// SPDX-License-Identifier: GPL-2.0
/*
 * AMD HSMP hwmon support
 * Copyright (c) 2025, AMD.
 * All Rights Reserved.
 *
 * This file provides hwmon implementation for HSMP interface.
 */

#include <asm/amd/hsmp.h>

#include <linux/device.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/types.h>
#include <linux/units.h>

#include "hsmp.h"

#define HSMP_HWMON_NAME         "amd_hsmp_hwmon"

static int hsmp_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
                            u32 attr, int channel, long val)
{
        u16 sock_ind = (uintptr_t)dev_get_drvdata(dev);
        struct hsmp_message msg = {};

        if (type != hwmon_power)
                return -EOPNOTSUPP;

        if (attr != hwmon_power_cap)
                return -EOPNOTSUPP;

        msg.num_args = 1;
        msg.args[0] = val / MICROWATT_PER_MILLIWATT;
        msg.msg_id = HSMP_SET_SOCKET_POWER_LIMIT;
        msg.sock_ind = sock_ind;
        return hsmp_send_message(&msg);
}

static int hsmp_hwmon_read(struct device *dev,
                           enum hwmon_sensor_types type,
                           u32 attr, int channel, long *val)
{
        u16 sock_ind = (uintptr_t)dev_get_drvdata(dev);
        struct hsmp_message msg = {};
        int ret;

        if (type != hwmon_power)
                return -EOPNOTSUPP;

        msg.sock_ind = sock_ind;
        msg.response_sz = 1;

        switch (attr) {
        case hwmon_power_input:
                msg.msg_id = HSMP_GET_SOCKET_POWER;
                break;
        case hwmon_power_cap:
                msg.msg_id = HSMP_GET_SOCKET_POWER_LIMIT;
                break;
        case hwmon_power_cap_max:
                msg.msg_id = HSMP_GET_SOCKET_POWER_LIMIT_MAX;
                break;
        default:
                return -EOPNOTSUPP;
        }

        ret = hsmp_send_message(&msg);
        if (!ret)
                *val = msg.args[0] * MICROWATT_PER_MILLIWATT;

        return ret;
}

static umode_t hsmp_hwmon_is_visble(const void *data,
                                    enum hwmon_sensor_types type,
                                    u32 attr, int channel)
{
        if (type != hwmon_power)
                return 0;

        switch (attr) {
        case hwmon_power_input:
                return 0444;
        case hwmon_power_cap:
                return 0644;
        case hwmon_power_cap_max:
                return 0444;
        default:
                return 0;
        }
}

static const struct hwmon_ops hsmp_hwmon_ops = {
        .read = hsmp_hwmon_read,
        .is_visible = hsmp_hwmon_is_visble,
        .write  = hsmp_hwmon_write,
};

static const struct hwmon_channel_info * const hsmp_info[] = {
        HWMON_CHANNEL_INFO(power, HWMON_P_INPUT | HWMON_P_CAP | HWMON_P_CAP_MAX),
        NULL
};

static const struct hwmon_chip_info hsmp_chip_info = {
        .ops = &hsmp_hwmon_ops,
        .info = hsmp_info,
};

int hsmp_create_sensor(struct device *dev, u16 sock_ind)
{
        struct device *hwmon_dev;

        hwmon_dev = devm_hwmon_device_register_with_info(dev, HSMP_HWMON_NAME,
                                                         (void *)(uintptr_t)sock_ind,
                                                         &hsmp_chip_info,
                                                         NULL);
        return PTR_ERR_OR_ZERO(hwmon_dev);
}
EXPORT_SYMBOL_NS(hsmp_create_sensor, "AMD_HSMP");