// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2017 Rafał Miłecki <rafal@milecki.pl>
 */

#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/thermal.h>

#define PVTMON_CONTROL0                                 0x00
#define PVTMON_CONTROL0_SEL_MASK                        0x0000000e
#define PVTMON_CONTROL0_SEL_TEMP_MONITOR                0x00000000
#define PVTMON_CONTROL0_SEL_TEST_MODE                   0x0000000e
#define PVTMON_STATUS                                   0x08

static int ns_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
{
        void __iomem *pvtmon = thermal_zone_device_priv(tz);
        int offset = thermal_zone_get_offset(tz);
        int slope = thermal_zone_get_slope(tz);
        u32 val;

        val = readl(pvtmon + PVTMON_CONTROL0);
        if ((val & PVTMON_CONTROL0_SEL_MASK) != PVTMON_CONTROL0_SEL_TEMP_MONITOR) {
                /* Clear current mode selection */
                val &= ~PVTMON_CONTROL0_SEL_MASK;

                /* Set temp monitor mode (it's the default actually) */
                val |= PVTMON_CONTROL0_SEL_TEMP_MONITOR;

                writel(val, pvtmon + PVTMON_CONTROL0);
        }

        val = readl(pvtmon + PVTMON_STATUS);
        *temp = slope * val + offset;

        return 0;
}

static const struct thermal_zone_device_ops ns_thermal_ops = {
        .get_temp = ns_thermal_get_temp,
};

static int ns_thermal_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct thermal_zone_device *tz;
        void __iomem *pvtmon;

        pvtmon = of_iomap(dev_of_node(dev), 0);
        if (WARN_ON(!pvtmon))
                return -ENOENT;

        tz = devm_thermal_of_zone_register(dev, 0,
                                           pvtmon,
                                           &ns_thermal_ops);
        if (IS_ERR(tz)) {
                iounmap(pvtmon);
                return PTR_ERR(tz);
        }

        platform_set_drvdata(pdev, pvtmon);

        return 0;
}

static void ns_thermal_remove(struct platform_device *pdev)
{
        void __iomem *pvtmon = platform_get_drvdata(pdev);

        iounmap(pvtmon);
}

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

static struct platform_driver ns_thermal_driver = {
        .probe          = ns_thermal_probe,
        .remove         = ns_thermal_remove,
        .driver = {
                .name = "ns-thermal",
                .of_match_table = ns_thermal_of_match,
        },
};
module_platform_driver(ns_thermal_driver);

MODULE_AUTHOR("Rafał Miłecki <rafal@milecki.pl>");
MODULE_DESCRIPTION("Northstar thermal driver");
MODULE_LICENSE("GPL v2");