// SPDX-License-Identifier: GPL-2.0+
/*
 * Broadcom AVS RO thermal sensor driver
 *
 * based on brcmstb_thermal
 *
 * Copyright (C) 2020 Stefan Wahren
 */

#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.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 AVS_RO_TEMP_STATUS              0x200
#define AVS_RO_TEMP_STATUS_VALID_MSK    (BIT(16) | BIT(10))
#define AVS_RO_TEMP_STATUS_DATA_MSK     GENMASK(9, 0)

struct bcm2711_thermal_priv {
        struct regmap *regmap;
        struct thermal_zone_device *thermal;
};

static int bcm2711_get_temp(struct thermal_zone_device *tz, int *temp)
{
        struct bcm2711_thermal_priv *priv = thermal_zone_device_priv(tz);
        int slope = thermal_zone_get_slope(tz);
        int offset = thermal_zone_get_offset(tz);
        u32 val;
        int ret;

        ret = regmap_read(priv->regmap, AVS_RO_TEMP_STATUS, &val);
        if (ret)
                return ret;

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

        val &= AVS_RO_TEMP_STATUS_DATA_MSK;

        /* Convert a HW code to a temperature reading (millidegree celsius) */
        *temp = slope * val + offset;

        return 0;
}

static const struct thermal_zone_device_ops bcm2711_thermal_of_ops = {
        .get_temp       = bcm2711_get_temp,
};

static const struct of_device_id bcm2711_thermal_id_table[] = {
        { .compatible = "brcm,bcm2711-thermal" },
        {},
};
MODULE_DEVICE_TABLE(of, bcm2711_thermal_id_table);

static int bcm2711_thermal_probe(struct platform_device *pdev)
{
        struct thermal_zone_device *thermal;
        struct bcm2711_thermal_priv *priv;
        struct device *dev = &pdev->dev;
        struct device_node *parent;
        struct regmap *regmap;
        int ret;

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

        /* get regmap from syscon node */
        parent = of_get_parent(dev->of_node); /* parent should be syscon node */
        regmap = syscon_node_to_regmap(parent);
        of_node_put(parent);
        if (IS_ERR(regmap)) {
                ret = PTR_ERR(regmap);
                dev_err(dev, "failed to get regmap: %d\n", ret);
                return ret;
        }
        priv->regmap = regmap;

        thermal = devm_thermal_of_zone_register(dev, 0, priv,
                                                &bcm2711_thermal_of_ops);
        if (IS_ERR(thermal)) {
                ret = PTR_ERR(thermal);
                dev_err(dev, "could not register sensor: %d\n", ret);
                return ret;
        }

        priv->thermal = thermal;

        return thermal_add_hwmon_sysfs(thermal);
}

static struct platform_driver bcm2711_thermal_driver = {
        .probe = bcm2711_thermal_probe,
        .driver = {
                .name = "bcm2711_thermal",
                .of_match_table = bcm2711_thermal_id_table,
        },
};
module_platform_driver(bcm2711_thermal_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Stefan Wahren");
MODULE_DESCRIPTION("Broadcom AVS RO thermal sensor driver");