// SPDX-License-Identifier: GPL-2.0+
/*
 * R-Car Display Unit Encoder
 *
 * Copyright (C) 2013-2014 Renesas Electronics Corporation
 *
 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
 */

#include <linux/export.h>
#include <linux/of.h>

#include <drm/drm_bridge.h>
#include <drm/drm_bridge_connector.h>
#include <drm/drm_panel.h>

#include "rcar_du_drv.h"
#include "rcar_du_encoder.h"
#include "rcar_lvds.h"

/* -----------------------------------------------------------------------------
 * Encoder
 */

static unsigned int rcar_du_encoder_count_ports(struct device_node *node)
{
        struct device_node *ports;
        struct device_node *port;
        unsigned int num_ports = 0;

        ports = of_get_child_by_name(node, "ports");
        if (!ports)
                ports = of_node_get(node);

        for_each_child_of_node(ports, port) {
                if (of_node_name_eq(port, "port"))
                        num_ports++;
        }

        of_node_put(ports);

        return num_ports;
}

static const struct drm_encoder_funcs rcar_du_encoder_funcs = {
};

int rcar_du_encoder_init(struct rcar_du_device *rcdu,
                         enum rcar_du_output output,
                         struct device_node *enc_node)
{
        struct rcar_du_encoder *renc;
        struct drm_connector *connector;
        struct drm_bridge *bridge __free(drm_bridge_put) = NULL;
        int ret;

        /*
         * Locate the DRM bridge from the DT node. For the DPAD outputs, if the
         * DT node has a single port, assume that it describes a panel and
         * create a panel bridge.
         */
        if ((output == RCAR_DU_OUTPUT_DPAD0 ||
             output == RCAR_DU_OUTPUT_DPAD1) &&
            rcar_du_encoder_count_ports(enc_node) == 1) {
                struct drm_panel *panel = of_drm_find_panel(enc_node);

                if (IS_ERR(panel))
                        return PTR_ERR(panel);

                bridge = devm_drm_panel_bridge_add_typed(rcdu->dev, panel,
                                                         DRM_MODE_CONNECTOR_DPI);
                if (IS_ERR(bridge))
                        return PTR_ERR(no_free_ptr(bridge));

                /*
                 * The reference taken by devm_drm_panel_bridge_add_typed() is
                 * released automatically. Take a second one for the __free()
                 * when this function will return.
                 */
                drm_bridge_get(bridge);
        } else {
                bridge = of_drm_find_and_get_bridge(enc_node);
                if (!bridge)
                        return -EPROBE_DEFER;

                if (output == RCAR_DU_OUTPUT_LVDS0 ||
                    output == RCAR_DU_OUTPUT_LVDS1)
                        rcdu->lvds[output - RCAR_DU_OUTPUT_LVDS0] =
                                drm_bridge_get(bridge);

                if (output == RCAR_DU_OUTPUT_DSI0 ||
                    output == RCAR_DU_OUTPUT_DSI1)
                        rcdu->dsi[output - RCAR_DU_OUTPUT_DSI0] =
                                drm_bridge_get(bridge);
        }

        /*
         * Create and initialize the encoder. On Gen3, skip the LVDS1 output if
         * the LVDS1 encoder is used as a companion for LVDS0 in dual-link
         * mode, or any LVDS output if it isn't connected. The latter may happen
         * on D3 or E3 as the LVDS encoders are needed to provide the pixel
         * clock to the DU, even when the LVDS outputs are not used.
         */
        if (rcdu->info->gen >= 3) {
                if (output == RCAR_DU_OUTPUT_LVDS1 &&
                    rcar_lvds_dual_link(bridge))
                        return -ENOLINK;

                if ((output == RCAR_DU_OUTPUT_LVDS0 ||
                     output == RCAR_DU_OUTPUT_LVDS1) &&
                    !rcar_lvds_is_connected(bridge))
                        return -ENOLINK;
        }

        dev_dbg(rcdu->dev, "initializing encoder %pOF for output %s\n",
                enc_node, rcar_du_output_name(output));

        renc = drmm_encoder_alloc(&rcdu->ddev, struct rcar_du_encoder, base,
                                  &rcar_du_encoder_funcs, DRM_MODE_ENCODER_NONE,
                                  NULL);
        if (IS_ERR(renc))
                return PTR_ERR(renc);

        renc->output = output;

        /* Attach the bridge to the encoder. */
        ret = drm_bridge_attach(&renc->base, bridge, NULL,
                                DRM_BRIDGE_ATTACH_NO_CONNECTOR);
        if (ret) {
                dev_err(rcdu->dev,
                        "failed to attach bridge %pOF for output %s (%d)\n",
                        bridge->of_node, rcar_du_output_name(output), ret);
                return ret;
        }

        /* Create the connector for the chain of bridges. */
        connector = drm_bridge_connector_init(&rcdu->ddev, &renc->base);
        if (IS_ERR(connector)) {
                dev_err(rcdu->dev,
                        "failed to created connector for output %s (%ld)\n",
                        rcar_du_output_name(output), PTR_ERR(connector));
                return PTR_ERR(connector);
        }

        return 0;
}

void rcar_du_encoder_cleanup(struct rcar_du_device *rcdu)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(rcdu->lvds); i++)
                drm_bridge_put(rcdu->lvds[i]);
        for (i = 0; i < ARRAY_SIZE(rcdu->dsi); i++)
                drm_bridge_put(rcdu->dsi[i]);
}