// SPDX-License-Identifier: GPL-2.0-only
/*
 * Exynos DRM Parallel output support.
 *
 * Copyright (c) 2014 Samsung Electronics Co., Ltd
 *
 * Contacts: Andrzej Hajda <a.hajda@samsung.com>
*/

#include <linux/of_graph.h>
#include <linux/regulator/consumer.h>

#include <drm/drm_atomic_helper.h>
#include <drm/drm_panel.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>

#include <video/of_videomode.h>
#include <video/videomode.h>

#include "exynos_drm_crtc.h"

struct exynos_dpi {
        struct drm_encoder encoder;
        struct device *dev;
        struct device_node *panel_node;

        struct drm_panel *panel;
        struct drm_connector connector;

        struct videomode *vm;
};

#define connector_to_dpi(c) container_of(c, struct exynos_dpi, connector)

static inline struct exynos_dpi *encoder_to_dpi(struct drm_encoder *e)
{
        return container_of(e, struct exynos_dpi, encoder);
}

static enum drm_connector_status
exynos_dpi_detect(struct drm_connector *connector, bool force)
{
        struct exynos_dpi *ctx = connector_to_dpi(connector);

        if (ctx->panel && !ctx->panel->connector)
                drm_panel_attach(ctx->panel, &ctx->connector);

        return connector_status_connected;
}

static void exynos_dpi_connector_destroy(struct drm_connector *connector)
{
        drm_connector_unregister(connector);
        drm_connector_cleanup(connector);
}

static const struct drm_connector_funcs exynos_dpi_connector_funcs = {
        .detect = exynos_dpi_detect,
        .fill_modes = drm_helper_probe_single_connector_modes,
        .destroy = exynos_dpi_connector_destroy,
        .reset = drm_atomic_helper_connector_reset,
        .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};

static int exynos_dpi_get_modes(struct drm_connector *connector)
{
        struct exynos_dpi *ctx = connector_to_dpi(connector);

        /* fimd timings gets precedence over panel modes */
        if (ctx->vm) {
                struct drm_display_mode *mode;

                mode = drm_mode_create(connector->dev);
                if (!mode) {
                        DRM_DEV_ERROR(ctx->dev,
                                      "failed to create a new display mode\n");
                        return 0;
                }
                drm_display_mode_from_videomode(ctx->vm, mode);
                mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
                drm_mode_probed_add(connector, mode);
                return 1;
        }

        if (ctx->panel)
                return ctx->panel->funcs->get_modes(ctx->panel);

        return 0;
}

static const struct drm_connector_helper_funcs exynos_dpi_connector_helper_funcs = {
        .get_modes = exynos_dpi_get_modes,
};

static int exynos_dpi_create_connector(struct drm_encoder *encoder)
{
        struct exynos_dpi *ctx = encoder_to_dpi(encoder);
        struct drm_connector *connector = &ctx->connector;
        int ret;

        connector->polled = DRM_CONNECTOR_POLL_HPD;

        ret = drm_connector_init(encoder->dev, connector,
                                 &exynos_dpi_connector_funcs,
                                 DRM_MODE_CONNECTOR_VGA);
        if (ret) {
                DRM_DEV_ERROR(ctx->dev,
                              "failed to initialize connector with drm\n");
                return ret;
        }

        drm_connector_helper_add(connector, &exynos_dpi_connector_helper_funcs);
        drm_connector_attach_encoder(connector, encoder);

        return 0;
}

static void exynos_dpi_mode_set(struct drm_encoder *encoder,
                                struct drm_display_mode *mode,
                                struct drm_display_mode *adjusted_mode)
{
}

static void exynos_dpi_enable(struct drm_encoder *encoder)
{
        struct exynos_dpi *ctx = encoder_to_dpi(encoder);

        if (ctx->panel) {
                drm_panel_prepare(ctx->panel);
                drm_panel_enable(ctx->panel);
        }
}

static void exynos_dpi_disable(struct drm_encoder *encoder)
{
        struct exynos_dpi *ctx = encoder_to_dpi(encoder);

        if (ctx->panel) {
                drm_panel_disable(ctx->panel);
                drm_panel_unprepare(ctx->panel);
        }
}

static const struct drm_encoder_helper_funcs exynos_dpi_encoder_helper_funcs = {
        .mode_set = exynos_dpi_mode_set,
        .enable = exynos_dpi_enable,
        .disable = exynos_dpi_disable,
};

static const struct drm_encoder_funcs exynos_dpi_encoder_funcs = {
        .destroy = drm_encoder_cleanup,
};

enum {
        FIMD_PORT_IN0,
        FIMD_PORT_IN1,
        FIMD_PORT_IN2,
        FIMD_PORT_RGB,
        FIMD_PORT_WRB,
};

static int exynos_dpi_parse_dt(struct exynos_dpi *ctx)
{
        struct device *dev = ctx->dev;
        struct device_node *dn = dev->of_node;
        struct device_node *np;

        ctx->panel_node = of_graph_get_remote_node(dn, FIMD_PORT_RGB, 0);

        np = of_get_child_by_name(dn, "display-timings");
        if (np) {
                struct videomode *vm;
                int ret;

                of_node_put(np);

                vm = devm_kzalloc(dev, sizeof(*ctx->vm), GFP_KERNEL);
                if (!vm)
                        return -ENOMEM;

                ret = of_get_videomode(dn, vm, 0);
                if (ret < 0) {
                        devm_kfree(dev, vm);
                        return ret;
                }

                ctx->vm = vm;

                return 0;
        }

        if (!ctx->panel_node)
                return -EINVAL;

        return 0;
}

int exynos_dpi_bind(struct drm_device *dev, struct drm_encoder *encoder)
{
        int ret;

        drm_encoder_init(dev, encoder, &exynos_dpi_encoder_funcs,
                         DRM_MODE_ENCODER_TMDS, NULL);

        drm_encoder_helper_add(encoder, &exynos_dpi_encoder_helper_funcs);

        ret = exynos_drm_set_possible_crtcs(encoder, EXYNOS_DISPLAY_TYPE_LCD);
        if (ret < 0)
                return ret;

        ret = exynos_dpi_create_connector(encoder);
        if (ret) {
                DRM_DEV_ERROR(encoder_to_dpi(encoder)->dev,
                              "failed to create connector ret = %d\n", ret);
                drm_encoder_cleanup(encoder);
                return ret;
        }

        return 0;
}

struct drm_encoder *exynos_dpi_probe(struct device *dev)
{
        struct exynos_dpi *ctx;
        int ret;

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

        ctx->dev = dev;

        ret = exynos_dpi_parse_dt(ctx);
        if (ret < 0) {
                devm_kfree(dev, ctx);
                return NULL;
        }

        if (ctx->panel_node) {
                ctx->panel = of_drm_find_panel(ctx->panel_node);
                if (IS_ERR(ctx->panel))
                        return ERR_CAST(ctx->panel);
        }

        return &ctx->encoder;
}

int exynos_dpi_remove(struct drm_encoder *encoder)
{
        struct exynos_dpi *ctx = encoder_to_dpi(encoder);

        exynos_dpi_disable(&ctx->encoder);

        if (ctx->panel)
                drm_panel_detach(ctx->panel);

        return 0;
}