// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * HWMON driver for ASUS motherboards that provides sensor readouts via WMI
 * interface present in the UEFI of the X370/X470/B450/X399 Ryzen motherboards.
 *
 * Copyright (C) 2018-2019 Ed Brindley <kernel@maidavale.org>
 *
 * WMI interface provides:
 * - CPU Core Voltage,
 * - CPU SOC Voltage,
 * - DRAM Voltage,
 * - VDDP Voltage,
 * - 1.8V PLL Voltage,
 * - +12V Voltage,
 * - +5V Voltage,
 * - 3VSB Voltage,
 * - VBAT Voltage,
 * - AVCC3 Voltage,
 * - SB 1.05V Voltage,
 * - CPU Core Voltage,
 * - CPU SOC Voltage,
 * - DRAM Voltage,
 * - CPU Fan RPM,
 * - Chassis Fan 1 RPM,
 * - Chassis Fan 2 RPM,
 * - Chassis Fan 3 RPM,
 * - HAMP Fan RPM,
 * - Water Pump RPM,
 * - CPU OPT RPM,
 * - Water Flow RPM,
 * - AIO Pump RPM,
 * - CPU Temperature,
 * - CPU Socket Temperature,
 * - Motherboard Temperature,
 * - Chipset Temperature,
 * - Tsensor 1 Temperature,
 * - CPU VRM Temperature,
 * - Water In,
 * - Water Out,
 * - CPU VRM Output Current.
 */

#include <linux/acpi.h>
#include <linux/dmi.h>
#include <linux/hwmon.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/units.h>
#include <linux/wmi.h>

#define ASUSWMI_MONITORING_GUID         "466747A0-70EC-11DE-8A39-0800200C9A66"
#define ASUSWMI_METHODID_GET_VALUE      0x52574543 /* RWEC */
#define ASUSWMI_METHODID_UPDATE_BUFFER  0x51574543 /* QWEC */
#define ASUSWMI_METHODID_GET_INFO       0x50574543 /* PWEC */
#define ASUSWMI_METHODID_GET_NUMBER     0x50574572 /* PWEr */
#define ASUSWMI_METHODID_GET_VERSION    0x50574574 /* PWEt */

#define ASUS_WMI_MAX_STR_SIZE           32

#define DMI_EXACT_MATCH_ASUS_BOARD_NAME(name) {                                 \
        .matches = {                                                            \
                DMI_EXACT_MATCH(DMI_BOARD_VENDOR, "ASUSTeK COMPUTER INC."),     \
                DMI_EXACT_MATCH(DMI_BOARD_NAME, name),                          \
        },                                                                      \
}

static const struct dmi_system_id asus_wmi_dmi_table[] = {
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("PRIME X399-A"),
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("PRIME X470-PRO"),
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG CROSSHAIR VI EXTREME"),
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("CROSSHAIR VI HERO"),
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG CROSSHAIR VI HERO (WI-FI AC)"),
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG CROSSHAIR VII HERO"),
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG CROSSHAIR VII HERO (WI-FI)"),
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX B450-E GAMING"),
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX B450-F GAMING"),
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX B450-F GAMING II"),
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX B450-I GAMING"),
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX X399-E GAMING"),
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX X470-F GAMING"),
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX X470-I GAMING"),
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG ZENITH EXTREME"),
        DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG ZENITH EXTREME ALPHA"),
        {}
};
MODULE_DEVICE_TABLE(dmi, asus_wmi_dmi_table);

enum asus_wmi_sensor_class {
        VOLTAGE         = 0x0,
        TEMPERATURE_C   = 0x1,
        FAN_RPM         = 0x2,
        CURRENT         = 0x3,
        WATER_FLOW      = 0x4,
};

enum asus_wmi_location {
        CPU             = 0x0,
        CPU_SOC         = 0x1,
        DRAM            = 0x2,
        MOTHERBOARD     = 0x3,
        CHIPSET         = 0x4,
        AUX             = 0x5,
        VRM             = 0x6,
        COOLER          = 0x7
};

