/*
 * rcar_du_encoder.c  --  R-Car Display Unit Encoder
 *
 * Copyright (C) 2013-2014 Renesas Electronics Corporation
 *
 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/export.h>

#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_panel.h>

#include "rcar_du_drv.h"
#include "rcar_du_encoder.h"
#include "rcar_du_kms.h"
#include "rcar_du_lvdscon.h"
#include "rcar_du_lvdsenc.h"

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

static void rcar_du_encoder_disable(struct drm_encoder *encoder)
{
        struct rcar_du_encoder *renc = to_rcar_encoder(encoder);

        if (renc->connector && renc->connector->panel) {
                drm_panel_disable(renc->connector->panel);
                drm_panel_unprepare(renc->connector->panel);
        }

        if (renc->lvds)
                rcar_du_lvdsenc_enable(renc->lvds, encoder->crtc, false);
}

static void rcar_du_encoder_enable(struct drm_encoder *encoder)
{
        struct rcar_du_encoder *renc = to_rcar_encoder(encoder);

        if (renc->lvds)
                rcar_du_lvdsenc_enable(renc->lvds, encoder->crtc, true);

        if (renc->connector && renc->connector->panel) {
                drm_panel_prepare(renc->connector->panel);
                drm_panel_enable(renc->connector->panel);
        }
}

static int rcar_du_encoder_atomic_check(struct drm_encoder *encoder,
                                        struct drm_crtc_state *crtc_state,
                                        struct drm_connector_state *conn_state)
{
        struct rcar_du_encoder *renc = to_rcar_encoder(encoder);
        struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
        const struct drm_display_mode *mode = &crtc_state->mode;
        struct drm_connector *connector = conn_state->connector;
        struct drm_device *dev = encoder->dev;

        /*
         * Only panel-related encoder types require validation here, everything
         * else is handled by the bridge drivers.
         */
        if (connector->connector_type == DRM_MODE_CONNECTOR_LVDS) {
                const struct drm_display_mode *panel_mode;

                if (list_empty(&connector->modes)) {
                        dev_dbg(dev->dev, "encoder: empty modes list\n");
                        return -EINVAL;
                }

                panel_mode = list_first_entry(&connector->modes,
                                              struct drm_display_mode, head);

                /* We're not allowed to modify the resolution. */
                if (mode->hdisplay != panel_mode->hdisplay ||
                    mode->vdisplay != panel_mode->vdisplay)
                        return -EINVAL;

                /*
                 * The flat panel mode is fixed, just copy it to the adjusted
                 * mode.
                 */
                drm_mode_copy(adjusted_mode, panel_mode);
        }

        if (renc->lvds)
                rcar_du_lvdsenc_atomic_check(renc->lvds, adjusted_mode);

        return 0;
}

static void rcar_du_encoder_mode_set(struct drm_encoder *encoder,
                                     struct drm_crtc_state *crtc_state,
                                     struct drm_connector_state *conn_state)
{
        struct rcar_du_encoder *renc = to_rcar_encoder(encoder);
        struct drm_display_info *info = &conn_state->connector->display_info;
        enum rcar_lvds_mode mode;

        rcar_du_crtc_route_output(crtc_state->crtc, renc->output);

        if (!renc->lvds) {
                /*
                 * The DU driver creates connectors only for the outputs of the
                 * internal LVDS encoders.
                 */
                renc->connector = NULL;
                return;
        }

        renc->connector = to_rcar_connector(conn_state->connector);

        if (!info->num_bus_formats || !info->bus_formats) {
                dev_err(encoder->dev->dev, "no LVDS bus format reported\n");
                return;
        }

        switch (info->bus_formats[0]) {
        case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
        case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
                mode = RCAR_LVDS_MODE_JEIDA;
                break;
        case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
                mode = RCAR_LVDS_MODE_VESA;
                break;
        default:
                dev_err(encoder->dev->dev,
                        "unsupported LVDS bus format 0x%04x\n",
                        info->bus_formats[0]);
                return;
        }

        if (info->bus_flags & DRM_BUS_FLAG_DATA_LSB_TO_MSB)
                mode |= RCAR_LVDS_MODE_MIRROR;

        rcar_du_lvdsenc_set_mode(renc->lvds, mode);
}

static const struct drm_encoder_helper_funcs encoder_helper_funcs = {
        .atomic_mode_set = rcar_du_encoder_mode_set,
        .disable = rcar_du_encoder_disable,
        .enable = rcar_du_encoder_enable,
        .atomic_check = rcar_du_encoder_atomic_check,
};

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

int rcar_du_encoder_init(struct rcar_du_device *rcdu,
                         enum rcar_du_output output,
                         struct device_node *enc_node,
                         struct device_node *con_node)
{
        struct rcar_du_encoder *renc;
        struct drm_encoder *encoder;
        struct drm_bridge *bridge = NULL;
        int ret;

        renc = devm_kzalloc(rcdu->dev, sizeof(*renc), GFP_KERNEL);
        if (renc == NULL)
                return -ENOMEM;

        renc->output = output;
        encoder = rcar_encoder_to_drm_encoder(renc);

        switch (output) {
        case RCAR_DU_OUTPUT_LVDS0:
                renc->lvds = rcdu->lvds[0];
                break;

        case RCAR_DU_OUTPUT_LVDS1:
                renc->lvds = rcdu->lvds[1];
                break;

        default:
                break;
        }

        if (enc_node) {
                dev_dbg(rcdu->dev, "initializing encoder %s for output %u\n",
                        of_node_full_name(enc_node), output);

                /* Locate the DRM bridge from the encoder DT node. */
                bridge = of_drm_find_bridge(enc_node);
                if (!bridge) {
                        ret = -EPROBE_DEFER;
                        goto done;
                }
        } else {
                dev_dbg(rcdu->dev,
                        "initializing internal encoder for output %u\n",
                        output);
        }

        ret = drm_encoder_init(rcdu->ddev, encoder, &encoder_funcs,
                               DRM_MODE_ENCODER_NONE, NULL);
        if (ret < 0)
                goto done;

        drm_encoder_helper_add(encoder, &encoder_helper_funcs);

        if (bridge) {
                /*
                 * Attach the bridge to the encoder. The bridge will create the
                 * connector.
                 */
                ret = drm_bridge_attach(encoder, bridge, NULL);
                if (ret) {
                        drm_encoder_cleanup(encoder);
                        return ret;
                }
        } else {
                /* There's no bridge, create the connector manually. */
                switch (output) {
                case RCAR_DU_OUTPUT_LVDS0:
                case RCAR_DU_OUTPUT_LVDS1:
                        ret = rcar_du_lvds_connector_init(rcdu, renc, con_node);
                        break;

                default:
                        ret = -EINVAL;
                        break;
                }
        }

done:
        if (ret < 0) {
                if (encoder->name)
                        encoder->funcs->destroy(encoder);
                devm_kfree(rcdu->dev, renc);
        }

        return ret;
}