// SPDX-License-Identifier: GPL-2.0+
/*
 * HWMON support for Realtek PHY's
 *
 * Author: Heiner Kallweit <hkallweit1@gmail.com>
 */

#include <linux/hwmon.h>
#include <linux/phy.h>

#include "realtek.h"

#define RTL822X_VND2_TSALRM                             0xa662
#define RTL822X_VND2_TSRR                               0xbd84
#define RTL822X_VND2_TSSR                               0xb54c

static int rtl822x_hwmon_get_temp(int raw)
{
        if (raw >= 512)
                raw -= 1024;

        return 1000 * raw / 2;
}

static int rtl822x_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
                              u32 attr, int channel, long *val)
{
        struct phy_device *phydev = dev_get_drvdata(dev);
        int raw;

        switch (attr) {
        case hwmon_temp_input:
                raw = phy_read_mmd(phydev, MDIO_MMD_VEND2, RTL822X_VND2_TSRR) & 0x3ff;
                *val = rtl822x_hwmon_get_temp(raw);
                break;
        case hwmon_temp_max:
                /* Chip reduces speed to 1G if threshold is exceeded */
                raw = phy_read_mmd(phydev, MDIO_MMD_VEND2, RTL822X_VND2_TSSR) >> 6;
                *val = rtl822x_hwmon_get_temp(raw);
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static const struct hwmon_ops rtl822x_hwmon_ops = {
        .visible = 0444,
        .read = rtl822x_hwmon_read,
};

static const struct hwmon_channel_info * const rtl822x_hwmon_info[] = {
        HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_MAX),
        NULL
};

static const struct hwmon_chip_info rtl822x_hwmon_chip_info = {
        .ops = &rtl822x_hwmon_ops,
        .info = rtl822x_hwmon_info,
};

int rtl822x_hwmon_init(struct phy_device *phydev)
{
        struct device *hwdev, *dev = &phydev->mdio.dev;

        /* Ensure over-temp alarm is reset. */
        phy_clear_bits_mmd(phydev, MDIO_MMD_VEND2, RTL822X_VND2_TSALRM, 3);

        hwdev = devm_hwmon_device_register_with_info(dev, NULL, phydev,
                                                     &rtl822x_hwmon_chip_info,
                                                     NULL);
        return PTR_ERR_OR_ZERO(hwdev);
}