enum asus_wmi_type {
        SIGNED_INT      = 0x0,
        UNSIGNED_INT    = 0x1,
        SCALED          = 0x3,
};

enum asus_wmi_source {
        SIO             = 0x1,
        EC              = 0x2
};

static enum hwmon_sensor_types asus_data_types[] = {
        [VOLTAGE]       = hwmon_in,
        [TEMPERATURE_C] = hwmon_temp,
        [FAN_RPM]       = hwmon_fan,
        [CURRENT]       = hwmon_curr,
        [WATER_FLOW]    = hwmon_fan,
};

static u32 hwmon_attributes[hwmon_max] = {
        [hwmon_chip]    = HWMON_C_REGISTER_TZ,
        [hwmon_temp]    = HWMON_T_INPUT | HWMON_T_LABEL,
        [hwmon_in]      = HWMON_I_INPUT | HWMON_I_LABEL,
        [hwmon_curr]    = HWMON_C_INPUT | HWMON_C_LABEL,
        [hwmon_fan]     = HWMON_F_INPUT | HWMON_F_LABEL,
};

/**
 * struct asus_wmi_sensor_info - sensor info.
 * @id: sensor id.
 * @data_type: sensor class e.g. voltage, temp etc.
 * @location: sensor location.
 * @name: sensor name.
 * @source: sensor source.
 * @type: sensor type signed, unsigned etc.
 * @cached_value: cached sensor value.
 */
struct asus_wmi_sensor_info {
        u32 id;
        int data_type;
        int location;
        char name[ASUS_WMI_MAX_STR_SIZE];
        int source;
        int type;
        long cached_value;
};

struct asus_wmi_wmi_info {
        unsigned long source_last_updated[3];   /* in jiffies */
        int sensor_count;

        const struct asus_wmi_sensor_info **info[hwmon_max];
        struct asus_wmi_sensor_info **info_by_id;
};

struct asus_wmi_sensors {
        struct asus_wmi_wmi_info wmi;
        /* lock access to internal cache */
        struct mutex lock;
};

/*
 * Universal method for calling WMI method
 */
static int asus_wmi_call_method(u32 method_id, u32 *args, struct acpi_buffer *output)
{
        struct acpi_buffer input = {(acpi_size) sizeof(*args), args };
        acpi_status status;

        status = wmi_evaluate_method(ASUSWMI_MONITORING_GUID, 0,
                                     method_id, &input, output);
        if (ACPI_FAILURE(status))
                return -EIO;

        return 0;
}

/*
 * Gets the version of the ASUS sensors interface implemented
 */
static int asus_wmi_get_version(u32 *version)
{
        struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
        u32 args[] = {0, 0, 0};
        union acpi_object *obj;
        int err;

        err = asus_wmi_call_method(ASUSWMI_METHODID_GET_VERSION, args, &output);
        if (err)
                return err;

        obj = output.pointer;
        if (!obj)
                return -EIO;

        if (obj->type != ACPI_TYPE_INTEGER) {
                err = -EIO;
                goto out_free_obj;
        }

        err = 0;
        *version = obj->integer.value;

out_free_obj:
        ACPI_FREE(obj);
        return err;
}

/*
 * Gets the number of sensor items
 */
static int asus_wmi_get_item_count(u32 *count)
{
        struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
        u32 args[] = {0, 0, 0};
        union acpi_object *obj;
        int err;

        err = asus_wmi_call_method(ASUSWMI_METHODID_GET_NUMBER, args, &output);
        if (err)
                return err;

        obj = output.pointer;
        if (!obj)
                return -EIO;

        if (obj->type != ACPI_TYPE_INTEGER) {
                err = -EIO;
                goto out_free_obj;
        }

        err = 0;
        *count = obj->integer.value;

out_free_obj:
        ACPI_FREE(obj);
        return err;
}

static int asus_wmi_hwmon_add_chan_info(struct hwmon_channel_info *asus_wmi_hwmon_chan,
                                        struct device *dev, int num,
                                        enum hwmon_sensor_types type, u32 config)
{
        u32 *cfg;

        cfg = devm_kcalloc(dev, num + 1, sizeof(*cfg), GFP_KERNEL);
        if (!cfg)
                return -ENOMEM;

