// SPDX-License-Identifier: GPL-2.0+
/*
 * Amlogic Thermal Sensor Driver
 *
 * Copyright (C) 2017 Huan Biao <huan.biao@amlogic.com>
 * Copyright (C) 2019 Guillaume La Roque <glaroque@baylibre.com>
 *
 * Register value to celsius temperature formulas:
 *      Read_Val            m * U
 * U = ---------, uptat = ---------
 *      2^16              1 + n * U
 *
 * Temperature = A * ( uptat + u_efuse / 2^16 )- B
 *
 *  A B m n : calibration parameters
 *  u_efuse : fused calibration value, it's a signed 16 bits value
 */

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/thermal.h>

#include "thermal_hwmon.h"

#define TSENSOR_CFG_REG1                        0x4
        #define TSENSOR_CFG_REG1_RSET_VBG       BIT(12)
        #define TSENSOR_CFG_REG1_RSET_ADC       BIT(11)
        #define TSENSOR_CFG_REG1_VCM_EN         BIT(10)
        #define TSENSOR_CFG_REG1_VBG_EN         BIT(9)
        #define TSENSOR_CFG_REG1_OUT_CTL        BIT(6)
        #define TSENSOR_CFG_REG1_FILTER_EN      BIT(5)
        #define TSENSOR_CFG_REG1_DEM_EN         BIT(3)
        #define TSENSOR_CFG_REG1_CH_SEL         GENMASK(1, 0)
        #define TSENSOR_CFG_REG1_ENABLE         \
                (TSENSOR_CFG_REG1_FILTER_EN |   \
                 TSENSOR_CFG_REG1_VCM_EN |      \
                 TSENSOR_CFG_REG1_VBG_EN |      \
                 TSENSOR_CFG_REG1_DEM_EN |      \
                 TSENSOR_CFG_REG1_CH_SEL)

#define TSENSOR_STAT0                   0x40

#define TSENSOR_STAT9                   0x64

#define TSENSOR_READ_TEMP_MASK          GENMASK(15, 0)
#define TSENSOR_TEMP_MASK               GENMASK(11, 0)

#define TSENSOR_TRIM_SIGN_MASK          BIT(15)
#define TSENSOR_TRIM_TEMP_MASK          GENMASK(14, 0)
#define TSENSOR_TRIM_VERSION_MASK       GENMASK(31, 24)

#define TSENSOR_TRIM_VERSION(_version)  \
        FIELD_GET(TSENSOR_TRIM_VERSION_MASK, _version)

#define TSENSOR_TRIM_CALIB_VALID_MASK   (GENMASK(3, 2) | BIT(7))

#define TSENSOR_CALIB_OFFSET    1
#define TSENSOR_CALIB_SHIFT     4

/**
 * struct amlogic_thermal_soc_calib_data
 * @A: calibration parameters
 * @B: calibration parameters
 * @m: calibration parameters
 * @n: calibration parameters
 *
 * This structure is required for configuration of amlogic thermal driver.
 */
struct amlogic_thermal_soc_calib_data {
        int A;
        int B;
        int m;
        int n;
};

/**
 * struct amlogic_thermal_data
 * @u_efuse_off: register offset to read fused calibration value
 * @calibration_parameters: calibration parameters structure pointer
 * @regmap_config: regmap config for the device
 * This structure is required for configuration of amlogic thermal driver.
 */
struct amlogic_thermal_data {
        int u_efuse_off;
        const struct amlogic_thermal_soc_calib_data *calibration_parameters;
        const struct regmap_config *regmap_config;
};

struct amlogic_thermal {
        struct platform_device *pdev;
        const struct amlogic_thermal_data *data;
        struct regmap *regmap;
        struct regmap *sec_ao_map;
        struct clk *clk;
        struct thermal_zone_device *tzd;
        u32 trim_info;
};

/*
 * Calculate a temperature value from a temperature code.
 * The unit of the temperature is degree milliCelsius.
 */
static int amlogic_thermal_code_to_millicelsius(struct amlogic_thermal *pdata,
                                                int temp_code)
{
        const struct amlogic_thermal_soc_calib_data *param =
                                        pdata->data->calibration_parameters;
        int temp;
        s64 factor, uptat, uefuse;

        uefuse = pdata->trim_info & TSENSOR_TRIM_SIGN_MASK ?
                             ~(pdata->trim_info & TSENSOR_TRIM_TEMP_MASK) + 1 :
                             (pdata->trim_info & TSENSOR_TRIM_TEMP_MASK);

        factor = param->n * temp_code;
        factor = div_s64(factor, 100);

        uptat = temp_code * param->m;
        uptat = div_s64(uptat, 100);
        uptat = uptat * BIT(16);
        uptat = div_s64(uptat, BIT(16) + factor);

        temp = (uptat + uefuse) * param->A;
        temp = div_s64(temp, BIT(16));
        temp = (temp - param->B) * 100;

        return temp;
}

static int amlogic_thermal_initialize(struct amlogic_thermal *pdata)
{
        int ret = 0;
        int ver;

        regmap_read(pdata->sec_ao_map, pdata->data->u_efuse_off,
                    &pdata->trim_info);

        ver = TSENSOR_TRIM_VERSION(pdata->trim_info);

        if ((ver & TSENSOR_TRIM_CALIB_VALID_MASK) == 0) {
                ret = -EINVAL;
                dev_err(&pdata->pdev->dev,
                        "tsensor thermal calibration not supported: 0x%x!\n",
                        ver);
        }

        return ret;
}

static int amlogic_thermal_enable(struct amlogic_thermal *data)
{
        int ret;

        ret = clk_prepare_enable(data->clk);
        if (ret)
                return ret;

