// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * rmi-hwmon.c - hwmon sensor support for side band RMI
 *
 * Copyright (C) 2025 Advanced Micro Devices, Inc.
 */
#include <linux/err.h>
#include <linux/hwmon.h>
#include <uapi/misc/amd-apml.h>
#include "rmi-core.h"

/* Do not allow setting negative power limit */
#define SBRMI_PWR_MIN  0

static int sbrmi_read(struct device *dev, enum hwmon_sensor_types type,
                      u32 attr, int channel, long *val)
{
        struct sbrmi_data *data = dev_get_drvdata(dev);
        struct apml_mbox_msg msg = { 0 };
        int ret;

        if (!data)
                return -ENODEV;

        if (type != hwmon_power)
                return -EINVAL;

        switch (attr) {
        case hwmon_power_input:
                msg.cmd = SBRMI_READ_PKG_PWR_CONSUMPTION;
                ret = rmi_mailbox_xfer(data, &msg);
                break;
        case hwmon_power_cap:
                msg.cmd = SBRMI_READ_PKG_PWR_LIMIT;
                ret = rmi_mailbox_xfer(data, &msg);
                break;
        case hwmon_power_cap_max:
                msg.mb_in_out = data->pwr_limit_max;
                ret = 0;
                break;
        default:
                return -EINVAL;
        }
        if (ret < 0)
                return ret;
        /* hwmon power attributes are in microWatt */
        *val = (long)msg.mb_in_out * 1000;
        return ret;
}

static int sbrmi_write(struct device *dev, enum hwmon_sensor_types type,
                       u32 attr, int channel, long val)
{
        struct sbrmi_data *data = dev_get_drvdata(dev);
        struct apml_mbox_msg msg = { 0 };

        if (!data)
                return -ENODEV;

        if (type != hwmon_power && attr != hwmon_power_cap)
                return -EINVAL;
        /*
         * hwmon power attributes are in microWatt
         * mailbox read/write is in mWatt
         */
        val /= 1000;

        val = clamp_val(val, SBRMI_PWR_MIN, data->pwr_limit_max);

        msg.cmd = SBRMI_WRITE_PKG_PWR_LIMIT;
        msg.mb_in_out = val;

        return rmi_mailbox_xfer(data, &msg);
}

static umode_t sbrmi_is_visible(const void *data,
                                enum hwmon_sensor_types type,
                                u32 attr, int channel)
{
        switch (type) {
        case hwmon_power:
                switch (attr) {
                case hwmon_power_input:
                case hwmon_power_cap_max:
                        return 0444;
                case hwmon_power_cap:
                        return 0644;
                }
                break;
        default:
                break;
        }
        return 0;
}

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

static const struct hwmon_ops sbrmi_hwmon_ops = {
        .is_visible = sbrmi_is_visible,
        .read = sbrmi_read,
        .write = sbrmi_write,
};

static const struct hwmon_chip_info sbrmi_chip_info = {
        .ops = &sbrmi_hwmon_ops,
        .info = sbrmi_info,
};

int create_hwmon_sensor_device(struct device *dev, struct sbrmi_data *data)
{
        struct device *hwmon_dev;

        hwmon_dev = devm_hwmon_device_register_with_info(dev, "sbrmi", data,
                                                         &sbrmi_chip_info, NULL);
        return PTR_ERR_OR_ZERO(hwmon_dev);
}