        asus_wmi_hwmon_chan->type = type;
        asus_wmi_hwmon_chan->config = cfg;
        memset32(cfg, config, num);

        return 0;
}

/*
 * For a given sensor item returns details e.g. type (voltage/temperature/fan speed etc), bank etc
 */
static int asus_wmi_sensor_info(int index, struct asus_wmi_sensor_info *s)
{
        union acpi_object name_obj, data_type_obj, location_obj, source_obj, type_obj;
        struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
        u32 args[] = {index, 0};
        union acpi_object *obj;
        int err;

        err = asus_wmi_call_method(ASUSWMI_METHODID_GET_INFO, args, &output);
        if (err)
                return err;

        s->id = index;

        obj = output.pointer;
        if (!obj)
                return -EIO;

        if (obj->type != ACPI_TYPE_PACKAGE) {
                err = -EIO;
                goto out_free_obj;
        }

        if (obj->package.count != 5) {
                err = -EIO;
                goto out_free_obj;
        }

        name_obj = obj->package.elements[0];
        if (name_obj.type != ACPI_TYPE_STRING) {
                err = -EIO;
                goto out_free_obj;
        }

        strscpy(s->name, name_obj.string.pointer, sizeof(s->name));

        data_type_obj = obj->package.elements[1];
        if (data_type_obj.type != ACPI_TYPE_INTEGER) {
                err = -EIO;
                goto out_free_obj;
        }

        s->data_type = data_type_obj.integer.value;

        location_obj = obj->package.elements[2];
        if (location_obj.type != ACPI_TYPE_INTEGER) {
                err = -EIO;
                goto out_free_obj;
        }

        s->location = location_obj.integer.value;

        source_obj = obj->package.elements[3];
        if (source_obj.type != ACPI_TYPE_INTEGER) {
                err = -EIO;
                goto out_free_obj;
        }

        s->source = source_obj.integer.value;

        type_obj = obj->package.elements[4];
        if (type_obj.type != ACPI_TYPE_INTEGER) {
                err = -EIO;
                goto out_free_obj;
        }

        err = 0;
        s->type = type_obj.integer.value;

out_free_obj:
        ACPI_FREE(obj);
        return err;
}

static int asus_wmi_update_buffer(int source)
{
        struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
        u32 args[] = {source, 0};

        return asus_wmi_call_method(ASUSWMI_METHODID_UPDATE_BUFFER, args, &output);
}

static int asus_wmi_get_sensor_value(u8 index, long *value)
{
        struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
        u32 args[] = {index, 0};
        union acpi_object *obj;
        int err;

        err = asus_wmi_call_method(ASUSWMI_METHODID_GET_VALUE, args, &output);
        if (err)
                return err;

        obj = output.pointer;
        if (!obj)
                return -EIO;

        if (obj->type != ACPI_TYPE_INTEGER) {
                err = -EIO;
                goto out_free_obj;
        }

        err = 0;
        *value = obj->integer.value;

out_free_obj:
        ACPI_FREE(obj);
        return err;
}

static int asus_wmi_update_values_for_source(u8 source, struct asus_wmi_sensors *sensor_data)
{
        struct asus_wmi_sensor_info *sensor;
        long value = 0;
        int ret;
        int i;

        for (i = 0; i < sensor_data->wmi.sensor_count; i++) {
                sensor = sensor_data->wmi.info_by_id[i];
                if (sensor && sensor->source == source) {
                        ret = asus_wmi_get_sensor_value(sensor->id, &value);
                        if (ret)
                                return ret;

