// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 * Copyright (C) 2017 Broadcom
 */

#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_connector.h>
#include <drm/drm_encoder.h>
#include <drm/drm_modeset_helper_vtables.h>
#include <drm/drm_of.h>
#include <drm/drm_panel.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>

struct panel_bridge {
        struct drm_bridge bridge;
        struct drm_connector connector;
        struct drm_panel *panel;
        u32 connector_type;
};

static inline struct panel_bridge *
drm_bridge_to_panel_bridge(struct drm_bridge *bridge)
{
        return container_of(bridge, struct panel_bridge, bridge);
}

static inline struct panel_bridge *
drm_connector_to_panel_bridge(struct drm_connector *connector)
{
        return container_of(connector, struct panel_bridge, connector);
}

static int panel_bridge_connector_get_modes(struct drm_connector *connector)
{
        struct panel_bridge *panel_bridge =
                drm_connector_to_panel_bridge(connector);

        return drm_panel_get_modes(panel_bridge->panel, connector);
}

static const struct drm_connector_helper_funcs
panel_bridge_connector_helper_funcs = {
        .get_modes = panel_bridge_connector_get_modes,
};

static const struct drm_connector_funcs panel_bridge_connector_funcs = {
        .reset = drm_atomic_helper_connector_reset,
        .fill_modes = drm_helper_probe_single_connector_modes,
        .destroy = drm_connector_cleanup,
        .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};

static int panel_bridge_attach(struct drm_bridge *bridge,
                               enum drm_bridge_attach_flags flags)
{
        struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
        struct drm_connector *connector = &panel_bridge->connector;
        int ret;

        if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
                return 0;

        if (!bridge->encoder) {
                DRM_ERROR("Missing encoder\n");
                return -ENODEV;
        }

        drm_connector_helper_add(connector,
                                 &panel_bridge_connector_helper_funcs);

        ret = drm_connector_init(bridge->dev, connector,
                                 &panel_bridge_connector_funcs,
                                 panel_bridge->connector_type);
        if (ret) {
                DRM_ERROR("Failed to initialize connector\n");
                return ret;
        }

        drm_connector_attach_encoder(&panel_bridge->connector,
                                          bridge->encoder);

        return 0;
}

static void panel_bridge_detach(struct drm_bridge *bridge)
{
        struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
        struct drm_connector *connector = &panel_bridge->connector;

        /*
         * Cleanup the connector if we know it was initialized.
         *
         * FIXME: This wouldn't be needed if the panel_bridge structure was
         * allocated with drmm_kzalloc(). This might be tricky since the
         * drm_device pointer can only be retrieved when the bridge is attached.
         */
        if (connector->dev)
                drm_connector_cleanup(connector);
}

static void panel_bridge_pre_enable(struct drm_bridge *bridge)
{
        struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);

        drm_panel_prepare(panel_bridge->panel);
}

static void panel_bridge_enable(struct drm_bridge *bridge)
{
        struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);

        drm_panel_enable(panel_bridge->panel);
}

static void panel_bridge_disable(struct drm_bridge *bridge)
{
        struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);

        drm_panel_disable(panel_bridge->panel);
}

static void panel_bridge_post_disable(struct drm_bridge *bridge)
{
        struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);

        drm_panel_unprepare(panel_bridge->panel);
}

static int panel_bridge_get_modes(struct drm_bridge *bridge,
                                  struct drm_connector *connector)
{
        struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);

        return drm_panel_get_modes(panel_bridge->panel, connector);
}

static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {
        .attach = panel_bridge_attach,
        .detach = panel_bridge_detach,
        .pre_enable = panel_bridge_pre_enable,
        .enable = panel_bridge_enable,
        .disable = panel_bridge_disable,
        .post_disable = panel_bridge_post_disable,
        .get_modes = panel_bridge_get_modes,
        .atomic_reset = drm_atomic_helper_bridge_reset,
        .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
        .atomic_get_input_bus_fmts = drm_atomic_helper_bridge_propagate_bus_fmt,
};

