERR(tzd), "failed to register");
        }

        ret = devm_request_threaded_irq(dev, irq, NULL, loongson2_thermal_irq_thread,
                                        IRQF_ONESHOT, "loongson2_thermal", tzd);
        if (ret < 0)
                return dev_err_probe(dev, ret, "failed to request alarm irq\n");

        devm_thermal_add_hwmon_sysfs(dev, tzd);

        return 0;
}

static const struct loongson2_thermal_chip_data loongson2_thermal_ls2k1000_data = {
        .thermal_sensor_sel = 0,
        .flags = 0,
};

static const struct loongson2_thermal_chip_data loongson2_thermal_ls2k2000_data = {
        .thermal_sensor_sel = 0,
        .flags = LS2K2000_THSENS_OUT_FLAG,
};

static const struct of_device_id of_loongson2_thermal_match[] = {
        {
                .compatible = "loongson,ls2k1000-thermal",
                .data = &loongson2_thermal_ls2k1000_data,
        },
        {
                .compatible = "loongson,ls2k2000-thermal",
                .data = &loongson2_thermal_ls2k2000_data,
        },
        { /* end */ }
};
MODULE_DEVICE_TABLE(of, of_loongson2_thermal_match);

static struct platform_driver loongson2_thermal_driver = {
        .driver = {
                .name           = "loongson2_thermal",
                .of_match_table = of_loongson2_thermal_match,
        },
        .probe  = loongson2_thermal_probe,
};
module_platform_driver(loongson2_thermal_driver);

MODULE_DESCRIPTION("Loongson2 thermal driver");
MODULE_AUTHOR("Loongson Technology Corporation Limited");
MODULE_LICENSE("GPL");