                        sensor->cached_value = value;
                }
        }

        return 0;
}

static int asus_wmi_scale_sensor_value(u32 value, int data_type)
{
        /* FAN_RPM and WATER_FLOW don't need scaling */
        switch (data_type) {
        case VOLTAGE:
                /* value in microVolts */
                return DIV_ROUND_CLOSEST(value,  KILO);
        case TEMPERATURE_C:
                /* value in Celsius */
                return value * MILLIDEGREE_PER_DEGREE;
        case CURRENT:
                /* value in Amperes */
                return value * MILLI;
        }
        return value;
}

static int asus_wmi_get_cached_value_or_update(const struct asus_wmi_sensor_info *sensor,
                                               struct asus_wmi_sensors *sensor_data,
                                               u32 *value)
{
        int ret = 0;

        mutex_lock(&sensor_data->lock);

        if (time_after(jiffies, sensor_data->wmi.source_last_updated[sensor->source] + HZ)) {
                ret = asus_wmi_update_buffer(sensor->source);
                if (ret)
                        goto unlock;

                ret = asus_wmi_update_values_for_source(sensor->source, sensor_data);
                if (ret)
                        goto unlock;

                sensor_data->wmi.source_last_updated[sensor->source] = jiffies;
        }

        *value = sensor->cached_value;

unlock:
        mutex_unlock(&sensor_data->lock);

        return ret;
}

/* Now follow the functions that implement the hwmon interface */
static int asus_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
                               u32 attr, int channel, long *val)
{
        const struct asus_wmi_sensor_info *sensor;
        u32 value = 0;
        int ret;

        struct asus_wmi_sensors *sensor_data = dev_get_drvdata(dev);

        sensor = *(sensor_data->wmi.info[type] + channel);

        ret = asus_wmi_get_cached_value_or_update(sensor, sensor_data, &value);
        if (ret)
                return ret;

        *val = asus_wmi_scale_sensor_value(value, sensor->data_type);

        return ret;
}

static int asus_wmi_hwmon_read_string(struct device *dev,
                                      enum hwmon_sensor_types type, u32 attr,
                                      int channel, const char **str)
{
        struct asus_wmi_sensors *sensor_data = dev_get_drvdata(dev);
        const struct asus_wmi_sensor_info *sensor;

        sensor = *(sensor_data->wmi.info[type] + channel);
        *str = sensor->name;

        return 0;
}

static umode_t asus_wmi_hwmon_is_visible(const void *drvdata,
                                         enum hwmon_sensor_types type, u32 attr,
                                         int channel)
{
        const struct asus_wmi_sensors *sensor_data = drvdata;
        const struct asus_wmi_sensor_info *sensor;

        sensor = *(sensor_data->wmi.info[type] + channel);
        if (sensor)
                return 0444;

        return 0;
}

static const struct hwmon_ops asus_wmi_hwmon_ops = {
        .is_visible = asus_wmi_hwmon_is_visible,
        .read = asus_wmi_hwmon_read,
        .read_string = asus_wmi_hwmon_read_string,
};

static struct hwmon_chip_info asus_wmi_chip_info = {
        .ops = &asus_wmi_hwmon_ops,
        .info = NULL,
};

static int asus_wmi_configure_sensor_setup(struct device *dev,
                                           struct asus_wmi_sensors *sensor_data)
{
        const struct hwmon_channel_info **ptr_asus_wmi_ci;
        struct hwmon_channel_info *asus_wmi_hwmon_chan;
        int nr_count[hwmon_max] = {}, nr_types = 0;
        struct asus_wmi_sensor_info *temp_sensor;
        const struct hwmon_chip_info *chip_info;
        enum hwmon_sensor_types type;
        struct device *hwdev;
        int i, idx;
        int err;

        for (i = 0; i < sensor_data->wmi.sensor_count; i++) {
                struct asus_wmi_sensor_info sensor;

                err = asus_wmi_sensor_info(i, &sensor);
                if (err)
                        return err;

                switch (sensor.data_type) {
                case TEMPERATURE_C:
                case VOLTAGE:
                case CURRENT:
                case FAN_RPM:
                case WATER_FLOW:
                        type = asus_data_types[sensor.data_type];
                        if (!nr_count[type])
                                nr_types++;
                        nr_count[type]++;
                        break;
                }
        }

        if (nr_count[hwmon_temp])
                nr_count[hwmon_chip]++, nr_types++;

        asus_wmi_hwmon_chan = devm_kcalloc(dev, nr_types,
                                           sizeof(*asus_wmi_hwmon_chan),
                                           GFP_KERNEL);
        if (!asus_wmi_hwmon_chan)
                return -ENOMEM;

