// SPDX-License-Identifier: GPL-2.0+
/*
 *  Copyright 2013 Matthew Garrett <mjg59@srcf.ucam.org>
 */

#include <linux/acpi.h>
#include <linux/module.h>
#include <linux/slab.h>

MODULE_DESCRIPTION("Intel Rapid Start Technology Driver");
MODULE_LICENSE("GPL");

static ssize_t irst_show_wakeup_events(struct device *dev,
                                       struct device_attribute *attr,
                                       char *buf)
{
        struct acpi_device *acpi;
        unsigned long long value;
        acpi_status status;

        acpi = to_acpi_device(dev);

        status = acpi_evaluate_integer(acpi->handle, "GFFS", NULL, &value);
        if (ACPI_FAILURE(status))
                return -EINVAL;

        return sprintf(buf, "%lld\n", value);
}

static ssize_t irst_store_wakeup_events(struct device *dev,
                                        struct device_attribute *attr,
                                        const char *buf, size_t count)
{
        struct acpi_device *acpi;
        acpi_status status;
        unsigned long value;
        int error;

        acpi = to_acpi_device(dev);

        error = kstrtoul(buf, 0, &value);
        if (error)
                return error;

        status = acpi_execute_simple_method(acpi->handle, "SFFS", value);
        if (ACPI_FAILURE(status))
                return -EINVAL;

        return count;
}

static struct device_attribute irst_wakeup_attr = {
        .attr = { .name = "wakeup_events", .mode = 0600 },
        .show = irst_show_wakeup_events,
        .store = irst_store_wakeup_events
};

static ssize_t irst_show_wakeup_time(struct device *dev,
                                     struct device_attribute *attr, char *buf)
{
        struct acpi_device *acpi;
        unsigned long long value;
        acpi_status status;

        acpi = to_acpi_device(dev);

        status = acpi_evaluate_integer(acpi->handle, "GFTV", NULL, &value);
        if (ACPI_FAILURE(status))
                return -EINVAL;

        return sprintf(buf, "%lld\n", value);
}

static ssize_t irst_store_wakeup_time(struct device *dev,
                                      struct device_attribute *attr,
                                      const char *buf, size_t count)
{
        struct acpi_device *acpi;
        acpi_status status;
        unsigned long value;
        int error;

        acpi = to_acpi_device(dev);

        error = kstrtoul(buf, 0, &value);
        if (error)
                return error;

        status = acpi_execute_simple_method(acpi->handle, "SFTV", value);
        if (ACPI_FAILURE(status))
                return -EINVAL;

        return count;
}

static struct device_attribute irst_timeout_attr = {
        .attr = { .name = "wakeup_time", .mode = 0600 },
        .show = irst_show_wakeup_time,
        .store = irst_store_wakeup_time
};

static int irst_add(struct acpi_device *acpi)
{
        int error;

        error = device_create_file(&acpi->dev, &irst_timeout_attr);
        if (unlikely(error))
                return error;

        error = device_create_file(&acpi->dev, &irst_wakeup_attr);
        if (unlikely(error))
                device_remove_file(&acpi->dev, &irst_timeout_attr);

        return error;
}

static void irst_remove(struct acpi_device *acpi)
{
        device_remove_file(&acpi->dev, &irst_wakeup_attr);
        device_remove_file(&acpi->dev, &irst_timeout_attr);
}

static const struct acpi_device_id irst_ids[] = {
        {"INT3392", 0},
        {"", 0}
};

static struct acpi_driver irst_driver = {
        .name = "intel_rapid_start",
        .class = "intel_rapid_start",
        .ids = irst_ids,
        .ops = {
                .add = irst_add,
                .remove = irst_remove,
        },
};

module_acpi_driver(irst_driver);

MODULE_DEVICE_TABLE(acpi, irst_ids);