        regmap_update_bits(data->regmap, TSENSOR_CFG_REG1,
                           TSENSOR_CFG_REG1_ENABLE, TSENSOR_CFG_REG1_ENABLE);

        return 0;
}

static void amlogic_thermal_disable(struct amlogic_thermal *data)
{
        regmap_update_bits(data->regmap, TSENSOR_CFG_REG1,
                           TSENSOR_CFG_REG1_ENABLE, 0);
        clk_disable_unprepare(data->clk);
}

static int amlogic_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
{
        unsigned int tval;
        struct amlogic_thermal *pdata = thermal_zone_device_priv(tz);

        if (!pdata)
                return -EINVAL;

        regmap_read(pdata->regmap, TSENSOR_STAT0, &tval);
        *temp =
           amlogic_thermal_code_to_millicelsius(pdata,
                                                tval & TSENSOR_READ_TEMP_MASK);

        return 0;
}

static const struct thermal_zone_device_ops amlogic_thermal_ops = {
        .get_temp       = amlogic_thermal_get_temp,
};

static const struct regmap_config amlogic_thermal_regmap_config_g12a = {
        .reg_bits = 8,
        .val_bits = 32,
        .reg_stride = 4,
        .max_register = TSENSOR_STAT9,
};

static const struct amlogic_thermal_soc_calib_data amlogic_thermal_g12a = {
        .A = 9411,
        .B = 3159,
        .m = 424,
        .n = 324,
};

static const struct amlogic_thermal_data amlogic_thermal_g12a_cpu_param = {
        .u_efuse_off = 0x128,
        .calibration_parameters = &amlogic_thermal_g12a,
        .regmap_config = &amlogic_thermal_regmap_config_g12a,
};

static const struct amlogic_thermal_data amlogic_thermal_g12a_ddr_param = {
        .u_efuse_off = 0xf0,
        .calibration_parameters = &amlogic_thermal_g12a,
        .regmap_config = &amlogic_thermal_regmap_config_g12a,
};

static const struct amlogic_thermal_data amlogic_thermal_a1_cpu_param = {
        .u_efuse_off = 0x114,
        .calibration_parameters = &amlogic_thermal_g12a,
        .regmap_config = &amlogic_thermal_regmap_config_g12a,
};

static const struct of_device_id of_amlogic_thermal_match[] = {
        {
                .compatible = "amlogic,g12a-ddr-thermal",
                .data = &amlogic_thermal_g12a_ddr_param,
        },
        {
                .compatible = "amlogic,g12a-cpu-thermal",
                .data = &amlogic_thermal_g12a_cpu_param,
        },
        {
                .compatible = "amlogic,a1-cpu-thermal",
                .data = &amlogic_thermal_a1_cpu_param,
        },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, of_amlogic_thermal_match);

static int amlogic_thermal_probe(struct platform_device *pdev)
{
        struct amlogic_thermal *pdata;
        struct device *dev = &pdev->dev;
        void __iomem *base;
        int ret;

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

        pdata->data = of_device_get_match_data(dev);
        pdata->pdev = pdev;
        platform_set_drvdata(pdev, pdata);

        base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(base))
                return PTR_ERR(base);

        pdata->regmap = devm_regmap_init_mmio(dev, base,
                                              pdata->data->regmap_config);
        if (IS_ERR(pdata->regmap))
                return PTR_ERR(pdata->regmap);

        pdata->clk = devm_clk_get(dev, NULL);
        if (IS_ERR(pdata->clk))
                return dev_err_probe(dev, PTR_ERR(pdata->clk), "failed to get clock\n");

        pdata->sec_ao_map = syscon_regmap_lookup_by_phandle
                (pdev->dev.of_node, "amlogic,ao-secure");
        if (IS_ERR(pdata->sec_ao_map)) {
                dev_err(dev, "syscon regmap lookup failed.\n");
                return PTR_ERR(pdata->sec_ao_map);
        }

        pdata->tzd = devm_thermal_of_zone_register(&pdev->dev,
                                                   0,
                                                   pdata,
                                                   &amlogic_thermal_ops);
        if (IS_ERR(pdata->tzd)) {
                ret = PTR_ERR(pdata->tzd);
                dev_err(dev, "Failed to register tsensor: %d\n", ret);
                return ret;
        }

        devm_thermal_add_hwmon_sysfs(&pdev->dev, pdata->tzd);

        ret = amlogic_thermal_initialize(pdata);
        if (ret)
                return ret;

        ret = amlogic_thermal_enable(pdata);

        return ret;
}

static void amlogic_thermal_remove(struct platform_device *pdev)
{
        struct amlogic_thermal *data = platform_get_drvdata(pdev);

        amlogic_thermal_disable(data);
}

static int amlogic_thermal_suspend(struct device *dev)
{
        struct amlogic_thermal *data = dev_get_drvdata(dev);

        amlogic_thermal_disable(data);

        return 0;
}

static int amlogic_thermal_resume(struct device *dev)
{
        struct amlogic_thermal *data = dev_get_drvdata(dev);

        return amlogic_thermal_enable(data);
}

static DEFINE_SIMPLE_DEV_PM_OPS(amlogic_thermal_pm_ops,
                                amlogic_thermal_suspend,
                                amlogic_thermal_resume);

static struct platform_driver amlogic_thermal_driver = {
        .driver = {
                .name           = "amlogic_thermal",
                .pm             = pm_ptr(&amlogic_thermal_pm_ops),
                .of_match_table = of_amlogic_thermal_match,
        },
        .probe = amlogic_thermal_probe,
        .remove = amlogic_thermal_remove,
};

module_platform_driver(amlogic_thermal_driver);

MODULE_AUTHOR("Guillaume La Roque <glaroque@baylibre.com>");
MODULE_DESCRIPTION("Amlogic thermal driver");
MODULE_LICENSE("GPL v2");