// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2018 Broadcom
 */

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

/*
 * In stingray thermal IO memory,
 * Total Number of available TMONs MASK is at offset 0
 * temperature registers BASE is at 4 byte offset.
 * Each TMON temperature register size is 4.
 */
#define SR_TMON_TEMP_BASE(id)   ((id) * 0x4)

#define SR_TMON_MAX_LIST        6

struct sr_tmon {
        unsigned int crit_temp;
        unsigned int tmon_id;
        struct sr_thermal *priv;
};

struct sr_thermal {
        void __iomem *regs;
        unsigned int max_crit_temp;
        struct sr_tmon tmon[SR_TMON_MAX_LIST];
};

static int sr_get_temp(struct thermal_zone_device *tz, int *temp)
{
        struct sr_tmon *tmon = thermal_zone_device_priv(tz);
        struct sr_thermal *sr_thermal = tmon->priv;

        *temp = readl(sr_thermal->regs + SR_TMON_TEMP_BASE(tmon->tmon_id));

        return 0;
}

static const struct thermal_zone_device_ops sr_tz_ops = {
        .get_temp = sr_get_temp,
};

static int sr_thermal_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct thermal_zone_device *tz;
        struct sr_thermal *sr_thermal;
        struct sr_tmon *tmon;
        struct resource *res;
        u32 sr_tmon_list = 0;
        unsigned int i;
        int ret;

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

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res)
                return -ENOENT;

        sr_thermal->regs = (void __iomem *)devm_memremap(&pdev->dev, res->start,
                                                         resource_size(res),
                                                         MEMREMAP_WB);
        if (IS_ERR(sr_thermal->regs)) {
                dev_err(dev, "failed to get io address\n");
                return PTR_ERR(sr_thermal->regs);
        }

        ret = device_property_read_u32(dev, "brcm,tmon-mask", &sr_tmon_list);
        if (ret)
                return ret;

        tmon = sr_thermal->tmon;
        for (i = 0; i < SR_TMON_MAX_LIST; i++, tmon++) {
                if (!(sr_tmon_list & BIT(i)))
                        continue;

                /* Flush temperature registers */
                writel(0, sr_thermal->regs + SR_TMON_TEMP_BASE(i));
                tmon->tmon_id = i;
                tmon->priv = sr_thermal;
                tz = devm_thermal_of_zone_register(dev, i, tmon,
                                                   &sr_tz_ops);
                if (IS_ERR(tz))
                        return PTR_ERR(tz);

                dev_dbg(dev, "thermal sensor %d registered\n", i);
        }

        return 0;
}

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

static struct platform_driver sr_thermal_driver = {
        .probe          = sr_thermal_probe,
        .driver = {
                .name = "sr-thermal",
                .of_match_table = sr_thermal_of_match,
        },
};
module_platform_driver(sr_thermal_driver);

MODULE_AUTHOR("Pramod Kumar <pramod.kumar@broadcom.com>");
MODULE_DESCRIPTION("Stingray thermal driver");
MODULE_LICENSE("GPL v2");