/**
 * drm_panel_bridge_add - Creates a &drm_bridge and &drm_connector that
 * just calls the appropriate functions from &drm_panel.
 *
 * @panel: The drm_panel being wrapped.  Must be non-NULL.
 *
 * For drivers converting from directly using drm_panel: The expected
 * usage pattern is that during either encoder module probe or DSI
 * host attach, a drm_panel will be looked up through
 * drm_of_find_panel_or_bridge().  drm_panel_bridge_add() is used to
 * wrap that panel in the new bridge, and the result can then be
 * passed to drm_bridge_attach().  The drm_panel_prepare() and related
 * functions can be dropped from the encoder driver (they're now
 * called by the KMS helpers before calling into the encoder), along
 * with connector creation.  When done with the bridge (after
 * drm_mode_config_cleanup() if the bridge has already been attached), then
 * drm_panel_bridge_remove() to free it.
 *
 * The connector type is set to @panel->connector_type, which must be set to a
 * known type. Calling this function with a panel whose connector type is
 * DRM_MODE_CONNECTOR_Unknown will return ERR_PTR(-EINVAL).
 *
 * See devm_drm_panel_bridge_add() for an automatically managed version of this
 * function.
 */
struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel)
{
        if (WARN_ON(panel->connector_type == DRM_MODE_CONNECTOR_Unknown))
                return ERR_PTR(-EINVAL);

        return drm_panel_bridge_add_typed(panel, panel->connector_type);
}
EXPORT_SYMBOL(drm_panel_bridge_add);

/**
 * drm_panel_bridge_add_typed - Creates a &drm_bridge and &drm_connector with
 * an explicit connector type.
 * @panel: The drm_panel being wrapped.  Must be non-NULL.
 * @connector_type: The connector type (DRM_MODE_CONNECTOR_*)
 *
 * This is just like drm_panel_bridge_add(), but forces the connector type to
 * @connector_type instead of infering it from the panel.
 *
 * This function is deprecated and should not be used in new drivers. Use
 * drm_panel_bridge_add() instead, and fix panel drivers as necessary if they
 * don't report a connector type.
 */
struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
                                              u32 connector_type)
{
        struct panel_bridge *panel_bridge;

        if (!panel)
                return ERR_PTR(-EINVAL);

        panel_bridge = devm_kzalloc(panel->dev, sizeof(*panel_bridge),
                                    GFP_KERNEL);
        if (!panel_bridge)
                return ERR_PTR(-ENOMEM);

        panel_bridge->connector_type = connector_type;
        panel_bridge->panel = panel;

        panel_bridge->bridge.funcs = &panel_bridge_bridge_funcs;
#ifdef CONFIG_OF
        panel_bridge->bridge.of_node = panel->dev->of_node;
#endif
        panel_bridge->bridge.ops = DRM_BRIDGE_OP_MODES;
        panel_bridge->bridge.type = connector_type;

        drm_bridge_add(&panel_bridge->bridge);

        return &panel_bridge->bridge;
}
EXPORT_SYMBOL(drm_panel_bridge_add_typed);

/**
 * drm_panel_bridge_remove - Unregisters and frees a drm_bridge
 * created by drm_panel_bridge_add().
 *
 * @bridge: The drm_bridge being freed.
 */
void drm_panel_bridge_remove(struct drm_bridge *bridge)
{
        struct panel_bridge *panel_bridge;

        if (!bridge)
                return;

        if (bridge->funcs != &panel_bridge_bridge_funcs)
                return;

        panel_bridge = drm_bridge_to_panel_bridge(bridge);

        drm_bridge_remove(bridge);
        devm_kfree(panel_bridge->panel->dev, bridge);
}
EXPORT_SYMBOL(drm_panel_bridge_remove);

static void devm_drm_panel_bridge_release(struct device *dev, void *res)
{
        struct drm_bridge **bridge = res;

