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

#ifndef __DRM_PRIVACY_SCREEN_DRIVER_H__
#define __DRM_PRIVACY_SCREEN_DRIVER_H__

#include <linux/device.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <drm/drm_connector.h>

struct drm_privacy_screen;

/**
 * struct drm_privacy_screen_ops - drm_privacy_screen operations
 *
 * Defines the operations which the privacy-screen class code may call.
 * These functions should be implemented by the privacy-screen driver.
 */
struct drm_privacy_screen_ops {
        /**
         * @set_sw_state: Called to request a change of the privacy-screen
         * state. The privacy-screen class code contains a check to avoid this
         * getting called when the hw_state reports the state is locked.
         * It is the driver's responsibility to update sw_state and hw_state.
         * This is always called with the drm_privacy_screen's lock held.
         */
        int (*set_sw_state)(struct drm_privacy_screen *priv,
                            enum drm_privacy_screen_status sw_state);
        /**
         * @get_hw_state: Called to request that the driver gets the current
         * privacy-screen state from the hardware and then updates sw_state and
         * hw_state accordingly. This will be called by the core just before
         * the privacy-screen is registered in sysfs.
         */
        void (*get_hw_state)(struct drm_privacy_screen *priv);
};

/**
 * struct drm_privacy_screen - central privacy-screen structure
 *
 * Central privacy-screen structure, this contains the struct device used
 * to register the screen in sysfs, the screen's state, ops, etc.
 */
struct drm_privacy_screen {
        /** @dev: device used to register the privacy-screen in sysfs. */
        struct device dev;
        /** @lock: mutex protection all fields in this struct. */
        struct mutex lock;
        /** @list: privacy-screen devices list list-entry. */
        struct list_head list;
        /** @notifier_head: privacy-screen notifier head. */
        struct blocking_notifier_head notifier_head;
        /**
         * @ops: &struct drm_privacy_screen_ops for this privacy-screen.
         * This is NULL if the driver has unregistered the privacy-screen.
         */
        const struct drm_privacy_screen_ops *ops;
        /**
         * @sw_state: The privacy-screen's software state, see
         * :ref:`Standard Connector Properties<standard_connector_properties>`
         * for more info.
         */
        enum drm_privacy_screen_status sw_state;
        /**
         * @hw_state: The privacy-screen's hardware state, see
         * :ref:`Standard Connector Properties<standard_connector_properties>`
         * for more info.
         */
        enum drm_privacy_screen_status hw_state;
        /**
         * @drvdata: Private data owned by the privacy screen provider
         */
        void *drvdata;
};

static inline
void *drm_privacy_screen_get_drvdata(struct drm_privacy_screen *priv)
{
        return priv->drvdata;
}

struct drm_privacy_screen *drm_privacy_screen_register(
        struct device *parent, const struct drm_privacy_screen_ops *ops,
        void *data);
void drm_privacy_screen_unregister(struct drm_privacy_screen *priv);

void drm_privacy_screen_call_notifier_chain(struct drm_privacy_screen *priv);

#endif