        ptr_asus_wmi_ci = devm_kcalloc(dev, nr_types + 1,
                                       sizeof(*ptr_asus_wmi_ci), GFP_KERNEL);
        if (!ptr_asus_wmi_ci)
                return -ENOMEM;

        asus_wmi_chip_info.info = ptr_asus_wmi_ci;
        chip_info = &asus_wmi_chip_info;

        sensor_data->wmi.info_by_id = devm_kcalloc(dev, sensor_data->wmi.sensor_count,
                                                   sizeof(*sensor_data->wmi.info_by_id),
                                                   GFP_KERNEL);

        if (!sensor_data->wmi.info_by_id)
                return -ENOMEM;

        for (type = 0; type < hwmon_max; type++) {
                if (!nr_count[type])
                        continue;

                err = asus_wmi_hwmon_add_chan_info(asus_wmi_hwmon_chan, dev,
                                                   nr_count[type], type,
                                                   hwmon_attributes[type]);
                if (err)
                        return err;

                *ptr_asus_wmi_ci++ = asus_wmi_hwmon_chan++;

                sensor_data->wmi.info[type] = devm_kcalloc(dev,
                                                           nr_count[type],
                                                           sizeof(*sensor_data->wmi.info),
                                                           GFP_KERNEL);
                if (!sensor_data->wmi.info[type])
                        return -ENOMEM;
        }

        for (i = sensor_data->wmi.sensor_count - 1; i >= 0; i--) {
                temp_sensor = devm_kzalloc(dev, sizeof(*temp_sensor), GFP_KERNEL);
                if (!temp_sensor)
                        return -ENOMEM;

                err = asus_wmi_sensor_info(i, temp_sensor);
                if (err)
                        continue;

                switch (temp_sensor->data_type) {
                case TEMPERATURE_C:
                case VOLTAGE:
                case CURRENT:
                case FAN_RPM:
                case WATER_FLOW:
                        type = asus_data_types[temp_sensor->data_type];
                        idx = --nr_count[type];
                        *(sensor_data->wmi.info[type] + idx) = temp_sensor;
                        sensor_data->wmi.info_by_id[i] = temp_sensor;
                        break;
                }
        }

        dev_dbg(dev, "board has %d sensors",
                sensor_data->wmi.sensor_count);

        hwdev = devm_hwmon_device_register_with_info(dev, "asus_wmi_sensors",
                                                     sensor_data, chip_info, NULL);

        return PTR_ERR_OR_ZERO(hwdev);
}

static int asus_wmi_probe(struct wmi_device *wdev, const void *context)
{
        struct asus_wmi_sensors *sensor_data;
        struct device *dev = &wdev->dev;
        u32 version = 0;

        if (!dmi_check_system(asus_wmi_dmi_table))
                return -ENODEV;

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

        if (asus_wmi_get_version(&version))
                return -ENODEV;

        if (asus_wmi_get_item_count(&sensor_data->wmi.sensor_count))
                return -ENODEV;

        if (sensor_data->wmi.sensor_count  <= 0 || version < 2) {
                dev_info(dev, "version: %u with %d sensors is unsupported\n",
                         version, sensor_data->wmi.sensor_count);

                return -ENODEV;
        }

        mutex_init(&sensor_data->lock);

        dev_set_drvdata(dev, sensor_data);

        return asus_wmi_configure_sensor_setup(dev, sensor_data);
}

static const struct wmi_device_id asus_wmi_id_table[] = {
        { ASUSWMI_MONITORING_GUID, NULL },
        { }
};

static struct wmi_driver asus_sensors_wmi_driver = {
        .driver = {
                .name = "asus_wmi_sensors",
        },
        .id_table = asus_wmi_id_table,
        .probe = asus_wmi_probe,
};
module_wmi_driver(asus_sensors_wmi_driver);

MODULE_AUTHOR("Ed Brindley <kernel@maidavale.org>");
MODULE_DESCRIPTION("Asus WMI Sensors Driver");
MODULE_LICENSE("GPL");