// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Khadas MCU Controlled FAN driver
 *
 * Copyright (C) 2020 BayLibre SAS
 * Author(s): Neil Armstrong <narmstrong@baylibre.com>
 */

#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/mfd/khadas-mcu.h>
#include <linux/regmap.h>
#include <linux/sysfs.h>
#include <linux/thermal.h>

#define MAX_LEVEL 3

struct khadas_mcu_fan_ctx {
        struct khadas_mcu *mcu;
        unsigned int level;
        struct thermal_cooling_device *cdev;
};

static int khadas_mcu_fan_set_level(struct khadas_mcu_fan_ctx *ctx,
                                    unsigned int level)
{
        int ret;

        ret = regmap_write(ctx->mcu->regmap, KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
                           level);
        if (ret)
                return ret;

        ctx->level = level;

        return 0;
}

static int khadas_mcu_fan_get_max_state(struct thermal_cooling_device *cdev,
                                        unsigned long *state)
{
        *state = MAX_LEVEL;

        return 0;
}

static int khadas_mcu_fan_get_cur_state(struct thermal_cooling_device *cdev,
                                        unsigned long *state)
{
        struct khadas_mcu_fan_ctx *ctx = cdev->devdata;

        *state = ctx->level;

        return 0;
}

static int
khadas_mcu_fan_set_cur_state(struct thermal_cooling_device *cdev,
                             unsigned long state)
{
        struct khadas_mcu_fan_ctx *ctx = cdev->devdata;

        if (state > MAX_LEVEL)
                return -EINVAL;

        if (state == ctx->level)
                return 0;

        return khadas_mcu_fan_set_level(ctx, state);
}

static const struct thermal_cooling_device_ops khadas_mcu_fan_cooling_ops = {
        .get_max_state = khadas_mcu_fan_get_max_state,
        .get_cur_state = khadas_mcu_fan_get_cur_state,
        .set_cur_state = khadas_mcu_fan_set_cur_state,
};

static int khadas_mcu_fan_probe(struct platform_device *pdev)
{
        struct khadas_mcu *mcu = dev_get_drvdata(pdev->dev.parent);
        struct thermal_cooling_device *cdev;
        struct device *dev = &pdev->dev;
        struct khadas_mcu_fan_ctx *ctx;
        int ret;

        ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
        if (!ctx)
                return -ENOMEM;
        ctx->mcu = mcu;
        platform_set_drvdata(pdev, ctx);

        cdev = devm_thermal_of_child_cooling_device_register(dev->parent,
                                                             dev->parent->of_node,
                                                             "khadas-mcu-fan", ctx,
                                                             &khadas_mcu_fan_cooling_ops);
        if (IS_ERR(cdev)) {
                ret = PTR_ERR(cdev);
                dev_err(dev, "Failed to register khadas-mcu-fan as cooling device: %d\n",
                        ret);
                return ret;
        }
        ctx->cdev = cdev;

        return 0;
}

static void khadas_mcu_fan_shutdown(struct platform_device *pdev)
{
        struct khadas_mcu_fan_ctx *ctx = platform_get_drvdata(pdev);

        khadas_mcu_fan_set_level(ctx, 0);
}

#ifdef CONFIG_PM_SLEEP
static int khadas_mcu_fan_suspend(struct device *dev)
{
        struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
        unsigned int level_save = ctx->level;
        int ret;

        ret = khadas_mcu_fan_set_level(ctx, 0);
        if (ret)
                return ret;

        ctx->level = level_save;

        return 0;
}

static int khadas_mcu_fan_resume(struct device *dev)
{
        struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);

        return khadas_mcu_fan_set_level(ctx, ctx->level);
}
#endif

static SIMPLE_DEV_PM_OPS(khadas_mcu_fan_pm, khadas_mcu_fan_suspend,
                         khadas_mcu_fan_resume);

static const struct platform_device_id khadas_mcu_fan_id_table[] = {
        { .name = "khadas-mcu-fan-ctrl", },
        {},
};
MODULE_DEVICE_TABLE(platform, khadas_mcu_fan_id_table);

static struct platform_driver khadas_mcu_fan_driver = {
        .probe          = khadas_mcu_fan_probe,
        .shutdown       = khadas_mcu_fan_shutdown,
        .driver = {
                .name           = "khadas-mcu-fan-ctrl",
                .pm             = &khadas_mcu_fan_pm,
        },
        .id_table       = khadas_mcu_fan_id_table,
};

module_platform_driver(khadas_mcu_fan_driver);

MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
MODULE_DESCRIPTION("Khadas MCU FAN driver");
MODULE_LICENSE("GPL");