/*
 * 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 "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 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, i;

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

        for (i = 0; i < priv->num_connectors &&
                     priv->connectors[i] != connector; i++)
                ;

        BUG_ON(priv->connectors[i] != connector);
        BUG_ON(!priv->connector_funcs[i]);

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

        return MODE_OK;
}

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

        priv->connectors[priv->num_connectors] = connector;
        priv->encoders[priv->num_encoders++] = connector->encoder;

        /* 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);
        *bpp = panel_info_tda998x.bpp;

        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[priv->num_connectors] =
                        connector->helper_private;
                *connector_funcs = *priv->connector_funcs[priv->num_connectors];
        } else {
                priv->connector_funcs[priv->num_connectors] = ERR_PTR(-ENOENT);
        }
        connector_funcs->mode_valid = tilcdc_external_mode_valid;
        drm_connector_helper_add(connector, connector_funcs);
        priv->num_connectors++;

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

        return 0;
}

int tilcdc_add_external_encoders(struct drm_device *dev, int *bpp)
{
        struct tilcdc_drm_private *priv = dev->dev_private;
        struct drm_connector *connector;
        int num_internal_connectors = priv->num_connectors;

        list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
                bool found = false;
                int i, ret;

                for (i = 0; i < num_internal_connectors; i++)
                        if (connector == priv->connectors[i])
                                found = true;
                if (!found) {
                        ret = tilcdc_add_external_encoder(dev, bpp, connector);
                        if (ret)
                                return ret;
                }
        }
        return 0;
}

void tilcdc_remove_external_encoders(struct drm_device *dev)
{
        struct tilcdc_drm_private *priv = dev->dev_private;
        int i;

        /* Restore the original helper functions, if any. */
        for (i = 0; i < priv->num_connectors; i++)
                if (IS_ERR(priv->connector_funcs[i]))
                        drm_connector_helper_add(priv->connectors[i], NULL);
                else if (priv->connector_funcs[i])
                        drm_connector_helper_add(priv->connectors[i],
                                                 priv->connector_funcs[i]);
}

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 *ep = NULL;
        int count = 0;

        while ((ep = of_graph_get_next_endpoint(dev->of_node, ep))) {
                struct device_node *node;

                node = of_graph_get_remote_port_parent(ep);
                if (!node && !of_device_is_available(node)) {
                        of_node_put(node);
                        continue;
                }

                dev_dbg(dev, "Subdevice node '%s' found\n", node->name);
                if (match)
                        component_match_add(dev, match, dev_match_of, node);
                of_node_put(node);
                count++;
        }

        if (count > 1) {
                dev_err(dev, "Only one external encoder is supported\n");
                return -EINVAL;
        }

        return count;
}