// SPDX-License-Identifier: MIT
/*
 * Copyright (C) 2020 Red Hat, Inc.
 *
 * Authors:
 * Hans de Goede <hdegoede@redhat.com>
 */

#include <linux/acpi.h>
#include <drm/drm_privacy_screen_machine.h>

#ifdef CONFIG_X86
static struct drm_privacy_screen_lookup arch_lookup;

struct arch_init_data {
        struct drm_privacy_screen_lookup lookup;
        bool (*detect)(void);
};

#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
static acpi_status __init acpi_set_handle(acpi_handle handle, u32 level,
                                          void *context, void **return_value)
{
        *(acpi_handle *)return_value = handle;
        return AE_CTRL_TERMINATE;
}

static bool __init detect_thinkpad_privacy_screen(void)
{
        union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
        struct acpi_object_list args = { .count = 1, .pointer = &obj, };
        acpi_handle ec_handle = NULL;
        unsigned long long output;
        acpi_status status;

        if (acpi_disabled)
                return false;

        /* Get embedded-controller handle */
        status = acpi_get_devices("PNP0C09", acpi_set_handle, NULL, &ec_handle);
        if (ACPI_FAILURE(status) || !ec_handle)
                return false;

        /* And call the privacy-screen get-status method */
        status = acpi_evaluate_integer(ec_handle, "HKEY.GSSS", &args, &output);
        if (ACPI_FAILURE(status))
                return false;

        return (output & 0x10000) ? true : false;
}
#endif

#if IS_ENABLED(CONFIG_CHROMEOS_PRIVACY_SCREEN)
static bool __init detect_chromeos_privacy_screen(void)
{
        return acpi_dev_present("GOOG0010", NULL, -1);
}
#endif

static const struct arch_init_data arch_init_data[] __initconst = {
#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
        {
                .lookup = {
                        .dev_id = NULL,
                        .con_id = NULL,
                        .provider = "privacy_screen-thinkpad_acpi",
                },
                .detect = detect_thinkpad_privacy_screen,
        },
#endif
#if IS_ENABLED(CONFIG_CHROMEOS_PRIVACY_SCREEN)
        {
                .lookup = {
                        .dev_id = NULL,
                        .con_id = NULL,
                        .provider = "privacy_screen-GOOG0010:00",
                },
                .detect = detect_chromeos_privacy_screen,
        },
#endif
};

void __init drm_privacy_screen_lookup_init(void)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(arch_init_data); i++) {
                if (!arch_init_data[i].detect())
                        continue;

                pr_info("Found '%s' privacy-screen provider\n",
                        arch_init_data[i].lookup.provider);

                /* Make a copy because arch_init_data is __initconst */
                arch_lookup = arch_init_data[i].lookup;
                drm_privacy_screen_lookup_add(&arch_lookup);
                break;
        }
}

void drm_privacy_screen_lookup_exit(void)
{
        if (arch_lookup.provider)
                drm_privacy_screen_lookup_remove(&arch_lookup);
}
#endif /* ifdef CONFIG_X86 */