/*
 * Copyright (C) 2015 Texas Instruments
 * Author: Jyri Sarha <jsarha@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 */

#include <linux/component.h>
#include <linux/of_graph.h>
#include <drm/drm_of.h>

#include "tilcdc_drv.h"
#include "tilcdc_external.h"

static const struct tilcdc_panel_info panel_info_tda998x = {
                .ac_bias                = 255,
                .ac_bias_intrpt         = 0,
                .dma_burst_sz           = 16,
                .bpp                    = 16,
                .fdd                    = 0x80,
                .tft_alt_mode           = 0,
                .invert_pxl_clk         = 1,
                .sync_edge              = 1,
                .sync_ctrl              = 1,
                .raster_order           = 0,
};

static const struct tilcdc_panel_info panel_info_default = {
                .ac_bias                = 255,
                .ac_bias_intrpt         = 0,
                .dma_burst_sz           = 16,
                .bpp                    = 16,
                .fdd                    = 0x80,
                .tft_alt_mode           = 0,
                .sync_edge              = 0,
                .sync_ctrl              = 1,
                .raster_order           = 0,
};

static int tilcdc_external_mode_valid(struct drm_connector *connector,
                                      struct drm_display_mode *mode)
{
        struct tilcdc_drm_private *priv = connector->dev->dev_private;
        int ret;

        ret = tilcdc_crtc_mode_valid(priv->crtc, mode);
        if (ret != MODE_OK)
                return ret;

        BUG_ON(priv->external_connector != connector);
        BUG_ON(!priv->connector_funcs);

        /* If the connector has its own mode_valid call it. */
        if (!IS_ERR(priv->connector_funcs) &&
            priv->connector_funcs->mode_valid)
                return priv->connector_funcs->mode_valid(connector, mode);

        return MODE_OK;
}

static int tilcdc_add_external_connector(struct drm_device *dev,
                                         struct drm_connector *connector)
{
        struct tilcdc_drm_private *priv = dev->dev_private;
        struct drm_connector_helper_funcs *connector_funcs;

        /* There should never be more than one connector */
        if (WARN_ON(priv->external_connector))
                return -EINVAL;

        priv->external_connector = connector;
        connector_funcs = devm_kzalloc(dev->dev, sizeof(*connector_funcs),
                                       GFP_KERNEL);
        if (!connector_funcs)
                return -ENOMEM;

        /* connector->helper_private contains always struct
         * connector_helper_funcs pointer. For tilcdc crtc to have a
         * say if a specific mode is Ok, we need to install our own
         * helper functions. In our helper functions we copy
         * everything else but use our own mode_valid() (above).
         */
        if (connector->helper_private) {
                priv->connector_funcs = connector->helper_private;
                *connector_funcs = *priv->connector_funcs;
        } else {
                priv->connector_funcs = ERR_PTR(-ENOENT);
        }
        connector_funcs->mode_valid = tilcdc_external_mode_valid;
        drm_connector_helper_add(connector, connector_funcs);

        dev_dbg(dev->dev, "External connector '%s' connected\n",
                connector->name);

        return 0;
}

static
struct drm_connector *tilcdc_encoder_find_connector(struct drm_device *ddev,
                                                    struct drm_encoder *encoder)
{
        struct drm_connector *connector;
        int i;

        list_for_each_entry(connector, &ddev->mode_config.connector_list, head)
                for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++)
                        if (connector->encoder_ids[i] == encoder->base.id)
                                return connector;

        dev_err(ddev->dev, "No connector found for %s encoder (id %d)\n",
                encoder->name, encoder->base.id);

        return NULL;
}

int tilcdc_add_component_encoder(struct drm_device *ddev)
{
        struct tilcdc_drm_private *priv = ddev->dev_private;
        struct drm_connector *connector;
        struct drm_encoder *encoder;

        list_for_each_entry(encoder, &ddev->mode_config.encoder_list, head)
                if (encoder->possible_crtcs & (1 << priv->crtc->index))
                        break;

        if (!encoder) {
                dev_err(ddev->dev, "%s: No suitable encoder found\n", __func__);
                return -ENODEV;
        }

        connector = tilcdc_encoder_find_connector(ddev, encoder);

        if (!connector)
                return -ENODEV;

        /* Only tda998x is supported at the moment. */
        tilcdc_crtc_set_simulate_vesa_sync(priv->crtc, true);
        tilcdc_crtc_set_panel_info(priv->crtc, &panel_info_tda998x);

        return tilcdc_add_external_connector(ddev, connector);
}

void tilcdc_remove_external_device(struct drm_device *dev)
{
        struct tilcdc_drm_private *priv = dev->dev_private;

        /* Restore the original helper functions, if any. */
        if (IS_ERR(priv->connector_funcs))
                drm_connector_helper_add(priv->external_connector, NULL);
        else if (priv->connector_funcs)
                drm_connector_helper_add(priv->external_connector,
                                         priv->connector_funcs);
}

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

static
int tilcdc_attach_bridge(struct drm_device *ddev, struct drm_bridge *bridge)
{
        struct tilcdc_drm_private *priv = ddev->dev_private;
        struct drm_connector *connector;
        int ret;

        priv->external_encoder->possible_crtcs = BIT(0);

        ret = drm_bridge_attach(priv->external_encoder, bridge, NULL);
        if (ret) {
                dev_err(ddev->dev, "drm_bridge_attach() failed %d\n", ret);
                return ret;
        }

        tilcdc_crtc_set_panel_info(priv->crtc, &panel_info_default);

        connector = tilcdc_encoder_find_connector(ddev, priv->external_encoder);
        if (!connector)
                return -ENODEV;

        ret = tilcdc_add_external_connector(ddev, connector);

        return ret;
}

int tilcdc_attach_external_device(struct drm_device *ddev)
{
        struct tilcdc_drm_private *priv = ddev->dev_private;
        struct device_node *remote_node;
        struct drm_bridge *bridge;
        int ret;

        remote_node = of_graph_get_remote_node(ddev->dev->of_node, 0, 0);
        if (!remote_node)
                return 0;

        bridge = of_drm_find_bridge(remote_node);
        of_node_put(remote_node);
        if (!bridge)
                return -EPROBE_DEFER;

        priv->external_encoder = devm_kzalloc(ddev->dev,
                                              sizeof(*priv->external_encoder),
                                              GFP_KERNEL);
        if (!priv->external_encoder)
                return -ENOMEM;

        ret = drm_encoder_init(ddev, priv->external_encoder,
                               &tilcdc_external_encoder_funcs,
                               DRM_MODE_ENCODER_NONE, NULL);
        if (ret) {
                dev_err(ddev->dev, "drm_encoder_init() failed %d\n", ret);
                return ret;
        }

        ret = tilcdc_attach_bridge(ddev, bridge);
        if (ret)
                drm_encoder_cleanup(priv->external_encoder);

        return ret;
}

static int dev_match_of(struct device *dev, void *data)
{
        return dev->of_node == data;
}

int tilcdc_get_external_components(struct device *dev,
                                   struct component_match **match)
{
        struct device_node *node;

        node = of_graph_get_remote_node(dev->of_node, 0, 0);

        if (!of_device_is_compatible(node, "nxp,tda998x")) {
                of_node_put(node);
                return 0;
        }

        if (match)
                drm_of_component_match_add(dev, match, dev_match_of, node);
        of_node_put(node);
        return 1;
}