        drm_panel_bridge_remove(*bridge);
}

/**
 * devm_drm_panel_bridge_add - Creates a managed &drm_bridge and &drm_connector
 * that just calls the appropriate functions from &drm_panel.
 * @dev: device to tie the bridge lifetime to
 * @panel: The drm_panel being wrapped.  Must be non-NULL.
 *
 * This is the managed version of drm_panel_bridge_add() which automatically
 * calls drm_panel_bridge_remove() when @dev is unbound.
 */
struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
                                             struct drm_panel *panel)
{
        if (WARN_ON(panel->connector_type == DRM_MODE_CONNECTOR_Unknown))
                return ERR_PTR(-EINVAL);

        return devm_drm_panel_bridge_add_typed(dev, panel,
                                               panel->connector_type);
}
EXPORT_SYMBOL(devm_drm_panel_bridge_add);

/**
 * devm_drm_panel_bridge_add_typed - Creates a managed &drm_bridge and
 * &drm_connector with an explicit connector type.
 * @dev: device to tie the bridge lifetime to
 * @panel: The drm_panel being wrapped.  Must be non-NULL.
 * @connector_type: The connector type (DRM_MODE_CONNECTOR_*)
 *
 * This is just like devm_drm_panel_bridge_add(), but forces the connector type
 * to @connector_type instead of infering it from the panel.
 *
 * This function is deprecated and should not be used in new drivers. Use
 * devm_drm_panel_bridge_add() instead, and fix panel drivers as necessary if
 * they don't report a connector type.
 */
struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
                                                   struct drm_panel *panel,
                                                   u32 connector_type)
{
        struct drm_bridge **ptr, *bridge;

        ptr = devres_alloc(devm_drm_panel_bridge_release, sizeof(*ptr),
                           GFP_KERNEL);
        if (!ptr)
                return ERR_PTR(-ENOMEM);

        bridge = drm_panel_bridge_add_typed(panel, connector_type);
        if (!IS_ERR(bridge)) {
                *ptr = bridge;
                devres_add(dev, ptr);
        } else {
                devres_free(ptr);
        }

        return bridge;
}
EXPORT_SYMBOL(devm_drm_panel_bridge_add_typed);

/**
 * drm_panel_bridge_connector - return the connector for the panel bridge
 * @bridge: The drm_bridge.
 *
 * drm_panel_bridge creates the connector.
 * This function gives external access to the connector.
 *
 * Returns: Pointer to drm_connector
 */
struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge)
{
        struct panel_bridge *panel_bridge;

        panel_bridge = drm_bridge_to_panel_bridge(bridge);

        return &panel_bridge->connector;
}
EXPORT_SYMBOL(drm_panel_bridge_connector);

#ifdef CONFIG_OF
/**
 * devm_drm_of_get_bridge - Return next bridge in the chain
 * @dev: device to tie the bridge lifetime to
 * @np: device tree node containing encoder output ports
 * @port: port in the device tree node
 * @endpoint: endpoint in the device tree node
 *
 * Given a DT node's port and endpoint number, finds the connected node
 * and returns the associated bridge if any, or creates and returns a
 * drm panel bridge instance if a panel is connected.
 *
 * Returns a pointer to the bridge if successful, or an error pointer
 * otherwise.
 */
struct drm_bridge *devm_drm_of_get_bridge(struct device *dev,
                                          struct device_node *np,
                                          u32 port, u32 endpoint)
{
        struct drm_bridge *bridge;
        struct drm_panel *panel;
        int ret;

        ret = drm_of_find_panel_or_bridge(np, port, endpoint,
                                          &panel, &bridge);
        if (ret)
                return ERR_PTR(ret);

        if (panel)
                bridge = devm_drm_panel_bridge_add(dev, panel);

        return bridge;
}
EXPORT_SYMBOL(devm_drm_of_get_bridge);
#endif