// SPDX-License-Identifier: GPL-2.0-only
/*
 * SPEAr thermal driver.
 *
 * Copyright (C) 2011-2012 ST Microelectronics
 * Author: Vincenzo Frascino <vincenzo.frascino@st.com>
 */

#include <linux/clk.h>
#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 MD_FACTOR       1000

/* SPEAr Thermal Sensor Dev Structure */
struct spear_thermal_dev {
        /* pointer to base address of the thermal sensor */
        void __iomem *thermal_base;
        /* clk structure */
        struct clk *clk;
        /* pointer to thermal flags */
        unsigned int flags;
};

static inline int thermal_get_temp(struct thermal_zone_device *thermal,
                                int *temp)
{
        struct spear_thermal_dev *stdev = thermal_zone_device_priv(thermal);

        /*
         * Data are ready to be read after 628 usec from POWERDOWN signal
         * (PDN) = 1
         */
        *temp = (readl_relaxed(stdev->thermal_base) & 0x7F) * MD_FACTOR;
        return 0;
}

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

static int __maybe_unused spear_thermal_suspend(struct device *dev)
{
        struct thermal_zone_device *spear_thermal = dev_get_drvdata(dev);
        struct spear_thermal_dev *stdev = thermal_zone_device_priv(spear_thermal);
        unsigned int actual_mask = 0;

        /* Disable SPEAr Thermal Sensor */
        actual_mask = readl_relaxed(stdev->thermal_base);
        writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base);

        clk_disable(stdev->clk);
        dev_info(dev, "Suspended.\n");

        return 0;
}

static int __maybe_unused spear_thermal_resume(struct device *dev)
{
        struct thermal_zone_device *spear_thermal = dev_get_drvdata(dev);
        struct spear_thermal_dev *stdev = thermal_zone_device_priv(spear_thermal);
        unsigned int actual_mask = 0;
        int ret = 0;

        ret = clk_enable(stdev->clk);
        if (ret) {
                dev_err(dev, "Can't enable clock\n");
                return ret;
        }

        /* Enable SPEAr Thermal Sensor */
        actual_mask = readl_relaxed(stdev->thermal_base);
        writel_relaxed(actual_mask | stdev->flags, stdev->thermal_base);

        dev_info(dev, "Resumed.\n");

        return 0;
}

static SIMPLE_DEV_PM_OPS(spear_thermal_pm_ops, spear_thermal_suspend,
                spear_thermal_resume);

static int spear_thermal_probe(struct platform_device *pdev)
{
        struct thermal_zone_device *spear_thermal = NULL;
        struct spear_thermal_dev *stdev;
        struct device_node *np = pdev->dev.of_node;
        int ret = 0, val;

        if (!np || !of_property_read_u32(np, "st,thermal-flags", &val)) {
                dev_err(&pdev->dev, "Failed: DT Pdata not passed\n");
                return -EINVAL;
        }

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

        /* Enable thermal sensor */
        stdev->thermal_base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
        if (IS_ERR(stdev->thermal_base))
                return PTR_ERR(stdev->thermal_base);

        stdev->clk = devm_clk_get(&pdev->dev, NULL);
        if (IS_ERR(stdev->clk)) {
                dev_err(&pdev->dev, "Can't get clock\n");
                return PTR_ERR(stdev->clk);
        }

        ret = clk_enable(stdev->clk);
        if (ret) {
                dev_err(&pdev->dev, "Can't enable clock\n");
                return ret;
        }

        stdev->flags = val;
        writel_relaxed(stdev->flags, stdev->thermal_base);

        spear_thermal = thermal_tripless_zone_device_register("spear_thermal",
                                                              stdev, &ops, NULL);
        if (IS_ERR(spear_thermal)) {
                dev_err(&pdev->dev, "thermal zone device is NULL\n");
                ret = PTR_ERR(spear_thermal);
                goto disable_clk;
        }
        ret = thermal_zone_device_enable(spear_thermal);
        if (ret) {
                dev_err(&pdev->dev, "Cannot enable thermal zone\n");
                goto unregister_tzd;
        }

        platform_set_drvdata(pdev, spear_thermal);

        dev_info(&pdev->dev, "Thermal Sensor Loaded at: 0x%p.\n",
                        stdev->thermal_base);

        return 0;

unregister_tzd:
        thermal_zone_device_unregister(spear_thermal);
disable_clk:
        clk_disable(stdev->clk);

        return ret;
}

static void spear_thermal_exit(struct platform_device *pdev)
{
        unsigned int actual_mask = 0;
        struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);
        struct spear_thermal_dev *stdev = thermal_zone_device_priv(spear_thermal);

        thermal_zone_device_unregister(spear_thermal);

        /* Disable SPEAr Thermal Sensor */
        actual_mask = readl_relaxed(stdev->thermal_base);
        writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base);

        clk_disable(stdev->clk);
}

static const struct of_device_id spear_thermal_id_table[] = {
        { .compatible = "st,thermal-spear1340" },
        {}
};
MODULE_DEVICE_TABLE(of, spear_thermal_id_table);

static struct platform_driver spear_thermal_driver = {
        .probe = spear_thermal_probe,
        .remove = spear_thermal_exit,
        .driver = {
                .name = "spear_thermal",
                .pm = &spear_thermal_pm_ops,
                .of_match_table = spear_thermal_id_table,
        },
};

module_platform_driver(spear_thermal_driver);

MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>");
MODULE_DESCRIPTION("SPEAr thermal driver");
MODULE_LICENSE("GPL");